Sjzl20062310-ZXG10-BSC (V2[1].97) Maintenance Manual (Troub

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ZXG10-BSCBase Station Controller

Maintenance Manual(Troubleshooting)

Version 2.97

ZTE CORPORATIONZTE Plaza, Keji Road South,Hi-Tech Industrial Park,Nanshan District, Shenzhen,

P. R. China518057Tel: (86) 755 26771900 800-9830-9830Fax: (86) 755 26772236URL: http://support.zte.com.cn E-mail: [email protected]

http://support.zte.com.cn/

mailto:[email protected]

mailto:[email protected]

http://support.zte.com.cn/



LEGAL INFORMATION

Copyright © 2006 ZTE CORPORATION.

The contents of this document are protected by copyright laws and international treaties. Any reproduction ordistribution of this document or any portion of this document, in any form by any means, without the prior writtenconsent of ZTE CORPORATION is prohibited. Additionally, the contents of this document are protected bycontractual confidentiality obligations.

All company, brand and product names are trade or service marks, or registered trade or service marks, of ZTECORPORATION or of their respective owners.

This document is provided “as is”, and all express, implied, or statutory warranties, representations or conditions

are disclaimed, including without limitation any implied warranty of merchantability, fitness for a particular purpose,title or non-infringement. ZTE CORPORATION and its licensors shall not be liable for damages resulting from theuse of or reliance on the information contained herein.

ZTE CORPORATION or its licensors may have current or pending intellectual property rights or applications

covering the subject matter of this document. Except as expressly provided in any written license between ZTECORPORATION and its licensee, the user of this document shall not acquire any license to the subject matter

herein.

The contents of this document and all policies of ZTE CORPORATION, including without limitation policies related tosupport or training are subject to change without notice.

Revision History

Date Revision No. Serial No. Reason for Revision

12/22/2006 R1.0 sjzl20062310 First edition

01/31/2007 R1.1 sjzl20062310 Reviewed and updated



ZTE CORPORATIONValues Your Comments & Suggestions!

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Please fax to: (86) 755-26772236; or mail to Documentation R&D Department,ZTE CORPORATION, ZTE Plaza, A Wing, Keji Road South, Hi-Tech Industrial Park,Shenzhen, P. R. China 518057.

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ZXG10-BSC (V2.97) Base Station Controller Maintenance Manual (Troubleshooting)

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Contents

About this Manual........................................................... xi Purpose.............................................................................. xi Intended Audience ............................................................... xi Prerequisite Skill and Knowledge............................................ xi What is in This Manual.......................................................... xi Related Documentation........................................................xiii Conventions....................................................................... xiii How to Get in Touch............................................................xiv

Chapter 1..........................................................................1 Safety Instructions ..........................................................1

Overview.............................................................................1 Safety Symbols ....................................................................1 Toxicant ..............................................................................3 Electrical Safety....................................................................3 Antistatic .............................................................................5 Battery................................................................................ 5 Electromagnetic Radiation......................................................6 Working at Heights ...............................................................7 Fans ...................................................................................8 High Temperature.................................................................8 Plugging/Unplugging a Module ................................................8 Do Nots...............................................................................9

Chapter 2........................................................................11 Maintenance Overview ..................................................11

Common Methods ............................................................... 11 Precautions........................................................................ 13

Chapter 3........................................................................15 Analyzing and Handling OMCR Faults ...........................15



Overview .....................................................................15 Platform Faults .............................................................16

Client Startup Failure...........................................................16 Server Startup Failure..........................................................18 Abnormal Startup of an Individual Process ..............................21

Database Faults............................................................21 Database Startup Failure......................................................21 DIF Process Startup Failure...................................................25 Error Code Returned upon DIF Invocation...............................27 DIF Service Invocation Timeout.............................................28

Security Management Faults........................................... 29 User Logon Failure...............................................................29 User Right Operation Failure .................................................29 Operation Log Fault .............................................................30

Database Tool Faults ..................................................... 30 Database Monitoring Fault ....................................................30 Database Script Tool Fault....................................................31

Configuration Application Faults ......................................32 Resolution Failure of Reading Database ..................................32 Data Configuration Error ......................................................33 File Transmission Failure of Stored Software............................34

Failure of Automatic Search for Stored Software Directory.........34 Failure of Deleting Stored Software........................................35 Failure of Querying Board Version Running in Foreground..........35 Board Running Abnormal......................................................36 Failure of Observing Status Attribute in Dynamic DataManagement ......................................................................36 Failure of Observing Abis Interface Channel Status in DynamicData Management...............................................................37 Radio Resource Management Fault.........................................38

Alarm Faults.................................................................39 Real-time Alarms Report Abnormal ........................................39 Some Fields Illegible in Real-time Alarms................................39 Alarm Synchronization Failure ...............................................40 Failure of Alarm Box Displaying Audio/Visual Alarms.................41

Performance Faults .......................................................41 Failure of Creating a Performance Measurement Job.................41 Performance Report Template Not Existing..............................42 Failure of Creating a Performance Report ................................42



Signaling Tracing Faults .................................................43 Chapter 4........................................................................45 Analyzing and Handling Access Faults..........................45

Overview........................................................................... 45 Frequent Location Update .................................................... 48 Failure of MS Accessing the Network...................................... 49 Network Busy Prompted at Call ............................................. 51 Call Returned Without Prompt............................................... 52 Call Connection Time Long ................................................... 52 Called Party Not in Service Area............................................ 53 False MS Power-off.............................................................. 54 Emergency Call Failure ........................................................ 55 High Priority Subscriber Access ............................................. 55

Chapter 5........................................................................57 Analyzing and Handling Handover Faults .....................57

Overview........................................................................... 57 Handover Failure Ratio High ................................................. 58 Failure of Handover to the Best Cell....................................... 59 Handover Speed too Slow .................................................... 60

Chapter 6........................................................................63 Analyzing and Handling Congestion Faults...................63

Overview........................................................................... 63 SDCCH Congestion.............................................................. 63 TCH Congestion.................................................................. 64 A-Interface Circuit Congestion .............................................. 65

Chapter 7........................................................................67 Analyzing and Handling Call Drop Faults ......................67

Overview........................................................................... 67 Call Drop due to Poor Coverage ............................................ 69 Call Drop due to Interference................................................ 70 Call Drop due to Handover ................................................... 71 Call Drop due to Antenna Connection Error ............................. 73

Chapter 8........................................................................75 Analyzing and Handling BSC Main Processor Faults..... 75



Overview ...........................................................................75 Software Startup Fault .........................................................75 Foreground-Background Communication Fault.........................76 Indicators Abnormal ............................................................77 Active/Standby Changeover Fault ..........................................78 Active-Standby Communication Fault .....................................79

Chapter 9........................................................................81 Analyzing and Handling BSC Data and Software LoadingFaults..............................................................................81

Overview ...........................................................................81 Software Version Configuration Error......................................81 Version File not Existing .......................................................82 Version File Check Error .......................................................82 Failure of Standby MP Obtaining Data from Active MP ...............83 BTS Working Abnormally ......................................................83 A-Interface Circuit Blocked ...................................................84 Failure of Data Modification by OMCR.....................................85 BCCH Changeover Fault .......................................................86

Chapter 10......................................................................87 Analyzing and Handling A-Interface InterconnectionFaults..............................................................................87

Overview ...........................................................................87 Service Unavailable in E1 Port...............................................87 No. 7 Signaling Disconnected................................................88 No. 7 Signaling Unstable ......................................................89 SCCP Timer Matching Problem...............................................89

Chapter 11......................................................................91 Analyzing and Handling Packet Data Service Faults ....91

Overview ...........................................................................91 BVC Status Abnormal...........................................................91 PDCH Status Abnormal.........................................................92 MS ATTACH Failure..............................................................94 MS PDP Activation Failure.....................................................95 Slow Speed of MS Accessing Network.....................................96

Chapter 12......................................................................99



Analyzing and Handling Gb Interface Interconnection

Faults..............................................................................99 Overview........................................................................... 99 NSVC Disconnection.......................................................... 101 NSVC Connection Intermittent ............................................ 103 NSVC Congestion.............................................................. 104

Chapter 13....................................................................105 Analyzing and Handling Clock Faults ..........................105

Overview......................................................................... 105 Major Alarm of BSC Clock Board.......................................... 107 Minor Alarm of BSC Clock Board.......................................... 108

Chapter 14....................................................................109 Analyzing and Handling Voice Faults ..........................109

Overview......................................................................... 109 Timeslot Call Abnormal ...................................................... 110 Uplink/Downlink Voice Quality Fault..................................... 111 Voice Fault Related to ON/ OFF of DTX................................. 112 Echo Problem ................................................................... 113

Chapter 15....................................................................115

Analyzing and Handling Board Faults .........................115 Overview......................................................................... 115 BOSN Board Fault ............................................................. 116 DSNI Board Fault.............................................................. 117 GPP Board Fault................................................................ 118 DRT/EDRT Board Fault....................................................... 119 TIC Board Fault ................................................................ 119 PCM Alarm of TIC Board..................................................... 120 PUC Board Fault................................................................ 121 FRP/BRP Board Fault ......................................................... 121 Disconnected UDP Ethernet Communication of BRP................ 122 HMS Board Fault............................................................... 123 MPPP Board Fault.............................................................. 123 MTP2 Board Fault.............................................................. 124 MON Board Fault............................................................... 125 PEPD Board Fault.............................................................. 125 LapD Board Fault .............................................................. 126



MPMP Board Fault.............................................................. 126 PCOM Board Fault ............................................................. 127 COMI Board Fault .............................................................. 128 POWB Running Abnormal ................................................... 129 POWP Running Abnormal.................................................... 129 Fan Running Abnormal....................................................... 130 All PP Units Unable to Start Normally.................................... 130 Equipment Room Environment Alarms.................................. 131

Appendix A...................................................................135 Abbreviations ...............................................................135 Appendix B...................................................................139 Figures..........................................................................139 Tables...........................................................................141 Index ............................................................................143



Confidential and Proprietary Information of ZTE CORPORATION xi

About this Manual

Purpose

This manual provides procedures and guidelines that support the

troubleshooting of the ZXG10-BSC (V2.97) Base StationController.

Intended Audience

This document is intended for engineers and technicians whoperform maintenance operations of troubleshooting on theZXG10-BSC (V2.97) Base Station Controller.

Prerequisite Skill and Knowledge

To use this document effectively, users should have a generalunderstanding of wireless telecommunications technology.Familiarity with the following is helpful:

ZXG10 system and its various components

User interfaces on the Base Station Controller (BSC)

OMCR software

Local operating procedures

What is in This ManualThis manual contains the following sections:

T A B L E 1 – M A NU A L SU M M A R Y

Section Summary

Chapter 1, SafetyInstructions

Explains safety symbols and safetymeasures to observe during maintenance.

Chapter 2, MaintenanceOverview

Describes ZXG10-BSC routinemaintenance, common maintenance

methods and precautions.




xii Confidential and Proprietary Information of ZTE CORPORATION

Section Summary

Chapter 3, Analyzingand Handling OMCRFaults

Classifies OMCR faults by functionalmodule, describes common faults,analyzes their causes and provides

troubleshooting procedures.

Chapter 4, Analyzingand Handling AccessFaults

Describes methods to analyze and handleMS access faults.

Chapter 5, Analyzingand Handling HandoverFaults

Describes methods to analyze and handlehandover faults.

Chapter 6, Analyzingand HandlingCongestion Faults

Describes methods to analyze and handlecongestion faults.

Chapter 7, Analyzing

and Handling Call DropFaults

Describes call drop causes and methods tohandle them.

Chapter 8, Analyzingand Handling BSC Main

Processor Faults

Describes general procedures to handleMain Processor (MP) faults.

Chapter 9, Analyzing

and Handling BSC Dataand Software LoadingFaults

Describes general procedures to handledata and software loading faults.

Chapter 10, Analyzingand Handling A-Interface

Interconnection Faults

Describes general procedures to handlefaults in A-interface interconnection.

Chapter 11, Analyzingand Handling PacketData Service Faults

Describes methods to analyze and handlepacket data service faults.

Chapter 12, Analyzingand Handling GbInterfaceInterconnection Faults

Describes general procedures to handleGb interface interconnection faults.

Chapter 13, Analyzingand Handling Clock

Faults

Describes general procedures to handleclock faults.

Chapter 14, Analyzingand Handling VoiceFaults

Describes general procedures to handlevoice faults.

Chapter 15, Analyzingand Handling BoardFaults

Describes general procedures for handlingboard faults.

Appendix A,Abbreviations

Lists all the abbreviations used in themanual.

Appendix B, Figures andTables

Lists all the figures and tables appeared inthe manual.

Index Lists the important words appeared in the

manual.



About this Manual

Confidential and Proprietary Information of ZTE CORPORATION xiii

Related Documentation

The following documents are related to this manual:

ZXG10-BSC (V2.97) Base Station Controller DocumentationGuide

ZXG10-BSC (V2.97) Base Station Controller TechnicalManual (Fundamentals)

ZXG10-BSC (V2.97) Base Station Controller TechnicalManual (Equipment)

ZXG10-BSC (V2.97) Base Station Controller HardwareManual

ZXG10-BSC (V2.97) Base Station Controller HardwareInstallation Manual

ZXG10-BSC (V2.97) Base Station Controller DebuggingManual

ZXG10-BSC (V2.97) Base Station Controller MaintenanceManual (Routine Maintenance)

ZXG10-BSC (V2.97) Base Station Controller MaintenanceManual (Emergency Maintenance)

ZXG10-BSS (V2.97) Base Station Subsystem Network

Management Technical Manual

ZXG10-BSS (V2.97) Base Station Subsystem Command

Manual - Volume I ZXG10-BSS (V2.97) Base Station Subsystem Command

Manual - Volume II

ZXG10-BSS (V2.97) Base Station Subsystem OperationManual

ZXG10-BSS (V2.97) Base Station Subsystem OperationManual (Configuration Management)

ZXG10-BSS (V2.97) Base Station Subsystem OperationManual (Radio Parameters)

ZXG10-BSS (V2.97) Base Station Subsystem Operation

Manual (Performance Counters) - Volume I

ZXG10-BSS (V2.97) Base Station Subsystem OperationManual (Performance Counters) - Volume II

ZXG10-BSS (V2.97) Base Station Subsystem Software

Installation Manual

Conventions

ZTE documents employ the following typographical conventions.Typographical

Conventions




xiv Confidential and Proprietary Information of ZTE CORPORATION

T A B L E 2 - T Y P O G R A P H I C A L CO NVENT I O NS

Typeface Meaning

Italics References to other Manuals and documents.

“Quotes” Links on screens.

Bold Menus, menu options, function names, inputfields, radio button names, check boxes, drop-down lists, dialog box names, window names.

CAPS Keys on the keyboard and buttons on screensand company name.

Constant width Text that you type, program code, files anddirectory names, and function names.

[ ] Optional parameters.

{ } Mandatory parameters.

| Select one of the parameters that are delimitedby it.

Note: Provides additional information about acertain topic.

Checkpoint: Indicates that a particular step needsto be checked before proceeding further.

Tip: Indicates a suggestion or hint to make thingseasier or more productive for the reader.

T A B L E 3 - MO USE O P E R A T I O N C O NVENT I O NS

Typeface Meaning

Click Refers to clicking the primary mouse button (usuallythe left mouse button) once.

Double-click Refers to quickly clicking the primary mouse button(usually the left mouse button) twice.

Right-click Refers to clicking the secondary mouse button(usually the right mouse button) once.

Drag Refers to pressing and holding a mouse button andmoving the mouse.

How to Get in Touch

The following sections provide information on how to obtainsupport for the documentation and the software.

If you have problems, questions, comments, or suggestionsregarding your product, contact us by e-mail [email protected]. You can also call our customer support

center at (86) 755 26771900 and (86) 800-9830-9830.

MouseOperationConventions

CustomerSupport



About this Manual

Confidential and Proprietary Information of ZTE CORPORATION xv

ZTE welcomes your comments and suggestions on the quality

and usefulness of this document. For further questions,comments, or suggestions on the documentation, you can

contact us by e-mail at [email protected]; or you can fax your

comments and suggestions to (86) 755 26772236. You can alsobrowse our website at http://support.zte.com.cn, which containsvarious interesting subjects like documentation, knowledge base,forum and service request.

DocumentationSupport




xvi Confidential and Proprietary Information of ZTE CORPORATION




Confidential and Proprietary Information of ZTE CORPORATION 1

C h a p t e r

1

Safety Instructions

This chapter explains the safety symbols and safety measures to

observe during maintenance.

Overview

It is important to read safety instructions before operation and

maintenance of ZXG10-BSC (V2.97) equipment. Theseinstructions are supplementary to any local safety regulations in

place. In case of any conflict, local safety regulations shallprevail.

Maintenance personnel should have preliminary knowledge

about safety operations and must have received training on ZTEequipment maintenance and operations.

Observe related equipment precautions and special safetyinstructions during maintenance, provided by ZTE.

Some important safety instructions are discussed in the chapter.ZTE shall not bear any liabilities incurred by violation ofuniversal safety operation requirements, or violation of safetystandards for designing, manufacturing and equipment usage.

Safety Symbols

Table 4 lists general safety symbols used in the manual.

T A B L E 4 -GE N E R A L S A F E TY SY M B O L S

SafetySymbol

Meaning

No smoking: Smoking is forbidden.




2 Confidential and Proprietary Information of ZTE CORPORATION

SafetySymbol

Meaning

No Flammables: No flammable materials can bestored.

No touching: Do not touch.

Universal alarm: General safety precaution.

Erosion: Beware of erosion.

Electric shock: There is a risk of electric shock.

Electrostatic: Device may be sensitive to staticelectricity.

High temperature: Surface is hot and may causepersonal injury if touched.

Microwave: Beware of strong electromagnetic field.

Laser: Beware of strong laser beam.

Universal alarm symbols comprises of four levels: Danger,Warning, Caution, and Note in descending order of criticality.

Danger: Indicates an imminently hazardous situation,which, if not avoided, could result in death or serious injury.

Limit its use to only extreme situations.

Warning: Indicates a hazardous situation, which, if not

avoided, could result in serious injuries, equipment damages orinterruption of major services.

Caution: Indicates a potentially hazardous situation, which,if not avoided, could result in moderate injuries, equipment

damages or partial service interruption.



Chapter 1 - Safety Instructions


Note: Indicates helpful information that if ignored, couldresult in minor injuries, equipment damages or partial serviceinterruption.

Every safety symbol has a text description of its safety level anda detailed description of its contents.

Toxicant

Warning: Beryllia is a toxic chemical commonly used intransistors and base stations components, such as poweramplifier circuit and hybrid combiner circuit. Do not make directcontact with these components.

Broken, ruptured or squashed beryllia components produceberyllia powder, which is extremely harmful to human skin and

mucous membrane.

Beryllia components are dangerous only when they are broken,so they need a lot of care while installing and disposing.

While disposing beryllia components, comply with localregulations of chemical or special waste disposal.

In case of any accident or any physical contact involving beryllia,rinse the wound with water and rush to a hospital for proper

treatment.

Personnel exposed to such components must have completeknowledge about precautionary measures to avoid any hazard.

Warning: Some components in base station containchemicals like hydrochloride. These components release toxic

gas when burnt.

Do not burn components to prevent toxic gas release aftercombustion. Dispose off according to the local regulations ofchemical or special waste disposal.

