Fast dormancy Introduction Dec-2013

HUAWEI TECHNOLOGIES Co., Ltd.

www.huawei.com

HUAWEI Confidential

Enhanced Fast Dormancy

HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 2

1

Contents

Signaling storm surging

2 EFD Feature benefits

3 Signaling processing procedures


0

100

200

300

400

500

600

700

2008 2009 2010 2011 2012 2013 2014 2015

Smart phone come with tremendous signaling increasing

Smart Phone Sales Increasing Rapidly

8% Smartphone take 55% call attempt

Source：Airvana

Call attempt

Distribution:

Device

Distribution:

Smartphone,

55%

Other

Devices,

45%

Other Devices,

92%

Smartphone, 8%

14x volume than traditional handset

Source: Informa Telecoms & Media, July 2010

Smartphone Sales (M)


Pre fast dormancy & app heartbeat are the source

Frequent “Heartbeat”

Com

mo

n U

E

Signalling

Data

Sm

art

ph

one

Heartbeat Data Service Data Service

Idle Status

47163

68149

92070

117389

0

20000

40000

60000

80000

100000

120000

140000smartphone shipments increasing

2006 2009 2008 2007

SIGNALLING CONN. RELEASE INDICATION

Cell_DCH

IDLE

UE releases Iu

signalling conn.

RNC releases RRC conn.

Pre Fast Dormancy

Keep UE always on line

but increase

signaling traffic

Prolong UE battery

but increase

signaling traffic

UE RNC Node

B

SGS

N

Idle<->DCH<->Idle Signalling Flow

( 31 Signaling Message)


1

Contents




HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential

EFD Feature Benefits

EFD is the solution to signaling storm:

The RNC transits a UE to the CELL_PCH state instead of idle mode upon receiving an SCRI message from the UE or

UE inactivity timer expires.

In this case, when the UE periodically sends heartbeat messages, the signaling procedure between UE and RNC is

simplified because the RRC connection is maintained.

As the number of signaling exchange messages decreases, significant CPU resources can be saved for the RNC, and

the UE consumes about the same low amount of battery power as a UE in idle mode.

RNC-initiated state transition of UEs has no impact on user experience. UEs can save power when entering the

CELL_PCH state.

UE consumes about the same low amount of battery power as a UE in idle mode.

RNC SGSN GGSNNodeBSmart

PhoneIDLE

Cell_DCH

RNC SGSN GGSN

NodeB

Smart Phone

Cell_DCH

Cell_PCH

Legacy Architecture EFD Architecture

For the pre fast dormancy UEs, the RNC checks for compatibility issues after receiving an SCRI message. If there are

no compatibility issues, the RNC puts the UE into the CELL_PCH state.

For the R8 fast dormancy UEs, the RNC puts the UE into the CELL_PCH state after receiving an SCRI message.


DCH

IDLE

Normal Procedure

Idle<->DCH<->Idle


PS Signaling Message

60

%

60

% 60

%

10

% 0%

20%

40%

60%

80%

100%

Normal Smart Data Service

W/o smart procedure

<20%

100%

50%

W/t smart procedure

Signalling


Data

Idle

Data service Heartbeat

FACH

PCH

FACH

DCH PCH

PCH<->FACH<->DCH <->PCH


PCH<->FACH<->PCH


Smart Procedure

Data service Heartbeat


PCH

Heartbeat

Smart Procedure: Reduce Signaling Traffic


>200 mA

>100 mA

<5 mA

IDLE

CELL

_DCH

CELL/URA_PCH

CELL_FACH

CELL_DCH

CELL/URA_PCH

CELL_FACH

CELL

_FACH

CELL_DCH

CELL/URA

_PCH

IDLE <5 mA

Release Connecting Release

>1Kbps

<1Kbps

Release <1Kbps

Same procedure for all packet For large packet For small packet

(such as heartbeat)

“Fast Dormancy” procedure “Fast Dormancy Enhancement” procedure

Power consumption for each status

Assume

as

100% 35

<100%

18 <50%

6

Without

“Fast Dormancy”

“Fast Dormancy

Enhancement”

– large packet

Handset Power

Consumption

Signaling volume

With

“Fast Dormancy”

“Fast Dormancy

Enhancement”

– Small packet

49%

83%

“Fast Dormancy Enhancement ” reduce 49~83% signaling and save more power

How to optimize both Power consumption and Signaling

Volume


1

Contents





Signaling processing procedures for pre fast dormancy UEs and R8 fast dormancy UEs before

and after EFD is enabled

Signaling Procedure for pre Fast dormancy and R8

smartphones


RNC will:

•Release the RRC connection,

•Then each of the following heartbeat messages will cause

• RRC connection setup,

• authentication,

• encryption

• and RAB setup procedures.

