February 13, 2017 | Author: Walid Bensaid | Category: N/A
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Version 3.3.0
Technical Reference Guide for Radio Networks
AT330_TRR_E1
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Release: AT330_TRR_E1 (March 2015) © Copyright 1997-2015 Forsk. All Rights Reserved. Published by: Forsk 7 rue des Briquetiers 31700 Blagnac, France Tel: +33 562 747 210 Fax: +33 562 747 211 The software described in this document is provided under a licence agreement. The software may only be used or copied under the terms and conditions of the licence agreement. No part of the contents of this document may be reproduced or transmitted in any form or by any means without written permission from the publisher. The product or brand names mentioned in this document are trademarks or registered trademarks of their respective registering parties. The publisher has taken care in the preparation of this document, but makes no expressed or implied warranty of any kind and assumes no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of the use of the information contained herein.
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter : Introduction
AT330_TRR_E1
Introduction This Technical Reference Guide is aimed at radio network engineers with an advanced knowledge of Atoll and radio network planning. It provides detailed information about the inner workings and formulas that are implemented by Atoll.
About Atoll Atoll is a 64-bit multi-technology wireless network design and optimisation platform. Atoll is open, scalable, flexible, and supports wireless operators throughout the network life cycle, from initial design to densification and optimisation. Atoll’s integration and automation features help operators smoothly automate planning and optimisation processes through flexible scripting and SOA-based mechanisms. Atoll supports a wide range of implementation scenarios, from standalone to enterprise-wide server-based configurations using distributed and multi-threaded computing. Atoll Microwave is a complete backhaul and microwave link planning solution based on the leading Atoll platform, which includes a high performance GIS and advanced data and user management features. Atoll Microwave can share its site database with Atoll radio planning and optimisation modules, thus allowing easy data consistency management across the operator organisation. If you are interested in learning more about Atoll, please contact your Forsk representative to inquire about our training solutions.
About Forsk Forsk is an independent company providing radio planning and optimisation software solutions to the wireless industry since 1987. In 1997, Forsk released the first version of Atoll, its flagship radio planning software. Since then, Atoll has evolved to become a comprehensive radio planning and optimisation platform and, with more than 5000 installed licenses worldwide, has reached the leading position on the global market. Atoll combines engineering and automation functions that enable operators to smoothly and gradually implement SON processes within their organisation. Today, Forsk is a global supplier with over 300 customers in 100 countries and strategic partnerships with major players in the industry. Forsk distributes and supports Atoll directly from offices and technical support centres in France, USA, and China as well as through a worldwide network of distributors and partners. Since the first release of Atoll, Forsk has been known for its capability to deliver tailored and turn-key radio planning and optimisation environments based on Atoll. To help operators streamline their radio planning and optimisation processes, Forsk provides a complete range of implementation services, including integration with existing IT infrastructure, automation, as well as data migration, installation, and training services.
Getting Help The online help system that is installed with Atoll is designed to give you quick access to the information you need to use the product effectively. It contains the same material as the Atoll 3.3.0 User Manual. You can browse the online help from the Contents view, the Index view, or you can use the built-in Search feature. You can also download manuals from the Forsk web site.
Printing Help Topics You can print individual topics or chapters from the online help. To print help topics or chapters: 1. In Atoll, click Help > Help Topics. 2. In the Contents tab, expand the table of contents. 3. Right-click the section or topic that you want to print and click Print. The Print Topics dialog box appears. 4. In the Print Topics dialog box, select what you want to print: • •
If you want to print a single topic, select Print the selected topic. If you want to print an entire section, including all topics and sections in that section, select Print the selected heading and all subtopics.
5. Click OK.
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter : Introduction
© 2015 Forsk
About Atoll Documentation The following PDF manuals are available for Atoll and Atoll Microwave and can be downloaded from the Forsk web site at: http://www.forsk.com/support. • • • • • •
Atoll 3.3.0 User Manual Atoll 3.3.0 Administrator Manual Atoll 3.3.0 Data Structure Reference Guide Atoll 3.3.0 Technical Reference Guide Atoll 3.3.0 Task Automation Guide Atoll 3.3.0 Model Calibration Guide
To read PDF manuals, you can download Adobe Reader from the Adobe web site at: http://get.adobe.com/reader/ Hardcopy manuals are also available. For more information, contact to your Forsk representative.
Contacting Technical Support Forsk provides global technical support for its products and services. To contact the Forsk support team, visit the Forsk Support web site at: http://www.forsk.com/support. Alternatively, depending on your geographic location, contact one of the following support teams: •
Forsk Head Office For regions other than North and Central America and China, contact the Forsk Head Office support team: • • •
Tel.: +33 562 747 225 Fax: +33 562 747 211 Email:
[email protected]
Opening Hours: Monday to Friday 9.00 am to 6.00 pm (GMT +1:00) •
Forsk US For North and Central America, contact the Forsk US support team: • • •
Tel.: 1-888-GO-ATOLL (1-888-462-8655) Fax: 1-312-674-4822 Email:
[email protected]
Opening Hours: Monday to Friday 8.00 am to 8.00 pm (Eastern Standard Time) •
Forsk China For China, contact the Forsk China support team: • • •
Tel: +86 20 8557 0016 Fax: +86 20 8553 8285 Email:
[email protected]
Opening Hours: Monday to Friday 9.00am to 5.30pm (GMT+08:00) Beijing, Chongqing, Hong Kong, Urumqi.
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
Table of Contents
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 1
Antennas and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
1.1 1.1.1 1.1.2 1.1.3
Antenna Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Calculation of Azimuth and Tilt Angles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Antenna Pattern 3D Interpolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Additional Electrical Downtilt Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.2
Antenna Pattern Smoothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.3
Power Received From Secondary Antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1.4 1.4.1 1.4.2
Transmitter Radio Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 GSM Documents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE Documents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1.5 1.5.1 1.5.1.1 1.5.1.2 1.5.1.3 1.5.1.4 1.5.2 1.5.2.1 1.5.2.2 1.5.3 1.5.3.1 1.5.3.2
Repeaters and Remote Antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE Documents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Signal Level Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Total Gain Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Repeater Noise Figure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Appendix: Carrier Power and Interference Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 GSM Documents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Signal Level Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 EIRP Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Donor-side Parameter Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Azimuth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Mechanical Downtilt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
1.6 1.6.1 1.6.1.1 1.6.1.2 1.6.1.3 1.6.1.4 1.6.2 1.6.3 1.6.4
Beamforming Smart Antenna Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Definitions and Formulas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Downlink Beamforming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Uplink Beamforming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Uplink Beamforming and Interference Cancellation (MMSE). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Downlink Beamforming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Uplink Beamforming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Uplink Beamforming and Interference Cancellation (MMSE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
1.7
Grid-of-Beams Smart Antenna Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
1.8
Adaptive Beam Smart Antenna Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
1.9
Statistical Smart Antenna Gain Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
2
Radio Propagation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
2.1 2.1.1 2.1.2 2.1.2.1 2.1.2.2 2.1.3 2.1.4
Path Loss Calculation Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Ground Altitude Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Clutter Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Clutter Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Clutter Heights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Geographic Profile Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Resolution of the Extracted Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
2.2
List of Default Propagation Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
2.3 2.3.1 2.3.2
Okumura-Hata and Cost-Hata Propagation Models. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Hata Path Loss Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Corrections to the Hata Path Loss Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
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© Forsk 2015
2.3.3
Calculations in Atoll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
2.4 2.4.1 2.4.2 2.4.3
ITU 529-3 Propagation Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64 ITU 529-3 Path Loss Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64 Corrections to the ITU 529-3 Path Loss Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64 Calculations in Atoll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
2.5 2.5.1 2.5.2 2.5.2.1 2.5.2.2 2.5.2.3 2.5.2.4 2.5.2.5 2.5.2.6 2.5.2.7 2.5.3 2.5.3.1 2.5.3.2 2.5.4
Standard Propagation Model (SPM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65 SPM Path Loss Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65 Calculations in Atoll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66 Visibility and Distance Between Transmitter and Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66 Effective Transmitter Antenna Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66 Effective Receiver Antenna Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69 Correction for Hilly Regions in Case of LOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70 Diffraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70 Losses due to Clutter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70 Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71 Automatic Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72 General Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72 Sample Values for SPM Path Loss Formula Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73 Unmasked Path Loss Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
2.6 2.6.1 2.6.2
WLL Propagation Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75 WLL Path Loss Formula. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75 Calculations in Atoll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
2.7 2.7.1 2.7.2
ITU-R P.526-5 Propagation Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76 ITU 526-5 Path Loss Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76 Calculations in Atoll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76
2.8 2.8.1 2.8.2
ITU-R P.370-7 Propagation Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76 ITU 370-7 Path Loss Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76 Calculations in Atoll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76
2.9 2.9.1 2.9.2 2.9.3
Erceg-Greenstein (SUI) Propagation Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78 SUI Terrain Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78 Erceg-Greenstein (SUI) Path Loss Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79 Calculations in Atoll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79
2.10 2.10.1 2.10.1.1 2.10.1.2 2.10.1.3 2.10.1.4 2.10.1.5 2.10.1.6
ITU-R P.1546-2 Propagation Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80 Calculations in Atoll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80 Step 1: Determination of Graphs to be Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80 Step 2: Calculation of Maximum Field Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81 Step 3: Determination of Transmitter Antenna Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81 Step 4: Interpolation/Extrapolation of Field Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81 Step 5: Calculation of Correction Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83 Step 6: Calculation of Path Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84
2.11
Sakagami Extended Propagation Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84
2.12
Free Space Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
2.13 2.13.1 2.13.2 2.13.3 2.13.4 2.13.5
Diffraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86 Knife-edge Diffraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86 3 Knife-edge Deygout Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87 Epstein-Peterson Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89 Deygout Method with Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89 Millington Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89
2.14 2.14.1 2.14.1.1 2.14.1.2 2.14.2 2.14.2.1 2.14.2.1.1 2.14.2.1.2 2.14.2.2 2.14.2.2.1 2.14.2.2.2
Shadow Fading Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90 Shadowing Margin Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95 Shadowing Margin Calculation in Predictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95 Shadowing Margin Calculation in Monte-Carlo Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97 Macro-Diversity Gains Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97 Uplink Macro-Diversity Gain Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98 Shadowing Error PDF (n Signals). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98 Uplink Macro-Diversity Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Downlink Macro-Diversity Gain Evaluation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Shadowing Error PDF (n Signals). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Downlink Macro-Diversity Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
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2.15 2.15.1 2.15.2 2.15.3 2.15.3.1 2.15.3.2
Path Loss Matrices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Calculation Area Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Validity of Path Loss Matrices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Path Loss Tuning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Transmitter Path Loss Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Repeater Path Loss Tuning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
2.16 2.16.1 2.16.1.1 2.16.1.2 2.16.1.3 2.16.2 2.16.2.1 2.16.2.2 2.16.2.3 2.16.3 2.16.3.1 2.16.3.2 2.16.3.3 2.16.3.4 2.16.3.5 2.16.3.6 2.16.4 2.16.4.1 2.16.4.2 2.16.5 2.16.5.1 2.16.5.2 2.16.5.3 2.16.5.4
File Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Path Loss Matrix File Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Pathloss.dbf File Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Pathloss.dbf File Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 LOS File Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Path Loss Tuning File Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Pathloss.dbf File Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Pathloss.dbf File Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 PTS File Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Interference Matrix File Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 CLC Format (One Value per Line). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 CLC File Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 DCT File Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 IM0 Format (One Histogram per Line) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 IM1 Format (One Value per Line, TX Name Repeated) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 IM2 Format (Co- and Adjacent-channel Probabilities) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 "Per Transmitter" Prediction File Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 .dbf File Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 .dbf File Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Coverage Prediction Export and Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Filtering Coverage Predictions at Export. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Smoothing Coverage Predictions at Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Examples of Prediction Export Filtering and Smoothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 Coverage Prediction Reports Over Focus/Computation Zones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
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GSM GPRS EDGE Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125
3.1 3.1.1 3.1.2 3.1.3 3.1.3.1 3.1.3.2 3.1.4 3.1.4.1 3.1.4.1.1 3.1.4.1.2 3.1.4.1.3 3.1.4.1.4 3.1.4.1.5 3.1.4.1.6 3.1.4.1.7 3.1.4.1.8 3.1.4.2 3.1.4.2.1 3.1.4.2.2
Signal Level Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 DL Signal Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 UL Signal Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 Point Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Profile Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Reception Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Signal Level-based DL Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 DL Service Area Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 All Servers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Best Signal Level and a Margin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Second Best Signal Level and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Best Signal Level per HCS Layer and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Second Best Signal Level per HCS Layer and a Margin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 HCS Servers and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 Highest Priority HCS Server and a Margin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 Best Idle Mode Reselection Criterion (C2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 Coverage Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 Coverage Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 Display Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
3.2 3.2.1 3.2.2 3.2.3 3.2.3.1 3.2.3.2 3.2.3.2.1 3.2.3.2.2 3.2.3.3 3.2.3.3.1 3.2.3.3.2
Interference-based DL Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 DL Carrier-to-Interference Ratio Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 Point Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Interference-based DL Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Service Area Determination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Coverage Area Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Interference Condition Satisfied by At Least One TRX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Interference Condition Satisfied by The Worst TRX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Coverage Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Coverage Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Display Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
3.3 3.3.1
GPRS/EDGE Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Coding Scheme Selection and Throughput Calculation Without Ideal Link Adaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
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© Forsk 2015
3.3.1.1 3.3.1.2 3.3.1.3 3.3.2 3.3.2.1 3.3.2.2 3.3.2.3 3.3.3 3.3.4 3.3.5 3.3.5.1 3.3.5.1.1 3.3.5.1.2 3.3.5.1.3 3.3.5.1.4 3.3.5.1.5 3.3.5.1.6 3.3.5.1.7 3.3.5.1.8 3.3.5.2 3.3.5.2.1 3.3.5.2.2
Calculations Based on C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculations Based on C/I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculations Based on C/(I+N) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coding Scheme Selection and Throughput Calculation With Ideal Link Adaptation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculations Based on C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculations Based on C/I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculations Based on C/(I+N) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Application Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BLER Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPRS/EDGE Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Area Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . All Servers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Signal Level and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Second Best Signal Level and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Signal Level per HCS Layer and a Margin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Second Best Signal Level per HCS Layer and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HCS Servers and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Highest Priority HCS Server and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Idle Mode Reselection Criterion (C2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Display Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
137 137 137 138 138 138 139 139 140 140 140 140 140 141 141 141 141 142 142 142 142 143
3.4 3.4.1 3.4.2 3.4.2.1 3.4.2.2 3.4.3 3.4.3.1 3.4.3.2 3.4.4 3.4.4.1 3.4.4.1.1 3.4.4.1.2 3.4.4.1.3 3.4.4.1.4 3.4.4.1.5 3.4.4.1.6 3.4.4.1.7 3.4.4.2 3.4.4.2.1 3.4.4.2.2
Codec Mode Selection and CQI Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Circuit Quality Indicator Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CQI Calculation Without Ideal Link Adaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculations Based on C/N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculations Based on C/(I+N) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CQI Calculation With Ideal Link Adaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculations Based on C/N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculations Based on C/(I+N) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Circuit Quality Indicators Coverage Predictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Area Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . All Servers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Signal Level and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Second Best Signal Level and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Signal Level per HCS Layer and a Margin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Second Best Signal Level per HCS Layer and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HCS Servers and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Highest Priority HCS Server and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Display Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
145 147 147 147 148 148 148 148 149 149 149 149 150 150 150 150 151 151 151 151
3.5 3.5.1 3.5.1.1 3.5.1.2 3.5.1.3 3.5.1.4 3.5.1.5 3.5.1.6 3.5.1.7 3.5.1.8 3.5.2 3.5.2.1 3.5.2.2 3.5.2.2.1 3.5.2.2.2 3.5.2.2.3 3.5.2.2.4 3.5.3 3.5.3.1 3.5.3.2 3.5.3.3 3.5.3.4 3.5.3.4.1
UL Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DL Service Area Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . All Servers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Signal Level and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Second Best Signal Level and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Signal Level per HCS Layer and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Second Best Signal Level per HCS Layer and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HCS Servers and a Margin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Highest Priority HCS Server and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Idle Mode Reselection Criterion (C2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage by UL Signal Level. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Display Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UL Signal Level (in dBm, dBµV, dBµV/m) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best UL Signal Level (in dBm, dBµV, dBµV/m). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UL Total Losses (dB). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Minimum UL Total Losses (dB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage by UL C/I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UL C/I Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Area Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Display Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C/I Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
152 152 152 152 153 153 153 154 154 155 155 155 155 155 155 156 156 156 156 156 156 156 156
AT330_TRR_E1
Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
3.5.3.4.2 3.5.3.4.3 3.5.4 3.5.4.1 3.5.4.2 3.5.4.3 3.5.5 3.5.5.1 3.5.5.2
Max C/I Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 Min C/I Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 Coverage by UL Coding Schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 Service Area Determination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 Coding Scheme Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 Coverage by UL Codec Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 Service Area Determination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Codec Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
3.6 3.6.1 3.6.1.1 3.6.1.1.1 3.6.1.1.2 3.6.1.2 3.6.1.2.1 3.6.1.2.2 3.6.1.3 3.6.1.3.1 3.6.1.3.2 3.6.2 3.6.2.1 3.6.2.1.1 3.6.2.1.2 3.6.2.1.3 3.6.2.2 3.6.2.2.1 3.6.2.2.2 3.6.2.2.3
Traffic Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Traffic Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Normal Cells (Nonconcentric, No HCS Layer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Circuit Switched Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Packet Switched Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Concentric Cells. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Circuit Switched Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Packet Switched Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 HCS Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Circuit Switched Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Packet Switched Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Calculation of the Traffic Demand per Subcell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 User Profile Traffic Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Normal Cells (Nonconcentric, No HCS Layer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Concentric Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 HCS Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 Sector Traffic Maps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 Normal Cells (Nonconcentric, No HCS Layer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 Concentric Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 HCS Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
3.7 3.7.1 3.7.1.1 3.7.1.2 3.7.1.2.1 3.7.1.2.2 3.7.1.2.3 3.7.2 3.7.2.1 3.7.2.1.1 3.7.2.1.2 3.7.2.2 3.7.2.2.1 3.7.2.2.2 3.7.2.2.3 3.7.2.2.4 3.7.2.2.5 3.7.2.2.6
Network Dimensioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Dimensioning Models and Quality Graphs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Circuit Switched Traffic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Packet Switched Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 Throughput . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 Delay. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 Blocking Probability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 Network Dimensioning Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 Network Dimensioning Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Network Dimensioning Steps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Step 1: Timeslots Required for CS Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Step 2: TRXs Required for CS Traffic and Dedicated PS Timeslots . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 Step 3: Effective CS Blocking, Effective CS Traffic Overflow and Served CS Traffic . . . . . . . . . . . . . . . 178 Step 4: TRXs to Add for PS Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 Step 5: Served PS Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 Step 6: Total Traffic Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
3.8 3.8.1 3.8.1.1 3.8.1.2 3.8.1.3 3.8.2 3.8.2.1 3.8.2.1.1 3.8.2.1.2 3.8.2.1.3 3.8.2.1.4 3.8.2.1.5 3.8.2.1.6 3.8.2.2 3.8.2.2.1 3.8.2.2.2 3.8.2.2.3 3.8.2.2.4
Key Performance Indicators Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 Circuit Switched Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 Erlang B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 Erlang C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 Served Circuit Switched Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Packet Switched Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Case 1: Total Traffic Demand > Dedicated + Shared Timeslots. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Traffic Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Packet Switched Traffic Overflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Throughput Reduction Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Delay. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Blocking Probability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Served Packet Switched Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Case 2: Total Traffic Demand < Dedicated + Shared Timeslots. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Traffic Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Packet Switched Traffic Overflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Throughput Reduction Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Delay. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
3.8.2.2.5 3.8.2.2.6
© Forsk 2015
Blocking Probability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Served Packet Switched Traffic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
3.9 3.9.1 3.9.1.1 3.9.1.2 3.9.1.3 3.9.1.4 3.9.1.5 3.9.1.6 3.9.1.7 3.9.1.8 3.9.1.9
Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radio Resource Management in GSM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSM Simulation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Servers Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Codec Mode Assignment and DL Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coding Scheme Assignment, Throughput Evaluation and DL Power Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Subcell Traffic Loads Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Half-Rate Traffic Ratio Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DL Power Control Gain Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DTX DL Gain Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSM Simulation Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
184 184 184 187 187 188 189 189 189 190 190
3.10 3.10.1 3.10.2 3.10.3 3.10.4
Automatic Neighbour Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Neighbour Allocation for All Transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Neighbour Allocation for a Group of Transmitters or One Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Neighbour Importance Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendix: Calculation of the Inter-Transmitter Distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
191 191 194 194 195
3.11 3.11.1 3.11.1.1 3.11.1.2 3.11.1.2.1 3.11.1.2.2 3.11.1.2.3 3.11.2 3.11.2.1 3.11.2.2 3.11.2.3 3.11.3 3.11.3.1 3.11.3.2 3.11.3.3 3.11.3.4 3.11.3.4.1 3.11.3.4.2 3.11.3.4.3 3.11.3.5
AFP Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The AFP Cost Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cost Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cost Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Separation Violation Cost Component. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interference Cost Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I_DIV, F_DIV and Other Advanced Cost Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The AFP Blocked Traffic Cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation of New Traffic Loads Including Blocked Traffic Loads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recalculation of CS and PS From Traffic Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Testing the Blocked Cost Using Traffic Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using Interferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cumulative Density Function of C/I Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Precise Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Precise Interference Distribution Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Direct Availability of Precise Interference Distribution to the AFP . . . . . . . . . . . . . . . . . . . . . . . . . . . Efficient Calculation and Storage of Interference Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Robustness of the IM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic Load and Interference Information Discrimination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
196 196 197 198 198 200 201 202 203 204 205 205 205 205 206 206 206 206 206 207
4
UMTS HSPA Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
4.1 4.1.1 4.1.2 4.1.2.1 4.1.2.2 4.1.3 4.1.3.1 4.1.3.1.1 4.1.3.1.2 4.1.3.1.3 4.1.3.2 4.1.3.2.1 4.1.3.2.2
General Prediction Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Point Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Profile Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reception Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Area Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . All Servers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Signal Level and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Second Best Signal Level and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Plot Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Display Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
211 211 211 211 212 212 212 212 212 213 213 213 213
4.2 4.2.1 4.2.2 4.2.3 4.2.4 4.2.5
Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ec/I0 Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DL Eb/Nt Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UL Eb/Nt Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
214 214 215 222 223 224
4.3 4.3.1 4.3.1.1
Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 Generating a Realistic User Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 Simulations Based on User Profile Traffic Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
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4.3.1.1.1 4.3.1.1.2 4.3.1.2 4.3.1.2.1 4.3.1.2.2 4.3.1.2.3 4.3.2 4.3.2.1 4.3.2.2 4.3.2.3 4.3.2.3.1 4.3.2.3.2 4.3.2.3.3 4.3.2.3.4 4.3.2.3.5 4.3.2.3.6 4.3.2.3.7 4.3.2.4 4.3.2.4.1 4.3.2.4.2 4.3.2.4.3 4.3.2.4.4 4.3.2.5 4.3.3 4.3.3.1 4.3.3.2 4.3.3.2.1 4.3.3.2.2 4.3.3.2.3 4.3.3.2.4 4.3.4 4.3.4.1 4.3.4.2 4.3.4.2.1 4.3.4.2.2 4.3.4.2.3 4.3.4.3 4.3.4.3.1 4.3.4.3.2 4.3.4.4 4.3.4.5 4.3.4.6
Circuit Switched Service (i) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 Packet Switched Service (j). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 Simulations Based on Sector Traffic Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 Throughputs in Uplink and Downlink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 Total Number of Users (All Activity Statuses) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 Number of Users per Activity Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 Power Control Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 Algorithm Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 R99 Part of the Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 HSDPA Part of the Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 HSDPA Power Allocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 Number of HS-SCCH Channels and Maximum Number of HSDPA Bearer Users . . . . . . . . . . . . . . . . . 238 HSDPA Bearer Allocation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 Fast Link Adaptation Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 MIMO Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 Scheduling Algorithms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 Dual-Cell HSDPA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 HSUPA Part of the Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 Admission Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 HSUPA Bearer Allocation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 Noise Rise Scheduling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 Radio Resource Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 Convergence Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 R99 Related Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 HSPA Related Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 Statistics Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 Mobiles Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 Cells Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 Sites Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 Admission Control in the R99 Part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 Resources Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 OVSF Codes Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 Channel Elements Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 Iub Backhaul Throughput . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 Downlink Load Factor Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Downlink Load Factor per Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Downlink Load Factor per Mobile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 Uplink Load Factor Due to One User . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 Inter-carrier Power Sharing Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 Best Serving Cell Determination in Monte Carlo Simulations - Old Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
4.4 4.4.1 4.4.2 4.4.2.1 4.4.2.2 4.4.2.3 4.4.2.4 4.4.2.5 4.4.3 4.4.3.1 4.4.3.1.1 4.4.3.1.2 4.4.3.2 4.4.3.2.1 4.4.3.2.2 4.4.3.3 4.4.3.3.1 4.4.3.3.2 4.4.3.4 4.4.3.4.1 4.4.3.4.2 4.4.3.5 4.4.3.5.1 4.4.3.5.2
UMTS HSPA Prediction Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 Best Serving Cell and Active Set Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 Point Analysis - AS Analysis Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285 Bar Graph and Pilot Sub-Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285 Downlink R99 Sub-Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 Uplink R99 Sub-Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 HSDPA Sub-Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 HSUPA Sub-Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 Coverage Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 Pilot Quality Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 Prediction Study Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 Study Display Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 Downlink Service Area Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 Prediction Study Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 Study Display Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 Uplink Service Area Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 Prediction Study Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 Study Display Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 Downlink Total Noise Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 Study Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 Display Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 HSDPA Prediction Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 Prediction Study Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305 Study Display Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
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4.4.3.6 4.4.3.6.1 4.4.3.6.2 4.4.3.6.3
© Forsk 2015
HSUPA Prediction Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Prediction Study Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Display Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
309 309 310 310
4.5 4.5.1 4.5.2 4.5.3 4.5.3.1 4.5.3.2 4.5.4 4.5.4.1
Automatic Neighbour Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Neighbour Allocation for All Transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Neighbour Allocation for a Group of Transmitters or One Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Importance Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Importance of Intra-carrier Neighbours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Importance of Inter-carrier Neighbours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation of the Inter-Transmitter Distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
312 312 316 316 316 318 319 319
4.6 4.6.1 4.6.1.1 4.6.1.2 4.6.1.2.1 4.6.1.2.2 4.6.1.3 4.6.1.3.1 4.6.1.3.2 4.6.1.3.3 4.6.2 4.6.2.1 4.6.2.1.1 4.6.2.1.2 4.6.2.1.3 4.6.2.1.4 4.6.2.2
Primary Scrambling Code Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Automatic Allocation Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Options and Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Allocation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Single Carrier Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multi-Carrier Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Priority Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cell Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmitter Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Site Priority. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Allocation Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Allocation Strategies and Use a Maximum of Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Strategy: Clustered . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Strategy: Distributed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Strategy: ‘One Cluster per Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Strategy: ‘Distributed per Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Allocate Carriers Identically . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
319 320 320 321 321 322 323 323 325 325 326 326 326 327 328 328 329
4.7 4.7.1 4.7.2 4.7.2.1 4.7.2.2 4.7.2.3 4.7.2.3.1
Automatic GSM-UMTS Neighbour Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Automatic Allocation Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Algorithm Based on Distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Algorithm Based on Coverage Overlapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Delete Existing Neighbours Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
329 329 330 330 331 333 333
5
CDMA2000 Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
5.1 5.1.1 5.1.2 5.1.2.1 5.1.2.2 5.1.3 5.1.3.1 5.1.3.1.1 5.1.3.1.2 5.1.3.1.3 5.1.3.2 5.1.3.2.1 5.1.3.2.2
General Prediction Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Point Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Profile Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reception Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Area Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . All Servers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Signal Level and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Second Best Signal Level and a Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Plot Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Display Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
337 337 338 338 338 338 338 338 338 339 339 339 339
5.2 5.2.1 5.2.1.1 5.2.1.2 5.2.1.3 5.2.1.4 5.2.1.5 5.2.2 5.2.2.1 5.2.2.2 5.2.2.3 5.2.2.4
Definitions and Formulas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Parameters Used for CDMA2000 1xRTT Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ec/I0 Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DL Eb/Nt Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UL Eb/Nt Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulation Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Parameters Used for CDMA2000 1xEV-DO Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ec/I0 and Ec/Nt Calculations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UL Eb/Nt Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulation Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
340 340 340 345 346 347 348 350 350 354 355 356
12
AT330_TRR_E1
Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
5.3
Active Set Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
5.4 5.4.1 5.4.1.1 5.4.1.1.1 5.4.1.1.2 5.4.1.2 5.4.1.3 5.4.2 5.4.2.1 5.4.2.1.1 5.4.2.1.2 5.4.2.1.3 5.4.2.2 5.4.2.2.1 5.4.2.2.2 5.4.2.2.3 5.4.3 5.4.3.1 5.4.3.2 5.4.3.2.1 5.4.3.2.2 5.4.3.3 5.4.3.3.1 5.4.3.3.2 5.4.3.4 5.4.3.5
Simulations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358 Generating a Realistic User Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 Number of Users, User Activity Status and User Throughput. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 Simulations Based on User Profile Traffic Maps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 Simulations Based on Sector Traffic Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 Transition Flags for 1xEV-DO Rev.0 User Throughputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 User Geographical Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 Network Regulation Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 CDMA2000 1xRTT Power Control Simulation Algorithm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 Algorithm Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 Presentation of the Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 Convergence Criterion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376 CDMA2000 1xEV-DO Power/Data Rate Control Simulation Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 Algorithm Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 Presentation of the Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 Convergence Criterion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385 Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386 Admission Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386 Resources Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386 Walsh Code Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386 Channel Element Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 Downlink Load Factor Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388 Downlink Load Factor per Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388 Downlink Load Factor per Mobile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389 Best Server Determination in Monte Carlo Simulations - Old Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389 Radio Bearer Allocation Algorithm for Multi-carrier EVDO Rev.B - Old Method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392
5.5 5.5.1 5.5.1.1 5.5.1.2 5.5.1.2.1 5.5.1.2.2 5.5.1.3 5.5.1.3.1 5.5.1.3.2 5.5.2 5.5.2.1 5.5.2.2 5.5.2.2.1 5.5.2.2.2 5.5.2.3 5.5.2.3.1 5.5.2.3.2 5.5.2.4 5.5.2.4.1 5.5.2.4.2
CDMA2000 Prediction Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392 Point Analysis: The AS Analysis Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392 Bar Graph and Pilot Sub-Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392 Downlink Sub-Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395 CDMA2000 1xRTT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395 CDMA2000 1xEV-DO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 Uplink Sub-Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402 CDMA2000 1xRTT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402 CDMA2000 1xEV-DO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406 Coverage Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412 Pilot Quality Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412 Downlink Service Area Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413 CDMA2000 1xRTT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413 CDMA2000 1xEV-DO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415 Uplink Service Area Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417 CDMA2000 1xRTT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417 CDMA2000 1xEV-DO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419 Downlink Total Noise Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 Analysis on the Best Carrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 Analysis on a Specific Carrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423
5.6 5.6.1 5.6.2 5.6.3 5.6.3.1 5.6.3.2 5.6.4 5.6.4.1
Automatic Neighbour Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423 Neighbour Allocation for all Transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424 Neighbour Allocation for a Group of Transmitters or One Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427 Importance Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428 Importance of Intra-carrier Neighbours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428 Importance of Inter-carrier Neighbours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430 Calculation of the Inter-Transmitter Distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
5.7 5.7.1 5.7.1.1 5.7.1.2 5.7.1.2.1 5.7.1.2.2 5.7.1.2.3 5.7.1.3 5.7.1.3.1
PN Offset Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430 Automatic Allocation Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 Options and Constraints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 Allocation Process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 Single Carrier Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 Multi-Carrier Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 Difference between Adjacent and Distributed PN-Clusters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 Priority Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 Cell Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433
13
Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
5.7.1.3.2 5.7.1.3.3 5.7.2 5.7.2.1 5.7.2.2 5.7.2.3 5.8 5.8.1 5.8.2 5.8.2.1 5.8.2.2 5.8.2.3
6
© Forsk 2015
Transmitter Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Site Priority. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Allocation Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Strategy: PN Offset per Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Strategy: Adjacent PN-Clusters Per Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Strategy: ‘Distributed PN-Clusters Per Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
435 436 436 436 437 437
Automatic GSM-CDMA Neighbour Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Automatic Allocation Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Algorithm Based on Distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Algorithm Based on Coverage Overlapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Delete Existing Neighbours Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
438 438 438 438 439 441
LTE Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445
6.1
Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445
6.2 6.2.1 6.2.2 6.2.3 6.2.4 6.2.5 6.2.6 6.2.7 6.2.8 6.2.9 6.2.10 6.2.11 6.2.12 6.2.13 6.2.14 6.2.15 6.2.16 6.2.17 6.2.18 6.2.19 6.2.20
Calculation Quick Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Downlink Transmission Powers Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Co- and Adjacent Channel Overlaps Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Signal Level Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Noise Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interference Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C/N Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C/(I+N) Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Signal Level Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Noise Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interference Calculation (UL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Noise Rise Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C/N Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C/(I+N) Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation of Downlink Cell Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation of Uplink Cell Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation of Downlink UE Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation of Uplink UE Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation . . . . . . . Scheduling and Radio Resource Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . User Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
450 450 453 453 455 456 460 460 462 462 462 463 463 463 464 465 465 465 466 467 469
6.3 6.3.1 6.3.1.1 6.3.1.2 6.3.1.3 6.3.1.4 6.3.2 6.3.2.1 6.3.2.2 6.3.2.3 6.3.2.4 6.3.3 6.3.4 6.3.4.1 6.3.4.1.1 6.3.4.1.2 6.3.4.2
Available Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Point Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Profile View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reception View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interference View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Details View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Downlink Signal Level Coverage Predictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effective Signal Analysis Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C/(I+N)-based Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cell Identifier Collision Zones Coverage Prediction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculations on Subscriber Lists. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Monte Carlo Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . User Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulations Based on User Profile Traffic Maps and Subscriber Lists . . . . . . . . . . . . . . . . . . . . . . . . . Simulations Based on Sector Traffic Maps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
470 470 470 470 470 470 471 471 472 473 475 476 476 476 476 478 479
6.4 6.4.1 6.4.2 6.4.2.1 6.4.2.2 6.4.2.3 6.4.2.4 6.4.3 6.4.3.1 6.4.3.2
Calculation Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Downlink Transmission Power Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Co- and Adjacent Channel Overlaps Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conversion From Channel Numbers to Start and End Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Co-Channel Overlap Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Adjacent Channel Overlap Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Total Overlap Ratio Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Subframe Pattern Collision Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Subframe Pattern Normalisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Determination of Effective Subframe Patterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
485 485 493 494 495 496 496 497 497 498
14
AT330_TRR_E1
6.4.3.3 6.4.4 6.4.4.1 6.4.4.2 6.4.4.3 6.4.4.4 6.4.4.5 6.4.4.6 6.4.4.7 6.4.4.8 6.4.4.8.1 6.4.4.8.2 6.4.4.9 6.4.4.10 6.4.5 6.4.6 6.4.6.1 6.4.6.1.1 6.4.6.1.2 6.4.6.2 6.4.6.2.1 6.4.6.2.2 6.4.6.3 6.4.7 6.4.7.1 6.4.7.2 6.5 6.5.1 6.5.2 6.5.3 6.5.3.1 6.5.3.2 6.5.3.3 6.5.4 6.5.4.1 6.5.4.2 6.5.4.3 6.5.5 6.5.5.1 6.5.5.2 6.5.5.3 6.5.6 6.5.6.1 6.5.6.2
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
Calculation of Subframe Collision Probabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 499 Signal Level and Signal Quality Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501 Signal Level Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501 Noise Calculation (DL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505 Interference Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505 C/N Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516 C/(I+N) and Bearer Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518 Signal Level Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523 Noise Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525 Interference Calculation (UL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525 Interfering Signal Level Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 526 Noise Rise Calculation (UL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528 C/N Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529 C/(I+N) and Bearer Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532 Best Server Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535 Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 538 Calculation of Total Cell Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 538 Calculation of Downlink Cell Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 538 Calculation of Uplink Cell Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543 Calculation UE Capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545 Calculation of Downlink UE Capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545 Calculation of Uplink UE Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 546 Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation . . . . . . 547 Scheduling and Radio Resource Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 552 Scheduling and Radio Resource Allocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 552 User Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 561 Automatic Planning Algorithms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 563 Automatic Neighbour Planning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 563 Automatic Inter-technology Neighbour Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 567 Automatic Frequency Planning Using the AFP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 570 Constraint and Relationship Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 570 Cost Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571 AFP Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571 Automatic Physical Cell ID Planning Using the AFP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572 Constraint and Relationship Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572 Cost Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 574 AFP Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 576 Automatic PRACH RSI Planning Using the AFP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 576 Constraint and Relationship Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 576 Cost Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577 AFP Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 578 Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 578 Interference Matrix Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 578 Distance Importance Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 579
3GPP Multi-RAT Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .583
7.1
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 583
7.2 7.2.1 7.2.2
Multi-RAT Monte Carlo Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 583 User Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 583 Simulation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585
7.3
Multi-RAT Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585
8
3GPP2 Multi-RAT Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .589
8.1
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 589
8.2 8.2.1 8.2.2
Multi-RAT Monte Carlo Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 589 User Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 589 Simulation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 590
8.3
Multi-RAT Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 591
9
TD-SCDMA Networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .595 15
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© Forsk 2015
9.1 9.1.1 9.1.2 9.1.3 9.1.4 9.1.5 9.1.6 9.1.7
Definitions and Formulas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-CCPCH Eb/Nt and C/I Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DwPCH C/I Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DL TCH Eb/Nt and C/I Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UL TCH Eb/Nt and C/I Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interference Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HSDPA Dynamic Power Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
595 595 600 600 601 601 602 602
9.2 9.2.1 9.2.1.1 9.2.1.2 9.2.2 9.2.2.1 9.2.2.2 9.2.2.2.1 9.2.2.2.2 9.2.2.3 9.2.2.4 9.2.2.5 9.2.2.5.1 9.2.2.5.2 9.2.2.6 9.2.2.6.1 9.2.2.6.2 9.2.2.7 9.2.2.7.1 9.2.2.7.2 9.2.2.8
Signal Level Based Calculations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Point Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Profile Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reception Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RSCP Based Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-CCPCH RSCP Coverage Prediction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Server P-CCPCH Coverage Prediction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-CCPCH Pollution Analysis Coverage Prediction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DwPCH RSCP Coverage Prediction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UpPCH RSCP Coverage Prediction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Baton Handover Coverage Prediction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scrambling Code Interference Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
602 602 603 603 603 603 604 604 604 605 605 605 605 606 606 606 606 607 607 607 607
9.3 9.3.1 9.3.1.1 9.3.1.1.1 9.3.1.1.2 9.3.1.2 9.3.1.2.1 9.3.1.2.2 9.3.1.2.3 9.3.2 9.3.2.1 9.3.2.2 9.3.2.2.1 9.3.2.2.2 9.3.2.2.3 9.3.2.2.4 9.3.2.2.5 9.3.2.2.6 9.3.2.2.7 9.3.2.3 9.3.2.3.1 9.3.2.3.2 9.3.2.3.3 9.3.2.3.4 9.3.2.3.5 9.3.2.4
Monte Carlo Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Generating a Realistic User Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulations Based on User Profile Traffic Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Circuit Switched Service (i) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Packet Switched Service (j) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulations Based on Sector Traffic Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Throughputs in Uplink and Downlink. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Total Number of Users (All Activity Statuses) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Number of Users per Activity Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power Control Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Algorithm Initialisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R99 Part of the Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Determination of Mi’s Best Server (SBS(Mi)) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dynamic Channel Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Uplink Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Downlink Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Uplink Signals Update . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Downlink Signals Update. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control of Radio Resource Limits (Downlink Traffic Power and Uplink Load) . . . . . . . . . . . . . . . . . . HSDPA Part of the Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HSDPA Power Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Connection Status and Number of HSDPA Users . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HSDPA Admission Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HSDPA Dynamic Channel Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ressource Unit Saturation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Convergence Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
608 608 608 609 609 612 612 613 613 613 614 614 614 615 617 619 621 621 621 622 622 624 624 625 625 625
9.4 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.4.9
TD-SCDMA Prediction Studies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-CCPCH Reception Analysis (Eb/Nt) or (C/I) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DwPCH Reception Analysis (C/I) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Downlink TCH RSCP Coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Uplink TCH RSCP Coverage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Downlink Total Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Downlink Service Area Analysis (Eb/Nt) or (C/I). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Uplink Service Area Analysis (Eb/Nt) or (C/I) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effective Service Area Analysis (Eb/Nt) or (C/I) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cell to Cell Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
626 626 628 629 630 631 631 633 635 636
16
AT330_TRR_E1
9.4.10 9.4.11
Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
UpPCH Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 637 HSDPA Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 637
9.5 9.5.1 9.5.1.1 9.5.1.2 9.5.1.3 9.5.1.4 9.5.1.5 9.5.2 9.5.3 9.5.4 9.5.4.1 9.5.4.1.1 9.5.4.1.2 9.5.4.2 9.5.4.2.1 9.5.4.2.2 9.5.4.2.3
Smart Antenna Modelling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 638 Modelling in Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 639 Grid of Beams Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 639 Adaptive Beam Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 640 Statistical Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 641 Beamforming Smart Antenna Models. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 641 3rd Party Smart Antenna Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 642 Construction of the Geographic Distributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 642 Modelling in Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 643 HSDPA Quality and Throughput Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 644 Fast Link Adaptation Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 644 CQI Based on P-CCPCH Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 644 CQI Based on HS-PDSCH Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 648 Coverage Prediction Display Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 649 Colour per CQI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 649 Colour per Peak Throughput . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 650 Colour per HS-PDSCH Ec/Nt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 650
9.6 9.6.1
N-Frequency Mode and Carrier Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 650 Automatic Carrier Allocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 650
9.7 9.7.1 9.7.2 9.7.3 9.7.4
Neighbour Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 651 Neighbour Allocation for All Transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 651 Neighbour Allocation for a Group of Transmitters or One Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 655 Importance Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 655 Appendix: Calculation of the Inter-Transmitter Distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 656
9.8 9.8.1 9.8.1.1 9.8.1.2 9.8.1.3 9.8.1.3.1 9.8.1.3.2 9.8.1.4 9.8.1.4.1 9.8.1.4.2 9.8.1.4.3 9.8.2 9.8.2.1 9.8.2.1.1 9.8.2.1.2 9.8.2.1.3 9.8.2.1.4 9.8.2.2
Scrambling Code Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 656 Automatic Allocation Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 657 Allocation Constraints and Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 657 Allocation Strategies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 658 Allocation Process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 658 Single Carrier Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 658 Multi-Carrier Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 659 Priority Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 660 Cell Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 660 Transmitter Priority. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 662 Site Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 663 Scrambling Code Allocation Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 663 Single Carrier Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 663 Strategy: Clustered . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 664 Strategy: Distributed per Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 664 Strategy: One SYNC_DL Code per Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 665 Strategy: Distributed per Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 665 Multi Carrier Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 665
9.9 9.9.1 9.9.1.1 9.9.1.2 9.9.1.3 9.9.1.3.1
Automatic GSM/TD-SCDMA Neighbour Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 666 Automatic Allocation Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 666 Algorithm Based on Distance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 667 Algorithm Based on Coverage Overlapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 667 Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 669 Delete Existing Neighbours Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 669
10
WiMAX BWA Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .673
10.1
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 673
10.2 10.2.1 10.2.2 10.2.3 10.2.4 10.2.5 10.2.6 10.2.7
Calculation Quick Reference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 678 Co- and Adjacent Channel Overlaps Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 678 Preamble Signal Level Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679 Preamble Noise Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679 Preamble Interference Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679 Preamble C/N Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679 Preamble C/(I+N) Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 680 Traffic and Pilot Signal Level Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 680
17
Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
10.2.8 10.2.9 10.2.10 10.2.11 10.2.12 10.2.13 10.2.14 10.2.15 10.2.16 10.2.17 10.2.18 10.2.19 10.2.20
© Forsk 2015
Traffic and Pilot Noise Calculation (DL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic and Pilot Interference Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic and Pilot C/N Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic and Pilot C/(I+N) Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic Signal Level Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic Noise Calculation (UL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic Interference Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic C/N Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic C/(I+N) Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation of Total Cell Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation . . . . . . . Scheduling and Radio Resource Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . User Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
680 681 682 682 683 683 683 684 684 684 685 687 689
10.3 10.3.1 10.3.1.1 10.3.1.2 10.3.1.3 10.3.1.4 10.3.2 10.3.2.1 10.3.2.2 10.3.2.3 10.3.2.4 10.3.3 10.3.4 10.3.4.1 10.3.4.1.1 10.3.4.1.2 10.3.4.2
Available Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Point Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Profile View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reception View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interference View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Details View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preamble Signal Level Coverage Predictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effective Signal Analysis Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C/(I+N)-based Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cell Identifier Collision Zones Coverage Prediction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculations on Subscriber Lists. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Monte Carlo Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . User Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulations Based on User Profile Traffic Maps and Subscriber Lists . . . . . . . . . . . . . . . . . . . . . . . . . Simulations Based on Sector Traffic Maps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
690 690 690 690 690 690 691 691 692 693 695 695 696 696 696 698 699
10.4 10.4.1 10.4.1.1 10.4.1.2 10.4.1.3 10.4.1.4 10.4.1.5 10.4.2 10.4.2.1 10.4.2.2 10.4.2.3 10.4.2.4 10.4.2.5 10.4.3 10.4.4 10.4.5 10.4.6 10.4.6.1 10.4.6.2 10.4.6.3 10.4.6.3.1 10.4.6.3.2 10.4.6.4 10.4.6.5 10.4.6.6 10.4.6.7 10.4.6.8 10.4.6.8.1 10.4.6.8.2 10.4.6.9 10.4.6.10 10.4.7 10.4.7.1 10.4.7.1.1 10.4.7.1.2
Calculation Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Co- and Adjacent Channel Overlaps Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conversion From Channel Numbers to Start and End Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Co-Channel Overlap Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Adjacent Channel Overlap Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FDD – TDD Overlap Ratio Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Total Overlap Ratio Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preamble Signal Level and Quality Calculations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preamble Signal Level Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preamble Noise Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preamble Interference Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preamble C/N Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preamble C/(I+N) Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Server Determination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Area Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Permutation Zone Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic and Pilot Signal Level and Quality Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic and Pilot Signal Level Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic and Pilot Noise Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic and Pilot Interference Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic and Pilot Interference Signal Levels Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effective Traffic and Pilot Interference Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic and Pilot C/N Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic and Pilot C/(I+N) and Bearer Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic Signal Level Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic Noise Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic Interference Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic Interference Signal Levels Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Noise Rise Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic C/N Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic C/(I+N) and Bearer Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation of Total Cell Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation of Sampling Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation of Symbol Duration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
702 702 703 704 705 705 706 707 707 708 710 712 712 713 714 714 715 715 717 718 718 722 726 727 729 730 731 731 733 734 737 740 740 740 741
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10.4.7.1.3 10.4.7.1.4 10.4.7.2 10.4.8 10.4.8.1 10.4.8.2 10.5 10.5.1 10.5.2 10.5.3 10.5.3.1 10.5.3.2 10.5.3.3 10.5.4 10.5.4.1 10.5.4.2 10.5.4.3 10.5.5 10.5.5.1 10.5.5.2 10.5.5.3 10.5.6 10.5.6.1 10.5.6.2
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
Calculation of Total Cell Resources - TDD Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 741 Calculation of Total Cell Resources - FDD Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 742 Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation . . . . . . 743 Scheduling and Radio Resource Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 748 Scheduling and Radio Resource Allocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 748 User Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 757 Automatic Planning Algorithms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 758 Automatic Neighbour Planning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 759 Automatic Inter-technology Neighbour Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 763 Automatic Frequency Planning Using the AFP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 765 Constraint and Relationship Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 766 Cost Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 766 AFP Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 767 Automatic Preamble Index Planning Using the AFP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 767 Constraint and Relationship Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 768 Cost Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 769 AFP Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 771 Automatic Zone PermBase Planning Using the AFP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 771 Constraint and Relationship Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 772 Cost Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 772 AFP Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 774 Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 774 Interference Matrix Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 774 Distance Importance Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 774
Wi-Fi Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .779
11.1
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 779
11.2 11.2.1 11.2.2 11.2.3 11.2.4 11.2.5 11.2.6 11.2.7 11.2.8 11.2.9 11.2.10 11.2.11 11.2.12 11.2.13 11.2.14 11.2.15
Calculation Quick Reference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 782 Co- and Adjacent Channel Overlaps Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 782 Signal Level Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 783 Noise Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 783 Interference Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 783 C/N Calculation (DL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 784 C/(I+N) Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 784 Signal Level Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 784 Noise Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 784 Interference Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 784 C/N Calculation (UL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 785 C/(I+N) Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 785 Calculation of Total Cell Resources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 785 Channel Throughput, Cell Capacity, and Per-user Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 786 Scheduling and Radio Resource Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 787 User Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 788
11.3 11.3.1 11.3.1.1 11.3.1.2 11.3.1.3 11.3.2 11.3.2.1 11.3.2.2 11.3.2.3 11.3.3 11.3.4 11.3.4.1 11.3.4.1.1 11.3.4.1.2 11.3.4.2
Available Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 789 Point Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 789 Profile View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 789 Reception View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 789 Interference View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 789 Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 789 Signal Level Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 789 Effective Signal Analysis Coverage Predictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791 C/(I+N)-based Coverage Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791 Calculations on Subscriber Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 793 Monte Carlo Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 793 User Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 793 Simulations Based on User Profile Traffic Maps and Subscriber Lists . . . . . . . . . . . . . . . . . . . . . . . . . 794 Simulations Based on Sector Traffic Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 795 Simulation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 797
11.4 11.4.1 11.4.1.1 11.4.1.2 11.4.1.3
Calculation Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 799 Co- and Adjacent Channel Overlaps Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 799 Conversion From Channel Numbers to Start and End Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800 Co-Channel Overlap Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800 Adjacent Channel Overlap Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 801
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11.4.1.4 11.4.2 11.4.2.1 11.4.2.2 11.4.2.3 11.4.2.4 11.4.2.5 11.4.2.6 11.4.2.7 11.4.2.8 11.4.2.8.1 11.4.2.8.2 11.4.2.9 11.4.2.10 11.4.3 11.4.4 11.4.5 11.4.5.1 11.4.5.2 11.4.6 11.4.6.1 11.4.6.2 11.5 11.5.1 11.5.2 11.5.3 11.5.3.1 11.5.3.2 11.5.3.3 11.5.4 11.5.4.1 11.5.4.2
12
© Forsk 2015
Total Overlap Ratio Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Signal Level and Quality Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Signal Level Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Noise Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interference Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C/N Calculation (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C/(I+N) and Bearer Calculation (DL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Signal Level Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Noise Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interference Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interference Signal Levels Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Noise Rise Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C/N Calculation (UL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C/(I+N) and Bearer Calculation (UL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Best Server Determination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service Area Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation of Total Cell Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Channel Throughput, Cell Capacity, and Per-user Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scheduling and Radio Resource Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scheduling and Radio Resource Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . User Throughput Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
802 803 803 804 804 806 807 809 810 810 811 811 812 813 815 815 816 816 817 820 820 823
Automatic Planning Algorithms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Automatic Neighbour Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Automatic Inter-technology Neighbour Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Automatic Frequency Planning Using the AFP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Constraint and Relationship Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cost Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AFP Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interference Matrix Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Distance Importance Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
824 825 829 831 832 832 833 833 833 834
ACP Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 839
12.1 12.1.1 12.1.1.1 12.1.1.2 12.1.1.3 12.1.2 12.1.2.1 12.1.2.2 12.1.2.3 12.1.2.4 12.1.2.5 12.1.2.6 12.1.2.7 12.1.2.8 12.1.3
Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Quality Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Definition and Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Progressive Thresholds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Target Filtering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Quality Indicators in the ACP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSM Quality Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UMTS Quality Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CDMA2000 Quality Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LTE Quality Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . WiMAX Quality Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Quality Indicator Parameters and Reference Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Advanced Objective Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cost Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Atoll and ACP Prediction Matching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
839 839 839 840 841 841 841 841 841 842 842 842 843 843 843
12.2 12.2.1 12.2.2 12.2.2.1 12.2.2.2 12.2.2.3 12.2.2.4 12.2.3 12.2.4
Quality Predictions and the Antenna Masking Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Optimised Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Antenna Masking Modes for Non-Native Propagation Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Basic Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Improved Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Antenna Correction Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Full Path Loss Method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CrossWave Propagation Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Antenna Masking and Repeaters, Remote Antennas, and Secondary Antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
844 844 844 844 845 845 845 846 846
12.3 12.3.1 12.3.1.1 12.3.1.2 12.3.1.3
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Configuring an Optimisation Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Antenna Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Electrical Tilt (AEDT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Relative Electrical Tilt Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
846 846 846 847 847
20
AT330_TRR_E1
Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
12.4 12.4.1 12.4.2
Multi-RAT and Co-planning Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 848 Multi-RAT and Co-planning Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 848 Technology Layer Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 849
12.5 12.5.1 12.5.2 12.5.3 12.5.4 12.5.4.1 12.5.4.2 12.5.5 12.5.6 12.5.7 12.5.8 12.5.9 12.5.9.1 12.5.9.2
Optimisation Methodology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 849 Search Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 849 Tuning Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 850 Sorting Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 851 Global Score Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 851 Search Algorithm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 851 Tuning Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 852 Weighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 852 Controlling the Optimisation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 852 Implementation Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 853 Memory Usage and Optimisation Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 854 Internal Data Management and Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 854 Memory Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 854 Disk Space Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 855
12.6 12.6.1 12.6.2 12.6.2.1 12.6.2.2 12.6.2.3 12.6.2.4 12.6.2.5 12.6.2.6 12.6.3 12.6.3.1 12.6.3.2 12.6.4 12.6.4.1 12.6.4.2 12.6.5
Load Balancing Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 855 Principle Used in ACP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 855 Optimisation Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 855 Traffic Capture for Load Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 855 Cell Capacity Load Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 856 Load Balancing Score Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 856 Load Quality Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 857 Captured Traffic Ratio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 857 Introduction of Load Balancing as a Quality Indicator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 858 Quality Figures Used for Graphs and Statistics Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 858 Load Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 859 Average Load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 859 Optimisation Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 859 Load Balancing Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 859 Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 860 Impact on the Global Score Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 861
12.7 12.7.1 12.7.1.1 12.7.1.2 12.7.1.3 12.7.1.4 12.7.1.5 12.7.2 12.7.3
EMF Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 861 Concepts of ACP EMF Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 862 Propagation Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 862 Terrain Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 862 Distribution of Evaluation Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 862 The Contribution of Transmitter Power to EMF Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 863 Worst-case Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 863 General Workflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 863 EMF Exposure Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 863
12.8
Shadowing Margin and Indoor Coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 865
12.9 12.9.1 12.9.2 12.9.3 12.9.4 12.9.5 12.9.5.1 12.9.5.2 12.9.5.3 12.9.5.4 12.9.5.5 12.9.6
Multi-Storey Optimisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 865 Path Loss Calculation and Data Caching. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 865 Pixel Weighting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 865 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 865 Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 866 Concepts of ACP EMF Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 866 Propagation Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 866 Terrain Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 867 Distribution of Evaluation Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 867 The Contribution of Transmitter Power to EMF Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 867 Worst-case Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 867 General Workflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 867
12.10
ACP Software Data Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 868
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Table of Contents
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© Forsk 2015
Chapter 1 Antennas and Equipment This chapter covers the following topics: •
"Antenna Attenuation" on page 25
•
"Antenna Pattern Smoothing" on page 27
•
"Power Received From Secondary Antennas" on page 29
•
"Transmitter Radio Equipment" on page 30
•
"Repeaters and Remote Antennas" on page 32
•
"Beamforming Smart Antenna Models" on page 43
•
"Grid-of-Beams Smart Antenna Model" on page 51
•
"Adaptive Beam Smart Antenna Model" on page 52
•
"Statistical Smart Antenna Gain Model" on page 53
Atoll 3.3.0 Technical Reference Guidefor Radio Networks © Forsk 2015
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AT330_TRR_E1
1 Antennas and Equipment 1.1 Antenna Attenuation To determine the transmitter antenna attenuation, Atoll calculates the accurate azimuth and tilt angles and performs 3D interpolation of the horizontal and vertical patterns.
1.1.1 Calculation of Azimuth and Tilt Angles From the direction of the transmitter antenna and the receiver position relative to the transmitter, Atoll determines the receiver position relative to the direction of the transmitter antenna (i.e. the direction of the transmitter-receiver path in the transmitter antenna coordinate system). aTx and eTx are respectively the transmitter (Tx) antenna azimuth and tilt in the coordinate system S 0 x y z . aRx and eRx are respectively the azimuth and tilt of the receiver (Rx) in the coordinate system S 0 x y z . d is the distance between the transmitter (Tx) and the receiver (Rx).
Figure 1.1: Azimuth and Tilt Computation In the coordinate system S 0 x y z , the receiver coordinates are: x Rx
cos e Rx sin a Rx d
y Rx =
cos e Rx cos a Rx d
z Rx
(1)
– sin e Rx d
Let az and el respectively be the azimuth and tilt of the receiver in the transmitter antenna coordinate system S Tx x'' y'' z'' . These angles describe the direction of the transmitter-receiver path in the transmitter antenna coordinate system. Therefore, the receiver coordinates in S Tx x'' y'' z'' are: x'' Rx y'' Rx = z'' Rx
cos el sin az d cos el cos az d – sin el d
(2)
According to the figure above, we have the following relations: x' y' = z'
cos a Tx – sin a Tx 0
x sin a Tx cos a Tx 0 y z 0 0 1
(3)
and
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 1: Antennas and Equipment
1 0 0 x'' x' = cos – sin e 0 e y'' y' Tx Tx 0 sin e Tx cos e Tx z'' z'
©Forsk 2015
(4)
Therefore, the relation between the system S 0 x y z and the transmitter antenna system S Tx x'' y'' z'' is: 1 0 0 cos a Tx – sin a Tx 0 x'' x = 0 e cos – sin e y'' sin a Tx cos a Tx 0 y Tx Tx z'' z 0 sin e Tx cos e Tx 0 0 1
(5)
We get, x'' y'' = z''
cos a Tx – sin a Tx 0 x cos e Tx sin a Tx cos e Tx cos a Tx – sin e Tx y z sin e Tx sin a Tx sin e Tx cos a Tx cos e Tx
(6)
Then, substituting the receiver coordinates in the system S0 from Eq. (1) and the receiver coordinates in the system STx from Eq. (2) in Eq. (6) leads to a system where two solutions are possible: 1st solution: If a Rx = a Tx , then az = 0 and el = eRx – e Tx 2nd solution: If a Rx a Tx , then 1 az = atan ---------------------------------------------------------------------------------------cos e Tx sin e Tx tan e Rx ----------------------------------- + ---------------------------------------------tan a Rx – a Tx sin a Rx – a Tx and cos e Tx tan e Rx – sin e Tx el = atan sin az ---------------------------------- + ---------------------------------------------- sin a Rx – a Tx tan a Rx – a Tx If sin az sin a Rx – a Tx 0 , then az = az + 180
1.1.2 Antenna Pattern 3D Interpolation The direction of transmitter-receiver path in the transmitter antenna coordinate system is given by angle values az and el. Atoll considers these values to determine transmitter antenna attenuations in horizontal and vertical patterns. It reads the following: • •
H(az) H(a0) V(el)
the attenuation in the horizontal pattern for the calculated azimuth angle az the attenuation in the horizontal pattern for the electrical azimuth angle a0 the attenuation V(el) in the vertical pattern for the calculated tilt angle el
Then it calculates the antenna total attenuation, L antTx az el : 180 – az – a 0 az – a 0 - H a 0 – V el + ------------------- H 180 + a 0 – V 180 – el if |el| ≠ 90° L antTx az el = H az – ---------------------------------180 180 Else: L antTx az el = V(el) Atoll assumes that the horizontal and vertical patterns are cross-sections of a 3D pattern. In other words, the description of the antenna pattern must satisfy the following: H(0)=V(0)
and
H()=V()
If the electrical tilt is e0, the horizontal pattern is a conical section with an elevation of e0 degrees off the horizontal plane. If the electrical azimuth is a0, the vertical pattern is a plane section with a rotation a0 degrees from the vertical plane. In this case, the description of the antenna pattern must satisfy the following conditions: H(a0)=V(e0)
26
and
H(180+a0)=V(180-e0)
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AT330_TRR_E1
If the constraints listed above are satisfied, this implies that: • •
Interpolated horizontal and vertical patterns respectively fit in with the entered horizontal and vertical patterns, even in case of electrical tilt, and The contribution of both front and back parts of the vertical pattern are taken into account.
Otherwise, only the second point is guaranteed. • • •
This interpolation is performed in dBs. Angle values in formulas are stated in degrees. This interpolation is not used with 3D antenna patterns.
1.1.3 Additional Electrical Downtilt Modelling The additional electrical downtilt, AEDT, also referred to as remote electrical downtilt or REDT, introduces a conical transformation of the 3D antenna pattern in the vertical axis. In order to take it into account, the vertical pattern is transformed as follows: V x = V x – AEDT when x [– 90,90] V x = V x + AEDT when x [90,270] Where, the angle values are in degrees. The vertical pattern transformation is represented below. The left picture shows the initial vertical pattern when there is no electrical downtilt and the right one shows the vertical pattern transformation due to an electrical downtilt of 10°. Then, Atoll proceeds as explained in the previous section. It determines the antenna attenuation in the transformed vertical pattern for the calculated tilt angle (V(el)) and applies the 3D interpolation formula in order to calculate the antenna total attenuation, L antTx az el .
Figure 1.2: Vertical Pattern Transformation due to Electrical Downtilt
1.2 Antenna Pattern Smoothing Empirical propagation models, like the Standard Propagation Model (SPM), require antenna pattern smoothing in the vertical plane to simulate the effects of reflections and diffractions. Signal level predictions can be improved by smoothing the highattenuation points of the vertical pattern. You can smooth vertical as well as horizontal antenna patterns in Atoll. The antenna pattern smoothing algorithm in Atoll first determines the peaks and nulls in the pattern within the smoothing angle (ASmoothing) defined by the user. Peaks (P) are the lowest attenuation angles and nulls (N) are the highest attenuation angles in the pattern. Then, it determines the nulls to be smoothed (NSmoothing) and their corresponding angles according to the defined Peak-to-Null Deviation (DPeak-to-Null). DPeak-to-Null is the minimum difference of attenuation in dBs between two peaks and a null between them. Finally, Atoll smoothes the pattern between 0 and the smoothing angle (ASmoothing) by applying the smoothing factor (FSmoothing) defined by the user. Let’s take an example of an antenna pattern to be smoothed, as shown in Figure 1.3 on page 28. Let DPeak-to-Null be 10 dB, ASmoothing = 90 degrees, and FSmoothing = 0.5.
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Figure 1.3: Vertical Antenna Pattern Atoll first determines the peaks and nulls in the part of the pattern to be smoothed by verifying the slopes of the pattern curve at each angle.
Figure 1.4: Peaks and Nulls in the Antenna Pattern Peaks (P) and Nulls (N) Angle (°)
Attenuation (dB)
1
0.1
15
33.5
21
13.2
30
37.6
38
16.9
49
32.2
67
15.6
Then, Atoll verifies whether the difference of attenuation at a given angle is DPeak-to-Null less than the before and after it. This comparison determines the nulls to be smoothed (NSmoothing). Nulls to be smoothed (NSmoothing)
28
Angle (°)
Attenuation (dB)
15
33.5
30
37.6
49
32.2
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Once the nulls are known, Atoll applies the smoothing algorithm to all the attenuation values at all the angles between the first peak, the null, and the last peak. Smoothing Algorithm For all nulls n N Smoothing surrounded by two peaks P1 and P2 at angles 1 and 2 , A 2 – A 1 - i – 1 A i Smoothed = A i – F Smoothing A i – A + ---------------------1 2 – 1 Where, i is the angle in degrees from 1 to 2 incremented by 1 degree, AAngle is the attenuation at any given angle which can be i, 1 or 2 , and FSmoothing is the smoothing factor defined by the user.
1.3 Power Received From Secondary Antennas When secondary antennas are installed on a transmitter, the signal level received from it is calculated as follows: G ant – m Tx G ant – i X i ---------------------Tx P Tx 1 – P Tx X i -------------------- L Tx L Tx i ------------------------------------------------------------------ + ---------------------------------------- L ant – m az m el m L ant – i az i el i Tx Tx i = -------------------------------------------------------------------------------------------------------------------------------- (not in dB1) L model
P rec
Where, PTx is the transmitter power (Ppilot in UMTS HSPA and CDMA2000, PP-CCPCH in TD-SCDMA, PPreamble in WiMAX, and PDLRS in LTE), i is the secondary antenna index, xi is the percentage of power dedicated to the secondary antenna, i, G ant – m
Tx
is the gain of the main antenna installed on the transmitter,
LTx are transmitter losses (LTx=Ltotal-DL), G ant – i
Tx
is the gain of the secondary antenna, i, installed on the transmitter,
Lmodel is the path loss calculated by the propagation model, L ant – m az m el m is the attenuation due to main antenna pattern, Tx
L ant – i az i el i is the attenuation due to pattern of the secondary antenna, i. Tx
The definition of angles, az and el, depends on the used calculation method. •
•
1.
Method 1 (must be indicated in an Atoll.ini file): • azm: the difference between the receiver antenna azimuth and azimuth of the transmitter main antenna, • elm: the difference between the receiver antenna tilt and tilt of the transmitter main antenna, • azi : the difference between the receiver antenna azimuth and azimuth of the transmitter secondary antenna, i, • eli : the difference between the receiver antenna tilt and tilt of the transmitter secondary antenna, i, Method 2 (default): • azm : the receiver azimuth in the coordinate system of the transmitter main antenna, • elm : the receiver tilt in the coordinate system of the transmitter main antenna, • azi : the receiver azimuth in the coordinate system of the transmitter secondary antenna, i, • eli : the receiver tilt in the coordinate system of the transmitter secondary antenna, i.
Formula cannot be directly calculated from components stated in dB and must be converted in linear values.
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©Forsk 2015
1.4 Transmitter Radio Equipment Radio equipment such as TMA, feeder and BTS, are taken into account to evaluate: •
Total UL and DL losses of transmitter ( L total – UL L total – DL ) and transmitter noise figure NF Tx in UMTS HSPA,
•
CDMA2000 1xRTT 1xEV-DO, TD-SCDMA, WiMAX, and LTE documents, Transmitter total losses L Total in GSM GPRS EGPRS documents.
In Atoll, the transmitter-equipment pair is modelled a single entity. The entry to the BTS is considered the reference point which is the location of the transmission/reception parameters.
Figure 1.5: Reference Point - Location of the Transmission/Reception parameters •
According to the book “Radio network planning and optimisation for UMTS” by Laiho J., Wacker A., Novosad T., the noise figure corresponds to the loss in case of passive components. Therefore, feeder noise figure is equal to the cable uplink losses. UL
NF Feeder = L Feeder •
Loss and gain inputs specified in ATL documents must be positive values.
1.4.1 GSM Documents Atoll calculates DL total losses as follows: DL
DL
DL
DL
L Total – DL = L TMA + L Feeder + L Misc + L BTS – Conf Where, DL
•
L TMA is the TMA transmission loss.
•
L Feeder is the feeder transmission loss ( L Feeder = L Feeder I Feeder + L Connector , where L Feeder , I Feeder and L Connector
DL
DL
DL
DL
DL
DL
are respectively the feeder loss per metre, the transmission feeder length in metre and the connector transmission loss). DL
•
L Misc are the miscellaneous transmission losses.
•
L BTS – Conf are the losses due to BTS configuration (BTS property).
DL
1.4.2 UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE Documents As the reference point is the BTS entry, the transmitter noise figure corresponds to the BTS noise figure. Therefore, we have NF TX = NF BTS . Where NF BTS is the BTS noise figure. Uplink Total Losses Atoll calculates total UL losses as follows: UL
UL
UL
UL
L Total – UL = L Misc + L Feeder + L BTS – Conf + NR Repeaters – G Ant – div – G TMA Where, •
30
UL
L Misc are the miscellaneous reception losses (Transmitter property).
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AT330_TRR_E1
•
UL
UL
UL
UL
UL
L Feeder are the feeder reception losses ( L Feeder = L Feeder I Feeder + L Connector , where L Feeder , I Feeder and UL
L Connector are respectively the feeder loss per metre (Feeder property), the reception feeder length in metre (Transmitter property) and the connector reception losses. UL
•
L BTS – Conf are the losses due to BTS configuration (BTS property).
•
G Ant – div is the antenna diversity gain (Transmitter property). This gain does not exist in WiMAX and LTE documents.
•
NR Repeaters is the noise rise at transmitter due to repeaters. This parameter is taken into account only if the
UL
transmitter has active repeater(s). The noise rise at transmitter due to repeaters is calculated as follows: NR Repeaters = 10 Log 1 +
1
------------------ NIM Rp r
r
For each active repeater ( k ), Atoll calculates a noise injection margin ( NIM Rp ). This is the difference between the k
donor transmitter noise figure ( NF TX ) and the repeater noise figure received at the donor. Rp k
NIM Rp = NF TX – NF Rp + G amp – L r k
TX – Rp k
Where, •
NF Rp is the repeater noise figure, k
Rp k
•
G amp is the repeater amplification gain (repeater property),
•
L
•
For each active repeater ( k ), Atoll converts the noise injection margin ( NIM Rp ) to Watt. Then, it uses the values
TX – R p k
are the losses between the donor transmitter and the repeater (repeater property). k
to calculate the noise rise at the donor transmitter due to active repeaters ( NR Repeaters ). •
G TMA is the gain due to TMA, which is calculated as follows: WithoutTMA
G TMA = NF Composite WithTMA
WithTMA
– NF Composite WithoutTMA
Where NF Composite and NF Composite
are the composite noise figures with and without TMA respectively.
Friis' equation is used to calculate the composite noise figure when there is a TMA.
WithTMA
NF Composite
NF Feeder NF BTS NF -----------------------------------------TMA ------------------ 10 10 10 10 – 1 10 – 1 + ---------------------------------- + ----------------------------------------------- = 10 Log 10 UL UL UL G TMA G TMA G Feeder ---------------------------------------------------- 10 10 10 10 10 10
WithoutTMA
And, NF Composite
= NF BTS + NF Feeder
Where, •
NF Feeder is the feeder noise figure.
•
NF TMA is the TMA noise figure.
•
NF BTS is the BTS noise figure.
•
G TMA is the TMA reception gain.
•
G Feeder is the feeder UL gain G Feeder = – L Feeder .
•
L Feeder is the feeder reception loss ( L Feeder = L Feeder I Feeder + L Connector , where L Feeder , I Feeder and
UL UL
UL
UL
UL
UL
UL
UL
UL
UL
L Connector are respectively the feeder loss per metre, the reception feeder length in metre and the connector reception loss). Downlink Total Losses Atoll calculates total DL losses as follows.
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 1: Antennas and Equipment DL
DL
DL
©Forsk 2015 DL
L Total – DL = L TMA + L Feeder + L Misc + L BTS – Conf Where, DL
•
L TMA is the TMA transmission loss.
•
L Feeder is the feeder transmission loss ( L Feeder = L Feeder I Feeder + L Connector , where L Feeder , I Feeder and L Connector
DL
DL
DL
DL
DL
DL
are respectively the feeder loss per metre, the transmission feeder length in metre and the connector transmission losses). DL
•
L Misc are the miscellaneous transmission losses.
•
L BTS – Conf are the losses due to BTS configuration (BTS property).
DL
1.5 Repeaters and Remote Antennas A repeater receives, amplifies, and re-transmits the radiated or conducted RF carrier both in downlink and uplink. It has a donor side and a server side. The donor side receives the signal from a donor (transmitter, repeater, or remote antenna), and the server side amplifies and re-transmits the received signal. Repeaters increase the coverage area of their donors by retransmitting all the frequencies (TRXs in GSM, carriers in UMTS, CDMA2000 and TD-SCDMA, and channels in WiMAX and LTE documents). Donors and repeaters may be linked through: • • •
Air: Microwave Links: Optical Fibre Links:
User-defined or calculated propagation losses User-defined link losses User-defined link losses
Remote antennas are antennas located far from the transmitters, at locations that would normally require long runs of feeder cable. A remote antenna is connected to the base station with an optic fibre. Remote antennas allow you to ensure radio coverage in an area without a new base station. In Atoll, remote antennas should be connected to base stations that do not have any antennas. A remote antenna, as opposed to a repeater, does not have any equipment and therefore generates neither amplification gain nor noise. In UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE documents, Atoll calculates the signal level received from a repeater or a remote antenna by determining the total downlink and uplink gains (described in "UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE Documents" on page 32). In GSM documents, the received signal level from a repeater or a remote antenna is calculated by determining the EIRP transmitted by the repeater or remote antenna (described in "GSM Documents" on page 39). The following sections describe how received signal levels, and the related downlink and uplink gains and EIRP, are calculated from a repeater or remote antenna R with a donor D.
1.5.1 UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE Documents 1.5.1.1 Signal Level Calculation The received signal level (dBm) on a carrier ic from a donor D at a pixel/mobile Mi via a repeater or remote antenna R (see Figure 1.6 on page 34) is calculated as follows: R
D
R – Mi
R
C DL ic = P DL ic + G Total – L Path – M Shadowing – L Indoor + G
Mi
–L
Mi
Mi
Mi
R
– L Ant – L Body – L Misc – DL
If a pixel/mobile Mi receives signals from the donor D and its repeater R, the total signal D
R
strength is the sum of the two signals: C DL ic + C DL ic The received signal level (dBm) from a pixel/mobile Mi at a donor D via a repeater or remote antenna R (see Figure 1.6 on page 34) is calculated as follows: Mi
Mi
R
R – Mi
C UL = P UL + G Total – L Path – M Shadowing – L Indoor + G
Mi
–L
Mi
Mi
Mi
Here:
32
D
•
P DL ic is the downlink transmission power of a donor D on carrier ic.
•
P UL is the uplink transmission power of a pixel/mobile Mi.
Mi
R
– L Ant – L Body – L Misc – UL
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AT330_TRR_E1 R
•
G Total is the total gain, user-defined or calculated as explained in "Total Gain Calculation" on page 34.
•
L Path is the path loss (dB) calculated as follows:
R–M
R–M
i
i
R
L Path = L Model + L Ant , with: •
L Model is the path loss calculated using a propagation model.
•
L Ant : Antenna attenuation (from antenna patterns) calculated for the antenna used by the repeater or remote
R
•
antenna R. M Shadowing is the shadowing margin.
•
L Indoor is the indoor loss.
•
G
• •
L
Mi
Mi
is the terminal antenna gain for the pixel/mobile Mi. is the terminal loss for the pixel/mobile Mi.
Mi
L Ant is the terminal antenna attenuation (from antenna patterns) calculated for the pixel/mobile Mi (available in WiMAX and LTE only).
Mi
For calculating the useful signal level from the best serving cell, L Ant is determined in the direction (H,V) = (0,0) from the antenna patterns of the antenna used by Mi. For Mi
calculating the interfering signal level from any interferer, L Ant is determined in the direction of the interfering cell from the antenna patterns of the antenna used by Mi, while the antenna is pointed towards Mi’s best serving cell.
•
Mi
L Body is the body loss defined for the service used by the pixel/mobile Mi.
L
Mi
,G
Mi
Mi
Mi
, L Ant , and L Body are not used in all the calculations. For more information, see
the technology-specific chapters. R
•
L Misc – DL is the miscellaneous transmission losses defined for the repeater or remote antenna R.
•
L Misc – UL is the miscellaneous reception losses defined for the repeater or remote antenna R.
R
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Figure 1.6: UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE: Signal Level Calculation
1.5.1.2 Total Gain Calculation The total gain is calculated from the donor transmitter reference point ( ) to the repeater or remote antenna reference point ( ) as follows: Over-the-Air Repeaters D
D
D–R
R
R
R G Total = – L Total – DL + G Ant – L Model + G Donor – Ant – LDonor
RX – Feeder
R
R
+ G Amp – LCov
TX – Feeder
R
+ G Cov – Ant
Figure 1.7: Downlink Total Gain: Over-the-Air Repeaters
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Here: D
•
L Total – DL are the total downlink losses of the donor D.
•
G Ant is the gain of the antenna used at the donor D.
•
L Model is the path loss between the donor D and the repeater or remote antenna R. This can be user-defined or
D
D–R
calculated using the selected propagation model. If you do not select a propagation model, the propagation losses between the donor and the repeater or remote antenna are calculated using the ITU 526-5 propagation model. R
•
G Donor – Ant is the gain of the donor-side antenna used at the repeater or remote antenna R.
•
LDonor
R
are the donor-side reception feeder losses for the repeater or remote antenna R.
RX – Feeder R
•
G Amp is the amplifier gain of the repeater R. For remote antennas, this is 0.
•
LCov
R
are the coverage-side transmission feeder losses for the repeater or remote antenna R.
TX – Feeder
•
R
G Cov – Ant is the gain of the coverage-side antenna used at the repeater or remote antenna R.
Secondary antennas are fully supported in the evaluation of the repeater gains.
Microwave Link Repeaters D–R
R
R
R
R G Total = – L MW + G Amp – LCov
TX – Feeder
+ G Cov – Ant
Figure 1.8: Downlink Total Gain: Microwave Link Repeaters Here: D–R
•
L MW are the user-defined microwave link losses between the donor D and the repeater or remote antenna R.
•
G Amp is the amplifier gain of the repeater R. For remote antennas, this is 0.
•
LCov
R
R
are the coverage-side transmission feeder losses for the repeater or remote antenna R.
TX – Feeder
•
R
G Cov – Ant is the gain of the coverage-side antenna used at the repeater or remote antenna R.
Optical Fibre Link Repeaters and Remote Antennas D–R
R
R
R G Total = – L Fibre + G Amp – LCov
TX – Feeder
R
+ G Cov – Ant
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Figure 1.9: Downlink Total Gain: Optical Fibre Link Repeaters or Remote Antennas Here: D–R
•
L Fibre are the user-defined optical fibre link losses between the donor D and the repeater or remote antenna R.
•
G Amp is the amplifier gain of the repeater R. For remote antennas, this is 0.
•
LCov
R
R
are the coverage-side transmission feeder losses for the repeater or remote antenna R.
TX – Feeder
•
R
G Cov – Ant is the gain of the coverage-side antenna used at the repeater or remote antenna R.
Repeater Downlink Power Limitation Atoll verifies that the downlink power after amplification is consistent with the repeater equipment limitation. D
R
R
R
R
P DL ic + G Total P Max + G Cov – Ant – LCov
TX – Feeder
Here: •
D
P DL ic is the downlink transmission power of a donor D on carrier ic. When the donor has more than one cell, Atoll considers the highest power. R
•
G Total is the total downlink gain, user-defined or calculated as explained in "Total Gain Calculation" on page 34.
•
P Max is the maximum downlink power allowed by the equipment.
•
LCov
R
R
are the coverage-side transmission feeder losses for the repeater or remote antenna R.
TX – Feeder
•
R
G Cov – Ant is the gain of the coverage-side antenna used at the repeater or remote antenna R.
1.5.1.3 Repeater Noise Figure You can define and assign a repeater equipment to each repeater. In addition to the allowed ranges of gains and powers allowed to each repeater, these equipment contain a noise figure which is applied to the repeater they are assigned to. This noise figure has an impact on the donor total reception losses. For information, see "Transmitter Radio Equipment" on page 30.
1.5.1.4 Appendix: Carrier Power and Interference Calculation This section explains how Atoll calculates the received carrier power and interference when a transmitter has a connected repeater. A mobile receiver receives signal from the donor transmitter as well as its repeater. Similarly, the signal from the mobile is received at the donor transmitter as well as its repeater. In practice, when a mobile receiver is in the vicinity of the donor transmitter, the signal to/from the repeater would be very weak due to high pathloss between the repeater and the mobile receiver. Similarly, when the mobile receiver is located in the vicinity of the repeater, the signal to/from the donor transmitter would be very weak due to the same reason. Atoll does not differentiate between the mobile receiver being in the transmitter coverage area or being in its repeater coverage area. Atoll adds the signals received from the donor transmitter and its repeater to generate a combined pathloss matrix that is associated with the donor transmitter and includes the effect of its repeater.
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Calculation of Total Path Loss The total pathloss, L Total , is calculated by computing a downlink budget. If we take the case of a CDMA project, without considering any shadowing margin or indoor loss, the power received from the donor transmitter, Txd on a carrier ic, at the mobile receiver can be stated as (for a link over the air): D
D
P Pilot ic G Ant D P Rec ic = ------------------------------------------D D – Mi L Total –DL L Path Where, D
P Rec ic is the carrier power received at the receiver from the donor transmitter on a carrier ic (in W) D
P Pilot ic is the pilot power of the donor transmitter on the carrier ic (in W) D
G Ant is the donor transmitter antenna gain. D
L Total – DL is the transmission feeder loss of the donor transmitter. D – Mi
L Path is the path loss between the donor transmitter and the mobile receiver. Similarly, the power received at the mobile receiver from the repeater R is: D
R
P Pilot ic G Total R P Rec ic = -------------------------------------------R – Mi L Path Where, R
P Rec ic is the carrier power received at the mobile receiver from the repeater on a carrier ic (in W) D
P Pilot ic is the pilot power of the donor transmitter on the carrier ic (in W) R
G Total is the total gain of repeater linked to a donor transmitter with an air link. R – Mi
L Path is the path loss between the repeater and the mobile receiver So, the total carrier power received at the mobile receiver is: D R G Ant G Total D–R R R D P Rec ic = P Rec ic + P Rec ic = P Pilot ic --------------------------------------------- - + ------------– Mi R – Mi L DTotal – DL L DPath L Path
Since, D
D
P Pilot ic G Ant L Total = -----------------------------------------------D–R D L Total – DL P Rec ic Therefore, D
D
P Pilot ic G Ant L Total = ----------------------------------------------------------------------------------------------------------------------------D R G Ant G Total D D L Total – DL P Pilot ic ---------------------------------------------- + -------------- – Mi R – Mi L DTotal – DL L DPath L Path Hence, D
G Ant L Total = --------------------------------------------------------------------------------------------------D R G Total G Ant D - + ------------L Total – DL --------------------------------------------- – Mi R – Mi L DTotal – DL L DPath L Path This total path loss depends on the location of the mobile receiver in realistic network scenarios. As a mobile in the donor transmitter/repeater coverage area is likely to be far from the repeater/donor transmitter coverage area, the respective pathloss value will be very large. This implies that we can study the two cases separately without influencing the results much. •
Case 1: Receiver in Donor Transmitter Coverage Area
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G Total R – Mi - can be ignored. This implies that: L Path is likely to be very high, so the term ------------R – Mi L Path D – Mi
L Total = L Path
Considering this total pathloss value, the total received power in the uplink and in the downlink can be stated as: D
D
D
D
P Pilot ic G Ant P Pilot ic G Ant D P Rec – DL ic = ------------------------------------------- = --------------------------------------------D D D – Mi L Total – DL L Total L Total – DL L Path Mi
D
Mi
D
P Output ic G Ant P Output ic G Ant D - = ---------------------------------------------P Rec – UL ic = ---------------------------------------------D D D – Mi L Total – UL L Total L Total – UL L Path Where, Mi
P Output ic is the transmitted power from the mobile terminal on the carrier ic (in W) D
L Total – UL is the reception feeder loss of the transmitter •
Case 2: Receiver in Repeater Coverage Area D
G Ant D – Mi - can be ignored. This implies that: L Path is likely to be very high, so the term --------------------------------------------D D – Mi L Total – DL L Path D
D
G Ant G Ant L Total = --------------------------------------------------- = ---------------------------------------R R R G Total L Total – DL D G Total ----------------------------------------- L Total – DL ------------R – Mi – Mi L RPath L Path D
D
D
R
P Pilot ic G Ant P Pilot ic G Total D - = -------------------------------------------P Rec – DL ic = ------------------------------------------D R – Mi L Total – DL L Total L Path Mi
R
D
Mi D P Output ic G Total L Total – DL P Output ic G Ant D - ---------------------P Rec – UL = ---------------------------------------------- = ------------------------------------------------R – Mi D D L Path L Total – UL L Total – UL L Total
Where, Mi
P Output ic is the transmitted power from the mobile terminal (in W) D
L Total – UL is the reception feeder loss of the transmitter Calculation of Eb/Nt Uplink In the uplink, the quality level at the transmitter on a traffic channel is: E b C W ---= --- ---- N t UL I R Where, C is the carrier power received from the mobile terminal (in W) I is the total interference (in W) W is the spreading bandwidth (Hz) R is the effective service throughput in the uplink (bits/s) (W/R is the service processing gain in the uplink) C and I are both evaluated at the same reference point, which is the entry of BTS using the following formulas. Mi
D
P Output G Ant C = P Total – UL = --------------------------------------D L Total – UL L Total I = I Total + N 0
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Where, I Total is the sum of the signals received from mobile terminals inside the same cell and those outside (in W) N 0 is the transmitter equipment thermal noise (in W) Therefore, for each mobile terminal Mi,
I Total =
Mi
Mi
D
P Output G Ant -------------------------------------- L DTotal – UL L Mi Total
And, D
N 0 = NF K T W Where, D
NF is the noise figure of the transmitter equipment at the reference point, i.e. the entry of the BTS K is Boltzman constant T is the ambient temperature (in K) Hence N 0 = NF
BTS
KTW
1.5.2 GSM Documents 1.5.2.1 Signal Level Calculation The received signal level (dBm) on a TRX type tt from a donor D at a pixel/mobile Mi via a repeater or remote antenna R (see Figure 1.10 on page 40) is calculated as follows: R
R – Mi
R
C DL tt = EIRP DL tt – P tt – L Path – M Shadowing – L Indoor + G
Mi
–L
Mi
R
– L Misc – DL
If a pixel/mobile Mi receives signals from the donor D and its repeater R, the total signal D
R
strength is the sum of the two signals: C DL tt + C DL tt Here: R
•
EIRP DL tt is the effective isotropic radiated power of the repeater or remote antenna R on the TRX type tt. It can be
• •
user-defined or calculated as explained in "EIRP Calculation" on page 40. the downlink transmission power of a donor D on carrier ic. P tt is the power offset defined for the TRX type tt.
•
L Path is the path loss (dB) calculated as follows:
R – Mi R – Mi
R
L Path = L Model + L Ant , with: •
L Model is the path loss calculated using a propagation model.
•
L Ant : Antenna attenuation (from antenna patterns) calculated for the antenna used by the repeater or remote
R
•
antenna R. M Shadowing is the shadowing margin.
•
L Indoor is the indoor loss.
•
G
Mi
Mi
is the terminal antenna gain for the pixel/mobile Mi.
•
L
•
R L Misc – DL
is the terminal loss for the pixel/mobile Mi. is the miscellaneous transmission losses defined for the repeater or remote antenna R.
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s Figure 1.10: GSM: Signal Level Calculation
1.5.2.2 EIRP Calculation D
The EIRP of a repeater or remote antenna R is calculated at the repeater or remote antenna reference point ( ) w. r. t. P DL at the donor reference point ( ) as follows: Over-the-Air Repeaters R
D
D
D
D–R
R
R
EIRP DL tt = P DL – L Total – DL + G Ant – L Model + G Donor – Ant – LDonor
RX – Feeder
R
Figure 1.11: EIRP: Over-the-Air Repeaters Here:
40
D
•
P DL is the downlink transmission power of the donor D.
•
L Total – DL are the total downlink losses of the donor D.
D
R
+ G Amp – LCov
TX – Feeder
R
+ G Cov – Ant
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 1: Antennas and Equipment
AT330_TRR_E1 D
•
G Ant is the gain of the antenna used at the donor D.
•
L Model is the path loss between the donor D and the repeater or remote antenna R. This can be user-defined or
D–R
calculated using the selected propagation model. If you do not select a propagation model, the propagation losses between the donor and the repeater or remote antenna are calculated using the ITU 526-5 propagation model. R
•
G Donor – Ant is the gain of the donor-side antenna used at the repeater or remote antenna R.
•
LDonor
R
are the donor-side reception feeder losses for the repeater or remote antenna R.
RX – Feeder R
•
G Amp is the amplifier gain of the repeater R. For remote antennas, this is 0.
•
LCov
R
are the coverage-side transmission feeder losses for the repeater or remote antenna R.
TX – Feeder
•
R
G Cov – Ant is the gain of the coverage-side antenna used at the repeater or remote antenna R.
Secondary antennas are fully supported in the evaluation of the repeater gains.
Microwave Link Repeaters D
D–R
R
R
R EIRP DL tt = P DL – L MW + G Amp – LCov
TX – Feeder
R
+ G Cov – Ant
Figure 1.12: Downlink Total Gain: Microwave Link Repeaters Here: D
•
P DL is the downlink transmission power of the donor D.
•
L MW are the user-defined microwave link losses between the donor D and the repeater or remote antenna R.
•
G Amp is the amplifier gain of the repeater R. For remote antennas, this is 0.
•
LCov
D–R R
R
are the coverage-side transmission feeder losses for the repeater or remote antenna R.
TX – Feeder
•
R
G Cov – Ant is the gain of the coverage-side antenna used at the repeater or remote antenna R.
Optical Fibre Link Repeaters and Remote Antennas D
D–R
R
R
R EIRP DL tt = P DL – L Fibre + G Amp – LCov
TX – Feeder
R
+ G Cov – Ant
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Figure 1.13: Downlink Total Gain: Optical Fibre Link Repeaters or Remote Antennas Here: D
•
P DL is the downlink transmission power of the donor D.
•
L Fibre are the user-defined optical fibre link losses between the donor D and the repeater or remote antenna R.
•
G Amp is the amplifier gain of the repeater R. For remote antennas, this is 0.
•
LCov
D–R R
R
are the coverage-side transmission feeder losses for the repeater or remote antenna R.
TX – Feeder R
•
G Cov – Ant is the gain of the coverage-side antenna used at the repeater or remote antenna R.
Repeater Downlink Power Limitation Atoll verifies that the EIRP after amplification is consistent with the repeater equipment limitation. R
R
R
R
EIRP DL tt P Max + G Cov – Ant – LCov
TX – Feeder
Here: R
•
EIRP DL tt is the effective isotropic radiated power of the repeater R on the TRX type tt.
•
P Max is the maximum downlink power allowed by the equipment.
•
LCov
R
R
are the coverage-side transmission feeder losses for the repeater or remote antenna R.
TX – Feeder
•
R
G Cov – Ant is the gain of the coverage-side antenna used at the repeater or remote antenna R.
1.5.3 Donor-side Parameter Calculations 1.5.3.1 Azimuth This is the angle at which the donor antenna is situated with respect to the North at the repeater or remote antenna. This angle is measured clock-wise as shown in the figure below. It is the absolute horizontal angle at which the donor-side antenna of the repeater should be pointed in order to be aligned with the donor antenna.
Figure 1.14: Angle from North (Azimuth)
1.5.3.2 Mechanical Downtilt This is the tilt angle for the repeater’s donor-side antenna, which ensures that it points towards the donor antenna in the vertical plane. As a general rule, downtilt angles are considered positive and uptilt angles negative.
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Figure 1.15: Positive/Negative Mechanical Downtilt Since this parameter depends on the difference of heights/altitudes between the donor transmitter and the repeater, it can be automatically calculated in the repeater’s Donor side properties. If the height/altitude of the antenna is modified, the corresponding tilt angle can be found out and applied using the Calculate button. Example
Figure 1.16: Tilt Angle Computation The tilt angle repeater’s donor-side antenna in the above figure would be: R
D
H Donor – Ant – H Ant R - T Donor – Ant = atan ------------------------------------------D–R D As obvious, this angle will be negative for uptilts and positive for downtilts of the antenna. Here: R
•
H Donor – Ant is the height of the donor-side antenna of the repeater or remote antenna R.
•
H Ant is the height of the antenna of the donor D.
•
D
D
D–R
is the distance between the antenna of the donor D and the antenna of the repeater or remote antenna R.
1.6 Beamforming Smart Antenna Models Adaptive antenna systems use more than one antenna elements, along with smart signal processing, to locate and track various types of signals, to dynamically minimize interference, and maximize useful signal reception. The signal processor dynamically applies weights to each element of the adaptive antenna system to create array patterns in real-time. Beamforming smart antennas dynamically create antenna patterns with a main beam pointed in the direction of the user being served, i.e., the useful signal. Adaptive algorithms can also be used in order to minimize the interference received by the cells. These algorithms are based on optimization methods such as the minimum mean square error method. The following beamforming smart antenna models are available in Atoll. These smart antenna models support linear adaptive array systems, such as the one shown in Figure 1.17 on page 44. •
Optimum Beamformer: The Optimum Beamformer smart antenna model performs dynamic beamforming in downlink as explained in "Downlink Beamforming" on page 46, and beamforming and interference cancellation in uplink using the minimum mean square error algorithm as explained in "Uplink Beamforming and Interference Cancellation (MMSE)" on page 49. Smart antenna results are later on used in coverage prediction calculations.
•
Conventional Beamformer: The Conventional Beamformer smart antenna model performs dynamic beamforming in downlink and uplink as explained in "Downlink Beamforming" on page 46 and "Uplink Beamforming" on page 48, respectively. Smart antenna results are later on used in coverage prediction calculations.
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Figure 1.17: Linear Adaptive Antenna Array In the following explanations, we assume: •
There are a total of E SA elements in the adaptive antenna system.
•
is the angle of arrival for the useful signal.
• •
is the angle at which we want to calculate the smart antenna gain. d is the distance between two adjacent antenna elements.
1.6.1 Definitions and Formulas The tables in the following subsections list the parameters and formulas used in beamforming smart antenna models.
1.6.1.1 Definitions Name
Value
Unit
Description
E SA
Smart antenna model parameter
None
Number of smart antenna elements
Calculation parameter
Degrees
Angle of arrival for the useful signal
Calculation parameter
Degrees
Angle at which the smart antenna effect is calculated
d
--- , where is the wavelength of the signal 2
m
Distance between two adjacent antenna elements
1.6.1.2 Downlink Beamforming Name
Value
Unit
Description
gn
Smart antenna model parameter
None
Gain of a single element
None
Steering vector for the direction of
None
Complex smart antenna weight
None
Array correlation matrix for a given user direction
None
Smart antenna gain in any direction
S
1 e
2 j ------ d sin
e
... e
e
wn e
44
2 j ------ 2d sin
T 2 j ------ E SA – 1 d sin
2 – j ------ nd sin
– j n sin
with d = --2 H
R
S S
G SA
g n S R S = g n S S S S = g n E SA
H
H
H
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Name
Value
Unit
Description
None
Downlink array correlation matrix for iteration k
None
Average downlink array correlation matrix over a simulation (K iterations)
J
pj Rj
Rk
j=1 K
--1- K
R Avg
Rk
k=1
1.6.1.3 Uplink Beamforming Name
Value
Unit
Description
w
S ----------E SA
None
Vector of ESA complex weights for the conventional beamformer
None
Total noise correlation matrix
None
Thermal noise correlation matrix
None
Interference correlation matrix
J
RN
Rn + RI =
2 n
I+
pj Sj Sj
H
j=1 2
n I
Rn J
pj Sj Sj
RI
H
j=1 H
PN
w RN w
W
Total uplink noise power
P
p w S S w = p E SA
H
W
Total power received from the served user
CINR UL
P p E SA ------ = -------------------------H PN w RN w
None
C/(I+N) in the uplink (WiMAX)
Q UL
P p E SA ------ = -------------------------H PN w RN w
None
Signal quality in the uplink (TD-SCDMA)
G SA
E SA
None
Uplink smart antenna beamforming gain in the direction of the served user
W
Average noise correlation matrix
W
Uplink interference
None
Angular distribution of uplink noise rise
SA
H
K
RN
--1- K
Avg
RN k k=1
I UL
H
w RN
2
Avg
w – n 2
NR UL
I UL + n --------------------------2 n
1.6.1.4 Uplink Beamforming and Interference Cancellation (MMSE) Name
Value
Unit
Description
ˆ w
RN S
None
Vector of ESA complex weights for the optimum beamformer
E SA ----------------------------H –1 S RN S
None
MMSE optimization constant
–1
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Name
Value
Unit
Description
None
Total noise correlation matrix
None
Thermal noise correlation matrix
None
Interference correlation matrix
W
Total uplink noise power (optimum beamformer)
W
Total power received from the served user (optimum beamformer)
J
RN
2 n
Rn + RI =
I+
pj Sj Sj
H
j=1 2
n I
Rn J
RI
pj Sj Sj
H
j=1
Pˆ N
S RN S
Pˆ
p S RN S
CINR UL
P H Pˆ –1 ------ = ------ = p S R N S PN Pˆ N
None
C/(I+N) in the uplink (WiMAX)
Q UL
P H Pˆ –1 ------ = ------ = p S R N S ˆP PN N
None
Signal quality in the uplink (TD-SCDMA)
G SA
S I S = E SA
None
Uplink smart antenna beamforming gain in the direction of the served user
W
Average inverse noise correlation matrix
W
Uplink interference
None
Angular distribution of uplink noise rise
SA
H
2
–1
H
2
–1
H
2
K –1 RN Avg
--1- K
RN
–1 k
k=1
I UL
E SA 2 ------------------------------------ – n H –1 S RN S Avg
2
NR UL
I UL + n --------------------------2 n
1.6.2 Downlink Beamforming
Figure 1.18: Downlink Beamforming Beamforming dynamically creates a beam towards the served user. The smart antenna processor applies complex weights, w n , to each antenna element in order to form a beam towards the served user. The magnitude of these complex weights is
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set to 1. The beamforming is performed using only the phase of the complex weights. The steering vector, S , representing the complex weights for forming a beam towards the served user, i.e., at the angle of arrival is given by: S = 1 e
2 j ------ d sin
e
2 j ------ 2d sin
... e
T 2 j ------ E – 1 d sin SA
Where T represents the transpose of a matrix. Therefore, the complex weight at any nth antenna element can be given by: wn = e
2 – j ------ nd sin
– j n sin In Atoll, d = --- , therefore, w n = e . 2
The smart antenna gain in any direction can be given by: H
G SA = g n S R S Where H represents the Hilbert transform, which is the complex conjugate transpose of a matrix, g n is the gain of the nth antenna element in the direction , and R is the array correlation matrix for a given user direction , given by: H
R = S S
For the direction of the served user, i.e., , the smart antenna gain is calculated as follows: H
H
H
2
G SA = g n S R S = g n S S S S = g n E SA The smart antenna gain includes the gain of the beamforming as well as the gain of power combination. The smart antenna gain in dB will be G SA = 10 Log G SA . The smart antenna is able to form the beam only in the horizontal plane, therefore, the vertical pattern is assumed to remain the same. Power Combining Gain Cell transmission power is fed to each antenna element of the smart antenna system. Since each element transmits the same input power, this results in a gain due to power combination, i.e., the powers fed to each antenna element are combined for transmission. Additional Processing in Monte Carlo Simulations During Monte Carlo simulations, Atoll calculates the smart antenna gains (array correlation matrix R ) for each served mobile in a cell’s coverage area in each iteration. The sum of these array correlation matrices for all the users served in one iteration k is calculated as follows: J
Rk =
pj Rj j=1
Where R k for any cell is the downlink array correlation matrix for iteration k, J is the number of served mobiles during the iteration, p j is the EIRP transmitted towards the mobile j, and R j is the array correlation matrix for the mobile j. Atoll calculates a moving average of the array correlation matrices calculated in each iteration. At the end of a simulation with K iterations, the average downlink array correlation matrix for any cell is given by: K
1 R Avg = --- K
Rk k=1
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1.6.3 Uplink Beamforming
Figure 1.19: Uplink Beamforming Let w represent the vector of ESA complex weights for the beamformer. w is given by: S w = ----------E SA Where S is the steering vector in the direction of the served user, . The total noise received in the uplink, i.e., interference and thermal noise, is stored in a total noise correlation matrix, R N . The total noise correlation matrix is the sum of the thermal noise correlation matrix R n , and the interference correlation matrix R I , given by: J
RN = Rn + RI =
2 n
I+
pj Sj Sj
H
j=1 J 2
Where R n = n I and R I =
pj Sj Sj
H
j=1 2
n is the thermal noise power. I is the identity matrix. p j is the power received by one element of the smart antenna from the jth interfering mobile. S j is the steering vector in the direction of the jth interfering mobile, . J is the total number of interfering mobiles. The total noise power, including thermal noise and interference from all uplink interferers, received by a cell is given by: H
PN = w RN w And, the total power received from the served user is given by: H
H
P = p w S S w = p E SA Where p is the power received by one element of the smart antenna from the served user. In TD-SCDMA, the uplink signal quality is calculated by: p E SA P SA Q UL = ------ = -------------------------H PN w RN w In WiMAX, the C/(I+N) in the uplink is then calculated by: P p E SA CINR UL = ------ = -------------------------H PN w RN w
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From the above equation, we can determine the uplink smart antenna beamforming gain in the direction of the served user, which equals the number of smart antenna elements, i.e., G SA = E SA . Additional Processing in Monte Carlo Simulations The noise correlation matrix R N for each iteration k includes the effect of the matrix calculated for the previous iteration. The result is the angular distribution of the uplink load (TD-SCDMA) or the uplink noise rise (WiMAX), which is calculated from the noise correlation matrix obtained at the end of the last iteration of a Monte Carlo simulation. This angular distribution of the uplink load (TD-SCDMA) or the uplink noise rise (WiMAX) can be stored in the Cells table. The average of the noise correlation matrices is calculated as follows: K
RN
Avg
1 = --- K
RN k k=1
Where R N
Avg
is the average of the noise correlation matrices of all the iterations from k = 1 to K, and R N
k
is the noise
correlation matrix of the kth iteration. The interference can be isolated from the thermal noise and can be calculated for any direction using the formula. H
I UL = w R N
2
Avg
w – n
Where I UL is the interfering signal in the direction , ESA is the number of smart antenna elements, S is the steering 2
vector in the direction , and n is the thermal noise power. In TD-SCDMA, the uplink load is calculated from the average noise correlation matrix. In WiMAX, the angular distribution of the uplink noise rise is given by: 2
I UL + n NRUL = --------------------------2 n
1.6.4 Uplink Beamforming and Interference Cancellation (MMSE) The optimum beamformer uses the Minimum Mean Square Error algorithm in the uplink in order to cancel interference. The Minimum Mean Square Error algorithm optimizes the useful signal as well as maximizes the signal quality. A simple null steering beamformer can cancel the interference from the most interfering E SA – 1 interfering mobiles. The optimum beamforming method used in Atoll overcomes this limitation. It calculates the optimum smart antenna weights using the knowledge of directions and power levels of interference. These weights do not try to fully cancel E SA – 1 interference signals, but rather try to reduce the overall received interference as much as possible.
Figure 1.20: Uplink Adaptive Algorithm ˆ represent the vector of ESA complex weights for the beamformer. w ˆ is given by: Let w
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ˆ = R –N1 S w Where S is the steering vector in the direction of the served user, . , which is a constant value for a given useful signal that optimizes the beamformer weights. It is given by the equation: E SA = ----------------------------H –1 S RN S –1
R N is the inverse of the total noise correlation matrix. The total noise correlation matrix is the sum of the thermal noise correlation matrix R n , and the interference correlation matrix R I , given by: J
RN = Rn + RI =
2 n
I+
pj Sj Sj
H
j=1 J
Where R n =
2 n
pj Sj Sj
I and R I =
H
j=1 2
n is the thermal noise power. I is the identity matrix. p j is the power received by one element of the smart antenna from the jth interfering mobile. S j is the steering vector in the direction of the jth interfering mobile, . J is the total number of interfering mobiles. The total noise power, including thermal noise and interference from all uplink interferers, received by a cell is given by: H 2 –1 Pˆ N = S R N S
And, the total power received from the served user is given by: 2 H 2 –1 Pˆ = p S R N S
Where p is the power received by one element of the smart antenna from the served user. In TD-SCDMA, the uplink signal quality is calculated by: H Pˆ SA –1 Q UL = ------ = p S R N S Pˆ N
In WiMAX, the C/(I+N) in the uplink is then calculated by: H Pˆ –1 CINR UL = ------ = p S R N S ˆP N
From the above equation, we can determine the uplink smart antenna beamforming gain in the direction of the served user. RSCP TCH – UL (TD-SCDMA) or C UL (WiMAX) can be calculated from the above equation by considering the interference and –1
noise to be null, i.e., R N = I . This gives: H
In TD-SCDMA, RSCP TCH – UL = p S I S = p E SA H
In WiMAX, C UL = p S I S = p E SA From the above equation, the uplink smart antenna beamforming gain equals the number of smart antenna elements, i.e., G SA = E SA . Additional Processing in Monte Carlo Simulations –1
The inverse noise correlation matrix R N for each iteration k includes the effect of the matrix calculated for the previous iteration. Hence, Atoll is able to calculate an average of the smart antenna interference-cancellation effect. The result is the angular distribution of the uplink load (TD-SCDMA) or the uplink noise rise (WiMAX), which is calculated from the inverse of the noise correlation matrix obtained at the end of the last iteration of a Monte Carlo simulation. This angular distribution of the uplink load (TD-SCDMA) or the uplink noise rise (WiMAX) can be stored in the Cells table. The average of the inverse noise correlation matrices is calculated as follows:
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1 = --- K
RN
–1 k
k=1 –1
Where R N
–1
Avg
is the average of the inverse noise correlation matrices of all the iterations from k = 1 to K, and R N
k
is the
inverse noise correlation matrix of the kth iteration. The interference can be isolated from the thermal noise and can be calculated for any direction using the formula. E SA 2 I UL = ------------------------------------ – n H –1 S RN S Avg
Where I UL is the interfering signal in the direction , ESA is the number of smart antenna elements, S is the steering 2
vector in the direction , and n is the thermal noise power. In TD-SCDMA, the uplink load is calculated from the average inverse noise correlation matrix. In WiMAX, the angular distribution of the uplink noise rise is given by: 2
I UL + n NRUL = --------------------------2 n
1.7 Grid-of-Beams Smart Antenna Model A grid-of-beams smart antenna, called GOB, consists of more than one directional antenna pattern (beam) in different directions. Each beam of a GOB has a different azimuth so that the GOB as a whole covers an entire sector. During the simulations, Atoll determines the most suitable beam from the GOB for each user served by the smart antenna. The most suitable beam (best beam) is the one which provides the highest gain towards the served user: BeamBest = Beam H
H V Max G Beam – L Beam – L Beam V
Where G Beam , L Beam , and L Beam are the gains, horizontal, and vertical attenuations of the beams of the GOB. In words, the best beam is the one among all the beams of a GOB that has the highest difference between gain, and horizontal and vertical SA
SA
SA
SA
attenuations. The gains and losses of the GOB ( G DL , G UL , L DL , and L UL ) are determined from the selected best beam. The following example shows how Atoll calculates the GOB gains and losses. Example: Let us assume a GOB with 5 beams that have the same vertical patterns, and whose horizontal patterns are pointed towards different directions as shown in the figure below:
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Figure 1.21: Grid Of Beams Modelling Let us assume that all the beams and the main antenna have the same 18 dBi gain, and the vertical attenuation at the user location is 15 dB, which is also the same for all the beams because we assume that the vertical patterns are the same. If the user is located at = 70 azimuth, as shown in the figure below, Atoll determines the best beam, which has the highest gain towards , as follows: Beam
Gain (dBi)
Horizontal Vertical Attenuation (dB) Attenuation (dB)
G Beam – L Beam – L Beam
Total Gain (dB)
H
V
0°
18
60
15
18 - 60 - 15
-57
30°
18
60
15
18 - 60 - 15
-57
60°
18
2.21
15
18 - 2.21- 15
0.79
-30°
18
60
15
18 - 60 - 15
-57
-60°
18
60
15
18 - 60 - 15
-57
Transmitter Centre of the pixel where the served user is located
Angle between the user and the transmitter azimuth
Figure 1.22: GOB Modelling - Determination of the Best Beam In our example, the total gain of the beam at 60° is the highest. Therefore this beam is selected as the best beam. If this beam has been selected in the downlink, SA
SA
H
V
G DL = 18 dB and L DL = L Beam + L Beam = 17.21 dB If this beam has been selected in the uplink, SA
SA
H
V
G UL = 18 dB and L UL = L Beam + L Beam = 17.21 dB
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1.8 Adaptive Beam Smart Antenna Model An adaptive beam smart antenna is capable of steering a given antenna pattern towards the direction of the served signal. In Atoll, this is modelled using a single antenna pattern, called a beam because of its highly directional shape. During the simulations, this adaptive beam is oriented in the direction of each served user in order to model the effect of the smart antenna. SA
SA
SA
The adaptive beam gains ( G DL and G UL ) are the antenna gains defined for the beam, and the adaptive beam losses ( L DL and SA
H
V
L UL ) are the horizontal and vertical pattern attenuations L Beam + L Beam towards the user direction. The following example shows how Atoll calculates the adaptive beam gains and losses. Example: Let us assume an adaptive beam smart antenna selected for a transmitter along with a main antenna. Let us assume that the adaptive beam and the main antenna have the same 18 dBi gain, and the vertical attenuation at the user location is 15 dB. If the user is located at = 60 azimuth, as shown in the figure below:
Transmitter Centre of the pixel where the served user is located
Angle between the user and the transmitter azimuth
Figure 1.23: Adaptive Beam Modelling - Determination of the Best Beam If the adaptive beam smart antenna is selected in the downlink, the gain and losses of the adaptive beam at are: SA
SA
H
V
G DL = 18 dB and L DL = L Beam + L Beam = 15 dB If the adaptive beam smart antenna is selected in the uplink, the gain and losses of the adaptive beam at are: SA
SA
H
V
G UL = 18 dB and L UL = L Beam + L Beam = 15 dB H
In fact, as the ideal beam steering algorithm steers the beam towards the served user, L Beam = 0 . These values are used in interference calculation to determine the downlink interfering signal due to transmission towards the served user, as well as for calculating the uplink interfering signals received at transmitter when decoding signal received from the served user.
1.9 Statistical Smart Antenna Gain Model A statistical modelling approach is also available in Atoll which can be used to model the effect of smart antennas through C/ I gains. You can create smart antenna equipment in Atoll based on the statistical approach by providing C/I gains and their cumulative probabilities for different spreading angles, Spread . You can assign a spreading angle to each clutter class in your document. Atoll reads the clutter class in which the served user is located to determine the spreading angle. Different clutter types have different spreading effects on the propagation of radio waves. Urban and dense urban clutter types introduce more multipath and spread the signal at a wider angle than an open or rural clutte type. Once you have assigned the spreading angles to clutter classes, you can enter the C/I gains and their cumulative probabilities for each spreading angle, in the smart antenna equipment based on the statistical model. For each smart antenna equipment based on statistical modelling, you can set a probability threshold, TProb
SA
.
To find the smart antenna gain, Atoll determines the clutter class of the served user, it reads the spreading angle from the clutter class properties, it reads the probability threshold from the smart antenna properties, and reads the smart antenna C/ I gain defined for the Probability = 1 – TProb
SA
corresponding to the spreading angle.
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The following example shows how Atoll calculates the statistical C/I gains and losses. Example: Let us assume that the served user is located at a an urban clutter class with Spread = 10 . The smart antenna equipment SA
SA
has TProb = 80 % . Atoll will read the smart antenna C/I gain G for Prob = 20 % . If a gain for the exact probability value of 20% is not defined, Atoll linearly interpolates the gain value from the two surrounding values. If G
SA Prob = 19%
= 4.6298 dB and G
SA Prob = 20.4%
= 4.7196 dB , then G
SA Prob = 20%
= 4.6941 dB
The smart antenna gains are the same for uplink and downlink. Their are no losses for this type of smart antenna equipment. Negative values of C/I gains are considered as losses.
54
Chapter 2 Radio Propagation This chapter covers the following topics: •
"Path Loss Calculation Prerequisites" on page 57
•
"List of Default Propagation Models" on page 62
•
"Okumura-Hata and Cost-Hata Propagation Models" on page 63
•
"ITU 529-3 Propagation Model" on page 64
•
"Standard Propagation Model (SPM)" on page 65
•
"WLL Propagation Model" on page 75
•
"ITU-R P.526-5 Propagation Model" on page 76
•
"ITU-R P.370-7 Propagation Model" on page 76
•
"Erceg-Greenstein (SUI) Propagation Model" on page 78
•
"ITU-R P.1546-2 Propagation Model" on page 80
•
"Sakagami Extended Propagation Model" on page 84
•
"Free Space Loss" on page 86
•
"Diffraction" on page 86
•
"Shadow Fading Model" on page 90
•
"Path Loss Matrices" on page 103
•
"File Formats" on page 107
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2 Radio Propagation Path loss calculations are carried out between a transmitter and a receiver using propagation models and other calculations related to radio wave propagation such as diffraction and shadow fading. Propagation models are mathematical representations of the average loss in signal strength over distance. Diffraction loss and shadow fading margins are added to this average loss in order to get more precise path loss values. Path loss matrices are calculated for each transmitter and their results used in other calculations (coverage predictions, Monte Carlo simulations, point analysis, etc.). The method of calculation may differ depending on the analysis being performed: Analysis type
Receiver position
Calculation
Profile extraction
Result
Coverage predictions
Centre of each bin inside the calculation area
Based on path loss matrices
Radiala
One value for the bin’s surface area
Point analysis (Profile)
Anywhere
Real-time
Systematic
Different values inside a calculation bin
Point analysis (other)
Anywhere inside the calculation areas
Based on path loss matrices
Radiala
One value for the bin’s surface area
Monte Carlo simulations
Mobile coordinates
Based on path loss matrices
Radiala
One value at the mobile location
Subscriber lists
Subscriber coordinates
Real-time
Radiala
One value at the subscriber location
a.
With the Standard Propagation Model, you can choose between radial or systematic.
This chapter describes the various propagation models available in Atoll, and other radio wave propagation phenomena such as diffraction and shadow fading.
2.1 Path Loss Calculation Prerequisites 2.1.1 Ground Altitude Determination Atoll determines reception and transmission site altitude from Digital Terrain Model map. The method used to evaluate site altitude is based on a bilinear interpolation. DTM files provide altitude value z (in metre) on evenly spaced points. Abscissa and ordinate axes are respectively oriented in right and downwards directions. Space between points is defined by pixel size P (in metre). Pixel size must be the same in both directions. The first point given in the file corresponds to the centre of the top-left pixel of the map (northwest point georeferenced by Atoll).
Figure 2.1: Digital Terrain Model Four points (hence, four altitude values) are necessary to describe a “bin”; these points are bin vertices. Therefore, a DTM file that contains N x N bins requires N2 points (altitude values).
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Figure 2.2: Schematic view of a DTM file •
In Atoll, DEM (Digital Elevation Model) is the same as Digital Terrain Model (DTM). In literature, DEM and DTM do not always have the same meaning. By definition, DEM refers to the altitude above sea level including ground and clutter, while DTM refers to the ground altitude above sea level alone.
Let us suppose a site S located inside a bin. Atoll knows the altitudes of four bin vertices, S’1, S’’1, S’2 and S’’2, from the DTM file (centre of each DTM pixel).
Figure 2.3: Ground Altitude Determination - 1 1. Atoll draws a vertical line through S. This line respectively intersects (S’1,S’’1) and (S’2, S’’2) lines at S1 and S2.
Figure 2.4: Ground Altitude Determination - 2 2. Atoll determines the S1 and S2 altitudes using a linear interpolation method.
Figure 2.5: Ground Altitude Determination - 3 3. Atoll performs a second linear interpolation to evaluate the S altitude.
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Figure 2.6: Ground Altitude Determination - 4
2.1.2 Clutter Determination Some propagation models need clutter class and clutter height as information at receiver or along a transmitter-receiver profile.
2.1.2.1 Clutter Classes Atoll uses clutter classes file to determine the clutter class. The clutter classes map is a grid representing the ground with each bin assigned a clutter class code corresponding to its clutter type. It is possible to specify an average height for each clutter class in Atoll. Clutter class files provide a clutter code per bin. Bin size is defined by pixel size P (in metre). Pixel size must be the same in both directions. Abscissa and ordinate axes are respectively oriented in right and downwards directions. The first point given in the file corresponds to the centre of the top-left pixel of the map (northwest point geo-referenced by Atoll.
Figure 2.7: Clutter Classes Atoll supports a maximum of 255 clutter classes (8 bits/pixel). A clutter classes file file that contains N x N bins requires N2 code values.
2.1.2.2 Clutter Heights To evaluate the clutter height, Atoll uses clutter heights file if available in the .atl document; clutter height of a site is the height of the nearest point in the file. Example: Let us suppose a site S. In the clutter heights file, Atoll reads clutter heights of four points around the site, S’1, S’’1, S’2 and S’’2. Here, the nearest point to S is S”2; therefore Atoll takes the S”2 clutter height as clutter height of S.
Figure 2.8: Clutter Height If you do not have any clutter height file, Atoll takes clutter height information in clutter classes file. In this case, clutter height is an average height related to a clutter class.
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2.1.3 Geographic Profile Extraction Geographic profile extraction is needed in order to calculate diffraction losses. Profiles can be based on DTM only or on DTM and clutter both, depending on the selected propagation model. Method 1: Radial Extraction Atoll draws radials from the site (where transmitter is located) to each calculation bin located along the transmitter calculation area border. In other words, Atoll determines a geographic profile between site and each bin centre.
Figure 2.9: Radial calculation method Transmitter location Radials (Atoll extracts a geographic profile for each radial) Centres of bins located on the calculation border Receiver location
Figure 2.10: Site-bin centre profile Depending on the calculation being carried out, the receiver may be located at the centre of a calculation bin (coverage predictions) or anywhere within a calculation bin. Atoll uses the profile nearest to the receiver for calculations (the receiver is assumed to be located on the profile).
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Method 2: Systematic Extraction Atoll extracts a precise geographic profile between the site and the receiver.
Figure 2.11: Radial calculation method Transmitter location Geographic profile Receiver location
2.1.4 Resolution of the Extracted Profiles Geographic profile resolution depends on resolution of geographic data used by the propagation model (DTM and/or clutter). The selected profile resolution does not depend on the geographic layer order. •
If the propagation model uses both DTM and clutter heights along the profile, the profile resolution will be the highest of the two. Example 1 (Using the Standard Propagation Model) A DTM map with a 40 m resolution and a clutter heights map with a 20 m resolution are available. The profile resolution will be 20 m. It means that Atoll will extract geographic information, ground altitude and clutter height, every 20 m. To get ground altitude every 20 m, Atoll uses the bilinear interpolation method described in "Ground Altitude Determination" on page 57. Clutter heights are read from the clutter heights map. Atoll takes the clutter height of the nearest point every 20 m. Example 2 (Using the Standard Propagation Model) A DTM map with a 40 m resolution and a clutter classes map with a 20 m resolution are available. No clutter height file has been imported in the document. The profile resolution will be 20 m. It means that Atoll will extract geographic information, ground altitude and clutter height, every 20 m. To get ground altitude every 20 m, Atoll uses the bilinear interpolation method described in "Ground Altitude Determination" on page 57. Atoll uses the clutter classes map to determine clutter height. Every 20 m, it determines clutter class and takes associated average height.
•
If the propagation model uses only DTM along the profile, the profile resolution will be the highest resolution among the DTM files. Example (Using the Cost-Hata Propagation Model)
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DTM maps with 40 m and 25 m resolutions and a clutter map with a 20 m resolution are available. The profile resolution will be 25 m. It means that Atoll will extract geographic information, only the ground altitude, every 25 m. The profile resolution does not depend on the geographic layer order in the Geo tab of the Explorer window. However, the geographic layer order has influence on the usage of the data. For example, when DTM 1 is on the top of DTM 2, Atoll will use DTM 1 for extracting the profile where DTM a is available and it will use DTM 2 elsewhere. To get ground altitude every 25 m, Atoll uses the bilinear interpolation method described in "Ground Altitude Determination" on page 57. Geo Tab of the Explorer Window > DTM > DTM 1 (25m) > DTM 2 (40m) > Clutter > Clutter (20m)
2.2 List of Default Propagation Models Propagation models available in Atoll are listed in the table below along with their main characteristics. Propagation model
ITU 370-7 (Vienna 93)
ITU 1546
ITU 526-5
WLL
Frequency band
100-400 MHz
30-3000 MHz
30-10000 MHz
30-10000 MHz
Physical phenomena
Free space loss Corrected standard loss
Free space loss + corrections
Free space loss Diffraction loss
Free space loss Diffraction loss
Diffraction calculation method
-
-
Deygout (3 obstacles) Deygout corrected (3 obstacles)
Deygout (3 obstacles)
Profile based on
-
-
DTM
DTM Clutter
Profile extraction mode
-
-
Radial
Radial
Cell size
Macro cell
Macro cell
Macro cell
-
Receiver location
Rooftop
Rooftop
Street
Street Rooftop
Receiver
Fixed
Mobile
Fixed
Fixed
Use
d > 10 km Low frequencies Broadcast
1 < d < 1000 km Land and maritime mobile, broadcast
Fixed receivers WLL
Fixed receivers WLL, Microwave links, WiMAX
Propagation model
Standard Propagation Model
Erceg-Greenstein (SUI)
ITU 529-3
COST-Hata Okumura-Hata
Frequency band
150-3500 MHz
1900-6000 MHz
300-1500 MHz
150-2000 MHz
Physical phenomena
L(d, HTxeff, HRxeff, Diff loss, clutter)
L(d, f, HTx, HRx) (per environment) Diffraction loss
L(d, f, HRx) (per environment) Diffraction loss
L(d, f, HRx) (per environment) Diffraction loss
Diffraction calculation method
Deygout (3 obstacles) Epstein-Peterson (3 obstacles) Deygout corrected (3 obstacles) Millington (1 obstacle)
Deygout (1 obstacle)
Deygout (1 obstacle)
Deygout (1 obstacle)
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Propagation model
Standard Propagation Model
Erceg-Greenstein (SUI)
ITU 529-3
COST-Hata Okumura-Hata
Profile based on
DTM Clutter
DTM
DTM
DTM
Profile extraction mode
Radial Systematic
Radial
Radial
Radial
Cell size
Macro cell Mini cell
Macro cell Mini cell
Macro cell Mini cell
Macro cell Mini cell
Receiver location
Street Rooftop
Street
Street
Street
Receiver
Mobile and Fixed
Fixed
Mobile
Mobile
Use
1 < d < 20 km GSM, UMTS, CDMA2000, WiMAX, LTE
Urban and suburban areas 100 m < d < 8 km Fixed WiMAX
1 < d < 100 km GSM, CDMA2000, LTE
GSM, UMTS, CDMA2000, LTE
2.3 Okumura-Hata and Cost-Hata Propagation Models 2.3.1 Hata Path Loss Formula Hata formula empirically describes the path loss as a function of frequency, receiver-transmitter distance and antenna heights for an urban environment. This formula is valid for flat, urban environments and 1.5 metre mobile antenna height. Path loss (Lu) is calculated (in dB) as follows: Lu = A 1 + A 2 log f + A 3 log h Tx + B 1 + B 2 log h Tx + B 3 h Tx log d f is the frequency (MHz). hTx is the transmitter antenna height above ground (m) (Hb notation is also used in Atoll). d is the distance between the transmitter and the receiver (km). The parameters A1, A2, A3, B1, B2, and B3 can be user-defined. Default values are proposed in the table below: Parameters
Okumura-Hata f 1500 MHz
Cost-Hata f > 1500 MHz
A1
69.55
49.30
A2
26.16
33.90
A3
-13.82
-13.82
B1
44.90
44.90
B2
-6.55
-6.55
B3
0
0
2.3.2 Corrections to the Hata Path Loss Formula As described above, the Hata formula is valid for urban environment and a receiver antenna height of 1.5m. For other environments and mobile antenna heights, corrective formulas must be applied. •
For urban areas: L model1 = Lu – a h Rx
•
f 2 For suburban areas: L model1 = Lu – a h Rx – 2 log ------ – 5.4 28
•
For quasi-open rural areas: L model1 = Lu – a h Rx – 4.78 log f + 18.33 log f – 35.94
•
For open rural areas: L model1 = Lu – a h Rx – 4.78 log f + 18.33 log f – 40.94
2
2
a(hRx) is a correction for a receiver antenna height different from 1.5m. •
For rural/small cities: a h Rx = 1.1 log f – 0.7 h Rx – 1.56 log f – 0.8
•
For large cities: a h Rx = 3.2 log 11.75h Rx – 4.97
2
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When receiver antenna height equals 1.5m, a(hRx) is close to 0 dB regardless of frequency.
2.3.3 Calculations in Atoll Hata models take into account topo map (DTM) between transmitter and receiver and morpho map (clutter) at the receiver. 1st step: For each calculation bin, Atoll determines the clutter bin on which the receiver is located. This clutter bin corresponds to a clutter class. Then, it uses the Hata formula assigned to this clutter class to evaluate L model1 . 2nd step: This step depends on whether the ‘Add diffraction loss’ option is checked. •
If the ‘Add diffraction loss’ option is unchecked, Atoll stops calculations. L model = L model1
•
If the ‘Add diffraction loss’ option is selected, Atoll proceeds as follows: a. It extracts a geographic profile between the transmitter and the receiver based on the radial calculation mode. b. It determines the largest obstacle along the profile in accordance with the Deygout method and evaluates losses due to diffraction L model2 . L model = L model1 + L model2
2.4 ITU 529-3 Propagation Model 2.4.1 ITU 529-3 Path Loss Formula The ITU 529.3 model is a Hata-based model. For this reason, its formula empirically describes the path loss as a function of frequency, receiver-transmitter distance and antenna heights for a urban environment. This formula is valid for flat, urban environments and 1.5 metre mobile antenna height. The standard ITU 529-3 formula, for a receiver located on a urban environment, is given by: E = 69.82 – 6.16 log f + 13.82 log h Tx – 44.9 – 6.55 log h Tx log d
b
where: E is the field strength for 1 kW ERP f is the frequency (MHz). h Tx is the transmitter antenna height above ground (m) (Hb notation is also used in Atoll) h Rx is the receiver antenna height above ground (m) d is the distance between the transmitter and the receiver (km) b is the distance correction The domain of validity of such is formula is: • • • •
Frequency range: 300-1500 MHz Base Station height: 30-200 m Mobile height: 1-10 m Distance range: 1-100 km
Since Atoll needs the path loss (Lu) formula, a conversion has to be made. One can find the following conversion formula: Lu = 139.37 + 20 log f – E which gives the following path loss formula for the ITU 529-3 model: Lu = 69.55 + 26.16 log f – 13.82 log h Tx + 44.9 – 6.55 log hTx log d
b
2.4.2 Corrections to the ITU 529-3 Path Loss Formula Environment Correction As described above, the Hata formula is valid for urban environment. For other environments and mobile antenna heights, corrective formulas must be applied.
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L model1 = Lu – a h Rx for large city and urban environments f 2 L model1 = Lu – a h Rx – 2 log ------ – 5.4 for suburban area 28 2
L model1 = Lu – a h Rx – 4.78 log f + 18.33 log f – 40.94 for rural area Area Size Correction In the formulas above, a h Rx is the environment correction and is defined according to the area size. •
For rural/small cities: a h Rx = 1.1 log f – 0.7 h Rx – 1.56 log f – 0.8
•
For large cities: a h Rx = 3.2 log 11.75h Rx – 4.97
2
Distance Correction The distance correction refers to the term b above. •
d20 km: b = 1 + 0.14 + 1.87 10 f + 1.07 10 h' Tx log ------ with h' Tx = ---------------------------------------- 20 –6 2 1 + 7 10 h Tx
2.4.3 Calculations in Atoll Hata-based models take into account topo map (DTM) between transmitter and receiver and morpho map (clutter) at the receiver. 1st step: For each calculation bin, Atoll determines the clutter bin on which the receiver is located. This clutter bin corresponds to a clutter class. Then, it uses the ITU 529-3 formula assigned to this clutter class to evaluate L model1 . 2nd step: This step depends on whether the ‘Add diffraction loss’ option is checked. •
If the ‘Add diffraction loss’ option is unchecked, Atoll stops calculations. L model = L model1
•
If the ‘Add diffraction loss’ option is selected, Atoll proceeds as follows: a. It extracts a geographic profile between the transmitter and the receiver based on the radial calculation mode. b. It determines the largest obstacle along the profile in accordance with the Deygout method and evaluates losses due to diffraction L model2 . L model = L model1 + L model2
2.5 Standard Propagation Model (SPM) 2.5.1 SPM Path Loss Formula SPM is based on the following formula: L model = K 1 + K 2 log d + K 3 log H Txeff + K 4 DiffractionLoss + K 5 log d log H Txeff + K 6 H Rxeff + K 7 log H Rxeff + K clutter f clutter with, K1: constant offset (dB). K2: multiplying factor for log(d). d: distance between the receiver and the transmitter (m). K3: multiplying factor for log(HTxeff). HTxeff: effective height of the transmitter antenna (m). K4: multiplying factor for diffraction calculation. K4 has to be a positive number.
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Diffraction loss: loss due to diffraction over an obstructed path (dB). K5: multiplying factor for log d log H Txeff K6: multiplying factor for H Rxeff K7: multiplying factor for log H Rxeff . H Rxeff : effective mobile antenna height (m). Kclutter: multiplying factor for f(clutter). f(clutter): average of weighted losses due to clutter.
2.5.2 Calculations in Atoll 2.5.2.1 Visibility and Distance Between Transmitter and Receiver For each calculation bin, Atoll determines: •
The distance between the transmitter and the receiver.
If the distance Tx-Rx is less than the maximum user-defined distance (break distance), the receiver is considered to be near the transmitter. Atoll will use the set of values marked “Near transmitter”. If the distance Tx-Rx is greater than the maximum distance, receiver is considered far from transmitter. Atoll will use the set of values “Far from transmitter”. •
Whether the receiver is in the transmitter line of sight or not.
If the receiver is in the transmitter line of sight, Atoll will take into account the set of values (K1,K2)LOS. The LOS is defined by no obstruction along the direct ray between the transmitter and the receiver. If the receiver is not in the transmitter line of sight, Atoll will use the set of values (K1,K2)NLOS.
2.5.2.2 Effective Transmitter Antenna Height Effective transmitter antenna height (HTxeff) may be calculated with six different methods. Height Above Ground The transmitter antenna height is above the ground (HTx in m). HTxeff = HTx Height Above Average Profile The transmitter antenna height is determined relative to an average ground height calculated along the profile between a transmitter and a receiver. The profile length depends on distance min and distance max values and is limited by the transmitter and receiver locations. Distance min and Distance max are minimum and maximum distances from the transmitter respectively. H Txeff = H Tx + H 0Tx – H 0 where, H 0Tx is the ground height (ground elevation) above sea level at transmitter (m). H 0 is the average ground height above sea level along the profile (m). If the profile is not located between the transmitter and the receiver, HTxeff equals HTx only.
Slope at Receiver Between 0 and Minimum Distance The transmitter antenna height is calculated using the ground slope at receiver. H Txeff = H Tx + H 0Tx – H 0Rx + K d where,
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H 0Rx is the ground height (ground elevation) above sea level at receiver (m). K is the ground slope calculated over a user-defined distance (Distance min). In this case, Distance min is a distance from receiver. •
If H Txeff 20m then, Atoll uses 20m in calculations.
•
If H Txeff 200m then, Atoll takes 200m.
Spot Ht If H 0Tx H 0Rx then, H Txeff = H Tx + H 0Tx – H 0Rx If H 0Tx H 0Rx then, H Txeff = H Tx Absolute Spot Ht H Txeff = H Tx + H 0Tx – H 0Rx Distance min and distance max are set to 3000 and 15000 m according to ITU recommendations (low frequency broadcast f < 500 Mhz) and to 0 and 15000 m according Okumura recommendations (high frequency mobile telephony). These values are only used in the two last methods and have different meanings according to the method. Enhanced Slope at Receiver Atoll offers a new method called “Enhanced slope at receiver” to evaluate the effective transmitter antenna height.
Figure 2.12: Enhanced Slope at Receiver Let x-axis and y-axis respectively represent positions and heights. We assume that x-axis is oriented from the transmitter (origin) towards the receiver. This calculation is achieved in several steps: 1. Atoll determines line of sight between transmitter and receiver. The LOS line equation is: H 0Tx + H Tx – H 0Rx + H Rx - Res i Los i = H 0Tx + H Tx – ----------------------------------------------------------------------d where, H Rx is the receiver antenna height above the ground (m). i is the point index. Res is the profile resolution (distance between two points). 2. Atoll extracts the transmitter-receiver terrain profile.
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3. Hills and mountains are already taken into account in diffraction calculations. Therefore, in order for them not to unfavourably influence the regression line calculation, Atoll filters the terrain profile. Atoll calculates two filtered terrain profiles; one established from the transmitter and another from the receiver. It determines filtered height of every profile point. Profile points are evenly spaced on the basis of profile resolution. To determine filtered terrain height at a point, Atoll evaluates ground slope between two points and compares it with a threshold set to 0.05; where three cases are possible. Some notations defined hereafter are used in next part. H filt is the filtered height. H orig is the original height. Original terrain height is determined from extracted ground profile. •
Filter starting from transmitter Let us assume that H filt – Tx Tx = H orig Tx For each point, we have three different cases: i.
H orig i – H orig i – 1 - 0.05 , If H orig i H orig i – 1 and --------------------------------------------------Res Then, H filt – Tx i = H filt – Tx i – 1 + H orig i – H orig i – 1
H orig i – H orig i – 1 - 0.05 ii. If H orig i H orig i – 1 and --------------------------------------------------Res Then, H filt – Tx i = H filt – Tx i – 1 iii. If H orig i H orig i – 1 Then, H filt – Tx i = H filt – Tx i – 1 If H filt i H orig i additionally Then, H filt – Tx i = H orig i •
Filter starting from receiver
Let us assume that H filt Rx = H orig Rx For each point, we have three different cases: i.
H orig i – H orig i + 1 - 0.05 , If H orig i H orig i + 1 and --------------------------------------------------Res Then, H filt – Rx i = H filt – Rx i + 1 + H orig i – H orig i + 1
H orig i – H orig i + 1 ii. If H orig i H orig i + 1 and ---------------------------------------------------- 0.05 Res Then, H filt – Rx i = H filt – Rx i + 1 iii. 3rd case: If H orig i H orig i + 1 Then, H filt – Rx i = H filt – Rx i + 1 If H filt i H orig i additionally Then, H filt – Rx i = H orig i Then, for every point of profile, Atoll compares the two filtered heights and chooses the higher one. H filt i = max H filt – Tx i H filt – Rx i 4. Atoll determines the influence area, R. It corresponds to the distance from receiver at which the original terrain profile plus 30 metres intersects the LOS line for the first time (when beginning from transmitter). The influence area must satisfy additional conditions: •
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• •
R 0.01 d R must contain at least three bins. • •
When several influence areas are possible, Atoll chooses the highest one. If d < 3000m, R = d.
5. Atoll performs a linear regression on the filtered profile within R in order to determine a regression line. The regression line equation is: y = ax + b
d i – dm Hfilt i – Hm i and b = H m – ad m a = --------------------------------------------------------------------2 d i – dm
i
where, 1 H m = --n
Hfilt i i
i is the point index. Only points within R are taken into account. dm = d – R --2 d(i) is the distance between i and the transmitter (m). Then, Atoll extends the regression line to the transmitter location. Therefore, its equation is: regr i = a i Res + b 6. Then, Atoll calculates effective transmitter antenna height, H Txeff (m). H 0Tx + H Tx – b H Txeff = --------------------------------2 1+a If HTxeff is less than 20m, Atoll recalculates it with a new influence area, which begins at transmitter. •
In case H Txeff 1000m , 1000m will be used in calculations.
•
If H Txeff is still less than 20m, an additional correction is taken into account (7th step).
7. If H Txeff is still less than 20m (even negative), Atoll evaluates path loss using H Txeff = 20m and applies a correction factor. Therefore, if H Txeff 20m , L model = L model H Txeff = 20m d f + K lowant 20 1 – H Txeff – 20 d - – 0.3 H where, K lowant = ------Txeff – 20 – -------------------------------------------------------------------------5 d - 6.93 + ----------d - 9.63 + ----------10 1000 1000
2.5.2.3 Effective Receiver Antenna Height H Rxeff = H Rx + H 0Rx – H 0Tx where, H Rx is the receiver antenna height above the ground (m). H 0Rx is the ground height (ground elevation) above sea level at the receiver (m).
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H 0Tx is the ground height (ground elevation) above sea level at the transmitter (m).
The calculation of effective antenna heights ( H Rxeff and H Txeff ) is based on extracted DTM profiles. They are not properly performed if you have not imported heights (DTM file) beforehand.
2.5.2.4 Correction for Hilly Regions in Case of LOS An optional corrective term enables Atoll to correct path loss for hilly regions when the transmitter and the receiver are in Line-of-sight. Therefore, if the receiver is in the transmitter line of sight and the Hilly terrain correction option is active, we have: L model = K 1 LOS + K 2 LOS log d + K 3 log H Txeff + K 5 log H Txeff log d + K 6 H Rx + K clutter f clutter + K hill LOS When the transmitter and the receiver are not in line of sight, the path loss formula is: L model = K 1 NLOS + K 2 NLOS log d + K 3 log H Txeff + K 4 Diffraction + K 5 log H Txeff log d + K 6 H Rx + K clutter f clutter K hill LOS is determined in three steps. Influence area, R, and regression line are supposed available. 1st step: For every profile point within influence area, Atoll calculates height deviation between the original terrain profile and regression line. Then, it sorts points according to the deviation and draws two lines (parallel to the regression line), one which is exceeded by 10% of the profile points and the other one by 90%. 2nd step: Atoll evaluates the terrain roughness, h; it is the distance between the two lines. 3rd step: Atoll calculates K hill LOS . We have K hill LOS = K h + K hf If 0 h 20m , K h = 0 2
Else K h = 7.73 log h – 15.29 log h + 6.746 If 0 h 10m , K hf = – 2 0.1924 H 0Rx + H Rx – regr i Rx H 0Rx + H Rx – regr i Rx 2 Else K hf = – 2 – 1.616 log h + 14.75 log h – 11.21 ----------------------------------------------------h iRx is the point index at receiver.
2.5.2.5 Diffraction Four methods are available to calculate diffraction loss over the transmitter-receiver profile. Along the transmitter-receiver profile, you may consider: •
Either ground altitude and clutter height (Consider heights in diffraction option), In this case, Atoll uses clutter height information from clutter heights file if available in the .atl document. Otherwise, it considers average clutter height specified for each clutter class in the clutter classes file description.
•
Or only ground altitude.
2.5.2.6 Losses due to Clutter n
Atoll calculates f(clutter) over a maximum distance from receiver: f clutter =
Li wi i=1
where, L: loss due to clutter defined in the Clutter tab by the user (in dB). w: weight determined through the weighting function. n: number of points taken into account over the profile. Points are evenly spaced depending on the profile resolution. Four weighting functions are available:
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•
Uniform weighting function: w i = --1n
•
di Triangular weighting function: w i = -----------n
dj j=1
•
d i = D – d' i , where d’i is the distance between the receiver and the ith point and D is the maximum distance defined.
•
d log ----i + 1 D Logarithmic weighting function: w i = -----------------------------------n d log ----j + 1 D
j=1 di ---D
•
e –1 Exponential weighting function: w i = -----------------------n
e
dj ---D
–1
j=1
The chart below shows the weight variation with the distance for each weighting function.
Figure 2.13: Losses due to Clutter
2.5.2.7 Recommendations Beware that the clutter influence may be taken into account in two terms, Diffraction loss and f(clutter) at the same time. To avoid this, we advise: 1. Not to consider clutter heights to evaluate diffraction loss over the transmitter-receiver profile if you specify losses per clutter class. This approach is recommended if the clutter height information is statistical (clutter roughly defined, no altitude). Or 2. Not to define any loss per clutter class if you take clutter heights into account in the diffraction loss. In this case, f(clutter)=0. Losses due to clutter are only taken into account in the computed Diffraction loss term. This approach is recommended if the clutter height information is either semi-deterministic (clutter roughly defined, altitude defined with an average height per clutter class) or deterministic (clutter sharply defined, altitude defined with an average height per clutter class or - even better - via a clutter height file). In case of semi-deterministic clutter information, specify receiver clearance (m) per clutter class. Both ground altitude and clutter height are considered along the whole transmitter-receiver profile except over a specific distance around the receiver (clearance), where Atoll proceeds as if there was only the DTM map. The clearance information is used to model streets.
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Figure 2.14: Tx-Rx profile In the above figure, the ground altitude and clutter height (in this case, average height specified for each clutter class in the clutter classes map description) are taken into account along the profile. Clearance definition is not necessary in case of deterministic clutter height information. Clutter height information is accurate enough to be used directly without additional information such as clearance. Two cases can be considered: 1. If the receiver is in the street (clutter height lower than receiver height), Atoll calculates the path loss by considering potentially some diffraction loss at reception. 2. If the receiver is supposed to be inside a building (clutter height higher than receiver height), Atoll does not consider any difraction (and clearance) from the building but takes into account the indoor loss as an additional penetration loss. •
•
To consider indoor losses in building only when using a deterministic clutter map (clutter height map), the 'Indoor Coverage' box must not be checked in predictions unless this loss will be counted twice inside buildings (on the entire reception clutter class and not only inside the building). Even with no clearance, the clutter height (extracted either from clutter class or clutter height folders) is never considered at the last profile point.
2.5.3 Automatic Calibration The goal of this tool is to calibrate parameters and methods of the SPM formula in a simple and reproducible way. Calibration is based on imported CW measurement data. It is the process of limiting the difference between predicted and measured values. For a complete description of the calibration procedure (including the very important prerequisite filtering work on the CW measurement points), please refer to the User Manual and the SPM Calibration Guide. The following SPM formula parameters can be estimated: • • • •
K1, K2, K3, K4, K5, K6 and K7 Losses per clutter class (Kclutter must be user-defined) Effective antenna height method Diffraction method
Automatic model calibration provides a mathematical solution. The relevance of this mathematical solution with a physical and realistic solution must be determined before committing these results. You must keep in mind that the model calibration and its result (standard deviation and root mean square) strongly depend on the CW measurement samples you use. A calibrated model must restore the behaviour of CW measurements depending on their configuration on a large scale, and not just totally coincide with a few number of CW measurements. The calibrated model has to give correct results for every new CW measurement point in the same geographical zone, without having been calibrated on these new CW measurements.
2.5.3.1 General Algorithm Propagation model calibration is a special case of the more general Least-Square problems, i.e. given a real m x n matrix A, and a real m-vector b, find a real n-vector x0 that minimises the Euclidean length of Ax - b. Here, m is the number of measurement points, n is the number of parameters to calibrate,
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A is the values of parameter associated variables (log(d), log(heff), etc.) at each measurement point, and b is the vector of measurement values. The vector x0 is the set of parameters found at the end of the calibration. The theoretical mathematical solution of this problem was found by Gauss (around 1830). Further enhancements to the original method were proposed in the 60's in order to solve the numerical instability problem. In 1974, Lawson & Hanson [2] proposed a theoretical solution of the least-square problem with general linear inequality constraints on the vector x0. Atoll implementation is based on this method, which is explained in detail in [1]. References: [1] Björck A. “Numerical Methods for Least Square Problems”, SIAM, 1996. [2] Lawson C.L., Hanson R.J. “Solving Least Squares Problems”, SIAM, 1974.
2.5.3.2 Sample Values for SPM Path Loss Formula Parameters The following tables list some sample orders of magnitudes for the different parameters composing the Standard Propagation Model formula. Minimum
Typical
Maximum
K1
Variable
Variable
Variable
K2
20
44.9
70
K3
-20
5.83
20
K4
0
0.5
0.8
K5
-10
-6.55
0
K6
-1
0
0
K7
-10
0
0
It is recommended to set K6 to 0, and use K7 instead of K6. K6 is a multiplicative coefficient to a value in dB, which means that slight variations in K6 have considerable impact on the path loss. K1 depends on the frequency and the technology. Here are some sample values: Project type
Frequency (MHz)
K1
GSM 900
935
12.5
GSM 1800
1805
22
GSM 1900
1930
23
UMTS
2045a
23.8
1xRTT
1900
23
2300
25.6
2500
26.8
2700
27.9
3300
30.9
3500
31.7
WiMAX
a.
2045 MHz = (2140 + 1950)/2. It is the average of the downlink and uplink centre frequencies of the band.
The above K1 values for WiMAX are extrapolated estimates for different frequency ranges. It is highly recommended to calibrate the SPM using measurement data collected on the field for WiMAX networks before using the SPM for predictions. All K paramaters can be defined by the automatic calibration wizard. Since Kclutter is a constant, its value is strongly dependant on the values given to the losses per clutter classes. From experience, typical losses (in dB) per clutter class are: Dense urban
From 4 to 5
Woodland
From 2 to 3
Urban
0
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Suburban
From -5 to -3
Industrial
From -5 to -3
Open in urban
From -6 to -4
Open
From -12 to -10
Water
From -14 to -12
These values have to be entered only when considering statistical clutter class maps only. The Standard Propagation Model is derived from the Hata formulae, valid for urban environments. The above values are normalized for urban clutter types (0 dB for urban clutter class). Positive values correspond to more dense clutter classes and negative values to less dense clutter classes.
2.5.4 Unmasked Path Loss Calculation You can use the SPM to calculate unmasked path losses. Unmasked path losses are calculated by not taking into account the transmitter antenna patterns, i.e., the attenuation due to the transmitter antenna pattern is not included. Such path losses are useful when using path loss matrices calculated by Atoll with automatic optimisation tools. The instance of the SPM available by default, under the Propagation Models folder in the Modules tab, has the following characteristics: • •
Signature: Type:
{D5701837-B081-11D4-931D-00C04FA05664} Atoll.StdPropagModel.1
You can access these parameters in the Propagation Models table by double-clicking the Propagation Models folder in the Modules tab. To make the SPM calculate path losses excluding the antenna pattern attenuation, you have to change the type of the SPM to: •
Type:
Atoll.StdPropagModelUnmasked.1
However, changing the type only does not invalidate the already calculated path loss matrices, because the signature of the propagation model is still the same. If you want Atoll to recognize that the SPM has changed, and to invalidate the path loss matrices calculated with this model, you have to change the signature of the model as well. The default signature for the SPM that calculates unmasked path loss matrices is: •
Signature:
{EEE060E5-255C-4C1F-B36C-A80D3D972583}
The above signature is a default signature. Atoll automatically creates different signatures for different instances of the same propagation model. Therefore, it is possible to create different instances of the SPM, with different parameter settings, and create unmasked versions of these instances. You can change the signature and type of the original instance of the SPM, but it is recommended to make a copy of the SPM in order not to lose the original SPM parameters. So, you will be able to keep different versions of the SPM, those that calculate path losses with antenna pattern attenuation, and others that calculate path losses without it. The usual process flow of an ACP working on an Atoll document through the API would be to: 1. Backup the storage directory of path loss matrices. 2. Set a different storage directory for calculating and storing unmasked path loss matrices. 3. Select the SPM used, backup it’s signature, and change its signature and type as shown above. 4. Perform optimisation using the path loss matrices calculated by the unmasked version of the SPM. 5. Restore the type and the signature of the SPM. 6. Reset the path loss storage directory to the original one.
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• •
•
•
It is not possible to calibrate the unmasked version of the SPM using measurement data. Using the SPM, you can also calculate the angles of incidence by creating a new instance of the SPM with the following characteristics: Type: Atoll.StdPropagModelIncidence.1 Signature: {659F0B9E-2810-4e59-9F0D-DA9E78E1E64B} The "masked" version of the algorithm has not been changed. It still takes into account Atoll.ini options. However, the "unmasked" version does not take Atoll.ini options into account. It’s highly recommended to use one method (Atoll.ini options) or the other one (new identifier & signature) but not to combine both.
2.6 WLL Propagation Model 2.6.1 WLL Path Loss Formula L model = L FS + F Diff L Diff Where L FS is the free space loss calculated using the formula entered in the model properties, L Diff is the diffraction loss calculated using the 3-obstacle Deygout method, and F Diff is the diffraction multiplying factor defined in the model properties.
2.6.2 Calculations in Atoll Free Space Loss For free space loss calculation, see "Free Space Loss" on page 86. Diffraction Atoll calculates diffraction loss along the transmitter-receiver profile built from DTM and clutter maps. Therefore, losses due to clutter are taken into account in diffraction losses. Atoll takes clutter height information from the clutter heights file if available in the .atl document. Otherwise, it considers average clutter height specified for each clutter class in the clutter classes file description. The Deygout construction (considering 3 obstacles) is used. This method is described under "Diffraction" on page 86. The final diffraction losses are determined by multiplying the diffraction losses calculated using the Deygout method by the Diffraction multiplying factor defined in the model properties. •
Receiver Clearance Define receiver clearance (m) per clutter class when clutter height information is either statistical or semideterministic. Both ground altitude and clutter height are considered along the whole profile except over a specific distance around the receiver (clearance), where Atoll proceeds as if there was only the DTM map (see SPM part). Atoll uses the clearance information to model streets. If the clutter is deterministic, do not define any receiver clearance (m) per clutter class. In this case, clutter height information is accurate enough to be used directly without additional information such as clearance (Atoll can locate streets).
•
Receiver Height Entering receiver height per clutter class enables Atoll to consider the fact that receivers are fixed and located on the roofs.
•
Visibility If the option ‘Line of sight only’ is not selected, Atoll computes Lmodel on each calculation bin using the formula defined above. When selecting the option ‘Line of sight only’, Atoll checks for each calculation bin if the Diffraction loss (as defined in the Diffraction loss: Deygout part) calculated along profile equals 0. • •
In this case, receiver is considered in ‘line of sight’ and Atoll computes Lmodel on each calculation bin using the formula defined above. Otherwise, Atoll considers that Lmodel tends to infinity.
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2.7 ITU-R P.526-5 Propagation Model 2.7.1 ITU 526-5 Path Loss Formula L model = L FS + L Diff Where L FS is the free space loss calculated using the formula entered in the model properties and L Diff is the diffraction loss calculated using the 3-obstacle Deygout method.
2.7.2 Calculations in Atoll Free Space Loss For free space loss calculation, see "Free Space Loss" on page 86. Diffraction Atoll calculates diffraction loss along the transmitter-receiver profile is built from the DTM map. The Deygout construction (considering 3 obstacles), with or without correction, is used. These methods are described under "Diffraction" on page 86.
2.8 ITU-R P.370-7 Propagation Model 2.8.1 ITU 370-7 Path Loss Formula If d1000 km, L model = 1000 If 1 d0, i.e. d > 100 m. For d < 100 m, the path loss has been restricted to the free space path loss with correction factors for operating frequency and receiver height: 4d 4d PL = 20 Log 10 ------------------ + a f – a H R instead of PL = 20 Log 10 ------------------ Where a(f) and a(Hr) have the same definition as given above. Simplifying the above equation, we get, PL = 12.634 + 26 Log 10 f + 20 Log 10 d – a H R , or Lu = 12.634 + 26 Log 10 f + 20 Log 10 d The above equation is not user-modifiable in Atoll except for the coefficient of Log 10 f , i.e. 26. Atoll uses the same coefficient as the one you enter for Log 10 f in Atoll for the case d > d0. You can get the same resulting equation by setting a(hBS) = 2.
2.9.3 Calculations in Atoll The Erceg-Greenstein (SUI) propagation model takes DTM into account between the transmitter and the receiver, and it can also take clutter into account at the receiver location. 1st step: For each pixel in the calculation radius, Atoll determines the clutter bin on which the receiver is located. This clutter bin corresponds to a clutter class. Atoll uses the Erceg-Greenstein (SUI) path loss formula assigned to this clutter class to evaluate path loss. 2nd step: This step depends on whether the ‘Add diffraction loss’ option is selected or not. • •
If the ‘Add diffraction loss’ option is not selected, 1st step gives the final path loss result. If the ‘Add diffraction loss’ option is selected, Atoll proceeds as follows: a. It extracts a geographic profile between the transmitter and the receiver using the radial calculation method. b. It determines the largest obstacle along the profile in accordance with the Deygout method and evaluates losses due to diffraction L Diffraction . For more information on the Deygout method, see "3 Knife-edge Deygout Method" on page 87. The final path loss is the sum of the path loss determined in 1st step and L Diffraction .
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Shadow fading is computed in Atoll independent of the propagation model. For more information on the shadow fading calculation, see "Shadow Fading Model" on page 90.
2.10 ITU-R P.1546-2 Propagation Model This propagation model is based on the P.1546-2 recommendations of the ITU-R. These recommendations extend the P.3707 recommendations, and are suited for operating frequencies from 30 to 3000 MHz. The path loss is calculated by this propagation model with the help of graphs available in the recommendations. The graphs provided in the recommendations represent field (or signal) strength, given in db V m , as a function of distance for: •
Nominal frequencies, f n : 100, 600, and 1000 MHz The graphs provided for 100 MHz are applicable to frequencies from 30 to 300 MHz, those for 600 MHz are applicable to frequencies from 300 to 1000 MHz, and the graphs for 1000 MHz are applicable to frequencies from 1000 to 3000 MHz. The method for interpolation is described in the recommendations (Annex 5, § 6).
•
Transmitter antenna heights, h 1 : 10, 20, 37.5, 75, 150, 300, 600, and 1200 m For any values of h 1 from 10 to 3000 m, an interpolation or extrapolation from the appropriate two curves is used, as described in the recommendations (Annex 5, § 4.1). For h 1 below 10 m, the extrapolation to be applied is given in Annex 5, § 4.2. It is possible for the value of h 1 to be negative, in which case the method is given in Annex 5, § 4.3.
•
Time variability, t : 1, 10, and 50 % The propagation curves represent the field strength values exceeded for 1, 10 and 50 % of time.
•
Receiver antenna height, h 2 : 10 m For land paths, the graphs represent field strength values for a receiver antenna height above ground, equal to the representative height of the clutter around the receiver. The minimum value of the representative height of clutter is 10 m. For sea paths, the graphs represent field strength values for a receiver antenna height of 10 m. For other values of receiver antenna height, a correction is applied according to the environment of the receiver. The method for calculating this correction is given in Annex 5, § 9.
These recommendations are not valid for transmitter-receiver distances less than 1 km or greater than 1000 km. Therefore in Atoll, the path loss between a transmitter and a receiver over less than 1 km is the same as the path loss over 1 km. Similarly, the path loss between a transmitter and a receiver over more than 1000 km is the same as the path loss over 1000 km. Moreover, these recommendations are not valid for transmitter antenna heights less than the average clutter height surrounding the transmitter. • •
The cold sea graphs are used for calculations over warm and cold sea both. The mixture of land and sea paths is not supported by Atoll.
2.10.1 Calculations in Atoll The input to the propagation model are the transmission frequency, transmitter and receiver heights, the distance between the transmitter and the receiver, the precentage of time the field strength values are exceeded, the type of environment (i.e., land or sea), and the clutter at the receiver location. In the following calculations, f is the transmission frequency, d is the transmitter-receiver distance, and t is the percentage of time for which the path loss has to be calculated. The following calculations are performed in Atoll to calculate the path loss using this propagation model.
2.10.1.1 Step 1: Determination of Graphs to be Used First of all, the upper and lower nominal frequencies are determined for any given transmission frequency. The upper and lower nominal frequencies are the nominal frequencies (100, 600, and 2000 MHz) between which the transmission frequency is located, i.e., f n1 f f n2 . Once f n1 and f n1 are known, along with the information about the percentage of time t and the type of path (land or sea), the sets of graphs which will be used for the calculation are also known.
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2.10.1.2 Step 2: Calculation of Maximum Field Strength A field strength must not exceed a maximum value, E Max , which is given by: E Max = E FS = 106.9 – 20 Log d for land paths, and E Max = E FS + E SE = 106.9 – 20 Log d + 2.38 1 – exp – d 8.94 Log 50 t for sea paths. Where E FS is the free space field strength for 1 kW ERP, E SE is an enhancement for sea graphs.
2.10.1.3 Step 3: Determination of Transmitter Antenna Height The transmitter antenna height to be used in the calculation depends on the type and length of the path. •
Land paths h 1 = h eff
•
Sea paths h 1 = Max 1 h a
Here, all antenna heights (i.e., h 1 , h eff , and h a ) are in expressed in m. h a is the antenna height above ground and h eff is the effective height of the transmitter antenna, which is its height over the average level of the ground between distances of 0.2 d and d km from the transmitter in the direction of the receiver.
2.10.1.4 Step 4: Interpolation/Extrapolation of Field Strength The interpolations are performed in series in the same order as described below. The first interpolation/extrapolation is performed over the field strength values, E , from the graphs for transmitter antenna height to determine E h1 . The second interpolation/extrapolation is performed over the interpolated/extrapolated values of E h1 to determine E d . And, the thrid and final interpolation/extrapolation is performed over the interpolated/extrapolated values of E d to determine E f . Step 4.1: Interpolation/Extrapolation of Field Strength for Transmitter Antenna Height If the value of h 1 coincides with one of the eight heights for which the field strength graphs are provided, namely 10, 20, 37.5, 75, 150, 300, 600, and 1200 m, the required field strength is obtained directly from the corresponding graph. Otherwise: •
If 10 m h 1 3000 m The field strength is interpolated or extrapolated from field strengths obtained from two curves using the following equation: Log h 1 h Low E h1 = E Low + E Up – E Low ------------------------------------Log h Up h Low Where h Low = 600 m if h 1 1200 m , otherwise h Low is the nearest nominal effective height below h 1 , h Up = 1200 m if h 1 1200 m , otherwise h Up is the nearest nominal effective height above h 1 , E Low is the field strength value for h Low at the required distance, and E Up is the field strength value for h Up at the required distance.
•
If 0 m h 1 10 m •
For land path if the transmitter-receiver distance is less than the smooth-Earth horizon distance d H h 1 = 4.1 h 1 , i.e., if d 4.1 h 1 , E h1 = E 10 d H 10 + E 10 d – E 10 d H h 1 , or E h1 = E 10 12.9 km + E 10 d – E 10 d H h 1 because d H 10 = 12.9 km
•
For land path if the transmitter-receiver distance is greater than or equal to the smooth-Earth horizon distance d H h 1 = 4.1 h 1 , i.e., if d 4.1 h 1 , E h1 = E 10 d H 10 + d – d H h 1 , or E h1 = E 10 12.9 km + d – d H h 1 because d H 10 = 12.9 km Where E x y is the field strength value read for the transmitter-receiver distance of y from the graph available for the transmitter antenna height of x.
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If in the above equation, d H 10 + d – d H h 1 1000 km even though d 1000 km , the field strength is determined from linear extrapolation for Log (distance) of the graph given by: Log d D Low E h1 = E Low + E Up – E Low -------------------------------------Log D Up D Low Where D Low is penultimate tabulation distance (km), D Up is the final tabulation distance (km), E Low is the field strength value for D Low , and E Up is the field strength value for D Up . •
For sea path, h 1 should not be less than 1 m. This calculation requires the distance at which the path has 0.6 of the first Fresnel zone just unobstructed by the sea surface. This distance is given by: D h1 = D 0.6 f h 1 h 2 = 10 m (km) Df Dh Where D 0.6 = Max 0.001 ----------------- (km) with D f = 0.0000389 f h 1 h 2 (frequency-dependent term), and D f + D h D h = 4.1 h 1 + h 2 (asymptotic term defined by the horizon distance). If d D h1 the 0.6 Fresnel clearance distance for the sea path where the transmitter antenna height is 20 m is also calculated as: D 20 = D 0.6 f h 1 = 20 m h 2 = 10 m (km) Once D h1 and D 20 are known, the field strength for the required distance is given by:
E h1
E Max Log d D h1 = E D + E D – E D ---------------------------------h1 20 h1 Log D 20 D h1 E' 1 – F S + E'' F S
for d D h1 for D h1 d D 20 for d D 20
Where E Max is the maximum field strength at the required distance as calculated in "Step 2: Calculation of Maximum Field Strength" on page 81, E D ED
20
h1
is E Max for d = D h1 ,
Log h1 10 Log h1 10 = E 10 D 20 + E 20 D 20 – E 10 D 20 ------------------------------- , E' = E 10 d + E 20 d – E 10 d ------------------------------- , and Log 20 10 Log 20 10
E'' is the field strength calculated as described for land paths. E 10 y and E 20 y are field strengths interpolated for distance y and h 1 = 10 m and 20 m , respectively, and F S = d – D 20 d . •
If h 1 0 m A correction is applied to the field strength, E h1 , calculated in the above description in order to take into account the diffraction and tropospheric scattering. This correction is the maximum of the diffraction correction,, and tropospheric scattering correction, . C h1 = Max C h1d C h1t Where
C h1d = 6.03 – J
with
2
J = 6.9 + 20 Log – 0.1 + 1 + – 0.1
and
= K eff2 ,
–h1 - , and K is 1.35 for 100 MHz, 3.31 for 600 MHz, 6.00 for 2000 MHz. eff2 = arc tan ----------9000 e 180 d- a = 6370 km - with e = -------------------C h1t = 30 Log ---------------------, (radius of the Earth), and k = 4 3 is the e + eff2 ak effective Earth radius factor for mean refractivity conditions. Step 4.2: Interpolation/Extrapolation of Field Strength for Transmitter-Receiver Distance In the field strength graphs in the recommendations, the field strength is plotted against distance from 1 km to 1000 km. The distance values for which field strengths are tabulated are 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950, 975, 1000. If the transmitter-receiver distance is a value from this list, then interpolation of field strength is not required and the field strength can be directly read from the graphs.
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If the transmitter-receiver distance does not coincide with the list of distances for which the field strengths are accurately available from the graphs, the field strength are linearly interpolated or extrapolated for the logarithm of the distance using the following equation: Log d d Low E d = E Low + E Up – E Low ------------------------------------Log d Up d Low Where d Low is the lower value of the nearest tabulated distance to d , d Up is the higher value of the nearest tabulated distance to d , E Low is the field strength value for d Low , and E Up is the field strength value for d Up . Step 4.3: Interpolation/Extrapolation of Field Strength for Transmission Frequency The field strength at the transmission frequency is interpolated from the graphs available for the upper and lower nominal frequencies as follows: Log f f Low E f = E Low + E Up – E Low ----------------------------------Log f Up f Low Where f Low is the lower nominal frequency (100 MHz if f < 600 MHz, 600 MHz otherwise), f Up is the higher nominal frequency (600 MHz if f < 600 MHz, 2000 MHz otherwise), E Low is the field strength value for f Low , and E Up is the field strength value for f Up . In the case of transmission frequencies below 100 MHz or above 2000 MHz, the field strength values are extrapolated from the two nearer nominal frequency values. The above equation is used for all land paths and sea paths.
2.10.1.5 Step 5: Calculation of Correction Factors Step 5.1: Correction for Receiver Antenna Height The receiver antenna height correction depends on the type of path and clutter in which the receiver is located. The field strength values given by the graphs for land paths are for a reference receiver antenna at a height, R (m), representative of the height of the clutter surrounding the receiver, subject to a minimum height value of 10 m. Examples of reference heights are 20 m for an urban area, 30 m for a dense urban area, and 10 m for a suburban area. For sea paths the notional value of R is 10 m. For land paths, the elevation angle of the arriving ray is taken into account by calculating a modified representative clutter 1000 d R – 15 h 1 height R' , given by R' = Max 1 ----------------------------------------------------------. 1000 d – 15 Note that for h 1 6.5 d + R , R' R . The different correction factors are calculated as follows: •
For land path in urban and suburban zones 6.03 – J for h 2 R' C Receiver = h 3.2 + 6.2 Log f Log ----2- for h 2 R' R' R' – h 2 2 With J = 6.9 + 20 Log – 0.1 + 1 + – 0.1 and = 0.0108 f R' – h 2 arc tan --------------- . 27 10 If R' 10 m , C Receiver is reduced by 3.2 + 6.2 Log f Log ------ . R'
•
For land path other zones h C Receiver = 3.2 + 6.2 Log f Log -----2- 10
•
For sea path d 10 and d h2 are determined as distances at which at which the path has 0.6 of the first Fresnel zone just unobstructed by the sea surface with h 2 = 10 m
and variable h 2 , respectively. These distances are given by
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D f D h - as d 10 = D 0.6 f h 1 h 2 = 10 m and d h2 = D 0.6 f h 1 h 2 (km), respectively. Here D 0.6 = Max 0.001 --------------- D f + D h explained earlier. •
h2 If h 2 10 m , C Receiver = 3.2 + 6.2 Log f Log ------ 10
•
h2 If h 2 10 m and d d 10 , C Receiver = 3.2 + 6.2 Log f Log ------ 10
•
If h 2 10 m and d d 10 and d d h2 , C Receiver = 0
•
Log d d h2 h2 If h 2 10 m and d d 10 and d d h2 , C Receiver = 3.2 + 6.2 Log f Log ------ ---------------------------------- 10 Log d 10 d h2
Step 5.2: Correction for Short Urban/Suburban Paths This correction is only applied when the path loss is to be calculated over land paths, over a transmitter-receiver distance less than 15 km, in urban and suburban zones. This correction takes into account the presence of buildings in these zones. The buildings are assumed to be of uniform height. The correction represents a reduction in the field strength due to building clutter. It is added to the field strength and is given by: C Building = – 3.3 Log f 1 – 0.85 Log d 1 – 0.46 Log 1 + h a – R Where h a is the antenna height above the ground, and R is the clutter height of the clutter class where the receiver is located. This correction is only applied when d 15 km and h 1 – R 150 m . Step 5.3: Correction for Receiver Clearance Angle This correction is only applied when the path loss is to be calculated over land paths, and over a transmitter-receiver distance less than 16 km. This correction gives more precise field strength prediction over small reception areas. The correction is added to the field strength and is given by: C Clearance = J ' – J 2
Where J = 6.9 + 20 Log – 0.1 + 1 + – 0.1 , ' = 0.036 f , and = 0.065 Clearance f Clearance is the clearance angle in degrees determined from: •
•
: The elevation angle of the line from the receiver which just clears all terrain obstructions in the direction of the transmitter over a distance of up to 16 km but not going beyond the transmitter. h 1S – h 2S - . Ref : The reference angle, Ref = arc tan ------------------- 1000 d Where h 1S and h 2S are the heights of the transmitter and the receiver above sea level, respectively.
2.10.1.6 Step 6: Calculation of Path Loss First, the final field strength is calculated from the interpolated/extrapolated field strength, E f , by applying the corrections calculated earlier. The calculated field strength is given by: E Calc = E f + C Receiver + C Building + C Clearance The resulting field strength is given by E = Min E Calc E Max , from which the path loss (basic transmission loss, L B ) is calculated as follows: L B = 139 – E + 20 Log f
2.11 Sakagami Extended Propagation Model The Sakagami extended propagation model is based on the simplification of the extended Sakagami-Kuboi propagation model. The Sakagami extended propagation model is valid for frequencies above 3 GHz. Therefore, it is only available in WiMAX documents by default.
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The Sakagami-Kuboi propagation model requires detailed information about the environment, such as widths of the streets where the receiver is located, the angles formed by the street axes and the directions of the incident waves, heights of the buildings close to the receiver, etc. The path loss formula for the Sakagami-Kuboi propagation model is [1]: H 2 L Model = 100 – 7.1 Log W + 0.023 + 1.4 Log h s + 6.1 Log H 1 – 24.37 – 3.7 -------- Log h b + h b0 43.2 – 3.1 Log h b Log d + 20 Log f + e
13 Log f – 3.23
Where, • • • • • • • • •
W is the width (in meters) of the streets where the receiver is located is the angle (in degrees) formed by the street axes and the direction of the incident wave hs is the height (in meters) of the buildings close to the receiver H1 is the average height (in meters) of the buildings close to the receiver hb is the height (in meters) of the transmitter antenna with respect to the observer hb0 is the height (in meters) of the transmitter antenna with respect to the ground level H is the average height (in meters) of the buildings close to the base station d is the separation (in kilometres) between the transmitter and the receiver f is the frequency (in MHz)
The Sakagami-Kuboi propagation model is valid for: 5m
DAS > MCS > CS.
When the calculations are based on C/I and C/(I+N): • •
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Atoll calculates the carrier-to-interference ratio for all the GPRS/EDGE TBC transmitters but takes into account all the TBC transmitters (GSM and GPRS/EDGE) to evaluate the interference. The reception thresholds given for signal level C are internally converted to C/N thresholds ( N is the thermal noise defined in the document database at -121 dBm by default) in order to be indexed by C/(I+N) values. C/I thresholds are also indexed by the C/(I+N) value.
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The selection of coding schemes is mainly based on the radio conditions mentionned above. Nevertheless, you can optionally define some specific coding scheme graphs accoding to a specific hopping mode, mobility type, frequency band and MAL. As an example, you can model the gain due to longer MALs in coding scheme selection. For more information on interference (I) calculation, see "DL Carrier-to-Interference Ratio Calculation" on page 131.
3.3.1 Coding Scheme Selection and Throughput Calculation Without Ideal Link Adaptation 3.3.1.1 Calculations Based on C Coding Scheme Selection Atoll selects a coding scheme, cs, from among the coding schemes available in the GPRS/EDGE configuration, such that: For each TRX type, tt, cs = Lowest CS
Txi Txi P rec TRX – P Backoff TRX Reception Threshold CS
The selected coding scheme, cs, is the coding scheme with the lowest coding scheme number from the lowest priority coding scheme list. Throughput Calculation Once the coding scheme cs is selected, Atoll reads the corresponding throughput value for the received signal level from the Throughput=f(C) graph associated with cs.
3.3.1.2 Calculations Based on C/I Coding Scheme Selection Atoll selects two coding schemes from among the coding schemes available in the GPRS/EDGE configuration, such that: For each TRX type, tt, cs C = Lowest CS
And, cs C I
= Lowest CS
Txi Txi P rec TRX – P Backoff TRX Reception Threshold CS
Txi Txi P TRX – P TRX rec Backoff C ------------------------------------------------------------------------- --- Threshold I CS I
csC is the coding scheme determined from the signal level, and csC/I is the coding scheme determined from the C/I level. Both coding schemes are the coding schemes with the lowest coding scheme number from the lowest priority coding scheme list. The selected coding scheme, cs, is the coding scheme with the lower coding scheme number among csC and csC/I: cs = Min cs C cs C I . Throughput Calculation Based on the Worst Case Between C and C/I For the coding scheme csC determined above, a throughput value, TPC, corresponding to the signal level is determined from the TP = f(C) graph. For the coding scheme csC/I determined above, a throughput value, TPC/I, corresponding to the C/I is determined from the TP = f(C/I) graph. The resulting throughput TP is the lower of the two values, TPC and TPC/I: TP = Min TP C TP C I .
3.3.1.3 Calculations Based on C/(I+N) Coding Scheme Selection Atoll selects two coding schemes from among the coding schemes available in the GPRS/EDGE configuration, such that:
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For each TRX type, tt, cs C N = Lowest CS
And, cs C I + N
= Lowest CS
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Txi Txi P TRX – P TRX rec Backoff C ------------------------------------------------------------------------- ----------- Threshold I + N CS N
Txi Txi P rec TRX – P Backoff TRX C ------------------------------------------------------------------------- --------- I + N Threshold CS I+N
csC/N is the coding scheme determined from the C/N, and csC/(I+N) is the coding scheme determined from the C/(I+N) level. Both coding schemes are the coding schemes with the lowest coding scheme numbers from the lowest priority coding scheme list. The selected coding scheme, cs, is the coding scheme with the higher coding scheme number among csC/N and csC/(I+N): cs = Max cs C N cs C I + N . Throughput Calculation Based on Interpolation Between C/N and C/(I+N) For the coding scheme csC/N determined above, the TP = f(C) graph is internally converted to TP = f(C/N) graph. A throughput value, TPC/N, corresponding to the C/(I+N) is determined from the TP = f(C/N) graph. For the coding scheme csC/(I+N) determined above, the TP = f(C/I) graph is internally converted to TP = f(C/(I+N)) graph. A throughput value, TPC/(I+N), corresponding to the C/(I+N) is determined from the TP = f(C/(I+N)) graph. The final throughput is computed by interpolating between the throughput values obtained from these two graphs. The throughput interpolation method consists in interpolating TPC/N and TPC/(I+N) according to the respective weights of I and N values. The resulting throughput TP is given by: TP = TP C N + 1 – TP C I + N pN - , pN is the thermal noise power (value in Watts), and p(I+N) is the interferences + thermal noise power (value = ------------------pI + N in Watts).
3.3.2 Coding Scheme Selection and Throughput Calculation With Ideal Link Adaptation 3.3.2.1 Calculations Based on C Throughput Calculation For the received signal level, and coding schemes whose reception thresholds are lower than the received signal level, Atoll determines the highest throughput from the TP=f C graphs available in the GPRS/EDGE configuration. Txi
Txi
TP C = Highest TP=f C = P rec TRX – P Backoff TRX
CS
Txi Txi P rec TRX – P Backoff TRX Reception Threshold CS
Coding Scheme Selection The selected coding scheme, cs, is the one corresponding to the highest throughput calculated above. If there are more than one coding schemes providing the highest throughput at the pixel, the selected coding scheme, cs, is the one with the lowest coding scheme number from the lowest priority coding scheme list.
3.3.2.2 Calculations Based on C/I Throughput Calculation Based on Worst Case Between C and C/I For the received signal level, and coding schemes whose reception thresholds are lower than the received signal level, Atoll determines the highest throughput from the TP=f C graphs available in the GPRS/EDGE configuration.
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Txi
Txi
TP C = Highest TP=f C = P rec TRX – P Backoff TRX
CS
P
Txi Txi TRX – P TRX Reception Threshold rec Backoff CS
For the received C/I, and coding schemes whose C/I thresholds are lower than the received C/I, Atoll determines the highest throughput from the TP=f C I graphs available in the GPRS/EDGE configuration.
TP C I
Txi Txi P rec TRX – P Backoff TRX = Highest TP=f C I = ---------------------------------------------------------------- CS I
Txi Txi P rec TRX – P Backoff TRX C ------------------------------------------------------------------------- --- Threshold I CS I
The resulting throughput TP is the lower of the two values, TPC and TPC/I. TP = Min TP C TP C I Coding Scheme Selection The selected coding scheme, cs, is the one corresponding to the lower of the two highest throughputs calculated above. If there are more than one coding schemes providing the highest throughputs at the pixel, the selected coding scheme, cs, is the one with the lowest coding scheme number from the lowest priority coding scheme list.
3.3.2.3 Calculations Based on C/(I+N) Throughput Calculation Based on Interpolation Between C/N and C/(I+N) Atoll internally converts the TP = f(C) graphs into TP = f(C/N) graphs. For the received C/(I+N), and coding schemes whose C/ (I+N) thresholds are lower than the received C/(I+N), Atoll determines the highest throughput from the TP = f(C/N) graphs available in the GPRS/EDGE configuration.
TP C N
Txi Txi P rec TRX – P Backoff TRX C = Highest TP=f --- = ---------------------------------------------------------------- CS I+N N
Txi Txi P rec TRX – P Backoff TRX C ------------------------------------------------------------------------- ----------- Threshold I + N CS I+N
Atoll internally converts the TP = f(C/I) graphs into TP = f(C/(I+N)) graphs. For the received C/(I+N), and coding schemes whose C/(I+N) thresholds are lower than the received C/(I+N), Atoll determines the highest throughput from the TP = f(C/(I+N)) graphs available in the GPRS/EDGE configuration.
TP C I + N
Txi Txi P rec TRX – P Backoff TRX C = Highest TP=f ----------- = ---------------------------------------------------------------- CS I+N I+N
Txi Txi P rec TRX – P Backoff TRX C ------------------------------------------------------------------------- ----------- Threshold I + N CS I+N
The final throughput is computed by interpolating between the throughput values obtained from these two graphs. The throughput interpolation method consists in interpolating TPC/N and TPC/(I+N) according to the respective weights of I and N values. The resulting throughput TP is given by: TP = TP C N + 1 – TP C I + N pN = ------------------, pN is the thermal noise power (value in Watts), and p(I+N) is the interferences + thermal noise power (value pI + N in Watts). Coding Scheme Selection The selected coding scheme, cs, is the one corresponding to the higher of the two highest throughputs calculated above. If there are more than one coding schemes providing the highest throughputs at the pixel, the selected coding scheme, cs, is the one with the highest coding scheme number from the highest priority coding scheme list.
3.3.3 Application Throughput Calculation Application throughput is calculated from the effective RLC throughput as follows: SF- – TP TP Application = TP RLC MAC -------Offset 100
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TP RLC MAC is the effective RLC throughput, and TP Offset and SF are the throughput offset (kbps) and the throughput scaling factor (%) defined for the selected service.
3.3.4 BLER Calculation Block error rate is calculated as follows: TP --------------- If TP TP MAX BLER = TP MAX 0 If TP TP MAX TP is the throughput per timeslot calculated for a pixel and TPMAX is the maximum throughput per timeslot read from the GPRS/EDGE configuration used for the calculations.
3.3.5 GPRS/EDGE Coverage Predictions Two GPRS/EDGE coverage predictions are available: •
Coverage by GPRS/EDGE Coding Scheme: Shows the areas various coding schemes are available.
•
Packet Throughput and Quality Analysis: Shows the throughputs corresponding to the coding schemes available.
For each TBC transmitter, Txi, Atoll calculates the selected parameter on each pixel inside the Txi calculation area. In other words, each pixel inside the Txi calculation area is considered a probe (non-interfering) receiver. Coverage prediction parameters to be set are: • • •
The coverage conditions in order to determine the service area of each TBC transmitter, The interference conditions to meet for a pixel to be covered, and The display settings to select the displayed parameter and its shading levels.
The thermal noise (N = -121 dBm, by default) is used in the calculations if the coverage prediction is based on C/(I+N). This value can be modified by the user.
3.3.5.1 Service Area Determination Atoll uses parameters entered in the Condition tab of the coverage prediction properties dialogue to determine the areas coverage will be displayed. We can distinguish eight cases as below. Let us assume that: • • •
3.3.5.1.1
Each transmitter, Txi, belongs to a Hierarchical Cell Structure (HCS) layer, k, with a defined priority and a defined reception threshold. Each transmitter, Txi, is GPRS/EDGE-capable. No max range is set.
All Servers The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec tt
3.3.5.1.2
Best Signal Level and a Margin The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec tt Txi Txj And P rec tt Best P rec tt – M ji
M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
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If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
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Second Best Signal Level and a Margin The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec tt nd
Txi Txj And P rec tt 2 Best P rec tt – M ji
M is the specified margin (dB). The 2nd Best function considers the second highest value from a list of values. • • •
3.3.5.1.4
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the second highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the second highest or within a 2 dB margin from the second highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 3rd best servers.
Best Signal Level per HCS Layer and a Margin For each HCS layer, k, the service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec tt Txi Txj And P rec BCCH Best P rec BCCH – M ji
M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
3.3.5.1.5
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
Second Best Signal Level per HCS Layer and a Margin For each HCS layer, k, the service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec tt nd
Txi Txj And P rec BCCH 2 Best P rec BCCH – M ji
M is the specified margin (dB). The 2nd Best function considers the second highest value from a list of values. • • •
3.3.5.1.6
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the second highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the second highest or within a 2 dB margin from the second highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 3rd best servers.
HCS Servers and a Margin The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec tt Txi Txj And P rec BCCH Best P rec BCCH – M ji Txi
And the received P rec tt exceeds the reception threshold defined per HCS layer. M is the specified margin (dB). The Best function considers the highest value from a list of values. • •
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest.
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If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
Highest Priority HCS Server and a Margin The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec tt Txi Txj And P rec BCCH Best P rec BCCH – M ji
And Txi belongs to the HCS layer with the highest priority. The highest priority is defined by the priority field (0: lowest). Txi
And the received P rec tt exceeds the reception threshold defined per HCS layer. In the case two layers have the same priority, the traffic is served by the transmitter for which the difference between the received signal strength and the HCS threshold is the highest. The way the competition is managed between layers with the same priority can be modified. For more information, see the Administrator Manual. M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
3.3.5.1.8
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
Best Idle Mode Reselection Criterion (C2) Such type of coverage is useful: • •
To compare idle and dedicated mode best servers for voice traffic Display the GPRS/EDGE best server map (based on GSM idle mode)
The path loss criterion C1 used for cell selection and reselection is defined by: Txi
C1 = P rec BCCH – MinimumThreshold BCCH The path loss criterion (GSM03.22) is satisfied if C1 0 . The reselection criterion C2 is used for cell reselection only and is defined by: C2 = C1 + CELL_RESELECT_OFFSET CELL_RESELECT_OFFSET is the Cell Reselect Offset defined for the transmitter. The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec BCCH And C2
Txi
Txj BCCH = Best C2 BCCH j
The Best function considers the highest value from a list of values. On each pixel, the transmitter with the highest C2 value is kept. It corresponds to the best server in idle mode. C2 is defined as an integer in the 3GPP specifications, therefore, the C2 values in the above calculations are rounded down to the nearest integer.
3.3.5.2 Coverage Display 3.3.5.2.1
Coverage Resolution The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information).
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3.3.5.2.2
Display Types It is possible to display the coverage predictions with colours depending on criteria such as: Coverage by GPRS/EDGE Coding Scheme: Coding Schemes Only the pixels with a coding scheme assigned are coloured. The pixel colour depends on the assigned coding scheme. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as transmitter coverage areas. Each layer shows the coding schemes available in the transmitter coverage area. Coverage by GPRS/EDGE Coding Scheme: Max Coding Schemes On each pixel, Atoll chooses the highest coding scheme available from the TRXs of different transmitters covering that pixel. Only the pixels with a coding scheme assigned are coloured. The pixel colour depends on the assigned coding scheme. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as possible coding schemes. Each layer shows the areas a given coding scheme can be used. Packet Throughput and Quality Analysis: Effective RLC Throughput/Timeslot (kbps) A pixel of the coverage area is coloured if the calculated effective RLC throughput per timeslot from any transmitter covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the effective RLC throughput per timeslot. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as transmitter coverage areas and throughput display thresholds. Each layer shows the effective RLC throughput that a transmitter can provide on one timeslot. Packet Throughput and Quality Analysis: Max Effective RLC Throughput/Timeslot (kbps) A pixel of the coverage area is coloured if the calculated highest effective RLC throughput per timeslot from any transmitter covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the highest effective RLC throughput per timeslot. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as throughput display thresholds. Each layer shows the best effective RLC throughput that any transmitter can provide on one timeslot. Packet Throughput and Quality Analysis: Average Effective RLC Throughput/Timeslot (kbps) A pixel of the coverage area is coloured if the calculated average effective RLC throughput per timeslot from all the transmitters covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the average effective RLC throughput per timeslot. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as throughput display thresholds. Each layer shows the average effective RLC throughput that all the transmitters can provide on one timeslot. Packet Throughput and Quality Analysis: Application Throughput/Timeslot (kbps) A pixel of the coverage area is coloured if the calculated application throughput per timeslot from any transmitter covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the application throughput per timeslot. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as transmitter coverage areas and throughput display thresholds. Each layer shows the application throughput that a transmitter can provide on one timeslot. Packet Throughput and Quality Analysis: Best Application Throughput/Timeslot (kbps) A pixel of the coverage area is coloured if the calculated highest application throughput per timeslot from any transmitter covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the highest application throughput per timeslot. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as throughput display thresholds. Each layer shows the best application throughput that any transmitter can provide on one timeslot. Packet Throughput and Quality Analysis: Average Application Throughput/Timeslot (kbps) A pixel of the coverage area is coloured if the calculated average application throughput per timeslot from all the transmitters covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the average application throughput per timeslot. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as throughput display thresholds. Each layer shows the average application throughput that all the transmitters can provide on one timeslot. Packet Throughput and Quality Analysis: Effective RLC Throughput (kbps) A pixel of the coverage area is coloured if the calculated effective RLC throughput from any transmitter covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the effective RLC for all the timeslots supported by the
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selected terminal type (Number of Simultaneous Carriers x Number of DL Timeslots). The number of DL timeslots is the minimum between the number of DL timeslots defined in the selected terminal and service. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as transmitter coverage areas and throughput display thresholds. Each layer shows the application throughput that a transmitter can provide on all available timeslots in the terminal. Packet Throughput and Quality Analysis: Max Effective RLC Throughput (kbps) A pixel of the coverage area is coloured if the calculated highest effective RLC throughput from any transmitter covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the highest effective RLC throughput for all the timeslots supported by the selected terminal type (Number of Simultaneous Carriers x Number of DL Timeslots). The number of DL timeslots is the minimum between the number of DL timeslots defined in the selected terminal and service. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as throughput display thresholds. Each layer shows the highest effective RLC throughput that any transmitter can provide on all available timeslots in the terminal. Packet Throughput and Quality Analysis: Average Effective RLC Throughput (kbps) A pixel of the coverage area is coloured if the calculated average effective RLC throughput from all the transmitters covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the average effective RLC throughput for all the timeslots supported by the selected terminal type (Number of Simultaneous Carriers x Number of DL Timeslots). The number of DL timeslots is the minimum between the number of DL timeslots defined in the selected terminal and service. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as throughput display thresholds. Each layer shows the average effective RLC throughput that all the transmitters can provide on all available timeslots in the terminal. Packet Throughput and Quality Analysis: Application Throughput (kbps) A pixel of the coverage area is coloured if the calculated application throughput from any transmitter covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the application throughput for all the timeslots supported by the selected terminal type (Number of Simultaneous Carriers x Number of DL Timeslots). The number of DL timeslots is the minimum between the number of DL timeslots defined in the selected terminal and service. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as transmitter coverage areas and throughput display thresholds. Each layer shows the application throughput that a transmitter can provide on all available timeslots in the terminal. Packet Throughput and Quality Analysis: Max Application Throughput (kbps) A pixel of the coverage area is coloured if the calculated highest application throughput from any transmitter covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the highest application throughput for all the timeslots supported by the selected terminal type (Number of Simultaneous Carriers x Number of DL Timeslots). The number of DL timeslots is the minimum between the number of DL timeslots defined in the selected terminal and service. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as throughput display thresholds. Each layer shows the highest application throughput that any transmitter can provide on all available timeslots in the terminal. Packet Throughput and Quality Analysis: Average Application Throughput (kbps) A pixel of the coverage area is coloured if the calculated average application throughput from all the transmitters covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the average application throughput for all the timeslots supported by the selected terminal type (Number of Simultaneous Carriers x Number of DL Timeslots). The number of DL timeslots is the minimum between the number of DL timeslots defined in the selected terminal and service. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as throughput display thresholds. Each layer shows the average application throughput that all the transmitters can provide on all available timeslots in the terminal. Packet Throughput and Quality Analysis: Throughput per User (kbps) A pixel of the coverage area is coloured if the calculated throughput per user from any transmitter covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the throughput per user for all the timeslots supported by the selected terminal type (Number of Simultaneous Carriers x Number of DL Timeslots). The number of DL timeslots is the minimum between the number of DL timeslots defined in the selected terminal and service. The throughput per user is calculated by applying the throughput reduction factor, determined using the selected dimensioning model, to the application throughput. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as transmitter coverage areas and throughput display thresholds. Each layer shows the throughput per user that a transmitter can provide on all available timeslots in the terminal.
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Packet Throughput and Quality Analysis: Max Throughput per User (kbps) A pixel of the coverage area is coloured if the calculated highest throughput per user from any transmitter covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the highest throughput per user for all the timeslots supported by the selected terminal type (Number of Simultaneous Carriers x Number of DL Timeslots). The number of DL timeslots is the minimum between the number of DL timeslots defined in the selected terminal and service. The throughput per user is calculated by applying the throughput reduction factor, determined using the selected dimensioning model, to the application throughput. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as throughput display thresholds. Each layer shows the highest throughput per user that any transmitter can provide on all available timeslots in the terminal. Packet Throughput and Quality Analysis: Average Throughput per User (kbps) A pixel of the coverage area is coloured if the calculated average throughput per user from all the transmitters covering that pixel exceeds the defined minimum threshold. The pixel colour depends on the average throughput per user for all the timeslots supported by the selected terminal type (Number of Simultaneous Carriers x Number of DL Timeslots). The number of DL timeslots is the minimum between the number of DL timeslots defined in the selected terminal and service. The throughput per user is calculated by applying the throughput reduction factor, determined using the selected dimensioning model, to the application throughput. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as throughput display thresholds. Each layer shows the average throughput per user that all the transmitters can provide on all available timeslots in the terminal. Packet Throughput and Quality Analysis: BLER (%) A pixel of the coverage area is coloured if the calculated BLER from any transmitter exceeds the defined minimum threshold. The pixel colour depends on the BLER. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as transmitter coverage areas and BLER display thresholds. Each layer shows the BLERs that the covered pixels experience on one timeslot. Packet Throughput and Quality Analysis: Max BLER (%) A pixel of the coverage area is coloured if the calculated highest BLER from all the transmitters exceeds the defined minimum threshold. The pixel colour depends on the BLER. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as BLER display thresholds. Each layer shows the BLER that the covered pixels experience on one timeslot.
3.4 Codec Mode Selection and CQI Calculations Atoll supports FR, HR, EFR, and AMR codec modes. A codec configuration contains codec mode adaptation thresholds and quality graphs for circuit quality indicators. Atoll has the following circuit quality indicators included by default: • •
•
FER or Frame Erasure Rate: The number of frames in error divided by the total number of frames. These frames are usually discarded, in which case this can be called the Frame Erasure Rate. BER or Bit Error Rate: BER is a measurement of the raw bit error rate in reception before the decoding process begins. Any factor that impacts the decoding performance, such as frequency hopping, will impact the correlation between BER and FER, or the perceived end-user voice quality. MOS or Mean Opinion Score: Voice quality can be quantified using mean opinion score (MOS). MOS values can only be measured in a test laboratory environment. MOS values range from 1 (bad) to 5 (excellent). Different voice codecs have slightly different FER to MOS correlation since the smaller the voice codec bit rate is, the more sensitive it becomes to frame erasures.
The default codec configurations in Atoll include default FER, BER, and MOS quality graphs with respect to the carrier to interference ratio, and codec mode adaptation thresholds (calculated from the FER vs. C/I graphs for all codec modes at 5 % FER).
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Figure 3.1: FER vs. C/I Graphs
Figure 3.2: BER vs. C/I Graphs
Figure 3.3: MOS vs. C/I Graphs
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The graphs are based on: [1] T. Halonen, J. Romero, J. Melero; GSM, GPRS and EDGE performance – Evolution towards 3G/UMTS, John Wiley and Sons Ltd. [2] J. Wigard, P. Mogensen; A simple mapping from C/I to FER and BER for a GSM type of air interface. [3] 3GPP Specifications TR 26.975 V6.0.0; Performance characterization of the Adaptive Multi-Rate (AMR) speech codec (Release 6)
3.4.1 Circuit Quality Indicator Calculations Circuit quality indicator calculations include codec mode selection and CQI calculation. Codec modes may be selected using ideal link adaptation or without it. Once codec modes have been selected, CQI corresponding to these codec modes are determined from the look-up tables. The following sections describe the two categories of calculations, i.e., with and without ideal link adaptations. Ideal link adaptation implies that the selected codec mode corresponds to the best value of the reference CQI under the given radio conditions. Without ideal link adaptation, the codec mode is selected based on the codec adaptation thresholds. CQI calculations may be based on C/N or on C/(I+N). For calculating the noise, either the noise figure defined for the calculations or that of the selected terminal type is used. Different codec configurations may be defined for transmitter and terminals. In this case, Atoll only selects the coding schemes that are common in the two, and gives priority to the thresholds defined in the terminal configuration. If no terminal type is defined for the calculation, or if the terminal type does not have any codec configuration assigned to it, Atoll only uses the codec configuration of the transmitter. If the transmitter does not have any codec configuration assigned to it, no codec mode selection and CQI calculation is carried out. If more than one codec modes satisfy the C/N or C/I conditions, Atoll selects the higher priority codec mode. In the following calculations, we assume that: Txi
•
P rec TRX is the signal level received from the selected TRX type (tt) or on all the TRXs of Txi on each pixel of the Txi
• •
coverage area, CM is the set of all available codec modes, Adaptation Threshold CM are the values of adaptation thresholds for the codec modes available in the codec configuration, The computed noise N is compared to the codec configuration reference noise N Ref . If the values are the same, the defined graphs are used as is, otherwise the graphs are downshifted by the difference N – N Ref .
When the calculations are based on C/(I+N): •
Atoll calculates the carrier-to-interference ratio for all the TBC transmitters with codec configurations assigned, but takes into account all the TBC transmitters (with and without codec configurations) to evaluate the interference. The selection of codec modes is mainly based on the radio conditions mentionned above. Nevertheless, you can optionally define some specific codec mode graphs accoding to a specific hopping mode, mobility type, frequency band and MAL. As an example, you can model the gain due to longer MALs in codec mode selection.
For more information on interference (I) calculation, see "DL Carrier-to-Interference Ratio Calculation" on page 131. Ideal link adaptation for circuit quality indicator studies is defined at the codec configuration level. If the ideal link adaptation option is checked, Atoll will select the codec mode, for the transmitter under study, according to the codec quality graphs (CQI = f(C/N) and CQI = f(C/I)) related to the defined reference CQI, which may be different from the CQI being calculated. Otherwise, Atoll will use the adaptation thresholds defined in the Adaptation Thresholds tab to determine the codec mode to be used in the studies.
3.4.2 CQI Calculation Without Ideal Link Adaptation 3.4.2.1 Calculations Based on C/N Atoll selects the highest priority codec mode, cm, from among the codec modes available in the codec configuration:
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For each TRX type, tt, cm = Highest Priority CM
Txi P TRX rec --------------------------- Adaptation Threshold CM N
Txi
P rec TRX For ------------------------ , Atoll determines the CQI from the CQI=f(C/N) graph associated to the selected codec mode, cm. N
3.4.2.2 Calculations Based on C/(I+N) Atoll selects the highest priority codec mode, cm, from among the codec modes available in the codec configuration: For each TRX type, tt, cm = Highest Priority CM
Txi P rec TRX --------------------------- Adaptation Threshold CM I+N
Txi
P rec TRX - , Atoll determines the CQI from the CQI=f(C/I) graph associated to the selected codec mode, cm. For ----------------------I+N
3.4.3 CQI Calculation With Ideal Link Adaptation 3.4.3.1 Calculations Based on C/N Ideal link adaptation is used by a codec configuration according to a defined reference CQI (MOS by default). Atoll calculates signal level received from Txi on each pixel of Txi coverage area and converts it into C/N values as described earlier. Then, Atoll filters all the codec modes that satisfy the C/N criterion (defined by the CQI = f(C/N) graphs for the reference CQI) and are common between the transmitter and the terminal type codec configuration. The selected codec mode among these filtered codec modes will be, For each TRX type, tt, cm = Highest Priority CM Or, cm = Highest Priority CM
, for MOS Txi P TRX C rec CQI Ref = Highest CQI=f ---= --------------------------- N N tot
, for BER and FER Txi P TRX C rec CQI Ref = Lowest CQI=f ---= --------------------------- N N tot
, cm is the codec mode with the highest priority among the set of codec modes CM for which the reference CQI gives the Txi
P rec TRX - . highest or the lowest value at the received C/N level, ----------------------N tot If more than one codec mode graphs give the same value for reference CQI, then Atoll selects the codec mode with the highest priority. From the CQI = f(C/N) graph associated to the selected codec mode cm, Atoll evaluates the CQI for which the study was Txi
P rec TRX performed corresponding to ------------------------ for the selected codec mode. N tot
3.4.3.2 Calculations Based on C/(I+N) Ideal link adaptation is used by a codec configuration according to a defined reference CQI (MOS by default). Atoll calculates the C/I level received from the transmitter on each pixel of Txi coverage area, for each TRX and converts it into C/(I+N). Then, Atoll filters all the codec modes that satisfy the C/(I+N) criteria (defined by the CQI = f(C/I) graphs for the reference CQI) and are common between the transmitter and the terminal type codec configuration. The selected codec mode among these filtered codec modes will be,
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For each TRX type, tt, cm = Highest Priority CM Or, cm = Highest Priority CM
, for MOS P Txi TRX rec C CQI = Highest CQI=f --- = --------------------------- Ref I I+N tot
, for BER and FER Txi P TRX C rec CQI Ref = Lowest CQI=f --- = --------------------------- I I+N tot
, cm is the codec mode with the highest priority among the set of codec modes CM for which the reference CQI gives the Txi
P rec TRX -. highest or the lowest value at the received C/(I+N) level, ----------------------I + N tot If more than one codec mode graphs give the same value for reference CQI, then Atoll selects the codec mode with the highest priority. From the CQI = f(C/I) graph associated to the selected codec mode cm (indexed with the C/(I+N) values), Atoll evaluates the Txi
P rec TRX - for the selected codec mode. CQI for which the study was performed corresponding to ----------------------I + N tot
3.4.4 Circuit Quality Indicators Coverage Predictions The Circuit Quality Indicators coverage predictions show the areas BER, FER, and MOS values in the transmitter coverage areas. For each TBC transmitter, Txi, Atoll calculates the selected parameter on each pixel inside the Txi calculation area. In other words, each pixel inside the Txi calculation area is considered a probe (non-interfering) receiver. Coverage prediction parameters to be set are: • • •
The coverage conditions in order to determine the service area of each TBC transmitter, The interference and quality indicator conditions to meet for a pixel to be covered, and The display settings to select the displayed parameter and its shading levels.
The thermal noise (N = -121 dBm, by default) is used in the calculations if the coverage prediction is based on C/(I+N). This value can be modified by the user.
3.4.4.1 Service Area Determination Atoll uses parameters entered in the Condition tab of the coverage prediction properties dialogue to determine the areas coverage will be displayed. We can distinguish seven cases as below. Let us assume that: • • •
3.4.4.1.1
Each transmitter, Txi, belongs to a Hierarchical Cell Structure (HCS) layer, k, with a defined priority and a defined reception threshold. Each transmitter, Txi, has a codec configuration assigned. No max range is set.
All Servers The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec BCCH
3.4.4.1.2
Best Signal Level and a Margin The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec BCCH Txi Txj And P rec BCCH Best P rec BCCH – M ji
M is the specified margin (dB). The Best function considers the highest value from a list of values. •
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest.
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If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
Second Best Signal Level and a Margin The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec BCCH nd
Txi Txj And P rec BCCH 2 Best P rec BCCH – M ji
M is the specified margin (dB). The 2nd Best function considers the second highest value from a list of values. • • •
3.4.4.1.4
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the second highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the second highest or within a 2 dB margin from the second highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 3rd best servers.
Best Signal Level per HCS Layer and a Margin For each HCS layer, k, the service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec BCCH Txi Txj And P rec BCCH Best P rec BCCH – M ji
M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
3.4.4.1.5
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
Second Best Signal Level per HCS Layer and a Margin For each HCS layer, k, the service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec BCCH nd
Txi Txj And P rec BCCH 2 Best P rec BCCH – M ji
M is the specified margin (dB). The 2nd Best function considers the second highest value from a list of values. • • •
3.4.4.1.6
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the second highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the second highest or within a 2 dB margin from the second highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 3rd best servers.
HCS Servers and a Margin The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec BCCH Txi Txj And P rec BCCH Best P rec BCCH – M ji Txi
And the received P rec BCCH exceeds the reception threshold defined per HCS layer.
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M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
3.4.4.1.7
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
Highest Priority HCS Server and a Margin The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold P rec BCCH Txi Txj And P rec BCCH Best P rec BCCH – M ji
And Txi belongs to the HCS layer with the highest priority. The highest priority is defined by the priority field (0: lowest). Txi
And the received P rec BCCH exceeds the reception threshold defined per HCS layer. In the case two layers have the same priority, the traffic is served by the transmitter for which the difference between the received signal strength and the HCS threshold is the highest. The way the competition is managed between layers with the same priority can be modified. For more information, see the Administrator Manual. M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
3.4.4.2 Coverage Display 3.4.4.2.1
Coverage Resolution The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information).
3.4.4.2.2
Display Types It is possible to display the coverage predictions with colours depending on criteria such as: BER Only the pixels with a codec mode assigned are coloured. The pixel colour depends on the BER value. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as transmitter coverage areas and BER display thresholds. Each layer shows the BER in the transmitter coverage area. FER Only the pixels with a codec mode assigned are coloured. The pixel colour depends on the FER value. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as transmitter coverage areas and FER display thresholds. Each layer shows the FER in the transmitter coverage area. MOS Only the pixels with a codec mode assigned are coloured. The pixel colour depends on the MOS value. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as transmitter coverage areas and MOS display thresholds. Each layer shows the MOS in the transmitter coverage area.
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Max BER Only the pixels with a codec mode assigned are coloured. The pixel colour depends on the highest BER value among the BER values for all the transmitters covering the pixel. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as BER display thresholds. Each layer shows the BER value. Max FER Only the pixels with a codec mode assigned are coloured. The pixel colour depends on the highest FER value among the FER values for all the transmitters covering the pixel. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as FER display thresholds. Each layer shows the FER value. Max MOS Only the pixels with a codec mode assigned are coloured. The pixel colour depends on the highest MOS value among the MOS values for all the transmitters covering the pixel. Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many layers as MOS display thresholds. Each layer shows the MOS value.
3.5 UL Coverage Predictions For each TBC transmitter, Txi, Atoll calculates the selected parameter at each Txi inside its calculation area. Results are shown on each pixel, each pixel acting as a transmitting terminal. Hence, transmitters are here (non-interfering) receivers. Coverage prediction parameters to be set are: • •
The coverage conditions in order to determine the DL service area of each TBC transmitter, and The display settings to select the displayed parameter and its shading levels.
Two interfaced predictions are available: • •
One prediction which shows on each pixel UL losses or UL signal levels One prediction which shows on each pixel UL C/I levels.
Additional studies such as codec modes and coding schemes predictions are used during simulations but are not graphically available.
3.5.1 DL Service Area Determination Atoll uses parameters entered in the Condition tab of the coverage prediction properties dialogue to determine the service areas of the TBC transmitters. We can distinguish eight cases as below. Let us assume that: • •
Each transmitter, Txi, belongs to a Hierarchical Cell Structure (HCS) layer, k, with a defined priority and a defined reception threshold. No max range is set.
3.5.1.1 All Servers The service area of Txi corresponds to the pixels : Txi
MinimumThreshold P rec tt MaximumThreshold Txi
For pure signal level-based calculations (not C/I or C/(I+N)), P rec tt can be replaced Txi
Txi
with L total – DL or L path .
3.5.1.2 Best Signal Level and a Margin The service area of Txi corresponds to the pixels : Txi
MinimumThreshold P rec tt MaximumThreshold Txi
For pure signal level-based calculations (not C/I or C/(I+N)), P rec tt can be replaced Txi
Txi
with L total – DL or L path .
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Txi Txj And P rec tt Best P rec tt – M ji
M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
3.5.1.3 Second Best Signal Level and a Margin The service area of Txi corresponds to the pixels: Txi
MinimumThreshold P rec tt MaximumThreshold Txi
For pure signal level-based calculations (not C/I or C/(I+N)), P rec tt can be replaced Txi
Txi
with L total – DL or L path .
nd
Txi Txj And P rec tt 2 Best P rec tt – M ji
M is the specified margin (dB). The 2nd Best function considers the second highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the second highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the second highest or within a 2 dB margin from the second highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 3rd best servers.
3.5.1.4 Best Signal Level per HCS Layer and a Margin For each HCS layer, k, the service area of Txi corresponds to the pixels : Txi
MinimumThreshold P rec tt MaximumThreshold Txi
For pure signal level-based calculations (not C/I or C/(I+N)), P rec tt can be replaced Txi
Txi
with L total – DL or L path .
Txi Txj And P rec BCCH Best P rec BCCH – M ji
M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
3.5.1.5 Second Best Signal Level per HCS Layer and a Margin For each HCS layer, k, the service area of Txi corresponds to the pixels : Txi
MinimumThreshold P rec tt MaximumThreshold
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Txi
For pure signal level-based calculations (not C/I or C/(I+N)), P rec tt can be replaced Txi
Txi
with L total – DL or L path .
nd
Txi Txj And P rec BCCH 2 Best P rec BCCH – M ji
M is the specified margin (dB). The 2nd Best function considers the second highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the second highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the second highest or within a 2 dB margin from the second highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 3rd best servers.
3.5.1.6 HCS Servers and a Margin The service area of Txi corresponds to the pixels : Txi
MinimumThreshold P rec tt MaximumThreshold Txi
For pure signal level-based calculations (not C/I or C/(I+N)), P rec tt can be replaced Txi
Txi
with L total – DL or L path .
Txi Txj And P rec BCCH Best P rec BCCH – M ji Txi
And the received P rec tt exceeds the reception threshold defined per HCS layer. M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
3.5.1.7 Highest Priority HCS Server and a Margin The service area of Txi corresponds to the pixels : Txi
MinimumThreshold P rec tt MaximumThreshold Txi
For pure signal level-based calculations (not C/I or C/(I+N)), P rec tt can be replaced Txi
Txi
with L total – DL or L path .
Txi Txj And P rec BCCH Best P rec BCCH – M ji
And Txi belongs to the HCS layer with the highest priority. The highest priority is defined by the priority field (0: lowest). Txi
And the received P rec tt exceeds the reception threshold defined per HCS layer. In the case two layers have the same priority, the traffic is served by the transmitter for which the difference between the received signal strength and the HCS threshold is the highest. The way the competition is managed between layers with the same priority can be modified. For more information, see the Administrator Manual.
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M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels the received signal level from Txi is the highest. If M = 2 dB, Atoll considers pixels the received signal level from Txi is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels the received signal level from Txi is 2 dB higher than the signal levels from transmitters which are 2nd best servers.
3.5.1.8 Best Idle Mode Reselection Criterion (C2) Such type of coverage is useful : • •
To compare idle and dedicated mode best servers for voice traffic Display the GPRS/EDGE best server map (based on GSM idle mode)
The path loss criterion C1 used for cell selection and reselection is defined by: Txi
C1 = P rec BCCH – MinimumThreshold BCCH The path loss criterion (GSM03.22) is satisfied if C1 0 . The reselection criterion C2 is used for cell reselection only and is defined by: C2 = C1 + CELL_RESELECT_OFFSET CELL_RESELECT_OFFSET is the Cell Reselect Offset defined for the transmitter. The service area of Txi corresponds to the pixels : Txi
MinimumThreshold P rec BCCH MaximumThreshold Txi
For pure signal level-based calculations (not C/I or C/(I+N)), P rec tt can be replaced Txi
Txi
with L total – DL or L path .
And C2
Txi
Txj BCCH = Best C2 BCCH j
The Best function considers the highest value from a list of values. On each pixel, the transmitter with the highest C2 value is kept. It corresponds to the best server in idle mode. C2 is defined as an integer in the 3GPP specifications, therefore, the C2 values in the above calculations are rounded down to the nearest integer.
3.5.2 Coverage by UL Signal Level 3.5.2.1 Coverage Resolution The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information).
3.5.2.2 Display Types UL signal levels and UL losses calculations are explained in "UL Signal Level" on page 125. It is possible to display the coverage by UL signal level with colours depending on any transmitter attribute or other criteria such as:
3.5.2.2.1
UL Signal Level (in dBm, dBµV, dBµV/m) Atoll calculates the signal level received at each transmitter on its service area from surrounding pixels. A pixel of a service area is coloured if the UL signal level is greater than or equal to the defined minimum thresholds (pixel colour depends on signal level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as transmitter service areas. Each layer shows the different UL signal levels at the transmitter on its service area.
3.5.2.2.2
Best UL Signal Level (in dBm, dBµV, dBµV/m) Atoll calculates the signal level received at each transmitter on its service area from surrounding pixels. When other service areas overlap the studied one, Atoll chooses the highest value. A pixel of a service area is coloured if the UL signal level is
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greater than or equal to the defined thresholds (the pixel colour depends on the signal level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as transmitter service areas. Each layer shows the different UL signal levels at the transmitter on its service area.
3.5.2.2.3
UL Total Losses (dB) Atoll calculates total losses from the terminal at each transmitter on its service area. A pixel of a service area is coloured if UL total losses are greater than or equal to the defined minimum thresholds (pixel colour depends on UL total losses). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as service areas. Each layer shows the different UL total losses at the transmitter on its service area.
3.5.2.2.4
Minimum UL Total Losses (dB) Atoll calculates total losses from the transmitter on each pixel of each transmitter service area. When other service areas overlap the studied one, Atoll chooses the lowest value. A pixel of a service area is coloured if UL total losses are greater than or equal to the defined minimum thresholds (pixel colour depends on total losses). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as service areas. Each layer shows the different total losses levels in the transmitter service area.
3.5.3 Coverage by UL C/I An UL C/I coverage predictions is available. It provides the UL C/I level at the transmitter level caused by surrounding uplink traffic.
3.5.3.1 Coverage Resolution The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information).
3.5.3.2 UL C/I Evaluation The UL C/I level can be computed as follows, for a given MSA C --I
MSA
Term
Tx
= P rec – N tot
UL
, Tx
Tx
MSA DL
•
N tot = N thermal + NF
•
P rec
•
N thermal is the thermal noise (-121 dBm by default or user-defined)
•
NF
•
MSA DL NRIntra – techno log y
Term
Tx
+ NR Intra – techno log y is the UL total noise at transmitter on the considered MSA
is the received signal level at the transmitter,
is the transmitter noise figure is the intra-technology UL noise rise at the considered MSA. Since UL noise rise are defined per
TRX, Atoll takes the TRX UL noise rise in case of non-hopping or extracts a mean noise rise from the several TRXs composing the MSA in case of Base Band Hopping or Synthesized Frequency Hopping. MSA For a given transmitter having several MSAs, all possible C are displayed in case the detailed results box is selected. If --I UL not, the worst results (the min C/I per transmitter) are retained.
3.5.3.3 Coverage Area Determination For each MSA, coverage area corresponds to pixels where C --I coverage prediction properties.
MSA
is between the lower and upper thresholds defined in the
UL
3.5.3.4 Display Types It is possible to display the coverage predictions with colours depending on any transmitter attribute or other criteria such as:
3.5.3.4.1
C/I Level Each pixel of the transmitter coverage area is coloured if the calculated UL C/I level is greater than or equal to the specified minimum thresholds (pixel colour depends on UL C/I level). Coverage consists of several independent layers whose visibility
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in the workspace can be managed. There are as many layers as transmitter service areas. Each layer shows the different UL C/I levels available in the transmitter coverage area.
3.5.3.4.2
Max C/I Level Atoll compares calculated UL C/I levels received from transmitters on each pixel of each transmitter coverage area coverage areas overlap the studied one and chooses the highest value. A pixel of a coverage area is coloured if the UL C/I level is greater than or equal to the specified thresholds (the pixel colour depends on the UL C/I level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area the highest received UL C/I level exceeds a defined minimum threshold.
3.5.3.4.3
Min C/I Level Atoll compares UL C/I levels received from transmitters on each pixel of each transmitter coverage area the coverage areas overlap the studied one and chooses the lowest value. A pixel of a coverage area is coloured if the UL C/I level is greater than or equal to the specified thresholds (the pixel colour depends on the UL C/I level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area the lowest received UL C/I level exceeds a defined minimum threshold.
3.5.4 Coverage by UL Coding Schemes An UL Coding Scheme coverage prediction is implemented in order to be used in simulations. The prediction itself does not have any interface. for the simulations, settings are hard coded and are described hereafter. These calculations are based on C/(I+N). Coding schemes are selected without using ideal link adaptation. Different GPRS/EDGE configurations may be defined for transmitter and terminals. In this case, Atoll only selects the coding schemes that are common in the two, and gives priority to the thresholds defined in the transmitter configuration. If no terminal type is defined for the calculation, or if the terminal type does not have any GPRS/EDGE configuration assigned to it, Atoll only uses the GPRS/EDGE configuration of the transmitter. If the transmitter does not have any GPRS/EDGE configuration assigned to it, no coding scheme selection and throughput calculation is carried out. In the following calculations, we assume that: Txi
•
P rec TRX is the DL signal level received from the BCCH of Txi on each pixel of the Txi coverage area,
•
P rec
• •
CS is the set of all available coding schemes, Reception Threshold CS are the values of reception thresholds for the coding schemes available in the GPRS/EDGE
Term
is the UL the signal level received at each transmitter on its service area from surrounding pixels
configuration, • •
C ----------Threshold I + N CS are the values of C/(I+N) thresholds for the coding schemes available in the GPRS/EDGE configuration, The priorities of the coding scheme lists are as follows: DBS > DAS > MCS > CS.
Since the calculations are based on C/I and C/(I+N): • •
Atoll calculates the UL C/I to all the GPRS/EDGE TBC transmitters. The reception thresholds given for signal level C are internally converted to C/N thresholds (N is the thermal noise defined in the document database at -121 dBm by default) in order to be indexed by C/(I+N) values. C/I thresholds are also indexed by the C/(I+N) value.
For more information on UL C/I calculation, see "Coverage by UL C/I" on page 156.
3.5.4.1 Service Area Determination Atoll uses hard-coded parameters for simulations. In that case, the DL service area is based on the option "HCS servers" with a margin of 4 dB. The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold Prec tt Txi Txj And P rec BCCH Best P rec BCCH – 4dB ji Txi
And the received P rec BCCH exceeds the reception threshold defined per HCS layer.
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3.5.4.2 Coding Scheme Selection Atoll selects two coding schemes from among the coding schemes available in the GPRS/EDGE configuration, such that: For each MSA , cs C N = Lowest CS And, cs C I + N = Lowest CS
Term P rec C ----------------- ---------Threshold I + N CS N
Term P rec C ----------------- ----------- Threshold I + N CS I+N
csC/N is the coding scheme determined from the C/N, and csC/(I+N) is the coding scheme determined from the C/(I+N) level. Both coding schemes are the coding schemes with the lowest coding scheme numbers from the lowest priority coding scheme list. The selected coding scheme, cs, is the coding scheme with the higher coding scheme number among csC/N and csC/(I+N): cs = Max cs C N cs C I + N .
3.5.4.3 Throughput Calculation For the coding scheme csC/N determined above, the TP = f(C) graph is internally converted to TP = f(C/N) graph. A throughput value, TPC/N, corresponding to the C/(I+N) is determined from the TP = f(C/N) graph. For the coding scheme csC/(I+N) determined above, the TP = f(C/I) graph is internally converted to TP = f(C/(I+N)) graph. A throughput value, TPC/(I+N), corresponding to the C/(I+N) is determined from the TP = f(C/(I+N)) graph. The final throughput is computed by interpolating between the throughput values obtained from these two graphs. The throughput interpolation method consists in interpolating TPC/N and TPC/(I+N) according to the respective weights of I and N values. The resulting throughput TP is given by: TP = TP C N + 1 – TP C I + N pN = ------------------, pN is the thermal noise power (value in Watts), and p(I+N) is the interferences + thermal noise power (value pI + N in Watts).
3.5.5 Coverage by UL Codec Modes An UL Codec Mode coverage prediction is implemented in order to be used in simulations. The prediction itself does not have any interface. for the simulations, settings are hard coded and are described hereafter. Circuit quality indicator calculations include codec mode selection and CQI calculation. Codec modes are selected according to C/(I+N) quality without using ideal link adaptation. Once codec modes have been selected, CQI and number of used timeslots (0.5 in case of HR) corresponding to these codec modes are determined from the look-up tables. Different codec configurations may be defined for transmitter and terminals. In this case, Atoll only selects the coding schemes that are common in the two, and gives priority to the thresholds defined in the transmitter configuration. If no terminal type is defined for the calculation, or if the terminal type does not have any codec configuration assigned to it, Atoll only uses the codec configuration of the transmitter. If the transmitter does not have any codec configuration assigned to it, no codec mode selection and CQI calculation is carried out. If more than one codec modes satisfy the quality conditions, Atoll selects the higher priority codec mode. In the following calculations, we assume that: Txi
•
P rec TRX is the DL signal level received from the BCCH of Txi on each pixel of the Txi coverage area,
•
P rec
• •
CM is the set of all available codec modes, Adaptation Threshold CM are the values of adaptation thresholds for the codec modes available in the codec
Term
is the UL the signal level received at each transmitter on its service area from surrounding pixels
configuration, The computed noise N is compared to the codec configuration reference noise N Ref . If the values are the same, the defined graphs are used as is, otherwise the graphs are downshifted by the difference N – N Ref .
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Since the calculations are based on C/I and C/(I+N): •
Atoll calculates the UL C/I to all the GPRS/EDGE TBC transmitters.
For more information on UL C/I calculation, see "Coverage by UL C/I" on page 156.
3.5.5.1 Service Area Determination Atoll uses hard-coded parameters for simulations. In that case, the DL service area is based on the option "HCS servers" with a margin of 4 dB. The service area of Txi corresponds to the pixels : Txi
SubcellReceptionThreshold Prec BCCH Txi Txj And P rec BCCH Best P rec BCCH – 4dB ji Txi
And the received P rec BCCH exceeds the reception threshold defined per HCS layer.
3.5.5.2 Codec Mode Selection Atoll selects the highest priority codec mode, cm, from among the codec modes available in the codec configuration: For each MSA, cm = Highest Priority CM
Term P rec ----------------- Adaptation Threshold CM I+N
Term
P rec - , Atoll determines the CQI from the CQI=f(C/I) graph associated to the selected codec mode, cm. For -----------I+N
3.6 Traffic Analysis When starting a traffic analysis, Atoll distributes the traffic from maps to transmitters of each layer according to the compatibility criteria defined in the transmitter, services, mobility type, terminal type properties. Transmitters considered in traffic analysis are the active and filtered transmitters that belong to the focus zone. • •
If no focus zone exists in the .atl document, Atoll takes into account the computation zone. For details of the average timeslot capacity calculation, see the Network Dimensioning section (calculation of minimum reduction factor).
3.6.1 Traffic Distribution 3.6.1.1 Normal Cells (Nonconcentric, No HCS Layer) 3.6.1.1.1
Circuit Switched Services A user with a given circuit switched service, c, a terminal, t, and a mobility type, m, will be distributed to the BCCH and TCH subcells of a transmitter if: • •
3.6.1.1.2
The terminal, t, works on the frequency band used by the BCCH subcell, The terminal, t, works on the frequency band used by the TCH subcell.
Packet Switched Services A user with a given packet switched service, p, a terminal, t, and a mobility type, m, will be distributed to the BCCH and TCH subcells of a transmitter if: • • • •
The transmitter is an GPRS/EDGE station (option specified in the transmitter property dialogue), The terminal, t, is technologically compatible with the transmitter, The terminal, t, works on the frequency band used by the BCCH subcell, The terminal, t, works on the frequency band used by the TCH subcell.
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3.6.1.2 Concentric Cells In case of concentric cells, TCH_INNER TRX type has the highest priority to carry traffic.
3.6.1.2.1
Circuit Switched Services A user with a given circuit switched service, c, a terminal, t, and a mobility type, m, will be distributed to the TCH_INNER, BCCH and TCH subcells of a transmitter if: • •
3.6.1.2.2
The terminal, t, works on the frequency band used by the BCCH subcell, The terminal, t, works on the frequency band(s) used by the TCH_INNER and TCH subcells.
Packet Switched Services A user with a given packet switched service, p, a terminal, t, and a mobility type, m, will be distributed to the TCH_INNER, BCCH and TCH subcells of a transmitter if: • • • •
The transmitter is an GPRS/EDGE station (option specified in the transmitter property dialogue), The terminal, t, is technologically compatible with the transmitter, The terminal, t, works on the frequency band used by the BCCH subcell, The terminal, t, works on the frequency band(s) used by the TCH_INNER and TCH subcells.
3.6.1.3 HCS Layers For each HCS layer, k, you may specify the maximum mobile speed supported by the transmitters of the layer.
3.6.1.3.1
Circuit Switched Services A user with a given circuit switched service, c, a terminal, t, and a mobility type, m, will be distributed to the BCCH and TCH subcells (and TCH_INNER in case of concentric cells) of a transmitter if: • • •
3.6.1.3.2
The terminal, t, works on the frequency band used by the BCCH subcell, The terminal, t, works on the frequency band(s) used by the TCH_INNER and TCH subcells, The user’s mobility, m, is less than the maximum speed supported by the layer, k.
Packet Switched Services A user with a given packet switched service, p, a terminal, t, and a mobility type, m, will be distributed to the BCCH and TCH subcells (and TCH_INNER in case of concentric cells) of a transmitter if: • • • • •
The transmitter is an GPRS/EDGE station (option specified in the transmitter property dialogue), The terminal, t, is technologically compatible with the transmitter, The terminal, t, works on the frequency band used by the BCCH subcell, The terminal, t, works on the frequency band(s) used by the TCH_INNER and TCH subcells, The user mobility, m, is less than the maximum speed supported by the layer, k.
3.6.2 Calculation of the Traffic Demand per Subcell Here we assume that: • • •
Users considered for evaluating the traffic demand fulfil the compatibility criteria defined in the transmitter, services, mobility, terminal properties as explained above. Atoll distributes traffic on subcell service areas, which are determined using the option “Best signal level per HCS layer” with a 0dB margin and the subcell reception threshold as lower threshold. Same traffic is distributed to the BCCH and TCH subcells.
3.6.2.1 User Profile Traffic Maps 3.6.2.1.1
Normal Cells (Nonconcentric, No HCS Layer) Number of subscribers ( X up m ) for each TCH subcell (Txi, TCH), per user profile up with a given mobility m, is inferred as: X up m Txi TCH = S up m Txi TCH D Sup,m is the TCH service area containing the user profile up with the mobility m and D is the user profile density. For each behaviour described in the user profile up, Atoll calculates the probability for the user to be connected with a given service using a terminal t. Circuit Switched Services For a circuit switched service c, we have:
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N call d p up c t = ------------------3600 Ncall is the number of calls per hour and d is the average call duration (in seconds). Then, Atoll evaluates the traffic demand, D up c t m , in Erlangs for the subcell (Txi, TCH) service area. D up c t m Txi TCH = X up m Txi TCH p up c t Packet Switched Services (Max Rate) For a max rate packet switched service p, we have: N call V 8 p up p t = ----------------------------3600 Ncall is the number of calls per hour and V is the transmitted data volume per call (in Kbytes). Then, Atoll evaluates the traffic demand, D up p t m , in kbits/s for the subcell (Txi, TCH) service area. D up p t m Txi TCH = X up m Txi TCH p up p t Packet Switched Services (Constant Bit Rate) For a constant bit packet switched service p, we have: N call d p up p t = ------------------3600 Ncall is the number of calls per hour and d is the average call duration (in seconds). Then, Atoll evaluates the traffic demand, D up p t m , in kbits/s for the subcell (Txi, TCH) service area. D up p t m Txi TCH = X up m Txi TCH p up p t
3.6.2.1.2
Concentric Cells In case of concentric cells, Atoll distributes a part of traffic on the TCH_INNER service area (TCH_INNER is the highest priority traffic carrier) and the remaining traffic on the outer ring served by the TCH subcell. The traffic spread over the TCH_INNER subcell may overflow to the TCH subcell. In this case, the traffic demand is the same on the TCH_INNER subcell but increases on the TCH subcell. •
Traffic overflowing from the TCH_INNER to the TCH is not uniformly spread over the TCH service area. It is still located on the TCH_INNER service area.
Number of subscribers ( X up m ) for each TCH_INNER (Txi, TCH_INNER) and TCH (Txi, TCH) subcell, per user profile up with a given mobility m, is inferred as: X up m Txi,TCH_INNER = S up m Txi,TCH_INNER D X up m Txi,TCH = S up m Txi,TCH – S up m Txi,TCH_INNER D S up m Txi,TCH_INNER and S up m Txi,TCH respectively refer to the TCH_INNER and TCH subcell service areas containing the user profile up with the mobility m. D is the user profile density.
Figure 3.4: Representation of a Concentric Cell TXi
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Circuit Switched Services For each user of the user profile up using a circuit switched service c with a terminal t, Atoll calculates the probability ( p up c t ) of the user being connected. Calculations are detailed in "Circuit Switched Services" on page 159. Then, Atoll evaluates the traffic demand, D up c t m , in Erlangs in the (Txi, TCH_INNER) and (Txi, TCH) subcell service areas. D up c t m Txi,TCH_INNER = X up m Txi,TCH_INNER p up c t D up c t m Txi,TCH = X up m Txi,TCH p up c t + D up c t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi,TCH_INNER is the maximum rate of traffic overflow (in %) specified for the TCH_INNER subcell. Packet Switched Services (Max Rate) For each user of the user profile up using a max rate packet switched service p with a terminal t, probability of the user being connected ( p up p t ) is calculated as explained in "Packet Switched Services" on page 159. Atoll evaluates the traffic demand, D up p t m , in kbits/s in the (Txi, TCH_INNER) and (Txi, TCH) subcell service areas. D up p t m Txi,TCH_INNER = X up m Txi,TCH_INNER p up p t D up p t m Txi,TCH = X up m Txi,TCH p up p t + D up p t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi,TCH_INNER is the maximum rate of traffic overflow (in %) specified for the TCH_INNER subcell. Packet Switched Services (Constant Bit Rate) For each user of the user profile up using a constant bit packet switched service p with a terminal t, probability of the user being connected ( p up p t ) is calculated as explained in "Packet Switched Services" on page 159. Atoll evaluates the traffic demand, D up p t m , in kbits/s in the (Txi, TCH_INNER) and (Txi, TCH) subcell service areas. D up p t m Txi,TCH_INNER = X up m Txi,TCH_INNER p up p t D up p t m Txi,TCH = X up m Txi,TCH p up p t + D up p t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi,TCH_INNER is the maximum rate of traffic overflow (in %) specified for the TCH_INNER subcell.
3.6.2.1.3
HCS Layers We assume two HCS layers: the micro layer has a higher priority than the macro layer. Txi belongs to the micro layer and Txj to the macro. The traffic contained in the input traffic map can be assigned to all the HCS layers. Normal Cells Atoll distributes traffic on the TCH service areas. The traffic capture is calculated with the option “Best signal level per HCS macro
layer” meaning that there is an overlap between HCS layers service areas. Let S overlapping Txj TCH denote this area (TCH service area of the macro layer overlapped by the TCH service area of the micro layer). Traffic on the overlapping area is distributed to the TCH subcell of the micro layer because it has a higher priority. On this area, traffic of the micro layer may overflow to the macro layer. In this case, the traffic demand is the same on the TCH subcell of the micro layer but increases on the TCH subcell of the macro layer. Traffic overflowing to the macro layer is not uniformly spread over the TCH service area of Txj. It is only located on the overlapping area.
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Figure 3.5: Representation of Micro and Macro Layers Atoll evaluates the traffic demand on the micro layer (higher priority) as explained above. For further details, please refer to formulas for normal cells. Then, it proceeds with the macro layer (lower priority). macro
Number of subscribers ( X up m ) for each TCH subcell (Txj, TCH) of the macro layer, per user profile up with the mobility m, is inferred as: macro
macro
macro
X up m Txj TCH = S up m Txj TCH – S up m – overlapping Txj TCH D macro
S up m Txj TCH is the TCH service area of Txj containing the user profile up with the mobility m and D is the profile density. For each user described in the user profile up with the circuit switched service c and the terminal t, the probability for the user being connected ( p up c t ) is calculated as explained in "Circuit Switched Services" on page 159. macro
Then, Atoll evaluates the traffic demand, D up c t m , in Erlangs in the subcell (Txj, TCH) service area. macro
S upm – overlapping Txj TCH macro macro micro D up c t m Txj TCH = X up m Txj TCH p up c t + D up c t m Txi TCH ----------------------------------------------------------------- Omax Txi TCH micro S up m Txi TCH For each user described in the user profile up with the packet switched service p and the terminal t, probability for the user to be connected ( p up p t ) is calculated as explained in "Packet Switched Services" on page 159. macro
Then, Atoll evaluates the traffic demand, D up p t m , in kbits/s in the subcell (Txj, TCH) service area. macro
S upm – overlapping Txj TCH macro macro micro D up p t m Txj TCH = X up m Txj TCH p up p t + D up p t m Txi TCH ----------------------------------------------------------------- Omax Txi TCH micro S up m Txi TCH O max Txi TCH is the maximum rate of traffic overflow (stated in %) specified for the TCH subcell of Txi (micro micro
layer) and S up m Txi TCH is the TCH service area of Txi containing the user profile up with the mobility m. Concentric Cells Atoll evaluates the traffic demand on the micro layer (higher priority HCS layer) as explained above. For further details, please refer to formulas given in case of concentric cells. Then, it proceeds with the macro layer (lower priority HCS layer). The traffic capture is calculated with the option “Best signal level per HCS layer”. It means that there are overlapping areas between HCS layers traffic is spread according to the layer priority. On these areas, traffic of the higher priority layer may overflow. The TCH_INNER service area of the macro layer is overlapped by the micro layer. This area consists of two parts: an area macro
overlapped by the TCH service area of the micro layer S overlapping – Txi TCH Txj,TCH_INNER and another overlapped by macro
the TCH_INNER service area of the micro layer S overlapping – Txi,TCH_INNER Txj,TCH_INNER . Let us consider three areas, S1, S2 and S3. macro
macro
S 1 = S up m Txj,TCH_INNER – S up m – overlapping – Txi TCH Txj,TCH_INNER macro
S 2 = S up m – overlapping – Txi,TCH_INNER Txj,TCH_INNER macro
S 3 = S up m – overlapping – Txi TCH Txj,TCH_INNER – S 2
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Figure 3.6: Concentric Cells macro
S up m Txj,TCH_INNER is the TCH_INNER subcell service area of Txj containing the user profile up with the mobility m. We only consider the overlapping areas containing the user profile up with the mobility m. macro
On S1, the number of subscribers per user profile up with a given mobility m ( X up m ) is inferred: macro
X up m Txj,TCH_INNER = S 1 D D is the user profile density. The traffic spread over the TCH_INNER service area of the micro layer may overflow on the TCH subcell. The traffic overflowing to the TCH subcell is located on the TCH_INNER service area. On S2, the TCH subcell traffic coming from the TCH_INNER subcell traffic overflow may overflow proportional to R2. S2 R 2 = ------------------------------------------------------micro S up m Txi,TCH_INNER The traffic spread over the ring served by the TCH subcell of the micro layer only may overflow on S3 proportional to R3. S3 R 3 = -------------------------------------------------------------------------------------------------micro micro S up m Txi,TCH – S up m Txi,TCH_INNER micro
micro
S up m Txi,TCH and S up m Txi,TCH_INNER are the TCH and TCH_INNER service areas of Txi respectively containing the user profile up with the mobility m. For each user described in the user profile up with a circuit switched service c and a terminal t, the probability for the user being connected ( p up c t ) is calculated as explained in "Circuit Switched Services" on page 159. Then, Atoll evaluates the macro
traffic demand, D up c t m , in Erlangs in the subcell (Txj, TCH_INNER) service area. macro
X up m Txj,TCH_INNER p up c t + macro
D up c t m Txj,TCH_INNER = R D micro Txi,TCH_INNER O Txi,TCH_INNER O Txi,TCH + 2 up c t m max max micro
R 3 X up m Txi TCH p up c t O max Txi TCH For each user described in the user profile up with a packet switched service p and a terminal t, probability for the user to be connected ( p up p t ) is calculated as explained in "Packet Switched Services" on page 159. macro
Then, Atoll evaluates the traffic demand, D up p t m , stated in kbits/s in the subcell (Txj, TCH_INNER) service area. macro
X up m Txj,TCH_INNER p up p t + macro
D up p t m Txj,TCH_INNER = R D micro 2 up p t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi,TCH + micro
R 3 X up m Txi TCH p up p t O max Txi TCH
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O max Txi TCH and O max Txi,TCH_INNER are the maximum rates of traffic overflow (stated in %) specified for the TCH and TCH_INNER subcells of Txi respectively. The area of the TCH ring of the macro layer is overlapped by the micro layer. There are two parts: an area overlapped by the macro
TCH service area of the micro layer S overlapping – Txi TCH Txj,TCH -- TCH_INNER and another one by the TCH_INNER macro
service area of the micro layer S overlapping – Txi,TCH_INNER Txj,TCH -- TCH_INNER . Let us consider three areas, S’1, S’2 and S’3. macro
macro
macro
S' 1 = S up m Txj,TCH – S up m Txj,TCH_INNER – S up m – overlapping – Txi TCH Txj,TCH -- TCH_INNER macro
S' 2 = S up m – overlapping – Txi,TCH_INNER Txj,TCH -- TCH_INNER macro
S' 3 = S up m – overlapping – Txi TCH Txj,TCH -- TCH_INNER – S' 2 macro
macro
S up m Txj,TCH and S up m Txj,TCH_INNER are the TCH and TCH_INNER subcell service areas of Txj respectively. We only consider the overlapping areas containing the user profile up with the mobility m. macro
On S’1, the number of subscribers per user profile up with a given mobility m ( X up m ) is inferred: macro
X up m Txj,TCH = S' 1 D D is the user profile density. The traffic spread over the TCH_INNER service area of the micro layer may overflow on the TCH subcell. The traffic overflowing on the TCH subcell is located on the TCH_INNER service area. On S’2, the TCH subcell traffic coming from the TCH_INNER subcell traffic overflow may overflow proportionally to R’2. S' 2 R' 2 = ------------------------------------------------------micro S up m Txi,TCH_INNER The traffic spread over the ring served by the TCH subcell of the micro layer only may overflow on S’3 proportional to R’3. S' 3 R' 3 = -------------------------------------------------------------------------------------------------micro micro S up m Txi,TCH – S up m Txi,TCH_INNER micro
micro
S up m Txi,TCH and S up m Txi,TCH_INNER are the TCH and TCH_INNER service areas of Txi respectively containing the user profile up with the mobility m. For each user described in the user profile up with a circuit switched service c and a terminal t, the probability for the user being connected ( p up c t ) is calculated as explained in "Circuit Switched Services" on page 159. macro
Then, Atoll evaluates the traffic demand, D up c t m , in Erlangs in the subcell (Txj, TCH) service area.
macro
X up m Txj TCH p up c t + macro
D up c t m Txj TCH =
macro
D up c t m Txj,TCH_INNER O max Txj,TCH_INNER + micro
R' 2 D up c t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi,TCH + micro
R' 3 X up m Txi TCH p up c t m O max Txi TCH For each user described in the user profile up with a packet switched service p and a terminal t, the probability for the user being connected ( p up p t ) is calculated as explained in "Packet Switched Services" on page 159. macro
Then, Atoll evaluates the traffic demand, D up p t m , in kbits/s in the subcell (Txj, TCH) service area.
macro
X up m Txj TCH p up p t + macro
D up p t m Txj TCH =
macro
D up p t m Txj,TCH_INNER O max Txj,TCH_INNER + micro
R' 2 D up p t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi,TCH + micro
R' 3 X up m Txi TCH p up p t m O max Txi TCH
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O max Txi,TCH is the maximum rate of traffic overflow (stated in %) specified for the TCH subcell of Txi (micro layer), O max Txi,TCH_INNER the maximum rate of traffic overflow indicated for the TCH_INNER subcell of Txi (macro layer), O max Txj,TCH_INNER the maximum rate of traffic overflow indicated for the TCH_INNER subcell of Txj (macro layer) and micro
X up m Txi TCH the number of subscribers with the user profile up and mobility m on the TCH service area of Txi (as explained in "Concentric Cells" on page 160).
3.6.2.2 Sector Traffic Maps We assume that the traffic map is built from a coverage by transmitter prediction calculated for the TCH subcells with options: • •
“HCS Servers” and no margin if the network only consists of normal cells and concentric cells, “Highest Priority HCS Server” and no margin in case of HCS layers.
When creating the traffic map, you have to specify the traffic demand per transmitter and per service (throughput for a max rate packet switched service and Erlangs for a circuit switched or constant bit rate packet switched service) and the global distribution of terminals and mobility types. Let E c Txi TCH denote the Erlangs for the circuit switched service, c, on the TCH subcell of Txi. Let T p Txi TCH denote the throughput of the packet switched service (Max Bit Rate), p, on the TCH subcell of Txi. Let E p Txi TCH denote the Erlangs for the packet switched service (Constant Bit Rate), p, on the TCH subcell of Txi. We assume that 100% of users have the terminal, t, and the mobility type, m.
3.6.2.2.1
Normal Cells (Nonconcentric, No HCS Layer) For each circuit switched service, c, Atoll evaluates the traffic demand, Dc,t,m, in Erlangs in the subcell (Txi, TCH) service area. D c t m Txi TCH = E c Txi TCH For each packet switched service (Max Bit Rate), p, Atoll evaluates the traffic demand, Dp,t,m, in kbits/s in the subcell (Txi, TCH) service area. D p t m Txi TCH = T p Txi TCH For each packet switched service (Constant Bit Rate), p, Atoll evaluates the traffic demand, Dp,t,m, in kbits/s in the subcell (Txi, TCH) service area. D p t m Txi TCH = E p Txi TCH TP p GBR TP p GBR is the guaranteed bit rate of the constant bit rate packet switched service p.
3.6.2.2.2
Concentric Cells In case of concentric cells, Atoll distributes a part of traffic on the TCH_INNER service area (TCH_INNER is the highest priority traffic carrier) and the remaining traffic, on the ring served by the TCH subcell only. The traffic spread over the TCH_INNER subcell may overflow to the TCH subcell. In this case, the traffic demand is the same on the TCH_INNER subcell and rises on the TCH subcell. Traffic overflowing from the TCH_INNER to the TCH is not uniformly spread over the TCH service area. It is only located on the TCH_INNER service area.
For each circuit switched service, c, Atoll evaluates the traffic demand, Dc,t,m, in Erlangs in the subcell, (Txi, TCH_INNER) and (Txi, TCH), service areas. S Txi,TCH_INNER D c t m Txi,TCH_INNER = -------------------------------------------- E c Txi TCH S Txi TCH and
D c t m Txi,TCH =
-------------------------------------------------------------------------------S Txi,TCH – S Txi,TCH_INNER E c Txi TCH + S Txi TCH D c t m Txi,TCH_INNER O max Txi,TCH_INNER
For each packet switched service (Max Bit Rate), p, Atoll evaluates the traffic demand, Dp,t,m, in kbits/s in the subcell, (Txi, TCH_INNER) and (Txi, TCH), service areas.
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S Txi,TCH_INNER D p t m Txi,TCH_INNER = -------------------------------------------- T p Txi TCH S Txi TCH and
D p t m Txi,TCH =
S Txi,TCH – S Txi,TCH_INNER --------------------------------------------------------------------------------- T p Txi TCH + S Txi TCH D p t m Txi,TCH_INNER O max Txi,TCH_INNER
O max Txi,TCH_INNER is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell, S Txi,TCH and S Txi,TCH_INNER are the TCH and TCH_INNER service areas of Txi respectively. For each packet switched service (Constant Bit Rate), p, Atoll evaluates the traffic demand, Dp,t,m, in kbits/s in the subcell, (Txi, TCH_INNER) and (Txi, TCH), service areas. S Txi,TCH_INNER D p t m Txi,TCH_INNER = -------------------------------------------- E p Txi TCH TP p GBR S Txi TCH and
D p t m Txi,TCH =
-------------------------------------------------------------------------------S Txi,TCH – S Txi,TCH_INNER E p Txi TCH TP p GBR + S Txi TCH D p t m Txi,TCH_INNER O max Txi,TCH_INNER
O max Txi,TCH_INNER is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell, S Txi,TCH and S Txi,TCH_INNER are the TCH and TCH_INNER service areas of Txi respectively.
3.6.2.2.3
HCS Layers We assume we have two HCS layers: the micro layer has a higher priority and the macro layer has a lower one. Txi belongs to the micro layer and Txj to the macro one. The traffic contained in the input traffic map can be assigned to all the HCS layers. Normal Cells Atoll distributes traffic on the TCH service areas. The traffic capture is calculated with the option “HCS Servers”. It means that macro
there is an overlapping area between HCS layers. Let S overlapping Txj TCH denote the TCH service area of the macro layer overlapped by the TCH service area of the micro layer. Traffic on the overlapping area is distributed to the TCH subcell of the micro layer (higher priority layer). On this area, traffic of the micro layer may overflow to the macro layer. In this case, the traffic demand is the same on the TCH subcell of the micro layer but rises on the TCH subcell of the macro layer. Traffic overflowing on the macro layer is not uniformly spread over the TCH service area of Txj. It is only located on the overlapping area.
Atoll starts evaluating the traffic demand on the micro layer (highest priority HCS layer). micro
For each circuit switched service, c, Atoll calculates the traffic demand, D c t m , in Erlangs in the subcell (Txi, TCH) service area. micro
D c t m Txi TCH = E c Txi TCH micro
For each packet switched service (Max Bit Rate), p, Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txi, TCH) service area. micro
D p t m Txi TCH = T p Txi TCH micro
For each packet switched service (Constant Bit Rate), p, Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txi, TCH) service area. micro
D p t m Txi TCH = E p Txi TCH TP p GBR Then, Atoll proceeds with the macro layer (lower priority HCS layer). macro
For each circuit switched service, c, Atoll calculates the traffic demand, D c t m , in Erlangs in the subcell (Txj, TCH) service area.
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macro
S overlapping Txj TCH macro micro - O max Txi TCH D c t m Txj TCH = E c Txj TCH + D c t m Txi TCH ---------------------------------------------------micro S Txi TCH macro
For each packet switched service (Max Bit Rate), p, Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txj, TCH) service area. macro
S overlapping Txj TCH macro micro - O max Txi TCH D p t m Txj TCH = T p Txj TCH + D p t m Txi TCH ---------------------------------------------------micro S Txi TCH O max Txi TCH is the maximum rate of traffic overflow (in %) specified for the TCH subcell of Txi (micro cell) and S
micro
Txi TCH the TCH service area of Txi. macro
For each packet switched service (Constant Bit Rate), p, Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txj, TCH) service area. macro
S overlapping Txj TCH macro micro - O max Txi TCH D p t m Txj TCH = E p Txi TCH TP p GBR + D p t m Txi TCH ---------------------------------------------------micro S Txi TCH O max Txi TCH is the maximum rate of traffic overflow (in %) specified for the TCH subcell of Txi (micro cell) and S
micro
Txi TCH the TCH service area of Txi. You can restrict the traffic assignement of each traffic map to a specific HCS layer in the running options of the traffic capture. If you do so, no overflow occurs between HCS layers and the only overflow which is considered occurs within concentric cells (See "Concentric Cells" on page 160).
Concentric Cells Atoll evaluates the traffic demand on the micro layer as explained above in case of concentric cells and then proceeds with the macro layer (lower priority layer). The traffic capture is calculated with the option “HCS Servers”. It means that there is overlapping areas between HCS layers traffic is spread over according to the layer priority. On these areas, traffic of the higher priority layer may overflow.
Figure 3.7: Concentric Cells The TCH_INNER service area of the macro layer is overlapped by the micro layer. This area consists of two parts: an area macro
overlapped by the TCH service area of the micro layer S overlapping – Txi TCH Txj,TCH_INNER and another overlapped by macro
the TCH_INNER service area of the micro layer S overlapping – Txi,TCH_INNER Txj,TCH_INNER . Let us consider three areas, S1, S2 and S3.
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S1 = S
macro
macro
Txj,TCH_INNER – S overlapping – Txi TCH Txj,TCH_INNER
macro
S 2 = S overlapping – Txi,TCH_INNER Txj,TCH_INNER macro
S 3 = S overlapping – Txi TCH Txj,TCH_INNER – S 2 S
macro
Txj,TCH_INNER is the TCH_INNER subcell service area of Txj.
The traffic specified for Txj in the map description ( E c Txj TCH ) is spread over S1 proportionally to R1. S1 R 1 = ------------------------------------map S Txj TCH map
S Txj TCH is the TCH service area of Txj in the traffic map with the option “Best signal level of the highest priority layer”. The traffic spread over the TCH_INNER service area of the micro layer may overflow to the TCH subcell. The traffic overflowing to the TCH subcell is located on the TCH_INNER service area. On S2, the TCH subcell traffic coming from the TCH_INNER subcell traffic overflow may overflow proportional to R2. S2 R 2 = ------------------------------------------------------micro S Txi,TCH_INNER The traffic spread over the ring only served by the TCH subcell of the micro layer may overflow on S3 proportional to R3. S3 R 3 = -------------------------------------------------------------------------------------------------micro micro S Txi,TCH – S Txi,TCH_INNER macro
For each circuit switched service, c, Atoll calculates the traffic demand, D c t m , in Erlangs in the subcell (Txj, TCH_INNER) service area. R 1 E c Txj TCH + macro
D c t m Txj,TCH_INNER =
micro
R 2 D c t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi TCH + micro
micro
S Txi TCH – S Txi,TCH_INNER - E c Txi TCH O max Txi TCH R 3 ---------------------------------------------------------------------------------------------------------micro S Txi TCH macro
For each packet switched service (Max Bit Rate), p, Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txj, TCH_INNER) service area. R 1 T p Txj TCH + macro
D p t m Txj,TCH_INNER =
O max Txi TCH
micro
R 2 D p t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi TCH + micro
micro
S Txi TCH – S Txi,TCH_INNER - R 3 --------------------------------------------------------------------------------------------------------- T p Txi TCH O max Txi TCH micro Txi TCH S
is the maximum rate of traffic overflow (stated in %) specified for the TCH subcell of Txi,
O max Txi,TCH_INNER is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell of Txi and S
micro
Txi TCH is the TCH subcell service area of Txi. macro
For each packet switched service (Constant Bit Rate), p, Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txj, TCH_INNER) service area. R 1 E p Txi TCH TP p GBR + micro
R 2 D p t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi TCH + macro
D p t m Txj,TCH_INNER =
micro micro S Txi TCH – S Txi,TCH_INNER - ---------------------------------------------------------------------------------------------------------micro Txi TCH S R3 E Txi TCH TP p p GBR O max Txi TCH
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is the maximum rate of traffic overflow (stated in %) specified for the TCH subcell of Txi,
O max Txi,TCH_INNER is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell of Txi and S
micro
Txi TCH is the TCH subcell service area of Txi.
The area of the TCH ring of the macro layer is overlapped by the micro layer. There are two parts: an area overlapped by the TCH service area of the micro layer
macro
S overlapping – Txi TCH Txj,TCH -- TCH_INNER
TCH_INNER service area of the micro layer
macro S overlapping – Txi,TCH_INNER Txj,TCH
and another overlapped by the
-- TCH_INNER .