Electrical Safety

Warning: In high DC and AC voltage operation, usespecial purpose tools.

Danger: Direct or indirect contact with high DC or AC

voltage through any moist object may result in serious injury.

Beryllia

Hydrochloride

Tools

High Voltage





AC equipment installation must comply with the local safetyregulations.

Personnel responsible for AC equipment installation must have

proper qualification in high DC and AC power.

Do not wear a watch, chain, bracelet, ring or any otherconductive objects while working with high voltages.

Prevent moisture from entering the equipment while working ina moist environment.

Note: Never install or uninstall power cables while they arelive because when touched with a conductor may produce sparks,resulting in fire or damage to eyes.

Shut down the power supply before installing or uninstalling apower cable.

Connect cables according to the labels and instructions given ininstallation and hardware manuals.

Warning: Drilling in the cabinet without prior permission is

prohibited.

Unnecessary drilling can damage cables inside the cabinet. Themetal pieces blown due to drilling can cause short circuits in thecircuit board.

While drilling in the cabinet, wear gloves and move aside cablesin the cabinet. Protect eyes from metal pieces blowing whiledrilling.

Clean the cabinet after drilling.

Danger: Do not perform high voltage and tower operationsin thunderstorm.

Thunderstorm produces a strong electromagnetic field in theatmosphere, so avoid all tower and high voltage operations.

Take lightning protection measures by grounding the equipmentto prevent any damage.

Power Cables

Drilling

Lightning





Antistatic

Note: Static electricity produced by human body candamage sensitive components on the circuit board, such as large

integrated circuits (ICs).

Friction caused by human body is the root cause of electrostaticcharge accumulation. In dry weather, the static charge carriedby human body can be up to 30 kV and can remain in humanbody for a long time. Person carrying static charge can damagea component by touching and hence transferring the charge to

the component.

To prevent human static charge from damaging sensitive

components, wear antistatic wrist strap and ground its other endbefore touching the equipment or holding a plug board, circuitboard, IC chip etc.

To prevent accidental electric shock, serially connect theconnection cable between the wrist and grounding point with aresistor above 1 MΩ. A resistor above 1 MΩ is enough todischarge static voltage.

Check antistatic wrist strap regularly and never use a cableother than the original cable that comes along with the wriststrap.

Static-sensitive module or board should not touch the objects

that can carry static electricity. For example, friction caused bypackage bags, transfer box and transfer belt made frominsulation plastic, may cause electrostatic shock to thecomponents because they can transfer static charge from humanbody or floor.

Keep the static-sensitive module or board in anti-static bagduring storage and transportation.

Ground the test device to discharge the static charge before use.

Do not place the module or board near strong magnetic field,such as cathode-ray tube of the monitor. Keep it at least 10 cm

away.

Battery

Danger: A short-circuited battery can be harmful tohuman body. Although common batteries have low voltage, but

instant powerful current caused by short circuit can release agreat amount of energy.

Short Circuit





Prevent metal objects to short circuit the battery, for example,short circuit caused by mishandling the operation tools. If

possible, cut the battery supply before any operation.

Danger: Do not use any unsealed lead-acid battery,because the gases released by the battery may erode the

equipment or cause fire. Fix the battery and place it horizontally.

Select a ventilated place for the battery having proper fireprotection measures because a battery can release combustiblegases. To prevent high temperature due to sunshine, equip thebattery room with sun-screening curtains.

Danger: Very high temperature of the battery may causedeformation, damage or acid liquid overflow.

If the battery temperature exceeds 60º C, check acid liquidoverflow in the battery.

If acid liquid has overflowed, dispose off according to the localregulations of chemical or special waste disposal.

Danger: If acid liquid overflows, absorb and neutralize it

as soon as possible.

Take special care of the acid liquids while moving a soakedbattery. If acid liquid overflows, use NaHCO3, Na2CO3 orNa2CO3.10H2O to neutralize and absorb it.

Substances used for absorption and neutralization of acid liquidsmust conform to battery manufacturers’ instructions.

Danger: Do not replace the standard model battery with

any other model battery because it might explode.

Electromagnetic Radiation

An antenna of a device generates electromagnetic radiations.The safety requirement might not be sufficient at a place toonear to the antenna. Personnel with proper training and relevantqualifications must install and maintain the equipment.Equipment radiation design shall comply with IEEE C95.1-1991.

Harmful Gases

High

Temperature

Acid Liquids

Battery

Replacement





Warning: Operating on high intensity RF equipment canseriously affect human body.

During installation and maintenance of the antenna on a towermounted with several antennas from different operators, theremust be mutual agreement to shutdown the transmission.

Warning: During installation and servicing operationsaround the operating antenna, keep adequate distance from theantenna.

Do not unplug the transmitter output feeder connector or theantenna feeder cable connector while the transmitter isoperating.

Shut down the transmitter before unplugging the feeder cable

connector or working beside the transmitter antenna.

Working at Heights

Warning: While working at heights, prevent objects from

falling down.

Working at heights should conform to local national serviceregulation requirements, such as:

All personnel working at heights must undergo propertraining.

Prevent operation machinery and tools from falling down.

Wear helmet and safety belt as a safety precaution.

Wear cold-protection clothes in cold areas.

Check all hoisting equipment before working at heights.

Warning: Do not stay or walk under the hoisted weight.

To move, replace or dismantle heavy equipment, make sure thatappropriate facilities are available.

Personnel to perform hoisting tasks must have proper training.

Check hoisting tools and make sure they are firmly fixed onsupport frame or walls.

Check the ladder if it is in good condition for use. Do not

overweight the ladder.

HoistingWeights

Using Ladders





Before climbing on a ladder, make sure that someone is holdingit. Adopt proper safety measures when there is a tilt over 5 m, 3

m for an upright ladder or when used in dangerous operationenvironment. Expand A-type ladder, completely.

Ideally, a ladder tilt is of 75 degrees. Bottom ends of the laddershould not be slippery. Place the ladder firmly on a flat area. Donot place it over the objects that can slide or move, such ascartons and stones.

Always face the ladder while climbing it. Keep the center ofgravity within the ladder edges. Hold the ladder with one handand make sure to place both feet on the ladder. Do not climbbeyond last four steps. Ladder used to climb onto a roof shouldbe at least 1 m above the eave.

Fans

Warning: Keep fingers or body away from the running fanblades. Do not use any tool on the fan before it is powered offand fan blades stop.

When replacing parts, put screws, tools and parts in a safe place.

If they fall into the running fan, they can damage the fan orother devices.

While working with devices near the fan, keep fingers or devices

away from the fan to avoid human injury or damage to devices.

High Temperature

Warning: Surface temperature of some components is veryhigh. Do not touch it.

Plugging/Unplugging a Module

Note: Do not plug a board with force as it might bend thepins at the backplane. Insert the board along the slot.

While holding a board in hand, keep hands off the board circuits,components, connectors and wiring.





Do Nots

Note: Do not conduct internal maintenance or equipmentdebugging without prior permission.

Replacing parts or changing equipment may incur extra danger,therefore, do not replace parts or change the equipment withoutprior permission.

To ensure safety, contact ZTE in case of any problem.




C h a p t e r

2

Maintenance Overview

To ensure stable and reliable operation of the BSC equipment,

effective maintenance measures are very important.Maintenance helps to discover and solve problems in due time.

This chapter gives an overview about precautions and commonmaintenance methods applied in maintenance.

Common Methods

In maintenance, faults can be located through following differentcommon methods:

Alarm monitoring is done in the OMCR (V2) Alarm Managementand Operation Log View interfaces in the BSS Operation andMaintenance subsystem.

The Alarm Management interface allows viewing and analyzing

current alarms, alarm history and normal notifications reportedby the Network Element (NE). This ensures that networkoperation abnormities can be detected in time, and the fault canbe located, isolated and removed.

The operation log in user management allows tracing systemparameter modifications, locating the responsible terminal andoperators, and detecting faults caused by improper operations.

Analyzing the LED indicator status often helps in fault detection.LED indicators of the boards on the rack are observed to identifythe fault position.

This method requires familiarity with all LED indicators and theirrespective meanings.

This is done in the OMCR (V2) Performance Managementinterfaces of the BSS Operation and Maintenance subsystem.BSS performance and trace signaling can be managed inPerformance Management interface.

View Alarm

and OperationLogs

Indicator

Status Analysis

PerformanceAnalysis





Performance measurement tasks can be created and

performance reports can be generated, to ascertain BSSperformance indices. Analyze the information to know the load

distribution in the network, and adjust network parameters to

improve network performance.In signal tracing interfaces, trace BSS-related signaling includingsignaling of the Gb interface, check signaling flows during

commissioning and maintenance, and detect problems in thesignaling inter working.

During BSC (V2.97) maintenance, the maintenance personneluse test mobile phones, signaling analyzers, bit error analyzers,and other instruments to analyze, locate or remove faults.

When a fault occurs in a board, loosen the screws on the frontpanel, and plug and unplug the board or external connectors.This method helps in ensuring good contact, or in handlingabnormal processor problems.

Pressing cable connectors after power-off may also removefaults caused by poor contact.

Board with the possible fault is compared with another in asimilar location in the system (such as a board in the same sloton a different rack). Compare the running status, jumpers, andcable connections. The comparison indicates whether the board

is faulty.

Interchange method refers to replacing the possibly faulty board,with a spare or identical board, which runs properly in thesystem. If the fault disappears after replacement, then theoriginal board is faulty. When interchange or comparison method

is adopted, the board should be pulled out or inserted inaccording to the procedure described in Boards and Components

in ZXG10-BSC (V2.97) Base Station Controller MaintenanceManual - Troubleshooting.

When a system component is faulty, the related board or rackcan be separated, to judge whether the fault is caused by theparticular component.

This refers to fault judgment through self-test after the systemor board is powered-on again. Generally, during power-on andself-test of a board, the LED indicators will blink regularly.Blinking indicates that there is a problem in the board.

In practical operations, the above methods are integrated with

the work experience of maintenance personnel to handle faults.

Analysis Using

Tools

Plugging,Unplugging

and Pressure

Comparisonand

Interchange

Isolation

Method

Self-check

UsingExperience



Chapter 2 - Maintenance Overview


Precautions

Perform the following steps during maintenance:

Maintain normal temperature and humidity in theequipment room. Keep the surrounding tidy and clean, freefrom dust and moisture. Keep rodents or insects out of theequipment room.

Ensure that the system’s primary power is stable andreliable. Check the system grounding and lightning ground

periodically. Check the lightning protection system toensure good condition before the stormy season and after

thunderstorms.

Establish complete rules for equipment room maintenance,and standardize daily work of the maintenance personnel. A

detailed attendant’s log should be maintained to providedetailed records about system operation, version, data

change, upgrading and troubleshooting, for analysis andtroubleshooting after the fault detection. Keep a record ofthe work shifts to specify the responsibility clearly.

Every client should be installed with Norton AntiVirussoftware, and real-time detection function should be

enabled. The virus library should be updated once a week,or at least once a month. The operation and maintenancecomputers should be used for special purposes only. Usageof unauthorized disks or CDs, installation of unrelated

software, or playing games on the client terminals isprohibited.

Only one user can have the super administrator rights.Other related persons can be assigned corresponding rights

according to their work contents, to guarantee data security.Set different Network Management passwords for differentaccess rights, and keep them under strict management andchange them periodically. Network Management passwordsshould be accessible only to maintenance personnel.

Maintenance personnel should be well trained and shouldhave adequate equipment and network knowledge. During

maintenance operations, follow the instructions provided inthe relevant BSC (V2.97) manual. Before touchingequipment hardware, wear an antistatic wrist strap to avoidany accidents. Maintenance personnel should have ameticulous working attitude and professional maintenanceskills, which can be enhanced through constant learning.

Do not plug and unplug boards, change over boards, load

or change data casually, particularly the NetworkManagement database. Backup data before any changes,and make records of data modifications. Do not deletebackup data until the equipment has run properly for aspecific period (usually a week) after changing data. Even

though data is not changed, backup should be taken once a





week for occasional requirements. Databases, especially

the performance measurement and alarm database, shouldbe observed on regular basis (once every two weeks).

When there are too many occupations (beyond the

recommended OMC-R value), useless data should bedeleted to avoid the error of disk overflow.

Never block the complete BSC. If radio resources orTransCoder (TC) unit is to be blocked, unblock immediatelyafter the task is fulfilled.

Never run the signaling trace program during busy traffic,especially during daytime. The signaling trace is carried outonly in low-traffic hours with the permission of the ZTE

customer service department.

Data synchronization and modifications can be carried outat night when traffic is low. Never synchronize data at

daytime.

Prepare frequently used tools and meters such as screws(straight head and cross head), signaling testers, network

cable pliers, multi meter, AC power for maintenancepurposes, telephone line, network cables, antistatic wriststrap, insulation tape and common tool kit. Periodically testand calibrate instruments and meters to ensure theiraccuracy.

Check spare parts regularly, to maintain accurate inventoryof frequently used spare parts and their working condition.Ensure that the inventory contents are unaffected by

humidity or mould. Spare parts and articles must beseparated from defective ones replaced during maintenance,and labeled appropriately for identification purposes.Frequently used spare parts and articles must be

replenished in time when out of stock.

Keep maintenance software and documentation at the siteat designated position, to ensure that software anddocumentation are available when necessary.

Ensure that lighting in the equipment room is bright enoughfor maintenance operations.

Remove any detected faults immediately. For faults that

can not be resolved, contact the local ZTE office.

Keep the ZTE CORPORATION local telephone number andaddress at an easily identifiable place and inform allmaintenance personnel, so that ZTE can be contacted whenthere is a need. Remember to get the latest contactinformation.




C h a p t e r

3

Analyzing and HandlingOMCR Faults

This chapter classifies OMCR faults by functional module,describes common faults of each functional module, analyzes

possible causes, and provides troubleshooting procedures.

OverviewOMCR manages the entire BSS, including BSC and BTS.

OMCR allows effective configuring and managing BSS, handles

various problems that might occur during BSS operation,analyzes, measures, and adjusts BSS performance. In addition,it also provides access interface to Network Management Center(NMC).

OMCR is designed with the server/client architecture. Theapplication is implemented by server; the client application does

not have direct connection with MP of the BSC. The clientapplication only provides an interface for the operator to inputoperation instructions and view the result.

OMCR server runs on UNIX and client runs on Windows platform.Two types of database are used (Oracle and DB2) to meet the

performance requirements of the system.OMCR faults can be divided into the following categoriesaccording to their functional modules:

Platform faults

OMCR platform refers to the combination of some processesof the system.

Platform faults include the faults during the start of serverand client and some key processes.

Database faults





It includes abnormal start or running of the database,

abnormal database access, and database timeout.

Security management faults

Security management includes user management andoperation log.

User management is used to set valid users andcorresponding operation and management rights. Faults inuser management mainly concerns login and user rights.

Operation log records the login information and providessystem fault detection. Faults in the operation log mainlyconcerns query.

Database tool faults

The database tool includes database monitoring anddatabase script.

Database monitoring allows users to monitor OMCR databaseand perform data backup.

Scripts are some small tools for data backup and deletion.Script faults are mainly operation failures.

Configuration application faults

These are mainly data configuration failures.

Alarm application faults

These are mainly abnormal alarm reporting and handling.

Performance application faultsThese are mainly report creation failure or no data in thereports.

Signaling tracing faults

These are mainly failures of tracing signaling messages.

Platform Faults

Client Startup Failure

Client can not start normally.

The fault may result from one of the following causes:

Network connection between server and client isdisconnected.

Client configuration file syscfg.ini is not set correctly.

Fault Symptom

Fault Cause

Analysis



Chapter 3 - Analyzing and Handling OMCR Faults


Environment variables such as $OMCHOME and $PATH are

not set correctly.

Disk is full.

Username and password of the FTP user are not set

correctly.

FTP user directory is not set correctly.

Perform the following steps to troubleshoot the fault:

1. Check whether the network connection between client andserver is normal.

2. Check whether the client configuration file syscfg.ini is set

correctly.

Especially check the following parameter settings:

IP: Client IP address

Machine No.: Client number, within the range of 140~254

IsRemote : Whether the client is a remote client. 0: local, 1:

remote

DOMAINNUM: Number of NM domains

Server information: Machine number, IP address, alias,

and server number of the server to connect

3. Check whether environment variables are set correctly

Environment variable OMCHOME

OMCHOME should be set to the directory where client

program locates, usually C:\ZXG10-OMC .

Environment variable PATH

Paths $OMCHOME/bin and $OMCHOME/lib should be

placed in the PATH variable.

Tip: $OMCHOME refers to the path name written in the

environment variableOMCHOME

.

4. If the configuration file and environment variables arecorrect, but the main interface can not start, then:

Check whether the operating system is Windows

95/98/Me. If it is, change it to Windows NT or Windows2000.

Check if there is any virus.

5. If the main interface starts normally, but the topology treecan not be shown, perform the following steps:

Troubleshooting





Check the disk space

If the disk is full, delete some unnecessary files, for

example, .log files in bin directory can often be deleted.

If there is sufficient disk space, check the attributes ofthe files in ftpc directory (including files in the

subdirectories). If the attribute is read-only, uncheck

the attribute.

Check whether the FTP user and password in the

lmfcfg.ini file are consistent with those set in UNIX.

The default FTP user is ‘ftpuser’, with the passwordftp123.

Check the owner of the $OMCHOME/tmp/ftp directory on

the server, which should be ‘ftpuser’. The command is asfollows:

$cat /etc/passwd

6. If the problem still exists, contact the local ZTE office.

END OF STEPS

None

Server Startup Failure

The server can not start or can not start completely.


Configuration files ampcfg.ini and syscfg.ini are not

set correctly.

Environment variables $OMCHOME and $PATH are not set

correctly.

Files that share the memory are not deleted.

Fault occurs in communication between the systemprocesses.

The file system of the operating system is abnormal.

Disk is full.


1. Check whether the server configuration file is correct,

including the following items:

In ampcfg.ini file, check whether MaxModule in [MODULE]

section equals to MaxLoad in [LOAD] section.

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





In ampcfg.ini file, check whether MaxProcess in

[COMMON], [COM], [DB], and [AP] sections match theactual process list number of the section.

Whether the process map name in ampcfg.ini file

matches that in syscfg.ini file

Whether the process name in syscfg.ini file matches the

actual process name, and if the process exists

In ampcfg.ini file, check whether the value of

PsLoadTimeout in the [PARAMETER] section is too small.

2. Check whether the server environment variable settings arecorrect.

Log on the operating system as ’omc’ user and check

whether the .profile file contains following contents:

OMCHOME = /export/home/omcexport OMCHOME

LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$ORACLE_HOME/lib:$OMCHOME/lib

export LD_LIBRARY_PATH

PATH = $PATH:$OMCHOME/bin

export PATH

OMCLOCALE=CHINESE

export OMCLOCALE

3. Delete the files that share the memory, /tmp/*.S* or

/var/tmp/.SHMD/*.* .

4. Check whether database has started.

5. Check whether any process starts by using omcps.

If omcps has no result returned, restart the server. To

ensure that the system is reliable, it is recommended torestart UNIX too.

Check whether OMCR (V2) process exists by using the ps -

uomc command. View OMCR (V2) process list by using

omcps to observe whether the number of processes is

consistent with that of the processes that need to start.

Viewing the amp log file also helps to locate the problem.

Open the amp log log file created at this start and check

whether SYSTEM TURN TO NORMAL exists. If it does not

exist, it indicates that the server does not start normally.

