WCDM Cellreselection

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Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved.

WCDMA UE Behaviors

in Idle Mode

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Page1Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved.

Foreword

UE behaviors in idle mode include :

PLMN selection

System information reception

Cell selection and reselection

Location registration

Paging procedure

Access procedure

PLMN selection

Used to ensure that the PLMN selected by the UE properly provides services.

Cell selection and reselection

Used to ensure that the UE finds a suitable cell to camp on.

Location registration

Used for the network to trace the current status of the UE and to ensure that the UE is campedon the network when the UE does not perform any operation for a long period.

System information reception

The network broadcasts the network information to a UE which camps on the cell to control thebehaviors of the UE.

Paging

Used for the network to send paging messages to a UE which is in idle mode, CELL_PCHstate, or URA_PCH state.

Access

From the view of access stratum, access is the procedure UE shift from idle mode to

connected mode.

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Contents

1. PLMN Selection

2. System Information Reception

3. Cell Selection and Reselection

4. Location Registration

5. Paging Procedure

6. Access Procedure

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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 about UTRAN in order to

find a suitable cell in PLMN

Typical scenario of first occasion is the first time a new UE is put into use.

The second occasion is very common.

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Cell Search

Slot synchronization

Frame synchronization andcode-group identification

Primary Scrambling codeidentification

Step 1: Slot synchronization

During the first step of the cell search procedure the UE uses the primary synchronisation code(PSC) to acquire slot synchronisation to a cell.

Step 2: Frame synchronization and code-group identification

During the second step of the cell search procedure, the UE uses the secondarysynchronisation code (SSC) to find frame synchronisation and identify the code group of thecell found in the first step.

Step 3: Primary Scrambling code identification:

During the last step of the cell search procedure, the UE determines the exact primaryscrambling code used by the found cell. The primary scrambling code is typically identifiedthrough symbol-by-symbol correlation over the CPICH with all codes within the code groupidentified in the second step.

If the UE has received information about which scrambling codes to search for, steps 2 and 3above can be simplified.

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PLMN Selection

UE shall maintain a list of allowed PLMN types. In the

PLMN list, the UE arranges available PLMNs by priorities.

When selecting a PLMN, it searches the PLMNs from the

high priority to the low.

The UE selects a PLMN from HPLMNs or VPLMNs.

UE can get the system information from PCCPCH, and the PLMN information is transmitted inMIB of PCCPCH

After getting the MIB, UE can judge weather the current PLMN is the right one. If so, UE willget the SIB scheduling information from the MIB; if not, UE will search another carrier, do thisprocedure again

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PLMN Selection ( Cont. )

PLMN Selection in HPLMNs

Automatic PLMN Selection Mode

The UE selects an available and suitable PLMN from the whole

band according to the priority order

Manual PLMN Selection Mode

The order of manual selection is the same as that of automatic

selection.

The priority order for automatic PLMN selection mode

The PLMN selected by theUE before automatic PLMNselection

Previously selected PLMN6

The PLMNs are arranged indescending order of signalquality.

Other PLMN/access technology combinations

excluding the previously selected PLMN5

The PLMNs are arranged inrandom order

Other PLMN/access technology combinations withthe high quality of received signals excluding the

previously selected PLMN4

The PLMNs are arranged in priority order

PLMNs contained in the "Operator ControlledPLMN Selector with Access Technology" data fieldin the SIM excluding the previously selected PLMN

3

The PLMNs are arranged in priority order

PLMNs contained in the "User Controlled PLMNSelector with Access Technology" data field in theSIM excluding the previously selected PLMN

2

Home PLMNsHPLMNs1

Remark PLMN typeOrder

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PLMN Selection ( Cont. )

PLMN Selection in VPLMNs

If a UE is in a VPLMN, it scans the user controlled PLMN

selector field or the operator controlled PLMN selector field

in the PLMN list to find the HPLMN or the PLMN with higher

priority according to the requirement of the automatic PLMN

selection mode.

A value of T minutes may be stored in the SIM. T is either in the range from 6 minutes to 8hours in 6-minute steps or it indicates that no periodic attempts shall be made. If no value isstored in the SIM, a default value of 60 minutes is used.

After the UE is switched on, a period of at least 2 minutes and at most T minutes shall elapsebefore the first attempt is made.

