Owo116120 Wcdma Ran14 State Transition Issue1.00

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

WCDMA RAN14 State

Transition

Copyright © 2012 Huawei Technologies Co., Ltd. All rights reserved. Page2

Foreword

UE with different service type and traffic volume will occupy

differentiated resource. It is necessary to control UE behavior,

in purpose of optimizing system resource.

State transition is built on DCCC mechanism


Objectives

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

Outline state transition categories

Describe the realization method of state transition

Perform the parameter adjustment of state transition


Contents

1. UE State Transition Overview

2. Basic UE State Transition Description

3. UE State Transition Application


UE State Transition in UTRAN

Connected Mode

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CELL_DCH CELL_FACH

CELL_PCH URA_PCH

IDLE

UTRAN Connected Mode

Establish RRC

Release RRC

Establish RRC

Release RRC

4b+timer/overload

4a

4b+timer

Paging/Data

Paging/Data

Cell reselection (Timer+Counter)

Smart P2D


See comment

UE State Transition Types


UE State Transition Switches

Switches Description

DRA_PS_BE_STATE_TRANS_SWITCH Controls state transition for UEs performing BE

services

DRA_PS_NON_BE_STATE_TRANS_SWITCH Controls state transition for UEs performing non-

BE services

DRA_HSDPA_STATE_TRANS_SWITCH Controls state transition from HS-DSCH to FACH

DRA_HSUPA_STATE_TRANS_SWITCH Controls state transition from E-DCH to FACH

DRA_SMART_FAST_STATE_TRANS_SWITCH

Controls identification of UEs capable of fast

state transition, and fast state transition from

CELL_DCH to CELL_PCH, URA_PCH, or

CELL_FACH

DRA_PCH_UE_SMART_P2D_SWITCH Controls fast state transition from CELL_PCH or

URA_PCH to CELL_DCH

DRA_F2U_SWITCH Controls state transition from CELL_FACH to

URA_PCH directly

SET UCORRMALGOSWITCH (DraSwitch) defines the following RNC-level

switches for dynamic resource allocation


UE State Transition Switches(Cont.)


RNC_U2U_SWITCH Controls state transitions to URA_PCH after a cell

update initiated in the URA_PCH state

SET URRCTRLSWITCH (ProcessSwitch3) defines the RNC-level switch for

state transitions from the URA_PCH state to the URA_PCH state.

ADD UCELLDCCC (DraSwitch) defines the cell-level switches for fast state

transition.


DRA_SMART_FAST_STATE_TRANS_SWITCH

Controls identification of UEs capable of fast

state transition, and fast state transition from

CELL_DCH to CELL_PCH, URA_PCH, or

CELL_FACH

DRA_PCH_UE_SMART_P2D_SWITCH Controls fast state transition from the

CELL_PCH or URA_PCH to CELL_DCH state.

BE_4A_THD_ADJ_FOR_FACH_CONG_SWITCH

Controls the setting of the cell-level event 4A

threshold. For cells with FACH congestion, the

cell-level event 4A threshold can be set to a

small value to relieve FACH congestion.


Contents





Contents


2.1 D2F State Transition

2.2 F2P State Transition

2.3 F2U State Transition

2.4 P2U State Transition

2.5 P2F and U2F State Transition

2.6 U2U State Transition

2.7 F2D State Transition

2.8 D2D State Transition


CELL_DCH to CELL_FACH

UE state transition from CELL_DCH to CELL_FACH:

Transport channel

traffic volume

Time to trigger

Pending Time after trigger

Report

event 4b

Time

DCH to FACH transition time

Report

event 4bDCH to FACH transition


CELL_DCH to CELL_FACH (Cont.)

The CELL_DCH to CELL_FACH transition threshold is the

rounded-down value obtained according to the following

formula:

CELL_DCH to CELL_FACH transition threshold = [CELL_DCH to

CELL_FACH transition time/(Time to trigger + Pending time after

trigger) x State transition traffic redundancy coefficient]


CELL_DCH to CELL_FACH (Cont.)

