Cellular IP:A New Approach to Internet Host Mobility

Reporter ：江俊毅

Outline

Cellular IP introduction Routing Protocol Paging Paging & Routing caches Handoff Conclusion

Introduction Mobility overview Macro-mobility

Mobile IP MIPV6 MIPV4

Micro-mobility Cellular IP HAWAII HIP

Cellular IP Cellular IP represents a new mobile host

protocol simple, and flexible protocol for highly mobile

hosts CIP supports local mobility & efficiently internet

works with Mobile IP

Wirelss access networks and mobile IP

Wireless Access network Model

MH

B

DInternet with

Mobile IP

R

R

A

CE

F

G

Home agent of MH

Gateway

Beacon signal

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 Paging Idle mobile hosts that receive a packet move

from idle to active state, start their active-state-timer and immediately transmit a route-update packet.

This ensures that routing cache mappings are established quickly

Mobile host state machine

Efficient Location Management

Two parallel structures of mappings (PC &RC)1 - idle MH keeps PC upto-date2 - PC mappings used to find the loc of idle MH 3 - maintains RC mappings until actively connected4 - routing of data packets to MH

X XX

PC RC

Service Area

Mobile Host1 2 3 4

PAGING &ROUTING

Illustration of Paging

MHB

D

R

A

C

E

F

G

Internet withMobile IP

GW X

Paging-update packets create mappings in PCs

X : from GX : from C

Paging-update

I don’thave a PC

PCs updated for a moving host

X : from GX : from C

B

D

R

A

C

E

F

G

Internet withMobile IP

GW X

X : from F

X : from F,G

G times out

MH

No change in PC at A

X : from FX : from C

B

D

R

A

C

E

F

G

Internet withMobile IP

GW

MH X

Paging packets are routed to the mobile host by PCs

X

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

Paging & Routing caches

Handoff Cellular IP handoff

Hard handoff Semi-soft handoff

Hard handoff During the Handoff Latency the downlink

packets are lost. Semi-soft handoff

Improvement over Hard Handoff

Hard-Handoff

2.MN send Route Update Packet to GW

3.BSs are refresh RS

4.GW send data packets to MN

1.MN From Old BS toNew BS

Semi soft-Handoff Improvement over Hard Handoff ; NO packet

loss & smooth handoff. Need for buffering at the cross over point :For

smooth handoff

Compare Mobile IP & Cellular IP Location management

Mobile IP: Care-of-address Cellular IP: paging update packet

Routing Mobile IP: registration Cellular IP: routing cache

Handoff Mobile IP: encapsulation, triangle routing Cellular IP: routing cache

Conclusion Cellular IP represents a new approach to IP host

mobility Cheap passive connectivity using PC and

RC Flexible handoff The important issue :

Authentication and security

End

Thanks~