The UE shall make an attempt if the UE is on the VPLMN at time T after the last attempt.

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Contents

1. PLMN Selection




5. Paging Procedure

6. Access Procedure

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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 is used for the network to broadcast network information to UEs campingon a cell so as to control the behavior of UEs.

MIBWhen selecting a new cell, the UE reads the MIB. The UE may locate the MIB bypredefined scheduling information. The IEs in the MIB includes MIB value tag, PLMN

type, PLMN identity, reference and scheduling information for a number of SIBs in acell or one or two SBs in a cell.

SBScheduling Block (SB) gives reference and scheduling information to other SIBs. Thescheduling information of a SIB may be included in only one of MIB and SB.

SIBSystem Information Block (SIB) contains actual system information. It consists of system information elements (IEs) with the same purpose.

Scheduling information for a system information block may only be included in either themaster information block or one of the scheduling blocks.

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System InformationSIB1: Contains the system information for NAS and thetimer/counter for UE

SIB2: Contains the URA informationSIB3: 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 refreshingtimer for SIB7

SIB11: Contains measurement controlling information

SIB4: Contains parameters for cell selection and cell re-selection while UE is in connectedmode

SIB6: Contains parameters for the common physical channels of the cell while UE is inconnected mode

SIB8: Contains the CPCH static information

SIB9: Contains the CPCH dynamic information

SIB10: Contains information to be used by UEs having their DCH controlled by a DRACprocedure. Used in FDD mode only. To be used in CELL_DCH state only. Changes so often,its decoding is controlled by a timer

SIB12: Contains measurement controlling information in connecting mode

SIB13: Contains ANSI-41 system information

SIB14: Contains the information in TDD mode

SIB15: Contains the position service information

SIB16: Contains the needed pre-configuration information for handover from other RAT toUTRAN

SIB17: Contains the configuration information for TDDSIB18: Contains the PLMN identities of the neighboring cells

To be used in shared networks to help with the cell reselection process

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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

Camped normally: The cell that UE camps on is called the suitable cell. In this state, the UEobtains normal service.

Any cell selection: In this state, the UE shall attempt to find an acceptable cell of an any PLMNto camp on, trying all RATs that are supported by the UE and searching first for a high qualitycell

Camped on any cell: The cell that UE camps on is called the acceptable cell. In this state theUE obtains limited service. The UE shall regularly attempt to find a suitable cell of the selectedPLMN, trying all RATs that are supported by the UE.

Connected mode: When returning to idle mode, the UE shall use the procedure Cell selectionwhen leaving connected mode in order to find a suitable cell to camp on and enter stateCamped normally. If no suitable cell is found in cell reselection evaluation process, the UEenters the state Any cell selection.

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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 cell selection

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

procedure.

Initial cell selection: If no cell information is stored for the PLMN, the UE starts the initial cellselection. For this procedure, the UE need not know in advance which Radio Frequency (RF)channels are UTRA bearers. The UE scans all RF channels in the UTRA band according to itscapabilities to find a suitable cell of the selected PLMN. On each carrier, the UE need onlysearch for the strongest cell. Once a suitable cell is found, this cell shall be selected.

Stored information cell selection: For this procedure, the UE need know the central frequencyinformation and other optional cell parameters that are obtained from the measurement controlinformation received before, such as scrambling codes. After this procedure is started, the UEselects a suitable cell if it finds one. Otherwise, the "Initial cell selection" procedure is triggered.

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Parameters of S Criterion

QUALMEAS

Parameter name: Cell Se-reselection quality measure

Recommended value: CPICH_ECNO

QQUALMIN

Parameter name: Min quality level

Recommended value: -18, namely -18dB

QUALMEAS Parameter name: Cell Sel-reselection quality measure

Value range: CPICH_ECNO(CPICH Ec/N0),CPICH_RSCP(CPICH RSCP)

Physical unit: None.

Content: Cell selection and reselection quality measure, may be set to CPICH Ec/N0or CPICH RSCP.

Recommended value: CPICH_ECNO.

QQUALMIN Parameter name: Min quality level

Value range: -24~0

Physical value range: -24~0; step: 1

Physical unit: dB

Content: The minimum required quality level corresponding to CPICH Ec/No. The UEcan camp on the cell only when the measured CPICH Ec/No is greater than the valueof this parameter.

