RNC Troubleshooting

UTRAN Trainning – Troubleshooting 2012

BSC68-69 Series 1

General Introduction to

BSC 6900 Operation and

Maintenance


BSC68-69 Series 2

FOREWORD

• This training mainly provides the elementary methods and methods to locate common faults of RNC

Page3

CONTENTS

1. Troubleshooting Overview

2. Collecting Fault Location Data

3. Troubleshooting Cases

Page4


BSC68-69 Series 3

TROUBLESHOOTING OVERVIEW

Page5

• RAN Troubleshooting Process


Page6

• Step 1: Collecting Fault Information

Information Item Collection Method

Fault symptoms, as well as the

occurrence time, place, frequency

Consult the customer service

center

Running state of the equipment,

operations and related results before the

fault occurrence, and measures taken

afterwards

Consult the O&M staff

Alarms and associated alarms, states of

board LEDs

Observe board indicators and

alarm management system on

the LMT

Area and impact of the fault

Perform service demonstration,

performance measurement, and

interface and signaling tracing


BSC68-69 Series 4


Page7

• Step 2: Defining Fault Area and Type

RAN faults

Service faults

Functional subsystem faults

VP faults

PS faults

Interface link faults

Clock faults

RF performance faults

Access faults

Handover faults

Voice faults


Page8

• Step 3: Diagnosing Fault Causes(1)

– Locating faults in the functional subsystem

• Troubleshoot these faults through board LEDs (which will blink abnormally), alarms, and error prompts

– Locating faults in services

• For faults in voice services or packet switched services

– check the Iu, Iub, and Uu interfaces in turn and then determine whether the fault occurs to the RAN based on the symptoms on the interface

– If the fault occurs to the internal component of the RAN, you should further locate it

• For faults in handover or access to the network

– start the signaling tracing and comparing it with the protocols to locate the fault


BSC68-69 Series 5


Page9

• Step 3: Diagnosing Fault Causes (2)

– Common Fault Location Methods

• user tracing

• interface signaling tracing

• traffic measurement

• alarm analysis

• test analysis

• network packet catchers

• comparison and double replacement

• GENEX series tools and OMStar


Page10

• Step 4: Clearing the Fault

– Checking the cables, replacing the boards, modifying the data configuration, switching over the systems, and resetting the boards

– Different procedures should be applied to different faults

– Reviewing the whole troubleshooting process

• Step 5: Checking the Equipment or Services

– Checking whether the system works properly by querying the states of board LEDs and alarm LEDs

– Performing dialing test to ensure that the services are operational


BSC68-69 Series 6


Page11

• Step 6: Contacting Huawei for Technical Support

– Collect necessary fault information and contact Huawei for technical support

– Huawei Contact Information

• Telephone: (86-755) 28560000

• Fax: (86-755) 28560111

• E-mail: [email protected]

• Website: http://support.huawei.com

CONTENTS




Page12

mailto:[email protected]

http://support.huawei.com/


BSC68-69 Series 7

COLLECTING RNC FAULT LOCATION DATA

Page13

• Types of RNC Fault Location Data

– Error logs from the RNC FAM

– RNC alarm data

– Error logs from a BAM server

– Operation Logs

– RNC Self-Diagnostic Output Data

– Call Data Record (CDR)

– Signaling tracing messages

– RNC configuration data


Page14

• Collecting Error logs from the RNC FAM

– Collecting text log files

• The file path is BSC6800 Installation Directory BAM\Common\Famlog\fmt

• File format: FNLOGyyyymmddhhmmss_yyyymmddhhmmss.log.zip

– FN: subrack number, 2 digits

– yyyy: year mm: month dd: day hh: hour mm: minute ss: second

– Collecting CHR data (Call History Record)

• The file path is BSC6800 Installation Directory

BAM\Common\Famlog\txt

• File format: FNLOGyyyymmddhhmmss_yyyymmddhhmmss.log.zip


BSC68-69 Series 8


Page15

• Collecting RNC alarm data

– The past and present RNC alarm data are recorded on the LMT, which indicates the running or changing status of the RNC

– Open the Alarm Browse window and select the fault alarms. Right-click and select Save All Alarms. Save them as .txt files

• Collecting Error logs from a BAM server

– Error logs from a BAM server include the event logs, SQL Server logs, and BAM module running logs

– Run the COL LOG command on the LMT, the log file name and file path will be displayed


Page16

• Collecting Operation Logs

– Run the EXP LOG command on the LMT

– The generated file is saved in BAM main eara path\FTP

– The file is named as RNC-Y2008M01D09H13N01S52-Y2008M05D09H13N02S09-OLOG.txt

• Collecting RNC Self-Diagnostic Output Data

– Running the TST SYS command on the LMT, the system can

automatically detect the fault in the devices or signaling links

– The self-diagnostic result is saved in the BAM in \LOADDATA\FAD on the BAM server

