Enhanced Fast Dormancy

WCDMA RAN

Enhanced Fast Dormancy Feature Parameter Description

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.

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and other Huawei trademarks are the property 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 commercial contract made between Huawei and the customer. All or partial products, services and features described in this document may not be within the purchased scope or the usage scope. Unless otherwise agreed by 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.

Contents

1 Introduction

1.1 Scope

1.2 Intended Audience

1.3 Change History

2 Overview

3 Fast Dormancy

4 Enhanced Fast Dormancy

4.1 Overview

4.2 Identifying Fast Dormancy UEs

4.3 State Transition of Fast Dormancy UEs

5 Parameters

6 Counters

7 Glossary

8 Reference Documents

http://localhost:7890/pages/GEA0331D/08/GEA0331D/08/resources/FPD/Enhanced%20Fast%20Dormancy.htm?ft=99&fe=1&id=GEA0331D_08_10022&keyword=fast+dormancy&noteId=#_Toc288920821














1 Introduction

1.1 Scope

This document describes the feature of fast dormancy (WRFD-020500 Enhanced Fast Dormancy).

1.2 Intended Audience

This document is intended for:

Personnel who need to understand fast dormancy.

Personnel who work with Huawei products

1.3 Change History

This section provides information on the changes in different document versions.

There are two types of changes, which are defined as follows:

Feature change: refers to the change in the fast dormancy feature of a specific product version.

Editorial change: refers to the change in wording or the addition of the information that was not described in the earlier version.

Document Issues

The document issues are as follows:

03 (2012-06-30)

02 (2011-03-30)

01 (2010-06-20)

03 (2012-06-30)

This is the document for the third commercial release of RAN12.0.

Compared with issue 02 (2011-03-30) of RAN12.0, this issue incorporates the changes described in the following table.

Change Type Change Description Parameter Change

Feature change None. None.

Editorial change The document is renamed “Enhanced Fast DormancyFeature Parameter Description” from ”FastDormancy Feature Parameter Description”.

None.

02 (2011-03-30)

This is the document for the second commercial release of RAN12.0.

This issue optimizes the description.

01 (2010-06-20)

This is the document for the first commercial release of RAN12.0.

Fast dormancy is introduced in RAN12.0.

2 Overview

When fast dormancy or enhanced fast dormancy is applied, the UE can request the RNC to release the PS signaling connection if no more PS data is transmitted. After receiving the request, the RNC can either release the signaling connection and put the UE into idle mode, or maintain the signaling connection and put the UE into an efficient battery consumption RRC state such as IDLE, CELL_PCH.

3 Fast Dormancy

UEs complying with 3GPP Release 8 support the fast dormancy function, as defined in 3GPP TS 25.331 CR3483. After a UE processing only PS services finishes the PS data transmission, it sends the RNC a Signaling Connection Release Indication (SCRI) message, which contains the cause value of "UE Requested PS Data session end". Upon receiving the message, the RNC releases the RRC connection of the UE and enables the UE to quickly enter the power saving mode.

The following figure shows the procedure of fast dormancy.

Figure 3-1 Fast dormancy

The RNC sends timer T323 in SIB1 or UTRAN Mobility Information to the UE to control fast dormancy.

If the value of T323 is INVALID, the timer is not sent to the UE, and accordingly the UE does not send the SCRI message containing the information element (IE) "UE Requested PS Data session end".

If the value of T323 is 0, the UE sends the release request only once.

If the value of T323 is a value other than 0, the UE sends the release request and initiates timer T323. The UE sends the release request again after T323 expires.

4 Enhanced Fast Dormancy

4.1 Overview

As the number of intelligent UEs keeps increasing in mobile networks, the networks face signaling storms produced by these UEs. With many customers all over the world, Huawei has rich experience in network optimization. Huawei can provide a comprehensive end-to-end solution to respond to network challenges based on network characteristics. This feature is a component of the comprehensive solution. Deploying this feature only cannot solve the signaling storm problem caused by intelligent UEs. It is recommended that this feature together with professional services be deployed to optimize the quality of service of the entire network.