Recommended value: -18Set this parameter through ADD CELLSELRESEL, query it through LSTCELLSELRESEL, and modify it through MOD CELLSELRESEL.

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Parameters of S Criterion

QRXLEVMIN

Parameter name: Min Rx level

Recommended value: -58, namely -115dBm

MAXALLOWEDULTXPOWER

Parameter name: Max allowed UE UL TX power

Recommended value: 21, namely 21dBm

QRXLEVMIN Parameter name: Min Rx level

Value range: -58~-13.

Physical value range: -115~-25; step: 2 (-58:-115; -57:-113; ..., -13:-25 ).

Physical unit: dBm.

Content: The minimum required RX level corresponding to CPICH RSCP. The UE cancamp on the cell only when the measured CPICH RSCP is greater than the value of this parameter.

Recommended value: -58.

Set this parameter through ADD CELLSELRESEL, query it through LSTCELLSELRESEL, and modify it through MOD CELLSELRESEL.

MAXALLOWEDULTXPOWER Parameter name: Max allowed UE UL TX power

Value range: -50~33

Physical value range: -50~33; step: 1

Physical unit: dBmContent: The maximum allowed uplink transmit power of a UE in the cell, which isrelated to the network planning. Content: Allowed maximum power transmitted onRACH in the cell. It is related to network planning.

Recommended value: -21


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Measurement Start Criteria ( Cont. )

Intra-frequency measurement

Squal

Sintrasearch

Qqualmeas Qqualmin S intrasearch

Qqualmeas Qqualmin + S intrasearch

Parameters of the measurement start criteria

Minimum required quality level in the cell (dB) .Qqualmin

Measurement threshold for UE to trigger inter-RAT cell reselection,compared with S qual .

S searchRATm

Measurement threshold for UE to trigger inter-frequency cell reselection,compared with S qual .

S intersearch

Measurement threshold for UE to trigger intra-frequency cell reselection,compared with S qual .

S intrasearch

Cell quality value (dB)S qual

DescriptionName

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Measurement Start Criteria ( Cont. )

Inter-frequency measurement

Squal

Sintersearch

Qqualmeas Qqualmin S intersearch

Qqualmeas Qqualmin + S intersearch

Parameters of the measurement start criteria

Minimum required quality level in the cell (dB) .Qqualmin

Measurement threshold for UE to trigger inter-RAT cell reselection,compared with S qual .

S searchRATm

Measurement threshold for UE to trigger inter-frequency cell reselection,compared with S qual .

S intersearch

Measurement threshold for UE to trigger intra-frequency cell reselection,compared with S qual .

S intrasearch

Cell quality value (dB)S qual

DescriptionName

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Parameters of Measurement Start Criteria

IDLESINTRASEARCH

Parameter name: Intra-freq cell reselection threshold for idle

mode

Recommended value: None

CONNSINTRASEARCH

Parameter name: Intra-freq cell reselection threshold for

connected mode

Recommended value: None

IDLESINTRASEARCH Parameter name: Intra-freq cell reselection threshold for idle mode

Value range: {{-16~10},{127}} .

Physical value range: -32~20; step: 2.

Physical unit: dB.

Content: A threshold for intra-frequency cell reselection in idle mode. When the quality(CPICH Ec/No measured by UE) of the serving cell is lower than this threshold plusthe [Qqualmin] of the cell, the intra-frequency cell reselection procedure will be started.

Recommended value: None.


CONNSINTRASEARCH Parameter name: Intra-freq cell reselection threshold for connected mode

Value range: {{-16~10},{127}} .

Physical value range: -32~20; step: 2.

Physical unit: dBContent: A threshold for intra-frequency cell reselection in connect mode. When thequality (CPICH Ec/No measured by UE) of the serving cell is lower than this thresholdplus the [Qqualmin] of the cell, the intra-frequency cell reselection procedure will bestarted.

Recommended value: None.


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Cell Reselection Criteria

Criterion R is used for intra-frequency, inter-frequency cells

and inter-RAT cell reselection.