WRBS self-diagnostic file: WRBS**FadResultYYYY-MMDD-HH-

MM.txt

WRSS self-diagnostic file: WRSS**FADRESULTYYYY-MMDD-HH-

MM.txt


BSC68-69 Series 9


Page17

• Collecting Call Data Tracing Message (CDT)

– Start the LMT and click the Maintenance tab in the left pane. Select CDT

– When the CDT tracing window is displayed, enter the IMSI number in the IMSI box. Click OK to start tracing

– Call the UE to obtain the call detail message

• The message can be automatically saved as a file on the LMT under a constant directory


Page18

• Collecting Signaling tracing messages on standard interface

– Trace the messages on standard interfaces on the LMT

– Save the messages in the file under the LMT installation directory

• Collecting RNC configuration data

– Run the EXP CFGMML command on the LMT

– The generated file is saved in BAM main area path\FTP

– The default file is named as CFGMML-YYYYMMDDHHMMSS.txt


BSC68-69 Series 10

PUSH-BUTTON RNC DATA COLLECTION

Page19

• Push-Button RNC Data Collection Guidelines

– Run the COL LOG command on the LMT

– The returned messages include the file path and file name for saving fault data

CONTENTS




Page20


BSC68-69 Series 11

TROUBLESHOOTING CASES

Page21

• Refer to Product Manual of <RAN Troubleshooting Guide>


BSC68-69 Series 12

OBJECTIVES

• Upon completion of this course, you will be able to:

– Describe RAN troubleshooting process

– Outline E1/T1 fault typical handling

– Outline FE/GE fault typical handling

Page23

CONTENTS


2. E1/T1 Fault Troubleshooting

3. FE/GE Fault Troubleshooting

Page24


BSC68-69 Series 13

RAN TROUBLESHOOTING PROCESS

Page25

Start

Collecting fault information

Determining the fault area and types

Diagnosing fault causes

Clearing the faults

The services

are resotred?

End

Contacting Huawei for

Technical Support

Yes

No

COLLECTING FAULT INFORMATION

Page26

• Fault symptoms

• Time, location, and frequency

• Area and impact

• Running status of the equipment before a fault occurs

• Operations and related results before a fault occurs

• Measures and related effects after a fault occurs

• Alarms and associated alarms when a fault occurs

• States of board LEDs when a fault occurs


BSC68-69 Series 14

DETERMINING THE FAULT AREA AND TYPE

Page27

RAN faults

Faults in servicesFaults in the

functional subsystem

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DIAGNOSING FAULT CAUSES

Page28

• Locating faults in the functional subsystem

– Base on LED information, alarm handling suggestions, or error prompts

• Locating faults in services

– CS or PS service fault

• Check the Iu, Iub, and Uu interfaces

• Check the RNP/RNO parameters

– Handover or access fault

• Start the signaling tracing and comparing it with the protocols


BSC68-69 Series 15

CLEARING AND VERIFYING THE FAULT

Page29

• Clearing the Fault

– Modifying the data configuration

– Switching over the systems

– Checking the cables

– Replacing the boards

• Verifying the Fault

– After the faults clearing, check LEDs and alarms, and perform dialing test to ensure that the services are operational

HUAWEI TECHNICAL SUPPORT

Page30

• Telephone: 0086-755-28560000

• Fax: 0086-755-28560111

• E-mail: [email protected]

• Website: http://support.huawei.com

mailto:[email protected]

http://support.huawei.com/


BSC68-69 Series 16

QUESTIONS

Page31

1. How to collect fault information? please list at least 3 ways.

2. How to get the product manual of latest version?

3. Some customers complain that it is very hard to make a success call at about 11:00~12:00 AM, and these complains just occurs in a small area. Based on the information, what will you do?

CONTENTS




Page32


BSC68-69 Series 17

CONTENTS


2.1 E1/T1 Overview

2.2 E1/T1 Typical Fault

2.3 E1/T1 Fault Typical Handling

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Metallic shield

Plastic jacket

Dielectric isolator

Centre core

E1/T1 OVERVIEW

Page34

• Bit rate: 2048kbit/s

• Impedance:

– 120 ohm, balance, twisted pair cable

– 75 ohm, unbalance, coaxial cable

• Line code:HDB3 or AMI

• Frame structure:

– CRC4 Multi Frame

– Double Frame

• Scramble Switch: On or Off


BSC68-69 Series 18

CONTENTS


2.1 E1/T1 Overview



Page35

E1/T1 TYPICAL FAULT

Page36

• Configuration Mismatch (Frame Structure, Line Code, Scramble)

• Impedance Fault (E1/T1 mode DIP Switch, grounding)

• Physical Connection Fault (wrong connection, cross connection)