Note:

Consult Huawei engineers about the comprehensive solution to obtain professional technical support. Huawei engineers will recommend the appropriate parameter settings for this feature based on the network conditions.

Do not configure the parameters related to this feature without Huawei professional technical support. Inappropriate parameter settings may lead to network failures.

Enhanced fast dormancy applies to a network that serves a large number of intelligent UEs supporting fast dormancy. This function can reduce the signaling processing efforts of the RNC and avoid overflow of the signaling processing unit in the RNC that fast dormancy may cause.

To save power, when there is no PS data transmission, an intelligent UE sends the RNC an SCRI message to request the RRC connection release or to indicate to the UTRAN that one of its signaling connections has been released. In addition, the UE periodically sends the heartbeat messages (to check new mails in the mail server for example) to the core network.

If fast dormancy (instead of enhanced fast dormancy) is applied, the RNC releases the RRC connection as specified by the 3GPP specifications. In such a case, the heartbeat messages will lead to performing the procedures of RRC connection setup, authentication, encryption, and RAB setup. This greatly increases the signaling processing efforts of the RNC and may cause overflow of the signaling processing unit in the RNC.

Enhanced fast dormancy is introduced to solve the preceding problem. With the application of enhanced fast dormancy, the RNC changes the UE state to CELL_PCH instead of idle mode after receiving the SCRI message from the UE. In such a case, when the UE periodically sends the heartbeat messages, the signaling procedure between the UE and RNC is simplified because the RRC connection is maintained. As the number of signaling exchange messages decreases, the CPU resources of the RNC can be saved significantly, and the UE consumes as less battery energy as a UE in idle mode.

The following figure shows the comparison between fast dormancy and enhanced fast dormancy.

Figure 4-1 Comparison between fast dormancy and enhanced fast dormancy

4.2 Identifying Fast Dormancy UEs

Two types of the fast dormancy mechanism are implemented in UEs. These UEs are referred to as fast dormancy UEs in this document.

R8 fast dormancy: This mechanism is standardized by 3GPP Release 8. As specified, the UE sends a SIGNALLING CONNECTION RELEASE INDICATION (SCRI) message to the network with the IE “Signaling Connection Release Indication Cause” set to "UE Requested PS Data session end."

The RNC can identify this type of UE by the SCRI message with IE "UE Requested PS Data session end."

Pre-R8 fast dormancy: This mechanism, which is not standardized, is used for the early proprietary implementations of fast dormancy prior to Release 8.

The RNC can identify this type of UE by its IMEI and its release version.

After the RNC receives the Security Mode Command Complete message from the UE, the RNC identifies fast dormancy UEs as follows:

If the FD_TAC_MATCH_SWITCH of the parameter PROCESSSWITCH is turned on, the following UEs are identified as fast dormancy UE.

− UE (Pre-R8 fast dormancy) that complies with 3GPP Release 5 or later releases and whose IMEI falls into the white list. The IMEI range for white list is specified by the binary group (TAC, FastDormancy = ON) in the RNC MML command ADD UIMEITAC. If the FastDormancy switch is on, the RNC considers the UEs specified by the IMEI (TAC) as capable of enhanced fast dormancy.

− UE (R8 fast dormancy) from which the SCRI message whose cause value is "UE Requested PS Data session end." is sent.

If the FD_TAC_MATCH_SWITCH of the parameter PROCESSSWITCH is turned off, the following UEs are identified as fast dormancy UE.

− UEs complying with 3GPP Release 5 or later releases are identified as fast dormancy UE excluding the UEs in the black list..The IMEI range for the black list is specified by the binary group (TAC, FastDormancy = OFF) in the RNC MML command ADD UIMEITAC. If the FastDormancy switch is OFF, the RNC considers the UEs specified by the IMEI (TAC) as incapable of enhanced fast dormancy.

The RNC can obtain the IMEI of the UE from the UE's response to the "IDENTITY REQUEST" message. The range of the IMEI is specified by the parameter TAC in the RNC MML command ADD UIMEITAC.

The IMEI (consisting of 14 decimal digits and one check digit) contains information on the origin, model, and serial number of the UE. The structure of the IMEI is specified in 3GPP TS 23.003.

