06 NodeB Troubleshooting

7/22/2019 06 NodeB Troubleshooting

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NodeB Troubleshooting


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HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 1

References

RAN Troubleshooting Cases

SUPPORT.HUAWEI.COM


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

Know how to find NodeB faults

Grasp NodeB troubleshooting methods

Know the common trace and log collection methods.


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Chapter 1 General Introduction

Chapter 2 Typical Cases

Chapter 3 Trace and Log Collection


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General Trouble-shooting Procedure


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The Ways to Find Faults

Alarm

Alarm console

Alarm box

OMC Shell

Traffic statistics

Drive test

Routine inspection

Customer complaint


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Information Collection

Fault symptoms, occurrence time, place and frequency

Fault coverage, category and associated consequences

Equipment running status before occurrence of a fault

Operations done on the equipment and the corresponding operating results

Alarms occurring when a fault takes place

Board indicator status when a fault occurs

Software version information and log information when a fault occurs

Signaling and internal tracing result when a fault occurs

Measures taken to handle the fault and the corresponding effect


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If RNC has fault, usually it will affect some sites or all of sites

If NodeB has fault, usually it just affect itself and the handover

successful rate of adjacent cells

During implementation or expansion, we can Interchange

NodeB and judge the fault is because of RNC or NodeB

During maintenance, RNC faults dont just affect one NodeB

Locating and Clearing Faults


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Common Fault Types

RAN fault

Cell

Traffic

Link

Interconnection

Clock

Antenna & Feeder

transmission

Operation and maintenance fault

OMC

Software Loading

RNO fault

Access

Call drop

Congestion

Handover


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Basic Troubleshooting Methods (1)

For Simple Fault

Analyzing the Alarm Information and the Indicator status

Comparison/Interchange

For Complex Fault

Analyzing Apparatus and Meter Test Result

Tracing the Interface, Traffic Test

Analyzing Traffic Statistics Result

For Restoring System

Switching/Resetting


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Analyzing the Alarm Information

Alarm information comes from the RAN alarm system, indicated

usually through sound, light, LED, and screen output, etc

It includes the detailed description of the abnormality, possiblecauses and restoration suggestions, involving the hardware, link,

trunk and CPU loading ratio, etc

Analyzing the Indicator Status

Indicators display the work status of circuit, link, optical path,node and active/standby mode besides that of the

corresponding boards,

Usually used along with the alarm information


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Comparison/Interchange

Comparison:

compare the faulty components or symptoms with the normal

ones, and find the difference

Interchange:

if the fault can not be located even after the standby components

are replaced, you can interchange the normal components (such

as board, optical fiber, etc.) with the potential faulty components

and to compare the work status


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Analyzing Apparatus & Meter Test Result

It reflects the fault nature with the visual and quantified data

Some common Apparatus & Meter

Signaling Analyzer, Test phone, Sitemaster, etc.

Tracing the Interface

It is applied in locating the failure causes of subscriber call

connection and inter-office signaling cooperation, etc

The trace result can help to find the cause of call failure directly and

locate the problem or to get the index for the subsequent analysis


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Traffic Test

It is a simple and quick method to judge whether the call processing

function and relative modules of the RAN are normal or not

Analyzing Traffic Statistics Result

It is the most useful method for locating RNO fault.


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Switching/Resetting

It can not locate the fault cause accurately, and due to the

randomness of software running, the fault may be not able to recur,

thus it is difficult to know the real fault and solve the problem

This method is just an emergency method, so applicable only in the

emergency situation


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Verifying Troubleshooting Result

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 andmethods for improvement to avoid the recurrence of the faults of

the same type


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Case 1: Abnormal RTWP

Case 2: Failure to Establish Cells

Case 3: Failure to Deliver the License of the NodeB Through M2000


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Symptom: Abnormal RTWP value is observed

RTWP > 102 dBm continuously

RTWP < 110 dBm continuously

RTWP reaches to a peak value, e.g.

