Nokia LTE Monitoring and Administrating
Short Description
Nokia LTE monitoring & Administrating...
Description
Nokia Networks
LTE Radio Access, Rel. FDD-LTE 15A, Operating Documentation, Issue 02 Monitoring and Measuring System in LTE RAN DN0958759 Issue 04 Approval Date 2014-11-21
Monitoring and Measuring System in LTE RAN
The information in this document applies solely to the hardware/software product ("Product") specified herein, and only as specified herein. This document is intended for use by Nokia Solutions and Networks' customers ("You") only, and it may not be used except for the purposes defined in the agreement between You and Nokia Solutions and Networks ("Agreement") under which this document is distributed. No part of this document may be used, copied, reproduced, modified or transmitted in any form or means without the prior written permission of Nokia Solutions and Networks. If you have not entered into an Agreement applicable to the Product, or if that Agreement has expired or has been terminated, You may not use this document in any manner and You are obliged to return it to Nokia Solutions and Networks and destroy or delete any copies thereof. The document has been prepared to be used by professional and properly trained personnel, and You assume full responsibility when using it. Nokia Solutions and Networks welcome Your comments as part of the process of continuous development and improvement of the documentation. This document and its contents are provided as a convenience to You. Any information or statements concerning the suitability, capacity, fitness for purpose or performance of the Product are given solely on an "as is" and "as available" basis in this document, and Nokia Solutions and Networks reserves the right to change any such information and statements without notice. Nokia Solutions and Networks has made all reasonable efforts to ensure that the content of this document is adequate and free of material errors and omissions, and Nokia Solutions and Networks will correct errors that You identify in this document. But, Nokia Solutions and Networks' total liability for any errors in the document is strictly limited to the correction of such error(s). Nokia Solutions and Networks does not warrant that the use of the software in the Product will be uninterrupted or error-free. NO WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY OF AVAILABILITY, ACCURACY, RELIABILITY, TITLE, NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, IS MADE IN RELATION TO THE CONTENT OF THIS DOCUMENT. IN NO EVENT WILL NOKIA SOLUTIONS AND NETWORKS BE LIABLE FOR ANY DAMAGES, INCLUDING BUT NOT LIMITED TO SPECIAL, DIRECT, INDIRECT, INCIDENTAL OR CONSEQUENTIAL OR ANY LOSSES, SUCH AS BUT NOT LIMITED TO LOSS OF PROFIT, REVENUE, BUSINESS INTERRUPTION, BUSINESS OPPORTUNITY OR DATA THAT MAY ARISE FROM THE USE OF THIS DOCUMENT OR THE INFORMATION IN IT, EVEN IN THE CASE OF ERRORS IN OR OMISSIONS FROM THIS DOCUMENT OR ITS CONTENT. This document is Nokia Solutions and Networks' proprietary and confidential information, which may not be distributed or disclosed to any third parties without the prior written consent of Nokia Solutions and Networks. Nokia is a registered trademark of Nokia Corporation. Other product names mentioned in this document may be trademarks of their respective owners, and they are mentioned for identification purposes only. Copyright © 2015 Nokia Solutions and Networks. All rights reserved.
Important Notice on Product Safety This product may present safety risks due to laser, electricity, heat, and other sources of danger. Only trained and qualified personnel may install, operate, maintain or otherwise handle this product and only after having carefully read the safety information applicable to this product. The safety information is provided in the Safety Information section in the "Legal, Safety and Environmental Information" part of this document or documentation set. Nokia Solutions and Networks is continually striving to reduce the adverse environmental effects of its products and services. We would like to encourage you as our customers and users to join us in working towards a cleaner, safer environment. Please recycle product packaging and follow the recommendations for power use and proper disposal of our products and their components. If you should have questions regarding our Environmental Policy or any of the environmental services we offer, please contact us at Nokia Solutions and Networks for any additional information.
2
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Table of Contents This document has 34 pages Summary of changes..................................................................... 7 1
Introduction to monitoring and measuring system in LTE RAN......8
2
Architecture of the monitoring and measuring system in LTE RAN. 10
3
3.2
Functional description for monitoring and measuring system in LTE RAN.......................................................................................11 General concept........................................................................... 11 Design approach.......................................................................... 11
3.2.1
Versioning.................................................................................... 12
3.2.2 3.2.3
Triggers........................................................................................ 12
3.1
3.2.4
Cell approach............................................................................... 12 Format.......................................................................................... 12
3.2.5
KPIs..............................................................................................12
3.2.6 3.3
Fault causes.................................................................................13
3.3.1
Performance monitoring areas.....................................................13 Quality of Service (QoS).............................................................. 13
3.3.2
Capacity monitoring..................................................................... 13
3.3.3
Troubleshooting............................................................................15
3.3.4 3.3.5
Traffic model verification (traffic profile)........................................16 Network planning......................................................................... 16
3.3.6
Network optimization....................................................................17
3.3.7 3.3.8
Cost-optimized network topology design..................................... 17
3.3.9
Improvements of grade of services and quality of services......... 17 Acceptance tests/verification tests............................................... 18
3.3.10
Benchmarking.............................................................................. 18
3.3.11 3.3.12
Reliability......................................................................................18
3.4
Network operation........................................................................ 19 PMO measurement communities.................................................19
3.5
Mapping of PMO functional areas to PMO data...........................20
3.6
Mapping between procedures and measurement areas..............22
4
4.1.1
Operating tasks related to monitoring and measuring system in LTE RAN...................................................................................... 25 PMO operational procedures....................................................... 25 Network supervision.....................................................................25
4.1.2
Network analysis.......................................................................... 25
4.1.3 4.1.4
Traffic analysis............................................................................. 27
4.1
Issue: 04
4.1.5
Troubleshooting............................................................................27 UE validation and interception..................................................... 29
4.1.6
PMO administration......................................................................29
DN0958759
3
Monitoring and Measuring System in LTE RAN
4.2 4.2.1
PMO measurement procedures................................................... 30 Categories....................................................................................30
4.2.2
Procedure areas...........................................................................30
4.2.3 4.3
Technology Specific Performance Indicator Groups (PI Groups) .... 31 eNB monitoring procedures......................................................... 31
4.3.1
Performance supervision of the LTE RNL and TNL..................... 31
4.3.1.1
