IDMP: AN INTRADOMAIN MOBILITY MANAGEMENT PROTOCOL FOR NEXT-GENERATION WIRELESS NETWORK SUBIR DAS, ANTHONY MCAULEY AND ASHUTOSH DUTTA, TELCORDIA TECHNOLOGIES INC. ARCHAN MISRA, IBM T. J. WATSON RESEARCH CENTER KAUSHIK CHAKRABORTY, UNIVERSITY OF MARYLAND SAJAL K. DAS, THE UNIVERSITY OF TEXAS AT ARLINGTON IEEE Wireless Communications • June 2002 Reporter：Chun - I Chen

Outline IDMP Overview The architecture of IDMP Handoff Paging Comparison Conclusion

IDMP IDMP is a two-level generalization of the Mobile IP architecture, with a special node called the mobility agent (MA) providing an MN a domain-wide stable point of packet redirection It will be independent of any specific solution for global (interdomain) mobility management IDMP offers intradomain mobility by using multi-CoA The mobility agent (MA) is similar to a MIP-RR GFA and acts as a domain-wide point for packet redirection A subnet agent (SA) provides subnet-specific mobility services

Architecture Functional Specification Internet HA CN MA GCoA SA1 SA2 SA3 SA4 Subnet A Subnet B Subnet C Subnet D MN LCoA

IDMP (cont’d) Local care-of address (LCoA) This identifies the MN’s attachment to the subnet Unlike MIP’s CoA, the LCoA in IDMP only has local scope By updating its MA of any changes in the LCoA, the MN ensures that packets are correctly forwarded within the domain Global care-of address (GCoA) This address resolves the MN’s current location only up to a domain-level granularity and hence remains unchanged as long as the MN stays within a single domain By issuing global binding updates that contain this GCoA, the MN ensures that packet are routed correctly to its present domain

The architecture of IDMP

Architecture Functional Specification Foreign Agents/ DHCP(DRCP) Servers at the subnet level Provide MN with a locally-scoped address which identifies mobile location within the domain. Mobility Agents (MA) distributed within the domain Multiple MAs for load-balancing and redundancy within the domain. Provides MN with a global care-of address that stays constant within the domain. MN’s location is globally known only up to the MA-level granularity. In current implementation (in this paper), HA/CNs as in conventional Mobile IP

Architecture Functional Specification MN retains the same MA (global care-of address) within the same domain All packets from the global Internet tunneled to the MA, which acts as a single point of enforcement/accounting. MA tunnels these packets to MN’s current LCOA. On subsequent movement within the domain, MN only obtains a new local COA. No need to update the HA or CNs. MN updates its MA with its new local COA.

Basic Architectural Features A multi-CoA Intradomain mobility solution MA->GFA /SA->FA Each MN obtains two concurrent CoAs, LCoA and GCoA MN updates its MA with its new LCoA at every Intradomain Handoffs, while it updated its HA with GCOA during any interdomain handoff Multiple MAs in a domain Load balancing

Path setup At power-up, MN obtains a LCoA from SA In IDMP’s SA mode, MN must obtain LCoA from Agent Advertisement of its SA In collocated mode, MN obtains its LCoA from DHCP server MN receives MA’s CoA, GCoA, from SA or DHCP server MN informs the MA of its new LCoA using intradomain location update msg and updates its HA with GCOA Now, packers from remote CN are forwarded to MN’s GCoA and intercepted by MA, tunnels them to MN’s current LCoA

IDMP message flow during the initial intradomain location update

IDMP call flow during subsequent intradomain movement

Handoff MN moves from SA2 to SA3 subnet, MN or SA2 generated movementImminent msg to MA On reception of this msg, MA multicasts all inbound packets to the entire set of neighboring SA(SA1,SA3) which buffer them in per-MN buffers When MN performs a subnet-level registration with SA3, SA3 can immediately forward all buffered packets to the MN Buffered packets at other SAs are discarded after specified time MN updates the MA with its intra-domain location

Paging Paging Area A set of subnets An idle MN updates its location only if it detects moved out of its current PA When MA receives packets for a MN which is currently registered but in idle mode, it multicasts Page Solicitation packet to all subnets in current PA When the dormant MN is paged, it obtains LCoA from the SA to which it is currently attached and sends a location update to the MA When the MN reregisters with the MA, the buffered packets in the MA are forwarded to the MN

Micro-Mobility Solutions To reduce signaling load and delay to the home network during movements within one domain Tunnel-based micro-mobility schemes Mobile IP regional registration (MIP-RR) Hierarchical Mobile IP (HMIP) Intradomain mobility management protocol (IDMP) Routing-based micro-mobility schemes Cellular IP (CIP) Handoff Aware Wireless Access Internet Infrastructure (HAWAII)

Simple Comparison CIP/HAWAII IDMP Handoff/ Path setup Routing Table update Tunnel Update Paging Paging cache /Multicast Multicast Function Deployment All nodes Some nodes

Cellular IP architecture

MOBILE IP CELLULAR IP Packets transmitted by mobile hosts Packets will be first routed to the host's home agent and then tunneled to the gateway Packets transmitted by mobile hosts are first routed to the gateway and from there on to the Internet MOBILE IP The gateway "detunnels'' packets and forwards them toward base stations CELLULAR IP

Cellular IP Handoff E B D R A C F G Internet with Mobile IP GW X : from D X : from E X : from C E B D R A C F G Internet with Mobile IP GW X X : from F X : from D, E

HAWAII architecture

HAWAII-suboptimal routing problem Cellular IP W0 －＞ W4 －＞ AP8 HAWAII W0 －＞ W1 －＞ W2 －＞ W3 －＞ W4 －＞ AP8

Conclusion