3GPP2 WRKSP-20120315-xxxr0 2012 Workshop Planning Title: Interworking with LTE Source: Mike Dolan, Tony Lee Abstract: Draft Presentation on Interworking

3GPP2 WRKSP-20120315-xxxr0

2012 Workshop Planning

Title: Interworking with LTE

Source: Mike Dolan, Tony Lee

Abstract:

Draft Presentation on Interworking with LTE

Recommendation:

Review and Approve.

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COPYRIGHT © 2012 3GPP2. ALL RIGHTS RESERVED.

Interworking with LTEOutline

At the Core and RAN Level

LTE eHPRD How eHRPD connects to the same Enhanced Packet Core (EPC)

Handoff

LTE cdma2000® 1x CSFB, eCSFB

SMS

At the Radio Level

LTE eHPRD xxx

LTE cdma2000® 1x xxx


LTE eHPRD How eHRPD connects to the same Enhanced Packet Core (EPC)

PDN Gateway

Serving Gateway

MME

eNodeB

HSS/AAA

Home Agent

Internet

HSGWPDSN

eAN/ePCF

AN/PCF

PCRF

3GPP2 AAA

Signaling

Data

UE


Non-Optimized Handoff from LTE to eHRPD

PDN Gateway

Serving Gateway

MME

eNodeB

HSS/AAA Internet

HSGW

eAN/ePCF

PCRF

Signaling

Data

UE


Optimized Handoff from LTE to eHRPDStep 1 – Establish context on eHRPD via tunneled signaling

PDN Gateway

Serving Gateway

MME

eNodeB

HSS/AAA Internet

HSGW

eAN/ePCF

PCRF

Signaling

Data

UE

S101


Optimized Handoff from LTE to eHRPDStep 2 – UE moves to eHRPD, bearers are moved

PDN Gateway

Serving Gateway

MME

eNodeB

HSS/AAA Internet

HSGW

eAN/ePCF

PCRF

Signaling

Data

UE

S101


Comparison of Optimized vs. Non-Optimized

Optimized handoff takes less than 300 msec.

Non-optimized handoff can take as much as 5-7 seconds.

Optimized handoff requires in addition to what non-optimized needs:

S101 tunneling

Upgrades on the UE, MME, eAN/ePCF, HSGW


Circuit Switched Fall Back (CSFB)Core network and RAN

Uses tunneled signaling to the UE across the S102 interface between the IWS and MME. This supports:

CSFB, enhanced CSFB (eCSFB)

SMS


CSFB

MME

eNodeB

IWS

1x BS

Signaling

Data

UE

MSC

S102

• Page sent to IWS.

• IWS sends page to UE via MME and eNodeB using S102.

• UE moves to 1x.

• UE sends a normal page response on the 1x access channel.

• Call proceeds.


eCSFB

MME

eNodeB

IWS

1x BS

Signaling

Data

UE

MSC

S102

• Page sent to IWS.

• IWS sends page to UE via MME and eNodeB using S102.

• UE sends a page response via the eNodeB and MME.

• IWS sends a handoff command (UHDM) to the UE via S102, and sets up the traffic channel on 1x in preparation for the UE.

• UE does a handoff to the 1x traffic channel.

• 1x call proceeds.


Comparison of CSFB to eCSFB

CSFB requires extra time on 1x due to hashing and other procedures.

For eCSFB, the traffic channel is prepared and waiting for the UE to arrive.

Some issues at the radio level will be discussed later, when the radio level is covered.


SMSBoth mobile originated and mobile terminated are supported.

MME

eNodeB

IWS

1x BS

Signaling

Data

UE

MSC

S102MT-SMS

• SMS are sent via S102 to the UE

• UE does not leave LTE.

MO-SMS

• SMS are sent via S102 from the UE

• UE does not leave LTE.

13

COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED.