TAC (8bit) FAC (2bit) SNR (6bit) Spare (1bit)

The Type Allocation Code (TAC) indicates the particular type of device that has been approved by a national GSM/WCDMA approval body. In the 3GPP specifications released later than 2003, the TAC length is changed from 6 bit to 8 bit.

The Final Assembly Code (FAC), which is manufacturer-specific, indicates the location where the UE is manufactured.

SNR is the serial number identifying the UE.

The RNC can determine whether a UE supports fast dormancy according to the information on the manufacturer and model contained in the TAC.

4.3 State Transition of Fast Dormancy UEs

If enhanced fast dormancy is disabled, the RRC connection of the UE is released after the RNC received the SCRI. The switches of enhanced fast dormancy are specified by the RNC level subparameter FAST_DORMANCY_SWITCH of the parameter PROCESSSWITCH.

If enhanced fast dormancy is enabled, then

If the UE is identified as R8 UE (the UE can report the SCRI with R8 extensional cause of “data session end”),

− If the RNC received the SCRI with the cause of “data session end”, the RNC transfers the UE to CELL_FACH or CELL_PCH.

If the UE in not R8 UE and the UE is identified as fast dormancy UE,

− If the inactive timer for enhanced fast dormancy times out, the RNC transfers the UE to CELL_FACH or CELL_PCH.

The following figure shows the detailed state transition of a fast dormancy UE.

Figure 4-2 State transition of a fast dormancy UE

Table 4-1 State Transition of Fast Dormancy UEs

Type Description

D2P D2F

F2P

D2P is from CELL_DCH to CELL_PCH. F2P is from CELL_FACH to CELL_PCH. D2F is from CELL_DCH to CELL_FACH.

The RNC starts the PS inactivity timer for fast dormancy after the fast dormancy UE changes the state.

PsInactTmrForFstDrmDch specifies the PS inactivity timer for CELL_DCH

PsInactTmrForFstDrmFach specifies the PS inactivity timer for CELL_FACH

PsInactTmrForPreFstDrm specifies the PS inactivity timer for CELL_PCH

If the UE is a fast dormancy UE and is not processing CS services, when the PS inactivation timer for fast dormancy expires or the RNC receives the SCRI message or 4B event from the UE, the state transition of the UE is performed as follows:

If the UE is in the CELL_DCH state,

− If RSVDBIT1_BIT29 in SET URRCTRLSWITCH is set to 0, RNC will trigger the D2F state transition.

− If RSVDBIT1_BIT29 in SET URRCTRLSWITCH is set to 1, RNC will trigger the D2P state transition.

If the UE is in the CELL_FACH state,

− The RNC will trigger F2P state transition.

D2I D2I is from CELL_DCH to IDLE.

When the FACH is congested, D2F won’t be triggered for inactive CELL_DCH users. Instead, RNC will trigger D2I to release this UE.

The default D2I function switch is off. You can switch on the function through the following command:

SET UCORRMALGOSWITCH: ReservedSwitch0=RESERVED_SWITCH_0_BIT16-1;

P2I P2I is from CELL_PCH to IDLE.

If the UE is in the CELL_PCH state, when the PS inactivation timer for fast dormancyPsInactTmrForPreFstDrm expires, the RNC releases the RRC connection and then the UE enters the IDLE state.

P2D P2D is from CELL_PCH to CELL_DCH.

If the switch RsvdPara1 > RSVDBIT1_BIT20 (SET URRCTRLSWITCH) is turned on:

When the UE tries to set up an originated or a terminated CS service and the FACH is congested, the RNC instructs the UE to perform P2D state transition instead of P2F2D.

SET URRCTRLSWITCH: RsvdPara1=RSVDBIT1_BIT20-0;

Note: for the switch, the value 0 means on and 1 means off.

If the switch PROCESSSWITCH > FD_P2D_SWITCH (ADD UIMEITAC) is turned on:

If the TAC of the UE is the same as that configured on the RNC and if the UE is in the CELL_PCH and the UE is going to transmit uplink data or respond to paging message, the RNC instructs the UE to perform P2D directly.

P2F P2F is from CELL_PCH to CELL_FACH.

