BSS Performance Management Guidelines(V900R008C01_01).pdf

HUAWEI BSC6000 Base Station Subsystem

V900R008

BSS Performance Management Guidelines

Issue 01

Date 2008-06-10

INTERNAL

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Contents

About This Document.....................................................................................................................1

1 Introduction to Performance Management...........................................................................1-11.1 Definition of Performance Management.........................................................................................................1-21.2 Functions of Performance Management.........................................................................................................1-21.3 Performance Management Tools....................................................................................................................1-2

1.3.1 Nastar.....................................................................................................................................................1-31.3.2 OMStar...................................................................................................................................................1-51.3.3 Probe.......................................................................................................................................................1-51.3.4 Assistant.................................................................................................................................................1-61.3.5 U-Net......................................................................................................................................................1-91.3.6 Air Trace................................................................................................................................................1-9

2 Principles of Performance Management...............................................................................2-12.1 Structure of the Performance Management System........................................................................................2-22.2 Structure and Classification of Performance Data..........................................................................................2-3

2.2.1 Structure of the BSS Performance Data.................................................................................................2-32.2.2 Classification of the BSS Performance Data..........................................................................................2-5

2.3 Collection and Storage of Performance Data..................................................................................................2-72.3.1 Principles of Collection and Storage of Performance Data....................................................................2-82.3.2 Collection of Performance Data.............................................................................................................2-92.3.3 Storage of Performance Data.................................................................................................................2-92.3.4 Provision of Performance Data............................................................................................................2-11

3 Evaluation of Routine Network Performance......................................................................3-13.1 Introduction to Evaluation of Routine Network Performance Evaluation......................................................3-23.2 Items and Evaluation of Routine Network Performance Monitoring.............................................................3-2

3.2.1 Daily Report of Routine Network Performance Monitoring..................................................................3-23.2.2 Weekly Report of Routine Network Performance Monitoring............................................................3-113.2.3 Monthly Report of Routine Network Performance Monitoring...........................................................3-143.2.4 RNP Parameter Verification.................................................................................................................3-14

3.3 Routine Network Performance Monitoring Report Reference......................................................................3-163.3.1 Routine Network Performance Monitoring Report (for Engineers)....................................................3-173.3.2 Routine Network Performance Monitoring Report (for Project Managers)........................................3-193.3.3 Routine Network Performance Monitoring Report (for Comparison).................................................3-21

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4 Analysis and Optimization of Network Performance........................................................4-14.1 Introduction to Analysis and Optimization of Network Performance............................................................4-34.2 Performance Analysis Process........................................................................................................................4-3

4.2.1 Performance Statistics Analysis Process................................................................................................4-34.2.2 Performance History Records Analysis Process....................................................................................4-54.2.3 Tracing and Monitoring Data Analysis Process.....................................................................................4-7

4.3 Performance Statistics Analysis......................................................................................................................4-74.3.1 Performance Statistics Analysis Process................................................................................................4-84.3.2 Collecting the Performance Data of the Current Network.....................................................................4-94.3.3 Generating Reports by the Nastar..........................................................................................................4-94.3.4 Analysis of Network KPIs....................................................................................................................4-104.3.5 Analysis of Top N Cells.......................................................................................................................4-114.3.6 Outputting Solutions or Suggestions....................................................................................................4-11

4.4 Optimization Against Missing Neighboring Cell Configuration..................................................................4-114.4.1 Introduction to Missing Neighboring Cell Configuration....................................................................4-124.4.2 Analysis of Missing Neighboring Cell Configuration.........................................................................4-124.4.3 Implementation of Optimization Against Missing Neighboring Cell Configuration..........................4-12

4.5 Optimization Against Call Drop Rate...........................................................................................................4-134.5.1 Introduction to Call Drop Rate.............................................................................................................4-144.5.2 Analysis of Call Drop Rate..................................................................................................................4-154.5.3 Implementation of Optimization Against Call Drop Rate...................................................................4-16

4.6 Optimization Against Interference................................................................................................................4-174.6.1 Introduction to Interference..................................................................................................................4-184.6.2 Analysis of Interference.......................................................................................................................4-184.6.3 Implementation of the Optimization Against Interference...................................................................4-20

4.7 Optimization Against Low Paging Rate........................................................................................................4-214.7.1 Introduction to Low Paging Success Rate............................................................................................4-214.7.2 Analysis of Low Paging Success Rate.................................................................................................4-214.7.3 Implementation of the Optimization Against Low Paging Success Rate............................................4-23

4.8 Optimization Against Low MOS..................................................................................................................4-234.8.1 Introduction to Low MOS....................................................................................................................4-244.8.2 Analysis of Low MOS..........................................................................................................................4-244.8.3 Implementation of the Optimization Against Low MOS.....................................................................4-27

4.9 Optimization Against Low Handover Rate...................................................................................................4-294.9.1 Introduction to Low Handover Success Rate.......................................................................................4-294.9.2 Analysis of Low Handover Success Rate............................................................................................4-294.9.3 Implementation of the Optimization Against Low Handover Success Rate........................................4-31

4.10 Optimization Against Poor Network Coverage..........................................................................................4-334.10.1 Introduction to Poor Network Coverage............................................................................................4-344.10.2 Analysis of Poor Network Coverage..................................................................................................4-344.10.3 Optimization Implementation Against Poor Network Coverage.......................................................4-35

5 Real-Time Monitoring...............................................................................................................5-1

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5.1 Functions of Real-Time Monitoring...............................................................................................................5-25.2 KPIs Involved in Real-Time Monitoring........................................................................................................5-2

6 Call History Records Reference...............................................................................................6-16.1 Introduction to Call History Records..............................................................................................................6-26.2 Call History Records Data Area Reference.....................................................................................................6-3

6.2.1 Common Information Area of CHRs.....................................................................................................6-36.2.2 Trace Area of CHRs...............................................................................................................................6-96.2.3 Measurement Report Area of CHRs....................................................................................................6-106.2.4 Field Information Area of CHRs..........................................................................................................6-11

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Figures

Figure 2-1 Network Architecture of GBSS Performance Management...............................................................2-2Figure 2-2 Hierarchical structure of the BSS performance data..........................................................................2-4Figure 2-3 Performance data levels......................................................................................................................2-6Figure 2-4 Hierarchical structure of performance management...........................................................................2-8Figure 3-1 KPI sheets in a daily report................................................................................................................3-3Figure 3-2 KPI sheet in a weekly report............................................................................................................3-12Figure 3-3 A sheet of RNP parameter verification.............................................................................................3-15Figure 3-4 A sheet of the monitoring report for engineers.................................................................................3-17Figure 3-5 A sheet of the monitoring report for project managers.....................................................................3-20Figure 3-6 KPI sheet in a weekly report............................................................................................................3-22Figure 4-1 Performance statistics analysis process..............................................................................................4-4Figure 4-2 Performance history records analysis process....................................................................................4-6Figure 4-3 Tracing and monitoring data analysis process....................................................................................4-7Figure 4-4 Performance statistics analysis process..............................................................................................4-8Figure 4-5 Process of optimization against missing neighboring cell configuration.........................................4-13Figure 4-6 Distribution of test quality codes......................................................................................................4-26Figure 4-7 Process of the optimization against low MOS..................................................................................4-28Figure 4-8 Process of the optimization against low handover success rate.......................................................4-32Figure 4-9 Signaling of a failed cell incoming handover...................................................................................4-33Figure 6-1 CHR interface.....................................................................................................................................6-2Figure 6-2 General information interface of common information area..............................................................6-3Figure 6-3 Identifier information interface of the common information area......................................................6-7Figure 6-4 Basic resource information interface of the common information area.............................................6-8Figure 6-5 Interface of the track information area...............................................................................................6-9Figure 6-6 Interface of the measurement report area.........................................................................................6-11Figure 6-7 Interface of the field information area..............................................................................................6-12

HUAWEI BSC6000 Base Station SubsystemBSS Performance Management Guidelines Figures


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Tables

Table 1-1 Main functions of the Nastar................................................................................................................1-4Table 1-2 Main functions of the Assistant............................................................................................................1-7Table 2-1 Classification of BSS performance data..............................................................................................2-4Table 3-1 Sheets in a daily report.........................................................................................................................3-4Table 3-2 Evaluation and analysis of the accessibility KPIs................................................................................3-6Table 3-3 Evaluation and analysis of the CDR KPIs...........................................................................................3-7Table 3-4 Evaluation and analysis of the mobility KPIs....................................................................................3-10Table 3-5 Sheets in a weekly report...................................................................................................................3-12Table 3-6 Items and functions of the RNP parameter verification.....................................................................3-15Table 3-7 Items of the monitoring report for engineers.....................................................................................3-18Table 3-8 Items of the monitoring report for project managers.........................................................................3-21Table 3-9 Items of the monitoring report for comparison..................................................................................3-23Table 4-1 Network KPIs.....................................................................................................................................4-10Table 4-2 Five levels of MOS............................................................................................................................4-24Table 4-3 Different codes and corresponding MOS...........................................................................................4-27Table 6-1 Description of general information......................................................................................................6-4Table 6-2 Description of basic resource information...........................................................................................6-8Table 6-3 Description of track information........................................................................................................6-10

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About This Document

Overview

This describes the performance management principle, performance data, performance analysismethods, and performance problem solutions.

Product Versions

The following table lists the product versions related to this document.

Product Name Model Product Version

BSC BSC6000 V900R008C01

BTS BTS3012 V300R004&V300R005&V300R006

BTS3012AE V300R005&V300R006

BTS3006C V300R005&V300R006

BTS3002E V300R005

BTS3036/BTS3900GSM

V300R008

BTS3036A/BTS3900AGSM

V300R008

DBS3036/DBS3900GSM

V300R008

M2000 M2000 V200R006

Intended Audience

This document is intended for:

l Network planners

l Network administrators

l Network operators

HUAWEI BSC6000 Base Station SubsystemBSS Performance Management Guidelines About This Document


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Change History

Refer to Changes in BSS Performance Management Guidelines.

Organization

1 Introduction to Performance Management

This describes the definition of performance management and the structure of the performancemanagement system.

2 Principles of Performance Management

This describes the structure, classification, collection, and storage of the performance data inperformance management.

3 Evaluation of Routine Network Performance

This describes routine network performance evaluation that is implemented through the analysisof routine reports.

4 Analysis and Optimization of Network Performance

This describes network performance analysis and optimization that involve the general policyof performance problem analysis, traffic statistics analysis, optimization against missing co-channel neighboring cell configuration, optimization against call drops, optimization againstinterference, optimization of paging success rate, optimization against low mean opinion score(MOS), optimization of handover success rate, and optimization of network coverage.

5 Real-Time Monitoring

You can monitor the system on the M2000 Client and thus monitor the quality of the wirelessnetwork.

6 Call History Records Reference

This describes call history records (CHRs). The CHRs include four areas: common informationarea, track information area, measurement report area, and field information area.

Conventions

1. Symbol Conventions

The following symbols may be found in this document. They are defined as follows

Symbol Description

DANGERIndicates a hazard with a high level of risk that, if not avoided,will result in death or serious injury.

WARNINGIndicates a hazard with a medium or low level of risk which, ifnot avoided, could result in minor or moderate injury.

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Symbol Description

CAUTIONIndicates a potentially hazardous situation that, if not avoided,could cause equipment damage, data loss, and performancedegradation, or unexpected results.

TIP Indicates a tip that may help you solve a problem or save yourtime.

NOTE Provides additional information to emphasize or supplementimportant points of the main text.

2. General Conventions

Convention Description

Times New Roman Normal paragraphs are in Times New Roman.

Boldface Names of files,directories,folders,and users are in boldface. Forexample,log in as user root .

Italic Book titles are in italics.

Courier New Terminal display is in Courier New.

3. Command Conventions


Boldface The keywords of a command line are in boldface.

Italic Command arguments are in italic.

[ ] Items (keywords or arguments) in square brackets [ ] are optional.

{x | y | ...} Alternative items are grouped in braces and separated by verticalbars.One is selected.

[ x | y | ... ] Optional alternative items are grouped in square brackets andseparated by vertical bars.One or none is selected.

{ x | y | ... } * Alternative items are grouped in braces and separated by verticalbars.A minimum of one or a maximum of all can be selected.

[ x | y | ... ] * Alternative items are grouped in braces and separated by verticalbars.A minimum of zero or a maximum of all can be selected.

4. GUI Conventions

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Boldface Buttons,menus,parameters,tabs,window,and dialog titles are inboldface. For example,click OK.

> Multi-level menus are in boldface and separated by the ">" signs.For example,choose File > Create > Folder .

5. Keyboard Operation


Key Press the key.For example,press Enter and press Tab.

Key1+Key2 Press the keys concurrently.For example,pressing Ctrl+Alt+Ameans the three keys should be pressed concurrently.

Key1,Key2 Press the keys in turn.For example,pressing Alt,A means the twokeys should be pressed in turn.

6. Mouse Operation

Action Description

Click Select and release the primary mouse button without moving thepointer.

Double-click Press the primary mouse button twice continuously and quicklywithout moving the pointer.

Drag Press and hold the primary mouse button and move the pointerto a certain position.

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1 Introduction to Performance Management

About This Chapter

This describes the definition of performance management and the structure of the performancemanagement system.

1.1 Definition of Performance ManagementThis describes the definition of performance management. Serving as one of the functionaldomains of Telecommunication Management Network (TMN), performance management isused to monitor, analyze, and control the network performance.

1.2 Functions of Performance ManagementThis describes the basic functions of performance management. The basic function ofperformance management is the measurement of the performance data. Evaluation, diagnosis,and optimization are performed based on the measurement result.

1.3 Performance Management ToolsThis describes the performance management tools, including Nastar, OMStar, Probe, Assistant,U-Net, and Air Trace.

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1.1 Definition of Performance ManagementThis describes the definition of performance management. Serving as one of the functionaldomains of Telecommunication Management Network (TMN), performance management isused to monitor, analyze, and control the network performance.

BSC performance management includes performance measurement, flow control, and resourcecheck. Performance measurement, flow control, and resource check are triggered by events.

l Flow control is performed in the BSC system and on the Abis interface.

l Resource check can be initiated by the BSC and the LMT.

Performance management is used to collect performance data of the network, equipment,functions, services, or other objects periodically or in event-triggering mode, or to collectperformance-related flow data. Then, performance management analyzes and processes thecollected data, and then saves and manages the collected data.

By monitoring and analyzing the collected data, performance management reports the operatingstatus of the equipment and the network and evaluates the validity of the network, networkelements (NEs), and other objects. In addition, performance management supports networkplanning and optimization; thus improving the network performance and ensuring high servicequality of the radio network.

During network operation, network maintenance, or network optimization, GBSS performancemanagement collects the data that is used to check the physical or logical configuration of thenetwork for correctness, and monitors the traffic counters. Thus, the potential problems can belocated and rectified.

1.2 Functions of Performance ManagementThis describes the basic functions of performance management. The basic function ofperformance management is the measurement of the performance data. Evaluation, diagnosis,and optimization are performed based on the measurement result.

Performance management has the following functions:

l Performance data analysis

l Performance data management, including collection, recording, and storage.

The GBSS performance management provides the following functions:

l Isolating, locating, and rectifying problems

l Providing important reference data for network optimization and routine data for networkmanagement

l Helping to analyze and forecast network trends

l Providing routine reports and health checks

1.3 Performance Management ToolsThis describes the performance management tools, including Nastar, OMStar, Probe, Assistant,U-Net, and Air Trace.

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1.3.1 NastarNastar performs comprehensive analysis on the performance data, configuration parameters,and engineering parameters of the GSM BSS network. It provides multiple display modes usedfor network planning, performance analysis, and geographical display.

1.3.2 OMStarThis describes OMStar, which is a BSS maintenance and test tool. OMStar is used to performalarm management and routine maintenance. This tool is designed for system engineers, shiftoperators, and network operators. Together with Nastar, OMStar can help to rapidly isolateequipment problems from other the network problems.

1.3.3 ProbeProbe is a high-performance test tool used on the air interface in WCDMA, HSDPA, GSM, andGPRS. It is used for data collection and verification of radio network planning and optimization.

1.3.4 AssistantAssistant is a professional background analysis tool. It supports the WCDMA, HSDPA, GSM,and GPRS modes and is compatible with multiple formats of drive test data provided by theleading manufacturers. The Assistant performs the functions such as uplink and downlink datacombination analysis, intelligent expert system, event simulation, displaying, statistics, filtering,and reporting.

1.3.5 U-NetThis describes U-Net, which is a network planning tool and one of the Genex series wirelesstools developed by Huawei. It provides global support for initial network design, dense networkplanning construction, and network optimization. This tool is designed for network planners.

1.3.6 Air TraceThis describes Air Trace, which is a tool for analyzing the messages of general MSs and signalingmessages. This tool is designed for network planners and performance analysis engineers toretrieve and analyze signaling messages.

1.3.1 NastarNastar performs comprehensive analysis on the performance data, configuration parameters,and engineering parameters of the GSM BSS network. It provides multiple display modes usedfor network planning, performance analysis, and geographical display.

Through network monitoring report, RNP configuration check, weekly and monthly report,swapping report, and theme query, the Nastar for GSM helps the users in terms of dailymonitoring and maintenance, problem location and troubleshooting. Thus, the work efficiencyis greatly enhanced.

