03 guide to precautions and emergency measures of lte high-volume traffic-v2.0

Guide to Precautions and Emergency Measures of LTE High-Volume Traffic

Issue 2.0

Date 2013-01-31

HUAWEI TECHNOLOGIES CO., LTD.

INTERNAL

Copyright © Huawei Technologies Co., Ltd. 2012. All rights reserved.

No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.

Trademarks and Permissions

and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd.

All other trademarks and trade names mentioned in this document are the property of their respective holders.

Notice

The purchased products, services and features are stipulated by the contract made between Huawei and the customer. All or part of the products, services and features described in this document may not be within the purchase scope or the usage scope. Unless otherwise specified in the contract, all statements, information, and recommendations in this document are provided "AS IS" without warranties, guarantees or representations of any kind, either express or implied.

The information in this document is subject to change without notice. Every effort has been made in the preparation of this document to ensure accuracy of the contents, but all statements, information, and recommendations in this document do not constitute a warranty of any kind, express or implied.

Huawei Technologies Co., Ltd.

Address: Huawei Industrial Base

Bantian, Longgang

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People's Republic of China

Website: http://www.huawei.com

Email: [email protected]

Issue 2.0 (2013-01-31) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co.,

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Guide to Precautions and Emergency Measures of LTE High-Volume Traffic About This Document

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About This Document

Author

Prepared by LTE key events assurance team

Date 2012-12-18

Reviewed by Date

Reviewed by Date

Approved by Date

Change History

Date Version

Description Author

2013-1-30 1.7 kanzhenggang


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Guide to Precautions and Emergency Measures of LTE High-Volume Traffic Contents

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Contents

About This Document........................................................................ii

1 Introduction..................................................................................1

2 Preparation Before Festivals..........................................................22.1 License Application...........................................................................................................................................2

2.2 SCTP Link Configuration..................................................................................................................................2

2.3 Site TAC Adjustment.........................................................................................................................................2

2.4 Site Type Adjustment.........................................................................................................................................2

3 Data Configuration Backup.............................................................3

4 Suggestions to Parameter Adjustment Before Attended Support Services...........................................................................................4

4.1 Adjustment of EPC Parameters..........................................................................................................................4

4.1.1 Adjustment of TAU Timers......................................................................................................................4

4.1.2 Adjustment of Paging Parameters.............................................................................................................5

4.2 Adjust the T302 timer........................................................................................................................................5

4.3 SRI resources automatic adjustment programs..................................................................................................6

4.4 PUCCH resources automatic adjustment programs...........................................................................................6

4.5 CQI cycle automatic adjustment programs........................................................................................................6

4.6 SRS resources automatic adjustment programs.................................................................................................7

4.7 User plane Flow Control programs....................................................................................................................7

4.8 Adjustment of the Inter-Frequency Load Balance Switch.................................................................................8

4.9 Adjustment of the UL PreAllocation Switch.....................................................................................................8

4.10 Management Plane OAM flow control measures............................................................................................9

5 Emergency Handling Measures in Event-based Attended Support Services.........................................................................................10

5.1 Emergency Handling Procedure......................................................................................................................10

5.1.1 Preparing the Operation Record.............................................................................................................10

5.1.2 Saving MML Command Output to a File...............................................................................................10

5.1.3 Recording 15-min Traffic Measurement Results....................................................................................11

5.1.4 Setting KPI Alarm Thresholds................................................................................................................11

5.1.5 Reference Values for KPI Thresholds.....................................................................................................15

5.1.6 Important Alarms....................................................................................................................................15


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Guide to Precautions and Emergency Measures of LTE High-Volume Traffic Contents

INTERNAL5.2 KPI Faults........................................................................................................................................................15

5.2.1 Problem symptom:..................................................................................................................................15

5.2.2 Emergency measures:.............................................................................................................................16

5.3 SCTP Link Congestion....................................................................................................................................16

5.3.1 Problem symptom:..................................................................................................................................16


5.4 License-Restricted Paging (for eRAN3.0 Only)..............................................................................................17

5.4.1 Problem symptom:..................................................................................................................................17


5.5 Failure in Rectifying Long-Term MME Overload...........................................................................................17

5.5.1 Problem symptom:..................................................................................................................................17


