3 UMTS Signaling Flow-62

62
UMTS Signaling Flow ZTE University

Transcript of 3 UMTS Signaling Flow-62

Page 1: 3 UMTS Signaling Flow-62

UMTS Signaling Flow

ZTE University

Page 2: 3 UMTS Signaling Flow-62

Content

UE State transition

Signaling flow

Page 3: 3 UMTS Signaling Flow-62

Classification of Flows

In terms of protocol stack, signaling flows can be

access layer signaling flows or non-access layer

signaling flows.

In terms of network composition, signaling flows

can be categorized as circuit-switched or packet-

switched.

Access layer and non-access layer signaling flows

are actually so named from the perspective of

protocol stack.

Page 4: 3 UMTS Signaling Flow-62

Classification of Flows

The flows at the access layer include PLMN

selection, cell selection, and radio resource

management flows.

The radio resource management flows are the

flows at the RRC layer, including the RRC

connection setup flow, flow of the signaling setup

between UEs and CNs, RAB setup flow, call

release flow, handover flow, and SRNS redirection

flow.

Page 5: 3 UMTS Signaling Flow-62

UE Working Modes

There are two basic working modes:

Idle

UE stands by without any service. There’s no connection

between UE and UTRAN.

Connected

UE transferred to the connected mode after accomplishing RRC

Connection Setup.

UE has 4 states under the connected mode:Cell-DCH, Cell-

FACH, Cell-PCH, URA-PCH

Page 6: 3 UMTS Signaling Flow-62

UE State

Page 7: 3 UMTS Signaling Flow-62

UE States Under the Connected Mode

Cell-DCH

UE is activated, and in service using its dedicated

channels.

There are dedicated channels in both uplink and

downlink.

UTRAN knows exactly which cell the UE is in.

Cell-FACH

UE is activated, but without too much date to transmit,

so there’s no need to assign dedicated channels to it.

Downlink data transmitted in FACH, while uplink in

RACH.

UTRAN knows exactly which cell the UE is in.

Page 8: 3 UMTS Signaling Flow-62

UE States Under the Connected Mode

Cell-PCH

There is no data transmitted in both uplink and downlink.

UE needs to listen to PICH for paging information.

UE works in discrete receiving, which saves the power effectively.

UTRAN knows exactly which cell the UE is in.

UE needs to do cell update procedure when it passes cells.

URA-PCH

There is no data transmitted in both uplink and downlink.

UE needs to listen to PICH for paging information and receive

discretely.

UTRAN only knows which URA (UTRAN Registration Area) UE

exists.

UE updates its location information only when its URA changes,

which further reduces the signaling saves resource.

Page 9: 3 UMTS Signaling Flow-62

RRC State Transition (I)

After RRC Connection Setup, UE will

transit to CELL_FACH or CELL_DCH.

CN indicates UE using dedicated

channel (CELL_DCH) or common

channel (CELL_FACH) according to

the service request.

If there is no service right now, UE

will be indicated into PCH mode or

release RRC connection back to

IDLE mode.

URA_PCH

CELL_DCH CELL_FACH

CELL_PCH

IDLE

DEAD

IDLE

DEAD

CELL_DCH CELL_FACH

IDLE

Sketch of RRC State Transition

—— Transit from IDLE Mode

Page 10: 3 UMTS Signaling Flow-62

URA_PCH

CELL_DCH

CELL_PCH

IDLE

DEAD

IDLE

DEAD

CELL_FACH

IDLE

RRC State Transition (II)

UE do not occupy dedicated

channels In the mode of

CELL_FACH.

UE receives downlink data through

FACH(S-CCPCH).

UE transmits uplink data through

RACH(PRACH).

——Transit from CELL_FACH Mode

Sketch of RRC State Transition

Page 11: 3 UMTS Signaling Flow-62

URA_PCH

CELL_DCH CELL_FACH

CELL_PCH

IDLE

DEAD

IDLE

DEAD

CELL_DCH

IDLE

URA_PCH CELL_PCH

CELL_DCH

RRC State Transition (III)

UE transceives uplink and downlink

data through dedicated channels

(DPDCHs and DPCCHs).