The applications of the Nastar are as follows:

l Analyze frequencies and neighbor cells

l Monitor the performance of the entire network

l Analyze the network problems and locate the faults

Table 1-1 lists the main functions of the Nastar.



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Table 1-1 Main functions of the Nastar

Function Description

Data import By processing a single data or multiple data, the Nastar helps theengineers to know comprehensively the network performance and tolocate problems quickly. The Nastar supports the following datasources:l Engineering parameters

l Configuration data

l Traffic measurement data (including BSC traffic data and the PCUtraffic data)

Geographical display Geographical display of the Nastar consists of the following:l Site navigation

l BSC coverage display

l Location area display

l Configuration parameter display

l GSM900/DCS1800 layer switch

l Engineering parameter rendering

l Cell ID

l Special topic diagram display

Frequency analysisand optimization

Frequency analysis and optimization of the Nastar involves thefollowing checks:l Check of co-channels and adjacent channels

l Check of co-channel and co-BSIC

l Check of idle frequencies

l Check of frequency hopping

l Check of frequency optimization

Analysis andoptimization forneighbor cells

The Nastar checks the redundant and miss-configured cells andprovides suggestions of the optimization for neighbor cells.l Maintenance of neighbor cells

l Automatic planning of neighbor cells

l Check of unidirectional neighbor cells

l Check of less neighbor cells (the number of neighbor cells is lowerthan the preset minimum value)

l Solution to neighbor cell optimization problems




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Performance dataanalysis andextensive reports

The Nastar comprehensively analyzes the performance data andoutputs various reports.l The daily network reports are as follows:

– Network monitor report

– PCU monitor report

– Daily, weekly, and monthly reports

– Swapping comparison report

– Radio quality report

– Health check report

– Comprehensive network expansion report

l The following are comprehensively analyzed:– KPI performance

– Access performance

– Retainability performance

– Mobility performance

– TRX performance

– Resource usage

– PS-domain KPI performance

Configuration check The Nastar performs the configuration check based on the analysis ofthe performance data, configuration data, and engineeringparameters. It compares and checks the correctness and reasonabilityof the following data:l RNP check report of the BSC

l RNP check report of the PCU

1.3.2 OMStarThis describes OMStar, which is a BSS maintenance and test tool. OMStar is used to performalarm management and routine maintenance. This tool is designed for system engineers, shiftoperators, and network operators. Together with Nastar, OMStar can help to rapidly isolateequipment problems from other the network problems.

OMStar provides the BSC and BTS with a platform for maintenance and test. The platform helpsto reduce routine maintenance workload, prevent, detect, locate, and solve equipment problems.

The data sources of OMStar are alarm data and running logs.

1.3.3 ProbeProbe is a high-performance test tool used on the air interface in WCDMA, HSDPA, GSM, andGPRS. It is used for data collection and verification of radio network planning and optimization.

The applications of the Probe are as follows:



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l Test the network quality and radio parameters.

l Decode the messages on the air interface and display in real time the data, cells, andgeographical locations.

l Monitor, trace, and test the system status in real time

The Probe provides the following functions:

l Supports multi-mode tests in WCDMA, HSDPA, GSM, and GPRS

l Supports multiple CS and PS service tests

l Supports multi-MS tests

l Supports Scanner tests

l Supports indoor tests

l Supports the presetting of test plans

l Supports the judgment of predefined events

l Supports hardware alarms

l Supports filtering of the received data

l Supports automatic saving, exporting, and retrieving of the log

l Displays co-activated information

l Displays radio measurement parameters geographically in real time

l Adjusts the GPS location information dynamically and statically

l Displays and interprets the air interface messages

l Displays the RLC and APP throughput

l Displays customized parameters

l Supports GPS timing synchronization

1.3.4 AssistantAssistant is a professional background analysis tool. It supports the WCDMA, HSDPA, GSM,and GPRS modes and is compatible with multiple formats of drive test data provided by theleading manufacturers. The Assistant performs the functions such as uplink and downlink datacombination analysis, intelligent expert system, event simulation, displaying, statistics, filtering,and reporting.

The applications of the Assistant are as follows:

l Help to get familiar with the network performance, locate the network problems, andimprove the network quality.

l Verify the radio network planning and optimization results

Table 1-2 lists the main functions of the Assistant.




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Table 1-2 Main functions of the Assistant


Analyzing the testdata in WCDMA-GSM dual mode

The Assistant analyzes the test data in the WCDMA and GSMnetworks. It supports independent display of engineering parametersand independent display of data in real time.

Supporting data fromdifferent test devices

The Assistant can import the test data from the Probe, Huawei RNC,DTI Scanner, Anritsu Scanner, Agilent E6474A, and AgilentE7476A. It offers excellent display and analysis of the test counters.

Flexibly adding thetype of the drive testdata

For the new equipment, you need only to update the correspondingfile.

Supporting fourgeographic binningmodes and three datasampling methods

The four geographic binning modes are distance binning, gridbinning, time binning, and no binning. The three data samplingmethods are average value sampling, maximum value sampling, andminimum value sampling.

Independentlyanalyzing the drivetest devices

The Assistant supports independent display and analysis of thedevices and the frequencies.

Supportingenvironment ofscrambling codemultiplexing

The Assistant analyzes the environments for scrambling codesmultiplexing on a large-scale network.

Automaticallycombining the drivetest files

The Assistant automatically combines the drive test files.

Comprehensivelyanalyzing the uplinkand downlink data

By synchronizing the system time with the GPS time, the Assistantdisplays the drive test data and comprehensively analyzes the uplinkand downlink data.

Analyzing bygeographic area ortime segment

The Assistant supports data analysis by geographical area or timesegment. After a geographical area or a time segment is locked, allanalysis is performed based on the specified data.

Displaying the drivetest track

In geographical display mode, the Assistant automatically displaysthe drive test track and adjusts the display parameters.

Supporting test dataplayback

The system supports automatic and manual playback of the test data,display of the problematic parameters in detail, and quick problemlocation.



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Supporting multipledata display modes

The data display modes that integrate the common operations consistof the map, curve chart, customized XY chart, PDF chart, and Excel.In map mode, the Assistant provides fast pilot line, layer offset,overlapped path filtering, area memory, and engineering parametercontrol and display.In curve chart mode, the Assistant supports dynamic modification anddragging of data curves, graph zooming and rotating, and chartcustomization.In Excel mode, the Assistant supports searching, copying, andcommon calculations.

Supportingbidirectional multi-window co-activation

The Assistant supports bidirectional multi-window co-activationamong maps, charts, Excels, and signaling events.

Displaying the real-time data

The Assistant provides the real-time display of the Scanner coverageand the UE pilot information.

Parsing Layer 3signaling

The Assistant supports parsing the RRC, NAS, and RR signaling onlayer 3. It also supports searching a text by message name and messagebody.

Supporting variousapplication analysisitems

For the Scanner data, the Assistant supports handover eventsimulation, pilot pollution analysis, soft handover statistics, adjacentcell relation analysis, and detailed analysis report.The Assistant also provides analysis reports on UE network eventpredefinition, PS service statistics, and CS service statistics.

Exporting data indifferent formats

The Assistant supports data export in different formats, suchas .bmp, .txt, and .xls.

Filtering data bycounter

The Assistant filters the imported data by counter.

Word collector The Assistant exports the browsed pictures and Excels to a Word file.

Simulating theclosure of a singleScanner site

The Assistant supports simulating the closure of a single Scanner siteor cell. By closing a site, the Assistant simulates the changes of thepilot signals at a test point to evaluate the impact of the site on the testpoint. The focus should be on the recalculation of the RSSI on thedrive test point covered by the site.

Automaticallymatching RNCmessages

The Assistant supports automatic matching between the RNC dataand UE data during RNC data import.

Analyzing theHSDPA statistics

HSDPA statistics indicates the current network performance andservice performance, rate statistics and channel decoding statistics,and parameter configuration.

Measuring thecounters by site

The Assistant measures by site the key counters such as the SHO, callsetup, call drop, and call setup failure.




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Intelligent reportsystem

The Assistant automatically generates a drive test report.

1.3.5 U-NetThis describes U-Net, which is a network planning tool and one of the Genex series wirelesstools developed by Huawei. It provides global support for initial network design, dense networkplanning construction, and network optimization. This tool is designed for network planners.

The functions of U-Net are as follows:

l Support of multiple network technologies and 2G/3G interoperability

l Support of link budget and network estimating

l Support of forecasting simulation for coverage and capacity

l Support of verification for drive test data

l Support of planning for antenna angles

l Support of automatic planning for sites

l Support of automatic calibration and preplanning for propagation model

1.3.6 Air TraceThis describes Air Trace, which is a tool for analyzing the messages of general MSs and signalingmessages. This tool is designed for network planners and performance analysis engineers toretrieve and analyze signaling messages.

The functions of Air Trace are as follows:

l The object-oriented design applies to multiple protocols and hardware. It can be used formultiple test MSs, such as SAGEM OT35/55/75/76/96, and serial ports. The OTX5 andOTX6 are configured with different software versions.

l The optimized file storage technology helps to record data for a long time and to show datapromptly.

l The optimized data buffer technology helps to display multiple windows without messageloss.

l The message automatic storage function ensures that messages are not lost in the case ofpower failure and breakdown.



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2 Principles of Performance Management

About This Chapter

This describes the structure, classification, collection, and storage of the performance data inperformance management.

2.1 Structure of the Performance Management SystemThis describes the structure of the performance management system. The performancemanagement system has four layers: Network Management Layer (NML), Sub-NetworkManagement Layer (SNML), Local Element Management Layer (LEML), and NetworkElement Layer (NEL).

2.2 Structure and Classification of Performance DataThis describes various performance data that supports performance management. Differentapplications of performance management have different requirements, such as collectiongranularity and integrity, for performance data. Therefore, performance data can be classifiedinto different levels and categories.

2.3 Collection and Storage of Performance DataThis describes the principles of performance data collection and storage. In addition, thisdescribes how to collect, store, and provide Level 1 data, Level 2 data, and Level 3 data.

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2.1 Structure of the Performance Management SystemThis describes the structure of the performance management system. The performancemanagement system has four layers: Network Management Layer (NML), Sub-NetworkManagement Layer (SNML), Local Element Management Layer (LEML), and NetworkElement Layer (NEL).

Figure 2-1 shows the network architecture of GBSS performance management.

Figure 2-1 Network Architecture of GBSS Performance Management

NML

SNML

S-IRP

FM CM PM SM SWM

FM CM PM SM SWM

FM CM PM SM SWM

LEML

NEL

FM P-IRP CM P-IRP PM P-IRP FTP/FTAM

l NML

The network management equipment that is at the upper layer of the M2000 is located atthe NML. The equipment helps to browse and analyze performance analysis results.

l SNML

The performance management console provided by the M2000 is located at the SNML.The console facilitates comprehensive analysis of the data in the subnet.

l LEML

The performance management console provided by the LMT is located at the LEML andfacilitates comprehensive analysis of the data in the local network.

l NEL

2 Principles of Performance ManagementHUAWEI BSC6000 Base Station Subsystem



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In the BSC6000 system, the performance management modules deployed in the OMU andthe service board are located at the NEL. The performance management modules are usedfor data collections and preprocessing.

NOTE

l The functions of NM, SNM, and LEM are implemented by independent devices. For example, independentM2000 devices and LMT devices implement the SNM functions and the LEM functions respectively in theBSS management system.

l The equipment that implements the functions of NEs is a component of the managed object. For example,the functions of BSC6000 NEs are implemented through the OMU and other service boards.

l The network management (NM) equipment facilitates the communication between the management systemand managed system. The NM is embedded in the hardware and software. The NM is responsible formonitoring alarms and the operating status of equipment, collecting the operation and maintenance (OM)data, such as alarm data, performance data, and status-related data, and sending the data to the local NMequipment through management interfaces. The NM equipment is only an auxiliary to the networkmanagement system and does not perform management functions.

2.2 Structure and Classification of Performance DataThis describes various performance data that supports performance management. Differentapplications of performance management have different requirements, such as collectiongranularity and integrity, for performance data. Therefore, performance data can be classifiedinto different levels and categories.

2.2.1 Structure of the BSS Performance DataThis describes the structure of the BSS performance data. Performance data can be categorizedinto three levels: performance statistics, performance history records, and tracing and monitoringdata. Each level is classified into several types.

2.2.2 Classification of the BSS Performance DataThis describes the levels of the BSS performance data. According to the width and depth shownthrough the Level axis, the BSS performance data can be classified into three levels: Level 1,Level 2, and Level 3.

2.2.1 Structure of the BSS Performance DataThis describes the structure of the BSS performance data. Performance data can be categorizedinto three levels: performance statistics, performance history records, and tracing and monitoringdata. Each level is classified into several types.

Hierarchical StructureFigure 2-2 shows the hierarchical structure of performance data.



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Figure 2-2 Hierarchical structure of the BSS performance data

Health checkand generalevaluation

Location of commonperformance

problems

Location of deep-seatedperformance problems

PSPerformance

KPIs

CHR

Signaling message tracingSystem monitoring

In the hierarchical structure model of the BSS performance data, the lower the level is, the moreabstract and more general the data is. The data of different levels should be unique as far aspossible.

Three Levels of Performance Datal Level 1: Performance Statistics

The level 1 data is used for checking performance health and evaluating generalperformance. It is oriented to network operators.

l Level 2: Performance History Records

The level 2 data is used for analyzing and locating common performance problems. It isoriented to senior network operators or the Network Information Center (NIC) of carriers.

l Level 3: Tracing and Monitoring Data

The level 3 data is used for locating deep-seated performance problems. It is oriented toexperienced and senior specialists.

Sublevels of Performance Data

Table 2-1 shows the sublevels of BSS performance data.

Table 2-1 Classification of BSS performance data

Item Sub-Item Functions Collection Mode

Performancestatistics

KPI KPI monitoring, KPIreports, and northboundinterface

Data is collectedperiodically with smallgranularity.




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Item Sub-Item Functions Collection Mode

Commonperformancecounter

Performance data reports,northbound interface,general networkperformance, trafficvolume, and equipmentusage evaluation

Data is collectedperiodically. TheBSC32 supports datacollection at intervalsof 5, 15, 30, 60, and1440 minutes and theBSC6000 supports datacollection at intervalsof 15 and 60 minutes.

PerformanceHistory Records

Call historyrecord (CHR)

CDR analysis, QoSevaluation, commonproblem location, anduser complaint handling

Data collection istriggered by events orall data is collected.Abnormal calls arecollected automaticallyand normal calls arecollected undercontrol.

Tracing andMonitoring Data

Trace usermessages

Further analysis of theproblems, which cannotbe located according toCHRs, by analyzingspecified IMSIs orrandom IMSIs that areadmitted on the TRXswith high call drop rates

Data collection istriggered by events.Users need to start orstop collection of data.

Systemmonitoring

Real-time recording ofsystem status, such as loadinformation andinterference information,to help locate deep-seatedproblems

2.2.2 Classification of the BSS Performance DataThis describes the levels of the BSS performance data. According to the width and depth shownthrough the Level axis, the BSS performance data can be classified into three levels: Level 1,Level 2, and Level 3.

Performance data width that is shown through the Broad axis indicates the status of systemperformance and the scope of the problems involved. Performance data depth that is shownthrough the Level axis indicates the capability for handling performance problems. In addition,the width and depth show the requirements of different performance management applications,such as the requirements for data, analysis tools, and network topologies.

Figure 2-3 shows the performance data levels.



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Figure 2-3 Performance data levels

Level 3 Level 2 Level 1

Level 3

Level 2

Level 1

Broad

ToolsProbe/Assistant/

Signal Analyze ToolOMStar Nastar/OMStar

Drive Test

Single UserTrace

CallHistroy Register

Statistics

Alarm Log

2.2.2.1 Performance StatisticsThis describes the Level 1 data. Level 1 data is mainly the performance statistics and alarm data.Performance statistics are analyzed through Nastar and alarm data is analyzed through OMStar.

2.2.2.2 Performance History RecordsThis describes the Level 2 data. The Level 2 data is mainly the Call History Records (CHRs)and is analyzed by OMStar.

2.2.2.3 Tracing and Monitoring DataThis describes the Level 3 data. The Level 3 data is mainly single MS tracing data and drive testdata. The Signal Analyze Tool can be used to analyze single MS data and Probe can be used tocollect the drive test data.

Performance Statistics

This describes the Level 1 data. Level 1 data is mainly the performance statistics and alarm data.Performance statistics are analyzed through Nastar and alarm data is analyzed through OMStar.

Level 1 data features the maximum width, the minimum depth, and low processing cost.According to output reports, network administrators can know the operating status of networksand rapidly locate potential problems.

Level 1 data cannot be used to locate network problems independently because of low processingability. The detailed reasons are as follows:

l The KPI can provide only performance statistics rather than specific reasons.




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l Some KPIs can indicate the deterioration direction; however, the KPIs alone cannot accountfor the basis of analyzing the specific reasons for network problems. For example, a KPIindicates an increase in the number of call drops. An analysis of the KPIs related to calldrop reveals that call drop is due to SRB reset. The problems, such as poor coverage, uplinkinterference, or untimely handover, may lead to SRB reset.

l Alarm data indicates the problems related to the running of the equipment. Alarm dataincludes the alarms related to the KPIs of the entire network, such as BSC board abnormalityalarm and A interface abnormality alarm, the alarms related to a cell or a BTS, such asfeeder abnormality alarm and Abis transmission disruption alarm.