80 dBm intermittently


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RTWP background knowledge

RTWP: Received Total Wideband Power, see TS25.215 for definition

NodeB periodically measures RTWP to evaluate the UL interference level,

measurement reference point: Rx antenna connector

Normal Value: -106dBm 4dB


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RTWP abnormality troubleshooting procedure

If Abnormally High

Configuration issue:

Check the uplink RF sensitivityvalue. Must be set to 0

DSP RFDESPARAM and DSP DESENS

Check the attenuation value of the Rx channel

May caused by missing configuration of RXATTEN parameter

while TMA is available. You need to set the RXATTEN value

according to the gain of the TMA. SET RXATTEN = TMA gainFeeder Loss

Hardware installation issue

Check whether passive TX/RX inter-modulation occurs


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If Abnormally High

UL interference issue

Check if it is caused by neighboring cell interference

Long time real time monitoring

Describe the RTWP symptom (continuously, in rush hours, or

intermittently) and RTWP value range.

Check if it is related to subscribers' behaviors

Real time monitoring on RNC for the number of cell usernumber, to see whether a large number of high-speed packet

subscribers access the system.


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If Abnormally Low

Configuration issue:

Check the attenuation value of the Rx channel

Confirm TMA is available or not, if no TMA, no need to configureRXATTEN

Hardware installation issue

Check the installation of the antenna feeder


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Collect the following traces to R&D personnel if the problem still there


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Cell establishment failure includes 2 scenarios

Local cell establishment failure

ALM-4033 Local Cell Unusable issued at NodeB side

Logical cell establishment failure

ALM-2012 Cell Setup Failed at the RNC side.


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Background Knowledge

Mapping between Local Cell and Logical Cell

NodeB: Site => Sector => Local Cell (linking with Local Cell ID)

=> RNC: Local cell => Logical Cell

If the local cells at the NodeB side are not available, theestablishment of logical cells fails.

Cell establishment failure includes local cell establishment failure and

logical cell establishment failure. When local cells fail to be established,

there is a user alarm that local cells are not available at the NodeB side.When logical cells fail to be established, there is an alarm that cell

establishment fails at the RNC side.


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Failure to Establish Local Cells

Configuration issues:

The local cell type should be consistent with the type of the

corresponding sector.


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The baseband resources of the uplink/downlink resource group to

which the cells belong should be enough to be allocated to the cells

Type of Board Uplink Capability (cells) Downlink Capability (cells)

NBBI 3 3

HBBI 3 3

HBBU 3 3

HULP 3 /

HDLP / 6

EBBC 3 6

EBBI 6 6

EULP 6 /

WBBPb 6 6


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Configuration issues:Cell receivingantenna should be configured while the sectorsare

established


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Configuration issues:Cell transmittingantenna should be configured when local cellsare

established.


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The configuration of the cell transmitting antenna should agree with the

transmitting diversity mode in the sector configuration.


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If multiple cells are established on a RRU link, ensure that the IQ

resources on the RRU link are enough to be allocated.


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Configuration issues: The maximum transmit power of cells and uplink/downlink frequency

should match the RF hardware attributes. You can run the DSP RRUTC

MML command to view the RF hardware attributes.


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BBU issues

Run the DSP LOCELL command to query the cell status. If the result

displays baseband resource fault,

Check whether there exists an alarm about the baseband board hardware.

The possible reasons are as follows:

The baseband board hardware related to the cell is faulty.

The resources of the resource group to which the cell belongs are

exhausted, so no resources are available to be allocated to the cell.


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BBU issues

The baseband board related to the cell is blocked => UBL BRD


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BBU issues

The baseband board related to the cell is disconnected. Iub link is OK if

the NCP and CCP port status are Normal


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RRU issues

Run the DSP LOCELL command to query the cell status. If the result

displays RF resource fault,


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RRU issues

Check whether a hardware alarm occurs to the baseband board. The

possible reasons are listed as follows:

The RF board hardware related to the cell is faulty, for example, the RRU

hardware is faulty.

The carries carried by the RF unit related to the cell are limited, for

example, the 40W MRRU supports two carriers. If a third carrier is

established, cell establishment fails. => Query the RF hardware capability

by DSP RRUTC

The RF board related to the cell is blocked. => UBL BRD


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RRU issues

The RF board related to the cell is disconnected from the baseband board

You need to check whether the optical module and fiber connection are

normal.


