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]
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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
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ZTE CORPORATIONValues Your Comments & Suggestions!
Your opinion is of great value and will help us improve the quality of our productdocumentation and offer better services to our customers.
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.
Thank you for your cooperation!
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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
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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
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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
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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
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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
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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
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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.
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ZXG10-BSC (V2.97) Base Station Controller Maintenance Manual (Troubleshooting)
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.
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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
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ZXG10-BSC (V2.97) Base Station Controller Maintenance Manual (Troubleshooting)
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
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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
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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.
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ZXG10-BSC (V2.97) Base Station Controller Maintenance Manual (Troubleshooting)
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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.
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Chapter 1 - Safety Instructions
Confidential and Proprietary Information of ZTE CORPORATION 3
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
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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
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Chapter 1 - Safety Instructions
Confidential and Proprietary Information of ZTE CORPORATION 5
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
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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
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Chapter 1 - Safety Instructions
Confidential and Proprietary Information of ZTE CORPORATION 7
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
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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.
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Chapter 1 - Safety Instructions
Confidential and Proprietary Information of ZTE CORPORATION 9
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.
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Confidential and Proprietary Information of ZTE CORPORATION 11
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
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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
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Chapter 2 - Maintenance Overview
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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
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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.
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Confidential and Proprietary Information of ZTE CORPORATION 15
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
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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
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Chapter 3 - Analyzing and Handling OMCR Faults
Confidential and Proprietary Information of ZTE CORPORATION 17
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
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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.
The fault may result from one of the following causes:
Configuration files ampcfg.ini and syscfg.ini are not
set correctly.
Environment variables $OMCHOME and $PATH are not set
correctly.
Files that share the memory are not deleted.
Fault occurs in communication between the systemprocesses.
The file system of the operating system is abnormal.
Disk is full.
Perform the following steps to troubleshoot the fault:
1. Check whether the server configuration file is correct,
including the following items:
In ampcfg.ini file, check whether MaxModule in [MODULE]
section equals to MaxLoad in [LOAD] section.
Precautions
Fault Symptom
Fault CauseAnalysis
Troubleshooting
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Chapter 3 - Analyzing and Handling OMCR Faults
Confidential and Proprietary Information of ZTE CORPORATION 19
In ampcfg.ini file, check whether MaxProcess in
[COMMON], [COM], [DB], and [AP] sections match theactual process list number of the section.
Whether the process map name in ampcfg.ini file
matches that in syscfg.ini file
Whether the process name in syscfg.ini file matches the
actual process name, and if the process exists
In ampcfg.ini file, check whether the value of
PsLoadTimeout in the [PARAMETER] section is too small.
2. Check whether the server environment variable settings arecorrect.
Log on the operating system as ’omc’ user and check
whether the .profile file contains following contents:
OMCHOME = /export/home/omcexport OMCHOME
LD_LIBRARY_PATH=$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.
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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
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Chapter 3 - Analyzing and Handling OMCR Faults
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Abnormal Startup of an IndividualProcess
An individual process of the server starts abnormally, forexample, the IMF process, AGT process, or DIF process.
The fault may result from one of the following causes:
The process itself is abnormal.
The process state machine has been killed by the AMPA.
The system communication is abnormal.
Perform the following steps to troubleshoot the fault:
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
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The fault may result from one of the following causes:
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
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Chapter 3 - Analyzing and Handling OMCR Faults
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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
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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.
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Chapter 3 - Analyzing and Handling OMCR Faults
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If the following error appears:
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
If the following error appears:
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.
The fault may result from one of the following causes:
Database connection fails.
Precautions
Fault Symptom
Fault CauseAnalysis
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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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 3 - Analyzing and Handling OMCR Faults
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Error Code Returned upon DIFInvocation
An error occurs upon DIF invocation, with an error code returned.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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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.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 3 - Analyzing and Handling OMCR Faults
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Security Management Faults
User Logon Failure
User fails to log on the client.
The fault may result from one of the following causes:
1. The server process is running abnormally.
2. The configuration file is incorrect.
3. The username or password is incorrect.
Perform the following steps to troubleshoot the fault:
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.
