Atoll 2.8.3 RF Technical Reference Guide E2

Technical Reference Guide

v e r s i o n 2.8.3

AT283_TRG_E2

Technical Reference Guide

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Atoll 2.8.2 Technical Reference Guide Release AT283_TRG_E2

© Copyright 1997 - 2010 by Forsk The software described in this document is provided under a licence agreement. The software may only be used/copied under the terms and conditions of the licence agreement. No part of this document may be copied, reproduced or distributed in any form without prior authorisation from Forsk. The product or brand names mentioned in this document are trademarks or registered trademarks of their respective registering parties.

About the Technical Reference Guide This document is targeted at readers with a prior knowledge of Atoll, its operation and basic functioning. It is not the User Manual for Atoll, and does not teach how to operate and use Atoll. It is a supplementary document containing detailed descriptions of models, algorithms and concepts adopted in Atoll. Therefore, it concerns only the appropriate personnel. The Atoll Technical Reference Guide is divided into three parts with each part comprising similar topics. The first part contains descriptions of general terms, entities, ideas and concepts in Atoll that are encountered throughout its use. It is followed by the second part that consists of descriptions of entities common to all types of networks and the algorithms that are technology independent and are available in any network type. Lastly, the guide provides detailed descriptions of each basic type of network that can be modelled and studied in Atoll.

© Forsk 2010

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Table of Contents

Table of Contents

1 1.1 1.1.1 1.1.1.1 1.1.1.2 1.1.1.3 1.1.1.4 1.1.1.5 1.1.1.6 1.1.2 1.1.2.1 1.1.2.2 1.1.2.3 1.1.3 1.1.3.1 1.1.3.2 1.1.3.3 1.1.3.4 1.1.3.5 1.1.4 1.2 1.2.1 1.2.2 1.3

2 2.1 2.1.1 2.1.1.1 2.1.1.2 2.1.1.2.1 2.1.1.2.2 2.1.1.3 2.1.1.3.1 2.1.1.3.2 2.1.1.3.3 2.1.1.3.4 2.1.1.4 2.1.1.5 2.1.1.6 2.1.1.7 2.1.2 2.2 2.2.1 2.2.2 2.2.3 2.2.4 2.2.5 2.2.6 2.2.7 2.2.8 2.2.8.1 2.2.8.2 2.2.8.3 2.2.9 2.2.9.1

© Forsk 2010

Coordinate Systems and Units ....................................................... 23 Coordinate Systems............................................................................................................................... 23 Description of Coordinate Systems .................................................................................................. 23 Geographic Coordinate System.................................................................................................. 23 Datum ......................................................................................................................................... 23 Meridian ...................................................................................................................................... 23 Ellipsoid ...................................................................................................................................... 23 Projection.................................................................................................................................... 24 Projection Coordinate System .................................................................................................... 24 Coordinate Systems in Atoll ............................................................................................................. 24 Projection Coordinate System .................................................................................................... 24 Display Coordinate System ........................................................................................................ 24 Internal Coordinate Systems ...................................................................................................... 24 File Formats ..................................................................................................................................... 25 Unit Codes .................................................................................................................................. 25 Datum Codes.............................................................................................................................. 26 Projection Method Codes ........................................................................................................... 27 Ellipsoid Codes ........................................................................................................................... 27 Projection Parameter Indices...................................................................................................... 28 Creating a Coordinate System ......................................................................................................... 28 Units ....................................................................................................................................................... 28 Power Units ...................................................................................................................................... 28 Length Units ..................................................................................................................................... 29 BSIC Format .......................................................................................................................................... 29

Geographic and Radio Data ........................................................... 33 Geographic Data .................................................................................................................................... 33 Data Type......................................................................................................................................... 33 Digital Terrain Model (DTM) ....................................................................................................... 33 Clutter (Land Use) ...................................................................................................................... 34 Clutter Classes...................................................................................................................... 34 Clutter Heights ...................................................................................................................... 34 Traffic Data ................................................................................................................................. 34 User Profile Environment Based Traffic Maps ...................................................................... 34 User Profile Traffic Maps....................................................................................................... 34 Sector Traffic Maps ............................................................................................................... 34 User Density Traffic Maps..................................................................................................... 35 Vector Data................................................................................................................................. 35 Scanned Images......................................................................................................................... 35 Population................................................................................................................................... 35 Other Geographic Data............................................................................................................... 35 Supported Geographic Data Formats .............................................................................................. 35 Radio Data ............................................................................................................................................. 36 Site ................................................................................................................................................... 36 Antenna ............................................................................................................................................ 36 Transmitter ....................................................................................................................................... 36 Repeater........................................................................................................................................... 36 Remote Antenna .............................................................................................................................. 37 Station .............................................................................................................................................. 37 Hexagonal Design ............................................................................................................................ 37 GSM GPRS EGPRS Documents ..................................................................................................... 37 TRX............................................................................................................................................. 37 Subcell ........................................................................................................................................ 37 Cell Type..................................................................................................................................... 37 All CDMA, WiMAX, and LTE Documents ......................................................................................... 37 Cell.............................................................................................................................................. 37

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3 3.1 3.1.1 3.1.1.1 3.1.1.2 3.1.1.2.1 3.1.1.2.2 3.1.1.2.3 3.2 3.2.1 3.2.2 3.2.2.1 3.3 3.3.1 3.3.1.1 3.3.1.2 3.3.1.2.1 3.3.2 3.3.3 3.3.3.1 3.4 3.4.1 3.5 3.5.1 3.5.2 3.5.2.1 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.13.1 3.13.2 3.14 3.15 3.15.1 3.15.1.1 3.15.1.2 3.15.2 3.15.2.1 3.15.2.2 3.15.3 3.15.3.1 3.15.3.2 3.15.4 3.15.5 3.16 3.16.1 3.16.2 3.17 3.17.1 3.17.2 3.18 3.18.1 3.18.1.1 3.18.1.1.1 3.18.1.1.2 3.18.1.1.3 3.18.1.2 3.18.2 3.19 3.19.1 3.19.1.1 3.19.1.1.1

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File Formats.....................................................................................41 BIL Format ..............................................................................................................................................41 HDR Header File...............................................................................................................................41 Description ..................................................................................................................................41 Samples ......................................................................................................................................42 Digital Terrain Model..............................................................................................................42 Clutter Classes File................................................................................................................42 BIL File...................................................................................................................................42 TIF Format start here..............................................................................................................................42 TFW Header File...............................................................................................................................43 Sample ..............................................................................................................................................44 Clutter Classes File .....................................................................................................................44 BMP Format............................................................................................................................................44 BMP File Description.........................................................................................................................44 BMP File Structure ......................................................................................................................44 BMP Raster Data Encoding ........................................................................................................45 Raster Data Compression Descriptions.................................................................................46 BPW/BMW Header File Description..................................................................................................47 Sample ..............................................................................................................................................47 Clutter Classes File .....................................................................................................................47 PNG Format............................................................................................................................................47 PGW Header File Description ...........................................................................................................47 Generic Raster Header File (.wld) ..........................................................................................................47 WLD File Description ........................................................................................................................48 Sample ..............................................................................................................................................48 Clutter Classes File .....................................................................................................................48 DXF Format ............................................................................................................................................48 SHP Format ............................................................................................................................................48 MIF Format .............................................................................................................................................48 TAB Format ............................................................................................................................................49 ECW Format ...........................................................................................................................................49 Erdas Imagine Format ............................................................................................................................50 Planet EV/Vertical Mapper Geographic Data Format .............................................................................50 ArcView Grid Format ..............................................................................................................................50 ArcView Grid File Description ...........................................................................................................50 Sample ..............................................................................................................................................51 Other Supported Geographic Data File Formats ....................................................................................51 Planet Format .........................................................................................................................................51 DTM File............................................................................................................................................51 Description ..................................................................................................................................51 Sample ........................................................................................................................................52 Clutter Class Files .............................................................................................................................52 Description ..................................................................................................................................52 Sample ........................................................................................................................................52 Vector Files .......................................................................................................................................53 Description ..................................................................................................................................53 Sample ........................................................................................................................................53 Image Files........................................................................................................................................53 Text Data Files ..................................................................................................................................54 MNU Format ...........................................................................................................................................54 Description ........................................................................................................................................54 Sample ..............................................................................................................................................54 XML Table Export/Import Format ...........................................................................................................55 Index.xml File ....................................................................................................................................55 XML File ............................................................................................................................................55 Externalised Propagation Results Format ..............................................................................................57 DBF File ............................................................................................................................................57 DBF File Format ..........................................................................................................................57 DBF Structure ........................................................................................................................57 DBF Header (Variable Size - Depends on Field Count) ........................................................57 Each DBF Record (Fixed Length)..........................................................................................59 DBF File Content.........................................................................................................................59 LOS File ............................................................................................................................................60 Externalised Tuning Files .......................................................................................................................60 DBF File ............................................................................................................................................60 DBF File Format ..........................................................................................................................60 DBF Structure ........................................................................................................................60

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Table of Contents

3.19.1.1.2 3.19.1.1.3 3.19.1.2 3.19.2 3.20 3.20.1 3.20.1.1 3.20.2 3.20.2.1 3.20.2.1.1 3.20.2.1.2 3.20.2.2 3.20.2.2.1 3.20.2.2.2 3.20.3 3.20.3.1 3.20.4 3.20.4.1 3.21 3.21.1 3.21.2

4 4.1 4.2 4.2.1 4.2.1.1 4.2.2 4.2.2.1 4.2.2.2 4.2.3 4.3 4.3.1 4.3.2 4.3.2.1 4.3.2.2 4.3.3 4.3.3.1 4.3.3.1.1 4.3.3.1.2 4.3.3.2 4.4 4.4.1 4.4.2 4.4.3 4.4.3.1 4.4.3.2 4.5 4.5.1 4.5.1.1 4.5.1.2 4.5.1.3 4.5.2 4.5.2.1 4.5.2.2 4.5.2.2.1 4.5.2.2.2 4.5.2.2.3 4.5.2.3 4.5.3 4.5.3.1 4.5.3.2 4.5.3.2.1 4.5.3.2.2 4.5.3.2.3 4.5.3.2.4 4.5.3.2.5 4.5.3.2.6 © Forsk 2010

DBF Header (Variable Size - Depends on Field Count)........................................................ 60 Each DBF Record (Fixed Length) ......................................................................................... 62 DBF File Content ........................................................................................................................ 62 PTS File............................................................................................................................................ 62 Interference Histograms File Formats.................................................................................................... 63 One Histogram per Line (.im0) Format............................................................................................. 63 Sample........................................................................................................................................ 63 One Value per Line with Dictionary File (.clc) Format ...................................................................... 64 CLC File...................................................................................................................................... 64 Description ............................................................................................................................ 64 Sample .................................................................................................................................. 65 DCT File...................................................................................................................................... 66 Description ............................................................................................................................ 66 Sample .................................................................................................................................. 66 One Value per Line (Transmitter Name Repeated) (.im1) Format ................................................... 67 Sample........................................................................................................................................ 67 Only Co-Channel and Adjacent Values (.im2) Format ..................................................................... 68 Sample........................................................................................................................................ 68 Antenna Pattern Formats ....................................................................................................................... 69 2D Antenna Diagram Format ........................................................................................................... 69 Import Format of Text Files Containing 3D Antenna Patterns.......................................................... 70

Calculations .................................................................................... 73 Overview ................................................................................................................................................ 73 Path Loss Matrices................................................................................................................................. 74 Calculation Area Determination........................................................................................................ 75 Computation Zone ...................................................................................................................... 75 Calculate / Force Calculation Comparison ....................................................................................... 75 Calculate..................................................................................................................................... 75 Force Calculation........................................................................................................................ 76 Matrix Validity ................................................................................................................................... 76 Path Loss Calculations........................................................................................................................... 77 Ground Altitude Determination ......................................................................................................... 77 Clutter Determination ....................................................................................................................... 77 Clutter Class ............................................................................................................................... 78 Clutter Height.............................................................................................................................. 78 Geographic Profile Extraction........................................................................................................... 78 Extraction Methods ..................................................................................................................... 78 Radial Extraction ................................................................................................................... 78 Systematic Extraction ........................................................................................................... 79 Profile Resolution: Multi-Resolution Management...................................................................... 80 Coverage Predictions............................................................................................................................. 81 Use of Polygonal Zones in Coverage Prediction Reports ................................................................ 81 Filtering Coverage Prediction Exports .............................................................................................. 81 Smoothing Coverage Prediction Exports ......................................................................................... 81 Smoothing: Percentage Method ................................................................................................. 81 Smoothing: Number of points method ........................................................................................ 82 Propagation Models ............................................................................................................................... 84 Okumura-Hata and Cost-Hata Propagation Models......................................................................... 85 Hata Path Loss Formula ............................................................................................................. 85 Corrections to the Hata Path Loss Formula................................................................................ 85 Calculations in Atoll .................................................................................................................... 85 ITU 529-3 Propagation Model .......................................................................................................... 86 ITU 529-3 Path Loss Formula..................................................................................................... 86 Corrections to the ITU 529-3 Path Loss Formula ....................................................................... 86 Environment Correction ........................................................................................................ 86 Area Size Correction ............................................................................................................. 86 Distance Correction .............................................................................................................. 87 Calculations in Atoll .................................................................................................................... 87 Standard Propagation Model (SPM) ................................................................................................ 87 SPM Path Loss Formula............................................................................................................. 87 Calculations in Atoll .................................................................................................................... 88 Visibility and Distance Between Transmitter and Receiver................................................... 88 Effective Transmitter Antenna Height ................................................................................... 88 Effective Receiver Antenna Height ....................................................................................... 91 Correction for Hilly Regions in Case of LOS ......................................................................... 91 Diffraction .............................................................................................................................. 92 Losses due to Clutter ............................................................................................................ 92 AT283_TRG_E2

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4.5.3.2.7 4.5.3.3 4.5.3.3.1 4.5.3.3.2 4.5.3.4 4.5.4 4.5.4.1 4.5.4.2 4.5.4.2.1 4.5.4.2.2 4.5.5 4.5.5.1 4.5.5.2 4.5.5.2.1 4.5.5.2.2 4.5.6 4.5.6.1 4.5.6.2 4.5.6.2.1 4.5.6.2.2 4.5.7 4.5.7.1 4.5.7.2 4.5.7.3 4.5.8 4.5.8.1 4.5.8.1.1 4.5.8.1.2 4.5.8.1.3 4.5.8.1.4 4.5.8.1.5 4.5.8.1.6 4.5.9 4.5.10 4.5.10.1 4.5.10.2 4.5.10.2.1 4.5.10.2.2 4.5.10.2.3 4.5.10.2.4 4.5.10.2.5 4.6 4.6.1 4.6.2 4.7 4.7.1 4.7.2 4.7.3 4.7.4 4.7.4.1 4.8 4.8.1 4.8.1.1 4.8.1.2 4.8.2 4.8.2.1 4.8.2.1.1 4.8.2.1.2 4.8.2.2 4.8.2.2.1 4.8.2.2.2 4.9 4.9.1 4.9.1.1 4.9.1.2 4.9.2

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Recommendations.................................................................................................................93 Automatic SPM Calibration .........................................................................................................93 General Algorithm..................................................................................................................94 Sample Values for SPM Path Loss Formula Parameters......................................................94 Unmasked Path Loss Calculation ...............................................................................................95 WLL Propagation Model....................................................................................................................96 WLL Path Loss Formula..............................................................................................................96 Calculations in Atoll .....................................................................................................................96 Free Space Loss....................................................................................................................96 Diffraction...............................................................................................................................96 ITU-R P.526-5 Propagation Model....................................................................................................96 ITU 526-5 Path Loss Formula .....................................................................................................96 Calculations in Atoll .....................................................................................................................97 Free Space Loss....................................................................................................................97 Diffraction...............................................................................................................................97 ITU-R P.370-7 Propagation Model....................................................................................................97 ITU 370-7 Path Loss Formula .....................................................................................................97 Calculations in Atoll .....................................................................................................................97 Free Space Loss....................................................................................................................97 Corrected Standard Loss.......................................................................................................97 Erceg-Greenstein (SUI) Propagation Model .....................................................................................98 SUI Terrain Types .......................................................................................................................99 Erceg-Greenstein (SUI) Path Loss Formula................................................................................99 Calculations in Atoll ...................................................................................................................100 ITU-R P.1546-2 Propagation Model................................................................................................100 Calculations in Atoll ...................................................................................................................101 Step 1: Determination of Graphs to be Used.......................................................................101 Step 2: Calculation of Maximum Field Strength...................................................................101 Step 3: Determination of Transmitter Antenna Height .........................................................101 Step 4: Interpolation/Extrapolation of Field Strength ...........................................................101 Step 5: Calculation of Correction Factors ............................................................................103 Step 6: Calculation of Path Loss..........................................................................................104 Sakagami Extended Propagation Model.........................................................................................104 Appendices .....................................................................................................................................106 Free Space Loss .......................................................................................................................106 Diffraction Loss..........................................................................................................................106 Knife-Edge Diffraction..........................................................................................................106 3 Knife-Edge Deygout Method.............................................................................................107 Epstein-Peterson Method ....................................................................................................108 Deygout Method with Correction .........................................................................................108 Millington Method.................................................................................................................109 Path Loss Tuning..................................................................................................................................109 Transmitter Path Loss Tuning .........................................................................................................109 Repeater Path Loss Tuning ............................................................................................................110 Antenna Attenuation Calculation ..........................................................................................................111 Calculation of Azimuth and Tilt Angles............................................................................................111 Antenna Pattern 3-D Interpolation...................................................................................................112 Additional Electrical Downtilt Modelling...........................................................................................113 Antenna Pattern Smoothing ............................................................................................................113 Smoothing Algorithm .................................................................................................................115 Shadowing Model .................................................................................................................................115 Shadowing Margin Calculation........................................................................................................119 Shadowing Margin Calculation in Predictions ...........................................................................120 Shadowing Margin Calculation in Monte-Carlo Simulations......................................................121 Macro-Diversity Gains Calculation ..................................................................................................122 Uplink Macro-Diversity Gain Evaluation ....................................................................................122 Shadowing Error PDF (n Signals)........................................................................................122 Uplink Macro-Diversity Gain ................................................................................................124 Downlink Macro-Diversity Gain Evaluation ...............................................................................124 Shadowing Error PDF (n Signals)........................................................................................124 Downlink Macro-Diversity Gain............................................................................................127 Appendices ...........................................................................................................................................127 Transmitter Radio Equipment .........................................................................................................127 UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE Documents ..............................................128 GSM Documents .......................................................................................................................129 Secondary Antennas.......................................................................................................................129

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Table of Contents

5 5.1 5.1.1 5.1.1.1 5.1.1.2 5.1.2 5.1.2.1 5.1.2.1.1 5.1.2.1.2 5.1.2.1.3 5.1.2.1.4 5.1.2.1.5 5.1.2.1.6 5.1.2.1.7 5.1.2.1.8 5.1.2.2 5.1.2.2.1 5.1.2.2.2 5.2 5.2.1 5.2.2 5.2.3 5.2.3.1 5.2.3.2 5.2.3.2.1 5.2.3.2.2 5.2.3.3 5.2.3.3.1 5.2.3.3.2 5.3 5.3.1 5.3.1.1 5.3.1.2 5.3.1.3 5.3.2 5.3.2.1 5.3.2.2 5.3.2.3 5.3.3 5.3.4 5.3.5 5.3.5.1 5.3.5.1.1 5.3.5.1.2 5.3.5.1.3 5.3.5.1.4 5.3.5.1.5 5.3.5.1.6 5.3.5.1.7 5.3.5.1.8 5.3.5.2 5.3.5.2.1 5.3.5.2.2 5.4 5.4.1 5.4.2 5.4.2.1 5.4.2.2 5.4.3 5.4.3.1 5.4.3.2 5.4.4 5.4.4.1 5.4.4.1.1 5.4.4.1.2 5.4.4.1.3 5.4.4.1.4

© Forsk 2010

GSM GPRS EDGE Networks ....................................................... 133 Signal Level Calculations ..................................................................................................................... 133 Point Analysis ................................................................................................................................. 133 Profile Tab ................................................................................................................................ 133 Reception Tab .......................................................................................................................... 133 Signal Level-based Coverage Predictions ..................................................................................... 134 Service Area Determination...................................................................................................... 134 All Servers........................................................................................................................... 134 Best Signal Level and a Margin .......................................................................................... 134 Second Best Signal Level and a Margin ............................................................................. 134 Best Signal Level per HCS Layer and a Margin.................................................................. 135 Second Best Signal Level per HCS Layer and a Margin .................................................... 135 HCS Servers and a Margin ................................................................................................. 135 Highest Priority HCS Server and a Margin.......................................................................... 136 Best Idle Mode Reselection Criterion (C2).......................................................................... 136 Coverage Display ..................................................................................................................... 137 Coverage Resolution .......................................................................................................... 137 Display Types ..................................................................................................................... 137 Interference-based Calculations .......................................................................................................... 138 Carrier-to-Interference Ratio Calculation........................................................................................ 138 Point Analysis ................................................................................................................................. 141 Interference-based Coverage Predictions...................................................................................... 141 Service Area Determination...................................................................................................... 141 Coverage Area Determination .................................................................................................. 141 Interference Condition Satisfied by At Least One TRX ....................................................... 141 Interference Condition Satisfied by The Worst TRX ........................................................... 142 Coverage Display ..................................................................................................................... 142 Coverage Resolution .......................................................................................................... 142 Display Types ..................................................................................................................... 142 GPRS/EDGE Calculations ................................................................................................................... 142 Coding Scheme Selection and Throughput Calculation Without Ideal Link Adaptation ................. 143 Calculations Based on C .......................................................................................................... 143 Calculations Based on C/I ........................................................................................................ 143 Calculations Based on C/(I+N) ................................................................................................. 144 Coding Scheme Selection and Throughput Calculation With Ideal Link Adaptation ...................... 144 Calculations Based on C .......................................................................................................... 144 Calculations Based on C/I ........................................................................................................ 145 Calculations Based on C/(I+N) ................................................................................................. 145 Application Throughput Calculation................................................................................................ 145 BLER Calculation ........................................................................................................................... 146 GPRS/EDGE Coverage Predictions............................................................................................... 146 Service Area Determination...................................................................................................... 146 All Servers........................................................................................................................... 146 Best Signal Level and a Margin .......................................................................................... 146 Second Best Signal Level and a Margin ............................................................................. 146 Best Signal Level per HCS Layer and a Margin.................................................................. 147 Second Best Signal Level per HCS Layer and a Margin .................................................... 147 HCS Servers and a Margin ................................................................................................. 147 Highest Priority HCS Server and a Margin.......................................................................... 147 Best Idle Mode Reselection Criterion (C2).......................................................................... 148 Coverage Display ..................................................................................................................... 148 Coverage Resolution .......................................................................................................... 148 Display Types ..................................................................................................................... 148 Codec Mode Selection and CQI Calculations ...................................................................................... 150 Circuit Quality Indicator Calculations.............................................................................................. 152 CQI Calculation Without Ideal Link Adaptation .............................................................................. 152 Calculations Based on C/N....................................................................................................... 152 Calculations Based on C/(I+N) ................................................................................................. 152 CQI Calculation With Ideal Link Adaptation ................................................................................... 153 Calculations Based on C/N....................................................................................................... 153 Calculations Based on C/(I+N) ................................................................................................. 153 Circuit Quality Indicators Coverage Predictions ............................................................................. 154 Service Area Determination...................................................................................................... 154 All Servers........................................................................................................................... 154 Best Signal Level and a Margin .......................................................................................... 154 Second Best Signal Level and a Margin ............................................................................. 154 Best Signal Level per HCS Layer and a Margin.................................................................. 154

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5.4.4.1.5 5.4.4.1.6 5.4.4.1.7 5.4.4.2 5.4.4.2.1 5.4.4.2.2 5.5 5.5.1 5.5.1.1 5.5.1.1.1 5.5.1.1.2 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 5.5.2.1.1 5.5.2.1.2 5.5.2.1.3 5.5.2.2 5.5.2.2.1 5.5.2.2.2 5.5.2.2.3 5.6 5.6.1 5.6.1.1 5.6.1.2 5.6.1.2.1 5.6.1.2.2 5.6.1.2.3 5.6.2 5.6.2.1 5.6.2.1.1 5.6.2.1.2 5.6.2.2 5.6.2.2.1 5.6.2.2.2 5.6.2.2.3 5.6.2.2.4 5.6.2.2.5 5.6.2.2.6 5.7 5.7.1 5.7.1.1 5.7.1.2 5.7.1.3 5.7.2 5.7.2.1 5.7.2.1.1 5.7.2.1.2 5.7.2.1.3 5.7.2.1.4 5.7.2.1.5 5.7.2.1.6 5.7.2.2 5.7.2.2.1 5.7.2.2.2 5.7.2.2.3 5.7.2.2.4 5.7.2.2.5 5.7.2.2.6 5.8 5.8.1 5.8.2

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Second Best Signal Level per HCS Layer and a Margin .....................................................155 HCS Servers and a Margin..................................................................................................155 Highest Priority HCS Server and a Margin ..........................................................................155 Coverage Display ......................................................................................................................156 Coverage Resolution ...........................................................................................................156 Display Types ......................................................................................................................156 Traffic Analysis .....................................................................................................................................156 Traffic Distribution ...........................................................................................................................156 Normal Cells (Nonconcentric, No HCS Layer) ..........................................................................156 Circuit Switched Services ....................................................................................................156 Packet Switched Services ...................................................................................................157 Concentric Cells ........................................................................................................................157 Circuit Switched Services ....................................................................................................157 Packet Switched Services ...................................................................................................157 HCS Layers ...............................................................................................................................157 Circuit Switched Services ....................................................................................................157 Packet Switched Services ...................................................................................................157 Calculation of the Traffic Demand per Subcell................................................................................157 User Profile Traffic Maps ...........................................................................................................157 Normal Cells (Nonconcentric, No HCS Layer).....................................................................157 Concentric Cells...................................................................................................................158 HCS Layers .........................................................................................................................159 Sector Traffic Maps ...................................................................................................................162 Normal Cells (Nonconcentric, No HCS Layer).....................................................................162 Concentric Cells...................................................................................................................163 HCS Layers .........................................................................................................................163 Network Dimensioning..........................................................................................................................167 Dimensioning Models and Quality Graphs......................................................................................167 Circuit Switched Traffic..............................................................................................................168 Packet Switched Traffic.............................................................................................................168 Throughput ..........................................................................................................................168 Delay....................................................................................................................................170 Blocking Probability .............................................................................................................170 Network Dimensioning Process ......................................................................................................172 Network Dimensioning Engine ..................................................................................................172 Inputs ...................................................................................................................................172 Outputs ................................................................................................................................172 Network Dimensioning Steps ....................................................................................................172 Step 1: Timeslots Required for CS Traffic ...........................................................................172 Step 2: TRXs Required for CS Traffic and Dedicated PS Timeslots ...................................173 Step 3: Effective CS Blocking, Effective CS Traffic Overflow and Served CS Traffic..........173 Step 4: TRXs to Add for PS Traffic ......................................................................................173 Step 5: Served PS Traffic ....................................................................................................175 Step 6: Total Traffic Load ....................................................................................................176 Key Performance Indicators Calculation...............................................................................................176 Circuit Switched Traffic ...................................................................................................................176 Erlang B.....................................................................................................................................176 Erlang C ....................................................................................................................................176 Served Circuit Switched Traffic .................................................................................................177 Packet Switched Traffic...................................................................................................................177 Case 1: Total Traffic Demand > Dedicated + Shared Timeslots ...............................................177 Traffic Load..........................................................................................................................177 Packet Switched Traffic Overflow ........................................................................................177 Throughput Reduction Factor ..............................................................................................177 Delay....................................................................................................................................177 Blocking Probability .............................................................................................................177 Served Packet Switched Traffic...........................................................................................177 Case 2: Total Traffic Demand < Dedicated + Shared Timeslots ...............................................178 Traffic Load..........................................................................................................................178 Packet Switched Traffic Overflow ........................................................................................178 Throughput Reduction Factor ..............................................................................................178 Delay....................................................................................................................................178 Blocking Probability .............................................................................................................178 Served Packet Switched Traffic...........................................................................................178 Neighbour Allocation.............................................................................................................................178 Global Allocation for All Transmitters ..............................................................................................179 Allocation for a Group of Transmitters or One Transmitter .............................................................182

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Table of Contents

5.9 5.9.1 5.9.1.1 5.9.1.2 5.9.1.2.1 5.9.1.2.2 5.9.1.2.3 5.9.2 5.9.2.1 5.9.2.2 5.9.2.3 5.9.3 5.9.3.1 5.9.3.2 5.9.3.3 5.9.3.4 5.9.3.4.1 5.9.3.4.2 5.9.3.4.3 5.9.3.5

6 6.1 6.1.1 6.1.2 6.1.2.1 6.1.2.2 6.1.3 6.1.3.1 6.1.3.1.1 6.1.3.1.2 6.1.3.1.3 6.1.3.2 6.1.3.2.1 6.1.3.2.2 6.2 6.2.1 6.2.2 6.2.3 6.2.4 6.3 6.4 6.4.1 6.4.1.1 6.4.1.1.1 6.4.1.1.2 6.4.1.2 6.4.1.2.1 6.4.1.2.2 6.4.1.2.3 6.4.2 6.4.2.1 6.4.2.2 6.4.2.3 6.4.2.3.1 6.4.2.3.2 6.4.2.3.3 6.4.2.3.4 6.4.2.3.5 6.4.2.3.6 6.4.2.3.7 6.4.2.4 6.4.2.4.1 6.4.2.4.2 6.4.2.4.3 6.4.2.4.4 6.4.2.5

© Forsk 2010

AFP Appendices .................................................................................................................................. 182 The AFP Cost Function .................................................................................................................. 182 Cost Function............................................................................................................................ 183 Cost Components ..................................................................................................................... 184 Separation Violation Cost Component ................................................................................ 184 Interference Cost Component ............................................................................................. 185 I_DIV, F_DIV and Other Advanced Cost Parameters ......................................................... 187 The AFP Blocked Traffic Cost ........................................................................................................ 187 Calculation of New Traffic Loads Including Blocked Traffic Loads ........................................... 188 Recalculation of CS and PS From Traffic Loads ...................................................................... 189 Testing the Blocked Cost Using Traffic Analysis ...................................................................... 190 Interferences .................................................................................................................................. 190 Using Interferences................................................................................................................... 190 Cumulative Density Function of C/I Levels ............................................................................... 190 Precise Definition...................................................................................................................... 191 Precise Interference Distribution Strategy ................................................................................ 191 Direct Availability of Precise Interference Distribution to the AFP....................................... 191 Efficient Calculation and Storage of Interference Distribution............................................. 191 Robustness of the IM .......................................................................................................... 191 Traffic Load and Interference Information Discrimination ......................................................... 191

UMTS HSPA Networks ................................................................. 195 General Prediction Studies .................................................................................................................. 195 Calculation Criteria ......................................................................................................................... 195 Point Analysis ................................................................................................................................. 195 Profile Tab ................................................................................................................................ 195 Reception Tab .......................................................................................................................... 195 Coverage Studies ........................................................................................................................... 196 Service Area Determination...................................................................................................... 196 All Servers........................................................................................................................... 196 Best Signal Level and a Margin .......................................................................................... 196 Second Best Signal Level and a Margin ............................................................................. 196 Coverage Display ..................................................................................................................... 197 Plot Resolution .................................................................................................................... 197 Display Types ..................................................................................................................... 197 Definitions and Formulas ..................................................................................................................... 198 Inputs.............................................................................................................................................. 198 Ec/I0 Calculation ............................................................................................................................ 204 DL Eb/Nt Calculation ...................................................................................................................... 204 UL Eb/Nt Calculation ...................................................................................................................... 205 Active Set Management ....................................................................................................................... 206 Simulations........................................................................................................................................... 206 Generating a Realistic User Distribution ........................................................................................ 207 Simulations Based on User Profile Traffic Maps ...................................................................... 207 Circuit Switched Service (i) ................................................................................................. 207 Packet Switched Service (j) ................................................................................................ 208 Simulations Based on Sector Traffic Maps............................................................................... 210 Throughputs in Uplink and Downlink................................................................................... 211 Total Number of Users (All Activity Statuses) ..................................................................... 211 Number of Users per Activity Status ................................................................................... 212 Power Control Simulation............................................................................................................... 212 Algorithm Initialization............................................................................................................... 213 R99 Part of the Algorithm ......................................................................................................... 214 HSDPA Part of the Algorithm.................................................................................................... 218 HSDPA Power Allocation .................................................................................................... 218 Number of HS-SCCH Channels and Maximum Number of HSDPA Bearer Users............. 219 HSDPA Bearer Allocation Process ..................................................................................... 219 Fast Link Adaptation Modelling ........................................................................................... 221 MIMO Modelling .................................................................................................................. 231 Scheduling Algorithms ........................................................................................................ 231 Dual-Cell HSDPA ................................................................................................................ 233 HSUPA Part of the Algorithm.................................................................................................... 236 Admission Control ............................................................................................................... 237 HSUPA Bearer Allocation Process ..................................................................................... 239 Noise Rise Scheduling ........................................................................................................ 240 Radio Resource Control...................................................................................................... 244 Convergence Criteria................................................................................................................ 244

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Technical Reference Guide

6.4.3 6.4.3.1 6.4.3.2 6.4.3.2.1 6.4.3.2.2 6.4.3.2.3 6.4.3.2.4 6.4.4 6.4.4.1 6.4.4.2 6.4.4.2.1 6.4.4.2.2 6.4.4.2.3 6.4.4.3 6.4.4.3.1 6.4.4.3.2 6.4.4.4 6.4.4.5 6.4.4.6 6.5 6.5.1 6.5.1.1 6.5.1.1.1 6.5.1.1.2 6.5.1.1.3 6.5.2 6.5.2.1 6.5.2.1.1 6.5.2.1.2 6.5.2.2 6.5.2.2.1 6.5.2.2.2 6.5.2.3 6.5.2.3.1 6.5.2.3.2 6.5.2.4 6.5.2.4.1 6.5.2.4.2 6.5.2.4.3 6.5.2.5 6.5.2.5.1 6.5.2.5.2 6.5.2.6 6.5.2.6.1 6.5.2.6.2 6.5.2.6.3 6.6 6.6.1 6.6.2 6.6.3 6.6.3.1 6.6.3.2 6.7 6.7.1 6.7.1.1 6.7.1.2 6.7.1.2.1 6.7.1.2.2 6.7.1.3 6.7.1.3.1 6.7.1.3.2 6.7.1.3.3 6.7.2 6.7.2.1 6.7.2.1.1 6.7.2.1.2 6.7.2.1.3 6.7.2.1.4

12

Results ............................................................................................................................................244 R99 Related Results .................................................................................................................244 HSPA Related Results ..............................................................................................................246 Statistics Tab .......................................................................................................................246 Mobiles Tab .........................................................................................................................247 Cells Tab..............................................................................................................................250 Sites Tab..............................................................................................................................252 Appendices .....................................................................................................................................252 Admission Control in the R99 Part ............................................................................................252 Resources Management ...........................................................................................................252 OVSF Codes Management..................................................................................................252 Channel Elements Management .........................................................................................254 Iub Backhaul Throughput.....................................................................................................254 Downlink Load Factor Calculation .............................................................................................255 Downlink Load Factor per Cell.............................................................................................255 Downlink Load Factor per Mobile ........................................................................................257 Uplink Load Factor Due to One User ........................................................................................257 Inter-carrier Power Sharing Modelling .......................................................................................259 Best Server Determination in Monte Carlo Simulations - Old Method ......................................259 UMTS HSPA Prediction Studies...........................................................................................................261 Point Analysis..................................................................................................................................261 AS Analysis Tab ........................................................................................................................261 Bar Graph and Pilot Sub-Menu............................................................................................261 Downlink Sub-Menu.............................................................................................................264 Uplink Sub-Menu .................................................................................................................268 Coverage Studies............................................................................................................................272 Pilot Reception Analysis ............................................................................................................272 Prediction Study Inputs........................................................................................................273 Study Display Options .........................................................................................................273 Downlink Service Area Analysis ................................................................................................273 Prediction Study Inputs........................................................................................................274 Study Display Options .........................................................................................................274 Uplink Service Area Analysis ....................................................................................................275 Prediction Study Inputs........................................................................................................275 Study Display Options .........................................................................................................276 Downlink Total Noise Analysis ..................................................................................................277 Study Inputs.........................................................................................................................277 Analysis on All Carriers........................................................................................................277 Analysis on a Specific Carrier..............................................................................................278 HSDPA Prediction Study ...........................................................................................................278 Prediction Study Inputs........................................................................................................278 Study Display Options .........................................................................................................278 HSUPA Prediction Study ...........................................................................................................282 Prediction Study Inputs........................................................................................................282 Calculation Options..............................................................................................................283 Display Options....................................................................................................................283 Automatic Neighbour Allocation............................................................................................................285 Neighbour Allocation for All Transmitters........................................................................................285 Neighbour Allocation for a Group of Transmitters or One Transmitter............................................289 Importance Calculation ...................................................................................................................289 Importance of Intra-carrier Neighbours .....................................................................................289 Importance of Inter-carrier Neighbours .....................................................................................290 Primary Scrambling Code Allocation ....................................................................................................291 Automatic Allocation Description.....................................................................................................291 Options and Constraints ............................................................................................................291 Allocation Process.....................................................................................................................292 Single Carrier Network.........................................................................................................293 Multi-Carrier Network...........................................................................................................293 Priority Determination................................................................................................................294 Cell Priority ..........................................................................................................................294 Transmitter Priority ..............................................................................................................296 Site Priority ..........................................................................................................................296 Allocation Examples........................................................................................................................296 Allocation Strategies and Use a Maximum of Codes ................................................................296 Strategy: Clustered ..............................................................................................................297 Strategy: Distributed ............................................................................................................298 Strategy: ‘One Cluster per Site ............................................................................................298 Strategy: ‘Distributed per Site ..............................................................................................299 AT283_TRG_E2

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6.7.2.2 6.8 6.8.1 6.8.2 6.8.2.1 6.8.2.2 6.8.2.3 6.8.2.3.1 6.8.2.3.2

7 7.1 7.1.1 7.1.2 7.1.2.1 7.1.2.2 7.1.3 7.1.3.1 7.1.3.1.1 7.1.3.1.2 7.1.3.1.3 7.1.3.2 7.1.3.2.1 7.1.3.2.2 7.2 7.2.1 7.2.1.1 7.2.1.2 7.2.1.3 7.2.1.4 7.2.1.5 7.2.2 7.2.2.1 7.2.2.2 7.2.2.3 7.2.2.4 7.3 7.4 7.4.1 7.4.1.1 7.4.1.1.1 7.4.1.1.2 7.4.1.2 7.4.1.3 7.4.2 7.4.2.1 7.4.2.1.1 7.4.2.1.2 7.4.2.1.3 7.4.2.2 7.4.2.2.1 7.4.2.2.2 7.4.2.2.3 7.4.3 7.4.3.1 7.4.3.2 7.4.3.2.1 7.4.3.2.2 7.4.3.3 7.4.3.3.1 7.4.3.3.2 7.4.3.4 7.5 7.5.1 7.5.1.1 7.5.1.2 7.5.1.2.1 7.5.1.2.2 © Forsk 2010

Allocate Carriers Identically ...................................................................................................... 299 Automatic GSM-UMTS Neighbour Allocation ...................................................................................... 300 Overview ........................................................................................................................................ 300 Automatic Allocation Description.................................................................................................... 300 Algorithm Based on Distance ................................................................................................... 300 Algorithm Based on Coverage Overlapping ............................................................................. 301 Appendices ............................................................................................................................... 303 Delete Existing Neighbours Option ..................................................................................... 303 Calculation of Inter-Transmitter Distance............................................................................ 303

CDMA2000 Networks ................................................................... 307 General Prediction Studies .................................................................................................................. 307 Calculation Criteria ......................................................................................................................... 307 Point Analysis ................................................................................................................................. 307 Profile Tab ................................................................................................................................ 307 Reception Tab .......................................................................................................................... 308 Coverage Studies ........................................................................................................................... 308 Service Area Determination...................................................................................................... 308 All Servers........................................................................................................................... 308 Best Signal Level and a Margin .......................................................................................... 308 Second Best Signal Level and a Margin ............................................................................. 308 Coverage Display ..................................................................................................................... 309 Plot Resolution .................................................................................................................... 309 Display Types ..................................................................................................................... 309 Definitions and Formulas ..................................................................................................................... 310 Parameters Used for CDMA2000 1xRTT Modelling ...................................................................... 310 Inputs ........................................................................................................................................ 310 Ec/I0 Calculation....................................................................................................................... 314 DL Eb/Nt Calculation ................................................................................................................ 314 UL Eb/Nt Calculation ................................................................................................................ 315 Simulation Results .................................................................................................................... 317 Parameters Used for CDMA2000 1xEV-DO Modelling .................................................................. 318 Inputs ........................................................................................................................................ 318 Ec/I0 and Ec/Nt Calculations .................................................................................................... 321 UL Eb/Nt Calculation ................................................................................................................ 322 Simulation Results .................................................................................................................... 323 Active Set Management ....................................................................................................................... 324 Simulations........................................................................................................................................... 325 Generating a Realistic User Distribution ........................................................................................ 325 Number of Users, User Activity Status and User Data Rate..................................................... 325 Simulations Based on User Profile Traffic Maps................................................................. 325 Simulations Based on Sector Traffic Maps ......................................................................... 328 Transition Flags for 1xEV-DO Rev.0 User Data Rates............................................................. 333 User Geographical Position ...................................................................................................... 333 Network Regulation Mechanism..................................................................................................... 333 CDMA2000 1xRTT Power Control Simulation Algorithm.......................................................... 333 Algorithm Initialization ......................................................................................................... 334 Presentation of the Algorithm.............................................................................................. 334 Convergence Criterion ........................................................................................................ 340 CDMA2000 1xEV-DO Power/Data Rate Control Simulation Algorithm .................................... 341 Algorithm Initialization ......................................................................................................... 342 Presentation of the Algorithm.............................................................................................. 342 Convergence Criterion ........................................................................................................ 347 Appendices..................................................................................................................................... 348 Admission Control..................................................................................................................... 348 Resources Management........................................................................................................... 348 Walsh Code Management .................................................................................................. 348 Channel Element Management .......................................................................................... 349 Downlink Load Factor Calculation ............................................................................................ 349 Downlink Load Factor per Cell ............................................................................................ 349 Downlink Load Factor per Mobile........................................................................................ 351 Best Server Determination in Monte Carlo Simulations - Old Method...................................... 351 CDMA2000 Prediction Studies............................................................................................................. 353 Point Analysis: The AS Analysis Tab ............................................................................................. 353 Bar Graph and Pilot Sub-Menu................................................................................................. 353 Downlink Sub-Menu.................................................................................................................. 355 CDMA2000 1xRTT.............................................................................................................. 355 CDMA2000 1xEV-DO ......................................................................................................... 359 AT283_TRG_E2

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Technical Reference Guide

7.5.1.3 7.5.1.3.1 7.5.1.3.2 7.5.2 7.5.2.1 7.5.2.2 7.5.2.2.1 7.5.2.2.2 7.5.2.3 7.5.2.3.1 7.5.2.3.2 7.5.2.4 7.5.2.4.1 7.5.2.4.2 7.6 7.6.1 7.6.2 7.6.3 7.6.3.1 7.6.3.2 7.7 7.7.1 7.7.1.1 7.7.1.2 7.7.1.2.1 7.7.1.2.2 7.7.1.2.3 7.7.1.3 7.7.1.3.1 7.7.1.3.2 7.7.1.3.3 7.7.2 7.7.2.1 7.7.2.2 7.7.2.3 7.8 7.8.1 7.8.2 7.8.2.1 7.8.2.2 7.8.2.3

8 8.1 8.1.1 8.1.2 8.1.3 8.1.4 8.1.5 8.1.6 8.1.7 8.1.8 8.1.8.1 8.1.8.2 8.1.8.3 8.2 8.2.1 8.2.1.1 8.2.1.2 8.2.2 8.2.2.1 8.2.2.2 8.2.2.2.1 8.2.2.2.2 8.2.2.3 8.2.2.4 8.2.2.5 8.2.2.5.1

14

Uplink Sub-Menu.......................................................................................................................360 CDMA2000 1xRTT ..............................................................................................................360 CDMA2000 1xEV-DO ..........................................................................................................364 Coverage Studies............................................................................................................................367 Pilot Reception Analysis ............................................................................................................367 Downlink Service Area Analysis ................................................................................................368 CDMA2000 1xRTT ..............................................................................................................368 CDMA2000 1xEV-DO ..........................................................................................................370 Uplink Service Area Analysis ....................................................................................................371 CDMA2000 1xRTT ..............................................................................................................371 CDMA2000 1xEV-DO ..........................................................................................................372 Downlink Total Noise Analysis ..................................................................................................375 Analysis on all Carriers ........................................................................................................375 Analysis on a Specific Carrier..............................................................................................376 Automatic Neighbour Allocation............................................................................................................376 Neighbour Allocation for all Transmitters ........................................................................................376 Neighbour Allocation for a Group of Transmitters or One Transmitter............................................379 Importance Calculation ...................................................................................................................379 Importance of Intra-carrier Neighbours .....................................................................................379 Importance of Inter-carrier Neighbours .....................................................................................380 PN Offset Allocation..............................................................................................................................381 Automatic Allocation Description.....................................................................................................381 Options and Constraints ............................................................................................................381 Allocation Process.....................................................................................................................382 Single Carrier Network.........................................................................................................382 Multi-Carrier Network...........................................................................................................383 Difference between Adjacent and Distributed PN-Clusters .................................................383 Priority Determination................................................................................................................384 Cell Priority ..........................................................................................................................384 Transmitter Priority ..............................................................................................................386 Site Priority ..........................................................................................................................386 Allocation Examples........................................................................................................................386 Strategy: PN Offset per Cell ......................................................................................................387 Strategy: Adjacent PN-Clusters Per Site...................................................................................387 Strategy: ‘Distributed PN-Clusters Per Site ...............................................................................388 Automatic GSM-CDMA Neighbour Allocation.......................................................................................388 Overview .........................................................................................................................................388 Automatic Allocation Description.....................................................................................................388 Algorithm Based on Distance ....................................................................................................389 Algorithm Based on Coverage Overlapping ..............................................................................389 Delete Existing Neighbours Option ...........................................................................................391

TD-SCDMA Networks....................................................................395 Definitions and Formulas ......................................................................................................................395 Inputs ..............................................................................................................................................395 P-CCPCH Eb/Nt and C/I Calculation ..............................................................................................399 DwPCH C/I Calculation ...................................................................................................................400 DL TCH Eb/Nt and C/I Calculation..................................................................................................400 UL TCH Eb/Nt and C/I Calculation..................................................................................................400 Interference Calculation ..................................................................................................................401 HSDPA Dynamic Power Calculations .............................................................................................401 Smart Antenna Models....................................................................................................................401 Downlink Beamforming .............................................................................................................401 Uplink Beamforming ..................................................................................................................402 Uplink Beamforming and Interference Cancellation (MMSE) ....................................................402 Signal Level Based Calculations ..........................................................................................................403 Point Analysis..................................................................................................................................403 Profile Tab .................................................................................................................................403 Reception Tab ...........................................................................................................................403 RSCP Based Coverage Predictions................................................................................................404 Calculation Criteria ....................................................................................................................404 P-CCPCH RSCP Coverage Prediction .....................................................................................404 Coverage Condition .............................................................................................................404 Coverage Display ................................................................................................................405 Best Server P-CCPCH Coverage Prediction.............................................................................405 P-CCPCH Pollution Coverage Prediction..................................................................................405 DwPCH RSCP Coverage Prediction .........................................................................................406 Coverage Condition .............................................................................................................406 AT283_TRG_E2

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Table of Contents

8.2.2.5.2 8.2.2.6 8.2.2.6.1 8.2.2.6.2 8.2.2.7 8.2.2.7.1 8.2.2.7.2 8.2.2.8 8.3 8.3.1 8.3.1.1 8.3.1.1.1 8.3.1.1.2 8.3.1.2 8.3.1.2.1 8.3.1.2.2 8.3.1.2.3 8.3.2 8.3.2.1 8.3.2.2 8.3.2.2.1 8.3.2.2.2 8.3.2.2.3 8.3.2.2.4 8.3.2.2.5 8.3.2.2.6 8.3.2.2.7 8.3.2.3 8.3.2.3.1 8.3.2.3.2 8.3.2.3.3 8.3.2.3.4 8.3.2.3.5 8.3.2.4 8.4 8.4.1 8.4.2 8.4.3 8.4.4 8.4.5 8.4.6 8.4.7 8.4.8 8.4.9 8.4.10 8.4.11 8.5 8.5.1 8.5.1.1 8.5.1.2 8.5.1.3 8.5.1.4 8.5.1.4.1 8.5.1.4.2 8.5.1.4.3 8.5.1.5 8.5.2 8.5.3 8.5.4 8.5.4.1 8.5.4.1.1 8.5.4.1.2 8.5.4.2 8.5.4.2.1 8.5.4.2.2 8.5.4.2.3 8.6 8.6.1 © Forsk 2010

Coverage Display................................................................................................................ 406 UpPCH RSCP Coverage Prediction ......................................................................................... 406 Coverage Condition ............................................................................................................ 406 Coverage Display................................................................................................................ 406 Baton Handover Coverage Prediction ...................................................................................... 407 Coverage Condition ............................................................................................................ 407 Coverage Display................................................................................................................ 407 Scrambling Code Interference Analysis.................................................................................... 407 Monte Carlo Simulations ...................................................................................................................... 408 Generating a Realistic User Distribution ........................................................................................ 408 Simulations Based on User Profile Traffic Maps ...................................................................... 408 Circuit Switched Service (i) ................................................................................................. 409 Packet Switched Service (j) ................................................................................................ 409 Simulations Based on Sector Traffic Maps............................................................................... 412 Throughputs in Uplink and Downlink................................................................................... 412 Total Number of Users (All Activity Statuses) ..................................................................... 412 Number of Users per Activity Status ................................................................................... 413 Power Control Simulation............................................................................................................... 413 Algorithm Initialisation............................................................................................................... 414 R99 Part of the Algorithm ......................................................................................................... 414 Determination of Mi’s Best Server (SBS(Mi))...................................................................... 414 Dynamic Channel Allocation ............................................................................................... 415 Uplink Power Control .......................................................................................................... 416 Downlink Power Control...................................................................................................... 418 Uplink Signals Update......................................................................................................... 420 Downlink Signals Update .................................................................................................... 420 Control of Radio Resource Limits (Downlink Traffic Power and Uplink Load) .................... 420 HSDPA Part of the Algorithm.................................................................................................... 421 HSDPA Power Allocation .................................................................................................... 421 Connection Status and Number of HSDPA Users .............................................................. 423 HSDPA Admission Control.................................................................................................. 423 HSDPA Dynamic Channel Allocation.................................................................................. 424 Ressource Unit Saturation .................................................................................................. 424 Convergence Criteria................................................................................................................ 424 TD-SCDMA Prediction Studies ............................................................................................................ 425 P-CCPCH Reception Analysis (Eb/Nt) or (C/I) ............................................................................... 425 DwPCH Reception Analysis (C/I) ................................................................................................... 426 Downlink TCH RSCP Coverage ..................................................................................................... 428 Uplink TCH RSCP Coverage ......................................................................................................... 428 Downlink Total Noise...................................................................................................................... 429 Downlink Service Area (Eb/Nt) or (C/I)........................................................................................... 430 Uplink Service Area (Eb/Nt) or (C/I) ............................................................................................... 432 Effective Service Area (Eb/Nt) or (C/I) ........................................................................................... 433 Cell to Cell Interference.................................................................................................................. 434 UpPCH Interference ....................................................................................................................... 435 HSDPA Coverage .......................................................................................................................... 435 Smart Antenna Modelling..................................................................................................................... 436 Modelling in Simulations................................................................................................................. 437 Grid of Beams Modelling .......................................................................................................... 437 Adaptive Beam Modelling ......................................................................................................... 438 Statistical Modelling .................................................................................................................. 439 Beamforming Smart Antenna Models....................................................................................... 439 Downlink Beamforming ....................................................................................................... 440 Uplink Beamforming............................................................................................................ 441 Uplink Beamforming and Interference Cancellation (MMSE).............................................. 442 3rd Party Smart Antenna Modelling.......................................................................................... 444 Construction of the Geographic Distributions ................................................................................. 444 Modelling in Coverage Predictions ................................................................................................. 445 HSDPA Coverage Prediction ......................................................................................................... 446 Fast Link Adaptation Modelling................................................................................................. 446 CQI Based on P-CCPCH Quality ........................................................................................ 446 CQI Based on HS-PDSCH Quality...................................................................................... 450 Coverage Prediction Display Options ....................................................................................... 451 Colour per CQI .................................................................................................................... 451 Colour per Peak Throughput............................................................................................... 451 Colour per HS-PDSCH Ec/Nt.............................................................................................. 451 N-Frequency Mode and Carrier Allocation........................................................................................... 452 Automatic Carrier Allocation........................................................................................................... 452 AT283_TRG_E2

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Technical Reference Guide

8.7 8.7.1 8.7.2 8.7.3 8.8 8.8.1 8.8.1.1 8.8.1.2 8.8.1.3 8.8.1.3.1 8.8.1.3.2 8.8.1.4 8.8.1.4.1 8.8.1.4.2 8.8.1.4.3 8.8.2 8.8.2.1 8.8.2.1.1 8.8.2.1.2 8.8.2.1.3 8.8.2.1.4 8.8.2.2 8.9 8.9.1 8.9.1.1 8.9.1.2 8.9.1.3 8.9.1.3.1 8.9.1.3.2

9 9.1 9.1.1 9.1.2 9.1.3 9.1.3.1 9.1.3.2 9.1.3.3 9.1.3.4 9.1.3.5 9.1.4 9.1.4.1 9.1.4.2 9.1.4.3 9.1.4.4 9.1.4.5 9.1.4.6 9.1.4.7 9.1.4.8 9.1.4.9 9.1.4.10 9.1.5 9.1.5.1 9.1.5.2 9.1.6 9.1.6.1 9.1.7 9.1.7.1 9.1.7.2 9.1.7.3 9.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.4.1 9.2.4.1.1 9.2.4.1.2

16

Neighbour Allocation.............................................................................................................................452 Neighbour Allocation for All Transmitters........................................................................................453 Neighbour Allocation for a Group of Transmitters or One Transmitter............................................456 Importance Calculation ...................................................................................................................456 Scrambling Code Allocation..................................................................................................................457 Automatic Allocation Description.....................................................................................................457 Allocation Constraints and Options ...........................................................................................457 Allocation Strategies..................................................................................................................458 Allocation Process.....................................................................................................................458 Single Carrier Network.........................................................................................................459 Multi-Carrier Network...........................................................................................................460 Priority Determination................................................................................................................460 Cell Priority ..........................................................................................................................460 Transmitter Priority ..............................................................................................................462 Site Priority ..........................................................................................................................463 Scrambling Code Allocation Example .............................................................................................463 Single Carrier Network ..............................................................................................................463 Strategy: Clustered ..............................................................................................................464 Strategy: Distributed per Cell...............................................................................................464 Strategy: One SYNC_DL Code per Site ..............................................................................465 Strategy: Distributed per Site...............................................................................................465 Multi Carrier Network.................................................................................................................465 Automatic GSM/TD-SCDMA Neighbour Allocation ..............................................................................466 Automatic Allocation Description.....................................................................................................466 Algorithm Based on Distance ....................................................................................................467 Algorithm Based on Coverage Overlapping ..............................................................................467 Appendices................................................................................................................................469 Delete Existing Neighbours Option......................................................................................469 Calculation of Inter-Transmitter Distance ............................................................................469

WiMAX BWA Networks..................................................................473 Definitions and Formulas ......................................................................................................................473 Input ................................................................................................................................................473 Co- and Adjacent Channel Overlaps Calculation............................................................................477 Preamble Signal Quality Calculations .............................................................................................477 Preamble Signal Level Calculation............................................................................................477 Preamble Noise Calculation ......................................................................................................478 Preamble Interference Calculation ............................................................................................478 Preamble C/N Calculation .........................................................................................................478 Preamble C/(I+N) Calculation....................................................................................................478 Traffic and Pilot Signal Quality Calculations ...................................................................................478 Traffic and Pilot Signal Level Calculation (DL) ..........................................................................478 Traffic and Pilot Noise Calculation (DL) ....................................................................................479 Traffic and Pilot Interference Calculation (DL) ..........................................................................479 Traffic and Pilot C/N Calculation (DL) .......................................................................................480 Traffic and Pilot C/(I+N) Calculation (DL) ..................................................................................481 Traffic Signal Level Calculation (UL) .........................................................................................481 Traffic Noise Calculation (UL) ...................................................................................................481 Traffic Interference Calculation (UL) .........................................................................................482 Traffic C/N Calculation (UL) ......................................................................................................482 Traffic C/(I+N) Calculation (UL) .................................................................................................482 Throughput Calculation ...................................................................................................................482 Calculation of Total Cell Resources ..........................................................................................482 Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation...........484 Scheduling and Radio Resource Management...............................................................................485 User Throughput Calculation.....................................................................................................486 Smart Antenna Models....................................................................................................................487 Downlink Beamforming .............................................................................................................487 Uplink Beamforming ..................................................................................................................487 Uplink Beamforming and Interference Cancellation (MMSE) ....................................................488 Calculation Processes ..........................................................................................................................488 Point Analysis: Profile Tab ..............................................................................................................488 Point Analysis: Reception Tab ........................................................................................................488 Point Analysis: Interference Tab .....................................................................................................489 Preamble Signal Level Coverage Predictions.................................................................................489 Coverage Area Determination...................................................................................................490 All Servers ...........................................................................................................................490 Best Signal Level and a Margin ...........................................................................................490 AT283_TRG_E2

© Forsk 2010

Table of Contents

9.2.4.1.3 9.2.4.2 9.2.4.2.1 9.2.4.2.2 9.2.5 9.2.5.1 9.2.5.2 9.2.5.3 9.2.5.3.1 9.2.5.3.2 9.2.5.3.3 9.2.6 9.2.7 9.2.7.1 9.2.7.1.1 9.2.7.1.2 9.2.7.2 9.2.8 9.2.8.1 9.2.8.2 9.2.8.3 9.2.8.3.1 9.2.8.3.2 9.2.8.3.3 9.2.8.3.4 9.2.8.3.5 9.2.8.3.6 9.2.8.3.7 9.2.8.3.8 9.2.8.3.9 9.3 9.3.1 9.3.1.1 9.3.1.2 9.3.1.3 9.3.1.4 9.3.1.5 9.3.2 9.3.2.1 9.3.2.2 9.3.2.3 9.3.2.4 9.3.2.5 9.3.3 9.3.4 9.3.5 9.3.6 9.3.6.1 9.3.6.2 9.3.6.3 9.3.6.3.1 9.3.6.3.2 9.3.6.4 9.3.6.5 9.3.6.6 9.3.6.7 9.3.6.8 9.3.6.8.1 9.3.6.8.2 9.3.6.9 9.3.6.10 9.3.7 9.3.7.1 9.3.7.1.1 9.3.7.1.2 9.3.7.1.3 9.3.7.1.4 9.3.7.2 © Forsk 2010

Second Best Signal Level and a Margin ............................................................................. 490 Coverage Display ..................................................................................................................... 490 Coverage Resolution .......................................................................................................... 490 Display Types ..................................................................................................................... 490 Effective Signal Analysis Coverage Predictions ............................................................................. 491 Coverage Area Determination .................................................................................................. 492 Coverage Parameter Calculation.............................................................................................. 492 Coverage Display ..................................................................................................................... 492 Coverage Resolution .......................................................................................................... 492 Effective Signal Analysis (DL) Display Types ..................................................................... 492 Effective Signal Analysis (UL) Display Types ..................................................................... 493 Calculations on Subscriber Lists .................................................................................................... 494 Monte Carlo Simulations ................................................................................................................ 494 Generating a Realistic User Distribution................................................................................... 494 Simulations Based on User Profile Traffic Maps and Subscriber Lists ............................... 495 Simulations Based on Sector Traffic Maps ......................................................................... 496 Simulation Process ................................................................................................................... 498 C/(I+N)-Based Coverage Predictions ............................................................................................. 502 Coverage Area Determination .................................................................................................. 503 Coverage Parameter Calculation.............................................................................................. 503 Coverage Display ..................................................................................................................... 504 Coverage Resolution .......................................................................................................... 504 Coverage by C/(I+N) Level (DL) Display Types.................................................................. 504 Coverage by Best Bearer (DL) Display Types .................................................................... 505 Coverage by Throughput (DL) Display Types..................................................................... 505 Coverage by Quality Indicator (DL) Display Types ............................................................. 506 Coverage by C/(I+N) Level (UL) Display Types.................................................................. 506 Coverage by Best Bearer (UL) Display Types .................................................................... 507 Coverage by Throughput (UL) Display Types..................................................................... 507 Coverage by Quality Indicator (UL) Display Types ............................................................. 508 Calculation Algorithms ......................................................................................................................... 508 Co- and Adjacent Channel Overlaps Calculation ........................................................................... 508 Conversion From Channel Numbers to Start and End Frequencies ........................................ 509 Co-Channel Overlap Calculation .............................................................................................. 510 Adjacent Channel Overlap Calculation ..................................................................................... 510 FDD – TDD Overlap Ratio Calculation ..................................................................................... 511 Total Overlap Ratio Calculation ................................................................................................ 512 Preamble Signal Level and Quality Calculations............................................................................ 512 Preamble Signal Level Calculation ........................................................................................... 512 Preamble Noise Calculation ..................................................................................................... 514 Preamble Interference Calculation ........................................................................................... 515 Preamble C/N Calculation ........................................................................................................ 516 Preamble C/(I+N) Calculation ................................................................................................... 517 Best Server Determination ............................................................................................................. 517 Service Area Calculation ................................................................................................................ 518 Permutation Zone Selection (WiMAX 802.16e).............................................................................. 519 Traffic and Pilot Signal Level and Quality Calculations .................................................................. 520 Traffic and Pilot Signal Level Calculation (DL) ......................................................................... 520 Traffic and Pilot Noise Calculation (DL).................................................................................... 521 Traffic and Pilot Interference Calculation (DL).......................................................................... 522 Traffic and Pilot Interference Signal Levels Calculation (DL).............................................. 523 Effective Traffic and Pilot Interference Calculation (DL) ..................................................... 527 Traffic and Pilot C/N Calculation (DL)....................................................................................... 530 Traffic and Pilot C/(I+N) and Bearer Calculation (DL) .............................................................. 532 Traffic Signal Level Calculation (UL) ........................................................................................ 534 Traffic Noise Calculation (UL)................................................................................................... 535 Traffic Interference Calculation (UL)......................................................................................... 536 Traffic Interference Signal Levels Calculation (UL)............................................................. 536 Noise Rise Calculation (UL) ................................................................................................ 537 Traffic C/N Calculation (UL)...................................................................................................... 537 Traffic C/(I+N) and Bearer Calculation (UL) ............................................................................. 541 Throughput Calculation .................................................................................................................. 544 Calculation of Total Cell Resources.......................................................................................... 544 Calculation of Sampling Frequency .................................................................................... 544 Calculation of Symbol Duration........................................................................................... 545 Calculation of Total Cell Resources - TDD Networks ......................................................... 545 Calculation of Total Cell Resources - FDD Networks ......................................................... 547 Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation .......... 547 AT283_TRG_E2

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9.3.8 9.3.8.1 9.3.8.2 9.3.9 9.3.9.1 9.3.9.2 9.3.9.3 9.4 9.4.1 9.4.2 9.4.3 9.4.3.1 9.4.3.2 9.4.3.3 9.4.4 9.4.4.1 9.4.4.2 9.4.4.3

10 10.1 10.1.1 10.1.2 10.1.3 10.1.4 10.1.4.1 10.1.4.2 10.1.4.3 10.1.4.4 10.1.4.5 10.1.4.6 10.1.4.7 10.1.4.8 10.1.4.9 10.1.4.10 10.1.4.11 10.1.5 10.1.5.1 10.1.5.2 10.1.5.3 10.1.6 10.1.6.1 10.2 10.2.1 10.2.2 10.2.3 10.2.4 10.2.4.1 10.2.4.1.1 10.2.4.1.2 10.2.4.1.3 10.2.4.2 10.2.4.2.1 10.2.4.2.2 10.2.5 10.2.5.1 10.2.5.2 10.2.5.3 10.2.5.3.1 10.2.5.3.2 10.2.5.3.3 10.2.6 10.2.7 10.2.7.1 10.2.7.1.1 10.2.7.1.2 10.2.7.2

18

Scheduling and Radio Resource Management...............................................................................551 Scheduling and Radio Resource Allocation ..............................................................................551 User Throughput Calculation.....................................................................................................557 Smart Antenna Models....................................................................................................................558 Downlink Beamforming .............................................................................................................559 Uplink Beamforming ..................................................................................................................560 Uplink Beamforming and Interference Cancellation (MMSE) ....................................................562 Automatic Allocation Algorithms ...........................................................................................................563 Automatic Neighbour Allocation ......................................................................................................563 Automatic Inter-Technology Neighbour Allocation ..........................................................................566 Automatic Frequency Planning .......................................................................................................568 Separation Constraint and Relationship Weights ......................................................................569 Calculation of Cost Between TBA and Related Cells ................................................................569 AFP Algorithm ...........................................................................................................................571 Automatic Preamble Index Allocation .............................................................................................571 Constraint and Relationship Weights ........................................................................................572 Calculation of Cost Between TBA and Related Cells ................................................................573 Automatic Allocation Algorithm..................................................................................................575

LTE Networks ................................................................................579 Definitions and Formulas ......................................................................................................................579 Input ................................................................................................................................................579 Downlink Transmission Powers Calculation ...................................................................................582 Co- and Adjacent Channel Overlaps Calculation............................................................................584 Signal Level and Signal Quality Calculations..................................................................................585 Signal Level Calculation (DL) ....................................................................................................585 Noise Calculation (DL) ..............................................................................................................586 Interference Calculation (DL) ....................................................................................................586 C/N Calculation (DL) .................................................................................................................587 C/(I+N) Calculation (DL) ............................................................................................................587 Signal Level Calculation (UL) ....................................................................................................588 Noise Calculation (UL) ..............................................................................................................589 Interference Calculation (UL) ....................................................................................................589 Noise Rise Calculation (UL) ......................................................................................................589 C/N Calculation (UL) .................................................................................................................590 C/(I+N) Calculation (UL) ............................................................................................................590 Throughput Calculation ...................................................................................................................590 Calculation of Downlink Cell Resources....................................................................................590 Calculation of Uplink Cell Resources ........................................................................................591 Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation...........592 Scheduling and Radio Resource Management...............................................................................593 User Throughput Calculation.....................................................................................................594 Calculation Processes ..........................................................................................................................594 Point Analysis: Profile Tab ..............................................................................................................594 Point Analysis: Reception Tab ........................................................................................................595 Point Analysis: Interference Tab .....................................................................................................595 Downlink Reference Signal Level Coverage Predictions ................................................................595 Coverage Area Determination...................................................................................................596 All Servers ...........................................................................................................................596 Best Signal Level and a Margin ...........................................................................................596 Second Best Signal Level and a Margin..............................................................................596 Coverage Display ......................................................................................................................596 Coverage Resolution ...........................................................................................................596 Display Types ......................................................................................................................596 Effective Signal Analysis Coverage Predictions..............................................................................597 Coverage Area Determination...................................................................................................598 Coverage Parameter Calculation ..............................................................................................598 Coverage Display ......................................................................................................................598 Coverage Resolution ...........................................................................................................598 Effective Signal Analysis (DL) Display Types ......................................................................598 Effective Signal Analysis (UL) Display Types ......................................................................600 Calculations on Subscriber Lists .....................................................................................................600 Monte Carlo Simulations .................................................................................................................601 Generating a Realistic User Distribution ...................................................................................601 Simulations Based on User Profile Traffic Maps and Subscriber Lists................................601 Simulations Based on Sector Traffic Maps..........................................................................603 Simulation Process....................................................................................................................604

AT283_TRG_E2

© Forsk 2010

Table of Contents

10.2.8 10.2.8.1 10.2.8.2 10.2.8.3 10.2.8.3.1 10.2.8.3.2 10.2.8.3.3 10.2.8.3.4 10.2.8.3.5 10.2.8.3.6 10.2.8.3.7 10.2.8.3.8 10.2.8.3.9 10.3 10.3.1 10.3.2 10.3.2.1 10.3.2.2 10.3.2.3 10.3.2.4 10.3.3 10.3.3.1 10.3.3.2 10.3.3.3 10.3.3.4 10.3.3.5 10.3.3.6 10.3.3.7 10.3.3.8 10.3.3.8.1 10.3.3.8.2 10.3.3.9 10.3.3.10 10.3.4 10.3.5 10.3.6 10.3.6.1 10.3.6.1.1 10.3.6.1.2 10.3.6.2 10.3.7 10.3.7.1 10.3.7.2 10.4 10.4.1 10.4.2 10.4.3 10.4.3.1 10.4.3.2 10.4.3.3 10.4.4 10.4.4.1 10.4.4.2 10.4.4.3

11 11.1 11.1.1 11.1.2 11.1.3 11.1.4 11.1.5 11.2 11.2.1 11.2.2 11.3 11.3.1 11.3.2 © Forsk 2010

C/(I+N)-Based Coverage Predictions ............................................................................................. 607 Coverage Area Determination .................................................................................................. 607 Coverage Parameter Calculation.............................................................................................. 607 Coverage Display ..................................................................................................................... 609 Coverage Resolution .......................................................................................................... 609 Coverage by C/(I+N) Level (DL) Display Types.................................................................. 609 Coverage by Best Bearer (DL) Display Types .................................................................... 610 Coverage by Throughput (DL) Display Types..................................................................... 610 Coverage by Quality Indicator (DL) Display Types ............................................................. 611 Coverage by C/(I+N) Level (UL) Display Types.................................................................. 611 Coverage by Best Bearer (UL) Display Types .................................................................... 611 Coverage by Throughput (UL) Display Types..................................................................... 612 Coverage by Quality Indicator (UL) Display Types ............................................................. 613 Calculation Algorithms ......................................................................................................................... 613 Downlink Transmission Powers Calculation................................................................................... 613 Co- and Adjacent Channel Overlaps Calculation ........................................................................... 617 Conversion From Channel Numbers to Start and End Frequencies ........................................ 618 Co-Channel Overlap Calculation .............................................................................................. 618 Adjacent Channel Overlap Calculation ..................................................................................... 619 Total Overlap Ratio Calculation ................................................................................................ 620 Signal Level and Signal Quality Calculations ................................................................................. 620 Signal Level Calculation (DL) ................................................................................................... 620 Noise Calculation (DL).............................................................................................................. 623 Interference Calculation (DL).................................................................................................... 624 C/N Calculation (DL)................................................................................................................. 628 C/(I+N) and Bearer Calculation (DL) ........................................................................................ 630 Signal Level Calculation (UL) ................................................................................................... 634 Noise Calculation (UL).............................................................................................................. 636 Interference Calculation (UL).................................................................................................... 636 Interfering Signal Level Calculation (UL)............................................................................. 637 Noise Rise Calculation (UL) ................................................................................................ 638 C/N Calculation (UL)................................................................................................................. 639 C/(I+N) and Bearer Calculation (UL) ........................................................................................ 641 Best Server Determination ............................................................................................................. 644 Service Area Calculation ................................................................................................................ 645 Throughput Calculation .................................................................................................................. 646 Calculation of Total Cell Resources.......................................................................................... 646 Calculation of Downlink Cell Resources ............................................................................. 646 Calculation of Uplink Cell Resources .................................................................................. 648 Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation .......... 649 Scheduling and Radio Resource Management .............................................................................. 652 Scheduling and Radio Resource Allocation.............................................................................. 652 User Throughput Calculation .................................................................................................... 658 Automatic Allocation Algorithms........................................................................................................... 659 Automatic Neighbour Allocation ..................................................................................................... 659 Automatic Inter-Technology Neighbour Allocation ......................................................................... 661 Automatic Frequency Planning ...................................................................................................... 663 Separation Constraint and Relationship Weights ..................................................................... 664 Calculation of Cost Between TBA and Related Cells ............................................................... 664 AFP Algorithm........................................................................................................................... 667 Automatic Physical Cell ID Allocation............................................................................................. 667 Constraint and Relationship Weights........................................................................................ 667 Calculation of Cost Between TBA and Related Cells ............................................................... 668 Automatic Allocation Algorithm ................................................................................................. 671

Repeaters and Remote Antennas................................................. 675 UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE Documents......................................................... 675 Signal Level Calculation ................................................................................................................. 675 Downlink Total Gain Calculation .................................................................................................... 677 Uplink Total Gain Calculation ......................................................................................................... 678 Repeater Noise Figure ................................................................................................................... 680 Appendix: Carrier Power and Interference Calculation .................................................................. 680 GSM Documents.................................................................................................................................. 683 Signal Level Calculation ................................................................................................................. 683 EIRP Calculation ............................................................................................................................ 684 Donor-side Parameter Calculations ..................................................................................................... 686 Azimuth .......................................................................................................................................... 686 Mechanical Downtilt ....................................................................................................................... 686 AT283_TRG_E2

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Technical Reference Guide

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AT283_TRG_E2

© Forsk 2010

Chapter 1 Coordinate Systems and Units

Chapter 1: Coordinate Systems and Units

1

Coordinate Systems and Units

1.1

Coordinate Systems A map or a geo-spatial database is a flat representation of data collected from a curved surface. A projection is a means for producing all or part of a spheroid on a flat sheet. This projection cannot be done without distortion. Therefore, the cartographer must choose the characteristic (distance, direction, scale, area, or shape) that he wants to be shown accurately at the expense of the other characteristics, or compromise on several characteristics [1-3]. The projected zones are referenced using cartographic coordinates (meter, yard, etc.). Two projection methods are widely used: •

•

The Lambert Conformal-Conic Method: A portion of the earth is mathematically projected on a cone conceptually secant at one or two standard parallels. This projection method is useful for representing countries or regions that have a predominant east-west expanse. The Universal Transverse Mercator (UTM) Method: A portion of the earth is mathematically projected on a cylinder tangent to a meridian (which is transverse or crosswise to the equator). This projection method is useful for mapping large areas that are oriented north-south.

