lte signaling flow. content interface and protocol signaling flow of s1 interface signaling flow of...

LTE Signaling Flow

Content

Interface and protocol Signaling Flow of S1 Interface Signaling Flow of X2 Interface Signaling Flow of Basic Service

Network architecture and interfaces

eNB

MME / S-GW MME / S-GW

eNB

eNB

S1

S1

S1 S

1X2

X2X2

E-UTRAN

Functional division of EPC and E-UTRAN

internet

eNB

RB Control

Connection Mobility Cont.

eNB MeasurementConfiguration & Provision

Dynamic Resource Allocation (Scheduler)

PDCP

PHY

MME

Serving Gateway

S1MAC

Inter Cell RRM

Radio Admission Control

RLC

E-UTRAN EPC

RRC

Mobility Anchoring

SAE Bearer Control

Idle State Mobility Handling

NAS Security

Control Plane Protocol

SCTP

L2

L1

IP

L2

L1

IP

SCTP

S1-MME eNodeB MME

S1-AP S1-AP

NAS

MAC

L1

RLC

PDCP

UE

RRC

MAC

L1

RLC

PDCP

RRC

LTE-Uu

NAS Relay

User Plane Protocol

Serving GW PDN GW

S5/S8a

GTP-U GTP-U

UDP/IP UDP/IP

L2

Relay

L2

L1 L1

PDCP

RLC

MAC

L1

IP

Application

UDP/IP

L2

L1

GTP-U

IP

SGi S1-U LTE-Uu

eNodeB

RLC UDP/IP

L2

PDCP GTP-U

Relay

MAC

L1 L1

UE

Signaling and data flow

Signaling flow

eNB

PHY

UE

PHY

MAC

RLC

MAC

MME

RLC

NAS

NAS

RRC RRC

PDCP PDCP

APP

UDP

GTPU

IP

S1AP

SCTP

SGW

IP

UDP

GTPU

IP

SCTP

S1AP

X2AP

Data flow

What is bearer ?

An EPS bearer uniquely identifies traffic flows that receive a common QoS treatment between a UE and a PDN GW

EPS Bearer Service Architecture

P-GWS-GW PeerEntity

UE eNB

EPS Bearer

Radio Bearer S1 Bearer

End-to-end Service

External Bearer

Radio S5/S8

Internet

S1

E-UTRAN EPC

Gi

E-RAB S5/S8 Bearer

Concept of Connection

Content

Interface and protocol Signaling Flow of S1 Interface Signaling Flow of X2 Interface Signaling Flow of Basic Service

S1 Setup

eNB MME

S1 SETUP REQUEST

S1 SETUP RESPONSE

eNB Configuration Update

eNB MME

ENB CONFIGURATION UPDATE ACKNOWLEDGE

ENB CONFIGURATION UPDATE

MME Configuration Update

MME eNB

MME CONFIGURATION UPDATE

MME CONFIGURATION UPDATE ACKNOWLEDGE

Content

Interface and protocol Signaling Flow of S1 Interface Signaling Flow of X2 Interface Signaling Flow of Basic Service

X2 Setup

Source eNB Neighbour eNB

X2 SETUP REQUEST

X2 SETUP RESPONSE

eNB Configuration Update

Neighbour eNBSource eNB

ENB CONFIGURTION UPDATE

ENB CONFIGURATION UPDATE ACKNOWLEDGE

Load Indication

Neighbour eNBSource eNB

LOAD INFORMATION

Resource Status Request

Neighbour eNB

Source eNB

RESOURCE STATUS REQUEST

RESOURCE STATUS RESPONSE

RESOURCE STATUS UPDATE

Resource Status Reporting Initiation

Neighbour eNB

Source eNB

RESOURCE STATUS REQUEST

RESOURCE STATUS RESPONSE

Content

Interface and protocol Signaling Flow of S1 Interface Signaling Flow of X2 Interface Signaling Flow of Basic Service

PLMN selection and cell selection

System Information Broadcast

eNBUE

Master Information Block

System Information Block Type1

System Information

Random access procedureUE eNB

Random Access Preamble1

Random Access Response 2

Scheduled Transmission3

Contention Resolution 4

L2/ L3 indicates "Random Access Preamble" transmission

L1 transmits "Random Access Preamble"

L2/ L3 procedure

L1 procedure

ACK ("Random Access Response" reception)

DTX reception (No "Random Access Response" reception)

L2/ L3 receives indication from L1

L2/ L3 receives indication from L1

L2/ L3 indicates "RRC Connection Request" transmission

L2/ L3 indicates "Random Access Preamble" transmission

UE AttacheNB MMEUE

Identity/Authentication/Security

INITIAL CONTEXT SETUP REQUEST（include Attach Accept，Activate default EPS bearer context

request message）

MSG1

MSG2-Random Access Response

RRC Connection Request

RRC Connection Setup

RRC Connection Setup Complete(include Attach request message) INITIAL UE MESSAGE（include Attach

request message）

UE Capability Enquiry

UE CAPABILITY INFO INDICATION

UE Capability Information

Security Mode Command

Security Mode Complete

RRCConnectionReconfiguration(include Attach accept，Activate default EPS bearer context

request message)

