mMOM: Efficient Mobile Multicast Support Based on the Mobility of Mobile Hosts

1. mMOM: Efficient Mobile Multicast Support Based on the Mobilityof Mobile Hosts YUNGOO HUH and CHEEHA KIM Presented by Kiran Kumar Bankupally

2. Agenda • Terminology • Introduction • Some implementation details • mMOM: mobility based MObile Multicast support • Performance Evaluation • Conclusions

3. Introduction • Necessity • What is multicasting? • sender sends a single datagram to the multicast address, and the routers take care of making copies and sending them to all receivers that have registered their interest in data from that sender. • One way streaming media • Mobile IP!!!!

4. Mobile IP • Mobile IP is a Protocol that allows mobile device users to move from one network to another while maintaining a permanent IP address • A Mobile IP consists of • HA-Home Agent • FA-Foreign Agent

5. Cont.. • Home Agent • stores information about mobile nodes whose permanent address is in the home agent's network • Foreign Agent • stores information about mobile nodes visiting its network care-of addresses, which are used by Mobile IP

6. More on Mobile IP Mobile IP protocol defines the following: • an authenticated registration procedure by which a mobile node informs its home agent of its care-of-address • an extension to ICMP Router Discovery, which allows mobile nodes to discover prospective home agents and foreign agents • the rules for routing packets to and from mobile nodes, including the specification of one mandatory tunneling mechanism and several optional tunneling mechanisms.

7. Mobile IP & multicast • Two types of multicasting • Remote Subscription • Bidirectional Tunneling • Relating this to the course.

8. Remote Subscription • MH moves to a foreign network, it subscribes to the multicast group on the foreign network.

9. Cont….. • Advantages:- • option is simple and provides optimal routing efficiency • Disadvantages:- • will overload the multicast routers for multicast tree management • suffer from packet losses at roaming, owing to the set-up time associated with multicast subscription (later it was rectified)

10. Bi directional Tunneling • When MH is away from its home network, a bi-directional tunnel between its HA and FA is set up.

11. Cont….. • Advantages:- • guarantees multicast packet delivery against roaming • handles the mobility of both the source and recipients • Disadvantages:- • the routing path for packet delivery may be far from optimality • tunnel convergence problem can occur

12. mMoM • Mobility based mobile multicast support • Uses Registration Process • FA maintains List of MH registrations

13. The Process • MH moves first to a foreign network, a bi-directional tunnel to its HA is set up in mMOM as the BT option • If MH does not switch its foreign network, it must perform re-registration to its HA via the FA again before the expiration of its lifetime • Implies Temporal Locality in FA Network

14. Performance Evaluation • Analytical Model • Analytical Results

15. Our Part • Assumptions • single multicast group with one source • source is a fixed host and other members of the multicast group are MHs. • Group membership does not change dynamically and there are M MHs belonging to the multicast group • each network has only one FA

16. Cont…. • MH’s re-registration time and residence time in FA are exponential random variables with parameters τ and μ, respectively. • Networks are homogenous and are distributed in n × nmatrix with each node has exactly four neighbors. • MH is assumed to move to one of four directions randomly with equal probability

17. Our network Structure

18. Final Assumption • the interarrival time of MHs at a FA is exponentially distributed with mean rate λ. • λ = μ/(n2 − 1) (first proof)

19. Markov chain describing the behavior of MH under the n × n homogenous networks

20. Here we go……

21. The limiting Probabilities are!!!!!

22. Substituting that in the equation above gives you Where 0 < a, b < n+ 1

23. The given diagram reduces to • Markov chain for describing the arrival rate of single MH to FA positioning (a, b) under the n × n homogenous networks.

24. Back to the problem • Each state is represented by (α, β) • α indicates the number of MH serviced by the FA, • β is either • 0 (denoting that the FA is not involved in the multicast service) • 1 (denoting that the FA is already in the multicast service)

25. Markov chain describing the behavior of FA under mMOM.

26. Representation

27. Markov chain describing the behavior of FA under mMOM.

28. By assuming

29. Now the equations reduce to the probability Pkin nothing but the steady state probability in M/M/∞//M model shown!!!!!!!

30. Equations • Thus the number of MHs in the FA is given by And then these set of equations were given

31. More…… • multicast tree management overhead (Em) • number of join and leave operations per unit time, the overhead in RS, BT, MoM, and mMOM can be expressed as follows

32. And more… • expected number of tunneling paths to FA (nd)

33. Analytical Results • Assumptions • Departure Rate (μ)=1 • ratio of the mobility rate to the re-registration rate (MRR) MRR= μ/τ

34. The tree management overhead

35. The expected number of tunneling paths

36. The tree management overhead

37. The expected number of tunneling paths in FA

38. The total cost CT

39. Conclusion • Improved efficiency in terms of optimal delivery path and frequency of multicast tree reconfiguration

40. Future Work • how to handle the co-located care-of-address approach in mMOM