54461517 BSS Troubleshooting Guide V900R008C01 01

HUAWEI BSC6000 Base Station Subsystem

V900R008

BSS Troubleshooting Guide

Issue 01

Date 2008-06-10

INTERNAL

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Huawei Technologies Co., Ltd. provides customers with comprehensive technical support and service. For anyassistance, please contact our local office or company headquarters.

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Copyright © Huawei Technologies Co., Ltd. 2008. All rights reserved.No part of this document may be reproduced or transmitted in any form or by any means without prior writtenconsent of Huawei Technologies Co., Ltd. Trademarks and Permissions

and other Huawei trademarks are the property of Huawei Technologies Co., Ltd.All other trademarks and trade names mentioned in this document are the property of their respective holders. NoticeThe information in this document is subject to change without notice. Every effort has been made in thepreparation of this document to ensure accuracy of the contents, but the statements, information, andrecommendations in this document do not constitute a warranty of any kind, express or implied.

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mailto:[email protected]

Contents

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

1 Introduction to BSS Troubleshooting....................................................................................1-11.1 Troubleshooting Process.................................................................................................................................1-21.2 Common Troubleshooting Methods................................................................................................................1-41.3 Huawei Technical Support..............................................................................................................................1-6

1.3.1 Obtaining Technical Support.................................................................................................................1-71.3.2 Information Collected for Troubleshooting...........................................................................................1-71.3.3 Fault Location Record Form..................................................................................................................1-8

2 Collecting Information for Locating BSS Faults..................................................................2-12.1 Collecting the Local Information....................................................................................................................2-32.2 Collecting BSC Configuration Data................................................................................................................2-42.3 Collecting M2000 Performance Measurement Information...........................................................................2-52.4 Collecting BSC Performance Measurement Information...............................................................................2-72.5 Collecting BSS Alarm Information.................................................................................................................2-7

2.5.1 Collecting BSS Alarm Log Files............................................................................................................2-72.5.2 Collecting BSS Alarm Information......................................................................................................2-10

2.6 Collecting BSS Log Information...................................................................................................................2-102.6.1 Collecting BSC Log Files....................................................................................................................2-102.6.2 Collecting BTS Log Files.....................................................................................................................2-122.6.3 Collecting LMT Log Files....................................................................................................................2-14

2.7 Collecting GBAM/GOMU Information........................................................................................................2-142.7.1 Collecting Information About the GBAM Model................................................................................2-142.7.2 Collecting Running Information About the GBAM/GOMU Local Processes....................................2-142.7.3 Collecting Running Information About the GBAM/GOMU Core Processes......................................2-152.7.4 Collecting Other Information About the GBAM/GOMU....................................................................2-16

2.8 Collecting Messages Traced on the BSC......................................................................................................2-172.9 Collecting TRACE Files of the M2000.........................................................................................................2-172.10 Collecting Channel Status Information.......................................................................................................2-182.11 Collecting Board Bar Code Information.....................................................................................................2-192.12 Collecting Voice Tuning Information.........................................................................................................2-202.13 Collecting External PCU Information.........................................................................................................2-21

2.13.1 Collecting PCUINFO Information.....................................................................................................2-21

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2.13.2 Collecting Messages Traced on the External PCU............................................................................2-24

3 Common Faults...........................................................................................................................3-13.1 Troubleshooting One-Way Audio or No Audio..............................................................................................3-23.2 Troubleshooting Noises...................................................................................................................................3-33.3 Troubleshooting Cross Connection Faults......................................................................................................3-5

4 Link Faults...................................................................................................................................4-14.1 Link Fault Symptoms......................................................................................................................................4-2

4.1.1 Impacts of Link Faults on Services........................................................................................................4-24.1.2 Alarms Related to Link Faults...............................................................................................................4-34.1.3 Counters Related to Link Faults.............................................................................................................4-9

4.2 Link Troubleshooting Methods.....................................................................................................................4-114.2.1 Troubleshooting OML Faults...............................................................................................................4-134.2.2 Troubleshooting EML Faults...............................................................................................................4-144.2.3 Troubleshooting RSL Faults................................................................................................................4-164.2.4 Troubleshooting ESL Faults.................................................................................................................4-174.2.5 Troubleshooting PBSL Faults..............................................................................................................4-184.2.6 Troubleshooting SS7 Signaling Link Faults........................................................................................4-234.2.7 Troubleshooting Ater Signaling Link Faults........................................................................................4-264.2.8 Troubleshooting Ater OML Faults.......................................................................................................4-274.2.9 Troubleshooting E1/T1 Transmission Faults.......................................................................................4-274.2.10 Troubleshooting Optical Transmission Faults...................................................................................4-284.2.11 Troubleshooting M3UA Link Faults..................................................................................................4-294.2.12 Troubleshooting M3UA Route Unavailability Faults........................................................................4-324.2.13 Troubleshooting M3UA Destination Entity Inaccessibility Faults....................................................4-334.2.14 Troubleshooting Abis Interface IP Link Faults..................................................................................4-36

4.3 Typical Cases of Troubleshooting Link Faults.............................................................................................4-374.3.1 Case: BTS TRX Faults.........................................................................................................................4-384.3.2 Case: BTS Faults..................................................................................................................................4-384.3.3 Case: BTS Loading Failure..................................................................................................................4-394.3.4 Case: Abis Transmission Faults...........................................................................................................4-394.3.5 Case: M3UA Link Faults.....................................................................................................................4-40

5 Clock Faults.................................................................................................................................5-15.1 Clock Fault Symptoms....................................................................................................................................5-2

5.1.1 Impacts of Clock Faults on Services......................................................................................................5-25.1.2 Alarms Related to Clock Faults.............................................................................................................5-25.1.3 Counters Related to Clock Faults...........................................................................................................5-5

5.2 Clock Troubleshooting Methods.....................................................................................................................5-55.2.1 Troubleshooting Clock Source Faults....................................................................................................5-55.2.2 Troubleshooting Board Clock Faults.....................................................................................................5-7

5.3 Typical Cases of Troubleshooting Clock Faults.............................................................................................5-75.3.1 Case: All BTS Clock Reference Sources Unavailable...........................................................................5-8

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5.3.2 Case: Slip Frame Alarm.........................................................................................................................5-85.3.3 Case: Phase-Locked Loop in Non-Locked State....................................................................................5-95.3.4 Case: Handover Call Drop Due to Large Frequency Offset of BTS Clock.........................................5-11

6 Handover Faults.........................................................................................................................6-16.1 Handover Fault Symptoms..............................................................................................................................6-2

6.1.1 Impacts of Handover Faults on Services................................................................................................6-26.1.2 Alarms Related to Handover Faults.......................................................................................................6-26.1.3 Counters Related to Handover Faults.....................................................................................................6-2

6.2 Handover Troubleshooting Methods...............................................................................................................6-56.2.1 Troubleshooting No or Too Many Handovers Originated by the MS...................................................6-56.2.2 Troubleshooting Destination Cell Congestion Faults............................................................................6-66.2.3 Troubleshooting Hardware Faults..........................................................................................................6-66.2.4 Troubleshooting Inter-BSC or Inter-MSC Handover Failures...............................................................6-76.2.5 Troubleshooting Other Handover Faults................................................................................................6-8

7 Congestion Faults.......................................................................................................................7-17.1 Congestion Fault Symptoms...........................................................................................................................7-2

7.1.1 Impacts of Congestion Faults on Services.............................................................................................7-27.1.2 Alarms Related to Congestion Faults.....................................................................................................7-27.1.3 Counters Related to Congestion Faults..................................................................................................7-3

7.2 Congestion Troubleshooting Methods............................................................................................................7-47.2.1 Troubleshooting High Traffic................................................................................................................7-57.2.2 Troubleshooting Burst Traffic................................................................................................................7-67.2.3 Troubleshooting TRX Faults..................................................................................................................7-67.2.4 Troubleshooting Interference Problems.................................................................................................7-87.2.5 Troubleshooting Insufficient Terrestrial Resources...............................................................................7-97.2.6 Troubleshooting Insufficient Abis Resources........................................................................................7-9

7.3 Typical Cases of Troubleshooting Congestion Faults...................................................................................7-117.3.1 Case: TCH Congestion Due to TRX Faults.........................................................................................7-117.3.2 Case: SDCCH Congestion Due to LAC Configuration Faults............................................................7-11

8 Access Faults...............................................................................................................................8-18.1 Access Fault Symptoms..................................................................................................................................8-2

8.1.1 Impacts of Access Faults on Services....................................................................................................8-28.1.2 Alarms Related to Access Faults............................................................................................................8-28.1.3 Counters Related to Access Faults.........................................................................................................8-3

8.2 Access Troubleshooting Methods...................................................................................................................8-48.2.1 Troubleshooting Um Interface Quality Problems..................................................................................8-48.2.2 Troubleshooting Data Configuration Faults...........................................................................................8-7

8.3 Typical Cases of Troubleshooting Access Faults.........................................................................................8-118.3.1 Case: MS Access Failure Due to Weak Signals...................................................................................8-118.3.2 Case: MS Cell Reselection Failure Due to Weak Signals of Neighboring Cells.................................8-128.3.3 Case: MS Network Disconnection Due to Location Update Period Set Too Small............................8-12

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8.3.4 Case: MS Network Disconnection Due to Incorrect CGI Configuration.............................................8-138.3.5 Case: MS Access Failure Due to Incorrect CBQ/CBA Setting...........................................................8-138.3.6 Case: MS Access Failure Due to Incorrect Setting of Minimum RACH Access Level......................8-14

9 PS Service Faults........................................................................................................................9-19.1 PS Service Fault Symptoms............................................................................................................................9-2

9.1.1 Impacts of PS Service Faults on Services..............................................................................................9-29.1.2 Alarms Related to PS Service Faults......................................................................................................9-29.1.3 Counters Related to PS Service Faults...................................................................................................9-4

9.2 PS Service Troubleshooting Methods...........................................................................................................9-129.2.1 Troubleshooting a Cell Not Supporting GPRS....................................................................................9-139.2.2 Troubleshooting Cell Faults (External PCU).......................................................................................9-149.2.3 Troubleshooting Cell Kickoff Failures (External PCU)......................................................................9-179.2.4 Troubleshooting PDCH Faults (External PCU)...................................................................................9-209.2.5 Troubleshooting LAPD Link Faults (External PCU)...........................................................................9-219.2.6 Troubleshooting Cell Activity State Faults (Built-in PCU).................................................................9-239.2.7 Troubleshooting Cell Service Disruption Faults (Built-in PCU).........................................................9-279.2.8 Troubleshooting Global Service Disruption Faults (Built-in PCU).....................................................9-289.2.9 Commands Executed on the PCU Maintenance Terminal...................................................................9-30

9.3 Typical Cases of Troubleshooting PS Service Faults...................................................................................9-319.3.1 Case: Intermittent LAPD Links............................................................................................................9-329.3.2 Case: Broken Links on the Gb Interface..............................................................................................9-329.3.3 Case: MS GPRS Failure.......................................................................................................................9-339.3.4 Case: Unstable GPRS Download Rate.................................................................................................9-33

10 Cell Broadcast Faults.............................................................................................................10-110.1 Cell Broadcast Fault Symptoms..................................................................................................................10-2

10.1.1 Impacts of Cell Broadcast Faults on Services....................................................................................10-210.1.2 Alarms Related to Cell Broadcast Service Faults..............................................................................10-210.1.3 Counters Related to Cell Broadcast Service Faults............................................................................10-2

10.2 Cell Broadcast Troubleshooting Methods...................................................................................................10-410.2.1 Troubleshooting Disconnection Between the BSC and the CBC......................................................10-510.2.2 Troubleshooting CBS Startup Failures..............................................................................................10-610.2.3 Troubleshooting a Failure to Submit Cell Broadcast Messages to the BSC......................................10-710.2.4 Troubleshooting Incorrect Cell Broadcast Parameter Settings..........................................................10-910.2.5 Troubleshooting Message Reception Failures Caused by the MS...................................................10-1110.2.6 Troubleshooting Incorrect Parameter Setting of the Simple Cell Broadcast...................................10-12

10.3 Typical Cases of Troubleshooting Cell Broadcast Service Faults............................................................10-1210.3.1 Case: CBT/OMT/MMT Login Failure.............................................................................................10-12

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Figures

Figure 1-1 Troubleshooting process.....................................................................................................................1-2Figure 2-1 Collecting BSC local information......................................................................................................2-4Figure 2-2 Backing up server data.......................................................................................................................2-5Figure 2-3 Query Result dialog box.....................................................................................................................2-6Figure 2-4 New Query interface...........................................................................................................................2-6Figure 2-5 Manage Alarm Log File window........................................................................................................2-8Figure 2-6 Create Alarm Log File dialog box......................................................................................................2-9Figure 2-7 Manage Alarm Log File window........................................................................................................2-9Figure 2-8 Upload BSC Log Files window........................................................................................................2-11Figure 2-9 Upload BSC Log Files window........................................................................................................2-11Figure 2-10 BTS Work Log dialog box.............................................................................................................2-12Figure 2-11 Get BTS Compressed Log dialog box............................................................................................2-13Figure 2-12 Monitor Channel Status window....................................................................................................2-19Figure 2-13 Query BSC Board Information dialog box.....................................................................................2-20Figure 2-14 PCUINFO window.........................................................................................................................2-22Figure 2-15 Information items that can be connected through the PCUInfo....................................................2-23Figure 2-16 Obtaining the PCU information......................................................................................................2-23Figure 2-17 Directory of the PCU Info..............................................................................................................2-24Figure 2-18 Um interface tracing Setting dialog box.........................................................................................2-25Figure 2-19 Pb interface tracing Setting dialog box...........................................................................................2-25Figure 2-20 BSSGP cell information tracing Setting dialog box.......................................................................2-26Figure 2-21 BSSGP signaling message tracing Setting dialog box...................................................................2-26Figure 3-1 Cross connection.................................................................................................................................3-5Figure 3-2 Both TX and RX ports being cross-connected...................................................................................3-7Figure 3-3 Cross connection detection.................................................................................................................3-7Figure 4-1 Cell attributes....................................................................................................................................4-17Figure 4-2 Configure Board Attributes dialog box............................................................................................4-20Figure 4-3 Checking the frame format...............................................................................................................4-20Figure 4-4 BSC attributes...................................................................................................................................4-21Figure 4-5 Checking the PCU............................................................................................................................4-22Figure 4-6 Checking the OSP of the SS7 signaling link....................................................................................4-24Figure 4-7 Checking the SS7 signaling link.......................................................................................................4-25Figure 4-8 Modify M3UA Link dialog box.......................................................................................................4-31

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Figure 4-9 Modify M3UA Link dialog box (2)..................................................................................................4-32Figure 4-10 Configure M3UA Entity dialog box...............................................................................................4-34Figure 4-11 Configure M3UA Linkset dialog box.............................................................................................4-35Figure 4-12 Configure M3UA Route dialog box...............................................................................................4-36Figure 4-13 Router configuration.......................................................................................................................4-41Figure 5-1 Query BSC Clock Reference State dialog box.................................................................................5-10Figure 7-1 Site device panel.................................................................................................................................7-7Figure 7-2 Setting Call Control Parameter dialog box.......................................................................................7-10Figure 8-1 Check the kickoff status of the cell.....................................................................................................8-5Figure 8-2 Configure TRX Attributes dialog box................................................................................................8-6Figure 8-3 Configure Frequency Scan dialog box............................................................................................... 8-7Figure 8-4 Set Cell Attributes dialog box............................................................................................................ 8-9Figure 8-5 Parameters related to the cells in idle mode.....................................................................................8-10Figure 8-6 Parameters related to the cell timer..................................................................................................8-10Figure 8-7 Call Control dialog box....................................................................................................................8-15Figure 9-1 Cell attributes....................................................................................................................................9-14Figure 9-2 Site device panel...............................................................................................................................9-16Figure 9-3 Channel attributes.............................................................................................................................9-17Figure 9-4 GPRS cell kickoff procedure............................................................................................................9-18Figure 9-5 Set Cell Attributes dialog box..........................................................................................................9-25Figure 9-6 NS and BSSGP tab page...................................................................................................................9-34Figure 10-1 Configuring BSC attributes............................................................................................................10-8Figure 10-2 Selecting a message........................................................................................................................10-9Figure 10-3 Broadcast scope............................................................................................................................10-10Figure 10-4 Editing the message......................................................................................................................10-11

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Tables

Table 1-1 BSS fault location information form....................................................................................................1-8Table 3-1 Alarm analysis and processing.............................................................................................................3-3Table 3-2 Alarm analysis and processing.............................................................................................................3-4Table 3-3 Noise analysis and processing..............................................................................................................3-4Table 3-4 Noise feature analysis and fault location..............................................................................................3-5Table 4-1 Alarms related to the BTS interface link faults....................................................................................4-3Table 4-2 Alarms related to the BSC interface link faults....................................................................................4-5Table 4-3 Alarms related to the external PCU interface link faults.....................................................................4-7Table 4-4 Counters related to link faults..............................................................................................................4-9Table 4-5 Link troubleshooting methods............................................................................................................4-11Table 5-1 Alarms related to BSC clock faults......................................................................................................5-2Table 5-2 Alarms related to BTS clock faults......................................................................................................5-4Table 5-3 Clock troubleshooting methods............................................................................................................5-5Table 6-1 Counters related to handover faults......................................................................................................6-3Table 6-2 Handover troubleshooting methods.....................................................................................................6-5Table 7-1 Alarms related to BTS congestion faults.............................................................................................7-2Table 7-2 Alarms related to BSC congestion faults.............................................................................................7-3Table 7-3 Counters related to congestion faults...................................................................................................7-3Table 7-4 Congestion troubleshooting methods...................................................................................................7-5Table 8-1 Alarms related to access faults.............................................................................................................8-2Table 8-2 Counters related to access faults..........................................................................................................8-3Table 8-3 Access troubleshooting methods..........................................................................................................8-4Table 9-1 Alarms related to PS service faults (external PCU).............................................................................9-2Table 9-2 Alarms related to PS service faults (built-in PCU)..............................................................................9-3Table 9-3 Counters related to PS service faults (external PCU)..........................................................................9-4Table 9-4 Counters related to PS service faults (built-in PCU)...........................................................................9-6Table 9-5 PS service troubleshooting methods..................................................................................................9-12Table 9-6 Cell kickoff troubleshooting methods................................................................................................9-20Table 9-7 Commands executed on the PCU maintenance terminal...................................................................9-30Table 10-1 Alarms related to cell broadcast service faults.................................................................................10-2Table 10-2 Counters related to cell broadcast service faults..............................................................................10-3Table 10-3 Cell broadcast troubleshooting methods..........................................................................................10-4

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About This Document

PurposeThis document describes the methods of troubleshooting faults when the GBSS equipment is inservice. With this document, the maintenance personnel can solve the following problems:

l Complaints from subscribers

l Faults detected in regular maintenance

l Burst equipment faults

Product VersionThe 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

Intended AudienceThis document is intended for:

l System engineers

l Technical support engineers

l Maintenance engineers

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Change HistoryFor changes in the document, refer to Changes in BSS Troubleshooting Guide.

Organization1 Introduction to BSS Troubleshooting

This introduces the troubleshooting process and common means of fault location. If a fault cannotbe rectified, you can contact Huawei for technical support.

2 Collecting Information for Locating BSS Faults

When a fault occurs to the BSS, you need to collect the fault information as a reference fortroubleshooting. In addition, when you contact Huawei Customer Service Center, provide thefault information for more efficient troubleshooting.

3 Common Faults

This describes the methods of troubleshooting common faults. Through these methods, you candetermine the class, subclass, or specific location of a fault.

4 Link Faults

This describes link faults in terms of the symptoms, troubleshooting methods, and typical cases.

5 Clock Faults

This describes clock faults in terms of the symptoms, troubleshooting methods, and typical cases.

6 Handover Faults

This describes handover faults in terms of the symptoms, troubleshooting methods, and typicalcases.

7 Congestion Faults

This describes congestion faults in terms of the symptoms, troubleshooting methods, and typicalcases.

8 Access Faults

This describes access faults in terms of the symptoms, troubleshooting methods, and typicalcases.

9 PS Service Faults

This describes PS service faults in terms of the symptoms, troubleshooting methods, and typicalcases.

10 Cell Broadcast Faults

This describes cell broadcast faults in terms of the symptoms, troubleshooting methods, andtypical cases.

Conventions1. Symbol Conventions

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

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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.

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.

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[ 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


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 BSS Troubleshooting

About This Chapter

This introduces the troubleshooting process and common means of fault location. If a fault cannotbe rectified, you can contact Huawei for technical support.

1.1 Troubleshooting ProcessThis introduces the troubleshooting process.

1.2 Common Troubleshooting MethodsCommon troubleshooting methods include raw data analysis, alarm information analysis, LEDstatus analysis, dialing test, measurement, performance statistics, interface tracing, common test/loopback test, comparison/interchange, and switchover/reset.

1.3 Huawei Technical SupportYou can obtain Huawei technical support by contacting Huawei technical services center,collecting information associated with a specific fault, or filling in the feedback form fortroubleshooting.

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1-1

1.1 Troubleshooting ProcessThis introduces the troubleshooting process.

Figure 1-1 shows the troubleshooting process.

Figure 1-1 Troubleshooting process

Collect fault information

Start

Determine the scope and type of the fault

Find the causes of the fault

Rectify the fault

Obtain Huawei Technical Support

End

Yes

NoEquipmentand services are

restored?

Collecting Fault Information

Before troubleshooting, you need to collect the following information:

l Fault symptoms

l Fault occurrence time, site, and frequency

l Fault scope and impact

l Operational status of the equipment before the fault occurs

l Operations performed on the equipment before the fault occurs, and the consequence

l Alarms and associated alarms when the fault occurs

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l Status of the LEDs on involved boards

l Measures taken to deal with the fault, and the consequence

You can collect fault information in the following ways:

l Consult the person who reports the fault about the symptom, time, location, and frequencyof the fault.

l Ask the operator of the equipment about the daily running status, failure symptom,operations performed before the fault occurs, and measures taken after the fault occurs andthe consequence.

l Observe board LEDs and the alarm management system on the LMT to obtain informationabout the running status of software and hardware.

l Test the service, measure the performance data, or trace interfaces or signaling messagesto learn the scope of the fault and the impact of the fault on the system.

Determining the Scope and Type of the FaultAfter collecting fault information, you need to analyze the fault symptom to determine the scopeand type of the fault.

The types of BSS faults are as follows:

l 3 Common Faults

l 4 Link Faults

l 5 Clock Faults

l 6 Handover Faults

l 7 Congestion Faults

l 8 Access Faults

l 9 PS Service Faults

l 10 Cell Broadcast Faults

NOTE

l Fault symptoms mentioned in this document are categorized into several classes. For each class, thisdocument provides a series of fault location methods, through which subclasses may be determined.For each subclass, this document provides a series of operations, through which the specific fault causescan be found.

l In addition, this document describes how to analyze and locate common faults, such as one-way audio,no audio, and noise.

Finding the Causes of the FaultBy analyzing and comparing possible causes, find the specific causes of the fault.

Fault location is categorized into two types:

l Location of service-related faults– For a one-way audio, no audio, noise, or PS service fault, check the Abis interface and

Um interface to determine whether the BSS system is faulty. If the BSS system is faulty,continue to locate the fault.

– For a handover fault or an access fault, start signaling tracing and compare the signalingflows with the protocols to locate the fault.



1-3

NOTE

For service-related faults, you can refer to 1.2 Common Troubleshooting Methods to locate thefault.

l Location of faults related to the subsystemsThere are many types of clock faults and link faults. The fault scope, however, is relativelynarrow. Such faults have simple causes. Fault-related information is presented throughboard LEDs, alarms, and error prompts. Based on such information, you can rectify thefault in most cases.

Rectifying the FaultAfter locating the fault, you can start to rectify the fault and restore the system by taking propermeasures, such as checking the cables, replacing the faulty boards, modifying configuration data,switching over a pair of active and standby parts, and resetting the boards.

When rectifying the fault, ensure that:

l Use different procedures for different faults.

l Check the system again after the troubleshooting to ensure that the fault is completelyrectified.

l To avoid the occurrence of similar faults, record the causes of the fault and take preventiveor corrective measures.

Checking the Equipment and ServicesAfter rectifying the fault, check whether the system works properly by checking the status ofboard LEDs and alarm LEDs, and perform dialing tests to ensure that the services are normal.

Contacting the Huawei Customer Service CenterCollect required fault information and contact the Huawei Customer Service Center. For details,refer to 1.3.2 Information Collected for Troubleshooting.

1.2 Common Troubleshooting MethodsCommon troubleshooting methods include raw data analysis, alarm information analysis, LEDstatus analysis, dialing test, measurement, performance statistics, interface tracing, common test/loopback test, comparison/interchange, and switchover/reset.

Raw Data AnalysisRaw data refers to the information reported by the users and other offices, found during themaintenance, and collected by the maintenance engineers in the initial period.

Raw data is used to locate and analyze a fault, especially to determine the impact scope and thecategory of the fault. Raw data can help to narrow the fault scope and locate the fault in theinitial stage of troubleshooting. An experienced maintenance engineer can even locate the faultsimply based on raw data.

Raw data can help service troubleshooting and other types of troubleshooting, especially trunktroubleshooting. The reason is that trunk troubleshooting requires the connection to thetransmission system and the cooperation with the signaling.




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Alarm Information Analysis

Alarm information is provided by the BSS alarm system in the form of sound, light, LED, orscreen display. As a result, alarm information is of great help to analyze and locate a fault.

Alarm information includes the description of the fault or exception, fault causes, and handlingsuggestions. Alarm information relates to many parts of the BSS, including hardware, link, trunk,and CPU load. It is an important key to fault analysis and location.

Alarm information is used to locate the fault and finding out the causes. The BSS alarm systemprovides a huge amount of alarm information, which can be used to locate faults directly ortogether with other means.

LED Status Analysis

An LED reflects the working status of a board, a circuit, a link, an optical path, or a node. TheLED is an important key to fault analysis and location.

The LED status is used to quickly locate the fault and the causes of the fault. Because of limitedinformation, the LED status is often used together with alarm information.

Dialing Test

A dialing test is used to check the call processing function of the BSS and the relevant equipment.It is a simple and quick way of troubleshooting.

Voice services take up a great part of all the services provided by the BSS. As a result, mostfaults related to the BSS have great impacts on calls.

Dialing tests are often used in daily maintenance to determine whether the MS, BTS, BSC, andtrunk system work properly. Dialing tests are also used together with continuous and dynamictracing to test the BSS functions, such as call processing and calling number display.

Measurement

Measurement is a common technical means of BSS troubleshooting. It is widely used in powersupply testing, signaling analysis, waveform analysis, and bit error rate (BER) check. Throughinstruments and meters, you can directly obtain fault-related data.

Performance Statistics

Performance statistics are a means of analyzing the call drop rate.

The call drop rate is an important counter of the BSS. It is affected by many factors and thereforedifficult to predict. Performance statistics can help to find call drop causes in time and preventcall drops effectively

Interface Tracing

Interface tracing is used to analyze the causes of a failure in calling connection or signalingcooperation between offices. Based on tracing results, you can directly locate the causes in mostcases.



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Common Test and Loopback Test

A common test is used to obtain the technical parameters of transmit power, transport channels,or trunk equipment that may be exceptional. Test tools include instruments, meters, and softwaretest tools. Based on test results, you can learn whether a device is faulty or about to be faulty.

A loopback test refers to such a test in which a transmitted signal is returned to the sendingdevice. Loopback is used to observe the functioning of a device or channel, the provisioning ofservices, and the status of signaling flows. With the information, you can determine whetherhardware and software parameters are properly set. Loopback is commonly used to locatetransmission faults and trunk parameter errors. During the process of setting up a new site andexpanding the capacity of trunks, loopback of a BSS trunk can help to determine whether thetrunk and signaling link parameters are properly set.

Common tests and loopback tests are usually used together to locate transmission faults.

Comparison and Interchange

You can compare the symptoms of a faulty part with those of a good one to find out the causes.Comparison is applicable when the fault occurs in a narrow scope.

You can replace the faulty part with a good one to compare the running status of the two partsto determine the scope or location of the fault. Interchange is applicable when the fault occursin a wide scope.

Switchover and Reset

Switchover refers to switching all the services from the active device to the standby device. Bycomparing the running status before and after the switchover, you can determine whether theactive device works properly or whether the active and standby devices cooperate properly.

Reset refers to manually resetting some or all of the devices. Reset is mainly used to rectifysoftware running faults.

Switchover and reset should be used only in emergency. The reasons are as follows:

l Compared with other methods, switchover and reset are auxiliary methods.

l After switchover or reset, the fault symptom seldom appears again within a short period.As a result, the faults cannot be found, which brings potential security and stability risksto the equipment.

l Usually, the reset operation disrupts the ongoing services and even brings the system down.

To avoid data loss, you need to back up the system data before switchover of main control boards.For details, refer to BSS Backup and Recovery Guide.

1.3 Huawei Technical SupportYou can obtain Huawei technical support by contacting Huawei technical services center,collecting information associated with a specific fault, or filling in the feedback form fortroubleshooting.

1. Collect the information necessary for troubleshooting by referring to 1.3.2 InformationCollected for Troubleshooting.




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2. Provide the feedback information to Huawei technical services center according to 1.3.3Fault Location Record Form. For details, refer to 1.3.1 Obtaining Technical Support.

NOTE

If encountered a critical fault, you can first contact Huawei technical services center prior to collecting andproviding the information necessary for troubleshooting.

1.3.1 Obtaining Technical SupportThis describes how to contact Huawei for technical support.

1.3.2 Information Collected for TroubleshootingThe information associated with the occurred fault should be collected before you contactHuawei technical services center in order to facilitate the future troubleshooting.

1.3.3 Fault Location Record FormAfter collecting the location information of the faults, you need to fill in the fault locationinformation form to help the technical services center locate and rectify the faults.

1.3.1 Obtaining Technical SupportThis describes how to contact Huawei for technical support.

Procedurel Dial the customer service number of Huawei: 4008302118 or (+86-755) 2856 0000.l Fax a properly written feedback form to Huawei (0755-28560111) or the local office.

– For an emergent fault, fill in the BSS Emergency Maintenance Notice to providethe feedback information.

– For a non-emergent fault, fill in the 1.3.3 Fault Location Record Form to providethe feedback information.

l Send an E-mail to [email protected] Visit the website http://support.huawei.com for help.

NOTE

For details on how to contact the local office, visit the support website.

----End

1.3.2 Information Collected for TroubleshootingThe information associated with the occurred fault should be collected before you contactHuawei technical services center in order to facilitate the future troubleshooting.

Collecting General Fault InformationThe general fault information to be collected is as follows:

l Full name of the office

l Name and phone number of the contact person

l Time when the fault occurs

l Detailed description of the fault symptoms

l Host software version of the equipment



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mailto:[email protected]

http://support.huawei.com

l Measures taken after the fault occurs and the result

l Severity level of the fault and the time required for rectifying the fault

Collecting Fault Location InformationThe fault location information to be collected is as follows:

l BSC configuration data

l M2000 performance measurement information

l BSC performance measurement information

l BSS alarm information

l BSS log information

l GBAM/GOMU information

l Messages traced on the BSC

l M2000 TRACE files

l Channel status information

l Board bar code information

l Voice tuning information

l External PCU information

For details on the collection of fault location information, refer to 2 Collecting Information forLocating BSS Faults.

1.3.3 Fault Location Record FormAfter collecting the location information of the faults, you need to fill in the fault locationinformation form to help the technical services center locate and rectify the faults.

Table 1-1 describes the fault location information form.

Table 1-1 BSS fault location information form

Please fill in the following blanks in detail:

Office Name Response Time Device Type

Complainer Telephone Host SoftwareVersion

ComplaintTime

WarrantyExpired?

□Yes□No

Fault location information collected:

Information gatherer: Date:

The following contents should be completed by the personnel from Huawei technicalservices center.

Instructional Methods □Telephone-Based Instruction □Remote Maintenance □Onsite Instruction




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Handling result (attachment allowed):

Operator: Date:

Outstanding issue:



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2 Collecting Information for Locating BSSFaults

About This Chapter

When a fault occurs to the BSS, you need to collect the fault information as a reference fortroubleshooting. In addition, when you contact Huawei Customer Service Center, provide thefault information for more efficient troubleshooting.