The geographic system is not a projection. It is only a representation of a location on the surface of the earth in geographic coordinates (degree-minute-second, grade) giving the latitude and longitude in relation to the meridian origin (e.g., Paris for NTF system and Greenwich for ED50 system). The locations in the geographic system can be converted into other projections.

References: [1] Snyder, John. P., Map Projections Used by the US Geological Survey, 2nd Edition, United States Government Printing Office, Washington, D.C., 313 pages, 1982. [2] http://www.colorado.edu/geography/gcraft/notes/gps/gps_f.html [3] http://www.posc.org/Epicentre.2_2/DataModel/ExamplesofUsage/eu_cs34.html [4] http://www.ign.fr/telechargement/Pi/SERVICES/transfo.pdf (Document in French)

1.1.1

Description of Coordinate Systems A Geographic coordinate system is a latitude and longitude coordinate system. The latitude and longitude are related to an ellipsoid, a geodetic datum, and a prime meridian. The geodetic datum provides the position and orientation of the ellipsoid relative to the earth. Cartographic coordinate systems are obtained by transforming each (latitude, longitude) value into an (easting, northing) value. A projection coordinate system is obtained by transforming each (latitude, longitude) value into an (easting, northing) value. Projection coordinate systems are geographic coordinate systems that provide longitude and latitude, and the transformation method characterised by a set of parameters. Different methods may require different sets of parameters. For example, the parameters required for Transverse Mercator coordinate systems are: • • • • •

The longitude of the natural origin (central meridian) The latitude of the natural origin The False Easting value The False Northing value A scaling factor at the natural origin (central meridian)

Basic definitions are presented below.

1.1.1.1

Geographic Coordinate System The geographic coordinate system is a datum and a meridian. Atoll enables you to choose the most suitable geographic coordinate system for your geographic data.

1.1.1.2

Datum The datum consists of the ellipsoid and its position relative to the WGS84 ellipsoid. In addition to the ellipsoid, translation, rotation, and distortion parameters define the datum.

1.1.1.3

Meridian The standard meridian is Greenwich, but some geographic coordinate systems are based on other meridians. These meridians are defined by the longitude with respect to Greenwich.

1.1.1.4

Ellipsoid The ellipsoid is the pattern used to model the earth. It is defined by its geometric parameters.

© Forsk 2010

AT283_TRG_E2

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Technical Reference Guide

1.1.1.5

Projection The projection is the transformation applied to project the ellipsoid of the earth on to a plane. There are different projection methods that use specific sets of parameters.

1.1.1.6

Projection Coordinate System The projection coordinate system is the result of the application of a projection to a geographic coordinate system. It associates a geographic coordinate system and a projection. Atoll enables you to choose the projection coordinate system matching your geographic data.

1.1.2

Coordinate Systems in Atoll Depending on the working environment, there can be either two or four coordinate systems used in Atoll. If you are working with stand-alone documents, i.e., documents not connected to databases, there are two coordinate systems used in Atoll: • •

Projection coordinate system Display coordinate system

If you are working in a multi-user environment, Atoll uses four coordinate systems: • • • •

1.1.2.1

Projection coordinate system for the Atoll document Display coordinate system for the Atoll document Internal projection coordinate system for the database Internal display coordinate system for the database

Projection Coordinate System The projection coordinate system is the coordinate system of the available raster geographic data files. You should set the projection coordinate system of your Atoll document so that it corresponds to the coordinate system of the available raster geographic data. You can set the projection coordinate system of your document in the Options dialog. All the raster geographic data files that you want to import and use in an Atoll document must have the same coordinate system. You cannot work with raster geographic data files with different coordinate systems in the same document. Note: •

If you import vector geographic data (e.g., traffic, measurements, etc.) with different coordinate systems, it is possible to convert the coordinate systems of these data into the projection coordinate system of your Atoll document.

The projection coordinate system is used to keep the coordinates of sites (radio network data) consistent with the geographic data. When you import a raster geographic data file, Atoll reads the geo-referencing information from the file (or from its header file, depending on the geographic data file format), i.e., its Northwest pixel, to determine the coordinates of each pixel. Atoll does not use any coordinate system during the import process. However, the geo-referencing information of geographic data files are considered to be provided in the projection coordinate system of the document.

1.1.2.2

Display Coordinate System The display coordinate system is the coordinate system used for the display, e.g., in dialogs, in the Map window rulers, in the status bar, etc. The coordinates of each pixel of geographic data are converted to the display coordinate system from the projection coordinate system for display. The display coordinate system is also used for sites (radio network data). You can set the display coordinate system of your document in the Options dialog. If you import sites data, the coordinate system of the sites must correspond to the display coordinate system of your Atoll document. If you change the display coordinate system in a document which is not connected to a database, the coordinates of all the sites are converted to the new display system. Note: •

1.1.2.3

If the coordinate systems of all your geographic data files and sites (radio network data) are the same, you do not have to define the projection and display coordinate systems separately. By default, the two coordinate systems are the same.

Internal Coordinate Systems The internal coordinate systems are the projection and the display coordinate systems stored in a database. The projection and display coordinate systems set by the administrator in the central Atoll project are stored in the database when the database is created, and cannot be modified by users. Only the administrator can modify the internal coordinate systems manually by editing the entries in the CoordSys and the Units tables. All Atoll documents opened from a database will have the internal coordinate systems of the database as their default projection and display coordinate systems.

24

AT283_TRG_E2

3DF 01955 6980 RKZZA© Forsk 2010

Chapter 1: Coordinate Systems and Units When exporting an Atoll project to a database, the currently chosen display coordinate system becomes the internal display coordinate system for the database, and the currently chosen projection coordinate system becomes the internal projection coordinate system for the database. Although Atoll stores both the coordinate systems in the database, i.e., the projection and the display coordinate systems, the only relevant coordinate system for the database is the internal display coordinate system because this coordinate system is the one used for the coordinates of sites (radio network data). Users working on documents connected to a database can modify the coordinate systems in their documents locally, and save these changes in their documents, but they cannot modify the coordinate systems stored in the database. If you change the display coordinate system in a document which is not connected to a database, the coordinates of all the sites are converted to the new display system. If you change the display coordinate system in a document which is connected to a database, the coordinates of all the sites are converted to the new coordinate system in the Atoll document locally but not in the database because the internal coordinate systems cannot be changed. Atoll uses the internal coordinates systems in order to keep the site coordinates consistent in the database which is usually accessed by a large number of users in a multi-user environment.

1.1.3

File Formats The Coordsystems folder located in the Atoll installation directory contains all the coordinate systems, both geographic and cartographic, offered in the tool. Coordinate systems are grouped by regions. A catalogue per region and a "Favourites" catalogue are available in Atoll. The Favourites catalogue is initially empty and can be filled by the user by adding coordinate systems to it. Each catalogue is described by an ASCII text file with .cs extension. In a .cs file, each coordinate system is described in one line. The line syntax for describing a coordinate system is:

Code = "Name of the system"; Unit Code; Datum Code; Projection Method Code, Projection Parameters; "Comments" Examples:

4230 = "ED50"; 101; 230; 1; "Europe - west" 32045 = "NAD27 / Vermont"; 2; 267; 6, -72.5, 42.5, 500000, 0, 0.9999643; "United States - Vermont" You should keep the following points in mind when editing or creating .cs files: •

The identification code enables Atoll to differentiate coordinates systems. In case you create a new coordinate system, its code must be an integer value higher than 32767. When describing a new datum, you must enter the ellipsoid code and parameters instead of the datum code in brackets. There can be 3 to 7 parameters defined in the following order: Dx, Dy, Dz, Rx, Ry, Rz, S. The syntax of the line in the .cs file will be:

•

Code = "Name of the system"; Unit Code; {Ellipsoid Code, Dx, Dy, Dz, Rx, Ry, Rz, S}; Projection Method Code, Projection Parameters; "Comments" •

There can be up to seven projection parameters. These parameters must be ordered according to the parameter index (see "Projection Parameter Indices" on page 28). Parameter with index 0 is the first one. Projection parameters are delimited by commas. For UTM projections, you must provide positive UTM zone numbers for north UTM zones and negative numbers for south UTM zones. You can add all other information as comments (such as usage or region).

• •

Codes of units, data, projection methods, and ellipsoids, and projection parameter indices are listed in the tables below.

1.1.3.1

Unit Codes Code

© Forsk 2010

Cartographic Units

Code

0

Metre

100

Radian

1

Kilometre

101

Degree

2

Foot

102

Grad

3

Link

103

ArcMinute

4

Chain

104

ArcSecond

5

Yard

6

Nautical mile

7

Mile

-1

Unspecified

-1

Unspecified

AT283_TRG_E2

Geographic Units

25

Technical Reference Guide

1.1.3.2

26

Datum Codes Code

Datum

Code

121

Greek Geodetic Reference System 1987

260

Manoca

125

Samboja

261

Merchich

126

Lithuania 1994

262

Massawa

130

Moznet (ITRF94)

263

Minna

131

Indian 1960

265

Monte Mario

201

Adindan

266

M'poraloko

202

Australian Geodetic Datum 1966

267

North American Datum 1927

203

Australian Geodetic Datum 1984

268

NAD Michigan

204

Ain el Abd 1970

269

North American Datum 1983

205

Afgooye

270

Nahrwan 1967

206

Agadez

271

Naparima 1972

207

Lisbon

272

New Zealand Geodetic Datum 1949

208

Aratu

273

NGO 1948

209

Arc 1950

274

Datum 73

210

Arc 1960

275

Nouvelle Triangulation Française

211

Batavia

276

NSWC 9Z-2

212

Barbados

277

OSGB 1936

213

Beduaram

278

OSGB 1970 (SN)

214

Beijing 1954

279

OS (SN) 1980

215

Reseau National Belge 1950

280

Padang 1884

216

Bermuda 1957

281

Palestine 1923

217

Bern 1898

282

Pointe Noire

218

Bogota

283

Geocentric Datum of Australia 1994

219

Bukit Rimpah

284

Pulkovo 1942

221

Campo Inchauspe

285

Qatar

222

Cape

286

Qatar 1948

223

Carthage

287

Qornoq

224

Chua

288

Loma Quintana

225

Corrego Alegre

289

Amersfoort

226

Cote d'Ivoire

290

RT38

227

Deir ez Zor

291

South American Datum 1969

228

Douala

292

Sapper Hill 1943

229

Egypt 1907

293

Schwarzeck

230

European Datum 1950

294

Segora

231

European Datum 1987

295

Serindung

232

Fahud

296

Sudan

233

Gandajika 1970

297

Tananarive 1925

234

Garoua

298

Timbalai 1948

235

Guyane Francaise

299

TM65

236

Hu Tzu Shan

300

TM75

237

Hungarian Datum 1972

301

Tokyo

238

Indonesian Datum 1974

302

Trinidad 1903

239

Indian 1954

303

Trucial Coast 1948

240

Indian 1975

304

Voirol 1875

241

Jamaica 1875

305

Voirol Unifie 1960

242

Jamaica 1969

306

Bern 1938

243

Kalianpur

307

Nord Sahara 1959

244

Kandawala

308

Stockholm 1938

245

Kertau

309

Yacare

247

La Canoa

310

Yoff

248

Provisional South American Datum 1956

311

Zanderij

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Chapter 1: Coordinate Systems and Units

Code

1.1.3.3

1.1.3.4

Datum

Code

Datum

249

Lake

312

Militar-Geographische Institut

250

Leigon

313

Reseau National Belge 1972

251

Liberia 1964

314

Deutsche Hauptdreiecksnetz

252

Lome

315

Conakry 1905

253

Luzon 1911

322

WGS 72

254

Hito XVIII 1963

326

WGS 84

255

Herat North

901

Ancienne Triangulation Française

256

Mahe 1971

902

Nord de Guerre

257

Makassar

903

NAD 1927 Guatemala/Honduras/Salvador (Panama Zone)

258

European Reference System 1989

Projection Method Codes Code

Projection Method

Code

Projection Method

0

Undefined

8

Oblique Stereographic

1

No projection > Longitude / Latitude

9

New Zealand Map Grid

2

Lambert Conformal Conical 1SP

10

Hotine Oblique Mercator

3

Lambert Conformal Conical 2SP

11

Laborde Oblique Mercator

4

Mercator

12

Swiss Oblique Cylindrical

5

Cassini-Soldner

13

Oblique Mercator

6

Transverse Mercator

14

UTM Projection

7

Transverse Mercator South Oriented

Ellipsoid Codes Code

© Forsk 2010

Name

Major Axis

Minor Axis

1

Airy 1830

6377563.396

6356256.90890985

2

Airy Modified 1849

6377340.189

6356034.44761111

3

Australian National Spheroid

6378160

6356774.71919531

4

Bessel 1841

6377397.155

6356078.96261866

5

Bessel Modified

6377492.018

6356173.50851316

6

Bessel Namibia

6377483.865

6356165.38276679

7

Clarke 1858

6378293.63924683

6356617.98173817

8

Clarke 1866

6378206.4

6356583.8

9

Clarke 1866 Michigan

6378693.7040359

6357069.45104614

10

Clarke 1880 (Benoit)

6378300.79

6356566.43

11

Clarke 1880 (IGN)

6378249.2

6356515

12

Clarke 1880 (RGS)

6378249.145

6356514.86954978

13

Clarke 1880 (Arc)

6378249.145

6356514.96656909

14

Clarke 1880 (SGA 1922)

6378249.2

6356514.99694178

15

Everest 1830 (1937 Adjustment)

6377276.345

6356075.41314024

16

Everest 1830 (1967 Definition)

6377298.556

6356097.5503009

17

Everest 1830 (1975 Definition)

6377301.243

6356100.231

18

Everest 1830 Modified

6377304.063

6356103.03899315

19

GRS 1980

6378137

6356752.31398972

20

Helmert 1906

6378200

6356818.16962789

21

Indonesian National Spheroid

6378160

6356774.50408554

22

International 1924

6378388

6356911.94612795

23

International 1967

6378160

6356774.71919530

24

Krassowsky 1940

6378245

6356863.01877305

25

NWL 9D

6378145

6356759.76948868

26

NWL 10D

6378135

6356750.52001609

27

Plessis 1817

6376523

6355862.93325557

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1.1.3.5

1.1.4

Code

Name

Major Axis

Minor Axis

28 29

Struve 1860

6378297

6356655.84708038

War Office

6378300.583

6356752.27021959

30

WGS 84

6378137

6356752.31398972

31

GEM 10C

6378137

6356752.31398972

32

OSU86F

6378136.2

6356751.51667196

33

OSU91A

6378136.3

6356751.61633668

34

Clarke 1880

6378249.13884613

6356514.96026256

35

Sphere

6371000

6371000

Projection Parameter Indices Index

Projection Parameter

Index

Projection Parameter

0

UTM zone number

4

Scale factor at origin

0

Longitude of origin

4

Latitude of 1st parallel

1

Latitude of origin

5

Azimuth of central line

2

False Easting

5

Latitude of 2nd parallel

3

False Northing

6

Angle from rectified to skewed grid

Creating a Coordinate System Atoll provides a large catalogue of default coordinate systems. Nevertheless, it is possible to add the description of geographic and cartographic coordinate systems. New coordinate systems can be created from scratch or initialised on the basis of an existing one. To create a new coordinate system from scratch: 1. Select Tools > Options. The Options dialogue opens. 2. Select the Coordinates tab. 3. Click the browse button (...) on the right of the Projection field. 4. Click the New button. The Coordinate System dialog opens. 5. In the Coordinate System dialogue: a. Select the coordinate systems catalogue to which you want to add the new coordinate system. b. In the General properties section: Enter a name for the new coordinate system, select a unit. You can also enter any comments about its usage. Atoll assigns the code automatically. c. In the Category section: Select the type of coordinate system. Enter the longitude and latitude for a geographic coordinate system, or the type of projection and its set of associated parameters for a cartographic coordinate system (false easting and northing, and the first and second parallels). d. In the Geo section: Specify the meridian and choose a datum for the coordinate system. The associated ellipsoid is automatically selected. You can also describe a geodetic datum by selecting "..." in the Datum list. In this case, you must provide parameters (Dx, Dy, Dz, Rx, Ry, Rz, and S) needed for the transformation of the datum into WGS84, and an ellipsoid. 6. Click OK. The new coordinate system is added to the selected coordinate system catalogue. To create a new coordinate system based on an existing system, select a coordinate system in the Coordinate Systems dialog before clicking New in step 4. The new coordinate system is initialised with the values of the selected coordinate system.

1.2

Units

1.2.1

Power Units Depending on the working environment, there can be either one or two types of units for transmission and reception powers. If you are working with stand-alone documents, i.e., documents not connected to databases, there is only one unit used in Atoll: •

Display power units

If you are working in a multi-user environment, Atoll uses two type of units: • •

28

Display power units for the Atoll document Internal power units for the database

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Chapter 1: Coordinate Systems and Units The display units are used for the display in dialogs and tables, e.g., reception thresholds (coverage prediction properties, etc.), and received signal levels (measurements, point analysis, coverage predictions, etc.). You can set the display units for your document in the Options dialog. The internal units are the power units stored in a database. The power units set by the administrator in the central Atoll project are stored in the database when the database is created, and cannot be modified by users. Only the administrator can modify the internal units manually by editing the entries in the Units tables. All Atoll documents opened from a database will have the internal units of the database as their default power units. Users working on documents connected to a database can modify the units in their documents locally, and save these changes in their documents, but they cannot modify the units stored in the database.

1.2.2

Length Units There are two types of units for distances, heights, and offsets: • •

Display length units Internal length units

The display length units are used to display distances, heights, and offsets in dialogs, tables, and the status bar. You can set the display units for your document in the Options dialog. The internal unit for lengths is metre for all Atoll documents whether they are connected to databases or not. The internal unit is not stored in the databases. The internal unit cannot be changed.

1.3

BSIC Format Depending on the working environment, there can be either one or two types of BSIC formats. If you are working with stand-alone documents, i.e., documents not connected to databases, there is only one BSIC format: •

Display BSIC format

If you are working in a multi-user environment, Atoll uses two type of formats: • •

Display BSIC format for the Atoll document Internal BSIC format for the database

The display format is used for the display in dialogs and tables. You can set the display format for your document from the Transmitters folder’s context menu. The internal format is the BSIC format stored in a database. The BSIC format set by the administrator in the central Atoll project is stored in the database when the database is created, and cannot be modified by users. Only the administrator can modify the internal format manually by editing the corresponding entry in the Units tables. All Atoll documents opened from a database will have the internal format of the database as their default BSIC format. Users working on documents connected to a database can modify the format in their documents locally, and save this change in their documents, but they cannot modify the format stored in the database.

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Chapter 2 Geographic and Radio Data

Chapter 2: Geographic and Radio Data

2

Geographic and Radio Data

2.1

Geographic Data

2.1.1

Data Type Atoll manages several geographic data types; DTM (Digital Terrain Model), clutter (Land-Use), scanned images, vector data, traffic data, population, and any other generic data.

2.1.1.1

Digital Terrain Model (DTM) The DTM (Digital Terrain Model or height) files describe the ground elevation above the sea level. DTM files supported by Atoll are 16 bits/pixel relief maps in .tif, .bil, Planet© and Erdas Imagine formats and 8 bits/pixel relief maps in .tif, .bil, Erdas Imagine and .bmp formats. DTM maps are taken into account in path loss calculations by Atoll propagation models. DTM file provides altitude value (z stated 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 stated in metre). Pixel size must be the same in both directions. First point given in the file corresponds to the centre of the upper-left pixel of the map. This point refers to the northwest point geo-referenced by Atoll. Four points (hence, four altitude values) are necessary to describe a “bin”; these points are bin vertices.

Figure 2.1Digital Terrain Model Therefore, a n*n bin DTM file requires (n)2 points (altitude values).

Figure 2.2Schematic view of a DTM file Notes:

© Forsk 2010

•

Altitude values differ within a bin. Method used to calculate altitudes is described in the Path loss calculations: Altitude determination part. Concerning DTM map display, Atoll takes altitude of the southwest point of each bin to determine its colour.

•

In most documents, Digital Elevation Model (DEM) and Digital Terrain Model (DTM) are differentiated and do not have the same meaning. By definition, DEM refers to altitude above sea level including, both, ground and clutter while DTM just corresponds to the ground height above sea level. In Atoll, the DEM term may be used instead of DTM term.

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2.1.1.2

Clutter (Land Use) You may import two types of clutter files in ATL documents. These files indicate either the clutter class or the clutter height on each bin of the map.

2.1.1.2.1

Clutter Classes Atoll supports 8 bits/pixel (255 classes) raster maps in .tif, .bil, .bmp, Erdas Imagine formats or 16 bits/pixel raster maps in Planet© format. This kind of clutter file describes the land cover (dense urban, buildings, residential, forest, open, villages, …). A grid map represents ground and each bin of the map is characterised by a code corresponding to a main type of cover (a clutter class). Atoll automatically lists all the clutter classes of the map. It is possible to specify an average clutter height for each clutter class manually during the map description step. Clutter maps are taken into account in path loss calculations by Atoll propagation models. Clutter file provides a clutter code per bin. Bin size is defined by pixel size (P stated in metre). Pixel size must be the same in both directions. Abscissa and ordinate axes are respectively oriented in right and downwards directions. First point given in the file corresponds to the centre of the upper-left pixel of the image. This point refers to the northwest point georeferenced by Atoll.

Figure 2.3Clutter Classes Therefore, a n*n bin Clutter file requires (n)2 code values. Note: •

2.1.1.2.2

The clutter code is the same inside a bin.

Clutter Heights Files supported by Atoll for clutter heights are 8 or 16 bits/pixel raster maps in .tif, .bil and Erdas Imagine formats. The file provides clutter height value 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. First point given in the file corresponds to the centre of the upper-left pixel of the map. This point refers to the northwest point geo-referenced by Atoll. These maps are taken into account in path loss calculations by Atoll propagation models. Note: •

2.1.1.3

Atoll considers the clutter height of the nearest point in calculations (see Path loss calculations: Clutter determination part). For map display, Atoll takes clutter height of the southwest point of each bin to determine its colour.

Traffic Data Atoll offers different kinds of traffic data:

2.1.1.3.1

User Profile Environment Based Traffic Maps Atoll supports 8 bits/pixel (256 class) traffic raster maps in .tif, .bil, .bmp, Erdas Imagine formats. These maps provide macroscopic traffic estimation. Each pixel is assigned an environment class, which is a list of user profiles with a defined mobility type and a density.

2.1.1.3.2

User Profile Traffic Maps Atoll supports vector traffic maps with .dxf®, Planet©, .shp, .mif and .agd formats. These maps are detailed traffic estimations (lines, polygons or points carrying a specific traffic). Each polygon, line or point is assigned a specific user profile with associated mobility type and density. They can be built from population density vector maps.

2.1.1.3.3

Sector Traffic Maps Atoll supports maps with .agd format. This kind of map is based on the network feedback. It provides actual information on connections (and not just subscriber estimation) from the network. It is built from a coverage by transmitter prediction

34

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Chapter 2: Geographic and Radio Data study that defines sector boundaries for the traffic distribution in each sector. In UMTS and CDMA, either data rates or the number of users per service are indicated for each transmitter service area. In GSM/TDMA, Atoll expects a number of Erlangs in case of voice service and data rate values for packet-switched services for each transmitter service area.

2.1.1.3.4

User Density Traffic Maps This kind of map is only available in GSM/TDMA documents. Atoll supports 16 and 32 bits/pixel traffic raster maps in .tif, .bil, .bmp, Planet© and Erdas Imagine formats. This map is also based on the network feedback as it deals with network users information as well. Each pixel is assigned a number of users with a given service, terminal and mobility type. In GSM documents, traffic maps are taken into account for traffic analysis and network dimensioning. In UMTS and CDMA documents, they are used by the Monte-Carlo simulator to model user distributions and evaluate related network parameters (cell power, mobile terminal power, …).

2.1.1.4

Vector Data These data represent either polygons (regions, etc.), lines (roads, coastlines, etc.) or points (towns, etc.). Atoll supports vector data files in .dxf®, Planet©, .shp, .mif and .agd formats. These maps are only used for display and provide information about the geographic environment.

2.1.1.5

Scanned Images These geographic data include the road maps and the satellite images. They are only used for display and provide information about the geographic environment. Atoll supports scanned image files in .tif (1, 4, 8, 24-bits/pixel), .bil (1, 4, 8, 24-bits/pixel), Planet© (1, 4, 8, 24-bits/pixel), .bmp (1-24-bits/pixel), Erdas Imagine (1, 4, 8, 24-bits/pixel) and .ecw (24bits/pixel) formats.

2.1.1.6

Population Atoll deals with vector population files (polygons, lines or points) in .mif, .shp and .agd formats or 8, 16, 32 bits/pixel raster population files in .tif, .bil, .bmp and Erdas Imagine formats. Population map describes the population distribution. They are considered in clutter statistics and in coverage prediction reports.

2.1.1.7

Other Geographic Data It is possible to import generic geographic data types, other than those listed above, (Customer density, revenue density, etc.) in Atoll. These data can be either vector files in .mif, .shp and .agd formats or 8, 16, 32 bits/pixel raster files in .tif, .bil, .bmp and Erdas Imagine formats. These maps are taken into account in clutter statistics and in coverage prediction reports. The ArcView Grid format (.txt) is an ASCII format dedicated to define raster maps. It may be used to export any raster map such as DTM, images, Clutter Classes and/or Heights, Population, Generic data maps and even coverage predictions. The contents of an ArcView Grid file are in ASCII and consist of a header, describing the content, followed by the content in the form of cell values. Notes:

2.1.2

•

The minimum resolution supported by Atoll is 1m for any raster maps, excepted for scanned images, for which it is unlimited.

•

DTM and clutter map resolution must be an integer.

•

All the raster maps you want to import in an ATL document must be represented in the same projection system.

Supported Geographic Data Formats Atoll offers Import/Export filters for the most commonly used geographic data formats. The different filters are:

© Forsk 2010

File format

Import/ Export

Can contain

Georeferenced

.bil

Both

DTM, Clutter classes and heights, Traffic, Image, Population, Other data

Yes via .hdr files

.tif

Both

DTM, Clutter classes and heights, Traffic, Image, Population, Other data

Yes via associated .tfw files if they exist

Planet©

Both

DTM, Clutter classes, Image, Vector data

Yes via index files

.bmp

Both

DTM, Clutter heights, Clutter classes, Traffic, Image, Population, Other data

Yes via .bpw (or .bmw) files

.dxf®

Import Only

Vector data, Vector traffic

Yes

.shp

Both

Vector data, Vector traffic, Population, Other data

Yes

.mif/.mid

Both

Vector data, Vector traffic, Population, Other data

Yes

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Technical Reference Guide

Erdas Imagine

Import Only

DTM, Clutter classes and heights, Traffic, Image, Population, Other data

Yes

ArcView Grid

Export Only

DTM, Clutter classes and heights, Traffic, Image, Population, Other data

Yes automatically embedded in the data file

.agd

Both

Vector data, Vector traffic, Population, Other data

Yes automatically embedded in the data file

Vertical Mapper (.grd, .grc)

Both

DTM, Clutter classes and heights, Traffic, Image, Population, Other data

Yes automatically embedded in the data file

.ecw

Import Only

Images

Yes via ers file (not mandatory)

Note: •

The .wld files may be used as georeferencement file for any type of binary raster file.

•

Tiled .tif format is not supported.

Thus, to sum up, you can import: • • • • • • • •

DTM files in .tif (16-bits, 8-bits), .bil (16-bits, 8-bits), Planet© (16-bits), Erdas Imagine (16-bits, 8-bits), Vertical Mapper (.grd, .grc) and .bmp (8-bits) formats. Clutter heights files in .tif (16-bits, 8-bits), .bil (16-bits, 8-bits), Erdas Imagine (16-bits, 8-bits), Vertical Mapper (.grd, .grc) and .bmp (8-bits) formats. Clutter classes and traffic raster files in .tif (8-bits), .bil (8-bits), .bmp (8-bit), Erdas Imagine (8-bits) and Vertical Mapper (.grd, .grc) and Planet© format (16-bits) are also supported. Vector data files in .dxf®, Planet©, .shp, .mif and .agd formats. Vector traffic files in .dxf®, Planet©, .shp, .mif and .agd formats. Scanned image files in .tif (1, 4, 8, 24-bits), .bil (1, 4, 8, 24-bits), Planet© (1, 4, 8, 24-bits), .bmp (1-24-bits), Erdas Imagine (1, 4, 8, 24-bits), Vertical Mapper (.grd, .grc) and .ecw (Enhanced Compressed Wavelet) (24 bits) formats. Population files in .mif, .shp, .agd, .tif (8, 16, 32-bits), .bil (8, 16, 32-bits), .bmp (8, 32-bits), Vertical Mapper (.grd, .grc) and Erdas Imagine (8, 16, 32-bits) formats. Other generic data types in .mif, .shp, .agd, .tif (8, 16, 32-bits), .bil (8, 16, 32-bits), .bmp (8, 32-bits), Vertical Mapper (.grd, .grc) and Erdas Imagine (8, 16, 32-bits) formats. Note: •

2.2

It is possible to import Packbit, FAX-CCITT3 and LZW compressed .tif files. However, in case of DTM and clutter, we recommend not to use compressed files in order to avoid poor performances. If uncompressed files are too big, it is better to split them.

Radio Data Atoll manages several radio data types; sites, transmitters, antennas, stations and hexagonal designs. Data definition in Atoll is detailed hereafter.

2.2.1

Site A site is a geographical point where one or several transmitters (multi-sectored site or station) equipped with antennas are located.

2.2.2

Antenna An antenna is a device used for transmitting or receiving electromagnetic waves.

2.2.3

Transmitter A transmitter is a group of radio devices located at a site. Transmitters are equipped with antenna(s) and other equipment such as feeder, tower mounted amplifiers (TMA) and BTS.

2.2.4

Repeater A repeater is a device that receives, amplifies and transmits the radiated or conducted RF carrier both in downlink and uplink. It comprises a donor side and a server side. The donor side receives the signal from a donor transmitter. This signal may be carried by different types of links such as radio link, microwave link, or optic fibre. The server side transmits the repeated signal.

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Chapter 2: Geographic and Radio Data

2.2.5

Remote Antenna The use of remote antennas allows antenna positioning at locations that would normally require prohibitively long runs of feeder cable. A remote antenna is connected to the base station via an optic fibre. The main difference from a repeater is that a remote antenna generates its own cell whereas a repeater extends the coverage of an existing cell.

2.2.6

Station A station can represent one transmitter on a site or a group of transmitters on a same site sharing the same properties. You can define station templates and build your network from stations instead of single transmitters.

2.2.7

Hexagonal Design A hexagonal design is a group of stations created from the same station template.

2.2.8

GSM GPRS EGPRS Documents

2.2.8.1

TRX A base station (transmitter) consists of several transceivers or TRXs. One TRX supports as many timeslots as the multiplexing factor defined in properties of your frequency band (8 timeslots in GSM networks). Three types of TRXs are modelled in Atoll: • • •

2.2.8.2

The BCCH TRX type: carries the BCCH, The TCH TRX type: which is the default traffic carrier, The TCH_INNER TRX type: this TRX type is an inner traffic carrier.

Subcell A subcell corresponds to a group of TRXs having the same radio characteristics, the same quality (C/I) requirements, and common settings. A subcell is characterised by the ‘transmitter-TRX type’ pair. Each transmitter may have one or more subcells. The most common configurations are the {BCCH, TCH} configuration or the {BCCH, TCH, TCH_INNER} one.

2.2.8.3

Cell Type A cell type describes the subcells (types of TRXs) that a cell can use and their parameters, which can be different. In the current Atoll version, the cell type definition must include a TRX type as the BCCH carrier (BCCH TRX type) and another TRX type as the default traffic carrier (TCH TRX type). Only one TRX type carrying the broadcast and only one TRX type carrying the default TCH are supported.

2.2.9

All CDMA, WiMAX, and LTE Documents

2.2.9.1

Cell Cell comprises the carrier characteristics of a transmitter. Cell is characterised by the ‘transmitter-carrier’ pair. The transmitter-carrier pair must be unique.

© Forsk 2010

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Chapter 3 File Formats

Chapter 3: File Formats

3

File Formats

3.1

BIL Format Band Interleaved by Line is a method of organizing image data for multi-band images. It is a schema for storing the actual pixel values of an image in a file. The pixel data is typically preceded by a file header that contains auxiliary data about the image, such as the number of rows and columns in the image, a colour map, etc. .bil data stores pixel information band by band for each line, or row, of the image. Although .bil is a data organization schema, it is treated as an image format. An image description (number of rows and columns, number of bands, number of bits per pixel, byte order, etc.) has to be provided to be able to display the .bil file. This information is included in the header .hdr file associated with the .bil file. A .hdr file has the same name as the .bil file it refers to, and should be located in the same directory as the source file. The .hdr structure is simple; it is an ASCII text file containing eleven lines. You can open a .hdr file using any ASCII text editor. Atoll supports the following objects in .bil format: • • • • • • • •

Digital Terrain Model (8 or 16 bits) Clutter heights (8 or 16 bits) Clutter classes and User profile environment based traffic maps (8 bits) User density traffic maps (16 or 32 bits) Raster images (1, 4, 8, 24 bits) Population maps (8, 16, 32 bits) Other generic geographic data (8, 16, 32 bits) Path loss or received signal level value matrices (16 bits)

3.1.1

HDR Header File

3.1.1.1

Description The header file is a text file that describes how data are organised in the .bil file. The header file is made of rows, each row having the following format:

keywordvalue where ‘keyword’ corresponds to an attribute type, and ‘value’ defines the attribute value. Keywords required by Atoll are described below. Other keywords are ignored.

nrows Number of rows in the image. ncols Number of columns in the image. nbandsNumber of spectral bands in the image, (1 for DTM data and 8 bit pictures). nbits Number of bits per pixel per band; 8 or 16 for DTMs or Clutter heights (altitude in metres), 8 for clutter classes file (clutter code), 16 for path loss matrices (path loss in dB, field value in dBm, dBµV and DBµV/m). byteorderByte order in which image pixel values are stored. Accepted values are M (Motorola byte order) or I (Intel byte order). layoutMust be ‘bil’. skipbytesByte to be skipped in the image file in order to reach the beginning of the image data. Default value is 0. ulxmapx coordinate of the centre of the upper-left pixel. ulymapy coordinate of the centre of the upper-left pixel. xdim x size in metre of a pixel. ydim y size in metre of a pixel. Four additional keywords may be optionally managed.

pixeltypeType of data read (in addition to the length) which can be : UNSIGNDINT

Undefined

8, 16, 24 or 32 bits

SIGNEDINT

Integer

16 or 32 bits

FLOAT

Real

32 or 64 bits

in some cases, this keyword can be replace by datatype defined as follows:

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datatypeType of data read (in addition to the length) It can be: Un

Undefined

n bits (8, 16, 24 or 32 bits)

In

Integer

n bits (16 or 32 bits)

Rn

Real

n bits (32 or 64 bits)

RGB24

Integer

3 colour components on 24 bits

The other optional keywords are :valueoffset, valuescale and nodatavalue. By default, integer data types are chosen with respect to the pixel length (nbits).

valueoffsetReal value to be added to the read value (Vread) valuescaleScaling factor to be applied to the read value So, we have V = V read  valuescale + valueoffset

nodatavalueValue corresponding to “NO DATA”

3.1.1.2

Samples Here, the data is 20m.

3.1.1.2.1

Digital Terrain Model nrows 1500 ncols 1500 nbands1 nbits 8 or 16 byteorderM layoutbil skipbytes0 ulxmap975000 ulymap1891000 xdim 20.00 ydim 20.00

3.1.1.2.2

Clutter Classes File nrows 1500 ncols 1500 nbands1 nbits 8 byteorderM layoutbil skipbytes0 ulxmap975000 ulymap1891000 xdim 20.00 ydim 20.00

3.1.1.2.3

BIL File .bil files are usually binary files without header. Data are stored starting from the Northwest corner of the area. The skipbytes value defined in the header file allows to skip records if the data do not start at the beginning of the file.

3.2

TIF Format start here Tagged Image File Format graphics filter supports all image types (monochrome, greyscale, palette colour, and RGB full colour images) and Packbit, LZW or fax group 3-4 compressions. .tif files are not systematically geo-referenced. You have

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Chapter 3: File Formats to enter spatial references of the image manually during the import procedure (x and y-axis map coordinates of the centre of the upper-left pixel, pixel size); an associated file with .tfw extension will be simultaneously created with the same name and in the same directory as the .tif file it refers to. Atoll will then use the .tfw file during the import procedure for an automatic geo-referencing. Note: •

Atoll also supports .tif files using the Packbit, FAX-CCITT3 and LZW compression modes.

You can modify the colour palette convention used by Atoll when exporting .tif files. This can be helpful when working on .tif files exported by Atoll in other tools. In the default palette, the first colour indexes represent the useful information and the remaining colour indexes represent the background. It is possible to export .tif files with a palette which defines the background colour at the colour index 0, and then the colour indexes necessary to represent useful information. Add the following lines in the Atoll.ini file to set up the new palette convention:

[TiffExport] PaletteConvention=Gis Please refer to the Administrator Manual for more details about the Atoll.ini file. Notes: •

Using compressed geo data formats (compressed .tif, Erdas Imagine, or .ecw) can cause performance loss due to real-time decompression. However, you can recover this loss in performance by: - Either, hiding the status bar, which provides geographic data information in real time, by unchecking the Status Bar item in the View menu. - Or, not displaying some of the information, such as altitude, clutter class and clutter height, in the status bar. This can be done through the Atoll.ini file, by adding the following lines: [StatusBar] DisplayZ=0 DisplayClutterClass=0 DisplayClutterHeight=0

•

You can also save the produced map in an uncompressed format.

•

Please refer to the Administrator Manual for more details about the Atoll.ini file.

Atoll supports the following objects in .tif format: • • • • • • •

Digital Terrain Model (8 or 16 bits) Clutter heights (8 or 16 bits) Clutter classes and User profile environment based traffic maps (8 bits) User density traffic maps (16 or 32 bits) Raster images (1, 4, 8, 24 bits) Population maps (8, 16, 32 bits) Other generic geographic data (8, 16, 32 bits)

.tfw file contains the spatial reference data of an associated .tif file. The .tfw file structure is simple; it is an ASCII text file that contains six lines. You can open a .tfw file using any ASCII text editor.

3.2.1

TFW Header File The .tfw files contain spatial reference data for the associated .tif file. The header file is a text file that describes how data are organised in the .tif file. You can open a .tfw file using any ASCII text editor. The header file consists of six lines, with each line having the following description: Line

Description

1

x dimension of a pixel in map units

2

amount of translation

3

amount of rotation

4

negative of the y dimension of a pixel in map units

5

x-axis map coordinate of the centre of the upper-left pixel

6

y-axis map coordinate of the centre of the upper-left pixel

Note: •

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Atoll does not use the lines 2 and 3 when importing a .tif format geographic file.

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3.2.2

Sample

3.2.2.1

Clutter Classes File 100.00 0.00 0.00 -100.00 60000.00 2679900.00

3.3

BMP Format This is the MS-Windows standard format. It holds black & white, 16-, 256- and True-colour images. The palletized 16colour and 256-colour images may be compressed via run length encoding (though compressed .bmp files are quite rare). The image data itself can either contain pointers to entries in a colour table or literal RGB values. .bmp files are not systematically geo-referenced. You have to enter spatial references of the image manually during the import procedure (x and y-axis map coordinates of the centre of the upper-left pixel, pixel size). When exporting (saving) a .bmp file, an associated file with .bpw extension is created with the same name and in the same directory as the .bmp file it refers to. Atoll stores the georeferencing information in this file for future imports of the .bmp so that the .bpw file can be used during the import procedure for automatic geo-referencing. Atoll also supports .bmw extension for the .bmp related world files. Atoll supports the following objects in .bmp format: • • • • • •

3.3.1

Digital Terrain Model (8 bits) Clutter Heights (8 bits) Clutter classes and User density traffic maps (8 bits) Raster images (1, 4, 8, 24 bits) Population maps (8, 32 bits) Other generic geographic data (8, 32 bits)

BMP File Description A .bmp file contains of the following data structures: •

• • •

3.3.1.1

BITMAPFILEHEADER

bmfh Contains some information about the bitmap file (about the file, not about the bitmap itself). BITMAPINFOHEADER bmih Contains information about the bitmap (such as size, colours, etc.). RGBQUAD aColors[] Contains a colour table. BYTE aBitmapBits[] Image data (whose format is specified by the bmih structure).

BMP File Structure The following tables give exact information about the data structures. The Start-value is the position of the byte in the file at which the explained data element of the structure starts, the Size-value contains the number of bytes used by this data element, the Name column contains both generic name and the name assigned to this data element by the Microsoft API documentation, and the Description column gives a short explanation of the purpose of this data element. •

Name

Start

Size

1

2

3

4

7

2

9

2

Reserved2

bfReserved2

Unused. Must be set to zero.

bfOffBits

Specifies the offset from the beginning of the file to the bitmap (raster) data.

11

•

Start

44

BITMAPFILEHEADER (Header - 14 bytes):

4

Description

Generic

MS API

Signature

bfType

Must always be set to 'BM' to declare that this is a .bmp-file.

FileSize

bfSize

Specifies the size of the file in bytes.

Reserved1

bfReserved1

Unused. Must be set to zero.

DataOffset

BITMAPINFOHEADER (InfoHeader - 40 bytes):

Size

Name Generic

MS API AT283_TRG_E2

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15

4

Size

biSize

Specifies the size of the BITMAPINFOHEADER structure, in bytes (= 40 bytes).

19

4

Width

biWidth

Specifies the width of the image, in pixels.

23

4

Height

biHeight

Specifies the height of the image, in pixels.

biPlanes

Specifies the number of planes of the target device, must be set to zero or 1.

biBitCount

Specifies the number of bits per pixel. 1 = monochrome pallete. # of colours = 1 4 = 4-bit palletized. # of colours = 16 8 = 8-bit palletized. # of colours = 256 16 = 16-bit palletized. # of colours = 65536 24 = 24-bit palletized. # of colours = 16M

27

29

2

Planes

2

BitCount

31

4

Compression

biCompression

Specifies the type of compression, usually set to zero. 0 = BI_RGB no compression 1 = BI_RLE8 8-bit RLE encoding 2 = BI_RLE4 4-bit RLE encoding

35

4

ImageSize

biSizeImage

Specifies the size of the image data, in bytes. If there is no compression, it is valid to set this element to zero.

39

4

XpixelsPerM

biXPelsPerMeter

Specifies the the horizontal pixels per meter.

43

4

YpixelsPerM

biYPelsPerMeter

Specifies the the vertical pixels per meter.

47

4

ColoursUsed

biClrUsed

Specifies the number of colours actually used in the bitmap. If set to zero the number of colours is calculated using the biBitCount element.

51

4

ColoursImportant

biClrImportant

Specifies the number of colour that are 'important' for the bitmap. If set to zero, all colours are considered important.

Note: •

•

biBitCount actually specifies the colour resolution of the bitmap. It also decides if there is a colour table in the file and how it looks like. - In 1-bit mode the colour table has to contain 2 entries (usually white and black). If a bit in the image data is clear, it points to the first palette entry. If the bit is set, it points to the second. - In 4-bit mode the colour table must contain 16 colours. Every byte in the image data represents two pixels. The byte is split into the higher 4 bits and the lower 4 bits and each value of them points to a palette entry. - In 8-bit mode every byte represents a pixel. The value points to an entry in the colour table which contains 256 entries. - In 24-bit mode three bytes represent one pixel. The first byte represents the red part, the second the green and the third the blue part. There is no need for a palette because every pixel contains a literal RGB-value, so the palette is omitted.

RGBQUAD array (ColorTable):

Name

Start

Size

1

1

Blue

rgbBlue

Specifies the blue part of the colour.

2

1

Green

rgbGreen

Specifies the green part of the colour.

3

1

Red

rgbRed

Specifies the red part of the colour.

4

1

Reserved

rgbReserved

Must always be set to zero.

Generic

Description

MS API

Note: •

•

In a colour table (RGBQUAD), the specification for a colour starts with the blue byte, while in a palette a colour always starts with the red byte.

Pixel data:

The interpretation of the pixel data depends on the BITMAPINFOHEADER structure. It is important to know that the rows of a .bmp are stored upside down meaning that the uppermost row which appears on the screen is actually the lowermost row stored in the bitmap. Another important thing is that the number of bytes in one row must always be adjusted by appending zero bytes to fit into the border of a multiple of four (16-bit or 32-bit rows).

3.3.1.2

BMP Raster Data Encoding Depending on the image BitCount and on the Compression flag there are 6 different encoding schemes. In all of them, • •

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For uncompressed formats every line will have the same number of bytes. Colour indices are zero based, meaning a pixel colour of 0 represents the first colour table entry, a pixel colour of 255 (if there are that many) represents the 256th entry. For images with more than 256 colours there is no colour table.

Encoding type

BitCoun Compressio t n

1-bit B&W images

1

4

0

Every byte holds 2 pixels, its high order 4 bits representing the left of those. There are 16 colour table entries. These colours do not have to be the 16 MS-Windows standard colours. Padding each line with zeros up to a 32-bit boundary will result in up to 28 zeros = 7 'wasted pixels'.

8-bit 256 colour images

8

0

Every byte holds 1 pixel. There are 256 colour table entries. Padding each line with zeros up to a 32-bit boundary will result in up to 3 bytes of zeros = 3 'wasted pixels'.

16-bit High colour images

16

0

Every 2 bytes hold 1 pixel. There are no colour table entries. Padding each line with zeros up to a 16-bit boundary will result in up to 2 zero bytes.

0

Every 4 bytes hold 1 pixel. The first holds its red, the second its green, and the third its blue intensity. The fourth byte is reserved and should be zero. There are no colour table entries. No zero padding necessary.

2

Pixel data is stored in 2-byte chunks. The first byte specifies the number of consecutive pixels with the same pair of colour. The second byte defines two colour indices. The resulting pixel pattern will have interleaved high-order 4-bits and low order 4 bits (ABABA...). If the first byte is zero, the second defines an escape code. The End-of-Bitmap is zero padded to end on a 32-bit boundary. Due to the 16bit-ness of this structure this will always be either two zero bytes or none.

1

The pixel data is stored in 2-byte chunks. The first byte specifies the number of consecutive pixels with the same colour. The second byte defines their colour indices. If the first byte is zero, the second defines an escape code. The End-of-Bitmap is zero padded to end on a 32-bit boundary. Due to the 16bit-ness of this structure this will always be either two zero bytes or none.

24

4-bit 16 colour images

4

8-bit 256 colour images

8

Raster Data Compression Descriptions •

4-bit / 16 colour images

n (Byte 1)

•

c (Byte 2)

Description

>0

any

n pixels to be drawn. The 1st, 3rd, 5th, ... pixels' colour is in c's high-order 4 bits, the even pixels' colour is in c's low-order 4 bits. If both colour indices are the same, it results in just n pixels of colour c.

0

0

End-of-line

0

1

End-of-Bitmap

0

2

Delta. The following 2 bytes define an unsigned offset in x and y direction (y being up). The skipped pixels should get a colour zero.

0

>=3

The following c bytes will be read as single pixel colours just as in uncompressed files. Up to 12 bits of zeros follow, to put the file/memory pointer on a 16-bit boundary again.

8-bit / 256 colour images

n (Byte 1)

c (Byte 2)

Description

>0

any

n pixels of colour number c

0

0

End-of-line

0

1

End-of-Bitmap

2

Delta. The following 2 bytes define an unsigned offset in x and y direction (y being up). The skipped pixels should get a colour zero.

0

46

0

Every byte holds 8 pixels, its highest order bit representing the leftmost pixel of these 8. There are 2 colour table entries. Some readers assume that 0 is black and 1 is white. If you are storing black and white pictures you should stick to this, with any other 2 colours this is not an issue. Remember padding with zeros up to a 32-bit boundary.

4-bit 16 colour images

24-bit True colour images

3.3.1.2.1

Remarks

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0

3.3.2

>=3

The following c bytes will be read as single pixel colours just as in uncompressed files. A zero follows, if c is odd, putting the file/memory pointer on a 16-bit boundary again.

BPW/BMW Header File Description The header file is a text file that describes how data are organised in the .bmp file. The header file is made of rows, each row having the following description: Line

Description

1

x dimension of a pixel in map units

2

amount of translation

3

amount of rotation

4

negative of the y dimension of a pixel in map units

5

x-axis map coordinate of the centre of the upper-left pixel

6

y-axis map coordinate of the centre of the upper-left pixel

Atoll supports .bpw and .bmw header file extensions for Import, but exports headers with .bpw file extensions.

3.3.3

Sample

3.3.3.1

Clutter Classes File 100.00 0.00 0.00 -100.00 60000.00 2679900.00

3.4

PNG Format Portable Network Graphics (PNG) is a bitmapped image format that employs lossless data compression. PNG supports palette-based (palettes of 24-bit RGB or 32-bit RGBA colors), greyscale, RGB, or RGBA images. PNG was designed for transferring images on the Internet, not professional graphics, and so does not support other color spaces (such as CMYK). PNG files nearly always use file extension .PNG or .png. When exporting (saving) a .png file, an associated file with .pgw extension is created with the same name and in the same directory as the .png file it refers to. Atoll stores the georeferencing information in this file for future imports of the .png so that the .pgw file can be used during the import procedure for automatic geo-referencing. For more information on the PNG file format, see www.w3.org/TR/PNG/.

3.4.1

PGW Header File Description A PNG World file (.pgw file extension) is a plain text file used by geographic information systems (GIS) to provide georeferencing information for raster map images in .png format. The world file parameters are: Line

3.5

Description

1

x dimension of a pixel in map units

2

amount of translation

3

amount of rotation

4

negative of the y dimension of a pixel in map units

5

x-axis map coordinate of the centre of the upper-left pixel

6

y-axis map coordinate of the centre of the upper-left pixel

Generic Raster Header File (.wld) .wld is a new Atoll specific header format that can be used for any raster data file for georeferencing. At the time of import of any raster data file, Atoll can use the corresponding .wld file to read the georeferencing information related to the raster data file. The .wld file contains the spatial reference data of any associated raster data file. The .wld file structure is simple; it is an ASCII text file containing six lines. You can open a .wld file using any ASCII text editor.

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3.5.1

WLD File Description The .wld file is a text file that describes how data are organised in the associated raster data file. The header file is made of rows, each row having the following description: Line

Description

1

x dimension of a pixel in map units

2

amount of translation

3

amount of rotation

4

negative of the y dimension of a pixel in map units

5

x-axis map coordinate of the centre of the upper-left pixel

6

y-axis map coordinate of the centre of the upper-left pixel

3.5.2

Sample

3.5.2.1

Clutter Classes File 100.00 0.00 0.00 -100.00 60000.00 2679900.00

3.6

DXF Format Atoll is capable of importing and working with AutoCAD® drawings in the Drawing Interchange Format (DXF). .dxf files can have ASCII or binary formats. But only the ASCII .dxf files can be used in Atoll. .dxf files are composed of pairs of codes and associated values. The codes, known as group codes, indicate the type of value that follows. .dxf files are organized into sections of records containing the group codes and their values. Each group code and value is a separate line. Each section starts with a group code 0 followed by the string, SECTION. This is followed by a group code 2 and a string indicating the name of the section (for example, HEADER). Each section ends with a 0 followed by the string ENDSEC.

3.7

SHP Format ESRI (Environmental Systems Research Institute, Inc.) ArcView® GIS Shapefiles have a simple, non-topological format for storing geometric locations and attribute information of geographic features. A shapefile is one of the spatial data formats that you can work with in ArcExplorer. .shp data files usually have associated .shx and .dbf files. Among these three files: • • •

The .shp file stores the feature geometry The .shx file stores the index of the feature geometry. The .dbf (dBASE) file stores the attribute information of features. When a shapefile is added as a theme to a view, this file is displayed as a feature table.

You can define mappings between the coordinate system used for the ESRI vector files, defined in the corresponding .prj files, and Atoll. In this way, when you import a vector file, Atoll can detect the correct coordinate system automatically. For more information about defining the mapping between coordinate systems, please refer to the Administrator Manual.

3.8

MIF Format MapInfo Interchange Format (.mif) allows various types of data to be attached to a variety of graphical items. These ASCII files are editable, easy to generate, and work on all platforms supported by MapInfo. Vector objects with a .mif extension may be imported in Atoll. Two files, a .mif and a .mid, contain MapInfo data. Graphics reside in the .mif file while the text contents are stored in the .mid file. The text data is delimited with one row per record, and Carriage Return, Carriage Return plus Line Feed, or Line Feed between lines. The .mif file has two sections, the file header and the data section. The .mid file is optional. When there is no .mid file, all fields are blank. You can find more information at http://www.mapinfo.com.

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Chapter 3: File Formats You can define mappings between the coordinate system used for the MapInfo vector files, defined in the corresponding .mif files, and Atoll. In this way, when you import a vector file, Atoll can detect the correct coordinate system automatically. For more information about defining the mapping between coordinate systems, please refer to the Administrator Manual.

3.9

TAB Format TAB files (MapInfo Tables) are the native format of MapInfo. They actually consist of a number of files with extensions such as .TAB, .DAT and .MAP. All of these files need to be present and kept together for the table to work. These are defined as follows: • • • • •

.TAB: table structure in ASCII format .DAT: table data storage in binary format .MAP: storage of map objects in binary format .ID: index to the MapInfo graphical objects (.MAP) file .IND: index to the MapInfo tabular (DAT) file

You can find more information at http://www.mapinfo.com. You can define mappings between the coordinate system used for the MapInfo vector files, defined in the corresponding .mif files, and Atoll. In this way, when you import a vector file, Atoll can detect the correct coordinate system automatically. For more information about defining the mapping between coordinate systems, please refer to the Administrator Manual. TAB files are also supported as georeference information files for raster files (.bmp and .tif). The .TAB file must have the following format:

!table !version 300 !charset WindowsLatin1 Definition Table File "raster.bmp" Type "RASTER" (ulxmap,ulymap) (0,0) Label "Pt 1", (llxmap,llymap) (0,nrows) Label "Pt 2", (lrxmap,lrymap) (ncols,nrows) Label "Pt 3", (urxmap,urymap) (ncols,0) Label "Pt 4" The fields in bold are described below:

Field

3.10

Description

File "raster.bmp"

Name of the raster file (e.g., raster.bmp)

ulxmap

x coordinate of the centre of the upper-left pixel in metres

ulymap

y coordinate of the centre of the upper-left pixel in metres

llxmap

x coordinate of the centre of the lower-left pixel in metres

llymap

y coordinate of the centre of the lower-left pixel in metres

lrxmap

x coordinate of the centre of the lower-right pixel in metres

lrymap

y coordinate of the centre of the lower-right pixel in metres

urxmap

x coordinate of the centre of the upper-right pixel in metres

urymap

y coordinate of the centre of the upper-right pixel in metres

nrows

Number of rows in the image

ncols

Number of columns in the image

ECW Format The Enhanced Compressed Wavelet file format is supported in Atoll. .ecw files are geo-referenced image files, which can be imported in Atoll. This is an Open Standard wavelet compression technology, developed by Earth Resource Mapping, which can compress images with up to a 100-to-1 compression ratio. Each compressed image file contains a header carrying the following information about the image: • • • • • •

© Forsk 2010

The image size expressed as the number of cells across and down The number of bands (RGB images have three bands) The image compression rate The cell measurement units (meters, degrees or feet) The size of each cell in measurement units Coordinate space information (Projection, Datum etc.)

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3.11

Erdas Imagine Format Atoll supports Erdas Imagine data files in order to import DTM (8 or 16 bit/pixel), clutter (8 bit/pixel), traffic (8 bit/pixel), and image (1-24 bit/pixel) files with the .img format. These files use the Erdas Imagine Hierarchical File Format (HFA) structure. For any type of file, if there are pyramids (storage of different resolution layers), they are used to enhance performance when decreasing the resolution of the display. Some aspects of working with Erdas Imagine format in Atoll are: • • • •

Atoll supports uncompressed as well as compressed (or partially compressed) DTM .img files. You can create a .mnu file to improve the clutter class map loading. The colour-to-code association (raster maps) may be automatically imported from the .img file. These files are automatically geo-referenced, i.e., they do not require any additional file for geo-reference.

For image files, the number of supported bands is either 1 (colour palette is defined separately) or 3 (no colour palette but direct RGB information for each pixel). In case of 3 bands, only 8 bit per pixel format is supported. Therefore, 8-bit images, containing RGB information (three bands are provided: the first band is for Blue, the second one is for Green and the third for Red), can be considered as 24 bit per pixel files. 32 bit per pixel files are not supported. Notes: •

Using compressed geo data formats (compressed .tif, Erdas Imagine, or .ecw) can cause performance loss due to real-time decompression. However, you can recover this loss in performance by: - Either, hiding the status bar, which provides geographic data information in real time, by unchecking the Status Bar item in the View menu. - Or, not displaying some of the information, such as altitude, clutter class and clutter height, in the status bar. This can be done through the Atoll.ini file, by adding the following lines: [StatusBar] DisplayZ=0 DisplayClutterClass=0 DisplayClutterHeight=0

3.12

•

You can also save the produced map in an uncompressed format.

•

Please refer to the Administrator Manual for more details about the Atoll.ini file.

Planet EV/Vertical Mapper Geographic Data Format Vertical Mapper offers two types of grids: • •

Numerical continuous grids, which contain numerical information (such as DTM), and are stored in files with the .grd extension. Classified grids, which contain alphanumeric (characters) information, and are stored in files with the .grc extension.

Atoll is capable of supporting the Vertical Mapper Classified Grid (GRC) and Vertical Mapper Continuous Grid (GRD) file formats in order to import and export: • •

GRD: DTM, image, population, traffic density, and other data types. GRC: DTM, clutter classes, clutter heights, environment traffic, image, population, and other data types.

It is also possible to export coverage prediction studies in GRD and GRC formats. This is the geographic data format used by Planet EV. So, it is possible to directly import geographic data from Planet EV to Atoll using this format.

3.13

ArcView Grid Format The ArcView Grid format (.txt) is an ASCII format dedicated to defining raster maps. It may be used to export any raster map such as DTM, images, clutter classes and/or heights, population, other data maps, and even coverage predictions. The contents of an ArcView Grid file are in ASCII and consist of a header, describing the content, followed by the content in the form of cell values.

3.13.1

ArcView Grid File Description The format of this file is as follows:

ncols XXXNumber of columns of the grid (XXX columns). nrows XXXNumber of rows of the grid (XXX rows). xllcenter XXX OR xllcorner XXXSignificant value relative to the bin centre or corner.

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yllcenter OR yllcorner XXXSignificant value relative to the bin centre or corner. cellsize XXXGrid resolution. nodata_value XXXOptional value corresponding to no data (no information). //Row 1Top of the raster. Description of the first row. Syntax: ncols number of values separated by spaces. : : //Row NBottom of the raster.

3.13.2

Sample ncols 303 nrows 321 xllcorner 585300.000000 yllcorner 5615700.000000 cellsize 100.000000 nodata_value 0 ...

3.14

Other Supported Geographic Data File Formats Other than the .bil, .tif, Planet, .dxf, .shp, .mif, .img, and .ecw formats, Atoll supports 3 other formats. The .ist and .dis formats are ASCII files used for Digital Terrain Model only. .ist images come from Istar, whereas .dis images come from IGN (Institut Géographique National). The .ist format works in exactly the same way as the .bil format, except for DTM images. For DTM images, the .ist format uses a decimetric coding for altitudes, whereas .bil images use only a metric coding.

3.15

Planet Format The Planet geographic data are described by a set of files grouped in a Planet directory. The directory structure depends on the geographic data type. Atoll supports the following objects in Planet format: • • • • •

Digital Terrain Model (8 and 16 bits) Clutter class maps (16 bits) Raster images (1, 4, 8 and 24 bits) Vector data Text data

3.15.1

DTM File

3.15.1.1

Description The DTM directory consists of three files; the height file and two other files detailed below: •

The index file structure is simple; it is an ASCII text file that holds position information about the file. It contains five columns. You can open an index file using any ASCII text editor. The format of the index file is as follows:

Field

© Forsk 2010

Acceptable values

Description

File name

Text

Name of file referenced by the index file

East min

Float

x-axis map coordinate of the centre of the upper-left pixel in meters

East max

Float

x-axis map coordinate of the centre of the upper-right pixel in meters

North min

Float

y-axis map coordinate of the centre of the lower-left pixel in meters

North max

Float

y-axis map coordinate of the centre of the upper-left pixel in meters

Square size

Float

Dimension of a pixel in meters

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Technical Reference Guide •

The projection file provides information about the projection system used. This file is optional. It is an ASCII text file with four lines maximum.

Line

Description

Spheroid Zone Projection Latitude and longitude of projection central meridian and equivalent x and y coordinates in meters (optional)

Central meridian

Note: •

3.15.1.2

In the associated binary file, the value -9999 corresponds to ‘No data’ which is supported by Atoll.

Sample Index file associated with height file (DTM data):

sydney1

303900 343900 6227900 6267900 50

Projection file associated with height file (DTM data):

Australian-1965 56 UTM 0 153 500000 10000000

3.15.2

Clutter Class Files

3.15.2.1

Description The Clutter directory consists of three files; the clutter file and two other files detailed below: •

The menu file, an ASCII text file, defines the feature codes for each type of clutter. It consists of as many lines (with the following format) as there are clutter codes in the clutter data files. This file is optional.

Field

Type

Clutter-code

Integer (>1)

Identification code for clutter class

Text (up to 32 characters in length)

Name associated with the clutter-code. (It may contain spaces)

Feature-name

•

The index file gives clutter spatial references. The structure of clutter index file is the same as the structure of DTM index file. Note: •

3.15.2.2

Description

In the associated binary file, the value -9999 corresponds to ‘No data’ which is supported by Atoll.

Sample Menu file associated with the clutter file:

52

1

open

2

sea

3

inlandwater

4

residential

5

meanurban

6

denseurban

7

buildings

8

village

9

industrial

10

openinurban

11

forest AT283_TRG_E2

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Chapter 3: File Formats

12

parks

13

denseurbanhigh

14

blockbuildings

15

denseblockbuild

16

rural

17

mixedsuburban

3.15.3

Vector Files

3.15.3.1

Description Vector data comprises terrain features such as coastlines, roads, etc. Each of these features is stored in a separate vector file. Four types of files are used, the vector file, where x and y coordinates of vector paths are stored, and three other files detailed below: •

The menu file, an ASCII text file, lists the vector types stored in the database. The menu file is composed of one or more records with the following structure:

Field

Type

Description

Vector type code

Integer > 0

Identification code for the vector type

Vector type name

Text (up to 32 characters in length)

Name of the vector type

The fields are separated by space character. •

The index file, an ASCII text file, lists the vector files and associates each vector file with one vector type, and optionally with one attribute file. The index file consists of one or more records with the following structure:

Field

Type

Vector file name

Text (up to 32 characters in length)

Name of the vector file

Text (up to 32 characters in length)

Name of attribute file associated with the vector file (optional)

Dimensions

Real

vector file eastmin: minimum x-axis coordinate of all vector path points in the vector file vector file eastmax: maximum x-axis coordinate of all vector path points in the vector file vector file northmin: minimum y-axis coordinate of all vector path points in the vector file vector file northmax: maximum y-axis coordinate of all vector path points

Vector type name

Text (up to 32 characters in length)

Name of the vector type with which the vector file is associated. This one must match exactly a vector type name field in the menu file.

Attribute file name

Description

The fields are separated by spaces. •

3.15.3.2

The attribute file stores the height and description properties of vector paths. This file is optional.

Sample Index file associated with the vector files

sydney1.airport313440 333021 6239426 6244784 airport sydney1.riverlake303900 342704 6227900 6267900 riverlake sydney1.coastline322837 343900 6227900 6267900 coastline sydney1.railways303900 336113 6227900 6267900 railways sydney1.highways303900 325155 6240936 6267900 highways sydney1.majstreets303900 342770 6227900 6267900 majstreets sydney1.majorroads303900 342615 6227900 6267900 majorroads

3.15.4

Image Files The image directory consists of two files, the image file with .tif extension and an index file with the same structure as the DTM index file structure.

© Forsk 2010

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Technical Reference Guide

3.15.5

Text Data Files The text data directory consists of: •

The text data files are ASCII text files with the following format:

Airport 637111.188 3094774.00 Airport 628642.688 3081806.25 Each file contains a line of text followed by easting and northing of that text, etc. •

The index file, an ASCII text file, stores the position of each text file. It consists of one or more records with the following structure:

Field

Type

Description

File name

Text (up to 32 characters in length)

File name of the text data file

East Min

Real

Minimum x-axis coordinate of all points listed in the text data file

East Max

Real

Maximum x-axis coordinate of all points listed in the text data file

North Min

Real

Minimum y-axis coordinate of all points listed in the text data file

North Max

Real

Maximum y-axis coordinate of all points listed in the text data file

Text feature

Text (up to 32 characters in length)

This field is omitted in case no menu file is available.

The fields are separated by spaces.

railwayp.txt -260079 693937 2709348 3528665 Railway_Station airport.txt -307727 771663 2547275 3554675 Airport ferryport.txt 303922 493521 2667405 3241297 Ferryport •

The menu file, an ASCII text file, contains the text features. This file is optional.

1

Airport

2

Ferryport

3

Railway_Station

3.16

MNU Format

3.16.1

Description A .mnu file is useful when importing clutter classes or raster traffic files in .tif, .bil and .img formats. It gives the correspondence between the clutter (or traffic) code and the class name. It is a text file with the same name as the clutter (or traffic) file with .mnu extension. It must be stored at the same location as the clutter (or traffic) file. It has the same structure as the menu file used in the Planet format.

Field

Type

Description

Class code

Integer > 0

Identification code for the clutter (or traffic) class

Class name

Text (up to 50 characters in length)

Name of the clutter (or traffic) class. It may contain spaces.

Separator used can either be a space character or a tab.

3.16.2

Sample A .mnu file associated to a clutter classes file:

54

0

none

1

open

2

sea

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Chapter 3: File Formats

3.17

3

inland_water

4

residential

5

meanurban

XML Table Export/Import Format All the data tables in an Atoll document can be exported to XML files. Atoll creates the following files when exporting data tables to XML files: •

One index.xml file which contains the mapping between the data tables in Atoll and the corresponding XML file created by the export. One XML file per data table which contains the data table format (schema) and the data.

•

The XML import does not modify the active document table and field definitions. Therefore, the Networks and CustomFields tables, although exported, are not imported. The following sections describe the structures of these two types of XML files created at export.

3.17.1

Index.xml File The index.xml file stores the system (GSM, UMTS, etc.) and the technology (TDMA, CDMA, etc.) of the document, and the version of Atoll used for exporting the data tables to XML files. It also contains the mapping between the data tables in the Atoll document and the XML file corresponding to each data table. The root tag of the index.xml file contains the following attributes:

Attribute

Description

Atoll_File_System

Corresponds to the SYSTEM_ field of the Networks table of the exported document

Atoll_File_Technology

Corresponds to the TECHNOLOGY field of the Networks table of the exported document

Atoll_File_Version

Corresponds to the Atoll version

The index file also contains a list of mapping between the tables exported from Atoll and the XML files corresponding to each table. This list is sorted in the order the Atoll tables are to be imported. The list is composed of tags with the following attributes:

Attribute

Description

XML_File

Corresponds to the exported XML file name (e.g., "Sites.xml")

Atoll_Table

Corresponds to the exported Atoll table name (e.g., "Sites")

A sample extract of the index.xml is given below:

... Note that no closing tag is required.

3.17.2

XML File Atoll creates an XML file per exported data table. This XML file has two sections, one for storing the description of the table structure, and the second for the data itself. The XML file uses the standard XML rowset schema (schema included in the XML file between and tags).

Rowset Schema The XML root tag for XML files using the rowset schema is the following:



© Forsk 2010

AT283_TRG_E2

55

Technical Reference Guide The schema definition follows the root tag and is enclosed between the following tags:

and tags -> In the rowset schema, after the schema description, the data are enclosed between and . Between these tags, each record is handled by a tag having its attributes set to the record field values since in the rowset schema, values are handled by attributes. Note that no closing tag is required. A sample extract of a Sites.xml file containing the Sites table with only one site is given below:



name='NAME' rs:number='1' rs:maydefer='true' rs:basetable='Sites' rs:basecolumn='NAME'



dt:maxLength='8'

rs:precision='15'



dt:maxLength='8'

rs:precision='15'



dt:type='r4'

dt:maxLength='4'

rs:precision='7'



56

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Chapter 3: File Formats

3.18

Externalised Propagation Results Format Propagation results, i.e. the path loss matrices, may be stored in an external folder. This folder consists of a dBASE III based file named ‘pathloss.dbf’ that contains calculation parameters of all the transmitters considered and one file (or two when calculating main and extended path loss matrices) per transmitter taken into account. This is a binary file with .los extension and contains the path loss values for a transmitter. Note: •

3.18.1

Each transmitter path loss matrix is calculated on the area where calculation radius intersects the computation zone (see: Computation zone).

DBF File dBASE III file (pathloss.dbf) has a standard .dbf format described below. Its content can be checked by opening it in MSAccess. The format is detailed hereafter.

3.18.1.1

DBF File Format For general information, the format of .dbf files in any Xbase language is described. Following notations are used in tables:

FS = FlagShipD3 = dBaseIII+ Fb = FoxBaseD4 = dBaseIV Fp = FoxProD5 = dBaseV CL = Clipper

3.18.1.1.1

3.18.1.1.2

DBF Structure Byte

Description

0...n

.dbf header (see next part for size, byte 8)

n+1

1st record of fixed length (see next parts) 2nd record (see next part for size, byte10) … last record

last

optional: 0x1a (eof byte)

DBF Header (Variable Size - Depends on Field Count) Byte

Size

Contents

Description

Applies for (supported by)

00

1

0x03

plain .dbf

FS, D3, D4, D5, Fb, Fp, CL

0x04

plain .dbf

D4, D5 (FS)

0x05

plain .dbf

D5, Fp (FS)

0x43

with .dbv memo var size

FS

0xB3

with .dbv and .dbt memo

FS

0x83

with .dbt memo

FS, D3, D4, D5, Fb, Fp, CL

0x8B

with .dbt memo in D4 format

D4, D5

0x8E

with SQL table

D4, D5

0xF5

with .fmp memo

Fp

01

3

YYMMDD

Last update digits

All

04

4

ulong

Number of records in file

All

08

2

ushort

Header size in bytes

All

10

2

ushort

Record size in bytes

All

12

2

0,0

Reserved

All

14

1

0x01

Begin transaction

D4, D5

0x00

End Transaction

D4, D5

0x00

ignored

FS, D3, Fb, Fp, CL

0x01

Encrypted

D4, D5

0x00

normal visible

All

15

© Forsk 2010

If .dbf is not empty

1

16

12

0 (1)

multi-user environment use

D4,D5

28

1

0x01

production index exists

Fp, D4, D5

AT283_TRG_E2

57

Technical Reference Guide 0x00 29

30

2

32

n*32

+1

1

•

All

n

language driver ID

D4, D5

0x01

codepage437 DOS USA

Fp

0x02

codepage850 DOS Multi ling

Fp

0x03

codepage1251 Windows ANSI

Fp

0xC8

codepage1250 Windows EE

Fp

0x00

ignored

FS, D3, Fb, Fp, CL

0,0

0x0D

reserved

All

Field Descriptor, (see next paragraph)

all

Header Record Terminator

all

Field descriptor array in the .dbf header (32 bytes for each field)

Byte

Size

Contents

Description

Applies for (supported by)

0

11

ASCI

field name, 0x00 termin

all

11

1

ASCI

field type (see next paragraph)

all

12

4

n,n,n,n

Fld address in memory

D3

n,n,0,0

offset from record begin

Fp

0,0,0,0

ignored

FS, D4, D5, Fb, CL

16

1

byte

Field length, bin (see next paragraph)

all \ FS,CL: for C field type

17

1

byte

decimal count, bin

all / both used for fld lng

18

2

0,0

reserved

all

20

1

21

23

2

1

byte

Work area ID

D4, D5

0x00

unused

FS, D3, Fb, Fp, CL

n,n

multi-user dBase

D3, D4, D5

0,0

ignored

FS, Fb, Fp, CL

0x01

Set Fields

D3, D4, D5

0x00

ignored

FS, Fb, Fp, CL

24

7

0...0

reserved

all

31

1

0x01

Field is in .mdx index

D4, D5

0x00

ignored

FS, D3, Fb, Fp, CL

•

Field type and size in the .dbf header, field descriptor (1 byte)

Size

Type

Description/Storage

Applies for (supported by)

C 1...n

Char

ASCII (OEM code page chars) rest= space, not \0 term.

all

n = 1...64kb (using deci count)

FS

n = 1...32kb (using deci count)

Fp, CL

n = 1...254

all

D8

Date

8 ASCII digits (0...9) in the YYYYMMDD format

all

F 1...n

Numeric

ASCII digits (-.0123456789) variable pos. of float.point n = 1...20

FS, D4, D5, Fp

N 1...n Numeric

ASCII digits (-.0123456789) fix posit/no float.point

all

n = 1...20

FS, Fp, CL

L1

M 10

V 10

58

1

index upon demand

n = 1...18

D3, D4, D5, Fb

Logical

ASCII chars (YyNnTtFf space)

FS, D3, Fb, Fp, CL

ASCII chars (YyNnTtFf?)

