1. GrLS ： Group-Based Location Service in Mobile Ad Hoc Networks Hui Cheng, Jiannong Cao, Hsiao-Hwa Chen, and Hongke Zhang Department of Computing, Hong Kong Polytechnic University Department of Engineering Science, National Cheng Kung University College of Electronics and Information Engineering, Beijing Jiaotong University IEEE Transactions on Vehicular Technology, TVT 2008

2. Outline IntroductionGroup-Based Location Service(GrLS)Theoretical AnalysisPerformance EvaluationConclusion

3. Introduction With the progress of positioning techniques, mobile nodes can easily obtain their own locations. This has motivated a new type of routing method called geographic routing (also called location-based routing).

4. Introduction In geographic routing, nodes locally select next-hop nodes based on their neighborhood information and the destination’s location. S D

5. D Introduction In geographic routing, nodes locally select next-hop nodes based on their neighborhood information and the destination’s location. A challenging problem in geographic routing is how to provide location service so that a source node can obtain the location of the destination. S

6. Query Reply Introduction A number of location service protocols have been proposed. They can be divided into flooding-based and rendezvous-based approaches. S D

7. Introduction A number of location service protocols have been proposed. They can be divided into flooding-based and rendezvous-based approaches. S D Location server Update Query Reply

8. Introduction The rendezvous-based approach can further be divided into three types ： –Quorum based S D Update Query Reply

9. Introduction The rendezvous-based approach can further be divided into three types ： –Quorum based –Hierarchical based S D Update Query Reply

10. Introduction The rendezvous-based approach can further be divided into three types ： –Quorum based –Hierarchical based –Flat hashing based S D Home region Update Query Reply

11. Introduction These protocols have some drawbacks ： –The average length of update, query, and reply message is large. S D Source Destination Location server Home region Update Query Reply

12. Query Introduction These protocols have some drawbacks ： –The average length of update, query, and reply message is large. –No handoff of location information when the location server leave the location server region. Source Destination Location server Home region S D

13. Update Introduction These protocols have some drawbacks ： –The average length of update, query, and reply message is large. –No handoff of location information when the location server leave the location server region. –These protocols were not considered the hole. Source Destination Location server Home region S D Query

14. Introduction These protocols have some drawbacks ： –The average length of update, query, and reply message is large. –No handoff of location information when the location server leave the location server region. –These protocols were not considered the hole. –These protocols were not considered the group mobility. Source Destination Location server Home region

15. Goal Propose a location service protocol –Exploitation of group mobility to reduce the update overhead. –Reduce the average length of update, query, and reply message. –Provide a seamless handoff of location information. –Handle the hole.

16. Network Assumption Each node can get the location information of itself and all its neighbors. Each node have the same radio transmission range r.

17. Geographic Area PartitioningRecruiting Location ServersBasic Location ManagementGroup Location ManagementLocation Information HandoffHandling Empty Regions GrLS Protocol

18. GrLS - Geographic Area Partitioning Source Destination Location server Home region

19. GrLS - Geographic Area Partitioning Source Destination Location server Home region S D

20. GrLS - Geographic Area Partitioning Source Destination Location server Home region S D

21. GrLS - Geographic Area Partitioning R

22. R

23. HR 0 HR 1 HR 2 HR 3 HR 4 HR 5 HR 6 HR 7 HR 8 HR 9 HR 10 HR 11 HR 12 HR 13 HR 14 HR 15 HR 16 HR 17 HR 18 F(Node ID) → Home Region ID

24. GrLS - Recruiting Location Servers HR 0 HR 1 HR 2 HR 3 HR 4 HR 5 HR 6 HR 7 HR 8 HR 9 HR 10 HR 11 HR 12 HR 13 HR 14 HR 15 HR 16 HR 17 HR 18 F(Node ID) → Home Region ID