Let us consider three areas, S’1, S’2 and S’3. S' 1 = S
macro
Txj TCH – S
macro
macro
Txj,TCH_INNER – S overlapping – Txi TCH Txj,TCH -- TCH_INNER
macro
S' 2 = S overlapping – Txi,TCH_INNER Txj,TCH -- TCH_INNER macro
S' 3 = S overlapping – Txi TCH Txj,TCH -- TCH_INNER – S' 2 S
macro
Txj TCH and S
macro
Txj,TCH_INNER are the TCH and TCH_INNER subcell service areas of Txj respectively.
The traffic specified for Txj in the map description ( E c Txj TCH ) is spread over S’1 proportional to R’1. S' 1 R' 1 = ------------------------------------map S Txj TCH map
S Txj TCH is the TCH service area of Txj in the traffic map with the option “Best signal level of the highest priority layer”. The traffic spread over the TCH_INNER service area of the micro layer may overflow to the TCH subcell. The traffic overflowing to the TCH subcell is located on the TCH_INNER service area. On S’2, the TCH subcell traffic coming from the TCH_INNER subcell traffic overflow may overflow proportional to R’2. S' 2 R' 2 = ------------------------------------------------------micro S Txi,TCH_INNER The traffic spread over the ring only served by the TCH subcell of the micro layer may overflow on S’3 proportional to R’3. S' 3 R' 3 = -------------------------------------------------------------------------------------------------micro micro S Txi,TCH – S Txi,TCH_INNER macro
For each circuit switched service, c, Atoll calculates the traffic demand, D c t m , in Erlangs in the subcell (Txj, TCH) service area.
R' 1 E c Txj TCH + macro
macro
D c t m Txj TCH =
D c t m Txj,TCH_INNER O max Txj,TCH_INNER + micro
R' 2 D c t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi TCH + micro
micro
S Txi,TCH – S Txi,TCH_INNER - E c Txi TCH O max Txi TCH R' 3 ------------------------------------------------------------------------------------------------------micro S Txi,TCH macro
For each packet switched service (Max Bit Rate), p,Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txj, TCH) service area.
R' 1 T p Txj TCH + macro
macro D p t m Txj
TCH =
D c t m Txj,TCH_INNER O max Txj,TCH_INNER + micro
R' 2 D p t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi TCH + micro
micro
S Txi,TCH – S Txi,TCH_INNER - T p Txi TCH O max Txi TCH R' 3 ------------------------------------------------------------------------------------------------------micro S Txi,TCH
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O max Txj,TCH_INNER is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell of Txj, O max Txi TCH
is the maximum rate of traffic overflow (stated in %) specified for the TCH subcell of Txi,
O max Txi,TCH_INNER is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell of Txi, micro
S Txi.
Txi,TCH is the TCH subcell service area of Txi and S
micro
Txi,TCH_INNER is the TCH_INNER subcell service area of macro
For each packet switched service (Constant Bit Rate), p,Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txj, TCH) service area.
R' 1 E p Txi TCH TP p GBR + macro
D c t m Txj,TCH_INNER O max Txj,TCH_INNER + micro
macro
D p t m Txj TCH =
R' 2 D p t m Txi,TCH_INNER O max Txi,TCH_INNER O max Txi TCH + micro micro S Txi,TCH – S Txi,TCH_INNER ------------------------------------------------------------------------------------------------------micro S Txi,TCH R' 3 E p Txi TCH TP p GBR O max Txi TCH
O max Txj,TCH_INNER is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell of Txj, O max Txi TCH
is the maximum rate of traffic overflow (stated in %) specified for the TCH subcell of Txi,
O max Txi,TCH_INNER is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell of Txi, micro
S Txi.
Txi,TCH is the TCH subcell service area of Txi and S
micro
Txi,TCH_INNER is the TCH_INNER subcell service area of
3.7 Network Dimensioning Atoll is capable of dimensioning a GSM GPRS EDGE network with a mixture of circuit and package switched services. This section describes the technical details of Atoll’s dimensioning engine.
3.7.1 Dimensioning Models and Quality Graphs In Atoll, a dimensioning model is an entity utilized by the dimensioning engine along with other inputs (traffic, limitations, criteria, etc.) in the process of dimensioning. A dimensioning model defines the QoS KPIs to be taken into account when dimensioning a network for both circuit and packet switched traffic. The user can define either to use Erlang B or Erlang C queuing model for circuit switched traffic and can define which KPIs to consider when dimensioning the network for packet switched traffic. The dimensioning engine will only utilize the quality curves of the KPI selected. The KPIs not selected are supposed to be either already satisfactory or not relatively important.
3.7.1.1 Circuit Switched Traffic The network dimensioning for circuit switched traffic is performed using the universally accepted and adopted Erlang B and Erlang C formulas. The dimensioning criterion in these formulas is the Grade of Service or the allowed blocking probability of the circuit switched traffic. In the Erlang B approach, this Grade of Service is defined as the percentage of incoming circuit switched calls that are blocked due to lack of resources or timeslots. This formula implies a loss system. The blocked calls are supposed to be lost and the caller has to reinitiate it. In the Erlang C approach, the Grade of Service is the percentage of incoming calls that are placed in a waiting queue when there are no resources available, until some resources or timeslots are liberated. This queuing system has no lost calls. As the load on the system increases, the average waiting time in the queue also increases. These formulas and their details are available in many books. For example, Wireless Communications Principles and Practice by Theodore S. Rappaport, Prentice Hall. Following the common practice, network dimensioning in Atoll is based on the principle that a voice or GSM call has priority over data transmission. Therefore, as explained later in the network dimensioning steps, Atoll first performs network dimensioning according to the circuit switched traffic present in the subcell in order to ensure the higher priority service availability before performing the same for the packet switched traffic.
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3.7.1.2 Packet Switched Traffic Since packet switched traffic does not occupy an entire timeslot the whole time, it is much more complicated to study than circuit switched traffic. Packet traffic is intermittent and bursty. Whenever there is packet data to be transferred, a Temporary Block Flow (TBF) is initiated for transferring these packets. Multiple TBFs can be multiplexed on the same timeslot. This implies that there can be many packet switched service users that have the same timeslots assigned for packet data transfer but at different intervals of time. This multiplexing of a number of packet switched service users over the same timeslots incurs a certain reduction in the throughput (data transfer rate) for each multiplexed user. This reduction in the throughput is more perceivable when the system traffic load is high. The following parts describe the three most important Key Performance Indicators in GPRS/EDGE networks and how they are modelled in Atoll.
3.7.1.2.1
Throughput Throughput is defined as the amount of data delivered to the Logical Link Control Layer in a given unit of time. Each temporary block flow (TBF), and hence each user, has an associated measured throughput sample in a given network. Each network will have a different throughput probability distribution depending on the load and network configuration. Instead of using the precise probability distributions, it is more practical to compute the average and percentile throughput values. In GPRS, the resources are shared between the users being served, and consequently, the throughput is reduced as the number of active users increases. This reduction in user perceived throughput is modelled through a reduction factor. The throughput experienced by a user accessing a particular service can be calculated as: User throughput = Number of allocated timeslots x Timeslot capacity x Reduction Factor Or User throughput per allocated timeslot = Timeslot capacity x Reduction Factor Timeslot Capacity The timeslot capacity is the average throughput per fully utilized timeslot. It represents the average throughput from the network point of view. It mainly depends on the network’s propagation conditions and criteria in the coverage area of a transmitter (carrier power, carrier-to-interference distribution, etc.). It is a measure of how much data the network is able to transfer with 1 data Erlang, or in other words, how efficiently the hardware resources are being utilized by the network. It may also depend on the RLC protocol efficiency. Atoll computes the average timeslot capacity during the traffic analysis and is used to determine the minimum throughput reduction factor. But since this information is displayed in the network dimensioning results (only due to relevance), this information has been considered as a part of the network dimensioning process in this document. Timeslot Utilisation Timeslot utilization takes into account the average number of timeslots that are available for packet switched traffic. It is a measure of how much the network is loaded with data services. Networks with timeslot utilisation close to 100% are close to saturation and the end-user performance is likely to be very poor. In Atoll this parameter is termed as the Load (Traffic load for circuit switched traffic and packet switched traffic load for packet switched traffic). It is described in more detail in the Network dimensioning steps section. Reduction Factor Reduction factor takes into account the user throughput reduction due to timeslot sharing among many users. The figure below shows how the peak throughput available per timeslot is reduced by interference and sharing.Reduction factor is a function of the number of timeslots assigned to a user (Nu), number of timeslots available in the system (Ns) and the average system packet switched traffic load (Lp) (utilization of resources in the system). Data Erlangs or data traffic is given by: Data Erlangs = L P N S
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Figure 3.8: Reduction of Throughput per Timeslot More precisely, the reduction factor is a function of the ratio Ns/Nu (Np). Np models the equivalent timeslots that are available for the packet switched traffic in the system. For example, a 24-timeslot system with each user assigned 3 timeslots per connection can be modelled by a single timeslot connection system with 8 timeslots in total. The formula for reduction factor can be derived following the same hypotheses followed by Erlang in the derivation of the blocking probability formulas (Erlang B and Erlang C). Let X be a random variable that measures the reduction factor in a certain system state: 0 if n = 0 1 if 0 < n NP
X
N -----P- if n > NP n n is the instantaneous number of connections in the system. The throughput reduction factor is defined as:
P X= n
X -------------------P X= 0
RF
n=0
Or,
RF =
PX= n
X --------------------------n=0 P X= i i
0
Here, P(X=n) is the probability function of having n connections in the system. Under the same assumptions as those of the Erlang formulas, the probability function can be written as: n
LP NP ----------------------n! P X = n = --------------------------------------------------------------------------------------N P
LP NP
i
LP NP ----------------------------- i – NP + 1 N P! N P
+ --------------------i! i=0
i=N
P
if 0 n N P
i
n
LP NP -----------------------------i – N P N P! N P P X = n = --------------------------------------------------------------------------------------N P
LP NP
i
LP NP ----------------------------- i – NP + 1 N P! N P
+ --------------------i! i=0
i = NP
if n > N P
i
Hence the reduction factor can finally be written as:
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i
LP NP --------------------- + i!
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i
N LP NP -----P- -----------------------------i – N i P i=1 i = N + 1 N P! N P P RF = ------------------------------------------------------------------------------------------------------N
P
i
LP NP --------------------- + i!
i=1
i
LP NP -----------------------------i – N P + 1 N P! N P
i = NP
This formula is not directly applicable in any software application due to the summations up to infinity. Atoll uses the following version of this formula that is exactly the same formula without the summation overflow problem. NP
N
NP + 1 P n n NP L LP NP ----------------------- – ------------------- ln 1 – L P + ----P N P! n! n n = 1 n = 1 RF = -----------------------------------------------------------------------------------------------------------------------N P
n=1
NP
n LP LP NP LP NP ----------------------- + -------------------------- -------------N P! 1 – LP n!
The default quality curves for the Reduction Factor have been derived using the above formula. Each curve is for a fixed number of timeslots available for packet switched traffic (Np) describing the reduction factor at different values of packet switched traffic load (Lp). The figure below contains all the reduction factor quality curves in Atoll. The Maximum reduction factor can be 1, implying a maximum throughput, and the minimum can be 0, implying a saturated system with no data throughput.
Figure 3.9: Reduction Factor for Different Packet Switched Traffic Loads (Lp, X-axis) Each curve in the above figure represents an equivalent number of packet switched timeslots, NP.
3.7.1.2.2
Delay Delay is the time required for an LLC PDU to be completely transferred from the SGSN to the MS, or vice versa. As the delay is a function of the delays and the losses incurred at the packet level, the network parameters, such as the packet queue length, and different protocol properties, such as the size of the LLC PDU, become important. It is also quite dependent upon the radio access round trip time (RA RTT) and has a considerable impact on the application level performance viewed by the user. The delay parameter is a user level parameter rather than being a network level quantity, like throughput per cell, timeslot capacity, TBF blocking and reduction factor, hence it is difficult to model and is currently under study. Hence, no default curve is presently available for delay in Atoll.
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3.7.1.2.3
Blocking Probability In GPRS, there is no blocking as in circuit switched connections. If a new temporary block flow (TBF) establishment is requested and there are already M users per timeslot, M being the maximum limit of multiplexing per timeslot (Multiplexing factor), the request is queued in the system to be established later when resources become available. Supposing that M number of users can be multiplexed over a single timeslot (PDCH), we can have a maximum of M * Np users in the system. This implies that if a new TBF is requested when there are already M * Np users active, it will be blocked and placed in a queue. So the blocking probability is the probability of having M * Np + 1 users in the system or more, meaning, P X= n
for n = M N P + 1
as in this case n is always greater than Np, we have, n
LP NP ----------------------------- i – NP N P! N P P X = n = --------------------------------------------------------------------------------------N P
i
LP NP --------------------- + i!
i=0
i
LP NP ----------------------------- i – NP + 1 N P! N P
i = NP
So, the Blocking Probability can be given as:
BP =
n
LP NP ------------------------------ 1 – NP N ! N n = MN +1 P P P P X = n = ---------------------------------------------------------------------------------------N
P
n = MN+1
i
LP NP --------------------- + i!
i=0
i = NP
i
LP NP ------------------------------ 1 – NP + 1 N P! N P
Eliminating the summations to infinity, the blocking probability can be stated in a simpler form: M NP
LP NP LP ----------------------------------------- ------------ M NP – NP 1 – L P N P! N P BP = ---------------------------------------------------------------------------------N P
i=0
NP
i LP LP NP LP NP --------------------- + -------------------------- ------------N P! 1 – LP i!
The above formula has been used to generate the default quality curves for blocking probability in Atoll. These graphs are generated for a user multiplexing factor of 8 users per timeslot. Each curve represents an equivalent number of packet switched timeslots, NP. The curves depict the blocking probabilities for different number of available connections (Np) at different packet switched traffic loads (Lp) for a fixed user multiplexing factor of 8. The figure below contains all the blocking probability curves for packet switched traffic dimensioning in Atoll. The blocking probability increases with the packet switched traffic load, which implies that as the packet switched traffic increases for a given number of timeslots, the system starts to get more and more loaded, hence there is higher probability of having a temporary block flow placed in a waiting queue.
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Figure 3.10: Blocking Probability for Different Packet Switched Traffic Loads (Lp, X-axis) Reference: T. Halonen, J. Romero, J. Melero; GSM, GPRS and EDGE performance – Evolution towards 3G/UMTS, John Wiley and Sons Ltd.
3.7.2 Network Dimensioning Process The network dimensioning process is described below in detail. As the whole dimensioning process is in fact a chain of small processes that have there respective inputs and outputs, with outputs of a preceding one being the inputs to the next, the best method is to detail each process individually in form of steps of the global dimensioning process.
3.7.2.1 Network Dimensioning Engine During the dimensioning process, Atoll first computes the number of timeslots required to accommodate the circuit switched traffic. Then it calculates the number of timeslots to add in order to satisfy the demand of packet switched traffic. This is performed using the quality curves entered in the dimensioning model used. If the dimensioning model has been indicated to take all three KPIs in to account (throughput reduction factor, delay and blocking probability), the number of timeslots to be added is calculated such that: •
The throughput reduction factor is greater than the minimum throughput reduction factor,
•
Delay is less than the maximum permissible delay defined in the service properties, and
•
The blocking probability is less than the maximum allowable blocking probability defined in the service properties.
The figure below depicts a simplified flowchart of the dimensioning engine in Atoll.
Figure 3.11: Network Dimensioning Process
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On the whole, following are the inputs and outputs of the network dimensioning process:
3.7.2.1.1
Inputs • • • • • •
3.7.2.1.2
Circuit switched traffic demand Packet switched traffic demand Timeslot configurations defined for each subcell Target traffic overflow rate and Half-rate traffic ratio for each subcell Service availability criteria: minimum required throughput per user, maximum permissible delay, maximum allowable blocking probability etc. Dimensioning model parameters: Maximum number of TRXs per transmitter, dimensioning model for circuit switched traffic, number of minimum dedicated packet switched timeslots per transmitter, maximum number of TRXs added for packet switched services, KPIs to consider, and their quality curves.
Outputs • • • • • • •
Number of required TRXs per transmitter Number of required shared, circuit switched and packet switched timeslots Traffic load Served circuit switched traffic Served packet switched traffic Effective rate of traffic overflow Actual KPI values: throughput reduction factor, delay and blocking probability
3.7.2.2 Network Dimensioning Steps This section describes the entire process step by step as it is actually performed in Atoll. Details of the calculations of the parameters that are calculated during each step are described as well.
3.7.2.2.1
Step 1: Timeslots Required for CS Traffic Atoll computes the number of timeslots required to accommodate the circuit switched traffic assigned to each subcell. Atoll takes the circuit switched traffic demand (Erlangs) either user-defined or calculated in the traffic analysis and assigned to the current subcell and the maximum blocking probability defined for the circuit switched service, and computes the required number of timeslots to satisfy this demand using the Erlang B or Erlang C formula (as defined by the user). If the user-defined target rate of traffic overflow per subcell, OTarget, is greater than the maximum blocking rate defined in the services properties, it is going to be taken as the Grade of Service required for that subcell instead of the maximum blocking rate of the service. For the blocking probability GoS and circuit switched traffic demand TDC, Atoll determines the required number of timeslots TSreq. C for each subcell using formulas described below. In fact, Atoll searches for TSreq. C value until the defined grade of service is reached. For Erlang B, we have: TSreqC
TD C --------------------------- TS reqC ! GoS = TS -----------------------------reqC
k
TD C --------------k!
k=0
For Erlang C, we have: TS
reqC
TD C GoS = -----------------------------------------------------------------------------------------------------------------------------------TS –1 reqC
TD C
TS reqC
TD C + TS reqC ! 1 – -------------- TS reqC
k
TD C ---------------k!
k=0
Atoll considers the effect of half-rate circuit switched traffic by taking into account a user-defined percentage of half-rate traffic. Atoll computes the effective equivalent number of full-rate timeslots that will be required to carry the total traffic with the defined percentage of half-rate traffic. If the number of timeslots required to accommodate the full-rate circuit switched traffic is TSreq. FR, and the percentage of half-rate traffic within the subcell is defined by HR, then the effective number of equivalent full-rate circuit switched timeslots TSeff. that can carry this traffic mix is calculated by: TS eff = TS reqFR 1 – HR ------- 2
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Atoll employs this simplified approach to integrating half-rate circuit switched traffic, which provides approximately the same results as obtained by using the half-rate traffic charts.
3.7.2.2.2
Step 2: TRXs Required for CS Traffic and Dedicated PS Timeslots This stage of the network dimensioning process computes the number of TRXs required to carry the circuit switched traffic demand through the number of required timeslots calculated above and the timeslot configuration defined by the user in the network settings. Atoll distributes the number of required circuit switched timeslots calculated in Step 1 taking into account the presence of dedicated packet switched timeslots in each TRX according to the timeslot configurations. If a timeslot configuration defines a certain number of dedicated packet switched timeslots pre-allocated in certain TRXs, those timeslots will not be considered capable of carrying circuit switched traffic and hence will not be allocated. For example, if 4 timeslots have been marked as packet switched timeslots in the first TRX and Atoll computes 8 timeslots for carrying a certain circuit switched traffic demand, then the number of TRXs to be allocated cannot be 1 even if there is no packet switched traffic considered yet. The total numbers of timeslots that carry circuit switched and packet switched traffic respectively are the sums of respective dedicated and shared timeslots: TS P = TS S + TS P dedicated and TS C = TS S + TS C dedicated
3.7.2.2.3
Step 3: Effective CS Blocking, Effective CS Traffic Overflow and Served CS Traffic In this step, the previously calculated number of required TRXs is used to compute the effective blocking rate for the circuit switched traffic. This is performed by using the Erlang B or Erlang C formula with the circuit switched traffic demand and the number of required TRXs as inputs and computing the Grade of Service (or blocking probability). It then calculates the effective traffic overflow rate, Oeff.. In case of Erlang B formula, the effective rate of traffic overflow for the circuit switched traffic is the same as the circuit switched blocking rate. While in case of the Erlang C model, the circuit switched traffic is supposed to be placed in an infinitelength waiting queue. This implies that there is no overflow in this case. From this data, it also computes the served circuit switched traffic. This is the difference of the circuit switched traffic demand and the percentage of traffic that overflows from the subcell to other subcells calculated above. Hence, for an effective traffic overflow rate of Oeff. and the circuit switched traffic demand of TDC, the served circuit switched traffic STC is computed as: ST C = TD C 1 – O eff
3.7.2.2.4
Step 4: TRXs to Add for PS Traffic This step is the core of the dimensioning process for packet switched services. First of all, Atoll computes the number of TRXs to be added to carry the packet switched traffic demand. This is the number of TRXs that contain dedicated packet switched and shared timeslots. To determine this number of TRXs, Atoll calculates the equivalent average packet switched traffic demand in timeslots by studying each pixel covered by the transmitter. This calculation is in fact performed in the traffic analysis process or is userdefined in the subcells table. Knowing the traffic demand per pixel of the covered area in terms of kbps and the maximum attainable throughput per pixel (according to the C and/or C/I conditions and the coding scheme curves in the GPRS/EDGE configuration), Atoll calculates the average traffic demand in packet switched timeslots by: TD P
Timeslots
=
Traffic demand per pixel (kbps)-------------------------------------------------------------------------Throughput per pixel (kbps)
pixel
The average timeslot capacity of a transmitter is calculated by dividing the packet switched traffic demand over the entire coverage area (in kbps) by the packet switched traffic demand in timeslots calculated above. With the number of timeslots required to serve the circuit switched traffic, the timeslots required for packet switched traffic and their respective distributions according to the timeslot configurations being known, Atoll calculates the number of timeslots available for carrying the packet switched traffic demand. These timeslots can be dedicated packet switched timeslots and the shared ones. So, following the principle that shared timeslots are potential carriers of both traffic types, TS P = TS S + TS P dedicated TS C = TS S + TS C dedicated The packet switched traffic load is calculated by the formula: ST C – TS C dedicated + TD P Timeslots L P = -----------------------------------------------------------------------------------TS P The second important parameter for the calculation of Reduction Factor, Delay and Blocking Probability is the equivalent number of available timeslots for packet switched traffic, i.e. NP. This is computed by dividing the total number of timeslots
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available for carrying packet switched traffic by the number of downlink timeslots defined in the mobile terminal properties. So, NP is calculated at this stage as: TS P N P = ----------------------TS Terminal , TSTerminal is the number of timeslots that a terminal will use in packet switched calls. The number timeslots that a terminal can use in packet switched calls is the product of the number of available DL timeslots for packet-switched services (on a frame) and the number of simultaneous carriers (in case of EDGE evolution). The number of timeslots that a terminal will use in packet switched calls is determined by taking the lower of the maximum number of timeslots on a carrier for packet switched service defined in the service properties and the maximum number of timeslots that a mobile terminal can use for packet switched services (see above) on acarrier. TS Terminal = min TS Max Service TS Max TerminalType and TS Max TerminalType = TS DL TerminalType Carriers DL TerminalType Here, the min(X,Y) function yields the lower value among X and Y as result. Now, knowing the packet switched traffic load, LP, and the equivalent number of available timeslots, NP, Atoll finds out the KPIs that have been selected before launching the dimensioning process using the quality curves stored in the dimensioning model. This particular part of this step can be iterative if the KPIs to consider in dimensioning are not satisfied in the first try. If the KPIs calculated above are within acceptable limits as defined by the user, it means that the dimensioning process has acceptable results. If these KPIs are not satisfied, then Atoll increases the number of TRXs calculated for carrying packet switched traffic by 1 (each increment adding 8 more timeslots for carrying packet switched traffic as the least unit that can be physically added or removed is a TRX) and resumes the computations from Step 3. It then recalculates the packet switched traffic load, LP, and the equivalent number of available timeslots, NP. Then it recomputes the KPIs with these new values of LP and NP. If the KPIs are within satisfactory limits the results are considered to be acceptable. Otherwise, Atoll performs another iteration to find the best possible results. The calculated values of all the KPIs are compared with the ones defined in the service properties. The values for maximum Delay and Blocking probability are defined directly in the properties but the minimum throughput reduction factor is calculated by Atoll using the user’s inputs: minimum throughput per user and required availability. This calculation is in fact performed during the traffic analysis process, but since it is relevant to the dimensioning procedure, it is displayed in a column in the dimensioning results so that the user can easily compare the minimum requirement on the reduction factor KPI with the resulting one. If dimensioning is not based on a traffic analysis, the minimum throughput reduction factor is a user-defined parameter. Minimum Throughput Reduction Factor Calculation The minimum throughput reduction factor is computed using the input data: minimum required throughput per user defined in the service properties, the average throughput per timeslot deduced from the throughput curves stored in the GPRS/EDGE configuration properties for each coding scheme, the total number of downlink timeslots defined in the properties of the mobile terminal (See TS Max TerminalType defintion above) and the required availability defined in the service properties. It is at the stage of calculating the average timeslot capacity per transmitter that Atoll studies each covered pixel for carrier power or carrier-to-interference ratio. According to the measured carrier power or carrier-to-interference ratio, Atoll deduces the maximum throughput available on that pixel through the throughput vs. C or throughput vs. C/I curves of the GPRS/EDGE configuration. The throughput per timeslot per pixel TPTS, Pixel can be either a function of carrier power C, or carrier power C and the carrierto-interference ratio C/I, depending on the user-defined traffic analysis RF conditions criteria. Therefore, TP TS Pixel = f C Or C TP TS Pixel = f C and TP TS Pixel = f --- i The required availability parameter defines the percentage of pixels within the coverage area of the transmitter that must satisfy the minimum throughput condition. This parameter renders user-manageable flexibility to the throughput requirement constraint. To calculate the minimum throughput reduction factor for the transmitter, Atoll computes the minimum throughput reduction factor for each pixel using the formula:
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TP user min RF min Pixel = ---------------------------------------------------TP TS Pixel TS Terminal Once the minimum reduction factor for each pixel is known, Atoll calculates the global minimum reduction factor that is satisfied by the percentage of covered pixels defined in the required availability. The following example may help in understanding the concept and calculation method. Example: Let the total number of pixels, covered by a subcell S, be 1050. The reliability level set to 90%. This implies that the required minimum throughput for the given service will be available at 90% of the pixels covered. This, in turn, implies that there will be a certain limit on the reduction factor, i.e. if the actual reduction factor in that subcell becomes less than a minimum required, the service will not be satisfactory. Atoll computes the minimum reduction factor at each pixel using the formula mentioned above, and outputs the following results: RFmin
Number of pixels
0.3
189
0.36
57
0.5
20
0.6
200
0.72
473
0.9
23
0.98
87
So for a reliability level of 90%, the corresponding RFmin will be the one provided at least 90% of the pixels covered, i.e. 945 pixels. The corresponding value of the resulting RFmin in this example hence turns out to be 0.9, since this value covers 962 pixels in total. Only 87 of the covered pixels imply an RFmin of 0.98. These will be the pixels that do not provide satisfactory service. This calculation is performed for each service type available in the subcell coverage area. The final minimum throughput reduction factor is the highest one amongst all calculated for each service separately. The minimum throughput reduction factor RFmin value is a minimum requirement that must be fulfilled by the network dimensioning process when the Reduction Factor KPI is selected in the dimensioning model.
Figure 3.12: Minimum Throughput Reduction Factor
3.7.2.2.5
Step 5: Served PS Traffic Atoll calculates the served packet switched traffic using the number of timeslots available to carry the packet switched traffic demand. As the result of the above iterative step, Atoll always finds the best possible answer in terms of number of timeslots required to carry the packet switched traffic demand unless the requirement exceeds the maximum limit on the number of the packet switched traffic timeslots defined in the dimensioning model properties. Hence, there is no packet traffic overflow unless the packet switched traffic demand requires more TRXs than the maximum allowed
3.7.2.2.6
Step 6: Total Traffic Load This step calculates the final result of the dimensioning process, i.e. the total traffic load. The total traffic load L is calculated as:
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ST C + ST P L = --------------------------------------------------------------------------------TS C dedicated + TS P dedicated + TS S , • • • • •
STC is the served circuit switched traffic STP is the served packet switched traffic TSC, dedicated is the number of dedicated circuit switched timeslots TSP, dedicated is the number of dedicated packet switched timeslots TSS is the number of shared timeslots
3.8 Key Performance Indicators Calculation This feature calculates the current values for all circuit switched and packet switched Key Performance Indicators as a measure of the current performance of the network. It can be used to evaluate an already dimensioned network in which recent traffic changes have been made in limited regions to infer the possible problematic areas and then to improve the network dimensioning with respect to these changes. The concept of this computation is the inverse of that of the dimensioning process. In this case, Atoll has the results of the dimensioning process already committed and known. Atoll then computes the current values for all the KPIs knowing the number of required TRXs, the respective numbers of shared and dedicated timeslots and the circuit switched and packet switched traffic demands. The computation algorithm utilizes the parameters set in the dimensioning model properties and the quality curves for the throughput reduction factor, delay and the blocking probability. The following conventional relations apply: If, • • •
TSC, dedicated is the number of timeslots dedicated to the circuit switched traffic, TSP, dedicated is the number of timeslots dedicated to the packet switched traffic, TSS is the number of shared timeslots for a transmitter,
Then, the number of timeslots available for the circuit switched traffic, TSC, is defined as: TS C = TS S + TS C dedicated And the number of timeslots available for the packet switched traffic, TSP, is given by: TS P = TS S + TS P dedicated
3.8.1 Circuit Switched Traffic For each subcell, Atoll has already calculated the effective traffic overflow rate and the blocking rate during the dimensioning process. Also knowing the circuit switched traffic demand, TDC, and the number of timeslots available for circuit switched traffic, TSC, the blocking probability can be easily computed using the Erlang formulas or tables.
3.8.1.1 Erlang B Under the current conditions of circuit switched traffic demand, TDC, and the number of timeslots available for the circuit switched traffic, TSC, the percentage of blocked circuit switched traffic can be computed through: TS C
TD C -------------------- TS C ! % of blocked traffic = -------------------------TS C
k
TD C ---------------k!
k=0
In a network dimensioning based on Erlang B model, the circuit switched traffic overflow rate, OC, is the same as the percentage of traffic blocked by the subcell calculated above.
3.8.1.2 Erlang C Similarly, under the current conditions of circuit switched traffic demand, TDC, and the number of timeslots available for the circuit switched traffic, TSC, the percentage of delayed circuit switched traffic can be computed through:
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C
TD C % of traffic delayed = ---------------------------------------------------------------------------------------------------------TS – 1 C
TD C
TS
C
TD + TS C ! 1 – --------C- TS C
k
TD C --------------k!
k=0
If the circuit switched traffic demand, TDC, is higher than the number of timeslots available to accommodate circuit switched traffic, the column for this result will be empty signifying that there is a percentage of circuit switched traffic actually being rejected rather than just being delayed under the principle of Erlang C model. The circuit switched traffic overflow rate, OC, will be 0 if the circuit switched traffic demand, TDC, is less than the number of timeslots available for the circuit switched traffic, TSC. If, on the other hand, the circuit switched traffic demand, TDC, is higher than the number of timeslots available to carry the circuit switched traffic, TSC, then there will be a certain percentage of circuit switched traffic that will overflow from the subcell. This circuit switched traffic overflow rate, OC, is calculated as: TD C – TS C O C = ----------------------TD C
3.8.1.3 Served Circuit Switched Traffic The result of the above two processes will be a traffic overflow rate for the circuit switched traffic for each subcell, OC. The served circuit switched traffic, STC, is calculated as: ST C = TD C 1 – O C
3.8.2 Packet Switched Traffic Identifying the total traffic demand, TDT, (circuit switched traffic demand + packet switched traffic demand) as: TD T = TD C + TD P The following two cases can be considered.
3.8.2.1 Case 1: Total Traffic Demand > Dedicated + Shared Timeslots In the case the total number of timeslots available is less than the total traffic demand, there will be packet switched data traffic that will be rejected by the subcell as it will not be able to accommodate it. The following results are expected in this case:
3.8.2.1.1
Traffic Load The traffic load will be 100%, as the subcell will have more traffic to carry than it can. This implies that the system will be loaded to the maximum and even saturated. Hence the user level quality of service is bound to be very unsatisfactory.
3.8.2.1.2
Packet Switched Traffic Overflow In a 100% loaded, or even saturated subcell, the packet switched data calls will start being rejected because of shortage of available resources. Hence there will be a perceptible packet switched traffic overflow in this subcell, OP. This overflow rate is calculated as show below: TS C dedicated + TS P dedicated + TS S – ST C O P = 1 – ----------------------------------------------------------------------------------------------------------- 100 TD P
3.8.2.1.3
Throughput Reduction Factor The resulting throughput reduction factor for a 100% loaded or saturated subcell will be 0. Hence, the throughput perceived by the packet switched service user will be 0, implying a very bad quality of service.
3.8.2.1.4
Delay Again for a 100% loaded or saturated subcell, the delay at the packet switched service user end will be infinite as there is no data transfer (throughput = 0).
3.8.2.1.5
Blocking Probability All the data packets will be rejected by the system since it is saturated and has no free resources to allocate to incoming data packets. Hence, the blocking probability will be 100%.
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3.8.2.1.6
Served Packet Switched Traffic With the packet switched data traffic overflowing from the subcell, there will be a part of that traffic that is not served. The served packet switched data traffic, STP, is calculated on the same principle as the served circuit switched traffic: ST P = TD P 1 – O P
3.8.2.2 Case 2: Total Traffic Demand < Dedicated + Shared Timeslots In the case the total traffic demand is less than the number of timeslots available to carry the traffic, the subcell will not be saturated and there will be some deducible values for all the data KPIs. In a normally loaded subcell, the packet switched data traffic will have no overflow percentage. This is due to the fact that the packet switched data traffic is rather placed in a waiting queue than be rejected. Therefore, there will be a within limits packet switched traffic load, LP, calculated as under: ST C – TS C dedicated + TD P Timeslots L P = -----------------------------------------------------------------------------------TS P The second parameter for computing the KPIs from the quality curves of the dimensioning model is the number of equivalent timeslots available for the packet switched data traffic, NP, which is calculated in the same manner as in the dimensioning process as well: TS P N P = ----------------------TS Terminal These parameters calculated, now Atoll can compute the required KPIs through their respective quality curves.
3.8.2.2.1
Traffic Load The traffic load is computed knowing the total traffic demand and the total number of timeslots available to carry the entire traffic demand: TD T Traffic Load = --------------------------------------------------------------------------------TS C dedicated + TS P dedicated + TS S
3.8.2.2.2
Packet Switched Traffic Overflow In a normally loaded subcell, no packet switched data calls will be rejected. The packet switched traffic overflow will, therefore, be 0.
3.8.2.2.3
Throughput Reduction Factor The resulting throughput reduction factor for a normally loaded subcell is calculated through the throughput reduction factor quality curve for given packet switched traffic load, LP, and number of equivalent timeslots, NP.
3.8.2.2.4
Delay The resulting delay the subcell is calculated through the delay quality curve for given packet switched traffic load, LP, and number of equivalent timeslots, NP.
3.8.2.2.5
Blocking Probability The resulting blocking probability for a normally loaded subcell is calculated through the blocking probability quality curve for given packet switched traffic load, LP, and number of equivalent timeslots, NP.
3.8.2.2.6
Served Packet Switched Traffic As there is no overflow of the packet switched traffic demand from the subcell under consideration, the served packet switched traffic will be the same as the packet switched traffic demand: ST P = TD P
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3.9 Simulations Once you have modelled the network services and users and have created traffic maps, you can create simulations. The simulation process consists of two steps: 1. Obtaining a realistic user distribution: Atoll generates a user distribution using a Monte Carlo algorithm; this user distribution is based on the traffic database and traffic maps and is weighted by a Poisson distribution between simulations of the same group. Each user is assigned a service, a mobility type, and an activity status by random trial, according to a probability law that uses the traffic database. The user activity status is an important output of the random trial and has direct consequences on the next step of the simulation and on the network interferences. A user can be either active or inactive. Both active and inactive users consume radio resources and create interference. Finally, another random trial determines user positions in their respective traffic zone (possibly according to the clutter weighting and the indoor ratio per clutter class). 2. Modelling network regulation mechanisms: Atoll manages the GSM resources as described in "Radio Resource Management in GSM" on page 184
3.9.1 Radio Resource Management in GSM In this section, the following are explained: • •
"MSA (Mobile Station Allocation) Definition" on page 131 "GSM Simulation Process" on page 184.
3.9.1.1 GSM Simulation Process Figure 3.13 shows the GSM simulation algorithm. The specific simulation process in GSM consists of the following steps:
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Figure 3.13: GSM simulation algorithm For each simulation, the simulation process, 1. It sets initial values for the following parameters: a. Mobile transmission power is set to the maximum mobile power. b. Cell traffic loads for each MSA and transmitter are set to their average current value in the Transmitters table (one traffic load value per subcell). For each iteration k, the simulation process 2. For each circuit-switched mobile a. Determines the server and the MSA to which the circuit-switched mobile is attached. b. Determines the downlink C/(I+N) for each of these mobiles as explained in "DL Carrier-to-Interference Ratio Calculation" on page 131. c. Determines the uplink C/(I+N) for each of these mobiles as explained "UL C/I Evaluation" on page 156 d. Determines MSA codec modes in downlink as explained in "Calculations Based on C/(I+N)" on page 148 part of "CQI Calculation Without Ideal Link Adaptation" on page 147. e. Determines MSA codec modes in uplink as explained in "Codec Mode Selection" on page 159. f.
Performs the corresponding target power controls.
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See detailed information in "Servers Selection" on page 187 and "Codec Mode Assignment and DL Power Control" on page 187. 3. For each packet-switched mobile a. Determines the server and the MSA to which the packet-switched mobile is attached. b. Determines the downlink C/(I+N) for each of these mobiles as explained in "DL Carrier-to-Interference Ratio Calculation" on page 131. c. Determines the uplink C/(I+N) for each of these mobiles as explained "UL C/I Evaluation" on page 156 d. Determines MSA coding scheme in downlink as explained in "Calculations Based on C/(I+N)" on page 137 part of "Coding Scheme Selection and Throughput Calculation Without Ideal Link Adaptation" on page 137. e. Determines MSA coding scheme in uplink as explained in "Coding Scheme Selection" on page 158. f. Evaluates the number of necessary timeslots to reach the minimum downlink and uplink throughput demands (defined in the requested service) of the users randomly ranked. g. Performs the corresponding target power controls. The number of timeslots in DL and UL are obviously not linked. See detailed information in "Servers Selection" on page 187 and "Coding Scheme Assignment, Throughput Evaluation and DL Power Control" on page 188. 4. It equally shares the remaining resources to packet-switched users who did not reach their maximum throughput demands. Resources and throughputs are finally assigned to each packet-switched user. See detailed information in "Codec Mode Assignment and DL Power Control" on page 187. 5. It updates the traffic loads, Half-Rate traffic ratios, DL power control gains and DTX gains of all the subcells according to the resources in use and the total resources. See detailed information in "Subcell Traffic Loads Management" on page 189, "Half-Rate Traffic Ratio Management" on page 189, "DL Power Control Gain Management" on page 189 and "DTX DL Gain Management" on page 190. 6. It updates the UL traffic loads of all the subcells and the UL noise rises of all the TRXs according to the resources in use and the total resources. 7. Performs the convergence test to see whether the differences between the current and the new loads are within the convergence thresholds. The convergence criteria are evaluated at the end of each iteration k, and can be written as follows: Subcell i
TL DL – GSM
k
Subcell i
TL UL – GSM
k
Subcell
Max
Subcell
Subcell
i i TL – TL UL – GSM UL – GSM k All Subcell
Max
=
TRX
TRX
i i Max NR UL – GSM – NRUL – GSM k All TRX i
Subcell i
Req
, PCG DL – GSM
k – 1
Subcell i
Req
k – 1
k – 1
i
Subcell i
If TL DL – GSM
Subcell
i
=
k
Subcell
k – 1
i i PCG DL – GSM k – PCG DL – GSM All Subcell
=
k
TRX i
NR UL – GSM
Max
i
Subcell i
PCG DL – GSM
Subcell
i i TL – TL DL – GSM DL – GSM k All Subcell
=
, TL UL – GSM
TRX i
Req
and NR UL – GSM
k
are the simulation convergence
thresholds defined when creating the simulation, Atoll stops the simulation in the following cases. Convergence: Simulation has converged between iteration k - 1 and k if: Subcell i
Subcell i
TL DL – GSM TL DL – GSM k
TRX i
Subcell i
Req
Subcell i
AND PCG DL – GSM PCG DL – GSM k
Subcell i
Req
Subcell i
AND TL UL – GSM TL UL – GSM k
Req
AND
TRX i
NRUL – GSM NR UL – GSM k
Req
No convergence: Simulation has not converged even after the last iteration, i.e., k = Max Number of Iterations defined Subcell
Subcell
i
k
Subcell i
Subcell i
TL UL – GSM TL UL – GSM k
186
TRX i
Req
Subcell
i
when creating the simulation, if: TL DL – GSM TL DL – GSM
Req
TRX i
OR NR UL – GSM NR UL – GSM k
Req
.
Subcell
i
i
OR PCGDL – GSM PCG DL – GSM k
Req
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8. Repeats the above steps (from step 2.) for the iteration k+1 using the new calculated loads as the current loads until convergence.
3.9.1.2 Servers Selection For a given network, the service areas of each transmitter are evaluated in the same way than an HCS server study with 0 dB margin. In other words, each pixel, is covered by the best server of each HCS layer, assuming the received signal strength is greater than the reception threshold defined on that layer. In addition to the coverage condition above, for a given mobile distribution, a mobile might be served by a transmitter if its mobility (as assigned by Atoll at the beginning of the simulation) does not exceed the maximum speed permitted on that layer. Finally the frequency band(s) in use in the transmitter have to be supported by the user terminal. In none of these conditions are fulfilled, the mobile is rejected with the condition "No Coverage". If these conditions are fulfilled, as a result, each mobile then has a list of potential servers, each server being on a different HCS layer. For each mobile list, Atoll sorts the potential servers according to their HCS layer priority in decreasing order. On the very first iteration of the simulation, the mobile selects the highest priority transmitter. During the iterative process, if the mobile is regularly rejected from the highest priority transmitter, it will select the second highest priority transmitter and so on, until convergence. In addition, if the mobile is rejected from a layer, even after convergence, the algorithm will try to attach this mobile to a lower priority layer until no solution can be found.
3.9.1.3 Codec Mode Assignment and DL Power Control Two types of services can be assigned to users: circuit-switched and packet-switched ones. The network has been set up and dimensioned in order to first serve circuit services, and then to serve packet services with the remaining resources. When serving a circuit-switched user, depending on the computed radio conditions at the server location, a codec mode is assigned to a user. Depending on this codec mode, the user will use either an entire timeslot (any AMR, EFR or FR codec mode) or half a timeslot (HR codec mode). As explained in "GSM Simulation Process" on page 184, the resource element assigned to a mobile station is an MSA. Depending on the assigned MSA, the level of quality at the mobile might be different, and consequently, its served codec mode so as the required number of timeslots. Assuming a server is selected for each mobile, several MSAs are candidate. For each candidate MSA, a codec mode study is run, using the computed C/(I+N) and based on the user terminal and mobility (See "Calculations Based on C/(I+N)" on page 148 for more information). For each MSA, a codec mode is obtained. For each mobile, the list of candidate codec modes is saved. At the beginning of a simulation iteration, no traffic is attached to MSAs. Their load starts from 0 and is increased as traffic increases and mobiles are attached to them. For a given user, within his MSA list, the MSA having currently the lowest load is selected and, as a consequence, the load of this MSA is now increased. The effect of this mechanism results in a load balancing of MSAs within a transmitter. When MSAs are almost full, Atoll selects the MSAs the most optimised in term of timeslot occupancy. As an example, to optimise the resource allocation, a codec mode costing half a timeslot might be chosen instead of a codec mode costing an entire timeslot in the case the MSA with the lowest cost would have been chosen. This mechanism is then reproduced for all the users requesting a circuit-switched service. i
For each MSA k, the assigned codec mode i corresponds to a quality target: C I Target . Due to the radio conditions, and using k
the victim max power, a C I Max is obtained. k
i
k
i
If C I Max C I Target , no codec mode can be served and the mobile is rejected with the condition "No Service". If C I Max C I Target , the corresponding codec mode is assigned to the mobile. If the MSA is on the BCCH, no power k
control is applied. For any other TRX type, Atoll evaluates the minimum required power P Min in order to reduce the quality i
at the user’s terminal to C I Target for the assigned MSA k. The maximum allowed power reduction is set at 30 dB by default. This means that the power cannot be reduced by more than 30 dB from the initial to final C/(I+N), after power control. The power control is considered achieved when the final C/(I+N) is at less than 1 dB from i
the C I Target .
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To summarise, at this step, each circuit-switched user is assigned a MSA, a codec mode, a corresponding number of timeslots i
(0.5 or 1) and a corresponding minimum required power to get the C I Target of the served MSA. Then, if the user has been dropped as inactive at the beginning of the simulation, his corresponding number of timeslots is consumed but no DL power is considered for this specific user. Inactive users only participate in the timeslot management but do not affect DL power. Finally, if the user has been dropped as active at the beginning of the simulation, both timeslots and powers have to be considered to make him connected.
3.9.1.4 Coding Scheme Assignment, Throughput Evaluation and DL Power Control After having served the circuit traffic over one iteration, the algorithm now tries to serve packet-switched traffic. When serving a packet-switched user, depending on the computed radio conditions at the server location, a coding scheme is assigned to a user and a throughput per timeslot is obtained. Then some timeslots are assigned to each packet-switched service user in order to obtain a throughput between the min and the max DL throughput demand per user defined in the considered service properties. As explained in "MSA (Mobile Station Allocation) Definition" on page 131, the resource element assigned to a mobile station is an MSA. Depending on the assigned MSA, the level of quality at the mobile might be different, and consequently, its served coding scheme so as the required number of timeslots to get a certain throughput demand. For packet-switched traffic, the timeslot Assignment is realised in two steps. In the first step, Atoll tries to allocate the minimum throughput demand of the service. In the second step, using remaining resources (timeslots), Atoll tries to allocate more throughput up to the maximum throughput demand of the service. If a user cannot get its minimum throughput demand for insufficient number of available timeslots, the user is rejected with the condition "Resource Saturation". Assuming a server is selected for each mobile, several MSAs are candidate. For each candidate MSA, a coding scheme study is run, using the computed C/(I+N) and based on the user terminal and mobility (See "Calculations Based on C/(I+N)" on page 139 for more information). For each MSA, a coding scheme is obtained, from which we get a throughput per timeslot. As explained in "Packet Throughput and Quality Analysis: Application Throughput (kbps)" on page 144, the maximum of timeslots the user can benefit is the minimum between the number of DL timeslots defined in the selected terminal and service. Considering the minimum DL throughput demand for the service, one can estimate how many timeslots are needed to get that throughput on each MSA. Then, Atoll only keeps the MSAs for which this number of timeslots is lower than the number of timeslots supported (see above) and for which there is enough remaining timeslots. Then, for each mobile, the list of candidate coding schemes is saved. For a given user, within his MSA list, the MSA having currently the lowest load is selected and, as a consequence, the load of this MSA is now increased. In the same way than for circuit traffic, the effect of this mechanism results in a load balancing of MSAs within a transmitter. This mechanism is then reproduced for all the users requesting a packet-switched service. At this step, each packet-switched service has a coding scheme and, ideally, is supposed to be served his DL minimum throughput demand. The second step of resources allocation for packet-switched traffic is to share the remaining resources between connected users in order they get their maximum throughput demand. As an example, let’s imagine than a MSA is already occupied as follows: • •
2 TS for circuit-switched service users (3 users: 2 HR codec modes + 1 FR codec mode) 2.4 TS for packet-switched service users after the first step (2 users).
If this MSA is defined over a TCH subcell, its capacity is 8 TS. In other words, 4.4 TS have been used, and 3.6 TS remain. The two packet-switched users have obtained their minimum throughput demand. In order to reach their maximum throughput demand, the remaining TS are equally shared between the two connected users: 1.8 TS per user. If the first user can get his maximum throughput demand with only 1.5 TS, the remaining 0.3 TS will be able to be used by the user. As a consequence, this second user could benefit of 2.1 TS in order to get his maximum demand. If, finally, he only needs 1.3 TS to get this demand, 0.8 TS remain unused for that MSA. This mechanism of equally share of remaining resources is then applied for all the connected packet-switched service users over all their MSAs. j
For each MSA k, the assigned coding scheme j corresponds to a quality target: C I Target . Due to the radio conditions, and k
using the victim max power, a C I Max is obtained. k
j
If C I Max C I Target , no coding scheme can be served and the mobile is rejected with the condition "No Service".
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j
If C I Max C I Target , the corresponding coding scheme is assigned to the mobile. If the MSA is on the BCCH, no power k
control is applied. For any other TRX type, Atoll evaluates the minimum required power P Min in order to reduce the quality j
at the user’s terminal to C I Target for the assigned MSA k. The maximum allowed power reduction is set at 30 dB by default. This means that the power cannot be reduced by more than 30 dB from the initial to final C/(I+N), after power control. The power control is considered achieved when the final C/(I+N) is at less than 1 dB from i
the C I Target . To summarise, at this step, each packet-switched user is assigned a MSA, a coding scheme, a corresponding number of j
timeslots (which might not be an integer value) and a corresponding minimum required power to get the C I Target of the served MSA.
3.9.1.5 Subcell Traffic Loads Management When circuit-switched and packet-switched traffic have been served or rejected, Atoll performs an update on several parameters. The first parameter to be updated are the subcell DL and UL traffic loads. Considering that subcell loads are values which are unique per traffic pool (e.g. BCCH and TCH subcells belong to the same traffic pool because they are in charge of the same traffic area) in DL and in UL, the number of timeslots necessary to connect the traffic have to be summed up over the several MSAs over a same traffic pool. For the traffic pool TP i , the subcell DL traffic load is computed as follows:
TL TP
TS DL used
MSA TP
i DL
i = ------------------------------------------------- where the number of DL TS available for a BCCH subcell is 7 and 8 for any other subcell. TS DL available
MSA
TP i
The DL traffic load value is then assigned to all the subcells of a same traffic pool. For the traffic pool TP i , the subcell UL traffic load is computed as follows:
MSA
TL TP
i UL
TS UL used
TP
i = ------------------------------------------------- where the number of UL TS available for a BCCH subcell is 7 and 8 for any other subcell. TS UL available
MSA TP
i
The UL traffic load value is then assigned to all the subcells of a same traffic pool.
3.9.1.6 Half-Rate Traffic Ratio Management The second parameter at the end of an iteration is the Half-rate traffic ratio. This is the percentage of half-rate voice traffic in the subcell. This value is used to calculate the number of timeslots required to respond to the voice traffic demand and is evaluated per traffic pool. This value referring to voice traffic only, circuit-switched users only are taken into account in its evaluation.
HR users
MSA TP
i HR RATIO TP = ------------------------------------. users represents HR and FR circuit-switched service users. i users MSATP
MSA TP
i
i
The Half-Rate traffic ratio is then assigned to all the subcells of a same traffic pool.
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3.9.1.7 DL Power Control Gain Management At the end of each iteration, the subcell DL power control gain is evaluated by taking into account all the connected users: •
active and inactive circuit-switched service users (assuming each inactive user does not cost any DL power but only some timeslots) all packet users
•
From the minimum required powers evaluated at the end of "Codec Mode Assignment and DL Power Control" on page 187 and "Coding Scheme Assignment, Throughput Evaluation and DL Power Control" on page 188 in order to get respectively the appropriate codec modes and coding schemes without any excess of unneeded power, an average minimum required power is obtained for each mobile connected to the subcell S as follows: k
PMin TSi i
i-------------------------------S -
= P Moy
TS i
S
where i are the mobiles connected to the subcell S, over its MSAs
i
The ratio PCG
S
P Max = ---------------S (in dB), where P Max P Moy
S
is the max power of the considered subcell, represents the mean power
S
control gain, due to active and inactive users, which can be assigned to the subcell. It is essential to note that there is no power control on the BCCH and, consequently, the mean power control gain on the BCCH is 0.
3.9.1.8 DTX DL Gain Management A certain gain representing inactive circuit-switched service users has also to be evaluated. In "DL Power Control Gain Management" on page 189, the mean DL power control gain concerns both active and inactive users. The DTX gain models the fact that inactive circuit-switched users, even if they are connected to the network, do not produce the same level of interference than active circuit-switched users. From the minimum required powers evaluated at the end of "Codec Mode Assignment and DL Power Control" on page 187 in order to get the appropriate codec modes without any excess of unneeded power, an average minimum required power is obtained for each circuit-switched active mobile connected to the subcell S as follows:
ki
active
P Min
TS i
i active S
active
------------------------------------------------------------ = P Moy TS i
S active
where i active are the circuit-switched active mobiles connected to the subcell S, over
active
i active
its MSAs P Moy S The ratio -------------------------- (in dB), where P Moy P Moy S active
S
is average requested power defined in "DL Power Control Gain Management" on
page 189 above, represents the DTX gain, due to circuit-switched active users, which can be assigned to the subcell.
3.9.1.9 GSM Simulation Results At the end of the simulations, an active user can be connected in DL if: • • •
he has a serving cell assigned, For a circuit-switched (resp. packet-switched) service, he has a codec mode (resp. coding scheme) corresponding to his activity status, he is not rejected due to resource saturation.
If a user is rejected during server determination, the cause of rejection is "No Coverage". If a user is rejected because quality is too low to obtain any codec mode or coding scheme, the cause of rejection is "No Service". If a user is rejected because he cannot be allocated a sufficient number of resources to obtain its codec mode or coding scheme, the cause of rejection is "Resource Saturation," i.e., all of the cell’s resources were used up by other users. Considering only the connected traffic at the end of the GSM part of the simulation process, the main results obtained are: •
At the subcell level • • •
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Subcell traffic loads (UL and DL) DL Power control gains DTX gains
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• •
Half-rate traffic ratios
At the TRX level •
intra-technology UL noise rises
Subcell traffic loads, DL Power control gains and intra-technology UL noise rises can be used as input for GSM quality-based coverage predictions.
3.10 Automatic Neighbour Allocation The intra-technology neighbour allocation algorithm takes into account all the TBC transmitters. It means that all the TBC transmitters of the .atl document are potential neighbours. The transmitters to be allocated will be called TBA transmitters. They must fulfil the following conditions: • • • •
They are active, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone, They belong to the folder on which allocation has been executed. This folder can be either the Transmitters folder or a group of transmitters or a single transmitter.
Only TBA transmitters may be assigned neighbours. If no focus zone exists in the .atl document, Atoll takes into account the computation zone.
3.10.1 Neighbour Allocation for All Transmitters We assume a reference transmitter A and a candidate neighbour, transmitter B. When automatic allocation starts, Atoll checks following conditions: •
The distance between both transmitters must be less than the user-definable maximum inter-site distance. If the distance between the reference transmitter and the candidate neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance, which corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Appendix: Calculation of the InterTransmitter Distance" on page 195.
•
The calculation options: • Force co-site transmitters as neighbours: This option enables you to force transmitters located on the reference transmitter site in the candidate neighbour list. This constraints can be weighted among the others and ranks the neighbours through the importance field. • Force adjacent transmitters as neighbours: This option enables you to force transmitters geographically adjacent to the reference transmitter in the candidate neighbour list. This constraint can be weighted among others and ranks the neighbours through the importance field.
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Adjacency criterion: Geographically adjacent transmitters are determined on the basis of their Best Server coverages in 2G (GSM GPRS EDGE) projects. More precisely, a transmitter TXi is considered adjacent to another transmitter TXj if there exists at least one pixel of TXi Best Server coverage area TXj is the 2nd Best Server. The ranking of the adjacent neighbour transmitter increases with the number of these pixels. The figure below shows the above concept.
•
•
•
When the adjacency option is checked, adjacent cells are sorted and listed from the most adjacent to the least, depending on the above criterion. Adjacency is relative to the number of pixels satisfying the criterion.
Force adjacent layers as neighbours: If selected, Atoll adds all the transmitters adjacent across network layers to the reference transmitter to the candidate neighbour list. The weight of this constraint is always the average of the Min and Max values defined for the adjacency factor. This weight is used to calculate the rank of each neighbour and its importance. Transmitters are considered adjacent across layers if they belong to different layers and have a coverage overlap of at least one pixel. Force symmetry: This option enables user to force the reciprocity of a neighbourhood link. Therefore, if the reference transmitter is a candidate neighbour of another transmitter, the latter will be considered as candidate neighbour of the reference transmitter. If the neighbours list of a transmitter is full, the reference transmitter will not be added as a neighbour of that transmitter and that transmitter will be removed from the reference transmitter’s neighbours list. You can force Atoll to keep that transmitter in the reference transmitter’s neighbours list by adding the following option in the Atoll.ini file: [Neighbours] DoNotDeleteSymmetrics = 1
• • •
Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may force/forbid a transmitter to be candidate neighbour of the reference transmitter. Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, the existing neighbours are kept.
If the Use Coverage Conditions check box is selected, there must be an overlapping zone ( S A S B ) with a given cell edge coverage probability. Otherwise, only the distance criterion is taken into account. The overlapping zone ( S A S B ) is defined as follows: •
•
192
SA is the area where the received signal level from transmitter A is greater than a minimum signal level. SA is the coverage area of reference transmitter A restricted between two boundaries; the first boundary represents the start of the handover area (best server area of A plus handover margin named “handover start”) and the second boundary shows the end of the handover area (best server area of A plus the margin called “handover end”). SB is the coverage area where the candidate transmitter B is the best server.
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SA SB - 100 ) if the option “Take into account Covered Area” is Atoll calculates either the percentage of covered area ( ----------------SA selected, or the percentage of traffic covered on the overlapping area S A S B for the option “Take into account Covered Traffic”. Then, it compares this value to the % minimum covered area (minimum percentage of covered area for the option “Take into account Covered Area” or minimum percentage of covered traffic for the option “Take into account Covered Traffic”). If this percentage is not exceeded, the candidate neighbour B is discarded. The coverage condition can be weighted among the others and ranks the neighbours through the importance field (see number 4 below).
Figure 3.14: Overlapping Zones Atoll uses traffic map(s) selected in the default traffic analysis in order to determine the percentage of traffic covered in the overlapping area.
•
The importance values are used by the allocation algorithm to rank the neighbours according to the allocation reason, and to quantify the neighbour importance.
Atoll lists all neighbours and ranks them by importance value so as to eliminate some of them from the neighbour list if the maximum number of neighbours to be allocated to each transmitter is exceeded. If we consider the case for which there are 15 candidate neighbours and the maximum number of neighbours to be allocated to the reference transmitter is 8. Among these 15 candidate neighbours, only 8 (having the highest importances) will be allocated to the reference transmitter. In the Results part, Atoll only displays the transmitters for which it finds new neighbours. For these transmitters, it provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each transmitter. In addition, it indicates the importance (in %) of each neighbour and the allocation reason. Therefore, a neighbour may be marked as exceptional pair, co-site, intra-HCS and inter-HCS adjacent, coverage or symmetric. For neighbours accepted for co-site, intra-HCS or inter-HCS adjacency and coverage reasons, Atoll displays the percentage of area meeting the coverage conditions (or the percentage of covered traffic on this area) and the corresponding surface area (km2) (or the traffic covered on the area in Erlangs), the percentage of area meeting the adjacency conditions and the corresponding surface area (km2). Finally, if cells have previous allocations in the list, neighbours are marked as existing.
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By default, the automatic neighbour allocation compares the defined Max intersite distance with the effective inter-transmitter distance. As a consequence, there can be cases where the real distance between assigned neighbours is higher than the Max inter-site distance, because the effective distance is smaller. You can force Atoll to compare the Max inter-site distance with the real inter-site distance by adding the following lines in Atoll.ini: [Neighbours] RealInterSiteDistanceCondition=1
•
By default, the neighbour importance calculated with respect to distance is based on the global Max inter-site distance setting for all neighbour candidates. As a consequence, there can be cases where the calculated importance is different when the global Max inter-site distance is modified. To avoid that, you can force Atoll to prioritise the individual distances between reference transmitters and their respective neighbour candidates by adding the following lines in Atoll.ini: [Neighbours] CandidatesMaxDistanceInImportanceCalculation=1
3.10.2 Neighbour Allocation for a Group of Transmitters or One Transmitter In this case, Atoll allocates neighbours to: • • •
TBA transmitters, Neighbours of TBA transmitters marked as exceptional pair, intra-HCS or inter-HCS adjacent and symmetric, Neighbours of TBA transmitters that satisfy coverage conditions.
Automatic neighbour allocation parameters are described in "Neighbour Allocation for All Transmitters" on page 191.
3.10.3 Neighbour Importance Calculation The neighbour importance depends on the distance from the reference transmitter and on the neighbourhood cause (cf. table below); this value varies between 0 and 100%. Neighbourhood cause
When
Importance value
Existing neighbour
Only if the Delete existing neighbours option is not selected and in case of a new allocation
Existing importance
Exceptional pair
Only if the Force exceptional pairs option is selected
100 %
Co-site transmitter
Only if the Force co-site cells as neighbours option is selected
Importance Function (IF)
Adjacent transmitters
Only if the Force intra-HCS adjacents as neighbours option is selected
Importance Function (IF)
Adjacent layer
Only if the Force inter-HCS adjacents as Neighbours option is selected
Importance Function (IF)
Neighbourhood relationship that fulfils coverage conditions
Only if the % minimum covered area is exceeded
Importance Function (IF)
Symmetric neighbourhood relationship
Only if the Force neighbour symmetry option is selected
Importance Function (IF)
Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined using the Importance Function (IF). The IF considers the following factors for calculating the importance: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Appendix: Calculation of the Inter-Transmitter Distance" on page 195.
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d max is the maximum distance between the reference transmitter and a possible neighbour. • • •
The co-site factor (C): a Boolean, The adjacency factor (A): the percentage of adjacency, The overlapping factor (O): the percentage of overlapping.
The minimum and maximum importance assigned to each of the above factors can be defined. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
30%
Adjacency factor (A)
Min(A)
30%
Max(A)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The Importance Function is evaluated as follows: Neighbourhood cause
Importance Function
Resulting IF using the default values from the table above
Coverage
Min(O)+Delta(O){Max(Di)(Di)+(100%Max(Di))(O)}+Min(Di)+Delta(Di)(Di)
10%+20%{10%(Di)+90%(O)}+1%+9%(Di)
Adjacent layer
(Min(A)+Max(A))/2
45%
Adjacent transmitters
Min(A)+Delta(A){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
30%+30%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Co-site transmitters
Min(C)+Delta(C){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
60%+40%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Delta(X)=Max(X)-Min(X) • •
•
•
Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours, adjacent neighbours, and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes. The default value of Min(O) = 1% ensures that neighbours selected for symmetry will have an importance greater than 0%. With a value of Min(O) = 0%, neighbours selected for symmetry will have an importance field greater than 0% only if there is some coverage overlapping.
3.10.4 Appendix: Calculation of the Inter-Transmitter Distance Atoll takes into account the real distance ( D in m) and azimuths of antennas in order to calculate the effective intertransmitter distance ( d in m). d = D 1 + x cos – x cos x = 0.3% so that the maximum D variation does not exceed 1%.
Figure 3.15: Inter-Transmitter Distance Computation
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The formula above implies that two cells facing each other will have a smaller effective distance than the real physical distance. It is this effective distance that will be taken into account rather than the real distance.
3.11 AFP Appendices 3.11.1 The AFP Cost Function The notations listed hereafter are used to describe the cost function: • • • • •
TRG: TRGs: : g : ARFCN:
•
2
ARFCN
•
x :
•
A i g :
Group of TRXs Set of all the TRGs If and only if Size of any group g Set of all the frequencies :
Set of all the subsets of frequencies The largest integer
x
Number of times a group g 2
ARFCN
is assigned to TRGi in the assignment A
For example: •
When i is NH, A i g = 1 g is a single member group containing one of the frequencies assigned at TRGi. If |g| is not 1 or if g does not contain a frequency assigned at i, then A i g = 0 .
•
When i is BBH, A i g can be either 0 or equal to the number of TRXs in TRGi. A i g = Number of TRXs in TRGi g is the set of frequencies assigned to TRXs of TRGi. (|g| = number of TRXs in TRGi). When we talk about "TRXs of i using g", and in the case of BBH, then there are |g| such virtual TRXs, each using the entire group g and having a virtual MAIO [0, |g| - 1].
•
When i is SFH, A i g must be less than or equal to the umber of TRXs in TRGi. A i g = n g is the set of frequencies assigned to n TRXs of TRGi. We assume all the groups assigned to TRGi to have the same length.
• •
TSi: TLi:
Number of timeslots available for each TRX in TRGi Traffic load of TRGi (calculated or user-defined)
TL i = #Erlangs of a single TRX in TRGi divided by TSi • • • • •
TSUi: CFi: QMINi: PMAXi: REQi:
Downlink timeslot use ratio (due to DTX) at TRGi Cost factor of TRGi (AFP Weight) Minimum required quality (in C/I) at TRGi Percentage permitted to have quality lower than QMINi at TRGi Required number of TRXs at TRGi
A communication uses the group g in TRGi if its mobile allocation is g. The probability to be interfered is denoted by P i i' g A (i’ is the TRX index). Different TRX indexes may have different MAIOs. P i i' g A is a function of the whole frequency assignment. The precise definition of the term “to be interfered” is provided afterwards. The probability penalty due to violating a separation constraint is P i i' g A . It is a function of the whole frequency assignment as well. The term “Atom” will be used in the following context: For two TRGs, i and k, ATOM i ATOM k i and k are synchronised, have the same HSN, the same MAL length and the same hopping mode. NH TRGs or BBH TRGs are always in separate atoms. If two TRGs interfere but are not in the same atom, these can be taken as unsynchronised. The quality of unsynchronised TRGs is a function of all possible frequency combinations. For synchronised TRGs, pairs of frequencies emitted at the same time are known.
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3.11.1.1 Cost Function The Atoll AFP cost function is a TRX based cost and not an interference matrix entry based cost. It counts the impaired traffic of the network TRXs in weighted Erlangs. The cost function is reported to the user during the AFP progress with the help of its 5 components: mis , sep , comp , corr and dom . = mis + sep + comp + corr + dom , mis represents the missing TRX cost component sep represents the separation component comp represents the additional cost component (interference, cost of changing a TRX) corr represents the corrupted TRX cost component dom represents the out-of-domain frequency assignment cost component mis =
MIS_TRX i TL i CF i TS i
CORR_TRX i TL i CF i TS i
DOM_TRX i TL i CF i TS i
i TRGs
corr =
i TRGs
dom =
i TRGs
sep
= i TRGs
comp
ARFCN g2 i' TRXs of i using g
= i TRGs
' i i' g A TL i CF i TS i
ARFCN g2 i' TRXs of i using g
'' i i' g A TL i CF i TS i
In the above equations, •
i’ is the TRX index belonging to 0 1 ... A i g – 1 .
•
MIS_TRX i is the number of missing TRXs for the subcell i.
MIS_TRX i = MAX 0 REQi –
g2
• • • • •
A i g
ARFCN
is the cost value for a missing TRX. This value can vary between 0 and 10. The default cost value is set to 1 and can be modified in the AFP module properties dialogue. CORR_TRX i is the number of corrupted TRXs for the subcell i. is the cost value of a corrupted TRX. This value can vary between 0 and 10. The default cost value is set to 10 and can be modified in the AFP module properties dialogue. DOM_TRX i is the number of TRXs, for the subcell i, having out-of-domain frequencies assigned. is the cost value of a TRX with out-of-domain frequencies assigned. This value can vary between 0 and 1. The default cost value is set to 0.5 and can be modified in the AFP module properties dialogue. And, as mentioned earlier, a virtual TRX is considered in case of BBH. If i’ is valid, the algorithm evaluates the cost of a valid TRX. This cost has two components, ' i i' g A and '' i i' g A .
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' i i' g A is the separation violation probability penalty.
•
'' i i' g A is complementary probability penalty due to interference and the cost of modifying a TRX.
©Forsk 2015
If the option “Take into account the cost of all the TRXs” available in the AFP module properties dialogue is selected, then, ' i i' g A = P' i i' g A and '' i i' g A = P'' i i' g A Or if the option “Do not include the cost of TRXs having reached their quality target” available in the AFP module properties dialogue is selected, the algorithm compares P' i i' g A + P'' i i' g A with the quality target specified for i, P MAX : If
P' i i' g A + P'' i i' g A P MAX , Then ' i i' g A = P' i i' g A and '' i i' g A = P'' i i' g A .
Otherwise, Both ' i i' g A and '' i i' g A will be equal 0. P' i i' g A is the same as ' i i' g A (separation violation probability penalty) and P'' i i' g A the same as '' i i' g A (complementary probability penalty due to interference and the cost of modifying a TRX) in most cases. These are explained in detail in the next sections.
3.11.1.2 Cost Components Separation violation and interference cost components are described hereafter. Parameters considered in the cost function components can be fully controlled by the user. Some of these parameters are part of the general data model (quality requirements, percentage of interference allowed per subcell), while others (such as separation costs and diversity gains) can be managed through the properties dialogue of the Atoll AFP module.
3.11.1.2.1
Separation Violation Cost Component The separation violation cost component is evaluated for each TRX. Estimation is based on costs specified for the required separations. Let SEP_CONSTR i k denote the required separation constraint between TRGi and TRGk. Let Cost s z denote the user defined separation penalty for a required separation “s” and actual separation “z”. SEP i k v is used instead of Cost SEP_CONSTR
i k z
as
abbreviation. The AFP module properties dialogue takes probability percentages as inputs while this document deals in probability values.
ii'kgg'k' is considered to be the effect of a separation violation on the i' th TRX of TRGi assigned the group g, caused by the k' th TRX of TRGk assigned the group g' . denotes the overall weight of the separation violation cost component. This value can be between 0 and 1, set to 1 by default. It can be modified in the AFP module properties dialogue. ik represents the weight of the specific separation constraint between i and k. This specific weight depends on the type of separation violation and follows the following priority rule: 1. Exceptional pairs 2. Co-transmitters 3. Co-site 4. Neighbours For example, if a pair of subcells are co-site and neighbours at the same time, they will be considered as co-site because higher priority. Hence, ik of these subcells will be the weight of co-site relations. If only a neighbour relation exists between two
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subcells, then ik will be further weighted by the neighbour relation importance. The value of ik remains between 0 and 1. The default weights of each type of separation are available in the Separation cost tab. If ATOM i ATOM k
SEP i k
f – f'
fg f' g'
Then ii'kgg'k' = ik ----------------------------------------- , which is same for all values of k. g g' If ATOM i = ATOM k
Then ii'kgg'k' = ik
SEP
i k g – g' f_n 0 1 ... F_N – 1 -----------------------------------------------------------------------------
F_N
In the above equations, F_N g is the number of frames in the MAL g. F_N g = g . Since F_N g = F_N g' , we shortly denote the two as F_N .
Let f_n denote the instantaneous frame number from 0 to F_N . While = f_n + MAIO A And = f_n + MAIO A
th
i g i'
k g' k'
modulo F_N and g is the frequency in g,
modulo F_N and g' is the
th
frequency in g’.
In addition, frequencies belonging to a MAL with a low fractional load, and breaking a separation constraint, should not be weighted equally as in a non-hopping separation breaking case. Therefore, the cost is weighted by an interferer diversity gain. 1 Gˆ i k g g' = ---------------------------------------------------------- 0.1 SEP_GAIN i k g g' 10 The separation gain, denoted by SEP_GAIN i k g g' is basically a function of the MAL length (and, of course, of the hopping mode). With frequency hopping, the effects of DTX and traffic load become more significant (due to the consideration of the average case instead of the worst case). For this reason, it is possible to consider these effects in SEP_GAIN i k g g' through the relevant option available in the Advanced tab of the AFP module properties dialogue. Without this option, the SEP_GAIN i k g g' is: SEP_GAIN i k g g' = I_DIV g I_DIV g is the user defined interferer diversity gain (dB) for a given MAL length. It is used in P i i' g A definition as well. On the other hand, if this option is selected, the SEP_GAIN i k g g' becomes, 2 + ASYN_GAIN i k g' SEP_GAIN i k g g' = I_DIV g +0.5 TSU_GAIN k min 10 4 + 2 + I_DIV g ----------------------------------------------------------------- 4 1 TSU_GAIN k = log 10 -------------------------- , TL k TSU k And ASYN_GAIN i k g' =
0 I_DIV( g'
if ATOM(i) = ATOM(k) Otherwise
More than one separation violations may exist for a TRX. Many “small” Gˆ i k g g' and ' ii'kgg' have to be combined to form one cost element, the P' i i' g A . This is done through iterating over all violating assignments and by summing up an equivalent to the probability of not being violated while considering each separation violation as an independent probability event. This sum is naturally limited to 100% of the TRX traffic, and is given by,
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1 – ii'kgg'k' Gˆ i k g g' 1 – P' i i' g A = k TRGs ARFCN g' 2 k' TRXs of k using g'
In the above formula, if k = i , then k' i' , so that interference with itself is not taken into account.
3.11.1.2.2
Interference Cost Component The interference cost component is evaluated for each TRX. Its estimation is based on interference histograms calculated for pairs of subcells. In addition, it takes into account frequency and interferer diversity gains and models frequency hopping and gain due to DTX. Interference histograms are described in User Manual (GSM GPRS EDGE project management, GSM GPRS EDGE network optimisation, GSM GPRS EDGE generic AFP management). Interference histograms can also be exported to files. For further description, refer to "Interference" on page 205. When estimating P'' i i' g A , the following problems are encountered: • •
The QMINi C/I quality indicator corresponds to the accumulated interference level of all interferers while the C/I interference histograms correspond to pair-wise interferences. Both QMINi and the histograms correspond to a single frequency. In case of a MAL containing more than one frequencies, interferences on several different frequencies of a MAL must be combined. This estimation, presented below, is the simplest possible as it solves the first problem by linear summation and truncation at the value of 1 and it solves the second problem by averaging and adding the two diversity gains:
•
F_DIV g , the frequency diversity gain, and
•
I_DIV g , the interferer diversity gain.
Hereafter, denotes the global weight of interference cost component. This value can vary between 0 and 1 and is set to 0.35 by default, which can be modified in the AFP module properties dialogue. Let F_N g be the number of frames in the MAL g. F_N g = g . Let f_n denote the instantaneous frame number from 0 to F_N . Let MAIO A
k g' j
be the j’th MAIO of A k g' , j is one of the 0 1 ... A k g' – 1 TRXs.
The value of MAIO A
is one of 0 1 ... g'
k g' j
If TRGk is NH, then MAIO A
k g' j
If TRGk is BBH, then MAIO A
k g' j
= 0. = j .
As said earlier, in case of BBH, we consider g' virtual TRXs, the jth TRX has the MAIO j. Let g i be the ith frequency in the group g. Similar to the definition of ii'kgg'k' , ' ii'kgg'k' is defined as an interference event. ' ii'kgg'k' is the effect interference on the i' th TRX of TRGi assigned the group g, caused by the k' th TRX of TRGk assigned the group g' . If ATOM i ATOM k
Then ' ii'kgg'k' =
f g f' g'
C Probability ----- Q_UB i k f f' I ik -------------------------------------------------------------------------g g'
Q_UB i k f f' = QMIN i – If ATOM i = ATOM k
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f – f' ADJ_SUP + INTERF_GAIN i k g g'
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Then, Since F_N g = F_N g' , these are both represented by F_N .
ii'kgg'k'
C Probability ----- Q_UB i k f f' I ik - = ------------------------------------------------------------------------F_N f_n 0 1 ... F_N – 1
, f = g , f' = g' , = f_n + MAIO A = f_n + MAIO A
i g i'
modulo F_N ,
k g' k'
modulo F_N ,
Q_UB i k f f' = QMIN i –
f – f' ADJ_SUP + INTERF_GAIN i k g g'
Therefore, we have, P'' i i' g A = 1 – 1 – P' i i' g A
1 – ii'kgg'k' – P' i i' g A
k TRGs ARFCN g' 2 k' TRXs of k using g'
In the above formula, if i = k , then k' i' , so that interference with itself is not taken into account. The sum is limited to 100% of the TRX traffic. INTERF_GAIN i k g g' is quite similar to SEP_GAIN i k g g' . The only difference is the frequency diversity gain, F_DIV g , added to SEP_GAIN i k g g' .
3.11.1.2.3
I_DIV, F_DIV and Other Advanced Cost Parameters When combining interference effects (or separation violation effects) on different frequencies belonging to a MAL, the following considerations should be taken into account: 1. Non-linearity of Frame Error Rate (FER) with respect to average C/I conditions and MAL length. 2. Interference Diversity Gain. This factor represents that the effect of average negative effects over user geographic location are directly proportional to the MAL length. 3. Frequency Diversity Gain. This factor models the gain due to diversity of multi-path effects and should be applied to the interference cost component only. 4. The fact that long MALs with synthesized hopping permit discarding the worst case estimation and include a gain due to DTX and low traffic load at the interferer end. The Advanced properties tab shown in the figure below facilitates modelling these effects.
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Figure 3.16: The Advanced tab of the AFP module Properties dialogue The Interference Diversity Gain table lists the values of I_DIV provided as a functions of MAL length. This gain is applied to the interference cost component and to the separation constraint violation cost component. Therefore, it provides a means to model the non-linear FER effects and interference diversity both. The default values in this table correspond to the curve y = 2 log 10 x . This equation generates values somewhat lower than empirical best-found values (this is because we prefer a slightly pessimistic cost function to be on the safe side). The other table contains the F_DIV values, which are the same as the I_DIV values by default.
3.11.2 The AFP Blocked Traffic Cost This section provides additional information on the AFP cost components used for the optimisation of the number of TRXs. This optimisation is performed for each traffic pool in the network. In most cases, the traffic pool is equivalent to a transmitter and corresponds to the BCCH and TCH subcells. In more complex cases, a traffic pool may include additional subcells, and more than one traffic pools may exist per transmitter. The cost component described below, and the recalculation of traffic loads, is only used when the AFP performs the oprimisation of the number of TRXs. The notations listed hereafter are used for the description.
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•
{BCCH, TCH(1), TCH(2), …, TCH(n)}:
• • • • •
{d(0), d(1), d(2), …, d(n)}: {ts(0), ts(1), ts(2), …, ts(n)}: {L(0), L(1), L(2), …, L(n)}: {CF(0), CF(1), CF(2), …, CF(n)}: CS (Erlangs):
•
PS (Data Timeslots):
• •
{nb(0), nb(1), nb(2), …, nb(n)}: {HR(0), HR(1), HR(2), …, HR(n)}:
Subcells of a traffic pool. For concentric cells, at least two traffic pools exist per transmitter. The BCCH subcell may not always be part of the pool’s TRX types. Number of required TRXs of each TRX type in the pool. Numbers of traffic timeslots. Traffic loads. AFP cost factors. Overall circuit-switched traffic demand of the traffic pool (Subcells table or traffic analysis results). Overall packet-switched traffic demand of the traffic pool (Subcells table or traffic analysis results). If CS or PS is less than 1, its value is set to 1 in order to avoid working with transmitters carrying no traffic. Number of TRXs in the frequency plan. TCH HR use ratios.
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3.11.2.1 Calculation of New Traffic Loads Including Blocked Traffic Loads During the optimisation of the number of TRXs, traffic loads are calculated in order to determine the blocked traffic loads BL nb . The blocked traffic load is then multiplied by the AFP cost weight and the number of timeslots to calculate the blocked traffic cost. Without the optimisation of the number of required TRXs, the network’s weighted Erlangs are calculated as follows: n
WE =
d i ts i L i CF i i=0
With the optimisation of the number of TRXs, the network’s weighted Erlangs are calculated as follows: n
WE =
nb i ts i BL nb + L nb CF i i=0
BL nb and L nb represent the load estimation and the blocked load estimation of the AFP. They are calculated at traffic pool level for the vector {nb(0), nb(1), nb(2), …, nb(n)} as follows: HR PS + CS 1 – ------------- 2 BL nb + L nb = --------------------------------------------------------------n Max 1 nb i ts i i=0
HR
n
= Max i = 0 HR i
BL nb is determined from the above equation once L nb is known. L nb is obtained from the Erlang B equation applied to the traffic pool demand and the total number of timeslots (TTS): n nb i ts i - TTS = Max 1 ---------------------------- HR i = 0 1 – ------------2
The Max() function above gives 1 timeslot when there is no TRX. P Blocking = ErlangB CS TTS The above equations give the number of served circuit-switched timeslots (SCS): HR CS 1 – P SCS = 1 – ------------Blocking 2 The number of served packet-switched timeslots (SPS) is obtained as follows: n SPS = Min PS Max 1 nb i ts i – SCS i=0
L nb is given by: SCS + SPS L nb = -------------------------------------------------------------n Max 1 nb i ts i i=0
BL nb is given by: HR PS + CS 1 – ------------ 2 BL nb = --------------------------------------------------------------- – L nb n Max 1 nb i ts i i=0
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Once L nb and BL nb are known, L nb replaces TLi in the cost function (See "The AFP Cost Function" on page 196), and BL nb is used to generate a new cost component, the blocked Erlangs of the pool: n
nb i ts i BL nb CF i i=0
3.11.2.2 Recalculation of CS and PS From Traffic Loads In earlier versions, the detailed traffic demand information is not available. In order to guide the AFP to generate it from the loads, the following two equations with three variables must be solved. The equations are solvable due to the monotone nature of the Erlang B function. Inputs for a given traffic pool: • •
{d(0), d(1), d(2), …, d(n)}: L:
Number of required TRXs of each TRX type in the pool Traffic load
•
TTS' :
n d i ts i TTS' = Max 1 ---------------------------- HR i = 0 1 – ------------2
•
MB:
Maximum blocking rate (between 0 and 1).
The ratio of packet-switched demand is given by: PS R = ---------------------------------------------------HR PS + CS 1 – ------------ 2 Here, we assume that a traffic load of 1 is generated by a demand of (1+MB)*TTS’ which generates a blocking rate of MB. In other words, the ratio is calculated so that the worst case blocking rate is BM, giving a load of 1. The following equations are solved to find PS’, CS’, and R’, which are calculated for a traffic load of 1. MB = ErlangB CS' TTS' PS' R' = ------------------------------------------------------HR PS' + CS' 1 – ------------ 2 PS' - + CS' 1 + MB TTS' = --------------------------HR 1 – ------------ 2 When the traffic load of a pool is not 1, PS is different from PS’ and CS is different from CS’. Here, however, we assume that R’ = R. This assumption implies that R is more or less the same as MB for big traffic pools and considerably larger than MB for smaller pools. The following equations are solved to find PS, CS, and R, which are calculated for the actual traffic loads. PS R = ---------------------------------------------------HR PS + CS 1 – ------------- 2 P Blocking = ErlangB CS TTS' HR CS 1 – P SCS = 1 – ------------Blocking 2 n SPS = Min PS Max 1 d i ts i – SCS i=0
n
SCS + SPS =
d i ts i L i i=0
The above five equations are solved to get the values of the five variables PS, PC, P Blocking , SCS, SPS, and calculate the cost.
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3.11.2.3 Testing the Blocked Cost Using Traffic Analysis As long as the conditions below hold truw, the blocked cost calculation in the AFP and the effective overflow calculation in the KPI calculation and dimensioning use the same algorithm. The conditions are: • • • • • •
The AFP cost factors are 1, The HR ratios are the same within the subcells of a traffic pool, The dimensioning model is based on Erlang B, The timeslot configurations are the default ones, There exists at least one TRX in the traffic pool (and at least one Erlang of traffic), All transmitters belong to the same HCS Layer.
L nb Effective Overflow rate = 1 – -------------------------------------L nb + BL nb Output: New values for CS and PS.
3.11.3 Interference This appendix provides a high-level overview of interference taken into account by the AFP.
3.11.3.1 Using Interferences If interferences are to be taken into account by the AFP, they must be calculated or imported beforehand. In order to do this, the user should previously decide to take interferences into account (enabling the loading of all the potential interferers). Otherwise, Atoll does not allow performing their computation by disabling the histogram part in the corresponding dialogue.
3.11.3.2 Cumulative Density Function of C/I Levels For each [interfered subcell, interfering subcell] pair, Atoll calculates a C/I value on each pixel of the interfered subcell service area (as if the two subcells share the same channel). Then, Atoll integrates these C/I values to determine a C/I distribution and transforms this distribution function into a cumulative density function in the normal way. In Atoll, both the IMco and IMadj are represented by this Cumulative Density function This implies that each query for the probability to have C/I conditions worse than X dB requires a single memory access: the co-channel interference probability at X dB. In order to deduce the adjacent interference probability value, Atoll looks up the cumulative density function at the value corresponding to X - Y dB, Y dB being the adjacency suppression value. The following example may be helpful in further clarifying this concept: Example: Let [TX1, BCCH] and [TX2, BCCH] be the interfered and interfering subcells respectively. The service areas for both have been defined by Best Server with 0 dB margin. The interference probability is stated in percentage of interfered area.
Figure 3.17: The cumulative density of C/I levels between [TX1, BCCH] and [TX2, BCCH] In this case, we observe that the probability for C/I (BCCH of TX2 effecting the BCCH of TX1) being greater than 0 is 100% (which is normal because TX1 is the Best Server). The probability of having a C/I value at least equal to 31 dB is 31.1%. For a required C/I level of 12 dB on the BCCH of TX1, the interference probability is 6.5% (as this requirement is fulfilled with a probability of 93.5%).
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The subcell power offset does not enter the calculation results in the .clc file. It is added later by the AFP interface. On the other hand, its influence on the subcell service zone is taken into account in the .clc file.
3.11.3.3 Precise Definition Pci v n C_I is defined to be the probability of a communication (call) occupying a timeslot in subcell v (victim) to have C/ I conditions of C_I with respect to a co-channel interference from the BCCH TRX of cell n (neighbour). We assume C_I values to be discrete and in dB. CDF(Pci) is the cumulative density function of Pci: CDF Pci v n C_I =
Pci v n x
xC I
3.11.3.4 Precise Interference Distribution Strategy Why does Atoll calculate and maintain precise interference distributions, while the most common solution (used by most other tools) is rather to compress the information into two values: the co-channel and adjacent-channel interference probabilities? The reason is simply that it, • • •
3.11.3.4.1
improves the AFP result, introduces very little (or no) overhead, and creates more generic interference information.
Direct Availability of Precise Interference Distribution to the AFP In the presence of frequency hopping, and when one or more frequencies are common (or adjacent) in two interfering MAL sequences, the hopping gain depends on following factors: • • • •
the MAL length, the traffic load on the interferer TRX, DTX level, and the number of common (and adjacent) frequencies in the two MALs.
All these factors cannot be pre-calculated since it is the AFP that determines the MAL length and the MAL frequencies.
3.11.3.4.2
Efficient Calculation and Storage of Interference Distribution In the innermost loop of the calculation process Atoll increments a counter each time a C/I level has a certain value. In the case of a two-entry IM, there are only two counters for each [interfered, interferer] pair. In the case of precise distribution information, there are about 40 counters per pair. In both cases, the number of operations is the same: one increment of an integer value. Once Atoll finishes the counting for an [interfered, interferer] pair, it compresses the information from the counters to a Cumulative Density Function (CDF) representation. In this way, access to interference probability at a certain level is instantaneous. Thus, the only overheads are the read / write times to the files and the memory occupation at running time. These two overheads are negligible and do not affect the calculations, the heaviest part of the task.
3.11.3.4.3
Robustness of the IM By having precise C/I distributions calculated and exported, the user is free to change the following settings without the need for recalculating their interference distributions: 1. Quality requirements of network elements (required C/I, % Probability Max, …), 2. C/I weighting (the interference levels above and below the C/I target), 3. Separation requirements and/or neighbour relations, 4. Hopping gain values, DTX activities, traffic load levels, HSNs, synchronisation information, 5. Any frequency assignment setting (MAL length directives, frequency domains, assignment strategies, number of required TRXs, cost function parameters, …), or 6. Remove equipment By not mixing any of the elements above, the interference information keeps its original probability units and is easier to check and validate. Therefore, the user spends less time on interference recalculations than in the case of a two-entry matrix ( “everything” is included).
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3.11.3.5 Traffic Load and Interference Information Discrimination Atoll maintains the traffic load separate from the interference information. The reasons for implementing this strategy are explained here. Let us look at the possible alternatives to this strategy: 1. The mixed option: The interference information contains the traffic information as well. In this way, each IM entry will contain the quantity of traffic interfered if a co-channel / adjacent channel reuse exists. 2. The separated option: The AFP has separate access to traffic load information and to interference probabilities (As in Atoll). Knowing the difference between the two alternative solutions explains why the second strategy has been opted for for Atoll. However, in detail, this has been done because: • • • • • •
Option 2 is a superset that contains option 1. But option 1, being a subset, does not contain option 2 (i.e. once the information are mixed they cannot be separated). It does not create any overhead (the size of the additional information is negligible compared to the size of the IM). It helps keeping the unit definitions simpler. It is facilitates merging IMs with different traffic units. The traffic information can be used for weighting the separation violation component. The traffic load can be used in deciding whether a TRX can be left uncreated. For example, if there are too many TRXs at a site and the user wishes that the AFP remove one of them, in order to be able to not violate site constraints, the AFP must know the traffic loads in order to choose a low load TRX to be removed.
•
The gain introduced by the traffic load of the interferer depends on the hopping mode and the MAL length. Incorporating this gain in the IM (as a result of the mixed option) means that the IMs become hopping-mode and MALsize dependent. This is a bad idea since the AFP should be able to change the MAL. And the user should be able to change the hopping mode without recalculating the IM. In addition, an IM calculated externally to Atoll, with a nonhopping BCCH can be used for the hopping TCH.
A third option also exists. Though, this option is so practically useless due to its inefficiency. It consists in mixing IM and traffic but still keeping the traffic in its isolated form. This is again a bad idea because of the unit definition and the variety of IM sources. It involves less benefits than the option chosen in Atoll.
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Chapter 4 UMTS HSPA Networks This chapter covers the following topics: •
"General Prediction Studies" on page 211
•
"Definitions" on page 214
•
"Simulations" on page 225
•
"UMTS HSPA Prediction Studies" on page 284
•
"Automatic Neighbour Allocation" on page 312
•
"Primary Scrambling Code Allocation" on page 319
•
"Automatic GSM-UMTS Neighbour Allocation" on page 329
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4 UMTS HSPA Networks This chapter describes all the calculations performed in Atoll UMTS HSPA documents. All the calculations are performed on TBC (to be calculated) transmitters. For the definition of TBC transmitters please refer to "Path Loss Matrices" on page 103.
4.1 General Prediction Studies 4.1.1 Calculation Criteria Three criteria can be studied in point analysis (Profile tab) and in common coverage studies. Study criteria are detailed in the table below: Study criteria
Formulas
Signal level ( P rec ) in dBm
Signal level received from a transmitter on a carrier (cell) P rec ic = EIRP ic – L path – M Shadowing – model – L Indoor + G term – L term L path = L model + L ant
Path loss ( L path ) in dBm Total losses ( L total ) in dBm
Tx
L total = L path + L Tx + L term + L indoor + M Shadowing – model – G Tx + G term
where, EIRP is the effective isotropic radiated power of the transmitter, ic is a carrier rank, L model is the loss on the transmitter-receiver path (path loss) calculated by the propagation model, L ant
Tx
is the transmitter antenna attenuation (from antenna patterns),
M Shadowing – model is the shadowing margin. This parameter is taken into account when the option “Shadowing taken into account” is selected, L Indoor are the indoor losses, taken into account when the option “Indoor coverage” is selected, L term are the receiver losses, G term is the receiver antenna gain, G Tx is the transmitter antenna gain, L Tx is the transmitter loss ( L Tx = L total – DL ). For information on calculating transmitter loss, see "UMTS, CDMA2000, TDSCDMA, WiMAX, and LTE Documents" on page 30. •
EIRP ic = P pilot ic + G Tx – L Tx ( P pilot ic is the cell pilot power).
•
When you make the prediction, you can consider the best carrier of all bands or the best carrier of a particular frequency band (Best (All Bands/Specific Band) option). In this case, Atoll takes the highest pilot power of carriers to calculate the signal level received from a transmitter. Atoll considers that G term and L term equal zero.
•
4.1.2 Point Analysis 4.1.2.1 Profile Tab Atoll displays either the signal level received from the selected transmitter on a carrier ( P rec ic ), or the highest signal level received from the selected transmitter on the best carrier.
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For a selected transmitter, it is also possible to study the path loss, L path , or the total losses, L total . Path loss and total losses are the same on any carrier.
4.1.2.2 Reception Tab Analysis provided in the Reception tab is based on path loss matrices. So, you can study reception from TBC transmitters for which path loss matrices have been computed on their calculation areas. For each transmitter, Atoll displays either the signal level received on a carrier, ( P rec ic ), or the highest signal level received on the best carrier. Reception bars are displayed in a decreasing signal level order. The maximum number of reception bars depends on the signal level received from the best serving cell. Only reception bars of cells whose signal level is within a 30 dB margin from the best serving cell can be displayed. •
For a selected transmitter, it is also possible to study the path loss, L path , or the total losses, L total . Path loss and total losses are the same on any carrier.
•
You can use a value other than 30 dB for the margin from the best serving cell signal level, for example a smaller value for improving the calculation speed. For more information on defining a different value for this margin, see the Administrator Manual.
4.1.3 Coverage Studies For each TBC transmitter, Txi, Atoll determines the selected criterion on each pixel inside the Txi calculation area. In fact, each pixel within the Txi calculation area is considered as a potential (fixed or mobile) receiver. Coverage study parameters to be set are: • •
The study conditions in order to determine the service area of each TBC transmitter, The display settings to select how to colour service areas.
4.1.3.1 Service Area Determination Atoll uses parameters entered in the Condition tab of the coverage study property dialogue to predetermine areas where it will display coverage. We can distinguish three cases:
4.1.3.1.1
All Servers The service area of Txi corresponds to the bins where: Txi
Txi
Txi
MinimumThreshold P rec ic or L total or L path MaximumThreshold
4.1.3.1.2
Best Signal Level and a Margin The service area of Txi corresponds to the bins where: Txi
Txi
Txi
MinimumThreshold P rec ic or L total or L path MaximumThreshold And Txi Txj P rec ic Best P rec ic – M ji
M is the specified margin (dB). Best function: considers the highest value.
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•
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is the highest. If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi is either the highest or 2dB lower than the highest. If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi is 2dB higher than the signal levels from transmitters, which are 2nd best servers.
• •
4.1.3.1.3
Second Best Signal Level and a Margin The service area of Txi corresponds to the bins where: Txi
Txi
Txi
MinimumThreshold P rec ic or L total or L path MaximumThreshold And nd
Txi Txj P rec ic 2 Best P rec ic – M ji
M is the specified margin (dB). 2nd Best function: considers the second highest value. • • •
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is the second highest. If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi is either the second highest or 2dB lower than the second highest. If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi is 2dB higher than the signal levels from transmitters, which are 3rd best servers.
4.1.3.2 Coverage Display 4.1.3.2.1
Plot Resolution Prediction plot resolution is independent of the matrix resolutions and can be defined on a per study basis. Prediction plots are generated from multi-resolution path loss matrices using bilinear interpolation method (similar to the one used to evaluate site altitude).
4.1.3.2.2
Display Types It is possible to display the transmitter service area with colours depending on any transmitter attribute or other criteria such as: Signal Level (in dBm, dBµV, dBµV/m) Atoll calculates signal level received from the transmitter on each pixel of each transmitter service area. A pixel of a service area is coloured if the signal level is greater than or equal to the defined minimum thresholds (pixel colour depends on signal level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as transmitter service areas. Each layer shows the different signal levels available in the transmitter service area. Best Signal Level (in dBm, dBµV, dBµV/m) Atoll calculates signal levels received from transmitters on each pixel of each transmitter service area. Where other service areas overlap the studied one, Atoll chooses the highest value. A pixel of a service area is coloured if the signal level is greater than or equal to the defined thresholds (the pixel colour depends on the signal level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the signal level from the best server exceeds a defined minimum threshold. Path Loss (dB) Atoll calculates path loss from the transmitter on each pixel of each transmitter service area. A pixel of a service area is coloured if path loss is greater than or equal to the defined minimum thresholds (pixel colour depends on path loss). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as service areas. Each layer shows the different path loss levels in the transmitter service area.
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Total Losses (dB) Atoll calculates total losses from the transmitter on each pixel of each transmitter service area. A pixel of a service area is coloured if total losses is greater than or equal to the defined minimum thresholds (pixel colour depends on total losses). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as service areas. Each layer shows the different total losses levels in the transmitter service area. Best Server Path Loss (dB) Atoll calculates signal levels received from transmitters on each pixel of each transmitter service area. Where other service areas overlap the studied one, Atoll determines the best transmitter and evaluates path loss from the best transmitter. A pixel of a service area is coloured if the path loss is greater than or equal to the defined thresholds (pixel colour depends on path loss). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the path loss from the best server exceeds a defined minimum threshold. Best Server Total Losses (dB) Atoll calculates signal levels received from transmitters on each pixel of each transmitter service area. Where service areas overlap the studied one, Atoll determines the best transmitter and evaluates total losses from the best transmitter. A pixel of a service area is coloured if the total losses is greater than or equal to the defined thresholds (pixel colour depends on total losses). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the total losses from the best server exceed a defined minimum threshold. Number of Servers Atoll evaluates how many service areas cover a pixel in order to determine the number of servers. The pixel colour depends on the number of servers. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the number of servers is greater than or equal to a defined minimum threshold. Cell Edge Coverage Probability (%) On each pixel of each transmitter service area, the coverage corresponds to the pixels where the signal level from this transmitter fulfils signal conditions defined in Conditions tab with different Cell edge coverage probabilities. There is one coverage area per transmitter in the explorer. Best Cell Edge Coverage Probability (%) On each pixel of each transmitter service area, the coverage corresponds to the pixels where the best signal level received fulfils signal conditions defined in Conditions tab. There is one coverage area per cell edge coverage probability in the explorer.
4.2 Definitions This section details the terms that describe the users and the services, the input parameters as well as the formulas used in simulations and predictions (coverage predictions and point analysis).
4.2.1 Glossary In this chapter, we will use the following terms to describe the users and the services: R99 users: The Circuit (R99) and Packet (R99) service users. They require an R99 bearer. HSDPA users: The users that only support HSDPA. They have an HSDPA-capable terminal and one of these services: • •
Packet (HSDPA - Best Effort), Packet (HSDPA - Variable Bit Rate).
HSDPA users require an R99 bearer (i.e. the A-DPCH radio bearer) and an HSDPA bearer. HSPA users: The users that support both HSDPA and HSUPA. They have an HSPA-capable terminal and one of these services: • • •
Packet (HSPA - Best Effort), Packet (HSPA - Variable Bit Rate), Packet (HSPA - Constant Bit Rate).
HSPA users require an R99 bearer (i.e. the E-DPCCH/A-DPCH radio bearer), an HSDPA bearer and an HSUPA bearer. DC-HSDPA users: The dual-cell HSDPA users. Users with dual-cell HSDPA-capable terminals that can simultaneously connect to two HSDPA cells of the transmitter for data transfer. The R99 A-DPCH bearer is transmitted on one of the cells, which is
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called the anchor cell. The user can be assigned an HSDPA bearer in each of the cells. MC-HSDPA users: The multi-cell HSDPA users. Users with multi-cell HSDPA-capable terminals that can simultaneously connect to several HSDPA cells of the transmitter for data transfer. The R99 A-DPCH bearer is transmitted on one of the cells, which is called the anchor cell. The user can be assigned an HSDPA bearer in each of the cells. DB-MC-HSDPA users: The dual-band multi-cell HSDPA users. Users with dual-band multi-cell HSDPA-capable terminals that can simultaneously connect to several HSDPA cells on co-site transmitters using different frequency bands. The R99 A-DPCH bearer is transmitted on one of the cells, which is called the anchor cell. The user can be assigned an HSDPA bearer in each of the cells. BE services: Best Effort services. VBR services: Variable Bit Rate services. CBR services: Constant Bit Rate services. CBR services do not support multi-cell HSDPA mode.
4.2.2 Inputs This table lists simulation and prediction inputs (calculation options, quality targets, active set management conditions, etc.). Name
Value
Unit
Description
F ortho
Clutter parameter
None
Orthogonality factor
Tx
Site equipment parameter
None
MUD factor
F MUD
Terminal parameter - HSDPA properties
None
MUD factor
cn first
Frequency band parameter
None
First carrier number
cnlast
Frequency band parameter
None
Last carrier number
cn
Frequency band parameter
None
Carrier number step
F MUD Term
ic
Frequency band parameter
None
Carrier rank of the current carrier calculated as follows: cn – cn first - – cn lower ic = ------------------------ cn Where cn lower is the number of carrier numbers lower than cn including excluded carriers and carriers of other frequency bands
Cell parameter
Threshold for macro diversity None specified for a transmitter on a given carrier ic
Cell parameter
Handover margin for a transmitter on a given carrier ic. None Used for best serving cell selection in UMTS and HSPA specific predictions.
CIO Txi ic
Cell parameter
Cell Individual Offset for a transmitter on a given carrier ic. None Used for best serving cell selection in UMTS and HSPA specific predictions.
RSCP min Txi ic
Cell parameter or Global parameter
W
The minimum pilot RSCP required for a user to be connected to the transmitter on a given carrier
E----c I 0 threshold Mobility parameter
None
Ec/I0 target on downlink for the best serving cell
Global parameter
None
Pilot RSCP threshold for compressed mode activation
Global parameter
None
Ec/I0 threshold for compressed mode activation
AS_Th Txi ic
M HO Txi ic
req
Q pilot CM – activation
RSCP pilot
CM – activation
Q pilot
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Name
Value
Unit
Description
E b ---(Reception equipment, R99 bearer, Mobility) parameter N t req
None
Eb/Nt target on downlink
Global parameter
None
Downlink Eb/Nt target increase due to compressed mode activation
E b --- N t req (Reception equipment, R99 bearer, Mobility) parameter
None
Eb/Nt target on uplink
Global parameter
None
Uplink Eb/Nt target increase due to compressed mode activation
Max
Site parameter
None
Number of channel elements available for a site on uplink
N CE – DL N I
Max
Site parameter
None
Number of channel elements available for a site on downlink
N CE – UL N I
Simulation result
None
Number of channel elements of a site consumed by users on uplink
N CE – DL N I
Simulation result
None
Number of channel elements of a site consumed by users on downlink
Site equipment parameter - UL overhead resources for common channels/cell
None
Number of channel elements used by the cell for common channels on uplink
Site equipment parameter - DL overhead resources for common channels/cell
None
Number of channel elements used by the cell for common channels on downlink
R99 – T CH
(R99 bearer, site equipment) parameter
None
Number of channel elements used for R99 traffic channels on uplink
R99 – T CH
(R99 bearer, site equipment) parameter
None
Number of channel elements used for R99 traffic channels on downlink
N CE
HSUPA
(HSUPA bearer, site equipment) parameter
None
Number of channel elements consumed by the HSUPA bearer on uplink
Max
Site parameter
kbps
Maximum Iub backhaul throughput for a site in the uplink
TP Iub – DL N I
Max
Site parameter
kbps
Maximum Iub backhaul throughput for a site in the downlink
TP Iub – UL N I
Simulation result
kbps
Iub backhaul throughput for a site in the uplink
TP Iub – DL N I
Simulation result
kbps
Iub backhaul throughput for a site in the downlink
Site equipment parameter
kbps
Iub throughput required by the cell for common channels in the downlink
HSDPA
Site equipment parameter
%
HSDPA Iub backhaul overhead
E1 T1 Ethernet
Site equipment parameter
kbps
Throughput carried by an E1/T1/ Ethernet link
R99 – T CH
(R99 bearer, site equipment) parameter
kbps
Iub backhaul throughput consumed by the R99 bearer in the uplink
R99 – T CH
(R99 bearer, site equipment) parameter
kbps
Iub backhaul throughput consumed by the R99 bearer in the downlink
HSUPA
(HSUPA bearer, site equipment) parameter
kbps
Iub backhaul throughput consumed by the HSUPA bearer in the uplink
N Codes Txi ic
Simulation constraint
None
Maximum number of 512 bit-length OVSF codes available per cell (512)
N Codes Txi ic
Simulation result
None
Number of 512 bit-length OVSF codes used by the cell
DL
DL
Q req DL
Q req UL
UL
Q req UL
Q req N CE – UL N I
Overhead
N CE – UL
Overhead
N CE – DL
N CE – UL N CE – DL
TP Iub – UL N I
Overhead
TP Iub – DL N I Overhead Iub TP
TPIub – UL TPIub – DL TP Iub Max
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AT330_TRR_E1
Name Overhead
N Codes
HSPDSCH – Min
N Codes
Unit
Description
Site equipment parameter - DL overhead resources for common channels/cell
None
Number of 256 bit-length OVSF codes used by the cell for common channels
Txi ic
Cell parameter (for HSDPA only)
Maximum number of 16 bit-length None OVSF codes available per cell for HSPDSCH
Txi ic
Cell parameter (for HSDPA only)
Minimum number of 16 bit-length None OVSF codes available per cell for HSPDSCH
HSPDSCH – Max
N Codes
Value
NF term
Terminal parameter
None
Terminal Noise Figure
NF Tx
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
None
Transmitter Noise Figure
K
1.38 10-23
J/K
Boltzman constant
T
293
K
Ambient temperature
W
3.84 MHz
Hz
Spreading Bandwidth
NRinter – techno log y
Cell parameter
Tx DL
NRinter – techno log y
Cell parameter Only used in uplink interference-based calculations of the MonteCarlo simulation
RF ic ic adj
Network parameter If not defined, it is assumed that there is no inter-carrier interference
Tx UL
Tx m
ICP ic ic i
Network parameter If not defined, it is assumed that there is no inter-technology downlink interferences due to external transmitters
None Inter-technology downlink noise rise None
Inter-technology uplink noise rise
None
Interference reduction factor between two adjacent carriers ic and ic adj
Inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the None frequency gap between ic i (external network) and ic
UL
Cell parameter (user-defined or simulation result)
%
Total uplink load factor of the cell
UL
Simulation result
%
Uplink cell load contribution due to R99 traffic
X HSUPA
Cell parameter
%
Uplink cell load contribution due to HSUPA traffic
UL
Simulation constraint (global parameter or cell parameter)
%
Maximum uplink load factor of the cell
Simulation constraint (global parameter or cell parameter)
%
Maximum percentage of used power
W
Thermal noise at transmitter
W
Thermal noise at terminal
bps
Chip rate
X
X R99 UL
X max DL
%Power max
Tx UL
Tx
NF Tx K T W NR inter – techno log y
Term
NF Term K T W NR inter – techno log y
N0 N0
Rc
Tx DL
W 10
–3
W
UL
Site equipment parameter
f rake efficiency
DL
Terminal parameter
None
Downlink rake receiver efficiency factor
TP P – DL
R99
R99 bearer parameter
kbps
R99 bearer downlink peak throughput
F spreading Active user
R99 bearer parameter
None
Downlink spreading factor for active users
DL
R99 bearer parameter
None
Downlink spreading factor for inactive users
f rake efficiency
DL
F spreading Inactive user
None Uplink rake receiver efficiency factor
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Name
Value
Unit
Description
rc
DL
R99 bearer parameter
None
Ratio between DPCCH and DPCH transmission duration on downlink DPCCH and DPCH respectively refer to the Dedicated Physical Control Channel and Dedicated Physical Channel
TP max – DL
Cell parameter
kbps
Maximum connection throughput per user on downlink
TP P – UL
R99
R99 bearer parameter
kbps
R99 bearer uplink peak throughput
f act
UL
Service parameter
kbps
Uplink activity factor for the service
f act
DL
Service parameter
kbps
Downlink activity factor for the service
f act –ADPCH
UL
Service parameter
kbps
Uplink activity factor on E-DPCCH channels
f act –ADPCH
DL
Service parameter
kbps
Downlink Activity factor on A-DPCH channel
TPD min – UL
Service parameter
kbps
Minimum required bit rate that the service should have in order to be available in the uplink
TPD min – DL
Service parameter
kbps
Minimum required bit rate that the service should have in order to be available in the downlink
TPD max – UL
Service parameter
kbps
Maximum bit rate that the service can require in the uplink
TPD max – DL
Service parameter
kbps
Maximum bit rate that the service can require in the downlink
Ratio between the DPCCH and DPCH powers transmitted on uplink DPCCH and DPCH respectively refer None to the Dedicated Physical Control Channel and Dedicated Physical Channel
rc
UL
R99 bearer parameter
TP max – UL
Cell parameter
kbps
Maximum connection throughput per user on uplink
W ----------------R99 TP P – DL
None
Service downlink processing gain
Gp
W ----------------R99 TP P – UL
None
Service uplink processing gain
I HSDPABearer
HSDPA bearer parameter
None
Index of the HSDPA bearer obtained by the user in the cell (Txi,ic)
HSDPA bearer parameter
kbps
Peak RLC throughput supported by the HSDPA bearer
kbps
Peak RLC throughput provided to the user in the cell (Txi,ic) in the downlink
DL
Gp
UL
DL
TP P – RLC I HSDPABearer
DL
Without MIMO: TP P – RLC I HSDPABearer DL
TPP – RLC Tx ic
DL
With MIMO (transmit diversity): TP P – RLC I HSDPABearer With MIMO (spatial multiplexing): DL TP P – RLC I HSDPABearer
218
Max
1 + f SM – Gain G SM – 1
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AT330_TRR_E1
Name
Value
Unit
Description
kbps
Peak RLC throughput provided to the user in the downlink
TPD min – DL ----------------------------------------------------DL TP P – RLC I HSDPABearer
%
HSDPA bearer consumption for a CBR service user
HSDPA study result
kbps
Effective RLC throughput supported by the HSDPA bearer
HSDPA study result
kbps
Average effective RLC throughput supported by the HSDPA bearer
DL
HSDPA study result
kbps
Peak MAC throughput supported by the HSDPA bearer
DL
HSDPA study result
kbps
Effective MAC throughput supported by the HSDPA bearer
DL
HSDPA study result
kbps
User application throughput on downlink
TP A
UL
HSUPA study result
kbps
User application throughput on uplink
TP Av – A
UL
HSUPA study result
kbps
User average application throughput on uplink
I HSUPABearer
HSUPA Bearer parameter
None
Index of the HSUPA bearer obtained in the cell (Txi,ic)
HSDPA study result For single-carrier HSDPA users DL
TP P – RLC Tx ic DL
TP P – RLC
For DC-HSDPA users
DL
TP P – RLC Tx ic
ic Tx
C HSDPABearer DL
TP E – RLC DL
TP Av – E – RLC TP P – MAC TP E – MAC TP A
N Rtx I HSUPABearer
HSUPA bearer selection parameter
Maximum number of retransmissions a HARQ process will kbps perform for a block of data before moving on to a new block of data, for the HSUPA bearer index
UL
TP P – RLC I HSUPABearer UL
HSUPA bearer parameter
kbps
Peak RLC throughput supported by the HSUPA bearer
kbps
Peak RLC throughput provided to the user in the cell (Txi,ic) in the uplink
HSUPA study result
TP P – RLC
TP P – RLC I HSUPABearer
C HSUPABearer
TPD min – UL ----------------------------------------------------UL TP P – RLC I HSUPABearer
%
HSUPA bearer consumption for a CBR service user
HSUPA study result
kbps
Minimum effective RLC throughput supported by the HSUPA bearer
TP Av – E – R LC
HSUPA study result
kbps
Average effective RLC throughput supported by the HSUPA bearer
TP P – M AC
UL
HSUPA study result
kbps
Peak MAC throughput supported by the HSUPA bearer
TP Offset
Service parameter (for HSDPA only)
kbps
Throughput offset
f TP – Scaling
Service parameter (for HSDPA only)
%
Scaling factor
P max Txi
Transmitter parameter
W
Maximum shared power Available only if the inter-carrier power sharing option is activated
P SCH Txi ic
Cell parameter
W
Cell synchronisation channel power
UL
TP Min –E – R LC UL
UL
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Name
Value
Unit
Description
P OtherCCH Txi ic
Cell parameter
W
Cell other common channels (except CPICH and SCH) power
P pilot Txi ic
Cell parameter
W
Cell pilot power
P HSDPA Txi ic
Cell parameter (user-defined or simulation result) (for HSDPA only) P HS – PDSCH Txi ic + n HS – SCCH P HS – SCCH Txi ic
W
Available cell HSDPA power HSDPA: High Speed Downlink Packet Access
P HS – PDSCH Txi ic
Simulation result (for HSDPA only)
W
Cell HS-PDSCH power HS-PDSCH: High Speed Physical Downlink Shared Channel
P HS – SCCH Txi ic
Cell parameter (for HSDPA only)
W
Cell HS-SCCH power HS-SCCH: High Speed Shared Control Channel
n HS – SCCH
Cell parameter (for HSDPA only)
P Headroom Txi ic
Cell parameter (for HSDPA only)
W
Cell headroom power
P max Txi ic
Cell parameter
W
Maximum Cell power
P tch Txi ic
Simulation result
W
R99 traffic channel power transmitted on carrier ic
min
R99 bearer parameter
W
Minimum power allowed on R99 traffic data channel
P tch
max
R99 bearer parameter
W
Maximum power allowed on R99 traffic data channel
P HSUPA Txi ic
Cell parameter
W
Cell HSUPA power HSUPA: High Speed Uplink Packet Access
P tx –H SDPA Txi ic
Simulation result
W
Transmitter HSDPA power transmitted on carrier ic
W
Transmitter R99 power transmitted on carrier ic
P tch
number of HS-SCCH channels managed by the cell
Simulation result P pilot Txi ic + P SCH Txi ic + P OtherCCH Txi ic + P tx – R99 Txi ic
P tch Txi ic +
tch(ic) used for R99 users
DL
P tch Txi ic f act –ADPCH
tch(ic) used for HSUPA users
P tx Txi ic
Cell parameter (user-defined or simulation result) P tx – R99 Txi ic + P tx – H SDPA Txi ic + P HSUPA Txi ic
W
Transmitter total power transmitted on carrier ic
P term – R99
Calculated in the simulation but not displayed
W
Terminal power transmitted to obtain the R99 radio bearer
P term – HSUPA
Calculated in the simulation but not displayed
W
Terminal power transmitted to obtain the HSUPA radio bearer
W
Total power transmitted by the terminal
Simulation result P term
P term – R99
UL f act – ADPCH
+ P term – HSUPA for HSPA users
P term – R99 for R99 and HSDPA users
220
P term
min
Terminal parameter
W
Minimum terminal power allowed
P term
max
Terminal parameter
W
Maximum terminal power allowed
BTS
BTS parameter
%
Percentage of BTS signal correctly transmitted
term
Terminal parameter
%
Percentage of terminal signal correctly transmitted
Clutter parameter
%
Percentage of pilot finger percentage of signal received by the terminal pilot finger
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AT330_TRR_E1
Name
Value
Unit
Description
G Tx
Antenna parameter
None
Transmitter antenna gain
G Term
Terminal parameter
None
Terminal gain
DL
R99 bearer parameter - Depends on the transmitter Tx diversity
None
Gain due to transmit diversity
UL
R99 bearer parameter - Depends on the transmitter Rx diversity
None
Gain due to receive diversity
G SM
Max
MIMO configuration parameter
dB
Maximum spatial multiplexing gain for a given number of transmission and reception antennas
G TD
DL
MIMO configuration parameter
dB
Downlink Transmit Diversity gain for a given number of transmission and reception antenna ports
f SM – Gain
Clutter parameter
None
Spatial multiplexing gain factor
G TD
Clutter parameter
dB
Additional diversity gain in downlink
L Tx
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
None
Transmitter lossa
L body
Service parameter
None
Body loss
L Term
Terminal parameter
None
Terminal loss
L indoor
Clutter parameter
L path
Propagation model result
None
Path loss
M Shadowing – model
Result calculated from cell edge coverage probability and model standard deviation
None
Model Shadowing margin Only used in prediction studies
M Shadowing – Ec Io
Result calculated from cell edge coverage probability and Ec/I0 standard deviation
None
Ec/I0 Shadowing margin Only used in prediction studies
None
DL gain due to availability of several pilot signals at the mobile b.
DL
Result calculated from cell edge coverage probability and DL Eb/Nt standard deviation
None
DL Eb/Nt Shadowing margin Only used in prediction studies
UL
Result calculated from cell edge coverage probability and UL Eb/Nt standard deviation
None
UL Eb/Nt Shadowing margin Only used in prediction studies
None
UL quality gain due to signal diversity in soft handoffc.
None
Random shadowing error drawn during Monte-Carlo simulation Only used in simulations
G Div G Div
DL
DL
M Shadowing – Eb Nt
n=2 or 3
UL
UL
G macro – diversity
E Shadowing
npaths
G macro – diversity = M Shadowing – Ec Io – M Shadowing – Ec Io
DL
G macro – diversity M Shadowing – Eb Nt
Indoor loss
npaths
G macro – diversity = M Shadowing – Eb Nt
UL
– M Shadowing – Eb Nt
n=2 or 3 Global parameter (default value) Simulation result
UL
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Name
Value
Unit
Description
None
Transmitter-terminal total loss
P pilot Txi ic -------------------------------LT
W
Chip power received at terminal
DL
P tch Txi ic ----------------------------LT
W
Bit power received at terminal on carrier ic
DL
P tx Txi ic --------------------------LT
W
Total power received at terminal from a transmitter on carrier ic
P tch Txi ic ----------------------------LT
W
Total power received at terminal from traffic channels of a transmitter on carrier ic
P term -----------LT
W
Bit power received at transmitter on carrier ic used by terminal
P term – R99 -----------------------LT
W
Bit power received at transmitter on carrier ic used by terminal
W
Bit power received at transmitter on DPDCH from a terminal on carrier ic
In prediction studiesd For Ec/I0 calculation L path L Tx L term L body L indoor M Shadowing – Ec Io ------------------------------------------------------------------------------------------------------------------------------------G Tx G term For DL Eb/Nt calculation L path L Tx L term L body L indoor M Shadowing – Eb Nt DL ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term
LT
For UL Eb/Nt calculation L path L Tx L term L body L indoor M Shadowing – Eb Nt UL ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term In simulations L path L Tx L term L body L indoor E Shadowing ------------------------------------------------------------------------------------------------------------------G Tx G term P c Txi ic P b Txi ic P tot Txi ic
DL
P traf Txi ic
tch ic
UL
P b ic UL
P b – R99 ic UL
UL
P b – DPDCH ic a.
UL
P b – R99 ic 1 – r c
L Tx = L total – UL on uplink and L Tx = L total – DL on downlink. For information on calculating transmitter losses on uplink and downlink, see "UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE Documents" on page 30.
b.
npaths
M Shadowing –Ec Io corresponds to the shadowing margin evaluated from the shadowing error probability density function (n paths) in case of downlink Ec/I0 modelling. npaths
c.
M Shadowing – Eb Nt
d.
case of uplink soft handoff modelling. In uplink prediction studies, only carrier power level is downgraded by the shadowing margin ( M Shadowing – Eb Nt
UL
corresponds to the shadowing margin evaluated from the shadowing error probability density function (n paths) in
UL
). In downlink
prediction studies, carrier power level and intra-cell interference are downgraded by the shadowing model ( M Shadowing – Eb Nt M Shadowing – Ec Io ) while extra-cell interference level is not. Therefore, M Shadowing – Eb Nt
DL
DL
or M Shadowing – Ec Io is set to 1 in downlink
extra-cell interference calculation.
4.2.3 Ec/I0 Calculation This table details the pilot quality ( Q pilot or Ec Io ) calculations. Name
Value
I intra txi ic
P SCH txi ic DL DL P tot txi ic – BTS P tot txi ic – ---------------------------- L
DL
222
T
or
Unit
Description
W
Downlink intra-cell interference at terminal on carrier ic
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 4: UMTS HSPA Networks
AT330_TRR_E1
Name
Value
DL
I extra ic
DL
P tot txj ic
Unit
Description
W
Downlink extra-cell interference at terminal on carrier ic
W
Downlink inter-carrier interference at terminal on carrier ic
txj j i
Ptot txj icadj DL
DL
I inter – carrier ic
txj j ---------------------------------------------
RF ic ic adj
DL I inter – techno log y ic
ni
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic
W
Downlink inter-technology interference at terminal on carrier ic a
i
Without Pilot: DL
DL
DL
DL
I intra txi ic + I extra ic + I inter – carrier ic + I inter – techno log y ic Term
+ N0
DL
I 0 ic
– 1 – BTS P c txi ic
DL
Total noise:
DL
W
Total received noise at terminal on carrier ic
None
Quality level at terminal on pilot for carrier ic
DL
P tot txi ic + I extra ic + I inter – carrier ic DL
Term
+ I inter – techno log y ic + N 0 BTS P c txi ic -------------------------------------------------DL I 0 ic
E Q pilot txi ic ----c I0 a.
In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the fractional load.
4.2.4 DL Eb/Nt Calculation Eb DL This table details calculations of downlink traffic channel quality ( Q tch or ------ ). Nt DL Name
Value
Unit
Description
I intra txi ic
P SCH txi ic DL DL - P tot txi ic – BTS F ortho P tot txi ic – ----------------------------L
W
Downlink intra-cell interference at terminal on carrier ic
W
Downlink extra-cell interference at terminal on carrier ic
W
Downlink inter-carrier interference at terminal on carrier ic
DL
T
DL
I extra ic
DL
P tot txj ic
txj j i
Ptot txj icadj DL
DL I inter – carrier ic
txj j --------------------------------------------RF ic ic adj Tx
P Transmitted ic i
------------------------------------Tx Tx m L ICP
DL
I inter – techno log y ic DL
N tot ic
DL
DL
ic i ic
total
ni
W
DL
DL
Downlink inter-technology interference at terminal on carrier ic a
Term
I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0
W
Total received noise at terminal on carrier ic
None
Quality level at terminal on a traffic channel from one transmitter on carrier ic b
Without useful signal: DL
E DL Q tch txi ic ----b- N t DL
BTS P b txi ic DL ------------------------------------------------------------------------------------------------------ G DL Div G p DL DL N tot ic – 1 – F ortho BTS P b txi ic DL
BTS P b txi ic DL - G DL Total Noise: ------------------------------------------Div G p DL N tot ic
DL
Q ic
DL
f rake efficiency
tx k ActiveSet
DL
Q tch tx k ic
Quality level at terminal using carrier ic due to combination of all None transmitters of the active set (Macro-diversity conditions).
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Name
Value
Unit
Description
None
Soft handover gain on downlink
W
Required transmitter traffic channel power to achieve Eb/Nt target at terminal on carrier ic
DL
G SHO
Q ic --------------------------------------------------DL Q tch BestServer ic
req P tch txi
Q req ----------------- P tch txi ic DL Q ic
DL
DL
a. b.
ic
In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the fractional load. Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt.
4.2.5 UL Eb/Nt Calculation Eb UL This table details calculations of uplink traffic channel quality ( Q tch or ------ ). Nt UL Name
Value
Pb
UL
UL intra
I tot
UL extra
I tot
txi ic
ic
term txi
txi ic
Unit
Description
W
Total power received at transmitter from intra-cell terminals using carrier ic
W
Total power received at transmitter from extra-cell terminals using carrier ic
W
Uplink inter-carrier interference at terminal on carrier ic
UL
P b ic
term txj j i
Pb
UL
UL
I inter – carrier txi ic
UL
I tot txi ic
UL N tot txi
ic
ic adj
term txj j ----------------------------------RF ic ic adj UL extra
I tot
UL intra
Tx
txi ic + 1 – F MUD term I tot UL I tot txi
ic +
UL txi ic + I inter – carrier txi W ic
tx N0
Total received interference at transmitter on carrier ic
W
Total noise at transmitter on carrier ic (Uplink interference)
None
Quality level at transmitter on a traffic channel for carrier ic a
Without useful signal: UL
E UL Q tch txi ic ----b- N t UL
224
term P b – DPDCH ic UL -------------------------------------------------------------------------------------------------------- G UL Div G p UL Tx UL N tot txi ic – 1 – F MUD term P b ic UL
term P b – DPDCH ic UL - G UL Total noise: --------------------------------------------------Div G p UL N tot txi ic
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 4: UMTS HSPA Networks
AT330_TRR_E1
Name
Value
Unit
Description
UL
No HO: Q tch txi ic
UL
Softer HO: f rake efficiency
UL
Q tch txk ic
tx k ActiveSet samesite
Soft, softer/soft HO (No MRC): Max Q UL tch tx k tx k ActiveSet
UL
ic G macro – diversity
UL
Q ic
Softer/soft HO (MRC):
Quality level at site using carrier ic due to combination of all transmitters of the active set located at the same site and taking into None account increasing of the quality due to macro-diversity (macro-diversity gain).
UL UL UL Q tch tx k ic Q tch tx l ic txk ,txl ActiveSet f rake efficiency tx k samesite tx k Max
UL
In simulations G macro – diversity = 1 .
tx othersite l
UL
G macro – diversity UL
Q ic --------------------------------------------------UL Q tch BestServer ic
UL
G SHO
None
Soft handover gain on uplink
W
Required terminal power to achieve Eb/Nt target at transmitter on carrier ic
UL
Q req ----------------- P term UL Q ic
req
P term ic a.
Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt.
4.3 Simulations The simulation process consists of two steps: 1. Obtaining a realistic user distribution Atoll generates a user distribution using a Monte-Carlo algorithm, which requires traffic maps and data as input. The resulting user distribution complies with the traffic database and maps provided to the algorithm. Each user is assigned a service, a mobility type, and an activity status by random trial, according to a probability law that uses the traffic database. The user activity status is an important output of the random trial and has direct consequences on the next step of the simulation and on the network interferences. A user may be either active or inactive. Both active and inactive users consume radio resources and create interference. Then, Atoll randomly assigns a shadowing error to each user using the probability distribution that describes the shadowing effect. Finally, another random trial determines user positions in their respective traffic zone and whether they are indoors or outdoors (according to the clutter weighting and the indoor ratio per clutter class defined for the traffic maps). 2. Power control simulation
4.3.1 Generating a Realistic User Distribution During the simulation, a first random trial is performed to determine the number of users and their activity status. Four activity status are modelled: •
Active UL: the user is active on UL and inactive on DL
•
Active DL: the user is active on DL and inactive on UL
•
Active UL+DL: the user is active on UL and on DL
•
Inactive: the user is inactive on UL and on DL
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The determination of the number of users and the activity status allocation depend on the type of traffic cartography used. Atoll determines the total number of users attempting connection in each simulation based on the Poisson distribution. This may lead to slight variations in the total numbers of users in different simulations. To have the same total number of users in each simulation of a group, add the following lines in the Atoll.ini file: [Simulation] RandomTotalUsers=0
4.3.1.1 Simulations Based on User Profile Traffic Maps User profile environment based traffic maps: Each pixel of the map is assigned an environment class which contains a list of user profiles with an associated mobility type and a given density (number of subscribers with the same profile per km²). User profile traffic maps: Each polygon and line of the map is assigned a density of subscribers with given user profile and mobility type. If the map is composed of points, each point is assigned a number of subscribers with given user profile and mobility type. The user profile models the behaviour of the different subscriber categories. Each user profile contains a list of services and their associated parameters describing how these services are accessed by the subscriber. From environment (or polygon) surface (S) and user profile density (D), a number of subscribers (X) per user profile is inferred. X = SD •
•
When user profile traffic maps are composed of lines, the number of subscribers (X) per user profile is calculated from the line length (L) and the user profile density (D) (nb of subscribers per km) as follows: X = L D The number of subscribers (X) is an input when a user profile traffic map is composed of points.
For each behaviour described in a user profile, according to the service, frequency use and exchange volume, Atoll calculates the probability for the user being active in uplink and in downlink at an instant t.
4.3.1.1.1
Circuit Switched Service (i) User profile parameters for circuit switched services are: • •
The used terminal (equipment used for the service (from the Terminals table)), The average number of calls per hour N call ,
•
The average duration of a call (seconds) d .
The number of users and their distribution per activity status is determined as follows: •
Calculation of the service usage duration per hour ( p 0 : probability of a connection):
N call d p o = ------------------3600 •
Calculation of the number of users trying to access the service i ( n i ):
ni = X p0 Next, we can take into account activity periods during the connection in order to determine the activity status of each user. •
Calculation of activity probabilities: UL
DL
Probability of being inactive on UL and DL: p inactive = 1 – f act 1 – f act UL
DL
DL
UL
Probability of being active on UL only: p UL = f act 1 – f act Probability of being active on DL only: p DL = f act 1 – f act UL
DL
Probability of being active both on UL and DL: p UL + DL = f act f act UL
DL
Where, f act and f act are respectively the UL and DL activity factors defined for the circuit switched service i. •
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Calculation of number of users per activity status:
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Number of inactive users on UL and DL: n i
= n i p inactive
Number of users active on UL and inactive on DL: n i UL = n i p UL Number of users active on DL and inactive on UL: n i DL = n i p DL Number of users active on UL and DL both: n i UL + DL = n i p UL + DL Therefore, a user when he is connected can have four different activity status: either active on both links, or inactive on both links, or active on UL only, or active on DL only.
4.3.1.1.2
Packet Switched Service (j) User profile parameters for packet switched services are: • •
The used terminal (equipment used for the service (from the Terminals table)), The average number of packet sessions per hour N sess ,
•
The volume (in kbytes) which is transferred on the downlink V DL and the uplink V UL during a session.
A packet session consists of several packet calls separated by a reading time. Each packet call is defined by its size and may be divided in packets of fixed size (1500 Bytes) separated by an inter arrival time. In Atoll, a packet session is described by following parameters: UL
N packet –c all : Average number of packet calls on the uplink during a session, DL
N packet –c all : Average number of packet calls on the downlink during a session, UL
T packet – call : Average time (millisecond) between two packets calls on the uplink , DL
T packet – call : Average time (millisecond) between two packets calls on the downlink , UL
T packet : Average time (millisecond) between two packets on the uplink , DL
T packet : Average time (millisecond) between two packets on the downlink , UL
S packet : Packet size (Bytes) on uplink, DL
S packet : Packet size (Bytes) on downlink.
Figure 4.1: Description of a Packet Session The number of users and their distribution per activity status is determined as follows: •
Calculation of the average packet call size (kBytes):
V UL V DL UL DL S packet –c all = ---------------------------------------and S packet –c all = ---------------------------------------UL UL DL DL N packet –c all f eff N packet –c all f eff UL
DL
Where f eff and f eff are the UL and DL efficiency factors defined for the packet switched service j.
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UL
DL
For packet (HSDPA) and packet (HSPA) services, f eff and f eff are set to 1.
•
Calculation of the average number of packets per packet call: UL
DL
S packet –c all S packet – c all UL - + 1 and N DL - + 1 N packet = int ------------------------------packet = int ------------------------------UL S packet 1024 S DL packet 1024 1kBytes = 1024Bytes.
•
Calculation of the average duration of inactivity within a packet call (s): UL
UL
DL
DL
N packet – 1 T packet N packet – 1 T packet UL DL D Inactivity packet – call = --------------------------------------------------------- and D Inactivity packet – call = --------------------------------------------------------1000 1000 •
Calculation of the average duration of inactivity in a session (s):
UL
UL
UL
DL
DL
DL
D Inactivity session = N packet –c all D Inactivity packet – call and D Inactivity session = N packet –c all D Inactivity packet – call •
Calculation of the average duration of activity in a session (s): UL
UL
DL
DL
N packet S packet 8 N packet S packet 8 UL UL DL - and D DL D Activity session = N packet –c all -----------------------------------------------Activity session = N packet – c all -----------------------------------------------UL DL TP Av 1000 TP Av 1000 UL
DL
Where TP Av and TPAv are the uplink and downlink average requested throughputs defined for the service j. Therefore, the average duration of a connection (in s) is: UL
UL
UL
DL
DL
DL
D Connection = D Activity session + D Inactivity session and D Connection = D Activity session + D Inactivity session •
Calculation of the service usage duration per hour (probability of a connection):
N sess N sess UL UL DL DL p Connection = ------------ D Connection and p Connection = ------------ D Connection 3600 3600 •
Calculation of the probability of being connected: UL
DL
p Connected = 1 – 1 – p Connection 1 – p Connection Therefore, the number of users who want to get the service j is: n j = X p Connected As you can see on the picture above, we have to consider three possible cases when a user is connected: •
1st case: At a given time, packets are downloaded and uploaded.
In this case, the probability of being connected is: UL
DL
p Connection p Connection UL + DL p Connected = --------------------------------------------------------p Connected •
2nd case: At a given time, packet are uploaded (no packet is downloaded).
Here, the probability of being connected is: UL
DL
p Connection 1 – p Connection UL p Connected = ----------------------------------------------------------------------p Connected •
3rd case: At a given time, packet are downloaded (no packet is uploaded).
In this case, the probability of being connected is: DL
UL
p Connection 1 – p Connection DL p Connected = ----------------------------------------------------------------------p Connected
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Now, we have to take into account activity periods during the connection in order to determine the activity status of each user. • f
UL
Calculation of the probability of being active: UL
DL
D Activity session D Activity session DL = -------------------------------------------------------------------------------------------and f = -------------------------------------------------------------------------------------------UL UL DL DL D Inactivity session + D Activity session D Inactivity session + D Activity session
Therefore, we have: •
1st case: At a given time, packets are downloaded and uploaded.
The user can be active on UL and inactive on DL; this probability is: 1
p UL = f
UL
DL
UL + DL
1 – f p Connected
The user can be active on DL and inactive on UL; this probability is: 1
p DL = f
DL
UL
UL + DL
1 – f p Connected
The user can be active on both links; this probability is: 1
p UL + DL = f
UL
f
DL
UL + DL
p Connected
The user can be inactive on both links; this probability is: UL
1
DL
UL + DL
p inactive = 1 – f 1 – f p Connected •
2nd case: At a given time, packet are uploaded (no packet is downloaded).
The user can be active on UL and inactive on DL; this probability is: 2
p UL = f
UL
UL
p Connected
The user can be inactive on both links; this probability is: UL
2
UL
p inactive = 1 – f p Connected •
3rd case: At a given time, packet are downloaded (no packet is uploaded).
The user can be active on DL and inactive on UL; this probability is: 3
p DL = f
DL
DL
p Connected
The user can be inactive on both links; this probability is: DL
3
DL
p inactive = 1 – f p Connected •
Calculation of number of users per activity status inactive
Number of inactive users on UL and DL: n j
1
2
3
= n j p inactive + p inactive + p inactive 1
2
1
3
Number of users active on UL and inactive on DL: n j UL = n j p UL + p UL Number of users active on DL and inactive on UL: n j DL = n j p DL + p DL 1
Number of users active on UL and DL: n j UL + DL = n j p UL + DL Therefore, a user when he is connected can have four different activity status: either active on both links, or inactive on both links, or active on UL only, or active on DL only. The user distribution per service and the activity status distribution between the users are average distributions. And the service and the activity status of each user are randomly drawn in each simulation. Therefore, if you compute several simulations at once, the average number of users per service and average numbers of inactive, active on UL, active on DL and active on UL and DL users, respectively, will correspond to calculated distributions. But if you check each simulation, the user distribution between services as well as the activity status distribution between users is different in each of them.
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4.3.1.2 Simulations Based on Sector Traffic Maps Sector traffic maps can be based on live traffic data from OMC (Operation and Maintenance Centre). Traffic is spread over the best server coverage area of each transmitter and each coverage area is assigned either the throughputs in the uplink and in the downlink or the number of users per activity status or the total number of users (including all activity statuses).
4.3.1.2.1
Throughputs in Uplink and Downlink When selecting Throughputs in Uplink and Downlink, you can input the throughput demands in the uplink and downlink for each sector and for each listed service. Atoll calculates the number of users active in uplink and in downlink in the Txi cell using the service (NUL and NDL) as follows: UL
Rt N UL = ---------- and UL TP Av
DL
Rt N DL = ---------DL TP Av
UL
is the kbits per second transmitted in UL in the Txi cell to supply the service.
DL
is the kbits per second transmitted in DL in the Txi cell to supply the service.
Rt Rt
DL
TP Av is the downlink average requested throughput defined for the service, UL
TP Av is the uplink average requested throughput defined for the service. NUL and NDL values include: • • •
Users active in uplink and inactive in downlink (ni(UL)), Users active in downlink and inactive in uplink (ni(DL)), And users active in both links (ni(UL+DL)).
Atoll takes into account activity periods during the connection in order to determine the activity status of each user. Activity probabilities are calculated as follows: UL
DL
Probability of being inactive in UL and DL: p inactive = 1 – f act 1 – f act UL
DL
DL
UL
Probability of being active in UL only: p UL = f act 1 – f act Probability of being active in DL only: p DL = f act 1 – f act UL
DL
Probability of being active both in UL and DL: p UL + DL = f act f act UL
DL
Where, f act and f act are respectively the UL and DL activity factors defined for the service i. Then, Atoll calculates the number of users per activity status: We have: p UL + p UL + DL n j UL + n j DL + n j UL + DL = N UL p DL + p UL + DL n j UL + n j DL + n j UL + DL = N DL Therefore, we have: N UL p UL + DL N DL p UL + DL Number of users active in UL and DL both: n i UL + DL = min --------------------------------- -------------------------------- p UL + p UL + DL p DL + p UL + DL Number of users active in UL and inactive in DL: n i UL = N UL – n i UL + DL Number of users active in DL and inactive in UL: n i DL = N DL – n i UL + DL inactive
Number of inactive users in UL and DL: n i
n j UL + n j DL + n j UL + DL - p inactive = -----------------------------------------------------------------------------1 – p inactive
Therefore, a connected user can have four different activity status: either active in both links, or inactive in both links, or active in UL only, or active in DL only.
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4.3.1.2.2
Total Number of Users (All Activity Statuses) When selecting Total Number of Users (All Activity Statuses), you can input the number of connected users for each sector and for each listed service ( n i ). Atoll takes into account activity periods during the connection in order to determine the activity status of each user. Activity probabilities are calculated as follows: UL
DL
Probability of being inactive in UL and DL: p inactive = 1 – f act 1 – f act UL
DL
DL
UL
Probability of being active in UL only: p UL = f act 1 – f act Probability of being active in DL only: p DL = f act 1 – f act UL
DL
Probability of being active both in UL and DL: p UL + DL = f act f act UL
DL
Where, f act and f act are respectively the UL and DL activity factors defined for the service i. Then, Atoll calculates the number of users per activity status: inactive
Number of inactive users in UL and DL: n i
= n i p inactive
Number of users active in UL and inactive in DL: n i UL = n i p UL Number of users active in DL and inactive in UL: n i DL = n i p DL Number of users active in UL and DL both: n i UL + DL = n i p UL + DL Therefore, a connected user can have four different activity status: either active in both links, or inactive in both links, or active in UL only, or active in DL only.
4.3.1.2.3
Number of Users per Activity Status inactive
When selecting Number of Users per Activity Status, you can directly input the number of inactive users ( n i
), the
number of users active in the uplink ( n i UL ), in the downlink ( n i DL ) and in the uplink and downlink ( n i UL + DL ), for each sector and for each service. The activity status distribution between users is an average distribution. In fact, in each simulation, the activity status of each user is randomly drawn. Therefore, if you compute several simulations at once, average numbers of inactive, active on UL, active on DL and active on UL and DL users correspond to the calculated distribution. But if you check each simulation, the activity status distribution between users is different in each of them.
4.3.2 Power Control Simulation The power control algorithm simulates the way a UMTS network regulates itself by using uplink and downlink power controls in order to minimize interference and maximize capacity. HSDPA users are linked to the A-DPCH radio bearer (an R99 radio bearer). Therefore, the network uses a A-DPCH power control on UL and DL and then it performs fast link adaptation on DL in order to select an HSDPA radio bearer. For HSPA users, the network first uses a E-DPCCH/A-DPCH power control on UL and DL, checks that there is an HSDPA connection on downlink and then carries out noise rise scheduling in order to select an HSUPA radio bearer on uplink. Atoll simulates these network regulation mechanisms with an iterative algorithm and calculates, for each user distribution, network parameters such as cell power, mobile terminal power, active set and handoff status for each terminal. During each iteration of the algorithm, all the users selected during the user distribution generation (1st step) attempt to connect one by one to network transmitters. The process is repeated until the network is balanced, i.e., until the convergence criteria (on UL and DL) are satisfied.
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Figure 4.2: UMTS HSPA Power Control Algorithm As shown in Figure 4.2 on page 232, the simulation algorithm is divided in three parts. All users are evaluated by the R99 part of the algorithm. HSDPA and HSPA users, unless they have been rejected during the R99 part of the algorithm, are then evaluated by the HSDPA part of the algorithm. Finally, HSPA users, unless they have been rejected during the R99 or HSDPA parts of the algorithm, are then evaluated by the HSUPA part of the algorithm. The steps of this algorithm are detailed below.
4.3.2.1 Algorithm Initialization The total power transmitted by the base station txi on the carrier ic m , P Tx txi ic m , is initialised to P pilot txi ic m + P SCH txi ic m + P otherCCH txi ic m + P HSDPA txi ic m + P HSUPA txi ic . UL intra
Uplink powers received by the base station txi on carrier ic m , I tot are initialised to 0 W (i.e. no connected mobile).
232
UL extra
txi ic m , I tot
UL
txi ic m and I inter – carrier txi ic m
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I tot txi ic m UL - = 0 Therefore, we have: X R99 txi ic m k = ------------------------------UL N tot txi ic m
4.3.2.2 R99 Part of the Algorithm The algorithm is detailed for any iteration k. Xk is the value of the X (variable) at the iteration k. In the algorithm, the UL
DL
thresholds, Q req and Q req , depend on the user mobility type and are defined in the R99 bearer selection table. All variables are described in Definitions and formulas part. The bearer downgrading is not dealt with. The algorithm applies to single frequency band networks and to multi-band networks. For each mobile (Mb), Atoll only considers the cells (txi,ic) for which the pilot RSCP exceeds the minimum pilot RSCP: P c txi M b ic RSCP min txi ic . For each mobile Mb, we have the following steps: Determination of Mb’s Best Serving Cell For each transmitter txi containing Mb in its calculation area and working on a frequency band supported by the Mb’s terminal ). BTS P c txi M b ic Calculation of Q pilot txi ic Mb = -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------Term k DL DL DL DL P tot txi ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0 If user selects “without Pilot” BTS P c txi M b ic Q pilot txi ic Mb = -----------------------------------------------------------------------------------------------------------------------------------------------------------k DL DL DL DL I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic Term + N0 – 1 – BTS P c txi M b ic Determination of the candidate cells, (txBS,ic). For each carrier ic, selection of the transmitter with the highest Q pilot txi M b ic , tx BS ic M i . k
Analysis of candidate cells, (txBS,ic). For each pair (txBS,ic), calculation of the uplink load factor: UL
I tot tx BS ic UL UL X R99 tx BS ic k = ------------------------------- + X UL N tot tx BS ic UL
X corresponds to the load rise due to the mobile. For information on how this parameter is calculated, see "Admission Control in the R99 Part" on page 276. Rejection of bad candidate cells if the pilot is not received or if the uplink load factor is exceeded during the admission load control (if simulation respects a loading factor constraint and Mb was not connected in previous iteration) pilot
If Q pilot tx BS M b ic Q req Mobility M b then (txBS,ic) is rejected by Mb k
UL
UL
If X R99 tx BS ic k X max , then (txBS,ic) is rejected by Mb Else Keep (txBS,ic) as good candidate cell If no good candidate cell has been selected, Mb has failed to be connected to the network and is rejected. For each NodeB having candidate cells, determination of the best carrier, icBS, within the set of candidate cells of the NodeB. For MC-HSDPA and DB-MC-HSDPA users, this carrier is referred to as the "anchor" carrier. If a given carrier is specified for the service requested by Mb ic BS M b is the carrier specified for the service Else the carrier selection mode defined for the site equipment is considered.
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If carrier selection mode is “Min. UL Load Factor” UL
ic BS M b is the carrier where we obtain the lowest X R99 tx BS ic k Else if carrier selection mode is “Min. DL Total Power” ic BS M b is the carrier where we obtain the lowest P tx tx BS ic k Else if carrier selection mode is “Random” ic BS M b is randomly selected Else if carrier selection mode is "Sequential" UL
UL
ic BS M b is the first carrier where X R99 tx BS ic k X max Endif Determination of the best serving cell, (txBS,icBS) max
(tx BS,ic BS) k M b is the best serving cell ( BestCell k M b ) and its pilot quality is Q pilot M b k
In the following lines, we will consider ic as the carrier used by the best serving cell Selection of the second serving cell for DC-HSDPA users MC-HSDPA and DB-MC-HSDPA users are processed as DC-HSDPA users. If txBS supports multi-cell HSDPA and if it has several carriers, selection of the second carrier, ic2, among the adjacent carriers. For each carrier adjacent to the best serving carrier, icp, calculation of Q pilot tx BS ic p M b k
Selection of the carrier, ic2, with the highest Q pilot tx BS ic p M b k
pilot
If Q pilot tx BS ic 2 M b Q req Mobility M b then (txBS,ic2) is rejected by Mb k
Else Keep (txBS,ic2) as second serving cell Active Set Determination For each station txi containing Mb in its calculation area, using ic , and, if neighbours are used, neighbour of BestCell k M b BTS P c txi M b ic Calculation of Q pilot txi M b ic = -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------DL DL DL DL Term k P tot txi ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0 If user selects “without Pilot” BTS P c txi M b ic Q pilot txi M b ic = ---------------------------------------------------------------------------------------------------------------------------------------------------------------------k DL DL DL DL I txi ic + I ic + I ic + I ic extra inter – carrier inter – techno log y intra Term + N0 – 1 – BTS P c txi M b ic Rejection of txi from the active set if difference with the best server is too high max
If Q pilot M b – Q pilot txi M b ic AS_Th BestCell k M b then txi is rejected k
k
Else txi is included in the Mb active set Rejection of a station if the mobile active set is full Station with the lowest Q pilot in the active set is rejected k
EndFor Uplink Power Control R99 – req
Calculation of the terminal power required by Mb to obtain the R99 radio bearer: P term For each cell (txi,ic) of the Mb active set
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Calculation of quality level on Mb traffic channel at (txi,ic), with the minimum power allowed on traffic channel for the Mb service req
P term – R99 M b ic k – 1 UL P b – R99 txi M b ic = ---------------------------------------------------L T txi M b UL
UL
UL
UL
UL
P b – DPDCH txi M b ic = P b – R99 txi M b ic 1 – r c UL
P b – DPCCH txi M b ic = P b – R99 txi M b ic r c UL
UL
UL
UL
UL
P b – R99 txi M b ic = P b – DPCCH txi M b ic + P b – DPDCH txi M b ic if the user is active, P b – R99 txi M b ic = P b – DPCCH txi M b ic if the user is inactive, UL
term P b – DPDCH txi M b ic k UL UL - G UL Q tch txi M b ic k = --------------------------------------------------------------------------------------------------------------------------------------------p Service M b G div UL Tx UL N tot txi ic – 1 – F MUD term P b – R99 txi M b ic k – 1 If user selects "Total noise", UL
term P b – DPDCH txi M b ic k UL UL UL Q tch txi M b ic k = ------------------------------------------------------------------------- G p Service Mb G div UL N tot txi ic End For If (Mb is in not in handoff) UL
UL
Q k M b = Q tch txi M b ic k Else if (Mi is in softer handoff) UL
UL
Q k M b = f rake efficiency
UL
Q tch txi M b ic k
txi ActiveSet
Else if (Mb is in soft, or softer/soft without MRC) UL
Qk Mb =
UL
UL
Max Q tch txi M b ic k G macro – diversity 2 links txi ActiveSet
Else if (Mb is in soft/soft) UL
Qk Mb =
UL
UL
Max Q tch txi M b ic k G macro – diversity 3 links txi ActiveSet
Else if (Mb is in softer/soft with MRC) UL Qk Mb
UL UL UL UL = Max f rake efficiency Q tch ic Q tch ic G macro – diversity 2 links other site txi ActiveSet samesite
End If UL
Q req Service M b Mobility M b req - P req P term – R99 M b ic k = ------------------------------------------------------------------------------------term – R99 M b ic k – 1 UL Qk Mb If compressed mode is operated, Compressed mode is operated if Mi and Sj support compressed mode, and Resulting
CM – activation
txi M b ic Q pilot
•
Either Q pilot
•
Or P c txi M b ic RSCP pilot
k
CM – activation
if the Ec/I0 Active option is selected,
if the RSCP Active option is selected.
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UL
UL
Q req Service M b Mobility M b Q req Service M b Mobility M b req - P req P term – R99 M b ic k = -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------term – R99 M b ic k – 1 UL Qk Mb req
min
req
max
req
min
If P term – R99 M b ic k P term M b then P term – R99 M b ic k = P term txi M b If P term – R99 M b ic k P term M b then Mb cannot select any cell and its active set is cleared R99
If TP P – UL M b TP Max – UL txi ic then Mb cannot be connected Endif Downlink Power Control If (mobile does not use a packet switched service that is inactive on the downlink) For each cell (txi,ic) in Mb active set Calculation of quality level on (txi,ic) traffic channel at Mb with the minimum power allowed on traffic channel for the Mb service min
P tch Service M b DL P b txi M b ic = ----------------------------------------------L T txi M b DL
BTS P b txi M b ic k DL DL - G DL Q tch txi M b ic k = -------------------------------------------------------------------------------------------------------------------------p Service M b G div DL DL N tot ic – 1 – F ortho BTS P b txi M b ic k – 1 If the user selects the option "Total noise" DL
BTS P b txi M b ic k DL DL - G DL Q tch txi M b ic k = -------------------------------------------------------p Service M b G div DL N tot ic End For DL
DL
Q k M b = f rake efficiency
DL
Q tch txi M b ic k
txi ActiveSet
Do For each cell (txi,ic) in Mb active set Calculation of the required power for DL traffic channel between (txi,ic) and Mb: DL
Q req Service M b Mobility M b req - P min P tch txi M b ic k = ------------------------------------------------------------------------------------tch Service M b DL Qk Mb If compressed mode is operated. DL
DL
Q req Service M b Mobility M b Q req Service Mb Mobility M b req - P min P tch txi M b ic k = -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------tch Service M b DL Qk Mb Compressed mode is operated if Mi and Sj support compressed mode, and
req
Resulting
CM – activation
txi M b ic Q pilot
•
Either Q pilot
•
Or P c txi M b ic RSCP pilot
k
CM – activation
max
if the Ec/I0 Active option is selected,
if the RSCP Active option is selected.
max
If P tch txi M b ic k P tch Service M b then txi ic is set to P tch DL
max
Recalculation of a decreased Q req (a part of the required quality is managed by the cells set to P tch ) req
P tch Service M b DL P b txi M b ic = ---------------------------------------------L T txi M b
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BTS P b txi M b ic DL DL - G DL Q tch txi M b ic k = ----------------------------------------------------------------------------------------------------------------p Service M b G div DL DL N tot ic – 1 – F ortho BTS P b txi M b ic DL
DL
DL
If the user is inactive, then his contribution to interference in the calculation of N tot ic is P b txi M b ic r c . EndFor DL
DL
Q k M b = f rake efficiency
DL
Q tch txi M b ic k
txi ActiveSet DL
DL
While Q k M b Q req Service M b Mobility M b and Mb active set is not empty R99
If TP P – DL M b TP Max – DL txi ic then Mb cannot be connected Endif Uplink and Downlink Interference Update Update of interference on active mobiles only (old contributions of mobiles and stations are replaced by the new ones). For each cell (txi,ic) UL
Update of N tot txi ic EndFor For each mobile Mi DL
Update of N tot ic EndFor EndFor Control of Radio Resource Limits (OVSF Codes, Cell Power, Channel Elements, Iub Backhaul Throughput) For each cell (txi,ic) P tx txi ic DL While ----------------------------k %Powermax P max Rejection of the mobile with the lowest service priority starting from the last admitted EndFor For each cell (txi,ic) While N
Codes
Codes
txi ic k N max txi ic
Rejection of the mobile with the lowest service priority starting from the last admitted EndFor For each NodeB, Ni While N
CE – DL
CE – DL
N i k N max
Ni
Rejection of the mobile with the lowest service priority starting from the last admitted While N
CE – UL
CE – UL
N i k N max
Ni
Rejection of the mobile with the lowest service priority starting from the last admitted EndFor For each NodeB, Ni Max
While TP Iub – DL N I k TP Iub – DL N I Rejection of the mobile with the lowest service priority starting from the last admitted Max
While TP Iub – UL N I k TPIub – UL N I Rejection of the mobile with the lowest service priority starting from the last admitted
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EndFor Uplink Load Factor Control UL
UL
For each cell (txi,ic) with X R99 txi ic X max Rejection of the mobile with the lowest service priority starting from the last admitted EndFor UL
UL
While at least one cell with X R99 txi ic X max exists.
4.3.2.3 HSDPA Part of the Algorithm HSDPA BE, HSDPA VBR, HSPA BE and HSPA VBR service users active on DL as well as all HSPA CBR service users (i.e., active and inactive), unless they have been rejected during the R99 part of the algorithm, are then evaluated by the HSDPA part of the algorithm.
4.3.2.3.1
HSDPA Power Allocation The total transmitted power of the cell ( P tx ic ) is the sum of the transmitted R99 power, the HSUPA power and the transmitted HSDPA power. P tx ic = P tx – R99 ic + P tx –H SDPA ic + P HSUPA ic •
In case of a static HSDPA power allocation strategy, Atoll checks in the simulation that: DL
P tx ic P max ic %Power max where: DL
%Power max is the maximum DL load allowed. Therefore, if the maximum DL load is set to 100%, we have: P tx ic P max ic •
In case of dynamic HSDPA power allocation strategy, Atoll checks in the simulation that: DL
P tx – R99 ic + P HSUPA ic P max ic %Power max And it calculates the available HSDPA power as follows: P HSDPA ic = P max ic – P Headroom ic – P tx – R99 ic – P HSUPA ic
4.3.2.3.2
Number of HS-SCCH Channels and Maximum Number of HSDPA Bearer Users The number of HS-SCCH channels ( n HS – SCCH ) is the maximum number of HS-SCCH channels that the cell can manage. This parameter is used to manage the number of BE and VBR service users simultaneously connected to an HSDPA bearer. This parameter is not taken into account for CBR service users as HS-SCCH-less operation (i.e., HS-DSCH transmissions without any accompanying HS-SCCH) is performed. Each HSDPA BE, HSDPA VBR, HSPA BE and HSPA VBR service user consumes one HS-SCCH channel. Therefore, at a time (over a transmission time interval), the number of these users connected to an HSDPA bearer cannot exceed the number of HSSCCH channels per cell. The maximum number of HSDPA bearer users ( n max ) corresponds to the maximum number of HSDPA bearer users that the cell can support. Here, all HSDPA bearer users, i.e., HSDPA BE, HSDPA VBR, HSPA BE and HSPA VBR and HSPA CBR service users, are taken into consideration. Let us assume there are 30 users in the cell: • • •
10 HSPA CBR service users with any activity status. 2 HSDPA VBR service users active on DL. 18 HSDPA BE and HSPA BE service users active on DL.
All users are connected to the A-DCH R99 bearer. Finally, the number of HS-SCCH channels and the maximum number of HSDPA bearer users respectively equal 4 and 25. The scheduler manages the maximum number of users within each cell. CBR service users have the highest priority and are processed first, in the order established during the generation of the user distribution. After processing the CBR service users, Atoll processes the remaining HSDPA bearer users (i.e., HSDPA VBR, HSPA VBR, HSDPA BE and HSPA BE service users). VBR
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service users have the highest priority and are managed before BE service users. For each type of service, the scheduler ranks the users according to the selected scheduling technique. Users are treated as described in the figure below.
Figure 4.3: Connection status of HSDPA bearer users •
•
•
All CBR service users may be served if there are enough HSDPA power, Iub backhaul throughput and OVSF codes available in order for them to obtain the lowest HSDPA bearer that provides a peak RLC throughput higher or equal to the minimum throughput demand defined for the service. In this case, they will be connected. Else, they will be rejected. The two VBR service users may be simultaneously served if there are enough HSDPA power, Iub backhaul throughput and OVSF codes available in order for them to obtain an HSDPA bearer that provides a peak RLC throughput higher or equal to the minimum throughput demand defined for the service. In this case, they will be connected. Else, they will be rejected. Then, among the BE service users: •
• •
4.3.2.3.3
The first two users may be simultaneously served if there are enough HSDPA power, Iub backhaul throughput and OVSF codes available in order for them to obtain an HSDPA bearer. In this case, they will be connected. Else, they will be delayed. The next eleven ones will be delayed since there are no longer HS-SCCH channels available. Their connection status will be "HS-SCCH Channels Saturation". Finally, the last five users will be rejected because the maximum number of HSDPA bearer users has been fixed to 25. Their connection status will be "HSDPA Scheduler Saturation".
HSDPA Bearer Allocation Process The HSDPA bearer allocation process depends on the type of service requested by the user. As explained before, CBR service users have the highest priority and are processed first, in the order established during the generation of the user distribution. After processing the CBR service users, the scheduler ranks the remaining users (i.e., VBR and BE service users) and shares the cell radio resources between them. VBR service users have the highest priority and are managed before BE service users. CBR Service Users Let us focus on the ten CBR service users mentioned in the example of the previous paragraph "Number of HS-SCCH Channels and Maximum Number of HSDPA Bearer Users" on page 238. Fast link adaptation is carried out on these users in order to determine if they can obtain an HSDPA bearer that provides a peak RLC throughput higher or equal to the service minimum throughput demand. As HS-SCCH less operation is performed, only HSDPA bearers using the QPSK modulation and two HSPDSCH channels at the maximum can be selected and allocated to the users. The users are processed in the order established during the generation of the user distribution and the cell’s available HSDPA power is shared between them as explained below. Several CBR service users can share the same HSDPA bearer. Then, Atoll calculates the HSDPA bearer consumption ( C in %) for each user and takes into account this parameter when it determines the resources consumed by the user (i.e., the HSDPA power used, the number of OVSF codes and the Iub backhaul throughput). In the bearer allocation process shown below, the 10 CBR service users are represented by Mj, with j = 1 to 10. And, the initial values of their respective HSDPA powers is 0, i.e. PHSDPA(B(MX)) = 0, where X = 0 to 10. These power values are assigned one by one by the scheduler, so that with their allocated values, looped back to the starting point, are used in successive steps.
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For the user, Mj, with j varying from 1 to 10: PHSDPA
j 1
(PHSDPA
X 0
(M X )) served
Sufficient HS-SCCH power to reach the minimum quality threshold?
No
Mj is rejected
Yes Enough 16-bit OVSF codes available to support the lowest HSDPA bearer allocated?
No
Mj is rejected
Yes Sufficient Iub backhaul throughput to support the lowest HSDPA bearer allocated?
No
Mj is rejected
Yes
Sufficient HSDPA power to obtain the lowest HSDPA bearer allocated?
No
Mj is rejected
Yes Determination of the Best HSDPA Bearer BB(Mj)
Cell and UE both capable of supporting BB(Mj)?
Yes
BB(Mj) selected B(Mj) = BB(Mj)
No Bearer Downgrading B(Mj)
RLC Peak Rate of B(Mj) > Mj Min Throughput Demand?
No
Mj is rejected
Yes Allocation of Min Throughput Demand to Mj Mj connected with B(Mj) (PHSDPA(Mj))served=PHS-PDSCH(B(Mj)) x C(B(Mj))
Update of Available Radio Resources
No
Mj = M10? Yes
Resource allocation for Variable Bit Rate and Best Effort service users
Figure 4.4: HSDPA Bearer Allocation Process for CBR Service Users VBR Service Users After processing the CBR service users, the scheduler shares the cell’s remaining resources between HSDPA and HSPA VBR service users. Let us focus on the two HSDPA - VBR service users mentioned in the example of the previous paragraph, "Number of HS-SCCH Channels and Maximum Number of HSDPA Bearer Users" on page 238. A new fast link adaptation is carried out on these users in order to determine if they can obtain an HSDPA bearer that provides a peak RLC throughput higher or equal to the service minimum throughput demand. They are processed in the order defined by the scheduler and the cell’s HSDPA power available after all CBR service users have been served is shared between them as explained below. In the bearer allocation process shown below, the 2 VBR service users are represented by Mj, with j = 1 to 2. And, the initial values of their respective HSDPA powers is 0, i.e. PHSDPA(B(MX)) = 0, where X = 0 to 2. These power values are assigned one by one by the scheduler, so that with their allocated values, looped back to the starting point, are used in successive steps.
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For the user, Mj, with j varying from 1 to 2:
PHSDPA
j 1
(PHSDPA
X 0
(M X )) served
Sufficient HS-SCCH power to reach the minimum quality threshold?
No
Mj is rejected
Yes Enough 16-bit OVSF codes available to support the lowest HSDPA bearer allocated?
No
Mj is rejected
Yes Sufficient Iub backhaul throughput to support the lowest HSDPA bearer allocated?
No
Mj is rejected
Yes
Sufficient HSDPA power to obtain the lowest HSDPA bearer allocated?
No
Mj is rejected
Yes Determination of the Best HSDPA Bearer BB(Mj)
Bearer Downgrading B(Mj) until: 1. Cell and UE both capable of supporting B(Mj) And 2. RLC Peak Rate of B(Mj) > Mj Min Throughput Demand
RLC Peak Rate of B(Mj) > Mj Min Throughput Demand?
No
Mj is rejected
Yes Mj connected with B(Mj) (PHSDPA(Mj))served=PHS-PDSCH(B(Mj)) +nHS-SCCHxPHS-SCCH(Mj)
No
Mj = M2? Yes
Resource allocation for Best Effort service users
Figure 4.5: HSDPA Bearer Allocation Process for VBR Service Users BE Service Users After processing the VBR service users, the scheduler shares the cell’s remaining resources between BE service users. Let us focus on the HSDPA and HSPA BE service users, especially on the first four users mentioned in the example of the previous paragraph, "Number of HS-SCCH Channels and Maximum Number of HSDPA Bearer Users" on page 238. A new fast link adaptation is carried out on these users in order to determine if they can obtain an HSDPA bearer. They are processed in the order defined by the scheduler and the cell’s HSDPA power available after all CBR and VBR service users have been served is shared between them as explained below. In the bearer allocation process shown below, the 4 BE service users are represented by Mj, with j = 1 to 4. And, the initial values of their respective HSDPA powers is 0, i.e. PHSDPA(B(MX)) = 0, where X = 0 to 4. These power values are assigned one by one by the scheduler, so that with their allocated values, looped back to the starting point, are used in successive steps.
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For the user, Mj, with j varying from 1 to 4:
Figure 4.6: HSDPA Bearer Allocation Process for BE Service Users
4.3.2.3.4
Fast Link Adaptation Modelling Fast link adaptation (or Adaptive Modulation and Coding) is used in HSDPA. The power on the HS-DSCH channel is transmitted at a constant power while the modulation, the coding and the number of codes are changed to adapt to the radio conditions variations. Based on the reported channel quality indicator (CQI), the node-B may change every 2ms the modulation (QPSK, 16QAM, 64QAM), the coding and the number of codes during a communication. Atoll calculates for each user either the best pilot quality (CPICH Ec/Nt) or the best HS-PDSCH quality (HS-PDSCH Ec/Nt); this depends on the option selected in Global parameters (HSDPA part): CQI based on CPICH quality or CQI based on HS-PDSCH quality (CQI means channel quality indicator). Then, it determines the HS-PDSCH CQI, calculates the best bearer that can be used and selects the suitable bearer so as to comply with cell and terminal user equipment HSDPA capabilities. Once the bearer selected, Atoll finds the highest downlink throughput that can be provided to the user and may calculate the application throughput.
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CQI Based on CPICH Quality When the option “CQI based on CPICH quality” is selected, Atoll proceeds as follows. 1. CPICH Quality Calculation Ec Let us assume the following notation: ------ ic corresponds to the CPICH quality. Nt pilot Two options, available in Global parameters, may be used to calculate Nt: option Without useful signal or option Total noise. Therefore, we have: BTS P c ic Eci ---- ic = ----------------------------------------- for the total noise option, Nt pilot DL N tot ic And BTS P c ic Eci ----for the without useful signal option. ic = -------------------------------------------------------------------------------- Nt pilot DL N tot ic – 1 – BTS P c ic i
With DL
DL
DL
DL
DL
term
N tot ic = I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0
DL DL DL P SCH ic P SCH ic DL term I intra ic = P tot ic + BTS 1 – F MUD 1 – P tot ic – ------------------- – BTS P tot ic – ------------------LT LT txi txi txi DL
I extra ic =
DL
P tot ic
txj j i
Ptot icadj DL
DL
j I inter – carrier ic = txj -----------------------------------RF ic ic adj
icadj is a carrier adjacent to ic. RF ic ic adj is the interference reduction factor, defined between ic and icadj and set to a value different from 0. DL
I inter – techno log y ic is the inter-technology interference at the receiver on ic. DL
I inter – techno log y ic =
ni
ic i is the i
th
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic i
interfering carrier of an external transmitter
Tx m
ICPic ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the i
frequency gap between ic i (external network) and ic . P pilot ic P c ic = --------------------i LT i
L path L Tx L term L body L indoor E Shadowing 3 L T = ------------------------------------------------------------------------------------------------------------------- ( ) G Tx G term term
BTS , and N 0
3.
are defined in "Inputs" on page 215.
In the HSDPA coverage prediction, L T is calculated as follows:
L path L Tx L term L body L indoor M Shadowing – Ec Io -) L T = -----------------------------------------------------------------------------------------------------------------------------------G Tx G term
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Atoll performs intra-cell interference computations based on the total power. You can instruct Atoll to use maximum power by adding the following lines in the Atoll.ini file: [CDMA] PmaxInIntraItf = 1
In this case, Atoll considers the following formula: P max ic – P SCH ic P max ic DL term - I intra ic = -------------------+ BTS 1 – F MUD 1 – --------------------------------------------- LT LT P max ic – P SCH ic - – BTS --------------------------------------------- LT
2. CPICH CQI Determination Let us assume the following notation: CQI pilot corresponds to the CPICH CQI. CQI pilot is read in the table Ec . This table is defined for the terminal reception equipment and the selected mobility. CQI pilot = f ------ ic Nt pilot 3. HS-PDSCH Quality Calculation Atoll proceeds as follows: 1st step: Atoll calculates the HS-SCCH power ( P HS – SCCH ). P HS – SCCH ic is the HS-SCCH power on carrier ic. It is either fixed by the user (when the option “HS-SCCH Power Dynamic Allocation”in the cell property dialogue is unchecked) or dynamically calculated (when the option “HS-SCCH Power Dynamic Allocation” is selected). req
Ec In this case, the HS-SCCH power is controlled so as to reach the required HS-SCCH Ec/Nt (noted ------ ic ). It is Nt HS – SCCH specified in mobility properties. We have: BTS P c ic Eci ---- ic = ------------------------------- for the total noise option, Nt HS – SCCH DL N tot ic And BTS P c ic Eci ---- ic = ---------------------------------------------------------------------------------------------------------------------------- for the without useful signal option. Nt HS – SCCH DL term N tot ic – 1 – F ortho 1 – F MUD BTS P c ic i
With DL
DL
DL
DL
DL
term
N tot ic = I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0
DL DL DL P SCH ic P SCH ic DL term I intra ic = P tot ic + BTS 1 – F MUD 1 – F ortho P tot ic – ------------------- – BTS P tot ic – ------------------- LT LT txi txi txi DL
I extra ic =
DL
P tot ic
txj j i
Ptot icadj DL
DL
j -----------------------------------I inter – carrier ic = txj RF ic ic adj
icadj is a carrier adjacent to ic. RF ic ic adj is the interference reduction factor, defined between ic and icadj and set to a value different from 0. DL
I inter – techno log y ic is the inter-technology interference at the receiver on ic.
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DL
I inter – techno log y ic =
n
ic i is the i
th
i
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic i
interfering carrier of an external transmitter
Tx m
ICPic ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the i
frequency gap between ic i (external network) and ic . P HS – SCCH ic P c ic = ------------------------------i LT i
and L path L Tx L term L body L indoor E Shadowing 4 L T = ------------------------------------------------------------------------------------------------------------------- ( ) G Tx G term term
term
BTS , F ortho , F MUD and N 0
are defined in "Inputs" on page 215.
Therefore, req
EcDL ---- ic N tot ic Nt HS – SCCH P HS – SCCH ic = ------------------------------------------------------------------ L T for the total noise option, i BTS And req EcDL ---- ic Nt HS – SCCH N tot ic ------------------------------------------------------------------------------------------------------------------------------------------P HS – SCCH ic = L T for the without useful signal option. req i Ecterm 1 + 1 – F ---- 1 – F ic BTS ortho MUD Nt HS – SCCH
2nd step: Atoll calculates the HS-PDSCH power ( P HS – PDSCH ). P HSDPA ic is the power available for HSDPA on the carrier ic. This parameter is either a simulation output, or a user-defined cell input. P HSDPA ic = P HS – PDSCH ic + n HS – SCCH P HS – SCCH ic Therefore, we have: P HS – PDSCH ic = P HSDPA ic – n HS – SCCH P HS – SCCH ic n HS – SCCH is the number of HS-SCCH channels. 3rd step: Then, Atoll evaluates the HS-PDSCH quality Ec Let us assume the following notation: ------ ic corresponds to the HS-PDSCH quality. Nt HS – PDSCH We have: BTS P c ic Eci ---- ic = ------------------------------- for the total noise option, Nt HS – PDSCH DL N tot ic And BTS P c ic Eci ---- - for the without useful signal option. Nt ic HS – PDSCH = ---------------------------------------------------------------------------------------------------------------------------P c ic DL term i N tot ic – 1 – F ortho 1 – F MUD BTS --------------n
4.
In the HSDPA coverage prediction, L T is calculated as follows:
L path L Tx L term L body L indoor M Shadowing – Ec Io -) L T = -----------------------------------------------------------------------------------------------------------------------------------G Tx G term
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Here, Atoll works on the assumption that five HS-PDSCH channels are used (n=5). With DL
DL
DL
DL
DL
term
N tot ic = I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0
DL DL DL P SCH ic P SCH ic DL term I intra ic = P tot ic + BTS 1 – F MUD 1 – F ortho P tot ic – ------------------- – BTS P tot ic – ------------------ LT LT txi txi txi DL
I extra ic =
DL
P tot ic
txj j i
Ptot icadj DL
DL
j -----------------------------------I inter – carrier ic = txj RF ic ic adj
icadj is a carrier adjacent to ic. RF ic ic adj is the interference reduction factor, defined between ic and icadj and set to a value different from 0. DL
I inter – techno log y ic is the inter-technology interference at the receiver on ic. DL
I inter – techno log y ic =
ni
ic i is the i
th
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic i
interfering carrier of an external transmitter
Tx m
ICP ic ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the i
frequency gap between ic i (external network) and ic . P HS – PDSCH ic P c ic = ---------------------------------i LT i
And L path L Tx L term L body L indoor E Shadowing 5 - ( ) L T = ------------------------------------------------------------------------------------------------------------------G Tx G term term
term
BTS , F ortho , F MUD and N 0
are defined in "Inputs" on page 215.
Atoll performs intra-cell interference computations based on the total power. You can instruct Atoll to use maximum power by adding the following lines in the Atoll.ini file: [CDMA] PmaxInIntraItf = 1
In this case, Atoll considers the following formula: P max ic – P SCH ic P max ic – P SCH ic P max ic DL term I intra ic = -------------------+ BTS 1 – F MUD 1 – ----------------------------------------------- – BTS ----------------------------------------------- LT LT LT 4. HS-PDSCH CQI Determination The best bearer that can be used depends on the HS-PDSCH CQI. Let us assume the following notation: CQI HS – PDSCH corresponds to the HS-PDSCH CQI. Atoll calculates CQI HS – PDSCH as follows: CQI HS – PDSCH = CQI pilot – P pilot + P HS – PDSCH
5.
In the HSDPA coverage prediction, L T is calculated as follows:
L path L Tx L term L body L indoor M Shadowing – Ec Io -) L T = -----------------------------------------------------------------------------------------------------------------------------------G Tx G term
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5. HSDPA Bearer Selection Atoll selects the HSDPA bearer associated to this CQI (in the table Best Bearer=f(HS-PDSCH CQI) defined for the terminal reception equipment and the user mobility) and compatible with the user equipment and cell capabilities. HSDPA bearers can be classified into two categories: •
HSDPA bearers using QPSK and 16QAM modulations: They can be selected for all users connected to HSPA and HSPA+ capable cells. The number of HS-PDSCH channels required by the bearer must not exceed the maximum number of HS-PDSCH codes available for the cell. For VBR service users, the selected HSDPA bearer must provide a peak RLC throughput between the minimum and the maximum throughput demands defined for the service. For CBR service users, HS-SCCH-less operation (i.e., HS-DSCH transmissions without any accompanying HS-SCCH) is performed. In this case, the UE is not informed about the transmission format and has to revert to blind decoding of the transport format used on the HS-DSCH. Complexity of blind detections in the UE is decreased by limiting the transmission formats that can be used (i.e., the HSDPA bearers available). Therefore, only HSDPA bearers using the QPSK modulation and two HS-PDSCH channels at the maximum can be selected and allocated to these users. Additionally, the selected HSDPA bearer must provide a peak RLC throughput higher or equal to the minimum throughput demand defined for the service.
•
HSDPA bearers using 64QAM modulation (improvement introduced by the release 7 of the 3GPP UTRA specifications, referred to as HSPA+): These HSDPA bearers can be allocated to VBR and BE service users connected to cells with HSPA+ capabilities only. The number of HS-PDSCH channels required by the bearer must not exceed the maximum number of HS-PDSCH codes available for the cell. For VBR service users, the selected HSDPA must provide a peak RLC throughput between the minimum and the maximum throughput demands defined for the service. These HSDPA bearers cannot be allocated to CBR service users.
Atoll considers an HSDPA bearer as compatible with the user equipment if: • • •
The transport block size does not exceed the maximum transport block size supported by the user equipment. The number of HS-PDSCH channels required by the bearer does not exceed the maximum number of HS-PDSCH channels that the terminal can use. The modulation is supported by the user equipment.
When there are several HSDPA bearers compatible, Atoll selects the HSDPA bearer that provides the highest RLC peak throughput. When several HSDPA bearers can supply the same RLC peak throughput, Atoll chooses the HSDPA bearer with the highest modulation scheme. Finally, if no HSDPA bearer is compatible, Atoll allocates a lower HSDPA bearer compatible with the user equipment and cell capabilities which needs fewer resources. Let’s consider the following examples. Example1: One HSDPA BE service user with category 13 user equipment and a 50km/h mobility. The user equipment capabilities are: • • • •
Maximum transport block size: 35280 bits Maximum number of HS-PDSCH channels: 15 Highest modulation supported: 64QAM MIMO Support: No
Figure 4.7: HSDPA UE Categories Table The cell to which the user is connected supports HSPA+ functionalities (i.e. 64QAM modulation in the DL and MIMO systems) and the maximum number of HS-PDSCH channels is 15.
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1st case: The CQI experienced by the user equals 26. Therefore, Atoll can choose between two HSDPA bearers, the bearer indexes 26 and 31. Characteristics of the bearer index 26 are: • • • •
Transport block size: 17237 bits Number of HS-PDSCH channels used: 12 16QAM modulation is used Peak RLC Throughput: 8.32 Mb/s
Characteristics of the bearer index 31 are: • • • •
Transport block size: 15776 bits Number of HS-PDSCH channels used: 10 64QAM modulation is used Peak RLC Throughput: 7.36 Mb/s
Both HSDPA bearers are compatible with the user equipment and cell capabilities. Atoll selects the HSDPA bearer that provides the highest RLC peak throughput, i.e. the bearer index 26.
Figure 4.8: HSDPA Radio Bearers Table 2nd case: The CQI experienced by the user equals 27. Therefore, Atoll can choose between two HSDPA bearers, the bearer indexes 27 and 32. Characteristics of the bearer index 27 are: • • • •
Transport block size: 21754 bits Number of HS-PDSCH channels used: 15 16QAM modulation is used Peak RLC Throughput: 10.24 Mb/s
Characteristics of the bearer index 32 are: • • • •
Transport block size: 21768 bits Number of HS-PDSCH channels used: 12 64QAM modulation is used Peak RLC Throughput: 10.24 Mb/s
Both HSDPA bearers are compatible with the user equipment and cell capabilities and the peak RLC throughput they provide is the same. Atoll selects the HSDPA bearer using the highest modulation scheme, i.e. the bearer index 32. Example 2: One HSDPA BE user experiencing a CQI of 26. Therefore, Atoll can choose between two HSDPA bearers, the bearer indexes 26 and 31. Characteristics of the bearer index 26 are: • • • •
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Characteristics of the bearer index 31 are: • • • •
Transport block size: 15776 bits Number of HS-PDSCH channels used: 10 64QAM modulation is used Peak RLC Throughput: 7.36 Mb/s
1st case: The user equipment category is 9. The cell to which the user is connected supports HSPA+ functionalities (i.e. 64QAM modulation in the DL and MIMO systems) and the maximum number of HS-PDSCH channels is 15. The user equipment characteristics are the following: • • • •
Maximum transport block size: 20251 bits Maximum number of HS-PDSCH channels: 15 Highest modulation supported: 16QAM MIMO Support: No
The bearer index 31 cannot be selected because it requires a modulation scheme not supported by the terminal. Only the bearer index 26 is compatible with the user equipment capabilities. Atoll selects it. 2nd case: The user equipment category is 8. The cell to which the user is connected supports HSPA+ functionalities (i.e. 64QAM modulation in the DL and MIMO systems) and the maximum number of HS-PDSCH channels is 15. The user equipment characteristics are the following: • • • •
Maximum transport block size: 14411 bits Maximum number of HS-PDSCH channels: 10 Highest modulation supported: 16QAM MIMO Support: No
Here, none of HSDPA bearers are compatible with the user equipment capabilities. The bearer index 31 cannot be selected because it requires a modulation scheme not supported by the terminal. With the bearer index 26, the number of HS-PDSCH channels (12) exceeds the maximum number of HS-PDSCH channels the terminal can use (10), and the transport block size (17237 bits) exceeds the maximum transport block size (14411 bits) the terminal can carried. In the HSDPA Radio Bearer table, Atoll selects a lower HSDPA bearer compatible with cell and UE category capabilities. It selects the bearer index 25. • • •
The number of HS-PDSCH channels (10) does not exceed the maximum number of HS-PDSCH channels the terminal can use (10) and the maximum number of HS-PDSCH channels available at the cell level (15), The transport block size (14411 bits) does not exceed the maximum transport block size (14411 bits) the terminal can carried. 16QAM modulation is supported by the terminal and the cell.
3rd case: The user equipment category is 13. The cell to which the user is connected supports HSPA functionalities and the maximum number of HS-PDSCH channels is 15. The user equipment capabilities are: • • • •
Maximum transport block size: 35280 bits Maximum number of HS-PDSCH channels:15 Highest modulation supported: 64QAM MIMO Support: No
The bearer index 31 cannot be selected because it requires a modulation scheme not supported by the cell. On the other hand, the bearer index 26 is compatible with cell and UE category capabilities. Therefore, it is allocated. 6. HS-PDSCH Quality Update Once the bearer selected, Atoll exactly knows the number of HS-PDSCH channels. Therefore, when the method “Without useful signal” is used, it may recalculate the HS-PDSCH quality with the real number of HS-PDSCH channels (A default value (5) was taken into account in the first HS-PDSCH quality calculation). CQI Based on HS-PDSCH Quality When the option “CQI based on HS-PDSCH quality” is selected, Atoll proceeds as follows. 1. HS-PDSCH Quality Calculation Atoll proceeds as follows: 1st step: Atoll calculates the HS-SCCH power ( P HS – SCCH ).
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P HS – SCCH ic is the HS-SCCH power on carrier ic. It is either fixed by the user (when the option “HS-SCCH Power Dynamic Allocation”in the cell property dialogue is unchecked) or dynamically calculated (when the option “HS-SCCH Power Dynamic Allocation” is selected). req
Ec In this case, the HS-SCCH power is controlled so as to reach the required HS-SCCH Ec/Nt (noted ------ ic ). It is Nt HS – SCCH specified in mobility properties. We have: BTS P c ic Eci ---- ic = ------------------------------- for the total noise option, Nt HS – SCCH DL N tot ic And BTS P c ic Eci ---- ic = ---------------------------------------------------------------------------------------------------------------------------- for the without useful signal option. Nt HS – SCCH DL term N tot ic – 1 – F ortho 1 – F MUD BTS P c ic i
With DL
DL
DL
DL
DL
term
N tot ic = I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0
DL DL DL P SCH ic P SCH ic DL term I intra ic = P tot ic + BTS 1 – F MUD 1 – F ortho P tot ic – ------------------- – BTS P tot ic – ------------------ LT LT txi txi txi DL
I extra ic =
DL
P tot ic
txj j i
Ptot icadj DL
DL
j -----------------------------------I inter – carrier ic = txj RF ic ic adj
icadj is a carrier adjacent to ic. RF ic ic adj is the interference reduction factor, defined between ic and icadj and set to a value different from 0. DL
I inter – techno log y ic is the inter-technology interference at the receiver on ic. DL
I inter – techno log y ic =
ni
ic i is the i
th
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic i
interfering carrier of an external transmitter
Tx m
ICP ic ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the i
frequency gap between ic i (external network) and ic . P HS – SCCH ic P c ic = ------------------------------i LT i
And L path L Tx L term L body L indoor E Shadowing 6 - ( ) L T = ------------------------------------------------------------------------------------------------------------------G Tx G term term
term
BTS , F ortho , F MUD and N 0
are defined in "Inputs" on page 215.
Therefore,
6.
In the HSDPA coverage prediction, L T is calculated as follows:
L path L Tx L term L body L indoor M Shadowing – Ec Io -) L T = -----------------------------------------------------------------------------------------------------------------------------------G Tx G term
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req EcDL ---- ic HS – SCCH N tot ic Nt P HS – SCCH ic = ------------------------------------------------------------------ L T for the total noise option, i BTS
And req
EcDL ---- Nt ic HS – SCCH N tot ic - L T for the without useful signal option. P HS – SCCH ic = ------------------------------------------------------------------------------------------------------------------------------------------req i Ec term 1 + 1 – F ortho 1 – F MUD ------ ic BTS Nt HS – SCCH 2nd step: Atoll calculates the HS-PDSCH power ( P HS – PDSCH ) P HSDPA ic is the power available for HSDPA on the carrier ic. This parameter is either a simulation output, or a user-defined cell input. P HSDPA ic = P HS – PDSCH ic + n HS – SCCH P HS – SCCH ic Therefore, we have: P HS – PDSCH ic = P HSDPA ic – n HS – SCCH P HS – SCCH ic n HS – SCCH is the number of HS-SCCH channels. 3rd step: Then, Atoll evaluates the HS-PDSCH quality Ec Let us assume the following notation: ------ ic corresponds to the HS-PDSCH quality. Nt HS – PDSCH Two options, available in Global parameters, may be used to calculate Nt: option Without useful signal or option Total noise. We have: BTS P c ic Eci ---- - for the total noise option, Nt ic HS – PDSCH = ------------------------------DL N tot ic And BTS P c ic Eci ----= ---------------------------------------------------------------------------------------------------------------------------- for the without useful signal option. ic Nt HS – PDSCH P c ic DL term i N tot ic – 1 – F ortho 1 – F MUD BTS --------------n Here, Atoll works on the assumption that five HS-PDSCH channels are used (n=5). Then, it calculates the HS-PDSCH CQI and the bearer to be used. Once the bearer selected, Atoll exactly knows the number of HS-PDSCH channels and recalculates the HS-PDSCH quality with the real number of HS-PDSCH channels. With DL
DL
DL
DL
DL
term
N tot ic = I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0
DL DL DL P SCH ic P SCH ic DL term I intra ic = P tot ic + BTS 1 – F MUD 1 – F ortho P tot ic – ------------------- – BTS P tot ic – ------------------- LT LT txi txi txi DL
I extra ic =
DL
P tot ic
txj j i
Ptot icadj DL
DL
j -----------------------------------I inter – carrier ic = txj RF ic ic adj
icadj is a carrier adjacent to ic. RF ic ic adj is the interference reduction factor, defined between ic and icadj and set to a value different from 0. DL
I inter – techno log y ic is the inter-technology interference at the receiver on ic.
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I inter – techno log y ic =
n
ic i is the i
th
i
©Forsk 2015
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic i
interfering carrier of an external transmitter
Tx m
ICP ic ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the i
frequency gap between ic i (external network) and ic . P HS – PDSCH ic P c ic = ---------------------------------i LT i
And L path L Tx L term L body L indoor E Shadowing 7 L T = ------------------------------------------------------------------------------------------------------------------- ( ) G Tx G term term
term
BTS , F ortho , F MUD and N 0
are defined in "Inputs" on page 215.
Atoll performs intra-cell interference computations based on the total power. You can instruct Atoll to use maximum power by adding the following lines in the Atoll.ini file: [CDMA] PmaxInIntraItf = 1
In this case, Atoll considers the following formula: P max ic – P SCH ic P max ic – P SCH ic P max ic DL term - – BTS ---------------------------------------------- I intra ic = -------------------+ BTS 1 – F MUD 1 – --------------------------------------------- LT LT LT 2. HS-PDSCH CQI Determination Let us assume the following notation: CQI HS – PDSCH corresponds to the HS-PDSCH CQI. CQI HS – PDSCH is read in the table Ec . This table is defined for the terminal reception equipment and the specified CQI HS – PDSCH = f ------ ic Nt HS – PDSCH mobility. 3. HSDPA Bearer Selection The bearer is selected as described in "HSDPA Bearer Selection" on page 246.
4.3.2.3.5
MIMO Modelling MIMO - Transmit Diversity If the user is connected to a cell that supports HSPA+ with transmit diversity and if he has a MIMO-capable terminal (i.e., a terminal with an HSDPA UE category supporting MIMO), he will benefit from downlink diversity gain on the HS-PDSCH Ec/Nt. EcEc DL DL ----= ------ ic + G TD + G TD in dB ic Nt HS – PDSCH Nt HS – PDSCH Where DL
G TD is the downlink transmit diversity gain (in dB) corresponding to the numbers of transmission and reception antenna ports (respectively defined in the transmitter and terminal properties). DL
G TD is the additional diversity gain in downlink (in dB). It is defined for the clutter class of the user.
7.
In the HSDPA coverage prediction, L T is calculated as follows:
L path L Tx L term L body L indoor M Shadowing – Ec Io -) L T = -----------------------------------------------------------------------------------------------------------------------------------G Tx G term
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MIMO - Spatial Multiplexing If the user is connected to a cell that supports HSPA+ with spatial multiplexing and if he has a MIMO-capable terminal (i.e., a terminal with an HSDPA UE category supporting MIMO), he will benefit from the spatial multiplexing gain in its peak RLC throughput. In this case, the peak RLC throughput obtained by the user is the following: DL
DL
Max
TP P – R LC = TP P –R LC Index HSDPABearer 1 + f SM – Gain G SM – 1 Where DL
TP P – R LC Index HSDPABearer is the peak RLC throughput that the selected HSDPA bearer ( Index HSDPABearer ) can provide in the cell (Txi, ic). It is read in the HSDPA Radio Bearer table. Max
G SM
is the maximum spatial multiplexing gain (in dB) for a given number of transmission and reception antennas
(respectively defined in the transmitter and terminal properties). f SM – Gain is the spatial multiplexing gain factor defined for the clutter
4.3.2.3.6
Scheduling Algorithms The scheduler manages the maximum number of users within each cell. CBR service users have the highest priority and are processed first, in the order established during the generation of the user distribution. After processing the CBR service users, the scheduler processes the remaining users (i.e., VBR and BE service users). VBR service users have the highest priority and are managed before BE service users. For each type of service, the scheduler ranks the users according the scheduling technique. Three scheduling algorithms are available, Max C/I, Round Robin and Proportional Fair. Impact they have on the simulation result is described in the tables below. Let us consider a cell with 16 HSDPA and HSPA BE service users. All of them are active on DL and connected to the A-DCH R99 bearer. There is neither CBR service user, nor VBR service user in the cell and the number of HS-SCCH channels and the maximum number of HSDPA bearer users have been respectively set to 4 and 15. Max C/I 15 users (where 15 corresponds to the maximum number of HSDPA bearer users defined) enters the scheduler in the same order as in the simulation. Then, they are sorted in descending order by the channel quality indicator (CQI), i.e. in a best bearer descending order. Mobiles
Simulation Rank
Best Bearer (kbps)
DL Obtained Throughput (kbps)
Connection Status
M1
2
2400
2400+3.4
Connected
M2
15
2400
1440+3.4
Connected
M3
8
2080
160+3.4
Connected
M4
9
2080
3.4
Delayed
M5
10
2080
3.4
Delayed
M6
12
2080
3.4
Delayed
M7
13
2080
3.4
Delayed
M8
14
2080
3.4
Delayed
M9
7
1920
3.4
Delayed
M10
1
1600
3.4
Delayed
M11
3
1600
3.4
Delayed
M12
4
1600
3.4
Delayed
M13
5
1600
3.4
Delayed
M14
6
1600
3.4
Delayed
M15
11
1440
3.4
Delayed
M16
16
2080
0
Scheduler Saturation
Round Robin Users are taken into account in the same order than the one in the simulation (random order).
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Mobiles
Simulation Rank
Best Bearer (kbps)
DL Obtained Throughput (kbps)
Connection Status
M1
1
1600
1600+3.4
Connected
M2
2
2400
960+3.4
Connected
M3
3
1600
3.4
Delayed
M4
4
1600
3.4
Delayed
M5
5
1600
3.4
Delayed
M6
6
1600
3.4
Delayed
M7
7
1920
3.4
Delayed
M8
8
2080
3.4
Delayed
M9
9
2080
3.4
Delayed
M10
10
2080
3.4
Delayed
M11
11
1440
3.4
Delayed
M12
12
2080
3.4
Delayed
M13
13
2080
3.4
Delayed
M14
14
2080
3.4
Delayed
M15
15
2400
3.4
Delayed
M16
16
2080
0
Scheduler Saturation
Proportional Fair 15 users (where 15 corresponds to the maximum number of HSDPA bearer users defined) enters the scheduler in the same order as in the simulation. Then, they are sorted in an ascending order according to a new random parameter which corresponds to a combination of the user rank in the simulation and the channel quality indicator (CQI). For a user i, the random parameter RP i is calculated as follows: Simu
RP i = 50 R i
CQI
+ 50 R i
Where, Simu
Ri
CQI
Ri
is the user rank in the simulation.
is the user rank according to the CQI. You can change the default weights by editing the atoll.ini file. For more information, see the Administrator Manual.
254
CQI Rank
RP
Best Bearer (kbps)
DL Obtained Throughput (kbps)
2
1
150
2400
2400
Connected
1
10
550
1600
960
Connected
M3
8
3
550
2080
160
Connected
M4
9
4
650
2080
3.4
Delayed
M5
3
11
700
1600
3.4
Delayed
M6
10
5
750
2080
3.4
Delayed
M7
4
12
800
1600
3.4
Delayed
M8
7
9
800
1920
3.4
Delayed
Mobiles
Simulation Rank
M1 M2
Connection Status
M9
15
2
850
2400
3.4
Delayed
M10
5
13
900
1600
3.4
Delayed
M11
12
6
900
2080
3.4
Delayed
M12
6
14
1000
1600
3.4
Delayed
M13
13
7
1000
2080
3.4
Delayed
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4.3.2.3.7
Mobiles
Simulation Rank
CQI Rank
RP
Best Bearer (kbps)
DL Obtained Throughput (kbps)
Connection Status
M14
14
8
1100
2080
3.4
Delayed
M15
11
15
1300
1440
3.4
Delayed
M16
16
-
-
2080
0
Scheduler Saturation
Dual-Cell HSDPA For transmitters that support multi-cell HSDPA mode, the scheduler manages a single queue of users at the Node B. MC-HSDPA and DB-MC-HSDPA users are processed as DC-HSDPA users if they are connected to two carriers. Otherwise, they are considered as single-cell HSDPA users. All users belonging to the transmitter, i.e., DC-HSDPA and single-carrier HSDPA users, are ranked together in a unique list. DC-HSDPA users are considered twice in the list as they may be assigned two different HSDPA bearers in the two cells. CBR service users have the highest priority and are processed first, in the order established during the generation of the user distribution. After processing the CBR service users, the scheduler processes the remaining users (i.e., VBR and BE service users). VBR service users have the highest priority and are managed before BE service users. For each type of service, the scheduler ranks the users according the scheduling technique (Max C/I, Round Robin and Proportional Fair). After the users have been ranked, the scheduler allocates HSDPA resources to each user following the calculated order as long as there are resources available. Even if there is a unique list of users at the transmitter level, the resources of each cell are not shared and each carrier has its own pool of resources (number of HS-SCCH channels, maximum number of HSDPA bearer users, HSDPA power, number of OVSF codes). Only site-level resources (such as the Iub throughput and the channel elements) are shared between the users of the two cells. Let us consider a transmitter with 16 BE service users. The transmitter supports the multi-cell HSDPA mode. There is neither CBR service user, nor VBR service users. All users are active in DL and connected to the A-DCH R99 bearer. Among the users, there are 6 DC-HSDPA users (i.e., terminal with UE categories 21 to 24). Simulation Rank
DC-HSDPA Support
Carriers
Comments
1
Yes
1 and 2
Anchor carrier: 2
2
No
2
3
No
1
4
Yes
1 and 2
5
No
1
6
No
2
7
No
1
8
No
2
9
Yes
1 and 2
10
No
1
11
No
2
12
Yes
1 and 2
13
No
2
14
Yes
1 and 2
15
No
1
16
Yes
1 and 2
Anchor carrier: 2
Anchor carrier: 1
Anchor carrier: 1 Anchor carrier: 1 Anchor carrier: 2
In each cell, the number of HS-SCCH channels and the maximum number of HSDPA bearer users have been respectively set to 4 and 7. The scheduling algorithms defined for the two cells are the same as the one selected for the transmitter. Each DC-HSDPA user is counted twice, once in each cell, as he may be assigned two different HSDPA bearers in the two cells. Therefore, the scheduler manages the users ranked 1st to 11th (i.e. 4 single-carrier users connected to the first carrier, 4 singlecarrier users connected to the second carrier and 3 DC-HSDPA users). Users ranked 12th to 16th are rejected because the maximum number of HSDPA bearer users that the scheduler can manage in a cell is exceeded. Impact the scheduling algorithms have on the simulation results is described in the tables below.
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Max C/I 7 users from each cell (where 7 corresponds to the maximum number of HSDPA bearer users defined for each cell), i.e., a total of 14 users enter the scheduler in the same order as in the simulation. Then, they are sorted in the order of decreasing channel quality indicator (CQI), i.e. in a best bearer descending order. Mobiles
Carrier
Simulation Rank
CQI
Best Bearer (kbps)
DL Obtained Throughput (kbps)
Connection Status
M1
1
5
21
3040
3040+3.4
Connected
M2 (DC-HSDPA)
2
4
19
2400
2400+3.4
Connected
M3
2
8
18
2080
1440+3.4
Connected
M2 (DC-HSDPA)
1
4
17
1920
1920
Connected
M4 (DC-HSDPA)
1
9
17
1920
960+3.4
Connected
M5
1
3
16
1600
3.4
Delayed
M4 (DC-HSDPA)
2
9
16
1600
1120
Connected
M6
2
2
15
1440
3.4
Delayed
M7
1
7
14
1120
3.4
Delayed
M8
1
10
14
1120
3.4
Delayed
M9 (DC-HSDPA)
2
1
13
960
3.4
Delayed
M10
2
6
13
960
3.4
Delayed
M9 (DC-HSDPA)
1
1
12
800
0
Delayed
M11
2
11
12
800
3.4
Delayed
M12 (DC-HSDPA)
1 2
12
14 15
1120 1440
0
Scheduler Saturation
M13
2
13
17
1920
0
Scheduler Saturation
M14 (DC-HSDPA)
1 2
14
13 15
960 1440
0
Scheduler Saturation
M15
1
15
17
1920
0
Scheduler Saturation
M16 (DC-HSDPA)
1 2
16
12 14
800 1120
0
Scheduler Saturation
The scheduled DC-HSDPA users have the following status: • • •
The user ranked 4th (here M2) is connected to an HSDPA bearer in each cell. He obtains a total DL throughput of 4323.4 kbps (2403.4+1920). The user ranked 9th (here M4) is connected to an HSDPA bearer in each cell. He obtains a total DL throughput of 2083.4 kbps (963.4+1120). The first user (here M9) is delayed in the two cells. He obtains a total DL throughput of 3.4 kbps.
Round Robin 7 users from each cell (where 7 corresponds to the maximum number of HSDPA bearer users defined for each cell), i.e., a total of 14 users enter the scheduler in the same order as in the simulation.
256
Mobiles
Carrier
Simulation Rank
CQI
Best Bearer (kbps)
DL Obtained Throughput (kbps)
Connection Status
M1 (DC-HSDPA)
1
1
12
800
800
Connected
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Mobiles
Carrier
Simulation Rank
CQI
Best Bearer (kbps)
DL Obtained Throughput (kbps)
Connection Status
M1 (DC-HSDPA)
2
1
13
960
960+3.4
Connected
M2
2
2
15
1440
1440+3.4
Connected
M3
1
3
16
1600
1600+3.4
Connected
M4 (DC-HSDPA)
2
4
19
2400
1600+3.4
Connected
M4 (DC-HSDPA)
1
4
17
1920
960
Connected
M5
1
5
21
3040
480+3.4
Connected
M6
2
6
13
960
160+3.4
Connected
M7
1
7
14
1120
3.4
Delayed
M8
2
8
18
2080
3.4
Delayed
M9 (DC-HSDPA)
2
9
16
1600
0
Delayed
M9 (DC-HSDPA)
1
9
17
1920
3.4
Delayed
M10
1
10
14
1120
3.4
Delayed
M11
2
11
12
800
3.4
Delayed
M12 (DC-HSDPA)
1 2
12
14 15
1120 1440
0
Scheduler Saturation
M13
2
13
17
1920
0
Scheduler Saturation
M14 (DC-HSDPA)
1 2
14
13 15
960 1440
0
Scheduler Saturation
M15
1
15
17
1920
0
Scheduler Saturation
M16 (DC-HSDPA)
1 2
16
12 14
800 1120
0
Scheduler Saturation
The scheduled DC-HSDPA users have the following status: •
The first user (here M1) is connected to an HSDPA bearer in each cell. He obtains a total DL throughput of 1763.4 kbps (800+963.4). The user ranked 4th (here M4) is connected to an HSDPA bearer in each cell. He obtains a total DL throughput of 2563.4 kbps (1603.4+960). The user ranked 9th (here M9) is delayed in the two cells. He obtains a total DL throughput of 3.4 kbps.
• •
Proportional Fair 7 users from each cell (where 7 corresponds to the maximum number of HSDPA bearer users defined for each cell), i.e., a total of 14 users enter the scheduler in the same order as in the simulation. Then, they are sorted in an ascending order according to a new random parameter which corresponds to a combination of the user rank in the simulation and the channel quality indicator (CQI). For a user i, the random parameter RPi is calculated as follows: Simu
RPi = 50 R i
CQI
+ 50 R i
Where, Simu
Ri
CQI
Ri
is the user rank in the simulation.
is the user rank according to the CQI.
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You can change the default weights by editing the atoll.ini file. For more information, see the Administrator Manual.
DL Best Bearer Obtained Connection Throughput (kbps) Status (kbps)
Mobiles
Carrier
Simulation Rank
M1 DC-HSDPA
2
4
19
2
300
2400
2400+3.4
Connected
M2
1
5
21
1
300
3040
3040+3.4
Connected
M1 DC-HSDPA
1
4
17
4
400
1920
1440
Connected
M3
1
3
16
6
450
1600
800+3.4
Connected
M4
2
2
15
8
500
1440
1120+3.4
Connected
M5
2
8
18
3
550
2080
800+3.4
Connected
M6 DC-HSDPA
2
1
13
11
600
960
480+3.4
Connected
M6 DC-HSDPA
1
1
12
13
700
800
0
Delayed
M7 DC-HSDPA
1
9
17
5
700
1920
3.4
Delayed
M8
1
7
14
9
800
1120
3.4
Delayed
M7 DC-HSDPA
2
9
16
7
800
1600
0
Delayed
M9
2
6
13
12
900
960
3.4
Delayed
M10
1
10
14
10
1000
1120
3.4
Delayed
M11
2
11
12
14
1250
800
3.4
Delayed
M12 (DC-HSDPA)
1 2
12
14 15
1120 1440
0
Scheduler Saturation
0
Scheduler Saturation
M13
2
13
17
1920
0
Scheduler Saturation
0
Scheduler Saturation
M14 (DC-HSDPA)
1 2
14
13 15
960 1440
0
Scheduler Saturation
0
Scheduler Saturation
M15
1
15
17
1920
0
Scheduler Saturation
0
Scheduler Saturation
M16 (DC-HSDPA)
1 2
16
12 14
800 1120
0
Scheduler Saturation
0
Scheduler Saturation
CQI
CQI Rank
RP
The scheduled DC-HSDPA users have the following status: • • •
The user ranked 4th (here M1) is connected to an HSDPA bearer in each cell. He obtains a total DL throughput of 3843.4 kbps (2403.4+1440). The first user (here M6) is connected to an HSDPA bearer in his anchor cell and delayed in the other cell. He obtains a total DL throughput of 483.4 kbps (483.4+0). The user ranked 9th (here M7) is delayed in the two cells. He obtains a total DL throughput of 3.4 kbps.
4.3.2.4 HSUPA Part of the Algorithm HSPA VBR and BE service users active in the UL as well as all HSPA CBR service users (i.e., active and inactive), unless they have been rejected during the R99 or HSDPA parts of the algorithm, are then evaluated by the HSUPA part of the algorithm. Atoll manages the maximum number of users within each cell. CBR service users have the highest priority and are processed first, in the order established during the generation of the user distribution. Then, Atoll considers VBR service users in the order established during the generation of the user distribution and lastly, it processes BE service users in the order established during the generation of the user distribution. Let us assume there are 12 HSPA users in the cell:
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• • •
3 CBR service users with any activity status. All of them have been connected to an HSDPA bearer. 2 packet VBR service users. They have been connected to an HSDPA bearer. 7 packet BE service users active on UL. The first two users have been connected to an HSDPA bearer, the last one has been rejected and the remaining four have been delayed in the HSDPA part.
Finally, the maximum number of HSUPA bearer users equals 10. In this case, Atoll will consider the first ten HSPA users only and will reject the last two users in order not to exceed the maximum number of HSUPA bearer users allowed in the cell (their connection status is "HSUPA scheduler saturation").
4.3.2.4.1
Evaluation by the HSDPA HSUPA part of the Connection Status algorithm
Mobiles
Service
Simulation Rank
M1
CBR
4
Connected
Yes
M2
CBR
7
Connected
Yes
M3
CBR
9
Connected
Yes
M4
VBR
3
Connected
Yes
M5
VBR
5
Connected
Yes
M6
BE
1
Connected
Yes
M7
BE
2
Connected
Yes
M8
BE
6
Delayed
Yes
M9
BE
8
Delayed
Yes
M10
BE
10
Delayed
Yes
M11
BE
11
Delayed
No
M12
BE
12
Rejected
No
Admission Control During admission control, Atoll selects a list of HSUPA bearers for each user. The selected HSUPA bearers have to be compatible with the user equipment and capabilities of each HSUPA cell of the active set. For CBR service users, the list is restricted to HSUPA bearers that provide a peak RLC throughput higher than the minimum throughput demand. For VBR service users, the list of compatible bearers is restricted to HSUPA bearers that provide a peak RLC throughput between the maximum and the minimum throughput demands. Let us focus on one HSPA-BE service user with category 3 user equipment and a 50km/h mobility. This user is connected to one cell only. The cell supports HSPA+ functionalities, i.e the cell supports QPSK and 16QAM modulations in the UL. HSUPA user equipment categories are provided in the HSUPA User Equipment Categories table. The capabilities of the category 3 user equipment are: • • • • • •
Maximum Number of E-DPDCH codes: 2 TTI 2 ms: No so it supports 10 ms TTI Minimum Spreading Factor: 4 Maximum Block Size for a 2ms TTI: no value Maximum Block Size for a 10ms TTI: 14484 bits Highest Modulation Supported: QPSK
Figure 4.9: HSUPA UE Categories Table HSUPA bearer characteristics are provided in the HSUPA Bearer table. An HSUPA bearer is described with following characteristics: •
Radio Bearer Index: The bearer index number.
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• • • • • •
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TTI Duration (ms): The TTI duration in ms. The TTI can be 2 or 10 ms. Transport Block Size (Bits): The transport block size in bits. Number of E-DPDCH Codes: The number of E-DPDCH channels used. Minimum Spreading Factor: The smallest spreading factor used. Modulation: the modulation used (QPSK or 16QAM) Peak RLC Throughput (bps): The RLC peak throughput represents the peak throughput without coding (redundancy, overhead, addressing, etc.).
HSUPA bearers can be classified into two categories: •
HSUPA bearers using QPSK modulation: They can be selected for users connected to HSPA and HSPA+ capable cells.
•
HSUPA bearers using 16QAM modulation (improvement introduced by the release 7 of the 3GPP UTRA specifications, referred to as HSPA+). These HSUPA bearers can be allocated to users connected to cells with HSPA+ capabilities only.
Atoll considers an HSUPA bearer as compatible with the category 3 user equipment if: • • • • •
The TTI duration used by the bearer is supported by the user equipment (10 ms). The transport block size does not exceed the maximum transport block size supported by the user equipment (14484 bits): The number of E-DPDCH channels required by the bearer does not exceed the maximum number of E-DPDCH channels that the terminal can use (2). The minimum spreading factor used by the bearer is not less than the smallest spreading factor supported by the terminal (4). The modulation required by the bearer is supported by the terminal.
The HSUPA bearers compatible with category 3 user equipment are framed in red:
Figure 4.10: HSUPA Radio Bearers Table Then, during admission control, Atoll checks that the lowest compatible bearer in terms of the required E-DPDCH Ec⁄Nt does not require a terminal power higher than the maximum terminal power allowed. Atoll uses the HSUPA Bearer Selection table. Among the compatible HSUPA bearers, Atoll chooses the one with the lowest required Ec/Nt threshold. Here, this is the index 1 HSUPA bearer; the required Ec/Nt threshold to obtain this bearer is -21.7dB. Ec req req Then, from the required Ec/Nt threshold, ------ , Atoll calculates the required terminal power, P term – HSUPA . Nt E – DPDCH Ec req req UL P term – HSUPA = ------ L T N tot Nt E – DPDCH With UL
tx
UL intra
N tot ic = 1 – F MUD term I tot
UL extra
ic + I tot
L path L Tx L term L body L indoor E Shadowing 8 - ( ) L T = ------------------------------------------------------------------------------------------------------------------G Tx G term
260
UL
tx
ic + I inter – carrier ic + N 0
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tx
UL
intra
term , F MUD , I tot
UL
extra
, I tot
UL
tx
, I inter – carrier and N 0 are defined in "Inputs" on page 215.
Figure 4.11: HSUPA Bearer Selection Table req
Atoll rejects the user if the terminal power required to obtain the lowest compatible HSUPA bearer ( P term – HSUPA ) exceeds the maximum terminal power (his connection status is "HSUPA Admission Rejection"). At the end of this step, the number of non-rejected HSUPA bearer users is n HSUPA . All of them will be connected to an HSUPA bearer at the end.
4.3.2.4.2
HSUPA Bearer Allocation Process The HSUPA bearer allocation process depends on the type of service requested by the user. As explained before, CBR service users have the highest priority and are processed first, in the order established during the generation of the user distribution. After the admission control on CBR service users, Atoll performs a noise rise scheduling, followed by a radio resource control. Then, it repeats the same steps on VBR service users first, and lastly on BE service users, in the order established during the generation of the user distribution. CBR Service Users Let us focus on the three CBR service users mentioned in the example of the previous paragraph "HSUPA Part of the Algorithm" on page 258. We assume that all of them have been admitted. Noise rise scheduling and radio resource control are carried out on each user in order to determine the best HSUPA bearer that the user can obtain. Several CBR service users can share the same HSUPA bearer. Then, Atoll calculates the HSUPA bearer consumption ( C in %) for each user and takes into account this parameter when it determines the resources consumed by the user (i.e., the terminal power used, the number of channel elements and the Iub backhaul throughput). In the bearer allocation process shown below, the 3 CBR service users are represented by Mj, with j = 1 to 3.
8.
In the HSUPA coverage prediction, L T is calculated as follows:
L path L Tx L term L body L indoor M Shadowing – Eb Nt UL -) L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term
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For the user, Mj, with j varying from 1 to 3: Determination of the best HSUPA bearer B(Mj)
Allocation of the minimum throughput demand to Mj Calculation of C(B(Mj))
Sufficient Iub backhaul throughput to support the HSUPA bearer?
No
Is there a lower HSUPA bearer available? Yes No
Yes
Enough channel elements available to support the HSUPA bearer?
Downgrading to lower HSUPA bearer
Mj is rejected Yes No
Is there a lower HSUPA bearer available? No
Yes
Mj is rejected
Pterm-HSUPA recalculation and interference update
No
Mj = M3? Yes
Resource allocation for packet (HSPA – Variable Bit Rate) service users
Figure 4.12: HSUPA Bearer Allocation Process for CBR Service Users VBR Service Users Let us focus on the two VBR service users mentioned in the example of the previous paragraph "HSUPA Part of the Algorithm" on page 258. We assume that all of them have been admitted. Noise rise scheduling and radio resource control are carried out on each user in order to determine the best HSUPA bearer that the user can obtain. In the bearer allocation process shown below, the 2 VBR service users are represented by Mj, with j = 1 to 2. For the user, Mj, with j varying from 1 to 2: Determination of the best HSUPA bearer
Sufficient Iub backhaul throughput to support the HSUPA bearer?
No
Is there a lower HSUPA bearer available? Yes No
Yes
Enough channel elements available to support the HSUPA bearer?
Downgrading to lower HSUPA bearer
Mj is rejected Yes No
Is there a lower HSUPA bearer available? No
Yes
Mj is rejected
Pterm-HSUPA recalculation and interference update
No
Mj = M2? Yes
Resource allocation for packet (HSPA – Best Effort) service users
Figure 4.13: HSUPA Bearer Allocation Process for VBR Service Users BE Service Users Let us focus on the five BE service users mentioned in the example of the previous paragraph "HSUPA Part of the Algorithm" on page 258. We assume that all of them have been admitted. Noise rise scheduling and radio resource control are carried out on each user in order to determine the best HSUPA bearer that the user can obtain. In the bearer allocation process shown below, the 5 BE service users are represented by Mj, with j = 1 to 5.
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For the user, Mj, with j varying from 1 to 5: Determination of the best HSUPA bearer
Sufficient Iub backhaul throughput to support the HSUPA bearer?
No
Is there a lower HSUPA bearer available? Yes No
Yes
Downgrading to lower HSUPA bearer
Mj is rejected
Enough channel elements available to support the HSUPA bearer?
Yes No
Is there a lower HSUPA bearer available? No
Yes
Mj is rejected
Pterm-HSUPA recalculation and interference update
No
Mj = M5?
Figure 4.14: HSUPA Bearer Allocation Process for BE Service Users
4.3.2.4.3
Noise Rise Scheduling Determination of the Obtained HSUPA Bearer The obtained HSUPA radio bearer is the bearer that the user obtains after noise rise scheduling and radio resource control. CBR service users have the highest priority and are processed first. Therefore, after the admission control, the noise rise scheduling algorithm attempts to evenly share the remaining cell load between the CBR service users admitted in admission control; in terms of HSUPA, each user is allocated a right to produce interference. The remaining cell load factor on uplink UL
( X HSPA – CBR txi ic ) depends on the maximum load factor allowed on uplink and how much uplink load is produced by the served R99 traffic. It can be expressed as follows: UL
UL
UL
X HSPA – CBR txi ic = X max txi ic – X R99 txi ic Then, Atoll evenly shares the remaining cell load factor between the CBR service users admitted during the previous step ( n HSPA – CBR ). UL
X HSPA – CBR txi ic UL X user txi ic = -----------------------------------------------n HSPA – CBR Ec max From this value, Atoll calculates the maximum E-DPDCH Ec⁄Nt allowed ( ------ ) for each CBR service user. For further Nt E – DPDCH information on the calculation, see "Uplink Load Factor Due to One User" on page 281. Ec- max 1 ----- for the Without useful signal option Nt E – DPDCH = ------------------------------------------UL txi ic F ---------------------------------- – 1 UL X user txi ic UL
X user Ec- max ----for the Total noise option = -------------- Nt E – DPDCH UL F Then, it selects an HSUPA bearer. The allocation depends on the maximum E-DPDCH Ec⁄Nt allowed and on UE and cell capabilities. Atoll selects the best HSUPA bearer from the HSUPA compatible bearers. This is the HSUPA bearer ( Index HSUPABearer ) UL
TP P – R LC Index HSUPABearer with the highest potential throughput ( ----------------------------------------------------------------- ) where: N Rtx Index HSUPABearer •
Ec- req Ec max ---- ------ Nt E – DPDCH Nt E – DPDCH
•
And P term – HSUPA P term
req
max
req
Ec When several HSUPA bearers are available, Atoll selects the one with the lowest ------ . Nt E – DPDCH
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After the noise rise scheduling, Atoll carries out radio resource control, verifying if enough channel elements and Iub backhaul throughput are available for the HSUPA bearer assigned to the user. For information on radio resource control, see "Radio Resource Control" on page 267. After processing all CBR service users, Atoll carries out noise rise scheduling and radio resource control on VBR service users. During the noise rise scheduling, Atoll distributes the remaining cell load factor available after all CBR service users have been served. It can be expressed as follows: UL
UL
UL
UL
X HSPA – VBR txi ic = X max txi ic – X R99 txi ic – X HSPA – CBR txi ic The remaining cell load factor is shared equally between the admitted VBR service users ( n HSPA – VBR ). UL
X HSPA – VBR txi ic UL X user txi ic = -----------------------------------------------n HSPA – VBR Ec max From this value, Atoll calculates the maximum E-DPDCH Ec⁄Nt allowed ( ------ ) as explained above and selects an Nt E – DPDCH HSUPA bearer for each VBR service user. After the noise rise scheduling, Atoll carries out radio resource control on VBR service users. For information on radio resource control, see "Radio Resource Control" on page 267. After processing VBR service users, Atoll carries out noise rise scheduling and radio resource control on BE service users. During the noise rise scheduling, Atoll distributes the remaining cell load factor available after all CBR and VBR service users have been served. It can be expressed as follows: UL
UL
UL
UL
UL
X HSPA txi ic = X max txi ic – X R99 txi ic – X HSPA – CBR txi ic – X HSPA – VBR txi ic The remaining cell load factor is shared equally between the admitted BE service users ( n HSPA ). UL
X HSPA txi ic UL X user txi ic = -----------------------------------n HSPA Ec max From this value, Atoll calculates the maximum E-DPDCH Ec⁄Nt allowed ( ------ ) as explained above and selects an Nt E – DPDCH HSUPA bearer for each BE service user. After the noise rise scheduling, Atoll carries out radio resource control on BE service users. For information on radio resource control, see "Radio Resource Control" on page 267. Example: We have a cell with six BE service users, and neither CBR user nor VBR user. All BE service users have been admitted. The remaining cell load factor equal to 0.6 is shared between the BE service users. Therefore, the UL load factor allotted to each user is 0.1. Let’s take the cell UL reuse factor equal to 1.5. Atoll calculates the maximum E-DPDCH Ec⁄Nt allowed (the Without useful signal option is selected). Ec max We have: ------ = -11.5 dB Nt E – DPDCH Here, the obtained HSUPA bearer is the index 5 HSUPA bearer. It provides a potential throughput of 128 kbps and requires E-DPDCH Ec⁄Nt of -13 dB (lower than -11.5 dB) and a terminal power lower than the maximum terminal power allowed. .
HSUPA Bearers Index
Required Ec/Nt Threshold (dB)
Nb of Retransmissions
Peak RLC Throughput (kbps)
Potential Throughput (kbps)
1
-21.7
2
32
16
2
-19
2
64
32
3
-16.1
2
128
64
4
-13.9
2
192
96
5
-13
2
256
128
6
-10.1
2
512
256
7
-8
2
768
384
8
-7
2
1024
512
AtollAtollNoise Rise Scheduling in Soft Handover With HSUPA, uplink soft handover impacts the scheduling operation. While HSDPA sends data from one cell only, with HSUPA all cells in the active set receive the transmission from the terminal. Therefore, all the cells are impacted by the transmission in terms of noise rise.
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For each HSPA-capable cell of the active set tx k ic , Atoll calculates the maximum E-DPDCH Ec⁄Nt allowed max
Ec tx ic ) as explained in "HSUPA Bearer Allocation Process" on page 261. ( ------ Nt E – DPDCH k For each cell of the active set tx k ic , Atoll calculates the maximum terminal power allowed to obtain an HSUPA radio bearer max
( P term – HSUPA tx k ic ). max
Ec max UL max P term – HSUPA tx k ic = min ------ tx ic L T N tot P term Nt E – DPDCH k With UL
UL
tx
intra
N tot ic = 1 – F MUD term I tot
UL extra
ic + I tot
tx
UL
ic + I inter – carrier ic + N 0
L path L Tx L term L body L indoor E Shadowing 9 - ( ) L T = ------------------------------------------------------------------------------------------------------------------G Tx G term tx
UL intra
term , F MUD , I tot
UL extra
, I tot
UL
tx
, I inter – carrier and N 0 are defined in "Inputs" on page 215.
As HSUPA bearer users in soft handover use the lowest granted noise rise, Atoll chooses the lowest of maximum terminal power allowed for each cell of the active set tx k ic . max
P term – HSUPA = min
tx AS k
max
P term – HSUPA tx k ic max
Once Atoll knows the selected maximum terminal power ( P term – HSUPA ), it recalculates the maximum E-DPDCH Ec⁄Nt allowed Ec max ( ------ tx ic ) for each HSUPA-capable cell of the active set. Nt E – DPDCH k max
P term – HSUPA Ec- max ---- Nt E – DPDCH tx k ic = ----------------------------UL L T N tot max
Ec Then, Atoll calculates the maximum E-DPDCH Ec⁄Nt allowed ( ------ ) after signal recombination of all HSUPA capable Nt E – DPDCH cells of the active set 10. For softer (1/2) and softer-softer (1/3) handovers, we have: max
Ec- UL ----= f rake efficiency Nt E – DPDCH
max
Ec- ---- tx ic Nt E – DPDCH k
txk ActiveSet samesite
Ec max = For soft (2/2) and soft-soft (3/3) handovers, we have: ------ Nt E – DPDCH
Ec- max Max ---- tx ic Nt E – DPDCH k
txk ActiveSet
For softer-soft handover (2/3), it depends on if the MRC option is selected (option available in Global parameters). If selected, we have:
9.
In the HSUPA coverage prediction, L T is calculated as follows:
L path L Tx L term L body L indoor M Shadowing – Eb Nt UL -) L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term
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max
Ec- ---- Nt E – DPDCH =
©Forsk 2015
UL Ec- max Ec- max -------- tx k ic tx l ic tx ,tx ActiveSet f rake efficiency Nt Nt k l E – DPDCH E – DPDCH tx samesite tx k k Max
tx othersite l
max
Ec Else, we have: ------ = Nt E – DPDCH
Ec- max Max ---- tx ic Nt E – DPDCH k
txk ActiveSet
Then, Atoll selects an HSUPA bearer as previously explained in "HSUPA Bearer Allocation Process" on page 261. The allocation depends on the maximum E-DPDCH Ec⁄Nt allowed and on UE and cell capabilities. Atoll selects the best HSUPA bearer from the HSUPA compatible bearers. This is the HSUPA bearer ( Index HSUPABearer ) with the highest potential throughput UL
TP P – R LC Index HSUPABearer ( ----------------------------------------------------------------- ) where: N Rtx Index HSUPABearer Ec- req Ec- max ---- ---- Nt E – DPDCH Nt E – DPDCH
•
Ec req When several HSUPA bearers are available, Atoll selects the one with the lowest ------ . Nt E – DPDCH
10.
In HSUPA coverage predictions, we have the following:
Ec max UL For softer (1/2) and softer-softer (1/3) handovers: ------ = f rake efficiency Nt E – DPDCH
max
Ec- ---- Nt E – DPDCH tx k ic
txk ActiveSet samesite
Ec max For soft handover (2/2): ------ = Nt E – DPDCH
Ec- max UL Max ---- tx ic G macro – diversity 2links Nt E – DPDCH k
txk ActiveSet
Ec max For soft-soft handover (3/3): ------ = Nt E – DPDCH
tx k
Ec- max UL Max ---- tx ic G macro – diversity 3links Nt E – DPDCH k ActiveSet
For softer-soft handover (2/3), it depends on if the MRC option is selected (option available in Global parameters). If selected, we have:
max
Ec- ----= Nt E – DPDCH
UL Ec- max Ec- max --------f tx ic tx ic txk ,txl ActiveSet rake efficiency Nt E – DPDCH l Nt E – DPDCH k tx k samesite tx k Max
tx othersite l
UL
G macro – diversity 2links
max
Ec Else, we have: ------ = Nt E – DPDCH
266
Ec- max UL Max ---- Nt E – DPDCH tx k ic G macro – diversity 2links
txk ActiveSet
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Determination of the Requested HSUPA Bearer The requested HSUPA radio bearer is selected from the HSUPA bearers compatible with the user equipment. Atoll determines the HSUPA bearer the user would obtain by considering the entire remaining load of the cell. The user is treated as if he is the only user in the cell. Therefore, if we go on with the previous example, the maximum E-DPDCH Ec⁄Nt allowed is equal to -1.8 dB and the requested HSUPA bearer is the index 7 HSUPA bearer. It requires E-DPDCH Ec⁄Nt of -8 dB (lower than -1.8 dB) and a terminal power lower than the maximum terminal power allowed.
4.3.2.4.4
Radio Resource Control Atoll checks to see if enough channel elements are available and if the Iub backhaul throughput is sufficient for the HSUPA bearer assigned to the user (taking into account the maximum number of channel elements defined for the site and the maximum Iub backhaul throughput allowed on the site in the uplink). If not, Atoll allocates a lower HSUPA bearer ("downgrading") which needs fewer channel elements and consumes lower Iub backhaul throughput. If no channel elements are available, the user is rejected. On the same hand, if the maximum Iub backhaul throughput allowed on the site in the uplink is still exceeded even by using the lowest HSDPA bearer, the user is rejected.
4.3.2.5 Convergence Criteria The convergence criteria are evaluated for each iteration, and can be written as follow: DL
DL DL max max P tx ic k – P tx ic k – 1 N user ic k – N user ic k – 1 Stations Stations - 100 = max int ----------------------------------------------------------------------------------- 100 int --------------------------------------------------------------------------------------------DL P tx ic k N user ic k
UL UL UL UL max max I tot ic k – I tot ic k – 1 N user ic k – N user ic k – 1 Stations Stations - 100 int --------------------------------------------------------------------------------------------- 100 UL = max int ----------------------------------------------------------------------------------UL UL I tot ic k N user ic k
Atoll stops the algorithm if: 1st case: Between two successive iterations, UL and DL are lower than their respective thresholds (defined when creating a simulation). The simulation has reached convergence. Example: Let us assume that the maximum number of iterations is 100, UL and DL convergence thresholds are set to 5. If UL 5 and DL 5 between the 4th and the 5th iteration, Atoll stops the algorithm after the 5th iteration. Convergence has been reached. 2nd case: After 30 iterations, UL and/or DL are still higher than their respective thresholds and from the 30th iteration, UL and/or DL do not decrease during the next 15 successive iterations. The simulation has not reached convergence (specific divergence symbol). Examples: Let us assume that the maximum number of iterations is 100, UL and DL convergence thresholds are set to 5. 1. After the 30th iteration, UL and/or DL equal 100 and do not decrease during the next 15 successive iterations: Atoll stops the algorithm at the 46th iteration. Convergence has not been reached. 2. After the 30th iteration, UL and/or DL equal 80, they start decreasing slowly until the 40th iteration (without going under the thresholds) and then, do not change during 15 successive iterations: Atoll stops the algorithm at the 56th iteration without reaching convergence. 3rd case: After the last iteration. If UL and/or DL are still strictly higher than their respective thresholds, the simulation has not reached convergence (specific divergence symbol). If UL and DL are lower than their respective thresholds, the simulation has reached convergence.
4.3.3 Results 4.3.3.1 R99 Related Results This table contains some R99 specific simulation results provided in the Cells and Mobiles tabs of the simulation property dialogue.
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Name
Value
Unit
Description
Nb E1 T1 Ethernet
E1 T1 Ethernet TPIub – DL N I TP RoundUp Max E1 T1 Ethernet TP Iub – UL N I TP
None
Number of E1/T1/Ethernet links required by the site
None
Downlink intra-cell interference at terminal on carrier ic
W
Downlink extra-cell interference at terminal on carrier ic
W
Downlink inter-carrier interference at terminal on carrier ic
DL I intra txi
DL SCH txi ic P txi ic – P DL ----------------------------P tot txi ic – F ortho BTS tot LT txi
ic
DL
– 1 – F ortho BTS P b txi ic
DL
I extra ic
DL
P tot txj ic
txj j i
Ptot txj icadj DL
DL
I inter – carrier ic
txj j ---------------------------------------------
RF ic ic adj
DL I inter – techno log y ic
ni
DL
DL
I tot ic
DL
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP n ic
DL
DL
DL
DL
Term
I tot ic + N 0
Pb
UL
I tot
txi ic
ic
term
W
Total effective interference at terminal on carrier ic (after unscrambling)
W
Total received noise at terminal on carrier ic
W
Total power received at transmitter from intra-cell terminals using carrier ic
W
Total power received at transmitter from extra-cell terminals using carrier ic
W
Uplink inter-carrier interference at terminal on carrier ic
txi
UL extra
I tot
txi ic
UL
P b ic
term txj j i
Pb
UL
UL I inter – carrier txi
UL
I tot txi ic
UL N tot txi
ic
ic
ic adj
term txj j ----------------------------------RF ic ic adj UL extra
I tot
UL intra
Tx
txi ic + 1 – F MUD term I tot UL I tot txi
ic +
Downlink inter-technology interference at terminal on carrier ic a
i
I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic
N tot ic UL intra
W
UL txi ic +I inter – carrier txi icW
tx N0
Total received interference at transmitter on carrier ic
W
Total noise at transmitter on carrier ic (Uplink interference)
None
Cell uplink load factor on carrier ic
UL
UL
I tot txi ic ---------------------------UL N tot txi ic
UL
I tot txi ic --------------------------------------------------------------------------------------UL intra Tx I tot txi ic 1 – F MUD term
UL
1 --------------------------UL F txi ic
X txi ic
UL
F txi ic
E txi ic
268
None Cell uplink reuse factor on carrier ic
None
Cell uplink reuse efficiency factor on carrier ic
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Name
Value
Unit
Description
None
Downlink load factor on carrier ic
Simulation result available per cell DL I extra ic
tch
DL
+ I inter – carrier ic L T --------------------------------------------------------------------------------- + 1 – F ortho BTS DL P Tx txi ic --------------------------------------------------------------------------------------------------------------------------------1 - + 1 – F --------- ortho
DL
CI req
DL
X txi ic
BTS
DL
Q req DL with CI req = --------DL Gp Simulation result available per mobile DL
I tot ic -----------------DL N tot ic DL
I tot ic ----------------------------DL I intra txi ic
DL
F txi ic DL
– 10 log 1 – X txi ic
UL
– 10 log 1 – X txi ic
NR txi ic NR txi ic a.
None Downlink reuse factor on a carrier ic
DL
dB
Noise rise on downlink
UL
dB
Noise rise on uplink
In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the fractional load.
4.3.3.2 HSPA Related Results At the end of the R99 part, the users can be: • •
Either connected and in this case, they obtain the requested R99 bearer, Or rejected exactly for the same reasons as R99 users.
Only connected HSDPA and HSPA users are considered in the HSDPA part. At the end of the HSDPA part, BE service users can be: • • •
Either connected if they obtain an HSDPA bearer, Or rejected if the maximum number of HSDPA bearer users per cell is exceeded, Or delayed in case of lack of resources (HSDPA power, HS-SCCH power, HS-SCCH channels, OVSF codes).
VBR service users can be: • •
Either connected if they obtain an HSDPA bearer, Or rejected for the following reasons: the maximum number of HSDPA bearer users per cell is exceeded, the lowest HSDPA bearer the user can obtain does not provide a peak RLC throughput higher than the minimum throughput demand, the HS-SCCH signal quality is not sufficient, there are no more OVSF codes available, the maximum Iub backhaul throughput allowed on the site in the downlink is exceeded.
CBR service users can be: • •
Either connected if they obtain an HSDPA bearer, Or rejected for the following reasons: the maximum number of HSDPA bearer users per cell is exceeded, the lowest HSDPA bearer the user can obtain does not provide a peak RLC throughput higher than the minimum throughput demand, the HS-SCCH signal quality is not sufficient, there are no more OVSF codes available, the maximum Iub backhaul throughput allowed on the site in the downlink is exceeded.
In the HSUPA part, Atoll processes HSPA service users who are connected to an HSDPA bearer or were delayed in the previous step. At the end, they can be: • •
4.3.3.2.1
Either connected if they obtain an HSUPA bearer, Or rejected for the following reasons: the maximum number of HSUPA bearer users per cell is exceeded, the terminal power required to obtain the lowest compatible HSUPA bearer exceeds the maximum terminal power, there are no more channel elements available, the maximum Iub backhaul throughput allowed on the site in the uplink is exceeded, the lowest compatible HSUPA bearer they can obtain does not provide a peak RLC throughput higher than the minimum throughput demand (only for CBR and VBR service users).
Statistics Tab In the Statistics tab, Atoll displays as results: •
The number of rejected users.
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The number of delayed users. The number of R99 bearer users connected to a cell (result of the R99 part). This figure includes R99 users as well as HSDPA and HSPA users since all of them request an R99 bearer. • •
The number of R99 bearer users per frequency band. The number of R99 bearer users per activity status.
•
The downlink and uplink peak throughputs ( TP P – D L and TP P – U L ) generated by their connection to R99 bearers.
R99
R99
Only active users are considered.
R99
TP P –D L =
R99
R99
TP P – DL R99 Bearer and TP P – U L =
Active users
R99
TP P – UL R99 Bearer
Active users
R99
R99
TP P – DL R99 Bearer is the downlink peak throughput of the user R99 radio bearer and TP P – UL R99 Bearer is the uplink peak throughput of the user R99 radio bearer. •
The number of connected users with an HSDPA bearer (result of the HSDPA part) and the downlink peak RLC throughput they generate. HSDPA and HSPA service users are considered since they all request an HSDPA bearer. On DL
the other hand, only active users are taken into consideration in the downlink throughput calculation ( TP HSDPA ).
DL
TP HSDPA =
DL
TP P – RLC
Active users DL
TP P – RLC is the peak RLC throughput provided in the downlink. •
The number of connected users with an HSUPA bearer (result of the HSUPA part). Only HSPA service users are considered. In addition, Atoll indicates the uplink peak RLC throughput generated by active users connected with an HSUPA bearer UL
( TP HSUPA ): UL
TP HSUPA =
UL
TP P – RLC
Active users UL
TP P – RLC is the peak RLC throughput provided in the uplink.
4.3.3.2.2Mobiles Tab In the Mobiles tab, Atoll indicates for each user: •
UL
DL
The uplink and downlink total requested throughputs in kbps (respectively, TP requested M b and TP requested M b )
For R99 users, the DL and UL total requested throughputs correspond to the DL and UL peak throughputs of the R99 bearer associated to the service. DL
R99
UL
R99
TP requested M b = TP P – DL R99 Bearer TP requested M b = TP P – UL R99 Bearer For HSDPA users, the uplink requested throughput corresponds to the peak throughput of ADPCH R99 radio bearer and the downlink requested throughput is the sum of the ADPCH radio bearer peak throughput and the peak RLC throughput(s) that the selected HSDPA radio bearer(s) can provide. Here, the user is treated as if he is the only user in the cell and then, Atoll determines the HSDPA bearer the user would obtain by considering the entire HSDPA power available of the cell. DL
R99
DL
R99
DL
TP requested M b = TP P – DL ADPCH R99 Bearer + TP P – RLC for single-carrier users TP requested M b = TP P – DL ADPCH R99 Bearer AnchorCell +
DL
TP P – RLC c for dual-carrier users
c Serving Cells UL
R99
TP requested M b = TP P – UL ADPCH R99 Bearer For HSPA users, the uplink requested throughput is equal to the sum of the ADPCH-EDPCCH radio bearer peak throughput and the peak RLC throughput of the requested HSUPA radio bearer. The requested HSUPA radio bearer is selected from the HSUPA
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bearers compatible with the user equipment. Here, the user is treated as if he is the only user in the cell and then, Atoll determines the HSUPA bearer the user would obtain by considering the entire remaining load of the cell. The downlink requested throughput is the sum of the ADPCH-EDPCCH radio bearer peak throughput and the peak RLC throughput(s) that the requested HSDPA radio bearer(s) can provide. The requested HSDPA radio bearer is determined as explained in the previous paragraph. DL
R99
DL
R99
DL
TP requested M b = TP P – DL ADPCH – EDPCCH R99 Bearer + TP P – RLC for single-carrier users TP requested M b = TP P – DL ADPCH – EDPCCH R99 Bearer AnchorCell +
DL
TP P – RLC c for dual-carrier users
c Serving cells UL
R99
UL
TP requested M b = TP P – UL ADPCH – EDPCCH R99 Bearer + TP P – RLC •
UL
DL
The uplink and downlink total obtained throughputs in kbps (respectively, TP obtained M b and TP obtained M b )
For R99 service users, the obtained throughput is the same as the requested throughput if he is connected without being downgraded. Otherwise, the obtained throughput is lower (it corresponds to the peak throughput of the selected R99 bearer). If the user is rejected, the obtained throughput is zero. In the downlink, HSDPA bearer users can be connected to a single cell or to two adjacent cells of the same transmitter when the user has a DC-HSDPA-capable terminal and when the transmitter supports the multi-cell HSDPA mode. For a single-carrier HSDPA service user connected to an HSDPA bearer, the downlink obtained throughput corresponds to the instantaneous throughput; this is the sum of the A-DPCH radio bearer peak throughput and the peak RLC throughput provided by the selected HSDPA radio bearer after scheduling and radio resource control. If the user is delayed (he is only connected to an R99 radio bearer), downlink obtained throughput corresponds to the downlink peak throughput of the ADPCH radio bearer. Finally, if the user is rejected either in the R99 part or in the HSDPA part (i.e., because the HSDPA scheduler is saturated), the downlink obtained throughput is zero. For a dual-carrier HSDPA service user connected to two HSDPA bearers, the downlink obtained throughput corresponds to the instantaneous throughput; this is the sum of the peak throughput provided by the A-DPCH radio bearer in the anchor cell and the peak RLC throughputs provided by the selected HSDPA radio bearers after scheduling and radio resource control. If the user is connected to one cell and delayed in the other cell, the downlink obtained throughput is the sum of the peak throughput provided by the A-DPCH radio bearer in the anchor cell and the peak RLC throughput provided by the selected HSDPA radio bearer after scheduling and radio resource control. If the user is delayed in the two cells (he is only connected to an R99 radio bearer in the anchor cell), the downlink obtained throughput corresponds to the downlink peak throughput of the ADPCH radio bearer in the anchor cell. Finally, if the user is rejected either in the R99 part or in the HSDPA part (i.e., because the HSDPA scheduler is saturated), the downlink obtained throughput is zero. In the uplink, HSDPA service users can only have a single-carrier connection. When the user is either connected or delayed, the uplink obtained throughput corresponds to the uplink peak throughput of the ADPCH radio bearer. If the user is rejected either in the R99 part or in the HSDPA part (i.e., because the HSDPA scheduler is saturated), the uplink obtained throughput is zero. For single-carrier HSPA VBR and BE service users, on downlink, if the user is connected to an HSDPA bearer, the downlink obtained throughput corresponds to the instantaneous throughput. The instantaneous throughput is the sum of the ADPCHEDPCCH radio bearer peak throughput and the peak RLC throughput provided by the selected HSDPA radio bearer after scheduling and radio resource control. If the user is delayed, the downlink obtained throughput corresponds to the downlink peak throughput of ADPCH-EDPCCH radio bearer. If the user is rejected, the downlink obtained throughput is "0". For dual-carrier HSPA VBR and BE service users connected to two HSDPA bearers, the downlink obtained throughput corresponds to the instantaneous throughput; this is the sum of the peak throughput provided by the ADPCH-EDPCCH radio bearer in the anchor cell and the peak RLC throughputs provided by the selected HSDPA radio bearers after scheduling and radio resource control. If the user is connected to one cell and delayed in the other cell, the downlink obtained throughput is the sum of the peak throughput provided by the ADPCH-EDPCCH radio bearer in the anchor cell and the peak RLC throughput provided by the selected HSDPA radio bearer after scheduling and radio resource control. If the user is delayed in the two cells (he is only connected to an R99 radio bearer in the anchor cell), the downlink obtained throughput corresponds to the downlink peak throughput of the ADPCH-EDPCCH radio bearer in the anchor cell. Finally, if the user is rejected, the downlink obtained throughput is zero. In uplink, HSPA VBR and BE service users can only have a single-carrier connection. When the user is connected to an HSUPA bearer, the uplink obtained throughput is the sum of the ADPCH-EDPCCH radio bearer peak throughput and the peak RLC throughput provided by the selected HSUPA radio bearer after noise rise scheduling. If the user is rejected, the uplink obtained throughput is zero. For a connected HSPA CBR service user, the uplink and downlink total obtained throughputs are the sum of the ADPCHEDPCCH radio bearer peak throughput and the minimum throughput demand defined for the service. If the user is rejected, the uplink and downlink total obtained throughputs are "0". •
The mobile total power ( P term )
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UL
P term = P term – R99 f act –EDPCCH + P term – HSUPA for HSPA VBR and BE service users. UL
P term = P term – R99 f act –EDPCCH + P term – HSUPA C HSDPABearer for HSPA CBR service users. UL
For HSPA CBR service users, f act –EDPCCH = 0.1 .
And P term = P term – R99 for R99 and HSDPA users. •
DL
The HSDPA application throughput in kbps ( TP A M b )
This is the net HSDPA throughput without coding (redundancy, overhead, addressing, etc.).
DL
TP P – RLC c 1 – BLER HSDPA
DL c Serving cells TP A M b = ------------------------------------------------------------------------------------------------------- f TP – Scaling – TP Offset TTI
Where: DL
TP P – RLC is the peak RLC throughput provided to the user by the selected HSDPA radio bearer after scheduling and radio resource control. BLER HSDPA is read in the quality graph defined for the triplet “reception equipment-selected bearer-mobility” (HSDPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of the measured quality (HS-PDSCH Ec/Nt). Knowing the HS-PDSCH Ec/Nt, Atoll calculates the corresponding BLER. TP Offset and f TP – Scaling represent the scaling factor between the application throughput and the RLC (Radio Link Control) throughput and the throughput offset respectively. These two parameters model the header information and other supplementary data that does not appear at the application level. They are defined in the service properties. TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user equipment category properties. •
The number of OVSF codes
This is the number of 512-bit length OVSF codes consumed by the user. •
The required HSDPA power in dBm ( P HSDPA required )
It corresponds to the HSDPA power required to provide the HSDPA bearer user with the downlink requested throughput. The downlink requested throughput is the throughput the user would obtain if he was the only user in the cell. In this case, Atoll determines the HSDPA bearer the user would obtain by considering the entire HSDPA power available of the cell. P HSDPA required = P HS – PDSCH used + n HS – SCCH P HS – SCCH P HS – PDSCH used is the HS-PDSCH power required to obtain the selected HSDPA bearer (in dBm). If the HSDPA bearer allocated to the user is the best one, P HS – PDSCH used corresponds to the available HS-PDSCH power of the cell. On the other hand, if the HSDPA bearer has been downgraded in order to be compliant with cell and UE capabilities or for another reason, P HS – PDSCH used will be lower than the available HS-PDSCH power of the cell. •
The served HSDPA power in dBm ( P HSDPA served )
This is the HSDPA power required to provide the HSDPA bearer user with the downlink obtained throughput. The downlink obtained rate is the throughput experienced by the user after scheduling and radio resource control. P HSDPA served = P HS – PDSCH used + n HS – SCCH P HS – SCCH for HSDPA users, HSPA BE and VBR service users. And P HSDPA served = P HS – PDSCH used C HSDPABearer for HSPA CBR service users Where P HS – PDSCH used is the HS-PDSCH power required to obtain the selected HSDPA bearer. •
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The maximum number of retransmissions in order to have the requested HSUPA radio bearer with a given BLER. •
The No. of HSUPA Retransmissions (Obtained)
The maximum number of retransmissions in order to have the obtained HSUPA radio bearer with a given BLER. •
UL
The HSUPA application throughput in kbps ( TP A M b )
This is the net HSUPA throughput without coding (redundancy, overhead, addressing, etc.). UL
TP P – RLC M b 1 – BLER HSUPA f TP – Scaling – TP Offset UL TP A M b = ---------------------------------------------------------------------------------------------------------------------------------------N Rtx Where: UL
TP P – RLC is the peak RLC throughput provided by the selected HSUPA radio bearer after noise rise scheduling. BLER HSUPA is the residual BLER after N Rtx retransmissions. It is read in the quality graph defined for the quartet “reception equipment-selected bearer-number of retransmissions-mobility” (HSUPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of the measured quality (E-DPDCH Ec/Nt). Knowing the EDPDCH Ec/Nt, Atoll calculates the corresponding BLER. TP Offset and f TP – Scaling respectively represent the scaling factor between the application throughput and the RLC (Radio Link Control) throughput and the throughput offset. These two parameters model the header information and other supplementary data that does not appear at the application level. They are defined in the service properties. N Rtx is the maximum number of retransmissions for the obtained HSUPA bearer. This figure is read in the HSUPA Bearer Selection table. The following columns appear if, when creating the simulation, you select "Detailed information about mobiles": •
The uplink and downlink requested peak RLC throughputs (kbps)
Downlink and uplink requested peak RLC throughputs are not calculated for R99 users. For HSDPA users, the uplink peak RLC throughput is not calculated and the downlink requested peak RLC throughput is the throughput that the selected HSDPA radio bearer(s) can provide. Here, the user is treated as if he is the only user in the cell and then, Atoll determines the HSDPA bearer he would obtain by considering the entire HSDPA power available of the cell. For HSPA users, the requested uplink peak RLC throughput is the throughput of the requested HSUPA radio bearer. The requested HSUPA radio bearer is selected from the HSUPA bearers compatible with the user equipment. Here, the user is treated as if he is the only user in the cell and then, Atoll determines the HSUPA bearer the user would obtain by considering the entire remaining load of the cell. If the user is connected to one or two HSDPA bearers in the downlink, the downlink requested peak RLC throughput is the throughput that the requested HSDPA radio bearer(s) can provide. The requested HSDPA radio bearer is determined as explained in the previous paragraph. •
The uplink and downlink obtained peak RLC throughput (kbps)
Downlink and uplink obtained peak RLC throughputs are not calculated for R99 users. For HSDPA users connected to one or two HSDPA bearers, the uplink obtained peak RLC throughput is not calculated, and the downlink obtained peak RLC throughput is the throughput provided by the selected HSDPA radio bearer(s) after scheduling and radio resource control. For connected HSPA BE and VBR service users, on uplink, if the user is connected to an HSUPA bearer, the obtained uplink peak RLC throughput is the throughput provided by the selected HSUPA radio bearer after noise rise scheduling. On downlink, if the user is connected to one or two HSDPA bearers, the downlink obtained peak RLC throughput is the throughput provided by the selected HSDPA radio bearer(s) after scheduling and radio resource control. For a connected HSPA CBR service user, the uplink and downlink obtained peak RLC throughputs are the uplink and downlink minimum throughput demands defined for the service.
4.3.3.2.3
Cells Tab In the Cells tab, Atoll gives: •
The available HSDPA power in the cell, c, in dBm ( P HSDPA c ):
This is: • •
Either a fixed value in case of a static HSDPA power allocation strategy, Or a simulation result when the option "HSDPA Power Dynamic Allocation" is selected. We have:
P HSDPA c = P max c – P Headroom c – P tx – R99 c – P HSUPA c
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P tx – R99 c = P pilot c + P SCH c + P OtherCCH c +
with
tch used for R99 users
•
P tch c +
DL
P tch c f act –ADPCH
tch used for HSPA users
The transmitted HSDPA power in the cell, c, in dBm ( P tx –H SDPA c ):
It corresponds to the HSDPA power used to serve HSDPA bearer users.