Especially check whether the start time of the processeshaving no names is the current time.

If it is not the current time, it indicates that system isabnormal. In this case, routine operations are usually not

affected, but some timed tasks may become abnormal.Therefore, it is recommended to restart the server.





6. View the system memory utilization by using the top

command.

Command format: bash-2.02$ top -U omc

Normally, the available swap space should not be less than200 M and the maximum CPU occupation ratio of a processshould be no more than 80%.

If memory utilization is abnormal, the possible cause is thatthe server is abnormal. Wait for a period of time (10 to 30

minutes) and observe. If the condition does not improve, it isrecommended to restart the process that has a high CPUutilization ratio.

Tip: The process name displayed by the top tool is the

physical process name, while what is displayed in the omcps isthe logical process name of ZXG10-OMCR. In practice, theremay be some change, and it can be verified by viewing the

syscfg.ini file on the server.

7. Check whether any partition in the server is full by using the

df command.

Perform the following operations:

Input the df command, as follows:

bash-2.02$ df –k

View utilization ratio

If utilization ratio is 100%, it indicates that some partition isfull.

View the last column, which shows the partitions.

If the /, /tmp , /var , or /export/home partitions have full

utilization ratio, then the system will become abnormal.

If other partitions have full utilization ratio, then it willgenerate some indirect influences.

For a full partition, delete some files according to actual need.

8. Check whether Trace file of abnormal process contains the

message Can not Find AMP, I exit .

If the message exists, it indicates a serious problem in inter-

process communication of the system. Restart the UNIXserver.

END OF STEPS

NonePrecautions





Abnormal Startup of an IndividualProcess

An individual process of the server starts abnormally, forexample, the IMF process, AGT process, or DIF process.


The process itself is abnormal.

The process state machine has been killed by the AMPA.

The system communication is abnormal.


1. Use omcps tool to view the abnormal process number, shown

in the first column.

2. Use omckill –kill pid command to notify the process to

exit, and the amp process will restart the process.

For example, if DIF process is abnormal, and its pid is found

to be 10 through omcps, the corresponding command is:

omckill -kill 10 .

3. Observe running status of the process.

4. If the process can not start normally yet, check whether itsTRACE file contains AMPA Kill it or Can not Find AMP,

I exit message. If these messages exist, restart the server.

5. Check whether the database starts normally.

6. Check whether the disk is full.

END OF STEPS

None

Database Faults

Database Startup Failure

The database can not start normally.

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom






Database is already running.

Database monitor does not start (for Oracle).

Database parameters are not set correctly, which causesinsufficient resources needed for startup.

The system data file needed for the startup is corrupt.

User data file is corrupt when the database is opened.

Disk is full.

The following are troubleshooting steps for Oracle database:

1. Execute svrmgrl command to access SVRMGRL command

prompt mode of Oracle.

2. Connect to database as the ‘internal’ user.

Command format: SVRMGR>connect internal

If the database mount, database open message is

displayed on screen, it indicates that the database hasnormally started.

3. If the database does not normally start, check the returnedresult.

If system prompts that database is running, then stop thecurrent database and restart it.

If system prompts that the system data file is damaged,then reinstall the database instance.

If system prompts that user data file is damaged, make thedata file offline in the internal mode by running thefollowing command:

alter tablespace fm_space offline normal

Restart database, delete the table space and create it again.

If system prompts that system parameters are set too large,modify parameters, usually the sharing pool parameter in

file $ORACLE_HOME/dbs/initSID.ora . After the

adjustment, save and restart the database.

4. Check whether the disk is full by using command df –k.

If the disk is full, delete or move some files on the full disk toanother place. This often occurs on the disk where the datafiles reside. Move a large data file to another disk by

performing the following procedures:

Connect to the database as the ‘sys’ user by running thefollowing command:

$sqlplus sys/oracle;

Make the table space offline under sqlplus by running the

following command:

Fault CauseAnalysis

Troubleshooting





sqlplus>alter tablespace fm_space offline normal;

Copy the fm.dbf file from directory /a/b/ to directory

/c/d/ on the operating system by running the following

command:

$cp /a/b/fm.dbf /c/d/

Connect to database as the ‘sys’ user and execute thefollowing two commands under sqlplus:

sqlplus>alter tablespace fm_space renamedatafile '/a/b/fm.dbf' to '/c/d/fm.dbf';

sqlplus>alter tablespace fm_space online;

5. If the database starts normally but can not be connected,check whether the database monitor has started.

Execute the following command to start the databasemonitor:

lsnrctl start

Tip: fm.dbf data file belongs to the fm_space table space.

The related information can be obtained from v$datafile as

the Oracle ‘sys’ user.

END OF STEPS

The following are troubleshooting steps for DB2 database:

1. Execute db2start command and check whether the

database server can start normally.

2. If success is reported, it indicates that database has startedsuccessfully. Otherwise, view the returned reason and restartthe database.

3. If the database is already running, stop it and restart it byrunning the following command:

db2stop

db2stop force (If any application is connected to thedatabase, use this command to forcibly stop the database.)

4. If it reports that the database server parameters are not setcorrectly, modify relevant parameters and restart the

database by running the following command:

db2=>update dbm cfg using <key> <value>

5. If it reports that other DB2 application processes are runningupon start, forcibly stop them and restart the database byrunning the following command:

db2=>force application all





6. If database starts normally but can not be connected, check

whether it is remote connection. If it is remote connection,check whether the remote connection of database is

configured properly. To configure the remote connection,

perform the following procedures:

Tip: If the database to be accessed is the database on the

remote server rather than the database of the local instance,then it requires logging on as the instance user to implement

configuration.

i. Enter the command line mode by running the followingcommand:

db2

ii. Configure the remote node by running the following

command:

db2=>catalog tcpip node db2server remote10.61.38.1 server 50000

remote Either IP address of DB2 server or Hostname.

server Either service port number (50000 in default) or

service name like db2_omc.

iii. Configure database by running the following command:

db2=>catalog database omc as omcdb at node

db2server

omc Remote database name.

omcdb Local database alias.

iv. Check whether there are already configuration database

entries and node entries in the directory by running thefollowing command:

db2=>list database directory

db2=>list node directory

v. Test the database connection by running the following

command:db2=>connect to omcdb user omc using xxx

vi. If it fails to connect to the database, perform theappropriate procedure as below according to the specificerror:

If the following error appears:

SQL30082N Failure of attempt connecting to the

database failed, with the security reason 24 (USERNAME

AND/OR PASSWORDINVALID). SQLSTATE=08001

Confirm that the username and password are correct.






SQL30081N Communication error detected. The

communication protocol being used: "TCP/IP…

Check whether the database configuration is incorrect, forexample, incorrect database name.

The configuration commands are as follows:

db2=>uncatalog database omc

db2=>catalog database omc as omcdb at nodedb2server

Check whether the node configuration is incorrect, forexample, incorrect IP address, or incorrect Server port.

The configuration commands are as follows:

db2=>uncatalog node db2server

db2=> catalog tcpip node db2server remotedb2server server 50000 remote_instance omc


QL0332N No conversion is performed from the source

code page 1383 to the destination code page 819.

Confirm that the local code page used is 1383 by running

the following command:.

db2set DB2CODEPAGE=1383

db2 terminate

Test the connection again after modification until

connection is successfully established.

Refresh the cache of the directory to make theconfiguration take effect permanently by running thefollowing command:

db2=>quit

db2 terminate

END OF STEPS

None

DIF Process Startup Failure

The DIF process can not start normally. It automatically restartsagain and again after startup.


Database connection fails.

Precautions

Fault Symptom

Fault CauseAnalysis





Database does not start.

Database version number is not consistent with theconfiguration file, or there are multiple records in thedatabase version number table.

Processing of the service invoked by DIF is abnormal,

causing DIF to restart.

Database breaks down abnormally, causing abnormal DIFconnection to the database.


1. Check whether the connection configuration in database

configuration file dbcfg.ini is correct by running the

following command:

$sqlplus user/passwd@servicename

Where, user , passwd , and servicename shall all follow

those configured in the database configuration file.

2. If it fails to connect to database, check whether the databasehas started. Start the database if it hasn’t started.

3. If the database has started and can be connected normally,

then restart the DIF.

4. If DIF process still can not start normally, search DIF log for

words like dbversion. If there is any such word, it indicates

that the version numbers are not consistent. Check the

database version number and the configuration file number:if they are inconsistent or the database has multiple records,make modification to make them consistent.

5. If DIF restarts abnormally after startup, view DIF log to findout which service caused DIF to restart, or check whetherthere is any manual restart. If such cases exist, then check

whether there is any error code returns before the restartaccording to the log and check whether there is any CORE

file.

6. If DIF becomes abnormal some time after restart, then viewthe DIF log to see whether there is any connection failure. Ifthere is, it indicates the database has a fault and requiresrestarting the database and then restarting DIF.

END OF STEPS

None

Troubleshooting

Precautions





Error Code Returned upon DIFInvocation

An error occurs upon DIF invocation, with an error code returned.


Data are incorrect, with an error code returned.

Database table space is insufficient, with an error codereturned.

The service invoked has problems, with an error codereturned.

Database object fails, with an error code returned.

Database memory is abnormal, with an error code returned.

Database is faulty, causing an error code to be returnedupon access.


1. View the database help document for error code description

and appropriate handling procedures.

2. View the service number that returns error.

3. Analyze database invocation according to the service numberand the corresponding cause of error code.

Following are some common errors:

Insufficient table space

Failure to regularly clear the history data in database maycause insufficient table space, which often occurs after

system runs for some time.

Troubleshooting: Increase appropriate table space.

Database object failure

This fault often occurs after update completes.

Troubleshooting: Make the object in database valid. If it is apackage, compile and bind it again. If it is a view, delete itand recreate it. For details, contact the local ZTE office.

Data error

Troubleshooting: View the error data and analyze the cause,which is usually the program problem. For details, contactthe local ZTE office.

Database memory utilization problem

This problem often occurs due to too many operations with

enormous data after system runs for a long time.

Fault Symptom

Fault CauseAnalysis

Troubleshooting





Troubleshooting: Restart database.

Inappropriate database parameter settings

If parameters are set too small, the problem may occur

during operations with large amount of data.Troubleshooting: Increase parameter values of the database.

END OF STEPS

None

DIF Service Invocation Timeout

DIF service invocation is timeout and data can not be obtained.


i. The service invoked takes a long time, involving too muchdata.

4. Multiple services that take a long time are initiated at thesame time, for example, updating the performanceintermediate table.

5. The service logic processing invoked has some problem,which causes long operation time.


1. View DIF log to see whether there is any service that takes along time to access the database. If there is, restart the DIF.

2. Find the earliest service number that takes a long time, andanalyze for possible places where the service consumes sucha long time. Save the log and restart DIF.

3. View DIF log to see whether there are multiple services

initiated at the same time that take a long time. If there are,restart database and DIF.

END OF STEPS

Users can usually set an appropriate service execution interval

or operate with a small amount of data each time so as toensure that the PROC of DIF will not be fully occupied.

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions





Security Management Faults

User Logon Failure

User fails to log on the client.


1. The server process is running abnormally.

2. The configuration file is incorrect.

3. The username or password is incorrect.


1. Check configuration file to see whether parameters likeenvironment variables are set correctly.

2. Check whether server has started normally.

3. Use the correct username and password to log on.

END OF STEPS

None

User Right Operation Failure

Right-related problems occur during user operations, such asauthentication or authorization failure, or loss of specialcommand.

The fault may result from one of the following causes: Right assigned during the procedure of creating the user,

user group, or role is inadequate.

The pre-defined user group is not assigned with adequaterights.

User does not refresh information such as interface, user,user group, and role.


1. Check if the user has adequate right.

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





2. Check if the pre-defined user group has adequate right.

3. Refresh the user management interface.

4. If the fault still remains, contact the local ZTE office.

END OF STEPS

None

Operation Log Fault

Periodic deletion of operation log fails.


The command execution setting in the timer.dat file is

incorrect.

The command distribution fails.


1. Check timer.dat file to see whether there is any command

that periodically deletes the operation log. If there is not, set

the command in the operation log client.

2. Check whether LMF and DIF processes exist.

3. Set the deletion time again, Check whether deletion succeedswhen the set time is up.

END OF STEPS

None

Database Tool Faults

Database Monitoring Fault

Operation with the database monitoring interface fails.

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom






Database connection fails.

Operation involves too many data, causing command

timeout.


1. Check whether database is normal and whether the databasemonitoring server is normal.

If they are abnormal, restart database and restart thedatabase monitoring server process.

2. If the operation has no response for a long time, then:

Check whether the connection is normal.

Check whether the operation involves too many data.

Terminate the existing operation first, and issue an operationinvolving a small amount of data. Observe whether thatoperation succeeds.

END OF STEPS

None

Database Script Tool Fault

Error is reported during data import/export procedure, datadeletion fails, etc.


Database rights of import/export operation are inconsistent.

Imported/exported table structures are inconsistent.

Data are in use.


1. Check whether rights of the import/export operation areconsistent (check the returned error code to determine

whether there is short of any right, usually the fault is due to

having no public right).

2. Check whether table structures are consistent during theimport/export procedure. If they are inconsistent, contactthe local ZTE office.

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





3. If the table data to be deleted are in use, wait for a while to

perform the deletion.

END OF STEPS

None

Configuration ApplicationFaults

Resolution Failure of ReadingDatabase

Resolution fails when Integrated Configuration Environment (ICE)tool reads the database from client. For example, the syntaxerror prompt appears on line xxx when reading the database.


The client version differs from the server version.

Database information is incorrect.

Disk space of client or server is full.


1. Check whether client and server have the same version.

The client version must be consistent with that of the server.

Client version information can be obtained by selecting Help > About in main interface UISF of the client.

Server version information can be obtained by running

command amp –v on server.

2. If the two versions are consistent, open the returned script

file obtained by server to see whether the file content iscomplete.

If the script information is incomplete, check the disk spaceof client or server to see whether the incompleteness is dueto a full disk.

END OF STEPS

Precautions

Fault Symptom

Fault Cause

Analysis

Troubleshooting





None

Data Configuration Error

Client data configuration in Integrated ConfigurationEnvironment (ICE) tool has errors, including object creation,object deletion, or object modification, etc.


Data configuration does not comply with the requirements.

Big transaction conflict exists.

The foreground and background are running abnormally.

The foreground is subject to restriction in deleting, creatingand modifying the object.


1. If error occurs in the validity check, make modificationaccording to error cause. If the check is passed but thecommand sending fails, check whether any other bigtransaction on server is being executed, causing transaction

conflict. If there is no such conflict, check whether the

foreground and the background running conditions arenormal: if normal, check the log printing and solve theproblem according to the log.

2. When deleting objects such as N7PCm, cell, transceiver and

channel, the deletion will fail if the foreground is not blocked,thus ICE gives such a prompt. In this case, perform the

blocking operation in the dynamic data managementinterface first.

3. The connection must meet appropriate requirements when

creating objects such as N7Link under N7PCm or sites. If thesystem resource does not support object creation, ICC

resolution will fail. In this case, it requires adding relevantresources first and performing subsequent configuration.

END OF STEPS

Configuration should be performed after correct operationsaccording to error prompt messages.

Precautions

Fault Symptom

Fault Cause

Analysis

Troubleshooting

Precautions





File Transmission Failure of StoredSoftware

Software directory creation failure is prompted during storedsoftware loading.

The stored software is loaded to omchome/tmp/ftp/version

directory. If the directory is not created or is deleted, or has noread/write right, or the server disk space is full, the directorycreation will fail.


1. Check whether directory tmp/ftp/version exists under

omchome on server, and modify the right of the directory to

be read/write.

2. If the directory exists and is readable and writeable, checkthe server disk space. If the disk space is full, delete someuseless files.

3. If file transmission still fails, check whether the software tobe stored has already existed in appropriate stored software

directory. If the software to be stored has already existed,back up the software in another file name and then deletethe software. Store the software again.

END OF STEPS

None

Failure of Automatic Search forStored Software Directory

Automatic search for the software directory fails during storedsoftware loading.

The root directory is not set correctly, or the software directoryname is inconsistent with that of the design.


1. The root directory must be the one where relevant softwaredirectories reside, and its sub-directory name should be

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





name of the directory where relevant software resides. If the

root directory is set incorrectly, automatic search will fail. Inthis case, set the correct root directory before performing

automatic search.

2. If the root directory is set correctly, but the subdirectoryname does not match the name in software loading design,the automatic search will also fail. In this case, modify the

sub-directory name where the software resides to match thedesigned one.

END OF STEPS

None

Failure of Deleting Stored Software

Failure is returned in deleting the stored software.

Stored software may have been referenced as general softwareor board software. In such a case, the stored software is notallowed to be deleted.

Delete the referenced general software or board software first,and then delete the stored software.

END OF STEPS

Software loading should be performed carefully with permission

from the on-site technical personnel.

Failure of Querying Board Version

Running in Foreground

Query of the board version currently running in foreground fails.

If the board is configured with data but actually not in position inforeground, the query will fail.

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





1. Open the alarm management interface to check whether

there is the board not-in-position alarm. If there is, itindicates the board is not in position.

2. If the board is in position, check whether there is any other

alarm that causes the failure in querying the current runningversion.

END OF STEPS

None

Board Running Abnormal

The software loading and the general software setting are allnormal, but the board is running abnormally all the time.

The board fails or the general software version is incompatible.


1. Check whether there is any other board of the same typerunning normally. If there is, the board might fail.

2. If all the boards are running abnormally, the possible causeis incompatible general software version.

First set the software of a board and observe whether it runsnormally. If it runs normally, the general software settingmay be incorrect. If it does not run normally, it indicates thatthe general software does not support such board type,replace it with a higher version or other software version.

END OF STEPS

None

Failure of Observing Status Attributein Dynamic Data Management

Observation of the status attribute in dynamic data management

fails.

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom






Communication between foreground and background isabnormal.

Data of the foreground and the background are notconsistent.


1. First check whether the communication link has beennormally established between foreground and background.

2. If the link has been established normally, check whetherdata of the foreground and the background are consistent.

END OF STEPS

None

Failure of Observing Abis InterfaceChannel Status in Dynamic DataManagement

Observation of Abis interface channel in dynamic datamanagement fails.


Communication between foreground and background isabnormal.

Data of the foreground and the background are notconsistent.

Synchronization is in process between foreground andbackground.

Transaction conflict exists between foreground andbackground.


1. First check whether the communication link has beennormally established between foreground and background.

2. If the link has been established normally, check whetherdata of the foreground and the background are consistent.

3. If their data are consistent, check whether the foreground-

background synchronization is completed.

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





4. If synchronization is completed, check whether any other

transaction is being executed.

END OF STEPS

If system is normal and data are consistent, it is probably due toincomplete synchronization or transaction conflict. Wait for awhile to perform the operation.

Radio Resource Management Fault

Obtaining TOP tree fails and the tree isn’t displayed on the

interface.


Client and server do not have the same version.

Database information is incorrect.

Client or server has a full disk.


1. Check whether client and server have the same version.

Client and server must have the same version.

Client version information can be obtained by selecting Help > About in the radio resource client.

Server version information can be obtained by running

command amp -v on server.

2. If the two versions are consistent, check disk space of theclient or server to see whether the file incompleteness is dueto a full disk.

3. If the file content is complete, check the TOP tree file content

of the radio resource client returned from server (usually inomchome/ftpc/cmclient/ directory), and check whether

the content is correct.