During the time when there is no data

transmitted, CN may indicate UE’s

transiting to URA_PCH or CELL_PCH.

——Transit from CELL_DCH Mode

Sketch of RRC State Transition

Page 12: 3 UMTS Signaling Flow-62

URA_PCH

CELL_DCH CELL_FACH

CELL_PCH

IDLE

DEAD

IDLE

DEAD

CELL_DCH

IDLE

CELL_DCH

URA_PCH CELL_PCH

CELL_FACH

——CELL_PCH和URA_PCH

RRC State Transition (IV)

UE has no activated uplink.

Paging Information makes UE back to

CELL_FACH or CELL_DCH mode.

In CELL_PCH, UE should transit to

CELL_FACH first to finish cell updating,

and go back if no service request.

In URA_PCH, if URA changes, UE also

transits to CELL_FACH to finish cell

updating first before it goes back to

URA_PCH.

System resource can be saved in these

two modes.Sketch of RRC State Transition

Page 13: 3 UMTS Signaling Flow-62

Content

UE State transition

Signaling flow

Page 14: 3 UMTS Signaling Flow-62

Basic Conception (1)

RRC (Radio Resource Control)

provides information transfer service to the NAS (Non

Access Stratum).

responsible for controlling the configuration of UMTS

radio interface Layers 1 and 2.

RRC Connection

A point to point bi directional connection between the

RRC (Radio Resource Control) entities on the UE (User

Equipment) and UTRAN (UMTS Terrestrial Radio

Access Network).

The UE requires an RRC connection to access the

services of the UMTS network.

Page 15: 3 UMTS Signaling Flow-62

Basic Conception (2)

RAB -Radio Access Bearer

Identify the service the AS (Access Stratum) provides to

the NAS (Non Access Stratum) for transfer of user data

between the UE (User Equipment) and the CN (Core

Network).

RB -Radio Bearer

The service provided by the Layer 2 for the transfer of

user data between UE (User Equipment) and UTRAN

(UMTS Terrestrial Radio Access Network).

Page 16: 3 UMTS Signaling Flow-62

Basic Conception (3)

RL (Radio Link)

RL is a logical association between single UE (User

Equipment) and a single UTRAN (UMTS Terrestrial

Radio Access Network) access point.

Its physical realization comprises one or more radio

bearer transmissions.

It is possible for a UMTS mobile to have many radio

links established, when this occurs the mobile is said to

be in a soft handover.

Page 17: 3 UMTS Signaling Flow-62

Sketch of the basic conceptions

Page 18: 3 UMTS Signaling Flow-62

UE Calling Flow

Power on

Cell selection

Location

Update

Idle Mode

RRC

Establish

NAS

Establish

Hand OverCell/

URA update

Channel

reconfiguration

RB/RAB

Modification

RAB

Establish

RRC

Release

Call

Initiate

④ ⑤ ⑥

Page 19: 3 UMTS Signaling Flow-62

UE in Idle Mode

Page 20: 3 UMTS Signaling Flow-62

What Information needed for UE?

(1) Strongest cell

(2) Slot boundary

(3)Frame

boundary

(4) Primary SC

(5) Information in broadcasts

channel

Page 21: 3 UMTS Signaling Flow-62

1st Step: Cell Selection and Slot Synchronization

Page 22: 3 UMTS Signaling Flow-62

DL Scrambling Code Rule

218

-1 DL Scrambling Codes in total

(0..262142)