5.6 Board Overload................................................................................................................................................18

5.6.1 Problem symptom:..................................................................................................................................18


5.7 the number of cell users increased abnormal...................................................................................................20

5.7.1 Problem symptom:..................................................................................................................................20


5.8 Inter RAT reselection parameter adjustment based on load.............................................................................21

5.8.1 Problem symptom:..................................................................................................................................21


5.9 Sleeping Cell....................................................................................................................................................21

5.9.1 Problem symptom:..................................................................................................................................21


6 Restoring Data Configuration.........................................................................22


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Guide to Precautions and Emergency Measures of LTE High-Volume Traffic 1 Introduction

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1 Introduction

This document provides guidance to handle with the scenario with traffic surge for the purpose of ensuring normal running of the network. This helps avoid impact on eNodeBs and evolved packet core (EPC) from concentrated population and traffic surge in festivals and gathering activities, such as deterioration of the paging success rate, access success rate, and traffic volume.

Risks from high-volume traffic occur in the following three scenarios:

At special moments similar to 0:00 in the new year's eve

In competition venues of the World Cup, F1 racing, or Olympics, with a large population to cause substantial traffic growth in hot spots

In scenarios similar to the new year's eve rally. The traffic volume substantially increases in hot spots and also on the entire network.


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Guide to Precautions and Emergency Measures of LTE High-Volume Traffic 2 Preparation Before Festivals

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2 Preparation Before Festivals

2.1 License ApplicationFor key security projects of Huawei (such as the World Cup concerned by all parties and with holiday assurance services purchased), it is proposed that, before assurance activities start, temporary commercial licenses be applied for or the capacity of commercial licenses is expanded based on the capacity evaluation results. Access can be rejected if the traffic volume exceeds the license capacity.

2.2 SCTP Link ConfigurationTo mitigate impact on services in case of an EPC fault or overload, it is recommended that one eNodeB connects to multiple MMEs through S1-MME links in the LTE system. Multiple MMEs form an MME pool to use the multi-MME S1-Flex scheme.

For details, see S1-Flex Feature Parameter Description.

2.3 Site TAC AdjustmentTracking area code (TAC) adjustment is used to avoid excessive track area update (TAU) messages caused by mobility of the tracking area edge users and reduce TAU procedures and signaling impact. It is recommended that a high-volume traffic site be planned in the same tracing area with neighboring sites.

After the tracing area information of the operator is modified, cells correlated with the TAC are automatically reset for reestablishment. (For details, run the MOD CNOPERATORTA command to query TAC values of various cells.) You are advised to modify tracking area information in idle hours.

2.4 Site Type AdjustmentIt is recommended that one cell be configured in one site or one cell be configured on one LBBP to ensure user experience in scenarios with high-volume traffic.


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Guide to Precautions and Emergency Measures of LTE High-Volume Traffic 3 Data Configuration Backup

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3 Data Configuration Backup

Modification described in this document is based on scenarios with high-volume traffic surge. Before parameters are modified, we must back up current data configuration. After the traffic surge, configuration of eNodeBs and the EPC must be restored.

In addition, parameters before and after modification, LTE main processing and transmission unit (LMPT) logs, LTE baseband processing unit (LBBP) logs, and traffic measurement data before and after traffic surge must be stored to facilitate fault location in case of a fault. Data configuration backup can also help prevent insufficient data caused by untimely data saving when a fault occurs.

Data configuration and collected logs can be backed up by using the M2000 or Web LMT. You are advised to use the M2000 to back up data one day before modification.

Traffic measurement data is obtained from the M2000. For details about required counters, see Information Collection Checklist for LTE Key Events. (back up data one day before modification)


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4 Suggestions to Parameter Adjustment Before AttendedSupport Services

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4 Suggestions to Parameter

Adjustment Before Attended Support Services

Follow optimization suggestions in this chapter to adjust parameters and run each MML command in an interval of 10s. Do not run MML command in batches. Manually reset the eNodeB after all parameters are adjusted.

4.1 Adjustment of EPC Parameters

4.1.1 Adjustment of TAU Timers [Modification Cause]

The periodical TAU timer (T3412) and mobility reachability timer are used to manage the period for a UE to initiate the periodical TAU.

