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IEEE 802.21 MEDIA INDEPENDENT HANDOVER

DCN: 21-07-0256-00-0000

Title: Handover between 3GPP and non-3GPP networksDate Submitted: July 16, 2007

Presented at IEEE 802.21 session in San Francisco, CA, USA

Authors or Source(s): Juan Carlos Zuniga, Ulises Olvera-Hernandez

Abstract: This contribution provides an overview of current 3GPP HO approaches compared to the 802.21 specification.

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IEEE 802.21 presentation release statements

• This document has been prepared to assist the IEEE 802.21 Working Group. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.

• The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.21.

• The contributor is familiar with IEEE patent policy, as outlined in Section 6.3 of the IEEE-SA Standards Board Operations Manual <http://standards.ieee.org/guides/opman/sect6.html#6.3> and in Understanding Patent Issues During IEEE Standards Development http://standards.ieee.org/board/pat/guide.html> 

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Outline

• Background

• Some proposed HO solutions in 3GPP SA2

• 3GPP Accepted solutions

• Suggested 802.21 way forward

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Background (1/2)

• 802.21 is a specification meant to provide HO hooks at L2 and below in order to assist HO (e.g. for L3 and above)

• 802.21 can be used to enhance several handover schemes• E.g. WiMAX, WiFi, 3GPP GAN, 3GPP IMS, 3GPP VCC• Other

• 802.21 is only mentioned as a handover option in• 802.11u• 802.16g

• No other standard makes specific reference to 802.21 for assisting handovers

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Background (2/2)

• 3GPP has started several activities to study the different approaches that should be taken to perform handover between 3GPP and non-3GPP networks

• RAN2 workshop• SA2 session

• During the last 3GPP meeting in Orlando, 3GPP (SA2 and RAN2) decided to take two different and specific approaches:

• Handover between 3GPP and cdma2000 networks• Handover between 3GPP and WiMAX networks

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Some HO solutions presented in 3GPP (1/5)

• Doc S2-072450, S2-072451, and S2-072452 (Motorola)

• Pre-registration before HO decision through Forward Attachment Function

• Handover assistance by sending context before HO decision

Serving GW

HPLMNVPLMN

3GPP accesses S1-U, S4, S11

S8a/bNon- 3GPPNetworks

UE Trusted non- 3GPP IP Access

Untrusted non- 3GPP IP Access

Serving GW

ePDG

SGi

Serving GW

3GPP accesses

S5

S1- U, S4, S11

PDNGW

FAF(MME emul)

S2b

S2a

Su

MME

S10

S11

3GPP accesses

S1-C

HSS

S6a

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Some HO solutions presented in 3GPP (2/5)

• Doc S2-072324 (Samsung)

• Handover preparation through IWF• Handover assistance by exchanging HO information between source and

target networks through Inter-working Function

AN

IWF

non-3GPP3GPP

S5

Sx

S2a

Core Network

PDN GW

MME

Serving GW

eNodeB

S11

S1_US1_MME

HSS AAAWx

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Some HO solutions presented in 3GPP (3/5)

• Doc S2-072923 (InterDigital)

• MIH for non-3GPP HO support • Handover assistance by sending context before HO decision

Non-3GPPAN

MME

e-NBBS

GW

1. Forward Relocation Request

4. Forward Relocation Response

6. Forward Relocation Complete

7. Forward Relocation Complete Ack

UE

MIHE

2. MIH N2N HO Commit Request

3. MIH N2N HO Commit Response

5. MIH N2N HO Complete Request

8. MIH N2N HO Complete Response

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Some HO solutions presented in 3GPP (4/5)

• Doc S2-072431 and S2-072613 (Qualcomm)

• UE-MME NAS interface S23 and tunnel to target system• Handover assistance by sending context before HO decision

SGi

Serving Gateway

E-UTRAN

Non-3GPP Access

S2 S23 tunnel

S5

PDN Gateway

MME

S11

Non-3GPP Node

LTE “L2 Tunnel”

Non-3GPP access “NAS signalling”

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Some HO solutions presented in 3GPP (5/5)

• Other companies presented different HO solutions, such as• S2-072696 HO from trusted non-3GPP access to UTRAN

(Intel)• S2-072654 Inter-RAT mobility to non-3GPP (IPWireless,

Nextwave)• SA2-07308 Principles for network discovery, selection, and

traffic steering (Marvell, Ericsson, Qualcomm Europe, InterDigital, Nokia Siemens Networks, TARI, Telcordia, Intel )

• Etc

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3GPP Accepted Decisions

• 3GPP (SA2 and RAN2) decided to deal with non-3GPP HO’s by separating them into two different technologies (*):

• Handover between 3GPP and cdma2000 networks• Tunnel approach was accepted

• Handover between 3GPP and WiMAX networks• Empty section

• Having two separate approaches in 3GPP for 3GPP2 and WiMAX does not mean that there will be two different solutions it just means that no approach is on the table for WiMAX

(*) Proposed by docs S2-072977/S2-072658 Support for E-UTRAN to 3GPP2 HO (Verizon, Vodafone, Nortel, Ericsson)

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Conclusions

• In order to be a successful specification, IEEE 802.21 has to become the best technical and commercial solution for HO between IEEE 802 technologies

• 802.21 needs to get acceptance by and strong support from 802.11, 802.16, 802.3, 802.20, etc.

• Having support from other 802 groups is first needed before 802.21 gets acceptance externally

• The fact that 3GPP has decided to take two separate approaches for two networks (i.e. 3GPP2 and WiMAX) does not help the 802.21 case