WCDMA UE Behaviors in Idle Mode.pdf

(1)

Revision Record

Course Code Product Product Version Course Version ISSUE

OWO114010 SingleRAN RNO

UO

SingleRAN5.0 Feature

Version 1.01

Developer/Modifier Time Approver New/Update

Ding Qi/53895 2010-03 New

Li Zhihai/131679 2011-08 Update

(2)

www.huawei.com

WCDMA UE Behaviors

in Idle Mode

(3)

Foreword



UE behaviors in idle mode include:

 PLMN selection

 System information reception  Cell selection and reselection  Location registration

 Paging procedure  Access procedure

(4)

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

 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)

(5)

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

(6)

1. PLMN Selection

2. System Information Reception

3. Cell Selection and Reselection

4. Location Registration

5. Paging Procedure

6. Access Procedure

(7)

1. PLMN Selection

2. System Information Reception

3. Cell Selection and Reselection

4. Location Registration

5. Paging Procedure

(8)

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

(9)

Cell Search (Cont.)

Slot synchronization

Frame synchronization and code-group identification

Primary scrambling code identification

(10)

(11)

PLMN Selection (Cont.)



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

then the UE selects the registered PLMN or its equivalent

PLMNs



If no registered PLMN or equivalent PLMNs is available,

or if 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

(12)

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 lowest

 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

(13)

1. PLMN Selection

2. System Information Reception

3. Cell Selection and Reselection

4. Location Registration

5. Paging Procedure

(14)

Structure of System Information



System information is organized as a tree, including:

 MIB (Master Information Block)  SB (Scheduling Block)

(15)

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

(16)

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

(17)

1. PLMN Selection

2. System Information Reception

3. Cell Selection and Reselection

4. Location Registration

5. Paging Procedure

(18)

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

(19)

(20)

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

(21)

Cell Selection Criteria

min qual qualmeas qual

Q

S





on compensati rxlev rxlevmeas rxlev

Q

P

S





_min





Criterion S is used by the UE to judge whether the cell is

suitable to camped on

(22)

Parameters of S Criterion



Qqualmin

 Parameter name: Min quality level

 Recommended value: -18, namely -18dB



Qrxlevmin

 Parameter name: Min Rx level

(23)

Parameters of S Criterion (Cont.)



MaxAllowedUlTxPower

 Parameter name: Max allowed UE UL TX power  Recommended value: 24, namely 24dBm

(24)

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

(25)

Measurement Start Criteria



Intra-frequency measurement:

S

_qual

≤ S

_intrasearch

↓

Q

_qualmeas

− Q

_qualmin

≤ S

_intrasearch

↓

(26)

Measurement Start Criteria (Cont.)



Inter-frequency measurement:

S

_qual

≤ S

_intersearch

↓

Q

_qualmeas

− Q

_qualmin

≤ S

_intersearch

↓

(27)

Measurement Start Criteria (Cont.)



Inter-RAT measurement:

S

_qual

≤ S

_searchRATm

↓

Q

_qualmeas

− Q

_qualmin

≤ S

_searchRATm

↓

(28)

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

(29)

(Cont.)



IdleSintersearch

 Parameter name: Inter-freq cell reselection threshold for

idle mode

 Recommended value: 127, namely none



ConnSintersearch

 Parameter name: Inter-freq cell reselection threshold for

connected mode

(30)

(Cont.)



SsearchRat

 Parameter name: Inter-RAT cell reselection threshold  Recommended value: 127, namely none

(31)

(32)

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:

n s offset n meas n

Q

R

, ,





hysts s meas s

Q

R



_,



(33)

(34)

Parameters of R Criteria



QualMeas

 Parameter name: Cell Sel-reselection quality measure  Recommended value: CPICH_ECNO



Treselections

 Parameter name: Reselection delay time  Recommended value: 1, namely 1s

(35)

Parameters of R Criteria (Cont.)



IdleQhyst1s

 Parameter name: Hysteresis 1 for idle mode  Recommended value: 2, namely 4dB



ConnQhyst1s

 Parameter name: Hysteresis 1 for connected mode  Recommended value: 2, namely 4dB

(36)

Parameters of R Criteria (Cont.)



IdleQhyst2s

 Parameter name: Hysteresis 2 for idle mode  Recommended value: 2, namely 4dB



ConnQhyst2s

 Parameter name: Hysteresis 2 for connected mode  Recommended value: 2, namely 4dB

(37)

Parameters of R Criteria (Cont.)



IdleQoffset1sn

 Parameter name: IdleQoffset1sn

 Recommended value: 0, namely 0dB



ConnQoffset1sn

 Parameter name: ConnQoffset1sn  Recommended value: 0, namely 0dB

(38)

Parameters of R Criteria (Cont.)