The cell-ranking criterion R is defined by :

n soffset nmeasnQQ R

,,

hysts smeas s QQ R ,

The cells are ranked according to R criteria specified above ,deriving QQ meas,nmeas,n and QQ meas,smeas,s andcalculating R value.

In Rs, s means serving cell. In Rn, n means neighbor cell.

The offset Qoffset1s,n is used for Qoffsets,n to calculate Rn . The hysteresis Qhyst1s is usedfor Qhysts to calculate Rs .

If a TDD or GSM cell is ranked as the best cell, the UE shall reselect that TDD or GSM cell.

If an FDD cell is ranked as the best cell and the quality measure for cell selection andreselection is set to CPICH RSCP, the UE shall reselect that FDD cell.

If an FDD cell is ranked as the best cell and the quality measure for cell selection andreselection is set to CPICH Ec/N0, the UE shall perform a second ranking of the FDD cellsaccording to the R criteria specified above.

In this case, however, the UE uses the measurement quantity CPICH Ec/N0 for deriving theQmeas,n and Qmeas,s and then calculating the R values of the FDD cells. The offsetQoffset2s,n is used for Qoffsets,n to calculate Rn, the hysteresis Qhyst2s is used for Qhysts tocalculate Rs.

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Hysteresis and Time Interval

TimeTreselection

Quality

Rn

Rs

Qmeas,n

Qmeas,s

Qhyst,s

Qoffsets,n

In all the previous cases, the UE can reselect a new cell only when the following conditions aremet:

The new cell is better ranked than the serving cell during a time interval Treselection.

More than one second has elapsed since the UE camped on the current serving cell.

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Parameters of R Criteria ( Cont. )

IDLEQHYST2S

Parameter name: Hysteresis 2 for idle mode

Recommended value: Qhyst1s for idle mode

CONNQHYST2S

Parameter name: Hysteresis 2 for connected mode

Recommended value: Qhyst1s for connected mode.

IDLEQHYST2S

Parameter name: Hysteresis 2 for idle mode

Value range: {{0~20},{255}} .

Physical value range: 0~40; step: 2.

Physical unit: dB.

Content: The hysteresis value in idle mode for serving FDD cells in case the qualitymeasurement for cell selection and reselection is set to CPICH Ec/No. It is related to the slowfading feature of the area where the cell is located. The greater the slow fading variance is, thegreater this parameter. It is optional. If it is not configured, [Hysteresis 1] will be adopted as thevalue.

Recommended value: Qhyst1s for idle mode .

Set this parameter through ADD CELLSELRESEL, query it through LST CELLSELRESEL, andmodify it through MOD CELLSELRESEL.

CONNQHYST2S Parameter name: Hysteresis 2 for connected mode

Value range: {{0~20},{255}} .


Physical unit: dB.Content: The hysteresis value in connect mode for serving FDD cells in case the qualitymeasurement for cell selection and reselection is set to CPICH RSCP. It is related to the slowfading feature of the area where the cell is located. The greater the slow fading variance is, thegreater this parameter.

Recommended value: Qhyst1s for connected mode. .

Set this parameter through ADD CELLSELRESEL, query it through LST CELLSELRESEL, andmodify it through MOD CELLSELRESEL.

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TRESELECTIONS

Parameter name: Reselection delay time

Recommended value: 1, namely 1s.

TRESELECTIONS Parameter name: Reselection delay time

Value range: 0~31 .


Physical unit: s.

Content: If the signal quality of a neighboring cell is better than the serving cell duringthe specified time of this parameter, the UE will reselect the neighboring cell. It is usedto avoid ping-pong reselection between different cells. Note: The value 0 correspondsto the default value defined in the protocol.

Recommended value: 1.


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IDLEQOFFSET1SN

Parameter name: IdleQoffset1sn

Recommended value: 0, namely 0dB.

CONNQOFFSET1SN

Parameter name: ConnQoffset1sn


IDLEQOFFSET1SN


Offset of cell CPICH RSCP measurement value in cell selection or reselection when the UE is inidle mode

Value range: -50 to +50 .

Physical value range: -50 to +50; step: 1.Physical unit: dB.

Content: This parameter is used for moving the border of a cell. The larger the value of thisparameter, the lower the probability of neighboring cell selection.