D4, D5 (FS)

Memo

10 digits repres. the start block posit. in .dbt file, or 10 spaces if no entry in memo

all

Variable

Variable, bin/asc data in .dbv 4bytes bin= start pos in memo 4bytes bin= block size 1byte = subtype 1byte = reserved (0x1a) 10 spaces if no entry in .dbv

FS

AT283_TRG_E2

© Forsk 2010

Chapter 3: File Formats

3.18.1.1.3

P 10

Picture

binary data in .ftp structure like M

Fp

B 10

Binary

binary data in .dbt structure like M

D5

G 10

General

OLE objects structure like M

D5, Fp

22

short int

binary int max +/- 32767

FS

44

long int

binary int max +/- 2147483647

FS

88

double

binary signed double IEEE

FS

Each DBF Record (Fixed Length) Byte

Size

0 1…n

3.18.1.2

Description

Applies for (supported by)

1

deleted flag "*" or not deleted " "

all

1…

x-times contents of fields, fixed length, unterminated. For n, see (2) byte 10…11

All

DBF File Content The .dbf file provides information that is needed to check validity of each path loss matrix.

Field

Type

Description

TX_NAME

Text

Name of the transmitter

FILE_NAME

Text

Name (and optionally, path) of .los file

MODEL_NAME

Text

MODEL_SIG

Text

Name of propagation model used to calculate path loss Signature (identity number) of model used in calculations. You may check it in the propagation model properties (General tab). The Model_SIG is used for the purpose of validity. A unique Model_SIG is assigned to each propagation model. When model parameters are modified, the associated model ID changes. This enables Atoll to detect path loss matrix invalidity. In the same way, two identical propagation models in different projects do not have the same model IDa.

© Forsk 2010

ULXMAP

Float

X-coordinate of the top-left corner of the path loss matrix upper-left pixel

ULYMAP

Float

Y-coordinate of the top-left corner of the path loss matrix upper-left pixel

RESOLUTION

Float

Resolution of path loss matrix in metre

NROWS

Float

Number of rows in path loss matrix

NCOLS

Float

Number of columns in path loss matrix

FREQUENCY

Float

Frequency band

TILT

Float

Transmitter antenna mechanical tilt

AZIMUTH

Float

Transmitter antenna azimuth

TX_HEIGHT

Float

Transmitter height in metre

TX_POSX

Float

X-coordinate of the transmitter

TX_POSY

Float

Y-coordinate of the transmitter

ALTITUDE

Float

Ground height above sea level at the transmitter in metre

RX_HEIGHT

Float

Receiver height in metre

ANTENNA_SI

Float

Logical number referring to antenna pattern. Antennas with the same pattern will have the same number.

MAX_LOS

Float

Maximum path loss stated in 1/16 dB. This information is used, when no calculation radius is set, to check the matrix validity.

CAREA_XMIN

Float

Lowest x-coordinate of centre pixel located on the calculation radiusb

CAREA_XMAX

Float

Highest x-coordinate of centre pixel located on the calculation radius

CAREA_YMIN

Float

Lowest y-coordinate of centre pixel located on the calculation radius

CAREA_YMAX

Float

Highest y-coordinate of centre pixel located on the calculation radius

WAREA_XMIN

Float

Lowest x-coordinate of centre pixel located in the computation zonec

WAREA_XMAX

Float

Highest x-coordinate of centre pixel located in the computation zone

WAREA_YMIN

Float

Lowest y-coordinate of centre pixel located in the computation zone

WAREA_YMAX

Float

Highest y-coordinate of centre pixel located in the computation zone

AT283_TRG_E2

59

Technical Reference Guide

a.

Boolean

Locking status 0: path loss matrix is not locked 1: path loss matrix is locked.

INC_ANT

Boolean

Atoll indicates if losses due to the antenna pattern are taken into account in the path loss matrix. 0: antenna losses not taken into account 1: antenna losses included

In order to benefit from the calculation sharing feature, users must retrieve the propagation models from the same central database. This can be done using the Open from database command for a new document or the Refresh command for an existing one. Otherwise, Atoll generates different model_ID (even if same parameters are applied on the same kind of model) and calculation sharing become unavailable due to inconsistency. These coordinates enable Atoll to determine the area of calculation for each transmitter. These coordinates enable Atoll to determine the rectangle including the computation zone.

b. c.

3.18.2

LOCKED

LOS File The data file is a binary file with a standard row-column structure. Data are stored starting from the southwest to the northeast corner of the area. The file contains 16-bit signed integer values in the range [-32768; +32767] with a 1/16 dB precision. "No data" values are represented by +32767.

3.19

Externalised Tuning Files Atoll can tune path loss matrices obtained from propagation results by the use of real measurements (CW Measurements or Test Mobile Data). For each measured transmitter, Atoll tries to merge measurements and predictions on the same points and to smooth the surrounding points of the path loss matrices for homogeneity reasons. A transmitter path loss matrix can be tuned several times by the use of several measurement paths. All these tuning paths are stored in a catalogue. This catalogue is stored under a .tuning folder containing a .dbf file and one .pts file per corrected transmitter. Since a tuning file can contain several measurement paths, all these measurements are added to the tuning file. For more information on the path loss tuning algorithm, See .

3.19.1

DBF File dBASE III file (pathloss.dbf) has a standard .dbf format described below. Its content can be checked by opening it in MSAccess. The format is detailed hereafter.

3.19.1.1

DBF File Format For general information, the format of .dbf files in any Xbase language is described. Following notations are used in tables:

FS = FlagShipD3 = dBaseIII+ Fb = FoxBaseD4 = dBaseIV Fp = FoxProD5 = dBaseV CL = Clipper

3.19.1.1.1

3.19.1.1.2

60

DBF Structure Byte

Description

0...n

.dbf header (see next part for size, byte 8)

n+1

1st record of fixed length (see next parts) 2nd record (see next part for size, byte10) … last record

last

optional: 0x1a (eof byte)

If .dbf is not empty

DBF Header (Variable Size - Depends on Field Count) Byte

Size

Contents

Description

Applies for (supported by)

00

1

0x03

plain .dbf

FS, D3, D4, D5, Fb, Fp, CL

0x04

plain .dbf

D4, D5 (FS)

0x05

plain .dbf

D5, Fp (FS)

0x43

with .dbv memo var size

FS

0xB3

with .dbv and .dbt memo

FS

0x83

with .dbt memo

FS, D3, D4, D5, Fb, Fp, CL

AT283_TRG_E2

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Chapter 3: File Formats 0x8B

D4, D5

0x8E

with SQL table

D4, D5

0xF5

with .fmp memo

Fp

01

3

YYMMDD

Last update digits

All

04

4

ulong

Number of records in file

All

08

2

ushort

Header size in bytes

All

10

2

ushort

Record size in bytes

All

12

2

0,0

Reserved

All

14

1

0x01

Begin transaction

D4, D5

0x00

End Transaction

D4, D5

0x00

ignored

FS, D3, Fb, Fp, CL

0x01

Encrypted

D4, D5

0x00

normal visible

All

15

1

16

12

0 (1)

multi-user environment use

D4,D5

28

1

0x01

production index exists

Fp, D4, D5

0x00

index upon demand

All

29

1

n

language driver ID

D4, D5

0x01

codepage437 DOS USA

Fp

0x02

codepage850 DOS Multi ling

Fp

0x03

codepage1251 Windows ANSI

Fp

0xC8

codepage1250 Windows EE

Fp

0x00

ignored

FS, D3, Fb, Fp, CL

0,0

reserved

All

Field Descriptor, (see next paragraph)

all

Header Record Terminator

all

30

2

32

n*32

+1

1

•

0x0D

Field descriptor array in the .dbf header (32 bytes for each field)

Byte

Size

Contents

Description

Applies for (supported by)

0

11

ASCI

field name, 0x00 termin

all

11

1

ASCI

field type (see next paragraph)

all

12

4

n,n,n,n

Fld address in memory

D3

n,n,0,0

offset from record begin

Fp

0,0,0,0

ignored

FS, D4, D5, Fb, CL

16

1

byte

Field length, bin (see next paragraph)

all \ FS,CL: for C field type

17

1

byte

decimal count, bin

all / both used for fld lng

18

2

0,0

reserved

all

20

1

byte

Work area ID

D4, D5

0x00

unused

FS, D3, Fb, Fp, CL

21

2

n,n

multi-user dBase

D3, D4, D5

0,0

ignored

FS, Fb, Fp, CL

23

1

0x01

Set Fields

D3, D4, D5

0x00

ignored

FS, Fb, Fp, CL

24

7

0...0

reserved

all

31

1

0x01

Field is in .mdx index

D4, D5

0x00

ignored

FS, D3, Fb, Fp, CL

•

Size C 1...n

© Forsk 2010

with .dbt memo in D4 format

Field type and size in the .dbf header, field descriptor (1 byte)

Type

Description/Storage

Applies for (supported by)

Char

ASCII (OEM code page chars) rest= space, not \0 term.

all

n = 1...64kb (using deci count)

FS

n = 1...32kb (using deci count)

Fp, CL

n = 1...254

all

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Technical Reference Guide D8

Date

8 ASCII digits (0...9) in the YYYYMMDD format

all

F 1...n

Numeric

ASCII digits (-.0123456789) variable pos. of float.point n = 1...20

FS, D4, D5, Fp

N 1...n Numeric

ASCII digits (-.0123456789) fix posit/no float.point

all

n = 1...20

FS, Fp, CL

n = 1...18

D3, D4, D5, Fb

Logical

ASCII chars (YyNnTtFf space)

FS, D3, Fb, Fp, CL

ASCII chars (YyNnTtFf?)

D4, D5 (FS)

Memo

10 digits repres. the start block posit. in .dbt file, or 10 spaces if no entry in memo

all

V 10

Variable

Variable, bin/asc data in .dbv 4bytes bin= start pos in memo 4bytes bin= block size 1byte = subtype 1byte = reserved (0x1a) 10 spaces if no entry in .dbv

FS

P 10

Picture

binary data in .ftp structure like M

Fp

B 10

Binary

binary data in .dbt structure like M

D5

G 10

General

OLE objects structure like M

D5, Fp

22

short int

binary int max +/- 32767

FS

44

long int

binary int max +/- 2147483647

FS

88

double

binary signed double IEEE

FS

L1

M 10

3.19.1.1.3

Each DBF Record (Fixed Length) Byte

Size

0 1…n

3.19.1.2

Description

Applies for (supported by)

1

deleted flag "*" or not deleted " "

all

1…

x-times contents of fields, fixed length, unterminated. For n, see (2) byte 10…11

All

DBF File Content The .dbf file provides information about the measured transmitters participating in the tuning.

3.19.2

Field

Type

Description

TX_NAME

Text

Name of the transmitter

FILE_NAME

Text

Name (and optionally, path) of .pts file

AREA_XMIN

Float

Not used

AREA_XMAX

Float

Not used

AREA_YMIN

Float

Not used

AREA_YMAX

Float

Not used

PTS File The tuning file contains a header and the list of points. The contents of the header is: • • • • • • • • • • • •

62

4 bytes : version 4 bytes : flag (can be used to manage flags like active flag) 50 bytes : GUID 4 bytes : Number of points 255 bytes : original measurements name (with prefix Num : for test mobile data and CW: for CW measurements) 256 bytes : comment 4 bytes : X_RADIUS 4 bytes : Y_RADIUS 4 bytes : Gain : measurement gain - losses 4 bytes : Global error 4 bytes : Rx height 4 bytes : Frequency

AT283_TRG_E2

© Forsk 2010

Chapter 3: File Formats •

8 bytes : Tx Position

The list of points contains following 4-uplet for all points • • • •

3.20

4 bytes : X 4 bytes : Y 4 bytes : Measurement value 4 bytes : Incidence angle.

Interference Histograms File Formats Interference histograms required by automatic frequency planning tools can be imported and exported. Notes:

3.20.1

•

No validity check is carried out when importing an interference histogram file.

•

Atoll only imports interference histograms related to loaded transmitters.

•

The lines starting with the symbol "#" are considered as comments.

•

The interferer TRX type is not specified. In fact, the subcells of the interferer transmitter differ by their power offsets. If the power offset of a subcell is X with respect to the BCCH, then its interference C/I histogram will be shifted by X with respect to the BCCH interference histogram. It contains no further information; therefore, the interferer TRX type is always BCCH.

•

For each interfered subcell-interferer subcell pair, Atoll saves probabilities for several C/I values (between 6 to 24 values). Five of these values are fixed; probabilities are calculated for C/I values equal to –9, 1, 8, 14, and 22 dB. Then, between each fixed C/I value, there can be up to three additional values (this number depends on the probability variation between the fixed values). The C/I values have 0.5 dB accuracy and probability values are calculated and stored with an accuracy of 0.002 for probabilities between 1 and 0.05, and with an accuracy of 0.0001 for probabilities lower than 0.05.

•

If no power offset is defined on the Interfered TRX type, it is possible to use the "All" value.

•

The values of probability should be absolute (between 0 and 1), and not in precentage (between 0 and 100%).

One Histogram per Line (.im0) Format This file contains one histogram per line for each interfered/interfering subcell pair. The histogram is a list of C/I values with associated probabilities. The .im0 file consists of two parts: •

The first part is a header used for format identification. It must start with and contain the following lines:

# Calculation Results Data File. # Version 1.1, Tab separated format. Commented lines start with #. •

The second part details interference histogram of each interfered subcell-interferer subcell pair.

The lines after the header are considered as comments if they start with the symbol "#". If not, they must have the following format:

The 4 tab-separated columns are defined in the table below:

3.20.1.1

Column name

Description

Column1

Interfered transmitter

Name of the interfered transmitter.

Column2

Interfering transmitter

Name of the interferer transmitter.

Column3

Interfered TRX type

Interfered subcell. In order to save storage, all subcells with no power offset are not duplicated (e.g. BCCH, TCH).

Column4

C/I Probability

C/I value and the probability associated to this value separated by a space character. This entry cannot be null.

Sample # Calculation Results Data File. # Version 1.1, Tab separated format. Commented lines start with #. # Remark:

© Forsk 2010

C/I results do not incorporate power offset values.

AT283_TRG_E2

63

Technical Reference Guide

# Fields are: #-----------------------------------------------------------------------#Transmitter

Interferer

TRX type

{C/I Probability} values

#-----------------------------------------------------------------------# # Warning, The parameter settings of this header can be wrong if # the "export" is performed following an "import". They # are correct when the "export" follows a "calculate". # # Service Zone Type is "Best signal level of the highest priority HCS layer". # Margin is 5. # Cell edge coverage probability 75%. # Traffic spreading was Uniform ##---------------------------------------------------------------------# # Site0_2

Site0_1

BCCH,TCH-10 1 -9 0.996 -6 0.976 -4 0.964 -1 0.936 0 0.932 1 0.924 4 0.896 7 0.864 8 0.848 9 0.832 10 0.824 11 0.804 14 0.712 17 0.66

Site0_2

Site0_3

BCCH,TCH-10 1 -9 0.996 -6 0.976 -4 0.972 -1 0.948 0 0.94 1 0.928 4 0.896 7 0.856 8 0.84 11 0.772 13 0.688 14 0.636 15 0.608 18 0.556

Site0_3

Site0_1

BCCH,TCH-10 1 -9 0.996 -6 0.98 -3 0.948 0 0.932 1 0.924 4 0.892 7 0.852 8 0.832 9 0.816 10 0.784 11 0.764 14 0.644 15 0.616 18 0.564

Site0_3

Site0_2

BCCH,TCH-9 1 -6 0.972 -3 0.964 -2 0.96 0 0.94 1 0.932 4 0.904 7 0.876 8 0.86 9 0.844 11 0.804 13 0.744 14 0.716 15 0.692 18 0.644

3.20.2

One Value per Line with Dictionary File (.clc) Format Atoll creates two ASCII text files in a specified directory: xxx.dct and xxx.clc (xxx is the user-specified name). Note: •

3.20.2.1

CLC File

3.20.2.1.1

Description

When importing interference histograms with standard format, you must specify the .clc file to be imported. Atoll looks for the associated .dct file in the same directory and uses it to decode transmitter identifiers. If this file is unavailable, Atoll assumes that the transmitter identifiers are the transmitter names. In this case, the columns 1 and 2 of the .clc file must contain the names of the interfered and interferer transmitters instead of their identification numbers.

The .clc file consists of two parts: •

The first part is a header used for format identification. It must start with and contain the following lines:

# Calculation Results Data File. # Version 1.1, Tab separated format. Commented lines start with #. •

The second part details interference histogram of each interfered subcell-interferer subcell pair.

The lines after the header are considered as comments if they start with the symbol "#". If not, they must have the following format:

The 5 tab-separated columns are defined in the table below:

64

AT283_TRG_E2

© Forsk 2010

Chapter 3: File Formats

Column name

Description

Column1

Interfered transmitter

Identification number of the interfered transmitter. If the column is empty, its value is identical to the one of the line above.

Column2

Interfering transmitter

Identification number of the interferer transmitter. If the column is null, its value is identical to the one of the line above.

Column3

Interfered TRX type

Interfered subcell. If the column is null, its value is identical to the one of the line above. In order to save storage, all subcells with no power offset are not duplicated (e.g. BCCH, TCH).

Column4

C/I threshold

C/I value. This column cannot be null.

Column5

Probability C/I > Threshold

Probability to have C/I the value specified in column 4 (C/I threshold). This field must not be empty.

Note: •

3.20.2.1.2

The columns 1, 2, and 3 must be defined only in the first line of each histogram.

Sample # Calculation Results Data File. # Version 1.1, # Remark:

Tab separated format. Commented lines start with #.

C/I results do not incorporate power offset values.

# Fields are: ##------------#------------#------------#-----------#------------------# #| Interfered | Interfering| Interfered | C/I #| Transmitter| Transmitter| Trx type

| Probability

|

| Threshold | C/I >= Threshold |

##------------#------------#------------#-----------#------------------# # # Warning, The parameter settings of this header can be wrong if # the "export" is performed following an "import". They # are correct when the "export" follows a "calculate". # # Service Zone Type is "Best signal level of the highest priority HCS layer". # Margin is 5. # Cell edge coverage probability 75%. # Traffic spreading was Uniform ##---------------------------------------------------------------------# 1

2

TCH_INNER

8 9

1

2

BCCH,TCH

1 0.944

10

0.904

11

0.892

14

0.844

15

0.832

16

0.812

17

0.752

22

0.316

25

0.292

8

1

9

0.944

10

.904

13

0.872

14

0.84

17

0.772

Note:

© Forsk 2010

AT283_TRG_E2

65

Technical Reference Guide •

If the TCH and BCCH histograms are the same, they are not duplicated. A single record indicates that the histograms belong to TCH and BCCH both. For example, instead of:

1 2 TCH 1 2 BCCH

-9.5

1

-9.5

- 9

1

- 6

1

1

- 9

1

- 6

-9.5

1

- 9

1

1

We have:

1 2 TCH,BCCH

3.20.2.2

DCT File

3.20.2.2.1

Description

- 6

1

The .dct file is divided into two parts: •

The first part is a header used for format identification. It must start with and contain the following lines:

# Calculation Results Dictionary File. # Version 1.1, Tab separated format. Commented lines start with #. •

The second part provides information about transmitters taken into account in AFP.

The lines after the header are considered as comments if they start with the symbol "#". If not, they must have the following format:

Column name

Type

Description

Column1

Transmitter name

Text

Name of the transmitter

Column2

Transmitter Identifier

Integer

Identification number of the transmitter

Column3

BCCH during calculation

Integer

BCCH used in calculations

Column4

BSIC during calculation

Integer

BSIC used in calculations

Column5

% of vic’ coverage

Float

Percentage of overlap of the victim service area

Column6

% of int’ coverage

Float

Percentage of overlap of the interferer service area

The last four columns describe the interference matrix scope. One transmitter per line is described separated with a tab character.

3.20.2.2.2

Sample # Calculation Results Dictionary File. # Version 2.1,

Tab separated format. Commented lines start with #.

# Fields are: ##-----------#-----------#-----------#-----------#---------#---------# #|Transmitter|Transmitter|BCCH during|BSIC during|% of vic'|% of int'| #|Name

|Identifier |calculation|calculation|coverage |coverage |

##-----------#-----------#-----------#-----------#---------#---------# # # Warning, The parameter settings of this header can be wrong if # the "export" is performed following an "import". They # are correct when the "export" follows a "calculate". # # Service Zone Type is "Best signal level per HCS layer". # Margin is 5. # Cell edge coverage probability is 75%. # Traffic spreading was Uniform (percentage of interfered area) ##---------------------------#

66

Site0_0

1

-1

-1

100

100

Site0_1

2

-1

-1

100

100

Site0_2

3

-1

-1

100

100

Site1_0

4

-1

-1

100

100

AT283_TRG_E2

© Forsk 2010

Chapter 3: File Formats

3.20.3

Site1_1

5

-1

-1

100

100

Site1_2

6

-1

-1

100

100

Site2_0

7

-1

-1

100

100

Site2_1

8

-1

-1

100

100

One Value per Line (Transmitter Name Repeated) (.im1) Format This file contains one C/I threshold and probability pair value per line for each interfered/interfering subcell pair. The histogram is a list of C/I values with associated probabilities. The .im1 file consists of two parts: •

The first part is a header used for format identification. It must start with and contain the following lines:

# Calculation Results Data File. # Version 1.1, Tab separated format. Commented lines start with #. •

The second part details interference histogram of each interfered subcell-interferer subcell pair.

The lines after the header are considered as comments if they start with the symbol "#". If not, they must have the following format:

The 5 tab-separated columns are defined in the table below:

Column name

Description

Column1

Interfered transmitter

Name of the interfered transmitter.

Column2

Interfering transmitter

Name of the interferer transmitter.

Column3

Interfered TRX type

Interfered subcell. In order to save storage, all subcells with no power offset are not duplicated (e.g. BCCH, TCH).

Column4

C/I threshold

C/I value. This column cannot be null.

Probability C/I > Threshold

Probability to have C/I the value specified in column 4 (C/I threshold). This field must not be empty.

Column5

3.20.3.1

Sample # Calculation Results Data File. # Version 1.1, Tab separated format. Commented lines start with #. # Remark:

C/I results do not incorporate power offset values.

# Fields are: #-----------------------------------------------------------------------#Transmitter

Interferer

TRX type

C/I

Probability

#-----------------------------------------------------------------------# # Warning, The parameter settings of this header can be wrong if # the "export" is performed following an "import". They # are correct when the "export" follows a "calculate". # # Service Zone Type is "Best signal level of the highest priority HCS layer". # Margin is 5. # Cell edge coverage probability 75%. # Traffic spreading was Uniform ##---------------------------------------------------------------------#

© Forsk 2010

Site0_2

Site0_1

BCCH,TCH

-10

Site0_2

Site0_1

BCCH,TCH

-9

0.996

Site0_2

Site0_1

BCCH,TCH

-6

0.976

AT283_TRG_E2

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67

Technical Reference Guide

Site0_2

Site0_1

BCCH,TCH

-4

0.964

Site0_2

Site0_1

BCCH,TCH

-1

0.936

Site0_2

Site0_1

BCCH,TCH

0

0.932

Site0_2

Site0_1

BCCH,TCH

1

0.924

Site0_2

Site0_1

BCCH,TCH

4

0.896

Site0_2

Site0_1

BCCH,TCH

7

0.864

Site0_2

Site0_1

BCCH,TCH

8

0.848

Site0_2

Site0_1

BCCH,TCH

9

0.832

Site0_2

Site0_1

BCCH,TCH

10

0.824

...

3.20.4

Only Co-Channel and Adjacent Values (.im2) Format In this case, there is only one .im2 file containing co-channel and adjacent channel interference probabilities specified for each interfered transmitter – interferer transmitter pair. There is only one set of values for all the subcells of the interfered transmitter. Each line must have the following format:

Where the separator () can either be a tab or a semicolon. The four columns are defined in the table below:

Column name

Description

Column1

Interfered transmitter

Name of the interfered transmitter.

Column2

Interfering transmitter

Name of the interferer transmitter.

Column3

Co-channel interference probability

Column4

Adjacent channel interference probability

Probability of having C  I 

Max BCCH ,TCH

Probability of having C  I 

Max BCCH ,TCH

 C  I req 

 C  I req  – F

C  I req corresponds to the required C/I threshold. This parameter is defined for each subcell. F is the adjacent channel protection level.

3.20.4.1

Sample # Calculation Results Data File. # Version 1.1, Tab separated format. Commented lines start with #. # Remark:

C/I results do not incorporate power offset values.

# Fields are: #-----------------------------------------------------------------------#Transmitter

Interferer

Co-channel

Adjacent channel

#-----------------------------------------------------------------------# # Warning, The parameter settings of this header can be wrong if # the "export" is performed following an "import". They # are correct when the "export" follows a "calculate". # # Service Zone Type is "Best signal level of the highest priority HCS layer". # Margin is 5. # Cell edge coverage probability 75%. # Traffic spreading was Uniform ##---------------------------------------------------------------------#

68

Site0_2

Site0_1

0.226667

0.024

Site0_2

Site0_3

0.27

0.024

AT283_TRG_E2

© Forsk 2010

Chapter 3: File Formats

Site0_3

Site0_1

0.276

0.02

Site0_3

Site0_2

0.226

0.028

The columns in the sample above are separated with a tab. These columns can also be separated with a semilcolon:

Site0_2;Site0_1;0.226667;0.024 Site0_2;Site0_3;0.27;0.024 Site0_3;Site0_1;0.276;0.02 Site0_3;Site0_2;0.226;0.028

3.21

Antenna Pattern Formats This section describes the format of the DIAGRAM field of the Antennas table. This field stores the antenna diagrams in a 2D (angle vs. attenuation) format. This is the format of the contents of the DIAGRAM field of the Antennas table when it is copied from, pasted to, imported to (from txt, csv, or xls files), and exported from (in txt or csv files) the Antennas table. Antenna patterns can also be imported in Planet 2D-format antenna files and 3D antenna files. The file format required for 3D antenna file import is described in "Import Format of Text Files Containing 3D Antenna Patterns" on page 70.

3.21.1

2D Antenna Diagram Format The format of 2D antenna patterns containing co-polar diagrams only can be understood from Figure 3.1 on page 69. Pattern Discriptor 1

Co-polar Horizontal Diagram

Pattern Discriptor 2

Co-polar Vertical Diagram

End

2 0 0 360 0 0 1 0 2 0.1 … 1 0 360 0 0 1 0.1 … 0 Figure 3.12D Antenna Pattern Format Containing Co-polar Diagrams Only The contents of the DIAGRAM field are formatted as follows: •

Pattern Descriptor 1: Space-separated list of parameters. - First entry: The number of co-polar diagrams. For example, 2. - Second entry: First co-polar diagram type = 0 for azimuth (horizontal) diagram. - Third entry: The elevation angle of the azimuth diagram. - Fourth entry: The number of angle-attenuation pairs in the first co-polar diagram. For example, 360.

•

Co-polar Horizontal Diagram: Horizontal co-polar diagram (the second entry in the preceding descriptor is 0). The format is space-separated angle attenuation pairs. For example, 0 0 1 0 2 0.1....

•

Pattern Descriptor 2: Space-separated list of parameters. - First entry: Second co-polar diagram type = 1 for elevation (vertical) diagram. - Second entry: The azimuth angle of the elevation diagram. - Third entry: The number of angle-attenuation pairs in the second co-polar diagram. For example, 360.

•

Co-polar Vertical Diagram: Vertical co-polar diagram (the first entry in the preceding descriptor is 1). The format is space-separated angle attenuation pairs. For example, 0 0 1 0.1....

•

End: The number cross-polar diagrams = 0.

The format of 2D antenna patterns containing co-polar and cross-polar diagrams can be understood from Figure 3.2 on page 69. Pattern Discriptor 1

Co-polar Horizontal Diagram

Pattern Discriptor 3

Pattern Discriptor 2

Cross-polar Horizontal Diagram

Pattern Discriptor 4

Co-polar Vertical Diagram

Cross-polar Vertical Diagram

2 0 0 360 0 0 1 0 2 0.1 … 1 0 360 0 0 1 0.1 … 2 0 0 360 0 0 1 0 2 0.1 … 1 0 360 0 0 1 0.1 … Figure 3.22D Antenna Pattern Format Containing Co-polar and Cross-polar Diagrams The contents of the DIAGRAM field are formatted as follows: •

© Forsk 2010

Pattern Descriptor 1: Space-separated list of parameters. - First entry: The number of co-polar diagrams. For example, 2. - Second entry: First co-polar diagram type = 0 for azimuth (horizontal) diagram. AT283_TRG_E2

69

Technical Reference Guide -

Third entry: The elevation angle of the azimuth diagram. Fourth entry: The number of angle-attenuation pairs in the first co-polar diagram. For example, 360.

•

Co-polar Horizontal Diagram: Horizontal co-polar diagram (the second entry in the preceding descriptor is 0). The format is space-separated angle attenuation pairs. For example, 0 0 1 0 2 0.1....

•

Pattern Descriptor 2: Space-separated list of parameters. - First entry: Second co-polar diagram type = 1 for elevation (vertical) diagram. - Second entry: The azimuth angle of the elevation diagram. - Third entry: The number of angle-attenuation pairs in the second co-polar diagram. For example, 360.

•

Co-polar Vertical Diagram: Vertical co-polar diagram (the first entry in the preceding descriptor is 1). The format is space-separated angle attenuation pairs. For example, 0 0 1 0.1....

•

Pattern Descriptor 3: Space-separated list of parameters. - First entry: The number of cross-polar diagrams. For example, 2. - Second entry: First cross-polar diagram type = 0 for azimuth (horizontal) diagram. - Third entry: The elevation angle of the azimuth diagram. - Fourth entry: The number of angle-attenuation pairs in the first cross-polar diagram. For example, 360.

•

Cross-polar Horizontal Diagram: Horizontal cross-polar diagram (the second entry in the preceding descriptor is 0). The format is space-separated angle attenuation pairs. For example, 0 0 1 0 2 0.1....

•

Pattern Descriptor 4: Space-separated list of parameters. - First entry: Second cross-polar diagram type = 1 for elevation (vertical) diagram. - Second entry: The azimuth angle of the elevation diagram. - Third entry: The number of angle-attenuation pairs in the second cross-polar diagram. For example, 360.

•

Cross-polar Vertical Diagram: Vertical cross-polar diagram (the first entry in the preceding descriptor is 1). The format is space-separated angle attenuation pairs. For example, 0 0 1 0.1....

You may use a 3rd party software or develop a tool to to convert the contents of the DIAGRAM field into binary. In binary, each antenna is described by a header and a list of value pairs. The header is defined as follows: • • • • • • •

flag: (Integer, 32 bits) -1 for omni diagrams, 0 for directional num: (Short integer, 16 bits) Number of diagrams (0, 1, 2, 3, 4) siz0: (Short integer, 16 bits) Size of the first diagram (horizontal co-polar section, elevation = 0°) siz1: (Short integer, 16 bits) Size of the second diagram (vertical co-polar section, azimuth = 0°) siz2: (Short integer, 16 bits) Size of the third diagram (horizontal cross-polar) siz3: (Short integer, 16 bits) Size of the fourth diagram (vertical cross-polar) prec: (Short integer, 16 bits) Precision of the following angle values (100)

Then follows the content of each of the defined diagrams, i.e., the diagrams whose sizes (siz0, siz1, siz2, siz3) are not zero. Each diagram consists of a list of value pairs. The number of value pairs in a list depends on the value of the siz0, siz1, siz2, and siz3 parameters. For example, siz2 = 5 means there are five value pairs in the third diagram. The value pairs in each list are: • •

ang: (Short integer, 16 bits) The first component of the value pair is the angle in degrees multiplied by 100. For example, 577 means 5.77 degrees. loss: (Short integer, 16 bits) The second component of the value pair is the loss in dB for the given angle ang.

All the lists of value pairs are concatenated without a separator.

3.21.2

Import Format of Text Files Containing 3D Antenna Patterns Text files containing 3D antenna patterns that may be imported in Atoll must have the following format: • •

70

Header: The text file may contain a header with additional information. When you import the antenna pattern you can indicate the row number in the file where the header ends and the antenna pattern begins. Antenna Pattern: Each row contains three values to describe the 3D antenna pattern. The columns containing the values can be in any order: - Azimuth: Allowed range of values is from 0° to 360°. The smallest increment allowed is 1°. - Tilt: Allowed range of values is from -90° to 90° or from 0° to 180°. The smallest increment allowed is 1°. - Attenuation: The attenuation in dB.

AT283_TRG_E2

© Forsk 2010

Chapter 4 Calculations

Chapter 4: Calculations

4

Calculations

4.1

Overview Three kinds of predictions are available in Atoll: •

Point analysis enables you to visualise transmitter-receiver profile and to get predictions for a user-defined receiver in real time anywhere on a geographic map (Point analysis window: Profile tab). Coverage studies consider each bin of calculation areas as a potential receiver you can define. Therefore, covered bins correspond to areas where a criterion on the predicted received signal is fulfilled. Point analysis based on path loss matrices enables you to get parameters derived from predicted values in coverage studies (field received, path loss, C/I, UMTS parameters) for a receiver anywhere inside a calculation area (Point analysis window: Reception, Interference, AS analysis tabs).

• •

An overview of different analysis methods is presented in the table below:

Coverage studies

Point analysis

Point analysis based on path loss matrices

Any study

Profile

Reception, Results, Interference, AS analysis

Receiver position

At the centre of each calculation bin within calculation areas

Anywhere. Even beyond computation zone

Anywhere inside the calculation areas

Calculation

Path loss matrix calculation

Real time

No calculation: result coming from path loss matrices

Profile extractiona

Radial except when using SPM

Systematic

Method used for coverage studies: radial except when using SPM

Result

One value inside a calculation bin

Different values inside a calculation bin

One value inside a calculation bin

a.

When using SPM, you can choose either radial or systematic calculation option. Notes: •

In coverage studies, Atoll calculates path loss for every bin within calculation areas. However, only results on calculation bins inside the computation zone are displayed.

•

Profile point analysis is calculated in real time. Therefore, prediction is always consistent with the network. On the other hand, if you modify any parameter (radio or geo), which may make matrices invalid, consider updating the matrices before using point analysis based on path loss matrices.

•

Due to different calculation methods, you can get different results at a same point when performing a point analysis in profile or reception mode.

In any case, prediction is performed in three steps: 1st step: First of all, Atoll calculates the path loss ( L path ), using the selected propagation model. L path = L model + L ant

Tx

+ L ant

Rx

L model is the loss on the transmitter-receiver path calculated through the propagation model. L model value depends on the selected propagation model. L ant

Tx

L ant

Rx

is the transmitter antenna attenuation (from antenna patterns). is the receiver antenna attenuation ( L ant

Rx

= 0 ) (from antenna patterns).

Notes: •

In any project, Atoll considers that the receiver antenna is in the transmitter antenna axis. Therefore, the receiver antenna attenuation is supposed to be zero.

•

Transmitter antenna attenuation may not be considered in this step. It depends on propagation model provider, who may choose to include this parameter in L path calculation. However, all the propagation models available in Atoll calculate L path by considering transmitter antenna attenuation.

2nd step: When the option “Shadowing taken into account” is selected, Atoll evaluates a shadowing margin, M Shadowing – model , from the user-defined model standard deviation at the receiver and the cell edge coverage probability. © Forsk 2010

AT283_TRG_E1

73

Technical Reference Guide Note: •

For a cell edge coverage probability of 50%, the shadowing margin is always zero. In this case, Atoll still works as above.

3rd step: Then, Atoll determines the prediction criterion and displays coverage. For a signal level study, The signal level at the receiver ( P Rec ) is calculated. We have (in dBm): P Rec = EIRP – L path – M Shadowing – model – L Indoor +  G ant Where EIRP = P Tx + G ant

Tx

Rx

– L Rx 

– L Tx

EIRP is the effective isotropic radiated power of the transmitter. P Tx is the transmitter power. G ant

Tx

is the transmitter antenna gain.

L Tx are transmitter losses. M Shadowing – model is the shadowing margin. L Indoor are the indoor losses, taken into account when the option “Indoor coverage” is selected, L Rx are receiver losses. G ant

Rx

is the receiver antenna gain. Notes: •

In UMTS and CDMA documents, P Tx = P Pilot and L Tx = L total – DL .

•

In UMTS and CDMA documents, Atoll considers that G ant

Rx

and L Rx equal zero when

calculating the received signal level (in point analysis, Profile and Reception tabs, and in common coverage studies such as Coverage per transmitter, Coverage by field level, Overlapping). •

In GSM_EGPRS documents, L Tx = L total – DL .

•

In GSM_EGPRS documents, receiver is equipped with an antenna with zero gain.

The prediction is performed for a user-defined cell edge coverage probability (x%). This means that the measured criterion exceeds the predicted criterion for x% of time. The prediction is reliable during x% of time. Note: •

4.2

In case of interference studies, only signal from interfered transmitter (C) is downgraded by the shadowing margin. We consider that interference value (I) is not altered by the shadowing margin.

Path Loss Matrices Atoll is able to calculate two path loss matrices per transmitter, a first matrix over a smaller radius computed with a high resolution and a propagation model (main matrix), and a second matrix over a larger radius computed with a low resolution and another propagation model (extended matrix). To be considered for calculations, a transmitter must fulfil the following conditions: • • •

It must be active, It must satisfy filter criteria defined in the Transmitters folder, and It must have a calculation area.

In the rest of the document, a transmitter fulfilling the conditions detailed above will be called TBC transmitter. The path loss matrix size of a TBC transmitter depends on its calculation area. Atoll determines a path loss value ( L path ) on each calculation bin (calculation bin is defined by the resolution) of the calculation area of the TBC transmitter. You may have one or two path loss matrices per TBC transmitter.

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4.2.1

Calculation Area Determination

4.2.1.1

Computation Zone Transmitter calculation area is made of a rectangle or a square depending on transmitter calculation radius and the computation zone. Calculation radius enables Atoll to define a square around the transmitter. One side of the square equals twice the entered calculation radius. Since the computation zone can be made of one or several polygons, transmitter calculation area corresponds to the intersection area between its calculation square and the rectangle containing the computation zone area(s).

Figure 4.1Example 1: Single Calculation Area

Figure 4.2Example 2: Multiple Calculation Areas Computation zone(s) Rectangle containing the computation zone(s) Calculation area defined (square) Transmitter Calculation area: real area for which Atoll calculates path losses

4.2.2

Calculate / Force Calculation Comparison

4.2.2.1

Calculate The Calculate feature (F7) enables you: 1. To calculate prediction studies The first time you click Calculate (no path loss matrices exist), Atoll computes path loss matrices for each TBC transmitter. Then, it calculates created and unlocked coverage prediction studies inside the computation zone. 2. To check result validity and update calculations If calculations have been performed once and you have changed some parameters such as radio data or calculation area, Atoll automatically detects path loss matrices to be recalculated. These are either one or several path loss matrices that become invalid due to certain modifications. Then Atoll calculates the prediction study, or just the prediction study if matrices were all still valid.

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4.2.2.2

Force Calculation With the Force calculation feature (Ctrl+F7), Atoll deletes all the path loss matrices even if they are valid, recalculates them and then updates the results of prediction studies. Note: •

4.2.3

Geographic data (DTM, clutter) modification makes path loss matrices invalid. However, Atoll does not detect this invalidity just by using Calculate. Therefore, to update calculations, you must click the Force calculation command.

Matrix Validity Atoll manages path loss matrix validity transmitter by transmitter, even in case of transmitters with two path loss matrices (main and extended matrices). Therefore, even if only one path loss matrix of the transmitter is invalid, Atoll will recalculate both of them. All the geographic data modifications and some radio data changes can make matrices invalid. This table lists these modifications and also changes that have an impact only on prediction studies.

Modification

Matrix validity

Impact on

Calculate

Force calculation

Frequency

Invalid

Path loss matrices

Sufficient

Not necessary

Antenna* coordinates (site coordinate: X and Y, Dx and Dy)

Invalid

Path loss matrices

Sufficient

Not necessary

Antennaa height

Invalid

Path loss matrices

Sufficient

Not necessary

a

Invalid

Path loss matrices

Sufficient

Not necessary

a

Invalid

Path loss matrices

Sufficient

Not necessary

a

Antenna pattern Downtilt

Invalid

Path loss matrices

Sufficient

Not necessary

% Power (when there is other antennas)

Invalid

Path loss matrices

Sufficient

Not necessary

Site position/altitude

Invalid

Path loss matrices

Sufficient

Not necessary

Grid resolution (main or/and extended)

Invalid

Path loss matrices

Sufficient

Not necessary

Propagation model (main or/and extended)

Invalid

Path loss matrices

Sufficient

Not necessary

Propagation model parameters

Invalid

Path loss matrices

Sufficient

Not necessary

Calculation areas 1. Calculation areas gets smaller

Valid

Prediction study

Sufficient

Not necessary

Calculation areas 2. Calculation areas gets larger

Invalid

Path loss matrices

Sufficient

Not necessary

Receiver height

Invalid

Path loss matrices

Sufficient

Not necessary

Receiver losses

Valid

Prediction study

Sufficient

Not necessary

Receiver gain

Valid

Prediction study

Sufficient

Not necessary

Prediction study

Sufficient

Not necessary

Azimuth

Receiver antenna

Valid because L ant

Rx

= 0

Geographic layer order

Invalid

Path loss matrices Insufficientb

Necessary

Geographic file resolution

Invalid

Path loss matrices Insufficientb

Necessary

New DTM map

Invalid

Path loss matrices Insufficientb

Necessary

b

Path loss matrices Insufficient

Necessary

New clutter class edition

Invalid

Coverage study resolution

Valid

Prediction study

Cell edge coverage probability

Valid

Prediction study

Sufficient

Not necessary

Coverage study conditions

Valid

Prediction study

Sufficient

Not necessary

Coverage study display options

Valid

Prediction study

Sufficient

Not necessary

Sufficient

Not necessary

a.Modification of any parameter related to main or other antennas makes matrix invalid. b.Except if this action has an impact on the site positions/altitudes.

Tip 1 Calculate or Force Calculation? If you modify radio data or calculation areas, use the Calculate button. On the other hand, if you change geographic data, it is necessary to use Force calculation.

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Tip 2 Calculation area management When performing prediction studies, it is recommended to follow this methodology to minimise recalculations: 1st step: Calculate without computation zone. 2nd step: Draw a computation zone and calculate. 3rd step: Decrease the calculation radius and calculate.

4.3

Path Loss Calculations

4.3.1

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. It is described below. 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 4.3Ground Altitude Determination - 1 1st step: 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 4.4Ground Altitude Determination - 2 2nd step: Atoll determines the S1 and S2 altitudes using a linear interpolation method.

Figure 4.5Ground Altitude Determination - 3 3rd step: Atoll performs a second linear interpolation to evaluate the S altitude.

Figure 4.6Ground Altitude Determination - 4

4.3.2

Clutter Determination Some propagation models need clutter class and clutter height as information at receiver or along a transmitter-receiver profile.

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4.3.2.1

Clutter Class Atoll uses clutter classes file to determine the clutter class.

4.3.2.2

Clutter Height 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 4.7Clutter 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.

4.3.3

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. In fact, it depends on the selected propagation model.

4.3.3.1

Extraction Methods

4.3.3.1.1

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 4.8Radial calculation method

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Chapter 4: Calculations Transmitter Radial: Atoll will extract a geographic profile for each radial Centre of a bin located on the calculation border Receiver: it may be anywhere in point analysis or at the centre of each calculation bin in coverage studies

Figure 4.9Site-bin centre profile The receiver may be located either anywhere within a calculation bin (Point prediction) or at the centre of a calculation bin (Coverage study). Therefore, according to the receiver position, Atoll chooses the nearest profile and uses it (receiver is considered as located on the profile) to perform prediction study at the receiver.

4.3.3.1.2

Systematic Extraction In this case, Atoll systematically extracts a geographic profile between the site (where transmitter resides) and the receiver.

Figure 4.10Radial calculation method Transmitter Geographic profiles Receiver: it may be anywhere in point analysis or at the centre of each calculation bin in coverage studies

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4.3.3.2

Profile Resolution: Multi-Resolution Management Geographic profile resolution depends on resolution of geographic data used by the propagation model (DTM and/or clutter). 1. 1st case: If the chosen propagation model considers both DTM and clutter heights along the profile, the profile resolution will be the highest of the two. Example 1: Standard Propagation Model is used to perform predictions. A DTM map with a 40 m resolution and a clutter heights map with a 20 m resolution are available. Both DTM and clutter maps are considered when using the Standard propagation model. Therefore, here, 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 20m, Atoll uses the bilinear interpolation method described in "Ground Altitude Determination" on page 77. Clutter heights are read from the clutter heights map. Atoll takes the clutter height of the nearest point every 20m (see Path loss calculations: Clutter determination). Example 2: Standard Propagation Model is used to perform predictions. 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 .atl document. Both DTM and clutter maps are considered when using the Standard propagation model. Therefore, here, 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 77. Atoll uses the clutter classes map to determine clutter height. Every 20 m, it determines clutter class and takes associated average height. 2. 2nd case: If the chosen propagation model takes into account only DTM map along the profile, profile resolution will be the highest resolution among the DTM files. Example: Cost-Hata is used to perform predictions. Both DTM maps with 40 m and 25 m resolutions and a clutter map with a 20 m resolution are available.

Explorer window

Work space

DTM •DTM 1 (25m) •DTM 2 (40m) Clutter •Clutter (20m)

Only DTM maps are considered along the whole profile when using Cost-Hata model. Therefore, here, the profile resolution will be 25 m. It means that Atoll will extract geographic information, only the ground altitude, every 25 m. DTM 1 is on the top of DTM 2. Thus, Atoll will consider ground elevation read from DTM 1 in the definition area of DTM 1 and DTM 2 elsewhere. To get ground altitude every 25 m, Atoll uses the bilinear interpolation method described in "Ground Altitude Determination" on page 77. Notes:

80

•

The selected profile resolution does not depend on the geographic layer order. In the last example, whatever the DTM file order you choose, profile resolution will always be 25m. On the other hand, the geographic layer order will influence the usage of data to establish the profile.

•

The calculation bin of path loss matrices defined by the grid resolution is independent of geographic file resolution.

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4.4

Coverage Predictions

4.4.1

Use of Polygonal Zones in Coverage Prediction Reports Prediction statistics are evaluated over the focus zone, if existing, then over the computation zone, if existing, or over the whole covered area. The area of the focus and computation zones are calculated by decomposition in triangles. The area of each prediction is calculated by counting its pixels inside the focus (resp. computation) zone. This number multiplied by the area of one of its pixels gives the total area. This area depends on the resolution of the coverage prediction. At the border of the focus (or computation) zone, pixels are considered either inside or outside the zone. A pixel is inside if its centre is inside the focus zone. If a prediction covers the entire focus (resp. computation) zone, its area should be equal to the focus (or computation) zone area, but as these 2 different methods differ, the results may be slightly different. If it happens that the value of the prediction area is higher than the focus zone area, then the calculated percentage value is higher than 100%. In that case, Atoll9955 automatically replaces it by 100%.

4.4.2

Filtering Coverage Prediction Exports Filtering can directly be applied to any type of prediction export (raster or vector) in order to exclude holes and islands. The principle is to set the colour of each pixel by extracting the dominant colour of the bounding box made of pixels around 2

the pixel to be filled using a dispersion factor: exp  – D   X  2   . where D is the distance from the pixel to be filled to each pixel within the bounding box and where X is the value at that pixel. In other words, the pixel will be filled by the most representative value within this bounding box.

Figure 4.11Bounding box for prediction filtering The user-defined filtering percentage Y gives the size of the bounding box: Y  10 pixels in each direction. In other words, the bounding box is increased by one pixel every 10% (since Y is defined as a percentage in the interface)

4.4.3

Smoothing Coverage Prediction Exports Smoothing can be applied to any prediction export in vector format to simplify its contours. The principle is to reduce the number of points defining the contour of the polygon. This is done using a vertex reduction routine reducing successive vertices which are clustered too closely (vertex reduction within tolerance of prior vertex cluster, Douglas-Peucher polyline simplification). Two methods can be set up in order to define the degree of coverage smoothing.

4.4.3.1

Smoothing: Percentage Method 2 Z The user-defined smoothing percentage Z gives the approximation tolerance: -------  R  ------ , where R is the user-defined 2 20 export resolution. The tolerance defines the interval within which the algorithm tries to reduce the number of points as explained hereafter.

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Figure 4.12Smoothing Tolerance Definition Let’s consider the case of 3 successive points, A1, A2, A3. The aim of smoothing is to reduce the number of points according to the tolerance such that A2 will be deleted if within this tolerance (and A1 and A3 will be directly linked) and A2 will be conserved if outside this tolerance.

4.4.3.2

-

If A2 is outside this interval, the exported shape will be (in blue):

-

If A2 is within this interval, the exported shape will be (in blue):

Smoothing: Number of points method The second method consists in defining a maximum number of points to be deleted. This number of points helps the algorithm to determine the optimised tolerance (See "Smoothing: Percentage Method" on page 81) such that, with this obtained tolerance, the number of points to be deleted will be lower than this value. Let’s consider the following initial coverage

Starting from the maximum possible tolerance, one can estimate the number of points to be filtered out (circled in red).

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If this number is greater than the maximum number of points defined in the interface, Atoll reduces the tolerance until reaching the requested maximum number of points or less.

The first the number of points respecting the constraint is obtained, smoothing is applied by deleting these points and linking the remaining closest points.

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Macro cell

Rooftop

Fixed

Cell size

Receiver location

Receiver

Use

-

Profile extraction mode

Mobile

Rooftop

Macro cell

-

-

d > 10 km 1 < d < 1000 km Low frequencies Land and maritime Broadcast mobile, broadcast

-

-

Diffraction calculation method

Profile based on

Free space loss + Corrections

Free space loss Corrected standard loss

Physical phenomena

-

30-3000 MHz

100-400 MHz

Frequency band

ITU 1546

ITU 370-7 (Vienna 93)

Fixed receivers WLL

Fixed

Street

Macro cell

Radial

DTM

Deygout (3 obstacles) Deygout corrected (3 obstacles)

Free space loss Diffraction loss

30-10000 MHz

ITU 526-5

150-3500 MHz

Standard Propagation Model

Mobile and Fixed

1 < d < 20 km GSM, UMTS, CDMA2000, WiMAX, LTE

Fixed receivers WLL, Microwave links, WiMAX

1 < d < 100 km GSM, CDMA2000, LTE

Mobile

Street

Mobile

Street

Macro cell Mini cell

Radial

DTM

Deygout (1 obstacle)

L(d, f, HRx) (per environment) Diffraction loss

150-2000 MHz

COST-Hata Okumura-Hata

Urban and suburban GSM 900, GSM 1800, areas UMTS, CDMA2000, 100 m < d < 8 km LTE Fixed WiMAX

Fixed

Street

Macro cell Mini cell

Macro cell Mini cell

Macro cell Mini cell

Street Rooftop

Radial

DTM

Deygout (1 obstacle)

L(d, f, HTx, HRx) (per environment) Diffraction loss

1900-6000 MHz

Erceg-Greenstein (SUI)

Radial

DTM

Deygout (1 obstacle)

L(d, f, HRx) (per environment) Diffraction loss

300-1500 MHz

ITU 529-3

Radial Systematic

DTM Clutter

Deygout (3 obstacles) Epstein-Peterson (3 obstacles) Deygout corrected (3 obstacles) Millington (1 obstacle)

Fixed

Street Rooftop

-

Radial

DTM Clutter

Deygout (3 obstacles)

Free space loss L(d, HTxeff, HRxeff, Diff loss, clutter) Diffraction loss

30-10000 MHz

WLL

4.5

Propagation model

Technical Reference Guide

Propagation Models Propagation models available in Atoll are listed in the table below along with their main characteristics.

© Forsk 2010

Chapter 4: Calculations Notes: In formulas described above, L model is stated in dB.

• •

Under Physical phenomena, L(...) expressions refer to formulas customisable in Atoll.

•

SUI stands for Stanford University Interim models.

4.5.1

Okumura-Hata and Cost-Hata Propagation Models

4.5.1.1

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:

4.5.1.2

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

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.

Environment

a(hRx)

Rural/Small city

 1.1 log  f  – 0.7 h Rx –  1.56 log  f  – 0.8 

Large city

3.2  log  11.75h Rx   – 4.97

2

Note: •

4.5.1.3

When receiver antenna height equals 1.5m, a(hRx) is close to 0 dB regardless of frequency.

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. •

© Forsk 2010

If the ‘Add diffraction loss’ option is unchecked, Atoll stops calculations.

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Technical Reference Guide 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 Note: •

Like for any Hata-based model, L model is, by default, limited to the computed free space loss value. It is also possible to avoid this option (option in the related scrolling menu of Configuration tab).

4.5.2

ITU 529-3 Propagation Model

4.5.2.1

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 h Tx   log d 

b

4.5.2.2

Corrections to the ITU 529-3 Path Loss Formula

4.5.2.2.1

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. L model1 = Lu – a  h Rx  for large city and urban environments 2

f 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

4.5.2.2.2

Area Size Correction In the formulas above, a  h Rx  is the environment correction and is defined according to the area size

86

Environment

a(Hr)

Rural/Small city

 1.1 log f – 0.7 h Rx –  1.56 log f – 0.8  AT283_TRG_E1

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Chapter 4: Calculations 2

3.2  log  11.75h Rx   – 4.97

Large city

4.5.2.2.3

Distance Correction The distance correction refers to the term b above.

Distance

b

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: 4d 4d 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 

1. The word ‘terrain’ is used in the original definition of the model rather than ‘environment’. Hence it is used interchangeably with ‘environment’ in this description. © Forsk 2010

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Technical Reference Guide 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. Note: •

4.5.7.3

You can get the same resulting equation by setting a(hBS) = 2.

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 107. The final path loss is the sum of the path loss determined in 1st step and L Diffraction .

Shadow fading is computed in Atoll independent of the propagation model. For more information on the shadow fading calculation, see "Shadowing Model" on page 115.

4.5.8

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.370-7 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. Notes:

100

•

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.

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Chapter 4: Calculations

4.5.8.1

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.

4.5.8.1.1

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.

4.5.8.1.2

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.

4.5.8.1.3

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.

4.5.8.1.4

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.

•

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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. 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),  D f + D h and 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 h1 +  E D 20 – E D h1   ------------------------------------- D 20  D h1  Log    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 101, 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    ---------------------------------- , Log  20  10  Log  20  10 

and 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  eff2 = arc tan  ------------- , and K  is 1.35 for 100 MHz, 3.31 for 600 MHz, 6.00 for 2000 MHz.  9000

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Chapter 4: Calculations e 180  d C h1t = 30  Log  ------------------------ with  e = ---------------------- , a = 6370 km (radius of the Earth), and k = 4  3 is the   e +  eff2 ak 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. 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.

4.5.8.1.5

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 h2 C Receiver =  3.2 + 6.2  Log  f    Log  ------  10

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Technical Reference Guide •

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 Df  Dh 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 as 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.

4.5.8.1.6

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 

4.5.9

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 802.16d and WiMAX 802.16e documents by default. 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]:

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Chapter 4: Calculations 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

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 > PCCPCH 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 neighbour 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.

© Forsk 2010

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453

Technical Reference Guide 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. There must be an overlapping zone ( S A  S B ) with a given cell edge coverage probability. 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. -

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.

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 8.16N-frequency Neighbour Allocation SA  SB Atoll calculates the percentage of covered area ( ----------------------  100 ), which it compares with the % minimum covered 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.

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Chapter 8: TD-SCDMA Networks

Figure 8.17Overlapping Coverages 4. The importance of neighbours. For information on the importance calculation, see "Importance Calculation" on page 456. 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. Notes: •

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: i.

There is space in the cell B neighbour list: cell A will be added to the list. It will be the last one.

ii. 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.

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8.7.2

•

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.

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 453.

8.7.3

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. As indicated in the table below, the neighbour importance depends on the neighbourhood cause; this value varies between from 0 and 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

IF

Adjacent transmitter

If the Force adjacent cells as neighbours option is selected

IF

Neighbourhood relationship that fulfils coverage conditions

If the % minimum covered area is exceeded

IF

Symmetric neighbourhood relationship

If the Force neighbour symmetry option is selected

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 three factors for calculating the importance: • • •

The co-site factor (C) which is a Boolean The adjacency factor (A) which deals with the percentage of adjacency The overlapping factor (O) meaning 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

Overlapping factor (O)

Min  O 

1%

Max  O 

30%

Adjacency factor (A)

Min  A 

30%

Max  A 

60%

Co-site factor (C)

Min  C 

60%

Max  C 

100%

The IF evaluates importance as follows:

Neighbourhood cause

IF

Resulting IF using the default values from the table above

Co-site

Adjacent

No

No

Min  O  +   O   O 

1% + 29%  O 

No

Yes

Min  A  +   A   Max  O   O  +  100% – Max  O    A  

30% + 30%  30%  O  + 70%  A  

Yes

Yes

Min  C  +   C   Max  O   O  +  100% – Max  O    A  

60% + 40%  30%  O  + 70%  A  

Where   X  = Max  X  – Min  X 

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Chapter 8: TD-SCDMA Networks Notes: •

If there is no overlapping between the range of each factor, the neighbours will be ranked by neighbourhood cause. Using the default values for minimum and maximum importance fields, neighbours will be ranked in the following order: i.

Co-site neighbours

ii. Adjacent neighbours iii. Neighbours based on coverage overlapping

8.8

•

If the ranges of the importance factors overlap, the neighbours may not be ranked according to the neighbourhood cause.

•

The ranking between neighbours from the same category depends on the factors (A) and (O).

•

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.

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. Note: •

If no focus zone exists in the .atl document, Atoll takes into account the computation zone.

8.8.1

Automatic Allocation Description

8.8.1.1

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. Notes: •

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 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

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Technical Reference Guide 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.

8.8.1.2

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. Notes: •

•

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.

8.8.1.3

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: • • • • •

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 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

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8.8.1.3.1

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 460.

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 463. For information on calculating cell priority, see "Cell Priority" on page 460.

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 463. or information on calculating cell priority, see "Cell Priority" on page 460.

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

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: • • © Forsk 2010

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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.

8.8.1.3.2

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 462. Note: •

When cells, transmitters or sites have the same priority, processing is based on an alphanumeric order.

8.8.1.4

Priority Determination

8.8.1.4.1

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. 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: 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.

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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 8.18Neighbourhood 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 •

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 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  =

 cN

2G

 j – Tx 2G 

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.

8.8.1.4.2

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 i Tx i  Tx

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.

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8.8.1.4.3

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 Tx S Tx  S

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.

8.8.2

Scrambling Code Allocation Example

8.8.2.1

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 8.19Scrambling 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.

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8.8.2.1.1

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.

8.8.2.1.2

Without "Use a Maximum of Code"

With "Use a Maximum of Code"

Atoll starts allocating the codes from the start of cluster 0 at each site.

As it is possible to use a maximum of codes, Atoll starts 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.

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.

464

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.

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8.8.2.1.3

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.

8.8.2.1.4

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.

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.

8.8.2.2

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.

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

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Technical Reference Guide 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 8.20Scrambling Code Allocation to All Carriers

8.9

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 TDSCDMA 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.

8.9.1

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.

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8.9.1.1

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. Candidate neighbours are sorted in descending order with respect to distance. Note: •

Transmitter azimuths are taken into account to evaluate the inter-transmitter distance. For further information on inter-transmitter distance calculation, please refer to "Calculation of Inter-Transmitter Distance" on page 469.

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. As indicated in the table below, the neighbour importance depends 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

d 1 – -----------d max

Where d is the distance between the UMTS 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.

8.9.1.2

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. Note: •

The inter-transmitter distance is not effected by the azimuths. Only the geographical intertransmitter distance is considered.

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. © Forsk 2010

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Technical Reference Guide 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. -

-

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.

SA  SB Atoll calculates the percentage of covered area ( ----------------------  100 ) and compares this value to the % minimum SA covered 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 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 two factors for calculating the importance: -

The co-site factor (C) which is a Boolean The overlapping factor (O) meaning 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

Overlapping factor (O)

Min  O 

1%

Max  O 

60%

Co-site factor (C)

Min  C 

60%

Max  C 

100%

The IF evaluates importance as follows:

Co-site neighbourhood reason

IF

Resulting IF using the default values from the table above

No

Min  O  +   O   O 

1% + 59%  O 

Yes

Min  C  +   C   O 

60% + 40%  O 

Where   X  = Max  X  – Min  X 

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If there is no overlapping between the range of each factor, the neighbours will be ranked by neighbourhood cause. Using the default values for minimum and maximum importance fields, neighbours will be ranked in the following order: i.

Co-site neighbours

ii. Neighbours based on coverage overlapping •

If the ranges of the importance factors overlap, the neighbours may not be ranked according to the neighbourhood cause.

•

The ranking between neighbours from the same category depends on the factor (O).

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 cosite 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. Notes: •

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.

8.9.1.3

Appendices

8.9.1.3.1

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.

8.9.1.3.2

Calculation of Inter-Transmitter Distance When allocation algorithm is based on distance, Atoll takes into account the real distance and azimuths of antennas in order to calculate the effective inter-transmitter distance. Dist  CellA CellB  = D   1 + x  cos  – x  cos   Where x = 0.5% so that the maximum variation in D does not to exceed 1%. D is stated in m.

Figure 8.21Inter-Transmitter Distance Computation The formula above implies that two cells facing each other have a smaller effective distance than the real physical distance. It is this effective distance that is taken into account rather than the real distance. This formula is not used when allocation algorithm is based on coverage overlapping. In this case, the actual intertransmitter distance is considered.

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Chapter 9 WiMAX BWA Networks

Chapter 9: WiMAX BWA Networks

9

WiMAX BWA Networks This chapter describes all the calculations performed in Atoll WiMAX BWA documents, i.e, WiMAX 802.16d and WiMAX 802.16e. The titles of sections that present 16d- or 16e-specific algorithms include the name of the technology for you to recognize them easily. 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. The third part also describes Forsk’s conventional and optimum beamformer smart antenna models in detail. 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. Important: •

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 74.

•

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. -

-

•

All the calculation algorithms in this section are described for two types of receivers. -

•

9.1

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).

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.

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

Input This table lists the input to computations, 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

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)

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)

O Fixed O Variable O Variable

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Global parameter

%

Ratio of the DL subframe to the entire frame (TDD only)

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)

Global parameter (WiMAX 802.16d) Permutation zone parameter (WiMAX 802.16e)

None

Number of subchannels per channel in UL subframe

N SC – DL

Permutation zone parameter (WiMAX 802.16e)

None

Number of subchannels per channel in DL subframe

N SCa – Total

Global parameter (WiMAX 802.16d) Frame configuration parameter (WiMAX 802.16e)

None

Total number of subcarriers per channel (FFT size)

N SCa – Preamble

Frame configuration parameter (WiMAX 802.16e)

None

Number of subcarriers used by the preamble

Global parameter (WiMAX 802.16d) Permutation zone parameter (WiMAX 802.16e)

None

Number of used subcarriers per channel

Global parameter (WiMAX 802.16d) Permutation zone parameter (WiMAX 802.16e)

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 or

Calculation result ( N SCa – Pilot = N SCa – Used – N SCa – Data or

PZ N SCa – Pilot

None

N SCa – Pilot = N SCa – Used – N SCa – Data )

Number of pilot subcarriers per channel

N SCa – Guard or

Calculation result ( N SCa – Guard = N SCa – Total – N SCa – Used – N SCa – DC or

None

Number of guard subcarriers per channel

TDD

r DL-Frame N SD – DL

N SD – UL

PZ

N SC – UL or N SC – UL PZ

N SCa – Used or PZ N SCa – Used

N SCa – Data or PZ

N SCa – Data

PZ N SCa – Guard

PZ

PZ

PZ

PZ

PZ

N SCa – Guard = N SCa – Total – N SCa – Used – N SCa – DC )

PZ UL

Permutation zone parameter (WiMAX 802.16e)

None

Uplink permutation zone

PZ DL

Permutation zone parameter (WiMAX 802.16e)

None

Downlink permutation zone

QT PZ

Permutation zone parameter (WiMAX 802.16e)

dB

Quality threshold: Required preamble C/N or C/(I+N) for accessing a zone

Speed Max – PZ

Permutation zone parameter (WiMAX 802.16e)

Km/hr

Speed limit for mobiles trying to access a permutation zone

d Max – PZ

Permutation zone parameter (WiMAX 802.16e)

m

Maximum distance from the transmitter covered by a zone

p PZ

Permutation zone parameter (WiMAX 802.16e)

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

f Sampling

Frequency band parameter

None

Sampling factor

N Channel

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Frequency band parameter

dB

Adjacent Channel Suppression Factor

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

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

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

nf

G L

TX

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

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

SU

Cell parameter

%

Segmentation usage ratio

AU

Cell parameter

%

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

NR DL NR UL

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G SU – MIMO

Cell WiMAX equipment parameter

None

Maximum SU-MIMO gain

G STTD

UL

Cell WiMAX equipment parameter

dB

Uplink STTD/MRC 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

f Act

UL

Service parameter

%

Uplink activity factor for voice services

f Act

DL

Service parameter

%

Downlink activity factor for voice services

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

G SU – MIMO

Terminal WiMAX equipment parameter

None

Maximum SU-MIMO gain

G STTD

DL

Terminal WiMAX equipment parameter

dB

Downlink STTD/MRC gain

G STTD

UL

Clutter parameter

dB

Additional uplink STTD/MRC gain

G STTD

DL

Clutter parameter

dB

Additional downlink STTD/MRC 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

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

TP Average

Max

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Any interfering cell whose signal to thermal noise ratio is less than CNR Min will be discarded.