Comparing to normal PS call procedure, this Fast dormancy mechanism will greatly increase the signaling processing cost

of RNC and may cause overflow of signaling processing unit in RNC.

Without EFD

•RNC will decided to transfer the state of the UE to CELL_PCH instead of IDLE mode.

•When UE periodically sends heartbeat message, RNC will reconfigure UE to CELL_FACH or CELL_DCH.

• The signaling procedure between UE and RNC will be limited to only a few message exchanges because the RRC

connection keep existing, at least 40% signaling exchange can be reduced and RNC CPU resources can be saved

significantly while UE battery consumption is saved as much as that in IDLE mode.

With EFD

Signaling Procedure for pre Fast dormancy and R8

smartphones


How to identify Fast Dormancy Mobiles

The T323 is sent to the UE by the SIB1 message.

The R8 fast dormancy UEs send an SCRI message with the IE Signaling Connection Release Indication Cause set to "UE

Requested PS Data session end" after PS data transmission is complete.

The RNC identifies the R8 fast dormancy UEs by reading the value of IE Signaling Connection Release Indication Cause.

This mechanism is standardized by 3GPP Release 8.

R8 Fast Dormancy

TAC(8 bits) SNR(6bits) Spare(1bit)

RNC can recognize the smart phone by IMEI TAC list when UE establish a PS service

This mechanism, which is not standardized, is used for the early proprietary implementations of fast dormancy.

IMEI, which consists of 14 decimal digits and one check digit, contains TAC and SNR. TAC indicates a particular type of

device

Pre Fast Dormancy

The RNC identifies the pre fast dormancy UEs and R8 fast dormancy UEs using the following

mechanisms:

If T323 is set to Invalid, EFD Feature is disabled for R8 Mobiles; the UE will be considered as pre Fast dormancy not

recognized by RNC; it will send SCRI without cause and go to Idle Mode

Note


Enhanced fast dormancy issues precaution

PS service drop rate raise

1. New add Common Channel(FACH/PCH) call drop of PS R99, no influence for

HSDPA and HSUPA.

2. RAB normal release times reduce lead to the calculation result raise, but no

influence for end-user experience.

PS Service Drop Rate(RNC) =

CS call drop rate raise

1. Combined CS+PS service lead to increase UL EDCH number, then the coverage

will be a little weaker than only for CS service.

2. PS TRB reset will lead to CS call drop when combined CS+PS service happen

Page 13

RAB abnormal release times

RAB abnormal release times + RAB normal release times * 100%


Background

HSPA

R99 DCH CELL FACH

CELL PCH

Idle

RRC Connected State RRC Idle State

In traditional way, CELL PCH is believed as connected state, and only UE released from

connected state to idle, and then it is statistic as a normal release.

Normal release

Normal release

Normal release

Normal release


Service Model in Practice

HSPA

R99 DCH CELL FACH

CELL PCH

Idle

If Cell PCH state is used, UE will transit to Cell PCH state after one PS session end.

In extreme condition, UE will have no chance to be released to idle state.

It will cause wrong release times in statistic.

PS session stars PS session ends

RRC Connected State RRC Idle State


Solution （PS Call）

HSPA CELL DCH

R99 CELL DCH CELL FACH CELL PCH

Idle

UE can not send any data in Cell PCH state. So we can put idle and Cell PCH as “Session

Idle State” state in logical. Our statistic should reflect the real user experience, so PS

session should be used, but not RRC state.