Performance History RecordsThis describes the Level 2 data. The Level 2 data is mainly the Call History Records (CHRs)and is analyzed by OMStar.

CHRs are oriented to all intra-BSC MSs that meet the preset conditions. Sample tracing isoriented to one or more MSs in a specified cell.

NOTE

CHRs indicate the calling procedure information, such as the signaling procedure status before call drops,measurement report information reported before call drops, and signal status during access to the network.

Compared with the performance statistics, performance history records decrease in width butincrease in depth. Level 2 data can help network operators to locate general performanceproblems and to handle most of the complaints.

Tracing and Monitoring DataThis describes the Level 3 data. The Level 3 data is mainly single MS tracing data and drive testdata. The Signal Analyze Tool can be used to analyze single MS data and Probe can be used tocollect the drive test data.

NOTEProbe helps to collect drive test data. Assistant helps to process drive test data and single UE tracing data.

The main differences between single MS tracing data and drive test data are as follows:

l During a single MS tracing, the messages at the network side are traced. The measurementresults reported by the BTS and the messages on the interfaces, such as A interface, Abisinterface, and Um interface can be traced.

l During a drive test, an MS is tested and its detailed information is recorded. The informationincludes the transmit power of the MS, the receiving level and receiving quality measuredby the MS, handover call drop, and messages on the air interface.

Level 3 data features the maximum depth, the minimum width, and high processing cost. Becauseof low efficiency in data collection, Level 3 data is mainly used for network planners or networkoperators to locate and handle difficult problems. Single MS tracing data and drive test data canbe used to analyze problems.

2.3 Collection and Storage of Performance DataThis describes the principles of performance data collection and storage. In addition, thisdescribes how to collect, store, and provide Level 1 data, Level 2 data, and Level 3 data.



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2.3.1 Principles of Collection and Storage of Performance DataThis describes the principles of performance data collection and storage. Using the M2000, theBSC and BTS collect performance data and store the data on the local server. The performanceanalysis tool accesses the network after being authenticated by the M2000 and collects requireddata. To perform general analysis based on multiple network elements (NEs), you can uploadoriginal data to the FTP server.

2.3.2 Collection of Performance DataThis describes the process of collecting performance data. Different methods are used to collectthe performance data of three levels.

2.3.3 Storage of Performance DataThis topic describes storage of performance data. According to three levels of performance data,you can use three methods of storing performance data.

2.3.4 Provision of Performance DataThis describes provision of performance data. Three methods are used to provide theperformance data of three levels.

2.3.1 Principles of Collection and Storage of Performance DataThis describes the principles of performance data collection and storage. Using the M2000, theBSC and BTS collect performance data and store the data on the local server. The performanceanalysis tool accesses the network after being authenticated by the M2000 and collects requireddata. To perform general analysis based on multiple network elements (NEs), you can uploadoriginal data to the FTP server.

Figure 2-4 shows the level structure of performance management.

Figure 2-4 Hierarchical structure of performance management

M2000 Server

OMU

BSC

Client

LMT

FTP

GUI

}Performancedata storage

}Performancedata collection

SMU SMU SMU

l Boards make statistics of performance data.

l BAM collects and saves performance data.




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l The M2000 provides the functions for setting and querying performance KPIs.

l The intelligent report system generates the performance KPI report.

2.3.2 Collection of Performance DataThis describes the process of collecting performance data. Different methods are used to collectthe performance data of three levels.

Collection of Performance StatisticsLevel 1 data includes performance statistics and alarm data.

l Performance statistics are automatically collected by equipment. The minimum reportinggranularity is five minutes. The default reporting granularity is 30 minutes. The collectiongranularity can be set to 5, 15, 30, 60, and 1440 minutes on the M2000. All of the reporteddata are stored on the BSC GBAM/GOMU server. The GBAM/GOMU server reportsperformance statistics to the M2000.

l For details of alarm data collection, refer to the manuals related to operation andmaintenance, such as the BSS Routine Maintenance Guideline.

Collection of Performance History RecordsLevel 2 data are CHRs and sample tracing data.

l By default, abnormal calls are recorded in CHR files.

l Starting the sample tracing function on the BSC LMT, you can control the collection oftracing data. The data that can be controlled are collected data, such as the signalingmessages on standard interfaces, measurement results, and internal messages, and samplingscope.

Collection of Tracing and Monitoring DataLevel 3 data includes drive test data, single MS tracing data, interface tracing data, and linkperformance tracing data.

l For details of drive test data collection, refer to the BSS Radio Network OptimizationGuideline.

l To collect single MS tracing data and interface tracing data, start the tracing function onthe BSC LMT. The data that can be controlled are the messages on standard interfaces, theIMSIs of MSs, and cells.

l To collect link performance tracing data, start the tracing function on the BSC LMT. Thedata that can be controlled includes link performance data, such as MS transmit power andBlock Error Rate (BLER).

2.3.3 Storage of Performance DataThis topic describes storage of performance data. According to three levels of performance data,you can use three methods of storing performance data.

Storage of Performance StatisticsLevel 1 data is performance statistics and alarm data.



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l The alarm data is saved to the directory \\aaa.bbb.ccc.ddd\bsc6000\data\mtndata\alm.

l By default, performance statistics are stored in the directory \\aaa.bbb.ccc.ddd\bsc6000\data\mtndata\pfm\rslt.

NOTE

In the directory, aaa.bbb.ccc.ddd indicates the IP address of the GBAM/GOMU.

NOTE

You can download performance measurement results through the M2000 or the Performance Browser Tool. Todownload the BSC6000 performance measurement results, use the following methods:

l Download measurement results through FTP. Choose System > Download Measurement Results. Theperformance measurement results are saved to the directory \export\home\sysm\ftproot\pm.

l Copy the performance measurement results from \\aaa.bbb.ccc.ddd\bsc6000\data\mtndata\pfm\rslt into\HW LMT\adaptor\clientadaptor\pfbTool\data.

l Change the name of the performance measurement result file so that the source directory \\aaa.bbb.ccc.ddd\bsc6000\data\mtndata\pfm\rslt is changed.

Performance statistics are stored on the GBAM/GOMU in binary format for the minimum of three days. Thename of the statistic file consists of the date, start time, end time, and time zone when the statistics are recorded.

Storage of Performance History Records

Level 2 data consist of CHRs and sample tracing data.

l By default, CHRs are stored in the directory \\aaa.bbb.ccc.ddd\bsc6000\data\mtndata\log\dbg\chrlog. You can obtain the CHRs through FTP.

l Sample tracing data is stored in the terminal computer on which the tracing is started. Youcan set the name of the sampling data file and set the directory for saving the sampling data.The default directories are as follows:

– The BSSAP messages on the A interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\ABssap\.

– The SSCP messages on the A interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\ASccp\.

– The MTP3 messages on the A interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\AMtp3\.

– The MTP2 messages on the A interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\AMtp2\.

– The RSL messages on the Abis interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\AbisRsl\.

– The OML messages on the Abis interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\AbisOml\.

– The ESL messages on the Abis interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\AbisEsl\.

– The LAPD messages on the Abis interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\AbisLapd\.

– The application messages on the Pb interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\PbApp\.

– The LAPD messages on the Pb interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\PbLapd\.




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– The messages on the Um interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\Um\.

– The user messages are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\User\.

– The messages on the BSC-CBC interface are saved to \HW LMT\BSC6000\BSC6000V900R008C01\BscObj\ddd\Trc\BscCbc\.

Storage of Tracing and Monitoring DataLevel 3 data includes drive test data, single MS tracing data, interface tracing data, and linkperformance tracing data.

l Drive test data are stored on the operated computer.

l Other data is saved to the BSC LMT directory. The default directories are as follows:– The BSSAP messages on the A interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\ABssap\.– The SSCP messages on the A interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\ASccp\.– The MTP3 messages on the A interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\AMtp3\.– The MTP2 messages on the A interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\AMtp2\.– The RSL messages on the Abis interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\AbisRsl\.– The OML messages on the Abis interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\AbisOml\.– The ESL messages on the Abis interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\AbisEsl\.– The LAPD messages on the Abis interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\AbisLapd\.– The application messages on the Pb interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\PbApp\.– The LAPD messages on the Pb interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\PbLapd\.– The messages on the Um interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\Um\.– The user messages are saved to \HW LMT\BSC6000\BSC6000V900R008C01

\BscObj\ddd\Trc\User\.– The messages on the BSC-CBC interface are saved to \HW LMT\BSC6000

\BSC6000V900R008C01\BscObj\ddd\Trc\BscCbc\.

2.3.4 Provision of Performance DataThis describes provision of performance data. Three methods are used to provide theperformance data of three levels.

The requirements for performance data provided for the Nastar tool are described as follows:

l Specific formats and interfaces of data



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l Corresponding data based on the conditions, including the report mode, data type,granularity, time segment, and object

Provision of Performance StatisticsThe performance statistics stored on the GBAM/GOMU server can be imported directly toNastar for analysis.

Data can be queried according to measurement time, measurement objects, and measurementcounters.

Provision of Performance History RecordsThe functions of OMStar analyze the CHRs.

Provision of Tracing and Monitoring DataAll tracing data are stored and analyzed in file format.

The tool for analyzing drive test data is determined by the terminal type. The single MS tracingdata and standard interface tracing data can be analyzed by SignalTool.




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3 Evaluation of Routine Network Performance

About This Chapter

This describes routine network performance evaluation that is implemented through the analysisof routine reports.

3.1 Introduction to Evaluation of Routine Network Performance EvaluationThis describes routine network performance evaluation that involves periodic obtaining ofnetwork KPIs, analysis of network problems, and analysis of KPI variations.

3.2 Items and Evaluation of Routine Network Performance MonitoringThis describes the items and evaluation of routine performance monitoring. The routineperformance monitoring collects statistics of network KPIs through performance data andconfiguration data, and analyzes the abnormal counters. Therefore, you can instantly know therunning status of the entire network. Routine reports are daily reports, weekly reports, monthlyreports, check reports of RNP parameters, and network monitoring reports.

3.3 Routine Network Performance Monitoring Report ReferenceThis describes the routine network performance monitoring report that lists KPIs, such asaccessibility, call drops, handover success rate, and traffic performance, in the BSC trafficstatistics. The various reports for different users help to monitor the quality of the radio network.

HUAWEI BSC6000 Base Station SubsystemBSS Performance Management Guidelines 3 Evaluation of Routine Network Performance


3-1

3.1 Introduction to Evaluation of Routine NetworkPerformance Evaluation

This describes routine network performance evaluation that involves periodic obtaining ofnetwork KPIs, analysis of network problems, and analysis of KPI variations.

Routine network performance evaluation is implemented with the help of routine reports.

Routine reports are provided for network administrators and network operators to periodicallyobtain network KPIs and their variation for monitoring the network quality.

3.2 Items and Evaluation of Routine Network PerformanceMonitoring

This describes the items and evaluation of routine performance monitoring. The routineperformance monitoring collects statistics of network KPIs through performance data andconfiguration data, and analyzes the abnormal counters. Therefore, you can instantly know therunning status of the entire network. Routine reports are daily reports, weekly reports, monthlyreports, check reports of RNP parameters, and network monitoring reports.

3.2.1 Daily Report of Routine Network Performance MonitoringThis describes the daily report that is provided for network operators to monitor networkperformance. At the early stage of network operation, you must know the operating status of thenetwork at short intervals. Daily reports can be used to detect and locate certain networkproblems.

3.2.2 Weekly Report of Routine Network Performance MonitoringThis describes the weekly report that is provided for network operators to know the variationtrend of network performance on a regular basis and to analyze and optimize the KPIs withdegradation trends. It focuses on the variation trend of each KPI.

3.2.3 Monthly Report of Routine Network Performance MonitoringThis describes the monthly report that involves the variation trends of main KPIs and the KPIsin a month.

3.2.4 RNP Parameter VerificationThis describes RNP parameter verification. The RNP parameters are provided for networkplanners to check the configuration of radio network parameters and to rapidly locate theproblems of frequency parameter configuration.

3.2.1 Daily Report of Routine Network Performance MonitoringThis describes the daily report that is provided for network operators to monitor networkperformance. At the early stage of network operation, you must know the operating status of thenetwork at short intervals. Daily reports can be used to detect and locate certain networkproblems.

Generation Mode

Performance statistics are imported to Nastar in offline mode.

3 Evaluation of Routine Network PerformanceHUAWEI BSC6000 Base Station Subsystem



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The performance data is saved at \\aaa.bbb.ccc.ddd\bsc6000\data\mtndata\pfm\rslt. In thepath, aaa.bbb.ccc.ddd indicates the IP address of the GBAM/GOMU server.

ContentThe daily report includes the evaluation of the KPIs of the entire network and the evaluation ofvery important cells (VICs).

l Evaluation of the entire network: Indicates the running status of the network in a day bycollecting statistics of network KPIs and resource utilization KPIs.

l TopN: Indicates the worst N cells by ranking the main KPIs.

l VIC: Indicates the service quality of the very important cells (VICs) in every day byanalyzing network KPIs and providing precautions.

l Hot cell: Indicates the cells with high traffic volume.

l List of extra busy cells and idle cells: Indicates the extra busy cells and extra idle cells inthe local network.

l Trend figure of 24-hour traffic volume: Indicates the total traffic volume every hour andproviding the 24-hour trend figure.

l Trend figure of other KPIs: Indicates the trend of KPIs every hour in a day.

Components of a SheetFigure 3-1 shows the KPI sheet in a daily report generated by Nastar.

Figure 3-1 KPI sheets in a daily report

Table 3-1 describes the sheets in a daily report.



3-3

Table 3-1 Sheets in a daily report

Sheets in aDaily Report

Name Function Description

KPI List of KPIs Provides the KPIs ofeach BSC and theentire network.

KPI monitoring: Pays moreattention to red unsatisfiedKPIs. The busy hour mustbe set to one hour. If userschoose 24 hours, statisticsof KPIs in 24 hours aredisplayed.

BSC_TopN Top N Cell in aBSC

Indicates the worstN cells according tothe busy-hour KPIsor 24-hour KPIs andarranges the cells inan ascending order.

In general, N is set to 10 bydefault. You can set N andspecific conditions in theAdvanced Settings. Thebusy hour must be set to onehour. If users choose 24hours, statistics of KPIs in24 hours are displayed.

VIC List of KPIs ofVICs

Makes statistics ofthe KPIs ofimportant cells.

The busy hour must be set toone hour. If users choose 24hours, statistics of KPIs in24 hours are displayed.

Hot Cell Hot cell Indicates the busiestten cells of the entirenetwork, arrangesthe cells in adescending order,and displays theassociated KPIs.

If the cell is a VIC, the cellis displayed with abackground color of lightyellow. The busy hour mustbe set to one hour. If userschoose 24 hours, statisticsof KPIs in 24 hours aredisplayed.

Extra Busy_Idle Extra Busy andExtra Idle Cells

Indicates the extrabusy and extra idlecells of the entirenetwork anddisplays theassociated KPIs.

Extra Busy Cell: A cell withhigher than 0.6 Erl trafficvolume per thread

Extra Idle Cell: A cell withlower than 0.1 Erl trafficvolume per thread





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Worst Cell Worst cell Indicates the worstcell of the entirenetwork anddisplays theassociated KPIs.

Worst cell: When the TCHtraffic per thread is higherthan 0.1 Erl, the cells thathave a TCH Call Drop Rateof higher than 3% or a TCHCongestion Rate (includinghandovers) higher than 5%are the worst cells.


BSS Call SetupSuccess RateTrend


Indicates the CallSetup Success RateTrends of the entirenetwork and a BSCin a day.

-

Call Drop RateTrend

Call Drop RateTrend

Indicates the CallDrop Rate Trends ofthe entire networkand a BSC in a day.

-

TCH CongestionRate Trend

TCH CongestionRate Trend

Indicates the TCHCongestion RateTrends of the entirenetwork and a BSCin a day.

-

SDCCHCongestion RateTrend


Indicates theSDCCH CongestionRate Trends of theentire network and aBSC in a day.

-

BSC HandoverSuccess RateTrend

HandoverSuccess RateTrend

Indicates theHandover SuccessRate Trends of theentire network and aBSC in a day.

-

TCH TrafficTrend

Traffic VolumeTrend

Indicates the TrafficVolume Trends ofthe entire networkand a BSC in a day.

-

TCH UsabilityTrend

TCH UsabilityTrend

Indicates the TCHUsability Trends ofthe entire networkand a BSC in a day.

-



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SDCCH UsabilityTrend

SDCCHUsability Trend

Indicates theSDCCH UsabilityTrends of the entirenetwork and a BSCin a day.

-

BSC Percentageof CPU Trend

CPU Load Trend Indicates the CPUutilization of a BSCin a day.

-

Evaluation and AnalysisThe KPIs in the KPI sheet are analyzed according to accessibility, Call Drop Rate (CDR), andmobility.

NOTE

The reference values of the following KPIs serve only for reference.

