huawei signaling storm solution trial proposal

Signaling Storm Solution Trial Proposal

----FD & Cell PCH Feature Trial Deployment

Institute: Huawei Date

:

2012-5-1

Audit: Date

:

Authorize: Date

:

Huawei Technologies Co., Ltd.

All rights reserved

2012-06-27 HUAWEI Confidential Page I, Total 16

Signaling Storm Solution Trial Proposal Internal

Documentation Revision History

Version Date Updates description Author1.0 2012-04-25 Initial version

References

1. WCDMA RAN13.0 Feature Documentation

Glossary of Terms and Acronyms

Abbreviations Full spellingFD Fast Dormancy

2012-06-27 HUAWEI Confidential Page 2, Total 16


Contents

SIGNALING STORM SOLUTION TRIAL PROPOSAL ..................................................................I

1 APPLICATION SCOPE......................................................................................................................4

2 SIGNALING STORM SOLUTION...................................................................................................5

2.1 BACKGROUND...............................................................................................................................5

2.2 DESCRIPTION.................................................................................................................................6

3 TRIAL ENVIRONMENT REQUIREMENTS.................................................................................9

3.1 NETWORK ELEMENTS REQUIREMENTS..............................................................................9

1)RAN EQUIPMENT..............................................................................................................................9

2)SOFTWARE VERSION....................................................................................................................10

4 TRIAL PLAN.....................................................................................................................................10

5 SOLUTION IMPLEMENTATION..................................................................................................11

5.1 PARAMETER CONFIGURATION..............................................................................................11

1)CELL_PCH.........................................................................................................................................11

2)FD.........................................................................................................................................................11

5.2 IMPLEMENTATION.....................................................................................................................12

1)SECOND SCCPCH EXPAND IN OLD TRAFFORD CELLS......................................................12

2)THE TRANSMISSION FACTOR OF IUPS & IUB.......................................................................12

3)ENABLE CELL_PCH.......................................................................................................................12

4)ENABLE FD.......................................................................................................................................12

5)CORRELATIVE PARAMETER ADJUST......................................................................................13

5.3 EFFECT EVALUATE....................................................................................................................13

5.4 KPI MONITORING.......................................................................................................................15

5.5 KPI IMPACTS RISK ANALYSIS AND COUNTERMEASURES............................................16



1 Application Scope

This document describes the Field trial procedures for Huawei Signaling Storm Solution

which including Cell PCH and FD (Fast Dormancy) features.

This document is highly confidential and strictly to be used only by XXX Operator for the

sole purpose of understanding Huawei trial scheme. Information contained in this document shall

not be disclosed to any party unless it is expressly authorized by Huawei.



2 Signaling Storm Solution

2.1 Background

The number of 3G smartphones, such as iPhone, Blackberry, Nokia, and Android-based

smartphones, is increasing rapidly on Universal Mobile Telecommunications System (UMTS)

networks globally. Some applications embedded on smartphones, such as instant messaging and

mail applications, communicate with Internet servers frequently. These applications initiate a large

number of sessions in the packet switched (PS) domain in a short period and each session involves

a small amount of data. To reduce power consumption, some smartphones send a signaling

connection release indication (SCRI) message to the radio network controller (RNC) to release the

Radio Resource Control (RRC) connection after the communication with the server ends. In this

case, in each synchronization cycle, these smartphones will initiate an RRC request, synchronize

PS data, and release the RRC connection. Frequent RRC requests and releases generate a large

number of signals and cause signaling storms.

The large signaling traffic caused by smartphones consume considerable CPU resources on

the service process unit (SPU) board and PIU board of the RNC and the NodeB baseband board,

without bringing revenues to telecom operators. In addition, the RNC or NodeB CPU overload

occurs in some offices without proper measures, affecting the network capacity and stability.

To minimize the service impact of signaling storms on UMTS networks, smartphone

signaling storm solutions are developed.

The CELL_PCH, FD, and EFD solutions are provided in V900R012C01SPH226 and later

versions. The basic principle of these solutions is to migrate smartphone users to common

channels rather than releasing the RRC connection on the RNC side during the UE

synchronization intervals. In this case, when the next synchronization cycle begins, the UE does

not need to initiate new RRC and radio access bearer (RAB) access requests but initiates a cell

update instead, which reduces signaling process resource consumption on the radio access



network (RAN) system.