9.1.2

Co- and Adjacent Channel Overlaps Calculation

Name

Value TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

TX j  jc 

TX i  ic  – TX j  jc 

Min  F End

W CCO

TX i  ic 

TX i  ic 

 F End

First

TX j  jc 

TX i  ic 

 – Max  F Start  F Start 

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 

W CCO --------------------------------------TX i  ic  W Channel

TX i  ic  – TX j  jc  r CCO

TX i  ic  – TX j  jc 

TX j  jc 

TX i  ic 

TX j  jc 

TX i  ic 

TX i  ic 

Min  FEnd  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  r ACO L

TX i  ic  – TX j  jc 

W ACO

First

F Start – FB + W Channel   N Channel – N Channel + 1 

F End

W ACO

TX i  ic 

F Start – FB + W Channel   N Channel – N Channel 

F Start

Unit

TX j  jc 

TX i  ic 

Min  F End  F End

H

TX i  ic 

TX j  jc 

TX i  ic 

+ W Channel  – Max  F Start  F End



TX i  ic  – TX j  jc 

W ACO H --------------------------------------TX i  ic  W Channel

TX i  ic  – TX j  jc  r ACO 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 i  ic  – TX j  jc   TXi  ic  – TXj  jc  TX i  ic  – TX j  jc  10 + r ACO  10  r CCO   r FDD – TDD     TX i  ic 

TX i  ic  – TX j  jc  rO

TX j  jc 

if W Channel  W Channel TX  ic  i

– f ACS – FB  TX  ic  --------------------------- TX  ic  – TX  jc  W i  TXi  ic  – TXj  jc  TXi  ic  – TXj  jc  10 i j Channel + r ACO 10 ---------------------- r CCO  r FDD – TDD TX j  jc    W Channel   TX i  ic 

TX j  jc 

if W Channel  W Channel

9.1.3

Preamble Signal Quality Calculations

9.1.3.1

Preamble Signal Level Calculation

Name TX i  ic  C Preamble

Value TX i  ic 

EIRP Preamble – L Path – M Shadowing – Model – L Indoor + G –L

Mi

Mi

Mi

TX i  ic 

TX i  ic 

© Forsk 2010

Description

dBm

Received preamble signal level

dBm

Preamble EIRP of a cell

Mi

– L Ant – L Body

Without smart antennas: P Preamble + G EIRP Preamble

Unit

TX i

–L

With smart antennas: TX i  ic  P Preamble

+G

TX i

–L

TX i

+ 10 

TX i

TX i Log  E SA 

AT283_TRG_E2

477

Technical Reference Guide TX i

L Path

L Total

L Model + L Ant L Path + L Mi

TX i

+ L Indoor + M Shadowing – Model – G

TX i

+L

Mi

–G

dB

Path loss

dB

Total losses

Unit

Description

dBm

Preamble thermal noise for a cell

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 (WiMAX 802.16e)

None

Preamble subcarrier collision probability

Unit

Description

dB

Preamble C/N for a cell

Unit

Description

Mi

Mi

+ L Ant + L Body

9.1.3.2

Preamble Noise Calculation

Name

Value WiMAX 802.16d: TX i  ic   TX  ic  N SCa – Preamble i  n 0 + 10  Log F Sampling  --------------------------------------TX i  ic    N SCa – Total  

TX i  ic 

n 0 – Preamble

WiMAX 802.16e: TX i  ic   TX  ic  N SCa – Preamble Preamble i -  f Segment n 0 + 10  Log  F Sampling  --------------------------------------TX i  ic    N SCa – Total  

1 WiMAX 802.16d: 1 and WiMAX 802.16e: --3

Preamble

f Segment TX i  ic 

TX i  ic 

n Preamble

9.1.3.3

n 0 – Preamble + nf

Mi

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 

+ f Seg

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

10  Log  r O

fO

Inter – Tech

+ I DL



WiMAX 802.16d: 0 TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

f Seg

WiMAX 802.16e: 10  Log  p Collision WiMAX 802.16d: 1

TX i  ic  – TX j  jc 

p Collision

9.1.3.4



WiMAX 802.16e: 1 if

TX i  ic  N Seg

TX j  jc 

= N Seg

TX i  ic 

and 0 if N Seg

TX j  jc 

 N Seg

Preamble C/N Calculation

Name

Value

TX i  ic 

TX i  ic 

CNR Preamble

9.1.3.5

TX i  ic 

C Preamble – n Preamble

Preamble C/(I+N) Calculation

Name

Value TX  ic  i

TX i  ic  CINR Preamble

TX i  ic  C Preamble

n Preamble  TXj  jc      --------------------------- Preamble  I------------------------  10 Inter – Tech dB –  10  Log  10   + 10  + NR DL   10      All TX  jc        j



Preamble C/(I+N) for a cell

TX i  ic 

TX i  ic 

 I + N  Preamble

478

n Preamble  TXj  jc    --------------------------- Preamble  I------------------------ Inter – Tech 10 10  Log  10   + 10  + NR DL  10      All TX j  jc   



AT283_TRG_E2

dBm

Preamble Total Noise (I+N) for a cell

© Forsk 2010

Chapter 9: WiMAX BWA Networks

9.1.4

Traffic and Pilot Signal Quality Calculations

9.1.4.1

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

9.1.4.2 Name

Value TX i  ic 

EIRP Traffic – L Path – M Shadowing – Model – L Indoor + G –L

Mi

Mi

TX i  ic 

Mi

Description

dBm

Received traffic signal level

dBm

Received pilot signal level

dBm

Traffic EIRP of a cell

dBm

Pilot EIRP of a cell

dBm

Traffic transmission power of a cell

dBm

Pilot transmission power of a cell

Unit

Description

dBm

Thermal noise for a cell

None

Segmenting factor

dBm

Downlink noise for a cell

Mi

Mi

– L Ant – L Body

EIRP Pilot –L

Unit

Mi

– L Path – M Shadowing – Model – L Indoor + G

Mi

Mi

– L Ant – L Body TX i  ic 

P Traffic + G TX i  ic 

P Pilot

+G

TX i

TX i

–L –L

TX i

TX i

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

P Preamble – P Traffic P Preamble – P Pilot

Traffic and Pilot Noise Calculation (DL) Value TX i  ic  N SCa – Used WiMAX 802.16d: n 0 + 10  Log  F Sampling  ------------------------------  N SCa – Total M

TX i  ic 

n 0 – DL

i   PZDL N SCa – Used  TXi  ic  - WiMAX 802.16e: n 0 + 10  Log  F Sampling  ----------------------------TX i  ic   N SCa – Total   With Segmentation (WiMAX 802.16e): M

i   PZ DL N SCa – Used  TXi  ic   -  f Segment n 0 + 10  Log  F Sampling  ----------------------------TX i  ic    N SCa – Total  

WiMAX 802.16d: 1 f Segment

TX i  ic 

n DL

9.1.4.3 Name

3  PSG + 2  SSG WiMAX 802.16e: 1 without segmentation, ---------------------------------------------------- with 15 segmentation TX i  ic 

n 0 – DL + nf

Mi

Traffic and Pilot Interference Calculation (DL) Value TX  jc  j

Unit

Description

dBm

Total interference generated by an interfering cell

TX  jc  j

I Idle   I Non – AAS ------------------  -------------------------10 10 Monte Carlo Simulations: 10  Log  10 + 10  without     TX  jc  j

TX j  jc 

I Total

 I AAS   ----------------10  smart antennas, or 10  Log  10  with smart antennas     TX  jc  j

TX  jc  j

TX  jc  j

I Idle I AAS   I Non – AAS -----------------------------------  -------------------------10 10 10 + 10 + 10 Coverage Predictions: 10  Log  10     

© Forsk 2010

AT283_TRG_E2

479

Technical Reference Guide Monte Carlo Simulations: TX j  jc  EIRP Traffic

– L Path – M Shadowing – Model – L Indoor + G

TX j  jc 

I Traffic

Mi

–L

Mi

Mi

Mi

– L Ant – L Body

Coverage Predictions: TX j  jc  EIRP Traffic Mi Mi

+G

–L

dBm

Traffic interference power of an interfering cell

dBm

Pilot interfering power of an interfering cell

dBm

Traffic EIRP of an interfering cell

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

dBm

Interference power of an interfering cell transmitted using smart antenna

dBm

Traffic EIRP of an interfering cell using smart antenna

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

dB

Interference reduction factor due to segmentation (WiMAX 802.16e)

Unit

Description

dB

Traffic C/N for a cell

– L Path – M Shadowing – Model + M Shadowing – C  I – L Indoor Mi

Mi

– L Ant – L Body Monte Carlo Simulations:

TX j  jc  EIRP Pilot

– L Path – M Shadowing – Model – L Indoor + G

TX j  jc 

Mi

–L

Mi

Mi

Mi

– L Ant – L Body

Coverage Predictions:

I Pilot

TX j  jc 

EIRP Pilot +G

Mi

–L

Mi

– L Path – M Shadowing – Model + M Shadowing – C  I – L Indoor Mi

Mi

– L Ant – L Body

TX j  jc 

TX j  jc 

EIRP Traffic

P Traffic + G

TX j  jc 

TX j  jc 

EIRP Pilot

P Pilot

+G

TX j

TX j

–L –L

TX j

TX j

TX  jc  j

TX j  jc  I Non – AAS

 ITraffic  TX j  jc  TX j  jc  N SCa – Data  ---------------- TXj  jc  10 -+ 10  Log  TL DL    10  ----------------------------  1 – AU TX j  jc    N SCa – Used   TX  jc  j

10

I Pilot -----------------10

 TX j  jc   N SCa – Data      1 – -----------------------------    TX j  jc  N SCa – Used    Monte Carlo Simulations:

TX j  jc  EIRP AAS

– L Path – M Shadowing – Model – L Indoor + G

TX j  jc 

I AAS

–L

Mi

Mi

–L

Mi

– L Ant – L Body

Coverage Predictions: TX j  jc  EIRP AAS Mi Mi

+G

– L Path – M Shadowing – Model + M Shadowing – C  I – L Indoor Mi

Mi

– L Ant – L Body

TX j  jc 

TX j  jc 

EIRP AAS

TX j  jc  I Idle – Pilot

Mi

P Traffic + G TX j  jc  EIRP Idle – Pilot

TX j  jc 

–L

– L Path – L Indoor + G TX j  jc 

EIRP Idle – Pilot

TX j

P Idle – Pilot + G

TX j

TX j

Mi

–L

–L

Mi

–

Mi L Ant

–

Mi L Body

TX j

TX j  jc 

TX j  jc  I Idle

  I Idle – Pilot   TX j  jc  --------------------------TX j  jc    N SCa – Data    10 10  Log  1 – TL DL  10 -   1 – ----------------------------  TX j  jc    N SCa – Used      TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

10  Log  r O

fO

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

10  Log  p Collision

f Seg

9.1.4.4

 

Traffic and Pilot C/N Calculation (DL)

Name

Value TX i  ic 

TX i  ic 

C Traffic – n DL

TX i  ic 

TX i  ic  CNR Traffic

DL

DL

With MIMO (STTD/MRC): CNR Traffic + G STTD + G STTD TX i  ic 

TX i  ic 

With MIMO (AMS) if CNR Preamble  T AMS TX i  ic 

TX i  ic 

TX i  ic 

DL

or DL

CINR Preamble  T AMS : CNR Traffic + G STTD + G STTD

480

AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks TX i  ic 

C Pilot

TX i  ic 

– n DL

TX i  ic 

TX i  ic  CNR Pilot

DL

TX i  ic 

TX i  ic 

With MIMO (AMS) if CNR Preamble  T AMS TX i  ic 

TX i  ic 

TX i  ic 

CINR Preamble  T AMS : CNR Pilot

9.1.4.5

DL

+ G STTD + G STTD

With MIMO (STTD/MRC): CNR Pilot

Pilot C/N for a cell

DL

Unit

Description

dB

Traffic C/(I+N) for a cell

dB

Pilot C/(I+N) for a cell

dBm

Traffic Total Noise (I+N) for a cell

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

DL

+ G STTD + G STTD

Traffic and Pilot C/(I+N) Calculation (DL)

Name

Value  TXj  jc    DL  I----------------  – 10  Log  10  10      All TX j  jc  

TX i  ic  C Traffic TX i  ic 

CINR Traffic



TX  ic   i n DL  ------------------+ 10  10 

TX i  ic 

   Inter – Tech  + NR DL     

DL

DL

With MIMO (STTD/MRC): CINR Traffic + G STTD + G STTD TX i  ic 

TX i  ic 

With MIMO (AMS) if CNR Preamble  T AMS TX i  ic  CINR Preamble



TX i  ic  T AMS

:

TX i  ic  CINR Traffic TX  jc  j

TX i  ic  C Pilot TX i  ic 

CINR Pilot

 I DL    ----------------  10 – 10  Log  10      All TX j  jc  



DL

DL

TX  ic  i

n DL    --------------------   Inter – Tech 10  +10  + NR DL       

TX i  ic 

With MIMO (STTD/MRC): CINR Pilot

DL

DL

+ G STTD + G STTD

TX i  ic 

TX i  ic  CINR Preamble



TX i  ic  T AMS

:

TX i  ic  CINR Pilot

TX  jc  j

TX i  ic  N  DL

9.1.4.6

or

+ G STTD + G STTD

TX i  ic 

With MIMO (AMS) if CNR Preamble  T AMS

I +

dB

or

or

DL

DL

+ G STTD + G STTD

TX  ic  i

n DL  IDL    --------------------  ---------------- 10  10 Inter – Tech 10  Log   10  + 10  + NR DL       All TX j  jc   



Traffic Signal Level Calculation (UL)

Name

Value Mi

EIRP UL – L Path – M Shadowing – Model – L Indoor + G

Mi

C UL

–L

TX i

–

Mi L Ant

–

P Mi EIRP UL

With P

Mi

TX i

Mi L Body Mi

+G

Mi

–L

Mi

Mi

= P Max without power control and P

Mi

Mi

= P Eff after power

control

9.1.4.7 Name

Traffic Noise Calculation (UL) Value N SCa – Used TX i  ic  WiMAX 802.16d: n 0 + 10  Log  F Sampling  ------------------------------  N SCa – Total

TX i  ic 

n 0 – UL

TX i  ic 

n UL

© Forsk 2010

M

i   PZUL N SCa – Used  TXi  ic  - WiMAX 802.16e: n 0 + 10  Log  F Sampling  ----------------------------TX i  ic   N SCa – Total  

TX i  ic 

n 0 – UL + nf

TX i  ic 

AT283_TRG_E2

481

Technical Reference Guide

9.1.4.8

Traffic Interference Calculation (UL)

Name

Value

Unit

Description

dBm

Uplink interference received at a cell

dB

Interference reduction factor due to the co- and adjacent channel overlap

10  Log  TL UL 

dB

Interference reduction factor due to the interfering mobile’s uplink traffic load

 TX i  ic  n UL  Mj    ------------------I UL TX i  ic   ------ 10  Inter – Tech 10  Log  – n UL  10  + 10  + NR UL  10      All Mj    All TX  jc  

dB

Uplink noise at a cell without smart antennas

 TX  ic  i n UL    Mj  ------------------I UL   ------10  Inter – Tech 10  Log   + NR UL  10  + 10    10   All Mj     All TX  jc  

dBm

Total Noise (I+N) for a cell

dB

Uplink noise at a cell with smart antenna

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

Mj

Mj

I UL

TX i  ic  – TX j  jc 

C UL + f O

Mj

+ f TL – UL

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

10  Log  r O

fO



Mj

Mj

f TL – UL



TX i  ic 

NR UL

j

TX i  ic 

 I + N UL

 j

2

I UL    +  n  I ----------------------------------2 n  I

NR UL    TX i  ic 

 I + N  UL

2

I UL    +  n  I



9.1.4.9

Traffic C/N Calculation (UL)

Name

Value TX i  ic 

Mi

C UL – n UL

Mi

Mi CNR UL

UL

UL

With MIMO (STTD/MRC): CNR UL + G STTD + G STTD TX i  ic 

TX i  ic 

With MIMO (AMS) if CNR Preamble  T AMS TX i  ic 

TX i  ic 

Mi

UL

or UL

CINR Preamble  T AMS : CNR UL + G STTD + G STTD

9.1.4.10

Traffic C/(I+N) Calculation (UL)

Name

Value TX i  ic 

Mi

Without smart antennas: CNR UL – NR UL TX i  ic 

Mi

With smart antennas: CNR UL – NR UL Mi CINR UL

With MIMO (STTD/MRC): With MIMO (AMS) if TX i  ic  CINR Preamble



TX i  ic  T AMS

Mi CINR UL

UL

:

UL

+ G STTD + G STTD

TX i  ic  CNR Preamble Mi CINR UL





TX i  ic  T AMS

UL

or UL

+ G STTD + G STTD

9.1.5

Throughput Calculation

9.1.5.1

Calculation of Total Cell Resources

Name TX i  ic 

F Sampling

482

Value TX i  ic 

6

W Channel  10   Floor  f Sampling  ----------------------------------------  8000 8000  

AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks TX i  ic 

–3

F Sampling  10 ------------------------------------------TX i  ic  N SCa – Total

kHz

Inter-subcarrier distance

D Sym – Useful

1 ---------------------TX i  ic  F

ms

Useful symbol duration

D CP

r CP -------F

ms

Cyclic prefix duration

D Sym – Useful + D CP

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

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

F

TX i  ic 

TX i  ic 

TX i  ic 

D Symbol Used

TX i  ic 

TDD

D Frame TX i  ic 

N  SD – Used   Frame

TDD

If DL:UL ratio is defined in percentage: TX i  ic 

TDD

DL

RoundUp  N  SD – Used   Frame  r DL – Frame  – O Fixed TX i  ic 

N  SD – DL   Subframe

If DL:UL ratio is defined in fraction: TDD

N SD – DL  TX i  ic   DL RoundUp  N  SD – Used   Frame  ------------------------------------------------ – O Fixed TDD TDD  N SD – DL + N SD – UL WiMAX 802.16d: DL

TX i  ic  R DL

=

TX i  ic 

N  Sym – DL   Subframe

TX i  ic   O Variable   TXi  ic  Floor  N  SD – DL   Subframe  N SCa – Data   1 – ---------------------- 100     WiMAX 802.16e: M

DL

i PZDL  O Variable   TXi  ic  Floor  N  SD – DL   Subframe  N SCa – Data   1 – ---------------------- 100    

If DL:UL ratio is defined in percentage: TX i  ic 

TDD

UL

RoundDown  N  SD – Used   Frame   1 – r DL – Frame   – O Fixed TX i  ic 

N  SD – UL   Subframe

If DL:UL ratio is defined in fraction: TDD

N SD – UL  TXi  ic   UL RoundDown  N  SD – Used   Frame  ------------------------------------------------ – O Fixed TDD TDD  N SD – DL + N SD – UL WiMAX 802.16d: UL

TX i  ic  R UL TX i  ic 

=

N  Sym – UL   Subframe

© Forsk 2010

TX i  ic   O Variable   TXi  ic  Floor  N  SD – UL   Subframe  N SCa – Data   1 – ---------------------- 100     WiMAX 802.16e: M

UL

i PZUL  O Variable   TXi  ic  Floor  N  SD – UL   Subframe  N SCa – Data   1 – ---------------------- 100    

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9.1.5.2

Channel Throughput, Cell Capacity, and Allocated Bandwidth 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

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

i

DL Without segmentation: -----------------------------------D Frame

TX i  ic 

R DL Mi

 B

Mi

DL -  f Segment With segmentation: -----------------------------------D Frame

CTP P – DL

With MIMO (SU-MIMO): 

M

Max

= 

i

B DL

M

i

B DL

With MIMO (AMS): 

  1 + f SU – MIMO  G SU – MIMO – 1   Max

= 

Mi

B DL

Mi

B DL

TX i  ic 

TX i  ic 

CNR Preamble  T AMS

  1 + f SU – MIMO  G SU – MIMO – 1   if TX i  ic 

TX i  ic 

or CINR Preamble  T AMS

Mi

Mi

Mi

CTP P – DL   1 – BLER  B DL  

Mi

Mi f TP – Scaling Mi CTP E – DL  ----------------------------- – TP Offset 100

Mi

CTP P – DL  TL DL – Max

Mi

Cap P – DL   1 – BLER  B DL  

Mi

f TP – Scaling Mi Mi Cap E – DL  ----------------------------- – TP Offset 100

CTP E – DL

Mi

CTP A – DL

TX i  ic 

Mi

Cap P – DL

Mi

Cap E – DL

Mi

Mi

Cap A – DL

TX i  ic 

R UL



M

B

i

UL Without segmentation: -----------------------------------D Frame

With MIMO (SU-MIMO): 

Mi

Mi

CTP P – UL

Max

= 

B UL

Mi

B UL

With MIMO (AMS): 

  1 + f SU – MIMO  G SU – MIMO – 1   Max

= 

Mi

B UL TX i  ic 

Mi

B UL TX i  ic 

CNR Preamble  T AMS

  1 + f SU – MIMO  G SU – MIMO – 1   if 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



M

B

i

TX  ic 

UL ------------------------------------  G MUi – MIMO D Frame

Mi

Mi

Mi

CTP P – UL   1 – BLER  B UL  

Mi

Mi Mi f TP – Scaling CTP E – UL  ----------------------------- – TP Offset 100

Mi

CTP P – UL  TL UL – Max

Mi

Cap P – UL   1 – BLER  B UL  

CTP E – UL

CTP A – UL Cap P – UL Cap E – UL Mi

Cap A – UL

Mi

TX i  ic 

Mi

Mi

Mi Cap E – UL

Mi

Mi

Mi f TP – Scaling  ----------------------------- – TP Offset 100 Mi

Mi ABTP P – UL

484

N SC – UL Mi CTP P – UL  -------------------M i

PZUL N SC

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Chapter 9: WiMAX BWA Networks Mi

Mi

Mi

ABTP P – UL   1 – BLER  B UL  

Mi

Mi f TP – Scaling Mi ABTP E – UL  ----------------------------- – TP Offset 100

ABTP E – UL

ABTP A – UL

9.1.6

kbps

Uplink effective MAC allocated bandwidth throughput

kbps

Uplink application allocated bandwidth throughput

Mi

Scheduling and Radio Resource Management

Name

Value

Sel

TPD Min – DL -----------------------------Sel

Unit

Description

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

None

Remaining uplink cell resources after allocation for minimum throughput demands

kbps

Remaining throughput demand for a mobile in downlink

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

Sel

Mi

Mi R Min – DL

Mi

CTP P – DL Sel

Mi

TPD Min – UL -----------------------------Sel

Sel

Mi R Min – UL

Mi

CTP P – UL TX i  ic 

R Rem – DL

Sel

TX i  ic 

Mi

 RMin – DL

TL DL – Max –

Sel

Mi

TX i  ic  R Rem – UL

Sel

TX i  ic 

Mi

 RMin – UL

TL DL – Max –

Sel

Mi Sel

Mi

TPD Rem – DL Sel

Mi

TPD Rem – UL

Sel

Sel

Mi

Mi

TPD Max – DL – TPD Min – DL Sel

Sel

Mi

Mi

TPD Max – UL – TPD Min – UL Sel

Sel

Mi RD Rem – DL

Mi

TPD Rem – DL --------------------------------Sel Mi CTP P – DL Sel

Sel

Mi RD Rem – UL

Mi

TPD Rem – UL --------------------------------Sel Mi CTP P – UL

TX i  ic 

Sel R Rem – DL Mi  Proportional Fair: Min  RD Rem – DL ------------------------- N   Sel

Proportional Demand: Sel Mi

R Max – DL

TX i  ic  R Eff – Rem – DL

Mi

RD Rem – DL  --------------------------------------Sel Mi

 RDRem – DL Sel

Mi

TX i  ic 

Sel R QoS – DL Mi  Biased (QoS Class): Min  RD Rem – DL ------------------------ N QoS   Sel

Mi

TPD Rem – DL Max Aggregate Throughput: --------------------------------Sel Mi

CTP P – DL

© Forsk 2010

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Technical Reference Guide TX i  ic 

Sel R Rem – UL Mi  Proportional Fair: Min  RD Rem – UL ------------------------- N   Sel

Proportional Demand:

TX i  ic  R Eff – Rem – UL

Mi

RD Rem – UL  --------------------------------------Sel Mi

 RDRem – UL

Sel Mi

Sel

Mi

R Max – UL

None

Resources allocated to a mobile to satisfy its maximum throughput demand in uplink

None

Effective remaining downlink resources in a cell (Proportional Demand)

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))

None

Remaining downlink cell resources after allocation for minimum throughput demands for a QoS class (Biased (QoS Class))

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

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  ic  i Min  R Rem – DL  

TX i  ic  R Eff – Rem – DL

 TX  ic  i Min  R Rem – UL  

TX i  ic 

R Eff – Rem – UL

Sel  Mi RD Rem – DL   Sel

 Mi

Mi



Sel

Mi

Sel

QoS



Sel

 RDRem – UL Sel

Mi

Sel

Mi

Mi

f Bias R Max – rtPS R Max – nrtPS R Max – ErtPS 1 + ---------- = -----------------------------= ------------------------------ = -----------------------------Sel Sel Sel 100 Mi Mi Mi R Max – rtPS R Max – nrtPS R Max – BE



r

1 QoS N QoS   ---   TX i  ic  R Rem – DL  -----------------------------------------------------------r 1 QoS N QoS   ---  

TX i  ic  R QoS – DL



All QoS r

TX i  ic  R Rem – UL

TX i  ic  R QoS – UL

1 QoS N QoS   ---    -----------------------------------------------------------r 1 QoS N QoS   ---  



All QoS Sel

Mi

TL DL

Sel

Mi

= R DL

Sel

Mi TL UL

Sel

Mi R UL

=

9.1.6.1

Sel

Sel

Mi

Mi

R Min – DL + R Max – DL Sel

Mi R Min – UL

Sel

+

Mi R Max – UL

User Throughput Calculation

Name

Value

Sel

Mi

UTP P – DL Sel

Mi

UTP E – DL

Sel

Sel

Mi

Mi

R DL  CTP P – DL Sel

Sel

Mi Mi UTP P – DL   1 – BLER  B DL      Sel

Sel

Mi

UTP A – DL

Sel

Mi UTP E – DL

Sel

Mi

UTP P – UL Sel

Mi

UTP E – UL

Mi

Sel f TP – Scaling Mi  ----------------------------- – TP Offset 100 Sel

Sel

Mi

Mi

R UL  CTP P – UL Sel

Sel

Mi Mi UTP P – UL   1 – BLER  B UL      Sel

Sel

Mi UTP A – UL

486

Sel

Mi UTP E – UL

Mi

Sel f TP – Scaling Mi  ----------------------------- – TP Offset 100

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Chapter 9: WiMAX BWA Networks

9.1.7

Smart Antenna Models

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

9.1.7.1

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 

None

Average array correlation matrix

S

1 e

2 j  -------  d  sin  

e

2 j  -------  2d  sin  

e

wn e

 ... e

T 2 j  -------   E SA – 1 d  sin  

2 – j  -------  nd  sin  

 with d = --2

– j    n  sin 

H

R

S  S

G SA   

g n     S   R   S  = g n     S   S   S   S  = g n     E SA

H

H

H

2

J

 j  pj  Rj

R Avg

j=1

9.1.7.2

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

 pj  Sj  Sj

2

Rn + RI = n  I +

H

j=1 2 n

Rn

I

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   E SA P ------- = ---------------------------H PN w  RN  w

None

C/(I+N) in the uplink

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

H

K

RN

1 ----  K

Avg

 RN k k=1

I UL   

© Forsk 2010

H

w  RN

2

Avg

 w – n

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I UL    +  n ----------------------------2 n

NR UL   

9.1.7.3

None

Angular distribution of uplink noise rise

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

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)

None

C/(I+N) in the uplink

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

–1

J

RN

2 n

Rn + RI =

I+

 pj  Sj  Sj

H

j=1 2

n  I

Rn J

 pj  Sj  Sj

RI

H

j=1

Pˆ N

H

2 

–1

 S  RN  S 2

Pˆ 

p     S  RN  S 

CINR UL

P H Pˆ –1 ------- = ------- = p   S   R N  S  ˆ PN PN

G SA

S   I  S  = E SA

H

2

–1

H

K

1 ----  K

–1

RN

Avg

 RN

–1 k

k=1

E SA 2 ------------------------------------------ – n H –1 S  RN  S

I UL   

Avg

2

I UL    +  n ----------------------------2 n

NR UL   

9.2

Calculation Processes The following sections describe the processes of different calculations performed in Atoll and their results.

9.2.1

Point Analysis: Profile Tab The point analysis profile tab displays the following calculation results for the selected transmitter based on the calculation algorithm described in "Preamble Signal Level Calculation" on page 512.

L

9.2.2

Mi

TX i  ic 

•

Preamble signal level C Preamble

•

Path loss L Path

•

Total losses L Total

, G

Mi

Mi

Mi

, L Ant , and L Body are not used in the calculations performed for the profile tab.

Point Analysis: Reception Tab Analysis provided in the Reception tab 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.

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Chapter 9: WiMAX BWA Networks 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. The Reception tab calculates: • • • • • • • • • • • • •

9.2.3

The preamble signal level as explained in "Preamble Signal Level Calculation" on page 512. The preamble C/N as explained in "Preamble C/N Calculation" on page 516. The preamble C/(I+N) and total noise (I+N) as explained in "Preamble C/(I+N) Calculation" on page 517. The best server as explained in "Best Server Determination" on page 517. The service availability as explained in "Service Area Calculation" on page 518. The permutation zone as explained in "Permutation Zone Selection (WiMAX 802.16e)" on page 519. The downlink traffic and pilot signal levels as explained in "Traffic and Pilot Signal Level Calculation (DL)" on page 520. The downlink traffic and pilot C/N as explained in "Traffic and Pilot C/N Calculation (DL)" on page 530. The downlink traffic and pilot C/(I+N) and the traffic total noise (I+N) as explained in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532. The uplink signal level as explained in "Traffic Signal Level Calculation (UL)" on page 534. The uplink C/(I+N) and total noise (I+N) as explained in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541. The downlink and uplink bearers as explained in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532 and "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541. The different throughputs as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

Point Analysis: Interference Tab Analysis provided in the Interference tab 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. Ten interferer bar graphs are displayed by default. This number can be changed through the Atoll.ini file. For more information on defining a different number of interferers, see the Administrator Manual. The Interference tab calculates: • • • • • • • • • •

9.2.4

The preamble signal level as explained in "Preamble Signal Level Calculation" on page 512. The preamble C/(I+N) and total noise (I+N) as explained in "Preamble C/(I+N) Calculation" on page 517. The best server as explained in "Best Server Determination" on page 517. The service availability as explained in "Service Area Calculation" on page 518. The permutation zone as explained in "Permutation Zone Selection (WiMAX 802.16e)" on page 519. The downlink traffic and pilot signal levels as explained in "Traffic and Pilot Signal Level Calculation (DL)" on page 520. The downlink traffic and pilot C/(I+N) and the traffic total noise (I+N) as explained in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532. The channel overlap as explained in "Co- and Adjacent Channel Overlaps Calculation" on page 477. The collision probability due to segmentation as explained in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532. The interference reduction due to the downlink traffic load as explained in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532.

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

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. TX i  ic 

For these calculations, Atoll calculates the received preamble signal level ( C Preamble ) as explained in "Preamble Signal Level Calculation" on page 512. Then, Atoll determines the selected display criterion 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 preamble signal level based coverage

predictions. Coverage prediction parameters to be set are: • •

© Forsk 2010

The coverage prediction conditions to determine the coverage area of each studied cell, and The display settings to colour the coverage areas.

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489

Technical Reference Guide The following sections describe the determination of coverage area of each cell ("Coverage Area Determination" on page 490), and the display options ("Coverage Display" on page 490) of the coverage predictions.

9.2.4.1

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.

9.2.4.1.1

All Servers The coverage area of each cell TXi(ic) corresponds to the pixels where. TX i  ic 

TX i  ic 

MinimumThreshold  C Preamble  or L Total

9.2.4.1.2

TX i  ic 

or L Path

  MaximumThreshold

Best Signal Level and a Margin The coverage area of each cell TXi(ic) corresponds to the pixels where. TX i  ic 

TX i  ic 

MinimumThreshold  C Preamble  or L Total

TX i  ic 

or L Path

  MaximumThreshold

AND TX i  ic  TX j  jc  C Preamble  Best  C Preamble  – M ji

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.

9.2.4.1.3

Second Best Signal Level and a Margin The coverage area of each cell TXi(ic) corresponds to the pixels where. TX i  ic 

TX i  ic 

MinimumThreshold  C Preamble  or L Total

TX i  ic 

or L Path

  MaximumThreshold

AND TX  ic 

i C Preamble  2

nd

TX  jc 

Best  C j Preamble  – M ji

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.

9.2.4.2

Coverage Display

9.2.4.2.1

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 Calculations" on page 77 for more information).

9.2.4.2.2

Display Types 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) Atoll calculates preamble signal levels received from cells on each pixel of the cells’ coverage areas. A pixel of a coverage area is coloured if the preamble signal level exceeds (  ) the defined minimum thresholds (pixel colour depends on received preamble signal level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as cell coverage areas. Each layer shows the different preamble signal levels received in the cell coverage area.

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Best Signal Level (dBm, dBµV, dBµV/m) Atoll calculates preamble signal levels received from cells on each pixel of the cells’ coverage areas. Where other coverage areas overlap the studied one, Atoll chooses the highest value. A pixel of a coverage area is coloured if the preamble signal level exceeds (  ) the defined thresholds (the pixel colour depends on the preamble 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 preamble signal level from the best server exceeds a defined threshold.

Path Loss (dB) Atoll calculates path losses from cells on each pixel of the cells’ coverage areas. A pixel of a coverage area is coloured if the path loss exceeds (  ) 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 cell coverage areas. Each layer shows different path loss levels in the cells’ coverage area.

Total Losses (dB) Atoll calculates total losses from cells on each pixel of the cells’ coverage areas. A pixel of a coverage area is coloured if total losses exceed (  ) 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 cell coverage areas. Each layer shows different total losses levels in the cells’ coverage areas.

Best Server Path Loss (dB) Atoll calculates preamble signal levels received from cells on each pixel of the cells’ coverage areas. Where other coverage areas overlap the studied one, Atoll determines the best cell (i.e., the cell with the highest preamble signal level) and evaluates the path loss from this cell. A pixel of a coverage area is coloured if the path loss exceeds (  ) 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 threshold.

Best Server Total Losses (dB) Atoll calculates preamble signal levels received from cells on each pixel of the cells’ coverage areas. Where coverage areas overlap the studied one, Atoll determines the best cell (i.e., the cell with the highest preamble signal level) and evaluates total losses from this cell. A pixel of a coverage area is coloured if the total losses exceed (  ) 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 threshold.

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). 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 exceeds (  ) a defined threshold.

9.2.5

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 and noise at each pixel for the signal 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. Coverage prediction parameters to be set are: • •

The coverage prediction conditions, and The display settings to colour the coverage areas.

The following sections describe the determination of coverage area of each cell ("Coverage Area Determination" on page 492), the calculation of the coverage parameter ("Coverage Parameter Calculation" on page 492), and the display options ("Coverage Display" on page 492) of the coverage predictions.

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9.2.5.1

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 517.

9.2.5.2

Coverage Parameter Calculation The following parameters are calculated for the Effective Signal Analysis (DL) coverage prediction. •

TX i  ic 

Best Preamble Signal Level (DL) (dBm): C Preamble as explained in "Preamble Signal Level Calculation" on page 512.

•

TX i  ic 

Best Pilot Signal Level (DL) (dBm): C Pilot

as explained in "Traffic and Pilot Signal Level Calculation (DL)" on

page 520. •

TX i  ic 

Best Traffic Signal Level (DL) (dBm): C Traffic as explained in "Traffic and Pilot Signal Level Calculation (DL)" on page 520. TX i  ic 

•

Preamble C/N Level (DL) (dB): CNR Preamble as explained in "Preamble C/N Calculation" on page 516.

•

Pilot C/N Level (DL) (dB): CNR Pilot

• •

TX i  ic 

Traffic C/N Level (DL) (dB): Permutation Zone (DL):

as explained in "Traffic and Pilot C/N Calculation (DL)" on page 530.

TX i  ic  CNR Traffic

Mi PZ DL

as explained in "Traffic and Pilot C/N Calculation (DL)" on page 530.

as explained in "Permutation Zone Selection (WiMAX 802.16e)" on page 519.

The following parameters are calculated for the Effective Signal Analysis (UL) coverage prediction. Mi

•

Signal Level (UL) (dBm): C UL as explained in "Traffic Signal Level Calculation (UL)" on page 534.

•

C/N Level (UL) (dB): CNR UL as explained in "Traffic C/N Calculation (UL)" on page 537.

•

Permutation Zone (UL): PZ UL as explained in "Permutation Zone Selection (WiMAX 802.16e)" on page 519.

Mi

9.2.5.3

Coverage Display

9.2.5.3.1

Coverage Resolution

Mi

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 Calculations" on page 77 for more information).

9.2.5.3.2

Effective Signal Analysis (DL) Display Types It is possible to display the Effective Signal Analysis (DL) coverage prediction with colours depending on the following display options.

Best Preamble Signal Level (DL) (dBm) Atoll calculates preamble signal levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the preamble signal level exceeds (  ) the defined thresholds (the pixel colour depends on the preamble 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 preamble signal level from the best server exceeds a defined threshold.

Best Pilot Signal Level (DL) (dBm) Atoll calculates pilot signal levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the pilot signal level exceeds (  ) the defined thresholds (the pixel colour depends on the pilot 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 pilot signal level from the best server exceeds a defined threshold.

Best Traffic Signal Level (DL) (dBm) Atoll calculates traffic signal levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the traffic signal level exceeds (  ) the defined thresholds (the pixel colour depends on the traffic 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 traffic signal level from the best server exceeds a defined threshold.

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Preamble C/N Level (DL) (dB) Atoll calculates preamble C/N levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the preamble C/N level exceeds (  ) the defined thresholds (the pixel colour depends on the preamble C/N 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 preamble C/N level from the best server exceeds a defined threshold.

Pilot C/N Level (DL) (dB) Atoll calculates pilot C/N levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the pilot C/N level exceeds (  ) the defined thresholds (the pixel colour depends on the pilot C/N 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 pilot C/N level from the best server exceeds a defined threshold.

Traffic C/N Level (DL) (dB) Atoll calculates traffic C/N levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the traffic C/N level exceeds (  ) the defined thresholds (the pixel colour depends on the traffic C/N 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 traffic C/N level from the best server exceeds a defined threshold.

Permutation Zone (DL) Atoll calculates the permutation zone assigned to each pixel of each best server’s coverage area. A pixel of a coverage area is coloured according to the permutation zone assigned to it (the pixel colour depends on the frame configuration permutation zone pair). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as frame configuration - permutation zone pairs. Each layer corresponds to an area where a frame configuration - permutation zone pair is used.

Segment Atoll calculates the permutation zone assigned to each pixel of each best server’s coverage area. Pixels are coloured according to the segment number (calculated from the best server’s preamble index) when the assigned permutation zone is the first downlink PUSC zone and the best server’s frame configuration supports segmentation. For all other cases, i.e., other permutation zones or segmentation not supported in the best server’s frame configuration, pixels are assigned a unique colour. Coverage consists of four independent layers whose visibility in the workspace can be managed. Three of these layers correspond to a segment number each, and one corresponds to the case where segmentation is not supported, i.e., all segments are used.

9.2.5.3.3

Effective Signal Analysis (UL) Display Types It is possible to display the Effective Signal Analysis (UL) coverage prediction with colours depending on the following display options.

Signal Level (UL) (dBm) Atoll calculates uplink signal levels received from each pixel, of the coverage areas of the best serving cells, at the cells. A pixel of a coverage area is coloured if the uplink signal level exceeds (  ) the defined thresholds (the pixel colour depends on the uplink 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 uplink signal level at the best server exceeds a defined threshold.

C/N Level (UL) (dB) Atoll calculates uplink C/N levels received from each pixel, of the coverage areas of the best serving cells, at the cells. A pixel of a coverage area is coloured if the uplink C/N level exceeds (  ) the defined thresholds (the pixel colour depends on the uplink C/N 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 uplink C/N level at the best server exceeds a defined threshold.

Permutation Zone (UL) Atoll calculates the permutation zone assigned to each pixel of each best server’s coverage area. A pixel of a coverage area is coloured according to the permutation zone assigned to it (the pixel colour depends on the frame configuration permutation zone pair). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as frame configuration - permutation zone pairs. Each layer corresponds to an area where a frame configuration - permutation zone pair is used.

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9.2.6

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 517.

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 following parameters for each subscriber in the list that has a serving base station assigned, using the properties of the default terminal and service. • • • • • • • • • •

Received Preamble Power (DL) (dBm) as described in "Preamble Signal Level Calculation" on page 512. Received Traffic Power (DL) (dBm) as described in "Traffic and Pilot Signal Level Calculation (DL)" on page 520. Received Pilot Power (DL) (dBm) as described in "Traffic and Pilot Signal Level Calculation (DL)" on page 520. Preamble Total Noise (I+N) (DL) (dBm) as described in "Preamble C/(I+N) Calculation" on page 517. Traffic Total Noise (I+N) (DL) (dBm) as described in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532. Preamble C/(I+N) (DL) (dB) as described in "Preamble C/(I+N) Calculation" on page 517. Traffic C/(I+N) (DL) (dB) as described in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532. Pilot C/(I+N) (DL) (dB) as described in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532. Bearer (DL) as described in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532. Permutation Zone (DL) as described in "Permutation Zone Selection (WiMAX 802.16e)" on page 519.

•

BLER (DL): Downlink block error rate read from the BLER vs. CINR Traffic graph available in the WiMAX

• • • • •

equipment assigned to the terminal used by the subscriber. Diversity Mode (DL): Antenna diversity mode supported by the cell or permutation zone assigned to the subscriber in downlink. Peak MAC Channel Throughput (DL) (kbps) as described in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547. Effective MAC Channel Throughput (DL) (kbps) as described in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547. Received Power (UL) (dBm) as described in "Traffic Signal Level Calculation (UL)" on page 534. Total Noise (I+N) (UL) (dBm) as described in "Noise Rise Calculation (UL)" on page 537. C/(I+N) (UL) (dB) as described in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541. Bearer (UL) as described in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541. Permutation Zone (UL) as described in "Permutation Zone Selection (WiMAX 802.16e)" on page 519.

•

BLER (UL): Uplink block error rate read from the BLER vs. CINR UL graph available in the WiMAX equipment

• • •

• • • • •

9.2.7

TX i  ic 

Mi

assigned to the serving cell of the subscriber. Diversity Mode (UL): Antenna diversity mode supported by the cell or permutation zone assigned to the subscriber in uplink. Transmission Power (UL) as described in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541. Allocated Bandwidth (UL) (No. of Subchannels) as described in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541. Peak MAC Channel Throughput (DL) (kbps) as described in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547. Effective MAC Channel Throughput (DL) (kbps) as described in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

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 494. 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.

•

9.2.7.1

Scheduling and Radio Resource Management as explained under "Simulation Process" on page 498.

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. • •

494

"Simulations Based on User Profile Traffic Maps and Subscriber Lists" on page 495. "Simulations Based on Sector Traffic Maps" on page 496.

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Atoll follows a Poisson distribution to determine the total number of users attempting a connection in each simulation. In order for Atoll to use a constant total number of users attempting a connection, the following lines must be added to the Atoll.ini file:

[CDMA] RandomTotalUsers=0

9.2.7.1.1

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 Notes: •

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

•

The number of users is a direct input when a user profile traffic map is composed of points.

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 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

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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

DL TP Average

DL

and the uplink

and the uplink V

UL TP Average

UL

during a session.

for the service d.

UL

Calculation of activity probabilities: f

UL

DL

N Session  V  8 N Session  V  8 DL = -----------------------------------------------= -----------------------------------------------and f UL DL TP Average  3600 TP Average  3600

Probability of being inactive: p Inactive =  1 – f

UL

UL

  1 – f

Probability of being active in the uplink: p Active = f DL

UL

Probability of being active in the downlink: p Active = f

DL



 1 – f DL

DL



 1 – f

UL



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 Inactive users are not taken into account. Note: •

9.2.7.1.2

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.

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: UL

N

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 DL

the transmitter, TP Cell is the total downlink throughput demand defined in the map for any service s for the

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coverage area of the transmitter, TP Average is the average uplink requested throughput of the service s, and DL

TP Average is the average downlink requested throughput of the service s. •

Sector Traffic Maps (# Active Users) UL

DL

Atoll directly uses the defined N and N transmitter coverage area using the service s.

values, i.e., the number of active users on UL and DL in the

At any given instant, Atoll calculates the probability for a user being active in the uplink and in the downlink as follows:

Voice Service (v) Users active in the uplink and downlink both are included in the N to accurately determine the number of active users in the uplink

UL

and N

UL ( n v – Active

DL

values. Therefore, it is necessary DL

), in the downlink ( n v – Active ), and both

UL + DL

( n v – Active ). As for the other types of traffic maps, Atoll considers both active and inactive users for voice services. 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 the number of active users trying to access the voice service v: We have: N

UL

UL

UL + DL

=  p Active + p Active   n v and N

DL

DL

UL + DL

=  p Active + p Active   n v

Where, nv is the total number of active users in the transmitter coverage area using the service v. Calculation of number of users per activity status: UL

UL + DL

DL

UL + DL

N  p Active   N  p Active UL + DL - ------------------------------------------- or Number of users active in the uplink and downlink both: n v – Active = Min  ------------------------------------------UL + DL DL UL + DL  p UL  p + p Active Active Active + p Active UL + DL

simply, n v – Active = Min  N

UL

DL

 f Act N

DL

UL

 f Act 

UL

Number of users active in the uplink: n v – Active = N DL

UL

Number of users active in the downlink: n v – Active = N UL

DL

UL + DL

– n v – Active DL

UL + DL

– n v – Active

UL + DL

And, n v = n v – Active + n v – Active + n v – Active Calculation of the number of inactive users attempting to access the service v: nv Number of inactive users: n v – Inactive = ------------------------------  p Inactive 1 – p Inactive

Data Service (d) Here, Atoll considers all the users as active. Activity probabilities are not calculated. Calculation of the number of users attempting to access the service d: If N

UL

N

DL

UL + DL

n d – Active = N

UL

UL

n d – Active = 0 DL

n d – Active = N If N

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n d – Active = N

DL

DL

n d – Active = 0 UL

n d – Active = N

UL

–N

DL

nd is the total number of active users in the TXi coverage area using the service d: UL

DL

UL + DL

n d = n d – Active + n d – Active + n d – Active Note: •

9.2.7.2

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.

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 "Generating a Realistic User Distribution" on page 494. 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 

, NR UL

, SU

TX i  ic 

, and AU

TX i  ic 

) 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 517.

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Figure 9.1WiMAX 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 518. 5. Determines the permutation zone assigned to each mobile as explained in "Permutation Zone Selection (WiMAX 802.16e)" on page 519. 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 532 and "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541 respectively. The C/(I+N) is calculated in different ways depending on whether a smart antenna has been assigned to a transmitter or not. -

Without smart antennas: The downlink traffic loads of cells are used to calculate the downlink interference, i.e., the interference received from each interfering cell in the downlink is weighted by its downlink traffic load. The uplink traffic loads of interfering mobiles are used to calculate the uplink interference, i.e., the interference received from each interfering mobile in the uplink is weighted by its uplink traffic load.

-

With smart antennas: Victim and Interfering Mobiles: In WiMAX simulations, the terms victim and interfering mobiles are used for mobiles served by the victim and interfering cells respectively. In the downlink, victim mobiles receive interfering signals from interfering cells. In the uplink, victim cells receive interfering signals from interfering mobiles.

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Figure 9.2Victim and Interfering Mobiles Atoll assumes that a different beam is formed for each victim mobile. Time-Slot Scenario: For each victim mobile, instead of weighting the interference by traffic loads of the interfering mobiles or cells, a Time-Slot Scenario (TSS) is generated. A time-slot scenario is a list of interfering mobiles per victim mobile. In other words, a time-slot scenario generated for any victim mobile contains at most one (1) interfering mobile in each interfering cell. Each time-slot scenario can generate either one (1) or no (0) interfering mobile in each interfering cell for each victim mobile. One and only one time-slot scenario is generated per victim mobile. And, there are as many time-slot scenarios generated as there are victim mobiles generated during the simulation. For a given time-slot scenario, the probability that an interfering mobile is present in an interfering cell depends on the traffic loads of the potential interfering mobiles in the interfering cell. All mobiles in an interfering cell are potential interfering mobiles. Which one (1), if any, of these potential interfering mobiles is included in the time-slot scenario is determined by weighting their probability of selection by the mobile traffic loads. Interference Averaging Over Iterations: Interference is averaged over iterations of a simulation. This process considers the probabilities of collision between slots used by victim and interfering mobiles, which depend upon their transmission times, or in other words, their traffic loads. The averaging of interferences over all the iterations in a simulation gives a realistic average interference at the end of the simulation. The process is the same for uplink and downlink. In this way, Atoll simulates the simultaneous connections of victim and interfering mobiles, and considers the effect of the smart antenna, because beamforming is performed for all victim and interfering mobiles for all time-slot scenarios. Each iteration starts with the initial conditions which are the results from the previous iteration, i.e., interference information are input to each iteration. The averaging of interferences over all the iterations in a simulation is performed in a successive manner. This is done because each time-slot scenario may have a large number of interfering mobiles for each victim mobile. Successive averaging means that the interference information input to an iteration takes into account the output interference information of the preceding iteration as well as the weighted input interference information of all the previously carried out iterations. If I represents the interference information, the interference information input to the kth iteration can be given by: n k

I in

n k – 1

n k – 2

I out +    k – 2   I in = ----------------------------------------------------------------------1 +   k – 2

Where k is the iteration number, n is any given victim mobile, and  is a stability factor used to help simulations converge quickly. The stability factor is currently set to 0.2. The effect of the stability factor can be understood by the following figure.

Figure 9.3Simulation Convergence Stability Factor

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Chapter 9: WiMAX BWA Networks 7. Determines the channel throughputs at the mobile as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547. 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 551. 9. Calculates the user throughputs after allocating resources to each mobile as explained in "User Throughput Calculation" on page 557. 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

TX i  ic 

Mi

 RDL

=

and TL UL

Mi

 RUL

=

Mi

Mi TX i  ic 

For uplink MU-MIMO, TL UL



=

MU – MIMO

Mi

RC UL

MU – MIMO

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 537. Calculation of Segmentation Usage (WiMAX 802.16e): Atoll calculates the segmentation usages for all the cells as follows: Mi

 SU

TX i  ic 

Mi

M PZ

i

R DL

Mi

PZ DL = Seg

= Seg

DL = -----------------------------------------------------------------TX i  ic  TL DL

Mi



Where Mi

R DL

M PZ

is the sum of the percentages of the downlink cell resources allocated to

Mi

PZ DL = Seg

i = Seg DL

mobiles served by the segmented permutation zone. Calculation of AAS Usage: Atoll calculates the AAS usages for all the cells as follows: Mi

 AU

TX i  ic 

Where

Mi

AAS

AAS

= ------------------------------------TX i  ic  TL DL Mi

 Mi

R DL

R DL

AAS

is the sum of the percentages of the downlink cell resources allocated to mobiles served

AAS

by the smart antenna equipment. 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

MU – MIMO

Mi

Where

MU – MIMO

Mi



is the sum of the percentages of the uplink cell resources allocated to MU-MIMO

R UL

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

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TL DL

=

k

=

k

TX i  ic  TX i  ic  Max  TL UL – TL UL  k All TX  ic 

k – 1

i

TX i  ic 

NR UL

k – 1

i

TX i  ic 

TL UL

TX i  ic  TX i  ic  Max  TL DL – TL DL  k All TX  ic 

k

=



TX i  ic  TX i  ic  Max  NR UL – NR UL  k

All TX i  ic 

TX i  ic 

If TL DL



TX i  ic 

Req

, TL 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 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

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 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 UL+DL. 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.)

Connected mobiles (step 8.) can be: • • •

9.2.8

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 UL+DL: If a mobile active in UL+DL is allocated resources in UL+DL.

C/(I+N)-Based Coverage Predictions The following coverage predictions are based on the received signal levels, total noise, and interference. • • • • • • • •

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Coverage by C/(I+N) Level (DL) Coverage by Best Bearer (DL) Coverage by Throughput (DL) Coverage by Quality Indicator (DL) Coverage by C/(I+N) Level (UL) Coverage by Best Bearer (UL) Coverage by Throughput (UL) Coverage by Quality Indicator (UL)

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Chapter 9: WiMAX BWA Networks 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 noninterfering 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. Coverage prediction parameters to be set are: • •

The coverage prediction conditions, and The display settings to colour the coverage areas.

The minimum thresholds at the receiver are defined in the Display parameters. The following sections describe the determination of coverage area of each cell ("Coverage Area Determination" on page 503), the calculation of the coverage parameter ("Coverage Parameter Calculation" on page 503), and the display options ("Coverage Display" on page 504) of the coverage predictions.

9.2.8.1

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 517.

9.2.8.2

Coverage Parameter Calculation The following parameters are calculated for the Coverage by C/(I+N) Level (DL) coverage prediction. TX i  ic 

•

Preamble C/(I+N) Level (DL) (dB): CINR Preamble as explained in "Preamble C/(I+N) Calculation" on page 517.

•

Preamble Total Noise (I+N) (DL) (dBm):  I + N Preamble as explained in "Preamble C/(I+N) Calculation" on

TX i  ic 

page 517. •

TX i  ic 

Traffic C/(I+N) Level (DL) (dB): CINR Traffic as explained in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532.

•

TX i  ic 

Traffic Total Noise (I+N) (DL) (dBm):  I + N DL

as explained in "Traffic and Pilot C/(I+N) and Bearer

Calculation (DL)" on page 532. •

TX i  ic 

Pilot C/(I+N) Level (DL) (dB): CINR Pilot

as explained in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)"

on page 532. The following parameters are calculated for the Coverage by Best Bearer (DL) coverage prediction. Mi

•

Best Bearer (DL): B DL as explained in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532.

•

Modulation (DL): Modulation used by the bearer B DL calculated as explained in "Traffic and Pilot C/(I+N) and

Mi

Bearer Calculation (DL)" on page 532. The following parameters are calculated for the Coverage by Throughput (DL) coverage prediction. •

Mi

Peak MAC Channel Throughput (DL) (kbps): CTP P – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Effective MAC Channel Throughput (DL) (kbps): CTP E – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Application Channel Throughput (DL) (kbps): CTP A – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Peak MAC Cell Capacity (DL) (kbps): Cap P – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Effective MAC Channel Throughput (DL) (kbps): Cap E – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Application Channel Throughput (DL) (kbps): Cap A – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

The following parameters are calculated for the Coverage by C/(I+N) Level (UL) coverage prediction.

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Mi

•

C/(I+N) Level (UL) (dB): CINR UL as explained in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541.

•

Total Noise (I+N) (UL) (dBm):  I + N UL

TX i  ic 

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Mi

Allocated Bandwidth (UL) (No. of Subchannels): N SC – UL as explained in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541.

•

Mi

C/(I+N) Level for 1 Subchannel (UL) (dB): CINR UL as explained in "Traffic C/(I+N) and Bearer Calculation (UL)" Mi

on page 541 but by fixing N SC – UL = 1 •

Mi

Transmission Power (UL) (dBm): P Eff as explained in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541.

The following parameters are calculated for the Coverage by Best Bearer (UL) coverage prediction. Mi

•

Best Bearer (UL): B UL as explained in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541.

•

Modulation (UL): Modulation used by the bearer B UL calculated as explained in "Traffic C/(I+N) and Bearer

Mi

Calculation (UL)" on page 541. The following parameters are calculated for the Coverage by Throughput (UL) coverage prediction. •

Mi

Peak MAC Channel Throughput (UL) (kbps): CTP P – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Effective MAC Channel Throughput (UL) (kbps): CTP E – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Application Channel Throughput (UL) (kbps): CTP A – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Peak MAC Cell Capacity (UL) (kbps): Cap P – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Effective MAC Channel Throughput (UL) (kbps): Cap E – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Application Channel Throughput (UL) (kbps): Cap A – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Peak MAC Allocated Bandwidth Throughput (UL) (kbps): ABTP P – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Effective MAC Allocated Bandwidth Throughput (UL) (kbps): ABTP E – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

•

Mi

Application Allocated Bandwidth Throughput (UL) (kbps): ABTP A – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

9.2.8.3

Coverage Display

9.2.8.3.1

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 Calculations" on page 77 for more information).

9.2.8.3.2

Coverage by C/(I+N) Level (DL) Display Types 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) Atoll calculates preamble C/(I+N) levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the preamble C/(I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the preamble C/(I+N) 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 preamble C/ (I+N) level from the best server exceeds a defined threshold.

Preamble Total Noise (I+N) (DL) (dBm) Atoll calculates preamble total noise (I+N) levels received from the interfering cells on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the preamble total noise (I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the preamble total noise (I+N) level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds.

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Chapter 9: WiMAX BWA Networks Each layer corresponds to an area where the preamble total noise (I+N) level from the interfering cells exceeds a defined threshold.

Traffic C/(I+N) Level (DL) (dB) Atoll calculates traffic C/(I+N) levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the traffic C/(I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the traffic C/(I+N) 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 traffic C/(I+N) level from the best server exceeds a defined threshold.

Traffic Total Noise (I+N) (DL) (dBm) Atoll calculates traffic total noise (I+N) levels received from the interfering cells on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the traffic total noise (I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the traffic total noise (I+N) 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 traffic total noise (I+N) level from the interfering cells exceeds a defined threshold.

Pilot C/(I+N) Level (DL) (dB) Atoll calculates pilot C/(I+N) levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the pilot C/(I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the pilot C/(I+N) 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 pilot C/(I+N) level from the best server exceeds a defined threshold.

9.2.8.3.3

Coverage by Best Bearer (DL) Display Types It is possible to display the Coverage by Best Bearer (DL) coverage prediction with colours depending on the following display options.

Best Bearer (DL) Atoll determines the best bearer available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if a bearer is available (the pixel colour depends on the available bearer). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as available bearers. Each layer corresponds to an area covered by an available bearer.

Modulation (DL) Atoll determines the modulation used by the best bearer available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if a bearer is available (the pixel colour depends on the modulation used by the available bearer). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as modulation used by bearers. Each layer corresponds to an area covered the modulation used by available bearers.

9.2.8.3.4

Coverage by Throughput (DL) Display Types 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) Atoll calculates peak MAC channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the peak MAC channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the peak MAC channel throughput). 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 peak MAC channel throughput exceeds a defined threshold.

Effective MAC Channel Throughput (DL) (kbps) Atoll calculates effective MAC channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the effective MAC channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the effective MAC channel throughput). 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 effective MAC channel throughput exceeds a defined threshold.

Application Channel Throughput (DL) (kbps) Atoll calculates application channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the application channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the application channel throughput). Coverage consists of several independent layers whose visibility

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Technical Reference Guide in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the application channel throughput exceeds a defined threshold.

Peak MAC Cell Capacity (DL) (kbps) Atoll calculates peak MAC cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the peak MAC cell capacity exceeds (  ) the defined thresholds (the pixel colour depends on the peak MAC cell capacity). 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 peak MAC cell capacity exceeds a defined threshold.

Effective MAC Cell Capacity (DL) (kbps) Atoll calculates effective MAC cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the effective MAC cell capacity exceeds (  ) the defined thresholds (the pixel colour depends on the effective MAC cell capacity). 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 effective MAC cell capacity exceeds a defined threshold.

Application Cell Capacity (DL) (kbps) Atoll calculates application cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the application cell capacity exceeds (  ) the defined thresholds (the pixel colour depends on the application cell capacity). 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 application cell capacity exceeds a defined threshold.

9.2.8.3.5

Coverage by Quality Indicator (DL) Display Types It is possible to display the Coverage by Quality Indicator (DL) coverage prediction with colours depending on quality indicators available in the document (Quality Indicators table). Atoll calculates the 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. A pixel of a coverage area is coloured if the quality indicator value exceeds (  ) the defined thresholds (the pixel colour depends on the quality indicator value). 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 quality indicator value exceeds a defined threshold.

9.2.8.3.6

Coverage by C/(I+N) Level (UL) Display Types 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) Atoll calculates uplink C/(I+N) levels received at the best serving cells from each pixel of their coverage areas. A pixel of a coverage area is coloured if the uplink C/(I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the uplink C/(I+N) 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 uplink C/(I+N) level from the pixels at the best serving cells exceeds a defined threshold.

Total Noise (I+N) (UL) (dBm) Atoll calculates total noise (I+N) levels received at the best serving cells from each pixel of their coverage areas. A pixel of a coverage area is coloured if the total noise (I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the total noise (I+N) 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 total noise (I+N) level from the pixels at the best serving cells exceeds a defined threshold.

Allocated Bandwidth (UL) (No. of Subchannels) Atoll calculates the number of used subchannels at each pixel of each best serving cell’s coverage area. A pixel of a coverage area is coloured if the number of used subchannels exceeds (  ) the defined thresholds (the pixel colour depends on the number of used subchannels). 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 used subchannels at the pixels of the best serving cells exceeds a defined threshold.

C/(I+N) Level for 1 Subchannel (UL) (dB) Atoll calculates uplink C/(I+N) levels for 1 subchannel received at the best serving cells from each pixel of their coverage areas. A pixel of a coverage area is coloured if the uplink C/(I+N) level for 1 subchannel exceeds (  ) the defined thresholds (the pixel colour depends on the uplink C/(I+N) level for 1 subchannel). Coverage consists of several independent layers

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Chapter 9: WiMAX BWA Networks whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the uplink C/(I+N) level for 1 subchannel from the pixels at the best serving cells exceeds a defined threshold.

Transmission Power (UL) (dBm) Atoll calculates the uplink transmission powers corresponding to the uplink C/(I+N) received at the best serving cells from each pixel of their coverage areas. A pixel of a coverage area is coloured if the uplink transmission power exceeds (  ) the defined thresholds (the pixel colour depends on the uplink transmission power 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 uplink transmission power from the pixels at the best serving cells exceeds a defined threshold.

9.2.8.3.7

Coverage by Best Bearer (UL) Display Types It is possible to display the Coverage by Best Bearer (UL) coverage prediction with colours depending on the following display options.

Best Bearer (UL) Atoll determines the best bearer available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if a bearer is available (the pixel colour depends on the available bearer). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as available bearers. Each layer corresponds to an area covered by an available bearer.

Modulation (UL) Atoll determines the modulation used by the best bearer available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if a bearer is available (the pixel colour depends on the modulation used by the available bearer). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as modulation used by bearers. Each layer corresponds to an area covered the modulation used by available bearers.

9.2.8.3.8

Coverage by Throughput (UL) Display Types 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) Atoll calculates peak MAC channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the peak MAC channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the peak MAC channel throughput). 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 peak MAC channel throughput exceeds a defined threshold.

Effective MAC Channel Throughput (UL) (kbps) Atoll calculates effective MAC channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the effective MAC channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the effective MAC channel throughput). 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 effective MAC channel throughput exceeds a defined threshold.

Application Channel Throughput (UL) (kbps) Atoll calculates application channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the application channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the application channel throughput). 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 application channel throughput exceeds a defined threshold.

Peak MAC Cell Capacity (UL) (kbps) Atoll calculates peak MAC cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the peak MAC cell capacity exceeds (  ) the defined thresholds (the pixel colour depends on the peak MAC cell capacity). 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 peak MAC cell capacity exceeds a defined threshold.

Effective MAC Cell Capacity (UL) (kbps) Atoll calculates effective MAC cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the effective MAC cell capacity exceeds (  ) the defined thresholds (the pixel colour depends © Forsk 2010

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Technical Reference Guide on the effective MAC cell capacity). 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 effective MAC cell capacity exceeds a defined threshold.

Application Cell Capacity (UL) (kbps) Atoll calculates application cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the application cell capacity exceeds (  ) the defined thresholds (the pixel colour depends on the application cell capacity). 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 application cell capacity exceeds a defined threshold.

Peak MAC Allocated Bandwidth Throughput (UL) (kbps) Atoll calculates peak MAC allocated bandwidth throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the peak MAC allocated bandwidth throughput exceeds (  ) the defined thresholds (the pixel colour depends on the peak MAC allocated bandwidth throughput). 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 peak MAC allocated bandwidth throughput exceeds a defined threshold.

Effective MAC Allocated Bandwidth Throughput (UL) (kbps) Atoll calculates effective MAC allocated bandwidth throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the effective MAC allocated bandwidth throughput exceeds (  ) the defined thresholds (the pixel colour depends on the effective MAC allocated bandwidth throughput). 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 effective MAC allocated bandwidth throughput exceeds a defined threshold.

Application Allocated Bandwidth Throughput (UL) (kbps) Atoll calculates application allocated bandwidth throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the application allocated bandwidth throughput exceeds (  ) the defined thresholds (the pixel colour depends on the application allocated bandwidth throughput). 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 application allocated bandwidth throughput exceeds a defined threshold.

9.2.8.3.9

Coverage by Quality Indicator (UL) Display Types It is possible to display the Coverage by Quality Indicator (UL) coverage prediction with colours depending on 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 WiMAX equipment of the best serving cell. A pixel of a coverage area is coloured if the quality indicator value exceeds (  ) the defined thresholds (the pixel colour depends on the quality indicator value). 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 quality indicator value exceeds a defined threshold.

9.3

Calculation Algorithms The following sections describe all the calculation algorithms used in point analysis, calculation of coverage predictions, calculations on subscriber lists, and Monte Carlo simulations.

9.3.1

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 9.4Co-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 TX i  ic 

TX i  ic 

of N Channel , and adjacent channel interference on the adjacent channel bandwidths, i.e., corresponding to N Channel – 1 TX i  ic 

and 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 509). 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: • • •

9.3.1.1

"Co-Channel Overlap Calculation" on page 510. "Adjacent Channel Overlap Calculation" on page 510. "Total Overlap Ratio Calculation" on page 512.

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 i  ic 

N Channel

First – TX j  jc 

and N Channel

: First channel numbers the frequency band assigned to the cells TXi(ic) and

TXj(jc). •

TX i  ic 

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).

Calculations Channel numbers are converted into start and end frequencies as follows: For cell TXi(ic): TX i  ic 

F Start

© Forsk 2010

TX i  ic 

TX i  ic 

TX i  ic 

First – TX i  ic 

= F Start – FB + W Channel   N Channel – N Channel

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

509

Technical Reference Guide TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

First – TX i  ic 

TX j  jc 

TX j  jc 

TX j  jc 

First – TX j  jc 

TX j  jc 

TX j  jc 

TX j  jc 

First – TX j  jc 

= F Start – FB + W Channel   N Channel – N Channel

F End

+ 1

For cell TXj(jc): TX j  jc 

= F Start – FB + W Channel   N Channel – N Channel

F Start

TX j  jc 

= F Start – FB + W Channel   N Channel – N Channel

F End



+ 1

Output

9.3.1.2

TX i  ic 

•

F Start

•

F End

TX i  ic 

TX j  jc 

and F Start : Start frequencies for the cells TXi(ic) and TXj(jc). TX j  jc 

and F End

: End frequencies for the cells TXi(ic) and TXj(jc).

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 509. •

TX i  ic 

F End

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 509. •

TX i  ic 

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 j  jc 

TX i  ic 

= Min  F End  F End

TX j  jc 

TX i  ic 

 – Max  F Start  F Start 

The co-channel overlap ratio is given by: TX i  ic  – TX j  jc 

r CCO

TX i  ic  – TX j  jc 

W CCO = -------------------------------------TX i  ic  W Channel

Output •

9.3.1.3

TX i  ic  – TX j  jc 

r CCO

: Co-channel overlap ratio between the cells TXi(ic) and TXj(jc).

Adjacent 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 509. •

TX i  ic 

F End

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 509. •

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).

510

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Chapter 9: WiMAX BWA Networks 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 j  jc 

= Min  F End

TX i  ic 

TX j  jc 

TX i  ic 

TX i  ic 

 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  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  FEnd  F End

TX i  ic 

TX j  jc 

TX i  ic 

+ W Channel  – Max  F Start  F End



The higher-frequency adjacent channel overlap ratio is given by: TX i  ic  – TX j  jc  r ACO H

TX i  ic  – TX j  jc 

W ACO H = -------------------------------------TX i  ic  W Channel

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 •

9.3.1.4

TX i  ic  – TX j  jc 

r ACO

: Adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc).

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, co-existing 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:

Input •

TDD

r DL – Frame : Downlink subframe ratio defined in the Global Parameters.

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  ic  – TX  jc 

i j Overlap Ratio r FDD – TDD

TXi(ic)

TXj(jc)

TDD

TDD

TDD

FDD

1

FDD

TDD

TDD r DL – Frame

--------------------------100

FDD

FDD

1

1

Output •

© Forsk 2010

TX i  ic  – TX j  jc 

r FDD – TDD

: FDD – TDD overlap ratio between the cells TXi(ic) and TXj(jc).

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Technical Reference Guide

9.3.1.5

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 510. •

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 510. •

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 511. 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 i  ic 

– f ACS – FB  --------------------------- TX i  ic  – TX j  jc   TXi  ic  – TXj  jc  TX i  ic  – TX j  jc  10 + r ACO  10  r CCO   r FDD – TDD    

TX i  ic 

TX j  jc 

TX i  ic 

TX j  jc 

if W Channel  W Channel

TX i  ic 

– f ACS – FB  TX i  ic  --------------------------- TX i  ic  – TX j  jc  W Channel  TX i  ic  – TX j  jc  TX i  ic  – TX j  jc  10 ----------------------+ r ACO  10  TX  jc   r CCO   r FDD – TDD j   W Channel  

if W Channel  W Channel

TX i  ic 

W Channel - is used to normalise the transmission power of the interfering cell TXj(jc). This means The multiplicative factor ----------------------TX j  jc  W Channel TX j  jc 

that if the interfering cell transmits at X dBm over a bandwidth of W Channel , and it interferes over a bandwidth less than TX i  ic 

TX j  jc  W Channel

W Channel , the interference from this cell should not be considered at X dBm but less than that. The factor ----------------------TX j  jc  W Channel TX j  jc 

TX j  jc 

converts X dBm over W Channel to Y dBm (which is less than X dBm) over less than W Channel .

Output •

9.3.2

TX i  ic  – TX j  jc 

rO

: Total co- and adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc).

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: • • • • •

9.3.2.1

"Preamble Signal Level Calculation" on page 512. "Preamble Noise Calculation" on page 514. "Preamble C/N Calculation" on page 516. "Preamble Interference Calculation" on page 515. "Preamble C/(I+N) Calculation" on page 517.

Preamble Signal Level Calculation Input 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

•

512

TX i  ic 

•

TX i

L

TX i

TX i

: Transmitter antenna gain for the antenna used by the transmitter TXi. : Total transmitter losses for the transmitter TXi ( L

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= L Total – DL ). © Forsk 2010

Chapter 9: WiMAX BWA Networks •

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

Mi

: Receiver terminal losses for the pixel, subscriber, or mobile Mi.

Mi

•

G

•

Mi L Ant

: Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi. : 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 the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, Mi

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. Note: 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 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 i  ic 

TX i  ic 

•

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 

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

Mi

–G

Mi

Mi

Mi

+ L Ant + L Body

Note: •

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  is added to C 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

© Forsk 2010

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.

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9.3.2.2

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. In WiMAX 802.16d, the number of subcarriers used by the preamble is the same as the number of subcarriers used by the cell over the rest of the WiMAX frame. But, in WiMAX 802.16e, 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 • •

K: Boltzmann’s constant. T: Temperature in Kelvin.

•

N SCa – Preamble : Number of used subcarriers defined in the Global Parameters (WiMAX 802.16d) or the number

TX i  ic 

of subcarriers used by the preamble defined for the frame configuration of the cell TXi(ic) (WiMAX 802.16e). •

TX i  ic 

N SCa – Total : Total number of subcarriers defined in the Global Parameters (WiMAX 802.16d) or for the frame configuration of the cell TXi(ic) (WiMAX 802.16e).

•

TX i  ic 

F Sampling : Sampling frequency for the cell TXi(ic) as calculated in "Calculation of Sampling Frequency" on page 544.

•

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 For WiMAX 802.16d, 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 i  --------------------------------------= n 0 + 10  Log F Sampling  TX i  ic    N SCa – Total  

For WiMAX 802.16e, the thermal noise over the preamble for a cell is calculated as: TX i  ic   TX  ic  N SCa – Preamble Preamble TX i  ic  i -  f Segment n 0 – Preamble = n 0 + 10  Log  F Sampling  --------------------------------------TX i  ic    N SCa – Total  

Effect of Segmentation (WiMAX 802.16e): 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 segmentation on the C/N and C/(I+N) results in an increase in the coverage footprint of the preamble. Hence, the thermal noise at the pixel, subscriber, or mobile Mi covered by the preamble is reduced by Preamble 1 a factor of f Segment = --- . 3

The following table shows the different types of subcarriers and their numbers for preamble transmission in WiMAX 802.16e. N SCa – Total

Segment

Guard Subcarriers Left

Right

Total

All 128

512

0 1

10

10

N SCa – Preamble

f Segment

1 (54)

107

1

1 (54)

35

0.3271

None

36

0.3364

Preamble

2

None

36

0.3364

All

1 (214)

428

1

0 1

42

41

2

514

20

DC Subcarrier

AT283_TRG_E2

83

None

143

0.3341

1 (214)

142

0.3318

None

143

0.3341

© Forsk 2010

Chapter 9: WiMAX BWA Networks All 0

1024

86

1

172

851

1

1 (426)

283

0.3325

None

284

0.3337

2

None

284

0.3337

All

1 (852)

1703

1

1 (852)

567

0.3329

None

568

0.3335

None

568

0.3335

0

2048

86

1 (426)

172

1

172

344

2

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 •

9.3.2.3

TX i  ic 

n Preamble : Preamble noise for the cell TXi(ic).

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 (for WiMAX 802.16e) 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 512 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 477. In coverage predictions, the ratio M Shadowing – Model – M Shadowing – C  I is applied to the interfering signals (for more information, see "Shadowing Model" on page 115). 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 j  jc 

TX j  jc 

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 508. •

TX i  ic 

N Seg

TX j  jc 

and N Seg

: (WiMAX 802.16e) Segment numbers assigned to the cells TXi(ic) and TXj(jc) calculated TX i  ic 

TX j  jc 

from their respective 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:

© Forsk 2010

AT283_TRG_E2

515

Technical Reference Guide TX j  jc 

TX j  jc 

TX i  ic  – TX j  jc 

I Preamble = C Preamble + f O TX i  ic  – TX j  jc 

Where f O

TX i  ic  – TX j  jc 

+ f Seg

Inter – Tech

+ 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 

f Seg

TX i  ic  – TX j  jc 

= 10  Log  r O



is the interference reduction factor due to preamble segmentation (WiMAX 802.16e only), calculated as

follows: TX i  ic  – TX j  jc 

f Seg

TX i  ic  – TX j  jc 

= 10  Log  p Collision TX i  ic  – TX j  jc 

For WiMAX 802.16d, f Seg



= 0. TX i  ic  – TX j  jc 

The probability of preamble subcarrier collision p Collision TX i  ic  N Seg



TX j  jc  N Seg

and 1 if

TX i  ic  N Seg

=

TX j  jc  N Seg

between the cells TXi(ic) and TXj(jc) is 0 if

.

Note: TX j  jc 

•

TX j  jc 

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 TX j  jc 

antenna equipment assigned, the interference is incremented by + 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

terminal’s antenna gain for the pixel, subscriber, or mobile Mi,

Mi L Ant

Mi

is the receiver

is the receiver terminal’s antenna attenuation

Mi

calculated for the pixel, subscriber, or mobile Mi, and L Body is the body loss defined for the service used by the pixel, subscriber, or mobile Mi.

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).

9.3.2.4

Preamble C/N Calculation Input •

TX i  ic 

C Preamble : Received preamble signal level from the cell TXi(ic) as calculated in "Preamble Signal Level Calculation" on page 512.

•

516

TX i  ic 

n Preamble : Preamble noise for the cell TXi(ic) as calculated in "Preamble Noise Calculation" on page 514.

AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks

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 

CNR Preamble = C Preamble – n Preamble

Output •

9.3.2.5

TX i  ic 

CNR Preamble : Preamble C/N from the cell TXi(ic) at any pixel, subscriber, or mobile Mi.

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 512) 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 515). Interference from each cell is weighted according to the co- and adjacent channel overlap between the studied and the interfering cells, and (in WiMAX 802.16e) 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 514). 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 512. TX i  ic 

•

n Preamble : Preamble noise for the cell TXi(ic) as calculated in "Preamble Noise Calculation" on page 514.

•

I Preamble : Preamble interference received from any cell TXj(jc) at a pixel, subscriber, or mobile Mi covered by a

TX j  jc 

cell TXi(ic) as calculated in "Preamble Interference Calculation" on page 515. •

Inter – Tech

NR DL

: Inter-technology downlink noise rise.

Calculations The preamble C/(I+N) for a cell TXi(ic) is calculated as follows at any pixel, subscriber, or mobile Mi: TX i  ic 

n Preamble  TXj  jc      I Preamble ---------------------------  ------------------------  10 Inter – Tech = –  10  Log  10   + 10  + NR DL   10      All TX  jc        j The preamble total noise (I+N) for a cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX i  ic  CINR Preamble

TX i  ic  C Preamble



TX  ic  i

TX i  ic 

 I + N  Preamble

n Preamble  TXj  jc    --------------------------- I Preamble  ------------------------ Inter – Tech 10 = 10  Log  10   + 10  + NR DL  10      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).

9.3.3

Best Server Determination In WiMAX, best server refers to a cell ("serving transmitter"-"reference cell" pair) from which a pixel, subscriber, or mobile TX i  ic 

Mi gets the highest preamble signal level ( C Preamble ). This calculation also determines whether the pixel, subscriber, or mobile Mi is within the coverage area of any transmitter or not.

© Forsk 2010

AT283_TRG_E2

517

Technical Reference Guide

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 512 using the terminal and service parameters ( L

Mi

, G

Mi

Mi

, L Ant ,

Mi

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 preamble signal level is i

the highest among the preamble signal levels received from all the cells. The best server is determined as follows: BS M = TX i  ic  i

TX  ic  i

C Preamble =

Best All TX  ic  i

 TXi  ic    C Preamble   

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 lowest 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 lowest 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 lowest cell layer, the 2nd mobile to the second lowest cell layer, and so on.

•

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. •

Min DL Traffic Load: (Not implemented yet) The cell with the lowest downlink traffic load is selected as the serving (reference) cell. If more than one cell has the same lowest downlink traffic load, the first cell among all such cells is selected. During Monte Carlo simulations, as the cell traffic loads may vary, the serving cell for mobiles may also change from one iteration to the next. Min UL Traffic Load: (Not implemented yet) The cell with the lowest uplink traffic load is selected as the serving (reference) cell. If more than one cell has the same lowest uplink traffic load, the first cell among all such cells is selected. During Monte Carlo simulations, as the cell traffic loads may vary, the serving cell for mobiles may also change from one iteration to the next.

•

The Min DL Traffic Load and Min UL Traffic Load options model load balancing between cells. In coverage predictions as the probe mobile selects the least loaded cell, i.e., tries to keep the traffic load balanced between cells of the transmitter. Instead of loading already loaded cells even more, the base station chooses to load the least loaded among them.

Output •

9.3.4

BS M : Best serving cell of the pixel, subscriber, or mobile Mi. i

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 517) 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 516.

•

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 i  ic 

TX i  ic 

CNR Preamble  T Preamble

518

AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks

Output • •

9.3.5

True: If the calculation criterion is satisfied. False: Otherwise.

Permutation Zone Selection (WiMAX 802.16e) 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 518) 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 i  ic 

: 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 i  ic  CNR Preamble

•

TX i  ic  CINR Preamble

•

page 517. Mobility  M i  : Speed of the pixel, subscriber, or mobile Mi.