Set this parameter through ADD INTRAFREQNCELL / ADD INTERFREQNCELL, query itthrough LST INTRAFREQNCELL / LST INTERFREQNCELL, and modify it through MODINTRAFREQNCELL / MOD INTERFREQNCELL.

CONNQOFFSET1SN


Offset of cell CPICH RSCP measurement value in cell selection or reselection when the UE is inconnected mode

Value range: -50 to +50 .Physical value range: -50 to +50 ; step: 1.

Physical unit: dB.




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IDLEQOFFSET2SN



CONNQOFFSET2SN



IDLEQOFFSET2SN


Offset of cell CPICH Ec/No measurement value in cell selection or reselection when the UE is inidle mode

Value range: -50 to +50 .

Physical value range: -50 to +50; step: 1.Physical unit: dB.




CONNQOFFSET2SN


Offset of cell CPICH RSCP measurement value in cell selection or reselection when the UE is inconnected mode

Value range: -50 to +50 .Physical value range: -50 to +50 ; step: 1.

Physical unit: dB.




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Location Registration

The location registration includes:

Location update (for non-GPRS)

Route update (for GPRS)

The location registration is used for the PLMN to trace the current status of the UE and toensure that the UE is connected with the network when the UE does not perform any operationfor a long period.

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Periodic Location Registration

Periodic location registration is controlled by a Periodic

Location Update timer (T3212) or a Periodic Routing Area

Update timer (T3312)

Periodic location registration may be used to periodically notify the network of the availability of the UE.

T3212 is for non-GPRS operation

T3312 is for GPRS operation

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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

T3212 Parameter name: Periodical location update timer [6min]

Value range: 0~255.

Physical unit: 6 min.

Content: This parameter indicates the time length of the periodical location update.Periodical location update is implemented by MS through the location updateprocedure. 0: The periodical update procedure is not used. This parameter is valid onlywhen [CN domain ID] is set as CS_DOMAIN.


Set this parameter through ADD CNDOMAIN, query it through LST CNDOMAIN,modify it through MOD CNDOMAIN.

ATT Parameter name: Attach/detach indication

Value range: NOT_ALLOWED, ALLOWED .

Content: NOT_ALLOWED indicates that MS cannot apply the IMSI attach/detach

procedure. ALLOWED indicates that MS can apply the IMSI attach/detach procedure.This parameter is valid only when [CN domain ID] is set as CS_DOMAIN.

Recommended value: ALLOWED.

Set this parameter through ADD CNDOMAIN, query it through LST CNDOMAIN,modify it through MOD CNDOMAIN.

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Contents

1. PLMN Selection




5. Paging Procedure

6. Access Procedure

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Paging Initiation

CN initiated paging

Establish a signaling connection

UTRAN initiated paging

Trigger the cell update procedure

Trigger reading of updated system information

For CN originated paging:In order to request UTRAN connect to UE, CN initiates the paging procedure,transmits paging message to the UTRAN through Iu interface, and UTRAN transmitsthe paging message from CN to UE through the paging procedure on Uu interface,which will make the UE initiate a signaling connection setup process with the CN.

For UTRAN originated paging:When the cell system message is updated: When system messages change, theUTRAN will trigger paging process in order to inform UE in the idle, CELL_PCH or URA_PCH state to carry out the system message update, so that the UE can read theupdated system message.

UE state transition: In order to trigger UE in the CELL_PCH or URA_PCH state tocarry out state transition (for example, transition to the CELL_FACH state), the UTRANwill perform a paging process. Meanwhile, the UE will initiate a cell update or URAupdate process, as a reply to the paging.

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Paging Type 1

If UE is in CELL_PCH,URA_PCH or IDLE state the paging

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

RANAPRANAP

RANAP RANAP

PCCH: PAGING TYPE 1

PAGING

PAGING

PCCH: PAGING TYPE 1

Paging type 1:The message is transmitted in one LA or RA according to LAI or RAI.

After calculating the paging time, the paging message will be transmitted at that time

If UE is in CELL_PCH or URA_PCH state, the UTRAN transmits the paginginformation in PAGING TYPE 1 message to UE. After received paging message, UEperforms a cell update procedure to transit state to CELL_FACH.

As shown in the above figure, the CN initiates paging in a location area (LA), which is coveredby two RNCs. After receiving a paging message, the RNC searches all the cells correspondingto the LAI, and then calculates the paging time, at which it will send the PAGING TYPE 1message to these cells through the PCCH.