25. R R GrLS - Recruiting Location Servers

26. R One node All the node Some of the nodes

27. R GrLS - Recruiting Location Servers One node All the node Some of the nodes

28. R GrLS - Recruiting Location Servers r

29. R r r

30. R r r 1 5 15 19 26 32 4149 56 63 66 69 75

31. GrLS - Recruiting Location Servers 1 5 15 19 26 32 4149 56 63 66 69 75 Location server Home region Subregion 25

32. GrLS - Recruiting Location Servers Location server Home region Subregion 1 5 15 19 26 32 4149 56 63 66 69 75 25 Hops traversedTime spent Parallel Forwarding Sequential Forwarding Center-based Forwarding

33. GrLS - Recruiting Location Servers Location server Home region Subregion Hops traversedTime spent Parallel Forwarding Sequential Forwarding Center-based Forwarding Parallel Forwarding 92t2t

34. GrLS - Recruiting Location Servers Location server Home region Subregion Hops traversedTime spent Sequential Forwarding Center-based Forwarding Parallel Forwarding 92t2t Parallel Forwarding 92t2t Sequential Forwarding

35. GrLS - Recruiting Location Servers Location server Home region Subregion Hops traversedTime spent Center-based Forwarding Parallel Forwarding 92t2t Sequential Forwarding 66t6t

36. GrLS - Recruiting Location Servers Location server Home region Subregion Hops traversedTime spent Center-based Forwarding Parallel Forwarding 92t2t Sequential Forwarding 66t6t Sequential Forwarding 66t6t Center-based Forwarding

37. GrLS - Recruiting Location Servers Location server Home region Subregion Hops traversedTime spent Parallel Forwarding 92t2t Sequential Forwarding 66t6t Center-based Forwarding 62t2t

38. GrLS - Recruiting Location Servers Location server Home region Subregion Hops traversedTime spent Parallel Forwarding 92t2t Sequential Forwarding 66t6t Center-based Forwarding 62t2t 1 5 15 19 26 32 4149 56 63 66 69 75 25

39. GrLS - Recruiting Location Servers 1 5 15 19 26 32 4149 56 63 66 69 75 Location server Home region Subregion 25

40. GrLS - Basic Location Management 1 5 15 19 26 32 4149 56 63 66 69 75 25 Location Update – Time based – Distance based

41. GrLS - Basic Location Management Location Update – Time based – Distance based

42. GrLS - Basic Location Management Location Update – Time based – Distance based d d

43. GrLS - Basic Location Management Location Update t min - Minimum location update interval t max - Maximum location update interval d threshold - Distance threshold of location update Location Update – Time based – Distance based

44. GrLS - Basic Location Management Time Last location update t min t max d threshold tdtd t d < t min ： t min ≦ t d ≦ t max ： t max < t d ： Location Update t min - Minimum location update interval t max - Maximum location update interval d threshold - Distance threshold of location update not trigger the location update trigger the location update when reached t max, trigger the location update immediately

45. GrLS - Basic Location Management Source Destination Location server Home region Subregion Update

46. Query Reply GrLS - Basic Location Management Source Destination Location server Home region Subregion Data

47. Source Destination Location server Home region Subregion HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 GrLS - Group Location Management Data

48. HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5

49. GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2

50. GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2 Update Query(G) Reply Overview A{B, C, D, E, F, G}

51. Overview GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G Reply Group Initialization HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2

52. GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G Node A IDLocationTimeDistanceVelocity AlAlA tAtA 05 BlBlB tBtB ClClC tCtC DlDlD tDtD ElElE tEtE FlFlF tFtF GlGlG tGtG HlHlH tHtH H Group Initialization

