2. 0 Routing in Mobile Networks Professor Ching-Chi Hsu Part I. Mobile IP on Network Layer Part II. Routing in Mobile/Wireless Ad-hoc Networks

3. 1 Mobile IP on Network Layer  DNS based Name to Address resolution  Network Layer Mobility Problem  Illustration of Terms in Mobile IP  Two Tier Addressing  Mobile IP Architecture Components  Address Translation Mechanisms  Mobile IP Proposals

4. 2 DNS based Name to Address resolution

5. 3 Network Layer Mobility Problem Directory Service View  DNS didn’t handle dynamic updates.  DNS design attempts to optimize the access cost, and not the update cost.  There is no call back mechanism generally available from servers to clients in case the cached entries of the DNS clients become invalid.

6. 4 Network Layer Mobility Problem Internet View TCP connection:  If the mobile host acquires a new IP address, all TCP connections involving the mobile host will be broken.  If the mobile host retains its address, then the routing system cannot forward packets to its new locations.

7. 5 Illustration of Terms in Mobile IP

8. 6 Two Tier Addressing

9. 7 Mobile IP Architecture Components

10. 8 Address Translation Mechanisms Encapsulation

11. 9 Address Translation Mechanisms Loose Source Routing

12. 10 Mobile IP Proposals Columbia Scheme

13. 11 Mobile IP Proposals Sony Scheme

14. 12 Mobile IP Proposals LSR Scheme

15. 13 Mobile IP Proposals IETF Scheme

16. 14 Routing in Mobile/Wireless Ad-Hoc Networks  Introduction  Definitions of Dynamic Groups Routing  Dynamic Groups Routing Algorithms  Simulation and Analysis  Conclusion  Future Works

17. 15 Introduction  Ad-Hoc Networks Model  Previous Works on Routing in Ad-Hoc Networks  Motivations of Dynamic Groups Routing

18. 16 Ad-Hoc Networks Model  Ad-hoc networks  Wireless communication  Without fixed network interaction and centralized administration.  Multi-hop routing style with no cheating of the forwarding nodes mobile host routing

19. 17 Ad-Hoc Networks Model  Why ad-hoc networks ?  When the access base station are not set up due to low cost effect, poor performance or low usage  Ad-hoc networks may be the extension of base stations  Applications of ad-hoc networks  An outdoor conference  Emergency situations of natural disasters  Military deploys in battlefield Ad-hoc networks Base station Bridges

20. 18 Previous Works on Routing in Ad-Hoc Networks  On-demand dynamic source routing (D.B.Johnson et al.)  Cluster-based routing (P. Krishna et al.)  Zone routing (Z.J. Haas et al.)  Minimum connected dominating set routing (B. Das et al.)

21. 19 On-demand dynamic source routing  Loosely source routing while route requested  Each node may overhear the routing information from the neighbor nodes.  Example: source routing and overhearing source destination Route request message Route reply message Overhearing range Mobile node

22. 20 Cluster-based routing  The clustering method depends on the k-hop mutually reachable relation between any two nodes in a cluster.  A two-level network graph - cluster-level + node-level  Example: 1-cluster(fully connected sub-graphs as clusters) Mobile node Cluster

23. 21 Zone routing  Zone - the nodes within the defined radius  Radius - hop-count reachable from the central node  Each node maintain the topology in its zone  Example: zone with radius = 2 Mobile node Zone

24. 22 Minimum connected dominating set routing  Minimum connected dominating set (MCDS) - construct a so-called virtual backbone in an ad-hoc network.  Routing through the virtual backbone by dominators.  Example: virtual backbone construction MCDS edge Non-MCDS edge MCDS(virtual backbone) Mobile node dominators

25. 23 Comparison Routing methodsAdvantagesDisadvantages Zone Routing (cluster-based) MCDS Routing Infrastructure Uniform cluster with the node as the center MCDS virtual backbone as routing trunk Easy to maintain the topology in zones Frequent moving causing heavy topology update On-demand Routing Only sense the neighbors Less overhead to maintain topology Frequent routing make it mass route discovery overhead Simple to search routes by virtual backbone Network grown up make the virtual backbone a heavy burden

26. 24 Motivations of Dynamic Groups Routing  Ad-hoc network topology maintenance  Range Consideration  The whole network - inefficient and infeasible.  Only neighbors - inefficient while frequent route requesting  Structure Consideration  Relative conectivity  Relative position  To propose an easy topology maintenance and good traffic isolation ad-hoc network routing system- Dynamic Groups Routing

27. 25 Definitions of Dynamic Groups Routing  Illustration of an ad-hoc network construction  Definitions  Dominating value definition  Routing groups definitions  Definitions of attachable sets, bridge and peripheral clusters

28. 26 Illustration of an ad-hoc network construction D B HC R IE A JFG Q P O M N K L Routing group Positive cluster Non-positive cluster

29. 27 Dominating value definition  Definition 1: DV(p) is the dominating value of a node p in an ad-hoc network. It is calculated as the following before the construction proceeds. Initial DV(p) := 0 For each q which q in neighborhood of p If deg(p) > deg(q) then DV(p) := DV(p) +1 else if deg(p) < deg(q) DV(p) := DV(p) – 1  Theorem 1: In the initial constructed bi-directional connected network, the summation of all dominating values of nodes is zero.