Interworking with LTERadio Level LTE eHPRD (optimized handoff)Requires S-101

14


HRPD-LTE Dual Mode Protocol Structure

LTE-HRPD multi-mode AT

LTE-eNB HRPD RNC

ConnectionLayer

Protocols

LTE-PHY

LTE-MAC

LTE-RRC

LTE-PHY

LTE-MAC

LTE-RRC

HRPD-Security

HRPD-MAC

HRPD-PHY

LTE-MME

LTE-S1

LTE-S1

LTE-S101

LTE-S101

HRPD-StreamProtocol

HRPD-SignalingNetworkProtocol

Radio Link

Protocol

HRPD-Signaling

Link Protocol

HRPD-StreamProtocol

HRPD-SignalingNetworkProtocol

Radio Link

Protocol

HRPD-Signaling

Link Protocol

Connection Layer Protocols

HRPD-Security

HRPD-MAC

HRPD-PHY

S1-AP S101

LTE-Uu

15


• New protocols to support LTE to eHRPD

Default Signaling Adaptation Protocol (no counterpart in HRPD)

InterRAT Initialization Protocol

InterRAT Idle State Protocol

InterRAT Route Update Protocol

InterRAT Overhead Message Protocol

InterRAT Signaling Adaptation Protocol (no counterpart in HRPD)

• Additional new protocols to support LTE to eHRPD with air interface that support C.S0024-B

InterRAT Quick Idle State Protocol

Subtype 1 based InterRAT Route Update Protocol

InterRAT Overhead Message Protocol for C.S0024B

New protocols

16


• Default Airlink Management Protocol

• Default Connected State Protocol

• Default Packet Consolidation Protocol

• Application layer:

Muliti-Flow Packet Application

Enhanced Multi-Flow Packet Application

Multi-Link Mulit-Flow Packet Application

• Session layer:

Default Session Management Protocol

Default Address Management Protocol

Existing protocols affected (1)

17


• Subtype 3 RTC MAC

• Subtype 2 Physical Layer

• Subtype 4 RTC MAC

• Subtype 3 Physical Layer

Existing Protocols affected (2)

18


• To handle connection between HRPD upper layer to LTE lower layers

HRPD upper layer = Connection Layer and above

LTE lower layer = MAC and below

The behavior of the HRPD control protocols are very different when connected to the LTE tunnel

• Tunneled mode/state:

This mobile enters this mode when it is connected to LTE

SIB 8 provides the overhead parameters, such as System Time, Neighbors PN, etc

“Tunneled State” describes the behavior of the HRPD protocol when the mobile is connected to the LTE tunnel

Under tunneled state, each IRAT protocol behave differently as compare to their normal state

Provide periodic pilot measurement

Why the Inter RAT protocols?

19


• IRAT Initialization state protocol

“Bypass” pilot acquisition and synchronization state

It uses the SIB 8 information to establish timing

• IRAT Idle state protocol

Introduced “Tunneled state” in the state transition diagram

No sleep or wake up

No monitoring of control channel

Perform pilot measurement

Functionalities of IRAT protocols when in tunneled mode (1)

20


• IRAT Route Update Protocol

Pilot supervision is disabled

Radius based RUP message is disabled

• IRAT Overhead Message Protocol

Store overhead parameters from SIB 8

Transmit the OtherRATNeighborList Message

Does not activate supervision timers

Functionalities of IRAT protocols when in tunneled mode (2)

21


Signaling Adaptation Protocol - Context

22


• It keeps record of which air interface (HRPD or non-HRPD) the access terminal is currently receiving service in

• When requested by upper layer protocols, it provides a virtual connection service between the access terminal and the access network over a non-HRPD radio access technology tunnel when the access terminal is receiving service in a non-HRPD radio access technology

• Provides encapsulation of HRPD packets when sent over a non-HRPD radio access technology tunnel

• Triggers idle and active handoffs from a non-HRPD radio access technology to HRPD access networks

• It has a control plane as well as a user plane functionality

SAP functionalities

23


SAP states

Close State

Setup State

Open State

Tx AlternateLinkOpenReq Rx AlternateLinkOpenConf

Rx AlternateLinkOpenFail

Initial State

Tx AlternateLinkCloseConf or Rx AlternateLinkCloseConf

Close State: The virtual connection does not existSetup State: The virtual connection setup is in progressOpen State: In this state the virtual connection is open.