2.1 Collecting the Local InformationThis describes how to collect the information on the BSC side and BTS side on the BSC6000Local Maintenance Terminal, including mirror of the realtime running of the server, performancestatistics, logs, and alarm logs, so that test personnel can analyze and locate faults.

2.2 Collecting BSC Configuration DataThis describes how to collect BSC configuration data for troubleshooting.

2.3 Collecting M2000 Performance Measurement InformationThis describes how to collect M2000 performance measurement information fortroubleshooting.

2.4 Collecting BSC Performance Measurement InformationThis describes how to collect BSC performance measurement information for troubleshooting.

2.5 Collecting BSS Alarm InformationThis describes how to collect BSS alarm log files and relevant information for troubleshooting.

2.6 Collecting BSS Log InformationThis describes how to collect the log information associated with the BSC, BTS, LMT fortroubleshooting. The information consists of the Operation Log, Debug Log, Running Log,LastWord Log, CHR Log, BTS Log, and Frequency Scan Log.

2.7 Collecting GBAM/GOMU InformationThis describes how to collect GBAM/GOMU information for troubleshooting.

2.8 Collecting Messages Traced on the BSCThis describes how to collect signaling messages and user message on the BSC fortroubleshooting.

2.9 Collecting TRACE Files of the M2000

HUAWEI BSC6000 Base Station SubsystemBSS Troubleshooting Guide 2 Collecting Information for Locating BSS Faults


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This describes how to collect the TRACE files of the M2000 server and M2000 client fortroubleshooting.

2.10 Collecting Channel Status InformationThis describes how to collect the channel status information for troubleshooting.

2.11 Collecting Board Bar Code InformationThis describes how to collect bar code information of a BSC board for troubleshooting.

2.12 Collecting Voice Tuning InformationThis describes how to collect voice tuning information based on the voice symptoms. The voiceproblems involve noise, one-way audio (including no audio and voice discontinuity), and echo.

2.13 Collecting External PCU InformationWhen a fault occurs to the external PCU, you need to collect the fault information as a referencefor troubleshooting. In addition, when you contact Huawei Customer Service Center, providethe fault information for more efficient troubleshooting.

2 Collecting Information for Locating BSS FaultsHUAWEI BSC6000 Base Station Subsystem



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2.1 Collecting the Local InformationThis describes how to collect the information on the BSC side and BTS side on the BSC6000Local Maintenance Terminal, including mirror of the realtime running of the server, performancestatistics, logs, and alarm logs, so that test personnel can analyze and locate faults.

Prerequisitel The LMT runs normally.

l The communication between the LMT and the BSC is normal.

ContextIf the local information is successfully collected, the local information is automatically saved tothe path: LMT installation path\BSC6000\BSC6000V900R008C01\BscObj\BSC Name\LocaleInfo.

The local information is categorized into the following four types:

l Core Dump: mirror file of the realtime running of the server

l Pfm: performance statistics file

l Log: oprlog (operation log), dbglog (debugging log), runlog (running log), lstlog (lastwordlog), chrlog (CHR log), btslog (BTS log), and frqlog (frequency scan log).

l Alarm: alarm log file

Procedure

Step 1 Choose BSC Maintenance > Maintain User Resource > Collect BSC Local Information.

Step 2 Click the Collect BSC Information tab. On the tab page, select Collect BSC localinformation and set the BSC local information.

NOTEYou must select the Collect BSC local information so that you can collect and save the BSC localinformation.

l Click the Collect BTS information tab. On the tab page, select the BTSs of which theinformation needs to be collected.

l Click the Collect File tab. On the tab page, select the files of which the information needsto be collected.

Step 3 Click Execute. The BSC local information is collected, as shown in Figure 2-1.



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Figure 2-1 Collecting BSC local information

Step 4 Click Cancel. Collecting the BSC local information is complete.

----End

2.2 Collecting BSC Configuration DataThis describes how to collect BSC configuration data for troubleshooting.

Prerequisitel The LMT runs properly.

l The BSC is functional.


Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, choose Configuration > Back Up > BackUp Server Data on the menu. A dialog box is displayed, as shown in Figure 2-2.




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Figure 2-2 Backing up server data

Step 2 Click Back up to local. Then, click the button in the File Path on Local area to specify the pathfor saving the data.

Step 3 Click Execute. After the operation is complete, the message Uploading succeeded is displayed.You can obtain the BSC configuration data file specified in Step 2.

----End

2.3 Collecting M2000 Performance MeasurementInformation

This describes how to collect M2000 performance measurement information fortroubleshooting.

Prerequisitel The M2000 runs properly.

l The communication between the M2000 and the BSC is proper.

Procedure

Step 1 On the M2000 Client, choose Performance > Query Result on the menu. A dialog box isdisplayed, as shown in Figure 2-3.



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Figure 2-3 Query Result dialog box

Step 2 Click New Query. A dialog box is displayed, as shown in Figure 2-4.

Figure 2-4 New Query interface

Step 3 In the left pane of the interface, click Object Type or Function Subset in the OrganizationStyle area, in the right pane of the interface, specify the object to be queried, the counters, and




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period on the Object Settings, Counter Settings, and Other Settings tab pages separately.Then, click Query.

Step 4 Click Save Template. The performance measurement result is saved in the form of .XLS.

----End

2.4 Collecting BSC Performance Measurement InformationThis describes how to collect BSC performance measurement information for troubleshooting.

Prerequisitel The communication between the LMT and the GBAM or the GOMU is proper.

l The communication between the Telnet client and the GBAM or the GOMU is proper.

Procedure

Step 1 Start the Telnet client, such as PuTTY Software, on the PC. Then, enter the IP address of theGBAM and GOMU, and log in to the GBAM or GOMU as user root.

Step 2 Double-click the Internet Explorer icon and run the IP address (in the format of \\XXX.XXX.XXX.XXX) of the GBAM to connect the GBAM server or the GOMU.

NOTE

If the Samba service is not started, run the rcsmb start command to start the service.

Step 3 Double-click the BSC6000 folder. Type User Name and Password, and then click Yes.

Step 4 Copy all the files under the BSC6000\data\mtndata\pfm directory to the local hard disk.

NOTE

If you are prompted to obtain specific rights in coping the files, run the chmod 777 /BSC6000 -R commandto change the read-and-write authority. After the files are copied, run the chmod 755 /BSC6000 -Rcommand to recover the read-and-write authority.

----End

2.5 Collecting BSS Alarm InformationThis describes how to collect BSS alarm log files and relevant information for troubleshooting.

2.5.1 Collecting BSS Alarm Log FilesThis describes how to collect BSS alarm log files and upload the log files to the LMT.

2.5.2 Collecting BSS Alarm InformationThis describes how to collect BSS alarm information for troubleshooting.

2.5.1 Collecting BSS Alarm Log FilesThis describes how to collect BSS alarm log files and upload the log files to the LMT.



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l The communication between the LMT and the alarm box is normal.

Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, choose Alarm Maintenance > ManageAlarm Log File on the menu. A window is displayed, as shown in Figure 2-5.

Figure 2-5 Manage Alarm Log File window

Step 2 Click Create. A dialog box is displayed, as shown in Figure 2-6. Specify the period duringwhich the fault occurs, and then generate the log file.




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Figure 2-6 Create Alarm Log File dialog box

Step 3 After the log file generation succeeds, if you click Query in Figure 2-5, all the alarm log filesthat are generated and saved in the server are displayed, as shown in Figure 2-7.

Figure 2-7 Manage Alarm Log File window

Step 4 Select the alarm log file that you want to upload it to the LMT PC, and then click Upload. Thealarm log file is uploaded to the path BscObj\Office Name\Alm in the LMT installationdirectory.

----End



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2.5.2 Collecting BSS Alarm InformationThis describes how to collect BSS alarm information for troubleshooting.

Prerequisitel The communication between the LMT and the GBAM or the GOMU is proper.

l The communication between the Telnet client and the GBAM or the GOMU is proper.

Procedure

Step 1 Start the Telnet client, such as PuTTY Software, on the PC. Then, enter the IP address of theGBAM and GOMU, and log in to the GBAM or GOMU as user root.

Step 2 Double-click the Internet Explorer icon and run the IP address (in the format of \\XXX.XXX.XXX.XXX) of the GBAM to connect the GBAM server or the GOMU.

NOTE

If the Samba service is not started, run the rcsmb start command to start the service.

Step 3 Double-click the BSC6000 folder. Type User Name and Password, and then click Yes.

Step 4 Copy all the files under the BSC6000\data\datafile directory to the local hard disk.

NOTE

If you are prompted to obtain specific rights in coping the files, run the chmod 777 /BSC6000 -R commandto change the read-and-write authority. After the files are copied, run the chmod 755 /BSC6000 -Rcommand to recover the read-and-write authority.

----End

2.6 Collecting BSS Log InformationThis describes how to collect the log information associated with the BSC, BTS, LMT fortroubleshooting. The information consists of the Operation Log, Debug Log, Running Log,LastWord Log, CHR Log, BTS Log, and Frequency Scan Log.

2.6.1 Collecting BSC Log FilesThis describes how to collect BSC log files for troubleshooting.

2.6.2 Collecting BTS Log FilesThis describes how to collect BTS log files for troubleshooting.

2.6.3 Collecting LMT Log FilesThis describes how to collect LMT log files for troubleshooting.

2.6.1 Collecting BSC Log FilesThis describes how to collect BSC log files for troubleshooting.






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Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, choose BSC Maintenance > MaintainLogs > Upload BSC Log Files on the menu. A window is displayed, as shown in Figure 2-8.

Figure 2-8 Upload BSC Log Files window

Step 2 Specify the Log Type and then click Query. The query result is shown in Figure 2-9.

Figure 2-9 Upload BSC Log Files window



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Step 3 In the query result, select the log file to be uploaded and specify its upload path. Then, clickUpload to upload the log file to the path BscObj\Office Name\BscLog in the LMT installationdirectory.

----End

2.6.2 Collecting BTS Log FilesThis describes how to collect BTS log files for troubleshooting.



l The communication between the BSC and the BTS is normal.

NOTE

The following steps are taken as examples for logging in to the server.

Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, choose BTS Maintenance > Maintain Site> BTS Work Log. A dialog box is displayed, as shown in Figure 2-10.

Figure 2-10 BTS Work Log dialog box

The three options available in Figure 2-10 are described as follows:

l Get BTS logs to GBAM.If this option is selected, the BTS log is saved in the directory IP address of the GBAM\bsc6000\data\mtndata\log\dbg\btslog.After the log is saved to the server, the log saved to the BTS is deleted automatically. Youcan retrieve the BTS log files saved to the GBAM through the LMT. For the detailedoperations, refer to 2.6.1 Collecting BSC Log Files.

l Get BTS Compressed Log.If this option is selected, the BTS log is compressed before it is saved to the path BscObj\Office Name\CompressLog in the LMT installation directory.




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l Browse BTS Log.If this option is selected, the parameters such as site, board type, board No., start time, andend time should be specified in order to have the specific log information displayed.

CAUTIONThe BSC extracts BTS logs and saves them on the server. You can obtain these logs on theserver, and then these logs saved in the BTS are deleted. When other two methods are used toobtain logs, the logs saved in the BTS still exist.

Step 2 Click Get BTS Compressed Log, and then click OK. A dialog box is displayed, as shown inFigure 2-11.

Figure 2-11 Get BTS Compressed Log dialog box

Step 3 In Figure 2-11, specify the parameters such as Site Name, Start Time, and End Time. Then,click Start. If the progress bars in the Progress area show that the operation is complete, amessage is displayed, prompting you that the log extraction succeeds. The default directory onthe LMT for saving the compressed BTS log, BscObj\Office Name\CompressLog, isdisplayed.

NOTE

You can use a log interpretation tool to view the log file.

----End



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2.6.3 Collecting LMT Log FilesThis describes how to collect LMT log files for troubleshooting.



Procedure

You can get the LMT log files from the LMT installation directory \BscObj\Office Name\LmtLog.

----End

2.7 Collecting GBAM/GOMU InformationThis describes how to collect GBAM/GOMU information for troubleshooting.

2.7.1 Collecting Information About the GBAM ModelThis describes how to collect the information about the GBAM model from its label.

2.7.2 Collecting Running Information About the GBAM/GOMU Local ProcessesThis describes how to collect the running information about the GBAM/GOMU local processesfor troubleshooting.

2.7.3 Collecting Running Information About the GBAM/GOMU Core ProcessesThis describes how to collect the running information about the GBAM/GOMU core processesfor troubleshooting.

2.7.4 Collecting Other Information About the GBAM/GOMUThis describes how to collect other information about the GBAM/GOMU for troubleshooting.

2.7.1 Collecting Information About the GBAM ModelThis describes how to collect the information about the GBAM model from its label.

Procedure

Search for the white label attached to the GBAM shell. The literature following HUAWEI, suchas C5201 SERVER, is the GBAM model.

----End

2.7.2 Collecting Running Information About the GBAM/GOMULocal Processes

This describes how to collect the running information about the GBAM/GOMU local processesfor troubleshooting.




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Context

CAUTIONIf the operations described below are performed, the local processes of the GBAM/GOMU willbe restarted. Thus, you are not advised to perform these operations except that the local processesof the GBAM/GOMU are faulty and need to be restarted.

Procedure

Step 1 Start the Telnet client, such as PuTTY Software, on the PC. Enter the IP address of the GBAM/GOMU, and then log in to the GBAM/GOMU as the root user.

Step 2 Run the cd /BSC6000/coredump command to visit the directory that saves the error informationassociated with the GBAM/GOMU.

Step 3 Run the pkill -8 pomu_local.bin command to generate the omulocal.0000.core.1.gz file.

Here, 0000 indicates the subrack number and slot number of the GOMU, and 1 indicates thecount of the recorded abnormal information. This file is large is size (it may be 2 GB); thus, itsgeneration might take several minutes. You can run the ll command to query the file size. If thefile size becomes stable, you can infer that the file is successfully generated. Perform theoperations in Step 4 to compress the file.

Step 4 Run the gzip omulocal.0000.core.1.gz command to generate the compressed file, say, omulocal.0000.local.1.gz.

This file is generally several decades of MB in size. You can copy the file from the path IPaddress of the GBAM/GOMU\bsc6000\coredump.

----End

2.7.3 Collecting Running Information About the GBAM/GOMUCore Processes

This describes how to collect the running information about the GBAM/GOMU core processesfor troubleshooting.

Context

CAUTIONIf the operations described below are performed, the core processes of the GBAM/GOMU willbe restarted. Thus, you are not advised to perform these operations except that the core processesof the GBAM/GOMU are faulty and need to be restarted.



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Procedure

Step 1 Start the Telnet client, such as PuTTY Software, on the PC. Enter the IP address of the GBAM/GOMU, and then log in to the GBAM/GOMU as the root user.

Step 2 Run the cd /BSC6000/coredump command to visit the directory that saves the error informationassociated with the GBAM/GOMU.

Step 3 Run the pkill -8 pomu_core.bin command to generate the omucore.0000.core.1.gz file.

Here, 0000 indicates the subrack number and slot number of the GOMU, and 1 indicates thecount of the recorded abnormal information. This file is large is size (it may be 2 GB); thus, itsgeneration might take several minutes. You can run the ll command to query the file size. If thefile size becomes stable, you can infer that the file is successfully generated. Perform theoperations in Step 4 to compress the file.

Step 4 Run the gzip omucore.0000.core.1.gz command to generate the compressed file, say, omucore.0000.core.1.gz.

This file is generally several decades of MB in size. You can copy the file from the path IPaddress of the GBAM/GOMU\bsc6000\coredump.

----End

2.7.4 Collecting Other Information About the GBAM/GOMUThis describes how to collect other information about the GBAM/GOMU for troubleshooting.

ContextNOTE

You can get other information about the GBAM/GOMU from the shared directory of the GBAM/GOMU.

Procedurel To get the history operation information about the user, do as follows:

1. Start the Telnet client, such as PuTTY Software, on the PC. Enter the IP address ofthe GBAM/GOMU, and then log in to the GBAM/GOMU as the root user.

2. Run the cp .bash_history /BSC6000/install command to copy the .bash_history fileto the shared directory of the GBAM/GOMU.

3. Visit the .bash_history file in the directory IP address of the GBAM/GOMU/users/bsc6000/install to get the history operation information about the user.

l To get the information about the abnormal restart of the GBAM/GOMU, do as follows:1. Start the Telnet client, such as PuTTY Software, on the PC. Enter the IP address of

the GBAM/GOMU, and then log in to the GBAM/GOMU as the root user.2. Visit the core.********* file in the directory IP address of the GBAM/GOMU/

bsc6000/bscswm/omuroot to get the information about the abnormal restart of theGBAM/GOMU.

NOTE

This file is generated automatically by the system when the OMU process is restartedabnormally.

l To get the login information about the shared directory of the GBAM/GOMU, do asfollows:




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2. Run the cd /var/log/samba command to enter the /var/log/samba directory.3. Run the cp log.smbd /BSC6000 command to copy the log.smbd file to the shared

directory of the GBAM/GOMU.4. Visit the log.smbd file in the directory IP address of the GBAM/GOMU/users/

bsc6000 to get the login information about the shared directory of the GBAM/GOMU.l To get the information about the Ethernet cards of the GBAM/GOMU, do as follows:


2. Run the lspci | grep Ethernet command. After the result is displayed, capture it usinga relevant application, and save it for future use.

----End

2.8 Collecting Messages Traced on the BSCThis describes how to collect signaling messages and user message on the BSC fortroubleshooting.



l The communication between the BSC and the MSC is normal.

ContextTwo types of messages are available for tracing: signaling messages and user messages.

l Signaling messages– The interface-related signaling messages involve those traced on the A interface, Abis

interface, Um interface, BSC_CBC interface, Pb interface for the external PCU, and Gbinterface for the built-in PCU.

– The link-related messages involve those traced on the BSSAP, SCCP, MTP2, MTP3,SCTP, M3UA, RSL, OML, ESL, EML, and LAPD.

l User messagesThe user messages are concerned with the continuity procedures and status of the user.

ProcedureFor the detailed operations, refer to Configuring Message Tracing.

----End

2.9 Collecting TRACE Files of the M2000This describes how to collect the TRACE files of the M2000 server and M2000 client fortroubleshooting.



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Procedurel Collect the TRACE file of the M2000 server.

1. Visit the directory IP address of the M2000 server/export/home/omc/var/logsthrough FTP.

2. Find the TRACE file of the M2000, iMAP.XXXX.trace, in the previous directory.The history TRACE files are saved in the tracebak folder of the same directory. Here,XXXX indicates the name of an M2000 process.

NOTE

A history trace file is named as follows: iMAP.XXXX.trace.20061123155759.tar.gz. Here,20061123155759 indicates the time when the file is generated.

CAUTIONTo obtain an interpretable TRACE file through FTP, set the FTP download mode tobinary.

l Collect the TRACE file of the M2000 client.

You can get the TRACE file of the M2000 client from the installation directory of theM2000 client, \client\tracefile.

NOTE

A TRACE file of the M2000 client is named as follows: DebugTrace_2007-06-12_14-24-44.txt.Here, 14-24-44 indicates the time when the file is generated.

----End

2.10 Collecting Channel Status InformationThis describes how to collect the channel status information for troubleshooting.




Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, choose BTS Maintenance > MonitorChannel Status on the menu.

Step 2 In the displayed window, specify the Site, Cell, and TRX in the Operation Object. Then, clickStart. The channel status information is displayed, as shown in Figure 2-12.




Issue 01 (2008-06-10)

Figure 2-12 Monitor Channel Status window

Step 3 Use a relevant application to capture the result, and save it for future use.

----End

2.11 Collecting Board Bar Code InformationThis describes how to collect bar code information of a BSC board for troubleshooting.



Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, choose BSC Maintenance > MaintainDevice > Query BSC Board Information on the menu. A dialog box is displayed, as shownin Figure 2-13.



2-19

Figure 2-13 Query BSC Board Information dialog box

Step 2 In the Board Location area, specify the Subrack No., Board Type, and Slot No. of a board.Then, on the Board Information tab page, click Query to get the bar code information aboutthe board.

Step 3 Use a relevant application to capture the result, and save it for future use.

----End

2.12 Collecting Voice Tuning InformationThis describes how to collect voice tuning information based on the voice symptoms. The voiceproblems involve noise, one-way audio (including no audio and voice discontinuity), and echo.

Procedurel During the tuning phase, collect the information associated with noise and one-way audio

(including no audio and voice continuity) problems as follows:– Check the number of noise occurrences during a call and the characteristics of the noise,

such as the clicking sound and the metal sound.– Check whether the noise occurs regularly, say, every x seconds or every x minutes. If

the noise does not occur regularly, check whether the noise persists during the call.




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– Check whether the amplitude of the noise is even, such as the volume fluctuation.– Approximate the ratio of the noise amplitude to the normal voice strength.– Check whether the noise is sharp than the voice.– Check whether the symptom such as one-way audio, no audio, or voice discontinuity

occurs during the conversation. One-way audio means that only one party can hear thevoice from the other end of the line. No audio means both parties fail to hear the voicefrom the peer. Voice discontinuity means that the voice is interrupted irregularly duringthe conversation.

– The occurrences of the one-way audio are of the following types:The one-way audio symptom occurs after the call is put through and persists during theconversation (excluding the long call put-through failure). The one-way audio symptomoccurs after a period of normal conversation, and persists until the call is hanged up.The one-way audio symptom also occurs after a period of normal conversation, andthen disappears.

l During the tuning phase, collect the information associated with the echo problem asfollows:– Test place and BTS type– Models and MSISDNs of the MSs that hear the echoes from the peer end– Local echo volume (compared with the peer voice volume)– Space condition of the peer MS (whether the MS is in a spacious place, near a wall, or

in a narrow room)– Ambient environment of the peer MS (noisy or quiet)– Peer volume fluctuation and the fluctuation of the echo heard by the local party– Fluctuation of the echo heard by the local party once the speaker at the peer is blocked– Fluctuation of the echo heard by the local party once the peer party is under an inter-

BTS handover– Fluctuation of the echo heard by the local party once the peer party is under an inter-

BSC handover– Whether the echo persists even through the peer party walks out of the room or its

ambient voice volume changes

----End

2.13 Collecting External PCU InformationWhen a fault occurs to the external PCU, you need to collect the fault information as a referencefor troubleshooting. In addition, when you contact Huawei Customer Service Center, providethe fault information for more efficient troubleshooting.

2.13.1 Collecting PCUINFO InformationThis describes how to collect PCU system information and PCU resource information.

2.13.2 Collecting Messages Traced on the External PCUThis describes how to collect the signaling messages on the Um, Pb, and Gb interfaces.

2.13.1 Collecting PCUINFO InformationThis describes how to collect PCU system information and PCU resource information.



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Prerequisitel The PCUInfo application is running.

l The Telnet terminal is started.

l The FTP terminal is started.

Procedure

Step 1 Double-click PCUInfo.exe.

Step 2 On the PCUInfo, choose Capture > Capture on the menu. Figure 2-14 shows the PCUINFOwindow.

Figure 2-14 PCUINFO window

Step 3 Set the parameters on the PCUInfo.1. Enter the IP address of the PCU in the POMU IP ADDR text box.2. In the PCU System Info and PCU Res Info areas, click the check boxes of the items to be

collected.




Issue 01 (2008-06-10)

Figure 2-15 Information items that can be connected through the PCUInfo

3. In the Alarm and DbgAlm text boxes, set the start date and end date, as shown in Figure2-15.

NOTE

l The information in the PCU System Info and PCU Res Info areas is obtained through Telnet.

l The information in the FTP Files Setting area is obtained from the PCU hard disk through FTP.

Step 4 Click Start to obtain information.l If the PCUInfo is connected to the PCU, a dialog box is displayed, as shown in Figure

2-16. This indicates that the PCUInfo can obtain the required information.l If the PCUInfo fails to be connected to the PCU. Check whether the network connection is

proper and whether the IP address of the PCU is correct.

Figure 2-16 Obtaining the PCU information

Step 5 After obtaining the PCU information, click OK to save the PCU information to the sub-folderin the PCU Info folder. The PCU information is named in the Info+the current date format, asshown in Figure 2-17.



2-23

Figure 2-17 Directory of the PCU Info

Step 6 Click Exit.

----End

2.13.2 Collecting Messages Traced on the External PCUThis describes how to collect the signaling messages on the Um, Pb, and Gb interfaces.

Prerequisitel The PCU LocalWS is started.

l The communication between the PCU LocalWS and the PCU is proper.

l The communication between the Telnet terminal and the PCU is proper.

Context

The signaling tracing of the PCU is performed on the PCU LocalWS. The interfaces consist ofthe Um interface, Pb interface, and Gb interface.

Procedurel Trace messages on the Um interface.

1. Start the PCU LocalWS. In the Maintenance window, choose Tracing > UmInterface Tracing on the menu. A dialog box is displayed, as shown in Figure2-18.




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CAUTIONWhen tracing messages on the Um interface, you must clear the option Filter datablock.

Figure 2-18 Um interface tracing Setting dialog box

2. Set the parameters. Create a task to trace the Um interface messages of the test cell.

NOTE

You can query the Cell No. and TRX No. by running the command mt pdch show attrLCNo all in the Telnet terminal.

l Trace messages on the Pb interface.1. Start the PCU LocalWS. In the Maintenance window, choose Tracing > Pb

Interface Tracing on the menu. A dialog box is displayed, as shown in Figure2-19.

CAUTIONWhen tracing the messages on the Pb interface, click all the check boxes.

Figure 2-19 Pb interface tracing Setting dialog box

2. Set the parameters. Create a task to trace the Pb interface messages of the test cell.



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NOTE

The Cell No. must be the same as that specified in the Um interface tracing.

l Trace the Gb interface (BSSGP CELL) signaling messages.

1. Start the PCU LocalWS. In the Maintenance window, choose Tracing > BSSGPCell Message Tracing on the menu. A dialog box is displayed, as shown in Figure2-20.

Figure 2-20 BSSGP cell information tracing Setting dialog box

2. Specify the Cell ID. Create a task to trace on the Gb interface the BSSGP cellinformation messages of the test cell.

NOTE

You can query the Cell ID by running the command pcu show lcc LCNo in the Telnet terminal.

l Trace the Gb interface (BSSGP SIG) messages.

1. Start the PCU LocalWS. In the Maintenance window, choose Tracing > BSSGPSignaling Message Tracing on the menu. A dialog box is displayed, as shown inFigure 2-21.

Figure 2-21 BSSGP signaling message tracing Setting dialog box

2. Specify the NSEI. Create a task to trace on the Gb interface the BSSGP messages ofthe test cell.

NOTE

You can query the NSEI by running the command Cell show CellID in the Telnet terminal.

l Save signaling messages.

1. After creating the tracing tasks on the Um, Pb, and Gb interfaces, save the messagestraced on the interfaces.

2. You should trace the signaling on the three interfaces simultaneously. After the test,save the signaling tracing messages as a .gmt file. If the .gmt file is too large, youshould compress it into a .rar file.

----End




Issue 01 (2008-06-10)

3 Common Faults

About This Chapter

This describes the methods of troubleshooting common faults. Through these methods, you candetermine the class, subclass, or specific location of a fault.

3.1 Troubleshooting One-Way Audio or No AudioThis describes how to troubleshoot one-way audio or no audio. One-way audio means that onlyone party in a call can hear the voice. No audio means that no party in a call can hear the voice.Generally, one-way audio or no audio occurs when a speech channel segment is faulty. The faultcan be rectified on the BSC6000 Local Maintenance Terminal.

3.2 Troubleshooting NoisesThis describes how to troubleshoot noises, such as the bubble sound, clicking sound, and metalsound, that appear during a call. In some cases, noises are so serious that the voices cannot beheard clearly. Noises are usually caused by error bits.

3.3 Troubleshooting Cross Connection FaultsThis describes how to troubleshoot the faults in cross connection. The fault symptoms show thatthe E1/T1 wires at one end are mismatched with the TX/RX ports, thus disconnecting the upper-level links.

HUAWEI BSC6000 Base Station SubsystemBSS Troubleshooting Guide 3 Common Faults


3-1

3.1 Troubleshooting One-Way Audio or No AudioThis describes how to troubleshoot one-way audio or no audio. One-way audio means that onlyone party in a call can hear the voice. No audio means that no party in a call can hear the voice.Generally, one-way audio or no audio occurs when a speech channel segment is faulty. The faultcan be rectified on the BSC6000 Local Maintenance Terminal.

Possible CausesThe possible causes of one-way audio or no audio are as follows:

l Engineering connection problem– E1/T1 lines carried by the GEIUT are connected improperly. For example, they are

cross connected.– E1/T1 lines on the A interface are connected improperly. For example, they are cross

connected.l Data configuration problem

– Circuit configuration on the BSC side is inconsistent with that on the MSC side.

– On the BSC side, timeslots for carrying signaling are configured as ones for carryingservices.

l Hardware faultA board, backplane, transmission line, or connector through which voice signals pass isfaulty.

l Radio link interferenceRadio link interference is mainly caused by the radio environment. For example,unbalanced UL and DL levels may lead to poor quality in one way or interference in theuplink and the downlink.

l Clock faultA clock fault usually occurs in a clock source.

l MS faultAn MS fault usually lies in the MS itself.

Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, perform a remote loopback on the speechchannel during a call. Here, set MSISDN to the called number and Loop Location to GE(O)IUA. For detailed operations, refer to Looping Back Remote Speech Channel.l If the Loop Direction is To BTS, you can infer that the speech channel on the BSC side is

operational if you (the calling party) can hear your own voice through the MS.l If the Loop Direction is To MSC, you can infer that the speech channel on the MSC side

is operational if you (the calling party) can hear your own voice through the MS.l If the fault occurs on the BSC side, go to Step 2; otherwise, go to Step 3 and Step 4.

Step 2 During a call, test the internal speech channel on the BSC6000 Local MaintenanceTerminal to check whether the TDM switching on the GTNU is normal. For detailed operations,refer to Testing the Internal Speech Channel.

3 Common FaultsHUAWEI BSC6000 Base Station Subsystem



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l If normal, go to Step 3.l If abnormal, contact the Huawei Customer Service Center by referring to 1.3.1 Obtaining

Technical Support.

Step 3 During a call, check the speech channel resources on the BSC6000 Local MaintenanceTerminal by referring to Querying the Resources of An MS. The resources include the boards,ports, and timeslots that carry the Abis, Ater, TC, and ACIC resources.

Step 4 Based on the ACIC information obtained in Step 3, check whether the configuration of the ACICport on the BSC side is consistent with that on the MSC side and whether the physical connectionis consistent with the configuration.

Step 5 Based on the Ater resource information obtained in Step 3, check whether there are crossconnections on the Ater interface and whether the physical connection is consistent with theconfiguration.

Step 6 Based on the Ater resource information obtained in Step 3, check whether the Ater timeslots forthe speech channel are used for other purposes.

Step 7 Check whether an alarm about the speech channel is reported. If such an alarm is reported,perform the corresponding processing by referring to Table 3-1.

Table 3-1 Alarm analysis and processing

System Alarm Type Analysis Processing

Link alarm Possibly caused by a linkfault

4 Link Faults

Interference alarm Possibly caused by radiolink interference, whichincreases the bit error rateon the radio link

7.2.4 TroubleshootingInterference Problems

Clock alarm Caused by frame slipping orframe loss

5 Clock Faults

Step 8 If the fault persists, contact the Huawei Customer Service Center by referring to 1.3.1 ObtainingTechnical Support.

----End

3.2 Troubleshooting NoisesThis describes how to troubleshoot noises, such as the bubble sound, clicking sound, and metalsound, that appear during a call. In some cases, noises are so serious that the voices cannot beheard clearly. Noises are usually caused by error bits.

Possible Causes

The possible causes of bit errors that lead to noises are as follows:

l Fault in a board, connector, or line through which voice signals pass



3-3

l Grounding fault

l Radio link interference

l Clock fault

l Mismatching between the settings of DIP switch on the DTMU of the BTS and the actualtype (75 ohms or 120 ohms) of the transmission cable

Procedure

Step 1 If an alarm is reported, perform the corresponding analysis and processing by referring to Table3-2.

Table 3-2 Alarm analysis and processing

System Alarm Type Analysis Fault Rectification

Link alarm Possibly caused by radio linkinterference, which increasesthe bit error rate on the radiolink

l 4 Link Faults

l 7.2.4 TroubleshootingInterference Problems

Clock alarm Caused by frame slipping orframe loss

5 Clock Faults

If no such an alarm is reported, go to Step 2.