M i – TX i  ic 

: 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 516. : Preamble C/(I+N) from the cell TXi(ic) as calculated in "Preamble C/(I+N) Calculation" on

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: •

The distance between Mi and TXi(ic) is less than or equal to the maximum distance covered by the permutation zone: d

•

M i – TX i  ic 

TX i  ic 

 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 i  ic 

TX i  ic 

CNR Preamble  QT PZ •

TX i  ic 

TX i  ic 

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

© Forsk 2010

     TXi  ic  = Highest Priority  PZ DL     

     TXi  ic  = Highest Priority  PZ UL     

d 

M – TX  ic  i i



TX  ic  i d Max – PZ

TX  ic  TX  ic    i i  CNR Preamble  QT PZ    AND  OR    TX  ic  TX  ic    i i  CINR Preamble  QT PZ 

TX  ic  TX  ic    i i  CNR Preamble  QT PZ  M – TX  ic  TX  ic    i i d i   d AND OR   Max – PZ     TX  ic  TX  ic    i i  CINR Preamble  QT PZ 

AT283_TRG_E2

        TX  ic  i AND  Mobility  M i   Speed Max – PZ   

        TX  ic  i   AND  Mobility  M i   Speed Max – PZ   

519

Technical Reference Guide 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 •

9.3.6

Mi

Mi

PZ DL and PZUL : Downlink and uplink permutation zones assigned to the pixel, subscriber, or mobile Mi.

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. • • • • • • • • • •

9.3.6.1

"Traffic and Pilot Signal Level Calculation (DL)" on page 520. "Traffic and Pilot Noise Calculation (DL)" on page 521. "Traffic and Pilot Interference Calculation (DL)" on page 522. "Traffic and Pilot C/N Calculation (DL)" on page 530. "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532. "Traffic Signal Level Calculation (UL)" on page 534. "Traffic Noise Calculation (UL)" on page 535. "Traffic Interference Calculation (UL)" on page 536. "Traffic C/N Calculation (UL)" on page 537. "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541.

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).

•

P Pilot

•

TX i  ic  TX i  ic 

G

TX i

: Pilot power reduction of the cell TXi(ic).

: Transmitter antenna gain for the antenna used by the transmitter TXi.

-

Without smart antennas: G

-

With smart antennas: G i.e., 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,

= G SA    . Where  is the direction in which Mi is located. For more information on the calculation

of G SA    , refer to section "Smart Antenna Models" on page 558. TX i

: Total transmitter losses for the transmitter TXi ( L

TX i

•

L

= L Total – DL ).

•

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

: Receiver terminal losses for the pixel, subscriber, or mobile Mi.

Mi

•

G

•

Mi L Ant

: Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi. : 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 the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, Mi

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. •

520

Mi

L Body : Body loss defined for the service used by the pixel, subscriber, or mobile Mi.

AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks

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 

C Traffic = EIRP Traffic – L Path – M Shadowing – Model – L Indoor + G TX i  ic 

TX i  ic 

C Pilot

= EIRP Pilot

– L Path – M Shadowing – Model – L Indoor + G

Mi

Mi

–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 

EIRP Traffic = P Traffic + G TX i  ic 

TX i  ic 

With P Traffic and P Pilot TX i  ic 

TX i  ic 

TX i

–L

TX i

TX i  ic 

and EIRP Pilot

TX i  ic 

= P Pilot

+G

TX i

–L

TX i

being the traffic and pilot transmission powers of the cell TXi(ic) calculated as follows: TX i  ic 

TX i  ic 

P Traffic = P Preamble – P Traffic and P Pilot

TX i  ic 

TX i  ic 

= P Preamble – P Pilot

Note: 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  is added to C 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

9.3.6.2

TX i  ic 

•

C Traffic : Received traffic signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.

•

C Pilot

TX i  ic 

: Received pilot signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.

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. In WiMAX 802.16e, the numbers of subcarriers used by each permutation zone 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. N SCa – Used : Number of used subcarriers defined in the Global Parameters (WiMAX 802.16d).

•

N SCa – Total : Total number of subcarriers defined in the Global Parameters (WiMAX 802.16d).

•

N SCa – Used : Number of subcarriers used by the downlink permutation zone of a WiMAX 802.16e cell TXi(ic)

M

i

PZ DL

assigned to Mi. TX i  ic 

•

N SCa – Total : Total number of subcarriers defined for the frame configuration of a WiMAX 802.16e cell TXi(ic).

•

F Sampling : Sampling frequency for the cell TXi(ic) as calculated in "Calculation of Sampling Frequency" on

TX i  ic 

page 544. •

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 a cell is calculated as:

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Technical Reference Guide TX i  ic  TX i  ic  N SCa – Used WiMAX 802.16d: n 0 – DL = n 0 + 10  Log  F Sampling  ------------------------------  N SCa – Total M

WiMAX 802.16e:

TX i  ic  n 0 – DL

i   PZ DL N SCa – Used  TX i  ic  ----------------------------= n 0 + 10  Log  F Sampling  TX  ic   i  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 (WiMAX 802.16e): If you select the Segmentation Support check box in the Frame Configurations table 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 segmenting factor, f Segment , is calculated from the number of secondary subchannel groups assigned to the permutation zone in the Permutation Zones table. 3  PSG + 2  SSG f Segment = ---------------------------------------------------15 Where, PSG is the number of primary subchannel groups and SSG is the number of used secondary subchannel groups. Note: •

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 represents the fraction of the channel bandwidth used by a segment. The power transmitted over a 1 segment has ---------------------- times the spectral density of the power transmitted over the entire channel bandwidth. f Segment 1 When calculating the downlink C/N and C/(I+N) ratios, the increase in power by ---------------------- due to this power f Segment concentration is equivalent to a reduction in the noise level by f Segment . Hence, if segmentation is used, the thermal noise power at the pixel, subscriber, or mobile Mi covered by the segmented permutation zone is reduced by a factor of f Segment . Which means that the thermal noise for the a segment of the channel used by a cell is calculated as: M

TX i  ic  n 0 – DL

i   PZ DL N SCa – Used  TX i  ic   ---------------------------- f Segment = n 0 + 10  Log  F Sampling  TX  ic  i   N SCa – Total  

Output •

9.3.6.3

TX i  ic 

n DL

: Downlink noise for the cell TXi(ic).

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 segmentation or not. Moreover, the interference can come from cells using classical as well as smart antennas. The calculation can be divided into the two parts. • •

522

"Traffic and Pilot Interference Signal Levels Calculation (DL)" on page 523. "Effective Traffic and Pilot Interference Calculation (DL)" on page 527.

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Chapter 9: WiMAX BWA Networks

9.3.6.3.1

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 TX j  jc 

•

P Preamble : Preamble transmission power of the cell TXj(jc).

•

P Pilot

•

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

•

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 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.

TX j  jc 

: Pilot power reduction of the interfering cell TXj(jc).

TX j  jc  TX j  jc 

TX j

: Total transmitter losses for the transmitter TXj ( L

TX j

= L Total – DL ).

TX j

TX j

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

: Receiver terminal losses for the pixel, subscriber, or mobile Mi.

Mi

•

G

•

Mi L Ant

: Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi. : Receiver terminal’s antenna attenuation calculated for the pixel, subscriber, or mobile Mi.

Mi

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 j  jc 

: 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 498. •

AU

TX j  jc 

: AAS usage ratio of the interfering cell TXj(jc).

AAS usage ratios are calculated using Monte Carlo simulations as explained in "Simulation Process" on page 498. •

TX j  jc 

N SCa – Used : Number of used subcarriers defined in the global parameters for WiMAX 802.16d or for the first downlink permutation zone in the frame configuration assigned to the interfering cell TXj(jc) in WiMAX 802.16e.

•

TX j  jc 

N SCa – Data : Number of data subcarriers defined in the global parameters for WiMAX 802.16d or for the first downlink permutation zone in the frame configuration assigned to the interfering cell TXj(jc) in WiMAX 802.16e.

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:

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Technical Reference Guide TX  jc  j

TX j  jc 

Without smart antennas: I Total

TX  jc  j

I Idle   I Non – AAS ------------------  -------------------------10 10 + 10 = 10  Log  10      TX  jc  j

With smart antennas:

•

TX j  jc  I Total

 I AAS   ----------------10  = 10  Log  10     

Coverage Predictions: 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  j

TX  jc  j

TX  jc  j

I Idle I AAS   INon – AAS -----------------------------------  -------------------------10 10 10 + 10 + 10 = 10  Log  10     

TX j  jc 

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

: Interference from the loaded part of the frame transmitted using the smart antenna,

•

TX j  jc  I Idle

: Interference from the empty, or idle, part of the frame.

TX j  jc 

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 

I Traffic = EIRP Traffic – L Path – M Shadowing – Model – L Indoor + G TX j  jc 

TX j  jc 

I Pilot

= EIRP Pilot

– L Path – M Shadowing – Model – L Indoor + G

Mi

Mi

–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 

I Traffic = EIRP Traffic – L Path – M Shadowing – Model + M Shadowing – C  I – L Indoor + G TX j  jc 

TX j  jc 

I Pilot

= EIRP Pilot

– L Path – M Shadowing – Model + M Shadowing – C  I – L Indoor + G

Mi

Mi

–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 j  jc 

TX j  jc 

TX j

–L

TX j

TX j  jc 

and EIRP Pilot

TX j

+G

TX j

–L

TX j

being the traffic and pilot transmission powers of the cell TXj(jc) calculated as follows: TX j  jc 

TX j  jc 

P Traffic = P Preamble – P Traffic and P Pilot And G

TX j  jc 

= P Pilot

TX j  jc 

TX j  jc 

= 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  j

TX j  jc 

I Non – AAS

524

TX  jc  j

I Pilot  I Traffic   TX j  jc  TX j  jc  ------------------  TX j  jc  N SCa – Data  ---------------- TX j  jc  N SCa – Data    10 - + 10 10   1 – ----------------------------   10  ----------------------------  1 – AU = 10  Log  TL DL TX j  jc      TX j  jc    N SCa – Used N  SCa – Used    

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Chapter 9: WiMAX BWA Networks Note: •

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 j  jc 

TX j  jc 

+ 10  Log  N Ant – TX  . Where N Ant – TX is the number of MIMO transmission (downlink) antennas defined for the cell TXj(jc). 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 

TX j  jc 

I AAS

= EIRP AAS

– L Path – M Shadowing – Model – L Indoor + G

Mi

–L

Mi

Mi

Mi

– L Ant – L Body

In coverage prediction: TX j  jc 

TX j  jc 

I AAS

= EIRP AAS

– 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 

TX j  jc 

EIRP AAS

= 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

is the smart antenna gain in the direction of the victim mobile Mi, calculated as follows:

Monte Carlo Simulations: G

TX j

= G SA    is calculated in the direction of the victim mobile Mi, while the smart antenna at the interfering

cell has a beam formed in the direction of an interfering mobile Mj.  is the direction, with respect to the azimuth of the cell TXj(jc), in which the victim mobile Mi is located. For more information on the calculation of G SA    , refer to section "Smart Antenna Models" on page 558. Victim and interfering mobiles are generated by a time-slot scenario as explained in "Simulation Process" on page 498. TX i  ic 

1

2

In the figure below, G SA    is calculated from the victim cell TXi(ic) to calculate C Traffic , and G SA    is TX j  jc 

calculated from the interfering cell TXj(jc) to calculate I AAS

. In other words, a beam is formed from the victim

cell towards the victim mobile, and a beam is formed by the interfering cell towards the interfering mobile.

Figure 9.5Downlink C/(I+N) calculation in Simulations -

Coverage Predictions: G

TX j

= G SA    is calculated in the direction of the victim mobile Mi from the angular distribution of the

downlink traffic power density available at the end of the simulations. The angular distribution of the downlink traffic power density, which represents the average array correlation matrix, is calculated during Monte Carlo simulations and can be stored in the Cells table.  is the direction in which the victim pixel or subscriber Mi is located. For more information on the calculation of G SA    , refer to section "Smart Antenna Models" on page 558.

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Technical Reference Guide TX i  ic 

1

2

In the figure below, G SA    is calculated from the victim cell TXi(ic) to calculate C Traffic , and G SA    is TX j  jc 

calculated from the interfering cell TXj(jc) to calculate I AAS

. In other words, a beam is formed from the victim

cell towards the victim pixel or subscriber, and the interference is calculated from the simulation results.

Figure 9.6Downlink C/(I+N) calculation in Coverage Predictions The average array correlation matrix (at the interfering cell) are given by: J

R Avg =

 j  pj  Rj j=1

Where R Avg is the average array correlation matrix, J is the number of served mobiles during the simulation,  j is the probability of presence of the mobile j, p j is the EIRP transmitted towards the mobile j, and R j is the array correlation matrix for the mobile j. The probability of presence of the mobile j is the ratio between the downlink resources provided to the mobile j and the total amount of available downlink resources. For example, if a mobile has been granted 10% of the number of available slots in the downlink subframe, it’s probability of presence is 10%. 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 transformation, R Avg is the average array correlation matrix, and g n    is the gain of the nth antenna element in the direction of  . 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  j

TX j  jc  I Idle

526

 I Idle – Pilot    TX j  jc  TX j  jc   ------------------------- N SCa – Data    10   1 – -----------------------------  = 10  Log   1 – TL DL    10   TX j  jc    N SCa – Used     

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Chapter 9: WiMAX BWA Networks Note: •

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 j  jc 

TX j  jc 

+ 10  Log  N Ant – TX  . Where N Ant – TX is the number of MIMO transmission (downlink) antennas defined for the cell TXj(jc).

Output •

9.3.6.3.2

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 segmentation parameters of the studied and interfering cells (WiMAX 802.16e). 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 523.

•

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 508. •

SU

TX i  ic 

and SU

TX j  jc 

: Segmentation usage ratios defined for WiMAX 802.16e 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

TX i  ic  – TX j  jc 

For WiMAX 802.16d, f Seg

Inter – Tech

+ I DL

= 0.

Calculations for the interference reduction factors due to channel overlapping and 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 segmentation (WiMAX 802.16e): If you select the Segmentation Support check box in the Frame Configurations table 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 calculating f Segment 1 the C/(I+N) ratio, the increase in power by ---------------------- is equivalent to decreasing the noise and interference by f Segment f Segment . Hence, if 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 . 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.

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Technical Reference Guide The 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 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 segmentation usage ratios stored in the cell properties for determining the interference. In simulations, Atoll resets the segmentation usage ratios for all the cells to 0, and then calculates the segmentation usage ratios according to the traffic loads of the mobiles allocated to the segmented zone and in the non-segmented zones.

Figure 9.7Segmentation Atoll determines the switching point between the segmented and the non-segmented zones using the 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 = ------------------------------------------------------------------------------------------------ and TX i  ic  TX i  ic  TX i  ic  SU + f Segment   1 – SU 

TX j  jc 

SU = -----------------------------------------------------------------------------------------------TX j  jc  TX j  jc  TX j  jc  SU + f Segment   1 – SU 

TX j  jc 

Where, SP is the switching point between the segmented and the non-segmented zones, SU is the segmentation usage ratios of the cells, and f Segment is segmenting factor, which gives the bandwidth used by a segment. The segmenting factor, f Segment , is calculated from the number of secondary subchannel groups assigned to the first downlink PUSC permutation zone in the Permutation Zones table. 3  PSG + 2  SSG f Segment = ---------------------------------------------------15 Where, PSG is the number of primary subchannel groups and SSG is the number of secondary subchannel groups. Note: •

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.

If the 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 segmentation usage ratio. Derivation of the switching point formula: •

The 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  TL DL  1 – SU   TL DL ------------------------------------------------------------------= ---------------------------------------------------SP  f Segment  W Channel  1 – SP   W Channel

With cells using segmentation, there can be four different interference scenarios.

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Chapter 9: WiMAX BWA Networks -

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 9.8Segmentation 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 subchannel groups in the cell TXi(ic), and SSG TXi(ic).

TX i  ic 

TX i  ic 

is the number of primary

is the number of secondary subchannel groups in the cell

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. -

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 i  ic  – TX j  jc 

p Collision

-

© Forsk 2010

TX j  jc  TX i  ic   SS p Coll If SP  SP   TX j  jc  TX i  ic  TX j  jc  =  SS SN + p Coll   SP – SP  TX  jc  TX i  ic  p Coll  SP  --------------------------------------------------------------------------------------------------------------------------- If SP j  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:

AT283_TRG_E2

529

Technical Reference Guide

TX i  ic  – TX j  jc 

p Collision

TX j  jc  TX i  ic   NN p Coll If SP  SP   TX j  jc  TX j  jc  TX i  ic  NS =  NN  + p Coll   SP – SP  TX j  jc  TX i  ic  Coll   1 – SP  p -----------------------------------------------------------------------------------------------------------------------------------------If SP  SP TX i  ic    1 – SP  

The interference reduction factor due to segmentation for the pixel, subscriber, or mobile Mi is calculated as follows: TX i  ic  – TX j  jc 

f Seg Inter – Tech

I DL

TX i  ic  – TX j  jc 

= 10  Log  p Collision



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

terminal’s antenna gain for the pixel, subscriber, or mobile Mi, calculated for the pixel, subscriber, or mobile Mi, and

Mi L Body

Mi L Ant

Mi

is the receiver

is the receiver terminal’s antenna attenuation

is the body loss defined for the service used by the pixel,

subscriber, or mobile Mi.

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).

9.3.6.4

Traffic and Pilot C/N Calculation (DL) Input •

TX i  ic 

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 520.

•

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 520. TX i  ic 

•

n DL

: Downlink noise for the cell TXi(ic) as calculated in "Traffic and Pilot Noise Calculation (DL)" on page 521.

•

CNR Preamble : Preamble C/N from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Preamble

TX i  ic 

C/N Calculation" on page 516. 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,

Mi

Mi

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,

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 (WiMAX 802.16e)" on page 519. •

Mi

BLER  B DL  : 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.

530

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Chapter 9: WiMAX BWA Networks

Calculations The traffic and pilot C/N for a cell TXi(ic) are calculated as follows for any pixel, subscriber, or mobile Mi: TX i  ic 

TX i  ic 

TX i  ic 

CNR Traffic = C Traffic – n DL TX i  ic 

CNR Pilot

TX i  ic 

= C Pilot

TX i  ic 

– 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 less than or equal to the highest bearer index 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

TX i  ic 

Mi

TX i  ic 

Mi

DL

If the cell supports STTD/MRC or AMS, the STTD/MRC gain, G STTD , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the WiMAX equipment assigned to the pixel, TX i  ic 

Mi

Mi

subscriber, or mobile Mi for N Ant – TX , N Ant – RX , the subchannel allocation mode of PZ DL , Mobility  M i  , Mi

BLER  B DL  . DL

The additional STTD/MRC gain defined for the clutter class of the pixel, subscriber, or mobile Mi G STTD is also applied. Therefore, the bearers available for selection are all the bearers defined in the WiMAX equipment for which the following is true: In case of STTD/MRC: Mi

DL

DL

TX i  ic 

Mi

DL

DL

TX i  ic 

T B – G STTD – G STTD  CNR Traffic T B – G STTD – G STTD  CNR Pilot In case of AMS: Mi

DL

DL

TX i  ic 

Mi

DL

DL

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

T B – G STTD – G STTD  CNR Traffic if CNR Preamble  T AMS T B – G STTD – G STTD  CNR Pilot

if CNR Preamble  T AMS

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

or CINR Preamble  T AMS or CINR Preamble  T AMS

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, and Allocated Bandwidth Throughput Calculation" on page 547.

-

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, and Allocated Bandwidth Throughput Calculation" on page 547.

MIMO – STTD/MRC Gain: Once the bearer is known, the traffic and pilot C/N calculated above become: In case of STTD/MRC: TX i  ic 

TX i  ic 

DL

DL

DL

DL

DL

DL

CNR Traffic = CNR Traffic + G STTD + G STTD TX i  ic 

CNR Pilot

TX i  ic 

= CNR Pilot

+ G STTD + G STTD

In case of AMS: TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

CNR Traffic = CNR Traffic + G STTD + G STTD if CNR Preamble  T AMS

© Forsk 2010

AT283_TRG_E2

TX i  ic 

TX i  ic 

or CINR Preamble  T AMS

531

Technical Reference Guide TX i  ic 

TX i  ic 

CNR Pilot

= CNR Pilot

DL

DL

TX i  ic 

TX i  ic 

+ G STTD + G STTD if CNR Preamble  T AMS

TX i  ic 

TX i  ic 

or CINR Preamble  T AMS

DL

Where G STTD is the STTD/MRC gain corresponding to the selected bearer.

Output

9.3.6.5

TX i  ic 

•

CNR Traffic : Traffic C/N from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.

•

CNR Pilot

TX i  ic 

: Pilot C/N from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.

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 520) 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 522). 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 (in WiMAX 802.16e) the probabilities of subcarrier collision if 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 521). 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 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 520.

•

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 520. TX i  ic 

•

n DL

•

TX j  jc  I DL

: Downlink noise for the cell TXi(ic) as calculated in "Traffic and Pilot Noise Calculation (DL)" on page 521.

: 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 522. Inter – Tech

•

NR DL

•

CNR Preamble : Preamble C/N from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Preamble

: Inter-technology downlink noise rise.

TX i  ic 

C/N Calculation" on page 516. 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,

Mi

Mi

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,

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 (WiMAX 802.16e)" on page 519. •

Mi

BLER  B DL  : 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/(I+N) for a cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX i  ic  CINR Traffic

532

=

TX i  ic  C Traffic

TX  ic   TXj  jc     i n DL DL  I----------------  Inter – Tech - -------------------- –  10  Log  10  +   and 10  + NR DL  10  10        All TXj  jc    



AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks TX  ic   TXj  jc     i n DL DL  I----------------  Inter – Tech - ------------------- –  10  Log  10  +   10  + NR DL  10  10     All TX  jc        j The Traffic Total Noise (I+N) for a cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi:

TX i  ic 

TX i  ic 

CINR Pilot



= C Pilot

TX i  ic 

I +

TX i  ic  N  DL

n DL  TXj  jc    ------------------DL  I---------------- 10  Inter – Tech - = 10  Log  10  + 10   + NR DL  10      All TXj  jc   



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 less than or equal to the highest bearer index 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

Mi

TX i  ic 

TX i  ic 

Mi

T B  CINR Pilot

DL

If the cell supports STTD/MRC or AMS, the STTD/MRC gain, G STTD , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the WiMAX equipment assigned to the pixel, TX i  ic 

Mi

Mi

subscriber, or mobile Mi for N Ant – TX , N Ant – RX , the subchannel allocation mode of PZ DL , Mobility  M i  , Mi

BLER  B DL  . DL

The additional STTD/MRC gain defined for the clutter class of the pixel, subscriber, or mobile Mi G STTD is also applied. Therefore, the bearers available for selection are all the bearers defined in the WiMAX equipment for which the following is true: In case of STTD/MRC: Mi

DL

DL

TX i  ic 

Mi

DL

DL

TX i  ic 

T B – G STTD – G STTD  CINR Traffic T B – G STTD – G STTD  CINR Pilot In case of AMS: Mi

DL

DL

TX i  ic 

Mi

DL

DL

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

T B – G STTD – G STTD  CINR Traffic if CNR Preamble  T AMS T B – G STTD – G STTD  CINR Pilot

if CNR Preamble  T AMS

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

or CINR Preamble  T AMS or CINR Preamble  T AMS

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, and Allocated Bandwidth Throughput Calculation" on page 547.

-

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, and Allocated Bandwidth Throughput Calculation" on page 547.

MIMO – STTD/MRC Gain: Once the bearer is known, the traffic and pilot C/(I+N) calculated above become: In case of STTD/MRC: TX i  ic 

TX i  ic 

DL

DL

DL

DL

CINR Traffic = CINR Traffic + G STTD + G STTD TX i  ic 

CINR Pilot

© Forsk 2010

TX i  ic 

= CINR Pilot

+ G STTD + G STTD

AT283_TRG_E2

533

Technical Reference Guide In case of AMS: TX i  ic 

TX i  ic 

DL

DL

TX i  ic 

TX i  ic 

DL

DL

TX i  ic 

TX i  ic 

CINR Traffic = CINR Traffic + G STTD + G STTD if CNR Preamble  T AMS TX i  ic 

TX i  ic 

CINR Pilot

= CINR Pilot

+ G STTD + G STTD if CNR Preamble  T AMS

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

or CINR Preamble  T AMS or CINR Preamble  T AMS

DL

Where G STTD is the STTD/MRC 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

•

TX i  ic 

I +

: Pilot C/(I+N) from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.

TX i  ic  N  DL

: Traffic Total noise from the interfering cells TXj(jc) at the pixel, subscriber, or mobile Mi covered by

a cell TXi(ic). •

9.3.6.6

Mi

B DL : Bearer assigned to the pixel, subscriber, or mobile Mi in the downlink.

Traffic 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.

•

Mi

P Eff : Effective transmission power of the terminal used by the pixel, subscriber, or mobile Mi after power control as calculated in "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541. TX 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 G

TX i

smart

TX i

antennas:

is the transmitter antenna gain, i.e., G

G

TX i

is

the

uplink

smart

TX i

TX i

= G Ant .

antenna

beamforming

gain,

i.e.,

TX i

= G SA = 10  Log  E SA  . For more information on the calculation of G SA , refer to section "Smart

Antenna Models" on page 558. •

L

TX i

: Total transmitter losses for the transmitter TXi ( L TX i L Ant

TX i

= L Total – UL ).

•

L Path : Path loss ( L Path = L Model +

•

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

Mi

: Receiver terminal losses for the pixel, subscriber, or mobile Mi.

Mi

•

G

•

Mi L Ant

: Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi. : 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 the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, Mi

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. •

534

Mi

L Body : Body loss defined for the service used by the pixel, subscriber, or mobile Mi.

AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks

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 •

9.3.6.7

Mi

C UL : Received uplink signal level from the pixel, subscriber, or mobile Mi at a cell TXi(ic).

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. In WiMAX 802.16e, the numbers of subcarriers used by each permutation zone 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.

Input • • •

K: Boltzmann’s constant. T: Temperature in Kelvin. N SCa – Used : Number of used subcarriers defined in the Global Parameters (WiMAX 802.16d).

•

N SCa – Total : Total number of subcarriers defined in the Global Parameters (WiMAX 802.16d).

•

N SCa – Used : Number of subcarriers used by the uplink permutation zone of a WiMAX 802.16e cell TXi(ic)

Mi

PZ UL

assigned to Mi. TX i  ic 

•

N SCa – Total : Total number of subcarriers defined for the frame configuration of a WiMAX 802.16e cell TXi(ic).

•

F Sampling : Sampling frequency for the cell TXi(ic) as calculated in "Calculation of Sampling Frequency" on

TX i  ic 

page 544. •

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 a cell is calculated as: N SCa – Used TX i  ic  TX i  ic  WiMAX 802.16d: n 0 – UL = n 0 + 10  Log  F Sampling  ------------------------------  N SCa – Total M

WiMAX 802.16e (UL):

TX i  ic  n 0 – UL

i   PZ UL N SCa – Used  TX i  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 •

© Forsk 2010

TX i  ic 

n UL

: Uplink noise for the cell TXi(ic).

AT283_TRG_E2

535

Technical Reference Guide

9.3.6.8

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: • •

9.3.6.8.1

Calculation of the uplink interference from each individual interfering mobile as explained in "Traffic Interference Signal Levels Calculation (UL)" on page 536. 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 537.

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 534. 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 534. In coverage predictions, the ratio M Shadowing – Model – M Shadowing – C  I is applied to the interfering signals (for more information, see "Shadowing Model" on page 115). 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 : Mj

Mj

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 508. •

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 551.

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

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: -

Without smart antennas: All the mobiles present in other cells TXj(jc) that are transmitting in uplink contribute to the interference received by TXi(ic) in uplink. Mj

Mj

f TL – UL = 10  Log  TL UL 

536

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© Forsk 2010

Chapter 9: WiMAX BWA Networks -

With smart antennas: A set of interfering mobiles is generated for each mobile being served by the victim cell TXi(ic). The probability of generating a mobile as an interferer depends on its uplink traffic load (see "TimeSlot Scenario:" on page 500). As the traffic load has already been taken into account for generating the list of interfering mobiles, Mj

f TL – UL = 0

Output •

9.3.6.8.2

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 536. TX i  ic 

•

n UL

•

Inter – Tech NR UL

: Uplink noise for the cell TXi(ic) as calculated in "Traffic Noise Calculation (UL)" on page 535. : 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:

TX i  ic 

NR UL

 TX  ic  i n UL  Mj    ------------------I UL TX i  ic   ------ 10  Inter – Tech = 10  Log  – n UL  10  + 10  + NR UL  10      All Mj    All TX  jc  

 j

TX i  ic  N UL

I +

 TXi  ic  n UL  Mj    ------------------UL  I------ 10  Inter – Tech = 10  Log   10  + 10  + NR UL  10      All Mj    All TX  jc  

 j

•

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 NR UL    = ----------------------------------2 n  I TX i  ic 

 I + N UL

2

   = I UL    +  n  I

Output • •

9.3.6.9

TX i  ic 

NR UL I +

TX i  ic 

or NR UL

TX i  ic  N UL

   : Uplink noise rise or the angular distribution of the uplink noise rise for the cell TXi(ic). TX i  ic 

or  I + N  UL

   : Total Noise for a cell TXi(ic) calculated for any pixel, subscriber, or mobile Mi.

Traffic 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 "Traffic Signal Level Calculation (UL)" on page 534.

•

© Forsk 2010

TX i  ic 

n UL

: Uplink noise for the cell TXi(ic) as calculated in "Traffic Noise Calculation (UL)" on page 535. AT283_TRG_E2

537

Technical Reference Guide TX i  ic 

•

CNR Preamble : Preamble C/N from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Preamble C/N Calculation" on page 516. TX i  ic 

•

T AMS : AMS threshold defined for the cell TXi(ic).

•

N SC – UL : Number of subchannels per channel (WiMAX 802.16d).

•

T B – Lowest : Bearer selection threshold of the lowest bearer in the WiMAX equipment assigned to the cell TXi(ic).

•

PZ UL N SC

TX i  ic  M

i

: 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 (WiMAX 802.16e)" on page 519. Mi

•

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 Parameters.

•

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,

Mi

Mi

Mi

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

Mi

mobile Mi as calculated in "Permutation Zone Selection (WiMAX 802.16e)" on page 519. Mi

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: Mi

Mi

TX i  ic 

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 less than or equal to the highest bearer index 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

UL

If the cell supports STTD/MRC or AMS, the STTD/MRC gain, G STTD , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the WiMAX equipment assigned to the cell TX i  ic 

Mi

Mi

Mi

TXi(ic) for N Ant – TX , N Ant – RX , the subchannel allocation mode of PZ UL , Mobility  M i  , BLER  B UL  . UL

The additional STTD/MRC gain defined for the clutter class of the pixel, subscriber, or mobile Mi G STTD is also applied. Therefore, the bearers available for selection are all the bearers defined in the WiMAX equipment for which the following is true: In case of STTD/MRC: Mi

UL

UL

Mi

UL

Mi

T B – G STTD – G STTD  CNR UL In case of AMS: Mi

UL

TX i  ic 

TX i  ic 

T B – G STTD – G STTD  CNR UL if CNR Preamble  T AMS

TX i  ic 

TX i  ic 

or CINR Preamble  T AMS

The bearer selected for data transfer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic).

538

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Chapter 9: WiMAX BWA Networks -

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, and Allocated Bandwidth Throughput Calculation" on page 547.

-

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, and Allocated Bandwidth Throughput Calculation" on page 547.

MIMO – STTD/MRC Gain: Once the bearer is known, the uplink C/N calculated above become: In case of STTD/MRC: Mi

Mi

UL

UL

Mi

UL

UL

CNR UL = CNR UL + G STTD + G STTD In case of AMS: Mi

TX i  ic 

TX i  ic 

CNR UL = CNR UL + G STTD + G STTD if CNR Preamble  T AMS

TX i  ic 

TX i  ic 

or CINR Preamble  T AMS

UL

Where G STTD is the STTD/MRC gain corresponding to the selected bearer. Uplink Subchannelisation (WiMAX 802.16d): Subchannelisation decreases the bandwidth used by a mobile hence increasing the power spectral density for transmission, and decreasing the noise and interference received. WiMAX terminals can perform subchannelisation in uplink to improve uplink coverage. In WiMAX 802.16d networks, if a terminal is unable to connect to its serving cell using all 16 subchannels, it can use less number of subchannels (8, 4, 2, or 1) in the uplink in order to concentrate its transmission power on a smaller bandwidth, hence increasing its power spectral density and increasing transmission range. The uplink C/N is calculated above using the number of subchannels per channel set in the Global Parameters, which is 16 by default. The number of subchannels in uplink is provided by the IEEE specifications. N SC – UL = 16 8 4 2 or 1 If the uplink C/N before subchannelisation from the pixel, subscriber, or mobile Mi is not enough to get the lowest Mi

TX i  ic 

bearer, i.e., CNR UL  T B – Lowest , Atoll performs subchannelisation as follows: All SC Mi

TX i  ic 

Until CNR UL  T B – Lowest AND N SC – UL  1 , Final Mi

Mi

Atoll improves the uplink C/N by adding the subchannelisation gain to it: CNR UL = CNR UL + G SC – UL Final

All SC

And reduces the number of subchannels used in the uplink N SC – UL by half. The value of G SC – UL is calculated by determining the number of used subcarriers as follows:

Subchannelisation From

Number of Used Subcarriers

G SC – UL

16 to 8

200 to 100. (192 Data + 8 Pilot to 96 Data + 4 Pilot)

200 10  Log  ---------- = 3 dB  100

8 to 4

100 to 50. (96 Data + 4 Pilot to 48 Data + 2 Pilot)

100 10  Log  ---------- = 3 dB  50 

4 to 2

50 to 25. (48 Data + 2 Pilot to 25 Data + 1 Pilot)

50 10  Log  ------ = 3 dB  25

2 to 1

25 to 13. (24 Data + 1 Pilot to 12 Data + 1 Pilot)

25 10  Log  ------ = 2.84 dB  13

Even if after performing subchannelisation, the uplink C/N from the pixel, subscriber, or mobile Mi is not enough Mi

TX i  ic 

to get a bearer in the uplink, i.e., CNR UL  T B – Lowest , the pixel, subscriber, or mobile Mi is considered not covered Final

by the cell TXi(ic) in the uplink.

© Forsk 2010

AT283_TRG_E2

539

Technical Reference Guide If you want to turn off subchannelisation in uplink, you can set the number of subchannels per channel to 1 in the Global Parameters. Uplink Subchannelisation (WiMAX 802.16e): 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 M

i

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/N.

-

Maintain Connection The bandwidth used for transmission by a mobile is reduced only if the uplink C/N is not enough to 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. The definition of the lowest bearer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic), i.e., bearer with the lowest index, with the lowest peak MAC throughput, or with the lowest effective MAC throughput.

-

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 M

Mi

i

PZ UL

of subchannels associated with the permutation zone, i.e., N SC – UL  N SC

. The gain related to this bandwidth

reduction is applied to the uplink C/N: M

Mi CNR UL Final

=

Mi CNR UL + All SC

 PZULi   N SC  - 10  Log  ------------------- N Mi   SC – UL

Uplink Power Control: Once the subchannelisation is performed, Atoll continues to work with the C/N given by the subchannelisation, Mi

Mi

i.e., 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  M

i B UL

+ M PC , where T

TX i  ic  M

i

is the bearer selection threshold, from the

B UL

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: TX i  ic 

P Eff = Max  P Max –  CNR UL –  T M   B i  Mi

Mi

Mi

Mi + M PC   P Min  

UL

Mi

Mi

CNR UL is calculated again using P Eff .

Output •

540

Mi

CNR UL : Uplink C/N from a pixel, subscriber, or mobile Mi at it serving cell TXi(ic).

AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks

9.3.6.10

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 534. Next, Atoll calculates the uplink carrier to noise ratio as explained in "Traffic C/N Calculation (UL)" on page 537. 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 537. 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 537. TX i  ic 

TX i  ic 

or NR UL

   : Uplink noise rise or the angular distribution of the uplink noise rise for the cell TXi(ic).

•

NR UL

•

CNR Preamble : Preamble C/N from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "Preamble

TX i  ic 

C/N Calculation" on page 516. TX i  ic 

•

T AMS : AMS threshold defined for the cell TXi(ic).

•

N SC – UL : Number of subchannels per channel (WiMAX 802.16d).

•

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 (WiMAX 802.16e)" on page 519. Mi

•

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 Parameters.

•

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,

Mi

Mi

Mi

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

Mi

mobile Mi as calculated in "Permutation Zone Selection (WiMAX 802.16e)" on page 519. •

Mi

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/(I+N) for any pixel, subscriber, or mobile Mi at a cell TXi(ic) is calculated as follows: •

Without smart antennas: Mi

Mi

TX i  ic 

CINR UL = CNR UL – NR UL •

With smart antennas: -

Monte Carlo simulations: The uplink C/(I+N) is calculated as described in the section "Smart Antenna Models" on page 558. Victim and interfering mobiles are generated by a time-slot scenario as explained in "Simulation Process" on page 498.

-

Coverage predictions: CINR UL    = CNR UL – NR UL

Mi

Mi

TX i  ic 



Bearer Determination:

© Forsk 2010

AT283_TRG_E2

541

Technical Reference Guide 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 less than or equal to the highest bearer index 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

UL

If the cell supports STTD/MRC or AMS, the STTD/MRC gain, G STTD , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the WiMAX equipment assigned to the cell TX i  ic 

Mi

Mi

Mi

TXi(ic) for N Ant – TX , N Ant – RX , the subchannel allocation mode of PZ UL , Mobility  M i  , BLER  B UL  . UL

The additional STTD/MRC gain defined for the clutter class of the pixel, subscriber, or mobile Mi G STTD is also applied. Therefore, the bearers available for selection are all the bearers defined in the WiMAX equipment for which the following is true: In case of STTD/MRC: Mi

UL

UL

Mi

Mi

UL

UL

Mi

UL

UL

Mi

UL

UL

Mi

T B – G STTD – G STTD  CINR UL and T B – G STTD – G STTD  CINR UL    In case of AMS: Mi

TX i  ic 

TX i  ic 

T B – G STTD – G STTD  CINR UL if CNR Preamble  T AMS

TX i  ic 

TX i  ic 

or CINR Preamble  T AMS

and Mi

TX i  ic 

TX i  ic 

T B – G STTD – G STTD  CINR UL    if CNR Preamble  T AMS

TX i  ic 

TX i  ic 

or CINR Preamble  T AMS

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, and Allocated Bandwidth Throughput Calculation" on page 547.

-

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, and Allocated Bandwidth Throughput Calculation" on page 547.

MIMO – STTD/MRC Gain: Once the bearer is known, the uplink C/(I+N) calculated above become: In case of STTD/MRC: Mi

Mi

UL

UL

CINR UL = CINR UL + G STTD + G STTD and Mi

Mi

UL

UL

CINR UL    = CINR UL    + G STTD + G STTD In case of AMS: Mi

Mi

UL

TX i  ic 

UL

TX i  ic 

CINR UL = CINR UL + G STTD + G STTD if CNR Preamble  T AMS

TX i  ic 

TX i  ic 

or CINR Preamble  T AMS

and Mi

Mi

UL

UL

TX i  ic 

TX i  ic 

CINR UL    = CINR UL    + G STTD + G STTD if CNR Preamble  T AMS

TX i  ic 

TX i  ic 

or CINR Preamble  T AMS

UL

Where G STTD is the STTD/MRC gain corresponding to the selected bearer. Uplink Subchannelisation (WiMAX 802.16d): Subchannelisation decreases the bandwidth used by a mobile hence increasing the power spectral density for transmission, and decreasing the noise and interference received. WiMAX terminals can perform

542

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© Forsk 2010

Chapter 9: WiMAX BWA Networks subchannelisation in uplink to improve uplink coverage. In WiMAX 802.16d networks, if a terminal is unable to connect to its serving cell using all 16 subchannels, it can use less number of subchannels (8, 4, 2, or 1) in the uplink in order to concentrate its transmission power on a smaller bandwidth, hence increasing its power spectral density and increasing transmission range. The uplink C/(I+N) is calculated above using the number of subchannels per channel set in the Global Parameters, which is 16 by default. The number of subchannels in uplink is provided by the IEEE specifications. N SC – UL = 16 8 4 2 or 1 If the uplink C/(I+N) before subchannelisation from the pixel, subscriber, or mobile Mi is not enough to get the TX i  ic 

Mi

lowest bearer, i.e., CINR UL  T B – Lowest , Atoll performs subchannelisation as follows: All SC Mi

TX i  ic 

Until CINR UL  T B – Lowest AND N SC – UL  1 , Final Mi

Mi

Atoll improves the uplink C/(I+N) by adding the subchannelisation gain to it: CINR UL = CINR UL + G SC – UL All SC

Final

And reduces the number of subchannels used in the uplink N SC – UL by half. The value of G SC – UL is calculated by determining the number of used subcarriers as follows:

Subchannelisation From

Number of Used Subcarriers

G SC – UL

16 to 8

200 to 100. (192 Data + 8 Pilot to 96 Data + 4 Pilot)

200 10  Log  ---------- = 3 dB  100

8 to 4

100 to 50. (96 Data + 4 Pilot to 48 Data + 2 Pilot)

100 10  Log  ---------- = 3 dB  50 

4 to 2

50 to 25. (48 Data + 2 Pilot to 25 Data + 1 Pilot)

50 10  Log  ------ = 3 dB  25

2 to 1

25 to 13. (24 Data + 1 Pilot to 12 Data + 1 Pilot)

25 10  Log  ------ = 2.84 dB  13

Even if after performing subchannelisation, the uplink C/(I+N) from the pixel, subscriber, or mobile Mi is not enough Mi

TX i  ic 

to get a bearer in the uplink, i.e., CINR UL  T B – Lowest , the pixel, subscriber, or mobile Mi is considered as not Final

covered by the cell TXi(ic) in the uplink. If you want to turn off subchannelisation in uplink, you can set the number of subchannels per channel to 1 in the Global Parameters. Uplink Subchannelisation (WiMAX 802.16e): 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 Mi

PZ UL

the 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 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. The definition of the lowest bearer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic), i.e., bearer with the lowest index, with the lowest peak MAC throughput, or with the lowest effective MAC throughput.

-

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

© Forsk 2010

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543

Technical Reference Guide 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 Mi

Mi

PZ UL

of subchannels associated with the permutation zone, i.e., N SC – UL  N SC

. The gain related to this bandwidth

reduction is applied to the uplink C/(I+N): M

Mi CINR UL Final

=

Mi CINR UL + All SC

 PZULi   N SC  10  Log  --------------------  N Mi  SC – UL  

Uplink Power Control: Once the subchannelisation is performed, Atoll continues to work with the C/(I+N) given by the subchannelisation, Mi

Mi

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  M

i

B UL

+ M PC , where T

TX i  ic  M

i

is the bearer selection threshold, from the

B UL

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: TX i  ic  Mi Mi Mi Mi P Eff = Max  P Max –  CINR UL –  T M + M PC   P Min   B i    UL

Mi

Mi

CINR UL is calculated again using P Eff .

Output

9.3.7

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 Mi

Throughput Calculation Throughputs are calculated in two steps. • •

9.3.7.1

Calculation of uplink and downlink total resources in a cell as explained in "Calculation of Total Cell Resources" on page 544. Calculation of throughputs as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 547.

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.

9.3.7.1.1

Calculation of Sampling Frequency Input

544

TX i  ic 

•

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 

AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks

Calculations Atoll determines the sampling frequency as follows: TX i  ic 

6

W Channel  10  TX i  ic   F Sampling = Floor  f Sampling  ----------------------------------------  8000 8000  

Output •

9.3.7.1.2

TX i  ic 

F Sampling : Sampling frequency for the cell TXi(ic).

Calculation of Symbol Duration Input •

TX i  ic 

F Sampling : Sampling frequency for the cell TXi(ic) as calculated in "Calculation of Sampling Frequency" on page 544. TX i  ic 

•

N SCa – Total : Total number of subcarriers defined for the frame configuration of a WiMAX 802.16e cell TXi(ic).

•

r CP : Cyclic prefix ratio defined for the network in the Global Parameters.

Calculations From the sampling frequency, Atoll determines the inter-subcarrier spacing. F

TX i  ic 

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 i  ic  F

And, the duration of the cyclic prefix. r CP D CP = -------F Adding the Cyclic prefix ratio to the useful symbol duration, Atoll determines the total symbol duration. TX i  ic 

TX i  ic 

D Symbol = D Sym – Useful + D CP

Output •

9.3.7.1.3

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

TDD TDD

TX i  ic 

Duration" on page 545.

© Forsk 2010

TDD

•

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 DL DL UL UL

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Technical Reference Guide TX i  ic 

•

N SCa – Data : Number of data subcarriers for a WiMAX 802.16d cell TXi(ic).

•

N SCa – Data : Number of data subcarriers of the downlink permutation zone of a WiMAX 802.16e cell TXi(ic)

M

i

PZ DL

assigned to Mi. M

•

i

PZ UL N SCa – Data

: Number of data subcarriers of the uplink permutation zone of a WiMAX 802.16e cell TXi(ic) assigned

to Mi.

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 i  ic  Frame  N  SD – Used   Frame = Floor  ------------------- TXi  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 Parameters: TX i  ic 

TX i  ic 

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

N SD – DL TX i  ic   TX i  ic   DL Or N  SD – DL   Subframe = RoundUp  N  SD – Used   Frame  ------------------------------------------------ – O Fixed if DL:UL ratio is defined TDD TDD  N SD – DL + N SD – UL in 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: DL

TX i  ic 

TX i  ic  TX i  ic   O Variable   TX i  ic  = N  Sym – DL   Subframe = Floor  N  SD – DL   Subframe  N SCa – Data   1 – ---------------------- 100    

TX i  ic 

i TX i  ic  PZ DL  O Variable   TX i  ic  = N  Sym – DL   Subframe = Floor  N  SD – DL   Subframe  N SCa – Data   1 – ---------------------- 100    

WiMAX 802.16d: R DL

WiMAX 802.16e: R DL

M

DL

Uplink Subframe: Atoll calculates the number of symbol durations in the uplink subframe excluding the fixed overhead defined in the Global Parameters: TX i  ic 

TX i  ic 

TDD

UL

N  SD – UL   Subframe = RoundDown  N  SD – Used   Frame   1 – r DL – Frame   – O Fixed if DL:UL ratio is defined in percentage. TDD

Or

N SD – UL TX i  ic   TX i  ic   UL N  SD – UL   Subframe = RoundDown  N  SD – Used   Frame  ------------------------------------------------ – O Fixed TDD TDD  N SD – DL + N SD – UL

if DL:UL ratio is

defined in 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 i  ic  TX i  ic   O Variable   TX i  ic  = N  Sym – UL   Subframe = Floor  N  SD – UL   Subframe  N SCa – Data   1 – ---------------------- 100    

TX i  ic 

i TX i  ic  PZ UL  O Variable   TX i  ic  = N  Sym – UL   Subframe = Floor  N  SD – UL   Subframe  N SCa – Data   1 – ---------------------- 100    

WiMAX 802.16e: R UL

546

UL

TX i  ic 

WiMAX 802.16d: R UL

M

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© Forsk 2010

Chapter 9: WiMAX BWA Networks

Output

9.3.7.1.4

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.

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

TX i  ic 

Duration" on page 545. X

•

O Fixed : Downlink or uplink fixed overhead.

•

O Variable : Downlink or uplink variable overhead.

•

N SCa – Data : Number of data subcarriers for a WiMAX 802.16d cell TXi(ic).

•

N SCa – Data : Number of data subcarriers of the downlink or uplink permutation zone of a WiMAX 802.16e cell

X

TX i  ic  M

PZ X

i

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 i  ic  Subframe - – OX N  SD – X   Subframe = Floor  ------------------------Fixed  TXi  ic    D Symbol  The total numbers of symbols in the downlink or uplink subframes after removing the variable overheads are: X

TX i  ic 

TX i  ic  TX i  ic   O Variable   TX i  ic  = N  Sym – X   Subframe = Floor  N  SD – X   Subframe  N SCa – Data   1 – ---------------------- 100    

TX i  ic 

TX i  ic  PZ X  O Variable   TXi  ic  = N  Sym – X   Subframe = Floor  N  SD – X   Subframe  N SCa – Data   1 – ---------------------- 100    

WiMAX 802.16d: R X

WiMAX 802.16e: R X

M

i

X

Output •

9.3.7.2

TX i  ic 

RX

TX i  ic 

= N  Sym – X   Subframe : Amount of downlink or uplink resources in the cell TXi(ic).

Channel Throughput, Cell Capacity, and Allocated Bandwidth 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.

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 544.

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AT283_TRG_E2

547

Technical Reference Guide TX i  ic 

•

R UL

•

page 544.  M : Bearer efficiency (bits/symbol) of the bearer assigned to the pixel, subscriber, or mobile Mi in the downlink

: Amount of uplink resources in the cell TXi(ic) as calculated in "Calculation of Total Cell Resources" on

i

B DL

•

in "Traffic and Pilot C/(I+N) and Bearer Calculation (DL)" on page 532.  M : Bearer efficiency (bits/symbol) of the bearer assigned to the pixel, subscriber, or mobile Mi in the uplink in i

B UL

• •

"Traffic C/(I+N) and Bearer Calculation (UL)" on page 541. D Frame : Frame duration. f Segment : Segmenting factor for the first downlink PUSC zone as calculated in "Effective Traffic and Pilot Interference Calculation (DL)" on page 527. TX i  ic 

•

CNR Preamble : Preamble C/N the cell TXi(ic) as calculated in "Preamble C/N Calculation" on page 516.

•

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).

•

BLER  B DL  : Downlink block error rate read from the BLER vs. CINR Traffic graph available in the WiMAX

TX i  ic  TX i  ic 

TX i  ic 

TX i  ic 

Mi

equipment assigned to the terminal used by the pixel, subscriber, or mobile Mi. •

Mi

Mi

BLER  B UL  : 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. Mi

•

TP Offset : Throughput offset defined in the properties of the service used by the pixel, subscriber, or mobile Mi.

•

N SC

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 (WiMAX 802.16e)" on page 519. •

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 541.

Calculations Downlink: TX i  ic 

•

Peak MAC Channel Throughput:

Mi CTP P – DL

R DL



M

B

i

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. Segmentation (WiMAX 802.16e): Mi

If the permutation zone assigned to the pixel, subscriber, or mobile Mi is the first downlink PUSC zone ( PZDL = 0 ) and it is segmented, the channel throughput is calculated as: TX i  ic 

Mi CTP P – DL

R DL



M

B

i

DL -  f Segment = -----------------------------------D Frame

MIMO – SU-MIMO Gain: If the permutation zone assigned to the pixel, subscriber, or mobile Mi (WiMAX 802.16e) or the cell (WiMAX Max

802.16d) supports SU-MIMO or AMS, SU-MIMO gain 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 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,

Mi

subscriber, or mobile Mi.

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Chapter 9: WiMAX BWA Networks -

Mobility  M i  : Mobility used for the calculations.

-

Subchannel allocation mode used by the downlink permutation zone PZ DL assigned to the pixel, subscriber,

Mi

or mobile Mi as calculated in "Permutation Zone Selection (WiMAX 802.16e)" on page 519. -

Mi

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 532.

-

Mi

BLER  B DL  : Downlink block error rate read from the graphs available in the WiMAX equipment assigned to TX i  ic 

the 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: 

M

i

In

case

of

AMS:

Max

= 

B DL

M

i

B DL



Mi

Max

= 

B DL TX i  ic 

  1 + f SU – MIMO  G SU – MIMO – 1  

Mi

B DL

  1 + f SU – MIMO  G SU – MIMO – 1  

if

TX i  ic 

TX i  ic 

CNR Preamble  T AMS

or

TX i  ic 

CINR Preamble  T AMS

If the Max SU-MIMO Gain for the exact value of the C/(I+N) is not availabe 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). Mi

Mi

Mi

•

Effective MAC Channel Throughput: CTP E – DL = CTP P – DL   1 – BLER  B DL  

•

Mi Mi f TP – Scaling Mi Application Channel Throughput: CTP A – DL = CTP E – DL  ----------------------------- – TP Offset 100

•

Peak MAC Cell Capacity: Cap P – DL = CTP P – DL  TL DL – Max

•

Effective MAC Cell Capacity: Cap E – DL = Cap P – DL   1 – BLER  B DL  

•

Mi Mi f TP – Scaling Mi Application Cell Capacity: Cap A – DL = Cap E – DL  ----------------------------- – TP Offset 100

Mi

Mi

TX i  ic 

Mi

Mi

Mi

Mi

Mi

Uplink: TX i  ic 

•

Peak MAC Channel Throughput:

Mi CTP P – UL

R 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. MIMO – SU-MIMO Gain: If the permutation zone assigned to the pixel, subscriber, or mobile Mi (WiMAX 802.16e) or the cell (WiMAX Max

802.16d) supports SU-MIMO or AMS, SU-MIMO gain 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 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 PZUL assigned to the pixel, subscriber, or

Mi

mobile Mi as calculated in "Permutation Zone Selection (WiMAX 802.16e)" on page 519. -

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 541.

-

Mi

BLER  B UL  : Uplink block error rate read from the graphs available in the WiMAX equipment assigned to the Mi

cell TXi(ic). BLER is determined for CINR UL .

© Forsk 2010

AT283_TRG_E2

549

Technical Reference Guide 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

Mi

B UL



AMS:

TX i  ic 

Max

= 

Mi

B UL

M

i B UL

  1 + f SU – MIMO  G SU – MIMO – 1  

= 

Max

M

i B UL

  1 + f SU – MIMO  G SU – MIMO – 1  

TX i  ic 

TX i  ic 

CNR Preamble  T AMS

if

or

TX i  ic 

CINR Preamble  T AMS

If the Max SU-MIMO Gain for the exact value of the C/(I+N) is not availabe 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 (WiMAX 802.16e) or the cell (WiMAX TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

802.16d) supports MU-MIMO and 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). TX i  ic 

M

R UL



M

B

i

TX  ic 

i UL -  G MUi – MIMO CTP P – UL = -----------------------------------D Frame

Mi

Mi

Mi

•

Effective MAC Channel Throughput: CTP E – UL = CTP P – UL   1 – BLER  B UL  

•

Mi Mi f TP – Scaling Mi Application Channel Throughput: CTP A – UL = CTP E – UL  ----------------------------- – TP Offset 100

•

Peak MAC Cell Capacity: Cap P – UL = CTP P – UL  TL UL – Max

•

Effective MAC Cell Capacity: Cap E – UL = Cap P – UL   1 – BLER  B UL  

•

f TP – Scaling Mi Mi Mi Application Cell Capacity: Cap A – UL = Cap E – UL  ----------------------------- – TP Offset 100

•

N SC – UL Mi Mi Peak MAC Allocated Bandwidth Throughput: ABTP P – UL = CTP P – UL  -------------------M

Mi

Mi

TX i  ic 

Mi

Mi

Mi

Mi

Mi

Mi

i

PZ UL

N SC Mi

Mi

Mi

•

Effective MAC Allocated Bandwidth Throughput: ABTP E – UL = ABTP P – UL   1 – BLER  B UL  

•

Mi Mi Mi f TP – Scaling Application Allocated Bandwidth Throughput: ABTP A – UL = ABTP E – UL  ----------------------------- – TP Offset 100

Mi

Output

550

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.

•

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.

•

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.

Mi Mi

Mi Mi Mi

Mi Mi Mi

Mi Mi Mi

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Chapter 9: WiMAX BWA Networks

9.3.8

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.

Mi Mi

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 551 and the calculation of user throughputs is explained in "User Throughput Calculation" on page 557.

9.3.8.1

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 

Mi

Mi

: QoS class of the service (UGS, ErtPS, rtPS, nrtPS, or Best Effort) accessed by a mobile Mi.

•

p

: Priority of the service accessed by a mobile Mi.

•

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.

•

BLER  B DL  : Downlink block error rate read from the BLER vs. CINR Traffic graph available in the WiMAX

Mi Mi Mi Mi

TX i  ic 

Mi

equipment assigned to the terminal used by the mobile Mi. •

Mi

Mi

BLER  B UL  : 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"

Mi

Mi

on page 544. •

Mi

CTP P – UL : Uplink peak MAC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on page 544.

•

Mi

ABTP P – UL : Uplink peak MAC allocated bandwidth throughput at the mobile Mi as calculated in "Throughput Calculation" on page 544.

•

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 i  ic 

The scheduler selects N Users mobiles for the scheduling and RRM process. If the Monte Carlo user distribution has TX i  ic 

generated a number of users which is less than N Users – Max , the scheduler keeps all the mobiles generated for the cell TXi(ic). TX i  ic 

TX i  ic 

TX i  ic 

N Users = Min  N Users – Max N Users – Generated 

© Forsk 2010

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For a cell, mobiles M i

TX i  ic 

 N Users are selected for RRM by the scheduler.

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

Sel

Mi

Mi

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 MAC Throughput Sel

Sel

Mi TPD Min – DL

Downlink:

Sel

Mi

Sel

Sel

Sel

Uplink:

•

Mi TPD Min – UL

Mi

Sel

Mi TPD Min – DL TPD Max – DL , TPD Max – DL = --------------------------------------------------= --------------------------------------------------Sel Sel Mi   1 – BLER  B  1 – BLER  B M i    DL    DL    

Mi TPD Min – UL

Sel

, = --------------------------------------------------Sel  1 – BLER  B Mi     UL  

Mi TPD Max – UL

Min  TPD Max – UL ABTP P – UL   = ---------------------------------------------------------------------------------Sel Mi  1 – BLER  B    UL   Mi

Mi

Target Throughput = Application Throughput Sel

Mi Mi Sel Mi TPD Min – DL + TP Offset TPD Min – DL = -------------------------------------------------------------------------------------Sel  1 – BLER  B Mi    f Mi   DL   TP – Scaling

Downlink:

Sel

Sel

Uplink:

Mi TPD Min – UL

Mi

,

Mi

TPD Min – UL + TP Offset = --------------------------------------------------------------------------------------, Sel  1 – BLER  B Mi    f Mi   UL   TP – Scaling Sel

Min  TPD Max – UL ABTP P – UL + TP Offset   = --------------------------------------------------------------------------------------------------------------Sel Mi Mi   f  1 – BLER  B  UL   TP – Scaling  Mi

Sel

Mi TPD Max – UL

Sel

Mi Mi Sel Mi TPD Max – DL + TP Offset TPD Max – DL = -------------------------------------------------------------------------------------Sel  1 – BLER  B Mi    f Mi   DL   TP – Scaling

Mi

Mi

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 541. Resource Allocation for Minimum Throughput Demands: Sel

1. For the QoS classes UGS, ErtPS, rtPS, and nrtPS, Atoll sorts the M i

TX i  ic 

 N Users in order of decreasing service

Sel

priority, p

Mi

: Sel

Sel

Mi

QoS

1

UGS

2

p

Mi

Sel

p

Mi

... n > p

=n Sel Mi

> 0 ...

Sel

:

p

:

ErtPS

Mi

=0

Sel

p

Mi

=n Sel

:

... n > p

Mi

> 0 ...

Sel

:

p

:

rtPS

p

Mi

=0

Sel Mi

=n

Sel

:

552

Sel

Mi

... n > p

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© Forsk 2010

Chapter 9: WiMAX BWA Networks Sel

:

p

:

nrtPS

N–1

p

Mi

=0

Sel Mi

... n > p

=n

Sel Mi

> 0 ...

Sel

N

p

TX i  ic 

Mi

=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

Sel

2. Starting with M i

= 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

Sel

Mi

Sel

Mi

Sel

Mi TPD Min – DL TPD Min – UL = ------------------------------ and R Min – UL = -----------------------------Sel Sel

Mi R Min – DL

Mi

Mi

CTP P – DL

CTP P – UL

3. Atoll stops the resource allocation in downlink or uplink, Sel

-

TX i  ic 

Mi

 RMin – DL = TLDL – Max , i.e., the resources available in downlink have been used up

When/If in downlink

Sel

Mi

for satisfying the minimum throughput demands of the mobiles. -

When/If in uplink



Sel

TX i  ic 

Mi

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 UL+DL must be able to get their minimum throughput demands in both UL and DL in order to be considered connected UL+DL. If an active UL+DL 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

Sel

Mi

Mi

bandwidth throughput ( TPD Min – UL  ABTP P – UL ) are rejected due to Resource Saturation. 6. If



Sel

TX i  ic 

Mi



R Min – DL  TL DL – Max or

Sel

Sel

TX i  ic 

Mi

R Min – UL  TL UL – Max , and all the minimum throughput resources demanded

Sel

Mi

Mi

by the mobiles have been allocated, Atoll goes to the next step for allocating resources to satisfy the maximum throughput demands. The remaining cell resources available for the next step are: TX i  ic 

TX i  ic 

Downlink: R Rem – DL = TL DL – Max –



Sel

Mi

R Min – DL

Sel

Mi TX i  ic 

Sel

TX i  ic 

Uplink: R Rem – UL = TL UL – Max –

Mi

 RMin – UL Sel

Mi

Resource Allocation for Maximum Throughput Demands: 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

Sel

Mi

Sel

Mi

Mi

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: 1. 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.

© Forsk 2010

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Technical Reference Guide 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

Sel

Mi RD Rem – DL

Sel

Mi

Mi

Sel

Mi TPD Rem – DL TPD Rem – UL and RD Rem – UL = --------------------------------= --------------------------------Sel Sel Mi

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 Proportional Fair scheduling method for satisfying its maximum throughput demands are: TX i  ic 

TX i  ic 

Sel Sel Sel Sel R Rem – DL R Rem – UL Mi Mi Mi Mi   R Max – DL = 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. d. Atoll stops the resource allocation in downlink or uplink, -



When/If in downlink

Sel

TX i  ic 

Mi

R Max – DL = R Rem – DL , i.e., the resources available in downlink have been used

Sel

Mi

up for satisfying the maximum throughput demands of the mobiles. Sel

-

TX i  ic 

Mi

 RMax – UL = RRem – UL , i.e., the resources available in uplink have been used up for

When/If in uplink

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

Sel

TX i  ic 

TX i  ic 



Sel

Mi

R Max – DL and

Sel

Mi

R Rem – UL = TL UL – Max –



R Min – DL –

Mi Sel Mi



R Min – UL –

Sel

Sel

Mi

R Max – UL

Sel

Mi

Mi

g. Atoll repeats the all the above steps for the users whose maximum throughput demands have not been TX i  ic 

TX i  ic 

satisfied until either R Rem – DL = 0 and R Rem – UL = 0 , or all the maximum throughput demands are satisfied. 2. 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

Sel

Mi RD Rem – DL

Sel

Mi

Sel

Mi

Mi TPD Rem – DL TPD Rem – UL and RD Rem – UL = --------------------------------= --------------------------------Sel Sel Mi

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  ic  TX i  ic  i R Eff – Rem – DL = Min  R Rem – DL  

554

Sel   TX  ic  Mi TX i  ic  i RD Rem – DL and R Eff – Rem – UL = Min  R Rem – UL     Sel

Sel  Mi RD Rem – UL   Sel





Mi

Mi

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© Forsk 2010

Chapter 9: WiMAX BWA Networks c. The resources allocated to each user by the Proportional Demand scheduling method for satisfying its maximum throughput demands are: Sel

Sel

Mi R Max – DL

=

Sel

Mi

Mi

Sel RD Rem – DL Mi TX i  ic  RD Rem – UL - and R Max  --------------------------------------– UL = R Eff – Rem – UL  --------------------------------------Sel Sel

TX i  ic  R Eff – Rem – DL

Mi

Mi

 RDRem – DL

 RDRem – UL

Sel

Sel

Mi

Mi

3. 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: Sel

Sel

Mi

QoS

Sel

Mi

Mi

f Bias R Max – rtPS R Max – nrtPS R Max – ErtPS  = 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: r

TX i  ic  R QoS – DL

=

TX i  ic  R Rem – DL

r

1 QoS 1 QoS N QoS   --- N QoS   ---     TX i  ic  TX i  ic  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

Sel

Mi RD Rem – DL

Sel

Mi

Sel

Mi

Mi TPD Rem – DL TPD Rem – UL and RD Rem – UL = --------------------------------= --------------------------------Sel Sel Mi

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: TX i  ic 

TX i  ic 

Sel Sel Sel Sel Mi Mi Mi Mi R QoS – DL R QoS – UL   R Max – DL = Min  RD Rem – DL ------------------------ and R Max – 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, © Forsk 2010

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Technical Reference Guide

-



When/If in downlink

Sel

TX i  ic 

Mi

R Max – DL = R QoS – DL , i.e., the resources available in downlink for the QoS class

Sel

Mi

have been used up for satisfying the maximum throughput demands of the mobiles. Sel

-

TX i  ic 

Mi

 RMax – UL = RQoS – UL , i.e., the resources available in uplink for the QoS class have

When/If in uplink

Sel

Mi

been 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

Sel

TX i  ic 

TX i  ic 



Sel

Mi

R Max – DL and

Sel

Mi

R QoS – UL = TL UL – Max –



R Min – DL –

Mi Sel Mi



R Min – UL –

Sel

Sel

Mi

R Max – UL

Sel

Mi

Mi

g. Atoll repeats the all the above steps for the users of the QoS class whose maximum throughput demands TX i  ic 

TX i  ic 

have not been satisfied until either R QoS – DL = 0 and R QoS – UL = 0 , or all the maximum throughput demands are satisfied. 4. Max Aggregate Throughput: 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 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

Sel

Mi R Max – DL

Sel

Mi

Mi

Sel

Mi TPD Rem – DL TPD Rem – UL and R Max – UL = --------------------------------= --------------------------------Sel Sel Mi

Mi

CTP P – DL

CTP P – UL

c. Atoll stops the resource allocation in downlink or uplink, -

When/If in downlink



Sel

TX i  ic 

Mi

R Max – DL = R Rem – DL , i.e., the resources available in downlink have been used

Sel

Mi

up for satisfying the maximum throughput demands of the mobiles. Sel

-

When/If in uplink

Mi

TX i  ic 

 RMax – UL = RRem – 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 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 (WiMAX 802.16e) or the TX i  ic 

TX i  ic 

TX i  ic 

cell (WiMAX 802.16d) supports MU-MIMO, CNR Preamble  T MU – MIMO , and N Ant – RX  2 . Let i be the index of connected MU-MIMO mobiles: i = 1 to N

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Chapter 9: WiMAX BWA Networks MU – MIMO

MU – MIMO

Each mobile M i

MU – MIMO Mi = 0

Mi

has a corresponding traffic load TL UL

. The scheduling starts with available real MU – MIMO Mi = 0

= 100 % and available virtual resources V UL

resources RR UL

= 0 % . i = 0 means no MU-MIMO

mobile has yet been scheduled. MU – MIMO

MU – MIMO

The virtual resource consumption of a mobile M i

Mi

is given by: VC UL

MU – MIMO

= Min  TL UL  Mi

MU – MIMO

MU – MIMO

The real resource consumption of a mobile M i

Mi

is given by: RC UL

MU – MIMO

The virtual resources made available by the mobile M i MU – MIMO

MU – MIMO

Mi

Mi – 1

V UL

= V UL

MU – MIMO

 

MU – MIMO

Mi

– VC UL

are given by:

MU – MIMO

Mi

Mi

– VC UL

+ RC UL

MU – MIMO

TX i  ic 

Mi

 RCUL

Saturation occurs when

MU – MIMO

Mi

= TL UL

MU – MIMO

Mi – 1

 V UL

= TL UL – Max .

The following table gives an example: MU – MIMO

Mi

Mobile

MU – MIMO

MU – MIMO

Mi

(%)

TL UL

Mi

(%)

VC UL

MU – MIMO

(%)

RC UL

Mi

V UL

(%)

M1

10

0

10

10

M2

5

5

0

5

M3

20

5

15

15

M4

40

15

25

25

…

…

…

…

…

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

Mi

Downlink: TL DL Sel

Mi

Uplink: TL UL

Sel

Mi

= R DL Sel

Mi

= R UL

Sel

Sel

Mi

Mi

= R Min – DL + R Max – DL Sel

Sel

Mi

Mi

Sel

Mi

= R Min – UL + R Max – UL or TL UL

MU – MIMO

Mi

= RC UL

for MU-MIMO mobiles for cell traffic

load calculation

Output Sel

• •

9.3.8.2

Mi

TL DL

Sel

Mi

Sel

= R DL : Downlink traffic load or the amount of downlink resources allocated to the mobile M i

Sel Mi

TL UL

Sel Mi

Sel

= R UL : Uplink traffic load or the amount of uplink resources allocated to the mobile M i

.

.

User Throughput Calculation User throughputs are calculated for the percentage of resources allocated to each mobile selected by the scheduling for Sel

RRM during the Monte Carlo simulations, M i

.

Input Sel

•

Mi

Sel

R DL : Amount of downlink resources allocated to the mobile M i

as calculated in "Scheduling and Radio

Resource Allocation" on page 551. 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 551. Sel

•

Mi

Sel

CTP P – DL : Downlink peak MAC channel throughput at the mobile M i

as calculated in "Throughput Calculation"

on page 544. Sel

•

Mi

Sel

CTP P – UL : Uplink peak MAC channel throughput at the mobile M i

as calculated in "Throughput Calculation"

on page 544.

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Technical Reference Guide Sel

•

Mi TX i  ic  BLER  B DL  : Downlink block error rate read from the BLER vs. CINR Traffic graph available in the WiMAX   Sel

equipment assigned to the terminal used by the mobile M i •

.

Sel Mi

Mi BLER  B UL  : 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 Sel Mi

Sel

TP Offset : Throughput offset defined in the properties of the service used by the mobile M i

.

.

Calculations Downlink: Sel

Sel

Mi

Sel

Mi

Mi

•

Peak MAC User Throughput: UTP P – DL = R DL  CTP P – DL

•

Mi Mi Mi Effective MAC User Throughput: UTP E – DL = UTP P – DL   1 – BLER  B DL     

Sel

Sel

Sel

Sel

Sel

•

Application User Throughput:

Mi UTP A – DL

Sel

=

Mi UTP E – DL

Mi

Sel f TP – Scaling Mi  ----------------------------- – TP Offset 100

Uplink: Sel

Sel

Mi

Sel

Mi

Mi

•

Peak MAC User Throughput: UTP P – UL = R UL  CTP P – UL

•

Mi Mi Mi Effective MAC User Throughput: UTP E – UL = UTP P – UL   1 – BLER  B UL     

Sel

Sel

Sel

Sel

Sel

•

Application User Throughput:

Mi UTP A – UL

Sel

=

Mi UTP E – UL

Mi

Sel f TP – Scaling Mi  ----------------------------- – TP Offset 100

Output Sel

• • • • • •

9.3.9

Mi

Sel

UTP P – DL : Downlink peak MAC user throughput at the pixel, subscriber, or mobile M i

.

Sel Mi

Sel

UTP E – DL : Downlink effective MAC user throughput at the pixel, subscriber, or mobile M i Sel Mi

Sel

UTP A – DL : Downlink application user throughput at the pixel, subscriber, or mobile M i Sel Mi

Sel

UTP P – UL : Uplink peak MAC user throughput at the pixel, subscriber, or mobile M i Sel Mi

Sel

Sel

UTP A – UL : Uplink application 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 Sel Mi

.

.

.

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 to maximize the C/(I+N). 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 smart antenna models are available in Atoll. These smart antenna models support linear adaptive array systems, such as the one shown in Figure 9.9 on page 559.

558

•

Optimum Beamformer: The Optimum Beamformer smart antenna model performs dynamic beamforming in downlink as explained in "Downlink Beamforming" on page 559, 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 562. Smart antenna results are later on used in coverage prediction calculations ("Traffic and Pilot Interference Signal Levels Calculation (DL)" on page 523 and "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541).

•

Conventional Beamformer: The Conventional Beamformer smart antenna model performs dynamic beamforming in downlink and uplink as explained in "Downlink Beamforming" on page 559 and "Uplink Beamforming" on page 560, respectively. Smart antenna results are later on used in coverage prediction AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks calculations ("Traffic and Pilot Interference Signal Levels Calculation (DL)" on page 523 and "Traffic C/(I+N) and Bearer Calculation (UL)" on page 541).

Figure 9.9Linear Adaptive Antenna Array In the following explanations, we assume:

9.3.9.1

•

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.

Downlink Beamforming

Figure 9.10Downlink 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 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 SA – 1 d  sin  

Where the notation T represents the transpose of a matrix. Therefore, the complex weight at any nth antenna element can be given by: wn = e

© Forsk 2010

2 – j  -------  nd  sin  

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Technical Reference Guide – 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 the notation 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 generates a time-slot scenario for each victim mobile and calculates the downlink C/(I+N) as described in the section "Traffic and Pilot Interference Signal Levels Calculation (DL)" on page 523. However, as it calculates the smart antenna gains for each victim mobile in a cell’s coverage area, it averages the array correlation matrix R  over all the iterations in order to generate an angular distribution of the downlink traffic power density, which is a combination of signal power and angles. The average array correlation matrix is given by: J

R Avg =

 j  pj  Rj j=1

Where R Avg is the average downlink array correlation matrix, J is the number of served mobiles during the simulation,  j is the probability of presence of the mobile j, p j is the EIRP transmitted towards the mobile j, and R j is the array correlation matrix for the mobile j. The probability of presence of the mobile j is the ratio between the downlink resources provided to the mobile j and the total amount of available downlink resources. For example, if a mobile has been granted 10 % of the number of available slots in the downlink subframe, it’s probability of presence is 10 %.