IdleQoffset2sn

 Parameter name: IdleQoffset2sn  Recommended value: 0, namely 0dB



ConnQoffset2sn

 Parameter name: ConnQoffset2sn  Recommended value: 0, namely 0dB

(39)

1. PLMN Selection

2. System Information Reception

3. Cell Selection and Reselection

4. Location Registration

5. Paging Procedure

(40)

Location Registration



The location registration includes:

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



The types of location registration:

 Normal location registration  Periodic location registration

(41)

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

(42)

IMSI Attach/Detach



The IMSI attach/detach process facilitates the fast

location registration of the UE in specific conditions

(43)

Parameters of Location Registration



T3212

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



ATT

 Parameter name: Attach/detach indication  Recommended value: ALLOWED

(44)

1. PLMN Selection

2. System Information Reception

3. Cell Selection and Reselection

4. Location Registration

5. Paging Procedure

6. Access Procedure

(45)

Paging Initiation



CN initiated paging:

 Establish a signaling connection



UTRAN initiated paging:

 Trigger the cell update procedure

(46)

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 1

CN RNC1 RNC2 NODEB1.1 NODEB2.1 UE RANAP RANAP RANAP RANAP PCCH: PAGING TYPE 1 PAGING PAGING

(47)

Paging Type 2



If UE is in CELL_DCH or CELL_FACH state, the paging

message will be transmitted on DCCH with paging type 2

CN SRNC UE RANAP RANAP PAGING RRC RRC DCCH: PAGING TYPE 2

(48)

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



The value for the DRX paging cycle length is determined

as follows:

(49)

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**

(50)

DRX Procedure (Cont.)

 In FDD the UE shall monitor its paging indicator in the PICH frame with SFN given by the Paging Occasion

 The Page Indicator in the frame to use is calculated by using the following formula:

 Where, PI = (IMSI div 8192) mod N_P

 N_P is the number of paging indicators in one PICH frame



 













SFN SFN SFN SFN



Np Np PI q mod 144 144 mod 512 / 64 / 8 / 18 _                  

(51)

DRX Procedure (Cont.)

PICH

Associated S-CCPCH frame PICH frame containing paging indicator



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

(52)

Parameters of DRX



DRXCyclelenCoef

 Parameter name: DRX cycle length coefficient  Recommended value: 6



PICHMode

 Parameter name: PICH mode  Recommend value: V36

(53)

Parameters of DRX (Cont.)



MaccPageRepeatTimes

 Parameter name: Number of page re-TX  Recommended value: 1

(54)

1. PLMN Selection

2. System Information Reception

3. Cell Selection and Reselection

4. Location Registration

5. Paging Procedure

(55)

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 state or CELL_DCH state from the idle mode

 After releasing RRC connection, UE will switch to the idle

(56)

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

(57)

Random Access Channel

AICH access slots 10 ms #0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14 p-a #0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14 PRACH access slots SFN mod 2 = 0 SFN mod 2 = 1 10 ms Access slot set 1 Access slot set 2

(58)

RACH Sub-Channels

SFN mod 8

Random access sub-channels number

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

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

(59)

Random Access Channel Case

 Sub Channels how to use Access Slots ?

(60)

Access Service Class



The PRACH resources can be classified into several ASCs,

so as to provide RACH applications with different

priorities

(61)

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

(62)

Mapping between AC and ASC



The AC-ASC mapping information is optional and used

for the System Information Block 5 (SIB5) only

(63)

Random Access Procedure

START

Choose a RACH sub channel from available 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 RACH

message 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 Nack on 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

(64)

(65)

RRC Connection Message



Typical RRC connection messages:

 RRC_CONNECTION_REQUEST

 RRC_CONNECTION_SETUP

 RRC_CONNECTION_SETUP_COMPLETE

(66)

UE Timers and Constants in Idle Mode



T300

 Parameter name: Timer 300 [ms]

 Recommended value: D2000, namely 2s



N300

 Parameter name: Constant 300  Recommended value: 3

(67)

(Cont.)

(68)

Type and Bit Rate



RrcCause

 Parameter name: Cause of RRC connection establishment  Recommended value: refer to next page



SigChType

 Parameter name: Channel type for RRC establishment  Recommended value: refer to next page

(69)

(70)

(71)

WCDMA UE Behaviors in Idle Mode.pdf

Revision Record

WCDMA UE Behaviors

in Idle Mode

Foreword

UE behaviors in idle mode include:

References

Objectives

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

Contents

1. PLMN Selection

2. System Information Reception

3. Cell Selection and Reselection

4. Location Registration

5. Paging Procedure

6. Access Procedure

Contents

1. PLMN Selection

2.

System Information Reception

3.

Cell Selection and Reselection

4.

Location Registration

5.

Paging Procedure

Cell Search

UE does not have UTRAN carrier information:

UE has UTRAN carrier information:

Cell Search (Cont.)

PLMN Selection (Cont.)

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

then the UE selects the registered PLMN or its equivalent

PLMNs

If no registered PLMN or equivalent PLMNs is available,

or if registration fails, the UE performs one of the

following two procedures, depending on its operating

mode:

PLMN Selection (Cont.)

Contents

1.

PLMN Selection

2. System Information Reception

3.

Cell Selection and Reselection

4.

Location Registration

5.

Paging Procedure

Structure of System Information

System information is organized as a tree, including:

System 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

Contents

1.

PLMN Selection

2.

System Information Reception

3. Cell Selection and Reselection

4.

Location Registration

5.

Paging 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:

Cell Selection (Cont.)

Two types of cell selection:

Cell Selection Criteria

Q

Q

S