Perform the following steps to troubleshoot the fault:
1. Check if the user has adequate right.
Fault Symptom
Fault CauseAnalysis
Troubleshooting
Precautions
Fault Symptom
Fault CauseAnalysis
Troubleshooting
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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 fault may result from one of the following causes:
The command execution setting in the timer.dat file is
incorrect.
The command distribution fails.
Perform the following steps to troubleshoot the fault:
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
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Chapter 3 - Analyzing and Handling OMCR Faults
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The fault may result from one of the following causes:
Database connection fails.
Operation involves too many data, causing command
timeout.
Perform the following steps to troubleshoot the fault:
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.
The fault may result from one of the following causes:
Database rights of import/export operation are inconsistent.
Imported/exported table structures are inconsistent.
Data are in use.
Perform the following steps to troubleshoot the fault:
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
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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 fault may result from one of the following causes:
The client version differs from the server version.
Database information is incorrect.
Disk space of client or server is full.
Perform the following steps to troubleshoot the fault:
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
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Chapter 3 - Analyzing and Handling OMCR Faults
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None
Data Configuration Error
Client data configuration in Integrated ConfigurationEnvironment (ICE) tool has errors, including object creation,object deletion, or object modification, etc.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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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.
Perform the following steps to troubleshoot the fault:
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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 3 - Analyzing and Handling OMCR Faults
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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
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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.
Perform the following steps to troubleshoot the fault:
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
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The fault may result from one of the following causes:
Communication between foreground and background isabnormal.
Data of the foreground and the background are notconsistent.
Perform the following steps to troubleshoot the fault:
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.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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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.
The fault may result from one of the following causes:
Client and server do not have the same version.
Database information is incorrect.
Client or server has a full disk.
Perform the following steps to troubleshoot the fault:
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
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Chapter 3 - Analyzing and Handling OMCR Faults
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Alarm Faults
Real-time Alarms Report Abnormal
Upper-level NM fails to collect real-time alarms.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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.
Perform the following steps to troubleshoot the fault:
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
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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 fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 3 - Analyzing and Handling OMCR Faults
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Failure of Alarm Box Displaying Audio/Visual Alarms
The alarm box fails to display audio/visual alarms.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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 fault may result from one of the following causes:
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
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Perform the following steps to troubleshoot the fault:
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.
The fault may result from one of the following causes:
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
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Chapter 3 - Analyzing and Handling OMCR Faults
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Database is abnormal.
Perform the following steps to troubleshoot the fault:
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
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The fault may result from one of the following causes:
No EFRP board is configured.
The configuration information obtained is incorrect, without
EFRP board information. There is no EFRP LLC signaling.
Perform the following steps to troubleshoot the fault:
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
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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
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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
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Chapter 4 - Analyzing and Handling Access Faults
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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
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to MS. Instead, it directly returns the Assignment Fail
message to BSC.
The possible causes are:
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.
The possible causes are:
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
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Chapter 4 - Analyzing and Handling Access Faults
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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.
The fault may result from one of the following causes:
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
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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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 4 - Analyzing and Handling Access Faults
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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.
Perform the following steps to troubleshoot the fault:
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
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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.
The fault may result from one of the following causes:
Usually, it is due to SDCCH assignment failure.
MSC rejects the connection.
Perform the following steps to troubleshoot the fault:
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
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Chapter 4 - Analyzing and Handling Access Faults
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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.
Perform the following steps to troubleshoot the fault:
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 fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
Fault CauseAnalysis
Troubleshooting
Precautions
Fault Symptom
Fault CauseAnalysis
Troubleshooting
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Chapter 4 - Analyzing and Handling Access Faults
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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.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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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
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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
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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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 5 - Analyzing and Handling Handover Faults
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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 fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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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
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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.
Perform the following steps to troubleshoot the fault:
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
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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 fault may result from one of the following causes:
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
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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
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Chapter 6 - Analyzing and Handling Congestion Faults
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Perform the following steps to troubleshoot the fault:
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.
Perform the following steps to troubleshoot the fault:
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
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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
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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.
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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.