Monitoring capacity license/number of active users per BTS...... 32
4.3.2
Localization of sources of insufficient performance, capacity, or quality...........................................................................................32 Troubleshooting and network optimization at the eNB with the performance data......................................................................... 33
4.3.3
4
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
List of Figures
Issue: 04
Figure 1
Architecture of PMO operational concept...........................................10
Figure 2
Performance monitoring design concept............................................ 11
Figure 3
Blocking time...................................................................................... 15
Figure 4
PMO measurement communities....................................................... 20
Figure 5
PMO functional areas......................................................................... 21
DN0958759
5
Monitoring and Measuring System in LTE RAN
List of Tables
6
Table 1
Main functions of performance monitoring........................................... 8
Table 2
Mapping..............................................................................................22
Table 3
Network supervision........................................................................... 25
Table 4
Network analysis................................................................................ 26
Table 5
Traffic analysis....................................................................................27
Table 6
Troubleshooting.................................................................................. 28
Table 7
UE validation and interception............................................................29
Table 8
PMO administration............................................................................ 30
Table 9
Performance supervision of the LTE RNL and TNL........................... 31
Table 10
Localization of sources of insufficient performance, capacity, or quality ............................................................................................................33
Table 11
Troubleshooting and network optimization at the eNB with performance data............................................................................... 33
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Summary of changes
Summary of changes Changes between issues 03 (2012-08-02, RL40) and 04 (2014-11-21, RL70) Introduction to monitoring and measuring system in LTE RAN (1): Updated Main functions of performance monitoring to identify the LTE Radio Access exclusive data KPIs (3.2.5): Added reference for Flexi Zone end to end KPIs document is added Quality of Service (QOS) (3.3.1): Updated Examples of relevant measurement types and Related KPI groups to identify the LTE Radio Access exclusive data Troubleshooting (3.3.3): Updated Examples of relevant measurement types and Related KPI groups to identify the LTE Radio Access exclusive data Cost-optimized network topology design supporting MDT (minimization of drive test) (3.3.7): Added reference for the LTE953: MDT (minimization of drive test) feature document
Changes between issues 02A (2011-03-24, RL20) and 03 (2012-08-02, RL40) Introduction to monitoring and measuring system in LTE RAN (1): Updated Main functions of performance monitoring to identify LTE Radio Access exclusive data
Changes between issues 02 (2010-12-15, RL20) and 02A (2011-03-24, RL20) Introduction to monitoring and measuring system in LTE RAN (1): References to LTE and NetAct documentation added. Operating tasks related to monitoring and measuring system in LTE RAN (4): section eNB monitoring procedures added.
Issue: 04
DN0958759
7
Introduction to monitoring and measuring system in LTE RAN
Monitoring and Measuring System in LTE RAN
1 Introduction to monitoring and measuring system in LTE RAN This document explains the generic design concept of the Performance Monitoring (PMO) system for LTE Radio Access Network (RAN). It mainly describes the process of defining and designing performance measurements, what is defined in 3GPP, and what can be defined with common rules valid for all radio technologies. In the life cycle of a mobile communication network, there are important reasons to carry out performance measurement for different applications. The main goal of the network operator is to achieve profit. Therefore, it is very essential to have many subscribers, good network quality, and low costs. The usage of performance measurement supports many tasks and processes under these aspects. With the help of performance monitoring, it is possible to collect information on:
• • • • • •
networks traffic intensity traffic distribution (if it is spread out evenly, or concentrated in certain spots) events happening in certain spots of the network (and how often do they occur) planning efficiency (that is, if the instructions are fulfilled, or when any additional changes are needed ) locations where frequent failures are reported subscriber behavior (if it corresponds with the assumed model)
The operator is able to supervise the performance, capacity and quality of the network and increase the subscriber's satisfaction. Performance monitoring is mainly used for:
• • • • • • •
supervision of quality, capacity and performance verification of network planning and optimization forecasts for future network planning error detection and correction troubleshooting implementing services and features customer behavior identification
Table 1: Main functions of performance monitoring shows how performance monitoring can be subdivided into functions and sub-functions. Table 1
Function
Measuring
8
Main functions of performance monitoring
Sub-function
Tools
Performance measurements:
NetAct Administration of Measurements
• •
counters counter-based KPIs
BTS Site Manager: PM function
Threshold-based PM alarms
NetAct Thresholder and Profiler
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Table 1
Function
Tracing
Introduction to monitoring and measuring system in LTE RAN
Main functions of performance monitoring (Cont.)
Sub-function
Tools
Subscriber and equipment trace
NetAct TraceViewer
Cell traffic trace
NetAct TraceViewer
Trace-based, real-time monitoring
Traffica
Sub-function and tool exclusive for LTE Radio Access External interface trace
3rd party analyzer
The Measuring function means collecting and analyzing various performance data. These data are gathered in the form of counters/registers updated when a specified network event occurs. Counters are grouped into administrative entities called measurements, which represent a certain aspect of the performance area. The counter values are viewed locally by using the BTS Performance Monitoring application in the BTS Site Manager or globally by using the NetAct Reporting tools. For information on the measurement administration, collection, storage, and so on, see Performance Management. For information on the performance data content, see LTE Performance Measurements. Counters are the building blocks for key performance indicators (KPIs). A KPI is basically a formula that consists of one or several counters. These formulas are calculated at NetAct level. The KPIs are used to create top-level reports, which indicate the network performance. For information on the KPI content, see Specifications of LTE RAN Key Performance Indicators. With the NetAct Thresholder and Profiler application, it is possible to define thresholds based on collected counters/KPIs. When this threshold is exceeded, an alarm is raised. For details, see Using NetAct Applications (Report) and Reporter and Performance Management Principles in NetAct operating documentation. The Tracing function in practice means collecting and analyzing trace records that are created for certain calls within a cell or for certain subscribers/equipment. The traced data can be viewed using the NetAct TraceViewer application. For information on the tracing area, see Tracing LTE RAN System. For information on the NetAct TraceViewer application, see Tracing Principles and Tracing Subscribers and Equipment documents in the NetAct documentation. With the introduction of LTE1340: Trace-based Real Time Monitoring feature, the data collected using the cell trace feature can be forwarded to Traffica for visualization. Traffica is a real-time traffic monitoring and analyzing tool that allows the operator to immediately detect network and service failures. Data forwarded to Traffica can be presented as a real time graph (using the Traffica Views client). It can also be stored for further analysis. For information on Traffica, see the Traffica documentation.
