MOBILITY AND SERVICE MANAGEMENT FOR FUTURE ALL-IP BASED WIRELESS NETWORKS

1. MOBILITY AND SERVICE MANAGEMENT FOR FUTURE ALL-IP BASED WIRELESS NETWORKS Weiping He Preliminary Proposal, Dec. 12, 2006 Committee: Dr. Ing-Ray Chen, Committee Chair Dr. Csaba Egyhazy Dr. Mohamed Eltoweissy Dr. Chang-Tien Lu Dr. Gregory Kulczycki

2. Outline • Introduction • Research Statement and Methods • Related Works • Dynamic Mobility Anchor Points • IMSA: Integrated Mobility and Service Management Architecture • Applications of Proxy for Integrated Cache Consistency and Mobility Management • Conclusion and Future Work

3. Mobility Management Enables networks to locate the MN for service delivery and to maintain active connections as the MN is moving. • Location Management. • Keep track the location of MNs. • Include location registration and call delivery. • Handoff Management. • An MN keeps the connection active when the MN moves. • Four tasks • Deciding when to handoff • Selecting a new AP • Acquiring resources • Informing the old AP reroute the packet and transfer state information.

4. Service Management Ensures mobile nodes to get data services reliably, correctly and efficiently. • Service request management • Request handling: accept service requests and transform requests into proper form. • Request delivery: forward server replies to the MN. • Request accounting, authentication and authorization (AAA) • Service handoff management An MN keeps its services connection when it moves from one access point to another one.

5. Research Statement • Develop new mobility and service management schemes for future all-IP systems to minimize the overall network cost. Future all-IP based wireless networks provide network services based on the ubiquitous communication protocol: IP. Using per user based proxy to integrate mobility and service management to minimize the overall cost.

6. Future All-IP based Wireless Network Architecture • Home agent • Registration • Current location • Forward packets • Correspond node Provides various services • Access router • Offers IP connectivity to MNs • Powerful and flexible to host proxies to perform cross layers functions. • Access Point Offers the wireless link connection to MNs

7. Research Challenges and Motivations • Mobile connectivity is highly variable. • Mobile nodes are relative resource-poor. • Workload to ARs is highly variable. • Mobility and service characteristics of MNs are highly variable • Vast majority of terminals will be mobile in a few years. The vast majority of traffic will originate from IP-based applications.

8. Research Methods • Extensive background research. • Investigate of new techniques. • Performance study via modeling and analysis. • Demonstration of the applicability of proposed mobility and service management schemes. • Simulation to validate analytical results.

9. Contribution • Propose and analyze per-user regional registration schemes for integrated mobility and service management. • Given a set of parameters characterizing the operational and workload conditions of a MN, there exists an optimal regional area size for the MN such that the network communication cost is minimized. • Our scheme outperforms basic Mobile IPv6, Mobile IPv6 Regional Registration, and Hierarchical Mobile IPv6.

10. Network Layer Solutions (1) MIPv4 • An MN is identified by its home address. • If the MN is not in its home area, it has another address named Care of Address (CoA) associated with its current foreign location. • The Home Agent maintains a dynamic mapping between the home address and CoA. • A corresponding node always sends packets to the MN by the MN's home address. • Pros: transparent to mobile applications. • Cons: Triangle routing issue, CN HAFAMN , slow handover.

11. Network Layer Solutions (2) Mobile IP Regional Registration • Purpose: to reduce the location handoff overhead. • Moves within the regional registration area, MN only performs a regional registration to the GFA. • Moves to another regional area, MN will perform a home registration. • Packets path: CNHAGFAFAMN

12. Network Layer Solutions (3) MIPv6 • The MN determines its current location using the IPv6 router discovery protocol. • The MN uses the IPv6 address auto configuration mechanism to acquire a care of address (CoA) on the foreign link. • The MN notifies its home agent and CN for CoA change.

13. Compare MIPv6 with MIPv4

14. MAP MAP Hierarchical Mobile IPv6 (HMIPv6) HA Internet CN RCOA_2 AR RCOA_1 AR binding binding binding AR AR AR AR AP AP AP AR AR AP RCOA_1 LCOA’ AP AP Micro mobility RCOA_2 LCOA’’ Access network Access network Macro mobility RCOA_1 LCOA Mobility Anchor Point (MAP) http://www.ietf.org/rfc/rfc4140.txt

15. Application Layer Solutions Session Initiation Protocol (SIP) • An application layer protocol used to initiate, modify and terminate network sessions. • Four elements: users agents, registrars, proxy servers and redirect servers. • To support mobility. • SIP server in MN's home network receives registrations from the MN whenever the MN changes its location. • When the CN send an INVITE SIP message to the MN, the redirect server knows the current location information of the MN and forwards the INVITE message to the MN. • If a MN moves during an active session, it must send a new INVITE message to the CN using the same call ID. The new IP address is put in the contact field of the SIP messages. The CN will send future SIP messages to the new address. • If the MN is far away from the home network, every time it moves, it will send a new registration to the home SIP server. This may incur a high load.