Table 3-2 provides the evaluation and analysis of the accessibility KPIs.

Table 3-2 Evaluation and analysis of the accessibility KPIs

KPI Description ReferenceValue

Evaluation and Analysis

Success rate ofimmediateassignment

This is an analysiscounter. In animmediateassignmentprocedure, an MSreports severalChannel Requestmessages and onlyone EstablishIndicationmessage. Thus,this counter cannotindicate immediateassignmentfailures.

97% If this KPI is obviously lower than97%, it is an indication that theaccess success rate is low andtherefore optimization is required.

The main reasons are poorcoverage, improper settings ofpower parameters, and networkcongestion.

Optimize RF, adjust powersettings, and expand networkcapacity.

Success rate ofTCHassignment

Indicates the TCHusage.





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KPI Description ReferenceValue


The main causes are poor coverage,unsuccessful handover, insufficientresources, and equipmentproblems.

Enhance coverage, expand networkcapacity, and adjust parameters.

TCH SeizureSuccess Rate

Indicates the TCHusage.




BSS CallEstablishmentSuccess Rate

Indicates the BSScall setup successrate.




Table 3-3 provides the evaluation and analysis of the CDR KPIs.

Table 3-3 Evaluation and analysis of the CDR KPIs

KPI Description Reference Value Evaluation and Analysis

Intra-BSCHandoverSuccess Rate

Indicatesperformance ofthe intra-BSChandoverattempts in thenetwork.

94% If this KPI is obviously lower than94%, it is an indication thatperformance of intra-BSChandover is lowered and thatoptimization is required.



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The main causes are untimelyhandover due to improperhandover parameter settings,improper configuration ofneighboring cells, poor coverage,insufficient resources, andequipment problems.

Optimize handover parameters oranalyze equipment alarms.

Intra-BSCRadioHandoverSuccess Rate

Indicatesperformance ofthe intra-BSChandover in thenetwork.

95% If this KPI is obviously lower than95%, it is an indication thatperformance of intra-BSChandover is lowered, whichaffects user satisfaction.

The main causes are improperdata configuration, neighboringcell configuration, and handoverparameter settings.

Check network configuration andsystem alarms.

ExternalOutgoingCellHandoverSuccess Rate

Indicatesperformance ofthe outgoingBSC handoverattempts in thenetwork.

94% If this KPI is obviously lower than94%, it is an indication thatperformance of inter-BSChandover is lowered, whichaffects user satisfaction.



ExternalOutgoingCell RadioHandoverSuccess Rate

Indicatesperformance ofthe outgoingBSC handover inthe network.







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Success Rateof IncomingExternalInter-CellHandover

Indicatesperformance ofthe incomingBSC handoverattempts in thenetwork.




ExternalIncomingCell RadioHandoverSuccess Rate

Indicatesperformance ofthe incomingBSC handoversin the network.




Dual-BandHandoverSuccess Rate(900M/850M-1800M/1900M)

Indicatesperformance ofthe handoverfrom 900 MHzcells to 1800MHz cells in thenetwork.

94% If this KPI is obviously lower than94%, it indicates that performanceof the handover between dual-band networks is lowered, whichaffects user satisfaction.



Dual-BandHandoverSuccess Rate(1800M/1900M-900M/850M)

Indicatesperformance ofthe handoverfrom 1800 MHzcells to 900 MHzcells in thenetwork.

94% If this KPI is obviously lower than94%, it is an indication thatperformance of the handoverbetween dual-band networks islowered, which affects usersatisfaction.




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Table 3-4 provides the evaluation and analysis of the mobility KPIs.

Table 3-4 Evaluation and analysis of the mobility KPIs

KPI Description

ReferenceValue


TCH CallDrop Rate(IncludingHandover)

Indicates thelinkretainabilityof TCHservices(includinghandovers).

1.20% If this KPI is obviously higher than 1.2%, it isan indication that the service retainability ispoor and therefore optimization is required.

The main causes are poor coverage,unsuccessful handover, insufficient resources,and equipment problems.

Adjust the network according to specificconditions.

TCH CallDrop Rate(ExcludingHandover)

Indicates thelinkretainabilityof TCHservices.




Call droprate onSDCCH

Indicates thelinkretainabilityof SDCCHservices.




TCHRadioLoss Rate

Indicates theretainabilityof TCHservices onradio links.


The main causes are poor coverage,insufficient resources, and equipmentproblems.




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KPI Description

ReferenceValue



TCHHandoverLoss Rate

Indicates theretainabilityof TCHservicesduringhandovers.




Trafficcall droprate

Indicates theratio of thetrafficvolume tothe call dropsand theretainabilityof thenetwork.

110 If this KPI is obviously lower than 110, it is anindication that the service retainability is poorand therefore optimization is required.


3.2.2 Weekly Report of Routine Network Performance MonitoringThis describes the weekly report that is provided for network operators to know the variationtrend of network performance on a regular basis and to analyze and optimize the KPIs withdegradation trends. It focuses on the variation trend of each KPI.

Generation Mode



Content

A weekly report has the following contents:

l Variation trend of the main KPIs of the network in a week

l Causes of problems and problem distribution areas

Components of a Sheet

Figure 3-2 shows the KPI sheet in a weekly report generated by Nastar.



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Figure 3-2 KPI sheet in a weekly report

Table 3-5 describes the items of the monitoring report for comparison.

Table 3-5 Sheets in a weekly report

Sheets in aWeeklyReport


KPI List of KPIs Provides the KPIs ofeach BSC and theentire network.

KPI monitoring: Pays moreattention to red unsatisfied KPIs.The busy hour must be set to onehour. If users choose 24 hours,statistics of KPIs in 24 hours aredisplayed.

BSC_TopN Top N Cell ina BSC

Indicates the worstN cells according tothe average of a KPIin seven days andarranges the cells inan ascending order.In general, N is set to10 by default. Youcan set N (minimum:0; maximum: 50) inthe AdvancedSettings.

In general, N is set to 10 bydefault. You can set N andspecific conditions in theAdvanced Settings. The busyhour must be set to one hour. Ifusers choose 24 hours, statisticsof KPIs in 24 hours are displayed.

VIC List of KPIs ofVICs

Makes statistics ofthe KPIs ofimportant cells.

The VICs are defined by users.




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Sheets in aWeeklyReport



BSS CallSetup SuccessRate Trend

Indicates the CallSetup Success RateTrends of the entirenetwork and a BSCin a week.

The horizontal coordinaterepresents time and has 7 x 24points. You can choose busyhours or 24 hours.

Call Drop RateTrend

Call DropRate Trend

Indicates the CallDrop Rate Trends ofthe entire networkand a BSC in a week.


TCHCongestion RateTrend

TCHCongestionRate Trend

Indicates the TCHCongestion RateTrends of the entirenetwork and a BSCin a week.



SDCCHCongestionRate Trend

Indicates theSDCCH CongestionRate Trends of theentire network and aBSC in a week.


BSC HandoverSuccess RateTrend

HandoverSuccess RateTrend

Indicates theHandover SuccessRate Trends of theentire network and aBSC in a week.


TCH TrafficTrend

TrafficVolume Trend

Indicates the TrafficVolume Trends ofthe entire networkand a BSC in a week.


TCH UsabilityTrend

TCHUsabilityTrend

Indicates the TCHUsability Trends ofthe entire networkand a BSC in a week.


SDCCHUsability Trend

SDCCHUsabilityTrend

Indicates theSDCCH UsabilityTrend of the entirenetwork and a BSCin a week.


BSC Percentageof CPU Trend

CPU LoadTrend

Indicates the CPUutilization of a BSCin a week.




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Evaluation and AnalysisThe evaluation of the KPIs in the KPI sheet is the same as the KPI sheet in the daily report. Fordetails, refer to the 3.2.1 Daily Report of Routine Network Performance Monitoring.

Other sheets provide the variation trend of each KPI in a week. If the KPIs are degraded, referto the 3.2.1 Daily Report of Routine Network Performance Monitoring for handlingsuggestions to optimize the network.

3.2.3 Monthly Report of Routine Network Performance MonitoringThis describes the monthly report that involves the variation trends of main KPIs and the KPIsin a month.

The functions and contents of monthly report are the same as those of weekly report. For details,refer to the 3.2.2 Weekly Report of Routine Network Performance Monitoring.

3.2.4 RNP Parameter VerificationThis describes RNP parameter verification. The RNP parameters are provided for networkplanners to check the configuration of radio network parameters and to rapidly locate theproblems of frequency parameter configuration.

Generation ModePerformance statistics are imported to Nastar in offline mode.


ContentThe contents of the RNP parameter verification are as follows:

l Channel Check

l List of problem cells

l Neighboring cells

l Co-BCCH Co-BSIC

Components of a SheetFigure 3-3 shows a sheet of the RNP parameter verification by Nastar.




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Figure 3-3 A sheet of RNP parameter verification

Table 3-6 describes the items of the RNP parameter verification by Nastar V200R004C02.

Table 3-6 Items and functions of the RNP parameter verification

Sheets of theRNPParameterVerification


Overview Overview Displays all the checked RNPparameters in chart mode.

Makes the statisticsof function items.

ARFCNUtilizationCheck

ARFCNUtilizationCheck

Checks the occupied networkfrequencies and displays theutilization of each frequency.

Checks the RNPparameters of theserving BSC.

Problem-CellList

List ofproblemcells

Checks the grade of the minimumreceived signal of the MS in a cell.

Displays thesuggested values andhealth ranges andindicates theincorrect values.

Config. DataCheck

Configuration Data Check

Checks the configurationparameters of cells and displaysdifferent colors to highlightimproper counters.

Checks theconfigurationparameters of cellsand displays theconfiguration ofimproper parametersthat are not inaccordance withsuggested values.



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Sheets of theRNPParameterVerification


Channel Check ChannelCheck

Checks the co-channel andadjacent-channel cells, co-channel neighboring cells, andadjacent-channel neighboringcells.

Displays the basicinformation of theoriginating cell andtarget cell and thedistance between thetwo cells.

Co-BCCH Co-BSIC Check

Co-BCCHCo-BSICCheck

Checks the Co-BCCH Co-BSICcells and provides the associatedlists.


Co-BCCH &Co-BSIC (Neb)

Co-BCCH &Co-BSIC(Neb)

Checks the Co-BCCH & Co-BSIC in the serving cell and theneighboring cells and the Co-BCCH & Co-BSIC in theneighboring cells.


Single Nebs(Network)

Single Nebs(Network)

Checks the unidirectionalneighboring cells in the entirenetwork.

Displays all the cellsthat are configuredwith unidirectionalneighboring cellsand judges whetherthe cells are internalcells.

Cells with FewerNeighbor Check

Cells withFewerNeighborCheck

Checks whether neighboring cellsare inadequate. The default number

is 4. The number canbe modified.

Far NeighborCheck

Far NeighborCheck

Checks whether neighboring cellsare too far.

Sets the distances ofover-far neighboringcells. The defaultvalue is 20 km [12.4miles].

3.3 Routine Network Performance Monitoring ReportReference

This describes the routine network performance monitoring report that lists KPIs, such asaccessibility, call drops, handover success rate, and traffic performance, in the BSC trafficstatistics. The various reports for different users help to monitor the quality of the radio network.




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3.3.1 Routine Network Performance Monitoring Report (for Engineers)This describes the monitoring report of routine network performance output for engineers. Themonitoring report is used in analyzing KPIs for monitoring the network performance.

3.3.2 Routine Network Performance Monitoring Report (for Project Managers)This describes the monitoring report of routine network performance output for projectmanagers. The monitoring report is used in analyzing KPIs for monitoring the networkperformance.

3.3.3 Routine Network Performance Monitoring Report (for Comparison)This describes the monitoring report of routine network performance output for comparison.The monitoring report is used in analyzing KPIs for monitoring the network performance.

3.3.1 Routine Network Performance Monitoring Report (forEngineers)

This describes the monitoring report of routine network performance output for engineers. Themonitoring report is used in analyzing KPIs for monitoring the network performance.

Generation Mode



Examples

Figure 3-4 shows a sheet of the monitoring report for engineers by Nastar.

Figure 3-4 A sheet of the monitoring report for engineers



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Item DescriptionTable 3-7 describes the items of the monitoring report for engineers by Nastar V200R004C02.

Table 3-7 Items of the monitoring report for engineers

Sheets oftheMonitoringReport forEngineers


Cover Cover Lists the information, such asengineering names, BSC ID,BSC IP, number of BTSs,number of TRXs or cells,versions, and engineeringimplementation stages, of theBSC. Displays the statisticdate, time scope, and statisticmode of the report. Makes thestatistics of KPIs within thestatistic date.

—

BSC KPI BSC KPI Provides the analysis of thetrends of KPIs within thestatistic date. Lists the historyrecords of KPIs andcorresponding trend figures.

The statistics can becollected by day orhour.

Cell KPITOPNINDEX

Cell KPI TOPNINDEX

Displays top 10 TRXs or cellswith exceptional KPIs. If acell is also a VIC, it is marked.The arrangement isimplemented on the basis ofthe first KPI in a sheet. Youcan click links to know thedetails of the correspondingKPIs.

—

Accessibility Accessibility Analyzes top N TRXs or cellswith exceptionalAccessibility. If a cell is alsoa VIC, it is marked. Theanalysis items involve failurecauses, services, and flows.

—

Mobility Mobility Analyzes top N TRXs or cellswith exceptional Mobility. Ifa cell is also a VIC, it ismarked. The analysis itemsinvolve failure causes,services, and flows.

—




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Sheets oftheMonitoringReport forEngineers


Retainability Retainability Analyzes top N TRXs or cellswith exceptionalRetainability. If a cell is alsoa VIC, it is marked. Theanalysis items involve failurecauses, services, and flows.

—

ResourceUtilization

ResourceUtilization

Analyzes top N TRXs or cellswith exceptional ResourceUtilization. If a cell is also aVIC, it is marked. Theanalysis items involve failurecauses, services, and flows.

—

VIC KPI VIC KPI Makes the statistics of all theKPIs of each VIC or TRX. —

Readme Readme Defines the good thresholdsand qualified thresholds ofKPIs and the display modesof actual KPIs on the basis ofeach threshold. Displays thedefinition of exceptionalarms. You can setthresholds throughconfiguration files.

—

Evaluation and AnalysisThe evaluation of the KPIs in the KPI sheet in the routine network performance monitoringreport for engineers is the same as the KPI sheet in the daily report. For details, refer to the 3.2.1Daily Report of Routine Network Performance Monitoring.


3.3.2 Routine Network Performance Monitoring Report (for ProjectManagers)

This describes the monitoring report of routine network performance output for projectmanagers. The monitoring report is used in analyzing KPIs for monitoring the networkperformance.



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ExamplesFigure 3-5 shows a sheet of the monitoring report for project managers by Nastar.

Figure 3-5 A sheet of the monitoring report for project managers

Item DescriptionTable 3-8 describes the items of the monitoring report for project managers by NastarV200R004C02.




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Table 3-8 Items of the monitoring report for project managers

Sheets oftheMonitoring Reportfor ProjectManagers


Cover Cover Lists the information, such asengineering names, BSC ID,BSC IP, number of BTSs,number of TRXs or cells,versions, and engineeringimplementation stages, of theBSC. Displays the statistic date,time scope, and statistic mode ofthe report. Makes statistics ofKPIs within the statistic date.

—

BSC KPI BSC KPI Provides the analysis of thetrends of KPIs within the statisticdate. Lists the history records ofKPIs and corresponding trendfigures.

The statistics can bemade by day orhour.

Readme — Defines the good thresholds andqualified thresholds of KPIs andthe display modes of actual KPIson the basis of each threshold.Displays the definition ofexception alarms. You can setthresholds through configurationfiles.

—


The evaluation of the KPIs in the KPI sheet in the routine network performance monitoringreport for comparison is the same as the KPI sheet in the daily report. For details, refer to the3.2.1 Daily Report of Routine Network Performance Monitoring.


3.3.3 Routine Network Performance Monitoring Report (forComparison)

This describes the monitoring report of routine network performance output for comparison.The monitoring report is used in analyzing KPIs for monitoring the network performance.



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ExamplesFigure 3-6 shows a sheet of the monitoring report for engineers by Nastar.

Figure 3-6 KPI sheet in a weekly report

Item DescriptionTable 3-9 describes the items of the monitoring report for comparison.




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Table 3-9 Items of the monitoring report for comparison

Sheets oftheMonitoringReport forComparison


Cover Cover Displays the information,such as engineering names,BSC ID, BSC IP, number ofBTSs, number of TRXs orcells, versions, andengineering implementationstages, of the BSC.

Displays thecomparison values ofKPIs in different timesegments.

Displays the statistic date,time scope, and statistic modeof the report.

Displays statistics of KPIswithin the statistic date. Youcan click links to know thedetails of the correspondingKPIs.

BSC KPI BSC KPI Provides the analysis of thetrends of KPIs within thestatistic date. Lists the historyrecords of KPIs andcorresponding trend figures.

The statistics can bemade by day or hour.

Readme — Defines the good thresholdsand qualified thresholds ofKPIs and the display modes ofactual KPIs on the basis ofeach threshold. Displays thedefinition of exceptionalarms. You can setthresholds throughconfiguration files.

