7.OWN000301 RAN Troubleshooting ISSUE4.1

HUAWEI TECHNOLOGIES CO., LTD.

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RAN Troubleshooting

HUAWEI TECHNOLOGIES CO., LTD. Page 2All rights reserved

This training mainly provides the basic

methods to locate common faults of

RAN


Chapter 1 Troubleshooting OverviewChapter 1 Troubleshooting Overview

Chapter 2 Interface TroubleshootingChapter 2 Interface Troubleshooting

Chapter 3 Cell TroubleshootingChapter 3 Cell Troubleshooting


Troubleshooting Overview

General Flows of Troubleshooting

Start

End

Collect faultinformation

Locate the fault

Definite the fault

Clear the fault

Verify the fault



Step 1: Information collection:

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

indicators

Observe board indicators and alarm

management system on the LMT or

M2000

Area and impact of the fault

Perform service test, performance

measurement, and interface and

signaling tracing



Step 2: Fault Definition:

RAN faults

Loading faultsLoading faults

Service faultsService faults

Cell faultsCell faults

CS faultsCS faults

PS faultsPS faults

Interface link faultsInterface link faults

Clock faultsClock faults

RF performance faultsRF performance faults

Functional subsystem faultsFunctional subsystem faults

Access faultsAccess faults

Handover faultsHandover faults

O&M faultsO&M faults



Step 3: Fault Locating

Locating faults in the functional subsystem

− Troubleshoot these faults in compliance with the indicator information, alarm handli