53. GrLS - Group Location Management A B C D E F G Node A IDLocationTimeDistanceVelocity AlAlA tAtA 05 BlBlB tBtB ClClC tCtC DlDlD tDtD ElElE tEtE FlFlF tFtF GlGlG tGtG HlHlH tHtH Node A IDLocationTimeDistanceVelocity AlAlA tAtA 05 BlBlB tBtB 34 ClClC tCtC 35 DlDlD tDtD 36 ElElE tEtE 35 FlFlF tFtF 35 GlGlG tGtG 34 HlHlH tHtH 72 Conditions of Group Header ： Threshold of distance to l center. (ex. ≦ 2) Threshold of difference to v avg. (ex. v A ±0.5) H Node A IDLocationTimeDistanceVelocity AlAlA tAtA 05 BlBlB tBtB 34 ClClC tCtC 35 DlDlD tDtD 36 ElElE tEtE 35 FlFlF tFtF 35 GlGlG tGtG 34 HlHlH tHtH 72 Group Initialization Ignore the unsuitable nodes. (ex. v A ±1) The threshold of remain nodes ratio. (ex. 3/4) Node A IDLocationTimeDistanceVelocity AlAlA tAtA 05 BlBlB tBtB 34 ClClC tCtC 35 DlDlD tDtD 36 ElElE tEtE 35 FlFlF tFtF 35 GlGlG tGtG 34 l center v avg l A l center l center 4.857

54. Node A IDLocationTimeDistanceVelocity AlAlA tAtA 05 BlBlB tBtB 34 ClClC tCtC 35 DlDlD tDtD 36 ElElE tEtE 35 FlFlF tFtF 35 GlGlG tGtG 34 l center v avg GrLS - Group Location Management A B C D E F G Group Initialization H Conditions of Group Header ： Threshold of distance to l center. (ex. ≦ 2) Threshold of difference to v avg. (ex. v A ±0.5) Ignore the unsuitable nodes. (ex. v A ±1) The threshold of remain nodes ratio. (ex. 3/4) l A l center l center 4.857

55. Node A IDLocationTimeDistanceVelocity AlAlA tAtA 05 BlBlB tBtB 34 ClClC tCtC 35 DlDlD tDtD 36 ElElE tEtE 35 FlFlF tFtF 35 GlGlG tGtG 34 l center v avg GrLS - Group Location Management A B C D E F G Group Initialization H Conditions of Group Header ： Threshold of distance to l center. (ex. ≦ 2) Threshold of difference to v avg. (ex. v A ±0.5) Ignore the unsuitable nodes. (ex. v A ±1) The threshold of remain nodes ratio. (ex. 3/4) l A l center HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Group Header Group Member

56. GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G Group Header Group Member Group Initialization

57. GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G Group Header Group Member Group Initialization Group Maintenance Group Member Location Update t min - Minimum location update interval t max - Maximum location update interval d change – Relative location change threshold

58. Group Maintenance GrLS - Group Location Management A B C D E F G Group Header Group Member Group Member Location Update t min - Minimum location update interval t max - Maximum location update interval d change – Relative location change threshold Time Last location update t min t max l header l relative d change (x header, y header )(0,-3)0 3

59. Group Maintenance GrLS - Group Location Management A B C D F G Group Header Group Member Group Member Location Update t min - Minimum location update interval t max - Maximum location update interval d change – Relative location change threshold Time Last location update t min t max l header l relative d change (x header, y header )(0,-3)0 l header l relative d change (x header, y header )(4,-3)0 E 3 4 5 l header l relative d change (x header, y header )(4,-3)2

60. HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 l header l relative d change (x header, y header )(4,-3)2 Group Maintenance GrLS - Group Location Management Group Member Location Update t min - Minimum location update interval t max - Maximum location update interval d change – Relative location change threshold Time Last location update t min t max A B C D F G E A B C D E F G Location Service Handoff Group Header Group Member 3 4 5

61. GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2 Group Header Group Member Location Service Handoff Query(B) Single Node

62. GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2 Group Header Group Member Location Service Handoff Single Node

63. GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2 Group Header Group Member Location Service Handoff Single Node Single_to_Group(B) Single_to_Group(C) Single_to_Group(D) Single_to_Group(E) Query(B)

64. GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2 Group Header Group Member Location Service Handoff Single Node Group_to_Single(B) Group_to_Single(C) Group_to_Single(D) Group_to_Single(E) Query(B)

65. Reactive ID Update GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2 Group Header Group Member Location Service Handoff Query(B)

66. Reactive ID Update GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2 Group Header Group Member Location Server ID Server A’s location A{B, C, D, E, F, G}

67. Reactive ID Update GrLS - Group Location Management HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2 Group Header Group Member Location Server ID Server Query(B) A{B, C, D, E, F, G} Reply(B)

68. GrLS - Location Information Handoff HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G Group Header Group Member Location Server ID Server A{B, C, D, E, F, G} HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2 Reply(B)

69. GrLS - Location Information Handoff HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 A B C D E F G HR 0 HR 1 HR 6 HR 5 HR 4 HR 3 HR 2 Group Header Group Member Location Server ID Server A{B, C, D, E, F, G} Reply(B)

70. GrLS - Location Information Handoff 15 91317 212529 3337

71. GrLS - Location Information Handoff 15 91317 212529 3337 Group Header ： 24 Group Member ： {41, 42, 43, 44, 45} Location Server ID Server

72. GrLS - Location Information Handoff 5 91317 2129 3337 Group Header ： 24 Group Member ： {41, 42, 43, 44, 45} Location Server ID Server 1 25

73. GrLS - Handling Empty Regions Group Header ： 24 Group Member ： {41, 42, 43, 44, 45} Location Server ID Server 5 91317 2129 3337 Part-Update Entire-Update Part-Query Entire-Query

74. GrLS - Handling Empty Regions Empty Subregion Part-Update Entire-Update Part-Query Entire-Query

75. GrLS - Handling Empty Regions Empty Subregion Part-Update Entire-Update Part-Query Entire-Query

76. GrLS - Handling Empty Regions Empty Subregion Part-Update Entire-Update Part-Query Entire-Query

77. GrLS - Handling Empty Regions Empty Subregion Part-Update Entire-Update Part-Query Entire-Query Query node

78. GrLS - Handling Empty Regions Empty Subregion Part-Update Entire-Update Part-Query Entire-Query Query node

79. GrLS - Handling Empty Regions Empty Subregion Part-Update Entire-Update Part-Query Entire-Query Query node

80. GrLS - Handling Empty Regions Empty Subregion Part-Update Entire-Update Part-Query Entire-Query Query node

81. GrLS - Handling Empty Regions Empty Home Region Part-Update Entire-Update Part-Query Entire-Query HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5

82. HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 GrLS - Handling Empty Regions Empty Home Region Part-Update Entire-Update Part-Query Entire-Query Update node

83. HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 GrLS - Handling Empty Regions Empty Home Region Part-Update Entire-Update Part-Query Entire-Query Update node

84. HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 GrLS - Handling Empty Regions Empty Home Region Part-Update Entire-Update Part-Query Entire-Query Update Query node

85. HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 GrLS - Handling Empty Regions Empty Home Region Part-Update Entire-Update Part-Query Entire-Query Query node

86. GrLS - Theoretical Analysis HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Empty Home Region Entire-Query Query node HR 7 HR 13 HR 8 HR 12 HR 9 HR 10 HR 11 HR 16 HR 17 HR 15 HR 18 HR 14 HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Without Group Location Management With Group Location Management

87. GrLS - Theoretical Analysis Notations used in the analysis NNumber of nodes in the network T loc_upd_max Maximum location update interval T net_time Network lifetime L upd Average location update path length L que Average location query path length L rep Average location reply path length gAverage group size nNumber of groups n que Number of location queries Without Group Location Management With Group Location Management HR 7 HR 13 HR 8 HR 12 HR 9 HR 10 HR 11 HR 16 HR 17 HR 15 HR 18 HR 14 HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5

88. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management HR 7 HR 13 HR 8 HR 12 HR 9 HR 10 HR 11 HR 16 HR 17 HR 15 HR 18 HR 14 HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Update’= Query’= n que × L que

89. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management HR 7 HR 13 HR 8 HR 12 HR 9 HR 10 HR 11 HR 16 HR 17 HR 15 HR 18 HR 14 HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Update’= Query’= n que × L que Group Header Update =

90. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management HR 7 HR 13 HR 8 HR 12 HR 9 HR 10 HR 11 HR 16 HR 17 HR 15 HR 18 HR 14 HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Group Header Update = Query length for group node =

91. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management HR 7 HR 13 HR 8 HR 12 HR 9 HR 10 HR 11 HR 16 HR 17 HR 15 HR 18 HR 14 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Group Header Update = Query length for group node = R R/2 Query node

92. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management HR 7 HR 13 HR 8 HR 12 HR 9 HR 10 HR 11 HR 16 HR 17 HR 15 HR 18 HR 14 HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Group Header Update = Query length for group node = Query node L que

93. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management Group Header Update = Query length for group node = Query node L que R

94. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management HR 7 HR 13 HR 8 HR 12 HR 9 HR 10 HR 11 HR 16 HR 17 HR 15 HR 18 HR 14 HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Update = Query length for group node = Group Header Query node L que +6.8 L que +6.8 Query = R

95. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management HR 7 HR 13 HR 8 HR 12 HR 9 HR 10 HR 11 HR 16 HR 17 HR 15 HR 18 HR 14 HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Update = Query length for group node =L que +6.8 Query = Group node Single node

96. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management HR 7 HR 13 HR 8 HR 12 HR 9 HR 10 HR 11 HR 16 HR 17 HR 15 HR 18 HR 14 HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Update = Query length for group node =L que +6.8 Query = Group node Single node

97. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management HR 7 HR 13 HR 8 HR 12 HR 9 HR 10 HR 11 HR 16 HR 17 HR 15 HR 18 HR 14 HR 0 HR 1 HR 4 HR 2 HR 3 HR 6 HR 5 Update = Query length for group node =L que +6.8 Query = The reduction overhead=(Update’+Query’) - (Update+Query)

98. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management The reduction overhead=(Update’+Query’) - (Update+Query)

99. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management The reduction overhead=(Update’+Query’) - (Update+Query) Since n << ng

100. GrLS - Theoretical Analysis Without Group Location Management With Group Location Management The reduction overhead=(Update’+Query’) - (Update+Query) Since n << ng

101. Performance Evaluation Simulation Parameters SimulatorGloMoSim 2.03 Speed Range1~20 m/sec (3.6~72 km/hr) Transmission Range250 m MAC ProtocolIEEE 802.11 DCF Mobility ModelRandom Network ModelQuasi static [1~5 m/sec (3.6~18 km/hr)] Mobile [5~20 m/sec (18~72 km/hr)] Simulation Time900 sec Simulation Area3 km × 3 km

102. Performance Evaluation 3 km

103. Performance Evaluation GrLS Parameters Update Threshold125 m Minimum Update Interval12.5 sec Maximum Update Interval40 sec

104. Performance Evaluation Load Balance 0 0 1 1 4 4 2 2 3 3 6 6 5 5

105. Comparison GrLS GrLS- Grid Location Service (GLS) Performance Evaluation

107. Overhead – Quasi static 450 nodes900 nodes

108. Performance Evaluation Overhead – Mobile 450 nodes900 nodes

109. Performance Evaluation Average query hop length Quasi staticMobile

110. Performance Evaluation Query success ratio Quasi staticMobile

111. Conclusion Propose a location service protocol –Exploitation of group mobility to reduce the update overhead. –Improve the success of query. –Reduce the average length of update, query, and reply message. –Provide a seamless handoff of location information. –Handle the hole.