END OF STEPS

None

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions





Alarm Faults

Real-time Alarms Report Abnormal

Upper-level NM fails to collect real-time alarms.


OMC does not start the process for reporting real-timealarms.

IP and TCP port of upper-level NM are incorrect.

Format of configuration file fmmgr.ini is incorrect.


1. Check fmmgr.ini file to see whether the parameter start

is 1.

2. Confirm with the upper-level NM for the correctness of IPand TCP port.

3. Check file fmmgr.ini to see whether every line is ended

with ^M. If every line ends with ^M, upload the file again in

text format (ASCII).

END OF STEPS

None

Some Fields Illegible in Real-time Alarms

Some fields in real-time alarms are illegible.

The illegible field length exceeds that defined in theconfiguration file.


1. Modify the parameter AlmTitle in configuration file

fmmgr.ini to increase the illegible field length.

2. Restart IMF after modification.

Fault Symptom

Fault Cause

Analysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





END OF STEPS

1. Back up the file fmmgr.ini before modification.

2. Make sure that total length of all fields included in the

parameter AlmValue does not exceed 2000 bytes.

Alarm Synchronization Failure

Error is returned when executing aaaa for synchronization at the

alarm client.


The alarm synchronization module is performingsynchronization of recovery of link break.

That too many records are in the alarm database causesdatabase operation failure.

Other clients are performing alarm synchronization of thesame module.

The alarm synchronization module is performing a bigtransaction operation.


1. Try again when the synchronization of recovery of linkbreak is completed.

2. Delete the outdated history alarm records in the

falarminfo table. For example, use the following SQL script

to delete the history alarms before 2005-1-1 :

Delete from falarminfo where isclear=1 andclearoper<0 andoccurtime<to_date('20050101','yyyymmdd')

3. Modify the parameter SynDBTime in configuration filefmmgr.dat to be a slightly larger value, for example,

SynDBTime=600.

4. Try again when synchronization of other clients is completed.

5. Try again when big transaction operation of the module iscompleted.

END OF STEPS

None

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions





Failure of Alarm Box Displaying Audio/Visual Alarms

The alarm box fails to display audio/visual alarms.


Client configuration file fmwsf.ini is defined incorrectly.

The control process fmpc of alarm box does not start.

The link between alarm box and the client is disconnected.


1. Ensure the alarm box chip address defined in file fmwsf.ini

is correct.

2. Open the task manager and check whether process fmpc

exists. If the process does not start, open file syscfg.ini

and set StartAlmplate=1, and log on the client again.

3. Run netstat in DOS command window to check whether

there is any link to the alarm box. If none is found, add oneIP address of the same subnet as the alarm box in clientnetwork setting. Then, log on the client again.

END OF STEPS

None

Performance Faults

Failure of Creating a PerformanceMeasurement Job

Creation of a measurement job fails.


The foreground-background link is disconnected.

Number of modules or IP address defined in configuration

file bsccfg.ini is incorrect.

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis






1. Check physical link to ensure the foreground-background link

is normal.2. Modify the configuration file bsccfg.ini and then restart

OMC server.

END OF STEPS

None

Performance Report Template NotExisting

Error prompt Report template does not exist appears when

the performance analyzer is opened.

The report template table rptemplate does not exist or is

abnormal.

Execute database script pmindex.sql (for ORACLE) orpmindex.db2 (for DB2) again.

END OF STEPS

None

Failure of Creating a Performance

ReportOMC background fails to obtain performance report data, andsystem prompts no performance data are available whencreating the performance report.


If the original table does not contain any data and no err

file is created in proc directory, BSC foreground will not

report data.

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis





Database is abnormal.


1. If no data are reported when the performance jobsynchronization is implemented at the client, thentroubleshoot in BSC foreground.

2. Check log file diffs for the printed messages such as ERROR

SQLCODE:

If the -1688 error is found, then it indicates theperformance table space is full and needs to expand

pm_space and pmindex_space , or first delete useless data

and then combine free spaces.

If the -1001 error is found, then it indicates too many

cursors are opened, exceeding the upper limit. It needs torestart Oracle and execute the pmdr command to update

the report data.

If the -4301 error is found, then it is recommended toadjust database parameters:

Modify the file initomc.ora to add the cursor_sharing

and session_cached_cursors and expand the

shared_pool_size , for example,

cursor_sharing=FORCE , session_cached_cursors=100 ,

shared_pool_size=32000000.

Restart the database after modification.3. Refresh the sharing pool (need not to restart the database)

by running the following command:

$connect internal/oracle

sqlplus>alter system flush shared_pool

4. After the above procedures are completed, rename err

performance file in proc directory to dat, and move it to the

rpt directory for re-storing. At the same time, manually

execute the command pmdr to update the report data.

END OF STEPS

It is recommended to restart the database when the services arenot busy.

Signaling Tracing FaultsTracing the EFRP LLC signaling message fails.

Troubleshooting

Precautions

Fault Symptom






No EFRP board is configured.

The configuration information obtained is incorrect, without

EFRP board information. There is no EFRP LLC signaling.


1. Configure EFRP board by integrated configuration tool.

2. Check whether IMF startup is normal and whether TOP treeinitialization is normal.

3. Set MS frequency point to or add the MS to a cell thatsupports GPRS service, and initiate the service flow throughdialing with data line or accessing the WAP network.

END OF STEPS

None

Fault CauseAnalysis

Troubleshooting

Precautions




C h a p t e r

4

Analyzing and Handling Access Faults

This chapter describes common procedures for analyzing andhandling MS access faults.

Overview

The access faults are divided into two types: location updateaccess faults and call access faults.

Common access faults include: failure of MS finding the network,

the calling party directly bounced, and no response of the calledparty.

Location Update Flow

F I G URE 1 - L O CAT I O N UP D A T E





1. The location update request of MS is sent to MSC through

the Complete L3 information message of CR. If MSC

accepts the request, it sends the location update accept

message to MS; otherwise, it sends the location updaterejection message to MS.

2. Abnormalities

If the location update request of MS is rejected, MS receives

the Location Updating Rejected message from MSC.

The possible causes are:

MSC is not configured with CGI of the cell related to BSC.

Communication between MSC and VLR fails.

MS is not registered in HLR.

Location UpdateFlow Description



Chapter 4 - Analyzing and Handling Access Faults


Call Flow

F I G URE 2 - C A L L FL O W

For the subscriber, if the flow does not reach the “talk” stage,then the call is not connected. Possible causes include:

Access failure of the calling party

Access failure of the called party

1. Access failure of the calling party

Usually, it is due to that BSC does not send the Assignment

Complete message to MSC, for example:

i. BSC receives the Assignment Request message but

BTS does not issue the Assignment Command message

Call FlowDescription





to MS. Instead, it directly returns the Assignment Fail

message to BSC.


BSC has no available TCH. The CIC assigned by MSC is not in idle state at the BSC

side.

The assignment request message of MSC is illegal, forexample, the voice version does not match the circuitgroup.

ii. After BSC issues the “Assignment Command” message toMS, MS reports the “Assignment Fail” message.


Radio environment interference exists.

Signal of the assigned channel is too weak.

Hardware faults exist.

2. Access failure of the called party

For the called party, the call flow is a little different.

First there is a paging message and then MS responds to thepaging.

Based on the call flow, the possible causes of access failureare:

The location of MS has weak signals, thus MS fails to

receive the paging message.

The paging response access fails.

Frequent Location Update

After MS is powered on, it can access the network and makecalls, but occasionally, MS can not be connected when called,and the MS battery runs out quickly.

Usually, MS location update is performed in the following cases:

When MS is powered on, it finds the network and performsa location update.

Location update upon MS power-on is necessary.

MS performs location update periodically.

If the period of periodical location update is set too short, the

location update will become more frequent.

MS is moved to a new location area

Fault Symptom

Fault CauseAnalysis





If the location area is planned to be too small, MS will

frequently cross location areas when it moves, and thelocation update will become more frequent accordingly.

More location updates consume MS battery quickly.

Meanwhile, MS is unable to respond to paging message whenperforming the location update, thus the connection failureprobability increases.

Moreover, too many location updates may affect the BSCload and increase the load of A-interface signaling link.

Perform the following steps to check A-interface signaling totroubleshoot the fault:

1. If the location update reason is Normal Location

Updating , then it is usually because that MS frequently

crosses location areas. It needs to determine whetherlocation areas are too small, and plan the location areasagain if necessary.

2. If the location update reason is IMSI Attach, then it is

usually because MS is frequently powered on/off. If there are

too many location updates, the cause may also be that MScan not receive messages from BTS due to poor radio

coverage and the low level. In this case, it needs to adjustthe radio coverage range, and if possible, increase theminimum access level of the cell.

3. If the location update reason is Periodical location

update , then the location update period may be too short.In this case, cooperate with MSC to modify the value of timerT3212.

END OF STEPS

It needs to record the A-interface signaling. Determine whether

location update is too frequent by comparing history data withdata of other offices.

Failure of MS Accessing the Network

MS often fails to access the network, and call drop often occurs.MS battery runs out quickly, with a short standby time.


MS will be disconnected from the network when it finds the

current cell level is lower than the minimum cell accesslevel in the system message, and will start cell selection to

search for the network again. If MS fails to find the network,

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis





then the fault symptom is failure of MS accessing the

network; if MS finds the network quickly, then the faultsymptom is that MS temporarily disconnects from the

network.

If the cell reselection offset parameters are setunreasonably, MS may reselect a poor cell, causing celloccupation failure.

The network color code allowed by the cell or that of theadjacent cell is configured incorrectly, which causes MS failsto reselect the cell.

The cell configuration of MSC is incomplete, causingsubscribers in some cells fail to access the network. If anyof these cells is reselected, MS will be disconnected fromthe network.

The CBA and CBQ parameters of cell are incorrectlyconfigured, causing occupation becomes difficult.

Poor signals during the call will cause poor voice quality andcall drop.

When the BSC processor is overload or RACH is overload,the flow control will start, which consequently preventssome MS from accessing the network.


1. Check whether system messages CBA and CBQ are correct,

and check system messages to see whether any subscriber isbarred from network access due to flow control.

2. Check whether the minimum access level of the cell is set

too large.

3. Check whether the jitter of BTS output power is too large. Ifit is too large, check whether the PA output is normal.

4. Check whether antenna is normal to see whether signals inthe area are too weak.

5. Check whether BTS has any abnormal alarm such as LapDdisconnection alarm.

6. Check whether any interference exists.

7. Check whether the parameter C2 is set reasonably, and

whether the parameter CRO of adjacent cell is set too large.

8. Check the cell settings of MSC.

9. Check CBA and CBQ parameter settings of the cell.

END OF STEPS

Troubleshooting

Precautions





It needs to determine the fault cause based on alarm messages,

a drive test in the area is also required.

Network Busy Prompted at CallThere is no prompting tone when dialing, and the MS screen

displays such information as network failure and network busy.

Such a fault is usually caused by resource congestion.

The call will fail in the following cases:

When congestion occurs in A-interface circuit

Assigned circuit attribute does not match the radio

channel attribute

Request for TCH resource fails

TCH is not allocated successfully in such cases, thus no

prompting tone can be heard when dialing.


1. Check whether signaling of the Abis interface and A-interfaceis abnormal and whether the signaling flow is complete.

2. If the signaling flow is incomplete and the call is not

connected, then check whether there is any available TCH. Ifthe cell has serious congestion, then:

Perform capacity expansion to add TRX.

Enable service functions such as queuing and directed retry.

Adjust the handover relationship and thresholds to makeMS difficult to handover in but easy to handover out.

Modify the reselection parameters, such as the minimumaccess level and CRO, which affect the C1/C2, to reduce thenumber of subscribers residing in the congestion cell.

Adjust the antenna direction to reduce the coverage range

of the cell.

3. If there are too many radio interface assignment failures, i.e.a high percentage of Assignment Failure in Abis signalingtracing, then:

Check whether there is any interference that causes radiointerface assignment failure.

Check whether the carrier output power of TCH is lowerthan that of BCCH. In this case, check the connectionbetween PA and BTS.

4. Check whether the A-interface circuit is blocked, and whether

its status is different from that of MSC circuit.

Fault Symptom

Fault CauseAnalysis

Troubleshooting





END OF STEPS

For such faults, it is necessary to record signaling of the Abisinterface and A-interface, from which to find out the fault cause

and decide the fault location, and thus to solve the problem.

Call Returned Without Prompt

When MS dialing a phone number, the MS screen quickly returnsto the idle state without any prompt, but sometimes “beep”sound can be heard.


Usually, it is due to SDCCH assignment failure.

MSC rejects the connection.


1. Check whether the Abis interface signaling is abnormal.

2. Check whether the immediate assignment of SDCCH iscompleted: whether the Abis interface has SDCCH

establishment indication.If the immediate assignment of SDCCH is not completed,then check whether there is any available SDCCH. If there is,then check the paging parameter setting and the CCCHsetting, and reconfigure the cell data if necessary.

3. If the immediate assignment is completed, then check

whether the Abis interface has received the Assignment

Complete message.

END OF STEPS

For such faults, it is necessary to record signaling of the Abisinterface and A-interface, from which to find out the fault causeand decide the fault location, and thus to solve the problem.

In addition, it is required to view the congestion condition ofSDCCH in the report.

Call Connection Time Long

Precautions

Fault Symptom

Fault Cause

Analysis

Troubleshooting

Precautions

Fault Symptom





When dialing a phone number, it takes a long time for the call to

be connected.

The call can be connected but sometimes a long time is neededto connect the call. The cause is that there is no available TCH

resource during the call. To avoid the call failure, either makesubscribers wait for the resource in queue or implement directedretry and request resources from the adjacent cell.


1. Check whether the queuing function and directed retryfunction are enabled.

2. Check the report to see whether any queuing or directedretry occurs.

3. Record signaling of the Abis interface and observe the wholeassignment process to find out the cause of the longconnection time.

END OF STEPS

For such faults, analysis should be made based on signaling. Donot diagnose easily to be system fault.

Called Party Not in Service Area

When dialing a phone number, the system prompts that thecalled party is not in the service area.


The network coverage is poor and the called party is

temporarily disconnected from the network, but theperiodical location update time is not due yet, thus

MSC/VLR does not update the MS status.

The paging channel is overloaded, thus the called partydoes not receive the paging message.

The called party is engaged in services such as locationupdate and cell reselection and does not respond to thepaging message.

The signal is poor, thus the access fails even the calledparty responds to the paging message.


Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





END OF STEPS

None

Emergency Call Failure

Call fails when MS calls an emergency phone number, but such a

fault does not occur when MS calls a non-emergency phonenumber.


If the cell parameter Emergency call allowed is not

enabled, then the emergency-number call will fail.

For the emergency-number call, MSC might connect it to aspecial service console or directly play the recorded prompt.Thus it is necessary to check MSC data configuration.


1. Check whether the cell parameter “Emergency call allowed”is enabled.

2. Check MSC data configuration.

END OF STEPS

None

High Priority Subscriber Access

During service-busy hour, call fails even for a high prioritysubscriber, which does not reflect the priority occupation ofresources.

The high priority subscriber refers to a subscriber whose priorityparameter value is comparatively small in the MSC assignmentmessage. BSC provides many ways for the high prioritysubscriber to occupy resource first, which includes reserving afew TCH/F for high priority subscribers, and making the lowpriority subscriber handover to adjacent cell or disconnect the

low priority subscriber to obtain channel resource in the case of

channel congestion. The fault that call fails even for a high

Precautions

Fault Symptom

Fault Cause

Analysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis





priority subscriber indicates the above measures are not taken

effectively.

Perform the following steps to troubleshoot the fault:1. Configure a certain number of reserved channels for high

priority subscribers in the cell, and set the subscriber prioritythreshold of using the reserved channels.

2. Enable the cell parameters of allowing forced handover andallowing forced disconnection.

END OF STEPS

It should be paid attention to the negative influence on low

priority subscribers caused by forced disconnection.

Set the parameters according to actual requirements. Ifreserved channel are configured, monitor the reserved channeloccupation through performance measurement to avoid resourcewaste.

Troubleshooting

Precautions




C h a p t e r

5

Analyzing and HandlingHandover Faults

This chapter describes common procedures for analyzing andhandling handover faults.

Overview

Handover faults include handover call drop, handover failure,and unable to handover.

Handover performance is an important index that influences the

network quality.

Figure 3 shows the external handover flow.

F I G URE 3 - EX T E R N A L H A NDO V ER





The figure above shows the handover flow between two BSCs

under the same MSC. The handover succeeds if the destinationBSS receives the HANDOVER COMPLETE message, otherwise,

the handover fails.

Handover Failure Ratio High

The report statistics indicates high handover failure ratio.

The handover failure of radio interface is related to the radioquality of the handover-in cell, for example, the handover-in cellhas severe interference, hardware fault, or failure of obtainingthe timing advance.


1. Find out towards which cell the handover failure ratio is highthrough handover observation or adjacent cell handovermeasurement, and then appropriately increase the handoverthreshold towards that cell according to the physicallandforms.

2. Check whether the handover-in cell with handover failure has

hardware faults in some carriers, abnormal power, or highassignment failure ratio.

3. Check whether the handover-in cell with handover failure hasinterference, and whether there is any same frequency/samecolor code.

4. Check whether NY1 and T3105 of the handover-in cell with

handover failure are set too small, which causes handover

failure.

5. Check whether the handover parameters are reasonable, andfine-tune the parameters if necessary.

6. Check whether the adjacent relation is correct, deleteunnecessary adjacent cells, and add missing adjacent cells.

7. Observe whether the uplink/downlink levels of the problemcell are balanced. Unbalanced uplink/downlink levels may

also cause handover failure.

END OF STEPS

Analyze the fault cause by creating measurement jobs related tohandover, and adjust relevant handover parameters.

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions



Chapter 5 - Analyzing and Handling Handover Faults


Failure of Handover to the Best Cell

During the drive test, it is found that MS is not handover to the

best adjacent cell


The adjacent relation is not configured correctly. Adjacentrelation configuration missing or incorrect configuration ofadjacent cell parameters will cause that handover won’ttake place.

The handover parameters of different adjacent cells may

differ, which may cause the change of handover direction.

The best adjacent cell is very busy at the moment with noavailable channel, thus no attempt will be made to handover to the best adjacent cell.

The best adjacent cell has poor radio quality, and handoverattempt has been made but fails, thus penalty is made onthe adjacent cell by system, which causes failure ofhandover towards the adjacent cell.


1. Check all configuration data of the adjacent cell, especiallywhen it is an external cell. If the parameters of the cell, such

as frequency point, MMC, and MNC, have been changed, butthose of the adjacent cell have not, then no handover willtake place.

2. Check whether Network Color Code (NCC) of the adjacentcell is consistent with that allowed by the system. If NCC ofthe adjacent cell is not within the allowed range of the cell,then MS will not attempt to handover to the adjacent cell.

3. Check the handover parameters to see whether the thresholdfor handover to the adjacent cell is too high, which causeshandover difficulty.

4. Check whether the adjacent cell is in busy hour at the

moment and whether no channels are available. The systemwill not attempt to handover to the adjacent cell if no

available channels are found.

5. Check the signaling to see whether handover is attemptedtowards the adjacent cell but the attempt fails. If handover

has failed, then penalty will be made on the adjacent cell,thus handover will bypass the adjacent cell.