ng suggestions, or error prompts

Locating faults in services

− For faults in voice services or packet switched services

− Check the Iu, Iub, and Uu interfaces

− Check the RNP/RNO parameters

− For faults in handover or access to the network

− Start the signaling tracing and comparing it with the protocols



Common Fault Location Methods

Alarm Analysis

Comparison or Replacement

Interface Signaling and User Tracing

Switch Over or Reset

Traffic Measurement

Test Analysis


Troubleshooting Overview Step 4: Fault Clearing

Methods to clear the faults and recover the system

− Replacing the cables, replacing boards, updating configuration data,

switching over system and resetting boards

− Different procedures should be applied to different faults

Step 5: Fault Verifying

Check the states of board indicators and alarm box indicators, and perform

dialing test

Review the whole troubleshooting process, note down the key points in the

troubleshooting, and summarize the workaround and methods for improvement

to avoid recurrence of the faults of the same type






Interface Troubleshooting

Iub interface protocolIub interface protocol

Control Plane

Transport NetworkControl Plane

User planeRadioNetworkLayer

Q.AAL2

Transport Network User Plane

TransportNetworkLayer


NCP CCP

A B C

CCP

NBAP

SAAL UNI AAL2PATH

ATM

Physical Layer

Q.2150.2

Q.2630.1

SAAL UNISCTP

IP

DLL

FP

IP

DLL

UDP



Iu-CS interface protIu-CS interface protocolocol

Control Plane



Q.AAL2




A B C

RANAP

AAL2 PATH

ATM

Physical Layer

Q.2150.1Q.2630.1

SAAL NNI

SCCP

MTP3-B

A

Iu UP

SAAL NNI

MTP3-BB



Iu-PS interface protIu-PS interface protocolocol

Control Plane






A C

RANAP

ATM

SAAL NNI

SCCP

MTP3-B

A

Iu UP

B

AAL Type 5

IP

UDP

GTP-U

Physical Layer

ATM

Physical Layer

C



Alarms of Physical Layer Faults E1/T1 fault alarms

− ALM-1101 E1/T1 Loss of Signal

− ALM-1001 IMA Link Loss Of Frame

− ALM-1007 IMA/UNI Link Loss of Cell Delineation

− ALM-1011 IMA Group Activated Links Insufficient

STM-1 fault alarms

− ALM-901 Optical Port Loss of Signal

− ALM-903 Optical Port Loss of Frame



Alarms of Data Link Layer Faults FE fault alarms

− ALM-851 FE Link Down

− ALM-852 FE Link Send Defect Indication

PPP link alarms

− ALM-2602 PPP/MLPPP Link Down

− ALM-2604 MLPPP Group Down



Alarms of Signaling link Faults SAAL link alarms

− ALM-1801 SAAL (NNI) Link Alignment Failed

− ALM-1802 SAAL Link Unavailable SCTP link alarms

− ALM-1851 SCTP Link Down

− ALM-1852 SCTP link congest

MTP3-B link alarms

− ALM-1413 MTP-3b Signalling Link Unavailable

− ALM-1403 MTP-3b DSP Inaccessible

NCP/CCP alarms

− ALM-2010 NCP Faulty

− ALM-2011 CCP Faulty



Alarms of Control Plane Faults QAAL2 alarms

− ALM-1601 QAAL2 PDU Mandatory Parameters Absent

− ALM-1602 QAAL2 Receives Unknown Message

− ALM-1618 QAAL2 Protocol Version Mismatch

− ALM-1615 AAL2 Adjacent Node Unavailable



Alarms of User Plane Faults AAL2PATH alarms

− ALM-1603 AAL2 Path Blocked By Peer End

− ALM-1605 AAL2 Path Reset By Peer End

IP PATH alarms

− ALM-2606 IP PATH Down

GTP-U alarms

− ALM-1901 Path to SGSN Faulty

− ALM-1902 Link to SGSN Fault



Points of Processing Alarms 1, Alarms would be classified according to sources

2, Cell alarms may come from transport or hardware faults

3, Alarms in high layer come from the faults in lower layer in transport

4, Most alarms in transport come from physical faults


Troubleshooting CaseUnavailable E1/T1 Physical Links

Symptom and Fault Definition

After you run the DSP E1T1 command on the RNC LMT to check the state of the E1/T1 links, Link running state is any of the following:

− Loss of Signal

ALM-1101 E1/T1 Loss Of Signal

− Loss of Frame

ALM-1102 E1/T1 Loss Of Frame

− Remote Alarm

ALM-1103 E1/T1 Remote Alarm Indication

− Loss of Multiple Frame

ALM-1105 E1/T1 Loss Of Multiframe

− Fault


Troubleshooting CaseUnavailable E1/T1 Physical Links

Fault Locating and Clearing

If Link running state is one of those previous introduction except Fault, handle the fault according to the Alarm Handling in the online help

If the Link running state is Fault ,then do the loopback test of E1/T1 and recover the faulty E1/T1 cables


Troubleshooting CaseUnavailable E1/T1 Physical Links Loopback test of E1/T1 from RNC

Step 1: local port loopback to check the E1/T1 ports in RNC

− SET E1T1LOP, LOP E1T1, SET E1T1LOP

Step 2: physical local loopback to check the local cables in RNC

− Connect the TX end with the RX end of the E1/T1 at the local end

− LOP E1T1

− Cancel the loopback at the local end

Step 3: physical remote loopback to check the transmission in RNC

− Connect the TX end with the RX end of the E1/T1 at the remote end

− LOP E1T1

− Cancel the loopback at the remote end

Step 4: remote port loopback to check the E1/T1 ports at the remote end

− SET E1T1LOP(peer end), LOP E1T1(RNC LMT), SET E1T1LOP(peer end)

Step 5:reset the IMA group

− RST IMAGRP


TX

RX

TX

RX

Step 1: Local Loop Back>> SET E1T1LOP (Loop type=local)>> LOP E1T1 (Activate loop)>> SET E1T1LOP (Loop type=noloop)

Step 2: Physical local loop back>> LOP E1T1 (RNC LMT)

Loopback Test of E1/T1 from RNC

Troubleshooting CaseUnavailable E1/T1 Physical LinksTroubleshooting CaseUnavailable E1/T1 Physical Links

RNC

NodeB

Step 3: Physical remote loop back >> LOP E1T1 (RNC LMT)

Step 4: Remote Loop Back >> SET E1T1LOP (peer end:Loop type=remote)>> LOP E1T1 (RNC LMT:Activate loop)>> SET E1T1LOP (peer end:Loop type=noloop)