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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

RANAPRANAP

PAGING

RRCRRC

DCCH: PAGING TYPE 2

Paging type 2:If UE is in CELL_DCH or CELL_FACH state the paging message will be transmittedon DCCH with paging type 2

The message will be only transmitted in a cell

As shown in the above figure, if the UE is in the CELL_-DCH or CELL_FACH state, theUTRAN will immediately transmit PAGING TYPE 2 message to the paged UE on DCCHchannel.

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Typical Call Flow of UEUE NAS UE AS NS S MS C

paging

AU TH EN TIC AT IO N RE QU ES T

AU TH EN TIC AT IO N RE SP ON SE

RR_SECURITY_CONTROL_REQ

(IK CK)

Security mode control

SETUP

CALL CONFIRM

AL ER T

C ONNE C T

CONNECT ACKNOWLEDGE

RAB setup process

paging

RR_EST_REQ (PAGING RESPONSE)

RR_PAING_IND

INITIAL_DIRECT_TRANSFER

(PAGING RESPONSE)

RANAPRANAP

RRC setup process

Many problems will cause the target UE cannot receive the paging message properlyPower setting of paging channel is unreasonable.

Unreasonable paging strategies will result in paging channel congestion, which cancause paging message loss.

Paging parameter is unreasonable

Equipment fault

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DRX Procedure

UE receives the paging indicator on PICH periodically, that

is the Discontinuous Reception (DRX)

The value for the DRX paging cycle length is determined as

follows: :

DRX Cycle Length (2^K) PBP frames

In idle mode, the UE can monitor the paging in two modes: one is to decode SCCPCH directlyevery 10ms, the other is to decode the PICH periodically. The second one is the DRX, which isDiscontinuous Reception Mechanism.

The paging period formula:

DRX Cycle Length (2^K)*PBP frames

K is the CN domain specific DRX cycle length coefficient, which is broadcasted inSIB1. The typical value is 6.

PBP is paging block period, which is 1 for FDD mode

The paging period should be 640ms if K is 6

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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.

The value of the Paging Occasion is determined as follows:

Paging Occasion (CELL SFN) =

{(IMSI mod M) mod (DRX cycle length div PBP)} * PBP

+ n * DRX cycle length + Frame Offset

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

n =0, 1, 2and the requirement is the calculated CELL SFN must be below itsmaximum value 4096

Frame Offset is 0 for FDD modeM is the number of SCCPCH which carries PCH, and the typical value is 1

The formula cloud be simplified as: SFN = IMSI mod (2^K) + n * (2^K)

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Np NpSFN SFN SFN SFN PI q mod144

144mod512/64/8/18

UE must calculate q to know which PI to monitor in one

frame of PICH

The q value is achieved by the following formula :

Where, PI = (IMSI div 8192) mod N P

SFN is the paging occasion of the UE

As shown in the followed figure, the UE needs to monitor the frames (paging occasions)indicated by the red dots, and then decodes the qth PI of this frame.

0

2^K-1

0 4095

P I P I P I P I

0 1 q NP -1

One DRX cycle

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PICH

Associated S-CCPCH frame

PICH frame containing paging indicator

Time offset between PICH and S-CCPCH

The timing relationship between PICH and S-CCPCH is defined by the above figure, and theinterval is 3 slots duration (2ms, 7680 chips).

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Parameters of DRX

DRXCYCLELENCOEF

Parameter name: DRX cycle length coefficient

Recommended value: 6

PICHMODE

Parameter name: PICH mode

Recommended value: V36.

DRXCYCLELENCOEF Parameter name: DRX cycle length coefficient

Value range: 6~9 .

Content: This parameter is broadcasted on SIB1. This parameter is used when a UE isin idle mode.


Set this parameter through ADD CNDOMAIN, query it through LST CNDOMAIN, andmodify it through MOD CNDOMAIN.

PICHMODE Parameter name: PICH mode

Value range: V18, V36, V72, V144 .

Physical value range: 18, 36, 72, 144 .

Content: Indicating the number of PIs contained in each frame on the PICH.

Recommended value: V36 .

Set this parameter through ADD PICH, query it through LST PICH.