Issue: 04
DN0958759
9
Architecture of the monitoring and measuring system in LTE RAN
Monitoring and Measuring System in LTE RAN
2 Architecture of the monitoring and measuring system in LTE RAN Nokia provides a complete PMO system with a large number of functions and performance measurements. Therefore, the operator must be guided on how to use this performance monitoring system. Mainly for that reason, the PMO operational concept has been defined with three levels of operation for supervision of a mobile radio network. Figure 1: Architecture of PMO operational concept shows the three level concept. Figure 1
Architecture of PMO operational concept
L Permanent supervision of performance, quality, and capacity E with most important KPIs and QoS alarms to detect weak V points in the network (technical report, worst cell list) E L Permanent operation of main measurements 1
L Analysis of detected problems, such as radio quality, call processing E features, with detailed measurements V (root cause analysis) E L Analysis of many detailed PM counters on request 2
L E V E L 3
Deeper analysis of detected problems and features for network optimization and troubleshooting with other PM features (cell trace, subscriber and equipment trace) and external equipment (K1297, test drive, and so on)
To evaluate the network performance and check if a set of defined Quality of Service (QoS) goals are fulfilled, the network and performance data collected must be monitored from many elements. The QoS requirements define, for example, the measurements/KPIs that should be monitored with the PMO tools and added to particular reports. To help find and eliminate problems more quickly, it is important to precisely select the items to be monitored and filter only the relevant information.
10
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Functional description for monitoring and measuring system in LTE RAN
3 Functional description for monitoring and measuring system in LTE RAN 3.1 General concept The design of performance measurements is mainly based on:
• •
top-down approach that defines the necessary KPIs based on procedures. The KPIs consists several elementary counters that are provided by different subsystems of the eNB. PMO operational concept, which is already described in the Architecture of the Monitoring and Measuring System in LTE RAN.
Starting with procedures, the intention is to focus on the main radio procedures, which have to be supervised by each operator to guarantee that the LTE radio access network works properly. KPIs can be used to monitor and optimize the system performance. Counters are used to proactively identify network abnormalities and possible configuration faults. Measurement results are the input for network planning and optimization tasks. Figure 2
Performance monitoring design concept PM Customer requirements / Use cases
Standardization requirements (3GPP)
- Network operation - Network planning - Network optimization
- Customer care - Management - Marketing
Call processing feature requirements
(Key) Performance Indicators (KPI) Common Specific
GERAN Formulas
UTRAN Formulas
LTE Formulas
GERAN Counters
UTRAN Counters
LTE Counters Requirements and further implementation
3.2 Design approach The definition of performance measurements follows a general design approach. This approach is valid for all RAN technologies.
Issue: 04
DN0958759
11
Functional description for monitoring and measuring system in LTE RAN
Monitoring and Measuring System in LTE RAN
3.2.1 Versioning The versioning principles are as follows:
• • •
Backward compatibility is ensured so that the impact on PM evaluation tools (NetAct) can be reduced. Defined PM counters must not be deleted in the subsequent releases. (Exception: the case where a certain functionality is no longer supported). PM counters are designed to fit to licensing requirements.
3.2.2 Triggers The (n-1) out of n approach (as defined in 3GPP TS 32.404) is used to avoid redundancy in the measurements. The missing nth value is calculated by post-processing.
3.2.3 Cell approach The proposed cell approaches are:
• • •
The usual events are counted for the source cell, for example, outgoing handovers. For neighbor cell relations, it is counted for a pair of source cell-target object (target object can be a cell or target NE). If needed, it can also be counted for the target cell, for example, incoming handovers.
3.2.4 Format The formatting rules are:
• • •
The percentage value is calculated at NetAct level. The definition of percent values are omitted at NE. Counters representing percentage (average) values are calculated and reported at the NE only when the denominator is not constant (for example, the CPU Load). Percentage is done in the NE for implementation or performance reasons. Percentage values are reported in real percentage (for example 55.22%).
3.2.5 KPIs KPI design rules:
• •
KPIs are calculated at NetAct level based on raw counters. The average measurements are calculated at the NetAct level and at Traffica if the LTE1053: Real-time KPI-monitoring with Traffica feature is used. This allows to present a wider perspective from the network point of view. The detailed measurements are calculated on a particular NE-level. This rule applies for example to RRC connection setup success and Handover success rates.
For more details on KPI definitions and procedures, see Flexi Zone end to end KPIs document.
12
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Functional description for monitoring and measuring system in LTE RAN
3.2.6 Fault causes Rules for fault monitoring:
•
The following types of counters are provided for different types of events (for example RRC connections, handovers): -
number of attempts
-
number of successful attempts number of failed attempts
-
These counters are useful for NetAct and PM evaluation tools.
•
For most important failure causes additional 'per cause' counters are provided. Other failure causes are calculated through KPIs.