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Chapter 7 - Analyzing and Handling Call Drop Faults
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Call Drop due to Poor Coverage
Radio signals are poor and the call is disconnected during
conversation. Sometimes, metal clash sound can be heard.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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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.
Perform the following steps to troubleshoot the fault:
Precautions
Fault Symptom
Fault CauseAnalysis
Troubleshooting
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Chapter 7 - Analyzing and Handling Call Drop Faults
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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.
The fault may result from one of the following causes:
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
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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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 7 - Analyzing and Handling Call Drop Faults
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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.
The fault may result from one of the following causes:
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).
Perform the following steps to troubleshoot the fault:
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
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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
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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.
The fault may result from one of the following causes:
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
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Chapter 8 - Analyzing and Handling BSC Main Processor Faults
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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.
Perform the following steps to troubleshoot the fault:
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.
The fault may result from one of the following causes:
Abnormal flashing of the RUN indicator
Troubleshooting
Precautions
Fault Symptom
Fault CauseAnalysis
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Chapter 8 - Analyzing and Handling BSC Main Processor Faults
Confidential and Proprietary Information of ZTE CORPORATION 79
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 fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the 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
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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
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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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 9 - Analyzing and Handling BSC Data and Software Loading Faults
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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 fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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The fault may result from one of the following causes:
The BTS configuration is incorrect.
Fault exists in connection between BTS and BSC.
The channel is manually blocked.
Perform the following steps to troubleshoot the fault:
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.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 9 - Analyzing and Handling BSC Data and Software Loading Faults
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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 fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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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 fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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C h a p t e r
10
Analyzing and Handling A-Interface InterconnectionFaults
This chapter describes common procedures for analyzing and
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
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Chapter 10 - Analyzing and Handling A-Interface Interconnection Faults
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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.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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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
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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
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normal is one of the preconditions to guarantee the normal
packet data service.
BVC status is abnormal.
The fault may result from one of the following causes:
BRP blocking is not synchronized in the cell.
Cell reset is blocked.
BRP-Pn communication fault
Perform the following steps to troubleshoot the 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
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Chapter 11 - Analyzing and Handling Packet Data Service Faults
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PDCH status is abnormal.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the 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 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
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None
MS ATTACH Failure
MS ATTACH fails and the GPRS flag isn’t displayed on MS.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 11 - Analyzing and Handling Packet Data Service Faults
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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.
Perform the following steps to troubleshoot the fault:
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
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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
3 timeslots 15kbps 24kbps 27kbps 39kbps
4 timeslots 20kbps 32kbps 36kbps 52kbps
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
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Chapter 11 - Analyzing and Handling Packet Data Service Faults
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The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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12
Analyzing and HandlingGb InterfaceInterconnection Faults
This chapter describes common procedures for analyzing and
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
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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)
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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
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The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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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.
The fault may result from one of the following causes:
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.
Perform the following steps to troubleshoot the fault:
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
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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
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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)
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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
8Kframesynchronization
referencesignal
8Kframesynchronization
referencesignalBITSreferenceclock
The difference between the clock signal flows with
submultiplexing and that without submultiplexing is: The
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Chapter 13 - Analyzing and Handling Clock Faults
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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
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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
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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
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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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 14 - Analyzing and Handling Voice Faults
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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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 14 - Analyzing and Handling Voice Faults
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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.
The fault may result from one of the following causes:
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
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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.
Perform the following steps to troubleshoot the fault:
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
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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).
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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.
Perform the following steps to troubleshoot the fault:
Fault Symptom
Fault CauseAnalysis
Troubleshooting
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Chapter 15 - Analyzing and Handling Board Faults
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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.
Perform the following steps to troubleshoot the fault:
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
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END OF STEPS
Be sure to wear an antistatic wrist strap when touching a boardor component.
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.
Perform the following steps to troubleshoot the fault:
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
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Chapter 15 - Analyzing and Handling Board Faults
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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.
Perform the following steps to troubleshoot the fault:
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
Be sure to wear an antistatic wrist strap when touching a boardor component.
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
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Perform the following steps to troubleshoot the fault:
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
Be sure to wear an antistatic wrist strap when touching a boardor component.
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.