It is recommended that T3412 be changed to 180 min and the mobility reachability timer to 184 min.

These parameters must be negotiated with the EPC (MME) before modification and must be restored after the assurance activity. Huawei EPC optimization can use the following command. For parameter optimization for the EPC provided by other manufactures, the field technical support personnel must discuss with the operator.

[Advantage]

In traffic surge scenarios, the TAU-related timers can be prolonged to reduce processing signaling of the eNodeB and EPC.

[Impact]

No evident impact is detected.

[MML command]

SET EMM: T3412=180, RCHTMR=184;


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INTERNAL[Applicable Version]

Huawei EPC: USN9810 V900R011C00SPC100 and later versions

4.1.2 Adjustment of Paging Parameters [Modification Cause]

If a UE is paged but does not respond, the EPC initiates paging for a maximum of three times. Huawei USN9810 can use the paging flow control command to limit the paging to only once in case of no response from the UE, reducing impact from excessive paging signaling. It is recommended that the paging flow control switch be turned on.

These parameters must be negotiated with the EPC (MME) before modification and must be restored after the assurance activity. Huawei EPC optimization can use the preceding commands. For parameter optimization for the EPC provided by other manufactures, the field technical support personnel must discuss with the operator.

[Advantage]

After the paging flow control switch is turned on, only one paging is initiated in case of a paging failure caused by manually removing the user service identity module (USIM) card and high-volume traffic, reducing the signaling load.

[Impact]

No evident impact is detected.

[MML command]

SET EMMPROCTRL: STOPPAGING= 1;

[Applicable Version]

Huawei EPC: USN9810 V900R011C00SPC100 and later versions

4.2 Adjust the T302 timer[Modification Cause]

If network congestion occurs, the eNodeB rejects the RRC connection setup request and the UE resends an RRC connection setup request. In case of network congestion, the UE attempts to send the request repeatedly in a short interval; that does not help clearance of network congestion. It is suggested that the T302 is set to a larger value to prolong the time for request resending after the RRC connection setup is rejected.

[Advantage]

In high-volume traffic scenarios, if network congestion occurs, the time for the UE to wait for access is prolonged after the RRC connection setup is rejected, preventing the UE from rapidly resending a request to stop the system from clear congestion. The parameter modification applies to instantaneously high-volume traffic cells, for example, stands.

[Impact]

There is no impact on the eNodeB performance.

[MML command]


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INTERNALMOD RRCCONNSTATETIMER: T302=16;


eRAN2.1, eRAN2.2, eRAN3.0

4.3 SRI resources automatic adjustment programs

[Modification Cause]

To avoid the limited resources of the SRI (Scheduling Request Indication) fails, advise to open SRI adaptive switch;

[Advantage]

Adjustment of resource allocation can be automatically initiated when SRI lack of resources or resource surplus.

[Impact]

Close SRI adaptive switch, the maximum capacity of the cell for 20 * SRI cycle (default 10ms), may be ahead of the congestion risk.

[MML command]

MOD GLOBALPROCSWITCH: SriAdaptiveSwitch=ON;



4.4 PUCCH resources automatic adjustment programs


It is recommended that the physical uplink control channel (PUCCH) dynamic algorithm switch be turned on to avoid UE access failures caused by limited PUCCH resources.

[Advantage]

If this switch is set to on, resources are automatically adjusted when the PUCCH resources are insufficient or excessive.

[Impact]

Close PUCCH switch, the cell capacity is about the (10 +4 * SRI cycle), may be ahead of the congestion risk.

[MML command]

MOD CELLALGOSWITCH: LocalCellId=x, PucchAlgoSwitch=PucchSwitch-1;




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4.5 CQI cycle automatic adjustment programs[Modification Cause]

To avoid the CQI limited resources and the user access failure, advise to open CQI resources dynamically adjust switch;

[Advantage]

The system will be based on the number of users of the scheduling, the CQI resource automatically extended function to meet the user CQI resource allocation.

[Impact]

Close the CQI cycle switch, the user-level CQI cycle can not be less than 40ms.Cell capacity is about 18 *CQI cycle.