Service Type

CELL_DCH to

CELL_FACH Transition

Timer

Threshold of

Event 4b Time to Trigger

Pending Time After

Trigger

BE service on

the DCH BeD2FStateTransTimer D2F2PTvmThd D2FTvmTimeToTrig D2FTvmPTAT

BE service on

the HS-DSCH BeH2FStateTransTimer BeH2FTvmThd BeH2FTvmTimeToTrig BeH2FTvmPTAT

Real-time

service in the

PS domain

RtDH2FStateTransTimer RtDH2FTvmThd RtDH2FTvmTimeToTrig tDH2FTvmPTAT

BE service on

the E-DCH BeE2FStateTransTimer E2FThrouThd

E2FThrouTimeToTrig

x E2FThrouMeasPeriod

E2FThrouPTAT x

E2FThrouMeasPeriod

Parameters of event 4b for CELL_DCH to CELL_FACH:


D2F Transition Parameters

Parameter Parameter name Recommended

value

BeD2FStateTransTimer BE DCH to FACH Transition

Timer 5s

D2F2PTvmThd BE D2F/R Or F/R2P 4B

Threshold 128bytes

D2FTvmTimeToTrig BE D2F/R 4B Time 5000ms

D2FTvmPTAT BE D2F/R 4B Pending Time 1000ms

BE service on the DCH:



value

BeH2FStateTransTimer BE HS-DSCH to FACH

Transition Timer 5s

BeH2FTvmThd BE HS-DSCH2F 4B Threshold 128bytes

BeH2FTvmTimeToTrig BE HS-DSCH2F 4B Time 5000ms

BeH2FTvmPTAT BE HS-DSCH2F 4B Pending

Time 1000ms

BE service on the HS-DSCH:

D2F Transition Parameters(Cont.)




value

RtDH2FStateTransTimer Realtime DCH or HSPA To

FACH Transition Timer 180s

RtDH2FTvmThd RT D/HSPA2F 4B Threshold 64bytes

RtDH2FTvmTimeToTrig RT D/HSPA2F 4B Time 5000ms

RtDH2FTvmPTAT RT D/HSPA2F 4B Pending

Time 16000ms

Real-time service in the PS domain:




value

BeE2FStateTransTimer BE E-DCH To FACH State

Transition Timer 2s

E2FThrouThd E-DCH2F 4B Threshold 8kbit/s

E2FThrouMeasPeriod E-DCH Throu Meas Period 300ms

E2FThrouTimeToTrig E-DCH2F 4B Period Amount 2

E2FThrouPTAT E-DCH2F 4B Pending Period

Amount 4

BE service on the E-DCH:



LittleRateThd

Parameter name: Low Activity Bit Rate Threshold

Recommended value: D64, namely 64kbit/s


Optimization of H2F State Transition

The CELL_DCH(HS-DSCH) to CELL_FACH transition

Transport channel

traffic volume

Time to trigger

Pending Time after trigger

Report

event 4b

Time

DCH to FACH transition time

Report

event 4bDCH to FACH transition

Report

event 4a

4a threshold

4b threshold


Parameters of Optimized H2F Switch

PERFENH_H2F_OPT_SWITCH

Parameter name: PERFENH_H2F_OPT_SWITCH

Recommended value: PERFENH_H2F_OPT_SWITCH-OFF

PerfEnhanceSwitch

Optimized H2F switch

is under parameter

PerfEnhanceSwitch


Contents











CELL_FACH to CELL_PCH

UE state transition from CELL_FACH to CELL_PCH is applicable

to BE services in the PS domain

UE state transition from CELL_FACH to CELL_PCH is similar to

UE state transition from CELL_DCH to CELL_FACH


CELL_FACH to CELL_PCH (Cont.)

The CELL_FACH to CELL_PCH transition threshold is the

rounded-down value obtained according to the following

formula:

CELL_FACH to CELL_PCH transition threshold = [CELL_FACH to

CELL_PCH transition time/(Time to trigger + Pending time after

trigger) x State transition traffic redundancy coefficient]


CELL_FACH to CELL_PCH (Cont.)

Service

Type

CELL_DCH to

CELL_FACH Transition

Timer

Threshold of

Event 4b Time to Trigger

Pending Time After

Trigger

BE service

in the PS

domain

BeF2PStateTransTimer D2F2PTvmThd F2PTvmTimeToTrig F2PTvmPTAT

Parameters of event 4b for CELL_FACH to CELL_PCH:


F2P Transition Parameters


value

BeF2PStateTransTimer BE FACH to PCH Transition

Timer None

D2F2PTvmThd BE D2F/R Or F/R2P 4B

Threshold 128bytes

F2PTvmTimeToTrig BE F2P 4B Time 5000ms

F2PTvmPTAT BE F2P 4B Pending Time 16000ms

BE service on the DCH:


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F2U State Transition

F2U state transition applies to BE services in the PS domain.