Step 2 Perform the corresponding noise analysis and processing by referring to Table 3-3.

Table 3-3 Noise analysis and processing

Noise Location Analysis Fault Rectification

Only within the coverage of aBTS

Make test calls by using theMS to determine the specificlocation, such as a timeslot, afrequency, or the entirecoverage of the BTS.

l For a frequency problem,check the status of theTRX.

l For a BTS problem,check the transmissionlines within the BTS.

Within the coverage of theBSC

- Check the transmissionlines within the BSC.

Within the coverage of theMSC

- Check the transmissionlines within the MSC.

Step 3 If the alarm persists, perform the corresponding analysis and locate the fault by referring toTable 3-4.




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Table 3-4 Noise feature analysis and fault location

Noise Feature Analysis Location

Noises and voices aretransmitted at the same timein superimposition-likeformat. Between them, noisesare not fluctuated greatly.

Error bits on thetransmission lines affect thesample values of PCM.

Error bits exist on the MSCside.

Some words cannot be heardclearly. There are someabnormal sounds such as thebubble sound, clicking sound,and metal sound.

Compressed voice signalsmust be decompressedbefore being sent to thereceiver. Thedecompression leads togreatly fluctuated noises.

Error bits exist within theBSC. Rectify the fault basedon the specific symptom andthe corresponding rectificationmethod.

Noises occur at regularintervals during a call.

Frame slipping or frameloss due to a clock faultoccurs at regular intervals,such as every severalseconds.

5 Clock Faults

Step 4 Check whether the settings of the DIP switch on the DTMU of the BTS are consistent with thetype (75 ohms or 120 ohms) of the transmission cable.


----End

3.3 Troubleshooting Cross Connection FaultsThis describes how to troubleshoot the faults in cross connection. The fault symptoms show thatthe E1/T1 wires at one end are mismatched with the TX/RX ports, thus disconnecting the upper-level links.

Fault SymptomsIn cross connection, the E1/T1 port can receive signals from the physical layer and no alarm isgenerated, but the signals are sent by a wrong E1/T1 port at the peer end. Therefore, the upper-level links are broken. Figure 3-1 shows the cross connection.

Figure 3-1 Cross connection

E1/T1 A E1/T1 ARX Port

E1/T1 BE1/T1 B

E1/T1 A E1/T1 A

E1/T1 BE1/T1 B

Correct connection

RX Port

RX Port

RX Port

RX Port

RX Port

RX Port

RX Port

TX Port

TX Port

TX Port

TX Port

TX Port

TX Port

TX Port

TX Port

Cross connection



3-5

Detection MethodsThere are two methods to detect cross connection faults, namely, loopback detection and alarm-based detection.

l Loopback detectionPerform loopback on the remote E1/T1 port, and then check the data consistency betweenthe TX port and the RX port that are connected by the E1/T1 cables.– If the data is consistent between the TX port and the RX port, the E1/T1 cables are

connected correctly.– If the data is inconsistent between the TX port and the RX port, the E1/T1 cables are

cross-connected.The loopback detection is of two types, remote loopback and physical loopback.– Remote loopback applies when the GMPS/GEPS is directly connected to the GTCS

through the E1/T1 cables. In this scenario, you can run MML commands to performremote loopback on the remote E1/T1 ports.

– Physical loopback applies when the devices are connected through the DDF. In thisscenario, you can short-circuit the RX/TX ports on the DDF for the E1/T1 cables byusing conversion connectors to form a self-loop.

CAUTIONPhysical loopback detection is applied to only the ports that carry the Ater OM links.

The loopback detection is performed during site deployment or upgrade. The advantage ofloopback detection is that ports can be detected in batches and faults in cross connectionscan be located effectively. The disadvantage of loopback detection is that physical or remoteloopback must be performed on the DDF or remote E1/T1 port.

l Alarm-based detectionDisable the transmit function of the local E1/T1 port to enable the remote port to generatethe alarm 20081 Loss of E1/T1 Signals (LOS), and then add the Remote Alarm Indication(RAI) to the alarm.– If the E1/T1 cables are connected correctly, the local E1/T1 port can receive the RAI.

– If the E1/T1 cables are connected incorrectly, the local E1/T1 port does not generateany alarm.

The alarm-based detection is used to locate the fault when one-way audio occurs duringsite maintenance, or when loopback cannot be performed during site deployment. Theadvantage of alarm-based detection is that loopback is not performed on the remote E1/T1ports. The disadvantage of alarm-based detection is that you can only check whether theE1/T1 cables are connected correctly but cannot acquire port information or detect the portsin batches.

RestrictionsThe restrictions of cross connection are as follows:

l Only the E1/T1 ports on the EIUa can be detected, but the optical ports on the OIUa cannotbe detected.




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l Only whether cross connection exists can be detected, but the fact that both TX and RXports are cross-connected, as shown in Figure 3-2, cannot be detected.

Figure 3-2 Both TX and RX ports being cross-connected

E1/T1 A E1/T1 ARX Port

E1/T1 BE1/T1 BRX Port

RX Port

RX Port

TX Port

TX Port

TX Port

TX Port

l If the E1/T1 cables are wrongly connected and the RX and TX ports on the DDF form aself-loop, the loopback detection cannot find out whether cross connection exists.

l If the boards are in active/standby mode, the cross connection detection can be performedonly on the active board instead of the standby board.

l When the E1/T1 interface board works in active/standby mode, the alarm-based detectionrequires the Y-shaped E1/T1 cables.

l The local E1/T1 ports to be detected have no alarms generated.

l No loopback is performed on the local E1/T1 ports to be detected.

l If the loopback detection is used, it must be performed on the remote E1/T1 port.

l If the alarm-based detection is used, you must ensure that no loopback is performed on theremote E1/T1 port.

l The loopback detection supports the single-port test and board test, whereas the alarm-based detection supports only the single-port test. Neither detection can be used tosimultaneously test multiple ports on a board or simultaneously test multiple boards.

ProcedureFor details of how to perform loopback detection and alarm-based detection, refer to Check E1/T1 Cross Connection(CHK E1T1CRS). Figure 3-3 shows the interface.

Figure 3-3 Cross connection detection



3-7

CAUTIONl Cross connection detection may disrupt the service temporarily. It is recommended that you

test cross connection during site deployment or upgrade.l You cannot run the commands for testing cross connection repeatedly. Instead, you must run

another command after the previous test is completed.

----End




Issue 01 (2008-06-10)

4 Link Faults

About This Chapter

This describes link faults in terms of the symptoms, troubleshooting methods, and typical cases.

4.1 Link Fault SymptomsThis describes the impacts of link faults on services, possible alarms, and involved performancecounters.

4.2 Link Troubleshooting MethodsThis describes how to troubleshoot different types of link faults. Basically, when a link is faulty,first deal with the reported alarm, then determine the subclass of the fault, and finally rectify thefault.

4.3 Typical Cases of Troubleshooting Link FaultsThis describes the typical cases of troubleshooting link faults.

HUAWEI BSC6000 Base Station SubsystemBSS Troubleshooting Guide 4 Link Faults


4-1

4.1 Link Fault SymptomsThis describes the impacts of link faults on services, possible alarms, and involved performancecounters.

4.1.1 Impacts of Link Faults on ServicesThis describes the impacts of different link faults on services.

4.1.2 Alarms Related to Link FaultsThis describes the BSS alarms caused by link faults. The alarms help locate and rectify the faults.

4.1.3 Counters Related to Link FaultsThis describes the counters related to link faults. The counters can help locate and rectify thefaults.

4.1.1 Impacts of Link Faults on ServicesThis describes the impacts of different link faults on services.

OML/EML FaultsWhen the operation and maintenance link (OML) or extended maintenance link (EML) is faulty,neither voice services nor data services can be provided for the MSs in the coverage of the BTS.

RSL/ESL FaultsWhen the radio signaling link (RSL) or extended signaling link (ESL) is faulty, the impacts areas follows:

l If the BCCH TRX is faulty and the TRX aid function is not configured, neither voiceservices nor data services can be provided for the MSs in the cell.

l If a non-BCCH TRX is faulty, neither voice services nor data services can be provided forthe MSs occupying the TRX channel.

PBSL FaultsWhen the PCU is configured outside the BSC, the impacts of PCU-BSC signaling links (PBSLs)are as follows:

l When all the PBSLs are faulty, data services cannot be provided for the MSs controlled bythe BSC.

l When some PBSLs are faulty, the capacity of data services of the BSC decreases.

SS7 Signaling Link FaultsSS7 signaling link faults affect signaling transmission directly and voice services indirectly. Thespecific impacts are as follows:

l When all the SS7 signaling links break down, all the MSs drop calls.

l When some SS7 signaling links break down, the loads on other SS7 signaling links increasebut not all the MSs drop calls.

4 Link FaultsHUAWEI BSC6000 Base Station Subsystem



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Ater Signaling Link Faults

Ater signaling link faults directly affect voice services. The specific impacts are as follows:

l When all the Ater signaling links break down, all the MSs drop calls.

l When some Ater signaling links break down, the loads on other links increase but not allthe MSs drop calls.

Ater OML Faults

When the Ater OML is faulty in BM/TC separated mode, no operation or maintenance for theremote GTCS can succeed.

SIGTRAN Link Faults

Signaling transport (SIGTRAN) link faults affect IP signaling transmission on the A interfacedirectly and voice services indirectly. The specific impacts are as follows:

l When all the SIGTRAN links break down, all the MSs drop calls.

l When some SIGTRAN links break down, the loads on other SIGTRAN links increase butnot all the MSs drop calls.

Abis Interface IP Link Faults

When the IP link on the Abis interface is faulty, neither voice services nor data services can beprovided for all the MSs in the coverage of the BTS.

4.1.2 Alarms Related to Link FaultsThis describes the BSS alarms caused by link faults. The alarms help locate and rectify the faults.

Alarms Related to BTS Interface Link Faults

Table 4-1 lists the alarms related to the BTS interface link faults.

Table 4-1 Alarms related to the BTS interface link faults

Fault Cause Site Type Alarm Name

Line fault ortransmission modulefault

BTS3X 2114 LAPD Alarm

2214 E1 Local Alarm

2216 E1 Remote Alarm

2218 AIS Alarm

2452 E1 Outboard Alarm

2454 E1 Inboard Alarm

BTS3001C 3052 LAPD alarm

3152 E1 Local alarm



4-3

Fault Cause Site Type Alarm Name

3154 E1 Remote alarm

3190 Optical Receive Channel alarm

3192 Optical Transmit Channel alarm

3194 ASU E1 Port alarm

BTS3002C 3572 LAPD alarm

3672 E1 Local alarm

3674 E1 Remote alarm

3794 Optical Receive Channel Alarm

3796 Optical Transmit Channel Alarm

3798 IASU E1 Port Alarm

3800 IASU Cock Source Lost alarm

Double-transceiver BTS

4102 LAPD Alarm

4714 E1 Local Alarm

4716 E1 Remote Alarm

4718 AIS Alarm

4836 E1 Port Illegal Alarm



7400 IASU E1 Port Alarm

7402 IASU Cock Source Lost Alarm

7404 IASU Crystal Oscillator Alarm



7512 E1 Outboard Alarm

7514 E1 Inboard Alarm

Alarms Related to BSC Interface Link FaultsTable 4-2 lists the alarms related to the BSC interface link faults.




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Table 4-2 Alarms related to the BSC interface link faults

Fault Cause Alarm Name

E1/T1 fault or optical port fault 21205 Board Fault

20081 Loss of E1/T1 Signals (LOS)

20082 Loss of E1/T1 Frames (LOF)

20083 Remote E1/T1 Alarm (RAI)

20084 E1/T1 Alarm Indication Signal (AIS)

20085 Loss of E1/T1 Multiframes (LOM)

20086 E1/T1 Link Loopback

20087 High BER over the E1/T1 Link

20089 Excessive Loss of E1/T1 Signals in anHour

20090 Excessive E1/T1 SynchronizationFailures in an Hour

20091 E1/T1 Excessive Peer End Alarms PerHour

20092 E1/T1 Excessive Bit Error Rate PerHour

20093 E1/T1 Excessive Slip Frames Per Hour

20222 Loss of Signals on the Optical Port(RLOS)

20223 Loss of Received Signal Frames on theOptical Port (RLOF)

20224 Out-of-Synchronization of ReceivedSignal Frames on the Optical Port (ROOF)

20225 Mismatch of Trace Byte of theRegenerator Section on the Optical Port(RTIM)

20226 Regenerator Section Signal Failure(RSF)

20227 Regenerator Section SignalDeteriorated (RSD)

20228 Multiplex Section Alarm IndicationSignal (MAIS)

20229 Multiplex Section Remote DefectIndication (MRDI)

20230 Loopback on the Optical Port



4-5


20231 Administration Unit Alarm IndicationSignal (AUAIS)

20232 Loss of Administration Unit Pointer(AULOP)

20239 Loss of Tributary Unit Multi-frames(TULOM)

20240 Tributary Unit Alarm IndicationSignal (TUAIS)

20241 Loss of Tributary Unit Pointer(TULOP)

20248 Loss of Tributary Signals (LOS)

20249 Tributary Alarm Indication Signal(AIS)

20250 Loss of Tributary Frames (LOF)

20251 Remote Alarm Indication over theTributary (RAI)

20252 Loss of Tributary Multi-Frames(LOM)

20253 Slip Frame over the Tributary

20254 Tributary Loopback Alarm

20255 Optical Module Fault

Transmission fault 21001 LAPD Link Congestion

21002 Broken LAPD Link

21501 MTP3 DSP Unreachable

21502 MTP3 Layer 3 Congestion

21503 MTP3 Link Unavailable

21504 MTP3 Signaling Link2 Congestion

21512 MTP3 Link Test Failure

21513 MTP2 Link Location Failure

21514 MTP2 Link Service Disrupted

21516 Route Transmission on the MTP3Prohibited

20081 Loss of E1/T1 Signals (LOS)

21525 SCCP DSP Unreachable




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21526 SCCP Subsystem Prohibited

21528 Remote SCCP Fault

21531 Lack of SCCP Connection Resources

21551 Ater OML Broken Alarm

102 Disrupted Connection with the CBC

103 All SS7 Links Faulty

104 All PBSLs in the PCU Are Faulty

129 MSC Resetting

1000 LAPD OML Fault

21551 Ater OML Broken Alarm

701 M3UA Link Fault

702 M3UA Link Congestion

703 M3UA Route Unvailable

704 M3UA Destination Entity Unvailably

705 FG2/GOU Route Status Unavailable

Alarms Related to External PCU Interface Link FaultsTable 4-3 lists the alarms related to the external PCU interface link faults.

Table 4-3 Alarms related to the external PCU interface link faults

Fault Type Alarm Name

E1/T1 fault or optical port fault 20081 Loss of E1/T1 Signals (LOS)


20083 Remote E1/T1 Alarm (RAI)

20084 E1/T1 Alarm Indication Signal (AIS)

20085 Loss of E1/T1 Multiframes (LOM)

20086 E1/T1 Link Loopback

20087 High BER over the E1/T1 Link

20089 Excessive Loss of E1/T1 Signals in anHour



4-7



20091 E1/T1 Excessive Peer End Alarms PerHour

20092 E1/T1 Excessive Bit Error Rate PerHour

20093 E1/T1 Excessive Slip Frames Per Hour

20222 Loss of Signals on the Optical Port(RLOS)

20223 Loss of Received Signal Frames on theOptical Port (RLOF)

20224 Out-of-Synchronization of ReceivedSignal Frames on the Optical Port (ROOF)

20225 Mismatch of Trace Byte of theRegenerator Section on the Optical Port(RTIM)

20226 Regenerator Section Signal Failure(RSF)

20227 Regenerator Section SignalDeteriorated (RSD)

20228 Multiplex Section Alarm IndicationSignal (MAIS)

20229 Multiplex Section Remote DefectIndication (MRDI)

20230 Loopback on the Optical Port

20231 Administration Unit Alarm IndicationSignal (AUAIS)

20232 Loss of Administration Unit Pointer(AULOP)

20239 Loss of Tributary Unit Multi-frames(TULOM)

20240 Tributary Unit Alarm IndicationSignal (TUAIS)

20241 Loss of Tributary Unit Pointer(TULOP)

20248 Loss of Tributary Signals (LOS)




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20249 Tributary Alarm Indication Signal(AIS)

20250 Loss of Tributary Frames (LOF)

20251 Remote Alarm Indication over theTributary (RAI)

20252 Loss of Tributary Multi-Frames(LOM)

20253 Slip Frame over the Tributary

20254 Tributary Loopback Alarm

20255 Optical Module Fault

Transmission fault 21001 LAPD Link Congestion



105 ONE PBSL Link SINGLE PASS

106 PCIC CHECK IS INCONSISTENT

128 No Circuit Configured in the PCU

4.1.3 Counters Related to Link FaultsThis describes the counters related to link faults. The counters can help locate and rectify thefaults.

Table 4-4 lists the counters related to link faults.

Table 4-4 Counters related to link faults

Counter Description

L5012 I Frames Discarded by LAPD Link

L5007 I Frames Resent on LAPD Link

L0486 Disruptions of the BSC-CBC Connection

L0056A Number of MSC Resets

L6002 Out-of-Service Duration of MTP3 Link

L6003 Duration of MTP3 Link Fault

L6004 Duration of MTP3 Link Local Inhibition

L6005 Duration of MTP3 Link Remote Inhibition



4-9

Counter Description

L6006 Duration of MTP3 Link Remote Processor Fault

L6007 Duration of MTP3 Link Congestion

L6008 MTP3 Link Failures for All Reasons

L6009 MTP3 Link Local Inhibitions

L6010 MTP3 Link Remote Inhibitions

L6011 MTP3 Link Remote Processor Failures

L6012 MTP3 Link Local Switchovers

L6015 MTP3 Link Congestions

RL7009 Ratio of CREF by Peer SCCP

RL7010 Ratio of CREF by Peer SCCP

AL1251 Mean Number of Faulty Circuits on the AterInterface

AL0051 Mean Number of Faulty Circuits on the A Interface

AL0053 Mean Number of Blocked Circuits on the AInterface

AL8351 Mean Number of Faulty Circuits on the PbInterface

AL8353 Mean Number of Blocked Circuits on the PbInterface

L0031 SCTP Link Retransmission Thunks

L0032 SCTP Link Received Error Packets

L0033 SCTP Link Sent Thunks

L0034 SCTP Link Received Thunks

L0035 SCTP Link Sent Packets

L0036 SCTP Link Received Packets

L0021 M3UA Link Failure Times

L0022 M3UA Link Failure Duration

L0023 M3UA Link Congestion Duration

L0024 M3UA Link Sent Packets

L0025 M3UA Link Received Packets

L01001 Received Bytes

L01002 Received Packets




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Counter Description

L01003 Sent Bytes

L01004 Sent Packets

L01005 Error Sent Packets

SC010A CS Packets Sent over FE Port of the PTU

SC000A CS Packets Received over FE Port of the PTU

SC011A PS Packets Sent over FE Port of the PTU

SC001A PS Packets Received over FE Port of the PTU

SC012A Control-Plane Packets Sent over FE Port of the PTU

SC003A Error CRC Packets Received over FE Port of thePTU

4.2 Link Troubleshooting MethodsThis describes how to troubleshoot different types of link faults. Basically, when a link is faulty,first deal with the reported alarm, then determine the subclass of the fault, and finally rectify thefault.

Procedure

Step 1 Deal with the reported alarm according to the alarm help.

Step 2 If the alarm persists, determine the subclass of the fault and take the corresponding measure, aslisted in Table 4-5.

Table 4-5 Link troubleshooting methods

Fault Location Fault Rectification

On the BSC6000 Local MaintenanceTerminal, check the status of LAPD links.The result shows that the State of an OMLis Failure.

4.2.1 Troubleshooting OML Faults

On the BSC6000 Local MaintenanceTerminal, check the status of LAPD links.The result shows that the State of an EMLis Failure.

4.2.2 Troubleshooting EML Faults



4-11


On the BSC6000 Local MaintenanceTerminal, check the status of LAPD links.The result shows that the State of an RSLis Failure. In addition, the Subrack area onthe BTS Device Panel shows that the TRXboard is faulty.

4.2.3 Troubleshooting RSL Faults

On the BSC6000 Local MaintenanceTerminal, check the status of LAPD links.The result shows that the State of an ESLis Failure.

4.2.4 Troubleshooting ESL Faults

On the BSC6000 Local MaintenanceTerminal, check the status of LAPD links.The result shows that the State of a PBSLis Failure.

4.2.5 Troubleshooting PBSL Faults

On the BSC6000 Local MaintenanceTerminal, check the status of SCCPconnections. The result shows that theDestination signaling point state of anSCCP connection is Prohibit.

4.2.6 Troubleshooting SS7 Signaling LinkFaults

On the BSC6000 Local MaintenanceTerminal, check the status of MTP3 links.The result shows that the ServiceTransmit of an MTP3 link is Not using.

On the BSC6000 Local MaintenanceTerminal, check the status of MTP2 links.The result shows that the Link State of anMTP2 link is Start Locating.

On the Local Maintenance Terminal,check the status of Ater signaling links.The result shows that an Ater signalinglink is faulty.

4.2.7 Troubleshooting Ater Signaling LinkFaults

On the BSC6000 Local MaintenanceTerminal, check the status of Ater OMLs.The result shows that the AvailableStatus of some or all HDLC links is Notavailable.

4.2.8 Troubleshooting Ater OML Faults

On the Local Maintenance Terminal,check the status of M3UA links. The resultshows that the Link State of an M3UAlink is the non-activated or invalid state.

4.2.11 Troubleshooting M3UA Link Faults

On the Local Maintenance Terminal,check the status of M3UA routes. Theresult shows that the Access Flag of anM3UA route is Unavailable.

4.2.12 Troubleshooting M3UA RouteUnavailability Faults




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On the Local Maintenance Terminal,check the status of M3UA destinationentities. The result shows that the AccessFlag of an M3UA destination entity isInaccessible.

4.2.13 Troubleshooting M3UA DestinationEntity Inaccessibility Faults

On the BSC6000 Local MaintenanceTerminal, check the status of LAPD links.The result shows that the State of an OML,EML, RSL, or ESL is Failure.

4.2.14 Troubleshooting Abis Interface IPLink Faults


----End

4.2.1 Troubleshooting OML FaultsThis describes how to troubleshoot OML faults. When an OML is faulty, neither voice servicesnor data services can be provided for the MSs in the coverage of the BTS.

Fault Symptoms

The State of an OML is Failure, which you can check on the BSC6000 Local MaintenanceTerminal by referring to Maintaining LAPD Links. An alarm 1000 LAPD OML Fault isreported. Multiple cells are out of service. Neither voice services nor data services can beprovided for the MSs in the coverage of the BTS.

Possible Causes

The possible causes of OML faults are as follows:

l The GEIUB/GOIUB is faulty.

l The GXPUT is faulty.

l The GXPUM is faulty.

l The configured BTS type is inconsistent with the actual one.

l The port configured for the BTS is inconsistent with the actual one.

l The BTS main control board is faulty.

l The BTS is not powered.

l The BTS has a transmission failure.

Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, view the alarm information.l Check whether a power-off alarm exists. If existent, rectify the fault by referring to 4.1.2

Alarms Related to Link Faults.



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l Check whether an E1/T1 transmission alarm exists. If existent, rectify the fault by referringto 4.2.9 Troubleshooting E1/T1 Transmission Faults.

l If no such an alarm exists, go to Step 2.

Step 2 By referring to Querying BTS Board Information, check whether the BTS main control boardis faulty.l If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.l If not faulty, go to Step 3.

Step 3 By referring to Querying the Status of an Interface Board Port, check whether the E1/T1 portin connection with the BTS is faulty.l If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.l If not faulty, go to Step 4.

Step 4 By referring to Querying BSC Board Information, check whether the GEIUB/GOIUB,GXPUT, and GXPUM are faulty.l If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.l If not faulty, go to Step 5.

Step 5 Check the configured BTS type.1. On the BSC6000 Local Maintenance Terminal, click the corresponding TRX on the

Management Tree tab page.2. In the Site Description area on the Site Device Panel tab page, check whether the

configured Site Type is consistent with the actual one.l If inconsistent, remove this BTS and then reconfigure it by referring to Configuring

the BTS.l If consistent, go to Step 6.

Step 6 Check the number of the E1/T1 port in connection with the BTS.1. On the BSC6000 Local Maintenance Terminal, click the corresponding TRX on the

Management Tree tab page.2. In the Site Description area on the Site Device Panel tab page, check whether the GEIUB

Subrack No., GEIUB Slot No., and GEIUB Port No. are consistent with the actual ones.l If the settings are incorrect, move the BTS by referring to . Alternatively, connect the

corresponding port on the DDF and the configured port.l If the settings are correct but the fault persists, contact the Huawei Customer Service

Center by referring to 1.3.1 Obtaining Technical Support.

----End

4.2.2 Troubleshooting EML FaultsThis describes how to troubleshoot EML faults. When the EMLs are faulty, neither voice servicesnor data services can be provided for the MSs in the coverage of the BTS.

Fault SymptomsOn the BSC6000 Local Maintenance Terminal, the query result shows that the State of anEML is Failure. For details, refer to Maintaining LAPD Links. The alarms 1000 LAPD OMLFault and 11270 LAPD Alarm are reported. Multiple cells are out of service. Neither voiceservices nor data services can be provided for the MSs in the coverage of the BTS.




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Possible CausesThe possible causes of the EML fault are as follows:

l The GEHUB board is faulty.

l The GXPUT is faulty.


l The configured BTS type is inconsistent with the actual BTS type.

l The port configured for the BTS is inconsistent with the actual one.

l The BTS main control board is faulty.

l The BTS is not powered.

l The BTS has a transmission failure.

Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, view the alarm information.l Check whether a power-off alarm exists. If existent, rectify the fault by referring to 4.1.2

Alarms Related to Link Faults.l Check whether an E1/T1 transmission alarm exists. If existent, rectify the fault by referring

to 4.2.9 Troubleshooting E1/T1 Transmission Faults.l If not existent, go to Step 2.

Step 2 Check whether the BTS board is faulty by referring to Querying BTS Board Information.l If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.l If not faulty, go to Step 3.

Step 3 By referring to Querying the Status of an Interface Board Port, check whether the E1/T1 portin connection with the BTS is faulty.l If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.l If not faulty, go to Step 4.

Step 4 Check whether the GEHUB, GXPUT, and GXPUM are faulty by referring to Querying BSCBoard Information.l If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.l If not faulty, go to Step 5.

Step 5 Check the configured BTS type.1. On the BSC6000 Local Maintenance Terminal, click the corresponding TRX on the

Management Tree tab page.2. In the Site Description area on the Site Device Panel tab page, check whether the

configured Site Type is consistent with the actual one.l If inconsistent, remove this BTS and then reconfigure it by referring to Configuring

the BTS.l If consistent, go to Step 6.

Step 6 Check the number of the E1/T1 port in connection with the BTS.1. On the BSC6000 Local Maintenance Terminal, click the corresponding TRX on the

Management Tree tab page.



4-15

2. In the Site Description area on the Site Device Panel tab page, check whether the GEHUBSubrack No., GEHUB Slot No., and GEHUB Port No. are consistent with the actualones.l If inconsistent, move the BTS by referring to . Alternatively, connect the DDF cable to

the data configuration port.l If consistent, go to Step 7.

Step 7 On the BSC6000 Local Maintenance Terminal, browse the HDLC path data in the BTS data,and check whether 31 timeslots are configured for the HDLC path. For details, refer to BrowsingConfiguration Data.l If the number of configured timeslots is not 31, reconfigure this BTS. For details of

configuring timeslots, refer to Timeslots on the Abis Interface.l If the number of configured timeslots is 31 but the fault persists, contact the Huawei

Customer Service Center by referring to 1.3.1 Obtaining Technical Support.

----End

4.2.3 Troubleshooting RSL FaultsThis describes how to troubleshoot RSL faults. When an RSL is faulty, neither voice servicesnor data services can be provided for the MSs in the cell.

Fault SymptomsThe RSL fault symptoms are as follows:

l The State of an RSL is Failure, which you can check on the BSC6000 Local MaintenanceTerminal by referring to Maintaining LAPD Links.

l On the BSC6000 Local Maintenance Terminal, the Cabinet area of the Site DevicePanel shows that the TRX board is faulty.

l On the BSC6000 Local Maintenance Terminal, an alarm 2204 TRX CommunicationAlarm or 405 Cell Out of Service is reported. Neither voice services nor data services canbe provided for the MSs in the cell.

NOTE

When the BCCH TRX is faulty, the TRX aid function works. TRX aid can take effect only when it isconfigured for the cell. For detailed operations, refer to Configuring TRX Cooperation.

Possible CausesThe possible causes of RSL faults are as follows:

l The corresponding OML is not operational.

l The DTRU is faulty.

Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, view the alarm information.l If a TRX fault alarm such as 2204 TRX Communication Alarm is reported, rectify the

fault by referring to 4.1.2 Alarms Related to Link Faults.l If no such an alarm is reported, go to Step 2.




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Step 2 Check the status of the involved links by referring to Maintaining LAPD Links.l If the OML is faulty, rectify the fault by referring to 4.2.1 Troubleshooting OML

Faults.l If the RSL is faulty, go to Step 3.

Step 3 Check the TRX configuration.1. On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, click

the cell. A dialog box is displayed, as shown in Figure 4-1.

Figure 4-1 Cell attributes

2. Check the frequency.

Select the TRX from the Assigned TRXs area, and then check whether the correspondingfrequency in the Frequencies area is consistent with that supported by the TRX.

l If the setting is incorrect, replace the TRX board or modify the frequency. For detailsabout how to modify frequencies, refer to Configuring the Multiband Network.

l If the setting is correct but the fault persists, contact the Huawei Customer ServiceCenter by referring to 1.3.1 Obtaining Technical Support.

----End

4.2.4 Troubleshooting ESL FaultsThis describes how to troubleshoot ESL faults. When the ESLs are faulty, neither voice servicesnor data services can be provided for the MSs in the cell.



4-17

Fault Symptoms

On the BSC6000 Local Maintenance Terminal, query the status of the LAPD link. The resultshows that the State of the ESL is Failure. For details, refer to Maintaining LAPD Links. Analarm 2114 LAPD Alarm is reported. Multiple cells are out of service and neither voice servicesnor data services can be provided for all the MSs in the coverage of the BTS.

Possible Causes

The possible causes of the ESL faults are as follows:

l The GEHUB board is faulty.

l The DPTU board is incorrectly installed or cabled.

Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, view the alarm information.

l Check whether the TRX fault-related alarms such as 2204 TRX Communication Alarmexist. If existent, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.

l If not existent, go to Step 2.

Step 2 Check whether the GEHUB/GFGUB board is faulty by referring to Querying BSC BoardInformation.

l If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.

l If not faulty, go to Step 3.

Step 3 Check whether the cable is correctly connected to the E1 port on the DPTU board. The correctway is to connect the E1 cable at the top of the cabinet to the E1 port on the DPTU board.

l If the cable is connected incorrectly, reconnect the cable in the correct way as mentionedpreviously.

l If the cable is connected correctly, go to Step 4.

Step 4 Check whether the DPTU board is inserted in a correct slot. The correct location is slot 3 or 4of subrack 0.

l If the board is inserted in a wrong slot, reinsert the board in the correct location as mentionedpreviously.

l If the board is inserted correctly but the fault persists, contact the Huawei Customer ServiceCenter by referring to 1.3.1 Obtaining Technical Support.

----End

4.2.5 Troubleshooting PBSL FaultsThis describes how to troubleshoot PBSL faults. When a PBSL is faulty, PS services cannot beprovided for the MSs or the capacity of PS services decreases.

Fault Symptoms

The State of a PBSL is Failure, which you can check on the BSC6000 Local MaintenanceTerminal by referring to Maintaining LAPD Links.




Issue 01 (2008-06-10)

Possible CausesThe possible causes of PBSL faults are as follows:

l The GEIUB/GOIUB is faulty.


l A transmission fault occurs.

l The E1 frame format on the external PCU side is inconsistent with that on the BSC side.

l The timeslot configured on the BSC side is inconsistent with that configured on the externalPCU side.

Procedure

Step 1 By referring to Querying BSC Board Information, check whether the GEIUB/GOIUB andGXPUM in connections with the BTS are faulty.l If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.l If not faulty, go to Step 2.