P tx –H SDPA c =
P HSDPA M b served
Mb c
•
The number of HSDPA users in the cell
They are the connected and delayed HSDPA bearer users. HSDPA and HSPA users are considered since they all request an HSDPA bearer. DC-HSDPA users are accounted for once in each serving cell. •
The number of simultaneous HSDPA users in the cell ( n M ) b
It corresponds to the number of connected HSDPA bearer users that the cell supports at a time, i.e. within one transmission time interval. All these users are connected to the cell at the end of the HSDPA part of the simulation; they have a connection with the R99 bearer and an HSDPA bearer. DC-HSDPA users are accounted for once in each serving cell. •
DL
The instantaneous HSDPA throughput in the cell, c, in kbps ( TP Inst c )
This is the number of kilobits per second that the cell supports on downlink to provide simultaneous connected HSDPA bearer users with an HSDPA bearer. We will differentiate single-carrier users (Ms) from DC-HSDPA users (Md-HSDPA stands for HSDPA BE and VBR users, and Md-HSPA refers to HSPA BE and VBR service users). DL
R99
DL
TP requested M b = TP P – DL ADPCH R99 Bearer + TP P – RLC
DL
TP obtained M s +
Ms c
R99
DL
TP P – DL R99 Bearer + TP P – RLC M d – HSDPA
M d – HSDPA c c is the anchor cell
+
DL
TP P – RLC M d – HSDPA +
M c d – HSDPA c is the secondary cell
DL
TP Inst cell =
R99
DL
TP P – DL R99 Bearer + TP P – RLC M d – HSPA +
M d – HSPA c c is the anchor cell
DL
M d – HSPA c
TP P – RLC M d – HSPA
c is the secondary cell DL TP P – RLC
is the peak RLC throughput provided by the selected HSDPA radio bearer after scheduling and radio resource
control. R99
TP P – DL R99 Bearer is the peak throughput of the ADPCH radio bearer if the user is an HSDPA user. For HSPA users, it corresponds to the ADPCH-EDPCCH radio bearer. • DL
DL
The instantaneous HSDPA Effective MAC Throughput in the cell, c, in kbps ( TPE –M AC c )
TP E – M AC c =
Mb c
S block M b --------------------------------------T TTI TTI M b
Where, S block M b is the transport block size (in kbits) of the HSDPA bearer selected by the user; it is defined for each HSDPA bearer in the HSDPA Radio Bearers table. TTI M b is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user equipment category properties.
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T TTI is the TTI duration, i.e. 2 10 s (2000 TTI in one second). This value is specified by the 3GPP. •
DL
The average instantaneous HSDPA throughput in the cell, c, in kbps ( TP Av – Inst c ) DL
TP Inst c DL TP Av – Inst c = -------------------nM b
•
DL
The HSDPA application throughput in the cell, c, in kbps ( TP A c ) DL
Either TP A c =
DL
M c b
TP P – RLC M b 1 – BLER HSDPA f TP – Scaling – TP Offset -------------------------------------------------------------------------------------------------------------------------------------- if the scheduling algorithm is Round Robin or TTI
Proportional Fair, DL
TP P – RLC M b maxC I 1 – BLER HSDPA f TP – Scaling – TP Offset DL - if the scheduling algorithm is Max C/I. Or TPA c = -------------------------------------------------------------------------------------------------------------------------------------------------------------TTI M b maxC I is the user with the highest C I in the cell. DL
TP P – RLC is the peak RLC throughput provided by the selected HSDPA radio bearer after scheduling and radio resource control. BLER HSDPA is read in the quality graph defined for the triplet “reception equipment-selected bearer-mobility” (HSDPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of the measured quality (HS-PDSCH Ec/Nt). Knowing the HS-PDSCH Ec/Nt, Atoll calculates the corresponding BLER. f TP – Scaling and TP Offset respectively represent the scaling factor between the application throughput and the RLC (Radio Link Control) throughput and the throughput offset. These two parameters model the header information and other supplementary data that does not appear at the application level. They are defined in the service properties. TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user equipment category properties. •
The minimum HSDPA RLC peak throughput in kbps (
DL
min TP P – RLC M b )
M b cell
It corresponds to the lowest of RLC peak throughputs obtained by HSDPA bearer users connected to the cell. •
The maximum HSDPA RLC peak throughput in kbps (
DL
max TP P – RLC M b )
M b cell
It corresponds to the highest of RLC peak throughputs obtained by HSDPA bearer users connected to the cell. •
The number of HSUPA users in the cell ( n M ): c
They are the HSUPA bearer users connected to the cell. •
UL
The HSUPA application throughput in the cell, c, in kbps ( TP A c )
UL
TP A c =
UL
TP A M b
Mb c
•
UL
The uplink cell load factor due to HSUPA traffic ( X HSUPA c ): UL
I tot c HSUPA UL X HSUPA c = --------------------------------UL N tot c Where UL
I tot c HSUPA is the total interference at transmitter received from HSUPA bearer users.
4.3.3.2.4
Sites Tab In the Sites tab, Atoll displays: •
DL
The instantaneous HSDPA throughput carried by the site in kbps ( TP Inst site )
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TP Inst site =
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DL
TP Inst c
c site
•
DL
The instantaneous HSDPA Effective MAC Throughput carried by the site in kbps ( T MAC site in kbps)
DL
TP E – M AC site =
DL
TP E –M AC c
c site
• UL
UL
The HSUPA throughput carried by the site in kbps ( TP site )
TP site =
UL
TP obtained M c
M c site
4.3.4 Appendices 4.3.4.1 Admission Control in the R99 Part During admission control in the R99 part of the simulation, Atoll calculates the uplink load factor of a considered cell assuming the mobile concerned is connected to it. Here, activity status assigned to users is not taken into account. So even if the mobile is not active on UL, it can be rejected due to cell load saturation. To calculate the cell UL load factor, either Atoll takes into account the mobile power determined during power control if mobile was connected in previous iteration, or it estimates a load rise due to the mobile and adds it to the current load. The load rise ( X X
UL
UL
) is calculated as follows:
1 = ---------------------------------------------W 1 + -----------------------------------UL UL Q req R nominal
4.3.4.2 Resources Management 4.3.4.2.1
OVSF Codes Management OVSF codes are managed in the downlink during the simulation since this resource is downlink limited only. Atoll checks the availability of this resource during the simulation, first in the R99 part and then in the HSDPA part. It determines the number of codes that will be consumed by each cell. OVSF codes form a binary tree. Codes of longer lengths are generated from codes of a shorter length. Length-k OVSF codes are generated from length-k/2 OVSF codes. Therefore, if one channel needs 1 length-k/2 OVSF code, it is equivalent to use 2 length-k OVSF codes, or 4 length-2k OVSF codes and so on. 512 512-bit-length codes per cell are available in UMTS HSPA projects. In the R99 part, during the resource control, Atoll determines the number of 512 bit-length codes that will be consumed for each cell. If the cell supports HSPA, Atoll allocates codes for the DL channels used for HSUPA: • •
A 128 bit-length code for the E-HICH and E-RGCH channels (i.e. four 512 bit-length OVSF codes), for each cell. Therefore, Atoll will take four 512-bit-length codes, A 256 bit-length code for the E-AGCH channel (i.e. two 512 bit-length OVSF codes), for each cell. Therefore, Atoll will take two 512-bit-length codes,
If the cell supports HSDPA, Atoll reserves for potential HSDPA bearer users: •
HS – PDSCH – Min
The minimum number of HS-PDSCH codes defined for the cell, N Codes
. They are 16-bit length OVSF codes
HS – PDSCH – Min
(i.e. thirty-two 512 bit-length OVSF codes). Therefore, Atoll will take 32 N Codes •
512-bit-length codes,
A 128 bit-length code per HS-SCCH channel (i.e. four 512 bit-length OVSF codes), for each cell. Therefore, Atoll will take 4 n HS – SCCH 512-bit-length codes,
Then, it allocates to the cell OVSF codes to support R99 bearers required by users: •
A 256 bit-length code per common channel (i.e. two 512 bit-length OVSF codes), for each cell. Therefore, Atoll will Overhead
take 2 N Codes •
276
512-bit-length codes,
A code per cell-receiver link, for TCH (traffic channels). The length of code to be allocated, Code_Length, depends on the user activity. We have:
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Either Code_Length = F spreading Active user when the user is active, DL
Or Code_Length = F spreading Inactive user if the user is inactive. TCH
The number of 512 bit-length OVSF codes needed N Codes is calculated from the length of the code to be allocated as follows: TCH 512 N Codes = ------------------------------Code_Length
Figure 4.15: OVSF Code Tree Indices (Not OVSF Code Numbers) The OVSF code allocation follows the “Buddy” algorithm, which guarantees that: • •
If a k-length OVSF code is used, all of its children with lengths 2k, 4k, …, cannot be used as they will not be orthogonal. If a k-length OVSF code is used, all of its ancestors with lengths k/2, k/4, …, cannot be used as they will not be orthogonal.
Example: We consider a user with a service requiring the UDD64 R99 radio bearer. This user is active on DL while connected to a cell (which does not support HSDPA). The spreading factor for active users has been set to 64 and site equipment requires four overhead downlink channel elements per cell. Atoll will consume four 256 bit-length OVSF codes for common channels (i.e. eight 512 bit-length OVSF codes) and a 64 bit-length OVSF code for traffic channels (i.e. eight additional 512 bit-length OVSF codes). • •
•
In the R99 part, the OVSF code allocation follows the mobile connection order (mobile order in the Mobiles tab). In DC-HSDPA, A-DPCH is only transmitted in the anchor carrier. Therefore, a DCHSDPA user requires R99 resources in the best serving cell only and consumes the same amount of R99 resources as a single-cell HSDPA user. The OVSF code and channel element management is differently dealt with in case of “softer” handover. Atoll allocates OVSF codes for each cell-mobile link while it globally assigns channel elements to a site.
In the HSDPA part, HSDPA and HSPA users are assigned an HSDPA bearer (Fast link adaptation). Therefore, Atoll allocates to the cell: •
16-bit length OVSF codes per cell-receiver, for HS-PDSCH. This figure depends on the HSDPA bearer assigned to the user and on the type of service. HS – PDSCH
For HSDPA users, HSPA VBR and BE service users, Atoll needs 32 N Codes HS – PDSCH
connected to the cell. N Codes
is the number of HS-PDSCH channels required by the HSDPA bearer. HS – PDSCH
For HSPA CBR service users, Atoll needs 32 N Codes HS – PDSCH
to the cell. N Codes
512-bit-length codes for each user
C HSDPABearer 512-bit-length codes for each user connected
is the number of HS-PDSCH channels required by the HSDPA bearer.
DC-HSDPA users have two HSDPA bearers, one for each serving cell. Therefore, one DC-HSDPA user consumes OVSF codes in both cells.
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When HSDPA bearer users (at least one) are connected to the cell, Atoll gives the cell HS – PDSCH – Min
back the minimum number of OVSF codes reserved for HS-PDSCH ( N Codes
). On
the other hand, if no HSDPA bearer user is connected, Atoll still keeps these codes and the codes for HS-SCCH too. This is the same with HSUPA bearer users. Even if no HSUPA bearer user is connected to the cell, Atoll still keeps the codes for E-HICH, E-RGCH and EAGCH channels.
4.3.4.2.2
Channel Elements Management Channel elements are controlled in the R99 and the HSUPA parts of the simulation. Atoll checks the availability of this resource in the uplink and downlink. In the R99 part, during the resource control, Atoll determines the number of channel elements required by each site for R99 bearers in the uplink and downlink. Then, in the HSUPA part, Atoll carries out another resource control after allocating HSUPA bearers. It takes into account the channel elements consumed by HSUPA bearer users in the uplink and recalculates the number of channel elements required by each site in the uplink. In the uplink, Atoll consumes N CE – UL j channel elements for each cell j on a site NI. This figure includes: •
•
Channel elements for R99 bearers: Overhead
•
N CE – UL
•
R99 – T CH N CE – UL
channel elements for control channels, per cell-receiver link, for R99 TCH (traffic channels).
Channel elements for HSUPA bearers: HSUPA
per cell-receiver link, for packet (HSPA - BE) and packet (HSPA - VBR) service users.
HSUPA
C HSUPABearer per cell-receiver link, for CBR service users.
•
N CE
•
N CE
Therefore, the number of channel elements required in the uplink at the site level, N CE – UL N I , is: N CE – UL N I =
NCE – UL j
j NI
In the downlink, Atoll consumes N CE – DL j channel elements for each cell j on a site NI. This figure includes: •
Channel elements for R99 bearers Overhead
•
N CE – DL
•
N CE – DL
R99 – T CH
channel elements for control channels (Pilot channel, Synchronisation channel, common channels), per cell-receiver link, for R99 TCH (traffic channels).
Therefore, the number of channel elements required in the downlink at the site level, N CE – DL N I , is: N CE – DL N I =
NCE – DL j
j NI
•
•
4.3.4.2.3
In DC-HSDPA, A-DPCH is only transmitted on the anchor carrier. Therefore, a DCHSDPA user requires R99 resources in the best serving cell only and consumes the same amount of R99 resources as a single-cell HSDPA user. In case of “softer” handover (the mobile has several links with co-site cells), Atoll allocates channel elements for the best serving cell-mobile link only.
Iub Backhaul Throughput The Iub backhaul throughput is controlled in the R99, the HSDPA and the HSUPA parts of the simulation. Atoll checks the availability of this resource in the uplink and downlink. In the R99 part, during the resource control, Atoll determines the Iub throughput required by each site for R99 bearers in the uplink and downlink. Then, in the HSDPA part, Atoll performs a resource control in the downlink after allocating HSDPA bearers. It takes into account the Iub backhaul throughput consumed by HSDPA bearer users in the downlink and recalculates the Iub backhaul throughput required by each site in the downlink. Finally, in the HSUPA part, Atoll carries out a resource control in the uplink after allocating HSUPA bearers. It takes into account the Iub backhaul throughput consumed by HSUPA bearer users in the uplink and updates the Iub backhaul throughput required by each site in the uplink. In the uplink, the Iub backhaul throughput consumed by each cell j on a site NI, TP Iub – UL j , includes:
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•
The Iub backhaul throughput required for R99 bearers: •
•
R99 – T CH
TP Iub – UL per cell-receiver link, for R99 TCH (traffic channels).
The Iub backhaul throughput required for HSUPA bearers: HSUPA
•
TP Iub
per cell-receiver link, for HSPA BE and VBR service users.
•
HSUPA TP Iub
C HSUPABearer per cell-receiver link, for HSPA CBR service users.
Therefore, the Iub backhaul throughput required on uplink at the site level, TP Iub – UL N I , is: TP Iub – UL N I =
TPIub – UL j
j NI
In the downlink, the Iub backhaul throughput consumed by each cell j on a site NI, TP Iub – DL j , includes: •
•
The Iub backhaul throughput required for R99 bearers: Overhead
•
TP Iub – DL
•
R99 – T CH TP Iub – DL
for R99 control channels (Pilot channel, Synchronisation channel, common channels). per cell-receiver link, for R99 TCH (traffic channels).
The Iub backhaul throughput required for HSDPA bearers: •
TP Iub
HSDPA
per cell-receiver link, for HSDPA, HSPA BE and VBR service users.
•
HSDPA TP Iub
C HSDPABearer per cell-receiver link, for HSPA CBR service users.
HSDPA
With TP Iub
DL
HSDPA
= TP P – RLC + Overhead Iub
DL
TP P – RLC
Therefore, the Iub backhaul throughput required on downlink at the site level, TP Iub – DL N I , is: TP Iub – DL N I =
TPIub – DL j
j NI
•
•
In DC-HSDPA, A-DPCH is only transmitted on the anchor carrier. Therefore, a DCHSDPA user requires R99 resources in the best serving cell only and consumes the same amount of R99 resources as a single-cell HSDPA user. On the other hand, the DC-HSDPA user has two HSDPA bearers (one for each serving cell) and consumes HSDPA resources in both cells. In case of “softer” handover (the mobile has several links with co-site cells), Iub backhaul throughput is consumed by the best serving cell-mobile link only.
4.3.4.3 Downlink Load Factor Calculation Atoll calculates a downlink load factor for each cell (available in the Cells tab of any simulation result) and each connected mobile (available in the Mobiles tab of any given simulation result).
4.3.4.3.1
Downlink Load Factor per Cell Approach for downlink load factor evaluation is highly inspired by the downlink load factor defined in the book “WCDMA for UMTS by Harry Holma and Antti Toskala”. DL
Q req - be the required quality. Let CI req = --------DL Gp DL
DL
G p and Q req are the processing gain on downlink and the Eb/Nt target on downlink respectively. In case of soft-handoff, required quality is limited to the effective contribution of the transmitter. DL
P tx c = P pilot c + P SCH c + P otherCCH c +
Ptch c tch
DL
ortho
nonOrtho
P tx c = P CCH c + P CCH
c +
Ptch c tch
where
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ortho
P CCH c = P pilot c + P otherCCH c nonOrtho
P CCH
c = P SCH c
At mobile level, we have a required power, Ptch: term
P tch c = CI req I extra c + I inter – carrier c + I inter – techno log y c + I intra c + N 0
LT r
DL
With r = 1 when the user is active on the downlink and r = r c when the user is inactive. In case of an HSDPA bearer user, DL
r = f act – ADPCH . P tch c = CI req
I extra c + I inter – carrier c + I inter – techno log y c DL
nonOrtho
nonOrtho
P tx c – P CCH c – P tch c P CCH c - + ------------------------------ + N term + 1 – F ortho BTS ------------------------------------------------------------------------------0 LT LT
L r T
DL
I extra c + I inter – carrier c + I inter – techno log y c L T r + 1 – F ortho BTS P tx c r
+ nonOrtho term F ortho BTS P CCH c r + N0 LT r P tch ic = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------1 -------------------- + 1 – F ortho BTS CIreq r I intra c is the total power received at the receiver from the cell with which it is connected. I extra c is the total power received at the receiver from other cells. I inter – carrier c is the inter-carrier interference received at the terminal. I inter – techno log y c is the inter-technology interference received at the terminal from an external transmitter. We have: ortho
nonOrtho
P CCH c + P CCH
DL P tx c
=
c
I extra c + I inter – carrier c + I inter – techno log y c L T r DL nonOrtho term + 1 – F P c r + F P c r + N L r ortho BTS tx ortho BTS CCH 0 T ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- + 1 ------------------1 F + – ortho BTS tch CI req r
I extra c + I inter – carrier c + I inter – techno log y c L T r ------------------------------------------------------------------------------------------------------------------------------------------- P DL tx c DL DL P tx c P tx c = P ortho c + P nonOrtho c + ---------------------------------------------------------------------------------------------------------------------------------------------------------------- + CCH CCH 1 -------------------- + 1 – F ortho BTS tch CI req r
DL
1 – F ortho BTS P tx c r --------------------------------------------------------------------------- + 1 tch -------------------- + 1 – F ortho BTS CI req r
nonOrtho
term
F ortho BTS P CCH c r + N0 LT r ----------------------------------------------------------------------------------------------------------------1 - 1 F ------------------+ – ortho BTS tch CI req r
I extra c + I inter – carrier c + I inter – techno log y c L T r ------------------------------------------------------------------------------------------------------------------------------------------ + 1 – F ortho BTS r DL P c DL tx -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- P DL ic P tx c – tx 1 - + 1 – F ------------------ ortho BTS tch CI req r
ortho
nonOrtho
= P CCH c + P CCH
280
c +
nonOrtho
term
F ortho BTS P CCH c r + N0 LT r ----------------------------------------------------------------------------------------------------------------1 -------------------- + 1 – F ortho BTS tch CI req r
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term
c r + N0 LT r F ortho BTS P CCH ----------------------------------------------------------------------------------------------------------------1 - 1 F ------------------+ – ortho BTS tch CIreq r DL P tx c = -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------I extra c + I inter – carrier c + I inter – techno log y c L T r ------------------------------------------------------------------------------------------------------------------------------------------ + 1 – F ortho BTS r DL P c tx ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 1– 1 - + 1 – F ------------------ ortho BTS tch r CI req ortho
nonOrtho
P CCH c + P CCH
c +
Therefore, the downlink load factor can be expressed as:
X
DL
I extra c + I inter – carrier c + I inter – techno log y c L T r ------------------------------------------------------------------------------------------------------------------------------------------- + 1 – F ortho BTS r DL P tx c = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------1 - + 1 – F ------------------ tch ortho BTS CI req r
The downlink load factor represents the signal degradation in relation to the reference interference (thermal noise plus synchronisation channel power).
4.3.4.3.2
Downlink Load Factor per Mobile Atoll evaluates the downlink load factor for any connected mobile as follows: X
DL
DL
I tot c = ---------------DL N tot c
4.3.4.4 Uplink Load Factor Due to One User UL
This part details how Atoll calculates the contribution of one user to the UL load factor ( X k ). UL
In this calculation, we assume that the cell UL reuse factor ( F txi ic ) is constant. The result depends on the option used to calculate Nt (Without useful signal or Total noise that you may select in Global parameters). Without Useful Signal Option UL
P b k req W - ---------------------------------------------------------------------------------------------------------------UL Q req k = ------------------------R99 UL tx TP P – UL k I intra – P b k req + I extra + I inter – carrier + N 0 UL
P b k req W UL - -----------------------------------------------------------------------Q req k = ------------------------UL R99 UL tx TP P – UL k I intra F – P b k req + N 0 R99
R99
TP P – UL k TP P – UL k UL UL UL tx - = Q UL P b k req 1 + Qreq k ------------------------+ N0 req k -------------------------- I intra F W W R99
UL
P b k req
R99
TP P – UL k TP P – UL k UL tx - I intra F UL Q UL Q req k ------------------------req k -------------------------- N 0 W W = ----------------------------------------------------------------------------------- + ----------------------------------------------------------------R99 R99 TP P – UL k TP P – UL k UL UL 1 + Q req k -------------------------1 + Q req k -------------------------W W R99
req TP P – UL k Ec UL We note ------ k = Q req k ------------------------ Nt E – DPDCH W UL
tx
I intra F N0 UL P b k req = ------------------------------------------------------ + ----------------------------------------------------- 1 1 - + 1 --------------------------------------- + 1 --------------------------------------req req Ec Ec ---- ---- Nt- k Nt- k E – DPDCH E – DPDCH As I intra =
Pb
UL
k req , we have:
K
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I intra = I intra F
UL
1
tx
1
- + N 0 ------------------------------------------------------ ----------------------------------------------------- K
N0
©Forsk 2015 tx
1 - + 1 --------------------------------------Ec- req ---- Nt k E – DPDCH
K
1 - + 1 --------------------------------------Ec- req ---- Nt k E – DPDCH
1
-----------------------------------------------------
1 - + 1 --------------------------------------req Ec ---- Nt- k E – DPDCH = -------------------------------------------------------------------------------------UL 1 1–F ----------------------------------------------------- K 1 - + 1 --------------------------------------req Ec ---- Nt- k E – DPDCH K
I intra
UL
tx
N0 F I intra = -------------------------------------------------------------------------------------1 ----------------------------------------------------------------------------–1 UL 1 F ----------------------------------------------------- K 1 - + 1 --------------------------------------req Ec ---- Nt- k E – DPDCH
X
UL
UL I intra + I extra + I inter – carrier I intra F 1 = ------------------------------------------------------------------------------= --------------------------------------= ---------------------------------UL tx tx tx I intra + I extra + I inter – carrier + N 0 I intra F + N 0 N0 1 + ------------------------UL I intra F
Therefore, we have: X
UL
= F
UL
1
----------------------------------------------------- K
1 - + 1 --------------------------------------req Ec ---- Nt- k E – DPDCH
So, we can conclude that the contribution of one user to the UL load is defined as: UL
X k = F
UL
1 ------------------------------------------------------ 1 - + 1 --------------------------------------req Ec ---- Nt- k E – DPDCH
Total Noise Option UL
P b k req W UL - ------------------------------------------------------------------------------Q req k = ------------------------R99 tx TP P – UL k I intra + I extra + I inter – carrier + N 0 UL
P b k req W - --------------------------------------UL Q req k = ------------------------ UL R99 tx TP P – UL k I intra F + N 0 R99
TP P – UL k UL UL - I intra F UL + N tx P b k req = Q req k ------------------------0 W R99
req TP P – UL k Ec UL We note ------ k = Q req k ------------------------ Nt E – DPDCH W req Ec UL UL tx P b k req = ------ k I intra F + N 0 Nt E – DPDCH
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Pb
UL
As I intra =
k req , we have:
K
I intra = I intra F
UL
tx
+ N0
req
- k ----Nt E – DPDCH Ec
K tx
N0
req
- k ----Nt E – DPDCH Ec
K I intra = ------------------------------------------------------------UL 1–F
X
UL
UL I intra + I extra + I inter – carrier I intra F 1 = ------------------------------------------------------------------------------= --------------------------------------= ---------------------------------UL tx tx tx I intra F + N 0 N0 I intra + I extra + I inter – carrier + N 0 1 + ------------------------UL I intra F
Therefore, we have: X
UL
= F
UL
req
Ec- ----k Nt E – DPDCH
K
So, we can conclude that the contribution of one user to the UL load is defined as: UL
X k = F
UL
req
Ec ------ k Nt E – DPDCH
4.3.4.5 Inter-carrier Power Sharing Modelling Inter-carrier power sharing enables the network to dynamically allocate available power from R99-only and HSDPA carriers among HSDPA carriers. In this part, we will consider the most common scenario, a network consisting of an R99-only carrier (c1) and an HSDPA carrier with dynamic power allocation (c2) (c2 does not support HSUPA). As explained in The User Manual, the maximum power of the HSDPA cell must be set to the same value as the maximum shared power in order to use power sharing efficiently. In this case, the HSDPA cell can use 100% of the available power, i.e, all of the R99-only cell’s unused power can be allocated to the HSDPA cell. Let’s take the following example to measure the impact of the inter-carrier power sharing. •
1st case: Inter-carrier power sharing is not activated
On c1, we have: P max Tx c 1 = 43dBm and P tx – R99 Tx c 1 = 39.1dBm . On c2, we have: P max Tx c 2 = 43dBm , P tx – R99 Tx c 2 = 36.1dBm and P Headroom Tx c 2 = 0dB . Therefore, P HSDPA Tx c 2 = P max Tx c 2 – P tx – R99 Tx c 2 – P Headroom Tx c 2 = 42dBm •
2nd case: Inter-carrier power sharing is activated and P max Tx = 46dBm
On c1, we have: P max Tx c 1 = 43dBm and P tx – R99 Tx c 1 = 39.1dBm . On c2, we have: P max Tx c 2 = 46dBm , P tx – R99 Tx c 2 = 36.1dBm and P Headroom Tx c 2 = 0dB . Therefore, P HSDPA Tx c 2 = P max Tx – P tx – R99 Tx c 1 – P tx – R99 Tx c 2 – P Headroom Tx c 2 = 44.4dBm
4.3.4.6 Best Serving Cell Determination in Monte Carlo Simulations - Old Method Before Atoll 2.8.0, best serving cell determination used to be performed by selecting the best carrier within transmitters according to the selected method (site equipment) and then the best transmitter using the best carrier. To switch back to this method, add the following lines in the Atoll.ini file: [CDMA] MultiBandSimu = 0 The method is described below:
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For each station txi containing Mb in its calculation area and using a frequency band supported by the Mb’s terminal. Determination of BestCarrier k txi M b . If a given carrier is specified for the service requested by Mb and if it is used by txi BestCarrier k txi M b is the carrier specified for the service. Else the carrier selection mode defined for txi is considered. If carrier selection mode is “Min. UL Load Factor” For each carrier ic used by txi, we calculate current loading factor: UL
I tot txi ic UL UL - + X X k txi ic = ---------------------------UL N tot txi ic EndFor UL
BestCarrier k txi M b is the carrier with the lowest X k txi ic Else if carrier selection mode is “Min. DL Total Power” BestCarrier k txi M b is the carrier with the lowest P tx txi ic k Else if carrier selection mode is “Random” BestCarrier k txi M b is randomly selected Else if carrier selection mode is "Sequential" UL
UL
BestCarrier k txi M b is the first carrier so that X k txi ic X max Calculation of BTS P c txi M b BestCarrier Q pilot txi BestCarrier = -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------k DL DL P tot txi BestCarrier k txi M b + I extra BestCarrier k txi M b + DL DL Term I BestCarrier txi M + I BestCarrier txi M + N inter – carrier k b inter – techno log y k b 0 If user selects “without Pilot” BTS P c txi M b BestCarrier Q pilot txi BestCarrier = --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------k DL DL P tot txi BestCarrier k txi M b + I extra BestCarrier k txi M b DL + I DL BestCarrier k txi M b + I inter – techno log y BestCarrier k txi M b inter – carrier Term N + – 1 – P txi M BestCarrier 0 BTS c b Rejection of station txi if the pilot is not received pilot
If Q pilot txi M b BestCarrier Q req Mobility M b then txi is rejected by Mb k
max
If Q pilot txi M b BestCarrier Q pilot M b k
k
Admission control (If simulation respects a loading factor constraint and Mb was not connected in previous iteration). UL
UL
If X k txi BestCarrier txi M b X max , then txi is rejected by Mb Else max
Q pilot M b = Q pilot txi M b BestCarrier k
k
Tx BS M b = txi Endif EndFor If no TxBS has been selected, Mb has failed to be connected to the network and is rejected.
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4.4 UMTS HSPA Prediction Studies 4.4.1 Best Serving Cell and Active Set Determination The mobile active set is the list of the cells to which the mobile is connected. The active set may consist of one or more cells depending on whether the service supports soft handover and on the terminal active set size. The best serving cell and other cells of the active set are selected among a list of potential serving cells which fulfil a set of conditions. Potential serving cells must use a frequency band with which the terminal is compatible. They must also belong to layers supported by the service and the terminal, and these layers must support a speed higher than the user mobility. In addition, the pilot signal level received from these cells must exceed the defined minimum RSCP threshold. The layer priority, the quality of the pilot ( Q pilot ), the handover margin ( M HO ) and the cell individual offset ( CIO ) are considered to rank all potential serving cells and determine the best serving cell. Among all potential serving cells, Atoll first selects the cells which belong to the highest priority layer and then, the one with the highest RSCP. This cell is referred to as the best serving cell candidate ( c BC ). Then, Atollcalculates the best server indicator ( I BS ) for the best serving cell candidate and the other potential serving cells ( c OC ): I BS c BC = Q pilot c BC + M HO c BC + C IO c BC
for the best serving cell candidate,
I BS c OC = Q pilot c OC + C IO c OC for the other potential serving cells. Atoll ranks the potential serving cells according to the best server indicator ( I BS ). The cell with the highest I BS is selected as the best serving cell if its best server indicator ( I BS ) exceeds the Ec/I0 threshold defined in the properties of the mobility type. Each other cell of the active set is selected among the other potential serving cells as follows: • • •
It must use the same carrier as the best serving cell. The pilot quality difference between the cell and the best serving cell must not exceed the AS-threshold set per cell. It must belong to the neighbour list of the best serving cell if it is located on a site where the equipment imposes this restriction (the “restricted to neighbours” option selected in the equipment properties). You can return to the old best serving cell selection mechanism as in Atoll 3.2.1, by setting an option in the Atoll.ini file. For more information about setting options in the Atoll.ini file, see the Administrator Manual.
4.4.2 Point Analysis - AS Analysis Tab Let us suppose a receiver with a terminal, a service and a mobility type. This receiver does not create any interference. You can make the prediction for a specific carrier, for all carriers, for a specific layer, or for all layers. For DC-HSDPA, MC-HSDPA and DB-MC-HSDPA users, selecting one specific carrier or one layer associated with one unique carrier is not suitable. If you have selected a DC-HSDPA user or a MC-HSDPA user, select "Best (All/Specific band)" as the carrier or layers associated with several carriers. For a DB-MC-HSDPA user, select "Best (All bands)" as the carrier or layers associated with several carriers on different frequency bands. The analysis is based on the following parameters: • • •
The uplink load factor and the downlink total power of cells, The available HSDPA power of the cell in case of an HSDPA bearer user, The cell UL reuse factor, the cell UL load factor due to HSUPA and the maximum cell UL load factor for HSUPA bearer users.
These parameters can be results of a given simulation, average values calculated from a group of simulations, or user-defined cell inputs. In the last case, when no value is defined in the Cells table, Atoll uses the following default values: • • • • •
Total transmitted power = 50% of the maximum power (i.e, 40 dBm if the maximum power is set to 43 dBm) Uplink load factor = 50%. Uplink reuse factor = 1 Uplink load factor due to HSUPA = 0% Maximum uplink load factor = 75%
On the other hand, no default value is used for the HSDPA power; this parameter must be defined by the user. Results are displayed for any point of the map where the pilot signal level exceeds the defined minimum RSCP.
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4.4.2.1 Bar Graph and Pilot Sub-Menu Atoll performs a first selection of potential serving cells depending on if you have chosen "Carrier" or "Layer". We can consider the following cases: 1st case: Analysis based on a specific carrier The carrier that can be used is fixed. The potential serving cells are selected among all transmitters i that contain the receiver in their calculation areas and that use the selected carrier ic. 2nd case: Analysis based on all carriers of all frequency bands/a specific frequency band If you have selected "Best (All bands)", the potential serving cells are selected among all transmitters i that contain the receiver in their calculation areas. If the frequency band is fixed ("Best (Specific band)"), the potential serving cells are selected among all transmitters i that contain the receiver in their calculation areas and that use a carrier of the selected frequency band. 3rd case: Analysis based on the best layer The layer that can be used is fixed. The potential serving cells are selected among all transmitters i that contain the receiver in their calculation areas and that have cells using the selected layer. 4th case: Analysis based on all layers The potential serving cells are selected among all transmitters i that contain the receiver in their calculation areas. In addition, potential serving cells must satisfy the following conditions: • • •
They must use a frequency band with which the terminal is compatible. They must also belong to layers supported by the service and the terminal, and these layers must support a speed higher than the user mobility. The pilot signal level received from these cells must exceed the defined minimum RSCP threshold.
Ec/I0 (or Q pilot ic ) Evaluation Atoll calculates the pilot quality for all potential serving cells (i, ic). ic is the studied carrier and icadj is another carrier adjacent to ic. The interference reduction factor, RF ic ic adj , is defined between ic and icadj and set to a value different from 0. Two ways may be used to calculate I0. Option Total noise: Atoll considers the noise generated by all the transmitters and the thermal noise. Option Without pilot: Atoll considers the total noise deducting the pilot signal. Calculation option may be selected in Global parameters. Therefore, we have: BTS P c i ic Q pilot i ic = --------------------------------------------DL I 0 ic With, DL
DL
DL
DL
DL
term
I 0 ic = P tot i ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0
for the total noise option,
And DL
DL
DL
DL
DL
term
I 0 ic = I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0 pilot option. 1st step: P c i ic calculation for each potential serving cell (i, ic) P c i ic is the pilot power of a transmitter i on carrier ic at the receiver. P pilot i ic P c i ic = ------------------------LT I
L T is the total loss between transmitter i and receiver. I
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L Tx L path L term L body L Indoor M Shadowing – Ec Io L T = -----------------------------------------------------------------------------------------------------------------------------------I G Tx G term DL
DL
DL
2nd step: P tot j ic , P tot i ic and P tot j ic adj calculations We have: DL
I extra ic =
DL
P tot j ic
txj j i
P SCH ic DL DL DL I intra ic = P tot i ic – BTS P tot i ic – ------------------ LT
Ptot j icadj DL
DL
txj j I inter – carrier ic = ---------------------------------------RF ic ic adj
and Tx
DL
I inter – techno log y ic =
P Transmitted ic i
------------------------------------Tx Tx m L ICP ni
ic i ic
total
DL
For each transmitter of the network, P tot ic is the total power received at the receiver from the transmitter on the carrier ic. P Tx ic DL P tot ic = ---------------LT P Tx ic is the total power transmitted by the transmitter on the carrier ic.Total power transmitted by each cell is either a simulation result (provided in Simulation properties (Cells tab)) or a value user-defined in Cell properties. DL
For each transmitter of the network, P tot ic adj is the total power received at the receiver from the transmitter on the carrier icadj. P Tx ic adj DL P tot ic adj = ---------------------LT P Tx ic adj is the total power transmitted by the transmitter on the carrier icadj. Total power transmitted by each cell is either a simulation result (provided in Simulation properties (Cells tab)) or a value user-defined in Cell properties. term
3rd step: N 0 term
N0
calculation Tx DL
= NF Term K T W NR inter – techno log y DL
4th step: I 0 ic and Q pilot i ic evaluation using formulas described above DL
5th step: G macro – diversity calculation DL
The macro-diversity gain, G macro – diversity , models the decrease in shadowing margin due to the fact there are several available pilot signals at the mobile. DL
npaths
G macro – diversity = M Shadowing – Ec Io – M Shadowing – Ec Io npaths
M Shadowing – Ec Io is the shadowing margin when the mobile receives n pilot signals (not necessarily from transmitters belonging to the mobile active set). This parameter is determined from cell edge coverage probability and Ec/I0 standard deviation. When the Ec/I0 standard deviation is set to 0, the macro-diversity gain equals 0. 6th step: Determination of the best serving cell
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Among all potential serving cells, Atoll first selects the cells which belong to the highest priority layer and then, the one with the highest RSCP. This cell is referred to as the best serving cell candidate ( c BC ). Then, Atoll calculates the best server indicator ( I BS ) for the best serving cell candidate ( c BC ) and the other potential serving cells ( c OC ): I BS c BS = Q pilot c BS + M HO c BS + C IO c BS
for the best serving cell candidate,
I BS c OC = Q pilot c OC + C IO c OC for the other potential serving cells. Atoll takes the cell with the highest best server indicator ( c max I Resulting
cell edge coverage probability, Q pilot Resulting
Resulting
. Q pilot
BS
) and calculates the best pilot quality received with a fixed
DL
= G macro – diversity Q pilot c max I
req
Resulting
Q pilot , it means pilot quality at the receiver exceeds Q pilot
If Q pilot
BS
x% of time (x is the fixed cell edge coverage
probability). The cell enters the active set as best serving cell, BS. Its carrier (icBS) will be used by other transmitters of the active set (when active set size is greater than 1). Pilot is available. Resulting
If Q pilot
req
Q pilot , no cell among the potential serving cells can enter the active set. Pilot is unavailable.
7th step: Determination of active-set Then, pilot qualities received from all potential serving cells other than BS ( Q pilot i ic BS ) are recalculated to determine the entire receiver active set (when active set size is greater than 1). Same formulas and calculation method are used to update DL
I 0 ic BS value and determine Q pilot i ic BS . We have: BTS P c i ic Q pilot i ic = --------------------------------------------DL I 0 ic With, DL
DL
DL
DL
DL
term
I 0 ic = P tot i ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0
for the total noise option,
And DL
DL
DL
DL
DL
term
I 0 ic = I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0
– 1 – BTS P c i ic for the without
pilot option. Other cells (i,icBS) in the active set must satisfy the following criteria: Q pilot i ic BS – Q pilot BS AS_threshold BS i ic BS neighbour list BS (optionally) Number of Cells in Active Set This is a user-specified input in the Terminal properties. It corresponds to the active set size. Thermal Noise This parameter is calculated as described above (3rd step). I0 (Best Server) I0 (Best server) is the total noise received at the receiver on icBS. The notation “Best server” refers to the best serving cell of active set. This is relevant when using the calculation option “Without pilot”. In this case, it informs that the pilot signal of the best serving cell (BS) is deducted from the total noise. Downlink Macro-Diversity Gain This parameter is calculated as described above (5th step).
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4.4.2.2 Downlink R99 Sub-Menu The Downlink R99 sub-menu contains R99-related results. Atoll calculates the traffic channel quality from each cell (k,icBS) of the receiver’s active set at the receiver. No power control is performed as in simulations. Here, Atoll determines the downlink traffic channel quality at the receiver for the maximum allowed traffic channel power per transmitter. Then, after combination, the total downlink traffic channel quality is evaluated and compared with the specified target quality. Eb/Nt Target DL
Eb/Nt target ( Q req ) is defined for a given R99 bearer, a mobility type and a reception equipment. This parameter is available in the R99 Bearer Selection table. Compressed mode is operated when amobile supporting compressed mode is connected to a cell located on a site with a compressed-mode-capable equipment, and •
Either the received Ec/I0 is lower than the Ec/I0 activation threshold (Global Resulting
parameters): Q pilot •
CM – activation
Q pilot
,
Or the pilot RSCP is lower than the pilot RSCP activation threshold (Global CM – activation
parameters): P c RSCP pilot
.
When compressed mode is activated, the downlink Eb/Nt target is increased by the value DL
user-defined for the DL Eb/Nt target increase field (Global parameters), Q req . Required transmitter power on traffic channels req
The calculation of the required transmitter power on traffic channels ( P tch ) may be divided into three steps. DL
1st step: Q max k ic BS evaluation for each cell DL
Let us assume the following notation: Eb/Nt max corresponds to Q max Therefore, for each cell (k,icBS), we have: DL
BTS P b – max k ic BS DL DL - G DL Q max k ic BS = -----------------------------------------------------p G Div DL N tot ic BS max
P tch DL With P b – max k ic BS = ---------LT k
DL
DL
DL
DL
DL
term
and N tot ic BS = I intra ic BS + I extra ic BS + I inter – carrier ic BS + I inter – techno log y ic BS + N 0 Where max
P tch is the maximum power allowed on traffic channels. This parameter is user-defined in the R99 Radio Bearers table. DL
N tot ic BS is the total noise at the receiver on the carrier of the best serving cell. DL
I intra ic BS is the intra-cell interference at the receiver on the carrier of the best serving cell. P SCH k ic BS DL I intra ic BS = P DL k ic – BTS F ortho P DL k ic – ----------------------------- tot BS tot BS L T
DL
I extra ic BS is the extra-cell interference at the receiver on the carrier of the best serving cell. DL
I extra ic BS =
Ptot j icBS DL
j j k DL
I inter – carrier ic BS is the inter-carrier interference at the receiver on the carrier of the best serving cell.
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Ptot j icadj DL
DL
txj j I inter – carrier ic BS = ---------------------------------------RF ic BS ic adj
icadj is a carrier adjacent to icBS. RF ic BS ic adj is the interference reduction factor, defined between ic and icadj and set to a value different from 0. DL
I inter – techno log y ic BS is the inter-technology interference at the receiver on the carrier of the best serving cell.
DL
I inter – techno log y ic BS =
ni
ic i is the i Tx m
ICP ic ic i
BS
th
Tx
P Transmitted ic i ----------------------------------------Tx Tx m L total ICP ic ic i
BS
interfering carrier of an external transmitter
is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the
frequency gap between ic i (external network) and ic BS . 2nd step: Calculation of the total traffic channel quality DL
Q MAX is the traffic channel quality at the receiver on icBS after signal combination of all the transmitters k of the active set. On downlink, if there is no handoff, we have: DL
DL
Q MAX ic BS = Q max k ic BS For any other handoff status, we have: DL
DL
Q MAX ic BS = f rake efficiency
Qmax k icBS DL
k
Where DL
f rake efficiency is the downlink rake efficiency factor defined in Terminal properties. req
3rd step: P tch calculation DL
Q req req - P max P tch = -------------------------tch DL Q MAX ic BS Compressed mode is operated when a mobile supporting compressed mode is connected to a cell located on a site with a compressed-mode-capable equipment, and •
Either the received Ec/I0 is lower than the Ec/I0 activation threshold (Global Resulting
parameters): Q pilot •
CM – activation
Q pilot
.
Or the pilot RSCP is lower than the pilot RSCP activation threshold (Global CM – activation
parameters): P c RSCP pilot
When compressed mode is activated, the downlink Eb/Nt target is increased by the value DL
user-defined for the DL Eb/Nt target increase field (Global parameters), Q req . In this DL
DL
Q req Q req req - P max case, we have: P tch = -----------------------------tch DL Q MAX ic BS Max Eb/Nt for Each Cell of Active Set For each cell (k,icBS), we have: DL
BTS P b – max k ic BS DL DL - G DL Q max k ic BS = -----------------------------------------------------p G Div DL N tot ic BS
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P tch DL With P b – max k ic BS = ---------LT k
DL
DL
DL
DL
DL
term
N tot ic BS = I intra ic BS + I extra ic BS + I inter – carrier ic BS + I inter – techno log y ic BS + N 0
max
req
P tch – P tch P SCH k ic BS DL I intra ic BS = P DL k ic – BTS F ortho P DL k ic – -----------------------------– 1 – BTS max (--------------------------,0) tot tot BS BS L L T
DL
I extra ic BS =
Tk
Ptot j icBS DL
j j k
Ptot j icadj DL
DL
j ---------------------------------------I inter – carrier ic BS = txj RF ic BS ic adj
DL
I inter – techno log y ic BS =
ni
Tx
P Transmitted ic i ----------------------------------------Tx Tx m L total ICP ic ic i
BS
Where req
P tch is the required transmitter power on traffic channels. Max Eb/Nt DL
Q MAX is the traffic channel quality at the receiver on icBS after signal combination of all the transmitters k of the active set. On downlink, if there is no handoff, we have: DL
DL
Q MAX ic BS = Q max k ic BS For any other handoff status, we have: DL
DL
Q MAX ic BS = f rake efficiency
Qmax k icBS DL
k
Where DL
f rake efficiency is the downlink rake efficiency factor defined in Terminal properties. DL
DL
DL
DL
DL
Therefore, the service on the downlink traffic channel is available if Q MAX ic BS Q req (or Q MAX ic BS Q req Q req when compressed mode is activated). Effective Eb/Nt DL
Q eff is the effective traffic channel quality at the receiver on icBS. DL
DL
DL
DL
DL
DL
DL
Q eff = min Q MAX Q req (or Q eff = min Q MAX Q req Q req when compressed mode is activated). Downlink Soft Handover Gain DL
G SHO corresponds to the DL soft handover gain. DL
Q MAX ic BS DL G SHO = -----------------------------------------------DL max Qmax k ic BS DL
DL
max Qmax k ic BS corresponds to the highest Q max k ic BS value.
4.4.2.3 Uplink R99 Sub-Menu The Uplink R99 sub-menu contains R99-related results.
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For each cell (k,icBS) in the receiver’s active set, Atoll calculates uplink traffic channel quality from receiver. No power control is performed as in simulations. Here, Atoll determines the uplink traffic channel quality at the cell for the maximum terminal power allowed. Then, the total uplink traffic channel quality is evaluated with respect to the receiver handover status. From this value, Atoll calculates the terminal power required to obtain the R99 bearer and compares it to the maximum terminal power allowed. Max Terminal Power max
Max terminal power ( P term ) is an input user-defined for each terminal. It corresponds to the terminal’s maximum power. Required Terminal Power req
The calculation of the terminal power required to obtain an R99 bearer ( P term – R99 ) may be divided into three steps. UL
1st step: Q max k ic BS evaluation for each cell For each cell (k,icBS) in the receiver’s active set, we have: UL
term P b – max k ic BS UL UL - G UL Q max k ic BS = -------------------------------------------------------p G Div UL N tot k ic BS max
UL
P term 1 – r c UL With P b – max k ic BS = --------------------------------------LT k
UL
N tot k ic BS is the total noise at the transmitter on the carrier of the best serving cell. This value is calculated from the cell UL
uplink load factor X k ic BS . tx
N0 UL N tot k ic BS = -----------------------------------UL 1 – X k ic BS tx
N 0 is the transmitter thermal noise. 2nd step: Calculation of the total traffic channel quality UL
Q MAX ic BS is the traffic channel quality at the transmitter on icBS after signal combination of all the transmitters k of the active set. UL
UL
If there is no handoff (1/1): Q MAX ic BS = Q max k ic BS For soft handoff (2/2): UL
UL
UL
Q MAX ic BS = G macro – diversity 2 links max Q max k ic BS UL
G macro – diversity 2 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. UL
UL
max Q max k ic BS corresponds to the highest Q max k ic BS value. For soft-soft handoffs (3/3): UL
UL
UL
Q MAX ic BS = G macro – diversity 3 links max Q max k ic BS UL
G macro – diversity 3 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. For softer and softer-softer handoffs (1/2 and 1/3): UL
UL
Q MAX ic BS = f rake efficiency
Qmax k icBS UL
k
For softer-soft handoffs (2/3), there are two possibilities. If the MRC option is selected (option available in Global parameters), we have:
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UL UL UL Q MAX ic BS = G macro – diversity 2 links max f rake efficiency
UL
UL
Q max k ic BS Q max
k on the same site
k on the same site
k ic BS
Else, UL
UL
UL
Q MAX ic BS = G macro – diversity 2 links max Q max k ic BS req
3rd step: P term – R99 calculation req
P term – R99 is the required terminal power. UL
Q req req - P max P term – R99 = -------------------------term UL Q MAX ic BS UL
Q req is the uplink traffic quality target defined by the user for a given reception equipment, a given R99 bearer and a given mobility type. This parameter is available in the R99 Bearer Selection table. Compressed mode is operated when a mobile supporting compressed mode is connected to a cell located on a site with a compressed-mode-capable equipment, and •
The received Ec/I0 is lower than the Ec/I0 activation threshold (Global parameters): Resulting
Q pilot •
CM – activation
Q pilot
.
The pilot RSCP is lower than the pilot RSCP activation threshold (Global parameters): CM – activation
P c RSCP pilot
When compressed mode is activated, the uplink Eb/Nt target is increased by the value UL
user-defined for the UL Eb/Nt target increase field (Global parameters), Q req . In this UL
UL
Q req Q req req - P max case, we have: P term – R99 = -----------------------------term UL Q MAX ic BS
req
max
Therefore, the service on the uplink traffic channel is available if P term – R99 P term . Eb/Nt Max For each cell (k,icBS) in the receiver’s active set, we have: UL
term P b – max k ic BS UL UL - G UL Q max k ic BS = -------------------------------------------------------p G Div UL N tot k ic BS max
UL
P term 1 – r c UL With P b – max k ic BS = --------------------------------------LT k
UL
N tot k ic BS is the total noise at the transmitter on the carrier of the best serving cell. This value is calculated from the cell UL
uplink load factor X k ic BS . tx
max
req
N0 P term – P term – R99 UL - + 1 – term max (-----------------------------------------N tot k ic BS = -----------------------------------,0) UL LT 1 – X k ic BS k tx
N 0 is the transmitter thermal noise. UL
Q MAX ic BS is the traffic channel quality at the transmitter on icBS after signal combination of all the transmitters k of the active set. UL
UL
If there is no handoff (1/1): Q MAX ic BS = Q max k ic BS For soft handoff (2/2): UL
UL
UL
Q MAX ic BS = G macro – diversity 2 links max Q max k ic BS
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UL
G macro – diversity 2 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. UL
UL
max Q max k ic BS corresponds to the highest Q max k ic BS value. For soft-soft handoffs (3/3): UL
UL
UL
Q MAX ic BS = G macro – diversity 3 links max Q max k ic BS UL
G macro – diversity 3 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. For softer and softer-softer handoffs (1/2 and 1/3): UL
UL
Q MAX ic BS = f rake efficiency
Qmax k icBS UL
k
For softer-soft handoffs (2/3), there are two possibilities. If the MRC option is selected (option available in Global parameters), we have: UL UL UL Q MAX ic BS = G macro – diversity 2 links max f rake efficiency
UL
UL
Q max k ic BS Q max
k on the same site
k on the same site
k ic BS
Else, UL
UL
UL
Q MAX ic BS = G macro – diversity 2 links max Q max k ic BS Effective Eb/Nt UL
Q eff is the effective traffic channel quality at the transmitter on icBS. UL
UL
UL
UL
UL
UL
UL
Q eff = min Q MAX Q req (or Q eff = min Q MAX Q req Q req when compressed mode is activated). Uplink Soft Handover Gain UL
G SHO corresponds to the uplink soft handover gain. UL
Q MAX ic BS UL G SHO = -----------------------------------------------UL max Q max k ic BS UL
UL
max Q max k ic BS corresponds to the highest Q max k ic BS value.
4.4.2.4 HSDPA Sub-Menu The HSDPA sub-menu contains HSDPA-related results for HSDPA and HSPA users when the HS-SCCH quality is sufficient and if the user can obtain an HSDPA bearer. Atoll determines the best HSDPA bearer that the user can obtain. The HSDPA bearer user is processed as if he is the only user in the cell, i.e. he uses the entire HSDPA power available in the cell. For further information on the fast link adaptation modelling, see "Fast Link Adaptation Modelling" on page 242. When modelling MC-HSDPA users (including DC-HSDPA users) and DB-MC-HSDPA users, Atoll determines the serving cells and the best HSDPA bearer obtained in each serving cell. In each cell, the user is processed as if he is the only user in the cell. Atoll details the results for each cell to which the user is connected. For further information on MC-HSDPA user modelling, see "MCHSDPA Users" on page 296. For further information on DB-MC-HSDPA user modelling, see "DB-MC-HSDPA Users" on page 296. General Results Atoll displays the name of the cell to which the user is connected, the frequency band used by the transmitter, the selected
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carrier, and the maximum available HSDPA power of the cell. HS-PDSCH Ec/Nt Atoll calculates the best HS-PDSCH quality (HS-PDSCH Ec/Nt). The way of calculating it depends on the selected option in the transmitters global parameters (HSDPA part): CQI based on CPICH quality or CQI based on HS-PDSCH quality. For further details on the HS-PDSCH quality calculation, see either "HS-PDSCH Quality Calculation" on page 244 if the selected option is "CQI based on CPICH quality" or "HS-PDSCH Quality Calculation" on page 249 if the selected option is "CQI based on HS-PDSCH quality". HS-PDSCH Power Atoll calculates the available HS-PDSCH power. For further details on the HS-PDSCH power calculation, see either "HS-PDSCH Quality Calculation" on page 244 if the selected option is "CQI based on CPICH quality" or "HS-PDSCH Quality Calculation" on page 249 if the selected option is "CQI based on HS-PDSCH quality". HS-SCCH Ec/Nt Threshold Atoll displays the HS-SCCH Ec/Nt threshold set for the selected mobility type. HS-SCCH Ec/Nt Atoll displays the obtained HS-SCCH quality. When the HS-SCCH power allocation strategy is dynamic, this parameter corresponds to the HS-SCCH Ec/Nt threshold defined for the selected mobility type. When the HS-SCCH power allocation strategy is static, the HS-SCCH Ec/Nt is calculated from the fixed HS-SCCH power. We have: BTS P c ic Eci ---- ic = ------------------------------- for the total noise option, Nt HS – SCCH DL N tot ic And BTS P c ic Eci ---- = ---------------------------------------------------------------------------------------------------------------------------- for the without useful signal option. Nt ic HS – SCCH DL term N tot ic – 1 – F ortho 1 – F MUD BTS P c ic i
With DL
DL
DL
DL
DL
term
N tot ic = I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0
DL DL DL P SCH ic P SCH ic DL term I intra ic = P tot ic + BTS 1 – F MUD 1 – F ortho P tot ic – ------------------- – BTS P tot ic – ------------------ LT LT txi txi txi DL
I extra ic =
DL
P tot ic
txj j i
Ptot icadj DL
DL
j I inter – carrier ic = txj -----------------------------------RF ic ic adj
icadj is a carrier adjacent to ic. RF ic ic adj is the interference reduction factor, defined between ic and icadj and set to a value different from 0. DL
I inter – techno log y ic is the inter-technology interference at the receiver on ic. DL
I inter – techno log y ic =
n
ic i is the i
th
i
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic i
interfering carrier of an external transmitter
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Tx m
ICP ic ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the i
frequency gap between ic i (external network) and ic . P HS – SCCH ic P c ic = ------------------------------i LT i
And L path L Tx L term L body L indoor M Shadowing – Ec Io L T = -----------------------------------------------------------------------------------------------------------------------------------G Tx G term term
term
BTS , F ortho , F MUD and N 0
are defined in "Inputs" on page 215.
CQI It corresponds to the HS-PDSCH CQI. The way of calculating it depends on the selected option in the transmitters global parameters (HSDPA part): CQI based on CPICH quality or CQI based on HS-PDSCH quality. For further details on the HS-PDSCH quality calculation, see either "HS-PDSCH CQI Determination" on page 246 if the selected option is "CQI based on CPICH quality" or "HS-PDSCH CQI Determination" on page 252 if the selected option is "CQI based on HS-PDSCH quality". HSDPA Bearer Parameters Knowing the HS-PDSCH CQI, Atoll calculates the best HSDPA bearer that can be used and selects a bearer compatible with cell and terminal user equipment HSDPA capabilities. For further details on the HSDPA bearer selection, see "HSDPA Bearer Selection" on page 246. Atoll displays the parameters of the selected HSDPA bearer: • • •
The transport block size, The modulation scheme used, The number of HS-PDSCH channels used.
Peak RLC Throughput DL
Once the bearer selected, Atoll determines the peak RLC throughput that can be provided to the user TP P –R LC . Effective RLC Throughput DL
Atoll displays the Effective RLC throughput ( TP E – RLC ) provided to the user. The Effective RLC throughput is calculated as follows: DL
TP P –RLC DL TP E – RLC = ----------------TTI Where TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user equipment category properties. BLER Atoll reads the BLER in the quality graph BLER = f(HS-PDSCH Ec/Nt) that is defined for the selected bearer and mobility type. Knowing the HS-PDSCH Ec/Nt, it finds the corresponding BLER. Bearer Consumption Atoll provides this result for HSPA CBR service users only. The minimum throughput demand required by the service is allocated to these users. Therefore, they partly consume the HSDPA bearer. The bearer consumption expressed in %, C HSDPABearer , is calculated as follows: TPD Min – DL C HSDPABearer = --------------------------------------------------DL TP P –R LC I HSDPABearer
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MC-HSDPA Users When multi-cell HSDPA is active, MC-HSDPA users can simultaneously connect to several HSDPA cells of the transmitter for data transfer. The maximum number of cells to which the user can simultaneously connect depends on the DL multi-cell mode set for the HSDPA UE category of the terminal. Atoll determines the best serving cell using the best serving cell selection algorithm. For information on how the best serving cell is selected, see "Best Serving Cell and Active Set Determination" on page 284. If the best carrier belongs to a transmitter that supports the multi-cell HSDPA mode and if the transmitter has several HSDPA carriers, Atoll selects the other serving cells, i.e., the secondary cells. The secondary cells belong to the same transmitter and are chosen among the adjacent carriers according to the CQI. When two adjacent carriers are available, Atoll takes the one with the highest CQI value. Atoll selects secondary cells as long as HSDPA carriers are available in the transmitter and the maximum number of cells to which the user can simultaneously connect is not exceeded. In each serving cell (i.e., the best cell and the secondary cells), Atoll determines the best HSDPA bearer obtained. In each cell, the user is processed as if he is the only user in the cell. The user is connected to a cell if he obtains an HSDPA bearer. DB-MC-HSDPA Users When multi-cell HSDPA and dual-band HSDPA modes are active, DB-MC-HSDPA users can simultaneously connect to HSDPA cells of two co-site transmitters using different frequency bands. If the two co-site transmitters work on the same frequency band, then the users can only connect to the HSDPA cells of one transmitter. The maximum number of cells to which the user can simultaneously connect depends on the DL multi-cell mode set for the HSDPA UE category of the terminal. Let’s consider the following configuration: • • • •
A site with transmitters working on two different frequency bands, The site equipment supports the dual-band HSDPA mode, Each transmitter has several HSDPA carriers, The multi-cell HSDPA mode is active for each transmitter.
Atoll determines the best serving cell using the best serving cell selection algorithm. For information on how the best serving cell is selected, see "Best Serving Cell and Active Set Determination" on page 284. The secondary cells are taken in the same band as the best carrier (i.e., they belong to the same transmitter), as long as carriers are available. Then, if additional carriers are required and if there are no more carriers available in this transmitter, Atoll selects the carriers in a transmitter using the second frequency band. Within one frequency band, the secondary cells are first selected according to an adjacency criterion and then, according to the CQI value. When two adjacent carriers are available, Atoll takes the one with the highest CQI value. In each serving cell (i.e., the best cell and the secondary cells), Atoll determines the best HSDPA bearer obtained. In each cell, the user is processed as if he is the only user in the cell. The user is connected to a cell if he obtains an HSDPA bearer. Results for MC-HSDPA and DB-MC-HSDPA Users When the user is simultaneously connected to several HSDPA cells, Atoll details the results for each cell. In addition, it displays the following results under Total: • DL
The Peak RLC Throughput
TP P – RLC =
DL
TP P –RLC c
c Serving cell
•
The Effective RLC Throughput DL
TP P –RLC DL TP E – RLC = ----------------TTI Where TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user equipment category properties. •
The Application Throughput
DL
TP P –RLC c 1 – BLER HSDPA
DL Serving cells - f TP – Scaling – TP Offset TP A = c---------------------------------------------------------------------------------------------------------TTI
Where: BLER HSDPA is read in the quality graph defined for the triplet “reception equipment-selected bearer-mobility” (HSDPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of the measured quality (HS-PDSCH Ec/Nt). Knowing the HS-PDSCH Ec/Nt, Atoll finds the corresponding BLER. TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user equipment category properties.
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f TP – Scaling and TP Offset respectively represent the scaling factor between the application throughput and the RLC (Radio Link Control) throughput and the throughput offset. These two parameters model the header information and other supplementary data that does not appear at the application level. They are defined in the service properties.
4.4.2.5 HSUPA Sub-Menu The HSUPA sub-menu contains HSUPA-related results for HSPA users if the user can obtain an HSUPA bearer. Atoll determines the best HSUPA bearer that the user can obtain. The HSUPA bearer user is processed as if he is the only user in the cell, i.e. he uses the entire remaining load of the cell. For further information on the HSUPA bearer selection, see "HSUPA Bearer Allocation Process" on page 261. Required E-DPDCH Ec/Nt req
Ec It corresponds to the E-DPDCH Ec/Nt required to obtain the HSUPA bearer ( ------ ). This value is defined for an HSUPA Nt E – DPDCH bearer ( Index HSUPABearer ) and a number of retransmissions ( N Rtx ) in the HSUPA Bearer Selection table. Required Terminal Power Ec req req From ------ , Atoll calculates the terminal power required to obtain the HSUPA bearer, P term – HSUPA . Nt E – DPDCH req
Ec req UL P term – HSUPA = ------ L T N tot Nt E – DPDCH With UL
UL intra
tx
N tot ic = 1 – F MUD term I tot
UL
extra
ic + I tot
UL
tx
ic + I inter – carrier ic + N 0
L path L Tx L term L body L indoor M Shadowing – Eb Nt UL L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term tx
UL
intra
term , F MUD , I tot
UL
extra
, I tot
UL
tx
, I inter – carrier and N 0 are defined in "Inputs" on page 215.
Max E-DPDCH Ec/Nt Ec max Atoll calculates the maximum E-DPDCH Ec⁄Nt allowed ( ------ ). For further details on the calculation, see "Max E Nt E – DPDCH DPDCH Ec/Nt" on page 298. HSUPA Bearer Parameters Atoll selects the best HSUPA bearer from the HSUPA compatible bearers. This is the HSUPA bearer with the highest potential UL
TP P – RLC Index HSUPABearer - ) where: throughput ( -----------------------------------------------------------------N Rtx Index HSUPABearer •
Ec req Ec max ---- ------ Nt E – DPDCH Nt E – DPDCH
•
And P term – HSUPA P term
req
max
With max
P term : the maximum terminal power allowed. Atoll displays the parameters of the selected HSUPA bearer: • • • •
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The radio bearer index, The TTI duration, The modulation scheme used, The number of E-DPDCH codes used.
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Peak RLC Throughput UL
After selecting the HSUPA bearer, Atoll determines the corresponding RLC peak throughput, TP P – RLC . Peak RLC Throughput/No. of RTX UL
TPP – RLC Index HSUPABearer Atoll displays the peak RLC throughput to number of retransmissions ratio ( ------------------------------------------------------------------- ). Atoll considers the N Rtx Index HSUPABearer ratio to select the HSUPA bearer when several HSUPA bearers meet the selection criteria. Min Effective RLC Throughput UL
From the RLC peak throughput, Atoll calculates the minimum effective RLC throughput, TP Min – E – RLC . UL
TP P – RLC 1 – BLER HSUPA UL TP Min – E – RLC M b = -----------------------------------------------------------------N Rtx Where: BLER HSUPA is the residual BLER after N Rtx retransmissions. Application Throughput UL
Atoll displays the provided application throughput ( TP A ). The application throughput represents the net throughput after deduction of coding (redundancy, overhead, addressing, etc.). This one is calculated as follows: UL
TP P – RLC 1 – BLER HSUPA f TP – Scaling – TP Offset UL TP A M b = --------------------------------------------------------------------------------------------------------------------------N Rtx BLER Knowing the E-DPDCH Ec/Nt, Atoll finds the corresponding BLER. It is read in the quality graph defined for the quartet “reception equipment-selected bearer-number of retransmissions-mobility” (HSUPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of the measured quality (E-DPDCH Ec/Nt). Bearer Consumption Atoll provides this result for CBR service users only. The minimum bit rate required by the service is allocated to these users. Therefore, they parly consume the HSUPA bearer. The bearer consumption expressed in %, C HSUPABearer , is calculated as follows: TPD min – UL C HSUPABearer = ----------------------------------------------------UL TP P – RLC I HSUPABearer
4.4.3 Coverage Studies Atoll calculates UMTS-specific coverage studies on each pixel where the pilot signal level exceeds the minimum RSCP threshold. Let us assume each pixel on the map corresponds to a probe receiver with a terminal, a mobility type and a service. This receiver does not create any interference. You can make the coverage prediction for a specific carrier, for all carriers, for a specific layer, or for all layers. Coverage predictions are based on parameters that can be either simulation results, or userdefined cell inputs.
4.4.3.1 Pilot Quality Analysis Atoll determines the best serving cell (BS) for each pixel and calculates the pilot quality received with a fixed cell edge Resulting
coverage probability, Q pilot
BS .
Potential serving cells are filtered depending on the prediction definition (selected layers or carriers, layers supported by the service and the terminal, mobility type) and the pilot signal level which must exceed the defined minimum RSCP threshold. For further information on formulas, see "Definitions" on page 214. For information on the best serving cell selection and pilot quality calculation, see "Bar Graph and Pilot Sub-Menu" on page 285.
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Prediction Study Inputs The Pilot Quality Analysis depends on the downlink total transmitted power of cells. This parameter can be either a simulation output, or a user-defined cell input. In the last case, when no value is defined in the Cells table for the total transmitted power, Atoll considers 50% of the maximum power as default value (i.e. 40 dBm if the maximum power is set to 43 dBm).
4.4.3.1.2
Study Display Options Atoll displays the best pilot quality received with a fixed cell edge coverage probability. Single colour Resulting
Atoll displays a coverage if Q pilot
req
req
BS Q pilot . Coverage consists of a single layer with a unique colour. Q pilot is a target
value defined in the Mobility table by the user. Colour per transmitter Resulting
Atoll displays a coverage if Q pilot
req
BS Q pilot . Coverage consists of several independent layers that can be displayed and
hidden on the map. There is a layer per transmitter. Layer colour is the colour assigned to the transmitter of the best serving cell (BS). Colour per mobility In this case, receiver is not completely defined and no mobility is assigned. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userResulting
defined mobility defined in the Mobility Types sub-folder. For each layer, area is covered if Q pilot
req
BS Q pilot .
Colour per probability This display option is available only if analysis is based on all simulations in a group (i.e. if you select a group of simulations and the “All” option in the Condition tab of prediction properties). Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per user-defined probability level defined in the Display tab (Prediction Resulting
properties). For each layer, area is covered if Q pilot
req
BS Q pilot in the required number of simulations.
Colour per cell edge coverage probability Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined cell edge coverage probability, p, defined in the Display tab (Prediction properties). For each layer, area is covered if Resulting
Q pilot
req
BS p Q pilot .
Colour per quality level (Ec/I0) Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined quality threshold defined in the Display tab (Prediction properties). For each layer, area is covered if Resulting
Q pilot
BS Q pilot threshold .
Colour per quality margin (Ec/I0 margin) Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined quality margin defined in the Display tab (Prediction properties). For each layer, area is covered if Resulting
Q pilot
req
BS – Q pilot Q pilot m arg in .
Colour per pilot signal level (Ec) Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined pilot signal level defined in the Display tab (Prediction properties). For each layer, area is covered if Resulting
Q pilot
BS Q pilot threshold .
4.4.3.2 Downlink Service Area Analysis As in point predictions, Atoll calculates traffic channel quality at the receiver for each cell (k,icBS) in the receiver’s active set. No power control is performed as in simulations. Here, Atoll determines downlink traffic channel quality at the receiver for a
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DL
maximum allowed traffic channel power for transmitters. Then, the total downlink traffic channel quality ( Q MAX ic BS ) is evaluated after recombination. Atoll displays the total traffic channel quality in the downlink. For information on best serving cell selection and active set determination, see "Best Serving Cell and Active Set Determination" on page 284. For further details on calculations, see "Downlink R99 Sub-Menu" on page 288.
4.4.3.2.1
Prediction Study Inputs The Downlink Service Area Analysis depends on the downlink total transmitted power of cells. This parameter can be either a simulation output, or a user-defined cell input. In the last case, when no value is defined in the Cells table for the total transmitted power, Atoll considers 50% of the maximum power as default value (i.e. 40 dBm if the maximum power is set to 43 dBm).
4.4.3.2.2
Study Display Options Single colour DL
DL
DL
DL
DL
Atoll displays a coverage with a unique colour if Q MAX ic BS Q req (or Q MAX ic BS Q req Q req if compressed mode is activated). DL
Q req is the downlink traffic quality target defined by the user for a given reception equipment, a given R99 bearer and a given mobility type. This parameter is available in the R99 Bearer Selection table. DL
Q req is the DL Eb/Nt target increase; this parameter is user-defined in the Global parameters. Colour per transmitter DL
DL
DL
DL
DL
Atoll displays a coverage if Q MAX ic BS Q req (or Q MAX ic BS Q req Q req if compressed mode is activated). Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per transmitter. Layer colour is the colour assigned to best serving transmitter. Colour per mobility In this case, receiver is not completely defined and no mobility is assigned. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per user-defined mobility defined in Mobility sub-folder. For DL
DL
DL
DL
DL
each layer, area is covered if Q MAX ic BS Q req (or Q MAX ic BS Q req Q req if compressed mode is activated). Colour per service In this case, receiver is not completely defined and no service is assigned. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per user-defined service defined in Services sub-folder. For each DL
DL
DL
DL
DL
layer, area is covered if Q MAX ic BS Q req (or Q MAX ic BS Q req Q req if compressed mode is activated). Colour per probability This display option is available only if analysis is based on all simulations in a group (i.e. if you select a group of simulations and the “All” option in the Condition tab of prediction properties). Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per user-defined probability level defined in the Display tab (Prediction DL
DL
properties). For each layer, area is covered if Q MAX ic BS Q req in the required number of simulations. Colour per cell edge coverage probability Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined cell edge coverage probability, p, defined in the Display tab (Prediction properties). For each layer, area is covered if DL
DL
DL
DL
DL
Q MAX ic BS p Q req (or Q MAX ic BS Q req Q req if compressed mode is activated). Colour per maximum quality level (max Eb/Nt) Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined quality threshold defined in the Display tab (Prediction properties). For each layer, area is covered if DL
Q MAX ic BS Threshold .
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Colour per effective quality level (Effective Eb/Nt) Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined quality threshold defined in the Display tab (Prediction properties). For each layer, area is covered if DL
Q eff ic BS Threshold .
DL
DL
DL
Q eff ic BS = min Q MAX ic BS Q req
(or
DL
DL
DL
DL
Q eff ic BS = min Q MAX ic BS Q req Q req
when compressed mode is activated). Colour per quality margin (Eb/Nt margin) Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined quality margin defined in the Display tab (Prediction properties). For each layer, area is covered if DL
DL
DL
DL
DL
Q MAX ic BS – Q req M arg in (or Q MAX ic BS – Q req Q req M arg in when compressed mode is activated). Colour per required power req
Atoll calculates the downlink required power, P tch ic BS , as follows: DL
Q req req - P max P tch ic BS = -------------------------tch DL Q MAX ic BS Where DL
Q req is the Eb/Nt target on downlink. This parameter, available in the R99 Bearer Selection table, is user-defined for a given R99 bearer, a given reception equipment and a mobility type. max
P tch is a user-defined input for each bearer related to a service. It corresponds to the maximum allowable traffic channel power for a transmitter. DL
DL
Q req Q req req - P max When compressed mode is activated, we have: P tch ic BS = -----------------------------tch . DL Q MAX ic BS Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined required power threshold defined in the Display tab (Prediction properties). For each layer, area is covered if req
P tch ic BS Threshold . Colour per required power margin Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined power margin defined in the Display tab (Prediction properties). For each layer, area is covered if req
max
P tch ic BS – P tch M arg in .
4.4.3.3 Uplink Service Area Analysis As in point prediction, Atoll calculates uplink traffic channel quality from the receiver for each cell (k,icBS) in receiver active set. No power control simulation is performed. Atoll determines uplink traffic channel quality at the transmitter for the UL
maximum terminal power allowed. Then, the total uplink traffic channel quality ( Q MAX ic BS ) is evaluated with respect to receiver handover status. Atoll displays the total traffic channel quality in the uplink. For information on best serving cell selection and active set determination, see "Best Serving Cell and Active Set Determination" on page 284. For further details on calculations, see "Uplink R99 Sub-Menu" on page 291.
4.4.3.3.1
Prediction Study Inputs The Uplink Service Area Analysis depends on the UL load factor of cells. This parameter can be either a simulation output, or a user-defined cell input. In the last case, when no value is defined in the Cells table for the uplink load factor, Atoll uses 50% as default value.
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Study Display Options Single colour UL
UL
UL
UL
UL
Atoll displays a coverage if Q MAX ic BS Q req (or Q MAX ic BS Q req Q req if compressed mode is activated). Coverage colour is unique. UL
Q req is defined for a reception equipment, a R99 bearer and a mobility type. This parameter is available in the R99 Bearer Selection table. UL
Q req is the UL Eb/Nt target increase; this parameter is user-defined in the Global parameters. Colour per transmitter UL
UL
UL
UL
UL
Atoll displays a coverage if Q MAX ic BS Q req (or Q MAX ic BS Q req Q req if compressed mode is activated). Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per transmitter. Layer colour is the colour assigned to best server transmitter. Colour per mobility In this case, receiver is not completely defined and no mobility is assigned. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per user-defined mobility defined in Mobility sub-folder. For UL
UL
UL
UL
UL
each layer, area is covered if Q MAX ic BS Q req (or Q MAX ic BS Q req Q req if compressed mode is activated). Colour per service In this case, receiver is not completely defined and no service is assigned. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per user-defined service defined in Services sub-folder. For each UL
UL
UL
UL
UL
layer, area is covered if Q MAX ic BS Q req (or Q MAX ic BS Q req Q req if compressed mode is activated). Colour per probability This display option is available only if analysis is based on all simulations in a group (i.e. if you select a group of simulations and the “All” option in the Condition tab of prediction properties). Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per user-defined probability level defined in the Display tab (Prediction UL
UL
UL
UL
UL
properties). For each layer, area is covered if Q MAX ic BS Q req (or Q MAX ic BS Q req Q req if compressed mode is activated) in the required number of simulations. Colour per maximum quality level (Max Eb/Nt) Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined quality threshold defined in the Display tab (Prediction properties). For each layer, area is covered if UL
Q MAX ic BS Threshold . Colour per effective quality level (Effective Eb/Nt) Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined quality threshold defined in the Display tab (Prediction properties). For each layer, area is covered if UL
Q effective ic BS Threshold . UL
UL
UL
Q eff ic BS = min Q MAX ic BS Q req
(or
UL
UL
UL
UL
Q eff ic BS = min Q MAX ic BS Q req Q req
when compressed mode is
activated). Colour per quality margin (Eb/Nt margin) Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined quality margin defined in the Display tab (Prediction properties). For each layer, area is covered if UL
UL
UL
UL
UL
Q MAX ic BS – Q req M arg in (or Q MAX ic BS – Q req Q req M arg in if compressed mode is activated).
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Colour per required power Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined power threshold defined in the Display tab (Prediction properties). For each layer, area is covered if req
P term – R99 ic BS Threshold . Colour per required power margin Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined power margin defined in the Display tab (Prediction properties). For each layer, area is covered if req
max
P term – R99 ic BS – P term M arg in . Colour per soft handover gain Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per soft UL
handover gain value defined in the Display tab (Prediction properties). For each layer, area is covered if G SHO Threshold .
4.4.3.4 Downlink Total Noise Analysis Atoll determines the downlink total noise level generated by cells. You can make the coverage prediction for a specific carrier, for all carriers, for a specific layer, or for all layers. We assume that each pixel on the map corresponds to a probe receiver with a terminal, a mobility type and a service. When you select "Best (All/Specific band)" as the carrier or layers associated with several carriers, Atoll determines the DL total noise level on each carrier supported by the user service. When only one carrier is analysed, Atoll determines DL total noise or DL noise rise on this carrier.
Ptot icadj DL
DL
N tot ic =
txj j
DL
txj j P tot ic + -----------------------------------+ RF ic ic adj
ni
Tx
P Transmitted ic i term -------------------------------------- + N 0 Tx Tx m L total ICP ic ic i
DL
Downlink noise rise, NR DL ic , is calculated from the downlink total noise, N tot , as follows: term
N0 - NR DL ic = – 10 log ----------- N DL tot
4.4.3.4.1
Study Inputs The Downlink Total Noise Analysis depends on the downlink total transmitted power of cells. This parameter can be either a simulation output, or a user-defined cell input. In the last case, when no value is defined in the Cells table for the total transmitted power, Atoll considers 50% of the maximum power as default value (i.e. 40 dBm if the maximum power is set to 43 dBm).
4.4.3.4.2
Display Options The following display options are available for the prediction: Colour per minimum noise level Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined noise level defined in the Display tab (Prediction properties). For each layer, area is covered if DL
minN tot ic Threshold . ic
Colour per maximum noise level Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined noise level defined in the Display tab (Prediction properties). For each layer, area is covered if DL
maxN tot ic Threshold . ic
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Colour per average noise level Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined noise level defined in the Display tab (Prediction properties). For each layer, area is covered if DL
averageNtot ic Threshold . ic
Colour per minimum noise rise Atoll displays bins where minNR DL ic Threshold . Coverage consists of several independent layers that can be displayed ic
and hidden on the map. There is a layer per user-defined noise rise threshold defined in the Display tab. Colour per maximum noise rise Atoll displays bins where maxNR DL ic Threshold . Coverage consists of several independent layers that can be displayed ic
and hidden on the map. There is a layer per user-defined noise rise threshold defined in the Display tab. Colour per average noise rise Atoll displays bins where averageNR DL ic Threshold . Coverage consists of several independent layers that can be ic
displayed and hidden on the map. There is a layer per user-defined noise rise threshold defined in the Display tab. When only one carrier is analysed, Atoll determines DL total noise or DL noise rise on this carrier. In this case, the displayed coverage is the same for any selected display option (average, minimum, maximum).
4.4.3.5 HSDPA Prediction Study When calculating the HSDPA coverage prediction, either you can take all the possible HSDPA radio bearers into consideration, or you can study a certain HSDPA radio bearer. Then, available display options depend on what you have selected. When considering all the HSDPA radio bearers, you can set display parameters: • • •
To analyse the uplink and downlink A-DPCH qualities on the map, To analyse the HS-SCCH quality/power, To model fast link adaptation for a single HSDPA bearer user or for a defined number of HSDPA bearer users.
When studying a certain HSDPA radio bearer, you can display areas where a certain RLC peak throughput is available with different cell edge coverage probabilities (i.e. the probability of having a certain RLC peak throughput). This type of analysis is not relevant when modelling MC-HSDPA and DB-MC-HSDPA users. Here we assume that each pixel on the map corresponds to one or several users with HSDPA capable terminal, mobility and HSDPA service.The user does not create any interference. You can make the coverage prediction for a specific carrier, for all carriers, for a specific layer, or for all layers. For DC-HSDPA, MC-HSDPA and DB-MC-HSDPA users, selecting one specific carrier or one layer associated with one unique carrier is not suitable. To display the global throughput, you have to select several carriers ("Best HSPA (All/Specific band)" as the carrier) or layers associated with several carriers. For information on the best serving cell and secondary cells selection, see "MC-HSDPA Users" on page 296 and "DB-MCHSDPA Users" on page 296. Note that the HSDPA service area is limited by the pilot quality, the A-DPCH quality and the HS-SCCH quality.
4.4.3.5.1
Prediction Study Inputs Parameters used as input for the HSDPA prediction study are: • • •
The available HSDPA power of the cell, The downlink total transmitted power of the cell, The number of HSDPA bearer users within the cell if the study is calculated for several users.
These parameters can be either simulation outputs, or user-defined cell inputs. In the last case, when no value is defined in the Cells table for the total transmitted power and the number of HSDPA bearer users, Atoll uses the following default values: • •
Total transmitted power = 50% of the maximum power (i.e, 40 dBm if the maximum power is set to 43 dBm) Number of HSDPA bearer users = 1
On the other hand, no default value is used for the available HSDPA power; this parameter must be defined by the user.
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Study Display Options When considering all the HSDPA radio bearers, several display options are available in the study properties dialogue. They can be regrouped in four categories according to the objective of the study: • • • •
To analyse the uplink and downlink A-DPCH qualities on the map, To analyse the HS-SCCH quality/power, To model fast link adaptation for a single HSDPA bearer user, To model fast link adaptation for a defined number of HSDPA bearer users.
When studying a certain HSDPA radio bearer, only one display option is available. It allows you to display where a certain RLC peak throughput is available with different cell edge coverage probabilities. Analysis of UL And DL A-DPCH Qualities •
Colour per Max A-DPCH Eb/Nt DL DL
Atoll displays the A-DPCH quality at the receiver ( Q MAX BS ) for the best serving cell (BS). No power control is performed as in simulations. Here, Atoll determines downlink traffic channel quality at the receiver for a maximum traffic channel power allowed for the best serving cell. For information on calculation methods, see "Downlink R99 Sub-Menu" on page 288. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined quality threshold defined in the Display tab (Prediction properties). For each layer, area is covered if DL
Q MAX BS Threshold . •
Colour per Max A-DPCH Eb/Nt UL UL
Atoll displays the A-DPCH quality at the best serving cell ( Q MAX BS ). No power control is performed as in simulations. Here, Atoll determines uplink traffic channel quality at the receiver for a maximum terminal power allowed. For information on calculation methods, see "Uplink R99 Sub-Menu" on page 291. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per userdefined quality threshold defined in the Display tab (Prediction properties). For each layer, area is covered if UL
Q MAX BS Threshold . Analysis of The HS-SCCH Quality/Power •
Colour per HS-SCCH Power
This display option is relevant in case of dynamic HS-SCCH power allocation only. In this case, Atoll displays on each pixel the HS-SCCH power per HS-SCCH channel. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per threshold. For each layer, area is covered if P HS – SCCH BS Threshold . •
Colour per HS-SCCH Ec/Nt
This display option is relevant in case of static HS-SCCH power allocation only. In this case, Atoll displays on each pixel the HSSCCH quality per HS-SCCH channel. Coverage consists of several independent layers that can be displayed and hidden on the Ec map. There is a layer per threshold. For each layer, area is covered if ------ BS . Nt HS – SCCH Threshold Fast Link Adaptation Modelling For A Single User When you calculate the study with the following display options, Atoll considers one user on each pixel and determines the best HSDPA bearer that the user can obtain. For MC-HSDPA and DB-MC-HSDPA users, Atoll determines the best HSDPA bearers that the user can obtain in each serving cell. On each pixel, the user is processed as if he is the only user in the cell i.e. he uses the entire HSDPA power available in the cell. For further information on the fast link adaptation modelling, see "Fast Link Adaptation Modelling" on page 242. •
Colour per HS-PDSCH Ec/Nt
Atoll displays on each pixel the HS-PDSCH quality. For MC-HSDPA and DB-MC-HSDPA users, it corresponds to the HS-PDSCH Ec/Nt of the best serving cell. Coverage consists of several independent layers that can be displayed and hidden on the map. Ec There is a layer per threshold. For each layer, area is covered if ------ BS . Nt HS – PDSCH Threshold •
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Atoll displays either the CPICH CQI (see the calculation detail in "CPICH CQI Determination" on page 244) when the selected option in Global parameters (HSDPA part) is CQI based on CPICH quality, or the HS-PDSCH CQI (see the calculation detail in the section 10.7.1.2.2) when considering the CQI based on HS-PDSCH quality option. For MC-HSDPA and DB-MC-HSDPA users, it corresponds to the CQI of the best serving cell. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per CQI threshold ( CQI threshold ). For each layer, area is covered if CQI CQI threshold . •
Colour per Peak MAC Throughput DL
Atoll displays the Peak MAC throughput ( TPP –M AC ) provided on each pixel. The Peak MAC throughput is calculated as follows: DL
TP P – M AC =
c Serving cells
S block c --------------------T TTI
Where, S block c is the transport block size (in kbits) of the HSDPA bearer selected in the cell, c, for the user; it is defined for each HSDPA bearer in the HSDPA Radio Bearers table. –3
T TTI is the TTI duration, i.e. 2 10 s (2000 TTI in one second). This value is specified by the 3GPP. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible DL
Peak MAC throughput ( TPP –M AC ). For each layer, area is covered if the Peak MAC throughput exceeds the user-defined thresholds. •
Colour per Effective MAC Throughput DL
Atoll displays the Effective MAC throughput ( TP E – M AC ) provided on each pixel. The Effective MAC throughput is calculated as follows: DL
TP E – M AC =
c Serving cells
S block c -------------------------T TTI TTI
Where, S block c is the transport block size (in kbits) of the selected HSDPA bearer in the cell, c; it is defined for each HSDPA bearer in the HSDPA Radio Bearers table. TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user equipment category properties. –3
T TTI is the TTI duration, i.e. 2 10 s (2000 TTI in one second). This value is specified by the 3GPP. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible DL
Effective MAC throughput ( TP E – M AC ). For each layer, area is covered if the Effective MAC throughput exceeds the userdefined thresholds. •
Colour per Peak RLC Throughput
After selecting the bearer, Atoll reads the corresponding RLC peak throughput ( TP DL I ). This is the highest P – RLC HSDPABearer throughput that the bearer can provide on each pixel. Then, it determines the peak RLC throughput provided by the serving DL
cell, c, in the downlink, TP P – RLC c . DL
DL
For an HSDPA user, we have: TP P – RLC = TP P –RLC c For MC-HSDPA and DB-MC-HSDPA users, the peak RLC throughput provided to the user is calculated as follows: DL
TP P – RLC =
DL
TP P –RLC c
c Serving cell
Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible DL
RLC peak throughput ( TP P – RLC ). For each layer, area is covered if the peak RLC throughput can be provided. •
Colour per Effective RLC Throughput
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Atoll displays the Effective RLC throughput ( TP E – RLC ) provided on each pixel. The Effective RLC throughput is calculated as follows: DL
TP P –RLC DL TP E – RLC = ----------------TTI Where TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user equipment category properties. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible DL
Effective RLC throughput ( TP E – RLC ). For each layer, area is covered if the Effective RLC throughput exceeds the user-defined thresholds. •
Colour per Average Effective RLC Throughput DL
Atoll displays the average effective RLC throughput ( TP Av – E – RLC ) provided on each pixel. For an HSDPA user, we have: DL
TP P –RLC c 1 – BLER HSDPA DL TP Av –E –RLC = -----------------------------------------------------------------------TTI For MC-HSDPA and DB-MC-HSDPA users, we have:
DL
DL
TP P –RLC c 1 – BLER HSDPA
Serving cells TP Av –E –RLC = c---------------------------------------------------------------------------------------------------------TTI
Where, BLER HSDPA is read in the quality graph defined for the triplet “reception equipment-selected bearer-mobility” (HSDPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of the measured quality (HS-PDSCH Ec/Nt). Knowing the HS-PDSCH Ec/Nt, Atoll finds the corresponding BLER. TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user equipment category properties. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible DL
average effective RLC throughput ( TP Av –E –RLC ). For each layer, area is covered if the average effective RLC throughput exceeds the user-defined thresholds. •
Colour per Application Throughput DL
Atoll displays the application throughput ( TP A ) provided on each pixel. The application throughput represents the net throughput after deduction of coding (redundancy, overhead, addressing, etc.). It is calculated as follows: DL
DL
TP A = TP Av –E – RLC f TP – Scaling – TP Offset Where: DL
TP Av –E –RLC is the average effective RLC throughput. BLER HSDPA is read in the quality graph defined for the triplet “reception equipment-selected bearer-mobility” (HSDPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of the measured quality (HS-PDSCH Ec/Nt). Knowing the HS-PDSCH Ec/Nt, Atoll finds the corresponding BLER. f TP – Scaling and TP Offset respectively represent the scaling factor between the application throughput and the RLC (Radio Link Control) throughput and the throughput offset. These two parameters model the header information and other supplementary data that does not appear at the application level. They are defined in the service properties. TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user equipment category properties. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible DL
application throughput ( TPA ). For each layer, area is covered if the application throughput exceeds the user-defined thresholds.
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Fast Link Adaptation Modelling For Several Users When you calculate the study with the following display options, Atoll considers several users per pixel and determines the best HSDPA bearer that each user can obtain. In this case, the cell available HSDPA power is shared between HSDPA bearer users. When the coverage prediction is not based on a simulation, the number of HSDPA bearer users is taken from the cell properties. The displayed results of the coverage prediction will be an average result for one user. For further information on the HSDPA bearer allocation process when there are several users, see "HSDPA Bearer Allocation Process" on page 239 For further information on the fast link adaptation modelling, see "Fast Link Adaptation Modelling" on page 242. •
Colour per Effective MAC Throughput per User DL
Atoll displays the average Effective MAC throughput per user ( TP E –M AC Av ) provided on each pixel. The average Effective MAC throughput per user is calculated as follows: n HSDPA
DL
TP E –M AC x
DL
x=1 TP E –M AC Av = ---------------------------------------------Max n HSDPA c c Serving cells x
Where, n HSDPA c is the number of HSDPA bearer users within the cell, c. DL
TP E – M AC x is the Effective MAC throughput of each HSDPA bearer user. For further information on the calculation of the Effective MAC throughput, see "Colour per Effective MAC Throughput" on page 306. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible DL
average Effective MAC throughput per user ( TP E –M AC Av ). For each layer, area is covered if the average Effective MAC throughput per user exceeds the user-defined thresholds. •
Colour per RLC Throughput per User DL
Atoll displays the average effective RLC throughput per user ( TP E –R LC Av ) provided on each pixel. The average effective RLC throughput per user is calculated as follows: n
HSDPA
DL
TP E –R LC x
DL
x=1 TP E –R LC Av = ----------------------------------------n HSDPA
Where, n HSDPA is the number of HSDPA bearer users within the cell. DL
TP E – R LC x is the Effective RLC throughput of each HSDPA bearer user. For further information on the calculation of the Effective RLC throughput, see "Colour per Effective RLC Throughput" on page 307. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible DL
average effective RLC throughput per user ( TP E –R LC Av ). For each layer, area is covered if the average effective RLC throughput per user exceeds the user-defined thresholds. •
Colour per ApplicationThroughput per User DL
Atoll displays the average application throughput per user ( TPA Av ) provided on each pixel. The average application throughput per user is calculated as follows: n HSDPA
DL
TP A x
DL
x=1 TP A Av = ---------------------------------n HSDPA
Where, n HSDPA is the number of HSDPA bearer users within the cell.
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DL
TP A x is the application throughput of each HSDPA bearer user. For further information on the calculation of the application throughput, see "Colour per Application Throughput" on page 308. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible DL
average application throughput per user ( TP A Av ). For each layer, area is covered if the average application throughput per user exceeds the user-defined thresholds. Probability of Having a Certain Peak RLC Throughput This result can be obtained only if you have selected an HSDPA radio bearer in the Condition tab. •
Colour per Cell Edge Coverage Probability
Atoll shows areas where the selected HSDPA radio bearer is available with different cell edge coverage probabilities. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per cell edge coverage probability defined in the Display tab. For each layer, area is covered if the selected HSDPA radio bearer is available.
4.4.3.6 HSUPA Prediction Study A dedicated HSUPA study is available with different calculation and display options. Atoll determines on each pixel the best HSUPA bearer that can be obtained; it can consider either a single HSPA user or several ones on each pixel. For further information on the HSUPA bearer selection, see "HSUPA Bearer Allocation Process" on page 261. By calculating this study with suitable display options, it is possible: • • •
To analyse the power required by the selected terminal, To analyse the required E-DPDCH quality, To analyse peak and effective throughputs.
We assume that each pixel on the map corresponds to one or several users with HSUPA capable terminal, mobility and HSUPA service. You can make the coverage prediction for a specific carrier, for all carriers, for a specific layer, or for all layers. The user does not create any interference. Note that the HSUPA service area is limited by the pilot quality and the A-DPCH-EDPCCH quality.
4.4.3.6.1
Prediction Study Inputs Parameters used as input for the HSUPA prediction study are: • • • • •
The cell UL load factor, The cell UL reuse factor, The cell UL load factor due to HSUPA, The maximum cell UL load factor, The number of HSUPA bearer users within the cell if the study is calculated for several users.
These parameters can be either simulation outputs, or user-defined cell inputs. In the last case, When no value is defined in the Cells table, Atoll uses the following default values: • • • • •
4.4.3.6.2
Uplink load factor = 50% Uplink reuse factor = 1 Uplink load factor due to HSUPA = 0% Maximum uplink load factor = 75% Number of HSUPA beare users = 1
Calculation Options Atoll can calculate the HSUPA coverage prediction in one of two ways: • •
4.4.3.6.3
HSUPA resources can be dedictated to a single user: On each pixel, the user is processed as if he is the only user in the cell i.e he will use the entire remaining load after allocating capacity to all R99 users. HSUPA resources can be shared by HSUPA users defined or calculated per cell: Atoll considers several HSUPA bearer users per pixel. After allocating capacity to all R99 users, the remaining load of the cell will be shared equally between all the HSUPA bearer users. When the coverage prediction is not based on a simulation, the number of HSUPA bearer users is taken from the cell properties. The displayed results of the coverage prediction will be an average result for one user.
Display Options The following display options are available in the prediction property dialogue.
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Colour per Required E-DPDCH Ec/Nt Atoll displays on each pixel the E-DPDCH Ec/Nt required to obtain the selected HSUPA bearer. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per threshold. For each layer, area is covered Ec req Threshold . if ------ Nt E – DPDCH Colour per Required Terminal Power Atoll displays on each pixel the terminal power required to obtain the selected HSUPA bearer. The required terminal power is calculated from the required E-DPDCH Ec/Nt. Coverage consists of several independent layers that can be displayed and req
hidden on the map. There is a layer per threshold. For each layer, area is covered if P term Threshold . Colour per Peak MAC Throughput UL
Atoll displays the Peak MAC throughput ( TPP –M AC ) provided on each pixel. The Peak MAC throughput is calculated as follows: UL
S block UL TP P – M AC = -----------T TTI Where, UL
S block is the transport block size (in kbits) for the selected HSUPA bearer; it is defined for each HSUPA bearer in the HSUPA Radio Bearers table. T TTI is the duration of one TTI for the selected HSUPA bearer; it is defined for each HSUPA bearer in the HSUPA Radio Bearers table. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible UL
Peak MAC throughput ( TPP –M AC ). For each layer, area is covered if the Peak MAC throughput exceeds the user-defined thresholds. Colour per Peak RLC Throughput After selecting the HSUPA bearer, Atoll reads the corresponding RLC peak throughput. This is the highest throughput that the selected HSUPA bearer can provide on each pixel. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible UL
RLC peak throughput ( TP P – RLC ). For each layer, area is covered if the peak RLC throughput can be provided. Colour per Minimum Effective RLC Throughput UL
Atoll displays the minimum effective RLC throughput ( TP Min – E – RLC ) provided on each pixel. The minimum effective RLC throughput corresponds to the RLC throughput obtained for a given BLER and the maximum number of retransmissions. It is calculated as follows: UL
TP P – RLC 1 – BLER HSUPA UL TP Min – E – RLC = ---------------------------------------------------------------N Rtx Where, BLER HSUPA is the residual BLER for the selected uplink transmission format (HSUPA bearer with N Rtx retransmissions). It is read in the quality graph defined for the quartet “reception equipment-selected bearer-number of retransmissions-mobility” (HSUPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of the measured quality (E-DPDCH Ec/Nt). Knowing the E-DPDCH Ec/Nt, Atoll finds the corresponding BLER. N Rtx is the maximum number of retransmissions for the selected HSUPA bearer. This figure is read in the HSUPA Bearer Selection table. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible UL
minimum effective RLC throughput ( TP Min – E –RLC ). For each layer, area is covered if the minimum effective RLC throughput exceeds the user-defined thresholds.
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Colour per Average Effective RLC Throughput When HARQ (Hybrid Automatic Repeat Request) is used, the required average number of retransmissions is smaller and the UL
Effective RLC throughput is an average effective RLC throughput ( TP Av –E –RL C ). This is the RLC throughput obtained for a given BLER and the average number of retransmissions. It is calculated as follows: UL
TP P –RLC 1 – BLER HSUPA UL TP Av –E –RL C = --------------------------------------------------------------- N Rtx av BLER HSUPA is the residual BLER for the selected uplink transmission format (HSUPA bearer with N Rtx retransmissions). It is read in the quality graph defined for the quartet “reception equipment-selected bearer-number of retransmissions-mobility” (HSUPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of the measured quality (E-DPDCH Ec/Nt). Knowing the E-DPDCH Ec/Nt, Atoll finds the corresponding BLER. The average number of retransmissions ( N Rtx av ) is determined from early termination probabilities defined for the selected HSUPA bearer (in the HSUPA Bearer Selection table). The Early Termination Probability graph shows the probability of early termination ( p ) as a function of the number of retransmissions ( N Rtx ). Atoll calculates the average number of retransmissions ( N Rtx av ) as follows: N
Rtx max
N
p N Rtx – p N Rtx – 1 N Rtx
=1
Rtx N Rtx av = ----------------------------------------------------------------------------------------------p N Rtx max
Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible UL
average effective RLC throughput ( TP Av – E – RL C ). For each layer, area is covered if the minimum effective RLC throughput exceeds the user-defined thresholds. Colour per Application Throughput UL
Atoll displays the application throughput ( TP A ) provided on each pixel. The application throughput represents the net throughput after deduction of coding (redundancy, overhead, addressing, etc.). This one is calculated as follows: UL
UL
TP A M b = TP Min – E –RLC f TP – Scaling – TP Offset Where: f TP – Scaling and TP Offset respectively represent the scaling factor between the application throughput and the minimum RLC (Radio Link Control) throughput and the throughput offset. These two parameters model the header information and other supplementary data that does not appear at the application level. They are defined in the service properties. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible UL
application throughput ( TP A ). For each layer, area is covered if the application throughput exceeds the user-defined thresholds. Colour per Average Application Throughput UL
Atoll displays the average application throughput ( TP Av – A ) provided on each pixel. It is calculated as follows: UL
UL
TP Av – A M b = TP Av –E –RL C f TP – Scaling – TP Offset Where: f TP – Scaling and TP Offset respectively represent the scaling factor between the average application throughput and the average RLC (Radio Link Control) throughput and the throughput offset. These two parameters model the header information and other supplementary data that does not appear at the application level. They are defined in the service properties. Coverage consists of several independent layers that can be displayed and hidden on the map. There is a layer per possible UL
average application throughput ( TP Av – A ). For each layer, area is covered if the average application throughput exceeds the user-defined thresholds.
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4.5 Automatic Neighbour Allocation Atoll permits the automatic allocation of intra-technology neighbours in the current network. Two allocation algorithms are available, one dedicated to intra-carrier neighbours and the other for inter-carrier neighbours. The intra-technology neighbour allocation algorithms take into account all the cells of TBC transmitters. It means that all the cells of TBC transmitters of your .atl document are potential neighbours. The cells to be allocated will be called TBA cells. They must fulfil following conditions: • • • •
They are active, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone, They belong to the folder on which allocation has been executed. This folder can be either the Transmitters folder or a group of transmitters or a single transmitter.
Only TBA cells may be assigned neighbours. If no focus zone exists in the .atl document, Atoll takes into account the computation zone.
In this section, the following are explained: • • •
"Neighbour Allocation for All Transmitters" on page 312. "Neighbour Allocation for a Group of Transmitters or One Transmitter" on page 316. "Importance Calculation" on page 316.
4.5.1 Neighbour Allocation for All Transmitters We assume that we have a reference, cell A, and a candidate neighbour, cell B. When the automatic neighbour allocation starts, Atoll checks the following conditions: •
The distance between both cells must be less than the user-definable maximum inter-site distance. If the distance between the reference cell and the candidate neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance, which corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 319.
•
The calculation options: • Carriers: This option enables you to select the carrier(s) on which you want to run the allocation. You may choose one or more carriers. Atoll will allocate neighbours only to the cells using the selected carriers. For inter-carrier neighbours, in addition to the carrier(s) on which you want to run the allocation, you can select the carrier(s) of potential neighbours. •
•
Force co-site cells as neighbours: This option enables you to force cells located on the reference cell site in the candidate neighbour list. This constraint can be weighted among the others and ranks the neighbours through the importance field (see after). Force adjacent cells as neighbours (only for intra-carrier neighbours): This option enables you to force cells geographically adjacent to the reference cell in the candidate neighbour list. This constraint can be weighted among the others and ranks the neighbours through the importance field (see below).
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Adjacency criterion: Let CellA be a candidate neighbour cell of CellB. CellA is considered adjacent to CellB if there exists at least one pixel in the CellB Best Server coverage area where CellA is Best Server (if several cells have the same best server value) or CellA is the second best server that enters the Active Set (respecting the HO margin of the allocation).
When Force adjacent cells as neighbours is selected, adjacent cells are sorted and listed from the most adjacent to the least adjacent, depending on the above criterion. Adjacency is relative to the number of pixels satisfying the criterion. •
•
Force adjacent layers as neighbours: If selected, Atoll adds all the cells adjacent across network layers to the reference cell to the candidate neighbour list. The weight of this constraint is always the average of the Min and Max values defined for the adjacency factor. This weight is used to calculate the rank of each neighbour and its importance. Cells are considered adjacent across layers if they belong to different layers and have a coverage overlap of at least one pixel. Force symmetry: This option enables user to force the reciprocity of a neighbourhood link. Therefore, if the reference cell is a candidate neighbour of another cell, this one will be considered as candidate neighbour of the reference cell. If the neighbours list of a cell is full, the reference cell will not be added as a neighbour of that cell and that cell will be removed from the reference cell’s neighbours list. You can force Atoll to keep that cell in the reference cell’s neighbours list by adding the following option in the Atoll.ini file: [Neighbours] DoNotDeleteSymmetrics = 1
•
•
Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may force/forbid a cell to be candidate neighbour of the reference cell.
•
Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, the existing neighbours are kept.
If the Use Coverage Conditions check box is selected, there must be an overlapping zone ( S A S B ) with a given cell edge coverage probability. Otherwise, only the distance criterion is taken into account.
The overlapping zone ( S A S B ) is defined as follows: •
Intra-carrier neighbours: intra-carrier handover is a soft handover.
The reference cell A and the candidate cell B are using the carrier c1 (c1 is the selected carrier on which you run the allocation). SA is the area where the cell A is the best serving cell. It means that the cell A is the first one in the active set. • •
The pilot signal level received from A is greater than the minimum pilot signal level (min RSCP). The best server indicator of A ( I BS A ) exceeds the minimum pilot quality (min Ec/I0).
•
I BS A is the highest one.
For information on the best server indicator calculation, see "Best Serving Cell Determination in Monte Carlo Simulations - Old Method" on page 283.
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SB is the area where the cell B can enter the active set. • •
The pilot signal received from the cell B is greater than the minimum pilot signal level (min RSCP). The pilot quality from B is greater than the pilot quality from A minus the Ec/I0 margin (AS Threshold).
Figure 4.16: Overlapping Zone for Intra-carrier Neighbours •
Inter-carrier neighbours: inter-frequency handover is a hard handover, triggered in multi-carrier W-CDMA networks for coverage reasons (1st case) and to balance the load between carriers (2nd case).
The reference cell A is using the carrier c1 (c1 is the carrier selected in Source) and the candidate cell B is using the carrier c2 (c2 is the carrier selected in Destination). SA is the area where the reference cell A is either the best serving cell among all cells using c1 (1st case) or a cell that can enter the active set of a user connected to c1 (2nd case). •
•
1st case: The cell A is the best serving cell among all cells using c1 but its pilot quality starts significantly decreasing. • •
The pilot signal level received from A is greater than the minimum pilot signal level (min RSCP). The best server indicator of A ( I BS A ) is the highest one.
•
I BS A is lower than the minimum pilot quality (min Ec/I0) plus the handover margin.
2nd case: The cell A is not the best serving cell among all cells using c1 but it can enter the active set of a user connected to c1. • • •
The pilot signal level received from A is greater than the minimum pilot signal level (min RSCP). The best server indicator of A ( I BS A ) exceeds the minimum pilot quality (min Ec/I0). I BS A is not the highest one. It is strictly lower than the best server indicator of the best serving cell and greater than the best server indicator of the best serving cell minus the handover margin.
SB is the area where the cell B is the best serving cell among all cells using c2. • •
The pilot signal level received from B is greater than the minimum pilot signal level (min RSCP). The best server indicator of B ( I BS B ) exceeds the minimum pilot quality (min Ec/I0).
•
I BS B is the highest one.
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Figure 4.17: Overlapping Zone for Inter-carrier Neighbours - 1st case
Figure 4.18: Overlapping Zone for Inter-carrier Neighbours - 1st Case For information on the best server indicator calculation, see "Best Serving Cell Determination in Monte Carlo Simulations - Old Method" on page 283. •
Two ways enable you to determine the I0 value: 1. Global Value: A percentage of the cell maximum power is considered. If the % of maximum power is too low, i.e. if % Pmax P pilot , Atoll takes into account the pilot power of the cell. Then, I0 represents the sum of values calculated for each cell. 2. Defined per Cell: Atoll takes into account the total downlink power defined per cell. I0 represents the sum of total transmitted powers.
•
For calculating the overlapping coverage areas, Atoll uses the service with the lowest body loss, the terminal that has the highest difference between gain and losses or the lowest noise figure when all terminals have the same (gain-losses) value, and the shadowing margin calculated using the defined cell edge coverage probability, if the option is selected. The service and terminal are selected such that the selection gives the largest possible coverage areas for the cells.
SA SB Atoll calculates the percentage of covered area ( ------------------ 100 ) and compares this value to the % minimum covered area. If SA this percentage is not exceeded, the candidate neighbour B is discarded. •
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For information on the importance calculation, see "Importance Calculation" on page 316. Importance values are used by the allocation algorithm to rank the neighbours according to the allocation reason. Atoll lists all neighbours and sorts them by importance value so as to eliminate some of them from the neighbour list if the maximum number of neighbours to be allocated to each transmitter is exceeded. If we consider the case for which there are 15 candidate neighbours and the maximum number of neighbours to be allocated to the reference cell is 8. Among these 15 candidate neighbours, only 8 (having the highest importance values) will be allocated to the reference cell. Note that specific maximum numbers of neighbours (maximum number of intra-carrier neighbours, maximum number of inter-carrier neighbours) can be defined at the cell level (property dialogue or cell table). If defined there, this value is taken into account instead of the default one available in the Neighbour Allocation dialogue. In the Results part, Atoll only displays the cells for which it finds new neighbours. For these cells, it provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason. Therefore, a neighbour may be marked as exceptional pair, co-site, adjacent, coverage or symmetric. For neighbours accepted for co-site, adjacency and coverage reasons, Atoll displays the percentage of area meeting the coverage conditions and the corresponding surface area (km2), the percentage of area meeting the adjacency conditions and the corresponding surface area (km2). Finally, if cells have previous allocations in the list, neighbours are marked as existing. •
By default, the automatic neighbour allocation compares the defined Max intersite distance with the effective inter-cell distance. As a consequence, there can be cases where the real distance between assigned neighbours is higher than the Max inter-site distance, because the effective distance is smaller. You can force Atoll to compare the Max inter-site distance with the real inter-site distance by adding the following lines in Atoll.ini: [Neighbours] RealInterSiteDistanceCondition=1
•
By default, the neighbour importance calculated with respect to distance is based on the global Max inter-site distance setting for all neighbour candidates. As a consequence, there can be cases where the calculated importance is different when the global Max inter-site distance is modified. To avoid that, you can force Atoll to prioritise the individual distances between reference cells and their respective neighbour candidates by adding the following lines in Atoll.ini: [Neighbours] CandidatesMaxDistanceInImportanceCalculation=1
4.5.2 Neighbour Allocation for a Group of Transmitters or One Transmitter Atoll allocates neighbours to: • • •
TBA cells, Neighbours of TBA cells marked as exceptional pair, adjacent and symmetric, Neighbours of TBA cells that satisfy coverage conditions.
Automatic neighbour allocation parameters are described in "Neighbour Allocation for All Transmitters" on page 312.
4.5.3 Importance Calculation Importance values are used by the allocation algorithm to rank the neighbours according to the allocation reason and the distance, and to quantify the neighbour importance.
4.5.3.1 Importance of Intra-carrier Neighbours The neighbour importance depends on the distance from the reference transmitter and on the neighbourhood cause (cf. table below); this value varies between 0 and 100%. Neighbourhood cause
When
Importance value
Existing neighbour
Only if the Delete existing neighbours option is not selected and in case of a new allocation
Existing importance
Exceptional pair
Only if the Force exceptional pairs option is selected
100 %
Co-site cell
Only if the Force co-site cells as neighbours option is selected
Importance Function (IF)
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Neighbourhood cause
When
Importance value
Adjacent layer
Only if the Force adjacent layers as neighbours option is selected
Importance Function (IF)
Adjacent cell
Only if the Force adjacent cells as neighbours option is selected
Importance Function (IF)
Neighbourhood relationship that fulfils coverage conditions
Only if the % minimum covered area is exceeded
Importance Function (IF)
Symmetric neighbourhood relationship
Only if the Force neighbour symmetry option is selected
Importance Function (IF)
Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined using the Importance Function (IF). The IF considers fourfactors for calculating the importance: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 319. d max is the maximum distance between the reference transmitter and a possible neighbour.
• • •
The co-site factor (C): a Boolean, The adjacency factor (A): the percentage of adjacency, The overlapping factor (O): the percentage of overlapping.
The minimum and maximum importance assigned to each of the above factors can be defined. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
30%
Adjacency factor (A)
Min(A)
30%
Max(A)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The Importance Function is evaluated as follows: Neighbourhood cause
Importance Function
Resulting IF using the default values from the table above
Coverage
Min(O)+Delta(O){Max(Di)(Di)+(100%Max(Di))(O)}+Min(Di)+Delta(Di)(Di)
10%+20%{10%(Di)+90%(O)}+1%+9%(Di)
Adjacent layer
(Min(A)+Max(A))/2
45%
Adjacent cells
Min(A)+Delta(A){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
30%+30%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Co-site cells
Min(C)+Delta(C){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
60%+40%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Where: Delta(X)=Max(X)-Min(X)
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• •
•
•
Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours, adjacent neighbours, and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes. The default value of Min(O) = 1% ensures that neighbours selected for symmetry will have an importance greater than 0%. With a value of Min(O) = 0%, neighbours selected for symmetry will have an importance field greater than 0% only if there is some coverage overlapping.
4.5.3.2 Importance of Inter-carrier Neighbours As indicated in the table below, the neighbour importance depends on the distance and on the neighbourhood cause; this value varies between 0 to 100%. Neighbourhood cause
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site cell
If the Force co-site cells as neighbours option is selected
Importance Function (IF)
Neighbourhood relationship that fulfils coverage conditions
If the % minimum covered area is exceeded
Importance Function (IF)
Symmetric neighbourhood relationship
If the Force neighbour symmetry option is selected
Importance Function (IF)
Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined using the Importance Function (IF). The IF considers threefactors for calculating the importance: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 319. d max is the maximum distance between the reference transmitter and a possible neighbour.
• •
The co-site factor (C): a Boolean, The overlapping factor (O): the percentage of overlapping.
The IF is user-definable using the Min importance and Max importance fields. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The IF evaluates importance as follows: Co-site Neighbourhood cause
IF
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%-Max(Di))(O)}
10%+50%{10%(Di)+90%(O)}
Yes
Min(C)+Delta(C){Max(Di)(Di)/(Max(Di)+Max(O))+ Max(O)(O)/(Max(Di)+Max(O))}
60%+40%{1/7%(Di)+6/7%(O)}
Where Delta(X)=Max(X)-Min(X)
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•
•
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Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes. The default value of Min(O) = 1% ensures that neighbours selected for symmetry will have an importance greater than 0%. With a value of Min(O) = 0%, neighbours selected for symmetry will have an importance field greater than 0% only if there is some coverage overlapping.
4.5.4 Appendices 4.5.4.1 Calculation of the Inter-Transmitter Distance Atoll takes into account the real distance ( D in m) and azimuths of antennas in order to calculate the effective intertransmitter distance ( d in m). d = D 1 + x cos – x cos where x = 0.3% so that the maximum D variation does not exceed 1%.
Figure 4.19: Inter-Transmitter Distance Computation The formula above implies that two cells facing each other will have a smaller effective distance than the real physical distance. It is this effective distance that will be taken into account rather than the real distance.
4.6 Primary Scrambling Code Allocation Downlink primary scrambling codes enable you to distinguish cells from one another (cell identification). By default, there are 512 primary scrambling codes numbered (0...511). The cells to which Atoll allocates scrambling codes are referred to as the TBA cells (cells to be allocated). TBA cells fulfil following conditions: • • • •
They are active, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone, They belong to the folder on which allocation has been executed. This folder can be either the Transmitters folder or a group of transmitters or a single transmitter. If no focus zone exists in the .atl document, Atoll takes into account the computation zone.
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4.6.1 Automatic Allocation Description 4.6.1.1 Options and Constraints The scrambling code allocation algorithm can take into account following constraints and options: •
Neighbourhood between cells,
You may consider: • • •
First order neighbours: The neighbours of TBA cells listed in the Intra-technology neighbours table, Second order neighbours: The neighbours of neighbours, Third order neighbours: The neighbour’s neighbour’s neighbours. • •
•
•
In the context of the primary scrambling code allocation, the term "neighbours" refers to intra-carrier neighbours. Atoll can take into account inter-technology neighbour relations as constraints to allocate different scrambling codes to the UMTS neighbours of a GSM transmitter. In order to consider inter-technology neighbour relations in the scrambling code allocation, you must make the Transmitters folder of the GSM .atl document accessible in the UMTS .atl document. For information on making links between GSM and UMTS .atl documents, see the User Manual. Atoll considers symmetry relationship between a cell, its first order neighbours, its second order neighbours and its third order neighbours.
Cells fulfilling a criterion on Ec/I0 (option “Additional Overlapping Conditions”),
Atoll reuses the intra-carrier neighbour allocation algorithm to determine the list of cells which cannot be allocated the same scrambling code, and to calculate their importance. For a reference cell “A”, Atoll considers all the cells “B” that can enter the active set on the area where the reference cell is the best server (area where (Ec/I0)A exceeds the minimum Ec/I0 and is the highest one and (Ec/I0)B is within a Ec/I0 margin of (Ec/I0)A).
•
•
Atoll considers either a percentage of the cell maximum powers or the total downlink power used by the cells in order to evaluate I0. In this case, I0 equals the sum of total transmitted powers. When this parameter is not specified in the cell properties, Atoll uses 50% of the maximum power.
•
Reuse distance is a constraint on the allocation of scrambling codes. A code cannot be reused at a cell that is not at least as far away as the reuse distance from the cell allocated with the particular code. Scrambling code reuse distance can be defined at cell level. If this value is not defined, then Atoll will use the default reuse distance defined in the Scrambling Code Automatic Allocation dialogue.
Reuse distance,
•
•
Exceptional pairs,
•
Domains of scrambling codes, When no domain is assigned to cells, Atoll considers the 512 primary scrambling codes available.
•
The number of primary scrambling codes per cluster. In Atoll, we call "cluster", a group of scrambling codes as defined in 3GPP specifications. 3GPP specifications define 64 clusters consisting of 8 scrambling codes (in this case, clusters are numbererd from 0 to 63). However, you can define another value (e.g. if you set the number of codes per cluster to 4, scrambling codes will be distributed in 128 clusters). When the allocation is based on a Distributed strategy (Distributed per Cell or Distributed per Site), this parameter can also be used to define the interval between the primary scrambling codes assigned to cells on a same site. The defined interval is applied by adding the following lines in the Atoll.ini file:
[PSC]
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ConstantStep = 1 For more information about setting options in the atoll.ini file, see the Administrator Manual. •
The carrier on which the allocation is run: It can be a given carrier or all of them. In this case, either Atoll independently plans scrambling codes for the different carriers, or it allocates the same primary scrambling code to each carrier of a transmitter if the option "Allocate carriers identically" is selected.
•
The possibility to use a maximum of codes from the defined domains (option "Use a Maximum of Codes"): Atoll will try to spread the scrambling code spectrum the most.
•
The "Delete All Codes" option: When selecting this option, Atoll deletes all the current scrambling codes and carries out a new scrambling code allocation. If not selected, the existing scrambling codes are kept.
In addition, it depends on the selected allocation strategy. Allocation strategies can be: •
• •
•
Clustered allocation: The purpose of this strategy is to choose for a group of mutually constrained cells, scrambling codes among a minimum number of clusters. In this case, Atoll will preferentially allocate all the codes within the same cluster. Distributed per cell allocation: This strategy consists in using as many clusters as possible. Atoll will preferentially allocate codes from different clusters. One cluster per site allocation: This strategy allocates one cluster to each site, then, one code from the cluster to each cell of each site. When all the clusters have been allocated and there are still sites remaining to be allocated, Atoll reuses the clusters as far as possible at another site. Distributed per site allocation: This strategy allocates a group of adjacent clusters to each site, then, one cluster to each transmitter on the site according to its azimuth and finally, one code from the cluster to each cell of each transmitter. The number of adjacent clusters per group depends on the number of transmitters per site you have in your network; this information is required to start allocation based on this strategy. When all the groups of adjacent clusters have been allocated and there are still sites remaining to be allocated, Atoll reuses the groups of adjacent clusters as far as possible at another site.
In the Results table, Atoll only displays scrambling codes allocated to TBA cells.
4.6.1.2 Allocation Process For each TBA cell, Atoll lists all cells which have constraints with the cell. They are referred to as near cells. The near cells of a TBA cell may be: • • • • • •
Its neighbour cells: the neighbours listed in the Intra-technology neighbours table (options “Existing neighbours” and "First Order"), The neighbours of its neighbours (options “Existing neighbours” and “Second Order”), The third order neighbours (options “Existing neighbours” and “Third Order”), The cells that fulfil Ec/I0 condition (option “Additional Overlapping Conditions”), The cells with distance from the TBA cell less than the reuse distance, The cells that make exceptional pairs with the TBA cell.
Additional constraints are considered when: • •
The cell and its near cells are neighbours of a same GSM transmitter (only if the Transmitters folder of the GSM .atl document is accessible in the UMTS .atl document), The neighbour cells cannot share the same cluster (for the "Distributed per site" allocation strategy only).
These constraints have a certain weight taken into account to determine the TBA cell priority during the allocation process and the cost of the scrambling code plan. During the allocation, Atoll tries to assign different scrambling codes to the TBA cell and its near cells. If it respects all the constraints, the cost of the scrambling code plan is 0. When a cell has too many constraints and there are not anymore scrambling codes available, Atoll breaks the constraint with the lowest cost so as to generate the scrambling code plan with the lowest cost. For information on the cost generated by each constraint, see "Cell Priority" on page 323.
4.6.1.2.1
Single Carrier Network The allocation process depends on the selected strategy. Algorithm works as follows: Strategies: Clustered and Distributed per Cell Atoll processes TBA cells according to their priority. It allocates scrambling codes starting with the highest priority cell and its near cells, and continuing with the lowest priority cells not allocated yet and their near cells. For information on calculating cell priority, see "Cell Priority" on page 323.
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Strategy: One Cluster per Site All sites which have constraints with the studied site are referred to as near sites. Atoll assigns a cluster to each site, starting with the highest priority site and its near sites, and continuing with the lowest priority sites not allocated yet and their near sites. When all the clusters have been allocated and there are still sites remaining to be allocated, Atoll reuses the clusters at another site. When the Reuse Distance option is selected, the algorithm reuses the clusters as soon as the reuse distance is exceeded. Otherwise, when the option is not selected, the algorithm tries to assign reused clusters as spaced out as possible. Then, Atoll allocates a primary scrambling code from the cluster to each cell located on the sites (codes belong to the assigned clusters). It starts with the highest priority cell and its near cells and goes on with the lowest priority cells not allocated yet and their near cells. For information on calculating site priority, see "Site Priority" on page 325. For information on calculating cell priority, see "Cell Priority" on page 323. Strategy: Distributed per Site All sites which have constraints with the studied site are referred to as near sites. Atoll assigns a group of adjacent clusters to each site, starting with the highest priority site and its near sites, and continuing with the lowest priority sites not allocated yet and their near sites. When all the groups of adjacent clusters have been allocated and there are still sites remaining to be allocated, Atoll reuses the groups of adjacent clusters at another site. When the Reuse Distance option is selected, the algorithm reuses the groups of adjacent clusters as soon as the reuse distance is exceeded. Otherwise, when the option is not selected, the algorithm tries to assign reused groups of adjacent clusters as spaced out as possible. Then, Atoll assigns each cluster of the group to each transmitter of the site according to the transmitter azimuth and selected neighbourhood constraints (options "Neighbours in Other Clusters" and "Secondary Neighbours in Other Clusters"). Then, Atoll allocates a primary scrambling code to each cell located on the transmitters (codes belong to the assigned clusters). It starts with the highest priority cell and its near cells and goes on with the lowest priority cells not allocated yet and their near cells. For information on calculating site priority, see "Site Priority" on page 325. For information on calculating cell priority, see "Cell Priority" on page 323. Determination of Groups of Adjacent Clusters In order to determine the groups of adjacent clusters to be used, Atoll proceeds as follows: It defines theoretical groups of adjacent clusters, independently of the defined domain, considering the 512 primary scrambling codes available and the specified number of codes per cluster (if this one is set to 8, 64 clusters are supposed to be available). It starts the division in group from the cluster 0 (hard coded) and takes into account the maximum number of transmitters per site user-specified in order to determine the number of clusters in each group and then, the number of possible groups. Let us assume that the number of codes per cluster is set to 8 and the maximum number of transmitters per site in the network is 3. In this case, we have the following theoretical groups: Group 1
Group 2
Group 3
Group 4
Cluster 0 Cluster 1 Cluster 2
Cluster 3 Cluster 4 Cluster 5
Cluster 6 Cluster 7 Cluster 8
Cluster 9 Cluster 10 Cluster 11
...
Group 21
...
Cluster 61 Cluster 62 Cluster 63
If no domain is assigned to cells, Atoll can use all these groups for the allocation. On the other hand, if a domain is used, the tool compares adjacent clusters really available in the assigned domain to the theoretical groups and only keeps adjacent clusters mapping the theoretical groups. Let us assume that we have a domain consisted of 12 clusters: clusters 1 to 8 and clusters 12 to 15. Therefore, Atoll will be able to use the following groups of adjacent clusters: • • • •
Group 2 with cluster 3, 4 and 5, Group 3 with cluster 6, 7 and 8, Group 6 with cluster 12, 13 and 14. The clusters 1, 2 and 15 will not be used.
If a domain does not contain any adjacent clusters, the user is warned through the 'Event Viewer'.
4.6.1.2.2
Multi-Carrier Network In case you have a multi-carrier network and you run the scrambling code allocation on all the carriers, the allocation process depends on the allocation strategy as detailed above and in addition, wether the option "Allocate Carriers Identically" is selected or not.
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When the option is not selected, algorithm works for each strategy, as explained above. On the other hand, when the option is selected, allocation order changes. It is no longer based on the cell priority but depends on the transmitter priority. All transmitters which have constraints with the studied transmitter will be referred to as near transmitters. In case of a "Per cell" strategy (Clustered and Distributed per cell), Atoll starts scrambling code allocation with the highest priority transmitter and its near transmitters and continues with the lowest priority transmitters not allocated yet and their near transmitters. The same scrambling code is assigned to each cell of the transmitter. In case of the "One cluster per site" strategy, Atoll assigns a cluster to each site and then, allocates a scrambling code to each transmitter. It starts with the highest priority transmitter and its near transmitters and continues with the lowest priority transmitters not allocated yet and their near transmitters. The same scrambling code is assigned to each cell of the transmitter. In case of the "Distributed per site" strategy, Atoll assigns a group of adjacent clusters to each site, then a cluster to each transmitter and finally, allocates a scrambling code to each transmitter. It starts with the highest priority transmitter and its near transmitters and continues with the lowest priority transmitters not allocated yet and their near transmitters. The same scrambling code is assigned to each cell of the transmitter. For information on calculating transmitter priority, see "Transmitter Priority" on page 325. When cells, transmitters or sites have the same priority, processing is based on an alphanumeric order.
4.6.1.3 Priority Determination 4.6.1.3.1
Cell Priority Scrambling code allocation algorithm in Atoll allots priorities to cells before performing the actual allocation. Priorities assigned to cells depend upon how much constrained each cell is and the cost defined for each constraint. A cell without any constraint has a default cost, C , equal to 0. The higher the cost on a cell, the higher the priority it has for the scrambling code allocation process. There are six criteria employed to determine the cell priority: •
Scrambling Code Domain Criterion
The cost due to the domain constraint, C i Dom , depends on the number of scrambling codes available for the allocation. The domain constraint is mandatory and cannot be broken. When no domain is assigned to cells, 512 scrambling codes are available and we have: C i Dom = 0 When domains of scrambling codes are assigned to cells, each unavailable scrambling code generates a cost. The higher the number of codes available in the domain, the less will be the cost due to this criterion. The cost is given as: C i Dom = 512 – Number of scrambling codes in the domain •
Distance Criterion
The constraint level of any cell i depends on the number of cells (j) present within a radius of "reuse distance" from its centre. The total cost due to the distance constraint is given as: C i Dist =
Cj Dist i j
Each cell j within the reuse distance generates a cost given as: C j Dist i = w d ij c dis tan ce Where w d ij is a weight depending on the distance between i and j. This weight is inversely proportional to the inter-cell distance. For a reuse distance of 2000m, the weight for an inter-cell distance of 1500m is 0.25, the weight for co-site cells is 1 and the weight for two cells spaced out 2100m apart is 0. c dis tan ce is the cost of the distance constraint. This value can be defined in the Constraint Cost dialogue. •
Exceptional Pair Criterion
The constraint level of any cell i depends on the number of exceptional pairs (j) for that cell. The total cost due to exceptional pair constraint is given as:
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C i EP =
cEP i – j j
Where c EP is the cost of the exceptional pair constraint. This value can be defined in the Constraint Cost dialogue. •
Neighbourhood Criterion
The constraint level of any cell i depends on the number of its neighbour cells j, the number of second order neighbours k and the number of third order neighbours l. Let’s consider the following neighbour schema:
Figure 4.20: Neighbourhood Constraints The total cost due to the neighbour constraint is given as: Ci N =
Cj N1 i + Cj – j N1 i + Ck N2 i + Ck – k N2 i + Cl N3 i + Cl – l N3 i j
j
k
k
l
l
Each first order neighbour cell j generates a cost given as: C j N1 i = I j c N1 Where I j is the importance of the neighbour cell j. c N1 is the cost of the first order neighbour constraint. This value can be defined in the Constraint Cost dialogue. Because two first order neighbours must not have the same scrambling code, Atoll considers the cost created by two first order neighbours to be each other. C j N1 i + C j N1 i C j – j N1 i = ----------------------------------------------------2 Each second order neighbour cell k generates a cost given as: C k N2 i = Max ( C j N1 i C k N1 j , C j N1 i C k N1 j ) c N2 Where c N2 is the cost of the second order neighbour constraint. This value can be defined in the Constraint Cost dialogue. Because two second order neighbours must not have the same scrambling code, Atoll considers the cost created by two second order neighbours to be each other. C k N2 i + C k N2 i C k – k N2 i = ------------------------------------------------------2 Each third order neighbour cell l generates a cost given as: C N1 i C k N1 j C l N1 k C j N1 i C k N1 j C l N1 k C l N3 i = Max j c N3 C j N1 i C k N1 j C l N1 k C j N1 i C k N1 j C l N1 k Where c N3 is the cost of the third order neighbour constraint. This value can be defined in the Constraint Cost dialogue. Because two third order neighbours must not have the same scrambling code, Atoll considers the cost created by two third order neighbours to be each other. C l N3 i + C l N3 i C l – l N3 i = ----------------------------------------------------2
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Atoll considers the highest cost of both links when a neighbour relation is symmetric and the importance value is different.
In this case, we have: C j N1 i = Max I i – j I j – i c N1 And C k N2 i = Max (C j N1 i C k N1 j ,C j N1 k C i N1 j ) c N2 •
GSM Neighbour Criterion
This criterion is considered when the co-planning mode is activated (i.e. the Transmitters folder of the GSM .atl document is made accessible in the UMTS .atl document) and inter-technology neighbours have been allocated. If the cell i is neighbour of a GSM transmitter, the cell constraint level depends on how many cells j are neighbours of the same GSM transmitter. The total cost due to GSM neighbour constraint is given as: C i N 2G =
cN2G j – Tx2G j
Where cN
2G
is the cost of the GSM neighbour constraint. This value can be defined in the Constraint Cost dialogue.
•
Cluster Criterion
When the "Distributed per Site" allocation strategy is used, you can consider additional constraints on allocated clusters (one cell, its first order neighbours and its second order neighbours must be assigned scrambling codes from different clusters). In this case, the constraint level of any cell i depends on the number of first and second order neighbours, j and k. The total cost due to the cluster constraint is given as: C i Cluster =
Cj N1 i cCluster + Ck N2 i cCluster j
k
Where c Cluster is the cost of the cluster constraint. This value can be defined in the Constraint Cost dialogue. Therefore, the total cost due to constraints on any cell i is defined as: C i = C i Dom + C i U With C i U = C i Dist + C i EP + C i N + C i N 2G + C i Cluster
4.6.1.3.2
Transmitter Priority In case you have a multi-carrier network and you run scrambling code allocation on "all" the carriers with the option "allocate carriers identically", algorithm in Atoll allots priorities to transmitters. Priorities assigned to transmitters depend on how much constrained each transmitter is and the cost defined for each constraint. The higher the cost on a transmitter, the higher the priority it has for the scrambling code allocation process. Let us consider a transmitter Tx with two cells using carriers 0 and 1. The cost due to constraints on the transmitter is given as: C Tx = C Tx Dom + C Tx U With C Tx U =
Max C U and C Dom = 512 – Number of scrambling codes in the domain Tx i Tx i
Here, the domain available for the transmitter is the intersection of domains assigned to cells of the transmitter. The domain constraint is mandatory and cannot be broken.
4.6.1.3.3
Site Priority In case of "Per Site" allocation strategies (One cluster per site and Distributed per site), algorithm in Atoll allots priorities to sites. Priorities assigned to sites depend on how much constrained each site is and the cost defined for each constraint. The higher the cost on a site, the higher the priority it has for the scrambling code allocation process.
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Let us consider a site S with three transmitters; each of them has two cells using carriers 0 and 1. The cost due to constraints on the site is given as: C S = C S U + C S Dom With C S U =
Max C U and C Dom = 512 – Number of scrambling codes in the domain S Tx S Tx
Here, the domain considered for the site is the intersection of domains available for transmitters of the site. The domain constraint is mandatory and cannot be broken.
4.6.2 Allocation Examples 4.6.2.1 Allocation Strategies and Use a Maximum of Codes In order to understand the differences between the different allocation strategies and the behaviour of algorithm when using a maximum of codes or not, let us consider the following sample scenario:
Figure 4.21: Primary Scrambling Codes Allocation Let Site0, Site1, Site2 and Site3 be four sites with 3 cells using carrier 0 whom scrambling codes have to be allocated out of three clusters consisted of 8 primary scrambling codes. This implies that the domain of scrambling codes for the four sites is from 0 to 23 (cluster 0 to cluster 2). The reuse distance is supposed to be less than the inter-site distance. Only co-site neighbours exist. The following section lists the results of each combination of options with explanation where necessary.
4.6.2.1.1
Strategy: Clustered Since the restrictions of neighbourhood only apply to co-sites with the same importance and sites distances are greater than reuse distances, every cell has the same priority. Then, scrambling code allocation to cells is performed in an alphanumeric order.
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With ‘Use a Maximum of Codes’
Atoll starts allocating the codes from the start of cluster 0 at As it is possible to use a maximum of codes, Atoll starts each site. allocation at the start of a different cluster at each site. When a cluster is reused, and there are non allocated codes left in the cluster, Atoll first allocates those codes before reusing the already used ones.
4.6.2.1.2
Strategy: Distributed Since the restrictions of neighbourhood only apply to co-sites with the same importance and sites distances are greater than reuse distances, every cell has the same priority. Then, scrambling code allocation to cells is performed in an alphanumeric order. Without ‘Use a Maximum of Codes’
With ‘Use a Maximum of Codes’
Atoll allocates codes from different clusters to each cell of Atoll allocates codes from different clusters to each site’s the same site. Under given constraints of neighbourhood and cells. As it is possible to use a maximum of codes, Atoll reuse distance, same codes can be allocated to each site’s allocates the codes so that there is least repetition of codes. cells.
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4.6.2.1.3
Strategy: ‘One Cluster per Site Since the restrictions of neighbourhood only apply to co-sites with the same importance and sites distances are greater than reuse distances, every site has the same priority. Then, cluster allocation to sites is performed in an alphanumeric order. Without ‘Use a Maximum of Codes’
With ‘Use a Maximum of Codes’
In this strategy, a cluster of codes is limited to be used at just When it is possible to use a maximum of codes, Atoll can one site at a time unless all codes and clusters have been allocate different codes from a reused cluster at another site. allocated and there are still sites remaining to be allocated. In this case Atoll reuses the clusters as far as possible at another site.
4.6.2.1.4
Strategy: ‘Distributed per Site Since the restrictions of neighbourhood only apply to co-sites with the same importance and sites distances are greater than reuse distances, every site has the same priority. Then, the group of adjacent clusters allocation to sites is performed in an alphanumeric order. Without ‘Use a Maximum of Codes’
With ‘Use a Maximum of Codes’
In this strategy, a group of adjacent clusters is limited to be When it is possible to use a maximum of codes, Atoll can used at just one site at a time unless all codes and groups of allocate different codes from a reused group of adjacent adjacent clusters have been allocated and there are still sites cluster at another site. remaining to be allocated. In this case (here only one group of adjacent clusters (clusters 0, 1 and 2) is available), Atoll reuses the group at another site.
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4.6.2.2 Allocate Carriers Identically In order to understand the behaviour of algorithm when using the option "Allocate Carriers Identically" or not, let us consider the following sample scenario: Let Site0, Site1, Site2 and Site3 be four sites with 3 cells using carrier 0 and 3 cells using carrier 1. Scrambling codes have to be allocated out of 3 clusters consisted of 8 primary scrambling codes. This implies that the domain of scrambling codes for the five sites is from 0 to 23 (cluster 0 to cluster 2). The reuse distance is supposed to be less than the inter-site distance. Only co-site neighbours exist. Allocation algorithm will be based on the "One Cluster per Site" strategy and the option "Use a Maximum of Codes" is selected. Without ‘Allocate Carriers Identically’
With ‘Allocate Carriers Identically’
Atoll allocates one cluster at each site as detailed in the In this case, Atoll allocates one cluster at each site and then, previous section. Then, it allocates a code from the cluster to one code to each transmitter so as to use a maximum of codes. Then, the same code is given to each cell of the each cell of the site so as to use a maximum of codes. transmitter. In both cases (with and without ’Allocate Carriers Identically’), every site has the same priority. Then, cluster allocation to sites is performed in an alphanumeric order.
4.7 Automatic GSM-UMTS Neighbour Allocation 4.7.1 Overview You can automatically calculate and allocate neighbours between GSM and UMTS networks. In Atoll, it is called intertechnology neighbour allocation. Inter-technology handover is used in two cases: • •
When the UMTS coverage is not continuous. In this case, the UMTS coverage is extended by UMTS-GSM handover into the GSM network, And in order to balance traffic and service distribution between both networks.
Note that the automatic inter-technology neighbour allocation algorithm takes into account both cases. In order to be able to use the inter-technology neighbour allocation algorithm, you must have: • •
An .atl document containing the GSM network, GSM.atl, and another one describing the UMTS network, UMTS.atl, An existing link on the Transmitters folder of GSM.atl into UMTS.atl.
The external neighbour allocation algorithm takes into account all the GSM TBC transmitters. It means that all the TBC transmitters of GSM.atl are potential neighbours. The cells to be allocated will be called TBA cells which, being cells of UMTS.atl, satisfy following conditions: • • • •
They are active, They satisfy the filter criteria applied to Transmitters folder, They are located inside the focus zone, They belong to the folder for which allocation has been executed. This folder can be either the Transmitters folder or a group of transmitters subfolder.
Only UMTS TBA cells may be assigned neighbours.
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4.7.2 Automatic Allocation Description The allocation algorithm takes into account criteria listed below: • • • •
The inter-transmitter distance, The maximum number of neighbours fixed, Allocation options, The selected allocation strategy,
Two allocation strategies are available: the first one is based on distance and the second one on coverage overlapping. We assume we have a UMTS reference cell, A, and a GSM candidate neighbour, transmitter B.
4.7.2.1 Algorithm Based on Distance When the automatic allocation starts, Atoll checks the following conditions: •
The distance between the UMTS reference cell and the GSM neighbour must be less than the user-definable maximum inter-site distance. If the distance between the UMTS reference cell and the GSM neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance, which corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 319.
•
The calculation options,
Carriers: This option enables you to select the carrier(s) on which you want to run the allocation. You may choose one or more carriers. Atoll will allocate neighbours to cells using the selected carriers. Force co-site cells as neighbours: It enables you to automatically include GSM transmitters located on the same site as the reference UMTS cell in the candidate neighbour list. This option is automatically selected. Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may force/forbid a GSM transmitter to be candidate neighbour of the reference UMTS cell. Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, existing neighbours are kept. •
The importance of neighbours.
Importance values are used by the allocation algorithm to rank the neighbours. Atoll lists all neighbours and sorts them by importance value so as to eliminate some of them from the neighbour list if the maximum number of neighbours to be allocated to each cell is exceeded. If we consider the case for which there are 15 candidate neighbours and the maximum number of neighbours to be allocated to the reference cell is 8. Among these 15 candidate neighbours, only 8 (having the highest importance values) will be allocated to the reference cell. Note that the maximum number of inter-technology neighbours can be defined at the cell level (property dialogue or cell table). If defined there, this value is taken into account instead of the default one available in the Neighbour Allocation dialogue. As indicated in the table below, the neighbour importance depends on the distance and on the neighbourhood cause; this value varies between 0 to 100%. Neighbourhood cause
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter
If the Force co-site cells as neighbours option is selected
100 %
Neighbourhood relationship that fulfils distance conditions
If the maximum distance is not exceeded
d1 – ---------d max
Where d is the effective distance between the UMTS reference cell and the GSM neighbour and d max is the maximum intersite distance. In the Results part, Atoll provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason. Therefore, a neighbour may be marked as exceptional pair, co-site, or distance. For neighbours accepted for distance reasons, Atoll displays the distance from the reference cell (m). Finally, if cells have previous allocations in the list, neighbours are marked as existing.
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4.7.2.2 Algorithm Based on Coverage Overlapping When automatic allocation starts, Atoll checks following conditions: •
The distance between the UMTS reference cell and the GSM neighbour must be less than the user-definable maximum inter-site distance. If the distance between the UMTS reference cell and the GSM neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance, which corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 319.
•
The calculation options,
Carriers: This option enables you to select the carrier(s) on which you want to run the allocation. You may choose one or more carriers. Atoll will allocate neighbours to cells using the selected carriers. Force co-site cells as neighbours: It enables you to automatically include GSM transmitters located on the same site as the reference UMTS cell in the candidate neighbour list. This option is automatically selected. Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may force/forbid a GSM transmitter to be candidate neighbour of the reference UMTS cell. Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, existing neighbours are kept. •
There must be an overlapping zone ( S A S B ) with a given cell edge coverage probability.
Four different cases may be considered for SA: •
1st case: SA is the area where the cell A is the best serving cell of the UMTS network. • The pilot signal received from A is greater than the minimum pilot signal level, • The pilot quality from A exceeds a user-definable minimum value (minimum Ec/I0) and is the highest one. In this case, the Ec/I0 margin must be equal to 0dB and the max Ec/I0 option disabled.
•
2nd case: SA represents the area where the pilot quality from the cell A strats decreasing but the cell A is still the best serving cell of the UMTS network. The Ec/I0 margin must be equal to 0dB, the max Ec/I0 option selected and a maximum Ec/I0 user-defined.
•
• The pilot signal received from A is greater than the minimum pilot signal level, • The pilot quality from A exceeds the minimum Ec/I0 but is lower than the maximum Ec/I0. • The pilot quality from A is the highest one. 3rd case: SA represents the area where the cell A is not the best serving cell but can enter the active set. Here, the Ec/I0 margin has to be different from 0dB and the max Ec/I0 option disabled. • •
•
The pilot signal received from A is greater than the minimum pilot signal level, The pilot quality from A is within a margin from the best Ec/I0, where the best Ec/I0 exceeds the minimum Ec/ I0. 4th case: SA represents the area where: • The pilot signal received from A is greater than the minimum pilot signal level, • The pilot quality from A is within a margin from the best Ec/I0 (where the best Ec/I0 exceeds the minimum Ec/ I0) and lower than the maximum Ec/I0. In this case, the margin must be different from 0dB, the max Ec/I0 option selected and a maximum Ec/I0 userdefined.
Two different cases may be considered for SB: •
1st case: SB is the area where the cell B is the best serving cell of the GSM network. In this case, the margin must be set to 0dB. •
•
The signal level received from B on the BCCH TRX type exceeds the user-defined minimum threshold and is the highest one. 2nd case: The margin is different from 0dB and SB is the area where: • The signal level received from B on the BCCH TRX type exceeds the user-defined minimum threshold and is within a margin from the best BCCH signal level.
SA SB - 100 ) and compares this value to the % minimum covered area. If Atoll calculates the percentage of covered area ( ----------------SA this percentage is not exceeded, the candidate neighbour B is discarded.
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Candidate neighbours fulfilling coverage conditions are sorted in descending order with respect to % of covered area. When the automatic allocation is based on coverage overlapping, we recommend you to perform two successive automatic allocations: • •
•
A first allocation in order to find handovers due to non-continuous UMTS coverage. In this case, you have to select the max Ec/I0 option and define a high enough value. A second allocation in order to complete the previous list with handovers motivated for reasons of traffic and service distribution. Here, the max Ec/I0 option must be disabled.
The importance of neighbours.
Importance values are used by the allocation algorithm to rank the neighbours according to the distance and the allocation reason. Atoll lists all neighbours and sorts them by importance value so as to eliminate some of them from the neighbour list if the maximum number of neighbours to be allocated to each cell is exceeded. If we consider the case for which there are 15 candidate neighbours and the maximum number of neighbours to be allocated to the reference cell is 8. Among these 15 candidate neighbours, only 8 (having the highest importance values) will be allocated to the reference cell. Note that the maximum number of inter-technology neighbours can be defined at the cell level (property dialogue or cell table). If defined there, this value is taken into account instead of the default one available in the Neighbour Allocation dialogue. As indicated in the table below, the neighbour importance depends on the distance and on the neighbourhood cause; this value varies between 0 to 100%. Neighbourhood reason
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter
If the Force co-site cells as neighbours option is selected
Importance Function (IF)
Neighbourhood relationship that fulfils coverage conditions
If the % minimum covered area is exceeded
Importance Function (IF)
Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined using the Importance Function (IF). The IF considers threefactors for calculating the importance: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ----------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 319. d max is the maximum distance between the reference transmitter and a possible neighbour.
• •
The co-site factor (C): a Boolean, The overlapping factor (O): the percentage of overlapping.
The IF is user-definable using the Min importance and Max importance fields. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The IF evaluates importance as follows: Co-site Neighbourhood cause
IF
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%-Max(Di))(O)}
10%+50%{10%(Di)+90%(O)}
Yes
Min(C)+Delta(C){Max(Di)(Di)/(Max(Di)+Max(O))+ Max(O)(O)/(Max(Di)+Max(O))}
60%+40%{1/7%(Di)+6/7%(O)}
Where Delta(X)=Max(X)-Min(X)
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•
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Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes.
In the Results part, Atoll provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason. Therefore, a neighbour may be marked as exceptional pair, co-site or coverage. For neighbours accepted for co-site and coverage reasons, Atoll displays the percentage of area meeting the coverage conditions and the corresponding surface area (km2). Finally, if cells have previous allocations in the list, neighbours are marked as existing. •
•
•
No prediction study is needed to perform an automatic neighbour allocation. When starting an automatic neighbour allocation, Atoll automatically calculates the path loss matrices if not found. A forbidden neighbour must not be listed as neighbour except if the neighbourhood relationship already exists and the Delete existing neighbours option is unchecked when you start the new allocation. In this case, Atoll displays a warning in the Event viewer indicating that the constraint on the forbidden neighbour will be ignored by algorithm because the neighbour already exists. In the Results, Atoll displays only the cells for which it finds new neighbours. Therefore, if a TBA cell has already reached its maximum number of neighbours before starting the new allocation, it will not appear in the Results table.
4.7.2.3 Appendices 4.7.2.3.1
Delete Existing Neighbours Option As explained above, Atoll keeps the existing inter-technology neighbours when the Delete existing neighbours option is not checked. We assume that we have an existing allocation of inter-technology neighbours. A new TBA cell i is created in UMTS.atl. Therefore, if you start a new allocation without selecting the Delete existing neighbours option, Atoll determines the neighbour list of the cell i. If you change some allocation criteria (e.g. increase the maximum number of neighbours or create a new GSM TBC transmitter) and start a new allocation without selecting the Delete existing neighbours option, it examines the neighbour list of TBA cells and checks allocation criteria if there is space in their neighbour lists. A new GSM TBC transmitter can enter the TBA cell neighbour list if allocation criteria are satisfied. It will be the first one in the neighbour list.
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Chapter 5 CDMA2000 Networks This chapter covers the following topics: •
"General Prediction Studies" on page 337
•
"Definitions and Formulas" on page 340
•
"Active Set Management" on page 358
•
"Simulations" on page 358
•
"CDMA2000 Prediction Studies" on page 392
•
"Automatic Neighbour Allocation" on page 423
•
"PN Offset Allocation" on page 430
•
"Automatic GSM-CDMA Neighbour Allocation" on page 438
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5 CDMA2000 Networks This chapter describes all the calculations performed in Atoll CDMA2000 documents. All the calculations are performed on TBC (to be calculated) transmitters. For the definition of TBC transmitters please refer to "Path Loss Matrices" on page 103.
5.1 General Prediction Studies 5.1.1 Calculation Criteria Three criteria can be studied in point analysis (Profile tab) and in common coverage studies. Study criteria are detailed in the table below: Study criteria
Formulas
Signal level ( P rec ) in dBm
Signal level received from a transmitter on a carrier (cell) P rec ic = EIRP ic – L path – M Shadowing – model – L Indoor + G term – L term L path = L model + L ant
Path loss ( L path ) in dBm Total losses ( L total ) in dBm
Tx
L total = L path + L Tx + L term + L indoor + M Shadowing – model – G Tx + G term
where, EIRP is the effective isotropic radiated power of the transmitter, ic is a carrier rank, L model is the loss on the transmitter-receiver path (path loss) calculated by the propagation model, L ant
Tx
is the transmitter antenna attenuation (from antenna patterns),
M Shadowing – model is the shadowing margin. This parameter is taken into account when the option “Shadowing taken into account” is selected, L Indoor are the indoor losses, taken into account when the option “Indoor coverage” is selected, L term are the receiver losses, G term is the receiver antenna gain, G Tx is the transmitter antenna gain, L Tx is the transmitter loss ( L Tx = L total – DL ). For information on calculating transmitter loss, "UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE Documents" on page 30. •
For CDMA2000 1xRTT systems, EIRP ic = P pilot ic + G Tx – L Tx (where, P pilot ic
•
is the cell pilot power). For CDMA2000 1xEV-DO systems, EIRP ic = P max ic + G Tx – L Tx (where P max ic
•
•
is the maximum cell power). When you make the prediction, you can consider the best carrier of all bands or the best carrier of a particular frequency band (Best (All Bands/Specific Band) option). In this case, Atoll displays the best signal level received from a transmitter. Therefore, if the network consists of 1xRTT and 1xEV-DO carriers, Atoll takes the highest power of both cells for each transmitter (i.e. the highest value between the pilot power of the 1xRTT cell and the maximum power of the 1xEV-DO cell) to calculate the received signal level. Atoll considers that G term and L term equal zero.
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5.1.2 Point Analysis 5.1.2.1 Profile Tab Atoll displays either the signal level received from the selected transmitter on a carrier ( P rec ic ), or the highest signal level received from the selected transmitter on the best carrier. •
For a selected transmitter, it is also possible to study the path loss, L path , or the total losses, L total . Path loss and total losses are the same on any carrier.
5.1.2.2 Reception Tab Analysis provided in the Reception tab is based on path loss matrices. So, you can study reception from TBC transmitters for which path loss matrices have been computed on their calculation areas. For each transmitter, Atoll displays either the signal level received on a carrier, ( P rec ic ), or the highest signal level received on the best carrier. Reception bars are displayed in a decreasing signal level order. The maximum number of reception bars depends on the signal level received from the best server. Only reception bars of transmitters whose signal level is within a 30 dB margin from the best server can be displayed. •
For a selected transmitter, it is also possible to study the path loss, L path , or the total losses, L total . Path loss and total losses are the same on any carrier.
•
You can use a value other than 30 dB for the margin from the best server signal level, for example a smaller value for improving the calculation speed. For more information on defining a different value for this margin, see the Administrator Manual.
5.1.3 Coverage Studies For each TBC transmitter, Txi, Atoll determines the selected criterion on each bin inside the Txi calculation area. In fact, each bin within the Txi calculation area is considered as a potential (fixed or mobile) receiver. Coverage study parameters to be set are: • •
The study conditions in order to determine the service area of each TBC transmitter, The display settings to select how to colour service areas.
5.1.3.1 Service Area Determination Atoll uses parameters entered in the Condition tab of the coverage study property dialogue to predetermine areas where it will display coverage. We can distinguish three cases:
5.1.3.1.1
All Servers The service area of Txi corresponds to the bins where: Txi
Txi
Txi
Minimum threshold P rec ic or L total or L path Maximum threshold
5.1.3.1.2
Best Signal Level and a Margin The service area of Txi corresponds to the bins where: Txi
Txi
Txi
Minimum threshold P rec ic or L total or L path Maximum threshold And Txi
Txj
P rec ic Best P rec ic – M ji
M is the specified margin (dB). Best function: considers the highest value.
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• • •
5.1.3.1.3
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is the highest. If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi is either the highest or 2dB lower than the highest. If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi is 2dB higher than the signal levels from transmitters, which are 2nd best servers.
Second Best Signal Level and a Margin The service area of Txi corresponds to the bins where: Txi
Txi
Txi
Minimum threshold P rec ic or L total or L path Maximum threshold And Txi
nd
Txj
P rec ic 2 Best P rec ic – M ji
M is the specified margin (dB). 2nd Best function: considers the second highest value. • • •
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is the second highest. If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi is either the second highest or 2dB lower than the second highest. If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi is 2dB higher than the signal levels from transmitters, which are 3rd best servers.
5.1.3.2 Coverage Display 5.1.3.2.1
Plot Resolution Prediction plot resolution is independent of the matrix resolutions and can be defined on a per study basis. Prediction plots are generated from multi-resolution path loss matrices using bilinear interpolation method (similar to the one used to evaluate site altitude).
5.1.3.2.2
Display Types It is possible to display the transmitter service area with colours depending on any transmitter attribute or other criteria such as: Signal Level (in dBm, dBµV, dBµV/m) Atoll calculates signal level received from the transmitter on each bin of each transmitter service area. A bin of a service area is coloured if the signal level is greater than or equal to the defined minimum thresholds (bin colour depends on signal level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as transmitter service areas. Each layer shows the different signal levels available in the transmitter service area. Best Signal Level (in dBm, dBµV, dBµV/m) Atoll calculates signal levels received from transmitters on each bin of each transmitter service area. Where other service areas overlap the studied one, Atoll chooses the highest value. A bin of a service area is coloured if the signal level is greater than or equal to the defined thresholds (the bin colour depends on the signal level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the signal level from the best server exceeds a defined minimum threshold. Path Loss (dB) Atoll calculates path loss from the transmitter on each bin of each transmitter service area. A bin of a service area is coloured if path loss is greater than or equal to the defined minimum thresholds (bin colour depends on path loss). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as service areas. Each layer shows the different path loss levels in the transmitter service area.
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Total Losses (dB) Atoll calculates total losses from the transmitter on each bin of each transmitter service area. A bin of a service area is coloured if total losses is greater than or equal to the defined minimum thresholds (bin colour depends on total losses). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as service areas. Each layer shows the different total losses levels in the transmitter service area. Best Server Path Loss (dB) Atoll calculates signal levels received from transmitters on each bin of each transmitter service area. Where other service areas overlap the studied one, Atoll determines the best transmitter and evaluates path loss from the best transmitter. A bin of a service area is coloured if the path loss is greater than or equal to the defined thresholds (bin colour depends on path loss). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the path loss from the best server exceeds a defined minimum threshold. Best Server Total Losses (dB) Atoll calculates signal levels received from transmitters on each bin of each transmitter service area. Where service areas overlap the studied one, Atoll determines the best transmitter and evaluates total losses from the best transmitter. A bin of a service area is coloured if the total losses is greater than or equal to the defined thresholds (bin colour depends on total losses). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the total losses from the best server exceed a defined minimum threshold. Number of Servers Atoll evaluates how many service areas cover a bin in order to determine the number of servers. The bin colour depends on the number of servers. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the number of servers is greater than or equal to a defined minimum threshold. Cell Edge Coverage Probability (%) On each bin of each transmitter service area, the coverage corresponds to the pixels where the signal level from this transmitter fulfils signal conditions defined in Conditions tab with different Cell edge coverage probabilities. There is one coverage area per transmitter in the explorer. Best Cell Edge Coverage Probability (%) On each bin of each transmitter service area, the coverage corresponds to the pixels where the best signal level received fulfils signal conditions defined in Conditions tab. There is one coverage area per cell edge coverage probability in the explorer.
5.2 Definitions and Formulas 5.2.1 Parameters Used for CDMA2000 1xRTT Modelling 5.2.1.1 Inputs This table lists simulation and prediction inputs (calculation options, quality targets, active set management conditions, etc.)
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Name
Value
Unit
Description
F ortho
Clutter parameter
None
Orthogonality factor
F MUD
Tx
Site equipment parameter
None
MUD factor
cn first
Frequency band parameter
None
First carrier number
cn last
Frequency band parameter
None
Last carrier number
cn
Frequency band parameter
None
Carrier number step
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Name
Value
Unit
Frequency band parameter
ic
None
Description Carrier rank of the current carrier calculated as follows: cn – cn first - – cn lower ic = ------------------------ cn Where cn lower is the number of carrier numbers lower than cn including excluded carriers and carriers of other frequency bands
Q pilot
req
Q pilot txi ic + Q pilot
min
Q pilot txi ic + Q pilot
Q pilot txi ic
req
Min. Ec/I0 - Cell parameter
min
T_Drop - Cell parameter
Q pilot
Q pilot txi ic
req
req
min
min
Active set upper threshold None (used to determine the best server in the active set) None
Active set lower threshold (used to determine other members of the active set)
Minimum Ec/I0 required from the None cell to be the best server in the active set None
Minimum Ec/I0 required from the cell not to be rejected from the active set
Variation of the minimum Ec/I0 None required from the cell to be the best server in the active set
req
Delta Min. Ec/I0 - Mobility parameter
Q pilot
min
Delta T_Drop - Mobility parameter
None
Variation of the minimum Ec/I0 required from the cell not to be rejected from the active set
RSCP min Txi ic
Cell parameter or Global parameter
W
The minimum pilot RSCP required for a user to be connected to the transmitter on a given carrier
None
Eb/Nt target for FCH channel on downlink
None
Eb/Nt target for SCH channel on downlink
None
Eb/Nt target for FCH channel on uplink
None
Eb/Nt target for SCH channel on uplink
Q pilot
DL
Q req FCH
FCH – DL
E b --- N t req
(Service, Terminal, Mobility) parameter SCH – DL
E b --- N t req
DL Q req SCH
(Service, Terminal, Mobility, SCH throughput multiple) parameter UL
Q req FCH
FCH – UL
E b --- N t req
(Service, Terminal, Mobility) parameter SCH – UL
UL Q req SCH
E b --- N t req
(Service, Terminal, Mobility, SCH throughput multiple) parameter Max
Site parameter
None
Number of channel elements available for a site on uplink
N CE –D L N I
Max
Site parameter
None
Number of channel elements available for a site on downlink
N CE –U L N I
Simulation result
None
Number of channel elements of a site consumed by users on uplink
N CE –D L N I
Simulation result
None
Number of channel elements of a site consumed by users on downlink
Overhead
Site equipment parameter
None
Number of channel elements used by the cell for common channels on uplink
Overhead
Site equipment parameter
None
Number of channel elements used by the cell for common channels on downlink
N CE –U L N I
N CE –U L
N CE –D L
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Name
Value
Unit
Description
N CE –U L
FCH
(Terminal, site equipment) parameter
None
Number of channel elements used for FCH on uplink
FCH
(Terminal, site equipment) parameter
None
Number of channel elements used for FCH on downlink
N Codes txi ic
Simulation constraint
None
Maximum number of Walsh codes available per cell (128)
N Codes txi ic
Simulation result
None
Number of Walsh codes used by the cell
NF term
Terminal parameter
None
Terminal Noise Figure
NF Tx
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
None
Transmitter Noise Figure
K
1.38 10-23
J/K
Boltzman constant
T
293
K
Ambient temperature
W
1.23 MHz
Hz
Spreading Bandwidth
N CE –D L Max
Tx DL
Cell parameter
None Inter-technology downlink noise rise
NR inter – techno log y
Cell parameter
None
Inter-technology uplink noise rise
RF ic ic adj
Network parameter If not defined, it is assumed that there is no inter-carrier interference
None
Interference reduction factor between two adjacent carriers ic
NR inter – techno log y Tx UL
Tx m
ICP ic ic i
Network parameter If not defined, it is assumed that there is no inter-technology downlink interferences due to external transmitters
and ic adj Inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the None frequency gap between ic i (external network) and ic
UL
X max DL
%Powermax
%
Maximum uplink load factor
Simulation constraint (global parameter or cell parameter)
%
Maximum percentage of used power
W
Thermal noise at transmitter
Tx UL
Tx
NF Tx K T W NR inter – techno log y
Term
NF Term K T W NR inter – techno log y
W
Thermal noise at terminal
Rc
W
bps
Chip rate
f rake efficiency
UL
Equipment parameter
DL
Terminal parameter
N0 N0
f rake efficiency SCH
TPF DL FCH
TPP – DL SCH
TPP – DL SCH
TPF UL FCH
TP P – UL SCH
TP P – UL
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Simulation constraint (global parameter or cell parameter)
Tx DL
Simulation result Terminal parameter FCH
SCH
TP P – DL TPF DL
Simulation result Terminal parameter FCH
SCH
TPP – UL TPF UL
None Uplink rake receiver efficiency factor None
Downlink rake receiver efficiency factor
SCH throughput factor (drawn None following the SCH probabilities of the service) bps
Downlink FCH peak throughput
bps
Downlink SCH bit rate
SCH throughput factor (drawn None following the SCH probabilities of the service) bps
Uplink FCH peak throughput
bps
Uplink SCH bit rate
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Name
Value
Unit
Description
W ----------------FCH TP P – DL
None
Downlink service processing gain on FCH
W ----------------SCH TP P – DL
None
Downlink service processing gain on SCH
W ----------------FCH TP P – UL
None
Uplink service processing gain on FCH
W ----------------SCH TP P – UL
None
Uplink service processing gain on SCH
DL
Service parameter
None
Downlink activity factor on FCH
AF FCH
UL
Service parameter
None
Uplink activity factor on FCH
P Sync txi ic
Cell parameter
W
Cell synchronisation channel power
P paging txi ic
Cell parameter
W
Cell other common channels (except CPICH and SCH) power
P pilot txi ic
Cell parameter
W
Cell pilot power
P max txi ic
Cell parameter
W
Maximum cell power
M pooling txi ic
Cell parameter
dB
Maximum amount of power reserved for pooling
P FCH
min
Service parameter
W
Minimum power allowed for FCH
P FCH
max
Service parameter
W
Maximum power allowed for FCH
P SCH
min
Service parameter
W
Minimum power allowed for SCH
P SCH
max
Service parameter
W
Maximum power allowed for SCH
P FCH txi ic tch
Simulation result including the term AF FCH Serv
W
Cell FCH power for a traffic channel on carrier ic
W
Total FCH power on carrier ic
Simulation result
W
Transmitter SCH power for a traffic channel on carrier ic
W
Total SCH power on carrier ic
W
Transmitter total transmitted power on carrier ic
FCH – DL
Gp
SCH – DL
Gp
FCH – UL
Gp
SCH – UL
Gp
AF FCH
P FCH txi ic
DL
P FCH txi ic tch
tch FCH ic
P SCH txi ic tch P SCH txi ic
P SCH ic tch
tch SCH ic
P tx txi ic
P pilot txi ic + P Sync txi ic + P paging txi ic + P SCH txi ic + P FCH txi ic
P term
min
Terminal parameter
W
Minimum terminal power allowed
max
Terminal parameter
W
Maximum terminal power allowed
P term FCH
Simulation result including the term AF FCH Serv
W
Terminal FCH power transmitted in carrier ic
P term ic
SCH
Simulation result
W
Terminal SCH power transmitted on carrier ic
BTS
BTS parameter
%
Percentage of BTS signal correctly transmitted
term
Terminal parameter
%
Percentage of terminal signal correctly transmitted
P term ic
UL
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Name
Value
Unit
Description
Clutter parameter
%
Percentage of pilot finger percentage of signal received by the terminal pilot finger
G Tx
Antenna parameter
None
Transmitter antenna gain
G Term
Terminal parameter
None
Terminal gain
L Tx
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
None
Transmitter lossa
L body
Service parameter
None
Body loss
L Term
Terminal parameter
None
Terminal loss
L indoor
Clutter (and, optionally, frequency band) parameter
L path
Propagation model result
None
Path loss
f
Terminal parameter
None
Number of fingers
p
Terminal parameter
%
Pilot power percentage
M Shadowing – model
Result calculated from cell edge coverage probability and model standard deviation
None
Model Shadowing margin Only used in prediction studies
M Shadowing – Ec Io
Result calculated from cell edge coverage probability and Ec/I0 standard deviation
None
Ec/I0 Shadowing margin Only used in prediction studies
None
DL gain due to availability of several pilot signals at the mobile b.
DL
M Shadowing – Eb Nt
npaths
G macro – diversity = M Shadowing – Ec Io – M Shadowing –Ec Io
DL
G macro – diversity M Shadowing – Eb Nt
Indoor loss
n=2 or 3 DL
Result calculated from cell edge coverage probability and DL Eb/Nt standard deviation
None
DL Eb/Nt Shadowing margin Only used in prediction studies
UL
Result calculated from cell edge coverage probability and UL Eb/Nt standard deviation
None
UL Eb/Nt Shadowing margin Only used in prediction studies
None
UL quality gain due to signal diversity in soft handoffc.
None
Random shadowing error drawn during Monte-Carlo simulation Only used in simulations
None
Transmitter-terminal total loss
P pilot txi ic ------------------------------LT
W
Chip power received at terminal
P FCH txi ic tch ----------------------------------------LT
W
Bit received power at terminal for FCH on carrier ic
UL
UL G macro – diversity
E Shadowing
npaths
G macro – diversity = M Shadowing – Eb Nt
UL
– M Shadowing – Eb Nt
n=2 or 3 Global parameter (default value) Simulation result
UL
In prediction studiesd For Ec/I0 calculation L path L Tx L term L body L indoor M Shadowing – Ec Io ------------------------------------------------------------------------------------------------------------------------------------G Tx G term
LT
For DL Eb/Nt calculation L path L Tx L term L body L indoor M Shadowing – Eb Nt DL ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term For UL Eb/Nt calculation L path L Tx L term L body L indoor M Shadowing – Eb Nt UL ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term In simulations L path L Tx L term L body L indoor E Shadowing -------------------------------------------------------------------------------------------------------------------G Tx G term
P c txi ic FCH – DL
Pb
344
txi ic tch
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AT330_TRR_E1
Name SCH – DL
Pb
txi ic tch FCH – DL
DL
P b txi ic tch
Pb
Value
Unit
Description
P SCH txi ic tch ----------------------------------------LT
W
Bit received power at terminal for SCH on carrier ic
W
Bit received power at terminal for FCH+SCH on carrier ic
W
Total received power at terminal from a transmitter on carrier ic
W
Total power received at terminal from traffic channels of a transmitter on carrier ic
W
Bit received power at transmitter for FCH on carrier ic
W
Bit received power at transmitter for SCH on carrier ic
W
Bit received power at transmitter for SCH+FCH on carrier ic
W
Total power transmitted by the terminal on carrier ic
W
Chip received power at transmitter
SCH – DL
txi ic tch + P b
P tx txi ic -------------------------LT
DL
P tot txi ic
DL
P traf txi ic
tch ic
P FCH txi ic + P SCH txi ic -----------------------------------------------------------------LT FCH
FCH – UL
ic
P term -----------LT
SCH – UL
ic
P term -----------LT
Pb
Pb
SCH
FCH – UL
UL
P b ic
Pb
SCH – UL
ic + P b
ic
UL
P b ic UL UL P b ic + P c ic = ---------------1 – p
UL
P tot ic UL
UL
P c ic a.
txi ic tch
p Ptot ic
L Tx = L total – UL on uplink and L Tx = L total – DL on downlink. For information on calculating transmitter losses on uplink and downlink, see "UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE Documents" on page 30.
b.
npaths
M Shadowing –Ec Io corresponds to the shadowing margin evaluated from the shadowing error probability density function (n paths) in case of downlink Ec/I0 modelling. npaths
c.
M Shadowing – Eb Nt
d.
case of uplink soft handoff modelling. In uplink prediction studies, only carrier power level is downgraded by the shadowing margin ( M Shadowing – Eb Nt
UL
corresponds to the shadowing margin evaluated from the shadowing error probability density function (n paths) in
UL
). In downlink
prediction studies, carrier power level and intra-cell interference are downgraded by the shadowing model ( M Shadowing – Eb Nt M Shadowing – Ec Io ) while extra-cell interference level is not. Therefore, M Shadowing – Eb Nt
DL
DL
or
or M Shadowing – Ec Io is set to 1 in downlink
extra-cell interference calculation.
5.2.1.2 Ec/I0 Calculation This table details the pilot quality ( Q pilot or Ec Io ) calculations. Name
Value
I intra txi ic
P tot txi ic
DL
DL
DL
I extra ic
DL
P tot txj ic
Unit
Description
W
Downlink intra-cell interference at terminal on carrier ic
W
Downlink extra-cell interference at terminal on carrier ic
W
Downlink inter-carrier interference at terminal on carrier ic
txj j i
Ptot txj icadj DL
DL I inter – carrier ic
DL I inter – techno log y ic
txj j --------------------------------------------RF ic ic adj
ni
DL
I 0 ic
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic
W
Downlink inter-technology interference at terminal on carrier ic a
i
Term
DL DL DL DL I intra txi ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0 W
Total received noise at terminal on carrier ic b
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Name
Value
Unit
Description
E Q pilot txi ic ----c I0
BTS P c txi ic -------------------------------------------------DL I 0 ic
None
Quality level at terminal on pilot for carrier ic
a.
In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the fractional load.
b.
In an active set, N 0
Term
is calculated for all its members with Inter-technology downlink noise rise of the best server.
5.2.1.3 DL Eb/Nt Calculation Eb DL This table details calculations of downlink traffic channel quality ( Q tch (tch could be FCH or SCH) or ------ ). Nt DL Name
Value
Unit
Description
I intra txi ic
1 – BTS F ortho P DL txi ic tot
W
Downlink intra-cell interference at terminal on carrier ic
W
Downlink extra-cell interference at terminal on carrier ic
W
Downlink inter-carrier interference at terminal on carrier ic
DL
DL
I extra ic
DL
P tot txj ic
txj j i
Ptot txj icadj DL
DL I inter – carrier ic
txj j ---------------------------------------------
RF ic ic adj
DL
I inter – techno log y ic
ni DL
N tot ic
DL
DL
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic
W
a
i
DL
Downlink inter-technology interference at terminal on carrier ic
Term
DL
I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0
W
Total received noise at terminal on carrier ic
None
Quality level at terminal on a traffic channel from one transmitter for a FCH channel on carrier ic b
Without useful signal: FCH – DL Pb txi
DL Q FCH txi
E DL ic ----b- N t FCH
DL Q FCH ic
BTS ic tch – DL ------------------------------------------------------------------------------------------------------ G FCH p DL DL N tot ic – 1 – F ortho BTS P b txi ic FCH – DL
BTS P b txi ic tch – DL - G FCH Total noise: -----------------------------------------------------------------p DL N tot ic DL
f rake efficiency
DL
Q FCH tx k ic
tx k ActiveSet FCH
Quality level at terminal for FCH using carrier ic due to combination of None all transmitters of the active set (Macro-diversity conditions).
Without useful signal: SCH – DL Pb txi
E DL DL Q SCH txi ic ----b- N t SCH
DL Q SCH ic
BTS ic tch – DL ------------------------------------------------------------------------------------------------------ G SCH p DL DL N tot ic – 1 – F ortho BTS P b txi ic
None
SCH – DL
BTS P b txi ic tch – DL - G SCH Total noise: -----------------------------------------------------------------p DL N tot ic DL
f rake efficiency
DL
Q SCH tx k ic
tx k ActiveSet SCH
Quality level at terminal for SCH using carrier ic due to combination of None all transmitters of the active set (Macro-diversity conditions).
DL
DL
G SHO FCH
Q FCH ic ---------------------------------------------------DL Q FCH BestServer ic
None
Downlink soft handover gain for FCH channel on carrier ic
None
Downlink soft handover gain for SCH channel on carrier ic
DL
DL
G SHO SCH
346
Q SCH ic ---------------------------------------------------DL Q SCH BestServer ic
Quality level at terminal on a traffic channel from one transmitter for a SCH channel on carrier icc
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AT330_TRR_E1
Name
Value
Unit
Description
Q req FCH ----------------------- P FCH txi ic DL Q FCH ic
W
Required transmitter FCH traffic channel power to achieve Eb/Nt target at terminal on carrier ic
W
Required transmitter SCH traffic channel power to achieve Eb/Nt target at terminal on carrier ic
W
Required transmitter traffic channel power on carrier ic
DL
req
P FCH txi ic
DL
Q req SCH ----------------------- P SCH txi ic DL Q SCH ic
req
P SCH txi ic req
req
P tch txi ic a. b.
req
P FCH txi ic + P SCH txi ic
In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the fractional load. Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt. Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt.
c.
5.2.1.4 UL Eb/Nt Calculation Eb UL This table details calculations of uplink traffic channel quality ( Q tch (tch could be FCH or SCH) or ------ ). Nt UL Name
Value
Pb
UL
UL
intra I tot txi
UL
extra
I tot
ic
UL
term txj j i UL
UL
I inter – carrier txi ic
W
Total power received at transmitter from intra-cell terminals using carrier ic
W
Total power received at transmitter from extra-cell terminals using carrier ic
W
Uplink inter-carrier interference at terminal on carrier ic
UL
P b ic + P c ic
Pb
Description
UL
ic + P c ic
term txi
txi ic
Unit
UL
ic adj + P c ic adj
term txj j ----------------------------------------------------------------------
RF ic ic adj
UL
I tot txi ic UL
N tot txi ic
UL extra
I tot
UL intra
Tx
txi ic + 1 – F MUD term I tot UL
UL W txi ic +I inter – carrier txi ic
tx
I tot txi ic + N 0
Total received interference at transmitter on carrier ic
W
Total noise at transmitter on carrier ic (Uplink interference) a
None
Quality level at transmitter on a traffic channel for the FCH channel on carrier icb
None
Quality level at transmitter on a traffic channel for the SCH channel on carrier icc
Without useful signal: FCH – UL
E UL Q FCH txi ic ----b- N t UL
term P b ic – UL -------------------------------------------------------------------------------------------------------- G FCH p UL Tx UL N tot txi ic – 1 – F MUD term P b ic FCH – UL
term P b ic FCH – UL Total noise: ----------------------------------------------- Gp UL N tot txi ic Without useful signal: SCH – UL
E UL Q SCH txi ic ----b- N t UL
term P b ic – UL -------------------------------------------------------------------------------------------------------- G SCH p UL Tx UL N tot txi ic – 1 – F MUD term P b ic SCH – UL
term P b ic SCH – UL Total noise: ----------------------------------------------- Gp UL N tot txi ic
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Name
Value
Unit
Description
UL
No HO: Q tch txi ic
UL
Softer HO: f rake efficiency
UL
Q tch txk ic
tx k ActiveSet samesite
Soft, Softer/Soft HO (No MRC): Max Q UL tch tx k tx k ActiveSet
UL
ic G macro – diversity
Softer/Soft HO (MRC):
UL
Q tch ic
UL UL UL Q tch tx k ic Q tch tx l ic tx k ,tx l ActiveSet f rake efficiency tx k samesite tx k Max
Quality level at site using carrier ic due to combination of all transmitters of the active set located at the same site and taking into account increase of the quality due None to macro-diversity (macro-diversity gain). tch could be FCH or SCH
In simulations, UL G macro – diversity
tx othersite l
= 1.
UL
G macro – diversity
UL
Q FCH ic ---------------------------------------------------UL Q FCH BestServer ic
UL G SHO FCH
None
Uplink soft handover gain for FCH channel on carrier ic
None
Uplink soft handover gain for SCH channel on carrier ic
W
Required terminal power to achieve Eb/Nt target at transmitter for FCH on carrier ic
W
Required terminal power to achieve Eb/Nt target at transmitter for SCH on carrier ic
W
Required terminal power on carrier ic
UL
Q SCH ic ---------------------------------------------------UL Q SCH BestServer ic
UL
G SHO SCH
UL
FCH – req
ic
Q req FCH ---------------------- P FCH term ic UL Q FCH ic
SCH – req
ic
Q req SCH ----------------------- P SCH term ic UL Q SCH ic
P term
UL
P term
FCH – req
req
P term ic
P term
SCH – req
ic + P term
ic
tx
a.
In an active set, N 0 is calculated for all its members with Inter-technology uplink noise rise of the best server.
b.
Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt. Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt.
c.
5.2.1.5 Simulation Results This table contains some simulation results provided in the Cells and Mobiles tabs of the simulation property dialogue. Name
DL
I intra txi ic
Value
Unit
Description
DL DL P tot txi ic – F ortho BTS P tot txi ic
None
Downlink intra-cell interference at terminal on carrier ic
W
Downlink extra-cell interference at terminal on carrier ic
DL
– 1 – F ortho BTS P b txi ic DL
I extra ic
348
txj j i
DL
P tot txj ic
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AT330_TRR_E1
Name
Value
Unit
Description
Ptot txj icadj
W
Downlink inter-carrier interference at terminal on carrier ic
DL
DL
I inter – carrier ic
txj j ---------------------------------------------
RF ic ic adj Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic
DL I inter – techno log y ic
ni DL
DL
I tot ic
DL
DL
DL
DL
DL
Term
I tot ic + N 0
Pb
UL
I tot
txi ic
UL extra
I tot
txi ic
UL
term txj j i
Pb
ic
Total effective interference at terminal on carrier ic (after unscrambling)
W
Total received noise at terminal on carrier ic
W
Total power received at transmitter from intra-cell terminals using carrier ic
W
Total power received at transmitter from extra-cell terminals using carrier ic
W
Uplink inter-carrier interference at terminal on carrier ic
UL
P b ic + P c ic
UL
UL I inter – carrier txi
W
UL
ic + P c ic
term txi
Downlink inter-technology interference at terminal on carrier ic a
i
I intra ic + I extra ic + I inter – carrier ic + I inter – techno log y ic
N tot ic UL intra
W
UL
ic adj + P c ic adj
term txj j ----------------------------------------------------------------------
RF ic ic adj
UL
I tot txi ic
UL
extra
I tot
UL
Tx
intra
txi ic + 1 – F MUD term I tot
UL
UL
N tot txi ic
UL W txi ic +I inter – carrier txi ic
tx
I tot txi ic + N 0
Total received interference at transmitter on carrier ic
W
Total noise at transmitter on carrier ic (Uplink interference)
None
Cell uplink load factor on carrier ic
UL
I tot txi ic ---------------------------UL N tot txi ic
UL
X txi ic
UL
UL
I tot txi ic --------------------------------------------------------------------------------------UL intra Tx I tot txi ic 1 – F MUD term
None
Cell uplink reuse factor on carrier ic
E txi ic
UL
1 -------------------------UL F txi ic
None
Cell uplink reuse efficiency factor on carrier ic
DL
P tx txi ic ----------------------------- 100 P max txi ic
None
Percentage of max transmitter power used.
None
Downlink load factor on carrier ic
None
Downlink reuse factor on a carrier ic
F txi ic
%Power txi ic
Simulation result available per cell DL I extra ic
DL
+ I inter – carrier ic L T --------------------------------------------------------------------------------- + 1 – F ortho BTS P tx txi ic --------------------------------------------------------------------------------------------------------------------------------1 - + 1 – F ---------tch ortho BTS DL CI req
DL
X txi ic
with
DL CI req
SCH – DL
FCH – DL
Q req Q req = -------------------+ -------------------SCH – DL FCH – DL Gp Gp
DL
I tot ic Simulation result available per mobile: -----------------DL N tot ic DL
DL
F txi ic
I tot ic ----------------------------DL I intra txi ic
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Name
Value
Description
DL
dB
Noise rise on downlink
UL
dB
Noise rise on uplink
DL
– 10 log 1 – X txi ic
UL
– 10 log 1 – X txi ic
NR txi ic NR txi ic a.
Unit
In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the fractional load.
5.2.2 Parameters Used for CDMA2000 1xEV-DO Modelling 5.2.2.1 Inputs This table lists simulation and prediction inputs (calculation options, quality targets, active set management conditions, etc.) Name
Value
Unit
Description
F ortho
Clutter parameter
None
Orthogonality factor
F MUD
Tx
Site equipment parameter
None
MUD factor
cn first
Frequency band parameter
None
First carrier number
cn last
Frequency band parameter
None
Last carrier number
cn
Frequency band parameter
None
Carrier number step
ic
Frequency band parameter
None
Carrier rank of the current carrier calculated as follows: cn – cn first - – cn lower ic = ------------------------ cn Where cn lower is the number of carrier numbers lower than cn including excluded carriers and carriers of other frequency bands
Q pilot
req
Q pilot txi ic + Q pilot
min
Q pilot txi ic + Q pilot
Q pilot txi ic
req
Min. Ec/I0 - Cell parameter
min
T_Drop - Cell parameter
Q pilot
Q pilot txi ic
req
min
min
Active set upper threshold None (used to determine the best server in the active set) None
Active set lower threshold (used to determine other members of the active set)
Minimum Ec/I0 required from the None cell to be the best server in the active set None
Minimum Ec/I0 required from the cell not to be rejected from the active set
Variation of the minimum Ec/I0 None required from the cell to be the best server in the active set
req
Delta Min. Ec/I0 - Mobility parameter
Q pilot
min
Delta T_Drop - Mobility parameter
None
Variation of the minimum Ec/I0 required from the cell not to be rejected from the active set
RSCP min Txi ic
Cell parameter or Global parameter
W
The minimum pilot RSCP required for a user to be connected to the transmitter on a given carrier
Ec --- N t min – Rev0
Mobility parameter for 1xEV-DO Rev. 0 users
None
Minimum pilot quality required in the uplink to operate EV-DO Rev. 0
Ec --- N t min – RevB
Transmitter parameter
None
Minimum pilot quality required in the uplink to operate multi-carrier EV-DO
Q pilot
UL
UL
350
req
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AT330_TRR_E1
Name Ec --- N t min UL
Value
Unit
Description
Parameter read in the 1xEV-DO Radio Bearer Selection (Uplink) table Minimum pilot quality level required None for 1xEV-DO Rev. A and Rev. B users to obtain a radio bearer in the uplink
n SF
1xEV-DO Radio Bearer Selection (Uplink) table
Number of subframes associated None with the 1xEV-DO radio bearer in the uplink
TP P – R LC
UL
1xEV-DO Radio Bearer Selection (Uplink) table
None
Uplink RLC peak throughput provided by the 1xEV-DO radio bearer
Ec --- N t min
Parameter read in the 1xEV-DO Radio Bearer Selection (Downlink) table for 1xEV-DO Rev. A and Rev. B users
None
Minimum pilot quality level required to obtain a radio bearer in the downlink
n TS
1xEV-DO Radio Bearer Selection (Downlink) table
None
Number of timeslots associated with the 1xEV-DO radio bearer in the downlink
DL
Downlink 1xEV-DO Radio Bearer Table
None
Downlink RLC peak throughput provided by the 1xEV-DO radio bearer
N EVDO – CE N I
Site parameter
None
Number of EVDO channel elements available for a site on uplink and downlink
N EVDO – CE N I
Simulation result
None
Total number of EVDO channel elements of a site consumed by users on uplink and downlink
N CE – UL
TCH
(Terminal, site equipment) parameter
None
Number of channel elements used for TCH on uplink
N MacIndexes txi ic
Simulation constraint
None
Maximum number of MAC indexes available per cell (59 for Rev0 and 114 for RevA)
N MacIndexes txi ic
Simulation result
None
Number of MAC indexes used by the cell
n EVDO txi ic
Simulation constraint (cell parameter)
None
Maximum number of EVDO users that can be connected to the cell
n EVDO txi ic
Simulation result
None
Number of EVDO users connected to the cell
NF term
Terminal parameter
None
Terminal Noise Figure
NF Tx
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
None
Transmitter Noise Figure
K
1.38 10-23
J/K
Boltzman constant
T
293
K
Ambient temperature
W
1.23 MHz
Hz
Spreading Bandwidth
NRinter – techno log y
Cell parameter
None Inter-technology downlink noise rise
NRinter – techno log y
Cell parameter
None
Inter-technology uplink noise rise
RF ic ic adj
Network parameter If not defined, it is assumed that there is no inter-carrier interference
None
Interference reduction factor between two adjacent carriers ic
DL
TP P – R LC
Max
Max
Max
Tx DL
Tx UL
Tx m
ICP ic ic i
Network parameter If not defined, it is assumed that there is no inter-technology downlink interferences due to external transmitters
and ic adj Inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the None frequency gap between ic i (external network) and ic
UL
X max
Simulation constraint (global parameter or cell parameter)
%
Maximum uplink load factor
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Name
Value Tx UL
Unit
Description
W
Thermal noise at transmitter
Tx
NF Tx K T W NR inter – techno log y
Term
NF Term K T W NR inter – techno log y
W
Thermal noise at terminal
Rc
W
bps
Chip rate
f rake efficiency
Equipment parameter
N0 N0
UL
UL
Tx DL
None Uplink rake receiver efficiency factor
Simulation result
bps
Uplink throughput
TP TCP – ACK
Simulation result
bps
Uplink throughput due to TCP aknowledgements
TPBCMCS
Cell parameter
bps
Downlink throughput for Broadcast/ Multicast services
TP max – DL
Simulation result
bps
Downlink peak throughput supplied to the terminal
TP avg
Simulation result
bps
Downlink average cell throughput
TPD min – UL
Service parameter
kbps
Minimum required bit rate that the service should have in order to be available in the uplink
TPD min – DL
Service parameter
kbps
Minimum required bit rate that the service should have in order to be available in the downlink
TPA
f TP – Scaling TP max – DL – TP Offset
bps
Downlink user application throughput
f TP – Scaling
Service parameter
%
Scaling factor
TPOffset
Service parameter
kbps
Offset
C DL – Bearer
TPD min – DL -----------------------------------------------------------DL TP P – R LC Index DL – Bearer
%
Downlink radio bearer consumption for a (1xEV-DO Rev. A - Guaranteed Bit Rate) service user
C UL – Bearer
TPD min – UL -----------------------------------------------------------UL TP P – R LC Index UL – Bearer
%
Uplink radio bearer consumption for a (1xEV-DO Rev. A - Guaranteed Bit Rate) service user
Gp
W---------UL TP
None
Uplink service processing gain on FCH
G idle – power
Cell parameter
None
Idle power gain
G MU
Cell parameter
None
Multi user gain
P max txi ic
Cell parameter
W
Max cell power
P tx txi ic b pilot
P max txi ic
W
Pilot burst transmitted by the transmitter on carrier ic.
W
Traffic burst transmitted by the transmitter on carrier ic.
TP UL
DL
DL
UL
P tx txi ic b traffic
352
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P max txi ic if users to support P max txi ic G idle – power if no user to support
ER DRC
Cell parameter
%
Error rate on the DRC channel
TS BCMCS
Cell parameter
%
Pourcentage of EVDO timeslots dedicated to Broadcast/Multicast services
TS EVDO – CCH
Cell parameter
%
Pourcentage of EVDO timeslots dedicated to control channels
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AT330_TRR_E1
Name
Value
Unit
Description
P term ic
Simulation result
W
Terminal power transmitted on carrier ic
P term
min
Terminal parameter
W
Minimum terminal power allowed
P term
max
Terminal parameter
W
Maximum terminal power allowed
BTS
BTS parameter
%
Percentage of BTS signal correctly transmitted
term
Terminal parameter
%
Percentage of terminal signal correctly transmitted
Clutter parameter
%
Percentage of pilot finger percentage of signal received by the terminal pilot finger
G Tx
Antenna parameter
None
Transmitter antenna gain
G Term
Terminal parameter
None
Terminal gain
L Tx
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
None
Transmitter lossa
L body
Service parameter
None
Body loss
L Term
Terminal parameter
None
Terminal loss
L indoor
Clutter (and, optionally, frequency band) parameter
L path
Propagation model result
None
Path loss
G ACK
Terminal parameter
None
Acknowledgement Channel gain
G RRI
Terminal parameter (for 1xEV-DO Rev A terminals only)
None
Reverse Rate Indicator Channel gain
G DRC
Terminal parameter
None
Data Rate Control Channel gain
G Auxiliary – pilot
Terminal parameter (for 1xEV-DO Rev A terminals only)
None
Auxiliary Pilot Channel gain
G TCH
Terminal parameter
None
Traffic data Channel gain
carriers
Terminal parameter
None
Maximum number of carriers in multi-carrier mode
M Shadowing – model
Result calculated from cell edge coverage probability and model standard deviation
None
Model Shadowing margin Only used in prediction studies
M Shadowing – Ec Io
Result calculated from cell edge coverage probability and Ec/I0 standard deviation
None
Ec/I0 Shadowing margin Only used in prediction studies
None
DL gain due to availability of several pilot signals at the mobile b.
None
UL Eb/Nt Shadowing margin Only used in prediction studies
None
UL quality gain due to signal diversity in soft handoffc.
None
Random shadowing error drawn during Monte-Carlo simulation Only used in simulations
n max
DL
n=2 or 3 UL
Result calculated from cell edge coverage probability and UL Eb/Nt standard deviation UL
UL G macro – diversity
E Shadowing
npaths
G macro – diversity = M Shadowing – Ec Io – M Shadowing –Ec Io
DL
G macro – diversity M Shadowing – Eb Nt
Indoor loss
npaths
G macro – diversity = M Shadowing – Eb Nt
UL
– M Shadowing – Eb Nt
n=2 or 3 Global parameter (default value) Simulation result
UL
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Name
Value
Unit
Description
None
Transmitter-terminal total loss
P tx txi ic b pilot ----------------------------------------LT
W
Pilot burst received at terminal from a transmitter on carrier ic
P tx txi ic b traffic --------------------------------------------LT
W
Traffic burst received at terminal from a transmitter on carrier ic
P b ic
P term -----------LT
W
Bit received power at transmitter on carrier ic
NRthreshold txi ic
Cell parameter
dB
Cell uplink noise rise threshold
Cell parameter
dB
Cell uplink noise rise upgrading/ downgrading delta
In prediction studiesd For Ec/I0 and Ec/Nt calculations L path L Tx L term L body L indoor M Shadowing – Ec Io ------------------------------------------------------------------------------------------------------------------------------------G Tx G term For UL Eb/Nt calculation L path L Tx L term L body L indoor M Shadowing – Eb Nt UL ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term
LT
In simulations L path L Tx L term L body L indoor E Shadowing -------------------------------------------------------------------------------------------------------------------G Tx G term DL
P tot txi ic b pilot DL
P tot txi ic b traffic UL
UL
UL
NR threshold txi ic a.
L Tx = L total – UL on uplink and L Tx = L total – DL on downlink.
b.
M Shadowing –Ec Io corresponds to the shadowing margin evaluated from the shadowing error probability density function (n paths) in case
npaths
of downlink Ec/I0 modelling. npaths
c.
M Shadowing – Eb Nt
d.
case of uplink soft handoff modelling. In uplink prediction studies, only carrier power level is downgraded by the shadowing margin ( M Shadowing – Eb Nt
UL
corresponds to the shadowing margin evaluated from the shadowing error probability density function (n paths) in
UL
). In downlink
prediction studies, carrier power level and intra-cell interference are downgraded by the shadowing model ( M Shadowing – Ec Io ) while extra-cell interference level is not. Therefore, M Shadowing – Ec Io is set to 1 in downlink extra-cell interference calculation.
5.2.2.2 Ec/I0 and Ec/Nt Calculations E E E This table details ----c txi ic b pilot , ----c- txi ic b pilot and ----c- txi ic b traffic calculations. I0 Nt Nt Name
Value
Unit
Description
txi ic DL I intra b pilot or b traffic
0
W
Downlink intra-cell interference at terminal on carrier ic (only one mobile is served at a time)
W
Downlink extra-cell interference based on pilot at terminal on carrier ic
DL
I extra ic b pilot
DL
I extra ic b traffic
P tot txj ic b pilot
P tot txj ic b traffic
W
Downlink extra-cell interference based on traffic at terminal on carrier ic
Ptot txj icadj bpilot
W
Downlink inter-carrier interference based on pilot at terminal on carrier ic
DL
txj j i DL
txj j i DL
DL I inter – carrier ic
354
b pilot
txj j ------------------------------------------------------------RF ic ic adj
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AT330_TRR_E1
Name
Value
Unit
Description
Ptot txj icadj btraffic
W
Downlink inter-carrier interference based on traffic at terminal on carrier ic
DL
DL
I inter – carrier ic b traffic
txj j ---------------------------------------------------------------RF ic ic adj
DL I inter – techno log y ic
ni DL
W
DL
+
DL
W
Total noise based on pilot received at terminal on carrier ic
W
Total noise based on traffic received at terminal on carrier ic
I extra ic b pilot + N 0
W
Total noise based on pilot received at terminal on carrier ic
DL
W
Total noise based on traffic received at terminal on carrier ic
None
Pilot quality level at terminal on carrier ic
None
Pilot quality level at terminal on carrier ic
None
Traffic quality level at terminal on carrier ic
DL I inter – techno log y ic
DL
+
DL
term N0
DL
P tot txi ic b traffic + I extra ic b traffic + I inter – carrier ic b traffic
DL
I 0 ic b traffic
+
DL
DL I inter – techno log y ic DL
N tot ic b pilot DL
N tot ic b traffic
+
term N0
term
term
I extra ic b traffic + N 0
Q pilot txi ic
DL
BTS P tot txi ic b pilot ---------------------------------------------------------------------DL I 0 ic b pilot
Ec ---- txi ic b pilot I0
Downlink inter-technology interference at terminal on carrier ic a
i
P tot txi ic b pilot + I extra ic b pilot + I inter – carrier ic b pilot
DL
I 0 ic b pilot
a.
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic
DL
E ----c- txi ic b pilot Nt
BTS P tot txi ic b pilot ---------------------------------------------------------------------------------------------------------------DL DL N tot ic b pilot + 1 – BTS P tot txi ic b pilot
E ----c- txi ic b traffic Nt
BTS P tot txi ic b traffic ----------------------------------------------------------------------------------------------------------------------DL DL N tot ic b traffic + 1 – BTS P tot txi ic b traffic
DL
In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the fractional load.
5.2.2.3 UL Eb/Nt Calculation This table details calculations of uplink quality ( Q Name
intra I tot txi
UL
extra I tot txi
Eb or ------ ). Nt UL
Value
Pb
UL
UL
UL
ic
term txi
ic
term txj j i
Pb
ic
Description
W
Total power received at transmitter from intra-cell terminals using carrier ic
W
Total power received at transmitter from extra-cell terminals using carrier ic
W
Uplink inter-carrier interference at terminal on carrier ic
UL
P b ic
UL
UL I inter – carrier txi
ic
Unit
ic adj
term txj j -----------------------------------
RF ic ic adj
UL
I tot txi ic UL
N tot txi ic
UL extra
I tot
UL intra
Tx
txi ic + 1 – F MUD term I tot UL
tx
I tot ic + N 0
UL W txi ic +I inter – carrier txi ic
W
Total received interference at transmitter on carrier ic Total noise at transmitter on carrier ic (Uplink interference)
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Name
Value
Unit
Description
None
Quality level at transmitter on carrier ica
Without useful signal: UL
term P b ic -------------------------------------------------------------------------------------------------------- G UL p UL Tx UL N tot txi ic – 1 – F MUD term P b ic
E UL Q txi ic ----b- N t UL
UL
term P b ic UL Total noise: ----------------------------------- Gp UL N tot txi ic UL
No HO: Q txi ic
UL
Softer HO: f rake efficiency
UL
Q tch txk ic
tx k ActiveSet samesite
Soft, Softer/Soft HO (No MRC): Max Q UL tch tx k tx k ActiveSet
ic
UL G macro – diversity
Softer/Soft HO (MRC):
UL
Q total ic
UL UL UL Q tch tx k ic Q tch tx l ic tx ,tx ActiveSet f rake efficiency k l tx k samesite tx k Max
Quality level at site using carrier ic due to combination of all transmitters of the active set located at the same site and taking into account increase of the quality due None to macro-diversity (macro-diversity gain).
In simulations, UL G macro – diversity
= 1.
tx l othersite
UL
G macro – diversity
UL
Q total ic ------------------------------------------------UL Q BestServer ic
UL
G SHO
None
Uplink soft handover gain on carrier ic
None
Eb/Nt target on uplink
W
Required terminal power to achieve Eb/Nt target at transmitter on carrier ic
For 1xEV-DO Rev 0 terminal UL E UL ----c- G p 1 + G ACK + G DRC + G TCH N t min For 1xEV-DO Rev A terminalb When the acknoledgement signal is considered
UL
Q req
UL
Ec UL --- G p 1 + G ACK + G RRI + G DRC + G TCH + G Auxiliary – Pilot N t min When the acknoledgement signal is not considered UL E UL ----c- G p 1 + G RRI + G DRC + G TCH + G Auxiliary – Pilot N t min UL
Q req ---------------------- P term UL Q total ic
req
P term ic
a.
Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt. In simulations, the uplink Eb/Nt target is calculated without considering the acknowledgement signal.
b.
5.2.2.4 Simulation Results This table contains some simulation results provided in the Cells and Mobiles tabs of the simulation property dialogue.
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AT330_TRR_E1
Name
Value
Unit
Description
I intra txi ic b traffic
1 – F ortho BTS P tot txi ic b traffic = 0
DL
W
Downlink intra-cell interference at terminal on carrier ic (only one mobile is served at a time)
W
Downlink extra-cell interference based on traffic at terminal on carrier ic
W
Downlink inter-carrier interference based on traffic at terminal on carrier ic
DL
DL
I extra ic b traffic
DL
P tot txj ic b traffic
txj j i
Ptot txj icadj btraffic DL
DL I inter – carrier ic
b traffic
txj j ---------------------------------------------------------------RF ic ic adj Tx
P Transmitted ic i
------------------------------------Tx Tx m L ICP
DL
I inter – techno log y ic
DL
DL
I tot ic b traffic
n i ic
total
ni
DL
DL
DL
term
I tot ic b traffic + N 0
Pb
UL
intra I tot txi
UL extra
I tot
ic
ic
term txi
txi ic
Total effective interference based on traffic at terminal on carrier ic (after unscrambling)
W
Total noise based on traffic received at terminal on carrier ic
W
Total power received at transmitter from intra-cell terminals using carrier ic
W
Total power received at transmitter from extra-cell terminals using carrier ic
W
Uplink inter-carrier interference at terminal on carrier ic
UL
P b ic
term txj j i
Pb
UL
UL I inter – carrier txi
W
DL
+ I inter – techno log y ic
DL
ic
Downlink inter-technology interference at terminal on carrier ic a
I intra ic b traffic + I extra ic b traffic + I inter – carrier ic b traffic
N tot ic b traffic UL
W
ic adj
term txj j -----------------------------------
RF ic ic adj
UL
I tot txi ic
UL extra
I tot
UL intra
Tx
txi ic + 1 – F MUD term I tot
UL W txi ic +I inter – carrier txi ic
Total received interference at transmitter on carrier ic
N tot txi ic
I tot txi ic + N 0
W
Total noise at transmitter on carrier ic (Uplink interference)
N mobiles txi ic
Simulation result
None
Number of mobiles connected to transmitter txi on carrier ic
UL
UL
tx
N GBR –m obiles txi ic
Simulation result
None
Number of (1xEV-DO Rev. A Guaranteed bit rate) service users connected to transmitter txi on carrier ic
N VBR –m obiles txi ic
Simulation result
None
Number of (1xEV-DO - Variable bit rate) service users connected to transmitter txi on carrier ic
DL
X txi ic
DL
I tot ic b traffic ------------------------------------DL N tot ic b traffic
None Cell downlink load factor on carrier ic
UL
UL
I tot txi ic ---------------------------UL N tot txi ic
UL
I tot txi ic --------------------------------------------------------------------------------------UL intra Tx I tot txi ic 1 – F MUD term
X txi ic
None
Cell uplink load factor on carrier ic
None
Cell uplink reuse factor on carrier ic
UL
F txi ic
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Name UL
E txi ic
Value
Unit
Description
1 --------------------------UL F txi ic
None
Cell uplink reuse efficiency factor on carrier ic
DL
dB
Noise rise on downlink
UL
dB
Noise rise on uplink
DL
– 10 log 1 – X txi ic
UL
– 10 log 1 – X txi ic
NR txi ic NR txi ic a.
©Forsk 2015
In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the fractional load.
5.3 Active Set Management The mobile active set is the list of the transmitters to which the mobile is connected. The active set may consist of one or more transmitters; depending on whether the service supports soft handoff and on the terminal active set size. Transmitters in the mobile active set must use a frequency band with which the terminal is compatible and the pilot signal level received from these transmitters must exceed the defined minimum RSCP threshold. It is, however, the quality of the pilot (Ec⁄I0) that finally determines whether or not a transmitter can belong to the active set. Cells entering the mobile’s active set must fulfill the following conditions: •
The best server (first cell entering active set) In order for a given transmitter to enter the mobile active set as best server, the quality of this transmitter’s pilot must be the highest one and it must exceed an upper threshold equal to the sum of the minimum Ec/I0 defined in the properties of the best serving cell and the Delta minimum Ec/I0 defined in the properties of the mobility type. The upper threshold is set for the carrier as defined in the cell properties and can also take into account the user mobility type if the Delta minimum Ec/I0 defined in the mobility type is different from 0. The carrier used by the transmitters in the active set corresponds to the best carrier of the best server. For information on the best carrier selection, see the Technical Reference Guide.
•
In order for a transmitter to enter the active set (other cells of active set): • They must use the same carrier as the best server cell, • The pilot quality from other candidate cells must exceed a lower threshold. The lower threshold depends both on the type of carrier and the mobility type. It is equal to the sum of T_Drop defined in the properties of the best server and the Delta T_Drop defined in the properties of the mobility type. • If you have selected to restrict the active set to neighbours, the cell must be a neighbour of the best server (the "restricted to neighbours” option is selected in the equipment properties).
For multi-carrier EVDO Rev.B users, the active set may consist of several sub-active sets, each one being associated with one carrier. The number of sub-active sets depends on the maximum number of carriers supported by the terminal. As detailed above, the quality of the pilot (Ec⁄I0) determines whether or not a transmitter can belong to a sub-active set. The sub-active set associated with the best carrier is the same as the active set of a single-carrier user. For the other carriers, the uplink Ec⁄Nt received by the best server on the best carrier and on the studied carrier determines whether or not a carrier can have a subactive set, and the transmitters in the sub-active sets depend on the mode supported by the terminal (locked mode or unlocked mode): • • •
The Ec/Nt received by the best serving transmitter on the best carrier must exceed the minimum uplink Ec/Nt defined in the properties of the transmitter. The Ec/Nt received by the best serving transmitter on the studied carrier must exceed the minimum uplink Ec/Nt defined in the properties of the transmitter. When the locked mode is used, the serving transmitters must be the same in all sub-active sets. With the unlocked mode, the serving transmitters may be different from one sub-active set to another.
5.4 Simulations The simulation process is divided into two steps: 1. Obtaining a realistic user distribution Atoll generates a user distribution using a Monte-Carlo algorithm, which requires traffic maps and data as input. The resulting user distribution complies with the traffic database and maps provided to the algorithm. Each user is assigned a service, a mobility type, and an activity status by random trial, according to a probability law that uses the traffic database.
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The user activity status is an important output of the random trial and has direct consequences on the next step of the simulation and on the network interferences. A user may be either active or inactive. Both active and inactive users consume radio resources and create interference. Additionally, each 1xEV-DO Rev. 0 user is assigned a transition flag ("True" or "False") for each possible throughput transition (from 9.6 to 19.2 kbps, 19.2 to 38.4 kbps, 38.4 to 76.8 kbps, and 76.8 to 153.6 kbps for throughput upgrading and from 153.6 to 76.8 kbps, 76.8 to 38.4 kbps, 38.4 to 19.2 kbps, and 19.2 to 9.6 kbps for throughput downgrading). These transition flags are based on the throughput downgrading and upgrading probabilities. If a transition flag is "True," the user throughput can be downgraded or upgraded if necessary. Then, Atoll randomly assigns a shadowing error to each user using the probability distribution that describes the shadowing effect. Finally, another random trial determines user positions in their respective traffic zone and whether they are indoors or outdoors (according to the clutter weighting and the indoor ratio per clutter class defined for the traffic maps). 2. Modelling the network regulation mechanism This algorithm depends on the network. Atoll uses a power control algorithm in case of CDMA2000 1xRTT networks and a different algorithm, which mixes throughput control on downlink and power control on uplink, for CDMA2000 1xEV-DO networks.
5.4.1 Generating a Realistic User Distribution 5.4.1.1 Number of Users, User Activity Status and User Throughput During the simulation, a first random trial is performed to determine the number of users and their activity status. The determination of the number of users and the activity status allocation depend on the type of traffic cartography used. Atoll determines the total number of users attempting connection in each simulation based on the Poisson distribution. This may lead to slight variations in the total numbers of users in different simulations. To have the same total number of users in each simulation of a group, add the following lines in the Atoll.ini file: [Simulation] RandomTotalUsers=0
5.4.1.1.1
Simulations Based on User Profile Traffic Maps User profile environment based traffic maps: Each pixel of the map is assigned an environment class which contains a list of user profiles with an associated mobility type and a given density (number of subscribers with the same profile per km²). User profile traffic maps: Each polygon and line of the map is assigned a density of subscribers with given user profile and mobility type. If the map is composed of points, each point is assigned a number of subscribers with given user profile and mobility type. The user profile models the behaviour of the different subscriber categories. Each user profile contains a list of services and their associated parameters describing how these services are accessed by the subscriber. From environment (or polygon) surface (S) and user profile density (D), a number of subscribers (X) per user profile is inferred. X = SD •
•
In case of user profile traffic maps composed of lines, the number of subscribers (X) per user profile is calculated from the line length (L) and the user profile density (D) (nb of subscribers per km) as follows: X = L D The number of subscribers (X) is an input when a user profile traffic map is composed of points.
For each behaviour described in a user profile, according to the service, frequency use and exchange volume, Atoll calculates the probability for the user being connected in uplink and in downlink at an instant t. •
Calculation of the service usage duration per hour ( p 0 : probability of a connection):
N call d p 0 = ------------------3600 where N call is the number of calls per hour and d is the average call duration (in second).
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Then, Atoll calculates the total number of users trying to access a certain service. •
Calculation of the number of users trying to access the service j ( n j ):
nj = X p0 The next step determines the activity status of each user. •
Calculation of number of users per activity status:
This steps depends on the type of service (Voice, 1xRTT data, 1xEV-DO data…). •
CDMA2000 1xRTT Services
Activity status of voice and data service users is determined as follows. Users are always active on FCH in both directions, uplink and downlink. Therefore, we have: Probability of being active on UL: p UL = 0 Probability of being active on DL: p DL = 0 Probability of being active both on UL and DL: p UL + DL = 1 Probability of being inactive: p inactive = 0 Thus, for voice and data services, we have: Number of inactive users: n j inactive = n j p inactive = 0 Number of users active on UL: n j UL = n j p UL = 0 Number of users active on DL: n j DL = n j p DL = 0 Number of users active on UL and DL both: n j UL + DL = n j p UL + DL = n j n j = n j UL + n j DL + n j UL + DL + n j inactive = n j UL + DL •
Voice Users
Voice users are active on uplink and downlink. However, the FCH can have inactivity periods on both links. This is modelled by UL
DL
the FCH activity factor, AF FCH and AF FCH . Therefore, all voice service users try to access the service with the following FCH FCH
UL
FCH
DL
throughputs, TP P – UL AF FCH on uplink and TP P – DL AF FCH on downlink. FCH
FCH
TP P – UL and TP P – DL are respectively the uplink and downlink FCH peak throughputs. •
Data Users
Data service users are active on uplink and downlink. FCH is always allocated but can have inactivity periods on both links; this UL
DL
is modelled by the FCH activity factor, AF FCH and AF FCH . SCH may be allocated with four possible throughputs (2x, 4x, 8x and 16xFCH peak throughput). Therefore, data service users can access the service with different throughputs. Possible throughputs are detailed in the table below:
Only FCH is used
SCH throughput factor rk
On UL
-
TP P – UL AF FCH
2x
TP P – UL AF FCH + 2
4x
TP P – UL AF FCH + 4
8x
TP P – UL AF FCH + 8
16x
TP P – UL AF FCH + 16
Both FCH and SCH are used
FCH
Allocated throughputs
FCH
On DL UL
DL
FCH
UL
TPP – DL AF FCH + 2
FCH
UL
TPP – DL AF FCH + 4
FCH
UL
TPP – DL AF FCH + 8
FCH
UL
FCH
TP P – UL and TP P – DL are respectively the uplink and downlink FCH peak throughputs. Then, Atoll determines the distribution of users between the different possible throughputs.
360
FCH
TP P – DL AF FCH FCH
DL
FCH
DL
FCH
DL
FCH
DL
TP P – DL AF FCH + 16
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AT330_TRR_E1 UL
DL
In case of a data service, j, several data throughput probabilities, P k
and P k , can be assigned to different throughput
factors, r k , for SCH channel. For non-data services, these probabilities are 0.
For data service users, a random trial compliant with throughput probabilities is performed for each link in order to determine the throughput for each user. On uplink, we have: rk
FCH
UL
FCH
DL
For each SCH throughput factor, r k , the number of users n j with the throughput TP P – UL AF FCH + r k is calculated as follows, rk
UL
nj = Pr nj k
FCH
Therefore, the number of users n j FCH
nj
= nj –
FCH
UL
with the throughput, TP P – UL AF FCH , is:
rk
nj r
k
On downlink, we have: rk
For each SCH throughput factor, r k , the number of users, n j with the throughput, TP P – DL AF FCH + r k , is calculated as follows, rk
DL
nj = Pr nj k
FCH
Therefore, the number of users n j FCH
nj
= nj –
r
nj
FCH
DL
with the throughput, TP P – DL AF FCH , is:
k
rk
•
CDMA2000 1xEV-DO Services
As power control is performed in the uplink only, 1xEV-DO data service users will be considered either active in the uplink or inactive. 1xEV-DO data Rev. 0 service users can access the service with uplink throughputs of 9.6, 19.2, 38.4, 76.8 and 153.6 kbps. 1xEV-DO data Rev. A and Rev. B service users can access the service with uplink throughputs of 4.8, 9.6, 19.2, 38.4, 76.8, 115.2, 153.6, 230.4, 307.2, 460.8, 614.4, 921.6, 1,228.8 and 1,848.2 kbps. UL
UL
For each service, j, several throughput probabilities, P k , can be assigned to different throughputs TP k . The number of users active on uplink ( n j UL ) and the number of inactive users ( n j inactive ) are calculated as follows: Probability of being active on UL: p UL =
Pk
UL
UL
TP k
UL Rk
Probability of being inactive: p inactive = 1 –
Pk
UL
UL
TP k
UL Rk
Probability of being active on DL: p DL = 0 Probability of being active on UL and DL both: p UL + DL = 0 Therefore, we have: Number of users active on UL: n j UL = n j p UL Number of inactive users: n j inactive = n j p inactive Number of users active on DL: n j DL = n j p DL = 0
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Number of users active on UL and DL both: n j UL + DL = n j p UL + DL = 0 n j = n j UL + n j DL + n j UL + DL + n j inactive = n j UL + n j inactive UL
Then, Atoll determines the distribution of users between the different possible throughputs, TP k . The number of users with UL
UL
the throughput TP k , n j TP k , is calculated as follows: UL
UL
n j TP k = P k n j Inactive users have a requested throughput equal to 0. •
• •
The user distribution per service is an average distribution and the service of each user is randomly drawn in each simulation. Therefore, if you compute several simulations at once, the average number of users per service will correspond to the calculated distribution. But if you check each simulation, the user distribution between services is different in each of them. It is the same for the SCH throughput distribution between 1xRTT data service users and the traffic throughput distribution between 1xEV-DO data service users. In calculations detailed above, we assume that the sum of throughput probabilities is less than or equal to 1. If the sum of throughput probabilities exceeds 1, Atoll considers normalised throughput probabilities values, P r k
rk
P r , instead of k
specified throughput probabilities P r . k
5.4.1.1.2
Simulations Based on Sector Traffic Maps Sector traffic maps can be based on live traffic data from OMC (Operation and Maintenance Centre). Traffic is spread over the best server coverage area of each transmitter and each coverage area is assigned either the throughputs in the uplink and in the downlink, or the number of users per activity status or the total number of users (including all activity statuses). CDMA2000 1xRTT Services •
Voice Service (j)
For each transmitter, Txi, Atoll proceeds as follows: •
When selecting Throughputs in Uplink and Downlink, you can input the throughput demands in UL ( TPD DL ( TPD
DL
UL
) and
) for each sector.
Atoll calculates the number of users active in UL and DL using the voice service in the Txi cell as follows: UL
DL
N UL = TPD --------------- and N DL = TPD --------------UL DL TP j TP j Where, UL
TPD is the number of kbits per second transmitted in UL in the Txi cell to provide the service j to the users (userdefined value in the traffic map properties) DL
TPD is the number of kbits per second transmitted in DL in the Txi cell to provide the service j to the users (userdefined value in the traffic map properties). UL
TP j
DL
and TP j
correspond to the UL and DL throughputs of a user. FCH is always allocated to active users but UL
can have inactivity periods on both links. Therefore, we have TP j
FCH
UL
FCH
= TP P – UL AF FCH (where TP P – UL is the
UL
service FCH peak throughput on UL and AF FCH corresponds to the FCH activity factor on UL) and DL
TP j
FCH
DL
FCH
DL
= TPP – DL AF FCH (where TP P – DL is the service FCH peak throughput on DL and AF FCH corresponds to the
FCH activity factor on DL). Users are always active on FCH for both links. Therefore, we have following activity probabilities. Probability of being active in UL: p UL = 0
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Probability of being active in DL: p DL = 0 Probability of being active in UL and DL both: p UL + DL = 1 Probability of being inactive: p inactive = 0 Then, Atoll calculates the number of users per activity status: Number of users active in UL and DL both: n j UL + DL = max (N UL,N DL) Number of users active in UL and inactive in DL: n j UL = 0 Number of users active in DL and inactive in UL: n j DL = 0 inactive
Number of inactive users in UL and DL: n j
= 0
Therefore, all connected voice users ( n j ) are active in both links. •
When selecting Total Number of Users (All Activity Statuses), you can input the number of connected users for each sector ( n j ). Users are always active on FCH for both links. Therefore, we have following activity probabilities. Probability of being active in UL: p UL = 0 Probability of being active in DL: p DL = 0 Probability of being active in UL and DL both: p UL + DL = 1 Probability of being inactive: p inactive = 0 Then, Atoll calculates the number of users per activity status: inactive
Number of inactive users in UL and DL: n j
= n j p inactive = 0
Number of users active in UL and inactive in DL: n j UL = n j p UL = 0 Number of users active in DL and inactive in UL: n j DL = n j p DL = 0 Number of users active in UL and DL both: n j UL + DL = n j p UL + DL = n j Therefore, all connected users ( n j ) are active in both links. •
When selecting Number of Users per Activity Status, you can directly input the number of users active in the uplink and downlink ( n j UL + DL ), for each sector. FCH
UL
FCH
DL
Voice service users try to access the service with the FCH throughputs, TPP – UL AF FCH on uplink and TP P – DL AF FCH on downlink. All user characteristics determined, a second random trial is performed to obtain their geographical positions. •
Data Service Users (j)
FCH is always allocated to active users but can have inactivity periods on both links. This is modelled by the FCH activity factors, UL
DL
AF FCH and AF FCH . SCH may be allocated with four possible throughputs (2x, 4x, 8x, 16xFCH peak throughput). Several UL
DL
throughput probabilities, P k and P k , can be assigned to different throughputs factor, r k , for SCH channel. For non-data services, these probabilities are 0.
For each transmitter, Txi, Atoll proceeds as follows: •
When selecting Throughputs in Uplink and Downlink, you can input the throughput demands in UL ( TPD DL ( TPD
DL
UL
) and
) for each sector.
Atoll calculates the number of users active in UL and DL using the service in the Txi cell as follows:
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UL
DL
N UL = TPD --------------- and N DL = TPD --------------UL DL TP j TP j Where, UL
TPD is the number of kbits per second transmitted in UL in the Txi cell to provide the service j to the users (userdefined value in the traffic map properties) DL
TPD is the number of kbits per second transmitted in DL in the Txi cell to provide the service j to the users (userdefined value in the traffic map properties). UL
TP j UL
Pj
=
DL
and TP j
rk
DL
Pj
=
correspond to uplink and downlink throughputs of a user.
UL UL UL r k + AF FCH R FCH P r + 1 – k
rk
UL FCH UL P r TP P – UL AF FC k
rk + AFFCH RFCH Prk + 1 – Prk TPP – DL AFFC DL
DL
DL
rk FCH
FCH
DL
rk
DL
FCH
TP P – UL and TP P – DL are the uplink and downlink FCH peak throughputs respectively. •
In calculations detailed above, we assume that the sum of throughput probabilities is less than or equal to 1. If the sum of throughput probabilities exceeds 1, Atoll considers normalised throughput probabilities values, P r k
rk
P r , instead of k
specified throughput probabilities P r . k
Users are always active on FCH for both links. Therefore, we have following activity probabilities. Probability of being active in UL: p UL = 0 Probability of being active in DL: p DL = 0 Probability of being active in UL and DL both: p UL + DL = 1 Probability of being inactive: p inactive = 0 Then, Atoll calculates the number of users per activity status and the total number of users: Number of users active in UL and DL both: n j UL + DL = max (N UL,N DL) Number of users active in UL and inactive in DL: n j UL = 0 Number of users active in DL and inactive in UL: n j DL = 0 inactive
Number of inactive users in UL and DL: n j
= 0
Therefore, all connected users ( n j ) are active in both links. •
When selecting Total Number of Users (All Activity Statuses), you can input the number of connected users for each sector ( n j ). Users are always active on FCH for both links. Therefore, we have following activity probabilities. Probability of being active in UL: p UL = 0 Probability of being active in DL: p DL = 0 Probability of being active in UL and DL both: p UL + DL = 1 Probability of being inactive: p inactive = 0
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Then, Atoll calculates the number of users per activity status: inactive
Number of inactive users in UL and DL: n j
= n j p inactive = 0
Number of users active in UL and inactive in DL: n j UL = n j p UL = 0 Number of users active in DL and inactive in UL: n j DL = n j p DL = 0 Number of users active in UL and DL both: n j UL + DL = n j p UL + DL = n j Therefore, all connected users ( n j ) are active in both links. •
When selecting Number of Users per Activity Status, you can directly input the number of users active in the uplink and downlink ( n i UL + DL ), for each sector.
As explained above, data service users can access the service with different throughputs. Possible throughputs are detailed in the table below: SCH throughput factor rk Only FCH is used
Allocated throughputs On UL FCH TP P – UL
-
On DL
UL AF FCH
FCH TP P – DL
FCH
UL
TP P – DL AF FCH + 2
FCH
UL
TP P – DL AF FCH + 4
FCH
UL
TP P – DL AF FCH + 8
2x
TPP – UL AF FCH + 2
4x
TPP – UL AF FCH + 4
8x
TPP – UL AF FCH + 8
16x
TPP – UL AF FCH + 16
Both FCH and SCH are used
DL
AF FCH
FCH
UL
FCH
DL
FCH
DL
FCH
DL
FCH
DL
TP P – DL AF FCH + 16
Atoll determines the distribution of users with the different possible throughputs. A random trial compliant with throughput probabilities is performed for each link in order to determine the throughput of each user. On uplink, we have, rk
FCH
UL
FCH
DL
For each SCH throughput factor, r k , the number of users n j with the throughput TP P – UL AF FCH + r k is calculated as follows, rk
UL
nj = Pr nj k
FCH
Therefore, the number of users n j FCH
nj
= nj –
FCH
UL
with the throughput, TP P – UL AF FCH , is,
rk
nj rk
On downlink, we have, r
k
For each SCH throughput factor, r k , the number of users, n j with the throughput, TP P – DL AF FCH + r k , is calculated as follows, k
DL
nj = Pk nj FCH
Therefore, the number of users n j FCH
nj
= nj –
FCH
DL
with the throughput, TP P – DL AF FCH , is,
rk
nj rk
CDMA2000 1xEV-DO Services As power control is performed in the uplink only, 1xEV-DO data service users will be considered either active in the uplink or inactive. 1xEV-DO data Rev. 0 service users can access the service with uplink throughputs of 9.6, 19.2, 38.4, 76.8 and 153.6 kbps. 1xEV-DO data Rev. A and Rev. B service users can access the service with uplink throughputs of 4.8, 9.6, 19.2, 38.4, 76.8, 115.2, 153.6, 230.4, 307.2, 460.8, 614.4, 921.6, 1,228.8 and 1,848.2 kbps.
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UL
For each service, j, several throughput probabilities, P k , can be assigned to different uplink throughputs TP k . The number of users active in uplink ( n j UL ) and the number of inactive users ( n j inactive ) are calculated into several steps. First of all, Atoll determines the number of users active in UL using the service j in the Txi cell. For each transmitter, Txi, and each service j: •
When selecting Throughputs in Uplink and Downlink, you can input the throughput demands in UL ( TPD each sector.
UL
) for
Atoll calculates the number of users active in UL using the service j in the Txi cell as follows: UL
N UL = TPD --------------UL TP j UL
Where TPD is the number of kbits per second transmitted on UL in the Txi cell to provide the service j (userdefined value in the traffic map properties). UL
TP j
UL
TP j
corresponds to the uplink throughput for a user. =
Pk
UL
UL
TP k
k
In the above calculations, we assume that the sum of throughput probabilities is less than or equal to 1. If the sum of throughput probabilities exceeds 1, Atoll considers normalised throughput probabilities values, P r k
rk
P r , instead of specified k
throughput probabilities P r . k
We have the following activity probabilities: Probability of being active in UL: p UL =
Pk
UL
UL
TP k
UL Rk
Probability of being inactive: p inactive = 1 –
Pk
UL
R
UL
TP k
UL k
Probability of being active in DL: p DL = 0 Probability of being active in UL and DL both: p UL + DL = 0 Therefore, we have: Number of users active in UL: n j UL = N UL p UL Number of inactive users: n j inactive = N UL p inactive Number of users active in DL: n j DL = 0 Number of users active in UL and DL both: n j UL + DL = 0 Total number of connected users: n j = n j UL + n j inactive •
When selecting Total Number of Users (All Activity Statuses), you can input the number of connected users for each sector ( n j ). We have the following activity probabilities: Probability of being active in UL: p UL =
Pk
UL
UL Rk
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Probability of being inactive: p inactive = 1 –
Pk
UL
R
UL
TP k
UL k
Probability of being active in DL: p DL = 0 Probability of being active in UL and DL both: p UL + DL = 0 Therefore, we have: Number of users active in UL: n j UL = n j p UL Number of inactive users: n j inactive = n j p inactive Number of users active in DL: n j DL = 0 Number of users active in UL and DL both: n j UL + DL = 0 •
When selecting Number of Users per Activity Status, you can directly input the number of inactive users ( n j inactive ) and the number of users active in the uplink ( n j UL ), for each sector. The total number of connected users ( n j ) is calculated as follows n j = n j UL + n j inactive
Then, Atoll determines the distribution of users with the different possible throughputs. The number of users with the UL
UL
throughput TP k , n j TP k , is calculated as follows: UL
UL
n j TPk = P k n j Inactive users have a requested throughput equal to 0. The user distribution per service is an average distribution and the service of each user is randomly drawn In each simulation. Therefore, if you compute several simulations at once, the average number of users per service will correspond to the calculated distribution. But if you check each simulation, the user distribution between services is different in each of them. It is the same for the SCH throughput distribution between 1xRTT data service users and the traffic throughput distribution between 1xEV-DO data service users.
5.4.1.2 Transition Flags for 1xEV-DO Rev.0 User Throughputs For 1xEV-DO Rev. 0 services supporting throughput downgrading, you can define the probability of the service being upgraded UL
UL
UL
UL
UL
( P Upg – k TP k ) or downgraded ( P Downg – k TP k ) on the uplink (reverse link) for each throughput ( TP k ). The probabilities are taken into account in order to determine if a user with a certain throughput can be upgraded or downgraded. User throughput downgrading and upgrading occur during congestion control when the cell is over- or underloaded. The following table shows the throughput changes that are possible when a throughput is upgraded or downgraded. The probabilities are defined with a number from 1 to 255 for each throughput. Possible Throughput Changes During Upgrading
Possible Throughput Changes During Downgrading
From
To
From
To
9.6 kbps
19.2 kbps
153.6 kbps
76.8 kbps
19.2 kbps
38.4 kbps
76.8 kbps
38.4 kbps
38.4 kbps
76.8 kbps
38.4 kbps
19.2 kbps
76.8 kbps
153.6 kbps
19.2 kbps
9.6 kbps
During the generation of the user distribution, each 1xEV-DO Rev. 0 user is assigned a random number between 1 and 255 for each possible throughput transition. When this number is lower or equal to the value of the probability, the transition flag for this throughput transition is set to "True" meaning that this throughput transition can be performed if necessary.
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The number of 1xEV-DO Rev. 0 users with a certain throughput that can be downgraded ( n j TP k Downg ) and upgraded UL
( n j TP k Upg ) are calculated as follows: UL
UL
UL
P Upg – k TP k n j TP k UL n j TP k Upg = -----------------------------------------------------------255 And UL
UL
UL
P Downg – k TP k n j TP k UL n j TP k Downg = -----------------------------------------------------------------255 The number of users with a certain throughput that can be downgraded or upgraded is an average. Therefore, if you compute several simulations at once, the average number of users with a certain throughput that can be downgraded or upgraded will correspond to the calculated value. But if you check each simulation, this number is different in each of them.
5.4.1.3 User Geographical Position Once all the user characteristics determined, another random trial is performed to obtain their geographical positions and whether they are indoors or outdoors according to the percentage of indoor users per clutter class defined for the traffic maps.
5.4.2 Network Regulation Mechanism 5.4.2.1 CDMA2000 1xRTT Power Control Simulation Algorithm CDMA2000 1xRTT network automatically regulates itself using traffic driven uplink and downlink power control on the fundamental and supplemental channels (FCH and SCH respectively) in order to minimize interference and maximize capacity. Atoll simulates this network regulation mechanism with an iterative algorithm and calculates, for each user distribution, network parameters such as base station power, mobile terminal power, active set and handoff status for each terminal. The power control simulation is based on an iterative algorithm, where in each iteration, all the mobiles selected during the user distribution generation (1st step) try to connect to network active transmitters with a calculation area. The process is repeated from iteration to iteration until convergence is achieved. The algorithm steps are detailed below.
Figure 5.1: CDMA2000 1xRTT Power Control Algorithm
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5.4.2.1.1
Algorithm Initialization Total power on carrier ic, P Tx ic , of base station Sj is initialised to P pilot ic + P sync ic + P paging ic . UL
intra
Uplink received powers on carrier ic, I tot
UL
extra
ic , I tot
UL
ic and I inter – carrier ic , at base station Sj are initialised to 0 W
(no connected mobile). UL
I tot S j ic UL - = 0 X k S j ic = ------------------------UL N tot S j ic
5.4.2.1.2
Presentation of the Algorithm UL
The algorithm is detailed for any iteration k. Xk is the value of the variable X at the iteration k. In the algorithm, all Q req and DL
Q req thresholds depend on user mobility type and are defined in Service and Mobility parameters tables. All variables are described in Definitions and formulas part. The algorithm applies to single frequency band networks and to multi-band networks (dual-band and tri-band networks). Multi-band terminals can have the following configurations: • •
Configuration 1: The terminal can work on f1, f2 and f3 without any priority (select "All" as main frequency band in the terminal property dialogue). Configuration 2: The terminal can work on f1, f2 and f3 but f1 has a higher priority (select "f1" as main frequency band, "f2" as secondary frequency band and "f3" as third frequency band in the terminal property dialogue).
For each mobile (Mi), Atoll only considers the cells (Sj,ic) for which the pilot RSCP exceeds the minimum pilot RSCP: P c Sj M i ic RSCP min Sj ic . For each mobile Mi, we have the following steps: Determination of Mi’s Best Serving Cell For each transmitter Sj containing Mi in its calculation area and working on the main frequency band supported by the Mi’s terminal (i.e. either f1 for a single frequency band network, or f1, f2 or f3 for a multi-band terminal with the configuration 1, or f1 for a multi-band terminal with the configuration 2). BTS P c Sj M i ic Calculation of Q pilot Sj ic M i = ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------Term k DL DL DL DL P tot Sj ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0 Determination of the candidate cells, (SBS,ic). For each carrier ic, selection of the transmitter with the highest Q pilot Sj M i ic , S BS ic M i . k
Analysis of candidate cells, (SBS,ic). For each pair (SBS,ic), calculation of the uplink load factor: UL
I tot S BS ic UL UL X k S BS ic = ----------------------------+ X UL N tot S BS ic Rejection of bad candidate cells if the pilot is not received or if the uplink load factor is exceeded during the admission load control (if simulation respects a loading factor constraint and Mb was not connected in previous iteration) pilot
If Q pilot S BS M i ic Q req then (SBS,ic) is rejected by Mi k UL
UL
If X k S BS ic X max , then (SBS,ic) is rejected by Mi Else Keep (SBS,ic) as good candidate cell For multi-band terminals with the configuration 1 or terminals working on one frequency band only, if no good candidate cell has been selected, Mi has failed to be connected to the network and is rejected. For multi-band terminals with the configuration 2, if no good candidate cell has been selected, try to connect Mi to transmitters txi containing Mi in their calculation area and working on the secondary frequency band supported by the Mi’s terminal (i.e. f2). If no good candidate cell has been selected, try to connect Mi to transmitters txi containing Mi in their
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calculation area and working on the third frequency band supported by the Mi’s terminal (i.e. f3). If no good candidate cell has been selected, Mi has failed to be connected to the network and is rejected. Determination of the best carrier, icBS. If a given carrier is specified for the service requested by Mi ic BS M i is the carrier specified for the service Else the carrier selection mode defined for the site equipment is considered. If carrier selection mode is “Min. UL Load Factor” UL
ic BS M i is the cell with the lowest X k S BS ic Else if carrier selection mode is “Min. DL Total Power” ic BS M i is the cell with the lowest P tx S BS ic k Else if carrier selection mode is “Random” ic BS M i is randomly selected Else if carrier selection mode is "Sequential" UL
UL
ic BS M i is the first carrier where X k S BS ic X max Endif Determination of the best serving cell, (SBS,icBS). max
(S BS,ic BS) k M i is the best serving cell ( BestCell k M i ) and its pilot quality is Q pilot M i . k
In the following lines, we will consider ic as the carrier used by the best serving cell. Determination of the Active Set For each station Sj containing Mi in its calculation area, using ic, and if neighbours are used, neighbour of BestCell k M i BTS P c M i S j Calculation of Q pilot M i S j ic = ------------------------------------------------DL k I 0 ic Rejection of station Sj if the pilot is not received pilot
If Q pilot M i S j ic Q min then Sj is rejected by Mi k Else Sj is included in the Mi active set Rejection of Sj if the Mi active set is full Station with the lowest Q pilot in the active set is rejected k
EndFor Uplink Power Control req
Calculation of the required power for Mi, P term M i ic k For each cell (Sj,ic) present in the Mi active set Calculation of quality level on Mi traffic channel at (Sj,ic), with the minimum power allowed on traffic channel for the Mi service FCH – U L
Pb
FCH – r eq
SCH – r eq
P term M i ic k – 1 P term M i ic k – 1 SCH – U L - and P b M i S j ic = --------------------------------------------- M i S j ic = ---------------------------------------------L T M i S j L T M i S j FCH – U L
term P b M i S j ic UL – UL - G FCH Q FCH M i S j ic k = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Service p UL FCH – U L SCH – U L N tot ic – 1 – F MUD term P b M i S j ic + P b M i S j ic
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term P b M i S j ic UL – UL - G SCH Q SCH M i S j ic k = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Service p UL FCH – U L SCH – U L N tot ic – 1 – F MUD term P b M i S j ic + P b M i S j ic If the user selects the option “Total noise” FCH – U L
term P b M i S j ic UL – UL - G FCH Q FCH M i S j ic k = ------------------------------------------------------------- Service p UL N tot ic SCH –U L
term P b M i S j ic UL – UL - G SCH Q SCH M i S j ic k = ------------------------------------------------------------- Service p UL N tot ic End For If (Mi is not in handoff) UL
UL
UL
UL
Q FCH M i = Q FCH M i S j ic k and Q SCH M i = Q SCH M i S j ic k k
k
Else if (Mi is in softer handoff) UL
UL
Q FCH M i = f rake efficiency k
UL
UL
Q FCH M i S j ic k
S j ActiveSet UL
Q SCH M i = f rake efficiency k
UL
Q SCH M i S j ic k
S ActiveSet j
Else if (Mi is in soft or softer/soft without MRC) UL
UL
UL
Q FCH M i = G macro – diversity 2 links Max Q FCH M i S j ic k k
UL
S j ActiveSet
UL
UL
Q SCH M i = G macro – diversity 2 links Max Q SCH M i S j ic k k
S j ActiveSet
Else if (Mi is in soft/soft) UL
UL
UL
Q FCH M i = G macro – diversity 3 links Max Q FCH M i S j ic k k
UL
S j ActiveSet
UL
UL
Q SCH M i = G macro – diversity 3 links Max Q SCH M i S j ic k k
S j ActiveSet
Else if (Mi is in softer/soft with MRC) UL UL UL UL Q FCH M i = Max f rake efficiency Q FCH ic Q FCH k other site i AS ActiveSet
UL ic G macro – diversity 2 links
UL UL UL UL Q SCH M i = Max f rake efficiency Q SCH ic Q SCH k other site i ActiveSet AS
UL ic G macro – diversity 2 links
(same site)
(same site)
EndIf FCH – r eq
P term
UL
Q req Service M i Term M i Mobility M i FCH – r eq - P FCH M i ic k = -------------------------------------------------------------------------------------------------------------------------- M i ic k – 1 term UL Q FCH M i k
SCH – r eq
P term
UL
Q req Service Mi Term M i Mobility M i SCH_rate_multiple SCH – r eq - P SCH M i ic k = --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- M i ic k – 1 term UL Q SCH M i k
req
FCH – r eq
P term M i ic k = P term
SCH – r eq
M i ic k + P term
M i ic k
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min
If P term M i ic k P term M i then FCH – r eq
P term
SCH – r eq
P term
min
P term M i S j – r eq - P FCH M i ic k = ----------------------------- M i ic k term req P term M i k min
P term M i S j – r eq - P SCH M i ic k = ----------------------------- M i ic k term req P term M i k
EndIf FCH – r eq
If P term
max
M i ic k P term M i then Mi cannot select any station and its active set is cleared
req
max
If P term M i ic k P term M i and Mi uses SCH then: Downgrading the service SCH throughput: req
max
SCH
FCH
While P term M i ic k P term M i and TP P – UL Service M i TPP – UL Service M i 2 SCH
TP P – UL Service M i SCH TP P – UL Service M i ----------------------------------------------------2 SCH – r eq
SCH – r eq
P term
UL SCH P term M i ic Q req Service M i Term M i Mobility M i TP P – UL Service Mi SCH M i ic k = -----------------------------------------k ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------UL SCH 2 Q Service M Term M Mobility M TP Service M 2 req
req
FCH – r eq
P term M i ic k = P term
SCH – r eq
M i ic k + P term
i
i
P – UL
i
i
SCH
M i ic k
EndWhile req
max
If P term M i ic k P term M i then Mi will not use SCH Endif Endif If the required number of channel elements exceeds the available quantity in the site of Sj (Best server of Mi) and Mi uses SCH then: Downgrading the service SCH throughput: Max
SCH
FCH
While N CE –U L M i N CE –U L S j and TP P – UL Service M i TP P – UL Service M i 2 SCH
TP P – UL Service M i SCH TP P – UL Service M i ----------------------------------------------------2 SCH
N CE –U L M i k SCH N CE –U L M i k = ----------------------------2 SCH – r eq
SCH – r eq P term M i
SCH – UL SCH P term M i ic Service M i Term M i Mobility M i TP P – UL Service Mi Q req ic k = -----------------------------------------k -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------SCH – UL SCH 2 Q Service M Term M Mobility M TP Service M 2 req
req
FCH – r eq
P term M i ic k = P term SCH
SCH – r eq
M i ic k + P term
i
i
i
P – UL
M i ic k
FCH
N CE –U L M i k = N CE –U L M i k + N CE –U L M i k EndWhile Endif Downlink Power Control If Mi uses an SCH on the downlink For each cell (Sj,ic) in Mi FCH active set Calculation of quality level on (Sj,ic) FCH at Mi, with the minimum power allowed on FCH for the Mi service
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FCH – D L
Pb
min
P FCH Service M i M i S j ic = ---------------------------------------------L T M i S j FCH – D L
DL Q FCH M i
BTS P b M i S j – DL - G FCH S j ic k = ------------------------------------------------------------------------------------------------------------ Service M i p DL DL N tot ic – 1 – F ortho BTS P b M i S j ic
If the user selects the option “Total noise” FCH – D L
BTS P b M i S j DL Q FCH M i S j ic k = ----------------------------------------------------DL N tot ic If cell (Sj,ic) in Mi SCH active set Calculation of quality level on (Sj,ic) SCH at Mi, with the minimum power allowed on SCH for the Mi service SCH – D L
Pb
min
P SCH Service M i M i S j ic = ---------------------------------------------L T M i S j SCH – D L
BTS P b M i S j DL – DL - G SCH Q SCH M i S j ic k = ------------------------------------------------------------------------------------------------------------ Service Mi p DL DL N tot ic – 1 – F ortho BTS P b M i S j ic If the user selects the option “Total noise” SCH – D L
BTS P b M i S j DL Q SCH M i S j ic k = ----------------------------------------------------DL N tot ic EndIf End For Recombination of the first f active set links (f is the number of fingers of the Mi terminal): only quality levels from the first f cells (Sf,ic) of active set are recombined. DL
DL
Q FCH M i = f rake efficiency k
Q FCH M i S j ic k
Q SCH M i S j ic k
DL
S f ActiveSet FCH
DL
DL
Q SCH M i = f rake efficiency k
DL
S f ActiveSet SCH
Do For each cell (Sj,ic) in Mi FCH active set Calculation of the required power for DL traffic channel between (Sj,ic) and Mi: DL
FCH
Q req Service M i Term M i Mobility M i TP P – DL Service M i FCH req - P min P FCH M i S j ic k = -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------FCH Service M i DL Q FCH M i k
req
max
If P FCH M i S j ic k P FCH Service M i then S j ic is excluded from Mi active set DL
Recalculation of a decreased Q req If cell (Sj,ic) in Mi SCH active set Calculation of the required power for DL traffic channel between (Sj,ic) and Mi: DL
SCH
Q req Service M i Term M i Mobility M i TP P – DL Service M i SCH req - P min P SCH M i S j ic k = -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------SCH Service M i DL Q SCH M i k
Downgrading the service SCH throughput (only for (Sj,ic) best server cell of Mi): req
max
SCH
While P SCH M i S j ic k P SCH Service M i TP P – DL Service M i req
SCH
FCH
Or P tx S j ic k + P tch M i S j ic k P max S j ic and TPP – DL Service M i TP P – DL Service M i 2
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SCH
TP P – DL Service M i SCH TP P – DL Service M i = ----------------------------------------------------2 req
DL
SCH
P SCH M i S j ic k Q req Service M i Term M i Mobility M i TPP – DL Service M i SCH req ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------P SCH M i S j ic k = -------------------------------------DL SCH 2 Q Service M Term M Mobility M TP Service M 2 req
req
req
i
i
i
P – DL
i
SCH
req
P tch M i S j ic k = P SCH M i S j ic k + P FCH M i S j ic k EndWhile req
max
req
If P SCH M i S j ic k P SCH Service M i or P tx S j ic k + P tch M i S j ic k P max S j ic then Mi will not use SCH Endif Max
SCH
FCH
While N CE –D L M i N CE –D L S j and TP P – DL Service M i TP P – DL Service Mi 2 SCH
TP P – DL Service M i SCH TP P – DL Service M i = ----------------------------------------------------2 SCH
N CE –D L M i k SCH N CE –D L M i k = ----------------------------2 req
DL
SCH
P SCH M i S j ic k Q req Service M i Term M i Mobility M i TPP – DL Service M i SCH req P SCH M i S j ic k = ------------------------------------- ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------DL SCH 2 Q Service M Term M Mobility M TP Service M 2 req
req
req
i
i
i
P – DL
i
SCH
req
P tch M i S j ic k = P SCH M i S j ic k + P FCH M i S j ic k FCH
SCH
N CE –D L M i k = N CE –D L M i k + N CE –D L M i k EndWhile Max
If N CE –D L M i N CE –D L S j then Mi will not use SCH Endif Max
SCH
FCH
While N Codes M i N Codes S j ic and TP P – DL Service M i TP P – DL Service Mi 2 SCH
TP P – DL Service M i SCH TP P – DL Service M i = ----------------------------------------------------2 SCH
N Codes M i k SCH N Codes M i k = ---------------------------2 req
DL
SCH
P SCH M i S j ic k Q req Service M i Term M i Mobility M i TPP – DL Service M i SCH req P SCH M i S j ic k = ------------------------------------- ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------DL SCH 2 Q Service M Term M Mobility M TP Service M 2 req
req
req
i
i
i
P – DL
i
SCH
req
P tch M i S j ic k = P SCH M i S j ic k + P FCH M i S j ic k FCH
SCH
N Codes M i k = N Codes M i k + N Codes M i k EndWhile Max
If N Codes M i N Codes S j ic then Mi will not use SCH Endif Endif EndFor Recombination of the first f active set links (f is the number of fingers of the Mi terminal): only quality levels from the first f cells (Sf,ic) of active set are recombined. DL
DL
Q FCH M i = f rake efficiency k
374
DL
Q FCH M i S f ic k
S f ActiveSet FCH
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DL
DL
Q SCH M i = f rake efficiency k
DL
Q SCH M i S f ic k
S ActiveSet SCH f DL
DL
While Q k M i Q req Service M i Mobility M i and Mi FCH active set is not empty DL
DL
And Q k M i Q req Service M i Mobility M i (if SCH active set is not empty) Endif Uplink and Downlink Interference Updates Update of interference on active mobiles only (old contributions of mobiles and stations are replaced by the new ones) For each cell (Sj,ic) UL
Update of N tot S j ic EndFor For each mobile Mi DL
Update of N tot ic EndFor Control of Radio Resource Limits (Walsh Codes, Cell Power and Site Channel Elements) For each cell (Sj,ic) on a site Nl P tx S j ic DL While -------------------------k %Power max P max req
Rejection of mobile with highest P tch S j M b ic k for the lowest service priority EndWhile EndFor For each site Nl The list of rejected mobiles for the site Nl is L rejected N l If the equipment installed on Nl supports power pooling between transmitters Activation of power pooling between transmitters for each cell (Sj,ic) containing rejected users Control of the available power for the other cells (Si,ic) of the site where power pooling between transmitters is not activated If
DL
%Power max P max – P tx S i ic k 0
S i ic Si Nl
Then, the power unused by the cells (Si,ic) of the site can be allocated to cells (Sj,ic) Sort of all the rejected mobiles by priority in a descending order and by simulation rank in a descending order For the first mobile Mb of the list ( M b L rejected N l ) req
DL
If P tx S j ic k + P tch S j M b ic k %Power max P max + M Pooling S j ic Mb is reconnected EndIf EndFor EndIf EndFor For each cell (Sj,ic) Max
While N Codes S j ic k N Codes S j ic
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Rejection of last admitted mobile EndFor For each site (Node B) Nl Max
While N CE – DL N I k N CE – DL N I req
Rejection of mobile with highest P tch M i S j k for the lowest service priority Max
While N CE – UL N I k N CE – UL N I req
Rejection of mobile with highest P term M i ic k for the lowest service priority EndFor Uplink Load Factor Control UL
UL
For each cell (Sj,ic) with X S j ic X max Rejection of a mobile with the lowest service priority EndFor UL
UL
While at least one cell with X S j ic X max exists
5.4.2.1.3
Convergence Criterion The convergence criteria are evaluated at each iteration, and can be written as follow: DL DL P tx ic k – P tx ic k – 1 N user ic k – N user ic k – 1 DL = max int ma x ------------------------------------------------ 100 int ma x ----------------------------------------------------------- 100 DL Stations Stations P tx ic k N ic user
k
UL UL UL UL I tot ic k – I tot ic k – 1 N user ic k – N user ic k – 1 100 int ma x ----------------------------------------------------------- 100 UL = max int ma x -------------------------------------------------UL UL Stations Stations I ic N ic tot
k
user
k
Atoll stops the algorithm if: 1st case: Between two successive iterations, UL and DL are lower ( ) than their respective thresholds (defined when creating a simulation). The simulation has reached convergence. Example: Let us assume that the maximum number of iterations is 100, UL and DL convergence thresholds are set to 5. If UL 5 and DL 5 between the 4th and the 5th iteration, Atoll stops the algorithm after the 5th iteration. Convergence has been achieved. 2nd case: After 30 iterations, UL or/and DL are still higher than their respective thresholds and from the 30th iteration, UL or/and DL do not decrease during the next 15 successive iterations. The simulation has not reached convergence (specific divergence symbol). Examples: Let us assume that the maximum number of iterations is 100, UL and DL convergence thresholds are set to 5. 1. After the 30th iteration, UL and/or DL equal 100 and do not decrease during the next 15 successive iterations: Atoll stops the algorithm at the 46th iteration. Convergence has not been achieved. 2. After the 30th iteration, UL and/or DL equal 80, they start decreasing slowly until the 40th iteration (without going under the thresholds) and then do not change during the next 15 successive iterations: Atoll stops the algorithm at the 56th iteration without achieving convergence. 3rd case: After the last iteration. If UL and/or DL are still strictly higher than their respective thresholds, the simulation has not converged (specific divergence symbol). If UL and DL are lower than their respective thresholds, the simulation has converged.
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5.4.2.2 CDMA2000 1xEV-DO Power/Data Rate Control Simulation Algorithm
Figure 5.2: CDMA2000 1xEVDO Power Control Algorithm In a CDMA2000 1xEV-DO system, power control is performed in the uplink only. In the downlink, the transmitter transmits at the full power (Pmax) when a connection is established. Instead of power control, there is a data rate control based on the C/ I ratio calculated at the mobile. For each distribution of users, Atoll simulates the power control mechanism for the UL and the data rate control for the DL. The simulation uses an iterative algorithm, where in each iteration, all the 1xEV-DO data service users selected during the user distribution generation (1st step) try to connect to network active transmitters with a calculation area. Atoll considers the guaranteed bit rate service users first, in the order established during the generation of the user distribution, and then, it processes the variable bit rate service users, in the order established during the generation of the user distribution. The process is repeated from iteration to iteration until convergence is achieved. The algorithm steps are detailed below.