30. 28 Routing groups definitions  Definition 2: A node p is positive while DV(p) > 0, otherwise non-positive.  Definition 3: In a constructed ad-hoc network, the cluster formed by all connected positive nodes is called positive cluster (P-cluster). The cluster formed by all connected non- positive nodes is called non-positive cluster (N-cluster).  Definition 4: A routing group (RG) is formed by one P- cluster with its adjacent N-clusters

31. 29 Definitions of attachable sets, bridge and peripheral clusters  Definition 4: An attachable set is a set of all the positive nodes in the same P-cluster with direct bi-directional links to the same adjacent N-cluster  Definition 5: A bridge cluster is the N-cluster belonged to more than one RG. On the other hand, the N-cluster belonged to one RG is called peripheral cluster.

32. 30 Dynamic Groups Routing Algorithms  Construction algorithm  Route discovery strategy  Route maintenance  Connection recovery

33. 31 Message propagating illustration in construction D B HC R IE A JFG Q P O M N K L Note: Nlist(A),DV(A)

34. 32 Construction algorithm {For each mobile node p in the ad-hoc network} Broadcast message deg(p) to all neighbors Receive message deg(q) from each neighbor q Calculate DV(p) as definition 1 Broadcast message {List(N(p)),DV(p)} to each neighbor q Receive message {List(N(r)),DV(r)} from each neighbor q For each message {List(N(r)),DV(r)} Case 1. DV(p) > 0 & DV(q) > 0 Propagate it to all positive neighbors excluding q Case 2. DV(p) > 0 & DV(q) <= 0 Propagate it to all positive neighbors Case 3. DV(p) <= 0 & DV(q) <= 0 Propagate to all neighbors excluding q Case 4. DV(p) 0 Ignore the message

35. 33 Route discovery illustration  S Intra-cluster Intra-group Inter-group RG P-cluster N-cluster Mobile node Intra-clusterInter-groupIntra-group

36. 34 Route discovery strategy For a route request from the source node s to the destination node d if (the node s is non-positive) then it checks the local topology information of its N-cluster if (the destination node d is found) then it routes from the node s to the node d directly else it multicasts intra-group route request message to all the nodes in its attachable sets and waits for reply message if (all the reply message are failure) then it issues inter-group route request message to all the nodes in its attachable sets else it routes by the reply information from one of the nodes in its attachable sets else it checks the local topology information of its routing group if (the destination node d is found) then it routes from the node s to the node d directly else it multicasts inter-group route request message to all the nodes in the attachable sets of all its bridge clusters,which also belong to other routing groups

37. 35 Route maintenance (link variations) HmHn  6 kinds of reactions to the variations Reacting/Interacting node Interacting/Reacting node Link N/P Connected/Disconnected 2*2*2= 8

38. 36 Route maintenance (link variations)

39. 37 Route maintenance ( connectivity dominating variations) DV(E): +2 DE I H G F C A B

40. 38 Route maintenance ( connectivity dominating variations)

41. 39 Route maintenance ( connectivity dominating variations)

42. 40 Connection Recovery  Group-level backtracking to the last one P-cluster N-cluster New route RG1RG2

43. 41 Connection Recovery

44. 42 Simulations and Analysis  Simulation model  Simulation results

45. 43 Simulation model  N mobile nodes move randomly in a square area

46. 44 Simulation results  Connectionless  Variant number of mobile hosts  Variant moving frequency of mobile hosts  Variant route query frequency of mobile hosts  Connection-oriented  32 mobile hosts in 800m*800m area  72 mobile hosts in 1200m*1200m area

47. 45 Total delay in route maintenance phase by increasing number of mobile hosts

48. 46 Control traffic in route maintenance phase by increasing number of mobile hosts

49. 47 Control traffic in route discovery phase by increasing number of mobile hosts

50. 48 Total control traffic by increasing number of mobile hosts

51. 49 Total delay in route maintenance phase by increasing moving frequency

52. 50 Control traffic in route maintenance phase by increasing moving frequency

53. 51 Control traffic in route discovery phase by increasing moving frequency

54. 52 Total control traffic by increasing moving frequency

55. 53 Total delay in route maintenance phase by increasing routing frequency

56. 54 Control traffic in route maintenance phase by increasing routing frequency

57. 55 Control traffic in route discovery phase by increasing routing frequency

58. 56 Total control traffic by increasing routing frequency

59. 57 The message complexity comparison by connection time duration with area = 800m*800m, number of mobile nodes = 32, moving frequency =50%

60. 58 The message complexity comparison by mobile node moving frequency with area = 800m*800m, number of mobile nodes = 32, connection duration = 50

61. 59 The message complexity comparison by connection time duration with area = 1200m*1200m, number of mobile nodes = 72, moving frequency =50%

62. 60 The message complexity comparison by mobile node moving frequency with area = 1200m*1200m, number of mobile nodes = 72, connection duration = 50

63. 61 Conclusion  A two-type cluster scheme is proposed to form the routing groups structure, easily maintaining the routing environment in ad–hoc networks.  It seems that this approach is adaptive to such domain for reducing the control message propagation in ad-hoc networks  Upon the basic constructed model of ad-hoc networks, the route recovery method is developed for connection-oriented applications

64. 62 Future Works  Now a day many multicasting applications are applied in mobile/wireless ad-hoc networks.  The next research subject is developing efficient multicast routing methods in ad-hoc networks based on the constructed dynamic groups model.