Step 2 By referring to Querying the Status of an Interface Board Port, check whether E1/T1 port ofthe PBSL is faulty.l If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.l If not faulty, go to Step 3.

Step 3 Check the Port Attributes in the Configure Board Attributes dialog box of the GEIUP/GOIUP. Set the Frame Format to DOUBLE_FRAME.

NOTE

The frame format on the PCU side is set to DOUBLE_FRAME.

1. Right-click the GEIUP/GOIUP on the BSC Device Panel, and then select ConfigureBoard Attributes from the shortcut menu. A dialog box is displayed, as shown in Figure4-2.



4-19

Figure 4-2 Configure Board Attributes dialog box

2. Click Next. A dialog box is displayed, as shown in Figure 4-3.

Figure 4-3 Checking the frame format

3. Set the Frame Format shown in Figure 4-3 to DOUBLE_FRAME.

Step 4 Check whether the Timeslot No. of the PBSL on the BSC side is consistent with the SignalingLink Timeslot No. of the PBSL on the external PCU side.l Check the timeslot number of the signaling link on the external PCU side.




Issue 01 (2008-06-10)

On the PCU LocalWS, check the Signaling Link Timeslot No. on the PCU side by runningthe pcu show e1slot command.

l Check the Timeslot No. of the PBSL on the BSC side.

1. On the Management Tree tab page of the BSC6000 Local Maintenance Terminal,right-click the root node BSC6000, and then click the BSC Attributes tab. The tab pageis displayed, as shown in Figure 4-4.

Figure 4-4 BSC attributes

2. Click PCU in the Other Data area. In the displayed dialog box, click the Pb SignalingLink tab, as shown in Figure 4-5.



4-21

Figure 4-5 Checking the PCU

3. Click Refresh to check the Timeslot No. of the PBSL.

Based on the query result, do as follows:

l If the configured timeslot number is inconsistent with the actual one, change the TimeslotNo. of the PBSL on the BSC6000 Local Maintenance Terminal or PCU LocalWS.

l If consistent, go to Step 5.

Step 5 On the PCU LocalWS, check the status of the PBSL link and perform the correspondingoperations.

1. Run the command mt lapd show state {<BoardNo> all}|<LapdNo>|<LapdName> tocheck the status of the PBSL.

l If the administrative status of the PBSL is Blocked, run the command mt lapd unblock{<BoardNo> all}|<LapdNo>|<LapdName> to unblock the PBSL. The PBSL shouldbe restored to the Enabled state. If not restored, go to Step 5.2.

l If the administrative status of the PBSL is Unblocked, end the troubleshooting.

2. Run the command Mt lapd port show state <BoardNo> <HLPU/L2PUNo> to check thestatus of the port on the L2PU/HLPU that carries the PBSL.

l If the LoopMode of the port carrying the PBSL is local loopback or remote loopback,run the command mt lapd port loop set <BoardNo> <PortNo> <LoopMode> to setLoopMode to NoLoop. The status of the PBSL should be restored to ENABLED. Ifnot restored, go to Step 5.3.




Issue 01 (2008-06-10)

l If the LoopMode of the port carrying the PBSL is NoLoop, end the troubleshooting.

3. Rectify the PBSL fault by referring to 9.2.5 Troubleshooting LAPD Link Faults(External PCU).

----End

4.2.6 Troubleshooting SS7 Signaling Link FaultsThis describes how to troubleshoot SS7 signaling link faults. When all the SS7 signaling linksconfigured for the BSC break down, all the MSs drop calls. When some links break down, theloads on other links increase but not all the MSs drop calls.

Fault Symptoms

The fault symptoms of SS7 signaling links are as follows:

l The Destination signaling point state of an SCCP link is Prohibit, which you can checkon the BSC6000 Local Maintenance Terminal by referring to Maintaining the SCCP.

l The Service Transmit of an MTP3 link is Not using, which you can check on the BSC6000Local Maintenance Terminal by referring to Maintaining MTP3 Links.

l The Link State of an MTP2 link is Start Locating, which you can check on the BSC6000Local Maintenance Terminal by referring to Querying Status of MTP2 Links.

l An alarm 21525 SCCP DSP Unreachable or 21501 MTP3 DSP Unreachable is reported,which you can check on the BSC6000 Local Maintenance Terminal. The ongoingservices are disrupted.

l The alarm 21514 MTP2 Link Service Disrupted is cleared immediately after it isgenerated. Intermittence may lead to call drops.

Possible Causes

The possible causes of SS7 signaling link faults are as follows:

l The SS7 signaling link is not operational.

l The SS7 signaling link breaks down.

l The SS7 signaling link is disconnected intermittently.

NOTE

Assume that the peer MSC runs properly.

Procedurel If the SS7 signaling link is not operational, do as follows:

1. By referring to Querying BSC Board Information, check whether the GXPUM,GEIUT/GOIUT, and GEIUA/GOIUA that carry the SS7 signaling link are faulty.– If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.

– If not faulty, go to Step 2.

2. On the BSC6000 Local Maintenance Terminal, click the BSC Attributes tab. Inthe Other Data area, click SS7 Signaling Point. A dialog box is displayed, as shownin Figure 4-6.



4-23

Figure 4-6 Checking the OSP of the SS7 signaling link

3. Check whether the settings of OPC, Encoding Scheme, Network Indicator, andDPC are consistent with those on the MSC side.– If inconsistent, delete the settings and then reconfigure the parameters by referring

to Configuring the SS7 Signaling Points.– If consistent, go to Step 4.

4. On the BSC6000 Local Maintenance Terminal, click the BSC Attributes tab. Inthe Other Data area, click SS7 Signaling Link. A dialog box is displayed, as shownin Figure 4-7.




Issue 01 (2008-06-10)

Figure 4-7 Checking the SS7 signaling link

5. Check whether the settings of A Timeslot Mask, SLC, and SLC Send are consistentwith those on the MSC side.

– If inconsistent, delete the settings and then reconfigure the parameters by referringto Adding an SS7 Signaling Link.

– If consistent, go to Step 6.

6. By referring to Querying the Status of an Interface Board Port, check whether theE1/T1 port that resides on the A interface and carries the SS7 signaling link is faulty.

– If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.


7. By referring to Querying the Status of an Interface Board Port, check whether theE1/T1 port that resides on the Ater interface and carries the SS7 signaling link is faulty.If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.

l If the SS7 signaling link breaks down, do as follows:

1. By referring to Querying BSC Board Information, check whether the GXPUM,GEIUT(GOIUT), and GEIUA(GOIUA) that carry the SS7 signaling link are faulty.



2. By referring to Querying the Status of an Interface Board Port, check whether theE1/T1 port that resides on the A interface and carries the SS7 signaling link is faulty.



4-25



3. By referring to Querying the Status of an Interface Board Port, check whether theE1/T1 port that resides on the Ater interface and carries the SS7 signaling link is faulty.If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.

l If the SS7 signaling link is disconnected intermittently, do as follows:

1. On the BSC6000 Local Maintenance Terminal, check whether there is an alarm21514 MTP2 Link Service Disrupted that is cleared immediately after it is generated.

– If there is, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.

– If the fault persists, go to Step 2.

2. If the fault persists, contact the Huawei Customer Service Center by referring to 1.3.1Obtaining Technical Support.

----End

4.2.7 Troubleshooting Ater Signaling Link FaultsThis describes how to troubleshoot the faults in the Ater signaling links. The fault symptomsshow that if all the Ater signaling links are broken, all the MSs incur call drops; if a few Atersignaling links are broken, the link load increases and no MSs incur call drops; if the Atersignaling links are overloaded, the call loss increases.

Fault Symptoms

Check the status of the Ater signaling links on the Local Maintenance Terminal. For details,refer to List LAPD Link(LST LAPDLNK) and List Ater Signaling Link(LST ATERSL).On the BSC6000 Local Maintenance Terminal, by querying the alarm information you canfind that the 21002 Broken LAPD Link alarm is reported.

Possible Causes

The possible causes of the faults in Ater signaling links are as follows:

l In BM/TC separated mode, the GEIUT/GOIUT in the GMPS or remote GTCS is faulty.

l A transmission fault occurs on the Ater interface.

Procedure

Step 1 Check whether the GEIUT/GOIUT that carries the Ater signaling links is faulty. For details,refer to Querying BSC Board Information.

l If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.


Step 2 Check whether the E1/T1 port that carries the Ater OM links is faulty. For details, refer toQuerying the Status of an Interface Board Port. If faulty, rectify the fault by referring to4.1.2 Alarms Related to Link Faults.

----End




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4.2.8 Troubleshooting Ater OML FaultsThis describes how to troubleshoot Ater OML faults. When all Ater OMLs break down, nooperation or maintenance for the remote subracks can be performed.

Fault SymptomsThe Available Status of some or all HDLC links is Not available, which you can check on theBSC6000 Local Maintenance Terminal by referring to Querying the Status of the AterOML. In addition, an alarm 21551 Ater OML Broken Alarm is reported. If all the Ater OMLsbreak down, no operation or maintenance for the remote subracks can be performed.

Possible CausesThe possible causes of Ater OML link faults are as follows:

l In BM/TC separated mode, the GEIUT/GOIUT in the GMPS or remote GTCS is faulty.

l A transmission fault occurs on the Ater interface.

Procedure

Step 1 By referring to Querying BSC Board Information, check whether the GEIUT/GOIUT carryingthe Ater OML is faulty.l If faulty, rectify the fault by referring to 4.1.2 Alarms Related to Link Faults.l If not faulty, go to Step 2.

Step 2 By referring to Querying the Status of an Interface Board Port, check whether the E1/T1 portof the Ater OML is faulty. If faulty, rectify the fault by referring to 4.1.2 Alarms Related toLink Faults.

----End

4.2.9 Troubleshooting E1/T1 Transmission FaultsThis describes how to troubleshoot the faults in E1/T1 links and upper-level E1/T1 links.

Fault SymptomsOn the BSC6000 Local Maintenance Terminal, the query result shows that Port Status of theE1/T1 port is Fault. For details of how to browse the alarm information, refer to Querying theStatus of an Interface Board Port. The following alarms are reported:

l 20081 Loss of E1/T1 Signals (LOS)

l 20082 Loss of E1/T1 Frames (LOF)

l 20083 Remote E1/T1 Alarm (RAI)

l 20084 E1/T1 Alarm Indication Signal (AIS)

l 20085 Loss of E1/T1 Multiframes (LOM)

l 20086 E1/T1 Link Loopback

l 20087 High BER over the E1/T1 Link

l 20089 Excessive Loss of E1/T1 Signals in an Hour



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l 20090 Excessive E1/T1 Synchronization Failures in an Hour

l 20091 E1/T1 Excessive Peer End Alarms Per Hour

l 20092 E1/T1 Excessive Bit Error Rate Per Hour

l 20093 E1/T1 Excessive Slip Frames Per Hour

Possible CausesThe possible causes of the E1/T1 transmission faults are as follows:

l The DB44 connector of the E1/T1 cable is not securely connected to the panel of theinterface board.

l The transmission cable is wrongly connected.

l The E1/T1 port on the local device cannot receive signals normally.

l The E1/T1 port on the peer device cannot transmit signals normally.

l The line codes are inconsistent between lines.

l The subrack is not properly grounded.

l The shielding layer of the cable between the BSC and the transmission equipment isdamaged.

l The transmission line is faulty.

ProcedureRectify the faults according to the alarm-handling suggestions. If the faults persist, contact theHuawei Customer Service Center by referring to 1.3.1 Obtaining Technical Support.

----End

4.2.10 Troubleshooting Optical Transmission FaultsThis describes how to troubleshoot the optical transmission faults. The optical transmission isinterrupted and the upper links, such as OML, RSL, SS7 signaling link, PBSL, Ater signalinglink, and Ater OML are faulty at the same time.

Fault SymptomsOn the BSC6000 Local Maintenance Terminal, the query result shows that Port Status of theE1/T1 port is Fault. For details, refer to Querying the Status of an Interface Board Port. Thefollowing alarms are reported:

l 20222 Loss of Signals on the Optical Port (RLOS)

l 20223 Loss of Received Signal Frames on the Optical Port (RLOF)

l 20224 Out-of-Synchronization of Received Signal Frames on the Optical Port (ROOF)

l 20225 Mismatch of Trace Byte of the Regenerator Section on the Optical Port (RTIM)

l 20228 Multiplex Section Alarm Indication Signal (MAIS)

l 20227 Regenerator Section Signal Deteriorated (RSD)

l 20228 Multiplex Section Alarm Indication Signal (MAIS)

l 20229 Multiplex Section Remote Defect Indication (MRDI)




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l 20230 Loopback on the Optical Port

l 20231 Administration Unit Alarm Indication Signal (AUAIS)

l 20232 Loss of Administration Unit Pointer (AULOP)

l 20239 Loss of Tributary Unit Multi-frames (TULOM)

l 20240 Tributary Unit Alarm Indication Signal (TUAIS)

l 20241 Loss of Tributary Unit Pointer (TULOP)

l 20248 Loss of Tributary Signals (LOS)

l 20249 Tributary Alarm Indication Signal (AIS)

l 20250 Loss of Tributary Frames (LOF)

l 20251 Remote Alarm Indication over the Tributary (RAI)

l 20252 Loss of Tributary Multi-Frames (LOM)

l 20253 Slip Frame over the Tributary

l 20254 Tributary Loopback Alarm

l 20255 Optical Module Fault

Possible CausesThe possible causes of optical transmission faults are as follows:

l The optical cable is not connected properly.

l The transmission cable is wrongly connected.

l The optical port on the peer board is faulty.

l The optical port on the local board is faulty.

l The optical module is faulty.

l The transmission line is faulty.

ProcedureRectify the faults according to the alarm-handling suggestions. If the faults persist, contact theHuawei Customer Service Center by referring to 1.3.1 Obtaining Technical Support.

----End

4.2.11 Troubleshooting M3UA Link FaultsThis describes how to troubleshoot M3UA link faults. When all the M3UA links configured forthe BSC break down, all the MSs drop calls. When some of the M3UA links break down, theloads on others increase but the MSs do not drop calls.

Fault SymptomsThe M3UA link fault symptoms are as follows:

l On the BSC6000 Local Maintenance Terminal, check the status of SCCP connections.The result shows that the Destination signaling point state of an SCCP connection isProhibited. For details, refer to Maintaining the SCCP.



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l On the Local Maintenance Terminal, check the status of M3UA links. The result showsthat the Link State of an M3UA link is the non-activated or invalid state. For details, referto Display M3UA Link Status(DSP M3LNK).

l On the BSC6000 Local Maintenance Terminal, an alarm 701 M3UA Link Fault orpossibly 21525 SCCP DSP Unreachable and 704 M3UA Destination EntityUnvailably are reported. The ongoing services are disrupted.

Possible CausesThe possible causes of M3UA link faults are as follows:

l The links are manually disconnected or deactivated.

l The SCTP link configuration is inconsistent between the BSC and the MSC.

l The router to the BSC is wrongly configured.

Procedure

Step 1 Check whether the GXPUM, GXPUT, and GFGUA that carry the M3UA links are faulty byreferring to Querying BSC Board Information.l If faulty, check whether the board type is consistent with the data configuration and whether

the board is securely connected.l If not faulty, go to Step 2.

Step 2 Check whether the parameter configuration related to M3UA links is consistent between theBSC and the MSC.1. On the BSC6000 Local Maintenance Terminal, right-click the GFGUA board on the

BSC Device Panel tab page, and then choose Configure M3UA Link > Modify M3UALink.

2. A dialog box is displayed. Click Modify.3. Select the M3UA tab, as shown in Figure 4-8.




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Figure 4-8 Modify M3UA Link dialog box

Check whether the parameters such as Local Port No., Local Address 1, Local Address 2,Peer Port No., Peer Address 1, and Peer Address 2 on the BSC side are consistent with thoseon the MSC side.

l If inconsistent, delete the original parameter settings and reconfigure the parameters.


Step 3 Verify whether the SCTP check and algorithm on the BSC side are consistent with those on theMSC side.

Refer to Step 2. On the interface shown in Figure 4-8, select the SCTP tab page, as shown inFigure 4-9.



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Figure 4-9 Modify M3UA Link dialog box (2)

Check whether the parameters such as Receive Check Sum Validation Flag, Send Check SumValidation Flag, and Check Sum Type on the BSC side are consistent with those on the MSCside.

l If inconsistent, reconfigure the parameters to keep them consistent with those on the MSCside.


Step 4 On the Local Maintenance Terminal, run the PING IP command to ping the IP address of theremote MSC. Check whether the IP address can be pinged by referring to Ping Peer IP Address(PING IP).l If the IP address cannot be pinged, check whether the route from the BSC to the MSC is

normal. If the route is faulty, contact the Huawei Customer Service Center by referring to1.3.1 Obtaining Technical Support.

l If the IP address can be pinged, on the peer MSC side ping the device IP address of the localBSC. If the device IP address cannot be pinged, go to Step 5.

Step 5 Check the route configuration on the router connected to the BSC. Verify whether there is aroute to the GFGUA and ensure no redundant route configuration exists.l If there is no route to the GFGUA, add a valid route by referring to step 5 described in

Configuring the GFGUA/GOGUA.l If there is a route to the GFGUA and no redundant route configuration but the fault persists,

contact the Huawei Customer Service Center by referring to 1.3.1 Obtaining TechnicalSupport.

----End

4.2.12 Troubleshooting M3UA Route Unavailability FaultsThis describes how to troubleshoot the faults caused by M3UA route unavailability. The faultsymptom shows that the MSs incur call drops if all the M3UA routes from the BSC to the MSC




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are unavailable, or only the load on the available routes increases and the MSs incur no calldrops if some of the M3UA routes are unavailable.

Fault Symptoms

The fault symptoms of M3UA route unavailability are as follows:


l On the Local Maintenance Terminal, check the status of M3UA routes. The result showsthat the Access Flag of an M3UA route is Unaccessible. For details, refer to Display M3UARoute Status(DSP M3RT).

l On the BSC6000 Local Maintenance Terminal, an alarm 703 M3UA RouteUnvailable or possibly 21525 SCCP DSP Unreachable and 704 M3UA DestinationEntity Unvailably are reported. The ongoing services are disrupted.

Possible Causes

The possible causes of M3UA route unavailability are as follows:

l The M3UA link is faulty.

l If the BSC is connected to the MSC through the STP, the BSC may receive the signalingnetwork management message DUNA from the STP.

Procedure

Step 1 Check whether the M3UA link is faulty.

l If faulty, rectify the fault by referring to 4.2.11 Troubleshooting M3UA Link Faults.


Step 2 Check whether the BSC is connected to the MSC through an STP entity.

l If the BSC is connected to the MSC through an STP entity, check whether the link and theroute between STP and MSC is available.

l If the BSC is directly connected to the MSC with the link activated but the fault persists,contact the Huawei Customer Service Center by referring to 1.3.1 Obtaining TechnicalSupport.

----End

4.2.13 Troubleshooting M3UA Destination Entity InaccessibilityFaults

This describes how to troubleshoot the faults in the M3UA destination entity that is unavailable.The fault symptom shows that all the MSs incur call drops.

Fault Symptoms

The fault symptoms of M3UA destination entity inaccessibility are as follows:



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l On the Local Maintenance Terminal, check the status of M3UA destination entities. Theresult shows that the Access Flag of an M3UA destination entity is Unaccessible. Fordetails, refer to Display M3UA Destination Entity Status(DSP M3DE).

l On the BSC6000 Local Maintenance Terminal, view the alarm information. The alarms704 M3UA Destination Entity Unvailably, 21525 SCCP DSP Unreachable, and 701M3UA Link Fault are reported.

Possible CausesThe possible causes of M3UA destination entity inaccessibility are as follows:

l The M3UA link is faulty.

l The M3UA destination entity does not exist.

Procedure

Step 1 Check whether the M3UA link is faulty.l If faulty, rectify the fault by referring to 4.2.11 Troubleshooting M3UA Link Faults.


Step 2 Check whether the configuration data of the M3UA destination entity is correct.1. On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, right-

click BSC6000 and choose Configure M3UA Data > Configure M3UA Entity.2. Select the M3UA DE tab, as shown in Figure 4-10.

Figure 4-10 Configure M3UA Entity dialog box




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Check whether the DPC(Hex) on the BSC side is consistent with the DCP on the MSC side.

l If the DPC is inconsistent, delete the M3UA destination entity on the BSC side and thenreconfigure the parameter.

l If the DPC(Hex) is consistent, go to Step 3.

Step 3 Check whether the M3UA linkset is configured correctly.

On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, right-clickBSC6000 and choose Configure M3UA Linkset. A dialog box is displayed, as shown in Figure4-11.

Figure 4-11 Configure M3UA Linkset dialog box

Check whether the Adjacent DE Name on the BSC side is consistent with that on the MSCside.

l If the corresponding MSC does not exists, add a linkset to the destination entity that isadjacent to the MSC.

l If the corresponding MSC exists, go to Step 4.

Step 4 Check whether the M3UA route is configured correctly.

On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, right-clickBSC6000 and choose Configure M3UA Data > Configure M3UA Route. A dialog box isdisplayed, as shown in Figure 4-12.



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Figure 4-12 Configure M3UA Route dialog box

Check whether the DE Name on the BSC side correspond to the destination entity on the MSCside.

l If not existent, add a destination entity that corresponds to that on the MSC side.

l If existent, check whether the M3UA link is faulty. For details, see 4.2.11 TroubleshootingM3UA Link Faults.

----End

4.2.14 Troubleshooting Abis Interface IP Link FaultsThis describes how to troubleshoot the faults in the Abis interface IP link. When an Abis interfaceIP link is faulty, neither voice services nor data services can be provided for the MSs in thecoverage of the BTS.

Fault SymptomsOn the BSC6000 Local Maintenance Terminal, query the status of the LAPD link. The queryresult shows that the State of the OML/EML/RSL/ESL is Failure. For details, refer toMaintaining LAPD Links. An alarm 2114 LAPD Alarm is reported. Multiple cells are out ofservice and neither voice services nor data services can be provided for the MSs in the coverageof the BTS.

NOTE

After the Abis interface uses the IP link, the BTS communicates with the BSC through the IP network.Therefore, if the IP link is functional, the IP bearer layer works normally.

Possible CausesThe possible causes of Abis interface IP link faults are as follows:




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l The data configuration is inconsistent.

l The hardware is wrongly installed or cabled.

l The BSC route configuration is incorrect.

Procedure

Step 1 On the Local Maintenance Terminal, ping the IP address of the BTS port. For details, refer toPinging the Peer-End IP Address.l If you ping the IP address successfully, you can infer that the BTS has obtained the IP

address; but if the OML is inaccessible, you can infer that the BTS fails to set up the linkcorrectly. Then, go to Step 2.

l If you cannot ping the IP address, the BTS may have not obtained the IP address throughthe DHCP. Check whether the ports interconnecting the BTS and the BSC are configuredconsistently with the data configuration and whether the electronic labels of the BTS areconsistent with the data configuration. If inconsistent, reconfigure the ports or the electroniclabels. For details, refer to Configuring Abis over IP. If consistent, go to Step 3.

Step 2 Check whether the TRAN wiring terminal is plugged out from the interface board.l If the TRAN wiring terminal is still connected to the interface board, plug it out to reduce

its interference to the IP communication.l If the TRAN wiring terminal is plugged out, go to Step 3.

Step 3 Check whether the DPTU board is inserted in a correct slot. The correct location is slot 3 or 4of subrack 0.l If the board is inserted in a wrong slot, reinsert the board in the correct location as mentioned

previously.l If the board is inserted in a correct slot, go to Step 4.

Step 4 Check whether the route from the BSC to the BTS is configured incorrectly.

l If the route configuration is incorrect, reconfigure the route as follows:– For layer 2 networking, the destination IP address is the logical IP address of the BTS,

and the gateway IP address is the port IP address of the BTS.– For layer 3 networking, configure the following two routes:

– One destination IP address is the logical IP address of the BTS, and the gateway IPaddress is the IP address of the port connecting the router and the GFGUB.

– One destination IP address is the DHCP Relay IP address of the BSC, and thegateway IP address is the IP address of the port connecting the router and theGFGUB.

For details, refer to Configuring Abis over IP.l If the route configuration is correct but the fault persists, contact the Huawei Customer

Service Center by referring to 1.3.1 Obtaining Technical Support.

----End

4.3 Typical Cases of Troubleshooting Link FaultsThis describes the typical cases of troubleshooting link faults.



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4.3.1 Case: BTS TRX FaultsThis describes a case of troubleshooting BTS TRX faults. Due to the TRX faults, the TRX boardcannot upload data normally, and therefore the configured TRX should be kept consistent withthe actual TRX type.

4.3.2 Case: BTS FaultsThis describes a typical case of troubleshooting BTS faults. Due to the BTS faults, all the boardsof the BTS cannot upload data normally, and therefore the configured BTS type should be keptconsistent with the actual BTS type.

4.3.3 Case: BTS Loading FailureThis describes a typical case of troubleshooting the BTS loading failure. The symptom is thatwhen the 120-ohm trunk cable is used to connect the BTS and the BSC, they cannot communicatenormally. The DIP switches of the BSC6000 interface board and the BTS DTMU must beadjusted.

4.3.4 Case: Abis Transmission FaultsThis describes a typical case of troubleshooting Abis transmission faults. If the Abis transmissionis faulty, the LIUx LEDs of the BTS blink irregularly. You should prevent both ends of the E1cable from being grounded.

4.3.5 Case: M3UA Link FaultsThis describes a typical case of troubleshooting M3UA link faults. The link connection betweenBSC and MSC is also associated with the configuration of routers. You need not configureredundant route data for the routers if unnecessary.

4.3.1 Case: BTS TRX FaultsThis describes a case of troubleshooting BTS TRX faults. Due to the TRX faults, the TRX boardcannot upload data normally, and therefore the configured TRX should be kept consistent withthe actual TRX type.

Fault Symptoms

The inconsistency between configured TRX and actually used TRX results in the failure of theTRX board to upload data. Thus, a fault occurs in the RSL.

Fault Location and Rectification

Delete the TRX and reconfigure the TRX data. For details, refer to Modifying TRXAssignment.

4.3.2 Case: BTS FaultsThis describes a typical case of troubleshooting BTS faults. Due to the BTS faults, all the boardsof the BTS cannot upload data normally, and therefore the configured BTS type should be keptconsistent with the actual BTS type.

Fault Symptoms

The inconsistency between configured BTS type and actual BTS type results in the failure ofthe BTS boards to upload data. Thus, a fault occurs in the OML.




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Fault Location and RectificationDelete the BTS and reconfigure the BTS data. For details, refer to Configuring the BTS.

4.3.3 Case: BTS Loading FailureThis describes a typical case of troubleshooting the BTS loading failure. The symptom is thatwhen the 120-ohm trunk cable is used to connect the BTS and the BSC, they cannot communicatenormally. The DIP switches of the BSC6000 interface board and the BTS DTMU must beadjusted.

Fault SymptomsIf the DIP switches of the BSC6000 interface board and the BTS DTMU are not correctly setwhen the 120-ohm trunk cable is used for transmission, both ends of the cable may be groundedand thus form a loop. This follows a burst of bit errors, which disables the communicationbetween the BTS and the BSC. As a result, the BTS cannot be initialized.

Fault Location and Rectificationl Set the DIP switches S1, S3, S4, S5, and S6 of the BSC GEIUB to OFF.

l Set the SW6 and SW7 of the BTS DCSU to OFF. For details, refer to DIP Switches onthe DCSU.

l Set the S4, S5, S6, and S7 of the BTS DTMU to OFF. For details, refer to DIP Switcheson the DTMU.

4.3.4 Case: Abis Transmission FaultsThis describes a typical case of troubleshooting Abis transmission faults. If the Abis transmissionis faulty, the LIUx LEDs of the BTS blink irregularly. You should prevent both ends of the E1cable from being grounded.

Fault SymptomsThe 120-ohm twisted pair cable is used for the Abis transmission of a BTS and the signals aretransmitted through the DDF. After a loopback is performed on the DDF, the LIUx LEDs of theBTS are off. The analysis shows that the Abis transmission is normal but bit errors may occuron the Abis interface. The causes of bit errors are as follows:

l The connectors of the 120-ohm twisted pair cable are in poor contact.

l The connectors of the 120-ohm twisted pair cable are polluted.

l The 120-ohm twisted pair cable has wires exposed, which leads to strong signalinterference.

l Both ends of the shielding layer of the E1 cable between the BTS DTMU, DDF, andBSC6000 GEIUB are grounded.

The previous analysis shows that both ends of the shielding layer of the E1 cable between theBTS DTMU and the DDF are grounded and a loop is formed, which leads to bit errors. Thecauses of bit errors are as follows:

l The signals are transmitted between the GEIUB, GEIUP, and GEIUT of the BSC throughthe 120-ohm twisted pair cable in balanced mode. If the DIP switch for the transmitting



4-39

end is set to OFF, the cable is not grounded automatically. If the DDF is grounded only,then no loop is formed, and thus the signal quality at the BSC transmitting end is good.

l The DIP switch on the BTS3012 DTMU is used to control the grounding of the E1 cablejacket at the transmitting end, and the DIP switch on the DCSU is used for controllingdifferent transmission cables instead of grounding only the E1 cable jacket at thetransmitting end. The DIP switches S4, S5, S6, and S7 on the DTMU are set to ON beforedelivery. Such settings form a loop between DTMU and DDF and lead to bit errors.

Fault Location and Rectification1. On the BSC6000 Local Maintenance Terminal, check the status of the E1 port. The Abis

interconnection, however, introduces the following problems:l The LIUx LEDs of the BTS blink irregularly.

l On the BSC6000 Local Maintenance Terminal, trace the Abis OML messages. TheBTS reports UI frames occasionally. For details, refer to Tracing OML Messages onthe Abis Interface.

l The BTS local and remote alarms are reported on the site maintenance terminal, andthe related alarms are cleared.

l On the BSC6000 Local Maintenance Terminal, view the alarm information, and youcan find that the 1000 LAPD OML Fault alarm is reported and the LAPD link is broken.

l Use the DDF connector probe to check the transmit and receive signal strength. Theresult shows that the BSC transmit signal is strong and the BTS transmit signal is weak.

2. Check the E1 cable connection and prevent both ends of the E1 cable from being grounded.

4.3.5 Case: M3UA Link FaultsThis describes a typical case of troubleshooting M3UA link faults. The link connection betweenBSC and MSC is also associated with the configuration of routers. You need not configureredundant route data for the routers if unnecessary.

Fault Symptoms

The reset of the BSC GFGUA causes the SCTP link to break down. After the Ethernet cable isreconnected, the SCTP link works normally.

Fault Location and Rectification1. Verify the check and algorithm configuration of the SCTP link of the BSC and MSC. The

CRC32 check is not enabled. For details of the BSC side, refer to Step 3 described in 4.2.11Troubleshooting M3UA Link Faults.The SCTP link check and algorithm are correctly configured because the SCTP link worksnormally after the Ethernet cable is reconnected. Therefore, the data configuration betweenBSC and MSC is considered to be consistent.

2. Check the IP address of the SCTP and the port number on both BSC and MSC sides andensure that there is no data inconsistency between them. For details of the data configurationon the BSC side, refer to Configuring the GFGUA/GOGUA.After the Ethernet cable is reconnected, the SCTP link recovers. You can infer that the dataconfiguration between the two sides is consistent. Therefore, the problem is not caused bydata inconsistency.




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3. According to the previous analysis, you can decide that the fault is related to the routerconfiguration. Perform the following operations for further analysis:

(1) Trace the SCTP of the A interface on the BSC side. You can find that only the uplinkmessage to the MSC instead of the MSC downlink message to the BSC is traced. Fordetails, refer to Tracing SCTP Messages on the A Interface.

(2) Trace the SCTP of the A interface on the MSC side. The MSC can receive the SCTPmessage from the BSC and the MSC responds to the message.

(3) The port of the MSC connected to the router catches IP packets. The port can catchthe messages sent from or received by the MSC.

Based on the analysis, you can determine that the messages are discarded in the router andyou need to check the router configuration.