3.3 Performance monitoring areas 3.3.1 Quality of Service (QoS) Network operators use performance measurements to obtain statements about the quality of service of the network. To improve the performance, it is even necessary to obtain QoS data provided by each cell and to find the worst ones. If a predefined quality threshold is exceeded, the operator uses the results of the measurements to trigger further investigations and actions. For this purpose, basic procedures on a mobile application level are observed in terms of their success or failure. In this sense, the most important procedures are procedures that are observed from the subscribers and used as basis for customer satisfaction. Monitoring of quality is necessary, as perceived by the subscribers, with regards to accessibility, retain ability and quality of the connection. Additional aspects for subscriber perception are the call setup time and the throughput rate in case of packet services. Examples of relevant measurement types:
• • •
Measurement: S1AP (M8000) Measurement: EPS Bearer Measurement (M8006) Measurement: Radio Bearer (M8007) for LTE Radio Access only • Measurement: RRC (M8008)
Related KPI groups:
• • • •
E-UTRAN E-RAB related KPIs E-UTRAN S1AP related KPIs E-UTRAN Radio Bearer related KPIs for LTE Radio Access only E-UTRAN RRC signaling related KPIs
3.3.2 Capacity monitoring Performance measurements are said to monitor the utilization of provided resources and capacity within the network (capacity monitoring) on a regular basis. The goal of capacity monitoring is to detect potential bottlenecks within the network in time. In this sense, the
Issue: 04
DN0958759
13
Functional description for monitoring and measuring system in LTE RAN
Monitoring and Measuring System in LTE RAN
most important procedures are procedures that are observed from the subscribers and used as basis for customer satisfaction. For example adaptation of network configuration or HW upgrade. Typical targets to monitor the network are:
• • •
load on links, connections between network elements, and their resources load on potential bottlenecks amount of traffic and the load during the busy hour
Examples of relevant measurement types:
• • • •
Measurement: Cell Load (M8001) Measurement: Transport Load (M8004) Measurement: Cell Resource (M8011) Measurement: Cell Throughput (M8012) • Measurement: eNB Load (M8018)
Related KPI group: E-UTRAN Capacity related KPIs. The basic intention of capacity monitoring is to provide sufficient information that allows network operators to act before resources get exhausted and before Grade of Service (GoS) to mobile users can no longer be maintained (proactive approach). In case of failures because of lack of resources or capacity, appropriate performance measurement counters allow the identification of relevant bottlenecks. Since appropriate actions are triggered after the GoS has been degraded, this is a reactive approach. Performance measurements are regularly used to monitor the load and the quality of the mobile network. As a result, network operation actions are executed depending on the result of the monitoring process. The typical targets of monitoring the network are:
• • • •
utilization on TNL connections between network elements load potential bottlenecks within the network elements amount of traffic and the load during busy hour usage of resources of the network element
In E-UTRAN, the following capacities are monitored:
• • • •
equipment capacity radio network capacity transport layer capacity resource capacity
The basic approaches used for capacity element measurement are proactive and reactive. Methodology for capacity monitoring (proactive and reactive) The diagram below (refer to Figure 3: Blocking time) demonstrates the concept of the general methodology to monitor the trend of a key capacity element in order to detect a suitable time for starting a network expansion activity. The following steps are required to predict the time of the expansion: 1. Choose the key capacity element that appears or expects to form a primary bottleneck of system resource, causes service blocking or quality degradation. 2. Determine the limit against blocking, which is the value of the key capacity element at which service blocking or quality degradation is experienced. 3. Monitor the actual trend of the key capacity element at sites during daily operation.
14
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Functional description for monitoring and measuring system in LTE RAN
4. Estimate the time to reach the limit against blocking using Figure 3: Blocking time. 5. Estimate the time required for the expansion activity and the threshold for expansion by considering the implementation plan of the system expansion (for example stock status and availability of spare parts, lead-time for delivery of parts, installation & testing period etc.). Figure 3
Blocking time
Key capacity element
Re-active approch: service blocking/degradation (call block/drop, setup failure, quality drop)
Pro-active approch: actual service/resource usage under expected condition
Time
3.3.3 Troubleshooting Network operators monitor the quality of their networks in different ways, such as the use of performance measurements to obtain statements about the QoS and the GoS of the network (refer to ITU Grade of Service concept of ITU E.720). This means that the basic procedures on the mobile application level are monitored in terms of success or failure of these scenarios. Typical examples of these are call success rates, call drop rates, or handover success rates. Once the failure (or failure ratio) exceeds a defined threshold, the operator uses the results of the measurements to trigger further analysis. In addition, performance measurement counters provide more detailed information on the failure, such as indications about the specific error cause or an indication about the network element that caused the failure (fault localization). For this purpose, the provided performance measurement counters are based on a suitable set of failure causes. Examples of relevant measurement types:
• • •
Measurement: S1AP (M8000) Measurement: EPS Bearer Measurement (M8006) Measurement: Radio Bearer (M8007) for LTE Radio Access only • Measurement: RRC (M8008)
• • • •
Measurement: LTE X2AP (M8022) Measurement: Intra eNB Handover (M8009) Measurement: Inter eNB Handover (M8014) Measurement: LTE Handover (M8021)
Related KPI groups:
Issue: 04
DN0958759
15
Functional description for monitoring and measuring system in LTE RAN
• • • • •
Monitoring and Measuring System in LTE RAN
E-UTRAN E-RAB related KPIs E-UTRAN S1AP related KPIs E-UTRAN Radio Bearer related KPIs for LTE Radio Access only E-UTRAN RRC signaling related KPIs E-UTRAN Handover related KPIs
In general, it is assumed that performance measurements are not enough means to support detailed fault detection or detailed fault localization. This task is due for further investigation by the technical service personnel using other means than performance measurements (for example: tracer, external monitoring equipment, error notebook information, and so on).