—

Evaluation and AnalysisThe evaluation of the KPIs in the KPI sheet in the routine network performance monitoringreport for comparison is the same as the KPI sheet in the daily report. For details, refer to the3.2.1 Daily Report of Routine Network Performance Monitoring.




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4 Analysis and Optimization of NetworkPerformance

About This Chapter

This describes network performance analysis and optimization that involve the general policyof performance problem analysis, traffic statistics analysis, optimization against missing co-channel neighboring cell configuration, optimization against call drops, optimization againstinterference, optimization of paging success rate, optimization against low mean opinion score(MOS), optimization of handover success rate, and optimization of network coverage.

4.1 Introduction to Analysis and Optimization of Network PerformanceThis describes performance analysis and optimization that are performed in the running,maintenance, and optimization of the network. The main tasks are problem diagnosis, problemlocation, trend analysis, and optimization.

4.2 Performance Analysis ProcessThis describes the performance analysis process, which consists of three levels: Level 1, Level2, and Level 3.

4.3 Performance Statistics AnalysisThis describes the performance statistics analysis, which is performed after the networkequipment is constructed and initial network optimization. The initial network optimizationhelps to solve the problems of main engineering parameters. The problems include blind points,antenna misconnection, missing configuration of some neighboring cells, and equipmentunavailability. On this basis, performance statistics and network KPIs are analyzed to guide thesubsequent network optimization.

4.4 Optimization Against Missing Neighboring Cell ConfigurationThis describes optimization against missing neighboring cell configuration. The optimizationaims to reduce the cell call drop rate and improve the cell handover success rate.

4.5 Optimization Against Call Drop RateThis describes the optimization against call drop rate. The optimization aims to reduce the calldrop rate and improve the network quality.

4.6 Optimization Against InterferenceThis describes optimization against interference. The optimization aims to reduce interference,intensify the reuse of frequencies, and thus improve the system capacity.

HUAWEI BSC6000 Base Station SubsystemBSS Performance Management Guidelines 4 Analysis and Optimization of Network Performance


4-1

4.7 Optimization Against Low Paging RateThis describes optimization against low paging rate. The optimization aims to improve thepaging success rate and user satisfaction.

4.8 Optimization Against Low MOSThis describes the optimization against low MOS. The optimization aims to increase the MOSvalue.

4.9 Optimization Against Low Handover RateThis describes the optimization against low handover rate. The optimization aims to increasethe handover rate and improve the network quality.

4.10 Optimization Against Poor Network CoverageThis describes the optimization against poor network coverage. The optimization aims to reducethe excessive coverage, insufficient coverage, or unbalanced coverage of the network andimprove the network quality.

4 Analysis and Optimization of Network PerformanceHUAWEI BSC6000 Base Station Subsystem



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4.1 Introduction to Analysis and Optimization of NetworkPerformance

This describes performance analysis and optimization that are performed in the running,maintenance, and optimization of the network. The main tasks are problem diagnosis, problemlocation, trend analysis, and optimization.

Problem Diagnosis and LocationProblem diagnosis and location refer to analyzing and locating existing network faults andquality degradation problems.

In routine monitoring, the KPIs of the network are monitored. When some KPIs are founddegraded, you must troubleshoot the problems to improve the KPIs.

Trend Analysis and OptimizationThe purposes of trend analysis and optimization are to forecast the trend of the networkperformance in a period of time and to take optimization measures to solve potential problems.

4.2 Performance Analysis ProcessThis describes the performance analysis process, which consists of three levels: Level 1, Level2, and Level 3.

The data to be analyzed at three levels is derived from that defined in 2.2.2 Classification ofthe BSS Performance Data.

Level 1, Level 2, and Level 3 are divided according to the operations for different problems.Generally, problem analysis is performed at Level 1. If the problem cannot be located, moreperformance data need to be input for Level 2 analysis. If the problem still cannot be solved,Level 3 analysis is performed until the problem is solved.

4.2.1 Performance Statistics Analysis ProcessThis describes the process of analyzing performance statistics. The performance statistics dataare used as the input for analysis. It helps network operators to analyze problems.

4.2.2 Performance History Records Analysis ProcessThis describes the process of analyzing the performance history records. The performancehistory records are used as the input for analysis. It helps network operators to isolate and locatecommon performance problems and to handle complaints.

4.2.3 Tracing and Monitoring Data Analysis ProcessThis describes the process of analyzing the tracing and monitoring data. The tracing andmonitoring data are used as the input for analysis. It helps network operators to solve variousdifficult problems.

4.2.1 Performance Statistics Analysis ProcessThis describes the process of analyzing performance statistics. The performance statistics dataare used as the input for analysis. It helps network operators to analyze problems.

Figure 4-1 shows the process of analyzing performance statistics.



4-3

Figure 4-1 Performance statistics analysis process

Analyze KPIs of topN cells

Analyze BSCequipment problems

Network KPIanalysis

Analyze cellequipment problems

Solve BSCequipment problems

Solve cell equipmentproblems

Is any KPI degraded?

Any equipmentproblems?

Any cell equipmentproblems?

Any load problems?

Cell performancestatistics

BSC and BTSalarms

A

Networkperformance

statistics

Performancestatistics and alarm

data

Yes

Yes

Yes

No

No

No

Start

EndNo

Solve load problemsYes

A1

A: corresponds to Step A in the process of analyzingthe performance history records.

A1: corresponds to Step A1 in the process of analyzingthe performance history records.




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4.2.2 Performance History Records Analysis ProcessThis describes the process of analyzing the performance history records. The performancehistory records are used as the input for analysis. It helps network operators to isolate and locatecommon performance problems and to handle complaints.

Figure 4-2 shows the process of analyzing the performance history records.



4-5

Figure 4-2 Performance history records analysis process

A1

Analyze coverageproblems

Analyze interferenceproblems

Any interferenceproblems?

Any coverageproblems?

A

CHR, TRX frequencyscanning, interference

band distribution

Solve coverageproblems

Analyze parameterproblems

Anyterminal problems?

Any parameterproblems?

Analyze terminalproblems

CHR, optimization ofneighboring cell

configuration andparameter configuration

Solve parameterproblems

CHR: terminalperformance

statistics

List of terminaldefects

B

Solve interferenceproblems

Yes

Yes

Yes

Yes

No

No

No

No

CHR, cell signalingtracing; cell

coverage qualityanalysis

A: corresponds to Step A in theprocess of analyzing performancestatistics.

A1: corresponds to Step A1 in theprocess of analyzing performancestatistics.

B: corresponds to Step B in theprocess of analyzing the tracing andmonitoring data.




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4.2.3 Tracing and Monitoring Data Analysis ProcessThis describes the process of analyzing the tracing and monitoring data. The tracing andmonitoring data are used as the input for analysis. It helps network operators to solve variousdifficult problems.

Figure 4-3 shows the process of analyzing the tracing and monitoring data.

Figure 4-3 Tracing and monitoring data analysis process

A1

Analyze and solveproblems

Perform a drive test

B

End

Handovers, calldrops, and IMSI of

the MS

Drive test data andsingle MS tracing

data

End handlingprocess

B: corresponds to Step B in the process of analyzingperformance history records.

A1: corresponds to Step A1 in the process of analyzingperformance history records.

4.3 Performance Statistics AnalysisThis describes the performance statistics analysis, which is performed after the networkequipment is constructed and initial network optimization. The initial network optimizationhelps to solve the problems of main engineering parameters. The problems include blind points,antenna misconnection, missing configuration of some neighboring cells, and equipmentunavailability. On this basis, performance statistics and network KPIs are analyzed to guide thesubsequent network optimization.

4.3.1 Performance Statistics Analysis ProcessThis describes the process of performance statistics analysis.

4.3.2 Collecting the Performance Data of the Current NetworkThis describes the collection of performance data of the current network for performancestatistics analysis.

4.3.3 Generating Reports by the Nastar



4-7

This describes how to generate reports by the Nastar. The Nastar generates various reports basedon the performance statistics of the current network and the corresponding templates.

4.3.4 Analysis of Network KPIsThis analyzes network KPIs. As BSC-oriented KPIs, network KPIs are analyzed to monitor therunning status of the network.

4.3.5 Analysis of Top N CellsThis describes the analysis of top N cells. If some network KPIs exceed or approach presetthresholds, analysis of top N cells is required to locate problem cells and specific causes.

4.3.6 Outputting Solutions or SuggestionsThis describes the solutions and suggestions output after the analysis of network KPIs and topN cells for problem location and network optimization. Then, based on the running status of thenetwork, determine whether to end or continue the optimization.

4.3.1 Performance Statistics Analysis ProcessThis describes the process of performance statistics analysis.

Figure 4-4 shows the process of performance statistics analysis.

Figure 4-4 Performance statistics analysis process

Start

Collect the data of existingnetwork

Use the Nastar to generatereports

Analyze exceptional KPIs ofthe whole network

Analyze TOP N cells

Output solutions orsuggestions

End

The main process is as follows:

1. Collecting the performance data of the current network2. Generating reports by the Nastar3. Anylazing the network KPIs according to the reports Network KPIs refer to BSC-oriented

KPIs, used to monitor the running status of the network. Network KPI analysis has daily




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report analysis, weekly report analysis, monthly report analysis, and network monitoringreport analysis.

4. Analyzing the top N cells If some network KPIs exceed or approach preset thresholds,analysis of top N cells is required to locate problem cells and specific causes. For problemsthat cannot be located, other information such as CHR is required for further analysis.

5. Outputting solutions or suggestions

4.3.2 Collecting the Performance Data of the Current NetworkThis describes the collection of performance data of the current network for performancestatistics analysis.

The performance data of the current network has the following types:

l BGAM/GOMU (performance statistics)

l Local data (performance statistics, BSC configuration, alarms, and engineering files)

4.3.3 Generating Reports by the NastarThis describes how to generate reports by the Nastar. The Nastar generates various reports basedon the performance statistics of the current network and the corresponding templates.

Content of the Performance Statistics ReportThe performance statistics report contains the statistics of related performance counters.

1. According to the measurement object, the following two types of performance statisticsare important:l BSC overall performance measurement (network KPIs can be analyzed)

l Cell measurement (top N cells can be analyzed)

2. According to the indicated network performance, the performance statistics can beclassified into the following types:l Accessibility KPIs

l Mobility KPIs

l Retainability KPIs

l Resource utilization KPIs

Templates for the Performance Statistics ReportThe templates for the performance statistics are the templates for the daily report, weekly report,monthly report, and network monitoring report provided by the Nastar. Nastar can generatevarious reports based on the performance statistics data of the network and the correspondingtemplates.

The following takes a network monitoring report as an example to introduce the contents in thereport.

The network monitoring report is composed of multiple sheets:

l The KPI sheet has BSC-oriented KPIs for the analysis of network KPIs.

l Other sheets have cell-oriented KPIs for the analysis of top N cells.



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To analyze exceptions through the network monitoring report, perform the following steps:

l Locate exceptional BSC-oriented KPIs.

l Analyze the corresponding cell-oriented KPIs.

l Confirm causes.

4.3.4 Analysis of Network KPIsThis analyzes network KPIs. As BSC-oriented KPIs, network KPIs are analyzed to monitor therunning status of the network.

The following takes the network monitoring report in the Nastar V200R004C02 as an example:

Table 4-1 lists the network KPIs.

Table 4-1 Network KPIs

Type KPI

Accessibility KPIs Success rate of immediate assignment

Success rate of TCH assignment

TCH Seizure Success Rate

BSS Call Establishment Success Rate

Mobility KPIs Intra-BSC Handover Success Rate

Intra-BSC Radio Handover Success Rate

External Outgoing Cell Handover Success Rate

External Outgoing Cell Radio Handover Success Rate

External Incoming Cell Handover Success Rate

External Incoming Cell Radio Handover Success Rate

Dual-Band Handover Success Rate (900M/850M–1800M/1900M)

Dual-Band Handover Success Rate (1800M/1900M–900M/850M)

Retainability KPIs TCH Call Drop Rate (Including Handover)

TCH Call Drop Rate (Excluding Handover)

Call Drop Rate on SDCCH

TCH Radio Loss Rate

TCH Handover Loss Rate

Traffic Call Drop Rate

Resource utilizationKPIs

TCH Traffic Volume

SDCCH Traffic Volume




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Type KPI

TCH Congestion Rate (All Channels Busy)

Congestion Rate on SDCCH

TCH Traffic Volume

Half-Rate Traffic

Maximum CPU Usage

NOTE

Generally, the network KPIs are normal; however, some cell-oriented KPIs may be abnormal in a periodof time. These cell-oriented KPIs are the major objects to be analyzed.

4.3.5 Analysis of Top N CellsThis describes the analysis of top N cells. If some network KPIs exceed or approach presetthresholds, analysis of top N cells is required to locate problem cells and specific causes.

A network monitoring report is composed of multiple sheets. The sheets of Cell KPI Top NIndex, Accessibility, Mobility, Retainability, Resource Utilization, and VIC KPI help to analyzecell counters. For example, the Accessibility sheet displays the top 10 cells with worstaccessibility.

4.3.6 Outputting Solutions or SuggestionsThis describes the solutions and suggestions output after the analysis of network KPIs and topN cells for problem location and network optimization. Then, based on the running status of thenetwork, determine whether to end or continue the optimization.

4.4 Optimization Against Missing Neighboring CellConfiguration

This describes optimization against missing neighboring cell configuration. The optimizationaims to reduce the cell call drop rate and improve the cell handover success rate.

4.4.1 Introduction to Missing Neighboring Cell ConfigurationThis describes the missing neighboring cell configuration. This problem frequently arises inconfiguring neighboring cells and may cause high call drop rate and low handover success ratein the target cell.

4.4.2 Analysis of Missing Neighboring Cell ConfigurationThis describes the missing neighboring cell configuration, which is a common problem in theradio network. The analysis of the problem is a routine task on site.

4.4.3 Implementation of Optimization Against Missing Neighboring Cell ConfigurationThis describes the implementation of optimization against missing neighboring cellconfiguration. The process involves importing data, analyzing data, and implementingoptimization.



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4.4.1 Introduction to Missing Neighboring Cell ConfigurationThis describes the missing neighboring cell configuration. This problem frequently arises inconfiguring neighboring cells and may cause high call drop rate and low handover success ratein the target cell.

The following two problems often occur during the configuration of neighboring cells:

1. Missing neighboring cell configuration

It may directly cause a call drop.

2. Excessive neighboring cell configuration

It not only occupies too many neighboring cells but also affects the real-time measurement.

Therefore, proper neighboring cell configuration is very important.

4.4.2 Analysis of Missing Neighboring Cell ConfigurationThis describes the missing neighboring cell configuration, which is a common problem in theradio network. The analysis of the problem is a routine task on site.

The Nastar analyzes the problem of missing neighboring cell configuration in the followingsteps:

1. Imports the configuration data of specific neighboring cells.

2. Provides the list of the cells with missing neighboring cell configuration, the cells with fewneighboring cells, and unidirectional neighboring cells and then locates the missingconfiguration in the coverage area.

4.4.3 Implementation of Optimization Against MissingNeighboring Cell Configuration

This describes the implementation of optimization against missing neighboring cellconfiguration. The process involves importing data, analyzing data, and implementingoptimization.

Application Scenario

Missing neighboring cell configuration is a common problem in the radio network. The analysisof the problem is a routine task on site.

The optimization against the missing neighboring cell configuration is implemented in thefollowing scenarios:

l On-site operators find missing neighboring cell configuration in weekly analysis.

l When the service fails, operators find that a call drop occurs or the call fails to access dueto missing neighboring cell configuration.

Optimization Process

Figure 4-5 shows the process of optimization against missing neighboring cell configuration.




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Figure 4-5 Process of optimization against missing neighboring cell configuration

Start

Import data

Analyze missing neighboringcell configuration

Analyze cell KPIs based onmissing configuration data

Analyze missingconfiguration data

Implement the optimizationsolution

End

Analyzedata

The process involves the following steps:

l Import the performance data.

NOTE

For the method of importing data, refer to the Guide to the Nastar GSM v2.3 Tool.

l Analyze the parameters in the neighboring cell configuration. After locating missingneighboring cell configuration, analyze related data and judge the impacts to determinewhether to configure the missing neighboring cells.

l Implement optimization.In the case of missing configuration cells and poor KPIs, take the following measures:

1. Reconfigure the cells with missing configuration.2. Analyze routine KPIs. Check the variation of the KPIs and whether cell performance

meet the requirements.3. According to the KPI statistics, proceed as follows:

If the KPIs are improved, complete the optimization.If the KPIs fail to meet the requirements, you must take other optimization measures.For details, refer to the GSM Network Optimization Guideline.

4.5 Optimization Against Call Drop RateThis describes the optimization against call drop rate. The optimization aims to reduce the calldrop rate and improve the network quality.



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4.5.1 Introduction to Call Drop RateThis describes the problem of call drop rate. The call drop rate is an important KPI for assessingthe quality of the radio network. Thus, call drop may affect user satisfaction. The call dropincludes the call drops on the SDCCH and the call drops on the TCH.

4.5.2 Analysis of Call Drop RateThis describes the analysis of the call drop cause through signaling tracing. Then, optimizationagainst call drops is implemented according to specific causes.