24


• Added alternate packet application subtype for:

MFPA -> Alternate MFPA

EMFPA -> Alternate EMFPA

MLMFPA -> Alternate MLMFPA

• The alternate packet application subtype is to identify the support of eHRPD

• Introduce Protocol ID 7 and 8

Changes to Application Layer

25


• Initial output power calculation

X0 = - Mean RX Power (dBm) + OpenLoopAdjust + PilotInitialAdjust

where:

PilotInitialAdjust = InitialAdjust + min(PilotStrengthCorrectionMax, max(PilotStrengthNominal – PilotStrength, PilotStrengthCorrectionMin)),

• This is necessary due to no access probe power correction

Changes to MAC and PHY Layer

27


eHPRD to LTE

28


• OtherRATNeighborList Message

Broadcast by Overhead Message Protocol

Contains E-UTRAN information for AT to search for E-UTRAN system

Threshold

• InterRATRedirect

Send by Airlink Management Protocol

Contains E-UTRAN redirection information

Two ways :

29


OtherRATNeighborList: E-UTRAN record

Broadcast by Overhead Message Protocol

30


InterRATRedirection: E-UTRAN redirection record

31


3. OtherRATMeasurementRequest

4. OtherRATMeasurementReport

6. InterRATRedirect

eHRPDAN

eAT

1. AT active on eHRPD

8. UE performs Handoff/Attach to E-UTRA

E-UTRA

9. Search more E-UTRA channel or go back to eHRPD based on MMSS rules (conditional)

5. The eAN decides to redirect the eAT

7. The eAT retunes to E-UTRA

2. The eAN decides to determine E-

UTRA Availability

eHRPD to E-UTRAN redirection

32


Circuit Switch Fall Back

33


LTE to 1x tunneling

Lower Layer (Other Access Technology)


Lower Layer Lower Layer

MSOther Access

Technology Entity(ies)IWS



Lower Layer Lower Layer

MSOther Access

Technology Entity(ies)IWS

1x Layer 3

PDU

1x Layer 3

PDU

GCSNA Control

TLAC HeaderGCSNA Header

GCSNA Control

TLAC HeaderGCSNA Header

34


• All supported layer 3 messages are listed under C.R1001

• The supported messages are based on revision and class

Revision 0 Class 0 = Release 8 1xCSFB

Revision 1 Class 0 = Release 9 e1xCSFB

Revision 0 Class 1 = SRVCC

• Example: Messages supported under Release 8 1x CSFB

Data Burst (F/R) Authentication Challenge (F)

Shared Secret Data Update (F) General Page Message (F)

Registration Accepted/Rejected/Request Order (F)

Base Station Challenge Confirmation Order

Registration Message

Supported Layer 3 PDU

35


• Stands for: Tunneling LAC

• Contains essential layer 2 fields

• Two set of fields:

r-csch Addressing Sublayer Record

r-csch Authentication and Message Integrity Sublayer Record

TLAC header

36


GCSNA header

Field Length (bits)

MessageID 8

GCSNAOption 8

AlternativeGCSNAOption_INCL 1

NumAlternativeGCSNAOptions 0 or 8

If NUMAlternativeGCSNAOptions field is included, NumAlternativeGCSNAOptions occurrences of the following field: Otherwise, 0 occurrences of the following field:

{

AlternativeGCSNAOption 8

}

IWSIDIncl 1

IWS_ID 0 or 16

AckRequired 1

StopDupDetect 1

MessageSequence 6

Reserved 0 to 7

TLACEncapsulated1xL3PDU Variable

37


Example GCSNA Callflow

38


• In 1x Rev E, the Alternate Technology Information Message can carries the E-UTRAN record as defined in C.S0097

Idle handoff to LTE

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3GPP2 WRKSP-20120315-xxxr0 2012 Workshop Planning Title: Interworking with LTE Source: Mike Dolan, Tony Lee Abstract: Draft Presentation on Interworking