4. Check the router configuration. Figure 4-13 shows the routes between the BSC and theMSC.

Figure 4-13 Router configuration

GFGUA

BSC Router MSC

1

5

Two routes are configured from the MSC to the BSC: one is to port 1 of the GFGUA, andthe other is to port 5 of the GFGUA. When port 1 is enabled and port 5 is disabled, thephysical connection between the routers still exists. That is, two MSC-to-BSC routes existon the router. One is available and the other is unavailable.Because the router determines the availability of a route according to physical connections,the router identifies the route to port 5 as available. When the IP packets from the MSC tothe BSC are transferred at the router, the router may forward the IP packets to an unavailableport 5.To sum up, the messages sent by the BSC can reach the MSC, but the messages returnedby the MSC cannot reach the BSC.

5. Delete the redundant routes in the router, that is, physically disconnect the router from port5.



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5 Clock Faults

About This Chapter

This describes clock faults in terms of the symptoms, troubleshooting methods, and typical cases.

5.1 Clock Fault SymptomsThis describes the impacts of clock faults on services, possible alarms, and involved performancecounters.

5.2 Clock Troubleshooting MethodsThis describes how to troubleshoot clock faults. Basically, when a clock fault occurs, first dealwith the reported alarm, then determine the subclass of the fault, and finally rectify the fault.

5.3 Typical Cases of Troubleshooting Clock FaultsThis describes the typical cases of troubleshooting clock faults.

HUAWEI BSC6000 Base Station SubsystemBSS Troubleshooting Guide 5 Clock Faults


5-1

5.1 Clock Fault SymptomsThis describes the impacts of clock faults on services, possible alarms, and involved performancecounters.

5.1.1 Impacts of Clock Faults on ServicesThis describes the impacts of clock faults on services.

5.1.2 Alarms Related to Clock FaultsThis describes the BSS alarms related to clock faults. The alarms help locate and rectify thefaults.

5.1.3 Counters Related to Clock FaultsCurrently there are no counters related to clock faults.

5.1.1 Impacts of Clock Faults on ServicesThis describes the impacts of clock faults on services.

The impacts of clock faults on services are as follows:

l The MS drops the call.

l The signaling link is disconnected intermittently.

5.1.2 Alarms Related to Clock FaultsThis describes the BSS alarms related to clock faults. The alarms help locate and rectify thefaults.

Alarms related to BSC clock faults

Table 5-1 lists the alarms related to BSC clock faults.

Table 5-1 Alarms related to BSC clock faults


BSC clock faults 20003 Board Fault - Faulty Inner Clock

20005 Faulty Clock Source 0 from the FrontInterface Board to the Backplane of theGSCU

20006 Faulty Clock Source 1 from the FrontInterface Board to the Backplane of theGSCU

20007 Faulty Clock Source 0 from the RearInterface Board to the Backplane of theGSCU

5 Clock FaultsHUAWEI BSC6000 Base Station Subsystem



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20008 Faulty Clock Source 1 from the RearInterface Board to the Backplane of theGSCU

20009 Faulty 8 kHz Clock Source from theActive GGCU to the Backplane of the GSCU

20010 Faulty 8 kHz Clock Source from theStandby GGCU to the Backplane of theGSCU

20013 Faulty GGCU 8 kHz Clock Source forthe Front Panel of the GSCU

20016 Faulty 32 MHz Clock from theBackplane

20026 Faulty Phase-Locked Loop of theBoard Clock

20039 Faulty Output Clock Signals

20044 Unavailable Clock Source

20221 Loss of Clock on the Optical Port(RLOC)

20321 Unavailable Clock Reference forGGCU

20322 Unavailable Current Clock Referencefor GGCU

20323 GGCU Failure-Abnormal FrequencyDoubler

20324 GGCU Failure-Abnormal LocalOscillation Signal

20325 Clock Reference Failure of GGCU over24 Hours

20329 Unavailable Input Clock Source forGGCU

Alarms related to BTS clock faultsTable 5-2 lists the alarms related to BTS clock faults.



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Table 5-2 Alarms related to BTS clock faults


BTS3X clock fault 2166 TRX Main Clock Alarm

2168 TRX Slave Clock Alarm

2196 TRX Clock Critical Alarm

2208 Clock Reference abnormal Alarm

2232 Master TMU Clock Failure Alarm

2234 Master TMU Clock Alarm

2236 Extended TMU Clock Alarm

2260 13M Clock Maintenance Alarm

2574 PBU Main Clock Alarm

2576 PBU Slave Clock Alarm

2578 PBU Clock Critical Alarm

BTS3001C clock fault 3134 MFU Clock Critical alarm

3146 Clock Reference Abnormal alarm

3172 MMU Clock alarm

3438 Clock alarm

BTS3002C clock fault 3654 DRU Clock Critical alarm

3666 Clock Reference Abnormal alarm

3692 IOMU Clock Alarm

3718 13M Clock Maintenance Alarm

3800 IASU Cock Source Lost alarm

3802 IASU Crystal Oscillator Alarm

Double-transceiver BTS clock fault 4120 DBUS Clock alarm

4154 TRX main clock alarm

4156 TRX slave clock alarm

4184 TRX clock critical alarm

4708 Clock Reference Abnormal Alarm

4732 TMU clock critical alarm

4734 Master TMU clock alarm

4736 Extended TMU clock alarm




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4760 13M Maintenance Alarm

4772 Master Clock Alarm

4804 Slave DTMU TDMA CLK Alarm

5320 DUP Unit Clock Abnormal

9682 PBU Main Clock Alarm

9684 PBU Slave Clock Alarm

9686 PBU Clock Critical Alarm

5.1.3 Counters Related to Clock FaultsCurrently there are no counters related to clock faults.

5.2 Clock Troubleshooting MethodsThis describes how to troubleshoot clock faults. Basically, when a clock fault occurs, first dealwith the reported alarm, then determine the subclass of the fault, and finally rectify the fault.

ProcedureStep 1 Deal with the reported alarm according to the alarm help.


Table 5-3 Clock troubleshooting methods


On the BSC6000 Local MaintenanceTerminal, find that the PLL state is notLocked.

5.2.1 Troubleshooting Clock Source Faults

On the BSC6000 Local MaintenanceTerminal, find that a clock sourceprovided by a board is in an abnormal state.

5.2.2 Troubleshooting Board Clock Faults


----End

5.2.1 Troubleshooting Clock Source FaultsThis describes how to troubleshoot clock source faults.



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Fault SymptomsThe PLL state is not Locked, which you can check on the BSC6000 Local MaintenanceTerminal by referring to Maintaining the BSC Clock Reference Status. An alarm 20010Faulty 8 kHz Clock Source from the Standby GGCU to the Backplane of the GSCU or20009 Faulty 8 kHz Clock Source from the Active GGCU to the Backplane of the GSCUis reported.

Possible CausesThe possible causes of clock source faults are as follows:

l The active GGCU fails to lock the upper-layer clock source and provide the timing signalsto the GSCU.

l The active GGCU is faulty.

l The standby GSCU is faulty.

l The backplane is faulty.

Procedure

Step 1 By referring to Maintaining the BSC Clock Reference Status, check whether the standbyGGCU locks the upper-layer clock source.l If the standby GGCU locks the upper-layer clock source, go to Step 2.l If the standby GGCU fails to lock the upper-layer clock source, go to Step 3.

Step 2 Check whether the alarm is cleared.l If the alarm is cleared, end the troubleshooting.l If the alarm is not cleared, go to Step 3.

Step 3 Check whether both the active and the standby GSCUs report this alarm.l If both the active and the standby GSCUs report this alarm, go to Step 4.l If only one GSCU reports this alarm, go to Step 6.

Step 4 Secure the standby GGCU and then check whether the alarm is cleared.l If the alarm is cleared, end the troubleshooting.l If the alarm is not cleared, go to Step 5.

Step 5 Replace the standby GGCU and then check whether the alarm is cleared after the board issuccessfully restarted.l If the alarm is cleared, end the troubleshooting.l If the alarm is not cleared, go to Step 6.

Step 6 Secure the GSCU and then check whether the alarm is cleared.l If the alarm is cleared, end the troubleshooting.l If the alarm is not cleared, go to Step 7.

Step 7 Check whether the board reporting the alarm is active.l If the board is active, go to Step 8.l If the board is standby, go to Step 9.




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Step 8 Switch over the active and standby boards, and then check whether the alarm is cleared after theoriginally standby board is successfully restarted.l If the alarm is cleared, end the troubleshooting.l If the alarm is not cleared, go to Step 9.

Step 9 Replace the standby GSCU and then check whether the alarm is cleared after the board issuccessfully restarted.l If the alarm is cleared, end the troubleshooting.l If the alarm is not cleared, contact the Huawei Customer Service Center by referring to

1.3.1 Obtaining Technical Support.

----End

5.2.2 Troubleshooting Board Clock FaultsThis describes how to troubleshoot board clock faults.

Fault SymptomsA clock source provided by a board is in an abnormal state, which you can check on the BSC6000Local Maintenance Terminal by referring to Maintaining the BSC Clock ReferenceStatus. An alarm 20003 Board Fault - Faulty Inner Clock is reported.

Possible CausesThe possible cause of a board clock fault is that the board hardware is faulty.

ProcedureReplace the faulty board and then check whether the alarm is cleared after the board issuccessfully restarted.l If the alarm is cleared, end the troubleshooting.l If the alarm is not cleared, contact the Huawei Customer Service Center by referring to

1.3.1 Obtaining Technical Support.

----End

5.3 Typical Cases of Troubleshooting Clock FaultsThis describes the typical cases of troubleshooting clock faults.

5.3.1 Case: All BTS Clock Reference Sources UnavailableThis describes a typical case of troubleshooting the faults occuring when all BTS clock referencesources of the BSC are unavailable. If the BSC clock reference source is not BITS Clock, allBTS clock reference sources are unavailable.

5.3.2 Case: Slip Frame AlarmThis describes a typical case of handling the slip frame alarm. If the BSC clock is configuredincorrectly or the transmission equipment/cable is faulty, the slip frame alarm is generated. Youmust check the BSC clock configuration and the transmission equipment/cable.

5.3.3 Case: Phase-Locked Loop in Non-Locked State



5-7

This describes a typical case of troubleshooting the faults in the phrase-lock loop that is in non-locked state. when the faults occur, you can infer that the clock reference source of the GGCUis faulty.

5.3.4 Case: Handover Call Drop Due to Large Frequency Offset of BTS ClockThis describes how to troubleshoot the handover call drop fault caused by the unstable BTSclock. You need to keep the BTS clock stable.

5.3.1 Case: All BTS Clock Reference Sources UnavailableThis describes a typical case of troubleshooting the faults occuring when all BTS clock referencesources of the BSC are unavailable. If the BSC clock reference source is not BITS Clock, allBTS clock reference sources are unavailable.

Fault Symptoms

When the networking mode is BTS - BSC (BM) - trunk transmission - BSC (TC) - MSC, allBTSs of the BSC report the alarm warning that the clock reference source is faulty. Other networkperformances are listed as follows:

l The BSC traces the line clock, and the BSC reports no related alarms.

l The transmission on the Ater interface is normal.

l Other BSCs under the same MSC report no related alarms.

The MSC and BSC report no clock reference source alarms, and you can infer that the clockfrequency offset is within a normal range.

The BTS clock frequency offset ranges from -0.15 ppm to +0.15 ppm (a millionth), and the BSCclock frequency offset ranges from -4.6 ppm to +4.6 ppm. If the MSC clock frequency offset islarger than ±0.15 ppm and smaller than ±4.6 ppm (in theory), the BTS reports the clock referencesource abnormal alarm and the BSC reports no related alarms.

Fault Location and Rectification

Modify the clock configuration on the BSC6000 Local Maintenance Terminal. Set the SourceType to BITS0. For details, refer to Configuring the System Clock.

5.3.2 Case: Slip Frame AlarmThis describes a typical case of handling the slip frame alarm. If the BSC clock is configuredincorrectly or the transmission equipment/cable is faulty, the slip frame alarm is generated. Youmust check the BSC clock configuration and the transmission equipment/cable.

Fault Symptoms

Currently, the BSC slip frame alarm is of two types:

l 20093 E1/T1 Excessive Slip Frames Per Hour

l 20253 Slip Frame over the Tributary

If the BSC clock is asynchronous with the MSC clock and the difference between them reachesa frame, one frame signal is discarded or repeated. Therefore, when the slip frame alarm isreported, you must check the configuration and state of the clock on both BSC and MSC sides.




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Fault Location and Rectification1. Check whether the BSC clock is configured incorrectly, if the alarm 20253 Slip Frame

over the Tributary is reported.l If the BSC clock is configured incorrectly, go to 2.

l If the BSC clock is configured correctly, go to 3.

2. Based on the configurations of system clock, GMPS line clock, and GTCS line clock,configure the BSC clock correctly. For details, refer to Configuring the System Clock,Configuring the Line Clock for the GMPS, and Configuring the Line Clock for theGTCS.l If the alarms are cleared, end the task.

l If the alarms are still reported, go to 3.

3. Contact the transmission engineer to check whether the transmission equipment or cableis normal.l If the transmission cable is normal, contact the Huawei Customer Service Center by

referring to 1.3.1 Obtaining Technical Support.l If the transmission cable is faulty, contact the transmission engineer to solve the problem

until the alarms are cleared.

5.3.3 Case: Phase-Locked Loop in Non-Locked StateThis describes a typical case of troubleshooting the faults in the phrase-lock loop that is in non-locked state. when the faults occur, you can infer that the clock reference source of the GGCUis faulty.

Fault SymptomsOn the BSC6000 Local Maintenance Terminal, query the status of the BSC clock referencesource. The PLL state is Free running, and the Work mode is Automatic. For details, refer toMaintaining the BSC Clock Reference Status. Figure 5-1 shows the dialog box.



5-9

Figure 5-1 Query BSC Clock Reference State dialog box

Fault Location and RectificationThe non-locked state of the phrase-locked loop of the GGCU is categorized into Free running,Fast tracking, and Hold over. Normally, the phrase-locked loop of the GGCU is in locked state.If the phrase-locked loop of the GGCU is in non-locked state, the clock reference source of theGGCU is faulty.

l When the phrase-locked loop of the GGCU is in Free running state, you can infer that theclock reference source is unavailable. You must check the configuration of the clockreference source of the GGCU.– If the clock reference source type is line 0 or line 1, view the alarm information on the

BSC6000 Local Maintenance Terminal, and check whether the GEIUA/GOIUAwhere the line clock is located reports alarms. If alarms are reported, handle the alarmsby referring to BSS Alarm Reference.

– If the clock reference source type is BITS0, view the alarm information on the BSC6000Local Maintenance Terminal, and check whether there are alarms related to the clockreference source. If alarms are reported, handle the alarms by referring to BSS HelpSystem.




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l When the phrase-locked loop of the GGCU is in Fast tracking state, this state is temporarybut will not last long.

l When the phrase-locked loop of the GGCU is in Hold over state, you can infer that thecurrent clock reference source is unavailable. On the BSC6000 Local MaintenanceTerminal, view the alarm information and check whether the alarms related to the clockreference source are reported. If alarms are reported, handle the alarms by referring to BSSAlarm Reference.

5.3.4 Case: Handover Call Drop Due to Large Frequency Offset ofBTS Clock

This describes how to troubleshoot the handover call drop fault caused by the unstable BTSclock. You need to keep the BTS clock stable.

Fault SymptomsCall drops occasionally occur when the handover is performed at the DCS1800M frequencyband. However, the signal level is normal without interference.

Fault Location and Rectification1. The BTS frequency offset remain large. The 13 MHz output frequency offset of some BTSs

reaches 2.5 Hz. This exceeds the national standard, 0.65 Hz.2. The system reports many BTS 8 kHz clock alarms, and the MSC reports 3598 Phase-Lock

Loop alarm frequently. You can infer that the MSC clock is unstable and that the call dropis mainly caused by the unstable BTS clock.

3. The MSC clock reference source is adjusted on the MSC side. The BTS clock becomesstable and the BTS 8 kHz clock alarms are cleared. The handover call drop disappears.



5-11

6 Handover Faults

About This Chapter

This describes handover faults in terms of the symptoms, troubleshooting methods, and typicalcases.

6.1 Handover Fault SymptomsThis describes the impacts of handover faults on services, possible alarms, and involvedperformance counters.

6.2 Handover Troubleshooting MethodsThis describes how to troubleshoot handover problems. Basically, when a handover problemoccurs, first deal with the reported alarm, then determine the subclass of the fault, and finallyrectify the fault.

HUAWEI BSC6000 Base Station SubsystemBSS Troubleshooting Guide 6 Handover Faults


6-1

6.1 Handover Fault SymptomsThis describes the impacts of handover faults on services, possible alarms, and involvedperformance counters.

6.1.1 Impacts of Handover Faults on ServicesThis describes the impacts of handover faults on services. When a handover fault occurs, thevoice quality deteriorates or the handover success rate decreases obviously.

6.1.2 Alarms Related to Handover FaultsThis describes the alarms related to handover faults. The alarms help locate and rectify the faults.

6.1.3 Counters Related to Handover FaultsThis describes the counters related to handover faults. The counters help locate and rectify thefaults.

6.1.1 Impacts of Handover Faults on ServicesThis describes the impacts of handover faults on services. When a handover fault occurs, thevoice quality deteriorates or the handover success rate decreases obviously.

The types of handovers originated by the MS are as follows:

l Edge handover

l Bad quality handover

l Rapid level drop handover

l Power budget (PBGT) handover

l Interference handover

If the handover fails, the voice quality is deteriorated or the call is dropped. Moreover, thehandover success rate decreases obviously.

6.1.2 Alarms Related to Handover FaultsThis describes the alarms related to handover faults. The alarms help locate and rectify the faults.

The BSC clock alarm, BTS clock alarm, TRX fault alarm, CDU fault alarm, and antenna faultalarm are related to handover.

When the clock alarm is generated, the BTS service still provides services but greatly affectsthe handover. For clock alarms, refer to 5.1.2 Alarms Related to Clock Faults.

6.1.3 Counters Related to Handover FaultsThis describes the counters related to handover faults. The counters help locate and rectify thefaults.

Table 6-1 lists the counters related to handover faults.

6 Handover FaultsHUAWEI BSC6000 Base Station Subsystem



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Table 6-1 Counters related to handover faults

Counter Description

ZK3180 Handover Success Ratio per BSC

ZK3181 Intra-BSC Handover Success Rate



ZK3176 Inter-BSC Outgoing Cell Handover Success Rate




CH302A Failed Internal Intra-Cell Handovers (ChannelUnavailable)

CH302C Failed Internal Intra-Cell Handovers (TimerExpired)

CH302D Failed Internal Intra-Cell Handovers(Reconnection to Old Channels)

H3022A Failed Internal Intra-Cell Handovers (Underlayto Overlay)

H3021A Failed Internal Intra-Cell Handovers (Overlay toUnderlay)

H3022M Failed Internal Intra-Cell Handovers (OtherCauses) (Overlay to Underlay)

H3021M Failed Internal Intra-Cell Handovers (OtherCauses) (Overlay to Underlay)

H322B Failed Incoming Internal Inter-Cell Handovers(Terrestrial Resource Request Failed)

H322D Failed Incoming Internal Inter-Cell Handovers(Reconnection to Old Channels)

H322G Failed Incoming Internal Inter-Cell Handovers(A Interface Failure)

H3220A Failed Internal Intra-Cell Handovers (NoChannel Available) (SDCCH)]

H3229A Failed Internal Intra-Cell Handovers (NoChannel Available) (TCH)]

CH322C Failed Internal Intra-Cell Handovers (TimerExpiry)



6-3

Counter Description

H312A Failed Outgoing Internal Inter-Cell Handovers(No Channel Available)

H312B Failed Outgoing Internal Inter-Cell Handovers(Terrestrial Resource Request Failed)

H312G Failed Outgoing Internal Inter-Cell Handovers(A Interface Failure)

CH312C Failed Outgoing Internal Intra-Cell Handovers(Timer Expiry)

CH312D Failed Outgoing Internal Inter-Cell Handovers(Reconnection to Old Channels)

H342I Failed Incoming External Inter-Cell Handovers(Invalid Message)

H3420A Failed External Intra-Cell Handovers (NoChannel Available) (SDCCH)]

H3429A Failed External Intra-Cell Handovers (NoChannel Available) (TCH)]

H342E Failed Incoming External Inter-Cell Handovers(CIC Unavailable)

H342F Failed Incoming External Inter-Cell Handovers(CIC Allocated)

H342B Failed Incoming External Inter-Cell Handovers(Terrestrial Resource Request Failed)

H342H Failed Incoming External Inter-Cell Handovers(Clear Commands Sent By MSC)

CH342C Failed Incoming External Inter-Cell Handovers(Timer Expired)

CH332K Failed Outgoing External Inter-Cell Handovers(Handover Request Rejected)

CH332D Failed Outgoing External Inter-Cell Handovers(Reconnection to Old Channels)

CH332H Failed Outgoing External Inter-Cell Handovers(Clear Commands Sent By MSC)

CH332L Failed Outgoing External Inter-Cell Handovers(T7 Expired)

CH332C Failed Outgoing External Inter-Cell Handovers(T8 Expired)




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6.2 Handover Troubleshooting MethodsThis describes how to troubleshoot handover problems. Basically, when a handover problemoccurs, first deal with the reported alarm, then determine the subclass of the fault, and finallyrectify the fault.

Procedure



Table 6-2 Handover troubleshooting methods


The MS does not originate a handoverwhen it should do or originates handoversfrequently.

6.2.1 Troubleshooting No or Too ManyHandovers Originated by the MS

A handover fails because the target cell iscongested.

6.2.2 Troubleshooting Destination CellCongestion Faults

A cell to which no handover can beperformed reports a BTS fault alarm.

6.2.3 Troubleshooting Hardware Faults

No handover between BSCs or MSCs cansucceed.

6.2.4 Troubleshooting Inter-BSC or Inter-MSC Handover Failures

A handover of any other type fails. 6.2.5 Troubleshooting Other HandoverFaults


----End

6.2.1 Troubleshooting No or Too Many Handovers Originated bythe MS

This describes how to troubleshoot a problem of no handover originated or too many handoversoriginated by the MS.

Possible CausesThe possible causes of no handover originated or too many handovers originated are as follows:

l If the handover threshold is too high, few handovers can be originated. If it is too low, toomany handovers are originated frequently.

l If a neighboring cell is not configured, the MS cannot originate a handover to this cell.



6-5

l If the handover hysteresis is too large, few handovers can be originated. If it is too small,too many handovers are originated frequently.

l If the N or P value is too large, few handovers can be originated. If it is too small, thehandover target cell may not be the best one.

Procedure

Step 1 If the handover threshold is improper, adjust it.

Step 2 If a neighboring cell is not configured, add it.

Step 3 If the handover hysteresis is improper, adjust it.

Step 4 If the N or P values is improper, adjust it.

NOTE

For detailed operations, refer to Configuring the Handover.

----End

6.2.2 Troubleshooting Destination Cell Congestion FaultsThis describes how to troubleshoot destination cell congestion faults. When the destination cellis congested, the MS cannot obtain the channel resource after requesting a handover.

Possible Causes

The possible causes of destination cell congestion are as follows:

l The number of MSs suddenly increases, exceeding the designed number.

l Improper parameter settings during network optimization lead to admission of too manyMSs to the cell.

l Improper handover parameter settings lead to admission of too many MSs to the cell.

Procedure

Step 1 If a TRX or channel fault occurs, rectify such a fault first.

Step 2 If the cell does not allow the conversion from full-rate channels to half-rate channels, set TCHRate Adjust Allow of each TRX of this cell to Yes on the BSC6000 Local MaintenanceTerminal by referring to Modifying Channel Attributes (Full Rate and Half Rate).Alternatively, expand the capacity of the cell.

----End

6.2.3 Troubleshooting Hardware FaultsThis describes how to troubleshoot hardware faults. When a hardware fault occurs, an alarm isreported.

Possible Causes

The possible causes of hardware faults are as follows:




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l The BTS transmission management unit (TMU) is faulty.

l The BTS TRX is faulty.

l The BTS CDU is faulty.

l The BTS feeder is faulty.

Procedure

Step 1 If the configuration data of the failed cell and its neighboring cells is not modified recently, youcan infer that the BTS hardware is faulty.l If the handover problem occurs in only one cell under this BTS, you can infer that a TRX

of the cell is faulty, which leads to a failure in handover to this TRX.l If the handover problem occurs also in the neighboring cells on the same site, you can infer

that the hardware, such as the TMU, shared by the cells is faulty.For the above problems, you can check them by blocking some TRXs. If the handover successrate is within the allowed range after blocking a TRX, check whether this TRX is faulty orwhether the related CDU or feeder is faulty.

NOTE

If UL signals and DL signals on a TRX are very unbalanced, then handover problems, such as frequenthandovers or decreases in the handover success rate, may often occur.

Step 2 Trace the Abis interface to check whether the signaling related to this cell is normal, includingwhether the UL and DL RX qualities are good. For detailed operations, refer to Tracing theMessages on the Abis Interface.

If the measurement report shows that the TCHH Receive Level Measurement or TCHFReceive Level Measurement is poor, you can infer that the hardware of this cell is faulty orthere is severe interference to this cell. Thus, signaling messages cannot be exchanged properlyand the handover cannot be performed successfully. For detailed operations, refer to 7.2.4Troubleshooting Interference Problems.

----End

6.2.4 Troubleshooting Inter-BSC or Inter-MSC Handover FailuresThis describes how to troubleshoot Inter-BSC or inter-MSC handover failures.

Possible CausesThe possible causes of inter-BSC and inter-MSC handover failures are as follows:

l The data configuration of the cells involved in inter-MSC handover is incorrect.

l The configuration data of the target cell for inter-BSC handover is incorrect.

l The MSC and the BSC process signaling messages on the A interface in different ways,and therefore they fail to cooperate with each other.

l Clocks of the two BSCs are out of synchronization.

Procedure

Step 1 On the MSC side, check whether the configuration data, such as the CGI and owner, of theinvolved cells is correct.



6-7

l If incorrect, modify it.l If correct, go to Step 2.

Step 2 Check whether the neighboring cells are configured properly on the source BSC side and thetarget BSC side.l If incorrect, modify it by referring to Configuring the Handover.l If correct, go to Step 3.

Step 3 Trace the signaling on the A interface by referring to Tracing the Messages on the AInterface.

Check whether the signaling procedure between the source BSC and the MSC works well withthat between the MSC and the target BSC. For example, check whether there is an abnormalhandover release procedure performed by the MSC.

l If there is such a procedure, find out the specific cause and then rectify the fault. If the faultis rectified, end the troubleshooting; otherwise, go to Step 4.

l If there is no such a procedure, go to Step 4.

Step 4 If the source or target BSC fails to lock the MSC clock, find out the cause and rectify the fault.For detailed operations, refer to 5.2.1 Troubleshooting Clock Source Faults.l If the fault is rectified, end the troubleshooting.l If the fault persists, contact the Huawei Customer Service Center by referring to 1.3.1

Obtaining Technical Support.

----End

6.2.5 Troubleshooting Other Handover FaultsThis describes how to troubleshoot other handover faults by analyzing traffic statistics in depthand mastering the features of the handovers with high failure rates.

Possible CausesThe possible causes of other handover faults are cell congestion, poor quality of transmissionon the Um interface, and signaling problem on the A interface.

NOTE

The following procedure helps analyze configuration data in depth for troubleshooting.

Procedure

Step 1 Determine the type of handovers with high failure rates by referring to 6.1.3 Counters Relatedto Handover Faults. The handover may be intra-cell handover, handover from a cell in the sameBSC, handover to a cell in the same BSC, handover from a cell in another BSC, handover to acell in another BSC, handover from a cell in another system, or handover to a cell in anothersystem.

Step 2 Based on the specific counter and signaling tracing result, find the cause of the handover fault.

Step 3 If the cause of the handover fault is still unclear, contact the Huawei Customer Service Centerby referring to 1.3.1 Obtaining Technical Support.

----End




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7 Congestion Faults

About This Chapter

This describes congestion faults in terms of the symptoms, troubleshooting methods, and typicalcases.

7.1 Congestion Fault SymptomsThis describes the impacts of congestion faults on services, possible alarms, and involvedperformance counters.

7.2 Congestion Troubleshooting MethodsThis describes how to troubleshoot congestion faults. Basically, when a congestion fault occurs,first deal with the reported alarm, then determine the subclass of the fault, and finally rectify thefault.

7.3 Typical Cases of Troubleshooting Congestion Faults

HUAWEI BSC6000 Base Station SubsystemBSS Troubleshooting Guide 7 Congestion Faults


7-1

7.1 Congestion Fault SymptomsThis describes the impacts of congestion faults on services, possible alarms, and involvedperformance counters.

7.1.1 Impacts of Congestion Faults on ServicesThis describes the impacts of congestion faults on calls, SMSs, and BTS maintenance.

7.1.2 Alarms Related to Congestion FaultsThis describes the alarms related to congestion faults. The alarms help locate and rectify thefaults.

7.1.3 Counters Related to Congestion FaultsThis describes the counters related to congestion faults. The counters help locate and rectify thefaults.

7.1.1 Impacts of Congestion Faults on ServicesThis describes the impacts of congestion faults on calls, SMSs, and BTS maintenance.

When a congestion fault occurs, pages of the calling parties and the called parties cannot beprocessed, SMSs cannot be sent or received, or the BTS cannot be maintained. Congestionmainly occurs on the radio channels, Abis interface, and A interface.

7.1.2 Alarms Related to Congestion FaultsThis describes the alarms related to congestion faults. The alarms help locate and rectify thefaults.

Alarms Related to BTS Congestion Faults

Table 7-1 lists the alarms related to BTS congestion faults.

Table 7-1 Alarms related to BTS congestion faults


The E1 transmission is faulty, or the congestionstart threshold and congestion end threshold ofLAPD links are set incorrectly.

21001 LAPD Link Congestion

The TRX incurs faults, which leads to thecongestion of Um interface resources in peakhours.

2116 TRX Configuration Alarm

2148 TRX Hardware Alarm

2180 TRX Band Mismatch ARFCN

2196 TRX Clock Critical Alarm

2204 TRX Communication Alarm

7 Congestion FaultsHUAWEI BSC6000 Base Station Subsystem



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Alarms Related to BSC Congestion Faults

Table 7-2 lists the alarms related to BSC congestion faults.

Table 7-2 Alarms related to BSC congestion faults


The E1 transmission on the A interface is faulty,or the bit error rate is high (higher than 10-6), orthe number of configured signaling links is toosmall, which leads to the congestion orunavailability of MTP2 and MTP3 links.


20089 Excessive Loss of E1/T1 Signalsin an Hour

20090 Excessive E1/T1Synchronization Failures in an Hour

20093 E1/T1 Excessive Slip Frames PerHour

21502 MTP3 Layer 3 Congestion

21504 MTP3 Signaling Link2Congestion

21503 MTP3 Link Unavailable

21513 MTP2 Link Location Failure

21514 MTP2 Link Service Disrupted

7.1.3 Counters Related to Congestion FaultsThis describes the counters related to congestion faults. The counters help locate and rectify thefaults.

Table 7-3 lists the counters related to congestion faults.

Table 7-3 Counters related to congestion faults

Counter Description

H382A Failed Cell Incoming Handovers (Congestion)

A3050 Rejects to Service Requests (Congestion)

L6007 Duration of MTP3 Link Congestion

L6015 MTP3 Link Congestions

L6016 Discarded MSUs during Link Congestion

L3188G LOAD IND Messages Sent on the A Interface

R3202B TCH Assignment Requests (Underlaid SubcellPreferred)



7-3

Counter Description

R3203B TCH Assignment Requests (Overlaid SubcellPreferred)

R3202D Channel Assignment Requests in Incoming InternalInter-Cell Handover Procedure (TCH)(UnderlaidSubcell Preferred)

R3203D Channel Assignment Requests in Incoming InternalInter-Cell Handover Procedure (TCH) (OverlaidSubcell Preferred)

R3202E Channel Assignment Requests in Incoming ExternalInter-Cell Handover Procedure (TCH) (UnderlaidSubcell Preferred)

R3203E Channel Assignment Requests in Incoming ExternalInter-Cell Handover Procedure (TCH) (OverlaidSubcell Preferred)

R3225K Failed Handovers from Overlaid Subcell toUnderlaid Subcell due to Busy Channels in UnderlaidSubcell

R3162B Number of Failures to Allocate Abis Resources(TCHF)



7.2 Congestion Troubleshooting MethodsThis describes how to troubleshoot congestion faults. Basically, when a congestion fault occurs,first deal with the reported alarm, then determine the subclass of the fault, and finally rectify thefault.