When the UE transmits the heartbeat messages or traffic data, the RNC instructs the UE to enter the CELL_FACH state.

F2D F2D is From CELL_FACH to CELL_DCH.

When the fast dormancy UE is in the CELL_FACH state, the state transition of the UE is performed as follows:

If the UE reports event 4A to the RNC, the RNC instructs the UE to enter the CELL_DCH state.

If the UE reports event 4B to the RNC, the RNC instructs the UE to enter the CELL_PCH state.

When the fast dormancy UE periodically sends small heartbeat messages, the normal state transition mechanism will change the UE status from the CELL_FACH state to CELL_DCH state. To prevent the state transition triggered by small heartbeat messages, a new threshold for Event 4A (FastDormancyF2DHTvmThd) is introduced.

To avoid too many UEs remaining in the CELL_FACH state, fast dormancy ensures that the state transition switch does not affect the 4A and 4B measurement and state transition from CELL_FACH to other state for fast dormancy UEs in CELL_FACH.

5 Parameters

Table 5-1 Parameter description

Parameter ID NE MML Command Description

FastDormancy BSC6900 ADD UIMEITAC(Optional) MOD UIMEITAC(Optional)

Meaning: The switch of FastDormancy function for one type UE. GUI Value Range: OFF, ON Actual Value Range: ON, OFF Unit: None Default Value: OFF

FastDormancyF2DHTvmThd BSC6900 SET UUESTATETRANS(Optional)

Meaning: This parameter specifies the threshold of the traffic volume of 4A event for triggering the transition of fastdormancy user from FACH/E_FACH to DCH/HSPA. GUI Value Range: D16, D32, D64, D128, D256, D512, D1024, D2k, D3k, D4k, D6k, D8k, D12k, D16k, D24k, D32k, D48k, D64k, D96k, D128k, D192k, D256k, D384k, D512k, D768k Actual Value Range: 16, 32, 64, 128, 256, 512, 1024, 2k, 3k, 4k, 6k, 8k, 12k, 16k, 24k, 32k, 48k, 64k, 96k, 128k, 192k, 256k, 384k, 512k, 768k Unit: byte Default Value: D3k


PROCESSSWITCH BSC6900 ADD UIMEITAC(Optional) MOD UIMEITAC(Optional)

Meaning: 1)FD_P2D_SWITCH When this switch is on, the UE transits from CELL_PCH or URA_PCH state to CELL_DCH state when both the following conditions are met: 1. The TAC of the UE is the same as that configured on the RNC side. 2. The UE is in CELL_PCH or URA_PCH state, and the RNC receives a CELL UPDATE message with the cause value of "uplink data transmission" or "paging response" of PS domain. When this switch is off, the UE does not transit from CELL_PCH or URA_PCH state to CELL_DCH state even if the RNC receives a CELL UPDATE message containing a cause value of "uplink data transmission" or "paging response" of PS domain. The state transition of the UE from CELL_PCH or URA_PCH to CELL_DCH, however, can be triggered in other conditions. For example, the state transition from CELL_PCH or URA_PCH to CELL_DCH is triggered by a UE-terminated CS call. GUI Value Range: FD_P2D_SWITCH, RSVDBIT1_BIT2, RSVDBIT1_BIT3, RSVDBIT1_BIT4, RSVDBIT1_BIT5, RSVDBIT1_BIT6, RSVDBIT1_BIT7, RSVDBIT1_BIT8, RSVDBIT1_BIT9, RSVDBIT1_BIT10, RSVDBIT1_BIT11, RSVDBIT1_BIT12, RSVDBIT1_BIT13, RSVDBIT1_BIT14, RSVDBIT1_BIT15, RSVDBIT1_BIT16, RSVDBIT1_BIT17, RSVDBIT1_BIT18,


RSVDBIT1_BIT19, RSVDBIT1_BIT20, RSVDBIT1_BIT21, RSVDBIT1_BIT22, RSVDBIT1_BIT23, RSVDBIT1_BIT24, RSVDBIT1_BIT25, RSVDBIT1_BIT26, RSVDBIT1_BIT27, RSVDBIT1_BIT28, RSVDBIT1_BIT29, RSVDBIT1_BIT30, RSVDBIT1_BIT31, RSVDBIT1_BIT32 Actual Value Range: This parameter is set to 0 or 1 according to the related domains. Unit: None Default Value: None