5.4.2.2.1
Algorithm Initialization UL
intra
Uplink received powers on carrier ic, I tot
UL
extra
ic , I tot
UL
ic and I inter – carrier ic , at base station Sj are initialised to 0 W
(no connected mobile). UL
I tot S j ic UL X k S j ic = ------------------------- = 0 UL N tot S j ic
5.4.2.2.2
Presentation of the Algorithm The algorithm is detailed for any iteration k. Xk is the value of the variable X at the iteration k. Ec In the algorithm, ----- is the minimum pilot quality level required in the uplink to operate 1xEV-DO Rev. 0. This N t min – Rev0 UL
threshold depends on the user mobility type and is defined in the Mobility parameters table. Ec --- N t min – RevB is the minimum pilot quality level required in the uplink to operate EV-DO multi-carrier. This threshold is UL
defined in the Transmitter properties dialogue. E UL For 1xEV-DO Rev. A and Rev. B users, the value of ----c- depends on the user requested throughput. This throughput can N t min be obtained by using a certain uplink 1xEV-DO radio bearer ( Index UL – Bearer ) in a certain number of subframes ( n SF ). Ec ---is the value defined in the 1xEV-DO Radio Bearer Selection (Uplink) table for the combination (radio bearer Index, N t min UL
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mobility and number of subframe) providing the user requested throughput. Two values are available for this parameter, one when the service uplink mode is "Low Latency" and another one for high capacity services. All variables are described in Definitions and formulas part (see "Definitions and Formulas" on page 340). The algorithm applies to single frequency band networks and to multi-band networks (dual-band and tri-band networks). Multi-band terminals can have the following configurations: • •
Configuration 1: The terminal can work on f1, f2 and f3 without any priority (select "All" as main frequency band in the terminal property dialogue). Configuration 2: The terminal can work on f1, f2 and f3 but f1 has a higher priority (select "f1" as main frequency band, "f2" as secondary frequency band and "f3" as third frequency band in the terminal property dialogue).
For each mobile (Mi), Atoll only considers the cells (Sj,ic) for which the pilot RSCP exceeds the minimum pilot RSCP: P c Sj M i ic b pilot RSCP min Sj ic . For each mobile Mi, we have the following steps: Determination of Mi’s Best Serving Cell For each transmitter Sj containing Mi in its calculation area and working on the main frequency band supported by the Mi’s terminal (i.e. either f1 for a single frequency band network, or f1, f2 or f3 for a multi-band terminal with the configuration 1, or f1 for a multi-band terminal with the configuration 2). BTS P c Sj M i ic ,b pilot Calculation of Q pilot Sj ic M i = -----------------------------------------------------------------------------------------------------------------------------------------------------------------Term k DL DL DL P tot Sj ic ,b pilot + I extra ic ,b pilot + I inter – carrier ic ,b pilot + N 0 Determination of the candidate cells, (SBS,ic). For each carrier ic, selection of the transmitter with the highest Q pilot Sj M i ic , S BS ic M i . k
Analysis of candidate cells, (SBS,ic). For each pair (SBS,ic), calculation of the uplink load factor: UL
I tot S BS ic UL UL X k S BS ic = ----------------------------+ X UL N tot S BS ic Rejection of bad candidate cells if the pilot is not received or if the uplink load factor is exceeded during the admission load control (if simulation respects a loading factor constraint and Mb was not connected in previous iteration) pilot
If Q pilot S BS M i ic Q req then (SBS,ic) is rejected by Mi k
UL
UL
If X k S BS ic X max , then (SBS,ic) is rejected by Mi Else Keep (SBS,ic) as good candidate cell For multi-band terminals with the configuration 1 or terminals working on one frequency band only, if no good candidate cell has been selected, Mi has failed to be connected to the network and is rejected. For multi-band terminals with the configuration 2, if no good candidate cell has been selected, try to connect Mi to transmitters txi containing Mi in their calculation area and working on the secondary frequency band supported by the Mi’s terminal (i.e. f2). If no good candidate cell has been selected, try to connect Mi to transmitters txi containing Mi in their calculation area and working on the third frequency band supported by the Mi’s terminal (i.e. f3). If no good candidate cell has been selected, Mi has failed to be connected to the network and is rejected. Determination of the best carrier, icBS. If a given carrier is specified for the service requested by Mi ic BS M i is the carrier specified for the service Else the carrier selection mode defined for the site equipment is considered. If carrier selection mode is “Min. UL Load Factor” UL
ic BS M i is the cell with the lowest X k S BS ic Else if carrier selection mode is “Min. DL Total Power”
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ic BS M i is the cell with the lowest P tx S BS ic k Else if carrier selection mode is “Random” ic BS M i is randomly selected Else if carrier selection mode is "Sequential" UL
UL
ic BS M i is the first carrier where X k S BS ic X max Endif Determination of the best serving cell, (SBS,icBS). max
(S BS,ic BS) k M i is the best serving cell ( BestCell k M i ) and its pilot quality is Q pilot M i . k
In the following lines, we will consider ic as the carrier used by the best serving cell. Determination of the Active Set For each station Sj containing Mi in its calculation area, using ic, and if neighbours are used, neighbour of SBS(Mi) DL
BTS P tot M i S j ic b pilot Calculation of Q pilot M i S j ic = ---------------------------------------------------------------------------DL k I 0 ic b pilot Rejection of station Sj if the pilot is not received min
If Q pilot M i S j ic Q pilot then Sj is rejected by Mi k
Else Sj is included in the Mi active set Rejection of Sj if the Mi active set is full Station with the lowest Q pilot in the active set is rejected k
EndFor Determination of the Sub-active Sets of a EVDO Multi-carrier User For multi-carrier EV-DO Rev.B service users with a 1xEV-DO Rev. B capable terminal, calculation of the quality level received by the best serving cell (SBS,ic) Ec --- N t
UL
max
term P term M i S BS ic = -----------------------------------------UL L T N tot S BS ic
E c UL E c UL If ----- S BS ic ----- S BS then EV-DO multi-carrier is not activated. Nt N t min For each transmitter Sj containing Mi in its calculation area and using other EV-DO carriers, icn (either icn belongs to f1 for a single frequency band network, or it belongs to f1, f2 or f3 for a multi-band terminal) Calculation of Q pilot Sj ic n M i k
Ranking of carriers, icn,according to Q pilot Sj ic n M i , from the highest to the lowest value. k
For each received carrier, icn, in the defined order: carriers
While n max
M i is not exceeded
Determination of the best transmitter of the sub-active set, based on the received pilot quality, Q pilot Sj ic n M i . k
Determination of the other transmitters of the sub-active set, based on the received pilot quality, Q pilot Sj ic n M i . k
Calculation of the quality level received by the best serving cell (SBS,icn) Ec --- N t
UL
max
term P term M i S BS ic n = -----------------------------------------UL L T N tot S BS ic n
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UL
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E UL S BS ic n ----c- S BS , then no sub-active set is associated with icn N t min
If the user terminal supports the ’Locked’ mode, analysis of the sub-active set If a transmitter of the studied sub-active set does not belong to the sub-active set associated with the best carrier, then it is removed. If the studied sub-active set does not contain the same transmitters as the sub-active set associated with the best carrier, then the studied sub-active set is removed. EndIf Endwhile EndFor Uplink Power Control req
Calculation of the required power for Mi, P term M i ic k For each cell (Sj,ic) present in the Mi active set or sub-active set Calculation of quality level on Mi traffic channel at (Sj,ic), with the minimum power allowed on traffic channel for the Mi service req
P term M i ic k – 1 UL P b M i S j ic = --------------------------------------L T M i S j UL
term P b M i S j ic UL - G UL Q M i S j ic k = -------------------------------------------------------------------------------------------------------------p Service UL Tx UL N tot ic – 1 – F MUD term P b M i S j ic If the user selects the option “Total noise” UL
term P b M i S j ic UL - G UL Q M i S j ic k = ---------------------------------------------------p Service UL N tot ic End For If (Mi is not in handoff) UL
UL
Q total M i = Q M i S j ic k
Else if (Mi is in softer handoff) UL
UL
Q total M i = f rake efficiency k
UL
Q M i S j ic k
S j ActiveSet
Else if (Mi is in soft or softer/soft without MRC) UL
UL
Q total M i = k
UL
Max Q M i S j ic k G macro – diversity 2 links
I AS ActiveSet
Else if (Mi is in soft/soft) UL
UL
Q total M i = k
I
UL
Max Q M i S j ic k G macro – diversity 3 links
AS
ActiveSet
Else if (Mi is in softer/soft with MRC) UL UL UL UL Q total M i = Max f rake efficiency Q M i S j ic k Q M i S j ic k k othersite i AS ActiveSet
(same site)
G UL macro – diversity 2 links
EndIf UL
Q req Service M i Term M i Mobility M i req - P req P term M i ic k = --------------------------------------------------------------------------------------------------------------term M i ic k – 1 UL Q total M i k
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If the service of Mi uses Transmission Control Protocol (TCP) For the best server cell (Sk,ic) of Mi Calculation of the Mi downlink application throughput DL
Calculation of N tot ic b traffic
Ptot txj icadj btraffic DL
DL
txj j - + N0 Ptot Sj i c btraffic + ---------------------------------------------------------------RF ic ic adj DL
N tot ic b traffic =
term
j j k
Calculation of the maximum throughput supplied to Mi, TP max – DL M i S k Calculation of pilot quality level at Mi DL E P tot M i S k ic b pilot ----c- M i S k ic b pilot = -------------------------------------------------DL Nt N tot ic b pilot
If Mi is a 1xEV-DO Rev. 0 service user, determination of the peak throughput from the graph (Peak throughput=f(C/I)) specified for the mobility type of Mi E TP max – DL M i S k = f ----c- M i S k ic b pilot Nt If Mi is a 1xEV-DO Rev. A service user, selection of the downlink 1xEV-DO radio bearer ( Index DL – Bearer ): Index DL – Bearer DL Ec Ec where ----- M i S k ic b pilot ----- Index DL – Bearer Nt Nt min
If Mi is a 1xEV-DO Rev. B service user, selection of the downlink 1xEV-DO radio bearer ( Index DL – Bearer ): Index DL – Bearer DL E E where ----c- M i S k ic b pilot ----c- Index DL – Bearer and the modulation scheme is supported by the terminal. Nt min Nt DL
TP P – R LC Index DL – Bearer Determination of the peak throughput: TP max – DL M i S k = -----------------------------------------------------------n TS Index DL – Bearer DL
TP A M i S k = TP max – DL M i S k f TP – Scaling Service Mi – TP Offset Service Mi UL
Determination of the uplink throughput due to TCP acknowledgements, TP TCP – ACK M i S k from the graph (UL Thr due to TCP=f(DL Thr) specified for the service of Mi UL
DL
TP TCP – ACK M i S k = f TP A M i S k UL
UL
UL
Determination of the nearest lower and higher supported throughputs ( TP low and TPhigh ) for TP TCP – ACK M i S k UL
UL
UL
UL
UL
UL
For TPlow and TP high , calculation of CI req TP low and CI req TP high E UL CI req = ----c- 1 + G DRC + G TCH for DO Rev.0 terminals N t min UL
And E UL UL CI req = ----c- 1 + G DRC + G TCH + G RRI + G Auxiliary – pilot for DO Rev.A and DO Rev.B terminals N t min EndFor UL
UL
UL
UL
UL
UL
UL
UL
Linear interpolation of CI req TP TCP – ACK between CI req TP low and CI req TP high UL
UL
UL
CI req = CI req TP + CI req TP TCP – ACK W UL UL Q req = CI req ----------------------------------------------UL UL TP + TPTCP – ACK EndIf
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req
min
P term M i ic k = Max P term M i ic k P term M i S j For DO Rev.0 and DO Rev.A users req
max
If P term M i ic k P term M i then: Downgrading the traffic channel throughput req
max
While P term M i ic k P term M i And UL
TP Service M i 9.6kbps for 1xEV-DO Rev. 0 users, UL
TP Service M i 4.8kbps for (1xEV-DO Rev. A - Variable bit rate) service users, UL
TP Service M i 4.8kbps for single-carrier 1xEV-DO Rev. B service users, UL
TP Service M i TPD min – UL Service M i for (1xEV-DO Rev. A - Guaranteed bit rate) service users, req
P term M i ic k req - TP UL P term M i ic k = ---------------------------------------------low Service M i UL TP Service M i
UL
( TP low Service M i
is the nearest lower supported
throughput) For 1xEV-DO Rev. 0, (1xEV-DO Rev. A - Variable bit rate) and single-carrier 1xEV-DO Rev. B service users, UL
UL
TP Service M i = TP low Service M i UL
For (1xEV-DO Rev. A - Guaranteed bit rate) service users, TP Service M i = TPD min – UL Service M i EndWhile req
max
If P term M i ic k P term M i then Mi is rejected For 1xEV-DO Rev. 0, (1xEV-DO Rev. A - Variable bit rate) and single-carrier 1xEV-DO Rev. B service users, req
P term M i ic = P term M i ic k req
For (1xEV-DO Rev. A - Guaranteed bit rate) service users, P term M i ic = P term M i ic k C UL – Bearer Endif Endif For multi-carrier 1xEV-DO Rev. B service users, load balancing between carriers is performed. The available terminal power is shared between each carrier as follows: The maximum terminal power is allocated to the best carrier ( ic 1 ). UL
Calculation of the traffic channel throughput ( TP Service M i ic 1 ) UL
Downgrading the traffic channel throughput ( TP Service M i ic 1 )
While
req
max
P term M i ic 1 k P term M i
UL
and TP Service M i ic 1 153 6kbps
req
P term M i ic 1 k req UL - TP UL P term M i ic 1 k = ------------------------------------------------------------low Service M i ( TP low Service M i is the nearest lower supported UL TP Service M i ic 1 throughput) UL
UL
TP Service M i ic 1 = TP low Service M i EndWhile req
max
If P term M i ic 1 k P term M i , then Mi is not connected to cells of the sub-active set associated with ic 1 .
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Else the remaining terminal power is allocated to the second best carrier ( ic 2 ) and the traffic channel throughput UL
TP Service M i ic 2 is calculated. The same process is repeated for the other carriers in Mi ’s active set as long as the remaining terminal power is sufficient to obtain the lowest bearer allowed. If no sub-active set can be used, then Mi is rejected. Endif UL
Calculation of TP Service M i for each combination of carriers n UL
TP Service M i =
TP
UL
Service M i ic where n corresponds to the number of carriers in the combination.
ic = 1 UL
Selection of the configuration providing the highest throughput, Max TP Service M i . UL
UL
UL
If Max TP Service M i TP high Service M i ( TP high Service M i is the nearest supported throughput higher than the requested throughput) Downgrading the traffic channel throughput UL
UL
UL
While Max TP Service M i TP high Service M i and TP Service M i ic 153 6kbps EndWhile EndIf Endfor Uplink Interference Updates Update of interference on active mobiles only (old contributions of mobiles and stations are replaced by the new ones) For each cell (Sj,ic) UL
Update of N tot S j ic EndFor Control of Radio Resource Limits (Number of EVDO users, MAC Indices and Site Channel Elements) For each cell (Sj,ic) Max
While n EVDO S j ic n EVDO S j ic Rejection of the last admitted mobile EndFor For each cell (Sj,ic) Max
While N MacIndexes S j ic N MacIndexes S j ic Rejection of the last admitted mobile EndFor For each site (Node B) Nl Max
While N EVDO – CE N I k N EVDO – CE N I Rejection of the last admitted mobile EndFor Uplink Load Factor Control UL
UL
UL
For each cell (Sj,ic) with NR S j ic NR threshold S j ic + NRthreshold S j ic UL
UL
UL
While NR S j ic NR threshold S j ic + NRthreshold S j ic and there is at least one mobile that can be downgraded
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Downgrading the traffic channel throughput for all 1xEV-DO Rev. 0 mobiles for which the throughput transition flag is set to "True". UL
Update of N tot S j ic Endwhile UL
UL
UL
For each cell (Sj,ic) with NR S j ic NR threshold S j ic – NRthreshold S j ic UL
UL
UL
While NR S j ic NR threshold S j ic – NRthreshold S j ic and there is at least one mobile that can be upgraded Upgrading the traffic channel throughput for all 1xEV-DO Rev. 0 mobiles for which the throughput transition flag is set to "True". (only 1xEV-DO Rev. 0 mobiles which have not been downgraded can be upgraded. In addition, the upgraded throughput cannot exceed the initial user throughput drawn by the Monte-Carlo algorithm. This means that only mobiles downgraded during the uplink power control step can be upgraded). UL
Update of N tot S j ic Endwhile UL
UL
For each cell (Sj,ic) with X S j ic X max Rejection of a mobile with the lowest service priority EndFor UL
UL
While at least one cell with X S j ic X max exists Downlink Data Rate Control For each mobile Mi connected to a cell (Sk,ic) DL
Calculation of N tot ic b traffic For each cell (Sj,ic) ( k j ) Determination of the number of mobiles connected to the cell (Sj,ic), N mobiles S j ic If N mobiles S j ic = 0 then, P tx S j ic b traffic = G idle – power P max S j ic Else P tx S j ic b traffic = P max S j ic EndFor DL
N tot ic b traffic =
Ptot Sj ic btraffic + N0 DL
term
j j k
EndFor Calculation of the maximum throughput supplied to Mi, TP max – DL For the Mi’s best server cell (Sk,ic) (in the active set or each sub-active set) Calculation of pilot quality level at Mi DL E P tot M i S k ic b pilot ----c- M i S k ic b pilot = -------------------------------------------------DL Nt N tot ic b pilot
If Mi is a 1xEV-DO Rev. 0 service user, determination of the peak throughput from the graph (Peak throughput=f(C/I)) specified for the mobility type of Mi E TP max – DL M i S k = f ----c- M i S k ic b pilot Nt If Mi is a 1xEV-DO Rev. A service user, selection of the downlink 1xEV-DO radio bearer ( Index DL – Bearer ) for which DL E E ----c- M i S k ic b pilot ----c- Index DL – Bearer Nt Nt min
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If Mi is a 1xEV-DO Rev. B service user, selection of the downlink 1xEV-DO radio bearer ( Index DL – Bearer ) for which DL E E ----c- M i S k ic b pilot ----c- Index DL – Bearer and the modulation is supported by Mi’s terminal. Nt min Nt DL
If Mi is a (1xEV-DO Rev. A - Guaranteed bit rate) service user and TP P – R LC Index DL – Bearer TPD min – DL Service M i , Mi is rejected. DL
TP P –R LC Index DL – Bearer Determination of the peak throughput: TP max – DL M i S k ic = -----------------------------------------------------------n TS For 1xEV-DO Rev. 0, (1xEV-DO Rev. A - Variable bit rate) and single-carrier 1xEV-DO Rev. B service users, TP max – DL M i = TP max – DL M i S k ic For (1xEV-DO Rev. A - Guaranteed bit rate) service users, TP max – DL M i = TPD min – DL Service M i For multi-carrier 1xEV-DO Rev. B service users, TP max – DL M i =
DL
TP max – DL max M i S k ic
S k ic
For (1xEV-DO Rev. A - Guaranteed bit rate) service users, calculation of C DL – Bearer EndFor DL
Calculation of the average cell throughput, TP av For each cell (Sj,ic)
G MU N mobiles S j ic TP max – DL M i S j ic Mi NVBR –m obiles Sj ic ---------------------------------------------------------------------------------------C DL – Bearer M k S j ic 1 – N VBR –m obiles S j ic M k N GBR – m obiles Sj ic
DL
TP av S j ic =
TPD min – DL M k Mk NGBR – m obiles Sj ic + --------------------------------------------------------------------------------------------- C DL – Bearer M k S j ic N S ic GBR – m obiles j M N S ic k GBR – m obiles j
1 – ER S ic DRC j
N mobiles
1 – TS BCMCS S j ic – TS EVDO – CCH S j ic + TP BCMCS S j ic TS BCMCS S j ic
If N mobiles S j ic = 1 , then G MU = 1 Else if N mobiles S j ic 1 , G MU is determined from the graph (MUG table=f(nb users)) specified for (Sj,ic). If the transmitter supports the multi-carrier EV-DO mode, G MU is determined from the graph (MUG table=f(nb users)) specified for Sj. EndIf EndFor
5.4.2.2.3
Convergence Criterion The algorithm convergence is studied on uplink only. The uplink convergence criterion is evaluated at each iteration, and can be written as follow: UL UL UL UL I tot ic k – I tot ic k – 1 N user ic k – N user ic k – 1 UL = max int ma x ------------------------------------------------- 100 int ma x ----------------------------------------------------------- 100 UL UL Stations Stations I ic N ic tot
k
user
k
Atoll stops the algorithm if: 1st case: Between two successive iterations, UL is lower ( ) than the threshold (defined when creating a simulation). The simulation has reached convergence. Example: Let us assume that the maximum number of iterations is 100, UL convergence threshold is set to 5. If UL 5 between the 4th and the 5th iteration, Atoll stops the algorithm after the 5th iteration. Convergence has been achieved.
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2nd case: After 30 iterations, UL is still higher than the threshold and from the 30th iteration, UL does not decrease during the next 15 successive iterations. The simulation has not reached convergence (specific divergence symbol). Examples: Let us assume that the maximum number of iterations is 100, UL convergence threshold is set to 5. 1. After the 30th iteration, UL equals 100 and do not decrease during the next 15 successive iterations: Atoll stops the algorithm at the 46th iteration. Convergence has not been achieved. 2. After the 30th iteration, UL equals 80, it starts decreasing slowly until the 40th iteration (without going under the threshold) and then does not change during the next 15 successive iterations: Atoll stops the algorithm at the 56th iteration without achieving convergence. 3rd case: After the last iteration. If UL is still strictly higher than the threshold, the simulation has not converged (specific divergence symbol). If UL is lower than the threshold, the simulation has converged.
5.4.3 Appendices 5.4.3.1 Admission Control During admission control, Atoll calculates the uplink load factor of a considered cell assuming the mobile concerned is connected with it. Here, activity status assigned to users is not taken into account. So even if the mobile is not active on UL, it can be rejected due to cell load saturation. To calculate the cell UL load factor, either Atoll takes into account the mobile power determined during power control if mobile was connected in previous iteration, or it estimates a load rise due to the mobile and adds it to the current load. The load rise ( X X
UL
UL
) is calculated as follows:
1 = ------------------------------------W 1 + --------------------------UL UL Q req TP
In case of CDMA2000 1xRTT networks, we have: UL
UL
UL
Q req = Q req FCH + Q req SCH and TP
UL
FCH
SCH
= TP P – UL + TP P – UL
5.4.3.2 Resources Management 5.4.3.2.1
Walsh Code Management Walsh codes are managed in the downlink during the simulation in case of CDMA2000 1xRTT networks. Atoll performs Walsh code allocation during the radio resource control step. Walsh codes form a binary tree with codes of a longer length generated from codes of a shorter length. Length-k Walsh codes are generated from length-k/2 Walsh codes. Therefore, if a channel needs 1 length-k/2 Walsh code, it is equivalent to using 2 length-k Walsh codes, or 4 length-2k Walsh codes and so on.
Figure 5.3: Walsh Code Tree Indices (Not Walsh Code Numbers) 128 128-bit-length Walsh codes per cell are available in CDMA2000 documents.
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During the resource control, Atoll determines the number of 128-bit-length Walsh codes that will be consumed by each cell. Therefore, it allocates : •
• •
A code with the longest length (i.e. a 128 bit-length code) per common channel for each cell. The number of common channels per cell corresponds to the value defined for the DL overhead resources for common channels per cell parameter available in the site equipment properties. Two 128 bit-length codes per cell-receiver link for FCH in RC1, RC2, RC3 or RC5 and only one for FCH in RC4. The number of 128 bit-length codes to be allocated per cell-receiver link for SCH (in case SCH is supported by the user Walsh codes
radio configuration), N 128 bits Walsh codes
N 128 bits
, is determined as follows:
SCH
= TPF DL 2 for RC1, RC2, RC3 and RC5,
And Walsh codes
N 128 bits
SCH
= TPF DL for RC4.
Where SCH
TPF DL
is the SCH throughput factor.
The Walsh code allocation follows the “Buddy” algorithm, which guarantees that: • •
If a k-length Walsh code is used, all of its children with lengths 2k, 4k, …, cannot be used as they are not orthogonal. If a k-length Walsh code is used, all of its ancestors with lengths k/2, k/4, …, cannot be used as they are not orthogonal. • •
5.4.3.2.2
The Walsh code allocation follows the mobile connection order (mobile order in the Mobiles tab). The Walsh code and channel element management is dealt with differently in case of “softer” handoff. Atoll allocates Walsh codes for each transmitter-receiver link while it assigns channel elements globally to a site.
Channel Element Management Channel elements are controlled in the simulation. CDMA2000 1xRTT networks Atoll checks the availability of this resource on uplink and downlink. On uplink, Atoll consumes N CE – UL j channel elements for each cell j on a site NI. This figure includes: Overhead
•
N CE – UL
•
FCH N CE – UL
channel elements for control channels (Pilot channel), SCH
1 + TPF UL per cell-receiver link, for TCH (TCH correspond to Traffic channels i.e. FCH and SCH).
Therefore, the number of channel elements required on uplink at the site level, N CE – UL N I , is: N CE – UL N I =
NCE – UL j
j NI
In the downlink, Atoll consumes N CE – DL j channel elements for each cell j on a site NI. This figure includes: Overhead
•
N CE – DL
•
FCH N CE – DL
channel elements for control channels (Pilot channel, Synchronisation channel, Paging channel), SCH
1 + TPF DL per cell-receiver link, for TCH (TCH correspond to Traffic channels i.e. FCH and SCH).
Therefore, the number of channel elements required on downlink at the site level, N CE – DL N I , is: N CE – DL N I =
NCE – DL j
j NI
In case of “softer” handover (the mobile has several links with co-site cells), Atoll allocates channel elements for the best serving cell-mobile link only.
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CDMA2000 1xEV-DO networks In the uplink, Atoll consumes N CE – UL j channel elements for each cell j on a site NI. This figure includes: •
2 channel elements for control channels (Pilot channel, Data Rate Control channel, etc ). This value is fixed and hardcoded.
•
N CE – UL per cell-receiver link, for (EV-DO - Variable bit rate) service users.
•
N CE – UL C UL – Bearer per cell-receiver link, for (EV-DO - Guaranteed bit rate) service users.
TCH TCH
Therefore, the number of channel elements required on uplink at the site level, N CE – UL N I , is: N CE – UL N I =
NCE – UL j
j NI
In the downlink, only one user can be served by a cell at a time, so this resource is not limited.
5.4.3.3 Downlink Load Factor Calculation Atoll calculates the downlink load factor for each cell (available in the Cells tab of any given simulation results) and each connected mobile (available in the Mobiles tab of any given simulation results).
5.4.3.3.1
Downlink Load Factor per Cell The downlink load factor is calculated for each CDMA2000 1xRTT cell. Approach for downlink load factor evaluation is highly inspired by the downlink load factor defined in the book “WCDMA for UMTS by Harry Holma and Antti Toskala”. DL – FCH
DL – SCH
Q req Q req + -------------------Let CI req = -------------------be the required quality. DL – FCH DL – SCH Gp Gp FCH
SCH
So, we have CI req = CI req + CI req
In case of soft handoff, required quality is limited to the effective contribution of the transmitter. DL
ortho
P tx ic = P pilot ic + P sync ic + P paging ic + P SCH ic + P FCH ic = P CCH ic +
Ptch ic tch
where ortho
P CCH ic = P pilot ic + P sync ic + P paging ic
Ptch ic
= P SCH ic + P FCH ic
tch
At mobile level, we have a required power, Ptch: term
P tch ic = CI req I extra ic + I intra ic + I inter – carrier ic + I inter – techno log y ic + N 0 P tch ic = CI req
I extra ic + I inter – carrier ic + I inter – techno log y ic DL
P tx ic – P tch ic - + N term + 1 – F ortho BTS ----------------------------------------0 LT
LT
L T DL
term
I extra ic + I inter – carrier ic + I inter – techno log y ic L T + 1 – F ortho BTS P tx ic + N 0 L T P tch ic = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------1 ----------- + 1 – F ortho BTS CIreq where DL
I intra ic is the total power received at receiver from the cell to which it is connected. DL
I extra ic is the total power received at receiver from other cells. I inter – carrier ic is the inter-carrier interference received at receiver.
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I inter – techno log y ic is the inter-technology interference received at receiver. I ic + I inter – carrier ic + I inter – techno log y ic L T extra DL term 1 F + – P ic + N L ortho BTS tx 0 T DL ortho P tx ic = P CCH ic + -------------------------------------------------------------------------------------------------------------------------------------------------- 1 ----------- + 1 – F ortho BTS tch CI req
We have: I extra ic + I inter – carrier ic + I inter – techno log y ic L T --------------------------------------------------------------------------------------------------------------------------------------DL P tx ic DL term 1 F + – P ic + N L ortho BTS tx 0 T DL ortho ------------------------------------------------------------------------------------------------------------------------------------------------- P tx ic = P CCH ic + 1 - + 1 – F --------- ortho BTS tch CI req
I extra ic + I inter – carrier ic + I inter – techno log y ic L T --------------------------------------------------------------------------------------------------------------------------------------+ 1 – F ortho BTS DL P tx ic tch DL DL P tx ic – --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- P tx ic 1 ----------- + 1 – F ortho BTS CI req
ortho = P CCH ic +
term N0 LT --------------------------------------------------------------- 1 tch ----------- + 1 – F ortho BTS CI req
term ortho N0 LT -------------------------------------------------------------- P CCH ic + 1 tch ----------- + 1 – F ortho BTS CI req DL P tx ic = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ I extra ic + I inter – carrier ic + I inter – techno log y ic L T --------------------------------------------------------------------------------------------------------------------------------------- + 1 – F ortho BTS DL P tx ic 1 – ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 1 ----------- + 1 – F ortho BTS tch CI req
Therefore, the downlink load factor can be expressed as:
X
DL
I extra ic + I inter – carrier ic + I inter – techno log y ic L T --------------------------------------------------------------------------------------------------------------------------------------+ 1 – F ortho BTS DL P ic tx -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- = 1 - + 1 – F --------- ortho BTS tch CI req
The downlink load factor represents the signal degradation in relative to the reference interference (thermal noise).
5.4.3.3.2
Downlink Load Factor per Mobile Atoll evaluates the downlink load factor for any connected mobile (CDMA2000 1xRTT 1xEV-DO user) as follows, X
DL
DL
I tot ic = -----------------DL N tot ic
5.4.3.4 Best Server Determination in Monte Carlo Simulations - Old Method Before Atoll 2.8.0, best server determination used to be performed by selecting the best carrier within transmitters according to the selected method (site equipment) and then the best transmitter using the best carrier. To switch back to this method, add the following lines in the Atoll.ini file: [CDMA]
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MultiBandSimu = 0 The method is described below: For each station Sj containing Mi in its calculation area and using the main frequency band supported by the Mi’s terminal (i.e. either f1 for a single frequency band network, or f1, f2 or f3 for a multi-band terminal without any priority on frequency bands, or f1 for a multi-band terminal with f1 as main frequency band). Determination of BestCarrier k S j M i . If a given carrier is specified for the service requested by Mi and if it is used by Sj BestCarrier k S j M i is the carrier specified for the service. Else the carrier selection mode defined for Sj is considered. If carrier selection mode is “Min. UL Load Factor” For each carrier ic used by Sj, we calculate current loading factor: UL
I tot S j ic UL UL X k S j ic = ------------------------- + X UL N tot S j ic EndFor UL
BestCarrier k S j M i is the carrier with the lowest X k S j ic Else if carrier selection mode is “Min. DL Total Power” BestCarrier k S j M i is the carrier with the lowest P tx S j ic k Else if carrier selection mode is “Random” BestCarrier k S j M i is randomly selected Else if carrier selection mode is "Sequential" UL
UL
BestCarrier k S j M i is the first carrier so that X k S j ic X max BTS P c M i S j BestCarrier Calculation of Q pilot M i S j BestCarrier = ----------------------------------------------------------------------------------DL k I 0 BestCarrier k S j M i Rejection of station Sj if the pilot is not received pilot
If Q pilot M i S j BestCarrier Q req then Sj is rejected by Mi k
max
If Q pilot M i S j BestCarrier Q pilot M i k
k
Admission control (If simulation respects a load factor constraint and Mi was not connected in previous iteration). UL
UL
If X k S j BestCarrier k S j M i X max , then Sj is rejected by Mi Else max
Q pilot M i = Q pilot M i S j BestCarrier k
k
S BS M i = S j Endif EndFor If no SBS has been selected and Mi’s terminal can work on one frequency band only, Mi has failed to be connected to the network and is rejected. If no SBS has been selected and Mi’s terminal can work on another frequency band. Determination of BestCarrier k Sj M i for each station txj containing Mi in its calculation area and using another frequency band supported by the Mi’s terminal (i.e. f1, f2 or f3 for a multi-band terminal without any priority on frequency bands, or f2 for a multi-band terminal with f2 as secondary frequency band) If a given carrier is specified for the service requested by Mi and if it is used by Sj
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BestCarrier k S j M i is the carrier specified for the service. Else the carrier selection mode defined for Sj is considered. If carrier selection mode is “Min. UL Load Factor” For each carrier ic used by Sj, we calculate current loading factor: UL
I tot S j ic UL UL - + X X k S j ic = ------------------------UL N tot S j ic EndFor UL
BestCarrier k S j M i is the carrier with the lowest X k S j ic Else if carrier selection mode is “Min. DL Total Power” BestCarrier k S j M i is the carrier with the lowest P tx S j ic k Else if carrier selection mode is “Random” BestCarrier k S j M i is randomly selected Else if carrier selection mode is "Sequential" UL
UL
BestCarrier k S j M i is the first carrier so that X k S j ic X max BTS P c M i S j BestCarrier Calculation of Q pilot M i S j BestCarrier = ----------------------------------------------------------------------------------DL k I 0 BestCarrier k S j M i Rejection of station Sj if the pilot is not received pilot
If Q pilot M i S j BestCarrier Q req then Sj is rejected by Mi k
max
If Q pilot M i S j BestCarrier Q pilot M i k
k
Admission control (If simulation respects a load factor constraint and Mi was not connected in previous iteration). UL
UL
If X k S j BestCarrier k S j M i X max , then Sj is rejected by Mi Else max
Q pilot M i = Q pilot M i S j BestCarrier k
k
S BS M i = S j Endif EndFor If no SBS has been selected and Mi’s terminal can work on two frequency bands only, Mi has failed to be connected to the network and is rejected. If no SBS has been selected and Mi’s terminal can work on another frequency band. Determination of BestCarrier k Sj M i for each station txj containing Mi in its calculation area and using another frequency band supported by the Mi’s terminal (i.e. f1, f2 or f3 for a multi-band terminal without any priority on frequency bands, or f3 for a multi-band terminal with f3 as third frequency band) If a given carrier is specified for the service requested by Mi and if it is used by Sj BestCarrier k S j M i is the carrier specified for the service. Else the carrier selection mode defined for Sj is considered. If carrier selection mode is “Min. UL Load Factor” For each carrier ic used by Sj, we calculate current loading factor: UL
I tot S j ic UL UL X k S j ic = ------------------------- + X UL N tot S j ic
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EndFor UL
BestCarrier k S j M i is the carrier with the lowest X k S j ic Else if carrier selection mode is “Min. DL Total Power” BestCarrier k S j M i is the carrier with the lowest P tx S j ic k Else if carrier selection mode is “Random” BestCarrier k S j M i is randomly selected Else if carrier selection mode is "Sequential" UL
UL
BestCarrier k S j M i is the first carrier so that X k S j ic X max BTS P c M i S j BestCarrier Calculation of Q pilot M i S j BestCarrier = ----------------------------------------------------------------------------------DL k I 0 BestCarrier k S j M i Rejection of station Sj if the pilot is not received pilot
If Q pilot M i S j BestCarrier Q req then Sj is rejected by Mi k
max
If Q pilot M i S j BestCarrier Q pilot M i k
k
Admission control (If simulation respects a load factor constraint and Mi was not connected in previous iteration). UL
UL
If X k S j BestCarrier k S j M i X max , then Sj is rejected by Mi Else max
Q pilot M i = Q pilot M i S j BestCarrier k
k
S BS M i = S j Endif EndFor If no SBS has been selected, Mi has failed to be connected to the network and is rejected.
5.4.3.5 Radio Bearer Allocation Algorithm for Multi-carrier EVDO Rev.B - Old Method Before Atoll 3.2.1, radio bearer allocation for multi-carrier EVDO Rev.B used to be performed by equally sharing the available terminal power between the carriers. To switch back to this method, add the following lines in the Atoll.ini file: [CDMA] SharingEquallyPower = 1 UsingPreviousIterationPowerWeight = 1
5.5 CDMA2000 Prediction Studies 5.5.1 Point Analysis: The AS Analysis Tab Let us assume a receiver with a terminal, a mobility type and a service with certain UL and DL throughputs. This receiver does not create any interference. You can make the prediction for a specific carrier or for the best 1xRTT or 1xEV-DO carrier. The type of carrier and the carriers you can select depend on the service and on the frequency band(s) supported by the terminal. The analysis is based on the uplink load percentage and the downlink total power of cells. These parameters can be either outputs of a given simulation, average values calculated from a group of simulations, or user-defined cell inputs. Results are displayed for any point of the map where the pilot signal level exceeds the defined minimum RSCP.
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5.5.1.1 Bar Graph and Pilot Sub-Menu We can consider the following cases: 1st case: Analysis based on a specific carrier The carrier that can be used by transmitters is fixed. In this case, for each transmitter i containing the receiver in its calculation area and using the selected carrier, Atoll calculates the pilot quality at the receiver on this carrier. Then, it determines the best serving transmitter using the selected carrier ic. 2nd case: Analysis based on the best carrier of all frequency bands Atoll determines the best carrier for each transmitter i which contains the receiver in its calculation area and uses a frequency band supported by the receiver’s terminal. The best carrier selection depends on the option selected for the site equipment (UL minimum noise, DL minimum power, random, sequential). Then, Atoll calculates the pilot quality at the receiver from these transmitters on their best carriers (ic) and defines the best server (on its best carrier). 3rd case: Analysis based on the best carrier of any frequency band (for multi-band terminals with priority defined on frequency bands only) The frequency band that can be used is fixed. Atoll determines the best carrier for each transmitter i containing the receiver in its calculation area and using the selected frequency band. The best carrier selection depends on the option selected for the site equipment (UL minimum noise, DL minimum power, random, sequential). Then, Atoll calculates the pilot quality at the receiver from these transmitters on their best carriers (ic) and defines the best server (on its best carrier). Atoll provides the same outputs in the bar graph and pilot sub-menu whichever the studied network, CDMA2000 1xRTT or 1xEV-DO. •
Ec/I0 (or Q pilot ic ) evaluation
We assume that ic is the best carrier of a transmitter i containing the receiver in its calculation radius. For CDMA2000 1xRTT users we have, BTS P c i ic Q pilot i ic = --------------------------------------------DL I 0 ic DL
DL
DL
DL
term
DL
with I 0 ic = P tot i ic + I extra ic + I inter – carrier ic + I inter – techno log y ic + N 0 For CDMA2000 1xEV-DO users, we have, DL
BTS P tot i ic b pilot Q pilot i ic = ---------------------------------------------------------------DL I 0 ic b pilot DL
DL
DL
DL
DL
term
With I 0 ic b pilot = P tot i ic b pilot + I extra ic b pilot + I inter – carrier ic b pilot + I inter – techno log y ic + N 0 The calculation of Q pilot i ic can be divided into 6 steps explained in the table below. CDMA2000 1xRTT users
CDMA2000 1xEV-DO users DL
P tot i ic b pilot calculation for each cell (i,ic) P c i ic calculation for each cell (i,ic) P c i ic is the pilot power from a transmitter i on the carrier ic at
DL
P tot i ic b pilot is the pilot burst from the transmitter i on the carrier ic at the receiver.
1st step
the receiver. P pilot i ic P c i ic = ------------------------LT I
P tx i ic b pilot DL P tot i ic b pilot = ----------------------------------LT I
and P tx i ic b pilot = P max i ic
L path L Tx L term L body L indoor M Shadowing – Ec Io L T is the total loss between the transmitter i and the receiver: ------------------------------------------------------------------------------------------------------------------------------------I G Tx G term
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CDMA2000 1xRTT users DL
DL
CDMA2000 1xEV-DO users
DL
I extra ic , I inter – carrier ic and I inter – techno log y ic calculation We have, DL
I extra ic =
Ptot j ic DL
DL
DL
I extra ic b pilot and I inter – carrier ic b pilot calculation
j j i
DL
2nd step
For each transmitter of the network, P tot j ic is the total power
We have,
received at the receiver from the transmitter j on the best carrier ic of the transmitter i. P tx j ic DL P tot j ic = -------------------LT
DL
Ptot j ic bpilot DL
I extra ic b pilot =
j j i
Ptot j icadj bpilot DL
P tx j ic is the total power transmitted by the transmitter j on the DL
best carrier of the transmitter i.
j j I inter – carrier ic b pilot = ---------------------------------------------------RF ic ic adj
Finally, we have,
and
Ptot j icadj DL
DL
DL
I inter – techno log y ic =
j I inter – carrier ic = j-----------------------------------RF ic ic adj
ni
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic i
and DL
I inter – techno log y ic =
n
i
Tx
P Transmitted ic i -------------------------------------Tx Tx m L total ICP ic ic i
3rd step
term
N0
calculation Tx DL
4th step
NF Term K T W NR inter – techno log y DL
I 0 ic and Q pilot i ic evaluation based on formulas defined above DL
G macro – diversity calculation DL
The macro-diversity gain, G macro – diversity , models the decrease in shadowing margin due to the fact there are several pilot signals at the 5th step
mobile. DL G macro – diversity
=
npaths M Shadowing – Ec Io
– M Shadowing –Ec Io
npaths
M Shadowing – Ec Io is the shadowing margin for the mobile receiving n pilot signals (not necessarily from transmitters belonging to the mobile active set). Note: This parameter is determined from the fixed cell edge coverage probability and the model standard deviation. When the model standard deviation is set to 0, the macro-diversity gain equals 0.
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CDMA2000 1xRTT users
CDMA2000 1xEV-DO users
Determination of active set Atoll takes the transmitter i with the highest Q pilot i ic and calculates the best pilot quality received with a fixed cell edge coverage Resulting
probability Q pilot Resulting Q pilot ic Resulting
Q pilot
=
DL G macro – diversity
req
ic .
max Q pilot i ic Resulting
Q pilot means that the pilot quality at the receiver exceeds Q pilot
ic x% of times (x is the fixed cell edge coverage
probability). The cell with the highest Q pilot i ic enters the active set as best server ( Q pilot BS ic ) and the best carrier (icBS) of the 6th step
best server BS will be the one used by other transmitters of active set (when active set size is greater than 1). Pilot is available. Resulting
If Q pilot
req
ic Q pilot , no cell (i,ic) can enter the active set. Pilot is unavailable.
Then, pilot qualities at the receiver from transmitters i (other than the best server) on the best carrier of the best server, icBS, are recalculated to determine the entire receiver active set (when active set is greater than 1). Same formulas and calculation method are used to update DL
I 0 ic BS and determine Q pilot i ic BS . Other cells (i,icBS) in active set must fulfill the following criteria: pilot
Q pilot i ic BS Q min
i ic BS neighbour list BS ic BS (optional) For multi-carrier 1xEV-DO Rev.B service users, these results are detailed for each sub-active set. For each carrier, Atoll displays the thermal noise, I0 (Best server), the pilot quality from the best server and from the other servers of the sub-active set, and the downlink macro-diversity gain. They are calculated as described above. •
Number of cells in active set
This is a user-defined input in the terminal properties. It corresponds to the active set size. •
Number of fingers
The number of fingers, f, of the rake receiver. This parameter is defined in the terminal properties. It is relevant in CDMA2000 1xRTT only11. This is the maximum number of active set links that the terminal (rake) can combine. •
Thermal noise
This parameter is calculated as described above (3rd step). •
I0 (Best server)
I0 (Best server) is the total noise received at the receiver on icBS. •
Downlink macro-diversity gain
This parameter is calculated as described above (5th step).
5.5.1.2 Downlink Sub-Menu Outputs calculated by Atoll depend on the studied network (CDMA2000 1xRTT or CDMA2000 1xEV-DO).
5.5.1.2.1
CDMA2000 1xRTT Let mFCH and mSCH respectively denote the number of cells in the receiver active set for the fundamental channel (FCH) and the supplemental channel (SCH) and f be the number of rake fingers defined for the terminal. We assume that f is less than or equal to mFCH and mSCH. Among the mFCH cells of the receiver active set, only the first f cells will be considered in order to determine the FCH availability on downlink. In the same way, only the first f cells among the mSCH cells of the receiver active set will be considered in order to determine the SCH availability on downlink. Each of these cells is noted (k,icBS). Atoll calculates the traffic channel quality on FCH from each cell (k,icBS). No power control is performed as in simulations. Here, Atoll determines the downlink traffic channel quality on FCH at the receiver for the maximum traffic channel power per transmitter allowed on FCH. Then, after combination, the total downlink traffic channel quality on FCH is evaluated and compared with the specified target quality.
11.
CDMA2000 1xEV-DO systems do not support soft handover on downlink.
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Atoll calculates the traffic channel quality on SCH from each cell (k,icBS). No power control is performed as in simulations. Here, Atoll determines the downlink traffic channel quality on SCH at the receiver for the maximum traffic channel power per transmitter allowed on SCH. This value depends on the downlink throughput specified in the analysis. Then, after combination, the total downlink traffic channel quality on SCH is evaluated and compared with the specified target quality. •
Eb/Nt target on FCH and Eb/Nt target on SCH DL
Eb/Nt target on FCH ( Q req FCH ) is the downlink traffic data quality target on the fundamental channel (FCH). This value is user-defined for a given service and terminal. DL
Eb/Nt target on SCH ( Q req SCH ) is the downlink traffic data quality target on the supplemental channel (SCH). This value is specified for a given service, terminal and SCH throughput. •
Required transmitter powers on FCH and SCH req
req
The calculation of the required transmitter powers on FCH and SCH ( P FCH and P SCH ) may be divided into three steps. 1st step: Eb/Nt max for the first f (number of fingers) cells of active set DL
DL
Let us assume the following notations: Eb/Nt max on FCH and SCH respectively correspond to Q max FCH and Q max SCH . Therefore, for each cell (k,icBS), we have: DL – FCH
DL Q max k
BTS P b –max k ic BS – FCH - G DL = -------------------------------------------------------p DL N tot ic BS
ic BS FCH
And DL – SCH
BTS P b –max k ic BS DL – SCH - G DL Q max k ic BS SCH = -------------------------------------------------------p DL N tot ic BS DL – FCH
With P b
DL
max
max
k
k
P FCH DL – SCH P SCH k ic BS = ---------- , P b –max k ic BS = ---------LT LT DL
DL
DL
DL
term
And N tot ic BS = I intra ic BS + I extra ic BS + I inter – carrier ic BS + I inter – techno log y ic BS + N 0 Where max
P FCH is the maximum power allowed on FCH. This parameter is user-defined in the Services table for a certain terminal. max
P SCH is the maximum power allowed on SCH for the specified downlink throughput. This parameter is user-defined in the Services table for a certain terminal and SCH throughput. L T is the total loss between the transmitter i and the receiver. k
L path L Tx L term L body L indoor M Shadowing – Eb Nt DL L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term DL
N tot ic BS is the total noise at the receiver on the best carrier of the best server. With DL
I intra ic BS = 1 – BTS F ortho P DL k ic tot BS And DL
I extra ic BS =
Ptot j icBS DL
j j k
DL
For each transmitter in the network, P tot ic BS is the total power received at the receiver from this transmitter on icBS. DL
I inter – carrier ic BS is the inter-carrier interference at the receiver on the best carrier of the best server.
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Ptot j icadj DL
DL
j ---------------------------------------I inter – carrier ic BS = txj RF ic BS ic adj
icadj is a carrier adjacent to icBS. RF ic BS ic adj is the interference reduction factor, defined between ic and icadj and set to a value different from 0. DL
I inter – techno log y ic BS is the inter-technology interference at the receiver on the best carrier of the best server. DL
I inter – techno log y ic BS =
ni
ic i is the i Tx m
ICPic ic i
BS
th
Tx
P Transmitted ic i ----------------------------------------Tx Tx m L total ICP ic ic i
BS
interfering carrier of an external transmitter
is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the
frequency gap between ic i (external network) and ic BS . 2nd step: Calculation of the total traffic channel quality on FCH and SCH DL
Q MAX FCH is the traffic channel quality on FCH at the receiver on icBS after combining the signal from each cell (k,icBS). On downlink, if there is no handoff, we have: DL
DL
Q MAX ic BS FCH = Q max k ic BS FCH For any other handoff status, we have: DL
DL
Q MAX ic BS FCH = f rake efficiency
Qmax k icBS FCH DL
k
Where DL
f rake efficiency is the downlink rake efficiency factor defined in Terminal properties. DL
Q MAX SCH is the traffic channel quality on SCH at the receiver on icBS after combining the signal from each cell (k,icBS). On downlink, if there is no handoff, we have: DL
DL
Q MAX ic BS SCH = Q max k ic BS SCH For any other handoff status, we have: DL
DL
Q MAX ic BS SCH = f rake efficiency
Qmax k icBS SCH DL
k req
req
3rd step: P FCH and P SCH calculation DL
Q req FCH req - P max P FCH = --------------------------------------FCH DL Q MAX ic BS FCH DL
Q req SCH req - P max P SCH = --------------------------------------SCH DL Q MAX ic BS SCH •
Eb/Nt max on FCH for the first f (number of fingers) cells of active set DL
Let us assume the following notation: Eb/Nt max on FCH corresponds to Q max FCH . Therefore, for each cell (k,icBS), we have: DL – FCH
BTS P b –max k ic BS DL – FCH - G DL Q max k ic BS FCH = -------------------------------------------------------p DL N tot ic BS
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max
P FCH DL – FCH DL DL DL DL term With P b –max k ic BS = ---------- and N tot ic BS = I intra ic BS + I extra ic BS + I inter – carrier ic BS + N 0 LT k
Where max
P FCH is the maximum power allowed on FCH. This parameter is user-defined in the Services table for a certain terminal. L T is the total loss between the transmitter i and the receiver. k
L path L Tx L term L body L indoor M Shadowing – Eb Nt DL L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term DL
N tot ic BS is the total noise at the receiver on the best carrier of the best server. With max
req
DL P FCH – P FCH I intra ic BS = 1 – BTS F ortho P DL tot k ic BS – 1 – BTS max (----------------------------,0) LT k
And DL
I extra ic BS =
Ptot j icBS DL
j j k
DL
For each transmitter in the network, P tot ic BS is the total power received at the receiver from the transmitter on icBS. DL
I inter – carrier ic BS is the inter-carrier interference at the receiver on the best carrier of the best server.
Ptot j icadj DL
DL
txj j I inter – carrier ic BS = ---------------------------------------RF ic BS ic adj
icadj is a carrier adjacent to icBS. RF ic BS ic adj is the interference reduction factor, defined between ic and icadj and set to a value different from 0. DL
I inter – techno log y ic BS is the inter-technology interference at the receiver on the best carrier of the best server. DL
I inter – techno log y ic BS =
ni
ic i is the i Tx m
ICP ic ic i
BS
th
Tx
P Transmitted ic i ----------------------------------------Tx Tx m L total ICP ic ic i
BS
interfering carrier of an external transmitter
is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the
frequency gap between ic i (external network) and ic BS . •
Eb/Nt max on SCH for the first f (number of fingers) cells of active set DL
Let us assume the following notation: Eb/Nt max on SCH corresponds to Q max SCH . Therefore, for each cell (k,icBS), we have: DL – SCH
BTS P b –max k ic BS DL – SCH - G DL Q max k ic BS SCH = -------------------------------------------------------p DL N tot ic BS max
P SCH DL – SCH With P b –max k ic BS = ---------LT k
DL
DL
DL
DL
DL
term
and N tot ic BS = I intra ic BS + I extra ic BS + I inter – carrier ic BS + I inter – techno log y ic BS + N 0 Where
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P SCH is the maximum power allowed on SCH for the specified downlink throughput. This parameter is user-defined in the Services table for a certain terminal and SCH throughput. L T is the total loss between the transmitter i and the receiver. k
L path L Tx L term L body L indoor M Shadowing – Eb Nt DL L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term DL
N tot ic BS is the total noise at the receiver on the best carrier of the best server. With max
req
DL P SCH – P SCH I intra ic BS = 1 – BTS F ortho P DL tot k ic BS – 1 – BTS max (----------------------------,0) LT k
And DL
I extra ic BS =
Ptot j icBS DL
j j k
DL
For each transmitter in the network, P tot ic BS is the total power received at the receiver from the transmitter on icBS. DL
I inter – carrier ic BS is the inter-carrier interference at the receiver on the best carrier of the best server.
Ptot j icadj DL
DL
j ---------------------------------------I inter – carrier ic BS = txj RF ic BS ic adj
icadj is a carrier adjacent to icBS. RF ic BS ic adj is the interference reduction factor, defined between ic and icadj and set to a value different from 0. DL
I inter – techno log y ic BS is the inter-technology interference at the receiver on the best carrier of the best server. DL
I inter – techno log y ic BS =
ni
ic i is the i Tx m
ICPic ic i
BS
th
Tx
P Transmitted ic i ----------------------------------------Tx Tx m L total ICP ic ic i
BS
interfering carrier of an external transmitter
is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming the
frequency gap between ic i (external network) and ic BS . •
Eb/Nt max on FCH and Eb/Nt max on SCH
DL
Q MAX FCH is the traffic channel quality on FCH at the receiver on icBS after combining the signal from each cell (k,icBS). On downlink, if there is no handoff, we have: DL
DL
Q MAX ic BS FCH = Q max k ic BS FCH For any other handoff status, we have: DL
DL
Q MAX ic BS FCH = f rake efficiency
Qmax k icBS FCH DL
k
Where DL
f rake efficiency is the downlink rake efficiency factor defined in Terminal properties. DL
Q MAX SCH is the traffic channel quality on SCH at the receiver on icBS after combining the signal from each cell (k,icBS). On downlink, if there is no handoff, we have:
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DL
Q MAX ic BS SCH = Q max k ic BS SCH For any other handoff status, we have: DL
DL
Q MAX ic BS SCH = f rake efficiency
Qmax k icBS SCH DL
k
Therefore, the service on the downlink traffic channel is available if DL Q MAX ic BS SCH
•
DL Q req SCH
DL
DL
Q MAX ic BS FCH Q req FCH
and
.
Effective Eb/Nt on FCH and Eb/Nt on SCH
DL
DL
Q eff FCH and Q eff SCH are respectively effective traffic channel qualities at the receiver on icBS supplied on FCH and SCH. DL
DL
DL
DL
DL
Q eff FCH = min Q MAX FCH Q req FCH And DL
Q eff SCH = min Q MAX SCH Q req SCH •
Downlink soft handover gain on FCH and downlink soft handover gain on SCH
DL
DL
G SHO FCH and G SHO SCH respectively correspond to DL soft handover gains on FCH and SCH. DL
Q MAX ic BS FCH DL G SHO FCH = -------------------------------------------------------------DL max Q max k ic BS FCH k
And DL
Q MAX ic BS SCH DL G SHO SCH = -------------------------------------------------------------DL max Q max k ic BS SCH k
max k
5.5.1.2.2
DL Q max k
DL
ic BS corresponds to the highest Q max k ic BS value.
CDMA2000 1xEV-DO Atoll calculates the effective pilot quality level at the receiver and compares this value with the required quality level. 1xEV-DO Rev.0 and 1xEV-DO Rev. A Service Users For 1xEV-DO Rev.0 and 1xEV-DO Rev. A users, Atoll displays the following results: •
Required throughput DL
The required throughput, TP req , is the downlink throughput selected for the analysis. •
Required C/I
C For 1xEV-DO Rev. 0 users, the required C/I ( --- ) is determined from the graph “Peak throughput=f(C/I)” defined for the I req mobility type selected in the analysis. It corresponds to the value read in the graph “Peak throughput=f(C/I) (Rev0)” for the DL
specified required throughput, TP req . DL
For 1xEV-DO Rev. A users, the required throughput ( TP req ) is obtained by using a certain downlink transmission format (i.e. a 1xEV-DO radio bearer ( Index DL – Bearer ) with a certain number of timeslots ( n TS )). It is calculated as follows: DL
TP P – R LC Index DL – Bearer DL TP req = -----------------------------------------------------------n TS
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C --- is the value defined in the 1xEV-DO Radio Bearer Selection (Downlink) table for this downlink transmission format I req (radio bearer Index, mobility and number of timeslots). It corresponds to the C/I required to obtain the defined required DL
throughput, TP req . •
Effective C/I
Ec Let ----- ic BS b pilot be the effective C/I at the receiver on icBS. Nt For the best cell (BS,icBS) of the receiver active set, we have: E 1 - ----c- ic BS b pilo t = -----------------------------Nt 1 ---------------------- – 1 Q pilot resulting Where pilot
DL
Q resulting ic BS = G macro – diversity Q pilot ic BS BS
•
Obtained throughput
For 1xEV-DO Rev. 0 users, the obtained throughput, TP defined for the mobility type selected in the analysis. TP
DL
DL
, is determined from the graph “Peak throughput=f(C/I) (Rev0)” is the value read in the graph “Peak throughput=f(C/I) (Rev0)” for
E the calculated effective C/I, ----c- ic BS b pilot . Nt For 1xEV-DO Rev. A users, the obtained throughput ( TP
DL
) on downlink depends on the downlink transmission format, i.e the
radio bearer index ( Index DL – Bearer ) with the number of timeslots ( n TS ). For the defined mobility type, Atoll selects the E C downlink transmission format where ----c- ic BS b pilot --- . Then, it determines the downlink obtained throughput as I req Nt follows: TP
DL
DL
TP P –R LC Index DL – Bearer = -----------------------------------------------------------n TS
The traffic data channel in downlink is available if TP •
DL
DL
TP req .
Bearer Consumption
For (1xEV-DO Rev. A - Guaranteed bit rate) service users, Atoll calculates the 1xEV-DO bearer consumption. TPD min – DL C DL – Bearer = -----------------------------------------------------------DL TPP –R LC Index DL – Bearer Where TPD min – DL corresponds to the minimum bit rate required by the service in the downlink. 1xEV-DO Rev. B Service Users For single-carrier and multi-carrier 1xEV-DO Rev. B users, Atoll displays the following results: •
Required throughput DL
The required throughput, TP req , is the downlink throughput selected for the analysis. •
Obtained throughput
The obtained throughput corresponds to the sum of the obtained throughputs on each carrier. TP
DL
=
TP
DL
ic
ic
The traffic data channel on downlink is available if TP •
DL
DL
TP req .
For each sub-active set, Atoll indicates the effective C/I and the obtained throughput:
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E Let ----c- ic b pilot be the effective C/I at the receiver on ic, the carrier associated with the sub-active set. Nt For the best cell (BS,ic) of the receiver sub-active set, we have: pilot E Q resulting ic ----c- ic b pilot = ----------------------------------------pilot Nt – Q resulting ic
Where pilot
DL
Q resulting ic = G macro – diversity Q pilot ic BS
DL
The obtained throughput ( TP ic ) on downlink depends on the downlink transmission format, i.e the radio bearer index ( Index DL – Bearer ) with the number of timeslots ( n TS ). For the defined mobility type, Atoll selects the downlink transmission Ec C format where ----- ic b pilot --- and whose modulation scheme is supported by the terminal. Nt I req C --- I req is the value defined in the 1xEV-DO Radio Bearer Selection (Downlink) table for this downlink transmission format (radio bearer Index, mobility and number of timeslots). It corresponds to the C/I required to obtain the defined required DL
throughput, R req . The downlink obtained throughput is determined as follows: DL
TP P – RLC Index DL – Bearer DL TP ic = -------------------------------------------------------------n TS
5.5.1.3 Uplink Sub-Menu Outputs calculated by Atoll depend on the studied network (CDMA2000 1xRTT or CDMA2000 1xEV-DO).
5.5.1.3.1
CDMA2000 1xRTT For each cell (i,icBS) in the receiver active set, Atoll calculates the uplink traffic channel quality on FCH and SCH from the receiver. No power control is performed as in simulations. Here, Atoll determines the uplink traffic channel quality on FCH at the cell for the maximum terminal power allowed on FCH. In the same way, it evaluates the uplink traffic channel quality on SCH at the cell for the maximum terminal power allowed on SCH. Then, total uplink traffic channel qualities on FCH and SCH are evaluated with respect to the receiver handover status. From these values, Atoll deduces required terminal powers on FCH and SCH, calculates the total terminal power required and compares this value with the maximum terminal power allowed. •
Max terminal power on FCH and SCH max
The Max terminal power parameter ( P term ) is user-defined for each terminal. It corresponds to the maximum terminal power allowed. On uplink, the terminal power is shared between pilot, FCH and SCH channels. So, we may write: max
max
max
max
P term = P term pilot + P term FCH + P term SCH We have: max
max
P term pilot = p P term Where p is the percentage of the terminal power dedicated to pilot. This parameter is user-defined in the terminal properties. And UL
FCH
UL
max Q req FCH TP P – UL AF FCH P term FCH - -------------------------------------------------------------- = ---------------------UL SCH max Q req SCH TP P – UL P term SCH
Therefore, max
1 – p P term max P term FCH = ----------------------------------------------------------------------------UL SCH Q req SCH TP P – UL 1 + -------------------------------------------------------------------UL FCH UL Q req FCH TP P – UL AF FCH And
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1 – p P term max P term SCH = ----------------------------------------------------------------------------UL FCH UL Q req FCH TP P – UL AF FCH 1 + -------------------------------------------------------------------UL SCH Q req SCH TP P – UL •
Required terminal power on FCH and SCH req
req
The required terminal powers on FCH and SCH, respectively P term FCH and P term SCH , are calculated as follows: UL
1st step: Evaluation of uplink traffic channel qualities on FCH and SCH, Q max ic BS i
UL
FCH
and Q max ic BS i
SCH
, for each cell
of active set. For each cell (i,icBS), we have: UL – FCH
term P b –max i ic BS UL – FCH - G UL Q max i ic BS FCH = --------------------------------------------------------p UL N tot i ic BS And UL – SCH
UL Q max i
ic BS SCH
term P b –max i ic BS – SCH - G UL = --------------------------------------------------------p UL N tot i ic BS max
max
P term FCH P term SCH UL – FCH UL – SCH With P b –max i ic BS = ------------------------ and P b –max i ic BS = -----------------------LT LT i
i
L T is the total loss between the transmitter i and the receiver. i
L path L Tx L term L body L indoor M Shadowing – Eb Nt UL L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term UL
N tot i ic BS is the total noise at the transmitter on the best carrier of the best server. This value is deduced from the cell UL
uplink load factor X i ic BS . tx
N0 UL N tot i ic BS = ----------------------------------UL 1 – X i ic BS tx
N 0 is the transmitter thermal noise. UL
UL
2nd step: Calculation of FCH and SCH total traffic channel qualities at the transmitter on icBS, Q MAX FCH and Q max SCH , based on the receiver handover status. If there is no handoff, we have: UL
UL
UL
UL
Q MAX ic BS FCH = Q max i ic BS FCH and Q MAX ic BS SCH = Q max i ic BS SCH For soft handover, we have: UL
UL
UL
Q MAX ic BS FCH = G macro – diversity 2 links max Q max i ic BS FCH i
And UL
UL
UL
Q MAX ic BS SCH = G macro – diversity 2 links max Q max i ic BS SCH i
UL
G macro – diversity 2 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. UL
UL
max Q max i ic BS corresponds to the highest Q max i ic BS value. i
For soft-soft handover, we have: UL
UL
UL
Q MAX ic BS FCH = G macro – diversity 3 links max Q max i ic BS FCH i
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And UL
UL
UL
Q MAX ic BS SCH = G macro – diversity 3 links max Q max i ic BS SCH i
UL
G macro – diversity 3 links is the uplink macro-diversity gain.This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. For softer and softer-softer handovers, we have: UL
UL
Q MAX ic BS FCH = f rake efficiency
Qmax i icBS FCH UL
i UL
UL
And Q MAX ic BS SCH = f rake efficiency
Qmax i icBS SCH UL
i
For softer-soft handover, there are two possibilities. If the MRC option is selected (option available in Global parameters), we have: UL UL UL Q MAX ic BS FCH = G macro – diversity 2 links max f rake efficiency
UL
UL
Q max i ic BS FCH Q max
i ic BS
i on the other site
i on the same site
FCH
And UL UL UL Q MAX ic BS SCH = G macro – diversity 2 links max f rake efficiency
UL
UL
Q max i ic BS SCH Q max
i ic BS
i on the other site
i on the same site
SCH
otherwise, UL
UL
UL
Q MAX ic BS FCH = G macro – diversity 2 links max Q max i ic BS FCH i
And UL
UL
UL
Q MAX ic BS SCH = G macro – diversity 2 links max Q max i ic BS SCH i
req
req
3rd step: Calculation of P term FCH and P term SCH UL
UL
Q req FCH Q req SCH req req - P max - P max P term FCH = --------------------------------------term FCH and P term SCH = --------------------------------------term SCH UL UL Q MAX ic BS FCH Q MAX ic BS SCH Where UL
Q req FCH is the user-defined uplink data traffic quality target on FCH for a given service and a terminal. This parameter is available in the Services table. UL
Q req SCH is the user-defined uplink data traffic quality target on SCH for a given service, terminal and SCH throughput. This parameter is available in the Services table. req
Then, from the required terminal power on FCH and SCH, Atoll determines the total terminal power required ( P term ). req
req
req
req
P term = P term FCH + P term SCH + P term pilot req
req
As P term pilot = p P term , we have: req
req
P term FCH + P term SCH req P term = -------------------------------------------------------1–p req
max
Therefore, the service on the uplink data traffic channel is available if P term P term . •
Eb/Nt max on FCH for each cell in active set
For each cell (i,icBS), we have: UL – FCH
term P b –max i ic BS UL – FCH - G UL Q max i ic BS FCH = --------------------------------------------------------p UL N tot i ic BS
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P term FCH UL – FCH With P b –max i ic BS = -----------------------LT i
L T is the total loss between the transmitter i and the receiver. i
L path L Tx L term L body L indoor M Shadowing – Eb Nt UL L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term UL
N tot i ic BS is the total noise at the transmitter on the best carrier of the best server. This value is deduced from the cell UL
uplink load factor X i ic BS . tx
max
req
N0 P FCH – P FCH UL - + 1 – term max (--------------------------N tot i ic BS = -----------------------------------,0) UL LT 1 – X i ic BS i tx
N 0 is the transmitter thermal noise. •
Eb/Nt max on SCH for each cell in active set
For each cell (i,icBS), we have: UL – SCH
term P b –max i ic BS UL – SCH - G UL Q max i ic BS SCH = --------------------------------------------------------p UL N tot i ic BS max
P term SCH UL – SCH With P b –max i ic BS = -----------------------LT i
L T is the total loss between the transmitter i and the receiver. i
L path L Tx L term L body L indoor M Shadowing – Eb Nt UL L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term UL
N tot i ic BS is the total noise at the transmitter on the best carrier of the best server. This value is deduced from the cell UL
uplink load factor X i ic BS . tx
max
req
N0 P SCH – P SCH UL N tot i ic BS = -----------------------------------,0) - + 1 – term max (--------------------------UL LT 1 – X i ic BS i tx
N 0 is the transmitter thermal noise. •
Eb/Nt max on FCH and SCH
UL
UL
Q MAX ic BS FCH and Q MAX ic BS SCH are respectively the traffic channel qualities on FCH and SCH at the transmitter on icBS after signal combination of all the transmitters of the active set. If there is no handoff, we have: UL
UL
UL
UL
Q MAX ic BS FCH = Q max i ic BS FCH and Q MAX ic BS SCH = Q max i ic BS SCH For soft handover, we have: UL
UL
UL
Q MAX ic BS FCH = G macro – diversity 2 links max Q max i ic BS FCH i
And UL
UL
UL
Q MAX ic BS SCH = G macro – diversity 2 links max Q max i ic BS SCH i
UL
G macro – diversity 2 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. UL
UL
max Q max i ic BS corresponds to the highest Q max i ic BS value. i
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For soft-soft handover, we have: UL
UL
UL
Q MAX ic BS FCH = G macro – diversity 3 links max Q max i ic BS FCH i
And UL
UL
UL
Q MAX ic BS SCH = G macro – diversity 3 links max Q max i ic BS SCH i
UL
G macro – diversity 3 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. For softer and softer-softer handovers, we have: UL
UL
Q MAX ic BS FCH = f rake efficiency
Qmax i icBS FCH UL
i UL
UL
And Q MAX ic BS SCH = f rake efficiency
Qmax i icBS SCH UL
i
For softer-soft handover, there are two possibilities. If the MRC option is selected (option available in Global parameters), we have: UL UL UL Q MAX ic BS FCH = G macro – diversity 2 links max f rake efficiency
UL
UL
Q max i ic BS FCH Q max
i ic BS
i on the other site
i on the same site
FCH
And UL UL UL Q MAX ic BS SCH = G macro – diversity 2 links max f rake efficiency
UL
UL
Q max i ic BS SCH Q max
i ic BS
i on the other site
i on the same site
SCH
otherwise, UL
UL
UL
Q MAX ic BS FCH = G macro – diversity 2 links max Q max i ic BS FCH i
And UL
UL
UL
Q MAX ic BS SCH = G macro – diversity 2 links max Q max i ic BS SCH i
•
Effective Eb/Nt on FCH and SCH
UL
Q eff FCH is the uplink effective traffic channel quality on FCH at the receiver on icBS. UL
Q eff SCH is the uplink effective traffic channel quality on SCH at the receiver on icBS. UL
UL
UL
UL
UL
UL
Q eff FCH = min Q MAX FCH Q req FCH and Q eff SCH = min Q MAX SCH Q req SCH •
Uplink soft handover gain FCH and SCH
UL
G SHO FCH corresponds to the UL soft handover gain on FCH. UL
G SHO SCH corresponds to the UL soft handover gain on SCH. UL
UL
Q MAX ic BS FCH Q MAX ic BS SCH UL UL G SHO FCH = ------------------------------------------------------------ and G SHO SCH = -----------------------------------------------------------UL UL max Q max i ic BS FCH max Q max i ic BS SCH I
UL
I
UL
max Q max i ic BS corresponds to the highest Q max i ic BS value. I
5.5.1.3.2
CDMA2000 1xEV-DO 1xEV-DO Rev.0 and 1xEV-DO Rev. A Service Users For each cell (l,icBS) in the receiver active set, Atoll calculates the uplink quality level from the receiver. No power control is performed as in simulations. Here, Atoll determines the uplink quality level at the cell for the maximum terminal power
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allowed. Then, the total uplink quality level is evaluated with respect to the receiver handover status. From this value, Atoll calculates the required terminal power and compares it with the maximum terminal power allowed. •
Max terminal power max
The Max terminal power parameter ( P term ) is user-defined for each terminal. It corresponds to the maximum terminal power allowed. •
Required terminal power with ACK req
The required terminal power ( P term ) calculation may be divided into four steps: UL
1st step: Evaluation of the uplink quality, Q max i ic BS , for each cell of active set For each cell (i,icBS), we have: UL
term P b – max i ic BS UL - G UL Q max i ic BS = ----------------------------------------------------p UL N tot i ic BS max
P term UL With P b –max i ic BS = -----------LT i
L T is the total loss between the transmitter i and the receiver. i
L path L Tx L term L body L indoor M Shadowing – Eb Nt UL L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term UL
N tot i ic BS is the total noise at the transmitter on the best carrier of the best server. This value is deduced from the cell UL
uplink load factor X i ic BS . tx
max
req
N0 P term – P term UL - + 1 – term max (-----------------------------N tot i ic BS = -----------------------------------,0) UL LT 1 – X i ic BS i tx
N 0 is the transmitter thermal noise. UL
2nd step: Calculation of the total quality at the transmitter on icBS ( Q MAX ) based on the receiver handover status. If there is no handoff, we have: UL
UL
Q MAX ic BS = Q max i ic BS For soft handover, we have: UL
UL
UL
Q MAX ic BS = G macro – diversity 2 links max Q max i ic BS i
UL
G macro – diversity 2 links is the uplink macro-diversity gain.This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. UL
UL
max Q max i ic BS corresponds to the highest Q max i ic BS value. i
For soft-soft handover, we have: UL
UL
UL
Q MAX ic BS = G macro – diversity 3 links max Q max i ic BS i
UL
G macro – diversity 3 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. For softer and softer-softer handovers, we have: UL
UL
Q MAX ic BS = f rake efficiency
Qmax i icBS UL
i
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For softer-soft handover, there are two possibilities. If the MRC option is selected (option available in Global parameters), we have: UL UL UL Q MAX ic BS = G macro – diversity 2 links max f rake efficiency
Qmax i icBS Qmaxi on the other site i icBS UL
UL
i on the same site
otherwise, UL
UL
UL
Q MAX ic BS = G macro – diversity 2 links max Q max i ic BS i
UL
3rd step: Evaluation of the required quality level on uplink, Q req In case of a 1xEV-DO Rev. 0 capable terminal, we have: E UL UL UL Q req = ----c- G p 1 + G ACK + G DRC + G TCH N t min Where Ec ---is the minimum pilot quality level on uplink. This parameter is available in the Mobility types table. N t min UL
G ACK , G DRC and G TCH are respectively acknowledgement, data rate control and traffic data gains relative to the pilot. They are defined in the terminal properties (1xEV-DO Rev. 0 tab). In case of a 1xEV-DO Rev. A capable terminal, we have: E UL UL UL Q req = ----c- G p 1 + G ACK + G DRC + G TCH + G RRI + G Auxiliary – pilot N t min Where Ec UL ---is the minimum pilot quality level required on uplink to obtain the defined throughput, TP req . The required N t min UL
UL
throughput, TPreq (i.e. the uplink throughput selected for the analysis) is obtained by using a certain uplink transmission format (i.e. 1xEV-DO radio bearer ( Index UL – Bearer ) with a certain number of subframes ( n SF )) and calculated as follows: UL
TP P – R LC Index UL – Bearer UL TP req = -----------------------------------------------------------n SF Ec --- N t min is the value defined in the 1xEV-DO Radio Bearer Selection (Uplink) table for this uplink transmission format (radio UL
bearer Index, mobility and number of subframe). Two values are available for this parameter, one when the service uplink mode is "Low Latency" and another one for high capacity services. G ACK , G DRC , G TCH , G RRI and G Auxiliary – pilot are respectively acknowledgement, data rate control, traffic data channel, reverse rate indicator and auxiliary pilot channel gains relative to the pilot. They are defined in the terminal properties (1xEVDO Rev. A tab). Two values of G TCH are available, one when the service uplink mode is "Low Latency" and another one for high capacity services. req
4th step: Calculation of P term UL
Q req req - P max P term = -------------------------term UL Q MAX ic BS req
max
Therefore, the service on the uplink traffic data channel is available if P term P term . •
Required terminal power without ACK
Atoll also calculates the required terminal power without taking into account the ACK channel contribution. Calculations are quite similar to those detailed in the previous paragraph, only the evaluation of the required quality on uplink is different. In this case, we have: E UL UL UL Q req withoutACK = ----c- G p 1 + G DRC + G TCH for 1xEV-DO Rev. 0 capable terminals N t min
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And E UL UL Q req withoutACK = ----c- G p 1 + G DRC + G TCH + G RRI + G Auxiliary – pilot for 1xEV-DO Rev. A capable terminals N t min UL
And then, UL
Q req withoutACK req - P max P term withoutACK = -------------------------------------term UL Q MAX ic BS •
UL SHO gain UL
1st step: Evaluation of the uplink quality, Q max i ic BS , for each cell of active set. For each cell (i,icBS), we have: UL
term P b – max i ic BS UL - G UL Q max i ic BS = ----------------------------------------------------p UL N tot i ic BS max
P term UL With P b –max i ic BS = -----------LT i
L T is the total loss between the transmitter i and the receiver. i
L path L Tx L term L body L indoor M Shadowing – Eb Nt UL L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term UL
N tot i ic BS is the total noise at the transmitter on the best carrier of the best server. This value is deduced from the cell UL
uplink load factor X i ic BS . tx
max
req
N0 P term – P term UL N tot i ic BS = -----------------------------------,0) - + 1 – term max (-----------------------------UL LT 1 – X i ic BS i tx
N 0 is the transmitter thermal noise. UL
2nd step: Calculation of the total quality at the transmitter on icBS ( Q MAX ) based on the receiver handover status. UL
Q MAX ic BS is the traffic channel quality at the transmitter on icBS after signal combination of all the transmitters of the active set. If there is no handoff, we have: UL
UL
Q MAX ic BS = Q max i ic BS For soft handover, we have: UL
UL
UL
Q MAX ic BS = G macro – diversity 2 links max Q max i ic BS i
UL
G macro – diversity 2 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. UL
UL
max Q max i ic BS corresponds to the highest Q max i ic BS value. i
For soft-soft handover, we have: UL
UL
UL
Q MAX ic BS = G macro – diversity 3 links max Q max i ic BS i
UL
G macro – diversity 3 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. For softer and softer-softer handovers, we have:
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Qmax i icBS UL
i
For softer-soft handover, there are two possibilities. If the MRC option is selected (option available in Global parameters), we have: UL UL UL Q MAX ic BS = G macro – diversity 2 links max f rake efficiency
Qmax i icBS Qmaxi on the other site i icBS UL
UL
i on the same site
otherwise, UL
UL
UL
Q MAX ic BS = G macro – diversity 2 links max Q max i ic BS i
3rd step: Calculation of the UL SHO gain UL
G SHO corresponds to the uplink soft handover gain. UL
Q MAX ic BS UL G SHO = ----------------------------------------------UL max Q max i ic BS i
•
Bearer Consumption
For (1xEV-DO Rev. A - Guaranteed bit rate) service users, Atoll calculates the 1xEV-DO bearer consumption. TPD min – UL C UL – Bearer = -------------------------------------------------------------UL TP P – RLC Index UL – Bearer Where TPD min – UL corresponds to the minimum bit rate required by the service in the uplink. 1xEV-DO Rev. B Service Users For multi-carrier 1xEV-DO Rev. B users, Atoll models load balancing between carriers. Atoll shares the available terminal power between the carriers and determines the uplink 1xEV-DO radio bearer obtained on each carrier. It starts allocating the maximum terminal power to the best carrier and selects the highest 1xEV-DO radio bearer. If it remains terminal power after serving the first carrier, then Atoll continues allocating the available terminal power to the second carrier, and so on for the other carriers of the active set as long as the remaining terminal power is sufficient to obtain the lowest bearer. The following results are displayed: •
For each carrier used in the selected configuration, Atoll indicates the UL SHO Gain, the obtained throughput and the required power.
The calculations can be divided into four steps: UL
1st step: Evaluation of the uplink quality, Q max i ic , for each cell of the sub-active set For each cell (i,ic), we have: UL
term P b –max i ic UL - G UL Q max i ic = -----------------------------------------------p UL N tot i ic max
P term ic UL With P b –max i ic = --------------------LT i
max
P term ic is the terminal power available for the carrier (ic). L T is the total loss between the transmitter i and the receiver. i
L path L Tx L term L body L indoor M Shadowing – Eb Nt UL L T = ---------------------------------------------------------------------------------------------------------------------------------------------G Tx G term UL
UL
N tot i ic is the total noise at the transmitter on the carrier ic. This value is deduced from the cell uplink load factor X i ic . tx
max
req
N0 P term ic – P term UL - + 1 – term max (---------------------------------------N tot i ic = -----------------------------,0) UL LT 1 – X i ic i
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N 0 is the transmitter thermal noise. UL
2nd step: Calculation of the total quality at the transmitter on ic ( Q MAX ) based on the receiver handover status. If there is no handoff, we have: UL
UL
Q MAX ic = Q max i ic For soft handover, we have: UL
UL
UL
Q MAX ic = G macro – diversity 2 links max Q max i ic i
UL
G macro – diversity 2 links is the uplink macro-diversity gain.This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. UL
UL
max Q max i ic corresponds to the highest Q max i ic value. i
For soft-soft handover, we have: UL
UL
UL
Q MAX ic = G macro – diversity 3 links max Q max i ic i
UL
G macro – diversity 3 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected (Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters. For softer and softer-softer handovers, we have: UL
UL
Q MAX ic = f rake efficiency
Qmax i ic UL
i
For softer-soft handover, there are two possibilities. If the MRC option is selected (option available in Global parameters), we have: UL UL UL Q MAX ic = G macro – diversity 2 links max f rake efficiency
Qmax i ic Qmaxi on the other site i ic UL
UL
i on the same site
otherwise, UL
UL
UL
Q MAX ic = G macro – diversity 2 links max Q max i ic i
UL
3rd step: Calculation of the UL SHO gain ( G SHO ) UL
Q MAX ic UL G SHO = ------------------------------------------UL max Q max i ic i
4th step: Selection of the uplink 1xEV-DO radio bearer UL
req
Atoll evaluates of the required quality level in the uplink ( Q req ) and the required terminal power ( P term ic ) for each 1xEVDO radio bearer. E UL UL Q req = ----c- G p 1 + G ACK + G DRC + G TCH + G RRI + G Auxiliary – pilot N t min UL
Where Ec ---is the minimum pilot quality level required in the uplink to obtain the 1xEV-DO radio bearer. The values are defined N t min UL
in the 1xEV-DO Radio Bearer Selection (Uplink) table for each uplink transmission format (radio bearer Index, mobility and number of subframe). Two values are available, one when the service uplink mode is "Low Latency" and another one for high capacity services. G ACK , G DRC , G TCH , G RRI and G Auxiliary – pilot are respectively acknowledgement, data rate control, traffic data channel, reverse rate indicator and auxiliary pilot channel gains relative to the pilot. They are defined in the terminal properties (1xEV-
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DO Rev. A tab). Two values of G TCH are available, one when the service uplink mode is "Low Latency" and another one for high capacity services. And UL
Q req req - P max P term ic = --------------------term ic UL Q MAX ic Then, Atoll selects the best 1xEV-DO radio bearer. This is the 1xEV-DO radio bearer ( Index UL – Bearer ) with the highest UL
TPP – RLC Index UL – Bearer UL obtained throughput ( TP ic = -------------------------------------------------------------) where: n SF Index UL – Bearer req
max
•
P term ic P term ic ,
•
And the required modulation scheme is supported by the terminal.
n SF is the number of subframes associated with the 1xEV-DO radio bearer ( Index UL – Bearer ). •
Max terminal power max
The Max terminal power parameter ( P term ) is user-defined for each terminal. It corresponds to the maximum terminal power allowed. •
Required throughput UL
The required throughput, R req , is the uplink throughput selected for the analysis. •
Obtained throughput
Atoll calculates the throughput for all combinations of carriers. m UL TP total
=
TP
UL
ic where m corresponds to the number of carriers in the combination.
ic = 1
The obtained throughput ( TP
UL
) corresponds to the best configuration among all combinations of carriers, i.e., the UL
combination which provides the highest throughput, Max TP total . The traffic data channel is available in uplink if TP •
UL
UL
TP req .
Required terminal power m
req P term
=
Pterm ic req
ic = 1
5.5.2 Coverage Studies Atoll calculates CDMA-specific coverage studies on each pixel where the pilot signal level exceeds the minimum RSCP threshold. Let us assume each pixel of the map corresponds to a probe receiver with a terminal, a mobility type and a service. This receiver does not create any interference. You can make the coverage prediction for a specific carrier or for the best 1xRTT or 1xEV-DO carrier. The type of carrier and the carriers you can select depend on the service and on the frequency band(s) supported by the terminal. Coverage studies are based on the uplink load percentage and the downlink total power of cells. These parameters can either be either simulation results, or average values calculated from a group of simulations, or user-defined cell inputs.
5.5.2.1 Pilot Quality Analysis For further details on calculation formulas, see "Definitions and Formulas" on page 340. For further details on calculations, see "Bar Graph and Pilot Sub-Menu" on page 392 1st case: Analysis based on a specific carrier The carrier that can be used by transmitters is fixed. In this case, for each transmitter i containing the receiver in its calculation area and using the selected carrier, Atoll calculates pilot quality at the receiver on this carrier icgiven. Then, it determines the best serving transmitter BS using the carrier icgiven ( Q pilot ic given ) and deduces the best pilot quality received with a fixed BS
cell edge coverage probability,
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Atoll displays the best pilot quality received with a fixed cell edge coverage probability. 2nd case: Analysis based on the best carrier of all frequency bands Atoll proceeds as in point analysis. It determines the best carrier of each transmitter i containing the receiver in its calculation area and using a frequency band supported by the receiver’s terminal. The best carrier selection depends on the option selected for the site equipment (UL minimum noise, DL minimum power, random, sequential) and is based on the UL load percentage and the downlink total power of cells (simulation results or cell properties). Atoll calculates the pilot quality at the receiver from these transmitters on their best carrier and determines the best serving transmitter BS on its best carrier icBS Resulting
( Q pilot ic BS ). Then, it deduces the best pilot quality received with a fixed cell edge coverage probability, Q pilot BS
ic BS .
Atoll displays the best pilot quality received with a fixed cell edge coverage probability. 3rd case: Analysis based on the best carrier of any frequency band (for multi-band terminals with priority defined on frequency bands only) The frequency band that can be used is fixed. Atoll determines the best carrier of each transmitter i containing the receiver in its calculation area and using the selected frequency band. The best carrier selection depends on the option selected for the site equipment (UL minimum noise, DL minimum power, random, sequential) and is based on the UL load percentage and the downlink total power of cells (simulation results or cell properties). Then, Atoll calculates the pilot quality at the receiver from these transmitters on their best carrier and determines the best serving transmitter BS on its best carrier icBS Resulting
( Q pilot ic BS ). Then, it calculates the best pilot quality received with a fixed cell edge coverage probability, Q pilot BS
ic BS .
Atoll displays the best pilot quality received with a fixed cell edge coverage probability. •
Single colour Resulting
Atoll displays a coverage if Q pilot
req
ic Q pilot . Coverage consists of a single layer with a unique colour.
ic = ic BS or ic given •
Colour per transmitter Resulting
Atoll displays a coverage if Q pilot
req
ic Q pilot ( ic = ic BS or ic given ). Coverage consists of several layers with associated
colours. There is a layer per transmitter with no intersection between layers. Layer colour is the colour assigned to the best serving transmitter BS. •
Colour per mobility
In this case, the receiver is not completely defined and no mobility assigned. Coverage consists of several layers with a layer per user-defined mobility type defined in the Mobility Types sub-folder. For each layer, area is covered if Resulting
Q pilot •
req
ic Q pilot ( ic = ic BS or ic given ). Each layer is assigned a colour and displayed with intersections between layers.
Colour per probability
This display option is available only if analysis is based on all simulations in a group (i.e. if you select a group of simulations and the “All” option in the Condition tab of prediction properties). Coverage consists of several layers with a layer per user-defined probability level defined in the Display tab (Prediction Resulting
properties). For each layer, area is covered if Q pilot
req
ic Q pilot ( ic = ic BS or ic given ) in the required number of
simulations. Each layer is assigned a colour and displayed with intersections between layers. •
Colour per cell edge coverage probability
Coverage consists of several layers with a layer per user-defined cell edge coverage probability, p, defined in the Display tab Resulting
(Prediction properties). For each layer, area is covered if Q pilot
req
ic p Q pilot ( ic = ic BS or ic given ). Each layer is assigned
a colour and displayed with intersections between layers. •
Colour per quality level (Ec/I0)
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction Resulting
properties). For each layer, area is covered if Q pilot
ic Q pilot threshold ( ic = ic BS or ic given ). Each layer is assigned a
colour and displayed with intersections between layers. •
Colour per quality margin (Ec/I0 margin)
Coverage consists of several layers with a layer per user-defined quality margin defined in the Display tab (Prediction Resulting
properties). For each layer, area is covered if Q pilot
req
ic – Q pilot Q pilot m arg in ( ic = ic BS or ic given ). Each layer is
assigned a colour and displayed with intersections between layers.
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Colour per pilot signal level (Ec) Coverage consists of several layers with a layer per user-defined pilot signal level defined in the Display tab (Prediction Resulting
properties). For each layer, area is covered if Q pilot
ic Q pilot threshold ( ic = ic BS or ic given ). Each layer is assigned a
colour and displayed with intersections between layers.
5.5.2.2 Downlink Service Area Analysis The downlink service area analysis depends on the studied network (CDMA2000 1xRTT or CDMA2000 1xEV-DO). Several display options are available when calculating this study, some of which are dedicated to CDMA2000 1xRTT networks while others are relevant when analysing CDMA2000 1xEV-DO systems only.
5.5.2.2.1
CDMA2000 1xRTT As in point analysis, Atoll calculates downlink quality on FCH at the receiver for each cell (k,ic) (with ic=icBS or icgiven) (these cells are the first f cells in the receiver’s active set and f is the number of fingers defined for the terminal). No power control is performed as in simulations. Here, Atoll determines the downlink quality on FCH at the receiver for a maximum traffic channel power per transmitter allowed on the fundamental channel (FCH). Then, the total downlink quality on FCH DL
( Q MAX ic FCH ) is evaluated after recombination. Best server and active set determination is performed as in point prediction.
Atoll displays total traffic channel quality at the receiver on the carrier ic ( ic BS or ic given ). For further details on formulas, see "Definitions and Formulas" on page 340. For further details on calculation, see "Downlink Sub-Menu" on page 395. You may choose following display options: •
Single colour DL
DL
DL
Atoll displays a coverage with a unique colour if Q MAX ic FCH Q req FCH . Q req FCH is the downlink traffic data quality target on the fundamental channel (FCH). This parameter is user-defined for a given service and a terminal in the Services subfolder. •
Colour per transmitter DL
DL
Atoll displays a coverage if Q MAX ic FCH Q req FCH . Coverage consists of several layers with associated colours. There is a layer per transmitter with no intersection between layers. Layer colour is the colour assigned to best serving transmitter. •
Colour per mobility
In this case, receiver is not completely defined and no mobility is assigned. Coverage consists of several layers with a layer per DL
DL
user-defined mobility defined in Mobility sub-folder. For each layer, area is covered if Q MAX ic FCH Q req FCH . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per service
In this case, receiver is not completely defined and no service is assigned. Coverage consists of several layers with a layer per DL
DL
user-defined service defined in Services sub-folder. For each layer, area is covered if Q MAX ic FCH Q req FCH . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per probability
This display option is available only if analysis is based on all simulations in a group (i.e. if you select a group of simulations and the “All” option in the Condition tab of prediction properties). Coverage consists of several layers with a layer per user-defined probability level defined in the Display tab (Prediction DL
DL
properties). For each layer, area is covered if Q MAX ic FCH Q req FCH in the required number of simulations. Each layer is assigned a colour and displayed with intersections between layers. •
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Coverage consists of several layers with a layer per user-defined cell edge coverage probability, p, defined in the Display tab DL
DL
(Prediction properties). For each layer, area is covered if Q MAX ic p FCH Q req FCH . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per maximum quality level (max Eb/Nt)
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction DL
properties). For each layer, area is covered if Q MAX ic FCH Threshold . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per effective quality level (Effective Eb/Nt)
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction DL
properties). For each layer, area is covered if Q eff ic FCH Threshold . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per quality margin (Eb/Nt margin)
Coverage consists of several layers with a layer per user-defined quality margin defined in the Display tab (Prediction DL
DL
properties). For each layer, area is covered if Q MAX ic FCH – Q req FCH M arg in . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per required power req
Atoll calculates the downlink power required on FCH, P FCH ic , as follows: DL
Q req FCH req - P max P FCH ic = ---------------------FCH DL Q MAX ic max
Where P FCH is a user-defined input for a given service and terminal. It corresponds to the maximum traffic data power allowed on FCH for a transmitter. Coverage consists of several layers with a layer per user-defined required power threshold defined in the Display tab req
(Prediction properties). For each layer, area is covered if P FCH ic Threshold . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per required power margin
Coverage consists of several layers with a layer per user-defined power margin defined in the Display tab (Prediction max
req
properties). For each layer, area is covered if P FCH – P FCH ic M arg in . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per throughput
This display option is relevant for CDMA2000 1xRTT data services only. For each possible throughput, TP FCH
DL
FCH
DL
FCH
DL
FCH
DL
FCH
DL
( TP P – DL AF FCH ,
DL
TP P – DL AF FCH + 2 , TP P – DL AF FCH + 4 , TPP – DL AF FCH + 8 , TP P – DL AF FCH + 16 ), Atoll calculates traffic channel quality at the receiver for each cell (k,ic) (with ic=icBS or icgiven). Downlink traffic channel quality at the receiver is evaluated from a maximum traffic channel power per transmitter allowed for the corresponding throughput. Then, the total DL
DL
downlink traffic channel quality ( Q MAX ic TP ) is calculated after recombination. Coverage consists of several layers with a layer per possible throughput, TP DL Q MAX ic DL
DL
TP
DL DL Q req TP
DL
. For each layer, area is covered if
. Each layer is assigned a colour and displayed with intersections between layers.
DL
Q req TP is the downlink traffic data quality target for the throughput, TP
DL
. This parameter is user-defined for a given
service, terminal and throughput in the Services sub-folder.
5.5.2.2.2
CDMA2000 1xEV-DO E As in point analysis, Atoll calculates the effective pilot quality level at the receiver from the best server cell, ----c- ic b pilot . Best Nt server and active set determination is performed as in point prediction (AS analysis). Then, from this value, it determines the effective downlink throughput received, TP
DL
.
For further details on formulas, see "Definitions and Formulas" on page 340. For further details on calculations, see "Downlink Sub-Menu" on page 395.
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1xEV-DO Rev. 0 Users For 1xEV-DO Rev. 0 users (users with EV-DO Rev. 0-capable terminals and EV-DO Rev. 0 services), the obtained throughput ( TP
DL
) on downlink is determined from the graph “Peak throughput=f(C/I) (Rev0)” defined for the mobility type selected in
the Condition tab (Prediction properties). TP
DL
is the value read in the graph “Peak throughput=f(C/I) (Rev0)” for the
E calculated effective pilot quality level, ----c- ic BS b pilot . Nt 1xEV-DO Rev. A Users For 1xEV-DO Rev. A users (users with EV-DO Rev. A-capable terminals and EV-DO Rev. A services), the obtained throughput ( TP
DL
) on downlink depends on the downlink transmission format, i.e the radio bearer index ( Index DL – Bearer ) with the
Ec C number of timeslots ( n TS ). Atoll selects the downlink transmission format where ----- ic BS b pilot --- . Then, it Nt I req determines the downlink obtained throughput as follows: TP
DL
DL
TP P – RLC Index DL – Bearer = -------------------------------------------------------------. n TS
The obtained throughput corresponds to the guaranteed throughput after a certain number of retransmissions (i.e. the number of timeslots, n TS ). When HARQ (Hybrid Automatic Repeat Request) is used, the required average number of retransmissions is smaller and the DL
throughput is an average throughput ( TP av ) calculated as follows: DL
TP P – RLC Index DL – Bearer DL TP av = --------------------------------------------------------------------DL n Rtx (Index DL – Bearer,n TS) av DL
The average number of retransmissions ( n Rtx av ) is determined from early termination probabilities defined for the selected downlink transmission format. The Early Termination Probability graph shows the probability of early termination ( p ) as a DL
DL
function of the number of retransmissions ( n Rtx ). Atoll calculates the average number of retransmissions ( n Rtx av ) as follows: n DL Rtx max
DL
n
DL
DL
DL
DL
p n Rtx – p n Rtx – 1 n Rtx
=1
Rtx n Rtx av = -------------------------------------------------------------------------------------------DL p n Rtx max
1xEV-DO Rev. B Users Single-carrier EV-DO Rev. B service users are managed as 1xEV-DO Rev. A service users. For multi-carrier EV-DO Rev. B service users, the obtained throughput ( TP obtained throughputs on each carrier.
DL
) in the downlink corresponds to the sum of the
DL
The obtained throughput ( TP ic ) on a carrier depends on the downlink transmission format, i.e the radio bearer index ( Index DL – Bearer ) with the number of timeslots ( n TS ). Atoll selects the downlink transmission format where E ----c- ic b pilot C --- I req and whose modulation scheme is supported by the terminal. Nt The downlink obtained throughput corresponds to the guaranteed throughput after a certain number of retransmissions (i.e. the number of timeslots, n TS ). It is determined as follows: DL
TP P – RLC Index DL – Bearer DL TP ic = -------------------------------------------------------------n TS When HARQ (Hybrid Automatic Repeat Request) is used, the required average number of retransmissions is smaller and the DL
throughput on a carrier is an average throughput ( TP av ic ) calculated as follows:
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TP P – RLC Index DL – Bearer DL TP av ic = --------------------------------------------------------------------DL n Rtx (Index DL – Bearer,n TS) av DL
The average number of retransmissions ( n Rtx av ) is determined from early termination probabilities defined for the selected downlink transmission format. The Early Termination Probability graph shows the probability of early termination ( p ) as a DL
DL
function of the number of retransmissions ( n Rtx ). Atoll calculates the average number of retransmissions ( n Rtx av ) as follows: n DL Rtx max
DL
n
DL
DL
DL
DL
p n Rtx – p n Rtx – 1 n Rtx
=1
Rtx n Rtx av = -------------------------------------------------------------------------------------------DL p n Rtx max DL
The average throughput ( TP av ) provided on downlink corresponds to the sum of the average throughputs obtained on each carrier. Display Options You may choose the following display options: •
Colour per C/I
Coverage consists of several layers with a layer per quality threshold defined in the Display tab (Prediction properties). For E each layer, area is covered if ----c- ic b pilot Threshold . Each layer is assigned a colour and displayed with intersections Nt between layers. •
Colour per throughput
Coverage consists of several layers with a layer per possible throughput ( TP throughput, TP •
DL
DL
). For each layer, area is covered if the
, can be obtained. Each layer is assigned a colour and displayed with intersections between layers.
Colour per average throughput
This display option is available for 1xEV-DO Rev. A and 1xEV-DO Rev. B users only. It enables you to view the obtained downlink DL
throughput when HARQ is used. Coverage consists of several layers with a layer per possible average throughput ( TP av ). For DL
each layer, area is covered if the average throughput, TP av , can be obtained. Each layer is assigned a colour and displayed with intersections between layers.
5.5.2.3 Uplink Service Area Analysis The results displayed when calculating the uplink service area analysis depend on the studied network (CDMA2000 1xRTT or CDMA2000 1xEV-DO).
5.5.2.3.1
CDMA2000 1xRTT As in point analysis, Atoll calculates uplink quality on FCH from receiver for each cell (l,ic) (with ic=icBS or icgiven) in receiver active set. No power control simulation is performed. Atoll determines uplink quality on FCH at the transmitter for the UL
maximum terminal power. Then, the total uplink traffic channel quality ( Q MAX ic FCH ) is evaluated with respect to the receiver handover status. Best server and active set determination is performed as in point prediction (AS analysis).
Atoll displays uplink quality on FCH at transmitters in active set on the carrier ic ( ic BS or ic given ) received from the receiver. For further details on formulas, see "Definitions and Formulas" on page 340. For further details on calculations, see "Uplink Sub-Menu" on page 402. •
Single colour
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UL
UL
UL
Atoll displays a coverage if Q MAX ic FCH Q req FCH . Coverage colour is unique. Q req FCH is the uplink data traffic quality target on the fundamental channel (FCH). This parameter is user-defined for a given service and a terminal in the Services subfolder. •
Colour per transmitter UL
UL
Atoll displays a coverage if Q MAX ic FCH Q req FCH . Coverage consists of several layers with associated colours. There is a layer per transmitter with no intersection between layers. Layer colour is the colour assigned to best server transmitter. •
Colour per mobility
In this case, receiver is not completely defined and no mobility is assigned. Coverage consists of several layers with a layer per UL
UL
user-defined mobility defined in Mobility sub-folder. For each layer, area is covered if Q MAX ic FCH Q req FCH . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per service
In this case, receiver is not completely defined and no service is assigned. Coverage consists of several layers with a layer per UL
UL
user-defined service defined in Services sub-folder. For each layer, area is covered if Q MAX ic FCH Q req FCH . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per probability
This display option is available only if analysis is based on all simulations in a group (i.e. if you select a group of simulations and the “All” option in the Condition tab of prediction properties). Coverage consists of several layers with a layer per userdefined probability level defined in the Display tab (Prediction properties). For each layer, area is covered if UL
UL
Q MAX ic FCH Q req FCH in the required number of simulations. Each layer is assigned a colour and displayed with intersections between layers. •
Colour per cell edge coverage probability
Coverage consists of several layers with a layer per user-defined cell edge coverage probability, p, defined in the Display tab UL
UL
(Prediction properties). For each layer, area is covered if Q MAX ic p FCH Q req FCH . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per maximum quality level (Max Eb/Nt)
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction UL
properties). For each layer, area is covered if Q MAX ic FCH Threshold . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per effective quality level (Effective Eb/Nt)
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction UL
properties). For each layer, area is covered if Q effective ic FCH Threshold . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per quality margin (Eb/Nt margin)
Coverage consists of several layers with a layer per user-defined quality margin defined in the Display tab (Prediction UL
UL
properties). For each layer, area is covered if Q MAX ic FCH – Q req FCH M arg in . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per required power FCH – re q
The required terminal power, P term
, is calculated as described in the Point analysis – AS analysis tab – Uplink sub-menu
part. Coverage consists of several layers with a layer per user-defined power threshold defined in the Display tab (Prediction FCH –re q
properties). For each layer, area is covered if P term
ic Threshold . Each layer is assigned a colour and displayed with
intersections between layers. •
Colour per required power margin
Coverage consists of several layers with a layer per user-defined power margin defined in the Display tab (Prediction max
FCH –re q
properties). For each layer, area is covered if P term – P term with intersections between layers. •
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Colour per throughput
ic M arg in . Each layer is assigned a colour and displayed
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This display option is relevant for CDMA2000 1xRTT data services only. For each possible throughput, TP FCH
UL
FCH
UL
FCH
UL
FCH
UL
FCH
UL
( TP P – UL AF FCH ,
UL
TP P – UL AF FCH + 2 , TP P – UL AF FCH + 4 , TP P – UL AF FCH + 8 , TP P – UL AF FCH + 16 ), Atoll calculates the total UL
UL
uplink traffic channel quality ( Q MAX ic TP ). Coverage consists of several layers with a layer per possible throughput, TP
UL
UL
UL
UL
UL
. For each layer, area is covered if Q MAX ic TP Q req TP . Each layer is assigned a colour and displayed with UL
UL
intersections between layers. Q req TP is the uplink traffic data quality target for the throughput, TP
UL
. This parameter is
user-defined for the service, a given terminal and throughput in the service properties.
5.5.2.3.2
CDMA2000 1xEV-DO As in point analysis, Atoll calculates the uplink quality from receiver for each cell (l,ic) (with ic=icBS or icgiven) in receiver active set. No power control simulation is performed. For 1xEV-DO Rev. 0 users, Atoll determines the uplink quality at the transmitter for the maximum terminal power allowed and an uplink channel throughput of 9.6 kbps. For 1xEV-DO Rev. A and 1xEV-DO Rev. B users, Atoll determines the uplink quality at the transmitter for the maximum terminal power allowed and an UL
uplink channel throughput of 4.8 kbps. Then, the total uplink quality ( Q MAX ic ) is evaluated with respect to the receiver handover status. Best server and active set determination is performed as in point prediction (AS analysis).
Atoll displays the uplink quality at transmitters in active set on the carrier ic ( ic BS or ic given ) received from the receiver. For multi-carrier EV-DO users, Atoll considers the best sub-active set. For further details on formulas, see "Definitions and Formulas" on page 340. For further details on calculations, see "Uplink Sub-Menu" on page 402. •
Single colour UL
UL
UL
Atoll displays a coverage if Q MAX ic Q req . Coverage colour is unique. For 1xEV-DO Rev. 0 users, Q req is the quality required UL
on uplink for a 9.6 kbps channel throughput. For 1xEV-DO Rev. A and 1xEV-DO Rev. B users, Q req is the quality required on uplink for a 4.8 kbps channel throughput. This parameter is calculated from the minimum uplink pilot quality and gains on the different uplink channels. We have: E UL UL UL Q req = ----c- G p 1 + G ACK + G DRC + G TCH for 1xEV-DO Rev. 0 terminals, N t min And E UL UL UL Q req = ----c- G p 1 + G ACK + G RRI + G DRC + G TCH + G Auxiliary – Pilot for 1xEV-DO Rev. A and 1xEV-DO Rev. B terminals. N t min •
Colour per transmitter UL
UL
Atoll displays a coverage if Q MAX ic Q req . Coverage consists of several layers with associated colours. There is a layer per transmitter with no intersection between layers. Layer colour is the colour assigned to best server transmitter. •
Colour per mobility
In this case, receiver is not completely defined and no mobility is assigned. Coverage consists of several layers with a layer per UL
UL
user-defined mobility defined in Mobility sub-folder. For each layer, area is covered if Q MAX ic Q req . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per service
In this case, receiver is not completely defined and no service is assigned. Coverage consists of several layers with a layer per UL
UL
user-defined service defined in Services sub-folder. For each layer, area is covered if Q MAX ic Q req . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per probability
This display option is available only if analysis is based on all simulations in a group (i.e. if you select a group of simulations and the “All” option in the Condition tab of prediction properties). Coverage consists of several layers with a layer per user-
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UL
defined probability level defined in the Display tab (Prediction properties). For each layer, area is covered if Q MAX ic Q req in the required number of simulations. Each layer is assigned a colour and displayed with intersections between layers. •
Colour per cell edge coverage probability
Coverage consists of several layers with a layer per user-defined cell edge coverage probability, p, defined in the Display tab UL
UL
(Prediction properties). For each layer, area is covered if Q MAX ic p Q req . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per maximum quality level (Max Eb/Nt) UL
Here, Atoll calculates the total uplink traffic channel quality ( Q MAX ic TCH ). UL
Q req TCH UL - P max Q MAX ic TCH = ---------------------term req P term With UL
E UL UL Q req TCH = ----c- G p G TCH N t min Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction UL
properties). For each layer, area is covered if Q MAX ic TCH Threshold . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per effective quality level (Effective Eb/Nt)
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction UL
properties). For each layer, area is covered if Q effective ic TCH Threshold . Each layer is assigned a colour and displayed with intersections between layers. UL
UL
UL
Q effective ic TCH = min Q MAX ic TCH Q req TCH •
Colour per quality margin (Eb/Nt margin)
Coverage consists of several layers with a layer per user-defined quality margin defined in the Display tab (Prediction UL
UL
properties). For each layer, area is covered if Q MAX ic – Q req M arg in . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per required power
1xEV-DO Rev. 0, 1xEV-DO Rev.A and single-carrier 1xEV-DO Rev. B service users Coverage consists of several layers with a layer per user-defined power threshold defined in the Display tab (Prediction TCH – re q
properties). For each layer, area is covered if P term
ic Threshold . Each layer is assigned a colour and displayed with
intersections between layers. TCH –re q
The required terminal power on traffic data channel, P term
, is calculated as described in the Point analysis – AS analysis
tab – Uplink sub-menu part. TCH – re q
P term
req
P term = --------------------------------------------------------- G TCH for 1xEV-DO Rev. 0 terminals, 1 + G ACK + G DRC + G TCH
And TCH – re q
P term
req
P term - G TCH for 1xEV-DO Rev. A terminals. = ------------------------------------------------------------------------------------------------------------------1 + G ACK + G RRI + G DRC + G TCH + G Auxiliary – Pilot
Multi-carrier 1xEV-DO Rev. B service users For multi-carrier EV-DO users, the coverage consists of several layers with a layer per user-defined power threshold defined TCH –re q
in the Display tab (Prediction properties). For each layer, area is covered if P term
Threshold . Each layer is assigned a
colour and displayed with intersections between layers. TCH – re q
For the selected configuration (i.e., the combination of carriers which provides the highest throughput), P term to the sum of the terminal powers required on each carrier of the configuration. •
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Coverage consists of several layers with a layer per user-defined power margin defined in the Display tab (Prediction max
req
properties). For each layer, area is covered if P term – P term ic M arg in . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per throughput
1xEV-DO Rev. 0 service users For each possible throughput, TP
UL
UL
UL
, Atoll calculates the total uplink quality ( Q MAX ic TP ). Coverage consists of several UL
UL
UL
UL
layers with a layer per possible throughput. For each layer, area is covered if Q MAX ic TP Q req TP . Each layer is assigned a colour and displayed with intersections between layers. UL
UL
Q req TP is the uplink quality required to obtain the throughput, TP The possible throughputs on uplink, TP
UL
UL
.
, are: 9.6, 19.2, 38.4, 76.8 and 153.6 kbps
E UL UL UL Q req = ----c- G p 1 + G ACK + G DRC + G TCH N t min Where Ec --- N t min is the minimum pilot quality level on uplink. This parameter is available in the Mobility types table. UL
G ACK , G DRC and G TCH are respectively acknowledgement, data rate control and traffic data gains relative to the pilot. They are defined in the terminal properties (1xEV-DO Rev. 0 tab). 1xEV-DO Rev. A and single-carrier 1xEV-DO Rev. B service users For each possible throughput, TP
UL
UL
UL
, Atoll calculates the total uplink quality ( Q MAX ic TP ). Coverage consists of several UL
UL
UL
UL
layers with a layer per possible throughput. For each layer, area is covered if Q MAX ic TP Q req R v . Each layer is assigned a colour and displayed with intersections between layers. UL
UL
Q req TP is the uplink quality required to obtain the throughput, TP The throughput, TP
UL
UL
.
is obtained when a certain uplink transmission format (i.e. 1xEV-DO radio bearer ( Index UL – Bearer )
with a certain number of subframes ( n SF )) is used. It is calculated as follows: UL
TP P – RLC Index UL – Bearer UL TP req = -------------------------------------------------------------n SF E UL UL UL Q req = ----c- G p 1 + G ACK + G DRC + G TCH + G RRI + G Auxiliary – pilot N t min Where Ec UL --- N t min is the minimum pilot quality level required on uplink to obtain the throughput, TP . The value is defined in the UL
1xEV-DO Radio Bearer Selection (Uplink) table for the uplink transmission format (radio bearer Index, mobility and number of subframe). Two values are available for this parameter, one when the service uplink mode is "Low Latency" and another one for high capacity services. G ACK , G DRC , G TCH , G RRI and G Auxiliary – pilot are respectively acknowledgement, data rate control, traffic data channel, reverse rate indicator and auxiliary pilot channel gains relative to the pilot. They are defined in the terminal properties (1xEVDO Rev. A tab). Two values of G TCH are available, one when the service uplink mode is "Low Latency" and another one for high capacity services. Multi-carrier 1xEV-DO Rev. B service users For multi-carrier 1xEV-DO Rev. B users, Atoll models load balancing between carriers. Atoll allocates the available terminal power to carriers sequentially and determines the uplink 1xEV-DO radio bearer obtained on each carrier. Then, it selects the best configuration among all combinations of carriers, i.e., the combination which provides the highest throughput. Coverage consists of several layers with a layer per possible throughput. For each layer, area is covered if TP
UL
UL
TP req . Each
layer is assigned a colour and displayed with intersections between layers.
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UL
TP req is the uplink throughput associated with the layer. TP
UL
•
corresponds to the throughput of the best configuration, i.e., the combination which provides the highest throughput. Colour per average throughput
This display option is available for 1xEV-DO Rev. A and 1xEV-DO Rev. B users only. When HARQ (Hybrid Automatic Repeat Request) is used, the required average number of retransmissions is smaller and the throughput is an average throughput UL
( TP av ) calculated as follows: UL
TP P – RLC Index UL – Bearer UL TP av = ----------------------------------------------------------------------UL n Rtx Index UL – Bearer n SF av UL
The average number of retransmissions ( n Rtx av ) is determined from early termination probabilities defined for the selected uplink transmission format (i.e. the radio bearer index ( Index UL – Bearer ) with the number of subframes ( n SF )). The Early Termination Probability graph shows the probability of early termination ( p ) as a function of the number of retransmissions UL
UL
( n Rtx ). Atoll calculates the average number of retransmissions ( n Rtx av ) as follows: n UL Rtx max
n
UL
UL
UL
UL
UL
p n Rtx – p n Rtx – 1 n Rtx
=1
Rtx n Rtx av = -------------------------------------------------------------------------------------------UL p n Rtx max
1xEV-DO Rev. A and single-carrier 1xEV-DO Rev. B service users UL
UL
UL
For each possible average throughput, TP av , Atoll calculates the total uplink quality ( Q MAX ic TP av ). Coverage consists of UL
UL
UL
UL
several layers with a layer per possible average throughput. For each layer, area is covered if Q MAX ic TP av Q req TP av . Each layer is assigned a colour and displayed with intersections between layers. UL
UL
UL
Q req TP av is the uplink quality required to obtain the average throughput, TP av . Multi-carrier 1xEV-DO Rev. B service users For multi-carrier 1xEV-DO Rev. B users, the coverage consists of several layers with a layer per possible throughput. For each UL
UL
layer, area is covered if TP av TP req . Each layer is assigned a colour and displayed with intersections between layers. UL
TP req is the uplink throughput associated with the layer. UL
For the selected configuration (i.e., the combination of carriers which provides the highest throughput), TP av corresponds to the sum of the average throughputs obtained on each carrier of the configuration.
5.5.2.4 Downlink Total Noise Analysis Atoll determines downlink total noise generated by cells. For CDMA2000 1xRTT systems, we have:
Ptot icadj DL
DL
N tot ic =
txj j + N0 Ptot ic + -----------------------------------RF ic ic adj DL
term
txj j
For CDMA2000 1xEV-DO systems, we have:
Ptot icadj bpilot DL
DL
N tot ic =
txj j - + N0 Ptot ic bpilot + --------------------------------------------------RF ic ic adj DL
term
txj j
term
N0 DL - Downlink noise rise, NR DL ic , is calculated from the downlink total noise, N tot , as: NR DL ic = – 10 log ----------- N DL tot
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5.5.2.4.1
Analysis on the Best Carrier If the best carrier is selected, Atoll determines DL total noise for the best carrier. Then, allows the user to choose different displays. •
Colour per minimum noise level
Coverage consists of several layers with a layer per user-defined noise level defined in the Display tab (Prediction properties). DL
For each layer, area is covered if min NR tot ic Threshold . Each layer is assigned a colour and displayed with ic
intersections between layers. •
Colour per maximum noise level
Coverage consists of several layers with a layer per user-defined noise level defined in the Display tab (Prediction properties). DL
For each layer, area is covered if max NR tot ic Threshold . Each layer is assigned a colour and displayed with intersections ic
between layers. •
Colour per average noise level
Coverage consists of several layers with a layer per user-defined noise level defined in the Display tab (Prediction properties). DL
For each layer, area is covered if average NRtot ic Threshold . Each layer is assigned a colour and displayed with ic
intersections between layers. •
Colour per minimum noise rise
Atoll displays bins where min NR DL ic Threshold . Coverage consists of several areas with an area per user-defined noise ic
rise threshold defined in the Display tab. Each area is assigned a colour with intersections between areas. •
Colour per maximum noise rise
Atoll displays bins where max NR DL ic Threshold . Coverage consists of several areas with an area per user-defined noise ic
rise threshold defined in the Display tab. Each area is assigned a colour with intersections between areas. •
Colour per average noise rise
Atoll displays bins where average NRDL ic Threshold . Coverage consists of several areas with an area per user-defined ic
noise rise threshold defined in the Display tab. Each area is assigned a colour with intersections between areas.
5.5.2.4.2
Analysis on a Specific Carrier When only one carrier is analysed, Atoll determines DL total noise or DL noise rise on this carrier. In this case, the displayed coverage is the same for any selected display per noise level (average, minimum or maximum) or any display per noise rise (average, minimum or maximum). •
Colour per noise level
Coverage consists of several layers with a layer per user-defined noise level defined in the Display tab (Prediction properties). DL
For each layer, area is covered if N tot ic Threshold . Each layer is assigned a colour and displayed with intersections between layers. •
Colour per noise rise
Atoll displays bins where NRDL ic Threshold . Coverage consists of several areas with an area per user-defined noise rise threshold defined in the Display tab. Each area is assigned a colour with intersections between areas.
5.6 Automatic Neighbour Allocation Atoll permits the automatic allocation of intra-technology neighbours in the current network. Two allocation algorithms are available, one dedicated to intra-carrier neighbours and the other for inter-carrier neighbours. The intra-technology neighbour allocation algorithms take into account all the cells of TBC transmitters. It means that all the cells of TBC transmitters of your .atl document are potential neighbours. The cells to be allocated will be called TBA cells. They must fulfill the following conditions: • • •
They are active, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone,
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They belong to the folder on which allocation has been executed. This folder can be either the Transmitters folder or a group of transmitters or a single transmitter.
Only TBA cells may be assigned neighbours. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
In this section, the following are explained: • • •
"Neighbour Allocation for all Transmitters" on page 424. "Neighbour Allocation for a Group of Transmitters or One Transmitter" on page 427. "Importance Calculation" on page 428.
5.6.1 Neighbour Allocation for all Transmitters We assume that we have a reference cell A and a candidate neighbour, cell B. When automatic allocation starts, Atoll checks following conditions: •
The distance between both cells must be less than the user-definable maximum inter-site distance. If the distance between the reference cell and the candidate neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance, which corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 430.
•
The calculation options: • Carriers: This option enables you to select the carrier(s) on which you want to run the allocation. You may choose one or more carriers. Atoll will allocate neighbours to cells using the selected carriers. • Force co-site cells as neighbours: This option enables you to force cells located on the reference cell site in the candidate neighbour list. This constraints can be weighted among the others and ranks the neighbours through the importance field (see after). • Force adjacent cells as neighbours (only for intra-carrier neighbours): This option enables you to force cells geographically adjacent to the reference cell in the candidate neighbour list.This constraints can be weighted among the others and ranks the neighbours through the importance field (see after). • Force symmetry: This option enables user to force the reciprocity of a neighbourhood link. Therefore, if the reference cell is a candidate neighbour of another cell, this one will be considered as candidate neighbour of the reference cell. If the neighbours list of a cell is full, the reference cell will not be added as a neighbour of that cell and that cell will be removed from the reference cell’s neighbours list. You can force Atoll to keep that cell in the reference cell’s neighbours list by adding the following option in the Atoll.ini file: [Neighbours] DoNotDeleteSymmetrics = 1 • •
Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may force/forbid a cell to be candidate neighbour of the reference cell. Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, the existing neighbours are kept. Adjacency criterion: Let CellB be a candidate neighbour cell of CellA. CellB is considered adjacent to CellA if there exists at least one pixel in the CellA Best Server coverage area where CellB is Best Server (if several cells have the same best server value) or CellB is the second best server that enters the Active Set (respecting the T_Drop of the allocation). When the Force adjacent cells as neighbours check box is selected, adjacent cells are sorted and listed from the most adjacent to the least, depending on the above criterion. Adjacence is relative to the number of pixels satisfying the criterion.
•
If the Use Coverage Conditions check box is selected, there must be an overlapping zone ( S A S B ) with a given cell edge coverage probability. Otherwise, only the distance criterion is taken into account.
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The overlapping zone ( S A S B ) is defined as follows: •
Intra-carrier neighbours: intra-carrier handover is a soft handover.
The reference cell A and the candidate cell B are located inside a continuous layer of cells with carrier c1 (c1 is the selected carrier on which you run the allocation). SA is the area where the cell A is the best serving cell. It means that the cell A is the first one in the active set. • • •
The pilot signal received from the cell A is greater than the minimum pilot signal level. The pilot quality from A exceeds Min. Ec/I0. The pilot quality from A is the best.
SB is the area where the cell B can enter the active set. • • •
The pilot signal received from the cell B is greater than the minimum pilot signal level. The pilot quality from B is greater than T_Drop.
Inter-carrier neighbours: inter-frequency handover is a hard handover. It is needed in a multi-carrier (1xRTT and 1xEVDO carriers) CDMA network: • •
To balance loading between carriers and layers (1st case), To make a coverage reason handover from micro cell frequency to macro cells (2nd case).
1st case: the reference cell A is located inside a continuous layer of cells with carrier c1 (c1 is the selected carrier on which you run the allocation) and the candidate cell B belongs to a layer of cells with carrier c2. SA is the area where: • •
The pilot signal received from the cell A is greater than the minimum pilot signal level. The pilot signal from A is not the highest one. It is strictly lower than the best pilot signal received and higher than the best pilot signal minus the margin.
SB is the area where: • •
The pilot signal received from the cell B is greater than the minimum pilot signal level. The pilot signal from B is the highest one.
Figure 5.4: Overlapping Zones - 1st Case 2nd case: the reference cell A is located on the border of a layer with carrier c1 (c1 is the selected carrier on which you run the allocation) and the candidate cell B belongs to a layer of cells with carrier c2. SA is the area where: • • •
The pilot signal received from the cell A is greater than the minimum pilot signal level. The pilot signal from A is the highest one The pilot signal from A is lower than the minimum pilot signal level plus the margin.
SB is the area where: • •
The pilot signal received from the cell B is greater than the minimum pilot signal level. The pilot signal from B is the highest one.
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Figure 5.5: Overlapping Zones - 2nd Case Two ways enable you to determine the I0 value: •
•
Global Value: A percentage of the cell maximum power is considered. If the % of maximum power is too low, i.e. if % Pmax P pilot , Atoll takes into account the pilot power of the cell. Then, I0 represents the sum of values calculated for each cell. Defined per Cell: Atoll takes into account the total downlink power defined per cell. I0 represents the sum of total transmitted powers.
SA SB - 100 ) and compares this value to the % minimum covered area. If Atoll calculates the percentage of covered area ( ----------------SA this percentage is not exceeded, the candidate neighbour B is discarded. The coverage condition can be weighted among the others and ranks the neighbours through the importance field (see after). •
The importance of neighbours.
For information on the importance calculation, see "Importance Calculation" on page 428. Importance values are used by the allocation algorithm to rank the neighbours. Atoll lists all neighbours and sorts them by importance value so as to eliminate some of them from the neighbour list if the maximum number of neighbours to be allocated to each transmitter is exceeded. If we consider the case for which there are 15 candidate neighbours and the maximum number of neighbours to be allocated to the reference cell is 8. Among these 15 candidate neighbours, only 8 (having the highest importance values) will be allocated to the reference cell. Note that specific maximum numbers of neighbours (maximum number of intra-carrier neighbours, maximum number of inter-carrier neighbours) can be defined at the cell level (property dialogue or cell table). If defined there, this value is taken into account instead of the default one available in the Neighbour Allocation dialogue. In the Results part, Atoll provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason. Therefore, a neighbour may be marked as exceptional pair, co-site, adjacent, coverage or symmetric. For neighbours accepted for co-site, adjacency and coverage reasons, Atoll displays the percentage of area meeting the coverage conditions and the corresponding surface area (km2), the percentage of area meeting the adjacency conditions and the corresponding surface area (km2). Finally, if cells have previous allocations in the list, neighbours are marked as existing.
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•
By default, the automatic neighbour allocation compares the defined Max intersite distance with the effective inter-cell distance. As a consequence, there can be cases where the real distance between assigned neighbours is higher than the Max inter-site distance, because the effective distance is smaller. You can force Atoll to compare the Max inter-site distance with the real inter-site distance by adding the following lines in Atoll.ini: [Neighbours] RealInterSiteDistanceCondition=1
•
By default, the neighbour importance calculated with respect to distance is based on the global Max inter-site distance setting for all neighbour candidates. As a consequence, there can be cases where the calculated importance is different when the global Max inter-site distance is modified. To avoid that, you can force Atoll to prioritise the individual distances between reference cells and their respective neighbour candidates by adding the following lines in Atoll.ini: [Neighbours] CandidatesMaxDistanceInImportanceCalculation=1
•
•
• • • • •
•
• • •
•
No simulation or prediction study is needed to perform an automatic neighbour allocation. When starting an automatic neighbour allocation, Atoll automatically calculates the path loss matrices if not found. Even if no specific terminal, mobility or service is selected in the automatic allocation, it is interesting to know that the algorithm works such as finding the maximum number of neighbours by selection the multi-service traffic data as follows: Service: selection of the one with the lowest body loss. Mobility: no impact on the allocation, no specific selection. Terminal: selection of the one with the greatest (Gain - Loss) value, and, if equal, the one with the lowest noise figure. The neighbour lists may be optionally used in the power control simulations to determine the mobile's active set. A forbidden neighbour must not be listed as neighbour except if the neighbourhood relationship already exists and the Delete existing neighbours option is unchecked when you start the new allocation. In this case, Atoll displays a warning in the Event viewer indicating that the constraint on the forbidden neighbour will be ignored by algorithm because the neighbour already exists. The force neighbour symmetry option enables the users to consider the reciprocity of a neighbourhood link. This reciprocity is allowed only if the neighbour list is not already full. Thus, if the cell B is a neighbour of the cell A while the cell A is not a neighbour of the cell B, two cases are possible: 1st case: There is space in the cell B neighbour list: the cell A will be added to the list. It will be the last one. 2nd case: The cell B neighbour list is full: Atoll will not include cell A in the list and will cancel the link by deleting cell B from the cell A neighbour list. When the options “Force exceptional pairs” and “Force symmetry” are selected, Atoll considers the constraints between exceptional pairs in both directions so as to respect symmetry condition. On the other hand, if neighbourhood relationship is forced in one direction and forbidden in the other one, symmetry cannot be respected. In this case, Atoll displays a warning in the Event viewer. In the Results, Atoll displays only the cells for which it finds new neighbours. Therefore, if a TBA cell has already reached its maximum number of neighbours before starting the new allocation, it will not appear in the Results table.
5.6.2 Neighbour Allocation for a Group of Transmitters or One Transmitter In this case, Atoll allocates neighbours to: • • •
TBA cells, Neighbours of TBA cells marked as exceptional pair, adjacent and symmetric, Neighbours of TBA cells that satisfy coverage conditions.
Automatic neighbour allocation parameters are described in "Neighbour Allocation for all Transmitters" on page 424.
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5.6.3 Importance Calculation Importance values are used by the allocation algorithm to rank the neighbours according to the allocation reason, and to quantify the neighbour importance.
5.6.3.1 Importance of Intra-carrier Neighbours The neighbour importance depends on the distance from the reference transmitter and on the neighbourhood cause (cf. table below); this value varies between 0 and 100%. Neighbourhood cause
When
Importance value
Existing neighbour
Only if the Delete existing neighbours option is not selected and in case of a new allocation
Existing importance
Exceptional pair
Only if the Force exceptional pairs option is selected
100 %
Co-site cell
Only if the Force co-site cells as neighbours option is selected
Importance Function (IF)
Adjacent cell
Only if the Force adjacent cells as neighbours option is selected
Importance Function (IF)
Neighbourhood relationship that fulfils coverage conditions
Only if the % minimum covered area is exceeded
Importance Function (IF)
Symmetric neighbourhood relationship
Only if the Force neighbour symmetry option is selected
Importance Function (IF)
Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined using the Importance Function (IF). The IF considers the following factors for calculating the importance: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 430. d max is the maximum distance between the reference transmitter and a possible neighbour.
• • •
The co-site factor (C): a Boolean, The adjacency factor (A): the percentage of adjacency, The overlapping factor (O): the percentage of overlapping.
The minimum and maximum importance assigned to each of the above factors can be defined. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
30%
Adjacency factor (A)
Min(A)
30%
Max(A)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The Importance Function is evaluated as follows: Neighbourhood cause
Importance Function
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%Max(Di))(O)}+Min(Di)+Delta(Di)(Di)
10%+20%{10%(Di)+90%(O)}+1%+9%(Di)
No
Yes
Min(A)+Delta(A){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
30%+30%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Yes
Yes
Min(C)+Delta(C){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
60%+40%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Co-site
Adjacent
No
Where: Delta(X)=Max(X)-Min(X)
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• •
•
•
Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours, adjacent neighbours, and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes. The default value of Min(O) = 1% ensures that neighbours selected for symmetry will have an importance greater than 0%. With a value of Min(O) = 0%, neighbours selected for symmetry will have an importance field greater than 0% only if there is some coverage overlapping.
5.6.3.2 Importance of Inter-carrier Neighbours As indicated in the table below, the neighbour importance depends on the distance and on the neighbourhood cause; this value varies between 0 to 100%. Neighbourhood cause
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site cell
If the Force co-site cells as neighbours option is selected
Importance Function (IF)
Neighbourhood relationship that fulfils coverage conditions
If the % minimum covered area is exceeded
Importance Function (IF)
Symmetric neighbourhood relationship
If the Force neighbour symmetry option is selected
Importance Function (IF)
Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined using the Importance Function (IF). The IF considers the following factors for calculating the importance: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 430. d max is the maximum distance between the reference transmitter and a possible neighbour.
• •
The co-site factor (C): a Boolean, The overlapping factor (O): the percentage of overlapping.
The IF is user-definable using the Min importance and Max importance fields. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The IF evaluates importance as follows: Co-site Neighbourhood cause
IF
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%-Max(Di))(O)}
10%+50%{10%(Di)+90%(O)}
Yes
Min(C)+Delta(C){Max(Di)(Di)/(Max(Di)+Max(O))+ Max(O)(O)/(Max(Di)+Max(O))}
60%+40%{1/7%(Di)+6/7%(O)}
Where Delta(X)=Max(X)-Min(X)
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•
•
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Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes. The default value of Min(O) = 1% ensures that neighbours selected for symmetry will have an importance greater than 0%. With a value of Min(O) = 0%, neighbours selected for symmetry will have an importance field greater than 0% only if there is some coverage overlapping.
5.6.4 Appendices 5.6.4.1 Calculation of the Inter-Transmitter Distance Atoll takes into account the real distance ( D in m) and azimuths of antennas in order to calculate the effective intertransmitter distance ( d in m). d = D 1 + x cos – x cos where x = 0.3% so that the maximum D variation does not exceed 1%.
Figure 5.6: Inter-Transmitter Distance Computation The formula above implies that two cells facing each other will have a smaller effective distance than the real physical distance. It is this effective distance that will be taken into account rather than the real distance.
5.7 PN Offset Allocation PN offset is used to identify a cell. It is a time offset used by a cell to shift a Pseudo Noise sequence. Mobile processes the strongest received PN sequence and reads its phase that identifies the cell. There are a maximum of 512 PN offsets numbered from 0 to 511. The cells to which Atoll allocates PN offsets are referred to as the TBA cells (cells to be allocated). TBA cells fulfil following conditions: • • • •
They are active, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone, They belong to the folder on which allocation has been executed. This folder can be either the Transmitters folder or a group of transmitters or a single transmitter. If no focus zone exists in the .atl document, Atoll takes into account the computation zone.
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5.7.1 Automatic Allocation Description 5.7.1.1 Options and Constraints The PN offset allocation algorithm can take into account following constraints and options: •
PILOT_INC parameter, Atoll uses this parameter to determine the pool of possible PN offsets (512 divided by PILOT_INC value). The first PN offset is PILOT_INC and other ones are multiples of this value. For example: When PILOT_INC is set to 4, the pool of possible PN offsets consists of PN offsets from 4 to 508 with a separation interval of 4 (i.e. [4,8,12,16,...508]).
•
Neighbourhood between cells,
You may consider: • • •
First order neighbours: The neighbours of TBA cells listed in the Intra-technology neighbours table, Second order neighbours: The neighbours of neighbours, Third order neighbours: The neighbour’s neighbour’s neighbours. • • •
•
In the context of the PN offset allocation, the term "neighbours" refers to intra-carrier neighbours. Atoll considers symmetry relationship between a cell, its first order neighbours, its second order neighbours and its third order neighbours. In 3GPP2 multi-RAT documents, Atoll also tries to allocate different PN offsets to CDMA cells that are neighbours of a common LTE cell.
Cells fulfilling a criterion on Ec/I0 (option “Additional Ec/I0 conditions”),
Atoll reuses the intra-carrier neighbour allocation algorithm to determine the list of cells which cannot be allocated the same scrambling code, and to calculate their importance. For a reference cell “A”, Atoll considers all the cells “B” that can enter the active set on the area where the reference cell is the best server (area where (Ec/I0)A exceeds Min. Ec/I0 and is the highest one and (Ec/I0)B exceeds T_Drop). Atoll considers either a percentage of the cell maximum powers or the total downlink power used by the cells in order to evaluate I0. In this case, I0 equals the sum of total transmitted powers. When this parameter is not specified in the cell properties, Atoll uses 50% of the maximum power. •
Co-PN Reuse distance,
Reuse distance is a constraint on the allocation of PN offsets. A PN offset cannot be reused at a site that is not at least as far away as the reuse distance from the site allocated with the particular PN offset. PN offset reuse distance can be defined at cell level. If this value is not defined, then Atoll will use the default reuse distance defined in the PN offset Automatic Allocation dialogue. • • •
PN-cluster size. Within the context of PN offset allocation, the term "PN-cluster" refers to a sub-group of PN offsets. Exceptional pairs, Domains of PN offsets, When no domain is assigned to cells, Atoll considers the PILOT_INC parameter only to determine available PN offsets (e.g., If PILOT_INC is set to 4, all PN offsets from 4 to 508 with a separation interval of 4 can be allocated).
•
• •
The carrier on which the allocation is run: It can be a given carrier or all of them. In this case, either Atoll independently plans PN offsets for the different carriers, or it allocates the same PN offset to each carrier of a transmitter if the option "Allocate carriers identically" is selected. The possibility to use a maximum of PN offsets (option "Use a Maximum of PN Offsets"): Atoll will try to spread the PN offset spectrum the most. The "Delete All Codes" option: When selecting this option, Atoll deletes all the current PN offsets and carries out a new PN offset allocation. If not selected, the existing PN offsets are kept.
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In addition, it depends on the selected allocation strategy. Allocation strategies can be: • •
•
PN offset per cell: The purpose of this strategy is to reduce the spectrum of allocated PN offsets the maximum possible. Atoll will allocate the first possible PN offsets in the domain. Adjacent PN-Clusters per site: This strategy consists of allocating one cluster of adjacent PN offsets to each site, then, one PN offset of the cluster to each cell of each transmitter according to its azimuth. When all the clusters have been allocated and there are still sites remaining to be allocated, Atoll reuses the clusters at another site. Distributed PN-clusters per site: This strategy consists of allocating one cluster of PN offsets to each site in the network, then, one PN offset of the cluster to each cell of each transmitter according to its azimuth. With this strategy, the cluster is made of PN offsets separated as much as possible. When all the clusters have been allocated and there are still sites remaining to be allocated, Atoll reuses the clusters at another site.
In the Results table, Atoll only displays PN offsets allocated to TBA cells.
5.7.1.2 Allocation Process For each TBA cell, Atoll lists all cells which have constraints with the cell. They are referred to as near cells. The near cells of a TBA cell may be: • • • • • •
Its neighbour cells: the neighbours listed in the Intra-technology neighbours table (options “Existing neighbours” and "First Order"), The neighbours of its neighbours (options “Existing neighbours” and “Second Order”), The third order neighbours (options “Existing neighbours” and “Third Order”), The cells that fulfil Ec/I0 condition (option “Additional Ec/I0 conditions”), The cells with distance from the TBA cell less than the reuse distance, The cells that make exceptional pairs with the TBA cell.
One additional constraint is considered in 3GPP2 multi-RAT documents: •
The cell and its near cells are neighbours of the same LTE cell.
These constraints have a certain weight taken into account to determine the TBA cell priority during the allocation process and the cost of the PN offset plan. During the allocation, Atoll tries to assign different PN offsets to the TBA cell and its near cells. If it respects all the constraints, the cost of the PN offset plan is 0. When a cell has too many constraints and there are not anymore PN offsets available, Atoll breaks the constraint with the lowest cost so as to generate the PN offset plan with the lowest cost. For information on the cost generated by each constraint, see "Cell Priority" on page 433.
5.7.1.2.1
Single Carrier Network The allocation process depends on the selected strategy. Algorithm works as follows: Strategy: PN offset per cell Atoll processes TBA cells according to their priority. It allocates PN offsets starting with the highest priority cell and its near cells, and continuing with the lowest priority cells not allocated yet and their near cells. For information on calculating cell priority, see "Cell Priority" on page 433. Strategy: Adjacent PN-Clusters per site All sites which have constraints with the studied site are referred to as near sites. Atoll assigns a PN-cluster of adjacent PN offsets to each site, starting with the highest priority site and its near sites, and continuing with the lowest priority sites not allocated yet and their near sites. When all the clusters have been allocated and there are still sites remaining to be allocated, Atoll reuses the clusters at another site. When the Co-PN Reuse Distance option is selected, the algorithm reuses the clusters as soon as the Co-PN reuse distance is exceeded. Otherwise, when the option is not selected, the algorithm tries to assign reused clusters as spaced out as possible. Then, Atoll allocates a PN offset from the cluster to each cell of each transmitter located on the sites according to the transmitter azimuth. It starts with the highest priority cell and its near cells and goes on with the lowest priority cells not allocated yet and their near cells. For information on calculating site priority, see "Site Priority" on page 436. For information on calculating cell priority, see "Cell Priority" on page 433. Strategy: Distributed PN-Clusters per site All sites which have constraints with the studied site are referred to as near sites. Atoll assigns one cluster to each site, starting with the highest priority site and its near sites, and continuing with the lowest priority sites not allocated yet and their near sites. When all the clusters have been allocated and there are still sites remaining to be allocated, Atoll reuses the clusters at another site. When the Co-PN Reuse Distance option is selected, the algorithm reuses the clusters as soon as the Co-PN reuse distance is exceeded. Otherwise, when the option is not selected, the algorithm tries to assign reused clusters as spaced out as possible.
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Then, Atoll assigns a PN offset from the cluster to each cell of each transmitter located on the sites according to the transmitter azimuth. It starts with the highest priority cell and its near cells and goes on with the lowest priority cells not allocated yet and their near cells. For information on calculating site priority, see "Site Priority" on page 436. For information on calculating cell priority, see "Cell Priority" on page 433.
5.7.1.2.2
Multi-Carrier Network In case you have a multi-carrier network and you run the PN offset allocation on all the carriers, the allocation process depends on wether the option "Allocate Carriers Identically" is selected or not. When the option is not selected, algorithm works for each strategy, as explained above. On the other hand, when the option is selected, allocation order changes. It is no longer based on the cell priority but depends on the transmitter priority. All transmitters which have constraints with the studied transmitter will be referred to as near transmitters. In case of a "Per cell" strategy (PN offset per cell), Atoll starts PN offset allocation with the highest priority transmitter and its near transmitters and continues with the lowest priority transmitters not allocated yet and their near transmitters. The same PN offset is assigned to each cell of the transmitter. In case of a "Per site" strategy (Adjacent and Distributed PN-clusters per site strategies), Atoll assigns a cluster to each site and then, allocates a PN offset to each transmitter. It starts with the highest priority transmitter and its near transmitters and continues with the lowest priority transmitters not allocated yet and their near transmitters. The same PN offset is assigned to each cell of the transmitter. For information on calculating cell priority, see "Cell Priority" on page 433. For information on calculating transmitter priority, see "Transmitter Priority" on page 435. When cells, transmitters or sites have the same priority, processing is based on an alphanumeric order.
5.7.1.2.3
Difference between Adjacent and Distributed PN-Clusters The following example explains the difference between "Adjacent PN-clusters" and "Distributed PN-clusters". The PILOT_INC has been set to 4 and the PN-cluster size to 3. There are: • •
128 PN offsets that can be allocated: they are all PN offsets from 4 to 508 with a separation interval of 4. Each PN-cluster consists of three PN offsets. So, there are 42 PN-clusters available.
If you select "Adjacent PN-cluster per site" as allocation strategy, Atoll will consider PN-clusters consisted of adjacent PN offsets (e.g. {4,8,12}, {16,20,24}, ...,{496,500,504}). If you select "Distributed PN-cluster per site" as allocation strategy, Atoll will consider PN-clusters consisted of PN offsets separated as much as possible (e.g. {4,172,340}, {8,176,344}, ...,{168,336,504}).
5.7.1.3 Priority Determination 5.7.1.3.1
Cell Priority PN offset allocation algorithm in Atoll allots priorities to cells before performing the actual allocation. Priorities assigned to cells depend upon how much constrained each cell is and the cost defined for each constraint. A cell without any constraint has a default cost, C , equal to 0. The higher the cost on a cell, the higher the priority it has for the PN offset allocation process. There are five criteria employed to determine the cell priority: PN Offset Domain Criterion The cost due to the domain constraint, C i Dom , depends on the number of PN offsets available for the allocation. The domain constraint is mandatory and cannot be broken. When no domain is assigned to cells, 512 PN offsets are available and we have: C i Dom = 0 When domains of PN offsets are assigned to cells, each unavailable PN offset generates a cost. The higher the number of codes available in the domain, the less will be the cost due to this criterion. The cost is given as: C i Dom = 512 – Number of PN Offsets in the domain
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Distance Criterion The constraint level of any cell i depends on the number of cells (j) present within a radius of "reuse distance" from its centre. The total cost due to the distance constraint is given as:
Cj Dist i
C i Dist =
j
Each cell j within the reuse distance generates a cost given as: C j Dist i = w d ij c dis tan ce Where w d ij is a weight depending on the distance between i and j. This weight is inversely proportional to the inter-cell distance. For a reuse distance of 2000m, the weight for an inter-cell distance of 1500m is 0.25, the weight for co-site cells is 1 and the weight for two cells spaced out 2100m apart is 0. c dis tan ce is the cost of the distance constraint. This value can be defined in the Constraint Cost dialogue. •
Exceptional Pair Criterion
The constraint level of any cell i depends on the number of exceptional pairs (j) for that cell. The total cost due to exceptional pair constraint is given as: C i EP =
cEP i – j j
Where c EP is the cost of the exceptional pair constraint. This value can be defined in the Constraint Cost dialogue. Neighbourhood Criterion The constraint level of any cell i depends on the number of its neighbour cells j, the number of second order neighbours k and the number of third order neighbours l. Let’s consider the following neighbour schema:
Figure 5.7: Neighbourhood Constraints The total cost due to the neighbour constraint is given as: Ci N =
Cj N1 i + Cj – j N1 i + Ck N2 i + Ck – k N2 i + Cl N3 i + Cl – l N3 i j
j
k
k
l
l
Each first order neighbour cell j generates a cost given as: C j N1 i = I j c N1 Where I j is the importance of the neighbour cell j. c N1 is the cost of the first order neighbour constraint. This value can be defined in the Constraint Cost dialogue. Because two first order neighbours must not have the same PN offset, Atoll considers the cost created by two first order neighbours to be each other. C j N1 i + C j N1 i C j – j N1 i = ----------------------------------------------------2 Each second order neighbour cell k generates a cost given as:
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C k N2 i = Max ( C j N1 i C k N1 j , C j N1 i C k N1 j ) c N2 Where c N2 is the cost of the second order neighbour constraint. This value can be defined in the Constraint Cost dialogue. Because two second order neighbours must not have the same PN offset, Atoll considers the cost created by two second order neighbours to be each other. C k N2 i + C k N2 i C k – k N2 i = ------------------------------------------------------2 Each third order neighbour cell l generates a cost given as: C N1 i C k N1 j C l N1 k C j N1 i C k N1 j C l N1 k C l N3 i = Max j c N3 C j N1 i C k N1 j C l N1 k C j N1 i C k N1 j C l N1 k Where c N3 is the cost of the third order neighbour constraint. This value can be defined in the Constraint Cost dialogue. Because two third order neighbours must not have the same PN offset, Atoll considers the cost created by two third order neighbours to be each other. C l N3 i + C l N3 i C l – l N3 i = ----------------------------------------------------2 Atoll considers the highest cost of both links when a neighbour relation is symmetric and the importance value is different. . In this case, we have: C j N1 i = Max I i – j I j – i c N1 And C k N2 i = Max (C j N1 i C k N1 j ,C j N1 k C i N1 j ) c N2 LTE Neighbour Criterion This criterion is considered in 3GPP2 multi-RAT documents. If the cell i is neighbour of an LTE cell, the cell constraint level depends on how many cells j are neighbours of the same LTE cell. The total cost due to LTE neighbour constraint is given as: C i N LTE =
cNLTE j – TxLTE j
Where cN
LTE
is the cost of the LTE neighbour constraint. This value can be defined in the Constraint Cost dialogue.
Therefore, the total cost due to constraints on any cell i is defined as: C i = C i Dom + C i U With C i U = C i Dist + C i EP + C i N + C i N 2G
5.7.1.3.2
Transmitter Priority In case you have a multi-carrier network and you run PN offset allocation on "all" the carriers with the option "allocate carriers identically", algorithm in Atoll allots priorities to transmitters. Priorities assigned to transmitters depend on how much constrained each transmitter is and the cost defined for each constraint. The higher the cost on a transmitter, the higher the priority it has for the PN offset allocation process. Let us consider a transmitter Tx with two cells using carriers 0 and 1. The cost due to constraints on the transmitter is given as: C Tx = C Tx Dom + C Tx U
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Max C U and C Dom = 512 – Number of PN offsets in the domain Tx i Tx i
With C Tx U =
Here, the domain available for the transmitter is the intersection of domains assigned to cells of the transmitter. The domain constraint is mandatory and cannot be broken.
5.7.1.3.3
Site Priority In case of "Per Site" allocation strategies (Adjacent PN-clusters per site and Distributed PN-clusters per site), algorithm in Atoll allots priorities to sites. Priorities assigned to sites depend on how much constrained each site is. The higher the constraint on a site, the higher the priority it has for the PN offset allocation process. Let us consider a site S with three transmitters; each of them has two cells using carriers 0 and 1. The site constraint is given as: C S = C S U + C S Dom With, C S U =
CTx U , and CS Dom
= 512 – Number of PN offsets in the domain
Tx
Here, the domain considered for the site is the intersection of domains available for transmitters of the site.
5.7.2 Allocation Examples In order to understand the differences between the different allocation strategies and the behaviour of the algorithm when using a maximum of PN offsets or not, let us consider the following sample scenario:
Figure 5.8: PN Offset Allocation Let Site0, Site1, Site2 and Site3 be four sites with 3 cells using carrier 0 whom PN offsets have to be allocated. The PILOT_INC parameter has been set to 4 and the PN Cluster Size is 3. Therefore, all PN offsets from 4 to 508 with a separation interval of 4 can be allocated. The reuse distance is supposed to be lower than the inter-site distance. Only co-site neighbours exist and all of them have the same importance. The following section lists the results of each combination of options with explanation where necessary.
5.7.2.1 Strategy: PN Offset per Cell Since the restrictions of neighbourhood only apply to co-sites with the same importance and inter-site distances are greater than reuse distances, every cell has the same priority. Then, the PN offset allocation to cells is performed in an alphanumeric order.
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Without ‘Use a Maximum of PN Offsets’
With ‘Use a Maximum of PN Offsets’
Atoll allocates the first three PN offsets in the domain (4, 8 and 12) to the Site0’s cells. Under given constraints of neighbourhood and reuse distance, same PN offsets can be allocated to each site’s cells.
Atoll allocates the first three PN offsets in the domain (4, 8 and 12) to the Site0’s cells. As it is allowed to use a maximum of PN offsets, Atoll allocates different PN offsets to each site’s cells so that there is least repetition.
5.7.2.2 Strategy: Adjacent PN-Clusters Per Site Since the restrictions of neighbourhood only apply to co-sites with the same importance and inter-site distances are greater than reuse distances, every cell has the same priority. Then, the PN offset allocation to cells is performed in an alphanumeric order. Without ‘Use a Maximum of PN Offsets’
With ‘Use a Maximum of PN Offsets’
Atoll allocates a PN cluster of adjacent PN offsets to Site0 and As it is possible to use a maximum of PN offsets, Atoll then, one PN offset of the PN cluster to each cell. Under given allocates different PN clusters of adjacent PN offsets to sites constraints of neighbourhood and reuse distance, the same so that there is least repetition of PN offsets. PN cluster can be allocated to each site and same PN offsets to each site’s cells.
5.7.2.3 Strategy: ‘Distributed PN-Clusters Per Site Since the restrictions of neighbourhood only apply to co-sites with the same importance and inter-site distances are greater than reuse distances, every cell has the same priority. Then, the PN offset allocation to cells is performed in an alphanumeric order.
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With ‘Use a Maximum of PN Offsets’
Atoll allocates a PN cluster of distributed PN offsets to Site0 As it is possible to use a maximum of PN offsets, Atoll and then, one PN offset of the PN cluster to each cell. Under allocates different PN clusters of distributed PN offsets to given constraints of neighbourhood and reuse distance, the sites so that there is least repetition of PN offsets. same PN cluster can be allocated to each site and same PN offsets to each site’s cells.
5.8 Automatic GSM-CDMA Neighbour Allocation 5.8.1 Overview You can automatically calculate and allocate neighbours between GSM/TDMA and CDMA2000 networks. In Atoll, it is called inter-technology neighbour allocation. Inter-technology handover is used in two cases: • •
When the CDMA coverage is not continuous. In this case, the CDMA coverage is extended by CDMA-GSM handover into the GSM network, And in order to balance traffic and service distribution between both networks.
Note that the automatic inter-technology neighbour allocation algorithm takes into account both cases. In order to be able to use the inter-technology neighbour allocation algorithm, you must have: • •
An .atl document containing the GSM/TDMA network, GSM.atl, and another one containing the CDMA2000 network, CDMA.atl, An existing link on the Transmitters folder of GSM.atl into CDMA.atl.
The external neighbour allocation algorithm takes into account all the GSM TBC transmitters. It means that all the TBC transmitters of GSM.atl are potential neighbours. The cells to be allocated will be called TBA cells which, being cells of CDMA.atl, fulfill following conditions: • • • •
They are active, They satisfy the filter criteria applied to Transmitters folder, They are located inside the focus zone, They belong to the folder for which allocation has been executed. This folder can be either the Transmitters folder or a group of transmitters subfolder.
Only CDMA TBA cells may be assigned neighbours.
5.8.2 Automatic Allocation Description The allocation algorithm takes into account criteria listed below: • • • •
The inter-transmitter distance, The maximum number of neighbours fixed, Allocation options, The selected allocation strategy,
Two allocation strategies are available: the first one is based on distance and the second one on coverage overlapping. We assume we have a CDMA reference cell, A, and a GSM candidate neighbour, transmitter B.
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5.8.2.1 Algorithm Based on Distance When the automatic allocation starts, Atoll checks the following conditions: •
The distance between the CDMA reference cell and the GSM neighbour must be less than the user-definable maximum inter-site distance. If the distance between the CDMA reference cell and the GSM neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance, which corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 430.
•
The calculation options,
Carriers: This option enables you to select the carrier(s) on which you want to run the allocation. You may choose one or more carriers. Atoll will allocate neighbours to cells using the selected carriers. Force co-site cells as neighbours: It enables you to automatically include GSM transmitters located on the same site as the reference CDMA cell in the candidate neighbour list. This option is automatically selected. Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may force/forbid a GSM transmitter to be candidate neighbour of the reference CDMA cell. Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, existing neighbours are kept. •
The importance of neighbours.
Importance values are used by the allocation algorithm to rank the neighbours. Atoll lists all neighbours and sorts them by importance value so as to eliminate some of them from the neighbour list if the maximum number of neighbours to be allocated to each cell is exceeded. If we consider the case for which there are 15 candidate neighbours and the maximum number of neighbours to be allocated to the reference cell is 8. Among these 15 candidate neighbours, only 8 (having the highest importance values) will be allocated to the reference cell. Note that the maximum number of inter-technology neighbours can be defined at the cell level (property dialogue or cell table). If defined there, this value is taken into account instead of the default one available in the Neighbour Allocation dialogue. As indicated in the table below, the neighbour importance depends on the distance and on the neighbourhood cause; this value varies between 0 to 100%. Neighbourhood cause
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter
If the Force co-site cells as neighbours option is selected
100 %
Neighbourhood relationship that fulfils distance conditions
If the maximum distance is not exceeded
d1 – ---------d max
Where d is the effective distance between the CDMA reference cell and the GSM neighbour and d max is the maximum intersite distance. In the Results part, Atoll provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason. Therefore, a neighbour may be marked as exceptional pair, co-site, or distance. For neighbours accepted for distance reasons, Atoll displays the distance from the reference cell (m). Finally, if cells have previous allocations in the list, neighbours are marked as existing.
5.8.2.2 Algorithm Based on Coverage Overlapping When automatic allocation starts, Atoll checks following conditions: •
The distance between the CDMA reference cell and the GSM neighbour must be less than the user-definable maximum inter-site distance. If the distance between the CDMA reference cell and the GSM neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance, which corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 430.
•
The calculation options,
Carriers: This option enables you to select the carrier(s) on which you want to run the allocation. You may choose one or more carriers. Atoll will allocate neighbours to cells using the selected carriers.
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Force co-site cells as neighbours: It enables you to automatically include GSM transmitters located on the same site as the reference CDMA cell in the candidate neighbour list. This option is automatically selected. Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may force/forbid a GSM transmitter to be candidate neighbour of the reference CDMA cell. Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, existing neighbours are kept. •
There must be an overlapping zone ( S A S B ) with a given cell edge coverage probability where:
Four different cases may be considered for SA: •
1st case: SA is the area where the cell A is the best serving cell of the CDMA network. • The pilot signal received from A is greater than the minimum pilot signal level, • The pilot quality from A exceeds a user-definable minimum value (minimum Ec/I0) and is the highest one. In this case, the Ec/I0 margin must be equal to 0dB and the max Ec/I0 option disabled.
•
2nd case: SA represents the area where the pilot quality from the cell A strats decreasing but the cell A is still the best serving cell of the CDMA network. The Ec/I0 margin must be equal to 0dB, the max Ec/I0 option selected and a maximum Ec/I0 user-defined. • • •
•
The pilot signal received from A is greater than the minimum pilot signal level, The pilot quality from A exceeds the minimum Ec/I0 but is lower than the maximum Ec/I0. The pilot quality from A is the highest one.
3rd case: SA represents the area where the cell A is not the best serving cell but can enter the active set. Here, the Ec/I0 margin has to be different from 0dB and the max Ec/I0 option disabled. • •
•
The pilot signal received from A is greater than the minimum pilot signal level, The pilot quality from A is within a margin from the best Ec/I0, where the best Ec/I0 exceeds the minimum Ec/ I0. 4th case: SA represents the area where: • The pilot signal received from A is greater than the minimum pilot signal level, • The pilot quality from A is within a margin from the best Ec/I0 (where the best Ec/I0 exceeds the minimum Ec/ I0) and lower than the maximum Ec/I0. In this case, the margin must be different from 0dB, the max Ec/I0 option selected and a maximum Ec/I0 userdefined.
Two different cases may be considered for SB: •
1st case: SB is the area where the cell B is the best serving cell of the GSM network. In this case, the margin must be set to 0dB. •
•
The signal level received from B on the BCCH TRX type exceeds the user-defined minimum threshold and is the highest one. 2nd case: The margin is different from 0dB and SB is the area where: • The signal level received from B on the BCCH TRX type exceeds the user-defined minimum threshold and is within a margin from the best BCCH signal level.
SA SB Atoll calculates the percentage of covered area ( ------------------ 100 ) and compares this value to the % minimum covered area. If SA this percentage is not exceeded, the candidate neighbour B is discarded. Candidate neighbours fulfilling coverage conditions are sorted in descending order with respect to percentage of covered area. When the automatic allocation is based on coverage overlapping, we recommend you to perform two successive automatic allocations: • •
•
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A first allocation in order to find handovers due to non-continuous CDMA coverage. In this case, you have to select the max Ec/I0 option and define a high enough value. A second allocation in order to complete the previous list with handovers motivated for reasons of traffic and service distribution. Here, the max Ec/I0 option must be disabled.
The importance of neighbours.
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Importance values are used by the allocation algorithm to rank the neighbours according to the distance and the allocation reason. Atoll lists all neighbours and sorts them by importance value so as to eliminate some of them from the neighbour list if the maximum number of neighbours to be allocated to each cell is exceeded. If we consider the case for which there are 15 candidate neighbours and the maximum number of neighbours to be allocated to the reference cell is 8. Among these 15 candidate neighbours, only 8 (having the highest importance values) will be allocated to the reference cell. Note that the maximum number of inter-technology neighbours can be defined at the cell level (property dialogue or cell table). If defined there, this value is taken into account instead of the default one available in the Neighbour Allocation dialogue. As indicated in the table below, the neighbour importance depends on the neighbourhood cause; this value varies between 0 to 100%. Neighbourhood reason
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter
If the Force co-site cells as neighbours option is selected
IF
Neighbourhood relationship that fulfils coverage conditions
If the % minimum covered area is exceeded
IF
Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined using the Importance Function (IF). The IF considers the following factors for calculating the importance: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Calculation of the Inter-Transmitter Distance" on page 430. d max is the maximum distance between the reference transmitter and a possible neighbour.
• •
The co-site factor (C): a Boolean, The overlapping factor (O): the percentage of overlapping.
The IF is user-definable using the Min importance and Max importance fields. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The IF evaluates importance as follows: Co-site Neighbourhood cause
IF
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%-Max(Di))(O)}
10%+50%{10%(Di)+90%(O)}
Yes
Min(C)+Delta(C){Max(Di)(Di)/(Max(Di)+Max(O))+ Max(O)(O)/(Max(Di)+Max(O))}
60%+40%{1/7%(Di)+6/7%(O)}
Where Delta(X)=Max(X)-Min(X) • •
•
Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes.
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In the Results part, Atoll provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason. Therefore, a neighbour may be marked as exceptional pair, co-site or coverage. For neighbours accepted for co-site and coverage reasons, Atoll displays the percentage of area meeting the coverage conditions and the corresponding surface area (km2). Finally, if cells have previous allocations in the list, neighbours are marked as existing. •
•
•
No prediction study is needed to perform an automatic neighbour allocation. When starting an automatic neighbour allocation, Atoll automatically calculates the path loss matrices if not found. A forbidden neighbour must not be listed as neighbour except if the neighbourhood relationship already exists and the Delete existing neighbours option is unchecked when you start the new allocation. In this case, Atoll displays a warning in the Event viewer indicating that the constraint on the forbidden neighbour will be ignored by algorithm because the neighbour already exists. In the Results, Atoll displays only the cells for which it finds new neighbours. Therefore, if a TBA cell has already reached its maximum number of neighbours before starting the new allocation, it will not appear in the Results table.
5.8.2.3 Delete Existing Neighbours Option As explained above, Atoll keeps the existing inter-technology neighbours when the Delete existing neighbours option is not checked. We assume that we have an existing allocation of inter-technology neighbours. A new TBA cell i is created in CDMA.atl. Therefore, if you start a new allocation without selecting the Delete existing neighbours option, Atoll determines the neighbour list of the cell i, If you change some allocation criteria (e.g. increase the maximum number of neighbours or create a new GSM TBC transmitter) and start a new allocation without selecting the Delete existing neighbours option, it examines the neighbour list of TBA cells and checks allocation criteria if there is space in their neighbour lists. A new GSM TBC transmitter can enter the TBA cell neighbour list if allocation criteria are satisfied. It will be the first one in the neighbour list.
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Chapter 6 LTE Networks This chapter covers the following topics: •
"Definitions" on page 445
•
"Calculation Quick Reference" on page 450
•
"Available Calculations" on page 470
•
"Calculation Details" on page 485
•
"Automatic Planning Algorithms" on page 563
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6 LTE Networks This chapter describes all the calculations performed in Atoll LTE documents. The first part of this chapter lists all the input parameters in the LTE documents, their significance, location in the Atoll GUI, and their usage. It also contains the lists of the formulas used for the calculations. The second part describes all the calculation processes, i.e., signal level coverage predictions, point analysis calculations, signal quality coverage predictions, calculations on subscriber lists, and Monte Carlo simulations. The calculation algorithms used by these calculation processes are available in the next part. The third part describes all the calculation algorithms used in all the calculations. These algorithms include the calculation of signal levels, noise, and interference for downlink and uplink considering power control, MIMO, smart antennas, and the radio resource management algorithms used by the different available schedulers. If you are new to LTE, you can also see the Glossary of LTE Terms in the User Manual for information on LTE terms and concepts, especially in the context of their user in Atoll. • • •
All the calculations are performed on TBC (to be calculated) transmitters. For the definition of TBC transmitters please refer to "Path Loss Matrices" on page 103. A cell refers to a transmitter-carrier (TX-c) pair. The cell being studied during a calculation is referred to as TXi(ic) in this chapter. All the calculation algorithms in this section are described for two types of cells: •
•
A studied cell (represented by the subscript "i") comprising the studied transmitter TXi and its carrier ic. It is the cell which is currently the focus of the calculation. For example, a victim cell when calculating the interference it is receiving from other cells. • Other cells (represented by the subscript "j") comprising the other transmitter TXj and its carrier jc. The other cells in the network can be interfering cells (downlink) or the serving cells of interfering mobiles (uplink). All the calculation algorithms in this section are described for two types of receivers:
•
Mi: A pixel (coverage predictions), subscriber (calculations on subscriber lists), or mobile (Monte Carlo simulations) covered/served by the studied cell TXi(ic). • Mj: A mobile (Monte Carlo simulations) covered/served by any other cell TXj(jc). Logarithms used in this chapter (Log function) are base-10 unless stated otherwise. •
6.1 Definitions This table lists the input to calculations, coverage predictions, and simulations. Name
Value
Unit
Description
D Frame
3GPP parameter (Fixed to 10 ms in Atoll)
ms
Frame duration
W FB
3GPP parameter (Fixed to 180 kHz in Atoll)
kHz
Width of a resource/frequency block
F
3GPP parameter (Fixed to 15 kHz in Atoll)
kHz
Subcarrier width
N FB – SS PBCH
3GPP parameter (Fixed to 6 in Atoll)
None
Number of frequency blocks for SS and PBCH transmission
N SF Frame
3GPP parameter (Fixed to 10 in Atoll)
None
Number of subframes per frame
N Slots SF
3GPP parameter (Fixed to 2 in Atoll)
None
Number of slots per subframe
K
1.38 x 10-23
J/K
Boltzmann’s constant
T
290
K
Ambient temperature
n0
Calculation result ( 10 Log K T 1000 = – 174 dBm/Hz )
dBm/Hz
Power spectral density of thermal noise
D CP
Frame configuration or, otherwise, global parameter
None
Cyclic prefix duration
N SD – PDCCH
Frame configuration or, otherwise, global parameter
SD
Number of PDCCH symbol durations per subframe
N FB – PUCCH
Frame configuration or, otherwise, global parameter
RB
Average number of PUCCH frequency blocks per frame
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Name
Value
Unit
Description
M PC
Global parameter
dB
Uplink power control adjustment margin
CNR Min
Global parametera
dB
Minimum signal to thermal noise threshold (interferer cutoff)
W Channel
Frequency band parameter
MHz
Channel bandwidth
First
Frequency band parameter
None
First channel number of the frequency band
N Channel
Last
Frequency band parameter
None
Last channel number of the frequency band
F Start – TDD
Frequency band parameter
MHz
Start frequency of the TDD frequency band
F Start – FDD – DL
Frequency band parameter
MHz
DL start frequency of the FDD frequency band
F Start – FDD – UL
Frequency band parameter
MHz
UL start frequency of the FDD frequency band
F Sampling
Frequency band parameter
MHz
Sampling frequency
f ACS
Frequency band parameter
dB
Adjacent channel suppression factor
N FB
Frequency band parameter
None
Number of frequency blocks per channel bandwidth
ICS Band
Frequency band parameter
MHz
Inter-channel spacing
CN Band
Frequency band parameter
None
Channel number step
N SCa – Total
F Sampling -) Calculation result ( N SCa – Total = -------------------F
None
Total number of subcarriers
N SCa – Used
N FB W FB -) Calculation result ( N SCa – Used = -----------------------F
None
Number of used subcarriers
N SCa – DC
Hard-coded parameter ( N SCa – DC = 1 )
None
Number of DC subcarriers
N SCa – Guard
Calculation result ( N SCa – Guard = N SCa – Total – N SCa – Used – N SCa – DC )
None
Number of guard subcarriers
i Layer
Layer parameter
None
Layer index
p Layer
Layer parameter
None
Layer priority
V Layer
Max
Layer parameter
km/h
Maximum mobile speed supported by a layer
CE
Frame configuration parameter
dB
Cell-edge power boost
N FB – CE0
Frame configuration parameter
None
Number of cell-edge frequency blocks for PSS ID 0
N FB – CE1
Frame configuration parameter
None
Number of cell-edge frequency blocks for PSS ID 1
N FB – CE2
Frame configuration parameter
None
Number of cell-edge frequency blocks for PSS ID 2
B
Bearer parameter
None
Bearer index
Mod B
Bearer parameter
None
Modulation used by the bearer
CR B
Bearer parameter
None
Coding rate of the bearer
B
Bearer parameter
bits/ symbol
Bearer efficiency
TB
Bearer parameter
dB
Bearer selection threshold
Site
Site parameter
kbps
Maximum S1 interface site downlink throughput
N Channel
TP S1 – DL
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Name
Value
Unit
Description
Site
Site parameter
kbps
Maximum S1 interface site uplink throughput
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
dB
Transmitter noise figure
N Ant – TX
Transmitter parameter
None
Number of antenna ports used for transmission
N Ant – RX
Transmitter parameter
None
Number of antenna ports used for reception
TX
Transmitter antenna parameter
dB
Antenna gain
TX
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
dB
Transmitter loss
TX
Smart antenna parameter
None
Number of smart antenna elements
Array
Smart antenna parameter
dB
Array gain offset
Combining
Smart antenna parameter
dB
Power combining gain offset
G SA
Smart antenna parameter
dB
Diversity gain (cross-polarisation)
N Channel
Cell parameter
None
Cell’s channel number
ID
Cell parameter
None
Cell’s physical ID
ID SSS
ID Cell parameter: Floor -------- 3
None
Cell’s SSS ID (one of 168 pseudorandom sequences)
ID PSS
Cell parameter: ID Mod 3
None
Cell’s PSS ID (one of 3 cyclic shifts of the sequence given by the SSS ID)
Shift
Cell parameter: ID Mod 6
None
Cell’s v shift (also known as the reference signal hopping index)
P Max
Cell parameter
dBm
Maximum cell transmission power
EPRE DLRS
Cell parameter
dBm
Energy per resource element for the downlink reference signals (User-defined or calculated)
EPRE SS
Cell parameter
dB
Energy per resource element offset for the SS with respect to the downlink reference signal EPRE
EPRE PBCH
Cell parameter
dB
Energy per resource element offset for the PBCH with respect to the downlink reference signal EPRE
EPRE PDCCH
Cell parameter
dB
Energy per resource element offset for the PDCCH with respect to the downlink reference signal EPRE
EPRE PDSCH
Cell parameter
dB
Energy per resource element offset for the PDSCH with respect to the downlink reference signal EPRE
T RSRP
Cell parameter
dB
Minimum Required RSRP
TX i ic
Cell parameter
dB
Cell selection threshold
TX ic i
Cell parameter
dB
Cell individual offset
Cell parameter
dB
Handover margin
TL DL
Cell parameter
%
Downlink traffic load
r DL – CE
Cell parameter
%
Downlink cell-edge traffic ratio
TP S1 – UL nf
G L
TX
E SA G SA G SA
Div
T Selection O Individual TX i ic
M HO
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Name
Value
Unit
Description
TL UL
Cell parameter
%
Uplink traffic load
TL DL – Max
Cell parameter
%
Maximum downlink traffic load
TL UL – Max
Cell parameter
%
Maximum uplink traffic load
NR UL
Cell parameter
dB
Uplink noise rise
NRUL – ICIC
Cell parameter
dB
ICIC uplink noise rise
NR UL – Max
Cell parameter
dB
Maximum uplink noise rise
N Users – Max
Cell parameter
None
Maximum number of users per cell
N Users – DL
Cell parameter
None
Number of users connected to the cell in downlink
N Users – UL
Cell parameter
None
Number of users connected to the cell in uplink
L Path
Cell parameter
dB
Delta path loss threshold
N SF – DL
Cell parameter
None
Number of downlink subframes per frame
N SF – UL
Cell parameter
None
Number of uplink subframes per frame
N TDD – SSF
TX i ic
Cell parameter
None
Number of TDD special subframes per frame
D Reuse
Cell parameter
m
Channel and physical cell ID reuse distance
G MU – MIMO – DL
Cell parameter
None
Average number of co-scheduled MU-MIMO users in downlink
G MU – MIMO – UL
Cell parameter
None
Average number of co-scheduled MU-MIMO users in uplink
FPC
Cell parameter
None
Fractional power control factor
CINR PUSCH – Max
Cell parameter
dB
Maximum PUSCH C/(I+N)
Inter – Tech
Cell parameter
dB
Inter-technology downlink noise rise
Inter – Tech
Cell parameter
dB
Inter-technology uplink noise rise
AU DL
Cell parameter
%
Downlink AAS usage ratio
TX i ic
Proportional Fair scheduler parameter
None
Downlink multi-user diversity gain (MUG)
TX i ic
Proportional Fair scheduler parameter
None
Uplink multi-user diversity gain (MUG)
CINR MUG
Proportional Fair scheduler parameter
dB
Maximum C/(I+N) above which no MUG gain is applied
T SU – MIMO – UL
Cell reception equipment parameter
dB
Uplink SU-MIMO threshold
T MU – MIMO – UL
Cell reception equipment parameter
dB
Uplink MU-MIMO threshold
G SU – MIMO – UL
Cell reception equipment parameter
None
Maximum uplink SU-MIMO gain
G Div – UL
Cell reception equipment parameter
dB
Receive, SU-MIMO, or MU-MIMO diversity gain
T SCell
UL
Cell reception equipment parameter
dB
Uplink secondary cell activation threshold
QCI
Service parameter
None
QoS class identifier (QCI) of the service
p QCI
Service parameter (automatically determined from the QCI)
None
Service’s QCI priority
NR DL
NR UL
G MUG – DL G MUG – UL Max
Max
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Name
Value
Unit
Description
p Service
Service parameter
None
User-defined service priority
B DL – Highest
Service parameter
None
Highest bearer used by a service in the downlink
B UL – Highest
Service parameter
None
Highest bearer used by a service in the uplink
B DL – Lowest
Service parameter
None
Lowest bearer used by a service in the downlink
B UL – Lowest
Service parameter
None
Lowest bearer used by a service in the uplink
f Act
UL
Service parameter
%
Uplink activity factor
f Act
DL
Service parameter
%
Downlink activity factor
TPD Min – UL
Service parameter
kbps
Minimum throughput demand in the uplink (Guaranteed Bit Rate, GBR)
TPD Min – DL
Service parameter
kbps
Minimum throughput demand in the downlink (Guaranteed Bit Rate, GBR)
TPD Max – UL
Service parameter
kbps
Maximum throughput demand in the uplink (Maximum Bit Rate, MBR)
TPD Max – DL
Service parameter
kbps
Maximum throughput demand in the downlink (Maximum Bit Rate, MBR)
UL
Service parameter
kbps
Average requested throughput in the uplink
TP Average
DL
Service parameter
kbps
Average requested throughput in the downlink
TP Offset
Service parameter
kbps
Throughput offset
f TP – Scaling
Service parameter
%
Scaling factor
L Body
Service parameter
dB
Body loss
N FB – UL
Min
Service parameter
None
Minimum number of frequency blocks
P Min
Terminal parameter
dBm
Minimum terminal power
P Max
Terminal parameter
dBm
Maximum terminal power
nf
Terminal parameter
dB
Terminal noise figure
G
Terminal parameter
dB
Terminal antenna gain
L
Terminal parameter
dB
Terminal loss
N Ant – TX
Terminal parameter
None
Number of antenna ports for transmission
N Ant – RX
Terminal parameter
None
Number of antenna ports for reception
Max – DL
Terminal parameter
None
Maximum number of downlink secondary cells
Max – UL
Terminal parameter
None
Maximum number of uplink secondary cells
N TBB TTI
Max – DL
UE category parameter
Bits
Maximum number of transport block bits per TTI (subframe) in downlink
Max – UL
UE category parameter
Bits
Maximum number of transport block bits per TTI (subframe) in uplink
UE category parameter
None
Highest modulation supported in uplink
UE category parameter
None
Maximum number of reception antenna ports supported in downlink
TP Average
N SCell N SCell
N TBB TTI
Max – UL
Mod UE
Max – DL
N Ant – UE
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Name
Value
Unit
Description
T SU – MIMO – DL
Terminal reception equipment parameter
dB
SU-MIMO threshold
G SU – MIMO – DL
Terminal reception equipment parameter
None
Maximum downlink SU-MIMO gain
T MU – MIMO – DL
Terminal reception equipment parameter
dB
Downlink MU-MIMO threshold
G Div – PBCH
Terminal reception equipment parameter
dB
PBCH diversity gain
G Div – PDCCH
Terminal reception equipment parameter
dB
PDCCH diversity gain
G Div – DL
Terminal reception equipment parameter
dB
Transmit, SU-MIMO, or MU-MIMO diversity gain
T SCell
DL
Terminal reception equipment parameter
dB
Downlink secondary cell activation threshold
DL
Terminal reception equipment parameter
dB
Downlink AAS threshold
UL
Clutter parameter
dB
Additional uplink diversity gain
G Div
DL
Clutter parameter
dB
Additional downlink diversity gain
f SU – MIMO
Clutter parameter
None
SU-MIMO gain factor
L Indoor
Clutter parameter
dB
Indoor loss
L Path
Propagation model result
dB
Path loss
Max
T AAS G Div
F ICPDL
Network parameter
None
Inter-technology downlink channel protection ratio for a frequency offset F between the interfered and interfering frequency channels
M Shadowing – Model
Monte Carlo simulations: Random result calculated from model standard deviation Coverage Predictions: Result calculated from cell edge coverage probability and model standard deviation
dB
Model shadowing margin
M Shadowing – C I
Coverage Predictions: Result calculated from cell edge coverage probability and C/I standard deviation
dB
C/I shadowing margin
Any interfering cell whose signal to thermal noise ratio is less than CNR Min will be discarded.
a.
6.2 Calculation Quick Reference The following tables list the formulas used in calculations.
6.2.1 Downlink Transmission Powers Calculation Name
Value
Unit
Description
N Sym SRB
N SCa – FB N SD Slot N Slot SF
None
Number of symbols per scheduler resource block
N Sym SSF
DwPTS
N SCa – FB N SD SSF
None
Number of DwPTS modulation symbols per scheduler resource block in the TDD special subframes
N SCa – FB
W FB ---------F
None
Number of subcarriers per frequency block
None
Total number of symbols in downlink
TX ic i
N Sym – DL
450
DwPTS
TX ic i
N FB
TX ic i
TX ic i
N Sym SRB N SF – DL + N FB
TX ic i
DwPTS
N TDD – SSF N Sym SSF
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
Name
Value
Unit
Description
None
Number of symbols reserved for downlink reference signals in one scheduler resource block
See "Downlink Transmission Power Calculation" on page 485
None
Number of symbols reserved for downlink reference signals in DwPTS of one TDD special subframe
TX i ic
None
Number of symbols reserved for downlink reference signals in one frame
None
Number of symbols for downlink reference signals in one scheduler resource block
None
Number of symbols for downlink reference signals in DwPTS of one TDD special subframe
TX i ic
None
Number of symbols for downlink reference signals in one frame
Where N Sym – PSS = 2 N FB – SS PBCH N SCa – FB = 144
None
Number of symbols for the PSS and the SSS
None
Number of symbols for the PBCH
None
Number of symbols for the PDCCH
8 16 24
TX ic i
N Res SRB
TX i ic
N Res DwPTS
TX i ic
N Sym – Res
TX i ic
N SF – DL N FB
N DLRS SRB
TX i ic
TX i ic
N Sym – DLRS
TX ic
i if N Ant – TX = 2 TX ic
i if N Ant – TX = 4 or 8
TX i ic
TX i ic
TX i ic
N Res SRB + N TDD – SSF N FB
8 8 6
TX i ic
N DLRS DwPTS
TX ic
i if N Ant – TX = 1
TX i ic
N Res DwPTS
TX ic
i if N Ant – TX = 1 TX ic
i if N Ant – TX = 2 TX ic
i if N Ant – TX = 4 or 8
See "Downlink Transmission Power Calculation" on page 485 TX i ic
TX i ic
N SF – DL N FB
TX i ic
TX i ic
TX i ic
N DLRS SRB + N TDD – SSF N FB
N DLRS DwPTS
N Sym – PSS + N Sym – SSS = 288 N Sym – SS
N Sym – SSS = 2 N FB – SS PBCH N SCa – FB = 144 TX i ic
Extended CP: 216 Normal CP: 240
N Sym – PBCH
TX ic
i if N SD – PDCCH = 0 : 0 TX ic
TX ic
i i if N SD – PDCCH = 1 AND N Ant – TX 2 :
TX ic i
N Sym – PDCCH
TX ic
TX ic
TX i ic
TX ic
TX ic
i N i SD – PDCCH N SCa – FB – 4 N FB
N SF – DL
i i + NSD – PDCCH N SCa – FB – 4 N FB Otherwise: TX ic
TX i ic
N TDD – SSF
TX ic
TX ic
i i N i N SCa – FB – 2 Min 4 N Ant – TX N FB SD – PDCCH TX ic
TX ic
TX ic
i i i + Min 2 N SD – PDCCH N SCa – FB – 2 Min 4 N Ant – TX N FB TX i ic
N Sym – PDSCH
TX i ic
TX i ic
TX i ic
TX i ic
TX i ic
N SF – DL
N Sym – DL – N Sym – Res – N Sym – SS – N Sym – PBCH – N Sym – PDCCH
TX i ic
N TDD – SSF None
Number of symbols for the PDSCH
451
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
Name
©Forsk 2015
Value
Unit
Description
TX ic
P i Max ------------------- TX ic TX ic i i DwPTS 10 10 Log 10 N SD Slot N Slot SF N SF – DL + N TDD – SSF N SD SSF – TX ic
TX ic i
EPRE DLRS
TX ic
i i EPRE SS EPRE PBCH TX ic --------------------------------------------------------------------i 10 10 dBm/Sym 10 L og N Sym – DLRS + N Sym – SS 10 + N Sym – PBCH 10
+ N Sym – PDCCH 10
TX i ic EPRE PDCCH -----------------------------------10
+ N Sym – PDSCH 10
TX i ic EPRE PDSCH ------------------------------------ 10
Energy per resource element for 1 modulation symbol (dBm/Sym) of the downlink reference signals With reference signal EPRE calculation method is set to Calculated (equal distribution of unused EPRE)
TX ic
P i Max ------------------- TX i ic TX i ic DwPTS 10 10 Log 10 N SD Slot N Slot SF N SF – DL + N TDD – SSF N SD SSF – TX ic
TX ic i
EPRE DLRS
TX ic
i i EPRE EPRE SS PBCH TX ic ------------------------------------------------------------------i 10 10 dBm/Sym + N Sym – PBCH 10 10 L og N Sym – Res + N Sym – SS 10
+ N Sym – PDCCH 10
TX i ic EPRE PDCCH -----------------------------------10
+ N Sym – PDSCH 10
TX i ic EPRE PDSCH ------------------------------------ 10
Energy per resource element for 1 modulation symbol (dBm/Sym) of the downlink reference signals With reference signal EPRE calculation method is set to Calculated (with boost) or Calculated (without boost)
EPRE SS
EPRE DLRS + EPRE SS
TX i ic
TX i ic
dBm/Sym
Energy per resource element for 1 modulation symbol (dBm/Sym) of the SS
TX ic i EPRE PBCH
TX ic i EPRE DLRS
TX ic i EPRE PBCH
dBm/Sym
Energy per resource element for 1 modulation symbol (dBm/Sym) of the PBCH
TX i ic
TX i ic
TX i ic
dBm/Sym
Energy per resource element for 1 modulation symbol (dBm/Sym) of the PDCCH
TX i ic
TX i ic
dBm/Sym
Energy per resource element for 1 modulation symbol (dBm/Sym) of the PDSCH
dbm/Sym
"Boosted" energy per resource element for 1 modulation symbol (dBm/Sym) of downlink reference signals when the reference signal EPRE calculation method is set to Calculated (with boost)
dBm
Instantaneous transmission power of the downlink reference signals
+ 10 Log N SCa – FB N FB – SS PBCH
dBm
Instantaneous transmission power of the SS
EPRE PBCH + 10 Log N SCa – FB N FB – SS PBCH
dBm
Instantaneous transmission power of the PBCH
TX i ic
EPRE DLRS + EPRE PDCCH
EPRE PDCCH TX i ic
EPRE DLRS + EPRE PDSCH
EPRE PDSCH
TX ic i
EPRE DLRS
TX i ic
P DLRS
TX i ic
P SS
TX ic i
P PBCH
452
+
TX i ic
N TX i ic Sym – Res EPRE DLRS + 10 Log ------------------------ TXi ic N Sym – DLRS TX ic
TX ic
i i EPRE DLRS + 10 Log 2 N FB TX i ic
EPRE SS
TX ic i
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
Name
TX ic i P PDCCH
TX i ic
P PDSCH
Value
Unit
TX ic i TX ic N Sym–PDCCH i -dBm EPRE PDCCH + 10 Log ------------------------------------------------------------------------------------------------------------------------------------- TX ic TX ic TX ic TXi ic i i i N SD – PDCCH N SF – DL + Min 2 N SD – PDCCH N TDD – SSF
TX i ic TX ic N i Sym–PDSCH - EPRE PDSCH + 10 Log ------------------------------------------------------------------------------------------------------------------ TX i ic TX ic N i N N – N SD Slot Slot SF SD – PDCCH SF – DL TX i ic TX i ic DwPTS + – Min 2 N N N SD SSF SD – PDCCH TDD – SSF
dBm
Description
Average transmission power of the PDCCH
Average transmission power of the PDSCH
6.2.2 Co- and Adjacent Channel Overlaps Calculation Name TX i ic
F Start
Value
Unit
Description
N TXi ic – N First – TXi ic TX i ic TX i ic Channel Channel - F Start – Band + W Channel + ICS Band ------------------------------------------------------TX i ic CN Band
MHz
Start frequency for the channel number assigned to a cell
MHz
End frequency for the channel number assigned to a cell
MHz
Co-channel overlap bandwidth
None
Co-channel overlap ratio
MHz
Bandwidth of the lower-frequency adjacent channel overlap
None
Lower-frequency adjacent channel overlap ratio
MHz
Bandwidth of the higher-frequency adjacent channel overlap
None
Higher-frequency adjacent channel overlap ratio
None
Adjacent channel overlap ratio
None
Total overlap ratio
TX i ic
TX i ic
TX i ic
TX ic – TX jc i j
W CCO
TX jc
TX ic
TX i ic – TX j jc L
TX ic – TX jc i j H
TX i ic – TX j jc
TX jc
TX ic
TX jc
TX i ic – TX j jc
TX j jc
TX i ic
Min F End F End
TX ic
TX jc
TX ic
i j i + W Channel – Max F Start F End TX i ic – TX j jc
W ACO H ---------------------------------TX j jc W Channel TX ic – TX jc i j
TX i ic – TX j jc
r ACO
r ACO
rO
TX ic
W ACO L ---------------------------------TX j jc W Channel
H
TX i ic – TX j jc
TX ic
j i j i i Min F End F Start – Max F Start F Start – W Channel
TX i ic – TX j jc
r ACO
TX ic
W CCO ----------------------------------TX j jc W Channel
TX ic – TX jc i j r ACO L
W ACO
TX jc
j i j i Min F End F End – Max F Start F Start
TX ic – TX jc i j r CCO
W ACO
TX i ic
F Start + W Channel
F End
L
TX i ic – TX j jc
r CCO
TX ic – TX jc i j
+ r ACO
H
TX i ic – TX j jc
+ r ACO
10
TX i ic – f ACS ----------------------10
6.2.3 Signal Level Calculation (DL) The received signal levels (dBm) from any cell TXi(ic) are calculated for a pixel, subscriber, or mobile Mi as follows:
453
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©Forsk 2015
Name TX ic i C Max
Value TX ic i
EIRP Max – L Path – M Shadowing – Model – L Indoor + G –L
M
i
M
M
i
TX i ic
TX i
TX i
TX i
TX i
+ 10 Log E SA +
Combining G SA
TX i ic
–L
Mi
TX i ic
C SS
TX i
+
TX i ic
EIRP1 SS Mi
TX
i G Ant
–L
TX
i
TX
i
+ 10 Log E SA +
Mi
TX i ic
C PBCH
TX i
+ G Ant – L
TX i
+ G Ant – L
TX i
TX i
+ 10 Log E SA +
Combining G SA
TX i ic Mi
TX i ic
TX i
TX i
TX i
TX i
+ 10 Log E SA +
Combining G SA
TX ic i
–L
Mi
TX ic i
TX i
TX i
TX i
TX i
+ 10 Log E SA +
TX i ic
Mi
Mi
454
PDCCH EIRP
dBm
Received PDSCH signal level
dBm
PDSCH EIRP
dBm/Sym
Received downlink reference signal energy per resource element (RSRP)
Mi
Mi
TX i
Array
P PDSCH + G SA + G SA
E DLRS
dBm Div G SA
TX i
TX i
With smart antennas: TX i ic
TX i ic
Received PDCCH signal level
– L Ant – L Body + f CP TX i ic
TX i ic
+
EIRP1 PDSCH – L Path – M Shadowing – Model – L Indoor + G –L
dBm
i
TX i
Combining G SA
Without smart antennas: P PDSCH + G Ant – L EIRP1 PDSCH
M
With smart antennas: TX i ic
P PDCCH + G Ant – L
C PDSCH
PBCH EIRP
– L Ant – L Body + f CP TX i ic
TX i ic
dBm Div G SA
Mi
Without smart antennas: P PDCCH + G Ant – L EIRP1 PDCCH
+
EIRP1 PDCCH – L Path – M Shadowing – Model – L Indoor + G Mi
Received PBCH signal level
TX i
With smart antennas: TX i ic
P PBCH + G Ant – L
C PDCCH
dBm
Mi
Mi
TX i ic
TX i ic
SS EIRP
– L Ant – L Body + f CP
Without smart antennas: P PBCH + G Ant – L EIRP1 PBCH
dBm Div G SA
+
EIRP1 PBCH – L Path – M Shadowing – Model – L Indoor + G Mi
Received SS signal level
TX i
With smart antennas:
–L
dBm
Mi
Mi
TX i ic
P SS
RS EIRP
– L Ant – L Body + f CP TX i ic
TX i ic
dBm Combining G SA
– L Path – M Shadowing – Model – L Indoor + G
Without smart antennas: P SS EIRP1 SS
Received downlink reference signal level
TX i
With smart antennas: TX ic i P DLRS
–L
dBm
– L Ant – L Body + f CP TX i ic
TX i ic
Downlink max EIRP
Mi
Mi
Without smart antennas: P DLRS + G Ant – L EIRP1 DLRS
dbm Div G SA
+
EIRP1 DLRS – L Path – M Shadowing – Model – L Indoor + G Mi
Received max cell power
TX i
With smart antennas: TX i ic
P Max + G Ant – L
C DLRS
dBm
i
i
TX i ic
TX i ic
Description
– L Ant – L Body + f CP
Without smart antennas: P Max + G Ant – L EIRP Max
M
Unit
Combining
+ G SA
Div
+ G SA – L
TX i
TX i ic
EIRP2 DLRS – L Path – M Shadowing – Model – L Indoor + G
Mi
–L
Mi
Mi
Mi
– L Ant – L Body + f CP
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
Name
Value TX ic i
TX
i
Without smart antennas: EPRE DLRS + G Ant – L TX ic i
EIRP2 DLRS
TX ic i EPRE DLRS
TX
i
+ G Ant – L TX i ic
EIRP2 SS
E SS
TX
i
TX
– L Indoor + G
i
–L
Mi
Mi
EPRE SS TX i ic
E PBCH
TX i
+ G Ant – L
+ G Ant – L
TX i
– L Indoor + G
Mi
–L
Mi
Mi
Mi
TX i
TX i ic
TX i
TX i
TX i
+ 10 Log E SA + G SA
Combining
– L Indoor + G
Mi
–L
Mi
Mi
Mi
TX i ic
TX i
TX i
TX i
PDCCH EIRP
dBm/Sym
Received PDSCH energy per resource element
dBm/Sym
PDSCH EIRP
dB
Path loss
dB
Total losses
dB
Cyclic prefix factor, i.e., the ratio of the useful symbol energy to the total symbol energy
Combining Div + 10 Log E SA + G SA + G SA
TX ic i
EIRP2 PDSCH – L Path – M Shadowing – Model – L Indoor + G
Mi
–L
Mi
Mi
Mi
– L Ant – L Body + f CP TX
i
Without smart antennas: EPRE PDSCH + G Ant – L
TX
i
With smart antennas: TX i ic
TX i
Array
EPRE PDSCH + G SA + G SA
Combining
+ G SA
Div
+ G SA – L
TX i
L Path
L Model + L Ant L Path + L +L
Mi
TX i
–G
+ L Indoor + M Shadowing – Model – G
Mi
Mi
TX i
Mi
TX i ic TX i ic
10 Log 6 7.5 If D CP 0
TX i
+ L Ant + L Body
10 Log 7 7.5 If D CP f CP
dBm/Sym
TX i
TX i
TX ic i
L Total
Received PDCCH energy per resource element
– L Ant – L Body + f CP
With smart antennas: EPRE PDCCH + G Ant – L
EIRP2 PDSCH
dBm/Sym
Div
TX i ic
TX i ic
TX i ic
PBCH EIRP
+ G SA
EIRP2 PDCCH – L Path – M Shadowing – Model
TX i ic
E PDSCH
dBm/Sym
TX i
Without smart antennas: EPRE PDCCH + G Ant – L
TX i ic
Received PBCH energy per resource element
– L Ant – L Body + f CP
With smart antennas: EPRE PBCH + G Ant – L
EIRP2 PDCCH
dBm/Sym
TX ic i
EIRP2 PBCH – L Path – M Shadowing – Model
TX ic i
E PDCCH
SS EIRP
Combining Div + 10 Log E SA + G SA + G SA
TX i ic
TX i ic
dBm/Sym
TX i
Without smart antennas: EPRE PBCH + G Ant – L EIRP2 PBCH
Received SS energy per resource element
TX i
With smart antennas: TX i
dBm/Sym
– L Ant – L Body + f CP TX i ic
TX i ic
RS EIRP
Combining
Mi
Without smart antennas: EPRE SS TX i ic
dBm/Sym
+ 10 Log E SA + G SA
– L Path – M Shadowing – Model Mi
Description
i
With smart antennas:
TX i ic
EIRP2 SS
TX
Unit
If
= Normal = Extended
TX i ic is an interferer
6.2.4 Noise Calculation (DL) Name
Value
Unit
Description
TX i ic
n 0 + 10 Log F
dBm
Thermal noise for one resource element
n 0 – Sym
455
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
Name
©Forsk 2015
Value
TX ic i
TX ic i
n 0 – Sym + nf
n Sym
M
i
Unit
Description
dBm
Downlink noise for one resource element
6.2.5 Interference Calculation (DL) Name
Value
Unit
Description
dBm/Sym
Interfering energy per resource element (dBm/Sym) received over downlink reference signals (Method 1: synchronised transmission and reception) Case: RS of the interfered cell collide only with RS of the interfering cell
j TX jc E DLRS N j N TXi ic – N TX j jc --------------------- TX i ic – TX j jc 10 Ant – TX Ant – TX Ant – TX 10 Log ------------------ 10 + fO + 10 Log -------------------------------------------- TX i ic TXi ic N Ant – TX N Ant – TX dBm/Sym TX j jc TX i ic – TX j jc TX j jc TX i ic – TX j jc E PDCCH + f PDCCH E PDSCH + f PDSCH --------------------------------------------------------------------------------------------------------------------------------------------- 10 10 + 3 10 10 ----------------------------------------------------------------------------------------------------------------------------------- 4
Interfering energy per resource element (dBm/Sym) received over downlink reference signals (Method 1: synchronised transmission and reception) Case: RS of the interfered cell collide with RS, PDCCH, and PDSCH of the interfering cell With 1 or 2 antenna ports
TX jc
j TX ic E DLRS N i --------------------- TX ic – TX j jc 10 Ant – TX +f i 10 Log ------------------ 10 O TXj jc N Ant – TX
TX jc j
DLRS
TX jc
TX j jc
DLRS
TX jc
TX jc j
DLRS
j TX jc E DLRS N TXi ic – N TX j jc N j --------------------- TX i ic – TX j jc 10 Ant – TX Ant – TX Ant – TX + 10 Log -------------------------------------------- 10 Log ------------------ 10 TX i ic TX i ic + fO N Ant – TX N Ant – TX dBm/Sym TX j jc TX j jc TX ic – TX jc TX i ic – TX j jc i j E E +f +f PDCCH PDCCH PDSCH PDSCH --------------------------------------------------------------------------------------------------------------------------------------------- 10 10 10 + 5 10 ----------------------------------------------------------------------------------------------------------------------------------- 6 TX jc
TX j jc
DLRS
j TX jc E DLRS N j N TXi ic – N TX j jc --------------------- TX i ic – TX j jc 10 Ant – TX Ant – TX Ant – TX +f 10 Log ------------------ 10 + 10 Log --------------------------------------------O TX i ic TXi ic N Ant – TX N Ant – TX dBm/Sym TX j jc TX i ic – TX j jc TX j jc TX i ic – TX j jc E PDCCH + f PDCCH E PDSCH + f PDSCH --------------------------------------------------------------------------------------------------------------------------------------------- 10 10 + 2 10 10 ------------------------------------------------------------------------------------------------------------------------------------ 3 TX jc
TX jc j
DLRS
TX i ic – TX j jc
+ fO
456
TX ic – TX jc
TX jc
TX ic – TX jc
j i j j i j EPDCCH + f PDCCH E PDSCH + f PDSCH ----------------------------------------------------------------------- ----------------------------------------------------------------------10 10 10 + 3 10 10 Log ------------------------------------------------------------------------------------------------------------------------------------ 4
Interfering energy per resource element (dBm/Sym) received over downlink reference signals (Method 1: synchronised transmission and reception) Case: RS of the interfered cell collide with RS, PDCCH, and PDSCH of the interfering cell With 4 or 8 antenna ports and TX ic i
N SD – PDCCH = 1 Interfering energy per resource element (dBm/Sym) received over downlink reference signals (Method 1: synchronised transmission and reception) Case: RS of the interfered cell collide with RS, PDCCH, and PDSCH of the interfering cell With 4 or 8 antenna ports and TX i ic
N SD – PDCCH 1
Interfering energy per resource element (dBm/Sym) received over downlink reference signals (Method 1: synchronised dBm/Sym transmission and reception) Case: RS of the interfered cell collide with PDCCH and PDSCH of the interfering cell With 1 or 2 antenna ports
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
Name
Value
Unit
TX jc TX ic – TX jc j i j E +f PDCCH PDCCH ----------------------------------------------------------------------10
TX j jc
DLRS
TX jc TX ic – TX jc j i j E +f PDSCH PDSCH ----------------------------------------------------------------------- 10
10 + 5 10 10 Log ------------------------------------------------------------------------------------------------------------------------------------ 6 TX i ic – TX j jc
Interfering energy per resource element (dBm/Sym) received over downlink reference signals (Method 1: synchronised transmission and reception) Case: RS of the interfered cell dBm/Sym collide with PDCCH and PDSCH of the interfering cell With 4 or 8 antenna ports and
+ fO
TX i ic
N SD – PDCCH = 1 TX j jc
TX j jc
DLRS
TX i ic – TX j jc
TX j jc
TX i ic – TX j jc
EPDCCH + fPDCCH E PDSCH + f PDSCH ----------------------------------------------------------------------- ----------------------------------------------------------------------10 10 10 + 2 10 10 Log ------------------------------------------------------------------------------------------------------------------------------------ 3 TX i ic – TX j jc
Interfering energy per resource element (dBm/Sym) received over downlink reference signals (Method 1: synchronised transmission and reception) Case: RS of the interfered cell dBm/Sym collide with PDCCH and PDSCH of the interfering cell With 4 or 8 antenna ports and
+ fO
TX i ic
N SD – PDCCH 1 TX j jc
TX j jc
SS PBCH
Description
TX j jc
E PBCH ESS --------------------TX j jc ------------------- 10 10 10 N Sym – SS + 10 N Sym – PBCH - 10 Log ------------------------------------------------------------------------------------------------------------TX j jc N + N Sym – SS Sym – PBCH TX i ic – TX j jc
+ fO
dBm/Sym
TX j jc
Interfering energy per resource element (dBm/Sym) received over the SS and the PBCH (Method 1: synchronised transmission and reception)
+ f MIMO
TX jc
TX j jc
PDCCH
j E DLRS TX jc j -------------------- TX ic – TX j jc N Sym – DLRS in PDCCH 1 - 10 10 + f O i 10 Log ------------------ ----------------------------------------TX jc TX ic j i N Sym – PDCCH N Ant – TX TX jc
TX ic – TX jc
j i j TX ic E +f TX jc PDCCH PDCCH j N i ----------------------------------------------------------------------- – N 10 Sym – PDCCH Sym – DLRS in PDCCH - 10 + 10 L og ----------------------------------------------------------------------------TX ic i N Sym – PDCCH
Interfering energy per resource element (dBm/Sym) received over the PDCCH (Method 1: synchronised dBm/Sym transmission and reception) Case: PDCCH of the interfered cell collides with PDCCH and all the RS of the interfering cell
TX jc
TX j jc
PDCCH
TX j jc
PDCCH
j TX ic E DLRS TX jc TX ic j i N i --------------------- N – N Ant – TX Sym – DLRS in PDCCH Sym – DLRS in PDCCH - 10 10 10 Log ------------------ -----------------------------------------------------------------------------------------TX ic TXj jc i N Sym – PDCCH N Ant – TX TX jc
TX ic – TX jc
j i j TX jc E +f PDCCH PDCCH N j ----------------------------------------------------------------------TX ic – TX j jc 10 Sym – PDCCH +f i + 10 L og ---------------------------- 10 O TX ic i N Sym – PDCCH
TX j jc
TX i ic – TX j jc
E PDCCH + f PDCCH
TX i ic – TX j jc
+ fO
Interfering energy per resource element (dBm/Sym) received over the PDCCH (Method 1: synchronised dBm/Sym transmission and reception) Case: PDCCH of the interfered cell collides with PDCCH and some RS of the interfering cell Interfering energy per resource element (dBm/Sym) received over the PDCCH (Method 1: synchronised dBm/Sym transmission and reception) Case: PDCCH of the interfered cell collides only with PDCCH of the interfering cell
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Name
©Forsk 2015
Value
Unit
Description
TX jc
TX j jc
PDSCH
j E TX jc DLRS j -------------------TX ic – TX jc N 1 j 10 Sym – DLRS in PDSCH +f i - 10 ----------------------------------------10 Log ------------------O TX jc TX ic j i N Ant – TX N Sym – PDSCH TX jc
TX ic – TX jc
j i j TX ic E PDSCH + f PDSCH TX jc j N i ----------------------------------------------------------------------- – N 10 Sym – PDSCH Sym – DLRS in PDSCH 10 + 10 L og ----------------------------------------------------------------------------TX ic i N Sym – PDSCH
Interfering energy per resource element (dBm/Sym) received over the PDSCH (Method 1: synchronised dBm/Sym transmission and reception) Case: PDSCH of the interfered cell collides with PDSCH and all the RS of the interfering cell
TX jc
TX j jc
PDSCH
j TX ic E DLRS TX jc TX ic j i N i --------------------- N – N Ant – TX Sym – DLRS in PDSCH Sym – DLRS in PDSCH - 10 10 10 Log ------------------ ----------------------------------------------------------------------------------------TX ic TXj jc i N Sym – PDSCH N Ant – TX TX jc
TX j jc
TX j jc
PDSCH
TX i ic – TX j jc
E PDSCH + f PDSCH
TX jc
TX jc j
DLRS
TX jc j
TX jc
TX jc j
458
Interfering energy per resource element (dBm/Sym) received over the PDSCH (Method 1: synchronised dBm/Sym transmission and reception) Case: PDSCH of the interfered cell collides only with PDSCH of the interfering cell
TX ic – TX jc
dBm/Sym
Interfering energy per resource element (dBm/Sym) received over downlink reference signals (Method 2: non-synchronised transmission and reception)
+f E PBCH + f MIMO ESS MIMO----------------------------------------------TX jc --------------------------------------------- 10 10 j TX i ic – TX j jc 10 N Sym – SS + 10 N Sym – PBCH --------------------------------------------------------------------------------------------------------------------------------------------------10 Log + fO TX j jc N Sym – SS + N Sym – PBCH dBm/Sym
Interfering energy per resource element (dBm/Sym) received over the SS and the PBCH (Method 2: non-synchronised transmission and reception)
TX j jc
TX i ic – TX j jc
E PDSCH + f PDSCH TX j jc ----------------------------------------------------------------------TX ic – TX j jc N 10 Sym – PDSCH - + fO i ---------------------------+ 10 TX j jc N Sym – DL TX jc j
TX jc
PDCCH
TX i ic – TX j jc
+ fO
j i j E j E PDCCH + f PDCCH TX j jc TX j jc DLRS -----------------------------------------------------------------------------------------N N Sym – PDCCH 10 10 Sym – DLRS - + 10 ------------------------ ----------------------------10 Log 10 TX j jc TX j jc N Sym – DL N Sym – DL
TX jc j
SS PBCH
TX ic – TX jc
j i j TX jc E +f PDSCH PDSCH N j ----------------------------------------------------------------------- TX ic – TX j jc 10 Sym – PDSCH +f i - 10 + 10 L og ---------------------------O TX ic i N Sym – PDSCH
Interfering energy per resource element (dBm/Sym) received over the PDSCH (Method 1: synchronised dBm/Sym transmission and reception) Case: PDSCH of the interfered cell collides with PDSCH and some RS of the interfering cell
TX jc j
TX jc
TX jc j
TX ic – TX jc
j i j E j E PDCCH + f PDCCH TX j jc TX j jc DLRS -----------------------------------------------------------------------------------------N Sym – DLRS N Sym – PDCCH 10 10 -------------------------- + 10 ----------------------------10 Log 10 TX j jc TX j jc N Sym – DL N Sym – DL TX j jc
TX i ic – TX j jc
E PDSCH + f PDSCH TX j jc ----------------------------------------------------------------------TX ic – TX j jc N 10 Sym – PDSCH - + fO i ---------------------------+ 10 TX j jc N Sym – DL
dBm/Sym
Interfering energy per resource element (dBm/Sym) received over the PDCCH (Method 2: non-synchronised transmission and reception)
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
Name
Value TX jc
TX j jc
PDSCH
TX j jc
TX j jc
TX i ic – TX j jc
f PDCCH
TX i ic – TX j jc
TX i ic – TX j jc
TX i ic – TX j jc
dBm/Sym
Interfering energy per resource element (dBm/Sym) received over the PDSCH (Method 2: non-synchronised transmission and reception)
E PDSCH + f PDSCH TX jc ----------------------------------------------------------------------- N j TX ic – TX j jc 10 Sym – PDSCH - + fO i + 10 ---------------------------TX jc j N Sym – DL TX i ic – TX j jc
EPDSCH + fPDSCH TX j jc ---------------------------------------------------------------------10 N Sym – PDSCH 10 10 10 Log --------------------------------------------------------------------------------------------TX j jc TX j jc N + N Sym – PDSCH Sym – PDCCH
Interfering energy per frequency block (dBm/RB) received over 1 frequency block during an OFDM symbol carrying reference signals
dBm/RB E DLRS TX j jc For number of antenna ports > 1, -------------------TX j jc TX i ic – TX j jc N Sym – PDCCH 10 10 - 10 + 10 + -------------------------------------------------------------------------------------------- 2 Min 2 N Ant – TX + f O 8 is used instead of encircled 10 TX j jc TX j jc N Sym – PDSCH + N Sym – PDCCH TX j jc TX i ic – TX j jc E PDCCH + f PDCCH ----------------------------------------------------------------------10
TX j jc
TX jc TX jc TX ic – TX jc TX ic – TX jc j j i j i j f MIMO + f TL + f ICIC – DL + f ABS – DL ------------------------------------------------------------------------------------------------------------------------------------------------- TX jc 10 1 – AU j 10 DL TX j jc TX i ic – TX j jc TX i ic – TX j jc f + f + f TL ICIC – DL ABS – DL -----------------------------------------------------------------------------------------------------------------------TX jc j 10 + 10 AU DL TX jc
f PDSCH
Description
TX ic – TX jc
j i j E j E +f TX jc TX jc DLRS PDCCH PDCCH j j -----------------------------------------------------------------------------------------N Sym – DLRS N Sym – PDCCH 10 10 - + 10 ---------------------------- ------------------------ 10 Log 10 TX jc TX jc j j N Sym – DL N Sym – DL
TX j jc
RSSI
TX jc
Unit
TX jc
TX ic – TX jc
TX i ic – TX j jc
10 Log r O
TX ic – TX jc i j f ICIC – DL
10 Log p Collision
PDCCH interference weighting factor
dB
PDSCH interference weighting factor
dB
Interference reduction factor due to channel overlap
dB
Interference reduction factor due to static downlink ICIC using fractional frequency reuse
TX ic – TX jc
j j i j i j f MIMO + f TL + f ICIC – DL + f ABS – DL ------------------------------------------------------------------------------------------------------------------------------------------------- TX j jc 10 1 – AU DL 10 TX TX TX ic – TX jc TX ic – TX jc j j i j i j G SA – G SA + f ICIC – DL + f ABS – DL ------------------------------------------------------------------------------------------------------------------------------------------------------- TX jc 10 + AU DLj 10
fO
dB
TX i ic – TX j jc
TX jc
TX j jc
j 10 Log TLDL
dB
Interference reduction factor due to the downlink traffic load
f MIMO
TX j jc
j 10 Log N Ant – TX
dB
Interference increment due to more than one transmission antenna port
Inter – Tech I DL
TX k P DL – Rec -------------------------------------- F TX i ic TX k TX k ICP DL
W
Downlink inter-technology interference
f TL
TX jc
6.2.6 C/N Calculation (DL) Name TX i ic
CNR DLRS
Value TX i ic
TX i ic
E DLRS – n Sym
Unit
Description
dB
Downlink reference signals C/N
459
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
©Forsk 2015
Name
Value
TX ic i
TX ic i
CNR SS
TX ic i CNR PBCH
E SS
TX ic i
TX ic i CNR PDSCH
Description
dB
SS C/N
dB
PBCH C/N
dB
PDCCH C/N
dB
PDSCH C/N
Unit
Description
TX ic i
E PBCH – n Sym TX i ic
TX i ic
Mi
DL
With MIMO: CNR PBCH = CNR PBCH + G Div – PBCH + G Div TX i ic
TX i ic
E PDCCH – n Sym
TX i ic
CNR PDCCH
TX ic i
– n Sym
Unit
TX i ic
TX i ic
Mi
DL
With MIMO: CNR PDCCH = CNR PDCCH + G Div – PDCCH + G Div TX i ic
TX i ic
E PDSCH – n Sym TX i ic
TX i ic
Mi
DL
With MIMO: CNR PDSCH = CNR PDSCH + G Div – DL + G Div
6.2.7 C/(I+N) Calculation (DL) Name
Value TX jc
TX i ic
CINR DLRS
TX ic
i j n Sym DLRS ------------------ --------------------- TX i ic 10 10 + I Inter – Tech + 10 10 + NR Inter – Tech dB E DLRS – 10 Log DL DL All TXj jc
TX jc
TX ic i
CINR SS
TX ic
i j n Sym SS PBCH ------------------------ --------------------- TX i ic Inter – Tech Inter – Tech 10 10 10 +I + NR dB E SS + 10 – 10 Log DL DL All TXj jc
TX jc
TX i ic
CINR PBCH
Downlink reference signals C/(I+N)
SS C/(I+N)
TX ic
i j n Sym SS PBCH ------------------------ --------------------- TX i ic Inter – Tech Inter – Tech 10 10 10 +I + NR E PBCH – 10 Log + 10 DL DL dB All TXj jc
TX ic i
TX ic i
M
PBCH C/(I+N)
DL
i
With MIMO: CINR PBCH = CINR PBCH + G Div – PBCH + G Div TX jc
TX i ic
CINR PDCCH
TX ic
i j n Sym PDCCH- ------------------- --------------------- TX i ic Inter – Tech Inter – Tech 10 10 10 +I + NR E PDCCH – 10 Log + 10 DL DL dB All TXj jc
TX i ic
TX i ic
Mi
PDCCH C/(I+N)
DL
With MIMO: CINR PDCCH = CINR PDCCH + G Div – PDCCH + G Div TX jc
TX i ic
CINR PDSCH
TX ic
i j n Sym PDSCH- ---------------------------------------- TX i ic 10 10 + I Inter – Tech + 10 10 + NR Inter – Tech E PDSCH – 10 Log DL DL dB All TXj jc
TX i ic
TX i ic
Mi
PDSCH C/(I+N)
DL
With MIMO: CINR PDSCH = CINR PDSCH + G Div – DL + G Div RSRQ
460
TX i ic
TX i ic
10 Log N FB
TX ic
+ E i – RSSI DLRS
TX i ic
dB
Reference signal received quality (RSRQ)
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
Name
Value TX jc
Unit
Description
dBm
Received signal strength indicator (RSSI)
dBm
Downlink reference signals total noise (I+N)
dBm
SS and PBCH total noise (I+N)
dBm
PDCCH total noise (I+N) (Method 1: synchronised transmission and reception)
dBm
PDCCH total noise (I+N) (Method 2: non-synchronised transmission and reception)
dBm
PDSCH total noise (I+N) (Method 1: synchronised transmission and reception)
TX ic
i j n RSSI Sym TX ic --------------------------------------i Inter – Tech 10 10 10 +I 10 Log RSSI + + 10 12 + DL All TX j jc
RSSI
TX i ic
Inter – Tech
NR DL
TX ic
i + 10 Log N FB
TX jc
TX ic
i j n Sym DLRS - --------------------------------------- 10 10 + I Inter – Tech + 10 10 10 Log DL All TXj jc
TX i ic
I + N DLRS
Inter – Tech
+ NR DL
TX ic
i + 10 Log 2 N FB
TX jc
TX ic
i j n SS PBCH Sym ------------------------ --------------------- Inter – Tech 10 10 10 +I 10 Log + 10 DL All TXj jc
TX i ic
I + N SS PBCH
Inter – Tech
+ NR DL
+ 10 Log N SCa – FB N FB – SS PBCH
TX jc
TX i ic
I + N PDCCH
TX ic
i j n Sym PDCCH- ---------------------------------------- 10 10 + I Inter – Tech + 10 10 10 Log DL All TXj jc
TX i ic N Sym – PDCCH – Tech ---------------------------------------------- + NR Inter + 10 Log TX ic DL TX i ic i N SF – DL + N TDD – SSF TX jc
I +
TX ic i N PDCCH
TX ic
i j n Sym PDCCH ---------------------------------------- 10 10 + I Inter – Tech + 10 10 10 Log DL All TXj jc
TX ic i N TXi ic – Tech Sym – PDSCH + N Sym – PDCCH - + NR Inter + 10 Log ------------------------------------------------------------------DL TX ic i N SD Slot N Slot SF N SF – DL TX jc
TX i ic
I + N PDSCH
TX ic
i j n PDSCH Sym ---------------------------------------- Inter – Tech 10 10 10 +I 10 Log + 10 DL All TXj jc
TX i ic N Sym – PDSCH – Tech ---------------------------------------------- + NR Inter + 10 Log TX ic DL TX i ic i N SF – DL + N TDD – SSF
461
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©Forsk 2015
Name
Value TX jc
I +
TX ic i N PDSCH
Unit
Description
dBm
PDSCH total noise (I+N) (Method 2: non-synchronised transmission and reception)
Unit
Description
dBm
Nominal PUSCH power
dBm
Maximum allowed transmission power of a user equipment
dBm
Received PUSCH and PUCCH signal level
dBm
PUSCH and PUCCH EIRP of a user equipment
dB
Cyclic prefix factor, i.e., the ratio of the useful symbol energy to the total symbol energy
Unit
Description
dBm
PUSCH and PUCCH thermal noise
dBm
PUSCH and PUCCH noise
Unit
Description
dBm
Received PUSCH and PUCCH interference
dB
Interference reduction factor due to the co- and adjacent channel overlap
dB
Interference reduction factor due to the interfering mobile’s uplink traffic load
TX ic
i j n PDSCH Sym ---------------------------------------- Inter – Tech 10 10 10 +I 10 Log + 10 DL All TXj jc
TX ic i N TXi ic – Tech Sym – PDSCH + N Sym – PDCCH ------------------------------------------------------------------- + NR Inter + 10 Log DL TX ic i N SD Slot N Slot SF N SF – DL
6.2.8 Signal Level Calculation (UL) Name TX i ic
P O_PUSCH Mi
P Allowed
Value TX i ic
TX i ic
CINR PUSCH – Max + NR UL
TX i ic
TX i ic
+ n PUSCH PUCCH – 10 Log N FB
TX i ic TX i ic TX i ic Mi Min P Max 10 Log N FB + P O_PUSCH + FPC L Total Mi
Mi
C PUSCH PUCCH
TX i
EIRP PUSCH PUCCH – L Path – M Shadowing – Model – L Indoor + G Ant –L
TX i
Mi
Mi
– L Ant – L Body + f CP P
Mi
EIRP PUSCH PUCCH
With P
Mi
Mi
+G
Mi
–L
Mi
Mi
= P Allowed without power control adjustment and
P
Mi
Mi
= P Eff after power control adjustment TX i ic
10 Log 7 7.5 If D CP f CP
TX i ic
10 Log 6 7.5 If D CP
= Normal
= Extended
If M i is an interferer
0
6.2.9 Noise Calculation (UL) Name
Value TX i ic
TX i ic
n 0 + 10 Log N FB
n 0 – PUSCH PUCCH TX i ic
W FB 1000
TX i ic
n 0 – PUSCH PUCCH + nf
n PUSCH PUCCH
TX i ic
6.2.10 Interference Calculation (UL) Name Mj
I PUSCH PUCCH TX i ic – TX j jc
fO
M
j
f TL – UL
462
Value Mj
TX i ic – TX j jc
C PUSCH PUCCH + f O
TX i ic – TX j jc
Mj
+ f TL – UL + f ICIC – UL
TX i ic – TX j jc
10 Log r O
M
j 10 Log TL UL
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
Name
Value TX ic – TX jc j
TX ic – TX jc i j
i 10 Log p Collision
f ICIC – UL
Unit
Description
dB
Interference reduction factor due to static uplink ICIC using fractional frequency reuse
Unit
Description
dB
Uplink noise rise for any mobile Mi in cell centre of the interfered cell TXi(ic)
dB
Uplink noise rise for any mobile Mi in cell-edge of the interfered cell TXi(ic)
dBm
PUSCH and PUCCH total noise (I+N)
Unit
Description
dB
PUSCH and PUCCH C/N
Unit
Description
dB
PUSCH and PUCCH C/(I+N)
6.2.11 Noise Rise Calculation (UL) Name
Value
M
TX ic i NR UL
j TX i ic IPUSCH PUCCH non-ICIC M i n PUSCH PUCCH - ------------------------------------------- ----------------------------------------------------------------------------10 10 10 Log 10 + 10 All M j All TX jc j
Inter – Tech
+ NR UL
TX i ic
– n PUSCH PUCCH M
j TX i ic IPUSCH PUCCH n ICIC M PUSCH PUCCH i ------------------------------------------------------------------- ------------------------------------------- 10 10 10 Log 10 + 10 All Mj All TXj jc
TX i ic
NR UL – ICIC
Inter – Tech
+ NR UL
TX i ic
– n PUSCH PUCCH
For any mobile Mi in cell centre of the interfered cell TXi(ic): I +
TX ic i N PUSCH PUCCH
TX i ic
NRUL
TX i ic
+ n PUSCH PUCCH
For any mobile Mi in cell-edge of the interfered cell TXi(ic): TX i ic
TX i ic
NRUL – ICIC + n PUSCH PUCCH
6.2.12 C/N Calculation (UL) Name
Value TX i ic
Mi
C PUSCH PUCCH – n PUSCH PUCCH
Mi
CNR PUSCH PUCCH
With MIMO: Mi
TX i ic
Mi
UL
CNR PUSCH PUCCH = CNR PUSCH PUCCH + G Div – UL + G Div
6.2.13 C/(I+N) Calculation (UL) Name
Value For any mobile Mi in cell centre of the interfered cell TXi(ic): TX i ic
Mi
CNR PUSCH PUCCH – NR UL Mi
For any mobile Mi in cell-edge of the interfered cell TXi(ic):
CINR PUSCH PUCCH
TX i ic
Mi
CNR PUSCH PUCCH – NR ICIC – UL With MIMO: Mi
Mi
TX i ic
UL
CINR PUSCH PUCCH = CINR PUSCH PUCCH + G Div – UL + G Div
463
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©Forsk 2015
Name
Value
Unit
Description
M
M Mi TXi ic Mi i Max PAllowed – CINR PUSCH PUCCH – T M + M PC P Min B i
dBm
Effective transmission power of a user equipment after power control adjustment
i P Eff
UL
6.2.14 Calculation of Downlink Cell Resources Name
Value
Unit
Description
N Sym SRB
N SCa – FB N SD Slot N Slot SF
None
Number of modulation symbols per scheduler resource block
N Sym SSF
DwPTS
N SCa – FB N SD SSF
None
Number of DwPTS modulation symbols per scheduler resource block in the TDD special subframes
N SCa – FB
W FB --------F
None
Number of subcarriers per frequency block
None
Total number of modulation symbols in downlink
None
Number of modulation symbols in DwPTS
None
Number of PDSCH modulation symbols
None
Number of PDSCH modulation symbols in the DwPTS
None
Downlink reference signals overhead
None
Downlink reference signals overhead in the DwPTS
None
Number of symbols reserved for downlink reference signals in one scheduler resource block
DwPTS
TX ic i
TX ic i
N Sym – DL
N FB
TX i ic
TX i ic
N Sym – DwPTS TX i ic
R DL
TX ic i
N FB TX i ic
TX ic i
N Sym SRB N SF – DL + N Sym – DwPTS TX i ic
DwPTS
N TDD – SSF N Sym SSF
TX i ic
TX i ic
TX i ic
TX i ic
N Sym – DL – O DLRS – O PSS – O SSS – O PBCH – O PDCCH – O UERS
TX i ic
TX i ic
TX i ic
TX i ic
N Sym – DwPTS – O DLRS DwPTS – O PDCCH DwPTS
R DwPTS TX ic i
TX ic i
O DLRS
N FB
TX i ic
TX ic i
TX i ic
O DLRS DwPTS
N FB
8 16 24
TX i ic
N DLRS SRB
TX ic i
TX ic i
N DLRS SRB N SF – DL + O DLRS DwPTS TX i ic
TX i ic
N DLRS DwPTS N TDD – SSF TX ic
i if N Ant – TX = 1 TX ic
i if N Ant – TX = 2 TX ic
i if N Ant – TX = 4 or 8
N DLRS DwPTS
See "Calculation of Downlink Cell Resources" on page 538
None
Number of symbols reserved for downlink reference signals in DwPTS of one TDD special subframe
O PSS
2 NFB – SS PBCH N SCa – FB = 144
None
PSS overhead
O SSS
2 NFB – SS PBCH N SCa – FB = 144
None
SSS overhead
Extended CP: 216 Normal CP: 240
None
PBCH overhead
None
PDCCH overhead
TX i ic
TX i ic
O PBCH
TX ic
i if N SD – PDCCH = 0 : 0 TX ic
TX i ic
O PDCCH
TX ic
i i if N SD – PDCCH = 1 AND N Ant – TX 2 : TX ic
TX ic
TX ic
TX ic
i i i N i N SCa – FB – 4 N FB N SF – DL + O PDCCH DwPTS SD – PDCCH Otherwise: TX ic
TX ic
TX ic
i i N i SD – PDCCH N SCa – FB – 2 Min 4 N Ant – TX N FB
464
TX i ic
TX i ic
N SF – DL + O PDCCH DwPTS
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
Name
Value
Unit
Description
TX ic
i if N SD – PDCCH = 0 : 0 TX ic
TX i ic
O PDCCH DwPTS
TX ic
i i if N SD – PDCCH = 1 AND N Ant – TX 2 : TX ic
TX ic
i N i N SCa – FB – 4 N FB SD – PDCCH Otherwise: TX ic
PDCCH overhead in the DwPTS
TX i ic
N TDD – SSF TX ic
TX ic
i i Min 2 N i SD – PDCCH N SCa – FB – 2 Min 4 N Ant – TX N FB
TX ic i
N TDD – SSF
Without smart antennas and MIMO: 0 TX i ic
With smart antennas and without MIMO: 12 N FB TX ic i
O DMRS
TX ic i
With smart antennas and with MIMO: 24 N FB
TX i ic
N SF – DL TX ic i
N SF – DL
None
UE-specific reference signals or demodulation reference signal overhead
Without smart antennas and with SU-MIMO or MU-MIMO and TX i ic
TX i ic
N Ant – TX 4 : 24 N FB
TX i ic
N SF – DL
6.2.15 Calculation of Uplink Cell Resources Name
Value
Unit
Description
N Sym SRB
N SCa – FB N SD Slot N Slot SF
None
Number of modulation symbols per scheduler resource block
N SCa – FB
W FB --------F
None
Number of subcarriers per frequency block
None
Total number of modulation symbols in uplink
N Sym – UL – O ULSRS – O ULDRS
None
Nnumber of PUSCH modulation symbols
TX i ic
TX i ic N SCa – FB --------------------- N Sym – UL N Sym SRB
None
Uplink sounding reference signal overhead
TX ic i
TX i ic N SCa – FB - N Sym 2 --------------------– UL N Sym SRB
None
Uplink demodulation reference signal overhead
Unit
Description
bps
Maximum downlink throughput capacity of a UE category
Unit
Description
bps
Maximum uplink throughput capacity of a UE category
TX i ic
N Sym – UL TX i ic
R UL
O ULSRS
O ULDRS
TX ic
N i FB
TX ic
TX ic
i i – N FB – PUCCH N Sym SRB N SF – UL TX i ic
TX i ic
TX i ic
6.2.16 Calculation of Downlink UE Capacity Name
Value
Max TP UE – DL
i N i + N TDD – SSF Max – DL SF – DL N TBB TTI ---------------------------------------------------D Frame
TX ic
TX ic
6.2.17 Calculation of Uplink UE Capacity Name
Value
Max
Max – UL N SF – UL N TBB TTI ---------------D Frame
TP UE – UL
TX i ic
465
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©Forsk 2015
6.2.18 Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation Name
Value TX i ic
R DL
Unit
Description
kbps
Downlink peak RLC channel throughput
kbps
Downlink effective RLC channel throughput
kbps
Downlink application channel throughput
kbps
Downlink peak RLC cell capacity
kbps
Downlink effective RLC cell capacity
kbps
Downlink application cell capacity
kbps
Downlink peak RLC throughput per user
kbps
Downlink effective RLC throughput per user
kbps
Downlink application throughput per user
kbps
Uplink peak RLC channel throughput
M i B DL
--------------------------------D Frame TX ic i
R DL Mi
CTP P – DL
M i B DL
TX ic
i For proportional fair schedulers: --------------------------------- G MUG – DL D Frame
With SU-MIMO:
Mi
=
B DL
Max – M
Mi
B DL
i 1 + f SU – MIMO G SU – MIMO – DL – 1
With MU-MIMO in throughput coverage predictions: TX i ic
Mi
CTP P – DL G MU – MIMO – DL M
M
Mi
Mi
TX i ic
Mi
CTP P – DL TL DL – Max
Cap P – DL
M
M
i i Cap P – DL 1 – BLER BDL
i
Cap E – DL Mi
Mi
Mi f TP – Scaling - – TP Offset Cap E – DL -----------------------100 Mi
Cap A – DL
M
Mi
Mi f TP – Scaling - – TP Offset CTP E – DL -----------------------100 Mi
CTP A – DL
M
M
i i CTP P – DL 1 – BLER B DL
i
CTP E – DL
Mi
Cap P – DL ----------------------TX i ic N Users – DL
i
PUTP P – DL
Mi
Cap E – DL ----------------------TX i ic N Users – DL
Mi
PUTP E – DL
M
Mi
i
Mi f TP – Scaling - – TPOffset PUTP E – DL -----------------------100 Mi
PUTP A – DL
TX ic i
R UL
M i B UL
--------------------------------D Frame TX ic i
R UL
B
Mi
CTP P – UL
Mi
TX ic
i UL For proportional fair schedulers: --------------------------------- G MUG – UL D Frame
With SU-MIMO:
Mi
B UL
=
Max – TX ic
Mi
B UL
i 1 + f SU – MIMO G SU – MIMO – UL – 1
With MU-MIMO in throughput coverage predictions: Mi
TX i ic
CTP P – UL G MU – MIMO – UL
466
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AT330_TRR_E1
Name
Value
M
i i CTP P – UL 1 – BLER B UL
Description
kbps
Uplink effective RLC channel throughput
kbps
Uplink application channel throughput
kbps
Uplink peak RLC cell capacity
kbps
Uplink effective RLC cell capacity
kbps
Uplink application cell capacity
kbps
Uplink peak RLC allocated bandwidth throughput
kbps
Uplink effective RLC allocated bandwidth throughput
kbps
Uplink application allocated bandwidth throughput
Cap Mi M P – UL - ABTP P –i UL Min ---------------------- TX i ic N Users – UL
kbps
Uplink peak RLC throughput per user
Cap Mi M E – UL - ABTP E –i UL Min ---------------------- TXi ic N Users – UL
kbps
Uplink effective RLC throughput per user
kbps
Uplink application throughput per user
M
i
CTP E – UL M
Unit M
M
i
CTP A – UL Mi
M
i CTP E – UL
i
M f TP – Scaling i - – TP Offset -----------------------100 TX i ic
Mi
Cap P – UL
CTP P – UL TL UL – Max
M
i i Cap P – UL 1 – BLER B UL
M
i
Cap E – UL Mi
Cap A – UL
M
i ABTP P – UL
M
i
ABTP E – UL Mi
ABTP A – UL
Mi
PUTP P – UL
Mi
PUTP E – UL
Mi
PUTP A – UL
M
Mi
Mi f TP – Scaling - – TP Offset Cap E – UL -----------------------100 Mi
Mi
N FB – UL CTP P – UL ----------------TX i ic N FB Mi
M
M
i i ABTP P – UL 1 – BLER B UL Mi
Mi Mi f TP – Scaling - – TP Offset ABTP E – UL -----------------------100
Mi
M M f TP – Scaling i i - – TP Offset PUTP E – UL -----------------------100
6.2.19 Scheduling and Radio Resource Management Name
Value
Unit
Description
Sel Mi R Min – DL
TPD Min – DL ---------------------------
None
Resources allocated to a mobile to satisfy its minimum throughput demand in downlink
None
Resources allocated to a mobile to satisfy its minimum throughput demand in uplink
R Min – DL
None
Remaining downlink cell resources after allocation for minimum throughput demands
Sel i R Min – UL
None
Remaining uplink cell resources after allocation for minimum throughput demands
kbps
Remaining throughput demand for a mobile in downlink
Sel Mi
Sel Mi
CTP P – DL Sel Mi
TPD Min – UL ---------------------------
Sel Mi R Min – UL
Sel Mi
CTP P – UL TX i ic
R Rem – DL
TX i ic
R Rem – UL
Sel i TPD Rem – DL M
TX i ic
TL DL – Max –
Sel Mi
Sel Mi TX ic i TL UL – Max
–
M
Sel Mi Sel
Sel
Mi Mi Max Min TPD Max – DL – TPD Min – DL TP UE – DL
467
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©Forsk 2015
Name
Value
Sel i TPD Rem – UL
M M Max i i Min TPD Max – UL – TPD Min – UL TP UE – UL
M
Sel Mi
Sel
Sel Mi
TX i ic
CTP P – DL
Without MUG
G MUG – DL
Sel i CTP P – UL
Sel i CTP P – UL Without MUG
TX ic i G MUG – UL
Sel Mi RD Rem – DL
Description
kbps
Remaining throughput demand for a mobile in uplink
kbps
Downlink peak channel throughput with multi-user diversity gain (Proportional Fair)
kbps
Uplink peak channel throughput with multi-user diversity gain (Proportional Fair)
None
Remaining resource demand for a mobile in downlink
None
Remaining resource demand for a mobile in uplink
None
Resources allocated to a mobile to satisfy its maximum throughput demand in downlink
None
Resources allocated to a mobile to satisfy its maximum throughput demand in uplink
None
Effective remaining downlink resources in a cell (Proportional Demand)
Sel
CTP P – DL
M
Unit
M
Sel Mi
TPD Rem – DL ---------------------------Sel Mi
CTP P – DL Sel Mi RD Rem – UL
Sel Mi
TPD Rem – UL ---------------------------Sel Mi CTP P – UL
Sel
TX i ic
Mi R Rem – DL Proportional Fair: Min RD Rem – DL --------------------- N Sel
TX i ic
Mi R Rem – DL - Round Robin: Min RD Rem – DL -------------------N Sel Mi
R Max – DL
Sel Mi
TX i ic
RD Rem – DL Proportional Demand: R Eff – Rem – DL ---------------------------------Sel Mi
RDRem – DL
Sel Mi Sel i TPD Rem – DL ---------------------------Sel M i CTP P – DL M
Max C/I:
Sel
TX i ic
Mi R Rem – UL - Proportional Fair: Min RD Rem – UL -------------------N Sel
TX ic i
Mi R Rem – DL - Round Robin: Min RD Rem – DL -------------------N Sel Mi
R Max – UL
Sel Mi
TX i ic
RD Rem – UL Proportional Demand: R Eff – Rem – UL ---------------------------------Sel Mi
RDRem – UL
Sel Mi Sel Mi
TPD Rem – UL Max C/I: --------------------------Sel Mi
CTP P – UL TX i ic
R Eff – Rem – DL
468
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Name
Value
Unit
Description
TX ic i R Eff – Rem – UL
Sel M TXi ic i Min R Rem – UL RD Rem – UL Sel M i
None
Effective remaining uplink resources in a cell (Proportional Demand)
Sel Sel Mi Mi R Max – DL CTP E – DL Sel M Site i - Max 1 ----------------------------------------------------------------------------------------------------Sel Sel Mi Mi Site TP – R CTP S1 – DL Min – DL E – DL Sel M Site i
None
Site backhaul overflow ratio in downlink
Sel Sel Mi Mi R Max – UL CTP E – UL Sel M i Site Max 1 ------------------------------------------------------------------------------------------------------ Sel Sel Mi Mi Site R Min – UL CTP E – UL TPS1 – UL – Sel M i Site
None
Site backhaul overflow ratio in uplink
None
Total resources assigned to a mobile in downlink (Downlink traffic load of the mobile)
None
Total resources assigned to a mobile in uplink (Uplink traffic load of the mobile)
Unit
Description
kbps
Downlink peak RLC user throughput
kbps
Downlink effective RLC user throughput
kbps
Downlink application user throughput
kbps
Uplink peak RLC user throughput
kbps
Uplink effective RLC user throughput
kbps
Uplink application user throughput
Site
BHOF DL
Site
BHOF UL
Sel
Sel Mi
TL DL
Sel Mi
= R DL
M
Sel i
M
Sel i
R Mi Mi Max – DL CTP P – DL R Min – DL CTP P – DL + -----------------------------------------------Site BHOF DL -----------------------------------------------------------------------------------------------------------------Sel
Sel Mi
CTP P – DL Sel
Sel i TL UL M
=
Sel i R UL M
Sel Mi
Sel Mi
R Mi Mi Max – UL CTP P – UL R Min – UL CTP P – UL + -----------------------------------------------Site BHOF UL -----------------------------------------------------------------------------------------------------------------Sel
Sel Mi
CTP P – UL
6.2.20 User Throughput Calculation Name Sel Mi
UTP P – DL Sel Mi
UTP E – DL Sel Mi
UTP A – DL Sel Mi
UTP P – UL Sel Mi
UTP E – UL Sel i UTP A – UL M
Value Sel Mi
R DL
Sel Mi
CTP P – DL
Sel
Sel
Mi Mi UTP P – DL 1 – BLER B DL Sel Mi
Sel Mi
Sel
Mi f TP – Scaling - – TP Offset UTP E – DL -----------------------100 Sel Mi
R UL
Sel Mi
CTP P – UL
Sel
Sel
M Mi i UTP P – UL 1 – BLER B UL
Sel Mi
Sel Mi
Sel
Mi f TP – Scaling UTP E – UL ------------------------- – TP Offset 100
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6.3 Available Calculations 6.3.1 Point Analysis 6.3.1.1 Profile View The point analysis profile view displays the following calculation results for the selected transmitter based on the calculation algorithm described in "Signal Level Calculation (DL)" on page 501.
L
M
i
TX ic i
•
Downlink reference signal level C DLRS
•
Path loss L Path
•
Total losses L Total
,G
M
i
M
i
M
i
, L Ant , L Body , and f CP are not used in the calculations performed for the profile view.
6.3.1.2 Reception View Analysis provided in the reception view is based on path loss matrices. So, you can display received downlink reference signal levels from the cells for which calculated path loss matrices are available. For each cell, Atoll displays the received RSRP or reference signal, SS, or PDSCH signal levels. Reception level bar graphs show the RSRP or signal levels in decreasing order. The maximum number of bars in the graph depends on the studied signal level of the best server. The bar graph displays cells whose received RSRP are higher than their minimum RSRP thresholds and are within a 30 dB margin from the studied signal level of the best server. You can use a value other than 30 dB for the margin from the studied signal level of the best server, for example a smaller value for improving the calculation speed. For more information on defining a different value for this margin, see the Administrator Manual.
6.3.1.3 Interference View Analysis provided in the interference view is based on path loss matrices. So, you can display the received signal level from the best server and interfering signal levels from other cells for which calculated path loss matrices are available. For each cell, Atoll displays the best server RS, SS, or PDSCH signal level, and interference from other cells. Interference level bar graphs show the interference levels on different channels in decreasing order. The maximum number of bars in the graph depends on the highest interference level on the studied channel. The bar graph displays cells whose C/ N are higher than the minimum interferer C/N threshold and whose interference levels are within a 30 dB margin from the highest interference level on the studied channel. You can use a value other than 30 dB for the margin from the highest interference level on the studied channel, for example a smaller value for improving the calculation speed. For more information on defining a different value for this margin, see the Administrator Manual.
6.3.1.4 Details View Analysis provided in the details view is based on path loss matrices. So, you can display the received signal level from the best server and interfering signal levels from other cells for which calculated path loss matrices are available. For each cell, Atoll displays the RSRP and RS, SS, PBCH, PDCCH, and PDSCH signal levels, as well as interference levels on these channels from interfering cells. The results for the best server (first row) are displayed using bold italic characters. Other cells are listed in the decreasing order of RSRP. All the cells from which the received RSRP is higher than their minimum RSRP thresholds are listed in the table. As well, interference values are listed for all the cells whose C/N are higher than the minimum interferer C/N threshold and whose interference levels are within a 30 dB margin from the highest interference level on RS. You can use a value other than 30 dB for the margin from the highest interference level on RS, for example a smaller value for improving the calculation speed. For more information on defining a different value for this margin, see the Administrator Manual.
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6.3.2 Coverage Predictions 6.3.2.1 Downlink Signal Level Coverage Predictions The following coverage predictions are based on the received downlink reference signal levels: • • •
Coverage by Transmitter Coverage by Signal Level Overlapping Zones
For these calculations, Atoll calculates the received downlink reference signal level. Then, Atoll determines the selected display parameter on each pixel inside the cell’s calculation area. Each pixel within the calculation area of TXi(ic) is considered a non-interfering receiver. These coverage predictions do not depend on the traffic input. Therefore, these calculations are of special interest before and during the deployment stage of the network to study the coverage footprint of the system. L
Mi
, G
Mi
Mi
Mi
, L Ant , and L Body are not considered in the calculations performed for the downlink signal level based coverage
predictions. The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). For more information on downlink reference signal level calculations, see "Signal Level Calculation (DL)" on page 501. For more information on coverage area determination and available display options, see: • •
"Coverage Area Determination" on page 471. "Coverage Display Types" on page 472.
Coverage Area Determination Atoll uses parameters entered in the Condition tab of the coverage prediction properties dialogue to determine coverage areas to display. There are three possibilities. •
All Servers The coverage area of each cell TXi(ic) corresponds to the pixels where. TX ic
TX ic
TX ic
i i i MinimumThreshold C DLRS or L Total or L Path MaximumThreshold
•
Best Signal Level and a Margin The coverage area of each cell TXi(ic) corresponds to the pixels where. TX ic
TX ic
TX ic
i i i MinimumThreshold C DLRS or L Total or L Path MaximumThreshold
AND TX i ic TX j jc C DLRS Best C DLRS – M ji
Where M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels where the received downlink reference signal level from TXi(ic) is the highest. If M = 2 dB, Atoll considers pixels where the received downlink reference signal level from TXi(ic) is either the highest or within a 2 dB margin from the highest If M = -2 dB, Atoll considers pixels where the received downlink reference signal level from TXi(ic) is 2 dB higher than the received downlink reference signal levels from the cells which are 2nd best servers
•
Second Best Signal Level and a Margin The coverage area of each cell TXi(ic) corresponds to the pixels where. TX ic
TX ic
TX ic
i i i MinimumThreshold C DLRS or L Total or L Path MaximumThreshold
AND
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TX jc
nd i j C DLRS 2 Best C DLRS – M ji
Where M is the specified margin (dB). The 2nd Best function considers the second highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels where the received downlink reference signal level from TXi(ic) is the second highest. If M = 2 dB, Atoll considers pixels where the received downlink reference signal level from TXi(ic) is either the second highest or within a 2 dB margin from the second highest. If M = -2 dB, Atoll considers pixels where the received downlink reference signal level from TXi(ic) is 2 dB higher than the received downlink reference signal levels from the cells which are 3rd best servers.
Coverage Display Types A pixel of a coverage area is coloured if the calculated value of the selected display parameter is greater than or equal to the defined thresholds values. Coverage consists of several independent layers that can be displayed and hidden on the map. It is possible to display the coverage predictions with colours depending on any transmitter or cell attribute, and other criteria such as: • • • • • • •
Signal Level (dBm, dBµV, dBµV/m) Best Signal Level (dBm, dBµV, dBµV/m): Where cell coverage areas overlap, Atoll keeps the highest value of the signal level. Path Loss (dB) Total Losses (dB) Best Server Path Loss (dB): Where cell coverage areas overlap, Atoll determines the best cell (i.e., the cell with the highest downlink reference signal level) and evaluates the path loss from this cell. Best Server Total Losses (dB): Where cell coverage areas overlap, Atoll determines the best cell (i.e., the cell with the highest downlink reference signal level) and evaluates the total losses from this cell. Number of Servers: Atoll evaluates the number of cells that cover a pixel (i.e., the pixel falls within the coverage areas of these cells).
6.3.2.2 Effective Signal Analysis Coverage Predictions The following coverage predictions are based on the received downlink reference signal, SS, PDSCH, and PUSCH and PUCCH signal levels and noise, and take into account the receiver characteristics ( L
Mi
,G
Mi
Mi
Mi
, L Ant , and L Body ) when calculating the
required parameter: • •
Effective Signal Analysis (DL) Effective Signal Analysis (UL)
For these calculations, Atoll calculates the received signal level or C/N level at each pixel for the channel type being studied, i.e., RS, SS, PBCH, PDCCH, PDSCH, PUSCH and PUCCH. Each pixel within the calculation area of TXi(ic) is considered a noninterfering receiver. The properties of the non-interfering probe receiver are set by selecting a terminal, a mobility type, and a service. These coverage predictions do not depend on the traffic input. Therefore, these calculations are of special interest before and during the deployment stage of the network to study the coverage footprint of the system. The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). For more information on signal level calculations, see: • •
"Signal Level Calculation (DL)" on page 501. "Signal Level Calculation (UL)" on page 523.
For more information on C/N level calculations, see: • •
"C/N Calculation (DL)" on page 516. "C/N Calculation (UL)" on page 529.
For more information on coverage area determination and available display options, see: • •
472
"Coverage Area Determination" on page 473. "Coverage Display Types" on page 473.
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Coverage Area Determination These coverage predictions are best server coverage predictions, i.e., the coverage area of each cell comprises the pixels where the cell is the best server. Best server for each pixel is calculated as explained in "Best Server Determination" on page 535. Coverage Display Types A pixel of a coverage area is coloured if the calculated value of the selected display type parameter is greater than or equal to the defined thresholds values. Coverage consists of several independent layers that can be displayed and hidden on the map. It is possible to display the Effective Signal Analysis (DL) coverage prediction with colours depending on the following display options: • • • • • • • • • • •
RSRP (RS EPRE) Level (DL) (dBm) RS Signal Level (DL) (dBm) SS Signal Level (DL) (dBm) PBCH Signal Level (DL) (dBm) PDCCH Signal Level (DL) (dBm) PDSCH Signal Level (DL) (dBm) RS C/N Level (DL) (dB) SS C/N Level (DL) (dB) PBCH C/N Level (DL) (dB) PDCCH C/N Level (DL) (dB) PDSCH C/N Level (DL) (dB)
•
Delta Path Loss (dB): Atoll calculates the difference of the total losses from the second best serving cells ( L Total ) and
TX jc j
TX i ic
TX j jc
TX i ic
the total losses from the best serving cells ( L Total ) on each pixel of their coverage areas ( L Total – L Total ). Pixels are
•
coloured according to the thresholds defined in the coverage prediction. Total losses are calculated as explained in "Signal Level Calculation (DL)" on page 453. ICIC Cell-edge Areas: Based on the delta path loss calculation as above. Pixels are coloured according to the colours of the transmitter symbols on the map. The prediction is based on the delta path loss thresholds defined per cell.
It is possible to display the Effective Signal Analysis (UL) coverage prediction with colours depending on the following display options: • •
PUSCH & PUCCH Signal Level (UL) (dBm) PUSCH & PUCCH C/N Level (UL) (dB)
6.3.2.3 C/(I+N)-based Coverage Predictions The following coverage predictions are based on the received signal levels, total noise, and interference. • • • • • • • •
Coverage by C/(I+N) Level (DL) Service Area Analysis (DL) Coverage by Throughput (DL) Coverage by Quality Indicator (DL) Coverage by C/(I+N) Level (UL) Service Area Analysis (UL) Coverage by Throughput (UL) Coverage by Quality Indicator (UL)
These coverage predictions take into account the receiver characteristics ( L
Mi
,G
Mi
Mi
Mi
, L Ant , and L Body ) when calculating the
required parameter. For these calculations, Atoll calculates the received signal level, noise, and interference at each pixel. Each pixel within the calculation area of TXi(ic) is considered a non-interfering receiver. The properties of the non-interfering probe receiver are set by selecting a terminal, a mobility type, and a service. The downlink coverage predictions are based on the downlink traffic loads of the cells, and the uplink coverage predictions are based on the uplink noise rise values. These parameters can either be calculated by Atoll during the Monte Carlo simulations, or set manually by the user for all the cells. The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). For more information on RSRQ, RSSI, C/(I+N), (I+N), and bearer calculations, see: • •
"C/(I+N) and Bearer Calculation (DL)" on page 518. "C/(I+N) and Bearer Calculation (UL)" on page 532.
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For more information on thoughput calculations, see: •
"Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation" on page 547.
For more information on coverage area determination and available display options, see: • •
"Coverage Area Determination" on page 474. "Coverage Display Types" on page 474.
Coverage Area Determination These coverage predictions are all best server coverage predictions, i.e., the coverage area of each cell comprises the pixels where the cell is the best server. Best server for each pixel is calculated as explained in "Best Server Determination" on page 535. Coverage Display Types A pixel of a coverage area is coloured if the calculated value of the selected display type parameter is greater than or equal to the defined thresholds values. Coverage consists of several independent layers that can be displayed and hidden on the map. It is possible to display the Coverage by C/(I+N) Level (DL) coverage prediction with colours depending on the following display options: • • • • • • • • •
RSRQ Level (DL) (dB) RSSI Level (DL) (dBm) RS C/(I+N) Level (DL) (dB) SS C/(I+N) Level (DL) (dB) PBCH C/(I+N) Level (DL) (dB) PDCCH C/(I+N) Level (DL) (dB) SS & PBCH Total Noise (I+N) (DL) (dBm) PDSCH C/(I+N) Level (DL) (dB) PDSCH & PDCCH Total Noise (I+N) (DL) (dBm)
It is possible to display the Service Area Analysis (DL) coverage prediction with colours depending on the following display options: • • •
Bearer (DL) Modulation (DL): Modulation used by the bearer Service
It is possible to display the Coverage by Throughput (DL) coverage prediction with colours depending on the following display options: • • • • • • • • •
Peak RLC Channel Throughput (DL) (kbps) Effective RLC Channel Throughput (DL) (kbps) Application Channel Throughput (DL) (kbps) Peak RLC Cell Capacity (DL) (kbps) Effective RLC Cell Capacity (DL) (kbps) Application Cell Capacity (DL) (kbps) Peak RLC Throughput per User (DL) (kbps) Effective RLC Throughput per User (DL) (kbps) Application Throughput per User (DL) (kbps)
It is possible to display the Coverage by Quality Indicator (DL) coverage prediction with colours depending on the following display options: •
Quality indicators available in the document (Quality Indicators table): Atoll calculates the PDSCH C/(I+N) levels received from the best serving cells at each pixel of their coverage areas. From the C/(I+N), Atoll determines the best bearer available on each pixel. Then, for the calculated C/(I+N) and bearer, it determines the value of the selected quality indicator from the quality graphs defined in the reception equipment of the selected terminal.