[MML command]

MOD CQIADAPTIVECFG: CqiPeriodAdaptive=ON;


eRAN3.0 and after version

4.6 SRS resources automatic adjustment programs


It is recommended that the sounding reference signals (SRS) dynamic algorithm switch be turned on to avoid UE access failures caused by limited SRS resources.

[Advantage]

If this switch is set to on, the algorithm dynamically adjusts the SRS subframe configuration based on the usage of cell resources.

[Impact]

SRS cycle adaptive switch is turned off, the capacity is calculated as:

Maximum capacity = TTI actual support the the SRS number of users * SRS cycle

[MML command]

MOD SRSADAPTIVECFG: SrsPeriodAdaptive=ON;

4.7 User plane Flow Control programs[Modification Cause]

For downlink data services in high-volume traffic scenarios, excessively large packet per second (PPS) and bits per second (BPS) exceed the LBBP processing capability, resulting in packet loss and even cell reestablishment and LBBP reset.


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INTERNAL[Advantage]

The downlink PPS/BPS flow control scheme can help prevent high-priority packets from being discarded and avoid critical faults such as cell reestablishment and LBBP reset.

[Impact]


[MML command]

SET DLITFCALG: BCDLITFCSW=ON, PCDLITFCSW=ON;



4.8 Adjustment of the Inter-Frequency Load Balance Switch


If the existing network in different frequency adjacent area network, in a different neighborhood interval adjustment of the load, it is recommended to open different frequency load balancing; different frequency adjacent areas networking, it is recommended to close the different frequency load balancing algorithm switch.

[Advantage]

This switch reduces signaling exchange.

[Impact]


[MML command]

MOD CELLALGOSWITCH: MlbAlgoSwitch=InterFreqMlbSwitch-1;


eRAN3.0 and after version

4.9 Adjustment of the UL PreAllocation Switch[Modification Cause]

Indicates whether to enable or disable preallocation, which shortens the end-to-end delay of services when the UL load is light. If preallocation is enabled, the probability of UEs entering DRX is relatively low and therefore the service time of the UEs is relatively short.Advise to close the switch.

[Advantage]

Close preallocation switch, eNodeB is not active send ulgrant request to UE. Reduce signaling surface resource consumption;


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INTERNAL[Impact]


[MML command]

MOD CELLALGOSWITCH: LocalCellId=x, UlSchSwitch=PreAllocationSwitch-0;


eRAN2.1, eRAN2.2

4.10 Management Plane OAM flow control measures

[Modification Method]

Reduce or turn off the actions about the software upgrade, upload and download the logs, signaling trace, MML batch operations.Avoid to cause the CPU resource Utilization increases.


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5 Emergency Handling Measures in Event-based AttendedSupport Services

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5 Emergency Handling Measures

in Event-based Attended Support Services

5.1 Emergency Handling Procedure

5.1.1 Preparing the Operation RecordAn operation record must be printed onsite to specify the operation time and detailed operation contents, including all emergency handling procedures for the hardware and software.

5.1.2 Saving MML Command Output to a File

Method 1:

Right-click the command output on the M2000 and choose Report Redirection from the shortcut menu, and then set the save path and file name.

If the MML command window is closed during command execution, the configuration is invalid. In this case, you need to reopen the MML window, set parameters, and then execute the command.


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Method 2:

Log in to the Web LMT locally or from the M2000; on the Common Maintenance tab page, select the check box of Save Result. In the displayed Save dialog box, set the save path and file name to save the command output.

Obtain the MML_Result_YYYY-MM-DD-HH-MM-SS.txt file in the save path and then query the command and command output.

5.1.3 Recording 15-min Traffic Measurement ResultsBefore the peak traffic arrives, arrange in advance to record the subsequent 15-min traffic measurement result.


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INTERNALFor details about the traffic measurement counters and formulas for eNodeB monitoring, see the LTE Attended Support Service Checklist.

5.1.4 Setting KPI Alarm ThresholdsStep 1 Create an alarm. Log in to the M2000, and choose Performance > Threshold Management

> Alarm Name Setting.

Step 2 In the displayed Alarm Name Setting window, enter a new alarm name.

The following figure shows that the new alarm is successfully added.


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Step 3 Set corresponding KPI thresholds of the new alarm. Choose Performance > Threshold Management > Threshold Setting.

