1. Cellular IP: A New Approach to Internet Host Mobility
Reporter：江俊毅

2. Outline Cellular IP introduction Routing Protocol Paging
Paging & Routing caches
Handoff
Conclusion

3. Introduction Mobility overview Macro-mobility Micro-mobility Mobile IP
MIPV6
MIPV4
Micro-mobility
Cellular IP
HAWAII
HIP

4. 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

5. Wirelss access networks and mobile IP

6. Wireless Access network Model
Internet with
Mobile IP R A C E F G
Home agent of MH
Gateway D B
Access network:: is a group of cells
A network model primarily consists of base stations interconnected by wired links as shown:
Apart from base stations the network can contain node that have no radio devices. They do not communicate with the MHs, but route IP packets with in the access network. E.g. Node E
Wireless access networks are connected to the global internet by routers called Gateways. These acts as both the Home agent and Foreign agent for visiting hosts
START ANIMATION
- BEACON PACKETS BY BS (MH acquires a c/o address by listening to the advertisement)
- REGISTERING THE C/O ADDRESS (The mobile host, with the help of its foreign agent informs its home agent to set up a binding between its Home Address and its c/o Address. *This message is sent on a hop-by-hop basis to the GW along the uplinks.
HOME AGENT:
Authenticates the binding update messages
Updates its binding table
Sends acknowledgement back to the GW
Beacon signal MH

7. 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

8. 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

9. Mobile host state machine

10. Efficient Location Management
PAGING &
ROUTING X PC RC
Service Area
Mobile Host 1 3 2 4
Two parallel structures of mappings (PC &RC)
1 - idle MH keeps PC upto-date
2 - PC mappings used to find the loc of idle MH
3 - maintains RC mappings until actively connected
4 - routing of data packets to MH
Efficient Location Management
Tracking MHs closely requires control messages to be sent after every migration, and to process that becomes very inefficient
On the other hand letting them roam untracked, and searching for them, when there is data to send is inefficient and highly unscalable
So efficient location management scheme is required that maintains loc info of idle MHs with out overloading the network

11. Illustration of Paging
I don’t
have a PC MH B D R A C E F G
Internet with
Mobile IP GW X
X : from C
X : from G
Paging-update
Paging-update packets create mappings in PCs

12. PCs updated for a moving host
No change
in PC at A
X : from G
X : from C B D R A C E F G
Internet with
Mobile IP GW X
X : from F
X : from F,G
G times out MH

13. Paging packets are routed to the mobile host by PCs
X : from F
X : from C B D R A C E F G
Internet with
Mobile IP GW MH X X

14. 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

15. Paging & Routing caches

16. Handoff Cellular IP handoff Hard handoff Semi-soft handoff
During the Handoff Latency the downlink packets are lost.
Improvement over Hard Handoff

17. Hard-Handoff 1.MN From Old BS to New BS
2.MN send Route Update Packet to GW
3.BSs are refresh RS
4.GW send data packets
to MN

18. Semi soft-Handoff
Improvement over Hard Handoff ; NO packet loss & smooth handoff.
Need for buffering at the cross over point :For smooth handoff

19. 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

20. Conclusion Cheap passive connectivity using PC and RC Flexible handoff
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

21. End
Thanks~