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Parameters of DRX

MACCPAGEREPEAT

Parameter name: Number of page re-TX


MACCPAGEREPEAT Parameter name: Number of page re-TX

Number of retransmissions of paging message

Value range: 0~2 .

Content: If the number of retransmissions of paging message exceeds this parameter value, retransmissions stop.


Set this parameter through SET WFMRCFGDATA, query it through LSTWFMRCFGDATA.

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Contents

1. PLMN Selection




5. Paging Procedure

6. Access Procedure

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Two Working Mode 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

mode from the connected mode

The most important difference between idle mode and connected mode is whether UE hasRRC connection with UTRAN or not.

In idle mode, UE will be identified by IMSI, TMSI or PTMSI and so on.

In connected mode, UE will be identified by URNTI (UTRAN Radio Network TemporaryIdentity), which is the ID of one RRC connection.

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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

This process may happen in the following scenarios: Attach and detach

LA update and RA update

Signaling connection for services

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Random Access Channel

AICH accessslots

10 ms

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

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

PRACHaccess slots

SFN mod 2 = 0 SFN mod 2 = 1

10 ms

Access slot set 1 Access slot set 2

Definition

UE will transmit the preamble at the access time slot

Each 20ms access frame is composed of two 10ms radio frames, which is divided into 15access time slot, and 5120 chips for each slot

The PRACH access slots, AICH access slots and their time offset are showed in the abovefigure

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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

The access class number is stored in the SIM/USIM.

Access class 0~9 are allocated to all the users. And the 10 classes show the same priority.

Access class 11~15 are allocated to specific high priority users as follows. (The enumeration isnot meant as a priority sequence):

Access class 15: PLMN staff

Access class 14: users subscribing to emergency services

Access class 13: public organizations

Access class 12: users subscribing to security services

Access class 11: users responsible for PLMN management

Access Class 10 indicates whether or not network access for Emergency Calls is allowed for UEs with access classes 0 to 9 or without an IMSI. For UEs with access classes 11 to 15,Emergency Calls are not allowed if both "Access class 10" and the relevant Access Class (11to 15) are barred. Otherwise, Emergency Calls are allowed.

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Mapping between AC and ASC

The AC-ASC mapping information is optional and used for

the System Information Block 5 (SIB5) only.

Set the mapping between AC and ASC through ADD PRACHACTOASCMAP, modify itthrough MOD PRACHACTOASCMAP, and remove it through RMV PRACHACTOASCMAP.

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START

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

Increase message part power byp-m based on preamble power

Set physical status to be RACHmessage transmitted Set physical status to be Nackon AICH received

Choose a access slot again

Counter> 0 & Preamblepower-maximum allowed power


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Physical random access procedure1. Derive the available uplink access slots, in the next full access slot set, for the set of available RACH sub-channels within the given ASC. Randomly select one access slotamong the ones previously determined. If there is no access slot available in theselected set, randomly select one uplink access slot corresponding to the set of available RACH sub-channels within the given ASC from the next access slot set. The

random function shall be such that each of the allowed selections is chosen with equalprobability

2. Randomly select a signature from the set of available signatures within the given ASC

3. Set the Preamble Retransmission Counter to Preamble_ Retrans_ Max

4. Set the parameter Commanded Preamble Power to Preamble_Initial_Power

5. Transmit a preamble using the selected uplink access slot, signature, and preambletransmission power

6. If no positive or negative acquisition indicator (AI +1 nor 1) corresponding to theselected signature is detected in the downlink access slot corresponding to theselected uplink access slot:

A: Select the next available access slot in the set of available RACH sub-channels within the given ASC

B: select a signature

C: Increase the Commanded Preamble Power

D: Decrease the Preamble Retransmission Counter by one. If the PreambleRetransmission Counter > 0 then repeat from step 6. Otherwise exit thephysical random access procedure

7. If a negative acquisition indicator corresponding to the selected signature isdetected in the downlink access slot corresponding to the selected uplink access slot,exit the physical random access procedure Signature

8. If a positive acquisition indicator corresponding to the selected signature is detected ,Transmit the random access message three or four uplink access slots after the uplinkaccess slot of the last transmitted preamble

9. Exit the physical random access procedure

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RRC Connection Message

Typical RRC connection messages

RRC_CONNECTION_REQUEST

RRC_CONNECTION_SETUP

RRC_CONNECTION_SETUP_COMPLETE

RRC_CONNECTION_RELEASE

When a UE needs network service, it first sets up RRC connection as follows:The UE sends a RRC CONNECTION REQUEST message from the cell where itcamps to the RNC.

