Adaptive Context Transfer Scheme for Fast Handoff in Proxy Mobile IPv6

Sept. 19, 2008

Jaejong Baek, Jooseok Song{jjb27, jssong}@emerald.yonsei.ac.kr

Department of Computer ScienceYonsei University, Seoul, Korea

NGMAST2008

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Contents

• Introduction• Related work

PMIPv6 Context Transfer Protocol

• Proposed Schemes Proactive Handoff scheme Reactive Handoff scheme Inter Domain handoff scheme

• Performance Evaluatoin• Conclusion and Future work• Q&A

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Abstract

• Goal Propose a new scheme for reducing the handoff latency

in network-based mobility scenarios based on Proxy Mobile IPv6

• Ideas The integration between PMIPv6 and Context transfer

scheme How the context transfer protocol can be achieved in a

PMIPv6 enabled network• Result

Reduce handoff latencies based on adaptive transferring of context information.

Introduction(1)

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Keywords

• PMIPv6 IETF : NETLMM working Group RFC 5213, Aug, 2008 “Proxy Mobile IPv6”, S. gundavelli. Ed.

• Context Transfer Protocol RFC 4067 : basic and generic protocol

operation between access routers to perform context transfer

Introduction(2)

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Mobility concept & definitions

• Terminal mobility Ability for a terminal to change network point of

attachment Discrete terminal mobility Continuous terminal mobility(Handover)

• User mobility Defined as the ability for a user to maintain the same user

identity irrespective of terminals and terminal types• Service mobility

Ability for a user to use the particular(subscribed) service irrespective of the user location and the terminal that is used for that purpose.

Introduction(3)

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Handoff types

• Type(a) Mobile-controlled handoff

• The MN has the primary control over the handover process Network-controlled handoff

• The network has the primary control over the handover process

• Type(b) Proactive(Planned) handoff

• A proactive(expected) handover where some signaling can be done in advance of the MN getting connected to the new AR, e.g., building a temporary tunnel from the previous AR to the new AR

Reactive(Unplanned) handoff• A reactive(unexpected) handover where no signaling is done in

advance of the MN’s move from the previous AR to the new AR

Introduction(4)

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Why Network-based?

• Host-based Mobile IPv4/v6 has not been yet deployed that much. Why host-based MIP is not deployed yet?

• Too heavy specification to be implemented at a small terminal• Battery problem• Waste of air resource

No Stable MIPv4/v6 stack executed in Microsoft Windows OS

• No change in MN protocol stack required!

Related work(1)

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Proxy MIPv6 Overview

• No host stack change for IP mobility • Avoiding tunneling overhead over the air• Re-use of Mobile IPv6

PMIPv6 is based on Mobile IPv6 [RFC3775].• Mobile IPv6 is a very mature mobility protocol for IPv6.• Reuse of Mobile IPv6’s home agent functionality and the

messages/format used in mobility signaling.• Numerous Mobile IPv6 enhancement can be re-used.

PMIPv6 provides solution to a real deployment problem.• Only supports Per-MN-Prefix model

Unique home network prefix(HNP) assigned for each MN. The prefix follows the MN.

Related work(2)

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PMIPv6 Architecture

LMMD(Localized Mobility

ManagementDomain), PMIPv6

domain

MAG1

Host B

Host A

LMA

Proxy Binding Update (PBU)Control message sent out by MAG to LMA to register its correct location

Home NetworkMN’s Home Network (Topological Anchor Point)

Proxy Care of Address (Proxy-CoA)The address of MAG. That will be the tunnel end-point.

IP TunnelA IPinIP tunnel LMA and MAG.

MAG2

LMA: Localized Mobility AnchorMAG: Mobile Access Gateway

LMA Address (LMAA)That will be the tunnel entry-point.

MN’s Home Network Prefix (MN-HNP)CAFE:2:/64

MN’s Home Network Prefix (MN-HNP)CAFE:1:/64

MN Home Address (MN-HoA)MN continues to use it as long as it roams within a same domain

Related work(3)

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Context Transfer Protocol• Goal

to quickly re-establish context transfer-candidate services without requiring the MN to explicitly perform all protocol flows for those services.

to provide an interoperable solution that supports various Layer 2 radio access technologies

Related work(4)

AR

pMAG

AR

nMAGCONTEXT

MN

LMA

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Predictive CTD• Network controlled, initiated by pAR• n/pAR : new/previous Access Router• CTD : CT Data