Procedure






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Table 7-4 Congestion troubleshooting methods


On the M2000 Client, check the traffic onthe SDCCH and TCH. The result showsthat the traffic exceeds the designed.

7.2.1 Troubleshooting High Traffic

On the M2000 Client, check the traffic onthe TCH. The result shows that the trafficincreases suddenly during a short period.

7.2.2 Troubleshooting Burst Traffic

On the BSC6000 Local MaintenanceTerminal, check the running state of theBTS. The result shows that a TRX isfaulty.

7.2.3 Troubleshooting TRX Faults

On the BSC6000 Local MaintenanceTerminal, check the channel interferenceband. The result shows that interference isexistent.

7.2.4 Troubleshooting Interference Problems

On the BSC6000 Local MaintenanceTerminal, check the circuit resource onthe A interface. The result shows that theconfigured circuits are insufficient orsome circuits are blocked or faulty.

7.2.5 Troubleshooting InsufficientTerrestrial Resources

On the BSC6000 Local MaintenanceTerminal, check the circuit resource onthe Abis interface. The result shows thatthe configured Abis timeslots areinsufficient or some Abis timeslots areblocked or faulty.

7.2.6 Troubleshooting Insufficient AbisResources


----End

7.2.1 Troubleshooting High TrafficThis describes how to troubleshoot high traffic. When a high traffic fault occurs, the query resulton the M2000 Client shows that the traffic on the TCH is obviously higher than the average.

Fault Symptoms

The symptoms of high traffic are as follows:

l The traffic in each of recent days is higher than the designed. On the M2000 Client, youcan obtain the Traffic Volume on TCH.

l More than 90% of the channel resource and circuit resource are occupied at traffic hours.On the BSC6000 Local Maintenance Terminal, you can obtain the TCH status at peak



7-5

hours by referring to Monitoring Channel Status and the circuit resource usage on the Ainterface by referring to Maintaining the Circuits on the A Interface.

Possible Causes

High traffic is possibly caused by too many subscribers.

Procedure

Expand the system capacity by referring to BSS Capacity Expansion Guide. Alternatively,take traffic-sharing measures to relieve congestion.

----End

7.2.2 Troubleshooting Burst TrafficThis describes how to troubleshoot a sudden increase in traffic within a short period.

Fault Symptoms

The symptoms of burst traffic are as follows:

l More than 90% of the channel resource and circuit resource are occupied at traffic hours.On the BSC6000 Local Maintenance Terminal, you can obtain the TCH status at peakhours by referring to Monitoring Channel Status and the circuit resource usage on the Ainterface by referring to Maintaining the Circuits on the A Interface.

l The circuit resource usage at peak hours is obviously higher than the average in the sametime segment on other days. You can obtain the Mean Number of Busy Circuits on theA Interface at peak hours on the M2000 Client.

l Traffic in a time segment is obviously higher than that in other time segments of the day.You can obtain the Traffic Volume on TCH on the M2000 Client.

Possible Cause

Burst traffic is possibly caused by a big event such as a football game or concert in an area withina period.

Procedure

To relieve congestion in the case of burst traffic, do as follows:l Enable some half-rate channels in this period to make more channels available. For detailed

operations, refer to Modifying Channel Attributes (Full Rate and Half Rate).l Add SDCCHs in this period and enable dynamic conversion between SDCCH and TCH.

For detailed operations, refer to Modifying Channel Attributes (TCH and SDCCH).

----End

7.2.3 Troubleshooting TRX FaultsThis describes how to troubleshoot TRX faults. When a TRX fault occurs, a TRX-related alarmis reported.




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Possible Causes

The possible causes of TRX faults are as follows:

l The TRX hardware is faulty.

l A failure occurs in transmission between the TRX and the BTS CDU, and a VSWR alarmis reported.

l An LAPD link is faulty.

Procedure

Step 1 Rectify the fault according to the alarm help. The alarm reported may be 2116 TRXConfiguration Alarm, 2148 TRX Hardware Alarm, 2180 TRX Band Mismatch ARFCN,2196 TRX Clock Critical Alarm, or 2204 TRX Communication Alarm.l If the fault is rectified, end the troubleshooting.l If the fault persists, go to Step 2.

Step 2 Check the status of the TRX.1. On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, click

the corresponding BTS. A dialog box is displayed, as shown in Figure 7-1.

Figure 7-1 Site device panel

2. Determine the TRX status based on the description of the color on the right of Figure7-1.



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l If the TRX status is Error/Locked (Auto), you can infer that the BTS is not powered. Resetand reload the TRX board.

l If the TRX status is not Error/Locked (Auto), go to Step 3.

Step 3 If the TRX fault cannot be confirmed, check the cable connections and VSWR of the antennasystem. For detailed operations, refer to Testing the Antenna System and Measuring theVSWR at the Antenna Port. If all pass the check, replace the TRX board and then check theservices.l If the services are restored, end the troubleshooting.l If the services are not restored, contact the Huawei Customer Service Center by referring

to 1.3.1 Obtaining Technical Support.

----End

7.2.4 Troubleshooting Interference ProblemsThis describes how to troubleshoot interference problems. Interference can be detected throughdialing test on the Um interface or through monitoring of the channel interference band.

Fault SymptomsThe interference symptoms are as follows:

l The MS sends channel request messages to two cells each time the MS originates a call.You can detect this symptom by making test calls and tracing signaling messages on theUm interface on the BSC6000 Local Maintenance Terminal. For detailed operations,refer to Tracing CS Domain Messages on the Um Interface.This symptom indicates that the BCCHs in the two cells are configured with the samefrequency. Thus, in the cell that is selected by mistake, there are many invalid SDCCHrequest messages, which leads to congestion. This symptom always occurs at peak hours.

l The level of interference including adjacent-channel interference is higher than theexpected. You can monitor the channel interference band on the BSC6000 LocalMaintenance Terminal. For detailed operations, refer to Monitoring ChannelInterference Band.When this symptom occurs, the MS cannot receive the commands sent by the BSC andtherefore applies for channels repeatedly, which leads to congestion in the SDCCH or TCH,especially at peak hours.

Possible CausesThe possible causes of interference are as follows:

l Intra-network interference

l Interference from repeaters

l Interference from other high-power communication equipment

l Hardware fault

Procedurel For the first fault symptom, configure the BCCHs in the two cells with different frequencies

by referring to Modifying TRX Frequencies.




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l For the second fault symptom, rectify the fault by referring to Analysis of InterferenceProblems. Alternatively, adjust the frequency hopping mode by referring to Changing theFH Mode.

----End

7.2.5 Troubleshooting Insufficient Terrestrial ResourcesThis describes how to troubleshoot insufficient terrestrial resources on the A interface that is notbased on IP. When the terrestrial resources are insufficient, the MS cannot originate a call.

Fault SymptomsMany circuits are occupied or congested for a long time. You can check the status of the circuitson the A interface on the BSC6000 Local Maintenance Terminal. For detailed operations,refer to Maintaining the Circuits on the A Interface.

Possible CausesThe possible causes of insufficient terrestrial resources on the A interface that is not based onIP are as follows:

l If many circuits are occupied for a long time, you can infer that the configured circuits areinsufficient.

l If the circuits are congested, you can infer that some circuits are blocked or faulty.

ProcedureTo rectify the fault, do as follows:l If many circuits are occupied for a long time, add E1s/T1s on the A interface.

– When the BM and the TC are configured in different subracks, operate according toAdding an A Interface E1/T1.

– When the BM and the TC are configured in the same subrack, operate according toAdding an A Interface E1/T1.

l If some circuits are blocked or faulty, do as follows:– If some circuits are blocked, unblock them by referring to Unblock A Interface CIC

(UBL ACIC).– If some circuits are faulty, you can infer that a fault occurs in transmission or the interface

board. In this case, operate according to 4.2.9 Troubleshooting E1/T1 TransmissionFaults.

----End

7.2.6 Troubleshooting Insufficient Abis ResourcesThis describes how to troubleshoot insufficient Abis resources, because of which no call can beadmitted.

Fault SymptomsMany Abis timeslots are occupied for a long time, which you can check on the BSC6000 LocalMaintenance Terminal by referring to Querying the Status of the Abis Interface Timeslot.



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Possible CausesThe possible cause of insufficient Abis resources is that the configuration is improper.

ProcedureTo rectify the fault, do as follows:l Adjust Abis timeslot assignment by referring to and Manually Assigning the Abis

Timeslots.l Select the Abis Resource Adjustment TCHH Function Switch.

1. On the Management Tree tab page of the BSC6000 Local MaintenanceTerminal, right-click the cell and then select Configure Cell Attributes from theshortcut menu.

2. Double-click the cell in the Cell view box to add it to the Selected cells box, and thenclick Next.

3. Click Set Cell Properties. The Set Cell Attributes dialog box is displayed.4. Click Call Control. A dialog box is displayed, as shown in Figure 7-2.

Set Abis Resource Adjustment TCHH Function Switch to Yes.

Figure 7-2 Setting Call Control Parameter dialog box

----End




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7.3 Typical Cases of Troubleshooting Congestion Faults

7.3.1 Case: TCH Congestion Due to TRX FaultsThis describes a typical case of troubleshooting the TCH congestion caused by TRX faults. TheTRX faults lead to the abnormal communication of the TRX board and the increase of TCHcongestion. To rectify the fault, reset or replace the TRX board.

7.3.2 Case: SDCCH Congestion Due to LAC Configuration FaultsThis describes a typical case of troubleshooting the SDCCH congestion caused by LACconfiguration faults. To rectify the faults, you need to modify the LAC configuration.

7.3.1 Case: TCH Congestion Due to TRX FaultsThis describes a typical case of troubleshooting the TCH congestion caused by TRX faults. TheTRX faults lead to the abnormal communication of the TRX board and the increase of TCHcongestion. To rectify the fault, reset or replace the TRX board.

Fault SymptomsQuery the alarm information and the result shows that the communication of some TRX boardsis abnormal. The traffic statistics information shows that the congestion rate on the TCHincreases.

Fault Location and RectificationDuring call setup, the faults in some TRX boards lead to the decrease of available TCH resources.Especially in high traffic, a large number of Assignment Request messages are sent, which meansthat the TCH resources are unavailable, and therefore the TCHs are shortly congested and pagingaccess fails.

1. To reset the TRX board, refer to Resetting a TRX.l If the fault is rectified, end the troubleshooting.

l If the fault persists, go to 2.

2. Replace the TRX board.

7.3.2 Case: SDCCH Congestion Due to LAC Configuration FaultsThis describes a typical case of troubleshooting the SDCCH congestion caused by LACconfiguration faults. To rectify the faults, you need to modify the LAC configuration.

Fault SymptomsAll the MSs in the cell fail to update locations. A large number of Location Updating Rejectmessages are traced, which leads to the congestion on the SDCCH.

Fault Location and Rectification1. Check the LAC configuration between the MSC and the BSC. You can find the LAC

configuration is inconsistent between the two sides.



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2. Modify the LAC configuration on the BSC side to keep it consistent with that on the MSCside. For details, refer to Step 1 described in 8.2.2 Troubleshooting Data ConfigurationFaults.




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8 Access Faults

About This Chapter

This describes access faults in terms of the symptoms, troubleshooting methods, and typicalcases.

8.1 Access Fault SymptomsThis describes the impacts of access faults on services, possible alarms, and involvedperformance counters.

8.2 Access Troubleshooting MethodsThis describes how to troubleshoot access problems. Basically, when an access problem occurs,first deal with the reported alarm, then determine the subclass of the fault, and finally rectify thefault.

8.3 Typical Cases of Troubleshooting Access FaultsThis describes the typical cases of troubleshooting access faults.

HUAWEI BSC6000 Base Station SubsystemBSS Troubleshooting Guide 8 Access Faults


8-1

8.1 Access Fault SymptomsThis describes the impacts of access faults on services, possible alarms, and involvedperformance counters.

8.1.1 Impacts of Access Faults on ServicesThis describes the impacts of access faults on services. When an access fault occurs, the MScannot receive radio signals or register with the network, the MS drops the call frequently, orthe MS cannot make calls or be called after the registration.

8.1.2 Alarms Related to Access FaultsThis describes the alarms related to access faults. The alarms help locate and rectify the faults.

8.1.3 Counters Related to Access FaultsThis describes the counters related to access faults. The counters help locate and rectify thefaults.

8.1.1 Impacts of Access Faults on ServicesThis describes the impacts of access faults on services. When an access fault occurs, the MScannot receive radio signals or register with the network, the MS drops the call frequently, orthe MS cannot make calls or be called after the registration.

8.1.2 Alarms Related to Access FaultsThis describes the alarms related to access faults. The alarms help locate and rectify the faults.

Table 8-1 lists the alarms related to access faults.

Table 8-1 Alarms related to access faults


Link faults 1000 LAPD OML Fault


103 All SS7 Links Faulty

21525 SCCP DSP Unreachable


Equipment faults 4732 TMU clock critical alarm

5298 CDU VSWR Critical Alarm

4192 TRX communication alarm

2148 TRX Hardware Alarm

21210 CPU Overload

405 Cell Out of Service

8 Access FaultsHUAWEI BSC6000 Base Station Subsystem



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8.1.3 Counters Related to Access FaultsThis describes the counters related to access faults. The counters help locate and rectify thefaults.

Table 8-2 lists the counters related to access faults.

Table 8-2 Counters related to access faults

Counter Description

CA300J Channel Requests (Circuit Service)

A300H Channel Requests (Packet Call)

A301H Immediate Assignment Commands (PS)

A3010 Immediate Assignment Commands (SDCCH)

A3017 Immediate Assignment Commands (TCHF)

A3018 Immediate Assignment Commands (TCHH)

CA301J Immediate Assignment Commands (Circuit Service)

A301B Immediate Assignment Commands (Non-Call Type)

A301A Immediate Assignment Commands (Call Type)

A302J Rejects to Immediate Assignments (CS)

A302H Rejects to Immediate Assignments (PS)

A3030 Call Setup Indications (SDCCH)

CA3030J Call Setup Indications (SDCCH) (Circuit Service)

CA3039J Call Setup Indications (TCH) (Circuit Service)

A3037 Call Setup Indications (TCHF)

A3038 Call Setup Indications (TCHH)

CA303J Call Setup Indications (Circuit Service)

CA303B Call Setup Indications (Non-Call Type)

CA303H Call Setup Indications (Packet Service)

CA303A Call Setup Indications (Call Type)

CA304 Call Setup Indications Timed Out

CA305 Rejects to Service Requests



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8.2 Access Troubleshooting MethodsThis describes how to troubleshoot access problems. Basically, when an access problem occurs,first deal with the reported alarm, then determine the subclass of the fault, and finally rectify thefault.

Procedure



Table 8-3 Access troubleshooting methods


l The number of channel requests issmaller than a preset value.

l The number of setup indications issmaller than a preset value.

l The immediate assignment success rateis lower than a preset value.

l The call drop rate of the SDCCH ishigher than a preset value.

8.2.1 Troubleshooting Um Interface QualityProblems

l The MSC rejects the service requestfrom the MS.

l The number of expirations of the setupindication timer is larger than a presetvalue.

l The immediate assignment success rateis lower than a preset value.

l The congestion rate of the SDCCH ishigher than a preset value.

l The paging success rate is lower than apreset value.

8.2.2 Troubleshooting Data ConfigurationFaults

A link fault alarm is reported. 4 Link Faults


----End

8.2.1 Troubleshooting Um Interface Quality ProblemsThis describes how to troubleshoot Um interface quality problems, because of which the MScannot receive signals or the received signals are unstable.




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Possible Causes

The possible causes of Um interface quality problems are as follows:

l The equipment is faulty or the network planning is improper. In this case, the coverage ofthe network is unsatisfied.

l UL and DL signals are unbalanced on the Um interface, or UL signals are greatly affectedby interference.

Procedure

Step 1 Check whether the equipment is faulty.

On the BSC6000 Local Maintenance Terminal, check the kickoff status of the cell and thestatus of each board of the BTS in the Figure 8-1 dialog box. For detailed operations, refer toQuerying BTS Attributes.

Figure 8-1 Check the kickoff status of the cell

If the Operation status is Enabled, check whether each board of the BTS is faulty.

l If faulty, replace the board and the antenna.


Step 2 Check the relevant parameter settings.

1. On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, right-click the TRX and then select Configure TRX Attributes from the shortcut menu.

2. In the displayed TRX attribute configuration wizard dialog box, click Configure TRXAttributes.



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3. In the displayed dialog box, select the Device Attributes tab page, as shown in Figure8-2.

Figure 8-2 Configure TRX Attributes dialog box

Set the Power Level to adjust the TRX power, thus solving the problem of unbalancing betweenUL and DL signals.

CAUTIONA higher power level indicates a lower power value. Power level 0 indicates the maximum powervalue.

l If the fault is rectified, end the troubleshooting.l If the fault persists, go to Step 3.

Step 3 Perform frequency scanning and reselect the BCCH frequency for the cell.1. On the BSC6000 Local Maintenance Terminal, perform frequency scanning to determine

the interference to each frequency. Select a frequency with the lowest interference as theBCCH frequency. For detailed operations, refer to Configuring Frequency Scan. For theconfiguration dialog box, see Figure 8-3.




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Figure 8-3 Configure Frequency Scan dialog box

2. After you click Start in the dialog box as shown in Figure 8-3, the BTS starts to scanfrequencies 512 to 517 at the specified time.

On the BSC6000 Local Maintenance Terminal, the frequency scanning result shows theinterference to each frequency in the uplink. The smaller the value, the lower theinterference. For detailed operations, refer to Querying Frequency Scan Results.

Select an idle frequency with the lowest interference as the BCCH frequency of the cell.

CAUTIONAfter the frequency scanning task is complete, click Stop in the Configure FrequencyScan dialog box. Otherwise, the BTS scans these frequencies once every day.

l If the fault is rectified, end the troubleshooting.l If the fault persists, contact the Huawei Customer Service Center by referring to 1.3.1


----End

8.2.2 Troubleshooting Data Configuration FaultsThis describes how to troubleshoot the faults in data configuration. The fault symptoms showthat all the MSs in the cell fail to register in the network, a large number of MSC-rejected servicesoccur in traffic statistics, the uplink and downlink signals on the Um interface are unbalanced,or the uplink signals interfere strongly.

Possible CausesThe possible causes are as follows:



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l The data configuration is inconsistent between the BSC and the MSC.

l The cell-related parameters are not properly set.

Procedure

Step 1 Check whether the data configuration is inconsistent between the BSC and the MSC.

Determine the fault coverage, that is, whether the fault occurs in all the cells or only a few cellsin the coverage of the BSC.

l If the fault occurs in all the cells in the coverage of the BSC, check the global configurationdata as follows:– When the BM and the TC are configured in different subracks, see Configuring the

BSC Attributes for details.– When the BM and the TC are configured in the same subrack, see Configuring the

BSC Attributes for details.– When the A interface uses the IP transmission mode, see Configuring the BSC

Attributes for details.l If the fault occurs in a few cells in the coverage of the BSC, check the configuration data

of specified cells as follows:

1. On the BSC6000 Local Maintenance Terminal, right-click a cell on theManagement Tree tab page. Then, choose Configure Cell Attributes.

2. On the Configure Cell Attributes dialog box, select the cell, and click Next.3. Click Configure Cell Attributes. In the displayed Set Cell Attributes dialog box,

check the following parameters: MCC, MNC, LAC, and CI, as shown in Figure8-4.




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Figure 8-4 Set Cell Attributes dialog box

CAUTIONThe parameter configuration mentioned above must be kept consistent between the BSC and theMSC.

l If the configuration is inconsistent, modify the parameters to keep them consistent.

l If the configuration is consistent, go to Step 2.

Step 2 Check whether the cell access parameters are set properly.

If the access fault occurs in a few cells but not because the MSC rejects services, check whetherthe cell access parameters are set properly, and verify the parameters related to the cells in idlemode and the cell timer, as shown in Figure 8-5 and Figure 8-6.



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Figure 8-5 Parameters related to the cells in idle mode

Figure 8-6 Parameters related to the cell timer

l If the fault persists after the parameters are set correctly, contact the Huawei CustomerService Center by referring to 1.3.1 Obtaining Technical Support.

l If the parameters are set incorrectly, reconfigure the parameters. If the fault persists afterreconfiguration, contact the Huawei Customer Service Center by referring to 1.3.1Obtaining Technical Support.

----End




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8.3 Typical Cases of Troubleshooting Access FaultsThis describes the typical cases of troubleshooting access faults.

8.3.1 Case: MS Access Failure Due to Weak SignalsThis describes a typical case of troubleshooting the MS access failure due to weak signals. TheMS fails to access the network because the signals are weak. To solve the problem, you cancheck the cell coverage and tilt the antenna.

8.3.2 Case: MS Cell Reselection Failure Due to Weak Signals of Neighboring CellsThis describes a typical case of troubleshooting the MS cell reselection failure. The MS fails toperform cell reselection because the signals in the neighboring cells are weak. To solve theproblem, you can check the data configuration, adjust the power level, or tilt the antenna.

8.3.3 Case: MS Network Disconnection Due to Location Update Period Set Too SmallThis describes a typical case of troubleshooting the MS network connection failure. The MS isdisconnected from the network because the location update period is set too small. To solve theproblem, you need to modify related parameters.

8.3.4 Case: MS Network Disconnection Due to Incorrect CGI ConfigurationThis describes a typical case of troubleshooting the MS network connection failure due toincorrect CGI configuration. To solve the problem, you can modify the CGI parameters.

8.3.5 Case: MS Access Failure Due to Incorrect CBQ/CBA SettingThis describes a typical case of troubleshooting the MS access failure due to the incorrect CBQ/CBA setting. To solve the problem, you can modify the related parameters.

8.3.6 Case: MS Access Failure Due to Incorrect Setting of Minimum RACH Access LevelThis describes a typical case of troubleshooting the MS access failure due to the incorrect settingof the minimum RACH access level. To solve the problem, you must modify the relatedparameters.

8.3.1 Case: MS Access Failure Due to Weak SignalsThis describes a typical case of troubleshooting the MS access failure due to weak signals. TheMS fails to access the network because the signals are weak. To solve the problem, you cancheck the cell coverage and tilt the antenna.

Fault Symptoms

The MS is located in the poor coverage of signals and thus fails to access the network due toweak signals.

Fault Location and Rectification1. Check the cell coverage and determine whether the MS is located at the edge of a cell. If

not, go to 2.2. Reduce the power level of the BCCH TRX of the cell.3. Check whether the height, location, and azimuth of the antenna are set properly. If not,

adjust them.4. After adjustment, the MS in its original location can access the network normally.



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8.3.2 Case: MS Cell Reselection Failure Due to Weak Signals ofNeighboring Cells

This describes a typical case of troubleshooting the MS cell reselection failure. The MS fails toperform cell reselection because the signals in the neighboring cells are weak. To solve theproblem, you can check the data configuration, adjust the power level, or tilt the antenna.

Fault SymptomsThe MS in idle mode fails to perform cell reselection. It incurs a call drop first and then registersin the network.

Fault Location and Rectification1. Check whether the neighboring cell mapping data is correct.2. Check whether the level signal of the neighboring cell is weak. If so, reduce the power level

of the BCCH TRX of the neighboring cell.3. Check whether the height, location, and azimuth of the neighboring BTS are set properly.

If not, adjust them.4. Increase the height of the antenna to strengthen the signals of neighboring cells.5. If the fault persists, set the cell of the non-neighboring BTS as a neighboring cell and

enhance the redundancy of neighboring cells until the MS can perform cell reselectionnormally.

6. After the previous adjustment, the MS in idle mode performs cell reselection successfullyand incurs no call drops.

8.3.3 Case: MS Network Disconnection Due to Location UpdatePeriod Set Too Small

This describes a typical case of troubleshooting the MS network connection failure. The MS isdisconnected from the network because the location update period is set too small. To solve theproblem, you need to modify related parameters.

Fault SymptomsAn office has four BTSs, and the network runs normally. One day, however, the MSs aresuddenly disconnected from the network.

Fault Location and Rectification1. Check the hardware.

l Check whether the BTS equipment reports alarms. For details, see 8.1.2 AlarmsRelated to Access Faults.

l On the BSC6000 Local Maintenance Terminal, check whether all the BSC boardsrun normally.

If no alarms are reported or no hardware is faulty, then the BTS hardware has no problem.2. Check the configuration data.

Recently, the office has no configuration data modified but only the number of MSs greatlyincreases. According to the VLR, the number of local MSs is over 4000 and the number of




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roaming MSs is more than 5000. The problem may be caused by the sharp increase of MSs,which burdens the network in the following aspects:l High TCH congestion rate

If all the TCHs in some areas are occupied, then other MSs cannot make calls.l High SDCCH congestion rate

If all the SDCCHs in some areas are occupied, then the MSs cannot perform signalinginteraction. In addition, the MSs can neither make or receive calls nor perform locationupdate, and the location update failure directly leads to MS disconnection from thenetwork.

3. Check the BSC idle parameters.The time of periodic location update is set to 12 minutes for the BSC and 30 minutes forthe MSC. The setting means that all the activated MSs initiate a periodic location updateto the SDCCH every 12 minutes. When the number of MSs reaches a certain level, all theSDCCHs are occupied. At this time, if the MSs initiate the periodic location update again,the MSs may fail the location update because there are no idle SDCCHs and thus the MSswill be disconnected from the network.

4. Modify the configuration data.On the BSC6000 Local Maintenance Terminal, set Period of Periodic Location Update(6 minutes) to 10, that is, 60 minutes. For details, refer to Step 2 described in 8.2.2Troubleshooting Data Configuration Faults. In addition, set the period for the MSC to180 minutes.

8.3.4 Case: MS Network Disconnection Due to Incorrect CGIConfiguration

This describes a typical case of troubleshooting the MS network connection failure due toincorrect CGI configuration. To solve the problem, you can modify the CGI parameters.

Fault SymptomsThe MS can receive the signals from the BTS but cannot access the network.

Fault Location and Rectification1. On the BSC6000 Local Maintenance Terminal, query the status of TRXs and channels.

The TRXs, channels, and the A interface are all normal, but the MS cannot access thenetwork. Also, the MS sends the location update failure message. For details, refer toQuerying BTS Running Status and Maintaining the Circuits on the A Interface.The probable cause is that the CGI configuration is inconsistent between the MSC side andthe BSC side.

2. Check the CGI parameter configuration on the BSC side. For details, refer to Step 1described in 8.2.2 Troubleshooting Data Configuration Faults.

3. Modify the CGI configuration to keep the parameters consistent between the MSC side andthe BSC side. The MS can access the network after the CGI configuration is kept consistentbetween the two sides.

8.3.5 Case: MS Access Failure Due to Incorrect CBQ/CBA SettingThis describes a typical case of troubleshooting the MS access failure due to the incorrect CBQ/CBA setting. To solve the problem, you can modify the related parameters.



8-13

Fault SymptomsThe fault symptoms of the MS access failure are as follows:

l The MS displays that it fails to search the network, or the MS displays no information.

l The MS displays that the network list contains no originating network.

Fault Location and Rectification1. Check the cell data configuration. For details, refer to Step 2 described in 8.2.2

Troubleshooting Data Configuration Faults.The parameters Cell_Bar_Access (CBA) and Cell_Bar_Access (CBQ) affect the cellreselection of the MS.

2. Reset the CBQ and CBA according to the priorities of cell selection and reselection.3. After the related parameters are modified, the MS can select or reselect the cell normally.

8.3.6 Case: MS Access Failure Due to Incorrect Setting of MinimumRACH Access Level

This describes a typical case of troubleshooting the MS access failure due to the incorrect settingof the minimum RACH access level. To solve the problem, you must modify the relatedparameters.

Fault SymptomsThe fault symptoms are as follows:

l The MS displays that it fails to search the network, or the MS displays no information.

l The MS searches one or more networks.

l Most of the MSs cannot access the cell.

l No request message is available on the Abis interface.

Fault Location and Rectification1. Check the data configuration of the cell. The result shows that the RACH Min. Access

Level is set incorrectly.RACH Min. Access Level refers to the level threshold for the random access of the MSto the BTS. When the random access level of the burst timeslot is greater than the value ofRACH Min. Access Level, the BTS considers that the timeslot has an access request, anddetermines together with the value of Random Access Error Threshold whether theRACH access is valid.

2. According to the BTS sensitivity and the MS minimum access level, you can modify theRACH Min. Access Level parameter and perform the following operations:

(1) On the BSC6000 Local Maintenance Terminal, right-click a cell on theManagement Tree tab page. Then, choose Configure Cell Attributes.

(2) On the Configure Cell Attributes dialog box, select the cell, and click Next.(3) Click Set Cell Properties. The dialog box Set Cell Attributes is displayed. Click

Call Control. A dialog box is displayed. Click Advanced. A dialog box is displayed,as shown in Figure 8-7.




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Figure 8-7 Call Control dialog box

3. The MS can access the network normally after the parameter is modified.



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9 PS Service Faults

About This Chapter

This describes PS service faults in terms of the symptoms, troubleshooting methods, and typicalcases.

9.1 PS Service Fault SymptomsThis describes the impacts of PS service faults on services, possible alarms, and involvedperformance counters.

9.2 PS Service Troubleshooting MethodsThis describes how to troubleshoot different PS service faults. Basically, when a PS service faultoccurs, first deal with the reported alarm, then determine the subclass of the fault, and finallyrectify the fault.

9.3 Typical Cases of Troubleshooting PS Service FaultsThis describes the typical cases of troubleshooting PS service faults.

HUAWEI BSC6000 Base Station SubsystemBSS Troubleshooting Guide 9 PS Service Faults


9-1

9.1 PS Service Fault SymptomsThis describes the impacts of PS service faults on services, possible alarms, and involvedperformance counters.

9.1.1 Impacts of PS Service Faults on ServicesThis describes the impacts of PS service faults on services. When a PS service fault occurs, theMS cannot access the GPRS network or the MS cannot obtain GPRS services although it canaccess the GPRS network.

9.1.2 Alarms Related to PS Service FaultsThis describes the BSS alarms related to PS service faults. The alarms help locate and rectifythe faults.

9.1.3 Counters Related to PS Service FaultsThis describes the counters related to PS service faults. The counters help locate and rectify thefaults.

9.1.1 Impacts of PS Service Faults on ServicesThis describes the impacts of PS service faults on services. When a PS service fault occurs, theMS cannot access the GPRS network or the MS cannot obtain GPRS services although it canaccess the GPRS network.

9.1.2 Alarms Related to PS Service FaultsThis describes the BSS alarms related to PS service faults. The alarms help locate and rectifythe faults.

Table 9-1 lists the alarms related to the PS service faults in the case of using the external PCU.

Table 9-1 Alarms related to PS service faults (external PCU)


The congestion start threshold and thecongestion end threshold of the LAPD linkson the Pb interface are improperly set, or theLAPD signaling load exceeds the congestionstart threshold of the LAPD links.

21001 LAPD Link Congestion

The LAPD link on the Pb interface cannotreceive any messages from the peer end(PCU).


The E1 transmission is faulty on the Pbinterface and the bit error rate is high (higherthan 10-6).


20089 Excessive Loss of E1/T1 Signals inan Hour


9 PS Service FaultsHUAWEI BSC6000 Base Station Subsystem



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20093 E1/T1 Excessive Slip Frames PerHour

All the PBSLs between the BSC and the PCUare faulty.


The one-way audio occurs in a PBSL betweenthe BSC and the PCU.

105 ONE PBSL Link SINGLE PASS

The circuit with an alarm flag is notconfigured on the BSC side but on the PCUside.

127 No Pb Interface Circuit Configured onthe BSC side

The circuit with an alarm flag is notconfigured on the PCU side but on the BSCside.

128 No Circuit Configured in the PCU

The BSC sends the PCU the messageindicating that the BSC blocks the circuit withmaximum retransmissions, but the PCU doesnot respond to the messages.

134 BSC Unable to Block a Packet Circuit

The BSC sends the PCU the message that theBSC unblocks the circuit PCU withmaximum retransmissions, but the PCU doesnot respond to the messages.

135 BSC Unable to Unblock a PacketCircuit

The BSC sends the PCU the messageindicating that the BSC resets the circuit withmaximum retransmissions, but the PCU doesnot respond to the messages.

136 BSC Unable to Reset a Packet Circuit

Table 9-2 lists the alarms related to the PS service faults in the case of using the built-in PCU.