The

left

8192

Scrambling

codes

are

used

for

compression

mode

The

left

8192

Scrambling

codes

are

used

for

compression

mode

#511 Scrambling Code

Group

8176

8177

8191

8176:P-SC

8177:S-SC

8191:S-SC

#510 Scrambling Code

Group

8160

8161

8175

8160:主扰码

8161:辅扰码

8175:辅扰码

#504 Scrambling Code

Group

8064

8065

8079

8064:主扰码

8065:辅扰码

8079:辅扰码

#7 Scrambling Code

Group

112

113

127

8176:P-SC

8177:S-SC

8191:S-SC

#1 Scrambling Code

Group

1

6

1

7

3

1

16:P-SC

17:S-SC

31:S-SC

#0 Scrambling Code

Group

0

1

1

5

0:P-SC

1:S-SC

15:S-SC

#0 Scrambling Code Cluster

#63 Scrambling Code Cluster

… …

Page 23: 3 UMTS Signaling Flow-62

2rd Step: Frame synchronization and Scrambling code-group

Page 24: 3 UMTS Signaling Flow-62

Scrambling-code identification

CPICH is predefine

sequence

Spreading Factor is 256

(Cch,256,0)

Scrambling by P-

scrambling code

UE identified through

symbol-by-symbol

correlation over the

primary P-CPICH with all

the scrambling codes

within the code group.

Page 25: 3 UMTS Signaling Flow-62

Obtain broadcast information in P-CCPCH

P-CCPCH contain the

current SFN and system

broadcast information

P-CCPCH SF=256

(Cch,256,1)

P-CCPCH scrambling by

primary scrambling code

UE can use obtained

primary scrambling code

to descrambling the P-

CCPCH and obtain the

BCH information

Page 26: 3 UMTS Signaling Flow-62

UE Calling Flow

Power on

Cell selection

Location

Update

Idle Mode

RRC

Establish

NAS

Establish

Hand OverCell/

URA update

Channel

reconfiguration

RB/RAB

Modification

RAB

Establish

RRC

Release

Call

Initiate

④ ⑤ ⑥

Page 27: 3 UMTS Signaling Flow-62

UE Initiate Random Access

Page 28: 3 UMTS Signaling Flow-62

Establish Dedicated RRC Connection

UE Node B SRNC

2.Allocate RNTI

L1 and L2 Parameters

1. RRC Connection Request

5. ALCAP Establish and Synchronization

3. NBAP RL Setup Request

7. RRC Connection Setup Complete

6. RRC Connection Setup

4. NBAP RL Setup Response

Page 29: 3 UMTS Signaling Flow-62

RRC Connection Rejection

If the RNC determines that the RRC connection cannot be

established (for example, due to insufficient resources),

the RNC directly sends the UE an RRC CONNECTION

REJECT message which contains the reason for the

rejection of the RRC connection.

Page 30: 3 UMTS Signaling Flow-62

1. RRC Initial Direct Transfer

Establish Signaling Link with CN

UE SRNC CN

3. SCCP CC(Success)

2. RANAP Initial UE Message

SCCP Connect Request

3. SCCP CJ(Failure)

4. RRC Direct Transfer

5. RRC Direct Transfer

Page 31: 3 UMTS Signaling Flow-62

1.1 Send Authentication Info

4. Security Mode Command

5. Security Mode Complete

6. Security Mode Complete

3.Security Mode Control

Authentication and Security Mode

UE RNS MSC Server/VLR

1. Authentication Request

2. Authentication Response

HLR

2.1 Send Authentication Info Ack

Page 32: 3 UMTS Signaling Flow-62

MAP Cancel Location ACK

MAP_Cancel_Location

Location Update Request

MAP Update Location

MAP_Insert _Subscriber_Data

MAP_Update _Location_ACKLocation Update

Confirm ACK

TMSI_Allocation_Complete

UE RNS MSC Server/VLR PVLR HLR

MAP_Insert _Subscriber_Data_ACK

Release CN

Signaling ConnectionRelease RB

CS Location Update Process

Establish RRC Connection

Establish CN Signaling Connection

Authentication and Security Mode

Page 33: 3 UMTS Signaling Flow-62

UE Calling Flow

Power on

Cell selection

RRC

Establish

NAS

Establish

Hand OverCell/

URA update

Channel

reconfiguration

RB/RAB

Modification

RAB

Establish

RRC

Release

Call

Initiate

④ ⑤ ⑥

Location

Update

Idle Mode

Page 34: 3 UMTS Signaling Flow-62

UE Work Mode Transforming

CELL_DCH CELL_FACH

CELL_PCHURA_PCH

IDLE

DEAD

RRC connection

All the Status exist in UTRAN and UE, and transparent for CN

Network

Selection (PLMN)