It is possible to display the Coverage by C/(I+N) Level (UL) coverage prediction with colours depending on the following display options:
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• • •
PUSCH & PUCCH C/(I+N) Level (UL) (dB) PUSCH & PUCCH Total Noise (I+N) (UL) (dBm) Allocated Bandwidth (UL) (No. of Frequency Blocks)
•
PUSCH & PUCCH C/(I+N) Level for 1 Frequency Block (UL) (dB): PUSCH & PUCCH C/(I+N) level with N FB – UL = 1
•
Transmission Power (UL) (dBm)
M
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It is possible to display the Service Area Analysis (UL) coverage prediction with colours depending on the following display options: • • •
Bearer (UL) Modulation (UL): Modulation used by the bearer Service
It is possible to display the Coverage by Throughput (UL) coverage prediction with colours depending on the following display options: • • • • • • • • • • • •
Peak RLC Channel Throughput (UL) (kbps) Effective RLC Channel Throughput (UL) (kbps) Application Channel Throughput (UL) (kbps) Peak RLC Cell Capacity (UL) (kbps) Effective RLC Cell Capacity (UL) (kbps) Application Cell Capacity (UL) (kbps) Peak RLC Allocated Bandwidth Throughput (UL) (kbps) Effective RLC Allocated Bandwidth Throughput (UL) (kbps) Application Allocated Bandwidth Throughput (UL) (kbps) Peak RLC Throughput per User (UL) (kbps) Effective RLC Throughput per User (UL) (kbps) Application Throughput per User (UL) (kbps)
It is possible to display the Coverage by Quality Indicator (UL) coverage prediction with colours depending on the following display options: •
Quality indicators available in the document (Quality Indicators table): Atoll calculates the PUSCH and PUCCH C/(I+N) levels received at the best serving cells from each pixel of their coverage areas. From the C/(I+N), Atoll determines the best bearer available on each pixel. Then, for the calculated C/(I+N) and bearer, it determines the value of the selected quality indicator from the quality graphs defined in the reception equipment of the best serving cell.
6.3.2.4 Cell Identifier Collision Zones Coverage Prediction The Cell Identifier Collision Zones coverage prediction is based on the received downlink reference signal levels. Atoll calculates the received downlink reference signal level then Atoll determines the selected display parameter on each pixel inside the cell’s calculation area. Each pixel within the calculation area of TXi(ic) is considered a non-interfering receiver. L G
Mi
Mi
Mi
,
Mi
, L Ant , and L Body are not considered in the calculations.
The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). For more information on downlink reference signal level calculations, see "Signal Level Calculation (DL)" on page 501. For more information on coverage area determination and available display options, see: • •
"Coverage Area Determination" on page 475. "Coverage Display Types" on page 476.
Coverage Area Determination Atoll uses parameters entered in the Condition tab of the coverage prediction properties dialogue to determine coverage areas to display. It is possible to determine the coverage area based on the best signal level. The coverage area of each cell TXi(ic) corresponds to the pixels where: TX i ic TX i ic TX i ic TX i ic TX j jc MinimumThreshold C DLRS or L Total or L Path MaximumThreshold AND C DLRS Best C DLRS – M ji
Where M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels where the received downlink reference signal level from TXi(ic) is the highest. If M = 2 dB, Atoll considers pixels where the received downlink reference signal level from TXi(ic) is either the highest or within a 2 dB margin from the highest If M = -2 dB, Atoll considers pixels where the received downlink reference signal level from TXi(ic) is 2 dB higher than the received downlink reference signal levels from the cells which are 2nd best servers
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Coverage Display Types A pixel of a coverage area is coloured if the calculated value of the selected display parameter is greater than or equal to the defined thresholds values. Coverage consists of several independent layers that can be displayed and hidden on the map. It is possible to display the coverage predictions with colours per cell or: • •
Number of interferers Number of interferers per cell
6.3.3 Calculations on Subscriber Lists When calculations are performed on a list of subscribers by running the Automatic Server Allocation, Atoll calculates the path loss again for the subscriber locations and heights because the subscriber heights can be different from the default receiver height used for calculating the path loss matrices. Atoll calculates the following parameters for each subscriber in the list whose Lock Status is set to None. •
Serving Base Station and Reference Cell as described in "Best Server Determination" on page 535.
Atoll calculates the following parameters for each subscriber in the list that has a serving base station assigned and whose Lock Status is set to None or Server. • •
Azimuth ( ): Angle with respect to the north for pointing the subscriber terminal antenna towards its serving base station. Mechanical Downtilt ( ): Angle with respect to the horizontal for pointing the subscriber terminal antenna towards its serving base station.
Atoll calculates the remaining parameters for each subscriber in the list that has a serving base station assigned, using the properties of the default terminal and service. For more information, see: • • • • •
"Signal Level Calculation (DL)" on page 501. "Signal Level Calculation (UL)" on page 523. "C/(I+N) and Bearer Calculation (DL)" on page 518. "C/(I+N) and Bearer Calculation (UL)" on page 532. "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation" on page 547.
6.3.4 Monte Carlo Simulations The simulation process is divided into two steps. •
Generating a realistic user distribution as explained in "User Distribution" on page 476. Atoll generates user distributions as part of the Monte Carlo algorithm based on traffic data. The resulting user distribution complies with the traffic database and maps selected when creating simulations.
•
Scheduling and Radio Resource Management as explained under "Simulation Process" on page 479.
6.3.4.1 User Distribution During each simulation, Atoll performs two random trials. The first random trial generates the number of users and their activity status as explained in the following sections depending on the type of traffic input. • •
"Simulations Based on User Profile Traffic Maps and Subscriber Lists" on page 476. "Simulations Based on Sector Traffic Maps" on page 478.
Once all the user characteristics have been determined, a second random trial is performed to obtain their geographical locations weighted according to the clutter classes, and whether they are indoor or outdoor according to the percentage of indoor users per clutter class. Atoll determines the total number of users attempting connection in each simulation based on the Poisson distribution. This may lead to slight variations in the total numbers of users in different simulations. To have the same total number of users in each simulation of a group, add the following lines in the Atoll.ini file: [Simulation] RandomTotalUsers=0
6.3.4.1.1
Simulations Based on User Profile Traffic Maps and Subscriber Lists User profile environment based traffic maps: Each pixel of the map is assigned an environment class which contains a list of user profiles with an associated mobility type and a given density, i.e., number of users of a user profile per km².
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User profile traffic maps: Each polygon or line of the map is assigned a density of users with a given user profile and mobility type. If the map is composed of points, each point is assigned a number of users with given user profile and mobility type. Fixed subscribers listed in subscriber lists have a user profile assigned to each of them. User profiles model the behaviour of the different user categories. Each user profile contains a list of services and parameters describing how these services are accessed by the user. The number of users of each user profile is calculated from the surface area (SEnv) of each environment class map (or each polygon) and the user profile density (DUP). N Users = S Env D UP •
In case of user profile traffic maps composed of lines, the number of users of each user profile is calculated from the line length (L) and the user profile density (DUP) (users per km): N Users = L D UP
•
The number of users is a direct input when a user profile traffic map is composed of points.
Atoll calculates the probability for a user being active at a given instant in the uplink and in the downlink according to the service usage characteristics described in the user profiles, i.e., the number of voice calls or data sessions, the average duration of each voice call, or the volume of the data transfer in the uplink and the downlink in each data session. Voice Service (v) User profile parameters for voice type services are: • •
The user terminal equipment used for the service (from the Terminals table). The average number of calls per hour N Call .
•
The average duration of a call (seconds) D Call .
N Call D Call Calculation of the service usage duration per hour ( p 0 : probability of an active call): p 0 = ---------------------------3600 Calculation of the number of users trying to access the service v ( n v ): n v = N Users p 0 The activity status of each user depends on the activity periods during the call, i.e., the uplink and downlink activity UL
DL
factors defined for the voice type service v, f Act and f Act . Calculation of activity probabilities: UL
DL
Probability of being inactive: p Inactive = 1 – f Act 1 – f Act UL
UL
DL
Probability of being active in the uplink: p Active = f Act 1 – f Act DL
DL
UL
Probability of being active in the downlink: p Active = f Act 1 – f Act UL + DL
UL
DL
Probability of being active in the uplink and downlink both: p Active = f Act f Act Calculation of number of users per activity status: Number of inactive users: n v – Inactive = n v p Inactive UL
UL
Number of users active in the uplink: n v – Active = n v p Active DL
DL
Number of users active in the downlink: n v – Active = n v p Active UL + DL
UL + DL
Number of users active in the uplink and downlink both: n v – Active = n v p Active
Therefore, a connected user can be either active on both links, inactive on both links, active on UL only, or active on DL only. Data Service (d) User profile parameters for data type services are: •
The user terminal equipment used for the service (from the Terminals table).
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•
The average number of data sessions per hour N Session .
•
The average data volume (in kBytes) transferred in the downlink V
•
The average throughputs in the downlink
Calculation of activity probabilities: f
UL
DL TP Average
DL
and the uplink
and the uplink V
UL TP Average
UL
during a session.
for the service d.
UL
DL
N Session V 8 N Session V 8 DL = ------------------------------------------ and f = -----------------------------------------UL DL TP Average 3600 TP Average 3600 UL
DL
Probability of being inactive: p Inactive = 1 – f 1 – f UL
Probability of being active in the uplink: p Active = f DL
UL
DL
1 – f
Probability of being active in the downlink: p Active = f
DL
UL
1 – f UL + DL
Probability of being active in the uplink and downlink both: p Active = f
UL
f
DL
Calculation of number of users: Number of inactive users: n d – Inactive = N Users p Inactive UL
UL
Number of users active in the uplink: n d – Active = N Users p Active DL
DL
Number of users active in the downlink: n d – Active = N Users p Active UL + DL
UL + DL
Number of users active in the uplink and downlink both: n d – Active = N Users p Active Calculation of the number of active users trying to access the service d (nd): UL
UL + DL
DL
n d = n d – Active + n d – Active + n d – Active The user distribution per service and the activity status distribution between the users are average distributions. The service and the activity status of each user are randomly drawn in each simulation. Therefore, if you calculate several simulations at once, the average number of users per service and average numbers of inactive, active on UL, active on DL and active on UL and DL users, respectively, will correspond to calculated distributions. But if you check each simulation, the user distribution between services as well as the activity status distribution between users can be different in each of them.
6.3.4.1.2
Simulations Based on Sector Traffic Maps Sector traffic maps are also referred to as live traffic maps. Live traffic data from the O&M is spread over the best server coverage areas of the transmitters included in the traffic map. Either throughput demands per service or the number of active users per service are assigned to the coverage areas of each transmitter. For each transmitter TXi and each service s, •
Sector Traffic Maps (Throughputs) Atoll calculates the number of active users of each service s on UL and DL in the coverage area of TXi as follows: N
UL
UL
DL
TP Cell TP Cell DL = ---------------------- and N = ---------------------UL DL TP Average TP Average UL
Where TP Cell is the total uplink throughput demand defined in the map for any service s for the coverage area of the DL
transmitter, TP Cell is the total downlink throughput demand defined in the map for any service s for the coverage UL
DL
area of the transmitter, TP Average is the average uplink requested throughput of the service s, and TP Average is the average downlink requested throughput of the service s. •
Sector Traffic Maps (# Active Users) UL
Atoll directly uses the defined N and N coverage area using the service s.
478
DL
values, i.e., the number of active users on UL and DL in the transmitter
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At any given instant, Atoll calculates the probability for a user being active in the uplink and in the downlink as follows: Users active in the uplink and downlink both are included in the N
UL
UL accurately determine the number of active users in the uplink ( n Active
and N
DL
values. Therefore, it is necessary to UL + DL
DL
), in the downlink ( n Active ), and both ( n Active ).
As for the other types of traffic maps, Atoll considers both active and inactive users. The activity status of each user depends on the activity periods during the call, i.e., the uplink and downlink activity UL
DL
factors defined for the service, f Act and f Act . Calculation of activity probabilities: UL
DL
Probability of being inactive: p Inactive = 1 – f Act 1 – f Act UL
UL
DL
Probability of being active in the uplink: p Active = f Act 1 – f Act DL
DL
UL
Probability of being active in the downlink: p Active = f Act 1 – f Act UL + DL
UL
DL
Probability of being active in the uplink and downlink both: p Active = f Act f Act Calculation of the number of active users trying to access the service: We have: N
UL
UL + DL
UL
= p Active + p Active n and N
DL
UL + DL
DL
= p Active + p Active n
Where, n is the total number of active users in the transmitter coverage area using the service. Calculation of number of users per activity status: UL
UL + DL
DL
UL + DL
N p Active N p Active UL + DL Number of users active in the uplink and downlink both: n Active = Min -------------------------------------- -------------------------------------- or UL UL + DL DL + DL p Active + p Active p Active + p UL Active UL + DL
simply, n Active = Min N
UL
DL
f Act N
DL
UL
f Act UL
Number of users active in the uplink: n Active = N DL
UL
Number of users active in the downlink: n Active = N UL
DL
UL + DL
– n Active DL
UL + DL
– n Active
UL + DL
And, n = n Active + n Active + n Active
Calculation of the number of inactive users attempting to access the service: nv - p Inactive Number of inactive users: n Inactive = --------------------------1 – p Inactive The activity status distribution between users is an average distribution. In fact, in each simulation, the activity status of each user is randomly drawn. Therefore, if you calculate several simulations at once, average numbers of inactive, active on UL, active on DL and active on UL and DL users correspond to the calculated distribution. But if you check each simulation, the activity status distribution between users can be different in each of them.
6.3.4.2 Simulation Process LTE cells include intelligent schedulers and radio resource management features for regulating network traffic loads, optimising spectral efficiency, and satisfying the QoS demands of the users. Each Monte Carlo simulation in the Atoll LTE module is a snap-shot of the network with resource allocation carried out over a duration of 1 second (100 frames). The steps of this algorithm are listed below. The simulation process can be summed up into the following iterative steps. For each simulation, the simulation process, 1. Generates mobiles according to the input traffic data as explained in "User Distribution" on page 476. 2. Sets initial values for the following parameters: •
Cell transmission powers and EPREs are calculated from the maximum power and EPRE offset values defined by the user as explained in "Downlink Transmission Power Calculation" on page 485.
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©Forsk 2015 M
i
•
Mobile transmission power is set to the maximum mobile power ( P Max ).
•
Cell loads ( TL DL
TX ic i
TX ic i
, TL UL
TX ic i
, NR UL
TX ic i
TX ic i
TX ic i
, NRUL – ICIC , r DL – CE , and AU DL
) are set to their current values in the
Cells table. 3. Determines the best servers for all the mobiles generated for the simulation, and determines whether they are in the cell centre or cell-edge, as explained in "Best Server Determination" on page 535. 4. Sets the maximum PUSCH C/(I+N) of each cell to a value high enough to ensure that it will not cause any power constraints for cell-edge mobiles. TX i ic
For all the mobiles Mi served by any cell TXi(ic) in the uplink, Atoll calculates CINR PUSCH – Max as follows to ensure access to the highest bearer using all the frequency blocks. From fractional power control (see "Signal Level Calculation (UL)" on page 523), we know that: Mi
P Allowed = CINR PUSCH – Max + NRUL + n PUSCH PUCCH + FPC L Total
(1)
Where CINR PUSCH – Max is the maximum PUSCH C/(I+N), NRUL is the noise rise, n PUSCH PUCCH is the uplink thermal noise, FPC is the fractional power control factor, and L Total are the total losses. Mi
Transmitting P Allowed , a mobile Mi can access the highest bearer if: Mi
Mi
P Allowed – NR UL – n PUSCH PUCCH – L Total = T B
(2)
Mi
Where T B is the bearer selection thresholds of the highest bearer defined in the reception equipment used by the cell TXi(ic). Mi
Combining equations (1) and (2), we get the CINR PUSCH – Max for each mobile Mi that ensures access to the highest bearer: M
TX ic
M
i i i CINR PUSCH – Max = T B + 1 – FPC L Total
For each cell TXi(ic), the highest value is kept: TX ic
M
i i CINR PUSCH – Max = Max CINR PUSCH – Max All M i
For each iteration k, the simulation process, 5. Determines the downlink and uplink C/(I+N) and bearers for each of these mobiles as explained in "C/(I+N) and Bearer Calculation (DL)" on page 518 and "C/(I+N) and Bearer Calculation (UL)" on page 532 respectively. 6. Determines the channel throughputs at the mobile as explained in "Throughput Calculation" on page 538. 7. Performs radio resource management and scheduling to determine the amount of resources to allocate to each mobile according to the service priorities and throughput demands of each mobile using the selected scheduler as explained in "Scheduling and Radio Resource Management" on page 552. 8. Calculates the user throughputs after allocating resources to each mobile as explained in "User Throughput Calculation" on page 561.
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Figure 6.1: LTE Simulation Algorithm 9. Updates the traffic loads, and noise rise values of all the cells according to the resources in use and the total resources as follows: Calculation of Traffic Loads: Atoll calculates the traffic loads for all the cells TXi(ic). TX ic i
TL DL
=
M
TX ic i
RDL and TLUL i
Mi
=
M
RUL i
Mi TX i ic
For MU-MIMO, TL DL
=
MU – MIMO – DL Mi
RC DL
TX i ic
and TL UL
=
MU – MIMO – DL M i
MU – MIMO – UL Mi
RC UL
MU – MIMO – UL M i
Calculation of Uplink Noise Rise: For each victim cell TXi(ic), the uplink noise rise is calculated and updated by considering each interfering mobile Mj as explained in "Interference Calculation (UL)" on page 525. Calculation of Downlink Cell-edge Traffic Ratio: Atoll calculates the downlink cell-edge traffic ratio for all the cells as follows:
TX i ic
CE Mi
R DL
CE Mi
r DL – CE = --------------------TX i ic TL DL
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Where
M
M
CE i
R DL
©Forsk 2015
is the sum of the percentages of the downlink cell resources allocated to mobiles in the cell-edge.
CE i
Calculation of Downlink AAS Usage: Atoll calculates the downlink AAS usages for all the cells as follows: M
AAS
Mi
TX i ic
AAS = ------------------------------TX i ic TL DL
AU DL
Where
i
R DL
Mi
M
i
R DL
AAS
is the sum of the percentages of the downlink cell resources allocated to mobiles served by the
AAS
smart antennas. 10. Performs uplink noise rise control as follows: For each cell TXi(ic), Atoll calculates the difference between the current and the maximum noise rise values (in terms of IoT, i.e., the ratio of interference over thermal noise I/N which can be calculated from the noise rise: IoT = I/N = (I+N)/N - 1): TX ic
TX ic
NR i NR i UL UL – Max ----------------------- ------------------------------ 10 10 – 1 – 10 Log 10 – 1 = 10 Log 10
TX i ic
NR UL
TX ic i
Here NRUL
is the uplink noise rise of the cell TXi(ic) calculated in step 9.
The default method of uplink noise rise control is the best effort method. This means that uplink noise rise control is not part of the simulation convergence criteria. In other words, a simulation will converge once the downlink and uplink traffic loads and the uplink noise rise values are stable, irrespective of whether or not the noise rise control has been successful. The resulting noise rise values may be higher than the maximum allowed values defined per cell. If the resulting noise rise values are higher than the maximum allowed, this means that the noise rise control requires more iterations for stabilising the overall network’s noise rise than those needed by the simulation to converge. If you wish to achieve optimum noise rise control, you should decrease the uplink noise rise convergence threshold defined for the simulation so that the simulation takes more iterations to converge and allows noise rise control to reach its goal. The best effort noise rise control works as follows: •
TX i ic
If NR UL
0 , the cell TXi(ic) requests its neighbouring cells to decrease the uplink transmission powers of the
mobiles they serve (mobiles interfering TXi(ic)). • •
TX i ic
If 0 NR UL TX i ic
If NR UL
M NRC , the cell TXi(ic) does not request any change.
M NRC , the cell TXi(ic) requests its neighbouring cells to increase the uplink transmission powers of
the mobiles they serve (mobiles interfering TXi(ic)). Here M NRC is a noise rise control margin set to -1 dB by default. This value can be changed through Atoll.ini file by adding the following lines and setting it to a value other than "1" (positive values are considered as negative margins): [LTE] NR_CONTROL_MARGIN_MIN = 1 The uplink transmission powers of the mobiles in neighbouring cells of the cell TXi(ic) are adjusted according to the request in the next iteration by updating the maximum PUSCH C/(I+N) for the neighbouring cells TXj(jc): TX j jc
CINR PUSCH – Max
482
TX j jc
k
= Min CINR PUSCH – Max
TX i ic
k–1
– NRUL
TX jc
j CINR PUSCH – Max CINR PUSCH – Limit
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AT330_TRR_E1 TX jc j
Here CINR PUSCH – Max TX jc j
CINR PUSCH – Max
k
is the maximum PUSCH C/(I+N) for the neighbouring cell TXj(jc) in the current iteration k,
is the maximum PUSCH C/(I+N) for the neighbouring cell TXj(jc) in the previous iteration k-1,
k–1
TX jc j
CINR PUSCH – Limit is an upper limit fixed at 50 dB, and CINR PUSCH – Max is the maximum PUSCH C/(I+N) for the neighbouring cell TXj(jc) as calculated in step 4. If you wish to include the uplink noise rise control in the simulation convergence criteria, you can change the uplink noise rise control method from best effort to strict by setting the following option in the Atoll.ini file: [LTE] ULNRControlMethod = 1 The strict uplink noise rise control method makes the uplink noise rise control a part of the simulation convergence criteria. In other words, a simulation will converge once the downlink and uplink traffic loads and the uplink noise rise values are stable, and the uplink noise rise values of all the cells are less than or equal to the defined maximum uplink noise rise. The strict noise rise control works as follows: •
TX i ic
If NR UL
0 , the cell TXi(ic) requests its neighbouring cells to decrease the uplink transmission powers of the
mobiles they serve (mobiles interfering TXi(ic)). •
TX i ic
If NR UL
m NRC , the cell TXi(ic) requests its neighbouring cells to increase the uplink transmission powers of
the mobiles they serve (mobiles interfering TXi(ic)). Here m NRC is a noise rise control precision level set to 0.5 dB by default. This value can be changed through Atoll.ini file by adding the following lines: [LTE] ULNRControlPrecision = 5 Setting this option to X means that the precision will be taken as 0.X dB. The default value is 5 (= 0.5 dB). The uplink transmission powers of the mobiles in neighbouring cells of the cell TXi(ic) are adjusted according to the request in the next iteration by updating the maximum PUSCH C/(I+N) for the neighbouring cells TXj(jc): TX j jc
CINR PUSCH – Max
TX jc
k
j = Min CINR PUSCH – Max
TX jc j
Here CINR PUSCH – Max TX j jc
CINR PUSCH – Max
k
TX i ic
k–1
– NR UL
TX jc
j CINR PUSCH – Max CINR PUSCH – Limit
is the maximum PUSCH C/(I+N) for the neighbouring cell TXj(jc) in the current iteration k,
is the maximum PUSCH C/(I+N) for the neighbouring cell TXj(jc) in the previous iteration k-1, and
k–1
TX j jc
CINR PUSCH – Max is the maximum PUSCH C/(I+N) for the neighbouring cell TXj(jc) as calculated in step 4. At most six neighbouring cells are considered in uplink noise rise control. These six neighbouring cells are those whose served mobiles generate the highest interference for the studied cell. 11. Performs the convergence test to see whether the differences between the previous and current values are within the convergence thresholds. The convergence criteria are evaluated at the end of each iteration k, and can be written as follows: TX i ic
TL DL
k
TX i ic
TL UL
k
TX ic i
NR UL
k
=
TX ic
i Max TL DL All TX ic i
=
k
k
– TL UL
TX ic
i Max TL UL All TX ic i
=
TX i ic
– TL DL
TX i ic
TX ic
i Max NR UL All TX ic i
k – 1
TX ic i
k
– NR UL
k – 1
k – 1
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If TL DL
©Forsk 2015
TX ic i
Req
, TL UL
TX ic i
Req
, and NR UL
Req
are the simulation convergence thresholds defined when creating
the simulation, Atoll stops the simulation in the following cases. Convergence: Simulation has converged between iteration k - 1 and k, with the best effort uplink noise rise control, if: TX ic i
TL DL
TX ic i
k
TL DL
TX ic i
Req
AND TL UL
TX ic i
k
TL UL
TX ic i
Req
AND NR UL
TX ic i
k
NR UL
Req
Simulation has converged between iteration k - 1 and k, with the strict uplink noise rise control, if: TX i ic
TL DL
k
TX ic i
NRUL
TX i ic
TL DL
Req
TX i ic
TL UL
AND
TX i ic
k
TL UL
TX i ic
NR UL
AND
Req
TX i ic
k
NR UL
Req
AND
TX ic i
k
NR UL – Max
No convergence: Simulation has not converged even after the defined maximum number of iterations, with the best effort uplink noise rise control, if: TX i ic
TL DL
TX i ic
k
TL DL
TX i ic
Req
OR TL UL
TX i ic
k
TL UL
TX i ic
Req
OR NR UL
TX i ic
k
NR UL
Req
Simulation has not converged even after the defined maximum number of iterations, with the strict uplink noise rise control, if: TX i ic
TL DL
k
TX i ic
NRUL
TX i ic
TL DL
Req
OR
TX i ic
TL UL
TX i ic
k
TL UL
Req
OR
TX i ic
NR UL
TX i ic
k
NR UL
Req
OR
TX i ic
k
NR UL – Max
12. Repeats the above steps (from step 3.) for the iteration k+1 using the new calculated loads as the current loads. Simulation Results At the end of the simulation process, the main results obtained are: • • • • • • • • • • •
Downlink traffic loads Uplink traffic loads Uplink noise rise Downlink ICIC ratio Uplink ICIC noise rise Downlink AAS usage Number of co-scheduled MU-MIMO users (DL) Number of co-scheduled MU-MIMO users (UL) Maximum PUSCH C/(I+N) Number of connected users in downlink Number of connected users in uplink
These results can be used as input for C/(I+N)-based coverage predictions. In addition to the above parameters, the simulations also list the connection status of each mobile. Mobiles can be rejected due to: • • • •
•
No Coverage: If an LTE mobile does not have any best serving cell with cell type "LTE" and if an LTE-A mobile does not have any best serving primary cell with cell type "LTE-A PCell" (step 3.) No Service: If the mobile is not able to access a bearer in the direction of its activity (step 5.), i.e., UL, DL, or DL+UL, or if the mobile’s minimum throughput demand is higher than the UE throughput capacity. Scheduler Saturation: If the mobile is not in the list of mobiles selected for scheduling (step 7.). For LTE-A mobiles, this applies to the mobiles selected for scheduling by their primary cells. Resource Saturation: If all the cell resources are used up before allocation to the mobile or if, for a user active in uplink, the minimum uplink throughput demand is higher than the uplink allocated bandwidth throughput (step 7.). For LTE-A mobiles, this applies to their primary cells. Backhaul Saturation: If allocating resources to a mobile makes the effective RLC aggregate site throughputs exceed the maximum S1 interface throughputs defined for the site. This condition is only verified if the simulation was created with the Backhaul capacity check box selected (step 7.)
Connected mobiles (step 7.) can be: • • •
484
Connected UL: If a mobile active in UL is allocated resources in UL. Connected DL: If a mobile active in DL is allocated resources in DL. Connected DL+UL: If a mobile active in DL+UL is allocated resources in DL+UL.
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AT330_TRR_E1
6.4 Calculation Details The following sections describe all the calculation algorithms used in point analysis, calculation of coverage predictions, calculations on subscriber lists, and Monte Carlo simulations.
6.4.1 Downlink Transmission Power Calculation LTE eNode-Bs have a maximum transmission power which is shared by downlink channels. These channels include the downlink reference signals, SSS, PSS, PBCH, PDCCH (which is considered to include the PHICH and PCFICH), and PDSCH. The transmission powers of various channels are determined from the distribution of the total energy over a frame among the resource elements corresponding to these channels. The energy per resource element (EPRE) of the downlink reference signals is considered to be the reference with respect to which the EPRE of other channels is determined. You can either define the reference signal EPRE for each cell, or let Atoll calculate it from the cell’s maximum power and the EPRE offsets of other channels. The EPRE offsets of channels other than the downlink reference signals can be positive values meaning a relative boost with respect to the downlink reference signals EPRE, or negative values meaning a reduction with respect to the downlink reference signals EPRE. Atoll first determines the EPRE for each channel in the downlink and then the transmission power corresponding to each channel from the EPRE values. Input •
F : Subcarrier width (15 kHz).
•
W FB : Width of a frequency block (180 kHz).
•
N FB – SS PBCH : Number of frequency blocks that carry the SS and the PBCH (6).
•
N Slot SF : Number of slots per subframe (2).
•
D CP
•
N SD Slot : Number of symbol durations per slot (7 is D CP
•
TX ic i N SD – PDCCH
: Number of PDCCH symbol durations per subframe defined in the TXi(ic) frame configuration or, otherwise, global network settings.
•
N FB
TX i ic
: Cyclic prefix duration defined in the TXi(ic) frame configuration or, otherwise, global network settings. TX i ic
TX ic i
TX jc j
and N FB
TX i ic
is Normal, 6 if D CP
is Extended).
: Total number of frequency blocks defined in the frequency bands table for the channel
bandwidth used by the cell. •
TX i ic
TX j jc
N FB – CE0 and N FB – CE0 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell and PSS ID 0.
•
TX i ic
TX j jc
N FB – CE1 and N FB – CE1 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell and PSS ID 1.
•
TX i ic
TX j jc
N FB – CE2 and N FB – CE2 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell and PSS ID 2.
•
TX i ic
N SF – DL : Number of downlink subframes in the frame for the cell TXi(ic). It is equal to 10 for FDD frequency bands, and is determined from the cell’s TDD frame configuration for TDD frequency bands.
•
TX i ic
N TDD – SSF : Number of TDD special subframes (containing DwPTS, GP, and UpPTS) in the frame for the cell TXi(ic). It is equal to 0 for FDD frequency bands, and is determined from the cell’s TDD frame configuration for TDD frequency bands. TX i ic
TX i ic
N SF – DL and N TDD – SSF are determined as follows: TX i ic
TX i ic
Configuration
N SF – DL
N TDD – SSF
FDD
10
0
DSUUU-DSUUU
2
2
DSUUD-DSUUD
4
2
DSUDD-DSUDD
6
2
DSUUU-DSUUD
3
2
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TX ic i
Configuration
N SF – DL
N TDD – SSF
DSUUU-DDDDD
6
1
DSUUD-DDDDD
7
1
DSUDD-DDDDD
8
1
TX i ic
•
N Ant – TX : Number of transmission (downlink) antenna ports defined for the cell TXi(ic).
•
P Max : Maximum transmission power of the cell TXi(ic).
•
EPRE DLRS : Downlink reference signal EPRE of the cell TXi(ic).
TX i ic
TX ic i
TX i ic
You can either set the P Max TX ic i
TX i ic
or EPRE DLRS for a cell.
•
EPRE SS
•
EPRE PBCH : Energy per resource element offset for the PBCH with respect to the downlink reference signals EPRE.
•
EPRE PDCCH : Energy per resource element offset for the PDCCH with respect to the downlink reference signals EPRE.
•
EPRE PDSCH : Energy per resource element offset for the PDSCH with respect to the downlink reference signals EPRE.
: Energy per resource element offset for the SS with respect to the downlink reference signals EPRE.
TX i ic TX i ic TX i ic
Calculations If you have directly entered the downlink reference signal EPRE for the cell, you can skip the section "Calculation of Downlink Reference Signal EPRE" on page 486 and go directly to the section "Calculation of Other EPREs and Per-channel Powers" on page 491. Calculation of Downlink Reference Signal EPRE In LTE, a resource block (RB) is defined as 1 frequency block by 1 slot. However, schedulers are able to perform resource allocation every subframe (2 slots). 1 frequency block by 1 subframe (2 slots) is called a scheduler resource block (SRB) in the calculations below. The number of modulation symbols (resource elements) per scheduler resource block is calculated as follows: N Sym SRB = N SCa – FB N SD Slot N Slot SF Where N SCa – FB is the number of subcarriers per frequency block calculated as follows: W FB N SCa – FB = --------F The number of modulation symbols (resource elements) corresponding to the DwPTS per scheduler resource block in the TDD special subframes is calculated as follows: DwPTS
DwPTS
N Sym SSF = N SCa – FB N SD SSF DwPTS
Where N SD SSF is the number of DwPTS symbol durations (OFDM symbols) per special subframe, determined from the TDD special subframe configuration according to the 3GPP specifications as follows:
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AT330_TRR_E1
Special Subframe Configuration
Cyclic Prefix = Normal DwPTS
GP
N SD SSF
DwPTS
N SD SSF
0
3
1
Cyclic Prefix = Extended UpPTS
DwPTS
GP
UpPTS
N SD SSF
DwPTS
N SD SSF
10
3
8
9
4
8
3
2
10
3
9
2
3
11
2
10
1
4
12
1
3
7
5
3
9
8
2
6
9
3
9
1
7
10
2
8
11
1
GP
N SD SSF
1
2
GP
UpPTS UpPTS
N SD SSF
1
2
The total number of modulation symbols (resource elements) in downlink is calculated as follows: TX i ic
TX i ic
N Sym – DL = N FB
TX i ic
TX i ic
N Sym SRB N SF – DL + N FB
TX i ic
DwPTS
N TDD – SSF N Sym SSF
Out of the total number of modulation symbols, Atoll then determines the numbers of modulation symbols corresponding to each control channel as follows: The number of modulation symbols for the downlink reference signals The number of modulation symbols reserved for downlink reference signal transmission in one scheduler resource block depends on the number of transmission antenna ports:
TX i ic
For all subframes except the TDD special subframes: N Res SRB
8 = 16 24
TX ic
i if N Ant – TX = 1 TX ic
i if N Ant – TX = 2 TX ic
i if N Ant – TX = 4 or 8
For TDD special subframes: Special Subframe Configuration
0
1
2
3
Cyclic Prefix = Normal DwPTS
N SD SSF
3
9
10
11
Cyclic Prefix = Extended
TX ic i N Ant – TX
TX ic i N Res DwPTS
1
2
2
4
4
8
8
8
1
6
2
12
4
20
8
20
1
6
2
12
4
20
8
20
1
6
2
12
4
20
8
20
DwPTS
N SD SSF
3
8
9
10
TX ic i
TX ic i
N Ant – TX
N Res DwPTS
1
2
2
4
4
8
8
8
1
6
2
12
4
20
8
20
1
6
2
12
4
20
8
20
1
8
2
16
4
24
8
24
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Special Subframe Configuration
©Forsk 2015
Cyclic Prefix = Normal TX ic i
DwPTS
N SD SSF
4
12
5
3
6
9
7
10
8
11
Cyclic Prefix = Extended TX ic i
N Ant – TX
N Res DwPTS
1
8
2
16
4
24
8
24
1
2
2
4
4
8
8
8
1
6
2
12
4
20
8
20
1
6
2
12
4
20
8
20
1
6
2
12
4
20
8
20
TX ic i
DwPTS
N SD SSF
3
8
9
TX ic i
N Ant – TX
N Res DwPTS
1
2
2
4
4
8
8
8
1
6
2
12
4
20
8
20
1
6
2
12
4
20
8
20
This gives a number of reserved modulation symbols per frame: TX i ic
TX i ic
TX i ic
N Sym – Res = N SF – DL N FB
TX i ic
TX i ic
TX i ic
N Res SRB + N TDD – SSF N FB
TX i ic
N Res DwPTS
The number of modulation symbols used for downlink reference signal transmission in one scheduler resource block is:
TX i ic
For all subframes except the TDD special subframes: N DLRS SRB
8 = 8 6
TX ic
i if N Ant – TX = 1 TX ic
i if N Ant – TX = 2 TX ic
i if N Ant – TX = 4 or 8
For TDD special subframes: Special Subframe Configuration
0
1
488
Cyclic Prefix = Normal DwPTS
N SD SSF
3
9
TX ic i
Cyclic Prefix = Extended
TX ic i
N Ant – TX
N DLRS DwPTS
1
2
2
2
4
2
8
2
1
6
2
6
4
5
8
5
DwPTS
N SD SSF
3
8
TX ic i
TX ic i
N Ant – TX
N DLRS DwPTS
1
2
2
2
4
2
8
2
1
6
2
6
4
5
8
5
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
Special Subframe Configuration
Cyclic Prefix = Normal DwPTS
N SD SSF
2
10
3
11
4
12
5
3
6
9
7
10
8
11
TX ic i
Cyclic Prefix = Extended
TX ic i
N Ant – TX
N DLRS DwPTS
1
6
2
6
4
5
8
5
1
6
2
6
4
5
8
5
1
8
2
8
4
6
8
6
1
2
2
2
4
2
8
2
1
6
2
6
4
5
8
5
1
6
2
6
4
5
8
5
1
6
2
6
4
5
8
5
DwPTS
N SD SSF
9
10
3
8
9
TX ic i
TX ic i
N Ant – TX
N DLRS DwPTS
1
6
2
6
4
5
8
5
1
8
2
8
4
6
8
6
1
2
2
2
4
2
8
2
1
6
2
6
4
5
8
5
1
6
2
6
4
5
8
5
This gives a number of downlink reference signal modulation symbols per frame: TX i ic
TX i ic
TX i ic
N Sym – DLRS = N SF – DL N FB
TX i ic
TX i ic
TX i ic
N DLRS SRB + N TDD – SSF N FB
TX i ic
N DLRS DwPTS
The number of modulation symbols for the SS The primary and secondary synchonisation signals are transmitted on 1 symbol duration each in the 1st and the 6th downlink subframes, over the center 6 frequency blocks. Therefore, N Sym – PSS = 2 N FB – SS PBCH N SCa – FB = 144 N Sym – SSS = 2 N FB – SS PBCH N SCa – FB = 144 And, N Sym – SS = N Sym – PSS + N Sym – SSS = 288 The number of modulation symbols for the PBCH The physical broadcast channel is transmitted on four symbol durations in the 1st downlink subframe over the center 6 frequency blocks. The physical broadcast channel overlaps with the downlink reference signals, therefore, some modulation symbols reserved for downlink reference signals are subtracted: 216 for extended cyclic prefix 240 for normal cyclic prefix The number of modulation symbols for the PDCCH
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The physical downlink control channel can be transmitted over up to 4 symbol durations in each subframe. The number of symbol durations for the PDCCH is defined in the global network settings. The physical downlink control channel overlaps with the downlink reference signals, therefore, some modulation symbols reserved for downlink reference signals are subtracted: TX ic
i if N SD – PDCCH = 0 : TX i ic
N Sym – PDCCH = 0 TX ic
TX ic
i i if N SD – PDCCH = 1 AND N Ant – TX 2 : TX ic
TX i ic
N Sym – PDCCH =
TX ic
i N i SD – PDCCH N SCa – FB – 4 N FB TX i ic
TX ic i
N SF – DL
TX i ic
+ N SD – PDCCH N SCa – FB – 4 N FB
TX i ic
N TDD – SSF
Otherwise: TX ic
TX i ic
N Sym – PDCCH =
TX ic
TX ic
i i N i SD – PDCCH N SCa – FB – 2 Min 4 N Ant – TX N FB TX ic
TX ic
TX i ic
N SF – DL TX ic
i i i + Min 2 N SD – PDCCH N SCa – FB – 2 Min 4 N Ant – TX N FB
TX i ic
N TDD – SSF
The number of modulation symbols for the PDSCH The total number of modulation symbols in the frame excluding all the control channel modulation symbols gives the number of modulation symbols available for user data, i.e., for the PDSCH: TX i ic
TX i ic
TX i ic
TX i ic
TX i ic
N Sym – PDSCH = N Sym – DL – N Sym – Res – N Sym – SS – N Sym – PBCH – N Sym – PDCCH The energy per resource element for 1 modulation symbol (dBm/Sym) of the downlink reference signals is calculated as follows: •
If the reference signal EPRE calculation method is set to Calculated (equal distribution of unused EPRE): TX ic
TX i ic
EPRE DLRS
P i Max ------------------- TX i ic TX i ic DwPTS 10 N SD Slot N Slot SF N SF – DL + N TDD – SSF N SD SSF – = 10 Log 10 TX ic
TX ic
i i EPRE SS EPRE PBCH TX ic --------------------------------------------------------------------i 10 10 + N Sym – PBCH 10 10 L og N Sym – DLRS + N Sym – SS 10
+ N Sym – PDCCH 10
•
490
TX i ic EPRE PDCCH -----------------------------------10
+ N Sym – PDSCH 10
TX i ic EPRE PDSCH ------------------------------------ 10
If the reference signal EPRE calculation method is set to Calculated (with boost) or Calculated (without boost):
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1 TX ic
TX ic i
EPRE DLRS
P i Max ------------------- TX ic TX ic 10 i i DwPTS = 10 Log 10 N SD Slot N Slot SF N SF – DL + N TDD – SSF N SD SSF – TX ic
TX ic
i i EPRE SS EPRE PBCH TX ic --------------------------------------------------------------------i 10 10 10 L og N Sym – Res + N Sym – SS 10 + N Sym – PBCH 10
+ N Sym – PDCCH 10
TX ic i EPRE PDCCH -----------------------------------10
+ N Sym – PDSCH 10
TX ic i EPRE PDSCH ------------------------------------ 10
Calculation of Other EPREs and Per-channel Powers The energy per resource element for 1 modulation symbol (dBm/Sym) of the SS is calculated as follows: TX i ic
EPRE SS
TX i ic
TX i ic
= EPRE DLRS + EPRE SS
The energy per resource element for 1 modulation symbol (dBm/Sym) of the PBCH is calculated as follows: TX i ic
TX i ic
TX i ic
EPRE PBCH = EPRE DLRS + EPRE PBCH
The energy per resource element for 1 modulation symbol (dBm/Sym) of the PDCCH is calculated as follows: TX i ic
TX i ic
TX i ic
EPRE PDCCH = EPRE DLRS + EPRE PDCCH The energy per resource element for 1 modulation symbol (dBm/Sym) of the PDSCH is calculated as follows: TX i ic
TX i ic
TX i ic
EPRE PDSCH = EPRE DLRS + EPRE PDSCH If the reference signal EPRE calculation method is set to Calculated (with boost), the "boosted" RS energy per resource element is calculated as follows: TX i ic
EPRE DLRS
TX i ic
= EPRE DLRS
N TXi ic Sym – Res + 10 Log ------------------------ TXi ic N Sym – DLRS
The instantaneous downlink reference signal transmission power is calculated as follows: TX i ic
P DLRS
TX i ic
TX i ic
= EPRE DLRS + 10 Log 2 N FB TX ic i
Where 2 NFB
implies that at the instant when downlink reference signals are transmitted, they are transmitted using 2
subcarriers in each frequency block. The instantaneous SS transmission power is calculated as follows: TX i ic
P SS
TX i ic
= EPRE SS
+ 10 Log N SCa – FB N FB – SS PBCH
The instantaneous PBCH transmission power is calculated as follows: TX i ic
TX i ic
P PBCH = EPRE PBCH + 10 Log N SCa – FB N FB – SS PBCH Where N SCa – FB N FB – SS PBCH implies that at the instant when the SS and the PBCH are transmitted, they are transmitted using all the subcarriers in the centre 6 consecutive frequency blocks. The average PDCCH transmission power is calculated as follows: TX i ic
P PDCCH
TX i ic N Sym–PDCCH = EPRE PDCCH + 10 Log --------------------------------------------------------------------------------------------------------------------------------------- TX ic TX ic TX ic TX ic i i i i N SD – PDCCH N SF – DL + Min 2 N SD – PDCCH N TDD – SSF TX i ic
The average PDSCH transmission power is calculated as follows:
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TX ic i
P PDSCH
©Forsk 2015
TX ic i TX ic N Sym–PDSCH i = EPRE PDSCH + 10 Log -------------------------------------------------------------------------------------------------------------------- TX ic TX ic i N i N N – N Slot SF SD – PDCCH SF – DL SD Slot TX i ic TX i ic DwPTS + N SD SSF – Min 2 N SD – PDCCH N TDD – SSF
As the number of subcarriers used for the PDCCH and PDSCH transmission varies over time, i.e., from one symbol duration to the next, the instantaneous powers of the PDCCH and the PDSCH also vary over time. This is why average transmission powers are calculated and used in Atoll. EPRE and Transmission Power adjustment for ICIC The following applies to RS, PDCCH, and PDSCH EPREs for cells using downlink static ICIC. 1. No ICIC, time-switched FFR, and hard FFR Cell-edge and cell-centre frequency blocks are not transmitted at the same time. Therefore, TX i ic
TX i ic
EPRE DLRS CC = EPRE DLRS
TX i ic
EPRE PDCCH CC
TX i ic
EPRE PDSCH CC TX i ic
TX i ic
TX i ic
TX i ic TX i ic N FB N FB and EPRE DLRS CE = EPRE DLRS ---------------- ----------------TX i ic TX i ic N FB – CC N FB – CE
TX i ic
TX i ic
TX i ic
TX ic i
TX ic i
TX i ic TX i ic N FB N FB = EPRE PDCCH ----------------and EPRE PDCCH CE = EPRE PDCCH ----------------TX i ic TX i ic N FB – CC N FB – CE
TX i ic
TX i ic TX i ic N FB N FB and EPRE PDSCH CE = EPRE PDSCH ----------------= EPRE PDSCH ----------------TX ic TX ic i i N FB – CC N FB – CE
TX i ic
TX i ic
P DLRS CC = P DLRS CE = P DLRS TX i ic
TX i ic
TX i ic
TX i ic
TX i ic
TX i ic
P PDCCH CC = P PDCCH CE = P PDCCH P PDSCH CC = P PDSCH CE = P PDSCH 2. Soft and partial soft FFR Cell-edge and cell-centre frequency blocks are transmitted at the same time; therefore, power is divided among cellcentre and cell-edge frequency blocks. Therefore, we have, TX i ic
TX i ic
EPRE DLRS CC = EPRE DLRS
TX i ic
TX i ic TX i ic TX i ic N FB ---------------------------------------------------------------------- and EPRE DLRS CE = EPRE DLRS CC CE TX ic TX ic TX i ic i N i FB – CE + N FB – CC CE TX i ic
TX i ic TX i ic TX i ic TX i ic TX i ic N FB - and EPRE PDCCH EPRE PDCCH CC = EPRE PDCCH -------------------------------------------------------------------- CE = EPRE PDCCH CC CE TX ic TX ic TX i ic i N i FB – CE + N FB – CC CE
TX i ic
EPRE PDSCH CC
TX i ic
TX i ic TX i ic TX i ic N FB = EPRE PDSCH ---------------------------------------------------------------------- and EPRE PDSCH CE = EPRE PDSCH CC CE TX i ic TX i ic TX i ic N FB – CE + N FB – CC CE
TX i ic
P DLRS CC = P DLRS
TX i ic
P PDCCH CC
492
TX i ic
TX i ic
TX i ic
TX i ic
TX i ic TX i ic EPRE EPRE DLRS CC DLRS CE - and P DLRS ---------------------------- CE = P DLRS ----------------------------TX i ic TX i ic EPRE DLRS EPRE DLRS
TX i ic
TX i ic
TX i ic
TX i ic TX i ic EPRE PDCCH CC EPRE PDCCH CE - and P PDCCH = P PDCCH -------------------------------- CE = P PDCCH --------------------------------TX i ic TX i ic EPRE PDCCH EPRE PDCCH
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
TX ic i P PDSCH CC
=
TX ic i
In the above, CE TX i ic
If CE
TX ic i P PDSCH
TX ic i
TX ic i
TX ic TX ic EPRE PDSCH CC EPRE PDSCH CE i i - and P PDSCH ------------------------------- CE = P PDSCH -------------------------------TX ic TX ic i i EPRE PDSCH EPRE PDSCH
EPRE CE is the cell-edge power boost for cell TXi(ic)’s frame configuration. By definition: CE = ----------------EPRE CC TX i ic
is left empty, it is automatically calculated as follows: CE
TX i ic
TX i ic
N FB – CC = ----------------TX i ic N FB – CE
TX i ic
N FB – CC and N FB – CE are respectively the numbers of frequency blocks in cell centre and cell-edge of TXi(ic). Number of frequency blocks in
ICIC mode
Cell centre
Cell edge
TX i ic
No FFR
N FB
Time-switched FFR
N FB
TX i ic
TX i ic
N FB – CEx TX i ic
Soft FFR
TX i ic
TX i ic
N FB – CEx
TX i ic
Hard FFR
Partial soft FFR
TX i ic
N FB
N FB TX i ic
N FB
TX i ic
TX ic
N FB – CEx
TX i ic
TX i ic
– N FB – CEx TX ic
N FB – CEx TX ic
i i i – N FB – CE0 + N FB – CE1 + N FB – CE2
TX i ic
TX i ic
N FB – CEx
TX i ic
Where N FB – CEx can be N FB – CE0 , N FB – CE1 , or N FB – CE2 depending on the PSS ID of TXi(ic). Output TX ic i
•
EPRE DLRS : Energy per resource element of the downlink reference signals for cell TXi(ic).
•
EPRE SS
•
EPRE PBCH : Energy per resource element of the PBCH for cell TXi(ic).
•
EPRE PDCCH : Energy per resource element of the PDCCH for cell TXi(ic).
•
EPRE PDSCH : Energy per resource element of the PDSCH for cell TXi(ic).
•
P DLRS : Instantaneous transmission power of the downlink reference signals for cell TXi(ic).
•
P SS
TX i ic
: Energy per resource element of the SS for cell TXi(ic).
TX i ic TX i ic TX i ic
TX ic i TX i ic
: Instantaneous transmission power of the SS for cell TXi(ic).
TX i ic
•
P PBCH : Instantaneous transmission power of the PBCH for cell TXi(ic).
•
P PDCCH : Average transmission power of the PDCCH for cell TXi(ic).
•
P PDSCH : Average transmission power of the PDSCH for cell TXi(ic).
TX i ic TX i ic
6.4.2 Co- and Adjacent Channel Overlaps Calculation An LTE network can consist of cells that use different channel bandwidths. Therefore, the start and end frequencies of all the channels may not exactly coincide. Channel bandwidths of cells can overlap each other with different ratios.
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Figure 6.2: Co-Channel and Adjacent Channel Overlaps The following sections describe how the co- and adjacent channel overlaps are calculated between the channels used by any studied cell TXi(ic) and any other cell TXj(jc) of the network. In terms of interference calculation, the studied cell can be considered a victim of interference received from the other cells that might be interfering the studied cell. TX ic i
If the studied cell is assigned a channel number N Channel , it receives co-channel interference on the channel bandwidth of TX i ic
TX i ic
N Channel , and adjacent channel interference on the adjacent channel bandwidths, i.e., corresponding to N Channel – 1 and TX i ic
N Channel + 1 . In order to calculate the co- and adjacent channel overlaps between two channels, it is necessary to calculate the start and end frequencies of both channels (explained in "Conversion From Channel Numbers to Start and End Frequencies" on page 494). Once the start and end frequencies are known for the studied and other cells, the co- and adjacent overlaps and the total overlap ratio are calculated as respectively explained in: • • •
"Co-Channel Overlap Calculation" on page 495. "Adjacent Channel Overlap Calculation" on page 496. "Total Overlap Ratio Calculation" on page 496.
6.4.2.1 Conversion From Channel Numbers to Start and End Frequencies Input •
TX i ic
TX j jc
F Start – Band and F Start – Band : Start frequencies of the frequency bands assigned to the cells TXi(ic) and TXj(jc). F Start – Band can be the start frequency of a TDD frequency band ( F Start – TDD ), or the uplink or the downlink start frequency of an FDD frequency band ( F Start – FDD – UL or F Start – FDD – DL ). First – TX i ic
First – TX j jc
•
N Channel
•
N Channel and N Channel : Channel numbers assigned to cells TXi(ic) and TXj(jc).
TX i ic
and N Channel
: First channel numbers the frequency band assigned to the cells TXi(ic) and TXj(jc).
TX j jc
For FDD networks, Atoll considers that the same channel number is assigned to a cell in the downlink and uplink, i.e., the channel number you assign to a cell is considered for uplink and downlink both.
494
TX i ic
TX j jc
•
W Channel and W Channel : Bandwidths of the channels assigned to cells TXi(ic) and TXj(jc).
•
ICS Band and ICS Band : Inter-channel spacing of the frequency bands assigned to cells TXi(ic) and TXj(jc).
•
CN Band and CN Band : Channel number step of the frequency bands assigned to cells TXi(ic) and TXj(jc).
TX i ic
TX i ic
TX j jc
TX j jc
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
Calculations Channel numbers are converted into start and end frequencies as follows: For cell TXi(ic): TX ic i F Start
TX i ic
F End
=
TX ic i F Start – Band
TX i ic
N TXi ic – N First – TX i ic TX ic TX ic i i Channel Channel - + W Channel + ICS Band ------------------------------------------------------TX i ic CN Band TX i ic
= F Start + W Channel
For cell TXj(jc): TX j jc
F Start
TX j jc
F End
N TXj jc – N First – TX j jc TX j jc TX j jc Channel Channel - = F Start – Band + W Channel + ICS Band ------------------------------------------------------TX jc j CN Band TX j jc
TX j jc
TX j jc
= F Start + W Channel
Output TX ic i
TX jc j
•
F Start and F Start : Start frequencies for the cells TXi(ic) and TXj(jc).
•
F End
TX i ic
TX j jc
and F End
: End frequencies for the cells TXi(ic) and TXj(jc).
6.4.2.2 Co-Channel Overlap Calculation Input •
TX i ic
TX j jc
F Start
and F Start : Start frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel
Numbers to Start and End Frequencies" on page 494. •
TX i ic
TX j jc
F End
and F End
: End frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel
Numbers to Start and End Frequencies" on page 494. •
TX ic i
W Channel : Bandwidth of the channel assigned to the studied cell TXi(ic).
Calculations Atoll first verifies that co-channel overlap exists between the cells TXi(ic) and TXj(jc). Co-channel overlap exists if: TX i ic
TX j jc
F Start F End
TX i ic
AND F End
TX j jc
F Start
Otherwise there is no co-channel overlap. Atoll calculates the bandwidth of the co-channel overlap as follows: TX i ic – TX j jc
W CCO
TX jc
TX ic
TX jc
TX ic
j i j i = Min FEnd F End – Max F Start F Start
The co-channel overlap ratio is given by: TX i ic – TX j jc
r CCO
TX ic – TX jc i j
W CCO = ---------------------------------TX j jc W Channel
Output •
TX i ic – TX j jc
r CCO
: Co-channel overlap ratio between the cells TXi(ic) and TXj(jc).
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©Forsk 2015
6.4.2.3 Adjacent Channel Overlap Calculation Input •
TX ic i
TX jc j
F Start
and F Start : Start frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel
Numbers to Start and End Frequencies" on page 494. •
TX i ic
TX j jc
F End
and F End
: End frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel
Numbers to Start and End Frequencies" on page 494. •
TX i ic
W Channel : Bandwidth of the channel assigned to the studied cell TXi(ic).
Calculations Atoll first verifies that adjacent channel overlaps exist between (the lower-frequency and the higher-frequency adjacent channels of) the cells TXi(ic) and TXj(jc). Adjacent channel overlap exists on the lower-frequency adjacent channel if: TX i ic
TX i ic
TX j jc
F Start – W Channel F End
TX i ic
TX j jc
AND F Start F Start
Adjacent channel overlap exists on the higher-frequency adjacent channel if: TX i ic
F End
TX j jc
F End
TX i ic
AND F End
TX i ic
TX j jc
+ W Channel F Start
Otherwise there is no adjacent channel overlap. Atoll determines the adjacent channel overlap ratio as follows: Bandwidth of the lower-frequency adjacent channel overlap: TX i ic – TX j jc
W ACO
L
TX jc
TX ic
TX jc
TX ic
TX ic
j i j i i = Min F End F Start – Max F Start F Start – W Channel
The lower-frequency adjacent channel overlap ratio is given by: TX i ic – TX j jc
W ACO L = ---------------------------------TX j jc W Channel
TX i ic – TX j jc
r ACO
L
Bandwidth of the higher-frequency adjacent channel overlap: TX i ic – TX j jc
W ACO
H
TX j jc
TX i ic
= Min F End F End
TX ic
TX jc
TX ic
i j i + W Channel – Max F Start F End
The higher-frequency adjacent channel overlap ratio is given by: TX i ic – TX j jc
W ACO H = ---------------------------------TX jc j W Channel
TX i ic – TX j jc
r ACO
H
The adjacent channel overlap ratio is given by: TX i ic – TX j jc
r ACO
TX i ic – TX j jc
= r ACO
L
TX i ic – TX j jc
+ r ACO
H
Output •
TX ic – TX jc i j
r ACO
: Adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc).
6.4.2.4 Total Overlap Ratio Calculation Input •
TX i ic – TX j jc
r CCO
: Co-channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Co-Channel Overlap
Calculation" on page 495.
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AT330_TRR_E1
•
TX ic – TX jc i j
r ACO
: Adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Adjacent Channel
Overlap Calculation" on page 496. •
TX ic i
f ACS
: Adjacent channel suppression factor defined for the frequency band of the cell TXi(ic).
Calculations The total overlap ratio is: TX ic – TX jc i j rO
=
TX ic – TX jc i j r CCO
+
TX ic – TX jc i j r ACO
10
TX i ic – f ACS ----------------------10
Output •
TX i ic – TX j jc
rO
: Total co- and adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc).
6.4.3 Subframe Pattern Collision Calculation Subframe transmission and reception patterns can be defined for each cell using the Almost Blank Subframe (ABS) Pattern field. The ABS pattern is a bit map, i.e., a series of 0’s and 1’s where each bit corresponds to one subframe. In an ABS pattern, each 0 signifies a normal subframe and 1 implies an almost blank subframe. Almost blank subframes do not carry any traffic. Only reference signals are transmitted over an ABS. For example, the ABS pattern "0100001000" means that subframes 1 and 6 are almost blank subframes whereas all the other subframes are normal subframes carrying traffic. ABS patterns are used in conjunction with cell range expansion for eICIC (enhanced inter-cell interference coordination, also known as time-domain ICIC) in an effort to minimise cell-edge interference between macro and small cells in heterogeneous LTE networks (HetNets). In order to calculate the collision between normal and almost blank subframes, the cells’ ABS patterns must be normalised, and the used downlink, uplink, and special subframe patterns determined from the ABS patterns. These calculations are respectively explained in: • • •
"Subframe Pattern Normalisation" on page 497. "Determination of Effective Subframe Patterns" on page 498. "Calculation of Subframe Collision Probabilities" on page 499.
6.4.3.1 Subframe Pattern Normalisation Prior to the calculation of subframe collision probabilities, Atoll normalises the different ABS pattern lengths in order to perform logical (bit by bit) AND and OR operations afterwards. ABS patterns are normalised as follows: 1. The standard length of the ABS pattern of a cell is determined from its frequency band’s duplexing method and, in case the cell’s frequency band is a TDD band, from the cell’s TDD frame configuration. The standard lengths of the ABS pattern bit maps as defined by the 3GPP are as follows: • • • •
FDD cells: 40 bits TDD cells using the frame configuration 0: 70 bits TDD cells using the frame configuration 1 through 5: 20 bits TDD cells using the frame configuration 6: 60 bits
The normalised ABS pattern length used in Atoll is 80 bits, which covers all the standard lengths. ABS patterns of different lengths are normalised to 80 bits by Atoll. 2. The ABS pattern is corrected to match the standard ABS pattern lengths determined in step 1.: •
If the ABS pattern contains an asterisk, the pattern of 0’s and 1’s leading the asterisk is cyclically repeated until it matches the standard ABS pattern length. Any 0’s and 1’s entered after an asterisk will be ignored. FDD example: “0100010000*” = “0100010000010001000001000100000100010000”
•
If the ABS pattern is shorter than the standard ABS pattern length, it is filled with 0’s to match the standard ABS pattern length. FDD example: “01000100000100010000” = “0100010000010001000000000000000000000000”
•
If the ABS pattern is longer than the standard ABS pattern length, it is truncated to match the standard ABS pattern length. FDD example: “01000100000100010000010001000001000100000111110000” = “0100010000010001000001000100000100010000”
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•
©Forsk 2015
If the ABS pattern is empty, it means that there are no almost blank subframes defined and all the subframes can carry traffic. FDD example: NULL = “0” = “0*” = “0000000000000000000000000000000000000000”
3. The ABS pattern determined in step 2. is resized to 80 bits. More precisely, the ABS pattern is concatenated with itself. Examples: •
FDD: “0100010000010001000001000100000100010000” = 01000100000100010000010001000001000100000100010000010001000001000100000100010000
•
TDD frame configuration 0: “0100010000010001000001000100000100010000010001000001000100000100010000” = 01000100000100010000010001000001000100000100010000010001000001000100000100010000
•
TDD frame configurations 1 through 5: “01000100000100010000” = 01000100000100010000010001000001000100000100010000010001000001000100000100010000
•
TDD frame configuration 6: “010001000001000100000100010000010001000001000100000100010000” = 01000100000100010000010001000001000100000100010000010001000001000100000100010000
Once the ABS pattern SFP ABS has been normalised, it is inverted to determine the used subframe pattern SFP Used that is used in further calculations: SFP Used = !SFP ABS
6.4.3.2 Determination of Effective Subframe Patterns Effective downlink, uplink, and special subframe patterns ( SFP DL , SFP UL , and SFP SSF ) are determined as follows by applying masks ( SFM DL , SFM UL , and SFM SSF ) to the normalised used subframe patterns SFP Used determined as explained in "Subframe Pattern Normalisation" on page 497: SFP DL = SFP Used AND SFM DL SFP UL = SFP Used AND SFM UL SFP SSF = SFP Used AND SFM SSF SFM DL , SFM UL , and SFM SSF are, respectively, the downlink, uplink and special subframe masks listed below: FDD SFM DL SFM UL
11111111111111111111111111111111111111111111111111111111111111111111111111111111
SFM SSF TDD frame configuration 0-DSUUU DSUUU SFM DL
10000100001000010000100001000010000100001000010000100001000010000100001000010000
SFM UL
00111001110011100111001110011100111001110011100111001110011100111001110011100111
SFM SSF
01000010000100001000010000100001000010000100001000010000100001000010000100001000
TDD frame configuration 1-DSUUD DSUUD SFM DL
10001100011000110001100011000110001100011000110001100011000110001100011000110001
SFM UL
00110001100011000110001100011000110001100011000110001100011000110001100011000110
SFM SSF
01000010000100001000010000100001000010000100001000010000100001000010000100001000
TDD frame configuration 2-DSUDD DSUDD
498
SFM DL
10011100111001110011100111001110011100111001110011100111001110011100111001110011
SFM UL
00100001000010000100001000010000100001000010000100001000010000100001000010000100
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SFM SSF
01000010000100001000010000100001000010000100001000010000100001000010000100001000
TDD frame configuration 3-DSUUU DDDDD SFM DL
10000111111000011111100001111110000111111000011111100001111110000111111000011111
SFM UL
00111000000011100000001110000000111000000011100000001110000000111000000011100000
SFM SSF
01000000000100000000010000000001000000000100000000010000000001000000000100000000
TDD frame configuration 4-DSUUD DDDDD SFM DL
10001111111000111111100011111110001111111000111111100011111110001111111000111111
SFM UL
00110000000011000000001100000000110000000011000000001100000000110000000011000000
SFM SSF
01000000000100000000010000000001000000000100000000010000000001000000000100000000
TDD frame configuration 5-DSUDD DDDDD SFM DL
10011111111001111111100111111110011111111001111111100111111110011111111001111111
SFM UL
00100000000010000000001000000000100000000010000000001000000000100000000010000000
SFM SSF
01000000000100000000010000000001000000000100000000010000000001000000000100000000
TDD frame configuration 6-DSUUU DSUUD SFM DL
10000100011000010001100001000110000100011000010001100001000110000100011000010001
SFM UL
00111001100011100110001110011000111001100011100110001110011000111001100011100110
SFM SSF
01000010000100001000010000100001000010000100001000010000100001000010000100001000
6.4.3.3 Calculation of Subframe Collision Probabilities The probabilities of collision of subframes between a studied cell TXi(ic) and any interfering cell TXj(jc) are calculated as follows.
•
In the following equations, the operator
X
implies the sum of 1’s in a given
1
•
series of bits, X. In the following equations, AND and OR are logical bit-by-bit operators.
Method 1: ABS Patterns Used Only at Cell Edges By default, ABS patterns are considered only to be used for serving users at cell edges. This means that all subframes are considered non-ABS subframes in the cell centre. This is equivalent to setting the following Atoll.ini option: [LTE] UseABSonCellEdgeOnly = 1 Different collision probabilities are calculated depending on the location of the served pixel, subscriber, or mobile in cell TXi(ic): •
Subframe collision between cell centre of TXi(ic) and cell centre of TXj(jc):
TX i ic – TX j jc
p ABS – DL – CC
TX jc TX jc j j OR SFMSSF AND SFM DL 1 = -----------------------------------------------------------------------------------------------------------------------------------------------------------------------TX ic TX i ic SFM i OR SFM SSF DL TX ic i
SFMDL
TX ic i
OR SFM SSF
1
TX i ic – TX j jc
p ABS – UL – CC
j AND SFM j OR SFMSSF UL 1 = -----------------------------------------------------------------------------------------------------------------------------------------------------------------------TX i ic TX i ic SFM OR SFM UL SSF TX i ic
SFMUL
TX i ic
OR SFM SSF
TX jc
TX jc
1
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•
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Subframe collision between cell edge of TXi(ic) and cell centre of TXj(jc):
TX ic – TX jc i j
p ABS – DL – CC
TX jc TX jc j j AND SFM DL OR SFM SSF 1 = -------------------------------------------------------------------------------------------------------------------------------------------------------------------TX ic TX ic i SFP i OR SFPSSF DL TX ic i
SFPDL
TX ic i
OR SFPSSF
1
TX i ic – TX j jc
p ABS – UL – CC
TX jc TX jc j j OR SFM SSF AND SFM UL 1 = -------------------------------------------------------------------------------------------------------------------------------------------------------------------TX ic TX i ic SFP i OR SFPSSF UL TX ic i
SFPUL
TX ic i
OR SFPSSF
1
•
Subframe collision between cell centre of TXi(ic) and cell edge of TXj(jc):
TX i ic – TX j jc
p ABS – DL – CE
j j OR SFP SSF AND SFP DL 1 = -------------------------------------------------------------------------------------------------------------------------------------------------------------------TX i ic TX i ic SFM OR SFMSSF DL TX ic i
SFMDL
TX ic i
TX jc
OR SFM SSF
TX jc
1
TX i ic – TX j jc
p ABS – UL – CE
j AND SFP j OR SFP SSF UL 1 = -------------------------------------------------------------------------------------------------------------------------------------------------------------------TX ic TX ic i SFM i OR SFMSSF UL TX i ic
SFMUL
TX i ic
TX jc
OR SFM SSF
TX jc
1
•
Subframe collision between cell edge of TXi(ic) and cell edge of TXj(jc):
TX i ic – TX j jc
p ABS – DL – CE
TX i ic TX i ic TX j jc TX j jc OR SFPSSF AND SFP DL OR SFP SSF SFP DL 1 = ---------------------------------------------------------------------------------------------------------------------------------------------------------------TX i ic TX i ic SFP OR SFP DL SSF
1
TX i ic – TX j jc
p ABS – UL – CE
j AND SFP j OR SFP SSF UL 1 = ---------------------------------------------------------------------------------------------------------------------------------------------------------------TX ic TX i ic SFP i OR SFP SSF UL TX i ic
SFPUL
TX i ic
TX jc
OR SFPSSF
TX jc
1
This method enables you to include the cell-edge traffic ratio in the calculation of interference. The downlink interference reduction factor due to subframe collisions for any served pixel, subscriber, or mobile in cell TXi(ic) is calculated as follows: TX i ic – TX j jc
f ABS – DL
TX jc
TX ic – TX jc
TX jc
TX ic – TX jc
j i j j i j = 10 Log r DL – CE p ABS – DL – CE + 1 – r DL – CE p ABS – DL – CC
The uplink interference reduction factor due to subframe collisions for any served pixel, subscriber, or mobile in cell TXi(ic) is calculated as follows: TX i ic – TX j jc
f ABS – UL
TX ic – TX jc
TX ic – TX j jc
i j i = 10 Log p ABS – UL – CE or f ABS – UL
TX ic – TX jc
i j = 10 Log p ABS – UL – CC
Method 2: ABS Patterns Used Throughout the Cell If you wish to apply the ABS patterns throughout the cell, irrespective of the cell-edge area and the cell-edge traffic ratio, you can do so by adding the following lines in the Atoll.ini file: [LTE] UseABSonCellEdgeOnly = 0 The following collision probabilities are calculated between cells TXi(ic) and TXj(jc):
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TX ic – TX jc i j
p ABS – DL
TX jc TX jc j j OR SFPSSF AND SFP DL 1 = ---------------------------------------------------------------------------------------------------------------------------------------------------------------TX ic TX ic i SFP i OR SFP SSF DL TX ic i
SFPDL
TX ic i
OR SFP SSF
1
TX i ic – TX j jc
p ABS – UL
j AND SFP j OR SFPSSF UL 1 = ---------------------------------------------------------------------------------------------------------------------------------------------------------------TX i ic TX i ic SFP OR SFP SSF UL TX i ic
SFPUL
TX i ic
OR SFP SSF
TX jc
TX jc
1
The downlink interference reduction factor due to subframe collisions for any pixel, subscriber, or mobile is calculated as follows: TX i ic – TX j jc
TX i ic – TX j jc
= 10 Log p ABS – DL
f ABS – DL
The uplink interference reduction factor due to subframe collisions for any pixel, subscriber, or mobile is calculated as follows: TX i ic – TX j jc
TX i ic – TX j jc
= 10 Log p ABS – UL
f ABS – UL
6.4.4 Signal Level and Signal Quality Calculations These calculations include the calculation of the received signal levels, and noise and interference. The following sections describe how the received signal levels, the noise and interference, C/N, and C/(I+N) ratios are calculated in Atoll: • • • • • • • • • • •
"Signal Level Calculation (DL)" on page 453. "Noise Calculation (DL)" on page 505. "Interference Calculation (DL)" on page 505. "C/N Calculation (DL)" on page 516. "C/(I+N) and Bearer Calculation (DL)" on page 518. "Signal Level Calculation (UL)" on page 523. "Noise Calculation (UL)" on page 525. "Interference Calculation (UL)" on page 525. "Noise Rise Calculation (UL)" on page 528. "C/N Calculation (UL)" on page 529. "C/(I+N) and Bearer Calculation (UL)" on page 532.
6.4.4.1 Signal Level Calculation (DL) Input TX i ic
•
P Max : Max power of the cell TXi(ic).
•
P DLRS : Transmission power of the downlink reference signals for cell TXi(ic) as calculated in "Downlink Transmission
TX ic i
Power Calculation" on page 485. •
TX ic i
P SS
: Transmission power of the SS for cell TXi(ic) as calculated in "Downlink Transmission Power Calculation" on
page 485. •
TX ic i
P PBCH : Transmission power of the PBCH for cell TXi(ic) as calculated in "Downlink Transmission Power Calculation" on page 485.
•
TX i ic
P PDCCH : Transmission power of the PDCCH for cell TXi(ic) as calculated in "Downlink Transmission Power Calculation" on page 485.
•
TX i ic
P PDSCH : Transmission power of the PDSCH for cell TXi(ic) as calculated in "Downlink Transmission Power Calculation" on page 485.
•
TX i ic
EPRE DLRS : Energy per resource element of the downlink reference signals for cell TXi(ic) as calculated in "Downlink Transmission Power Calculation" on page 485.
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TX ic i
•
EPRE SS
: Energy per resource element of the SS for cell TXi(ic) as calculated in "Downlink Transmission Power Calculation" on page 485.
•
EPRE PBCH : Energy per resource element of the PBCH for cell TXi(ic) as calculated in "Downlink Transmission Power
TX ic i
Calculation" on page 485. •
TX i ic
EPRE PDCCH : Energy per resource element of the PDCCH for cell TXi(ic) as calculated in "Downlink Transmission Power Calculation" on page 485.
•
TX i ic
EPRE PDSCH : Energy per resource element of the PDSCH for cell TXi(ic) as calculated in "Downlink Transmission Power Calculation" on page 485. TX i
•
E SA : Number of antenna elements defined for the smart antenna equipment used by the transmitter TXi.
•
G SA
•
G SA
•
Div G SA
Array
: Smart antenna array gain offset defined per clutter class.
Combining
: Smart power combining gain offset defined per clutter class.
: Smart antenna diversity gain (for cross-polarised smart antennas) defined per clutter class.
TX i
•
G Ant : Transmitter antenna gain for the antenna used by the transmitter TXi.
•
G SA : Smart antenna gain in the direction of the served pixel, subscriber, or mobile Mi. For more information on
TX i
TX i
the calculation of G SA , see "Beamforming Smart Antenna Models" on page 43. TX i
Array
The smart antenna gain ( G SA ) and the smart antenna array gain offset ( G SA
) are
applied only if the AAS criterion (RS C/N, RS C/(I+N), or PDSCH C/(I+N)) is less than the DL
AAS threshold ( T AAS ) defined in the properties of the reception equipment used by the pixel, subscriber, or mobile Mi. TX i
: Total transmitter losses for the transmitter TXi ( L
TX i
= L Total – DL ).
•
L
•
L Model : Loss on the transmitter-receiver path (path loss) calculated using a propagation model.
•
L Ant : Antenna attenuation (from antenna patterns) calculated for the antenna used by the transmitter TXi.
•
M Shadowing – Model : Shadowing margin based on the model standard deviation.
TX i
In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. •
L Indoor : Indoor losses taken into account when the option "Indoor coverage" is selected.
•
L
• •
M
G
i
M
M
: Receiver terminal losses for the pixel, subscriber, or mobile Mi. i
: Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi.
i
L Ant : Receiver terminal’s antenna attenuation calculated for the pixel, subscriber, or mobile Mi. Mi
For calculating the useful signal level from the best serving cell, L Ant is determined in the direction (H,V) = (0,0) from Mi
the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, L Ant is determined in the direction of the interfering cell from the antenna patterns of the antenna used by Mi, while the antenna is pointed towards Mi’s best serving cell. •
Mi
L Body : Body loss defined for the service used by the pixel, subscriber, or mobile Mi.
L
Mi
, G
Mi
Mi
Mi
, L Ant , and L Body are not used in the calculations performed for the point
analysis tool’s profile tab, delta path loss calculation, and the downlink reference signal level based coverage predictions.
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•
TX ic i
D CP
: Cyclic prefix duration defined in the TXi(ic) frame configuration or, otherwise, in the global network settings.
Calculations The received signal levels (dBm) from any cell TXi(ic) are calculated for a pixel, subscriber, or mobile Mi as follows: TX i ic
C Max
TX i ic
= EIRP Max – L Path – M Shadowing – Model – L Indoor + G TX i ic
Without smart antennas: EIRP Max TX i ic
With smart antennas: EIRP Max TX i ic
TX i ic
Mi
TX i
= P Max + G Ant – L TX i ic
TX i
= P Max + G Ant – L
TX i
TX i ic
C DLRS = EIRP1 DLRS – L Path – M Shadowing – Model – L Indoor + G TX i ic
Without smart antennas: EIRP1 DLRS TX i ic
With smart antennas: EIRP1 DLRS TX ic i
C SS
TX ic i
= EIRP1 SS
TX i ic
TX i
TX i ic
TX i ic
TX i ic
= P SS
TX i ic
= P SS
TX i
M
–L
TX i ic
TX i ic
TX ic i
TX ic i
i
TX i ic
TX i ic
C PDCCH = EIRP1 PDCCH – L Path – M Shadowing – Model – L Indoor + G TX i ic
TX i ic
i
TX i ic
TX i ic
–L
TX i ic
TX i ic
C PDSCH = EIRP1 PDSCH – L Path – M Shadowing – Model – L Indoor + G TX i ic
TX i ic
Mi
TX i ic
i
Mi
Mi
Combining
Div
+ G SA
Mi
– L Ant – L Body + f CP
TX
i Combining Div + 10 Log E SA + G SA + G SA
–L
Mi
Mi
Mi
– L Ant – L Body + f CP
TX i
TX i
+ 10 Log E SA + G SA –L
TX i
Without smart antennas: EIRP1 PDSCH = P PDSCH + G Ant – L TX i ic
M
i
TX i
Mi
TX i
M
– L Ant – L Body + f CP
TX i
TX i
TX i
i
TX i
Without smart antennas: EIRP1 PDCCH = P PDCCH + G Ant – L With smart antennas: EIRP1 PDCCH = P PDCCH + G Ant – L
M
Combining
+ 10 Log E SA + G SA
Mi
TX
Mi
TX i
–L
TX i
TX
Mi
– L Ant – L Body + f CP
TX i
Without smart antennas: EIRP1 PBCH = P PBCH + G Ant – L With smart antennas: EIRP1 PBCH = P PBCH + G Ant – L
Mi
+ 10 Log E SA + G SA
i
TX i
C PBCH = EIRP1 PBCH – L Path – M Shadowing – Model – L Indoor + G TX i ic
Mi
TX i
TX i
Mi
TX
+ G Ant – L
+ G Ant – L
Mi
– L Ant – L Body + f CP
i Combining Div + 10 Log E SA + G SA + G SA
TX i
= P DLRS + G Ant – L
Without smart antennas: EIRP1 SS
TX i ic
TX i ic
Mi
TX i
= P DLRS + G Ant – L
– L Path – M Shadowing – Model – L Indoor + G
With smart antennas: EIRP1 SS
–L
Mi
Mi
Combining
Div
+ G SA
Mi
– L Ant – L Body + f CP
TX i
TX i
Array
With smart antennas: EIRP1 PDSCH = P PDSCH + G SA + G SA
Combining
+ G SA
Div
+ G SA – L
TX i
The energy per resource element (dBm/Sym) received from any cell TXi(ic) are calculated for a pixel, subscriber, or mobile Mi as follows: TX i ic
RSRP: E DLRS
TX i ic
= EIRP2 DLRS – L Path – M Shadowing – Model – L Indoor + G TX i ic
Without smart antennas: EIRP2 DLRS TX ic i
With smart antennas: EIRP2 DLRS
TX i ic
TX i
Mi
= EPRE DLRS + G Ant – L TX ic i
TX
i
= EPRE DLRS + G Ant – L
TX
i
–L
Mi
Mi
Mi
– L Ant – L Body + f CP
TX i
TX
i Combining + 10 Log E SA + G SA
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks TX ic i
E SS
TX ic i
= EIRP2 SS
©Forsk 2015
– L Path – M Shadowing – Model – L Indoor + G TX ic i
Without smart antennas: EIRP2 SS
TX ic i
With smart antennas: EIRP2 SS TX i ic
TX ic i
= EPRE SS
TX ic i
–L
TX
M
i
i
+ G Ant – L
TX i ic
E PBCH = EIRP2 PBCH – L Path – M Shadowing – Model – L Indoor + G TX i ic
i
+ G Ant – L TX
= EPRE SS
M
Mi
TX i ic
TX
–L
TX ic i
TX ic i
i
TX i ic
TX i ic
E PDCCH = EIRP2 PDCCH – L Path – M Shadowing – Model – L Indoor + G TX ic i
TX ic i
Mi
TX i ic
TX i ic
TX i ic
TX i ic
E PDSCH = EIRP2 PDSCH – L Path – M Shadowing – Model – L Indoor + G TX i ic
TX i ic
Mi
TX i
TX i ic
TX i
Mi
Mi
Mi
– L Ant – L Body + f CP
TX
i
TX i
+ 10 Log E SA + G SA
Mi
Without smart antennas: EIRP2 PDSCH = EPRE PDSCH + G Ant – L TX i ic
Div
+ G SA
– L Ant – L Body + f CP
Mi
TX i
–L
Combining
TX
i
TX i
Mi
i
TX i
Without smart antennas: EIRP2 PDCCH = EPRE PDCCH + G Ant – L With smart antennas: EIRP2 PDCCH = EPRE PDCCH + G Ant – L
i
i Combining Div + 10 Log E SA + G SA + G SA
i
–L
TX
TX
Mi
TX
i
TX
TX i
TX
M
i
– L Ant – L Body + f CP
+ 10 Log E SA + G SA
i
Without smart antennas: EIRP2 PBCH = EPRE PBCH + G Ant – L With smart antennas: EIRP2 PBCH = EPRE PBCH + G Ant – L
M
i
Mi
Combining
Div
+ G SA
Mi
– L Ant – L Body + f CP
TX i
Array
With smart antennas: EIRP2 PDSCH = EPRE PDSCH + G SA + G SA
Combining
+ G SA
Div
+ G SA – L
TX i
In the above, L Path is the path loss (dB) calculated as follows: TX i
L Path = L Model + L Ant Furthermore, the total losses between the cell and the pixel, subscriber, or mobile Mi can be calculated as follows: L Total = L Path + L
TX
i
+ L Indoor + M Shadowing – Model – G
TX
i
+L
M
i
–G
M
i
M
i
M
i
+ L Ant + L Body
f CP is the cyclic prefix factor, i.e., the ratio of the useful symbol energy to the total symbol energy. The total symbol duration of a modulation symbol comprises the useful symbol duration, carrying the actual data bits, and a cyclic prefix, added to the useful data bits as padding against multi-path to avoid inter-symbol interference. Hence, the total energy within a modulation symbol belongs in part to the useful data bits and in part to the cyclic prefix. Once a modulation symbol is received, only the energy of the useful data bits can be used for extracting the data. The energy belonging to the cyclic prefix is lost once it has served its purpose of combatting inter-symbol interference. Therefore, f CP implies that the energy belonging to the cyclic prefix is excluded from the useful signal level.
f CP
TX ic 10 Log 7 7.5 If D CPi = Normal TX i ic = = Extended 10 Log 6 7.5 If D CP 0 If TX ic is an interferer i
The cyclic prefix energy and the useful data bits energy are both taken into account when calculating interfering signal levels. Output
504
TX i ic
•
C Max : Received max signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
C DLRS : Received downlink reference signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
C SS
TX i ic TX i ic
: Received SS signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1 TX ic i
•
C PBCH : Received PBCH signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
C PDCCH : Received PDCCH signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
C PDSCH : Received PDSCH signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
E DLRS : Received downlink reference signal energy per resource element from the cell TXi(ic) at the pixel, subscriber,
TX ic i TX ic i
TX i ic
or mobile Mi. •
TX i ic
E SS
: Received SS energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
TX i ic
•
E PBCH : Received PBCH energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
E PDCCH : Received PDCCH energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
E PDSCH : Received PDSCH eneregy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
L Path : Path loss between the cell TXi(ic) and the pixel, subscriber, or mobile Mi.
•
L Total : Total losses between the cell TXi(ic) and the pixel, subscriber, or mobile Mi.
TX i ic TX ic i
6.4.4.2 Noise Calculation (DL) For determining the C/N and C/(I+N), Atoll calculates the downlink noise which comprises thermal noise and the noise figure of the equipment. The thermal noise density depends on the temperature, i.e., it remains constant for a given temperature. However, the value of the thermal noise varies with the used bandwidth. Input • • •
K: Boltzmann’s constant. T: Temperature in Kelvin. F : Subcarrier width (15 kHz).
•
nf
Mi
: Noise figure of the terminal used for calculations by the pixel, subscriber, or mobile Mi.
Calculations The power spectral density of thermal noise is calculated as follows: n 0 = 10 Log K T 1000 = – 174 dBm/Hz The thermal noise for one resource element, i.e., over one subcarrier, is calculated as follows: TX i ic
n 0 – Sym = n 0 + 10 Log F The downlink noise is the sum of the thermal noise and the noise figure of the terminal used for the calculations by the pixel, subscriber, or mobile Mi. The downlink noise for one resource element, i.e., over one subcarrier, is calculated as follows: TX i ic
n Sym
TX i ic
= n 0 – Sym + nf
Mi
Output •
TX i ic
n Sym
: Downlink noise for one subcarrier.
6.4.4.3 Interference Calculation (DL) The interference received by any pixel, subscriber, or mobile, served by a cell TXi(ic) from other cells TXj(jc) can be defined as the signal levels received from interfering cells TXj(jc) depending on the overlap that exists between the channels used by the cells TXi(ic) and TXj(jc), on the traffic loads of the interfering cells TXj(jc), and whether the cells support ICIC or not. Input •
TX jc j
E DLRS : Received downlink reference energy per resource element received from any interfering cell TXj(jc) as calculated in "Signal Level Calculation (DL)" on page 501 at the pixel, subscriber, or mobile Mi covered by the cell TXi(ic).
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•
TX jc j
E SS
©Forsk 2015
: Received SS energy per resource element received from any interfering cell TXj(jc) as calculated in "Signal
Level Calculation (DL)" on page 501 at the pixel, subscriber, or mobile Mi covered by the cell TXi(ic). •
TX jc j
E PBCH : Received PBCH energy per resource element received from any interfering cell TXj(jc) as calculated in "Signal Level Calculation (DL)" on page 501 at the pixel, subscriber, or mobile Mi covered by the cell TXi(ic).
•
TX j jc
E PDCCH : Received PDCCH energy per resource element received from any interfering cell TXj(jc) as calculated in "Signal Level Calculation (DL)" on page 501 at the pixel, subscriber, or mobile Mi covered by the cell TXi(ic).
•
TX j jc
E PDSCH : Received PDSCH energy per resource element received from any interfering cell TXj(jc) as calculated in "Signal Level Calculation (DL)" on page 501 at the pixel, subscriber, or mobile Mi covered by the cell TXi(ic).
•
TX j
G SA : Smart antenna gain in the direction . For more information, see "Beamforming Smart Antenna Models" on page 43.
•
TX j
G SA : Smart antenna gain in the direction calculated from the average array correlation matrix: H
G SA = g n S R Avg S . For more information, see "Beamforming Smart Antenna Models" on page 43. •
M Shadowing – Model : Shadowing margin based on the model standard deviation.
•
M Shadowing – C I : Shadowing margin based on the C/I standard deviation. In Monte Carlo simulations, the received energies per resource element from interferers already include M Shadowing – Model , as explained in "Signal Level Calculation (DL)" on page 501. In coverage predictions, the ratio M Shadowing – Model – M Shadowing – C I is applied to the interfering signals (for more information, see "Shadow Fading Model" on page 90). As the received energies per resource element from interferers already include M Shadowing – Model , M Shadowing – C I is added to the received energies per resource element from interferers in order to achieve the ratio M Shadowing – Model – M Shadowing – C I : E
TX jc j
= E
TX jc j
+ M Shadowing – C I
In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. TX j jc
•
N Sym – DLRS : Number of downlink reference signal resource elements as calculated in "Downlink Transmission Power
•
Calculation" on page 485. N Sym – SS : Number of SS resource elements as calculated in "Downlink Transmission Power Calculation" on page 485.
•
N Sym – PBCH : Number of PBCH resource elements as calculated in "Downlink Transmission Power Calculation" on
TX j jc
page 485. •
TX j jc
N Sym – PDCCH : Number of PDCCH resource elements as calculated in "Downlink Transmission Power Calculation" on page 485.
•
TX j jc
N Sym – PDSCH : Number of PDSCH resource elements as calculated in "Downlink Transmission Power Calculation" on page 485.
•
TX j jc
N Sym – DL : Total number of downlink resource elements as calculated in "Downlink Transmission Power Calculation" on page 485.
•
TX i ic – TX j jc
rO
: Total channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Co- and Adjacent
Channel Overlaps Calculation" on page 493. •
TX j jc
TL DL
: Downlink traffic load of the interfering cell TXj(jc).
Traffic loads can either be calculated using Monte Carlo simulations, or entered manually for each cell. Calculation of traffic loads is explained in "Simulation Process" on page 479.
506
TX j jc
•
AU DL
: Downlink AAS usage of the interfering cell TXj(jc).
•
W FB : Width of a frequency block in the frequency domain (180 kHz).
•
N FB – SS PBCH : Number of frequency blocks that carry the SS and the PBCH (6).
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
•
TX ic i
N FB
TX jc j
and N FB
: Total number of frequency blocks defined in the frequency bands table for the channel
bandwidth used by the cell. •
TX ic i
TX jc j
N FB – CE0 and N FB – CE0 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell and PSS ID 0.
•
TX i ic
TX j jc
N FB – CE1 and N FB – CE1 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell and PSS ID 1.
•
TX i ic
TX j jc
N FB – CE2 and N FB – CE2 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell and PSS ID 2.
•
TX i ic
TX j jc
F Start and F Start : Start frequencies of the channels assigned to the cells TXi(ic) and TXj(jc) calculated as explained in "Conversion From Channel Numbers to Start and End Frequencies" on page 494. TX i ic
TX j jc
•
W Channel and W Channel : Bandwidths of the channels assigned to cells TXi(ic) and TXj(jc).
•
ID
•
r DL – CE and r DL – CE : Downlink cell-edge traffic ratios of the cells TXi(ic) and TXj(jc).
•
N Ant – TX : Number of transmission (downlink) antenna ports defined for the cell TXi(ic).
•
N Ant – TX : Number of transmission (downlink) antenna ports defined for the cell TXj(jc).
TX i ic
TX i ic
TX j jc
and ID
: Physical cell IDs of the cells TXi(ic) and TXj(jc).
TX j jc
TX i ic
TX jc j
Calculations Two interference calculation methods exist in Atoll.
•
TX j jc
TX j jc
Calculations of f MIMO , f TL
TX i ic – TX j jc
, f ICIC – DL
TX i ic – TX j jc
, f PDCCH
TX i ic – TX j jc
, and f PDSCH
are
explained at the end of this section. •
TX j jc
In the calculations below, E DLRS TX i ic – TX j jc
probability f ABS – DL
is weighted by the downlink subframe collision
when the relevant option is set in the Atoll.ini file:
[LTE] eICIConRS = 1 Method 1: Synchronised Transmission and Reception Atoll calculates the interference between two cells using this method when: • •
The frequency channels assigned to the interfered and interfering cells have the same centre frequency, and The interfered and interfering cells both have an even number of frequency blocks or both have an odd number of frequency blocks, and • The Atoll.ini file does not contain the following option: [LTE] SameItf_PDSCH_RS_PDCCH = 1 Synchronised transmission and reception means that the OFDM symbols of the interfered and interfering frames overlap and match each other in time. The interfering energy per resource element (dBm/Sym) received over downlink reference signals from any cell TXj(jc) at a pixel, subscriber, or mobile Mi is calculated as follows: •
RS of the interfered cell TXi(ic) collide only with RS of the interfering cell TXj(jc) TX i ic
This occurs when ID PSS
TX j jc
= ID PSS
TX j jc
TX i ic
and N Ant – TX N Ant – TX
For the calculation of the probability of collision, here N Ant – TX = Min 4 NAnt – TX .
507
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
©Forsk 2015 TX jc
TX jc j
DLRS
•
j TX ic E DLRS N i --------------------- TX ic – TX jc 10 j Ant – TX +f i = 10 Log ------------------ 10 O TX jc j N Ant – TX
RS of the interfered cell TXi(ic) collide with RS, PDCCH, and PDSCH of the interfering cell TXj(jc) TX i ic
This occurs when ID PSS
TX j jc
= ID PSS
TX j jc
TX i ic
and N Ant – TX N Ant – TX
For the calculation of the probability of collision, here N Ant – TX = Min 4 N Ant – TX .
With 1 or 2 antenna ports: TX jc
TX j jc
DLRS
j TX jc E DLRS N j --------------------- TX i ic – TX j jc 10 Ant – TX = 10 Log ------------------ 10 TX i ic + fO N Ant – TX TX jc
TX ic – TX jc
TX jc
TX ic – TX jc
TX jc
TX ic – TX jc
TX jc
TX ic – TX jc
j i j j i j E PDCCH + f PDCCH E PDSCH + f PDSCH TX j jc --------------------------------------------------------------------------------------------------------------------------------------------- TXi ic 10 10 N Ant – TX – N Ant – TX 10 + 3 10 ------------------------------------------------------------------------------------------------------------------------------------ + 10 L og --------------------------------------------TX i ic 4 N Ant – TX TX ic i
With 4 or 8 antenna ports and N SD – PDCCH = 1 : TX jc
TX j jc
DLRS
j TX jc E DLRS N j --------------------- TX i ic – TX j jc 10 Ant – TX = 10 Log ------------------ 10 + fO TXi ic N Ant – TX TX jc
TX ic – TX jc
j i j j i j E PDCCH + f PDCCH E PDSCH + f PDSCH TX j jc --------------------------------------------------------------------------------------------------------------------------------------------- TXi ic 10 10 N Ant – TX – N Ant – TX 10 + 5 10 ------------------------------------------------------------------------------------------------------------------------------------ + 10 L og --------------------------------------------TX i ic 6 N Ant – TX TX i ic
With 4 or 8 antenna ports and N SD – PDCCH 1 : TX jc
TX j jc
DLRS
j TX jc E DLRS N j --------------------- TX i ic – TX j jc 10 Ant – TX = 10 Log ------------------ 10 TX i ic + fO N Ant – TX TX jc
TX ic – TX jc
i j i j j j E PDCCH + f PDCCH E PDSCH + f PDSCH TX j jc --------------------------------------------------------------------------------------------------------------------------------------------- TXi ic 10 10 N Ant – TX – N Ant – TX 10 + 2 10 ------------------------------------------------------------------------------------------------------------------------------------ + 10 L og --------------------------------------------TX i ic 3 N Ant – TX
•
RS of the interfered cell TXi(ic) collide only with PDCCH and PDSCH of the interfering cell TXj(jc) This
occurs
TX i ic
ID PSS
when
TX j jc
ID PSS
With 1 or 2 antenna ports:
508
TX i ic
( ID PSS
TX j jc
= ID PSS
and
TX i ic
Shift
TX j jc
= Shift 3
and
TX i ic
TX j jc
N Ant – TX = N Ant – TX = 1 )
OR
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1 TX jc
TX jc j
DLRS
TX ic – TX jc
TX jc
TX ic – TX jc
TX jc
TX ic – TX jc
TX jc
TX ic – TX jc
j i j j i j EPDCCH +f E +f PDCCH PDSCH PDSCH ----------------------------------------------------------------------- ----------------------------------------------------------------------10 10 TX ic – TX jc 10 + 3 10 i j = 10 Log ------------------------------------------------------------------------------------------------------------------------------------ + f O 4 TX i ic
With 4 or 8 antenna ports and N SD – PDCCH = 1 : TX jc
TX j jc
DLRS
TX ic – TX jc
j i j j i j EPDCCH + f PDCCH E PDSCH + f PDSCH ----------------------------------------------------------------------- ----------------------------------------------------------------------10 10 TX i ic – TX j jc 10 + 5 10 = 10 Log ------------------------------------------------------------------------------------------------------------------------------------ + f O 6 TX i ic
With 4 or 8 antenna ports and N SD – PDCCH 1 : TX jc
TX j jc
DLRS
TX ic – TX jc
j i j j i j EPDCCH + f PDCCH E PDSCH + f PDSCH ----------------------------------------------------------------------- ----------------------------------------------------------------------10 10 TX i ic – TX j jc 10 + 2 10 = 10 Log ------------------------------------------------------------------------------------------------------------------------------------ + f O 3
The interfering energy per resource element (dBm/Sym) received over the SS and the PBCH from any cell TXj(jc) at a pixel, subscriber, or mobile Mi is calculated as follows: TX jc j
TX j jc
SS PBCH
TX jc j
E PBCH ESS --------------------TX j jc ------------------- 10 10 TX ic – TX j jc TX j jc 10 N Sym – SS + 10 N Sym – PBCH - + f O i = 10 Log ------------------------------------------------------------------------------------------------------------+ f MIMO TX j jc N Sym – SS + N Sym – PBCH
The interfering energy per resource element (dBm/Sym) received over the PDCCH from any cell TXj(jc) at a pixel, subscriber, or mobile Mi is calculated as follows: •
PDCCH of the interfered cell TXi(ic) collides with PDCCH and all the RS of the interfering cell TXj(jc) This
occurs
TX ic i ID PSS
when
TX ic i
( ID PSS
TX jc j
= ID PSS
and
TX ic i
Shift
TX jc j
= Shift 3
and
TX ic i
TX jc j
N Ant – TX = N Ant – TX = 1 )
OR
TX jc j ID PSS
For the calculation of the probability of collision, here N Ant – TX = Min 4 NAnt – TX .
TX jc
TX j jc
PDCCH
j E TX j jc DLRS -------------------TX ic – TX j jc N 1 10 Sym – DLRS in PDCCH +f i - 10 = 10 Log ------------------ ----------------------------------------O TX jc TX ic j i N Ant – TX N Sym – PDCCH TX jc
TX ic – TX jc
j i j TX ic E PDCCH + f PDCCH TX j jc N i ----------------------------------------------------------------------- – N 10 Sym – PDCCH Sym – DLRS in PDCCH - 10 + 10 L og ----------------------------------------------------------------------------TX i ic N Sym – PDCCH
Here, N Sym – DLRS in PDCCH is the number of downlink reference signal resource elements that fall within the PDCCH, and N Sym – PDCCH is the number of PDCCH resource elements per frame. •
PDCCH of the interfered cell TXi(ic) collides with PDCCH and some RS of the interfering cell TXj(jc) TX i ic
This occurs when ID PSS
TX j jc
= ID PSS
TX j jc
TX i ic
and N Ant – TX N Ant – TX
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
©Forsk 2015
For the calculation of the probability of collision, here N Ant – TX = Min 4 N Ant – TX .
TX jc
TX j jc
PDCCH
j TX ic E DLRS TX j jc TX i ic N i -------------------- TX ic – TX j jc N Sym – DLRS in PDCCH – N Sym – DLRS in PDCCH Ant – TX - 10 10 + f O i = 10 Log ------------------ -----------------------------------------------------------------------------------------TX jc TX ic j i N Sym – PDCCH N Ant – TX TX jc
TX ic – TX jc
j i j TX jc E PDCCH + f PDCCH N j ----------------------------------------------------------------------- 10 Sym – PDCCH 10 + 10 L og ---------------------------- TXi ic N Sym – PDCCH
Here, N Sym – DLRS in PDCCH is the number of downlink reference signal resource elements that fall within the PDCCH, and N Sym – PDCCH is the number of PDCCH resource elements per frame. •
PDCCH of the interfered cell TXi(ic) collides only with PDCCH of the interfering cell TXj(jc) TX i ic
This occurs when ID PSS TX j jc
TX j jc
TX j jc
= ID PSS
TX i ic – TX j jc
PDCCH = E PDCCH + f PDCCH
TX j jc
TX i ic
and N Ant – TX N Ant – TX
TX i ic – TX j jc
+ fO
The interfering energy per resource element (dBm/Sym) received over the PDSCH from any cell TXj(jc) at a pixel, subscriber, or mobile Mi is calculated as follows: •
PDSCH of the interfered cell TXi(ic) collides with PDSCH and all the RS of the interfering cell TXj(jc) This
occurs
TX i ic
ID PSS
when
TX ic i
( ID PSS
TX jc j
= ID PSS
and
TX ic i
Shift
TX jc j
= Shift 3
and
TX ic i
TX jc j
N Ant – TX = N Ant – TX = 1 )
OR
TX j jc
ID PSS
For the calculation of the probability of collision, here N Ant – TX = Min 4 N Ant – TX .
TX jc
TX j jc
PDSCH
j E TX jc DLRS - j -------------------TX i ic – TX j jc N 1 10 Sym – DLRS in PDSCH - 10 = 10 Log ------------------+ fO ----------------------------------------TX i ic TXj jc N Ant – TX N Sym – PDSCH TX jc
TX ic – TX jc
j i j TX ic E +f TX j jc PDSCH PDSCH N i ----------------------------------------------------------------------- – N 10 Sym – PDSCH Sym – DLRS in PDSCH 10 + 10 L og ----------------------------------------------------------------------------TX i ic N Sym – PDSCH
Here, N Sym – DLRS in PDSCH is the number of downlink reference signal resource elements that fall within the PDSCH, and N Sym – PDSCH is the number of PDSCH resource elements per frame. •
PDSCH of the interfered cell TXi(ic) collides with PDSCH and some RS of the interfering cell TXj(jc) TX i ic
This occurs when ID PSS
TX j jc
= ID PSS
TX j jc
TX i ic
and N Ant – TX N Ant – TX
For the calculation of the probability of collision, here N Ant – TX = Min 4 N Ant – TX .
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
TX jc
TX jc j
PDSCH
j TX ic E TX jc TX ic DLRS j i N i --------------------- TX ic – TX jc N – N 10 j Ant – TX Sym – DLRS in PDSCH Sym – DLRS in PDSCH +f i - 10 ----------------------------------------------------------------------------------------= 10 Log ------------------O TX jc TX ic j i N Ant – TX N Sym – PDSCH TX jc
TX ic – TX jc
j i j TX jc E PDSCH + f PDSCH N j ----------------------------------------------------------------------- 10 Sym – PDSCH - 10 + 10 L og ---------------------------TX i ic N Sym – PDSCH
Here, N Sym – DLRS in PDSCH is the number of downlink reference signal resource elements that fall within the PDSCH, and N Sym – PDSCH is the number of PDSCH resource elements per frame. •
PDSCH of the interfered cell TXi(ic) collides only with PDSCH of the interfering cell TXj(jc) TX i ic
TX j jc
= ID PSS
This occurs when ID PSS TX j jc
TX j jc
TX i ic – TX j jc
PDSCH = E PDSCH + f PDSCH
TX j jc
TX i ic
and N Ant – TX N Ant – TX
TX i ic – TX j jc
+ fO
Method 2: Non-synchronised Transmission and Reception Atoll calculates the interference between two cells using this method when: • •
The frequency channels assigned to the interfered and interfering cells do not have the same centre frequency, or The interfered and interfering cells do not both have an even number of frequency blocks or do not both have an odd number of frequency blocks, or • The Atoll.ini file contains the following option: [LTE] SameItf_PDSCH_RS_PDCCH = 1 This method is also used for calculating the interference received from LTE cells of an external network in co-planning mode, i.e., inter-technology interference received from LTE cells calculated using the inter-technology IRFs. The interfering energy per resource element (dBm/Sym) received over downlink reference signals from any cell TXj(jc) at a pixel, subscriber, or mobile Mi is calculated as follows: TX jc
TX j jc
DLRS
TX jc
TX ic – TX jc
j i j E j E PDCCH + f PDCCH TX j jc TX jc DLRS ------------------------------------------------------------------------------------------ N j N 10 10 Sym – DLRS Sym – PDCCH - + 10 ------------------------ ----------------------------= 10 Log 10 TX j jc TX j jc N Sym – DL N Sym – DL
+ 10
TX j jc TX i ic – TX j jc E PDSCH + f PDSCH ----------------------------------------------------------------------10
TX j jc TX ic – TX j jc N Sym – PDSCH - + fO i ---------------------------TX j jc N Sym – DL
The interfering energy per resource element (dBm/Sym) received over the SS and the PBCH from any cell TXj(jc) at a pixel, subscriber, or mobile Mi is calculated as follows: TX j jc
TX j jc
SS PBCH
TX j jc
TX j jc
TX j jc
+ f MIMO E PBCH + f MIMO ESS ----------------------------------------------TX j jc --------------------------------------------- 10 10 TX ic – TX j jc N Sym – SS + 10 N Sym – PBCH 10 - + f O i = 10 Log --------------------------------------------------------------------------------------------------------------------------------------------------TX j jc N Sym – SS + N Sym – PBCH
The interfering energy per resource element (dBm/Sym) received over the PDSCH and the PDCCH from any cell TXj(jc) at a pixel, subscriber, or mobile Mi is calculated as follows:
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
©Forsk 2015 TX jc
TX jc
TX jc j
PDSCH
+ 10
TX jc TX ic – TX jc j i j E PDSCH + f PDSCH ----------------------------------------------------------------------10
TX j jc TX ic – TX j jc N Sym – PDSCH - + fO i ---------------------------TX j jc N Sym – DL
TX jc
TX j jc
TX ic – TX jc
j i j E j E +f TX jc TX jc DLRS PDCCH PDCCH j j -----------------------------------------------------------------------------------------N N Sym – PDCCH 10 10 Sym – DLRS - + 10 ----------------------------= 10 Log 10 ------------------------ TX jc TX jc j j N Sym – DL N Sym – DL
PDCCH
TX jc
TX ic – TX jc
j i j E j E PDCCH + f PDCCH TX j jc TX j jc DLRS -----------------------------------------------------------------------------------------N Sym – DLRS N Sym – PDCCH 10 10 ---------------------------------------------------- TX jc + 10 = 10 Log 10 TX j jc j N Sym – DL N Sym – DL
+ 10
TX j jc TX i ic – TX j jc E PDSCH + f PDSCH ----------------------------------------------------------------------10
TX j jc TX ic – TX j jc N Sym – PDSCH - + fO i ---------------------------TX j jc N Sym – DL
E-UTRA carrier RSSI is measured on the OFDM symbols that contain reference signals. Therefore, the interfering energy per frequency block (dBm/RB) received from any cell TXj(jc) at a pixel, subscriber, or mobile Mi over 1 frequency block during an OFDM symbol carrying reference signals, is given as follows: For cells using more than 1 antenna port, the encircled 10 in the formulas below is replaced with 8.
TX j jc
TX j jc
RSSI
TX i ic – TX j jc
EPDSCH + fPDSCH TX j jc ---------------------------------------------------------------------10 N Sym – PDSCH 10 10 = 10 Log --------------------------------------------------------------------------------------------TX j jc TX j jc N + N Sym – PDSCH Sym – PDCCH TX j jc TX i ic – TX j jc E +f PDCCH PDCCH ----------------------------------------------------------------------10
TX j jc
N Sym – PDCCH 10 - 10 + 10 + --------------------------------------------------------------------------------------------TX j jc TX j jc N Sym – PDSCH + N Sym – PDCCH
TX j jc E DLRS --------------------10
TX j jc TX i ic – TX j jc 2 Min 2 N Ant – TX + f O
Calculation of PDCCH and PDSCH Interference Weighting Factors TX i ic – TX j jc
The PDCCH and PDSCH interference weighting factors ( f PDCCH
TX i ic – TX j jc
f PDCCH
TX j jc TX j jc TX i ic – TX j jc TX i ic – TX j jc f MIMO + f TL + f ICIC – DL + f ABS – DL ------------------------------------------------------------------------------------------------------------------------------------------------- TX j jc 10 1 – AU 10 DL = TX jc TX ic – TX jc TX ic – TX jc j i j i j f TL + f ICIC – DL + f ABS – DL ----------------------------------------------------------------------------------------------------------------------TX j jc 10 10 + AU DL TX jc
TX i ic – TX j jc
f PDSCH
TX jc
TX ic – TX jc
TX ic – TX jc
j j i j i j f MIMO + f TL + f ICIC – DL + f ABS – DL ------------------------------------------------------------------------------------------------------------------------------------------------- TX j jc 10 1 – AU DL 10 = TX j TX i ic – TX j jc TX i ic – TX j jc TX j G – G + f + f SA SA ICIC – DL ABS – DL --------------------------------------------------------------------------------------------------------------------------------------------------------- TX j jc 10 + AU DL 10
Calculation of MIMO/Antenna Diversity Interference Factors
512
TX i ic – TX j jc
and f PDSCH
) are calculated as follows:
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1 TX jc
TX jc
TX jc
j j j f MIMO is the interference increment due to more than one transmission antenna port: f MIMO = 10 Log N Ant – TX TX jc j
If you do not wish to apply f MIMO , add the following lines in the Atoll.ini file: [LTE] MultiAntennaInterference = 0 MultiAntennaInterference is set to 1 by default. Calculation of Interference Reduction Factors TX jc j
Calculations for the interference reduction factors due to traffic load f TL TX i ic – TX j jc
downlink ICIC using fractional frequency reuse ( f ICIC – DL
TX ic – TX jc i j
, channel overlapping ( f O
), and static
) are explained below:
Interference reduction due to the traffic loads of the interfering cells: Interference reduction due to the traffic loads of the interfering cells TXj(jc) is calculated as follows: TX j jc
f TL
TX j jc
= 10 Log TL DL
Interference reduction due to the co- and adjacent channel overlap between the studied and the interfering cells: Interference reduction due to the co- and adjacent channel overlap between the cells TXi(ic) and TXj(jc) is calculated as follows: TX i ic – TX j jc
fO
TX i ic – TX j jc
= 10 Log r O
Interference reduction due to static downlink ICIC using fractional frequency reuse: The interference reduction factor due to static downlink ICIC using fractional frequency reuse for any pixel, subscriber, or mobile Mi is calculated as follows: TX i ic – TX j jc
f ICIC – DL
TX ic – TX j jc
i = 10 Log p Collision
Whether a pixel, subscriber, or mobile Mi is in cell centre or cell-edge is determined as explained in "Best Server Determination" on page 535. TX i ic – TX j jc
Depending on the ICIC mode defined for the frame configuration of the cells TXi(ic) and TXj(jc), f ICIC – DL calculated as follows: •
is
If both TXi(ic) and TXj(jc) use time-switched FFR The cell-edge and cell-centre resources are time-divided. Therefore, an interfered user may receive interference from the cell-edge and cell-centre parts of the frame depending on time-domain switching points between the cell-edge and cell-centre parts of the frames. Atoll determines the switching point between the ICIC and the non-ICIC parts of the frame using the ICIC ratios. The switching points between the ICIC and non-ICIC parts of the frame of the victim and interfering cells, TXi(ic) and TXj(jc) respectively, are calculated as follows: SP
TX ic i
TX i ic
TX j jc
TX jc r DL – CE r DL – CE j = ---------------------------------------------------------------------------- and SP = ---------------------------------------------------------------------------TX i ic TX j jc TX i ic TX i ic TX j jc TX j jc N N FB – CE FB – CE r DL – CE + 1 – r DL – CE ----------------r DL – CE + 1 – r DL – CE ----------------TX i ic TX j jc N FB N FB
Where, SP is the switching point between the ICIC and the non-ICIC parts of the frame, and r DL – CE is the downlink cell-edge traffic ratios of the cells.
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The ICIC ratio is used to partition the total downlink traffic load into ICIC and non-ICIC parts of the frame. Therefore, the switching point formula is derived from the equation: r DL – CE TL DL 1 – r DL – CE TL DL --------------------------------------------------------- = ---------------------------------------------- 1 – SP W Channel N FB – CE ----------------SP WChannel N FB With cells using static downlink ICIC, there can be four different interference scenarios. i.
Between the ICIC part of the victim and the ICIC part of the interferer.
ii. Between the ICIC part of the victim and the non-ICIC part of the interferer. iii. Between the non-ICIC part of the victim and the ICIC part of the interferer. iv. Between the non-ICIC part of the victim and the non-ICIC part of the interferer. Therefore, Atoll calculates the probabilities of collision for each scenario and weights the total interference according to the total collision probability. The probability of collision p Coll for each scenario is: Case
Interfered cell TX i ic
Interfering cell TX j jc
p Coll
i
ICIC
ICIC
N FB – CE --------------------TX i ic N FB – CE
ii
ICIC
Non ICIC
1
Common
Common
iii
Non ICIC
ICIC
N FB – CE --------------------TX i ic N FB
iv
Non ICIC
Non ICIC
1
Common
Where, N FB – CE
TX i ic
is the number of cell-edge frequency blocks common in TXi(ic) and TXj(jc), and N FB – CE is the
number of cell-edge frequency blocks in the cell TXi(ic). For a pixel, subscriber, or mobile Mi in the cell-edge of TXi(ic), the total collision probability for the pixel, subscriber, or mobile Mi is calculated as follows:
TX i ic – TX j jc
p Collision
TX j jc TX i ic i p Coll If SP SP TX jc TX ic TX jc = i ii j i j + p Coll SP – SP TX j jc TX i ic p Coll SP ------------------------------------------------------------------------------------------------------------ SP If SP TX i ic SP
For a pixel, subscriber, or mobile Mi in the cell centre of TXi(ic), the total collision probability for the pixel, subscriber, or mobile Mi is calculated as follows:
TX i ic – TX j jc
p Collision
•
TX j jc TX i ic iv p Coll If SP SP TX j jc TX jc TX ic + p iii SP j – SP i = p iv TX jc TX ic Coll 1 – SP Coll ---------------------------------------------------------------------------------------------------------------------------- If SP j SP i TX ic 1 – SP i
Other combinations of ICIC modes TX i ic – TX j jc
Separate probabilities of collisions, p Collision TX i ic – TX j jc
Cell centre: p Collision
514
Common
N FB – CC = -------------------TX i ic N FB – CC
, are calculated for cell-centre and cell-edge cases as follows:
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1 TX ic – TX jc i j
Cell-edge: p Collision
Common
Where, N FB – CC
Common
N FB – CE = -------------------TX ic i N FB – CE Common
is the number of common frequency blocks in TXi(ic) and TXj(jc) in cell centre, N FB – CE TX i ic
is the
TX i ic
number of common frequency blocks in TXi(ic) and TXj(jc) on cell-edge, N FB – CC and N FB – CE are respectively the numbers of frequency blocks in cell centre and cell-edge of TXi(ic). Number of frequency blocks in
ICIC mode
Cell centre
Cell edge
TX i ic
No FFR
N FB
Time-switched FFR
N FB
TX i ic
N FB
TX i ic
TX i ic
N FB – CEx
TX i ic
Hard FFR
TX i ic
N FB – CEx TX i ic
Soft FFR
N FB TX i ic
Partial soft FFR
N FB
TX ic
N FB – CEx
TX i ic
TX i ic
– N FB – CEx TX ic
N FB – CEx TX ic
i i i – N FB – CE0 + N FB – CE1 + N FB – CE2
TX i ic
TX i ic
TX i ic
TX i ic
N FB – CEx
TX i ic
Where N FB – CEx can be N FB – CE0 , N FB – CE1 , or N FB – CE2 depending on the PSS ID of TXi(ic). Interference reduction due to subframe collision probabilities: TX i ic – TX j jc
The interference reduction factor due to downlink subframe collision probabilities f ABS – DL
is calculated as
explained in "Subframe Pattern Collision Calculation" on page 497. Calculation of the Downlink Inter-technology Interference The downlink inter-technology interference is calculated as follows: Inter – Tech I DL
TX
TX k P DL – Rec --------------------------------------- = F TX ic TX i k TX k ICP DL
k
Here P DL – Rec is the received downlink power from an interfering cell TXk belonging to another technology, and F TX i ic TX k
ICPDL
is the inter-technology downlink channel protection ratio for a frequency offset F between the interfered
and interfering frequency channels of TXi(ic) and TXk. TX k
P DL – Rec is calculated based on the EIRP from GSM cells, total power from UMTS, CDMA2000, and TD-SCDMA cells, maximum power from LTE cells, preamble power from WiMAX cells, and downlink cell power from Wi-Fi cells. Output •
TX j jc
DLRS : Interfering energy per resource element (dBm/Sym) received over downlink reference signals from any cell TXj(jc) at a pixel, subscriber, or mobile Mi covered by a cell TXi(ic).
•
TX jc j
SS PBCH : Interfering energy per resource element (dBm/Sym) received over the SS and the PBCH from any cell TXj(jc) at a pixel, subscriber, or mobile Mi covered by a cell TXi(ic).
•
TX j jc
PDSCH : Interfering energy per resource element (dBm/Sym) received over the PDSCH from any cell TXj(jc) at a pixel, subscriber, or mobile Mi covered by a cell TXi(ic).
•
TX j jc
PDCCH : Interfering energy per resource element (dBm/Sym) received over the PDCCH from any cell TXj(jc) at a pixel, subscriber, or mobile Mi covered by a cell TXi(ic).
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TX jc j
RSSI : Interfering energy per frequency block (dBm/RB) received from any cell TXj(jc) at a pixel, subscriber, or mobile Mi over 1 frequency block during an OFDM symbol carrying reference signals.
•
Inter – Tech
I DL
: Downlink inter-technology interference.
6.4.4.4 C/N Calculation (DL) Input •
TX i ic
E DLRS : Received downlink reference signal energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Signal Level Calculation (DL)" on page 501.
•
TX i ic
E SS
: Received SS energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as
calculated in "Signal Level Calculation (DL)" on page 501. •
TX i ic
E PBCH : Received PBCH energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Signal Level Calculation (DL)" on page 501.
•
TX i ic
E PDCCH : Received PDCCH energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Signal Level Calculation (DL)" on page 501.
•
TX i ic
E PDSCH : Received PDSCH energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Signal Level Calculation (DL)" on page 501.
• •
TX ic i
n Sym
: Downlink noise for one subcarrier for the cell TXi(ic) as calculated in "Noise Calculation (DL)" on page 505.
TX i ic
CINR DLRS : Downlink reference signal C/(I+N) from cell TXi(ic) at pixel, subscriber, or mobile Mi as calculated in "C/ (I+N) and Bearer Calculation (DL)" on page 518. Mi
•
T SU – MIMO – DL : SU-MIMO threshold defined in the reception equipment used by Mi’s terminal.
•
T B : Bearer selection thresholds of the bearers defined in the reception equipment used by Mi’s terminal.
•
B DL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
Mi
Mi
or mobile Mi. •
Mi
B DL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber, or mobile Mi. TX i ic
•
N Ant – TX : Number of transmission (downlink) antenna ports defined for the cell TXi(ic).
•
N Ant – RX : Number of reception (downlink) antenna ports defined for the terminal used by the pixel, subscriber, or
Mi
mobile Mi. •
Mobility M i : Mobility used for the calculations.
•
i BLER BDL : Downlink block error rate read from the graphs available in the reception equipment assigned to the
M
terminal used by the pixel, subscriber, or mobile Mi. •
Mi
G Div – PBCH : PBCH diversity gain defined in the reception equipment of the terminal used by the pixel, subscriber, or mobile Mi.
•
Mi
G Div – PDCCH : PDCCH diversity gain defined in the reception equipment of the terminal used by the pixel, subscriber, or mobile Mi.
•
DL
G Div : Additional downlink diversity gain defined for the clutter class where the pixel, subscriber, or mobile Mi is located.
Calculations The C/N for cell TXi(ic) are calculated as follows for any pixel, subscriber, or mobile Mi: TX i ic
CNR DLRS
516
TX i ic
TX i ic
= E DLRS – n Sym
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AT330_TRR_E1 TX ic i
CNR SS
TX ic i
= E SS
TX ic i
– n Sym
TX ic i
TX ic i
TX ic i
TX ic i
TX ic i
TX ic i
TX i ic
TX i ic
TX i ic
CNR PBCH = E PBCH – n Sym
CNR PDCCH = E PDCCH – n Sym CNR PDSCH = E PDSCH – n Sym
Bearer Determination: The bearers available for selection in the pixel, subscriber, or mobile Mi’s reception equipment are the ones: •
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
•
Whose selection thresholds are less than the PDSCH C/N at Mi: T B CNR PDSCH
Mi
TX i ic
If the cell supports MIMO, and according to the Mi diversity mode depending on the SU-MIMO and MU-MIMO Mi
thresholds and criteria, transmit diversity, SU-MIMO diversity, or MU-MIMO diversity gain, G Div – DL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the TX i ic
Mi
reception equipment assigned to the pixel, subscriber, or mobile Mi for N Ant – TX , N Ant – RX , Mobility M i , M
i BLER B DL . DL
The additional downlink diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the reception equipment for which the following is true: M
i
M
i
TX ic i
DL
T B – G Div – DL – G Div CNR PDSCH The bearer selected for data transfer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic). •
Bearer Index From among the bearers available for selection, the selected bearer is the one with the highest index.
•
Peak RLC Throughput From among the bearers available for selection, the selected bearer is the one with the highest downlink peak RLC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation" on page 547.
•
Effective RLC Throughput From among the bearers available for selection, the selected bearer is the one with the highest downlink effective RLC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation" on page 547.
MIMO Diversity Gain: With MIMO, the PBCH and PDCCH C/N become: TX i ic
TX i ic
Mi
TX i ic
TX i ic
Mi
DL
CNR PBCH = CNR PBCH + G Div – PBCH + G Div DL
CNR PDCCH = CNR PDCCH + G Div – PDCCH + G Div The PBCH and PDCCH diversity gains are applied to the C/N when the cell and the terminal both support any form of MIMO in downlink. The additional downlink diversity gain defined per clutter is also applied. Once the bearer is known, the PDSCH C/N calculated above becomes: TX i ic
TX i ic
Mi
DL
CNR PDSCH = CNR PDSCH + G Div – DL + G Div
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i
Where G Div – DL is the transmit diversity, SU-MIMO diversity, or MU-MIMO diversity gain applied if the cell supports MIMO and depending on the Mi diversity mode, the SU-MIMO and MU-MIMO thresholds and criteria. Output TX i ic
•
CNR DLRS : Downlink reference signal C/N from cell TXi(ic) at pixel, subscriber, or mobile Mi.
•
CNR SS
TX ic i
: SS C/N from cell TXi(ic) at pixel, subscriber, or mobile Mi.
TX i ic
•
CNR PBCH : PBCH C/N from cell TXi(ic) at pixel, subscriber, or mobile Mi.
•
CNR PDCCH : PDCCH C/N from cell TXi(ic) at pixel, subscriber, or mobile Mi.
•
CNR PDSCH : PDSCH C/N from cell TXi(ic) at pixel, subscriber, or mobile Mi.
TX i ic TX i ic
6.4.4.5 C/(I+N) and Bearer Calculation (DL) The carrier signal to interference and noise ratio is calculated in three steps. First Atoll calculates the received signal level from the studied cell (as explained in "Signal Level Calculation (DL)" on page 501) at the pixel, subscriber, or mobile under study. Next, Atoll calculates the interference received at the same studied pixel, subscriber, or mobile from all the interfering cells (as explained in "Interference Calculation (DL)" on page 505). Interference from each cell is weighted according to the co- and adjacent channel overlap between the studied and the interfering cells, the traffic loads of the interfering cells, and the probability of collision in case ICIC is used by the cells. Finally, Atoll takes the ratio of the signal level and the sum of the total interference from other cells and the downlink noise (as calculated in "Noise Calculation (DL)" on page 505). The receiver terminal is always considered to be oriented towards its best server, except when the "Lock Status" is set to "Server+Orientation" for a subscriber in a subscriber list and its azimuth and tilt manually edited. In the case of NLOS between the receiver and the best server, Atoll does not try to find the direction of the strongest signal, the receiver is oriented towards the best server just as in the case of LOS. Input •
F : Subcarrier width (15 kHz).
•
W FB : Width of a frequency block (180 kHz).
•
N FB – SS PBCH : Number of frequency blocks that carry the SS and the PBCH (6).
•
N Slot SF : Number of slots per subframe (2).
•
D CP
•
N SD Slot : Number of symbol durations per slot (7 is D CP
•
N FB
TX i ic
: Cyclic prefix duration defined in TXi(ic) frame configuration or, otherwise, in the global network settings. TX i ic
TX i ic
TX i ic
is Normal, 6 if D CP
is Extended).
: Number of frequency blocks, defined in the frequency bands table, for the channel bandwidth used by the
cell TXi(ic). •
TX i ic
N SF – DL : Number of downlink subframes in the frame for the cell TXi(ic). It is equal to 10 for FDD frequency bands, and is determined from the cell’s TDD frame configuration for TDD frequency bands.
•
TX i ic
N TDD – SSF : Number of TDD special subframes (containing DwPTS, GP, and UpPTS) in the frame for the cell TXi(ic). It is equal to 0 for FDD frequency bands, and is determined from the cell’s TDD frame configuration for TDD frequency bands. TX i ic
TX i ic
N SF – DL and N TDD – SSF are determined as follows:
518
TX i ic
TX i ic
Configuration
N SF – DL
N TDD – SSF
FDD
10
0
DSUUU-DSUUU
2
2
DSUUD-DSUUD
4
2
DSUDD-DSUDD
6
2
DSUUU-DSUUD
3
2
DSUUU-DDDDD
6
1
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AT330_TRR_E1
•
TX ic i
TX ic i
Configuration
N SF – DL
N TDD – SSF
DSUUD-DDDDD
7
1
DSUDD-DDDDD
8
1
TX i ic
E DLRS : Received downlink reference signal energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Signal Level Calculation (DL)" on page 501. TX i ic
•
E SS
: Received SS energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Signal Level Calculation (DL)" on page 501.
•
E PBCH : Received PBCH energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as
TX i ic
calculated in "Signal Level Calculation (DL)" on page 501. •
TX i ic
E PDCCH : Received PDCCH energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Signal Level Calculation (DL)" on page 501.
•
TX i ic
E PDSCH : Received PDSCH energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Signal Level Calculation (DL)" on page 501.
•
TX ic i
N Sym – PDCCH : Number of PDCCH resource elements as calculated in "Downlink Transmission Power Calculation" on page 485.
•
TX ic i
N Sym – PDSCH : Number of PDSCH resource elements as calculated in "Downlink Transmission Power Calculation" on page 485. TX ic i
•
n Sym
: Downlink noise for one subcarrier for the cell TXi(ic) as calculated in "Noise Calculation (DL)" on page 505.
•
DLRS : Interfering energy per resource element (dBm/Sym) received over downlink reference signals from any cell
TX j jc
TXj(jc) at a pixel, subscriber, or mobile Mi covered by a cell TXi(ic) as calculated in "Interference Calculation (DL)" on page 505. •
TX j jc
SS PBCH : Interfering energy per resource element (dBm/Sym) received over the SS and the PBCH from any cell TXj(jc) at a pixel, subscriber, or mobile Mi covered by a cell TXi(ic) as calculated in "Interference Calculation (DL)" on page 505.
•
TX j jc
PDSCH : Interfering energy per resource element (dBm/Sym) received over the PDSCH from any cell TXj(jc) at a pixel, subscriber, or mobile Mi covered by a cell TXi(ic) as calculated in "Interference Calculation (DL)" on page 505.
•
TX j jc
PDCCH : Interfering energy per resource element (dBm/Sym) received over the PDCCH from any cell TXj(jc) at a pixel, subscriber, or mobile Mi covered by a cell TXi(ic) as calculated in "Interference Calculation (DL)" on page 505.
•
TX j jc
RSSI : Interfering energy per frequency block (dBm/RB) received over 1 frequency block during an OFDM symbol carrying reference signals from any cell TXj(jc) at a pixel, subscriber, or mobile Mi as calculated in "Interference Calculation (DL)" on page 505. Inter – Tech
•
NR DL
•
CNR DLRS : Downlink reference signal C/N from cell TXi(ic) at pixel, subscriber, or mobile Mi as calculated in "C/N
: Inter-technology downlink noise rise.
TX i ic
Calculation (DL)" on page 516. Mi
•
T SU – MIMO – DL : SU-MIMO threshold defined in the reception equipment used by Mi’s terminal.
•
T B : Bearer selection thresholds of the bearers defined in the reception equipment used by Mi’s terminal.
•
B DL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
Mi M
i
or mobile Mi. •
Mi
B DL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber, or mobile Mi.
•
TX ic i
N Ant – TX : Number of transmission (downlink) antenna ports defined for the cell TXi(ic).
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i
N Ant – RX : Number of reception (downlink) antenna ports defined for the terminal used by the pixel, subscriber, or mobile Mi.
•
Mobility M i : Mobility used for the calculations.
•
i BLER BDL : Downlink block error rate read from the graphs available in the reception equipment assigned to the
M
terminal used by the pixel, subscriber, or mobile Mi. Mi
•
G Div – PBCH : PBCH diversity gain defined in the reception equipment of the terminal used by the pixel, subscriber, or mobile Mi. Mi
G Div – PDCCH : PDCCH diversity gain defined in the reception equipment of the terminal used by the pixel, subscriber,
•
or mobile Mi. DL
G Div : Additional downlink diversity gain defined for the clutter class where the pixel, subscriber, or mobile Mi is
•
located. Inter – Tech
•
I DL
: Downlink inter-technology interference as calculated in "Interference Calculation (DL)" on page 505.
Calculations The downlink reference signal C/(I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX jc
TX i ic
CINR DLRS
TX ic
i j n Sym DLRS - --------------------------------------- TX i ic 10 10 + I Inter – Tech + 10 10 + NR Inter – Tech = E DLRS – 10 Log DL DL All TXj jc
The SS C/(I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX jc
TX ic i CINR SS
=
TX ic i E SS
TX ic
i j n Sym SS PBCH- --------------------------------------------- Inter – Tech Inter – Tech 10 10 + NR 10 +I – 10 Log + 10 DL DL All TXj jc
The PBCH C/(I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX jc
TX i ic
CINR PBCH
TX ic
i j n Sym SS PBCH --------------------------------------------- TX i ic 10 10 + I Inter – Tech + 10 10 + NR Inter – Tech = E PBCH – 10 Log DL DL All TXj jc
The PDCCH C/(I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX jc
TX i ic
CINR PDCCH
TX ic
i j n PDCCH Sym ------------------- --------------------- TX i ic Inter – Tech Inter – Tech 10 10 10 +I +10 + NR DL = E PDCCH – 10 Log DL All TXj jc
The PDSCH C/(I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX jc
TX i ic
CINR PDSCH
TX ic
i j n PDSCH Sym ------------------- --------------------- TX i ic Inter – Tech Inter – Tech 10 10 10 +I + NR +10 = E PDSCH – 10 Log DL DL All TXj jc
The downlink reference signal received quality (RSRQ) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: RSRQ
520
TX i ic
TX i ic
= 10 Log N FB
TX ic
+ E i – RSSI DLRS
TX i ic
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1 TX ic i
Where E DLRS
is the cell’s RSRP and RSSI
TX ic i
is the received signal strength indicator, i.e., the received signals from the
server (TXi(ic)), and all the interfering cells (TXj(jc)), calculated as follows: For cells using more than 1 antenna port, the encircled 10 in the formulas below is replaced with 8.
TX jc
RSSI
TX ic i
TX ic
i j n Sym RSSI - TX ic --------------------------------------TX ic 10 10 i Inter – Tech Inter – Tech i = 10 Log RSSI + 10 + + 10 12 + NR DL + 10 Log N FB I DL All TX j jc
The downlink reference signal total noise (I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX jc
TX i ic
I + N DLRS
TX ic
i j n Sym DLRS --------------------------------------- TX ic Inter – Tech 10 10 + NR Inter – Tech + 10 Log 2 N i 10 +I = 10 Log + 10 DL FB DL All TXj jc
The SS and PBCH total noise (I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX jc
TX i ic
I + N SS PBCH
TX ic
i j n Sym SS PBCH --------------------------------------------- 10 10 + I Inter – Tech + 10 10 + NRInter – Tech + 10 Log N = 10 Log DL SCa – FB N FB – SS PBCH DL All TX j jc
The PDSCH and PDCCH total noise (I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: Method 1: Synchronised Transmission and Reception For details, see "Interference Calculation (DL)" on page 456.
TX i ic
I + N PDCCH
TX i ic
I + N PDSCH
TX jc
TX ic
TX jc
TX ic
i j n Sym TX i ic PDCCH ------------------- --------------------- N Sym – PDCCH Inter – Tech – Tech 10 10 - + NR Inter = 10 Log 10 +I + 10 + 10 Log ---------------------------------------------DL TX i ic TX i ic DL N SF – DL + N TDD – SSF All TXj jc
i j n TX ic PDSCH- Sym - i --------------------------------------N Sym – PDSCH 10 10 Inter – Tech – Tech - + NR Inter = 10 Log 10 + I DL + 10 + 10 Log ---------------------------------------------DL TX ic TXi ic i N SF – DL + N TDD – SSF All TXj jc
Method 2: Non-synchronised Transmission and Reception For details, see "Interference Calculation (DL)" on page 456. TX jc
TX i ic
I + N PDCCH
TX jc
TX i ic
I + N PDSCH
TX ic
i j n Sym TX ic PDCCH i N TXi ic ---------------------------------------- – Inter – Tech 10 10 Sym – PDSCH + N Sym – PDCCH - + NR Inter = 10 Log 10 + I DL + 10 + 10 Log ------------------------------------------------------------------DL TX ic i N SD Slot N Slot SF N SF – DL All TXj jc TX ic
i j n Sym TX i ic PDSCH- N TXi ic ---------------------------------------- – Inter – Tech 10 10 Sym – PDSCH + N Sym – PDCCH -------------------------------------------------------------------- + NR Inter = 10 Log + 10 DL TX i ic 10 + I DL + 10 Log All TXj jc N SD Slot N Slot SF N SF – DL
With N SCa – FB calculated as follows: W FB N SCa – FB = --------F Bearer Determination:
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The bearers available for selection in the pixel, subscriber, or mobile Mi’s reception equipment are the ones: •
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
•
Whose selection thresholds are less than the PDSCH C/(I+N) at Mi: T B CINR PDSCH
Mi
TX i ic
If the cell supports MIMO, and according to the Mi diversity mode depending on the SU-MIMO and MU-MIMO Mi
thresholds and criteria, transmit diversity, SU-MIMO diversity, or MU-MIMO diversity gain, G Div – DL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the TX i ic
Mi
reception equipment assigned to the pixel, subscriber, or mobile Mi for N Ant – TX , N Ant – RX , Mobility M i , M
i BLER B DL . DL
The additional downlink diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the reception equipment for which the following is true: M
M
i
i
TX ic i
DL
T B – G Div – DL – G Div CINR PDSCH The bearer selected for data transfer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic). •
Bearer Index From among the bearers available for selection, the selected bearer is the one with the highest index.
•
Peak RLC Throughput From among the bearers available for selection, the selected bearer is the one with the highest downlink peak RLC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation" on page 547.
•
Effective RLC Throughput From among the bearers available for selection, the selected bearer is the one with the highest downlink effective RLC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation" on page 547.
MIMO Diversity Gain: With MIMO, the PBCH and PDCCH C/(I+N) become: TX i ic
TX i ic
Mi
TX i ic
TX i ic
Mi
DL
CINR PBCH = CINR PBCH + G Div – PBCH + G Div DL
CINR PDCCH = CINR PDCCH + G Div – PDCCH + G Div The PBCH and PDCCH diversity gains are applied to the C/(I+N) when the cell and the terminal both support any form of MIMO in downlink. The additional downlink diversity gain defined per clutter is also applied. Once the bearer is known, the PDSCH C/(I+N) calculated above becomes: TX i ic
TX i ic
Mi
DL
CINR PDSCH = CINR PDSCH + G Div – DL + G Div Mi
Where G Div – DL is the transmit diversity, SU-MIMO diversity, or MU-MIMO diversity gain applied if the cell supports MIMO and depending on the Mi diversity mode, the SU-MIMO and MU-MIMO thresholds and criteria. Output
522
TX i ic
•
CINR DLRS : Downlink reference signal C/(I+N) from cell TXi(ic) at pixel, subscriber, or mobile Mi.
•
CINR SS
: SS C/(I+N) from cell TXi(ic) at pixel, subscriber, or mobile Mi.
•
TX ic i CINR PBCH
: PBCH C/(I+N) from cell TXi(ic) at pixel, subscriber, or mobile Mi.
TX i ic
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1 TX ic i
•
CINR PDCCH : PDCCH C/(I+N) from cell TXi(ic) at pixel, subscriber, or mobile Mi.
•
CINR PDSCH : PDSCH C/(I+N) from cell TXi(ic) at pixel, subscriber, or mobile Mi.
•
RSRQ
TX ic i
TX ic i
: Downlink reference signal received quality from cell TXi(ic) at pixel, subscriber, or mobile Mi.
TX i ic
•
RSSI : Received signal strength indicator, i.e., the received signals from the server (TXi(ic)), and all the interfering cells (TXj(jc)), at pixel, subscriber, or mobile Mi.
•
I + N DLRS : Downlink reference signals total noise from the interfering cells TXj(jc) at the pixel, subscriber, or mobile
TX ic i
Mi covered by a cell TXi(ic). •
TX i ic
I + N SS PBCH : SS and PBCH total noise from the interfering cells TXj(jc) at the pixel, subscriber, or mobile Mi covered by a cell TXi(ic).
•
TX i ic
I + N PDCCH : PDCCH total noise from the interfering cells TXj(jc) at the pixel, subscriber, or mobile Mi covered by a cell TXi(ic).
•
TX i ic
I + N PDSCH : PDSCH total noise from the interfering cells TXj(jc) at the pixel, subscriber, or mobile Mi covered by a cell TXi(ic).
•
Mi
B DL : Bearer assigned to the pixel, subscriber, or mobile Mi in the downlink.
6.4.4.6 Signal Level Calculation (UL) Input TX i ic
•
CINR PUSCH – Max : Maximum PUSCH C/(I+N) defined for the cell TXi(ic).
•
NR UL
TX ic i
: Uplink noise rise of the cell TXi(ic). This value can be user-defined or calculated as explained in "Interference
Calculation (UL)" on page 525. TX ic i
•
NR UL – ICIC : ICIC uplink noise rise of the cell TXi(ic). This value can be user-defined or calculated as explained in "Interference Calculation (UL)" on page 525.
•
n PUSCH PUCCH : Uplink noise for the PUSCH and the PUCCH for the cell TXi(ic).
•
N FB
TX i ic
TX i ic
: Number of frequency blocks, defined in the frequency bands table, for the channel bandwidth used by the
cell TXi(ic). TX ic i
•
FPC
•
P Max : Maximum transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
P Eff : Effective transmission power of the terminal used by the pixel, subscriber, or mobile Mi after power control
: Fractional uplink power control factor defined for the cell TXi(ic).
Mi Mi
adjustment as calculated in "C/(I+N) and Bearer Calculation (UL)" on page 532. TX i
•
G Ant : Transmitter antenna gain for the antenna used by the transmitter TXi.
•
L
•
L Path : Path loss ( L Path = L Model + L Ant ).
•
L Total : Total loss calculated as explained in "Signal Level Calculation (DL)" on page 501.
•
L Model : Loss on the transmitter-receiver path (path loss) calculated using a propagation model.
•
L Ant : Antenna attenuation (from antenna patterns) calculated for the antenna used by the transmitter TXi.
•
M Shadowing – Model : Shadowing margin based on the model standard deviation.
TX i
: Total transmitter losses for the transmitter TXi ( L
TX i
= L Total – UL ).
TX i
TX
i
In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. •
L Indoor : Indoor losses taken into account when the option "Indoor coverage" is selected.
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L
M
i
M
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: Receiver terminal losses for the pixel, subscriber, or mobile Mi. i
•
G
•
L Ant : Receiver terminal’s antenna attenuation calculated for the pixel, subscriber, or mobile Mi.
M
: Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi.
i
Mi
For calculating the useful signal level from the best serving cell, L Ant is determined in the direction (H,V) = (0,0) from Mi
the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, L Ant is determined in the direction of the interfering cell from the antenna patterns of the antenna used by Mi, while the antenna is pointed towards Mi’s best serving cell. Mi
•
L Body : Body loss defined for the service used by the pixel, subscriber, or mobile Mi.
•
D CP
TX i ic
: Cyclic prefix duration defined in TXi(ic) frame configuration or, otherwise, in the global network settings.
Calculations Atoll first calculates the allowed maximum transmission power for the terminal used by the pixel, subscriber, or mobile Mi. This power is calculated by performing fractional power control. Fractional Power Control: Fractional power control imposes a limitation on the maximum transmission power of the terminal. A nominal PUSCH power is indicated by the cell to all the pixels, subscribers, or mobiles. This nominal PUSCH power is calculated as follows: TX i ic
TX i ic
TX i ic
TX ic
TX ic
TX ic
P O_PUSCH = CINR PUSCH – Max + NRUL
TX ic
TX ic
i i + n PUSCH PUCCH – 10 Log N FB TX ic
for cell centre.
TX ic
i i i i i P O_PUSCH = CINR PUSCH – Max + NRUL – ICIC + n PUSCH PUCCH – 10 Log NFB TX i ic
for cell-edge.
TX i ic
Where n PUSCH PUCCH – 10 Log N FB
corresponds to the uplink noise over 1 frequency block.
Next, the maximum allowed transmission power for the terminal used by the pixel, subscriber, or mobile Mi is calculated as follows: Mi TX i ic TX i ic TX i ic Mi P Allowed = Min P Max 10 Log NFB + P O_PUSCH + FPC L Total
Once the maximum allowed power has been calculated, it is used as an upper limit for transmission power in all the remaining calculations. The received PUSCH and PUCCH signal level (dBm) from a pixel, subscriber, or mobile Mi at its serving cell TXi(ic) is calculated as follows: Mi
Mi
TX i
C PUSCH PUCCH = EIRP PUSCH PUCCH – L Path – M Shadowing – Model – L Indoor + G Ant – L
TX i
Mi
Mi
– L Ant – L Body + f CP
Where EIRP is the effective isotropic radiated power of the terminal calculated as follows: Mi
EIRP PUSCH PUCCH = P With P
Mi
Mi
Mi
+G
Mi
–L
Mi
= P Allowed without power control adjustment at the start of the calculations, and is P
Mi
Mi
= P Eff after power control
adjustment. f CP is the cyclic prefix factor, i.e., the ratio of the useful symbol energy to the total symbol energy. The total symbol duration of a modulation symbol comprises the useful symbol duration, carrying the actual data bits, and a cyclic prefix, added to the useful data bits as padding against multi-path to avoid inter-symbol interference. Hence, the total energy within a modulation symbol belongs in part to the useful data bits and in part to the cyclic prefix. Once a modulation
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symbol is received, only the energy of the useful data bits can be used for extracting the data. The energy belonging to the cyclic prefix is lost once it has served its purpose of combatting inter-symbol interference. Therefore, f CP implies that the energy belonging to the cyclic prefix is excluded from the useful signal level.
f CP
TX ic 10 Log 7 7.5 If D CPi = Normal TX i ic = = Extended 10 Log 6 7.5 If D CP is an interferer 0 If M i
The cyclic prefix energy and the useful data bits energy are both taken into account when calculating interfering signal levels. Output Mi
•
C PUSCH PUCCH : Received PUSCH and PUCCH signal level from the pixel, subscriber, or mobile Mi at a cell TXi(ic).
•
P Allowed : Maximum allowed transmission power for the terminal used by the pixel, subscriber, or mobile Mi.
Mi
6.4.4.7 Noise Calculation (UL) For determining the C/N and C/(I+N), Atoll calculates the uplink noise over the channel bandwidth used by the cell. The used bandwidth depends on the number of used subcarriers. The uplink noise comprises thermal noise and the noise figure of the equipment. The thermal noise density depends on the temperature, i.e., it remains constant for a given temperature. However, the value of the thermal noise varies with the used bandwidth. Input • • •
K: Boltzmann’s constant. T: Temperature in Kelvin. W FB : Width of a frequency block in the frequency domain (180 kHz).
•
N FB
TX i ic
: Number of frequency blocks, defined in the frequency bands table, for the channel bandwidth used by the
cell TXi(ic). •
nf
TX i ic
: Noise figure of the cell TXi(ic).
Calculations The power spectral density of thermal noise is calculated as follows: n 0 = 10 Log K T 1000 = – 174 dBm/Hz The thermal noise for the PUSCH and the PUCCH is calculated as: TX i ic
TX i ic
n 0 – PUSCH PUCCH = n 0 + 10 Log N FB
W FB 1000
The uplink noise is the sum of the thermal noise and the noise figure of the cell TXi(ic). TX i ic
TX i ic
n PUSCH PUCCH = n 0 – PUSCH PUCCH + nf
TX i ic
Output •
TX i ic
n PUSCH PUCCH : Uplink noise for the PUSCH and the PUCCH for the cell TXi(ic).
6.4.4.8 Interference Calculation (UL) The PUSCH and PUCCH interference is only calculated during Monte Carlo simulations. In coverage predictions, the uplink noise rise values already available in simulation results or in the Cells table are used. The interference received by a cell TXi(ic) from an interfering mobile covered by a cell TXj(jc) can be defined as the PUSCH and PUCCH signal level received from the interfering mobile Mj depending on the overlap that exists between the channels used by the cells TXi(ic) and TXj(jc) and on the traffic load of the interfering mobile Mj.
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The calculation of uplink interference can be divided into two parts: • •
6.4.4.8.1
Calculation of the uplink interference from each individual interfering mobile as explained in "Interfering Signal Level Calculation (UL)" on page 526. Calculation of the uplink noise rise which represents the total uplink interference from all interfering mobiles as explained in "Noise Rise Calculation (UL)" on page 528.
Interfering Signal Level Calculation (UL) Input TX ic i
N FB
•
TX jc j
and N FB
: Total number of frequency blocks defined in the frequency bands table for the channel
bandwidth used by the cell. TX i ic
TX j jc
N FB – CE0 and N FB – CE0 : Number of cell-edge frequency blocks defined in the frame configurations table for the
•
channel bandwidth used by the cell and PSS ID 0. TX i ic
TX j jc
N FB – CE1 and N FB – CE1 : Number of cell-edge frequency blocks defined in the frame configurations table for the
•
channel bandwidth used by the cell and PSS ID 1. TX i ic
TX j jc
N FB – CE2 and N FB – CE2 : Number of cell-edge frequency blocks defined in the frame configurations table for the
•
channel bandwidth used by the cell and PSS ID 2. Mj
C PUSCH PUCCH : PUSCH and PUCCH signal level received at a cell TXi(ic) from an interfering mobile Mj covered by a cell
•
TXj(jc) as calculated in "Signal Level Calculation (UL)" on page 523. •
M Shadowing – Model : Shadowing margin based on the model standard deviation.
•
M Shadowing – C I : Shadowing margin based on the C/I standard deviation. In Monte Carlo simulations, interfering signal levels already include M Shadowing – Model , as explained in "Signal Level Calculation (UL)" on page 523. In coverage predictions, the ratio M Shadowing – Model – M Shadowing – C I is applied to the interfering signals (for more information, see "Shadow Fading Model" on page 90). As the interfering signal levels already include M Shadowing – Model , M Shadowing – C I is added to the received interfering signal levels in order to achieve the ratio M Shadowing – Model – M Shadowing – C I : M
M
j
j
C PUSCH PUCCH = C PUSCH PUCCH + M Shadowing – C I In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. TX i ic – TX j jc
•
rO
: Total channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 493.
•
TL UL : Uplink traffic load of the interfering mobile Mj.
Mj
Traffic loads are calculated during Monte Carlo simulations as explained in "Scheduling and Radio Resource Allocation" on page 552. Calculations The uplink interference received at a cell TXi(ic) from an interfering mobile Mj covered by a cell TXj(jc) is calculated as follows: Mj
TX i ic – TX j jc
Mj
I PUSCH PUCCH = C PUSCH PUCCH + f O Mj
Mj
TX i ic – TX j jc
+ f TL – UL + f ICIC – UL
TX i ic – TX j jc
+ f ABS – UL
Where f TL – UL is an interference reduction factor due to the uplink traffic load of the interfering mobile Mj, calculated as follows: M
M
j j f TL – UL = 10 Log TL UL
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TX ic – TX jc i j
Calculations for the interference reduction factors due to channel overlapping ( f O TX ic – TX jc i j
fractional frequency reuse ( f ICIC – UL
) and static uplink ICIC using
) are explained below:
Interference reduction due to the co- and adjacent channel overlap between the studied and the interfering cells: Interference reduction due to the co- and adjacent channel overlap between the cells TXi(ic) and TXj(jc) is calculated as follows: TX i ic – TX j jc
fO
TX i ic – TX j jc
= 10 Log r O
Interference reduction due to static uplink ICIC using fractional frequency reuse: If the cell supports static ICIC in uplink, it means that a part of the LTE frame may use a fraction of the channel bandwidth. The interference reduction factor due to static uplink ICIC using fractional frequency reuse is calculated as follows: TX i ic – TX j jc
f ICIC – UL
TX i ic – TX j jc
= 10 Log p Collision
TX i ic – TX j jc
Where p Collision
is the collision probability between the subcarriers used by the interfered and interfering cells.
It is determined during Monte Carlo simulations as follows: TX i ic – TX j jc
Cell centre: p Collision
TX i ic – TX j jc
Cell-edge: p Collision
Common
Where, N FB – CC
Common
N FB – CC = -------------------TX i ic N FB – CC Common
N FB – CE = -------------------TX ic i N FB – CE Common
is the number of common frequency blocks in TXi(ic) and TXj(jc) in cell centre, N FB – CE TX i ic
is the
TX i ic
number of common frequency blocks in TXi(ic) and TXj(jc) on cell-edge, N FB – CC and N FB – CE are respectively the numbers of frequency blocks in cell centre and cell-edge of TXi(ic). Number of frequency blocks in
ICIC mode
Cell centre
Cell edge
TX i ic
No FFR
N FB
Time-switched FFR
N FB
TX i ic
N FB
TX i ic
TX i ic
N FB – CEx
TX i ic
Hard FFR
TX i ic
N FB – CEx TX ic i
Soft FFR
N FB
Partial soft FFR
TX ic i
TX i ic
N FB
N FB – CEx
TX ic i
TX ic i
– N FB – CEx
TX ic
TX ic
N FB – CEx TX ic
i i i – N FB – CE0 + N FB – CE1 + N FB – CE2
TX ic i
TX ic i
TX i ic
N FB – CEx
TX ic i
Where N FB – CEx can be N FB – CE0 , N FB – CE1 , or N FB – CE2 depending on the PSS ID of TXi(ic). Whether a pixel, subscriber, or mobile is located in the cell-edge is determined as explained in "Best Server Determination" on page 535. Interference reduction due to subframe collision probabilities: TX i ic – TX j jc
The interference reduction factor due to uplink subframe collision probabilities f ABS – UL
is calculated as
explained in "Subframe Pattern Collision Calculation" on page 497. In Monte Carlo simulations, Atoll calculates two separate noise rise values; for the mobiles located in the cell-edge of the interfered cell Atoll calculates the ICIC UL Noise Rise, and for the mobiles located in the cell centre of the interfered cell Atoll calculates the UL Noise Rise.
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In coverage predictions, point analysis, and calculations on subscriber lists, according to the zone, cell centre or cell-edge, where the pixel, receiver, or subscriber is located, Atoll uses either the ICIC UL Noise Rise or the UL Noise Rise to calculate the PUSCH and PUCCH C/(I+N). For more information on the calculation of the uplink noise rise, see "Noise Rise Calculation (UL)" on page 528. Output Mj
I PUSCH PUCCH : PUSCH and PUCCH interference signal level received at a cell TXi(ic) from an interfering mobile Mj
•
covered by a cell TXj(jc).
6.4.4.8.2
Noise Rise Calculation (UL) The uplink noise rise is defined as the ratio of the total uplink interference received by any cell TXi(ic) from all interfering mobiles Mj present in the coverage areas of all other cells TXj(jc) to the uplink noise of the cell TXi(ic). In other words, it is the ratio (I+N)/N. Input Mj
I PUSCH PUCCH : PUSCH and PUCCH interference signal levels received at a cell TXi(ic) from interfering mobiles Mj
•
covered by other cells TXj(jc) as calculated in "Interfering Signal Level Calculation (UL)" on page 526. TX i ic
n PUSCH PUCCH : Uplink noise for the PUSCH and the PUCCH for the cell TXi(ic) as calculated in "Noise Calculation (UL)"
•
on page 525. Inter – Tech
•
NRUL
: Inter-technology uplink noise rise.
Calculations For any mobile Mi in the cell centre of the interfered cell TXi(ic), Atoll calculates the UL Noise Rise as follows: M
TX i ic
NR UL
j TX ic I PUSCH PUCCH i non-ICIC M i n PUSCH PUCCH - ------------------------------------------- TX ic ----------------------------------------------------------------------------10 10 + NR Inter – Tech – n i = 10 Log 10 + 10 UL PUSCH PUCCH All M j All TXj jc
For any pixel, subscriber, or mobile Mi in the cell centre of the interfered cell TXi(ic), Atoll calculates the PUSCH and PUCCH total noise (I+N) as follows: TX i ic
TX i ic
I + N PUSCH PUCCH = NR UL
TX i ic
+ n PUSCH PUCCH
For any mobile Mi in the cell-edge of the interfered cell TXi(ic), Atoll calculates the ICIC UL Noise Rise as follows: M
TX i ic
NR UL – ICIC
j TX i ic IPUSCH PUCCH ICIC M i n PUSCH PUCCH - ------------------------------------------- TX ic -----------------------------------------------------------------10 10 + NR Inter – Tech – n i = 10 Log 10 + 10 UL PUSCH PUCCH All Mj All TXj jc
For any pixel, subscriber, or mobile Mi in cell-edge of the interfered cell TXi(ic), Atoll calculates the PUSCH and PUCCH total noise (I+N) as follows: TX ic i
TX ic i
TX ic i
I + N PUSCH PUCCH = NR UL – ICIC + n PUSCH PUCCH Output •
528
TX i ic
NRUL
: Uplink noise rise for the cell TXi(ic).
TX i ic
•
NRUL – ICIC : ICIC uplink noise rise for the cell TXi(ic).
•
I + N PUSCH PUCCH : PUSCH and PUCCH total noise for a cell TXi(ic) calculated for any pixel, subscriber, or mobile Mi.
TX i ic
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6.4.4.9 C/N Calculation (UL) Input •
M
i
C PUSCH PUCCH : Received PUSCH and PUCCH signal level from the pixel, subscriber, or mobile Mi at its serving cell TXi(ic) as calculated in "Signal Level Calculation (UL)" on page 523. TX i ic
•
n PUSCH PUCCH : PUSCH and PUCCH noise for the cell TXi(ic) as calculated in "Noise Calculation (UL)" on page 525.
•
T SU – MIMO – UL : SU-MIMO threshold defined in the reception equipment of the cell TXi(ic).
•
N FB
TX i ic
TX ic i
: Total number of frequency blocks defined in the frequency bands table for the channel bandwidth used by
the cell TXi(ic). •
TX i ic
N FB – CE0 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 0.
•
TX ic i
N FB – CE1 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 1.
•
TX i ic
N FB – CE2 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 2. TX i ic
•
T B – Lowest : Bearer selection threshold of the lowest bearer in the reception equipment assigned to the cell TXi(ic).
•
P Allowed : Maximum allowed transmission power of the terminal used by the pixel, subscriber, or mobile Mi as
Mi
calculated in "Signal Level Calculation (UL)" on page 523. Mi
•
P Min : Minimum transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
M PC : Power control adjustment margin defined in the global network settings.
•
T B : Bearer selection thresholds of the bearers defined in the reception equipment used bythe cell TXi(ic).
•
B UL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
Mi
Mi
or mobile Mi. •
Mi
B UL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber, or mobile Mi.
•
M
i
N Ant – TX : Number of transmission (uplink) antenna ports defined for the terminal used by the pixel, subscriber, or mobile Mi. TX i ic
•
N Ant – RX : Number of reception (uplink) antenna ports defined for the cell TXi(ic).
•
Mobility M i : Mobility used for the calculations.
•
M
i BLER B UL : Uplink block error rate read from the graphs available in the reception equipment assigned to the cell TXi(ic).
Calculations The PUSCH and PUCCH C/N from a pixel, subscriber, or mobile Mi at its serving cell TXi(ic) is calculated as follows: Mi
Mi
TX i ic
CNR PUSCH PUCCH = C PUSCH PUCCH – n PUSCH PUCCH Bearer Determination: The bearers available for selection in the cell TXi(ic)’s reception equipment are the ones: •
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
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i
M
i
Whose selection thresholds are less than the PUSCH and PUCCH C/N at Mi: T B CNR PUSCH PUCCH If the cell supports MIMO, and according to the Mi diversity mode depending on the SU-MIMO and MU-MIMO TX ic i
thresholds and criteria, receive diversity, SU-MIMO diversity, or MU-MIMO diversity gain, G Div – UL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the M
TX ic
M
i i i reception equipment assigned to the cell TXi(ic) for N Ant – TX , N Ant – RX , Mobility M i , BLER B UL . UL
The additional uplink diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the reception equipment for which the following is true: Mi
TX i ic
Mi
UL
T B – G Div – UL – G Div CNR PUSCH PUCCH The bearer selected for data transfer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic). •
Bearer Index From among the bearers available for selection, the selected bearer is the one with the highest index.
•
Peak RLC Throughput From among the bearers available for selection, the selected bearer is the one with the highest uplink peak RLC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation" on page 547.
•
Effective RLC Throughput From among the bearers available for selection, the selected bearer is the one with the highest uplink effective RLC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation" on page 547.
MIMO Diversity Gain: Once the bearer is known, the PUSCH and PUCCH C/N calculated above become: Mi
TX i ic
Mi
UL
CNR PUSCH PUCCH = CNR PUSCH PUCCH + G Div – UL + G Div TX i ic
Where G Div – UL is the receive diversity, SU-MIMO diversity, or MU-MIMO diversity gain applied if the cell supports MIMO and depending on the Mi diversity mode, the SU-MIMO and MU-MIMO threshold and criteria. Uplink Bandwidth Allocation (No. of Used Frequency Blocks): The uplink bandwidth allocation depends on the target defined for the scheduler used by the cell TXi(ic). The PUSCH and PUCCH C/N calculated above is given for the total number of frequency blocks associated with the channel TX i ic
bandwidth of the cell, i.e., N FB
. Bandwidth allocation is performed for all the pixels, subscribers, or mobiles in the
uplink, and may reduce the number of used frequency blocks in order to satisfy the selected target. •
Full Bandwidth Full channel width is used by each mobile in the uplink. As there is no reduction in the bandwidth used for transmission, there is no gain in the PUSCH and PUCCH C/N.
•
Maintain Connection The bandwidth used for transmission by a mobile is reduced only if the PUSCH and PUCCH C/N is not enough to even access the lowest bearer. For example, as a mobile moves from good to bad radio conditions, the number of frequency blocks used by it for transmission in uplink are reduced one by one in order to improve the PUSCH and PUCCH C/N. The calculation of the gain introduced by the bandwidth reduction is explained below.
•
Best Bearer The bandwidth used for transmission by a mobile is reduced in order to improve the PUSCH and PUCCH C/N enough to access the best bearer. For example, if using 5 frequency blocks, a mobile is able to access the best bearer, and using 6 it would only get access to the second best, it will be assigned 5 frequency blocks as the used uplink bandwidth. Although using 4 frequency blocks, its PUSCH and PUCCH C/N will be better than when using 5, the uplink bandwidth is not reduced to 4 because it does not provide any gain in terms of the bearer, i.e., the mobile already has the best bearer using 5 frequency blocks. The calculation of the gain introduced by the bandwidth reduction is explained below.
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The definition of the best bearer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic), i.e., bearer with the highest index, with the highest peak RLC throughput, or with the highest effective RLC throughput. The uplink bandwidth allocation may result in the use of a number of frequency blocks which is less than the number of frequency blocks associated with the channel bandwidth of the cell. The gain related to this bandwidth reduction is applied to the PUSCH and PUCCH C/N: Mi
CNR PUSCH PUCCH Final
N TX i ic FB - = CNR PUSCH PUCCH + 10 Log ---------------- Mi All FB N FB – UL Mi
TX i ic
Mi
Min
Where N FB – UL Service N FB – UL N FB – CC for any pixel, subscriber, or mobile Mi in the cell centre of the interfered TX i ic
Mi
Min
cell TXi(ic), and N FB – UL Service N FB – UL N FB – CE for any pixel, subscriber, or mobile Mi in the cell-edge of the interfered cell TXi(ic). Number of frequency blocks in
ICIC mode
Cell centre
Cell edge
TX ic i N FB
No FFR
TX ic i
N FB
TX i ic
Time-switched FFR
TX i ic
N FB
N FB – CEx
TX i ic
Hard FFR
TX i ic
N FB – CEx TX i ic
Soft FFR
N FB TX i ic
Partial soft FFR
N FB
TX i ic
N FB – CEx
TX i ic
TX i ic
– N FB – CEx
TX ic
N FB – CEx
TX ic
TX ic
TX i ic
i i i – N FB – CE0 + N FB – CE1 + N FB – CE2
TX i ic
TX i ic
N FB – CEx
TX i ic
Where N FB – CEx can be N FB – CE0 , N FB – CE1 , or N FB – CE2 depending on the PSS ID of TXi(ic). Uplink Power Control Adjustment: Once the bandwidth allocation is performed, Atoll continues to work with the C/N given by the bandwidth allocation, Mi
Mi
i.e., CNR PUSCH PUCCH = CNR PUSCH PUCCH . Final
The pixel, subscriber, or mobile Mi reduces its transmission power so that the PUSCH and PUCCH C/N from it at its cell is just enough to get the selected bearer. If with P
Mi
Mi
Mi
= P Allowed AND CNR PUSCH PUCCH T
TX i ic Mi
+ M PC , where T
B UL
TX i ic Mi B UL
is the bearer selection threshold, from
the reception equipment assigned to the cell TXi(ic), for the bearer selected for the pixel, subscriber, or mobile Mi. The transmission power of Mi is reduced to determine the effective transmission power from the pixel, subscriber, or mobile Mi as follows: Mi Mi Mi TXi ic Mi P Eff = Max P Allowed – CNR PUSCH PUCCH – T M + M PC P Min i B UL
Mi
Mi
CNR PUSCH PUCCH is calculated again using P Eff . Output •
Mi
CNR PUSCH PUCCH : PUSCH and PUCCH C/N from a pixel, subscriber, or mobile Mi at it serving cell TXi(ic).
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6.4.4.10 C/(I+N) and Bearer Calculation (UL) The carrier signal to interference and noise ratio is calculated in three steps. First, Atoll calculates the received signal level from each pixel, subscriber, or mobile at its serving cell using the effective power of the terminal used by the pixel, subscriber, or mobile as explained in "Signal Level Calculation (UL)" on page 523. Next, Atoll calculates the uplink carrier to noise ratio as explained in "C/N Calculation (UL)" on page 529. Finally, determines the uplink C/(I+N) by dividing the previously calculated uplink C/N by the uplink noise rise value of the cell as calculated in "Noise Rise Calculation (UL)" on page 528. The uplink noise rise can be set by the user manually for each cell or calculated using Monte Carlo simulations. The receiver terminal is always considered to be oriented towards its best server, except when the "Lock Status" is set to "Server+Orientation" for a subscriber in a subscriber list and its azimuth and tilt manually edited. In the case of NLOS between the receiver and the best server, Atoll does not try to find the direction of the strongest signal, the receiver is oriented towards the best server just as in the case of LOS. Input •
Mi
CNR PUSCH PUCCH : PUSCH and PUCCH C/N from a pixel, subscriber, or mobile Mi at it serving cell TXi(ic) as calculated in "C/N Calculation (UL)" on page 529.
•
TX i ic
NRUL
: Uplink noise rise for the cell TXi(ic) as calculated in "Noise Rise Calculation (UL)" on page 528.
TX i ic
•
NRUL – ICIC : ICIC uplink noise rise for the cell TXi(ic) as calculated in "Noise Rise Calculation (UL)" on page 528.
•
T SU – MIMO – UL : SU-MIMO threshold defined in the reception equipment of the cell TXi(c).
•
N FB
TX i ic
TX i ic
: Total number of frequency blocks defined in the frequency bands table for the channel bandwidth used by
the cell TXi(ic). •
TX i ic
N FB – CE0 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 0.
•
TX ic i
N FB – CE1 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 1.
•
TX i ic
N FB – CE2 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 2. TX i ic
•
T B – Lowest : Bearer selection threshold of the lowest bearer in the reception equipment assigned to the cell TXi(ic).
•
P Allowed : Maximum allowed transmission power of the terminal used by the pixel, subscriber, or mobile Mi as
Mi
calculated in "Signal Level Calculation (UL)" on page 523. Mi
•
P Min : Minimum transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
M PC : Power control adjustment margin defined in the global network settings.
•
T B : Bearer selection thresholds of the bearers defined in the reception equipment used bythe cell TXi(ic).
•
B UL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
Mi
Mi
or mobile Mi. •
Mi
B UL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber, or mobile Mi.
•
Mi
N Ant – TX : Number of transmission (uplink) antenna ports defined for the terminal used by the pixel, subscriber, or mobile Mi. N Ant – RX : Number of reception (uplink) antenna ports defined for the cell TXi(ic).
•
Mobility M i : Mobility used for the calculations.
•
532
TX i ic
•
M
i BLER BUL : Uplink block error rate read from the graphs available in the reception equipment assigned to the cell TXi(ic).
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Calculations For any pixel, subscriber, or mobile Mi in the cell centre of the interfered cell TXi(ic), Atoll calculates the PUSCH and PUCCH C/ (I+N) as follows: M
M
i
TX ic i
i
CINR PUSCH PUCCH = CNR PUSCH PUCCH – NR UL
For any pixel, subscriber, or mobile Mi in the cell-edge of the interfered cell TXi(ic), Atoll calculates the PUSCH and PUCCH C/ (I+N) as follows: Mi
TX i ic
Mi
CINR PUSCH PUCCH = CNR PUSCH PUCCH – NR UL – ICIC Bearer Determination: The bearers available for selection in the cell TXi(ic)’s reception equipment are the ones: •
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
•
Whose selection thresholds are less than the PUSCH and PUCCH C/(I+N) at Mi: T B CINR PUSCH PUCCH
Mi
Mi
If the cell supports MIMO, and according to the Mi diversity mode depending on the SU-MIMO and MU-MIMO TX i ic
thresholds and criteria, receive diversity, SU-MIMO diversity, or MU-MIMO diversity gain, G Div – UL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the M
TX ic
M
i i i reception equipment assigned to the cell TXi(ic) for N Ant – TX , N Ant – RX , Mobility M i , BLER BUL . UL
The additional uplink diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the reception equipment for which the following is true: M
i
TX ic i
M
UL
i
T B – G Div – UL – G Div CINR PUSCH PUCCH The bearer selected for data transfer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic). •
Bearer Index From among the bearers available for selection, the selected bearer is the one with the highest index.
•
Peak RLC Throughput From among the bearers available for selection, the selected bearer is the one with the highest uplink peak RLC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation" on page 547.
•
Effective RLC Throughput From among the bearers available for selection, the selected bearer is the one with the highest uplink effective RLC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation" on page 547.
MIMO Diversity Gain: Once the bearer is known, the PUSCH and PUCCH C/(I+N) calculated above become: Mi
Mi
TX i ic
UL
CINR PUSCH PUCCH = CINR PUSCH PUCCH + G Div – UL + G Div TX i ic
Where G Div – UL is the receive diversity, SU-MIMO diversity, or MU-MIMO diversity gain applied if the cell supports MIMO and depending on the Mi diversity mode, the SU-MIMO and MU-MIMO threshold and criteria. Uplink Bandwidth Allocation (No. of Used Frequency Blocks): The uplink bandwidth allocation depends on the target defined for the scheduler used by the cell TXi(ic). The PUSCH and PUCCH C/(I+N) calculated above is given for the total number of frequency blocks associated with the channel
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bandwidth of the cell, i.e., N FB
. Bandwidth allocation is performed for all the pixels, subscribers, or mobiles in the
uplink, and may reduce the number of used frequency blocks in order to satisfy the selected target. •
Full Bandwidth Full channel width is used by each mobile in the uplink. As there is no reduction in the bandwidth used for transmission, there is no gain in the PUSCH and PUCCH C/(I+N).
•
Maintain Connection The bandwidth used for transmission by a mobile is reduced only if the PUSCH and PUCCH C/(I+N) is not enough to even access the lowest bearer. For example, as a mobile moves from good to bad radio conditions, the number of frequency blocks used by it for transmission in uplink are reduced one by one in order to improve the PUSCH and PUCCH C/(I+N). The calculation of the gain introduced by the bandwidth reduction is explained below.
•
Best Bearer The bandwidth used for transmission by a mobile is reduced in order to improve the PUSCH and PUCCH C/(I+N) enough to access the best bearer. For example, if using 5 frequency blocks, a mobile is able to access the best bearer, and using 6 it would only get access to the second best, it will be assigned 5 frequency blocks as the used uplink bandwidth. Although using 4 frequency blocks, its PUSCH and PUCCH C/(I+N) will be better than when using 5, the uplink bandwidth is not reduced to 4 because it does not provide any gain in terms of the bearer, i.e., the mobile already has the best bearer using 5 frequency blocks. The calculation of the gain introduced by the bandwidth reduction is explained below. The definition of the best bearer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic), i.e., bearer with the highest index, with the highest peak RLC throughput, or with the highest effective RLC throughput.
The uplink bandwidth allocation may result in the use of a number of frequency blocks which is less than the number of frequency blocks associated with the channel bandwidth of the cell. The gain related to this bandwidth reduction is applied to the PUSCH and PUCCH C/(I+N): N TX i ic Mi Mi FB - CINR PUSCH PUCCH = CINR PUSCH PUCCH + 10 Log ----------------Mi All FB Final N FB – UL TX i ic
Mi
Min
Where N FB – UL Service N FB – UL N FB – CC for any pixel, subscriber, or mobile Mi in the cell centre of the interfered TX i ic
Mi
Min
cell TXi(ic), and N FB – UL Service N FB – UL N FB – CE for any pixel, subscriber, or mobile Mi in the cell-edge of the interfered cell TXi(ic). Number of frequency blocks in
ICIC mode
Cell centre
Cell edge
TX i ic
No FFR
N FB
Time-switched FFR
N FB
TX i ic
N FB
TX i ic
TX i ic
N FB – CEx
TX ic i
Hard FFR
TX ic i
N FB – CEx TX i ic
Soft FFR
N FB
Partial soft FFR
TX i ic
N FB
TX i ic
N FB – CEx
TX i ic
TX i ic
– N FB – CEx
TX ic
TX ic
N FB – CEx TX ic
i i i – N FB – CE0 + N FB – CE1 + N FB – CE2
TX i ic
TX i ic
TX i ic
N FB – CEx
TX i ic
Where N FB – CEx can be N FB – CE0 , N FB – CE1 , or N FB – CE2 depending on the PSS ID of TXi(ic). Uplink Power Control Adjustment: Once the bandwidth allocation is performed, Atoll continues to work with the C/(I+N) given by the bandwidth Mi
Mi
allocation, i.e., CINR PUSCH PUCCH = CINR PUSCH PUCCH . Final
The pixel, subscriber, or mobile Mi reduces its transmission power so that the PUSCH and PUCCH C/(I+N) from it at its cell is just enough to get the selected bearer.
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If with P
M
i
M
i
M
i
= P Allowed AND CINR PUSCH PUCCH T
TX ic i M i B UL
+ M PC , where T
TX ic i M i B UL
is the bearer selection threshold, from
the reception equipment assigned to the cell TXi(ic), for the bearer selected for the pixel, subscriber, or mobile Mi. The transmission power of Mi is reduced to determine the effective transmission power from the pixel, subscriber, or mobile Mi as follows: Mi Mi Mi TX i ic Mi P Eff = Max P Allowed – CINR PUSCH PUCCH – T M + M PC P Min B i UL
M
M
i
i
CINR PUSCH PUCCH is calculated again using P Eff . Output Mi
•
CINR PUSCH PUCCH : PUSCH and PUCCH C/(I+N) from a pixel, subscriber, or mobile Mi at it serving cell TXi(ic).
•
N FB – UL : Number of frequency blocks used by the pixel, subscriber, or mobile Mi after uplink bandwidth allocation.
•
P Eff : Effective transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
B UL : Bearer assigned to the pixel, subscriber, or mobile Mi in the uplink.
Mi
Mi
Mi
6.4.5 Best Server Determination In LTE, best server refers to a cell ("serving transmitter"-"reference cell" pair) that best covers a pixel, subscriber, or mobile Mi and provides the best service. Input •
TX i ic
C DLRS : Downlink reference signal level received from any cell TXi(ic) at a pixel, subscriber, or mobile Mi as calculated in "Signal Level Calculation (DL)" on page 501 using the terminal and service parameters ( L
Mi
,G
Mi
Mi
Mi
, L Ant , and L Body )
of Mi. TX ic i
•
E DLRS : Received downlink reference signal energy per resource element (RSRP) from any cell TXi(ic) at a pixel, subscriber, or mobile Mi as calculated in "Signal Level Calculation (DL)" on page 501.
•
T RSRP : Minimum RSRP defined for the cell TXi(ic).
•
T Selection : Cell selection threshold defined for the cell TXi(ic).
•
O Individual : Cell individual offset defined for the cell TXi(ic).
•
M HO
TX i ic TX ic i
TX i ic
TX i ic
: Handover margin defined for the cell TXi(ic).
TX i ic
•
p Layer : Priority defined for the layer assigned to for any cell TXi(ic).
•
N SCell
Max – DL
: Maximum number of downlink secondary cells defined for the terminal used by the pixel, subscriber, or
mobile Mi. •
Max – UL
N SCell
: Maximum number of uplink secondary cells defined for the terminal used by the pixel, subscriber, or
mobile Mi. Calculations The serving cell selected for coverage predictions is based on the Standard serving cell selection method. The serving cell selected for Monte Carlo simulations can also be based on the Random method instead of the Standard method. If no serving cell is found for a mobile Mi, it is rejected for “No Coverage”.
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The best server selection for any pixel, subscriber, or mobile Mi BSM is performed as follows: i
•
Standard cell selection based on 3GPP specifications for connected mode mobility: a. Qualification: To qualify as potential servers, cells must fulfill the following requirements: • • •
The cells’ layers must be supported by the pixel, subscriber, or mobile Mi’s service and terminal. The speed defined in the pixel, subscriber, or mobile Mi’s mobility type must be less than or equal to the maximum speed supported by the cells’ layers. The pixel, subscriber, or mobile Mi must be located within the round-trip time distances corresponding to the cells’ PRACH preamble format.
PRACH preamble format
a.
Cyclic prefix
Preamble sequence
Cyclic prefix + preamble sequence
Window size
Guard period
RTT distance
Tsa
Sec.
Ts
Sec.
Sec.
Sec.
Sec.
Metres
0
3168
0.00010
24576
0.00080
0.00090
0.00100
0.00010
14521
1
21024
0.00068
24576
0.00080
0.00148
0.00200
0.00052
77290
2
6240
0.00020
49152
0.00160
0.00180
0.00200
0.00020
29511
3
21024
0.00068
49152
0.00160
0.00228
0.00300
0.00072
107269
4
448
0.00001
4096
0.00013
0.00015
0.00017
0.00002
2811
The basic unit of time in LTE: Ts = 1/(15000 x 2048) seconds. •
For potential serving cells that belong to layers of higher priorities, the RSRP received at the pixel, subscriber, or mobile Mi must be higher than or equal to the cells’ Min RSRP plus the cell selection threshold: TX ic
TX ic
TX ic
i i i E DLRS T RSRP + Max 0 T Selection .
•
For the potential serving cells that belong to the layer of the lowest priority, the RSRP received at the pixel, TX i ic
TX i ic
subscriber, or mobile Mi must be higher than or equal to the cells’ Min RSRP: E DLRS T RSRP . b. Preselection: From the list of cells that qualify as potential servers in step a., the cell that fulfills the following conditions is preselected as the serving cell ( S 0 ): •
The cell belonging to the highest priority layer, and
•
From which the pixel, subscriber, or mobile Mi receives the highest reference signal level or RSRP ( C DLRS or
TX i ic
TX i ic
E DLRS ) according to the defined best server selection criterion. c. Final selection: Among the cells that qualify as potential servers, other than the preselected server ( S 0 ), and fulfill the following condition: TX i ic
TX i ic
S0
S0
S0
E DLRS + O Individual E DLRS + O Individual + M HO Atoll selects as the best server the cell from which the pixel, subscriber, or mobile Mi receives the highest TX i ic
S0
TX i ic
S0
reference signal level or RSRP plus the cell individual offset ( C DLRS + O Individual or E DLRS + O Individual ), according to the defined best server selection criterion. If no cell fulfills the above condition, then the preselcted server ( S 0 ) is selected as the best server. •
Random cell selection: a. Qualification: To qualify as potential servers, cells must fulfill the following requirements: •
536
The cells’ layers must be supported by the pixel, subscriber, or mobile Mi’s service and terminal.
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
• • • •
The cells’ frequency band must be supported by the pixel, subscriber, or mobile Mi’s terminal. The speed defined in the pixel, subscriber, or mobile Mi’s mobility type must be less than or equal to the maximum speed supported by the cells’ layers. The pixel, subscriber, or mobile Mi must be located within the round-trip time distances corresponding to the cells’ PRACH preamble format (see table above). The RSRP received at the pixel, subscriber, or mobile Mi must be higher than or equal to the cells’ Min RSRP: TX ic i
TX ic i
E DLRS T RSRP . b. Final selection: From the list of cells that qualify as potential servers in step a., Atoll keeps only one potential server per layer, i.e., per layer the cell from which the pixel, subscriber, or mobile Mi receives the highest reference signal level or RSRP, and then selects among these cells one cell as the best server at random. For carrier aggregation, Atoll selects multiple servers by processing lists of potential servers according to the Standard or Random cell selection method: LTE users: a. A list of potential serving cells whose cell type includes “LTE” LTE-A users: b. A list of potential primary serving cells whose cell type includes “LTE” and “LTE-A PCell” c. A list of potential secondary serving cells whose may include “LTE-A SCell DL” and “LTE-A SCell UL” Atoll selects the serving cell for LTE users from the list a. and a primary serving cell for LTE-A users from the remaining list b. Once a primary serving cell has been selected, Atoll eliminates the selected cell as well as any other co-channel cell from list c. Here, co-channel cells are cells whose channels overlap the channel being used the primary serving cell. In intra-eNode-B carrier aggregation, at this stage Atoll also eliminates cells belonging to other eNode-Bs than that of the selected primary cell. In group-based carrier aggregation, at this stage Atoll also eliminates cells not belonging to the carrier aggregation groups to which the selected primary cell belongs. You can switch between carrier aggregation modes, using the Atoll.ini file. For more information, see the Administrator Manual. For LTE-A users with a primary serving cell of type “LTE-A PCell” selected from list b., Atoll selects secondary serving cells from list c. This step is carried out until either list c. is empty, or the numbers of downlink or uplink secondary serving cells Max – DL
assigned to the user become equal to the maximum numbers defined in the terminal properties ( N SCell Max – UL
N SCell
and
). Secondary cells are selected based on the reference signal level or RSRP, according to the defined best
server selection criterion. Only secondary cells whose PDSCH C/(I+N) is higher than or equal to the secondary cell DL
activation threshold defined in the terminal reception equipment properties ( T SCell ) are activated for aggregation in downlink. Similarly, only secondary cells whose PDSCH C/(I+N) and PUSCH C/(I+N) are both higher than or equal to the DL
secondary cell activation threshold defined in the terminal and cell reception equipment properties ( T SCell and UL
T SCell ), respectively, are activated for aggregation in uplink. The primary and secondary serving cells once assigned to a mobile do not change during a Monte Carlo simulation. Atoll determines whether the pixel, subscriber, or mobile Mi is in the cell-edge or cell centre of TXi(ic) by calculating the difference between the path loss from the second best server and the best server, and comparing it with the delta path loss threshold defined for the best server of the pixel, subscriber, or mobile Mi. Therefore, 2ndBS M
L Total
i
a
+ 10
pixel,
subscriber,
BS M – 2ndBS M i i Log r O
or
BS M
i
mobile BS M
i
Mi
is
considered
to
be
a
cell
edge BS M
if
i
– L Total L Path , and it is considered to be in cell centre otherwise. Here, L Total is the 2ndBS
total loss from Mi’s best server and L Total
Mi
is the total loss from Mi’s second best server calculated as explained in "Signal
Level Calculation (DL)" on page 453. The second best server for a pixel, subscriber, or mobile Mi is calculated as follows:
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
2ndBS M = TX i ic i
C
BS
rO
M
– 2ndBS i
M
i
©Forsk 2015
TX ic TX i ic i = 2ndBest C DLRS All TX ic DLRS i
is the total channel overlap ratio between the best server and the second best server as calculated in "Co- and BS
Mi
Adjacent Channel Overlaps Calculation" on page 493. L Path is the delta path loss threshold defined for the best server of the pixel, subscriber, or mobile Mi. Output •
BS M : Best serving cell of the pixel, subscriber, or mobile Mi. i
6.4.6 Throughput Calculation Throughputs are calculated in two steps. • • •
Calculation of uplink and downlink total resources in a cell as explained in "Calculation of Total Cell Resources" on page 538. Calculation of uplink and downlink UE capacities as explained in "Calculation UE Capacities" on page 545. Calculation of throughputs as explained in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation" on page 547.
6.4.6.1 Calculation of Total Cell Resources The total amount of resources in a cell is the number of modulation symbols that can be used for data transfer in each frame. The total cell resources can be calculated separately for the downlink and uplink as described in: • •
6.4.6.1.1
"Calculation of Downlink Cell Resources" on page 538. "Calculation of Uplink Cell Resources" on page 543.
Calculation of Downlink Cell Resources Input •
F : Subcarrier width (15 kHz).
•
W FB : Width of a frequency block (180 kHz).
•
N FB – SS PBCH : Number of frequency blocks that carry the SS and the PBCH (6).
•
N Slot SF : Number of slots per subframe (2).
•
D CP
•
N SD Slot : Number of symbol durations per slot (7 is D CP
•
TX ic i
: Cyclic prefix duration defined in TXi(ic) frame configuration or, otherwise, in the global network settings. TX i ic
TX i ic
is Normal, 6 if D CP
is Extended).
TX i ic
N SD – PDCCH : Number of PDCCH symbol durations per subframe defined in TXi(ic) frame configuration or, otherwise, in the global network settings.
•
TX i ic
N FB
: Total number of frequency blocks defined in the frequency bands table for the channel bandwidth used by
the cell TXi(ic). •
TX i ic
N FB – CE0 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 0.
•
TX ic i
N FB – CE1 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 1.
•
TX i ic
N FB – CE2 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 2.
•
TX i ic
N SF – DL : Number of downlink subframes in the frame for the cell TXi(ic). It is equal to 10 for FDD frequency bands, and is determined from the cell’s TDD frame configuration for TDD frequency bands.
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AT330_TRR_E1
•
TX ic i
N TDD – SSF : Number of TDD special subframes (containing DwPTS, GP, and UpPTS) in the frame for the cell TXi(ic). It is equal to 0 for FDD frequency bands, and is determined from the cell’s TDD frame configuration for TDD frequency bands. TX ic i
TX ic i
N SF – DL and N TDD – SSF are determined as follows:
•
TX i ic
TX i ic
Configuration
N SF – DL
N TDD – SSF
FDD
10
0
DSUUU-DSUUU
2
2
DSUUD-DSUUD
4
2
DSUDD-DSUDD
6
2
DSUUU-DSUUD
3
2
DSUUU-DDDDD
6
1
DSUUD-DDDDD
7
1
DSUDD-DDDDD
8
1
TX i ic
N Ant – TX : Number of transmission (downlink) antenna ports defined for the cell TXi(ic).
Calculations In LTE, a resource block (RB) is defined as 1 frequency block by 1 slot. However, schedulers are able to perform resource allocation every subframe (2 slots). 1 frequency block by 1 subframe (2 slots) is called a scheduler resource block (SRB) in the calculations below. The number of modulation symbols (resource elements) per scheduler resource block is calculated as follows: N Sym SRB = N SCa – FB N SD Slot N Slot SF Where N SCa – FB is the number of subcarriers per frequency block calculated as follows: W FB N SCa – FB = --------F The number of modulation symbols (resource elements) corresponding to the DwPTS per scheduler resource block in the TDD special subframes is calculated as follows: DwPTS
DwPTS
N Sym SSF = N SCa – FB N SD SSF DwPTS
Where N SD SSF is the number of DwPTS symbol durations (OFDM symbols) per special subframe, determined from the TDD special subframe configuration according to the 3GPP specifications as follows: Special Subframe Configuration
Cyclic Prefix = Normal DwPTS
GP
N SD SSF
DwPTS
N SD SSF
0
3
1
Cyclic Prefix = Extended UpPTS
DwPTS
GP
UpPTS
N SD SSF
DwPTS
N SD SSF
10
3
8
9
4
8
3
2
10
3
9
2
3
11
2
10
1
4
12
1
3
7
5
3
9
8
2
6
9
3
9
1
7
10
2
8
11
1
GP
N SD SSF
1
2
GP
UpPTS UpPTS
N SD SSF
1
2
The total number of modulation symbols (resource elements) in downlink is calculated as follows: TX i ic
TX i ic
N Sym – DL = N FB
TX i ic
TX i ic
N Sym SRB N SF – DL + N Sym – DwPTS
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks TX ic i
TX ic i
Where N Sym – DwPTS = N FB
©Forsk 2015 TX ic i
DwPTS
N TDD – SSF N Sym SSF TX ic i
The total downlink cell resources, i.e., R DL TX ic i
R DL
TX ic i
TX ic i
, are calculated as follows: TX ic i
TX ic i
TX ic i
= N Sym – DL – O DLRS – O PSS – O SSS – O PBCH – O PDCCH – O DMRS TX i ic
The downlink DwPTS resources, i.e., R DwPTS , are calculated as follows: TX i ic
TX i ic
TX i ic
TX i ic
R DwPTS = N Sym – DwPTS – O DLRS DwPTS – O PDCCH DwPTS TX i ic
Where O DLRS is the overhead corresponding to the downlink reference signals, O PSS is the overhead corresponding to the TX i ic
primary synchronisation signals, O SSS is the overhead corresponding to the secondary synchronisation signals, O PBCH is the TX i ic
overhead corresponding to the physical broadcast channel, and O PDCCH is the overhead corresponding to the physical TX i ic
downlink control channel. O DMRS is the overhead corresponding to the UE-specific reference signals transmitted on the logical antenna port 5 or the demodulation reference signals transmitted using antenna ports 7 and 8 or 7 through 14. These overheads are calculated as follows: Downlink reference signal overhead The downlink reference signal overhead depends on the number of transmission antenna ports: TX ic i
TX ic i
O DLRS = N FB
TX ic i
TX i ic
TX i ic
Where O DLRS DwPTS = N FB
TX ic i
N DLRS SRB
TX ic i
TX ic i
N DLRS SRB N SF – DL + O DLRS DwPTS
8 = 16 24
TX i ic
TX i ic
N DLRS DwPTS N TDD – SSF , TX ic
i if N Ant – TX = 1 TX ic
i if N Ant – TX = 2
,
TX ic
i if N Ant – TX = 4 or 8
TX ic i
And N DLRS DwPTS is determined from the table below: Special Subframe Configuration
0
1
2
540
Cyclic Prefix = Normal DwPTS
N SD SSF
3
9
10
TX i ic
Cyclic Prefix = Extended
TX i ic
N Ant – TX
N DLRS DwPTS
1 2 4
8
8
DwPTS
N SD SSF
TX i ic
TX i ic
N Ant – TX
N DLRS DwPTS
2
1
2
4
2
4
4
8
8
8
8
1
6
1
6
2
12
2
12
4
20
4
20
8
20
8
20
1
6
1
6
2
12
2
12
4
20
4
20
8
20
8
20
3
8
9
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1
Special Subframe Configuration
Cyclic Prefix = Normal DwPTS
N SD SSF
3
4
5
6
7
8
11
12
3
9
10
11
TX ic i
Cyclic Prefix = Extended
TX ic i
N Ant – TX
N DLRS DwPTS
1
6
2
12
4
20
8
20
1
8
2
16
4
24
8
24
1
2
2
4
4
8
8
8
1
6
2
12
4
20
8
20
1
6
2
12
4
20
8
20
1
6
2
12
4
20
8
20
DwPTS
N SD SSF
10
3
8
9
TX ic i
TX ic i
N Ant – TX
N DLRS DwPTS
1
8
2
16
4
24
8
24
1
2
2
4
4
8
8
8
1
6
2
12
4
20
8
20
1
6
2
12
4
20
8
20
PSS and SSS overhead The primary and secondary synchonisation signals are transmitted on 1 symbol duration each in the 1st and the 6th downlink subframes, over the centre 6 frequency blocks. Therefore, O PSS = 2 N FB – SS PBCH N SCa – FB = 144 symbols O SSS = 2 N FB – SS PBCH N SCa – FB = 144 symbols PBCH overhead The physical broadcast channel is transmitted on four symbol durations in the 1st downlink subframe over the center 6 frequency blocks. The physical broadcast channel overlaps with the downlink reference signals, therefore, some downlink reference signal modulation symbols are subtracted: 216 for extended cyclic prefix 240 for normal cyclic prefix PDCCH overhead The physical downlink control channel can be transmitted over up to 4 symbol durations in each subframe. The number of symbol durations for the PDCCH is defined in the global network settings. The PDCCH overlaps some downlink reference signal symbols. These downlink reference signal symbols are subtracted from the PDCCH overhead: TX ic
i if N SD – PDCCH = 0 : TX i ic
O PDCCH = 0
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks TX ic
©Forsk 2015 TX ic
i i if N SD – PDCCH = 1 AND N Ant – TX 2 : TX ic
TX ic
TX ic
i i i O PDCCH = N SD – PDCCH N SCa – FB – 4 N FB TX ic i
Where O PDCCH DwPTS =
TX ic i
TX ic i
N SF – DL + O PDCCH DwPTS
TX ic
TX ic
i N i SD – PDCCH N SCa – FB – 4 N FB
TX ic i
N TDD – SSF
Otherwise: TX ic
TX ic
TX ic
TX ic
i i i i O PDCCH = N SD – PDCCH N SCa – FB – 2 Min 4 N Ant – TX N FB TX ic
TX i ic
TX i ic
N SF – DL + O PDCCH DwPTS
TX ic
TX ic
TX ic
i i i i Where O PDCCH DwPTS = Min 2 N SD – PDCCH N SCa – FB – 2 Min 4 N Ant – TX N FB
TX i ic
N TDD – SSF
UE-specific and demodulation reference signal overhead UE-specific reference signals are transmitted on the logical antenna port 5, DMRS are transmitted on antenna ports 7 and 8, or on 7 through 14. TX i ic
Without smart antennas and MIMO: O DMRS = 0 TX i ic
TX i ic
With smart antennas and without MIMO: O DMRS = 12 N FB TX i ic
TX i ic
With smart antennas and with MIMO: O DMRS = 24 N FB
TX i ic
N SF – DL TX i ic
N SF – DL TX i ic
TX i ic
TX i ic
Without smart antennas and with SU-MIMO or MU-MIMO and N Ant – TX 4 : O DMRS = 24 N FB TX ic i
Once R DL
is known, it is scaled down according to the ICIC mode used by the cell TXi(ic) depending on whether the
downlink cell resources are being calculated for a cell-centre or cell-edge pixel, subscriber, or mobile. TX i ic
R DL
TX i ic
= R DL
ICIC
ABS
f Scaling f Scaling
ICIC
f Scaling is calculated as follows for the different ICIC modes: ICIC
ICIC cell resource scaling factor f Scaling for
ICIC mode
Cell centre
Cell edge
1
1
Time-switched FFR
1
N FB – CEx -------------------TX i ic N FB
Hard FFR
N FB – CEx -------------------TX i ic N FB
Soft FFR
N FB – N FB – CEx -----------------------------------------TX ic i N FB
Partial soft FFR
N FB – N FB – CE0 + N FB – CE1 + N FB – CE2 -----------------------------------------------------------------------------------------------------TX i ic N FB
No FFR
TX i ic
TX i ic
TX ic i
TX i ic
TX ic i
TX ic i
TX i ic
TX ic i
TX i ic
N FB – CEx -------------------TX i ic N FB
TX ic i
TX i ic
TX ic i
TX ic i
N FB – CEx -------------------TX ic i N FB TX i ic
Where N FB – CEx can be N FB – CE0 , N FB – CE1 , or N FB – CE2 depending on the PSS ID of TXi(ic).
542
TX i ic
N SF – DL
TX i ic
N FB – CEx -------------------TX i ic N FB
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1 ABS
f Scaling is calculated as follows: •
Method 1: ABS Patterns Used Only at Cell Edges
ABS
f Scaling
•
1 Cell centre TX i ic TX i ic TX i ic TX i ic TX i ic R DL – R DwPTS + SFP SSF R DwPTS SFP DL = ------------------------------------------------------------------------------------------------------------------------------------------------1 1 - Cell edge TX i ic 80 R DL
Method 2: ABS Patterns Used Throughout the Cell TX i ic
ABS
SFPDL
TX i ic
R DL
TX ic
i – R DwPTS +
TX i ic
SFPSSF
TX ic
i R DwPTS
1 1 f Scaling = ------------------------------------------------------------------------------------------------------------------------------------------------TX i ic 80 R DL TX i ic
For more information on SFP DL
TX i ic
and SFP SSF
, see "Subframe Pattern Collision Calculation" on page 497.
Output •
6.4.6.1.2
TX ic i
R DL
: Amount of downlink resources in the cell TXi(ic).
Calculation of Uplink Cell Resources Input •
F : Subcarrier width (15 kHz).
•
W FB : Width of a frequency block (180 kHz).
•
N Slot SF : Number of slots per subframe (2).
•
D CP
•
N SD Slot : Number of symbol durations per slot (7 is D CP
TX i ic
: Cyclic prefix duration defined in TXi(ic) frame configuration or, otherwise, in the global network settings. TX i ic
TX i ic
is Normal, 6 if D CP
is Extended).
TX i ic
•
N FB – PUCCH : Average number of PUCCH frequency blocks per frame defined in TXi(ic) frame configuration or, otherwise, in the global network settings.
•
N FB
TX i ic
: Total number of frequency blocks defined in the frequency bands table for the channel bandwidth used by
the cell TXi(ic). •
TX i ic
N FB – CE0 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 0.
•
TX i ic
N FB – CE1 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 1.
•
TX i ic
N FB – CE2 : Number of cell-edge frequency blocks defined in the frame configurations table for the channel bandwidth used by the cell TXi(ic) and PSS ID 2.
•
TX ic i
N SF – UL : Number of uplink subframes in the frame for the cell TXi(ic). It is equal to 10 for FDD frequency bands, and is determined from the cell’s TDD frame configuration for TDD frequency bands.
•
TX ic i
N TDD – SSF : Number of TDD special subframes (containing DwPTS, GP, and UpPTS) in the frame for the cell TXi(ic). It is equal to 0 for FDD frequency bands, and is determined from the cell’s TDD frame configuration for TDD frequency bands. TX i ic
TX i ic
N SF – UL and N TDD – SSF are determined as follows:
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TX ic i
Configuration
N SF – UL
N TDD – SSF
FDD
10
0
DSUUU-DSUUU
6
2
DSUUD-DSUUD
4
2
DSUDD-DSUDD
2
2
DSUUU-DSUUD
5
2
DSUUU-DDDDD
3
1
DSUUD-DDDDD
2
1
DSUDD-DDDDD
1
1
UpPTS is used for SRS (sounding reference signals) if the UpPTS duration is 1 OFDM symbol, and for SRS and PRACH if the UpPTS duration is 2 OFDM symbols. Therefore, the uplink cell capacity can be determined without considering the UpPTS symbols. Calculations In LTE, a resource block (RB) is defined as 1 frequency block by 1 slot. However, schedulers are able to perform resource allocation every subframe (2 slots). 1 frequency block by 1 subframe (2 slots) is called a scheduler resource block (SRB) in the calculations below. The number of modulation symbols (resource elements) per resource block is calculated as follows: N Sym SRB = N SCa – FB N SD Slot N Slot SF Where N SCa – FB is the number of subcarriers per frequency block calculated as follows: W FB N SCa – FB = --------F The total number of modulation symbols (resource elements) in uplink is calculated as follows: TX ic
TX ic
i i N Sym – UL = N FB
TX ic
TX ic
i i – N FB – PUCCH N Sym SRB N SF – UL TX i ic
The total uplink cell resources, i.e., R UL TX i ic
R UL
TX i ic
TX i ic
, are calculated as follows:
TX i ic
= N Sym – UL – O ULSRS – O ULDRS TX i ic
TX i ic
Where O ULSRS is the overhead corresponding to the uplink sounding reference signals, and O ULDRS is the overhead corresponding to the uplink demodulation reference signals. These control channel overheads are calculated as follows: Calculations of uplink control channel overheads The uplink sounding reference signals are transmitted on 1 symbol duration in each uplink subframe. Therefore, TX i ic TX i ic N SCa – FB - N Sym O ULSRS = --------------------– UL N Sym SRB
The uplink demodulation reference signals are transmitted on two symbol durations in each uplink subframe. Therefore, TX i ic TX i ic N SCa – FB - N Sym O ULDRS = 2 --------------------– UL N Sym SRB TX i ic
Once R UL
is known, it is scaled down according to the ICIC mode used by the cell TXi(ic) depending on whether the uplink
cell resources are being calculated for a cell-centre or cell-edge pixel, subscriber, or mobile. TX i ic
R UL
ICIC
TX i ic
= R UL
ICIC
ABS
f Scaling f Scaling
f Scaling is calculated as follows for the different ICIC modes:
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ICIC
ICIC cell resource scaling factor f Scaling for
ICIC mode
Cell centre
Cell edge
1
1
Time-switched FFR
1
N FB – CEx -------------------TX i ic N FB
Hard FFR
N FB – CEx -------------------TX i ic N FB
Soft FFR
N FB – N FB – CEx -----------------------------------------TX i ic N FB
Partial soft FFR
N FB – N FB – CE0 + N FB – CE1 + N FB – CE2 -----------------------------------------------------------------------------------------------------TX i ic N FB
No FFR
TX ic i
TX i ic
TX i ic
TX ic i
TX i ic
TX i ic
TX ic i
TX i ic
TX i ic
N FB – CEx -------------------TX i ic N FB
TX i ic
TX ic i
TX i ic
N FB – CEx -------------------TX i ic N FB TX ic i
TX i ic
N FB – CEx -------------------TX i ic N FB
TX i ic
Where N FB – CEx can be N FB – CE0 , N FB – CE1 , or N FB – CE2 depending on the PSS ID of TXi(ic). ABS
f Scaling is calculated as follows: •
Method 1: ABS Patterns Used Only at Cell Edges
ABS
f Scaling
•
1 Cell centre TX i ic = SFP UL 1 ------------------------------ Cell edge 80
Method 2: ABS Patterns Used Throughout the Cell TX ic i
SFPUL
ABS
1 f Scaling = ----------------------------80 TX i ic
For more information on SFP UL
, see "Subframe Pattern Collision Calculation" on page 497.
Output •
TX i ic
R UL
: Amount of uplink resources in the cell TXi(ic).
6.4.6.2 Calculation UE Capacities The UE category parameters define the maximum throughput that can be supported by a UE in downlink and uplink. The UE capacities are calculated for the downlink and uplink as described in: • •
6.4.6.2.1
"Calculation of Downlink UE Capacity" on page 545. "Calculation of Uplink UE Capacity" on page 546.
Calculation of Downlink UE Capacity Input •
D Frame : Frame duration.
•
N TBB TTI : Maximum number of transport block bits per TTI (subframe) in downlink defined for a UE category.
•
N SF – DL : Number of downlink subframes in the frame for the cell TXi(ic). It is equal to 10 for FDD frequency bands, and
Max – DL TX i ic
is determined from the cell’s TDD frame configuration for TDD frequency bands.
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TX ic i
•
N TDD – SSF : Number of TDD special subframes (containing DwPTS, GP, and UpPTS) in the frame for the cell TXi(ic). It is equal to 0 for FDD frequency bands, and is determined from the cell’s TDD frame configuration for TDD frequency bands. TX ic i
TX ic i
N SF – DL and N TDD – SSF are determined as follows: TX i ic
TX i ic
Configuration
N SF – DL
N TDD – SSF
FDD
10
0
DSUUU-DSUUU
2
2
DSUUD-DSUUD
4
2
DSUDD-DSUDD
6
2
DSUUU-DSUUD
3
2
DSUUU-DDDDD
6
1
DSUUD-DDDDD
7
1
DSUDD-DDDDD
8
1
Calculations In LTE, the maximum throughput that can be supported by a user equipment is defined through its UE category parameter Transport Block Size. This is the maximum number of transport block bits that the UE can carry per subframe. The downlink UE capacity in terms of the maximum throughput supported by a UE in downlink is calculated as follows: TX ic
Max TP UE – DL
=
Max – DL N TBB TTI
TX ic
i N i SF – DL + N TDD – SSF -------------------------------------------------- D Frame
The maximum transport block sizes defined by the 3GPP for different UE categories correspond to the following maximum throughput capacities in FDD: UE Category
1
2
3
4
5
6
7
8
Max – DL
10296
51024
102048
150752
299552
301504
301504
2998560
Max
10.296
51.024
102.048
150.752
299.552
301.504
301.504
2998.560
N TBB TTI (bits/TTI) TP UE – DL (Mbps) Output •
6.4.6.2.2
Max
TP UE – DL : Maximum downlink throughput capacity of a UE category.
Calculation of Uplink UE Capacity Input •
D Frame : Frame duration.
•
N TBB TTI : Maximum number of transport block bits per TTI (subframe) in uplink defined for a UE category.
•
N SF – UL : Number of uplink subframes in the frame for the cell TXi(ic). It is equal to 10 for FDD frequency bands, and
Max – UL TX ic i
is determined from the cell’s TDD frame configuration for TDD frequency bands. •
TX ic i
N TDD – SSF : Number of TDD special subframes (containing DwPTS, GP, and UpPTS) in the frame for the cell TXi(ic). It is equal to 0 for FDD frequency bands, and is determined from the cell’s TDD frame configuration for TDD frequency bands. TX i ic
TX i ic
N SF – UL and N TDD – SSF are determined as follows:
546
TX i ic
TX i ic
Configuration
N SF – UL
N TDD – SSF
FDD
10
0
DSUUU-DSUUU
6
2
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks
AT330_TRR_E1 TX ic i
TX ic i
Configuration
N SF – UL
N TDD – SSF
DSUUD-DSUUD
4
2
DSUDD-DSUDD
2
2
DSUUU-DSUUD
5
2
DSUUU-DDDDD
3
1
DSUUD-DDDDD
2
1
DSUDD-DDDDD
1
1
Calculations In LTE, the maximum throughput that can be supported by a user equipment is defined through its UE category parameter Transport Block Size. This is the maximum number of transport block bits that the UE can carry per subframe. The uplink UE capacity in terms of the maximum throughput supported by a UE in uplink is calculated as follows: Max TP UE – UL
=
Max – UL N TBB TTI
TX ic i
N SF – UL ----------------D Frame
The maximum transport block sizes defined by the 3GPP for different UE categories correspond to the following maximum throughput capacities in FDD: UE Category
1
2
3
4
5
6
7
8
Max – UL
5160
25456
51024
51024
75376
51024
102048
1497760
Max
5.16
25.456
51.024
51.024
75.376
51.024
102.048
1497.760
N TBB TTI (bits/TTI) TP UE – UL (Mbps) Output •
Max
TP UE – UL : Maximum uplink throughput capacity of a UE category.
6.4.6.3 Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation Channel throughputs are calculated for the entire channel resources allocated to the pixel, subscriber, or mobile Mi. Cell capacities are similar to channel throughputs but upper-bound by the maximum downlink and uplink traffic loads. Allocated bandwidth throughputs are calculated for the number of used frequency blocks in uplink allocated to the pixel, subscriber, or mobile Mi. Per-user throughputs are calculated by dividing the downlink cell capacities or uplink allocated bandwidth throughputs by the average number of downlink or uplink users defined for the cell, respectively. Input TX i ic
•
TL DL – Max : Maximum downlink traffic load for the cell TXi(ic).
•
TL UL – Max : Maximum uplink traffic load for the cell TXi(ic).
•
R DL
TX ic i
TX i ic
: Amount of downlink resources in the cell TXi(ic) as calculated in "Calculation of Total Cell Resources" on
page 538. •
TX i ic
•
: Amount of uplink resources in the cell TXi(ic) as calculated in "Calculation of Total Cell Resources" on page 538. M : Bearer efficiency (bits/symbol) of the bearer assigned to the pixel, subscriber, or mobile Mi in the downlink in
•
"C/(I+N) and Bearer Calculation (DL)" on page 518. M : Bearer efficiency (bits/symbol) of the bearer assigned to the pixel, subscriber, or mobile Mi in the uplink in "C/
•
(I+N) and Bearer Calculation (UL)" on page 532. D Frame : Frame duration.
•
T SU – MIMO – UL : SU-MIMO threshold defined in the reception equipment of the cell TXi(ic).
R UL
i B DL
i B UL
TX i ic
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i
•
T SU – MIMO – DL : SU-MIMO threshold defined in the reception equipment of the pixel, subscriber, or mobile Mi.
•
T MU – MIMO – UL : MU-MIMO threshold defined in the reception equipment of the cell TXi(ic).
•
T MU – MIMO – DL : MU-MIMO threshold defined in the reception equipment of the pixel, subscriber, or mobile Mi.
•
G MU – MIMO – UL : Average number of co-scheduled MU-MIMO users in uplink for the cell TXi(ic).
•
G MU – MIMO – DL : Average number of co-scheduled MU-MIMO users in downlink for the cell TXi(ic).
•
i i BLER BDL : Downlink block error rate read from the BLER vs. CINR PDSCH graph available in the reception equipment
TX ic i TX ic i
TX i ic TX i ic
TX ic
M
assigned to the terminal used by the pixel, subscriber, or mobile Mi. •
M
M
i i BLER BUL : Uplink block error rate read from the BLER vs. CINR PUSCH PUCCH graph available in the reception equipment assigned to the cell TXi(ic). DL
•
T SCell : Secondary cell activation threshold of the reception equipment assigned to the pixel, subscriber, or mobile Mi.
•
T SCell : Secondary cell activation threshold of the reception equipment assigned to the cell TXi(ic).
•
f TP – Scaling : Throughput scaling factor defined in the properties of the service used by the pixel, subscriber, or mobile
UL
Mi
Mi. M
i
•
TP Offset : Throughput offset defined in the properties of the service used by the pixel, subscriber, or mobile Mi.
•
N FB
TX i ic
: Number of frequency blocks, defined in the frequency bands table, for the channel bandwidth used by the
cell TXi(ic). •
Mi
N FB – UL : Number of frequency blocks used by the pixel, subscriber, or mobile Mi after uplink bandwidth allocation as calculated in "C/(I+N) and Bearer Calculation (UL)" on page 532. TX ic i
•
N Users – DL : Number of users connected to the cell TXi(ic) in downlink.
•
N Users – UL : Number of users connected to the cell TXi(ic) in uplink.
TX i ic
Calculations Downlink: TX ic i
•
Mi
R DL
Mi B DL
Peak RLC Channel Throughput: CTP P – DL = --------------------------------D Frame In the above formula, the actual value of D Frame is used to calculate the channel throughput for coverage predictions, while D Frame = 1 sec for Monte Carlo simulations. TX i ic
For proportional fair schedulers, the channel throughput is increased by the multi-user diversity gain G MUG – DL read Mi
from the scheduler properties for the bearer B DL , Mobility M i , and the number of users connected to the cell in downlink. TX i ic
R DL Mi
B
Mi
TX ic
i DL CTP P – DL = -------------------------------- G MUG – DL D Frame TX i ic
Mi
Max
G MUG – DL = 1 if CINR PDSCH CINR MUG If the multi-user diversity gain for the exact value of the number of connected users is not available in the graph, it is interpolated from the gain values available for the numbers of users just less than and just greater than the actual number of users. MIMO – SU-MIMO Gain:
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If the cell supports MIMO, and according to the Mi diversity mode depending on the SU-MIMO threshold and criterion, Max – M
i
the SU-MIMO gain, G SU – MIMO – DL , corresponding to the bearer is applied to its efficiency. The gain is read from the TX ic i
M
i
properties of the reception equipment assigned to the pixel, subscriber, or mobile Mi for N Ant – TX , N Ant – RX , M
i Mobility M i , BLER B DL .
Atoll also takes into account the SU-MIMO Gain Factor f SU – MIMO defined for the clutter class where the pixel, subscriber, or mobile Mi is located.
Mi
=
B DL
Max – M i
Mi
B DL
1 + f SU – MIMO G SU – MIMO – DL – 1
If the Max SU-MIMO Gain for the exact value of the C/(I+N) is not available in the table, it is interpolated from the gain values available for the C/(I+N) just less than and just greater than the actual C/(I+N). MIMO – MU-MIMO Gain (for throughput coverage predictions): If the cell supports MU-MIMO, and according to the Mi diversity mode depending on the MU-MIMO threshold and TX i ic
criterion, the MU-MIMO gain, G MU – MIMO – DL , which is the average number of co-scheduled users, is applied to the channel throughput. Mi
Mi
TX i ic
CTP P – DL = CTP P – DL G MU – MIMO – DL •
M
M
M
i i i Effective RLC Channel Throughput: CTP E – DL = CTP P – DL 1 – BLER B DL Mi
Mi f TP – Scaling - – TP Offset = CTP E – DL -----------------------100
Mi
Mi
•
Application Channel Throughput: CTP A – DL
•
Peak RLC Cell Capacity: Cap P – DL = CTP P – DL TL DL – Max
•
i i i Effective RLC Cell Capacity: Cap E – DL = Cap P – DL 1 – BLER B DL
•
Mi
TX i ic
Mi
M
M
Mi
Application RLC Capacity: Cap A – DL
M
Mi
Mi f TP – Scaling - – TP Offset = Cap E – DL -----------------------100 Mi
Mi
•
•
•
Mi Cap P – DL Peak RLC Throughput per User: PUTP P – DL = ----------------------TX i ic N Users – DL
Effective RLC Throughput per User:
Application Throughput per User:
M
i PUTP E – DL
M
i PUTP A – DL
Mi
Cap E – DL = ----------------------TX i ic N Users – DL
=
M
i PUTP E – DL
Mi
M f TP – Scaling i - – TP Offset -----------------------100
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Carrier Aggregation: Aggregated throughputs are calculated by summing the throughputs from each serving cell taking part in carrier aggregation for any LTE-A pixel, subscriber, or mobile. If the sum of the throughputs exceeds the maximum throughput supported by the UE category, the aggregated throughput is scaled down by the following ratio: Mi Max CTP P – DL Min TP UE – DL TX i ic r = --------------------------------------------------------------------------Mi CTP P – DL
TX i ic
Only secondary cells whose PDSCH C/(I+N) is higher than or equal to the secondary cell DL
activation threshold ( T SCell ) defined in the terminal reception equipment properties are activated for aggregation. Uplink: TX i ic
•
Peak RLC Channel Throughput:
M
i CTP P – UL
R UL
Mi B UL
= --------------------------------D Frame
In the above formula, the actual value of D Frame is used to calculate the channel throughput for coverage predictions, while D Frame = 1 sec for Monte Carlo simulations. TX i ic
For proportional fair schedulers, the channel throughput is increased by the multi-user diversity gain G MUG – UL read Mi
from the scheduler properties for the bearer B UL , Mobility M i , and the number of users connected to the cell in uplink. TX i ic
R UL Mi
B
Mi
TX ic
i UL CTP P – UL = -------------------------------- G MUG – UL D Frame TX i ic
Mi
Max
G MUG – UL = 1 if CINR PUSCH PUCCH CINR MUG If the multi-user diversity gain for the exact value of the number of connected users is not available in the graph, it is interpolated from the gain values available for the numbers of users just less than and just greater than the actual number of users. MIMO – SU-MIMO Gain: If the cell supports MIMO, and according to the Mi diversity mode depending on the SU-MIMO threshold and criterion, Max – TX i ic
the SU-MIMO gain, G SU – MIMO – UL , corresponding to the bearer is applied to its efficiency. The gain is read from the M
TX ic
M
i i i properties of the reception equipment assigned to the TXi(ic) for N Ant – RX , N Ant – TX , Mobility M i , BLER B UL .
Atoll also takes into account the SU-MIMO Gain Factor f SU – MIMO defined for the clutter class where the pixel, subscriber, or mobile Mi is located.
Mi
B UL
=
Max – TX i ic
Mi
B UL
1 + f SU – MIMO G SU – MIMO – UL – 1
If the Max SU-MIMO Gain for the exact value of the C/(I+N) is not available in the table, it is interpolated from the gain values available for the C/(I+N) just less than and just greater than the actual C/(I+N).
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MIMO – MU-MIMO Gain (for throughput coverage predictions): If the cell supports MU-MIMO, and according to the Mi diversity mode depending on the MU-MIMO threshold and TX ic i
criterion, the MU-MIMO gain, G MU – MIMO – UL , which is the average number of co-scheduled users, is applied to the channel throughput. M
i
M
i
TX ic i
CTP P – UL = CTP P – UL G MU – MIMO – UL •
M
M
M
i i i Effective RLC Channel Throughput: CTP E – UL = CTP P – UL 1 – BLER B UL Mi
Mi
Mi f TP – Scaling - – TP Offset = CTP E – UL -----------------------100 Mi
•
Application Channel Throughput: CTP A – UL
•
Peak RLC Cell Capacity: Cap P – UL = CTP P – UL TL UL – Max
•
i i i Effective RLC Cell Capacity: Cap E – UL = Cap P – UL 1 – BLER B UL
•
M
M
i
M
Mi
Application Cell Capacity: Cap A – UL
TX ic i
i
M
M
Mi
Mi f TP – Scaling - – TP Offset = Cap E – UL -----------------------100 Mi
M
•
•
i
Mi Mi N FB – UL Peak RLC Allocated Bandwidth Throughput: ABTP P – UL = CTP P – UL ----------------TX ic i N FB M
M
M
i i i Effective RLC Allocated Bandwidth Throughput: ABTP E – UL = ABTP P – UL 1 – BLER B UL Mi
Mi
Mi f TP – Scaling - – TPOffset = ABTP E – UL -----------------------100 Mi
•
Application Allocated Bandwidth Throughput: ABTPA – UL
•
Cap M i M M i P – UL - ABTPP –i UL Peak RLC Throughput per User: PUTP P – UL = Min ----------------------TX ic i N Users – UL
•
Cap Mi Mi M E – UL - ABTP E –i UL Effective RLC Throughput per User: PUTP E – UL = Min ----------------------TX ic i N Users – UL
•
Mi
Application Throughput per User: PUTP A – UL
Mi
Mi f TP – Scaling - – TP Offset = PUTP E – UL -----------------------100 Mi
Carrier Aggregation: Aggregated throughputs are calculated by summing the throughputs from each serving cell taking part in carrier aggregation for any LTE-A pixel, subscriber, or mobile. If the sum of the throughputs exceeds the maximum throughput supported by the UE category, the aggregated throughput is scaled down by the following ratio: Mi Max Min TP UE – UL CTP P – UL TX i ic r = --------------------------------------------------------------------------Mi CTP P – UL
TX i ic
Only secondary cells whose PDSCH C/(I+N) is higher than or equal to the secondary cell DL
activation threshold ( T SCell ) defined in the terminal reception equipment properties and UL
PUSCH C/(I+N) is higher than or equal to the secondary cell activation threshold ( T SCell ) defined in the cell reception equipment properties are activated for aggregation.
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Output M
i
•
CTP P – DL : Downlink peak RLC channel throughput at the pixel, subscriber, or mobile Mi.
•
CTP E – DL : Downlink effective RLC channel throughput at the pixel, subscriber, or mobile Mi.
•
CTP A – DL : Downlink application channel throughput at the pixel, subscriber, or mobile Mi.
•
Cap P – DL : Downlink peak RLC cell capacity at the pixel, subscriber, or mobile Mi.
•
Cap E – DL : Downlink effective RLC cell capacity at the pixel, subscriber, or mobile Mi.
•
Cap A – DL : Downlink application cell capacity at the pixel, subscriber, or mobile Mi.
•
PUTP P – DL : Downlink peak RLC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP E – DL : Downlink effective RLC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP A – DL : Downlink application throughput per user at the pixel, subscriber, or mobile Mi.
•
CTP P – UL : Uplink peak RLC channel throughput at the pixel, subscriber, or mobile Mi.
•
CTP E – UL : Uplink effective RLC channel throughput at the pixel, subscriber, or mobile Mi.
•
CTP A – UL : Uplink application channel throughput at the pixel, subscriber, or mobile Mi.
•
Cap P – UL : Uplink peak RLC cell capacity at the pixel, subscriber, or mobile Mi.
•
Cap E – UL : Uplink effective RLC cell capacity at the pixel, subscriber, or mobile Mi.
•
Cap A – UL : Uplink application cell capacity at the pixel, subscriber, or mobile Mi.
•
ABTP P – UL : Uplink peak RLC allocated bandwidth throughput at the pixel, subscriber, or mobile Mi.
•
ABTP E – UL : Uplink effective RLC allocated bandwidth throughput at the pixel, subscriber, or mobile Mi.
•
ABTP A – UL : Uplink application allocated bandwidth throughput at the pixel, subscriber, or mobile Mi.
•
PUTP P – UL : Uplink peak RLC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP E – UL : Uplink effective RLC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP A – UL : Uplink application throughput per user at the pixel, subscriber, or mobile Mi.
M
i
Mi M
i
Mi Mi
Mi Mi M
i
Mi Mi Mi
Mi M
i
Mi
Mi Mi Mi
Mi Mi Mi
6.4.7 Scheduling and Radio Resource Management Atoll LTE module includes a number of scheduling methods which can be used for scheduling and radio resource allocation during Monte Carlo simulations. These resource allocation algorithms are explained in "Scheduling and Radio Resource Allocation" on page 552 and the calculation of user throughputs is explained in "User Throughput Calculation" on page 561.
6.4.7.1 Scheduling and Radio Resource Allocation Input
552
TX ic i
•
TL DL – Max : Maximum downlink traffic load for the cell TXi(ic).
•
TL UL – Max : Maximum uplink traffic load for the cell TXi(ic).
•
N Users – Max : Maximum number of users defined for the cell TXi(ic).
•
p QCI : QCI priority of the service accessed by a mobile Mi.
•
p Service : User-defined priority of the service accessed by a mobile Mi.
TX i ic
TX i ic
Mi Mi
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i
•
TPD Min – DL : Downlink minimum throughput demand for the service accessed by a mobile Mi.
•
TPD Min – UL : Uplink minimum throughput demand for the service accessed by a mobile Mi.
•
TPD Max – DL : Downlink maximum throughput demand for the service accessed by a mobile Mi.
•
TPD Max – UL : Uplink maximum throughput demand for the service accessed by a mobile Mi.
•
G MU – MIMO – UL : Average number of co-scheduled MU-MIMO users in uplink for the cell TXi(ic).
•
G MU – MIMO – DL : Average number of co-scheduled MU-MIMO users in downlink for the cell TXi(ic).
•
•
Calculation (DL)" on page 518. M : Bearer efficiency (bits/symbol) of the bearer assigned to the mobile Mi in the uplink in "C/(I+N) and Bearer
•
Calculation (UL)" on page 532. : Bearer efficiency (bits/symbol) of the highest bearer of the service being used by the mobile Mi in the M
•
downlink. M
M M
i i
Mi
TX i ic TX i ic
Mi B DL
: Bearer efficiency (bits/symbol) of the bearer assigned to the mobile Mi in the downlink in "C/(I+N) and Bearer
i B UL
i B DL – Highest
i B UL – Highest
: Bearer efficiency (bits/symbol) of the highest bearer of the service being used by the mobile Mi in the
uplink. •
•
M
TX ic
M
M
i i BLER B DL : Downlink block error rate read from the BLER vs. CINR PDSCH graph available in the reception equipment assigned to the terminal used by the mobile Mi. i i BLER B UL : Uplink block error rate read from the BLER vs. CINR PUSCH PUCCH graph available in the reception equipment assigned to the cell TXi(ic). DL
•
T SCell : Secondary cell activation threshold of the reception equipment assigned to the mobile Mi.
•
T SCell : Secondary cell activation threshold of the reception equipment assigned to the cell TXi(ic).
•
f TP – Scaling : Throughput scaling factor defined in the properties of the service used by the mobile Mi.
•
TP Offset : Throughput offset defined in the properties of the service used by the mobile Mi.
•
CTP P – DL : Downlink peak RLC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on
UL
Mi
M
i
Mi
page 538. •
Mi
CTP E – DL : Downlink effective RLC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on page 538.
•
Mi
CTP P – UL : Uplink peak RLC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on page 538.
•
Mi
CTP E – UL : Uplink effective RLC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on page 538.
•
Mi
ABTP P – UL : Uplink peak RLC allocated bandwidth throughput at the mobile Mi as calculated in "Throughput Calculation" on page 538.
•
Mi
ABTP E – UL : Uplink effective RLC allocated bandwidth throughput at the mobile Mi as calculated in "Throughput Calculation" on page 538.
•
Max
TP UE – DL : Maximum downlink throughput capacity of the UE category of the mobile Mi as calculated in "Calculation of Downlink UE Capacity" on page 545.
•
Max
TP UE – UL : Maximum uplink throughput capacity of the UE category of the mobile Mi as calculated in "Calculation of Uplink UE Capacity" on page 546.
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Calculations The following calculations are described for any cell TXi(ic) containing the users Mi for which it is the best server. Mobile Selection: TX ic i
The scheduler selects N Users mobiles for the scheduling and RRM process. If the Monte Carlo user distribution has generated TX i ic
a number of users which is less than N Users – Max , the scheduler keeps all the mobiles generated for the cell TXi(ic). TX ic
TX ic
TX ic
i i i N Users = Min N Users – Max N Users – Generated Sel
For a cell, mobiles M i
TX ic i
N Users are selected for RRM by the scheduler.
Calculation of Actual Minimum and Maximum Throughput Demands: If the service maximum throughput demand downgrading is active (for more information, see the Administrator Manual), the maximum throughput demand of each user will be downgraded as follows:
Downlink:
Sel Mi TPD Max – DL
Sel Mi
Uplink: TPD Max – UL
Sel Mi Sel Sel Mi Mi B DL = Max TPD Min – DL TPD Max – DL ------------------------------ Sel Mi B DL – Highest
Sel Mi Sel Sel Mi Mi B UL = Max TPD Min – UL TPD Max – UL ------------------------------- Sel Mi B UL – Highest
Then, depending on the selected target throughput of the scheduler assigned to the cell TXi(ic), the actual minimum and maximum throughput demands can be considered as the peak RLC, effective RLC, or application throughput. Therefore: •
Target Throughput = Peak RLC Throughput M
Sel i
M
Sel i
Downlink: TPD Min – DL , TPD Max – DL Sel
Sel
Mi Mi Mi Uplink: TPD Min – UL , Min TPD Max – UL ABTP P – UL
•
Target Throughput = Effective RLC Throughput Sel Mi
Downlink: TPD Min – DL
Sel Mi
Sel Mi
Sel
Mi TPD Min – DL TPD Max – DL = --------------------------------------------- , TPD Max – DL = --------------------------------------------Sel Sel Mi Mi 1 – BLER B DL 1 – BLER BDL Sel
Sel Mi
Sel i TPD Min – UL M
Sel Mi
Uplink: TPD Min – UL = ---------------------------------------------- , TPD Max – UL Sel Mi 1 – BLER B UL •
Target Throughput = Application Throughput
Downlink:
Sel Mi Mi Sel TPD i Min – DL + TP Offset TPD Min – DL = -----------------------------------------------------------------------------Sel Mi Mi M
1 – BLER B DL f TP – Scaling
554
Mi Mi Min TPD Max – UL ABTP P – UL = ------------------------------------------------------------------------Sel Mi 1 – BLER B UL
,
Sel i TPD Max – DL = M
Sel Mi
Mi
TPD Max – DL + TP Offset ----------------------------------------------------------------------------Sel Mi Mi 1 – BLER B DL f TP – Scaling
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Uplink:
Sel M M Sel i i TPD i Min – UL + TP Offset TPD Min – UL = -----------------------------------------------------------------------------Sel Mi Mi 1 – BLER BUL f TP – Scaling M
,
Sel Mi Mi Mi Min TPD Max – UL ABTP P – UL + TP Offset Sel Mi TPD Max–UL = -------------------------------------------------------------------------------------------------Sel Mi Mi
1 – BLER B UL f TP – Scaling
The Min() function selects the lower of the two values. This calculation is performed in order to limit the maximum uplink throughput demand to the maximum throughput that a user can get in uplink using the allocated bandwidth (number of frequency blocks) calculated for it in "C/(I+N) and Bearer Calculation (UL)" on page 532. Resource Allocation for Minimum Throughput Demands: •
Sel
1. Atoll sorts the M i
For their minimum throughput demands, LTE-A users are only scheduled on their primary serving cells.
Sel Mi
TX i ic
Sel Mi
N Users in order of decreasing effective service priority (combination of p QCI and p Service ).
The mobiles are sorted first in the order of decreasing QCI priority (as listed in the table below) and then in the order of decreasing user-defined service priority within a QCI. For example: QoS class identifier
1
2
3
4
5
6
7
8
9
QCI priority
2
4
3
5
1
6
7
8
9
Sel
Mi
1
Sel Mi
p QCI
p Service
1
i
2
:
3 :
Sel Mi
0 2
i
:
:
:
0
:
3
i
:
:
:
0
:
4
i
:
:
:
0
:
5
:
:
: :
i 0
6
i
:
:
:
0
:
7
i
:
:
:
0
:
8
i
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Sel
M
Mi
Sel i
p QCI
:
:
0 9
:
0
:
Sel
= 1 up to M i
i :
:
Sel
Sel i
: :
2. Starting with M i
M
p Service
NULL
i
:
:
N
0 TX ic i
= N Users , Atoll allocates the downlink and uplink resources required to satisfy
each user’s minimum throughput demands in downlink and uplink as follows: Sel Mi
Sel Mi
R Min – DL
Sel Mi
Sel
Mi TPD Min – DL TPD Min – UL = -------------------------- and R Min – UL = -------------------------Sel Mi
Sel Mi
CTP P – DL
CTP P – UL
3. Atoll stops the resource allocation in downlink or uplink, •
When/If in downlink
Sel Mi
TX i ic
R Min – DL = TL DL – Max , i.e., the resources available in downlink have been used up for
Sel Mi
satisfying the minimum throughput demands of the mobiles. •
When/If in uplink
M
Sel Mi
TX i ic
R Min – UL = TL UL – Max , i.e., the resources available in uplink have been used up for
Sel i
satisfying the minimum throughput demands of the mobiles. 4. Mobiles which are active DL+UL must be able to get their minimum throughput demands in both UL and DL in order to be considered connected DL+UL. If an active DL+UL mobile is only able to get its minimum throughput demand in one direction, it is rejected, and the resources that were allocated to it in the one direction in which it was able to get a throughput are allocated to other mobiles. Sel Mi
Max
TP UE – DL - or 5. Mobiles with minimum throughput demands higher than their UE capacities, i.e., R Min – DL -------------------Sel Mi
CTP P – DL Sel
Max
Mi TP UE – UL - , are rejected due to No Service. R Min – UL -------------------Sel Mi
CTP P – UL 6. Mobiles which are active UL and whose minimum throughput demand in UL is higher than the uplink allocated Sel Mi
Sel Mi
bandwidth throughput ( TPD Min – UL ABTP P – UL ) are rejected due to Resource Saturation. 7. If
Sel Mi
TX i ic
R Min – DL TL DL – Max or
Sel Mi
Sel Mi
TX i ic
R Min – UL TL UL – Max , and all the minimum throughput resources demanded by
Sel Mi
the mobiles have been allocated, Atoll goes to the next step for allocating resources to satisfy the maximum throughput demands. Backhaul Saturation: If at this stage, a site’s downlink or uplink effective RLC aggregate throughput exceeds its maximum downlink or uplink S1 interface throughput, respectively, mobiles are rejected one by one due to Backhaul Saturation, starting from the mobile with the lowest priority service, among all the cells of the site in order to reach a downlink or uplink effective RLC aggregate site throughput ≤ the site’s maximum downlink or uplink S1 interface throughput. Resource Allocation for Maximum Throughput Demands: For each cell, the remaining cell resources available are:
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TX ic i
TX ic i
Downlink: R Rem – DL = TL DL – Max –
M TX ic i
TX ic i
Uplink: R Rem – UL = TL UL – Max –
M
M
Sel i
R Min – DL
Sel i M
Sel i
R Min – UL
Sel i
For each mobile, the remaining throughput demands are either the maximum UE capacities or the difference between the maximum and the minimum throughput demands, whichever is smaller: Sel
Sel
Sel
M M M i i i Max Downlink: TPD Rem – DL = Min TPD Max – DL – TPD Min – DL TP UE – DL Sel
Sel
Sel
Mi Mi Mi Max Uplink: TPD Rem – UL = Min TPDMax – UL – TPD Min – UL TP UE – UL
For their maximum throughput demands, LTE-A users are scheduled separately on each of their serving cells, primary and Sel Mi
Sel Mi
secondary. Each user’s remaining throughput demand ( TPD Rem – DL and TPD Rem – UL ) is distributed over each of its serving cells proportionally to the resources available on each serving cell and to the user’s downlink effective RLC channel throughput or uplink effective RLC allocated bandwidth throughput on each of its serving cell:
Downlink:
Sel i TPD Rem – DL Server n M
=
TX i ic
Mi
R Rem – DL CTP E – DL Server n Server n -------------------------------------------------------------------------------------------------5
Sel i TPD Rem – DL M
TX i ic
RRem – DL
Mi
Server n
CTP E – DL
Server n
n=1 Sel Mi
Uplink: TPD Rem – UL
TX i ic
Server n
Mi
R Rem – UL ABTP E – UL Server n Server n = TPD Rem – UL -----------------------------------------------------------------------------------------------------5 Sel Mi
TX i ic
RRem – UL
Mi
Server n
ABTP E – UL
Server n
n=1
You can add an option in the Atoll.ini file to have each user’s remaining throughput demand distributed over each of its serving cells proportionally only to the resources available on each serving cell: Sel Mi
Downlink: TPD Rem – DL
TX i ic
Sel Mi
Server n
R Rem – DL Server n = TPD Rem – DL ----------------------------------------------------5 TX i ic
RRem – DL
Server n
n=1 Sel Mi
Uplink: TPD Rem – UL
TX i ic
Sel Mi
Server n
R Rem – UL Server n = TPD Rem – UL ----------------------------------------------------5 TX ic i
RRem – UL
Server n
n=1
For more information, see the Administrator Manual. Only secondary cells whose PDSCH C/(I+N) is higher than or equal to the secondary cell activation threshold defined in the DL
terminal reception equipment properties ( T SCell ) are activated for aggregation in downlink. Similarly, only secondary cells whose PDSCH C/(I+N) and PUSCH C/(I+N) are both higher than or equal to the secondary cell activation threshold defined in DL
UL
the terminal and cell reception equipment properties ( T SCell and T SCell ), respectively, are activated for aggregation in uplink. Within each serving cell, resource allocation for the maximum throughput demands is carried out according to the scheduler used by that particular cell. For the remaining throughput demands of the mobiles, the following resource allocation methods are available: •
Proportional Fair: The goal of this scheduling method is to distribute resources among users fairly in such a way that, on the average, each user gets the highest possible throughput that it can get under the radio conditions at its location.
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Let the total number of users be N M i
. TX ic i
TX ic i
a. Each user’s channel throughput is increased by the multi-user diversity gain G MUG – DL or G MUG – UL read from the M
Sel i
scheduler properties for the downlink or uplink bearer ( B DL Sel
Mi
M
Sel i
Sel
or B UL ), Mobility M i assigned to mobile
, and the number of connected users, DL or UL, in the cell TXi(ic) in the iteration k-1.
Sel Mi
Sel Mi
CTP P – DL = CTP P – DL
Sel Mi
TX i ic
Without MUG Sel Mi
TX i ic
G MUG – DL = 1 if CINR PDSCH
Sel Mi
G MUG – DL and CTP P – UL = CTP P – UL
G MUG – UL
Sel Mi
TX i ic
Max CINR MUG
TX i ic
Without MUG
Max
and G MUG – UL = 1 if CINR PUSCH PUCCH CINR MUG .
If the multi-user diversity gain for the exact value of the number of connected users is not available in the graph, it is interpolated from the gain values available for the numbers of users just less than and just greater than the actual number of users. b. Atoll divides the remaining resources in the cell into equal parts for each user: TX i ic
TX i ic
R Rem – DL R Rem – UL --------------------- and -------------------N N c. Atoll converts the remaining throughput demands of all the users to their respective remaining resource demands: Sel Mi
RD Rem – DL
Sel Mi
Sel Mi
Sel
Mi TPD Rem – DL TPD Rem – UL = --------------------------- and RD Rem – UL = --------------------------Sel Mi
Sel Mi
CTP P – DL
CTP P – UL
Remaining resource demands of a user are given by the ratio between its remaining throughput demands and the peak channel throughputs at the user’s location. d. The resources allocated to each user by the Proportional Fair scheduling method for satisfying its maximum throughput demands are: Sel
TX i ic
Sel
Sel
Sel
TX i ic
M M Mi Mi R Rem – DL R Rem – UL i i - and R Max R Max – DL = Min RD Rem – DL -------------------– UL = Min RD Rem – UL --------------------- N N
Each user gets either the resources it needs to achieve its maximum throughput demands or an equal share from the remaining resources of the cell, whichever is smaller. e. Atoll stops the resource allocation in downlink or uplink, •
When/If in downlink
Sel Mi
TX i ic
R Max – DL = R Rem – DL , i.e., the resources available in downlink have been used up
Sel Mi
for satisfying the maximum throughput demands of the mobiles. •
When/If in uplink
Sel Mi
TX i ic
R Max – UL = R Rem – UL , i.e., the resources available in uplink have been used up for
Sel Mi
satisfying the maximum throughput demands of the mobiles. f. If the resources allocated to a user satisfy its maximum throughput demands, this user is removed from the list of remaining users. g. Atoll recalculates the remaining resources as follows: TX ic i
TX ic i
R Rem – DL = TL DL – Max –
M
Sel i
R Min – DL –
Sel Mi TX i ic
TX i ic
R Rem – UL = TL UL – Max –
M
558
Sel i
M
Sel i
R Max – DL and
Sel Mi Sel Mi
R Min – UL –
M
Sel i
Sel Mi
R Max – UL
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h. Atoll repeats the all the above steps for the users whose maximum throughput demands have not been satisfied TX ic i
TX ic i
until either R Rem – DL = 0 and R Rem – UL = 0 , or all the maximum throughput demands are satisfied. •
Round Robin: The goal of this scheduling method is to allocate equal resources to users fairly. Sel
Let the total number of users be N M i
.
a. Atoll divides the remaining resources in the cell into equal parts for each user: TX i ic
TX i ic
R Rem – DL R Rem – UL --------------------- and -------------------N N b. Atoll converts the remaining throughput demands of all the users to their respective remaining resource demands: Sel Mi
M
RD Rem – DL
Sel i
M
Sel
Sel i
Mi TPD Rem – DL TPD Rem – UL = --------------------------- and RD Rem – UL = --------------------------Sel Mi
Sel Mi
CTP P – DL
CTP P – UL
Remaining resource demands of a user are given by the ratio between its remaining throughput demands and the peak channel throughputs at the user’s location. c. The resources allocated to each user by the Round Robin scheduling method for satisfying its maximum throughput demands are: Sel Mi
R Max – DL
TX i ic
Sel
Sel
Sel
TX i ic
Mi Mi Mi R Rem – DL R Rem – UL - and R Max = Min RD Rem – DL -------------------– UL = Min RD Rem – UL --------------------- N N
Each user gets either the resources it needs to achieve its maximum throughput demands or an equal share from the remaining resources of the cell, whichever is smaller. d. Atoll stops the resource allocation in downlink or uplink, •
When/If in downlink
Sel Mi
M
TX i ic
R Max – DL = R Rem – DL , i.e., the resources available in downlink have been used up
Sel i
for satisfying the maximum throughput demands of the mobiles. •
When/If in uplink
Sel Mi
TX i ic
R Max – UL = R Rem – UL , i.e., the resources available in uplink have been used up for
Sel Mi
satisfying the maximum throughput demands of the mobiles. e. If the resources allocated to a user satisfy its maximum throughput demands, this user is removed from the list of remaining users. f. Atoll recalculates the remaining resources as follows: TX i ic
TX i ic
R Rem – DL = TL DL – Max –
Sel Mi
R Min – DL –
Sel Mi TX i ic
TX i ic
R Rem – UL = TL UL – Max –
Sel Mi
R Max – DL and
Sel Mi Sel Mi
R Min – UL –
Sel Mi
Sel Mi
R Max – UL
Sel Mi
g. Atoll repeats the all the above steps for the users whose maximum throughput demands have not been satisfied TX i ic
TX i ic
until either R Rem – DL = 0 and R Rem – UL = 0 , or all the maximum throughput demands are satisfied. •
Proportional Demand: The goal of this scheduling method is to allocate resources to users weighted according to their remaining throughput demands. Therefore, the user throughputs for users with high throughput demands will be higher than those with low
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throughput demands. In other words, this scheduler distributes channel throughput between users proportionally to their demands. a. Atoll converts the remaining throughput demands of all the users to their respective remaining resource demands: Sel i RD Rem – DL M
M
Sel i
M
Sel
Sel i
M TPD Rem – DL TPD Rem – UL i = --------------------------- and RD Rem – UL = --------------------------Sel Mi
Sel Mi
CTP P – DL
CTP P – UL
Remaining resource demands of a user are given by the ratio between its remaining throughput demands and the peak channel throughputs at the user’s location. b. Atoll calculates the amount of effective remaining resources of the cell to distribute among the users as follows: Sel Sel TX i ic Mi TX i ic Mi TXi ic TX i ic R Eff – Rem – DL = Min R Rem – DL RD Rem – DL and R Eff – Rem – UL = Min R Rem – UL RD Rem – UL Sel Sel Mi Mi
c. The resources allocated to each user by the Proportional Demand scheduling method for satisfying its maximum throughput demands are: Sel Mi
R Max – DL
•
Sel Mi
TX i ic
Sel Mi
Sel
Mi TX i ic RD Rem – DL RD Rem – UL - and R Max = R Eff – Rem – DL ---------------------------------– UL = R Eff – Rem – UL ---------------------------------Sel Sel Mi
Mi
RDRem – DL
RDRem – UL
Sel Mi
Sel Mi
Max C/I: The goal of this scheduling method is to achieve the maximum aggregate throughput for the cells. This is done by allocating as much resources as needed to mobiles with high C/(I+N) conditions. As mobiles with high C/(I+N) can get higher bearers, and therefore require less amount of resources, more mobiles can therefore be allocated resources in the same frame, and the end-throughput for each cell will be the highest compared to other types of schedulers. Sel
a. Atoll sorts the M i
TX i ic
N Users in order of decreasing PDSCH, or PUSCH and PUCCH C/(I+N), depending on whether
the allocation is being performed for the downlink or for the uplink. b. Starting with the mobile with the highest rank, Atoll allocates the downlink and uplink resources required to satisfy each user’s remaining throughput demands in downlink and uplink as follows: Sel i R Max – DL M
M
Sel i
M
Sel
Sel i
M TPD Rem – DL TPD Rem – UL i = --------------------------- and R Max – UL = --------------------------Sel Mi
Sel Mi
CTP P – DL
CTP P – UL
c. Atoll stops the resource allocation in downlink or uplink, •
When/If in downlink
M
Sel i
TX ic i
R Max – DL = R Rem – DL , i.e., the resources available in downlink have been used up
Sel Mi
for satisfying the maximum throughput demands of the mobiles. •
When/If in uplink
Sel Mi
TX i ic
R Max – UL = R Rem – UL , i.e., the resources available in uplink have been used up for
Sel Mi
satisfying the maximum throughput demands of the mobiles. Spatial Multiplexing with Multi-User MIMO: MU-MIMO lets the system/scheduler work with parallel LTE frames. Therefore, many users can be co-scheduled on the same resources. MU-MIMO can be used if the cell supports MU-MIMO, if the calculated value for the MU-MIMO criterion is higher TX i ic
TX i ic
than the MU-MIMO threshold T MU – MIMO – DL or T MU – MIMO – UL , and the number of antenna ports is equal to 2 or more. In both downlink and uplink, each mobile resource consumptions of a mobile
560
MU – MIMO Mi
MU – MIMO Mi
has a corresponding traffic load TL
are given by:
MU – MIMO Mi
. However, the actual
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AT330_TRR_E1
MU – MIMO i RC DL M
M
MU – MIMO i
MU – MIMO
M TL DL i = ----------------------------------- and RC UL TX ic i G MU – MIMO – DL
Saturation occurs when
M
MU – MIMO – UL i
RC UL
M
MU – MIMO i
TL UL = -----------------------------------TX ic i G MU – MIMO – UL
TX ic i
= TL UL – Max or
M
MU – MIMO – DL i
RC DL
TX ic i
= TL DL – Max .
Backhaul Capacity Limitation: Backhaul overflow ratios are calculated for each site as follows: Sel Sel Mi Mi R Max – DL CTP E – DL Sel M i Site = Max 1 ------------------------------------------------------------------------------------------------------ and Sel Sel Mi Mi Site TP – R CTP S1 – DL Min – DL E – DL Sel M i Site
Site BHOFDL
Sel Sel Mi Mi R Max – UL CTP E – UL Sel M Site i = Max 1 ------------------------------------------------------------------------------------------------------ Sel Sel Mi Mi Site R Min – UL CTP E – UL TP S1 – UL – Sel M i Site
Site
BHOFUL
Total Amount of Resources Assigned to Each Selected Mobile: Sel
Atoll calculates the amounts of downlink and uplink resources allocated to each individual mobile M i
(which can also be
referred to as the traffic loads of the mobiles) as follows: Sel
Sel Mi
Downlink: TL DL
Sel Mi
= R DL
M
Sel i
M
Sel i
R Mi Mi Max – DL CTP P – DL R Min – DL CTP P – DL + -----------------------------------------------Site BHOF DL = -----------------------------------------------------------------------------------------------------------------Sel
Sel Mi
CTP P – DL Sel
Sel Mi
Uplink: TL UL
Sel Mi
= R UL
Sel Mi
Sel Mi
R Mi Mi Max – UL CTP P – UL R Min – UL CTP P – UL + -----------------------------------------------Site BHOF UL = -----------------------------------------------------------------------------------------------------------------Sel
M
Sel i
CTP P – UL Output Sel Mi
•
TL DL
•
TL UL
Sel Mi
Sel Mi
= R DL
Sel
: Downlink traffic load or the amount of downlink resources allocated to the mobile M i .
Sel Mi
Sel
= R UL : Uplink traffic load or the amount of uplink resources allocated to the mobile M i .
6.4.7.2 User Throughput Calculation User throughputs are calculated for the percentage of resources allocated to each mobile selected by the scheduling for RRM Sel
during the Monte Carlo simulations, M i . Carrier Aggregation: Aggregated throughputs are calculated by summing the throughputs from each serving cell taking part in carrier aggregation for any LTE-A mobile, limited by the maximum throughput supported by the UE category.
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Input
•
M
Sel i
R DL
Sel
: Amount of downlink resources allocated to the mobile M i
as calculated in "Scheduling and Radio Resource
Allocation" on page 552. •
Sel i R UL M
Sel
: Amount of uplink resources allocated to the mobile M i
as calculated in "Scheduling and Radio Resource
Allocation" on page 552. •
Sel Mi
Sel
CTP P – DL : Downlink peak RLC channel throughput at the mobile M i
as calculated in "Throughput Calculation" on
page 538. •
Sel Mi
Sel
CTP P – UL : Uplink peak RLC channel throughput at the mobile M i
as calculated in "Throughput Calculation" on
page 538. Sel
•
TX i ic Mi BLER BDL : Downlink block error rate read from the BLER vs. CINR PDSCH graph available in the reception Sel
equipment assigned to the terminal used by the mobile M i
.
Sel
•
Mi Mi BLER BUL : Uplink block error rate read from the BLER vs. CINR PUSCH PUCCH graph available in the reception equipment assigned to the cell TXi(ic). Sel Mi
Sel
•
f TP – Scaling : Throughput scaling factor defined in the properties of the service used by the mobile M i
•
TP Offset : Throughput offset defined in the properties of the service used by the mobile M i
Sel Mi
Sel
Calculations Downlink: Sel Mi
Sel Mi
Sel Mi
CTP P – DL
•
Peak RLC User Throughput: UTP P – DL = R DL
•
Mi Mi Mi Effective RLC User Throughput: UTP E – DL = UTP P – DL 1 – BLER B DL
Sel
•
Sel Mi
Application User Throughput: UTP A – DL
Sel
Sel
Sel Mi
Sel Mi
Sel
Mi f TP – Scaling - – TP Offset = UTP E – DL -----------------------100
Uplink: Sel Mi
Sel Mi
Sel Mi
CTP P – UL
•
Peak RLC User Throughput: UTP P – UL = R UL
•
Mi Mi Mi Effective RLC User Throughput: UTP E – UL = UTP P – UL 1 – BLER B UL
Sel
•
Sel Mi
Application User Throughput: UTP A – UL
Sel
Sel Mi
Sel
Sel Mi
Sel
Mi f TP – Scaling - – TP Offset = UTP E – UL -----------------------100
Output Sel
UTP P – DL : Downlink peak RLC user throughput at the pixel, subscriber, or mobile M i
•
Sel Mi UTP E – DL
•
UTP A – DL : Downlink application user throughput at the pixel, subscriber, or mobile M i .
•
562
Sel Mi
•
Sel
: Downlink effective RLC user throughput at the pixel, subscriber, or mobile M i .
Sel Mi Sel Mi
.
Sel
Sel
UTP P – UL : Uplink peak RLC user throughput at the pixel, subscriber, or mobile M i
.
