Owo113010 Wcdma Ue Behaviors in Idle Mode Ran11 Issue1.01

WCDMA UE Behaviors in Idle Mode

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Copyright 2009 Huawei Technologies Co., Ltd. All rights reserved.

Foreword UE behaviors in idle mode include:

PLMN selection

System information reception

Cell selection and reselection

Copyright 2009 Huawei Technologies Co., Ltd. All rights reserved. Page1

Location registration

Paging procedure

Access procedure

References 3GPP TS 22.011: Service Accessibility

3GPP TS 23.122: NAS Functions Related to Mobile Station (MS) in Idle Mode

3GPP TS 24.008: Mobile Radio Interface Layer 3 Specification; Core Network Protocols - Stage 3


Core Network Protocols - Stage 3

3GPP TS 25.304: UE Procedures in Idle Mode and Procedures for Cell Reselection in Connected Mode

3GPP TS 25.331: Radio Resource Control (RRC) 3GPP TS 31.102: Characteristics of The USIM Application

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

Describe the working principles of the UE Behaviors in Idle Mode feature

Perform parameters modification of the UE Behaviors in Idle


Mode feature

Contents1. PLMN Selection

2. System Information Reception

3. Cell Selection and Reselection

4. Location Registration


5. Paging Procedure

6. Access Procedure






5. Paging Procedure

6. Access Procedure

Cell Search UE does not have UTRAN carrier information:

In order to find a suitable cell to stay, UE will scan all the frequencies in UTRAN. In each carrier, UE just need to find a cell with best signal


UE has UTRAN carrier information:

UE will try whether the original cell is suitable to stay. If not, UE still need to scan all the frequencies in UTRAN to find a suitable cell in PLMN

Cell Search (Cont.)Slot synchronization


Frame synchronization and code-group identification

Primary scrambling code identification

PLMN Selection When the UE is switched on, or the coverage is restored, or the

UE selects a cell that belongs to another PLMN, then the UE selects the registered PLMN or its equivalent PLMN

If no registered PLMN or equivalent PLMN is available, or if registration fails, the UE performs one of the following two


registration fails, the UE performs one of the following two procedures, depending on its operating mode: Automatic PLMN selection: the UE automatically selects a PLMN

according to the priority order

Manual PLMN selection: the UE shows all available PLMNs to the subscriber. The subscriber then selects a PLMN

PLMN Selection (Cont.) Automatic PLMN selection: UE can select a PLMN from the Home

PLMNs (HPLMNs) and roam in the Visited PLMN (VPLMN) Selecting from the HPLMNs: UE maintains a list of allowed and

available PLMNs in priority order. When selecting a PLMN, the UE searches for the PLMNs from the highest priority to the lowestRoaming in the VPLMN: UE periodically searches for the HPLMN and


Roaming in the VPLMN: UE periodically searches for the HPLMN and higher priority PLMNs for better services

Manual PLMN selection: UE maintains a list of allowed and available PLMNs in priority order. When selecting a PLMN, the UE indicates the list to the subscriber who will select a PLMN, and then camps on the selected PLMN






5. Paging Procedure

6. Access Procedure

Structure of System Information System information is organized as a tree, including:

MIB (Master Information Block) SB (Scheduling Block) SIB (System Information Block)


System Information SIB1: contains the system information for NAS and the

timer/counter for UE SIB2: contains the URA information SIB3: contains the parameters for cell selection and cell re-

selection


SIB5: contains parameters for the common physical channels of the cell

SIB7: contains the uplink interference level and the refreshing timer for SIB7

SIB11: contains measurement controlling information

Reception of System Information The UE shall read system information broadcast on a BCH

transport channel when the UE is in idle mode or in connected mode, that is, in CELL_FACH, CELL_PCH, or URA_PCH state







5. Paging Procedure

6. Access Procedure

Cell Selection When the PLMN is selected and the UE is in idle mode, the

UE starts to select a cell to camp on and to obtain services

There are four states involved in cell selection:

Camped normally


Any cell selection

Camped on any cell

Connected mode

Cell Selection (Cont.) Two types of cell selection:

Initial cell selection

If no cell information is stored for the PLMN, the UE starts this procedure


Stored information of cell selection If cell information is stored for the PLMN, the UE starts this

procedure

Cell Selection Criteria

QQS =

Criterion S is used by the UE to judge whether the cell is suitable to camped on

Criterion S: Srxlev > 0 & Squal > 0, where:


minqualqualmeasqual QQS =oncompensatirxlevrxlevmeasrxlev PQQS = min

Parameters of S Criterion Qqualmin

Parameter name: Min quality level

Recommended value: -18, namely -18dB

Qrxlevmin


Qrxlevmin Parameter name: Min Rx level

Recommended value: -58, namely -115dBm

Parameters of S Criterion (Cont.) MaxAllowedUlTxPower

Parameter name: Max allowed UE UL TX power

Recommended value: 24, namely 24dBm


Cell Reselection The signal strength of both serving cell and neighboring

cells varies with the movement of a UE and so the UE needs to select the most suitable cell to camp on. This process is called cell reselection


Cell reselection process:

Measurement start criteria

Cell reselection criteria

Measurement Start Criteria Intra-frequency measurement:

Squal Sintrasearch

Qqualmeas Qqualmin Sintrasearch


Qqualmeas Qqualmin Sintrasearch

Qqualmeas Qqualmin + Sintrasearch

Measurement Start Criteria (Cont.) Inter-frequency measurement:

Squal Sintersearch

Qqualmeas Qqualmin Sintersearch


Qqualmeas Qqualmin Sintersearch

Qqualmeas Qqualmin + Sintersearch

Measurement Start Criteria (Cont.) Inter-RAT measurement:

Squal SsearchRATm

Qqualmeas Qqualmin SsearchRATm


Qqualmeas Qqualmin SsearchRATm

Qqualmeas Qqualmin + SsearchRATm

Parameters of Measurement Start Criteria

IdleSintrasearch Parameter name: Intra-freq cell reselection threshold for idle

mode

Recommended value: 127, namely none


ConnSintrasearch Parameter name: Intra-freq cell reselection threshold for

connected mode


Parameters of Measurement Start Criteria (Cont.) IdleSintersearch

Parameter name: Inter-freq cell reselection threshold for idle mode



ConnSintersearch Parameter name: Inter-freq cell reselection threshold for

connected mode


Parameters of Measurement Start Criteria (Cont.) SsearchRat

Parameter name: Inter-RAT cell reselection threshold



Measurement Start Criteria Description


Cell Reselection Criteria Criterion R is used for intra-frequency, inter-frequency and

inter-RAT cell reselection

The cell-ranking criterion R is defined by:

hystssmeass QQR += ,


nsoffsetnmeasn QQR ,, =hystssmeass QQR += ,

Hysteresis and Time IntervalQuality

Rn

Qmeas,nQhyst,s


TimeTreselection

Rn

Rs

Qmeas,sQoffsets,n

Parameters of R Criteria QualMeas

Parameter name: Cell Sel-reselection quality measure

Recommended value: CPICH_ECNO

Treselections


Treselections

Parameter name: Reselection delay time

Recommended value: 1, namely 1s

Parameters of R Criteria (Cont.) IdleQhyst1s

Parameter name: Hysteresis 1 for idle mode

Recommended value: 2, namely 4dB

ConnQhyst1s


ConnQhyst1s

Parameter name: Hysteresis 1 for connected mode


Parameters of R Criteria (Cont.) IdleQhyst2s

Parameter name: Hysteresis 2 for idle mode


ConnQhyst2s


ConnQhyst2s

Parameter name: Hysteresis 2 for connected mode


Parameters of R Criteria (Cont.) IdleQoffset1sn

Parameter name: IdleQoffset1sn


ConnQoffset1sn


ConnQoffset1sn Parameter name: ConnQoffset1sn


Parameters of R Criteria (Cont.) IdleQoffset2sn

Parameter name: IdleQoffset2sn


ConnQoffset2sn


ConnQoffset2sn Parameter name: ConnQoffset2sn







5. Paging Procedure

6. Access Procedure

Location Registration The location registration includes:

Location update (for non-GPRS) Route update (for GPRS)

The types of location registration:


The types of location registration:

Normal location registration

Periodic location registration

IMSI attach/detach

Periodic Location Registration Periodic location registration is controlled by a Periodic

Location Update timer (T3212, for non-GPRS operation) or a Periodic Routing Area Update timer (T3312, for GPRS operation)


T3212 is set through T3212 on the RNC side

T3312 is set on the CN side

IMSI Attach/Detach The IMSI attach/detach process facilitates the fast location

registration of the UE in specific conditions

IMSI attach/detach is set through ATT on the RNC side


Parameters of Location Registration T3212

Parameter name: Periodical location update timer [6min] Recommended value: 10, namely 60min

ATT


ATT

Parameter name: Attach/detach indication

Recommended value: ALLOWED






5. Paging Procedure

6. Access Procedure

Paging Initiation CN initiated paging:

Establish a signaling connection

UTRAN initiated paging:

Trigger the cell update procedure


Trigger the cell update procedure

Trigger reading of updated system information

Paging Type 1 If UE is in the idle or CELL/URA_PCH state, the paging

message will be transmitted on PCCH with paging type 1CN RNC1 RNC2 NODEB1.1 NODEB2.1 UE

RANAPRANAP

PAGING


RANAP RANAP

PCCH: PAGING TYPE 1

PAGING

PCCH: PAGING TYPE 1

Paging Type 2 If UE is in CELL_DCH or CELL_FACH state, the paging

message will be transmitted on DCCH with paging type 2CN SRNC UE

PAGING


RANAPRANAP

PAGING

RRCRRC

DCCH: PAGING TYPE 2

Typical Call Flow of UE UE NAS UE AS NSS M SC

paging

AUTHENTICATION REQ UEST

AUTHENTICATION RESPO NSE

RR_SECURITY_C ONTRO L_REQ

paging

RR_EST_REQ (PAG IN G RESPO NSE) RR_PAING _IND

IN ITIAL_DIREC T_TRAN SFER(PAG ING RESPO NSE)

RANAPRANAP

RR C setup process


RR_SECURITY_C ONTRO L_REQ(IK CK)

Security m ode contro l

SETUP

C ALL CO NFIRM

ALER T

CO NNECT

CO NNEC T ACKNO W LEDG E

R AB setup process

DRX Procedure To reduce power consumption, the UE can read the

information from the PICH only at a particular time. This is known as the Discontinuous Reception (DRX) technology. The interval between two consecutive periods of time is called DRX cycle


called DRX cycle

The value for the DRX paging cycle length is determined as follows:

DRX Cycle Length MAX (2k, PBP) frames

DRX Procedure (Cont.) The value of the Paging Occasion is determined as follows:

Paging Occasion (CELL SFN) = {(IMSI div K) mod (DRX cycle length div PBP)} * PBP + n * DRX cycle length + Frame Offset


+ n * DRX cycle length + Frame Offset

DRX Procedure (Cont.) In FDD the UE shall monitor its paging indicator in the PICH

frame with SFN given by the Paging Occasion

The Paging Indicator to use is calculated by using the following formula:


PI = (IMSI div 8192) mod NP

DRX Procedure (Cont.) Through DRX, UE only listens to PICH at certain predefined

time. And UE will read the paging information on SCCPCH if the paging indicator is 1

Time offset between PICH and SCCPCH:


PICH

Associated S-CCPCH frame

PICH frame containing paging indicator

Parameters of DRX DRXCyclelenCoef

Parameter name: DRX cycle length coefficient

Recommended value: 6

PICHMode


PICHMode

Parameter name: PICH mode

Recommend value: V36

Parameters of DRX (Cont.) MaccPageRepeatTimes

Parameter name: Number of page re-TX








5. Paging Procedure

6. Access Procedure

Two Working Modes of UE Idle mode:

After turning on, UE will stay in idle mode

Connected mode:

UE will switch to connected mode which could be CELL_FACH


UE will switch to connected mode which could be CELL_FACH state or CELL_DCH state from the idle mode

After releasing RRC connection, UE will switch to the idle mode from the connected mode

Random Access Procedure Definition:

Random access procedure is initiated by UE in order to get service from the system. Meanwhile, the access channels are allocated to the UE by system


Random Access Channel

AICH accessslots

#0 #1 #2 #3 #14#13#12#11#10#9#8#7#6#5#4p-a

SFN mod 2 = 0 SFN mod 2 = 1


10 ms

#0 #1 #2 #3 #14#13#12#11#10#9#8#7#6#5#4

PRACHaccess slots

10 ms

Access slot set 1 Access slot set 2

RACH Sub-Channels

SFN mod 8

Random access sub-channels number0 1 2 3 4 5 6 7 8 9 10 11

0 0 1 2 3 4 5 6 71 12 13 14 8 9 10 11

The access slots of different RACH sub-channels are illustrated by the following table:


1 12 13 14 8 9 10 112 0 1 2 3 4 5 6 73 9 10 11 12 13 14 84 6 7 0 1 2 3 4 55 8 9 10 11 12 13 146 3 4 5 6 7 0 1 27 8 9 10 11 12 13 14

Access Service Class The PRACH resources can be classified into several ASCs,

so as to provide RACH applications with different priorities


Access Control Access Control is used by network operators to prevent

overload of radio access channels under critical conditions

Access class 0 ~ Access Class 9

Access class 11 ~ Access Class 15


Access class 10

Mapping between AC and ASC The AC-ASC mapping information is optional and used for

the System Information Block 5 (SIB5) only


Random Access ProcedureSTART

Choose a RACH sub channel fromavailable ones

Get available signatures

Set Preamble Retrans Max

Set Preamble_Initial_Power

Send a preamble

Check the corresponding AI

Change message part power by p-m based on preamble power

Set physical status to be RACHmessage transmitted Set physical status to be Nack

on AICH received

Choose a access slot again

Counter > 0 & Commanded Preamble power- maximum allowed power < 6

dB

Choose a signature and increase preamble transmit power

Set physical status to be Nackon AICH received

Get negative AI

No AI

Report the physical status to MAC

END

Get positive AI

The counter of preamble retransmit Subtract by 1, Commanded preamble power

increased by Power Ramp Step

N

Y

Send the corresponding message part

RRC Connection Message Typical RRC connection messages:

RRC_CONNECTION_REQUEST

RRC_CONNECTION_SETUP

RRC_CONNECTION_SETUP_COMPLETE


RRC_CONNECTION_SETUP_COMPLETE

RRC_CONNECTION_RELEASE

UE Timers and Constants in Idle Mode T300

Parameter name: Timer 300 [ms] Recommended value: D2000, namely 2s

N300


N300

Parameter name: Constant 300


UE Timers and Constants in Idle Mode (Cont.) T312

Parameter name: Timer 312 [s] Recommended value: 6, namely 6s

N312


N312

Parameter name: Constant 312

Recommended value: D1, namely 1

RRC Connection Establish Channel Type and Bit Rate RrcCause

Parameter name: Cause of RRC connection establishment

Recommended value: refer to next page

SigChType


SigChType Parameter name: Channel type for RRC establishment

Recommended value: refer to next page

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Owo113010 Wcdma Ue Behaviors in Idle Mode Ran11 Issue1.01