1. Mobility Management Using Virtual Domain in IPv6-based Cellular Networks Jae-Kwon Seo, Kyung-Geun Lee Sejong University, Korea

2. Contents Introduction Related works Proposed scheme Simulation Experiment Numerical Analysis Conclusion

3. Introduction • Mobility support in IPv6 (MIPv6) • Home Agent (HA) • Temporary address, Care-of-Address (CoA) • A mobile node(MN) moves to a foreign network, • Binding update : MN->HA

4. 1 2 5 4 3 Intercept & Encapsulation Basic Operation of MIPv6 MN HA ①,② : Binding Update/Acknowledge ③,④,⑤ : First User Data Packet Delivery CN

5. Authenticating binding-update requires 1.5 RTT between MN and CN • One RTT is needed to update the HA • A Mobile Node has to register to the HA every handover occurs

6. Hierarchical Mobile IPv6 (HMIPv6) • Two addresses • Regional CoA (RCoA) : MAP prefix based • On-link CoA (LCoA) : current AR prefix based • Mobility Anchor Point (MAP) • Local HA • Intercepts the packets destined to RCoA • Tunnels the packets to the LCoA • Two binding updates • Regional binding update : RCoA -> HA • Local binding update : LCoA -> MAP

7. HMIPv6 Operation (Home address, RCoA) HA CN Internet Home BU MAP MAP LCoA ) (RCoA, LCoA’) MAP domain Local BU Local BU oldAR newAR MN 7

8. MIPv6 vsHMIPv6 AR HA or CN MN MIPv6 reduces wired signaling cost & reduces update latency HA or CN MAP MN AR HMIPv6

9. HMIPv6 (cont.) • Efficiently in supporting micro-mobility • Within a MAP domain • Not appropriate in supporting macro-mobility • Inter-MAP domain handover • longer handover latency with more packet loss

10. Architecture of Multi-layer HMIPv6

11. Related works • Velocity-based MAP selection scheme • Fast MNs select the HMAP • Slow MNs select the LMAP • Load control scheme • The MAP checks the maximum number of MNs • Decides whether to receive or to reject a registration request of the MN • Rejected MN selects the next candidate MAP • Velocity based + load control, velocity based + moving range of the MN…

12. Related works (cont.) Estimated velocity may not reflect the current velocity MNs do not always move with constant velocity and direction Slow MN eventually encounters the inter-domain handover but this case is not considered This paper proposes a MAP changing scheme using a virtual domain (VD)

13. Proposed scheme • Simple method • Considering only current moving direction and position of the MN • Reduces significant overhead generated by complex computation procedure • Not responsible for wrong prediction • Virtual domain • Assigning ARs to the domain of the Higher layer MAP (HMAP)

14. Proposed scheme (cont.) 1 : MN moves to the changing point of the VD 2 : MAP changing request message 3 : Binding Update (LCoA) 4 : Biding Ack. 5 : Binding Update (RCoA) 6 : Binding Ack. 6 5 4 3 Changing Point

15. Proposed scheme (cont.)

16. MAP changing procedure only

17. Proposed scheme (cont.) • The changing point is AP (802.11) or BS(802.16) • The MAP changing procedure is similar to the inter-domain handover • Except for the generating procedure of the LCoA • Inter-domain handover occurs • MN completes the handover using binding update with LCoA only. • Does not generate packet loss • The MAP changing procedure changes the routing path only from CN to MN while receiving packets • Load concentration of a HMAP is distributed in VD • MNs registered with HMAP and LMAP coexist in VD

18. Performance evaluation • Simulation topology • NS-2

19. Simulation results Furthest selection scheme Nearest selection scheme MAP changing scheme RTT between MN and CN

20. Simulation results (cont.) When the ping-pong movement occurs

21. Simulation results (cont.) Average number of the encapsulated packets at HMAP (HMAP load)

22. Numerical analysis • MAP domain consist of rings State diagram for random walk mobility model 22

23. Analytic Modeling A ring k is composed of 6k subnets except the ring 0 The number of subnets If the MN is located in a subnet of ring k The probability that a movement will result in an increase or decrease in the distance from the center subnet

24. Analytic Modeling Markov chain as the distance between the current location of the MN and center of the domain The transition probabilities where q is the probability that a MN stays in the current subnet The steady state probability

25. Simulation network architecture for numerical analysis

26. Binding update cost

27. Packet processing cost & HMAP load

28. Conclusion • HMIPv6 has been proposed to compensate for the problems in employing MIPv6 • but, longer handover latency than MIPv6 when inter-domain handover occurs • load concentration at a particular MAP • This paper proposes MAP changing scheme using VD of HMAP • predictably changes the MAP • May not assure accurate prediction • Reduces overhead generated by complex computation procedure • Performance evaluation • Average number of registration with HA and CN is increased • However, MAP changing scheme reduces inter-domain handover latency • And load concentration of the HMAP is distributed • Future work • How to decide the optimal range of a VD • Simulate the proposed scheme in extended topologies

29. Thank you for your attention ! Question ?