3.3.4 Traffic model verification (traffic profile) Performance measurements are used to obtain the traffic profile of a real network. For this purpose, the measurements for the elementary mobile network procedures, during busy hours per subscriber level, are provided. For the network operator, the measured real traffic profile is used to verify the assumptions for its traffic model. The result of the traffic profile analysis influences a variety of activities on the network operator side, such as the network planning process, the definition of charging models, or the instruction of new services. In addition, the operators can observe how the subscriber behavior varies over time. For marketing purposes, the traffic profile is used to verify the forecasts on a subscriber base. For an equipment vendor, real traffic models can be used as input for the network element planning, in particular, for developing a strategic performance roadmap that meets network operator requirements.
3.3.5 Network planning During the planning process for the individual network element, the measured traffic demand/traffic model is used to verify created assumptions. Since network elements cover different geographical areas, network related measurements can be provided by the network elements on different levels (for example cell, controller, location area). The derived traffic model serves several verification purposes. For the network operator, the real traffic demand is used to verify the assumptions made during the network planning process. The operators also observe how the subscriber behavior changes over the time. For an equipment vendor, real traffic models are used as input for the network element planning to develop a strategic performance roadmap that meets network operator requirements. Network dimensioning, planning, and configuration of the network element and the surrounding network Performance measurements are important input for the planning process of single network elements in an operator's network. Two aspects influence the planning process and its activities of dimensioning and configuring the network element.
16
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
•
•
Functional description for monitoring and measuring system in LTE RAN
One aspect is that new traffic figures are considered as derived from traffic forecast or traffic roadmaps. Performance measurements provide the necessary information for the next planning steps in existing networks and network elements, and on how to dimension and configure the network element and their interfaces to the surrounding network. Performance measurements that serve this purpose are basic load measurements, grade of service measurement, and measurements that verify the network configuration. Another aspect is the reconfiguration of the network element when new features are introduced, new software or hardware has been installed, or new or modified redundancy schemes are applied. This can be done together or independently from the normal network planning process as described above. Basic load measurement s and grade of service measurements are means to evaluate the new network eleme nt configuration.
3.3.6 Network optimization Network optimization is composed of two parts: the improvement of the GoS and QoS and the introduction of a cost-optimized network design.
3.3.7 Cost-optimized network topology design This procedure comprises the verification and modification of the network design or the network plan. The goal is to reduce operational and capital expenditures by maintaining or even improving the same current GoS. Usually, an initial network design is done first. Later on, this initial design is subjected to modifications with the goal of finding an optimal solution, (for example trade-off) for CAPEX and OPEX. The entire process can be described as a loop to optimize the current network design and network plan. The final result of each optimization loop is influenced by several parameters. One type of input parameters is the current traffic profile from the current network, which is obtained by analyzing appropriate performance measurements. Another input is the traffic forecast for the existing network. Traffic forecast includes the number of subscribers served by the network in the upcoming period of time, the traffic per subscriber in that timeframe, and the planned network coverage of a given geographical area. In addition, marketing forecasts and expectations will be considered and used as input parameters for this process. Similar to the previous section, performance measurements are used for verification of the implemented improvements by analyzing the same performance measurements beforehand and afterwards. For more details on MDT (minimization drive test), see LTE953: MDT (minimization of drive test) feature.
3.3.8 Improvements of grade of services and quality of services One of the major goals of network optimization is the improvement of the GoS and QoS without extending the network or single network element. Thus, network optimization is focused on:
•
Issue: 04
malfunctions and failures within the network
DN0958759
17
Functional description for monitoring and measuring system in LTE RAN
• • •
Monitoring and Measuring System in LTE RAN
maintaining and improving mobile user satisfaction related to GoS and QoS of offered services improving network quality for operators in competition meeting requirements of official regulations
An appropriate performance measurement is provided to obtain the current status of QoS and GoS of the relevant network scenarios and procedures before optimization activities start. Implemented improvements are verified by analyzing the same performance measurements afterwards. A typical example for an optimization task in the UTRAN is the analysis of performance measurement data provided by each cell to find the worst ones. In case a predefined quality threshold is exceeded, the operator uses the results of the measurements to trigger further investigations and actions.
3.3.9 Acceptance tests/verification tests Acceptance tests are conducted to verify contractually agreed performance targets. This is the case when a vendor has to approve performance and network quality values under field conditions after the network rollout or the network upgrade. Depending on the type of measurement during acceptance, PM counters are used to obtain the requested measurement result. Appropriate performance measurement counters provide the necessary information by collecting data for the supported measurement objects and scenarios.
3.3.10 Benchmarking Benchmarking of the supplied network elements and the network itself is the comparison used by different vendors with the same measurement methodology. Performance measurements serve the purpose of benchmarking by providing measurement data of comparable network scenarios and procedures. In order to execute performance measurements for benchmarking purposes, the following requirements are met: First, the measurements on equipment of different vendors are implemented by using the same trigger points for the same scenarios. Ideally, the measurements follow the definitions from the standardization bodies. Second, the performance measurements must be executed in similar network environments. This means that comparing different equipment requires an equivalent to a traffic environment (for example local traffic profile) with equivalent network configurations. Consequently, standardized or commonly used performance measurements for the most important scenarios within the RAN are supported.
3.3.11 Reliability Network operators must assure reliability of their network elements to provide stable communication services for their customers. Reliability is typically represented by the mean time between failure (MTBF) and the mean time to repair (MTTR) of the network elements. However, current implementation and 3GPP TS 32.403 does not address reliability as a part of performance management objectives. Nokia recognizes that reliability is monitored in the context of fault management (FM) instead of performance management (PM).
18
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Functional description for monitoring and measuring system in LTE RAN
3.3.12 Network operation Network operators use performance measurement results to keep track of the current network operating condition. If one or more QoS (KPI) values exceed the predefined thresholds, the network operator might want to diagnose the network problem that leads the QoS (KPI) degradation. Certain performance counters for failed network events per error cause are provided to diagnose the network problem and select corrective actions. Examples include counters for failed RAB establishment, failed RRC connection establishment, and radio link failures. Note that such performance counters for failed network events are not mandatory for equipment vendors to implement. To calculate the call setup success rate, it is enough to measure the call setup request counts and the successful call setup counts. This is called the (n-1) out of n approach in the 32.403 specification. Nevertheless, many network operators find it useful to diagnose network problems by analyzing performance counters of failed network events. Network problem diagnosis is further facilitated by linking the performance management failure trend with the fault management system logs.