9.3.9.2

Uplink Beamforming

Figure 9.11Uplink Beamforming

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© Forsk 2010

Chapter 9: WiMAX BWA Networks 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 2

RN = Rn + RI = 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. The C/(I+N) in the uplink is then calculated by: P p   E SA CINR UL = ------- = ---------------------------H PN w  RN  w 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 During Monte Carlo simulations, Atoll generates a time-slot scenario for each victim mobile and calculates the uplink C/ (I+N). The average interference and noise on the uplink is stored in the form of correlation matrices as follows: The noise correlation matrix R N for each iteration k includes the effect of the matrix calculated for the previous iteration. The interference power and its direction is stored at the end of each simulation. The result is the angular distribution of the uplink noise rise, 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 noise rise 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

th

correlation matrix of the k 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. The angular distribution of the uplink noise rise is given by: 2

I UL    +  n NR UL    = ---------------------------2 n

© Forsk 2010

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Technical Reference Guide

9.3.9.3

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 output C/(I+N).

Figure 9.12Uplink Adaptive Algorithm 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. ˆ represent the vector of E complex weights for the beamformer. w ˆ is given by: Let w SA ˆ =   R –1  S w  N  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 2

RN = Rn + RI = n  I +

 pj  Sj  Sj

H

j=1 J

 pj  Sj  Sj

2

Where R n =  n  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: ˆ =  2  S H  R–1  S P N   N  And, the total power received from the served user is given by: ˆ = p  2   S H  R –1  S 2 P     N  Where p  is the power received by one element of the smart antenna from the served user. The C/(I+N) in the uplink is then calculated by:

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Chapter 9: WiMAX BWA Networks 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. –1

C UL can be calculated from the above equation by considering the interference and noise to be null, i.e., R N = I . This gives: H

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 During Monte Carlo simulations, Atoll generates a time-slot scenario for each victim mobile and calculates the uplink C/ (I+N). The average interference and noise on the uplink is stored in the form of correlation matrices as follows: –1

The inverse noise correlation matrix R N for each iteration k includes the effect of the matrix calculated for the previous iteration. The interference power and its direction is stored at the end of each simulation. Hence, Atoll is able to calculate an average of the smart antenna interference-cancellation effect. The result is the angular distribution of the uplink noise rise, 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 noise rise can be stored in the Cells table. The average of the inverse noise correlation matrices is calculated as follows: K –1 RN Avg

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

the inverse noise correlation matrix of the

kth

k

is

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. The angular distribution of the uplink noise rise is given by: 2

I UL    +  n NR UL    = ---------------------------2 n

9.4

Automatic Allocation Algorithms The following sections describe the algorithms for: • • • •

9.4.1

"Automatic Neighbour Allocation" on page 563. "Automatic Inter-Technology Neighbour Allocation" on page 566. "Automatic Frequency Planning" on page 568. "Automatic Preamble Index Allocation" on page 571 (fractional frequency planning).

Automatic Neighbour Allocation The intra-technology neighbour allocation 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. Note: •

© Forsk 2010

If no focus zone exists in the .atl document, Atoll takes into account the computation zone.

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Technical Reference Guide 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. 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.

Figure 9.13Determination 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 Neighbour 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). -

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. The coverage areas of TXi(ic) and TXj(jc) must have an overlap ( S TX  ic   S TX  jc  ). 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 TX i  ic 

received preamble signal level ( C Preamble ) and the preamble signal level threshold are calculated from TX i  ic 

TX i  ic 

TX i  ic 

CNR Preamble and T Preamble , respectively, by adding the value of the noise ( n Preamble ) to them. -

TX i  ic 

TX i  ic 

S TX  ic  is the surface area covered by TXi(ic) within C Preamble + HO Start and C Preamble + HO End . i

HO Start is the margin with respect to the best preamble signal level at which the handover starts, and HO End is the margin with respect to the best preamble signal level at which the handover ends. -

S TX  jc  is the coverage area where the candidate cell TXj(jc) is the best server. j

Note:

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Chapter 9: WiMAX BWA Networks

•

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.

•

When the

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.

above conditions are

met, Atoll

calculates the percentage of the coverage area overlap

S TX  ic   S TX  jc  i j -  100 ), and compares this value with the % Min Covered Area. ( -------------------------------------------S TX  ic  i

Figure 9.14Overlapping Zones S TX  ic   S TX  jc  i j -  100  % Min Coverage Area . TXj(jc) is considered a neighbour of TXi(ic) if -------------------------------------------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 importance (%) of neighbours depends on the reason of allocation:

Neighbour 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)

The importance is evaluated using an Importance Function (IF), which takes into account the following factors: • • •

Co-site factor (C): a Boolean, Adjacency factor (A): the percentage of adjacency, Overlapping factor (O): the percentage of overlapping.

The minimum and maximum importance assigned to each of the above factors can be defined.

© Forsk 2010

Factor

Min Importance

Default Value

Max Importance

Default Value

Overlapping factor (O) Adjacency factor (A)

Min(O)

1%

Max(O)

30 %

Min(A)

30 %

Max(A)

60 %

Co-site factor (C)

Min(C)

60 %

Max(C)

100 %

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Technical Reference Guide The Importance Function is evaluated as follows:

Neighbour Cause Co-site

Importance Function

Adjacent

IF with Default Values

No

No

Min(O) + Delta(O)(O)

1 % + 29 %(O)

No

Yes

Min(A)+Delta(A){Max(O)(O)+(100 %-Max(O))(A)}

30 % + 30 %{30 %(O) + 70 %(A)}

Yes

Yes

Min(C)+Delta(C){Max(O)(O)+(100 %-Max(O))(A)}

60 % + 40 %{30 %(O )+ 70 %(A)}

Where Delta(x) = Max(x) - Min(x) Notes: •

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 not be ranked by neighbour cause.

•

The ranking between neighbours from the same category depends on (A) and (O) factors.

•

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 greater than 0 % only if there is some overlapping.

In the results, Atoll lists only the cells for which it finds new neighbours.

9.4.2

Automatic Inter-Technology Neighbour Allocation The inter-technology neighbour allocation 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. Note: •

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. 2. The calculation options: -

-

-

CDMA Carriers: This option is available when an WiMAX network is being co-planned with a UMTS, CDMA, or TD-SCDMA 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: When allocation algorithm is based on distance, 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 = 0.5% so that the maximum variation in D does not to exceed 1%. D is stated in m.

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Figure 9.15Inter-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. This formula is not used when allocation algorithm is based on coverage overlapping. In this case, the actual inter-transmitter distance is considered. -

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 SA SA  SB the % 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 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

d 1 – -----------d max

d is the distance between the reference cell and the neighbour and d max is the maximum inter-site distance. •

© Forsk 2010

For allocation based on coverage overlapping:

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Technical Reference Guide

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: -

Co-site factor (C): a Boolean, 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

Overlapping factor (O)

Min(O)

1%

Max(O)

60 %

Co-site factor (C)

Min(C)

60 %

Max(C)

100 %

The IF evaluates importance as follows:

Co-site

Importance Function

IF with Default Values

No

Min(O) + Delta(O)(O)

1 % + 59 %(O)

Yes

Min(C) + Delta(C)(O)

60 % + 40 %(O)

Where Delta(x) = Max(x) - Min(x) Notes: •

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 not be ranked by neighbour cause.

•

The ranking between neighbours from the same category depends on (A) and (O) factors.

In the results, Atoll displays only the cells for which it finds new neighbours.

9.4.3

Automatic Frequency Planning 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 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 automatic allocation method for frequencies in WiMAX networks, which takes into account interference matrices, neighbour relations, and distance between transmitters. The frequency allocation algorithm 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. Note: •

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If no focus zone exists in the .atl document, Atoll takes into account the computation zone.

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9.4.3.1

Separation Constraint and Relationship Weights The AFP algorithm is based on a cost function which takes into account the following separation constraints: •

Required channel separation  Req -

For co-site cells: 2 channel bandwidths of the TBA cell. For neighbour cells: 1 channel bandwidth of the TBA cell.

The above separation 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 "Take Neighbours into Account" 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 "Take Min Reuse Distance into Account" is selected, Assigned weight  Dis tan ce = 0.2 Notes:

9.4.3.2

•

The sum of the weights assigned to the above relations is 1.

•

These default weights can be modified through the Atoll.ini file. For more information, see the Administrator Manual.

Calculation of Cost Between TBA and Related Cells Atoll calculates the separation constraint violation level between the TBA cell TXi(ic) and its related cell TXj(jc) as follows:

TX i  ic  – TX j  jc  VL Sep

   =    

  TX i  ic  – TX j  jc  –  TXi  ic  – TXj  jc  Req  --------------------------------------------------------------------------------- TX i  ic  – TX j  jc     Req  

if 

0

TX i  ic  – TX j  jc 

Where  Req

2 TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

  Req

Otherwise

is the required separation, and 

TX i  ic  – TX j  jc 

is the actual separation between channels used by

TXi(ic) and TXj(jc) calculated as follows: 

TX i  ic  – TX j  jc 

TX j  jc 

Where F Start TX j  jc 

F Start

TX i  ic 

F Start

TX i  ic 

F Start

TX j  jc 

TX i  ic 

F Start – F Start = -----------------------------------------TX i  ic  W Channel

is the start frequency of the channel used by TXj(jc) calculated as follows:

TX j  jc 

TX j  jc 

TX j  jc 

= F Start – FB + N Channel  W Channel is the start frequency of the channel used by TXi(ic) calculated as follows: TX i  ic 

TX i  ic 

TX i  ic 

= F Start – FB + N Channel  W Channel TX i  ic 

TX j  jc 

Where F Start – FB and F Start – FB are the start frequencies of the frequency bands assigned to the cells TXi(ic) and TXj(jc) respectively. F Start – FB can be the start frequency of a TDD frequency band ( F Start – FB – TDD ), or the downlink start TX i  ic 

TX j  jc 

frequency of an FDD frequency band ( F Start – FB – FDD – DL ). N Channel and N Channel are the channel numbers assigned to cells TXi(ic) and TXj(jc) respectively. 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 

And, W Channel and W Channel are the bandwidths of the channels assigned to cells TXi(ic) and TXj(jc) respectively. The cost of the relation between the TBA cell and its related cell is calculated next: $

© Forsk 2010

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

= VL Sep

TX i  ic  – TX j  jc 

   Neighbour   Neighbour

AT283_TRG_E2

TX i  ic  – TX j  jc 

+  Dis tan ce   Dis tan ce

TX i  ic  – TX j  jc 

 +  IM   IM

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Technical Reference Guide TX i  ic  – TX j  jc 

Where  Neighbour

TX i  ic  – TX j  jc 

is the importance of the relationship between the TBA and its related neighbour cell,  IM

TX i  ic  – TX j  jc 

is the importance of the relationship between the TBA cell and its related interfering cell, and  Dis tan ce

is the

importance of the relationship between the TBA and its related cell with respect to the distance between them. TX i  ic  – TX j  jc 

 Neighbour

is calculated during automatic neighbour allocation by Atoll as explained in "Automatic Neighbour

Allocation" on page 563. For manual neighbour allocation, this value is equal to 1. TX i  ic  – TX j  jc 

 IM

TX i  ic  – TX j  jc 

 IM

•

is calculated during the interference matrices calculation as follows: =

Co-channel interference probability (i.e., for Floor   S TX  ic  i

TX  ic  i C Preamble

TX i  ic  – TX j  jc 

 = 0 ):

TX  ic  i  C TXj  jc  + M  n  ----------------------------------------------------------------Preamble QualityPreamble- ------------------------------TX  ic    10 10 i – 10  Log  10 + 10   T Preamble      

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX  ic  i

•

Adjacent channel interference probability (i.e., for Floor   S TX  ic  i

TX  ic  i C Preamble

TX i  ic  – TX j  jc 

 = 1:

TX  ic  TX  ic  i i  C TXj  jc  + M  +f n  ----------------------------------------------------------------------------------------------------Preamble Quality ACS – FBPreamble- ------------------------------TX  ic    10 10 i – 10  Log  10 + 10   TPreamble      

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX  ic  i

Otherwise, i.e., for other values of Floor   Where S TX  ic  i

TX i  ic 

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

 ,  IM

= 0

is the best server coverage area of the cell TXi(ic), that comprises all the pixels where TX i  ic 

CNR Preamble  T Preamble as calculated in "Service Area Calculation" on page 518. S TX  ic  i

TX i  ic 

is the best server Condition

TX j  jc 

coverage area of the cell TXi(ic) where the given condition is true. C Preamble and C Preamble are the received preamble TX i  ic 

signal levels from the cells TXi(ic) and TXj(jc) respectively, n Preamble the preamble noise for the cell TXi(ic) as calculated in "Preamble Noise Calculation" on page 514, M Quality is the quality margin used for the interference matrices calculation, TX i  ic 

and f ACS – FB is the adjacent channel suppression factor defined for the frequency band of the cell TXi(ic). TX i  ic  – TX j  jc 

In words,  IM

is equivalent to a probability of interference calculated by taking the ratio of the interfered surface

area to the total surface area of a cell. Two interference probabilities are calculated for each interfered-interfering cell pair, i.e., for co-channel and adjacent channel interference. TX i  ic  – TX j  jc 

 Dis tan ce

is calculated by the AFP as follows:

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

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 calculated as follows: D D

TX i  ic  – TX j  jc  TX i  ic  – TX j  jc 

joining them. d

570

= 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)

  1 + x   cos    – cos    – 2  

is weighted according to the orientations of the TBA cell and its related cell with respect to the straight line TX i  ic  – TX j  jc 

is the distance between the two cells considering any offsets with respect to the site locations. AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks TX i  ic  – TX j  jc 

x is set to 15 % so that the maximum variation in D due to the azimuths does not exceed 60 %.  and  are calculated from the azimuths of the two cells as shown in Figure 9.18 on page 575.

Figure 9.16Weighted 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 9.19 on page 575. 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 9.17Importance Based on Distance Relation 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 allocation 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 i  ic 

9.4.3.3

AFP Algorithm The AFP algorithm is an iterative algorithm which: • • • •

9.4.4

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.

Automatic Preamble Index Allocation IEEE 802.16e defines 114 preamble indexes. Each preamble index, from 0 to 113, contains the following information: • • •

© Forsk 2010

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.

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Technical Reference Guide 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 PseudoNoise (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. In a WiMAX 802.16e 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 allocate preamble indexes to cells so as to reduce preamble interference, and allow easy recognition of cells by mobiles. The following describes the automatic allocation method for preamble indexes in a WiMAX 802.16e network, which takes into account the distance between transmitters, the frequency plan of the network (i.e., co- and adjacent channel interference probabilities), and the neighbour relations. The preamble index allocation algorithm 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 status is not set to locked, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone. Note: •

9.4.4.1

If no focus zone exists in the .atl document, Atoll takes into account the computation zone.

Constraint and Relationship Weights The automatic preamble index allocation algorithm 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 = 0.6 2. Same segment number, Assigned weight  Seg = 0.38 3. Same cell permbase, Assigned weight  PB = 0.02 Notes: •

The sum of the weights assigned to the above constraints is 1.

•

These default weights can be modified through the Atoll.ini file. For more information, see the Administrator Manual.

The above separation 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 "Take Neighbours into Account" is selected, Assigned weight  Neighbour = 0.35 Neighbours of a TBA cell are also related to each other through the TBA cell. This relation is also taken into account, Assigned weight  Inter – Neighbour = 0.15

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Chapter 9: WiMAX BWA Networks You can choose to not take into account the inter-neighbour preamble index collision by adding an option in the Atoll.ini file (see the Administrator Manual). If inter-neighbour collision is not taken into account, the weight assigned to the neighbour relation alone is  Neighbour = 0.5 and that of the inter-neighbour collision is of course  Inter – Neighbour = 0 . •

Cells that are listed in the interference matrix of the TBA cell (available with the AFP module only), Assigned weight  IM = 0.3

•

Cells within the cell’s (or the default) minimum reuse distance, if the check box "Take Min Reuse Distance into Account" is selected, Assigned weight  Dis tan ce = 0.2 Notes:

9.4.4.2

•

The sum of the weights assigned to the above relations is 1.

•

These default weights can be modified through the Atoll.ini file. For more information, see the Administrator Manual.

Calculation of Cost Between TBA and Related Cells Atoll calculates the constraint violation level between the TBA cell TXi(ic) and its related cell TXj(jc) as follows: If TX i  ic  and TX j  jc  are co-transmitter cells, and the option Allocate Same Segment to Co-transmitter Cells has been TX i  ic 

selected, and N Seg VL

TX i  ic  – TX j  jc 

TX j  jc 

 N Seg

, then VL

TX i  ic  – TX j  jc 

= rO

TX i  ic  – TX j  jc 

Where r O

TX i  ic  – TX j  jc 

PI

= 1 . Otherwise, Seg

PB

   PI  p Coll +  Seg  p Coll +  PB  p Penalty 

is the total channel overlap ratio between the TXi(ic) and TXj(jc) as calculated in "Co- and Adjacent

Channel Overlaps Calculation" on page 508,  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 i  ic  TX i  ic 

= PI  PI

TX j  jc 

TX j  jc 

.

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   0 Seg Seg Same Segment to Co-transmitter Cells has been selected, p Coll is given by p Coll =    1

Otherwise,

PB

p Penalty

Seg p Coll

  1 =    0

TX i  ic 

if N Seg

TX i  ic 

if N Seg

TX i  ic 

if N Seg

TX i  ic 

if N Seg

TX j  jc 

= N Seg

TX j  jc 

.

 N Seg

TX j  jc 

= N Seg

TX j  jc 

.

 N Seg

  1 if PB TXi  ic   PB TX j  jc  AND Site TXi  ic  = Site TX j  jc   PB is the cell permbase penalty given by p Penalty =  TX i  ic  TX j  jc  TX i  ic  TX j  jc  if  PB AND Site  Site 0.001 if PB  0 Otherwise  PB

the cell permbase allocation strategy is set to "Same per Site", and by p Penalty = 0 if the cell permbase allocation strategy is set to "Free". The cell permbase penalty models the cell permbase constraint. Next, Atoll calculates the importance of the relation between the TBA cell and its related cell. TX i  ic  – TX j  jc 

 Total

TX  ic  – TX j  jc 

i =  Neighbour   Neighbour

 IM  TX i  ic  – TX j  jc 

Where  Neighbour

TX i  ic  – TX j  jc   IM

+  Inter – Neighbour   Inter – Neighbour + TX i  ic  – TX j  jc 

+  Dis tan ce   Dis tan ce

is the importance of the relationship between the TBA cell and its related neighbour cell, TX i  ic  – TX j  jc 

 Inter – Neighbour is the importance of the relationship between two neighbours of the TBA cell,  IM

is the

importance of the relationship between the TBA cell and its related interfering cell (available with the AFP module only), TX i  ic  – TX j  jc 

and  Dis tan ce

is the importance of the relationship between the TBA and its related cell with respect to the distance

between them.

© Forsk 2010

AT283_TRG_E2

573

Technical Reference Guide TX i  ic  – TX j  jc 

 Neighbour

is calculated during automatic neighbour allocation by Atoll as explained in "Automatic Neighbour

Allocation" on page 563. For manual neighbour allocation, this value is equal to 1.  Inter – Neighbour is calculated from the neighbour relationship importance values calculated during automatic neighbour allocation. If two neighbours of the TBA cell have the same preamble index assigned, the importance of the inter-neighbour preamble index collision is the average of their neighbour importance values with the TBA 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   ----------------------------------------------------------------------------------------- 2  All Neighbour Pairs  Max

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. TX i  ic  – TX j  jc 

 IM

TX i  ic  – TX j  jc 

 IM

•

is calculated during the interference matrices calculation as follows: =

Co-channel interference probability (i.e., for Floor   S TX  ic  i

TX i  ic  – TX j  jc 

 = 0 ):

TX i  ic   C TXj  jc  + M  n Preamble  ----------------------------------------------------------------Preamble Quality -------------------------------- TX i  ic   10 10 C Preamble – 10  Log  10 + 10   T Preamble       TX i  ic 

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX  ic  i

•

Adjacent channel interference probability (i.e., for Floor   S TX  ic  i

TX i  ic  – TX j  jc 

 = 1:

TX i  ic  TX i  ic   C TXj  jc  + M  n Preamble  ----------------------------------------------------------------------------------------------------Preamble Quality + f ACS – FB -------------------------------- TX i  ic   10 10 C Preamble – 10  Log  10 + 10   TPreamble       TX i  ic 

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX  ic  i

Otherwise, i.e., for other values of Floor   Where S TX  ic  i

TX i  ic 

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

 ,  IM

= 0

is the best server coverage area of the cell TXi(ic), that comprises all the pixels where TX i  ic 

CNR Preamble  T Preamble as calculated in "Service Area Calculation" on page 518. S TX  ic  i

TX i  ic 

is the best server Condition

TX j  jc 

coverage area of the cell TXi(ic) where the given condition is true. C Preamble and C Preamble are the received preamble TX i  ic 

signal levels from the cells TXi(ic) and TXj(jc) respectively, n Preamble the preamble noise for the cell TXi(ic) as calculated in "Preamble Noise Calculation" on page 514, M Quality is the quality margin used for the interference matrices calculation, TX i  ic 

and f ACS – FB is the adjacent channel suppression factor defined for the frequency band of the cell TXi(ic). TX i  ic  – TX j  jc 

In words,  IM

is equivalent to a probability of interference calculated by taking the ratio of the interfered surface

area to the total surface area of a cell. Two interference probabilities are calculated for each interfered-interfering cell pair, i.e., for co-channel and adjacent channel interference. TX i  ic  – TX j  jc 

574

 Dis tan ce

is calculated by the preamble index allocation algorithm as follows:

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

TX i  ic  – TX j  jc 

1

Otherwise

AT283_TRG_E2

© Forsk 2010

Chapter 9: WiMAX BWA Networks Where D Reuse is the minimum reuse distance, either defined for each TBA cell individually or set for all the TBA cells in the automatic allocation dialogue, and D cell TXj(jc) calculated as follows: D D

TX i  ic  – TX j  jc 

= d

TX i  ic  – TX j  jc 

joining them. 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

  1 + x   cos    – cos    – 2  

is weighted according to the orientations of the TBA and its related cell with respect to the straight line TX i  ic  – TX j  jc 

is the distance between the two cells considering any offsets with respect to the site locations. TX i  ic  – TX j  jc 

x is set to 15 % so that the maximum variation in D due to the azimuths does not exceed 60 %.  and  are calculated from the azimuths of the two cells as shown in Figure 9.18 on page 575.

Figure 9.18Weighted 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 9.19 on page 575. 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 9.19Importance Based on Distance Relation 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 

  Total

The quality reduction factor is a measure of the cost of an individual relation. The total cost of the current preamble index allocation 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 allocation 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 

9.4.4.3

Automatic Allocation Algorithm The automatic preamble index allocation algorithm is an iterative algorithm which: • •

© Forsk 2010

Calculates the cost (as described above) of the current preamble index allocation, Allocates new preamble indexes to cells in order to reduce the costs, and calculates the cost again,

AT283_TRG_E2

575

Technical Reference Guide •

576

Memorises the different allocation plans in order to determine the best allocation, i.e., which provides the lowest total cost.

AT283_TRG_E2

© Forsk 2010

Chapter 10 LTE Networks

Chapter 10: LTE Networks

10

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 and MIMO, 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. Important: •

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 74.

•

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: -

-

•

All the calculation algorithms in this section are described for two types of receivers: -

•

10.1

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).

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.

Definitions and Formulas The tables in the following subsections list the input and output parameters, and formulas used in simulations and other computations.

10.1.1

Input This table lists the input to computations, 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

Global parameter

None

Default cyclic prefix duration

N SD – PDCCH

Global parameter

SD

Number of PDCCH symbol durations per subframe

© Forsk 2010

AT283_TRG_E2

579

Technical Reference Guide N FB – PUCCH

Global parameter

RB

Average number of PUCCH frequency blocks per frame

 TDD

Global parameter

None

Switching point periodicity for TDD frames

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

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

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

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

N Channel

Cell parameter

None

Cell’s channel number

ID 

Cell parameter

None

Cell’s physical ID

ID SSS

Cell parameter

None

Cell’s SSS ID (one of 168 pseudorandom sequences)

ID PSS

Cell parameter

None

Cell’s PSS ID (one of 3 orthogonal sequences)

P Max

Cell parameter

dBm

Maximum cell transmission power

N Channel

nf

G L

580

TX

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks

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

TL DL

Cell parameter

%

Downlink traffic load

r DL – ICIC

Cell parameter

%

Downlink ICIC ratio

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

NR ICIC – UL

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

T AMS

Cell parameter

dB

Adaptive MIMO switch threshold

T MU – MIMO

Cell parameter

dB

Multi-user MIMO threshold

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

D Reuse

Cell parameter

m

Channel and physical cell ID reuse distance

G MU – MIMO

Cell parameter

None

Uplink MU-MIMO gain

 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

Proportional Fair scheduler parameter

None

Downlink multi-user diversity gain (MUG)

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

Cell LTE equipment parameter

None

Maximum uplink SU-MIMO gain

G Div

Cell LTE equipment parameter

dB

Uplink diversity gain

p

Service parameter

None

Service priority

B DL – Highest

Service parameter

None

Highest bearer used by a service in the downlink

NR DL NR UL

TX i  ic 

G MUG – DL TX i  ic 

G MUG – UL Max

CINR MUG Max

G SU – MIMO UL

© Forsk 2010

AT283_TRG_E2

581

Technical Reference Guide B UL – Highest

Service parameter

None

Highest bearer used by a service in the uplink

f Act

UL

Service parameter

%

Uplink activity factor for voice services

f Act

DL

Service parameter

%

Downlink activity factor for voice services

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

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

Terminal LTE equipment parameter

None

Maximum downlink SU-MIMO gain

Terminal LTE equipment parameter

dB

Downlink diversity gain

G Div

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

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

TP Average

Max

G SU – MIMO DL

G Div

a.

Any interfering cell whose signal to thermal noise ratio is less than CNR Min will be discarded.

10.1.2

582

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 SCa – FB

W FB ----------F

None

Number of subcarriers per frequency block

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks TX i  ic 

TX i  ic 

N Sym – DL

N FB    8   16    24 

TX i  ic 

N Res  SRB

TX i  ic 

TX i  ic 

 N Sym  SRB  N SF – DL

TX i  ic 

if  N Ant – TX = 2 

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 one frame

None

Number of symbols for the PSS and the SSS

None

Number of symbols for the PBCH

None

Number of symbols for the PDCCH

None

Number of symbols for the PDSCH

TX i  ic 

TX i  ic 

TX i  ic 

 N Res  SRB

TX i  ic 

if  N Ant – TX = 1 

TX i  ic 

if

TX i  ic   N Ant – TX

= 2

if

TX i  ic   N Ant – TX

= 4 or 8 

TX i  ic 

TX i  ic 

N SF – DL  N FB

N Sym – DLRS

Number of symbols reserved for downlink reference signals in one scheduler resource block

if  N Ant – TX = 4 or 8 

   8   8    6 

TX i  ic 

None

TX i  ic 

TX i  ic 

N DLRS  SRB

Total number of symbols in downlink

if  N Ant – TX = 1 

N SF – DL  N FB

N Sym – Res

None

 N DLRS  SRB

N Sym – PSS + N Sym – SSS = 288 N Sym – SS

Where N Sym – PSS = 2  N FB – SS PBCH  N SCa – FB = 144 N Sym – SSS = 2  N FB – SS PBCH  N SCa – FB = 144 TX  ic 

TX i  ic 

N Sym – PBCH

i  N Res  SRB Extended CP:  4  N SCa – FB – -------------------------  N FB – SS PBCH 2  

Normal CP:  4  N SCa – FB – 2 

TX i  ic  N Ant – TX 

 N FB – SS PBCH

If N SD – PDCCH = 0 : 0 TX i  ic 

If  N SD – PDCCH = 1  AND  N Ant – TX = 4 or 8  : TX i  ic 

TX i  ic 

N Sym – PDCCH

 N SD – PDCCH  N SCa – FB – N Ant – TX  TX i  ic  ------------------------------------------------------------------------------------------------  N Sym – DL N Sym  SRB TX i  ic 

 N SD – PDCCH  N SCa – FB – 2  N Ant – TX  TX i  ic  Otherwise: -----------------------------------------------------------------------------------------------------------  N Sym – DL N Sym  SRB TX i  ic 

N Sym – PDSCH

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

N Sym – DL – N Sym – Res – N Sym – SS – N Sym – PBCH – N Sym – PDCCH TX i  ic 

 PMax  TX i  ic    ------------------10 10  Log  10  N SD  Slot  N Slot  SF  N SF – DL –     TX  ic  i

TX i  ic 

EPRE DLRS

TX i  ic 

+ N Sym – PDCCH  10

TX i  ic 

EPRE SS

TX i  ic 

EPRE PBCH TX i  ic 

EPRE PDCCH TX i  ic 

EPRE PDSCH

© Forsk 2010

TX  ic  i

EPRE SS EPRE PBCH  -------------------------------------------------------------------------- TX i  ic  10 10 dBm/Sym + N Sym – PBCH  10 10  L og N Sym – DLRS+ N Sym – SS 10   EPRE PDCCH ----------------------------------------10

Energy per resource element for 1 modulation symbol (dBm/Sym) of the downlink reference signals

TX i  ic 

+ N Sym – PDSCH  10

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

EPRE PDSCH  -----------------------------------------  10

EPRE DLRS + EPRE SS

EPRE DLRS + EPRE PBCH TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

EPRE DLRS + EPRE PDCCH

EPRE DLRS + EPRE PDSCH

AT283_TRG_E2

   dBm/Sym

Energy per resource element for 1 modulation symbol (dBm/Sym) of the SS

dBm/Sym

Energy per resource element for 1 modulation symbol (dBm/Sym) of the PBCH

dBm/Sym

Energy per resource element for 1 modulation symbol (dBm/Sym) of the PDCCH

dBm/Sym

Energy per resource element for 1 modulation symbol (dBm/Sym) of the PDSCH

583

Technical Reference Guide TX i  ic 

TX i  ic 

TX i  ic 

P SS

TX i  ic 

P PBCH TX i  ic 

P PDCCH

TX i  ic  P PDSCH

10.1.3

TX i  ic 

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    TX i  ic  N Sym–PDCCH - EPRE PDCCH + 10  Log  ----------------------------------------------------------TX i  ic     N SD – PDCCH  N SF – DL

dBm

Average transmission power of the PDCCH

dBm

Average transmission power of the PDSCH

EPRE DLRS + 10  Log  2  N FB

P DLRS

TX i  ic 

EPRE SS

TX i  ic 

TX i  ic  EPRE PDSCH

TX i  ic    N Sym–PDSCH  - + 10  Log ------------------------------------------------------------------------------------------------------------------TX i  ic      N SD  SlotN Slot  SF–N SD – PDCCH   N SF – DL

Co- and Adjacent Channel Overlaps Calculation

Name TX i  ic 

F Start

TX i  ic 

F End

TX i  ic  – TX j  jc 

W CCO

Value TX i  ic 

TX i  ic 

L

TX i  ic 

TX i  ic 

TX j  jc 

TX i  ic  – TX j  jc  H

TX i  ic  – TX j  jc 

First

TX j  jc 

TX i  ic 

 – Max  FStart  F Start 

Unit

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

Total overlap ratio

TX i  ic  – TX j  jc 

W CCO --------------------------------------TX i  ic  W Channel TX j  jc 

TX i  ic 

TX j  jc 

TX i  ic 

TX i  ic 

Min  F End  F Start  – Max  F Start  F Start – W Channel  TX i  ic  – TX j  jc 

W ACO L --------------------------------------TX i  ic  W Channel TX j  jc 

TX i  ic 

Min  F End  F End

TX i  ic 

TX j  jc 

TX i  ic 

+ W Channel  – Max  F Start  F End



TX i  ic  – TX j  jc 

W ACO H --------------------------------------TX i  ic  W Channel

TX i  ic  – TX j  jc  r ACO H

r ACO

TX i  ic 

TX i  ic 

Min  FEnd  F End

TX i  ic  – TX j  jc  r ACO L

W ACO

First

F Start – Band + W Channel   N Channel – N Channel + 1 

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

TX i  ic 

F Start – Band + W Channel   N Channel – N Channel 

r CCO

W ACO



TX i  ic  – TX j  jc 

r ACO

L

TX i  ic  – TX j  jc 

+ r ACO

H

TX i  ic 

– f ACS   --------------------- TX i  ic  TX j  jc   TXi  ic  – TXj  jc  TX i  ic  – TX j  jc  10 + r ACO  10  r CCO  if W Channel  W Channel     TX i  ic  – TX j  jc 

rO

TX i  ic 

– f ACS   TX i  ic  --------------------- W Channel  TXi  ic  – TXj  jc  TX i  ic  – TX j  jc  10 + r ACO  10  r CCO   ----------------------  W TXj  jc  Channel   TX i  ic 

TX j  jc 

if W Channel  W Channel

584

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks

10.1.4

Signal Level and Signal Quality Calculations

10.1.4.1

Signal Level Calculation (DL)

Name TX i  ic  C DLRS

Value TX i  ic 

EIRP DLRS – L Path – M Shadowing – Model – L Indoor + G –L

Mi

–

Mi L Ant

–

Mi L Body

TX i  ic 

TX i  ic 

C SS

P DLRS + G TX i  ic 

EIRP SS –L

Mi

TX i  ic 

P SS

Mi

Mi

TX i  ic 

–

Mi L Ant

–

Mi L Body

TX i  ic 

Mi

Mi

TX i  ic 

P PDSCH + G TX i  ic 

EPRE DLRS + G – L Indoor + G TX i  ic 

EPRE SS

Mi

–L

+G

– L Indoor + G

Mi

TX i

–L

TX i  ic 

– L Indoor + G

Mi

TX i  ic 

– L Indoor + G

Mi

TX i  ic 

EPRE PDSCH + G – L Indoor + G

Mi

Mi

Mi

TX i

–L

Mi

–L

dBm

SS EIRP

dBm

Received PBCH signal level

dBm

PBCH EIRP

dBm

Received PDCCH signal level

dBm

PDCCH EIRP

dBm

Received PDSCH signal level

dBm

PDSCH EIRP

dBm/Sym

Received downlink reference signal energy per resource element

dBm/Sym

Received SS energy per resource element

dBm/Sym

Received PBCH energy per resource element

dBm/Sym

Received PDCCH energy per resource element

dBm/Sym

Received PDSCH energy per resource element

dB

Path loss

dB

Total losses

dB

Cyclic prefix factor, i.e., the ratio of the useful symbol energy to the total symbol energy

Mi

TX i

–

–

TX i

TX i

–

–

Mi

–L

TX i

Mi L Body

+ f CP

Mi

– L Body + f CP

– L Path – M Shadowing – Model –

TX i

Mi L Ant

–L

– L Path – M Shadowing – Model

Mi L Ant

–L

TX i

Mi L Body

+ f CP

– L Path – M Shadowing – Model –

TX i

Mi L Body

+ f CP

– L Path – M Shadowing – Model

Mi

Mi

– L Ant – L Body + f CP L Model + L Ant

L Path + L +L

Mi

TX i

–G

Mi

+ L Indoor + M Shadowing – Model – G Mi

TX i

Mi

+ L Ant + L Body

10  Log  7  7.5  If

D CP = Normal

10  Log  6  7.5  If

D CP = Extended

0

© Forsk 2010

TX i

TX i

L Path

f CP

TX i

– L Path – M Shadowing – Model

Mi L Ant

–L

TX i

–L

–

TX i

Mi L Ant

–L

Mi

TX i

–L

–L

Mi

TX i

EPRE PDCCH + G

L Total

Received SS signal level

Mi

Mi

TX i  ic 

TX i  ic 

dBm

– L Ant – L Body + f CP

EPRE PBCH + G

E PDSCH

–L

TX i  ic 

TX i  ic  E PBCH

E PDCCH

TX i

EIRP PDSCH – L Path – M Shadowing – Model – L Indoor + G –L

Downlink reference signals EIRP

+ f CP TX i  ic 

TX i  ic 

E SS

TX i

P PDCCH + G

EIRP PDSCH TX i  ic  E DLRS

–L

TX i  ic 

TX i  ic 

TX i  ic 

TX i

EIRP PDCCH – L Path – M Shadowing – Model – L Indoor + G –L

dBm Mi

Mi

P PBCH + G

Mi

Received downlink reference signal level

– L Ant – L Body + f CP

EIRP PDCCH

C PDSCH

+G

TX i  ic 

TX i  ic 

TX i  ic 

TX i

EIRP PBCH – L Path – M Shadowing – Model – L Indoor + G

EIRP PBCH

C PDCCH

–L

Mi

TX i  ic 

–L

dBm

Mi

– L Ant – L Body + f CP

EIRP SS

TX i  ic  C PBCH

TX i

– L Path – M Shadowing – Model – L Indoor + G

Mi

Description

+ f CP TX i  ic 

EIRP DLRS

Unit

If

TX i  ic  is an interferer

AT283_TRG_E2

585

Technical Reference Guide

10.1.4.2

Noise Calculation (DL)

Name

Value

Unit

Description

TX i  ic 

n 0 + 10  Log  F 

dBm

Thermal noise for one resource element

dBm

Downlink noise for one resource element

dBm

Downlink reference signals thermal noise

dBm

Downlink reference signals noise

dBm

SS thermal noise

dBm

SS noise

dBm

PBCH thermal noise

dBm

PBCH noise

dBm

PDCCH thermal noise

dBm

PDCCH noise

dBm

PDSCH thermal noise

dBm

PDSCH noise

Unit

Description

dBm/Sym

Interfering energy per resource element (dBm/Sym) received over downlink reference signals

n 0 – Sym TX i  ic 

TX i  ic 

n Sym

n 0 – Sym + nf

Mi

Without static downlink ICIC using FFR: TX i  ic 

n 0 + 10  Log  N FB

TX i  ic  n 0 – DLRS

 W FB  1000 

With static downlink ICIC using FFR: TX i  ic 

n 0 + 10  Log  N FB  TX i  ic 

1  W FB  1000  --- 3

TX i  ic 

n DLRS

n 0 – DLRS + nf

TX i  ic 

Mi

n 0 + 10  Log  N FB – SS PBCH  W FB  1000 

n 0 – SS

TX i  ic 

TX i  ic 

n SS

n 0 – SS + nf

TX i  ic 

Mi

n 0 + 10  Log  N FB – SS PBCH  W FB  1000 

n 0 – PBCH TX i  ic 

TX i  ic 

n PBCH

n 0 – PBCH + nf

Mi

Without static downlink ICIC using FFR: TX i  ic 

n 0 + 10  Log  N FB

TX i  ic 

n 0 – PDCCH

 W FB  1000 

With static downlink ICIC using FFR: n 0 + 10 

TX i  ic  Log  N FB 

TX i  ic 

1  W FB  1000  --- 3

TX i  ic 

n PDCCH

n 0 – PDCCH + nf

Mi

Without static downlink ICIC using FFR: TX i  ic 

n 0 + 10  Log  N FB

TX i  ic  n 0 – PDSCH

With static downlink ICIC using FFR: n 0 + 10 

TX i  ic  Log  N FB 

TX i  ic 

1  W FB  1000  --- 3

TX i  ic 

n PDSCH

10.1.4.3

n 0 – PDSCH + nf

Value TXj  jc 

TX j  jc 

TX j  jc 

TX  jc  j

E PDCCH  TX j  jc  TX  jc  ---------------------- N j TX  ic  – TX j  jc  TX j  jc  N Sym – PDSCH 10 Sym – PDCCH  -  + fO i + 10 + f MIMO  ---------------------------------- ----------------------------------TX j  jc  TX j  jc  N Sym – DL N Sym – DL   TX  jc 

j E PBCH  ESSj ------------------- ------------------TX j  jc  10 10  N Sym – SS + 10  N Sym – PBCH  10 10  Log  -----------------------------------------------------------------------------------------------------------------------TX j  jc   N Sym – SS + N Sym – PBCH  

 SS PBCH

TX j  jc 

 1 –

TX i  ic  – TX j  jc  f DC – SCa – Shift 

TX i  ic  – TX j  jc 

+ fO

586

TX i  ic  – TX j  jc 

E PDSCH + f ICIC – DL  E DLRS TX  jc  - N j --------------------------------------------------------------------TX j  jc   ------------------10 10 Sym – DLRS 10  Log  10 +  TL DL  ------------------------------10 TX j  jc   N Sym – DL 

TX  jc 

TX j  jc 

Mi

Interference Calculation (DL)

Name

 DLRS

 W FB  1000 

+ 10

E PDSCH ----------------------10

TX i  ic  – TX j  jc 



TX j  jc  

 f DC – SCa – Shift  TL DL

Interfering energy per resource dBm/Sym element (dBm/Sym) received over the SS and the PBCH

  

TX j  jc 

+ f MIMO

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks TX  jc  j

TX j  jc 

 PDSCH PDCCH

TX  jc  j

TX  ic  – TX  jc  i j

E PDSCH + f ICIC – DL  E DLRS TX  jc  - N j -------------------------------------------------------------------TX j  jc   ------------------10 10 Sym – DLRS 10  Log  10 +  TL DL  ------------------------------10 TX j  jc   N Sym – DL  TX j  jc 

E PDCCH  TX j  jc  TX  jc  ----------------------- N j N Sym – PDSCH TX  ic  – TX j  jc  TX j  jc  10 Sym – PDCCH  -----------------------------------  + fO i + + f MIMO  ----------------------------------10  TX j  jc  TX j  jc   N Sym – DL N Sym – DL 

Interfering energy per resource dBm/Sym element (dBm/Sym) received over the PDSCH and the PDCCH

TX  jc  j

 EDLRS  ------------------10 10  Log  10 2   TX j  jc   RSSI

Interfering energy per frequency block (dBm/RB) received over 1 frequency  block during an OFDM symbol TX j  jc  TX j  jc  TX j  jc   N Sym – PDSCH  TL DL + 10  N Sym – PDCCH 10  -  10  carrying reference signals + ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------TX j  jc  TX j  jc   N Sym – PDSCH + N Sym – PDSCH   dBm/RB TX i  ic  – TX j  jc  TX j  jc  + fO + f MIMO TX  jc  j

TX  ic  – TX  jc  i j

TX i  ic 

TX  ic 

TX  jc 

TX i  ic 

TX i  ic 

TX i  ic 

First – TX i  ic 

F Start – Band + W Channel   N Channel – N Channel 

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

10  Log  r O

fO

TX i  ic  – TX j  jc 

TX j  jc 

1 + --- 2



TX i  ic  – TX j  jc 

10  Log  p Collision

f ICIC – DL



TX j  jc 

10  Log  N Ant – TX 

f MIMO

10.1.4.4

E PDCCH ----------------------10

i j  F Centre – F Centre  Min  1 ------------------------------------------------------  N FB – SS PBCH  W FB 

TX i  ic  – TX j  jc 

f DC – SCa – Shift

F Centre

TX  jc  j

E PDSCH + f ICIC – DL --------------------------------------------------------------------10

None

DC subcarrier shift factor

MHz

Centre frequency of the channel used by TXi(ic)

dB

Interference reduction factor due to channel overlap

dB

Interference reduction factor due to static downlink ICIC using fractional frequency reuse

dB

Interference increment due to more than one transmission antenna port

Unit

Description

dB

Downlink reference signals C/N

dB

SS C/N

dB

PBCH C/N

dB

PDCCH C/N

dB

PDSCH C/N

Unit

Description

dB

Downlink reference signals C/(I+N)

C/N Calculation (DL)

Name

Value

TX i  ic 

TX i  ic 

CNR DLRS

TX i  ic 

E DLRS – n Sym

TX i  ic 

TX i  ic 

CNR SS

E SS

TX i  ic 

CNR PBCH

TX i  ic 

– n Sym

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

E PBCH – n Sym

TX i  ic 

CNR PDCCH

E PDCCH – n Sym E PDSCH – n Sym

With Transmit Diversity: TX i  ic  CNR PDSCH

TX i  ic 

CNR PDSCH

With AMS if

TX i  ic  CNR DLRS

TX i  ic  CNR PDSCH

10.1.4.5

TX i  ic 

=



TX i  ic  T AMS

or

TX i  ic  CNR PDSCH

TX i  ic  CINR DLRS DL



TX i  ic  T AMS

:

DL

+ G Div + G Div

Value TX  jc  j

© Forsk 2010

DL

C/(I+N) Calculation (DL)

Name TX i  ic  CINR DLRS

DL

= CNR PDSCH + G Div + G Div

TX i  ic  E DLRS

TX  ic  i

n Sym    DLRS     ------------------ -----------------  Inter – Tech 10  10  –  10  Log   10  + 10  + NR DL        All TX  jc        j



AT283_TRG_E2

587

Technical Reference Guide TX  jc  j

TX  ic  i

CINR SS

n Sym    SS PBCH    - -------------------- TX i  ic    ------------------------- 10 10 Inter – Tech E SS –  10  Log   10  + 10  + NR DL        All TX  jc        j

TX i  ic  CINR PBCH

TX i  ic  E PBCH

TX i  ic 



TX  jc  j

TX i  ic 

SS C/(I+N)

dB

PBCH C/(I+N)

TX  ic  i

n Sym    SS PBCH    - --------------------  -------------------------  10 10 Inter – Tech –  10  Log   10  + 10  + NR DL           All TX j  jc    



TX j  jc 

CINR PDCCH

dB

TX i  ic 

n Sym    PDSCH PDCCH    - ------------------TX i  ic   -----------------------------------------  10 10  Inter – Tech dB E PDCCH –  10  Log   10  + 10  + NR DL        All TX  jc        j



TX j  jc 

TX i  ic  E PDSCH

TX i  ic 

CINR PDSCH

PDCCH C/(I+N)

TX i  ic 

n Sym   PDSCH PDCCH    - --------------------  -----------------------------------------  10 10 Inter – Tech –  10  Log   10  + 10  + NR DL           All TX j  jc     With Transmit Diversity:



TX i  ic 

TX i  ic 

DL

DL

dB

PDSCH C/(I+N)

dB

Reference signal received quality (RSRQ)

CINR PDSCH = CINR PDSCH + G Div + G Div With AMS if

TX i  ic 

TX i  ic 

CNR DLRS  T AMS TX i  ic 

TX i  ic 

TX i  ic 

or CINR DLRS  T AMS :

TX i  ic 

DL

DL

CINR PDSCH = CINR PDSCH + G Div + G Div RSRQ

TX i  ic 

TX i  ic 

10  Log  N FB

TX i  ic 

 + E DLRS – RSSI

TX i  ic 

TX  ic 

RSSI

TX i  ic 

TX  ic 

i i E PDSCH E PDCCH   TXi  ic  -------------------------------------------   E DLRS TX i  ic  TX i  ic  TX i  ic  10 10 ------------------ N  TL + 10  N TX  ic  10   10 Sym – PDSCH DL Sym – PDCCH -  10  N Anti – TX 10  Log   10  2 + -----------------------------------------------------------------------------------------------------------------------------------------------------------------------TX i  ic  TX i  ic    N Sym – PDSCH + N Sym – PDCCH     TX  jc  j

TX  ic  i

n Sym   RSSI   -------------------TX i  ic   ----------------- 10  10 Inter – Tech +  12  + NR DL + 10  Log  N FB   10  + 10    All TXj  jc    



dBm TX  jc  j

Received signal strength indicator (RSSI)

TX  ic  i

n Sym    DLRS   --------------------  ----------------- 10  10 10  Log   10  + 10      All TX  jc      j



I +

TX i  ic  N DLRS

Inter – Tech

+ NR DL

TX i  ic 

+ 10  Log  2  N FB

TX  jc  j

dBm

Downlink reference signals total noise (I+N)

dBm

SS and PBCH total noise (I+N)

dBm

PDSCH and PDCCH total noise (I+N)



TX  ic  i

n Sym    SS PBCH  - --------------------  ------------------------- 10 10 10  Log   10  + 10        All TX j  jc   



I +

TX i  ic  N  SS PBCH

Inter – Tech

+ NR DL

+ 10  Log  N SCa – FB  N FB – SS PBCH 

TX  jc  j

TX  ic  i

n Sym     PDSCH PDCCH - --------------------   -----------------------------------------10 10 10  Log  10 + 10         All TX j  jc    



I +

588

TX i  ic  N  PDSCH PDCCH

TX i  ic   N TX i  ic   Inter – Tech Sym – PDSCH + N Sym – PDCCH   + NR DL + 10  Log -----------------------------------------------------------------------------TX i  ic     N SD  Slot  N Slot  SF  N SF – DL

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks

10.1.4.6

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

EIRP PUSCH PUCCH – L Path – M Shadowing – Model – L Indoor + G –L

TX i

–

Mi L Ant

–

Mi L Body

Mi

With P

Mi

Mi

+G

Mi

–L

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

dB

Interference reduction factor due to static uplink ICIC using fractional frequency reuse

Unit

Description

dB

Uplink noise rise for any mobile Mi covered by the non-ICIC zone in the interfered cell TXi(ic)

Mi

Mi

Mi

dBm

TX i

= P Allowed without power control adjustment and

P

Description

+ f CP P

EIRP PUSCH PUCCH



Unit

Mi

= P Eff after power control adjustment

10  Log  7  7.5  If D CP = Normal 10  Log  6  7.5  If D CP = Extended

f CP

0

10.1.4.7

If M i is an interferer

Noise Calculation (UL)

Name

Value

TX i  ic 

TX i  ic 

n 0 + 10  Log  N FB

n 0 – PUSCH PUCCH TX i  ic 

TX i  ic 

n PUSCH PUCCH

10.1.4.8

n 0 – PUSCH PUCCH + nf

Mj

Value TX i  ic  – TX j  jc 

Mj

C PUSCH PUCCH + f O

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

Mj

TX i  ic  – TX j  jc 

Mj

+ f TL – UL + f ICIC – UL

10  Log  r O

fO



Mj

10  Log  TL UL 

f TL – UL TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

10  Log  p Collision

f ICIC – UL

10.1.4.9

TX i  ic 

Interference Calculation (UL)

Name I PUSCH PUCCH

 W FB  1000 



Noise Rise Calculation (UL)

Name

Value M   j  I PUSCH  TX  ic  i  PUCCH   non-ICIC M  n PUSCH PUCCH  i   ---------------------------------------------------------------------------------------------------------------------  10 10  10  Log   10  + 10     All Mj        All TX  jc    j



TX i  ic 

NR UL

Inter – Tech

+ NR UL

© Forsk 2010

TX i  ic 

– n PUSCH PUCCH

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589

Technical Reference Guide M   j  IPUSCH  TX i  ic   PUCCH   ICIC M  n PUSCH PUCCH  i   -----------------------------------------------------------------------------------------------------------  10 10  10  Log  10 + 10       All Mj        All TX  jc    j



TX i  ic 

NR ICIC – UL

Inter – Tech

+ NR UL

dB

Uplink noise rise for any mobile Mi covered by the ICIC zone in 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)

dBm

Effective transmission power of a user equipment after power control adjustment

TX i  ic 

– n PUSCH PUCCH

For any mobile Mi covered by the non-ICIC zone in the interfered cell TX i  ic 

I +

TX i  ic  N  PUSCH PUCCH

TXi(ic): NR UL

TX i  ic 

+ n PUSCH PUCCH

For any mobile Mi covered by the ICIC zone in the interfered cell TX i  ic 

TX i  ic 

TXi(ic): NR ICIC – UL + n PUSCH PUCCH

10.1.4.10

C/N Calculation (UL)

Name

Value TX i  ic 

Mi

C PUSCH PUCCH – n PUSCH PUCCH With Receive Diversity: Mi CNR PUSCH PUCCH

Mi CNR PUSCH PUCCH

With AMS if

TX i  ic  CNR DLRS

Mi CNR PUSCH PUCCH

10.1.4.11

Mi

UL

UL

= CNR PUSCH PUCCH + G Div + G Div

=



TX i  ic  T AMS

or

TX i  ic  CINR DLRS

Mi CNR PUSCH PUCCH



UL

TX i  ic  T AMS

:

UL

+ G Div + G Div

C/(I+N) Calculation (UL)

Name

Value For any mobile Mi covered by the non-ICIC zone in the interfered cell TX i  ic 

Mi

TXi(ic): CNR PUSCH PUCCH – NR UL

For any mobile Mi covered by the ICIC zone in the interfered cell TX i  ic 

Mi

TXi(ic): CNR PUSCH PUCCH – NR ICIC – UL

Mi CINR PUSCH PUCCH

With Receive Diversity: Mi CINR PUSCH PUCCH

With AMS if

=

Mi CINR PUSCH PUCCH

TX i  ic 

TX i  ic 

CNR DLRS  T AMS

Mi

UL

UL

+ G Div + G Div TX i  ic 

TX i  ic 

or CINR DLRS  T AMS :

Mi

UL

UL

CINR PUSCH PUCCH = CINR PUSCH PUCCH + G Div + G Div Mi

P Eff

Mi Mi Mi TX i  ic  Max  P Allowed –  CINR PUSCH PUCCH –  T M + M PC   P Min   B i    UL

10.1.5

Throughput Calculation

10.1.5.1

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 SCa – FB

W FB ----------F

None

Number of subcarriers per frequency block

None

Total number of modulation symbols in downlink

TX i  ic 

N Sym – DL

590

TX i  ic 

N FB

TX i  ic 

 N Sym  SRB  N SF – DL ‘

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks TX i  ic 

R DL

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

None

Number of PDSCH modulation symbols

None

Downlink reference signals overhead

TX i  ic 

TX i  ic   N DLRS  SRB  ------------------------------  N Sym – DL  N Sym  SRB  TX i  ic 

O DLRS

Where

TX i  ic  N DLRS  SRB

   8  =  16    24 

TX i  ic 

if  N Ant – TX = 1  if

TX i  ic   N Ant – TX

= 2

if

TX i  ic   N Ant – TX

= 4 or 8 

O PSS

2  N FB – SS PBCH  N SCa – FB = 144

None

PSS overhead

O SSS

2  N FB – SS PBCH  N SCa – FB = 144

None

SSS overhead

None

PBCH overhead

None

PDCCH overhead

TX  ic 

TX i  ic 

O PBCH

i  N Res  SRB Extended CP:  4  N SCa – FB – -------------------------  N FB – SS PBCH 2  

Normal CP:  4  N SCa – FB – 2 

TX i  ic  N Ant – TX 

 N FB – SS PBCH

If N SD – PDCCH = 0 : 0 TX i  ic 

If  N SD – PDCCH = 1  AND  N Ant – TX = 4 or 8  : TX i  ic 

O PDCCH

TX i  ic 

TX i  ic   N SD – PDCCH  N SCa – FB – N Ant – TX  ------------------------------------------------------------------------------------------------  N Sym – DL N Sym  SRB TX i  ic 

 N SD – PDCCH  N SCa – FB – 2  N Ant – TX  TX i  ic  Otherwise: -----------------------------------------------------------------------------------------------------------  N Sym – DL N Sym  SRB

10.1.5.2

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 i  ic 

TX i  ic  N SCa – FB 2  ---------------------------  N Sym – UL N Sym  SRB

None

Uplink demodulation reference signal overhead

TX i  ic 

N Sym – UL TX i  ic 

R UL

O ULSRS

O ULDRS

© Forsk 2010

TX i  ic 

 N FB

TX i  ic 

– N FB – PUCCH   N Sym  SRB  N SF – UL TX i  ic 

TX i  ic 

TX i  ic 

AT283_TRG_E2

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Technical Reference Guide

10.1.5.3

Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation

Name

Value TX i  ic 

R DL



M

B

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

Uplink peak RLC channel throughput

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

i

DL Without static downlink ICIC using FFR: -----------------------------------D Frame

TX i  ic 

 M i B DL 1 -  --With static downlink ICIC using FFR: -----------------------------------D Frame 3 R DL

Mi

With MIMO (SU-MIMO):

CTP P – DL 

M

i

= 

B DL

Max

M

i

B DL

With MIMO (AMS): 

  1 + f SU – MIMO  G SU – MIMO – 1  

Mi

TX i  ic 

Max

= 

B DL

Mi

B DL TX i  ic 

if CNR DLRS  T AMS

  1 + f SU – MIMO  G SU – MIMO – 1   TX i  ic 

Mi

CTP P – DL   1 – BLER  B DL  

Mi

Mi

f TP – Scaling Mi Mi CTP E – DL  ----------------------------- – TP Offset 100

Mi

CTP P – DL  TL DL – Max

Mi

Cap P – DL   1 – BLER  B DL  

Mi

Mi f TP – Scaling Mi Cap E – DL  ----------------------------- – TP Offset 100

CTP E – DL

TX i  ic 

or CINR DLRS  T AMS Mi

Mi

CTP A – DL

TX i  ic 

Mi

Cap P – DL

Mi

Cap E – DL

Mi

Mi

Cap A – DL

TX i  ic 

R UL

 B

Mi

UL -----------------------------------D Frame

With MIMO (SU-MIMO): 

M

i

B UL Mi

CTP P – UL

= 

Max

M

i

B UL

With MIMO (AMS): 

  1 + f SU – MIMO  G SU – MIMO – 1  

Mi

TX i  ic 

Max

= 

B UL

Mi

B UL TX i  ic 

if CNR DLRS  T AMS

  1 + f SU – MIMO  G SU – MIMO – 1   TX i  ic 

TX i  ic 

or CINR DLRS  T AMS

With MIMO (MU-MIMO) in uplink throughput coverage predictions: TX i  ic 

R UL



M

B

i

TX  ic 

UL ------------------------------------  G MUi – MIMO D Frame

Mi

CTP E – UL Mi

CTP A – UL

Mi

Mi

CTP P – UL   1 – BLER  B UL   Mi CTP E – UL

Mi

f TP – Scaling Mi  ----------------------------- – TP Offset 100 TX i  ic 

Mi

CTP P – UL  TL UL – Max

Mi

Cap P – UL   1 – BLER  B UL  

Cap A – UL

Mi

Mi f TP – Scaling Mi Cap E – UL  ----------------------------- – TP Offset 100

Mi ABTP P – UL

Mi N FB – UL CTP P – UL  -------------------TX i  ic  N FB

Cap P – UL Cap E – UL

Mi

Mi

Mi

Mi

Mi

592

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks Mi

ABTP P – UL   1 – BLER  B UL  

Mi

f TP – Scaling Mi Mi ABTP E – UL  ----------------------------- – TP Offset 100

ABTP E – UL ABTP A – UL

10.1.6

Mi

Mi

kbps

Uplink effective RLC allocated bandwidth throughput

kbps

Uplink application allocated bandwidth throughput

Mi

Scheduling and Radio Resource Management

Name

Value

Unit

Description

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

None

Remaining uplink cell resources after allocation for minimum throughput demands

kbps

Remaining throughput demand for a mobile in downlink

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

Sel

Mi

TPD Min – DL -----------------------------Sel

Sel Mi

R Min – DL

Mi

CTP P – DL Sel

Mi

TPD Min – UL -----------------------------Sel

Sel

Mi R Min – UL

Mi

CTP P – UL TX i  ic  R Rem – DL

TX i  ic 



TL DL – Max –

Sel

Mi

R Min – DL

Sel

Mi

TX i  ic  R Rem – UL

TX i  ic 



TL UL – Max –

Sel

Mi

R Min – UL

Sel

Mi Sel

Mi

TPD Rem – DL

Sel

Sel

Mi

TPD Rem – UL Sel

Mi

CTP P – DL Sel

Mi CTP P – UL

Sel

Mi

Mi

TPD Max – DL – TPD Min – DL Sel

Sel

Mi

Mi

TPD Max – UL – TPD Min – UL Sel

TX i  ic 

Mi

CTP P – DL

Without MUG

 G MUG – DL

Without MUG

 G MUG – UL

Sel

TX i  ic 

Mi

CTP P – UL

Sel

Sel

Mi RD Rem – DL

Mi

TPD Rem – DL --------------------------------Sel Mi CTP P – DL Sel

Sel Mi

RD Rem – UL

Mi

TPD Rem – UL --------------------------------Sel Mi CTP P – UL

TX i  ic 

Sel R Rem – DL Mi  Proportional Fair: Min  RD Rem – DL ------------------------- N  

TX i  ic 

Sel Mi R Rem – DL  Round Robin: Min  RD Rem – DL ------------------------- N   Sel

Sel

Mi

R Max – DL

Proportional Demand:

TX i  ic  R Eff – Rem – DL

Mi

RD Rem – DL  --------------------------------------Sel Mi

 RDRem – DL Sel

Mi Sel Mi

TPD Rem – DL Max C/I: --------------------------------Sel Mi

CTP P – DL

© Forsk 2010

AT283_TRG_E2

593

Technical Reference Guide TX i  ic 

Sel R Rem – UL Mi  Proportional Fair: Min  RD Rem – UL ------------------------- N  

TX i  ic 

Sel Mi R Rem – DL  Round Robin: Min  RD Rem – DL ------------------------- N  

None

Resources allocated to a mobile to satisfy its maximum throughput demand in uplink

None

Effective remaining downlink resources in a cell (Proportional Demand)

None

Effective remaining uplink resources in a cell (Proportional Demand)

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

Sel

Sel

Mi R Max – UL

Proportional Demand:

TX i  ic  R Eff – Rem – UL

Mi

RD Rem – UL  --------------------------------------Sel Mi

 RDRem – UL Sel

Mi Sel

Mi

TPD Rem – UL Max C/I: --------------------------------Sel Mi

CTP P – UL  TX  ic  i Min  R Rem – DL  

TX i  ic  R Eff – Rem – DL

 TX  ic  i Min  R Rem – UL  

TX i  ic 

R Eff – Rem – UL

Sel

Mi

TL DL

Sel

Mi



Sel

 RDRem – UL Mi



Sel

Mi

Sel

Mi

Mi

R Min – DL + R Max – DL

Sel

Sel

Mi

Sel

Mi

= R UL

10.1.6.1



Sel

Mi

= R DL

Sel

Mi

TL UL

Sel  Mi RD Rem – DL   Sel

Mi

R Min – UL + R Max – UL

User Throughput Calculation

Name

Value

Sel

Sel

Mi

Sel

Mi

Mi

R DL  CTP P – DL

UTP P – DL

Sel

Sel

Sel

Mi Mi UTP P – DL   1 – BLER  B DL     

Mi

UTP E – DL

Sel

Sel

Sel

Mi UTP A – DL

Mi UTP E – DL

Sel

Mi

Sel f TP – Scaling Mi  ----------------------------- – TP Offset 100 Sel

Mi

Sel

Mi

Mi

R UL  CTP P – UL

UTP P – UL

Sel

Sel

Sel

Mi Mi UTP P – UL   1 – BLER  B UL     

Mi

UTP E – UL

Sel

Sel

Sel

Mi

Mi UTP E – UL

UTP A – UL

10.2

Mi

Sel Mi f TP – Scaling  ----------------------------- – TP Offset 100

Calculation Processes The following sections describe the processes of different calculations performed in Atoll and their results.

10.2.1

Point Analysis: Profile Tab The point analysis profile tab displays the following calculation results for the selected transmitter based on the calculation algorithm described in "Signal Level Calculation (DL)" on page 620.

L

594

Mi

TX i  ic 

•

Downlink reference signal level C DLRS

•

Path loss L Path

•

Total losses L Total

, G

Mi

Mi

Mi

, L Ant , L Body , and f CP are not used in the calculations performed for the profile tab.

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks

10.2.2

Point Analysis: Reception Tab Analysis provided in the Reception tab 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 signal levels for the downlink reference signals, SS, or PDSCH. Reception level bar graphs show the signal levels or RSRP in decreasing order. The maximum number of bars in the graph depends on the downlink reference 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 highest RSRP. You can use a value other than 30 dB for the margin from the highest downlink reference 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. The Reception tab calculates: • • • • • • • •

10.2.3

The RSRP and RS, SS, PBCH, PDCCH, and PDSCH signal levels from cells as explained in "Signal Level Calculation (DL)" on page 620. The RSSI, RSRQ, RS C/(I+N), SS C/(I+N), and PDSCH C/(I+N), and the RS, SS & PBCH, and PDCCH & PDSCH total noise (I+N) as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630. The best server as explained in "Best Server Determination" on page 644. The service availability as explained in "Service Area Calculation" on page 645. The PUSCH and PUCCH signal level as explained in "Signal Level Calculation (UL)" on page 634. The PUSCH and PUCCH C/(I+N) and total noise (I+N) as explained in "C/(I+N) and Bearer Calculation (UL)" on page 641. The downlink and uplink bearers as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630 and "C/(I+N) and Bearer Calculation (UL)" on page 641. The different throughputs as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

Point Analysis: Interference Tab Analysis provided in the Interference tab 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. Ten interferer bar graphs are displayed by default. This number can be changed through the Atoll.ini file. For more information on defining a different number of interferers, see the Administrator Manual. The Interference tab calculates: • • • • • • • •

10.2.4

The RS, SS, PBCH, PDCCH, and PDSCH signal levels as explained in "Signal Level Calculation (DL)" on page 620. The RS, SS, PBCH, PDCCH, and PDSCH C/(I+N) as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630. The RS, SS & PBCH, and PDCCH & PDSCH total noise (I+N) as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630. The best server as explained in "Best Server Determination" on page 644. The service availability as explained in "Service Area Calculation" on page 645. The channel overlap as explained in "Co- and Adjacent Channel Overlaps Calculation" on page 584. The collision probability due to ICIC as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630. The interference reduction due to the downlink traffic load as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630.

Downlink Reference 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

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. TX i  ic 

For these calculations, Atoll calculates the received downlink reference signal level ( C DLRS ) as explained in "Signal Level Calculation (DL)" on page 620. Then, Atoll determines the selected display criterion 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 downlink signal level based coverage

predictions. Coverage prediction parameters to be set are: • •

© Forsk 2010

The coverage prediction conditions to determine the coverage area of each studied cell, and The display settings to colour the coverage areas.

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Technical Reference Guide The following sections describe the determination of coverage area of each cell ("Coverage Area Determination" on page 596), and the display options ("Coverage Display" on page 596) of the coverage predictions.

10.2.4.1

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.

10.2.4.1.1

All Servers The coverage area of each cell TXi(ic) corresponds to the pixels where. TX i  ic 

TX i  ic 

MinimumThreshold  C DLRS  or L Total

10.2.4.1.2

TX i  ic 

or L Path

  MaximumThreshold

Best Signal Level and a Margin The coverage area of each cell TXi(ic) corresponds to the pixels where. TX i  ic 

TX i  ic 

MinimumThreshold  C DLRS  or L Total

TX i  ic 

or L Path

  MaximumThreshold

AND TX i  ic  TX j  jc  C DLRS  Best  C DLRS  – M ji

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

10.2.4.1.3

Second Best Signal Level and a Margin The coverage area of each cell TXi(ic) corresponds to the pixels where. TX i  ic 

TX i  ic 

MinimumThreshold  C DLRS  or L Total

TX i  ic 

or L Path

  MaximumThreshold

AND TX  ic 

i C DLRS  2

nd

TX  jc 

Best  C j  – M DLRS ji

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.

10.2.4.2

Coverage Display

10.2.4.2.1

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 Calculations" on page 77 for more information).

10.2.4.2.2

Display Types 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) Atoll calculates downlink reference signal levels received from cells on each pixel of the cells’ coverage areas. A pixel of a coverage area is coloured if the downlink reference signal level exceeds (  ) the defined minimum thresholds (pixel colour depends on the downlink reference signal level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as cell coverage areas. Each layer shows the different downlink reference signal levels received in the cell coverage area.

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Best Signal Level (dBm, dBµV, dBµV/m) Atoll calculates downlink reference signal levels received from cells on each pixel of the cells’ coverage areas. Where other coverage areas overlap the studied one, Atoll chooses the highest value. A pixel of a coverage area is coloured if the downlink reference signal level exceeds (  ) the defined thresholds (pixel colour depends on the downlink reference 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 downlink reference signal level from the best server exceeds a defined threshold.

Path Loss (dB) Atoll calculates path losses from cells on each pixel of the cells’ coverage areas. A pixel of a coverage area is coloured if the path loss exceeds (  ) the defined minimum thresholds (pixel colour depends on the path loss). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as cell coverage areas. Each layer shows different path loss levels in the cells’ coverage area.

Total Losses (dB) Atoll calculates total losses from cells on each pixel of the cells’ coverage areas. A pixel of a coverage area is coloured if total losses exceed (  ) the defined minimum thresholds (pixel colour depends on the total losses). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as cell coverage areas. Each layer shows different total losses levels in the cells’ coverage areas.

Best Server Path Loss (dB) Atoll calculates downlink reference signal levels received from cells on each pixel of the cells’ coverage areas. Where other coverage areas overlap the studied one, Atoll determines the best cell (i.e., the cell with the highest downlink reference signal level) and evaluates the path loss from this cell. A pixel of a coverage area is coloured if the path loss exceeds (  ) the defined thresholds (pixel colour depends on the 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 threshold.

Best Server Total Losses (dB) Atoll calculates downlink reference signal levels received from cells on each pixel of the cells’ coverage areas. Where other coverage areas overlap the studied one, Atoll determines the best cell (i.e., the cell with the highest downlink reference signal level) and evaluates the total losses from this cell. A pixel of a coverage area is coloured if the total losses exceed (  ) the defined thresholds (pixel colour depends on the 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 threshold.

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). 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 exceeds (  ) a defined threshold.

10.2.5

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 and noise at each pixel for the channel type being studied, i.e., downlink reference signals, SS, PDSCH, or PUSCH and PUCCH. 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. Coverage prediction parameters to be set are: • •

The coverage prediction conditions, and The display settings to colour the coverage areas.

The following sections describe the determination of coverage area of each cell ("Coverage Area Determination" on page 598), the calculation of the coverage parameter ("Coverage Parameter Calculation" on page 598), and the display options ("Coverage Display" on page 598) of the coverage predictions.

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10.2.5.1

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 644.

10.2.5.2

Coverage Parameter Calculation The following parameters are calculated for the Effective Signal Analysis (DL) coverage prediction. TX i  ic 

•

Best RSRP (RS EPRE) Level (DL) (dBm): E DLRS as explained in "Signal Level Calculation (DL)" on page 620.

•

Best Reference Signal Level (DL) (dBm): C DLRS as explained in "Signal Level Calculation (DL)" on page 620.

•

Best SS Signal Level (DL) (dBm): C SS

• • • •

TX i  ic 

TX i  ic 

Best PBCH Signal Level (DL) (dBm):

as explained in "Signal Level Calculation (DL)" on page 620.

TX i  ic  C PBCH

as explained in "Signal Level Calculation (DL)" on page 620.

Best PDCCH Signal Level (DL) (dBm):

TX i  ic  C PDCCH

as explained in "Signal Level Calculation (DL)" on page 620.

Best PDSCH Signal Level (DL) (dBm):

TX i  ic  C PDSCH

as explained in "Signal Level Calculation (DL)" on page 620.

Reference Signal C/N Level (DL) (dB):

TX i  ic  CNR DLRS

TX i  ic  CNR SS

as explained in "C/N Calculation (DL)" on page 628.

•

SS C/N Level (DL) (dB):

as explained in "C/N Calculation (DL)" on page 628.

•

PBCH C/N Level (DL) (dB): CNR PBCH as explained in "C/N Calculation (DL)" on page 628.

•

PDCCH C/N Level (DL) (dB): CNR PDCCH as explained in "C/N Calculation (DL)" on page 628.

•

PDSCH C/N Level (DL) (dB): CNR PDSCH as explained in "C/N Calculation (DL)" on page 628.

•

Delta Path Loss (dB): L Total – L Total

TX i  ic 

TX i  ic 

TX i  ic 

TX j  jc 

TX i  ic 

L Total

TX i  ic 

TX j  jc 

where L Total

is the total loss from the second best server TXj(jc) and

is the total loss from the best server TXi(ic) calculated as explained in "Signal Level Calculation (DL)" on

page 585. The following parameters are calculated for the Effective Signal Analysis (UL) coverage prediction. •

Mi

PUSCH & PUCCH Signal Level (UL) (dBm): C PUSCH PUCCH as explained in "Signal Level Calculation (UL)" on page 634.

•

Mi

PUSCH & PUCCH C/N Level (UL) (dB): CNR PUSCH PUCCH as explained in "C/N Calculation (UL)" on page 639.

10.2.5.3

Coverage Display

10.2.5.3.1

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 Calculations" on page 77 for more information).

10.2.5.3.2

Effective Signal Analysis (DL) Display Types It is possible to display the Effective Signal Analysis (DL) coverage prediction with colours depending on the following display options.

Best RSRP (RS EPRE) Level (DL) (dBm) Atoll calculates downlink RSRP (RS EPRE) received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the downlink RSRP (RS EPRE) exceeds (  ) the defined thresholds (the pixel colour depends on the downlinkRSRP (RS EPRE)). 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 downlink RSRP (RS EPRE) from the best server exceeds a defined threshold.

Best Reference Signal Level (DL) (dBm) Atoll calculates downlink reference signal levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the downlink reference signal level exceeds (  ) the defined thresholds (the pixel colour depends on the downlink reference 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 downlink reference signal level from the best server exceeds a defined threshold.

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Best SS Signal Level (DL) (dBm) Atoll calculates SS signal levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the SS signal level exceeds (  ) the defined thresholds (the pixel colour depends on the SS 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 SS signal level from the best server exceeds a defined threshold.

Best PBCH Signal Level (DL) (dBm) Atoll calculates PBCH signal levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the PBCH signal level exceeds (  ) the defined thresholds (the pixel colour depends on the PBCH 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 PBCH signal level from the best server exceeds a defined threshold.