END OF STEPS

Fault Symptom

Fault CauseAnalysis

Troubleshooting





View the whole process of handover through drive test. Record

the handover-out cell and all its adjacent cells, and then checkthe parameter configuration and channel congestion information

of adjacent cells one by one in OMCR.

It is very important to check data configuration of adjacent cells,since many handover failures result from incorrect dataconfiguration.

Handover Speed too Slow

The detected signal level of the adjacent cell is higher than thatof the current cell, but handover takes pace some time later

rather than immediately.

Usually, slow handover is caused by improper handoverparameters configuration:

Handover pre-processing parameters

Handover pre-processing refers to the processing ofmeasurement report by BTS. BTS averages themeasurement data of MS and those of its own, and thenreports them to BSC at a low frequency. That themeasurement is reported at a low frequency helps reduce

the load of Abis interface link, but this also results in lesstimely handover control.

Handover window value and weight value

The two parameters are used for average processing of the

measurement reports.

To avoid any abrupt change of measurement values causedby complicated radio transmission, BSC does not use theoriginal measurement data in handover decision; instead,BSC use weighted average of the measurement data. The

larger the window value, the more measure reports used inaveraging. When such weighted average of measurementdata is used for handover decision, the actual change of thelevel is concealed to some extent, which will cause slow

handover.

N value and P value for handover decision

Handover is triggered only when P measurement reportsamong the N measurement reports (average) satisfy thehandover conditions. If values of N and P are too large, thehandover conditions become difficult to be satisfied, thusinfluencing the handover speed.

Minimum handover interval

The parameter refers to the minimum interval between twohandovers. If the value is large and a handover has just

Precautions

Fault Symptom

Fault CauseAnalysis



Chapter 5 - Analyzing and Handling Handover Faults


occurred, then no handover will be implemented within the

interval, thus the handover speed is influenced.

In addition, intra-cell handover has a higher priority overother handovers. If the intra-cell handover condition is

satisfied all the times, then MS will always implement intra-cell handover instead of inter-cell handover, which will causethe speed of handover towards the adjacent cell very slow.


1. Disable the pre-processing of the problem cell, or reduce thenumber of the pre-processed reports.

2. Decrease the handover window value.

3. Adjust the N value and P value for handover decision, forexample, decrease the P value.

4. Reduce the minimum handover interval.

5. If fast level fading without handover is found through thedrive test, then enable the function of handover at fast levelfading.

6. Adjust the handover threshold to make the handoverconditions to be more easily satisfied.

7. If MS always implements intra-cell handover, thenappropriately adjust the intra-cell handover threshold.

END OF STEPS

Make adjustment according to actual conditions to solve the slowhandover. In fact, slow handover has little influence on the

services as long as it does not affect voice quality or cause calldrop. Thus it is not a fault and needs no handling. On the otherhand, modifying handover parameters to make handover speedquicker will cause handover becoming too frequent and result inincorrect handover.

Troubleshooting

Precautions




C h a p t e r

6

Analyzing and HandlingCongestion Faults

This chapter describes common procedures for analyzing andhandling congestion faults.

Overview

Congestion occurs in the case of no available resource inresource allocation.

Congestion is divided into two types: congestion of A-interface

circuit resource and congestion of Um interface radio resource.

SDCCH Congestion

The report shows that congestion occurs on SDCCH, calls andshort message service are not running normally at the moment.


The location areas are too small, thus there are too many

location updates, which causes SDCCH congestion.

Burst traffic (short messages for example) causes SDCCHcongestion.

Hardware fault of the carrier causes SDCCH congestion.

Interference on the radio interface causes congestion. Forexample, if the TCH signal coverage with the samefrequency and same TSC as those of BCCH exists near thecell, then the handover access on the TCH will be taken asa random access by the cell and cause SDCCH congestion;in the case of high receiving sensitivity, the interferencesignal will be taken as the access signal and cause SDCCH

congestion.

Fault Symptom

Fault CauseAnalysis





The traffic is too heavy and too few SDCCHs are configured,

thus SDCCH congestion is caused.

Perform the following steps to troubleshoot the fault:1. If the SDCCH congestion is caused by heavy traffic, then:

Analyze the report. If location update is too frequent, thenadjust the location area size.

If SDCCH congestion results from short message burst,then enable the SDCCH dynamic conversion function.

If SDCCH congestion results from long-time traffic overload,then increase the number of SDCCHs in configuration.

Adjust MaxRetrans (the maximum retransmission times) of

the cell to reduce random access of MS at retransmission.

2. If SDCCH congestion results from carrier fault, then

troubleshoot the hardware fault or replace the carrier torestore the number of available SDCCHs.

3. If any abnormal access request is found in the report, ortimeout is found after immediate assignment in signaling and

MS does not access the network, then check whether there isany TCH carrier with the same frequency and same colorcode as those of BCCH nearby. Handover access on theseTCHs is mistaken as random access by the cell. In this case,the frequency point plan needs to be modified.

END OF STEPS

First it should be diagnosed whether SDCCH congestion results

from heavy traffic or from faults, and then handle the problemwith appropriate methods.

TCH Congestion

The call can not be connected and the report shows TCHcongestion.

In addition to the cause of carrier fault, TCH congestion usuallyresults from heavy traffic.

In the case of heavy traffic, the most direct solution is capacityexpansion by adding TRXs in the cell.

In the case of not adding more TRXs, various other means canbe used to reduce the cell traffic, thus to alleviate TCH

congestion.

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis



Chapter 6 - Analyzing and Handling Congestion Faults



1. Adjust the antenna direction to reduce the coverage area ofthe cell.

2. Lower the carrier power of the cell to reduce the coveragearea.

3. Appropriately increase the minimum access level of the cellto groom some edge subscribers to adjacent cells.

4. Increase CRO of an adjacent cell with low traffic, so that it

will attract the edge subscribers, for traffic grooming.

5. Adjust the handover threshold to make the congested cellhave easy outgoing handover but difficult incoming handover.

6. Use the directed retry function to assign channels of the

adjacent cell when there is no channel.

7. Use the queuing function to wait in queue when no channel isavailable. During this process, any channel released will beoccupied immediately.

8. Use traffic handover to hand over some subscribers to theadjacent cell.

9. For the dual-frequency network configuration, use the forcedtransfer handover function to transfer the traffic to anothercell in the same direction.

10. Increase the number of TRXs.

END OF STEPS

When adjusting the traffic, just perform fine tuning so as not toaffect such indexes as the assignment success ratio and calldrop ratio.

A-Interface Circuit Congestion

Calls can not be connected, and the signaling shows the failure

cause is “no terrestrial resources available”.

When congestion occurs on the terrestrial circuit of A-interface,

MSC will directly release the call.


1. Check the data configuration, for example, check whetherBSC and MSC have the same A-interface circuit status, andwhether the circuit group attributes are the same.

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





2. Record the A-interface signaling and view dynamic data

management to find out the cause of A-interface circuitcongestion. If the A-interface resource is in a severe

shortage, implement capacity expansion of the A-interface.

END OF STEPS

NonePrecautions




C h a p t e r

7

Analyzing and HandlingCall Drop Faults

This chapter describes common procedures for analyzing andhandling call drop faults.

Overview

In GSM network, the call drop ratio is an important index thatevaluates the radio network quality.

Call drop will be counted in the following cases:

When BSC receives the CONN FAIL IND message fromradio interface, the call drop is counted, as shown in Figure4.

F I G URE 4 - CO NNECT I O N F A I L URE

When T3107 is timeout after the assignment or the

ASSIGNMENT COMMAND message of intra-cell handover is

sent, the call drop is counted, as shown in Figure 5.





F I G URE 5 - A SSI G NM ENT ( I NT RA -CE L L H A NDO V ER ) T I M EO UT

When T3103 for inter-cell handover within BSC is timeout,

when T8 for external handover of BSC is timeout, or whenBSC detects the LapD link broken, the call drop is counted,as shown in Figure 6.

F I G URE 6 - I NT RA -BSC/ I NT ER - B S C H A NDO V ER T I M EO UT

In the above call drop cases, the major form is radio link fault,

as shown in Figure 4. In GSM specification, there is a parameterRadio Link Timeout . When the voice quality degrades to the

extent that call can not be received and is beyond theimprovement by RF power control or handover, MS will take thisas a radio link fault and forcibly releases the link, which causes

the call drop. In GSM specification, MS has an S counter, whichis assigned with an initial value at the beginning of the call, i.e.

the value of the parameter “Radio Link Timeout”. If the MS failsto decode the SACCH message (the period is 120ms), then S issubtracted by 1. On the contrary, S is added by 2 once MSreceives a SACCH message, but S can not exceed the initialvalue assigned. MS will report the radio link fault when S

becomes 0,.The above description is for the downlink case. For the uplinkcase, the number of SACCH multiframes (the period is 480 ms)in the cell attribute table defines the uplink connection failuretime. When BTS detects that an activated connection on theradio link is damaged, it will report the CONN FAIL IND messageto BSC. The system determines whether there is any connectionfailure based on the uplink bit error rate or whether SACCH

message is correctly decoded, as selected by the user on OMCR

client. After BSC receives the CONN FAIL IND message, it

releases the resources and counts the call drop.



Chapter 7 - Analyzing and Handling Call Drop Faults


Call Drop due to Poor Coverage

Radio signals are poor and the call is disconnected during

conversation. Sometimes, metal clash sound can be heard.


Discontinuous coverage

Isolated island sites may cause call drops. On the edge of anisolated island site, the signal is weak and the quality is poor,making it impossible to handover to other adjacent cells.Thus call drop is caused.

Coverage area of BTS has complicated landforms (forexample, roads in the mountain area), the radio propagationenvironment is complicated and signals are blocked. Such

discontinuous coverage may cause call drop.

Indoor coverage

Some buildings are located together in one place with highdensity, causing the signal transmission attenuation is great.

In other cases, buildings may have thick walls, causing alarge penetration loss, thus the indoor level is low, resulting

in call drop.

Cross-cell coverage

Cross-cell coverage is formed due to various causes (too

large power for example). Therefore, MS still occupies signalsof the original service cell A even when it exceeds thedefined coverage range of adjacent cell B and reaches cell C.However, the adjacent cell C is not defined for cell A, sowhen MS performs handover to adjacent cell B of the originalservice cell A, call drop will occur since it can not find the

appropriate cell.

Call drop due to equipment fault

If the hardware equipment of one cell has problems, for

example, the antenna is blocked or the carrier with BCCHfails, the coverage area will become smaller and call drop will

be caused. In addition, unstable transmission will cause theLapD link to break, also resulting in call drop.


1. Find out the area with inadequate coverage through drive

test. For areas of isolated island BTSs and mountain areaBTSs without continuous coverage, the continuous coveragecan be formed by adding more BTSs. Moreover, the coveragearea of BTS can be expanded by the following methods:increase the transmission power of BTS; change the antennaazimuth, downtilt, and mounting height; or adopt the 80 W

Fault Symptom

Fault CauseAnalysis

Troubleshooting





large-power BTS, etc. For call drop caused by complicated

landforms (for example, tunnel, big department store,subway entrance, underground parking place, etc.), adopt

micro-cell to solve the coverage problem.

2. To ensure the indoor communication quality, adjust theantenna direction to increase the maximum transmissionpower of BTS and change the azimuth, downtilt, or mounting

height of the antenna according to the actual conditions. Ifthe problem still remains, try to adopt the indoor distribution

system.

3. For a cross-coverage cell, eliminate the cross-coverage byreducing the antenna downtilt of BTS. Meanwhile, check the

adjacent cell configuration and supplement the missedadjacent cell configuration

4. Check there is any hardware fault that causes the coverage

area too small. If the call drop ratio rises sharply and allother indices of BTS are normal, then check whether theadjacent cell is normal at the moment. The downlink may

have failed, for example, the TRX, diversity unit or antennais faulty. If it is the uplink fault, the cell will have a high ratioof outgoing handover failure.

END OF STEPS

In addition to the drive test, observe the alarm messages and

the handover measurement results. If it is the level that causestoo many handovers, then it indicates that the cell has a weaklevel.

Call Drop due to Interference

The signal quality is good during the call process but the voice is

intermittent, accompanied with metal clash sound, and the calldrop occurs in the worst case.

Interference includes co-channel interference and adjacent-channel interference.

When MS receives strong co-channel or adjacent-channelinterference signals in the service cell, the signal quality

degrades, which makes MS unable to accurately demodulate theBSIC of the adjacent cells or makes BTS unable to correctly

receive the MS measurement report, thus the call qualitybecomes worse and call drop occurs.


Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





1. Perform a drive test, view the interference band and

handover measurement data of the report to see whetherany interference exists. Interference can be avoided by

modifying the BTS transmission power, downtilt of the

antenna, or the frequency point plan of the cell concerned.2. Use discontinuous transmission (DTX), frequency-hopping

technology, power control, and diversity to reduce the

system noise and increase the system immunity againstinterference.

3. Adjust the intra-cell handover parameters relevant withinterference to reduce the handover threshold. Interferencecan be avoided by reasonable use of intra-cell handover.

4. Adjust the handover threshold and cell reselectionparameters to lower the cell traffic, thus to reduce theinterference.

END OF STEPS

View the channel interference band grade in the report todetermine whether the cell has interference. Also, according to

the handover causes found in the general handovermeasurement, check whether the interference has caused toomany intra-cell handovers. In addition, use instruments to checkfor interference of the cell. If an external interference source isdetected, find out its details and then work out a solution.

Call Drop due to Handover

The handover call drop ratio is high. Call drop occurs duringhandover.


Improper handover parameters configuration

If the signal level is low in the intersected area of two cellsand the handover threshold is set too low, then the handover

to a cell with weak signals is likely to occur. Therefore, calldrop is also likely during handover. If no appropriate cell isavailable after a handover is completed, then call drop mayoccur at the next handover.

Call drop may occur during handover in all of the followingcases: forced transfer handover and traffic handover

algorithm start in order to balance the traffic, the handoverthreshold of the destination cell is set too low, or the PBGThandover threshold is set too low or even be a negativevalue.

Precautions

Fault Symptom

Fault CauseAnalysis





The conditions of handover between sub-cells are

unreasonable. For example, the TA threshold value forhandover to sub-cell 1 is set too large, thus when MS moves

towards the direction away from BTS, call drop will occur

before the handover to sub-cell 1 is implemented. Adjacent cell incomplete

When adjacent cells are not defined completely, MS will holdthe call in the current cell, but the call will be droppedbeyond the edge of the cell coverage, for it is unable tohandover to an adjacent cell with stronger signals.

There is an adjacent cell with the same BCCH and sameBSIC.

Traffic congestion: Because of busy traffic, call drop occurswhen no destination cell is found during rescue handover.

Call drop occurs due to handover failure resulting from BTSclock out-of-syn and excessive frequency deviation.


1. Check whether the parameters affecting handover are set

properly, for example, various handover thresholds. Selectthe cell with high handover call drop ratio, and observe theadjacent cell towards which many handover failures occur.Increase the handover threshold of the relevant adjacent cell.According to the sub-cell networking condition, set the intra-cell handover parameters based on the concentric handover

or path-loss and distance handover.

2. For the call drop that occurs because that the destination

BTS has no handover channel available due to heavy traffic,solve the congestion by adjusting the traffic. For details,refer to Analyzing and Handling Congestion Faults

3. If the BTS has a clock synchronization problem, thencalibrate the BTS clock.

4. Start signaling tracing. If access to the new cell often fails

during handover, then check whether T3105 and NY1 are set

too small.

5. Appropriately increase the minimum handover interval.

6. Appropriately increase the handover failure penalty period.

7. To avoid the high-priority subscriber call drop in thehandover due to no channel available, configure some

reserved channels, or enable the cell functions of forcedhandover and forced release during handover.

END OF STEPS

Troubleshooting

Precautions





Perform the analysis according to the handover failure ratio and

assignment failure ratio, and carefully check whether theconfiguration and various handover parameters of the adjacent

cell are reasonable.

Call Drop due to AntennaConnection Error

In area near BTS, calls can be connected normally. However, inarea far from BTS, calls are difficult to connect and are likely todrop, with many assignment failures.


Feeders of the cell antenna are connected in reversed way.For example, if the transmission antenna between two cellsis connected in reversed way, then uplink signals of the cellhave a much lower level than the downlink signals, causingcall drop, unidirectional call, and call connection difficulty inplaces far away from the BTS.

Inappropriate azimuths and powers of the two antennas orthe adjacent cell antenna being incorrectly connected willcause that subscribers can receive the signaling channelSDCCH but call drop will occur once they are assigned withTCH from the other antenna.

Causes related to antenna itself (such as feeder damage,

water inflow, bending, or bad contact of connectors) willmake the transmission power and receiving sensitivityreduce thus call drop occurs. All these can be verifiedthrough measuring Standing Wave Ratio (SWR).


1. Check in OMCR whether there is any SWR alarm of the

combiner, CDU and tower amplifier.

2. Check in OMCR whether boards of BTS are working normally.

3. Confirm whether uplink/downlink is unbalanced throughuplink/downlink statistics of the report and signaling analysis.

4. Check whether the call drop is caused by unbalanced

uplink/downlink due to BTS hardware fault. For hardwareequipment fault, block the possible faulty carrier or changeover the BCCH carrier to test and verify.

5. Troubleshoot the antenna feeder fault on the site of BTS.Check whether azimuth and pitch angle of the antennacomplies with the design specification. Check whether the

feeder and jumper are connected correctly. Check whether

Fault Symptom

Fault CauseAnalysis

Troubleshooting





the antenna feeder connector is in good contact and whether

the feeder is damaged. Check whether SWR is normal.

6. Perform the drive test and dialing test to see whether BCCHfrequency point of the service cell is consistent with the

planned one, and check whether transmitting antenna of thecell is installed correctly.

END OF STEPS

Firstly, block the carrier and change over BCCH to ensure thatthe carrier is not faulty. Then, check the antenna connection atBTS to ensure that the antenna is connected correctly.

Precautions





3. If the MP can not normally start after power-on, replace it

with a normal MP. Then, observe whether the startup isnormal. If the MP can normally start, then go to the next

step; otherwise, go to step 8.

4. Connect a monitor and check whether MP can perform self-test. If it can not, the MP hardware must be faulty. In thiscase, the fault can be located according to the beep sound

during the startup (the diagnosis method is the same as thatof the PC motherboard). If the MP can perform self-test, then

go to the next step.

5. Ensure that the MP version exists in Version directory of MP.

Check whether the content of the LOGON file in the

user\super\prog directory to be executed is pointed to the

MP version in Version directory. In addition, ensure the

LOGON file attribute is read-only and hidden.

6. If no normal MP is available to replace the faulty one and allMPs can not normally start although they have been correctlyset, go to the next step.

7. Check whether the MP version is wrong. Replace the version

to verify whether it is the original version problem. Otherwise,go to the next step.

8. If no MP or version is wrong and a normal MP can notnormally start either after the faulty one is replaced, then

check whether the backplane slot or bus is faulty. Thepossible cause is that a certain board on the control layer hasnot been plugged well or is faulty.

END OF STEPS

None

Foreground-BackgroundCommunication Fault

The OMCR server fails to communicate with BSC.


IP address error

The possible causes for foreground-backgroundcommunication link establishment failure include: IPaddresses in the foreground/background configuration filesare incorrect, or the DIP switch of MP is set incorrectly.