Step 5: Reset IMA group>> RST IMAGRP


Troubleshooting CaseUnavailable E1/T1 Physical Links Loopback test of E1/T1 from NodeB

Step 1: local port loopback to check the E1/T1 ports in NodeB

− SET E1T1LOP, DSP E1T1, SET E1T1LOP

Step 2: physical local loopback to check the local cables in NodeB

− Connect the TX end with the RX end of the E1/T1 at the local end

− DSP E1T1

− Cancel the loopback at the local end

Step 3: physical remote loopback to check the transmission in NodeB

− Connect the TX end with the RX end of the E1/T1 at the remote end

− DSP E1T1

− Cancel the loopback at the remote end

Step 4: remote port loopback to check the E1/T1 ports at the remote end

− SET E1T1LOP(peer end), DSP E1T1(NodeB LMT), SET E1T1LOP(peer end)

Step 5:reset the IMA group

− RST IMAGRP


TX

RX

TX

RX

Step 4: Remote Loop Back>> SET E1T1LOP (peer end:Loop type=remote)>> DSP E1T1 (NodeB LMT:Activate loop)>> SET E1T1LOP (peer end:Loop type=noloop)

Step 3: Physical remote loop back>> DSP E1T1 (NodeB LMT)

Loopback Test of E1/T1 from NodeB

Troubleshooting Case Unavailable E1/T1 Physical LinksTroubleshooting Case Unavailable E1/T1 Physical Links

RNC

NodeB

Step 2: Physical local loop back >> DSP E1T1 (NodeB LMT)

Step 1: Local Loop Back >> SET E1T1LOP (Loop type=local)>> DSP E1T1 (Activate loop)>> SET E1T1LOP (Loop type=noloop)

Step 5: Reset IMA group>> RST IMAGRP






Cell Setup Procedure

NBAP_AUDIT_REQ

NBAP_AUDIT_RSP

NBAP_CELL_SETUP_REQ

NBAP_CELL_SETUP_RSP

NBAP_COMM_TRANSP_CH_SETUP_REQ

NBAP_COMM_TRANSP_CH_SETUP_RSP

NBAP_SYS_INFO_UPDATE_REQ

NBAP_SYS_INFO_UPDATE_RSP

LOCELL, CELL, CCP

CELL ID, Frequency,

Power

Setup Common

Channels ：1 、 PRACH 、 AI

CH

2 、 SCCPCH 、PICH

NBAP_COMM_TRANSP_CH_SETUP_REQ

NBAP_COMM_TRANSP_CH_SETUP_RSP


Cell Troubleshooting

Alarms of Cell Setup Failure ALM-2036 NodeB Audit No Rsp

ALM-2012 Cell Setup Failed

ALM-2014 Common Channel Setup Failed

ALM-2032 Cell Max DL power mismatch

ALM-2027 Cell HSDPA Setup Failed

ALM-2006 Cell Unavailable

ALM-2030 Cell HSDPA Unavailable


Troubleshooting Case

Cell Setup Is Not Initiated After the Audit Process Ends

Fault Symptom and Definition

− Cell setup is not started after the audit process ends

Fault Locating

− Execute the LST CELL command

− The result shows that the cell data is available, so cell setup is all

owed

− The corresponding LocalCell ID can be obtained

− The NBAP_AUDIT_RSP message includes the corresponding LocalC

ell information. The max TX power supported by LocalCell is 370 (37

dBm)


Troubleshooting Case

Cell Setup Is Not Initiated After the Audit Process End

Fault Locating

− Execute the LST CELL command. The result shows that th

e max TX power configured for the cell is 430 (43 dBm), wh

ich is greater than that supported by LocalCell. That is, the t

wo power settings are inconsistent

Fault Clearing and Verifying

It is checked that the max TX power 370 reported by the NodeB is correct

Reduce the max transmit power of the cell by MOD CELL and modify the power threshold of PCPICH by MOD PCPICHPWR in RNC LMT

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7.OWN000301 RAN Troubleshooting ISSUE4.1