PsInactTmrForFstDrmDch BSC6900 SET UPSINACTTIMER(Optional)

Meaning: This parameter specifies the value of the CELL-DCH inactivity timer for UEs enabled with the Fast Domancy feature. When detecting that theFast Domancy User in PS domain had no data to transfer in CELL-DCH for a long time which longer than this timer, the state transition from CELL-DCH to CELL-FACH or CELL-PCH is triggered. To enable this timer, set this timer to a value other than 0. GUI Value Range: 0~64800 Actual Value Range: 0~64800 Unit: s Default Value: 4


PsInactTmrForFstDrmFach BSC6900 SET UPSINACTTIMER(Optional)

Meaning: This parameter specifies the value of the CELL-FACH inactivity timer for UEs enabled with the Fast Dormancyfeature. When detecting that theFast Dormancy User in PS domain had no data to transfer in CELL-FACH for a long time which longer than this timer, the state transition from CELL-FACH to CELL-PCH is triggered. To enable this timer, set this timer to a value other than 0. GUI Value Range: 0~64800 Actual Value Range: 0~64800 Unit: s Default Value: 10

PsInactTmrForPreFstDrm BSC6900 SET UPSINACTTIMER(Optional)

Meaning: This parameter specifies the value of the CELL-PCH inactivity timer for UEs enabled with the Fast Dormancyfeature. When detecting that theFast Dormancy User in PS domain had no data to transfer in CELL-PCH for a long time which longer than this timer, the UE is released. To enable this timer, set this timer to a value other than 0. GUI Value Range: 0~64800 Actual Value Range: 0~64800 Unit: s Default Value: 360

TAC BSC6900 ADD UIMEITAC(Mandatory) MOD UIMEITAC(Mandatory) RMV UIMEITAC(Mandatory)

Meaning: Type Allocation Code (TAC) is part of the International Mobile Station Equipment Identity (IMEI), it is used to identify the type of the UE. GUI Value Range: 0~99999999 Actual Value Range: 0~99999999 Unit: None Default Value: None


RsvdPara1 BSC6900 SET URRCTRLSWITCH(Optional)

Meaning: Reserved parameter 1. GUI Value Range: RSVDBIT1_BIT1, NAS_QOS_MOD_SWITCH, RSVDBIT1_BIT3, RSVDBIT1_BIT4, RSVDBIT1_BIT5, RSVDBIT1_BIT6, RSVDBIT1_BIT7, RSVDBIT1_BIT8, RSVDBIT1_BIT9, RSVDBIT1_BIT10, RSVDBIT1_BIT11, RSVDBIT1_BIT12, RSVDBIT1_BIT13, RSVDBIT1_BIT14, RSVDBIT1_BIT15, RSVDBIT1_BIT16, SYSHO_CSIN_PERMIT_SWITCH, RSVDBIT1_BIT18, RSVDBIT1_BIT19, RSVDBIT1_BIT20, RSVDBIT1_BIT21, RSVDBIT1_BIT22, RSVDBIT1_BIT23, RSVDBIT1_BIT24, RSVDBIT1_BIT25, RSVDBIT1_BIT26, RSVDBIT1_BIT27, RSVDBIT1_BIT28, RSVDBIT1_BIT29, RSVDBIT1_BIT30, RSVDBIT1_BIT31, RSVDBIT1_BIT32 Actual Value Range: This parameter is set to 0 or 1 according to the related domains. Unit: None Default Value: None

6 Counters

For details, see the BSC6900 UMTS Performance Counter Reference.

7 Glossary

For the acronyms, abbreviations, terms, and definitions, see the Glossary.

http://localhost:7890/pages/GEA0331D/08/GEA0331D/08/resources/FPD/Glossary.htm

8 Reference Documents

[1] State Transition Feature Parameter Description

[2] 3GPP TS 25.331

[3] 3GPP TS 23.003

http://localhost:7890/pages/GEA0331D/08/GEA0331D/08/resources/FPD/State%20Transition.htm