The RNC allocates related resources for the UE and sends an RRC CONNECTION SETUP message to the UE.

The UE sends a RRC CONNECTION SETUP COMPLETE message to the RNC. TheRRC connection setup ends.

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UE Timers and Constants in Idle Mode

T300

Parameter name: Timer 300 [ms]

Recommended value: D2000, namely 2000ms

N300

Parameter name: Constant 300


T300 Parameter name: Timer 300[ms]

Value range: D100, D200, D400, D600, D800, D1000, D1200, D1400, D1600, D1800,D2000, D3000, D4000, D6000, D8000 .

Physical value range: 100, 200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000,3000, 4000, 6000, 8000Physical unit: ms

Content: T300 is started after the UE transmits the RRC CONNECTION REQUESTmessage and stopped after the UE receives the RRC CONNECTION SETUPmessage. RRC CONNECTION REQUEST resents upon the expiry of the timer if V300less than or equal to N300. Otherwise, the UE enters idle mode.

Recommended value: D2000.

Set this parameter through SET IDLEMODETIMER, query it through SETIDLEMODETIMER.

N300

Parameter name: Constant 300Value range: 0~7 .

Content: Maximum number of retransmission of RRC CONNECTION REQUEST .



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UE Timers and Constants in Idle Mode

T312

Parameter name: Timer 312 [s]

Recommended value: 6, namely 6s

N312

Parameter name: Constant 312

Recommended value: D1, namely 1

T312 Parameter name: Timer 312[s]

Value range: 1~15 .

Physical value range: 1~15s

Physical unit: s

Content: T312 is started after the UE starts to establish a DCH and stopped when theUE detects N312 consecutive "in sync" indications from L1. It indicates physicalchannel setup failure upon the expiry of the timer.



N312 Parameter name: Constant 312

Value range: D1, D2, D4, D10, D20, D50, D100, D200, D400, D600, D800, D1000 .

Physical value range: 1, 2, 4, 10, 20, 50, 100, 200, 400, 600, 800, 1000

Content: Maximum number of consecutive "in sync" indications received from L1. .Recommended value: D1.


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RRC Connection Establish ChannelType and Bit Rate

RRCCAUSE

Parameter name: Cause of RRC connection establishment

Recommended value: none

SIGCHTYPE

Parameter name: Channel type for RRC establishment

Recommended value: none

RRCCAUSE Parameter name: Cause of RRC connection establishment

Value range: ORIGCONVCALLEST, ORIGSTREAMCALLEST, ORIGINTERCALLEST,ORIGBKGCALLEST, ORIGSUBSTRAFFCALLEST, TERMCONVCALLEST,TERMSTREAMCALLEST, TERMINTERCALLEST, TERMBKGCALLEST,

EMERGCALLEST, INTERRATCELLRESELEST, INTERRATCELLCHGORDEREST,REGISTEST, DETACHEST, ORIGHIGHPRIORSIGEST, ORIGLOWPRIORSIGEST,CALLREEST, TERMHIGHPRIORSIGEST, TERMLOWPRIORSIGEST,TERMCAUSEUNKNOWN, DEFAULTEST.

Content: The cause of Rrc connection establishment. .

Recommended value: none.

Set this parameter through SET RRCESTCAUSE, query it through LSTRRCESTCAUSE.

SIGCHTYPE Parameter name: Channel type for RRC establishment

Value range: FACH, DCH_3.4K_SIGNALLING, DCH_13.6K_SIGNALLING.Content: FACH indicates that the RRC is established on the common channel.DCH_3.4K_SIGNALLING indicates that the RRC is established on the dedicatedchannel of 3.4 kbit/s. DCH_13.6K_SIGNALLING indicates that the RRC is establishedon the dedicated channel of 13.6 kbit/s. .

Recommended value: none.

Set this parameter through SET RRCESTCAUSE, query it through LSTRRCESTCAUSE.

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