2.2 Description

The relative parameters of timer shown as below: Type MML Timer Description

Enable CELL_PC

H

SET

UUESTATE

TRANSTIM

ER

BEF2PSTATETRANSTI

MER

The default value is 65535, this value is too long, and it is equal to

close the F2P.

To enable CELL_PCH, the suggest value is 5 seconds.

BED2FSTATETRANSTI

MER

The default value is 5 seconds.

BEH2FSTATETRANSTI

MER


BEE2FSTATETRANSTI

MER


SET

UPSINACT

TIMER

PsInactTmrForInt The default value is 20, it means RNC will release this connection

after 20 seconds if no data transmission, this value is too short.


PsInactTmrForBac The default value is 20, it means RNC will release this connection

after 20 seconds if no data transmissionthis value is too short.


Enable R8FD

SET

UPSINACT

TIMER

PsInactTmrForFstDrmD

ch

The default value is 4, Suggest not changed.

PsInactTmrForFstDrmFa

ch

The default value is 5, Suggest not changed.

PsInactTmrForPreFstDr

m


To enable FD, the suggest value is 1800 seconds.

SET

UCONNMO

DETIMER

T323 The default value is INVALID to enable FD, the value must not

be INVALID, the suggest value is D120.

1) Default Setting

After a UE is inactive for a period, the UE is changed to the CELL_FACH state. If CELL_PCH not enabled, the UE is changed to IDLE state directly when the PsInactTmrForInt time expired.



2) CELL_PCH features activated

After a UE is inactive for a period, the UE is changed to the CELL_PCH state. When the UE

requests for data transmission, the data is transmitted in P2F2D2F2P or P2F2P mode. This reduces

signaling resource consumption and system resource consumption.

3) R8 FD activated

If the FD feature is disabled, the RNC releases the UE after the UE sends an SCRI message.

The UE enters idle state. When the UE changes to connection state, it needs to re-initiate an RRC

connection.

In the R8 FD solution, for an R8 UE with the cause "UE Requested PS Data Session End" in

the SCRI, its state is changed to the CELL_FACH state and then CELL_PCH after timer expired..

When the UE requests for data transmission, the data is transmitted in P2F2D2F2P or P2F2P



mode. This reduces signaling resource consumption and system resource consumption. For a UE

with other causes or without any causes in the SCRI, the connection is released directly and the

UE returns to the idle state.

UE in DCH state:

UE in FACH state:



3 Trial Environment Requirements

3.1 Network Elements Requirements

1) RAN Equipment

Table 1 Required RAN equipment

NE Equipment ID

RNC RNC722



2) Software Version

Table 2 Required software version

Product Feature Version

BSC6900 Cell_PCH BSC6900 V900R012C01SPC500 and later

version

BSC6900 R8FD BSC6900 V900R012C01SPH522 and later

version

4 Trial Plan

Trial area: RNC722

Trial plan:

Following table lists specific suggestions for the trial plan:

Phase Date Duration Case

Number

Content

Phase 1: preparationChoose RNC to switch

on Signaling storm

solution

2012/5/1 0.5 day

Phase 2: Prepare scriptParameter Prepare 2012/5/1 1 day Including the rollback script.Phase 3: ImplementParameter Execute 2012/5/3 1 dayPhase 4: KPI monitorMonitoring Network

KPIs

2012/5/3 1 week The changes on the number of PS

RAB connections, SPU and CE

service call drop rate, and combined

service proportion must be monitored

with emphasis.Phase 5: ReportSummary report 2012/5/10 3 days Complete analyze and give the report.



5 Solution implementation

5.1 Parameter Configuration

1) CELL_PCH

CELL_PCH inactivity timerParameter definition: When the UE has no PS data transmission for a configured period,

the PDCP layer requests the RRC layer to release the service connection. F2D 4A event threshold

Parameter definition: When the 4A event service traffic of the UE exceeds the configured threshold, the UE is transited from FACH/E_FACH to DCH/HSPA.