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Failure to Establish Logical Cells

Check whether the logical cells are configured correctly

The transmission configuration at the RNC side should be

consistent with that at the NodeB side, for example, the VPI

and VCI of the AAL2PATH;


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Example: RNC side transmission configuration


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Example: Compare with NodeB side Transmission

Configuration


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Check whether the logical cells are configured correctly

The maximum transmit power of logical cells should be

equal to or lower than that of local cells;

The cell parameter configuration at the RNC side should be

consistent with that at the NodeB side.


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Query the failure reason by running the DSP CELLcommand at the RNC side

When the establishment of logical cells still fails even if

the configurations are correct, provide a feedback of

the related information to the R&D department for

analysis.


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Information Collection List to R&D personnel


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Case 3: Failure to Deliver the License of the

NodeB Through M2000

When the License of the NodeB is delivered on the M2000, the

M2000 interface shows the failure of the delivery.

When you run the DSP LICENSEcommand on the NodeB to

query the License status, the result shows the status of the original

License.


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Troubleshooting Procedure

Failure to Deliver the Licenses of All NodeB Sites

Check whether the connections between the M2000 and the NodeB

sites are normal, and check whether these NodeB sites are in normal

state in the main topology.

Attempt to deliver the licenses again.


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Failure to Deliver the Licenses of Some the NodeB Sites

Check whether the connections between the M2000 and the NodeB

sites are normal, and check whether these NodeB sites are in normal

state in the main topology.

Attempt to deliver the licenses again.


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Failure to Deliver the Licenses of Some the NodeB Sites

Right-click the faulty the NodeB process, and select Detail from the

shortcut menu. Usually, you can determine the fault reason or the

incorrectly configured control item


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Meaning of part of common control items

UL CE Quantity of channel elements for processing in Up link (a number

divisible by 16)

DL CE Quantity of channel elements for processing in Down link (a number

divisible by 16)

Local Cell Quantity of configured Local Cells on NodeB

HSDPA Enabling of HSDPA function ( 1enable , 0disable)

HSDPA RRM Enabling of HSDPA RRM function ( 1enable , 0disable)

HS-PDSCH Code Quantity of High Speed PDSCH Code for all cells on NodeB

HSUPA Enabling of HSUPA function ( 1enable , 0disable)

PA[47,8dBm] Quantity of configured Cells on NodeB with max Power 47,8 dBm


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Checking the license control items

Check whether the number of downlink/uplink CEs exceeds the limit

allowed by the License,

Check whether the configured number of local cells is smaller than the

actual one.


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Checking the license control items

If the HSUPA control item in the License is enabled, check whether

the HSUPA function of the BTS is enabled by running the LST

BRDHSUPAcommand on the LMT. If the HSUPA function of the BTS

is not enabled, enable the HSUPA function by running the SETBRDHSUPAcommand.

PA[XXDbm] refers to the maximum number of local cells when the

maximum transmit power does not exceed XXDbm. If the NodeB has

a 46-dBm cell and the control item delivered by the License is 43 dBm,

the delivery fails. It is the first control item that may be ignored.


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Information Collection to R&D stuff if still unsolved


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Chapter 1 General Introduction


Chapter 3 Trace and Log Collection


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Collecting NodeB Fault Location Data

Type of NodeB Fault Location Data

NodeB Main Board Logs

NodeB Board Logs

Signaling Tracing Messages on the Iub Interface


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Collecting NodeB Main Board Log via NodeB LMT


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Collecting NodeB Main Board Log via M2000

Choose Software Browser.


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Then, select NEon the left pane and select the

corresponding NodeB site in the list.


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Then, the right pane displays the corresponding tab.

To upload the main control log, click Other, select

MAINBRDLOG, and click Upload To NMat the right lower

corner.


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Set the name of the log to be uploaded (use the format of Site name +

date to discriminate the file from the previously downloaded files), and

tick Compress Upload(reduce the time of file upload).


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Then, the main control log of The NodeB is uploaded to the M2000

server. Select the NM Servertab, and then select an appropriate NodeB

site.


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To upload a log file, select Other. The list below displays the name and

site of the log file uploaded to the M2000 server. Find and select the

uploaded log file from the list.

Click the right Transferbutton, select From NM to Client, and set the

upload path on the local PC. Then, the selected log file is uploaded to

the local PC.


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Collecting NodeB Board Log via NodeB LMT


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Collecting Signaling Tracing Messages on the Iub Interface via NodeB LMT


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06 NodeB Troubleshooting