• Transmission Quality Fault (Bit Error Rate Too High, Excessive Slip Frames)


BSC68-69 Series 19

PHYSICAL CONNECTION FAULT

Page42

L1_TX

L1_RX

L2_TX

L2_RX

L1_RX

L1_TX

L2_RX

L2_TX

B1

B2

A

L1_TX

L1_RX

L2_TX

L2_RX

A

L1_RX

L1_TX

L2_RX

L2_TX

B1

B2

CONTENTS


2.1 E1/T1 Overview



Page43


BSC68-69 Series 20

E1/T1 FAULT TYPICAL HANDLING

Page44

• Querying Alarm

• Querying E1/T1 State

• Loop back

• Offline Test

• Online Test (Only for NodeB)

QUERYING E1/T1 STATE

Page45

• NodeB side, DSP E1T1 to query: – E1/T1 link running state

• RNC side, DSP E1T1 to query: – link running state, link type, loop back type

– line impedance

– clock mode

– TX frame format, expected RX frame format

– TX line coding mode, RX line coding mode

– Error count


BSC68-69 Series 21

LOOP BACK

Page46

• SET E1T1LOP

– NOLOOP

– REMOTE

– LOCAL

L1_RX

L1_TXB

L1_TX

L1_RXA

L1_RX

L1_TXB

L1_TX

L1_RXA

L1_RX

L1_TXB

L1_TX

L1_RXA

Note:

Figures show

the states

when MML is

executed on

“A” side

ONLINE TEST (ONLY FOR NODEB)

Page47

• NodeB: STR E1T1ONLTST

– Not interruption to service

– Applicable to line with bit errors but free from faults

– If the Periodical Report Switch is "OFF", the test result will be reported only after the STR E1T1ONLTST is executed

• NodeB: STP E1T1ONLTST


BSC68-69 Series 22

OFFLINE TEST

Page49

Mode1:

1. RNC: SET E1T1LOP (REMOTE)

2. NodeB: STR E1T1OFFLTST

3. NodeB: STP E1T1OFFLTST

RX

TX

TX

RX

RNC NodeB

RX

TX

TX

RX

RNC NodeB

Success

Failed

BER=20%

Note: DO NOT forget to stop E1T1 test! DO NOT forget to set loopback as NOLOOP after the test!

OFFLINE TEST

Page51

Mode2

1. NodeB: SET E1T1LOP (REMOTE)

2. RNC: STR E1T1TST

3. RNC: DSP E1T1TST

4. RNC: STP E1T1TST

Note: DO NOT forget to stop E1T1 test!

DO NOT forget to set loopback as NOLOOP after the test!

RX

TX

TX

RX

NodeB RNC

RX

TX

TX

RX

NodeB RNC


BSC68-69 Series 23

E1/T1 FAULT HANDLING PRINCIPLE

Page53

• Query first, Handling second

• Loop back first, Test second

• Online test first, Offline test second

• Far first, Near second

TX

RX

RNC

RX TX

TX RXA

RX TX

TX RXB

RX

TX

NodeB

TX

RX

RNC

RX TX

TX RXA

RX TX

TX RXB

RX

TX

NodeB

TX

RX

RNC

RX TX

TX RXA

RX TX

TX RXB

RX

TX

NodeB

TX

RX

RNC

RX TX

TX RXA

RX TX

TX RXB

RX

TX

NodeB

QUESTIONS

Page54

• Case1: There are 10 NodeB connect to a same RNC subrack, one of the NodeB has 4E1s, all the E1’s BER is too high to provide normal service, but other NodeBs’ transmission is normal. What kind of fault it is? How to handle the fault?

• Case2:In case1, for the NodeB, if just 1E1 is in high BER, and other E1s are normal. What kind of fault it is? How to handle the fault?


BSC68-69 Series 24

CONTENTS




Page55

FE/GE OVERVIEW

Page56

Straight Through

Cable Diagram

Crossover Cable

Diagram


BSC68-69 Series 25

BOARD WITH FE/GE

Page57

NodeB

3900

WMP

T

UTRP

2

UTRP

9

BSC681

0 FG2

FE/GE FAULT TYPICAL HANDLING

Page58

• Checking the cable and connector

• Checking the parameter of the FE

– MML: DSP ETHPORT , LST ETHPORT

• PING

• Fault Isolation PC connect to

NodeB, Check the

port alarm

PC connect to Peer,

Check PC’s ETH

LED

Alarm is cleared

LED is On

Peer faultYes

No

NodeB ETH port

fault. Use RST

ETHPORT and RST

BRD, check the chip

abnormal alrm

No

Yes


BSC68-69 Series 26

SUMMARY

• RAN Troubleshooting Process

• Typical Handling for E1/T1 Fault

• Typical Handling for FE/GE Fault

Page60

Documents

RNC Troubleshooting