Cell Camping

Probe paging

channel

Cell

Reselection

High level

Signaling

Triger (CN)

Dedicated

Channel

RB Transport

Service

Page 35: 3 UMTS Signaling Flow-62

UE Calling Flow

Power on

Cell selection

Location

Update

Idle Mode

RRC

Establish

NAS

Establish

Hand OverCell/

URA update

Channel

reconfiguration

RB/RAB

Modification

RAB

Establish

RRC

Release

Call

Initiate

④ ⑤ ⑥

Page 36: 3 UMTS Signaling Flow-62

Procedure of Call Initiate

Page 37: 3 UMTS Signaling Flow-62

Call Setup Flow

CN initiates a paging message to RNC.

RNC judges the paging message from the CN and then sends a

paging message to the corresponding UE.

If no RRC connection is available, UE will send a RRC connection

setup request message (RRC Connection Request) to RNC.

RNC determines to set up a RRC connection according to the service

request and system resource occupation then sends a RRC

connection setup message (RRC Connection Setup) to UE.

After signaling connection setup, the higher layer of UE (NAS) sends a

service request message to CN through a directly transfer message.

CN sends a RAB assignment message (RAB Assignment Request) to

the RNC to allocate resource for UE’s request.

Page 38: 3 UMTS Signaling Flow-62

3. NBAP RL Reconfigure Prepare

RAB Establish Flow

UE Node B SRNC

1. RANAP RAB Assignment Request

4. NBAP RL Reconfigure Ready

MSC

2. ALCAP Establish and Synchronization

5. ALCAP Establish and Synchronization

6. NBAP RL Reconfigure Commit

7. RRC RB Setup

8. RRC RB Setup Complete

9. RANAP RAB Assignment Response

Page 39: 3 UMTS Signaling Flow-62

8. ISUP IAM

UE Initiate Call

UE RNS MSC Called MSC

1. RRC establish

6. RRC DT(Call Proceeding)

3. RRC DT(CM Service Request)

2. CN signaling establish

4. Authentication and Security

5. RRC DT(Setup)

7. RAB establish

10. ISUP ACM11. RRC DT(Alert)

12. ISUP ANM13. RRC DT(Connect)

14. RRC DT(Connect ACK)

15. Conversation

9. CN bearer establish

Page 40: 3 UMTS Signaling Flow-62

UE Receiving Call

1. ISUP IAM

UE RNS Called MSC Calling MSC

4. RRC establish

8. RRC DT(Setup)

6. RRC DT(Paging Response)

5. CN signalling establish

7. Authentication and Security

9. RRC DT(Call Confirm)

10. RAB establish

2. Paging

3. Paging

11. RRC DT(Alerting)12. ISUP ACM

13. RRC DT(Connected)14. ISUP ANM

16. Conversation

15. RRC DT(Connect ACK)

Page 41: 3 UMTS Signaling Flow-62

UE Calling Flow

Power on

Cell selection

Location

Update

Idle Mode

RRC

Establish

NAS

Establish

Hand OverCell/

URA update

Channel

reconfiguration

RB/RAB

Modification

RAB

Establish

RRC

Release

Call

Initiate

④ ⑤ ⑥

Page 42: 3 UMTS Signaling Flow-62

Handover Category

Intra-system handover

Softer handover, soft handover, hard handover

Depending on the Ec/No of CPICH

Inter-system handover

Between FDD and TDD

Handover with different system

2G/3G handover

Compression mode

Page 43: 3 UMTS Signaling Flow-62

Softer/Soft Handover Gain and Costs

Softer/Soft Handover Gain:

The optimal fast close loop power control (MS always keep connection with the

most powerful cell)

Seamless handover, without RB interruption

When MS moves to the edge of the cell, and could not obtain enough signal power,

it can obtain Macro diversity from multiple cells

The UL signaling quality can be improved through obtaining Macro diversity when

Node B (Softer HO) and RNC (Soft HO) combine the receiving signal and lower the

required Transport power of UE.