.
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M
Sel i
M
Sel i
Sel
•
UTP E – UL : Uplink effective RLC user throughput at the pixel, subscriber, or mobile M i
•
UTP A – UL : Uplink application user throughput at the pixel, subscriber, or mobile M i .
.
Sel
6.5 Automatic Planning Algorithms The following sections describe the algorithms for: • • • • •
"Automatic Neighbour Planning" on page 563. "Automatic Inter-technology Neighbour Planning" on page 567. "Automatic Frequency Planning Using the AFP" on page 570. "Automatic Physical Cell ID Planning Using the AFP" on page 572. "Automatic PRACH RSI Planning Using the AFP" on page 576.
6.5.1 Automatic Neighbour Planning The intra-technology neighbour planning algorithm takes into account the cells of all the TBC transmitters. It means that the cells of all the TBC transmitters of your ATL document are potential neighbours. The cells to be allocated will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone, They belong to the folder on which allocation has been executed. This can be the Transmitters folder or a group of transmitters (subfolder).
Only TBA cells are assigned neighbours. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
We assume a reference cell TXi(ic) and a candidate neighbour cell TXj(jc). When automatic allocation starts, Atoll checks the following conditions: 1. The distance between both cells must be less than the user-definable maximum inter-site distance. If the distance between the reference cell and the candidate neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance between the reference cell and its candidate neighbour from the real distance between them and the azimuths of their antennas: Dist CellA CellB = D 1 + x cos – x cos Where x = 0.3% so that the maximum variation in D does not to exceed 1%. D is stated in m.
Figure 6.3: Inter-Transmitter Distance Calculation The formula above implies that two cells facing each other have a smaller effective distance than the actual distance. Candidate neighbours are ranked in the order of increasing effective distance from the reference cell. 2. The calculation options,
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•
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Force Co-site Cells as Neighbours: If selected, Atoll adds all the cells located on the same site as the reference cell to the candidate neighbour list. The weight of this constraint can be defined. It is used to calculate the rank of each neighbour, and its importance. Force Adjacent Cells as Neighbours: If selected, Atoll adds all the cells geographically adjacent to the reference cell to the candidate neighbour list. The weight of this constraint can be defined. It is used to calculate the rank of each neighbour, and its importance. Determination of Adjacent Cells: Geographically adjacent cells are determined on the basis of their best server coverage areas. A candidate neighbour cell TXi(ic) is considered adjacent to the reference cell TXi(ic) if there exists at least one pixel of TXj(jc)’s best server coverage area where TXi(ic) is the second best server. The ranking of adjacent neighbour cells increases with the number of such pixels. Adjacent cells are sorted in the order of decreasing rank.
Figure 6.4: Determination of Adjacent Cells •
•
Force Adjacent Layers as Neighbours: If selected, Atoll adds all the cells adjacent across network layers to the reference cell to the candidate neighbour list. The weight of this constraint is always the average of the Min and Max values defined for the adjacency factor. This weight is used to calculate the rank of each neighbour and its importance. Cells are considered adjacent across layers if they belong to different layers and have a coverage overlap of at least one pixel. Force Symmetry: If selected, Atoll adds the reference cell to the candidate neighbour list of the its candidate neighbour. A symmetric neighbour relation is allowed only if the neighbour list of the reference cell is not already full. If TXj(jc) is a neighbour of TXi(ic) but TXi(ic) is not a neighbour of TXj(jc), there can be two possibilities: i.
The neighbour list of TXj(jc) is not full, Atoll will add TXi(ic) to the end of the list.
ii. The neighbour list of TXj(jc) is full, Atoll will not be able to add TXi(ic) to the list, so it will also remove TXj(jc) from the neighbour list of TXi(ic). If the neighbours list of a cell is full, the reference cell will not be added as a neighbour of that cell and that cell will be removed from the reference cell’s neighbours list. You can force Atoll to keep that cell in the reference cell’s neighbours list by adding the following option in the Atoll.ini file: [Neighbours] DoNotDeleteSymmetrics = 1 •
Force Exceptional Pairs: This option enables you to force/forbid some neighbour relations. Exceptional pairs are pairs of cells which will always or never be neighbours of each other. If you select "Force exceptional pairs" and "Force symmetry", Atoll considers the constraints between exceptional pairs in both directions so as to respect symmetry condition. On the other hand, if neighbourhood relationship is forced in one direction and forbidden in the other, symmetry cannot be respected. In this case, Atoll displays a warning in the Event viewer.
•
Delete Existing Neighbours: If selected, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, the existing neighbours are kept in the list.
3. If the Use Coverage Conditions check box is selected, the coverage areas of TXi(ic) and TXj(jc) must have an overlap. Otherwise, only the distance criterion is taken into account. The overlapping zone ( S TX ic S TX jc ) is defined as follows i
•
564
j
Here S TX ic is the surface area covered by the cell TXi(ic) that comprises all the pixels where: i
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•
The distance to the cell TXi(ic) is less than or equal to the round-trip time distance corresponding to the cell’s PRACH preamble format.
•
The received RSRP is greater than or equal to the cell’s Min RSRP: E DLRS T RSRP .
•
The received RSRP is within E DLRS + O Individual + M HO
TX ic i
TX ic i
TX i ic
M HO
TX i ic
M HO •
TX ic i
TX ic i
TX ic i
TX ic i
TX ic i
TX ic i
and E DLRS + O Individual + M HO
+ M End .
is the handover margin defined for the cell TXi(ic). When a global handover start value is used, = M Start . M Start and M End are global handover start and handover end values.
S TX jc is the surface area covered by the cell TXj(jc) that comprises all the pixels where: j
•
The distance to the cell TXj(jc) is less than or equal to the round-trip time distance corresponding to the cell’s PRACH preamble format.
•
The received RSRP is greater than or equal to the cell’s Min RSRP: E DLRS T RSRP .
•
The received RSRP with offset ( E DLRS + O Individual ) is the highest.
TX jc j
TX j jc
•
•
TX jc j
TX j jc
TX i ic
If a global value of the minimum RSRP threshold ( T RSRP ) is set in the coverage conditions dialogue, for each cell, Atoll uses the higher of the two values, i.e., global value and the value defined for that cell. For calculating the overlapping coverage areas, Atoll uses the service with the lowest body loss, the terminal that has the highest difference between gain and losses, and the shadowing margin calculated using the defined cell edge coverage probability, if the option is selected. The service and terminal are selected such that the selection gives the largest possible coverage areas for the cells.
S TX ic S TX jc i j When the above conditions are met, Atoll calculates the percentage of the coverage area overlap ( --------------------------------------- 100 ), S TX ic i
and compares this value with the % Min Covered Area. TXj(jc) is considered a neighbour of TXi(ic) if S TX ic S TX jc i j -------------------------------------- 100 % Min Coverage Area . S TX ic i
Figure 6.5: Overlapping Zones Next, Atoll calculates the importance of the automatically allocated neighbours. Atoll sorts the neighbours by decreasing importance in order to keep the ones with high importance. If the maximum number of neighbours to be allocated to each cell is exceeded, Atoll keeps the ones with high importance. The neighbour importance depends on the distance from the reference transmitter and on the neighbourhood cause (cf. table below); this value varies between 0 and 100%.
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Neighbourhood cause
When
Importance value
Existing neighbour
Only if the Delete Existing Neighbours option is not selected and in case of a new allocation
Existing importance
Exceptional pair
Only if the Force Exceptional Pairs option is selected
100 %
Co-site cell
Only if the Force Co-site Cells as Neighbours option is selected
Importance Function (IF)
Adjacent layer
Only if the Force Adjacent Layers as Neighbours option is selected
Importance Function (IF)
Adjacent cell
Only if the Force Adjacent Cells as Neighbours option is selected
Importance Function (IF)
Neighbourhood relationship that fulfils coverage conditions
Only if the % Min Covered Area is exceeded
Importance Function (IF)
Symmetric neighbourhood relationship
Only if the Force Neighbour Symmetry option is selected
Importance Function (IF)
The importance is evaluated using an Importance Function (IF), which takes into account the following factors: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance ( D in m) weighted by the azimuths of antennas. d max is the maximum distance between the reference transmitter and a possible neighbour.
• • •
The co-site factor (C): a Boolean, The adjacency factor (A): the percentage of adjacency, The overlapping factor (O): the percentage of overlapping.
The minimum and maximum importance assigned to each of the above factors can be defined. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
30%
Adjacency factor (A)
Min(A)
30%
Max(A)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The Importance Function is evaluated as follows: Neighbourhood cause
Importance Function
Resulting IF using the default values from the table above
Coverage
Min(O)+Delta(O){Max(Di)(Di)+(100%Max(Di))(O)}+Min(Di)+Delta(Di)(Di)
10%+20%{10%(Di)+90%(O)}+1%+9%(Di)
Adjacent layer
(Min(A)+Max(A))/2
45%
Adjacent cells
Min(A)+Delta(A){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
30%+30%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Co-site cells
Min(C)+Delta(C){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
60%+40%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Where: Delta(X)=Max(X)-Min(X)
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• •
•
•
Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours, adjacent layers, adjacent cells, and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes. The default value of Min(O) = 1% ensures that neighbours selected for symmetry will have an importance greater than 0%. With a value of Min(O) = 0%, neighbours selected for symmetry will have an importance field greater than 0% only if there is some coverage overlapping.
In the results, Atoll lists only the cells for which it finds new neighbours. Cells whose channels have the same centre frequency are listed as intra-carrier neighbours. Otherwise, neighbour cells are listed as inter-carrier neighbours. •
By default, the automatic neighbour allocation compares the defined Max intersite distance with the effective inter-cell distance. As a consequence, there can be cases where the real distance between assigned neighbours is higher than the Max inter-site distance, because the effective distance is smaller. You can force Atoll to compare the Max inter-site distance with the real inter-site distance by adding the following lines in Atoll.ini: [Neighbours] RealInterSiteDistanceCondition=1
•
By default, the neighbour importance calculated with respect to distance is based on the global Max inter-site distance setting for all neighbour candidates. As a consequence, there can be cases where the calculated importance is different when the global Max inter-site distance is modified. To avoid that, you can force Atoll to prioritise the individual distances between reference cells and their respective neighbour candidates by adding the following lines in Atoll.ini: [Neighbours] CandidatesMaxDistanceInImportanceCalculation=1
6.5.2 Automatic Inter-technology Neighbour Planning The inter-technology neighbour planning algorithm takes into account all the TBC transmitters (if the other technology is GSM) or the cells of all the TBC transmitters (for any other technology than GSM). This means that all the TBC transmitters (GSM) or the cells of all the TBC transmitters (all other technologies) of the linked document are potential neighbours. The cells to be allocated in the main document will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone, They belong to the folder on which allocation has been executed. This can be the Transmitters folder or a group of transmitters (subfolder).
Only TBA cells are assigned neighbours. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
We assume a reference cell A and a candidate neighbour B. When automatic allocation starts, Atoll checks following conditions: 1. The distance between reference cell and the candidate neighbour must be less than the user-definable maximum inter-site distance. If the distance is greater than this value, the candidate neighbour is discarded. Atoll calculates the effective distance between the reference cell and its candidate neighbour from the real distance between them and the azimuths of their antennas: Dist CellA CellB = D 1 + x cos – x cos
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Where x = 0.3% so that the maximum variation in D does not to exceed 1%. D is stated in m.
Figure 6.6: Inter-Transmitter Distance Calculation The formula above implies that two cells facing each other have a smaller effective distance than the actual distance. Candidate neighbours are ranked in the order of increasing effective distance from the reference cell. 2. The calculation options: •
•
• •
CDMA carriers: This option is available when an LTE network is being co-planned with a UMTS, CDMA, or TDSCDMA network. This option enables you to select the CDMA carrier(s) that you want Atoll to consider as potential neighbours of LTE cells. You may choose one or more carriers. Atoll will allocate only the cells using the selected carriers as neighbours. Force co-site cells as neighbours: If selected, Atoll adds all the transmitters/cells located on the same site as the reference cell in its candidate neighbour list. The weight of this constraint can be defined. It is used to calculate the rank of each neighbour and its importance. Force exceptional pairs: This option enables you to force/forbid some neighbour relations. Exceptional pairs are pairs of cells which will always or never be neighbours of each other. Delete existing neighbours: If selected, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, the existing neighbours are kept in the list.
3. Neighbour relation criterion: •
Allocation based on distance: The allocation algorithm is based on the effective distance between the reference cell and its candidate neighbour.
•
Algorithm based on coverage overlapping: The coverage areas of the reference cell A and the candidate neighbour B must overlap ( S A S B ). Two cases may exist for SA: •
1st case: SA is the area where the cell A is the best serving cell, with a 0 dB margin. This means that the reference signal energy per resource element received from A is greater than the minimum required (Min RSRP), and is the highest one. .
•
2nd case: The margin is other than 0 dB. SA is the area where: The reference signal energy per resource element received from A exceeds the minimum required (Min RSRP) and is within a margin from the highest signal level.
Two cases may exist for SB: •
1st case: SB is the area where the candidate neighbour is the best server. In this case, the margin must be set to 0dB. The signal level received from B exceeds the minimum required, and is the highest one.
•
2nd case: The margin is other than 0dB. SB is the area where: The signal level received from B exceeds the minimum required and is within a margin from the best signal level.
SA SB - 100 ) and compares this value with the % Atoll calculates the percentage of the coverage area overlap ( ----------------SA SA SB - 100 % Min Covered Area . Min Covered Area. B is considered a neighbour of A if ----------------SA Candidate neighbours are ranked in the order of decreasing coverage area overlap percentages.
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Next, Atoll calculates the importance of the automatically allocated neighbours. Atoll sorts the neighbours by decreasing importance in order to keep the ones with high importance. If the maximum number of neighbours to be allocated to each cell is exceeded, Atoll keeps the ones with high importance. The importance (%) of neighbours depends on the distance and on the reason of allocation: •
For allocation based on distance: Neighbour cause
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter/cell
If the Force co-site cells as neighbours option is selected
100 %
Neighbour relation that fulfils distance conditions
If the maximum distance is not exceeded
d1 – ---------d max
d is the effective distance between the reference cell and the neighbour and d max is the maximum inter-site distance. •
For allocation based on coverage overlapping: Neighbour cause
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter/cell
If the Force co-site cells as neighbours option is selected
IF
Neighbourhood relationship that fulfils coverage conditions
If the % minimum covered area is exceeded
IF
The importance is evaluated using an Importance Function (IF), which takes into account the following factors: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. d max is the maximum distance between the reference transmitter and a possible neighbour.
• •
The co-site factor (C): a Boolean, The overlapping factor (O): the percentage of overlapping.
The IF is user-definable using the Min importance and Max importance fields. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The IF evaluates importance as follows: Co-site Neighbourhood cause
IF
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%-Max(Di))(O)}
10%+50%{10%(Di)+90%(O)}
Yes
Min(C)+Delta(C){Max(Di)(Di)/(Max(Di)+Max(O))+ Max(O)(O)/(Max(Di)+Max(O))}
60%+40%{1/7%(Di)+6/7%(O)}
Where Delta(X)=Max(X)-Min(X)
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•
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Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes.
In the results, Atoll displays only the cells for which it finds new neighbours.
6.5.3 Automatic Frequency Planning Using the AFP The role of an Automatic Frequency Planning (AFP) tool is to assign frequencies (channels) to cells of a network such that the overall network performance is optimised. In other words, the interference within the network is reduced as much as possible. Co-channel interference is the main reason for overall network quality degradation in LTE. In order to improve network performance, the LTE AFP tries to minimise co- and adjacent channel interference as much as possible while respecting any constraints input to it. The main constraints are the resources available for allocation, i.e., the number of frequencies with which the AFP can work, and the relationships to take into account, i.e., interference matrices, neighbours, and distance between transmitters. The AFP is based on a cost function which represents the interference level in the network. The aim of the AFP is to minimise the cost. The best, or optimum, frequency plan is the one which corresponds to the lowest cost. The following describes the AFP’s automatic planning method for carriers in LTE networks, which takes into account interference matrices, neighbour relations, and distance between transmitters. The AFP takes into account the cells of all the TBC transmitters. The cells to be allocated will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, Their channel allocation status is not set to locked, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
6.5.3.1 Constraint and Relationship Weights The AFP is based on a cost function which takes into account channel separation constraints based on the channel overlap ratio as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 493. Channel separation is studied between each TBA cell and its related cells. Atoll calculates the cost between each individual TBA and related cell, and then the overall cost for the TBA cell. Related cells of a TBA cell are: •
Its neighbours, if the check box "Existing neighbours" is selected, Default weight Neighbour = 0.5
•
Cells that are listed in the interference matrix of the TBA cell, Default weight IM = 0.3
•
Cells within the cell’s (or the default) minimum reuse distance, if the check box "Reuse distance" is selected, Default weight Dis tan ce = 0.2 The sum of the weights assigned to the above relations is 1.
You can modify these weights in your LTE document. The absolute values of the constraint weights are calculated from the relative weights (%) defined in the Constraint Weights dialogue as follows:
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% Neighbour Neighbour = ---------------------------------------------------------------------------------% Neighbour + % IM + % Dis tan ce % IM IM = ---------------------------------------------------------------------------------% Neighbour + % IM + % Dis tan ce % Dis tan ce Dis tan ce = ---------------------------------------------------------------------------------% Neighbour + % IM + % Dis tan ce
6.5.3.2 Cost Calculation The cost of the relation between the TBA cell and its related cell is calculated as follows: $
TX i ic – TX j jc
TX i ic – TX j jc
= rO
TX i ic – TX j jc
Where r O
TX i ic – TX j jc
Neighbour Neighbour
TX i ic – TX j jc
+ Dis tan ce Dis tan ce
TX ic – TX j jc
+ i IM IM
is the channel overlap ratio as calculated in "Co- and Adjacent Channel Overlaps Calculation" on
page 493. TX i ic – TX j jc
TX i ic – TX j jc
Neighbour
is the importance of the relationship between the TBA cell and its related neighbour cell. Neighbour
is
calculated during automatic neighbour planning by Atoll as explained in "Automatic Neighbour Planning" on page 563. For manual neighbour planning, this value is equal to 1. TX i ic – TX j jc
IM
is the importance of the relationship between the TBA cell and its related interfering cell calculated as follows:
TX i ic – TX j jc
TX i ic – TX j jc
IM
= r CCO
TX i ic – TX j jc
TX i ic – TX j jc
IM – CC
and IM – CC
TX i ic – TX j jc
IM – CC
TX i ic – TX j jc
+ r ACO
TX i ic – TX j jc
IM – AC
are respectively the co- and adjacent channel interference probabilities calculated as TX ic – TX jc i j
explained in "Interference Matrix Calculation" on page 578. r CCO
TX ic – TX jc i j
and r ACO
are the co- and adjacent channel
overlap ratios as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 493. TX i ic – TX j jc
Dis tan ce
is the importance of the relationship between the TBA and its related cell with respect to the distance between
TX i ic – TX j jc
them. Dis tan ce
is calculated as explained in "Distance Importance Calculation" on page 579.
Atoll calculates the quality reduction factor for the TBA cell and its related cell from the cost calculated above as follows: QRF
TX i ic – TX j jc
= 1–$
TX i ic – TX j jc
The quality reduction factor is a measure of the cost of an individual relation. The total cost of the current frequency plan for any TBA cell is given as follows, considering all the cells with which the TBA cell has relations: TX i ic
$ Total = 1 –
QRF
TX i ic – TX j jc
TX j jc
And, the total cost of the current frequency plan for the entire network is simply the sum of the total TBA cell costs calculated above, i.e., $ Total =
TX i ic
$ Total
TX ic i
6.5.3.3 AFP Algorithm The AFP algorithm is an iterative algorithm which: • • • •
Calculates the cost (as describe d above) of the initial frequency plan, Tries different frequency plans in order to reduce the cost, Memorises the different frequency plans in order to determine the best one, i.e., the frequency plan which provides the lowest total cost, Stops when it is unable to improve the cost of the network, and proposes the last known best frequency plan as the solution.
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6.5.4 Automatic Physical Cell ID Planning Using the AFP In LTE, 504 physical cell IDs are available, numbered from 0 to 503. There are as many pseudo-random sequences defined in the 3GPP specifications. Physical cell IDs are grouped into 168 unique cell ID groups (called SSS IDs in Atoll), with each group containing 3 unique identities (called PSS IDs in Atoll). An SSS ID is thus uniquely defined by a number in the range of 0 to 167, and a PSS ID is defined by a number in the range of 0 to 2. Each cell’s downlink reference signals transmit a pseudo-random sequence corresponding to the physical cell ID of the cell. The SSS and PSS are transmitted over the centre six frequency blocks independent of the channel bandwidths used by cells. Mobiles synchronise there transmission and reception frequency and time by listening first to the PSS. Once they know the PSS ID of the cell, they listen to the SSS of the cell in order to know the SSS ID. The combination of these two IDs gives the physical cell ID and the associated pseudo-random sequence that is transmitted over the downlink reference signals. Once the physical cell ID and the associated pseudo-random sequence is known to the mobile, the cell is recognized by the mobile based on the received downlink reference signals. Downlink channel quality measurements are also made on the downlink reference signals. As can be understood from the above description, if all the cells in the network transmit the same physical cell ID, it will be impossible for a mobile to identify different cells. Cell search and selection will be impossible. Therefore, it is important to intelligently allocate physical cell IDs to cells so as to allow easy recognition of cells by mobiles. The following describes the AFP’s automatic planning method for physical cell IDs in an LTE network, which takes into account interference matrices, neighbour relations (first-order neighbours, first-order neighbours of a common LTE cell, first-order neighbours of a common GSM or UMTS cell in 3GPP multi-RAT documents and CDMA cell in 3GPP2 multi-RAT documents, and optionally second-order neighbours), distance between transmitters, and the frequency plan of the network. The AFP takes into account the cells of all the TBC transmitters. The cells to be allocated will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, Their PSS ID and SSS ID statuses are both not set to locked, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
6.5.4.1 Constraint and Relationship Weights The AFP is based on a cost-based function which takes into account the following constraints, in the order of priority: 1. Physical cell ID, Assigned weight ID = 0.75 2. PSS ID, Assigned weight PSS = 0.02 3. SSS ID, Assigned weight SSS = 0.23 4. PCI Mod 6, for single-antenna port DL CRS), Assigned weight CRS = 0 5. PCI Mod 30, for UL DMRS sequence groups, Assigned weight ULDMRS = 0 6. PCI Mod (number of frequency blocks / 2), for PCFICH resource element groups, Assigned weight PCFICH = 0 The sum of the weights assigned to the above constraints is 1.
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You can modify these weights in your LTE document. The absolute values of the constraint weights are calculated from the relative weights (%) defined in the Constraint Weights dialogue as follows: % ID ID = --------------------------------------------------------------------------------------------------------------------------------------------% ID + % PSS + % SSS + % CRS + % ULDMRS + % PCFICH % PSS PSS = --------------------------------------------------------------------------------------------------------------------------------------------% ID + % PSS + % SSS + % CRS + % ULDMRS + % PCFICH % SSS SSS = --------------------------------------------------------------------------------------------------------------------------------------------% ID + % PSS + % SSS + % CRS + % ULDMRS + % PCFICH % CRS CRS = --------------------------------------------------------------------------------------------------------------------------------------------% ID + % PSS + % SSS + % CRS + % ULDMRS + % PCFICH % ULDMRS ULDMRS = --------------------------------------------------------------------------------------------------------------------------------------------% ID + % PSS + % SSS + % CRS + % ULDMRS + % PCFICH % PCFICH PCFICH = --------------------------------------------------------------------------------------------------------------------------------------------% ID + % PSS + % SSS + % CRS + % ULDMRS + % PCFICH The above constraints are studied between each TBA cell and its related cells. Atoll calculates the cost between each individual TBA and related cell, and then the overall cost for the TBA cell. Related cells of a TBA cell are: •
Its neighbours, if the check box "Existing neighbours" is selected, Assigned weight Neighbour = 0.35 TBA cells which are first-order neighbours of a common cell are also related to each other through that cell. This relation is also taken into account, Assigned weight Inter – Neighbour = 0.15 You can choose to not take into account the physical cell ID collision between neighbours of a common cell by adding an option in the Atoll.ini file (see the Administrator Manual). If the collision between neighbours of a common cell is not taken into account, the weight assigned to the direct first-order neighbour relation alone is Neighbour = 0.5 and that of the collision between neighbours of a common cell is of course Inter – Neighbour = 0 . By adding an option in the Atoll.ini file (see the Administrator Manual), second-order neighbours can also be taken into account. In this case, the assigned weights are: Neighbour = 0.25 , 2nd – Neighbour = 0.10 , and Inter – Neighbour = 0.15 . Inter – Neighbour applies to the relation between neighbours of a common cell, which can be an LTE cell, a UMTS cell or a GSM transmitter in 3GPP multi-RAT documents or an LTE or CDMA cell in 3GPP2 multi-RAT documents. Figure 6.7 on page 573 depicts the different neighbour relations that may exist in LTE.
Figure 6.7: Neighbour Relations for Physical Cell ID Allocation •
Cells that are listed in the interference matrix of the TBA cell,
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Assigned weight IM = 0.3 •
Cells within the cell’s (or the default) reuse distance, if the check box "Reuse distance" is selected, Assigned weight Dis tan ce = 0.2 The sum of the weights assigned to the above relations is 1.
You can modify these weights in your LTE document. The absolute values of the constraint weights are calculated from the relative weights (%) defined in the Constraint Weights dialogue as follows: % Neighbour Neighbour = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------% Neighbour + % Inter – Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce % Inter – Neighbour Inter – Neighbour = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------% Neighbour + % Inter – Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce % 2nd – Neighbour 2nd – Neighbour = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------% Neighbour + % Inter – Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce % IM IM = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------% Neighbour + % Inter – Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce % Dis tan ce Dis tan ce = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------% Neighbour + % Inter – Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce
6.5.4.2 Cost Calculation Atoll calculates the constraint violation levels between the TBA cell TXi(ic) and its related cell TXj(jc) as follows: TX ic – TX jc i j
VL 1
TX ic – TX jc i j
VL 2
ID
SSS
CRS
ULDMRS
PCFICH
= ID p Coll + SSS p Penalty + CRS p Coll + ULDMRS p Coll
+ PCFICH p Coll
PSS
= PSS p Coll
Where ID , PSS , and SSS are the weights assigned to the physical cell ID, PSS ID, and SSS ID constraints.
ID p Coll
is the physical cell ID collision probability given by
ID p Coll
1 = 0
1 PSS PSS p Coll is the PSS ID collision probability given by p Coll = 0
SSS
SSS
p Penalty is the SSS ID penalty given by p Penalty
1 = 1 0
TX ic i
if ID
TX i ic
if ID TX i ic
if ID PSS
TX j jc
.
ID
TX j jc
= ID PSS
if ID PSS
TX i ic
TX jc j
= ID
TX j jc
.
ID PSS
TX i ic
TX i ic
if R Co-site 3 AND ID SSS TX ic i
if R Co-site 3 AND
TX ic i
ID
TX j jc
ID SSS
TX jc j
– ID
TX ic i
R Co-site
if the SSS ID
Otherwise
SSS
planning strategy is set to "Same per site", and by p Penalty = 0 if the SSS ID planning strategy is set to "Free". The SSS penalty models the SSS ID allocation constraint. CRS
p Coll
is
1 CRS p Coll = 0
574
the
single TX i ic
if ID
TX i ic
if ID
antenna
downlink TX j jc
Mod6 = ID
TX j jc
Mod6 ID
Mod6
Mod6
cell-specific
.
reference
signal
collision
probability
given
by
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ULDRMS
p Coll
PCFICH
1 = 0
ULDMRS
is the UL DMRS collision probability given by p Coll
TX ic i
if ID
TX jc j
Mod30 = ID
TX ic i ID Mod30
if
Mod30
TX jc j ID Mod30
.
p Coll
is the collision probability of the physical control format indicator channel resource element groups given by
PCFICH p Coll
1 = 0
TX i ic
TX j jc
TX i ic
TX j jc
TX i ic
TX j jc N FB N FB Mod ---------------- = ID Mod ----------------- 2 2
TX i ic
TX j jc N FB N FB - Mod ---------------Mod --------------- ID 2 2
if ID
if ID
.
Next, Atoll calculates the importance of the neighbour relations between the TBA cell and its related cell. TX i ic – TX j jc
Neighbours
TX i ic – TX j jc
= Neighbour Neighbour
TX i ic – TX j jc
+ Inter – Neighbour Inter – Neighbour + 2nd – Neighbour 2nd – Neighbour TX i ic – TX j jc
Where Neighbour
is the importance of the relationship between the TBA cell and its related neighbour cell. Neighbour
is calculated during automatic neighbour planning by Atoll as explained in "Automatic Neighbour Planning" on page 563. For manual neighbour planning, this value is equal to 1. Inter – Neighbour is calculated from the neighbour relationship importance values calculated during automatic neighbour planning. If two cells are neighbours of a common cell and have the same physical cell ID assigned, the importance of the physical cell ID collision is the average of their neighbour importance values with the common neighbour cell. If more than one pair of neighbours of the TBA cell has the same physical cell ID assigned, then the importance is the highest value among all the averages: TX i ic – TX j1 j1c
Inter – Neighbour
TX i ic – TX j2 j2c
Neighbour + Neighbour = Max --------------------------------------------------------------------------------- 2 All Neighbour Pairs with ID Collisions
Where TX j1 j1c and TX j2 j2c are two neighbours of the TBA cell TX i ic that have the same physical cell ID assigned. The above applies to intra-technology as well as inter-technology neighbours in 3GPP multi-RAT and 3GPP2 multi-RAT documents. 2nd – Neighbour is calculated from the neighbour relationship importance values calculated during automatic neighbour planning. If the TBA cell has the same physical cell ID assigned as one of its second-order neighbours, the importance of the physical cell ID collision is the multiple of the importance values of the first order neighbour relations between the TBA cell and its second order neighbour. If the TBA cell is related to its second order neighbour through more than one first order neighbour, the importance is the highest value among all the multiples: 2nd – Neighbour =
TX ic – TX jc
j i Neighbour All Neighbour Pairs
Max
TX j jc – TX k kc
Neighbour
with ID Collisions
Where TX k kc is the second-order neighbour of TX i ic through TX j jc . Next, Atoll calculates the importance of the interference relations between the TBA cell and its related cell. TX i ic – TX j jc
Interference
TX i ic – TX j jc
IM
TX i ic – TX j jc
IM
TX i ic – TX j jc
= IM IM
TX i ic – TX j jc
IM – CC
TX i ic – TX j jc
f Overlap
is the importance of the relationship between the TBA cell and its related interfering cell calculated as follows: TX i ic – TX j jc
= r CCO
TX i ic – TX j jc
and IM
TX i ic – TX j jc
+ Dis tan ce Dis tan ce
TX i ic – TX j jc
IM – CC
TX i ic – TX j jc
= IM – CC
TX i ic – TX j jc
and IM – CC
TX i ic – TX j jc
+ r ACO
TX i ic – TX j jc
IM – AC
if the frequency plan is taken into account
otherwise.
are respectively the co- and adjacent channel interference probabilities calculated as TX i ic – TX j jc
explained in "Interference Matrix Calculation" on page 578. r O
TX i ic – TX j jc
, r CCO
TX i ic – TX j jc
, and r ACO
are the total,
co-channel, and adjacent channel overlap ratios as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 493.
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks TX ic – TX jc i j
Dis tan ce
is the importance of the relationship between the TBA and its related cell with respect to the distance between
TX ic – TX jc i j
Dis tan ce
them.
TX ic – TX jc i j f Overlap
©Forsk 2015
is
calculated
TX ic – TX jc i j rO
=
as
explained
in
"Distance
if the frequency plan is taken into account and
Importance
Calculation"
TX ic – TX jc i j f Overlap
on
= 1 otherwise.
page 579.
From the constraint violation levels and the importance values of the relations between the TBA and its related cell, Atoll calculates the quality reduction factor for the pair as follows: QRF
TX ic – TX jc i j
TX ic – TX jc TX ic – TX jc TX ic – TX jc TX ic – TX jc TX ic – TX jc TX ic – TX jc i j i j j i j i j i j i + VL 2 + VL f = 1 – VL 1 Interference 1 Neighbours Overlap
The quality reduction factor is a measure of the cost of an individual relation. The total cost of the current physical cell ID plan for any TBA cell is given as follows, considering all the cells with which the TBA cell has relations: TX i ic
$ Total = 1 –
QRF
TX i ic – TX j jc
TX j jc
And, the total cost of the current physical cell ID plan for the entire network is simply the sum of the total TBA cell costs calculated above, i.e., $ Total =
TX i ic
$ Total
TX i ic
6.5.4.3 AFP Algorithm The AFP algorithm is an iterative algorithm which: • • • •
Calculates the cost (as described above) of the current physical cell ID plan, Tries different physical cell IDs to cells in order to reduce the costs, Memorises the different plans in order to determine the best plan, i.e., which provides the lowest total cost, Stops when it is unable to improve the cost of the network, and proposes the last known best physical cell ID plan as the solution.
6.5.5 Automatic PRACH RSI Planning Using the AFP The following describes the AFP’s automatic planning method for PRACH RSIs in an LTE network, which takes into account interference matrices, neighbour relations (first-order neighbours and optionally second-order neighbours), and distance between transmitters. The AFP takes into account the cells of all the TBC transmitters. The cells to be allocated will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, Their PRACH RSI status is not set to locked, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
6.5.5.1 Constraint and Relationship Weights The AFP is based on a cost-based function which takes into account various relations between each TBA cell and its related cells. Atoll calculates the cost between each individual TBA and related cell, and then the overall cost for the TBA cell. Related cells of a TBA cell are: •
Its neighbours, if the check box "Existing neighbours" is selected, Assigned weight Neighbour = 0.50 By adding an option in the Atoll.ini file (see the Administrator Manual), second-order neighbours can also be taken into account. In this case, the assigned weights are: Neighbour = 0.25 and 2nd – Neighbour = 0.10 .
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•
Cells that are listed in the interference matrix of the TBA cell, Assigned weight IM = 0.3
•
Cells within the cell’s (or the default) reuse distance, if the check box "Reuse distance" is selected, Assigned weight Dis tan ce = 0.2 The sum of the weights assigned to the above relations is 1.
You can modify these weights in your LTE document. The absolute values of the constraint weights are calculated from the relative weights (%) defined in the Weights dialogue as follows: % Neighbour Neighbour = ---------------------------------------------------------------------------------------------------------------------------------% Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce % 2nd – Neighbour 2nd – Neighbour = ---------------------------------------------------------------------------------------------------------------------------------% Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce % IM IM = ---------------------------------------------------------------------------------------------------------------------------------% Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce % Dis tan ce Dis tan ce = ---------------------------------------------------------------------------------------------------------------------------------% Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce
6.5.5.2 Cost Calculation Atoll calculates the constraint violation levels between the TBA cell TXi(ic) and its related cell TXj(jc) as follows: VL
TX i ic – TX j jc
PRACH
p Coll
PRACH
= Min 1 p Coll
TX i ic – TX j jc
N Common PRACH RSIs ID is the PRACH RSI collision probability given by p Coll = ----------------------------------------. TX i ic N Req PRACH RSIs TX ic – TX jc i j
TX ic i
Where N Common PRACH RSIs is the number of PRACH RSIs common between cells TXi(ic) and TXj(jc), and N Req PRACH RSIs is the number of PRACH RSIs required by the cell TXi(ic). Next, Atoll calculates the importance of the neighbour relations between the TBA cell and its related cell. TX i ic – TX j jc
Neighbours
TX i ic – TX j jc
= Neighbour Neighbour
TX i ic – TX j jc
Where Neighbour
+ 2nd – Neighbour 2nd – Neighbour TX i ic – TX j jc
is the importance of the relationship between the TBA cell and its related neighbour cell. Neighbour
is calculated during automatic neighbour planning by Atoll as explained in the Technical Reference Guide. For manual neighbour planning, this value is equal to 1. 2nd – Neighbour is calculated from the neighbour relationship importance values calculated during automatic neighbour planning. If the TBA cell has the same PRACH RSI assigned as one of its second-order neighbours, the importance of the PRACH RSI collision is the multiple of the importance values of the first order neighbour relations between the TBA cell and its second order neighbour. If the TBA cell is related to its second order neighbour through more than one first order neighbour, the importance is the highest value among all the multiples: 2nd – Neighbour =
TX ic – TX jc
j i Neighbour All Neighbour Pairs
Max
TX j jc – TX k kc
Neighbour
with Collisions
Where TX k kc is the second-order neighbour of TX i ic through TX j jc . Next, Atoll calculates the importance of the interference relations between the TBA cell and its related cell. TX i ic – TX j jc
Interference
TX i ic – TX j jc
= IM IM
TX i ic – TX j jc
+ Dis tan ce Dis tan ce
TX i ic – TX j jc
f Overlap
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 6: LTE Networks TX ic – TX jc i j
IM
TX ic – TX jc i j
IM
©Forsk 2015
is the importance of the relationship between the TBA cell and its related interfering cell calculated as follows: TX ic – TX jc i j
= r CCO
TX ic – TX jc i j
and IM
TX i ic – TX j jc
TX ic – TX jc i j
IM – CC
TX ic – TX jc i j
= IM – CC
TX i ic – TX j jc
IM – CC
and IM – CC
TX ic – TX jc i j
+ r ACO
TX ic – TX jc i j
IM – AC
if the frequency plan is taken into account
otherwise.
are respectively the co- and adjacent channel interference probabilities calculated as TX ic – TX jc i j
explained in "Interference Matrix Calculation" on page 578. r O
TX ic – TX jc i j
, r CCO
TX ic – TX jc i j
, and r ACO
are the total,
co-channel, and adjacent channel overlap ratios calculated as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 493. TX i ic – TX j jc
Dis tan ce
is the importance of the relationship between the TBA and its related cell with respect to the distance between
TX i ic – TX j jc
Dis tan ce
them.
TX i ic – TX j jc
f Overlap
is
calculated
TX i ic – TX j jc
= rO
as
explained
in
"Distance
Importance TX i ic – TX j jc
if the frequency plan is taken into account and f Overlap
Calculation"
on
page 579.
= 1 otherwise.
From the constraint violation levels and the importance values of the relations between the TBA and its related cell, Atoll calculates the quality reduction factor for the pair as follows: QRF
TX i ic – TX j jc
= 1 – VL
TX i ic – TX j jc
TX i ic – TX j jc
Interference
TX i ic – TX j jc
TX i ic – TX j jc
+ Neighbours f Overlap
The quality reduction factor is a measure of the cost of an individual relation. The total cost of the current PRACH RSI plan for any TBA cell is given as follows, considering all the cells with which the TBA cell has relations: TX i ic
QRF
$ Total = 1 –
TX i ic – TX j jc
TX j jc
And, the total cost of the current PRACH RSI plan for the entire network is simply the sum of the total TBA cell costs calculated above, i.e., $ Total =
TX i ic
$ Total
TX ic i
6.5.5.3 AFP Algorithm The AFP algorithm is an iterative algorithm which: • • • •
Calculates the cost (as described above) of the current PRACH RSI plan, Tries different PRACH RSIs to cells in order to reduce the costs, Memorises the different plans in order to determine the best plan, i.e., which provides the lowest total cost, Stops when it is unable to improve the cost of the network, and proposes the last known best PRACH RSI plan as the solution.
6.5.6 Appendices 6.5.6.1 Interference Matrix Calculation The co-channel interference probability is calculated as follows: S TX ic i
TX i ic – TX j jc
IM – CC
TX j jc TX i ic n C Max + M Quality Sym -------------------- ---------------------------------------------------- TX ic TX i ic TX ic TX i ic 10 10 i T i C – 10 Log 10 + 10 2N –n DLRS FB RSRP Sym
= --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX ic i
The adjacent channel interference probability is calculated as follows:
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S TX ic i
TX ic – TX jc i j
IM – AC
TX jc TX ic TX ic j i i n C Max + M Quality + f ACS Sym ------------------------------------------------------------------------------------------------ TX ic TX ic TX ic TX ic i 10 10 i i T i C 10 Log 10 + 10 2N DLRS – FB RSRP – n Sym
= ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX ic i
For frequencies farther than the adjacent channel, the interference probability is 0. TX i ic
TX i ic
Here S TX ic is the best server coverage area of the cell TXi(ic), that comprises all the pixels where E DLRS T RSRP i calculated in "Best Server Determination" on page 535. S TX ic i
Condition
as
is the best server coverage area of the cell TXi(ic)
TX i ic
TX j jc
where the given condition is true. C DLRS is the received downlink reference signal level from the cell TXi(ic). C Max TX i ic
received maximum signal level from the cell TXj(jc) calculated using the Max Power defined for this cell. n Sym TX ic i
subcarrier noise for the cell TXi(ic) as calculated in "Noise Calculation (DL)" on page 505 and N FB
is the
is the per-
is the total number of
frequency blocks defined in the frequency bands table for the channel bandwidth used by the cell. M Quality is the quality TX i ic
margin used for the interference matrices calculation. And, f ACS
is the adjacent channel suppression factor defined for the
frequency band of the cell TXi(ic).
6.5.6.2 Distance Importance Calculation TX ic – TX jc i j
The distance importance between two cells ( Dis tan ce
TX i ic – TX j jc
Dis tan ce
1 D Reuse 2 = Log -------------------------------- TX i ic – TX j jc D --------------------------------------------------------2 Log D Reuse
if D
) is calculated as follows:
TX ic – TX jc i j
1
Otherwise
Where D Reuse is the minimum reuse distance, either defined for each TBA cell individually or set for all the TBA cells in the AFP dialogue, and D follows: D D
TX i ic – TX j jc TX i ic – TX j jc
them. d
= d
TX i ic – TX j jc
TX i ic – TX j jc
is the weighted distance between the TBA cell TXi(ic) and its related cell TXj(jc) calculated as
1 + x cos – cos – 2
is weighted according to the azimuths of the TBA cell and its related cell with respect to the straight line joining
TX i ic – TX j jc
is the distance between the two cells considering any offsets with respect to the site locations. x is set TX i ic – TX j jc
to 10 % so that the maximum variation in D due to the azimuths does not exceed 40 %. and are calculated from the azimuths of the two cells as shown in Figure 6.8 on page 579.
Figure 6.8: Weighted Distance Between Cells The above formula implies that two cells facing each other will have a shorter effective distance between them than the real distance, and two cells pointing in opposite directions will have a greater effective distance.
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The importance of the distance relation is explained in Figure 6.9 on page 580. This figure shows that cells that are located near (based on the effective distance which is weighted by the orientations of the cells) have high importance, which is interpreted as a high cost, and cells that are located far have low importance. Cells that are further than the reuse distance do not have any cost related to the distance relation.
Figure 6.9: Importance Based on Distance Relation
580
Chapter 7 3GPP Multi-RAT Networks This chapter covers the following topics: •
"Definitions" on page 583
•
"Multi-RAT Monte Carlo Simulations" on page 583
•
"Multi-RAT Coverage Predictions" on page 585
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7 3GPP Multi-RAT Networks This chapter describes the calculations specific to 3GPP multi-RAT documents. Multi-RAT calculations that are the same as those in single-RAT documents can be found in: • • •
"GSM GPRS EDGE Networks" on page 125, "UMTS HSPA Networks" on page 211, and "LTE Networks" on page 445.
7.1 Definitions This table lists the input to coverage prediction and simulation calculations. Name
Value
Unit
Description
f act
UL
Service parameter
None
Uplink activity factor
f act
DL
Service parameter
None
Downlink activity factor
TL DL – GSM
Subcell parameter
%
Downlink traffic load (GSM)
7.2 Multi-RAT Monte Carlo Simulations The simulation process is divided into two steps. •
Generating a realistic user distribution as explained in "User Distribution" on page 583. Atoll generates user distributions as part of the Monte Carlo algorithm based on traffic data. The resulting user distribution complies with the traffic database and maps selected when creating simulations.
•
Scheduling and Radio Resource Management as explained under "Simulation Process" on page 585.
7.2.1 User Distribution During each simulation, Atoll performs two random trials. The first random trial generates the number of users and their activity status as explained in the following sections depending on the type of traffic input. • •
"Simulations Based on User Profile Traffic Maps" on page 584. "Simulations Based on Sector Traffic Maps" on page 584.
Once all the user characteristics have been determined, a second random trial is performed to obtain their geographical locations weighted according to the clutter classes, and whether they are indoor or outdoor according to the percentage of indoor users per clutter class. Atoll determines the total number of users attempting connection in each simulation based on the Poisson distribution. This may lead to slight variations in the total numbers of users in different simulations. To have the same total number of users in each simulation of a group, add the following lines in the Atoll.ini file: [Simulation] RandomTotalUsers=0 In 3GPP multi-RAT documents, services can be classified under constant bit rate and variable bit rate services, which can be provided by one or more technology. These service categories comprise the following service types in different technologies: Constant Bit Rate Services
Variable Bit Rate Services
GSM GPRS EDGE
Circuit Packet (Constant Bit Rate)
Packet (Max Bit Rate)
UMTS HSPA
Circuit R99 Packet HSPA (Constant Bit Rate)
Packet R99 Packet HSDPA (Best Effort) Packet HSPA (Best Effort)
LTE
Voice
Data
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Simulations Based on User Profile Traffic Maps User profile environment based traffic maps: Each pixel of the map is assigned an environment class which contains a list of user profiles with an associated mobility type and a given density, i.e., number of users of a user profile per km². User profile traffic maps: Each polygon or line of the map is assigned a density of users with a given user profile and mobility type. If the map is composed of points, each point is assigned a number of users with given user profile and mobility type. User profiles model the behaviour of the different user categories. Each user profile contains a list of services and parameters describing how these services are accessed by the user. The number of users of each user profile is calculated from the surface area (SEnv) of each environment class map (or each polygon) and the user profile density (DUP). N Users = S Env D UP •
In case of user profile traffic maps composed of lines, the number of users of each user profile is calculated from the line length (L) and the user profile density (DUP)
•
The number of users is a direct input when a user profile traffic map is composed of points.
(users per km): N Users = L D UP
Atoll calculates the probability for a user being active at a given instant in the uplink and in the downlink according to the service usage characteristics described in the user profiles, i.e., the number of service sessions, the average duration of each constant bit rate service session, or the volume of the data transfer in the uplink and the downlink in each variable bit rate service session as explained in: • •
GSM and LTE: "Simulations Based on User Profile Traffic Maps and Subscriber Lists" on page 476 UMTS: "Simulations Based on User Profile Traffic Maps" on page 225. For any variable bit rate service (j), once several numbers of users with different activity statuses have been calculated for different technologies, the final numbers of users are obtains as follows: inactive
Number of inactive users: n j
inactive
= Average n j
inactive
nj
GSM
Number of users active on UL: n j UL = Average n j UL
GSM
Number of users active on DL: n j DL = Average n j DL
GSM
inactive
UMTS
nj
n j UL
UMTS
n j DL
UMTS
Number of users active on UL+DL: n j UL + DL = Average n j UL + DL
LTE
n j UL
LTE
n j DL
LTE
GSM
n j UL + DL
UMTS
n j UL + DL
LTE
Simulations Based on Sector Traffic Maps Sector traffic maps are also referred to as live traffic maps. Live traffic data from the O&M is spread over the best server coverage areas of the transmitters included in the traffic map. Either throughput demands per service or the number of active users per service are assigned to the coverage areas of each transmitter. Atoll calculates the number of active users of each service UL and DL as follows: • •
GSM and LTE: "Simulations Based on Sector Traffic Maps" on page 478 UMTS: "Simulations Based on Sector Traffic Maps" on page 229.
Distribution of Terminals Terminals assigned to users depend on the percentages defined per traffic map and the technologies supported by each terminal. For example, if the percentages of terminals are defined as follows: Terminal A (GSM): 30 % Terminal B (GSM+UMTS): 50 % Terminal C (GSM+UMTS+LTE): 20 % For users of services that can be provided by GSM, UMTS, or LTE: Terminal A: 30 % Terminal B: 50 %
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Terminal C: 20 % For users of services that can be provided by UMTS or LTE: Terminal B: 50/70 = 71.4 % Terminal C: 20/70 = 28.6 % For users of services that can be provided by LTE only, Terminal C will be assigned.
7.2.2 Simulation Process Each Monte Carlo simulation is a snap-shot of the network where resource allocation is carried out. The steps of this algorithm are listed below. •
Serving cell/technology selection For each mobile, Atoll searches for a serving cell of each supported and available technology as follows: • • •
GSM: Atoll determines a best server based on the HCS layer/server selection algorithm. If no best server can be found, the mobile will be considered rejected by GSM. UMTS: Atoll determines a best server based on Ec/Io. If no best server can be found, the mobile will be considered rejected by UMTS. LTE: Atoll determines the best server based on RSRP or RS level and the serving cell selection method. If no best server can be found, the mobile will be considered rejected by LTE.
Once the potential serving technologies have been identified, Atoll selects the highest priority as defined in the service assigned to each mobile. The best server and technology assigned to each mobile remains unchanged for the rest of the simulation. •
Technology-wise Monte Carlo simulations as explained in: • • •
GSM: "Radio Resource Management in GSM" on page 184 UMTS: "Power Control Simulation" on page 231 LTE: "Scheduling and Radio Resource Management" on page 552
7.3 Multi-RAT Coverage Predictions Coverage predictions are calculated by determining the best server for each technology on each pixel and then determining the selected display parameter within the best server’s calculation area. Each pixel within the calculation area is considered a non-interfering receiver. The properties of the non-interfering probe receiver are set by selecting a terminal, a mobility type, and a service. The resolutions of coverage predictions do not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). 3GPP multi-RAT coverage predictions are combinations of corresponding single-RAT coverage predictions with specific parameter settings. Multi-RAT coverage predictions include: • •
Effective Service Area Analysis (DL+UL) Coverage by Throughput (DL)
Effective Service Area Analysis (DL+UL) The 3GPP multi-RAT effective service area is the combination of single-RAT effective service areas: •
GSM Service Area Analysis (DL) is based on a coverage by coding scheme, as explained in "GPRS/EDGE Coverage Predictions" on page 140 or on a coverage by codec modes, as explained in "Circuit Quality Indicators Coverage Predictions" on page 149, depending on the type of service. Radio conditions are evaluated over the HCS server area with a margin of 4 dB, on all the interfered subcells. Codec modes and coding schemes are obtained from these radio conditions based on C/I+N without ideal link adaptation (as explained in "Throughput Calculation Based on Interpolation Between C/N and C/(I+N)" on page 138). This implies that a frequency plan has to be defined in order to obtain this GSM/GPRS/EDGE coverage.
•
•
UMTS Effective Service Area Analysis (Eb⁄Nt) (DL+UL) is based on a combination of downlink and uplink service area predictions, as explained in "Downlink Service Area Analysis" on page 300 and "Uplink Service Area Analysis" on page 302. In the case of HSPA services, the coverage is based on a combination of HSDPA et HSUPA service areas as explained in "HSDPA Prediction Study" on page 304 and "HSUPA Prediction Study" on page 309. LTE Effective Service Area Analysis (DL+UL) is based on a combination of downlink and uplink service area predictions, as explained in "Effective Signal Analysis Coverage Predictions" on page 472.
Two display options are available for this prediction:
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• •
©Forsk 2015
Technologies: Each pixel displays the colour representing the visible technology having the highest priority defined in the selected service. Available Technologies: Pixels display the colour representing the combined areas over which a multi-technology terminal can be served. For instance, the GSM+UMTS area shows the union between the GSM and the UMTS service areas as explained above.
Coverage by Throughput (DL) The 3GPP multi-RAT throughput prediction is the combination of single-RAT throughput predictions: •
GSM Packet Throughput Analysis (DL) explained in "Application Throughput Calculation" on page 139 The 3GPP multi-RAT effective RLC throughput is obtained from the maximum effective RLC throughput of the GSM layer. The 3GPP multi-RAT application throughput from the maximum application throughput of the GSM layer.
•
R99 Service Area Analysis (Eb⁄Nt) (DL) explained in "Downlink Service Area Analysis" on page 300 and HSDPA Throughput Analysis (DL) explained in "HSDPA Prediction Study" on page 304 R99: The 3GPP multi-RAT effective RLC and application throughputs are respectively obtained from the effective RLC and application throughputs of the R99 layer (see "Downlink Service Area Analysis" on page 300 for more information). HSDPA: The 3GPP multi-RAT effective RLC and application throughputs are respectively obtained from the effective RLC and application throughputs of the HSDPA layer (see "HSDPA Prediction Study" on page 304 for more information).
•
LTE Coverage by Throughput (DL) explained in "C/(I+N)-based Coverage Predictions" on page 473 The 3GPP multi-RAT effective RLC and application throughputs are respectively obtained from the Effective RLC Channel Throughput (DL) and the Application Channel Throughput (DL) (see "C/(I+N)-based Coverage Predictions" on page 473 for more information).
Four display options are available for this prediction: • • • •
586
Effective RLC Throughput: The throughput on the RLC layer that a cell can provide to the selected terminal per pixel taking into account possible transmission errors (BLER) for the highest priority technology. Max Effective RLC Throughput: The maximum throughput on the RLC layer that a cell can provide to the selected terminal per pixel taking into account possible transmission errors (BLER), considering all available technologies. Application Throughput: The throughput on the application layer that a cell can provide to the selected terminal per pixel taking into account possible transmission errors (BLER) for the highest priority technology. Max Application Throughput: the maximum throughput on the application layer that a cell can provide to the selected terminal per pixel taking into account possible transmission errors (BLER), considering all available technologies.
Chapter 8 3GPP2 Multi-RAT Networks This chapter covers the following topics: •
"Definitions" on page 589
•
"Multi-RAT Monte Carlo Simulations" on page 589
•
"Multi-RAT Coverage Predictions" on page 591
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8 3GPP2 Multi-RAT Networks This chapter describes the calculations specific to 3GPP2 multi-RAT documents. Multi-RAT calculations that are the same as those in single-RAT documents can be found in: • •
"CDMA2000 Networks" on page 337, and "LTE Networks" on page 445
8.1 Definitions This table lists the input to coverage prediction and simulation calculations. Name
Value
Unit
Description
f act
UL
Service parameter
None
Uplink activity factor
DL
Service parameter
None
Downlink activity factor
f act
8.2 Multi-RAT Monte Carlo Simulations The simulation process is divided into two steps. •
Generating a realistic user distribution as explained in "User Distribution" on page 589. Atoll generates user distributions as part of the Monte Carlo algorithm based on traffic data. The resulting user distribution complies with the traffic database and maps selected when creating simulations.
•
Scheduling and Radio Resource Management as explained under "Simulation Process" on page 590.
8.2.1 User Distribution During each simulation, Atoll performs two random trials. The first random trial generates the number of users and their activity status as explained in the following sections depending on the type of traffic input. • •
"Simulations Based on User Profile Traffic Maps" on page 589. "Simulations Based on Sector Traffic Maps" on page 590.
Once all the user characteristics have been determined, a second random trial is performed to obtain their geographical locations weighted according to the clutter classes, and whether they are indoor or outdoor according to the percentage of indoor users per clutter class. Atoll determines the total number of users attempting connection in each simulation based on the Poisson distribution. This may lead to slight variations in the total numbers of users in different simulations. To have the same total number of users in each simulation of a group, add the following lines in the Atoll.ini file: [Simulation] RandomTotalUsers=0 In 3GPP2 multi-RAT documents, services can be classified under constant bit rate and variable bit rate services, which can be provided by one or more technology. These service categories comprise the following service types in different technologies: Constant Bit Rate Services
Variable Bit Rate Services
CDMA
Speech 1xRTT Data 1xEV-DO rev. 0 1xEV-DO rev. A (Guaranteed Bit Rate) 1xEV-DO rev. B (Guaranteed Bit Rate)
1xEV-DO rev. A (Best Effort) 1xEV-DO rev. B (Best Effort)
LTE
Voice
Data
Simulations Based on User Profile Traffic Maps User profile environment based traffic maps: Each pixel of the map is assigned an environment class which contains a list of user profiles with an associated mobility type and a given density, i.e., number of users of a user profile per km².
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User profile traffic maps: Each polygon or line of the map is assigned a density of users with a given user profile and mobility type. If the map is composed of points, each point is assigned a number of users with given user profile and mobility type. User profiles model the behaviour of the different user categories. Each user profile contains a list of services and parameters describing how these services are accessed by the user. The number of users of each user profile is calculated from the surface area (SEnv) of each environment class map (or each polygon) and the user profile density (DUP). N Users = S Env D UP •
In case of user profile traffic maps composed of lines, the number of users of each user profile is calculated from the line length (L) and the user profile density (DUP) (users per km): N Users = L D UP
•
The number of users is a direct input when a user profile traffic map is composed of points.
Atoll calculates the probability for a user being active at a given instant in the uplink and in the downlink according to the service usage characteristics described in the user profiles, i.e., the number of service sessions, the average duration of each constant bit rate service session, or the volume of the data transfer in the uplink and the downlink in each variable bit rate service session as explained in: • •
LTE: "Simulations Based on User Profile Traffic Maps and Subscriber Lists" on page 476 CDMA: "Simulations Based on User Profile Traffic Maps" on page 359. For any variable bit rate service (j), once several numbers of users with different activity statuses have been calculated for different technologies, the final numbers of users are obtains as follows: inactive
Number of inactive users: n j
inactive
= Average n j
inactive
CDMA
nj
Number of users active on UL: n j UL = Average n j UL
CDMA
Number of users active on DL: n j DL = Average n j DL
CDMA
LTE
n j UL
LTE
n j DL
LTE
Number of users active on UL+DL: n j UL + DL = Average n j UL + DL
CDMA
n j UL + DL
LTE
Simulations Based on Sector Traffic Maps Sector traffic maps are also referred to as live traffic maps. Live traffic data from the O&M is spread over the best server coverage areas of the transmitters included in the traffic map. Either throughput demands per service or the number of active users per service are assigned to the coverage areas of each transmitter. Atoll calculates the number of active users of each service UL and DL as follows: • •
LTE: "Simulations Based on Sector Traffic Maps" on page 478 CDMA: "Simulations Based on Sector Traffic Maps" on page 362.
8.2.2 Simulation Process Each Monte Carlo simulation is a snap-shot of the network where resource allocation is carried out. The steps of this algorithm are listed below. •
Serving cell/technology selection For each mobile, Atoll searches for a serving cell of each supported and available technology as follows: • •
CDMA: Atoll determines a best server based on Ec/Io. If no best server can be found, the mobile will be considered rejected by CDMA. LTE: Atoll determines the best server based on RSRP or RS level and the serving cell selection method. If no best server can be found, the mobile will be considered rejected by LTE.
Once the potential serving technologies have been identified, Atoll selects the highest priority as defined in the service assigned to each mobile. The best server and technology assigned to each mobile remains unchanged for the rest of the simulation. •
Technology-wise Monte Carlo simulations as explained in: • •
590
CDMA: "Simulations" on page 358 LTE: "Scheduling and Radio Resource Management" on page 552
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8.3 Multi-RAT Coverage Predictions Coverage predictions are calculated by determining the best server for each technology on each pixel and then determining the selected display parameter within the best server’s calculation area. Each pixel within the calculation area is considered a non-interfering receiver. The properties of the non-interfering probe receiver are set by selecting a terminal, a mobility type, and a service. The resolutions of coverage predictions do not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). 3GPP2 multi-RAT coverage predictions are combinations of corresponding single-RAT coverage predictions with specific parameter settings. Multi-RAT coverage predictions include: • •
Effective Service Area Analysis (DL+UL) Coverage by Throughput (DL)
Effective Service Area Analysis (DL+UL) The 3GPP2 multi-RAT effective service area is the combination of single-RAT effective service areas: •
•
CDMA Effective Service Area Analysis (Eb⁄Nt) (DL+UL) is based on a combination of downlink and uplink service area predictions, as explained in "Downlink Service Area Analysis" on page 413 and "Uplink Service Area Analysis" on page 417. LTE Effective Service Area Analysis (DL+UL) is based on a combination of downlink and uplink service area predictions, as explained in "Effective Signal Analysis Coverage Predictions" on page 472.
Two display options are available for this prediction: • •
Technologies: Each pixel displays the colour representing the visible technology having the highest priority defined in the selected service. Available Technologies: Pixels display the colour representing the combined areas over which a multi-technology terminal can be served. For instance, the CDMA+LTE area shows the union between the CDMA and the LTE service areas as explained above.
Coverage by Throughput (DL) The 3GPP2 multi-RAT throughput prediction is the combination of single-RAT throughput predictions: •
Service Area Analysis (Eb⁄Nt) (DL) explained in "Downlink Service Area Analysis" on page 413 The 3GPP2 multi-RAT effective RLC and application throughputs are respectively obtained from the effective RLC and application throughputs (see "Downlink Service Area Analysis" on page 300 for more information).
•
LTE Coverage by Throughput (DL) explained in "C/(I+N)-based Coverage Predictions" on page 473 The 3GPP multi-RAT effective RLC and application throughputs are respectively obtained from the Effective RLC Channel Throughput (DL) and the Application Channel Throughput (DL) (see "C/(I+N)-based Coverage Predictions" on page 473 for more information).
Four display options are available for this prediction: • • • •
Effective RLC Throughput: The throughput on the RLC layer that a cell can provide to the selected terminal per pixel taking into account possible transmission errors (BLER) for the highest priority technology. Max Effective RLC Throughput: The maximum throughput on the RLC layer that a cell can provide to the selected terminal per pixel taking into account possible transmission errors (BLER), considering all available technologies. Application Throughput: The throughput on the application layer that a cell can provide to the selected terminal per pixel taking into account possible transmission errors (BLER) for the highest priority technology. Max Application Throughput: the maximum throughput on the application layer that a cell can provide to the selected terminal per pixel taking into account possible transmission errors (BLER), considering all available technologies.
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Chapter 9 TD-SCDMA Networks This chapter covers the following topics: •
"Definitions and Formulas" on page 595
•
"Signal Level Based Calculations" on page 602
•
"Monte Carlo Simulations" on page 608
•
"TD-SCDMA Prediction Studies" on page 626
•
"Smart Antenna Modelling" on page 638
•
"N-Frequency Mode and Carrier Allocation" on page 650
•
"Neighbour Allocation" on page 651
•
"Scrambling Code Allocation" on page 656
•
"Automatic GSM/TD-SCDMA Neighbour Allocation" on page 666
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9 TD-SCDMA Networks This chapter describes in detail the algorithms, calculation parameters, and processes of the coverage predictions and the simulations available in TD-SCDMA documents. The first part of this chapter lists all the input and output parameters in the TD-SCDMA documents, their significance, location in the Atoll GUI, and their usage. Detailed explanation of the basic coverage predictions, which do not require simulation results, is provided in the second part. The third part describes the traffic scenario generation and Montel Carlo simulation algorithms including smart antenna modelling and dynamic channel allocation. The next sections are dedicated to TD-SCDMA coverage predictions which can be based on results obtained from simulations. The last three sections describe in detail the allocation of frequencies, i.e., master and slave carriers, the allocation of neigbours, and the allocation of scrambling codes.
9.1 Definitions and Formulas The tables in the following subsections list the input and output parameters and formulas used in simulations and other computations.
9.1.1 Inputs This table lists the inputs to computations, coverage predictions, and simulations. Name
Value
Unit
Description
R Ch
Global parameter
Mcps
Chip rate (or Spreading rate) (1.28)
Spread
Global parameter
None
Minimum spreading factor (1)
F Max
Spread
Global parameter
None
Maximum spreading factor (16)
Proc
Global parameter
None
P-CCPCH processing gain (13.8 dB)
N TS
SF
Global parameter
None
Number of timeslots per subframe (7)
SF
Global parameter
ms
Subframe duration (5)
Frame
Global parameter
ms
Frame duration (10)
N Ch TS
GP
Global parameter
None
Number of guard period chips per timeslot (16)
N Ch TS
Data
Global parameter
None
Number of data chips per timeslot (704)
Midamble
Global parameter
None
Number of midamble chips per timeslot (144)
N Ch PTS
Global parameter
None
Number of guard period chips per pilot timeslot (96)
N Ch DwPTS
GP
Global parameter
None
Number of guard period chips per DwPTS timeslot (32)
SYNC_DL
Global parameter
None
Number of SYNC_DL chips per DwPTS timeslot (64)
None
Total number of chips per DwPTS timeslot (96)
F Min
G P – CCPCH
D D
N Ch TS GP
N Ch DwPTS Total
N Ch DwPTS
Global parameter Total N Ch DwPTS
GP
SYNC_DL
= N Ch DwPTS + N Ch DwPTS
N Ch UpPTS
GP
Global parameter
None
Number of guard period chips per UpPTS timeslot (32)
SYNC_UL
Global parameter
None
Number of SYNC_UL chips per UpPTS timeslot (128)
None
Total number of chips per UpPTS timeslot (160)
N Ch UpPTS Total
N Ch UpPTS
Global parameter Total N Ch UpPTS
GP
SYNC_UL
= N Ch UpPTS + N Ch UpPTS
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Name
©Forsk 2015
Value
Unit
Description
Calculated global parameter Data
W
N Ch TS W = --------------SF D
bps
Chip rate (140800 bps)
F Avg
Frequency band parameter
MHz
Average frequency range of the frequency band (2010)
BW
Frequency band parameter
MHz
Channel bandwidth of the carriers of a frequency band (1.6)
F IRF
Cell parameter
None
Interference reduction factor
F JD
Site equipment parameter
None
Joint Detection (JD) factor
TX
Site equipment parameter
None
Multi-Cell Joint Detection factor
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
None
BTS Noise Figure
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
None
Transmitter loss L Tx = L Total – UL on uplink
TX
BTS parameter
None
Percentage of BTS signal correctly transmitted
P TCH
Max
Cell parameter
W
Maximum cell traffic timeslot power
P P – CCPCH
Cell parameter
W
P-CCPCH power on TS0
P DwPCH
Cell parameter
W
DwPCH power on DwPTS
P OCCH – TS0
Cell parameter
W
Other common channel power on TS0
TComp P – CCPCH
Cell parameter
None
P-CCPCH RSCP comparative threshold for baton handover
P Max
Cell parameter
None
Maximum difference between two transmitted powers
Req
Cell parameter
None
Required resource units in uplink
RU DL
Req
Cell parameter
None
Required resource units in downlink
P HS – PDSCH
Available
Cell parameter
W
HS-PDSCH power available per downlink timeslot
P HR
Cell parameter
None
Power headroom
P HS – SCCH
Cell parameter
W
HS-SCCH power per downlink timeslot
N HS – SCCH
Cell parameter
None
Number of HS-SCCH channels
N HS – SICH
Cell parameter
None
Number of HS-SICH channels
Max
Cell parameter
None
Maximum number of HSDPA users
N HS-PDSCH Codes
Min
Cell parameter
None
Minimum number of HS-PDSCH codes
Max
Cell parameter
None
Maximum number of HS-PDSCH codes
Max
Cell parameter
None
Maximum number of intratechnology neighbours
Max
Cell parameter
None
Maximum number of intertechnology neighbours
TX
F MCJD NF
L
TX
TX
RU UL
N HSDPA
N HS-PDSCH Codes N Intra – Neigh N Intra – Neigh
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Name
Value
Unit
Description
RSCP P – CCPCH
Min
Cell parameter or Global parameter
W
The minimum P-CCPCH RSCP required for a user to be connected to the cell
P OCCH
Timeslot parameter
W
Other common channel power
DL
Timeslot parameter
W
Downlink traffic power
Timeslot parameter (Simulation constraint)
None
Maximum percentage of downlink used power
Timeslot parameter (Simulation result)
None
Uplink load factor
Timeslot parameter (Simulation constraint)
None
Maximum uplink load factor
P HS – PDSCH
Timeslot parameter
W
HS-PDSCH power available
Min
Timeslot parameter
None
Minimum number of HS-PDSCH codes
N HS-PDSCH Codes
Max
Timeslot parameter
None
Maximum number of HS-PDSCH codes
RU Overhead
Timeslot parameter
P TCH Max
%P DL X UL
Max
X UL
Available
N HS-PDSCH Codes
Overhead resource units
Body
Service parameter
None
Body loss
Act
Service parameter
None
Downlink activity factor for circuitswitched services and the A-DPCH activity factor for HSDPA services
f UL
Act
Service parameter
None
Uplink activity factor for circuitswitched services and the A-DPCH activity factor for HSDPA services
f DL
Eff
Service parameter
None
Downlink efficiency factor for circuitswitched services
f UL
Eff
Service parameter
None
Uplink efficiency factor for circuitswitched services
F Scaling
Service parameter
None
Application througput scaling factor
O TP
Service parameter
kbps
Application throughput offset
UL
Service parameter (packet session modelling)
None
Average number of packet calls on the uplink during a session
DL
Service parameter (packet session modelling)
None
Average number of packet calls on the downlink during a session
UL
Service parameter (packet session modelling)
ms
Average time between two packet calls on the uplink
T PacketCall
DL
Service parameter (packet session modelling)
ms
Average time between two packet calls on the downlink
UL
Service parameter (packet session modelling)
KBytes
Minimum packet call size on the uplink
DL
Service parameter (packet session modelling)
KBytes
Minimum packet call size on the downlink
UL
Service parameter (packet session modelling)
KBytes
Maximum packet call size on the uplink
S Max – PacketCall
DL
Service parameter (packet session modelling)
KBytes
Maximum packet call size on the downlink
T Packet
UL
Service parameter (packet session modelling)
ms
Average time between two packets on the uplink
DL
Service parameter (packet session modelling)
ms
Average time between two packets on the downlink
L
f DL
N PacketCall N PacketCall T PacketCall
S Min – PacketCall S Min – PacketCall S Max – PacketCall
T Packet
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Name
©Forsk 2015
Value
Unit
Description
UL
Service parameter (packet session modelling)
Bytes
Packet size on uplink
DL
Service parameter (packet session modelling)
Bytes
Packet size on downlink
Nom
R99 bearer parameter
kbps
Downlink peak throughput
Nom
R99 bearer parameter
kbps
Uplink peak throughput
WR99 bearer parameter (Can be calculated as ----------) Nom R DL
None
Downlink processing gain
WR99 bearer parameter (Can be calculated as ----------) Nom R UL
None
Uplink processing gain
Min
R99 bearer parameter
W
Allowed minimum downlink traffic channel power
Max
R99 bearer parameter
W
Allowed maximum downlink traffic channel power
N DL
TS
R99 bearer parameter
None
Number of downlink timelots
TS
R99 bearer parameter
None
Number of uplink timelots
E Req C Req R99 bearer parameter per mobility ( ----b- or --- ) N t TCH – UL I TCH – UL
None
Eb/Nt or C/I target on uplink
E Req C Req R99 bearer parameter per mobility ( ----b- or --- ) N t TCH – DL I TCH – DL
None
Eb/Nt or C/I target on downlink
Req
R99 bearer parameter per mobility
W
Target RSCP on uplink TCH
Req
R99 bearer parameter per mobility
W
Target RSCP on downlink TCH
Div
R99 bearer parameter per mobility
None
Downlink diversity gain
Div
R99 bearer parameter per mobility
None
Uplink diversity gain
Term
Terminal parameter
W
Maximum terminal power
P Min
Term
Terminal parameter
W
Minimum terminal power
P UpPCH
Terminal parameter
W
UpPCH power
Term
Terminal parameter
None
Terminal Noise Figure
Term
Terminal parameter
None
Joint Detection (JD) factor
Term
Terminal parameter
None
Percentage of terminal signal correctly transmitted
Term
Terminal parameter
None
Terminal gain
Term
Terminal parameter
None
Terminal loss
TAdd P – CCPCH
Mobility parameter
W
Required RSCP T_Add for P-CCPCH
TDrop P – CCPCH
Mobility parameter
W
Required RSCP T_Drop for P-CCPCH
Req
Mobility parameter
W
Required RSCP threshold for DwPCH
Req
Mobility parameter
W
Required RSCP threshold for UpPCH
E Req C Req Mobility parameter ( ----b- or --- ) N t P – CCPCH I P – CCPCH
None
Required quality threshold for PCCPCH
S Packet S Packet R DL
R UL
Proc
G DL
Proc
G UL
P TCH – DL P TCH – DL
N UL Req
Q TCH – UL Req
Q TCH – DL RSCP TCH – UL RSCP TCH – DL G DL
G UL
P Max
NF
F JD
G L
RSCP DwPCH RSCP UpPCH Req
Q P – CCPCH
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Name
Value
Unit
Description
E Req Mobility parameter ( ----c- ) N t HS – SCCH
None
Required quality threshold for HSSCCH
E P – CCPCH Mobility parameter ( ----c- ) N t HS – SICH
None
Required quality threshold for PCCPCH
C Req Mobility parameter ( --- ) I DwPCH
None
Required quality threshold for DwPCH
Clutter class parameter
None
Model standard deviation
Clutter class parameter
None
P-CCPCH Eb/Nt or C/I standard deviation
Clutter class parameter
None
Downlink Eb/Nt or C/I standard deviation
Clutter class parameter
None
Uplink Eb/Nt or C/I standard deviation
Clutter (and, optionally, frequency band) parameter
None
Indoor loss
Ortho
Clutter class parameter
None
Downlink orthogonality factor
F UL
Ortho
Clutter class parameter
None
Uplink orthogonality factor
Spread
Clutter class parameter
°
Spreading angle
K
1.38 x 10-23
J/K
Boltzman constant
T
293
K
Ambient temperature
TX
NFTX K T BW
W
Thermal noise at transmitter
Term
NF Term K T BW
W
Thermal noise at terminal
TX
Antenna parameter
None
Transmitter antenna gain
Propagation model result
None
Path loss
Result calculated from cell edge coverage probability and model standard deviation
None
Model shadowing margin used in coverage predictions
P – CCPCH
Result calculated from cell edge coverage probability and P-CCPCH Eb/Nt standard deviation
None
P-CCPCH Eb/Nt shadowing margin used in coverage predictions
Eb Nt DL
Result calculated from cell edge coverage probability and DL Eb/Nt standard deviation
None
DL Eb/Nt shadowing margin used in coverage predictions
Eb Nt UL
Result calculated from cell edge coverage probability and UL Eb/Nt standard deviation
None
UL Eb/Nt shadowing margin used in coverage predictions
Req
Q HS – SCCH Req
Q HS – SICH Req
Q DwPCH
Model
Eb/Nt
P – CCPCH or CI P – CCPCH CI
Eb/Nt
or DL
Eb/Nt
or UL
DL
CI
UL
L Indoor F DL
N0 N0
G
L Path Model
M Shadowing M Shadowing M Shadowing M Shadowing
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Name
Value
Unit
For RSCP calculation Model
LT
TX
Term
Body
Transmitter-terminal total loss in coverage predictions
Model M Shadowing
L Path L L L L Indoor = ---------------------------------------------------------------------------------------------------------------------TX Term G G
In UL, only carrier power is Eb Nt UL
For P-CCPCH Eb/Nt calculation TX
Term
attenuated by M Shadowing .
P – CCPCH
Body
L Path L L L L Indoor M Shadowing = ---------------------------------------------------------------------------------------------------------------------TX Term G G
Eb Nt P
LT LT
None
For DL Eb/Nt calculation Eb Nt DL
LT
TX
Term
Eb Nt UL
LT
Eb Nt DL
P – CCPCH
extra-cell interference is not. Eb Nt
For UL Eb/Nt calculation Term
In DL, carrier power and intra-cell interference are attenuated by M Shadowing or M Shadowing while
Eb Nt DL
Body
L Path L L L L Indoor M Shadowing = ---------------------------------------------------------------------------------------------------------------------TX Term G G
TX
Description
Eb Nt UL
Body
DL
Therefore, M Shadowing or
L Path L L L L Indoor M Shadowing = ---------------------------------------------------------------------------------------------------------------------TX Term G G
P – CCPCH
M Shadowing are set to 1 in DL extracell interference calculation.
9.1.2 P-CCPCH Eb/Nt and C/I Calculation Name
Value
E b TX i ic --- N t P – CCPCH
RSCP P – CCPCH ------------------------------------------------ G Proc P – CCPCH TX i ic N Tot – DL
TX i ic
RSCP P – CCPCH -----------------------------------------------TX i ic N Tot – DL
TX
TX i ic
N Tot – DL
TX i ic
Term
I Intra – DL + I Extra – DL + I IC – DL ic jc + N 0 TX ic i
RSCP P – CCPCH TX i ic
I Intra – DL
With
TX i
=
TX i
TX i ic
I IC – DL ic jc
TX
i
TX ic i
+ RSCP OCCH – TS0 Ortho
1 – F DL
= 0 1
I Extra – DL
None
P-CCPCH Eb/Nt for the cell TX i ic
None
P-CCPCH C/I for the cell TX i ic
W
Downlink total noise for the cell TX i ic
W
Downlink intra-cell interference for the cell TX i ic
W
Downlink extra-cell interference for the cell TX i ic
W
Inter-carrier interference
Unit
Description
None
DwPCH C/I for the cell TX i ic
W
Downlink total noise for the cell TX i ic
TX i ic
TX i
TX i ic
Description
TX ic i
i
C --- I P – CCPCH
Unit
Term
1 – F JD
TX
i
and
Without Useful Signal Total Noise TX j ic
TX j ic
TX j jc
TX j jc
RSCPP – CCPCH + RSCPOCCH – TS0 ji
RSCPP – CCPCH + RSCPOCCH – TS0 TX
j --------------------------------------------------------------------------------------F IRF ic jc
9.1.3 DwPCH C/I Calculation Name
Value TX i
TX i ic
TX i ic
N Tot – DL
600
TX i ic
RSCP DwPCH ------------------------------------------TX i ic N Tot – DL
C --- I DwPCH TX i ic
TX i ic
Term
I Intra – DL + I Extra – DL + I IC – DL ic jc + N 0
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Name
Value TX ic i
RSCP DwPCH TX ic i I Intra – DL
With
TX
i
=
TX
i
Ortho
1 – F DL
= 0 1
TX
Description
W
Intra-cell interference for the cell TX i ic
W
Extra-cell interference for the cell TX i ic
W
Inter-carrier interference
Unit
Description
None
Downlink TCH Eb/Nt for the cell TX i ic
None
Downlink TCH C/I for the cell TX i ic
W
Downlink total noise for the cell TX i ic
W
Downlink intra-cell interference for the cell TX i ic
W
Downlink extra-cell interference for the cell TX i ic
W
Inter-carrier interference
Unit
Description
None
Uplink TCH Eb/Nt for the cell TX i ic
None
Uplink TCH C/I for the cell TX i ic
W
Uplink required power for the terminal
i Term
1 – F JD
and
Without Useful Signal Total Noise TX j ic
RSCPDwPCH
TX i ic
I Extra – DL
Unit
ji
TX j jc
RSCPDwPCH
I IC – DL ic jc
TX
j ---------------------------------------F IRF ic jc
9.1.4 DL TCH Eb/Nt and C/I Calculation Name
Value TX i ic
TX i
TX i ic
RSCP TCH – DL Div ---------------------------------------------- G Proc DL G DL TX i ic N Tot – DL
TX i ic
RSCP TCH – DL ---------------------------------------------- G Div DL TX i ic N Tot – DL
E b --- N t TCH – DL
TX i ic
N Tot – DL
TX i ic
I Intra – DL
TX i ic
I Extra – DL
I IC – DL ic jc
TX i ic
TX i
C --- I TCH – DL TX i ic
TX i ic
Term
I Intra – DL + I Extra – DL + I IC – DL ic jc + N 0
TX i TXi Ortho Term 1 – F DL 1 – F JD + 1 – TX ic
TX ic
i i RSCP TCH – DL + RSCP OCCH TX j ic
TX j ic
TX j jc
TX j jc
RSCPTCH – DL + RSCPOCCH ji
RSCPTCH – DL + RSCPOCCH TX
j --------------------------------------------------------------------------F IRF ic jc
9.1.5 UL TCH Eb/Nt and C/I Calculation Name
Value TX i ic
Term
TX i ic
RSCP TCH – UL Div ------------------------------------------------- G Proc UL G UL TX i ic N Tot – UL
i C --- I TCH – UL
TX ic
RSCP TCH – UL ------------------------------------------------- G Div UL TX i ic N Tot – UL
Term P Req
Q TCH – UL Q TCH – UL Term - or P Term P Max --------------------------Max ------------------------TX i ic TX i ic E C b --- ----- I TCH – UL N t TCH – UL
E b --- N t TCH – UL
Term
Req
TX i ic
Req
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9.1.6 Interference Calculation Name
Value TX jc j
I C2C TX i TX j
TX j ic
TX j ic
Description
W
Cell to cell interference
W
UpPCH interference
Unit
Description
W
HS-SCCH power
W
HS-PDSCH power
W
HS-SICH power
TX jc j
RSCPTCH – DL + RSCPOCCH
j RSCPTCH – DL + RSCPOCCH +--------------------------------------------------------------------------F IRF ic jc TX
Unit
TX
j TX i
TX i ic
N0
I TS1 – UL
TX i ic
X TS1 – UL ---------------------------------TX ic 1 – X i TS1 – UL
9.1.7 HSDPA Dynamic Power Calculations Name
Value TX i ic
TX ic
TX ic
Ec i i i --- N t HS – SCCH N Tot – DL – RSCP HS – SCCH ----------------------------------------------------------------------------------------------------------------------------- L Model T TX i
TX i ic
P HS – SCCH TX ic i
TX ic i
TX
TX ic i
TX ic i
P Max – DL – Eff – P R99 – DL – P HR
P HS – PDSCH
TX i ic
TX ic
TX ic i
– P HS – SCCH
Ec i i i --- N t HS – SICH N Tot – UL – RSCP HS – SICH -------------------------------------------------------------------------------------------------------------------------- L Model T Mi
Mi
P HS – SICH
M
M
9.2 Signal Level Based Calculations Two types of signal level based calculations are available in Atoll: 1. Point Analysis: Real-time calculations for profile and reception analysis using the mouse to move a probe mobile on the map. 2. RSCP Based Coverage Predictions: Calculation of RSCP related parameters on each pixel and colouring according to the selected display.
9.2.1 Point Analysis For the selected transmitted TXi and carrier (ic), you can study three parameters in point analysis Profile tab: Study criteria
Formulas Signal level received from a transmitter on a carrier (cell)
Signal level ( RSCP ) in dBm
RSCP
TX ic i
TX ic i
Model
– L Path – M Shadowing – L Indoor TX i
Path loss ( L Path ) in dB Total losses ( L T ) in dB
= EIRP
L Path = L Model + L Ant L T = L Path + L
TX i
Model
+ L Indoor + M Shadowing – G
TX i
Where, RSCP is the received signal code power for the P-CCPCH. EIRP is the effective isotropic radiated power of the transmitter. EIRP
TX i ic
TX i ic
= P P – CCPCH + G
TX i
–L
TX i
ic is a carrier number L Model is the loss on the transmitter-receiver path (path loss) calculated by the propagation model
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i
L Ant is the transmitter antenna attenuation (from antenna patterns) Model
M Shadowing is the shadowing margin. This parameter is taken into account when the option “Shadowing taken into account” is selected L Indoor are the indoor losses, taken into account when the option "Indoor coverage" is selected G L
TX i
TX i
is the transmitter antenna gain is the transmitter loss ( L
TX i
= L Total – DL )
It is possible to analyse the best carrier. In this case, Atoll takes the highest P-CCPCH power of cells to calculate the signal level received from a transmitter.
9.2.1.1 Profile Tab TX i ic
Atoll displays either the signal level received from the selected transmitter on a carrier ( RSCP P – CCPCH ), or the highest signal level received from the selected transmitter on the best carrier. For a selected transmitter, it is also possible to study the path loss, L Path , or the total losses, L T . Path loss and total losses are the same on any carrier.
9.2.1.2 Reception Tab Analysis provided in the Reception tab is based on path loss matrices. You can study reception from TBC transmitters for which path loss matrices have been calculated on their calculation areas. TX i ic
For each transmitter, Atoll displays either the signal level received on a carrier, ( RSCP P – CCPCH ), or the highest signal level received on the best carrier. Received signal level bar graphs are displayed in a decreasing signal level order. The number of bars in the graph depends on the signal level received from the best server. Only bars for transmitters whose signal level is within a 30 dB margin from the best server signal are displayed. You can use a value other than 30 dB for the margin from the best server signal level, for example a smaller value for improving the calculation speed. For more information on defining a different value for this margin, see the Administrator Manual.
9.2.2 RSCP Based Coverage Predictions For each TBC transmitter, TXi, Atoll determines the value of the selected parameter on each studied pixel inside the TXi calculation area. Each pixel within the TXi calculation area is considered a probe receiver. Coverage study parameters to be set are: • •
The study conditions to determine the service area of each TBC transmitter The display settings to for colouring the covered pixels
Atoll uses the parameters entered in the Condition tab of the coverage study properties dialogue to determine pixels covered by the each transmitter. Coverage prediction display resolution is independent of the path loss matrix and geographic data resolutions, and can be different for each coverage prediction. Coverage predictions are calculated using bilinear interpolation of multi-resolution path loss matrices (similar to the evaluation of site altitudes).
9.2.2.1 Calculation Criteria The RSCP from a transmitter TXi and a selected carrier (ic) is given by: RSCP
TX i ic
= EIRP
TX i ic
Model
– L Path – M Shadowing – L Body – L Indoor + G
Term
–L
Term
Where,
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RSCP is the received signal code power. RSCP can be calculated for P-CCPCH, DwPCH, or the downlink TCH. EIRP is
the
TX ic i EIRP DwPCH
=
effective TX ic i P DwPCH
+G
isotropic TX
i
–L
TX
i
, or
radiated
power
TX ic i EIRP DL – TCH
=
of
the
TX ic i P DL – TCH
+G
transmitter. TX
i
–L
TX
i
TX ic i
TX ic i
EIRP P – CCPCH = P P – CCPCH + G
TX
i
–L
TX
i
,
.
ic is a carrier number TX i
L Path = L Model + L Ant L Model is the loss on the transmitter-receiver path (path loss) calculated by the propagation model TX i
L Ant is the transmitter antenna attenuation (from antenna patterns) Model
M Shadowing is the shadowing margin. This parameter is taken into account when the option “Shadowing taken into account” is selected L Indoor are the indoor losses, taken into account when the option "Indoor coverage" is selected L
Term
is the terminal loss
L Body is the body loss defined in the service G G L
Term TX i
TX i
is the receiver total gain
is the transmitter antenna gain is the transmitter loss ( L
TX i
= L Total – DL )
9.2.2.2 P-CCPCH RSCP Coverage Prediction 9.2.2.2.1
Coverage Condition This coverage prediction calculates and displays the Received Signal Code Power (RSCP) for the P-CCPCH. The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for TS0. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest PCCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the RSCP considering: • • •
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
You can select the display colours according to the RSCP, or on any best server parameter.
9.2.2.2.2
Coverage Display It is possible to colour the transmitter service areas using a unique colour per transmitter, or colour the pixels in the coverage areas by any transmitter attribute or other criteria such as: •
Best Signal Level (dBm) TX i ic
Atoll calculates the best RSCP P – CCPCH received from each transmitter TX i ic on each pixel. Where other service areas overlap the studied one, Atoll chooses the highest RSCP. A pixel of a service area is coloured if the RSCP level is greater than or equal to the defined thresholds. The pixel colour depends on the RSCP level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the RSCP from the best server exceeds a defined minimum threshold. •
RSCP Margin (dB) Coverage consists of several layers with a layer per user-defined RSCP margin defined in the Display tab (Prediction TX i ic
RSCP
properties). For each layer, area is covered if RSCP P – CCPCH – TAdd P – CCPCH Mobility M P – CCPCH . Each layer is assigned a colour and displayed with intersections between layers.
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•
Cell Edge Coverage Probability (%) TX ic i
On each pixel of each transmitter service area, the coverage corresponds to the pixels where the RSCP P – CCPCH from the transmitter exceeds TAdd P – CCPCH defined in the mobility selected in the Conditions tab, with different cell edge coverage probabilities. There is one coverage area per transmitter in the explorer.
9.2.2.3 Best Server P-CCPCH Coverage Prediction This coverage prediction calculates and displays the best server RSCP for the P-CCPCH. The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for TS0. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the RSCP considering: • • •
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
The pixels in the TX i ic TX i ic
RSCP P – CCPCH =
TX i ic
Min
coverage area where RSCP P – CCPCH Max (TAdd P – CCPCH,RSCP P – CCPCH)
and where
Best RSCP TXj jc will be covered and coloured according to the transmitter colour. P – CCPCH j = All
9.2.2.4 P-CCPCH Pollution Analysis Coverage Prediction This coverage prediction calculates and displays the number of P-CCPCH polluters. Atoll calculates the Received Signal Code TX i ic
Power (RSCP) for the P-CCPCH for each pixel in the TX i ic coverage area where RSCP P – CCPCH TAdd P – CCPCH Mobility and determines the polluting transmitters according to: TX i ic TX j jc RSCP P – CCPCH Best RSCP P – CCPCH – M ji
Where M is the specified pollution margin. The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for TS0. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest PCCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the RSCP considering: • • •
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
Atoll determines the number of transmitters covering each pixel and colours the pixel according to the number of polluting transmitters. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the number of servers is greater than or equal to a defined minimum threshold.
9.2.2.5 DwPCH RSCP Coverage Prediction 9.2.2.5.1
Coverage Condition This coverage prediction calculates and displays the Received Signal Code Power (RSCP) for the DwPCH. The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for DwPTS. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the RSCP considering: • • •
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
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The pixels in the TX i ic TX ic i
©Forsk 2015 TX ic i
Min
coverage area where RSCP P – CCPCH Max (TAdd P – CCPCH,RSCP P – CCPCH)
and where
Req
RSCP DwPCH RSCP DwPCH Mobility are covered and coloured according to the selected display parameter.
9.2.2.5.2
Coverage Display It is possible to colour the transmitter service areas using a unique colour per transmitter, or colour the pixels in the coverage areas by any transmitter attribute or other criteria such as: •
DwPCH RSCP (dBm) TX i ic
Atoll calculates the best RSCP DwPCH received from each transmitter TX i ic on each pixel.. Where other service areas overlap the studied one, Atoll chooses the highest RSCP. A pixel of a service area is coloured if TX i ic
Req
RSCP DwPCH RSCP DwPCH Mobility . The pixel colour depends on the RSCP level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the RSCP from the best server exceeds a defined minimum threshold. •
RSCP Margin (dB) Coverage consists of several layers with a layer per user-defined RSCP margin defined in the Display tab (Prediction TX ic i
Req
RSCP
properties). For each layer, area is covered if RSCP DwPCH – RSCP DwPCH Mobility M DwPCH . Each layer is assigned a colour and displayed with intersections between layers. •
Cell edge coverage probability (%) TX ic i
On each pixel of each transmitter service area, the coverage corresponds to the pixels where the RSCP DwPCH from TX i ic
the transmitter TX i ic exceeds RSCP DwPCH defined in the mobility selected in the Conditions tab, with different cell edge coverage probabilities. There is one coverage area per transmitter in the explorer.
9.2.2.6 UpPCH RSCP Coverage Prediction 9.2.2.6.1
Coverage Condition This coverage prediction calculates and displays the Received Signal Code Power (RSCP) for the UpPCH in the uplink. The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for UpPTS. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the RSCP considering: • • •
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
Atoll uses the UpPCH power of the selected terminal to calculate the RSCP from each pixel of each transmitter’s best server coverage area. TX i ic
Min
Term
Req
The pixels where RSCP P – CCPCH Max (TAdd P – CCPCH,RSCP P – CCPCH) and where RSCP UpPCH RSCP UpPCH Mobility are covered and coloured according to the selected display parameter.
9.2.2.6.2
Coverage Display It is possible to colour the transmitter service areas using a unique colour per transmitter, or colour the pixels in the coverage areas by any transmitter attribute or other criteria such as: •
UpPCH RSCP (dBm) Term
Atoll calculates the best RSCP UpPCH received from each pixel of each transmitter service area at the transmitter. Where other service areas overlap the studied one, Atoll chooses the highest RSCP. A pixel of a service area is coloured Term
Req
if RSCP UpPCH RSCP UpPCH Mobility . The pixel colour depends on the RSCP level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the RSCP at the best server exceeds a defined minimum threshold. •
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Coverage consists of several layers with a layer per user-defined RSCP margin defined in the Display tab (Prediction Term
Req
RSCP
properties). For each layer, area is covered if RSCP UpPCH – RSCP UpPCH Mobility M UpPCH . Each layer is assigned a colour and displayed with intersections between layers. •
Cell Edge Coverage Probability (%) Term
On each pixel of each transmitter service area, the coverage corresponds to the pixels from which the RSCP UpPCH at Term
the transmitter exceeds RSCP UpPCH defined in the mobility selected in the Conditions tab, with different cell edge coverage probabilities. There is one coverage area per transmitter in the explorer.
9.2.2.7 Baton Handover Coverage Prediction 9.2.2.7.1
Coverage Condition This coverage prediction determines the pixels which receive RSCP from cells other than the best server high enough to perform baton handovers. Received Signal Code Power (RSCP) is calculated for the P-CCPCH. The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for TS0. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the RSCP considering: • • • The
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters. pixels
TX ic i RSCP P – CCPCH
9.2.2.7.2
are
covered
and
coloured
TAdd P – CCPCH Mobility and
according
TX jc j RSCP P – CCPCH
to
the
selected
TDrop P – CCPCH Mobility –
display
parameters,
TX jc j TComp P – CCPCH
where
.
Coverage Display It is possible to display the potential handover areas or the number of transmitters covering each pixel. •
Handover Areas Atoll displays the pixels where there are transmitters other than the best server that satisfy the above criteria. Coverage consists of a single layer with a defined colour whose visibility in the workspace can be managed.
•
Number of Potential Servers Atoll determines the number of transmitters covering each pixel and colours the pixel according to the number of transmitters. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the number of servers is greater than or equal to a defined minimum threshold.
9.2.2.8 Scrambling Code Interference Analysis This coverage prediction calculates and displays the pixels covered by two cells using the same scrambling code. Atoll calculates the Received Signal Code Power (RSCP) for the P-CCPCH for each pixel in the TX i ic coverage area where TX ic i
RSCP P – CCPCH TAdd P – CCPCH Mobility and determines the interfering transmitters according to: TX i ic TX j jc RSCP P – CCPCH Best RSCP P – CCPCH – M ji
Where M is the specified pollution margin. The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for TS0. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest PCCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the RSCP considering: • • •
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
Atoll determines whether the cells of two transmitters covering a pixel have the same scrambling code. If the pixel is interfered, Atoll colours it according to the colour assigned to the scrambling code in the display parameters. Coverage
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consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as scrambling codes. Each layer corresponds to the area where the corresponding scrambling code has interference. A layer corresponding to areas where more than one scrambling code interferes is also available.
9.3 Monte Carlo Simulations The simulation process is divided into two steps. •
Generating a realistic user distribution as explained in "Generating a Realistic User Distribution" on page 608. Atoll generates user distributions as part of the Monte Carlo algorithm based on traffic data. The resulting user distribution complies with the traffic database and maps selected when creating simulations.
•
Dynamic channel allocation and power control as explained under "Power Control Simulation" on page 613.
9.3.1 Generating a Realistic User Distribution During each simulation, Atoll performs two random trials. The first random trial generates the number of users and their activity status as explained in the following sections depending on the type of traffic input. • •
"Simulations Based on User Profile Traffic Maps" on page 608. "Simulations Based on Sector Traffic Maps" on page 612. Atoll determines the total number of users attempting connection in each simulation based on the Poisson distribution. This may lead to slight variations in the total numbers of users in different simulations. To have the same total number of users in each simulation of a group, add the following lines in the Atoll.ini file: [Simulation] RandomTotalUsers=0
Each user is randomly assigned a service, a terminal, and a mobility type. The activity status is determined based on the calculations of activity probabilities using the traffic inputs. The user activity status influences the next step of the simulation, i.e., the interference in the network. Both active and inactive users use radio resources and generate interference. Once all the user characteristics have been determined, a second random trial is performed to obtain their geographical locations weighted according to the clutter classes, and whether they are indoor or outdoor according to the percentage of indoor users per clutter class defined for the traffic maps. Atoll also calculates the shadowing margin for each user based on the standard deviations defined for the clutter class of each user. In TD-SCDMA networks users accessing packet-switched services can transmit either on uplink or on downlink, but never on both simultaneously. Users accessing circuit-switched services transmit on both uplink and downlink simultaneously. Circuitswitched service users, mobiles connected in uplink and downlink both, are modelled in Atoll by two mobiles generated at the same location with one connected on the uplink and the other on the downlink. If one of these two mobiles is rejected for some reason, the other is also rejected due to the same reason.
9.3.1.1 Simulations Based on User Profile Traffic Maps User profile environment based traffic maps: Each pixel of the map is assigned an environment class which contains a list of user profiles with an associated mobility type and a given density, i.e., number of users of a user profile per km². User profile traffic maps: Each polygon or line of the map is assigned a density of users with a given user profile and mobility type. If the map is composed of points, each point is assigned a number of users with given user profile and mobility type. The user profile models the behaviour of the different user categories. Each user profile contains a list of services and their associated parameters describing how these services are accessed by the user. The number of users of each user profile is calculated from the surface area (SEnv) of each environment class map (or each polygon) and the user profile density (DUP). N Users = S Env D UP
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•
In case of user profile traffic maps composed of lines, the number of users per user profile is calculated from the line length (L) and the user profile density (DUP) (users per km): N Users = L D UP
•
The number of users is an input when a user profile traffic map is composed of points.
At any given instant, Atoll calculates the probability for a user being active in the uplink and in the downlink according to the service usage characteristics described in the user profiles, i.e., the number of voice calls or data sessions, the average duration of each voice call, or the volumes of the data exchanged in the uplink and the downlink in each data session.
9.3.1.1.1
Circuit Switched Service (i) User profile parameters for circuit switched services are: • •
The user terminal equipment used for the service (from the Terminals table), The average number of calls per hour N Call ,
•
The average duration of a call (seconds) D Call .
The number of users and their distribution per activity status is determined as follows: •
Calculation of the service usage duration per hour ( p 0 : probability of a connection):
N call d p o = ------------------3600 •
Calculation of the number of users trying to access the service i ( n i ):
n i = N Users p 0 The activity status of each user depends on the activity periods during the connection, i.e., the uplink and downlink activity UL
DL
factors defined for the circuit switched service i, f Act and f Act . •
Calculation of activity probabilities: UL
DL
Probability of being inactive: p Inactive = 1 – f Act 1 – f Act UL
UL
DL
DL
DL
UL
Probability of being active on UL: p Active = f Act 1 – f Act Probability of being active on DL: p Active = f Act 1 – f Act UL + DL
UL
DL
Probability of being active both on UL and DL: p Active = f Act f Act •
Calculation of number of users per activity status: Number of inactive users: n i – Inactive = n i p Inactive UL
UL
Number of users active in the uplink: n i – Active = n i p Active DL
DL
Number of users active in the downlink: n i – Active = n i p Active UL + DL
UL + DL
Number of users active in the uplink and downlink both: n i – Active = n i p Active
Therefore, a connected user can be either active on both links, inactive on both links, active on UL only, or active on DL only.
9.3.1.1.2
Packet Switched Service (j) User profile parameters for packet switched services are: • •
The user terminal equipment used for the service (from the Terminals table), The average number of packet sessions per hour N Sess ,
•
The volume (in kBytes) which is transferred on the downlink V
DL
and the uplink V
UL
during a session.
A packet session consists of several packet calls separated by a reading time. Each packet call is defined by its size and may be divided in packets of fixed size (1500 Bytes) separated by an inter-packet arrival time.
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Figure 9.1: Description of a Packet Session Calculation of the average packet call size (kBytes): UL
DL
UL DL V V S PacketCall = -------------------------------------- and S PacketCall = --------------------------------------UL UL DL DL N PacketCall f Eff N PacketCall f Eff UL
DL
In case of HSDPA services, f Eff and f Eff are the uplink and downlink A-DPCH activity factors, respectively. Calculation of the average number of packets per packet call: UL
DL
S PacketCall S PacketCall UL - + 1 and N DL - + 1 N Packet = Int ------------------------------Packet = Int ------------------------------UL S Packet 1024 S DL Packet 1024 1 kBytes = 1024 Bytes.
Calculation of the average duration of inactivity within a packet call (c): UL
UL
DL
DL
N Packet – 1 T Packet N Packet – 1 T Packet UL DL - and D Inactivity PacketCall = -------------------------------------------------------- D Inactivity PacketCall = --------------------------------------------------------1000 1000 Calculation of the average duration of inactivity in a session (s): UL
UL
UL
DL
DL
DL
D Inactivity Session = N PacketCall D Inactivity PacketCall and D Inactivity Session = N PacketCall D Inactivity PacketCall Calculation of the average duration of activity in a session (s): UL
UL
DL
DL
N Packet S Packet 8 UL UL - and D Activity Session = N PacketCall -----------------------------------------------UL R Nom 1000 N Packet S Packet 8 DL DL D Activity Session = N PacketCall -----------------------------------------------DL R Nom 1000 Therefore, the average duration of a connection in the session s is: UL
UL
UL
DL
DL
DL
D Connection = D Activity Session + D Inactivity Session and D Connection = D Activity Session + D Inactivity Session Calculation of the service usage duration per hour (probability of a connection): N Sess N Sess UL UL DL DL p Connection = ------------ D Connection and p Connection = ------------ D Connection 3600 3600 Calculation of the probability of being connected:
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DL
p Connected = 1 – 1 – p Connection 1 – p Connection Therefore, the number of users trying to access the service j is: n j = N Users p Connected As Figure 9.1 on page 610 shows, there can be three possible cases when a user is connected: a. 1st case: At a given time, packets are downloaded and uploaded. UL
DL
p Connection p Connection UL + DL The probability of being connected is: p Connected = --------------------------------------------------------p Connected b. 2nd case: At a given time, packet are uploaded only. UL
DL
p Connection 1 – p Connection UL The probability of being connected is: p Connected = ----------------------------------------------------------------------p Connected c. 3rd case: At a given time, packet are downloaded only. DL
UL
p Connection 1 – p Connection DL The probability of being connected is: p Connected = ----------------------------------------------------------------------p Connected Calculation of the probability of being active: To determine the activity status of each user, the activity periods during the connection are taken into account. f
UL
UL
DL
D Activity Session D Activity Session DL = --------------------------------------------------------------------------------------- and f = --------------------------------------------------------------------------------------UL UL DL DL D Inactivity Session + D Activity Session D Inactivity Session + D Activity Session
Therefore, we have: a. 1st case: At a given time, packets are downloaded and uploaded. DL
UL + DL
UL
UL + DL
UL
UL
1 – f p Connected
DL
DL
1 – f p Connected
DL
p Connected
The probability of the user being active on UL and inactive on DL: p1 Active = f The probability of the user being active on DL and inactive on UL: p1 Active = f UL + DL
The probability of the user being active on both UL and DL: p1 Active = f
UL
f
UL + DL
UL
DL
UL + DL
The probability of the user being inactive on both UL and DL: p1 Inactive = 1 – f 1 – f p Connected b. 2nd case: At a given time, packet are uploaded only. UL
The probability of the user being active on UL and inactive on DL: p2 Active = f
UL
UL
p Connected UL
UL
The probability of the user being inactive on both UL and DL: p2 Inactive = 1 – f p Connected c. 3rd case: At a given time, packet are downloaded only. DL
The probability of the user being active on DL and inactive on UL: p1 Active = f
DL
DL
p Connected
DL
DL
The probability of the user being inactive on both UL and DL: p3 Inactive = 1 – f p Connected Calculation of number of users per activity status: Number of inactive users on UL and DL: n j – Inactive = n j p1 Inactive + p2 Inactive + p3 Inactive UL
UL
UL
DL
DL
DL
Number of users active on UL and inactive on DL: n j – Active = n j p1 Active + p2 Active Number of users active on DL and inactive on UL: n j – Active = n j p1 Active + p3 Active UL + DL
UL + DL
Number of users active on UL and DL: n j – Active = n j p1 Active Therefore, a connected user can be active on both links, inactive on both links, active on UL only, or active on DL only.
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The user distribution per service, and the activity status distribution between the users are average distributions. The service and the activity status of each user are random in each simulation. Therefore, if you compute several simulations at once, the average number of users per service and average numbers of inactive, active on UL, active on DL, and active on UL and DL users, will correspond to calculated distributions. But, if you compare each simulation, you will observe that the user distribution between services as well as the activity status distribution between users is different in each simulation.
9.3.1.2 Simulations Based on Sector Traffic Maps Sector traffic maps are also referred to as live traffic maps. Live traffic data from the OMC is spread over the best server coverage areas of the transmitters included in the traffic map. Throughput demands per service, the numbers of active users per service, or Erlangs per service are assigned to the coverage areas of each transmitter.
9.3.1.2.1
Throughputs in Uplink and Downlink When selecting Throughputs in Uplink and Downlink, you can input the throughput demands in the uplink and downlink for each sector and for each listed service. Atoll calculates the number of users active in uplink and in downlink in the Txi cell using the service (NUL and NDL) as follows: N
UL
N
DL
UL
DL
RS RS DL = ----------- and N = ----------- for R99 circuit and packet switched services UL DL R Nom R Nom DL
RS = ---------for HSDPA service DL R Avg
UL
DL
R S and R S are the uplink and downlink throughputs for service S in the TXi cell from the traffic map. NUL and NDL values include: UL
•
Users active in uplink and inactive in downlink ( n i – Active ),
•
Users active in downlink and inactive in uplink ( n i – Active ),
•
And users active in both links ( n i – Active ).
DL
UL + DL
Atoll takes into account activity periods during the connection in order to determine the activity status of each user. Activity probabilities are calculated as follows: UL
DL
Probability of being inactive in UL and DL: p Inactive = 1 – f Act 1 – f Act UL
UL
DL
DL
DL
UL
Probability of being active in UL only: p Active = f Act 1 – f Act Probability of being active in DL only: p Active = f Act 1 – f Act UL + DL
UL
DL
Probability of being active both in UL and DL: p Active = f Act f Act UL
DL
Where, f Act and f Act are respectively the UL and DL activity factors defined for the service i. Then, Atoll calculates the number of users per activity status: We have: UL
UL + DL
UL
DL
UL + DL
DL
UL + DL
UL
DL
UL + DL
p Active + p Active n i – Active + n i – Active + n i – Active = N UL p Active + p Active n i – Active + n i – Active + n i – Active = N DL Therefore, we have: UL + DL
UL + DL
N UL p Active N DL p Active UL + DL --------------------------------------Number of users active in UL and DL both: n i – Active = min -------------------------------------- UL UL + DL DL + DL p Active + p Active p Active + p UL Active UL
UL + DL
Number of users active in UL and inactive in DL: n i – Active = N UL – n i – Active
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UL + DL
DL
Number of users active in DL and inactive in UL: n i – Active = N DL – n i – Active UL
UL + DL
DL
n i – Active + n i – Active + n i – Active Number of inactive users in UL and DL: n i – Inactive = -------------------------------------------------------------------------------- p inactive 1 – p inactive Therefore, a connected user can have four different activity status: either active in both links, or inactive in both links, or active in UL only, or active in DL only.
9.3.1.2.2
Total Number of Users (All Activity Statuses) When selecting Total Number of Users (All Activity Statuses), you can input the number of connected users for each sector and for each listed service ( n i ). Atoll takes into account activity periods during the connection in order to determine the activity status of each user. Activity probabilities are calculated as follows: UL
DL
Probability of being inactive in UL and DL: p Inactive = 1 – f Act 1 – f Act UL
UL
DL
DL
DL
UL
Probability of being active in UL only: p Active = f Act 1 – f Act Probability of being active in DL only: p Active = f Act 1 – f Act UL + DL
UL
DL
Probability of being active both in UL and DL: p Active = f Act f Act UL
DL
Where, f Act and f Act are respectively the UL and DL activity factors defined for the service i. Then, Atoll calculates the number of users per activity status: Number of inactive users in UL and DL: n i – Inactive = n i p Inactive UL
UL
DL
DL
Number of users active in UL and inactive in DL: n i – Active = n i p Active Number of users active in DL and inactive in UL: n i – Active = n i p Active UL + DL
UL + DL
Number of users active in UL and DL both: n i – Active = n i p Active
Therefore, a connected user can have four different activity status: either active in both links, or inactive in both links, or active in UL only, or active in DL only.
9.3.1.2.3
Number of Users per Activity Status When selecting Number of Users per Activity Status, you can directly input the number of inactive users ( n i – Inactive ), the UL
DL
UL + DL
number of users active in the uplink ( n i – Active ), in the downlink ( n i – Active ) and in the uplink and downlink ( n i – Active ), for each sector and for each service. The activity status of users is based on an average distribution. The activity status of each user is random in each simulation. Therefore, if you compute several simulations at once, the average numbers of inactive, active on UL, active on DL, and active on UL and DL users, will correspond to calculated distributions. But, if you compare each simulation, you will observe that the activity status distribution between users is different in each simulation.
9.3.2 Power Control Simulation Based on CDMA air interface, a TD-SCDMA network automatically regulates itself by using uplink and downlink power control in order to minimise interference and maximise capacity. For each user distribution, Atoll simulates these network regulation mechanisms using an iterative algorithm and calculates network parameters such as traffic power per cell and per timeslot, mobile terminal power, and handoff status for each terminal. In each iteration, all the mobiles (R99 and HSDPA service users) selected during generation of the user distribution attempt to connect to the network one by one. The process is repeated from iteration to iteration and ends when the network is balanced, i.e., when the convergence criteria on uplink and downlink are satisfied. The simulation algorithm also models the impact of smart antennas in the power control loop. The influence of smart antennas is taken into account in signal quality calculations. Smart antennas improve the signal quality of each served mobile,
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decrease the required powers and the loads of all the surrounding cells. Interference on the downlink and the uplink is calculated on a per user. Power control is simulated over a sub-frame, i.e., 7 timeslots. For HSDPA users, uplink and downlink power control is performed on the associated A-DCH bearer before fast link adaptation on downlink. The steps of this algorithm are detailed below.
Figure 9.2: TD-SCDMA Power Control Algorithm
9.3.2.1 Algorithm Initialisation At the start of each simulation, the system loads for each carrier and timeslot are reset to initial values: • •
Downlink traffic powers of cells P TCH – DL are initialised to 0 Watts Uplink interference powers received on all the carriers and timeslots I Intra – UL and I Extra – UL are initialised to 0 Watts (i.e., no connected mobiles)
•
Term
Uplink required power for mobiles is set to P Min
9.3.2.2 R99 Part of the Algorithm Req
The algorithm is described for an iteration k. Here, Xk is the value of the variable X at the iteration k. In the algorithm, all Q UL Req
and Q DL thresholds depend on the user mobility, and are defined in the Service and Mobility parameter tables. All the variables used in the description below are listed in "Definitions and Formulas" on page 595. The following calculations are made for all R99 and HSDPA mobiles (Mi) using R99 bearers.
9.3.2.2.1
Determination of Mi’s Best Server (SBS(Mi)) This step is performed for TS0 for each station TXi containing Mi in its calculation area. The best server for Mi is determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the P-CCPCH RSCP is calculated for: •
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• •
the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
The RSCP from a transmitter TXi and a selected carrier ic is given by: TX ic i
TX ic i
RSCP P – CCPCH = P P – CCPCH + G
TX
i
–L
TX
i
Model
M
i
– L Path – M Shadowing – L Body – L Indoor + G
M
i
–L
M
i
in dBm
Where, TX i
L Path = L Model + L Ant L Model is the loss on the transmitter-receiver path (path loss) calculated by the propagation model TX i
L Ant is the transmitter antenna attenuation (from antenna patterns) Model
M Shadowing is the shadowing margin. This parameter is taken into account when the option “Shadowing taken into account” is selected L Indoor are the indoor losses, taken into account when the option "Indoor coverage" is selected L
Mi
is the los of the terminal used by Mi
Mi
L Body is the body loss defined in the service used by Mi G G L
Mi TX i
TX i
is the receiver gain of the terminal user by Mi is the transmitter antenna gain is the transmitter loss ( L
TX i
= L Total – DL )
A cell TX i ic is considered the best server of a mobile Mi if it satisfies the following conditions: TX i ic
Min
RSCP P – CCPCH RSCP P – CCPCH , TX i ic
RSCP P – CCPCH TAdd P – CCPCH Mobility , TX i ic
And RSCP P – CCPCH =
Best RSCP TXj jc . P – CCPCH j = All
The best server is determined once for the whole simulation during the first iteration, i.e., k = 0, because the best server does not change during the simulation and smart antennas do not influence this step. Mi is considered unable to connect to the network if no best server has been selected. In this case, Mi is rejected for the reason P-CCPCH RSCP < Min P-CCPCH RSCP. If Mi has no best server, it is not taken into account in the next steps.
9.3.2.2.2
Dynamic Channel Allocation The dynamic channel allocation is performed once for the whole simulation during the first iteration, i.e., k = 0. The DCA controls the mobile admission. Once a mobile has been admitted for a simulation, it remains admitted for the all the iterations unless there are other reasons to reject it (following steps). The aim of Dynamic Channel Allocation (DCA) is to reduce interference in order to maximise the usage of the radio resources. In other words, the DCA tries to find the "best carrier" and the "best timeslots", which when allocated to the mobiles will optimise the load balance between carriers. If a preferred carrier is defined for the service requested by Mi and if it is available at TX i . BestCarrier TX i M i =
the
carrier preferred for the service. In the case of N-frequency compatible transmitters, Mi can be allocated timeslots over more than one slave carrier. Mi is considered unable to connect to the network if no carrier or not enough timeslots have been selected. In this case, the mobile Mi will be rejected for the reason "RU Saturation". If the carrier and timeslot(s) selected by the DCA do not satisfy the control of radio resource limits for DL power or UL load, then the mobile will be rejected for the reason "DL Load Saturation" or "Admission Rejection" respectively.
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There are four strategies for the DCA available in Atoll. These strategies are described below one by one. 1. Load Carrier Selection by Load: The DCA determines the least loaded carrier with enough timeslots to accomodate the service being used by each mobile Mi. The best carrier for a mobile is the one that is least loaded: BestCarrier TX i M i = Carrier
Where, X
DCA
DCA
= X DL
Min X
DCA
TX i ic TS M i
= N Tot – DL
if the mobile is connected in the downlink.
TX i ic TS M i
And, X
X
DCA
X
DCA
DCA
=
DCA X UL
N Tot – UL - X DCA if the mobile is connected in the uplink. = ----------------------------------------------TX i ic TS M i TX i N Tot – UL + N0
is the load increment given by: Mi
TX i
1 – f UL 1 – f JD = ---------------------------------------------------------------------1 1 + ----------Req Q UL Ortho
E b --- N t UL Proc = ------------------ is the uplink required signal quality. The uplink processing gain G UL calculated Proc G UL Req
Req
C Req Where Q UL = --- I UL
from the service parameters, if no smart antenna is used by the transmitter in the uplink. If a smart antenna is used by the transmitter in the uplink, the smart antenna gain is taken into account in calculating Req
Q UL . TX i ic TS M i
•
N Tot – UL
•
N Tot – DL
•
The carrier is the same in the uplink and in the downlink for mobiles accessing circuitswitched services.
TX i ic TS M i
is described in "Uplink Power Control" on page 617. is described in "Downlink Power Control" on page 619.
Timeslot selection by Load: From the selected carrier, Atoll selects the timeslots which are the least loaded and have enough resource units for the service being accessed by Mi. 2. Available RUs Carrier selection by Available RUs: The DCA determines the carrier which has the highest number of available resource units with enough timeslots to accomodate the service being used by each mobile Mi. The best carrier for a mobile is the one that has the highest number of resource units: BestCarrier TX i M i = Carrier
Max RUs
Timeslot selection by Available RUs: From the selected carrier, Atoll selects the timeslots which have the highest numbers of available resource units. 3. Direction of Arrival Carrier selection by Direction of Arrival: The DCA determines the direction of arrival of the signal from the served user Mi and checks whether there is an interfering mobile in the same direction as Mi. Atoll searches for interfering mobiles within the angle defined by the Angular Step. For example, if you enter an angular step of 15 degrees, Atoll searches for interfering mobiles within 15 degrees to the right and to the left of the served user, and allocates a different carrier than the ones used by any interfering mobiles found. The best carrier for a mobile is the one which is not interfered by another mobile in the direction of the mobile Mi. BestCarrier TX i M i = Carrier
DoA Mi DoA Mj
In other words, the direction of arrival for the served user Mi should not be the direction of arrival of an interfering mobile.
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Timeslot selection by Direction of Arrival: From the selected carrier, Atoll selects the timeslots which are not being used by any other mobile Mj located in the same direction as the served user Mi. 4. Sequential Sequential carrier selection: The DCA allocates carriers to served users Mi in a sequential order. Sequential timeslot selection: From the selected carrier, Atoll allocates timeslots to served users Mi in a sequential order. At the end of the DCA, each admitted mobile has an associated carrier and timeslots. In case of N-frequency mode compatible transmitters, an admitted mobile can have associated timeslots over more than one slave carrier.
9.3.2.2.3
Uplink Power Control For each mobile Mi, the uplink power control step calculates the uplink power required to satisfy the required quality level on the traffic channel, which is defined for the service being accessed by Mi. If the mobile Mi is connected (active or inactive) in the uplink and has a best server TX i ic assigned to it, Atoll calculates the signal quality on the uplink timeslots allocated to Mi by the DCA: TX i ic TS M i
E b --- N t TCH – UL
TX i ic TS M i
Mi
Mi
TX i ic TS M i
TX i ic TS M i RSCP TCH – UL RSCP TCH – UL Div C - G Proc - G Div = ------------------------------------------------------= ------------------------------------------------------UL G UL or --- UL TX i ic TS M i TX i ic TS M i I TCH – UL N Tot – UL N Tot – UL
Calculation of Uplink Total Noise ( N Tot – UL ): The uplink total noise is calculated for the uplink connection between each mobile Mi and its best server TX i ic . TX i ic TS M i
N Tot – UL
TX i ic TS M i
= I Tot – UL
TX i
+ N0
Where
TX i ic TS M i
I Tot – UL
Mi
=
RSCP TCH – UL TX i ic TS M i
Mj
Mi
+
RSCP TCH – UL TX i ic TS M i
Mi
+
M j TX i ic TS M i Mj Mi
M
M
1 – j RSCP j TCH – UL TX i ic TS M i +
M j TX i ic TS M i Mj Mi
M
TX
j i RSCP TCH – UL TX i ic TS M i 1 – F MCJD
M TX ic TS M j i i
M
i
=
M
i
Ortho
1 – F UL
TX i 1 – F JD and = 0 1
Without Useful Signal Total Noise
The above formula gives the value of I Tot – UL for the uplink connection between Mi and TX i ic , taking into account the interference received from other mobiles, Mj, which are located in the Mi best server coverage area, as well as located in the coverage areas of other cells. The mobile Mi is the focus, i.e., the mobile that is listened to by the transmitter TX i ic .
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The four terms comprising I Tot – UL are: •
The useful signal for which the received mobile is the focus (Mi).
•
The intra-cell interference for which the best-server is the same for the received mobile Mj and the focus Mi, TX i ic .
•
The intra-cell interference due to distortion in the terminal transmission.
•
The extra-cell interference for which the best-server for the received mobile Mj is not TX i ic . Mi
P Req TX i ic TS M i k–1 The uplink received signal code power is: RSCP TCH – UL TX i ic TS M i = --------------------------------------------------------------Model LT Mi
TX i
Mi
Mi
Model
Mi L Path L L L Body L Indoor M Shadowing = ------------------------------------------------------------------------------------------------------------------ and P Req TX i ic TS M i is the uplink required mobile power TX i Mi G G
Model LT
Mi
Mi
calculated for the timeslot allocated to Mi. If Mi is an HSDPA user, P Req TX i ic TS M i = 0.1 PReq TX i ic TS M i Model
In L T
, G
TX i
SA
= G UL and L
TX i
SA
= L UL are calculated according to the smart antenna modelling method used, for
Mi
P Req TX i ic TS M i , if a smart antenna is available in the uplink. Otherwise, G
TX i
and L
TX i
are read from the main antenna
model. Interference is updated only for active mobiles on the uplink for circuit- and packetswitched services. However, if these mobiles are rejected, they are considered in the number of rejected mobiles. Mi
Calculation of Uplink Required Power ( P Req ): Then Atoll determines the required uplink power by: Req
Mi
P Req TX i ic TS M i
E b --- N t TCH – UL = P Req TX i ic TS M i -------------------------------------k–1 E b TXi ic TS M i --- N t TCH – UL Mi
k
Req
Mi
or P Req TX i ic TS M i
M
C --- I TCH – UL -----------------------------------= P Req TX i ic TS M i TX i ic TS M i k–1 C --- I TCH – UL Mi
k
M
i
i
M
M
i
i
And if P Req TX i ic TS M i P Min then P Req TX i ic TS M i = P Min M
M
i
i
If P Req TX i ic TS M i P Max
then the mobile Mi is rejected for the reason "Pmob > PmobMax", and
Mi
P Req TX i ic TS M i is set to 0. Mi
Mi
P Min and P Max are set in the properties of the terminal used by the mobile Mi. TX i ic TS M i
Where RSCP TCH – UL
TX i
Mi
P Req TX i ic TS M i k–1 = --------------------------------------------------------------Model LT Mi
Mi
Model
Mi L Path L L L Body L Indoor M Shadowing = ------------------------------------------------------------------------------------------------------------------ and P Req TX i ic TS M i TX i Mi G G power for iteration k - 1 transmitted on the timeslot allocated to Mi. Model LT
618
k–1
is the uplink required mobile
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AT330_TRR_E1
Model
In L T M
, G
TX
i
SA
= G UL and L
TX
i
SA
= L UL are calculated according to the smart antenna modelling method used, for
i
P Req TX i ic TS M i , if a smart antenna is available in the uplink. Otherwise, G
TX
i
and L
TX
i
are read from the main antenna
model. The uplink required powers for mobiles inactive in the uplink accessing circuit- or packetswitched services are calculated for information only. However, if these mobiles are rejected, they are considered in the number of rejected mobiles.
9.3.2.2.4
Downlink Power Control For each mobile Mi, the downlink power control step calculates the downlink power for the best server TX i ic required to satisfy the required quality level on the traffic channel, which is defined for the service being accessed by Mi. If the mobile Mi is connected (active or inactive) in the downlink and has a best server TX i ic assigned to it, Atoll calculates the signal quality on the uplink timeslots allocated to Mi by the DCA: TX i ic TS M i
E b --- N t TCH – DL
TX i ic TS M i
TX i
TX i
TX i ic TS M i
TX i ic TS M i RSCP TCH – DL RSCP TCH – DL Div C - G Proc -- G Div = ------------------------------------------------------- G or = -------------------------------------------------------DL DL DL TX i ic TS M i TX i ic TS M i I TCH – DL N Tot – DL N Tot – DL
Calculation of Downlink Total Noise ( N Tot – DL ): The downlink total noise is calculated for the downlink connection between each mobile Mi and its best server TX i ic . TX i ic TS M i
N Tot – DL
TX i ic TS M i
= I Tot – DL
Mi
+ I IC – DL ic jc + I MM M i M j + N 0
Where
TX i ic TS M i
I Tot – DL
TX i ic TS M i
=
RSCP Tot – DL
Mi
TX i
+
TX i ic TS M i
RSCP Tot – DL
1 – i RSCP i Tot – DL
Mj
TX i
+
M TX ic TS M j i i Mj Mi TX
TX ic TS M i
Mj +
M j TX i ic TS M i Mj Mi
TX j ic TS M i
RSCP Tot – DL
Mj
M j TX i ic TS M i
The four terms comprising I Tot – DL are: •
The useful signal for which the received mobile is the focus (Mi).
•
The intra-cell interference for which the best-server is the same for the received mobile Mj and the focus Mi, TX i ic .
•
The intra-cell interference due to distortion in the transmitter.
•
The extra-cell interference for which the best-server for the received mobile Mj is not TX i ic . TX j jc TS M i
RSCPTot – DL
Mi
All TX
j I IC – DL ic jc = ---------------------------------------------------------------F IRF ic jc
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TX
i
=
TX
i
Ortho
1 – F DL
©Forsk 2015
M i 1 – F JD and = 0 1
Without Useful Signal Total Noise
I IC – DL ic jc is the inter-carrier interference from a carrier jc to another carrier ic on the downlink, which is reduced by the interference reduction factor F IRF ic jc defined for the pair (ic, jc). TX i ic TS M i
TX i ic TS M i
= RSCP TCH – DL
RSCP Tot – DL
TX i ic TS M i
With RSCP TCH – DL
Model
TX ic TS M
i i P TCH – DL TX i ic TS M i P OCCH k–1 = ----------------------------------------- and RSCP OCCH = -----------------------------Model Model LT LT
TX i ic TS M i
LT
TX i ic TS M i
+ RSCP OCCH
TX i
Mi
Mi
Model
TX i ic TS M i L Path L L L Body L Indoor M Shadowing = ------------------------------------------------------------------------------------------------------------------ and P TCH – DL TX i Mi G G
is the downlink traffic power transmitted
k–1
TX ic TS M i i
on the timeslot allocated to Mi during the iteration k - 1. If Mi is an HSDPA user, P TCH – DL Model
In L T
, G
TX i ic TS M i
P TCH – DL
TX i
SA
= G DL and L
TX i
TX ic TS M i i
= 0.1 P TCH – DL
SA
= L DL are calculated according to the smart antenna modelling method used, for
TX i ic TS M i
only and not for P OCCH
, if a smart antenna is available in the downlink. Otherwise, G
TX i
and L
TX i
are
read from the main antenna model. Mj
RSCPTCH – UL Mi M
j I MM M i M j = ------------------------------------------------is the interference from each mobile Mj transmitting in the uplink on the same F IRF ic jc
timeslots as those on which the mobile Mi is receiving in the downlink. Mj can interfere Mi directly if and only if: Mi – Mj
•
The distance between Mi and Mj ( d ) is less than the Max Distance between interfering mobiles defined by the user when starting the simulation, and The downlink timeslot of Mi (TSMi) is the same as the uplink timeslot of Mj, (TSMj).
•
The interference received from the mobile Mj at the mobile Mi is calculated using either the free-space propagation model or the Xia model. Mj
Mj P TCH – UL RSCP TCH – UL M i = ------------------L MM
L MM
32.4 + 20 Log F Avg + 20 Log d = 49 + 30 Log F Avg + 40 Log d
If d If d
Mi – Mj
Mi – Mj
3m
with F Avg being the average frequency in MHz of the
3m
frequency band used by the best server of the mobile Mi, and d is the distance between the mobiles Mi and Mj in km. TX i ic TS M i
Calculation of Downlink Required Power ( P Req
):
Then Atoll determines the required downlink power by: Req
TX i ic TS M i
P Req
TX i ic TS M i
k
= P Req
E b --- N t TCH – DL -------------------------------------k–1 E b TXi ic TS Mi --- N t TCH – DL Req
TX i ic TS M i
or P Req
TX i ic TS M i
k
= P Req
TX i ic TS M i
And if P Req
620
Min
C --- I TCH – DL -----------------------------------TX i ic TS M i k–1 C --- I TCH – DL TX i ic TS M i
P TCH – DL Service then P Req
Min
= P TCH – DL Service
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AT330_TRR_E1 TX ic TS M i i
If P Req
TX ic TS M i i
Max
P TCH – DL Service then the mobile Mi is rejected for the reason "Ptch > PtchMax", and P Req
is set
to 0. Min
Max
P TCH – DL Service and P TCH – DL Service are set in the properties of the R99 bearer associated with the service used by the mobile Mi. TX i ic TS M i
Otherwise, the downlink traffic power is incremented P TCH – DL
TX i ic TS M i
= P TCH – DL
TX i ic TS M i
+ P Req
For each mobile, Atoll also calculates the downlink traffic power for the different values of the Angular Step Step . TX i ic TS M i
RSCP TCH – DL
TX i ic TS M i
Step
= RSCP TCH – DL
TX i ic TS M i
Where RSCP TCH – DL
TX i
SA
G DL -----------------------SA L DL Step
TX i ic TS M i
P Req k–1 = ----------------------------------------Model LT Mi
Mi
Model
TX i ic TS M i L Path L L L Body L Indoor M Shadowing = ------------------------------------------------------------------------------------------------------------------ and P Req TX i Mi G G - 1 transmitted on the timeslot allocated to Mi. Model LT
Model
In L T
, G
TX i ic TS M i
P Req
TX i
SA
= G DL and L
TX i
k–1
is the downlink traffic power for iteration k
SA
= L DL are calculated according to the smart antenna modelling method used, for
, if a smart antenna is available in the downlink. Otherwise, G
TX i
and L
TX i
are read from the main antenna
model. The downlink power for mobiles inactive in the downlink accessing circuit- or packetswitched services are calculated for information only.
9.3.2.2.5
Uplink Signals Update This step uses the uplink terminal powers calculated for each timeslot allocated to the mobiles. The Dynamic Channel Allocation allocates timeslots and carriers to all the connected and active mobiles. The Dynamic Channel Allocation is performed once only, during the first iteration, and the timeslot and carrier allocation remains the same for all the following iterations of a simulation. This step updates the received signals for all the mobiles Mi interfered in the uplink by the uplink connection between interfering mobiles Mj and their best servers TX j ic , only if TX j ic contain Mi in their coverage areas. TX i ic is the interfered receiver and Mi is the focus, i.e., the mobile that is listened to by the transmitter TX i ic . TX i ic TS M i
For each mobile Mi interfered by Mj in the uplink by the connection between Mj and TX j ic , Atoll updates RSCP TCH – UL
9.3.2.2.6
.
Downlink Signals Update For the first iteration, i.e., k = 0, the downlink traffic powers for all the downlink timeslots are set to 0 Watts. Therefore, for the first iteration, this step is performed for any downlink timeslot for each mobile Mi that is connected and active. However, for the following iterations, the downlink signals update step uses the actual downlink traffic powers calculated for each timeslot and the actual timeslots allocated to the mobiles. The Dynamic Channel Allocation allocates timeslots and carriers to all the connected and active mobiles. The Dynamic Channel Allocation is performed once only during the first iteration and the timeslot and carrier allocation remains the same for all the following iterations of a simulation. Therefore, this step is performed for any downlink timeslot for each mobile Mi that is connected and active for the first iteration, and this step is performed for all the downlink timeslots allocated to the mobile Mi on which it is connected and active, for the following iterations since the DCA has been performed. This step updates the received signals for all the mobiles in the TX i ic coverage area which are interfered in the downlink by the connection between TX i ic and Mi. TX i ic TS M i
For each mobile interfered by Mi, Atoll updates RSCP TCH – DL
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Where TX i ic is the transmitter considered and Mi is the focus, i.e., the mobile that is the target for TX i ic .
9.3.2.2.7
Control of Radio Resource Limits (Downlink Traffic Power and Uplink Load) This step checks whether the downlink traffic powers of the downlink timeslots and the uplink loads of the uplink timeslots of all the cells satisfy the conditions defined globally or per cell and timeslot. Downlink Power Control: Atoll verifies that the total R99 power transmitted by any cell on any timeslot does not exceed the effective maximum cell power per timeslot. The effective maximum cell traffic power per timeslot is calculated as: TX i ic TS M i
TX i ic TS M i
P Max – DL – Eff = P Max – DL TX i ic TS M i
Where P Max – DL
%P Max – DL
is the maximum cell power per timeslot defined per cell, and %P Max – DL is the maximum allowed
downlink load either taken from the properties of each cell or from the simulation properties if a global value is defined. For each transmitter TXi, carrier ic, and downlink timeslot TS M , i
TX i ic TS M i
P R99 – DL
TX i ic TS M i
= P TCH – DL
TX i ic TS M i
If P R99 – DL
TX i ic TS M i
+ P OCCH
TX i ic TS M i
P Max – DL – Eff the mobile with the lowest service priority is rejected for the reason "DL Load Saturation".
Uplink Load Control: Atoll verifies that the uplink load of any cell on any timeslot does not exceed the maximum uplink cell load allowed per timeslot. TX i ic TS M i
The maximum allowed uplink cell load, X Max – UL
, is either taken from the properties of each cell or from the simulation
properties if a global value is defined. For each transmitter TXi, carrier ic, and uplink timeslot TS M , i
TX i ic TS M i
If X UL
TX i ic TS M i
X Max – UL
the mobile with the lowest service priority is rejected for the reason "UL Load Saturation".
The uplink load is given by: TX i ic TS M i
X UL
TX i ic TS M i
N Tot – UL = ----------------------------------------------- if no smart antenna is used by the transmitter in the uplink. TX i ic TS M i TX i N Tot – UL + N0
If a smart antenna is used by the transmitter in the uplink, the smart antenna gain is taken into account in the calculation of uplink load.
9.3.2.3 HSDPA Part of the Algorithm The following calculations are made for all HSDPA mobiles (Mi).
9.3.2.3.1
HSDPA Power Allocation TX i ic
The total transmitted power of the cell ( P Tot – DL ) is the sum of the R99 transmitted power and the HSDPA powers. TX i ic
TX i ic
TX i ic
P Tot – DL = P R99 – DL + P HR
TX i ic
TX i ic
+ P HS – SCCH + P HS – PDSCH
The HSDPA powers, i.e., the HS-SCCH and HS-PDSCH powers are calculated as follows: •
HS-SCCH Power: HS-SCCH channels are transmitted on DL traffic timeslots. The maximum number of supported HS-SCCH channels is defined per cell. Power can be allocated to HS-SCCH statically or dynamically: •
Static Allocation The static HS-SCCH power is defined in the properties of the HSDPA cell.
•
622
Dynamic Allocation
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TX ic TX ic E TXi ic Req i i HS-SCCH power is calculated for ----c- = Q HS – SCCH Mobility so that P HS – SCCH P Available – HS – SCCH . N t HS – SCCH TX ic i
TX ic i
TX ic i
TX ic i
Where P Available – HS – SCCH = P Max – DL – Eff – P R99 – DL – P HR TX i ic , and
TX ic i P R99 – DL
=
TX ic i P TCH – DL
+
TX ic i P OCCH
is the power available for HS-SCCH in the cell
. TX i ic
TX i ic
The effective maximum cell traffic power per timeslot is calculated as: P Max – DL – Eff = P Max – DL %P Max – DL . TX ic i
P Max – DL is the maximum power defined per cell, and %P Max – DL is the maximum allowed downlink load either taken from the properties of each cell or from the simulation properties if a global value is defined. TX ic i
TX i ic
P HS – SCCH
TX ic
TX ic
Ec i i i --- N – RSCP HS – SCCH N t HS – SCCH Tot – DL Model = ---------------------------------------------------------------------------------------------------------------------------- LT TX i TX
TX i ic
Where N Tot – DL is the downlink total noise calculated in "Downlink Power Control" on page 619,
TX i
=
TX i
Ortho
1 – F DL TX i
Mi 1 – F JD and = 0 1 Mi
Mi
Without Useful Signal Total Noise
Model
TX i ic L Path L L L Body L Indoor M Shadowing = ------------------------------------------------------------------------------------------------------------------ and P HS – SCCH is the HS-SCCH power calculated for the TX i Mi G G timeslots allocated to Mi. Model LT
Model
In L T
,G
TX
i
SA
= G DL and L
TX
i
SA
= L DL are calculated according to the smart antenna modelling method used, for
TX i ic
P HS – SCCH , if a smart antenna is available in the downlink. Otherwise, G
TX i
and L
TX i
are read from the main
antenna model. •
HS-PDSCH Power: HS-PDSCH channels are transmitted on DL traffic timeslots. Power can be allocated to HS-PDSCH statically or dynamically: •
Static Allocation The static HS-PDSCH power is defined in the properties of the HSDPA cell.
•
Dynamic Allocation HS-PDSCH power is calculated as follows: TX ic i
TX ic i
TX ic i
TX ic i
P HS – PDSCH = P Max – DL – Eff – P R99 – DL – P HR TX i ic
TX i ic
TX ic i
– P HS – SCCH
TX i ic
Where P R99 – DL = P TCH – DL + P OCCH . The effective maximum cell traffic power per timeslot is calculated as: TX i ic
TX i ic
TX i ic
P Max – DL – Eff = P Max – DL %P Max – DL . P Max – DL is the maximum power defined per cell, and %P Max – DL is the maximum allowed downlink load either taken from the properties of each cell or from the simulation properties if a global value is defined. The HS-SICH power is calculated as follows: •
HS-SICH Power: HS-SICH channels can be transmitted on any UL traffic timeslot. The maximum number of supported HS-SICH channels is defined per cell. Power can be allocated to HS-SICH statically or dynamically: •
Static Allocation The static HS-SICH power is defined in the properties of the terminal used by the HSDPA mobile Mi.
•
Dynamic Allocation
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M TX ic E TXi ic Req i i HS-SICH power is calculated for ----c- = Q HS – SICH Mobility so that P HS – SICH P Max – HS – SICH and N t HS – SICH M
M
i
i
P HS – SICH P Max – HS – SICH . TX ic i
Mi
P HS – SICH
TX ic i
Where
M
i
=
TX ic
Ec i i i --- N – RSCP HS – SICH N t HS – SICH Tot – UL - L Model = ------------------------------------------------------------------------------------------------------------------------T Mi N Tot – UL
M
i
M
M
is the uplink total noise calculated in "Uplink Power Control" on page 617, Ortho
1 – F UL
TX i
TX i 1 – F JD and = 0 1 Mi
Mi
Without Useful Signal Total Noise
Model
M L Path L L L Body L Indoor M Shadowing i = ------------------------------------------------------------------------------------------------------------------ and P HS – SICH is the HS-SICH power calculated for the TX i Mi G G timeslots allocated to Mi. Model
LT
Model
In L T
,G
TX i
SA
= G UL and L
TX i
SA
= L UL are calculated according to the smart antenna modelling method used,
Mi
for P HS – SICH , if a smart antenna is available in the uplink. Otherwise, G
TX i
and L
TX i
are read from the main
antenna model. TX i ic
The total transmitted power of the cell ( P Tot – DL ) is the sum of the R99 transmitted power and the HSDPA powers. TX i ic
TX i ic
TX i ic
P Tot – DL = P R99 – DL + P HR
9.3.2.3.2
TX i ic
TX i ic
+ P HS – SCCH + P HS – PDSCH
Connection Status and Number of HSDPA Users HSDPA users cannot receive HS-SCCH and HS-PDSCH powers simultaneously. HS-PDSCH arrives 3 timeslots after the HS-SCCH. HS-SICH is 9 timeslots after the HS-PDSCH. Atoll assumes that an active HSDPA user has the same probability of receiving HSSCCH and HS-PDSCH, and transmitting HS-SICH because their occurrence is equally likely. Therefore, each HSDPA user is assigned a sub-connection status randomly. The sub-connection status can be: • • •
HS-SCCH: HSDPA mobile that is receiving HS-SCCH power HS-PDSCH: HSDPA mobile that is receiving traffic power HS-SICH: HSDPA mobile that is transmitting HS-SICH power
The number of active HSDPA users belonging to each sub-connection status is 1/3rd of the total number of active HSDPA users. n HS – SCCH is the maximum number of HS-SCCH channels and n HS – SICH is the maximum number of HS-SICH channels that the cell can manage. Each HSDPA user consumes one HS-SCCH and HS-SICH channels. Therefore, at a given instance, the number of connected HSDPA users cannot exceed the number of HS-SCCH and HS-SICH channels per cell. The maximum number of HSDPA users ( n Max ) corresponds to the maximum number of HSDPA users that the cell can support.
9.3.2.3.3
HSDPA Admission Control HS-SCCH HS-SCCH admission control is performed for active HSDPA users connected to A-DCH bearers on the downlink and having an HS-SCCH sub-connection status. Each cell is able to manage a maximum number of HS-SCCH channels, n HS – SCCH . During the R99 part, the DCA provides a DL timeslot with one SF16 resource unit that has the downlink Ec/Nt higher than the required quality. If no cell with such a resource unit is available, the user is rejected. HS-SICH HS-SICH admission control is performed for active HSDPA users connected to A-DCH bearers on the uplink and having an HSSICH sub-connection status. Each cell is able to manage a maximum number of HS-SICH channels, n HS – SICH . During the R99 part, the DCA provides an UL timeslot with one SF16 resource unit that has the uplink Ec/Nt higher than the required quality. If no cell with such a resource unit is available, the user is rejected.
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HS-PDSCH Scheduling is performed for active HSDPA users connected to A-DCH bearers on the downlink and having an HS-PDSCH subconnection status. The scheduling is performed as follows: 1. Each HS-PDSCH user is considered as the only served user. The scheduler allocates the best available HSDPA bearer to each user. The best available HSDPA bearer is selected depending on the user’s Ec/Nt. If no bearer can be allocated due to low Ec/Nt, the user is rejected for the reason "HSDPA Scheduler Saturation". The required HS-PDSCH Ec/Nt value is read from receiver equipment properties. For each bearer, Atoll checks that the Ec/Nt reaches the quality target. HS-PDSCH Ec/Nt is calculated by taking into account all intra and extra cells interferences. 2. The scheduler sorts the HS-PDSCH users to whom bearers have been assigned in the order of decreasing RLC peak throughputs. If two users have the same bearer, the user with the higher Ec/Nt has the higher rank. 3. The scheduler considers the group of HS-PDSCH users to whom bearers, HS-SCCH, and HS-SICH have been assigned. The number of HS-PDSCH users cannot exceed the maximum number of HSDPA users ( n Max ) supported by the cell. If there are enough HSDPA power and resource units available in order to obtain a HSDPA bearer, the users will be connected. Otherwise, they will be delayed and their connection status will be “HSDPA Delayed”. 4. Other HS-PDSCH users will be rejected for the reason "HSDPA Scheduler Saturation". For N-frequency mode compatible transmitters, the resource units available in the master and slave carriers can be shared, i.e., a mobile can be connected to timeslots belonging more than one carrier.
9.3.2.3.4
HSDPA Dynamic Channel Allocation For each mobile connected to the A-DPCH bearer: 1. Atoll selects the HSDPA bearers that match to the mobile terminal and UE category parameters. 2. For each bearer supported by a mobile: a. The scheduler searches for the best collection of "n" ordered timeslots that can provide enough resource units to support the service, and whose Ec/Nt is better than the minimum required and enough to reach the bearer’s resource unit requirements. The best is determined by applying the R99 Dynamic Channel Allocation algorithm. b. The scheduler calculates the HS-PDSCH Ec/Nt for each timeslot of the best collection. The Ec/Nt value associated with the mobile-bearer pair is the worst one of all selected timeslots. c. If the scheduler is unable to find a satisfactory timeslot collection, the bearer is removed from the list of supported bearers. 3. The mobile is connected to the supported bearer having the highest RLC peak throughput. If two bearers have the same RLC peak throughput, the best one is the one with the highest Ec/Nt.
9.3.2.3.5
Ressource Unit Saturation For each time slot, a minimum and maximum number of resource units for HSDPA users are defined in the cell properties. Atoll dynamically allocates the required number of codes respecting these limitations. The minimum number of HSDPA codes is excluded from the set of codes available for R99 users. The scheduler checks if enough codes are available for the selected HSDPA bearer (taking into account the maximum number of HSDPA codes). If not, the scheduler allocates a lower HSDPA bearer which needs fewer codes. If there are no more resource units available for the lowest HSDPA bearer, the user will be delayed or rejected.
9.3.2.4 Convergence Criteria The convergence criteria are evaluated for each iteration and can be written as follows: Max TXi ic TS M i DL = Int P Err 100 All TX i
UL
TX i ic TS M i TX i ic TS M i – N Tot – UL Max N Tot – UL k k – 1 = Int ------------------------------------------------------------------------------------- 100 TX ic TS M All TX i i i N Tot – UL k TX ic TS M i i
Where, P Err
is given by:
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©Forsk 2015 TX ic TS M i i
TX ic TS M i i P Err
TX ic TS M i i
– P Rec P Rec Max k k–1 Step Step = ------------------------------------------------------------------------------------------------------------- with smart antennas. TX ic TS M 0 Step 360 i i P Rec
TX ic TS M i i P Err
TX ic TS M i i
Step
k
TX ic TS M i i
P Rec – P Rec k k – 1 without smart antennas. = ---------------------------------------------------------------------------------TX i ic TS M i P Rec k
Atoll stops the simulations in the following cases: •
Convergence: Between two successive iterations, DL and UL are less than or equal to their respective thresholds (defined when creating a simulation). Example: Let us assume that the maximum number of iterations is 100, and the UL and DL convergence thresholds are set to 5 %. If DL 5 and UL 5 between the 4th and the 5th iteration, Atoll stops the algorithm after the 5th iteration. The simulation has converged.
•
Divergence: After 30 iterations, DL and/or UL are still higher than their respective thresholds and from the 30th iteration, DL and/or UL do not decrease during the next 15 successive iterations. Examples: Let us assume that the maximum number of iterations is 100, and the UL and DL convergence thresholds are set to 5 %. a. After the 30th iteration, DL and/or DL equal 100 and do not decrease during the next 15 successive iterations. Atoll stops the algorithm at the 46th iteration. The simulation has not converged. b. After the 30th iteration, DL and/or UL equal 80, they start decreasing slowly until the 40th iteration (without going under the thresholds) and then, do not change during 15 successive iterations. Atoll stops the algorithm at the 56th iteration without converging.
•
Last Iteration: If DL and/or UL are still much higher than their respective thresholds after the last iteration, the simulation has not converged. If DL and UL are lower than their respective thresholds, the simulation has reached convergence.
9.4 TD-SCDMA Prediction Studies For each TBC transmitter, TXi, Atoll determines the value of the selected parameter on each studied pixel inside the TXi calculation area. Each pixel within the TXi calculation area is considered a probe receiver. Coverage study parameters to be set are: • •
The study conditions to determine the service area of each TBC transmitter The display settings to for colouring the covered pixels
Atoll uses the parameters entered in the Condition tab of the coverage study properties dialogue to determine pixels covered by the each transmitter. Coverage prediction display resolution is independent of the path loss matrix and geographic data resolutions, and can be different for each coverage prediction. Coverage predictions are calculated using bilinear interpolation of multi-resolution path loss matrices (similar to the evaluation of site altitudes).
9.4.1 P-CCPCH Reception Analysis (Eb/Nt) or (C/I) E C These coverage predictions calculate and display the Eb/Nt or C/I on the P-CCPCH, ----b- or --- . The N t P – CCPCH I P – CCPCH coverage predictions are calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for TS0. The best servers for the coverage predictions are determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage predictions are calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform these coverage predictions for the best carrier, Atoll calculates the Eb/Nt or C/I considering: • • •
626
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
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AT330_TRR_E1
The
pixels
in
TX i ic
the
TX ic i
coverage
area
where
TX ic i
Min
RSCP P – CCPCH Max (TAdd P – CCPCH,RSCP P – CCPCH) ,
and
TX ic i
E b Req Req ---C --- N t P – CCPCH Q P – CCPCH or I P – CCPCH Q P – CCPCH are covered and coloured according to the selected display option. TX
TX ic i
TX
TX ic
i i TX i ic E TX i ic RSCP P – CCPCH RSCP P – CCPCH Proc C --- G Where ----b- = ----------------------------------------------- and = -----------------------------------------------P – CCPCH TX i ic I P – CCPCH TX i ic N t P – CCPCH N Tot – DL N Tot – DL i
TX i ic
TX i ic P P – CCPCH RSCP P – CCPCH = ---------------------LT
The downlink total noise is calculated as follows: TX i ic
TX i ic
TX i ic
Term
N Tot – DL = I Intra – DL + I Extra – DL + I IC – DL ic jc + N 0 Where TX i ic
TX i ic
I Intra – DL = RSCP P – CCPCH With
TX i
=
TX ic i
I Extra – DL =
TX i
Ortho
1 – F DL
TX i
TX i ic
+ RSCP OCCH – TS0 Term
1 – F JD
TX ic j
TX i
and = 0 1
Without Useful Signal Total Noise
TX ic j
RSCPP – CCPCH + RSCPOCCH – TS0 ji
TX j jc
TX j jc
RSCPP – CCPCH + RSCPOCCH – TS0 TX
j I IC – DL ic jc = --------------------------------------------------------------------------------------F IRF ic jc
I IC – DL ic jc is the inter-carrier interference from a carrier jc to another carrier ic on the downlink, which is reduced by the interference reduction factor F IRF ic jc defined for the pair (ic, jc). TX i ic
TX i ic
RSCP OCCH – TS0
P OCCH – TS0 = -----------------------LT
TX i
Eb Nt
Term
L Path L L L Body L Indoor M Shadowing L T = ----------------------------------------------------------------------------------------------------------------------TX i Term G G
TX i
Term
and N 0
are defined in "Definitions and Formulas" on page 595.
Coverage Display It is possible to colour the transmitter service areas using a unique colour per transmitter, or colour the pixels in the coverage areas by any transmitter attribute or other criteria such as: •
Eb/Nt or C/I (dB) Atoll calculates the Eb/Nt or C/I on each pixel of the TX i ic best server coverage area. The pixel colour depends on the Eb/Nt or C/I level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For each layer, a TX ic
TX ic
Eb i C i Threshold or --- Threshold . Each layer is assigned a colour and pixel is covered if ----- N t P – CCPCH I P – CCPCH displayed with intersections between layers. •
Eb/Nt Margin or C/I Margin (dB) Atoll calculates the Eb/Nt or C/I margin on each pixel of the TX i ic best server coverage area. The pixel colour depends on the Eb/Nt or C/I margin value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties).
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TX ic E TXi ic C i Req Eb Nt Req CI For each layer, a pixel is covered if ----b- – Q P – CCPCH M P – CCPCH or --- – Q P – CCPCH M P – CCPCH . N t P – CCPCH I P – CCPCH
Each layer is assigned a colour and displayed with intersections between layers. •
Cell Edge Coverage Probability (%) Atoll calculates the cell edge coverage probability on each pixel of the TX i ic best server coverage area. The pixel colour depends on the cell edge coverage probability value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction
properties).
TX i ic
C --- I P – CCPCH
For
each
layer,
a
pixel
is
covered
if
TX i ic
E b --- N t P – CCPCH
Req
Q P – CCPCH
or
CECP
Req
Q P – CCPCH . Each layer is assigned a colour and displayed with intersections between layers. CECP
9.4.2 DwPCH Reception Analysis (C/I) C This coverage prediction calculates and displays the C/I on the DwPCH, --- . The coverage prediction is calculated for a I DwPCH given set of a terminal type, a mobility type, a service, a carrier, and for DwPTS. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the C/I considering: • • •
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters. TX i ic
TX ic
C i Min Req The pixels in the TX i ic coverage area where RSCP P – CCPCH Max (TAdd P – CCPCH,RSCP P – CCPCH) and --- Q DwPCH I DwPCH are covered and coloured according to the selected display option. TX
TX ic
TX ic i
i
RSCP DwPCH C i = -----------------------------------------Where --- I DwPCH TX ic i N Tot – DL TX i ic
RSCP DwPCH
TX ic i
P DwPCH = ---------------LT
The downlink total noise is calculated as follows: TX i ic
TX i ic
TX i ic
Term
N Tot – DL = I Intra – DL + I Extra – DL + I IC – DL ic jc + N 0 Where TX i ic
TX i ic
I Intra – DL = RSCP DwPCH With TX i ic
TX i
=
I Extra – DL =
TX i
Ortho
1 – F DL
TX i
Term
1 – F JD
and = 0 1
Without Useful Signal Total Noise
TX j ic
RSCPDwPCH ji
TX jc j
RSCPDwPCH TX
j I IC – DL ic jc = ---------------------------------------F IRF ic jc
I IC – DL ic jc is the inter-carrier interference from a carrier jc to another carrier ic on the downlink, which is reduced by the interference reduction factor F IRF ic jc defined for the pair (ic, jc).
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AT330_TRR_E1 TX
Eb Nt
Term
i
L Path L L L Body L Indoor M Shadowing L T = ----------------------------------------------------------------------------------------------------------------------TX i Term G G
TX
i
Term
and N 0
are defined in "Definitions and Formulas" on page 595.
Coverage Display It is possible to colour the transmitter service areas using a unique colour per transmitter, or colour the pixels in the coverage areas by any transmitter attribute or other criteria such as: •
C/I (dB) Atoll calculates the C/I on each pixel of the TX i ic best server coverage area. The pixel colour depends on the C/I level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For each layer, a pixel is covered if TX i ic
C --- Threshold . Each layer is assigned a colour and displayed with intersections between layers. I DwPCH •
C/I Margin (dB) Atoll calculates the C/I margin on each pixel of the TX i ic best server coverage area. The pixel colour depends on the C/I margin value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For each layer, a pixel is TX i ic
C Req CI – Q DwPCH M DwPCH . Each layer is assigned a colour and displayed with intersections between covered if --- I DwPCH layers. •
Cell Edge Coverage Probability (%) Atoll calculates the cell edge coverage probability on each pixel of the TX i ic best server coverage area. The pixel colour depends on the cell edge coverage probability value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab TX ic
C i (Prediction properties). For each layer, a pixel is covered if --- I DwPCH
Req
Q DwPCH . Each layer is assigned a colour CECP
and displayed with intersections between layers.
9.4.3 Downlink TCH RSCP Coverage This coverage prediction calculates and displays the RSCP for the downlink traffic channel, RSCP TCH – DL . The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for a downlink timeslot. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest PCCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the RSCP considering: • • • The
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters. pixels
in
the
TX ic i
TX i ic
coverage
area
where
TX i ic
Min
RSCP P – CCPCH Max (TAdd P – CCPCH,RSCP P – CCPCH)
and
Req
RSCP TCH – DL RSCP TCH – DL Service Mobility are covered and coloured according to the selected display option. TX ic i
Where RSCP TCH – DL is given by: Max
TX ic P TCH – DL Service i RSCP TCH – DL = ------------------------------------------Model LT
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Term
i
Model
L Path L L L Body L Indoor M Shadowing Max = ----------------------------------------------------------------------------------------------------------------------- and P TCH – DL Service is the maximum downlink traffic power TX i Term G G defined for the selected service. Model LT
Model
In L T
, G
TX
i
SA
= G DL and L
TX
i
SA
= L DL are calculated according to the smart antenna modelling method used, for
Max
P TCH – DL Service , if a smart antenna is available in the downlink. Otherwise, G
TX i
and L
TX i
are read from the main antenna
model. Coverage Display It is possible to colour the transmitter service areas using a unique colour per transmitter, or colour the pixels in the coverage areas by any transmitter attribute or other criteria such as: •
DL TCH RSCP (dBm) Atoll calculates the DL TCH RSCP on each pixel of the TX i ic best server coverage area. The pixel colour depends on the RSCP level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For each layer, a pixel is TX i ic
covered if RSCP TCH – DL Threshold . Each layer is assigned a colour and displayed with intersections between layers. •
RSCP Margin (dB) Atoll calculates the RSCP margin on each pixel of the TX i ic best server coverage area. The pixel colour depends on the RSCP margin value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For each layer, a TX i ic
Req
RSCP
pixel is covered if RSCP TCH – DL – RSCP TCH – DL Service Mobility M TCH – DL . Each layer is assigned a colour and displayed with intersections between layers. •
Cell Edge Coverage Probability (%) Atoll calculates the cell edge coverage probability on each pixel of the TX i ic best server coverage area. The pixel colour depends on the cell edge coverage probability value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab TX i ic
(Prediction properties). For each layer, a pixel is covered if RSCP TCH – DL
Req
CECP
RSCP TCH – DL Service Mobility .
Each layer is assigned a colour and displayed with intersections between layers.
9.4.4 Uplink TCH RSCP Coverage This coverage prediction calculates and displays the RSCP for the uplink traffic channel, RSCP TCH – UL . The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for an uplink timeslot. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the RSCP considering: • • • The
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters. pixels
in
TX i ic
the
TX i ic
Req
coverage
area
where
TX i ic
Min
RSCP P – CCPCH Max (TAdd P – CCPCH,RSCP P – CCPCH)
RSCP TCH – UL RSCP TCH – UL Service Mobility are covered and coloured according to the selected display option. TX i ic
Where RSCP TCH – UL is given by: Term
TX i ic P Max RSCP TCH – UL = -------------Model LT
630
and
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 9: TD-SCDMA Networks
AT330_TRR_E1 TX
i
Term
Model
L Path L L L Body L Indoor M Shadowing Term = ----------------------------------------------------------------------------------------------------------------------- and P Max is the maximum uplink traffic power defined for the TX i Term G G selected terminal. Model LT
Model
In L T
,G
TX
i
SA
= G UL and L
TX
i
SA
Term
= L UL are calculated according to the smart antenna modelling method used, for P Max , if
a smart antenna is available in the uplink. Otherwise, G
TX i
and L
TX i
are read from the main antenna model.
Coverage Display It is possible to colour the transmitter service areas using a unique colour per transmitter, or colour the pixels in the coverage areas by any transmitter attribute or other criteria such as: •
UL TCH RSCP (dBm) Atoll calculates the UL TCH RSCP on each pixel of the TX i ic best server coverage area. The pixel colour depends on the RSCP level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For each layer, a pixel is TX i ic
covered if RSCP TCH – UL Threshold . Each layer is assigned a colour and displayed with intersections between layers. •
RSCP Margin (dB) Atoll calculates the RSCP margin on each pixel of the TX i ic best server coverage area. The pixel colour depends on the RSCP margin value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For each layer, a TX ic i
Req
RSCP
pixel is covered if RSCP TCH – UL – RSCP TCH – UL Service Mobility M TCH – UL . Each layer is assigned a colour and displayed with intersections between layers. •
Cell Edge Coverage Probability (%) Atoll calculates the cell edge coverage probability on each pixel of the TX i ic best server coverage area. The pixel colour depends on the cell edge coverage probability value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab TX i ic
(Prediction properties). For each layer, a pixel is covered if RSCP TCH – UL
Req
CECP
RSCP TCH – UL Service Mobility .
Each layer is assigned a colour and displayed with intersections between layers.
9.4.5 Downlink Total Noise This coverage prediction calculates and displays the total noise on the downlink, N Tot – DL . The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for a downlink timeslot. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the downlink noise for all the carriers but keeps the worst case value, i.e., the most interfered carrier. You can choose to display the minimum, the maximum, or the average total noise values from among the values calculated for all the carriers. Pixels are covered and coloured according to the total downlink noise thresholds defined in the display options. Total downlink noise is given by: N Tot – DL =
Term
RSCP TCH – DL + RSCP OCCH + N 0
All TX, c, and TS
P TCH – DL P OCCH - and RSCP OCCH = -------------With RSCP TCH – DL = ------------------Model Model LT LT TX
i
Term
Model
L Path L L L Body L Indoor M Shadowing = ----------------------------------------------------------------------------------------------------------------------- and P TCH – DL and P TCH – DL are respectively the downlink traffic TX Term i G G power and the other common control channel power for the selected timeslot. Model LT
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Model
In L T
, G
TX
i
SA
= G DL and L
©Forsk 2015 TX
i
SA
= L DL are calculated according to the smart antenna modelling method used, for
Max
P TCH – DL Service , if a smart antenna is available in the downlink. Otherwise, G
TX
i
and L
TX
i
are read from the main antenna
model.
9.4.6 Downlink Service Area Analysis (Eb/Nt) or (C/I) E C These coverage predictions calculate and display the Eb/Nt or C/I on the downlink traffic channel, ----b- or --- . N t TCH – DL I TCH – DL The coverage predictions are calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for a downlink timeslot. The best servers for the coverage predictions are determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage predictions are calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform these coverage predictions for the best carrier, Atoll calculates the Eb/Nt or C/I considering: • • •
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
The
pixels
in
TX i ic
the
coverage
area
where
TX i ic
TX i ic
TX ic
Min
RSCP P – CCPCH Max (TAdd P – CCPCH,RSCP P – CCPCH) , TX i ic
Eb C i Req Req Req RSCP TCH – DL RSCP TCH – DL Service Mobility , and ----- Q TCH – DL or --- Q TCH – DL are covered and N t TCH – DL I TCH – DL coloured according to the selected display option. TX i ic
TX i
TX i
TX i ic
TX ic i E b TXi ic RSCP TCH – DL RSCP TCH – DL Div C - G Proc - G Div = --------------------------------------------= --------------------------------------------Where ----- DL G DL and --- DL TX ic TX i ic N t TCH – DL I TCH – DL i N Tot – DL N Tot – DL Max
TX i ic P TCH – DL Service With RSCP TCH – DL = ------------------------------------------ Eb Nt DL LT TX
Eb Nt
Term
i
DL
L Path L L L Body L Indoor M Shadowing Max LT = ----------------------------------------------------------------------------------------------------------------------- and P TCH – DL Service is the maximum downlink traffic TX Term i G G power defined for the selected service. Eb Nt DL
Eb Nt
In L T
DL
, G
TX
i
SA
= G DL and L
TX
i
SA
= L DL are calculated according to the smart antenna modelling method used, for
Max
P TCH – DL Service , if a smart antenna is available in the downlink. Otherwise, G
TX i
and L
TX i
model. TX ic i
TX ic i
TX ic i
Term
N Tot – DL = I Intra – DL + I Extra – DL + I IC – DL ic jc + N 0 Where
TX i TX i ic TX i ic TX i ic TXi Ortho Term I Intra – DL = 1 – F DL 1 – F JD + 1 – RSCP TCH – DL + RSCP OCCH TX i ic
With RSCP OCCH
TX i ic
I Extra – DL =
TX ic i
P OCCH = --------------------- Eb Nt DL LT TX j ic
TX j ic
RSCPTCH – DL + RSCPOCCH ji
TX j jc
TX j jc
RSCPTCH – DL + RSCPOCCH TX
j I IC – DL ic jc = --------------------------------------------------------------------------F IRF ic jc
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are read from the main antenna
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 9: TD-SCDMA Networks
AT330_TRR_E1
I IC – DL ic jc is the inter-carrier interference from a carrier jc to another carrier ic on the downlink, which is reduced by the interference reduction factor F IRF ic jc defined for the pair (ic, jc). Coverage Display It is possible to colour the transmitter service areas using a unique colour per transmitter, or colour the pixels in the coverage areas by any transmitter attribute or other criteria such as: •
Max Eb/Nt or Max C/I (dB) Atoll calculates the Eb/Nt or C/I on each pixel of the TX i ic best server coverage area. The pixel colour depends on the Eb/Nt or C/I level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For each layer, a TX ic E b TXi ic C i Threshold or --- Threshold . Each layer is assigned a colour and displayed pixel is covered if ----- N t TCH – DL I TCH – DL
with intersections between layers. •
Effective Eb/Nt or Effective C/I (dB) Atoll calculates the effective Eb/Nt or C/I on each pixel of the TX i ic best server coverage area. The pixel colour depends on the effective Eb/Nt or C/I level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For
each
layer,
a
pixel
is
covered
if
E TXi ic Req Min ----b- Q TCH – DL Threshold N t TCH – DL
or
C TXi ic Req Min --- Q TCH – DL Threshold . Each layer is assigned a colour and displayed with intersections between I TCH – DL layers. •
Eb/Nt Margin or C/I Margin (dB) Atoll calculates the Eb/Nt or C/I margin on each pixel of the TX i ic best server coverage area. The pixel colour depends on the Eb/Nt or C/I margin value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). TX ic E b TX i ic C i Req Eb Nt Req CI – Q TCH – DL M TCH – DL or --- – Q TCH – DL M TCH – DL . Each For each layer, a pixel is covered if ----- N t TCH – DL I TCH – DL
layer is assigned a colour and displayed with intersections between layers. •
Required Power (dBm) Atoll calculates the downlink required power on each pixel of the TX i ic best server coverage area. The pixel colour depends on the required power level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). Req
Q TCH – DL Req Req - P Max For each layer, a pixel is covered if P TCH – DL Threshold , where P TCH – DL = --------------------------TCH – DL Service or TX ic i E b --- N t TCH – DL Req
Q TCH – DL Req Max P TCH – DL = ------------------------ P TCH – DL Service . Each layer is assigned a colour and displayed with intersections TX i ic C --- I TCH – DL between layers. •
Required Power Margin (dB) Atoll calculates the downlink required power margin on each pixel of the TX i ic best server coverage area. The pixel colour depends on the required power margin value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). Req
P TCH – DL =
For
each
Req Q TCH – DL --------------------------TX i ic E b
layer, Max
a
pixel
is
covered Req
P TCH – DL Service or P TCH – DL =
---- N t TCH – DL
if
Req
Max
P TCH – DL – P TCH – DL Service M arg in ,
Req Q TCH – DL ------------------------TX i ic
C --- I TCH – DL
where
Max
P TCH – DL Service . Each layer is assigned
a colour and displayed with intersections between layers.
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•
©Forsk 2015
Cell Edge Coverage Probability (%) Atoll calculates the cell edge coverage probability on each pixel of the TX i ic best server coverage area. The pixel colour depends on the cell edge coverage probability value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction
properties).
TX i ic
C --- I TCH – DL
For
each
layer,
a
pixel
is
covered
if
TX i ic
E b --- N t TCH – DL
Req
Q TCH – DL
or
CECP
Req
Q TCH – DL . Each layer is assigned a colour and displayed with intersections between layers. CECP
9.4.7 Uplink Service Area Analysis (Eb/Nt) or (C/I) E C These coverage predictions calculate and display the Eb/Nt or C/I on the uplink traffic channel, ----b- or --- . N t TCH – UL I TCH – UL The coverage predictions are calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for an uplink timeslot. The best servers for the coverage predictions are determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage predictions are calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform these coverage predictions for the best carrier, Atoll calculates the Eb/Nt or C/I considering: • • • The
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters. pixels
in
TX i ic
the
coverage
area
where
TX i ic
Min
RSCP P – CCPCH Max (TAdd P – CCPCH,RSCP P – CCPCH) ,
TX ic TX i ic E b TXi ic C i Req Req Req RSCP TCH – UL RSCP TCH – UL Service Mobility , and ----- Q TCH – UL or --- Q TCH – UL are covered and N t TCH – UL I TCH – UL
coloured according to the selected display option. TX i ic
TX i ic
TX ic i E b TXi ic RSCP TCH – UL RSCP TCH – UL Div C - G Proc --- ------------------------------------------------- G Div = ------------------------------------------------ G Where ----- and UL UL UL TX i ic TX i ic I TCH – UL = N t TCH – UL N Tot – UL N Tot – UL Term
Term
Req
Req
Term TX i ic Q TCH – UL Q TCH – UL P Max Term Term Term - or P Term - and P Req = P Max --------------------------With RSCP TCH – UL = ---------------------Req = P Max ------------------------TX i ic TX i ic Eb Nt UL E C b --- ----- LT I TCH – UL N t TCH – UL Eb Nt UL
LT
TX i
Eb Nt UL
Term
L Path L L L Body L Indoor M Shadowing Term = ----------------------------------------------------------------------------------------------------------------------- and P Max is the maximum power defined for the selected TX i Term G G
terminal. Eb Nt UL
In L T
,G
TX i
SA
= G UL and L
TX i
SA
Term
= L UL are calculated according to the smart antenna modelling method used, for P Max ,
if a smart antenna is available in the uplink. Otherwise, G
TX i
and L
TX i
are read from the main antenna model.
Coverage Display It is possible to colour the transmitter service areas using a unique colour per transmitter, or colour the pixels in the coverage areas by any transmitter attribute or other criteria such as: •
Max Eb/Nt or Max C/I (dB) Atoll calculates the Eb/Nt or C/I on each pixel of the TX i ic best server coverage area. The pixel colour depends on the Eb/Nt or C/I level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For each layer, a TX i ic
TX i ic
Eb C Threshold or --- Threshold . Each layer is assigned a colour and displayed pixel is covered if ----- N t TCH – UL I TCH – UL with intersections between layers. •
634
Effective Eb/Nt or Effective C/I (dB)
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 9: TD-SCDMA Networks
AT330_TRR_E1
Atoll calculates the effective Eb/Nt or C/I on each pixel of the TX i ic best server coverage area. The pixel colour depends on the effective Eb/Nt or C/I level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For
each
layer,
a
pixel
is
covered
E b TXi ic Req Min ----- Q TCH – UL Threshold N t TCH – UL
if
or
C TXi ic Req Min --- Q TCH – UL Threshold . Each layer is assigned a colour and displayed with intersections between I TCH – UL layers. •
Eb/Nt Margin or C/I Margin (dB) Atoll calculates the Eb/Nt or C/I margin on each pixel of the TX i ic best server coverage area. The pixel colour depends on the Eb/Nt or C/I margin value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). TX ic E TXi ic C i Req Eb Nt Req CI For each layer, a pixel is covered if ----b- – Q TCH – UL M TCH – UL or --- – Q TCH – UL M TCH – UL . Each N t TCH – UL I TCH – UL
layer is assigned a colour and displayed with intersections between layers. •
Required Power (dBm) Atoll calculates the uplink required power on each pixel of the TX i ic best server coverage area. The pixel colour depends on the required power level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). Req
For each layer, a
pixel is covered if
Term
P Req Threshold , where
Q TCH – UL Term - P Term P Req = --------------------------Max TX i ic E ----b- N t TCH – UL
or
Req
Q TCH – UL Term - P Term P Req = ------------------------Max . Each layer is assigned a colour and displayed with intersections between layers. TX ic i C -- I TCH – UL •
Required Power Margin (dB) Atoll calculates the uplink required power margin on each pixel of the TX i ic best server coverage area. The pixel colour depends on the required power margin value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction Req
Q TCH – UL Term Term Term - P Term properties). For each layer, a pixel is covered if P Req – P Max M arg in , where P Req = --------------------------Max or TX i ic E b --- N t TCH – UL Req
Q TCH – UL Term - P Term P Req = ------------------------Max . Each layer is assigned a colour and displayed with intersections between layers. TX ic i C -- I TCH – UL •
Cell Edge Coverage Probability (%) Atoll calculates the cell edge coverage probability on each pixel of the TX i ic best server coverage area. The pixel colour depends on the cell edge coverage probability value. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction
properties).
TX i ic
C --- I TCH – UL
For
each
layer,
a
pixel
is
covered
if
TX i ic
E b --- N t TCH – UL
Req
Q TCH – UL
or
CECP
Req
Q TCH – UL . Each layer is assigned a colour and displayed with intersections between layers. CECP
9.4.8 Effective Service Area Analysis (Eb/Nt) or (C/I) These coverage predictions consist of pixels covered by the both the uplink and the downlink service areas. These coverage E C predictions calculate the Eb/Nt or C/I on the downlink and uplink traffic channels, ----b- or --- and N t TCH – DL I TCH – DL
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E b C ---or --- , and display the pixels where both downlink and uplink Eb/Nt or C/I are above the required quality N t TCH – UL I TCH – UL thresholds. The coverage predictions are calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for all the 6 timeslots. The best servers for the coverage predictions are determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage predictions are calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform these coverage predictions for the best carrier, Atoll calculates the Eb/Nt or C/I considering: • • •
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
The pixels in the TX i ic coverage area are covered and coloured according to the selected display option if all the following conditions are satisfied: TX i ic
Min
•
RSCP P – CCPCH Max (TAdd P – CCPCH,RSCP P – CCPCH)
•
RSCP TCH – DL RSCP TCH – DL Service Mobility
•
RSCP TCH – UL RSCP TCH – UL Service Mobility
•
E b i C i Req Req --- Q TCH – DL or --- Q TCH – DL for any of the 6 timeslots N t TCH – DL I TCH – DL
•
E b C Req Req --- Q TCH – UL or --- Q TCH – UL for any of the 6 timeslots N t TCH – UL I TCH – UL
TX i ic
Req
TX i ic
Req
TX ic
TX ic
TX i ic
TX i ic
9.4.9 Cell to Cell Interference This coverage prediction calculates and displays the interference received by cells receiving in uplink from other cells which are transmitting in downlink. The timeslot configuration of each cell defines the direction of the link at any given instance. During each subframe, the direction of the link changes twice (downlink to uplink, and then uplink to downlink). These transitions are referred to as switching points. The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and a timeslot. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest PCCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the RSCP considering: • • •
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
The mobility, service, and terminal are used to calculate the best server coverage of the interfered cell. Assuming that a transmitter TX j is interfering a studied transmitter TX i on a timeslot, on the same carrier ic or on another carrier jc, the cell to cell interference is given by: TX jc j
I C2C TX i TX j =
TX ic j
TX ic j
TX jc j
RSCPTCH – DL + RSCPOCCH
j RSCPTCH – DL + RSCPOCCH + --------------------------------------------------------------------------F IRF ic jc TX
TX j
TX j ic
Where
TX ic P TCH – DL j RSCP TCH – DL = --------------------------LT
TX ic j RSCP TCH – DL
636
TX j ic
TX j
TX j jc
and
TX jc P TCH – DL j RSCP TCH – DL = --------------------------LT TX j jc
TX j
TX jc P TCH – DL G Ant P TCH – DL G Ant - ---------- and RSCP TCHj – DL = ------------------- ---------- otherwise. = ------------------TX TX j LT LT j L Ant L Ant
using
a
smart
antenna,
and
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TX ic j RSCP OCCH
TX ic j
ITU526 – 5
L T = L Path ITU526 – 5
L Path
TX
TX jc j
j
TX
j
TX jc P OCCH G Ant P OCCH G Ant j - ---------- otherwise. and RSCP OCCH = --------------= ---------------- ---------TX TX LT LT j j L Ant L Ant TX
j
TX
i
L TX L RX
is the path loss calculated using the ITU526-5 propagation model without antenna loss.
is the angle for the smart antenna pattern. TX j
L Ant is the main antenna attenuation. TX j
G Ant is the main antenna gain. Atoll calculates the cell to cell interference on each pixel of the TX i ic best server coverage area. The pixel colour depends on the cell to cell interference level. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). For each layer, a pixel is covered if I C2C TX i TX j Threshold . Each layer is assigned a colour and displayed with intersections between layers.
9.4.10 UpPCH Interference UpPCH is usually carried by the UpPTS timeslot. However, if the interference on UpPTS is high, from unsynchronised DwPTS or TS0 timeslots of other cells, it is possible to shift the UpPCH to TS1. This is called UpPCH shifting. If some cells in a network use UpPCH shifting, you can use this coverage prediction to study the interference on the shifted UpPCH of these cells from other cells. The interference from other cells is in this case generated by the traffic on the TS1 of interfering cells. This coverage prediction calculates and displays the uplink interference on the TS1, I TS1 – UL . The coverage prediction is calculated for a given set of a terminal type, a mobility type, a service, a carrier, and for TS1. The best server for the coverage prediction is determined according to the P-CCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage prediction is calculated for the selected carrier. If the selected carrier does not exist on a transmitter, there will not be any pixels covered by this transmitter. If you perform this coverage prediction for the best carrier, Atoll calculates the interference for all the carriers but keeps the worst case value, i.e., the most interfered carrier. You can choose to display the minimum, the maximum, or the average total noise. The coverage prediction is calculated using the main antenna. TX ic i
TX ic i
Pixels in the TX i ic coverage area where RSCP P – CCPCH TAdd P – CCPCH Mobility and I TS1 – UL Threshold are covered and coloured according to the selected display option. The uplink interference on TS1 is calculated from the uplink load calculated in the simulations or manually defiend for the TS1. TX i ic
TX i
The uplink interference on TS1 is given by: I TS1 – UL = N 0
TX i ic
X TS1 – UL ---------------------------------TX ic 1 – X i TS1 – UL
9.4.11 HSDPA Predictions This coverage prediction calculates and displays the peak RLC throughput or the Peak MAC throughput per pixel covered by HSDPA cells. The coverage prediction is calculated for a given set of an HSDPA terminal type, a mobility type, an HSDPA service, a carrier, and for all downlink timeslots. The best server for the coverage prediction is determined according to the PCCPCH RSCP from the carrier with the highest P-CCPCH power, or from the master carrier in case of N-frequency mode compatible transmitters. Afterwards, the coverage predictions are calculated for the selected carrier. If the selected carrier does not exist on a transmitter or if it does not support HSDPA, there will not be any pixels covered by this transmitter. If you perform these coverage predictions for the best carrier, Atoll calculates the RLC or Peak MAC throughput considering: • • •
the preferred carrier of the selected service, or the carrier with the highest P-CCPCH power, if no preferred carrier is defined for the service, or the master carrier in case of N-frequency mode compatible transmitters.
The pixels in the TX i ic coverage area are covered and coloured if: •
TX ic i
RSCP P – CCPCH TAdd P – CCPCH Mobility ,
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TX ic i
•
E C Req --- Q HS – PDSCH , and N t HS – PDSCH
•
E C ---is enough to select a bearer for the pixels. N t HS – PDSCH
TX i ic
For more information on HSDPA bearer selection, see "HSDPA Part of the Algorithm" on page 622. Coverage Display It is possible to colour the pixels in the coverage areas by criteria such as: TX ic i
•
Min HS-PDSCH RSCP: On each pixel, Atoll calculates RSCP HS – SCCH for all timeslots and selects the lowest value.
•
Average HS-PDSCH RSCP: On each pixel, Atoll calculates RSCP HS – SCCH for all timeslots and calculates the average of
TX i ic
these values. TX i ic
•
Max HS-PDSCH RSCP: On each pixel, Atoll calculates RSCP HS – SCCH for all timeslots and selects the highest value.
•
E Min HS-PDSCH Ec/Nt: On each pixel, Atoll calculates ----C- for all timeslots and selects the lowest value. N t HS – PDSCH
•
E Average HS-PDSCH Ec/Nt: On each pixel, Atoll calculates ----C- for all timeslots and calculates the average N t HS – PDSCH
TX i ic
TX i ic
of these values. •
E TXi ic Max HS-PDSCH Ec/Nt: On each pixel, Atoll calculates ----C- for all timeslots and selects the highest value. N t HS – PDSCH
•
Peak RLC Throughput: After selecting the bearer, Atoll reads the corresponding RLC peak throughput. This is the highest throughput that the bearer can provide on each pixel. The pixel colour depends on the peak RLC throughput. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). Each layer is assigned a colour and displayed with intersections between layers.
•
Peak MAC Throughput: Atoll displays the Peak MAC throughput ( R DL ) provided on each pixel. The Peak MAC
MAC
throughput is calculated as follows: MAC
R DL
= S Block 500
Where, S Block is the transport block size (in kbits) of the selected HSDPA bearer; it is defined for each HSDPA bearer in the related table. The value 500 corresponds to the number of blocks per second (there are 4 blocks per TTI and 2000 2000 TTI in one second, i.e ------------ blocks per second). 4 The pixel colour depends on the Peak MAC throughput. Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as thresholds defined in the Display tab (Prediction properties). Each layer is assigned a colour and displayed with intersections between layers. •
E b TXi ic TS Max DL A-DPCH Eb/Nt: Atoll displays the A-DPCH Eb/Nt at the receiver ( ----- ) for the best server and the N t TCH – DL – Max selected timeslot. No power control is performed as in simulations. Here, Atoll determines downlink traffic channel quality at the receiver for a maximum traffic channel power allowed for the best server.
•
E b TX i ic TS Max UL A-DPCH Eb/Nt: Atoll displays the A-DPCH Eb/Nt at the best server ( ----- ) and the selected N t TCH – UL – Max timeslot. No power control is performed as in simulations. Here, Atoll determines uplink traffic channel quality for the maximum terminal power allowed.
638
TX i ic
•
HS-SCCH Power: On each pixel, Atoll calculates P HS – SCCH for the selected timeslot.
•
HS-SCCH RSCP: On each pixel, Atoll calculates RSCP HS – SCCH for the selected timeslot.
•
E TX i ic HS-SCCH Ec/Nt: On each pixel, Atoll calculates ----c- for the selected timeslot. N t HS – SCCH
•
HS-SICH Power: On each pixel, Atoll calculates P HS – SICH for the selected timeslot.
TX i ic
Mi
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i
•
HS-SICH RSCP: On each pixel, Atoll calculates RSCP HS – SICH for the selected timeslot.
•
E HS-SICH Ec/Nt: On each pixel, Atoll calculates ----c- for the selected timeslot. N t HS – SICH
•
HS-PDSCH RSCP: On each pixel, Atoll calculates RSCP HS – PDSCH for the selected timeslot.
•
E c TXi ic HS-PDSCH Ec/Nt: On each pixel, Atoll calculates ----- for the selected timeslot. N t HS – PDSCH
M
i
TX ic i
9.5 Smart Antenna Modelling Atoll calculates the smart antenna gains and losses in the direction of a user during the simulations, and in the direction of each pixel in coverage predictions. During simulations, Atoll determines the gains and losses using the smart antenna models. In coverage predictions, Atoll determines the gains and losses from the angular distributions calculated during the simulations for each timeslot and stored in the Cell Parameters per Timeslot table. If a smart antenna model is only downlink or only uplink, the other direction uses the main antenna gain and losses for calculations. Therefore, •
If a smart antenna is available on the downlink and uplink: TX
SA
TX
SA
TX
SA
TX
SA
G UL = G UL , L UL = L UL and G DL = G DL , L DL = L DL •
If a smart antenna is available on the downlink only: TX
SA
TX
SA
TX
TX
TX
G DL = G DL , L DL = L DL and G UL = G Ant , L UL = L •
= L Total – UL
TX
= L Total – DL
If a smart antenna is available on the uplink only: TX
SA
TX
SA
TX
TX
TX
G UL = G UL , L UL = L UL and G DL = G Ant , L DL = L •
TX
If no smart antenna equipment is defined: TX
TX
TX
TX
G DL = G UL = G Ant , L UL = L
TX
TX
= L Total – UL , and L DL = L
TX
= L Total – DL
9.5.1 Modelling in Simulations 9.5.1.1 Grid of Beams Modelling A grid-of-beams smart antenna, called GOB, consists of more than one directional antenna pattern (beam) in different directions. Each beam of a GOB has a different azimuth so that the GOB as a whole covers an entire sector. During the simulations, Atoll determines the most suitable beam from the GOB for each user served by the smart antenna. The most suitable beam (best beam) is the one which provides the highest gain towards the served user: BeamBest = Beam H
H V Max G Beam – L Beam – L Beam V
Where G Beam , L Beam , and L Beam are the gains, horizontal, and vertical attenuations of the beams of the GOB. In words, the best beam is the one among all the beams of a GOB that has the highest difference between gain, and horizontal and vertical SA
SA
SA
SA
attenuations. The gains and losses of the GOB ( G DL , G UL , L DL , and L UL ) are determined from the selected best beam. The following example shows how Atoll calculates the GOB gains and losses. Example: Let us assume a GOB with 5 beams that have the same vertical patterns, and whose horizontal patterns are pointed towards different directions as shown in the figure below:
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Figure 9.3: Grid Of Beams Modelling Let us assume that all the beams and the main antenna have the same 18 dBi gain, and the vertical attenuation at the user location is 15 dB, which is also the same for all the beams because we assume that the vertical patterns are the same. If the user is located at = 70 azimuth, as shown in the figure below, Atoll determines the best beam, which has the highest gain towards , as follows: Beam
Gain (dBi)
Horizontal Vertical Attenuation (dB) Attenuation (dB)
G Beam – L Beam – L Beam
Total Gain (dB)
H
V
0°
18
60
15
18 - 60 - 15
-57
30°
18
60
15
18 - 60 - 15
-57
60°
18
2.21
15
18 - 2.21- 15
0.79
-30°
18
60
15
18 - 60 - 15
-57
-60°
18
60
15
18 - 60 - 15
-57
Transmitter Centre of the pixel where the served user is located
Angle between the user and the transmitter azimuth
Figure 9.4: GOB Modelling - Determination of the Best Beam In our example, the total gain of the beam at 60° is the highest. Therefore this beam is selected as the best beam. If this beam has been selected in the downlink, SA
SA
H
V
G DL = 18 dB and L DL = L Beam + L Beam = 17.21 dB If this beam has been selected in the uplink, SA
SA
H
V
G UL = 18 dB and L UL = L Beam + L Beam = 17.21 dB
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9.5.1.2 Adaptive Beam Modelling An adaptive beam smart antenna is capable of steering a given antenna pattern towards the direction of the served signal. In Atoll, this is modelled using a single antenna pattern, called a beam because of its highly directional shape. During the simulations, this adaptive beam is oriented in the direction of each served user in order to model the effect of the smart antenna. SA
SA
SA
The adaptive beam gains ( G DL and G UL ) are the antenna gains defined for the beam, and the adaptive beam losses ( L DL and SA
H
V
L UL ) are the horizontal and vertical pattern attenuations L Beam + L Beam towards the user direction. The following example shows how Atoll calculates the adaptive beam gains and losses. Example: Let us assume an adaptive beam smart antenna selected for a transmitter along with a main antenna. Let us assume that the adaptive beam and the main antenna have the same 18 dBi gain, and the vertical attenuation at the user location is 15 dB. If the user is located at = 60 azimuth, as shown in the figure below:
Transmitter Centre of the pixel where the served user is located
Angle between the user and the transmitter azimuth
Figure 9.5: Adaptive Beam Modelling - Determination of the Best Beam If the adaptive beam smart antenna is selected in the downlink, the gain and losses of the adaptive beam at are: SA
SA
H
V
G DL = 18 dB and L DL = L Beam + L Beam = 15 dB If the adaptive beam smart antenna is selected in the uplink, the gain and losses of the adaptive beam at are: SA
SA
H
V
G UL = 18 dB and L UL = L Beam + L Beam = 15 dB H
In fact, as the ideal beam steering algorithm steers the beam towards the served user, L Beam = 0 . These values are used in interference calculation to determine the downlink interfering signal due to transmission towards the served user, as well as for calculating the uplink interfering signals received at transmitter when decoding signal received from the served user.
9.5.1.3 Statistical Modelling A statistical modelling approach is also available in Atoll which can be used to model the effect of smart antennas through C/ I gains. You can create smart antenna equipment in Atoll based on the statistical approach by providing C/I gains and their cumulative probabilities for different spreading angles, Spread . You can assign a spreading angle to each clutter class in your document. Atoll reads the clutter class in which the served user is located to determine the spreading angle. Different clutter types have different spreading effects on the propagation of radio waves. Urban and dense urban clutter types introduce more multipath and spread the signal at a wider angle than an open or rural clutte type. Once you have assigned the spreading angles to clutter classes, you can enter the C/I gains and their cumulative probabilities for each spreading angle, in the smart antenna equipment based on the statistical model. For each smart antenna equipment based on statistical modelling, you can set a probability threshold, TProb
SA
.
To find the smart antenna gain, Atoll determines the clutter class of the served user, it reads the spreading angle from the clutter class properties, it reads the probability threshold from the smart antenna properties, and reads the smart antenna C/ I gain defined for the Probability = 1 – TProb
SA
corresponding to the spreading angle.
The following example shows how Atoll calculates the statistical C/I gains and losses.
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Example: Let us assume that the served user is located at a an urban clutter class with Spread = 10 . The smart antenna equipment SA
SA
has TProb = 80 % . Atoll will read the smart antenna C/I gain G for Prob = 20 % . If a gain for the exact probability value of 20% is not defined, Atoll linearly interpolates the gain value from the two surrounding values. If G
SA Prob = 19%
= 4.6298 dB and G
SA Prob = 20.4%
= 4.7196 dB , then G
SA Prob = 20%
= 4.6941 dB
The smart antenna gains are the same for uplink and downlink. Their are no losses for this type of smart antenna equipment. Negative values of C/I gains are considered as losses.
9.5.1.4 Beamforming Smart Antenna Models See "Beamforming Smart Antenna Models" on page 43.
9.5.1.5 3rd Party Smart Antenna Modelling 3rd party smart antenna models can be used in Atoll to determine the gains and losses during the simulations for a given user distribution generated. The smart antenna gains and losses are used during the simulations and the results are stored in the Cell Parameters per Timeslot table, which can be used in coverage predictions.
9.5.2 Construction of the Geographic Distributions During simulations, Atoll uses the smart antenna model selected for each transmitter to calculate the smart antenna gains and losses. These values are calculated and stored for each user generated for the simulations. Therefore, these values are calculated and are available for the given locations of the users, i.e., points, only. Atoll uses the Angular Step value that you set when creating and running simulations to construct the geographic distributions of these results. Once Atoll has calculated the downlink traffic power and the uplink load using the smart antenna gains and losses determined as explained in the previous section, at the location of a given user, it calculates the same for points located at the angle equal to that of the Angular Step of the simulations. At the end of the simulations, Atoll has a number of points, Angular Step apart, available with the values of these results. The geographic distribution of these results, i.e., downlink traffic power and uplink loads, is constructed by connecting the resulting value points. The following example explains how the geographic distribution of downlink traffic power is created. The geographic distribution of uplink loads is constructed in the same manner. Example: Let us assume a smart antenna equipment using adaptive beam modelling. The angular step defined for the simulations is Step = 30 . Therefore, the results are calculated for each point located at regular steps of 30 , i.e., 12 points. The downlink traffic power at the served user (W) with the adaptive beam pointing in the user’s direction is P W . The downlink traffic powers, using the same adaptive beam pointed towards the served user, at the 12 other points are also determined.
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Figure 9.6: Construction of the Geographic Distribution of Downlink Traffic Power The resulting geographic distribution is formed by linearly joining the obtained results.
Figure 9.7: Geographic Distribution of Downlink Traffic Power The accuracy of the geographic distribution depends upon the value of the angular step. A radiation pattern created at a 1 step will be much more accurate than one created at 45 , for example. But, the latter will be computed 45 times faster than the first. The value of the Angular Step should be the best possible compromise between calculation speed and accuracy.
9.5.3 Modelling in Coverage Predictions The results of Monte Carlo simulations, including the smart antenna results, can be stored in the Cells and in the Cell Parameters per Timeslot tables, and can be used to carry out coverage predictions. The main results of Monte Carlo simulations used in coverage predictions are: •
If a smart antenna is used in both uplink and downlink: Geographic distribution of UL load X
•
UL –
DL –
and DL traffic power P Traffic
If a smart antenna is used in downlink only: DL –
Geographic distribution of DL traffic power P Traffic •
Without smart antenna: UL load X
UL
DL
and DL traffic power P Traffic
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The uplink load and the downlink traffic power at a given pixel are determined by calculating the angle of that pixel with respect to the transmitter azimuth, and reading the uplink load and downlink traffic power from the geographic distribution results. If an exact value for the angle is not available, the load and power are determined using linear interpolation for the given angle between two available values. For example, the figure below shows the distribution of downlink traffic power and uplink traffic load results from a DL – 315
simulation. For a pixel located at = 315 , the downlink traffic power P Traffic DL – 315
from these results. In this example, P Traffic
30 dBm , and X
UL – 315
and the uplink load X
UL – 315
are read
= 2.75 % .
For each pixel, Atoll determines the downlink traffic powers and the uplink loads from all the transmitters.
Figure 9.8: Geographic Distribution of downlink traffic power and uplink load
9.5.4 HSDPA Quality and Throughput Analysis Fast link adaptation (or Adaptive Modulation and Coding) is used in HSDPA. The power on the HS-DSCH channel is transmitted at a constant power while the modulation, the coding, and the number of codes are changed to adapt to the radio conditions variations. Based on the reported channel quality indicator (CQI), the Node-B may change the modulation (QPSK and optionally 16QAM), the coding, and the number of codes every 2 ms during a communication. Fast link adaptation is modelled in a dedicated HSDPA coverage prediction. Let us assume each bin on the map corresponds to a probe receiver with HSDPA capable terminal, mobility, and HSDPA service. The probe receiver on each bin is allocated the cell’s HSDPA. This receiver may be using a specific carrier or all of them. The probe receiver does not create any interference. Atoll calculates on each bin either the best pilot quality (P-CCPCH Ec/Nt) or the best HS-PDSCH quality (HS-PDSCH Ec/Nt); this depends on the option selected in Global parameters (HSDPA part): CQI based on P-CCPCH quality or CQI based on HS-PDSCH quality (CQI means channel quality indicator). Then, it determines the HS-PDSCH CQI, deduces the best HSDPA bearer that can be used and selects the suitable bearer so as to comply with cell and terminal user equipment capabilities. Once the bearer selected, Atoll finds the highest downlink throughput that can be carried at each bin and may deduce the application throughput. Coverage area is limited by the RSCP P-CCPCH threshold. The coverage prediction can be calculated for an HSDPA compatible terminal, an HSDPA service, a mobility, a carrier, and a downlink timeslot. Smart antenna results are taken into account in the computation of this study.
9.5.4.1 Fast Link Adaptation Modelling As explained above, the way of calculating the dedicated HSDPA study depends on if CQI is based on the P-CCPCH quality or on the HS-PDSCH quality.
9.5.4.1.1
CQI Based on P-CCPCH Quality When the option “CQI based on CPICH quality” is selected, Atoll proceeds as follows. P-CCPCH Quality Calculation Ec Let us assume the following notation: ------ ic corresponds to the P-CCPCH quality. Nt P – CCPCH Two options, available in Global Parameters, may be used to calculate Nt: option Without useful signal or option Total noise. Therefore, we have:
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BTS RSCP P – CCPCH ic Ec ---- - for the total noise option, Nt ic P – CCPCH = -------------------------------------------------------------------DL N Tot ic And TXi
BTS RSCP P – CCPCH ic Ec ---- ic = ------------------------------------------------------------------------------------------------------------ for the without useful signal option. Nt P – CCPCH DL TXi N Tot ic – 1 – BTS RSCP P – CCPCH ic With DL
DL
DL
DL
Term
N Tot ic = I Intra ic + I Extra ic + I Inter – Carrier ic jc + N 0 DL
I Inter – Carrier ic jc is the inter-carrier interference from a carrier jc to another carrier ic on the downlink, which is reduced by the interference reduction factor F IRF ic jc defined for the pair (ic, jc). P P – CCPCH ic TXi RSCP P – CCPCH ic = ------------------------------LT CI
L Path L TX L Term L Body L Indoor M Shadowing L T = ---------------------------------------------------------------------------------------------------------------------G TX G Term Term
BTS , and N 0
are defined in "Definitions and Formulas" on page 595.
P-CCPCH CQI Determination Let us assume the following notation: CQI P – CCPCH corresponds to the P-CCPCH CQI. CQIP – CCPCH is deduced from the table Ec . This table is defined for the terminal reception equipment and the specified mobility. CQIP – CCPCH = f ------ ic Nt P – CCPCH HS-PDSCH Quality Calculation Atoll proceeds as follows: 1st step: Atoll calculates the HS-PDSCH power ( P HS – PDSCH ). P HSDPA ic is the power available for HSDPA on the carrier ic. This parameter is a user-defined cell input. P HSDPA ic = P HS – PDSCH ic + n HS – SCCH P HS – SCCH ic Therefore, we have: P HS – PDSCH ic = P HSDPA ic – n HS – SCCH P HS – SCCH ic n HS – SCCH is the number of HS-SCCH channels and P HS – SCCH ic is the HS-SCCH power on carrier ic. It is either fixed by the Req Ec user. P HS – SCCH ic is controlled so as to reach the required HS-SCCH Ec/Nt ( ------ ic ). It is specified in mobility Nt HS – SCCH
properties. We have: TXi
BTS RSCP HS – SCCH ic Ec ---- ic = ---------------------------------------------------------- for the total noise option, Nt HS – SCCH DL N Tot ic And TXi
BTS RSCP HS – SCCH ic Ec ---- ic = -------------------------------------------------------------------------------------------------------------------------------------------------------- for the without useful signal option. Nt HS – SCCH DL DL Term TXi N Tot ic – 1 – F Ortho 1 – F JD BTS RSCP HS – SCCH ic With DL
DL
DL
DL
Term
N Tot ic = I Intra ic + I Extra ic + I Inter – Carrier ic jc + N 0 DL
I Inter – Carrier ic jc is the inter-carrier interference from a carrier jc to another carrier ic on the downlink, which is reduced by the interference reduction factor F IRF ic jc defined for the pair (ic, jc).
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P HS – SCCH ic TXi RSCP HS – SCCH ic = ------------------------------LT and CI
L Path L TX L Term L Body L Indoor M Shadowing L T = ---------------------------------------------------------------------------------------------------------------------G TX G Term Term
BTS , F Ortho , F JD
Term
and N 0
are defined in "Definitions and Formulas" on page 595.
Therefore, Req
EcDL ---- ic N Tot ic HS – SCCH Nt TXi RSCP HS – SCCH ic = ------------------------------------------------------------------- L T for the total noise option, BTS And Req
EcDL ---- ic N Tot ic Nt HS – SCCH TXi RSCP HS – SCCH ic = ------------------------------------------------------------------------------------------------------------------------------------------- L T for the without useful signal option. Req Ec 1 + 1 – F DL 1 – F Term ---- ic Ortho JD BTS Nt HS – SCCH 2nd step: Then, Atoll calculates the HS-PDSCH quality Ec Let us assume the following notation: ------ ic corresponds to the HS-PDSCH quality. Nt HS – PDSCH Therefore, we have: TXi
BTS RSCP HS – PDSCH ic Ec ---- = ------------------------------------------------------------- for the total noise option, Nt ic HS – PDSCH DL N Tot ic And TXi
BTS RSCP HS – PDSCH ic Ec ----= ----------------------------------------------------------------------------------------------------------------------------------------------------------- for the without useful signal option. ic Nt HS – PDSCH TXi RSCP HS – PDSCH ic DL DL Term N Tot ic – 1 – F Ortho 1 – F JD BTS --------------------------------------------n Here, Atoll works on the assumption that five HS-PDSCH channels are used (n=5). With DL
DL
DL
DL
Term
N Tot ic = I Intra ic + I Extra ic + I Inter – Carrier ic jc + N 0 DL
I Inter – Carrier ic jc is the inter-carrier interference from a carrier jc to another carrier ic on the downlink, which is reduced by the interference reduction factor F IRF ic jc defined for the pair (ic, jc). P HS – PDSCH ic TXi RSCP HS – PDSCH ic = ---------------------------------LT And CI
L Path L TX L Term L Body L Indoor M Shadowing L T = ---------------------------------------------------------------------------------------------------------------------G TX G Term Term
BTS , F Ortho , F JD
Term
and N 0
are defined in "Definitions and Formulas" on page 595.
HS-PDSCH CQI Determination The best bearer that can be used depends on the HS-PDSCH CQI. Let us assume the following notation: CQI HS – PDSCH corresponds to the HS-PDSCH CQI. Atoll deduces CQI HS – PDSCH as follows: CQI HS – PDSCH = CQI P – CCPCH – P P – CCPCH + P HS – PDSCH
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Bearer Selection Knowing the HS-PDSCH CQI, Atoll finds the best bearer that can be used in the table Best Bearer=f(HS-PDSCH CQI). This table is defined for the terminal reception equipment and the specified mobility. Then, Atoll checks if best bearer characteristics are compliant with cell and user equipment category capabilities. Atoll selects the bearer which is the best bearer compliant with the cell and UE category capabilities. Bearer characteristics are provided in the HSDPA Bearer table. Assuming the best bearer = 23. Characteristics of this bearer are: • • • •
Transport block size: 9719 Bytes Number of HS-PDSCH channels used: 7 16QAM modulation used: Yes Peak Throughput: 4.48 Mb/s
Figure 9.9: Radio Bearers Table Assuming user equipment category = 3. Its capabilities are: • • • •
Maximum transport block size: 7298 Bytes Maximum number of HS-PDSCH channels used: 5 16QAM modulation used: Yes Minimum number of TTI between two TTI used: 2
Figure 9.10: UE Categories Table HSDPA cell capabilities are: •
Maximum number of HS-PDSCH channels: 15.
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The bearer 23 cannot be selected because: • •
The number of HS-PDSCH channels (7) exceeds the maximum number of HS-PDSCH channels the terminal can use (5), And the transport block size (9719 Bytes) exceeds the maximum transport block size (7298 Bytes) the terminal can carried.
In the Bearer table, Atoll searches a suitable bearer and selects the bearer index 22. • • •
The number of HS-PDSCH channels (5) does not exceed the maximum number of HS-PDSCH channels the terminal can use (5) and the maximum number of HS-PDSCH channels available at the cell level (15), The transport block size (7168 Bytes) does not exceed the maximum transport block size (7298 Bytes) the terminal can carried. 16QAM modulation is supported by the terminal.
HS-PDSCH Quality Update Once the bearer selected, Atoll knows the number of HS-PDSCH channels. Therefore, when the method “Without useful signal” is used, Atoll can recalculate the HS-PDSCH quality with the real number of HS-PDSCH channels (A default value of 5 was taken into account in the first HS-PDSCH quality calculation).
9.5.4.1.2
CQI Based on HS-PDSCH Quality When the option “CQI based on HS-PDSCH quality” is selected, Atoll proceeds as follows. HS-PDSCH Quality Calculation Atoll proceeds as follows: 1st step: Atoll calculates the HS-PDSCH power ( P HS – PDSCH ). P HSDPA ic is the power available for HSDPA on the carrier ic. This parameter is a user-defined cell input. P HSDPA ic = P HS – PDSCH ic + n HS – SCCH P HS – SCCH ic Therefore, we have: P HS – PDSCH ic = P HSDPA ic – n HS – SCCH P HS – SCCH ic n HS – SCCH is the number of HS-SCCH channels and P HS – SCCH ic is the HS-SCCH power on carrier ic fixed by the user. The HSReq Ec SCCH power is controlled so as to reach the required HS-SCCH Ec/Nt ( ------ ic ) specified in mobility properties. Nt HS – SCCH
We have: TXi
BTS RSCP HS – SCCH ic Ec ---- - for the total noise option, Nt ic HS – SCCH = ---------------------------------------------------------DL N Tot ic And TXi
BTS RSCP HS – SCCH ic Ec ---- = -------------------------------------------------------------------------------------------------------------------------------------------------------- for the without useful signal option. Nt ic HS – SCCH DL DL Term TXi N Tot ic – 1 – F Ortho 1 – F JD BTS RSCP HS – SCCH ic With DL
DL
DL
DL
Term
N Tot ic = I Intra ic + I Extra ic + I Inter – Carrier ic jc + N 0 DL
I Inter – Carrier ic jc is the inter-carrier interference from a carrier jc to another carrier ic on the downlink, which is reduced by the interference reduction factor F IRF ic jc defined for the pair (ic, jc). P HS – SCCH ic TXi RSCP HS – SCCH ic = ------------------------------LT i
And CI
L Path L TX L Term L Body L Indoor M Shadowing L T = ---------------------------------------------------------------------------------------------------------------------G TX G Term Term
BTS , F Ortho , F JD Therefore,
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Term
and N 0
are defined in "Definitions and Formulas" on page 595.
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Req EcDL ---- ic HS – SCCH N Tot ic Nt P HS – SCCH ic = ------------------------------------------------------------------- L T for the total noise option, BTS
And Req
EcDL ---- Nt ic HS – SCCH N Tot ic P HS – SCCH ic = ------------------------------------------------------------------------------------------------------------------------------------------- L T for the without useful signal option. Req Ec 1 + 1 – F DL 1 – F Term ---- ic Ortho JD BTS Nt HS – SCCH 2nd step: Then, Atoll evaluates the HS-PDSCH quality Ec Let us assume the following notation: ------ ic corresponds to the HS-PDSCH quality. Nt HS – PDSCH Two options, available in Global parameters, may be used to calculate Nt: option Without useful signal or option Total noise. We have: TXi
BTS RSCP HS – PDSCH ic Ec ---- = ------------------------------------------------------------- for the total noise option, Nt ic HS – PDSCH DL N Tot ic And TXi
BTS RSCP HS – PDSCH ic Ec ----= ----------------------------------------------------------------------------------------------------------------------------------------------------------- for the without useful signal option. ic Nt HS – PDSCH TXi RSCP HS – PDSCH ic DL DL Term N Tot ic – 1 – F Ortho 1 – F JD BTS --------------------------------------------n Here, Atoll works on the assumption that five HS-PDSCH channels are used (n=5). Then, it deduces the HS-PDSCH CQI and the bearer to be used. Once the bearer selected, Atoll exactly knows the number of HS-PDSCH channels and recalculates the HSPDSCH quality with the real number of HS-PDSCH channels. With DL
DL
DL
DL
Term
N Tot ic = I Intra ic + I Extra ic + I Inter – Carrier ic jc + N 0 DL
I Inter – Carrier ic jc is the inter-carrier interference from a carrier jc to another carrier ic on the downlink, which is reduced by the interference reduction factor F IRF ic jc defined for the pair (ic, jc). P HS – PDSCH ic TXi RSCP HS – PDSCH ic = ---------------------------------LT And CI
L Path L TX L Term L Body L Indoor M Shadowing L T = ---------------------------------------------------------------------------------------------------------------------G TX G Term Term
BTS , F Ortho , F JD
Term
and N 0
are defined in "Definitions and Formulas" on page 595.
HS-PDSCH CQI Determination Let us assume the following notation: CQIHS – PDSCH corresponds to the HS-PDSCH CQI. CQI HS – PDSCH is deduced from the Ec . This table is defined for the terminal reception equipment and the specified table CQI HS – PDSCH = f ------ ic Nt HS – PDSCH mobility. Bearer Selection The bearer is selected as described in "Bearer Selection" on page 646.
9.5.4.2 Coverage Prediction Display Options Three display options are available in the study property dialogue.
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Colour per CQI Atoll displays either the P-CCPCH CQI when the selected option in Global Parameters (HSDPA part) is CQI based on P-CCPCH quality, or the HS-PDSCH CQI when considering the CQI based on HS-PDSCH quality option. Coverage consists of several layers with a layer per CQI threshold ( CQI Threshold ). For each layer, area is covered if CQI CQI Threshold . Each layer is assigned a colour and displayed with intersections between layers.
9.5.4.2.2
Colour per Peak Throughput After selecting the bearer, Atoll reads the corresponding RLC peak throughput. This is the highest throughput that the bearer can provide on each bin. DL
Coverage consists of several layers with a layer per possible peak throughput ( R Peak ). For each layer, area is covered if the peak throughput can be provided. Each layer is assigned a colour and displayed with intersections between layers.
9.5.4.2.3
Colour per HS-PDSCH Ec/Nt Atoll displays on each bin the HS-PDSCH quality. Coverage consists of several layers with a layer per threshold. For each layer, Ec Threshold . Each layer is assigned a colour and displayed with intersections between area is covered if ------ ic Nt HS – PDSCH layers.
9.6 N-Frequency Mode and Carrier Allocation Transmitters that support N-frequency mode are multi carrier transmitters with a master and one or more slave carrier. You can assign master and slave carriers to transmitters manually, or use the automatic frequency allocation in Atoll to assign carrier types automatically.
9.6.1 Automatic Carrier Allocation For each transmitter, Atoll determines a list of "near" transmitters. For any transmitter TXi, its "near" transmitters are geographically located close to the transmitter, and are sorted according to their distance from it. The calculation of distance between TXi and any other transmitter TXj is performed using the equation below: D
TX i – TX j
Where D
= d
TX i – TX j
TX i – TX j
1 + x cos – cos – 2
is the weighted distance between TXi and TXj, d
TX i – TX j
is the real distance between between TXi and TXj
considering any offsets with respect to the site locations, x is set to 15 % so that the maximum variation in D
TX i – TX j
due to
the azimuths does not exceed 60 %. and are calculated from the azimuths of the two cells as shown in Figure 9.11 on page 650.
Figure 9.11: Weighted Distance Between Transmitters The above formula implies that two transmitters facing each other will have a shorter weighted distance between them than the real distance, and two transmitters pointing in opposite directions will have a greater weighted distance.
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Allocation of All Carriers Co-N-Frequency Allocation
Diff-N-Frequency Allocation
Atoll assigns the same carriers to cells of each co-site transmitter.
Atoll assigns different carriers to cells of each co-site transmitter.
Allocation of Master Carriers Atoll assigns one master carrier to each transmitter TXi, such that the master carrier of TXi is different from the master carrier of TXj, where TXj belongs to the list of "near" transmitters. The master carrier is one of the cells defined in the transmitter. All the other cells of the transmitter are assigned the carrier-type "slave". For transmitters that support the N-frequency mode and have master carriers properly assigned, Atoll performs the neighbour and scrambling code allocation for the master carrier only.
9.7 Neighbour Allocation Atoll permits the automatic allocation of intra-technology neighbours in a TD-SCDMA document. The intra-technology neighbour allocation algorithms take into account all the cells of TBC transmitters. It means that all the cells of TBC transmitters of your .atl document are potential neighbours. The cells to be allocated will be called TBA cells. They must fulfill the following conditions: • • • • •
They are active Their transmitters support the N-frequency mode, and the cells are master carriers of their transmitters (neighbours are not allocated to standalone carriers) They satisfy the filter criteria applied to the Transmitters folder They are located inside the focus zone They belong to the folder on which allocation has been executed. This folder can be either the Transmitters folder or a group of transmitters or a single transmitter.
Only TBA cells may be assigned neighbours. If no focus zone exists in the .atl document, Atoll takes into account the computation zone.
In this section, the following are explained: • • •
"Neighbour Allocation for All Transmitters" on page 651. "Neighbour Allocation for a Group of Transmitters or One Transmitter" on page 655. "Importance Calculation" on page 655.
9.7.1 Neighbour Allocation for All Transmitters We assume that we have a reference cell A and a candidate neighbour, cell B. When automatic allocation starts, Atoll checks following conditions: 1. The distance between both cells must be less than the user-defined maximum inter-site distance. If the distance between the reference cell and the candidate neighbour is greater than this value, the candidate neighbour is discarded. Atoll calculates the effective distance, which corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Appendix: Calculation of the InterTransmitter Distance" on page 656. 2. The calculation options:
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Force co-site cells as neighbours: This option enables you to force cells located on the same site as reference cell in the candidate neighbour list. This constraint can be weighted among the others and ranks the neighbours through the importance field. Force adjacent cells as neighbours: This option enables you to force cells geographically adjacent to the reference cell in the candidate neighbour list. This constraint can be weighted among the others and ranks the neighbours through the importance field. •
Adjacency criterion: Geographically adjacent cells are determined on the basis of their best server coverages in TD-SCDMA projects. Let CellA be a candidate neighbour cell of CellB. CellA is considered adjacent to CellB if there exists at least one pixel in the CellB best server coverage area (and P-CCPCH RSCP of CellB > P-CCPCH RSCP T_Add) where CellA is best server (of several cells have the same best server value) or CellA is the second best server that enters the handover set (i.e., P-CCPCH RSCP of CellA > P-CCPCH RSCP T_Drop and P-CCPCH RSCP of CellA > P-CCPCH RSCP of CellB T_Comp.)
•
When this option is selected, adjacent cells are sorted and listed from the most adjacent to the least, depending on the above criterion. Adjacency is relative to the number of pixels satisfying the criterion.
Force symmetry: This option enables you to force the reciprocity of a neighbourhood link. Therefore, if the reference cell is a candidate neighbour of another cell, the later will be considered as candidate neighbour of the reference cell. If the neighbours list of a transmitter is full, the reference transmitter will not be added as a neighbour of that transmitter and that transmitter will be removed from the reference transmitter’s neighbours list. You can force Atoll to keep that transmitter in the reference transmitter’s neighbours list by adding the following option in the Atoll.ini file: [Neighbours] DoNotDeleteSymmetrics = 1
• •
Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may force/forbid a cell to be candidate neighbour of the reference cell. Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, the existing neighbours are kept.
3. If the Use Coverage Conditions check box is selected, there must be an overlapping zone ( S A S B ) with a given cell edge coverage probability. Otherwise, only the distance criterion is taken into account. The overlapping zone ( S A S B ) is defined as follows: N-frequency handover is a baton handover. Assuming that the reference cell A and the candidate cell B are located inside a continuous layer of cells: SA is the area where the cell A is the best serving cell. • •
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The P-CCPCH RSCP from the cell A is greater than the P-CCPCH RSCP T_Add. The P-CCPCH RSCP from the cell A is greater than the P-CCPCH RSCP from all other cells.
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SB is the area where the cell B can enter the handover set. • •
The P-CCPCH RSCP from the cell B is greater than the P-CCPCH RSCP T_Drop. The P-CCPCH RSCP from the cell B is greater than the P-CCPCH RSCP from the cell A minus the P-CCPCH RSCP T_Comp.
Figure 9.12: N-frequency Neighbour Allocation SA SB - 100 ), which it compares with the % minimum covered Atoll calculates the percentage of covered area ( ----------------SA area. If this percentage is not exceeded, the candidate neighbour B is discarded. The coverage condition can be weighted among the others and ranks the neighbours through the importance field.
: Overlapping Coverages 4. The importance of neighbours. For information on the importance calculation, see "Importance Calculation" on page 655.
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Importance values are used by the allocation algorithm to rank the neighbours according to the allocation reason. Atoll lists all neighbours and sorts them by importance value so as to eliminate some of them from the neighbour list if the maximum number of neighbours to be allocated to each transmitter is exceeded. If we consider the case for which there are 15 candidate neighbours and the maximum number of neighbours to be allocated to the reference cell is 8. Among these 15 candidate neighbours, only 8 (having the highest importance values) will be allocated to the reference cell. Note that maximum numbers of neighbours can be defined at the cell level (properties dialogue or Cells table). If defined there, this value is taken into account instead of the default one available in the dialogue. In the Results part, Atoll provides the list of neighbours, the number of neighbours, and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason, i.e., a neighbour may be marked as exceptional pair, co-site, adjacent, coverage, or symmetric. For neighbours accepted for co-site, adjacency, and coverage reasons, Atoll displays the percentage of area that satisfies the coverage conditions and the corresponding surface area (km2), the percentage of area that satisfies the adjacency conditions and the corresponding surface area (km2). Finally, if cells have previous allocations in the list, neighbours are marked as existing. •
By default, the automatic neighbour allocation compares the defined Max intersite distance with the effective inter-transmitter distance. As a consequence, there can be cases where the real distance between assigned neighbours is higher than the Max inter-site distance, because the effective distance is smaller. You can force Atoll to compare the Max inter-site distance with the real inter-site distance by adding the following lines in Atoll.ini: [Neighbours] RealInterSiteDistanceCondition=1
•
By default, the neighbour importance calculated with respect to distance is based on the global Max inter-site distance setting for all neighbour candidates. As a consequence, there can be cases where the calculated importance is different when the global Max inter-site distance is modified. To avoid that, you can force Atoll to prioritise the individual distances between reference transmitters and their respective neighbour candidates by adding the following lines in Atoll.ini: [Neighbours] CandidatesMaxDistanceInImportanceCalculation=1
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•
•
You do not require simulations or coverage predictions for an automatic neighbour allocation. For automatic neighbour allocation, Atoll automatically calculates the missing path loss matrices. Although no specific terminal, mobility, or service is selected for automatic neighbour allocation, the algorithm tries to find the maximum number of neighbours by selecting: • •
•
•
The service with the lowest body loss The terminal with the highest difference between Gain and Losses. If this is the same for all terminals, Atoll uses the terminal with the lowest noise figure. • Mobility does not impact the allocation A forbidden neighbour must not be listed as neighbour except if the neighbourhood relationship already exists and the Delete existing neighbours option is not selected. In this case, Atoll displays a warning message in the Event Viewer indicating that the constraint on the forbidden neighbour will be ignored by the algorithm because the neighbour already exists. Symmetric neighbour relations are only added to the neighbour lists if the neighbour lists are not already full. Thus, if the cell B is a neighbour of the cell A, but cell A is not a neighbour of the cell B, there can be two possibilities: 1. There is space in the cell B neighbour list: cell A will be added to the list. It will be the last one. 2. The cell B neighbour list is full: Atoll will not include cell A in the list and will remove the symmetric relation by deleting cell B from the cell A neighbour list.
•
•
If you select Force exceptional pairs and Force symmetry options, Atoll considers the constraints between exceptional pairs in both directions so as to respect the symmetric relation. On the other hand, if a neighbour relation is forced in one direction and forbidden in the other, symmetry cannot be respected. In this case, Atoll displays a warning message in the Event Viewer. In the results, Atoll displays only the cells for which it finds new neighbours. Therefore, if a TBA cell has already reached its maximum number of neighbours before starting the new allocation, it will not appear in the Results table.
9.7.2 Neighbour Allocation for a Group of Transmitters or One Transmitter In this case, Atoll allocates neighbours to: • • •
TBA cells Neighbours of TBA cells marked as exceptional pair, adjacent, or symmetric Neighbours of TBA cells that satisfy coverage conditions
Automatic neighbour allocation parameters are described in "Neighbour Allocation for All Transmitters" on page 651.
9.7.3 Importance Calculation Importance values are used by the allocation algorithm to rank the neighbours according to the allocation reason and the distance, and to quantify the neighbour importance. The neighbour importance depends on the distance from the reference transmitter and on the neighbourhood cause (cf. table below); this value varies between 0 and 100%. Neighbourhood cause
When
Importance value
Existing neighbour
Only if the Delete existing neighbours option is not selected and in case of a new allocation
Existing importance
Exceptional pair
Only if the Force exceptional pairs option is selected
100 %
Co-site cell
Only if the Force co-site cells as neighbours option is selected
Importance Function (IF)
Adjacent cell
Only if the Force adjacent cells as neighbours option is selected
Importance Function (IF)
Neighbourhood relationship that fulfils coverage conditions
Only if the % minimum covered area is exceeded
Importance Function (IF)
Symmetric neighbourhood relationship
Only if the Force neighbour symmetry option is selected
Importance Function (IF)
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Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined using the Importance Function (IF). The IF considers the following factors for calculating the importance: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Appendix: Calculation of the Inter-Transmitter Distance" on page 656. d max is the maximum distance between the reference transmitter and a possible neighbour.
• • •
The co-site factor (C): a Boolean, The adjacency factor (A): the percentage of adjacency, The overlapping factor (O): the percentage of overlapping.
The minimum and maximum importance assigned to each of the above factors can be defined. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
30%
Adjacency factor (A)
Min(A)
30%
Max(A)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The Importance Function is evaluated as follows: Neighbourhood cause
Importance Function
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%Max(Di))(O)}+Min(Di)+Delta(Di)(Di)
10%+20%{10%(Di)+90%(O)}+1%+9%(Di)
No
Yes
Min(A)+Delta(A){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
30%+30%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Yes
Yes
Min(C)+Delta(C){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
60%+40%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Co-site
Adjacent
No
Where: Delta(X)=Max(X)-Min(X) • •
•
•
Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours, adjacent neighbours, and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes. The default value of Min(O) = 1% ensures that neighbours selected for symmetry will have an importance greater than 0%. With a value of Min(O) = 0%, neighbours selected for symmetry will have an importance field greater than 0% only if there is some coverage overlapping.
9.7.4 Appendix: Calculation of the Inter-Transmitter Distance Atoll takes into account the real distance ( D in m) and azimuths of antennas in order to calculate the effective intertransmitter distance ( d in m). d = D 1 + x cos – x cos where x = 0.3% so that the maximum D variation does not exceed 1%.
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Figure 9.13: Inter-Transmitter Distance Computation The formula above implies that two cells facing each other will have a smaller effective distance than the real physical distance. It is this effective distance that will be taken into account rather than the real distance.
9.8 Scrambling Code Allocation Downlink scrambling codes enable mobile to distinguish one cell from another. In TD-SCDMA, there are 128 scrambling codes (or P-CCPCH midamble codes) distributed in 32 clusters of 4 codes each. A different DL synchronisation code, or SYNC_DL code, is assigned to each cluster. Scrambling codes are numbered from 0 to 127, and SYNC_DL codes from 0 to 31. Depending on the options you select for automatic allocation of scrambling and SYNC_DL codes, Atoll takes into account either all the cells of TBC transmitters, or only cells of active and filtered transmitters located inside the computation zone. Atoll calculates a scrambling code and a SYNC_DL code to all these cells. But, it allocates scrambling codes and SYNC_DL codes only to TBA cells (cells to be allocated). TBA cells are the cells that fulfill the following conditions: • • • •
They are active They satisfy the filter criteria applied to the Transmitters folder They are located inside the focus zone They belong to the folder on which allocation has been executed. This folder can be either the Transmitters folder or a group of transmitters or a single transmitter.
Furthermore, if there are transmitters that support the N-frequency mode among the TBC transmitters of your network, the scrambling code allocation also considers the master and slave carrier allocations. If no focus zone exists in the .atl document, Atoll takes into account the computation zone.
9.8.1 Automatic Allocation Description 9.8.1.1 Allocation Constraints and Options The scrambling code and SYNC_DL code allocation algorithm can take into account following constraints: 1. Neighbour relations between cells You may consider: • • •
First order neighbours: The neighbours of TBA cells listed in the Intra-technology neighbours table, Second order neighbours: The neighbours of neighbours, Third order neighbours: The neighbour’s neighbour’s neighbours. •
•
Atoll can take into account inter-technology neighbour relations as constraints to allocate different scrambling codes to the TD-SCDMA neighbours of a GSM transmitter. In order to consider inter-technology neighbour relations in the scrambling code allocation, you must make the Transmitters folder of the GSM.atl document accessible in the TD-SCDMA.atl document. For information on making links between GSM and TD-SCDMA .atl documents, see the User Manual. Atoll considers symmetry relationship between a cell, its first order neighbours, its second order neighbours and its third order neighbours.
2. The scrambling code reuse distance
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Reuse Distance: It is a constraint on the allocation of scrambling codes. The same scarmbling code or SYNC_DL code cannot be allocated to two sites that are not farther apart than the reuse distance. Scrambling code reuse distance can be defined for each cell in the cell properties. If this value is not defined, Atoll uses the default reuse distance defined in the Automatic Scrambling Code and SYNC_DL code Allocation dialogue. The reuse distance constraint is used for clustered and distributed per cell allocation strategies. 3. The carrier for which you want to perform the automatic allocation Carrier: You can select "All" or a specific carrier. If you select "All", Atoll allocates the same scrambling code to each carrier of a transmitter. 4. The number of scrambling codes per SYNC_DL code Each SYNC_DL code corresponds to a group of scrambling codes as defined in 3GPP specifications. 3GPP specifications define 32 SYNC_DL codes with 4 corresponding scrambling codes each (SYNC_DL codes are numbered from 0 to 31). However, it is possible to define a different value (e.g. if you set the number of scrambling codes per SYNC_DL codes to 2, scrambling codes will be distributed among 64 SYNC_DL codes). When the allocation is based on a Distributed strategy (Distributed per Cell or Distributed per Site), this parameter can also be used to define the interval between the scrambling codes assigned to cells on a same site. The defined interval is applied by adding the following lines in the Atoll.ini file: [PSC] ConstantStep=1 For more information about setting options in the atoll.ini file, see the Administrator Manual. 5. Atoll can use a maximum of codes Use a Maximum of Codes: If you choose to use a maximum of codes, Atoll will try to spread the allocated spectrum of scrambling codes as much as possible. 6. Existing allocation Delete All Codes: If you select this option, Atoll will delete any existing scrambling code allocation and perform a fresh allocation. Otherwise, Atoll keeps the existing allocation.
9.8.1.2 Allocation Strategies You can choose from the following four allocation strategies: • • •
Clustered: The purpose of this strategy is to choose for a group of mutually constrained cells, scrambling codes among a minimum number of clusters. In this case, Atoll will preferentially allocate all the codes within the same cluster. Distributed per Cell: This strategy consists in using as many clusters as possible. Atoll will preferentially allocate codes from different clusters. One SYNC_DL code per site: This strategy allocates one cluster, i.e., one SYNC_DL code, per site, then one scrambling code from the cluster to each cell of the site. When all the clusters have been allocated but there are still sites remaining, Atoll reuses the clusters as far as possible at another site. Same carriers must be assigned different scrambling codes. Different carriers of the same site can be assigned the same scrambling code. Therefore, cells of a transmitter (i.e. different carriers) are assigned the same scrambling code, if the scrambling code domains associated with the carriers have a common cluster or enough codes in one cluster.
•
Distributed per site: This strategy allocates a group of adjacent clusters, i.e., consecutive SYNC_DL codes, to each site, then one cluster, or SYNC_DL code, to each transmitter on the site according to its azimuth, and finally one scrambling code from each cluster to each cell of each transmitter. The number of adjacent clusters, or consecutive SYNC_DL codes, depends on the number of transmitters per site. When all the sites have been allocated adjacent clusters, and there are still sites remaining to be allocated, Atoll reuses the adjacent clusters as far as possible at another site.
In the Results table, Atoll only displays scrambling codes and SYNC_DL codes allocated to TBA cells.
9.8.1.3 Allocation Process For each TBA cell, Atoll lists all cells which have constraints with the cell. They are referred to as near cells. The near cells of a TBA cell may be: • •
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• • •
The third order neighbours (options “Existing neighbours” and “Third Order”), The cells with distance from the TBA cell less than the reuse distance, The cells that make exceptional pairs with the TBA cell.
Additional constraints are considered when: • •
The cell and its near cells are neighbours of a same GSM transmitter (only if the Transmitters folder of the GSM.atl document is accessible in the TD-SCDMA.atl document), The neighbour cells cannot share the same cluster (for the "Distributed per site" allocation strategy only).
These constraints have a certain weight taken into account to determine the TBA cell priority during the allocation process and the cost of the scrambling code plan. During the allocation, Atoll tries to assign different scrambling codes to the TBA cell and its near cells. If it respects all the constraints, the cost of the scrambling code plan is 0. When a cell has too many constraints and there are not anymore scrambling codes available, Atoll breaks the constraint with the lowest cost so as to generate the scrambling code plan with the lowest cost. For information on the cost generated by each constraint, see "Cell Priority" on page 660.
9.8.1.3.1
Single Carrier Network The allocation process depends on the selected strategy. Algorithm works as follows: Strategies: Clustered and Distributed per Cell Atoll processes TBA cells according to their priority. It allocates scrambling codes starting with the highest priority cell and its near cells, and continuing with the lowest priority cells not allocated yet and their near cells. For information on calculating cell priority, see "Cell Priority" on page 660. Strategy: One SYNC_DL Code per Site All sites which have constraints with the studied site are referred to as near sites. Atoll assigns a cluster, i.e., a SYNC_DL code, to each site, starting with the highest priority site and its near sites, and continuing with the lowest priority sites not allocated yet and their near sites. When all the clusters have been allocated but there are still sites remaining, Atoll reuses the clusters at the other sites. When the Reuse Distance option is selected, the algorithm reuses the clusters as soon as the reuse distance is exceeded. Otherwise, when the option is not selected, the algorithm tries to assign reused clusters as spaced out as possible. Then, Atoll allocates a scrambling code from the cluster to each cell located on the sites (codes belong to the assigned clusters). It starts with the highest priority cell and its near cells and goes on with the lowest priority cells not allocated yet and their near cells. For information on calculating site priority, see "Site Priority" on page 663. For information on calculating cell priority, see "Cell Priority" on page 660. Strategy: Distributed per Site All sites which have constraints with the studied site are referred to as near sites. Atoll assigns a group of adjacent clusters, i.e., SYNC_DL codes, to each site, starting with the highest priority site and its near sites, and continuing with the lowest priority sites not allocated yet and their near sites. When all the sites have been allocated adjacent clusters, and there are still sites remaining to be allocated, Atoll reuses the adjacent clusters at other sites. When the Reuse Distance option is selected, the algorithm reuses the clusters as soon as the reuse distance is exceeded. Otherwise, when the option is not selected, the algorithm tries to assign reused clusters as spaced out as possible. Then, Atoll assigns each cluster of the group to each transmitter of the site according to the transmitter azimuth and selected neighbourhood constraints (options "Neighbours in Other Clusters" and "Secondary Neighbours in Other Clusters"). Then, Atoll allocates a scrambling code to each cell located on the transmitters (codes belong to the assigned clusters). It starts with the highest priority cell and its near cells and goes on with the lowest priority cells not allocated yet and their near cells. For information on calculating site priority, see "Site Priority" on page 663. or information on calculating cell priority, see "Cell Priority" on page 660. Determination of Groups of Adjacent Clusters In order to determine the groups of adjacent clusters to be used, Atoll: • • • •
Defines theoretical groups of adjacent clusters, independent of the defined domain, considering the 128 scrambling codes available and 4 codes per cluster. Starts the distribution of clusters to groups from the cluster 0 Takes into account the maximum number of transmitters per site in order to determine the number of clusters in each group Determines the total number of groups
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If the number of scrambling codes per cluster is set to 4 and the maximum number of transmitters per site in the network is 3, the theoretical groups of adjacent clusters will be: Group 1
Group 2
Group 3
Group 4
Cluster 0
Cluster 3
Cluster 6
Cluster 9
Cluster 1
Cluster 4
Cluster 7
Cluster 10
Cluster 2
Cluster 5
Cluster 8
Cluster 11
...
Group 11 Cluster 30
...
Cluster 31
If no domain is assigned to cells, Atoll can use all these groups for the allocation. On the other hand, if a domain is used, Atoll compares adjacent clusters actually available in the assigned domain with the theoretical groups and only keeps adjacent clusters common with the theoretical groups. If we have a domain comprising 12 clusters: clusters 1 to 8 and clusters 12 to 15. In this case, Atoll will use the following groups of adjacent clusters: • • •
Group 2 with cluster 3, 4 and 5 Group 3 with cluster 6, 7 and 8 Group 6 with cluster 12, 13 and 14
The clusters 1, 2 and 15 will not be used. If a domain does not contain any adjacent clusters, Atoll displays a warning message in the Event Viewer.
9.8.1.3.2
Multi-Carrier Network In case you have a multi-carrier network and you run the scrambling code allocation on all the carriers, the allocation order changes. It is no longer based on the cell priority but depends on the transmitter priority. All transmitters which have constraints with the studied transmitter will be referred to as near transmitters. In case of a "Per cell" strategy (Clustered and Distributed per cell), Atoll starts scrambling code allocation with the highest priority transmitter and its near transmitters and continues with the lowest priority transmitters not allocated yet and their near transmitters. The same scrambling code is assigned to each cell of the transmitter. In case of the "One SYNC_DL code per site" strategy, Atoll assigns a cluster, i.e., a SYNC_DL code, to each site and then, allocates a scrambling code to each transmitter. It starts with the highest priority transmitter and its near transmitters and continues with the lowest priority transmitters not allocated yet and their near transmitters. The same scrambling code is assigned to each cell of the transmitter. In case of the "Distributed per site" strategy, Atoll assigns a group of adjacent clusters, i.e., SYNC_DL codes, to each site, then a cluster to each transmitter and finally, allocates a scrambling code to each transmitter. It starts with the highest priority transmitter and its near transmitters and continues with the lowest priority transmitters not allocated yet and their near transmitters. The same scrambling code is assigned to each cell of the transmitter. For information on calculating transmitter priority, see "Transmitter Priority" on page 662. When cells, transmitters or sites have the same priority, processing is based on an alphanumeric order.
9.8.1.4 Priority Determination 9.8.1.4.1
Cell Priority Scrambling code allocation algorithm in Atoll allots priorities to cells before performing the actual allocation. Priorities assigned to cells depend upon how much constrained each cell is and the cost defined for each constraint. A cell without any constraint has a default cost, C , equal to 0. The higher the cost on a cell, the higher the priority it has for the scrambling code allocation process. There are seven criteria employed to determine the cell priority. The total cost due to constraints on any cell i is defined as: C i = C i Dom + C i U With C i U = C i Dist + C i EP + C i N + C i N 2G + C i Cluster + C i CN All the cost components are described below: •
Scrambling Code Domain Criterion
The cost due to the domain constraint, C i Dom , depends on the number of scrambling codes available for the allocation. The domain constraint is mandatory and cannot be broken.
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When no domain is assigned to cells, 128 scrambling codes are available and we have: C i Dom = 0 When domains of scrambling codes are assigned to cells, each unavailable scrambling code generates a cost. The higher the number of codes available in the domain, the less will be the cost due to this criterion. The cost is given as: C i Dom = 128 – Number of scrambling codes in the domain •
Distance Criterion
The constraint level of any cell i depends on the number of cells (j) present within a radius of "reuse distance" from its centre. The total cost due to the distance constraint is given as:
Cj Dist i
C i Dist =
j
Each cell j within the reuse distance generates a cost given as: C j Dist i = w d ij c dis tan ce Where w d ij is a weight depending on the distance between i and j. This weight is inversely proportional to the inter-cell distance. For a reuse distance of 2000m, the weight for an inter-cell distance of 1500m is 0.25, the weight for co-site cells is 1 and the weight for two cells spaced out 2100m apart is 0. c dis tan ce is the cost of the distance constraint. This value can be defined in the Constraint Cost dialogue. •
Exceptional Pair Criterion
The constraint level of any cell i depends on the number of exceptional pairs (j) for that cell. The total cost due to exceptional pair constraint is given as: C i EP =
cEP i – j j
Where c EP is the cost of the exceptional pair constraint. This value can be defined in the Constraint Cost dialogue. •
Neighbourhood Criterion
The constraint level of any cell i depends on the number of its neighbour cells j, the number of second order neighbours k and the number of third order neighbours l. Let’s consider the following neighbour schema:
Figure 9.14: Neighbourhood Constraints The total cost due to the neighbour constraint is given as: Ci N =
Cj N1 i + Cj – j N1 i + Ck N2 i + Ck – k N2 i + Cl N3 i + Cl – l N3 i j
j
k
k
l
l
Each first order neighbour cell j generates a cost given as: C j N1 i = I j c N1 Where I j is the importance of the neighbour cell j. c N1 is the cost of the first order neighbour constraint. This value can be defined in the Constraint Cost dialogue.
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Because two first order neighbours must not have the same scrambling code, Atoll considers the cost created by two first order neighbours to be each other. C j N1 i + C j N1 i C j – j N1 i = ----------------------------------------------------2 Each second order neighbour cell k generates a cost given as: C k N2 i = Max ( C j N1 i C k N1 j , C j N1 i C k N1 j ) c N2 Where c N2 is the cost of the second order neighbour constraint. This value can be defined in the Constraint Cost dialogue. Because two second order neighbours must not have the same scrambling code, Atoll considers the cost created by two second order neighbours to be each other. C k N2 i + C k N2 i C k – k N2 i = ------------------------------------------------------2 Each third order neighbour cell l generates a cost given as: C N1 i C k N1 j C l N1 k C j N1 i C k N1 j C l N1 k C l N3 i = Max j c N3 C j N1 i C k N1 j C l N1 k C j N1 i C k N1 j C l N1 k Where c N3 is the cost of the third order neighbour constraint. This value can be defined in the Constraint Cost dialogue. Because two third order neighbours must not have the same scrambling code, Atoll considers the cost created by two third order neighbours to be each other. C l N3 i + C l N3 i C l – l N3 i = ----------------------------------------------------2 Atoll considers the highest cost of both links when a neighbour relation is symmetric and the importance value is different.
In this case, we have: C j N1 i = Max I i – j I j – i c N1 And C k N2 i = Max (C j N1 i C k N1 j ,C j N1 k C i N1 j ) c N2 •
Close Neighbour Criterion
The constraint level of any cell i depends on the number of its close neighbour cells j. The close neighbour cost ( C i CN ) depends on two components: the importance of the neighbour relation ( I i – j ) and the distance ( d i – j ) relative to maximum Max
close neighbour distance ( d CN ).
C i CN =
j
di – j I + 1 – ---------- i–j Max d CN ----------------------------------------- c CN 2
Where c CN is the cost of the close neighbour constraint. This value can be defined in the Constraint Cost dialogue. •
GSM Neighbour Criterion
This criterion is considered when the co-planning mode is activated (i.e. the Transmitters folder of the GSM .atl document is made accessible in the TD-SCDMA.atl document) and inter-technology neighbours have been allocated. If the cell i is neighbour of a GSM transmitter, the cell constraint level depends on how many cells j are neighbours of the same GSM transmitter. The total cost due to GSM neighbour constraint is given as:
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C i N 2G =
cN2G j – Tx2G j
Where cN
2G
is the cost of the GSM neighbour constraint. This value can be defined in the Constraint Cost dialogue.
•
Cluster Criterion
When the "Distributed per Site" allocation strategy is used, you can consider additional constraints on allocated clusters (one cell, its first order neighbours and its second order neighbours must be assigned scrambling codes from different clusters). In this case, the constraint level of any cell i depends on the number of first and second order neighbours, j and k. The total cost due to the cluster constraint is given as: C i Cluster =
Cj N1 i cCluster + Ck N2 i cCluster j
k
Where c Cluster is the cost of the cluster constraint. This value can be defined in the Constraint Cost dialogue.
9.8.1.4.2
Transmitter Priority In case you have a multi-carrier network and you run scrambling code allocation on "all" the carriers, Atoll allots priorities to transmitters. Priorities assigned to transmitters depend on how much constrained each transmitter is and the cost defined for each constraint. The higher the cost on a transmitter, the higher the priority it has for the scrambling code allocation process. Let us consider a transmitter Tx with two cells using carriers 0 and 1. The cost due to constraints on the transmitter is given as: C Tx = C Tx Dom + C Tx U With C Tx U =
Max C U and C Dom = 128 – Number of scrambling codes in the domain Tx i Tx i
Here, the domain available for the transmitter is the intersection of domains assigned to cells of the transmitter. The domain constraint is mandatory and cannot be broken.
9.8.1.4.3
Site Priority In case of "Per Site" allocation strategies (One SYNC_DL code per Site and Distributed per Site), Atoll allots priorities to sites. Priorities assigned to sites depend on how much constrained each site is and the cost defined for each constraint. The higher the cost on a site, the higher the priority it has for the scrambling code allocation process. Let us consider a site S with three transmitters; each of them has two cells using carriers 0 and 1. The cost due to constraints on the site is given as: C S = C S U + C S Dom With C S U =
Max C U and C Dom = 128 – Number of scrambling codes in the domain S Tx S Tx
Here, the domain considered for the site is the intersection of domains available for transmitters of the site. The domain constraint is mandatory and cannot be broken.
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9.8.2 Scrambling Code Allocation Example 9.8.2.1 Single Carrier Network In order to understand the differences between the different allocation strategies and the behaviour of algorithm when using a maximum of codes or not, let us consider the following sample scenario:
Figure 9.15: Scrambling Code Allocation Example Let Site0, Site1, Site2, and Site3 be four sites, with 3 transmitters each using carrier 0, to whom scrambling codes have to be allocated out of 6 clusters of 4 scrambling codes. This implies that the domain of scrambling codes for the four sites is from 0 to 23 (cluster 0 to cluster 5). The reuse distance is supposed to be less than the inter-site distance. Only co-site neighbours exist. The following section shows the results of each combination of options with explanations where necessary.
9.8.2.1.1
Strategy: Clustered Since the restrictions of neighbourhood only apply to co-sites and, in our case, the distances between sites are greater than the reuse distance, every cell has the same priority. Allocation is performed in an alphanumeric order. Without "Use a Maximum of Code"
With "Use a Maximum of Code"
As it is possible to use a maximum of codes, Atoll starts allocation at the start of a different cluster at each site. Atoll starts allocating the codes from the start of cluster 0 at When a cluster is reused, and there are non allocated codes each site. left in the cluster, Atoll first allocates those codes before reusing the already used ones.
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9.8.2.1.2
Strategy: Distributed per Cell Since the restrictions of neighbourhood only apply to co-sites and, in our case, the distances between sites are greater than the reuse distance, every cell has the same priority. Allocation is performed in an alphanumeric order.
9.8.2.1.3
Without "Use a Maximum of Code"
With "Use a Maximum of Code"
Atoll allocates codes from different clusters to each cell of the same site. Under given constraints of neighbourhood and reuse distance, same codes can be allocated to each site’s cells.
Atoll allocates codes from different clusters to each site’s cells. As it is possible to use a maximum of codes, Atoll allocates the codes so that there is least repetition of codes.
Strategy: One SYNC_DL Code per Site Since the restrictions of neighbourhood only apply to co-sites, therefore, every site has the same priority. Cluster allocation to sites is performed in an alphanumeric order. Without "Use a Maximum of Code"
With "Use a Maximum of Code"
In this strategy, a cluster of codes is limited to be used at just one site at a time unless all codes and clusters have been allocated and there are still sites remaining to be allocated. In this case, Atoll reuses the cluster as far as possible at another site.
When it is possible to use a maximum of codes, Atoll can allocate different codes from a reused cluster at another site.
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Strategy: Distributed per Site Since the restrictions of neighbourhood only apply to co-sites, therefore, every site has the same priority. Cluster allocation to sites is performed in an alphanumeric order. Without "Use a Maximum of Code"
With "Use a Maximum of Code"
A group of adjacent clusters is allocated to one site at a time, unless all the codes and groups of adjacent clusters have been allocated but there are still sites remaining to be allocated. In this case (here only one group of adjacent clusters 0, 1, and 2 is available), Atoll reuses the group as far as possible at another site.
When it is possible to use a maximum of codes, Atoll can allocate different codes from a reused groups of adjacent clusters at another site.
9.8.2.2 Multi Carrier Network If you have a multi carrier network, i.e., transmitters with more than one cells using different carriers, and you run scrambling code allocation on "all" the carriers, Atoll allocates the same scrambling code to each carrier of a transmitter. Let Site0, Site1, Site2, and Site3 be four sites with 3 cells using carrier 0 and 3 cells using carrier 1. Scrambling codes have to be allocated out of 6 clusters consisted of 4 scrambling codes. This implies that the domain of scrambling codes for the four sites is from 0 to 23 (cluster 0 to cluster 5). The reuse distance is supposed to be less than the inter-site distance. Only co-site neighbours exist. Every site has the same priority and the cluster allocation to sites is performed in an alphanumeric order. Atoll allocates one cluster at each site and then, one code to each transmitter. Then, the same code is given to each cell of the transmitter.
Figure 9.16: Scrambling Code Allocation to All Carriers
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9.9 Automatic GSM/TD-SCDMA Neighbour Allocation It is possible to automatically calculate and allocate neighbours between GSM and TD-SCDMA networks. In Atoll, it is called inter-technology neighbour allocation. Inter-technology handover is used in two cases: • •
When the TD-SCDMA coverage is not continuous. In this case, the TD-SCDMA coverage is extended by TD-SCDMA to GSM handovers. In order to balance traffic and service distribution between both networks.
Atoll’s automatic inter-technology neighbour allocation algorithm takes into account both cases. In order to be able to use the inter-technology neighbour allocation algorithm, you must have: • •
An .atl document containing the GSM network, GSM.atl, and another one containing the TD-SCDMA network, TDSCDMA.atl, An existing link on the Transmitters folder of GSM.atl into TD-SCDMA.atl.
The external neighbour allocation algorithm takes into account all the GSM TBC transmitters. It means that all the TBC transmitters of GSM.atl are potential neighbours. The TD-SCDMA cells, in TD-SCDMA.atl, to be allocated neighbours are called TBA cells which fulfill following conditions: • • • •
They are active They satisfy the filter criteria applied to Transmitters folder They are located inside the focus zone They belong to the folder for which allocation has been executed. This folder can be either the Transmitters folder or one of its subfolders.
Only TD-SCDMA TBA cells can be assigned neighbours.
9.9.1 Automatic Allocation Description The allocation algorithm takes into account criteria listed below: • • • •
The inter-transmitter distance The maximum number of neighbours Allocation options The selected allocation strategy
Two allocation strategies are available: the first one is based on distance and the second one on coverage overlapping. We assume we have a TD-SCDMA reference cell, A, and a GSM candidate neighbour transmitter, B.
9.9.1.1 Algorithm Based on Distance When automatic allocation starts, Atoll checks following conditions: 1. The distance between the TD-SCDMA reference cell and the GSM neighbour must be less than the user-defined maximum inter-site distance. If the distance between the TD-SCDMA reference cell and the GSM neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance, which corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Appendix: Calculation of the InterTransmitter Distance" on page 656. 2. The calculation options: Carriers: This option enables you to select the carrier(s) on which you want to run the allocation. You may choose one or more carriers. Atoll will allocate neighbours to cells using the selected carriers. Force co-site cells as neighbours: It enables you to automatically include GSM transmitters located on the same site than the reference TD-SCDMA cell in the candidate neighbour list. This option is automatically selected. Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may force/forbid a GSM transmitter to be candidate neighbour of the reference TD-SCDMA cell. Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, existing neighbours are kept. 3. The importance of neighbours. Next, Atoll calculates the importance of the automatically allocated neighbours. Atoll sorts the neighbours by decreasing importance in order to keep the ones with high importance. If the maximum number of neighbours to be allocated to each cell is exceeded, Atoll keeps the ones with high importance.
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As indicated in the table below, the neighbour importance depends on the distance and on the neighbourhood cause; this value varies between 0 to 100%. Neighbourhood cause
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter
If the Force co-site cells as neighbours option is selected
100 %
Neighbourhood relationship that fulfils distance conditions
If the maximum distance is not exceeded
d1 – ---------d max
Where d is the effective distance between the TD-SCDMA reference cell and the GSM neighbour and d max is the maximum inter-site distance. In the Results part, Atoll provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason. Therefore, a neighbour may be marked as exceptional pair, co-site, or distance. For neighbours accepted for distance reasons, Atoll displays the distance from the reference cell (m). Finally, if cells have previous allocations in the list, neighbours are marked as existing.
9.9.1.2 Algorithm Based on Coverage Overlapping When automatic allocation starts, Atoll checks following conditions: 1. The distance between the TD-SCDMA reference cell and the GSM neighbour must be less than the user-defined maximum inter-site distance. If the distance between the TD-SCDMA reference cell and the GSM neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance, which corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Appendix: Calculation of the InterTransmitter Distance" on page 656. 2. The calculation options: Carriers: This option enables you to select the carrier(s) on which you want to run the allocation. You may choose one or more carriers. Atoll will allocate neighbours to cells using the selected carriers. Force co-site cells as neighbours: It enables you to automatically include GSM transmitters located on the same site than the reference TD-SCDMA cell in the candidate neighbour list. This option is automatically selected. Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may force/forbid a GSM transmitter to be candidate neighbour of the reference TD-SCDMA cell. Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, existing neighbours are kept. 3. There must be an overlapping zone ( S A S B ) with a given cell edge coverage probability. Two different cases may be considered for SA: •
1st case: SA is the area where the cell A is the best serving cell of the TD-SCDMA network. • The pilot signal received from A is greater than the minimum pilot signal level and is the highest one. • The margin is set to 0 dB.