Router problem

Precautions

Fault Symptom

Fault CauseAnalysis



Chapter 8 - Analyzing and Handling BSC Main Processor Faults


The MP hardware address update is usually not perceived in

time since MP is in a passive position in communication, withthe symptom that the communication link can not be

established within a long time after MP hardware is replaced.

Usually, the problem can be solved by resetting the router onthe near end of MP and forcibly refreshing the addressinformation. After that, the MP software will broadcast itsaddress information periodically and automatically solve suchproblems.

Cable connection problem

Two Ethernet cables are led from the back of MP board, andthe two cables have different functions. Usually, cable B isfor communication with OMCR and cable A for signalingcommunication with GPRS module. In the case of the

network not connected, check whether the two cables areconnected in the reversed way.


1. Ping the IP address of MP and check whether the MP is in

the network.

2. Check the foreground/background configuration files to see

whether the IP addresses of both parties are correct. The

foreground configuration file is TCPIP.cfg in CONFIG

directory and the background configuration file is

bsccfg.ini in CONF directory.

3. Check whether DIP switch of MP is set correctly.

4. Check whether the two Ethernet cables led from the back ofMP board are connected in the reversed way.

5. If the communication link can not be established within along time after MP hardware is replaced, try to reset therouter on the near end of MP.

END OF STEPS

None

Indicators Abnormal

The RUN indicator flashes abnormally or the FAULT indicator

(red) is abnormal.


Abnormal flashing of the RUN indicator

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis



Chapter 8 - Analyzing and Handling BSC Main Processor Faults


or important management operations. In this case, stop all the

background operations and try again some time later.

Perform the following steps to troubleshoot the fault:1. Stop all the background operations and try again some time

later.

2. Check whether the active-standby communication fails

according to the alarms.

END OF STEPS

None

Active-Standby Communication Fault

The active-standby communication of MP is disconnected, which

is usually indicated on the background alarm interface.


The active-standby communication of MP is implementedthrough the SMEM board, whose fault will cause active-

standby communication disconnection.

That DIP switches of the active and standby MPs are setdifferently (set as different module Number) can also causeactive-standby communication fault.


1. Check whether the SMEM board is in position and in goodcontact.

2. Check whether the DIP switch settings of the active/standby

MPs are consistent.

END OF STEPS

None

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions




C h a p t e r

9

Analyzing and HandlingBSC Data and SoftwareLoading Faults

This chapter describes common procedures for analyzing and

handling BSC data and software loading faults.

Overview

After BSC starts, it needs to load data and software versions for

various peripheral boards. Loading errors of some boards maycause BSC to lose some or all of its functions. Therefore, solvingsuch faults in time is of vital importance for the normal systemrunning.

Software Version Configuration Error

The board does not work normally, and version download failsrepeatedly.

The board failing to obtain the version is possibly due to boardversion configuration error, which then causes the versiondownload failure. For example, the configured version numberdoes not have a corresponding version file; or the board does

not use the general software version but specify a non-existentversion number.

Check the version configuration of relevant board and correct

the errors.

Fault Symptom

Fault Cause

Analysis

Troubleshooting





None

Version File not Existing

The board data configuration is correct, but the board does notwork normally and provide services even after a long time.

Usually, it can be determined whether a board has entered theservice status according to indicators or the alarm interface.

Causes of that a board with correct data configuration does notwork normally even after a long time include: the correspondingversion file does not exist on MP; the MP is requesting the OMCRserver for downloading the version; or the version can not beobtained from the server. Such a fault is usually caused by MPchangeover or MP replacement. In this case, the data

configuration information can be synchronized but thecorresponding version file may not exist on the hard disk of MP.

It needs to wait for MP to obtain the correct version file from theserver, and then sends it to the board to make it run normally.

To avoid such fault, copy the version directory and files in

\\Version directory to the MP to be used when replacing the

MP.


1. Check the data configuration to confirm whether the boardconfiguration is correct.

2. Wait for a period of time (more than 15 minutes) and thencheck whether the board is running normally.

3. Obtain the updated or valid board versions and store themagain.

END OF STEPS

None

Version File Check Error

The board repeatedly downloads the version.

After the board version is downloaded, the version will not start

if check error occurs on the reception end, which then causesthe board to repeatedly download the version. The check error

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis



Chapter 9 - Analyzing and Handling BSC Data and Software Loading Faults


on the reception end often results from the version file error

occurring in the transmission.

Perform the following steps to troubleshoot the fault:1. Download the version again from the server.

2. Contact the local ZTE office for the version file.

END OF STEPS

None

Failure of Standby MP ObtainingData from Active MP

The standby MP fails to synchronize data with the active MP andcorresponding notification message is displayed on the alarminterface.


The SMEM board does not work normally.

The DIP switch of standby MP is set differently from that ofactive MP.

Data of the active/standby MP are inconsistent.


1. Check whether the SMEM board works normally.

2. Check whether DIP switch of the standby MP is consistent

with module number

3. Obtain data from the active MP through OMCR and check the

data consistency of MP.

END OF STEPS

None

BTS Working Abnormally

The BTS or some boards of BTS do not start normally.

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom






The BTS configuration is incorrect.

Fault exists in connection between BTS and BSC.

The channel is manually blocked.


1. Check whether the BTS configuration is correct, includingsite type, board type, BIE connection, and software version.Modify the configuration if there is any error.

2. Check whether the connection between BTS and BSC iscorrect, whether the corresponding E1 cable is correct, andwhether the corresponding LapD board is in the appropriateposition.

3. Check whether board status on the link is normal, forexample, whether the LapD board status is normal. If theLapD statuses of the operation & maintenance module andtransceiver module are normal, then check whether thesoftware version and logic of BIPP are correct and whetherthe TIC board status is normal.

4. In the initial stages of BTS configuration, manual blockedchannels are often set. After BTS is commissioned, checkwhether the manual blocked channels have been unblocked.

END OF STEPS

None

A-Interface Circuit Blocked

The configured circuit resource of A-interface is blocked.


Data configuration of MSC differs from that of BSC.

The board related to A-interface link fails.

The voice version configuration of DSP is incorrect.


1. Check whether the data configuration of MSC and BSC areconsistent. Timeslots on both sides are required to be the

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting



Chapter 9 - Analyzing and Handling BSC Data and Software Loading Faults


same; otherwise, the fault such as MSC unequipped may

occur.

2. View the board status on A-interface link through thedynamic data management of OMCR. Or, check whether

there is anything abnormal by viewing the alarms. Takeappropriate handlings according to the abnormal cases.

3. Check whether the voice version of DSP is correct. Incorrectvoice version, i.e. voice version mismatch, may cause callfault.

END OF STEPS

None

Failure of Data Modification byOMCR

The configuration command issued by OMCR fails.


The link between OMCR and BSC is disconnected.

Data of OMCR differs from that of BSC.

The data synchronization between OMCR and MP and theintra-BSC data synchronization are mutually exclusive. Ifintra-BSC data synchronization is being implemented, thenthe data modification by OMCR will fail.

Dynamic HR channel conversion occurs on TCH/F.


1. Try again some time later to troubleshoot the fault due tointra-BSC data synchronization.

2. Check whether the link between OMCR and BSC is normal byPing packets.

3. Use the data comparison tool provided by OMCR to check

whether data of OMCR and BSC are consistent.

4. For the version that supports dynamic HR, if the TCH/F to bemodified or deleted has been converted to TCH/H, then blockthe relevant channel through OMCR so as to restore thedynamic TCH/H to TCH/F.

END OF STEPS

Precautions

Fault Symptom

Fault Cause

Analysis

Troubleshooting





None

BCCH Changeover Fault

In the case of fault occurring on BCCH carrier, a carrier of thesame type can be selected to change over the faulted BCCHcarrier so as to avoid the cell traffic interruption and guaranteethe consistency with OMCR data. In BSC V2.97, the function ofBCCH changeover between carriers of different types is added.

Fault occurs on BCCH carrier and the changeover startup fails.


The foreground-background data synchronization is beingexecuted at the moment.

The dynamic SDCCH conversion or dynamic HR conversionis being executed in the current cell.

The processing capability and configuration of the BCCHcarrier differs from that of the non-BCCH carrier.


1. Wait for a period of time till the in-process synchronization

is completed, then the BCCH changeover can start.

2. If the BCCH changeover still fails, then check whether theprocessing capability of BCCH differs greatly from that of theavailable non-BCCH carrier.

END OF STEPS

Note: For the old version, the B2 carrier’s capability ofsupporting auxiliary timeslot is 0; for the new version, thatcapability is 1 and the EDGE carrier’s capability of supporting

auxiliary timeslot is 4. To guarantee successful BCCHchangeover between these carriers, it requires that theconfigured auxiliary timeslot number of the two carriers should

be less than the minimum restriction of them.

None

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions




C h a p t e r

10

Analyzing and Handling A-Interface InterconnectionFaults


handling A-interface interconnection faults.

Overview

A-interface, the interface between BSS and MSC, follows GSM08

protocol and has three layers:1. Physical layer, adopting 2M PCM digital channel and each 2M

line having 31 64KBps channel, is used for service andsignaling channel.

2. Data link layer and network layer, i.e. No. 7 signaling MTP2,MTP3, and SCCP part.

3. BSS Application Part (BSSAP), which is divided into BSS

Management Application Part (BSSMAP) and Direct TransferApplication Part (DTAP), transfers information of BSSmanagement, mobile management, and connection control.

Faults often occurring in A-interface include signaling match fault

and timer match fault.

Service Unavailable in E1 Port

The E1 port of A-interface can not enter service status, the out

of frame fault occurs on TIC board, and TS0 all-1 alarm isreported.

Fault Symptom



Chapter 10 - Analyzing and Handling A-Interface Interconnection Faults


If it is diagnosed to be hardware problem and requires replacing

board, then implement the operation during non-busy hour inconsideration of the influence range.

No. 7 Signaling Unstable

No. 7 signaling is unstable, sometimes connected andsometimes disconnected.


Transmission problems, including high bit error ratio oftransmission equipments and bad contact of connectors

The fault is possibly due to message overflow resulting fromhigh signaling load. Usually, the unidirectional signaling linkload should not exceed 0.2 ERL.


1. Check whether connections are reliable. Test the bit errorratio of transmission.

2. Check the signaling link load through performancemeasurement. Expand the link if the load is too high.

END OF STEPS

None

SCCP Timer Matching Problem

Calls of all subscribers under the BSC are disconnected afterbeing connected for a fixed period of time.

A-interface adopts SCCP connection-oriented service in calling.Inactivity detection will start after SCCP connection is

established, and two timers (sending/receiving timers) will beused.

Once the sending timer is overflow, a detecting message will besent to the opposite end, and the receiving timer of the oppositeend is cleared upon receiving the detecting message. If the

receiving timer is overflow, it indicates abnormal case, and thenA-interface circuit is reset and call is released. Call drop willoccur if intervals of the two timers of MSC and BSC respectivelyare not matched.

Fault Symptom

Fault Cause

Analysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis





Modify the timer setting to make the inactive receiving timerinterval of MSC larger than the inactive sending timer interval

of BSC, and the inactive receiving timer interval of BSC larger

than the inactive sending timer interval of MSC as well.

Recommended value for the inactivity detecting timer differs indifferent country, refer to the local specification.

Troubleshooting

Precautions




C h a p t e r

11

Analyzing and HandlingPacket Data Service Faults

This chapter describes common procedures for analyzing andhandling packet data service faults.

Overview

GPRS, General Packet Radio Service, is one of the realizedservices of GSM Phase 2.1. GPRS provides a higher data ratethan the original 9.6 kbit/s of GSM network.

GPRS adopts the same frequency band, frequency bandwidth,burst structure, radio modulation standard, FH rules, and TDMAframe structure as those of GSM. GPRS is built on the basis of

GSM with small hardware modification, most work involvingsoftware update.

GPRS provides point-to-point and point-to-multipoint carrierservices.

Point To Point (PTP) service

The PTP service, which provides one or more packettransmission between two subscribers, is started by the

service requester and received by the receiver.

Point To Multipoint (PTM) service

The PTM service is used for sending a single message tomultiple subscribers. GPRS PTM service provides the function

that one subscriber sends data to multiple subscribers withthe single service requirement.

BVC Status Abnormal

Each cell supporting GRPS service can view the BVC status

through the dynamic data management. BVC status being





normal is one of the preconditions to guarantee the normal

packet data service.

BVC status is abnormal.


BRP blocking is not synchronized in the cell.

Cell reset is blocked.

BRP-Pn communication fault


1. That BRP blocking is not synchronized indicates the cell dataisn’t configured on BRP board. In this case, check whetherBRPGROUP configuration of the cell is correct and whetherthe corresponding PUC Munit is correct, then check whetherthe BRP board corresponding to BRPGROUP is runningnormally.

After troubleshooting the above mentioned, implementmanual changeover of BRP or BRP reset or manually modifythe cell data to trigger P0 BRP data synchronization.

2. That the cell reset is blocked is due to NSVC fault, orinconsistency between the cell routing area and location areadata and that of SGSN. In this case, first check whether

NSVC is faulty, refer to Analyzing and Handling Gb InterfaceInterconnection Faults for the troubleshooting method; thencheck the cell parameter configuration if Gb interface datacorrectness is confirmed.

3. Check whether Ethernet communications of BRP and PUC arenormal through the alarm interface. Check whether HMSboard status is normal and whether all network cables areconnected firmly and not damaged. Implement PUC board orBRP board changeover to troubleshoot the fault if necessary.

END OF STEPS

None

PDCH Status Abnormal

Each cell supporting GPRS service should be configured with thestatic or dynamic PDCH channel. The PDCH channel status beingnormal is the most important precondition to guarantee normalpacket data service.

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions



Chapter 11 - Analyzing and Handling Packet Data Service Faults


PDCH status is abnormal.


BRP blocking is not synchronized in the cell.

Cell reset is blocked.

BRP-Pn communication fault

TFI resource congestion

The channel has no frame number.


1. That BRP blocking is not synchronized indicates the cell dataisn’t configured on BRP board. In this case, check whetherBRPGROUP configuration of the cell is correct and whether

the corresponding PUC Munit is correct, then check whetherthe BRP board corresponding to BRPGROUP is runningnormally.

After troubleshooting the above mentioned, implementmanual changeover of BRP or BRP reset or manually modify

the cell data to trigger P0 BRP data synchronization.

2. That the cell reset is blocked is due to NSVC fault, orinconsistency between the cell routing area and location area

data and that of SGSN. In this case, first check whetherNSVC is faulty, refer to Analyzing and Handling Gb InterfaceInterconnection Faults for the troubleshooting method; then

check the cell parameter configuration if Gb interface datacorrectness is confirmed.

3. Check whether Ethernet communications of BRP and PUC arenormal through the alarm interface. Check whether HMSboard status is normal and whether all network cables are

connected firmly and not damaged. Implement PUC board orBRP board changeover to troubleshoot the fault if necessary.

4. Observe whether congestion can be eliminated automatically.If it can be eliminated automatically, then it indicates the cellchannel configuration does not satisfy the subscriberrequirement; otherwise, it indicates software problem that

causes the channel resource can not be released. Collect theMP log and BRP printing and return them to ZTE for solution.

5. Confirm whether BTS works normally. If the no-frame-

number symptom can not be eliminated, delete the channeland reconfigure. Collect the MP log and BRP printing and

return them to ZTE for solution.

END OF STEPS

Fault Symptom

Fault CauseAnalysis

Troubleshooting





None

MS ATTACH Failure

MS ATTACH fails and the GPRS flag isn’t displayed on MS.


NSVC connection is intermittent.

PDCH status is abnormal.

Ethernet communication between FRP and BRP is faulty.

The cell data configuration is unreasonable.

Severe radio interference exists.

The LLC signaling tracing shows the ATTACH REJECT

message.


1. Refer to NSVC Connection Intermittent for troubleshooting ofNSVC intermittent connection fault.

2. Refer to PDCH Status Abnormal for troubleshooting of

abnormal PDCH channel status fault.3. Query alarms to see whether GDPP Ethernet communication

disconnection alarm exists. If it exists, then performchangeover of PUC, FRP, or BRP to troubleshoot the fault.

4. Check whether the network operation mode is configuredcorrectly. In the case of no GS interface, the mode isconfigured to be 2; in the case of GS interface existing, themode is configured to be 1.

5. Severe radio interference refers to the following case: uplinkor downlink TBF can be viewed in RLC/MAC signaling tracing

but the ATTACH COMPLETE message sent by MS or a

complete ATTACH signaling flow can not be viewed in LLCsignaling tracing. In this case, perform adjustments related

to network planning and optimization.

6. If LLC signaling tracing shows the ATTACH REJECT message,then check the subscriber definition of the MS SIM card orcontact SGSN-side maintenance personnel.

END OF STEPS

Precautions

Fault Symptom

Fault Cause

Analysis

Troubleshooting

Precautions





LLC signaling tracing and RLC/MAC signaling tracing are effective

methods for locating the fault.

If above measures can not solve the problem yet, record MP logand the BRP and FRP printing information and return them to the

local ZTE office.

MS PDP Activation Failure

MS PDP activation fails.

If MS ATTACH succeeds but PDP activation fails, then the BSSfault can be eliminated. Possible causes of MS PDP activationfailure include:

Network of the computer connected to MS isn’t installedcorrectly.

The dial-up network setting is incorrect.

GPRS parameter setting of the MS is incorrect.


1. Ensure the dial-up network is correctly installed in thenetwork properties.

2. Check the dial-up network setting to ensure the following

data configurations are correct:

The port Number should be consistent with that connectedwith the serial port.

Rate setting is correct.

The telephone number is *99***1#

Area code can not be used in telephone number setting.

User name can be anyone, without password.

Other settings can use the default values.

3. Ensure the following data configurations of MS are correct:

Select GRPS for data link.

APN setting is correct.

Gateway setting is correct.

END OF STEPS

LLC signaling tracing and RLC/MAC signaling tracing are effectivemethods for locating the fault.

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions





If above measures can not solve the problem yet, record MP log

and the BRP and FRP printing information and return them to thelocal ZTE office.

Slow Speed of MS AccessingNetwork

The packet data service is very sensitive to line bit error ratio,thus many factors can influence the transmission rate. Thenormal slowest rates under different coding scheme are shownin Table 5 and Table 6 (single channel).

T A B L E 5 - R A TE UN DER CS CO DI NG SCHEM E

Coding Scheme

Timeslot WidthCS1 CS2 CS3 CS4

1 timeslot 5Kbps 8Kbps 9kbps 13kbps

2 timeslots 10kbps 16kbps 18kbps 24kbps



T A B L E 6 - R A TE UN DER MCS CO DI NG SCHEM E

CodingScheme

TimeslotWidth

M

C S 1

M

C S 2

M

C S 3

M

C S 4

M

C S 5

M

C S 6

M

C S 7

M

C S 8

M

C S 9

1 timeslot5Kbps

8Kbps

9kbps

11kbps

14Kb

ps

19Kb

ps

29Kb

ps

38Kb

ps

38Kbps

2 timeslots10kbps

16kbps

18kbps

22kbps

28Kbps

38Kbps

58Kbps

76Kbps

76Kbps

3 timeslots15k

bps

24k

bps

27k

bps

33k

bps

42Kbps

57Kbps

87Kbps

114K

bps

114Kbps

4 timeslots20kbps

32kbps

36kbps

44kbps

56Kbps

76Kbps

106Kbps

152Kbps

152Kbps

Data transmission rate does not meet the requirement.Fault Symptom






NSVC timeslot width is not enough.

NSVC line bit error ratio is high.