3.4 PMO measurement communities Performance monitoring based on PM counters is one of the most important PMO functions for permanent supervision of the mobile radio network. Depending on the scope of performance measurements, network monitoring can serve a different purpose for different measurement communities, as defined by 3GPP. These measurement communities can be understood as categories of users that outlined their needs and requirements for measurements taken from their wireless telecommunication network. The most important measurement communities are as follows:
• • • • • •
Network Planning Community Network Operation Community Network Optimization Community Marketing Community Customer Care Community Management Community
The basic intention of this information model is to implicitly define a methodology and workflow for the useful performance measurement counters in the core network products. Any new requests for performance measurement counters must fit into this concept. Figure 4: PMO measurement communities shows the concept.
Issue: 04
DN0958759
19
Functional description for monitoring and measuring system in LTE RAN
Figure 4
Monitoring and Measuring System in LTE RAN
PMO measurement communities
3.5 Mapping of PMO functional areas to PMO data Mapping of PMO functional areas to PMO data is of major importance for design of the PMO system. The following PMO data types based on different characteristics are defined for the PMO functional areas. Figure 5: PMO functional areas shows the relation between PMO function and PMO data.
20
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Figure 5
Functional description for monitoring and measuring system in LTE RAN
PMO functional areas
The PMO data can be collected with reports, records and files. A PMO report
consists of several PMO records. Each report is sent separately to the NE or NetAct.
A PMO record
can contain a group of information related to one event, for example tracing IEs, PM counters.
The content of these PMO records is defined as PMO data type. Different PMO functions provide different PMO data types that can be separated into: Subscriber related records
• • •
subscriber and equipment trace records cell trace records interface trace records
Non-subscriber related records
•
Issue: 04
PM counter records
DN0958759
21
Functional description for monitoring and measuring system in LTE RAN
Monitoring and Measuring System in LTE RAN
3.6 Mapping between procedures and measurement areas In Table 2: Mapping, there are several measurement areas per procedure. The same measurement area applies to several procedures. The table defines the mapping example between the particular measurement areas and the procedures that use these measurement areas. Table 2
Mapping
Procedure
Measurement area
acceptance / verification
accessibility NE availability integrity / reliability retainability
network planning
service availability access time accessibility integrity / reliability retainability resource utilization / usage traffic distribution
traffic model verification
service availability accessibility traffic distribution
benchmarking
NE availability service availability access time accessibility integrity / reliability
22
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Table 2
Functional description for monitoring and measuring system in LTE RAN
Mapping (Cont.)
Procedure
Measurement area retainability
troubleshooting
NE availability service availability access time accessibility integrity / reliability resource utilization / usage accessibility
capacity monitoring
integrity / reliability retainability resource utilization / usage traffic distribution accessibility
O&M: monitoring of QoS
mobility integrity / reliability retainability network optimization: GoS / QoS
service availability
access time accessibility integrity / reliability retainability network optimization: optimized network design
accessibility
integrity / reliability
Issue: 04
DN0958759
23
Functional description for monitoring and measuring system in LTE RAN
Table 2
Monitoring and Measuring System in LTE RAN
Mapping (Cont.)
Procedure Measurement area retainability resource utilization traffic distribution reliability fault management network operation
24
external monitoring tool
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Operating tasks related to monitoring and measuring system in LTE RAN
4 Operating tasks related to monitoring and measuring system in LTE RAN 4.1 PMO operational procedures PMO operational procedures are activities executed by the operator to supervise the mobile network. It includes all performance management functions to collect, administer, plan, execute, store, and evaluate performance monitoring data for the following areas:
4.1.1 Network supervision Table 3: Network supervision shows procedures relevant for network supervision. Network supervision
Table 3
Procedure title
Procedure description
PM data category
Procedure trigger
Online Network Supervision (Thresholdbased PM alarms)
Permanent supervision of specific PM data to detect problems in the network (for example: anomalies, sleeping cells, high drop Rates, and so on). Notification is generated if the collected PM data exceeds the defined threshold. Operator is able to define thresholds for notification generation.
Performance, Capacity, Quality
Short-term Network Supervision
Permanent supervision of specific PM data to detect problems in the network. Short-term reporting of PM data.
Performance, Capacity, Quality
Mid/Longterm Network Supervision
Permanent supervision of specific PM data to detect weak points and performance in the network (for example: technical report, worst cell list). Mid or long-term reporting of PM data.
Evaluation Target interval group
PM function PM tool
permanent
online
Network operation
Threshold -based PM alarming at NetAct level
permanent
short-term
Network operation
Performance BTS measuremen SM PM ts Data viewer Reporte r
midterm long-term
Network operation
Performance Reporte measuremen r Global ts reporter
Performance, permanent Capacity, Quality
NetAct Reporte r (Thresh older and Profiler)
4.1.2 Network analysis Table 4: Network analysis shows procedures relevant for network analysis.
Issue: 04
DN0958759
25
Operating tasks related to monitoring and measuring system in LTE RAN
Table 4
Network analysis
Procedure title Procedure description
26
Monitoring and Measuring System in LTE RAN
PM data category
Procedure trigger
Evaluation interval
Target group
PM function PM tool
Online monitoring based on PM counter reports
Online Network Analysis
Analysis of detected Performance on demand problems in case , Capacity, threshold-based PM Quality alarm was received. Triggered by the PM alarms, the PM data of the predefined measurements are reported online.
real-time
Network operation
Short-term Network Analysis
Analysis of detected problems with detailed PM data for troubleshooting. Short-term reporting of detailed PM data.
short-term operation
Network Performance BTS SM Measuremen PM Data ts viewer Reporter
Mid/Long-term Network Analysis
Analysis of detected problems with detailed PM data for trouble shooting. Mid/long-term reporting of detailed PM data.