Softer/Soft Handover Costs:

Additional Rake receiver channel on Node B

Additional DL channelization code

Additional DL power

Additional Rake receiver channel on MS

Additional transport link between Node B and RNC (RNC internal Soft Handover)

Additional transport link between S-RNC and D-RNC (Soft handover between

RNCs)

Page 44: 3 UMTS Signaling Flow-62

Soft Handover Flow

UENodeB(DRNS)

DRNCNodeB(SRNS)

Measurementreport

RL creation requestRL setup request

Active set update command

SRNC

RL setup response RL setup response

Active set update completion

RL Deletion request

RL Deletion response

A

B

Page 45: 3 UMTS Signaling Flow-62

Hard Handover Flow

UETargetNodeB

SRNCOriginalNodeB

Measurement report

RL setup request

Reconfiguration command

RL setup response

Reconfiguration completion

RL deletion request

RL deletion response

Page 46: 3 UMTS Signaling Flow-62

UE Calling Flow

Power on

Cell selection

Location

Update

Idle Mode

RRC

Establish

NAS

Establish

Hand OverCell/

URA update

Channel

reconfiguration

RB/RAB

Modification

RAB

Establish

RRC

Release

Call

Initiate

④ ⑤ ⑥

Page 47: 3 UMTS Signaling Flow-62

Forward Hard Handover

UE Source RNC CNTarget RNC

2. Uplink Signalling

Transfer Indication

[new C-RNTI, D-RNTI,

UL message]

1.CCCH: Cell Update

[Cell Update Cause,U-RNTI,

Measured results on PRACH]

RRC-relayRRC

RNSAP RNSAP

4.DCCH: Cell Update Confirm

[S-RNTI, SRNC-ID, new S-RNTI,

new SRNC-ID, new C-RNTI]

RRCRRC

5.DCCH: RNTI Reallocation Complete

RRCRRC

3. Serving RNC Relocation

Page 48: 3 UMTS Signaling Flow-62

SRNC Relocation

2. Relocation RequiredRANAP RANAP

RANAP RANAP

6. Relocation

Request Ack.

RANAP RANAP1. Relocation Required

UE Node B RNC

Source

RNC

Target

MSC/SGSN SGSN/MSC

RANAP RANAP

4. Relocation Request

RANAP RANAP3. Relocation Request

RANAP RANAP7. Relocation Request Ack.