Transient interruption frequently occurs on the internalEthernet communication link.

The frame number is frequently adjusted due to high Abislink bit error ratio.

Data configuration is unreasonable.

QOS data configuration is unreasonable.

Radio quality is poor.


1. Ensure the NSVC timeslot width meets the radio interfacedata subscriber’s requirement. Increase Gb interfacebandwidth if necessary.

2. Ensure the E1 bit error ratio of Gb interface is less than 10-6.

3. Ensure the HMS and PUC board work normally and networkcables are connected firmly. Perform changeover of HMS,PUC, BRP, or FRP board if necessary.

4. Ensure the Abis link bit error ratio is less than 10-6 and thereis no falsely configured site or cascaded site. Performchangeover of relevant BIPP or PUC board if necessary.

5. Ensure both the configured packet channel number of thecell and the current coding scheme satisfy the raterequirement.

6. Ensure the RLC layer adopts acknowledgement mode.

7. Use the test MS to check the cell level and interference. Ifnecessary, contact the network planning and optimizationpersonnel to solve the problem.

END OF STEPS

If above measures can not solve the problem yet, record MP logand the BRP and FRP printing information and return them to thelocal ZTE office.

Fault CauseAnalysis

Troubleshooting

Precautions




C h a p t e r

12

Analyzing and HandlingGb InterfaceInterconnection Faults


handling Gb interface interconnection faults.

Overview

Gb interface is the interface between SGSN and BSS. Its position

in GPRS network is shown in Figure 7.

F I G URE 7 - PO SI T I O N O F G B I NT ERF ACE I N GPRS NET WO RK





SGSN establishes a packet data connection to BSS and MS

through the Gb interface to perform packet data transmission,mobility management, and session management. Gb interface is

mandatory for GPRS networking. In GPRS standard of R99 or

earlier versions, it is specified that Gb interface adopts framerelay as the transmission protocol for data link layer. SGSNcommunicates with BSS through point-to-point frame relayconnection or through the frame relay network.

Figure 8 shows the composition of Gb interface protocol stack.

F I G URE 8 - CO M PO SI T I O N O F GB IN T E R F A C E PRO T O CO L S T A C K

Protocols related to Gb interface include:

BSSGP (BSS GPRS Protocol)

It transfers the BSSGP layer signaling information andBSSGP SDU, performs flow control of Gb interface,blocks/unblocks BVC, performs dynamic configuration andmanagement of BVC, and detects errors of the interfacemessages.

BSSGP on the BSS side provides RLC/MAC with the radioaccess capability and QoS parameters about a certain MS.RLC/MAC allocates and schedules radio resources based onthese parameters. In addition, BSSGP obtains parameters

needed by SGSN from RLC/MAC, for example, cell ID andsubscriber ID of data packets.

BSSGP on the SGSN side performs downlink data flow controlaccording to the flow control parameters transferred fromthe BSS side.

BSSGPs on both sides work together to manage SGSN andBSS nodes.

NS (Network Service protocol)

It transfers BSSGP PDU, and provides load sharing of NSVC,and status management of NSVC.

FR (Frame Relay protocol)



Chapter 12 - Analyzing and Handling Gb Interface Interconnection Faults


It transfers NSVC PDU, provides NS with PVC, and performs

simple maintenance of the physical layer and PVC, forexample, validity check of the physical layer and PVC. The

PVC provided by FR and the NS-VC in NS are in one-one

corresponding.SGSN and BSS are connected through two ways on theFrame Relay layer: point-to-point, frame relay network.

The following are some basic concepts related to FR, BSSGP andNS:

PVC (Permanent Virtual Circuit)

FR provides the NS layer with permanent virtual circuitconnections, whose ID is Data Link Control Identity (DLCI).

BRCH (Bearer Channel)

This is the frame relay bearer channel, consisting of one ormultiple (32 at most) E1 timeslots. One BRCH can bearmultiple PVCs.

Four important parameters of the frame relay link:

AR (access rate): access rate of the bearer channel

CIR (committed information rate): committed

information rate of the PVC link

BC (committed burst size): committed burst rate

TC (time committed): test time committed of the

network

The above four parameters meet the following two formulas:

∑ CIR < AR

BC = CIR * TC (The units of BC, CIR, and TC are KB,

kbps, and s respectively.)

NSVC (Network Service Virtual Connection)

It is one-one corresponding to PVC and provides logic links tothe application layer. Its ID is NSVCI.

NSE (Network Service Entity)

One NSE is the combination of one NS-VC group. One BSC

can have multiple NSEs. ID of NSE is NSEI.

BVC (BSSGP Virtual Connection)

One cell is one BVC, which is identified with BVCI (BSSGPVirtual Connection Identifier) and NSEI together. One NSEcan bear multiple BVCs.

NSVC Disconnection

The NSVC is disconnected.Fault Symptom






The transmission system is faulty.

The trunk boards of GIPP and TIC are faulty.

The EFRP/FRP board is faulty.

The HW cable from GIPP to PUC is faulty, or its AB ends areconnected in the reversed way.

Configuration parameters at BSS and SGSN side areinconsistent, for example, the auxiliary timeslot number ofBRCH (i.e. auxiliary timeslot number on the E1 cable), NSEI,NSVCI, and DLCI.

E1 transmission line is self-looped at the remote end.

SGSN side is faulty.

For a link fault, two possible cases should be considered: the linkcan not be established normally; the link is disconnected afternormal establishment.


1. Link establishment failure

Check whether data configurations on both ends of Gbinterface are consistent.

Check whether the TIC board has any ‘signal loss’ alarm to

judge if Gb transmission system is faulty.

Query the alarm information of PUC, EFPR/FRP, GIPP, andTIC boards through OMCR to find out the cause of the

board fault.

Check whether the external cables between PUC, EFPR/FRP,GIPP, and TIC boards are firm, for example, if the HW cablebetween GIPP and PUC are connected firmly.

Select multiple loop points for self-loop test.

2. Link disconnection

Check whether the TIC board has any “signal loss” alarmand check whether the Gb transmission system is faulty.

Query the alarm information of PUC, EFPR/FRP, GIPP, and

TIC boards through OMCR to find out the cause of theboard fault.

Check whether the external cables between PUC, EFPR/FRP,GIPP, and TIC boards are firm, for example, whether theHW cable between GIPP and PUC are connected firmly.

END OF STEPS

Fault CauseAnalysis

Troubleshooting



Chapter 12 - Analyzing and Handling Gb Interface Interconnection Faults


For the interface problem between communication NEs, it

requires both sides of the interface work together totroubleshoot the problem.

In addition, self-loop test is often used to quickly locate the fault

range. Select multiple loop points for the self-loop test, forexample, TIC E1 port, near-end DDF, and far-end DDF. Afterself-loop, open the FRP/EFRP board printing to see whether

there is any “syntax error” printing. If there is, it indicates theself-loop link transmission is normal, otherwise, it indicates the

self-loop link transmission is faulty.

NSVC Connection Intermittent

The NSVC connection is intermittent.


Impedances of the frame relay interface boards on bothends of BSS and SGSN do not match.

The frame relay boards of GIPP and TIC are faulty.

Connectors of the distribution frame or the E1 cable are notstable, and the bit error ratio of E1 transmission line is too

high, thus causing bit errors of the link becoming more andthe transmission of upper-layer link becoming unstable.


1. Check whether bit error ratio of the transmission system is

too high. Particularly, in the case of the link from BSS toSGSN being long and passing area with harsh natural

environment, use a BER tester or PCM analyzer to test E1channel for accurate bit error ratio. Usually, the bit errorratio can not exceed the 10-6 order of magnitude.

2. Query the alarm information of PUC, EFPR/FRP, GIPP, andTIC boards through OMCR to see whether the board fails and

find out the fault cause. For the main control board, use such

method such as active/standby changeover to locate thefault. For other boards, use such method as replacing theboard to locate the fault.

3. Check whether the external cables between PUC, EFPR/FRP,GIPP, and TIC boards are firm, for example, whether the HW

cable between GIPP and PUC are connected firmly.

END OF STEPS

None

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions





NSVC Congestion

NSVC congestion occurs.

When configuring BC, it should be guaranteed:

BC (unit: KB) = TC (unit: S) × AR (unit: KB), where AR = 64 ×number of E1 timeslots.

Otherwise, the NSVC link congestion will occur easily.

Check the configuration of parameters such as BC and TC, andmake them satisfy the above formula. In this way, congestioncan often be eliminated.

None

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions




C h a p t e r

13

Analyzing and HandlingClock Faults

This chapter describes common procedures for analyzing andhandling clock faults.

Overview

There are two cases of the clock signal flows of BSC: clock signalflows with no submultiplexing, clock signal flows with sub-multiplexing.

Clock signal flows of BSC with no submultiplexing

F I G URE 9 - CL O C K S I G N A L FL O W S (N O SU B M U L T I P L E X I N G)





The TIC of AIU extracts clock from the E1 signals from MSC

and sends it to SYCK through AIPP. The SYCK board tracesthe inputted reference clock signals, filters jitter and drift of

the external reference through the phase-locked circuit and

algorithm, and get the highly stable clock signals needed bythe system (16 MHz, 8 kHz, and 8 MHz, etc). Then, the SYCKboard provides 16 MHz and 8 kHz clocks to the BOSN board,and 8 MHz and 8 kHz clocks to the DSNI-PP and DSNI-MPboards. The DSNI-MP board provides the frequency-divided 4MHz and 8 kHz clocks to the COMM/ECOM board. The DSNI-

PP board provides 8 MHz and 8 kHz clocks to each PP board.

Clock signal flows of BSC with submultiplexing

F I G URE 10 - CL O C K S I G N A L FL O W S (SU B M U L T I P L E X I N G)

T IC ( A IU )

AIPPD RT / E DR TT IC ( F SM U)

TCPPFSP

P

SYCKCKI

A IPP

T IC ( A IU )

( E ) B RP( E ) F RPT IC ( G IU )T IC ( N SM U)COMI

E CO M/ C OM MPUCGIPPNSPPBIPP

D SN I - M PDSNI-

P

PBOSN

SYCKCKI

AIPP

T IC ( N SM U)

ECOM/COMM RMU

16 M / 8 K 8 M / 8 K

8 M / 8 K

4 M / 8 K

8 M / 8 K

Ater

MSC

4 M / 8 K

T IC ( B IU )

8Kframesynchronizationreferencesignal

BITSreferenceclock

8Kframesynchronization

referencesignal


referencesignal


referencesignalBITSreferenceclock

The difference between the clock signal flows with

submultiplexing and that without submultiplexing is: The



Chapter 13 - Analyzing and Handling Clock Faults


remote rack also has a separate SYCK board to provide

clocks. The SYCK board of the remote rack extracts 8 kHzclock from the AIU TIC board for synchronization. The SYCK

board of the central rack extracts 8K clock from the TIC

(NSMU) board for synchronization.If the clock sent to the board is faulty, the board will notwork normally (for example, the MPPP communication is

disconnected, and the board resets repeatedly). Besides,each board has a clock detection circuit. If the clock sent to

the board is intermittent, the board will report a clock fault.

This chapter mainly discusses the clock unit faults (CKI andSYCK).

Tip:

There are two types of reference clock sources: the 8K clockextracted by TIC from the A-interface (or Ater interface) E1 line;the BITS clock.

If the BITS clock is available on the site, the clock is inputtedthrough CKI board, which provides four types of clock interfaces:2 MHz, 2 MBIT, 5 MHz, and 8 kHz. Select one of them as theclock reference of SYCK board.

If the BITS clock is available on the site and the system is not

configured with CKI board, TIC extracts the 8K clock from the A-interface (or Ater interface) E1 line and sends it directly to SYCK.

Major Alarm of BSC Clock Board

The ALARM indicator of the board flashes. The following are

found through background alarm query:

8 MHz frame header signal output fault, cause code: 11;

8 MHz clock output fault, cause code: 12;

16 MHz frame header signal output fault, cause code: 13;

16 MHz clock output fault, cause code: 14

The board is faulty.

If only the active board has alarm, change over the SYCK boardto start the standby board. Then, replace the faulty board forrepair.

If both boards have alarms, replace them in turn to minimize theimpact.

Fault Symptom

Fault CauseAnalysis

Troubleshooting





None

Minor Alarm of BSC Clock Board

The D/A conversion exceeds the range, cause code: 16.

This is the critical point alarm for frequency adjustment of thephase-locked loop, a minor alarm usually occurring when the

inherent clock frequency deviates from the control range of thephase-locked loop (the control signal exceeds 3/4 of the clockadjustment range) due to clock crystal aging. The clockadjustment on SYCK board is implemented by controlling thecrystal oscillator output with the voltage converted from controlsignals through D/A conversion. Thus it is possible that thecontrol signal exceeds 3/4 of the maximum of D/A in the case of

the clock crystal is aging.

Replace the faulty SYCK board.

None

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions




C h a p t e r

14

Analyzing and HandlingVoice Faults

This chapter describes common procedures for analyzing andhandling voice faults.

Overview

For the full rate voice coding, DRT/EDRT frames the voicesignals received from MSC at the rate of one frame per 20 ms.One frame of voice data consists of 160 PCM sampling points,totally 1280 bits, and 260 bits are outputted after coding, thus

to form the 320-bit TRAU frame with the synchronization headerand control parameters.

For the enhanced full rate coding, DRT/EDRT frames the voicesignals received from MSC at the rate of one frame per 20 ms.One frame of voice data consists of 160 PCM sampling points,totally 1280 bits, and 244 bits are outputted after coding, thusto form the 320-bit TRAU frame with the synchronization headerand control parameters.

For the half rate coding, DRT/EDRT frames the voice signalsreceived from MSC at the rate of one frame per 20 ms. Oneframe of voice data consists of 160 PCM sampling points, totally

1280 bits, and 112 bits are outputted after coding, thus to formthe 160-bit TRAU frame with the synchronization header andcontrol parameters.

Decoding is the reverse process of coding. After receiving TRAUframes from BSC, DRT/EDRT restores them into voice dataaccording to the decoding algorithm and sends them to MSC.

In voice processing, GSM adopts the Discontinuous Transmission

(DTX) technology. DTX includes Voice Activity Detection (VAD)and Silence Descriptor (SID). TRAU detects the data from MSCthrough the VAD module. If there is no voice information, thevoice flag bit is cleared in the TRAU frame created after coding.

After BTS identifies the flag bit, it disconnects the transmission





on the downlink, until the flag bit is reset. When receiving the

uplink frames, TRAU will also check the SID flag. If the SID flagis set, it indicates that MS is in the inactivity period of

transmission. To allow the call reception end to perceive the

continuous service of GSM network, TRAU adopts an alterativetechnology by inserting comfortable noise to the uplink to avoidthe feeling of disconnection for the subscriber. After TRAUadopts DTX, the transmission power of BTS and MS are reduced,so is the co-channel interference of the radio interface.Meanwhile, voice signals of the GSM system are less sensitive to

the radio interface errors.

Timeslot Call Abnormal

When calling in the GSM network, distinct noises exist

sometimes. In extreme cases, call becomes abnormal andcrosstalk or call failure may occur.

Abnormal call may result from the radio part problem or the

connection problem of call timeslot of the equipment.

The radio part problem may be caused by frequency interference,which is divided into the interference due to frequency planning

and the external frequency interference.

The connection of BSS refers to the connection from the TC unitof BSC to the BOSN board, and then to the BIU unit, the BTS

(E)BIE board or CMM board, and the backplane of each layerthrough a backplane with the PCM cable of (E)BIE or CMM, thusto establish connections with each carrier. Finally, a connection

is made to PA through the carrier, and signals are transmittedfrom the combiner through the antenna feeder system. The

receiving process is the reverse.


1. Query whether DSP of DRT/EDRT of the TC unit is normal.

2. Query whether the BOSN connection is normal.

3. Query whether the connection of (E)BIE or CMM board isnormal.

4. Check the connection from the backplane (E)BIE of the publicframe or CMM to the PCM cable of each layer.

5. Check DSP of the TRU unit.

6. Observe the influence on the opposite end MS by the seriousinterference band in TRU.

7. Check whether the jitter of BTS output power is too large. Ifit is too large, check whether the PA output is normal.

Fault Symptom

Fault CauseAnalysis

Troubleshooting



Chapter 14 - Analyzing and Handling Voice Faults


8. Check whether the antenna is normal to see whether signals

in the area are too weak.

9. Check whether BTS has any abnormal alarms, for example,LapD disconnection alarm.

10. Check whether there is any frequency interference.

END OF STEPS

For active/standby BOSN board changeover, first reset thestandby BOSN board and perform BOSN board changeover onlyafter the standby BOSN board runs normally. Otherwise, existing

calls in the network will be affected.

Uplink/Downlink Voice Quality Fault

The uplink/downlink voice quality is poor.

Whether the radio signal strength and quality have problems canbe decided by the following respects: whether always the sameBTS has such problem, whether sudden metal clash can beheard, and whether call drop often occurs. If all BTSs have theuplink/downlink voice quality problem, then check whether theDRT/EDRT DSP algorithm software has problem.


1. Make calls to each other between a MS and a fixed telephone.If the voice heard on the fixed telephone is abnormal, then itindicates problem existing in the uplink. If the voice heard onMS is abnormal, then it indicates problem existing in thedownlink.

2. Call the local fixed stations such as music station of phonenumber query station by MS. If the voice heard on MS isabnormal, then it indicates problem existing in the downlink.

3. Perform the dialing test in various cells. If all BTSs have this

problem, then the fault must reside in the DRT/EDRT DSPalgorithm software. In this case, contact the local ZTE office.

END OF STEPS

Perform the drive test in different cells to see whether all BTSshave the same problem.

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions



Chapter 14 - Analyzing and Handling Voice Faults


SerialNumber

Troubleshooting DescriptionConclusion andRelatedInformation

5

Occurrence probability of the voice

fault

6Whether the voice vault occurs toonly one particular BTS

7Whether the voice fault occurs to theintra-BSC BTS or inter-BSC BTS

8Whether the voice fault occurs withinone network or between networks

9Whether the voice fault occurs to theuplink or downlink of voice channel

10Whether the voice fault is related tothe timeslot of a particular A-interface trunk circuit

11Whether the voice fault is related toMS

12Whether the voice fault is related toON/OFF of DTX

13

The voice interception results of theA-interface and Abis interface whenthe voice fault occurs

(Voice interception instruments suchas LITE3000/LITE3000E are needed)

Echo Problem

Echo is heard during the call.


Echo may occur at the 2-4 line conversion places of the

fixed subscribers, thus it requires connecting an echo

suppressor with the trunk when MSC connects the fixednetwork. Therefore, echo suppressor fault or a few trunksnot connecting echo suppressors may all cause the echoproblem.

The fault may be due to MS problems. If relevant MShardware is faulty in the process of voice coding till radio

transmission, the echo problem will occur.

The fault may be due to BTS hardware problems. Faultsoccurring in BTS demodulation parts or channel decodingparts may cause the echo problem.

Fault Symptom

Fault CauseAnalysis





The self loop of a few A-interface circuits or inter-office

trunks will cause that only one’s own echo can be heardand the opposite party’s voice can not be heard.


1. Ensure whether the fault exists only in a few MSs.

2. Check whether the trunk self loop exists.

3. Check whether the echo suppressor of MSC works normally.

4. Decide which hardware of BTS is related to the fault through

dialing test and signaling tracing, and replace relevant faultyhardware.