Performance on demand , Capacity, Quality
midterm/long Network -term operation Network optimization
Performance Reporter measuremen Optimizer ts
Network Optimization
Analysis of detected Performance on demand problems with , Capacity, detailed PM data for Quality network optimization (including fine tuning).
midterm/long Network -term operation Network optimization
Performance Reporter measuremen Optimizer ts
Deep Network Optimization
Deeper analysis of Performance on demand detected problems , Capacity, with any PM data for Quality network optimization.
midterm/long Network -term operation Network optimization
Subscriber and equipment trace/Cell trace
Reporter Optimizer Trace viewer
Radio Network Planning Verification
Checking radio coverage and using drive test before placing a BTS into operation.
Trace records
short-term and
Subscriber
Trace
Multi Vendor Benchmarking
Getting performance, capacity, and quality indications for multivendor benchmarking.
Performance , Capacity, Quality
Performance on demand , Capacity, Quality
on demand operation
Network viewer
Online PM Visualizer
equipment trace
on demand
DN0958759
long term
Management Performance Reporter Network measuremen operation t Network optimization
Issue: 04
Monitoring and Measuring System in LTE RAN
Table 4
Operating tasks related to monitoring and measuring system in LTE RAN
Network analysis (Cont.)
Procedure title Procedure description
PM data category
Procedure trigger
Evaluation interval
Target group
PM function PM tool
Acceptance and Getting performance, Verification tests capacity, quality indications, and message flows for acceptance tests and feature verification, for example before rollout.
Performance on demand Capacity Quality trace records
online short term
Network operation
Performance Reporter measuremen Trace ts viewer Subscriber and equipment trace Cell trace
4.1.3 Traffic analysis Table 5: Traffic analysis shows procedures relevant for traffic analysis. Table 5
Traffic analysis
Procedure title
Procedure description
PM data category
Procedure trigger
Traffic Localization (Hotspot detection)
Using GPS or CI/RTT data of the traced connections to determine traffic localization for dedicated areas.
Trace records on demand mid-term
Traffic Model Verification
long-term Performance, performance and Capacity capacity observation to verify the traffic model.
on demand
Evaluation interval
Target group
PM function
PM tool
short-term operation
Network viewer Network optimization Network planning
Cell Trace
Trace
mid-term long- Network term planning
Performance Reporter measurement s
4.1.4 Troubleshooting Table 6: Troubleshooting shows procedures relevant for troubleshooting.
Issue: 04
DN0958759
27
Operating tasks related to monitoring and measuring system in LTE RAN
Table 6
Troubleshooting
Procedure title
Procedure description
PM data category
Procedure trigger
Evaluation Target interval group
PM function
PM tool
Online Trouble Shooting
Deeper analysis of detected problems with any PM data for troubleshooting. Uses the trace function to get more detailed information on connection level. Both PM data and connection level information are reported online or in real time.
Performance, Capacity, Quality, Trace records
on demand
real time or online
Performanc e measureme nts
NetAct Applicatio n (Online Monitor)
Cell trace (online)
Reporter TraceView er
Deeper analysis of detected problems with any PM data and trace data for trouble shooting. shortterm/midterm reporting of PM data and connection level information.
Performance Capacity Quality trace records
Subscriber Complaint
Checking how the complaining subscriber's services are working, to get information at connection level in order to find out the reason for the complaint
trace records monitoring records
on demand
online short-term
Network operation
Subscriber and equipment trace
Trace viewer
Radio Coverage Check
Using Cell Traffic Trace without sending out the drive tester
trace records
on demand
online short-term
Network operation
Cell Trace
TraceView er
External IF Trace
Trace of at least L3 information on external interfaces to get advanced symptom data for trouble shooting
trace records
on demand
short-term
Network operation
external IF trace
3rd party tools
Short-term / midterm Trouble Shooting
28
Monitoring and Measuring System in LTE RAN
Network operation Network optimization
Subscriber and equipment trace (online)
on demand
short-term midterm
Network operation Network optimization
Performanc e measureme nts
Reporter TraceView er
Cell trace Subscriber and equipment trace
monitoring records
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Table 6
Operating tasks related to monitoring and measuring system in LTE RAN
Troubleshooting (Cont.)
Procedure title
Procedure description
PM data category
Internal IF Trace
Trace of all necessary trace records information on internal interfaces to get advanced symptom data for service activities.
Procedure trigger
Evaluation Target interval group
trace records short-term
PM function
Service (no Internal IF operability trace feature) developmen t
PM tool
Diagnosis workbenc h
4.1.5 UE validation and interception Table 7: UE validation and interception shows procedures relevant for UE validation and interception. Table 7
UE validation and interception
Procedure title
Procedure description
PM data category
User Equipment Validation
Checking how different vendor's UEs are working (for example in field testing) in the mobile network or getting detailed information on the UEs. Observation of the UE that is not working within specifications or on the grey or black EIR list.
Interception of UE
To get the user behaviors of particular subscriber, also including the location information (as alternative for lawful interception).
Procedure trigger
Evaluation interval
Target group
PM function
PM tool
trace records on demand
online shortterm
Network operation
Subscriber and equipment trace
TraceVie wer
trace records on demand
online shortterm
Network operation
Subscriber and equipment trace
TraceVie wer
4.1.6 PMO administration Table 8: PMO administration shows procedures relevant for PMO administration.
Issue: 04
DN0958759
29
Operating tasks related to monitoring and measuring system in LTE RAN
Table 8
Procedure title
Monitoring and Measuring System in LTE RAN
PMO administration
Procedure description
Trace Configuration of administration subscriber/UE trace parameters (IMSI/IMEI, trace depth, trace schedule)
PM data category
Procedure trigger
Evaluation interval
Target group
PM function
PM tool
administratio n
on demand
online
Network operation
Subscriber and equipment trace
TraceV iewer
Cell trace
Subscriber trace activation: SBA, MBA Configuration of cell traffic trace parameters (list of traced cells, trace depth, trace schedule, maximum number of traced connections) Cell traffic trace activation: MBA
4.2 PMO measurement procedures The PMO measurement use cases describe the measurement targets of certain PM KPIs and PM counters to understand the added value for certain KPIs and counters, for example why, how, and when to use certain KPIs and counters. The PMO measurement procedures can be either subdivided into categories, procedure areas, or into certain technology specific performance indicator groups (PI groups).