The recommended value is D1024. CELL_ DCH to CELL_ FACH transition timer

Parameter definition: When the UE initiating non-realtime services in the CELL_ DCH state is inactive for a configured period, the BE service of the UE is transited from the DCH state to the FACH state.

CELL_ FACH to CELL_PCH transition timerParameter definition: When the UE initiating non-realtime services in the CELL_ FACH

state is inactive for a configured period, the BE service of the UE is transited from the FACH state to the PCH state.

2) FD

For the CELL_PCH solution, configure the following parameters:

CELL_PCH inactivity timerParameter definition: When the FD UE in the CELL_PCH state has no data transmission

for the configured period, the PDCP layer requests the RRC layer to release the service connection.

CELL_ FACH inactivity timerParameter definition: When the FD UE in the CELL_ FACH state has no data

transmission for the configured period, the UE is transited from the CELL_ FACH state to the CELL_PCH state.

CELL_ DCH inactivity timerParameter definition: When the FD UE in the CELL_ DCH state has no data

transmission for the configured period, the UE is transited from the CELL_ DCH state to the CELL_PCH state. Note: You can choose the D2F or D2P transition after the timer expires. The D2F transition is recommended.

F2D 4A event thresholdParameter definition: When the 4A event service traffic of the FD UE exceeds the

configured threshold, the UE is transited from FACH/E_FACH to DCH/HSPA.The default value is D1K. If the value is too large, congestion may occur on the



common channel.

5.2 Implementation

1) Second SCCPCH expand in Old Trafford cells

The example of add script and rollback script show in the follow attachment.

Second SCCPCH.txt

2) The transmission factor of IUPS & IUB

The suggest value of transmission is 10%. The example of script shows below.

Modify:

ADD TRMFACTOR: FTI=1, REMARK="IUPS_FACTOR10", PSINTERDL=10, PSINTERUL=10,

PSBKGDL=10, PSBKGUL=10, HDINTERDL=10, HDBKGDL=10, HUINTERUL=10, HUBKGUL=10;

ADD ADJMAP: ANI=8, ITFT=IUPS, FTI=1;

Rollback

RMV ADJMAP: ANI=8, ITFT=IUPS;

3) Enable CELL_PCH

//Prolong PS inactive timer to1800s

SET UPSINACTTIMER: PSINACTTMRFORINT=1800,PSINACTTMRFORBAC=1800;

//Set State transmission timer to 5s

SET UUESTATETRANSTIMER:BEF2PSTATETRANSTIMER=5, BED2FSTATETRANSTIMER=5,

BEH2FSTATETRANSTIMER=5;

//Rollback script

SET UPSINACTTIMER: PSINACTTMRFORINT=20,PSINACTTMRFORBAC=20;

SET UUESTATETRANSTIMER:BEF2PSTATETRANSTIMER=65535, BED2FSTATETRANSTIMER=2,

BEH2FSTATETRANSTIMER=2;

4) Enable FD

//EFD enable

SET LICENSE: SETOBJECT=UMTS, ISPRIMARYPLMN=YES, FastDormancyEnhancement=******;

//Enable T323 timer



SET UCONNMODETIMER: T323=D120;

//Enable the FD function

SET URRCTRLSWITCH: PROCESSSWITCH=FAST_DORMANCY_SWITCH-1;

// Enable the FACH to DCH state transition during CS establishment and enable the D2F2P transition.

SET URRCTRLSWITCH: RsvdPara1=RSVDBIT1_BIT21-0&RSVDBIT1_BIT29-0;

//Adjust the Fast Dormancy timer

SET UPSINACTTIMER: PSINACTTMRFORPREFSTDRM=1800, PSINACTTMRFORFSTDRMDCH=55,

PSINACTTMRFORFSTDRMFACH=5;

//Set the 4A event threshold for F2D transitions to D1024

SET UUESTATETRANS: FASTDORMANCYF2DHTVMTHD=D1024;

. //FD Rollback


SET UCONNMODETIMER: T323=INVALID;


SET URRCTRLSWITCH: RsvdPara1=RSVDBIT1_BIT21-0&RSVDBIT1_BIT29-1;