RANAP RANAP9. Relocation Command

RANAP RANAP8. Relocation Command

RANAP RANAP

12. Relocation

Complete

RANAP RANAP11. Relocation Complete

RNSAP RNSAP

10. Relocation

Commit

RANAP13. Iu Release Command

RANAP

RANAP14. Iu Release Command

RANAP

5. ALCAP Iu Data

Transport Bearer Setup

15. ALCAP Iu Data Transport Bearer Relelase

RANAP16. Iu Release Complete

RANAP

RANAP17. Iu Release Complete

RANAP

Page 49: 3 UMTS Signaling Flow-62

UE Calling Flow

Power on

Cell selection

Location

Update

Idle Mode

RRC

Establish

NAS

Establish

Hand OverCell/

URA update

Channel

reconfiguration

RB/RAB

Modification

RAB

Establish

RRC

Release

Call

Initiate

④ ⑤ ⑥

Page 50: 3 UMTS Signaling Flow-62

DCH-DCH Transport Channel ReconfigurationUE Node B

Drift RNS

Node B

Serving RNS

Drift

RNC

Serving

RNC

CN

RNSAP RNSAP

5. Radio Link Reconfiguration

Ready

RRCRRC13. DCCH : Transport Channel Reconfiguration Complete

NBAPNBAP6. Radio Link Reconfiguration Ready

NBAPNBAP4. Radio Link Reconfiguration Ready

NBAPNBAP11. Radio Link Reconfiguration Commit

RNSAP RNSAP

9. Radio Link Reconfiguration

Commit

NBAPNBAP10. Radio Link Reconfiguration Commit

RRCRRC12. DCCH : Transport Channel Reconfiguration

8. ALCAP Iub Data Transport Bearer Set-up

RNSAP RNSAP

1. Radio Link Reconfiguration

Prepare

NBAPNBAP2. Radio Link Reconfiguration Prepare

NBAPNBAP3. Radio Link Reconfiguration Prepare

ALCAP Iur Bearer Set-up7. ALCAP Iub Data Transport Bearer Set-up

15. ALCAP Iub Data Transport Bearer Release

ALCAP Iur Bearer Release14. ALCAP Iub Data Transport Bearer Release

Page 51: 3 UMTS Signaling Flow-62

Cell-FACH to Cell-DCH State TransformUE Node B

Drift RNS

Drift

RNC

Serving

RNC

6. NodeB-SRNC Data Transport Bearer Sync.

RNSAP RNSAP

1. Radio Link Setup

Request

Start TX

description

NBAP NBAP

2. Radio Link Setup

Request

RNSAP RNSAP

4. Radio Link Setup

Response

NBAP NBAP

3. Radio Link Setup

Response

Start RX

description

Decision to switch to

Cell_DCH state

RRCRRC

8. DCCH : Physical Channel Reconfiguration Complete

RRCRRC

7. DCCH : Physical Channel Reconfiguration

ALCAP Iur Bearer Setup5. ALCAP Iub Bearer Setup

RNSAP RNSAP

9. Common Transp. Channel

Resources Release Request

Page 52: 3 UMTS Signaling Flow-62

Cell-DCH to Cell-FACH Transform UE Node B DRNC SRNC

RNSAP 6. Radio Link Deletion Request

RNSAP

RNSAP RNSAP 9. Radio Link Deletion Response

3. ALCAP Iur bearer setup

(if needed)

RRC 4. DCCH : Physical Channel Reconfiguration

RRC

决定切换到

Cell_FACH 状态

state

RRC 5. DCCH : Physical Channel Reconfiguration Complete

RRC

NBAP 7. Radio Link Deletion Request

NBAP

NBAP NBAP 8. Radio Link Deletion Response

ALCAP Iur bearer release

RNSAP

1. Common Transp. Channel Resources

Initialization Request

RNSAP

RNSAP RNSAP

2. Common Transp. Channel Resources

Initialization Response

10. ALCAP Iub bearer release

[C-RNTI, Primary CPICH Info [FDD],

optional: Secondary CCPCH Info, PRACH Info]

Page 53: 3 UMTS Signaling Flow-62

UE Calling Flow

Power on

Cell selection

Location

Update

Idle Mode

RRC

Establish

NAS

Establish

Hand OverCell/

URA update

Channel

reconfiguration

RB/RAB

Modification

RAB

Establish

RRC

Release

Call

Initiate

④ ⑤ ⑥

Page 54: 3 UMTS Signaling Flow-62

RAB Release Flow

Page 55: 3 UMTS Signaling Flow-62

RRC Connection Release

UE NodeB SRNC

1. RRC£ ºRRC CONNECTION RELEASE

2. RRC£ ºRRC CONNECTION RELEASE COMPLETE

3. RL DELETION

4. RL DELETION RESPONSE

5. ALCAPÊ Í· Å5. ALCAP Release

Page 56: 3 UMTS Signaling Flow-62

Call setup flow (1)

Page 57: 3 UMTS Signaling Flow-62

Call setup flow (2)

Page 58: 3 UMTS Signaling Flow-62

Call setup flow (3)

Page 59: 3 UMTS Signaling Flow-62

Call setup flow (4)

Page 60: 3 UMTS Signaling Flow-62

Call setup flow (5)

Page 61: 3 UMTS Signaling Flow-62

Call setup flow (6)

Page 62: 3 UMTS Signaling Flow-62