4.5.3 Implementation of Optimization Against Call Drop RateThis describes the implementation of optimization against call drop rate by adjusting the BTStransmit power, antenna tilt angles, frequency planning, or handover parameters, and improvingthe engineering quality.

4.5.1 Introduction to Call Drop RateThis describes the problem of call drop rate. The call drop rate is an important KPI for assessingthe quality of the radio network. Thus, call drop may affect user satisfaction. The call dropincludes the call drops on the SDCCH and the call drops on the TCH.

The call drop rate is an important KPI for assessing the quality of the radio network. Thus, calldrop may affect user satisfaction.

This provides the causes and factors of call drops and restriction conditions and describes themeasures for locating and handling the call drops. You can take appropriate measures to reducethe call drop rate and improve network quality.

This also introduces the measures of dealing with worst cells caused by high call-dropping failurerate, reducing worst-cell ratio, thus decreasing call-dropping failure rate.

In terms of channels, call drops can be classified into the following types:

l Call drops on the SDCCHThe call drop on the SDCCH occurs when an MS occupies the SDCCH that is allocated tothe mobile station by the BSC but the TCH is not successfully allocated.

l Call drops on the TCHThe call drop on the TCH occurs when an MS occupies the TCH that is successfullyallocated to the mobile station by the BSC.

Generally, call drops can be categorized into the following types:

l RF call drop

l Handover call drop

l Call drop due to channel preemption of the services with different priorities

l Call drop due to the failure of equipment, such as TRXs and links

l Call drop due to insufficient coverage

In terms of protocols, call drops can be categorized into the following types:

l Radio interface message failure

l OM intervention

l Equipment failure




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l Protocol error between BSS and MSC

l Preemption

4.5.2 Analysis of Call Drop RateThis describes the analysis of the call drop cause through signaling tracing. Then, optimizationagainst call drops is implemented according to specific causes.

Symptoms of the Call Drop

Generally, the symptoms of high call drop rate in the current network are as follows:

1. The call drop rate per BSC increases. The handover call drop rate increases, the handoversuccess rate decreases, and frequent handovers are caused by the inferior quality of theuplink and downlink.l The rate of handovers caused by the uplink and downlink on the SDCCH and TCH

increases.l The levels of the uplink and downlink on the SDCCH and TCH are low, and many cells

are in the areas with high interference levels in the Interference Band Measurement.l The Mean Timing Advance increases; that is, call drops mainly occur at the edge of the

cell.2. The calls of MSs are often disrupted.3. Traffic call drop ratio is low.4. The alarms, such as VSWR alarms, LAPD disconnection alarms, A interface PCM loss of

sync. alarms, TRX failure alarms, and transmission intermittence alarms, are generated.

When the call drop rate increases, the corresponding call drop counters in the performancestatistics also increase. High call drop rate may cause exceptions of the following counters ofthe current network:

1. The call drop rate of target cells remains higher than 1%.2. The cell handover success rate remains lower than 90%.3. The traffic call drop ratio is lower than 100.

Possible Causes of Call Drops

The possible causes are as follows:

1. Coverage causesl Unsatisfactory coverage

l Insufficient coverage and cross coverage due to weak penetration capability and hightransmission attenuation of signals

l Inconsistent coverage on the main BCCH and SDCCH due to hardware failures

2. Handover causesl Incorrect handover parameters, missing neighboring cell configuration, or cells with the

same BCCH frequency and BSICl Congestion of the target serving cell due to high traffic volumes

l BTS clock out of synchronization or T3103 timeout



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3. Interference causesThe interference can be categorized into: co-channel interference, adjacent-frequencyinterference, inter-modulation interference, and inter-network interference.The interference may aggravate the BER so that the MS cannot demodulate the BSIC ofthe neighbor cell and the BTS cannot receive the measurement report from the MS.When the interference counter exceeds the threshold, calls in the network are interfered;the voice quality is thus affected and a call drop may occur.

4. Antenna and feeder causesl Reversely installed antennas or feeders

l Inconsistent coverage on the main BCCH and SDCCH due to improper installation ofantennas or feeders

l Faults of feeders

5. Transmission causesPoor quality of transmission links on the Abis interface and the A interface or unstablestatus of transmission links

6. Incorrect settings of radio parameters7. Other causes

4.5.3 Implementation of Optimization Against Call Drop RateThis describes the implementation of optimization against call drop rate by adjusting the BTStransmit power, antenna tilt angles, frequency planning, or handover parameters, and improvingthe engineering quality.

Different measures are taken in the optimization against high call drop rate due to differentcauses.

1. If a call drop occurs due to coverage problems, take the following measures:l Perform drive tests to locate the areas with insufficient coverage. Add BTSs to the areas

with discontinuous coverage, and expand the coverage of the BTS in the areas withunsatisfactory coverage.

l Increase the BTS transmit power in the areas with weak indoor coverage.

l Adjust tilt angles or modify the missing neighboring cell configuration in the areas withcross coverage.

2. If a call drop occurs due to handover problems, take the following measures:l Check the handover parameters, such as settings of stratum levels, handover thresholds,

handover hysteresis, handover measurement time, handover duration, and minimumaccess level of the candidate cell for handover.

l Improve handover thresholds to reduce handovers. Decrease handover thresholds toincrease handovers. Ensure that associated counters are normal when adjustinghandover thresholds.

l Calibrate the BTS clock.

l Balance traffic volumes of cells to handle the call drop due to unbalance of trafficvolumes.

3. If a call drop occurs due to interference, take the following measures:l Perform actual road tests. Check the places where interference occurs and distribution

of signal quality and analyze the coverage overlap of which cells causes the interference.




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l According to the actual condition, adjust the related BTS transmit power, tilt angle ofantenna, or frequency planning, to prevent interference.

l Use the discontinuous transmission (DTX) technology to remove the interferencecaused by the equipment itself, such as TRX self-activation and antenna inter-modulation interference.

4. If a call drop occurs due to transmission problems, take the following measures:l Check the alarms to analyze whether transmission is intermittent or whether boards are

faulty. If the hardware fails, replace the hardware.l Check whether the E1 connector or grounding of equipment is abnormal through the

BER test. If so, remove and then insert the connector.5. If a call drop occurs because of incorrect settings of the radio parameters, refer to the

following:BSC Configuration Parameter Reference.

6. If a call drop occurs due to the radio link failure, take the following measures:l If alarms are generated for multiple faulty links, locate and then rectify the faults on the

links.l If multiple call drops due to radio interface message failure still occur when the link

failure is cleared, optimize the radio network.The optimization against call drop rate aims to improve the quality of the radio network,to balance the uplink and downlink, reduce cross coverage and intra-networkinterference, and eliminate inter-network interference.You can adjust the azimuth, tilt angle, and height of the antenna, check engineeringquality, properly install antennas and feeders, adjust the transmit power, and use theDTX according to actual conditions.

7. Call drops due to OM Intervention disappear automatically after the correspondingoperations.

8. If a call drop occurs due equipment faults, take the following measures:l Check the alarms and the LMT control panel to clear the alarms.

l Reset or replace faulty boards or reload the software.

4.6 Optimization Against InterferenceThis describes optimization against interference. The optimization aims to reduce interference,intensify the reuse of frequencies, and thus improve the system capacity.

4.6.1 Introduction to InterferenceThis describes the interface that affects the network performance. The intra-network interferencecaused by frequency reuse and the inter-network interference from other communicationnetworks may affect the GSM network performance.

4.6.2 Analysis of InterferenceThis analyzes the causes for interference, and locates the interference problems through KPIs,LMT alarms, check on frequency planning and cell performance parameters, and drive tests.

4.6.3 Implementation of the Optimization Against InterferenceThis describes the location of interference and the measures taken in the optimization againstintra-network interference and inter-network interference.



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4.6.1 Introduction to InterferenceThis describes the interface that affects the network performance. The intra-network interferencecaused by frequency reuse and the inter-network interference from other communicationnetworks may affect the GSM network performance.

Frequency reuse refers to reusing the same frequency channel in different cells within the system.In the GSM system, frequency reuse is required to improve the system capacity.

The closest distance between the centers of two cells using the same frequency channel is calledthe reuse distance. The ratio of the reuse distance to the cell radius is called co-channelinterference factor. For a system with a specified amount of frequency channels, the tighter thefrequency reuse is, the greater the system capacity is, and the shorter the reuse distance is, thegreater the interference is.

The preceding interference caused by frequency reuse is intra-network interference. The GSMnetwork may be affected by inter-network interference from other communication networks.

Interference is the key factor that influences network performance. It greatly affects the voicequality, and causes call drop, handover, and congestion. Therefore, it is crucial to reduce oreliminate interference for improving the network performance.

4.6.2 Analysis of InterferenceThis analyzes the causes for interference, and locates the interference problems through KPIs,LMT alarms, check on frequency planning and cell performance parameters, and drive tests.

Symptoms of Interference1. When interference exists, the following symptoms may occur:

l The subscribers cannot hear each other and the background noise is loud.

l When a mobile subscriber is called, the mobile phone beeps and then the call isdisconnected.

l An established call connection stutters or even the call is dropped.

2. When network interference exists, the following symptoms regarding statistics may appear:l Interference band 4 or above arises, and the statistical value is greater than 1.

l The congestion rate is high because the interfered SDCCH causes immediate assignmentfailures or TCH assignment failures.

l The call drop rate is higher than 5%, which is far higher than those in other areas.

l The success rate of handovers is low.

3. When network interference exists, the following symptoms regarding drive tests mayappear:l The success rate of handovers is low.

l The level is high the QoS is poor.

4. The MA10/K1205 signaling analyzer traces the signaling messages over the Abis interfaceand finds that the Bit Error Ratio (BER) is higher than those in other areas.

Possible Causes for InterferenceInterference may be caused by many reasons. Based on interference sources, interference canbe classified into the following types:




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1. Intra-network interference

l Co-channel interference or adjacent channel interference

Co-channel interference arises or even becomes strong when the co-channelinterference factor is low.

l Interference caused by cross coverage

Cross coverage arises when the serving range of a cell is far larger than the actual servingrange. In the event of cross coverage, the signals are strong even though the MS isoutside the actual serving area. Cross coverage indicates that the actual cell coverage isgreatly deviated from the theoretical cell coverage. Cross coverage may cause abnormaltraffic absorption, interference, call drops, congestion, or handover failures.

l Interference caused by tight frequency reuse

In urban areas, the tight frequency reuse is required to improve frequency utilizationand to serve more subscribers. Therefore, the QoS is sacrificed to increase capacity. Ifthe BTSs are not distributed evenly, the tight frequency reuse may lead to collisionbetween cells using the same frequency channels.

l Interference generated by repeaters

Repeaters account for a major source of interference.

2. Inter-network interference

Inter-network interference generally comes from television stations, high-power stations,microwaves, radars, high-voltage power cables, simulated base stations, CDMA networks,or other GSM networks.

Interference Location1. Based on the KPIs, locate the cells that are interfered.

l For example, if the call drop rate, traffic volume, and congestion rate rise, and handoversuccess rate drops, you can infer that the associated cell is affected by interference.

l Then, check the operation records of the cell. For example, you can check whether theBTS hardware is replaced or added, or whether data is modified, because suchoperations cause interference.

l If data is not modified, the inference comes from the hardware or other communicationnetworks. In this case, check for hardware faults. If the problem persists even after yourectify the hardware faults, check for inter-network interference.

2. Check the alarms reported by the LMT.

Poor network performance, such as high call drop rate or congestion rate and low handoversuccess rate, may be caused by hardware faults. By checking the alarms reported by theLMT, you can quickly locate the faults and find the source of interference. The generationtime of alarms is generally associated with poor system performance.

Note that most of the alarms reported on the LMT are triggered by hardware faults, forexample, TRX failure and no output. For potential faults, such as self-excitation or a declinein the performance of the TRX/CDU, the system does not report alarms.

3. Check the frequency planning.

For a cell with poor performance, check the frequency planning of it and that of theneighboring cells. For example, check the location of the BTS, Azimuth angles andgeographic topology of the cells, frequencies and BSIC of the BCCH/TCH. Additionally,compare the actual frequencies with the planned frequencies to check for differences.



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Based on the frequency planning topology, use the Nastar to check whether co-channelinterference or adjacent-channel interference exists.

4. Check cell parameters.If the cell parameters, such as handover thresholds and handover measurement time/handover duration (based on P/N) are not correctly configured, interference may exist.l If there are missing neighboring cells, the MS cannot be handed over to a cell with better

signals and interference arises.l In addition, high handover thresholds or high P/N hinders smooth handovers and causes

slight interference.5. Perform drive tests.

Drive tests can facilitate fault location and interference elimination. Generally, two typesof drive tests are available: idle mode tests and dedicated mode tests.l Drive tests in idle mode

You can use test devices to test the signal level of the serving cell and those of theneighboring cells. You can also use a frequency scanner to test the specified frequenciesor frequency bands. The round-trip tests, however, must be conducted around the BTS.

l Drive tests in dedicated modeYou can use test devices to test the signal level, receive quality, power control level,and timing advance of the serving cell and those of the neighboring cells. If continuoushigh level (higher than 30) and poor receive quality (lower than 6) are detected in anarea, you can infer that interference exists in the area. Some test devices can display theFrame Error Rate (FER). If the displayed FER is higher than 25%, you can infer thatinterference exists in the area where the call connection stutters.

4.6.3 Implementation of the Optimization Against InterferenceThis describes the location of interference and the measures taken in the optimization againstintra-network interference and inter-network interference.

You can take the following measures to minimize or eliminate interference:

l In the event of inter-system interference, Huawei recommends that you adjust thefrequencies.

l In the event of intra-system interference, you can use frequency hopping, dynamic powercontrol, or DTX. In the tight reuse pattern, frequency hopping and dynamic power controlmust be used.

Adjustment of the azimuth angle, height, and tilt angle of the antenna is also frequently used tominimize interference. By adjusting the antenna, you can adjust the size of the actual servingarea based on the designed serving area and thus minimize cross coverage.

NOTE

Adjustment of the azimuth angle, height, and downtilt angle of the antenna is also frequently used tominimize interference. By adjusting the antenna, you can adjust the size of the actual serving area basedon the designed serving area and thus minimize cross coverage.

Note that when strong interference exists, the measures mentioned earlier may not be suited.




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4.7 Optimization Against Low Paging RateThis describes optimization against low paging rate. The optimization aims to improve thepaging success rate and user satisfaction.

4.7.1 Introduction to Low Paging Success RateThis describes the paging success rate. The paging success rate that indicates the pagingcapability of the system is the ratio of the paging responses received by the system to the primarypaging requests sent by the system.

4.7.2 Analysis of Low Paging Success RateThis analyzes the low paging success rate and describes the causes for the low paging successrate.

4.7.3 Implementation of the Optimization Against Low Paging Success RateThis describes the implementation of the optimization against low paging success rate byobserving the performance counters. When network optimization is complete, the running statusof the entire network is normal, and hardware and software are functional, increase the pagingsuccess rate according to the quality of the network, traffic models, and appropriate optimizationmeasures and parameters.

4.7.1 Introduction to Low Paging Success RateThis describes the paging success rate. The paging success rate that indicates the pagingcapability of the system is the ratio of the paging responses received by the system to the primarypaging requests sent by the system.

l Paging responses can be categorized into primary paging responses and secondary pagingresponse. The number of paging requests determines the number of paging responses.

l Paging can be categorized into speech call paging and short message paging.

All the wireless services are performed on the basis of paging. A high paging success rate canimprove multiple service KPIs in the case of certain hardware capacity. Optimization againstlow paging success rate helps to improve user satisfaction.

4.7.2 Analysis of Low Paging Success RateThis analyzes the low paging success rate and describes the causes for the low paging successrate.

Symptoms of Low Paging Success Rate1. If the paging success rate in the network is low, the following symptoms occur:

l A call is often put through only after the secondary attempt.

l An MS serving in an area with strong signals cannot be connected.

l The calling party needs longer than 10 s to connect with the called party.

2. If the paging success rate in the network is low, the variation trends of KPIs are as follows:l A decrease of Immediate Assignment Success Rate

l An alarm of paging overloads



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l Serious channel congestion

3. If the paging success rate in the network is low, the symptoms on the site are described asfollows:

l The number of paging requests on the A interface in every hour exceeds 800k.

l The paging success rate remains lower than 88%.

Possible Causes for Low Paging Success Rate

The possible causes are as follows:

l Unbalanced uplink and downlink

l Troubleshooting Interference

l Congestion of SDCCH

l Unsatisfactory coverage

l Paging overload

l BTS out-of-service

The preceding causes may be caused by the following problems:

l Unbalanced uplink and downlink comes from poor uplink signals of edge cells because thecoverage scope of the cell is set too large.

l Interference comes from co-channel and adjacent-channel interference owning to improperfrequency planning and reuse, radar interference, and repeater interference.

l MSs frequently initiate location updates owning to power off.

l Traffic volume exceeds the designed capacity.

l Data is configured incorrectly.

l The minimum access level on RACH and the grades of the signals received by MSs are setincorrectly.

l The common channel rate is set improperly.

To locate specific causes and solve problems, you can analyze KPIs manually or use the Nastarto analyze the KPIs of each cell.