SET UPSINACTTIMER: PSINACTTMRFORPREFSTDRM=360, PSINACTTMRFORFSTDRMDCH=4,

PSINACTTMRFORFSTDRMFACH=10;

SET UUESTATETRANS: FASTDORMANCYF2DHTVMTHD=D3k;

5) Correlative parameter adjust

// To avoid CS call drop rate increaseSET UCORRMALGOSWITCH: ReservedSwitch0=RESERVED_SWITCH_0_BIT28-1;//Rollback scriptSET UCORRMALGOSWITCH: ReservedSwitch0=RESERVED_SWITCH_0_BIT28-0;

5.3 Effect evaluate

Signaling Storm solution will have better effect in a network which has high smart phone

penetration.

The value of inactive timer affects the effect of CELL_PCH and EFD. Take inactive timer

value 1800s as example, filter out the data which PS RAB timer >2 in one hour (For the value of



inactive timer is 1800s, there will be only two PS RAB in one hour for the timer expires.)

Following data is RNC408.

Smartphone behavior definition: more than 10 PS RAB attempts for one user in one busy

hour.

The Smartphone behavior penetration of RNC408 is 36%.

Smartphone behavior users take more PS signaling load comparing with other devices. The

PS RAB Times produced by Smartphone behavior users is around 88% though the penetration of

them is only 36%.

It will reduce SPU load due to PS call attempts took 47% of SPU load, the expected benefit

for SPU load is 5~10% reduction according to Huawei engineering experience.

The average SPU mean load under the expansion threshold 50% now, it will be lower after

Smartphone solution.

The subscribers in the CELL_FACH/CELL_PCH will save more power resourcecode

resourceCNBAPCE resource to maximize the network capacity during the event .



5.4 KPI Monitoring

The changes on the number of PS RAB connections, SPU and CE service call drop rate, and combined service proportion must be monitored with emphasis.

Name KPI/Counter Remarks Expectation

RRC Access VS.RRC.AttConnEstab.Sum None ReducedPS RAB VS.RAB.AttEstabPS.RNC Importa

ntReduced

VS.RAB.AbnormRel.PS Important

Increased

CS RAB VS.RAB.AbnormRel.AMR.RNC None Increased slightly

CellUpdt VS.AttCellUpdt None IncreasedCommon Channel VS.FACH.DCCH.CONG.TIME Importa

ntNot deteriorated

VS.FACH.DTCH.CONG.TIME Not deteriorated

CPU VS.XPU.CPULOAD.MEAN Important

Reduced

VS.INT.CPULOAD.MEAN Important

Reduced

State Transit VS.DCCC.Succ.F2D None IncreasedVS.DCCC.Succ.D2F None IncreasedVS.DCCC.Att.F2P None IncreasedVS.DCCC.Succ.F2P None IncreasedVS.DCCC.P2F.Att None IncreasedVS.DCCC.P2F.Succ None Increased

Radio Link(CNBAP)

VS.IUB.SuccRLAdd Important

Reduced

VS.IUB.SuccRLRecfg Important

Reduced

VS.IUB.SuccRLSetup Important

Reduced

Credit VS.LC.ULCreditUsed.Mean Important

Reduced

VS.LC.DLCreditUsed.Mean Important

Reduced

Multirab VS.MultiRAB.CSAbnormRel.CSPS

Important

Does not increase



Name KPI/Counter Remarks Expectation

remarkablyVS.MultiRAB.CSNormRel.CSPS None IncreasedVS.MultiRAB.AttEstab.CSPS None IncreasedVS.MultiRAB.CSAbnormRel.PSAtt None Not increased

remarkably

5.5 KPI impacts Risk Analysis and Countermeasures

After the CELL_PCH and EFD are implemented, the PS call drop rate is affected; the user experience is not affected. You can use the counter in the KPI formula of the PS call drop rate to avoid the impact.

Modi fyi ng the KPI Formul a. docx

Some other KPIs may also affect, the actual affect is due to the network environment.


huawei signaling storm solution trial proposal

Documents

trial plan

huawei date

solution implementation

trial environment requirements

huawei confidential

huawei technologies

parameter configuration

network elements requirements