Feature context (MN’s previous IP and parameters for nAR) which will be used in authentication of MN’s identity

• CTAR : CT Activate Request, CTDR : CTD Reply

Related work(5)

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Reactive CTD• Network controlled, initiated by nAR• CT-Req message• CTD

MN’s previous IP, Feature Context, sequence #, authorization token

Related work(5)

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PMIPv6 Signaling Flow(1)

• PMIPv6 MN Attachment - Signaling Flow

Related work(6)

• PBU : Proxy Binding Update• PBA : Proxy Binding Ack• BCE : Binding Cache Entry • HNP : Home Netwok Prefix

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PMIPv6 Signaling Flow(2) MN Handoff - Signaling Flow

Related work(7)

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Proactive Handoff SchemeProposed schemes(1)

• Authentication information - MN-ID, shared secret key• Authorization information - Lists of authorized services• Accounting information. - Usage record of resources and services

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Reactive Handoff SchemeProposed schemes(2)

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Inter domain handoff schemeProposed schemes(3)

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Analytic modeling

• Cost functions(MIPv6 vs Proposed) Location update(CL)

• Existing :• Proposed :

Packet delivery(CP)• Existing : • Proposed :

Total cost : CT = CL + CP

)( ch LnL lL

lnl Ds)()( lnllol DsDs

Performance evaluation(1)

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Notations

• : the average number of LMD crossings• : the number of CNs.• : the location update cost to the HA• : the location update cost to the CN• : the location update cost to the LMA• : the packet delivery cost through the LMA• : the packet arrival rate through the new LMA• : the packet arrival rate through the old LMA• : the average session size• = 1.5 : the packet tunnel cost

nhLcL

lDnlols

lL

Performance evaluation(2)

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Comparison

• Total cost for inter-domain handoff

Performance evaluation(1)

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Conclusion and Future Work

• Network-based localized mobility management Proactive and reactive schemes. adaptive context transfer schemes

• Context transfer protocol reduces the inter and intra handoff latency by avoiding the re-initiation of signaling to and from the MN.

• In the future we will focus on the detail message structure like how it will be

implemented without modifications on the current PMIPv6 architecture and present performance results to assess the effectiveness of this scheme.

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References[1] J. Lougney, M. Nakhjiri, C. Perkins, and R. Koodli,“Context Transfer Protocol (CXTP),” RFC 4067, IETF,July 2005,

Tech. Rep.[2] P. De Silva and H. Sirisena, “A mobility management protocol for IP-based cellular networks,” Wireless

Communications, IEEE [see also IEEE Personal Communications], vol. 9, no. 3, 2002.[3] S. Gundavelli and K. Leung, “Localized mobility management using proxy mobile IPv6: draft-

gundavellinetlmmmip61] J. Lougney, M. Nakhjiri, C. Perkins, and R. Koodli, “Context Transfer Protocol (CXTP),” RFC 4067, IETF, July 2005, Tech. Rep.[2] P. De Silva and H. Sirisena, “A mobility management protocol for IP-based cellular networks,” Wireless

Communications, IEEE [see also IEEE Personal Communications], vol. 9, no. 3, 2002.[3] S. Gundavelli and K. Leung, “Localized mobility management using proxy mobile IPv6: draft-gundavellinetlmmmip6-

proxy-11. txt,” IETF draft, February,2008.[4] J. Kempf et al., “Goals for Network-based Localized Mobility Management (NETLMM),” RFC 4831, April,2007.[5] H. Duong and S. Dadej, A.and Gordon, “A General Framework for Context Transfer in Mobile IP Networks,”

Vehicular Technology Conference, VTC 2006- Spring. IEEE 63rd, vol. 2, pp. 1017–102 176–88, 2006.[6] D. Johnson, C. Perkins, and J. Arkko, “Mobility Support in IPv6,” RFC 3775, June, 2004.[7] C. Politis, K. Chew, N. Akhtar, M. Georgiades, R. Tafazolli, and T. Dagiuklas, “Hybrid multilayer mobility

management with AAA context transfer capabilities for all-IP networks,” Wireless Communications, IEEE [see also IEEE Personal Communications], vol. 11, no. 4, pp. 76–88, 2004.

[8] M. Georgiades, N. Akhtar, C. Politis, and R. Tafazolli, “Enhancing mobility management protocols to minimise AAA impact on handoff performance,” Computer Communications, vol. 30, no. 3, pp. 608–618, 2007.

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Q&A