1. Interference detecting

l Use interference detecting and location tools and appropriate methods to search forinterference sources and eliminate interference.

l Collect required co-channel neighboring data through the network. Traverse all carrierfrequencies or cells to search for co-channel cells and the frequencies or cells withinsufficient frequency reuse distances.

2. Traffic Statistics Analysis

l Analyze the associated KPIs of the cells with high call loss rates by using the trafficstatistics analysis function of the Nastar.

l Observe the running status of cells. Analyze the KPIs that may affect the paging successrate and each low KPI. According to specific causes, improve the paging success rate.




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4.7.3 Implementation of the Optimization Against Low PagingSuccess Rate

This describes the implementation of the optimization against low paging success rate byobserving the performance counters. When network optimization is complete, the running statusof the entire network is normal, and hardware and software are functional, increase the pagingsuccess rate according to the quality of the network, traffic models, and appropriate optimizationmeasures and parameters.

Observing performance counters is an important measure for increasing the paging success rate.

1. Observe paging overload KPIs and SDCCH congestion KPIs.2. If the low success rate is not caused by paging overloads and SDCCH congestion, you need

to observe the Immediate Assignment Success Rate, Interference Band Measurement, andUplink-and-Downlink Balance Measurement.l If a cell with large coverage has a low paging success rate, you need to improve the

Immediate Assignment Success Rate.l If the low paging success rate is caused by abrupt services in some cells, you need to

observe these cells. If exceptional symptoms do not occur during observation, thesecells are normal.

l If the Interference Band Measurement indicates that many cells are in the areas withLevel-5, Level-6, or Level-7 interference, the low success rate may be caused by stronginterference. You need to search for interference sources and reduce or eliminateinterference.

Ensure that network optimization is complete, the running status of the entire network is normal,and hardware and software are functional. Then, according to the quality of the network, trafficmodels, take appropriate optimization measures to improve the paging success rate.

1. For an area with low traffic volume, perform paging more than twice. For an area with hightraffic volume and excessive paging requests, perform paging twice.

2. Properly reduce the minimum access level on RACH and the minimum grade of the signalreceived by MSs.

3. Adjust the paging wait interval according to the actual requirements of the network.4. Choose combined BCCHs or non-combined BCCHs according to the paging requests and

the number of channels in a cell.5. The ratio of PCH, AGCH, and RACH is adjusted according to the random access reserved

blocks. Perform specific adjustments on the basis of actual network models and trafficdistribution.

NOTE

In general, the adjustment range in the suburb is smaller than that in the urban area.

4.8 Optimization Against Low MOSThis describes the optimization against low MOS. The optimization aims to increase the MOSvalue.

4.8.1 Introduction to Low MOSThis describes the Mean Opinion Scores (MOS) that helps to evaluate the quality of speechservices. MOS is developed based on the specifications defined in the ITU-T P.800 and P.830



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standards. Based on the perception of an original corpus and the processed corpus, a group oflisteners give their own scores on the corpus. thus, an average MOS score can be obtained.

4.8.2 Analysis of Low MOSThis analyzes the low MOS according to symptoms and locates the problems.

4.8.3 Implementation of the Optimization Against Low MOSThis describes the optimization against low MOS implemented by increasing the MOS. Youneed to improve network KPIs and improve the speech quality of the entire network by clearingproblems one by one.

4.8.1 Introduction to Low MOSThis describes the Mean Opinion Scores (MOS) that helps to evaluate the quality of speechservices. MOS is developed based on the specifications defined in the ITU-T P.800 and P.830standards. Based on the perception of an original corpus and the processed corpus, a group oflisteners give their own scores on the corpus. thus, an average MOS score can be obtained.

Table 4-2 lists the five levels of MOS.

Table 4-2 Five levels of MOS

Quality Level Score Requirements for Listener

Excellent 5 Attention not required

Good 4 Little attention

Fair 3 Moderate attention

Poor 2 Much attention

Unsatisfactory 1 Exceptional attention

NOTE

The description of different MOSs is as follows:

l 4.0–4.5: It is high-quality speech coding that meets the requirements of the toll telephone network.

l Around 3.5: The speech quality of the communication has decreased, but it does not affect normalconversations. Thus, it can meet the requirements of a great number of communication systems.

l Below 3.0: It is synthesized speech. Listeners can understand the meaning of speech but may fail todistinguish speakers.

MOS indicates the quality of the network on the basis of speech. Thus, performing theoptimization against low MOS can help to improve the quality of the network.

4.8.2 Analysis of Low MOSThis analyzes the low MOS according to symptoms and locates the problems.

Symptoms of Low MOS

If MOS is low, the following symptoms may occur during a call:




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l Speech discontinuity

l Noises

l One-way audio

l Call drops

When MOS is low, the symptoms shown on the test equipment are described as follows:

l The MOS is lower than 3.0.

l The low receiving quality alarm is generated.

Possible Causes for Low MOS1. Handovers

l Handover failureHandover failures lead to poor quality of serving cells.

l Frequent HandoversPing-pong handovers frequently occur.

l Improper handoverImproper handovers lead to poor quality of serving cells.

l Incorrect data configuration of handoversThe data of handovers, such as synchronous handovers and asynchronous handovers,is configured incorrectly.

2. Interference causesl Intra-network interference

Intra-network interference, such as interference due to cross coverage, interference dueto tight frequency reuse, and co-channel and adjacent-channel interference, leads to poorquality of speech.

l Inter-network interferenceInter-network interference, such as interference from radars and interference fromtransmission towers, leads to poor quality of speech.

3. Hardware failuresl Equipment failures

The problems, such as one-way audio and noises due to the failures of the BTS, BSC,TC, and transmission equipment, lead to poor quality of speech.

l Antenna systemPoor performance KPIs of the antenna system lead to poor quality of speech.

l Engineering qualityThe connectors of antennas and feeders are not in good condition or antennas and feedersare installed in a reverse manner.

4. Coverage causesl Insufficient coverage

Improper network planning or equipment failures lead to poor coverage ordiscontinuous coverage.

l Excessive coverage



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Excessive coverage leads to interference.5. Data configuration

l Uplink and downlink DTXs are enabled.

l Uplink and downlink power control are enabled.

l Hopping frequency is enabled.

l Frequency hopping mode is baseband hopping and RF hopping.

l Concentric cells are used.

6. Softwarel Compatibility of BTS Versions

In the event that the versions of existing BTSs fail to match those of new BTSs, thequality of speech is poor.

l Compatibility with non-Huawei equipmentThe MOS is low if the software is incompatible with the software of non-Huaweiequipment.

Problem LocationThe location tools for performing optimization against low MOS are as follows:

l Cormarco

l DSLA

Collect the drive test data of the target network. Analyze MOS by using speech analysis tools.Locate the causes of low MOS. Then, improve the speech quality of the areas with low MOS.

For the MOS results, pay attention to the following points:

l Test scores of uplink speech and downlink speech and the difference between the two scores

l Distribution of the test quality codes, as shown in Figure 4-6.

Figure 4-6 Distribution of test quality codes

l Analyze the causes of low MOS, such as signal levels on the air interface, interference, andbit errors. Then, perform optimization of speech quality.

l Check whether different codes in the network are qualified. Table 4-3 lists different codesand corresponding MOS.




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Table 4-3 Different codes and corresponding MOS

Codec Type Typical MOS Value Typical SQuadLQ

G0.711 4.3 4.4

G0.729 3.8 3.7

G.723.1 3.5 3.5

GSM-EFR 4 3.9

GSM-HR 3.4 3.3

AMR12.3 4 3.9

AMR7.4 3.8 3.7

AMR4.75 3.4 3.4

4.8.3 Implementation of the Optimization Against Low MOSThis describes the optimization against low MOS implemented by increasing the MOS. Youneed to improve network KPIs and improve the speech quality of the entire network by clearingproblems one by one.

Increasing MOS is the major optimization measure.

MOS is influenced by various factors and it can indicate the general performance of the network.Thus, to improve MOS, you need to improve network KPIs.

In addition, MOS can indicate speech quality. Thus, you need to improve the speech quality ofthe entire network by clearing problems one by one.

NOTE

The main measure to improve MOS is by checking whether data configuration is correct and universal.

The test results vary with the test tools and protocols, including P.300, P.800, P.861, P.862, and P563.Therefore, use appropriate tools according to the features of different tools.

Process of the Optimization Against Low MOSFigure 4-7 shows the process of the optimization against low MOS.



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Figure 4-7 Process of the optimization against low MOS

Start

Collect network speechevaluation data

Perform data analysis anddecision

Procedureanalysis

MOSevaluation

Problemhandling

Resultanalysis

Competitionanalysis

Prepare the optimizationsolution


End

Optimization Solutions Against Low MOSAfter preparing the optimization solution against low MOS, proceed as follows:

l Handle the speech problems of partial sites on the basis of the specific causes.

l Check whether the code mode of a single site is proper in the case of low MOS owning tocode modes. Then, perform optimization against low MOS of the entire network.

l Change the handover mode and handover frequency in the case of low MOS owning tohandovers.

l Perform optimization against incorrect network parameters, such as DTX and powercontrol.

Verify the results after the optimization. Evaluate the quality of the entire network and checkwhether the results reach the optimization purposes. Ensure that the routes and tools ofoptimization and evaluation are the same as those required in the test solutions and that MOS isimproved greatly after optimization.




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4.9 Optimization Against Low Handover RateThis describes the optimization against low handover rate. The optimization aims to increasethe handover rate and improve the network quality.

4.9.1 Introduction to Low Handover Success RateThis describes the handover success rate, which indicates the handover capability of the system.The handover success rate is the ratio of all successful handovers to all handover requeststriggered by all causes.

4.9.2 Analysis of Low Handover Success RateThis analyzes the low handover success rate and locates the problems by checking the alarmsand neighboring cell configuration, observing performance counters, performing drive tests onthe faulty cells, and analyzing the signaling tracing results.

4.9.3 Implementation of the Optimization Against Low Handover Success RateThis describes the optimization of the handover success rate implemented by analyzing data,optimizing the schemes, and verifying the schemes.

4.9.1 Introduction to Low Handover Success RateThis describes the handover success rate, which indicates the handover capability of the system.The handover success rate is the ratio of all successful handovers to all handover requeststriggered by all causes.

The handover can be categorized into different types.

l According to whether the MSC is involved in the handover, handovers are categorized intointra-BSC handovers and inter-BSC handovers.

l Intra-BSC handovers are categorized into intra-BSC intra-cell handovers and inter-cellhandovers.

The handover success rate, an important counter indicating the network quality, has an impacton other related service counters. Therefore, the optimization of the handover success rate cangreatly improve network performance.

4.9.2 Analysis of Low Handover Success RateThis analyzes the low handover success rate and locates the problems by checking the alarmsand neighboring cell configuration, observing performance counters, performing drive tests onthe faulty cells, and analyzing the signaling tracing results.

Symptoms of Low Handover Success RateWhen the network has a low handover success rate, call drops may easily occur.

1. When the network has a low handover success rate, the following KPI changes may occur:l The call drop rate increases.

l The TCH seizure success rate decreases.

l The handover requests increase.

l The channel congestion occurs frequently.



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2. When the handover success rate in the network is low, the following symptoms may occur:l The TCH seizure success rate is always lower than 90%.

l The handover success rate is always lower than 90%.

Possible Causes for Low Handover Success RateThe low handover success rate may be due to the following causes:

l Hardware failuresHandover failures may occur in the target cells because of hardware failures. The hardwarefaults include TRX faults of the BTS, loose connection or damage of antenna connectors,unlocking of the clock.

l Interference causesIn the process of signaling exchange on the air interface, interference may cause signalingexceptions and a low handover success rate. The interference sources may be intra-networkinterference, for example the interference of third order intermodulation, or inter-networkinterference, for example the repeater interference.

l Coverage causesHandovers occur because of insufficient coverage, but the handovers fail because the MSis located in a blind area.

l Configuration causesIncorrect configuration causes handover failures. For example the incorrect or unreasonableparameter setting of the underlaid subcell and overlaid subcell for a concentric cell causesoverload of the overlaid subcell, so handovers from the underlaid subcell to overlaid subcellfail.

l Clock causesThe clock of target cells is out of synchronization, so handovers fail.

Possible Causes for Low Handover Success RateTo locate the problem of low handover success rate, do as follows:

1. Check whether the cells with low handover success rate have hardware alarms.2. Check whether there is any missing neighboring cell.3. Observe the performance statistics. Use the Nastar to make analysis, locate the faulty cells,

and locate problems. During the analysis, pay attention to the following counters:l Handover performance measurement

l TCH performance measurement

l Interference band measurement

Analyze the preceding performance counters and observe the following aspects:l TCH seizure, such as call drop rate

l Success Rate of Cell Incoming Handovers and Success Rate of Cell OutgoingHandovers

l Distribution of causes of handover failures

l Radio Handover Success Rate

4. Conduct drive tests for the faulty cells and analyze the signaling tracing results. Payattention to the following aspects of the signaling tracing results:




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l Check whether the uplink and downlink levels of the faulty cells are balanced.Unbalanced downlink and uplink levels may cause handover failures. If the uplink anddownlink levels often become unbalanced, you can infer that the BTS hardware havefaults and cross coverage exists.

l Check whether the measurement reports of the faulty cells include correct lists ofneighboring cells.

l Check whether handovers from the faulty cells to neighboring cells and handovers fromthe neighboring cells to the faulty cells is successful. Analyze to check whether thesignaling process of handovers is normal.

4.9.3 Implementation of the Optimization Against Low HandoverSuccess Rate

This describes the optimization of the handover success rate implemented by analyzing data,optimizing the schemes, and verifying the schemes.

For optimization of the handover success rate, analysis about handovers must be made based onlarge-scale data collection in the existing network. For optimization of the handover successrate, pay attention to handover exceptions, which occur in a low probability. The fluctuation ofKPIs adversely affects data analysis; therefore, the existing network must have stable KPIs andno network is newly deployed or swapped.

The optimization schemes based on data analysis must be tested on the existing network. Do notperform the optimization schemes until the schemes prove to be feasible by tests.

Figure 4-8 shows the process of the optimization against low handover success rate.



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Figure 4-8 Process of the optimization against low handover success rate

Start

Filter the cells with the poorHandover Success Rate

Perform signaling analysisand decision of handover data

TCH congestionof target cell

Balance ofuplink and

downlink; clocksynchronization

duringhandovers

Handoveralgorithm and

threshold

Radio network,quality of the air

interface

Dataconfiguration

Prepare the optimizationsolution


End

A case of the on-site analysis on cell incoming handover failures is given below.

You can take the following steps to find out the causes for failed incoming inter-cell handoversusing the signaling analysis tool.

1. Use the signal analysis tool to filter the ch_act messages that are sent during handovers andthe ho_complete messages. The signal analyze tool can filter the ch_act messages of onlythe synchronous and asynchronous handovers.

2. Channels can be activated for both synchronous and asynchronous handovers. Therefore,the following cases may occur after the message filtering is complete:

l The ch_act message of a cell incoming handover is in one-to-one mapping with aho_complete message, indicating that the handover is successful.

l The ch_act message of a cell incoming handover corresponds with multipleho_complete messages, indicating that the handover is successful and the surplusho_complete messages are sent for the other type of handovers. For example, if thech_act message is sent for an asynchronous handover, the other ho_complete messagesare sent for the ch_act messages of synchronous handovers.




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l The ch_act message of a cell incoming handover has no corresponding ho_completemessage, indicating that the handover fails. In this case, conduct call tracing orassociated call tracing of the ch_act message to query the signaling of the Abis interfaceand A interface and make further analysis.

Figure 4-9 shows the Abis-interface signaling of a failed cell incoming handover in thecall tracing result.

Figure 4-9 Signaling of a failed cell incoming handover

3. Based on the analysis of the preceding signaling, it is found that the MS continuously reportsmultiple SABMs but receives no UA, so the T200*N200 timer of the MS times out and theMS reports a handover failure message in the original channel. Therefore, the originatingcell sends an internal release request to the target cell, and the target channel is released.

4. Based on the analysis on the signaling of the failed cell incoming handover, codes, and dataconfiguration, for example the value of the timer, it is found that most handover failuresare caused by the poor quality of the air interface. Some handover failures are due toincorrect selection of target cells by the originating cells, namely that the originating cellsselect target cells with poor quality. The Nastar can be used to analyze and locate someobvious errors. For example, the co-channel and adjacent-channel interference, that causethe poor quality of the air interface. To locate other causes of poor quality of the air interface,RF optimization and parameter optimization must be performed later.

4.10 Optimization Against Poor Network CoverageThis describes the optimization against poor network coverage. The optimization aims to reducethe excessive coverage, insufficient coverage, or unbalanced coverage of the network andimprove the network quality.

4.10.1 Introduction to Poor Network CoverageThis describes poor network coverage, which involves excessive coverage, insufficientcoverage, and unbalanced coverage. Poor network coverage leads to the low access success rate,high call drop rate (due to connection failures, error indications, and so on), low handover successrate, and poor voice quality.

4.10.2 Analysis of Poor Network CoverageThis analyzes the problem of poor network coverage. You can locate the coverage problemsthrough the DT test data, CQT test data, and signaling statistics at the network side.

4.10.3 Optimization Implementation Against Poor Network Coverage



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This describes the optimization against poor network coverage implemented by optimizing theRF parameters and cell parameters through the coverage extension technology or BTSadjustment.