Best PDCCH Signal Level (DL) (dBm) Atoll calculates PDCCH signal levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the PDCCH signal level exceeds (  ) the defined thresholds (the pixel colour depends on the PDCCH 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 PDCCH signal level from the best server exceeds a defined threshold.

Best PDSCH Signal Level (DL) (dBm) Atoll calculates PDSCH signal levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the PDSCH signal level exceeds (  ) the defined thresholds (the pixel colour depends on the PDSCH 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 PDSCH signal level from the best server exceeds a defined threshold.

Reference Signal C/N Level (DL) (dB) Atoll calculates downlink reference signal C/N levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the downlink reference signal C/N level exceeds (  ) the defined thresholds (the pixel colour depends on the downlink reference signal C/N 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 downlink reference signal C/N level from the best server exceeds a defined threshold.

SS C/N Level (DL) (dB) Atoll calculates SS C/N levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the SS C/N level exceeds (  ) the defined thresholds (the pixel colour depends on the SS C/ N 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 SS C/N level from the best server exceeds a defined threshold.

PBCH C/N Level (DL) (dB) Atoll calculates PBCH C/N levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the PBCH C/N level exceeds (  ) the defined thresholds (the pixel colour depends on the PBCH C/N 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 PBCH C/N level from the best server exceeds a defined threshold.

PDCCH C/N Level (DL) (dB) Atoll calculates PDCCH C/N levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the PDCCH C/N level exceeds (  ) the defined thresholds (the pixel colour depends on the PDCCH C/N 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 PDCCH C/N level from the best server exceeds a defined threshold.

PDSCH C/N Level (DL) (dB) Atoll calculates PDSCH C/N levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the PDSCH C/N level exceeds (  ) the defined thresholds (the pixel colour depends on the PDSCH C/N 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 PDSCH C/N level from the best server exceeds a defined threshold.

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Delta Path Loss (dB) Atoll calculates the difference of the path loss from the second best serving cells and the path loss from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the path loss difference is less than (  ) the defined thresholds (the pixel colour depends on the path loss difference). 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 delta path loss is less than a defined threshold.

10.2.5.3.3

Effective Signal Analysis (UL) Display Types 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) Atoll calculates PUSCH and PUCCH signal levels received from each pixel, of the coverage areas of the best serving cells, at the cells. A pixel of a coverage area is coloured if the PUSCH and PUCCH signal level exceeds (  ) the defined thresholds (the pixel colour depends on the PUSCH and PUCCH 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 PUSCH and PUCCH signal level at the best server exceeds a defined threshold.

PUSCH & PUCCH C/N Level (UL) (dB) Atoll calculates PUSCH and PUCCH C/N levels received from each pixel, of the coverage areas of the best serving cells, at the cells. A pixel of a coverage area is coloured if the PUSCH and PUCCH C/N level exceeds (  ) the defined thresholds (the pixel colour depends on the PUSCH and PUCCH C/N 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 PUSCH and PUCCH C/N level at the best server exceeds a defined threshold.

10.2.6

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 defaut 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 644.

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 following parameters for each subscriber in the list that has a serving base station assigned, using the properties of the default terminal and service. • • • • • • • • •

Received Reference Signal Power (DL) (dBm) as described in "Signal Level Calculation (DL)" on page 620. Received SS Power (DL) (dBm) as described in "Signal Level Calculation (DL)" on page 620. Received PDSCH Power (DL) (dBm) as described in "Signal Level Calculation (DL)" on page 620. SS & PBCH Total Noise (I+N) (DL) (dBm) as described in "C/(I+N) and Bearer Calculation (DL)" on page 630. PDSCH & PDCCH Total Noise (I+N) (DL) (dBm) as described in "C/(I+N) and Bearer Calculation (DL)" on page 630. Reference Signal C/(I+N) (DL) (dB) as described in "C/(I+N) and Bearer Calculation (DL)" on page 630. SS C/(I+N) (DL) (dB) as described in "C/(I+N) and Bearer Calculation (DL)" on page 630. PDSCH C/(I+N) (DL) (dB) as described in "C/(I+N) and Bearer Calculation (DL)" on page 630. Bearer (DL) as described in "C/(I+N) and Bearer Calculation (DL)" on page 630.

•

BLER (DL): Downlink block error rate read from the BLER vs. CINR PDSCH graph available in the LTE equipment

TX i  ic 

• •

assigned to the terminal used by the subscriber. Diversity Mode (DL): Antenna diversity mode used for the subscriber in downlink. Peak RLC Channel Throughput (DL) (kbps) as described in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649. Effective RLC Channel Throughput (DL) (kbps) as described in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649. Received PUSCH & PUCCH Power (UL) (dBm) as described in "Signal Level Calculation (UL)" on page 634. PUSCH & PUCCH Total Noise (I+N) (UL) (dBm) as described in "C/(I+N) and Bearer Calculation (UL)" on page 641. PUSCH & PUCCH C/(I+N) (UL) (dB) as described in "C/(I+N) and Bearer Calculation (UL)" on page 641. Bearer (UL) as described in "C/(I+N) and Bearer Calculation (UL)" on page 641.

•

BLER (UL): Uplink block error rate read from the BLER vs. CINR PUSCH PUCCH graph available in the LTE

• • • • •

Mi

equipment assigned to the serving cell of the subscriber.

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10.2.7

Diversity Mode (UL): Antenna diversity mode used for the subscriber in uplink. Transmission Power (UL) as described in "C/(I+N) and Bearer Calculation (UL)" on page 641. Allocated Bandwidth (UL) (No. of Frequency Blocks) as described in "C/(I+N) and Bearer Calculation (UL)" on page 641. Peak RLC Channel Throughput (UL) (kbps) as described in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649. Effective RLC Channel Throughput (UL) (kbps) as described in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

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 601. 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.

•

10.2.7.1

Scheduling and Radio Resource Management as explained under "Simulation Process" on page 604.

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 and Subscriber Lists" on page 601. "Simulations Based on Sector Traffic Maps" on page 603.

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. Note: •

Atoll follows a Poisson distribution to determine the total number of users attempting a connection in each simulation. In order for Atoll to use a constant total number of users attempting a connection, the following lines must be added to the Atoll.ini file:

[CDMA] RandomTotalUsers=0

10.2.7.1.1

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 Notes: •

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

•

The number of users is a direct input when a user profile traffic map is composed of points.

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:

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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 .

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Technical Reference Guide 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

Probability of being active in the uplink and downlink both: p Active

UL

DL

= 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). 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

DL TP Average

DL

and the uplink

and the uplink V

UL TP Average

UL

during a session.

for the service d.

UL

Calculation of activity probabilities: f

UL

DL

N Session  V  8 N Session  V  8 DL = -----------------------------------------------= -----------------------------------------------and f UL DL TP Average  3600 TP Average  3600

Probability of being inactive: p Inactive =  1 – f

UL

UL

  1 – f

Probability of being active in the uplink: p Active = f DL

UL

Probability of being active in the downlink: p Active = f

DL



 1 – f DL

DL



 1 – f

UL



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 Inactive users are not taken into account. Note:

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10.2.7.1.2

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.

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: UL

N

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 DL

the transmitter, TP Cell is the total downlink throughput demand defined in the map for any service s for the UL

coverage area of the transmitter, TP Average is the average uplink requested throughput of the service s, and DL

TP Average is the average downlink requested throughput of the service s. •

Sector Traffic Maps (# Active Users) UL

DL

Atoll directly uses the defined N and N transmitter coverage area using the service s.

values, i.e., the number of active users on UL and DL in the

At any given instant, Atoll calculates the probability for a user being active in the uplink and in the downlink as follows:

Voice Service (v) Users active in the uplink and downlink both are included in the N to accurately determine the number of active users in the uplink

UL

and N

UL ( n v – Active

DL

values. Therefore, it is necessary DL

), in the downlink ( n v – Active ), and both

UL + DL

( n v – Active ). As for the other types of traffic maps, Atoll considers both active and inactive users for voice services. 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 the number of active users trying to access the voice service v: We have: N

UL

UL

UL + DL

=  p Active + p Active   n v and N

DL

DL

UL + DL

=  p Active + p Active   n v

Where, nv is the total number of active users in the transmitter coverage area using the service v. Calculation of number of users per activity status: UL

UL + DL

DL

UL + DL

N  p Active   N  p Active UL + DL - ------------------------------------------- or Number of users active in the uplink and downlink both: n v – Active = Min  ------------------------------------------UL UL + DL UL + DL  p Active + p Active p DL  Active + p Active UL + DL

simply, n v – Active = Min  N

UL

DL

 f Act N

DL

UL

 f Act 

UL

Number of users active in the uplink: n v – Active = N

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Number of users active in the downlink: n v – Active = N UL

DL

DL

UL + DL

– n v – Active

UL + DL

And, n v = n v – Active + n v – Active + n v – Active Calculation of the number of inactive users attempting to access the service v: nv Number of inactive users: n v – Inactive = ------------------------------  p Inactive 1 – p Inactive

Data Service (d) Here, Atoll considers all the connected users as active. Activity probabilities are not calculated. Calculation of the number of users attempting to access the service d: If N

UL

N

DL

UL + DL

n d – Active = N

UL

UL

n d – Active = 0 DL

n d – Active = N If N

UL

N

DL

–N

UL

DL

UL + DL

n d – Active = N

DL

DL

n d – Active = 0 UL

n d – Active = N

UL

–N

DL

nd is the total number of active users in the TXi coverage area using the service d: UL

DL

UL + DL

n d = n d – Active + n d – Active + n d – Active Note: •

10.2.7.2

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.

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 (10 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 "Generating a Realistic User Distribution" on page 601. 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 Powers Calculation" on page 613.

-

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 

, NR UL

TX i  ic 

, r DL – ICIC ) 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 covered by the ICIC or the non-ICIC parts of the frame in downlink, as explained in "Best Server Determination" on page 644. 4. Determines the mobiles which are within the service areas of their best serving cells as explained in "Service Area Calculation" on page 645. 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 630 and "C/(I+N) and Bearer Calculation (UL)" on page 641 respectively.

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Chapter 10: LTE Networks 6. Determines the channel throughputs at the mobile as explained in "Throughput Calculation" on page 646. 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 652. 8. Calculates the user throughputs after allocating resources to each mobile as explained in "User Throughput Calculation" on page 658.

Figure 10.1LTE 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 i  ic 

TL DL

=

Mi

 RDL

TX i  ic 

and TL UL

=

Mi

Mi

 RUL Mi

TX i  ic 

For uplink MU-MIMO, TL UL



=

MU – MIMO

Mi

RC UL

MU – MIMO

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 "C/(I+N) and Bearer Calculation (UL)" on page 641. Calculation of Downlink ICIC Ratio: Atoll calculates the downlink ICIC ratio for all the cells as follows:

 TX i  ic  r DL – ICIC

© Forsk 2010

ICIC

Mi

R DL

ICIC

Mi

= ----------------------------TX i  ic  TL DL

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Mi



Where

R DL

is the sum of the percentages of the downlink cell resources allocated to mobiles in the ICIC

ICIC Mi

part of the frame. 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 

M

R UL

MU – MIMO

i G MU – MIMO = ---------------------------------------------------------MU – MIMO

Mi



RC UL

MU – MIMO

Mi

MU – MIMO

Mi



Where

is the sum of the percentages of the uplink cell resources allocated to MU-MIMO

R UL

MU – MIMO

Mi

MU – MIMO

Mi



mobiles and

is the sum of the real resource consumption of MU-MIMO mobiles.

RC UL

MU – MIMO Mi

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

TX i  ic 

TL UL

=

k

TX i  ic 

NR UL

k

=

k – 1

TX i  ic  TX i  ic  Max  TL UL – TL UL  k

k – 1

All TX i  ic 





TX i  ic  TX i  ic  Max  NR UL – NR UL  k All TX  ic  i

TX i  ic 

If TL DL

TX i  ic  TX i  ic  Max  TL DL – TL DL  k

All TX i  ic 

TX i  ic 

Req

, TL 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 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 loads Uplink traffic loads Uplink noise rise Downlink ICIC ratio Uplink ICIC noise rise Uplink MU-MIMO capacity gain 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: • • •

606

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 UL+DL. Scheduler Saturation: If the mobile is not in the list of mobiles selected for scheduling (step 7.)

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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.)

Connected mobiles (step 7.) can be: • • •

10.2.8

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 UL+DL: If a mobile active in UL+DL is allocated resources in UL+DL.

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) Coverage by Best Bearer (DL) Coverage by Throughput (DL) Coverage by Quality Indicator (DL) Coverage by C/(I+N) Level (UL) Coverage by Best Bearer (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 noninterfering 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. Coverage prediction parameters to be set are: • •

The coverage prediction conditions, and The display settings to colour the coverage areas.

The minimum thresholds at the receiver are defined in the Display parameters. The following sections describe the determination of coverage area of each cell ("Coverage Area Determination" on page 607), the calculation of the coverage parameter ("Coverage Parameter Calculation" on page 607), and the display options ("Coverage Display" on page 609) of the coverage predictions.

10.2.8.1

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 644.

10.2.8.2

Coverage Parameter Calculation The following parameters are calculated for the Coverage by C/(I+N) Level (DL) coverage prediction. TX i  ic 

•

RSRQ Level (DL) (dB): RSRQ

•

RSSI Level (DL) (dBm): RSSI

•

Reference Signal C/(I+N) Level (DL) (dB): CINR DLRS as explained in "C/(I+N) and Bearer Calculation (DL)"

TX i  ic 

as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630. as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630. TX i  ic 

on page 630. • • •

TX i  ic 

SS C/(I+N) Level (DL) (dB): CINR SS PBCH C/(I+N) Level (DL) (dB):

as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630.

TX i  ic  CINR PBCH

PDCCH C/(I+N) Level (DL) (dB):

as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630.

TX i  ic  CINR PDCCH

as explained in "C/(I+N) and Bearer Calculation (DL)" on

page 630. •

TX i  ic 

SS & PBCH Total Noise (I+N) (DL) (dBm):  I + N  SS PBCH as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630.

•

TX i  ic 

PDSCH C/(I+N) Level (DL) (dB): CINR PDSCH as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630.

•

TX i  ic 

PDSCH & PDCCH Total Noise (I+N) (DL) (dBm):  I + N PDSCH PDCCH as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630.

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Technical Reference Guide The following parameters are calculated for the Coverage by Best Bearer (DL) coverage prediction. Mi

•

Best Bearer (DL): B DL as explained in "C/(I+N) and Bearer Calculation (DL)" on page 630.

•

Modulation (DL): Modulation used by the bearer B DL calculated as explained in "C/(I+N) and Bearer Calculation

Mi

(DL)" on page 630. The following parameters are calculated for the Coverage by Throughput (DL) coverage prediction. •

Mi

Peak RLC Channel Throughput (DL) (kbps): CTP P – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Effective RLC Channel Throughput (DL) (kbps): CTP E – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Application Channel Throughput (DL) (kbps): CTP A – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Peak RLC Cell Capacity (DL) (kbps): Cap P – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Effective RLC Cell Capacity (DL) (kbps): Cap E – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Application Cell Capacity (DL) (kbps): Cap A – DL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

The following parameters are calculated for the Coverage by C/(I+N) Level (UL) coverage prediction. •

Mi

PUSCH & PUCCH C/(I+N) Level (UL) (dB): CINR PUSCH PUCCH as explained in "C/(I+N) and Bearer Calculation (UL)" on page 641.

•

TX i  ic 

PUSCH & PUCCH Total Noise (I+N) (UL) (dBm):  I + N  PUSCH PUCCH as explained in "C/(I+N) and Bearer Calculation (UL)" on page 641.

•

Mi

Allocated Bandwidth (UL) (No. of Frequency Blocks): N FB – UL as explained in "C/(I+N) and Bearer Calculation (UL)" on page 641.

•

Mi

PUSCH & PUCCH C/(I+N) Level for 1 Frequency Block (UL) (dB): CINR PUSCH  PUCCH as explained in "C/ Mi

(I+N) and Bearer Calculation (UL)" on page 641 but by fixing N FB – UL = 1 •

Mi

Transmission Power (UL) (dBm): P Eff as explained in "C/(I+N) and Bearer Calculation (UL)" on page 641.

The following parameters are calculated for the Coverage by Best Bearer (UL) coverage prediction. Mi

•

Best Bearer (UL): B UL as explained in "C/(I+N) and Bearer Calculation (UL)" on page 641.

•

Modulation (UL): Modulation used by the bearer B UL calculated as explained in "C/(I+N) and Bearer Calculation

Mi

(UL)" on page 641. The following parameters are calculated for the Coverage by Throughput (UL) coverage prediction. •

Mi

Peak RLC Channel Throughput (UL) (kbps): CTP P – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Effective RLC Channel Throughput (UL) (kbps): CTP E – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Application Channel Throughput (UL) (kbps): CTP A – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Peak RLC Cell Capacity (UL) (kbps): Cap P – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Effective RLC Cell Capacity (UL) (kbps): Cap E – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Application Cell Capacity (UL) (kbps): Cap A – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Peak RLC Allocated Bandwidth Throughput (UL) (kbps): ABTP P – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

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Mi

Effective RLC Allocated Bandwidth Throughput (UL) (kbps): ABTP E – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

•

Mi

Application Allocated Bandwidth Throughput (UL) (kbps): ABTP A – UL as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

10.2.8.3

Coverage Display

10.2.8.3.1

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 Calculations" on page 77 for more information).

10.2.8.3.2

Coverage by C/(I+N) Level (DL) Display Types 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) Atoll calculates downlink RSRQ levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the downlink RSRQ level exceeds (  ) the defined thresholds (the pixel colour depends on the downlink RSRQ 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 downlink RSRQ level from the best server exceeds a defined threshold.

RSSI Level (DL) (dBm) Atoll calculates downlink RSSI levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the downlink RSSI level exceeds (  ) the defined thresholds (the pixel colour depends on the downlink RSSI 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 downlink RSSI level from the best server exceeds a defined threshold.

Reference Signal C/(I+N) Level (DL) (dB) Atoll calculates downlink reference signal C/(I+N) levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the downlink reference signal C/(I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the downlink reference signal C/(I+N) 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 downlink reference signal C/(I+N) level from the best server exceeds a defined threshold.

SS C/(I+N) Level (DL) (dB) Atoll calculates SS C/(I+N) levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the SS C/(I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the SS C/(I+N) 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 SS C/(I+N) level from the best server exceeds a defined threshold.

SS & PBCH Total Noise (I+N) Level (DL) (dBm) Atoll calculates SS and PBCH total noise (I+N) levels received from the interfering cells on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the SS and PBCH total noise (I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the SS and PBCH total noise (I+N) 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 SS and PBCH total noise (I+N) level from the interfering cells exceeds a defined threshold.

PDSCH C/(I+N) Level (DL) (dB) Atoll calculates PDSCH C/(I+N) levels received from the best serving cells on each pixel of their coverage areas. A pixel of a coverage area is coloured if the PDSCH C/(I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the PDSCH C/(I+N) 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 PDSCH C/(I+N) level from the best server exceeds a defined threshold.

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Technical Reference Guide

PDSCH & PDCCH Total Noise (I+N) Level (DL) (dBm) Atoll calculates PDSCH and PDCCH total noise (I+N) levels received from the interfering cells on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the PDSCH and PDCCH total noise (I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the PDSCH and PDCCH total noise (I+N) 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 PDSCH and PDCCH total noise (I+N) level from the interfering cells exceeds a defined threshold.

10.2.8.3.3

Coverage by Best Bearer (DL) Display Types It is possible to display the Coverage by Best Bearer (DL) coverage prediction with colours depending on the following display options.

Best Bearer (DL) Atoll determines the best bearer available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if a bearer is available (the pixel colour depends on the available bearer). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as available bearers. Each layer corresponds to an area covered by an available bearer.

Modulation (DL) Atoll determines the modulation used by the best bearer available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if a bearer is available (the pixel colour depends on the modulation used by the available bearer). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as modulation used by bearers. Each layer corresponds to an area covered the modulation used by available bearers.

10.2.8.3.4

Coverage by Throughput (DL) Display Types 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) Atoll calculates peak RLC channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the peak RLC channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the peak RLC channel throughput). 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 peak RLC channel throughput exceeds a defined threshold.

Effective RLC Channel Throughput (DL) (kbps) Atoll calculates effective RLC channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the effective RLC channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the effective RLC channel throughput). 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 effective RLC channel throughput exceeds a defined threshold.

Application Channel Throughput (DL) (kbps) Atoll calculates application channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the application channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the application channel throughput). 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 application channel throughput exceeds a defined threshold.

Peak RLC Cell Capacity (DL) (kbps) Atoll calculates peak RLC cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the peak RLC cell capacity exceeds (  ) the defined thresholds (the pixel colour depends on the peak RLC cell capacity). 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 peak RLC cell capacity exceeds a defined threshold.

Effective RLC Cell Capacity (DL) (kbps) Atoll calculates effective RLC cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the effective RLC cell capacity exceeds (  ) the defined thresholds (the pixel colour depends on the effective RLC cell capacity). 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 effective RLC cell capacity exceeds a defined threshold.

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Application Cell Capacity (DL) (kbps) Atoll calculates application cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the application cell capacity exceeds (  ) the defined thresholds (the pixel colour depends on the application cell capacity). 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 application cell capacity exceeds a defined threshold.

10.2.8.3.5

Coverage by Quality Indicator (DL) Display Types It is possible to display the Coverage by Quality Indicator (DL) coverage prediction with colours depending on 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 LTE equipment of the selected terminal. A pixel of a coverage area is coloured if the quality indicator value exceeds (  ) the defined thresholds (the pixel colour depends on the quality indicator value). 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 quality indicator value exceeds a defined threshold.

10.2.8.3.6

Coverage by C/(I+N) Level (UL) Display Types It is possible to display the Coverage by C/(I+N) Level (UL) coverage prediction with colours depending on the following display options.

PUSCH & PUCCH C/(I+N) Level (UL) (dB) Atoll calculates PUSCH and PUCCH C/(I+N) levels received at the best serving cells from each pixel of their coverage areas. A pixel of a coverage area is coloured if the PUSCH and PUCCH C/(I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the PUSCH and PUCCH C/(I+N) 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 PUSCH and PUCCH C/(I+N) level from the pixels at the best serving cells exceeds a defined threshold.

PUSCH & PUCCH Total Noise (I+N) (UL) (dBm) Atoll calculates PUSCH and PUCCH total noise (I+N) levels received at the best serving cells from each pixel of their coverage areas. A pixel of a coverage area is coloured if the PUSCH and PUCCH total noise (I+N) level exceeds (  ) the defined thresholds (the pixel colour depends on the PUSCH and PUCCH total noise (I+N) 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 PUSCH and PUCCH total noise (I+N) level from the pixels at the best serving cells exceeds a defined threshold.

Allocated Bandwidth (UL) (No. of Frequency Blocks) Atoll calculates the number of frequency blocks at each pixel of each best serving cell’s coverage area. A pixel of a coverage area is coloured if the number of frequency blocks exceeds (  ) the defined thresholds (the pixel colour depends on the number of frequency blocks). 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 frequency blocks at the pixels of the best serving cells exceeds a defined threshold.

PUSCH & PUCCH C/(I+N) Level for 1 Frequency Block (UL) (dB) Atoll calculates PUSCH and PUCCH C/(I+N) levels for 1 frequency block received at the best serving cells from each pixel of their coverage areas. A pixel of a coverage area is coloured if the PUSCH and PUCCH C/(I+N) level for 1 frequency block exceeds (  ) the defined thresholds (the pixel colour depends on the PUSCH and PUCCH C/(I+N) level for 1 frequency block). 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 PUSCH and PUCCH C/ (I+N) level for 1 frequency block from the pixels at the best serving cells exceeds a defined threshold.

Transmission Power (UL) (dBm) Atoll calculates the uplink transmission powers corresponding to the PUSCH & PUCCH C/(I+N) received at the best serving cells from each pixel of their coverage areas. A pixel of a coverage area is coloured if the uplink transmission power exceeds (  ) the defined thresholds (the pixel colour depends on the uplink transmission power 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 uplink transmission power from the pixels at the best serving cells exceeds a defined threshold.

10.2.8.3.7

Coverage by Best Bearer (UL) Display Types It is possible to display the Coverage by Best Bearer (UL) coverage prediction with colours depending on the following display options.

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Best Bearer (UL) Atoll determines the best bearer available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if a bearer is available (the pixel colour depends on the available bearer). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as available bearers. Each layer corresponds to an area covered by an available bearer.

Modulation (UL) Atoll determines the modulation used by the best bearer available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if a bearer is available (the pixel colour depends on the modulation used by the available bearer). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as modulation used by bearers. Each layer corresponds to an area covered the modulation used by available bearers.

10.2.8.3.8

Coverage by Throughput (UL) Display Types 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) Atoll calculates peak RLC channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the peak RLC channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the peak RLC channel throughput). 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 peak RLC channel throughput exceeds a defined threshold.

Effective RLC Channel Throughput (UL) (kbps) Atoll calculates effective RLC channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the effective RLC channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the effective RLC channel throughput). 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 effective RLC channel throughput exceeds a defined threshold.

Application Channel Throughput (UL) (kbps) Atoll calculates application channel throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the application channel throughput exceeds (  ) the defined thresholds (the pixel colour depends on the application channel throughput). 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 application channel throughput exceeds a defined threshold.

Peak RLC Cell Capacity (UL) (kbps) Atoll calculates peak RLC cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the peak RLC cell capacity exceeds (  ) the defined thresholds (the pixel colour depends on the peak RLC cell capacity). 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 peak RLC cell capacity exceeds a defined threshold.

Effective RLC Cell Capacity (UL) (kbps) Atoll calculates effective RLC cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the effective RLC cell capacity exceeds (  ) the defined thresholds (the pixel colour depends on the effective RLC cell capacity). 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 effective RLC cell capacity exceeds a defined threshold.

Application Cell Capacity (UL) (kbps) Atoll calculates application cell capacity on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the application cell capacity exceeds (  ) the defined thresholds (the pixel colour depends on the application cell capacity). 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 application cell capacity exceeds a defined threshold.

Peak RLC Allocated Bandwidth Throughput (UL) (kbps) Atoll calculates peak RLC allocated bandwidth throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the peak RLC allocated bandwidth throughput exceeds (  ) the defined thresholds (the pixel colour depends on the peak RLC allocated bandwidth throughput). Coverage consists of

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Effective RLC Allocated Bandwidth Throughput (UL) (kbps) Atoll calculates effective RLC allocated bandwidth throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the effective RLC allocated bandwidth throughput exceeds (  ) the defined thresholds (the pixel colour depends on the effective RLC allocated bandwidth throughput). 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 effective RLC allocated bandwidth throughput exceeds a defined threshold.

Application Allocated Bandwidth Throughput (UL) (kbps) Atoll calculates application allocated bandwidth throughputs available on each pixel of the coverage areas of the best serving cells. A pixel of a coverage area is coloured if the application allocated bandwidth throughput exceeds (  ) the defined thresholds (the pixel colour depends on the application allocated bandwidth throughput). 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 application allocated bandwidth throughput exceeds a defined threshold.

10.2.8.3.9

Coverage by Quality Indicator (UL) Display Types It is possible to display the Coverage by Quality Indicator (UL) coverage prediction with colours depending on 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 LTE equipment of the best serving cell. A pixel of a coverage area is coloured if the quality indicator value exceeds (  ) the defined thresholds (the pixel colour depends on the quality indicator value). 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 quality indicator value exceeds a defined threshold.

10.3

Calculation Algorithms The following sections describe all the calculation algorithms used in point analysis, calculation of coverage predictions, calculations on subscriber lists, and Monte Carlo simulations.

10.3.1

Downlink Transmission Powers 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 : Cyclic prefix duration defined for the network in the Global Parameters.

•

N SD  Slot : Number of symbol durations per slot (7 is D CP is Normal, 6 if D CP is Extended).

•

N SD – PDCCH : Number of PDCCH symbol durations per subframe defined in the Global Parameters.

•

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).

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Technical Reference Guide •

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 as follows: TX i  ic 

Configuration

N SF – DL

FDD

10

DSUUU-DSUUU

2

DSUUD-DSUUD

4

DSUDD-DSUDD

6

DSUUU-DSUUD

3

DSUUU-DDDDD

6

DSUUD-DDDDD

7

DSUDD-DDDDD

8

TX i  ic 

•

N Ant – TX : Number of transmission (downlink) antenna ports defined for the cell TXi(ic).

•

P Max

•

TX i  ic  EPRE DLRS

TX i  ic 

: Maximum transmission power of the cell TXi(ic). : Downlink reference signal EPRE of the cell TXi(ic). TX i  ic 

You can either set the P Max •

TX i  ic 

EPRE SS

TX i  ic 

or EPRE DLRS for a cell.

: Energy per resource element offset for the SS with respect to the downlink reference signals

EPRE. •

TX i  ic 

EPRE PBCH : Energy per resource element offset for the PBCH with respect to the downlink reference signals EPRE.

•

TX i  ic 

EPRE PDCCH : Energy per resource element offset for the PDCCH with respect to the downlink reference signals EPRE.

•

TX i  ic 

EPRE PDSCH : Energy per resource element offset for the PDSCH with respect to the downlink reference signals EPRE.

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 614 and go directly to the section "Calculation of Other EPREs and Perchannel Powers" on page 616. 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 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 

 N Sym  SRB  N SF – DL

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:

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TX i  ic 

N Res  SRB

   8  =  16    24 

TX i  ic 

if  NAnt – TX = 1  TX i  ic 

if  N Ant – TX = 2  TX i  ic 

if  N Ant – TX = 4 or 8 

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 

 N Res  SRB

The number of modulation symbols used for downlink reference signal transmission in one scheduler resource block is:

TX i  ic  N DLRS  SRB

   8  =  8    6 

TX i  ic 

if  N Ant – TX = 1  TX i  ic 

if  N Ant – TX = 2  TX i  ic 

if  N Ant – TX = 4 or 8 

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 

 N DLRS  SRB

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: TX  ic 

i TX i  ic   N Res  SRB N Sym – PBCH =  4  N SCa – FB – -------------------------  N FB – SS PBCH for extended cyclic prefix 2  

TX i  ic 

TX i  ic 

N Sym – PBCH =  4  N SCa – FB – 2  N Ant – TX   N FB – SS PBCH for normal cyclic prefix The number of modulation symbols for the PDCCH The physical downlink control channel can be transmitted over up to 3 symbol durations in each subframe. The number of symbol durations for the PDCCH is defined in the global parameters. The physical downlink control channel overlaps with the downlink reference signals, therefore, some modulation symbols reserved for downlink reference signals are subtracted:  if  N SD – PDCCH = 0  0  TX i  ic   N TX i  ic  TX i  ic  SD – PDCCH  N SCa – FB – N Ant – TX  TX i  ic   ------------------------------------------------------------------------------------------------  N Sym if  N SD – PDCCH = 1  AND  NAnt – TX = 4 or 8  – DL N Sym – PDCCH =  N Sym  SRB  TX i  ic   N TX i  ic  SD – PDCCH  N SCa – FB – 2  N Ant – TX   ----------------------------------------------------------------------------------------------------------  N Sym – DL Otherwise  N Sym  SRB  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:

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Technical Reference Guide TX  ic  i

TX i  ic 

EPRE DLRS

 PMax  TX i  ic    ------------------10  N SD  Slot  N Slot  SF  N SF – DL – = 10  Log  10     TX i  ic 

TX i  ic 

EPRE SS EPRE PBCH  -------------------------------------------------------------------------- TX i  ic  10 10 + N Sym – PBCH  10 10  L og  N Sym – DLRS + N Sym – SS  10   TX  ic  i

+ N Sym – PDCCH  10

EPRE PDCCH ----------------------------------------10

TX  ic  i

+ N Sym – PDSCH  10

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 

TX i  ic 

TX i  ic 

= EPRE DLRS + EPRE SS

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 The instantaneous downlink reference signal transmission power is calculated as follows: TX i  ic 

TX i  ic 

TX i  ic 

P DLRS = EPRE DLRS + 10  Log  2  N FB TX i  ic 

Where 2  N FB



implies that at the instant when downlink reference signals are transmitted, they are transmitted using

2 subcarriers in each frequency block. Note: •

For more than one transmission antenna port, antenna ports 0 and 1 transmit reference signals using different subcarriers during the same OFDM symbol. An Atoll.ini option lets you include the subcarriers transmitted simultaneously on both antenna ports when calculating the instantaneous reference signal power. This means that, with this option set, TX i  ic 

Atoll will use 4  N FB

TX i  ic 

instead of 2  N FB

in the above equation.

The same Atoll.ini option lets you make Atoll apply the transmit diversity gains (the same used for PDSCH) instead of doubling the number of subcarriers used for transmitting reference signals when using more than one antenna port. For more information, see the Administrator Manual. 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    N Sym–PDCCH TX i  ic  TX i  ic  - P PDCCH = EPRE PDCCH + 10  Log  ----------------------------------------------------------TX i  ic     N SD – PDCCH  N SF – DL

The average PDSCH transmission power is calculated as follows: TX i  ic  P PDSCH

616

=

TX i  ic  EPRE PDSCH

TX i  ic    N Sym–PDSCH  -------------------------------------------------------------------------------------------------------------------------- + 10  Log TX  ic    i   N SD  Slot  N Slot  SF – N SD – PDCCH   N SF – DL

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Chapter 10: LTE Networks 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.

Output

10.3.2

TX i  ic 

•

EPRE DLRS : Energy per resource element of the downlink reference signals for cell TXi(ic).

•

EPRE SS

: Energy per resource element of the SS for cell TXi(ic).

•

TX i  ic  EPRE PBCH

: Energy per resource element of the PBCH for cell TXi(ic).

•

TX i  ic  EPRE PDCCH

: Energy per resource element of the PDCCH for cell TXi(ic).

•

TX i  ic  EPRE PDSCH

: Energy per resource element of the PDSCH for cell TXi(ic).

•

TX i  ic  P DLRS

: Instantaneous transmission power of the downlink reference signals for cell TXi(ic).

•

TX i  ic  P SS

: 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).

•

TX i  ic  P PDCCH

: Average transmission power of the PDCCH for cell TXi(ic).

•

TX i  ic  P PDSCH

: Average transmission power of the PDSCH for cell TXi(ic).

TX i  ic 

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.

Figure 10.2Co-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 TX i  ic 

TX i  ic 

of N Channel , and adjacent channel interference on the adjacent channel bandwidths, i.e., corresponding to N Channel – 1 TX i  ic 

and 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 618). 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: • • •

© Forsk 2010

"Co-Channel Overlap Calculation" on page 618. "Adjacent Channel Overlap Calculation" on page 619. "Total Overlap Ratio Calculation" on page 620.

AT283_TRG_E2

617

Technical Reference Guide

10.3.2.1

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 

N Channel

First – TX j  jc 

and N Channel

: First channel numbers the frequency band assigned to the cells TXi(ic) and

TXj(jc). •

TX i  ic 

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).

Calculations Channel numbers are converted into start and end frequencies as follows: For cell TXi(ic): TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

First – TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

First – TX i  ic 

TX j  jc 

TX j  jc 

TX j  jc 

First – TX j  jc 

TX j  jc 

TX j  jc 

TX j  jc 

First – TX j  jc 

= F Start – Band + W Channel   N Channel – N Channel

F Start

TX i  ic 



= F Start – Band + W Channel   N Channel – N Channel

F End

+ 1

For cell TXj(jc): TX j  jc 

= F Start – Band + W Channel   N Channel – N Channel

F Start

TX j  jc 



= F Start – Band + W Channel   N Channel – N Channel

F End

+ 1

Output

10.3.2.2

TX i  ic 

•

F Start

•

F End

TX i  ic 

TX j  jc 

and F Start : Start frequencies for the cells TXi(ic) and TXj(jc). TX j  jc 

and F End

: End frequencies for the cells TXi(ic) and TXj(jc).

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 618. •

TX i  ic 

F End

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 618. •

TX i  ic 

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 j  jc 

TX i  ic 

= Min  F End  F End

TX j  jc 

TX i  ic 

 – Max  F Start  F Start 

The co-channel overlap ratio is given by:

618

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks TX i  ic  – TX j  jc 

r CCO

TX i  ic  – TX j  jc 

W CCO = -------------------------------------TX i  ic  W Channel

Output •

10.3.2.3

TX i  ic  – TX j  jc 

r CCO

: Co-channel overlap ratio between the cells TXi(ic) and TXj(jc).

Adjacent 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 618. •

TX i  ic 

F End

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 618. •

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 j  jc 

TX i  ic 

TX j  jc 

TX i  ic 

TX i  ic 

= 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 

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 i  ic 

TX j  jc 

TX i  ic 

+ W Channel  – Max  F Start  F End



The higher-frequency adjacent channel overlap ratio is given by: TX i  ic  – TX j  jc 

r ACO

H

TX i  ic  – TX j  jc 

W ACO H = -------------------------------------TX i  ic  W Channel

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 •

© Forsk 2010

TX i  ic  – TX j  jc 

r ACO

: Adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc).

AT283_TRG_E2

619

Technical Reference Guide

10.3.2.4

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 618. •

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 619. TX i  ic 

•

f ACS

•

TX i  ic  W Channel

: Adjacent channel suppression factor defined for the frequency band of the cell TXi(ic). TX j  jc 

and W Channel : Bandwidths of the channels assigned to the cells TXi(ic) and TXj(jc).

Calculations The total overlap ratio is:

TX i  ic  – TX j  jc 

rO

      =       

TX  ic  i

– f ACS   ---------------------  TXi  ic  – TXj  jc  TXi  ic  – TXj  jc  10 + r ACO  10  r CCO     

TX i  ic 

TX j  jc 

TX i  ic 

TX j  jc 

if W Channel  W Channel

TX  ic  i

–f ACS   TX i  ic  --------------------- W Channel  TX i  ic  – TX j  jc  TXi  ic  – TXj  jc  10 + r ACO  10  r CCO   ----------------------  W TX j  jc  Channel  

if W Channel  W Channel

TX i  ic 

W Channel - is used to normalise the transmission power of the interfering cell TXj(jc). This means The multiplicative factor ----------------------TX j  jc  W Channel TX j  jc 

that if the interfering cell transmits at X dBm over a bandwidth of W Channel , and it interferes over a bandwidth less than TX i  ic 

TX j  jc  W Channel W Channel , the interference from this cell should not be considered at X dBm but less than that. The factor ----------------------TX j  jc  W Channel TX j  jc 

TX j  jc 

converts X dBm over W Channel to Y dBm (which is less than X dBm) over less than W Channel .

Output •

10.3.3

TX i  ic  – TX j  jc 

rO

: Total co- and adjacent channel overlap ratio between the cells TXi(ic) and TXj(jc).

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: • • • • • • • • • • •

10.3.3.1

"Signal Level Calculation (DL)" on page 585. "Noise Calculation (DL)" on page 623. "Interference Calculation (DL)" on page 624. "C/N Calculation (DL)" on page 628. "C/(I+N) and Bearer Calculation (DL)" on page 630. "Signal Level Calculation (UL)" on page 634. "Noise Calculation (UL)" on page 636. "Interference Calculation (UL)" on page 636. "Noise Rise Calculation (UL)" on page 638. "C/N Calculation (UL)" on page 639. "C/(I+N) and Bearer Calculation (UL)" on page 641.

Signal Level Calculation (DL) Input •

TX i  ic 

P DLRS : Transmission power of the downlink reference signals for cell TXi(ic) as calculated in "Downlink Transmission Powers Calculation" on page 613.

•

TX i  ic 

P SS

: Transmission power of the SS for cell TXi(ic) as calculated in "Downlink Transmission Powers

Calculation" on page 613.

620

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks TX i  ic 

•

P PBCH : Transmission power of the PBCH for cell TXi(ic) as calculated in "Downlink Transmission Powers Calculation" on page 613. TX i  ic 

•

P PDCCH : Transmission power of the PDCCH for cell TXi(ic) as calculated in "Downlink Transmission Powers Calculation" on page 613. TX i  ic 

•

P PDSCH : Transmission power of the PDSCH for cell TXi(ic) as calculated in "Downlink Transmission Powers Calculation" on page 613. TX i  ic 

EPRE DLRS : Energy per resource element of the downlink reference signals for cell TXi(ic) as calculated in

•

"Downlink Transmission Powers Calculation" on page 613. TX i  ic 

•

EPRE SS

: Energy per resource element of the SS for cell TXi(ic) as calculated in "Downlink Transmission

Powers Calculation" on page 613. TX i  ic 

EPRE PBCH : Energy per resource element of the PBCH for cell TXi(ic) as calculated in "Downlink Transmission

•

Powers Calculation" on page 613. TX i  ic 

•

EPRE PDCCH : Energy per resource element of the PDCCH for cell TXi(ic) as calculated in "Downlink Transmission Powers Calculation" on page 613. TX i  ic 

•

EPRE PDSCH : Energy per resource element of the PDSCH for cell TXi(ic) as calculated in "Downlink Transmission Powers Calculation" on page 613. TX i

TX i

G

•

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

: Transmitter antenna gain for the antenna used by the transmitter TXi ( G

TX i

•

: Total transmitter losses for the transmitter TXi ( L

TX i

= G Ant ).

= L Total – DL ).

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

: Receiver terminal losses for the pixel, subscriber, or mobile Mi.

Mi

•

G

•

Mi L Ant

: Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi. : 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 the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, Mi

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. Note: •

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. •

D CP : Cyclic prefix duration defined for the network in the Global Parameters.

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 

TX i  ic 

C DLRS = EIRP DLRS – L Path – M Shadowing – Model – L Indoor + G TX i  ic 

C SS

TX i  ic 

TX i  ic 

= EIRP SS

– L Path – M Shadowing – Model – L Indoor + G

TX i  ic 

C PBCH = EIRP PBCH – L Path – M Shadowing – Model – L Indoor + G TX i  ic 

TX i  ic 

Mi

Mi

Mi

C PDCCH = EIRP PDCCH – L Path – M Shadowing – Model – L Indoor + G © Forsk 2010

AT283_TRG_E2

–L –L –L Mi

Mi

Mi

Mi

–L

Mi

Mi

Mi

Mi

Mi

Mi

– L Ant – L Body + f CP , – L Ant – L Body + f CP , – L Ant – L Body + f CP , Mi

Mi

Mi

– L Ant – L Body + f CP , and

621

Technical Reference Guide TX i  ic 

TX i  ic 

C PDSCH = EIRP PDSCH – L Path – M Shadowing – Model – L Indoor + G

Mi

–L

Mi

Mi

Mi

– L Ant – L Body + f CP .

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 

TX i  ic 

E DLRS = EPRE DLRS + G TX i  ic 

TX i  ic 

E SS

= EPRE SS

TX i  ic 

+G

TX i  ic 

E PBCH = EPRE PBCH + G

TX i

TX i

TX i

–L –L –L

TX i  ic 

TX i  ic 

TX i

TX i  ic 

TX i  ic 

TX i

E PDCCH = EPRE PDCCH + G E PDSCH = EPRE PDSCH + G

TX i

TX i

TX i

–L –L

– L Path – M Shadowing – Model – L Indoor + G – L Path – M Shadowing – Model – L Indoor + G – L Path – M Shadowing – Model – L Indoor + G

TX i

TX i

Mi

–L

Mi

–L

Mi

–L

– L Path – M Shadowing – Model – L Indoor + G – L Path – M Shadowing – Model – L Indoor + G

Mi

Mi

Mi

Mi

Mi

Mi

Mi

Mi

Mi

– L Ant – L Body + f CP ,

Mi

– L Ant – L Body + f CP ,

–L –L

Mi

– L Ant – L Body + f CP ,

Mi

Mi

Mi

Mi

Mi

Mi

– L Ant – L Body + f CP , and – L Ant – L Body + f CP .

Where EIRP is the effective isotropic radiated power of the cell calculated as follows: TX i  ic 

TX i  ic 

EIRP DLRS = P DLRS + G TX i  ic 

EIRP SS

TX i  ic 

= P SS

TX i  ic 

+G

TX i  ic 

EIRP PBCH = P PBCH + G

TX i

TX i

TX i

–L –L –L

TX i  ic 

TX i  ic 

TX i

TX i  ic 

TX i  ic 

TX i

EIRP PDCCH = P PDCCH + G EIRP PDSCH = P PDSCH + G

TX i

TX i

TX i

–L –L

, , ,

TX i

TX i

, and .

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

Mi

–G

Mi

Mi

Mi

+ 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

  10  Log  7  7.5  If  =  10  Log  6  7.5  If  0 If  

DCP = Normal D CP = Extended TX i  ic  is an interferer

The cyclic prefix energy and the useful data bits energy are both taken into account when calculating interfering signal levels.

Output TX i  ic 

•

C DLRS : Received downlink reference signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.

•

C SS

•

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,

TX i  ic 

: Received SS signal level from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.

TX i  ic  TX i  ic  TX i  ic 

TX i  ic 

subscriber, or mobile Mi. •

622

TX i  ic 

E SS

: Received SS energy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi.

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks 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

TX i  ic 

Mi . •

TX i  ic 

E PDSCH : Received PDSCH eneregy per resource element from the cell TXi(ic) at the pixel, subscriber, or mobile Mi .

10.3.3.2

•

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.

Noise Calculation (DL) For determining the C/N and C/(I+N), Atoll calculates the downlink noise over the bandwidth used by the cell for transmitting different channels. The used bandwidth depends on the number of subcarriers used for transmission. 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. F : Subcarrier width (15 kHz).

•

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).

•

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

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 thermal noise for different downlink channels is calculated as follows: TX i  ic 

TX i  ic 

n 0 – DLRS = n 0 + 10  Log  N FB

 W FB  1000 

TX i  ic 

n 0 – SS = n 0 + 10  Log  N FB – SS PBCH  W FB  1000  TX i  ic 

n 0 – PBCH = n 0 + 10  Log  N FB – SS PBCH  W FB  1000  TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

n 0 – PDCCH = n 0 + 10  Log  N FB n 0 – PDSCH = n 0 + 10  Log  N FB

 W FB  1000   W FB  1000 

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

The downlink noise for different channels is calculated as follows: TX i  ic 

TX i  ic 

n DLRS = n 0 – DLRS + nf TX i  ic 

n SS

TX i  ic 

TX i  ic 

= n 0 – SS + nf TX i  ic 

Mi

Mi

n PBCH = n 0 – PBCH + nf TX i  ic 

TX i  ic 

Mi

n PDCCH = n 0 – PDCCH + nf

© Forsk 2010

Mi

AT283_TRG_E2

623

Technical Reference Guide TX i  ic 

TX i  ic 

n PDSCH = n 0 – PDSCH + nf

Mi

Effect of Static Downlink ICIC Using Fractional Frequency Reuse: If the cell supports Static DL ICIC, it means that a part of the LTE frame may use a fraction of the channel bandwidth. Currently, the size of the fraction is fixed to be 1/3rd of the channel bandwidth. The power transmitted over a fraction has thrice the spectral density of the power transmitted over the entire channel bandwidth. When calculating the downlink C/N and C/(I+N) ratios, the three times increase in power due to this power concentration is equivalent to a reduction in the noise level by three. Hence, in case of static downlink ICIC using FFR, the thermal noise power at the pixel, subscriber, or mobile Mi that is allocated to the ICIC part of the LTE frame is reduced by a factor of 3: TX i  ic 

TX i  ic 

n 0 – DLRS = n 0 + 10  Log  N FB 

1  W FB  1000  --- 3

TX i  ic 

TX i  ic 

1  W FB  1000  --- 3

TX i  ic 

TX i  ic 

1  W FB  1000  --- 3

n 0 – PDCCH = n 0 + 10  Log  N FB  n 0 – PDSCH = n 0 + 10  Log  N FB 

The SS and PBCH always use the centre six frequency blocks. Hence, there is no change in their noise levels. Whether a pixel, subscriber, or mobile Mi is covered by the ICIC part of the frame is determined as explained in "Best Server Determination" on page 644.

Output

10.3.3.3

TX i  ic 

•

n Sym

: Downlink noise for one subcarrier.

•

TX i  ic  n DLRS

: Downlink noise for the downlink reference signals for the cell TXi(ic).

•

TX i  ic  n SS

: Downlink noise for the SS for the cell TXi(ic).

•

TX i  ic  n PBCH

: Downlink noise for the PBCH for the cell TXi(ic).

•

TX i  ic  n PDCCH

•

n PDSCH : Downlink noise for the PDSCH for the cell TXi(ic).

: Downlink noise for the PDCCH for the cell TXi(ic).

TX i  ic 

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 j  jc 

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 620 at the pixel, subscriber, or mobile Mi covered by the cell TXi(ic).

•

TX j  jc 

E SS

: Received SS energy per resource element received from any interfering cell TXj(jc) as calculated in

"Signal Level Calculation (DL)" on page 620 at the pixel, subscriber, or mobile Mi covered by the cell TXi(ic). •

TX j  jc 

E PBCH : Received PBCH energy per resource element received from any interfering cell TXj(jc) as calculated in "Signal Level Calculation (DL)" on page 620 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 620 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 620 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, the received energies per resource element from interferers already include M Shadowing – Model , as explained in "Signal Level Calculation (DL)" on page 620.

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Chapter 10: LTE Networks In coverage predictions, the ratio M Shadowing – Model – M Shadowing – C  I is applied to the interfering signals (for more information, see "Shadowing Model" on page 115). 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 j  jc 

= E

TX j  jc 

+ 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

•

Powers Calculation" on page 613. N Sym – SS : Number of SS resource elements as calculated in "Downlink Transmission Powers Calculation" on page 613.

•

TX j  jc 

N Sym – PBCH : Number of PBCH resource elements as calculated in "Downlink Transmission Powers Calculation" on page 613.

•

TX j  jc 

N Sym – PDCCH : Number of PDCCH resource elements as calculated in "Downlink Transmission Powers Calculation" on page 613.

•

TX j  jc 

N Sym – PDSCH : Number of PDSCH resource elements as calculated in "Downlink Transmission Powers Calculation" on page 613.

•

TX j  jc 

N Sym – DL : Total number of downlink resource elements as calculated in "Downlink Transmission Powers Calculation" on page 613.

•

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 617. •

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 604. •

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).

•

F Start – Band and F Start – Band : Start frequencies of the frequency bands assigned to the cells TXi(ic) and TXj(jc).

TX i  ic 

TX j  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 

N Channel

First – TX j  jc 

and N Channel

: First channel numbers the frequency band assigned to the cells TXi(ic) and

TXj(jc). •

TX i  ic 

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).

•

ID

•

r DL – ICIC and r DL – ICIC : ICIC ratios of the cells TXi(ic) and TXj(jc).

•

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 j  jc 

Calculations 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:

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TX j  jc 

 DLRS

TX  jc  j

TX  ic  – TX  jc  i j

E PDSCH + f ICIC – DL  E DLRS TX  jc  TX  jc  - N j --------------------------------------------------------------------- N j TX j  jc   ------------------10 10 Sym – DLRS Sym – PDSCH ----------------------------------+  TL DL  ------------------------------10  = 10  Log  10 TX j  jc  TX j  jc   N Sym – DL N Sym – DL  TX j  jc 

+ 10

E PDCCH ----------------------10

 TX j  jc  N Sym – PDCCH  TX i  ic  – TX j  jc  TXj  jc  -  + fO + f MIMO  ----------------------------------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  jc 

TX j  jc 

 SS PBCH

TX  jc 

j E PBCH  ESSj ------------------- ------------------TX j  jc  10 10  N Sym – SS + 10  N Sym – PBCH TX  ic  – TX j  jc   10 -   1 – f DCi – SCa – Shift  = 10  Log  -----------------------------------------------------------------------------------------------------------------------TX j  jc   N Sym – SS + N Sym – PBCH   TX  jc  j

+ 10

E PDSCH ----------------------10



TX j  jc  

TX i  ic  – TX j  jc 

 f DC – SCa – Shift  TL DL

TX i  ic  – TX j  jc 

 + fO  

TX j  jc 

+ f MIMO

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: TX  jc  j

TX j  jc   PDSCH PDCCH

TX  jc  j

TX  ic  – TX  jc  i j

E PDSCH + f ICIC – DL  EDLRS TX  jc  TX  jc  - N j --------------------------------------------------------------------- N j TX j  jc   ------------------10 10 Sym – DLRS Sym – PDSCH ----------------------------------+  TL DL  ------------------------------10  = 10  Log  10 TX j  jc  TX j  jc   N Sym – DL N Sym – DL  TX j  jc 

+ 10

E PDCCH ----------------------10

 TX j  jc  N Sym – PDCCH  TXi  ic  – TXj  jc  TXj  jc  -  + fO + f MIMO  ----------------------------------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: TX  jc 

TX j  jc 

 RSSI

TX  ic  – TX  jc 

TX  jc 

j i j j E PDSCH + f ICIC – DL E PDCCH   TX j  jc  ------------------------------------------------------------------------------------------ E DLRS  TX j  jc  TX j  jc  TX j  jc  10 10 ------------------ N Sym – PDSCH  TL DL + 10  N Sym – PDCCH 10   10 -  10  2 + ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------= 10  Log  10 TX j  jc  TX j  jc    N Sym – PDSCH + N Sym – PDSCH    

TX i  ic  – TX j  jc 

+ fO

TX j  jc 

+ f MIMO

In OFDM symbols that contain reference signals, 2 subcarriers are used to transmit reference signals and 10 are used to transmit either PDCCH or PDSCH. TX i  ic  – TX j  jc 

Where f DC – SCa – Shift is the DC subcarrier shift factor. This factor represents the difference in the DC subcarrier frequencies of the interfered and interfering cells with respect to the SS and the PBCH bandwidth. The DC subcarrier shift factor is calculated as follows: TX  ic 

TX  jc 

i j TX i  ic  – TX j  jc   F Centre – F Centre  f DC – SCa – Shift = Min  1 ------------------------------------------------------  N FB – SS PBCH  W FB 

TX i  ic 

TX j  jc 

Where F Centre and F Centre are the centre frequencies of the channels used by TXi(ic) and TXj(jc) respectively. These are the frequencies where the DC subcarrier is located. The centre frequencies are calculated as follows: TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

First – TX i  ic 

1 + --- 2

TX j  jc 

TX j  jc 

TX j  jc 

TX j  jc 

First – TX j  jc 

1 + --- 2

For cell TXi(ic): F Centre = F Start – Band + W Channel   N Channel – N Channel  For cell TXj(jc): F Centre = F Start – Band + W Channel   N Channel – N Channel  TX j  jc 

TX j  jc 

TX j  jc 

f MIMO is the interference increment due to more than one transmission antenna port: f MIMO = 10  Log  N Ant – TX  TX j  jc 

If you do not wish to apply f MIMO , add the following lines in the Atoll.ini file:

[LTE]

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MultiAntennaInterference = 0 MultiAntennaInterference is set to 1 by default. TX i  ic  – TX j  jc 

Calculations for the interference reduction factors due to channel overlapping ( f O using fractional frequency reuse

TX i  ic  – TX j  jc  ( f ICIC – DL

) and static downlink ICIC

) 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 downlink ICIC using fractional frequency reuse: If the cell supports Static DL ICIC, it means that a part of the LTE frame may use a fraction of the channel bandwidth. Currently, the size of the fraction is fixed to be 1/3rd of the channel bandwidth. There are two effects: 1. Power concentration, which means that the spectral density of the power transmitted over a fraction of the channel 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 C/N and C/(I+N). The power transmitted over a fraction has thrice the spectral density of the power transmitted over the entire channel bandwidth. When calculating the downlink C/N and C/(I+N) ratios, the three times increase in power due to this power concentration is equivalent to a reduction in noise and interference by three. Hence, in case of static downlink ICIC using FFR, the interference at the pixel, subscriber, or mobile Mi that is allocated to the ICIC part of the LTE frame is reduced by a factor of 3. 2. Collision probability between the subcarriers used by the fractions of the channels being used by the interfered and interfering cells. The following paragraphs explain how the collision probability is calculated. The ICIC Ratio ratio is the percentage of the total downlink traffic load present in the ICIC part of the frame. For example, if the downlink traffic load is 80 %, and the ICIC ratio is 50 %, then this means that the downlink traffic load of the ICIC part of the frame is 40 % (i.e., 50 % of 80 %), and the downlink traffic load of the non-ICIC part of the frame is 40 %. In coverage predictions, Atoll uses the ICIC ratios stored in the cell properties for determining the interference. In simulations, Atoll resets the ICIC ratios for all the cells to 0, and then calculates them according to the traffic loads of the mobiles allocated to the ICIC and non-ICIC parts of the frame. Atoll determines the switching point between the ICIC and the non-ICIC parts of the frame using the ICIC ratio. 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 i  ic 

TX i  ic 

TX j  jc 

TX j  jc  r DL – ICIC r DL – ICIC = ----------------------------------------------------------------- and SP = ----------------------------------------------------------------TX i  ic  TX j  jc  TX i  ic  TX j  jc   1 – r DL – ICIC   1 – r DL – ICIC  r DL – ICIC + ------------------------------------r DL – ICIC + ------------------------------------3 3

Where, SP is the switching point between the ICIC and the non-ICIC parts of the frame, and r DL – ICIC is the downlink ICIC ratios of the cells. If the downlink ICIC ratio is set to 0, it means that the ICIC part of the frame does not exist. Setting it to 0 gives SP = 0, and setting it to 1 gives SP = 1 (or 100%), which shows how the switching point varies with the ICIC ratio. Derivation of the switching point formula: •

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 – ICIC  TL DL  1 – r DL – ICIC   TL DL ------------------------------------------ = -------------------------------------------------------W Channel  1 – SP   W Channel ----------------------SP  3

With cells using static downlink ICIC, there can be four different interference scenarios. a. Between the ICIC part of the victim and the ICIC part of the interferer. b. Between the ICIC part of the victim and the non-ICIC part of the interferer. c. Between the non-ICIC part of the victim and the ICIC part of the interferer. d. 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:

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Case

Interfered cell

Interfering cell

TX i  ic 

TX j  jc 

p Coll TX i  ic 

0 if ID PSS a

ICIC

ICIC

TX i  ic 

1 if IDPSS b

ICIC

c d

TX j  jc 

 ID PSS

TX j  jc 

= IDPSS

Non ICIC

1

Non ICIC

ICIC

1/3

Non ICIC

Non ICIC

1

The PSS ID and SSS ID are determined from the physical cell ID of a cell as follows: ID PSS = ID  Modulo 3 ID SSS = Floor  ID   3  There can be 2 cases for calculating the total probability of collision. -

Case 1: If the pixel, subscriber, or mobile Mi is covered by the ICIC part 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   a p Coll If SP  SP   TX j  jc  TX i  ic  TX j  jc  = a b + p Coll   SP – SP  TX  jc  TX i  ic  p Coll  SP  --------------------------------------------------------------------------------------------------------------------------- If SP j  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

TX j  jc  TX i  ic   d p Coll If SP  SP   TX j  jc  TX j  jc  TX i  ic  c = d  + p Coll   SP – SP  TX j  jc  TX i  ic  Coll   1 – SP  p -----------------------------------------------------------------------------------------------------------------------------------------If SP  SP TX i  ic    1 – SP  

The interference reduction factor due to static downlink ICIC using fractional frequency reuse for the pixel, subscriber, or mobile Mi is calculated as follows: TX i  ic  – TX j  jc 

f ICIC – DL

TX i  ic  – TX j  jc 

= 10  Log  p Collision



Whether a pixel, subscriber, or mobile Mi is covered by the ICIC part of the frame is determined as explained in "Best Server Determination" on page 644.

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 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).

•

TX j  jc 

 PDSCH PDCCH : 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 covered by a cell TXi(ic). TX j  jc 

TX j  jc 

 DLRS and  PDSCH PDCCH are the same. •

TX j  jc 

 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.

10.3.3.4

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 620.

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•

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 620. 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 620. 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 620. 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 620. TX i  ic 

n Sym

•

: Downlink noise for one subcarrier for the cell TXi(ic) as calculated in "Noise Calculation (DL)" on

page 623. 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 630. TX i  ic 

•

T AMS : AMS threshold defined for the cell TXi(ic).

•

T B : Bearer selection thresholds of the bearers defined in the LTE equipment used by Mi’s terminal.

•

B DL – Highest  Service  : Highest downlink bearer defined in the properties of the service used by the pixel,

Mi

Mi

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.

•

BLER  B DL  : Downlink block error rate read from the graphs available in the LTE equipment assigned to the

Mi

terminal used by the pixel, subscriber, or mobile Mi.

Calculations The C/N for cell TXi(ic) are calculated as follows for any pixel, subscriber, or mobile Mi: TX i  ic 

TX i  ic 

TX i  ic 

CNR DLRS = E DLRS – n Sym TX i  ic 

CNR SS

TX i  ic 

TX i  ic 

= E SS

TX i  ic 

– n Sym

TX i  ic 

TX i  ic 

CNR PBCH = E PBCH – n Sym TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

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 LTE 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 less than or equal to the highest bearer index 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 

DL

If the cell supports Transmit Diversity or AMS, the transmit diversity gain, G Div , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the LTE equipment assigned to the TX i  ic 

Mi

Mi

pixel, subscriber, or mobile Mi for N Ant – TX , N Ant – RX , Mobility  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 LTE equipment for which the following is true: In case of Transmit Diversity:

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DL

DL

TX i  ic 

DL

TX i  ic 

T B – G Div – G Div  CNR PDSCH In case of AMS: Mi

DL

T B – G Div – G Div  CNR PDSCH

if

TX i  ic 

TX i  ic 

CNR DLRS  T AMS

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, and Allocated Bandwidth Throughput Calculation" on page 649.

-

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, and Allocated Bandwidth Throughput Calculation" on page 649.

MIMO – Transmit Diversity Gain: Once the bearer is known, the PDSCH C/N calculated above become: In case of Transmit Diversity: TX i  ic 

TX i  ic 

DL

DL

TX i  ic 

DL

DL

CNR PDSCH = CNR PDSCH + G Div + G Div In case of AMS: TX i  ic 

CNR PDSCH = CNR PDSCH + G Div + G Div

if

TX i  ic 

TX i  ic 

CNR DLRS  T AMS

TX i  ic 

TX i  ic 

or CINRDLRS  T AMS

DL

Where G Div is the transmit diversity gain corresponding to the selected bearer.

Output

10.3.3.5

TX i  ic 

•

CNR DLRS : Downlink reference signal C/N from cell TXi(ic) at pixel, subscriber, or mobile Mi.

•

CNR SS

•

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 

: SS C/N from cell TXi(ic) at pixel, subscriber, or mobile Mi.

TX i  ic  TX i  ic  TX i  ic 

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 620) 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 624). 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 623). 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

630

•

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 : Cyclic prefix duration defined for the network in the Global Parameters.

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks •

N SD  Slot : Number of symbol durations per slot (7 is D CP is Normal, 6 if D CP is Extended).

•

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). •

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 as follows:

•

TX i  ic 

Configuration

N SF – DL

FDD

10

DSUUU-DSUUU

2

DSUUD-DSUUD

4

DSUDD-DSUDD

6

DSUUU-DSUUD

3

DSUUU-DDDDD

6

DSUUD-DDDDD

7

DSUDD-DDDDD

8

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 620.

•

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 620. •

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 620.

•

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 620.

•

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 620.

•

TX i  ic 

N Sym – DLRS : Number of downlink reference signal resource elements as calculated in "Downlink Transmission Powers Calculation" on page 613.

•

TX i  ic 

N Sym – PDCCH : Number of PDCCH resource elements as calculated in "Downlink Transmission Powers Calculation" on page 613.

•

TX i  ic 

N Sym – PDSCH : Number of PDSCH resource elements as calculated in "Downlink Transmission Powers Calculation" on page 613.

•

TX i  ic 

N Sym – DL : Total number of downlink resource elements as calculated in "Downlink Transmission Powers Calculation" on page 613.

•

TX i  ic 

TL DL

: Downlink traffic load of the interfering cell TXi(ic).

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 604. •

TX i  ic 

n Sym

: Downlink noise for one subcarrier for the cell TXi(ic) as calculated in "Noise Calculation (DL)" on

page 623. •

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) as calculated in "Interference Calculation (DL)" on page 624.

•

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 624.

•

TX j  jc 

 PDSCH PDCCH : 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 covered by a cell TXi(ic) as calculated in "Interference Calculation (DL)" on page 624. TX j  jc 

TX j  jc 

 DLRS and  PDSCH PDCCH are the same.

© Forsk 2010

AT283_TRG_E2

631

Technical Reference Guide 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 624. Inter – Tech

•

NR DL

•

TX i  ic  CNR DLRS

: Inter-technology downlink noise rise.

: Downlink reference signal C/N from cell TXi(ic) at pixel, subscriber, or mobile Mi as calculated in "C/

N Calculation (DL)" on page 628. TX i  ic 

•

T AMS : AMS threshold defined for the cell TXi(ic).

•

T B : Bearer selection thresholds of the bearers defined in the LTE equipment used by Mi’s terminal.

•

B DL – Highest  Service  : Highest downlink bearer defined in the properties of the service used by the pixel,

Mi

Mi

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.

•

BLER  B DL  : Downlink block error rate read from the graphs available in the LTE equipment assigned to the

Mi

terminal used by the pixel, subscriber, or mobile Mi.

Calculations The downlink reference signal C/(I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX j  jc 

TX i  ic 

CINR DLRS

TX i  ic 

n Sym    DLRS     -------------------- TX i  ic    ----------------- 10  10 Inter – Tech = E DLRS –  10  Log   10  + 10  + NR DL        All TX  jc        j



The SS C/(I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX j  jc 

TX i  ic  CINR SS

=

TX i  ic  E SS

TX i  ic 

n Sym    SS PBCH    - ------------------ -------------------------  10 10  Inter – Tech –  10  Log   10  + 10  + NR DL        All TX  jc        j



The PBCH C/(I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX  jc  j

TX i  ic  CINR PBCH

=

TX i  ic  E PBCH

TX  ic  i

n Sym    SS PBCH    - ------------------ -------------------------  10 10  Inter – Tech –  10  Log   10  + 10  + NR DL           All TX j  jc    



The PDCCH C/(I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX  jc  j

TX i  ic 

CINR PDCCH

TX  ic  i

  PDSCH PDCCH  n Sym     - -------------------- TX i  ic   -----------------------------------------  10 10 Inter – Tech = E PDCCH –  10  Log   10  +10 + NR DL        All TX  jc        j



The PDSCH C/(I+N) for cell TXi(ic) is calculated as follows for any pixel, subscriber, or mobile Mi: TX  jc  j

TX i  ic  CINR PDSCH

=

TX i  ic  E PDSCH

TX  ic  i

  PDSCH PDCCH  n Sym     - --------------------  -----------------------------------------  10 10 Inter – Tech –  10  Log   10  +10 + NR 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

TX i  ic 

TX i  ic 

= 10  Log  N FB

TX i  ic 

 + E DLRS – RSSI

TX i  ic 

TX i  ic 

Where RSSI 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:

632

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks TX  ic 

RSSI

TX  ic 

i i E PDSCH E PDCCH   TX i  ic  --------------------------------------------  E DLRS  TX i  ic  TX i  ic  TX i  ic  10 10 ------------------ N Sym – PDSCH  TL DL + 10  N Sym – PDCCH 10 TX  ic    10 -  10  N Anti – TX  2 + -----------------------------------------------------------------------------------------------------------------------------------------------------------------------= 10  Log   10 TX i  ic  TX i  ic    N Sym – PDSCH + N Sym – PDCCH    

TX i  ic 

TX  jc  j

TX  ic  i

n Sym   RSSI   ------------------TX i  ic   ----------------- 10  10 Inter – Tech +  12  + NR DL + 10  Log  N FB   10  + 10    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  j

I +

TX i  ic  N  DLRS

TX  ic  i

n Sym   DLRS   ------------------TX i  ic   ----------------- 10  10  Inter – Tech = 10  Log  + 10  Log  2  N FB   10  + 10  + NR 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 j  jc 

I +

TX i  ic  N  SS PBCH

TX i  ic 

n Sym   SS PBCH  - ------------------ ------------------------- Inter – Tech 10 10  = 10  Log  10 + 10 + 10  Log  N SCa – FB  N FB – SS PBCH     + NR 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: TX  jc  j

TX i  ic 

 I + N  PDSCH PDCCH

TX  ic  i

n Sym    PDSCH PDCCH  - ------------------ ----------------------------------------- 10 10  Inter – Tech = 10  Log   10  + 10  + NR DL       All TXj  jc   



TX i  ic   N TXi  ic   Sym – PDSCH + N Sym – PDCCH  + 10  Log  -----------------------------------------------------------------------------TX i  ic     N SD  Slot  N Slot  SF  N SF – DL TX i  ic 

TX i  ic 

With N SCa – FB , N Sym–PDSCH , and N Sym–PDCCH calculated as explained in "Downlink Transmission Powers Calculation" on page 613. Bearer Determination: The bearers available for selection in the pixel, subscriber, or mobile Mi’s LTE 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 less than or equal to the highest bearer index 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

TX i  ic 

Mi

DL

If the cell supports Transmit Diversity or AMS, the transmit diversity gain, G Div , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the LTE equipment assigned to the TX i  ic 

Mi

Mi

pixel, subscriber, or mobile Mi for N Ant – TX , N Ant – RX , Mobility  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 LTE equipment for which the following is true: In case of Transmit Diversity: Mi

DL

DL

TX i  ic 

DL

TX i  ic 

T B – G Div – G Div  CINR PDSCH In case of AMS: Mi

DL

T B – G Div – G Div  CINR PDSCH

if

TX i  ic 

TX i  ic 

CNR DLRS  T AMS

TX i  ic 

TX i  ic 

or CINRDLRS  T AMS

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.

-

© Forsk 2010

Peak RLC Throughput

AT283_TRG_E2

633

Technical Reference Guide 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, and Allocated Bandwidth Throughput Calculation" on page 649. -

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, and Allocated Bandwidth Throughput Calculation" on page 649.

MIMO – Transmit Diversity Gain: Once the bearer is known, the PDSCH C/(I+N) calculated above become: In case of Transmit Diversity: TX i  ic 

TX i  ic 

DL

DL

TX i  ic 

DL

DL

CINR PDSCH = CINR PDSCH + G Div + G Div In case of AMS: TX i  ic 

CINR PDSCH = CINR PDSCH + G Div + G Div

if

TX i  ic 

TX i  ic 

CNR DLRS  T AMS

TX i  ic 

TX i  ic 

or CINR DLRS  T AMS

DL

Where G Div is the transmit diversity gain corresponding to the selected bearer.

Output TX i  ic 

•

CINR DLRS : Downlink reference signal C/(I+N) from cell TXi(ic) at pixel, subscriber, or mobile Mi.

•

CINR SS

•

CINR PBCH : PBCH C/(I+N) from cell TXi(ic) at pixel, subscriber, or mobile Mi.

•

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 i  ic 

: SS C/(I+N) from cell TXi(ic) at pixel, subscriber, or mobile Mi.

TX i  ic  TX i  ic  TX i  ic 

TX i  ic 

: 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

TX i  ic 

mobile 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  PDSCH PDCCH : PDSCH and PDCCH total noise from the interfering cells TXj(jc) at the pixel, subscriber, or mobile Mi covered by a cell TXi(ic).

•

10.3.3.6

Mi

B DL : Bearer assigned to the pixel, subscriber, or mobile Mi in the downlink.

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 i  ic 

: Uplink noise rise of the cell TXi(ic). This value can be user-defined or calculated as explained in

"Interference Calculation (UL)" on page 636. TX i  ic 

•

n PUSCH PUCCH : Uplink noise for the PUSCH and the PUCCH for the cell TXi(ic).

•

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). TX i  ic 

•

 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 641.

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© Forsk 2010

Chapter 10: LTE Networks •

G

•

L

TX i

TX i

: Transmitter antenna gain for the antenna used by the transmitter TXi ( G : Total transmitter losses for the transmitter TXi ( L TX i L Ant

TX i

TX i

TX i

= G Ant ).

= L Total – UL ).

•

L Path : Path loss ( L Path = L Model +

).

•

L Total : Total loss calculated as explained in "Signal Level Calculation (DL)" on page 620.

•

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

Mi

: Receiver terminal losses for the pixel, subscriber, or mobile Mi.

Mi

•

G

•

Mi L Ant

: Receiver terminal’s antenna gain for the pixel, subscriber, or mobile Mi. : 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 the antenna patterns of the antenna used by Mi. For calculating the interfering signal level from any interferer, Mi

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 : Cyclic prefix duration defined for the network in the Global Parameters.

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 

P O_PUSCH = CINR PUSCH – Max + NR UL TX i  ic 

TX i  ic 

Where n PUSCH PUCCH – 10  Log  N FB

TX i  ic 

TX i  ic 

+ 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  N FB  + 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

C PUSCH PUCCH = EIRPPUSCH PUCCH – L Path – M Shadowing – Model – L Indoor + G

TX i

–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

+G

Mi

–L

Mi

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.

© Forsk 2010

AT283_TRG_E2

635

Technical Reference Guide 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

  10  Log  7  7.5  If D CP = Normal  =  10  Log  6  7.5  If D CP = Extended  0 If M i is an interferer  

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).

•

10.3.3.7

Mi

P Allowed : Maximum allowed transmission power for the terminal used by the pixel, subscriber, or mobile Mi.

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 •

10.3.3.8

TX i  ic 

n PUSCH PUCCH : Uplink noise for the PUSCH and the PUCCH for the cell TXi(ic).

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. The calculation of uplink interference can be divided into two parts: •

636

Calculation of the uplink interference from each individual interfering mobile as explained in "Interfering Signal Level Calculation (UL)" on page 637. AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks •

10.3.3.8.1

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 638.