RRC Connection Reconfiguration Complete

ULInformationTransfer(include Attach Complete, Activate default EPS bearer context accept)

INITIAL CONTEXT SETUP RESPONSE

UPLINK NAS TRANSPORT(include Attach Complete, Activate default EPS bearer context accept)

UE Detach( power off in idle)eNB MMEUE

MSG1

MSG2-Random Access Response

RRC Connection Request

RRC Connection Setup

RRC Connection Setup Complete(include Detach request message)

INITIAL UE MESSAGE（include Detach request message）

UE CONTEXT RELEASE COMMAND

UE CONTEXT RELEASE COMPLETE

UE Detach( power off in connected)

eNB MMEUE

ULInformationTransfer（include Detach request message）

DLInformationTransfer(include Detach accept message)

UPLINK NAS TRANSPORT（include Detach request message）

DOWNLINK NAS TRANSPORT(include Detach accept message)

UE CONTEXT RELEASE COMMAND

UE CONTEXT RELEASE COMPLETE

UE Detach(no power off in idle)eNB MMEUE

RRC Connection Release

UE CONTEXT RELEASE COMPLETE

UE CONTEXT RELEASE COMMAND

DLInformationTransfer(include

Detach accept message)

DOWNLINK NAS TRANSPORT(include Detach accept message)

INITIAL UE MESSAGE（include Detach request

message）

RRC Connection Setup Complete(include Detach request message)

RRC Connection Setup

RRC Connection Request

MSG2-Random Access Response

MSG1

UE Detach(no power off in connected)eNB MMEUE

ULInformationTransfer（include

Detach request message）

DLInformationTransfer(include Detach

accept message)

UPLINK NAS TRANSPORT（include

Detach request message）

DOWNLINK NAS TRANSPORT(include Detach accept message)

UE CONTEXT RELEASE COMMAND

RRC Connection Release

UE CONTEXT RELEASE COMPLETE

Paging(system information changed)

MMEUE

Paging

Paging(MME trigger)

MMEUE

Paging

eNB

PAGING

Service Request(UE trigger)eNB MMEUE

INITIAL CONTEXT SETUP RESPONSE

RRC Connection Reconfiguration Complete

RRC Connection Reconfiguration

Security Mode Complete

Security Mode Command

UE Capability Information

UE Capability Enquiry

UE CAPABILITY INFO INDICATION

INITIAL CONTEXT SETUP REQUEST

Identity/Authentication/Security

INITIAL UE MESSAGE（include Service

request message）

RRC Connection Setup Complete( include Service request message)

RRC Connection Setup

RRC Connection Request

MSG2-Random Access Response

MSG1

TAU in Idle(no active identifier)

UE EPCeNB

1 . RA Preamble

7 . Authentication Security/

3 . RRC Connection Request

2 . RA Response

4 . RRC Connection Setup

5 . RRC Connection Setup Complete ( include TAU request )

13. UE CONTEXT RELEASE COMMAND

6 . Initial UE message (Include TAU request)

9 . DOWNLINK NAS TRANSPORT ( include TAU Accept)

10. DL Information Transfer ( include TAU Accept)

11. UL Information Transfer (include TAU Complete)

12. UPLINK NAS TRANSPORT (include TAU Complete)

Return to IDLE mode

15. UE CONTEXT RELEASE COMPLETE

14. RRC Connection Release

8 . Update UE context information between MME

In idle mode, UE into TAI is not within TAI list

TAU in Idle(setup active identifier)

UE EPCeNB

1. RA Preamble

First Downlink Data

7. Authentication/Security

3. RRC Connection Request

2. RA Response

4. RRCConnectionSetup

5. RRC Connection Setup Complete (include TAU Request )

First Uplink Data

6. Initial UE message (include TAU request)

9. Initial context setup request (include TAU Accept)

15. RRC Connection Reconfiguration (include TAU Accept)

16. RRC Connection Reconfiguration Complete 17. Initial context setup

response

19. UPLINK NAS TRANSPORT (include TAU Complete)

10. UE Capability Enquiry

11. UE Capability Information

13. SecurityModeCommand

14. SecurityModeComplete

12. UE Capability Info Indication

18. UL Information Transfer (include TAU Complete)

In idle mode, UE into TAI is not within TAI list

8. Update UE context

information between MME

20. Update RAB

TAU in Connected UE EPCeNB

In connected mode, UE into TAI is not

within TAI list

3. Update UE Context between MME

1. ULInformationTransfer(include TAU request message)

4. DOWNLINK NAS TRANSPORT(include TAU Accept message)

5. DLInformationTransfer（include TAU Accept message）

6. ULInformationTransfer（include TAU Complete message）

7. UPLINK NAS TRANSPORT

（include TAU Complete message）

2. UPLINK NAS TRANSPORT

（include TAU request message）

E-RAB Setup

E-RAB Release

RRC Connection Re-establishment

UE Handover between one eNB’s cellseNB

UE Handover between the different eNB’s cells(through X2 interface)

UE Handover between the different eNB’s cells(through S1 interface)