•
2nd case: The margin is different from 0 dB and SA is the area where: • The pilot signal level received from A exceeds the user-defined minimum pilot signal level and is within a margin from the highest signal level.
Two different cases may be considered for SB: •
1st case: SB is the area where the cell B is the best serving transmitter of the GSM network. In this case, the margin must be set to 0 dB. •
•
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The signal level received from B on the BCCH TRX type exceeds the user-defined minimum threshold and is the highest one.
2nd case: The margin is different from 0 dB and SB is the area where: • The signal level received from B on the BCCH TRX type exceeds the user-defined minimum threshold and is within a margin from the best BCCH signal level.
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SA SB - 100 ) and compares this value to the % minimum covered Atoll calculates the percentage of covered area ( ----------------SA area. If this percentage is less than the minimum, the candidate neighbour B is discarded. Candidate neighbours fulfilling coverage conditions are sorted in descending order with respect to percentage of covered area. 4. The importance of neighbours. Next, Atoll calculates the importance of the automatically allocated neighbours. Atoll sorts the neighbours by decreasing importance in order to keep the ones with high importance. If the maximum number of neighbours to be allocated to each cell is exceeded, Atoll keeps the ones with high importance. As indicated in the table below, the neighbour importance depends on the distance and on the neighbourhood cause; this value varies between 0 to 100%. Neighbourhood reason
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter
If the Force co-site cells as neighbours option is selected
IF
Neighbourhood relationship that fulfils coverage conditions
If the % minimum covered area is exceeded
IF
Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined using the Importance Function (IF). The IF considers the following factors for calculating the importance: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. For information on the effective distance calculation, see "Appendix: Calculation of the Inter-Transmitter Distance" on page 656. d max is the maximum distance between the reference transmitter and a possible neighbour.
• •
The co-site factor (C): a Boolean, The overlapping factor (O): the percentage of overlapping.
The IF is user-definable using the Min importance and Max importance fields. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The IF evaluates importance as follows: Co-site Neighbourhood cause
IF
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%-Max(Di))(O)}
10%+50%{10%(Di)+90%(O)}
Yes
Min(C)+Delta(C){Max(Di)(Di)/(Max(Di)+Max(O))+ Max(O)(O)/(Max(Di)+Max(O))}
60%+40%{1/7%(Di)+6/7%(O)}
Where Delta(X)=Max(X)-Min(X)
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•
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Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes.
In the Results part, Atoll provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason. Therefore, a neighbour may be marked as exceptional pair, co-site or coverage. For neighbours accepted for co-site and coverage reasons, Atoll displays the percentage of area meeting the coverage conditions and the corresponding surface area (km2). Finally, if cells have previous allocations in the list, neighbours are marked as existing. •
•
•
No prediction study is needed to perform an automatic neighbour allocation. When starting an automatic neighbour allocation, Atoll automatically calculates the path loss matrices if not found. A forbidden neighbour must not be listed as neighbour except if the neighbourhood relationship already exists and the Delete existing neighbours option is unchecked when you start the new allocation. In this case, Atoll displays a warning in the Event viewer indicating that the constraint on the forbidden neighbour will be ignored by algorithm because the neighbour already exists. In the Results, Atoll displays only the cells for which it finds new neighbours. Therefore, if a TBA cell has already reached its maximum number of neighbours before starting the new allocation, it will not appear in the Results table.
9.9.1.3 Appendices 9.9.1.3.1
Delete Existing Neighbours Option As explained above, Atoll keeps the existing inter-technology neighbours when the Delete existing neighbours option is not selected. If a new TBA cell i is created in TD-SCDMA.atl, you can run the automatic allocation with the Delete existing neighbours option not selected, in order to allocate neighbours to the new cell i only. If you change some allocation criteria (e.g., increase the maximum number of neighbours or create a new GSM TBC transmitter) and start a new allocation without selecting the Delete existing neighbours option, Atoll examines the neighbour list of the TBA cells and checks allocation criteria only if there is still space left in their neighbour lists. A new GSM TBC transmitter can enter the TBA cell neighbour list if allocation criteria are satisfied. It will be the first one in the neighbour list.
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Chapter 10 WiMAX BWA Networks This chapter covers the following topics: •
"Definitions" on page 673
•
"Calculation Quick Reference" on page 678
•
"Available Calculations" on page 690
•
"Calculation Details" on page 702
•
"Automatic Planning Algorithms" on page 758
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10 WiMAX BWA Networks This chapter describes all the calculations performed in Atoll WiMAX documents. The first part of this chapter lists all the input parameters in the WiMAX BWA documents, their significance, location in the Atoll GUI, and their usage. It also contains the lists of the formulas used for the calculations. The second part describes all the calculation processes, i.e., signal level coverage predictions, point analysis calculations, signal quality coverage predictions, calculations on subscriber lists, and Monte Carlo simulations. The calculation algorithms used by these calculation processes are available in the next part. The third part describes all the calculation algorithms used in all the calculations. These algorithms include the calculation of signal levels, noise, and interference for downlink and uplink considering the effects of smart antennas, power control, subchannelisation, MIMO etc., and the radio resource management algorithms used by the different available schedulers. If you are new to WiMAX, you can also see the Glossary of WiMAX Terms in the User Manual for information on WiMAX terms and concepts, especially in the context of their user in Atoll. • • •
All the calculations are performed on TBC (to be calculated) transmitters. For the definition of TBC transmitters please refer to "Path Loss Matrices" on page 103. A cell refers to a transmitter-carrier (TX-c) pair. The cell being studied during a calculation is referred to as TXi(ic) in this chapter. All the calculation algorithms in this section are described for two types of cells. •
•
A studied cell (represented by the subscript "i") comprising the studied transmitter TXi and its carrier ic. It is the cell which is currently the focus of the calculation. For example, a victim cell when calculating the interference it is receiving from other cells. • Other cells (represented by the subscript "j") comprising the other transmitter TXj and its carrier jc. The other cells in the network can be interfering cells (downlink) or the serving cells of interfering mobiles (uplink). All the calculation algorithms in this section are described for two types of receivers.
•
Mi: A pixel (coverage predictions), subscriber (calculations on subscriber lists), or mobile (Monte Carlo simulations) covered/served by the studied cell TXi(ic). • Mj: A mobile (Monte Carlo simulations) covered/served by any other cell TXj(jc). Logarithms used in this chapter (Log function) are base-10 unless stated otherwise. •
10.1 Definitions This table lists the input to calculations, coverage predictions, and simulations. Name
Value
Unit
Description
K
1.38 x 10-23
J/K
Boltzmann’s constant
T
290
K
Ambient temperature
n0
Calculation result ( 10 Log K T 1000 = – 174 dBm/Hz )
dBm/Hz
Power spectral density of thermal noise
D Frame
Global parameter
ms
Frame Duration Choice List: 2, 2.5, 4, 5, 8, 10, 12.5, 20
r CP
Frame configuration or, otherwise, global parameter
None
Cyclic Prefix Ratio Choice List: 1/4, 1/8, 1/16, 1/32
O Fixed
DL
Global parameter
SD
Fixed time-domain overhead (DL)
O Fixed
UL
Global parameter
SD
Fixed time-domain overhead (UL)
DL
Global parameter
%
Variable time-domain overhead (DL)
UL
Global parameter
%
Variable time-domain overhead (UL)
TDD
Global parameter
%
Ratio of the DL subframe to the entire frame (TDD only)
O Variable O Variable r DL-Frame
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Name
Value
Unit
Description
N SD – DL
TDD
Global parameter
None
Number of symbol durations per frame that corresponds to the DL subframe (TDD only)
TDD
Global parameter
None
Number of symbol durations per frame that corresponds to the UL subframe (TDD only)
D TTG
TDD
Global parameter
ms
Transmit Time Guard (TDD only)
D RTG
TDD
Global parameter
ms
Receive Time Guard (TDD only)
M PC
Global parameter
dB
Uplink power control margin
CNR Min
Global parametera
dB
Minimum signal to thermal noise threshold (interferer cutoff)
PZ
Permutation zone parameter
None
Number of subchannels per channel in UL subframe
N SC – DL
PZ
Permutation zone parameter
None
Number of subchannels per channel in DL subframe
N SCa – Total
Frame configuration parameter
None
Total number of subcarriers per channel (FFT size)
N SCa – Preamble
Frame configuration parameter
None
Number of subcarriers used by the preamble
PZ
Permutation zone parameter
None
Number of used subcarriers per channel
N SCa – Data
PZ
Permutation zone parameter
None
Number of subcarriers per channel used for data transfer
N SCa – DC
Hard-coded parameter ( N SCa – DC = 1 )
None
Number of DC subcarriers per channel
None
Number of pilot subcarriers per channel
None
Number of guard subcarriers per channel
N SD – UL
N SC – UL
N SCa – Used
PZ
N SCa – Pilot
PZ
PZ
PZ
Calculation result ( N SCa – Pilot = N SCa – Used – N SCa – Data ) Calculation result
PZ
N SCa – Guard
PZ ( N SCa – Guard
PZ
= N SCa – Total – N SCa – Used – N SCa – DC )
PZ UL
Permutation zone parameter
None
Uplink permutation zone
PZ DL
Permutation zone parameter
None
Downlink permutation zone
QT PZ
Permutation zone parameter
dB
Quality threshold: Required preamble C/N or C/(I+N) for accessing a zone
Speed Max – PZ
Permutation zone parameter
Km/hr
Speed limit for mobiles trying to access a permutation zone
d Max – PZ
Permutation zone parameter
m
Maximum distance from the transmitter covered by a zone
p PZ
Permutation zone parameter
None
Permutation zone priority
W Channel
Frequency band parameter
MHz
Channel bandwidth
First
Frequency band parameter
None
First channel number of the frequency band
N Channel
Last
Frequency band parameter
None
Last channel number of the frequency band
F Start – FB – TDD
Frequency band parameter
MHz
Start frequency of the TDD frequency band
F Start – FB – FDD – DL
Frequency band parameter
MHz
DL Start frequency of the FDD frequency band
F Start – FB – FDD – UL
Frequency band parameter
MHz
UL Start frequency of the FDD frequency band
N Channel
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Name
Value
Unit
Description
f Sampling
Frequency band parameter
None
Sampling factor
f ACS – FB
Frequency band parameter
dB
Adjacent Channel Suppression Factor
ICS FB
Frequency band parameter
MHz
Inter-channel spacing
CN FB
Frequency band parameter
None
Channel number step
Inter – Tech
Network parameter
dB
Inter-technology interference reduction factor
B
Bearer parameter
None
Bearer index
Mod B
Bearer parameter
None
Modulation used by the bearer
CR B
Bearer parameter
None
Coding rate of the bearer
B
Bearer parameter
bits/ symbol
Bearer Efficiency
TB
Bearer parameter
dB
Bearer selection threshold
TP BH – DL
Site
Site parameter
kbps
Maximum backhaul site downlink throughput
Site
Site parameter
kbps
Maximum backhaul site uplink throughput
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
dB
Transmitter noise figure
N Ant – TX
Transmitter parameter
None
Number of antennas used for MIMO in transmission
N Ant – RX
Transmitter parameter
None
Number of antennas used for MIMO in reception
TX
Antenna parameter
dB
Transmitter antenna gain
TX
Transmitter parameter (user-defined or calculated from transmitter equipment characteristics)
dB
Transmitter loss
TX
Smart antenna parameter
None
Number of smart antenna elements
Array
Smart antenna parameter
dB
Array gain offset
Combining
Smart antenna parameter
dB
Power combining gain offset
G SA
Smart antenna parameter
dB
Diversity gain (cross-polarisation)
N Channel
Cell parameter
None
Cell’s channel number
P Preamble
Cell parameter
dBm
Preamble power
dB
Traffic power reduction
dB
Pilot power reduction
dB
Idle pilot power reduction
f IRF
TP BH – UL nf
G L
TX
E SA G SA G SA
Div
Cell parameter P Traffic = P Preamble – P Traffic in dB P Traffic Ratio P Traffic
= 10
P Traffic ------------------------10
in %
Cell parameter P Pilot = P Preamble – P Pilot in dB P Pilot Ratio P Pilot
= 10
P Pilot -------------------10
in %
Cell parameter P Idle – Pilot = P Preamble – P Idle – Pilot in dB P Idle – Pilot Ratio P Idle – Pilot
= 10
P Idle – Pilot -----------------------------------10
in %
TL DL
Cell parameter
%
Downlink traffic load
TL UL
Cell parameter
%
Uplink traffic load
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Name
Value
Unit
Description
TL DL – Max
Cell parameter
%
Maximum downlink traffic load
TL UL – Max
Cell parameter
%
Maximum uplink traffic load
NR UL
Cell parameter
dB
Uplink noise rise
NRUL – Seg
Cell parameter
dB
Segmented zone uplink noise rise
N Users – Max
Cell parameter
None
Maximum number of users per cell
N Users – DL
Cell parameter
None
Number of users connected to the cell in downlink
N Users – UL
Cell parameter
None
Number of users connected to the cell in uplink
SU DL
Cell parameter
%
Downlink segmentation usage ratio
AU DL
Cell parameter
%
Downlink AAS usage ratio
T AMS
Cell parameter
dB
Adaptive MIMO switch threshold
T MU – MIMO
Cell parameter
dB
Multi-user MIMO threshold
PI
Cell parameter
None
Preamble index
T Preamble
Cell parameter
dB
Preamble C/N threshold
D Reuse
Cell parameter
m
Channel and preamble index reuse distance
G MU – MIMO
Cell parameter
None
Uplink MU-MIMO gain
Inter – Tech
Cell parameter
dB
Inter-technology downlink noise rise
Inter – Tech
Cell parameter
dB
Inter-technology uplink noise rise
ZPBDL
Cell parameter
None
Downlink zone permbase
ZPB UL
Cell parameter
None
Uplink zone permbase
TX i ic
Proportional Fair scheduler parameter
None
Downlink multi-user diversity gain (MUG)
TX i ic
Proportional Fair scheduler parameter
None
Uplink multi-user diversity gain (MUG)
Proportional Fair scheduler parameter
dB
Maximum C/(I+N) above which no MUG gain is applied
G SU – MIMO
Max
Cell WiMAX equipment parameter
None
Maximum SU-MIMO gain
G Div – UL
Cell WiMAX equipment parameter
dB
Uplink STTD/MRC, SU-MIMO or MUMIMO diversity gain
f Bias
QoS
Scheduler parameter
%
QoS class bias factor
QoS
Service parameter
None
QoS class of the service
p
Service parameter
None
Service priority
B DL – Highest
Service parameter
None
Highest bearer used by a service in the downlink
B UL – Highest
Service parameter
None
Highest bearer used by a service in the uplink
B DL – Lowest
Service parameter
None
Lowest bearer used by a service in the downlink
B UL – Lowest
Service parameter
None
Lowest bearer used by a service in the uplink
UL
Service parameter
%
Uplink activity factor
NR DL
NR UL
G MUG – DL G MUG – UL Max
CINR MUG
f Act
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Name
Value
Unit
Description
f Act
DL
Service parameter
%
Downlink activity factor
TPD Min – UL
Service parameter
kbps
Minimum throughput demand in the uplink
TPD Min – DL
Service parameter
kbps
Minimum throughput demand in the downlink
TPD Max – UL
Service parameter
kbps
Maximum throughput demand in the uplink
TPD Max – DL
Service parameter
kbps
Maximum throughput demand in the downlink
UL
Service parameter
kbps
Average requested throughput in the uplink
TP Average
DL
Service parameter
kbps
Average requested throughput in the downlink
TP Offset
Service parameter
kbps
Throughput offset
f TP – Scaling
Service parameter
%
Scaling factor
L Body
Service parameter
dB
Body loss
N SC – UL
Min
Service parameter
None
Minimum number of subchannels
P Min
Terminal parameter
dBm
Minimum terminal power allowed
P Max
Terminal parameter
dBm
Maximum terminal power allowed
nf
Terminal parameter
dB
Terminal noise figure
G
Terminal parameter
dB
Terminal antenna gain
L
Terminal parameter
dB
Terminal loss
N Ant – TX
Terminal parameter
None
Number of antennas used for MIMO in transmission
N Ant – RX
Terminal parameter
None
Number of antennas used for MIMO in reception
G SU – MIMO
Max
Terminal WiMAX equipment parameter
None
Maximum SU-MIMO gain
G Div – DL
Terminal WiMAX equipment parameter
dB
Downlink STTD/MRC or SU-MIMO diversity gain
G Div – Preamble
Terminal WiMAX equipment parameter
dB
Preamble diversity gain
UL
Clutter parameter
dB
Additional uplink diversity gain
G Div
DL
Clutter parameter
dB
Additional downlink diversity gain
f SU – MIMO
Clutter parameter
None
SU-MIMO gain factor
L Indoor
Clutter parameter
dB
Indoor loss
L Path
Propagation model result
dB
Path loss
TP Average
G Div
ICP DL
Network parameter
None
Inter-technology downlink channel protection ratio for a frequency offset F between the interfered and interfering frequency channels
M Shadowing – Model
Monte Carlo simulations: Random result calculated from model standard deviation Coverage Predictions: Result calculated from cell edge coverage probability and model standard deviation
dB
Model shadowing margin
M Shadowing – C I
Coverage Predictions: Result calculated from cell edge coverage probability and C/I standard deviation
dB
C/I shadowing margin
F
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Any interfering cell whose signal to thermal noise ratio is less than CNR Min will be discarded.
10.2 Calculation Quick Reference The following tables list the formulas used in calculations.
10.2.1 Co- and Adjacent Channel Overlaps Calculation Name TX i ic
F Start
Value TX ic i
TX ic i
TX i ic
TX i ic
TX jc
TX i ic – TX j jc
TX ic
Description
MHz
Start frequency for the channel number assigned to a cell
MHz
End frequency for the channel number assigned to a cell
MHz
Co-channel overlap bandwidth
None
Co-channel overlap ratio
MHz
Bandwidth of the lower-frequency adjacent channel overlap
None
Lower-frequency adjacent channel overlap ratio
MHz
Bandwidth of the higher-frequency adjacent channel overlap
None
Higher-frequency adjacent channel overlap ratio
None
Adjacent channel overlap ratio
None
FDD – TDD overlap ratio
None
Total overlap ratio
TX i ic – TX j jc
r CCO
TX i ic – TX j jc
TX jc
TX ic
TX jc
TX ic
TX ic
j i j i i Min F End F Start – Max F Start F Start – W Channel
L
TX i ic – TX j jc
W ACO L ---------------------------------TX i ic W Channel
TX i ic – TX j jc L
TX i ic – TX j jc
TX j jc
TX i ic
Min F End F End
H
TX ic
TX jc
TX ic
i j i + W Channel – Max F Start F End TX i ic – TX j jc
W ACO H ---------------------------------TX ic i W Channel
TX i ic – TX j jc
r ACO
TX ic
W CCO ----------------------------------TX i ic W Channel
TX i ic – TX j jc
W ACO
TX jc
j i j i Min F End F End – Max F Start F Start
W CCO
r ACO
TX i ic
F Start + W Channel
F End
W ACO
N TXi ic – N First – TXi ic Channel Channel - ------------------------------------------------------TX i ic CN FB
TX ic i
F Start – FB + W Channel + ICS FB
Unit
H
TX i ic – TX j jc
TX i ic – TX j jc
r ACO
r ACO
L
TX i ic – TX j jc
+ r ACO
H
TDD
TX i ic – TX j jc
r FDD – TDD
r DL – Frame ----------------------- if interferer uses a TDD frequency band and victim uses 100 an FDD frequency band, 1 otherwise TX ic
i – f ACS – FB TX ic – TX jc TX ic – TX jc ---------------------------- TX ic – TX jc 10 j i j j r i r i + r ACO 10 FDD – TDD CCO TX i ic – TX j jc
rO
TX i ic
TX j jc
if W Channel W Channel TX ic
i – f ACS – FB TX ic TX ic – TX jc TX ic – TX jc --------------------------- TX ic – TX jc W i 10 j i j i j Channel r i --------------------+ r ACO 10 TX j jc CCO r FDD – TDD W Channel TX i ic
TX j jc
if W Channel W Channel
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10.2.2 Preamble Signal Level Calculation Name TX ic i C Preamble
Value
Unit
Description
dBm
Received preamble signal level
dBm
Preamble EIRP of a cell
dB
Path loss
dB
Total losses
Value
Unit
Description
TX i ic TX ic N SCa – Preamble Preamble i - f Segment n 0 + 10 Log F Sampling --------------------------------TX i ic N SCa – Total
dBm
Preamble thermal noise for a cell
1 --3
None
Preamble segmenting factor
dBm
Preamble noise for a cell
Unit
Description
dBm
Total interference generated by an interfering cell
dB
Interference reduction factor due to the co- and adjacent channel overlap
dB
Interference reduction factor due to segmentation
None
Preamble subcarrier collision probability
W
Downlink inter-technology interference
Unit
Description
dB
Preamble C/N for a cell
TX ic i
EIRP Preamble – L Path – M Shadowing – Model – L Indoor + G –L
Mi
Mi
– L Ant – L Body TX i ic
TX i ic
TX i
–L
TX i
With smart antennas: TX i ic
P Preamble + G
TX i
–L
TX i
TX i
+ 10 Log E SA + TX
L Path
L Total
i
Mi
Without smart antennas: P Preamble + G EIRP Preamble
M
Combining G SA
+
Div G SA
i
L Model + L Ant L Path + L Mi
TX i
+ L Indoor + M Shadowing – Model – G
TX i
+L
Mi
–G
Mi
Mi
+ L Ant + L Body
10.2.3 Preamble Noise Calculation Name TX i ic
n 0 – Preamble
Preamble
f Segment TX i ic
TX i ic
n 0 – Preamble + nf
n Preamble
Mi
10.2.4 Preamble Interference Calculation Name TX j jc
I Preamble
Value TX j jc
TX i ic – TX j jc
C Preamble + f O
TX i ic – TX j jc
TX ic – TX jc i j
TX i ic – TX j jc
10 Log r O
TX ic – TX jc i j
10 Log p Collision
fO
TX i ic – TX j jc
TX i ic – TX j jc
f Seg – Preamble p Collision
Inter – Tech
+ f Seg – Preamble + I DL
TX i ic
1 if N Seg
TX j jc
= N Seg
TX i ic
and 0 if N Seg
TX j jc
N Seg
TX k P DL – Rec -------------------------------------- F TX ic TX i k TX k ICP DL
Inter – Tech I DL
10.2.5 Preamble C/N Calculation Name TX i ic
CNR Preamble
Value TX i ic
TX i ic
Mi
DL
C Preamble – n Preamble + G Div – Preamble + G Div
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10.2.6 Preamble C/(I+N) Calculation Name
Value
Unit
Description
TX ic
TX i ic
CINR Preamble
i TXj jc n Preamble IPreamble ----------------------------- TX i ic Inter – Tech 10 ---------------------------- Inter – Tech C Preamble – 10 Log + 10 + NR DL 10 I 10 DL dB All TXj jc Preamble C/(I+N) for a cell
Mi
DL
+ G Div – Preamble + G Div TX ic
TX ic i
I + N Preamble
i TXj jc n Preamble IPreamble ----------------------------- Inter – Tech 10 -------------------------- +I + NR Inter – Tech dBm 10 Log + 10 10 DL 10 DL All TXj jc
Preamble Total Noise (I+N) for a cell
10.2.7 Traffic and Pilot Signal Level Calculation (DL) Name TX i ic
C Traffic
TX i ic
C Pilot
TX i ic
EIRP Traffic TX i ic
EIRP Pilot TX i ic
P Traffic TX i ic
P Pilot
Value TX i ic
EIRP Traffic – L Path – M Shadowing – Model – L Indoor + G Mi
–L
Mi
dBm
Received traffic signal level
dBm
Received pilot signal level
Mi
Mi
TX i ic
Mi
Description
– L Ant – L Body
EIRP Pilot – L Path – M Shadowing – Model – L Indoor + G –L
Unit
Mi
Mi
Mi
– L Ant – L Body
TX i ic
TX i
TX i ic
TX i
P Traffic + G P Pilot + G
Array
+ G SA
Array
+ G SA
+ G SA + G SA
Div
TX i
dBm
Traffic EIRP of a cell
Div
TX i
dBm
Pilot EIRP of a cell
Combining
+ G SA – L
Combining
+ G SA – L
TX i ic
TX i ic
dBm
Traffic transmission power of a cell
TX i ic
TX i ic
dBm
Pilot transmission power of a cell
P Preamble – P Traffic P Preamble – P Pilot
10.2.8 Traffic and Pilot Noise Calculation (DL) Name
Value
Unit
Description
dBm
Thermal noise for a cell
None
Downlink segmenting factor
dBm
Downlink noise for a cell
Mi
TX i ic
n 0 – DL
PZ DL N SCa – Used TXi ic n 0 + 10 Log F Sampling ------------------------ TX i ic N SCa – Total With Segmentation: Mi
PZ DL TXi ic N SCa – Used n 0 + 10 Log F Sampling ------------------------ f Segment – DL TX i ic N SCa – Total
f Segment – DL TX i ic
n DL
680
3 PSG + 2 SSG 1 without and --------------------------------------------- with downlink segmentation 15 TX i ic
n 0 – DL + nf
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10.2.9 Traffic and Pilot Interference Calculation (DL) Name
Value TX jc
Unit
Description
dBm
Total interference generated by an interfering cell
TX jc
j I j I Non – AAS Idle ---------------------------------------------- 10 10 Monte Carlo Simulations: 10 Log 10 + 10 TX jc
I j AAS -----------------10 without smart antennas, or 10 Log 10 with smart antennas
TX j jc
I Total
TX jc
TX jc
TX jc
j j I j I I Non – AAS Idle AAS ---------------------------------------------------------------- 10 10 10 Coverage Predictions: 10 Log 10 + 10 + 10
Monte Carlo Simulations: TX j jc
EIRP Traffic – L Path – M Shadowing – Model – L Indoor + G TX j jc
Mi
–L
Mi
Mi
Mi
– L Ant – L Body
Coverage Predictions:
I Traffic
dBm
TX j jc
Traffic interference power of an interfering cell
EIRP Traffic – L Path – M Shadowing – Model + M Shadowing – C I – L Indoor +G
Mi
–L
Mi
Mi
Mi
– L Ant – L Body Monte Carlo Simulations:
TX jc j EIRP Pilot
– L Path – M Shadowing – Model – L Indoor + G
TX j jc
M
i
–L
M
i
M
i
M
i
– L Ant – L Body dBm
Pilot interfering power of an interfering cell
TX j
dBm
Traffic EIRP of an interfering cell
TX j
dBm
Pilot EIRP of an interfering cell
dBm
Interference from the loaded part of the frame transmitted using the transmitter antenna of an interfering cell
Coverage Predictions:
I Pilot
TX jc j
EIRP Pilot – L Path – M Shadowing – Model + M Shadowing – C I – L Indoor +G
Mi
Mi
–L
Mi
Mi
– L Ant – L Body
TX j jc
TX j jc
TX j
TX j jc
TX j
P Traffic + G
EIRP Traffic TX j jc
P Pilot + G
EIRP Pilot
–L –L
TX jc
TX j jc
I Non – AAS
I j TX j jc Traffic ------------------ TX jc TX jc N SCa – Data 10 j j -+ 10 Log TL DL ----------------------- 1 – AU DL 10 TX j jc N SCa – Used
10
TX j jc I Pilot ------------------10
TX j jc N SCa – Data 1 – ------------------------- TX j jc N SCa – Used Monte Carlo Simulations:
TX j jc
– L Path – M Shadowing – Model – L Indoor + G
EIRP AAS TX j jc
TX j jc
EIRP AAS +G TX jc j
–L
Mi
Mi
Mi
–L
Mi
– L Ant – L Body
Coverage Predictions:
I AAS
EIRP AAS
Mi
dBm
Interference power of an interfering cell transmitted using smart antenna
dBm
Traffic EIRP of an interfering cell using smart antenna
– L Path – M Shadowing – Model + M Shadowing – C I – L Indoor
Mi
Mi
Mi
– L Ant – L Body TX jc j
P Traffic + G
TX
j
–L
TX
j
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Name
Value
TX jc j I Idle – Pilot
TX jc j EIRP Idle – Pilot
TX j jc
– L Path – L Indoor + G TX j jc
P Idle – Pilot + G
EIRP Idle – Pilot
TX j
M
i
–L
–L
M
i
–
M
i L Ant
–
M
i L Body
TX j
Unit
Description
dBm
Interference from empty part of the frame transmitted using the transmitter antenna of an interfering cell
dBm
Idle pilot EIRP of an interfering cell
dBm
Interference from the empty part of the frame transmitted using the transmitter antenna of an interfering cell
dB
Interference reduction factor due to the co- and adjacent channel overlap
TX jc
TX j jc
I Idle
I j TX j jc Idle – Pilot- ----------------------------TX jc N 10 j SCa – Data 10 Log 1 – TL DL 10 1 – ------------------------ TX j jc N SCa – Used TX ic – TX jc i j
TX i ic – TX j jc
10 Log r O
TX ic – TX jc i j
i j 10 Log p Collision – DL
dB
Interference reduction factor due to downlink segmentation
TX k P DL – Rec -------------------------------------- F TX i ic TX k TX k ICP DL
W
Downlink inter-technology interference
Unit
Description
dB
Traffic C/N for a cell
dB
Pilot C/N for a cell
fO
TX ic – TX jc
f Seg – DL
Inter – Tech I DL
10.2.10 Traffic and Pilot C/N Calculation (DL) Name
Value TX i ic
TX i ic
C Traffic – n DL
TX i ic
CNR Traffic
TX i ic
Mi
DL
With MIMO: CNR Traffic + G Div – DL + G Div TX i ic
TX i ic
C Pilot – n DL
TX i ic
CNR Pilot
TX i ic
Mi
With MIMO: CNR Pilot + G Div – DL +
DL G Div
10.2.11 Traffic and Pilot C/(I+N) Calculation (DL) Name
Value TXj jc IDL -----------------C Traffic – 10 Log 10 10 All TX j jc TX i ic
TX i ic
CINR Traffic
TX i ic
Unit TX i ic n DL + I Inter – Tech + -------------------10 DL 10 Mi
+ NR Inter – Tech DL dB
Description
Traffic C/(I+N) for a cell
DL
With MIMO: CINR Traffic + G Div – DL + G Div TX jc
TX i ic
TX i ic
CINR Pilot
C Pilot
I j DL -----------------10 10 – 10 Log All TXj jc
TX ic i
TX ic
i n DL --------------------- Inter – Tech Inter – Tech 10 +I + NR +10 DL DL dB M
i
Pilot C/(I+N) for a cell
DL
With MIMO: CINR Pilot + G Div – DL + G Div TX jc
TX i ic
I + N DL
682
TX ic
i I j n DL DL ------------------ --------------------- 10 10 + I Inter – Tech + 10 10 + NR Inter – Tech 10 Log DL DL All TXj jc
dBm
Traffic Total Noise (I+N) for a cell
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10.2.12 Traffic Signal Level Calculation (UL) Name
Value M
M
i C UL
Unit
Description
dBm
Received uplink signal level
dBm
Uplink EIRP of a user equipment
Unit
Description
dBm
Thermal noise for a cell
dBm
Uplink noise for a cell
Unit
Description
dBm
Uplink interference received at a cell
dB
Interference reduction factor due to the co- and adjacent channel overlap
dB
Interference reduction factor due to the interfering mobile’s uplink traffic load
i j 10 Log p Collision – UL
db
Interference reduction factor due to uplink segmentation
SC Com -----------------TX i ic SC
None
Uplink segmentation collision probability
i
EIRP UL – L Path – M Shadowing – Model – L Indoor + G –L
TX i
Mi
Mi
With P
Mi
i
Mi
– L Ant – L Body P
EIRP UL
TX
Mi
+G
Mi
–L
Mi
Mi
= P Max without power control and P
Mi
Mi
= P Eff after
power control
10.2.13 Traffic Noise Calculation (UL) Name
Value Mi
TX i ic
n 0 – UL
PZ UL TXi ic N SCa – Used n 0 + 10 Log F Sampling ------------------------ TX i ic N SCa – Total
TX i ic
TX i ic
n 0 – UL + nf
n UL
TX i ic
10.2.14 Traffic Interference Calculation (UL) Name M
j
I UL
Value M
TX ic – TX jc i j
j
C UL + f O
M
TX ic – TX jc i j
j
+ f TL – UL + f Seg – UL TX i ic – TX j jc
TX i ic – TX j jc
10 Log r O
fO
M
Mj
j 10 Log TL UL
f TL – UL
TX ic – TX jc
TX ic – TX jc i j
f Seg – UL
TX i ic – TX j jc
p Collision – UL
TX i ic
NR UL
TX i ic
NRUL – Seg
TX i ic
I + N UL
TX i ic IMj n UL UL non-seg M --------------------- TX i ic --------------------------------------------i Inter – Tech 10 10 10 Log + NR UL – n UL dB 10 + 10 All M j All TX j jc
TX i ic IMj n UL UL seg M --------------------- TX i ic i Inter – Tech 10 --------------------------------10 Log + NR UL – n UL 10 10 + 10 All M j All TX jc j
TX i ic
NR UL
TX i ic
+ n UL
TX i ic
TX i ic
or NR UL – Seg + n UL
dB
Segmented zone uplink noise at a cell without smart antennas
dBm
Total Noise (I+N) for a cell
dB
Uplink noise at a cell with smart antenna
2
NR UL
I UL + n I --------------------------------2 n I
Non-segmented zone uplink noise at a cell without smart antennas
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Name TX ic i
I + N UL
Value
Unit
Description
dBm
Total Noise (I+N) for a cell in case of smart antennas
Unit
Description
dB
Uplink C/N at a cell
Unit
Description
dB
Uplink C/(I+N) at a cell
Unit
Description
Hz
Sampling frequency
F Sampling 10 -------------------------------------TX i ic N SCa – Total
kHz
Inter-subcarrier distance
1 ------------------TX i ic F
ms
Useful symbol duration
ms
Cyclic prefix duration
ms
Symbol duration
D Frame – D TTG – D RTG
ms
Used frame duration
D Used Frame Floor ---------------- TXi ic D Symbol
SD
Frame duration in terms of symbol durations
SD
Downlink subframe duration in terms of symbol durations
2
I UL + n I
10.2.15 Traffic C/N Calculation (UL) Name
Value TX i ic
Mi
C UL – n UL
Mi
CNR UL
Mi
TX i ic
With MIMO: CNR UL + G Div – UL +
UL G Div
10.2.16 Traffic C/(I+N) Calculation (UL) Name
Value TX i ic
Mi
Without smart antennas: CNR UL – NR UL Mi
CINR UL
Mi
TX i ic
Mi
With smart antennas: CNR UL – NR UL Mi
TX i ic
or CNR UL – NR UL – Seg
TX i ic
UL
With MIMO: CINR UL + G Div – UL + G Div
10.2.17 Calculation of Total Cell Resources Name
Value
TX ic i F Sampling
W Channel 10 - 8000 Floor f Sampling ----------------------------------8000
F
TX i ic
TX ic i
TX i ic
TX i ic
D Sym – Useful
TX i ic
Used
D Frame TX i ic
N SD – Used Frame
–3
TX i ic
TX i ic
r CP -------------F
D CP
D Symbol
6
TX i ic
TX i ic
D Sym – Useful + D CP TDD
TDD
If DL:UL ratio is defined in percentage: TX ic
TX ic i
N SD – DL Subframe
i TDD DL RoundUp N SD – Used Frame r DL – Frame – O Fixed
If DL:UL ratio is defined in fraction: TDD
TXi ic N SD – DL DL RoundUp N SD – Used Frame ----------------------------------------- – O Fixed TDD TDD N SD – DL + N SD – UL
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Name TX ic i
R DL
=
TX ic i
N Sym – DL Subframe
Value
Unit
Description
M i DL PZ O Variable TXi ic DL - Floor N SD – DL Subframe N SCa – Data 1 – -------------------100
Symbols
Total downlink cell resources, i.e., the number of symbols in the downlink subframe
SD
Uplink subframe duration in terms of symbol durations
Symbols
Total uplink cell resources, i.e., the number of symbols in the uplink subframe
If DL:UL ratio is defined in percentage: TX ic
i TDD UL RoundDown N SD – Used Frame 1 – r DL – Frame – O Fixed
TX ic i
If DL:UL ratio is defined in fraction:
N SD – UL Subframe
TDD
TX i ic N SD – UL UL RoundDown N SD – Used Frame ----------------------------------------- – O Fixed TDD TDD N SD – DL + N SD – UL TX i ic
R UL
=
TX i ic
N Sym – UL Subframe
M i UL PZ UL O Variable TXi ic Floor N SD – UL Subframe N SCa – Data 1 – --------------------- 100
10.2.18 Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-user Throughput Calculation Name
Value TX i ic
R DL
M B
Unit
Description
kbps
Downlink peak MAC channel throughput
kbps
Downlink effective MAC channel throughput
kbps
Downlink application channel throughput
kbps
Downlink peak MAC cell capacity
kbps
Downlink effective MAC cell capacity
kbps
Downlink application cell capacity
kbps
Downlink peak MAC throughput per user
i
DL --------------------------------D Frame TX ic i
R DL
M i B DL
TX ic
i For proportional fair schedulers: --------------------------------- G MUG – DL D Frame Mi
CTP P – DL
M
i
With downlink segmentation: CTP P – DL f Segment – DL With MIMO (SU-MIMO):
Mi
B DL
Max
=
Mi
1 + f SU – MIMO G SU – MIMO – 1
B DL
With MIMO (AMS):
Mi B DL
TX i ic
=
Max
Mi B DL
TX i ic
if CNR Preamble T AMS M
i
CTP E – DL Mi
CTP A – DL Mi
Cap P – DL M
i
Cap E – DL Mi
Cap A – DL
M
i PUTP P – DL
1 + f SU – MIMO G SU – MIMO – 1 TX i ic
M
M
i i CTP P – DL 1 – BLER B DL Mi
Mi Mi f TP – Scaling - – TP Offset CTP E – DL -----------------------100 TX i ic
Mi
CTP P – DL TL DL – Max M
M
i i Cap P – DL 1 – BLER BDL Mi
Mi f TP – Scaling - – TP Offset Cap E – DL -----------------------100 Mi
TX i ic
or CINR Preamble T AMS
Mi
Cap P – DL ----------------------TX i ic N Users – DL
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Name
Value
Unit
Description
kbps
Downlink effective MAC throughput per user
kbps
Downlink application throughput per user
kbps
Uplink peak MAC channel throughput
kbps
Uplink effective MAC channel throughput
kbps
Uplink application channel throughput
kbps
Uplink peak MAC cell capacity
kbps
Uplink effective MAC cell capacity
kbps
Uplink application cell capacity
kbps
Uplink peak MAC allocated bandwidth throughput
kbps
Uplink effective MAC allocated bandwidth throughput
kbps
Uplink application allocated bandwidth throughput
Cap Mi M P – UL - ABTP P –i UL Min ---------------------- TXi ic N Users – UL
kbps
Uplink peak MAC throughput per user
Cap Mi M E – UL - ABTP E –i UL Min ----------------------TX i ic N Users – UL
kbps
Uplink effective MAC throughput per user
M
i
Cap E – DL ----------------------TX ic i N Users – DL
M
i PUTP E – DL
M
Mi
i
Mi f TP – Scaling - – TPOffset PUTP E – DL -----------------------100 Mi
PUTP A – DL
TX ic i
R UL
Mi B UL
--------------------------------D Frame TX i ic
R UL
B
Mi
TX ic
i UL For proportional fair schedulers: --------------------------------- G MUG – UL D Frame
With MIMO (SU-MIMO): Mi
CTP P – UL
M
i B UL
=
Max
1 + f SU – MIMO G SU – MIMO – 1
M
i B UL
With MIMO (AMS): B
Max
=
Mi
B
UL
TX i ic
Mi
1 + f SU – MIMO G SU – MIMO – 1
UL
TX i ic
if CNR Preamble T AMS
TX i ic
TX i ic
or CINR Preamble T AMS
With MIMO (MU-MIMO) in uplink throughput coverage predictions: TX i ic
R UL
Mi B UL
TX ic
--------------------------------- G MUi – MIMO D Frame M
M
Mi
i i CTP P – UL 1 – BLER B UL
M
Mi f TP – Scaling CTP E – UL ------------------------- – TP Offset 100
CTP E – UL
M
i
CTP A – UL M
i
Cap P – UL
Mi
M
i
TX ic i
i
CTP P – UL TL UL – Max M
M
Mi
i i Cap P – UL 1 – BLER B UL
M
Mi f TP – Scaling Cap E – UL ------------------------- – TP Offset 100
Cap E – UL
M
i
Cap A – UL
Mi
i
M
M
ABTP P – UL
Mi
ABTPE – UL Mi
ABTP A – UL
M
i PUTP P – UL
M
i PUTP E – UL
686
i
N SC – UL CTP P – UL ----------------Mi
Mi
i PZ UL N SC
M
M
i i ABTP P – UL 1 – BLER B UL
M
i ABTP E – UL
Mi
M f TP – Scaling i - – TP Offset -----------------------100
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Name M
Value M
i
PUTP A – UL
M
i PUTP E – UL
i
M f TP – Scaling i ------------------------- – TP Offset 100
Unit
Description
kbps
Uplink application throughput per user
10.2.19 Scheduling and Radio Resource Management Name
Value
Unit
Description
Sel Mi R Min – DL
TPD Min – DL ---------------------------
None
Resources allocated to a mobile to satisfy its minimum throughput demand in downlink
None
Resources allocated to a mobile to satisfy its minimum throughput demand in uplink
None
Remaining downlink cell resources after allocation for minimum throughput demands
R Min – UL
None
Remaining uplink cell resources after allocation for minimum throughput demands
Sel Mi
Sel Mi
kbps
Remaining throughput demand for a mobile in downlink
Sel Mi
Sel Mi
kbps
Remaining throughput demand for a mobile in uplink
TX i ic
kbps
Downlink peak channel throughput with multi-user diversity gain (Proportional Fair)
TX ic i
kbps
Uplink peak channel throughput with multi-user diversity gain (Proportional Fair)
None
Remaining resource demand for a mobile in downlink
None
Remaining resource demand for a mobile in uplink
Sel Mi
Sel Mi
CTP P – DL M
Sel i
TPD Min – UL ---------------------------
Sel M i R Min – UL
M
Sel i
CTP P – UL TX i ic
R Rem – DL
TX i ic
R Rem – UL
TX i ic
TL DL – Max –
Sel Mi TX i ic
TL DL – Max –
M Sel Mi
TPD Rem – DL Sel Mi
TPD Rem – UL Sel Mi
CTP P – DL Sel Mi
CTP P – UL
Sel Mi RD Rem – DL
Sel Mi
R Min – DL
Sel Mi
Sel i
TPD Max – DL – TPD Min – DL TPD Max – UL – TPD Min – UL Sel Mi
CTP P – DL M
Without MUG
G MUG – DL
Without MUG
G MUG – UL
Sel i
CTP P – UL
Sel Mi
TPD Rem – DL ---------------------------Sel Mi
CTP P – DL M
Sel M i RD Rem – UL
Sel i
TPD Rem – UL ---------------------------Sel M i CTP P – UL
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Name
Value
Unit
Description
None
Resources allocated to a mobile to satisfy its maximum throughput demand in downlink
None
Resources allocated to a mobile to satisfy its maximum throughput demand in uplink
Sel Mi TXi ic Min R Rem – DL RD Rem – DL Sel M i
None
Effective remaining downlink resources in a cell (Proportional Demand)
Sel Mi TX i ic Min R Rem – UL RD Rem – UL Sel Mi
None
Effective remaining uplink resources in a cell (Proportional Demand)
None
QoS class bias (Biased (QoS Class))
None
Remaining downlink cell resources after allocation for minimum throughput demands for a QoS class (Biased (QoS Class))
TX ic i
Sel
R Rem – DL Mi - Proportional Fair: Min RD Rem – DL -------------------N Sel Mi
TX i ic
RD Rem – DL Proportional Demand: R Eff – Rem – DL ---------------------------------Sel Mi
RDRem – DL
M Sel i R Max – DL M
Biased (QoS Class):
Sel i TX i ic
Sel Mi Min RD Rem – DL
R QoS – DL -------------------- N QoS
Sel Mi
TPD Rem – DL Max Aggregate Throughput: --------------------------Sel Mi
CTP P – DL TX i ic
Sel
Mi R Rem – DL - Round Robin: Min RD Rem – DL -------------------N TX i ic
Sel
R Rem – UL Mi - Proportional Fair: Min RD Rem – UL -------------------N Sel Mi
TX i ic
RD Rem – UL Proportional Demand: R Eff – Rem – UL ---------------------------------Sel Mi
RDRem – UL
M Sel i R Max – UL M
Sel i TX i ic
Sel Mi
R QoS – UL - Biased (QoS Class): Min RD Rem – UL ------------------N QoS Sel Mi
TPD Rem – UL Max Aggregate Throughput: --------------------------Sel Mi
CTP P – UL TX i ic
Sel
Mi R Rem – UL - Round Robin: Min RD Rem – UL -------------------N
TX i ic
R Eff – Rem – DL
TX ic i R Eff – Rem – UL
QoS
Sel Mi
Sel Mi
Sel Mi
R Max – ErtPS f Bias R Max – rtPS R Max – nrtPS - = -------------------------1 + --------= -------------------------= -------------------------Sel Sel Sel 100 Mi Mi Mi R Max – rtPS R Max – nrtPS R Max – BE r
TX i ic
R QoS – DL
1 QoS N QoS --- TX i ic R Rem – DL ------------------------------------------------------r 1 QoS N QoS ---
All QoS
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Name
Value
Unit
Description
TX ic i R QoS – UL
1 QoS N QoS --- TX ic i R Rem – UL ------------------------------------------------------r 1 QoS N QoS ---
None
Remaining downlink cell resources after allocation for minimum throughput demands for a QoS class (Biased (QoS Class))
Sel Sel Mi Mi R Max – DL CTP E – DL Sel M i Site Max 1 ------------------------------------------------------------------------------------------------------- Sel Sel Mi Mi Site R Min – DL CTP E – DL TP BH – DL – Sel M i Site
None
Site backhaul overflow ratio in downlink
Sel Sel Mi Mi R CTP Max – UL E – UL Sel M Site i Max 1 ------------------------------------------------------------------------------------------------------Sel Sel M M Site i i R Min – UL CTP E – UL TP BH – UL – Sel M Site i
None
Site backhaul overflow ratio in uplink
None
Total resources assigned to a mobile in downlink (Downlink traffic load of the mobile)
None
Total resources assigned to a mobile in uplink (Uplink traffic load of the mobile)
Unit
Description
kbps
Downlink peak MAC user throughput
kbps
Downlink effective MAC user throughput
kbps
Downlink application user throughput
kbps
Uplink peak MAC user throughput
kbps
Uplink effective MAC user throughput
kbps
Uplink application user throughput
r
All QoS
Site
BHOF DL
Site
BHOF DL
Sel
Sel Mi
TL DL
Sel Mi
= R DL
Sel Mi
Sel Mi
R Mi Mi Max – DL CTP P – DL R Min – DL CTP P – DL + -----------------------------------------------Site BHOF DL -----------------------------------------------------------------------------------------------------------------Sel
Sel Mi
CTP P – DL Sel
Sel Mi
TL UL
Sel Mi
= R UL
Sel Mi
Sel Mi
R Mi Mi Max – UL CTP P – UL R Min – UL CTP P – UL + -----------------------------------------------Site BHOF UL -----------------------------------------------------------------------------------------------------------------Sel
Sel Mi
CTP P – UL
10.2.20 User Throughput Calculation Name Sel Mi
UTP P – DL Sel Mi
UTP E – DL Sel i UTP A – DL M
Sel Mi
UTP P – UL Sel Mi
UTP E – UL Sel Mi
UTP A – UL
Value Sel Mi
R DL
Sel Mi
CTP P – DL
Sel
Sel
M Mi i UTP P – DL 1 – BLER B DL Sel Mi
Sel Mi
Sel
Mi f TP – Scaling UTP E – DL ------------------------- – TP Offset 100 Sel Mi
R UL
Sel Mi
CTP P – UL
Sel
Sel
Mi Mi UTP P – UL 1 – BLER B UL
Sel Mi
Sel Mi
Sel
Mi f TP – Scaling - – TP Offset UTP E – UL -----------------------100
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10.3 Available Calculations 10.3.1 Point Analysis 10.3.1.1 Profile View The point analysis profile view displays the following calculation results for the selected transmitter based on the calculation algorithm described in "Preamble Signal Level Calculation" on page 707.
L
M
i
TX ic i
•
Preamble signal level C Preamble
•
Path loss L Path
•
Total losses L Total
,G
M
i
M
i
M
i
, L Ant , and L Body are not used in the calculations performed for the profile view.
10.3.1.2 Reception View Analysis provided in the reception view is based on path loss matrices. So, you can display received signal levels from the cells for which calculated path loss matrices are available. For each cell, Atoll displays the received preamble, pilot, or traffic signal level or C/N. Reception level bar graphs show the signal levels or C/N in decreasing order. The maximum number of bars in the graph depends on the preamble signal level of the best server. The bar graph displays cells whose received preamble signal levels are higher than their preamble C/N thresholds and are within a 30 dB margin from the highest preamble signal level. You can use a value other than 30 dB for the margin from the highest preamble signal level, for example a smaller value for improving the calculation speed. For more information on defining a different value for this margin, see the Administrator Manual.
10.3.1.3 Interference View Analysis provided in the interference view is based on path loss matrices. So, you can display the received signal level from the best server and interfering signal levels from other cells for which calculated path loss matrices are available. For each cell, Atoll displays the best server preamble, pilot, or traffic signal level, and interference from other cells. Interference level bar graphs show the interference levels on different channels in decreasing order. The maximum number of bars in the graph depends on the highest interference level on the studied channel. The bar graph displays cells whose C/ N are higher than the minimum interferer C/N threshold and whose interference levels are within a 30 dB margin from the highest interference level on the studied channel. You can use a value other than 30 dB for the margin from the highest interference level in the studied channel, for example a smaller value for improving the calculation speed. For more information on defining a different value for this margin, see the Administrator Manual.
10.3.1.4 Details View Analysis provided in the details view is based on path loss matrices. So, you can display the received signal level from the best server and interfering signal levels from other cells for which calculated path loss matrices are available. For each cell, Atoll displays the best server preamble signal level and interference from other cells. The results for the best server (first row) are displayed using bold italic characters. Other cells are listed in the decreasing order of preamble signal level. All the cells from which the received preamble signal level is higher than their preamble C/N thresholds are listed in the table. As well, interference values are listed for all the cells whose C/N are higher than the minimum interferer C/N threshold and whose interference levels are within a 30 dB margin from the highest interference level on the preamble. You can use a value other than 30 dB for the margin from the highest interference level on the preamble, for example a smaller value for improving the calculation speed. For more information on defining a different value for this margin, see the Administrator Manual.
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10.3.2 Coverage Predictions 10.3.2.1 Preamble Signal Level Coverage Predictions The following coverage predictions are based on the received preamble signal levels: • • •
Coverage by Transmitter Coverage by Signal Level Overlapping Zones
For these calculations, Atoll calculates the received preamble signal level. Then, Atoll determines the selected display parameter on each pixel inside the cell’s calculation area. Each pixel within the calculation area of TXi(ic) is considered a noninterfering receiver. For these calculations, the best server calculation is always based on preamble signal level. These coverage predictions do not depend on the traffic input. Therefore, these calculations are of special interest before and during the deployment stage of the network to study the coverage footprint of the system. L
Mi
,G
Mi
Mi
Mi
, L Ant , and L Body are not considered in the calculations performed for the preamble signal level based coverage
predictions. The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). For more information on preamble signal level calculations, see "Preamble Signal Level Calculation" on page 707 For more information on coverage area determination and available display options, see: • •
"Coverage Area Determination" on page 691. "Coverage Display Types" on page 692.
Coverage Area Determination Atoll uses parameters entered in the Condition tab of the coverage prediction properties dialogue to determine coverage areas to display. There are three possibilities. •
All Servers The coverage area of each cell TXi(ic) corresponds to the pixels where. TX ic
TX ic
TX ic
i i i MinimumThreshold C Preamble or L Total or L Path MaximumThreshold
•
Best Signal Level and a Margin The coverage area of each cell TXi(ic) corresponds to the pixels where. TX ic
TX ic
TX ic
i i i MinimumThreshold C Preamble or L Total or L Path MaximumThreshold
AND TX i ic TX j jc C Preamble Best C Preamble – M ji
Where M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels where the received preamble signal level from TXi(ic) is the highest. If M = 2 dB, Atoll considers pixels where the received preamble signal level from TXi(ic) is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels where the received preamble signal level from TXi(ic) is 2 dB higher than the received preamble signal levels from the cells which are 2nd best servers.
•
Second Best Signal Level and a Margin The coverage area of each cell TXi(ic) corresponds to the pixels where. TX ic
TX ic
TX ic
i i i MinimumThreshold C Preamble or L Total or L Path MaximumThreshold
AND
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TX ic
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TX jc
nd i j C Preamble 2 Best C Preamble – M ji
Where M is the specified margin (dB). The 2nd Best function considers the second highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels where the received preamble signal level from TXi(ic) is the second highest. If M = 2 dB, Atoll considers pixels where the received preamble signal level from TXi(ic) is either the second highest or within a 2 dB margin from the second highest. If M = -2 dB, Atoll considers pixels where the received preamble signal level from TXi(ic) is 2 dB higher than the received preamble signal levels from the cells which are 3rd best servers.
Coverage Display Types A pixel of a coverage area is coloured if the calculated value of the selected display parameter is greater than or equal to the defined thresholds values. Coverage consists of several independent layers that can be displayed and hidden on the map. It is possible to display the coverage predictions with colours depending on any transmitter or cell attribute, and other criteria such as: • • • • • • •
Signal Level (dBm, dBµV, dBµV/m) Best Signal Level (dBm, dBµV, dBµV/m): Where cell coverage areas overlap, Atoll keeps the highest value of the signal level. Path Loss (dB) Total Losses (dB) Best Server Path Loss (dB): Where cell coverage areas overlap, Atoll determines the best cell (i.e., the cell with the highest preamble signal level) and evaluates the path loss from this cell. Best Server Total Losses (dB): Where cell coverage areas overlap, Atoll determines the best cell (i.e., the cell with the highest preamble signal level) and evaluates the total losses from this cell. Number of Servers: Atoll evaluates the number of cells that cover a pixel (i.e., the pixel falls within the coverage areas of these cells).
10.3.2.2 Effective Signal Analysis Coverage Predictions The following coverage predictions are based on the received preamble, traffic, or pilot signal levels and noise, and take into account the receiver characteristics ( L • •
Mi
,G
Mi
Mi
Mi
, L Ant , and L Body ) when calculating the required parameter:
Effective Signal Analysis (DL) Effective Signal Analysis (UL)
For these calculations, Atoll calculates the received signal level or C/N level at each pixel for the channel type being studied, i.e., preamble, traffic, or pilot. Each pixel within the calculation area of TXi(ic) is considered a non-interfering receiver. The properties of the non-interfering probe receiver are set by selecting a terminal, a mobility type, and a service. These coverage predictions do not depend on the traffic input. Therefore, these calculations are of special interest before and during the deployment stage of the network to study the coverage footprint of the system. The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). For more information on signal level calculations, see: • • •
"Preamble Signal Level Calculation" on page 707. "Traffic and Pilot Signal Level Calculation (DL)" on page 715. "Traffic Signal Level Calculation (UL)" on page 729
For more information on permutation zone selection, see "Permutation Zone Selection" on page 714. For more information on C/N level calculations, see: • • •
"Preamble C/N Calculation" on page 712. "Traffic and Pilot C/N Calculation (DL)" on page 726 "Traffic C/N Calculation (UL)" on page 734.
For more information on coverage area determination and available display options, see: • •
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Coverage Area Determination These coverage predictions are all best server coverage predictions, i.e., the coverage area of each cell comprises the pixels where the cell is the best server. Best server for each pixel is calculated as explained in "Best Server Determination" on page 713. Coverage Display Types A pixel of a coverage area is coloured if the calculated value of the selected display type parameter is greater than or equal to the defined thresholds values. Coverage consists of several independent layers that can be displayed and hidden on the map. It is possible to display the Effective Signal Analysis (DL) coverage prediction with colours depending on the following display options: • • • • • • • •
Preamble Signal Level (DL) (dBm) Pilot Signal Level (DL) (dBm) Traffic Signal Level (DL) (dBm) Preamble C/N Level (DL) (dB) Pilot C/N Level (DL) (dB) Traffic C/N Level (DL) (dB) Permutation Zone (DL) Segment
It is possible to display the Effective Signal Analysis (UL) coverage prediction with colours depending on the following display options: • • •
Signal Level (UL) (dBm) C/N Level (UL) (dB) Permutation Zone (UL)
10.3.2.3 C/(I+N)-based Coverage Predictions The following coverage predictions are based on the received signal levels, total noise, and interference. • • • • • • • •
Coverage by C/(I+N) Level (DL) Service Area Analysis (DL) Coverage by Throughput (DL) Coverage by Quality Indicator (DL) Coverage by C/(I+N) Level (UL) Service Area Analysis (UL) Coverage by Throughput (UL) Coverage by Quality Indicator (UL)
These coverage predictions take into account the receiver characteristics ( L
Mi
,G
Mi
Mi
Mi
, L Ant , and L Body ) when calculating the
required parameter. For these calculations, Atoll calculates the received signal level, noise, and interference at each pixel. Each pixel within the calculation area of TXi(ic) is considered a non-interfering receiver. The properties of the non-interfering probe receiver are set by selecting a terminal, a mobility type, and a service. The downlink coverage predictions are based on the downlink traffic loads of the cells, and the uplink coverage predictions are based on the uplink noise rise values. These parameters can either be calculated by Atoll during the Monte Carlo simulations, or set manually by the user for all the cells. The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). For more information on C/(I+N), (I+N), and bearer calculations, see: • • • •
"Preamble C/(I+N) Calculation" on page 712. "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 727. "Traffic C/(I+N) and Bearer Calculation (UL)" on page 737. "Noise Rise Calculation (UL)" on page 733
For more information on thoughput calculations, see: •
"Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743.
For more information on coverage area determination and available display options, see: • •
"Coverage Area Determination" on page 694. "Coverage Display Types" on page 694.
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Coverage Area Determination These coverage predictions are all best server coverage predictions, i.e., the coverage area of each cell comprises the pixels where the cell is the best server. Best server for each pixel is calculated as explained in "Best Server Determination" on page 713. Coverage Display Types A pixel of a coverage area is coloured if the calculated value of the selected display type parameter is greater than or equal to the defined thresholds values. Coverage consists of several independent layers that can be displayed and hidden on the map. It is possible to display the Coverage by C/(I+N) Level (DL) coverage prediction with colours depending on the following display options: • • • • •
Preamble C/(I+N) Level (DL) (dB) Preamble Total Noise (I+N) (DL) (dBm) Traffic C/(I+N) Level (DL) (dB) Traffic Total Noise (I+N) (DL) (dBm) Pilot C/(I+N) Level (DL) (dB)
It is possible to display the Service Area Analysis (DL) coverage prediction with colours depending on the following display options: • • •
Bearer (DL) Modulation (DL): Modulation used by the bearer Service
It is possible to display the Coverage by Throughput (DL) coverage prediction with colours depending on the following display options: • • • • • • • • •
Peak MAC Channel Throughput (DL) (kbps) Effective MAC Channel Throughput (DL) (kbps) Application Channel Throughput (DL) (kbps) Peak MAC Cell Capacity (DL) (kbps) Effective MAC Cell Capacity (DL) (kbps) Application Cell Capacity (DL) (kbps) Peak MAC Throughput per User (DL) (kbps) Effective MAC Throughput per User (DL) (kbps) Application Throughput per User (DL) (kbps)
It is possible to display the Coverage by Quality Indicator (DL) coverage prediction with colours depending on the following display options: •
Quality indicators available in the document (Quality Indicators table): Atoll calculates the downlink traffic C/(I+N) levels received from the best serving cells at each pixel of their coverage areas. From the C/(I+N), Atoll determines the best bearer available on each pixel. Then, for the calculated C/(I+N) and bearer, it determines the value of the selected quality indicator from the quality graphs defined in the WiMAX equipment of the selected terminal.
It is possible to display the Coverage by C/(I+N) Level (UL) coverage prediction with colours depending on the following display options: • • • • •
C/(I+N) Level (UL) (dB) Total Noise (I+N) (UL) (dBm) Allocated Bandwidth (UL) (No. of Subchannels) C/(I+N) Level for 1 Subchannel (UL) (dB) Transmission Power (UL) (dBm)
It is possible to display the Service Area Analysis (UL) coverage prediction with colours depending on the following display options: • • •
Bearer (UL) Modulation (UL): Modulation used by the bearer Service
It is possible to display the Coverage by Throughput (UL) coverage prediction with colours depending on the following display options: • • • • • • • •
694
Peak MAC Channel Throughput (UL) (kbps) Effective MAC Channel Throughput (UL) (kbps) Application Channel Throughput (UL) (kbps) Peak MAC Cell Capacity (UL) (kbps) Effective MAC Cell Capacity (UL) (kbps) Application Cell Capacity (UL) (kbps) Peak MAC Allocated Bandwidth Throughput (UL) (kbps) Effective MAC Allocated Bandwidth Throughput (UL) (kbps)
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• • • •
Application Allocated Bandwidth Throughput (UL) (kbps) Peak MAC Throughput per User (UL) (kbps) Effective MAC Throughput per User (UL) (kbps) Application Throughput per User (UL) (kbps)
It is possible to display the Coverage by Quality Indicator (UL) coverage prediction with colours depending on the following display options: •
Quality indicators available in the document (Quality Indicators table): Atoll calculates the uplink traffic C/(I+N) levels received at the best serving cells from each pixel of their coverage areas. From the C/(I+N), Atoll determines the best bearer available on each pixel. Then, for the calculated C/(I+N) and bearer, it determines the value of the selected quality indicator from the quality graphs defined in the WiMAX equipment of the best serving cell.
10.3.2.4 Cell Identifier Collision Zones Coverage Prediction The Cell Identifier Collision Zones coverage prediction is based on the received preamble signal levels. Atoll calculates the received preamble signal level then Atoll determines the selected display parameter on each pixel inside the cell’s calculation area. Each pixel within the calculation area of TXi(ic) is considered a non-interfering receiver. L
M
i
,G
M
i
M
i
M
i
, L Ant , and L Body are
not considered in the calculations. The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). For more information on preamble signal level calculations, see "Preamble Signal Level Calculation" on page 707 For more information on coverage area determination and available display options, see: • •
"Coverage Area Determination" on page 695. "Coverage Display Types" on page 695.
Coverage Area Determination Atoll uses parameters entered in the Condition tab of the coverage prediction properties dialogue to determine coverage areas to display. It is possible to determine the coverage area based on the best signal level. The coverage area of each cell TXi(ic) corresponds to the pixels where: TX i ic TX i ic TX i ic TX i ic TX j jc MinimumThreshold C Preamble or L Total or L Path MaximumThreshold AND C Preamble Best C Preamble – M ji
Where M is the specified margin (dB). The Best function considers the highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels where the received preamble signal level from TXi(ic) is the highest. If M = 2 dB, Atoll considers pixels where the received preamble signal level from TXi(ic) is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels where the received preamble signal level from TXi(ic) is 2 dB higher than the received preamble signal levels from the cells which are 2nd best servers.
Coverage Display Types A pixel of a coverage area is coloured if the calculated value of the selected display parameter is greater than or equal to the defined thresholds values. Coverage consists of several independent layers that can be displayed and hidden on the map. It is possible to display the coverage predictions with colours per cell or: • •
Number of interferers Number of interferers per cell
10.3.3 Calculations on Subscriber Lists When calculations are performed on a list of subscribers by running the Automatic Server Allocation, Atoll calculates the path loss again for the subscriber locations and heights because the subscriber heights can be different from the default receiver height used for calculating the path loss matrices. Atoll calculates the following parameters for each subscriber in the list whose Lock Status is set to None. •
Serving Base Station and Reference Cell as described in "Best Server Determination" on page 713.
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Atoll calculates the following parameters for each subscriber in the list that has a serving base station assigned and whose Lock Status is set to None or Server. • •
Azimuth ( ): Angle with respect to the north for pointing the subscriber terminal antenna towards its serving base station. Mechanical Downtilt ( ): Angle with respect to the horizontal for pointing the subscriber terminal antenna towards its serving base station.
Atoll calculates the remaining parameters for each subscriber in the list that has a serving base station assigned, using the properties of the default terminal and service. For more information, see: • • • • • • • • •
"Preamble Signal Level Calculation" on page 707. "Preamble C/(I+N) Calculation" on page 712. "Permutation Zone Selection" on page 714. "Traffic and Pilot Signal Level Calculation (DL)" on page 715. "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 727. "Traffic Signal Level Calculation (UL)" on page 729. "Noise Rise Calculation (UL)" on page 733. "Traffic C/(I+N) and Bearer Calculation (UL)" on page 737. "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743.
10.3.4 Monte Carlo Simulations The simulation process is divided into two steps. •
Generating a realistic user distribution as explained in "User Distribution" on page 696. Atoll generates user distributions as part of the Monte Carlo algorithm based on traffic data. The resulting user distribution complies with the traffic database and maps selected when creating simulations.
•
Scheduling and Radio Resource Management as explained under "Simulation Process" on page 699.
10.3.4.1 User Distribution During each simulation, Atoll performs two random trials. The first random trial generates the number of users and their activity status as explained in the following sections depending on the type of traffic input. • •
"Simulations Based on User Profile Traffic Maps and Subscriber Lists" on page 696. "Simulations Based on Sector Traffic Maps" on page 698.
Once all the user characteristics have been determined, a second random trial is performed to obtain their geographical locations weighted according to the clutter classes, and whether they are indoor or outdoor according to the percentage of indoor users per clutter class. Atoll determines the total number of users attempting connection in each simulation based on the Poisson distribution. This may lead to slight variations in the total numbers of users in different simulations. To have the same total number of users in each simulation of a group, add the following lines in the Atoll.ini file: [Simulation] RandomTotalUsers=0
10.3.4.1.1
Simulations Based on User Profile Traffic Maps and Subscriber Lists User profile environment based traffic maps: Each pixel of the map is assigned an environment class which contains a list of user profiles with an associated mobility type and a given density, i.e., number of users of a user profile per km². User profile traffic maps: Each polygon or line of the map is assigned a density of users with a given user profile and mobility type. If the map is composed of points, each point is assigned a number of users with given user profile and mobility type. Fixed subscribers listed in subscriber lists have a user profile assigned to each of them. User profiles model the behaviour of the different user categories. Each user profile contains a list of services and parameters describing how these services are accessed by the user. The number of users of each user profile is calculated from the surface area (SEnv) of each environment class map (or each polygon) and the user profile density (DUP). N Users = S Env D UP
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•
In case of user profile traffic maps composed of lines, the number of users of each user profile is calculated from the line length (L) and the user profile density (DUP) (users per km): N Users = L D UP
•
The number of users is a direct input when a user profile traffic map is composed of points.
Atoll calculates the probability for a user being active at a given instant in the uplink and in the downlink according to the service usage characteristics described in the user profiles, i.e., the number of voice calls or data sessions, the average duration of each voice call, or the volume of the data transfer in the uplink and the downlink in each data session. Voice Service (v) User profile parameters for voice type services are: • •
The user terminal equipment used for the service (from the Terminals table). The average number of calls per hour N Call .
•
The average duration of a call (seconds) D Call .
N Call D Call Calculation of the service usage duration per hour ( p 0 : probability of an active call): p 0 = ---------------------------3600 Calculation of the number of users trying to access the service v ( n v ): n v = N Users p 0 The activity status of each user depends on the activity periods during the call, i.e., the uplink and downlink activity UL
DL
factors defined for the voice type service v, f Act and f Act . Calculation of activity probabilities: UL
DL
Probability of being inactive: p Inactive = 1 – f Act 1 – f Act UL
UL
DL
Probability of being active in the uplink: p Active = f Act 1 – f Act DL
DL
UL
Probability of being active in the downlink: p Active = f Act 1 – f Act UL + DL
UL
DL
Probability of being active in the uplink and downlink both: p Active = f Act f Act Calculation of number of users per activity status: Number of inactive users: n v – Inactive = n v p Inactive UL
UL
Number of users active in the uplink: n v – Active = n v p Active DL
DL
Number of users active in the downlink: n v – Active = n v p Active UL + DL
UL + DL
Number of users active in the uplink and downlink both: n v – Active = n v p Active
Therefore, a user can be either active on both links, inactive on both links, active on UL only, or active on DL only. Data Service (d) User profile parameters for data type services are: • •
The user terminal equipment used for the service (from the Terminals table). The average number of data sessions per hour N Session .
•
The average data volume (in kBytes) transferred in the downlink V
•
The average throughputs in the downlink
Calculation of activity probabilities: f
UL
DL TP Average
DL
and the uplink UL
and the uplink V
UL TP Average
UL
during a session.
for the service d. DL
N Session V 8 N Session V 8 DL = ------------------------------------------ and f = -----------------------------------------UL DL TP Average 3600 TP Average 3600 UL
DL
Probability of being inactive: p Inactive = 1 – f 1 – f
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Probability of being active in the uplink: p Active = f DL
UL
DL
1 – f
Probability of being active in the downlink: p Active = f
DL
UL
1 – f UL + DL
Probability of being active in the uplink and downlink both: p Active = f
UL
f
DL
Calculation of number of users: Number of inactive users: n d – Inactive = N Users p Inactive UL
UL
Number of users active in the uplink: n d – Active = N Users p Active DL
DL
Number of users active in the downlink: n d – Active = N Users p Active UL + DL
UL + DL
Number of users active in the uplink and downlink both: n d – Active = N Users p Active Calculation of the number of active users trying to access the service d (nd): UL
UL + DL
DL
n d = n d – Active + n d – Active + n d – Active The user distribution per service and the activity status distribution between the users are average distributions. The service and the activity status of each user are randomly drawn in each simulation. Therefore, if you calculate several simulations at once, the average number of users per service and average numbers of inactive, active on UL, active on DL and active on UL and DL users, respectively, will correspond to calculated distributions. But if you check each simulation, the user distribution between services as well as the activity status distribution between users can be different in each of them.
10.3.4.1.2
Simulations Based on Sector Traffic Maps Sector traffic maps per sector are also referred to as live traffic maps. Live traffic data from the OMC is spread over the best server coverage areas of the transmitters included in the traffic map. Either throughput demands per service or the number of active users per service are assigned to the coverage areas of each transmitter. For each transmitter TXi and each service s, •
Sector Traffic Maps (Throughputs) Atoll calculates the number of active users of each service s on UL and DL in the coverage area of TXi as follows: N
UL
UL
DL
TP Cell TP Cell DL = ---------------------- and N = ---------------------UL DL TP Average TP Average UL
Where TP Cell is the total uplink throughput demand defined in the map for any service s for the coverage area of the DL
transmitter, TP Cell is the total downlink throughput demand defined in the map for any service s for the coverage UL
DL
area of the transmitter, TP Average is the average uplink requested throughput of the service s, and TP Average is the average downlink requested throughput of the service s. •
Sector Traffic Maps (# Active Users) UL
Atoll directly uses the defined N and N coverage area using the service s.
DL
values, i.e., the number of active users on UL and DL in the transmitter
At any given instant, Atoll calculates the probability for a user being active in the uplink and in the downlink as follows: Users active in the uplink and downlink both are included in the N
UL
UL accurately determine the number of active users in the uplink ( n Active
and N
DL
values. Therefore, it is necessary to DL
UL + DL
), in the downlink ( n Active ), and both ( n Active ).
As for the other types of traffic maps, Atoll considers both active and inactive users. The activity status of each user depends on the activity periods during the call, i.e., the uplink and downlink activity UL
DL
factors defined for the service, f Act and f Act . Calculation of activity probabilities:
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DL
Probability of being inactive: p Inactive = 1 – f Act 1 – f Act UL
UL
DL
Probability of being active in the uplink: p Active = f Act 1 – f Act DL
DL
UL
Probability of being active in the downlink: p Active = f Act 1 – f Act UL + DL
UL
DL
Probability of being active in the uplink and downlink both: p Active = f Act f Act Calculation of the number of active users trying to access the service: We have: N
UL
UL + DL
UL
= p Active + p Active n and N
DL
UL + DL
DL
= p Active + p Active n
Where, n is the total number of active users in the transmitter coverage area using the service. Calculation of number of users per activity status: UL
UL + DL
DL
UL + DL
N p Active N p Active UL + DL Number of users active in the uplink and downlink both: n Active = Min -------------------------------------- -------------------------------------- or UL UL + DL DL + DL p Active + p Active p Active + p UL Active UL + DL
simply, n Active = Min N
UL
DL
f Act N
DL
UL
f Act UL
Number of users active in the uplink: n Active = N
UL
DL
Number of users active in the downlink: n Active = N UL
UL + DL
– n Active DL
UL + DL
– n Active
UL + DL
DL
And, n = n Active + n Active + n Active
Calculation of the number of inactive users attempting to access the service: nv - p Inactive Number of inactive users: n Inactive = --------------------------1 – p Inactive The activity status distribution between users is an average distribution. In fact, in each simulation, the activity status of each user is randomly drawn. Therefore, if you calculate several simulations at once, average numbers of inactive, active on UL, active on DL and active on UL and DL users correspond to the calculated distribution. But if you check each simulation, the activity status distribution between users can be different in each of them.
10.3.4.2 Simulation Process WiMAX cells include intelligent schedulers and radio resource management features for regulating network traffic loads, optimising spectral efficiency, and satisfying the QoS demands of the users. Each Monte Carlo simulation in the Atoll WiMAX BWA module is a snap-shot of the network with resource allocation carried out over a duration of 1 second. The number of WiMAX frames in 1 second depends on the selected frame duration, D Frame . The steps of this algorithm are listed below. The simulation process can be summed up into the following iterative steps. For each simulation, the simulation process, 1. Generates mobiles according to the input traffic data as explained in "User Distribution" on page 696. 2. Sets initial values for the following parameters: •
TX i ic
TX i ic
TX i ic
TX i ic
Cell transmission powers and reductions ( P Preamble , P Traffic , P Pilot , and P Idle – Pilot ) are set to the values defined by the user. Mi
•
Mobile transmission power is set to the maximum mobile power ( P Max ).
•
Cell loads ( TL DL
TX i ic
TX i ic
, TL UL
TX i ic
, NRUL
TX i ic
TX i ic
, NR UL – Seg , SU DL
TX i ic
, and AU DL
) are set to their current values in the
Cells table. 3. Determines the best servers for all the mobiles generated for the simulation as explained in "Best Server Determination" on page 713.
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Figure 10.1: WiMAX Simulation Algorithm For each iteration k, the simulation process, 4. Determines the mobiles which are within the service areas of their best serving cells as explained in "Service Area Calculation" on page 714. 5. Determines the permutation zone assigned to each mobile as explained in "Permutation Zone Selection" on page 714. 6. Determines the downlink and uplink traffic C/(I+N) and bearers for each of these mobiles as explained in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 727 and "Traffic C/(I+N) and Bearer Calculation (UL)" on page 737 respectively. 7. Determines the channel throughputs at the mobile as explained in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743. 8. Performs radio resource management and scheduling to determine the amount of resources to allocate to each mobile according to the QoS and throughput demands of each mobile using the selected scheduler as explained in "Scheduling and Radio Resource Allocation" on page 748. 9. Calculates the user throughputs after allocating resources to each mobile as explained in "User Throughput Calculation" on page 757. 10. Updates the traffic loads, and noise rise values of all the cells according to the resources in use and the total resources as follows: Calculation of Traffic Loads: Atoll calculates the traffic loads for all the cells TXi(ic). TX i ic
TL DL
=
Mi
Mi
700
TX i ic
RDL and TLUL
=
Mi
RUL Mi
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TX ic i
For uplink MU-MIMO, TL UL
M
=
MU – MIMO i
RC UL
MU – MIMO M i
Calculation of Uplink Noise Rise: For each victim cell TXi(ic), the uplink noise rise is calculated and updated by considering each interfering mobile Mj as explained in "Noise Rise Calculation (UL)" on page 733. Calculation of Downlink Segmentation Usage: Atoll calculates the segmentation usages for all the cells as follows: Mi
M TX i ic
i PZ
Mi
R DL
Mi PZ DL = Seg
= Seg
DL = -----------------------------------------------------------TX i ic TL DL
SU DL
M
Where Mi
i
R DL
Mi PZ DL = Seg
is the sum of the percentages of the downlink cell resources allocated to mobiles
M i PZ DL = Seg
served by the downlink segmented permutation zone. Calculation of Downlink AAS Usage: Atoll calculates the downlink AAS usages for all the cells as follows:
AAS
Mi
TX i ic
AAS = ------------------------------TX i ic TL DL
AU DL
Where
Mi
R DL
Mi
M
i
R DL
AAS
is the sum of the percentages of the downlink cell resources allocated to mobiles served by the
AAS
smart antennas. Calculation of Uplink MU-MIMO Gain: Atoll calculates the uplink MU-MIMO gain for all the cells as follows: MU – MIMO Mi
TX i ic
G MU – MIMO =
R UL
MU – MIMO Mi ------------------------------------------------------------MU – MIMO Mi RC UL
M
MU – MIMO i MU – MIMO Mi
Where
R UL
is the sum of the percentages of the uplink cell resources allocated to MU-MIMO
MU – MIMO Mi
mobiles and
MU – MIMO Mi
RC UL
is the sum of the real resource consumption of MU-MIMO mobiles.
MU – MIMO Mi
11. Performs the convergence test to see whether the differences between the current and the new loads are within the convergence thresholds. The convergence criteria are evaluated at the end of each iteration k, and can be written as follows: TX i ic
TL DL
k
=
TX ic
i Max TL DL All TX ic i
TX i ic
k
– TL DL
k – 1
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TL UL
=
k
k
=
TX i ic
Req
TX ic i
k
– TL UL
TX ic
i Max NR UL All TX ic i
TX i ic
If TL DL
TX ic
i Max TL UL All TX ic i
TX ic i
NR UL
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, TL UL
k – 1
TX ic i
k
– NR UL
k – 1
TX i ic
Req
, and NR UL
Req
are the simulation convergence thresholds defined when creating
the simulation, Atoll stops the simulation in the following cases. Convergence: Simulation has converged between iteration k - 1 and k if: TX i ic
TL DL
TX i ic
k
TL DL
TX i ic
Req
AND TL UL
TX i ic
k
TL UL
TX i ic
Req
AND NR UL
TX i ic
k
NR UL
Req
No convergence: Simulation has not converged even after the last iteration, i.e., k = Max Number of Iterations defined when creating the simulation, if: TX ic i
TL DL
TX ic i
k
TL DL
TX ic i
Req
OR TL UL
TX ic i
k
TL UL
TX ic i
Req
OR NR UL
TX ic i
k
NR UL
Req
12. Repeats the above steps (from step 3.) for the iteration k+1 using the new calculated loads as the current loads. Simulation Results At the end of the simulation process, the main results obtained are: • • • • • • • • •
Downlink traffic loads Uplink traffic loads Uplink noise rise received at the main antenna Ssegmented zone uplink noise rise received at the main antenna Angular distributions of downlink traffic power density for cells with smart antennas Angular distributions of uplink noise rise for cells with smart antennas Downlink AAS usage Downlink segmentation usage Uplink MU-MIMO capacity gain
These results can be used as input for C/(I+N)-based coverage predictions. In addition to the above parameters, the simulations also list the connection status of each mobile. Mobiles can be rejected due to: • • • • •
No Coverage: If the mobile does not have any best serving cell (step 3.) or if the mobile is not within the service area of its best server (step 4.). No Service: If the mobile is not able to access a bearer in the direction of its activity (step 6.), i.e., UL, DL, or DL+UL. Scheduler Saturation: If the mobile is not in the list of mobiles selected for scheduling (step 8.) Resource Saturation: If all the cell resources are used up before allocation to the mobile or if, for a user active in uplink, the minimum uplink throughput demand is higher than the uplink allocated bandwidth throughput (step 8.) Backhaul Saturation: If allocating resources to a mobile makes the effective MAC aggregate site throughputs exceed the maximum backhaul throughputs defined for the site. This condition is only verified if the simulation was created with the Backhaul capacity check box selected (step 8.)
Connected mobiles (step 8.) can be: • • •
Connected UL: If a mobile active in UL is allocated resources in UL. Connected DL: If a mobile active in DL is allocated resources in DL. Connected DL+UL: If a mobile active in DL+UL is allocated resources in DL+UL.
10.4 Calculation Details The following sections describe all the calculation algorithms used in point analysis, calculation of coverage predictions, calculations on subscriber lists, and Monte Carlo simulations.
10.4.1 Co- and Adjacent Channel Overlaps Calculation A WiMAX network can consist of cells that use different channel bandwidths. Therefore, the start and end frequencies of all the channels may not exactly coincide. Channel bandwidths of cells can overlap each other with different ratios.
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Figure 10.2: Co-Channel and Adjacent Channel Overlaps The following sections describe how the co- and adjacent channel overlaps are calculated between the channels used by any studied cell TXi(ic) and any other cell TXj(jc) of the network. In terms of interference calculation, the studied cell can be considered a victim of interference received from the other cells that might be interfering the studied cell. TX i ic
If the studied cell is assigned a channel number N Channel , it receives co-channel interference on the channel bandwidth of TX i ic
TX i ic
N Channel , and adjacent channel interference on the adjacent channel bandwidths, i.e., corresponding to N Channel – 1 and TX i ic
N Channel + 1 . In order to calculate the co- and adjacent channel overlaps between two channels, it is necessary to calculate the start and end frequencies of both channels (explained in "Conversion From Channel Numbers to Start and End Frequencies" on page 703). Once the start and end frequencies are known for the studied and other cells, the co- and adjacent overlaps and the total overlap ratio are calculated as respectively explained in: • • •
"Co-Channel Overlap Calculation" on page 704. "Adjacent Channel Overlap Calculation" on page 705. "Total Overlap Ratio Calculation" on page 706.
10.4.1.1 Conversion From Channel Numbers to Start and End Frequencies Input •
TX i ic
TX j jc
F Start – FB and F Start – FB : Start frequency of the frequency band assigned to the cells TXi(ic) and TXj(jc). F Start – FB can be the start frequency of a TDD frequency band ( F Start – FB – TDD ), or the uplink or the downlink start frequency of an FDD frequency band ( F Start – FB – FDD – UL or F Start – FB – FDD – DL ).
• •
First – TX ic i
N Channel TX i ic
First – TX jc j
and N Channel
: First channel numbers the frequency band assigned to the cells TXi(ic) and TXj(jc).
TX j jc
N Channel and N Channel : Channel numbers assigned to cells TXi(ic) and TXj(jc). For FDD networks, Atoll considers that the same channel number is assigned to a cell in the downlink and uplink, i.e., the channel number you assign to a cell is considered for uplink and downlink both. TX i ic
TX j jc
•
W Channel and W Channel : Bandwidths of the channels assigned to cells TXi(ic) and TXj(jc).
•
ICS FB
•
CN FB
TX i ic
TX j jc
and ICS FB
TX i ic
: Inter-channel spacing of the frequency bands assigned to cells TXi(ic) and TXj(jc).
TX j jc
and CN FB
: Channel number step of the frequency bands assigned to cells TXi(ic) and TXj(jc).
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Calculations Channel numbers are converted into start and end frequencies as follows: For cell TXi(ic): TX ic i F Start
TX i ic
F End
=
TX ic i F Start – FB
TX ic
TX i ic
TXi ic – N First – TX i ic Channel Channel N ------------------------------------------------------- TX i ic CN FB
TX ic
i i + W Channel + ICS FB
TX i ic
= F Start + W Channel
For cell TXj(jc): TX j jc
F Start
TX j jc
F End
TX j jc
TX jc
TX j jc
N TXj jc – N First – TX j jc Channel Channel ------------------------------------------------------- TX ic i CN FB
TX jc
j j = F Start – FB + W Channel + ICS FB
TX j jc
= F Start + W Channel
Output TX ic i
TX jc j
•
F Start and F Start : Start frequencies for the cells TXi(ic) and TXj(jc).
•
F End
TX i ic
TX j jc
and F End
: End frequencies for the cells TXi(ic) and TXj(jc).
10.4.1.2 Co-Channel Overlap Calculation Input •
TX i ic
TX j jc
F Start
and F Start : Start frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel
Numbers to Start and End Frequencies" on page 703. •
TX i ic
TX j jc
F End
and F End
: End frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel
Numbers to Start and End Frequencies" on page 703. •
TX ic i
W Channel : Bandwidth of the channel assigned to the studied cell TXi(ic).
Calculations Atoll first verifies that co-channel overlap exists between the cells TXi(ic) and TXj(jc). Co-channel overlap exists if: TX i ic
TX j jc
F Start F End
TX i ic
AND F End
TX j jc
F Start
Otherwise there is no co-channel overlap. Atoll calculates the bandwidth of the co-channel overlap as follows: TX i ic – TX j jc
W CCO
TX jc
TX ic
TX jc
TX ic
j i j i = Min F End F End – Max F Start F Start
The co-channel overlap ratio is given by: TX i ic – TX j jc
r CCO
TX ic – TX jc i j
W CCO = ---------------------------------TX i ic W Channel
Output •
704
TX i ic – TX j jc
r CCO
: Co-channel overlap ratio between the cells TXi(ic) and TXj(jc).
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10.4.1.3 Adjacent Channel Overlap Calculation Input TX ic i
TX jc j
•
F Start
and F Start : Start frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel Numbers to Start and End Frequencies" on page 703.
•
F End
TX i ic
TX j jc
and F End
: End frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel
Numbers to Start and End Frequencies" on page 703. •
TX i ic
W Channel : Bandwidth of the channel assigned to the studied cell TXi(ic).
Calculations Atoll first verifies that adjacent channel overlaps exist between (the lower-frequency and the higher-frequency adjacent channels of) the cells TXi(ic) and TXj(jc). Adjacent channel overlap exists on the lower-frequency adjacent channel if: TX i ic
TX i ic
TX j jc
F Start – W Channel F End
TX i ic
TX j jc
AND F Start F Start
Adjacent channel overlap exists on the higher-frequency adjacent channel if: TX i ic
F End
TX j jc
F End
TX i ic
AND F End
TX i ic
TX j jc
+ W Channel F Start
Otherwise there is no adjacent channel overlap. Atoll determines the adjacent channel overlap ratio as follows: Bandwidth of the lower-frequency adjacent channel overlap: TX i ic – TX j jc
W ACO
L
TX jc
TX ic
TX jc
TX ic
TX ic
j i j i i = Min F End F Start – Max F Start F Start – W Channel
The lower-frequency adjacent channel overlap ratio is given by: TX i ic – TX j jc
W ACO L = ---------------------------------TX i ic W Channel
TX i ic – TX j jc
r ACO
L
Bandwidth of the higher-frequency adjacent channel overlap: TX i ic – TX j jc
W ACO
H
TX j jc
TX i ic
= Min F End F End
TX ic
TX jc
TX ic
i j i + W Channel – Max F Start F End
The higher-frequency adjacent channel overlap ratio is given by: TX i ic – TX j jc
W ACO H = ---------------------------------TX ic i W Channel
TX i ic – TX j jc
r ACO
H
The adjacent channel overlap ratio is given by: TX i ic – TX j jc
r ACO
TX i ic – TX j jc
= r ACO
L
TX i ic – TX j jc
+ r ACO
H
Output •
TX ic – TX jc i j
r ACO
: Adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc).
10.4.1.4 FDD – TDD Overlap Ratio Calculation There are many different interference scenarios possible in a WiMAX network depending on the type of duplexing used by the cells of the network. The most common interference scenarios are FDD-only and TDD-only interferences. However, coexisting FDD and TDD cells may also exist and interfere each other. Atoll models the co-existence of FDD and TDD cells in a network by determining the FDD – TDD overlap ratio as follows:
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Input •
TDD
r DL – Frame : Downlink subframe ratio defined in the global network settings.
Calculations The FDD – TDD overlap ratio is calculated as follows depending on the frequency bands assigned to the cells TXi(ic) and TXj(jc): Frequency Band
TX i ic – TX j jc
Overlap Ratio r FDD – TDD
TXi(ic)
TXj(jc)
TDD
TDD
1
TDD
FDD
1
FDD
TDD
r DL – Frame ----------------------100
FDD
FDD
1
TDD
Output •
TX ic – TX jc i j
r FDD – TDD
: FDD – TDD overlap ratio between the cells TXi(ic) and TXj(jc).
10.4.1.5 Total Overlap Ratio Calculation Input TX i ic – TX j jc
•
r CCO
: Co-channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Co-Channel Overlap Calculation" on page 704.
•
r ACO
TX i ic – TX j jc
: Adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Adjacent Channel
Overlap Calculation" on page 705. •
TX i ic – TX j jc
r FDD – TDD
: FDD – TDD overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "FDD – TDD Overlap Ratio
Calculation" on page 705. TX i ic
•
f ACS – FB : Adjacent channel suppression factor defined for the frequency band of the cell TXi(ic).
•
W Channel and W Channel : Bandwidths of the channels assigned to the cells TXi(ic) and TXj(jc).
TX ic i
TX jc j
Calculations The total overlap ratio is:
TX i ic – TX j jc
rO
=
TX ic
i –f ACS – FB- TX ic – TX jc TX ic – TX jc --------------------------TX ic – TX j jc j i j 10 r i r i + r ACO 10 FDD – TDD CCO
TX i ic
TX j jc
TX i ic
TX j jc
if W Channel W Channel
TX ic
i –f TX i ic ACS – FB TX ic – TX jc TX ic – TX jc ---------------------------- TX ic – TX j jc W i j i j 10 Channel r r i --------------------+ r 10 ACO FDD – TDD TX j jc CCO W Channel
if W Channel W Channel
TX i ic
W Channel The multiplicative factor --------------------is used to normalise the transmission power of the interfering cell TXj(jc). This means that TX j jc W Channel TX j jc
TX j jc
if the interfering cell transmits at X dBm over a bandwidth of W Channel , and it interferes over a bandwidth less than W Channel ,
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TX ic i
W Channel the interference from this cell should not be considered at X dBm but less than that. The factor --------------------converts X dBm over TX jc j W Channel TX jc j
TX jc j
W Channel to Y dBm (which is less than X dBm) over less than W Channel . Output •
TX i ic – TX j jc
rO
: Total co- and adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc).
10.4.2 Preamble Signal Level and Quality Calculations These calculations include the calculation of the received preamble signal level, and the noise and interference on the preamble. The following sections also describe how the received preamble signal level, the noise and interference, C/N, and C/(I+N) ratios are calculated in Atoll: • • • • •
"Preamble Signal Level Calculation" on page 707. "Preamble Noise Calculation" on page 708. "Preamble C/N Calculation" on page 712. "Preamble Interference Calculation" on page 710. "Preamble C/(I+N) Calculation" on page 712.
10.4.2.1 Preamble Signal Level Calculation Input TX i ic
•
P Preamble : Preamble transmission power of the cell TXi(ic).
•
E SA : Number of antenna elements defined for the smart antenna equipment used by the transmitter TXi.
•
G SA
•
Div G SA
•
TX i
Combining
G
TX i
TX
i
: Smart power combining gain offset defined per clutter class.
: Smart antenna diversity gain (for cross-polarised smart antennas) defined per clutter class. : Transmitter antenna gain for the antenna used by the transmitter TXi. i
= L Total – DL ).
L
•
L Model : Loss on the transmitter-receiver path (path loss) calculated using a propagation model.
•
L Ant : Antenna attenuation (from antenna patterns) calculated for the antenna used by the transmitter TXi.
•
M Shadowing – Model : Shadowing margin based on the model standard deviation.
TX
: Total transmitter losses for the transmitter TXi ( L
TX
•
i
In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. •
L Indoor : Indoor losses taken into account when the option "Indoor coverage" is selected.
•
L
Mi Mi
: Receiver terminal losses for the pixel, subscriber, or mobile Mi.
•
G
: Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi.
•
L Ant : Receiver terminal’s antenna attenuation calculated for the pixel, subscriber, or mobile Mi.
Mi
Mi
For calculating the useful signal level from the best serving cell, L Ant is determined in the direction (H,V) = (0,0) from Mi
the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, L Ant is determined in the direction of the interfering cell from the antenna patterns of the antenna used by Mi, while the antenna is pointed towards Mi’s best serving cell. •
Mi
L Body : Body loss defined for the service used by the pixel, subscriber, or mobile Mi.
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M
i
, G
©Forsk 2015
M
i
M
i
M
i
, L Ant , and L Body are not used in the calculations performed for the point
analysis tool’s profile tab and the preamble signal level based coverage predictions. Calculations The received preamble signal level (dBm) from any cell TXi(ic) is calculated for a pixel, subscriber, or mobile Mi as follows: TX i ic
TX i ic
C Preamble = EIRP Preamble – L Path – M Shadowing – Model – L Indoor + G
Mi
–L
Mi
Mi
Mi
– L Ant – L Body
Where EIRP is the effective isotropic radiated power of the cell calculated as follows: TX ic i
TX ic i
•
Without smart antennas: EIRP Preamble = P Preamble + G
•
With smart antennas: EIRP Preamble = P Preamble + G
TX i ic
TX i ic
TX i
TX
i
–L
–L TX i
TX
i TX i
+ 10 Log E SA + G SA
Combining
Div
+ G SA
L Path is the path loss (dB) calculated as follows: TX i
L Path = L Model + L Ant Furthermore, the total losses between the cell and the pixel, subscriber, or mobile Mi can be calculated as follows: L Total = L Path + L
TX
i
+ L Indoor + M Shadowing – Model – G
TX
i
+L
M
i
–G
M
i
M
i
M
i
+ L Ant + L Body
If you wish to exclude the the energy corresponding to the cyclic prefix part of the total symbol duration from the useful signal level, you must add the following lines in the Atoll.ini file: [WiMAX] ExcludeCPFromUsefulPower = 1 TX i ic
When this option is active, the cyclic prefix energy is excluded from C Preamble . In other TX ic
i words, the factor 10 Log 1 – r CP
TX ic
is added to C i Preamble . Independant of the option, interference levels are calculated for the total symbol durations, i.e., the energy of the useful symbol duration and the cyclic prefix energy. Output TX i ic
•
C Preamble : Received preamble signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
L Path : Path loss between the cell TXi(ic) and the pixel, subscriber, or mobile Mi.
•
L Total : Total losses between the cell TXi(ic) and the pixel, subscriber, or mobile Mi.
10.4.2.2 Preamble Noise Calculation For determining the preamble C/N and C/(I+N), Atoll calculates the preamble noise over the bandwidth used by the cell. The used bandwidth depends on the number of subcarriers used by the preamble.The number of subcarriers used by the preamble can be different from the number of subcarriers used by the permutation zones. The preamble noise comprises thermal noise and the noise figure of the equipment. The thermal noise density depends on the temperature, i.e., it remains constant for a given temperature. However, the value of the thermal noise varies with the used bandwidth. Input
708
• •
K: Boltzmann’s constant. T: Temperature in Kelvin.
•
N SCa – Preamble : Number of subcarriers used by the preamble defined for the frame configuration of the cell TXi(ic).
•
N SCa – Total : Total number of subcarriers defined for the frame configuration of the cell TXi(ic).
TX i ic TX i ic
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•
F Sampling : Sampling frequency for the cell TXi(ic) as calculated in "Calculation of Sampling Frequency" on page 740.
•
nf
M
i
: Noise figure of the terminal used for calculations by the pixel, subscriber, or mobile Mi.
Calculations The power spectral density of thermal noise is calculated as follows: n 0 = 10 Log K T 1000 = – 174 dBm/Hz The thermal noise over the preamble for a cell is calculated as: TX i ic
n 0 – Preamble
TX i ic TX ic N SCa – Preamble Preamble i - f Segment = n 0 + 10 Log F Sampling --------------------------------TX i ic N SCa – Total
Effect of Segmentation: The preamble is segmented and one of the three preamble carrier sets is used for transmission. Each preamble carrier set uses 1/3rd of the total number of preamble subcarriers. The power transmitted over the preamble has higher spectral density than the power transmitted over the entire channel bandwidth. This power concentration due to segmentation on the C/N and C/(I+N) results in an increase in the coverage footprint of the preamble. Hence, the Preamble thermal noise at the pixel, subscriber, or mobile Mi covered by the preamble is reduced by a factor of f Segment = 1 --- . 3 The following table shows the different types of subcarriers and their numbers for preamble transmission in WiMAX. N SCa – Total
128
512
1024
2048
Guard Subcarriers
DC Subcarrier
N SCa – Preamble
All
1 (54)
107
1
0
1 (54)
35
0.3271
None
36
0.3364
2
None
36
0.3364
All
1 (214)
428
1
0
None
143
0.3341
1 (214)
142
0.3318
2
None
143
0.3341
All
1 (426)
851
1
0
1 (426)
283
0.3325
None
284
0.3337
2
None
284
0.3337
All
1 (852)
1703
1
0
1 (852)
567
0.3329
None
568
0.3335
None
568
0.3335
Segment
Left
10
1
42
1
86
1
172
1
Right
10
41
86
172
2
Total
20
83
172
344
Preamble
f Segment
The preamble noise is the sum of the thermal noise and the noise figure of the terminal used for the calculations by the pixel, subscriber, or mobile Mi. TX i ic
TX i ic
n Preamble = n 0 – Preamble + nf
Mi
Output •
TX i ic
n Preamble : Preamble noise for the cell TXi(ic).
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10.4.2.3 Preamble Interference Calculation The interference received by any pixel, subscriber, or mobile, served by a cell TXi(ic) from other cells TXj(jc) can be defined as the preamble signal levels received from interfering cells TXj(jc) depending on the overlap that exists between the channels used by the cells TXi(ic) and TXj(jc) and which preamble carrier sets are used by the two cells. Input TX j jc
•
C Preamble : Preamble signal level received from an interfering cell TXj(jc) as calculated in "Preamble Signal Level Calculation" on page 707 at the pixel, subscriber, or mobile Mi covered by the cell TXi(ic).
•
M Shadowing – Model : Shadowing margin based on the model standard deviation.
•
M Shadowing – C I : Shadowing margin based on the C/I standard deviation. In Monte Carlo simulations, interfering signal levels already include M Shadowing – Model , as explained in "Preamble Signal Level Calculation" on page 679. In coverage predictions, the ratio M Shadowing – Model – M Shadowing – C I is applied to the interfering signals (for more information, see "Shadow Fading Model" on page 90). As the received interfering signal levels already include M Shadowing – Model , M Shadowing – C I is added to the received interfering signal levels in order to achieve the ratio M Shadowing – Model – M Shadowing – C I : TX jc j
TX jc j
C Preamble = C Preamble + M Shadowing – C I In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. TX i ic – TX j jc
•
rO
: Total channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 702.
•
N Seg
TX i ic
TX j jc
and N Seg
: Segment numbers assigned to the cells TXi(ic) and TXj(jc) calculated from their respective TX i ic
TX j jc
preamble indexes ( n Preamble and n Preamble ) as follows:
•
Inter – Tech
f IRF
n Preamble
N Seg
0 to 31, 96, 99, 102, 105, 108, 111
0
32 to 63, 97, 100, 103, 106, 109, 112
1
64 to 95, 98, 101, 104, 107, 110, 113
2
: Inter-technology interference reduction factor.
Calculations The received preamble interference (dBm) from any cell TXj(jc) is calculated for a pixel, subscriber, or mobile Mi as follows: TX j jc
TX j jc
TX i ic – TX j jc
I Preamble = C Preamble + f O TX ic – TX jc i j
Where f O
TX i ic – TX j jc
Inter – Tech
+ f Seg – Preamble + I DL
is the interference reduction factor due to channel overlap between the cells TXi(ic) and TXj(jc),
calculated as follows: TX i ic – TX j jc
fO
TX i ic – TX j jc
= 10 Log r O
TX i ic – TX j jc
f Seg – Preamble is the interference reduction factor due to preamble segmentation, calculated as follows: TX i ic – TX j jc
TX i ic – TX j jc
f Seg – Preamble = 10 Log p Collision
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The probability of preamble subcarrier collision p Collision TX ic i
1 if N Seg
TX jc j
= N Seg
TX ic i
between the cells TXi(ic) and TXj(jc) is 0 if N Seg
TX jc j
N Seg
and
. TX jc j
TX jc j
In case of smart antennas, C Preamble in I Preamble already includes the effect of the TX
j
number of antenna elements ( E SA ). If you wish to include the effect of the number of antennas in case of MIMO, you must add the following lines in the Atoll.ini file: [WiMAX] MultiAntennaInterference When the multi-antenna interference option is active, and TXj(jc) does not have a smart antenna equipment assigned, the interference is incremented by TX jc
j + 10 Log N Ant – TX . TX j jc
Where N Ant – TX is the number of MIMO transmission (downlink) antennas defined for the cell TXj(jc).
Inter – Tech
I DL
is the inter-technology downlink interference from transmitters of an external network (linked document of any
technology) calculated as follows: Inter – Tech
I DL
=
TX – External
EIRP DL
– L Path – L Indoor + G
Mi
–L
Mi
Mi
Mi
Inter – Tech
– L Ant – L Body – f IRF
All External TXs TX – External
Where EIRP DL
is the downlink EIRP of the external transmitter, L Path is the path loss from the external transmitters
to the pixel, subscriber, or mobile location, L Indoor is the indoor losses taken into account when the option "Indoor coverage" is selected, L
Mi
is the receiver terminal losses for the pixel, subscriber, or mobile Mi, G
Mi
is the receiver terminal’s antenna
Mi
gain for the pixel, subscriber, or mobile Mi, L Ant is the receiver terminal’s antenna attenuation calculated for the pixel, Mi
subscriber, or mobile Mi, and L Body is the body loss defined for the service used by the pixel, subscriber, or mobile Mi. Calculation of the Downlink Inter-technology Interference The downlink inter-technology interference is calculated as follows: Inter – Tech I DL
TX k P DL – Rec -------------------------------------- = F TX ic TX i k TX k ICP DL
TX k
Here P DL – Rec is the received downlink power from an interfering cell TXk belonging to another technology, and F TX i ic TX k
ICPDL
is the inter-technology downlink channel protection ratio for a frequency offset F between the interfered
and interfering frequency channels of TXi(ic) and TXk. TX k
P DL – Rec is calculated based on the EIRP from GSM cells, total power from UMTS, CDMA2000, and TD-SCDMA cells, maximum power from LTE cells, preamble power from WiMAX cells, and downlink cell power from Wi-Fi cells. Output •
TX j jc
I Preamble : Preamble interference received from any interfering cell TXj(jc) at the pixel, subscriber, or mobile Mi covered by a cell TXi(ic).
•
Inter – Tech
I DL
: Downlink inter-technology interference.
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10.4.2.4 Preamble C/N Calculation Input •
TX ic i
C Preamble : Received preamble signal level from the cell TXi(ic) as calculated in "Preamble Signal Level Calculation" on page 707. TX i ic
•
n Preamble : Preamble noise for the cell TXi(ic) as calculated in "Preamble Noise Calculation" on page 708.
•
G Div – Preamble : Preamble diversity gain defined in the WiMAX equipment of the terminal used by the pixel, subscriber,
Mi
or mobile Mi. •
DL
G Div : Additional downlink diversity gain defined for the clutter class where the pixel, subscriber, or mobile Mi is located.
Calculations The preamble C/N for a cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX i ic
TX i ic
TX i ic
Mi
DL
CNR Preamble = C Preamble – n Preamble + G Div – Preamble + G Div The preamble diversity gain is applied to the preamble C/N when the cell and the terminal both support any form of MIMO in downlink. The additional downlink diversity gain defined per clutter is also applied. Output •
TX i ic
CNR Preamble : Preamble C/N from the cell TXi(ic) at any pixel, subscriber, or mobile Mi.
10.4.2.5 Preamble C/(I+N) Calculation The carrier signal to interference and noise ratio is calculated in three steps. First Atoll calculates the received preamble signal level from the studied cell (as explained in "Preamble Signal Level Calculation" on page 707) at the pixel, subscriber or mobile under study. Next, Atoll calculates the interference received at the same studied pixel, subscriber, or mobile from all the interfering cells (as explained in "Preamble Interference Calculation" on page 710). Interference from each cell is weighted according to the co- and adjacent channel overlap between the studied and the interfering cells, and the probabilities of subcarrier collision. Finally, Atoll takes the ratio of the preamble signal level, and the sum of the total interference from all interfering cells and the noise (as calculated in "Preamble Noise Calculation" on page 708). The receiver terminal is always considered to be oriented towards its best server, except when the "Lock Status" is set to "Server+Orientation" for a subscriber in a subscriber list and its azimuth and tilt manually edited. In the case of NLOS between the receiver and the best server, Atoll does not try to find the direction of the strongest signal, the receiver is oriented towards the best server just as in the case of LOS. Input •
TX i ic
C Preamble : Preamble signal level received from the cell TXi(ic) at a pixel, subscriber, or mobile Mi as calculated in "Preamble Signal Level Calculation" on page 707. TX i ic
•
n Preamble : Preamble noise for the cell TXi(ic) as calculated in "Preamble Noise Calculation" on page 708.
•
I Preamble : Preamble interference received from any cell TXj(jc) at a pixel, subscriber, or mobile Mi covered by a cell
TX j jc
TXi(ic) as calculated in "Preamble Interference Calculation" on page 710. Inter – Tech
•
NRDL
•
G Div – Preamble : Preamble diversity gain defined in the WiMAX equipment of the terminal used by the pixel, subscriber,
M
: Inter-technology downlink noise rise.
i
or mobile Mi. •
DL
G Div : Additional downlink diversity gain defined for the clutter class where the pixel, subscriber, or mobile Mi is located.
•
712
Inter – Tech
I DL
: Downlink inter-technology interference as calculated in "Preamble Interference Calculation" on page 710.
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Calculations The preamble C/(I+N) for a cell TXi(ic) is calculated as follows at any pixel, subscriber, or mobile Mi: TX ic
TX ic i
CINR Preamble
i TX j jc n Preamble IPreamble ----------------------------- TX ic M i Inter – Tech DL 10 - -------------------------- + NR Inter – Tech + G i = C Preamble – 10 Log + I DL + 10 10 DL Div – Preamble + G Div 10 All TX j jc
The preamble diversity gain is applied to the preamble C/(I+N) when the cell and the terminal both support any form of MIMO. The additional downlink diversity gain defined per clutter is also applied. The preamble total noise (I+N) for a cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX ic
TX i ic
I + N Preamble
i TXj jc n Preamble IPreamble ----------------------------- Inter – Tech 10 - + NRInter – Tech --------------------------= 10 Log +I + 10 10 DL 10 DL All TXj jc
Output TX i ic
•
CINR Preamble : Preamble C/(I+N) from the cell TXi(ic) at a pixel, subscriber, or mobile Mi.
•
I + N Preamble : Preamble total noise from the interfering cells TXj(jc) at the pixel, subscriber, or mobile Mi covered
TX i ic
by a cell TXi(ic).
10.4.3 Best Server Determination In WiMAX, best server refers to a cell ("serving transmitter"-"reference cell" pair) from which a pixel, subscriber, or mobile Mi gets the highest preamble signal level or preamble C/(I+N). This calculation also determines whether the pixel, subscriber, or mobile Mi is within the coverage area of any transmitter or not. Input •
TX i ic
C Preamble : Preamble signal level received from any cell TXi(ic) at a pixel, subscriber, or mobile Mi as calculated in "Preamble Signal Level Calculation" on page 707 using the terminal and service parameters ( L M
Mi
, G
Mi
Mi
, L Ant , and
i
L Body ) of Mi. "Preamble C/(I+N) Calculation" on page 712 •
TX i ic
CINR Preamble : Preamble C/(I+N) received from any cell TXi(ic) at a pixel, subscriber, or mobile Mi as calculated in "Preamble C/(I+N) Calculation" on page 712.
Calculations The best server of any pixel, subscriber, or mobile Mi, BS M , is the cell from which the received preamble signal level or C/ i
(I+N) is the highest among all the cells. The best server is determined as follows: BSM = TX i ic i
TX i ic
TX i ic C Preamble = Best C All TX i ic Preamble
or BS M = TX i ic i
TX i ic TX i ic CINR Preamble = Best CINR Preamble All TX i ic
Here ic is the cell of the transmitter TXi with the highest preamble power. However, if more than one cell of the same transmitter covers the pixel, subscriber, or mobile, the final reference cell ic might be different from the initial cell ic (the one with the highest power) depending on the serving cell selection method: •
•
Random: In coverage prediction calculations and in calculations on subsriber lists, the cell of the highest priority layer is selected as the serving (reference) cell. In Monte Carlo simulations, a random cell is selected as the serving (reference) cell. Distributive: In coverage prediction calculations and in calculations on subsriber lists, the cell of the highest priority layer is selected as the serving (reference) cell. In Monte Carlo simulations, mobiles are distributed among cell layers one by one, i.e., if more than one cell layer covers a set of mobiles, the first mobile is assigned to the highest priority layer, the 2nd mobile to the second highest priority layer, and so on.
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When using either the Random or the Distributive cell selection method, the reference cell once assigned to a mobile does not change during Monte Carlo simulations. Output •
BS M : Best serving cell of the pixel, subscriber, or mobile Mi. i
10.4.4 Service Area Calculation In WiMAX, a pixel, subscriber, or mobile Mi can be covered by a cell (as calculated in "Best Server Determination" on page 713) but can be outside the service area. A pixel, subscriber, or mobile Mi is said to be within the service area of its best serving cell TXi(ic) if the preamble C/N from the cell at the pixel, subscriber, or mobile is greater than or equal to the preamble C/N threshold defined for the cell. Input •
TX i ic
CNR Preamble : Preamble C/N from the cell TXi(ic) at a pixel, subscriber, or mobile Mi as calculated in "Preamble C/N Calculation" on page 712.
•
TX i ic
T Preamble : Preamble C/N threshold defined for the cell TXi(ic).
Calculations A pixel, subscriber, or mobile Mi is within the service area of its best serving cell TXi(ic) if: TX ic i
TX ic i
CNR Preamble T Preamble Output • •
True: If the calculation criterion is satisfied. False: Otherwise.
10.4.5 Permutation Zone Selection In order to be able to calculate the traffic C/(I+N) and the throughputs, a permutation zone is assigned to each pixel, subscriber, or mobile Mi located within the service area (as calculated in "Service Area Calculation" on page 714) of its best serving cell. The permutation zone assigned to Mi is one which covers Mi in terms of distance and preamble C/N or C/(I+N), and accepts user speeds equal to or higher than Mi’s speed selected for the calculation. A pixel, subscriber, or mobile Mi which is unable to get a permutation zone is considered to be outside the service area. Input TX i ic
•
d Max – PZ : Maximum distance covered by a permutation zone of a cell TXi(ic).
•
QT PZ
TX ic i
: Minimum preamble C/N or C/(I+N) required at the pixel, subscriber, or mobile Mi to connect to a
permutation zone of a cell TXi(ic). TX i ic
•
Speed Max – PZ : Maximum speed supported by a permutation zone of a cell TXi(ic).
•
d
•
TX ic i CNR Preamble
M – TX ic i i
: Distance between the pixel, subscriber, or mobile Mi and a cell TXi(ic). : Preamble C/N from the cell TXi(ic) as calculated in "Preamble C/N Calculation" on page 712.
TX i ic
•
CINR Preamble : Preamble C/(I+N) from the cell TXi(ic) as calculated in "Preamble C/(I+N) Calculation" on page 712.
•
Mobility M i : Speed of the pixel, subscriber, or mobile Mi.
Calculations Mi is assigned the permutation zone with the highest priority among the permutation zones whose selection criteria Mi satisfies. Mi satisfies the selection criteria of a permutation zone if: •
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The distance between Mi and TXi(ic) is less than or equal to the maximum distance covered by the permutation zone:
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d •
M – TX ic i i
TX ic i
d Max – PZ
The preamble C/N or C/(I+N) at Mi is better than or equal to the quality threshold defined for the permutation zone: TX ic i
TX ic i
CNR Preamble QT PZ •
TX ic i
TX ic i
or CINR Preamble QT PZ
The mobility of Mi is less than or equal to the maximum mobile speed supported by the permutation zone: TX i ic
Mobility M i Speed Max – PZ Therefore, the permutation zones assigned to a pixel, subscriber, or mobile Mi in the downlink and uplink are:
Mi
PZ DL
Mi
PZ UL
TX ic i = Highest Priority PZ DL
TX i ic TX i ic CNR QT Preamble PZ TX i ic TX i ic M i – TX i ic d Max – PZ AND AND Mobility M i Speed Max – PZ OR d TX i ic TX i ic CINR QT
TX ic i = Highest Priority PZ UL
TX i ic TX i ic CNR QT Preamble PZ TX i ic TX i ic M i – TX i ic d d AND AND Mobility M Speed OR Max – PZ i Max – PZ TX ic TX ic i CINR i QT
Preamble
Preamble
PZ
PZ
If more than 1 permutation zone satisfies the distance, speed, and quality threshold criteria, and all have the same priority, the permutation zone assigned to the pixel, subscriber, or mobile will be the first in the list of permutation zones (frame configuration) among these zones. Output •
Mi
Mi
PZ DL and PZ UL : Downlink and uplink permutation zones assigned to the pixel, subscriber, or mobile Mi.
10.4.6 Traffic and Pilot Signal Level and Quality Calculations Traffic and pilot subcarriers can be transmitted with different transmission powers than the preamble power of a cell, and do not suffer the same interference and noise as the preamble. The following sections describe how traffic and pilot signal levels, noise and interference, C/N, and C/(I+N) ratios are calculated on the downlink and uplink. • • • • • • • • • •
"Traffic and Pilot Signal Level Calculation (DL)" on page 715. "Traffic and Pilot Noise Calculation (DL)" on page 717. "Traffic and Pilot Interference Calculation (DL)" on page 718. "Traffic and Pilot C/N Calculation (DL)" on page 726. "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 727. "Traffic Signal Level Calculation (UL)" on page 729. "Traffic Noise Calculation (UL)" on page 730. "Traffic Interference Calculation (UL)" on page 731. "Traffic C/N Calculation (UL)" on page 734. "Traffic C/(I+N) and Bearer Calculation (UL)" on page 737.
10.4.6.1 Traffic and Pilot Signal Level Calculation (DL) Input TX i ic
•
P Preamble : Preamble transmission power of the cell TXi(ic).
•
P Traffic : Traffic power reduction of the cell TXi(ic).
TX i ic
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TX ic i
•
P Pilot : Pilot power reduction of the cell TXi(ic).
•
G
TX
i
: Transmitter antenna gain for the antenna used by the transmitter TXi.
•
Without smart antennas: G
•
With smart antennas: G G
TX i
TX i
TX
i
is the transmitter antenna gain, i.e., G
TX
i
TX
i
= G Ant .
is the smart antenna gain in the direction of the pixel, subscriber, or mobile Mi, i.e.,
= G SA . Where is the direction in which Mi is located. For more information on the calculation of
G SA , refer to section "Beamforming Smart Antenna Models" on page 43. •
Array G SA
•
G SA
•
G SA : Smart antenna diversity gain (for cross-polarised smart antennas) defined per clutter class.
•
L
•
L Path : Path loss ( L Path = L Model + L Ant ).
•
L Model : Loss on the transmitter-receiver path (path loss) calculated using a propagation model.
•
L Ant : Antenna attenuation (from antenna patterns) calculated for the antenna used by the transmitter TXi.
•
M Shadowing – Model : Shadowing margin based on the model standard deviation.
: Smart antenna array gain offset defined per clutter class.
Combining
: Smart power combining gain offset defined per clutter class.
Div
TX i
: Total transmitter losses for the transmitter TXi ( L TX
TX i
= L Total – DL ).
i
TX i
In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. •
L Indoor : Indoor losses taken into account when the option "Indoor coverage" is selected.
•
L
Mi
G
•
Mi
: Receiver terminal losses for the pixel, subscriber, or mobile Mi. : Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi.
Mi
L Ant : Receiver terminal’s antenna attenuation calculated for the pixel, subscriber, or mobile Mi.
•
Mi
For calculating the useful signal level from the best serving cell, L Ant is determined in the direction (H,V) = (0,0) from Mi
the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, L Ant is determined in the direction of the interfering cell from the antenna patterns of the antenna used by Mi, while the antenna is pointed towards Mi’s best serving cell. Mi
•
L Body : Body loss defined for the service used by the pixel, subscriber, or mobile Mi.
Calculations The received traffic and pilot signal levels (dBm) from any cell TXi(ic) are calculated for a pixel, subscriber, or mobile Mi as follows: TX i ic
TX i ic
Mi
TX i ic
Mi
C Traffic = EIRP Traffic – L Path – M Shadowing – Model – L Indoor + G TX i ic
C Pilot
= EIRP Pilot – L Path – M Shadowing – Model – L Indoor + G
–L –L
Mi
Mi
Mi
Mi
Mi
Mi
– L Ant – L Body and – L Ant – L Body
Where EIRP is the effective isotropic radiated power of the cell calculated as follows: TX i ic
TX i ic
TX i
TX i ic
TX i
EIRP Traffic = P Traffic + G TX i ic
EIRP Pilot
= P Pilot + G
TX ic i
TX ic i
With P Traffic and P Pilot TX ic i
TX ic i
Array
+ G SA
Array
+ G SA
+ G SA + G SA
TX i
Div
TX i
+ G SA – L
Combining
+ G SA – L
and
being the traffic and pilot transmission powers of the cell TXi(ic) calculated as follows: TX ic i
TX ic i
P Traffic = P Preamble – P Traffic and P Pilot
716
Div
Combining
TX ic i
TX ic i
= P Preamble – P Pilot
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If you wish to exclude the the energy corresponding to the cyclic prefix part of the total symbol duration from the useful signal level, you must add the following lines in the Atoll.ini file: [WiMAX] ExcludeCPFromUsefulPower = 1 TX i ic
When this option is active, the cyclic prefix energy is excluded from C Preamble . In other TX i ic
words, the factor 10 Log 1 – r CP
TX ic
is added to C i Preamble . Independant of the option, interference levels are calculated for the total symbol durations, i.e., the energy of the useful symbol duration and the cyclic prefix energy. Output TX i ic
•
C Traffic : Received traffic signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
C Pilot : Received pilot signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
TX i ic
10.4.6.2 Traffic and Pilot Noise Calculation (DL) For determining the traffic and pilot C/N and C/(I+N), Atoll calculates the downlink noise over the channel bandwidth used by the cell. The used bandwidth depends on the number of used subcarriers. The numbers of subcarriers used by different permutation zones can be different. The downlink noise comprises thermal noise and the noise figure of the equipment. The thermal noise density depends on the temperature, i.e., it remains constant for a given temperature. However, the value of the thermal noise varies with the used bandwidth. Input • •
K: Boltzmann’s constant. T: Temperature in Kelvin. M i PZ DL
•
N SCa – Used : Number of subcarriers used by the downlink permutation zone of a cell TXi(ic) assigned to Mi.
•
N SCa – Total : Total number of subcarriers defined for the frame configuration of a cell TXi(ic).
•
F Sampling : Sampling frequency for the cell TXi(ic) as calculated in "Calculation of Sampling Frequency" on page 740.
•
nf
TX i ic
TX i ic M
i
: Noise figure of the terminal used for calculations by the pixel, subscriber, or mobile Mi.
Calculations The power spectral density of thermal noise is calculated as follows: n 0 = 10 Log K T 1000 = – 174 dBm/Hz The thermal noise for a cell is calculated as: Mi
TX i ic
n 0 – DL
PZ DL N SCa – Used TXi ic = n 0 + 10 Log F Sampling ------------------------ TX i ic N SCa – Total
The downlink noise is the sum of the thermal noise and the noise figure of the terminal used for the calculations by the pixel, subscriber, or mobile Mi. TX i ic
n DL
TX i ic
= n 0 – DL + nf
Mi
Effect of Segmentation: If you select downlink segmentation support for the frame configuration used by the cell, it means that the first downlink PUSC permutation zone is segmented. All other zones are pooled together to form a non-segmented zone. The downlink segmenting factor, f Segment – DL , is calculated from the number of secondary subchannel groups assigned to the permutation zone in the Permutation Zones table.
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PSG + 2 SSGf Segment – DL = 3 -------------------------------------------15 Where, PSG is the number of primary subchannel groups and SSG is the number of used secondary subchannel groups. The multiplicative coefficients of 3 and 2 are derived from the ratio of the numbers of subchannels that belong to the primary and to the secondary subchannel gourps. For example, for the FFT size of 1024 (or 2048), each primary subchannel group contains 6 (or 12) subchannels, and each secondary subchannel group contains 4 (or 8) subchannels, which gives the ratio of 3:2. And, the denominator of 15 = 3 x 3 + 2 x 3. f Segment – DL represents the fraction of the channel bandwidth used by a downlink segment. The power transmitted 1 over a segment has ---------------------------- times the spectral density of the power transmitted over the entire channel f Segment – DL 1 bandwidth. When calculating the downlink C/N and C/(I+N) ratios, the increase in power by ---------------------------- due to this f Segment – DL power concentration is equivalent to a reduction in the noise level by f Segment – DL . Hence, if downlink segmentation is used, the thermal noise power at the pixel, subscriber, or mobile Mi covered by the downlink segmented permutation zone is reduced by the factor f Segment – DL . Which means that the thermal noise for the a segment of the channel used by a cell is calculated as: Mi
TX i ic
n 0 – DL
PZ DL TX i ic N SCa – Used = n 0 + 10 Log FSampling ------------------------ f Segment – DL TX i ic N SCa – Total
Output •
TX i ic
n DL
: Downlink noise for the cell TXi(ic).
10.4.6.3 Traffic and Pilot Interference Calculation (DL) The interference received by any pixel, subscriber, or mobile, served by a cell TXi(ic) from other cells TXj(jc) can be defined as the traffic and pilot signal levels received from interfering cells TXj(jc) depending on the overlap that exists between the channels used by the cells TXi(ic) and TXj(jc), on the traffic loads of the interfering cells TXj(jc), and whether the cells use downlink segmentation or not. Moreover, the interference can come from cells using simple as well as smart antennas. The calculation can be divided into the two parts. • •
10.4.6.3.1
"Traffic and Pilot Interference Signal Levels Calculation (DL)" on page 718. "Effective Traffic and Pilot Interference Calculation (DL)" on page 722.
Traffic and Pilot Interference Signal Levels Calculation (DL) The traffic and pilot signal levels received from interfering cells TXj(jc) at a pixel, subscriber, or mobile Mi, covered by a cell TXi(ic), are calculated in a different manner than the traffic and pilot signal levels from the studied cell TXi(ic). This section explains how these interfering signals are calculated. Input
718
TX j jc
•
P Preamble : Preamble transmission power of the cell TXj(jc).
•
P Pilot : Pilot power reduction of the interfering cell TXj(jc).
•
P Traffic : Traffic power reduction of the interfering cell TXj(jc).
•
P Idle – Pilot : Idle pilot power reduction of the interfering cell TXj(jc).
•
L
TX j jc TX j jc TX j jc
TX
j
: Total transmitter losses for the transmitter TXj ( L
TX
j
= L Total – DL ).
TX j
•
L Path : Path loss ( L Path = L Model + L Ant ).
•
L Model : Loss on the transmitter-receiver path (path loss) calculated using a propagation model.
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j
•
L Ant : Antenna attenuation (from antenna patterns) calculated for the antenna used by the transmitter TXj.
•
M Shadowing – Model : Shadowing margin based on the model standard deviation.
•
M Shadowing – C I : Shadowing margin based on the C/I standard deviation. In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected.
•
L Indoor : Indoor losses taken into account when the option "Indoor coverage" is selected.
•
L
• •
Mi
G
: Receiver terminal losses for the pixel, subscriber, or mobile Mi.
Mi
: Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi.
Mi
L Ant : Receiver terminal’s antenna attenuation calculated for the pixel, subscriber, or mobile Mi. M
i
L Ant is determined in the direction of TXj(jc) from the antenna patterns of the antenna used by Mi while the antenna is pointed towards TXi(ic). Mi
•
L Body : Body loss defined for the service used by the pixel, subscriber, or mobile Mi.
•
TL DL
TX jc j
: Downlink traffic load of the interfering cell TXj(jc).
Traffic loads can either be calculated using Monte Carlo simulations, or entered manually for each cell. Calculation of traffic loads is explained in "Simulation Process" on page 699. •
TX jc j
AU DL
: Downlink AAS usage ratio of the interfering cell TXj(jc).
Downlink AAS usage ratios are calculated using Monte Carlo simulations as explained in "Simulation Process" on page 699. •
TX j jc
N SCa – Used : Number of used subcarriers defined for the first downlink permutation zone in the frame configuration assigned to the interfering cell TXj(jc).
•
TX j jc
N SCa – Data : Number of data subcarriers defined for the first downlink permutation zone in the frame configuration assigned to the interfering cell TXj(jc).
Calculations WiMAX cells can transmit different powers on pilot (NUsed – NData) and data (NData) subcarriers for the part of the frame with traffic, and a different pilot power for the part of the frame that does not have traffic bursts. Data subcarriers are off during the empty part of the frame. Therefore, the interference received from a cell depends on the traffic load and the different powers of the cell, i.e., pilot, traffic, and idle pilot powers. Monte Carlo simulations and coverage prediction calculations present different scenarios for interference calculations in the case of smart antennas. •
Monte Carlo Simulations: In the case of Monte Carlo simulations, the interferer is either using the transmitter antenna or the smart antenna at any given moment. So, for each interfered pixel, subscriber, or mobile, Atoll already knows the type of the interference source. Therefore, the interference received from any cell TXj(jc) can be given by: TX jc
TX j jc
Without smart antennas: I Total
TX jc
j I j I Non – AAS Idle ---------------------------------------------- 10 10 + 10 = 10 Log 10 TX jc
With smart antennas:
•
TX jc j I Total
I j AAS - -----------------10 = 10 Log 10
Coverage Predictions:
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In the case of coverage prediction calculations, the interferer could either be transmitting using the transmitter antenna, or using the smart antenna, or it could be empty, or not transmitting.Therefore, the interference received from any cell TXj(jc) can be given by: TX jc
TX jc
TX jc
j j I j I I Non – AAS Idle AAS ---------------------------------------------------------------- 10 10 10 + 10 + 10 = 10 Log 10
TX jc j
I Total
Where, the three components of the interference are: TX j jc
•
I Non – AAS : Interference from the loaded part of the frame transmitted using the main antenna,
•
I AAS
•
I Idle
TX jc j TX j jc
: Interference from the loaded part of the frame transmitted using the smart antenna, : Interference from the empty, or idle, part of the frame.
The above components of the interference are calculated as follows: The interference from the loaded part of the frame transmitted using the main antenna is calculated as follows: The received interfering traffic and pilot signal levels (dBm) from any cell TXj(jc) are calculated for a pixel, subscriber, or mobile Mi as follows: In Monte Carlo simulations: TX j jc
TX j jc
Mi
TX j jc
Mi
I Traffic = EIRP Traffic – L Path – M Shadowing – Model – L Indoor + G TX j jc
= EIRP Pilot – L Path – M Shadowing – Model – L Indoor + G
I Pilot
–L –L
Mi
Mi
Mi
Mi
Mi
Mi
– L Ant – L Body – L Ant – L Body
In coverage prediction: TX j jc
TX j jc
Mi
TX j jc
Mi
I Traffic = EIRP Traffic – L Path – M Shadowing – Model + M Shadowing – C I – L Indoor + G TX j jc
= EIRP Pilot – L Path – M Shadowing – Model + M Shadowing – C I – L Indoor + G
I Pilot
–L –L
Mi
Mi
Mi
Mi
Mi
Mi
– L Ant – L Body – L Ant – L Body
Where EIRP is the effective isotropic radiated power of the cell calculated as follows: TX j jc
TX j jc
EIRP Traffic = P Traffic + G TX j jc
TX j jc
With P Traffic and P Pilot TX jc j
TX jc j
TX j
–L
TX j
TX j jc
and EIRP Pilot
TX j
TX j
–L
TX j
being the traffic and pilot transmission powers of the cell TXj(jc) calculated as follows: TX jc j
TX jc j
P Traffic = P Preamble – P Traffic and P Pilot And G
TX j jc
= P Pilot + G
TX jc j
TX jc j
= P Preamble – P Pilot
TX j
= G Ant , i.e., the transmitter antenna gain for the antenna used by the transmitter TXj.
The interference from the loaded part of the frame transmitted using the main antenna is given as: TX jc
TX j jc
I Non – AAS
TX jc
j I j I Pilot TX j jc TX j jc Traffic ------------------ TX jc ------------------ TX jc N N j j 10 10 SCa – Data SCa – Data - + 10 ----------------------- 1 – ------------------------- 1 – AU DL 10 = 10 Log TL DL TX j jc TX j jc N SCa – Used N SCa – Used
If you wish to include the effect of the number of antennas in case of MIMO, you must add the following lines in the Atoll.ini file: [WiMAX] MultiAntennaInterference = 1 When the multi-antenna interference option is active, the interference is incremented by TX jc
TX jc
j j + 10 Log N Ant – TX . Where N Ant – TX is the number of MIMO transmission (downlink) antennas defined for the cell TXj(jc).
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The interference from the loaded part of the frame transmitted using the smart antenna is calculated as follows: The received interfering traffic signal level (dBm) from any cell TXj(jc) is calculated for a pixel, subscriber, or mobile Mi as follows: In Monte Carlo simulations: TX j jc
I AAS
TX j jc
= EIRPAAS
– L Path – M Shadowing – Model – L Indoor + G
Mi
–L
Mi
Mi
Mi
– L Ant – L Body
In coverage prediction: TX j jc
I AAS
TX j jc
= EIRPAAS
– L Path – M Shadowing – Model + M Shadowing – C I – L Indoor + G
Mi
–L
Mi
Mi
Mi
– L Ant – L Body
Where EIRP is the effective isotropic radiated power of the cell calculated as follows: TX j jc
EIRP AAS
TX j jc
= P Traffic + G
TX j
–L
TX j
TX j jc
With P Traffic being the traffic transmission power of the cell TXj(jc) calculated as follows: TX j jc
TX j jc
TX j jc
P Traffic = P Preamble – P Traffic And, G
TX j
= G SA is the smart antenna gain in the direction of the victim mobile Mi, calculated from the angular
distributions of the downlink traffic power density of the interfering cells. The angular distribution of the downlink traffic power density is determined from the array correlation matrices calculated during Monte Carlo simulations. is the direction in which the victim pixel, subscriber, or mobile Mi is located. For more information on the calculation of G SA , see "Beamforming Smart Antenna Models" on page 43. The gain of the interfering signal, G SA , transmitted in the direction of each pixel is given by: H
G SA = g n S R Avg S Where S is the steering vector in the direction (probe mobile/pixel), H denotes the Hilbert transform, R Avg is the average array correlation matrix, and g n is the gain of the nth antenna element in the direction . The interference from the empty, or idle, part of the frame transmitted using the transmitter antenna is calculated as follows: The received interfering pilot signal level (dBm) from any cell TXj(jc) is calculated for a pixel, subscriber, or mobile Mi as follows: TX j jc
TX j jc
I Idle – Pilot = EIRP Idle – Pilot – L Path – L Indoor + G
Mi
–L
Mi
Mi
Mi
– L Ant – L Body
Where EIRP is the effective isotropic radiated power of the cell calculated as follows: TX j jc
TX j jc
EIRP Idle – Pilot = P Idle – Pilot + G
TX j
–L
TX j
TX j jc
With P Idle – Pilot being the idle pilot transmission power of the cell TXj(jc) calculated as follows: TX j jc
TX j jc
TX j jc
P Idle – Pilot = P Preamble – P Idle – Pilot And, G
TX j
TX j
= G Ant , i.e., the transmitter antenna gain for the antenna used by the transmitter TXj.
The interference from the empty, or idle, part of the frame transmitted using the transmitter antenna is given as: TX jc
TX j jc
I Idle
I j TX j jc Idle – Pilot ---------------------------- TX j jc N 10 SCa – Data 1 – -----------------------= 10 Log 1 – TL DL 10 TX j jc N SCa – Used
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If you wish to include the effect of the number of antennas in case of MIMO, you must add the following lines in the Atoll.ini file: [WiMAX] MultiAntennaInterference = 1 When the multi-antenna interference option is active, the interference is incremented by TX jc
TX jc
j j + 10 Log N Ant – TX . Where N Ant – TX is the number of MIMO transmission (downlink) antennas defined for the cell TXj(jc).
Output •
10.4.6.3.2
TX j jc
I Total : Interference received at the pixel, subscriber, or mobile Mi from any interfering cell TXj(jc).
Effective Traffic and Pilot Interference Calculation (DL) The effective downlink traffic and pilot interference received at a pixel, subscriber, or mobile Mi covered by a cell TXi(ic) from interfering cells TXj(jc) depends on the co- and adjacent channel overlap that exists between the channel used by the studied cell and the interfering cells, and the downlink segmentation parameters of the studied and interfering cells. The first downlink PUSC zone can be segmented at the studied and the interfering cells. The probability of subcarrier collision depends on the lengths of the segmented zones and on the subchannel groups used at both sides. Input •
TX j jc
I Total : Interference received at the pixel, subscriber, or mobile Mi from any interfering cell TXj(jc) as calculated in "Traffic and Pilot Interference Signal Levels Calculation (DL)" on page 718. TX i ic – TX j jc
•
: Total channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 702.
•
SU DL
rO
TX i ic
TX j jc
and SU DL
: Downlink segmentation usage ratios defined for cells TXi(ic) and TXj(jc).
Calculations The total traffic and pilot interference (dBm) from any cell TXj(jc) is calculated for a pixel, subscriber, or mobile Mi as follows: TX j jc
I DL
TX j jc
TX i ic – TX j jc
= I Total + f O
TX i ic – TX j jc
+ f Seg – DL
Inter – Tech
+ I DL
Calculations for the interference reduction factors due to channel overlapping and downlink segmentation are explained below: Interference reduction due to the co- and adjacent channel overlap between the studied and the interfering cells: Interference reduction due to the co- and adjacent channel overlap between the cells TXi(ic) and TXj(jc) is calculated as follows: TX i ic – TX j jc
fO
TX i ic – TX j jc
= 10 Log r O
Interference reduction due to downlink segmentation: If you select downlink segmentation support for the frame configuration that you are using, it means that the first zone in the downlink, i.e., the DL PUSC zone, is segmented. All other zones are pooled together to form a group of non-segmented zones. There are two effects of segmentation: 1. Power concentration, which means that the spectral density of the power transmitted over one segment is higher than the spectral density of the same power transmitted over the entire channel bandwidth. The effect of power concentration is visible when calculating the downlink C/(I+N). The power transmitted over a segmented zone has 1 --------------------------- times the spectral density of the power transmitted over the entire channel bandwidth. When f Segment – DL 1 calculating the C/(I+N) ratio, the increase in power by ---------------------------- is equivalent to decreasing the noise and f Segment – DL
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interference by f Segment – DL . Hence, if downlink segmentation is used, the interference received at the pixel, subscriber, or mobile Mi covered by the segmented zone is reduced by a factor of f Segment – DL . 2. Collision probability between the subcarriers used by the subchannels belonging to the segment of the studied cell and the subcarriers used by other sectors, segmented or not. The following paragraphs explain how the collision probability is calculated. The downlink segmentation usage (SU) ratio is the percentage of the total downlink traffic load present in the segmented downlink PUSC zone. For example, if the downlink traffic load is 80 %, and the downlink segmentation usage ratio is 50 %, then this means that the downlink traffic load of the segmented zone is 40 % (i.e., 50 % of 80 %), and the downlink traffic load of the non-segmented zones is 40 %. In coverage predictions, Atoll uses the downlink segmentation usage ratios stored in the cell properties for determining the interference. In simulations, Atoll resets the downlink segmentation usage ratios for all the cells to 0, and then calculates the downlink segmentation usage ratios according to the traffic loads of the mobiles allocated to the segmented zone and in the non-segmented zones.
Figure 10.3: Downlink Segmentation Atoll determines the switching point between the segmented and the non-segmented zones using the downlink segmentation usage ratio. The switching points between the segmented and non-segmented zones of the victim and interfering cells, TXi(ic) and TXj(jc) respectively, are calculated as follows: SP
SP
TX i ic
TX i ic
SU DL = ----------------------------------------------------------------------------------------------and TX i ic TX i ic TX i ic SU DL + f Segment – DL 1 – SU DL
TX j jc
SU DL = ----------------------------------------------------------------------------------------------TX j jc TX j jc TX j jc SU DL + f Segment – DL 1 – SU DL
TX jc j
Where, SP is the switching point between the segmented and the non-segmented zones, SU is the downlink segmentation usage ratios of the cells, and f Segment – DL is downlink segmenting factor, which gives the bandwidth used by a segment. The downlink segmenting factor, f Segment – DL , is calculated from the number of secondary subchannel groups assigned to the first downlink PUSC permutation zone in the Permutation Zones table. PSG + 2 SSGf Segment – DL = 3 -------------------------------------------15 Where, PSG is the number of primary subchannel groups and SSG is the number of secondary subchannel groups. The multiplicative coefficients of 3 and 2 are derived from the ratio of the numbers of subchannels that belong to the primary and to the secondary subchannel gourps. For example, for the FFT size of 1024 (or 2048), each primary subchannel group contains 6 (or 12) subchannels, and each secondary subchannel group contains 4 (or 8) subchannels, which gives the ratio of 3:2. And, the denominator of 15 = 3 x 3 + 2 x 3.
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If the downlink segmentation usage ratio is set to 0, it means that the segmented zone does not exist. Setting SU to 0 gives SP = 0, and setting SU to 1 gives SP = 1 (or 100%), which shows how the switching point varies with the downlink segmentation usage ratio. Derivation of the switching point formula: The downlink segmentation usage ratio is used to partition the total downlink traffic load into segmented and non-segmented zones. Therefore, the switching point formula is derived from the equation: SU DL TL DL 1 – SU DL TL DL -------------------------------------------------------------------- = ----------------------------------------------SP fSegment – DL W Channel 1 – SP W Channel With cells using downlink segmentation, there can be four different interference scenarios. • • • •
Between the segmented zone of the victim and the segmented zone of the interferer. Between the segmented zone of the victim and the non-segmented zone of the interferer. Between the non-segmented zone of the victim and the segmented zone of the interferer. Between the non-segmented zone of the victim and the non-segmented zone of the interferer.
Figure 10.4: Downlink Segmentation Interference Scenarios Therefore, Atoll calculates the probabilities of collision for each scenario and weights the total interference according to the total collision probability. The probability of collision p Coll for each scenario is given by the following formula: 3 PSG Com + 2 SSG Com p Coll = ---------------------------------------------------------------------TX i ic TX i ic 3 PSG + 2 SSG Where, PSGCom is the number of primary subchannel groups common in TXi(ic) and TXj(jc), SSGCom is the number of secondary subchannel groups common in TXi(ic) and TXj(jc), PSG in the cell TXi(ic), and SSG
TX i ic
TX i ic
is the number of primary subchannel groups
is the number of secondary subchannel groups in the cell TXi(ic).
The segment numbers and the cell permutation base numbers (Cell PermBase) are determined from the cell’s preamble index. The mapping between the preamble index, the segment number, and Cell PermBase is available in the IEEE specifications. This mapping is performed in Atoll as follows: Preamble Index ( PI ) Range: 0 to 113 Cell PermBase ( PB ) Range: 0 to 31 Segment Number ( N Seg ) Range: 0, 1, 2
PI 96
96 PI 114
PI Modulo 32
PI – 96
PI Floor ------ 32
PI – 96 Modulo 3
There can be 2 cases for calculating the total probability of collision.
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•
Case 1: If the pixel, subscriber, or mobile Mi is covered by the segmented zone of TXi(ic), the total collision probability for the pixel, subscriber, or mobile Mi is calculated as follows:
TX ic – TX jc i j
p Collision – DL
TX jc TX ic j i SS p Coll If SP SP TX jc TX ic TX jc = SS j i j SN + p Coll SP – SP TX j jc TX i ic p Coll SP ------------------------------------------------------------------------------------------------------------If SP SP TX i ic SP
Case 2: If the pixel, subscriber, or mobile Mi is covered by the non-segmented zone of TXi(ic), the total collision probability for the pixel, subscriber, or mobile Mi is calculated as follows:
•
TX i ic – TX j jc
p Collision – DL
TX j jc TX i ic NN p Coll If SP SP TX j jc TX jc TX ic + p NS SP j – SP i = p NN TX jc TX ic Coll 1 – SP Coll ---------------------------------------------------------------------------------------------------------------------------- If SP j SP i TX ic 1 – SP i
The interference reduction factor due to downlink segmentation for the pixel, subscriber, or mobile Mi is calculated as follows: TX i ic – TX j jc
f Seg – DL Inter – Tech
I DL
TX ic – TX jc
i j = 10 Log p Collision – DL
is the inter-technology downlink interference from transmitters of an external network (linked document of any
technology) calculated as follows: Inter – Tech
I DL
=
TX – External
EIRP DL
– L Path – L Indoor + G
M
i
–L
M
i
M
i
M
i
Inter – Tech
– L Ant – L Body – f IRF
All External TXs TX – External
Where EIRP DL
is the downlink EIRP of the external transmitter, L Path is the path loss from the external transmitters
to the pixel, subscriber, or mobile location, L Indoor is the indoor losses taken into account when the option "Indoor coverage" is selected, L
Mi
is the receiver terminal losses for the pixel, subscriber, or mobile Mi, G
Mi
is the receiver terminal’s antenna
Mi
gain for the pixel, subscriber, or mobile Mi, L Ant is the receiver terminal’s antenna attenuation calculated for the pixel, Mi
subscriber, or mobile Mi, and L Body is the body loss defined for the service used by the pixel, subscriber, or mobile Mi. Calculation of the Downlink Inter-technology Interference The downlink inter-technology interference is calculated as follows: Inter – Tech I DL
TX
TX k P DL – Rec --------------------------------------- = F TX i ic TX k TX ICP DL k
k
Here P DL – Rec is the received downlink power from an interfering cell TXk belonging to another technology, and F TX i ic TX k
ICPDL
is the inter-technology downlink channel protection ratio for a frequency offset F between the interfered
and interfering frequency channels of TXi(ic) and TXk. TX k
P DL – Rec is calculated based on the EIRP from GSM cells, total power from UMTS, CDMA2000, and TD-SCDMA cells, maximum power from LTE cells, preamble power from WiMAX cells, and downlink cell power from Wi-Fi cells. Output •
TX j jc
I DL
: Effective downlink traffic and pilot interference received at the pixel, subscriber, or mobile Mi from any
interfering cell TXj(jc). •
Inter – Tech
I DL
: Downlink inter-technology interference.
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10.4.6.4 Traffic and Pilot C/N Calculation (DL) Input •
TX ic i
C Traffic : Received traffic signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Traffic and Pilot Signal Level Calculation (DL)" on page 715.
•
TX i ic
C Pilot : Received pilot signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Traffic and Pilot Signal Level Calculation (DL)" on page 715.
•
TX i ic
n DL
: Downlink noise for the cell TXi(ic) as calculated in "Traffic and Pilot Noise Calculation (DL)" on page 717.
TX i ic
•
T AMS : AMS threshold defined for the cell TXi(ic).
•
T B : Bearer selection thresholds of the bearers defined in the WiMAX equipment used by Mi’s terminal.
•
B DL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
M
i
Mi
or mobile Mi. •
M
i
B DL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber, or mobile Mi. TX i ic
•
N Ant – TX : Number of MIMO transmission (downlink) antennas defined for the cell TXi(ic).
•
N Ant – RX : Number of MIMO reception (downlink) antennas defined for the terminal used by the pixel, subscriber, or
Mi
mobile Mi. •
Mobility M i : Mobility used for the calculations.
•
Subchannel allocation mode used by the downlink permutation zone PZ DL assigned to the pixel, subscriber, or mobile
Mi
Mi as calculated in "Permutation Zone Selection" on page 714. •
M
i BLER BDL : Downlink block error rate read from the graphs available in the WiMAX equipment assigned to the terminal used by the pixel, subscriber, or mobile Mi.
Calculations The traffic and pilot C/N for a cell TXi(ic) are calculated as follows for any pixel, subscriber, or mobile Mi: TX ic i
TX ic i
TX ic i
TX i ic
TX i ic
CNR Traffic = C Traffic – n DL TX i ic
CNR Pilot
= C Pilot – n DL
Bearer Determination: The bearers available for selection in the pixel, subscriber, or mobile Mi’s WiMAX equipment are the ones: •
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
•
Whose selection thresholds are less than the traffic or pilot C/N at Mi: T B CNR Traffic or T B CNR Pilot
Mi
TX i ic
Mi
TX i ic
Mi
If the cell supports MIMO, the STTD/MRC or SU-MIMO diversity gain, G Div – DL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the WiMAX equipment assigned to the TX i ic
Mi
Mi
pixel, subscriber, or mobile Mi for N Ant – TX , N Ant – RX , the subchannel allocation mode of PZ DL , Mobility M i , M
i BLER B DL .
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DL
The additional diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the WiMAX equipment for which the following is true: M
i
DL
TX ic i
Mi
DL
TX i ic
M
i
T B – G Div – DL – G Div CNR Traffic Mi
T B – G Div – DL – G Div CNR Pilot
The bearer selected for data transfer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic). •
Bearer Index From among the bearers available for selection, the selected bearer is the one with the highest index.
•
Peak MAC Throughput From among the bearers available for selection, the selected bearer is the one with the highest downlink peak MAC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743.
•
Effective MAC Throughput From among the bearers available for selection, the selected bearer is the one with the highest downlink effective MAC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743.
MIMO – STTD/MRC and SU-MIMO Diversity Gain: Once the bearer is known, the traffic and pilot C/N calculated above become: TX i ic
TX i ic
Mi
DL
TX i ic
Mi
DL
CNR Traffic = CNR Traffic + G Div – DL + G Div TX i ic
CNR Pilot
= CNR Pilot + G Div – DL + G Div
Mi
Where G Div – DL is the STTD/MRC or SU-MIMO diversity gain corresponding to the selected bearer. Output TX ic i
•
CNR Traffic : Traffic C/N from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
CNR Pilot : Pilot C/N from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
TX i ic
10.4.6.5 Traffic and Pilot C/(I+N) and Bearer Calculation (DL) The carrier signal to interference and noise ratio is calculated in three steps. First Atoll calculates the received signal level from the studied cell (as explained in "Traffic and Pilot Signal Level Calculation (DL)" on page 715) at the pixel, subscriber, or mobile under study. Next, Atoll calculates the interference received at the same studied pixel, subscriber, or mobile from all the interfering cells (as explained in "Traffic and Pilot Interference Calculation (DL)" on page 718). Interference from each cell is weighted according to the co- and adjacent channel overlap between the studied and the interfering cells, the traffic loads of the interfering cells, and the probabilities of subcarrier collision if downlink segmentation is used. Finally, Atoll takes the ratio of the signal level and the sum of the total interference from other cells and the downlink noise (as calculated in "Traffic and Pilot Noise Calculation (DL)" on page 717). The receiver terminal is always considered to be oriented towards its best server, except when the "Lock Status" is set to "Server+Orientation" for a subscriber in a subscriber list and its azimuth and tilt manually edited. In the case of NLOS between the receiver and the best server, Atoll does not try to find the direction of the strongest signal, the receiver is oriented towards the best server just as in the case of LOS. Input •
TX ic i
C Traffic : Received traffic signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Traffic and Pilot Signal Level Calculation (DL)" on page 715.
•
TX ic i
C Pilot : Received pilot signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Traffic and Pilot Signal Level Calculation (DL)" on page 715.
•
TX ic i
n DL
: Downlink noise for the cell TXi(ic) as calculated in "Traffic and Pilot Noise Calculation (DL)" on page 717.
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TX jc j
•
I DL
: Effective downlink traffic and pilot interference from any cell TXj(jc) calculated for a pixel, subscriber, or mobile Mi covered by a cell TXi(ic) as explained in "Traffic and Pilot Interference Calculation (DL)" on page 718.
•
NRDL
•
T AMS : AMS threshold defined for the cell TXi(ic).
•
T B : Bearer selection thresholds of the bearers defined in the WiMAX equipment used by Mi’s terminal.
•
B DL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
Inter – Tech
: Inter-technology downlink noise rise.
TX ic i Mi M
i
or mobile Mi. •
Mi
B DL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber, or mobile Mi. TX i ic
•
N Ant – TX : Number of MIMO transmission (downlink) antennas defined for the cell TXi(ic).
•
N Ant – RX : Number of MIMO reception (downlink) antennas defined for the terminal used by the pixel, subscriber, or
Mi
mobile Mi. •
Mobility M i : Mobility used for the calculations.
•
Subchannel allocation mode used by the downlink permutation zone PZ DL assigned to the pixel, subscriber, or mobile
Mi
Mi as calculated in "Permutation Zone Selection" on page 714. •
M
i BLER BDL : Downlink block error rate read from the graphs available in the WiMAX equipment assigned to the
terminal used by the pixel, subscriber, or mobile Mi. •
Inter – Tech
I DL
: Downlink inter-technology interference as calculated in "Traffic and Pilot Interference Calculation (DL)"
on page 718. Calculations The traffic and pilot C/(I+N) for a cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi:
TX i ic
CINR Traffic
TX i ic
CINR Pilot
TXj jc TX i ic n IDL DL Inter – Tech Inter – Tech ------------------- --------------------- and + I DL + + NR DL = C Traffic – 10 Log 10 10 10 10 All TXj jc TX i ic
TX i ic
= C Pilot
TXj jc TX i ic n DL IDL Inter – Tech Inter – Tech ------------------- --------------------- + I DL + + NR DL 10 – 10 Log 10 10 10 All TXj jc
The Traffic Total Noise (I+N) for a cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX ic
TX i ic
I + N DL
i TX j jc n DL I DL --------------------- Inter – Tech 10 ----------------- + NR Inter – Tech = 10 Log + 10 10 + I DL DL 10 All TX j jc
Bearer Determination: The bearers available for selection in the pixel, subscriber, or mobile Mi’s WiMAX equipment are the ones:
728
•
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
•
Whose selection thresholds are less than the traffic or pilot C/(I+N) at Mi: T B CINR Traffic or T B CINR Pilot
Mi
TX i ic
Mi
TX i ic
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M
i
If the cell supports MIMO, the STTD/MRC or SU-MIMO diversity gain, G Div – DL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the WiMAX equipment assigned to the TX ic i
M
i
M
i
pixel, subscriber, or mobile Mi for N Ant – TX , N Ant – RX , the subchannel allocation mode of PZ DL , Mobility M i , M
i BLER B DL . DL
The additional diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the WiMAX equipment for which the following is true: Mi
Mi
DL
TX i ic
Mi
Mi
DL
TX i ic
T B – G Div – DL – G Div CINR Traffic T B – G Div – DL – G Div CINR Pilot
The bearer selected for data transfer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic). •
Bearer Index From among the bearers available for selection, the selected bearer is the one with the highest index.
•
Peak MAC Throughput From among the bearers available for selection, the selected bearer is the one with the highest downlink peak MAC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743.
•
Effective MAC Throughput From among the bearers available for selection, the selected bearer is the one with the highest downlink effective MAC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743.
MIMO – STTD/MRC and SU-MIMO Diversity Gain: Once the bearer is known, the traffic and pilot C/(I+N) calculated above become: TX i ic
TX i ic
Mi
DL
TX i ic
Mi
DL
CINR Traffic = CINR Traffic + G Div – DL + G Div TX i ic
CINR Pilot
M
= CINR Pilot + G Div – DL + G Div
i
Where G Div – DL is the STTD/MRC or SU-MIMO diversity gain corresponding to the selected bearer. Output TX i ic
•
CINR Traffic : Traffic C/(I+N) from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
CINR Pilot : Pilot C/(I+N) from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
•
I + N DL
TX i ic
TX i ic
: Traffic Total noise from the interfering cells TXj(jc) at the pixel, subscriber, or mobile Mi covered by a cell
TXi(ic). •
Mi
B DL : Bearer assigned to the pixel, subscriber, or mobile Mi in the downlink.
10.4.6.6 Traffic Signal Level Calculation (UL) Input M
i
•
P Max : Maximum transmission power of the terminal used by the pixel, subscriber, or mobile Mi without power control.
•
P Eff : Effective transmission power of the terminal used by the pixel, subscriber, or mobile Mi after power control as
Mi
calculated in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 737.
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i
•
E SA : Number of antenna elements defined for the smart antenna equipment used by the transmitter TXi.
•
G
TX
i
: Transmitter antenna gain for the antenna used by the transmitter TXi.
•
Without smart antennas: G
•
With smart antennas: G
TX i
TX
i
is the transmitter antenna gain, i.e., G
TX
i
TX
i
= G Ant .
is the uplink smart antenna beamforming gain, i.e., G
TX i
TX i
= G SA = 10 Log E SA .
For more information on the calculation of G SA , refer to section "Beamforming Smart Antenna Models" on page 43. TX i
: Total transmitter losses for the transmitter TXi ( L
TX i
= L Total – UL ).
•
L
•
L Path : Path loss ( L Path = L Model + L Ant ).
•
L Model : Loss on the transmitter-receiver path (path loss) calculated using a propagation model.
•
L Ant : Antenna attenuation (from antenna patterns) calculated for the antenna used by the transmitter TXi.
•
M Shadowing – Model : Shadowing margin based on the model standard deviation.
TX i
TX i
In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. •
L Indoor : Indoor losses taken into account when the option "Indoor coverage" is selected.
•
L
Mi
G
•
Mi
: Receiver terminal losses for the pixel, subscriber, or mobile Mi. : Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi.
Mi
L Ant : Receiver terminal’s antenna attenuation calculated for the pixel, subscriber, or mobile Mi.
•
M
i
For calculating the useful signal level from the best serving cell, L Ant is determined in the direction (H,V) = (0,0) from Mi
the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, L Ant is determined in the direction of the interfering cell from the antenna patterns of the antenna used by Mi, while the antenna is pointed towards Mi’s best serving cell. Mi
•
L Body : Body loss defined for the service used by the pixel, subscriber, or mobile Mi.
Calculations The received traffic signal level (dBm) from a pixel, subscriber, or mobile Mi at its serving cell TXi(ic) is calculated as follows: Mi
Mi
C UL = EIRP UL – L Path – M Shadowing – Model – L Indoor + G
TX i
–L
TX i
Mi
Mi
– L Ant – L Body
Where EIRP is the effective isotropic radiated power of the terminal calculated as follows: Mi
EIRP UL = P With P
Mi
Mi
+G
Mi
–L
Mi
Mi
= P Max without power control at the start of the calculations, and is the P
Mi
Mi
= P Eff after power control.
Output •
Mi
C UL : Received uplink signal level from the pixel, subscriber, or mobile Mi at a cell TXi(ic).
10.4.6.7 Traffic Noise Calculation (UL) For determining the uplink C/N and C/(I+N), Atoll calculates the uplink noise over the channel bandwidth used by the cell. The used bandwidth depends on the number of used subcarriers. The numbers of subcarriers used by different permutation zones can be different. The uplink noise comprises thermal noise and the noise figure of the equipment. The thermal noise density depends on the temperature, i.e., it remains constant for a given temperature. However, the value of the thermal noise varies with the used bandwidth.
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Input • •
K: Boltzmann’s constant. T: Temperature in Kelvin.
•
i UL N SCa – Used
M
PZ
: Number of subcarriers used by the uplink permutation zone of a cell TXi(ic) assigned to Mi.
TX i ic
•
N SCa – Total : Total number of subcarriers defined for the frame configuration of a cell TXi(ic).
•
F Sampling : Sampling frequency for the cell TXi(ic) as calculated in "Calculation of Sampling Frequency" on page 740.
•
nf
TX i ic
TX ic i
: Noise figure of the cell TXi(ic).
Calculations The power spectral density of thermal noise is calculated as follows: n 0 = 10 Log K T 1000 = – 174 dBm/Hz The thermal noise for a cell is calculated as: Mi
TX i ic
n 0 – UL
PZ UL N SCa – Used TXi ic = n 0 + 10 Log F Sampling ------------------------ TX i ic N SCa – Total
The uplink noise is the sum of the thermal noise and the noise figure of the cell TXi(ic). TX i ic
n UL
TX i ic
= n 0 – UL + nf
TX i ic
Output •
TX i ic
n UL
: Uplink noise for the cell TXi(ic).
10.4.6.8 Traffic Interference Calculation (UL) The uplink traffic interference is only calculated during Monte Carlo simulations. In coverage predictions, the uplink noise rise values already available in simulation results or in the Cells table are used. The interference received by a cell TXi(ic) from an interfering mobile covered by a cell TXj(jc) can be defined as the uplink signal level received from interfering mobiles Mj depending on the overlap that exists between the channels used by the cells TXi(ic) and TXj(jc), on the traffic loads of the interfering mobile Mj. The calculation of uplink interference can be divided into two parts: • •
10.4.6.8.1
Calculation of the uplink interference from each individual interfering mobile as explained in "Traffic Interference Signal Levels Calculation (UL)" on page 731. Calculation of the uplink noise rise which represents the total uplink interference from all the interfering mobiles as explained in "Noise Rise Calculation (UL)" on page 733.
Traffic Interference Signal Levels Calculation (UL) Input Mj
•
C UL : Uplink signal level received at a cell TXi(ic) from an interfering mobile Mj covered by a cell TXj(jc) as calculated in
•
"Traffic Signal Level Calculation (UL)" on page 729. M Shadowing – Model : Shadowing margin based on the model standard deviation.
•
M Shadowing – C I : Shadowing margin based on the C/I standard deviation. In Monte Carlo simulations, interfering signal levels already include M Shadowing – Model , as explained in "Traffic Signal Level Calculation (UL)" on page 729. In coverage predictions, the ratio M Shadowing – Model – M Shadowing – C I is applied to the interfering signals (for more information, see "Shadow Fading Model" on page 90). As the interfering signal levels already include
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M Shadowing – Model , M Shadowing – C I is added to the received interfering signal levels in order to achieve the ratio M Shadowing – Model – M Shadowing – C I : M
M
j
j
C UL = C UL + M Shadowing – C I In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. •
TX i ic – TX j jc
rO
: Total channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Co- and Adjacent
Channel Overlaps Calculation" on page 702. •
Mj
TL UL : Uplink traffic load of the interfering mobile Mj. Traffic loads are calculated during Monte Carlo simulations as explained in "Scheduling and Radio Resource Allocation" on page 748.
Calculations The uplink interference received at a cell TXi(ic) from an interfering mobile Mj covered by a cell TXj(jc) is calculated as follows: Mj
Mj
TX i ic – TX j jc
I UL = C UL + f O
TX i ic – TX j jc
Mj
+ f TL – UL + f Seg – UL
Calculations for the interference reduction factors due to channel overlapping, uplink traffic load, and uplink segmentation are explained below: Interference reduction due to the co- and adjacent channel overlap between the studied and the interfering cells: Interference reduction due to the co- and adjacent channel overlap between the cells TXi(ic) and TXj(jc) is calculated as follows: TX i ic – TX j jc
fO
TX i ic – TX j jc
= 10 Log r O
Interference reduction due to interfering mobile’s traffic load: The interference reduction factor due to the interfering mobile’s uplink traffic load is calculated as follows: M
M
j j f TL – UL = 10 Log TL UL
Interference reduction due to uplink segmentation: If you select uplink segmentation support for the frame configuration that you are using, it means that the first zone in the uplink, i.e., the UL PUSC zone, is segmented. All other zones are pooled together to form a group of nonsegmented zones. The interference reduction factor due to uplink segmentation is calculated as follows: TX ic – TX jc i j
f Seg – UL
TX ic – TX jc
i j = 10 Log p Collision – UL
TX i ic – TX j jc
Where p Collision – UL
is the collision probability between the subcarriers of the uplink segments being used by the
interfered and interfering cells. It is determined during Monte Carlo simulations as follows: TX i ic – TX j jc
p Collision – UL
SC Com = -----------------TX i ic SC
Where, SCCom is the number of subchannels common in TXi(ic) and TXj(jc), SC the cell TXi(ic).
TX i ic
is the number of subchannels in
The segment numbers and the cell permutation base numbers (Cell PermBase) are determined from the cell’s preamble index. The mapping between the preamble index, the segment number, and Cell PermBase is available in the IEEE specifications. This mapping is performed in Atoll as follows: Preamble Index ( PI ) Range: 0 to 113 Cell PermBase ( PB ) Range: 0 to 31
732
PI 96
96 PI 114
PI Modulo 32
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Segment Number ( N Seg ) Range: 0, 1, 2
PI Floor ------ 32
PI – 96 Modulo 3
In Monte Carlo simulations, Atoll calculates two separate noise rise values; for the mobiles served by the segmented zone of the interfered cell Atoll calculates the uplink segmented noise rise, and for the mobiles served by the nonsegmented zones of the interfered cell Atoll calculates the uplink noise rise. In coverage predictions, point analysis, and calculations on subscriber lists, according to the zone, segmented or nonsegmented, that covers the pixel, receiver, or subscriber, Atoll uses either the uplink segmented noise rise or the uplink noise rise to calculate the C/(I+N). For more information on the calculation of the uplink noise rise, see "Noise Rise Calculation (UL)" on page 733. Output •
10.4.6.8.2
Mj
I UL : Uplink interference signal level received at a cell TXi(ic) from an interfering mobile Mj covered by a cell TXj(jc).
Noise Rise Calculation (UL) The uplink noise rise is defined as the ratio of the total uplink interference received by any cell TXi(ic) from interfering mobiles Mj present in the coverage areas of other cells TXj(jc) to the uplink noise of the cell TXi(ic). In other words, it is the ratio (I+N)/N. Input •
Mj
I UL : Uplink interference signal levels received at a cell TXi(ic) from interfering mobiles Mj covered by other cells TXj(jc) as calculated in "Traffic Interference Signal Levels Calculation (UL)" on page 731. TX i ic
•
n UL
•
NR UL
: Uplink noise for the cell TXi(ic) as calculated in "Traffic Noise Calculation (UL)" on page 730.
Inter – Tech
: Inter-technology uplink noise rise.
Calculations The uplink noise rise and total noise (I+N) for the cell TXi(ic) are calculated as follows: •
Without smart antennas: For any mobile Mi covered by a non-segmented zone in the interfered cell TXi(ic), Atoll calculates the UL noise rise as follows:
TX i ic
NR UL
TX i ic IMj n UL UL - non-seg M i -------------------TX i ic Inter – Tech 10 -------------------------------------------= 10 Log + NRUL – n UL 10 10 + 10 All Mj All TX jc j
For any pixel, subscriber, or mobile Mi covered by the non-segmented zone in the interfered cell TXi(ic), Atoll calculates the uplink total noise (I+N) as follows: TX i ic
I + N UL
TX i ic
= NR UL
TX i ic
+ n UL
For any mobile Mi covered by the segmented zone in the interfered cell TXi(ic), Atoll calculates the segmented zone UL noise rise as follows:
TX i ic
NR UL – Seg
TX i ic IMj n UL UL seg M i --------------------- TX i ic 10 Inter – Tech --------------------------------= 10 Log + NR UL – n UL 10 10 + 10 All M j All TX jc j
For any pixel, subscriber, or mobile Mi covered by the segmented zone in the interfered cell TXi(ic), Atoll calculates the uplink total noise (I+N) as follows: TX i ic
I + N UL
TX i ic
TX i ic
= NR UL – Seg + n UL
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With smart antennas: The angular distribution of the uplink noise rise is calculated during Monte Carlo simulations and can be stored in the Cells table in order to be used in coverage predictions. The angular distribution of the uplink noise rise is given by: 2
I UL + n I NRUL = --------------------------------2 n I TX i ic
I + N UL
2
= I UL + n I
Output TX i ic
•
NRUL
: Non-segmented uplink noise rise for the cell TXi(ic).
•
NRUL – Seg : Segmented uplink noise rise for the cell TXi(ic).
•
NRUL
•
I + N UL
TX i ic TX i ic
: Angular distribution of the uplink noise rise for the cell TXi(ic).
TX i ic
TX i ic
or I + N UL
: Total Noise for a cell TXi(ic) calculated for any pixel, subscriber, or mobile Mi.
10.4.6.9 Traffic C/N Calculation (UL) Input •
M
i
C UL : Received uplink signal level from the pixel, subscriber, or mobile Mi at its serving cell TXi(ic) as calculated in "Traffic Signal Level Calculation (UL)" on page 729. TX i ic
•
n UL
•
T AMS : AMS threshold defined for the cell TXi(ic).
•
T B – Lowest : Bearer selection threshold of the lowest bearer in the WiMAX equipment assigned to the cell TXi(ic).
•
: Uplink noise for the cell TXi(ic) as calculated in "Traffic Noise Calculation (UL)" on page 730.
TX i ic TX ic i Mi PZ UL
N SC
: Number of subchannels per channel defined for the uplink permutation zone assigned to the pixel, subscriber,
or mobile Mi as calculated in "Permutation Zone Selection" on page 714. Mi PZ UL = 8
•
N SC Seg : Number of subchannels per segment for the first uplink PUSC permutation zone.
•
P Max : Maximum transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
P Min : Minimum transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
M PC : Power control margin defined in the global network settings.
•
T B : Bearer selection thresholds of the bearers defined in the WiMAX equipment used bythe cell TXi(ic).
•
B UL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
Mi Mi
M
i
Mi
or mobile Mi. •
M
i
B UL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber, or mobile Mi.
•
Mi
N Ant – TX : Number of MIMO transmission (uplink) antennas defined for the terminal used by the pixel, subscriber, or mobile Mi. TX i ic
•
N Ant – RX : Number of MIMO reception (uplink) antennas defined for the cell TXi(ic).
•
Mobility M i : Mobility used for the calculations.
•
Subchannel allocation mode used by the uplink permutation zone PZ UL assigned to the pixel, subscriber, or mobile
M
Mi as calculated in "Permutation Zone Selection" on page 714.
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M
i BLER B UL : Uplink block error rate read from the graphs available in the WiMAX equipment assigned to the cell
•
TXi(ic). Calculations The uplink C/N from a pixel, subscriber, or mobile Mi at its serving cell TXi(ic) is calculated as follows: M
M
i
i
TX ic i
CNR UL = C UL – n UL
Bearer Determination: The bearers available for selection in the cell TXi(ic)’s WiMAX equipment are the ones: •
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
•
Whose selection thresholds are less than the uplink C/N at Mi: T B CNR UL
Mi
Mi
TX i ic
If the cell supports MIMO, the STTD/MRC, SU-MIMO diversity or MU-MIMO diversity gain, G Div – UL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the Mi
TX i ic
Mi
WiMAX equipment assigned to the cell TXi(ic) for N Ant – RX , N Ant – TX , the subchannel allocation mode of PZ UL , M
i Mobility M i , BLER B UL . UL
The additional diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the WiMAX equipment for which the following is true: Mi
TX i ic
UL
Mi
T B – G Div – UL – G Div CNR UL The bearer selected for data transfer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic). •
Bearer Index From among the bearers available for selection, the selected bearer is the one with the highest index.
•
Peak MAC Throughput From among the bearers available for selection, the selected bearer is the one with the highest uplink peak MAC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743.
•
Effective MAC Throughput From among the bearers available for selection, the selected bearer is the one with the highest uplink effective MAC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743.
MIMO – STTD/MRC, SU-MIMO Diversity, and MU-MIMO Diversity Gain: Once the bearer is known, the uplink C/N calculated above becomes: Mi
Mi
TX i ic
UL
CNR UL = CNR UL + G Div – UL + G Div TX i ic
Where G Div – UL is the STTD/MRC, SU-MIMO diversity, or MU-MIMO diversity gain corresponding to the selected bearer. Uplink Subchannelisation: The uplink subchannelisation depends on the uplink bandwidth allocation target defined for the scheduler used by the cell TXi(ic). The uplink C/N calculated above is given for the total number of subchannels associated with the
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permutation zone, i.e., N SC
i UL
. Subchannelisation is performed for all the pixels, subscribers, or mobiles in the uplink,
and may reduce the number of used subchannels in order to satisfy the selected target. •
Full Bandwidth Full channel width is used by each mobile in the uplink. As there is no reduction in the bandwidth used for transmission, there is no gain in the uplink C/N.
•
Maintain Connection The bandwidth used for transmission by a mobile is reduced only if the uplink C/N is not enough to even access the lowest bearer. For example, as a mobile moves from good to bad radio conditions, the number of subchannels used by it for transmission in uplink are reduced one by one in order to improve the uplink C/N. The calculation of the gain introduced by the subchannelisation is explained below.
•
Best Bearer The bandwidth used for transmission by a mobile is reduced in order to improve the uplink C/N enough to access the best bearer. For example, if using 5 subchannels, a mobile is able to access the best bearer, and using 6 it would only get access to the second best, it will be assigned 5 subchannels as the used uplink bandwidth. Although using 4 subchannels, its uplink C/N will be better than when using 5, the uplink bandwidth is not reduced to 4 because it does not provide any gain in terms of the bearer, i.e., the mobile already has the best bearer using 5 subchannels. The calculation of the gain introduced by the bandwidth reduction is explained below. The definition of the best bearer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic), i.e., bearer with the highest index, with the highest peak MAC throughput, or with the highest effective MAC throughput.
The uplink subchannelisation may result in the use of a number of subchannels which is less than the total number of subchannels associated with the permutation zone. The gain related to this bandwidth reduction is applied to the uplink C/N: Mi
Mi
CNR UL Final
Where
PZUL Mi N SC = CNR UL+ 10 Log ---------------- N Mi All SC SC – UL
Min N SC – UL Service
M
i N SC – UL
PZ
N SC
Mi UL
for any pixel, subscriber, or mobile Mi covered by a non-segmented
permutation zone in the interfered cell TXi(ic), and
Min N SC – UL Service
Mi
Mi PZ UL = 8
N SC – UL N SC Seg for any pixel, subscriber,
or mobile Mi covered by the segmented uplink PUSC zone in the interfered cell TXi(ic). Uplink Power Control: Once the subchannelisation is performed, Atoll continues to work with the C/N given by the subchannelisation, i.e., M
M
i
i
CNR UL = CNR UL . Final
The pixel, subscriber, or mobile Mi reduces its transmission power so that the uplink C/N from it at its cell is just enough to get the selected bearer. If with P
Mi
Mi
Mi
= P Max AND CNR UL T
TX i ic Mi
+ M PC , where T
B UL
TX i ic Mi B UL
is the bearer selection threshold, from the WiMAX
equipment assigned to the cell TXi(ic), for the bearer selected for the pixel, subscriber, or mobile Mi. The transmission power of Mi is reduced to determine the effective transmission power from the pixel, subscriber, or mobile Mi as follows: Mi M i TX i ic Mi Mi P Eff = Max PMax – CNR UL – T M + M PC P Min B i UL
Mi
Mi
CNR UL is calculated again using P Eff .
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Output •
M
i
CNR UL : Uplink C/N from a pixel, subscriber, or mobile Mi at it serving cell TXi(ic).
10.4.6.10 Traffic C/(I+N) and Bearer Calculation (UL) The carrier signal to interference and noise ratio is calculated in three steps. First, Atoll calculates the received signal level from each pixel, subscriber, or mobile at its serving cell using the effective power of the terminal used by the pixel, subscriber, or mobile as explained in "Traffic Signal Level Calculation (UL)" on page 729. Next, Atoll calculates the uplink carrier to noise ratio as explained in "Traffic C/N Calculation (UL)" on page 734. Finally, determines the uplink C/(I+N) by dividing the previously calculated uplink C/N by the uplink noise rise value of the cell as calculated in "Noise Rise Calculation (UL)" on page 733. The uplink noise rise can be set by the user manually for each cell or calculated using Monte Carlo simulations. The receiver terminal is always considered to be oriented towards its best server, except when the "Lock Status" is set to "Server+Orientation" for a subscriber in a subscriber list and its azimuth and tilt manually edited. In the case of NLOS between the receiver and the best server, Atoll does not try to find the direction of the strongest signal, the receiver is oriented towards the best server just as in the case of LOS. Input Mi
•
CNR UL : Uplink C/N from a pixel, subscriber, or mobile Mi at it serving cell TXi(ic) as calculated in "Traffic C/N Calculation (UL)" on page 734.
•
NR UL
TX i ic
: Non-segmented uplink noise rise for the cell TXi(ic) as calculated in "Noise Rise Calculation (UL)" on
page 733. TX i ic
•
NR UL – Seg : Segmented uplink noise rise for the cell TXi(ic) as calculated in "Noise Rise Calculation (UL)" on page 733.
•
NR UL
TX i ic
: Angular distribution of the uplink noise rise for the cell TXi(ic) as calculated in "Noise Rise Calculation
(UL)" on page 733. TX ic i
•
T AMS : AMS threshold defined for the cell TXi(ic).
•
T B – Lowest : Bearer selection threshold of the lowest bearer in the WiMAX equipment assigned to the cell TXi(ic).
•
N SC
TX i ic Mi PZ UL
: Number of subchannels per channel defined for the uplink permutation zone assigned to the pixel, subscriber,
or mobile Mi as calculated in "Permutation Zone Selection" on page 714. M i PZ UL = 8
•
N SC Seg : Number of subchannels per segment for the first uplink PUSC permutation zone.
•
P Max : Maximum transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
P Min : Minimum transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
M PC : Power control margin defined in the global network settings.
•
T B : Bearer selection thresholds of the bearers defined in the WiMAX equipment used bythe cell TXi(ic).
•
B UL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
Mi Mi
Mi
Mi
or mobile Mi. •
Mi
B UL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber, or mobile Mi.
•
M
i
N Ant – TX : Number of MIMO transmission (uplink) antennas defined for the terminal used by the pixel, subscriber, or mobile Mi. TX i ic
•
N Ant – RX : Number of MIMO reception (uplink) antennas defined for the cell TXi(ic).
•
Mobility M i : Mobility used for the calculations.
•
Subchannel allocation mode used by the uplink permutation zone PZ UL assigned to the pixel, subscriber, or mobile
Mi
Mi as calculated in "Permutation Zone Selection" on page 714.
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M
i BLER BUL : Uplink block error rate read from the graphs available in the WiMAX equipment assigned to the cell
TXi(ic). Calculations The uplink C/(I+N) for any pixel, subscriber, or mobile Mi at a cell TXi(ic) is calculated as follows: •
Without smart antennas: For any pixel, subscriber, or mobile Mi covered by the non-segmented zone in the interfered cell TXi(ic): Mi
Mi
TX i ic
CINR UL = CNR UL – NRUL
For any pixel, subscriber, or mobile Mi covered by the segmented zone in the interfered cell TXi(ic): Mi
Mi
TX i ic
CINR UL = CNR UL – NRUL – Seg •
With smart antennas: •
Monte Carlo simulations: The uplink C/(I+N) is calculated as described in the section "Beamforming Smart Antenna Models" on page 43. Victim and interfering mobiles are generated by a time-slot scenario as explained in "Simulation Process" on page 699.
•
Coverage predictions: CINR UL = CNR UL – NR UL
M
i
M
i
TX ic i
Bearer Determination: The bearers available for selection in the cell TXi(ic)’s WiMAX equipment are the ones: •
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
•
Whose selection thresholds are less than the uplink C/(I+N) at Mi: T B CINR UL and T B CINR UL
Mi
Mi
Mi
Mi
TX ic i
If the cell supports MIMO, the STTD/MRC, SU-MIMO diversity or MU-MIMO diversity gain, G Div – UL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the M
i
TX ic i
M
i
WiMAX equipment assigned to the cell TXi(ic) for N Ant – RX , N Ant – TX , the subchannel allocation mode of PZ UL , M
i Mobility M i , BLER B UL . UL
The additional diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the WiMAX equipment for which the following is true: Mi
TX i ic
UL
Mi
Mi
TX i ic
UL
Mi
T B – G Div – UL – G Div CINR UL and T B – G Div – UL – G Div CINR UL The bearer selected for data transfer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic). •
Bearer Index From among the bearers available for selection, the selected bearer is the one with the highest index.
•
Peak MAC Throughput From among the bearers available for selection, the selected bearer is the one with the highest uplink peak MAC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743.
•
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From among the bearers available for selection, the selected bearer is the one with the highest uplink effective MAC channel throughput as calculated in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743. MIMO – STTD/MRC, SU-MIMO Diversity, and MU-MIMO Diversity Gain: Once the bearer is known, the uplink C/(I+N) calculated above becomes: Mi
Mi
TX i ic
UL
CNR UL = CNR UL + G Div – UL + G Div Mi
TX i ic
Mi
UL
CINR UL = CINR UL + G Div – UL + G Div and Mi
TX i ic
Mi
UL
CINR UL = CINR UL + G Div – UL + G Div TX i ic
Where G Div – UL is the STTD/MRC, SU-MIMO diversity, or MU-MIMO diversity gain corresponding to the selected bearer. Uplink Subchannelisation: The uplink subchannelisation depends on the uplink bandwidth allocation target defined for the scheduler used by the cell TXi(ic). The uplink C/(I+N) calculated above is given for the total number of subchannels associated with the Mi PZ UL
permutation zone, i.e., N SC
. Subchannelisation is performed for all the pixels, subscribers, or mobiles in the uplink,
and may reduce the number of used subchannels in order to satisfy the selected target. •
Full Bandwidth Full channel width is used by each mobile in the uplink. As there is no reduction in the bandwidth used for transmission, there is no gain in the uplink C/(I+N).
•
Maintain Connection The bandwidth used for transmission by a mobile is reduced only if the uplink C/(I+N) is not enough to even access the lowest bearer. For example, as a mobile moves from good to bad radio conditions, the number of subchannels used by it for transmission in uplink are reduced one by one in order to improve the uplink C/(I+N). The calculation of the gain introduced by the subchannelisation is explained below.
•
Best Bearer The bandwidth used for transmission by a mobile is reduced in order to improve the uplink C/(I+N) enough to access the best bearer. For example, if using 5 subchannels, a mobile is able to access the best bearer, and using 6 it would only get access to the second best, it will be assigned 5 subchannels as the used uplink bandwidth. Although using 4 subchannels, its uplink C/(I+N) will be better than when using 5, the uplink bandwidth is not reduced to 4 because it does not provide any gain in terms of the bearer, i.e., the mobile already has the best bearer using 5 subchannels. The calculation of the gain introduced by the bandwidth reduction is explained below. The definition of the best bearer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic), i.e., bearer with the highest index, with the highest peak MAC throughput, or with the highest effective MAC throughput.
The uplink subchannelisation may result in the use of a number of subchannels which is less than the total number of subchannels associated with the permutation zone. The gain related to this bandwidth reduction is applied to the uplink C/(I+N): Mi
Mi
CINR UL Final
Where
PZUL N SC = CINR UL+ 10 Log ---------------- NMi All SC SC – UL Mi
Min N SC – UL Service
M
i N SC – UL
PZ
N SC
Mi UL
for any pixel, subscriber, or mobile Mi covered by a non-segmented
permutation zone in the interfered cell TXi(ic), and
Min N SC – UL Service
Mi
Mi PZ UL = 8
N SC – UL N SC Seg for any pixel, subscriber,
or mobile Mi covered by the segmented uplink PUSC zone in the interfered cell TXi(ic). Uplink Power Control:
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Once the subchannelisation is performed, Atoll continues to work with the C/(I+N) given by the subchannelisation, M
M
i
i
i.e., CINR UL = CINR UL . Final
The pixel, subscriber, or mobile Mi reduces its transmission power so that the uplink C/(I+N) from it at its cell is just enough to get the selected bearer. If with P
Mi
Mi
Mi
= P Max AND CINR UL T
TX i ic Mi
+ M PC , where T
B UL
TX i ic Mi B UL
is the bearer selection threshold, from the WiMAX
equipment assigned to the cell TXi(ic), for the bearer selected for the pixel, subscriber, or mobile Mi. The transmission power of Mi is reduced to determine the effective transmission power from the pixel, subscriber, or mobile Mi as follows: Mi M i TX i ic Mi Mi P Eff = Max PMax – CINR UL – T M + M PC P Min i B UL
Mi
Mi
CINR UL is calculated again using P Eff . Output Mi
Mi
•
CINR UL or CINR UL : Uplink C/(I+N) from a pixel, subscriber, or mobile Mi at it serving cell TXi(ic).
•
N SC – UL : Number of subchannels used by the pixel, subscriber, or mobile Mi in the uplink after subchannelisation.
•
P Eff : Effective transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
B UL : Bearer assigned to the pixel, subscriber, or mobile Mi in the uplink.
Mi
Mi M
i
10.4.7 Throughput Calculation Throughputs are calculated in two steps. • •
Calculation of uplink and downlink total resources in a cell as explained in "Calculation of Total Cell Resources" on page 740. Calculation of throughputs as explained in "Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation" on page 743.
10.4.7.1 Calculation of Total Cell Resources The total amount of resources in a cell is the number of modulation symbols that can be used for data transfer in each frame. The total cell resources can be calculated separately for the downlink and the uplink subframes. The following sections describe how the cell capacities are calculated for TDD and FDD networks.
10.4.7.1.1
Calculation of Sampling Frequency Input TX ic i
•
f Sampling : Sampling factor defined for the frequency band of the cell TXi(ic).
•
W Channel : Channel bandwidth of the cell TXi(ic).
TX i ic
Calculations Atoll determines the sampling frequency as follows: TX i ic
TX ic i
F Sampling
6
W Channel 10 - 8000 = Floor f Sampling ----------------------------------8000
Output •
740
TX i ic
F Sampling : Sampling frequency for the cell TXi(ic).
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10.4.7.1.2
Calculation of Symbol Duration Input TX ic i
•
F Sampling : Sampling frequency for the cell TXi(ic) as calculated in "Calculation of Sampling Frequency" on page 740.
•
N SCa – Total : Total number of subcarriers defined for the frame configuration of a cell TXi(ic).
•
r CP
TX i ic
TX i ic
: Cyclic prefix ratio defined for the frame configuration of TXi(ic) or, otherwise, in the global network settings.
Calculations From the sampling frequency, Atoll determines the inter-subcarrier spacing. F
TX ic i
TX i ic
–3
F Sampling 10 = ------------------------------------TX i ic N SCa – Total
Atoll calculates the useful symbol duration. TX i ic 1 D Sym – Useful = ------------------TX ic i F
And, the duration of the cyclic prefix. TX i ic
D CP
TX i ic
r CP = -------------F
Adding the Cyclic prefix ratio to the useful symbol duration, Atoll determines the total symbol duration. TX i ic
TX i ic
TX i ic
D Symbol = D Sym – Useful + D CP Output •
10.4.7.1.3
TX i ic
D Symbol : Total symbol duration of one modulation symbol for a cell TXi(ic).
Calculation of Total Cell Resources - TDD Networks Input •
D Frame : Frame duration.
•
D TTG : TTG duration.
•
D RTG : RTG duration.
•
D Symbol : Total symbol duration of one modulation symbol for a cell TXi(ic) as calculated in "Calculation of Symbol Duration" on page 741.
•
r DL – Frame : DL ratio.
•
N SD – DL : Number of symbol durations that correspond to the downlink subframe.
•
N SD – UL : Number of symbol durations that correspond to the uplink subframe.
•
O Fixed : Downlink fixed overhead.
•
O Variable : Downlink variable overhead.
•
O Fixed : Uplink fixed overhead.
•
O Variable : Uplink variable overhead.
• •
TDD TDD
TX i ic
TDD
TDD TDD DL DL
UL UL
Mi PZ DL
N SCa – Data : Number of data subcarriers of the downlink permutation zone of a cell TXi(ic) assigned to Mi. Mi PZ UL
N SCa – Data : Number of data subcarriers of the uplink permutation zone of a cell TXi(ic) assigned to Mi.
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Calculations The downlink and the uplink subframes of a TDD frame are separated in time by the TTG and the RTG time guards. First of all, Atoll calculates the useful frame duration by removing the TTG and RTG from the frame duration: Used
TDD
TDD
D Frame = D Frame – D TTG – D RTG
Then, Atoll calculates the frame duration in terms of number of symbol durations: D Used TX ic i Frame N SD – Used Frame = Floor ----------------TX i ic D Symbol Next, Atoll calculates the downlink and uplink cell capacities as follows: Downlink Subframe: Atoll calculates the number of symbol durations in the downlink subframe excluding the fixed overhead defined in the global network settings: TX ic
TX ic
i i TDD DL N SD – DL Subframe = RoundUp N SD – Used Frame r DL – Frame – O Fixed if DL:UL ratio is defined in percentage. TDD
TX i ic N SD – DL TXi ic DL Or N SD – DL Subframe = RoundUp N SD – Used Frame ----------------------------------------- – O Fixed if DL:UL ratio is defined in TDD TDD N SD – DL + N SD – UL
fraction. The RoundUp function rounds a float value up to the nearest integer value. The total number of symbols in the downlink subframe after removing the variable overhead is: TX i ic
R DL
TX i ic
= N Sym – DL Subframe
Mi DL PZ DL O Variable TXi ic = Floor N SD – DL Subframe N SCa – Data 1 – -------------------- 100
Uplink Subframe: Atoll calculates the number of symbol durations in the uplink subframe excluding the fixed overhead defined in the global network settings: TX ic
TX ic
i i TDD UL N SD – UL Subframe = RoundDown N SD – Used Frame 1 – r DL – Frame – O Fixed percentage.
if DL:UL ratio is defined in
TDD
TX i ic TX i ic N SD – UL UL Or N SD – UL Subframe = RoundDown N SD – Used Frame ----------------------------------------- – O Fixed if DL:UL ratio is defined in TDD TDD N SD – DL + N SD – UL
fraction. The RoundDown function rounds a float value down to the nearest integer value. The total number of symbols in the uplink subframe after removing the variable overhead is: TX ic i R UL
=
TX ic i N Sym – UL Subframe
Mi UL PZ O Variable TX i ic UL = Floor N SD – UL Subframe N SCa – Data 1 – --------------------- 100
Output
10.4.7.1.4
TX i ic
•
R DL
•
R UL
TX i ic
TX i ic
= N Sym – DL Subframe : Amount of downlink resources in the cell TXi(ic). TX i ic
= N Sym – UL Subframe : Amount of uplink resources in the cell TXi(ic).
Calculation of Total Cell Resources - FDD Networks The total cell resources calculation is the same for downlink and uplink subframes in FDD networks. Therefore, the symbol X is used to represent DL or UL in the expressions below.
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Input •
D Frame : Frame duration.
•
D Symbol : Total symbol duration of one modulation symbol for a cell TXi(ic) as calculated in "Calculation of Symbol Duration" on page 741.
•
O Fixed : Downlink or uplink fixed overhead.
•
O Variable : Downlink or uplink variable overhead.
•
TX ic i
X X
Mi PZ X
N SCa – Data : Number of data subcarriers of the downlink or uplink permutation zone of a cell TXi(ic) assigned to Mi.
Calculations There are no transmit and receive time guards in FDD systems. Therefore, the downlink and the uplink subframe durations are the same as the frame duration. X
D Subframe = D Frame The subframe durations in terms of the number of symbol durations excluding the fixed overheads are: DX TX ic i Subframe - – O XFixed N SD – X Subframe = Floor ---------------------TX i ic D Symbol The total numbers of symbols in the downlink or uplink subframes after removing the variable overheads are: TX i ic
RX
TX i ic
= N Sym – X Subframe
Mi X PZ X O Variable TXi ic = Floor N SD – X Subframe N SCa – Data 1 – -------------------- 100
Output •
TX i ic
TX i ic
= N Sym – X Subframe : Amount of downlink or uplink resources in the cell TXi(ic).
RX
10.4.7.2 Channel Throughput, Cell Capacity, Allocated Bandwidth Throughput, and Per-User Throughput Calculation Channel throughputs are calculated for the entire channel resources allocated to the pixel, subscriber, or mobile Mi. Cell capacities are similar to channel throughputs but upper-bound by the maximum downlink and uplink traffic loads. Allocated bandwidth throughputs are calculated for the number of used subchannels in uplink allocated to the pixel, subscriber, or mobile Mi. Per-user throughputs are calculated by dividing the downlink cell capacities or uplink allocated bandwidth throughputs by the average number of downlink or uplink users defined for the cell, respectively. Input TX i ic
•
TL DL – Max : Maximum downlink traffic load for the cell TXi(ic).
•
TL UL – Max : Maximum uplink traffic load for the cell TXi(ic).
•
R DL
TX i ic
TX i ic
: Amount of downlink resources in the cell TXi(ic) as calculated in "Calculation of Total Cell Resources" on
page 740. TX i ic
•
R UL
•
page 740. M : Bearer efficiency (bits/symbol) of the bearer assigned to the pixel, subscriber, or mobile Mi in the downlink in
: Amount of uplink resources in the cell TXi(ic) as calculated in "Calculation of Total Cell Resources" on
•
"Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 727. M : Bearer efficiency (bits/symbol) of the bearer assigned to the pixel, subscriber, or mobile Mi in the uplink in
i B DL
i B UL
"Traffic C/(I+N) and Bearer Calculation (UL)" on page 737.
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D Frame : Frame duration. f Segment – DL : Downlink segmenting factor for the first downlink PUSC zone as calculated in "Effective Traffic and Pilot Interference Calculation (DL)" on page 722. TX ic i
•
CNR Preamble : Preamble C/N the cell TXi(ic) as calculated in "Preamble C/N Calculation" on page 712.
•
T AMS : AMS threshold defined for the cell TXi(ic).
•
T MU – MIMO : MU-MIMO threshold defined for the cell TXi(ic).
•
G MU – MIMO : MU-MIMO gain defined for the cell TXi(ic).
•
•
•
TX ic i TX i ic
TX i ic
TX ic
M
i i BLER BDL : Downlink block error rate read from the BLER vs. CINR Traffic graph available in the WiMAX equipment assigned to the terminal used by the pixel, subscriber, or mobile Mi. M
M
i i BLER BUL : Uplink block error rate read from the BLER vs. CINR UL graph available in the WiMAX equipment assigned to the cell TXi(ic). Mi
f TP – Scaling : Throughput scaling factor defined in the properties of the service used by the pixel, subscriber, or mobile Mi.
• •
M
i
TP Offset : Throughput offset defined in the properties of the service used by the pixel, subscriber, or mobile Mi. Mi PZ UL
N SC
: Number of subchannels per channel defined for the uplink permutation zone assigned to the pixel, subscriber,
or mobile Mi as calculated in "Permutation Zone Selection" on page 714. •
Mi
N SC – UL : Number of uplink subchannels after subchannelisation with which the pixel, subscriber, or mobile Mi can get the highest available bearer, as calculated in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 737. TX i ic
•
N Users – DL : Number of users connected to the cell TXi(ic) in downlink.
•
N Users – UL : Number of users connected to the cell TXi(ic) in uplink.
TX i ic
Calculations Downlink: TX i ic
•
Mi
R DL
M i B DL
Peak MAC Channel Throughput: CTP P – DL = --------------------------------D Frame In the above formula, the actual value of D Frame is used to calculate the channel throughput for coverage predictions, while D Frame = 1 sec for Monte Carlo simulations. TX ic i
For proportional fair schedulers, the channel throughput is increased by the multi-user diversity gain G MUG – DL read from the scheduler properties for the Mobility M i and the number of users connected to the cell in downlink. TX i ic
R DL Mi
M B
i
TX ic
CTP P – DL
i DL = -------------------------------- G MUG – DL D Frame
TX ic i
M
i
Max
G MUG – DL = 1 if CINR Traffic CINR MUG If the multi-user diversity gain for the exact value of the number of connected users is not available in the graph, it is interpolated from the gain values available for the numbers of users just less than and just greater than the actual number of users. Downlink Segmentation: M
i
If the permutation zone assigned to the pixel, subscriber, or mobile Mi is the first downlink PUSC zone ( PZ DL = 0 ) and it is segmented, the channel throughput is calculated as:
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M
i
i
CTP P – DL = CTP P – DL f Segment – DL MIMO – SU-MIMO Gain: If the permutation zone assigned to the pixel, subscriber, or mobile Mi supports SU-MIMO or AMS, SU-MIMO gain Max
G SU – MIMO is applied to the bearer efficiency. The gain is read from the properties of the WiMAX equipment assigned to the pixel, subscriber, or mobile Mi for: TX ic i
•
N Ant – TX : Number of MIMO transmission (downlink) antennas defined for the cell TXi(ic).
•
N Ant – RX : Number of MIMO reception (downlink) antennas defined for the terminal used by the pixel, subscriber,
Mi
or mobile Mi. •
Mobility M i : Mobility used for the calculations.
•
Subchannel allocation mode used by the downlink permutation zone PZ DL assigned to the pixel, subscriber, or
Mi
mobile Mi as calculated in "Permutation Zone Selection" on page 714. •
M
i
B DL : Bearer assigned to the pixel, subscriber, or mobile Mi in the downlink as explained in "Traffic and Pilot C/ (I+N) and Bearer Calculation (DL)" on page 727.
•
M
i BLER B DL : Downlink block error rate read from the graphs available in the WiMAX equipment assigned to the TX ic i
terminal used by the pixel, subscriber, or mobile Mi. BLER is determined for CINR Traffic . Atoll also takes into account the SU-MIMO Gain Factor f SU – MIMO defined for the clutter class where the pixel, subscriber, or mobile Mi is located. In case of SU-MIMO:
In case of AMS:
Mi
Mi B DL
=
B DL
=
Max
Mi B DL
1 + f SU – MIMO G SU – MIMO – 1 TX i ic
Max
Mi
TX i ic
1 + f SU – MIMO G SU – MIMO – 1 if CNR Preamble T AMS
TX i ic
TX i ic
or CINR Preamble T AMS
B DL
If the Max SU-MIMO Gain for the exact value of the C/(I+N) is not available in the table, it is interpolated from the gain values available for the C/(I+N) just less than and just greater than the actual C/(I+N). •
M
M
M
i i i Effective MAC Channel Throughput: CTP E – DL = CTP P – DL 1 – BLER B DL M
i CTP A – DL
=
M
Mi
i CTP E – DL
M f TP – Scaling i - – TP Offset -----------------------100
•
Application Channel Throughput:
•
Peak MAC Cell Capacity: Cap P – DL = CTP P – DL TL DL – Max
•
i i i Effective MAC Cell Capacity: Cap E – DL = Cap P – DL 1 – BLER B DL
•
•
Mi
TX i ic
Mi
M
Application Cell Capacity:
M
i Cap A – DL
M
=
Mi
M
i Cap E – DL Mi
Peak MAC Throughput per User: PUTP P – DL
M
M f TP – Scaling i - – TP Offset -----------------------100 Mi
Cap P – DL = ----------------------TX i ic N Users – DL Mi
•
•
Mi Cap E – DL Effective MAC Throughput per User: PUTP E – DL = ----------------------TX i ic N Users – DL Mi
Application Throughput per User: PUTP A – DL
Mi
Mi f TP – Scaling - – TP Offset = PUTP E – DL -----------------------100 Mi
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Uplink: TX ic i
•
Peak MAC Channel Throughput:
R UL
M
i CTP P – UL
M B
i
UL = --------------------------------D Frame
In the above formula, the actual value of D Frame is used to calculate the channel throughput for coverage predictions, while D Frame = 1 sec for Monte Carlo simulations. TX i ic
For proportional fair schedulers, the channel throughput is increased by the multi-user diversity gain G MUG – UL read from the scheduler properties for the Mobility M i and the number of users connected to the cell in uplink. TX i ic
R UL Mi
B
Mi
TX ic
CTP P – UL
i UL = -------------------------------- G MUG – UL D Frame
TX i ic
Mi
Max
G MUG – UL = 1 if CINR UL CINR MUG If the multi-user diversity gain for the exact value of the number of connected users is not available in the graph, it is interpolated from the gain values available for the numbers of users just less than and just greater than the actual number of users. MIMO – SU-MIMO Gain: If the permutation zone assigned to the pixel, subscriber, or mobile Mi supports SU-MIMO or AMS, SU-MIMO gain Max
G SU – MIMO is applied to the bearer efficiency. The gain is read from the properties of the WiMAX equipment assigned to the cell TXi(ic) for: •
Mi
N Ant – TX : Number of MIMO transmission (uplink) antennas defined for the terminal used by the pixel, subscriber, or mobile Mi. TX ic i
•
N Ant – RX : Number of MIMO reception (uplink) antennas defined for the cell TXi(ic).
•
Mobility M i : Mobility used for the calculations.
•
Subchannel allocation mode used by the uplink permutation zone PZ UL assigned to the pixel, subscriber, or
Mi
mobile Mi as calculated in "Permutation Zone Selection" on page 714. •
Mi
B UL : Bearer assigned to the pixel, subscriber, or mobile Mi in the uplink as explained in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 737.
•
M
i BLER B UL : Uplink block error rate read from the graphs available in the WiMAX equipment assigned to the cell Mi
TXi(ic). BLER is determined for CINR UL . Atoll also takes into account the SU-MIMO Gain Factor f SU – MIMO defined for the clutter class where the pixel, subscriber, or mobile Mi is located. In case of SU-MIMO:
Mi
=
B UL
In case of AMS:
Mi
B UL
=
Max
Mi
1 + fSU – MIMO G SU – MIMO – 1
B UL Max
Mi
TX i ic
TX i ic
1 + f SU – MIMO G SU – MIMO – 1 if CNR Preamble T AMS
TX i ic
TX i ic
or CINR Preamble T AMS
B UL
If the Max SU-MIMO Gain for the exact value of the C/(I+N) is not available in the table, it is interpolated from the gain values available for the C/(I+N) just less than and just greater than the actual C/(I+N). MIMO – MU-MIMO Gain (for uplink throughput coverage predictions only): If the permutation zone assigned to the pixel, subscriber, or mobile Mi supports MU-MIMO and TX ic i
TX ic i
TX ic i
TX ic i
CNR Preamble T MU – MIMO and N Ant – RX 2 , the MU-MIMO gain G MU – MIMO is applied to the channel throughput. The MU-MIMO gain is read from the properties of the cell TXi(ic).
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M
i
i
TX ic i
CTP P – UL = CTP P – UL G MU – MIMO •
M
M
M
i i i Effective MAC Channel Throughput: CTP E – UL = CTP P – UL 1 – BLER B UL M
i
Mi f TP – Scaling - – TP Offset = CTP E – UL -----------------------100
Mi
Mi
•
Application Channel Throughput: CTP A – UL
•
Peak MAC Cell Capacity: Cap P – UL = CTP P – UL TL UL – Max
•
i i i Effective MAC Cell Capacity: Cap E – UL = Cap P – UL 1 – BLER B UL
•
•
Mi
TX i ic
Mi
M
Mi
Application Cell Capacity: Cap A – UL
M
M
Mi
Mi f TP – Scaling - – TP Offset = Cap E – UL -----------------------100 Mi
Mi
Peak MAC Allocated Bandwidth Throughput: ABTP P – UL
Mi
N SC – UL = CTP P – UL ----------------M Mi
PZ
N SC •
•
•
•
•
M
i UL
M
M
i i i Effective MAC Allocated Bandwidth Throughput: ABTP E – UL = ABTP P – UL 1 – BLER B UL Mi
Application Allocated Bandwidth Throughput: ABTPA – UL Mi
Peak MAC Throughput per User: PUTP P – UL
Cap M i M P – UL - ABTPP –i UL = Min ----------------------TX i ic N Users – UL
Mi
Effective MAC Throughput per User: PUTP E – UL
Mi
Mi
Mi f TP – Scaling - – TPOffset = ABTP E – UL -----------------------100 Mi
Application Throughput per User: PUTP A – UL
Cap Mi M E – UL - ABTP E –i UL = Min ---------------------- TXi ic N Users – UL Mi
Mi f TP – Scaling - – TP Offset = PUTP E – UL -----------------------100 Mi
Output Mi
•
CTP P – DL : Downlink peak MAC channel throughput at the pixel, subscriber, or mobile Mi.
•
CTP E – DL : Downlink effective MAC channel throughput at the pixel, subscriber, or mobile Mi.
•
CTP A – DL : Downlink application channel throughput at the pixel, subscriber, or mobile Mi.
•
Cap P – DL : Downlink peak MAC cell capacity at the pixel, subscriber, or mobile Mi.
•
Cap E – DL : Downlink effective MAC cell capacity at the pixel, subscriber, or mobile Mi.
•
Cap A – DL : Downlink application cell capacity at the pixel, subscriber, or mobile Mi.
•
PUTP P – DL : Downlink peak MAC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP E – DL : Downlink effective MAC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP A – DL : Downlink application throughput per user at the pixel, subscriber, or mobile Mi.
•
CTP P – UL : Uplink peak MAC channel throughput at the pixel, subscriber, or mobile Mi.
•
CTP E – UL : Uplink effective MAC channel throughput at the pixel, subscriber, or mobile Mi.
•
CTP A – UL : Uplink application channel throughput at the pixel, subscriber, or mobile Mi.
•
Cap P – UL : Uplink peak MAC cell capacity at the pixel, subscriber, or mobile Mi.
Mi M
i
Mi Mi Mi
Mi M
i
Mi
Mi Mi Mi M
i
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i
•
Cap E – UL : Uplink effective MAC cell capacity at the pixel, subscriber, or mobile Mi.
•
Cap A – UL : Uplink application cell capacity at the pixel, subscriber, or mobile Mi.
•
ABTP P – UL : Uplink peak MAC allocated bandwidth throughput at the pixel, subscriber, or mobile Mi.
•
ABTP E – UL : Uplink effective MAC allocated bandwidth throughput at the pixel, subscriber, or mobile Mi.
•
ABTP A – UL : Uplink application allocated bandwidth throughput at the pixel, subscriber, or mobile Mi.
•
PUTP P – UL : Uplink peak MAC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP E – UL : Uplink effective MAC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP A – UL : Uplink application throughput per user at the pixel, subscriber, or mobile Mi.
M
i
M
i
Mi Mi
Mi Mi Mi
10.4.8 Scheduling and Radio Resource Management Atoll WiMAX BWA module includes a number of scheduling methods which can be used for scheduling and radio resource allocation during Monte Carlo simulations. These resource allocation algorithms are explained in "Scheduling and Radio Resource Allocation" on page 748 and the calculation of user throughputs is explained in "User Throughput Calculation" on page 757.
10.4.8.1 Scheduling and Radio Resource Allocation Input TX i ic
•
TL DL – Max : Maximum downlink traffic load for the cell TXi(ic).
•
TL UL – Max : Maximum uplink traffic load for the cell TXi(ic).
•
N Users – Max : Maximum number of users defined for the cell TXi(ic).
•
QoS
TX i ic
TX i ic
M
i
M
i
: QoS class of the service (UGS, ErtPS, rtPS, nrtPS, or Best Effort) accessed by a mobile Mi.
•
p
•
TPD Min – DL : Downlink minimum throughput demand for the service accessed by a mobile Mi.
•
TPD Min – UL : Uplink minimum throughput demand for the service accessed by a mobile Mi.
•
TPD Max – DL : Downlink maximum throughput demand for the service accessed by a mobile Mi.
•
TPD Max – UL : Uplink maximum throughput demand for the service accessed by a mobile Mi.
•
•
: Priority of the service accessed by a mobile Mi. M M
i i
Mi Mi
TX ic
M
i i BLER BDL : Downlink block error rate read from the BLER vs. CINR Traffic graph available in the WiMAX equipment assigned to the terminal used by the mobile Mi. M
M
i i BLER BUL : Uplink block error rate read from the BLER vs. CINR UL graph available in the WiMAX equipment assigned
to the cell TXi(ic). Mi
•
f TP – Scaling : Throughput scaling factor defined in the properties of the service used by the mobile Mi.
•
TP Offset : Throughput offset defined in the properties of the service used by the mobile Mi.
•
CTP P – DL : Downlink peak MAC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on
Mi
Mi
page 740. •
Mi
CTP E – DL : Downlink effective MAC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on page 740.
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•
M
i
CTP P – UL : Uplink peak MAC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on page 740.
•
M
i
CTP E – UL : Uplink effective MAC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on page 740.
•
Mi
ABTP P – UL : Uplink peak MAC allocated bandwidth throughput at the mobile Mi as calculated in "Throughput Calculation" on page 740.
•
QoS
f Bias : Bias factor defined for the Biased (QoS Class) scheduling method.
Calculations The following calculations are described for any cell TXi(ic) containing the users Mi for which it is the best server. Mobile Selection: TX ic i
The scheduler selects N Users mobiles for the scheduling and RRM process. If the Monte Carlo user distribution has generated TX i ic
a number of users which is less than N Users – Max , the scheduler keeps all the mobiles generated for the cell TXi(ic). TX ic
TX ic
TX ic
i i i N Users = Min N Users – Max N Users – Generated TX ic i
Sel
N Users are selected for RRM by the scheduler.
For a cell, mobiles M i
Calculation of Actual Minimum and Maximum Throughput Demands: Depending on the selected target throughput of the scheduler assigned to the cell TXi(ic), the actual minimum and maximum throughput demands can be considered as the peak MAC, effective MAC, or application throughput. Therefore: •
Target Throughput = Peak MAC Throughput Sel Mi
Sel Mi
Downlink: TPD Min – DL , TPD Max – DL Sel
Sel
M M M i i i Uplink: TPD Min – UL , Min TPD Max – UL ABTP P – UL
•
Target Throughput = Effective MAC Throughput Sel Mi
Sel Mi
Sel Mi
Sel Mi
TPD Min – DL TPD Max – DL Downlink: TPD Min – DL = --------------------------------------------- , TPD Max – DL = --------------------------------------------Sel Sel Mi Mi 1 – BLER B DL 1 – BLER BDL Sel
Sel
Sel Mi
Sel
Mi Mi TPD Min – UL Uplink: TPD Min – UL = --------------------------------------------- , TPD Max – UL Sel Mi 1 – BLER BUL
•
Mi Mi Min TPD Max – UL ABTP P – UL = ------------------------------------------------------------------------Sel Mi 1 – BLER B UL
Target Throughput = Application Throughput Sel Mi
Sel Mi
Mi
Sel
Sel Mi
Mi
Mi TPD Min – DL + TP Offset TPD Max – DL + TP Offset - , TPD Max – DL = ----------------------------------------------------------------------------Downlink: TPD Min – DL = ----------------------------------------------------------------------------Sel Sel Mi Mi Mi Mi 1 – BLER B DL f TP – Scaling 1 – BLER B DL f TP – Scaling
Sel Mi
Sel Mi
Mi
TPD Min – UL + TP Offset Uplink: TPD Min – UL = -----------------------------------------------------------------------------, Sel Mi Mi 1 – BLER BUL f TP – Scaling
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Sel
Sel M i TPD Max – UL
M M M i i i Min TPD Max – UL ABTP P – UL + TP Offset = -------------------------------------------------------------------------------------------------Sel Mi Mi 1 – BLER BUL f TP – Scaling
The Min() function selects the lower of the two values. This calculation is performed in order to limit the maximum uplink throughput demand to the maximum throughput that a user can get in uplink using the allocated bandwidth (number of used subchannels) calculated for it in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 737. Resource Allocation for Minimum Throughput Demands: Sel
1. For the QoS classes UGS, ErtPS, rtPS, and nrtPS, Atoll sorts the M i p
Sel Mi
TX i ic
N Users in order of decreasing service priority,
: Sel
Mi
QoS
1
Sel Mi
p
UGS
2
p
Sel Mi
... n > p
:
p
:
ErtPS
:
p
p
:
rtPS
:
p
Sel Mi
Sel i
... n > p
:
p
:
nrtPS
N–1
p
p
TX i ic
=n
Sel Mi
=n > 0 ...
=0 =n
Sel Mi
Sel Mi
> 0 ...
=0
Sel i
Sel Mi
... n > p
N
M
> 0 ...
=0
Sel Mi
Sel Mi
M
=n
Sel Mi
Sel Mi
... n > p
:
Sel Mi
> 0 ...
=0
TX i ic
Where N N Users , if there are some Best Effort users, or N = N Users if there are no Best Effort users selected. Sel
2. Starting with M i
Sel
= 1 up to M i
= N , Atoll allocates the downlink and uplink resources required to satisfy each
user’s minimum throughput demands in downlink and uplink as follows: Sel Mi
Sel Mi
Sel Mi
Sel Mi
TPD Min – DL TPD Min – UL R Min – DL = -------------------------- and R Min – UL = -------------------------Sel Mi
CTP P – DL
Sel Mi
CTP P – UL
3. Atoll stops the resource allocation in downlink or uplink,
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•
When/If in downlink
M
M
Sel i
TX ic i
R Min – DL = TL DL – Max , i.e., the resources available in downlink have been used up for
Sel i
satisfying the minimum throughput demands of the mobiles. •
When/If in uplink
M
Sel i
TX ic i
R Min – UL = TL UL – Max , i.e., the resources available in uplink have been used up for
Sel Mi
satisfying the minimum throughput demands of the mobiles. 4. Mobiles which are active DL+UL must be able to get their minimum throughput demands in both UL and DL in order to be considered connected DL+UL. If an active DL+UL mobile is only able to get its minimum throughput demand in one direction, it is rejected, and the resources, that were allocated to it in the one direction in which it was able to get a throughput, are allocated to other mobiles. 5. Mobiles which are active UL and whose minimum throughput demand in UL is higher than the uplink allocated Sel Mi
Sel Mi
bandwidth throughput ( TPD Min – UL ABTP P – UL ) are rejected due to Resource Saturation. 6. If
Sel Mi
TX i ic
RMin – DL TLDL – Max
Sel Mi
Sel Mi
TX i ic
RMin – UL TLUL – Max , and all the minimum throughput resources demanded by
or
Sel Mi
the mobiles have been allocated, Atoll goes to the next step for allocating resources to satisfy the maximum throughput demands. Backhaul Saturation: If at this stage, a site’s downlink or uplink effective MAC aggregate throughput exceeds its maximum downlink or uplink backhaul throughput, respectively, mobiles are rejected one by one due to Backhaul Saturation, starting from the mobile with the lowest priority service, among all the cells of the site in order to reach a downlink or uplink effective MAC aggregate site throughput ≤ the site’s maximum downlink or uplink backhaul throughput. Resource Allocation for Maximum Throughput Demands: For each cell, the remaining cell resources available are: TX ic i
TX ic i
Downlink: R Rem – DL = TL DL – Max –
M
Sel i
R Min – DL
Sel Mi TX i ic
TX i ic
Uplink: R Rem – UL = TL UL – Max –
M
Sel Mi
R Min – UL
Sel i
For each mobile, the throughput demands remaining once the minimum throughput demands have been satisfied are the difference between the maximum and the minimum throughput demands: M
Sel i
M
Sel i
M
Sel i
Downlink: TPD Rem – DL = TPD Max – DL – TPD Min – DL Sel Mi
Sel Mi
Sel Mi
Uplink: TPD Rem – UL = TPD Max – UL – TPD Min – UL For the remaining throughput demands of the mobiles belonging to the QoS classes ErtPS, rtPS, nrtPS, and Best Effort, the following resource allocation methods are available: •
Proportional Fair: The goal of this scheduling method is to distribute resources among users fairly in such a way that, on the average, each user gets the highest possible throughput that it can get under the radio conditions at its location.
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Let the total number of users belonging to the QoS classes ErtPS, rtPS, nrtPS, and Best Effort, be N M i TX ic i
.
TX ic i
a. Each user’s channel throughput is increased by the multi-user diversity gain G MUG – DL or G MUG – UL read from the Sel
scheduler properties for the Mobility M i assigned to mobile M i
and the number of connected users, DL or
UL, in the cell TXi(ic) in the iteration k-1. Sel Mi
Sel Mi
CTP P – DL = CTP P – DL
Sel Mi
TX i ic
Without MUG Sel Mi
TX i ic
Sel Mi
G MUG – DL and CTP P – UL = CTP P – UL
Without MUG
Sel Mi
TX i ic
Max
TX i ic
G MUG – DL = 1 if CINR Traffic CINR MUG and G MUG – UL = 1 if CINR UL
G MUG – UL
Max
CINR MUG .
If the multi-user diversity gain for the exact value of the number of connected users is not available in the graph, it is interpolated from the gain values available for the numbers of users just less than and just greater than the actual number of users. b. Atoll divides the remaining resources in the cell into equal parts for each user: TX i ic
TX i ic
R Rem – DL R Rem – UL --------------------- and -------------------N N c. Atoll converts the remaining throughput demands of all the users to their respective remaining resource demands: Sel Mi
M
RD Rem – DL
Sel i
M
Sel
Sel i
Mi TPD Rem – DL TPD Rem – UL = --------------------------- and RD Rem – UL = --------------------------Sel Mi
Sel Mi
CTP P – DL
CTP P – UL
Remaining resource demands of a user are given by the ratio between its remaining throughput demands and the peak channel throughputs at the user’s location. d. The resources allocated to each user by the Proportional Fair scheduling method for satisfying its maximum throughput demands are: Sel Mi
R Max – DL
TX i ic
Sel
Sel
Sel
TX i ic
Mi Mi Mi R Rem – DL R Rem – UL - and R Max = Min RD Rem – DL -------------------– UL = Min RD Rem – UL --------------------- N N
Each user gets either the resources it needs to achieve its maximum throughput demands or an equal share from the remaining resources of the cell, whichever is smaller. e. Atoll stops the resource allocation in downlink or uplink, •
When/If in downlink
Sel Mi
M
TX i ic
R Max – DL = R Rem – DL , i.e., the resources available in downlink have been used up
Sel i
for satisfying the maximum throughput demands of the mobiles. •
When/If in uplink
Sel Mi
RMax – UL =
TX i ic
R Rem – UL , i.e., the resources available in uplink have been used up for
Sel Mi
satisfying the maximum throughput demands of the mobiles. f. If the resources allocated to a user satisfy its maximum throughput demands, this user is removed from the list of remaining users. g. Atoll recalculates the remaining resources as follows: TX i ic
TX i ic
R Rem – DL = TL DL – Max –
Sel Mi
R Min – DL –
Sel Mi TX i ic
TX i ic
R Rem – UL = TL UL – Max –
Sel Mi Sel Mi
Sel Mi
RMin – UL – RMax – UL Sel Mi
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R Max – DL and
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h. Atoll repeats the all the above steps for the users whose maximum throughput demands have not been satisfied TX ic i
TX ic i
until either R Rem – DL = 0 and R Rem – UL = 0 , or all the maximum throughput demands are satisfied. •
Proportional Demand: The goal of this scheduling method is to allocate resources to users weighted according to their remaining throughput demands. Therefore, the user throughputs for users with high throughput demands will be higher than those with low throughput demands. In other words, this scheduler distributes channel throughput between users proportionally to their demands. a. Atoll converts the remaining throughput demands of all the users to their respective remaining resource demands: Sel Mi
RD Rem – DL
Sel Mi
Sel Mi
Sel
Mi TPD Rem – DL TPD Rem – UL = --------------------------- and RD Rem – UL = --------------------------Sel Mi
Sel Mi
CTP P – DL
CTP P – UL
Remaining resource demands of a user are given by the ratio between its remaining throughput demands and the peak channel throughputs at the user’s location. b. Atoll calculates the amount effective remaining resources for the cell of each user to distribute among the users as follows: TX i ic
R Eff – Rem – DL
Sel Sel Mi TX i ic Mi TXi ic TXi ic RD Rem – DL and R Eff – Rem – UL = Min R Rem – UL RD Rem – UL = Min R Rem – DL Sel Sel Mi Mi
c. The resources allocated to each user by the Proportional Demand scheduling method for satisfying its maximum throughput demands are: Sel Mi
Sel Mi
TX i ic
Sel Mi
Sel Mi
TX i ic
RD Rem – DL RD Rem – UL - and R Max – UL = R Eff – Rem – UL ---------------------------------R Max – DL = R Eff – Rem – DL ---------------------------------Sel Sel Mi
•
Mi
RDRem – DL
RDRem – UL
Sel Mi
Sel Mi
Biased (QoS Class): The goal of this scheduling method is to distribute resources among users of each QoS class fairly in such a way that, on the average, each user gets the highest possible throughput that it can get under the radio conditions at its location. The resources available for allocation to users of each QoS class depend on a bias factor. The QoS Class Bias Factor controls the amount of resources available for each QoS class. Calculation of the Remaining Resources per QoS Class: QoS
The bias factor f Bias represents the bias in terms of resources allocated to 1 user of a QoS class with rank r to the resources allocated to 1 user of a QoS class with rank r–1: QoS
Sel Mi
Sel Mi
Sel Mi
f Bias R Max – ErtPS R Max – rtPS R Max – nrtPS = 1 + --------- = -------------------------= -------------------------= -------------------------Sel Sel Sel 100 Mi Mi Mi R Max – rtPS R Max – nrtPS R Max – BE The ranks of QoS classes are: QoS Class
QoS Class Rank r QoS
ErtPS
1
rtPS
2
nrtPS
3
Best Effort
4
The resources available for the users of each QoS class from among the remaining resources is calculated as follows:
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TX ic i
R QoS – DL
r
1 QoS 1 QoS N QoS --- N QoS --- TX ic TX ic TX ic i i i = R Rem – DL ------------------------------------------------------- and R QoS – UL = R Rem – UL ------------------------------------------------------r r 1 QoS 1 QoS N QoS --- N QoS ---
All QoS
All QoS
Resource Allocation: Once the remaining resources available for the users of each QoS class have been determined, the allocation of resources within each QoS class is performed as for the proportional fair scheduler. Sel
Let the number of users belonging to a QoS class N QoS M i
.
a. Atoll divides the remaining resources of the QoS class into equal parts for each user: TX i ic
TX i ic
R QoS – DL R QoS – UL -------------------- and ------------------N QoS N QoS b. Atoll converts the remaining throughput demands of all the users to their respective remaining resource demands: Sel Mi
Sel Mi
RD Rem – DL
Sel Mi
Sel
Mi TPD Rem – DL TPD Rem – UL = --------------------------- and RD Rem – UL = --------------------------Sel Mi
Sel Mi
CTP P – DL
CTP P – UL
Remaining resource demands of a user are given by the ratio between its remaining throughput demands and the peak channel throughputs at the user’s location. c. The resources allocated to each user by the Biased scheduling method for satisfying its maximum throughput demands are: Sel Mi
R Max – DL
TX i ic
Sel
Sel
Sel
TX i ic
Mi Mi Mi R QoS – DL R QoS – UL - and R Max = Min RD Rem – DL ------------------– UL = Min RD Rem – UL -------------------- N N QoS QoS
Each user gets either the resources it needs to achieve its maximum throughput demands or an equal share from the remaining resources of the QoS class, whichever is smaller. d. Atoll stops the resource allocation for a QoS class in downlink or uplink, •
Sel Mi
When/If in downlink
TX i ic
R Max – DL = R QoS – DL , i.e., the resources available in downlink for the QoS class have
Sel Mi
been used up for satisfying the maximum throughput demands of the mobiles. •
When/If in uplink
Sel Mi
TX i ic
R Max – UL = R QoS – UL , i.e., the resources available in uplink for the QoS class have been
Sel Mi
used up for satisfying the maximum throughput demands of the mobiles. e. If the resources allocated to a user satisfy its maximum throughput demands, this user is removed from the list of remaining users. f. Atoll recalculates the remaining resources as follows: TX i ic
TX i ic
R QoS – DL = TL DL – Max –
Sel Mi
R Min – DL –
Sel Mi TX i ic
TX i ic
R QoS – UL = TL UL – Max –
Sel Mi
R Max – DL and
Sel Mi Sel Mi
R Min – UL –
Sel Mi
Sel Mi
R Max – UL
Sel Mi
g. Atoll repeats the all the above steps for the users of the QoS class whose maximum throughput demands have not TX i ic
TX i ic
been satisfied until either R QoS – DL = 0 and R QoS – UL = 0 , or all the maximum throughput demands are satisfied. •
754
Max Aggregate Throughput:
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The goal of this scheduling method is to achieve the maximum aggregate throughput for the cells. This is done by allocating as much resources as needed to mobiles with high C/(I+N) conditions. As mobiles with high C/(I+N) can get higher bearers, and therefore require less amount of resources, more mobiles can therefore be allocated resources in the same frame, and the end-throughput for each cell will be the highest compared to other types of schedulers. Sel
a. Atoll sorts the M i
TX ic i
N Users in order of decreasing downlink or uplink traffic C/(I+N), depending on whether the
allocation is being performed for the downlink or for the uplink. b. Starting with the mobile with the highest rank, Atoll allocates the downlink and uplink resources required to satisfy each user’s remaining throughput demands in downlink and uplink as follows: Sel Mi
R Max – DL
Sel Mi
Sel Mi
Sel
Mi TPD Rem – DL TPD Rem – UL = --------------------------- and R Max – UL = --------------------------Sel Mi
Sel Mi
CTP P – DL
CTP P – UL
c. Atoll stops the resource allocation in downlink or uplink, •
When/If in downlink
M
Sel i
TX ic i
R Max – DL = R Rem – DL , i.e., the resources available in downlink have been used up
Sel Mi
for satisfying the maximum throughput demands of the mobiles. •
When/If in uplink
Sel Mi
TX i ic
R Max – UL = R Rem – UL , i.e., the resources available in uplink have been used up for
Sel Mi
satisfying the maximum throughput demands of the mobiles. •
Round Robin: The goal of this scheduling method is to allocate equal resources to users fairly. Sel
Let the total number of users belonging to the QoS classes ErtPS, rtPS, nrtPS, and Best Effort, be N M i
.
a. Atoll divides the remaining resources in the cell into equal parts for each user: TX i ic
TX i ic
R Rem – DL R Rem – UL --------------------- and -------------------N N b. Atoll converts the remaining throughput demands of all the users to their respective remaining resource demands: Sel Mi
RD Rem – DL
M
Sel i
M
Sel
Sel i
Mi TPD Rem – DL TPD Rem – UL = --------------------------- and RD Rem – UL = --------------------------M
Sel i
M
CTP P – DL
Sel i
CTP P – UL
Remaining resource demands of a user are given by the ratio between its remaining throughput demands and the peak channel throughputs at the user’s location. c. The resources allocated to each user by the Round Robin scheduling method for satisfying its maximum throughput demands are: Sel
TX i ic
Sel
Sel
Sel
TX i ic
Mi Mi Mi Mi R Rem – DL R Rem – UL - and R Max R Max – DL = Min RD Rem – DL -------------------– UL = Min RD Rem – UL --------------------- N N
Each user gets either the resources it needs to achieve its maximum throughput demands or an equal share from the remaining resources of the cell, whichever is smaller. d. Atoll stops the resource allocation in downlink or uplink, •
When/If in downlink
M
Sel Mi
TX i ic
R Max – DL = R Rem – DL , i.e., the resources available in downlink have been used up
Sel i
for satisfying the maximum throughput demands of the mobiles.
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When/If in uplink
M
M
Sel i
TX ic i
R Max – UL = R Rem – UL , i.e., the resources available in uplink have been used up for
Sel i
satisfying the maximum throughput demands of the mobiles. e. If the resources allocated to a user satisfy its maximum throughput demands, this user is removed from the list of remaining users. f. Atoll recalculates the remaining resources as follows: TX i ic
TX i ic
R Rem – DL = TL DL – Max –
Sel Mi
R Min – DL –
Sel Mi TX i ic
TX i ic
R Rem – UL = TL UL – Max –
Sel Mi
R Max – DL and
Sel Mi Sel Mi
R Min – UL –
Sel Mi
Sel Mi
R Max – UL
Sel Mi
g. Atoll repeats the all the above steps for the users whose maximum throughput demands have not been satisfied TX ic i
TX ic i
until either R Rem – DL = 0 and R Rem – UL = 0 , or all the maximum throughput demands are satisfied. Spatial Multiplexing with Uplink Multi-User MIMO: MU-MIMO lets the system/scheduler work with two parallel WiMAX frames (1 for each antenna). Therefore, a mobile connected to antenna 1 creates a corresponding resource availability on antenna 2. This resources made available on antenna 2 can then be assigned to another mobile without any effect on the overall load of the cell. When the second mobile is assigned to antenna 2, the resources allocated to it overlap with the resources made available by the first mobile on antenna 1. If the second mobile is allocated more resources than the first one made available, the second mobile will create resource availability on antenna 1. Each new mobile is either connected to antenna 1 or antenna 2. The part of the mobile’s resources which are not coupled with resources allocated to another mobile on the other antenna is called the real resource consumption. The part of the mobile’s resources which are coupled with the resources allocated to another mobile on the other antenna is called the virtual resource consumption. MU-MIMO can be used if the permutation zone assigned to the pixel, subscriber, or mobile Mi supports MU-MIMO, TX i ic
TX i ic
TX i ic
CNR Preamble T MU – MIMO , and N Ant – RX 2 . Let i be the index of connected MU-MIMO mobiles: i = 1 to N MU – MIMO
Each mobile M i MU – MIMO Mi = 0 RR UL
MU – MIMO Mi
has a corresponding traffic load TL UL
MU – MIMO Mi = 0 V UL
= 100 % and available virtual resources
. The scheduling starts with available real resources = 0 % . i = 0 means no MU-MIMO mobile has yet
been scheduled. MU – MIMO
The virtual resource consumption of a mobile M i
MU – MIMO Mi
is given by: VC UL
MU – MIMO Mi
MU – MIMO
The real resource consumption of a mobile M i
is given by: RC UL
MU – MIMO
The virtual resources made available by the mobile M i MU – MIMO Mi
V UL
MU – MIMO Mi – 1
= V UL
Saturation occurs when
MU – MIMO Mi
– VC UL
MU – MIMO Mi
RC UL
MU – MIMO
Mi = Min TL UL
MU – MIMO Mi
= TL UL
MU – MIMO Mi – 1
V UL
MU – MIMO Mi
– VC UL
are given by:
MU – MIMO Mi
+ RC UL
TX i ic
= TL UL – Max .
The following table gives an example: Mobile
756
MU – MIMO Mi
TL UL
(%)
MU – MIMO Mi
VC UL
(%)
MU – MIMO Mi
RC UL
(%)
MU – MIMO Mi
V UL
M1
10
0
10
10
M2
5
5
0
5
(%)
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M
Mobile
MU – MIMO i
TL UL
(%)
M
MU – MIMO i
VC UL
M
(%)
MU – MIMO i
RC UL
M
MU – MIMO i
V UL
(%)
M3
20
5
15
15
M4
40
15
25
25
…
…
…
…
…
(%)
Backhaul Capacity Limitation: Backhaul overflow ratios are calculated for each site as follows: Sel Sel Mi Mi R Max – DL CTP E – DL Sel M Site i = Max 1 ------------------------------------------------------------------------------------------------------- and Sel Sel Mi Mi Site R Min – DL CTP E – DL TP BH – DL – Sel M Site i
Site
BHOFDL
Sel Sel Mi Mi R Max – UL CTP E – UL Sel M i Site = Max 1 ------------------------------------------------------------------------------------------------------- Sel Sel Mi Mi Site R Min – UL CTP E – UL TP BH – UL – Sel M Site i
Site
BHOFUL
Total Amount of Resources Assigned to Each Selected Mobile: Sel
Atoll calculates the amounts of downlink and uplink resources allocated to each individual mobile M i
(which can also be
referred to as the traffic loads of the mobiles) as follows: Sel
Sel Mi
Downlink: TL DL
Sel Mi
= R DL
Sel Mi
Sel Mi
R Mi Mi Max – DL CTP P – DL R Min – DL CTP P – DL + -----------------------------------------------Site BHOF DL = -----------------------------------------------------------------------------------------------------------------Sel
Sel Mi
CTP P – DL Sel
Sel Mi
Uplink: TL UL
Sel Mi
= R UL
M
Sel i
M
Sel i
R Mi Mi Max – UL CTP P – UL R Min – UL CTP P – UL + -----------------------------------------------Site BHOF UL = -----------------------------------------------------------------------------------------------------------------Sel
Sel Mi
CTP P – UL Output
• •
Sel Mi
TL DL
Sel Mi
TL UL
Sel Mi
= R DL
Sel
: Downlink traffic load or the amount of downlink resources allocated to the mobile M i .
Sel Mi
Sel
= R UL : Uplink traffic load or the amount of uplink resources allocated to the mobile M i .
10.4.8.2 User Throughput Calculation User throughputs are calculated for the percentage of resources allocated to each mobile selected by the scheduling for RRM Sel
during the Monte Carlo simulations, M i . Input
•
Sel Mi
R DL
Sel
: Amount of downlink resources allocated to the mobile M i
as calculated in "Scheduling and Radio Resource
Allocation" on page 748.
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•
M
©Forsk 2015
Sel i
Sel
R UL : Amount of uplink resources allocated to the mobile M i
as calculated in "Scheduling and Radio Resource
Allocation" on page 748. •
Sel i CTP P – DL M
Sel
: Downlink peak MAC channel throughput at the mobile M i
as calculated in "Throughput Calculation" on
page 740. •
M
Sel i
Sel
CTP P – UL : Uplink peak MAC channel throughput at the mobile M i
as calculated in "Throughput Calculation" on
page 740. Sel
•
TX i ic Mi BLER BDL : Downlink block error rate read from the BLER vs. CINR Traffic graph available in the WiMAX equipment Sel
assigned to the terminal used by the mobile M i . Sel
•
Mi Mi BLER BUL : Uplink block error rate read from the BLER vs. CINR UL graph available in the WiMAX equipment assigned to the cell TXi(ic). Sel Mi
Sel
•
f TP – Scaling : Throughput scaling factor defined in the properties of the service used by the mobile M i
•
TP Offset : Throughput offset defined in the properties of the service used by the mobile M i
Sel Mi
Sel
Calculations Downlink: Sel Mi
Sel Mi
Sel Mi
CTP P – DL
•
Peak MAC User Throughput: UTP P – DL = R DL
•
Mi Mi Mi Effective MAC User Throughput: UTP E – DL = UTP P – DL 1 – BLER B DL
Sel
•
Sel Mi
Application User Throughput: UTP A – DL
Sel
Sel
Sel Mi
Sel Mi
Sel
Mi f TP – Scaling - – TP Offset = UTP E – DL -----------------------100
Uplink: Sel Mi
Sel Mi
Sel Mi
CTP P – UL
•
Peak MAC User Throughput: UTP P – UL = R UL
•
M M Mi i i Effective MAC User Throughput: UTP E – UL = UTP P – UL 1 – BLER B UL
Sel
•
Sel Mi
Sel
Sel Mi
Sel
Sel Mi
Sel
Mi f TP – Scaling Application User Throughput: UTP A – UL = UTP E – UL ------------------------- – TP Offset 100
Output
758
Sel Mi
Sel
•
UTP P – DL : Downlink peak MAC user throughput at the pixel, subscriber, or mobile M i
•
UTP E – DL : Downlink effective MAC user throughput at the pixel, subscriber, or mobile M i .
.
Sel Mi
Sel
Sel Mi
Sel
•
UTP A – DL : Downlink application user throughput at the pixel, subscriber, or mobile M i .
•
UTP P – UL : Uplink peak MAC user throughput at the pixel, subscriber, or mobile M i
•
UTP E – UL : Uplink effective MAC user throughput at the pixel, subscriber, or mobile M i .
•
UTP A – UL : Uplink application user throughput at the pixel, subscriber, or mobile M i
Sel Mi
Sel
.
Sel Mi Sel Mi
Sel
Sel
.
.
.
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10.5 Automatic Planning Algorithms The following sections describe the algorithms for: • • • • •
"Automatic Neighbour Planning" on page 759. "Automatic Inter-technology Neighbour Planning" on page 763. "Automatic Frequency Planning Using the AFP" on page 765. "Automatic Preamble Index Planning Using the AFP" on page 767. "Automatic Zone PermBase Planning Using the AFP" on page 771.
10.5.1 Automatic Neighbour Planning The intra-technology neighbour planning algorithm takes into account the cells of all the TBC transmitters. It means that the cells of all the TBC transmitters of your ATL document are potential neighbours. The cells to be allocated will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone, They belong to the folder on which the allocation has been executed. This can be the Transmitters folder or a group of transmitters (subfolder).
Only TBA cells are assigned neighbours. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
We assume a reference cell TXi(ic) and a candidate neighbour cell TXj(jc). When automatic planning starts, Atoll checks the following conditions: 1. The distance between both cells must be less than the user-definable maximum inter-site distance. If the distance between the reference cell and the candidate neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance between the reference cell and its candidate neighbour from the real distance between them and the azimuths of their antennas: Dist CellA CellB = D 1 + x cos – x cos Where x = 0.3% so that the maximum variation in D does not to exceed 1%. D is stated in m.
Figure 10.5: Inter-Transmitter Distance Calculation The formula above implies that two cells facing each other have a smaller effective distance than the actual distance. Candidate neighbours are ranked in the order of increasing effective distance from the reference cell. 2. The calculation options, •
•
Force Co-site Cells as Neighbours: If selected, Atoll adds all the cells located on the same site as the reference cell to the candidate neighbour list. The weight of this constraint can be defined. It is used to calculate the rank of each neighbour, and its importance. Force Adjacent Cells as Neighbours: If selected, Atoll adds all the cells geographically adjacent to the reference cell to the candidate neighbour list. The weight of this constraint can be defined. It is used to calculate the rank of each neighbour, and its importance.
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Figure 10.6: Determination of Adjacent Cells Determination of Adjacent Cells: Geographically adjacent cells are determined on the basis of their best server coverage areas. A candidate neighbour cell TXi(ic) is considered adjacent to the reference cell TXi(ic) if there exists at least one pixel of TXj(jc)’s best server coverage area where TXi(ic) is the second best server. The ranking of adjacent neighbour cells increases with the number of such pixels. Adjacent cells are sorted in the order of decreasing rank. •
Force Symmetry: If selected, Atoll adds the reference cell to the candidate neighbour list of the its candidate neighbour. A symmetric neighbour relation is allowed only if the neighbour list of the reference cell is not already full. If TXj(jc) is a neighbour of TXi(ic) but TXi(ic) is not a neighbour of TXj(jc), there can be two possibilities: i.
The neighbour list of TXj(jc) is not full, Atoll will add TXi(ic) to the end of the list.
ii. The neighbour list of TXj(jc) is full, Atoll will not be able to add TXi(ic) to the list, so it will also remove TXj(jc) from the neighbour list of TXi(ic). If the neighbours list of a cell is full, the reference cell will not be added as a neighbour of that cell and that cell will be removed from the reference cell’s neighbours list. You can force Atoll to keep that cell in the reference cell’s neighbours list by adding the following option in the Atoll.ini file: [Neighbours] DoNotDeleteSymmetrics = 1 •
Force Exceptional Pairs: This option enables you to force/forbid some neighbour relations. Exceptional pairs are pairs of cells which will always or never be neighbours of each other. If you select "Force exceptional pairs" and "Force symmetry", Atoll considers the constraints between exceptional pairs in both directions so as to respect symmetry condition. On the other hand, if neighbourhood relationship is forced in one direction and forbidden in the other, symmetry cannot be respected. In this case, Atoll displays a warning in the Event viewer.
•
Delete Existing Neighbours: If selected, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, the existing neighbours are kept in the list.
3. If the Use Coverage Conditions check box is selected, the coverage areas of TXi(ic) and TXj(jc) must have an overlap ( S TX ic S TX jc ).Otherwise, only the distance criterion is taken into account. i
j
The overlapping zone ( S TX ic S TX jc ) is defined as follows: i
•
j
Here S TX ic is the surface area covered by the cell TXi(ic) that comprises all the pixels where: i
•
The received preamble signal level is greater than or equal to the preamble signal level threshold. The received TX i ic
TX i ic
preamble signal level ( C Preamble ) and the preamble signal level threshold are calculated from CNR Preamble TX i ic
TX i ic
and T Preamble , respectively, by adding the value of the noise ( n Preamble ) to them. •
TX ic i
TX ic i
S TX ic is the surface area covered by TXi(ic) within C Preamble + HO Start and C Preamble + HO End , or i TX i ic
TX i ic
CINR Preamble + HO Start and CINR Preamble + HO End . HOStart is the margin with respect to the best preamble
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signal level or C/(I+N) at which the handover starts, and HO End is the margin with respect to the best •
preamble signal level or C/(I+N) at which the handover ends. S TX jc is the coverage area where the candidate cell TXj(jc) is the best server. j
•
•
•
TX i ic
If a global value of the preamble C/N threshold ( T Preamble ) is set in the coverage conditions dialogue, for each cell, Atoll uses the higher of the two values, i.e., global value and the value defined for that cell. For calculating the overlapping coverage areas, Atoll uses the service with the lowest body loss, the terminal that has the highest difference between gain and losses, and the shadowing margin calculated using the defined cell edge coverage probability, if the option is selected. The service and terminal are selected such that the selection gives the largest possible preamble C/N coverage areas for the cells. Atoll
S TX ic S TX jc i j When the above conditions are met, Atoll calculates the percentage of the coverage area overlap ( --------------------------------------- 100 ), S TX ic i
and compares this value with the % Min Covered Area.
Figure 10.7: Overlapping Zones S TX ic S TX jc i j TXj(jc) is considered a neighbour of TXi(ic) if --------------------------------------- 100 % Min Coverage Area . S TX ic i
Next, Atoll calculates the importance of the automatically allocated neighbours. Atoll sorts the neighbours by decreasing importance in order to keep the ones with high importance. If the maximum number of neighbours to be allocated to each cell is exceeded, Atoll keeps the ones with high importance. The neighbour importance depends on the distance from the reference transmitter and on the neighbourhood cause (cf. table below); this value varies between 0 and 100%. Neighbourhood cause
When
Importance value
Existing neighbour
Only if the Delete Existing Neighbours option is not selected and in case of a new allocation
Existing importance
Exceptional pair
Only if the Force Exceptional Pairs option is selected
100 %
Co-site cell
Only if the Force Co-site Cells as Neighbours option is selected
Importance Function (IF)
Adjacent cell
Only if the Force Adjacent Cells as Neighbours option is selected
Importance Function (IF)
Neighbourhood relationship that fulfils coverage conditions
Only if the % Min Covered Area is exceeded
Importance Function (IF)
Symmetric neighbourhood relationship
Only if the Force Neighbour Symmetry option is selected
Importance Function (IF)
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The importance is evaluated using an Importance Function (IF), which takes into account the following factors: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance ( D in m) weighted by the azimuths of antennas. d max is the maximum distance between the reference transmitter and a possible neighbour.
• • •
The co-site factor (C): a Boolean, The adjacency factor (A): the percentage of adjacency, The overlapping factor (O): the percentage of overlapping.
The minimum and maximum importance assigned to each of the above factors can be defined. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
30%
Adjacency factor (A)
Min(A)
30%
Max(A)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The Importance Function is evaluated as follows: Neighbourhood cause
Importance Function
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%Max(Di))(O)}+Min(Di)+Delta(Di)(Di)
10%+20%{10%(Di)+90%(O)}+1%+9%(Di)
No
Yes
Min(A)+Delta(A){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
30%+30%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Yes
Yes
Min(C)+Delta(C){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
60%+40%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Co-site
Adjacent
No
Where: Delta(X)=Max(X)-Min(X) • •
•
•
Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours, adjacent neighbours, and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes. The default value of Min(O) = 1% ensures that neighbours selected for symmetry will have an importance greater than 0%. With a value of Min(O) = 0%, neighbours selected for symmetry will have an importance field greater than 0% only if there is some coverage overlapping.If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes.
In the results, Atoll lists only the cells for which it finds new neighbours. Cells whose channels have the same start frequency, the same channel width, and the same total number of subcarriers are listed as intra-carrier neighbours. Otherwise, neighbour cells are listed as inter-carrier neighbours.
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•
By default, the automatic neighbour allocation compares the defined Max intersite distance with the effective inter-cell distance. As a consequence, there can be cases where the real distance between assigned neighbours is higher than the Max inter-site distance, because the effective distance is smaller. You can force Atoll to compare the Max inter-site distance with the real inter-site distance by adding the following lines in Atoll.ini: [Neighbours] RealInterSiteDistanceCondition=1
•
By default, the neighbour importance calculated with respect to distance is based on the global Max inter-site distance setting for all neighbour candidates. As a consequence, there can be cases where the calculated importance is different when the global Max inter-site distance is modified. To avoid that, you can force Atoll to prioritise the individual distances between reference cells and their respective neighbour candidates by adding the following lines in Atoll.ini: [Neighbours] CandidatesMaxDistanceInImportanceCalculation=1
10.5.2 Automatic Inter-technology Neighbour Planning The inter-technology neighbour planning algorithm takes into account all the TBC transmitters (if the other technology is GSM) or the cells of all the TBC transmitters (for any other technology than GSM). This means that all the TBC transmitters (GSM) or the cells of all the TBC transmitters (all other technologies) of the linked document are potential neighbours. The cells to be allocated in the main document will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone, They belong to the folder on which allocation has been executed. This can be the Transmitters folder or a group of transmitters (subfolder).
Only TBA cells are assigned neighbours. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
We assume a reference cell A and a candidate neighbour B. When automatic planning starts, Atoll checks following conditions: 1. The distance between reference cell and the candidate neighbour must be less than the user-definable maximum inter-site distance. If the distance is greater than this value, the candidate neighbour is discarded. Atoll calculates the effective distance between the reference cell and its candidate neighbour from the real distance between them and the azimuths of their antennas: Dist CellA CellB = D 1 + x cos – x cos Where x = 0.3% so that the maximum variation in D does not to exceed 1%. D is stated in m.
Figure 10.8: Inter-Transmitter Distance Calculation The formula above implies that two cells facing each other have a smaller effective distance than the actual distance. Candidate neighbours are ranked in the order of increasing effective distance from the reference cell. 2. The calculation options:
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•
•
• •
©Forsk 2015
CDMA Carriers: This option is available when an WiMAX network is being co-planned with a UMTS, CDMA, or TDSCDMA network. This option enables you to select the CDMA carrier(s) that you want Atoll to consider as potential neighbours of WiMAX cells. You may choose one or more carriers. Atoll will allocate only the cells using the selected carriers as neighbours. Force co-site cells as neighbours: If selected, Atoll adds all the transmitters/cells located on the same site as the reference cell in its candidate neighbour list. The weight of this constraint can be defined. It is used to calculate the rank of each neighbour and its importance. Force exceptional pairs: This option enables you to force/forbid some neighbour relations. Exceptional pairs are pairs of cells which will always or never be neighbours of each other. Delete existing neighbours: If selected, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, the existing neighbours are kept in the list.
3. Neighbour relation criterion: •
Allocation based on distance: The allocation algorithm is based on the effective distance between the reference cell and its candidate neighbour.
•
Algorithm based on coverage overlapping: The coverage areas of the reference cell A and the candidate neighbour B must overlap ( S A S B ). Two cases may exist for SA: •
1st case: SA is the area where the cell A is the best serving cell, with a 0dB margin. This means that the preamble signal received from A is greater than the minimum required (calculated from the preamble C/N threshold), and is the highest one. .
•
2nd case: The margin is other than 0dB. SA is the area where: The preamble signal level received from A exceeds the minimum required (calculated from the preamble C/N threshold) and is within a margin from the highest signal level.
Two cases may exist for SB: •
1st case: SB is the area where the candidate neighbour is the best server. In this case, the margin must be set to 0dB. The signal level received from B exceeds the minimum required, and is the highest one.
•
2nd case: The margin is other than 0dB. SB is the area where: The signal level received from B exceeds the minimum required and is within a margin from the best signal level.
SA SB Atoll calculates the percentage of the coverage area overlap ( ------------------ 100 ) and compares this value with the % SA SA SB Min Covered Area. B is considered a neighbour of A if ------------------ 100 % Min Covered Area . SA Candidate neighbours are ranked in the order of decreasing coverage area overlap percentages. Next, Atoll calculates the importance of the automatically allocated neighbours. Atoll sorts the neighbours by decreasing importance in order to keep the ones with high importance. If the maximum number of neighbours to be allocated to each cell is exceeded, Atoll keeps the ones with high importance. The importance (%) of neighbours depends on the distance and on the reason of allocation: •
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When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter/cell
If the Force co-site cells as neighbours option is selected
100 %
Neighbour relation that fulfils distance conditions
If the maximum distance is not exceeded
d1 – ---------d max
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d is the effective distance between the reference cell and the neighbour and d max is the maximum inter-site distance. •
For allocation based on coverage overlapping: Neighbour cause
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter/cell
If the Force co-site cells as neighbours option is selected
IF
Neighbourhood relationship that fulfils coverage conditions
If the % minimum covered area is exceeded
IF
The importance is evaluated using an Importance Function (IF), which takes into account the following factors: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. d max is the maximum distance between the reference transmitter and a possible neighbour.
• •
The co-site factor (C): a Boolean, The overlapping factor (O): the percentage of overlapping.