Interfering Signal Level Calculation (UL) Input •

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 634.

•

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 634. In coverage predictions, the ratio M Shadowing – Model – M Shadowing – C  I is applied to the interfering signals (for more information, see "Shadowing Model" on page 115). 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 : Mj

Mj

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 617. •

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 652.

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

TX i  ic  – TX j  jc 

+ f TL – UL + f ICIC – UL

Mj

Where f TL – UL is an interference reduction factor due to the uplink traffic load of the interfering mobile Mj, calculated as follows: Mj

Mj

f TL – UL = 10  Log  TL UL  TX i  ic  – TX j  jc 

Calculations for the interference reduction factors due to channel overlapping ( f O TX i  ic  – TX j  jc 

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 UL ICIC, it means that a part of the LTE frame may use a fraction of the channel bandwidth. Currently, the size of the fraction is fixed to be 1/3rd 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 fractions of the channels

being used by the interfered and interfering cells. It is determined during Monte Carlo simulations as follows:

© Forsk 2010

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Technical Reference Guide

Case

Zone that covers the Zone that covers the mobile Mi in the interfered interfering mobile Mj in the cell TXi(ic) cell TXj(jc)

TX i  ic  – TX j  jc 

p Collision TX i  ic 

0 if IDPSS a

ICIC

ICIC

TX i  ic 

1 if ID PSS

TX j  jc 

 ID PSS

TX j  jc 

= ID PSS

b

ICIC

Non ICIC

1

c

Non ICIC

ICIC

1/3

d

Non ICIC

Non ICIC

1

The PSS ID and SSS ID are determined from the physical cell ID of a cell as follows: ID PSS = ID  Modulo 3 ID SSS = Floor  ID   3  Whether a pixel, subscriber, or mobile is covered by the ICIC part of the frame is determined as explained in "Best Server Determination" on page 644. In Monte Carlo simulations, Atoll calculates two separate noise rise values; for the mobiles located in the ICIC zone of the interfered cell Atoll calculates the ICIC UL Noise Rise, and for the mobiles located in the non-ICIC zone of the interfered cell Atoll calculates the UL Noise Rise. In coverage predictions, point analysis, and calculations on subscriber lists, according to the zone, ICIC or nonICIC, that covers the pixel, receiver, or subscriber, 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 638.

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).

10.3.3.8.2

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 637.

•

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 636.

•

Inter – Tech

NR UL

: Inter-technology uplink noise rise.

Calculations For any mobile Mi covered by the non-ICIC zone in the interfered cell TXi(ic), Atoll calculates the UL Noise Rise as follows:

TX i  ic 

NR UL

M   j  IPUSCH  TX  ic  i  PUCCH   non-ICIC M  n PUSCH PUCCH  i   ---------------------------------------------------------------------------------------------------------------------  10 10  + NR Inter – Tech – n TXi  ic  = 10  Log   10  + 10 UL PUSCH PUCCH      All M j        All TXj  jc   



For any pixel, subscriber, or mobile Mi covered by the non-ICIC zone in the interfered cell TXi(ic), Atoll calculates the 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 covered by the ICIC zone in the interfered cell TXi(ic), Atoll calculates the ICIC UL Noise Rise as follows:

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© Forsk 2010

Chapter 10: LTE Networks M   j  I PUSCH  TX i  ic   PUCCH   ICIC M  n PUSCH PUCCH  i  --------------------------------------------  ----------------------------------------------------------------- 10 10  + NR Inter – Tech – n TXi  ic  = 10  Log  10 + 10   UL PUSCH PUCCH     All Mj        All TX j  jc   

TX i  ic 



NR ICIC – UL

For any pixel, subscriber, or mobile Mi covered by the ICIC zone in the interfered cell TXi(ic), Atoll calculates the the PUSCH and PUCCH total noise (I+N) as follows: TX i  ic 

TX i  ic 

TX i  ic 

 I + N  PUSCH PUCCH = NR ICIC – UL + n PUSCH PUCCH

Output TX i  ic 

•

NR UL

: Uplink noise rise for the cell TXi(ic).

•

NR ICIC – UL : 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

TX i  ic 

TX i  ic 

mobile Mi.

10.3.3.9

C/N Calculation (UL) Input Mi

•

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 634. TX i  ic 

n PUSCH PUCCH : PUSCH and PUCCH noise for the cell TXi(ic) as calculated in "Noise Calculation (UL)" on

•

page 636. TX i  ic 

CNR DLRS : Downlink reference signal C/N from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated

•

in "C/N Calculation (DL)" on page 628. TX i  ic 

•

CINR DLRS : Downlink reference signal C/(I+N) from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated in "C/(I+N) and Bearer Calculation (DL)" on page 630. TX i  ic 

•

T AMS : AMS threshold defined for the cell TXi(ic).

•

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). TX i  ic 

•

T B – Lowest : Bearer selection threshold of the lowest bearer in the LTE 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 634. 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 Parameters.

•

T B : Bearer selection thresholds of the bearers defined in the LTE equipment used bythe cell TXi(ic).

•

B UL – Highest  Service  : Highest downlink bearer defined in the properties of the service used by the pixel,

Mi

Mi

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. 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.

•

BLER  B UL  : Uplink block error rate read from the graphs available in the LTE equipment assigned to the cell

Mi

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 © Forsk 2010

AT283_TRG_E2

639

Technical Reference Guide Bearer Determination: The bearers available for selection in the cell TXi(ic)’s LTE 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 less than or equal to the highest bearer index defined for the service being accessed by Mi.

-

Whose selection thresholds are less than the PUSCH and PUCCH C/N at Mi: T B  CNR PUSCH PUCCH

Mi

Mi

UL

If the cell supports Receive Diversity or AMS, the Receive Diversity gain, G Div , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the LTE equipment assigned to the TX i  ic 

Mi

Mi

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 LTE equipment for which the following is true: In case of Receive Diversity: Mi

UL

UL

Mi

UL

Mi

T B – G Div – G Div  CNR PUSCH PUCCH In case of AMS: Mi

UL

T B – G Div – G Div  CNR PUSCH PUCCH

if

TX i  ic 

TX i  ic 

CNR DLRS  T AMS

TX i  ic 

TX i  ic 

or CINR DLRS  T AMS

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, and Allocated Bandwidth Throughput Calculation" on page 649.

-

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, and Allocated Bandwidth Throughput Calculation" on page 649.

MIMO – Receive Diversity Gain: Once the bearer is known, the PUSCH and PUCCH C/N calculated above become: In case of Receive Diversity: Mi

Mi

UL

UL

Mi

UL

UL

CNR PUSCH PUCCH = CNR PUSCH PUCCH + G Div + G Div In case of AMS: Mi

CNR PUSCH PUCCH = CNR PUSCH PUCCH + G Div + G Div

TX i  ic 

TX i  ic 

if CNR DLRS  T AMS

TX i  ic 

TX i  ic 

or CINRDLRS  T AMS

UL

Where G Div is the receive diversity gain corresponding to the selected bearer. 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 TX i  ic 

channel 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 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

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© Forsk 2010

Chapter 10: LTE Networks PUSCH and PUCCH C/N. The calculation of the gain introduced by the bandwidth reduction is explained below. The definition of the lowest bearer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic), i.e., bearer with the lowest index, with the lowest peak RLC throughput, or with the lowest effective RLC throughput. -

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. 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:  N TX i  ic   Mi Mi FB - CNR PUSCH PUCCH = CNR PUSCH PUCCH + 10  Log  ------------------- Mi  All FB Final N  FB – UL TX i  ic 

Mi

Where N FB – UL  N FB

for any pixel, subscriber, or mobile Mi covered by the non-ICIC zone in the interfered TX i  ic 

Mi  N FB  cell TXi(ic), and N FB – UL  Cieling  ------------------- for any pixel, subscriber, or mobile Mi covered by the ICIC zone in  3 

the interfered cell TXi(ic). Uplink Power Control Adjustment: Once the bandwidth allocation is performed, Atoll continues to work with the C/N given by the bandwidth Mi

Mi

allocation, 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  M

i B UL

+ M PC , where T

TX i  ic  M

i

is the bearer selection

B UL

threshold, from the LTE 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: TX i  ic 

P Eff = Max  P Allowed –  CNR PUSCH PUCCH –  T M   B i  Mi

Mi

Mi

Mi + M PC   P Min  

UL

Mi

Mi

CNR PUSCH PUCCH is calculated again using P Eff .

Output •

10.3.3.10

Mi

CNR PUSCH PUCCH : PUSCH and PUCCH C/N from a pixel, subscriber, or mobile Mi at it serving cell TXi(ic).

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 634. Next, Atoll calculates the uplink carrier to noise ratio as explained in "C/N Calculation (UL)" on page 639. 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 638. 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

© Forsk 2010

AT283_TRG_E2

641

Technical Reference Guide 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 639. TX i  ic 

•

NR UL

•

TX i  ic  CNR DLRS

: Uplink noise rise for the cell TXi(ic) as calculated in "Noise Rise Calculation (UL)" on page 638. : Downlink reference signal C/N from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as calculated

in "C/N Calculation (DL)" on page 628. TX i  ic 

CINR DLRS : Downlink reference signal C/(I+N) from the cell TXi(ic) at the pixel, subscriber, or mobile Mi as

•

calculated in "C/N Calculation (DL)" on page 628. TX i  ic 

•

T AMS : AMS threshold defined for the cell TXi(c).

•

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). TX i  ic 

•

T B – Lowest : Bearer selection threshold of the lowest bearer in the LTE 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 634. 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 Parameters.

•

T B : Bearer selection thresholds of the bearers defined in the LTE equipment used bythe cell TXi(ic).

•

B UL – Highest  Service  : Highest downlink bearer defined in the properties of the service used by the pixel,

Mi

Mi

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. 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.

•

BLER  B UL  : Uplink block error rate read from the graphs available in the LTE equipment assigned to the cell

Mi

TXi(ic).

Calculations For any pixel, subscriber, or mobile Mi covered by the non-ICIC zone in 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

For any pixel, subscriber, or mobile Mi covered by the ICIC zone in 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 ICIC – UL Bearer Determination: The bearers available for selection in the cell TXi(ic)’s LTE 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 less than or equal to the highest bearer index 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

UL

If the cell supports Receive Diversity or AMS, the Receive Diversity gain, G Div , corresponding to the bearer is applied to its selection threshold. The gain is read from the properties of the LTE equipment assigned to the Mi

TX i  ic 

Mi

cell TXi(ic) for N Ant – TX , N Ant – RX , Mobility  M i  , BLER  B UL  .

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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 LTE equipment for which the following is true: In case of Receive Diversity: Mi

UL

UL

Mi

UL

Mi

T B – G Div – G Div  CINR PUSCH PUCCH In case of AMS: Mi

UL

T B – G Div – G Div  CINR PUSCH PUCCH

if

TX i  ic 

TX i  ic 

CNR DLRS  T AMS

TX i  ic 

TX i  ic 

or CINRDLRS  T AMS

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, and Allocated Bandwidth Throughput Calculation" on page 649.

-

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, and Allocated Bandwidth Throughput Calculation" on page 649.

MIMO – Receive Diversity Gain: Once the bearer is known, the PUSCH and PUCCH C/(I+N) calculated above become: In case of Receive Diversity: Mi

Mi

UL

UL

Mi

UL

UL

CINR PUSCH PUCCH = CINR PUSCH PUCCH + G Div + G Div In case of AMS: Mi

CINR PUSCH PUCCH = CINR PUSCH PUCCH + G Div + G Div

TX i  ic 

TX i  ic 

if CNR DLRS  T AMS

TX i  ic 

TX i  ic 

or CINR DLRS  T AMS

UL

Where G Div is the receive diversity gain corresponding to the selected bearer. 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 TX i  ic 

the channel 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 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. The definition of the lowest bearer depends on the bearer selection criterion of the scheduler used by the cell TXi(ic), i.e., bearer with the lowest index, with the lowest peak RLC throughput, or with the lowest effective RLC throughput.

-

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.

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Technical Reference Guide 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 TXi  ic   Mi Mi FB - CINR PUSCH PUCCH = CINR PUSCH PUCCH + 10  Log  ------------------- Mi  All FB Final  N FB – UL TX i  ic 

Mi

Where N FB – UL  N FB

for any pixel, subscriber, or mobile Mi covered by the non-ICIC zone in the interfered TX i  ic 

Mi  N FB  cell TXi(ic), and N FB – UL  Cieling  ------------------- for any pixel, subscriber, or mobile Mi covered by the ICIC zone in  3 

the interfered cell 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. If with P

Mi

Mi

Mi

= P Allowed AND CINR PUSCH PUCCH  T

TX i  ic  M

i B UL

+ M PC , where T

TX i  ic  M

i

is the bearer selection

B UL

threshold, from the LTE 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: TX i  ic  Mi Mi Mi Mi P Eff = Max  P Allowed –  CINR PUSCH PUCCH –  T M + M PC   P Min   B i    UL

Mi

Mi

CINR PUSCH PUCCH is calculated again using P Eff .

Output

10.3.4

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

Best Server Determination In LTE, best server refers to a cell ("serving transmitter"-"reference cell" pair) from which a pixel, subscriber, or mobile Mi TX i  ic 

gets the highest downlink reference signal level ( C DLRS ).

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 620 using the terminal and service parameters ( L Mi L Ant

, and

Mi L Body

Mi

, G

Mi

,

) of Mi.

Calculations The best server of any pixel, subscriber, or mobile Mi, BS M , is the cell from which the received downlink reference signal i

level is the highest among the downlink reference signal levels received from all the cells. The best server is determined as follows:

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TX i  ic 

C DLRS =

Best All TX i  ic 

 TX i  ic    C DLRS   

Here ic is the cell of the transmitter TXi with the highest downlink reference signal 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 lowest 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 lowest 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 lowest cell layer, the 2nd mobile to the second lowest cell layer, and so on.

•

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. •

Min DL Traffic Load: (Not implemented yet) The cell with the lowest downlink traffic load is selected as the serving (reference) cell. If more than one cell has the same lowest downlink traffic load, the first cell among all such cells is selected. During Monte Carlo simulations, as the cell traffic loads may vary, the serving cell for mobiles may also change from one iteration to the next. Min UL Traffic Load: (Not implemented yet) The cell with the lowest uplink traffic load is selected as the serving (reference) cell. If more than one cell has the same lowest uplink traffic load, the first cell among all such cells is selected. During Monte Carlo simulations, as the cell traffic loads may vary, the serving cell for mobiles may also change from one iteration to the next.

•

The Min DL Traffic Load and Min UL Traffic Load options model load balancing between cells. In coverage predictions as the probe mobile selects the least loaded cell, i.e., tries to keep the traffic load balanced between cells of the transmitter. Instead of loading already loaded cells even more, the base station chooses to load the least loaded among them. In case the cell supports static downlink ICIC using fractional frequency reuse, Atoll determines whether the pixel, subscriber, or mobile Mi is covered by the ICIC part of the frame or by the non-ICIC part of the frame. A pixel, subscriber, or mobile is covered by the ICIC part of the frame if it is considered to be at the cell edge, and it is covered by the nonICIC part otherwise. Whether a pixel, subscriber, or mobile Mi is at cell edge is determined 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

pixel,

subscriber,

BS M – 2ndBS M

+ 10  Log  r O 

i

or BS M

mobile

Mi

is

BS M

considered

to

be

a

cell

edge

if BS M

i i i  –L Total  L Path , and it is considered to be not at cell edge otherwise. Here, L Total 

i

2ndBS M

is the total loss from Mi’s best server and L Total

i

is the total loss from Mi’s second best server calculated as explained

in "Signal Level Calculation (DL)" on page 585. The second best server for a pixel, subscriber, or mobile Mi is calculated as follows: 2ndBS M = TX i  ic  i

TX  ic  i

C DLRS = BS M – 2ndBS M i

rO

i

2ndBest  TXi  ic   C All TX i  ic   DLRS   

is the total channel overlap ratio between the best server and the second best server as calculated in "CoBS M

and Adjacent Channel Overlaps Calculation" on page 617. L Path is the delta path loss threshold defined for the best i

server of the pixel, subscriber, or mobile Mi.

Output •

10.3.5

BS M : Best serving cell of the pixel, subscriber, or mobile Mi. i

Service Area Calculation In LTE, a pixel, subscriber, or mobile Mi may be covered by a cell but still outside the effective service area of the cell. A pixel, subscriber, or mobile Mi is said to be within the service area of its best serving cell TXi(ic) if the downlink reference signal energy per resource element from the cell at the pixel, subscriber, or mobile is greater than or equal to the Min RSRP defined for the cell.

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Input •

TX i  ic 

E DLRS : Downlink reference signal energy per resource element from the cell TXi(ic) at a pixel, subscriber, or mobile Mi as calculated in "Signal Level Calculation (DL)" on page 620.

•

TX i  ic 

T RSRP : Minimum RSRP 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 i  ic 

TX i  ic 

E DLRS  T RSRP

Output • •

10.3.6

True: If the calculation criterion is satisfied. False: Otherwise.

Throughput Calculation Throughputs are calculated in two steps. • •

10.3.6.1

Calculation of uplink and downlink total resources in a cell as explained in "Calculation of Total Cell Resources" on page 646. Calculation of throughputs as explained in "Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation" on page 649.

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: • •

10.3.6.1.1

"Calculation of Downlink Cell Resources" on page 646. "Calculation of Uplink Cell Resources" on page 648.

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 : Cyclic prefix duration defined for the network in the Global Parameters.

•

N SD  Slot : Number of symbol durations per slot (7 is D CP is Normal, 6 if D CP is Extended).

•

N SD – PDCCH : Number of PDCCH symbol durations per subframe defined in the Global Parameters.

•

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). •

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 as follows:

•

646

TX i  ic 

Configuration

N SF – DL

FDD

10

DSUUU-DSUUU

2

DSUUD-DSUUD

4

DSUDD-DSUDD

6

DSUUU-DSUUD

3

DSUUU-DDDDD

6

DSUUD-DDDDD

7

DSUDD-DDDDD

8

TX i  ic 

N Ant – TX : Number of transmission (downlink) antenna ports defined for the cell TXi(ic).

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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 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 

 N Sym  SRB  N SF – DL TX i  ic 

The total downlink cell resources, i.e., R DL TX i  ic 

R DL

TX i  ic 

, are calculated as follows:

TX i  ic 

TX i  ic 

TX i  ic 

= N Sym – DL – O DLRS – O PSS – O SSS – O PBCH – O PDCCH TX i  ic 

Where O DLRS is the overhead corresponding to the downlink reference signals, O PSS is the overhead corresponding to the primary synchronisation signals, O SSS is the overhead corresponding to the secondary synchronisation signals, TX i  ic 

TX i  ic 

O PBCH is the overhead corresponding to the physical broadcast channel, and O PDCCH is the overhead corresponding to the physical downlink control channel. These control channel overheads are calculated as follows: Downlink reference signal overhead The downlink reference signal overhead depends on the number of transmission antenna ports: TX i  ic 

TX i  ic  TX i  ic   N DLRS  SRB O DLRS =  ------------------------------  N Sym – DL  N Sym  SRB 

TX i  ic 

Where N DLRS  SRB

   8  =  16    24 

TX i  ic 

if  N Ant – TX = 1  TX i  ic 

if  N Ant – TX = 2  TX i  ic 

if  N Ant – TX = 4 or 8 

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: TX i  ic  O PBCH

TX  ic 

i  N DLRS  SRB =  4  N SCa – FB – -----------------------------  N FB – SS PBCH for extended cyclic prefix 2  

TX i  ic 

TX i  ic 

O PBCH =  4  N SCa – FB – 2  N Ant – TX   N FB – SS PBCH for normal cyclic prefix PDCCH overhead The physical downlink control channel can be transmitted over up to 3 symbol durations in each subframe. The number of symbol durations for the PDCCH is defined in the global parameters. The PDCCH overlaps some downlink reference signal symbols. These downlink reference signal symbols are subtracted from the PDCCH overhead:

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TX i  ic 

O PDCCH

     =      

if  N SD – PDCCH = 0 

0 TX i  ic  N Ant – TX 

 N SD – PDCCH  N SCa – FB – TX i  ic  ------------------------------------------------------------------------------------------------  N Sym – DL N Sym  SRB

TX i  ic 

if  N SD – PDCCH = 1  AND  N Ant – TX = 4 or 8 

TX i  ic 

TX i  ic   N SD – PDCCH  N SCa – FB – 2  N Ant – TX  ----------------------------------------------------------------------------------------------------------  N Sym – DL N Sym  SRB

Otherwise

Output •

10.3.6.1.2

TX i  ic 

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 : Cyclic prefix duration defined for the network in the Global Parameters.

•

N SD  Slot : Number of symbol durations per slot (7 is D CP is Normal, 6 if D CP is Extended).

•

N FB – PUCCH : Average number of PUCCH frequency blocks per frame defined in the Global Parameters.

•

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). •

TX i  ic 

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 as follows: TX i  ic 

Configuration

N SF – UL

FDD

10

DSUUU-DSUUU

6

DSUUD-DSUUD

4

DSUDD-DSUDD

2

DSUUU-DSUUD

5

DSUUU-DDDDD

3

DSUUD-DDDDD

2

DSUDD-DDDDD

1

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 i  ic 

TX i  ic 

N Sym – UL =  N FB

TX i  ic 

– 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:

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Chapter 10: LTE Networks 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 O ULSRS = ---------------------------  N Sym – 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 O ULDRS = 2  ---------------------------  N Sym – UL N Sym  SRB

Output •

10.3.6.2

TX i  ic 

R UL

: Amount of uplink resources in the cell TXi(ic).

Channel Throughput, Cell Capacity, and Allocated Bandwidth 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.

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 646. TX i  ic 

•

R UL

•

page 646.  M : Bearer efficiency (bits/symbol) of the bearer assigned to the pixel, subscriber, or mobile Mi in the downlink

: Amount of uplink resources in the cell TXi(ic) as calculated in "Calculation of Total Cell Resources" on

i

B DL

•

in "C/(I+N) and Bearer Calculation (DL)" on page 630.  M : Bearer efficiency (bits/symbol) of the bearer assigned to the pixel, subscriber, or mobile Mi in the uplink in i

B UL

•

"C/(I+N) and Bearer Calculation (UL)" on page 641. D Frame : Frame duration.

•

CNR DLRS : Downlink reference signals C/N from the cell TXi(ic) as calculated in "C/N Calculation (DL)" on

TX i  ic 

page 628. •

TX i  ic 

CINR DLRS : Downlink reference signals C/(I+N) from the cell TXi(ic) as calculated in "C/N Calculation (DL)" on page 628. TX i  ic 

•

T AMS : Adaptive MIMO switch 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).

•

BLER  B DL  : Downlink block error rate read from the BLER vs. CINR PDSCH graph available in the LTE

TX i  ic 

TX i  ic 

TX i  ic 

Mi

equipment assigned to the terminal used by the pixel, subscriber, or mobile Mi. •

Mi

Mi

BLER  B UL  : Uplink block error rate read from the BLER vs. CINR PUSCH PUCCH graph available in the LTE 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 FB

TX i  ic 

: Number of frequency blocks, defined in the frequency bands table, for the channel bandwidth used by

the cell TXi(ic).

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Technical Reference Guide •

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 641.

Calculations Downlink: TX i  ic 

•

Peak RLC Channel Throughput:

R DL

Mi CTP P – DL



M

B

i

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. Static Downlink ICIC using Fractional Frequency Reuse: If the pixel, subscriber, or mobile Mi is covered by the ICIC part of the frame (determined as explained in "Best Server Determination" on page 644), the channel throughput is calculated as: TX i  ic 

Mi CTP P – DL

R DL



M

i

B DL 1 -  --= -----------------------------------D Frame 3

MIMO – SU-MIMO Gain: Max

If the cell supports SU-MIMO or AMS, SU-MIMO gain G SU – MIMO is applied to the bearer efficiency. The gain is read from the properties of the LTE equipment assigned to the pixel, subscriber, or mobile Mi for: 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,

Mi

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

Mi

Bearer Calculation (DL)" on page 630. Mi

BLER  B DL  : Downlink block error rate read from the graphs available in the LTE equipment assigned to the

-

TX i  ic 

terminal used by the pixel, subscriber, or mobile Mi. BLER is determined for CINR PDSCH . 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: 

M

i

= 

B DL

Max

M

i

B DL

  1 + f SU – MIMO  G SU – MIMO – 1  

In case of AMS: 

M

i B DL

= 

TX i  ic 

Max

M

i B DL

  1 + f SU – MIMO  G SU – MIMO – 1  

TX i  ic 

if CNR DLRS  T AMS

TX i  ic 

TX i  ic 

or CINR DLRS  T AMS

If the Max SU-MIMO Gain for the exact value of the C/(I+N) is not availabe 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). Mi

Mi

Mi

•

Effective RLC Channel Throughput: CTP E – DL = CTP P – DL   1 – BLER  B DL  

•

Mi Mi f TP – Scaling Mi Application Channel Throughput: CTP A – DL = CTP E – DL  ----------------------------- – TP Offset 100

•

Peak RLC Cell Capacity: Cap P – DL = CTP P – DL  TL DL – Max

•

Effective RLC Cell Capacity: Cap E – DL = Cap P – DL   1 – BLER  B DL  

Mi

•

Mi

Mi

Application RLC Capacity:

TX i  ic 

Mi

Mi Cap A – DL

Mi

=

Mi Cap E – DL

Mi

Mi

f TP – Scaling Mi  ----------------------------- – TP Offset 100

Uplink: TX i  ic 

•

650

Peak RLC Channel Throughput:

Mi CTP P – UL

AT283_TRG_E2

R UL



M

B

i

UL = -----------------------------------D Frame

© Forsk 2010

Chapter 10: LTE Networks 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. MIMO – SU-MIMO Gain: Max

If the cell supports SU-MIMO or AMS, SU-MIMO gain G SU – MIMO is applied to the bearer efficiency. The gain is read from the properties of the LTE equipment assigned to the cell TXi(ic) for: Mi

-

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.

-

B UL : Bearer assigned to the pixel, subscriber, or mobile Mi in the uplink as explained in "C/(I+N) and Bearer

Mi

Calculation (UL)" on page 641. Mi

BLER  B UL  : Uplink block error rate read from the graphs available in the LTE equipment assigned to the cell

-

Mi

TXi(ic). BLER is determined for CINR PUSCH PUCCH . 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

Max

Mi

B UL

  1 + f SU – MIMO  G SU – MIMO – 1  

In case of AMS: 

M

i B UL

= 

Max

M

i B UL

  1 + f SU – MIMO  G SU – MIMO – 1  

TX i  ic 

TX i  ic 

TX i  ic 

CNR DLRS  T AMS

if

TX i  ic 

or CINRDLRS  T AMS

If the Max SU-MIMO Gain for the exact value of the C/(I+N) is not availabe 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): TX i  ic 

TX i  ic 

TX i  ic 

TX i  ic 

If the cell supports MU-MIMO and CNR DLRS  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). TX i  ic 

M

R UL

 B

Mi

TX  ic 

i UL -  G MUi – MIMO CTP P – UL = -----------------------------------D Frame

Mi

Mi

Mi

•

Effective RLC Channel Throughput: CTP E – UL = CTP P – UL   1 – BLER  B UL  

•

Application Channel Throughput:

Mi CTP A – UL

•

Peak RLC Cell Capacity: Cap P – UL = CTP P – UL  TL UL – Max

•

Effective RLC Cell Capacity: Cap E – UL = Cap P – UL   1 – BLER  B UL  

•

f TP – Scaling Mi Mi Mi Application Cell Capacity: Cap A – UL = Cap E – UL  ----------------------------- – TP Offset 100

•

Mi Mi N FB – UL Peak RLC Allocated Bandwidth Throughput: ABTP P – UL = CTP P – UL  -------------------TX i  ic  N FB

•

Effective RLC Allocated Bandwidth Throughput: ABTP E – UL = ABTP P – UL   1 – BLER  B UL  

•

f TP – Scaling Mi Mi Mi Application Allocated Bandwidth Throughput: ABTP A – UL = ABTP E – UL  ----------------------------- – TP Offset 100

Mi

=

Mi CTP E – UL

TX i  ic 

Mi

Mi

Mi

f TP – Scaling Mi  ----------------------------- – TP Offset 100

Mi

Mi

Mi

Mi

Mi

Mi

Mi

Mi

Output

© Forsk 2010

Mi

•

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.

Mi

AT283_TRG_E2

651

Technical Reference Guide

10.3.7

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.

•

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.

Mi Mi Mi

Mi Mi Mi

Mi Mi Mi

Mi Mi Mi

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 652 and the calculation of user throughputs is explained in "User Throughput Calculation" on page 658.

10.3.7.1

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.

•

BLER  B DL  : Downlink block error rate read from the BLER vs. CINR PDSCH graph available in the LTE

TX i  ic 

TX i  ic 

Mi

: Priority of the service accessed by a mobile Mi. Mi Mi Mi Mi

TX i  ic 

Mi

equipment assigned to the terminal used by the mobile Mi. •

Mi

Mi

BLER  B UL  : Uplink block error rate read from the BLER vs. CINR PUSCH PUCCH graph available in the LTE 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 RLC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on

Mi

Mi

page 646. •

Mi

CTP P – UL : Uplink peak RLC channel throughput at the mobile Mi as calculated in "Throughput Calculation" on page 646.

•

Mi

ABTP P – UL : Uplink peak RLC allocated bandwidth throughput at the mobile Mi as calculated in "Throughput Calculation" on page 646.

652

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks

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 i  ic 

The scheduler selects N Users mobiles for the scheduling and RRM process. If the Monte Carlo user distribution has TX i  ic 

generated a number of users which is less than N Users – Max , the scheduler keeps all the mobiles generated for the cell TXi(ic). TX i  ic 

TX i  ic 

TX i  ic 

N Users = Min  N Users – Max N Users – Generated  TX i  ic 

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 RLC, effective RLC, or application throughput. Therefore: •

Target Throughput = Peak RLC Throughput Sel

Sel

Mi

Mi

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

Sel

Downlink:

Mi TPD Min – DL

Sel

Mi

Mi

Sel

Mi TPD Min – DL TPD Max – DL , TPD Max – DL = --------------------------------------------------= --------------------------------------------------Sel Sel Mi   1 – BLER  B  1 – BLER  B Mi   DL DL       Sel

Mi Mi Mi Sel Min  TPD Max – UL ABTP P – UL Mi TPD Min – UL   , TPD Max – UL = ---------------------------------------------------------------------------------= --------------------------------------------------Sel Sel  1 – BLER  B Mi    1 – BLER  B Mi    UL    UL     Sel

Sel

Uplink:

•

Mi TPD Min – UL

Target Throughput = Application Throughput Sel

Downlink:

Mi Mi Sel Mi TPD Min – DL + TP Offset TPD Min – DL = -------------------------------------------------------------------------------------Sel  1 – BLER  B Mi    f Mi   DL   TP – Scaling

Sel

,

Mi Mi Sel Mi TPD Max – DL + TP Offset TPD Max – DL = -------------------------------------------------------------------------------------Sel  1 – BLER  B Mi    f Mi   DL   TP – Scaling

Sel

Uplink:

Mi Mi Sel Mi TPD Min – UL + TP Offset TPD Min – UL = -------------------------------------------------------------------------------------Sel  1 – BLER  B Mi    f Mi  UL   TP – Scaling  Sel

,

Min  TPD Max – UL ABTP P – UL + TP Offset   TPD Max–UL = --------------------------------------------------------------------------------------------------------------Sel Mi Mi  1 – BLER  B   f   UL   TP – Scaling Mi

Sel Mi

Mi

Mi

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 641. Resource Allocation for Minimum Throughput Demands: Sel

1. Atoll sorts the M i

Sel

Sel

TX i  ic 

 N Users in order of decreasing service priority, p Sel

2. Starting with M i

= 1 up to M i

Mi

.

TX i  ic 

= 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

Sel

Mi R Min – DL

Mi

Sel

Mi

Sel

Mi TPD Min – DL TPD Min – UL = ------------------------------ and R Min – UL = -----------------------------Sel Sel Mi

CTP P – DL

Mi

CTP P – UL

3. Atoll stops the resource allocation in downlink or uplink,

© Forsk 2010

AT283_TRG_E2

653

Technical Reference Guide

-

Sel

TX i  ic 

Mi



When/If in downlink

R Min – DL = TL DL – Max , i.e., the resources available in downlink have been used up

Sel

Mi

for satisfying the minimum throughput demands of the mobiles. Sel

-

When/If in uplink

TX i  ic 

Mi

 RMin – UL = TLUL – 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 UL+DL must be able to get their minimum throughput demands in both UL and DL in order to be considered connected UL+DL. If an active UL+DL 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

Sel

Mi

Mi

bandwidth throughput ( TPD Min – UL  ABTP P – UL ) are rejected due to Resource Saturation. Sel

6. If

Sel

TX i  ic 

Mi

 RMin – DL  TLDL – Max Sel

TX i  ic 

Mi

 RMin – UL  TLUL – Max , and all the minimum throughput resources demanded

or

Sel

Mi

Mi

by the mobiles have been allocated, Atoll goes to the next step for allocating resources to satisfy the maximum throughput demands. The remaining cell resources available for the next step are: TX i  ic 

Sel

TX i  ic 

Mi

 RMin – DL

Downlink: R Rem – DL = TL DL – Max –

Sel

Mi TX i  ic 

TX i  ic 

Uplink: R Rem – UL = TL UL – Max –



Sel

Mi

R Min – UL

Sel

Mi

Resource Allocation for Maximum Throughput Demands: 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

Sel

Mi

Sel

Mi

Mi

Downlink: TPD Rem – DL = TPD Max – DL – TPD Min – DL Sel

Sel

Mi

Sel

Mi

Mi

Uplink: TPD Rem – UL = TPD Max – UL – TPD Min – UL For the remaining throughput demands of the mobiles, the following resource allocation methods are available: 1. 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. Sel

Let the total number of users be N  M i

. TX i  ic 

TX i  ic 

a. Each user’s channel throughput is increased by the multi-user diversity gain G MUG – DL or G MUG – UL read Sel

from the 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

Without MUG Mi

Mi

Sel

Max

TX i  ic 

TX i  ic 

Mi

 G MUG – DL and CTP P – UL = CTP P – UL

Sel

TX i  ic 

Sel

TX i  ic 

Mi

CTP P – DL = CTP P – DL

Without MUG

 G MUG – UL

Sel

Mi

Max

G MUG – DL = 1 if CINR PDSCH  CINR MUG 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 availabe 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:

654

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks Sel

Sel

Mi RD Rem – DL

Sel

Mi

Mi

Sel

Mi TPD Rem – DL TPD Rem – UL = --------------------------------and RD Rem – UL = --------------------------------Sel Sel Mi

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: TX i  ic 

TX i  ic 

Sel Sel Sel Sel Mi Mi R Rem – DL Mi Mi R Rem – UL   R Max – DL = 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. e. Atoll stops the resource allocation in downlink or uplink, Sel

-

TX i  ic 

Mi

 RMax – DL = RRem – DL , i.e., the resources available in downlink have been used

When/If in downlink

Sel

Mi

up for satisfying the maximum throughput demands of the mobiles. -



When/If in uplink

Sel

TX i  ic 

Mi

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 i  ic 

Sel

TX i  ic 

R Rem – DL = TL DL – Max –

Sel

Mi

Mi

 RMin – DL –  RMax – DL Sel Mi

TX i  ic 

TX i  ic 

R Rem – UL = TL UL – Max –



and

Sel Mi Sel

Mi



R Min – UL –

Sel

Sel

Mi

R Max – UL

Sel

Mi

Mi

h. Atoll repeats the all the above steps for the users whose maximum throughput demands have not been TX i  ic 

TX i  ic 

satisfied until either R Rem – DL = 0 and R Rem – UL = 0 , or all the maximum throughput demands are satisfied. 2. 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

Sel

Mi RD Rem – DL

Sel

Mi

Sel

Mi

Mi TPD Rem – DL TPD Rem – UL and RD Rem – UL = --------------------------------= --------------------------------Sel Sel Mi

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: TX i  ic 

TX i  ic 

Sel Sel Sel Sel R Rem – DL R Rem – UL Mi Mi Mi Mi   R Max – DL = 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. d. Atoll stops the resource allocation in downlink or uplink,

© Forsk 2010

AT283_TRG_E2

655

Technical Reference Guide

-



When/If in downlink

Sel

TX i  ic 

Mi

R Max – DL = R Rem – DL , i.e., the resources available in downlink have been used

Sel

Mi

up for satisfying the maximum throughput demands of the mobiles. Sel

-

TX i  ic 

Mi

 RMax – UL = RRem – UL , i.e., the resources available in uplink have been used up for

When/If in uplink

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

 Sel

Mi Sel

TX i  ic 

R Rem – UL = TL UL – Max –

Sel

Mi

R Max – DL and

Sel

Mi TX i  ic 



R Min – DL –

Sel

Mi

Mi

 RMin – UL –  RMax – UL Sel

Sel

Mi

Mi

g. Atoll repeats the all the above steps for the users whose maximum throughput demands have not been TX i  ic 

TX i  ic 

satisfied until either R Rem – DL = 0 and R Rem – UL = 0 , or all the maximum throughput demands are satisfied. 3. 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

Sel

Mi RD Rem – DL

Sel

Mi

Mi

Sel

Mi TPD Rem – DL TPD Rem – UL and RD Rem – UL = --------------------------------= --------------------------------Sel Sel Mi

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:  TX  ic  TX i  ic  i R Eff – Rem – DL = Min  R Rem – DL  

Sel



 TX  ic  TX i  ic  i and R Eff – Rem – UL = Min  R Rem – UL   

 RDRem – DL Mi

Sel

Mi

Sel



 RDRem – UL Mi

Sel

Mi



c. The resources allocated to each user by the Proportional Demand scheduling method for satisfying its maximum throughput demands are: Sel

Sel

Mi R Max – DL

=

TX i  ic  R Eff – Rem – DL

Sel

Mi

Mi

Sel RD Rem – DL Mi TX i  ic  RD Rem – UL - and R Max  --------------------------------------– UL = R Eff – Rem – UL  --------------------------------------Sel Sel

Mi

Mi

 RDRem – DL

 RDRem – UL

Sel

Sel

Mi

Mi

4. 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

Sel

Mi R Max – DL

Mi

Sel

Sel

Mi

Mi

CTP P – DL

656

Mi

Mi TPD Rem – DL TPD Rem – UL and R Max – UL = --------------------------------= --------------------------------Sel Sel

CTP P – UL

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks c. Atoll stops the resource allocation in downlink or uplink, Sel

-

TX i  ic 

Mi

 RMax – DL = RRem – DL , i.e., the resources available in downlink have been used

When/If in downlink

Sel

Mi

up for satisfying the maximum throughput demands of the mobiles. Sel

-

TX i  ic 

Mi

 RMax – UL = RRem – UL , i.e., the resources available in uplink have been used up for

When/If in uplink

Sel

Mi

satisfying the maximum throughput demands of the mobiles. Spatial Multiplexing with Uplink Multi-User MIMO: MU-MIMO lets the system/scheduler work with two parallel LTE 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. TX i  ic 

TX i  ic 

TX i  ic 

MU-MIMO can be used if the cell supports MU-MIMO, CNR DLRS  T MU – MIMO , and N Ant – RX  2 . Let i be the index of connected MU-MIMO mobiles: i = 1 to N MU – MIMO

MU – MIMO

Each mobile M i

Mi

has a corresponding traffic load TL UL

MU – MIMO

. The scheduling starts with available real MU – MIMO

Mi = 0

Mi = 0

= 100 % and available virtual resources V UL

resources RR UL

= 0 % . i = 0 means no MU-MIMO

mobile has yet been scheduled. MU – MIMO

MU – MIMO

The virtual resource consumption of a mobile M i

Mi

is given by: VC UL MU – MIMO

MU – MIMO

The real resource consumption of a mobile M i

Mi

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

MU – MIMO

Mi

– VC UL

Mi

MU – MIMO

Mi

= TL UL

MU – MIMO

 

Mi – 1

 V UL

MU – MIMO

Mi

– VC UL

are given by:

MU – MIMO

Mi

+ RC UL

MU – MIMO

TX i  ic 

Mi

 RCUL

Saturation occurs when

MU – MIMO

= Min  TL UL 

= TL UL – Max .

The following table gives an example: MU – MIMO

Mi

Mobile

MU – MIMO

Mi

(%)

TL UL

MU – MIMO

(%)

VC UL

Mi

MU – MIMO

(%)

RC UL

Mi

V UL

(%)

M1

10

0

10

10

M2

5

5

0

5

M3

20

5

15

15

M4

40

15

25

25

…

…

…

…

…

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

Mi

Downlink: TL DL Sel

Mi

Uplink: TL UL

Sel

Mi

= R DL Sel

Mi

= R UL

Sel

Sel

Mi

Mi

= R Min – DL + R Max – DL Sel

Mi

Sel

Mi

= R Min – UL + R Max – UL

Output Sel

•

© Forsk 2010

Mi

TL DL

Sel

Mi

Sel

= R DL : Downlink traffic load or the amount of downlink resources allocated to the mobile M i

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657

Technical Reference Guide Sel

•

10.3.7.2

Mi

TL UL

Sel

Mi

Sel

= R UL : Uplink traffic load or the amount of uplink resources allocated to the mobile M i

.

User Throughput Calculation User throughputs are calculated for the percentage of resources allocated to each mobile selected by the scheduling for Sel

RRM during the Monte Carlo simulations, M i

.

Input Sel

•

Mi

Sel

R DL : Amount of downlink resources allocated to the mobile M i

as calculated in "Scheduling and Radio

Resource Allocation" on page 652. 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 652. Sel

•

Mi

Sel

CTP P – DL : Downlink peak RLC channel throughput at the mobile M i

as calculated in "Throughput Calculation"

on page 646. Sel

•

Mi

Sel

CTP P – UL : Uplink peak RLC channel throughput at the mobile M i

as calculated in "Throughput Calculation" on

page 646. Sel

•

Mi TX i  ic  BLER  B DL  : Downlink block error rate read from the BLER vs. CINR PDSCH graph available in the LTE   Sel

equipment assigned to the terminal used by the mobile M i •

.

Sel Mi

BLER  B UL  : Uplink block error rate read from the BLER vs. CINR PUSCH PUCCH graph available in the LTE   equipment assigned to the cell TXi(ic). Mi

Sel

• •

Mi

Sel

f TP – Scaling : Throughput scaling factor defined in the properties of the service used by the mobile M i Sel Mi

Sel

TP Offset : Throughput offset defined in the properties of the service used by the mobile M i

.

.

Calculations Downlink: Sel

Sel

Mi

Sel

Mi

Mi

•

Peak RLC User Throughput: UTP P – DL = R DL  CTP P – DL

•

Mi Mi Mi Effective RLC User Throughput: UTP E – DL = UTP P – DL   1 – BLER  B DL     

Sel

Sel

Sel

Sel

Sel

•

Application User Throughput:

Mi UTP A – DL

Sel

=

Mi UTP E – DL

Mi

Sel f TP – Scaling Mi  ----------------------------- – TP Offset 100

Uplink: Sel

Sel

Mi

Sel

Mi

Mi

•

Peak RLC User Throughput: UTP P – UL = R UL  CTP P – UL

•

Mi Mi Mi Effective RLC User Throughput: UTP E – UL = UTP P – UL   1 – BLER  B UL     

Sel

Sel

Sel

Sel

Sel

•

Application User Throughput:

Mi UTP A – UL

Sel

=

Mi UTP E – UL

Mi

Sel f TP – Scaling Mi  ----------------------------- – TP Offset 100

Output Sel

• • • • •

658

Mi

Sel

UTP P – DL : Downlink peak RLC user throughput at the pixel, subscriber, or mobile M i

.

Sel Mi

Sel

UTP E – DL : Downlink effective RLC user throughput at the pixel, subscriber, or mobile M i Sel Mi

Sel

UTP A – DL : Downlink application user throughput at the pixel, subscriber, or mobile M i Sel Mi

Sel

UTP P – UL : Uplink peak RLC user throughput at the pixel, subscriber, or mobile M i Sel Mi

.

. Sel

UTP E – UL : Uplink effective RLC user throughput at the pixel, subscriber, or mobile M i

AT283_TRG_E2

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.

© Forsk 2010

Chapter 10: LTE Networks Sel

•

10.4

Mi

Sel

UTP A – UL : Uplink application user throughput at the pixel, subscriber, or mobile M i

.

Automatic Allocation Algorithms The following sections describe the algorithms for: • • • •

10.4.1

"Automatic Neighbour Allocation" on page 659. "Automatic Inter-Technology Neighbour Allocation" on page 661. "Automatic Frequency Planning" on page 663. "Automatic Physical Cell ID Allocation" on page 667.

Automatic Neighbour Allocation The intra-technology neighbour allocation 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. Note: •

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. 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. 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 10.3Determination of Adjacent Cells -

Force Neighbour 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.

© Forsk 2010

The neighbour list of TXj(jc) is not full, Atoll will add TXi(ic) to the end of the list.

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659

Technical Reference Guide 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). -

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. The coverage areas of TXi(ic) and TXj(jc) must have an overlap ( S TX  ic   S TX  jc  ). 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 reference signal energy per resource element is greater than or equal to the minimum TX i  ic 

TX i  ic 

RSRP: E DLRS  T RSRP

TX i  ic 

TX i  ic 

S TX  ic  is the surface area covered by TXi(ic) within E DLRS and E DLRS + M RSRP . M RSRP is the RSRP

-

i

margin with respect to the best downlink reference signal energy per resource element at which the handover ends. S TX  jc  is the coverage area where the candidate cell TXj(jc) is the best server.

-

j

Note: •

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.

When the above

conditions are met, Atoll calculates the percentage of the

coverage area

overlap

S TX  ic   S TX  jc  i j -  100 ), and compares this value with the % Min Covered Area. TXj(jc) is considered a neighbour of ( -------------------------------------------S TX  ic  i

S TX  ic   S TX  jc  i j -  100  % Min Coverage Area . TXi(ic) if -------------------------------------------S TX  ic  i

Figure 10.4Overlapping 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 importance (%) of neighbours depends on the reason of allocation:

660

Neighbour 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 %

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© Forsk 2010

Chapter 10: LTE Networks

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)

The importance is evaluated using an Importance Function (IF), which takes into account the following factors: • • •

Co-site factor (C): a Boolean, Adjacency factor (A): the percentage of adjacency, 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

Overlapping factor (O) Adjacency factor (A)

Min(O)

1%

Max(O)

30 %

Min(A)

30 %

Max(A)

60 %

Co-site factor (C)

Min(C)

60 %

Max(C)

100 %

The Importance Function is evaluated as follows:

Neighbour Cause Co-site

Importance Function

Adjacent

IF with Default Values

No

No

Min(O) + Delta(O)(O)

1 % + 29 %(O)

No

Yes

Min(A)+Delta(A){Max(O)(O)+(100 %-Max(O))(A)}

30 % + 30 %{30 %(O) + 70 %(A)}

Yes

Yes

Min(C)+Delta(C){Max(O)(O)+(100 %-Max(O))(A)}

60 % + 40 %{30 %(O )+ 70 %(A)}

Where Delta(x) = Max(x) - Min(x) Notes: •

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 not be ranked by neighbour cause.

•

The ranking between neighbours from the same category depends on (A) and (O) factors.

•

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 greater than 0 % only if there is some overlapping.

In the results, Atoll lists only the cells for which it finds new neighbours.

10.4.2

Automatic Inter-Technology Neighbour Allocation The inter-technology neighbour allocation 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. Note: •

© Forsk 2010

If no focus zone exists in the .atl document, Atoll takes into account the computation zone.

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661

Technical Reference Guide 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. 2. The calculation options: -

-

-

CDMA Carriers: This option is available when an LTE network is being co-planned with a UMTS, CDMA, or TD-SCDMA 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: When allocation algorithm is based on distance, 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 = 0.5% so that the maximum variation in D does not to exceed 1%. D is stated in m.

Figure 10.5Inter-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. This formula is not used when allocation algorithm is based on coverage overlapping. In this case, the actual inter-transmitter distance is considered. -

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.

662

AT283_TRG_E2

© Forsk 2010

Chapter 10: LTE Networks SA  SB Atoll calculates the percentage of the coverage area overlap ( ----------------------  100 ) and compares this value with SA SA  SB the % 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 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

d 1 – -----------d max

d is the 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: -

Co-site factor (C): a Boolean, 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

Overlapping factor (O) Co-site factor (C)

Min(O)

1%

Max(O)

60 %

Min(C)

60 %

Max(C)

100 %

Default Value

The IF evaluates importance as follows:

Co-site

Importance Function

IF with Default Values

No

Min(O) + Delta(O)(O)

1 % + 59 %(O)

Yes

Min(C) + Delta(C)(O)

60 % + 40 %(O)

Where Delta(x) = Max(x) - Min(x) Notes: •

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 not be ranked by neighbour cause.

•

The ranking between neighbours from the same category depends on (A) and (O) factors.

In the results, Atoll displays only the cells for which it finds new neighbours.

© Forsk 2010

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Technical Reference Guide

10.4.3

Automatic Frequency Planning 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 automatic allocation method for carrier frequencies in LTE networks, which takes into account interference matrices, neighbour relations, and distance between transmitters. The frequency allocation algorithm 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. Note: •

10.4.3.1

If no focus zone exists in the .atl document, Atoll takes into account the computation zone.

Separation Constraint and Relationship Weights The AFP algorithm is based on a cost function which takes into account the following separation constraints: •

Required channel separation  Req -

For co-site cells: 2 channel bandwidths of the TBA cell. For neighbour cells: 1 channel bandwidth of the TBA cell.

The above separation 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 "Take Neighbours into Account" 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 "Take Min Reuse Distance into Account" is selected, Assigned weight  Dis tan ce = 0.2 Notes:

10.4.3.2

•

The sum of the weights assigned to the above relations is 1.

•

These default weights can be modified through the Atoll.ini file. For more information, see the Administrator Manual.

Calculation of Cost Between TBA and Related Cells Atoll calculates the separation constraint violation level between the TBA cell TXi(ic) and its related cell TXj(jc) as follows:

TX i  ic  – TX j  jc  VL Sep

   =    

TX i  ic  – TX j  jc 

Where  Req

  TX i  ic  – TX j  jc  –  TXi  ic  – TXj  jc  Req  --------------------------------------------------------------------------------- TX i  ic  – TX j  jc     Req  

2

0

if 

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

  Req

Otherwise

is the required separation, and 

TX i  ic  – TX j  jc 

is the actual separation between channels used by

TXi(ic) and TXj(jc) calculated as follows: 

664

TX i  ic  – TX j  jc 

TX j  jc 

TX i  ic 

F Start – F Start = -----------------------------------------TX i  ic  W Channel

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© Forsk 2010

Chapter 10: LTE Networks TX j  jc 

Where F Start TX j  jc 

F Start

TX i  ic 

F Start

TX i  ic 

F Start

is the start frequency of the channel used by TXj(jc) calculated as follows:

TX j  jc 

TX j  jc 

TX j  jc 

= F Start – Band + W Channel  N Channel is the start frequency of the channel used by TXi(ic) calculated as follows: TX i  ic 

TX i  ic 

TX i  ic 

= F Start – Band + W Channel  N Channel TX i  ic 

TX j  jc 

Where F Start – Band and F Start – Band are the start frequencies of the frequency bands assigned to the cells TXi(ic) and TXj(jc) respectively. F Start – Band can be the start frequency of a TDD frequency band ( F Start – TDD ), or the downlink start TX i  ic 

TX j  jc 

frequency of an FDD frequency band ( F Start – FDD – DL ). N Channel and N Channel are the channel numbers assigned to cells TXi(ic) and TXj(jc) respectively. 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 

And, W Channel and W Channel are the bandwidths of the channels assigned to cells TXi(ic) and TXj(jc) respectively. The cost of the relation between the TBA cell and its related cell is calculated next: $

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

= VL Sep

TX i  ic  – TX j  jc 

Where  Neighbour

TX i  ic  – TX j  jc 

   Neighbour   Neighbour

TX i  ic  – TX j  jc 

+  Dis tan ce   Dis tan ce

TX i  ic  – TX j  jc 

 +  IM   IM

TX i  ic  – TX j  jc 

is the importance of the relationship between the TBA and its related neighbour cell,  IM

TX i  ic  – TX j  jc 

is the importance of the relationship between the TBA cell and its related interfering cell, and  Dis tan ce

is the

importance of the relationship between the TBA and its related cell with respect to the distance between them. TX i  ic  – TX j  jc 

 Neighbour

is calculated during automatic neighbour allocation by Atoll as explained in "Automatic Neighbour

Allocation" on page 659. For manual neighbour allocation, this value is equal to 1. TX i  ic  – TX j  jc 

 IM

TX i  ic  – TX j  jc 

 IM

•

is calculated during the interference matrices calculation as follows: =

Co-channel interference probability (i.e., for Floor   S TX  ic  i

TX i  ic  – TX j  jc 

 = 0 ):

TX i  ic   C TXj  jc  + M  n  -------------------------------------------------------Quality Max DLRS  --------------------- 10 10   TX i  ic  C DLRS – 10  Log  10 + 10    T RSRP + 174 – 10  Log  15000        TX i  ic 

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX  ic  i

•

Adjacent channel interference probability (i.e., for Floor   S TX  ic  i

TX i  ic  – TX j  jc 

 = 1:

TX i  ic  TX i  ic   C TXj  jc  + M  +f n  -----------------------------------------------------------------------------------Quality ACS Max DLRS  ----------------------- TX i  ic   10 10 + 10 C DLRS – 10  Log  10    T RSRP + 174 – 10  Log  15000        TX i  ic 

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX  ic  i

Otherwise, i.e., for other values of Floor  

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

 ,  IM

= 0 TX i  ic 

TX i  ic 

Where 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

as calculated in "Service Area Calculation" on page 645. S TX  ic  i

is the best server coverage area of the cell Condition

TXi(ic) where the given condition is true. TX i  ic 

TX j  jc 

C DLRS is the received downlink reference signal level from the cell TXi(ic). C Max from the cell TXj(jc) calculated using the Max Power defined for this cell.

TX i  ic  n DLRS

is the received maximum signal level

is the downlink noise for the cell TXi(ic)

as calculated in "Noise Calculation (DL)" on page 623. M Quality is the quality margin used for the interference matrices TX i  ic 

calculation. And, f ACS

© Forsk 2010

is the adjacent channel suppression factor defined for the frequency band of the cell TXi(ic).

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Technical Reference Guide TX i  ic  – TX j  jc 

In words,  IM

is equivalent to a probability of interference calculated by taking the ratio of the interfered surface

area to the total surface area of a cell. Two interference probabilities are calculated for each interfered-interfering cell pair, i.e., for co-channel and adjacent channel interference. TX i  ic  – TX j  jc 

 Dis tan ce

is calculated by the AFP as follows:

TX i  ic  – TX j  jc   Dis tan ce

  1  D Reuse  2   =  Log   -------------------------------------    D TX i  ic  – TX j  jc     --------------------------------------------------------------2  Log  D Reuse  

if D

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 calculated as follows: D D

TX i  ic  – TX j  jc  TX i  ic  – TX j  jc 

joining 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)

  1 + x   cos    – cos    – 2  

is weighted according to the orientations of the TBA cell and its related cell with respect to the straight line TX i  ic  – TX j  jc 

is the distance between the two cells considering any offsets with respect to the site locations. TX i  ic  – TX j  jc 

x is set to 15 % so that the maximum variation in D due to the azimuths does not exceed 60 %.  and  are calculated from the azimuths of the two cells as shown in Figure 10.6 on page 666.

Figure 10.6Weighted 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 10.7 on page 666. 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 10.7Importance Based on Distance Relation 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 allocation 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 

666

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© Forsk 2010

Chapter 10: LTE Networks 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 i  ic 

10.4.3.3

AFP Algorithm The AFP algorithm is an iterative algorithm which: • • • •

10.4.4

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.

Automatic Physical Cell ID Allocation 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 automatic allocation method for physical cell IDs in an LTE network, which takes into account the distance between transmitters, the frequency plan of the network (i.e., co- and adjacent channel interference probabilities), and the neighbour relations. The physical cell ID allocation algorithm 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 status is not set to locked, They satisfy the filter criteria applied to the Transmitters folder, They are located inside the focus zone. Note: •

10.4.4.1

If no focus zone exists in the .atl document, Atoll takes into account the computation zone.

Constraint and Relationship Weights The automatic physical cell ID allocation algorithm is based on a cost-based function which takes into account the following constraints, in the order of priority: 1. Same physical cell ID, Assigned weight  ID = 0.5 2. Same PSS ID, Assigned weight  PSS = 0.25 3. Same SSS ID, Assigned weight  SSS = 0.25 Notes:

© Forsk 2010

•

The sum of the weights assigned to the above constraints is 1.

•

These default weights can be modified through the Atoll.ini file. For more information, see the Administrator Manual.

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Technical Reference Guide The above separation 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 "Take Neighbours into Account" is selected, Assigned weight  Neighbour = 0.35 Neighbours of a TBA cell are also related to each other through the TBA cell. This relation is also taken into account, Assigned weight  Inter – Neighbour = 0.15 You can choose to not take into account the inter-neighbour physical cell ID collision by adding an option in the Atoll.ini file (see the Administrator Manual). If inter-neighbour collision is not taken into account, the weight assigned to the neighbour relation alone is  Neighbour = 0.5 and that of the inter-neighbour collision is of course  Inter – Neighbour = 0 .

•

Cells that are listed in the interference matrix of the TBA cell (available with the AFP module only), Assigned weight  IM = 0.3

•

Cells within the cell’s (or the default) minimum reuse distance, if the check box "Take Min Reuse Distance into Account" is selected, Assigned weight  Dis tan ce = 0.2 Notes:

10.4.4.2

•

The sum of the weights assigned to the above relations is 1.

•

These default weights can be modified through the Atoll.ini file. For more information, see the Administrator Manual.

Calculation of Cost Between TBA and Related Cells Atoll calculates the constraint violation level between the TBA cell TXi(ic) and its related cell TXj(jc) as follows: VL

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

= IL SS

ID

PSS

SSS

   ID  p Coll +  PSS  p Coll +  SSS  p Penalty 

Where  ID ,  PSS , and  SSS are the weights assigned to the physical cell ID, PSS ID, and SSS ID constraints. TX i  ic  – TX j  jc 

IL SS

TX i  ic  – TX j  jc 

IL SS

is the SS interference level between TXi(ic) and TXj(jc) calculated as follows: TX i  ic  – TX j  jc 

= rO

TX i  ic  – TX j  jc 

Where r O

TX i  ic  – TX j  jc  TX j  jc      1 – f DC – SCa – Shift   1 – TL DL   

is the total channel overlap ratio between the TXi(ic) and TXj(jc) as calculated in "Co- and Adjacent TX i  ic  – TX j  jc 

Channel Overlaps Calculation" on page 617. f DC – SCa – Shift is the DC subcarrier shift factor. This factor represents the difference in the DC subcarrier frequencies of the interfered and interfering cells with respect to the SS bandwidth. The DC subcarrier shift factor is calculated as follows: TX  ic 

TX  jc 

i j TX i  ic  – TX j  jc   F Centre – F Centre  f DC – SCa – Shift = Min  1 ------------------------------------------------------  N FB – SS PBCH  W FB 

TX i  ic 

TX j  jc 

Where F Centre and F Centre are the centre frequencies of the channels used by TXi(ic) and TXj(jc) respectively. These are the frequencies where the DC subcarrier is located. The centre frequencies are calculated as follows: TX i  ic  TX i  ic  TX i  ic  TX i  ic  1 For cell TXi(ic): F Centre = F Start – Band + W Channel   N Channel + ---  2 TX j  jc  TX j  jc  TX j  jc  TX j  jc  1 For cell TXj(jc): F Centre = F Start – Band + W Channel   N Channel + ---  2

  1 ID ID p Coll is the physical cell ID collision probability given by p Coll =    0   1 PSS PSS p Coll is the PSS ID collision probability given by p Coll =    0

668

AT283_TRG_E2

TX i  ic 

if ID 

TX i  ic 

if ID  TX i  ic 

if ID PSS

TX i  ic 

if ID PSS

TX j  jc 

= ID 

TX j  jc 

.

 ID 

TX j  jc 

= ID PSS

TX j  jc 

.

 ID PSS

© Forsk 2010

Chapter 10: LTE Networks   SSS SSS p Penalty is the SSS ID penalty given by p Penalty =  1  0 

TX i  ic 

if ID SSS

TX j  jc 

 ID SSS

AND

Site

TX i  ic 

= Site

TX j  jc 

if the

Otherwise SSS

SSS ID allocation strategy is set to "Same per Site", and by p Penalty = 0 if the SSS ID allocation strategy is set to "Free". The SSS penalty models the SSS ID allocation constraint. Next, Atoll calculates the importance of the relation between the TBA cell and its related cell. TX i  ic  – TX j  jc 

 Total

TX  ic  – TX j  jc 

i =  Neighbour   Neighbour

 IM  TX i  ic  – TX j  jc 

Where  Neighbour

TX i  ic  – TX j  jc   IM

+  Inter – Neighbour   Inter – Neighbour + TX i  ic  – TX j  jc 

+  Dis tan ce   Dis tan ce

is the importance of the relationship between the TBA cell and its related neighbour cell, TX i  ic  – TX j  jc 

 Inter – Neighbour is the importance of the relationship between two neighbours of the TBA cell,  IM

is the

importance of the relationship between the TBA cell and its related interfering cell (available with the AFP module only), TX i  ic  – TX j  jc 

and  Dis tan ce

is the importance of the relationship between the TBA and its related cell with respect to the distance

between them. TX i  ic  – TX j  jc 

 Neighbour

is calculated during automatic neighbour allocation by Atoll as explained in "Automatic Neighbour

Allocation" on page 659. For manual neighbour allocation, this value is equal to 1.  Inter – Neighbour is calculated from the neighbour relationship importance values calculated during automatic neighbour allocation. If two neighbours of the TBA cell have the same physical cell ID assigned, the importance of the inter-neighbour physical cell ID collision is the average of their neighbour importance values with the TBA 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 

TX i  ic  – TX j2  j2c 

+  Neighbour   Neighbour  Max =  ----------------------------------------------------------------------------------------- 2   All Neighbour Pairs

 Inter – Neighbour

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. TX i  ic  – TX j  jc 

 IM

TX i  ic  – TX j  jc 

 IM

•

is calculated during the interference matrices calculation as follows: =

Co-channel interference probability (i.e., for Floor   S TX  ic  i

TX i  ic  – TX j  jc 

 = 0 ):

TX i  ic   C TXj  jc  + M  n DLRS   -------------------------------------------------------Max Quality --------------------- 10 10   TX i  ic  C DLRS – 10  Log  10 + 10    T RSRP + 174 – 10  Log  15000        TX i  ic 

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX  ic  i

•

Adjacent channel interference probability (i.e., for Floor   S TX  ic  i

TX i  ic  – TX j  jc 

 = 1:

TX i  ic  TX i  ic   C TXj  jc  + M  n DLRS   -----------------------------------------------------------------------------------Max Quality + f ACS ----------------------- TX i  ic   10 10 C DLRS – 10  Log  10 + 10    T RSRP + 174 – 10  Log  15000        TX i  ic 

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------S TX  ic  i

Otherwise, i.e., for other values of Floor  

TX i  ic  – TX j  jc 

TX i  ic  – TX j  jc 

 ,  IM

= 0 TX i  ic 

TX i  ic 

Where 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

as calculated in "Service Area Calculation" on page 645. S TX  ic  i

is the best server coverage area of the cell Condition

TXi(ic) where the given condition is true.

© Forsk 2010

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Technical Reference Guide TX i  ic 

TX j  jc 

C DLRS is the received downlink reference signal level from the cell TXi(ic). C Max from the cell TXj(jc) calculated using the Max Power defined for this cell.

TX i  ic  n DLRS

is the received maximum signal level

is the downlink noise for the cell TXi(ic)

as calculated in "Noise Calculation (DL)" on page 623. M Quality is the quality margin used for the interference matrices TX i  ic 

calculation. And, f ACS

TX i  ic  – TX j  jc 

In words,  IM

is the adjacent channel suppression factor defined for the frequency band of the cell TXi(ic). is equivalent to a probability of interference calculated by taking the ratio of the interfered surface

area to the total surface area of a cell. Two interference probabilities are calculated for each interfered-interfering cell pair, i.e., for co-channel and adjacent channel interference. TX i  ic  – TX j  jc 

 Dis tan ce

is calculated by the physical cell ID allocation algorithm as follows:

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

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 automatic allocation dialogue, and D cell TXj(jc) calculated as follows: D D

TX i  ic  – TX j  jc  TX i  ic  – TX j  jc 

joining 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

  1 + x   cos    – cos    – 2  

is weighted according to the orientations of the TBA and its related cell with respect to the straight line TX i  ic  – TX j  jc 

is the distance between the two cells considering any offsets with respect to the site locations. TX i  ic  – TX j  jc 

x is set to 15 % so that the maximum variation in D due to the azimuths does not exceed 60 %.  and  are calculated from the azimuths of the two cells as shown in Figure 10.8 on page 670.

Figure 10.8Weighted 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 10.9 on page 670. 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 10.9Importance Based on Distance Relation

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© Forsk 2010

Chapter 10: LTE Networks 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 

  Total

The quality reduction factor is a measure of the cost of an individual relation. The total cost of the current physical cell ID allocation 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 allocation 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 

10.4.4.3

Automatic Allocation Algorithm The automatic physical cell ID allocation algorithm is an iterative algorithm which: • • •

© Forsk 2010

Calculates the cost (as described above) of the current physical cell ID allocation, Allocates new physical cell IDs to cells in order to reduce the costs, and calculates the cost again, Memorises the different allocation plans in order to determine the best allocation, i.e., which provides the lowest total cost.

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© Forsk 2010

Chapter 11 Repeaters and Remote Antennas

Chapter 11: Repeaters and Remote Antennas

11

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 re-transmitting 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 675). 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 683). 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.

11.1

UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE Documents

11.1.1

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 11.1 on page 676) is calculated as follows: R

D

R – Mi

R

C DL  ic  = P DL  ic  + G Total – DL – L Path – M Shadowing – L Indoor + G

Mi

–L

Mi

Mi

Mi

– L Ant – L Body

Note: •

If a pixel/mobile Mi receives signals from the donor D and its repeater R, the total signal strength D

R

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 11.1 on page 676) is calculated as follows: Mi

Mi

R

R – Mi

C UL = P UL + G Total – UL – L Path – M Shadowing – L Indoor + G

Mi

–L

Mi

Mi

Mi

– L Ant – L Body

Here: 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.

•

G Total – DL is the total downlink gain, user-defined or calculated as explained in "Downlink Total Gain Calculation"

Mi R

on page 677. •

R

G Total – UL is the total uplink gain, user-defined or calculated as explained in "Uplink Total Gain Calculation" on page 678.

•

R – Mi

L Path is the path loss (dB) calculated as follows: R – Mi

R

L Path = L Model + L Ant , with:

•

© Forsk 2010

-

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.

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L Indoor is the indoor loss.

•

G

Mi

Mi

•

L

•

Mi L Ant

is the terminal antenna gain for the pixel/mobile Mi. is the terminal loss for the pixel/mobile Mi. is the terminal antenna attenuation (from antenna patterns) calculated for the pixel/mobile Mi (available in

WiMAX and LTE only). Note: •

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 calculating Mi

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. Note: •

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.

Figure 11.1: UMTS, CDMA2000, TD-SCDMA, WiMAX, and LTE: Signal Level Calculation

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11.1.2

Downlink Total Gain Calculation The downlink 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 – DL = – L Total – DL + G Ant – L Model + G Donor – Ant – L Donor

RX – Feeder

R

R

+ G Amp – LCov

TX – Feeder

R

+ G Cov – Ant

Figure 11.2: Downlink Total Gain: Over-the-Air Repeaters 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.

•

L Donor

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. Note: •

Secondary antennas are fully supported in the evaluation of the repeater gains.

Microwave Link Repeaters D–R

R

R

R G Total – DL = – L MW + G Amp – LCov

R

TX – Feeder

+ G Cov – Ant

Figure 11.3: Downlink Total Gain: Microwave Link Repeaters

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Technical Reference Guide 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

R G Total – DL = – L Fibre + G Amp – LCov

TX – Feeder

+ G Cov – Ant

Figure 11.4: 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 – DL  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 – DL is the total downlink gain, user-defined or calculated as explained in "Downlink Total Gain Calculation" on page 677. R

•

P Max is the maximum downlink power allowed by the equipment.

•

LCov

R

are the coverage-side transmission feeder losses for the repeater or remote antenna R.

TX – Feeder

•

11.1.3

R

G Cov – Ant is the gain of the coverage-side antenna used at the repeater or remote antenna R.

Uplink Total Gain Calculation The uplink total gain is calculated from the repeater or remote antenna reference point ( ) to the donor transmitter reference point ( ) as follows:

Over-the-Air Repeaters D

D

D–R

R

R

R G Total – UL = – L Total – UL + G Ant – L Model + G Donor – Ant – L Donor

TX – Feeder

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R

R

+ G Amp – L Cov

RX – Feeder

R

+ G Cov – Ant

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Figure 11.5: Uplink Total Gain: Over-the-Air Repeaters Here: D

•

L Total – UL are the total uplink 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.

•

L Donor

R

are the donor-side transmission feeder losses for the repeater or remote antenna R.

TX – Feeder R

•

G Amp is the amplifier gain of the repeater R. For remote antennas, this is 0.

•

L Cov

R

are the coverage-side reception feeder losses for the repeater or remote antenna R.

RX – Feeder

•

R

G Cov – Ant is the gain of the coverage-side antenna used at the repeater or remote antenna R. Note: •

Secondary antennas are fully supported in the evaluation of the repeater gains.

Microwave Link Repeaters D–R

R

R

R G Total – UL = – L MW + G Amp – L Cov

R

RX – Feeder

+ G Cov – Ant

Figure 11.6: Uplink Total Gain: Microwave Link Repeaters Here: 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.

•

L Cov

•

© Forsk 2010

D–R

•

R

R

RX – Feeder R G Cov – Ant is

are the coverage-side reception feeder losses for the repeater or remote antenna R. the gain of the coverage-side antenna used at the repeater or remote antenna R.

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Optical Fibre Link Repeaters and Remote Antennas D–R

R

R

R

R G Total – UL = – L Fibre + G Amp – L Cov

RX – Feeder

+ G Cov – Ant

Figure 11.7: Uplink Total Gain: Optical Fibre Link Repeaters and 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.

•

L Cov

R

R

are the coverage-side reception feeder losses for the repeater or remote antenna R.

RX – Feeder

•

11.1.4

R

G Cov – Ant is the gain of the coverage-side antenna used at the repeater or remote antenna R.

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 127.

11.1.5

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.

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.

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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 – DL  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 – DL is the output downlink 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 – DL D–R R R D P Rec  ic  = P Rec  ic  + P Rec  ic  = P Pilot  ic    -------------------------------------------------- + ------------------------- D – Mi R – Mi   LD  L  L Path  Total – DL 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 – DL D D L Total – DL  P Pilot  ic    --------------------------------------------------- + -------------------------- D – Mi R – Mi   LD L Path  Total – DL  L Path  Hence, Txd

G ant L total = ----------------------------------------------------------------------------------------------------------------------------------Txd Rpk  G ant G total – Air – DL Txd L total – DL   ------------------------------------------------------- + ------------------------------------ Txd – Rx Rpk – Rx   L Txd   L path total – DL  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 R

G Total – DL 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 

© Forsk 2010

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D

G Ant G Ant - = -------------------------------------------------------L Total = ------------------------------------------------------------------R R R G Total – DL  L Total – DL  D  G Total – DL  ------------------------------------------------------- L Total – DL   ------------------------- – Mi R – Mi   LR  L Path 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: C W E -----b- = ----  ---- 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 data rate 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 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  -  -------------------------------------------Mi  LD  Total – UL  L Total

And, D

N 0 = NF  K  T  W Where, NF

D

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

KTW

11.2

GSM Documents

11.2.1

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 11.8 on page 684) is calculated as follows:

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R – Mi

R

C DL  tt  = EIRPDL  tt  – P  tt  – L Path – M Shadowing – L Indoor + G

Mi

–L

Mi

Note: If a pixel/mobile Mi receives signals from the donor D and its repeater R, the total signal strength

•

D

R

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 684. 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

•

L

Mi

Mi

is the terminal antenna gain for the pixel/mobile Mi. is the terminal loss for the pixel/mobile Mi.

s Figure 11.8: GSM: Signal Level Calculation

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11.2.2

EIRP Calculation The EIRP of a repeater or remote antenna R is calculated at the repeater or remote antenna reference point ( ) w. r. t. D

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 – L Donor

RX – Feeder

R

R

+ G Amp – LCov

TX – Feeder

R

+ G Cov – Ant

Figure 11.9: EIRP: Over-the-Air Repeaters Here: D

•

P DL is the downlink transmission power of the donor 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

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.

•

L Donor

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. Note: •

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 11.10: Downlink Total Gain: Microwave Link Repeaters

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•

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

Figure 11.11: 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.

11.3

Donor-side Parameter Calculations

11.3.1

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.

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Figure 11.12: Angle from North (Azimuth)

11.3.2

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.

Figure 11.13: 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 11.14Tilt 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:

686

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.

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version 2.8.3 AT283_TRG_E2 6 December 2010

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