4.2.1 Categories • • • • • •
accessibility retainability mobility integrity network usage availability
4.2.2 Procedure areas • • • • •
30
troubleshooting traffic load resource availability quality of service, grade of service performance
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Operating tasks related to monitoring and measuring system in LTE RAN
4.2.3 Technology Specific Performance Indicator Groups (PI Groups) • • • • • • • •
connection setup procedures release procedures handover procedures HW and Platform indicators interface utilization quality of service transport availability
For the design of a performance monitoring system, these PMO measurement procedures are of major importance to understand the related KPI and PM counters.
4.3 eNB monitoring procedures This section gives an overview about procedures to monitor and optimize an LTE network by using performance measurements collected inside the eNB. For permanent supervision of the LTE network, performance measurements at the eNB are taken into account. Additionally, those eNB performance measurements are used for troubleshooting and network optimization. The most important procedures are as follows:
• • •
Performance supervision of the LTE Radio Network Layer (RNL) and Transport Network Layer (TNL) Localization of sources of insufficient performance, capacity, or quality Troubleshooting and network optimization at the eNB with performance data
4.3.1 Performance supervision of the LTE RNL and TNL Table 9: Performance supervision of the LTE RNL and TNL gives an overview of the relevant procedure. Table 9
Performance supervision of the LTE RNL and TNL
Procedure #1
Performance supervision of the LTE RNL and TNL
Objective
To supervise the performance, capacity, and quality of the network by permanent supervision of PM KPIs.
Description
The operator must be able to monitor the LTE network for all cells permanently with the PM based KPIs of the following PM categories:
• • •
Issue: 04
accessibility retainability mobility
DN0958759
31
Operating tasks related to monitoring and measuring system in LTE RAN
Table 9
Procedure #1
Monitoring and Measuring System in LTE RAN
Performance supervision of the LTE RNL and TNL (Cont.)
Performance supervision of the LTE RNL and TNL
• • •
integrity network usage quality
The operator must be able to:
• • • • • • •
4.3.1.1
see the overall performance for a certain cell compare the performance and quality of the LTE network with other technologies compare the performance and quality of an eNB with another eNB supervise the performance, capacity, or quality of the transmission lines between eNBs and the core network see performance degradations over time see on a high level whether the offered quality is sufficient for the end customers monitor the network usage to enhance the network resources in time
Frequency
Every 60 minutes
Observed object
per eNB
Monitoring capacity license/number of active users per BTS Because of licensing, it is required to monitor the maximum number of active UEs. In case a licensing mechanism is available in the eNB, the maximum number of active users per Flexi Multiradio BTS is controlled by a capacity license. The measurements allow the operator to supervise the eNB load in case of active users. The following measurements are required:
• • •
number of UEs with buffered data number of active UEs per cell number of active UEs per eNB
4.3.2 Localization of sources of insufficient performance, capacity, or quality Table 10: Localization of sources of insufficient performance, capacity, or quality gives an overview of the relevant details of the procedure:
32
DN0958759
Issue: 04
Monitoring and Measuring System in LTE RAN
Table 10
Operating tasks related to monitoring and measuring system in LTE RAN
Localization of sources of insufficient performance, capacity, or quality
Procedure #2
Localization of sources of insufficient performance, capacity or quality
Objective
In case of insufficient performance, capacity or quality of procedure #1, the operator must be able to find out the location of the problem, such as cell or interfaces, capacity, or quality based on Performance supervision of the LTE RNL and TNL.
Description
In case of procedure #1, if it turns out that a certain eNB has insufficient performance, capacity or quality, then the operator must be able to find out the location of problem (for example cell, interface, and so on). Therefore, the operator must be able to evaluate performance measurements per cell and/or per interfaces to find the source of the problem with PM-based KPIs of the following PM categories:
• • • • • •
accessibility retainability mobility integrity network usage quality
Frequency
Every 15 minutes
Observed object
per eNB / cell / interface
4.3.3 Troubleshooting and network optimization at the eNB with the performance data Table 11: Troubleshooting and network optimization at the eNB with performance data gives an overview of the relevant details of the procedure: Table 11
Issue: 04
Troubleshooting and network optimization at the eNB with performance data
Procedure #3
Troubleshooting and network optimization at the eNB with performance data
Objective
To evaluate the eNB performance measurements for troubleshooting purposes to detect and locate the problems, and to optimize eNB configurations.
Description
The operator must be able to evaluate eNB performance measurements or diagnostic data in case a customer complains (subscriber), for example, if it is not possible to setup a connection. The operator must be able to find out the location and reason of the problem, for example, determine whether the problem is located at
DN0958759
33
Operating tasks related to monitoring and measuring system in LTE RAN
Table 11
Monitoring and Measuring System in LTE RAN
Troubleshooting and network optimization at the eNB with performance data (Cont.)
Procedure #3
Troubleshooting and network optimization at the eNB with performance data the air interface, eNB, S1 interface, transmission line, or MME / SGW. The operator must be able to retrieve historical performance data or diagnostic data regarding:
• • •
accessibility (for example: connection setup) retainability (for example: connection drop rate) quality of the air interface
The upload and evaluation are performed for troubleshooting of a certain eNB.
34
Frequency
Every 15 minutes
Observed object
per eNB / cell / interface
DN0958759
Issue: 04
View more...
Comments