The IF is user-definable using the Min importance and Max importance fields. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The IF evaluates importance as follows: Co-site Neighbourhood cause
IF
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%-Max(Di))(O)}
10%+50%{10%(Di)+90%(O)}
Yes
Min(C)+Delta(C){Max(Di)(Di)/(Max(Di)+Max(O))+ Max(O)(O)/(Max(Di)+Max(O))}
60%+40%{1/7%(Di)+6/7%(O)}
Where Delta(X)=Max(X)-Min(X) • •
•
Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes.
In the results, Atoll displays only the cells for which it finds new neighbours.
10.5.3 Automatic Frequency Planning Using the AFP The role of an Automatic Frequency Planning (AFP) tool is to assign frequencies (channels) to cells of a network such that the overall network performance is optimised. In other words, the interference within the network is reduced as much as possible. Co-channel interference is the main reason for overall network quality degradation in WiMAX. In order to improve network performance, the WiMAX AFP tries to minimise co- and adjacent channel interference as much as possible while respecting
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any constraints input to it. The main constraints are the resources available for allocation, i.e., the number of frequencies with which the AFP can work, and the relationships to take into account, i.e., interference matrices, neighbours, and distance between transmitters. The AFP is based on a cost function which represents the interference level in the network. The aim of the AFP is to minimise the cost. The best, or optimum, frequency plan is the one which corresponds to the lowest cost. The following describes the AFP’s automatic planning method for frequencies in WiMAX networks, which takes into account interference matrices, neighbour relations, and distance between transmitters. The AFP takes into account the cells of all the TBC transmitters. The cells to be allocated will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, Their channel allocation status is not set to locked, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
10.5.3.1 Constraint and Relationship Weights The AFP is based on a cost function which takes into account channel separation constraints based on the channel overlap ratio as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 702. Channel separation is studied between each TBA cell and its related cells. Atoll calculates the cost between each individual TBA and related cell, and then the overall cost for the TBA cell. Related cells of a TBA cell are: •
Its neighbours, if the check box "Existing neighbours" is selected, Assigned weight Neighbour = 0.5
•
Cells that are listed in the interference matrix of the TBA cell, Assigned weight IM = 0.3
•
Cells within the cell’s (or the default) minimum reuse distance, if the check box "Reuse distance" is selected, Assigned weight Dis tan ce = 0.2 The sum of the weights assigned to the above relations is 1.
You can modify these weights in your WiMAX document. The absolute values of the constraint weights are calculated from the relative weights (%) defined in the Constraint Weights dialogue as follows: % Neighbour Neighbour = ---------------------------------------------------------------------------------% Neighbour + % IM + % Dis tan ce % IM IM = ---------------------------------------------------------------------------------% Neighbour + % IM + % Dis tan ce % Dis tan ce Dis tan ce = ---------------------------------------------------------------------------------% Neighbour + % IM + % Dis tan ce
10.5.3.2 Cost Calculation The cost of the relation between the TBA cell and its related cell is calculated as follows: $
TX i ic – TX j jc
TX i ic – TX j jc
= rO
TX ic – TX jc i j
Where r O page 702.
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TX i ic – TX j jc
Neighbour Neighbour
TX i ic – TX j jc
+ Dis tan ce Dis tan ce
TX ic – TX j jc
+ i IM IM
is the channel overlap ratio as calculated in "Co- and Adjacent Channel Overlaps Calculation" on
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TX ic – TX jc i j
Neighbour
is the importance of the relationship between the TBA cell and its related neighbour cell. Neighbour
is
calculated during automatic neighbour planning by Atoll as explained in "Automatic Neighbour Planning" on page 759. For manual neighbour planning, this value is equal to 1. TX ic – TX jc i j
IM
is the importance of the relationship between the TBA cell and its related interfering cell calculated as follows:
TX i ic – TX j jc
TX i ic – TX j jc
IM
= r CCO
TX i ic – TX j jc
TX i ic – TX j jc
IM – CC
and IM – CC
TX i ic – TX j jc
IM – CC
TX i ic – TX j jc
+ r ACO
TX i ic – TX j jc
IM – AC
are respectively the co- and adjacent channel interference probabilities calculated as TX ic – TX jc i j
explained in "Interference Matrix Calculation" on page 774. r CCO
TX ic – TX jc i j
and r ACO
are the co- and adjacent channel
overlap ratios as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 702. TX i ic – TX j jc
Dis tan ce
is the importance of the relationship between the TBA and its related cell with respect to the distance between
TX i ic – TX j jc
them. Dis tan ce
is calculated as explained in "Distance Importance Calculation" on page 774.
Atoll calculates the quality reduction factor for the TBA cell and its related cell from the cost calculated above as follows: QRF
TX i ic – TX j jc
= 1–$
TX i ic – TX j jc
The quality reduction factor is a measure of the cost of an individual relation. The total cost of the current frequency plan for any TBA cell is given as follows, considering all the cells with which the TBA cell has relations: TX i ic
$ Total = 1 –
QRF
TX i ic – TX j jc
TX j jc
And, the total cost of the current frequency plan for the entire network is simply the sum of the total TBA cell costs calculated above, i.e., $ Total =
TX i ic
$ Total
TX ic i
10.5.3.3 AFP Algorithm The AFP algorithm is an iterative algorithm which: • • • •
Calculates the cost (as described above) of the initial frequency plan, Tries different frequency plans in order to reduce the cost, Memorises the different frequency plans in order to determine the best one, i.e., the frequency plan which provides the lowest total cost, Stops when it is unable to improve the cost of the network, and proposes the last known best frequency plan as the solution.
10.5.4 Automatic Preamble Index Planning Using the AFP IEEE 802.16e defines 114 preamble indexes. Each preamble index, from 0 to 113, contains the following information: • • •
Segment number (0, 1, or 2), DL PermBase (0 to 31) for the obligatory first DL PUSC zone, and A pseudo-noise sequence transmitted using the subcarriers corresponding to the preamble carrier set.
The downlink subframe can be divided into a 3-segment structure, and includes a preamble which begins the transmission (the first symbol of the downlink transmission). The preamble subcarriers are divided into 3 carrier sets. There are three possible groups consisting of a carrier set each which may be used by any segment. These are defined by allocation of different subcarriers to each one of them. The subcarriers are modulated using a BPSK modulation with a specific Pseudo-Noise (PN) sequence. Preamble carrier sets are defined using equation below: PreambleCarrierSet n = n + k 3 Where PreambleCarrierSetn gives the subcarriers used by the preamble, n is the number of the preamble carrier set indexed 0, 1, or 2, k is a running index from 0 to 567 for FFT 2048, from 0 to 283 for FFT 1024, from 0 to 142 for FFT 512, and from 0 to 35 for FFT 128.
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In a WiMAX network, each base station transmits a different PN sequence, out of the 114 available, on the preamble carrier set. A mobile trying to connect to the network scans all the preamble subcarriers, listens to all the preambles (i.e., PN sequences) from all the base stations it can receive, and compares the PN sequences it is receiving with the 114 stored in its memory in order to detect the preamble index from the PN sequence. It selects the base station as its server whose preamble it receives with either the highest signal level or the highest C/(I+N). Once the best server is known, its PN sequence is used to identify its transmission. The PN sequence of the best server gives the preamble index, which in turn gives the segment number, and the IDCell (DL PermBase of the first DL PUSC zone, referred to as Cell PermBase in Atoll). Therefore, the mobile knows which subcarriers to listen to for the FCH, DCD, UCD, DL-MAP, and UL-MAP. As can be understood from the above description, if all the cells in the network transmit the same preamble index, the network will have 100% interference on downlink preambles, and it will be impossible for a mobile to identify different cells. Cell search and selection will be impossible. Therefore, it is important to intelligently plan preamble indexes to cells so as to reduce preamble interference, and allow easy recognition of cells by mobiles. The following describes the AFP’s automatic planning method for preamble indexes in a WiMAX network, which takes into account interference matrices, neighbour relations (first-order neighbours, first-order neighbours of a common WiMAX cell, and optionally second-order neighbours), distance between transmitters, and the frequency plan of the network. The AFP takes into account the cells of all the TBC transmitters. The cells to be allocated will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, Their preamble index status or segment is not set to locked, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
10.5.4.1 Constraint and Relationship Weights The AFP is based on a cost-based function which takes into account the following constraints, in the order of priority: 1. Same preamble index, Assigned weight PI = 0.75 2. Same segment number, Assigned weight Seg = 0.02 3. Same cell permbase, Assigned weight PB = 0.23 The sum of the weights assigned to the above constraints is 1.
You can modify these weights in your WiMAX document. The absolute values of the constraint weights are calculated from the relative weights (%) defined in the Constraint Weights dialogue as follows: % PI PI = -----------------------------------------------------% PI + % Seg + % PB % Seg Seg = -----------------------------------------------------% PI + % Seg + % PB % PB PB = -----------------------------------------------------% PI + % Seg + % PB The above constraints are studied between each TBA cell and its related cells. Atoll calculates the cost between each individual TBA and related cell, and then the overall cost for the TBA cell. Related cells of a TBA cell are: •
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Its neighbours, if the check box "Existing neighbours" is selected,
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Assigned weight Neighbour = 0.35 TBA cells which are first-order neighbours of a common cell are also related to each other through that cell. This relation is also taken into account, Assigned weight Inter – Neighbour = 0.15 You can choose to not take into account the preamble index collision between neighbours of a common cell by adding an option in the Atoll.ini file (see the Administrator Manual). If the collision between neighbours of a common cell is not taken into account, the weight assigned to the direct first-order neighbour relation alone is Neighbour = 0.5 and that of the collision between neighbours of a common cell is of course Inter – Neighbour = 0 . By adding an option in the Atoll.ini file (see the Administrator Manual), second-order neighbours can also be taken into account. In this case, the assigned weights are: Neighbour = 0.25 , 2nd – Neighbour = 0.15 , and Inter – Neighbour = 0.10 . •
Cells that are listed in the interference matrix of the TBA cell, Assigned weight IM = 0.3
•
Cells within the cell’s (or the default) minimum reuse distance, if the check box "Reuse distance" is selected, Assigned weight Dis tan ce = 0.2 The sum of the weights assigned to the above relations is 1.
You can modify these weights in your WiMAX document. The absolute values of the constraint weights are calculated from the relative weights (%) defined in the Constraint Weights dialogue as follows: % Neighbour Neighbour = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------% Neighbour + % Inter – Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce % Inter – Neighbour Inter – Neighbour = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------% Neighbour + % Inter – Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce % 2nd – Neighbour 2nd – Neighbour = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------% Neighbour + % Inter – Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce % IM IM = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------% Neighbour + % Inter – Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce % Dis tan ce Dis tan ce = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------% Neighbour + % Inter – Neighbour + % 2nd – Neighbour + % IM + % Dis tan ce
10.5.4.2 Cost Calculation Atoll calculates the constraint violation levels between the TBA cell TXi(ic) and its related cell TXj(jc) as follows: TX i ic – TX j jc
VL 1
TX i ic – TX j jc
VL 2
PI
PB
= PI p Coll + PB p Penalty Seg
= Seg p Coll
If TX i ic and TX i jc are co-transmitter cells, and the option Allocate Same Segment to Co-transmitter Cells has been TX i ic
selected, and N Seg
TX i jc
N Seg
TX i ic – TX j jc
, then VL 1
TX i ic – TX j jc
+ VL 2
= 1.
Where PI , Seg , and PB are the weights assigned to the preamble index, segment number, and cell permbase constraints. PI PI p Coll is the preamble index collision probability given by p Coll = 1 0
if PI if PI
TX ic i TX ic i
= PI PI
TX jc j
TX jc j
.
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Seg
p Coll is the segment number collision probability. If TX i ic and TX j jc are co-transmitter cells, and the option Allocate
Same Segment to Co-transmitter Cells has been selected,
Seg p Coll
1 = 0
PB
p Penalty
TX i ic
if N Seg
TX i ic
if N Seg
Seg p Coll
is given by
0 = 1
Seg p Coll
TX ic i
if N Seg if
TX ic i N Seg
TX jc j
= N Seg
TX jc j N Seg
. Otherwise,
TX j jc
= N Seg
TX j jc
.
N Seg
TX ic TX jc TX i ic TX j jc 1 if PB i PB j AND Site = Site PB is the cell permbase penalty given by p Penalty = TX i ic TX j jc TX i ic TX j jc if the PB AND Site Site 0.001 if PB 0 Otherwise PB
cell permbase planning strategy is set to "Same per site", and by p Penalty = 0 if the cell permbase planning strategy is set to "Free". The cell permbase penalty models the cell permbase constraint. Next, Atoll calculates the importance of the neighbour relations between the TBA cell and its related cell. TX i ic – TX j jc
Neighbours
TX i ic – TX j jc
= Neighbour Neighbour
TX i ic – TX j jc
Where Neighbour
+ Inter – Neighbour Inter – Neighbour + 2nd – Neighbour 2nd – Neighbour TX i ic – TX j jc
is the importance of the relationship between the TBA cell and its related neighbour cell. Neighbour
is calculated during automatic neighbour planning by Atoll as explained in "Automatic Neighbour Planning" on page 759. For manual neighbour planning, this value is equal to 1. Inter – Neighbour is calculated from the neighbour relationship importance values calculated during automatic neighbour planning. If two cells are neighbours of a common cell and have the same preamble index assigned, the importance of the preamble index collision is the average of their neighbour importance values with the common neighbour cell. If more than one pair of neighbours of the TBA cell has the same preamble index assigned, then the importance is the highest value among all the averages: TX i ic – TX j1 j1c
Inter – Neighbour
TX i ic – TX j2 j2c
Neighbour + Neighbour = Max --------------------------------------------------------------------------------- 2 All Neighbour Pairs with PI Collisions
Where TX j1 j1c and TX j2 j2c are two neighbours of the TBA cell TX i ic that have the same preamble index assigned. 2nd – Neighbour is calculated from the neighbour relationship importance values calculated during automatic neighbour planning. If the TBA cell has the same preamble index assigned as one of its second-order neighbours, the importance of the preamble index collision is the multiple of the importance values of the first order neighbour relations between the TBA cell and its second order neighbour. If the TBA cell is related to its second order neighbour through more than one first order neighbour, the importance is the highest value among all the multiples: 2nd – Neighbour =
TX ic – TX jc
j i Neighbour All Neighbour Pairs
Max
TX j jc – TX k kc
Neighbour
with PI Collisions
Where TX k kc is the second-order neighbour of TX i ic through TX j jc . Next, Atoll calculates the importance of the interference relations between the TBA cell and its related cell. TX i ic – TX j jc
Interference
TX i ic – TX j jc
IM
TX i ic – TX j jc
IM
TX i ic – TX j jc
= IM IM
770
TX i ic – TX j jc
f Overlap
is the importance of the relationship between the TBA cell and its related interfering cell calculated as follows: TX i ic – TX j jc
= r CCO
TX i ic – TX j jc
and IM
TX i ic – TX j jc
+ Dis tan ce Dis tan ce
TX i ic – TX j jc
IM – CC
TX i ic – TX j jc
= IM – CC
otherwise.
TX i ic – TX j jc
+ r ACO
TX i ic – TX j jc
IM – AC
if the frequency plan is taken into account
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 10: WiMAX BWA Networks
AT330_TRR_E1 TX ic – TX jc i j
TX ic – TX jc i j
IM – CC
and IM – CC
are respectively the co- and adjacent channel interference probabilities calculated as TX ic – TX jc i j
explained in "Interference Matrix Calculation" on page 774. r O
TX ic – TX jc i j
, r CCO
TX ic – TX jc i j
, and r ACO
are the total,
co-channel, and adjacent channel overlap ratios as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 702. TX i ic – TX j jc
Dis tan ce
is the importance of the relationship between the TBA and its related cell with respect to the distance between
TX i ic – TX j jc
Dis tan ce
them.
TX i ic – TX j jc
f Overlap
is
TX i ic – TX j jc
= rO
calculated
as
explained
in
"Distance
Importance TX i ic – TX j jc
if the frequency plan is taken into account and f Overlap
Calculation"
on
page 774.
= 1 otherwise.
From the constraint violation levels and the importance values of the relations between the TBA and its related cell, Atoll calculates the quality reduction factor for the pair as follows: QRF
TX i ic – TX j jc
TX i ic – TX j jc TX i ic – TX j jc TX ic – TX j jc TX i ic – TX j jc TX i ic – TX j jc TX i ic – TX j jc i = 1 – VL1 + VL 2 + VL 1 Neighbours f Overlap Interference
The quality reduction factor is a measure of the cost of an individual relation. The total cost of the current preamble index plan for any TBA cell is given as follows, considering all the cells with which the TBA cell has relations: TX i ic
$ Total = 1 –
QRF
TX i ic – TX j jc
TX j jc
And, the total cost of the current preamble index plan for the entire network is simply the sum of the total TBA cell costs calculated above, i.e., $ Total =
TX ic i
$ Total
TX i ic
10.5.4.3 AFP Algorithm The AFP algorithm is an iterative algorithm which: • • • •
Calculates the cost (as described above) of the initial preamble index plan, Tries different preamble index plans in order to reduce the cost, Memorises the different plans in order to determine the best one, i.e., which provides the lowest total cost, Stops when it is unable to improve the cost of the network, and proposes the last known best preamble index plan as the solution.
10.5.5 Automatic Zone PermBase Planning Using the AFP PermBases are numbers which are used as seeds in the permutation of subcarriers (mapping between physical and logical subcarrier numbers) and their allocation to subchannels. Subchannels in a channel contain different physical subcarriers when different permbases are used as seeds. Downlink PUSC permutation zones use 2 permbases: 1. The first DL PUSC permutation zone uses the cell permbase (mapped to the preamble index of the cell). It is called IDCell in the IEEE specifications. It is a number from 0 to 31. 2. The second DL PUSC permutation zone uses the zone permbase, also a number from 0 to 31. Other downlink permutation zones only use zone permbases. Uplink permutation zones also use only zone permbases. However, the uplink zone permbase is a number from 0 to 69. The following describes the AFP’s automatic planning method for zone permbases in a WiMAX network, which takes into account interference matrices, neighbour relations (first-order neighbours, first-order neighbours of a common WiMAX cell, and optionally second-order neighbours), distance between transmitters, and the frequency plan of the network. The AFP takes into account the cells of all the TBC transmitters. The cells to be allocated will be called TBA cells. They must fulfil the following conditions: • • •
They are active, Their zone permbase status is not set to locked, They satisfy the filter criteria applied to the Transmitters folder,
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They are located inside the focus zone.
•
In the following description, ZPB is used for the downlink zone permbases ( ZPBDL ) and uplink zone permbases ( ZPBUL ) without distinction.
•
If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
10.5.5.1 Constraint and Relationship Weights The AFP is based on a cost-based function which takes into account the following constraint: •
Same zone permbase, Assigned weight ZPB = 1
The above constraint is studied between each TBA cell and its related cells. Atoll calculates the cost between each individual TBA and related cell, and then the overall cost for the TBA cell. Related cells of a TBA cell are: •
Its neighbours, if the check box "Existing neighbours" is selected, Assigned weight Neighbour = 0.35 TBA cells which are first-order neighbours of a common cell are also related to each other through that cell. This relation is also taken into account, Assigned weight Inter – Neighbour = 0.15 You can choose to not take into account the zone permbase collision between neighbours of a common cell by adding an option in the Atoll.ini file (see the Administrator Manual). If the collision between neighbours of a common cell is not taken into account, the weight assigned to the direct first-order neighbour relation alone is Neighbour = 0.5 and that of the collision between neighbours of a common cell is of course Inter – Neighbour = 0 . By adding an option in the Atoll.ini file (see the Administrator Manual), second-order neighbours can also be taken into account. In this case, the assigned weights are: Neighbour = 0.25 , 2nd – Neighbour = 0.10 , and Inter – Neighbour = 0.15 .
•
Cells that are listed in the interference matrix of the TBA cell, Assigned weight IM = 0.3
•
Cells within the cell’s (or the default) minimum reuse distance, if the check box "Reuse distance" is selected, Assigned weight Dis tan ce = 0.2 The sum of the weights assigned to the above relations is 1.
10.5.5.2 Cost Calculation Atoll calculates the constraint violation level between the TBA cell TXi(ic) and its related cell TXj(jc) as follows: VL
TX ic – TX jc i j
ZPB
= ZPB p Coll
Where ZPB is the weight assigned to the zone permbase constraint. ZPB ZPB p Coll is the zone permbase collision probability given by p Coll = 1 0
if ZPB if ZPB
TX i ic TX i ic
= ZPB ZPB
TX j jc
TX j jc
.
Next, Atoll calculates the importance of the neighbour relations between the TBA cell and its related cell. TX i ic – TX j jc
Neighbours
772
TX i ic – TX j jc
= Neighbour Neighbour
+ Inter – Neighbour Inter – Neighbour + 2nd – Neighbour 2nd – Neighbour
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 10: WiMAX BWA Networks
AT330_TRR_E1 TX ic – TX jc i j
TX ic – TX jc i j
Where Neighbour
is the importance of the relationship between the TBA cell and its related neighbour cell. Neighbour
is calculated during automatic neighbour planning by Atoll as explained in "Automatic Neighbour Planning" on page 759. For manual neighbour planning, this value is equal to 1. Inter – Neighbour is calculated from the neighbour relationship importance values calculated during automatic neighbour planning. If two cells are neighbours of a common cell and have the same zone permbase assigned, the importance of the zone permbase collision is the average of their neighbour importance values with the common neighbour cell. If more than one pair of neighbours of the TBA cell has the same zone permbase assigned, then the importance is the highest value among all the averages: TX i ic – TX j1 j1c
TX i ic – TX j2 j2c
Neighbour + Neighbour --------------------------------------------------------------------------------- 2 All Neighbour Pairs
Inter – Neighbour =
Max
with ZPB Collisions
Where TX j1 j1c and TX j2 j2c are two neighbours of the TBA cell TX i ic that have the same zone permbase assigned. 2nd – Neighbour is calculated from the neighbour relationship importance values calculated during automatic neighbour planning. If the TBA cell has the same zone permbase assigned as one of its second-order neighbours, the importance of the zone permbase collision is the multiple of the importance values of the first order neighbour relations between the TBA cell and its second order neighbour. If the TBA cell is related to its second order neighbour through more than one first order neighbour, the importance is the highest value among all the multiples: TX ic – TX jc
j i Neighbour All Neighbour Pairs
2nd – Neighbour =
Max
TX j jc – TX k kc
Neighbour
with ZPB Collisions
Where TX k kc is the second-order neighbour of TX i ic through TX j jc . Next, Atoll calculates the importance of the interference relations between the TBA cell and its related cell. TX i ic – TX j jc
Interference
TX i ic – TX j jc
IM
TX i ic – TX j jc
IM
TX i ic – TX j jc
= IM IM
TX i ic – TX j jc
= r CCO
TX i ic – TX j jc
IM – CC
TX i ic – TX j jc
and IM
TX i ic – TX j jc
TX i ic – TX j jc
f Overlap
is the importance of the relationship between the TBA cell and its related interfering cell calculated as follows:
TX i ic – TX j jc
IM – CC
TX i ic – TX j jc
+ Dis tan ce Dis tan ce
= IM – CC
TX i ic – TX j jc
and IM – CC
TX i ic – TX j jc
+ r ACO
TX i ic – TX j jc
IM – AC
if the frequency plan is taken into account
otherwise.
are respectively the co- and adjacent channel interference probabilities calculated as TX i ic – TX j jc
explained in "Interference Matrix Calculation" on page 774. r O
TX i ic – TX j jc
, r CCO
TX i ic – TX j jc
, and r ACO
are the total,
co-channel, and adjacent channel overlap ratios as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 702. TX i ic – TX j jc
Dis tan ce them.
is the importance of the relationship between the TBA and its related cell with respect to the distance between
TX i ic – TX j jc
Dis tan ce
TX i ic – TX j jc
f Overlap
is
TX i ic – TX j jc
= rO
calculated
as
explained
in
"Distance
Importance TX i ic – TX j jc
if the frequency plan is taken into account and f Overlap
Calculation"
on
page 774.
= 1 otherwise.
From the constraint violation level and the total importance of the relation between the TBA and its related cell, Atoll calculates the quality reduction factor for the pair as follows: QRF
TX i ic – TX j jc
= 1 – VL
TX i ic – TX j jc
TX i ic – TX j jc
Interference
TX i ic – TX j jc
TX i ic – TX j jc
+ Neighbours f Overlap
The quality reduction factor is a measure of the cost of an individual relation. The total cost of the current zone permbase plan for any TBA cell is given as follows, considering all the cells with which the TBA cell has relations: TX i ic
$ Total = 1 –
QRF
TX i ic – TX j jc
TX j jc
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And, the total cost of the current zone permbase plan for the entire network is simply the sum of the total TBA cell costs calculated above, i.e.,
$ Total =
TX ic i
$ Total
TX i ic
10.5.5.3 AFP Algorithm The AFP algorithm is an iterative algorithm which: • • • •
Calculates the cost (as described above) of the initial zone permbase plan, Tries different zone permbase plans in order to reduce the cost, Memorises the different plans in order to determine the best one, i.e., which provides the lowest total cost, Stops when it is unable to improve the cost of the network, and proposes the last known best zone permbase plan as the solution.
10.5.6 Appendices 10.5.6.1 Interference Matrix Calculation The co-channel interference probability is calculated as follows: S TX ic i
TX ic – TX jc i j
IM – CC
TX j jc TX i ic n C Preamble + M Quality Preamble- --------------------------- ------------------------------------------------------------ TX i ic TX ic 10 10 T i C Preamble – 10 Log 10 + 10 Preamble
= -------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX ic i
The adjacent channel interference probability is calculated as follows: S TX ic i
TX i ic – TX j jc
IM – AC
TX j jc TX i ic TX i ic n Preamble C Preamble + M Quality + f ACS – FB ----------------------------- --------------------------------------------------------------------------------------------TX i ic TX ic 10 10 T i C Preamble – 10 Log 10 + 10 Preamble
= -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX ic i
For frequencies farther than the adjacent channel, the interference probability is 0. TX i ic
TX i ic
Here S TX ic is the best server coverage area of the cell TXi(ic), that comprises all the pixels where CNR Preamble T Preamble i
as calculated in "Service Area Calculation" on page 714. S TX ic i
TX i ic
Condition
is the best server coverage area of the cell TXi(ic)
TX j jc
where the given condition is true. C Preamble and C Preamble are the received preamble signal levels from the cells TXi(ic) and TX ic i
TXj(jc) respectively, n Preamble the preamble noise for the cell TXi(ic) as calculated in "Preamble Noise Calculation" on TX i ic
page 708, M Quality is the quality margin used for the interference matrices calculation, and f ACS – FB is the adjacent channel suppression factor defined for the frequency band of the cell TXi(ic).
10.5.6.2 Distance Importance Calculation TX i ic – TX j jc
The distance importance between two cells ( Dis tan ce
TX i ic – TX j jc
Dis tan ce
774
1 2 D Reuse = Log -------------------------------- D TXi ic – TXj jc --------------------------------------------------------2 Log D Reuse
if D
) is calculated as follows:
TX i ic – TX j jc
Otherwise
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AT330_TRR_E1
Where D Reuse is the minimum reuse distance, either defined for each TBA cell individually or set for all the TBA cells in the AFP dialogue, and D follows: D D
TX ic – TX jc i j TX i ic – TX j jc
them. d
= d
TX ic – TX jc i j
TX ic – TX jc i j
is the weighted distance between the TBA cell TXi(ic) and its related cell TXj(jc) calculated as
1 + x cos – cos – 2
is weighted according to the azimuths of the TBA cell and its related cell with respect to the straight line joining
TX i ic – TX j jc
is the distance between the two cells considering any offsets with respect to the site locations. x is set TX i ic – TX j jc
to 10 % so that the maximum variation in D due to the azimuths does not exceed 40 %. and are calculated from the azimuths of the two cells as shown in Figure 10.9 on page 775.
Figure 10.9: Weighted Distance Between Cells The above formula implies that two cells facing each other will have a shorter effective distance between them than the real distance, and two cells pointing in opposite directions will have a greater effective distance. The importance of the distance relation is explained in Figure 10.10 on page 775. This figure shows that cells that are located near (based on the effective distance which is weighted by the orientations of the cells) have high importance, which is interpreted as a high cost, and cells that are located far have low importance. Cells that are further than the reuse distance do not have any cost related to the distance relation.
Figure 10.10: Importance Based on Distance Relation
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Chapter 11 Wi-Fi Networks This chapter covers the following topics: •
"Definitions" on page 779
•
"Calculation Quick Reference" on page 782
•
"Available Calculations" on page 789
•
"Calculation Details" on page 799
•
"Automatic Planning Algorithms" on page 824
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11 Wi-Fi Networks This chapter describes all the calculations performed in Atoll Wi-Fi documents. The first part of this chapter lists all the input parameters in the Wi-Fi documents, their significance, location in the Atoll GUI, and their usage. It also contains the lists of the formulas used for the calculations. The second part describes all the calculation processes, i.e., signal level coverage predictions, point analysis calculations, signal quality coverage predictions, calculations on subscriber lists, and Monte Carlo simulations. The calculation algorithms used by these calculation processes are available in the next part. The third part describes all the calculation algorithms used in all the calculations. These algorithms include the calculation of signal levels, noise, and interference for downlink and uplink, and the radio resource management algorithms used in Monte Carlo simulations. • • •
All the calculations are performed on TBC (to be calculated) transmitters. For the definition of TBC transmitters please refer to "Path Loss Matrices" on page 103. A cell refers to a transmitter-carrier (TX-c) pair. The cell being studied during a calculation is referred to as TXi(ic) in this chapter. All the calculation algorithms in this section are described for two types of cells. •
•
A studied cell (represented by the subscript "i") comprising the studied transmitter TXi and its carrier ic. It is the cell which is currently the focus of the calculation. For example, a victim cell when calculating the interference it is receiving from other cells. • Other cells (represented by the subscript "j") comprising the other transmitter TXj and its carrier jc. The other cells in the network can be interfering cells (downlink) or the serving cells of interfering mobiles (uplink). All the calculation algorithms in this section are described for two types of receivers.
•
Mi: A pixel (coverage predictions), subscriber (calculations on subscriber lists), or mobile (Monte Carlo simulations) covered/served by the studied cell TXi(ic). • Mj: A mobile (Monte Carlo simulations) covered/served by any other cell TXj(jc). Logarithms used in this chapter (Log function) are base-10 unless stated otherwise. •
11.1 Definitions This table lists the input to calculations, coverage predictions, and simulations. Name
Value
Unit
Description
K
1.38 x 10-23
J/K
Boltzmann’s constant
T
290
K
Ambient temperature
n0
Calculation result ( 10 Log K T 1000 = – 174 dBm/Hz )
dBm/Hz
Power spectral density of thermal noise
r CP
Frame configuration or, otherwise, global parameter
None
Cyclic Prefix Ratio (guard interval) Choice List: 1/4 (long), 1/8 (short)
M PC
Global parameter
dB
Uplink power control margin
CNR Min
Global parametera
dB
Minimum signal to thermal noise threshold (interferer cutoff)
N SCa – Total
Frame configuration parameter
None
Total number of subcarriers per channel (FFT size)
N SCa – Used
Frame configuration parameter
None
Number of used subcarriers per channel
N SCa – Data
Frame configuration zone parameter
None
Number of subcarriers per channel used for data transfer
N SCa – DC
Hard-coded parameter ( N SCa – DC = 1 )
None
Number of DC subcarriers per channel
N SCa – Pilot
Calculation result ( N SCa – Pilot = N SCa – Used – N SCa – Data )
None
Number of pilot subcarriers per channel
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Name
Value
Unit
Description
N SCa – Guard
Calculation result ( N SCa – Guard = N SCa – Total – N SCa – Used – N SCa – DC )
None
Number of guard subcarriers per channel
W Channel
Frequency band parameter
MHz
Channel bandwidth
First
Frequency band parameter
None
First channel number of the frequency band
N Channel
Last
Frequency band parameter
None
Last channel number of the frequency band
F Start – FB – DL
Frequency band parameter
MHz
DL Start frequency of the frequency band
F Start – FB – UL
Frequency band parameter
MHz
UL Start frequency of the frequency band
f ACS – FB
Frequency band parameter
dB
Adjacent Channel Suppression Factor
ICS FB
Frequency band parameter
MHz
Inter-channel spacing
CN FB
Frequency band parameter
None
Channel number step
Inter – Tech
Network parameter
dB
Inter-technology interference reduction factor
B
Bearer parameter
None
Bearer index
Mod B
Bearer parameter
None
Modulation used by the bearer
CR B
Bearer parameter
None
Coding rate of the bearer
B
Bearer parameter
bits/ symbol
Bearer Efficiency
TB
Bearer parameter
dB
Bearer selection threshold
TP BH – DL
Site
Site parameter
kbps
Maximum backhaul site downlink throughput
Site
Site parameter
kbps
Maximum backhaul site uplink throughput
Transmitter parameter
dB
Transmitter noise figure
N Ant – TX
Transmitter parameter
None
Number of antennas used for MIMO in transmission
N Ant – RX
Transmitter parameter
None
Number of antennas used for MIMO in reception
TX
Antenna parameter
dB
Transmitter antenna gain
TX
Transmitter parameter
dB
Transmitter loss
N Channel
Cell parameter
None
Cell’s channel number
P DL
Cell parameter
dBm
Power
TL DL
Cell parameter
%
Downlink traffic load
TL UL
Cell parameter
%
Uplink traffic load
TL DL – Max
Cell parameter
%
Maximum downlink traffic load
TL UL – Max
Cell parameter
%
Maximum uplink traffic load
NR UL
Cell parameter
dB
Uplink noise rise
N Users – Max
Cell parameter
None
Maximum number of users per cell
N Users – DL
Cell parameter
None
Number of users connected to the cell in downlink
N Channel
f IRF
TP BH – UL nf
G L
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 11: Wi-Fi Networks
AT330_TRR_E1
Name
Value
Unit
Description
N Users – UL
Cell parameter
None
Number of users connected to the cell in uplink
T AMS
Cell parameter
dB
Adaptive MIMO switch threshold
T Min
Cell parameter
dB
Minimum C/N threshold
Inter – Tech
Cell parameter
dB
Inter-technology downlink noise rise
Inter – Tech
Cell parameter
dB
Inter-technology uplink noise rise
G SU – MIMO
Max
Cell Wi-Fi equipment parameter
None
Maximum SU-MIMO gain
G Div – UL
Cell Wi-Fi equipment parameter
dB
Uplink STTD/MRC or SU-MIMO diversity gain
p
Service parameter
None
Service priority
B DL – Highest
Service parameter
None
Highest bearer used by a service in the downlink
B UL – Highest
Service parameter
None
Highest bearer used by a service in the uplink
B DL – Lowest
Service parameter
None
Lowest bearer used by a service in the downlink
B UL – Lowest
Service parameter
None
Lowest bearer used by a service in the uplink
f Act
UL
Service parameter
%
Uplink activity factor
f Act
DL
Service parameter
%
Downlink activity factor
TPD Min – UL
Service parameter
kbps
Minimum throughput demand in the uplink
TPD Min – DL
Service parameter
kbps
Minimum throughput demand in the downlink
TPD Max – UL
Service parameter
kbps
Maximum throughput demand in the uplink
TPD Max – DL
Service parameter
kbps
Maximum throughput demand in the downlink
UL
Service parameter
kbps
Average requested throughput in the uplink
TP Average
DL
Service parameter
kbps
Average requested throughput in the downlink
TP Offset
Service parameter
kbps
Throughput offset
f TP – Scaling
Service parameter
%
Scaling factor
L Body
Service parameter
dB
Body loss
P Min
Terminal parameter
dBm
Minimum terminal power allowed
P Max
Terminal parameter
dBm
Maximum terminal power allowed
nf
Terminal parameter
dB
Terminal noise figure
G
Terminal parameter
dB
Terminal antenna gain
L
Terminal parameter
dB
Terminal loss
N Ant – TX
Terminal parameter
None
Number of antennas used for MIMO in transmission
N Ant – RX
Terminal parameter
None
Number of antennas used for MIMO in reception
Terminal Wi-Fi equipment parameter
None
Maximum SU-MIMO gain
NRDL
NRUL
TP Average
Max
G SU – MIMO
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Name
Value
Unit
Description
G Div – DL
Terminal Wi-Fi equipment parameter
dB
Downlink STTD/MRC or SU-MIMO diversity gain
UL
Clutter parameter
dB
Additional uplink diversity gain
G Div
DL
Clutter parameter
dB
Additional downlink diversity gain
f SU – MIMO
Clutter parameter
None
SU-MIMO gain factor
L Indoor
Clutter parameter
dB
Indoor loss
L Path
Propagation model result
dB
Path loss
G Div
F ICPDL
Network parameter
None
Inter-technology downlink channel protection ratio for a frequency offset F between the interfered and interfering frequency channels
M Shadowing – Model
Monte Carlo simulations: Random result calculated from model standard deviation Coverage Predictions: Result calculated from cell edge coverage probability and model standard deviation
dB
Model shadowing margin
M Shadowing – C I
Coverage Predictions: Result calculated from cell edge coverage probability and C/I standard deviation
dB
C/I shadowing margin
Any interfering cell whose signal to thermal noise ratio is less than CNR Min will be discarded.
a.
11.2 Calculation Quick Reference The following tables list the formulas used in calculations.
11.2.1 Co- and Adjacent Channel Overlaps Calculation Name TX i ic
F Start
Value TX i ic
TX i ic
TX i ic
TX i ic
TX i ic – TX j jc
TX jc
L
TX jc
TX ic
TX i ic – TX j jc H
TX ic – TX jc i j r ACO H
782
TX jc
TX ic
TX ic
j i j i i Min F End F Start – Max F Start F Start – W Channel
MHz
Start frequency for the channel number assigned to a cell
MHz
End frequency for the channel number assigned to a cell
MHz
Co-channel overlap bandwidth
None
Co-channel overlap ratio
MHz
Bandwidth of the lower-frequency adjacent channel overlap
None
Lower-frequency adjacent channel overlap ratio
MHz
Bandwidth of the higher-frequency adjacent channel overlap
None
Higher-frequency adjacent channel overlap ratio
TX i ic – TX j jc
W ACO L ---------------------------------TX i ic W Channel
L
W ACO
TX ic
Description
TX i ic – TX j jc
TX i ic – TX j jc
r ACO
TX jc
W CCO ----------------------------------TX i ic W Channel
r CCO
TX i ic – TX j jc
TX ic
j i j i Min F End F End – Max F Start F Start
TX i ic – TX j jc
W ACO
TX i ic
F Start + W Channel
F End W CCO
TXi ic – N First – TXi ic Channel Channel N ------------------------------------------------------- TX i ic CN FB
TX i ic
F Start – FB + W Channel + ICS FB
Unit
TX j jc
TX i ic
Min F End F End
TX ic
TX jc
TX ic
i j i + W Channel – Max F Start F End TX i ic – TX j jc
W ACO H ---------------------------------TX i ic W Channel
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Name
Value
Unit
Description
None
Adjacent channel overlap ratio
None
Total overlap ratio
Unit
Description
dBm
Received signal level
dBm
EIRP of a cell
Value
Unit
Description
N TXi ic SCa – Used n 0 + 10 Log ------------------------ TXi ic N SCa – Total
dBm
Thermal noise for a cell
dBm
Downlink noise for a cell
Unit
Description
dBm
Interference generated by an interfering cell
dB
Interference reduction factor due to the co- and adjacent channel overlap
dB
Interference reduction factor due to downlink traffic load
W
Downlink inter-technology interference
TX ic – TX jc i j
TX ic – TX jc i j
r ACO
r ACO
TX ic – TX jc i j
+ r ACO
L
H TX ic
i – f ACS – FB TX ic – TX jc TX ic – TX jc ---------------------------- j i j 10 r i + r ACO 10 CCO TX i ic
rO
TX j jc
if W Channel W Channel
TX i ic – TX j jc
TX ic
i – f ACS – FB TX ic TX ic – TX jc TX ic – TX jc --------------------------- W i j i j 10 Channel r i --------------------+ r ACO 10 TX j jc CCO W Channel TX i ic
TX j jc
if W Channel W Channel
11.2.2 Signal Level Calculation (DL) Name TX ic i C DL
EIRP
Value TX i ic
EIRP Traffic – L Path – M Shadowing – Model – L Indoor + G –L
Mi
Mi
Mi
Mi
– L Ant – L Body TX i ic
TX i ic
P DL
+G
TX i
–L
TX i
11.2.3 Noise Calculation (DL) Name TX i ic
n 0 – DL
TX i ic
TX i ic
n 0 – DL + nf
n DL
Mi
11.2.4 Interference Calculation (DL) Name TX j jc
I DL
TX i ic – TX j jc
fO
TX jc j
f TL – DL
Inter – Tech I DL
Value TX j jc
C DL
TX i ic – TX j jc
+ fO
TX j jc
Inter – Tech
+ f TL – DL + I DL
TX i ic – TX j jc
10 Log r O
TX j jc
10 Log TLDL
TX k P DL – Rec -------------------------------------- F TX i ic TX k TX ICP DL k
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11.2.5 C/N Calculation (DL) Name
Value TX ic i
Description
dB
Downlink C/N for a cell
Unit
Description
TX ic i
– n DL
C DL
TX ic i CNR DL
Unit
TX ic i
With MIMO: CNR DL
M
i
DL
+ G Div – DL + G Div
11.2.6 C/(I+N) Calculation (DL) Name
Value
TX i ic
TX i ic
CINR DL
C DL
TXj jc I DL -----------------10 – 10 Log 10 All TXj jc
TX i ic n DL + I Inter – Tech + -------------------10 DL 10
TX i ic
With MIMO: CINR DL
Mi
TX i ic
Downlink C/(I+N) for a cell
DL
+ G Div – DL + G Div
TX jc
I + N DL
+ NRInter – Tech DL dB
TX ic
i I j n DL DL ------------------ --------------------- 10 10 Inter – Tech + NR Inter – Tech 10 +I 10 Log + 10 DL DL All TXj jc
dBm
Total Noise (I+N) for a cell
Unit
Description
dBm
Received uplink signal level
dBm
Uplink EIRP of a user equipment
Value
Unit
Description
N TXi ic SCa – Used n 0 + 10 Log ------------------------ TXi ic N SCa – Total
dBm
Thermal noise for a cell
dBm
Uplink noise for a cell
Unit
Description
dBm
Uplink interference received at a cell
dB
Interference reduction factor due to the co- and adjacent channel overlap
11.2.7 Signal Level Calculation (UL) Name
Value Mi
EIRP UL – L Path – M Shadowing – Model – L Indoor + G
M
i C UL
–L
TX
i
M
M
i
i
– L Ant – L Body P
M
i
EIRP UL
With P
M
i
TX i
M
Mi
+G
Mi
–L
Mi
i
= P Max without power control and P
M
i
M
i
= P Eff after
power control
11.2.8 Noise Calculation (UL) Name TX i ic
n 0 – UL
TX i ic
TX i ic
n 0 – UL + nf
n UL
TX i ic
11.2.9 Interference Calculation (UL) Name Mj
I UL TX ic – TX jc i j
fO
784
Value Mj
TX i ic – TX j jc
C UL + f O
Mj
+ f TL – UL
TX i ic – TX j jc
10 Log r O
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AT330_TRR_E1
Name M
Value M
j 10 Log TL UL
j
f TL – UL
TX i ic
NR UL
TX i ic
I + N UL
Unit
Description
dB
Interference reduction factor due to the interfering mobile’s uplink traffic load
TX i ic IMj n UL UL non-seg M --------------------- TX i ic --------------------------------------------i Inter – Tech 10 10 Log + NR UL – n UL dB 10 10 + 10 All M j All TX j jc
TX i ic
TX i ic
Uplink noise at a cell
dBm
Total Noise (I+N) for a cell
Unit
Description
dB
Uplink C/N at a cell
Unit
Description
dB
Uplink C/(I+N) at a cell
Unit
Description
W Channel 10 -----------------------------------TX i ic N SCa – Total
kHz
Inter-subcarrier distance
1 ------------------TX i ic F
sec
Useful symbol duration
sec
Cyclic prefix duration
sec
Symbol duration
Symbols
Total cell resources
NRUL
+ n UL
11.2.10 C/N Calculation (UL) Name
Value
M
C UL – n UL
TX i ic
Mi
i
CNR UL
TX i ic
Mi
With MIMO: CNR UL + G Div – UL +
UL G Div
11.2.11 C/(I+N) Calculation (UL) Name
Value TX i ic
Mi
Mi
CINR UL
CNR UL – NR UL Mi
TX i ic
UL
With MIMO: CINR UL + G Div – UL + G Div
11.2.12 Calculation of Total Cell Resources Name
F
TX i ic
TX i ic
D Sym – Useful
Value TX i ic
TX i ic
TX i ic
r CP -------------F
D CP
TX i ic
D Symbol TX i ic
R DL
6
TX i ic
TX i ic
D Sym – Useful + D CP
TX ic 1 - N SCai – Data Floor ----------------TX i ic D Symbol
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11.2.13 Channel Throughput, Cell Capacity, and Per-user Throughput Calculation Name
Value TX i ic
R DL M
i
CTP P – DL
With MIMO (AMS): B
Mi
B
Mi
1 + f SU – MIMO G SU – MIMO – 1
if CNR DL M
M
Mi
Mi Mi f TP – Scaling - – TP Offset CTP E – DL -----------------------100
Mi
Mi
TX i ic
Mi
CTP P – DL TL DL – Max M
M
Mi
i i Cap P – DL 1 – BLER BDL
Mi
Mi f TP – Scaling - – TP Offset Cap E – DL -----------------------100
Cap E – DL
Cap A – DL
PUTP P – DL
PUTP E – DL
Mi
Mi Mi f TP – Scaling - – TPOffset PUTP E – DL -----------------------100 TX i ic
R UL Mi
CTP P – UL
With MIMO (AMS):
Mi
=
B UL
1 + f SU – MIMO G SU – MIMO – 1
M
Mi f TP – Scaling - – TP Offset CTP E – UL -----------------------100
Mi
Mi
TX i ic
Mi
CTP P – UL TL UL – Max M
M
Mi
i i Cap P – UL 1 – BLER B UL
M
Mi f TP – Scaling - – TP Offset Cap E – UL -----------------------100
i
Cap A – UL
786
M
M
Cap E – UL
kbps
Downlink effective MAC cell capacity
kbps
Downlink application cell capacity
kbps
Downlink peak MAC throughput per user
kbps
Downlink effective MAC throughput per user
kbps
Downlink application throughput per user
kbps
Uplink peak MAC channel throughput
kbps
Uplink effective MAC channel throughput
kbps
Uplink application channel throughput
kbps
Uplink peak MAC cell capacity
kbps
Uplink effective MAC cell capacity
kbps
Uplink application cell capacity
TX i ic
i i CTP P – UL 1 – BLER B UL
Mi
Downlink peak MAC cell capacity
T AMS
Mi
Cap P – UL
kbps
B UL TX i ic
i CTP A – UL
Downlink application channel throughput
Mi B UL Max
Mi
if CNR DL CTP E – UL
kbps
Mi
Cap E – DL ----------------------TX i ic N Users – DL
Mi
Mi
Downlink effective MAC channel throughput
Mi
Cap P – DL ----------------------TX i ic N Users – DL
Mi
PUTP A – DL
Mi
Mi
kbps
TX i ic
i i CTP P – DL 1 – BLER B DL
Cap P – DL
Downlink peak MAC channel throughput
T AMS
Mi
CTP A – DL
kbps
DL
TX i ic
CTP E – DL
Description
M i B DL Max
=
DL
Unit
Mi
Mi
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Name
Value M
M
i PUTP P – UL
PUTP E – UL
Mi
PUTP A – UL
Description
kbps
Uplink peak MAC throughput per user
kbps
Uplink effective MAC throughput per user
kbps
Uplink application throughput per user
i
Cap P – UL ----------------------TX ic i N Users – UL M
Mi
Unit
i
Cap E – UL ----------------------TX ic i N Users – UL Mi
M M f TP – Scaling i i - – TP Offset PUTP E – UL -----------------------100
11.2.14 Scheduling and Radio Resource Management Name
Value
Unit
Description
Sel Mi R Min – DL
TPD Min – DL ---------------------------
None
Resources allocated to a mobile to satisfy its minimum throughput demand in downlink
Sel Mi R Min – UL
TPD Min – UL ---------------------------
None
Resources allocated to a mobile to satisfy its minimum throughput demand in uplink
None
Remaining downlink cell resources after allocation for minimum throughput demands
R Min – UL
None
Remaining uplink cell resources after allocation for minimum throughput demands
Sel Mi
Sel Mi
kbps
Remaining throughput demand for a mobile in downlink
Sel Mi
Sel Mi
kbps
Remaining throughput demand for a mobile in uplink
None
Remaining resource demand for a mobile in downlink
None
Remaining resource demand for a mobile in uplink
None
Resources allocated to a mobile to satisfy its maximum throughput demand in downlink
None
Resources allocated to a mobile to satisfy its maximum throughput demand in uplink
Sel Mi
Sel Mi CTP P – DL Sel Mi
Sel Mi
CTP P – UL TX i ic
R Rem – DL
TX i ic
R Rem – UL Sel Mi
TPD Rem – DL Sel Mi
TPD Rem – UL Sel Mi RD Rem – DL
TX i ic
TL DL – Max –
Sel Mi
R Min – DL
Sel Mi TX ic i
TL DL – Max –
M
Sel i
Sel Mi
TPD Max – DL – TPD Min – DL TPD Max – UL – TPD Min – UL Sel Mi
TPD Rem – DL ---------------------------Sel Mi
CTP P – DL Sel Mi
Sel Mi RD Rem – UL
TPD Rem – UL ----------------------------
Sel i R Max – DL
Mi R Rem – DL - Min RD Rem – DL -------------------N
M
Sel Mi
R Max – UL
Sel Mi CTP P – UL Sel
Sel
TX i ic
TX i ic
R Rem – UL Mi - Min RD Rem – UL -------------------N
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Name
Value
Unit
Description
Sel Sel M Mi i R Max – DL CTP E – DL Sel M Site i - Max 1 ----------------------------------------------------------------------------------------------------- Sel Sel M Mi Site i TP – R CTP Min – DL BH – DL E – DL Sel M i Site
None
Site backhaul overflow ratio in downlink
Sel Sel Mi Mi R Max – UL CTP E – UL Sel M i Site Max 1 ------------------------------------------------------------------------------------------------------- Sel Sel Mi Mi Site R Min – UL CTP E – UL TP BH – UL – Sel M i Site
None
Site backhaul overflow ratio in uplink
None
Total resources assigned to a mobile in downlink (Downlink traffic load of the mobile)
None
Total resources assigned to a mobile in uplink (Uplink traffic load of the mobile)
Unit
Description
kbps
Downlink peak MAC user throughput
kbps
Downlink effective MAC user throughput
kbps
Downlink application user throughput
kbps
Uplink peak MAC user throughput
kbps
Uplink effective MAC user throughput
kbps
Uplink application user throughput
Site
BHOF DL
Site
BHOF DL
Sel
Sel i TL DL M
=
Sel i R DL M
Sel Mi
Sel Mi
R Mi Mi Max – DL CTP P – DL R Min – DL CTP P – DL + -----------------------------------------------Site BHOF DL -----------------------------------------------------------------------------------------------------------------Sel
Sel Mi
CTP P – DL Sel
Sel Mi
TL UL
Sel Mi
= R UL
M
Sel i
M
Sel i
Mi Mi R Max – UL CTP P – UL R Min – UL CTP P – UL + -----------------------------------------------Site BHOF UL -----------------------------------------------------------------------------------------------------------------Sel
Sel Mi
CTP P – UL
11.2.15 User Throughput Calculation Name Sel Mi
UTP P – DL Sel Mi
UTPE – DL Sel Mi
UTP A – DL M
Sel i
UTP P – UL Sel Mi
UTP E – UL Sel Mi
UTP A – UL
788
Value Sel Mi
R DL
Sel Mi
CTP P – DL
Sel
Sel
Mi Mi UTP P – DL 1 – BLER B DL Sel i f TP – Scaling M
Sel Mi
Sel Mi
UTP E – DL ------------------------- – TP Offset 100 M
Sel i
R UL
M
Sel i
CTP P – UL
Sel
Sel
Mi Mi UTPP – UL 1 – BLER B UL
Sel Mi
Sel Mi
Sel
Mi f TP – Scaling - – TP Offset UTP E – UL -----------------------100
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11.3 Available Calculations 11.3.1 Point Analysis 11.3.1.1 Profile View The point analysis profile view displays the following calculation results for the selected transmitter based on the calculation algorithm described in "Signal Level Calculation (DL)" on page 803.
L
M
i
TX ic i
•
Downlink signal level C DL
•
Path loss L Path
•
Total losses L Total
,G
M
i
M
i
M
i
, L Ant , and L Body are not used in the calculations performed for the profile view.
11.3.1.2 Reception View Analysis provided in the reception view is based on path loss matrices. So, you can display received signal levels from the cells for which calculated path loss matrices are available. Reception level bar graphs show the signal levels or C/N in decreasing order. The maximum number of bars in the graph depends on the signal level of the best server. The bar graph displays cells whose received signal levels are higher than their C/N thresholds and are within a 30 dB margin from the highest signal level. You can use a value other than 30 dB for the margin from the highest signal level, for example a smaller value for improving the calculation speed. For more information on defining a different value for this margin, see the Administrator Manual.
11.3.1.3 Interference View Analysis provided in the interference view is based on path loss matrices. So, you can display the received signal level from the best server and interfering signal levels from other cells for which calculated path loss matrices are available. For each cell, Atoll displays the best server signal level and interference from other cells. Interference level bar graphs show the interference levels in decreasing order. The maximum number of bars in the graph depends on the highest interference level. The bar graph displays cells whose C/N are higher than the minimum interferer C/ N threshold and whose interference levels are within a 30 dB margin from the highest interference level. You can use a value other than 30 dB for the margin from the highest interference level, for example a smaller value for improving the calculation speed. For more information on defining a different value for this margin, see the Administrator Manual.
11.3.2 Coverage Predictions 11.3.2.1 Signal Level Coverage Predictions The following coverage predictions are based on the received signal levels: • • •
Coverage by Transmitter Coverage by Signal Level Overlapping Zones
For these calculations, Atoll calculates the received signal level, then determines the selected display parameter on each pixel inside the cell’s calculation area. Each pixel within the calculation area of TXi(ic) is considered a non-interfering receiver. L
Mi
,G
Mi
Mi
Mi
, L Ant , and L Body are not considered in the calculations performed for the signal level based coverage predictions.
The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). For more information on signal level calculations, see "Signal Level Calculation (DL)" on page 803 For more information on coverage area determination and available display options, see: • •
"Coverage Area Determination" on page 790. "Coverage Display Types" on page 790.
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Coverage Area Determination Atoll uses parameters entered in the Condition tab of the coverage prediction properties dialogue to determine coverage areas to display. There are three possibilities. •
All Servers The coverage area of each cell TXi(ic) corresponds to the pixels where. TX ic i
MinimumThreshold C DL •
TX ic
TX ic
i i or L Total or L Path MaximumThreshold
Best Signal Level and a Margin The coverage area of each cell TXi(ic) corresponds to the pixels where. TX ic i
MinimumThreshold C DL
TX ic
TX ic
i i or L Total or L Path MaximumThreshold
AND TX ic i
C DL
TX jc j Best C DL – M ji
Where M is the specified margin (dB). The Best function considers the highest value from a list of values. If M = 0 dB, Atoll considers pixels where the received signal level from TXi(ic) is the highest. If M = 2 dB, Atoll considers pixels where the received signal level from TXi(ic) is either the highest or within a 2 dB margin from the highest. If M = -2 dB, Atoll considers pixels where the received signal level from TXi(ic) is 2 dB higher than the received
• • •
signal levels from the cells which are 2nd best servers. •
Second Best Signal Level and a Margin The coverage area of each cell TXi(ic) corresponds to the pixels where. TX i ic
MinimumThreshold C DL
TX ic
TX ic
i or L i Total or L Path MaximumThreshold
AND TX i ic
C DL
TX jc
nd j 2 Best C DL ji
–M
Where M is the specified margin (dB). The 2nd Best function considers the second highest value from a list of values. • • •
If M = 0 dB, Atoll considers pixels where the received signal level from TXi(ic) is the second highest. If M = 2 dB, Atoll considers pixels where the received signal level from TXi(ic) is either the second highest or within a 2 dB margin from the second highest. If M = -2 dB, Atoll considers pixels where the received signal level from TXi(ic) is 2 dB higher than the received signal levels from the cells which are 3rd best servers.
Coverage Display Types A pixel of a coverage area is coloured if the calculated value of the selected display parameter is greater than or equal to the defined thresholds values. Coverage consists of several independent layers that can be displayed and hidden on the map. It is possible to display the coverage predictions with colours depending on any transmitter or cell attribute, and other criteria such as: • • • • • • •
790
Signal Level (dBm, dBµV, dBµV/m) Best Signal Level (dBm, dBµV, dBµV/m): Where cell coverage areas overlap, Atoll keeps the highest value of the signal level. Path Loss (dB) Total Losses (dB) Best Server Path Loss (dB): Where cell coverage areas overlap, Atoll determines the best cell (i.e., the cell with the highest signal level) and evaluates the path loss from this cell. Best Server Total Losses (dB): Where cell coverage areas overlap, Atoll determines the best cell (i.e., the cell with the highest signal level) and evaluates the total losses from this cell. Number of Servers: Atoll evaluates the number of cells that cover a pixel (i.e., the pixel falls within the coverage areas of these cells).
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11.3.2.2 Effective Signal Analysis Coverage Predictions The following coverage predictions are based on the received signal levels and noise, and take into account the receiver characteristics ( L • •
M
i
,G
M
i
M
i
M
i
, L Ant , and L Body ) when calculating the required parameter:
Effective Signal Analysis (DL) Effective Signal Analysis (UL)
For these calculations, Atoll calculates the received signal level or C/N level at each pixel. Each pixel within the calculation area of TXi(ic) is considered a non-interfering receiver. The properties of the non-interfering probe receiver are set by selecting a terminal, a mobility type, and a service. The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). For more information on signal level calculations, see: • •
"Signal Level Calculation (DL)" on page 803. "Signal Level Calculation (UL)" on page 809.
For more information on C/N level calculations, see: • •
"C/N Calculation (DL)" on page 806. "C/N Calculation (UL)" on page 812.
For more information on coverage area determination and available display options, see: • •
"Coverage Area Determination" on page 791. "Coverage Display Types" on page 791.
Coverage Area Determination These coverage predictions are all best server coverage predictions, i.e., the coverage area of each cell comprises the pixels where the cell is the best server. Best server for each pixel is calculated as explained in "Best Server Determination" on page 815. Coverage Display Types A pixel of a coverage area is coloured if the calculated value of the selected display type parameter is greater than or equal to the defined thresholds values. Coverage consists of several independent layers that can be displayed and hidden on the map. It is possible to display the Effective Signal Analysis (DL) coverage prediction with colours depending on the following display options: • •
Signal Level (DL) (dBm) C/N Level (DL) (dB)
It is possible to display the Effective Signal Analysis (UL) coverage prediction with colours depending on the following display options: • •
Signal Level (UL) (dBm) C/N Level (UL) (dB)
11.3.2.3 C/(I+N)-based Coverage Predictions The following coverage predictions are based on the received signal levels, total noise, and interference. • • • • • • • •
Coverage by C/(I+N) Level (DL) Service Area Analysis (DL) Coverage by Throughput (DL) Coverage by Quality Indicator (DL) Coverage by C/(I+N) Level (UL) Service Area Analysis (UL) Coverage by Throughput (UL) Coverage by Quality Indicator (UL)
These coverage predictions take into account the receiver characteristics ( L
Mi
,G
Mi
Mi
Mi
, L Ant , and L Body ) when calculating the
required parameter. For these calculations, Atoll calculates the received signal level, noise, and interference at each pixel. Each pixel within the calculation area of TXi(ic) is considered a non-interfering receiver. The properties of the non-interfering probe receiver are set by selecting a terminal, a mobility type, and a service.
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The downlink coverage predictions are based on the downlink traffic loads of the cells, and the uplink coverage predictions are based on the uplink noise rise values. These parameters can either be calculated by Atoll during the Monte Carlo simulations, or set manually by the user for all the cells. The resolution of the coverage prediction does not depend on the resolutions of the path loss matrices or the geographic data and can be defined separately for each coverage prediction. Coverage predictions are generated using a bilinear interpolation method from multi-resolution path loss matrices (similar to the one used to calculate site altitudes, see "Path Loss Calculation Prerequisites" on page 57 for more information). For more information on C/(I+N), (I+N), and bearer calculations, see: • • •
"C/(I+N) and Bearer Calculation (DL)" on page 807. "C/(I+N) and Bearer Calculation (UL)" on page 813. "Noise Rise Calculation (UL)" on page 811
For more information on throughput calculations, see: •
"Channel Throughput, Cell Capacity, and Per-user Throughput Calculation" on page 817.
For more information on coverage area determination and available display options, see: • •
"Coverage Area Determination" on page 792. "Coverage Display Types" on page 792.
Coverage Area Determination These coverage predictions are all best server coverage predictions, i.e., the coverage area of each cell comprises the pixels where the cell is the best server. Best server for each pixel is calculated as explained in "Best Server Determination" on page 815. Coverage Display Types A pixel of a coverage area is coloured if the calculated value of the selected display type parameter is greater than or equal to the defined thresholds values. Coverage consists of several independent layers that can be displayed and hidden on the map. It is possible to display the Coverage by C/(I+N) Level (DL) coverage prediction with colours depending on the following display options: • •
C/(I+N) Level (DL) (dB) Total Noise (I+N) (DL) (dBm)
It is possible to display the Service Area Analysis (DL) coverage prediction with colours depending on the following display options: • • •
Bearer (DL) Modulation (DL): Modulation used by the bearer Service
It is possible to display the Coverage by Throughput (DL) coverage prediction with colours depending on the following display options: • • • • • • • • •
Peak MAC Channel Throughput (DL) (kbps) Effective MAC Channel Throughput (DL) (kbps) Application Channel Throughput (DL) (kbps) Peak MAC Cell Capacity (DL) (kbps) Effective MAC Cell Capacity (DL) (kbps) Application Cell Capacity (DL) (kbps) Peak MAC Throughput per User (DL) (kbps) Effective MAC Throughput per User (DL) (kbps) Application Throughput per User (DL) (kbps)
It is possible to display the Coverage by Quality Indicator (DL) coverage prediction with colours depending on the following display options: •
Quality indicators available in the document (Quality Indicators table): Atoll calculates the downlink C/(I+N) levels received from the best serving cells at each pixel of their coverage areas. From the C/(I+N), Atoll determines the best bearer available on each pixel. Then, for the calculated C/(I+N) and bearer, it determines the value of the selected quality indicator from the quality graphs defined in the Wi-Fi equipment of the selected terminal.
It is possible to display the Coverage by C/(I+N) Level (UL) coverage prediction with colours depending on the following display options: • • •
792
C/(I+N) Level (UL) (dB) Total Noise (I+N) (UL) (dBm) Transmission Power (UL) (dBm)
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It is possible to display the Service Area Analysis (UL) coverage prediction with colours depending on the following display options: • • •
Bearer (UL) Modulation (UL): Modulation used by the bearer Service
It is possible to display the Coverage by Throughput (UL) coverage prediction with colours depending on the following display options: • • • • • • • • •
Peak MAC Channel Throughput (UL) (kbps) Effective MAC Channel Throughput (UL) (kbps) Application Channel Throughput (UL) (kbps) Peak MAC Cell Capacity (UL) (kbps) Effective MAC Cell Capacity (UL) (kbps) Application Cell Capacity (UL) (kbps) Peak MAC Throughput per User (UL) (kbps) Effective MAC Throughput per User (UL) (kbps) Application Throughput per User (UL) (kbps)
It is possible to display the Coverage by Quality Indicator (UL) coverage prediction with colours depending on the following display options: •
Quality indicators available in the document (Quality Indicators table): Atoll calculates the uplink C/(I+N) levels received at the best serving cells from each pixel of their coverage areas. From the C/(I+N), Atoll determines the best bearer available on each pixel. Then, for the calculated C/(I+N) and bearer, it determines the value of the selected quality indicator from the quality graphs defined in the Wi-Fi equipment of the best serving cell.
11.3.3 Calculations on Subscriber Lists When calculations are performed on a list of subscribers by running the Automatic Server Allocation, Atoll calculates the path loss again for the subscriber locations and heights because the subscriber heights can be different from the default receiver height used for calculating the path loss matrices. Atoll calculates the following parameters for each subscriber in the list whose Lock Status is set to None. •
Serving Base Station and Reference Cell as described in "Best Server Determination" on page 815.
Atoll calculates the following parameters for each subscriber in the list that has a serving base station assigned and whose Lock Status is set to None or Server. • •
Azimuth ( ): Angle with respect to the north for pointing the subscriber terminal antenna towards its serving base station. Mechanical Downtilt ( ): Angle with respect to the horizontal for pointing the subscriber terminal antenna towards its serving base station.
Atoll calculates the remaining parameters for each subscriber in the list that has a serving base station assigned, using the properties of the default terminal and service. For more information, see: • • • • • •
"Signal Level Calculation (DL)" on page 803. "C/(I+N) and Bearer Calculation (DL)" on page 807. "Signal Level Calculation (UL)" on page 809. "Noise Rise Calculation (UL)" on page 811. "C/(I+N) and Bearer Calculation (UL)" on page 813. "Throughput Calculation" on page 816.
11.3.4 Monte Carlo Simulations The simulation process is divided into two steps. •
Generating a realistic user distribution as explained in "User Distribution" on page 793. Atoll generates user distributions as part of the Monte Carlo algorithm based on traffic data. The resulting user distribution complies with the traffic database and maps selected when creating simulations.
•
Scheduling and Radio Resource Management as explained under "Simulation Process" on page 797.
11.3.4.1 User Distribution During each simulation, Atoll performs two random trials. The first random trial generates the number of users and their activity status as explained in the following sections depending on the type of traffic input. •
"Simulations Based on User Profile Traffic Maps and Subscriber Lists" on page 794.
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"Simulations Based on Sector Traffic Maps" on page 795.
Once all the user characteristics have been determined, a second random trial is performed to obtain their geographical locations weighted according to the clutter classes, and whether they are indoor or outdoor according to the percentage of indoor users per clutter class. Atoll determines the total number of users attempting connection in each simulation based on the Poisson distribution. This may lead to slight variations in the total numbers of users in different simulations. To have the same total number of users in each simulation of a group, add the following lines in the Atoll.ini file: [Simulation] RandomTotalUsers=0
11.3.4.1.1
Simulations Based on User Profile Traffic Maps and Subscriber Lists User profile environment based traffic maps: Each pixel of the map is assigned an environment class which contains a list of user profiles with an associated mobility type and a given density, i.e., number of users of a user profile per km². User profile traffic maps: Each polygon or line of the map is assigned a density of users with a given user profile and mobility type. If the map is composed of points, each point is assigned a number of users with given user profile and mobility type. Fixed subscribers listed in subscriber lists have a user profile assigned to each of them. User profiles model the behaviour of the different user categories. Each user profile contains a list of services and parameters describing how these services are accessed by the user. The number of users of each user profile is calculated from the surface area (SEnv) of each environment class map (or each polygon) and the user profile density (DUP). N Users = S Env D UP •
In case of user profile traffic maps composed of lines, the number of users of each user profile is calculated from the line length (L) and the user profile density (DUP)
•
The number of users is a direct input when a user profile traffic map is composed of points.
(users per km): N Users = L D UP
Atoll calculates the probability for a user being active at a given instant in the uplink and in the downlink according to the service usage characteristics described in the user profiles, i.e., the number of voice calls or data sessions, the average duration of each voice call, or the volume of the data transfer in the uplink and the downlink in each data session. Voice Service (v) User profile parameters for voice type services are: • •
The user terminal equipment used for the service (from the Terminals table). The average number of calls per hour N Call .
•
The average duration of a call (seconds) D Call .
N Call D Call Calculation of the service usage duration per hour ( p 0 : probability of an active call): p 0 = ---------------------------3600 Calculation of the number of users trying to access the service v ( n v ): n v = N Users p 0 The activity status of each user depends on the activity periods during the call, i.e., the uplink and downlink activity UL
DL
factors defined for the voice type service v, f Act and f Act . Calculation of activity probabilities: UL
DL
Probability of being inactive: p Inactive = 1 – f Act 1 – f Act UL
UL
DL
Probability of being active in the uplink: p Active = f Act 1 – f Act DL
DL
UL
Probability of being active in the downlink: p Active = f Act 1 – f Act UL + DL
UL
DL
Probability of being active in the uplink and downlink both: p Active = f Act f Act
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Calculation of number of users per activity status: Number of inactive users: n v – Inactive = n v p Inactive UL
UL
Number of users active in the uplink: n v – Active = n v p Active DL
DL
Number of users active in the downlink: n v – Active = n v p Active UL + DL
UL + DL
Number of users active in the uplink and downlink both: n v – Active = n v p Active
Therefore, a user can be either active on both links, inactive on both links, active on UL only, or active on DL only. Data Service (d) User profile parameters for data type services are: • •
The user terminal equipment used for the service (from the Terminals table). The average number of data sessions per hour N Session .
•
The average data volume (in kBytes) transferred in the downlink V
•
The average throughputs in the downlink
Calculation of activity probabilities: f
UL
DL TP Average
DL
and the uplink
and the uplink V
UL TP Average
UL
during a session.
for the service d.
UL
DL
N Session V 8 N Session V 8 DL = ------------------------------------------ and f = -----------------------------------------UL DL TP Average 3600 TP Average 3600 UL
DL
Probability of being inactive: p Inactive = 1 – f 1 – f UL
Probability of being active in the uplink: p Active = f DL
UL
DL
1 – f
Probability of being active in the downlink: p Active = f
DL
UL
1 – f UL + DL
Probability of being active in the uplink and downlink both: p Active = f
UL
f
DL
Calculation of number of users: Number of inactive users: n d – Inactive = N Users p Inactive UL
UL
Number of users active in the uplink: n d – Active = N Users p Active DL
DL
Number of users active in the downlink: n d – Active = N Users p Active UL + DL
UL + DL
Number of users active in the uplink and downlink both: n d – Active = N Users p Active Calculation of the number of active users trying to access the service d (nd): UL
DL
UL + DL
n d = n d – Active + n d – Active + n d – Active The user distribution per service and the activity status distribution between the users are average distributions. The service and the activity status of each user are randomly drawn in each simulation. Therefore, if you calculate several simulations at once, the average number of users per service and average numbers of inactive, active on UL, active on DL and active on UL and DL users, respectively, will correspond to calculated distributions. But if you check each simulation, the user distribution between services as well as the activity status distribution between users can be different in each of them.
11.3.4.1.2
Simulations Based on Sector Traffic Maps Sector traffic maps per sector are also referred to as live traffic maps. Live traffic data from the OMC is spread over the best server coverage areas of the transmitters included in the traffic map. Either throughput demands per service or the number of active users per service are assigned to the coverage areas of each transmitter. For each transmitter TXi and each service s, •
Sector Traffic Maps (Throughputs)
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Atoll calculates the number of active users of each service s on UL and DL in the coverage area of TXi as follows: N
UL
UL
DL
TP Cell TP Cell DL = ---------------------- and N = ---------------------UL DL TP Average TP Average UL
Where TP Cell is the total uplink throughput demand defined in the map for any service s for the coverage area of the DL
transmitter, TP Cell is the total downlink throughput demand defined in the map for any service s for the coverage UL
DL
area of the transmitter, TP Average is the average uplink requested throughput of the service s, and TP Average is the average downlink requested throughput of the service s. •
Sector Traffic Maps (# Active Users) UL
Atoll directly uses the defined N and N coverage area using the service s.
DL
values, i.e., the number of active users on UL and DL in the transmitter
At any given instant, Atoll calculates the probability for a user being active in the uplink and in the downlink as follows: Users active in the uplink and downlink both are included in the N
UL
UL accurately determine the number of active users in the uplink ( n Active
and N
DL
values. Therefore, it is necessary to UL + DL
DL
), in the downlink ( n Active ), and both ( n Active ).
As for the other types of traffic maps, Atoll considers both active and inactive users. The activity status of each user depends on the activity periods during the call, i.e., the uplink and downlink activity UL
DL
factors defined for the service, f Act and f Act . Calculation of activity probabilities: UL
DL
Probability of being inactive: p Inactive = 1 – f Act 1 – f Act UL
UL
DL
Probability of being active in the uplink: p Active = f Act 1 – f Act DL
DL
UL
Probability of being active in the downlink: p Active = f Act 1 – f Act UL + DL
UL
DL
Probability of being active in the uplink and downlink both: p Active = f Act f Act Calculation of the number of active users trying to access the service: We have: N
UL
UL + DL
UL
= p Active + p Active n and N
DL
UL + DL
DL
= p Active + p Active n
Where, n is the total number of active users in the transmitter coverage area using the service. Calculation of number of users per activity status: UL
UL + DL
DL
UL + DL
N p Active N p Active UL + DL Number of users active in the uplink and downlink both: n Active = Min -------------------------------------- -------------------------------------- or UL UL + DL DL + DL p Active + p Active p Active + p UL Active UL + DL
simply, n Active = Min N
UL
DL
f Act N
DL
UL
f Act UL
Number of users active in the uplink: n Active = N DL
UL
Number of users active in the downlink: n Active = N UL
DL
UL + DL
– n Active DL
UL + DL
– n Active
UL + DL
And, n = n Active + n Active + n Active
Calculation of the number of inactive users attempting to access the service: nv Number of inactive users: n Inactive = ---------------------------- p Inactive 1 – p Inactive
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The activity status distribution between users is an average distribution. In fact, in each simulation, the activity status of each user is randomly drawn. Therefore, if you calculate several simulations at once, average numbers of inactive, active on UL, active on DL and active on UL and DL users correspond to the calculated distribution. But if you check each simulation, the activity status distribution between users can be different in each of them.
11.3.4.2 Simulation Process Each Monte Carlo simulation in Atoll Wi-Fi is a snap-shot of the network with resource allocation carried out over a duration of 1 second. The steps of this algorithm are listed below. The simulation process can be summed up into the following iterative steps. For each simulation, the simulation process, 1. Generates mobiles according to the input traffic data as explained in "User Distribution" on page 793. 2. Sets initial values for the following parameters: TX ic i
•
Cell transmission power ( P DL
) is set to the value defined by the user.
•
Mobile transmission power is set to the maximum mobile power ( P Max ).
•
Cell loads ( TL DL
Mi
TX i ic
TX i ic
, TL UL
TX i ic
, and NR UL
) are set to their current values in the Cells table.
3. Determines the best servers for all the mobiles generated for the simulation as explained in "Best Server Determination" on page 815.
Figure 11.1: Wi-Fi Simulation Algorithm For each iteration k, the simulation process, 4. Determines the mobiles which are within the service areas of their best serving cells as explained in "Service Area Calculation" on page 815. 5. Determines the downlink and uplink C/(I+N) and bearers for each of these mobiles as explained in "C/(I+N) and Bearer Calculation (DL)" on page 807 and "C/(I+N) and Bearer Calculation (UL)" on page 813 respectively.
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6. Determines the channel throughputs at the mobile as explained in "Channel Throughput, Cell Capacity, and Per-user Throughput Calculation" on page 817. 7. Performs radio resource management and scheduling to determine the amount of resources to allocate to each mobile according to the throughput demands of each mobile using the selected scheduler as explained in "Scheduling and Radio Resource Allocation" on page 820. 8. Calculates the user throughputs after allocating resources to each mobile as explained in "User Throughput Calculation" on page 823. 9. Updates the traffic loads, and noise rise values of all the cells according to the resources in use and the total resources as follows: Calculation of Traffic Loads: Atoll calculates the traffic loads for all the cells TXi(ic). TX i ic
TL DL
TX i ic
Mi
RDL and TLUL
=
Mi
RUL
=
Mi
Mi
Calculation of Uplink Noise Rise: For each victim cell TXi(ic), the uplink noise rise is calculated and updated by considering each interfering mobile Mj as explained in "Noise Rise Calculation (UL)" on page 811. 10. Performs the convergence test to see whether the differences between the current and the new loads are within the convergence thresholds. The convergence criteria are evaluated at the end of each iteration k, and can be written as follows: TX i ic
TL DL
=
k
i
TX i ic
TL UL
=
k
k
=
TX ic i
Req
– TL DL
k
– TL UL
TX i ic
TX ic
i Max NR UL All TX ic i
TX ic i
If TL DL
TX i ic
k
TX ic
i Max TL UL All TX ic i
TX i ic
NR UL
TX ic
i Max TL DL All TX ic
, TL UL
k – 1
k – 1
TX i ic
k
– NR UL
k – 1
TX ic i
Req
, and NR UL
Req
are the simulation convergence thresholds defined when creating
the simulation, Atoll stops the simulation in the following cases. Convergence: Simulation has converged between iteration k - 1 and k if: TX i ic
TL DL
TX i ic
k
TL DL
TX i ic
Req
AND TL UL
TX i ic
k
TL UL
TX i ic
Req
AND NR UL
TX i ic
k
NR UL
Req
No convergence: Simulation has not converged even after the last iteration, i.e., k = Max Number of Iterations defined when creating the simulation, if: TX i ic
TL DL
TX i ic
k
TL DL
TX i ic
Req
OR TL UL
TX i ic
k
TL UL
TX i ic
Req
OR NR UL
TX i ic
k
NR UL
Req
11. Repeats the above steps (from step 3.) for the iteration k+1 using the new calculated loads as the current loads. Simulation Results At the end of the simulation process, the main results obtained are: • • •
Downlink traffic load Uplink traffic load Uplink noise rise
These results can be used as input for C/(I+N)-based coverage predictions. In addition to the above parameters, the simulations also list the connection status of each mobile. Mobiles can be rejected due to: • • • •
798
No Coverage: If the mobile does not have any best serving cell (step 3.) or if the mobile is not within the service area of its best server (step 4.). No Service: If the mobile is not able to access a bearer in the direction of its activity (step 5.), i.e., UL, DL, or DL+UL. Scheduler Saturation: If the mobile is not in the list of mobiles selected for scheduling (step 7.) Resource Saturation: If all the cell resources are used up before allocation to the mobile or if, for a user active in uplink, the minimum uplink throughput demand is higher than the uplink allocated bandwidth throughput (step 7.)
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•
Backhaul Saturation: If allocating resources to a mobile makes the effective MAC aggregate site throughputs exceed the maximum backhaul throughputs defined for the site. This condition is only verified if the simulation was created with the Backhaul capacity check box selected (step 7.)
Connected mobiles (step 7.) can be: • • •
Connected UL: If a mobile active in UL is allocated resources in UL. Connected DL: If a mobile active in DL is allocated resources in DL. Connected DL+UL: If a mobile active in DL+UL is allocated resources in DL+UL.
11.4 Calculation Details The following sections describe all the calculation algorithms used in point analysis, calculation of coverage predictions, calculations on subscriber lists, and Monte Carlo simulations.
11.4.1 Co- and Adjacent Channel Overlaps Calculation A Wi-Fi network can consist of cells that use different channel bandwidths. Therefore, the start and end frequencies of all the channels may not exactly coincide. Channel bandwidths of cells can overlap each other with different ratios.
Figure 11.2: Co-Channel and Adjacent Channel Overlaps The following sections describe how the co- and adjacent channel overlaps are calculated between the channels used by any studied cell TXi(ic) and any other cell TXj(jc) of the network. In terms of interference calculation, the studied cell can be considered a victim of interference received from the other cells that might be interfering the studied cell. TX ic i
If the studied cell is assigned a channel number N Channel , it receives co-channel interference on the channel bandwidth of TX i ic
TX i ic
N Channel , and adjacent channel interference on the adjacent channel bandwidths, i.e., corresponding to N Channel – 1 and TX i ic
N Channel + 1 . In order to calculate the co- and adjacent channel overlaps between two channels, it is necessary to calculate the start and end frequencies of both channels (explained in "Conversion From Channel Numbers to Start and End Frequencies" on page 800). Once the start and end frequencies are known for the studied and other cells, the co- and adjacent overlaps and the total overlap ratio are calculated as respectively explained in: • • •
"Co-Channel Overlap Calculation" on page 800. "Adjacent Channel Overlap Calculation" on page 801. "Total Overlap Ratio Calculation" on page 802.
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11.4.1.1 Conversion From Channel Numbers to Start and End Frequencies Input •
TX ic i
TX jc j
F Start – FB and F Start – FB : Start frequency of the frequency band assigned to the cells TXi(ic) and TXj(jc). F Start – FB can represent the uplink or the downlink start frequencies ( F Start – FB – UL or F Start – FB – DL ). First – TX i ic
First – TX j jc
•
N Channel
•
N Channel and N Channel : Channel numbers assigned to cells TXi(ic) and TXj(jc).
TX i ic
and N Channel
: First channel numbers the frequency band assigned to the cells TXi(ic) and TXj(jc).
TX j jc
Atoll considers that the same channel number is assigned to a cell in the downlink and uplink, i.e., the channel number you assign to a cell is considered for uplink and downlink both. TX i ic
TX j jc
•
W Channel and W Channel : Bandwidths of the channels assigned to cells TXi(ic) and TXj(jc).
•
ICS FB
•
TX ic i
TX i ic
CN FB
TX jc j
and ICS FB
: Inter-channel spacing of the frequency bands assigned to cells TXi(ic) and TXj(jc).
TX j jc
and CN FB
: Channel number step of the frequency bands assigned to cells TXi(ic) and TXj(jc).
Calculations Channel numbers are converted into start and end frequencies as follows: For cell TXi(ic): TX i ic
F Start
TX i ic
F End
TX i ic
TX ic
TX i ic
TXi ic – N First – TX i ic Channel Channel N ------------------------------------------------------- TX i ic CN FB
TX ic
i i = F Start – FB + W Channel + ICS FB
TX i ic
= F Start + W Channel
For cell TXj(jc): TX j jc
TX j jc
TX j jc
TX j jc
F End
TX j jc
N TXj jc – N First – TX j jc Channel Channel ------------------------------------------------------- TX jc j CN FB
TX j jc
F Start = F Start – FB + W Channel + ICS FB TX j jc
= F Start – FB + W Channel
Output TX i ic
TX j jc
•
F Start and F Start : Start frequencies for the cells TXi(ic) and TXj(jc).
•
F End
TX i ic
TX j jc
and F End
: End frequencies for the cells TXi(ic) and TXj(jc).
11.4.1.2 Co-Channel Overlap Calculation Input •
TX i ic
F Start
TX j jc
and F Start : Start frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel
Numbers to Start and End Frequencies" on page 800. TX ic i
F End
TX jc j
•
and F End
: End frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel Numbers to Start and End Frequencies" on page 800.
•
W Channel : Bandwidth of the channel assigned to the studied cell TXi(ic).
TX ic i
Calculations Atoll first verifies that co-channel overlap exists between the cells TXi(ic) and TXj(jc).
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Co-channel overlap exists if: TX ic i
TX jc j
TX ic i
F Start F End
AND F End
TX jc j
F Start
Otherwise there is no co-channel overlap. Atoll calculates the bandwidth of the co-channel overlap as follows: TX i ic – TX j jc
W CCO
TX jc
TX ic
TX jc
TX ic
j i j i = Min FEnd F End – Max F Start F Start
The co-channel overlap ratio is given by: TX ic – TX jc i j
TX i ic – TX j jc
W CCO = ---------------------------------TX i ic W Channel
r CCO
Output •
TX i ic – TX j jc
r CCO
: Co-channel overlap ratio between the cells TXi(ic) and TXj(jc).
11.4.1.3 Adjacent Channel Overlap Calculation Input TX i ic
TX j jc
•
F Start
and F Start : Start frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel Numbers to Start and End Frequencies" on page 800.
•
F End
: End frequencies for the cells TXi(ic) and TXj(jc) as calculated in "Conversion From Channel Numbers to Start and End Frequencies" on page 800.
•
W Channel : Bandwidth of the channel assigned to the studied cell TXi(ic).
TX i ic
TX j jc
and F End
TX ic i
Calculations Atoll first verifies that adjacent channel overlaps exist between (the lower-frequency and the higher-frequency adjacent channels of) the cells TXi(ic) and TXj(jc). Adjacent channel overlap exists on the lower-frequency adjacent channel if: TX i ic
TX i ic
TX j jc
F Start – W Channel F End
TX i ic
TX j jc
AND F Start F Start
Adjacent channel overlap exists on the higher-frequency adjacent channel if: TX i ic
F End
TX j jc
F End
TX i ic
AND F End
TX i ic
TX j jc
+ W Channel F Start
Otherwise there is no adjacent channel overlap. Atoll determines the adjacent channel overlap ratio as follows: Bandwidth of the lower-frequency adjacent channel overlap: TX ic – TX jc i j
W ACO
L
TX jc
TX ic
TX jc
TX ic
TX ic
j i j i i = Min F End F Start – Max F Start F Start – W Channel
The lower-frequency adjacent channel overlap ratio is given by: TX ic – TX jc i j r ACO L
TX i ic – TX j jc
W ACO L = ---------------------------------TX i ic W Channel
Bandwidth of the higher-frequency adjacent channel overlap: TX i ic – TX j jc
W ACO
H
TX j jc
TX i ic
= Min F End F End
TX ic
TX jc
TX ic
i j i + W Channel – Max F Start F End
The higher-frequency adjacent channel overlap ratio is given by:
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TX ic – TX jc i j
W ACO H = ---------------------------------TX ic i W Channel
TX ic – TX jc i j r ACO H
The adjacent channel overlap ratio is given by: TX i ic – TX j jc
r ACO
TX i ic – TX j jc
= r ACO
L
TX i ic – TX j jc
+ r ACO
H
Output TX i ic – TX j jc
r ACO
•
: Adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc).
11.4.1.4 Total Overlap Ratio Calculation Input TX i ic – TX j jc
r CCO
•
: Co-channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Co-Channel Overlap
Calculation" on page 800. TX i ic – TX j jc
•
r ACO
: Adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Adjacent Channel
Overlap Calculation" on page 801. TX i ic
•
f ACS – FB : Adjacent channel suppression factor defined for the frequency band of the cell TXi(ic).
•
W Channel and W Channel : Bandwidths of the channels assigned to the cells TXi(ic) and TXj(jc).
TX i ic
TX j jc
Calculations The total overlap ratio is:
TX i ic – TX j jc
rO
=
TX ic
i – f ACS – FB TX ic – TX jc TX ic – TX jc ---------------------------- 10 j i j r i + r ACO 10 CCO
TX i ic
TX j jc
if W Channel W Channel
TX ic
i – f ACS – FB TX i ic TX ic – TX jc TX ic – TX jc ---------------------------- TX i ic TX j jc W Channel 10 i j i j r -------------------- TX jc if W Channel W Channel + r ACO 10 CCO j W Channel TX i ic
W Channel The multiplicative factor --------------------is used to normalise the transmission power of the interfering cell TXj(jc). This means that TX j jc W Channel TX j jc
TX j jc
if the interfering cell transmits at X dBm over a bandwidth of W Channel , and it interferes over a bandwidth less than W Channel , TX ic i
W Channel the interference from this cell should not be considered at X dBm but less than that. The factor --------------------converts X dBm over TX jc j W Channel TX j jc
TX j jc
W Channel to Y dBm (which is less than X dBm) over less than W Channel . Output •
802
TX i ic – TX j jc
rO
: Total co- and adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc).
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11.4.2 Signal Level and Quality Calculations The following sections describe how signal levels, noise and interference, C/N, and C/(I+N) ratios are calculated on the downlink and uplink. • • • • • • • • • •
"Signal Level Calculation (DL)" on page 803. "Noise Calculation (DL)" on page 804. "Interference Calculation (DL)" on page 804. "C/N Calculation (DL)" on page 806. "C/(I+N) and Bearer Calculation (DL)" on page 807. "Signal Level Calculation (UL)" on page 809. "Noise Calculation (UL)" on page 810. "Interference Calculation (UL)" on page 810. "C/N Calculation (UL)" on page 812. "C/(I+N) and Bearer Calculation (UL)" on page 813.
11.4.2.1 Signal Level Calculation (DL) Input TX ic i
P DL
• •
G
•
L
TX i
TX i
: Transmission power of the cell TXi(ic).
: Transmitter antenna gain for the antenna used by the transmitter TXi. ( G : Total transmitter losses for the transmitter TXi ( L
TX i
TX i
TX i
= G Ant ).
= L Total – DL ).
TX i
•
L Path : Path loss ( L Path = L Model + L Ant ).
•
L Model : Loss on the transmitter-receiver path (path loss) calculated using a propagation model.
•
L Ant : Antenna attenuation (from antenna patterns) calculated for the antenna used by the transmitter TXi.
•
M Shadowing – Model : Shadowing margin based on the model standard deviation.
TX
i
In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. •
L Indoor : Indoor losses taken into account when the option "Indoor coverage" is selected.
•
L
•
G
Mi Mi
: Receiver terminal losses for the pixel, subscriber, or mobile Mi. : Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi.
Mi
L Ant : Receiver terminal’s antenna attenuation calculated for the pixel, subscriber, or mobile Mi.
•
Mi
For calculating the useful signal level from the best serving cell, L Ant is determined in the direction (H,V) = (0,0) from Mi
the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, L Ant is determined in the direction of the interfering cell from the antenna patterns of the antenna used by Mi, while the antenna is pointed towards Mi’s best serving cell. Mi
•
L Body : Body loss defined for the service used by the pixel, subscriber, or mobile Mi.
Calculations The received signal levels (dBm) from any cell TXi(ic) are calculated for a pixel, subscriber, or mobile Mi as follows: TX i ic
C DL
= EIRP
TX i ic
– L Path – M Shadowing – Model – L Indoor + G
Mi
–L
Mi
Mi
Mi
– L Ant – L Body
Where EIRP is the effective isotropic radiated power of the cell calculated as follows: EIRP
TX i ic
TX i ic
= P DL
+G
TX i
–L
TX i
803
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©Forsk 2015
If you wish to exclude the energy corresponding to the cyclic prefix (guard interval) in the total symbol duration from the useful signal level, you must add the following lines in the Atoll.ini file: [WiMAX] ExcludeCPFromUsefulPower = 1 TX i ic
When this option is active, the cyclic prefix energy is excluded from C DL TX i ic
words, the factor 10 Log 1 – r CP
. In other
TX ic
is added to C i . DL Independant of the option, interference levels are calculated for the total symbol durations, i.e., the energy of the useful symbol duration and the cyclic prefix energy. Output •
TX i ic
C DL
: Received signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
11.4.2.2 Noise Calculation (DL) For determining the C/N and C/(I+N), Atoll calculates the downlink noise over the channel bandwidth used by the cell. The used bandwidth depends on the number of used subcarriers. The downlink noise comprises thermal noise and the noise figure of the equipment. The thermal noise density depends on the temperature, i.e., it remains constant for a given temperature. However, the value of the thermal noise varies with the used bandwidth. Input • •
K: Boltzmann’s constant. T: Temperature in Kelvin.
•
N SCa – Used : Number of used subcarriers defined for the frame configuration of a cell TXi(ic).
•
N SCa – Total : Total number of subcarriers defined for the frame configuration of a cell TXi(ic).
•
nf
TX i ic TX ic i Mi
: Noise figure of the terminal used for calculations by the pixel, subscriber, or mobile Mi.
Calculations The power spectral density of thermal noise is calculated as follows: n 0 = 10 Log K T 1000 = – 174 dBm/Hz The thermal noise for a cell is calculated as: N TXi ic TX i ic SCa – Used n 0 – DL = n 0 + 10 Log ------------------------TX i ic N SCa – Total The downlink noise is the sum of the thermal noise and the noise figure of the terminal used for the calculations by the pixel, subscriber, or mobile Mi. TX ic i
n DL
TX ic i
= n 0 – DL + nf
M
i
Output •
TX i ic
n DL
: Downlink noise for the cell TXi(ic).
11.4.2.3 Interference Calculation (DL) The interference received by any pixel, subscriber, or mobile, served by a cell TXi(ic) from other cells TXj(jc) can be defined as the signal levels received from interfering cells TXj(jc) depending on the overlap that exists between the channels used by the cells TXi(ic) and TXj(jc), and on the traffic loads of the interfering cells TXj(jc).
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Input TX jc j
•
C DL
: Received signal level from the cell TXi(ic) as explained in "Signal Level Calculation (DL)" on page 803.
•
M Shadowing – C I : Shadowing margin based on the C/I standard deviation. In Monte Carlo simulations, the received signal levels from interferers already include M Shadowing – Model , as explained in "Signal Level Calculation (DL)" on page 803. In coverage predictions, the ratio M Shadowing – Model – M Shadowing – C I is applied to the interfering signals (for more information, see "Shadow Fading Model" on page 90). As the received signal levels from interferers already include M Shadowing – Model , M Shadowing – C I is added to the signal levels from interferers in order to achieve the ratio M Shadowing – Model – M Shadowing – C I : TX j jc
C DL
TX j jc
= C DL
+ M Shadowing – C I
In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. •
TX j jc
TL DL
: Downlink traffic load of the interfering cell TXj(jc).
Traffic loads can either be calculated using Monte Carlo simulations, or entered manually for each cell. Calculation of traffic loads is explained in "Simulation Process" on page 797. •
TX i ic – TX j jc
rO
: Total channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Co- and Adjacent
Channel Overlaps Calculation" on page 799. Calculations Interference (dBm) from any cell TXj(jc) is calculated for a pixel, subscriber, or mobile Mi as follows: TX j jc
I DL
TX j jc
= C DL
TX i ic – TX j jc
+ fO
TX j jc
Inter – Tech
+ f TL – DL + I DL
If you wish to exclude the energy corresponding to the cyclic prefix (guard interval) in the total symbol duration from the useful signal level, you must add the following lines in the Atoll.ini file: [WiMAX] ExcludeCPFromUsefulPower = 1 TX i ic
When this option is active, the cyclic prefix energy is excluded from C DL TX i ic
. In other
TX i ic
words, the factor 10 Log 1 – r CP is added to C DL . Independent of the option, interference levels are calculated for the total symbol durations, i.e., the energy of the useful symbol duration and the cyclic prefix energy. Calculations for the interference reduction factors due to channel overlapping and traffic load are explained below: Interference reduction due to the co- and adjacent channel overlap between the studied and the interfering cells: Interference reduction due to the co- and adjacent channel overlap between the cells TXi(ic) and TXj(jc) is calculated as follows: TX i ic – TX j jc
fO
TX i ic – TX j jc
= 10 Log r O
Interference reduction due to interfering cell’s traffic load: The interference reduction factor due to the interfering cell’s traffic load is calculated as follows: TX j jc
TX j jc
f TL – DL = 10 Log TL DL Inter – Tech
I DL
is the inter-technology downlink interference from transmitters of an external network (linked document of any
technology) calculated as follows:
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 11: Wi-Fi Networks
Inter – Tech
I DL
=
©Forsk 2015
TX – External
EIRP DL
– L Path – L Indoor + G
M
i
–L
M
i
M
i
M
i
Inter – Tech
– L Ant – L Body – f IRF
All External TXs TX – External
Where EIRP DL
is the downlink EIRP of the external transmitter, L Path is the path loss from the external transmitters
to the pixel, subscriber, or mobile location, L Indoor is the indoor losses taken into account when the option "Indoor coverage" is selected, L
Mi
is the receiver terminal losses for the pixel, subscriber, or mobile Mi, G
Mi
is the receiver terminal’s antenna
Mi
gain for the pixel, subscriber, or mobile Mi, L Ant is the receiver terminal’s antenna attenuation calculated for the pixel, M
i
subscriber, or mobile Mi, and L Body is the body loss defined for the service used by the pixel, subscriber, or mobile Mi. Calculation of the Downlink Inter-technology Interference The downlink inter-technology interference is calculated as follows: Inter – Tech I DL
TX k P DL – Rec --------------------------------------- = F TX i ic TX k TX k ICP DL
TX k
Here P DL – Rec is the received downlink power from an interfering cell TXk belonging to another technology, and F TX i ic TX k
ICP DL
is the inter-technology downlink channel protection ratio for a frequency offset F between the interfered
and interfering frequency channels of TXi(ic) and TXk. TX k
P DL – Rec is calculated based on the EIRP from GSM cells, total power from UMTS, CDMA2000, and TD-SCDMA cells, maximum power from LTE cells, preamble power from WiMAX cells, and downlink cell power from Wi-Fi cells. Output TX j jc
•
I DL
•
I DL
: Downlink interference received at the pixel, subscriber, or mobile Mi from any interfering cell TXj(jc).
Inter – Tech
: Downlink inter-technology interference.
11.4.2.4 C/N Calculation (DL) Input •
TX i ic
C DL
: Received signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Signal Level
Calculation (DL)" on page 803. TX i ic
•
n DL
: Downlink noise for the cell TXi(ic) as calculated in "Noise Calculation (DL)" on page 804.
•
T AMS : AMS threshold defined for the cell TXi(ic).
•
T B : Bearer selection thresholds of the bearers defined in the Wi-Fi equipment used by Mi’s terminal.
•
B DL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
TX i ic Mi
Mi
or mobile Mi. •
Mi
B DL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber, or mobile Mi. TX ic i
•
N Ant – TX : Number of MIMO transmission (downlink) antennas defined for the cell TXi(ic).
•
N Ant – RX : Number of MIMO reception (downlink) antennas defined for the terminal used by the pixel, subscriber, or
Mi
mobile Mi. • •
806
Mobility M i : Mobility used for the calculations. M
i BLER BDL : Downlink block error rate read from the graphs available in the Wi-Fi equipment assigned to the terminal used by the pixel, subscriber, or mobile Mi.
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 11: Wi-Fi Networks
AT330_TRR_E1
Calculations The C/N for a cell TXi(ic) are calculated as follows for any pixel, subscriber, or mobile Mi: TX ic i
CNR DL
TX ic i
= C DL
TX ic i
– n DL
Bearer Determination: The bearers available for selection in the pixel, subscriber, or mobile Mi’s Wi-Fi equipment are the ones: •
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
•
Whose selection thresholds are less than the C/N at Mi: T B CNR DL
TX i ic
Mi
Mi
If the cell’s frame configuration supports AMS, the STTD/MRC or SU-MIMO diversity gain, G Div – DL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the Wi-Fi equipment TX ic
M
M
i i i assigned to the pixel, subscriber, or mobile Mi for N Ant – TX , N Ant – RX , Mobility M i , BLER BDL . DL
The additional diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the Wi-Fi equipment for which the following is true: Mi
Mi
TX i ic
DL
T B – G Div – DL – G Div CNR DL
The bearer selected for data transfer is the one with the highest index. MIMO – STTD/MRC and SU-MIMO Diversity Gains: Once the bearer is known, the C/N calculated above become: TX ic i
TX ic i
= CNR DL
CNR DL
M
i
DL
+ G Div – DL + G Div
Mi
Where G Div – DL is the STTD/MRC or SU-MIMO diversity gain corresponding to the selected bearer. Output •
TX i ic
CNR DL
: C/N from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
11.4.2.5 C/(I+N) and Bearer Calculation (DL) The carrier signal to interference and noise ratio is calculated in three steps. First Atoll calculates the received signal level from the studied cell (as explained in "Signal Level Calculation (DL)" on page 803) at the pixel, subscriber, or mobile under study. Next, Atoll calculates the interference received at the same studied pixel, subscriber, or mobile from all the interfering cells (as explained in "Interference Calculation (DL)" on page 804). Interference from each cell is weighted according to the co- and adjacent channel overlap between the studied and the interfering cells, and the traffic loads of the interfering cells. Finally, Atoll takes the ratio of the signal level and the sum of the total interference from other cells and the downlink noise (as calculated in "Noise Calculation (DL)" on page 804). The receiver terminal is always considered to be oriented towards its best server, except when the "Lock Status" is set to "Server+Orientation" for a subscriber in a subscriber list and its azimuth and tilt manually edited. In the case of NLOS between the receiver and the best server, Atoll does not try to find the direction of the strongest signal, the receiver is oriented towards the best server just as in the case of LOS. Input •
TX i ic
C DL
: Received signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Signal Level
Calculation (DL)" on page 803. •
TX i ic
n DL
: Downlink noise for the cell TXi(ic) as calculated in "Noise Calculation (DL)" on page 804.
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 11: Wi-Fi Networks TX jc j
•
I DL
©Forsk 2015
: Interference from any cell TXj(jc) calculated for a pixel, subscriber, or mobile Mi covered by a cell TXi(ic) as
explained in "Interference Calculation (DL)" on page 804. Inter – Tech
•
NRDL
•
TX ic i T AMS
•
T B : Bearer selection thresholds of the bearers defined in the Wi-Fi equipment used by Mi’s terminal.
•
B DL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
: Inter-technology downlink noise rise.
: AMS threshold defined for the cell TXi(ic).
Mi
Mi
or mobile Mi. M
i
B DL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber,
•
or mobile Mi. TX i ic
•
N Ant – TX : Number of MIMO transmission (downlink) antennas defined for the cell TXi(ic).
•
N Ant – RX : Number of MIMO reception (downlink) antennas defined for the terminal used by the pixel, subscriber, or
M
i
mobile Mi. •
Mobility M i : Mobility used for the calculations.
•
i BLER BDL : Downlink block error rate read from the graphs available in the Wi-Fi equipment assigned to the terminal
M
used by the pixel, subscriber, or mobile Mi. Inter – Tech
•
I DL
: Downlink inter-technology interference as calculated in "Interference Calculation (DL)" on page 804.
Calculations The downlink C/(I+N) for a cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi:
TX i ic
CINR DL
TX i ic
= C DL
TXj jc TX i ic n DL IDL Inter – Tech Inter – Tech ------------------- --------------------- +I + + NR DL 10 – 10 Log 10 10 DL 10 All TXj jc
The Total Noise (I+N) for a cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX ic
TX ic i
I + N DL
i TX j jc n DL I DL --------------------- Inter – Tech Inter – Tech 10 -----------------= 10 Log + 10 + NR DL 10 + I DL 10 All TX j jc
Bearer Determination: The bearers available for selection in the pixel, subscriber, or mobile Mi’s Wi-Fi equipment are the ones: •
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
•
Whose selection thresholds are less than the downlink C/(I+N) at Mi: T B CINR DL
Mi
TX i ic
M
i
If the cell’s frame configuration supports AMS, the STTD/MRC or SU-MIMO diversity gain, G Div – DL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the Wi-Fi equipment TX ic
M
M
i i i assigned to the pixel, subscriber, or mobile Mi for N Ant – TX , N Ant – RX , Mobility M i , BLER B DL . DL
The additional diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the Wi-Fi equipment for which the following is true:
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AT330_TRR_E1 M
M
i
i
TX ic i
DL
T B – G Div – DL – G Div CINR DL
The bearer selected for data transfer is the one with the highest index. MIMO – STTD/MRC and SU-MIMO Diversity Gains: Once the bearer is known, the C/(I+N) calculated above become: TX i ic
CINR DL
TX i ic
= CINR DL
Mi
DL
+ G Div – DL + G Div
Mi
Where G Div – DL is the STTD/MRC or SU-MIMO diversity gain corresponding to the selected bearer. Output TX i ic
•
CINR DL
•
I + N DL
•
: Downlink C/(I+N) from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.
TX i ic
M
: Total noise from the interfering cells TXj(jc) at the pixel, subscriber, or mobile Mi covered by a cell TXi(ic).
i
B DL : Bearer assigned to the pixel, subscriber, or mobile Mi in the downlink.
11.4.2.6 Signal Level Calculation (UL) Input Mi
•
P Max : Maximum transmission power of the terminal used by the pixel, subscriber, or mobile Mi without power control.
•
P Eff : Effective transmission power of the terminal used by the pixel, subscriber, or mobile Mi after power control as
Mi
calculated in "C/(I+N) and Bearer Calculation (UL)" on page 813. TX i
TX i
= G Ant ).
G
•
L
•
L Path : Path loss ( L Path = L Model + L Ant ).
•
L Model : Loss on the transmitter-receiver path (path loss) calculated using a propagation model.
•
L Ant : Antenna attenuation (from antenna patterns) calculated for the antenna used by the transmitter TXi.
•
M Shadowing – Model : Shadowing margin based on the model standard deviation.
TX i
: Transmitter antenna gain for the antenna used by the transmitter TXi ( G
TX i
•
: Total transmitter losses for the transmitter TXi ( L
TX i
= L Total – UL ).
TX i
TX i
In coverage predictions, shadowing margins are taken into account when the option "Shadowing taken into account" is selected. •
L Indoor : Indoor losses taken into account when the option "Indoor coverage" is selected.
•
L
• •
M
G
i
M
M
: Receiver terminal losses for the pixel, subscriber, or mobile Mi. i
: Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi.
i
L Ant : Receiver terminal’s antenna attenuation calculated for the pixel, subscriber, or mobile Mi. Mi
For calculating the useful signal level from the best serving cell, L Ant is determined in the direction (H,V) = (0,0) from M
i
the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, L Ant is determined in the direction of the interfering cell from the antenna patterns of the antenna used by Mi, while the antenna is pointed towards Mi’s best serving cell. •
Mi
L Body : Body loss defined for the service used by the pixel, subscriber, or mobile Mi.
Calculations The received traffic signal level (dBm) from a pixel, subscriber, or mobile Mi at its serving cell TXi(ic) is calculated as follows:
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Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 11: Wi-Fi Networks M
M
i
i
C UL = EIRP UL – L Path – M Shadowing – Model – L Indoor + G
©Forsk 2015 TX
i
–L
TX
i
M
i
M
i
– L Ant – L Body
Where EIRP is the effective isotropic radiated power of the terminal calculated as follows: M
i
EIRP UL = P With P
Mi
M
i
+G
M
i
–L
M
i
Mi
= P Max without power control at the start of the calculations, and is the P
Mi
Mi
= P Eff after power control.
Output •
M
i
C UL : Received uplink signal level from the pixel, subscriber, or mobile Mi at a cell TXi(ic).
11.4.2.7 Noise Calculation (UL) For determining the uplink C/N and C/(I+N), Atoll calculates the uplink noise over the channel bandwidth used by the cell. The used bandwidth depends on the number of used subcarriers. The uplink noise comprises thermal noise and the noise figure of the equipment. The thermal noise density depends on the temperature, i.e., it remains constant for a given temperature. However, the value of the thermal noise varies with the used bandwidth. Input • •
K: Boltzmann’s constant. T: Temperature in Kelvin.
•
N SCa – Used : Number of used subcarriers defined for the frame configuration of a cell TXi(ic).
•
N SCa – Total : Total number of subcarriers defined for the frame configuration of a cell TXi(ic).
•
nf
TX i ic TX i ic
TX i ic
: Noise figure of the cell TXi(ic).
Calculations The power spectral density of thermal noise is calculated as follows: n 0 = 10 Log K T 1000 = – 174 dBm/Hz The thermal noise for a cell is calculated as: N TXi ic TX i ic SCa – Used n 0 – UL = n 0 + 10 Log ------------------------ TXi ic N SCa – Total The uplink noise is the sum of the thermal noise and the noise figure of the cell TXi(ic). TX i ic
n UL
TX i ic
= n 0 – UL + nf
TX i ic
Output •
TX ic i
n UL
: Uplink noise for the cell TXi(ic).
11.4.2.8 Interference Calculation (UL) The uplink interference is only calculated during Monte Carlo simulations. In coverage predictions, the uplink noise rise values already available in simulation results or in the Cells table are used. The interference received by a cell TXi(ic) from an interfering mobile covered by a cell TXj(jc) can be defined as the uplink signal level received from interfering mobiles Mj depending on the overlap that exists between the channels used by the cells TXi(ic) and TXj(jc), on the traffic loads of the interfering mobile Mj. The calculation of uplink interference can be divided into two parts: • •
810
Calculation of the uplink interference from each individual interfering mobile as explained in "Interference Signal Levels Calculation (UL)" on page 811. Calculation of the uplink noise rise which represents the total uplink interference from all the interfering mobiles as explained in "Noise Rise Calculation (UL)" on page 811.
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 11: Wi-Fi Networks
AT330_TRR_E1
11.4.2.8.1
Interference Signal Levels Calculation (UL) Input •
M
j
C UL : Uplink signal level received at a cell TXi(ic) from an interfering mobile Mj covered by a cell TXj(jc) as calculated in "Signal Level Calculation (UL)" on page 809.
•
TX i ic – TX j jc
rO
: Total channel overlap ratio between the cells TXi(ic) and TXj(jc) as calculated in "Co- and Adjacent
Channel Overlaps Calculation" on page 799. •
Mj
TL UL : Uplink traffic load of the interfering mobile Mj. Traffic loads are calculated during Monte Carlo simulations as explained in "Scheduling and Radio Resource Allocation" on page 820.
Calculations The uplink interference received at a cell TXi(ic) from an interfering mobile Mj covered by a cell TXj(jc) is calculated as follows: Mj
TX i ic – TX j jc
Mj
I UL = C UL + f O
Mj
+ f TL – UL
Calculations for the interference reduction factors due to channel overlapping and uplink traffic load are explained below: Interference reduction due to the co- and adjacent channel overlap between the studied and the interfering cells: Interference reduction due to the co- and adjacent channel overlap between the cells TXi(ic) and TXj(jc) is calculated as follows: TX i ic – TX j jc
fO
TX i ic – TX j jc
= 10 Log r O
Interference reduction due to interfering mobile’s traffic load: The interference reduction factor due to the interfering mobile’s uplink traffic load is calculated as follows: M
M
j j f TL – UL = 10 Log TL UL
Output •
11.4.2.8.2
Mj
I UL : Uplink interference signal level received at a cell TXi(ic) from an interfering mobile Mj covered by a cell TXj(jc).
Noise Rise Calculation (UL) The uplink noise rise is defined as the ratio of the total uplink interference received by any cell TXi(ic) from interfering mobiles Mj present in the coverage areas of other cells TXj(jc) to the uplink noise of the cell TXi(ic). In other words, it is the ratio (I+N)/N. Input •
M
j
I UL : Uplink interference signal levels received at a cell TXi(ic) from interfering mobiles Mj covered by other cells TXj(jc) as calculated in "Interference Signal Levels Calculation (UL)" on page 811. TX i ic
•
n UL
•
NR UL
: Uplink noise for the cell TXi(ic) as calculated in "Noise Calculation (UL)" on page 810.
Inter – Tech
: Inter-technology uplink noise rise.
Calculations The uplink noise rise and total noise (I+N) for the cell TXi(ic) are calculated as follows:
TX i ic
NRUL
TX i ic Mj n UL - I UL -------------------TX i ic Inter – Tech 10 -------- = 10 Log – n UL 10 + 10 + NRUL 10 All M j All TX jc
j
For any pixel, subscriber, or mobile Mi in the interfered cell TXi(ic), Atoll calculates the uplink total noise (I+N) as follows:
811
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 11: Wi-Fi Networks TX ic i
I + N UL
TX ic i
= NR UL
©Forsk 2015
TX ic i
+ n UL
Output TX ic i
•
NRUL
•
I + N UL
: Uplink noise rise for the cell TXi(ic).
TX i ic
: Total noise for a cell TXi(ic) calculated for any pixel, subscriber, or mobile Mi.
11.4.2.9 C/N Calculation (UL) Input Mi
C UL : Received uplink signal level from the pixel, subscriber, or mobile Mi at its serving cell TXi(ic) as calculated in
•
"Signal Level Calculation (UL)" on page 809. TX i ic
•
n UL
: Uplink noise for the cell TXi(ic) as calculated in "Noise Calculation (UL)" on page 810.
TX i ic
•
T AMS : AMS threshold defined for the cell TXi(ic).
•
P Max : Maximum transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
P Min : Minimum transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
M PC : Power control margin defined in the global network settings.
•
T B : Bearer selection thresholds of the bearers defined in the Wi-Fi equipment used bythe cell TXi(ic).
•
B UL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
Mi Mi
Mi
Mi
or mobile Mi. Mi
B UL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber,
•
or mobile Mi. Mi
N Ant – TX : Number of MIMO transmission (uplink) antennas defined for the terminal used by the pixel, subscriber, or
•
mobile Mi. TX i ic
•
N Ant – RX : Number of MIMO reception (uplink) antennas defined for the cell TXi(ic).
•
Mobility M i : Mobility used for the calculations.
•
i BLER BUL : Uplink block error rate read from the graphs available in the Wi-Fi equipment assigned to the cell TXi(ic).
M
Calculations The uplink C/N from a pixel, subscriber, or mobile Mi at its serving cell TXi(ic) is calculated as follows: M
M
i
i
TX ic i
CNR UL = C UL – n UL
Bearer Determination: The bearers available for selection in the cell TXi(ic)’s Wi-Fi equipment are the ones:
812
•
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
•
Whose selection thresholds are less than the uplink C/N at Mi: T B CNR UL
Mi
Mi
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 11: Wi-Fi Networks
AT330_TRR_E1
TX ic i
If the cell’s frame configuration supports AMS, the STTD/MRC or SU-MIMO diversity gain, G Div – UL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the Wi-Fi equipment TX ic
M
M
i i i assigned to the cell TXi(ic) for N Ant – RX , N Ant – TX , Mobility M i , BLER B UL . UL
The additional diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the Wi-Fi equipment for which the following is true: M
TX ic i
i
M
UL
i
T B – G Div – UL – G Div CNR UL The bearer selected for data transfer is the one with the highest index. MIMO – STTD/MRC and SU-MIMO Diversity Gains: Once the bearer is known, the C/N calculated above become: Mi
Mi
TX i ic
UL
CNR UL = CNR UL + G Div – UL + G Div TX i ic
Where G Div – UL is the STTD/MRC or SU-MIMO diversity gain corresponding to the selected bearer. Uplink Power Control: The pixel, subscriber, or mobile Mi reduces its transmission power so that the uplink C/N from it at its cell is just enough to get the selected bearer. If with P
Mi
Mi
Mi
= P Max AND CNR UL T
TX i ic Mi
+ M PC , where T
B UL
TX i ic Mi B UL
is the bearer selection threshold, from the Wi-Fi
equipment assigned to the cell TXi(ic), for the bearer selected for the pixel, subscriber, or mobile Mi. The transmission power of Mi is reduced to determine the effective transmission power from the pixel, subscriber, or mobile Mi as follows: Mi M i TX i ic Mi Mi P Eff = Max P Max – CNR UL – T M + M PC P Min B i UL
Mi
Mi
CNR UL is calculated again using P Eff . Output •
Mi
CNR UL : Uplink C/N from a pixel, subscriber, or mobile Mi at it serving cell TXi(ic).
11.4.2.10 C/(I+N) and Bearer Calculation (UL) The carrier signal to interference and noise ratio is calculated in three steps. First, Atoll calculates the received signal level from each pixel, subscriber, or mobile at its serving cell using the effective power of the terminal used by the pixel, subscriber, or mobile as explained in "Signal Level Calculation (UL)" on page 809. Next, Atoll calculates the uplink carrier to noise ratio as explained in "C/N Calculation (UL)" on page 812. Finally, determines the uplink C/(I+N) by dividing the previously calculated uplink C/N by the uplink noise rise value of the cell as calculated in "Noise Rise Calculation (UL)" on page 811. The uplink noise rise can be set by the user manually for each cell or calculated using Monte Carlo simulations. The receiver terminal is always considered to be oriented towards its best server, except when the "Lock Status" is set to "Server+Orientation" for a subscriber in a subscriber list and its azimuth and tilt manually edited. In the case of NLOS between the receiver and the best server, Atoll does not try to find the direction of the strongest signal, the receiver is oriented towards the best server just as in the case of LOS. Input •
Mi
CNR UL : Uplink C/N from a pixel, subscriber, or mobile Mi at it serving cell TXi(ic) as calculated in "C/N Calculation (UL)" on page 812.
•
TX i ic
NR UL
: Uplink noise rise for the cell TXi(ic) as calculated in "Noise Rise Calculation (UL)" on page 811.
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TX ic i
•
T AMS : AMS threshold defined for the cell TXi(ic).
•
P Max : Maximum transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
P Min : Minimum transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
M PC : Power control margin defined in the global network settings.
•
T B : Bearer selection thresholds of the bearers defined in the Wi-Fi equipment used bythe cell TXi(ic).
•
B UL – Highest Service : Highest downlink bearer defined in the properties of the service used by the pixel, subscriber,
M M
i i
Mi
Mi
or mobile Mi. Mi
B UL – Lowest Service : Lowest downlink bearer defined in the properties of the service used by the pixel, subscriber,
•
or mobile Mi. Mi
N Ant – TX : Number of MIMO transmission (uplink) antennas defined for the terminal used by the pixel, subscriber, or
•
mobile Mi. TX i ic
•
N Ant – RX : Number of MIMO reception (uplink) antennas defined for the cell TXi(ic).
•
Mobility M i : Mobility used for the calculations.
•
i BLER BUL : Uplink block error rate read from the graphs available in the Wi-Fi equipment assigned to the cell TXi(ic).
M
Calculations The uplink C/(I+N) for any pixel, subscriber, or mobile Mi at a cell TXi(ic) is calculated as follows: Mi
TX i ic
Mi
CINR UL = CNR UL – NR UL
Bearer Determination: The bearers available for selection in the cell TXi(ic)’s Wi-Fi equipment are the ones: •
Which are common between Mi’s and TXi(ic)’s equipment (bearer indexes for which selection thresholds are defined in both equipment), if the corresponding option has been set in the Atoll.ini file. For more information, see the Administrator Manual.
•
Whose indexes are within the range defined by the lowest and the highest bearer indexes defined for the service being accessed by Mi.
•
Whose selection thresholds are less than the uplink C/(I+N) at Mi: T B CINR UL
M
M
i
i
TX i ic
If the cell’s frame configuration supports AMS, the STTD/MRC or SU-MIMO diversity gain, G Div – UL , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the Wi-Fi equipment M
TX ic
M
i i i assigned to the cell TXi(ic) for N Ant – RX , N Ant – TX , Mobility M i , BLER BUL . UL
The additional diversity gain defined for the clutter class of the pixel, subscriber, or mobile Mi G Div is also applied. Therefore, the bearers available for selection are all the bearers defined in the Wi-Fi equipment for which the following is true: Mi
TX i ic
UL
Mi
T B – G Div – UL – G Div CINR UL The bearer selected for data transfer is the one with the highest index. MIMO – STTD/MRC and SU-MIMO Diversity Gains: Once the bearer is known, the C/(I+N) calculated above become: Mi
Mi
TX i ic
UL
CINR UL = CINR UL + G Div – UL + G Div TX i ic
Where G Div – UL is the STTD/MRC or SU-MIMO diversity gain corresponding to the selected bearer. Uplink Power Control:
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The pixel, subscriber, or mobile Mi reduces its transmission power so that the uplink C/(I+N) from it at its cell is just enough to get the selected bearer. If with P
M
i
M
i
M
i
= P Max AND CINR UL T
TX ic i M i B UL
+ M PC , where T
TX ic i M i B UL
is the bearer selection threshold, from the Wi-Fi
equipment assigned to the cell TXi(ic), for the bearer selected for the pixel, subscriber, or mobile Mi. The transmission power of Mi is reduced to determine the effective transmission power from the pixel, subscriber, or mobile Mi as follows: Mi M i TX i ic Mi Mi P Eff = Max P Max – CINR UL – T M + M PC P Min i B UL
Mi
Mi
CINR UL is calculated again using P Eff . Output Mi
•
CINR UL : Uplink C/(I+N) from a pixel, subscriber, or mobile Mi at it serving cell TXi(ic).
•
P Eff : Effective transmission power of the terminal used by the pixel, subscriber, or mobile Mi.
•
B UL : Bearer assigned to the pixel, subscriber, or mobile Mi in the uplink.
Mi M
i
11.4.3 Best Server Determination In Wi-Fi, best server refers to a cell ("serving transmitter"-"reference cell" pair) from which a pixel, subscriber, or mobile Mi gets the highest signal level. This calculation also determines whether the pixel, subscriber, or mobile Mi is within the coverage area of any transmitter or not. Input •
TX i ic
C DL
: Downlink signal level received from any cell TXi(ic) at a pixel, subscriber, or mobile Mi as calculated in "Signal
Level Calculation (DL)" on page 803 using the terminal and service parameters ( L
Mi
,G
Mi
Mi
Mi
, L Ant , and L Body ) of Mi.
Calculations The best server of any pixel, subscriber, or mobile Mi, BS M , is the cell from which the received downlink signal level is the i
highest among all the cells. The best server is determined as follows: BSM = TX i ic i
TX ic TX i ic i = Best C DL C All TX i ic DL
Here ic is the cell of the transmitter TXi with the highest power. However, if more than one cell of the same transmitter covers the pixel, subscriber, or mobile, the final reference cell ic might be different from the initial cell ic (the one with the highest power). In coverage prediction calculations and in calculations on subsriber lists, the cell of the highest priority layer is selected as the serving (reference) cell. In Monte Carlo simulations, a random cell is selected as the serving (reference) cell. Output •
BS M : Best serving cell of the pixel, subscriber, or mobile Mi. i
11.4.4 Service Area Calculation In Wi-Fi, a pixel, subscriber, or mobile Mi can be covered by a cell (as calculated in "Best Server Determination" on page 815) but can be outside the service area. A pixel, subscriber, or mobile Mi is said to be within the service area of its best serving cell TXi(ic) if the downlink C/N from the cell at the pixel, subscriber, or mobile is greater than or equal to the minimum C/N threshold defined for the cell.
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Input •
TX ic i
CNR DL
: Downlink C/N from the cell TXi(ic) at a pixel, subscriber, or mobile Mi as calculated in "C/N Calculation (DL)"
on page 806. •
TX ic i
T Min
: Min C/N threshold defined for the cell TXi(ic).
Calculations A pixel, subscriber, or mobile Mi is within the service area of its best serving cell TXi(ic) if: TX ic i
CNR DL
TX ic i
T Min
Output • •
True: If the calculation criterion is satisfied. False: Otherwise.
11.4.5 Throughput Calculation Throughputs are calculated in two steps. • •
Calculation of uplink and downlink total resources in a cell as explained in "Calculation of Total Cell Resources" on page 816. Calculation of throughputs as explained in "Channel Throughput, Cell Capacity, and Per-user Throughput Calculation" on page 817.
11.4.5.1 Calculation of Total Cell Resources The total amount of resources in a cell is the number of modulation symbols that can be used for data transfer per second. Input TX ic i
•
W Channel : Channel bandwidth of the cell TXi(ic).
•
N SCa – Total : Total number of subcarriers defined for the frame configuration of a cell TXi(ic).
•
N SCa – Data : Number of data subcarriers defined for the frame configuration of a cell TXi(ic).
•
: Cyclic prefix ratio defined for the cell’s frame configuration of TXi(ic) or, otherwise, in the global network settings.
TX i ic TX i ic
TX i ic
r CP
Calculations Atoll determines the inter-subcarrier spacing. F
TX i ic
TX i ic
6
W Channel 10 = ----------------------------------TX i ic N SCa – Total
Atoll calculates the useful symbol duration. TX i ic 1 D Sym – Useful = ------------------TX i ic F
And, the duration of the cyclic prefix (guard interval). TX i ic
D CP
TX i ic
r CP = -------------F
Adding the cyclic prefix ratio to the useful symbol duration, Atoll determines the total symbol duration. TX i ic
TX i ic
TX i ic
D Symbol = D Sym – Useful + D CP
The total number of modulation symbols in the downlink and uplink are:
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AT330_TRR_E1 TX ic i
R DL
TX ic i
= R UL
TX ic 1 - N SCai – Data = Floor ----------------TX ic D i Symbol
Output •
TX i ic
TX i ic
R DL
and R UL
: Amount of downlink and uplink resources in the cell TXi(ic).
11.4.5.2 Channel Throughput, Cell Capacity, and Per-user Throughput Calculation Channel throughputs are calculated for the entire channel resources allocated to the pixel, subscriber, or mobile Mi. Cell capacities are similar to channel throughputs but upper-bound by the maximum downlink and uplink traffic loads. Per-user throughputs are calculated by dividing the cell capacities by the average number of connects users, downlink or uplink, defined for the cell. Input TX i ic
•
TL DL – Max : Maximum downlink traffic load for the cell TXi(ic).
•
TL UL – Max : Maximum uplink traffic load for the cell TXi(ic).
•
R DL
TX ic i
TX i ic
: Amount of downlink resources in the cell TXi(ic) as calculated in "Calculation of Total Cell Resources" on
page 816. TX i ic
•
R UL
•
page 816. M : Bearer efficiency (bits/symbol) of the bearer assigned to the pixel, subscriber, or mobile Mi in the downlink in
: Amount of uplink resources in the cell TXi(ic) as calculated in "Calculation of Total Cell Resources" on
•
"C/(I+N) and Bearer Calculation (DL)" on page 807. M : Bearer efficiency (bits/symbol) of the bearer assigned to the pixel, subscriber, or mobile Mi in the uplink in "C/
i B DL
B
i UL
(I+N) and Bearer Calculation (UL)" on page 813. •
TX i ic
CNR DL
: Downlink C/N the cell TXi(ic) as calculated in "C/N Calculation (DL)" on page 806.
TX i ic
•
T AMS : AMS threshold defined for the cell TXi(ic).
•
i i BLER B DL : Downlink block error rate read from the BLER vs. CINR DL
TX ic
M
graph available in the Wi-Fi equipment
assigned to the terminal used by the pixel, subscriber, or mobile Mi. •
M
M
i i BLER B UL : Uplink block error rate read from the BLER vs. CINR UL graph available in the Wi-Fi equipment assigned
to the cell TXi(ic). •
Mi
f TP – Scaling : Throughput scaling factor defined in the properties of the service used by the pixel, subscriber, or mobile Mi. Mi
•
TP Offset : Throughput offset defined in the properties of the service used by the pixel, subscriber, or mobile Mi.
•
N Users – DL : Number of users connected to the cell TXi(ic) in downlink.
•
N Users – UL : Number of users connected to the cell TXi(ic) in uplink.
TX i ic TX i ic
Calculations Downlink: •
M
i
TX ic i
Peak MAC Channel Throughput: CTP P – DL = R DL
M i B DL
MIMO – SU-MIMO Gain:
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If the frame configuration supports AMS, SU-MIMO gain G SU – MIMO is applied to the bearer efficiency. The gain is read from the properties of the Wi-Fi equipment assigned to the pixel, subscriber, or mobile Mi for: TX ic i
•
N Ant – TX : Number of MIMO transmission (downlink) antennas defined for the cell TXi(ic).
•
N Ant – RX : Number of MIMO reception (downlink) antennas defined for the terminal used by the pixel, subscriber,
M
i
or mobile Mi. •
Mobility M i : Mobility used for the calculations.
•
B DL : Bearer assigned to the pixel, subscriber, or mobile Mi in the downlink as explained in "C/(I+N) and Bearer
Mi
Calculation (DL)" on page 807. •
M
i BLER B DL : Downlink block error rate read from the graphs available in the Wi-Fi equipment assigned to the TX i ic
terminal used by the pixel, subscriber, or mobile Mi. BLER is determined for CINR DL
.
Atoll also takes into account the SU-MIMO Gain Factor f SU – MIMO defined for the clutter class where the pixel, subscriber, or mobile Mi is located.
Mi
B DL
TX i ic
Max
=
Mi
1 + f SU – MIMO G SU – MIMO – 1 if CNR DL
TX i ic
T AMS
B DL
If the Max SU-MIMO Gain for the exact value of the C/(I+N) is not available in the table, it is interpolated from the gain values available for the C/(I+N) just less than and just greater than the actual C/(I+N). •
M
M
M
i i i Effective MAC Channel Throughput: CTP E – DL = CTP P – DL 1 – BLER B DL M
i CTP A – DL
=
Mi
M
i CTP E – DL
M f TP – Scaling i - – TP Offset -----------------------100
•
Application Channel Throughput:
•
Peak MAC Cell Capacity: Cap P – DL = CTP P – DL TL DL – Max
•
i i i Effective MAC Cell Capacity: Cap E – DL = Cap P – DL 1 – BLER B DL
•
•
Mi
TX i ic
Mi
M
Application Cell Capacity:
M
i Cap A – DL
M
Mi
M
i Cap E – DL
=
Mi
Peak MAC Throughput per User: PUTP P – DL
M
M f TP – Scaling i - – TP Offset -----------------------100 Mi
Cap P – DL = ----------------------TX i ic N Users – DL Mi
•
•
Mi Cap E – DL Effective MAC Throughput per User: PUTP E – DL = ----------------------TX i ic N Users – DL Mi
Application Throughput per User: PUTP A – DL
Mi
Mi f TP – Scaling - – TP Offset = PUTP E – DL -----------------------100 Mi
Uplink: •
M
i
TX ic i
Peak MAC Channel Throughput: CTP P – UL = R UL
M i B UL
MIMO – SU-MIMO Gain: Max
If the frame configuration supports AMS, SU-MIMO gain G SU – MIMO is applied to the bearer efficiency. The gain is read from the properties of the Wi-Fi equipment assigned to the cell TXi(ic) for: •
Mi
N Ant – TX : Number of MIMO transmission (uplink) antennas defined for the terminal used by the pixel, subscriber, or mobile Mi.
•
818
TX i ic
N Ant – RX : Number of MIMO reception (uplink) antennas defined for the cell TXi(ic).
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AT330_TRR_E1
•
Mobility M i : Mobility used for the calculations.
•
B UL : Bearer assigned to the pixel, subscriber, or mobile Mi in the uplink as explained in "C/(I+N) and Bearer Calculation (UL)" on page 813.
•
M
i
M
i BLER B UL : Uplink block error rate read from the graphs available in the Wi-Fi equipment assigned to the cell Mi
TXi(ic). BLER is determined for CINR UL . Atoll also takes into account the SU-MIMO Gain Factor f SU – MIMO defined for the clutter class where the pixel, subscriber, or mobile Mi is located.
Mi
=
B UL
TX i ic
Max
Mi
1 + f SU – MIMO G SU – MIMO – 1 if CNR DL
TX i ic
T AMS
B UL
If the Max SU-MIMO Gain for the exact value of the C/(I+N) is not available in the table, it is interpolated from the gain values available for the C/(I+N) just less than and just greater than the actual C/(I+N). •
M
M
M
i i i Effective MAC Channel Throughput: CTP E – UL = CTP P – UL 1 – BLER B UL Mi
Mi f TP – Scaling - – TP Offset = CTP E – UL -----------------------100
Mi
Mi
•
Application Channel Throughput: CTP A – UL
•
Peak MAC Cell Capacity: Cap P – UL = CTP P – UL TL UL – Max
•
i i i Effective MAC Cell Capacity: Cap E – UL = Cap P – UL 1 – BLER B UL
•
Mi
M
Mi
TX i ic
Mi
Application Cell Capacity: Cap A – UL
M
M
Mi
Mi f TP – Scaling - – TP Offset = Cap E – UL -----------------------100 Mi
Mi
•
•
•
Mi Cap P – UL Peak MAC Throughput per User: PUTP P – UL = ----------------------TX i ic N Users – UL Mi
Mi
Effective MAC Throughput per User: PUTP E – UL
Mi
Application Throughput per User: PUTP A – UL
Cap E – UL = ----------------------TX i ic N Users – UL Mi
Mi f TP – Scaling - – TP Offset = PUTP E – UL -----------------------100 Mi
Output Mi
•
CTP P – DL : Downlink peak MAC channel throughput at the pixel, subscriber, or mobile Mi.
•
CTP E – DL : Downlink effective MAC channel throughput at the pixel, subscriber, or mobile Mi.
•
CTP A – DL : Downlink application channel throughput at the pixel, subscriber, or mobile Mi.
•
Cap P – DL : Downlink peak MAC cell capacity at the pixel, subscriber, or mobile Mi.
•
Cap E – DL : Downlink effective MAC cell capacity at the pixel, subscriber, or mobile Mi.
•
Cap A – DL : Downlink application cell capacity at the pixel, subscriber, or mobile Mi.
•
PUTP P – DL : Downlink peak MAC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP E – DL : Downlink effective MAC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP A – DL : Downlink application throughput per user at the pixel, subscriber, or mobile Mi.
•
CTP P – UL : Uplink peak MAC channel throughput at the pixel, subscriber, or mobile Mi.
Mi M
i
Mi Mi Mi
Mi M
i
Mi
Mi
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i
•
CTP E – UL : Uplink effective MAC channel throughput at the pixel, subscriber, or mobile Mi.
•
CTP A – UL : Uplink application channel throughput at the pixel, subscriber, or mobile Mi.
•
Cap P – UL : Uplink peak MAC cell capacity at the pixel, subscriber, or mobile Mi.
•
Cap E – UL : Uplink effective MAC cell capacity at the pixel, subscriber, or mobile Mi.
•
Cap A – UL : Uplink application cell capacity at the pixel, subscriber, or mobile Mi.
•
PUTP P – UL : Uplink peak MAC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP E – UL : Uplink effective MAC throughput per user at the pixel, subscriber, or mobile Mi.
•
PUTP A – UL : Uplink application throughput per user at the pixel, subscriber, or mobile Mi.
M
M
i
i
Mi Mi
Mi Mi Mi
11.4.6 Scheduling and Radio Resource Management Wi-Fi scheduling and RRM algorithms are explained in "Scheduling and Radio Resource Allocation" on page 820 and the calculation of user throughputs is explained in "User Throughput Calculation" on page 823.
11.4.6.1 Scheduling and Radio Resource Allocation Input TX i ic
•
TL DL – Max : Maximum downlink traffic load for the cell TXi(ic).
•
TL UL – Max : Maximum uplink traffic load for the cell TXi(ic).
•
N Users – Max : Maximum number of users defined for the cell TXi(ic).
•
p
•
TPD Min – DL : Downlink minimum throughput demand for the service accessed by a mobile Mi.
•
TPD Min – UL : Uplink minimum throughput demand for the service accessed by a mobile Mi.
•
TPD Max – DL : Downlink maximum throughput demand for the service accessed by a mobile Mi.
•
TPD Max – UL : Uplink maximum throughput demand for the service accessed by a mobile Mi.
•
•
TX ic i
TX i ic
Mi
: Priority of the service accessed by a mobile Mi. Mi Mi Mi Mi
TX ic
M
i i BLER BDL : Downlink block error rate read from the BLER vs. CINR DL assigned to the terminal used by the mobile Mi. M
graph available in the Wi-Fi equipment
M
i i BLER BUL : Uplink block error rate read from the BLER vs. CINR UL graph available in the Wi-Fi equipment assigned to the cell TXi(ic). Mi
•
f TP – Scaling : Throughput scaling factor defined in the properties of the service used by the mobile Mi.
•
TP Offset : Throughput offset defined in the properties of the service used by the mobile Mi.
•
CTP P – DL : Downlink peak MAC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on
Mi
Mi
page 816. •
Mi
CTP E – DL : Downlink effective MAC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on page 816. Mi
•
CTP P – UL : Uplink peak MAC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on page 816.
•
CTP E – UL : Uplink effective MAC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on
Mi
page 816.
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Calculations The following calculations are described for any cell TXi(ic) containing the users Mi for which it is the best server. Mobile Selection: TX ic i
The scheduler selects N Users mobiles for the scheduling and RRM process. If the Monte Carlo user distribution has generated TX i ic
a number of users which is less than N Users – Max , the scheduler keeps all the mobiles generated for the cell TXi(ic). TX ic
TX ic
TX ic
i i i N Users = Min N Users – Max N Users – Generated Sel
For a cell, mobiles M i
TX ic i
N Users are selected for RRM by the scheduler.
Resource Allocation for Minimum Throughput Demands: Sel
1. Atoll sorts the M i
Sel
2. Starting with M i
TX i ic
N Users in order of decreasing service priority, p Sel
= 1 up to M i
Sel Mi
:
= N , Atoll allocates the downlink and uplink resources required to satisfy each
user’s minimum throughput demands in downlink and uplink as follows: Sel Mi
Sel Mi
R Min – DL
Sel Mi
Sel
Mi TPD Min – DL TPD Min – UL = -------------------------- and R Min – UL = -------------------------Sel Mi
Sel Mi
CTP P – DL
CTP P – UL
3. Atoll stops the resource allocation in downlink or uplink, •
When/If in downlink
Sel Mi
TX i ic
R Min – DL = TL DL – Max , i.e., the resources available in downlink have been used up for
Sel Mi
satisfying the minimum throughput demands of the mobiles. •
When/If in uplink
M
Sel i
TX ic i
R Min – UL = TL UL – Max , i.e., the resources available in uplink have been used up for
Sel Mi
satisfying the minimum throughput demands of the mobiles. 4. Mobiles which are active DL+UL must be able to get their minimum throughput demands in both UL and DL in order to be considered connected DL+UL. If an active DL+UL mobile is only able to get its minimum throughput demand in one direction, it is rejected, and the resources, that were allocated to it in the one direction in which it was able to get a throughput, are allocated to other mobiles. 5. If
Sel Mi
TX i ic
R Min – DL TL DL – Max or
Sel Mi
Sel Mi
TX i ic
R Min – UL TL UL – Max , and all the minimum throughput resources demanded by
Sel Mi
the mobiles have been allocated, Atoll goes to the next step for allocating resources to satisfy the maximum throughput demands. Backhaul Saturation: If at this stage, a site’s downlink or uplink effective MAC aggregate throughput exceeds its maximum downlink or uplink backhaul throughput, respectively, mobiles are rejected one by one due to Backhaul Saturation, starting from the mobile with the lowest priority service, among all the cells of the site in order to reach a downlink or uplink effective MAC aggregate site throughput ≤ the site’s maximum downlink or uplink backhaul throughput. Resource Allocation for Maximum Throughput Demands: For each cell, the remaining cell resources available are: TX ic i
TX ic i
Downlink: R Rem – DL = TL DL – Max –
M
Sel i
R Min – DL
Sel Mi
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TX ic i
M
Uplink: R Rem – UL = TL UL – Max –
M
Sel i
R Min – UL
Sel i
For each mobile, the throughput demands remaining once the minimum throughput demands have been satisfied are the difference between the maximum and the minimum throughput demands: Sel Mi
Sel Mi
Sel Mi
Downlink: TPD Rem – DL = TPD Max – DL – TPD Min – DL M
Sel i
M
Sel i
M
Sel i
Uplink: TPD Rem – UL = TPD Max – UL – TPD Min – UL Sel
Let the total number of users with remaining throughput demands greater than 0 be N M i . 1. Atoll divides the remaining resources in the cell into equal parts for each user: TX i ic
TX i ic
R Rem – DL R Rem – UL --------------------- and -------------------N N 2. Atoll converts the remaining throughput demands of all the users to their respective remaining resource demands: Sel Mi
Sel Mi
RD Rem – DL
Sel Mi
Sel
Mi TPD Rem – DL TPD Rem – UL = --------------------------- and RD Rem – UL = --------------------------Sel Mi
Sel Mi
CTP P – DL
CTP P – UL
Remaining resource demands of a user are given by the ratio between its remaining throughput demands and the peak channel throughputs at the user’s location. 3. The resources allocated to each user for satisfying its maximum throughput demands are: Sel i R Max – DL M
TX i ic
Sel
Sel
Sel
TX i ic
M Mi Mi R Rem – DL R Rem – UL i = Min RD Rem – DL --------------------- and R Max – UL = Min RD Rem – UL --------------------- N N
Each user gets either the resources it needs to achieve its maximum throughput demands or an equal share from the remaining resources of the cell, whichever is smaller. 4. Atoll stops the resource allocation in downlink or uplink, •
Sel Mi
When/If in downlink
TX i ic
R Max – DL = R Rem – DL , i.e., the resources available in downlink have been used up for
Sel Mi
satisfying the maximum throughput demands of the mobiles. •
When/If in uplink
Sel Mi
TX i ic
R Max – UL = R Rem – UL , i.e., the resources available in uplink have been used up for satisfying
Sel Mi
the maximum throughput demands of the mobiles. 5. If the resources allocated to a user satisfy its maximum throughput demands, this user is removed from the list of remaining users. 6. Atoll recalculates the remaining resources as follows: TX i ic
TX i ic
R Rem – DL = TL DL – Max –
Sel Mi
R Min – DL –
Sel Mi TX i ic
TX i ic
R Rem – UL = TL UL – Max –
Sel Mi
R Max – DL and
Sel Mi Sel Mi
R Min – UL –
Sel Mi
Sel Mi
R Max – UL
Sel Mi
7. Atoll repeats the all the above steps for the users whose maximum throughput demands have not been satisfied until TX i ic
TX i ic
either R Rem – DL = 0 and R Rem – UL = 0 , or all the maximum throughput demands are satisfied. Backhaul Capacity Limitation:
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Backhaul overflow ratios are calculated for each site as follows: Sel Sel M Mi i R Max – DL CTP E – DL Sel M Site i - and = Max 1 ----------------------------------------------------------------------------------------------------- Sel Sel Mi Mi Site R Min – DL CTP E – DL TP BH – DL – Sel M i Site
Site
BHOFDL
Sel Sel Mi Mi R Max – UL CTP E – UL Sel M i Site = Max 1 ------------------------------------------------------------------------------------------------------- Sel Sel Mi Mi Site TP – R CTP Min – UL BH – UL E – UL Sel M i Site
Site BHOFUL
Total Amount of Resources Assigned to Each Selected Mobile: Sel
Atoll calculates the amounts of downlink and uplink resources allocated to each individual mobile M i
(which can also be
referred to as the traffic loads of the mobiles) as follows: Sel
Sel Mi
Downlink: TL DL
Sel Mi
= R DL
Sel Mi
Sel Mi
R Mi Mi Max – DL CTP P – DL R Min – DL CTP P – DL + -----------------------------------------------Site BHOF DL = -----------------------------------------------------------------------------------------------------------------Sel
Sel Mi
CTP P – DL Sel
Sel Mi
Uplink: TL UL
Sel Mi
= R UL
Sel Mi
Sel Mi
R M Mi i Max – UL CTP P – UL R Min – UL CTP P – UL + -----------------------------------------------Site BHOF UL = -----------------------------------------------------------------------------------------------------------------Sel
Sel Mi
CTP P – UL Output Sel Mi
•
TL DL
•
TL UL
Sel Mi
Sel Mi
= R DL
Sel
: Downlink traffic load or the amount of downlink resources allocated to the mobile M i .
Sel Mi
Sel
= R UL : Uplink traffic load or the amount of uplink resources allocated to the mobile M i .
11.4.6.2 User Throughput Calculation User throughputs are calculated for the percentage of resources allocated to each mobile selected by the scheduling for RRM Sel
during the Monte Carlo simulations, M i . Input
•
Sel Mi
R DL
Sel
: Amount of downlink resources allocated to the mobile M i
as calculated in "Scheduling and Radio Resource
Allocation" on page 820. •
Sel Mi
Sel
R UL : Amount of uplink resources allocated to the mobile M i
as calculated in "Scheduling and Radio Resource
Allocation" on page 820. •
Sel Mi
Sel
CTP P – DL : Downlink peak MAC channel throughput at the mobile M i
as calculated in "Throughput Calculation" on
page 816. •
Sel Mi
Sel
CTP P – UL : Uplink peak MAC channel throughput at the mobile M i
as calculated in "Throughput Calculation" on
page 816.
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Sel
•
TX ic Mi i BLER BDL : Downlink block error rate read from the BLER vs. CINR Traffic graph available in the Wi-Fi equipment Sel
assigned to the terminal used by the mobile M i . Sel
•
M Mi i BLER BUL : Uplink block error rate read from the BLER vs. CINR UL graph available in the Wi-Fi equipment assigned to the cell TXi(ic). Sel Mi
Sel
•
f TP – Scaling : Throughput scaling factor defined in the properties of the service used by the mobile M i
•
TP Offset : Throughput offset defined in the properties of the service used by the mobile M i
Sel Mi
Sel
Calculations Downlink: Sel Mi
Sel Mi
Sel Mi
CTP P – DL
•
Peak MAC User Throughput: UTP P – DL = R DL
•
Mi Mi Mi Effective MAC User Throughput: UTP E – DL = UTP P – DL 1 – BLER B DL
Sel
•
Sel Mi
Application User Throughput: UTP A – DL
Sel
Sel
Sel Mi
Sel Mi
Sel
Mi f TP – Scaling - – TP Offset = UTP E – DL -----------------------100
Uplink: Sel Mi
Sel Mi
Sel Mi
CTP P – UL
•
Peak MAC User Throughput: UTP P – UL = R UL
•
M M Mi i i Effective MAC User Throughput: UTP E – UL = UTP P – UL 1 – BLER B UL
Sel
•
Sel Mi
Application User Throughput: UTP A – UL
Sel
Sel Mi
Sel
Sel Mi
Sel
Mi f TP – Scaling - – TP Offset = UTP E – UL -----------------------100
Output Sel Mi
UTP P – DL : Downlink peak MAC user throughput at the pixel, subscriber, or mobile M i
•
UTP E – DL : Downlink effective MAC user throughput at the pixel, subscriber, or mobile M i .
.
Sel Mi
Sel
Sel Mi
Sel
•
UTP A – DL : Downlink application user throughput at the pixel, subscriber, or mobile M i .
•
UTP P – UL : Uplink peak MAC user throughput at the pixel, subscriber, or mobile M i
•
UTP E – UL : Uplink effective MAC user throughput at the pixel, subscriber, or mobile M i .
•
UTP A – UL : Uplink application user throughput at the pixel, subscriber, or mobile M i
Sel Mi
Sel Mi
The following sections describe the algorithms for: • • •
Sel
.
Sel Mi
11.5 Automatic Planning Algorithms
824
Sel
•
"Automatic Neighbour Planning" on page 825. "Automatic Inter-technology Neighbour Planning" on page 829. "Automatic Frequency Planning Using the AFP" on page 831.
Sel
Sel
.
.
.
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11.5.1 Automatic Neighbour Planning The intra-technology neighbour planning algorithm takes into account the cells of all the TBC transmitters. It means that the cells of all the TBC transmitters of your ATL document are potential neighbours. The cells to be allocated will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone, They belong to the folder on which the allocation has been executed. This can be the Transmitters folder or a group of transmitters (subfolder).
Only TBA cells are assigned neighbours. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
We assume a reference cell TXi(ic) and a candidate neighbour cell TXj(jc). When automatic planning starts, Atoll checks the following conditions: 1. The distance between both cells must be less than the user-definable maximum inter-site distance. If the distance between the reference cell and the candidate neighbour is greater than this value, then the candidate neighbour is discarded. Atoll calculates the effective distance between the reference cell and its candidate neighbour from the real distance between them and the azimuths of their antennas: Dist CellA CellB = D 1 + x cos – x cos Where x = 0.3% so that the maximum variation in D does not to exceed 1%. D is stated in m.
Figure 11.3: Inter-Transmitter Distance Calculation The formula above implies that two cells facing each other have a smaller effective distance than the actual distance. Candidate neighbours are ranked in the order of increasing effective distance from the reference cell. 2. The calculation options, •
•
Force Co-site Cells as Neighbours: If selected, Atoll adds all the cells located on the same site as the reference cell to the candidate neighbour list. The weight of this constraint can be defined. It is used to calculate the rank of each neighbour, and its importance. Force Adjacent Cells as Neighbours: If selected, Atoll adds all the cells geographically adjacent to the reference cell to the candidate neighbour list. The weight of this constraint can be defined. It is used to calculate the rank of each neighbour, and its importance.
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Figure 11.4: Determination of Adjacent Cells Determination of Adjacent Cells: Geographically adjacent cells are determined on the basis of their best server coverage areas. A candidate neighbour cell TXi(ic) is considered adjacent to the reference cell TXi(ic) if there exists at least one pixel of TXj(jc)’s best server coverage area where TXi(ic) is the second best server. The ranking of adjacent neighbour cells increases with the number of such pixels. Adjacent cells are sorted in the order of decreasing rank. •
Force Symmetry: If selected, Atoll adds the reference cell to the candidate neighbour list of the its candidate neighbour. A symmetric neighbour relation is allowed only if the neighbour list of the reference cell is not already full. If TXj(jc) is a neighbour of TXi(ic) but TXi(ic) is not a neighbour of TXj(jc), there can be two possibilities: i.
The neighbour list of TXj(jc) is not full, Atoll will add TXi(ic) to the end of the list.
ii. The neighbour list of TXj(jc) is full, Atoll will not be able to add TXi(ic) to the list, so it will also remove TXj(jc) from the neighbour list of TXi(ic). If the neighbours list of a cell is full, the reference cell will not be added as a neighbour of that cell and that cell will be removed from the reference cell’s neighbours list. You can force Atoll to keep that cell in the reference cell’s neighbours list by adding the following option in the Atoll.ini file: [Neighbours] DoNotDeleteSymmetrics = 1 •
Force Exceptional Pairs: This option enables you to force/forbid some neighbour relations. Exceptional pairs are pairs of cells which will always or never be neighbours of each other. If you select "Force exceptional pairs" and "Force symmetry", Atoll considers the constraints between exceptional pairs in both directions so as to respect symmetry condition. On the other hand, if neighbourhood relationship is forced in one direction and forbidden in the other, symmetry cannot be respected. In this case, Atoll displays a warning in the Event viewer.
•
Delete Existing Neighbours: If selected, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, the existing neighbours are kept in the list.
3. If the Use Coverage Conditions check box is selected, the coverage areas of TXi(ic) and TXj(jc) must have an overlap ( S TX ic S TX jc ).Otherwise, only the distance criterion is taken into account. i
j
The overlapping zone ( S TX ic S TX jc ) is defined as follows: i
•
j
Here S TX ic is the surface area covered by the cell TXi(ic) that comprises all the pixels where: i
•
The received signal level is greater than or equal to the signal level threshold. The received signal level TX i ic
( C DL
TX i ic
) and the signal level threshold are calculated from CNR DL TX i ic
value of the noise ( n DL •
TX i ic
and T Min
, respectively, by adding the
) to them. TX ic i
S TX ic is the surface area covered by TXi(ic) within C DL i
TX ic i
+ HO Start and C DL
+ HO End . HOStart is the
margin with respect to the best signal level at which the handover starts, and HO End is the margin with respect to the best signal level at which the handover ends.
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•
S TX jc is the coverage area where the candidate cell TXj(jc) is the best server. j
•
•
•
TX ic i
If a global value of the C/N threshold ( T Min
) is set in the coverage conditions
dialogue, for each cell, Atoll uses the higher of the two values, i.e., global value and the value defined for that cell. For calculating the overlapping coverage areas, Atoll uses the service with the lowest body loss, the terminal that has the highest difference between gain and losses, and the shadowing margin calculated using the defined cell edge coverage probability, if the option is selected. The service and terminal are selected such that the selection gives the largest possible C/N coverage areas for the cells. Atoll
S TX ic S TX jc i j - 100 ), When the above conditions are met, Atoll calculates the percentage of the coverage area overlap ( -------------------------------------S TX ic i
and compares this value with the % Min Covered Area.
Figure 11.5: Overlapping Zones S TX ic S TX jc i j TXj(jc) is considered a neighbour of TXi(ic) if --------------------------------------- 100 % Min Coverage Area . S TX ic i
Next, Atoll calculates the importance of the automatically allocated neighbours. Atoll sorts the neighbours by decreasing importance in order to keep the ones with high importance. If the maximum number of neighbours to be allocated to each cell is exceeded, Atoll keeps the ones with high importance. The neighbour importance depends on the distance from the reference transmitter and on the neighbourhood cause (cf. table below); this value varies between 0 and 100%. Neighbourhood cause
When
Importance value
Existing neighbour
Only if the Delete Existing Neighbours option is not selected and in case of a new allocation
Existing importance
Exceptional pair
Only if the Force Exceptional Pairs option is selected
100 %
Co-site cell
Only if the Force Co-site Cells as Neighbours option is selected
Importance Function (IF)
Adjacent cell
Only if the Force Adjacent Cells as Neighbours option is selected
Importance Function (IF)
Neighbourhood relationship that fulfils coverage conditions
Only if the % Min Covered Area is exceeded
Importance Function (IF)
Symmetric neighbourhood relationship
Only if the Force Neighbour Symmetry option is selected
Importance Function (IF)
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The importance is evaluated using an Importance Function (IF), which takes into account the following factors: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance ( D in m) weighted by the azimuths of antennas. d max is the maximum distance between the reference transmitter and a possible neighbour.
• • •
The co-site factor (C): a Boolean, The adjacency factor (A): the percentage of adjacency, The overlapping factor (O): the percentage of overlapping.
The minimum and maximum importance assigned to each of the above factors can be defined. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
30%
Adjacency factor (A)
Min(A)
30%
Max(A)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The Importance Function is evaluated as follows: Neighbourhood cause
Importance Function
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%Max(Di))(O)}+Min(Di)+Delta(Di)(Di)
10%+20%{10%(Di)+90%(O)}+1%+9%(Di)
No
Yes
Min(A)+Delta(A){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
30%+30%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Yes
Yes
Min(C)+Delta(C){Max(Di)(Di)+Max(O)(O)+ (100%-Max(Di)-Max(O))(A)}+Min(Di)+Delta(Di)(Di)
60%+40%{10%(Di)+30%(O) +60%(A)}+1%+9%(Di)
Co-site
Adjacent
No
Where: Delta(X)=Max(X)-Min(X) • •
•
•
Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours, adjacent neighbours, and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes. The default value of Min(O) = 1% ensures that neighbours selected for symmetry will have an importance greater than 0%. With a value of Min(O) = 0%, neighbours selected for symmetry will have an importance field greater than 0% only if there is some coverage overlapping.If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes.
In the results, Atoll lists only the cells for which it finds new neighbours. Cells whose channels have the same start frequency, the same channel width, and the same total number of subcarriers are listed as intra-carrier neighbours. Otherwise, neighbour cells are listed as inter-carrier neighbours.
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•
By default, the automatic neighbour allocation compares the defined Max intersite distance with the effective inter-cell distance. As a consequence, there can be cases where the real distance between assigned neighbours is higher than the Max inter-site distance, because the effective distance is smaller. You can force Atoll to compare the Max inter-site distance with the real inter-site distance by adding the following lines in Atoll.ini: [Neighbours] RealInterSiteDistanceCondition=1
•
By default, the neighbour importance calculated with respect to distance is based on the global Max inter-site distance setting for all neighbour candidates. As a consequence, there can be cases where the calculated importance is different when the global Max inter-site distance is modified. To avoid that, you can force Atoll to prioritise the individual distances between reference cells and their respective neighbour candidates by adding the following lines in Atoll.ini: [Neighbours] CandidatesMaxDistanceInImportanceCalculation=1
11.5.2 Automatic Inter-technology Neighbour Planning The inter-technology neighbour planning algorithm takes into account all the TBC transmitters (if the other technology is GSM) or the cells of all the TBC transmitters (for any other technology than GSM). This means that all the TBC transmitters (GSM) or the cells of all the TBC transmitters (all other technologies) of the linked document are potential neighbours. The cells to be allocated in the main document will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone, They belong to the folder on which allocation has been executed. This can be the Transmitters folder or a group of transmitters (subfolder).
Only TBA cells are assigned neighbours. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
We assume a reference cell A and a candidate neighbour B. When automatic planning starts, Atoll checks following conditions: 1. The distance between reference cell and the candidate neighbour must be less than the user-definable maximum inter-site distance. If the distance is greater than this value, the candidate neighbour is discarded. Atoll calculates the effective distance between the reference cell and its candidate neighbour from the real distance between them and the azimuths of their antennas: Dist CellA CellB = D 1 + x cos – x cos Where x = 0.3% so that the maximum variation in D does not to exceed 1%. D is stated in m.
Figure 11.6: Inter-Transmitter Distance Calculation The formula above implies that two cells facing each other have a smaller effective distance than the actual distance. Candidate neighbours are ranked in the order of increasing effective distance from the reference cell. 2. The calculation options:
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•
•
• •
©Forsk 2015
CDMA Carriers: This option is available when a Wi-Fi network is being co-planned with a UMTS, CDMA, or TDSCDMA network. This option enables you to select the CDMA carrier(s) that you want Atoll to consider as potential neighbours of Wi-Fi cells. You may choose one or more carriers. Atoll will allocate only the cells using the selected carriers as neighbours. Force co-site cells as neighbours: If selected, Atoll adds all the transmitters/cells located on the same site as the reference cell in its candidate neighbour list. The weight of this constraint can be defined. It is used to calculate the rank of each neighbour and its importance. Force exceptional pairs: This option enables you to force/forbid some neighbour relations. Exceptional pairs are pairs of cells which will always or never be neighbours of each other. Delete existing neighbours: If selected, Atoll deletes all the current neighbours and carries out a new neighbour allocation. If not selected, the existing neighbours are kept in the list.
3. Neighbour relation criterion: •
Allocation based on distance: The allocation algorithm is based on the effective distance between the reference cell and its candidate neighbour.
•
Algorithm based on coverage overlapping: The coverage areas of the reference cell A and the candidate neighbour B must overlap ( S A S B ). Two cases may exist for SA: •
1st case: SA is the area where the cell A is the best serving cell, with a 0dB margin. This means that the signal received from A is greater than the minimum required (calculated from the C/N threshold), and is the highest one.
•
2nd case: The margin is other than 0 dB. SA is the area where: The signal level received from A exceeds the minimum required (calculated from the C/N threshold) and is within a margin from the highest signal level.
Two cases may exist for SB: •
1st case: SB is the area where the candidate neighbour is the best server. In this case, the margin must be set to 0 dB. The signal level received from B exceeds the minimum required, and is the highest one.
•
2nd case: The margin is other than 0 dB. SB is the area where: The signal level received from B exceeds the minimum required and is within a margin from the best signal level.
SA SB Atoll calculates the percentage of the coverage area overlap ( ------------------ 100 ) and compares this value with the % SA SA SB Min Covered Area. B is considered a neighbour of A if ------------------ 100 % Min Covered Area . SA Candidate neighbours are ranked in the order of decreasing coverage area overlap percentages. Next, Atoll calculates the importance of the automatically allocated neighbours. Atoll sorts the neighbours by decreasing importance in order to keep the ones with high importance. If the maximum number of neighbours to be allocated to each cell is exceeded, Atoll keeps the ones with high importance. The importance (%) of neighbours depends on the distance and on the reason of allocation: •
830
For allocation based on distance: Neighbour cause
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter/cell
If the Force co-site cells as neighbours option is selected
100 %
Neighbour relation that fulfils distance conditions
If the maximum distance is not exceeded
d1 – ---------d max
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d is the effective distance between the reference cell and the neighbour and d max is the maximum inter-site distance. •
For allocation based on coverage overlapping: Neighbour cause
When
Importance value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter/cell
If the Force co-site cells as neighbours option is selected
IF
Neighbourhood relationship that fulfils coverage conditions
If the % minimum covered area is exceeded
IF
The importance is evaluated using an Importance Function (IF), which takes into account the following factors: •
The distance factor (Di) denoting the distance between the possible neighbour transmitter and the reference transmitter. d Di = 1 – ---------d max d is the effective distance (in m). It corresponds to the real inter-transmitter distance weighted by the azimuths of antennas. d max is the maximum distance between the reference transmitter and a possible neighbour.
• •
The co-site factor (C): a Boolean, The overlapping factor (O): the percentage of overlapping.
The IF is user-definable using the Min importance and Max importance fields. Factor
Min importance
Default value
Max importance
Default value
Distance factor (Di)
Min(Di)
1%
Max(Di)
10%
Overlapping factor (O)
Min(O)
10%
Max(O)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The IF evaluates importance as follows: Co-site Neighbourhood cause
IF
Resulting IF using the default values from the table above
No
Min(O)+Delta(O){Max(Di)(Di)+(100%-Max(Di))(O)}
10%+50%{10%(Di)+90%(O)}
Yes
Min(C)+Delta(C){Max(Di)(Di)/(Max(Di)+Max(O))+ Max(O)(O)/(Max(Di)+Max(O))}
60%+40%{1/7%(Di)+6/7%(O)}
Where Delta(X)=Max(X)-Min(X) • •
•
Set Min(Di) and Max(Di) to 0% if you do not want to take into account the distance factor in the importance calculation. If the Min and Max value ranges of the importance function factors do not overlap, the neighbours will be ranked by neighbour cause. With the default values for minimum and maximum importance fields, neighbours will be ranked in this order: co-site neighbours and neighbours allocated based on coverage overlapping. If the Min and Max value ranges of the importance function factors overlap, the neighbours may be ranked differently. There can be a mix of the neighbourhood causes.
In the results, Atoll displays only the cells for which it finds new neighbours.
11.5.3 Automatic Frequency Planning Using the AFP The role of an Automatic Frequency Planning (AFP) tool is to assign frequencies (channels) to cells of a network such that the overall network performance is optimised. In other words, the interference within the network is reduced as much as possible. Co-channel interference is the main reason for overall network quality degradation in Wi-Fi. In order to improve network performance, the Wi-Fi AFP tries to minimise co- and adjacent channel interference as much as possible while respecting any
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constraints input to it. The main constraints are the resources available for allocation, i.e., the number of frequencies with which the AFP can work, and the relationships to take into account, i.e., interference matrices, neighbours, and distance between transmitters. The AFP is based on a cost function which represents the interference level in the network. The aim of the AFP is to minimise the cost. The best, or optimum, frequency plan is the one which corresponds to the lowest cost. The following describes the AFP’s automatic planning method for frequencies in Wi-Fi networks, which takes into account interference matrices, neighbour relations, and distance between transmitters. The AFP takes into account the cells of all the TBC transmitters. The cells to be allocated will be called TBA cells. They must fulfil the following conditions: • • • •
They are active, Their channel allocation status is not set to locked, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone. If no focus zone exists in the ATL document, Atoll takes into account the computation zone.
11.5.3.1 Constraint and Relationship Weights The AFP is based on a cost function which takes into account channel separation constraints based on the channel overlap ratio as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 799. Channel separation is studied between each TBA cell and its related cells. Atoll calculates the cost between each individual TBA and related cell, and then the overall cost for the TBA cell. Related cells of a TBA cell are: •
Its neighbours, if the check box "Existing neighbours" is selected, Assigned weight Neighbour = 0.5
•
Cells that are listed in the interference matrix of the TBA cell, Assigned weight IM = 0.3
•
Cells within the cell’s (or the default) minimum reuse distance, if the check box "Reuse distance" is selected, Assigned weight Dis tan ce = 0.2 The sum of the weights assigned to the above relations is 1.
You can modify these weights in your Wi-Fi document. The absolute values of the constraint weights are calculated from the relative weights (%) defined in the Constraint Weights dialogue as follows: % Neighbour Neighbour = ---------------------------------------------------------------------------------% Neighbour + % IM + % Dis tan ce % IM IM = ---------------------------------------------------------------------------------% Neighbour + % IM + % Dis tan ce % Dis tan ce Dis tan ce = ---------------------------------------------------------------------------------% Neighbour + % IM + % Dis tan ce
11.5.3.2 Cost Calculation The cost of the relation between the TBA cell and its related cell is calculated as follows: $
TX i ic – TX j jc
TX i ic – TX j jc
= rO
TX ic – TX jc i j
Where r O page 799.
832
TX i ic – TX j jc
Neighbour Neighbour
TX i ic – TX j jc
+ Dis tan ce Dis tan ce
TX ic – TX j jc
+ i IM IM
is the channel overlap ratio as calculated in "Co- and Adjacent Channel Overlaps Calculation" on
Atoll 3.3.0 Technical Reference Guide for Radio Networks Chapter 11: Wi-Fi Networks
AT330_TRR_E1 TX ic – TX jc i j
TX ic – TX jc i j
Neighbour
is the importance of the relationship between the TBA cell and its related neighbour cell. Neighbour
is
calculated during automatic neighbour planning by Atoll as explained in "Automatic Neighbour Planning" on page 825. For manual neighbour planning, this value is equal to 1. TX ic – TX jc i j
IM
is the importance of the relationship between the TBA cell and its related interfering cell calculated as follows:
TX i ic – TX j jc
TX i ic – TX j jc
IM
= r CCO
TX i ic – TX j jc
TX i ic – TX j jc
IM – CC
and IM – CC
TX i ic – TX j jc
IM – CC
TX i ic – TX j jc
+ r ACO
TX i ic – TX j jc
IM – AC
are respectively the co- and adjacent channel interference probabilities calculated as TX ic – TX jc i j
explained in "Interference Matrix Calculation" on page 833. r CCO
TX ic – TX jc i j
and r ACO
are the co- and adjacent channel
overlap ratios as calculated in "Co- and Adjacent Channel Overlaps Calculation" on page 799. TX i ic – TX j jc
Dis tan ce
is the importance of the relationship between the TBA and its related cell with respect to the distance between
TX i ic – TX j jc
them. Dis tan ce
is calculated as explained in "Distance Importance Calculation" on page 834.
Atoll calculates the quality reduction factor for the TBA cell and its related cell from the cost calculated above as follows: QRF
TX i ic – TX j jc
= 1–$
TX i ic – TX j jc
The quality reduction factor is a measure of the cost of an individual relation. The total cost of the current frequency plan for any TBA cell is given as follows, considering all the cells with which the TBA cell has relations: TX i ic
QRF
$ Total = 1 –
TX i ic – TX j jc
TX j jc
And, the total cost of the current frequency plan for the entire network is simply the sum of the total TBA cell costs calculated above, i.e., $ Total =
TX i ic
$ Total
TX ic i
11.5.3.3 AFP Algorithm The AFP algorithm is an iterative algorithm which: • • • •
Calculates the cost (as described above) of the initial frequency plan, Tries different frequency plans in order to reduce the cost, Memorises the different frequency plans in order to determine the best one, i.e., the frequency plan which provides the lowest total cost, Stops when it is unable to improve the cost of the network, and proposes the last known best frequency plan as the solution.
11.5.4 Appendices 11.5.4.1 Interference Matrix Calculation The co-channel interference probability is calculated as follows: S TX ic i
TX ic – TX jc i j
IM – CC
TX j jc TX i ic + M Quality n DL C DL ----------------------------------------------------------------------- TX i ic TX ic 10 10 T i C DL – 10 Log 10 + 10 Min
= ------------------------------------------------------------------------------------------------------------------------------------------------S TX ic i
The adjacent channel interference probability is calculated as follows:
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TX ic – TX jc i j
IM – AC
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TX jc TX ic TX ic j i i +M +f n C DL Quality ACS – FB DL ------------------------------------------------------------------------------------------------------ TX ic TX ic i 10 10 i C + 10 – 10 Log 10 DL T Min
= ----------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX ic i
For frequencies farther than the adjacent channel, the interference probability is 0. TX i ic
Here S TX ic is the best server coverage area of the cell TXi(ic), that comprises all the pixels where CNR DL i
calculated in "Service Area Calculation" on page 815. S TX ic i
TX i ic
the given condition is true. C DL TX i ic
respectively, n DL
TX j jc
and C DL
Condition
TX i ic
T Min
as
is the best server coverage area of the cell TXi(ic) where
are the received downlink signal levels from the cells TXi(ic) and TXj(jc)
the downlink noise for the cell TXi(ic) as calculated in "Noise Calculation (DL)" on page 804, M Quality is TX ic i
the quality margin used for the interference matrices calculation, and f ACS – FB is the adjacent channel suppression factor defined for the frequency band of the cell TXi(ic).
11.5.4.2 Distance Importance Calculation TX i ic – TX j jc
The distance importance between two cells ( Dis tan ce
TX ic – TX jc i j Dis tan ce
1 2 D Reuse = Log -------------------------------- D TXi ic – TXj jc --------------------------------------------------------2 Log D Reuse
if D
) is calculated as follows:
TX i ic – TX j jc
1
Otherwise
Where D Reuse is the minimum reuse distance, either defined for each TBA cell individually or set for all the TBA cells in the AFP dialogue, and D follows: D D
TX ic – TX jc i j TX i ic – TX j jc
them. d
= d
TX i ic – TX j jc
TX ic – TX jc i j
is the weighted distance between the TBA cell TXi(ic) and its related cell TXj(jc) calculated as
1 + x cos – cos – 2
is weighted according to the azimuths of the TBA cell and its related cell with respect to the straight line joining
TX ic – TX jc i j
is the distance between the two cells considering any offsets with respect to the site locations. x is set TX i ic – TX j jc
to 10 % so that the maximum variation in D due to the azimuths does not exceed 40 %. and are calculated from the azimuths of the two cells as shown in Figure 11.7 on page 834.
Figure 11.7: Weighted Distance Between Cells The above formula implies that two cells facing each other will have a shorter effective distance between them than the real distance, and two cells pointing in opposite directions will have a greater effective distance. The importance of the distance relation is explained in Figure 11.8 on page 835. This figure shows that cells that are located near (based on the effective distance which is weighted by the orientations of the cells) have high importance, which is
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interpreted as a high cost, and cells that are located far have low importance. Cells that are further than the reuse distance do not have any cost related to the distance relation.
Figure 11.8: Importance Based on Distance Relation
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Chapter 12 ACP Module This chapter covers the following topics: •
"Objectives" on page 839
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"Quality Predictions and the Antenna Masking Method" on page 844
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"Configuration" on page 846
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"Multi-RAT and Co-planning Support" on page 848
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"Optimisation Methodology" on page 849
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"Load Balancing Objective" on page 855
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"EMF Exposure" on page 861
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"Shadowing Margin and Indoor Coverage" on page 865
•
"Multi-Storey Optimisation" on page 865
•
"ACP Software Data Flow" on page 868
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12 ACP Module ACP optimises key network parameters in order to improve coverage and quality. The ACP can also select the best sites from a list of candidate sites. Atoll ACP uses user-defined objectives to evaluate the quality and implementation cost of a network reconfiguration. It uses an efficient global search algorithm to test many network configurations and propose the reconfigurations which best meet the objectives. The ACP presents the changes ordered from the most to the least beneficial, allowing phased implementation or implementation of just a subset of the suggested changes. Currently, ACP supports the following single-RAT radio access technologies: GSM, UMTS, CDMA2000, LTE, WiMAX, and Wi-Fi. ACP also supports 3GPP and 3GPP2 multi-RAT documents as well as co-planning.
12.1 Objectives Atoll ACP uses user-defined objectives to evaluate the quality and cost of the network reconfiguration or site selection. In addition, a cost objective can be taken into account to reduce the expected implementation cost.
12.1.1 Quality Objective Each quality objective is a logical combination of defined rules used to evaluate specific quality indicators, which are evaluated in a given zone and for a given traffic profile. An objective can combine several quality indicators from different technology layers. Each quality indicator is technology-dependent, and is consistent with the corresponding coverage predictions in Atoll.
12.1.1.1 Definition and Evaluation The ACP calculates the quality objective using the user-defined resolution within the borders of the computation zone. It calculates the basic quality indicators (RSCP, EcIo, CINR, overlap, etc.) on each pixel of the computation zone. Quality maps covering the computation zone are provided for the initial network (before reconfiguration) and final network (after reconfiguration). Each objective is measured on a defined target zone. The target zone can be either the computation zone, the focus zone, a hot spot, or a zone defined as a group of clutter classes. The objective is calculated only on the subset of pixels belonging to this zone. An objective can also be weighted according to traffic or weighted on a given zone. The defined weight enables you to assign a different importance to different pixels. When using traffic weighting, the pixel weights are taken from Atoll traffic maps. When using zone weighting, the pixel weights are taken from a weight defined with each zone. Both types of weighting can be used at the same time, in which case the zone weight is taken as a supplementary factor to the traffic weight. For more information on how weights are applied, see "Optimisation Methodology" on page 849. An objective is defined by both a set of rules and a target. A pixel is said to be "covered" by the set of rules when it fulfils all the rules according to their logical relationship (OR, AND). A rule is a single quality indicator on a single technology layer fulfilling a defined threshold. An example of combined rules is: (UMTS 2100 - RSCP > -85dBm OR LTE 2010 - C/N > 20dB) The target for the objective defines the required percentage of pixels in the target zone (after applying any defined weight) which must fulfil the rule. For example if the target is 90%, the objective is said to be fulfilled if 90% of the pixels are covered by the objective rule. This is described by the following formula:
Cov Obj =
i 1 Th1 Qual 1 i OR 1 Th2 Qual 2 i
i pixels of zone where, 1 Th is the step function: 1 Th x = 1 if x Th and 1 Th x = 0 if x Th Qual k i is the basic quality measurement on pixel i i is the normalised weight for pixel i:
i = 1
i pixels
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Thresholds on rules can be defined separately per zone or per clutter groups. The target threshold can be defined as absolute or relative compared to initial status: for example as 90% (absolute) or as increase of 5% over current coverage (relative).
12.1.1.2 Progressive Thresholds Progressive thresholds allow the ACP to evaluate the amount of improvement or degradation of each objective, leading to more intelligent decisions on improvements that may cause degradations elsewhere in the network. Progressive thresholds are proposed by default for some quality parameters. When this feature is supported for a quality parameter, the Progressive Threshold check box is enabled in the Thresholds Definition dialog box. You can disable it by setting the useProgressiveThreshold option to 0 in the [ACPCore] section of the ACP.ini file.
Figure 12.1: Thresholds Definition dialog box •
When the Progressive Threshold check box is cleared, a step function (1/0) is used and ACP objectives are evaluated on a "fixed-threshold basis", on each pixel and in a logical manner, whether the objectives are met or not. The step function is described in "Definition and Evaluation" on page 839 and it is used by default in all objectives.
•
When the Progressive Threshold check box is selected, a progressive function is used instead with a weighting varying from 1 to 0, from a maximum to a minimum. Below are the main curve parameters used by the progressive function: •
The options below can be added in the ACP.ini file in order to modify maximum and minimum threshold values (see full option names and default values in the Atoll Administrator Manual): [ACPCore] ..th.min ..th.max
•
Threshold defined in the objective’s properties on the Objectives tab of the ACP setup. This value is used as the transition between two signal level ranges (below and above threshold), each range having its own hard coded modelling.
Main curve parameters can produce several shapes according to the user-defined values. Below is a typical example with the signal level type objective (RSCP) and the default Min/Threshold/Max values (-120dBm/-90dBm/-60dBm).
Figure 12.2: Progressive Thresholds function
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12.1.1.3 Target Filtering Atoll ACP allows you to filter pixels on which the target percentage will be evaluated according to defined filter conditions. When using a filter, the target percentage coverage is not evaluated on all pixels of the target zone, but only on pixels of the target zone which are not filtered out. For example, you could calculate an objective only on the pixels of a zone for which there is no coverage in a given technology: Target: 90% of pixel with UMTS RSCP > -95dB for which GSM Signal Level < -95dBm The 90% target will be applied only to the subset of pixels for which the GSM signal level is below -90dBm
12.1.2 Quality Indicators in the ACP Atoll ACP defines a set of basic quality indicators. These quality indicators are used when defining a rule to form complex objectives. For each quality indicator, Atoll ACP uses the same formulas as used elsewhere in Atoll. This ensures that the measured values are the same in the ACP and in Atoll predictions.
12.1.2.1 GSM Quality Indicators The quality indicators used by ACP give the same maps and results as the reference prediction in Atoll. In the following list, each quality indicator defined in GSM is followed in italics by the reference prediction in Atoll (with the relevant "Field" setting), if any: • • • • • •
BCCH Signal Level (Coverage by Signal Level (DL) + "Best Signal Level (dBm)") used as a measure of raw network coverage. CINR Co-channel (Coverage by C/I Level (DL) + "C/I Level (dB)") Overlap (Overlapping Zones (DL) + "Number of Servers") to define cell dominance and decrease the level of interference between cells while allowing a level of cell overlap. Best Server Distance 1st-2nd Difference 1st-Nth Difference
The ACP manages interference quality in the network by measuring signal pollution: a limited number of overlapping cells are allowed in order to allow for coverage continuity and handover capability. The number should be consistent with the frequency reuse ratio used for the network.
12.1.2.2 UMTS Quality Indicators The quality indicators used by ACP give the same maps and results as the reference prediction in Atoll. In the following list, each quality indicator defined in UMTS is followed in italics by the reference prediction in Atoll (with the relevant "Field" setting), if any: • • • • • • •
RSCP (Coverage by Signal Level (DL) + "Best Signal Level (dBm)") used as a measure of raw network coverage. EcIo (Pilot Quality Analysis (DL) with "Ec/Io (dB)") to define the service area zone. RSSI (Total Noise Level Analysis (DL) + "Max Noise Level (dBm)") Overlap (Overlapping Zones (DL) + "Number of Servers") to measure pilot pollution as well as soft handover quality. Best Server Distance 1st-2nd Difference 1st-Nth Difference
12.1.2.3 CDMA2000 Quality Indicators The quality indicators used by ACP give the same maps and results as the reference prediction in Atoll. In the following list, each quality indicator defined in CDMA2000 is followed in italics by the reference prediction in Atoll (with the relevant "Field" setting), if any: • • • • • •
Signal Level (Coverage by Signal Level (DL) + "Best Signal Level (dBm)") used as a measure of raw network coverage. EcIo (Pilot Quality Analysis (DL) with "Ec/Io (dB)") to define the service area zone. Overlap (Overlapping Zones (DL) + "Number of Servers") to measure pilot pollution as well as soft handover quality. Best Server Distance 1st-2nd Difference 1st-Nth Difference
ACP handles CDMA2000 similarly to UMTS. The main difference is that the formula for deriving signal level and Ec⁄Io differs between 1xRTT and 1xEv-DO: •
In 1xRTT, formulas are similar to the ones in UMTS, taking into account the pilot power as the basis for signal level computation.
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In 1xEv-DO, the pilot is transmitted at full cell power. The cell max power is thus used as the basis of the signal level computation, as well as the Ec/Io computation.
12.1.2.4 LTE Quality Indicators The quality indicators used by ACP give the same maps and results as the reference prediction in Atoll. In the following list, each quality indicator defined in LTE is followed in italics by the reference prediction in Atoll (with the relevant "Field" setting), if any: • • • • • • • • • • •
Signal Level (Coverage by Signal Level (DL) + "Best Signal Level (dBm)") used as a measure of raw network coverage. RS C (Effective Signal Analysis (DL) + "RS Signal Level (DL) (dBm)") used as a measure of raw network coverage. RS C/N (Effective Signal Analysis (DL) + "RS C/N Level (DL) (dB)") used as a measure of raw network coverage. RSRP (Effective Signal Analysis (DL) + "RSRP Level (DL) (dBm)") used as a measure of raw network coverage. RS CINR (Coverage by C/(I+N) Level (DL) + "RS C/(I+N) Level (DL) (dB)") to measure and control interference. RSRQ (Coverage by C/(I+N) Level (DL) + "RSRQ Level (DL) (dB)") to measure and control interference. RSSI (Coverage by C/(I+N) Level (DL) + "RSSI Level (DL) (dBm)") to measure and control interference. Overlap (Overlapping Zones (DL) + "Number of Servers") to better control cell dominance. Best Server Distance 1st-2nd Difference 1st-Nth Difference
Because RS CINR, RSRQ and RSSI depend strongly on the frequency plan, two methods are currently provided by the ACP: •
•
Using the current frequency plan: The existing frequency plan is taken into account when calculating RS CINR, RSRQ and RSSI. Currently the frequency plan is not dynamically recalculated while changing network parameters. In some cases this may lead to suboptimal reconfiguration, in which case it is recommended to perform one or several ACP -> AFP cycles. Ignoring the current frequency plan and ICIC: All the network cells are assumed to be on the same channel.
12.1.2.5 WiMAX Quality Indicators The quality indicators used by ACP give the same maps and results as the reference prediction in Atoll. In the following list, each quality indicator defined in WiMAX is followed in italics by the reference prediction in Atoll (with the relevant "Field" setting), if any: • • • • • • • •
Signal Level (Coverage by Signal Level (DL) + "Best Signal Level (dBm)") used as a measure of raw network coverage. Preamble C (Effective Signal Analysis (DL) + "Preamble Signal Level (DL) (dBm)") used as a measure of raw network coverage. Preamble C/N (Effective Signal Analysis (DL) + "Preamble C/N Level (DL) (dB)") used as a measure of raw network coverage. Preamble CINR (Effective Signal Analysis (DL) + "Preamble C/(I+N) Level (DL) (dB)") to measure and control interference and signal quality. Overlap (Overlapping Zones (DL) + "Number of Servers") to better control cell dominance. Best Server Distance 1st-2nd Difference 1st-Nth Difference
Because Preamble CINR depends strongly on the frequency plan, two methods are currently provided by the ACP: •
•
Using the current frequency plan: The existing frequency and segmentation plan are taken into account when calculating the CINR. Currently the frequency plan and segmentation plans are not dynamically recalculated while changing network parameters. In some cases this may lead to suboptimal reconfiguration, in which case it is recommended to perform one or several ACP -> AFP cycles. Ignoring the current frequency plan and segmentation: All the network cells are assumed to be on the same channel.
12.1.2.6 Quality Indicator Parameters and Reference Maps The parameters that define how each quality indicator is calculated are under "Parameters" on the Objectives tab, for example which service and terminal to use to define body loss and other losses (terminal antenna gain and loss). Additionally, you can consider shadowing in the calculation. For most quality indicators, you can specify a reference prediction from among the predictions already calculated. By using a reference prediction, you can ensure that the quality indicator will be calculated the same as the reference prediction, enabling comparison of the quality map with the Atoll coverage prediction.
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12.1.2.7 Advanced Objective Configuration By combining several rules to define one objective, you can define more advanced objectives. For example: Example UMTS Overlap > 0 AND UMTS Overlap < 4 (UMTS RSCP > -90dBm AND UMTS EcIo > -12dB) (LTE RS C > -85dBm AND LTE RS CINR > 4dB)
OR
Description Pilot Pollution avoidance (UMTS) Coverage offered by at least one technology
By defining a filter, you can even more advanced objectives by applying the rules only to certain pixels. For example: Example GSM BCCH > -90dBm FOR Pixels where: (UMTS RSCP < -100 AND Overlap < 2
Description Possibility of Inter-technology handover UMTS->GSM
12.1.2.8 Cost Objective Atoll ACP also takes cost objectives into consideration. There are two modes of operation: • •
Cost limit: The total cost of the reconfiguration will not exceed a given maximum cost. Trade-off between quality and cost: The ACP will select the changes which have the most benefit for the least cost.
You can also assign different sets of costs for different site classes. Each site class can be assigned a different set of costs. You can automatically create a set of site classes and their associated costs by defining some options in the [ACPGeneralPage] section of the ACP.ini file. For more information, see the Administrator Manual. Sites are assigned to a site class either manually or automatically. You can assign them automatically by defining a custom field in the Sites table in Atoll and then defining the custom field in the ACP.ini using the "site.costClass" option. [ACPCustomFieldExtraction] site.costClass=SITECLASS # The name of the custom column in SITE table used to define the 'cost class'. # 'cost class' is used to define precisely the cost of changes applied to a site. The site class defined in the custom field in the Sites table will be assigned automatically to each site in the database when a new ACP setup is created. If a new candidate site is created in ACP and is co-located with an existing site, it will inherit the site class of the existing site. If it is not co-located with an existing site, the site class is set to Default and can be changed manually.
12.1.3 Atoll and ACP Prediction Matching ACP coverage predictions try as much as possible to match the Atoll coverage predictions (e.g. ACP’s "EcIo" prediction versus Atoll’s "Pilot Quality Analysis (DL)" prediction). Coverage predictions are therefore similar in most cases, in spite of the variety of potentially conflictuous conditions such as varying resolutions, etc. Generally speaking, the ACP and Atoll coverage predictions will match except in corner cases which are difficult to identify and manage. When there are differences, they will be at pixel level and are negligible (e.g. small map shifts, etc). At the scale of overall maps, they still match pretty well despite small cosmetic mismatches in some very specific corner cases. Hence, potential mismatches between ACP and Atoll core predictions may appear according the following parameter settings: •
Resolution: • The best match between ACP and Atoll coverage predictions is obtained when the ACP resolution matches the path loss resolution. When the resolution of the optimisation is different from the resolution of the path loss matrices, ACP performs a bilinear interpolation by using the four closest path loss values and interpolating. • The most acute match between ACP and Atoll coverage predictions is obtained when the ACP resolution, the path loss resolution, the Atoll prediction resolution, and the raster resolution are identical.
•
Setup Preferences > Calculation setting (on the Preferences tab of the ACP Properties dialog box): • In "High speed" mode, ACP reduces the number of cells it monitors for each pixel, some of which may only create a bit of interference at first, and later create significantly more interference after antenna parameters are changed during optimisation. The "Automatic Candidate Positioning" functionality (New Candidate Setup dialog box > Action button) can be impacted in "High speed" mode.
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In "High precision" mode, ACP increases the number of cells it monitors for each pixel, thereby reducing potential inconsistencies with Atoll coverage predictions (for more information, refer to the "Configuring Default Settings" section in the User Manual).
When the Multi-Storey extension is enabled, the coverage predictions calculated by the ACP may differ slightly from Multi-Storey predictions due to different methodologies used by the ACP and the Atoll platforms. The ACP uses a mix combining a radial method for lower storeys (based on Atoll's "CalculateGrid" API) and a systematic method for upper storeys where few evaluation points are present (using Atoll's "CalculateSubscribers" API).
12.2 Quality Predictions and the Antenna Masking Method Atoll ACP needs to correctly assess how well a reconfigured network will meet quality objectives when performing an antenna reconfiguration such as changing the antenna model, tilt, or azimuth. ACP assesses this change by calculating how the path loss matrices change when the antenna is modified. This process is strongly dependent on the type of propagation model used originally to produce the path loss matrices. Atoll ACP distinguishes between two categories of propagation models: native and non-native. For native propagation models, ACP selects by default the Optimised mode. For non-native propagation models, ACP proposes three different modes: Basic, Improved, and Full Path Loss. The antenna masking method is not used for site selection and antenna height optimisation. These types of reconfiguration are performed by direct path loss calculation. In addition, reconfiguring power is performed by direct scaling of existing path loss matrices and therefore does not use either an antenna masking method or recalculation of the path loss matrices.
12.2.1 Optimised Method The optimised method is used for propagation methods which are native to Atoll: the Standard Propagation Model (SPM), Cost Hata, CrossWave, etc. The ACP performs an un-masking operation with the current antenna pattern, followed by remasking with the new antenna pattern. The optimised method ensures that the ACP prediction correlates strongly with the propagation model calculation. This calculation depends strongly on the horizontal and vertical emission angles between a transmitter and the receiving pixel. The Optimised antenna masking method provides accurate prediction of the emission angles, using one of two internal methods: • •
Direct calculation: ACP calculates incidence angles by direct calculation using the raster data. Delegating to the model: ACP calculates incidence angles by delegating the calculation to the propagation model, providing that the propagation model implements the appropriate methods of Atoll's API
ACP automatically selects which internal method to use for each native propagation model: • •
CrossWave: ACP delegates the calculation to model the propagation model. All others native models: ACP calculates directly. You can define the internal method used by setting the appropriate option in the ACP.ini file. For information on modifying the ACP.ini file, see the Administrator Manual.
12.2.2 Antenna Masking Modes for Non-Native Propagation Models For non-native propagation models, ACP proposes 4 modes: "Basic", "Improved", "Antenna Correction" and "Full Path Loss".
12.2.2.1 Basic Method The Basic method is similar to the Optimised method with direct calculation, but with a few additional parameters. You can set the following parameters for the default method:
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Parameter
Description
Antenna pattern interpolation The antenna gain calculation method for deriving the antenna gain from a set of angles of incidence. Either: • •
Native 3D Interpolation method: The method used by Atoll. For more information on Atoll’s method for 3D interpolation, see the Technical Guide Linear Interpolation method: A simple linear method with a smoothing parameter: G = A hor azi + A ver elev smooth
Direct view
When selected, the angle of incidence will be the direct Tx-Rx angle
Use clutter height
Specify whether clutter heights should be applied along the profiles between transmitter and receiver. Clutter heights are either extracted from the clutter height file, or from default clutter heights based on the clutter class file.
Receiver on top of clutter
Specify whether the receiver should be considered to be on top of the clutter or not.
Operator-specific propagation models can often be modelled correctly using the Basic mode.
12.2.2.2 Improved Method The Improved method performs antenna masking by delegating the calculation of the angles of incidence to the propagation model. If the propagation model does not implement the appropriate methods of Atoll’s API, the Improved method is not available. You can adjust the following parameter when using Improved method: Parameter
Description
Antenna pattern interpolation The antenna gain calculation method for deriving the antenna gain from a set of angles of incidence. Either: • •
Native 3D Interpolation method: The method used by Atoll. For more information on Atoll’s method for 3D interpolation, see the Technical Guide Linear Interpolation method: A simple linear method with a smoothing parameter: G = A hor azi + A ver elev smooth
The Improved method usually gives accurate results.
12.2.2.3 Antenna Correction Method The Antenna Correction method performs antenna masking by delegating both the calculation of the angles of incidence and antenna 3D interpolation to the propagation model. Antenna losses recovered by ACP may include antenna correction and 3D antenna extrapolation. If the propagation model does not implement the appropriate methods of Atoll's API, the Antenna correction method is not available. The selection of antenna pattern interpolation, proposed in an additional parameters column, has no impact with this method as antenna pattern interpolation is calculated by the propagation model and the method used is the propagation model’s embedded method. If available, the Antenna correction method is the recommended one. It usually produces the best results.
12.2.2.4 Full Path Loss Method With the Full Path loss method, the ACP recalculates all path loss matrices for all combinations of parameters which are tested. This is a fall-back method for complex propagation models not accurately modelled by the Basic or Improved methods, for example, for complex ray tracing propagation models. When using the pre-calculated method, Atoll ACP first calculates new path loss matrices for every possible combination of antenna parameters which needs to be tested. The optimisation process then uses these pre-calculated path loss matrices to determine how attenuation changes when an antenna is modified. The ACP does not calculate all path loss matrices for all possible combinations, for example, five possible changes in electrical tilt and five possible changes in azimuth, i.e., 25 path loss matrices. The ACP only calculates the path loss matrices for the changes which need to be evaluated by the optimisation algorithm. By pre-calculating only this subset, the ACP reduces the number of path loss matrices to be calculated and the calculation time. If a change is tested on a transmitter that was not taken into consideration when the path loss matrices were calculated, the ACP recalculates the path loss matrices for that change only.
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The main drawback of the pre-calculated method is the lengthy pre-calculation required and the disk space required to store the path loss matrices. Therefore, the following are recommended: • • •
Use the pre-calculated method only when necessary. If the Basic or Improved method gives accurate ACP predictions that are in line with Atoll, use one of these methods instead. When using the pre-calculated method, limit the number of parameters covered. For example, only enable two or three azimuth options. Also carefully design your antenna groups. Use a path loss storage directory which is dedicated to your project region. This ensures that future optimisations in that region will have path loss matrices that have already been calculated. • •
Power optimisation and site selection (without reconfiguration) do not require recalculation of the path loss matrices. Antenna height reconfiguration as well as new candidates always use a method similar to the Full Path loss method to calculate missing path loss matrices.
12.2.3 CrossWave Propagation Model Atoll ACP supports the CrossWave propagation model as a native model using the Optimised method and delegating the calculation of the angles of incidence to the model. However, the clutter height files and DTM must be accurate in Atoll so that the ACP can access the terrain profile (even when you have configured CrossWave to directly access building vectors).
12.2.4 Antenna Masking and Repeaters, Remote Antennas, and Secondary Antennas ACP fully supports repeaters, cascaded repeaters, and remote antennas. The repeater or remote antenna can be reconfigured for the "coverage side". However the "donor side" of repeaters can not be reconfigured. ACP correctly takes into account the path loss produced by transmitters using secondary antennas.
12.3 Configuration 12.3.1 Configuring an Optimisation Setup Setting up the reconfiguration parameters is straightforward. For each parameter change, a range for the parameter can be specified, for example: • •
Maximum variation for azimuth Minimum/maximum range for electrical tilt, mechanical tilt, power, height, etc.
You have the option of locking height and azimuth optimisation per site. In other words, when a change to antenna height or azimuth is made to one transmitter on a site, the same change is made to all transmitters of a site. In the case of the azimuth, refers to the rotation of the mast, and for antenna height, all antennas will be all displaced to the same height. By default, azimuth locking is disabled, while height locking is enabled by default for all co-localised transmitters on the same site.
12.3.1.1 Antenna Setup Electrical tilt and antenna model optimisation require correct antenna modelling. The concepts on which Atoll ACP antenna modelling are based are the following: • • •
Antenna Element: An antenna element groups all instances of an antenna, belonging to the same frequency band, with different electrical tilts. Physical Antenna: A physical antenna is a multi-band antenna, grouping all antenna elements from different frequency bands which are physically the same antenna. Antenna Groups (Optional): An antenna group is a user-defined subset of the physical antenna enabling you to select antenna model reconfiguration to be done within this subset.
Modelling the antennas normally only needs to be done once. Atoll enables you to carry this out in several different ways: •
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Using the Physical Antenna field of the Antenna table: You can assign the same name in the Physical Antenna field in the Antenna table to antennas belonging to the same physical antenna, independently of the frequency band they use. The ACP will then use this information to automatically create all antenna elements and physical antennas. The physical antenna name is displayed in the "Model" column of the ACP Antenna Pattern Table.
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You can also create a custom column in the Antennas table to automatically link antenna elements of a multi-band physical antenna which have the same electrical tilt. You must identify this column using the "antenna.etilt.share" option in the ACP.ini file. For more information on the ACP.ini file, see the Administrator Manual. This is the preferred method, as ACP will then automatically create all antenna elements and physical antennas each time a setup is created. •
•
Manually defining Antenna Elements and Physical Antennas: You can manually define antenna elements and physical or use a REGEX expression. For more information on manually defining antenna elements and physical antennas, see the User Manual. Detecting automatically the "Freq. Band" field in the ACP "Antenna Pattern Table": • •
If a FREQUENCY custom field exists in Atoll, the value it contains will be extracted. If a FREQUENCY custom field does not exist in Atoll or exists and is less than or equal to 0, then a frequency will be determined in the following order: •
If "antennaPattern" is referenced by a transmitter, the frequency defined by transmitter’s FREQBAND is used. FREQBAND is the "Frequency" field (in GSM) or "Start Frequency" field (in UMTS and LTE) in the Frequency Bands table available from Parameters > Network Settings > Frequencies > Bands.
• •
If the project contains a single FREQBAND, then the frequency defined by this FREQBAND is used If "antennaPattern" defines a [FMIN-FMAX] range, the first FREQBAND defining a frequency within this range is used. Else, the hard-coded value (935, 2110, or 1805) contained in the [FMIN-FMAX] range is used. If all fails, then the value is set to 0 and the cell remains empty.
12.3.1.2 Additional Electrical Tilt (AEDT) Atoll ACP supports additional electrical downtilt (AEDT) processing. AEDT is used when antenna patterns are not available for changes in electrical tilts. The patterns are derived by Atoll ACP using geometric down-tilts of the original antenna pattern. You can enable AEDT support in the ACP by setting the following option in the ACP.ini file: [ACPAntennaPage] enableAedt=1 When you have activated AEDT support, new columns appear in the Antenna Pattern table on the Antenna > Patterns vertical tab to allow you to configure which antenna uses AEDT and the range of allowed electrical tilt. You can use the following ACP.ini options to reference custom columns in the Antennas table. The ACP will use the data entered in these custom fields to set the default values in a new optimisation setup. [ACPCustomFieldExtraction] antenna.aedt.use=ACP_AEDT_USE antenna.etilt.min=ACP_ETILT_MIN antenna.etilt.max=ACP_ETILT_MAX For more information on the available options in the ACP.ini file, see the Administrator Manual.
12.3.1.3 Relative Electrical Tilt Values By default, the ACP allows the reconfiguration of electrical tilt parameters based on absolute values. The same default settings apply to mechanical tilt parameters. The following option allows you to display the electrical tilt values in the Transmitters table (on the Reconfiguration tab) as relative values, rather than absolute ones: [ACPReconfPage] tx.etilt.asRelative=1 The following option can be used to create an additional constraint on the Reconfiguration tab that will be applied to electrical tilt changes. This constraint enables the user to define a range of electrical tilt changes within a defined number of degrees above or below the current electrical tilt. The following example forces the ACP to find an optimal electrical tilt 4 degrees higher than or 4 degrees below the current electrical tilt, for all transmitters. [ACPReconfPage] tx.etilt.deltaLimitConstraint=4
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12.4 Multi-RAT and Co-planning Support The ACP fully supports multi-frequency band, multi-RAT, and co-planning documents.
12.4.1 Multi-RAT and Co-planning Modes When working in co-planning mode with several Atoll documents, ACP enables you to import the other Atoll project into one ACP setup. The ACP setup then becomes a multi-RAT setup. The benefits of using the ACP in multi-RAT mode are: • • •
You can define multi-frequency band/multi-RAT combined objectives You can automatically synchronise shared multi-band antennas. This ensures that any antenna reconfiguration is properly taken into account in all impacted technologies. Shared site location is automatically managed for site location and site candidates. In a multi-RAT document, you can upgrade existing sites with a new radio access technology, and take the upgrade cost into consideration.
The ACP automatically detects sites supporting several technologies, as well as shared multi-band antennas using the Shared Antenna field of the Atoll Transmitters table when present (SHAREDMAST in the database), and provided that co-located transmitters are within a user-definable inter-antenna distance (default = 1m). In addition, the ACP automatically detects colocated sites and antennas, including secondary antennas (i.e. when Shared Antenna is not or is only partially used) using the following algorithm: Parameter
Description
Co-located site
•
User-definable inter-site distance (default = 2m) using the ACP.ini option below: [ACPTplReconfPage] site.min.distance.colocated = 2
Co-located Antenna (i.e. Transmitters)
•
User-definable inter-antenna distance (default=1m) using the ACP.ini option below: [ACPTplReconfPage] tx.min.distance.colocated = 1
•
Antenna height within 1 metre
•
Antenna azimuth within 2 degrees
•
Mechanical tilt within 1 degree Same physical antenna when the antenna defines this field
•
Occasionally, problems in the Atoll database can mean that the ACP does not recognise that sites or antennas are co-located. If this happens, you can manually set the sites or antennas to be co-located, although you should also review the database to correct any errors there.
•
The normal way of detecting linked transmitters is to use the "Shared Antenna" field in the Transmitters table (SHAREDMAST). If at least one transmitter defines a "Shared Antenna", then the following logic is used: •
•
Detection of co-located sites as sites located within a user-definable inter-site distance (default = 2m). All transmitters from co-located sites with the same shared antenna are linked if they have a different frequency band, or if the technology is different. Sanity check is performed to validate that antenna parameters are consistent: same position, same azimuth, same mechanical tilt, and same antenna height (within a user-definable inter-antenna distance [default = 1m] for position, within 2 degrees for azimuth, within 1 degree for tilt, and within 1 metre for antenna height). • When two linked transmitters are not consistent, the ACP will issue a nonblocking warning. • When two transmitters are linked, their values in the Current columns on the Reconfiguration > Transmitters vertical tab are highlighted in red.
If the "Shared Antenna" field is not used by at least one transmitter, then the ACP will use another mode where it automatically detects the linked transmitter using the same criteria as the one used in sanity check (within a user-definable interantenna distance [default = 1m] , within 2 degrees for azimuth, etc.).
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12.4.2 Technology Layer Definition ACP sees each radio access technology as one or several technology layers which are defined according to the following rules: Technology
Technology Layer Definition
Example
GSM
Each independent frequency band is seen as a separate technology layer
• •
GSM 900 GSM 1800
UMTS and CDMA
Each carrier is seen as a separate technology layer
• • •
Carrier 10562 of 2110 MHz band Carrier 10587 of 2110 MHz band Carrier 2937of 925 MHz band
LTE and WiMAX
Each independent frequency band is seen as a separate technology layer
• •
2010 MHz band 900 MHz band
When defining objectives, each rule is associated with a single technology layer. Each quality indicator is evaluated for the technology layer to which it is assigned, however you can group quality indicators from different technology layers within a same objective. When you are using the ACP with more than one technology layer (and, therefore, in multi-RAT projects as well), you can put more emphasis on some technology layers by modifying the global weight of the objectives of each technology layer. ACP optimises the quality objectives for all technology layers. All are considered the same; there is not, for example, one target technology layer and one or more constraint technology layers. If one needs to be optimised without degrading others, you need to: • •
Define a heavier weight on the objectives related to the "target" technology layer, Or use a coverage target for the objectives of the "constraint" technology layers which are relative to the current coverage (where a successful optimisation would be defined as "no coverage decrease").
12.5 Optimisation Methodology When the Atoll ACP performs the optimisation, it optimises all the objectives (quality and cost) combined into a single global score function. This global score function is used as the basis for the search algorithm, i.e., the algorithm attempts to find the best parameter combination to minimise the global score function. In the final step, a sorting algorithm provides an implementation plan where the most useful changes (in terms of minimizing the score) are done first and the least useful changes are done last.
12.5.1 Search Algorithm The possible number of configurations grows exponentially with the number of sectors to optimise. The naive search method, consisting of enumerating all possible solutions, very quickly becomes unmanageable. For example, selecting the best antenna among 10 possible antennas on a 100-sector network, leads to a search space of 10100 possible solutions, i.e., more than the number of atoms in the universe. Atoll ACP uses a Tabu-based search algorithm with fast convergence. In short, this algorithm performs local greedy optimisation, while allowing for the exploration of new locations in the search space. When a transmitter has been allowed a parameter change, any new change is forbidden during a certain number of iterations. A number of additional techniques are used to improve the basic process, such as randomisation, diversification, aspiration, and long-term search. Knowledge of the particular nature of the network (cell neighbour relations, for example) is also used to improve the process and make it efficient. This search algorithm uses the concept of iterations: each iteration consists of one parameter change on one of the sectors or sites of the network. The number of iterations is a key parameter of the optimisation, and should be high enough to ensure that the search space is properly covered. Usually a few times the number of entities to optimise is sufficient, although this parameter still depends strongly on the size of the network and the quality of the initial network. It should be noted that a given sector might be modified in several steps, i.e., the final change might be the result of several different iterations. Some iterations might also cancel each other, i.e., a sector is returned to its initial state at the second iteration.
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The ACP recommends a number of iterations. The recommended number of iterations is calculated by multiplying the number of entities to optimise by two. By defining a number of iterations equal to or greater than the recommended number, you ensure that the search space is explored correctly.
12.5.2 Tuning Algorithm The ACP search algorithm includes a tuning phase between the search and sorting phases (corresponding to optimisation and finalisation phases in the ACP GUI). The tuning phase consists in improving the best solution found during the search phase. It performs a local optimisation of the network while preventing useless changes from being done. During the tuning phase, the ACP proceeds as in the Tabu-based search phase, but without using a Tabu list, randomisation, etc. It simply finds the best neighbour candidate to move after each iteration, i.e. the change which mostly improves the score function STOT(x). The tuning phase stops as soon as the score function (see "Global Score Function" on page 851), can no longer be improved. The tuning phase is fully transparent to the end-user and it provides the following benefits: • • • • •
Removes the changes with insignificant benefits, i.e. changes with less than 1% of the benefit provided by the best single change. Finds the local optima around the best solution of the optimisation phase. Due to the behaviour of the optimisation phase, and to the possibility of early stopping, it can happen that the ACP finds the non-optimal local optima. Allows the Tabu-based search phase to concentrate more on spanning the solution phase, without having to also perform local optimisation around the best candidate solution. Provides a better automatic stop condition for the Tabu-based search phase, and better management of early manual stops by the user. Will be useful in future releases for better management of multiple solution findings corresponding to different qualities or cost trade-offs, i.e. different points on the Pareto surface of multi-objective optimisation problems.
This feature is fully transparent. The requested number of iterations is used in both phases. By default, about 2/3 of the iterations are used in the Tabu-based search phase, and 1/3 in the tuning phase. These ratios can differ when an early stop (automatic or manual) is performed during the Tabu-based search phase. On the Graph tab of the Optimisation window, a vertical bar is displayed to show the switch point between optimisation and tuning phases.
Figure 12.3: Graph tab of the Optimisation window
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12.5.3 Sorting Algorithm After applying the search and tuning algorithms, Atoll ACP proposes a solution consisting of a number of changes to be applied to the initial network. A change is typically a modification to an antenna parameter or (for candidate sites) deploying a site or (for existing sites) sector or removing a site or sector. Atoll ACP then uses a sorting algorithm to create an ordered implementation plan. The sorting algorithm recursively finds the best change to apply among all remaining changes. The best change is the one which improves the total cost function the best: • •
The first changes proposed have more benefits (in terms of the trade-off between quality and cost) than later changes. It is then possible to select a subset of the total number of changes by selecting only the N first changes.
12.5.4 Global Score Function 12.5.4.1 Search Algorithm The global score function used as a basis for the search algorithm is created by a linear combination of the cost objective and every quality objective. The global score function is in the following form:
C TOT x =
ai fi Qi x + k fc C x
i quality obj Where: •
i is an index spanning all quality objectives defined
•
n is the network configuration to be tested
•
Q i x is the "ith" quality objective evaluation
•
a i is a weight factor associated with the "ith" quality objective, and applies different importance on the different
•
quality objectives for the different technology layers. C x is the (financial) cost associated with configuration "x"
•
f i is a one-dimensional function expressing the individual given cost for the "ith" quality objective measurement. The coverage costs are null if the target coverage is reached: f i x = 0 for x T arg etCov
•
f c is a one-dimensional function mapping the network financial cost suitable to be used alongside the quality objective costs.
Example
C TOT x = a obj1 f obj1 Cov obj1 x + a obj2 f obj2 Cov obj2 x Where: Cov obj1 x (or Cov obj2 x ) is the percentage of coverage over a specified threshold for configuration "x". For example, in UMTS:
1 Cov obj1 = --N
i 1 Th E c i Thresh Ec
i pixels
Where: 1 Th is the step function.
1 Cov obj2 = --N
i 1 Th E c I o i Thresh EcIo
i pixels
Where: •
i is the normalised traffic density on pixel "i":
i = 1
i pixels
• •
E c and E c I o are the basic quality measurements on one pixel as described earlier. f obj1 and f obj2 are the one-dimensional mapping functions expressing the individual cost for a coverage figure or network quality:
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f obj1 cov = 0 for cov T arg etRSCP f obj2 cov = 0 for cov T arg etEcIo
12.5.4.2 Tuning Algorithm The global score function used as a basis for the tuning algorithm is the following:
S TOT ( x ) CTOT ( x ) p f n N ( x ) Where: •
x
•
CTOT (x) is the global score function described earlier
•
N (x)
•
p
is the network configuration to be tested
is the number of changes performed in the network from the initial configuration
is a weight factor derived automatically to have an appropriate scaling of the new term with
chosen such that the "cost" of one change is equal to
q%
of the score function improvement provided by the
best individual change in all the proposed changes. By default •
fn
CTOT ( x) . It is
q 1. 25%
is a one-dimensional function expressing an individual cost for a given number of changes. By default, in initial
implementations, it is the identity function:
fn y y
12.5.5 Weighting Several types of weight are applied during the calculation of the global score function. On a geographical level (used to calculate the weights i in the above formulas): • •
Traffic weighting: Each pixel can have an importance proportional to the traffic supported on it. Zone weighting: Each pixel within a defined zone (computation, focus, hot-spot zones or clutter-group zone) can have an additional weight which increases or decreases the importance of the zone.
On a global level (forming the weights a i in the above formulas): •
Quality objective weighting: Within a technology layer, each quality objective can be given more or less importance as compared to other quality objectives of that technology layer.
12.5.6 Controlling the Optimisation Although the Atoll ACP process is designed to be as automatic as possible, there are a couple of parameters that require some consideration: • •
Number of iterations: This option defines the number of iterations in the search algorithm. Resolution: The resolution defines the size of the pixels used to measure the quality objectives.
These parameters affect the quality and speed of the optimisation. If the resolution is high, ACP does a better job of sampling the network zone, but takes longer to run. If the resolution is low, the sampling is more approximate but the speed is highly increased. As a suggestion, Atoll ACP provides information on the total number of pixels, as well as the average number of pixels per site. Similarly, if the number of iterations is high, the optimisation will likely find a better solution but will take longer to run. The following table gives typical values to be used for a good optimisation: Parameter
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Typical Value
Number of iterations
Around 1 to 2 per item (antenna, azimuth, tilt, cell pilot power, etc.) to be optimised
Resolution
The average number of positions per site is between 300 and 3000.
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You can start with a low resolution first, before using a higher resolution for more accurate results. When the ACP is running an optimisation, the tabs of the Optimisation dialogue provide feedback which can help you to decide to stop the optimisation early if the overall network quality seems to have improved enough.
12.5.7 Implementation Plan The sorting process in the implementation plan is based on a global score function which includes quality objectives and the cost of changes (i.e. it takes into account the quality settings as well as the Cost Control settings if cost of changes is considered, with the selection of Maximum Cost or Quality/Cost tradeoff options).
C TOT x =
ai fi Qi x + k fc C x
i quality obj
Figure 12.4: Setup > Properties > Optimisation tab > Cost Control dialog box Only the data displayed on the Change Details tab is actually separated for quality objectives and cost of changes: •
Quality Improvement Ratio %: this column shows the ratio of attained quality VS the maximum quality when all changes are made (the displayed values range from 0% and 100%). This ratio allows you to know the relative gain of each change. It takes into account the coverage and quality objectives (i.e. LTE RS Coverage and LTE RS CINR) and, if used, the financial cost. However, the load balancing objective is not considered.
•
Total Cost: this column shows the associated cost of changes.
The data is separated as it makes more sense to display understandable values in 2 columns rather than display a "Score improvement ratio %" which would be difficult to understand. One consequence of this is that if you obtain 2 changes providing the same quality improvement ratio, then the first one in the list will be the one with the lowest associated cost.
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Figure 12.5: Setup > Optimisation > Properties > Change Details tab
12.5.8 Memory Usage and Optimisation Resolution The administrator can set an option in the ACP.ini file to set a limit on the amount of memory that Atoll ACP can use. If this is the case, you might reach the set limit when using a high resolution and Atoll will stop the ACP optimisation early. If this happens, you can rerun the optimisation by decreasing the resolution or decreasing the size of the computation zone. As well, when performing an optimisation on a large area, you can limit memory usage by performing the optimisation in several steps, each time on a different portion of the entire area. For more information on ACP memory limits, see the Administrator Guide.
12.5.9 Internal Data Management and Performance 12.5.9.1 Memory Usage For each tested network change, the ACP recalculates how each objective improves or degrades. Each objective is the combination of one or several quality indicators evaluated on several hundred thousand or even millions of pixels depending on the resolution and network size. The ACP needs to store, for each pixel, a list of the neighbouring cells in order to be able to find new best servers and calculate interference levels. Given the amount of data processed, it would be prohibitive in terms of the amount of time necessary to read path loss matrices from the disk on each iteration. For each pixel, the ACP keeps the list of neighbour cells and their attribute (path loss attenuation, for example) in memory in a format optimised for fast processing. These internal data structures are created during the loading phase of an ACP run. Any memory issue that could occur when optimising a large network should happen during this initial phase, as allocations to memory are very limited during the solution search. You can change how the ACP manages the data it loads into memory by setting certain options in the ACP.ini file. For example, you can set the number of cells that the ACP monitors by setting the "maxMonitorCell" option in the ACP.ini file. You can use the "threshLevelMonitorCell" option to define the best server signal threshold (dB) of the cell in order for the cell to be monitored. For more information on these options, see the Administrator Guide. In practice, however, it is usually sufficient to change the mode of operation, thereby performing a trade-off between memory usage, and the accuracy of the optimisation (especially on measures related to interference): • • •
High speed: The cell list is shortened to reduce memory use, and the algorithm is optimised to improve speed. Normal: The normal mode with a balanced trade-off between speed, memory use, and accuracy. High precision: The high precision mode results in higher memory usage and a lower speed, but offers the highest accuracy by monitoring a longer list of cells. When doing site selection in Greenfield scenarios where a lot of candidate site are defined close to each other, it is recommended to use the High precision mode in order to ensure that all neighbour candidate sites are well monitored by the ACP.
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12.5.9.2 Disk Space Usage To reduce disk space usage, the user can define in Windows a private storage directory for ACP with compression set to ON. This also holds for the path loss directory. To better use the ACP and avoid lengthy recalculations after rollback changes, specify a Shared directory for path loss matrix storage in the predictions’s Properties dialogue.
12.6 Load Balancing Objective 12.6.1 Principle Used in ACP One obvious approach for load control and balancing within ACP is to compute the new actual cell loads for each tested reconfiguration. By detecting when the cell loads become imbalanced or in excess of given cell resources, it is possible to avoid such reconfiguration. The overall difficulty is the calculation of cell loads given the precise inputs required for traffic, service, etc., (but which are often imperfect in practice), as well as the complex and lengthy calculation involved which would require full Monte Carlo simulations for each tested reconfiguration. Another approach is to consider that the actual cell loads are fixed, i.e. fixing the level of interference generated in the network corresponding to a target load, and then make sure that the supported traffic is maximised and well balanced. This approach avoids the complexity of cell load calculation through complex Monte Carlo simulation, and we believe it is more robust to imperfect inputs. In particular this approach would still provide useful insights on load imbalance from only a partial traffic model (considering for example only 1 or 2 services typically representative of the traffic distribution). This is the approach used in ACP. Since the cell power load is fixed in ACP calculation, another method is needed to insure that the real cell load does not increase beyond capacity and is correctly balanced between cells. The ACP approach is basically to perform cell capacity load balancing. The cell capacity load is not the actual cell load derived from a set of realistic traffic maps and services using a Monte Carlo simulation with power convergence loop, but is only a capacity indicator computed by assuming a fixed cell load and a traffic model which could be simplified model as long as it is representative of the actual traffic distribution. For UMTS R99, the cell capacity load is related to transmitted power: •
•
A total transmitted power is computed over the whole Best Server area by adding transmitted power for each pixel. Each pixel transmitted power is computed by using the load factor equation, but still assuming that the cells have a fixed load for the purpose of interference calculation. Each pixel power is scaled with traffic density distribution. The ratio of this total cell power over the maximum cell power is the cell capacity load, and is expressed in % of the available resources. The ACP equalises the cell capacity load, avoiding that some cells use excessive power.
Other technologies use the same principles, however with a different definition of cell capacity load. The key reason why cell capacity load balancing is a suitable approach is that cell capacity load is correlated to the actual cell load. When the cell capacity loads are being successfully balanced, they tend to converge loosely towards the actual cell load. Any imbalance in the actual cell load is thus reflected by imbalance in the capacity cell load. Moreover, by focusing on a what-if scenario where cell loads are set to an average target load (using for example a target network load of 70%), then the computed capacity cell loads measure directly how much room is available or missing in actual cell capacity to support this target network load.
12.6.2 Optimisation Principle The calculation is performed in 3 steps: • • •
Assignment of the requested traffic to the various cells on the network, across technology layers. Computation of cell capacity load from the assigned traffic. Derivation of the score function of the load balancing objective from the cell capacity loads.
12.6.2.1 Traffic Capture for Load Balancing The ACP is designed to perform load balancing across multiple technology layers. This means that the requested traffic will be shared across the available technology layers within the allowed technologies for this service. The requested traffic for each service is assigned to cells according to the following rules: •
Candidate cells for assignment of a pixel traffic are selected among all best server cells in all different technology layers, and for which:
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The technology layer is allowed for the service. The service traffic capture conditions are fulfilled.
The traffic is assigned partially to each of these candidate cells, such that the cells capacity load is minimal.
The procedure uses a simulation process where the pixel traffic is added gradually to the network, and the cell capacity loads are updated after each assignment, followed by a convergence loop to reach a minimum state. This process basically simulates a network where the traffic is dynamically assigned to technology layers in order to equalise cell loads. For example, if a pixel traffic requested can be assigned to Cell1 from TechnologyLayer1 and to Cell2 from TechnologyLayer2, it will be assigned to the Cell with the minimum cell load. The end result of this process is to distribute the traffic across cells and technology layers in such a way that overlapping cells from different technology layers tend to be equally loaded. For example, in UMTS the cells belonging to same transmitter usually have the same footprint, and as such the computed load will tend to be equal across these cells; for cells which do not fully overlap, the process still tends to equalise technology layer loads as much as possible. In other words, this process simulates a perfect call admission control procedure whose purpose is to perfectly equalise the requested traffic among all cells and technology layers in the network: a new call is always assigned to the technology layer and cell having the minimum load. Technology layers with high capacity (for example LTE vs GSM) tend to acquire more traffic automatically.
12.6.2.2 Cell Capacity Load Calculation The traffic assignment stage basically balance the traffic request across the different cells, while computing the cells capacity loads. The exact method for computing the contribution of a pixel to the cell capacity load is technology-dependent. The cell capacity load is the sum of all pixel contributions, scaled with assigned traffic to the cell’s technology layer:
Li =
T k i k
Pixel k Cell i Where: k is the pixel load ratio and is T k i is the traffic assigned to pixel "k" and cell "i". The unit of capacity load is a percentage (%). In UMTS R99 The load factor equation used is the following:
Eb No Io 1 = ----------- -----------------------P max A tt G proc Where: •
is the pixel load ratio
•
P max is the maximum cell power
•
E b N o is the target EbNo for the given service
•
I o is the total noise and interference
•
A tt is the attenuation towards the cell, including antenna gain and losses
•
G proc is the service processing gain (Gproc = 3.84e6/Tputserv)
In LTE Given the pixel SINR, one derives first the best Bearer which can be assigned to a call originating from that pixel, then derives the maximum possible throughput Tputmax which could be provided to that pixel-originated call (given bandwith, etc). The pixel load ratio is then the ratio of resources used by the service on this pixel, and is given by:
Tput serv = ------------------Tput max Where Tput serv is the average requested throughput for the service
12.6.2.3 Load Balancing Score Function The Load Balancing Score Function being minimised to drive ACP optimisation is the following:
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Score = QI 1 + b 1 – Where: • • •
QI is the Load Quality Index, whose minimisation reduces both the average cell load and load imbalance (explained below with formulas) is the Traffic Captured ratio which measures how much traffic is potentially served in the target zone, due to traffic capture condition being fulfilled b is a scaling factor to give more or less weighting to the traffic captured ratio (default is 1)
This score function will be considered in the ACP global score function when load balancing is activated. This is described in "Impact on the Global Score Function" on page 861.
12.6.2.4 Load Quality Index The Load Quality Index is defined as:
QI = Mean QI l Where: •
QI l = l + a l is the Quality Index computed for technology layer "l"
and: •
l is the weighted average of the cell capacity load
•
l is the weighted standard deviation of the cell capacity load
•
a is a scaling factor to give more or less weighting to the standard deviation, i.e. to the load imbalance (default =1)
1 l = -------------- Wli Li W li Celli Layerl i
1 2 l = -------------- Wli Li – l Wli Celli Layerl i Where W li is a weighting factor applied on each cell load, for technology layer "l", and is used to reduce the effect or completely deselect a cell in the calculation: • •
Cells inside the target zone are considered as having a weight of 1, and cells outside the target zone are allocated a weight of 0. Inactive cells are not considered in the calculation (in term of average/standard deviation values and number of cells).
The overall Load Quality index is an average of the all the technology layers’ Load Quality indexes, i.e. each technology layer gets identical importance.
12.6.2.5 Captured Traffic Ratio The captured traffic ratio is defined as:
T ass = -------T req Where: •
T req is the total traffic requested in the target zone
•
T ass is the total traffic assigned in the target zone
Increasing scaling factor "b" leads to increase the total traffic assigned when the Score function is being minimised. See definition of "b" in "Load Balancing Score Function" on page 856.
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12.6.2.6 Introduction of Load Balancing as a Quality Indicator The Load Quality Index can be rewritten as follows:
l QI l = l 1 + a ---- = l 1 + aD l l Where: •
D l = ----l is the Load Dispersion measure for technology layer "l" l
•
the Load Balance (B) is defined as B = 1 – D l
This load dispersion parameter directly measures the load imbalance. Hence, minimising the Load Quality Index can be seen as a way of decreasing both the Load Dispersion (thus improving the Load Balance) and the Average Load (thus improving the network capacity). A default Load Balance Target value is defined for the Load Balance in the user interface (e.g. 80%). When this target is reached, the Load dispersion part of the Load Quality index is set to null, since the objective is above target. This Load Balance target allows a margin, in other words a low level of imbalance, for example 10% or 20% without further optimisation. Hence, when the Load Balance target is reached, only the average load ( l ) is considered for minimisation in the score function. The minimisation of the Quality index can also be seen as minimisation of the number of overloaded cells. Let's make the assumption that the cell capacity loads are drawn from a Normal random distribution (Gaussian process). It is completely described by both mean and standard deviations. • •
By decreasing the Quality Index with "a = 1", we then decrease the load of the 85th percentile of the distribution. By using "a = 2", the load decrease is for the 98th percentile of the distribution.
Figure 12.6. Cell Load Distribution Percentiles represent the area under the normal curve, increasing from left to right.
As the bottleneck in network capacity for a given quality is often given by its most loaded cells, we directly increase the capacity by focusing on the high distribution percentile. In the most general cases, the cell load distribution is not derived from a Normal distribution, however the argument still holds: decreasing the + a will focus on the capacity network bottleneck.
12.6.3 Quality Figures Used for Graphs and Statistics Results The ACP provides graphs for the Load Balance and the Average Load values, in terms of quality figure for an easy understanding by users. The goal is to provide a percentage value for an improvement and a graph which increases when the quality indicator increases.
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12.6.3.1 Load Balance The figure is designed to show 100% for perfect load balance, and to show 0% for total imbalance. However, the formula used for calculation, B = 1 – --- , must be adapted due to negative values obtained when . Consequently, the formulas used for the Load Balance quality figure are:
LB = 1 – 0.8 --
when
1 LB = --------------------------- 2 1 + 4 ---
when
It is displayed as a curve on the Graphs tab, with initial and final values available on the Statistics tab. Note that the Load balance value will tend to increase (and the graph to go up) when cell capacity loads are better equalised.
12.6.3.2 Average Load The quality figure is given in terms of improvement (%) from the initial average load. The formula used for the quality figure is 0 ----- – 1 Where 0 is the initial value and is the final value, or 0 the value for step N and the value for step N+1. It is displayed as a curve on the Graphs tab and the final improvement can be found on the Statistics tab. In both cases, a 100% improvement means a decrease by 2 of the average load, 200% a decrease by 3, -50% an increase by 2, -75% an increase by 4, etc.
This quality figure will tend to increase when the average load decreases, which is expected during optimisation.
12.6.4 Optimisation Results 12.6.4.1 Load Balancing Tab The Average Load and Load Balance quality figures are shown on the Load Balancing tab for any specified zone. They are based on the cell capacity loads which are displayed on the right on the Load Balancing tab. Hence, from the list of cell capacity loads, it is possible to recompute these quality figures using the formulas described in the previous section. The graph also directly shows the cumulative distribution of cell capacity loads, thus providing the ratio of cell capacity load being smaller than some load value.
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Figure 12.7: Setup > Optimisation > Properties > Load Balancing tab The initial/final load balance values displayed on the Statistics tab and the Load Balancing tab will be identical if: •
The same technology layers are considered: • in the Load Balancing page of the setup properties’ Objectives tab • next to For Technology Layer on the optimisation properties’ Load Balancing tab
•
The same zone is considered: • next to Evaluation Zone on the setup properties’ Optimisation tab • next to For Zone on the optimisation properties’ Load Balancing tab
The values displayed on the Statistics tab are calculated for the cells based on the selected technology layers or hetnet layers and located within the target zone (more precisely for the cells that are actually considered for load balancing). However the capacity load statistics displayed on the Load Balancing tab are calculated based on the technology layers or hetnet layers and the zones that are currently selected in the dialog box. Therefore, the displayed initial/final load balance values can be different on each tab.
12.6.4.2 Graphs The graph representing the Load Balance quality figure shows the progress of this quality figure for each iteration.
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Figure 12.8: Graphs for Quality Figures
Figure 12.9: Statistics results (extract)
12.6.5 Impact on the Global Score Function The Load Balancing Score Function is added to the ACP global score function, which already includes quality objectives and the cost of changes. The weighting of the load balance objective versus other quality objectives (e.g. coverage) can be modified from the user interface (Objectives tab > Load Balancing > Weight parameter). It is calibrated in such a way that X% improvement of the Load quality index is equivalent to an identical improvement on other objectives. For example, 1% improvement of the Load quality index is equivalent to 1% improvement of the RSCP coverage.
12.7 EMF Exposure EMF exposure is defined as the total electromagnetic field measured at a given location. Although the exact limit on the acceptable level of EMF exposure varies by jurisdiction, it is typically a few V⁄m. The ACP can analyse and optimise the EMF exposure in the network in order to reduce excessive electromagnetic radiation in populated areas. Using an internal propagation model specific to EMF exposure, ACP calculates the EMF exposure in two dimensions (for open areas such as parks or roads) or in three dimensions (for buildings). Additionally, with buildings, you can choose to measure the exposure only at the front façade, where the EMF exposure will be the greatest. The internal propagation model evaluates the field strength in V/m using a model based on "free space" propagation, but it can take diffraction into account when required. For regulation requirements, a "worst case" mode can be used for the EMF exposure calculation where EMF predictions are very pessimistic, providing the highest EMF values which would ever likely be seen in the real world. This mode is useful to ensure that an unacceptable level of EMF exposure is never reached in sensitive areas such as schools, hospitals, etc.
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12.7.1 Concepts of ACP EMF Exposure 12.7.1.1 Propagation Classes The internal propagation model calculates EMF exposure using propagation classes which are retrieved from input files. Each propagation class is either opaque, meaning that the signal experiences diffraction losses at the edge of the object but does not go completely through, or transparent, meaning that the signal passes through it (with perhaps some losses) and does not experience diffraction loss. The propagation classes have the following parameters: • • •
Penetration loss (dB): The loss occurring when the signal enters the object. Linear loss (dB/m): A linear loss applied for each meter within an object. The loss is applied only after a given number of meters, specified by the "Linear loss start distance (m)" parameter. Distribution of evaluation points: Field strength measurements are made on a set of points within an object. The measurement points can be distributed in either a 3D pattern or in a 2D pattern. For a two-dimensional distribution, the points can be placed either at the bottom (for example, in a park) or at the top (for example, for a bridge) to better reflect where people will be.
The following default propagation classes are provided: • • •
Open: The Open propagation class is for areas without obstacles, such as an open area or water. An open area can also be an elevated area such as a bridge. Such areas are transparent, with no diffraction loss. Vegetation: The Vegetation propagation class is used for areas covered with vegetation, such as parks. They can be considered as transparent but with a certain degree of diffraction loss. Building: The Building propagation class is used for opaque objects such as buildings. The signal experiences some loss when going through and also suffer from diffraction loss.
It is possible to define new propagation classes, for example to differentiate between similar items with different penetration loss characteristics (for example, glass buildings, stone buildings, wood constructions, etc.) or for differentiating items on which EMF evaluation should be done (for example, habitation versus monuments). Currently, user-defined classes are always of the type "opaque".
12.7.1.2 Terrain Profile To measure EMF exposure, the ACP does not need any specific terrain modelling, but instead it uses all the geo data available in the Atoll project: •
•
Geo raster data: Raster data give a grid-based representation of the terrain with a defined resolution. The raster files needed are DTM (Digital Terrain Model) representing the ground altitude, clutter classes representing the type of terrain and clutter heights (also called a digital height model) representing individual heights (for example, building heights). Geo vector data: Geo vector data model the buildings and their height, in the form of one or several ArcView SHP files defining numerous polygons.
ACP uses the geo data to create a 3D representation of the terrain in the form of a fine raster of pixels with a default resolution of 2 meters. For each pixel in this raster representation, both the height and propagation class information are encoded: • •
For geo vectors, each polygon is associated with a single propagation class and a height. If a geo vector contains more than one polygon, ACP uses the associated DBF file to map the polygons to propagation classes and heights. For geo rasters, each clutter class is associated with a single propagation class. The height is obtained from the clutter height raster file. If no clutter height file is present, the default clutter class height is used.
For areas covered both by vector data and raster data, only the geo vector data are used. Geo raster data are only used for the areas not covered by geo vector data. It is recommended to always provide either geo vector data or clutter heights raster data to have the most accurate EMF exposure prediction.
12.7.1.3 Distribution of Evaluation Points ACP uses the internal terrain representation to specify where to set evaluation points for EMF exposure evaluation. It is possible to distribute evaluation points separately on each propagation class and for each terrain entry. For example, you can distribute evaluation points on one geo vector entry for one subset of polygons, but not on another vector entry. Similarly you distribute evaluation points on only selected clutter classes.
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Evaluation points are distributed either in a 2D or 3D pattern depending on the propagation class: • • •
Open: For the Open class (e.g., bridges, roads, open spaces, etc.) evaluation points are distributed in 2D on the top of the class height. Vegetation: For the Vegetation class (e.g., parks, forests, etc.) evaluation points are distributed in 2D at the bottom of the class height. Building: For the Building class evaluation points are distributed in 3D. In this case it is also possible to specify the maximum indoor distance on which to measure EMF exposure, and or to restrict the prediction on the building front façade.
12.7.1.4 The Contribution of Transmitter Power to EMF Exposure The ACP takes the maximum power transmission on all the carriers and channels used by transmitters in the network into consideration in its calculations. This ensures that all provided results are for a fully loaded network, thereby giving a worst case calculation of EMF exposure. The ACP also takes into consideration the antenna radiation pattern by creating a 3D interpolation from the 2D horizontal and vertical cross-sections of the antenna radiation pattern. The method is similar to the one used elsewhere in Atoll.
12.7.1.5 Worst-case Mode The ACP allows you to consider a worst case scenario, where any opaque propagation class such as Building becomes fully transparent to electromagnetic waves. The EMF exposure is therefore evaluated as if the area was completely free space. This mode gives you a pessimistic view of the actual exposure since, in the real world, penetration loss through obstacles as well as diffraction and reflection around obstacles tends to strongly decrease the signal strength compared to a completely free space model. This mode is useful when optimising the networks while ensuring that regulatory limits are never exceeded.
12.7.2 General Workflow ACP creates a representation of the terrain in 3D. It then distributes a number of evaluation points in this representation according to the parameters set in the setup. ACP evaluates EMF exposure on each of these evaluation points using an integrated propagation model specially tailored for the evaluation of strong signals in the vicinity of the antennas. This modelling is based on free space formulas which are applicable starting at a few meters from the antennas up to a few hundred meters. It takes into account the antenna gain and attenuation patterns towards each evaluation point, as well as some diffraction and indoor losses. The overall EMF exposure calculation is obtained by adding the electromagnetic signal level generated by each technology involved (GSM, UMTS, CDMA, LTE, WiMAX) and considering all carriers and channels used. To predict the overall EMF exposure, ACP calculates the quadratic sum of all channels in all multi-RAT technologies: E =
2
2
E GSM + E UMTS + E LTE
2
The following parameters are used in the calculation: o
BcchPower
•
GSM:
N
•
UMTS:
MaxPowerCelli
TRX
ACP takes into account the maximum transmission powers of cells or transmitters to simulate "worst case" scenarios. Hence, the following conditions must be met for the most reliable results: • •
GSM: the number of TRXs must be correctly referenced in the Atoll database, and UMTS and LTE: all the cells which are to be considered must be present and activated in the Atoll database. It is highly recommended to activate all technology layers. In UMTS, even if only one technology layer is activated in the ACP interface for a given frequency band, the other carriers will also be included in the calculation.
12.7.3 EMF Exposure Calculation The calculation of EMF exposure is based on the following formula giving the electromagnetic E field (in Volt/meter) at distance d , in free space far field:
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30 EIRP E = ---------------------d Where EIRP = P tx G tx and P tx is the transmitted power in Watts and G tx is the antenna gain. Reason for Using the Free Space Far Field Model In the free space far field model, the plane wave power density is given (in Watts per square meter) by:
P
WM
2
P tx G tx = -------------2 4d
The power received by a theoretical ideal antenna with an effective aperture of A er and a gain of G rx is given by the Friis transmission formula for wavelength :
P rx = P
Wm
2
A er
2
Where
A = ------ G rx 4
By combining the Friis formula with the expression of E previously defined, the relationship between the EMF exposure level (in dBV⁄m) and the received signal power level (in dBm) when considering a receiving antenna with 0 dB gain at frequency F (in MHz) is:
P rx dBm = E dB V m + 42.8 – 20log 10 F MHz For frequencies around 1 GHz, the significant EMF exposure level (> 0.1 V⁄m) corresponds to a received signal level greater than -37 dBm. Propagation models designed for coverage analysis typically deal with signal levels usually lower than -40 dBm. They model complex phenomena such as diffraction, reflection, multipath transmission, etc., either deterministically (ray tracing) or empirically. For example, urban empirical models such as Cost-Hata models are typically an extension of the Friis formula where the 2
n
distance denominator 1 d is replaced with 1 d , with n being a value from 3 to 5. In addition they only measure the signal level in a 2D horizontal plane, and not in 3D horizontal and vertical planes. ACP uses a simple propagation model dedicated to cope with the requirements of EMF exposure evaluation. This model is based on the free space far field formula since "line of sight" exposure can cause significant EMF exposure, resulting in a potential health hazard (when exposure is above a few tenths of V/m). In non-line of sight situations or far away from the base station (i.e., beyond a few hundred meters), distance, diffraction, and reflection phenomena decrease the signal strength very rapidly. The signal strength then becomes smaller than the range of interest (a few tenths of V/m). The Far-field Restriction The far field area is usually defined by the area beyond a distance related to antenna size D :
d far – field = 2 When the largest dimension D of the antenna is less than the wave length ( ). 2
d far – field = 2D When the largest dimension D of the antenna is greater than the wave length ( ). The far field starts at around 10 to 20 meters from the antenna. However, the far field formula usually leads to good field estimates starting at a distance of around 5 meters from the antenna. This is in part because antennas are formed of several stacked dipoles (for example 8 to 10) with low coupling between them. In practice, the total EM signal can be obtained by adding the signal generated by each dipole, each one having a far field starting at a distance of 2 (or less than 1 meter for a typical frequency of interest).
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12.8 Shadowing Margin and Indoor Coverage Atoll ACP supports both indoor coverage and a shadowing margin. When indoor coverage is used, an additional indoor loss is added to all pixels marked as being indoors. This indoor loss is clutter-dependent. By default, all pixels are considered as being indoors, but it is possible to specify which clutter classes should be considered as indoors. When the shadowing margin has been enabled, a shadowing margin is added to the basic quality measurement. This margin usually depends on: • •
Cell coverage probability, according to the log normal distribution function. The model standard deviation which is clutter-dependent and defined separately for different quality measures.
The shadowing margin is applied in the same way as it is in Atoll coverage predictions, for example, in calculating the macrodiversity gain in UMTS.
12.9 Multi-Storey Optimisation The ACP includes a multi-storey extension where evaluation points are distributed on all floors of buildings defined in a clutter heights map. This enables the ACP to take all floors of the building into account during optimisation. The ACP then proceeds with its optimisation algorithm as usual. All 3-D points participate in the objective optimisation.
12.9.1 Path Loss Calculation and Data Caching The ACP multi-storey extension calculates the path losses from each transmitter to the points distributed in three dimensions by calling certain methods of Atoll's API on the propagation model (CalculateSubscriber and CalculateGrid). The ACP first detects if path loss matrices created by the Atoll MultiStorey Add-in are present, and in that case reuses them if possible. If matrices are not present, it recalculates path loss matrices itself for different heights. If the number of points distributed for a given height is low, then the ACP uses a point-to-point calculation instead of full path loss matrices (i.e., it uses API CalculateSubscriber instead of CalculateGrid). The ACP stores the path loss attenuation to the multi-storey evaluation points in the ACP storage directory. On further ACP runs, there is usually little or no need for path loss recalculation, even after modifying parameters such as resolution, etc. The ACP then calculates the angles of incidence which are used for the antenna masking method. The calculation method depends on the propagation model: • •
Direct calculation at the required height when not using "delegation to the propagation model" Angle estimation from the original angle of incidence calculated at ground level and taking into account geometrical considerations, when using "delegation to the propagation model" (for example, when using a propagation model such as Crosswave).
12.9.2 Pixel Weighting The total weight associated with an x/y pixel (derived from traffic and zone weighting) is either shared equally among all vertical evaluation points present at this pixel, or multiplied by the number of vertical points at that pixel. For example, if a pixel presents a weight of 1 and a total of 5 points at that location (one point at ground level and four additional points, one every 10 meters), each point either takes a weight of 0.2 (when vertical weight sharing is selected) or 1 (when vertical weight sharing is not selected).
12.9.3 Results All statistical results provided take into account both 2-D and 3-D points, through the weighting process described earlier. However all predictions provided by the ACP relate only to the ground layer by default. Viewing detailed results for 3-D points is done by creating Quality Analysis and Objective Analysis predictions in the ACP. A new tab is available in the properties of the prediction to show results at different heights. Three options are provided: • • •
Display at ground level (defined receiver height): Only the prediction values seen at the ground pixels are shown. Display min. values seen at a given position: When several points are present for a pixel (1 ground level point + one or several multi-storey points at different heights), the minimum value of those points is shown. Display values at given storey: Only the points at the given storey are displayed
Example:
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Signal Level at 3rd storey
12.9.4 Notes •
ACP distributes multi-storey evaluation points only where clutter heights are present. By default, no point is created using the default clutter class height when only a clutter class file is present. To enable taking the default clutter class height into account, you can define the following option in the ACP.INI file: [ACPCore] multistorey.onlyDHM=true
•
•
The actual heights used for multi-storey evaluation depend on the receiver height defined in Atoll. If a receiver height of 1.5 m is used, and a vertical step of 2 storeys (with a storey defined in this example as being 3 m), then the actual heights are 1.5m, 7.5m, 13.5m, etc. This is the same as the process used by the Multi-storey Prediction add-in. Predictions calculated by the ACP might differ slightly from multi-storey predictions due to different methodologies used by the two tools: • •
The ACP uses a mix of a radial method (CalculateGrid) for lower storeys, and a systematic method (CalculateSubscribers) for the upper storey where few evaluation points are present. Atoll uses in general a "radial" method.
12.9.5 Concepts of ACP EMF Exposure 12.9.5.1 Propagation Classes The internal propagation model calculates EMF exposure using propagation classes which are retrieved from input files. Each propagation class is either opaque, meaning that the signal experiences diffraction losses at the edge of the object but does not go completely through, or transparent, meaning that the signal passes through it (with perhaps some losses) and does not experience diffraction loss. The propagation classes have the following parameters: • • •
Penetration loss (dB): The loss occurring when the signal enters the object. Linear loss (dB/m): A linear loss applied for each meter within an object. The loss is applied only after a given number of meters, specified by the "Linear loss start distance (m)" parameter. Distribution of evaluation points: Field strength measurements are made on a set of points within an object. The measurement points can be distributed in either a 3D pattern or in a 2D pattern. For a two-dimensional distribution, the points can be placed either at the bottom (for example, in a park) or at the top (for example, for a bridge) to better reflect where people will be.
The following default propagation classes are provided: • • •
Open: The Open propagation class is for areas without obstacles, such as an open area or water. An open area can also be an elevated area such as a bridge. Such areas are transparent, with no diffraction loss. Vegetation: The Vegetation propagation class is used for areas covered with vegetation, such as parks. They can be considered as transparent but with a certain degree of diffraction loss. Building: The Building propagation class is used for opaque objects such as buildings. The signal experiences some loss when going through and also suffer from diffraction loss.
It is possible to define new propagation classes, for example to differentiate between similar items with different penetration loss characteristics (for example, glass buildings, stone buildings, wood constructions, etc.) or for differentiating items on which EMF evaluation should be done (for example, habitation versus monuments). Currently, user-defined classes are always of the type "opaque".
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12.9.5.2 Terrain Profile To measure EMF exposure, the ACP does not need any specific terrain modelling, but instead it uses all the geo data available in the Atoll project: •
•
Geo raster data: Raster data give a grid-based representation of the terrain with a defined resolution. The raster files needed are DTM (Digital Terrain Model) representing the ground altitude, clutter classes representing the type of terrain and clutter heights (also called a digital height model) representing individual heights (for example, building heights). Geo vector data: Geo vector data model the buildings and their height, in the form of one or several ArcView SHP files defining numerous polygons.
ACP uses the geo data to create a 3D representation of the terrain in the form of a fine raster of pixels with a default resolution of 2 meters. For each pixel in this raster representation, both the height and propagation class information are encoded: • •
For geo vectors, each polygon is associated with a single propagation class and a height. If a geo vector contains more than one polygon, ACP uses the associated DBF file to map the polygons to propagation classes and heights. For geo rasters, each clutter class is associated with a single propagation class. The height is obtained from the clutter height raster file. If no clutter height file is present, the default clutter class height is used.
For areas covered both by vector data and raster data, only the geo vector data are used. Geo raster data are only used for the areas not covered by geo vector data. It is recommended to always provide either geo vector data or clutter heights raster data to have the most accurate EMF exposure prediction.
12.9.5.3 Distribution of Evaluation Points ACP uses the internal terrain representation to specify where to set evaluation points for EMF exposure evaluation. It is possible to distribute evaluation points separately on each propagation class and for each terrain entry. For example, you can distribute evaluation points on one geo vector entry for one subset of polygons, but not on another vector entry. Similarly you distribute evaluation points on only selected clutter classes. Evaluation points are distributed either in a 2D or 3D pattern depending on the propagation class: • • •
Open: For the Open class (e.g., bridges, roads, open spaces, etc.) evaluation points are distributed in 2D on the top of the class height. Vegetation: For the Vegetation class (e.g., parks, forests, etc.) evaluation points are distributed in 2D at the bottom of the class height. Building: For the Building class evaluation points are distributed in 3D. In this case it is also possible to specify the maximum indoor distance on which to measure EMF exposure, and or to restrict the prediction on the building front façade.
12.9.5.4 The Contribution of Transmitter Power to EMF Exposure The ACP takes the maximum power transmission on all the carriers and channels used by transmitters in the network into consideration in its calculations. This ensures that all provided results are for a fully loaded network, thereby giving a worst case calculation of EMF exposure. The ACP also takes into consideration the antenna radiation pattern by creating a 3D interpolation from the 2D horizontal and vertical cross-sections of the antenna radiation pattern. The method is similar to the one used elsewhere in Atoll.
12.9.5.5 Worst-case Mode The ACP allows you to consider a worst case scenario, where any opaque propagation class such as Building becomes fully transparent to electromagnetic waves. The EMF exposure is therefore evaluated as if the area was completely free space. This mode gives you a pessimistic view of the actual exposure since, in the real world, penetration loss through obstacles as well as diffraction and reflection around obstacles tends to strongly decrease the signal strength compared to a completely free space model. This mode is useful when optimising the networks while ensuring that regulatory limits are never exceeded.
12.9.6 General Workflow ACP creates a representation of the terrain in 3D. It then distributes a number of evaluation points in this representation according to the parameters set in the setup.
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ACP evaluates EMF exposure on each of these evaluation points using an integrated propagation model specially tailored for the evaluation of strong signals in the vicinity of the antennas. This modelling is based on free space formulas which are applicable starting at a few meters from the antennas up to a few hundred meters. It takes into account the antenna gain and attenuation patterns towards each evaluation point, as well as some diffraction and indoor losses. The overall EMF exposure calculation is obtained by adding the electromagnetic signal level generated by each technology involved (GSM, UMTS, CDMA, LTE, WiMAX) and considering all carriers and channels used.
12.10 ACP Software Data Flow Understanding the Atoll ACP software data flow will help understand how the module works and some of its internal constraints. Here are some of the concepts related to the data flow: •
•
• •
•
Data Model Extraction: When first run (i.e., when the user selects New from the ACP - Automatic Cell Planning context menu), the ACP extracts all relevant information from the current Atoll project and builds its internal data model. This data model is saved in a "Setup" node and enables each optimisation setup to be reviewed or replayed later. The data model also contains information identifying the version used to generate it, meaning that the results produced by a previous release can in general be reloaded or replayed. Data Model Content: The data model includes all necessary data from the Atoll database; essentially all antennas, transmitters, sites, cells, and service definitions. The data model does not include raster information such as clutter, DEM, DHM maps, nor does it contain the path losses matrices. The raster data and path loss matrices are accessed directly by the core optimisation engine during ACP calculations. Setup: The ACP Setup dialogue allows you to view and modify the optimisation parameters. The data model is not accessible using the Setup dialogue. Results: After an optimisation run, Atoll ACP produces a result model which is found under the original setup in an Optimisation node. Using the Optimisation node, you can view the results and generate analysis maps that can be displayed directly in the Atoll map window. You can also commit the set of recommended changes directly into the Atoll database. Optimisation Engine: The optimisation engine is the core algorithm that performs the optimisation on a defined setup. It works using the extracted internal data model in the Setup node, but also uses direct access to raster and path loss information.
Because Atoll ACP uses this internal data model, it is important to understand that: •
•
•
An optimisation runs on the data model stored in the setup node. If changes are introduced into the Atoll database later (such as changes to the antennas, cells, site, etc.), these changes are not taken into account in any existing setup node. The network configuration is essentially frozen in the setup node in the state it was in when the setup was created. A new setup needs to be created in order for the changes to be taken into account. Because the path loss information is not stored in the setup node, but is instead accessed directly by the core optimisation engine, it can happen that there is a mismatch between stored path loss matrices and the data model in the setup node (for example, after modifying transmitters directly in Atoll). The ACP manages cases of data mismatch by using the concept of a locked setup node. No optimisation can be run on a locked setup node unless the path loss information is consistent with the internal data model of the setup. Setup nodes are automatically unlocked when the path loss information and the internal data model once again match.
This behaviour is particularly true when new settings produced by an optimisation run are committed to Atoll. The setup node is locked after a commit. It will be unlocked if the Atoll project is rolled back to its initial state. •
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