Table 9-2 Alarms related to PS service faults (built-in PCU)


The delay of the transmission between BTS and BSC inthe cell is below the lower limit or above the upper limit.

291 Cell Transmission DelayAbnormal

The Gb interface is inaccessible, or the Gb dataconfiguration is incorrect, or the bearer channel isblocked.

293 GB BC Faulty

The BSC supports GPRS/EGPRS but the actual BTSTRXs do not support GPRS/EGPRS.

294 TRX Config Error

The GEPUG is faulty, or the NSVC is blocked, or thebearer channel is inaccessible, or the data configurationis inconsistent between BSC and SGSN.

331 NSVC Faulty



9-3


The GFGUG is faulty, or the network between BSC andSGSN is disconnected, or the data configuration isinconsistent between BSC and SGSN.

332 NSVL Faulty

The Gb interface works abnormally. 333 NSE Faulty

The cell distribution fails or is prohibited by the license,or the Um or Gb interface is blocked.

340 Cell PS Service Faulty

The cell distribution on the DSP exceeds the upper limit. 341 DSP Resource Overload

The PTP BVC signaling flow is abnormal, or the PTPBVC is blocked.

342 PTP BVC Faulty

The communication link between BSC and SGSN isfaulty, or the data configuration of the SERVER IP/UDPport is inconsistent between BSC and SGSN.

343 NSVL DynamicConfiguration Process Failure

Among the 22 DSPs of the GDPUP, the redundant 16DSPs are faulty.

344 FAULTY DSP OVERLIMIT

9.1.3 Counters Related to PS Service FaultsThis describes the counters related to PS service faults. The counters help locate and rectify thefaults.

Table 9-3 lists the counters related to PS service faults in the case of using the external PCU.

Table 9-3 Counters related to PS service faults (external PCU)

Counter Description

AL8351 Mean Number of Faulty Circuits on the Pb Interface

AL8353 Mean Number of Blocked Circuits on the Pb Interface

AL8354 Mean Number of Idle Circuits on the Pb Interface

AL8355 Mean Number of Busy Circuits on the Pb Interface

AL8352 Mean Number of Circuits in Maintenance State on the PbInterface

R3001A Number of Initially Configured Channels (Static PDCH)(900/850 Cell)

R3001B Number of Initially Configured Channels (Static PDCH)(1800/1900 Cell)

R3002A Number of Initially Configured Channels (DynamicPDCH) (900/850 Cell)




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Counter Description

R3002B Number of Initially Configured Channels (DynamicPDCH) (1800/1900 Cell)

R3005A Number of Initially Configured Channels (Static EDGE)(900/850 Cell)

R3005B Number of Initially Configured Channels (Static EDGE)(1800/1900 Cell)

R3006A Number of Initially Configured Channels (DynamicEDGE) (900/850 Cell)

R3006B Number of Initially Configured Channels (DynamicEDGE) (1800/1900 Cell)

AR3011A Mean Number of Dynamically Configured Channels(PDCH) (900/850 Cell)

AR3011B Mean Number of Dynamically Configured Channels(PDCH) (1800/1900 Cell)

AR3015A Mean Number of Dynamically Configured Channels(EDGE) (900/850 Cell)

AR3015B Mean Number of Dynamically Configured Channels(EDGE) (1800/1900 Cell)

AR3021A Mean Number of Available Channels (PDCH) (900/850Cell)

AR3021B Mean Number of Available Channels (PDCH) (1800/1900Cell)

AR3025A Mean Number of Available Channels (EDGE) (900/850Cell)

AR3025B Mean Number of Available Channels (EDGE) (1800/1900Cell)

AR3023A Mean Number of Available Channels (TCHs Convertedfrom Dynamic PDCHs) (900/850 Cell)

AR3023B Mean Number of Available Channels (TCHs Convertedfrom Dynamic PDCHs) (1800/1900 Cell)

AR3024A Mean Number of Available Channels (PDCHs Convertedfrom Dynamic PDCHs) (900/850 Cell)

AR3024B Mean Number of Available Channels (PDCHs Convertedfrom Dynamic PDCHs) (1800/1900 Cell)

L0387 Total Number of Messages Received from PCU

L8387 Messages Received from a PCU

R3140 Requests for TCH from the PCU



9-5

Counter Description

R3141 Successful Requests for TCH from the PCU

A031 SGSN-Initiated Paging Requests for PS Service

A331 SGSN-Initiated Paging Requests for PS Service

A300H Channel Requests (Packet Call)

A301H Immediate Assignment Commands (PS Service)

A302H Rejects to Immediate Assignments (PS Service)

A3030H Call Setup Indications (PS Service) (SDCCH)

A3037H Call Setup Indications (PS Service) (TCHF)

A3038H Call Setup Indications (PS Service) (TCHH)

CA303H Call Setup Indications (Packet Service)

Table 9-4 lists the counters related to PS service faults in the case of using the built-in PCU.

Table 9-4 Counters related to PS service faults (built-in PCU)

Counter Description

A9406 Number of 11-Bit Single Block ChannelRequests Received on RACH

AA9407 Average Interval of Packet AccessRequests on CCCH (s)

A9408 Number of Packet Channel RequestsReceived on PCCCH

AA9409 Average Interval of Packet AccessRequests on PCCCH(s)

A9410 Number of Resource Requests Received onUplink PACCH

A9411 Number of Resource Requests Received onDownlink PACCH

A9501 Number of Uplink Assignments

A9502 Number of Successful Uplink Assignments

A9503 Number of Uplink PS ImmediateAssignments

A9504 Number of Successful Uplink PSImmediate Assignments




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Counter Description

A9505 Number of Uplink Assignments onPACCH

A9506 Number of Successful Uplink Assignmentson PACCH

A9507 Number of Downlink Assignments

A9508 Number of Successful DownlinkAssignments

A9509 Number of Downlink PS ImmediateAssignments

A9510 Number of Successful Downlink PSImmediate Assignments

A9511 Number of Downlink Assignments onPACCH

A9512 Number of Successful DownlinkAssignments on PACCH

A9001 Number of Uplink GPRS TBFEstablishment Attempts

A9002 Number of Successful Uplink GPRS TBFEstablishments

A9003 Number of Failed Uplink GPRS TBFEstablishments due to No Channel

A9004 Number of Failed Uplink GPRS TBFEstablishments due to MS No Response

A9005 Number of Uplink GPRS TBF NormalReleases

A9006 Number of Uplink GPRS TBF AbnormalReleases due to N3101 Overflow (MS NoResponse)

A9007 Number of Uplink GPRS TBF AbnormalReleases due to N3103 Overflow (MS NoResponse)

A9008 Number of Uplink GPRS TBF AbnormalReleases due to SUSPEND

A9009 Number of Uplink GPRS TBF AbnormalReleases due to FLUSH

A9010 Number of Uplink GPRS TBF AbnormalReleases due to No Channel



9-7

Counter Description

A9011 Total Number of Sampled ConcurrentUplink GPRS TBFs

A9012 Sampling Times of Concurrent UplinkGPRS TBFs

A9013 Average Number of Concurrent UplinkGPRS TBFs

A9014 Total Duration of Uplink GPRS TBF (ms)

A9015 Average Duration of Uplink GPRS TBF (s)

A9101 Number of Downlink GPRS TBFEstablishment Attempts

A9102 Number of Successful Downlink GPRSTBF Establishments

A9103 Number of Failed Downlink GPRS TBFEstablishments due to No Channel

A9104 Number of Failed Downlink GPRS TBFEstablishments due to MS No Response

A9105 Number of Downlink GPRS TBF NormalReleases

A9106 Number of Downlink GPRS TBFAbnormal Releases due to N3105 Overflow

A9107 Number of Downlink GPRS TBFAbnormal Releases due to SUSPEND

A9108 Number of Downlink GPRS TBFAbnormal Releases due to FLUSH

A9109 Number of Downlink GPRS TBFAbnormal Releases due to No Channel

A9110 Total Number of Sampled ConcurrentDownlink GPRS TBFs

A9111 Sampling Times of Concurrent DownlinkGPRS TBFs

A9112 Average Number of Concurrent DownlinkGPRS TBFs

A9113 Total Duration of Downlink GPRS TBF(ms)

A9114 Average Duration of Downlink GPRS TBF(s)




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Counter Description

A9201 Number of Uplink EGPRS TBFEstablishment Attempts

A9202 Number of Successful Uplink EGPRS TBFEstablishments

A9203 Number of Failed Uplink EGPRS TBFEstablishments due to No Channel

A9204 Number of Failed Uplink EGPRS TBFEstablishments due to MS No Response

A9205 Number of Uplink EGPRS TBF NormalReleases

A9206 Number of Uplink EGPRS TBF AbnormalReleases due to N3101 Overflow (MS NoResponse)

A9207 Number of Uplink EGPRS TBF AbnormalReleases due to N3103 Overflow (MS NoResponse)

A9208 Number of Uplink EGPRS TBF AbnormalReleases due to SUSPEND

A9209 Number of Uplink EGPRS TBF AbnormalReleases due to FLUSH

A9210 Number of Uplink EGPRS TBF AbnormalReleases due to No Channel

A9211 Total Number of Sampled ConcurrentUplink EGPRS TBFs

A9212 Sampling Times of Concurrent UplinkEGPRS TBFs

A9213 Average Number of Concurrent UplinkGPRS TBFs

A9214 Total Duration of Uplink EGPRS TBF(ms)

A9215 Average Duration of Uplink EGPRS TBF(s)

A9301 Number of Downlink EGPRS TBFEstablishment Attempts

A9302 Number of Successful Downlink EGPRSTBF Establishments

A9303 Number of Failed Downlink EGPRS TBFEstablishments due to No Channel



9-9

Counter Description

A9304 Number of Failed Downlink EGPRS TBFEstablishments due to MS No Response

A9305 Number of Downlink EGPRS TBF NormalReleases

A9306 Number of Downlink EGPRS TBFAbnormal Releases due to N3105 Overflow

A9307 Number of Downlink EGPRS TBFAbnormal Releases due to SUSPEND

A9308 Number of Downlink EGPRS TBFAbnormal Releases due to FLUSH

A9309 Number of Downlink EGPRS TBFAbnormal Releases due to No Channel

A9310 Total Number of Sampled ConcurrentDownlink EGPRS TBFs

A9311 Sampling Times of Concurrent DownlinkEGPRS TBFs

A9312 Average Number of Concurrent DownlinkEGPRS TBFs

A9313 Total Duration of Downlink EGPRS TBF(ms)

A9314 Average Duration of Downlink EGPRSTBF (s)

R9201 Number of RLC Data Blocks Used onPDCH

R9202 Total Number of RLC Data Blocks onPDCH

RR9203 Average PDCH Utilization (%)

L9601 Number of Frames Sent on BC

L9602 Number of Frames Received on BC

L9603 Number of Frames Discarded on BC

L9604 Peak Bytes of NS PDUs Sent on BC

L9605 Peak Bytes of NS PDUs Received on BC

L9701 Number of NS PDUs Sent by NS sublayer(NSVC)

L9702 Number of NS PDUs Received by NSSublayer (NSVC)




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Counter Description

L9703 Number of NS PDUs Discarded by NSSublayer (NSVC)

L9704 Total Bytes of NS PDUs Sent by NSSublayer (NSVC)

L9705 Total Bytes of NS PDUs Received by NSSublayer (NSVC)

R9401 Total Sampled DSP CPU Usage

R9402 Sampling Times of DSP CPU Usage

AR9403 Average DSP CPU Usage (%)

R9404 Peak DSP CPU Usage (%)

R9501 Maximum Number of PDCHs Activatedon DSP

R9502 Minimum Number of PDCHs Activated onDSP

R9503 Total Number of Sampled PDCHsActivated on DSP

R9504 Sampling Times of PDCH Measurementon DSP

AR9505 Average Number of PDCHs Activated onDSP

R9506 Maximum Number of PDCHs Occupiedon DSP

R9507 Minimum Number of PDCHs Occupied onDSP

R9508 Total Number of Sampled PDCHsOccupied on DSP

AR9509 Average Number of PDCHs Occupied onDSP

S9201 Maximum Number of PDCHs Assignedper BSC

S9202 Total Number of Sampled PDCHsAssigned per BSC

S9203 Sampling Times of PDCHs Assigned perBSC

AS9204 Average Number of PDCHs Assigned perBSC



9-11

Counter Description

S9205 Maximum Speed of PS Traffic per BSC(kbit/s)

S9206 Number of Failed PDCH Assignments dueto Congestion

9.2 PS Service Troubleshooting MethodsThis describes how to troubleshoot different PS service faults. Basically, when a PS service faultoccurs, first deal with the reported alarm, then determine the subclass of the fault, and finallyrectify the fault.

Procedure



Table 9-5 PS service troubleshooting methods


On the BSC6000 Local MaintenanceTerminal, find that the GPRS Supportcheck box is not selected.

9.2.1 Troubleshooting a Cell Not SupportingGPRS

On the external PCU LocalWS, check thecell status. The result shows that a cellmalfunctions.

9.2.2 Troubleshooting Cell Faults (ExternalPCU)

On the external PCU LocalWS, trace themessages on the Pb interface and run a cellreset command. The result shows that a cellfails to start work.NOTE

Resetting a cell causes the cell out of service.Perform this operation only when the cell cannotoffer services properly.

9.2.3 Troubleshooting Cell Kickoff Failures(External PCU)

On the external PCU LocalWS, check thePDCH status. The result shows that aPDCH malfunctions.

9.2.4 Troubleshooting PDCH Faults(External PCU)

Check the status of LAPD links on the Pbinterface. The result shows that an LAPDlink malfunctions.

9.2.5 Troubleshooting LAPD Link Faults(External PCU)




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On the M2000 Client or BSC6000 LocalMaintenance Terminal, check the cellconfigurations, physical connections, andport parameter settings.NOTE

Resetting a cell causes the cell out of service.Perform this operation only when the cell cannotoffer services properly.

9.2.6 Troubleshooting Cell Activity StateFaults (Built-in PCU)

Find that an MS or a cell cannot perform PSservices properly.

9.2.7 Troubleshooting Cell ServiceDisruption Faults (Built-in PCU)

Find that the PCU is running properly butall the ongoing services are disruptedsuddenly.

9.2.8 Troubleshooting Global ServiceDisruption Faults (Built-in PCU)

NOTE

For details on the PCU commands, refer to 9.2.9 Commands Executed on the PCU MaintenanceTerminal.


----End

9.2.1 Troubleshooting a Cell Not Supporting GPRSThis describes how to troubleshoot the problem that the MS cannot perform PS services in acell.

Possible CausesThe possible cause of a cell not supporting GPRS is that the cell is configured not to supportGPRS. In this case, the system information issued by the BTS does not carry any PS-relatedinformation, and therefore the MS cannot perform PS services in the cell.

Procedure

Step 1 On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, click thecell and check the cell attributes, as shown in Figure 9-1.



9-13

Figure 9-1 Cell attributes

Step 2 On the Cell Attributes tab page, check whether the GPRS Support check box is selected. If itis not selected, the cell cannot support GPRS.To enable the cell to support GPRS, select the GPRS Support check box and ensure that thecell is configured with PDCHs.

----End

9.2.2 Troubleshooting Cell Faults (External PCU)This describes how to troubleshoot a cell in a malfunctioning state on the external PCU side.

Fault Symptoms

The cell fault symptoms on the external PCU side are as follows:

l The cell has an internal fault, the cell resources are not ready, the equipment is notinitialized, the cell does not support GPRS, the cell does not exist, or the data configurationof the cell is incorrect.

l If the BSC administrative status of the cell is BLOCKED.

Procedure

On the PCU LocalWS, check the cell status.




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NOTE


l If the cell status is Internal fault, do as follows:

1. On the PCU LocalWS, check the CGI of the cell.2. On the BSC6000 Local Maintenance Terminal, check the MCC, MNC, LAC, and

CI. For detailed operations, refer to Step 1 of 8.2.2 Troubleshooting DataConfiguration Faults.

NOTE

The CI can be displayed in decimal or hexadecimal mode. Set the Cell LAC&CI&RA displaymode to Decimal or Hexadecimal. For detailed operations, refer to Setting Attributes of theBSC6000 Local Maintenance Terminal. The LAC and CI in the CGI are displayed inhexadecimal mode.

3. Check whether the CGI on the PCU side is consistent with that on the BSC side.– In consistent, end the troubleshooting.

– If inconsistent, modify the CGI on the PCU LocalWS or BSC6000 LocalMaintenance Terminal.

l If the cell status is Dependency, do as follows:Select PBSL from the LAPD Link No. Scope area to check the status of the PBSL on theBSC side. For detailed operations, refer to Maintaining LAPD Links.If the State of the PBSL is Failure, rectify the fault by referring to 9.2.5 TroubleshootingLAPD Link Faults (External PCU).

l If the cell status is Device has not been initialized, do as follows:

1. On the BSC side, check the status of the TRXs configured for the cell.

a. On the Management Tree tab page of the BSC6000 Local MaintenanceTerminal, select a TRX. Then, check the related information on the Site DevicePanel, as shown in Figure 9-2.



9-15

Figure 9-2 Site device panel

b. Check the TRX status, as show in Figure 9-2.– If abnormal, reset or replace the TRX board.

– If normal, go to 1.2.

2. On the BSC side, view the channel type of each TRX timeslot to check whether thePDCH is configured for the cell. For detailed operations, refer to 1.2.

3. On the PCU LocalWS, run a cell reset command to check whether the cell is restored.If not, refer to 9.2.3 Troubleshooting Cell Kickoff Failures (External PCU).

l If the cell status is Cell does not support GPRS, do as follows:Operate according to 9.2.1 Troubleshooting a Cell Not Supporting GPRS.

l If the cell status is Cell does not exist, do as follows:On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, clickthe cell and check the cell attributes. If the cell status is Not Activated, change it toActivated.

l If the cell status is Cell database configuration error, do as follows:

1. Modify the GPRS cell data according to the error prompts on the PCU LocalWS.2. On the BSC6000 Local Maintenance Terminal, check the channel type of each TRX

timeslot configured for the cell.

a. On the Management Tree tab page of the BSC6000 Local MaintenanceTerminal, click the cell and check the cell attributes.

b. Select a TRX in the Assigned TRXs area, and then click TRX Config.




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c. On the Channel Attributes tab page, click Channel No. 0 to 7 in turn to checkall the channel types of the current TRX in Channel Type drop-down list, asshown in Figure 9-3.

Figure 9-3 Channel attributes

3. Check whether the PBCCH is configured on the BSC side but not configured on thePCU side. If the configurations are inconsistent on the two sides, modify theparameters to keep them consistent.

l If the BSC administrative status of the cell is BLOCKED, do as follows:

1. On the BSC6000 Local Maintenance Terminal, check the status of the site and cellto ensure that the cell is operational. For detailed operations, refer to Querying BTSRunning Status.

2. If the cell is operational, block the cell and then unblock the cell to check the cell statuson the PCU side.

3. On the PCU LocalWS, run the cell reset command, trace the messages on the Pbinterface, and then operate according to 9.2.3 Troubleshooting Cell Kickoff Failures(External PCU).

----End

9.2.3 Troubleshooting Cell Kickoff Failures (External PCU)This describes the cell kickoff procedure and the troubleshooting methods in the case that thePCU is configured outside the BSC.

ContextFigure 9-4 shows the GPRS cell kickoff procedure.



9-17

Figure 9-4 GPRS cell kickoff procedure

PCU_BSC_CELL_RESET

BSC_PCU_CELL_RESET_ACK

PCU_BSC_CELL_CONFIG_REQ

BSC_PCU_CELL_INFO

PCU_BSC_CELL_INFO_CNF

BSC_PCU_CHAN_INFO

PCU_BSC_CHAN_INFO_CNF...

PCU_BSC_CHAN_INFO_CNF

BSC_PCU_CELL_CONFIG_ACK...

BSC_PCU_CHAN_INFO

PCU_BSC_PDCH_REQ

BSC_PCU_PDCH_ACK...

PCU_BSC_PDCH_REQ

BSC_PCU_PDCH_ACK

BSC PCU

The GPRS cell kickoff procedure is described as follows:

1. The PCU initializes the cell and sends a PCU_BSC_CELL_RESET message to the BSCon the Pb interface.

2. After the PCU receives a BSC_PCU_CELL_RESET_ACK message from the BSC, thePCU sends a PCU_BSC_CELL_CONFIG_REQ message to the BSC, requesting theconfiguration information of the cell.

3. The BSC sends a BSC_PCU_CELL_INFO message and multipleBSC_PCU_CHAN_INFO messages to the PCU. The PCU responds with aPCU_BSC_CELL_INFO_CNF message and PCU_BSC_CHAN_INFO_CNF messagesrespectively. After the BSC sends such a message to the PCU, it waits for the responsefrom the PCU. The BSC sends another message to the PCU only after it receives theconfirmation message from the PCU.




Issue 01 (2008-06-10)

4. After the BSC receives all the confirmation messages from the PCU, the BSC sends aBSC_PCU_CELL_CONFIG_ACK message to the PCU, indicating that it has received allthe configuration information of the cell.

5. The PCU sends PCU_BSC_PDCH_REQ messages to the BSC on the Pb interface. TheBSC responds with BSC_PCU_PDCH_ACK messages. These channel request andacknowledgment messages are processed concurrently.

During the cell kickoff procedure, if the response to a message is timeout, this message is sentout again. If still timeout after multiple retransmissions, the system takes different measures indifferent cases:

l BSC_PCU_CELL_RESET_ACK timeoutIn this case, the PCU fails to initialize the cell. It then initializes other cells if necessaryand after that initializes this cell again.

l BSC_PCU_CELL_CONFIG_ACK timeoutIn this case, the PCU fails to initialize the cell. It then initializes other cells if necessaryand after that initializes this cell again.

l Other responses timeoutGo to Step 1 to implement cell initialization.

During the cell kickoff procedure, if an NACK message is received, the system take differentmeasures in different cases:

l After sending a PCU_BSC_CELL_CONFIG_REQ message to the BSC, the PCU mayreceive a BSC_PCU_CELL_CONFIG_NACK message from the BSC. The cause may bethat the cell does not exist, the cell does not support GPRS, the BSC is resetting the cell,or others.– If the cell does not exist or the cell does not support GPRS, the PCU does not initialize

the cell any longer.– If the BSC is resetting the cell or the initialization is caused by other reasons, the PCU

initializes other cells and then this cell again.l After sending a PCU_BSC_PDCH_REQ message from to the BSC, the PCU may receive

a BSC_PCU_PDCH_REQ_NACK message from the BSC. Go to Step 1 to implement cellinitialization.

Procedure

Step 1 On the PCU LocalWS, start Pb interface tracing and run a cell reset command.

Step 2 After sending a PCU_BSC_CELL_CONFIG_REQ message to the BSC, the PCU may receivea BSC_PCU_CELL_CONFIG_NACK message from the BSC. For different causes, usedifferent troubleshooting methods, as shown in Table 9-6.



9-19

Table 9-6 Cell kickoff troubleshooting methods

Cause Troubleshooting Method

The cell does not exist. 1. On the BSC6000 Local MaintenanceTerminal, check whether the cell exists.l If the cell does not exist, go to 2.2.

l If the cell exists, go to 2.3.

2. Add the cell on the BSC6000 LocalMaintenance Terminal, or delete the cellon the PCU LocalWS. For detailedoperations, refer to Adding a BTS (TDMTransmission Mode) or 9.2.9Commands Executed on the PCUMaintenance Terminal respectively.

3. If the fault persists, contact the HuaweiCustomer Service Center by referring to1.3.1 Obtaining Technical Support.

The cell does not support GPRS. Refer to 9.2.1 Troubleshooting a Cell NotSupporting GPRS.

The BSC is resetting the cell. After the BSC resets the cell, run the cell resetcommand again on the PCU LocalWS.

----End

9.2.4 Troubleshooting PDCH Faults (External PCU)This describes how to troubleshoot a PDCH in a malfunctioning state on the external PCU side.

Fault Symptomsl The PDCH status is Device has not been initialized or Blocked.

l The BSC administrative status of the PDCH is Blocked.

ProcedureOn the PCU LocalWS, check the cell status on the PCU side.

NOTE

For the PCU commands, refer to 9.2.9 Commands Executed on the PCU Maintenance Terminal.

l If the PDCH status is Device has not been initialized, do as follows:

1. On the BSC6000 Local Maintenance Terminal, check the status of the BTS and cellwhere the PDCH is located. For detailed operations, refer to Querying BTS RunningStatus.

2. On the PCU LocalWS, check the circuit status of the Pb interface by referring to 9.2.9Commands Executed on the PCU Maintenance Terminal.– If the circuit status is Uninstalled, check whether the circuit configuration of the

Pb interface on the BSC side is consistent with that on the PCU side. If inconsistent,




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modify the data configuration by referring to Configuring the Pb Interface E1/T1.

– If the circuit status is Faulty, check whether the circuit connection is consistentwith the data configuration and whether the circuit connection is correct. Aftercorrecting the connection, unblock the circuit on the Pb interface by referring toUnblock Pb Interface CIC(UBL PBCIC).

– If the circuit on the Pb interface still malfunctions, contact the Huawei CustomerService Center by referring to 1.3.1 Obtaining Technical Support.

3. On the BSC6000 Local Maintenance Terminal, check for idle timeslots on the Abisinterface by referring to Querying the Status of the Abis Interface Timeslot.– If there is an idle timeslot in the UNINSTALLED state, check the configuration

of the idle timeslot on the BSC side of the Abis interface.– If there is an idle timeslot in the FAILURE state, check whether the circuit

connection on the Abis interface is consistent with the data configuration.– Correct the circuit connection. If the idle timeslot on the Abis interface is still in

an abnormal state, contact the Huawei Customer Service Center by referring to1.3.1 Obtaining Technical Support.

4. On the BSC6000 Local Maintenance Terminal, trace the messages on the Pbinterface by referring to Tracing the Messages on the Pb Interface.If many PDCH requests are rejected because no PDCH is available, add PDCHs tothe cell.

l If the BSC administrative status of the PDCH is Blocked, do as follows:

1. On the BSC6000 Local Maintenance Terminal, check the channel status by referringto Monitoring Channel Status.If the channel is in an abnormal state, block the channel and then unblock it. Fordetailed operations, refer to Modifying BTS Administrative State.

2. Check the channel status on the PCU side. If the channel status is still Blocked, contactthe Huawei Customer Service Center by referring to 1.3.1 Obtaining TechnicalSupport.

l If the PDCH is in any other abnormal state, contact the Huawei Customer Service Centerby referring to 1.3.1 Obtaining Technical Support.

----End

9.2.5 Troubleshooting LAPD Link Faults (External PCU)This describes how to troubleshoot LAPD link faults, because of which the MS cannot performPS services.

Fault SymptomsAn LAPD link is in a faulty state, which you can check on the BSC6000 Local MaintenanceTerminal. The LAPD link is in the DISABLED state, which you can check on the PCULocalWS.

Possible CausesThe possible cause of LAPD link malfunctions is circuit insufficiency on the Pb interface. Circuitinsufficiency is further caused by the following reasons:



9-21

l The circuits on the Pb interface are too few.

l Some circuits on the Pb interface are blocked or faulty.

NOTE


Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, check the status of the E1/T1 port.1. Loop back the E1/T1 port of the LAPD link and then check the loopback status. For detailed

operations, refer to Looping Back the Interface Board Port. If the E1/T1 port is inloopback mode, click stop to stop the loopback.

2. Loop back the E1/T1 timeslot of the LAPD link and then check the loopback status. Fordetailed operations, refer to Looping Back the Interface Board Port Timeslot. If thetimeslot is in loopback mode, click stop to stop the loopback.

3. Check the status of the LAPD link by referring to Maintaining LAPD Links. Check thestatus of the LAPD link. If it is not restored, check whether the data configuration of theLAPD link is consistent with the E1/T1 physical connection.l If inconsistent, modify the data configuration.


Step 2 On the PCU LocalWS, check the status of the LAPD link.

If the administrative status of the LAPD link is BLOCKED, unblock the LAPD link.

l If the administrative status of the LAPD link is ENABLED, end the troubleshooting.

l If the administrative status of the LAPD link is still abnormal, go to Step 3.

Step 3 On the PCU LocalWS, check the status of the port of the LAPD link.

If the port of the LAPD link is in local or remote loopback, stop the loopback.

l If the administrative status of the LAPD link is ENABLED, end the troubleshooting.

l If the administrative status of the LAPD link is still abnormal, go to Step 4.

Step 4 Perform a loopback test on the E1/T1 lines that carry the LAPD link. This test does not affectthe data services on other E1/T1 lines connected to the L2PU/HLPU or the signaling on theLAPD link. The specific operations are as follows:1. On the BSC side, connect the RX end and the TX end of the E1/T1 lines that carry the

LAPD link.2. On the PCU LocalWS, run the E1/T1 loopback command.3. Check the loopback status of the E1/T1 lines and the status of the LAPD link.

l If the E1/T1 loopback test succeeds, the status of the LAPD link is ENABLED, which canbe checked on the PCU LocalWS. On the BSC6000 Local Maintenance Terminal, checkwhether the configuration of the LAPD link on the BSC side is consistent with that on thePCU side. For detailed operations, refer to Maintaining LAPD Links. If inconsistent,modify the data. If the fault persists, go to Step 5.

l If the status of the LAPD link is still DISABLED on the PCU LocalWS, then, on the PCUside, connect the RX end and the TX end of the E1/T1 lines that carry the LAPD link. If




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the E1/T1 loopback test succeeds, you can infer that the E1/T1 lines that carry the LAPDlink are faulty. Replace the E1/T1 cable. If the E1/T1 loopback test fails, go to Step 5.

Step 5 On the PCU LocalWS, perform a loopback test on the board that carries the LAPD link.

CAUTIONThis test is performed on all the LAPD links carried on the two L2PUs of the RPPU. Therefore,the test disrupts the transmission of all traffic and signaling.

Perform the loopback test by running the command mt transRPPUNo 04 2 1 LoopMode.

NOTE

l RPPUNo: number of the board that carries the LAPD link

l LoopMode: loopback mode. The value range is as follows:

l 0: no loopback

l 1: loopback from the LAPD module

l 2: loopback from the CPM on chip 860

l 4: loopback from the E1/T1 controlling chip on the L2PU

l 5: loopback by connecting the RX end and the TX end at the E1/T1 port. This loopback modefunctions like the mt lapd loop set command.

Based on the result of LAPD link loopback, take one of the following measures:

l If the loopback test succeeds in LoopMode 1, 2, 4, or 5, the status of the LAPD link isENABLED, which you can check on the PCU LocalWS. Check whether the configurationof the LAPD link on the BSC side is consistent with that on the PCU side.

l If the loopback test succeeds in LoopMode 1, 2, or 4 but fails in LoopMode 5, you can inferthat the external port for the E1/T1 cable that carries the LAPD link may be faulty and youneed to replace the board.

l If the loopback test fails in LoopMode 1, you can infer that the LAPD module software maybe incorrect and you need to contact Huawei for technical support. If the loopback testsucceeds in LoopMode 1, you can infer that the hardware of the L2PU that carries the LAPDlink may be faulty and you need to replace the board.

Step 6 On the PCU LocalWS, check whether the timeslot configured for the LAPD link is consistentwith that on the BSC side.

Step 7 On the BSC side and the PCU side, separately check whether the E1/T1 physical connection ofthe LAPD link is consistent with the data configuration.

----End

9.2.6 Troubleshooting Cell Activity State Faults (Built-in PCU)This describes how to troubleshoot the cell activity state faults. You can query on the LocalMaintenance Terminal that the activity state of a single cell is abnormal.

Possible CausesThe possible causes of the cell activity state faults are as follows:



9-23

l The cell cannot kick off normally or the cell distribution fails.

l The Um interface or the Gb interface is blocked.

Procedure

Step 1 On the Local Maintenance Terminal, run the DSP PSCELL command to verify the state ofa specified cell.

If the cell is inactivated, modify the cell state as follows:

1. On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, right-click the cell and then select Configure Cell Attributes from the shortcut menu.

2. In the displayed dialog box, double-click the target cell in the Cell view list box to add itto the Selected cells list box. Then, click Next.

3. In the Cells to be set list box, select the target cell, and then click Set Cell Properties. Adialog box is displayed, as shown in Figure 9-5.

Change the Activity State from Activated to Inactivated.