The trigger conditions, parameter settings and signaling

procedure for F2U state transitions are the same as those for

F2P state transitions.

F2U state transitions are preferentially triggered than P2U when

the conditions are met, if the switch DRA_F2U_SWITCH is

turned on, otherwise, the UE first transits to the CELL_PCH

state. After that, the UE transits to the URA_PCH state if CELL

UPDATE messages are frequently reported.


Contents











CELL_PCH to URA_PCH

Before the state transition, the state of the UE is CELL_PCH. During

the cell reselection, the UE sends the CELL UPDATE messages. The

RNC starts a timer (CellReSelectTimer) and counts the number of

CELL UPDATE messages with the cause value of cell reselection. When

the timer expires, the number of CELL UPDATE messages may be

above the threshold (CellReSelectCounter). In this case, the RNC

initiates a state transition when the UE sends the CELL UPDATE

message again


P2U Transition Parameters


value

CellReSelectTimer Cell Reselection Timer 180s

CellReSelectCounter Cell Reselection Counter

Threshold 9


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CELL_PCH/URA_PCH to CELL_FACH

The state of the UE transits from CELL_PCH/URA_PCH to

CELL_FACH when the UTRAN pages the UE or when the UE

needs to exchange information with the UTRAN


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U2U State Transition

U2U state transitions include U2F and F2U. The switch

parameter is RNC_U2U_SWITCH.

After returning to the service area, the UE that stays in the

URA_PCH state originates a cell update procedure. If the cell

update cause carried in the CELL UPDATE message is Re-

entered Service Area, the RNC sends a CELL UPDATE

CONFIRM message to instruct the UE to return to the URA_PCH

state.


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CELL_FACH to CELL_DCH

The state of the UE transits from CELL_FACH to CELL_DCH

when the UTRAN receives a report that the UL/DL traffic

volume is above the threshold of event 4a

The following table lists the target rates for UE state transitions

from CELL_FACH to CELL_DCH


F2D Transition Parameters

Service Type Parameter Parameter name

Recommended

value

BE service on the

DCH

BeF2DTvmThd BE F/R2D 4A Threshold 256bytes

BeF2DTvmTimeToTrig BE F/R2D 4A Time 0s

BE service on the

HS-DSCH

BeF2HTvmThd BE F2HS-DSCH 4A Threshold 256bytes

BeF2HTvmTimeToTrig BE F2HS-DSCH 4A Time 0s

PS real-time

service

RtF2DHTvmThd RT F2D/HSPA 4A Threshold 1024bytes

RtF2DHTvmTimeToTrig RT F2D/HSPA 4A Time 0s

BE service on the

E-DCH

BeF2ETvmThd BE F2E-DCH 4A Threshold 1024bytes

BeF2ETvmTimeToTrig BE F2E-DCH 4A Time 0s


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CELL_DCH (D2D)

For HSDPA and HSUPA, there are two more sub-state called

CELL_DCH (with HS-DSCH) and CELL_DCH (with E-DCH).

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CELL_DCH

(with E-DCH)

CELL_DCH

(with DCH)

CELL_DCH

(with HS-DSCH)

Traffic Volume(4A) Traffic Volume(4A)

Periodical Retrying

Moving to a R99 cell

Insufficient coverage

Periodical Retrying

Moving to a R99 cell


Sub-State Transition Type Type Trigger

E2D

•During RAB setup, RAB should be carried over E-DCH but resources are insufficient

•During RAB setup, RAB should be carried over E-DCH but the coverage is insufficient.

•After HSUPA RAB setup, if the radio coverage is poor during HSUPA data transmission, refer to the

descriptions under this table.

•E-DCH serving cell change (change of best cell)

− New best cell does not support E-DCH

− New best cell does not have enough resources for E-DCH

D2E

•In any of the scenarios above (E2D), it is possible to transit DCH to E-DCH

− Periodic attempt to reconfigure to E-DCH (timer)

− Traffic volume (event 4A)

•If a UE reports event 6B2 and event 4A, and the UE services can be carried on the E-DCH, then the RNC

switches the UE from the DCH to the E-DCH during the rate increase process.

H2D

•RAB should be carried over HS-DSCH but resources are insufficient

•HS-DSCH serving cell change (change of best cell)

− New best cell does not support HS-DSCH

− New best cell does not have enough resources for HS-DSCH

D2H

•In any of the scenarios above (H2D), it is possible to transit DCH to HS-DSCH later.