4.10.1 Introduction to Poor Network CoverageThis describes poor network coverage, which involves excessive coverage, insufficientcoverage, and unbalanced coverage. Poor network coverage leads to the low access success rate,high call drop rate (due to connection failures, error indications, and so on), low handover successrate, and poor voice quality.

4.10.2 Analysis of Poor Network CoverageThis analyzes the problem of poor network coverage. You can locate the coverage problemsthrough the DT test data, CQT test data, and signaling statistics at the network side.

Possible Causes for Poor Network CoverageRadio coverage problems are generally due to the following causes:

l Incomplete network planning and imperfect radio network structure

l Faulty equipment

l Poor engineering quality

l New requirements for coverage

The possible causes for the poor coverage in the radio network are as follows:

1. Poor construction quality of the antenna system2. Incorrect antenna type selection3. Exceptions of the TMA4. Unreasonable settings of the coverage-related parameters5. The radio coverage may be affected by the following faults of the BTS system:

l The output power of the transmitter decreases.

l The sensitivity of the receiver decreases.

l The azimuth of the antenna changes.

l The pitch angle of the antenna changes.

l The antenna gain changes.

l The loss of feeders, loss of couplers, or the work frequency changes.

l The propagation environment changes.

l The diversity reception affects coverage.

6. InterferenceInterference affects the receiving capability of the BTS, and thus decreases coverage. Youcan detect interference by checking the interference bands (uplink) in traffic statistics orconducting drive tests (indicated by the high level and low quality of the downlink). Theinterference is classified into the following types:l Interference generated by repeaters




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l Interference caused by the passive intermodulation (PIM) of the antenna and connectors.

l Radar interference

l Intra-network interference caused by the improper frequency planning

l Intra-network interference caused by the improper settings of the frequency hoppingparameters

Problem Location

To locate coverage problems, use data sources, such as DT test data, CQT test data, and signalingstatistics at the network side.

l According to the DT and CQT test data, make statistics on the downlink coverage.

l According to the signaling statistics at the network side, make analysis on the uplink anddownlink receiving levels and quality. The test data and signaling statistics at the networkside can help to detect and locate all uplink and downlink coverage problems.

After locating the top N cells with coverage problems, do as follows to locate the problems:

l Check whether the increase in background noise of the entire area is caused by interferenceor poor electromagnetic environment.

l Check whether there are VSWR alarms and main and diversity receive alarms on the SiteMaintenance System.

l Check whether the parameter settings related to coverage are appropriate.

l Check engineering parameters such as the tilt angles and azimuth of the antenna.

l Check the output power on the top of the transmitter.

l Check the receiver sensitivity of the BTS.

l Use the SITEMASTER to check whether the VSWR is lower than 1.

l Check for exceptions of the power amplifier.

l Check the propagation environment and the electromagnetic environment surrounding theBTS.

4.10.3 Optimization Implementation Against Poor NetworkCoverage

This describes the optimization against poor network coverage implemented by optimizing theRF parameters and cell parameters through the coverage extension technology or BTSadjustment.

Measures for the Optimization Against Poor Network Coverage

Coverage optimization can be implemented through optimization of RF parameters and cellparameters.

1. RF parameter optimizationRF parameter optimization involves checking the installation of the antenna, adding anantenna, adjusting the azimuth and tilt angles of the antenna, and replacing the antenna withanother model. Replacing the antenna with another model means using an antenna with adifferent antenna gain, horizontal lobe width, vertical lobe width, or electrical tilt function.



4-35

2. Cell parameter optimizationThe following is involved in cell parameter optimization:l Carrier Configuration Table

l Carrier Power Rank

l Antenna Configuration Table

l Whether there is any TMA and Attenuation Factor. For details, refer to Antenna FeederAttribute Parameters.

l System Information Data Table

l Radio Link Timeout (SACCH period(482ms)) and MS maximum transmit powercontrol rank

l RXLEV_ACCESS_MIN, Power Deviation Indication, and Power Deviation (2dB)

l Cell attribute parameters. For details, refer to Basic Attribute Parameters.

l SACCH Multi-Frames (SACCH period (480 ms)), RACH Busy Threshold,Random Access Error Threshold, and RACH Minimum Access Level

l Handover parameters and power control parameters

For an area with wide coverage, check the following:l Edge HO UL RX_LEV Threshold

l Edge HO Valid Time(s)

l RACH Min Access Level of the candidate cell (If the parameter is set incorrectly,handovers cannot be implemented promptly and call drops occur, thus causing pseudodiscontinuous coverage in some areas.)

l If the power control threshold of the candidate cell is set to a very small value, the calldrop rate will be increased. For details, refer to Basic Power Control Parameters.

Optimization Measures1. Coverage enhancement

l Extended cell– According to the GSM specifications, the maximum Timing Advance (TA) of cells

on the radio interface is 63 bits, so the coverage radius of a cell cannot be greaterthan 35 km. In the vast and sparsely populated areas where the traffic is low and thetransmission and power supply facilities are unavailable, however, cells with thecoverage radius of larger than 35 km are needed.

– The extended cell technology supports the coverage radius of larger than 35 km.With the support of the BTS hardware, the extended cell technology even supportsthe coverage radius of 120 km. With extended cells, telecommunication carriers canimplement rapid and cost-effective deployment of GSM networks in remote areas;thus improving the gain.

l Diversity technologyWith various diversity technologies, a high diversity gain can be obtained and thus theBTS reference sensitivity level can be promoted. The diversity reception technologyenables the receiver to receive two or more input signals that have uncorrelated randomfading characteristics and implement special processing to minimize the RaileighFading.

l Concentric cell




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The concentric cell technology divides an ordinary cell into two service layers: overlaidsubcell and underlaid subcell. The system allocates the frequency points that use thesparse frequency reuse, for example the BCCH frequency points, to the MSs in theunderlaid subcell, and allocates the frequency points that use the aggressive frequencyreuse, for example the frequency points outside the BCCH, to the MSs in the overlaidsubcell. The system capacity can be improved by using the aggressive frequency reusein the overlaid subcell.If multiple carriers are combined, the carriers have different insertion losses. In aconcentric cell, the carriers with a small insertion loss provide coverage to the underlaidsubcell, and the carriers with a big insertion loss provide coverage to the overlaidsubcell. The overlaid subcell serves for the areas near the BTS, for example thedowntown business district, and the underlaid subcell serves for the areas far away fromthe BTS, for example roads and countryside where the traffic is low.

2. BTS adjustmentCoverage problems can be solved by the following types of BTS adjustment:l Adding macro BTSs

l Adjusting the location of the BTSs

l Adjusting the location height of the BTSs

l Adjusting the model of the BTSs

l Adjusting the cell split mode



4-37

5 Real-Time Monitoring

About This Chapter

You can monitor the system on the M2000 Client and thus monitor the quality of the wirelessnetwork.

5.1 Functions of Real-Time MonitoringThe functions of realtime monitoring consists of routine monitoring, hotspot monitoring, andmaintenance monitoring.

5.2 KPIs Involved in Real-Time MonitoringThe KPIs involved in real-time monitoring consist of BSC-level KPIs and cell-level KPIs.

HUAWEI BSC6000 Base Station SubsystemBSS Performance Management Guidelines 5 Real-Time Monitoring


5-1

5.1 Functions of Real-Time MonitoringThe functions of realtime monitoring consists of routine monitoring, hotspot monitoring, andmaintenance monitoring.

l Route monitoringThe trend and threshold alarms of BSC-level KPIs are monitored.

l Hotspot monitoringThe trend and threshold alarms of cell-level KPIs are monitored.

l Maintenance monitoringThe specified KPIs are monitored when some parameters are cut over or when you arelocating faults.

Thus, operators require real-time monitoring with the granularity of five minutes, three minutes,or even one minute. The M2000 Client supports real-time monitoring with a minimumgranularity of one minute.

5.2 KPIs Involved in Real-Time MonitoringThe KPIs involved in real-time monitoring consist of BSC-level KPIs and cell-level KPIs.

BSC-Level KPIs Involved in Real-Time MonitoringThe BSC-level KPIs involved in real-time monitoring are as follows:l Handover Success Ratio per BSC

l Traffic Volume on TCH per BSC

l Success Rate of Call Establishment per BSC

l Congestion Rate on TCH per BSC (All Channels Busy)

l Call Drop Ratio on TCH per BSC (Including Handover)

Cell-Level KPIs Involved in Real-Time MonitoringThe cell-level KPIs involved in real-time monitoring are as follows:l Call Drop Ratio on TCH per cell (Including Handover)

l Traffic volume on TCH per Cell

l Success Rate of Call Establishment per Cell

l Success Rate of Handover per Cell

5 Real-Time MonitoringHUAWEI BSC6000 Base Station Subsystem



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6 Call History Records Reference

About This Chapter

This describes call history records (CHRs). The CHRs include four areas: common informationarea, track information area, measurement report area, and field information area.

6.1 Introduction to Call History RecordsThis describes Call History Record (CHR). CHRs record each call according to theircharacteristics for tracing the problems on the user plane. Generally, only call drops andabnormal calls are recorded due to limit in data volume and bandwidth.

6.2 Call History Records Data Area ReferenceThis describes the data area of call history records (CHRs). The data areas of CHRs includecommon information area, track information area, measurement report area, and fieldinformation area.

HUAWEI BSC6000 Base Station SubsystemBSS Performance Management Guidelines 6 Call History Records Reference


6-1

6.1 Introduction to Call History RecordsThis describes Call History Record (CHR). CHRs record each call according to theircharacteristics for tracing the problems on the user plane. Generally, only call drops andabnormal calls are recorded due to limit in data volume and bandwidth.

Collection of CHRsCHRs are implemented in the BSC6000V900R003. The BSC6000 host service module recordsthe trace of a call and the call control block (CCB) information.

Analysis tools can be used in specified analysis of the CHR log files, such as CallTrace.

Data ApplicationCHRs record the detailed process of establishing a cell and save the information throughhardware files.

Engineers can trace the problems in user complaints and call failure through these records forfault location.

Classification of the CHR Data AreaThe CHR interface is divided into the following areas, as shown in Figure 6-1:

l Common Information Area of CHRs

l Trace Area of CHRs

l Measurement Report Area of CHRs

l Field Information Area of CHRs

Figure 6-1 CHR interface

6 Call History Records ReferenceHUAWEI BSC6000 Base Station Subsystem



Issue 01 (2008-06-10)

6.2 Call History Records Data Area ReferenceThis describes the data area of call history records (CHRs). The data areas of CHRs includecommon information area, track information area, measurement report area, and fieldinformation area.

6.2.1 Common Information Area of CHRsThis describes the common information area of CHRs. In the common information area, thebasic common information of calls is recorded. If you want to query information by calls, therecords of a call are marked with the same color. In the common information area, three typesof information according to attributes are recorded: general information, identifier information,and basis resource information.

6.2.2 Trace Area of CHRsThis describes the data attributes and meanings of track information.

6.2.3 Measurement Report Area of CHRsThis describes the measurement report area of CHRs.

6.2.4 Field Information Area of CHRsThis describes the field information area of CHRs.

6.2.1 Common Information Area of CHRsThis describes the common information area of CHRs. In the common information area, thebasic common information of calls is recorded. If you want to query information by calls, therecords of a call are marked with the same color. In the common information area, three typesof information according to attributes are recorded: general information, identifier information,and basis resource information.

General InformationFigure 6-2 shows the general information interface of common information area.

Figure 6-2 General information interface of common information area



6-3

Table 6-1 describes the attributes and meanings of general information as shown in Figure6-2.

Table 6-1 Description of general information

Attribute Name

Meaning Remarks

CallID Number of the call —

Each call has a unique call ID. Therecords with the same call ID are therecords of the same call.

Date Output date of a record. The precisionof the date can be millisecond.

—

SubrackNo.

Number of the subrack where theboard that processes the call record islocated

—

Slot No. Number of the slot where the boardthat processes the call record is located

—

CPU No. Number of the CPU where the boardthat processes the call record is located

—

Tick The value of Tick when the record isgenerated

From the beginning of a successfulboard uploading, the value of Tickincreases by 1 every 10 milliseconds.

MainCCB

The CCB of the MSIP in the fieldinformation area. An MSIP instance isestablished for each call.

—

Start Tick The value of the start Tick of the call From the beginning of a successfulboard uploading, the value of Tickincreases by 1 every 10 milliseconds.

Save Tick Saving the output value of Tick From the beginning of a successfulboard uploading, the value of Tickincreases by 1 every 10 milliseconds.




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Attribute Name

Meaning Remarks

SavingType

General causes that records are saved.The cause values are as follows:l Call drop caused by failed radio

connectionl Call drop caused by equipment

faultsl Call drop caused by other faults

l Call setup failure caused by expiredlink establishment

l Call setup failure caused by otherfaults

l Handover failure

l Call logs saved by specifiedhandsets

l Abnormal processing of internalsoftware

l Reserved 1

l Reserved 2

l Reserved 3

l Reserved 4

l Reserved 5

l Reserved 6

l Reserved 7

l Reserved 8

Currently, most of records are savedwith the cause value of "Abnormalprocessing of internal software". Infuture, the saving causes of records willbe specific.



6-5

Attribute Name

Meaning Remarks

SavingCause

The specific cause values are asfollows:l Message decoding failure

l Channel request message receivedon the non-main BCCH

l Failed response to theestablishment of a CRDLCinstance

l Expired response to theestablishment of a CRDLCinstance

l Failed message sending

l Call setup failure caused by otherfaults

l Abnormal SAPI0

l Call logs saved by specifiedhandsets

l Abnormal processing of internalsoftware

l Reserved 1

l Reserved 2

l Reserved 3

l Reserved 4

l Reserved 5

l Reserved 6

l Reserved 7

l Reserved 8

Currently, most of records are savedwith the cause value of 65535. In future,the saving causes of records will bemore specific.

Call Identifier InformationFigure 6-3 shows the identifier information interface of the common information area.




Issue 01 (2008-06-10)

Figure 6-3 Identifier information interface of the common information area

User identifier information, including TMSI, IMSI, MSISDN, and IMEI, is recorded. Whetherto record TMSI, IMSI, or IMEI information depends on the policy of the core network. Therecords can be output only when the user identifier information is included in the reported callsignaling. Otherwise, the records are null.

Basic Resource InformationFigure 6-4 shows the basic resource information interface of the common information area.



6-7

Figure 6-4 Basic resource information interface of the common information area

The basic resource information records the basic resources occupied by calls. Table 6-2describes the attributes and meanings of basic resource information as shown in Figure 6-4.

NOTE

If no resource is occupied by calls when a record is output, the resource data is invalid. As shown in Figure6-2, the values 65535 and 255 are invalid.

Table 6-2 Description of basic resource information

AttributeName

Meaning Remarks

SiteId Index number of the site that a callis generated

-

CellId Index number of the cell that a callis generated

-

TrxId Index number of the TRX that a callis generated

-

ACic Number of the A-interface CICoccupied by a call

-




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AttributeName

Meaning Remarks

DspNo Number of the DSP occupied by acall

-

TcNo Number of the TC occupied by a call -

ChanNo Number of the channel occupied bya call

-

SpeechDataInd Type of speech data services. Threetypes of speech data services are asfollows:l Speech service

l Data service

l Signaling service

-

SpeechVer Speech version of a call. The speechversions are as follows:l 1 Full-rate speech version 1

l 17 Full-rate speech version 2

l 33 Full-rate speech version 3

l 5 Half-rate speech version 1



l 38 Invalid

For signaling services, the speechversion is 38.

6.2.2 Trace Area of CHRsThis describes the data attributes and meanings of track information.

Figure 6-5 shows the interface of the track information area.

Figure 6-5 Interface of the track information area

In the track information area, the trace information of a call is recorded. Table 6-3 describes theattributes and meanings of track information.



6-9

Table 6-3 Description of track information

AttributeName

Meaning Remarks

ID ID of a record. The IDs of records are arrangedin the order of time.

-

TrackID ID of track information. Each track has aunique ID. For the records of different calls, ifthe track information is the same, the value ofTrackID is the same.

-

Tick Tick value -

Level Level of a record. CHRs can be categorizedinto the following three levels:l Level 0: PROMPT, normal

l Level 2: ERROR

l Level 3: ASSERT

By default, the records oflevel 2 or above can beoutput.

File File name of the codes -

File Line Number of the line where a record is located inthe file

-

TrackInformation

Track information of a record -

6.2.3 Measurement Report Area of CHRsThis describes the measurement report area of CHRs.

Figure 6-6 shows the interface of the measurement report area.




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Figure 6-6 Interface of the measurement report area

In the measurement report area as shown in Figure 6-6, except for "ID" and "Tick", "Type"refers to the type of a measurement report. The value 0 indicates an ordinary measurement report,and 1 indicates a preprocessing measurement report.

In the column of "Measurement Information", you can click a measurement report to view thespecific content of the measurement report in the right pane as shown in Figure 6-6.

6.2.4 Field Information Area of CHRsThis describes the field information area of CHRs.

Figure 6-7 shows the interface of the field information area.



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Figure 6-7 Interface of the field information area

All field information of a call is saved in the field information area. Click a section to view thespecific content of the section. The information in sections, however, helps engineers to locateand analyze errors according to codes.




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