16. Summary of the mobility support approaches

17. Service Management Approaches • Result Delivery Protocol (RDP) • Using a service proxy to provide reliable message delivery to MNs. Created when a MN initiates a new series of service requests. • Provide a fixed location for the reception of server replies, keep track of pending requests, store the request results, and forward the results to the MSS. • Runs on the application layer, suitable only for connectionless request-reply communications. • The proxy moves whenever the MN moves across a location boundary, may incur a high communication cost.

18. Service Management Approaches (continued) • Mobile service management schemes based on location-aware mobile service proxies in PCS. • The personal proxies work as intelligent client-side agents to communicate with services. • The proxies cooperate with location management system, it is location-aware and can optimally decide when and how often it should move with the roaming user. • Per-user integrated location and service management in PCS networks • A per-user service proxy is created to serve as a gateway between the mobile user and all client-server applications • The service proxy co-located with location database. • When there is a location handoff, a service handoff also happens to co-locate the service proxy with the location db. This allows the proxy to know the location of the mobile user to reduce the communication cost for service delivery.

19. Service Management Approaches (continued) • The above approaches are in the context of HLR/VLR based PCS networks, • MSS, VLR and HLR in PCS networks are powerful devices to perform both routing and computational functions. Routers in IP networks normally are specific routing devices. • PCS networks have regular shapes. IP subnets are shapeless. • Distance can be used to measure network cost in PCS. In IP networks, the network cost is normally measured by hops, which do not equal to distances.

20. Dynamic Mobility Anchor Points Scheme Assumption: access routers are restricted to perform network layer functions. Determine best DMAP domain size per MN dynamically according to its mobility and service characteristics to reduce network and signaling cost • Dynamic Mobility Anchor Points (Access routers chosen) for each MN • MN determines dynamically when and where to launch DMAP for minimizing network cost • DMAP domain size depends on MN’s mobility and service characteristics • HA and CN know MN by RCoA

21. DMAP (continued) • After service area is crossed, MN selects AR of subnet just crossed as DMAP: • MN determines size of new service area • Obtains RCoA & CoA from current subnet registers (RCoA,CoA) to current DMAP by binding request message • Inform HA and CN of new RCoA using standard Mipv6 • Packet delivery route: CN->DMAP->MN (tunneling or direct)

22. DMAP (continued) • MN’s service area - K, IP subnets • Goal : Dynamically determine optimal service area (K) per MN • Special case : • K is constant for all MN’s Degenerates to HMIPv6 • K is 1 Degenerates to MIPv6

23. Macromobility Diagram HA Internet CN RCOA_1 AR AR DMAP RCOA_2 DMAP binding binding tunneling Access network AR AR tunneling AR AP AP AP AP RCOA_1 LCOA’ RCOA_2 LCOA’’ Access network AP Micromobility RCOA_1 LCOA Dynamic Mobility Anchor Point (DMAP)

24. Trade-off • Large Service area : DMAP not change often • Communication cost for service data delivery high : CN->DMAP->MN • Location update cost is low • Small Service area : DMAP changed often • Communication cost for service data delivery low • Cost of informing HA and CN of DMAP change is high

25. Stochastic Petri Net Model

26. Service Cost • C i,service : Network communication overhead to service a data packet when MN in i th subnet in service area Delay from DMAP to the AR of the MN’s current subnet in the fixed network Delay between the DMAP and a CN in the fixed network Communication delay in the wireless link from the AR to the MN

27. Location Cost • C i,location : Network signaling overhead to service a location handoff when MN in i th subnet in service area • Clocation : Average communication cost to service a move operation by MN weighted by respective Pi probabilities i = K : Location + Service to inform HA and N CNs of RCoA change i < K : MN inform DMAP of CoA change

28. Total communication cost • Total communication cost per time unit •  : Data packet rate between MN and CNs •  : MN’s mobility rate

29. Comparing DMAP with Basic MIPv6 and HMIPv6 DMAP area large (mobility cost reduction) DMAP degenerates to HMIPv6 DMAP stays close to MN to avoid CN-DMAP-MN(service cost reduction) Degenerates to Basic MIPv6

30. Justify the assumption of F(K) Cost difference curves are not sensitive to form of F(k) Assumption of F(k) justified

31. IMSA: Integrated Mobility and Service Management Architecture Assumption: • Access routers are powerful and flexible. • Mobile proxies can be dynamically downloaded and roam the access routers to perform network layer and application layer functions on behalf of users and applications.