Perform the following steps to troubleshoot the fault:
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
Be sure to wear an antistatic wrist strap when touching a boardor component.
Troubleshooting
Precautions
Fault Symptom
Fault CauseAnalysis
Troubleshooting
Precautions
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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
Be sure to wear an antistatic wrist strap when touching a boardor component.
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.
Perform the following steps to troubleshoot the fault:
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
Be sure to wear an antistatic wrist strap when touching a boardor component.
Precautions
Fault Symptom
Fault CauseAnalysis
Troubleshooting
Precautions
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Chapter 15 - Analyzing and Handling Board Faults
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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.
Perform the following steps to troubleshoot the fault:
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
Be sure to wear an antistatic wrist strap when touching a boardor component.
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.
Perform the following steps to troubleshoot the fault:
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
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5. Reset the corresponding DSNI board and observe whether
the fault remains.
6. Replace the board if all steps above fail.
END OF STEPS
Be sure to wear an antistatic wrist strap when touching a board
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.
Perform the following steps to troubleshoot the fault:
1. Check whether the MTP2 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 MTP2 board and observe whether the fault remains.
4. Check whether the cable connection of the backplane is loose.
5. Reset the corresponding DSNI board and observe whetherthe fault remains.
6. Replace the board if all steps above fail.
END OF STEPS
Be sure to wear an antistatic wrist strap when touching a board
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
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Chapter 15 - Analyzing and Handling Board Faults
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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.
Perform the following steps to troubleshoot the fault:
1. Check whether the MON board is powered on or pluggedfirmly.
2. Check whether there is any alarm from the clock board. Ifthere is, troubleshoot the clock board fault first.
3. Reset the monitor board and observe whether the fault
remains.
4. Check whether the cable connection of the backplane is loose.
5. Replace the board if all steps above fail.
END OF STEPS
Be sure to wear an antistatic wrist strap when touching a board
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.
Perform the following steps to troubleshoot the fault:
1. Check whether the PEPD board is powered on or plugged
firmly.
Fault Symptom
Fault CauseAnalysis
Troubleshooting
Precautions
Fault Symptom
Fault CauseAnalysis
Troubleshooting
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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.
4. Replace the board if all steps above fail.
END OF STEPS
Be sure to wear an antistatic wrist strap when touching a boardor component.
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.
Perform the following steps to troubleshoot the fault:
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.
4. Check whether the cable connection of the backplane is looseor abnormal.
5. Replace the board if all steps above fail.
END OF STEPS
Be sure to wear an antistatic wrist strap when touching a boardor component.
MPMP Board Fault
Precautions
Fault Symptom
Fault CauseAnalysis
Troubleshooting
Precautions
Fault Symptom
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3. Reset the PCOM board and observe whether the fault
remains.
4. Check whether the cable connection of the backplane is looseor abnormal.
5. Replace the board if all steps above fail.
END OF STEPS
Be sure to wear an antistatic wrist strap when touching a boardor component.
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.
Perform the following steps to troubleshoot 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.
6. Replace the board if all steps above fail.
END OF STEPS
Be sure to wear an antistatic wrist strap when touching a boardor component.
Precautions
Fault Symptom
Fault CauseAnalysis
Troubleshooting
Precautions
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Chapter 15 - Analyzing and Handling Board Faults
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POWB Running Abnormal
POWB is running abnormally.
The hardware of the board or backplane is faulty.
Perform the following steps to troubleshoot the fault:
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.
Perform the following steps to troubleshoot the fault:
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
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Fan Running Abnormal
The fan is running abnormally.
The POWER P or fan is faulty in hardware or mechanics.
Perform the following steps to troubleshoot the fault:
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.
Perform the following steps to troubleshoot the 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
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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
Perform the following steps to troubleshoot the fault:
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
Perform the following steps to troubleshoot the fault:
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
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Confidential and Proprietary Information of ZTE CORPORATION 135
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
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Abbreviation Full Name
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
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Appendix A - Abbreviations
Confidential and Proprietary Information of ZTE CORPORATION 137
Abbreviation Full Name
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
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Confidential and Proprietary Information of ZTE CORPORATION 139
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
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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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