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Figure 9-5 Set Cell Attributes dialog box

l If the fault is rectified, end the troubleshooting.l If the fault persists, the DSP of the cell is blocked or is being initialized and so you can go

to Step 2.

Step 2 On the Local Maintenance Terminal, run the DSPSTAT command to verify the DSP state.

If the DSP is inoperable or faulty, block the DSP by referring to Unblock DSP(UBL DSP), orredistribute the GPRS cells on the DSP by referring to Set PS Cell Distribution on DSP(SETPSCELLTODSP).


Step 3 On the Local Maintenance Terminal, run the DSP PSRES command to verify the cell Umadministration state.

If the cell Um administration state is blocked, check whether the TRXs under this cell is innormal state. Set the cell Um administration state to unblocked by referring to 7.2.3Troubleshooting TRX Faults.



9-25

l If the fault is rectified, end the troubleshooting.

l If the fault persists, go to Step 4.

Step 4 On the Local Maintenance Terminal, run the DSP PSRES command to verify the cell Gbadministration state.

According to different transmission modes between the BSC and the SGSN, perform differentoperations:

l Gb over FR

1. On the BSC6000 Local Maintenance Terminal, view the alarm information andcheck whether the alarm 331 NSVC Faulty exists.– If existent, troubleshoot the fault according to the alarm help.

– If not existent, go to 4.2.

2. On the Local Maintenance Terminal, run the DSP NSVC command to verify theNSVC state.– If the NSVC is blocked, unblock it by referring to Unblock NSVC(UBL

NSVC).– If the NSVC is unblocked, go to 4.3.

3. On the Local Maintenance Terminal, run the DSP BC command to verify the BCservice state.

– If the BC service is unavailable, reconfigure it by referring to Maintaining theBC.

– If the BC service is available, go to 4.4.

4. On the Local Maintenance Terminal, run the DSP NSVC command to verifywhether the NSVC configuration is consistent between the BSC side and the SGSNside.

– If the configuration is inconsistent, reconfigure the NSE and NSVC on the BSCside to keep them consistent with those on the SGSN side. For details, refer toConfiguring the NSE and Configuring the NSVC.

– If the configuration is consistent, go to Step 5.

l Gb over IP

1. On the BSC6000 Local Maintenance Terminal, view the alarm information andcheck whether the alarm 332 NSVL Faulty exists.

– If existent, troubleshoot the fault according to the alarm help.

– If not existent, go to the next step.

2. Check whether the IP network from the BSC to the SGSN runs normally.

– If the IP network runs abnormally, check and modify the network by referring to4.2 Link Troubleshooting Methods.

– If the IP network runs normally, go to the next step.

3. On the Local Maintenance Terminal, run the DSP NSVL command to verifywhether the NSVL configuration is consistent between the BSC side and the SGSNside.

– If the configuration is inconsistent, reconfigure the NSE and NSVL on the BSCside to keep them consistent with those on the SGSN side. For details, refer to




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Configuring the NSE, Configuring the Local NSVL, and Configuring theRemote NSVL.

– If the configuration is consistent, go to Step 5.

Step 5 On the Local Maintenance Terminal, run the DSP PTPBVC command to verify the PTP BVCstate.l If the PTP BVC administration state is blocked, unblock the PTP BVC by referring to

Unblock PTPBVC(UBL PTPBVC).l If the PTP BVC administration state is unblocked but the fault persists, contact the Huawei

Customer Service Center by referring to 1.3.1 Obtaining Technical Support.

----End

9.2.7 Troubleshooting Cell Service Disruption Faults (Built-in PCU)This describes how to troubleshoot the faults caused by cell service disruption. When the faultsoccur, the MSs in the cell fail to access the network or cannot run the PS services after access.

Possible CausesThe possible causes of cell service disruption faults are as follows:

l The MS is faulty.

l The data configuration is improper.

l The cell does not work normally.

Procedure

Step 1 Check whether the MS or its SIM card is faulty.l If faulty, modify or replace the MS or SIM card.l If normal, go to Step 2.

Step 2 On the BSC6000 Local Maintenance Terminal, check whether GPRS Support in the basicattribute parameters is selected.l If it is not selected, set the parameter to enable the MS to run the PS services in the cell.l If it is selected, go to Step 3.

Step 3 On the Local Maintenance Terminal, run the DSP PSCELL command to verify whether thecell is in normal state.l If abnormal, rectify the fault by referring to 9.2.6 Troubleshooting Cell Activity State

Faults (Built-in PCU).l If normal, go to Step 4.

Step 4 On the BSC6000 Local Maintenance Terminal, check the MCC, MNC, LAC, and CI.l If the parameters are configured incorrectly, refer to 8.2.2 Troubleshooting Data

Configuration Faults to rectify the fault.l If the parameters are configured correctly, go to Step 5.

Step 5 On the Local Maintenance Terminal, run the DSP PSRES command to verify the channelstatus.



9-27

l If the channel is unavailable, check the status of the LAPD link on the BSC6000 LocalMaintenance Terminal; if the OML or RSL is faulty, refer to 4.2 Link TroubleshootingMethods to rectify the fault.

l If the channel is available, go to Step 6.

Step 6 On the BSC6000 Local Maintenance Terminal, trace the Gb interface SIG and PTP messages.For details, refer to Tracing SIG Messages on the Gb Interface and Tracing PTP Messageson the Gb Interface.

After the MS is switched on, check whether the MS ATTACH and PDP Activation messagesare traced. According the reported information, determine the fault type and rectify the fault.


Step 7 On BSC6000 Local Maintenance Terminal, trace the Um interface message. For details, referto Tracing PS Domain Messages on the Um Interface.

Check the uplink and downlink messages on the Um interface, and analyze data transmission,packet assignment, MS access, and immediate assignment to decide whether they are in normalstate. According to the reported information, determine the fault type and rectify the fault.

l If the fault is rectified, end the troubleshooting.l If the fault persists, contact the Huawei Customer Service Center by referring to 1.3.1


----End

9.2.8 Troubleshooting Global Service Disruption Faults (Built-inPCU)

This describes how to troubleshoot the faults that disrupt the services globally. When the faultsoccur, all the MSs in the service area of the PCU fail to access the network and cannot run dataservices.

Possible CausesThe possible causes of global service disruption are as follows:

l The equipment is faulty.

l A transmission fault occurs.

l The data configuration is incorrect.

l The software program works abnormally.

ProcedureStep 1 Check whether the equipment is faulty.

1. Check and rectify the fault in power supply.

a. Check whether the power supply LED of the BSC power distribution box is in thenormal status.l If the LED is abnormal, check whether the -48 V DC power cabinet works properly

and whether the power cables are securely connected to the -48V1 and -48V2wiring terminals on the power distribution box.




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WARNINGBe careful when checking the power cabinet and power cables. Misoperations aredangerous.

l If normal, go to 1.1.b.

b. Check whether all subracks and LAN switches are powered normally.l If abnormal, check whether the power switches of the subracks or LAN switches

are set to off, and whether the power input connectors on the subracks and LANswitches and the -48 V power output connectors on the power distribution box arein good contact.

l If normal, go to Step 2.

Step 2 Check and rectify the fault in boards.

On the BSC6000 Local Maintenance Terminal, view the alarm information to check whetherthere are hareware-related alarms. On the Device Panel, check whether the hardware is faulty.To troubleshoot the fault, refer to 9.1.2 Alarms Related to PS Service Faults.


Step 3 Check and rectify the fault in transmission.

Check the ports that connect the BSC and the SGSN or BTS, and check whether the trunk cableis securely connected to the port on the board.

l If a transmission fault is diagnosed, contact the transmission equipment maintenanceengineer to check and rectify the fault.

l If the fault persists, go to Step 4.

Step 4 Check whether the data configuration is incorrect.

The data configuration error occurs in the following cases:

l Incorrect data modification– Misoperations may cause incorrect data modification.

In such an unexpected case, you can only check the data configuration and correct theerrors if any.

– Improper data modificationIt can be anticipated that you modify the data as required but your modification isimproper. In such a case, you should back up the data before modification and restore thebackup data whenever your data modification goes wrong.

l Inconsistent data configurationIf the data is configured correctly on the BSC side, check whether the data is consistent withthat on the SGSN side. If inconsistent, modify the data configuration on the SGSN side.

Based on the previous situations, troubleshoot the fault as follows:




9-29

Step 5 Check whether the software program works normally on both BSC and SGSN sides.

On the BSC6000 Local Maintenance Terminal, trace the Um and Gb interface messages anddecide whether the software program is abnormal. For details, see Step 6 and Step 7 describedin 9.2.7 Troubleshooting Cell Service Disruption Faults (Built-in PCU).

l If the fault is rectified, end the troubleshooting.

l If the fault persists, contact the Huawei Customer Service Center by referring to 1.3.1Obtaining Technical Support.

----End

9.2.9 Commands Executed on the PCU Maintenance TerminalThis describes the commands frequently used on the PCU maintenance terminal duringtroubleshooting.

Table 9-7 lists the commands frequently used on the PCU maintenance terminal.

NOTE

Each PCU MML command consists of keywords and optional parameters. The format of parameters isdefined as follows:

l < >: indicates mandatory items. The items in the angle brackets cannot be omitted when you enter acommand.

l [ ] : indicates optional items. The items in the brackets can be omitted when you enter a command.

l | : The parameter on only one side of this symbol must be entered.

l { }: All the parameters in the brackets must be entered or omitted as a whole.

Table 9-7 Commands executed on the PCU maintenance terminal

Function Command

Checking the status of cells on the PCUside

mt gcell show state{<BoardNo>all}|<LCNo>|<LCName>|<CGI>

Querying the cell attributes mt gcell show attr{<BoardNo>all}|<LCNo>|<LCName>|<CGI>

Resetting the cells mt gcell show reset{<BoardNo>all}|<LCNo>|<LCName>|<CGI>

Checking the cell configurations pcu check cellconfig{<LCNo1><LCNo2>...}|all

Checking the status of PDCHs mt pdch show state{<LCNo>|<LCName>|<CGI>}{<PdchNo>|all}

Checking the status of LAPD links mt lapd show state{<BoardNo>all}|<LapdNo>|<LapdName>

Unblocking the LAPD links mt lapd unblock{<BoardNo>all}|<LapdNo>|<LapdName>

Checking the status of the E1 portscorresponding to the LAPD links

mt lapd port show state<BoardNo><L2PUNo>




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Function Command

Setting the loopback status of the E1 ports mt lapd port loopset<BoardNo><PortNo><LoopMode>LoopMode is of three types:l NoLoop: no loopback and normal working

model LoopBack: local loopback

l REchoOff: remote loopback

Setting the loopback status of the LAPDlinks

mt lapd port loop set{<LapdNo>|<LapdName>}<LoopMode>LoopMode is of two types:l NoLoop: no loopback and normal working

model FromE1Line: loopback of the E1 cable. You

need to connect the transmitting end and thereceiving end of the E1 cable.

Checking the configurations of the E1ports

pcu check e1config

Deleting the cells pcu del allofonecell<LCNo>

Checking the status of the circuits on thePb interface

mt pcic show state{<BSCNo><PcicNo>}|{<BoardNo><E1No><E1Slot>|all}

Blocking the cells mt gcell block {<BoardNo>all}|<LCNo>|<LCName>|<CGI>

Unblocking the cells mt gcell unblock {<BoardNo>all}|<LCNo>|<LCName>|<CGI>

Querying the cell attributes pcu show attr<LCNo>|all|{where<Condition>}[order by <FieldName>]

9.3 Typical Cases of Troubleshooting PS Service FaultsThis describes the typical cases of troubleshooting PS service faults.

9.3.1 Case: Intermittent LAPD LinksThis describes a typical case of troubleshooting intermittent LAPD links. When the E1 cable onthe Pb interface is faulty and the receiving (RX) end is normal but the transmitting (TX) end isabnormal, the LAPD links are intermittent. You need to replace the E1 cable.

9.3.2 Case: Broken Links on the Gb InterfaceThis describes a typical case of troubleshooting broken links on the Gb interface. When the linkson the Gb interface break down, you can check the cable connection, BC, NSVC, and dataconfiguration.

9.3.3 Case: MS GPRS Failure



9-31

This describes a typical case of troubleshooting the faults in data configuration or GPRS networkequipment. The faults may cause the MS to fail the network access.

9.3.4 Case: Unstable GPRS Download RateThis describes a typical case of troubleshooting the unstable GPRS download rate. The fault iscaused by the factors such as channel resources, coding schemes, and Gb interface flow control.

9.3.1 Case: Intermittent LAPD LinksThis describes a typical case of troubleshooting intermittent LAPD links. When the E1 cable onthe Pb interface is faulty and the receiving (RX) end is normal but the transmitting (TX) end isabnormal, the LAPD links are intermittent. You need to replace the E1 cable.

Fault SymptomsThe intermittent LAPD link fault occurs when the E1 cable on the Pb interface is faulty with itsRX end normal but TX end abnormal.

According to the LAPD protocol, the link setup is regarded as successful when the SAMB frameis received. Therefore, the LAPD link setup is successful if the RX end is normal. If the TX isabnormal, the interconnection with the peer end fails and the link is broken when the timerexpires. Therefore, if the RX end is normal but the TX end is abnormal, the LAPD links areintermittent. In addition, the alarm 20083 Remote E1/T1 Alarm (RAI) is reported.

Fault Location and Rectification1. On the PCU side, the RPPU that carries the LAPD links incurs RX and TX self-loop at its

E1 port. The LAPD links are normal, but when the E1 cable is reconnected, the LAPD linksappear intermittent.

2. On the BSC side, the E1 port that carries the LAPD links incurs RX and TX self-loop, andthe LAPD links are still intermittent.

3. After the E1 cable is replaced, the LAPD links are restored to normal.

9.3.2 Case: Broken Links on the Gb InterfaceThis describes a typical case of troubleshooting broken links on the Gb interface. When the linkson the Gb interface break down, you can check the cable connection, BC, NSVC, and dataconfiguration.

Fault SymptomsThe Gb interface is blocked and the PS service is disrupted because the Gb links are broken.

Fault Location and Rectification1. Check whether the cables and interface boards work normally or whether the connectors

are loose or aging. If so, rectify the fault.2. Check whether the data configuration is consistent between the BSC and the SGSN. The

data to be checked includes the number of the subrack configured for the bearer channel,slot number, port number, and DLCI number.

3. Check whether the BC is blocked. If so, unblock the BC. For details, refer toUnblock BC(UBL BC).




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9.3.3 Case: MS GPRS FailureThis describes a typical case of troubleshooting the faults in data configuration or GPRS networkequipment. The faults may cause the MS to fail the network access.

Fault Symptoms

After switch-on, the MS cannot access the network normally, the MS PDP fails to be activated,and the MS cannot perform data transmission.

Fault Location and Rectification1. Check and ensure that the cell is in normal state.

On the Local Maintenance Terminal, run the DSP PSCELL command to verify thekickoff state of a specified cell.

2. Check and ensure that the PDCH is in normal state.On the BSC6000 Local Maintenance Terminal, check the channel attributes and ensurethat the PDCH of the cell is in normal state. For details, refer to Check channelattributes.

3. Check whether the fault is caused by the SGSN.On the BSC6000 Local Maintenance Terminal, trace the Gb interface message. Fordetails, refer to Step 6 described in 9.2.7 Troubleshooting Cell Service Disruption Faults(Built-in PCU).Check whether the uplink message is traced after the MS is switched on. If the uplinkmessage is traced, contact the SGSN maintenance engineer to handle the SGSN equipment.

4. On the BSC6000 Local Maintenance Terminal, trace the Um interface and Gb interfacemessages. For details, refer to Step 6 and Step 7 described in 9.2.7 Troubleshooting CellService Disruption Faults (Built-in PCU).Analyze the MS ATTACH, PDP activation, resource assignment, and data transmissionand check whether the regular signaling flow is normal. If the signaling flow is abnormal,solve the problem according to actual conditions.

9.3.4 Case: Unstable GPRS Download RateThis describes a typical case of troubleshooting the unstable GPRS download rate. The fault iscaused by the factors such as channel resources, coding schemes, and Gb interface flow control.

Fault Symptoms

When the MS performs GPRS data transmission, especially through the FTP, the download rateis unstable.

Fault Location and Rectification1. The Th and Tc in the NS and BSSGP parameters are set to the default values and therefore

the two parameters are inconsistent with the configuration on the SGSN side. The datainconsistency affects the Gb flow control mechanism, thus decreasing the GPRS rate.

2. When the built-in PCU is used and the BS and SGSN are interconnected, the Gb parametersshould be set consistently between the two sides.



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On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, right-click BSC6000 and select Configure BSC Attributes. On the displayed dialog box, selectthe NS and BSSGP tab page, as shown in Figure 9-6.

Figure 9-6 NS and BSSGP tab page




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10 Cell Broadcast Faults

About This Chapter

This describes cell broadcast faults in terms of the symptoms, troubleshooting methods, andtypical cases.

10.1 Cell Broadcast Fault SymptomsThis describes the impacts of cell broadcast faults on services, possible alarms, and involvedperformance counters.

10.2 Cell Broadcast Troubleshooting MethodsThis describes how to troubleshoot cell broadcast faults. Basically, when a cell broadcast faultoccurs, first deal with the reported alarm, then determine the subclass of the fault, and finallyrectify the fault.

10.3 Typical Cases of Troubleshooting Cell Broadcast Service FaultsThis describes the typical cases of troubleshooting cell broadcast service faults.

HUAWEI BSC6000 Base Station SubsystemBSS Troubleshooting Guide 10 Cell Broadcast Faults


10-1

10.1 Cell Broadcast Fault SymptomsThis describes the impacts of cell broadcast faults on services, possible alarms, and involvedperformance counters.

10.1.1 Impacts of Cell Broadcast Faults on ServicesThis describes the impacts of cell broadcast faults on services.

10.1.2 Alarms Related to Cell Broadcast Service FaultsThis describes the alarms related to cell broadcast service faults. The alarms help locate andrectify the faults.

10.1.3 Counters Related to Cell Broadcast Service FaultsThis describes the counters related to cell broadcast service faults. The counters help locate andrectify the faults.

10.1.1 Impacts of Cell Broadcast Faults on ServicesThis describes the impacts of cell broadcast faults on services.

The impacts of cell broadcast faults on services are as follows:

l The cell broadcast function is enabled, but the MS cannot receive cell broadcast messages.

l The CBT fails to broadcast messages. In this case, a Failed to submit message is displayed.

l The simple cell broadcast function is enabled, but the MS cannot receive cell broadcastmessages.

10.1.2 Alarms Related to Cell Broadcast Service FaultsThis describes the alarms related to cell broadcast service faults. The alarms help locate andrectify the faults.

Table 10-1 lists the alarms related to cell broadcast service faults.

Table 10-1 Alarms related to cell broadcast service faults


The network connection is faulty. Forexample, the Ethernet cable is looselyconnected.

102 Disrupted Connection with the CBC

10.1.3 Counters Related to Cell Broadcast Service FaultsThis describes the counters related to cell broadcast service faults. The counters help locate andrectify the faults.

Table 10-2 lists the counters related to cell broadcast service faults.

10 Cell Broadcast FaultsHUAWEI BSC6000 Base Station Subsystem



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Table 10-2 Counters related to cell broadcast service faults

Counter Description

AL0484 Mean Capacity of BSC Message Library

L0457 WRITE-REPLACE Requests Received by BSC

L0458 KILL Requests Received by BSC

L0459 STATUS-CBCH-QUERY Requests Received by BSC

L0460 STATUS-MESSAGE-QUERY Requests Received byBSC

L0461 SET-DRX Requests Received by BSC

L0462 RESET Requests Received by BSC

L0463 REPORT Responses to WRITE-REPLACE Requests

L0464 REJECT Responses to WRITE-REPLACE Requests

L0465 REPORT Responses to KILL Requests

L0466 REJECT Responses to KILL Requests

L0467 REPORT Responses to STATUS-CBCH-QUERYRequests

L0468 REJECT Responses to STATUS-CBCH-QUERYRequests

L0469 REPORT Responses to STATUS-MESSAGE-QUERY Requests

L0470 REJECT Responses to STATUS-MESSAGE-QUERYRequests

L0471 REPORT Responses to SET-DRX Requests

L0472 REJECT Responses to SET-DRX Requests

L0473 RESTART-INDICATION Requests Sent from BSC

L0474 REJECT Responses to RESTART-INDICATIONRequests

L0475 FAILURE-INDICATION Requests Sent from BSC

L0476 CBCH Loading Indications Received by BSC(Overflow)

L0477 CBCH Loading Indications Received by BSC(Overflow)

L0478 WRITE-REPLACE Requests (WRITE Requests)Received by BSC



10-3

Counter Description

L0479 REPORT Responses to WRITE-REPLACE Requests(WRITE Requests)

L0480 REJECT Responses to WRITE-REPLACE Requests(WRITE Requests)

L0481 WRITE-REPLACE Requests (REPLACE Requests)Received by BSC

L0482 REPORT Responses to WRITE-REPLACE Requests(REPLACE Requests)

L0483 REJECT Responses to WRITE-REPLACE Requests(REPLACE Requests)

L0486 Disruptions of the BSC-CBC Connection

L0490 Number of Sent Broadcast Short Messages

L0487 CBCH Message Queue Usage

L0489 Average CBCH Message Queue Usage

L0488 Maximum CBCH Message Queue Usage

10.2 Cell Broadcast Troubleshooting MethodsThis describes how to troubleshoot cell broadcast faults. Basically, when a cell broadcast faultoccurs, first deal with the reported alarm, then determine the subclass of the fault, and finallyrectify the fault.

Procedure



Table 10-3 Cell broadcast troubleshooting methods


The BSC fails to provide the cell broadcastservice.

10.2.1 Troubleshooting DisconnectionBetween the BSC and the CBC

The CBS.exe file is not running or the SQL Serveris not running properly.

10.2.2 Troubleshooting CBS StartupFailures

Messages to be broadcast cannot be successfullysent through the CBS to the BSC.

10.2.3 Troubleshooting a Failure toSubmit Cell Broadcast Messages to theBSC




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The MS cannot make calls or display the networkproperly. The possible cause is that the cellbroadcast function is disabled or the number ofthe channel for cell broadcast is incorrect.

10.2.5 Troubleshooting MessageReception Failures Caused by the MS

Messages to be broadcast are successfully sent tothe BSC through the CBT software. The MS,however, still cannot receive the cell broadcastmessages.

10.2.4 Troubleshooting Incorrect CellBroadcast Parameter Settings

The BSC cannot provide the simple cell broadcastservice, and the MS cannot receive cell broadcastmessages.

10.2.6 Troubleshooting IncorrectParameter Setting of the Simple CellBroadcast


----End

10.2.1 Troubleshooting Disconnection Between the BSC and theCBC

This describes how to troubleshoot the faults in the interface between the BSC and the cellbroadcast center (CBC). The fault symptom shows that the BSC fails to provide the cell broadcastservice.

Possible Causes

The possible causes of the disconnection between the BSC and the CBC are as follows:

l The GXPUM board is faulty.

l The IP address route is wrongly configured.

l The transmission cable is faulty.

NOTE

The peer CBC runs normally by default.

Procedure

Step 1 Check whether the GXPUM board is faulty by referring to Querying BSC BoardInformation.l If faulty, rectify the fault by referring to 10.1.2 Alarms Related to Cell Broadcast Service

Faults.l If not faulty, go to Step 2.

Step 2 Check whether the GOMU/GBAM routing is consistent with the configuration of the CBC.l If inconsistent, reconfigure the data to keep it consistent. For details, refer to Configuring

Cell Broadcast.



10-5


NOTE

Check the GOMU/GBAM routing as follows: on the BSC6000 Local Maintenance Terminal, query thefollowing Basic Data in the Configure BSC Attributes window: CBC IP, CBC Port, CB InterfaceIP, CB Port, and CB Interface Handshake.

Step 3 Check whether the transmission cable is faulty. If faulty, rectify the fault by referring to 4.2.9Troubleshooting E1/T1 Transmission Faults and 4.2.10 Troubleshooting OpticalTransmission Faults.


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10.2.2 Troubleshooting CBS Startup FailuresThis describes how to troubleshoot CBS startup failures. When the CBS fails to be started, theMS cannot receive cell broadcast messages.

Possible Causes

The possible cause of a CBS startup failure is that the CBS software is closed by mistake or theSQL Server is malfunctioning.

Procedure

Step 1 Check the running status of the CBS.

l If the CBS.exe file is not running, double-click to run it.

l If the Huawei.exe file is not running, double-click to run it.

Step 2 If neither CBS.exe nor Huawei.exe runs properly, check the cbs.log file in \iMobile\cbs\.

If the cbs.log file includes the following message:

Data source DRIVER={SQLServer};SERVER=127.0.0.1;Trusted_Connection=yes;DATABASE=iMobile:Specified SQL server not found.ConnectionOpen (CreateFile())

You can infer that an error occurs when the SQL Server is started.

Step 3 Check the running status of the SQL Server.

l Check the system tray. If the icon is displayed, you can infer that the SQL Server isrunning.

l Check the system tray. If the icon is not displayed, you can infer that the SQL Serveris not started.




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Choose Start > Programs > Microsoft SQL Server > Service Manager to start the SQLServer.

l Check the system tray. If the icon or is displayed, you can infer that the SQL Serverstops running or the running is suspended.Double-click the icon. In the displayed dialog box, choose Start > Continue (S) to startor continue to run the SQL Server. If the SQL Server fails to be started, refer to the SQLServer installation guide to reinstall it.

NOTE

If the iMobile database still fails to be opened, restart the SQL server and then run the CBS.exe file.

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10.2.3 Troubleshooting a Failure to Submit Cell Broadcast Messagesto the BSC

This describes how to troubleshoot a failure to submit cell broadcast messages from the CBS tothe BSC.

Possible CausesThe possible causes of such submit failures are as follows:

l The GXPUM on the BSC side is not running properly.

l The CBC is not configured properly on the BSC side.

l The number of cells that support short message broadcast is 0 in the license file on the BSCside, or no channel for broadcasting short messages is set up in the cells on the BSC side.

Procedure

Step 1 On the BSC Device Panel tab page of the BSC6000 Local Maintenance Terminal, checkwhether the GMPS is configured with the GXPUM and whether the GXPUM is running properly.l If the GXPUT is not configured, configure it by referring to Configuring the GXPUM

and ensure that it can run properly.l If the GXPUT is not running properly, rectify the fault by referring to Analysis of

Hardware Faults.l If the GXPUM is configured and it is running properly, go to Step 2.

Step 2 Check the global data configuration of the BSC.1. On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, right-

click BSC6000 and select Configure BSC Attributes. A dialog box is displayed, as shownin Figure 10-1.



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Figure 10-1 Configuring BSC attributes

2. On the Basic Data tab page, check whether the settings of the following parameters areconsistent with the actual configuration:l Support Cell Broadcastl CBC IPl CBC Portl CB Interface IPl CB Interface Portl CB Interface Handshake

l If inconsistent, modify the parameter settings to keep them consistent.l If consistent, go to Step 3.

Step 3 On the Local Maintenance Terminal, check the license information and check whether theparameter settings are consistent with the actual configuration. For detailed operations, refer toDisplay License Usage Information(DSP LICUSAGE).l If the number of TRXs that support short message broadcast is 0, you can infer that the cell

broadcasting function is not enabled. In this case, a new license needs to be requested.l If the number of TRXs that support short message broadcast is 0, you can infer that the cell

broadcasting function is enabled. Go to Step 4.

Step 4 Check whether the CBCH is configured for the TRX.l If the CBCH is not configured, configure it on the BSC6000 Local Maintenance

Terminal by referring to Configuring Cell Broadcast.l If the CBCH is configured, go to Step 5.


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10.2.4 Troubleshooting Incorrect Cell Broadcast Parameter SettingsThis describes how to troubleshoot incorrect parameter settings for cell broadcast. When theparameter settings are incorrect, the MS cannot receive cell broadcast messages although themessages are successfully sent to the BSC through the CBT software.

Possible Causes

The possible causes of parameter setting errors are as follows:

l The number of broadcast support cells exceeds that specified in the BSC license file.

l The cell on which the MS camps is not within the broadcast scope, or the broadcast timeis set incorrectly.

Procedure

Step 1 On the Local Maintenance Terminal, check the AUTHORIZED CBS CELL specified in theBSC license file. For detailed operations, refer to Display License Usage Information(DSPLICUSAGE).

Step 2 Check the CBT data configuration to obtain the number of broadcast support cells.

1. Select a message to be broadcast through the CBT software, as shown in Figure 10-2.

Figure 10-2 Selecting a message

2. Right-click the message, and then select Edit from the shortcut menu. A dialog box isdisplayed, as shown in Figure 10-3.



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Figure 10-3 Broadcast scope

3. On the Broadcast Scope tab page, calculate the number of selected cells.

Step 3 Compare the number of broadcast support cells specified in the BSC license file with thatspecified in the BSC data configuration.l If the number of selected cells exceeds the number of broadcast support cells specified in

the BSC license file, consult with the customer about whether to apply for a new license.l If no new license file is required, remove some cells to cause the number of cells within

the limit specified in the BSC license file.

Step 4 Check whether the cell on which the MS camps is within the broadcast scope, as shown inFigure 10-3. If the cell is not within the broadcast scope, select the cell in which the messageis to be broadcast.

Step 5 Select the broadcast tab page, as shown in Figure 10-4. Check whether the configured broadcasttime is consistent with the required one. If inconsistent, modify the start time and then submitthe message.




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Figure 10-4 Editing the message

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10.2.5 Troubleshooting Message Reception Failures Caused by theMS

This describes how to troubleshoot message reception failures caused by the MS. When such afailure occurs, the MS cannot make calls, display the MNC, or receive cell broadcast messages.

Possible CausesThe possible cause of a message reception failure caused by the MS is that the MS fails to accessthe network or the MS disables the function of receiving cell broadcast messages.

Procedure

Step 1 Check whether the MS can make calls and display the MNC.l If the MS can implement such functions, end the troubleshooting.l If the MS cannot implement such functions, go to Step 2.

Step 2 Check whether the function of receiving cell broadcast messages is enabled or whether thenumber of the channel for cell broadcast is correct.l If the function of receiving cell broadcast messages is disabled, enable it.



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l If the number of the channel for cell broadcast is wrong, correct it.l If the fault persists, contact the Huawei Customer Service Center by referring to 1.3.1


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10.2.6 Troubleshooting Incorrect Parameter Setting of the SimpleCell Broadcast

This describes how to troubleshoot the incorrect parameter setting of the simple cell broadcast.The fault symptom shows that the BSC fails to provide simple cell broadcast services and thusthe MS cannot receive the cell broadcast message.

Possible CausesThe possible causes are as follows:

l The simple cell broadcast function is not enabled on the BSC6000 Local MaintenanceTerminal or the related parameters are set incorrectly.

l The cell broadcast message is not configured on the Local Maintenance Terminal.

ProcedureOn the BSC6000 Local Maintenance Terminal, enable the simple cell broadcast function andconfigure related parameters. For details, refer to Configuring Simplified Cell Broadcast.

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10.3 Typical Cases of Troubleshooting Cell BroadcastService Faults

This describes the typical cases of troubleshooting cell broadcast service faults.

10.3.1 Case: CBT/OMT/MMT Login FailureThis describes a typical case of troubleshooting the CBT/OMT/MMT login failure. If the username on the CBT/OMT/MMT is different from that on the CBS, or if the DCOM configurationis incorrect, the login to the CBT/OMT/MMT fails.

10.3.1 Case: CBT/OMT/MMT Login FailureThis describes a typical case of troubleshooting the CBT/OMT/MMT login failure. If the username on the CBT/OMT/MMT is different from that on the CBS, or if the DCOM configurationis incorrect, the login to the CBT/OMT/MMT fails.

Fault SymptomsIf the user name on the CBT/OMT/MMT is different from that on the CBS, or if the DCOMconfiguration is incorrect, the CBT/OMT/MMT fails to connect to the server.

NOTE

Run the dcomcnfg command to check the DCOM configuration.




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Fault Location and Rectification1. Log in to the CBT/OMT/MMT as the system administrator. Create a user name that is

identical to that on the CBS.2. On the Default Properties tab page, select None from the Default Authentication

Level drop-down list.3. Log in to the CBT/OMT/MMT using the newly created user name and restart the application

programs.



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54461517 BSS Troubleshooting Guide V900R008C01 01

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