Step 4 In the displayed Threshold Setting window, select the KPI type to be checked from the navigation tree on the left.

Step 5 Right-click in the right pane and choose Add from the shortcut menu.

Step 6 In the displayed Add Threshold window, choose the NE to be monitored (all NEs recommended for the SOP) on the Basic Threshold Information tab page, enter a threshold name, and correlate to the new alarm.


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Step 7 Choose the KPI item to be monitored, KPI deteriorating direction (Increasing or Decreasing), and thresholds for different-severity alarms on the Extended Threshold Information tab page.


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Step 8 Click OK.

Step 9 Choose Monitor > Browse Alarm List to check whether an alarm is generated.

5.1.5 Reference Values for KPI Thresholds

Item Appendix Description

Reference values for KPI threshold settings

See the Network KPI Monitoring sheet in LTE Attended Support Service Checklist.

Alarm thresholds may vary, depending on the site. Values in the checklist are for reference only.


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5.1.6 Important AlarmsFor details about important alarms, see LTE Attended Support Service Checklist.

5.2 KPI Faults

5.2.1 Problem symptom:A KPI fault occurs if any of the following conditions is satisfied.

1. The RRC connection setup success rate lower than 80%. or

2. If the E-RAB setup success rate lower than 80%. or

3. The call drop rate higher than 10%.

Analyze problem symptoms and rules by checking the fault occurrence range, in individual cells, eNodeBs, or areas. If the fault occurs in an area, check whether intermittent transmission interruption or EPC overload occur.

5.2.2 Emergency measures: 1. Check for related alarms. If no alarm is generated, send traffic measurement KPIs and

logs of the LMPT and LBBP to the R&D personnel for immediate analysis.

2. If related alarms are generated, clear the alarms by referring to the alarm help. Then, query KPIs. If the KPIs do not change, send traffic measurement KPIs and logs of the LMPT and LBBP to the R&D personnel for immediate analysis.

3. If ALM-25889 SCTP Link Congestion alarm is generated, handle the fault by referring to section SCTP Link Congestion.

4. If ALM-26812 System Exceeding Licensed Capacity Limit is generated, handle the fault by referring to section License-Restricted Paging (for eRAN3.0 Only).

5. Run the command to check whether the EPC is overloaded. If the EPC is overloaded, handle the problem by referring to section Failure in Rectifying Long-Term MME Overload.

5.3 SCTP Link Congestion

5.3.1 Problem symptom:The SCTP link is congested if the following conditions are satisfied.

1. The access success rate or E-RAB setup success rate lower than 90%. And

2. ALM-25889 SCTP Link Congestion alarm is generated but cannot be cleared for a long period or repeatedly occurs.

5.3.2 Emergency measures: 1. Check whether the QoS value in the message is appropriate and modify the value if

inappropriate. You are advised to set the signaling priority DSCP value to be larger than or equal to 46.

[MML command]:


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INTERNALLST DIFPRI;

SET DIFPRI:PRIRULE=DSCP, SIGPRI=46;

2. Followed in order to make the SCTP link congestion resume as soon as possible, reduce the type of mo-data and mo-sig the RRC access frequency.

[MML command]:

MOD CELLALGOSWITCH: AcBarAlgoSwitch=ACBAR_SWITCH_STATIC;

MOD CELLACBAR: LocalCellId=*, AcBarringInfoCfgInd=CFG, AcBarringForMoDataCfgInd=CFG, AcBarringFactorForCall=P70, AcBarTimeForCall=ACCESS_BARRING_TIME_S8, AcBarringForMoSigCfgInd=CFG, AcBarringFactorForSig=P70, AcBarTimeForSig=ACCESS_BARRING_TIME_S16;

3. Reduce the reference signal power for faulty cells in batches to mitigate traffic impact on coverage. It is recommended that the reference signal power be set to a value that is obtained by substracting 3 dB each time from the original value to view the effect.

MML command:

MOD PDSCHCFG: LocalCellId=x, ReferenceSignalPwr=182 (152, 122, 92) , Pb=0;

MOD CELLDLPCPDSCHPA: LocalCellId=0, PaPcOff=DB0_P_A;

For details about the modification range, obtain the PDSCH information from the eNodeB MO reference documents unpacked from the .rar package under Release Documents at http://support.huawei.com.

