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 CENTERKAUSHIK CHAKRABORTY, UNIVERSITY OF MARYLANDSAJAL 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 act

s as a domain-wide point for packet redirection• A subnet agent (SA) provides subnet-specific mobility service

s

Architecture Functional Specification

Internet HACN

MAGCoA

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-l

evel 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

RoutingTable update

TunnelUpdate

Paging Paging cache/Multicast

Multicast

FunctionDeployment All nodes Some nodes

Cellular IP architecture

Packets will be first routed to the host's home agent and then tunneled to

the gateway

The gateway "detunnels'' packets and forwards them toward base stations

Packets transmitted by mobile hosts are first routed to the gateway and

from there on to the Internet

MOBILE IP

CELLULAR IP

Cellular IP Handoff

X : from D

X : from D, E

X : from E

X : from C

E

B

D

R

A

C

F

G

Internet withMobile IP

GW X

X : from F

HAWAII architecture

HAWAII-suboptimal routing problem

Cellular IP W0 －＞ W4 －＞ AP8

HAWAII W0 －＞ W1 －＞ W2 －＞ W3 －＞ W4 －＞ AP8

Conclusion