32. IMSA on Mobile IP v4 • A client-side proxy is created to serve as a GFA as in the MIP-RR to maintain the location information of the MN. • The proxy will communicate with the correspondent node on behalf of the MN. • The proxy will move only when the MN crosses a service area thus incurring a service handoff. • The service area size depends on the mobility and service characteristics of the MN. • Goal: network cost associated with mobility and service handoffs will be minimized.

33. Message Flow in IMSA-MIPv4

34. Service Handoff Process when Crossing a Service Area in IMSA-MIPv4

35. Performance Model for IMSA-MIPv4

36. Optimal Service Area Size Kopt with varying SMR and nct in IMSA There exists an optimal proxy service area size to minimize the overall communication cost when given a set of parameter values characterizing the mobility and service behaviors of the MN and the network conditions of the Mobile IP network.

37. Comparison of the IMSA-MIPv4 with Mobile IP v4. • The total cost increases with the increase of SMR for both schemes • Less communication overhead, especially pronounced when SMR is high.

38. Comparison of the IMSA-MIPv4 with MIP-RR with Route Optimization. • Total cost increases with the increase of either λor σ. • IMSA-MIPv4 incurs less communication overhead than MIP-RR, especially pronounced when λor σis high.

39. Optimal Service Area Size as a Function of nct • Initially increases. • Context transfer cost becomes high, stay in a large service area to avoid handoff. • The cost of context transfer would dominate the cost if nct is large.

40. Optimal Service Area Size as a Function of SMR • When SMR increases, Kopt decreases. • When SMR is small, the σis high compared to the λ; thus, the mobility management cost is larger than the service management cost. The proxy likes to stay at a larger service area to reduce the location handoff cost.

41. IMSA on Mobile IP v6 • IMSA-MIPv6 and the DMAP are similar. They differ only by the way of mapping a MN's RCoA to its CoA. • The DMAP design maps RCoA to CoA by having the current MAP maintain an internal table, so the MAP can intercept a packet destined for RCoA and forward it to the MN's CoA. • The IMSA-MIPv6 design maps RCoA to CoA by having a proxy run on the MAP directly receive a packet destined for RCoA, so the proxy can in turn forward the packet to the MN's CoA.

42. PICMM: Proxy-Based Integrated Cache Consistency and Mobility Management Scheme in Mobile IP Systems • Stateful cache consistency strategy: cache invalidation messages are asynchronously sent by the server the MN whenever data get updated. • A per-user proxy to buffer invalidation messages to reduce uplink requests when reconnected. • The proxy serves as a gateway foreign agent to keep track of the address of the MN in a region. • Identify the optimal regional area size to minimize the overall network traffic cost, due to cache consistency management, mobility management, and query requests/replies.

43. Cache invalidation strategies • Stateful strategy: • When there is an update to a data object, the server will send an invalidation message to those MNs that keep a cache copy. • Stateless strategy: • The server will broadcast information on data objects that have been updated either periodically or asynchronously. • Problem: if an MN misses invalidation reports while it is disconnected, it will have to discard the cache content after it reconnects.

44. The proxy’s three functions • Working as a GFA as in regional registration to keep tracking MN's location; • Acting as a service proxy for services engaged by the MN; • Allocating a buffer space to store service context information for each MN. The proxy will receive invalidation reports from the server on behalf of the MN. If the MN is connected, the proxy will forward them to the MN. If the MN is disconnected, the proxy will store them in the buffer. Once the MN is reconnected, the MN will get the latest invalidation reports from the proxy.

45. Integrated cache and mobility management scheme

46. Cache invalidation process

47. Query Process

48. Disconnection Support

49. Parameters • The on/off (or wake/sleep) behavior of the MN: while the MN is in a wake state, it will go to sleep with rate ωw, while the MN is in a sleep state, it will wake up with rateωs. • The residence time that the MN stays in a subnet while it is in a wake state. • Service traffic between the MN and server applications

50. Parameters