4. If the SCTP link congestion persists after the preceding operations, try to prohibit cells in SCTP link congestion one by one and check whether congestion is cleared. If it is cleared, restore the cell state.

MML command:

MOD CELLACCESS: LocalCellId=x, CellBarred=CELL_BARRED;

5.4 License-Restricted Paging (for eRAN3.0 Only)

5.4.1 Problem symptom:1. The RRC connection setup success rate or E-RAB setup success rate lower than 90%.

And

2. ALM-26812 System Exceeding Licensed Capacity Limit is generated.

5.4.2 Emergency measures: 1. If an emergency license has been applied, you are advised to install the license on the

M2000.

2. If an emergency license has not been applied, you are advised to turn on the grace period switch. After this command is successfully executed, an NE enters the emergency license state. In this case, dynamic resources are allocated in maximum configuration mode, static resources and functions are configured according to the formal license. The emergency license state can maintain for seven days. Each NE can enter the emergency license state for three times at most.

MML command:

SET LICENSECTRL


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5.5 Failure in Rectifying Long-Term MME Overload

5.5.1 Problem symptom:1. The E-RAB setup success rate lower than 90%. And

2. The DSP S1INTERFACE command output shows that S1 Interface state and S1 SCTP Link State are abnormal or MME is overloaded is True.

5.5.2 Emergency measures: 1. Perform overload flow control on the EPC.

2. If the problem persists, prohibit low-priority services and set the cell state to new user prohibited on the wireless side under the premise that most users can perform services properly. Restore the cell state after MME congestion is cleared.

MML commands:

MOD CELLACBAR; (in the order from high priority to low priority of the user type set by the operator)

MOD CELLACCESS: LocalCellId=0, CellBarred=CELL_BARRED;

3. If the MME overload or congestion persists after the preceding operations, run the BLK CELL command to block cells in batches. Run the UBL CELL command to unblock the cells after MME congestion is cleared.

5.6 Board Overload

5.6.1 Problem symptom:Board overload is classified into LMPT overload and LBBP overload. If a board overload alarm is automatically cleared in a minute, back up board logs and send the logs to the R&D personnel for analysis after the attended support service is complete. If a board overload alarm is not automatically cleared in a minute, take the measures described in this section.

Board overload occurs if any of the following conditions is satisfied.


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INTERNAL1. ALM-26202 Board Overload is generated (query the slot number to check whether the

alarm is for the LMPT or LBBP).

2. The traffic measurement result on the M2000 shows a CPU usage of larger than 80%.

3. The DSP CPUUSAGE command output shows a CPU usage of larger than 80% (this command applies to eRAN2.2 and a later version).

5.6.2 Emergency measures: I. LMPT Overload

Perform steps 1 to 2 simultaneously. If board overload persists, perform steps 3 to 7.

1. Reduce unnecessary traffic measurement reports and only retain basic traffic reports including:

CPU usage

RRC connection setup counters: L.RRC.ConnReq.Msg, L.RRC.ConnReq.Att, and L.RRC.ConnSetup.

E-RAB setup counters (L.E-RAB.SuccEst and L.E-RAB.AttEst)

Number of users in a cell (L.Traffic.User.Avg and L.Traffic.User.Max)

E-RAB release counters (L.E-RAB.AbnormRel and L.E-RAB.NormRel)

Set the reporting period for the preceding traffic measurement to a large value (every one hour).

2. Reduce or stop other real-time monitoring and tracing tasks of a cell.

3. Decrease access rate of the mo-data and mo-sig RRC attach request on eNodeB.

MML commands:


4. Modify T302 Timer.

MOD RRCCONNSTATETIMER: T302=16;

5. Adjust the reference signal power of a cell to shrink the cell coverage and have some UEs hand over to cells of another eNodeB. Adjust the reference signal power at a step of 3 dB each time from the original value to view the effect.

MML command:

MOD PDSCHCFG: LocalCellId=x, ReferenceSignalPwr=182 (152, 122, 92) , Pb=0;

MOD CELLDLPCPDSCHPA: LocalCellId=0, PaPcOff=DB0_P_A;

6. If board overload persists, set the cell state to new user prohibited to ensure existing services in the cell.

MML command:

MOD CELLACCESS: LocalCellId=x, CellBarred=CELL_BARRED);

II. LBBP Overload

1. Reduce the Reference signal to shrink the coverage range and mitigate traffic impact. It is recommended that the reference signal power be set to a value that is obtained by substracting 3 dB each time from the original value to view the effect.