− Periodic attempt to reconfigure to HS-DSCH (timer)

− Traffic volume (event 4A)

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E2D/D2E in Access State Introduction

Dynamic UL channel

According to the coverage (CPICH EcN0) in RRC CONNECT REQ

reported by UE, RNC decides which kind of uplink channel to

establish

Purpose

If the coverage is poor, EcN0 reported by UE is low. In this case,

DCH channel should be configured to guarantee the coverage

If the coverage is good, EcN0 is high. In that case, E-DCH channel

should be configured to guarantee the throughput

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E2D/D2E in Connection State

Introduction Measurements

RNC monitors the uplink throughput

UE measures and reports the state of TX power by 6A and 6B

event

E2D Conditions

Throughput in UL is below the 4B threshold for E2D

Event 6A report has been received

E2D is triggered if both above conditions are met

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E2D/D2E in Connection State

Introduction D2E Conditions

Rate rise is triggered by DCCC mechanism

Event 6B report has been received

D2E is triggered if both above conditions are met

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D2D Transition Parameters

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ReservedSwitch0- RESERVED_SWITCH_0_BIT7

Parameter name: Switch of E-DCH to DCH

Recommended value: RESERVED_SWITCH_0_BIT7 -OFF

ReservedSwitch0


D2D Transition Parameters

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Parameter Description

Recommended

value

Application

Scenarios

BeThd6A1

Event

6A1/6B1/6A2/6B2

Threshold for E-DCH

to DCH

3dB 2ms TTI HSUPA

BeThd6B1 3dB 2ms TTI HSUPA

BeThd6A2 4dB 10ms TTI HSUPA

BeThd6B2 4dB 10ms TTI HSUPA


Contents





Contents


3.1 CPC and EFACH State Transition

3.2 Always Online

3.3 Fast State Transition

3.4 Smart P2D


CPC and EFACH State Transition

HSPA+ requires two new states: CELL_DCH (CPC) state and enhanced

CELL_FACH state. The CELL_DCH (CPC) state corresponds to the CELL_DCH

state with CPC activated, and the enhanced CELL_FACH state corresponds to

the CELL_FACH state with Enhanced CELL_FACH operation activated

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CELL_DCH CELL_DCH(CPC)

Enhanced

CELL_FACH CELL_FACH

CELL_PCH

4A 4B 4A 4B 4A

4B

4B Data


New Timers to Trigger Event 4B

Type New Timer Description

CPC2F

•BeCpc2FStateTransTimer: BE service state transition timer (CPC_HS-DSCH to F/RACH)

•RtCpc2FStateTransTimer: real-time service state transition timer (CPC_HSPA to F/RACH)

D2EFACH

•BeD2EFachStateTransTimer: BE service state transition timer (DCH to E_FACH)

•BeH2EFachStateTransTimer: BE service state transition timer (HS-DSCH to E_FACH)

•RtDH2EFachStateTransTimer: real-time service state transition timer (DCH or HSPA to E_FACH)

CPC2EFACH

•BeCpc2EFachStateTransTimer: BE service state transition timer (CPC_HS-DSCH to E_FACH)

•RtCpc2EFachStateTransTimer: real-time service state transition timer (CPC_HSPA to E_FACH)


New Timers and Thresholds to Trigger

Event 4A

Type New Timer and Thresholds Description

F2CPC

The new thresholds are as follows: •BeF2CpcHTvmThd: event 4A threshold for BE service state transition (F/RACH to CPC_HS-DSCH)

•RtF2CpcTvmThd: event 4A threshold for real-time service state transition (F/RACH to CPC_HSPA)

•BeF2CpcETvmThd: event 4A threshold for BE service state transition (F/RACH to CPC_E-DCH)

The new timers are as follows: •BeF2CpcHTvmTimeToTrig: event 4A trigger time for BE service state transition (F/RACH to

CPC_HS-DSCH)

•RtF2CpcTvmTimeToTrig: event 4A trigger time for real-time service state transition (F/RACH to

CPC_HSPA)

•BeF2CpcETvmTimeToTrig: event 4A trigger time for real-time service state transition (F/RACH to

CPC_E-DCH)



Event 4A(Cont.)


