* joint work with T. Chen, S. Han, and K. Chow Mobility Support over IEEE Wireless Access Networks Shanchieh Jay Yang Networked Multimedia Research Department Bell Labs

Mobility over Networks Router AS1 AS2 AS3AS4 MH AS5AS6 Micro-mobility (intra-domain roaming)Macro-mobility (inter-domain roaming) * fixed IP address for MH => continuous session / / / * Access Server (AS) : Layer 2 bridge + IP forwarding capability home subnetforeign subnet

Problem Statement Efficient micro- and macro-mobility support for clients on IEEE wireless access networks. Design goals: - simplicity - compatibility - performance enhancement

Access Network (PubLAN) Router AS2 AS3AS4AS1 MH proxy IAPP handoff MH proxy home subnetforeign subnet * unable to roam to foreign subnet??? ??? MH ?????? traffic to

Mobile IP: IP tunneling Router HA FA1FA2 MH * intra-domain roaming in foreign subnet still needs to re-register. * solves macro-mobility but inefficient for micro-mobility. MH registration tunnel registration MH tunnel

Mobile IP + IAPP Extension Router AS2 AS3AS4AS1 HAFA home subnetforeign subnet MH proxy handoff * roaming in the home subnet: set proxy to attract traffic * macro-mobility: Mobile IP (IP tunneling) MH tunnel proxy * micro-mobility: extend IAPP handoff to redirect traffic when roaming within a subnet MH handoff redirect traffic

Mobile IP + IAPP Extension Router AS2 AS3AS4AS1 HAFA home subnetforeign subnet MH proxy handoff * roaming in the home subnet: set proxy to attract traffic * macro-mobility: Mobile IP (IP tunneling) MH tunnel * micro-mobility: extend IAPP handoff to redirect traffic when roaming within a subnet MH handoff redirect traffic

Supporting Micro/Macro Mobility Representative cases*: –roaming within home subnet –roaming into foreign subnet –roaming within foreign subnet *illustration for supporting non-mobile-IP clients

Roaming within Home Subnet Router AS1AS2 MH beacon reassoc MH handoff req handoff ack proxy ARP for route to via RF device

Roaming into Foreign Subnet Router AS2AS3 MH tunnel registration beacon reassoc handoff (HA,FA) tunnel - proxy ARP for IP tunnel to FA(AS3) for client IP tunnel from HA(AS2) for client route to via RF device HA FA

Roaming within Foreign Subnet Router AS2AS3 MH beacon reassoc tunnel AS4 handoff (HA,FA) chg route to MH - proxy ARP for IP tunnel to FA(AS3) for client IP tunnel from HA(AS2) for client route to via AS4 - route to via RF device HAFA

Simplicity Only light weight extension/addition in Access Server (AS) (neither router nor client needs to be changed). layer 2 protocol IAPP FA (minimal) + - relay advertisement from other FA - handoff - get HA/FA info - change FA route to client - beacon/re-association - FA advertisement client FA Old AS HA - tunnel registration

Compatibility Support both non-mobile- and mobile-IP clients. After re-association and handoff... layer 2 protocol IAPP FA (minimal) + mobile client HA IP tunnel FA advertisement client solicitation/FA advertisement + FA + IP tunnel

Performance : Micro-Mobility Signaling path: –faster intra-domain handoff in foreign subnet. –Let n = # hops between FA and HA, IAPP+ : 1(handoff) + 1(chg_rt) = 2 MIP : 1(handoff) + n(tunnel) = n+1 HFA : 1(handoff) (tunnel) = 2 + Data Path: –one hop (FA) more than Mobile IP. HAFA n=6

Performance : Macro-Mobility Mobility Server (MS) –Signaling path: background signaling to establish a shortcut tunnel to FA. –Data path : compromise between Mobile IP and optimal route update, e.g. HAWAII. –Savings over Mobile IP: n+1 = # hops between MS & HA. 2n-2 for traffic go through the router MS attached to. HAFA MS tunnel data traffic register

Future Work (I) Mobility Server : –optimal location to install MS(s)? –optimal selection of MS(s) to register? –tradeoff between "benefit to more traffic" and ”more savings in terms of hop count”. HAFA MS1 tunnel MS2 80% traffic 20% traffic

Future Work (II) Client operational mode : –non-Mobile-IP mode : Internet access –Mobile-IP mode : private network access –simultaneous sessions for both type of access? HA/FA selection : –dedicated HA and FA? –load balancing? –hierarchical FA?

Summary A proposal which integrates –Mobile IP (macro-mobility), – handoff capability (micro-mobility). A proposal aiming at a combination of –simplicity, compatibility, and performance. Demonstration –next door...