END OF STEPS

Implement the hardware-related operations in low-traffic hour.

Troubleshooting

Precautions




C h a p t e r

15

Analyzing and HandlingBoard Faults

This chapter describes common procedures for analyzing andhandling board faults.

Overview

Figure 11 shows the overall hardware structure of ZXG10-BSC(V2).

F I G URE 11 - O V E R A L L H A R DW A RE ST RUCT URE O F ZXG10-BSC (V2 )

BIU

BO

SN

NS

MU

FS

MUTCU AI U

SCU

RMM1

E1

Abis

Interface Gb Interface

OMM

TCUnit

PCU

GIU A-

InterfaceTCU AI U

TCU AIU

TCU AI U

RMU

BIU

8M×2

2M×8

BIU

RMU

BIU

8M×2

2M×8

8 M ×2 ( o r 4 )

8M×2

8M×2

SCM

2M×16

8M×2

8M×2

Abis

Interface

RMM6

ZXG10-BSC (V2) consists of multiple boards, and failure of anyof them will affect some or all functions or performance of thesystem. Table 8 lists the boards of ZXG10-BSC (V2).





T A B L E 8 - B O A R D L I ST

Abbreviation Full Name Abbreviation Full Name

MP Main processor EDRTEnhanced dual-rate transcoder

SMEM Share memory DRTDual-Ratetranscoder

ECOMEnhancedcommunication

PUCPacket unitcontroller

MON Monitor board BRPBSSGP RLC/MACprotocol processor

PEPD

Peripheralenvironment &power detectboard

FRPFrame relayprotocol processor

PCOMPacketcommunicationboard

HMS100M Ethernetswitching board

BOSNBit-orientedswitchingnetwork

GPPGeneral peripheral

processor

SYCKSynchronousclock board

COMICommunicationInterface board

CKIClock interfaceboard

TICTrunk interfacecircuit

DSNI

Digital

switchingnetworkinterface

POWB Power B

POWP Power P COMMCommunicationboard

EFRP

Enhancedframe relayprotocolprocessor

EBRPEnhanced BSSGPRLC/MAC protocolprocessor

BOSN Board Fault

It is reflected that communication disconnection, crosstalk, orservice interruption exists.

MPPP communication of the BOSN is faulty, or hardware of theswitching network is faulty.


Fault Symptom

Fault CauseAnalysis

Troubleshooting



Chapter 15 - Analyzing and Handling Board Faults


1. If the standby BOSN is faulty, reset it or replace it for

troubleshooting.

2. If voice connection error or crosstalk occurs, performactive/standby BOSN changeover.

3. If BOSN is running normally but the fault occurs to calls

within the whole network, then check whether the pathissued from MP to BOSN is normal and whether MPPP boardis faulty.

4. Download the BOSN version again.

END OF STEPS

For active/standby BOSN changeover, reset the standby BOSN

first and perform BOSN changeover only after the standby BOSNruns normally; otherwise, existing calls in the network will beaffected.

Be sure to wear an antistatic wrist strap when touching a boardor component.

DSNI Board Fault

HW communication link disconnection alarm is reported, or thePP unit is faulty.

The DSNI board and hardware of the backplane are faulty, orthe foreground/background data configuration is incorrect.


1. Check whether power switch of the layer where the DSNIboard is located is turned on.

2. Reset or plug/unplug the DSNI board to check whether thefault is due to bad contact.

3. Replace the DSNI board. If the fault is eliminated, then itindicates the original DSNI board is damaged.

4. Check the clock. If no clock is available, the fault indicator ofthe DSNI board will turn on.

5. Check hardware data configuration to see whether the DSNI

board is configured correctly.

6. Check the X3 and X4 jumpers of the DSNI board to ensurethat they have been set to SP-level and MP-level DSNI board.

7. Plug the faulty board to another slot. If the fault still remains,

then try to replace the backplane.

Precautions

Fault Symptom

Fault Cause

Analysis

Troubleshooting





END OF STEPS


GPP Board Fault

Alarm indicator of the GPP board is always on or acommunication link disconnection alarm is reported.

BSC (V2) adopts hierarchical management mechanism, where all

peripheral PP units are generally called GPP units (including BIPP,AIPP, TCPP, and GIPP), which are compatible with each other inhardware. Related parts include MPPP, DSNI, BOSN, MP, andboards under their management.

The fault may be caused by MPPP communication fault of theGPP, or other hardware problems of boards.


1. Check whether both the active and standby GPPs are faulty.

If only one board is faulty, then first troubleshoot the faulty

board by resetting or replacing it (the GPP boards arecompatible with each other).

2. Check whether the BSC clock is abnormal. If it is abnormal,first troubleshoot the BSC clock fault.

3. Check whether the corresponding BOSN, MPPP and MP arefaulty. If such faults exist, troubleshoot them first.

4. Check whether the corresponding DSNI board is pluggedfirmly or is faulty. If it isn’t plugged well or is faulty,troubleshoot the DSNI board fault first.

5. Check whether the background configuration data is

consistent with ZDB data in DATA directory of the foregroundMP.

6. Query the background data and HW cable configuration to

see whether they are consistent with the physical connection.

7. Check whether the backplane HW cable connection is looseor is plugged in a wrong slot, thus causing loss of clock.

8. Try to change the HW ID.

END OF STEPS

Precautions

Fault Symptom

Fault Cause

Analysis

Troubleshooting





Be sure to wear an antistatic wrist strap when touching a board

or component.

DRT/EDRT Board FaultDSP is faulty or communication with the corresponding TCPP is

disconnected.

Communication between TCPP and DRT/EDRT is faulty.Hardware of the TCPP board is faulty. DSP on the DRT/EDRTboard is faulty.


1. Check whether the corresponding TCPP board is faulty. If it isfaulty, troubleshoot the TCPP board fault first.

2. If the DSP is faulty, then go to step 6.

3. Check whether there is any clock loss alarm from this board.

If there is, then reset and unplug/plug the relevant board.

4. Check whether the backplane connection cable is loose ormodified.

5. Check whether the foreground and background data areconsistent and whether relevant data are configured.

6. Download the DRT and EDRT versions again and reset theboard.

7. Replace the DRT/EDRT board. If the fault still remains, plugthe board to another slot.

END OF STEPS


TIC Board Fault

Communication between the trunk interface board and maincontrol GPP is disconnected, the 8M/8K clock of the trunkinterface circuit is lost, or the 8K clock of the trunk interfacecircuit is lost.

The related parts include AIPP and TIC, BIPP and TIC, and GIPP

and TIC. The TIC hardware is faulty.

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis






1. Check whether the corresponding GPP board is faulty. If it

is faulty, troubleshoot the GPP board fault first.2. Reset or plug/unplug the TIC board.

3. Reset the main control GPP board.

4. Replace the TIC board.

5. Check whether the foreground and background data areconfigured and consistent. If the configuration is correct,

then try to plug the board into another TIC slot.

6. Replace the GPP board.

7. If the fault still remains, then replace the backplane.

END OF STEPS


PCM Alarm of TIC Board

The receiving signal is lost or an all “1”s alarm is reported.

The fault is mainly caused by the interconnection problembetween TIC and other E1 equipments.


1. Check whether the corresponding E1 cable is normallyconnected. If the fault still remains, go to the next step.

2. Check whether the E1 cable is in good condition. Performlocal and remote self-loop to locate the fault. If the alarm

disappears after self-loop, then the E1 cable must be faulty;otherwise, go to the next step.

3. Replace the TIC board.

END OF STEPS


Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions





4. Unplug/plug the board again to see whether the fault can be

eliminated.

5. Reset or replace the FRP/BRP board.

6. If the fault still remains, try to plug the board into anotherFRP/BRP slot.

END OF STEPS


Disconnected UDP Ethernet

Communication of BRP

The UDP Ethernet communication between BRP and MP isdisconnected.

The related parts are BRP, HMS, and MP. The UDPcommunication of the board is abnormal. If the alarm lasts long,the services will be affected.


1. Check whether there is any other alarm that isn’teliminated for this board. If there is, eliminate the alarm first.

2. Reset the board.

3. Check whether the network cable connection from PUC toHMS is correct.

4. Check whether connection of the two network cables at theback of MP is correct.

5. Check whether communication between MP and HMS isnormal (check whether the TCP/IP setting of MP is correct).

END OF STEPS


Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions





HMS Board Fault

Communication between the HMS board and the main control PP

is disconnected.

Hardware of HMS or the main control PP is faulty.


1. Check whether the main control PP board is faulty. If it is

faulty, troubleshoot the PP board fault first.

2. Check whether the HMS board is plugged firmly.

3. Reset, change over, or replace the HMS board.

END OF STEPS


MPPP Board Fault

Communication between the MP and the PP board fails.

The related parts are MP, BOSN, DSNI, and PP unit. This alarmmay also be caused by communication disconnection betweenthe MPPP communication board and the MP, power failure,hardware fault, loss of clock, or board not in position. MPPPboard usually works in the active/standby mode, thus failure ofone MPPP board will not influence normal system running but

will influence the system reliability. However, failures of bothMPPP boards may lead to the operation and maintenance linkdisconnection between MP and relevant PP board as well as out

of control of the relevant PP board.


1. Check whether the MPPP board is powered on.

2. Check whether there is any alarm from the clock board. Ifthere is, troubleshoot the clock board fault first.

3. Reset the MPPP board and observe whether the fault remains.

4. Check whether the cable connection of the backplane is loose.

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault Cause

Analysis

Troubleshooting





5. Reset the corresponding DSNI board and observe whether

the fault remains.

6. Replace the board if all steps above fail.

END OF STEPS


or component. Only one DSNI board can be reset at a time. Onlyafter the previously reset board runs normally can the next DSNIboard be reset.

MTP2 Board Fault

Communication between MTP2 boards fails or an SS7 alarm isreported.

The related parts are MP, BOSN, DSNI, and ECOM.

This alarm may also be caused by disconnection ofcommunication between MTP2 and MP, power failure, hardwarefault, loss of clock, or board not in position. MTP2 board usuallyworks in the active/standby mode. Thus failure of one MTP2board will not influence normal system running but will influencethe system reliability. Failure of both MTP2 boards may lead tocommunication link disconnection between BSC and MSC as wellas disconnection of all services related to the SS7 board.


1. Check whether the MTP2 board is powered on.


3. Reset the MTP2 board and observe whether the fault remains.


5. Reset the corresponding DSNI board and observe whetherthe fault remains.


END OF STEPS


or component. Only one DSNI board can be reset at a time. Onlyafter the previously reset board runs normally can the next DSNI

board be reset.

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions





MON Board Fault

The MON board can not run normally and the alarm indicator is

on.

The related part is the MP backplane. This alarm may also becaused by communication disconnection between MON and MP,power failure, hardware fault, loss of clock, or board not inposition. The fault may lead to the case that system is unable to

monitor the running conditions of boards such as the powerboard, clock board and network driver board.


1. Check whether the MON board is powered on or pluggedfirmly.


3. Reset the monitor board and observe whether the fault

remains.



END OF STEPS


or component.

PEPD Board Fault

The PEPD board can not run normally.

This alarm may also be caused by communication disconnection

between PEPD and MP, hardware fault, loss of clock, or boardnot in position. The alarm may cause the system unable tomonitor the equipment room environment including temperature,humidity, and smoke, thus reducing the system maintainability.


1. Check whether the PEPD board is powered on or plugged

firmly.

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





2. Check whether there is any alarm from the clock board. If

there is any, troubleshoot the clock board fault first.

3. Check whether the cable connection of the backplane is looseor abnormal.


END OF STEPS


LapD Board Fault

The LapD board can not run normally.

This alarm may also be caused by communication disconnection

between the LapD board and MP, hardware fault, loss of clock,or board not in position. The alarm may lead to LapDcommunication link disconnection, disconnection of signalinglinks of all sites related to this board, and abnormal running ofsystem services.


1. Check whether the LapD board is powered on or pluggedfirmly.

2. Check whether the clock board is normal. If it is abnormal,

troubleshoot the clock fault first.

3. Reset the LapD board and observe whether the fault remains.



END OF STEPS


MPMP Board Fault

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom





3. Reset the PCOM board and observe whether the fault

remains.



END OF STEPS


COMI Board Fault

The COMI board fails or communication between the COMI board

and main control PP is disconnected.

This fault may result from loss of 8M or 8K clock of thecommunication interface board, causing abnormalcommunication or failure of the communication interface boardas well as partial breakdown of BSC. Moreover, the COMI faultmay also lead to peripheral module failure. BIPP may havesomething to do with the fault.


1. Check whether the clock unit of BSC is running normally. If

there is any alarm from the clock unit, troubleshoot the clockunit fault first.

2. Check whether there is any BIPP board alarm. If there is any,

troubleshoot the BIPP board fault first.

3. Reset the COMI board and observe whether the fault remains.

4. Unplug/plug the board to see whether the fault can beeliminated.

5. Check whether the backplane cable of BSC is normal.


END OF STEPS


Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions





POWB Running Abnormal

POWB is running abnormally.

The hardware of the board or backplane is faulty.


1. Check whether POWER B is turned on.

2. Power off and plug/unplug the POWER B to check whetherthe fault is caused by bad contact.

3. Replace the POWER B.

4. Troubleshoot the backplane fault (the slot pins may be short-circuited).

END OF STEPS

The power board is not hot swappable.

POWP Running Abnormal

POWP is running abnormally.

The hardware of POWP is faulty or the connection cable isincorrect.


1. Check whether POWER P is turned on.

2. Check whether both inputs of POWER P are normal.

3. Replace the POWER P.

END OF STEPS

Pay attention to the positive and negative poles of the inputpower.

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions





Fan Running Abnormal

The fan is running abnormally.

The POWER P or fan is faulty in hardware or mechanics.


1. Check whether POWER P is running normally since the fan ispowered directly by POWER P.

2. Check whether there is any electric or mechanical fault in thefan itself. Replace the fan if there is any fault.

END OF STEPS

None

All PP Units Unable to Start Normally

The link of a peripheral module is disconnected and the servicesof all sites under this peripheral module are disconnected. The

board fails to establish links.

The fault may result from MP fault, MPPP hardware fault, BOSN

hardware fault, or DSNI hardware fault.


1. Check whether the central module MP is normal. If it isabnormal, troubleshoot the MP fault first.

2. Check whether the BSC clock is normal. If it is abnormal,

troubleshoot the clock fault first.3. Check whether the MPPP board is normal. If it is abnormal,

troubleshoot the MPPP board fault first.

4. Check whether the BOSN board is normal. If it is abnormal,troubleshoot the BOSN board fault first.

5. Check whether the MP-level and PP-level DSNI boards arenormal. If they are abnormal, troubleshoot the faults first.

6. Check whether the HW cable connection of each PP unit is

correct and reliable.

Fault Symptom

Fault CauseAnalysis

Troubleshooting

Precautions

Fault Symptom

Fault CauseAnalysis

Troubleshooting





ii. If the alarm is false, then the temperature range may be

set inappropriately.

iii. If the temperature range setting is correct, then checkwhether the temperature/humidity sensor is faulty.

iv. Check whether the alarm results from the PEPD board

fault. If the PEPD board is faulty in hardware, replace thePEPD board.

END OF STEPS

Humidity too high alarm


i. Check whether the dehumidifier is running normally.

ii. If the alarm is false, then the humidity range may be setinappropriately.

iii. If the humidity setting is correct, then check whether thetemperature/humidity sensor is faulty.

iv. Check whether the alarm results from the PEPD boardfault. If the PEPD board is faulty in hardware, replace thePEPD board.

v. If the alarm still remains, reduce the humidity.

END OF STEPS

Humidity too low alarm


i. Check whether the humidifier is running normally.

ii. If the alarm is false, then the humidity range may be setinappropriately.

iii. If the humidity range setting is correct, then checkwhether the temperature/humidity sensor is faulty.

iv. Check whether the alarm results from the PEPD boardfault. If the PEPD board is faulty in hardware, replace the

PEPD board.

v. If this alarm still remains, increase the humidity.

END OF STEPS

Infrared alarm




A p p e n d i x

A

Abbreviations

Abbreviation Full Name

A

AC Alternate Current

ACF Agent Control Function

AGT AGenT

APN Access Point Name

B

BOSN Bit-Oriented Switching Network

BRP BSSGP RLC/MAC Protocol processor

BSC Base Station Controller

BSS Base Station Subsystem

BTS Base Transceiver Station

BVC BSSGP Virtual Connection

BVCI BSSGP Virtual Connection Identifier

C

CCF Command Control Function

CIR Committed Information Rate

CKI ClocK Interface board

COMI COMmunication Interface board

COMM COMMunication board

D

DIF Database Interface Function

DLCI Data Link Connection Identifier

DRT Dual-Rate Transcoder

DSP Digital Signal Processor

DTI Digital Trunk Interface

E






EDRT Enhanced DRT

EGSM Enhanced Global System for Mobile communication

F

FRP Frame Relay Protocol Processor

FSMU Far SubMultiplexing Unit

FUC Flow Unit Controller

G

GIPP Gb Interface Peripheral Processor

GPO Global Post Office

GPP General Peripheral Processor

GPRS General Packet Radio Service

GPS Global Positioning System

GSM Global System for Mobile communication

H

HDLC High level Data Link Control

I

IE Internet Explorer

IMF Integrated Management Function

L

LAPD Link Access Protocol on the D channel

LED Light Emitting Diode

M

MON MONitor board

MP Main Processor

MPMP MP To MP

MPPP MP To PP

MS Mobile Station

MSC Mobile Switching Center

MSS Mobile Switch System

MTP Message Transfer Part

N

NE Network Element

NMS Network Maintenance System

NSMU Near Sub Multiplexing Unit

NSPP Near Submultiplexing Peripheral Processor

NSVC Network Service Virtual Connection



Appendix A - Abbreviations



NSVCI Network Service Virtual Connection Identifier

P

POWB POWer B

POWP POWer P

PUC Packet Unit Controller

PS Packet Switching

PSTN Public Switching Telephone Network

S

SMB Subrate Multiplexing to Bts

SMEM Share MEMory

SMPP Subchannel Multiplexing Peripheral Processor

SYCK SYnchronous ClocK board

T

TC Trans Coder

TIC Trunk Interface Circuit

TMM Transport Management Module




A p p e n d i x

B

Figures

Figure 1 - Location Update.................................................45 Figure 2 - Call Flow...........................................................47 Figure 3 - External Handover .............................................57 Figure 4 - Connection Failure .............................................67 Figure 5 - Assignment (Intra-Cell Handover) Timeout ............68 Figure 6 - Intra-BSC/Inter-BSC Handover Timeout ................68 Figure 7 - Position of Gb Interface in GPRS Network ..............99 Figure 8 - Composition of Gb Interface Protocol Stack.......... 100 Figure 9 - Clock Signal Flows (No Submultiplexing) ............. 105 Figure 10 - Clock Signal Flows (Submultiplexing) ................ 106 Figure 11 - Overall Hardware Structure of ZXG10-BSC (V2).. 115




Tables

Table 1 - Chapter Summary................................................ xi Table 2 - Typographical Conventions .................................. xiv Table 3 - Mouse Operation Conventions .............................. xiv Table 4 -General Safety Symbols..........................................1 Table 5 - Rate under CS Coding Scheme..............................96 Table 6 - Rate under MCS Coding Scheme............................96 Table 7 - Troubleshooting Records for Voice Faults.............. 112 Table 8 - Board List ........................................................ 116

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