Session Connected State Session Idle State


Proposed New formula PS CDR(PCH)

PS Call Drop Ratio with PCH (Cell)= [(VS.RAB.AbnormRel.PS-VS.RAB.AbnormRel.PS.PCH-VS.RAB.AbnormRel.PS.D2P-

VS.RAB.AbnormRel.PS.F2P) / (VS.RAB.AbnormRel.PS+ VS.RAB.NormRel.PS-VS.RAB.AbnormRel.PS.PCH-VS.RAB.NormRel.PS.PCH+

VS.DCCC.D2P.Succ+VS.DCCC.Succ.F2P)]*100%

PS Service Drop Ratio with PCH (RNC)= [(VS.RAB.AbnormRel.PS.RNC- Sum{VS.RAB.AbnormRel.PS.PCH}-

Sum{VS.RAB.AbnormRel.PS.D2P}- Sum{VS.RAB.AbnormRel.PS.F2P})/(VS.RAB.AbnormRel.PS.RNC+ VS.RAB.NormRel.PS.RNC-

Sum{VS.RAB.AbnormRel.PS.PCH}-Sum{VS.RAB.NormRel.PS.PCH}+ Sum{VS.DCCC.D2P.Succ}+Sum{VS.DCCC.Succ.F2P})]*100%

PS R99 CDR(PCH)

PS R99 Call Drop Ratio with PCH (Cell)= [(VS.RAB.AbnormRel.PSR99- VS.RAB.AbnormRel.PS.PCH-VS.RAB.AbnormRel.PS.R99D2P-

VS.RAB.AbnormRel.PS.F2P)/ (VS.RAB.AbnormRel.PSR99+ VS.RAB.NormRel.PSR99- VS.RAB.AbnormRel.PS.PCH-

VS.RAB.NormRel.PS.PCH+ VS.HSDPA.F2H.Succ+VS.HSDPA.D2H.Succ+VS.PSR99.D2P.Succ+VS.DCCC.Succ.F2P)]*100%

HSDPA CDR(PCH)

HSDPA Service Drop Ratio with PCH(Cell)=[(VS.HSDPA.RAB.AbnormRel-

VS.HSDPA.RAB.AbnormRel.H2P)/(VS.HSDPA.RAB.AbnormRel+VS.HSDPA.RAB.NormRel+ VS.HSDPA.HHO.H2D.SuccOutIntraFreq+

VS.HSDPA.HHO.H2D.SuccOutInterFreq+ VS.HSDPA.H2D.Succ+ VS.HSDPA.H2F.Succ+ VS.HSDPA.H2P.Succ)]*100%

HSDPA Service Drop Ratio with PCH(RNC)= [(VS.HSDPA.RAB.AbnormRel+ VS.RAB.AbnormRel.HSDPA.Iur- VS.HSDPA.RAB.AbnormRel.H2P)/

(VS.HSDPA.RAB.AbnormRel+ VS.RAB.AbnormRel.HSDPA.Iur+ VS.RAB.NormRel.HSDPA.Iur+

VS.HSDPA.RAB.NormRel+ VS.HSDPA.H2D.Succ+ VS.HSDPA.H2F.Succ+VS.HSDPA.HHO.H2D.SuccOutIntraFreq+

VS.HSDPA.HHO.H2D.SuccOutInterFreq+ VS.HSDPA.H2P.Succ)]*100%

HSUPA CDR(PCH)

HSUPA Call Drop Ratio with PCH (Cell)= [(VS.HSUPA.RAB.AbnormRel- VS.HSUPA.RAB.AbnormRel.E2P)/ (VS.HSUPA.RAB.AbnormRel+

VS.HSUPA.RAB.NormRel+ VS.HSUPA.HHO.E2D.SuccOutIntraFreq+ VS.HSUPA.HHO.E2D.SuccOutInterFreq+ VS.HSUPA.E2F.Succ+ VS.HSUPA.E2D.Succ+

VS.HSUPA.E2P.Succ)]*100%

HSUPA Call Drop Ratio with PCH (RNC)= [(VS.HSUPA.RAB.AbnormRel+ VS.RAB.AbnormRel.HSUPA.Iur-VS.HSUPA.RAB.AbnormRel.E2P)/

(VS.HSUPA.RAB.AbnormRel+ VS.HSUPA.RAB.NormRel+ VS.RAB.AbnormRel.HSUPA.Iur+

VS.RAB.NormRel.HSUPA.Iur+ VS.HSUPA.HHO.E2D.SuccOutIntraFreq+ VS.HSUPA.HHO.E2D.SuccOutInterFreq+ VS.HSUPA.E2F.Succ+ VS.HSUPA.E2D.Succ+

VS.HSUPA.E2P.Succ)]*100%

Thank you www.huawei.com

Copyright©2008 Huawei Technologies Co., Ltd. All Rights Reserved. The information contained in this document is for reference purpose only, and is subject to

change or withdrawal according to specific customer requirements and conditions.

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Fast dormancy Introduction Dec-2013