MML command:


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mk:@MSITStore:C:%5CDocuments%20and%20Settings%5Cz00152836%5C%E6%A1%8C%E9%9D%A2%5Clte-pfm-reference_20110713.chm::/lte/lte-enodeb-performance-counter-reference/MtType_300.html


mk:@MSITStore:C:%5CDocuments%20and%20Settings%5Cz00152836%5C%E6%A1%8C%E9%9D%A2%5Clte-pfm-reference_20110713.chm::/lte/lte-enodeb-performance-counter-reference/MT_L_Traffic_User_Max.html

mk:@MSITStore:C:%5CDocuments%20and%20Settings%5Cz00152836%5C%E6%A1%8C%E9%9D%A2%5Clte-pfm-reference_20110713.chm::/lte/lte-enodeb-performance-counter-reference/MT_L_Traffic_User_Avg.html








INTERNALMOD PDSCHCFG: LocalCellId=x, ReferenceSignalPwr=xx;

For details about the modification range, obtain the PDSCH information from the eNodeB MO reference documents unpacked from the .rar package under Release Documents at http://support.huawei.com.

2. If the overload is not clear, reduce mo-data and type of mo-sig the RRC access frequency.

MML commands:


3. If board overload persists, set the cell state to new user prohibited to ensure existing services in the cell.

MML command:

MOD CELLACCESS: LocalCellId=x, CellBarred=CELL_BARRED;

4. If board overload persists, add high-load boards and reduce the number of cells in a single LMPT and LBBP in the case with cell coverage unchanged.

5.7 the number of cell users increased abnormal

5.7.1 Problem symptom:The maximum number of cell users of the single-cell growth more than 30 within 15 minutes, and the maximum number of cell users reached 250.

5.7.2 Emergency measures:I. Reduce the type of mo-data and mo-sig the RRC access frequency. Reduce the number

of users to simultaneously access.

[MML command]:



II. When the maximum number of cell users reached about 300, the the ACBAR threshold is adjusted to 50%.

[MML command]:


MOD CELLACBAR: LocalCellId=*, AcBarringInfoCfgInd=CFG, AcBarringForMoDataCfgInd=CFG, AcBarringFactorForCall=P50, AcBarTimeForCall=ACCESS_BARRING_TIME_S8,


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INTERNALAcBarringForMoSigCfgInd=CFG, AcBarringFactorForSig=P50, AcBarTimeForSig=ACCESS_BARRING_TIME_S16;

5.8 Inter RAT reselection parameter adjustment based on load

5.8.1 Problem symptom:CSFB success rate is lower than 85%, and the maximum number of cell users reached 200.

5.8.2 Emergency measures:When high load occurs and the CSFB succ rate has deteriorated in LTE, Change the L2U reselection threshold to make some UEs reselection to UMTS.

[MML command]:

LTE side：MOD CELLRESEL: LocalCellId=1, ThrshServLow=10; (5->10) ;

UMTS side：MOD UCELLNFREQPRIOINFO: CellId=13708, ThdToHigh=14;(9->14)

5.9 Sleeping Cell

5.9.1 Problem symptom:Check the KPI on M2000:

msg1 = (L.RA.GrpA.Att + L.RA.GrpB.Att + L.RA.Dedicate.Att + L.RA.Dedicate.HO.Att)

msg2 = (L.RA.GrpA.Resp + L.RA.GrpB.Resp + L.RA.Dedicate.Resp + L.RA.Dedicate.HO.Resp)

msg3 = L.RRC.ConnReq.Att

If msg1>500，msg2 or msg3=0, then this cell will be a sleeping cell.

5.9.2 Emergency measures:Reset LBBP or reset the eNodeB, the service will be interrupted for about 5 minutes.


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Guide to Precautions and Emergency Measures of LTE High-Volume Traffic 6 Restoring Data Configuration

6 Restoring Data Configuration

After the attended support services for key events are complete, restore all data configuration.


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