EFACH2D

The new thresholds are as follows: •BeEFach2DTvmThd: event 4A threshold for BE service state transition (E_FACH to DCH)

•BeEFach2HTvmThd: event 4A threshold for BE service state transition (E_FACH to HS-DSCH)

•RtEFach2DHTvmThd: event 4A threshold for real-time service state transition (E_FACH to

DCH or HSPA)

The new timers are as follows: •BeEFach2DTvmTimeToTrig: event 4A trigger time for BE service state transition (E-FACH to

DCH)

•BeEFach2HTvmTimeToTrig: event 4A trigger time for BE service state transition (E_FACH to

HS-DSCH)

•RtEFach2DHTvmTimeToTrig: event 4A trigger time for real-time service state transition

(E_FACH to DCH/HSPA)



Event 4A(Cont.)


EFACH2CPC

The new thresholds are as follows: •BeEFach2CpcTvmThd: event 4A threshold for BE service state transition (E_FACH to

CPC_HS-DSCH)

• RtEFach2CpcTvmThd: event 4A threshold for PS real-time service state transition (E_FACH

to CPC_HSPA)

The new timers are as follows: •BeEFach2CpcTvmTimeToTrig: event 4A trigger time for BE service state transition

(E_FACH to CPC_HS-DSCH)

•RtEFach2CpcTvmTimeToTrig: event 4A trigger time for real-time service state transition

(E_FACH to CPC_HSPA)


Contents



3.2 Always Online


3.4 Smart P2D


Always Online

When the RNC detects that there is no data transmission for a

PS service, the RNC sends a request to the CN for release of the

service. The CN initiates the release procedure, requesting the

RNC to release the corresponding radio resources

The CN, however, reserves the PDP context for this PS service

of the UE. When the UE re-initiates the service of this PDP

context, it need not apply for the PDP context again. Thus, the

UE in the PS domain is always online


Always Online Procedure


Parameters of Always Online

Timer Service Type Parameter Recommended value

T1

Conversational PsInactTmrForCon 20s

Streaming PsInactTmrForStr 20s

Interactive PsInactTmrForInt 20s

Background PsInactTmrForBac 20s

T2

Conversational ProtectTmrForCon 20s

Streaming ProtectTmrForStr 20s

Interactive ProtectTmrForInt 20s

Background ProtectTmrForBac 20s

Recommended values of T1 and T2:


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3.2 Always Online


3.4 Smart P2D


Fast State Transition

Generally, when a smartphone is performing services, data transmission lasts

for 1 to 2 seconds, and the transmission interval is longer than the interval

specified by the timer for state transition from CELL_DCH to CELL_FACH,

CELL_PCH, or URA_PCH. This causes the smartphone to stay in the CELL_DCH

state for a long time even when no data is transmitted, wasting network

resources.

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Fast State Transition Parameters


value

PsInactTmrForFstDrmDch FAST DORMANCY USER T1

in CELL_DCH 4s

PsInactTmrForFstDrmFach FAST DORMANCY USER T1

in CELL_FACH 10s

PsInactTmrForPreFstDrm FAST DORMANCY USER T1

in CELL_PCH 360s

TthdForSFSTUserIdentify

Timer for determining

whether a UE is capable of

fast state transition

15s

With these timers, the smartphone can quickly change from the CELL_DCH to

CELL_FACH, CELL_PACH, or URA_PCH state in a shorter period upon

completing data transmission.


Contents



3.2 Always Online


3.4 Smart P2D


Smart P2D Transition

If severe FACH congestion occurs on a live network, the smart

CELL_PCH/URA_PCH-to-CELL_DCH (P2D) function can be used to directly

transit the state of a UE with high traffic volume from CELL_PCH or URA_PCH

to CELL_DCH. The UE does not transmit data in the CELL_FACH state. This

saves bandwidth resources on the CELL_FACH, eases FACH congestion, and

reduces the delay for processing high traffic.

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Smart P2D Transition(Cont.)

The RNC records the amount of data transmitted by a UE four

consecutive times and predicts the amount of data the UE will

transmit subsequently.

If the amount of data transmitted by a UE four consecutive times exceeds

the value of TvmThdForSmartP2D, the RNC predicts that the amount of

data the UE will transmit subsequently will remain above the value

of TvmThdForSmartP2D.

If the amount of data transmitted by a UE four consecutive times is less

than or equal to the value of TvmThdForSmartP2D, the RNC predicts

that the UE has a small amount of data to transmit subsequently.

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Smart P2D Transition Parameters

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TvmThdForSmartP2D

Parameter name: Threshold for Smart P2D

Recommended value: 510byte

TvmThdForSmartP2D

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Owo116120 Wcdma Ran14 State Transition Issue1.00

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