GLR: A Novel Geographic Routing Scheme for Large Wireless Ad Hoc Networks

1. GLR: A Novel Geographic Routing Scheme for Large Wireless Ad Hoc Networks Jongkeun Na, Chong-kwon Kim School of Computer Science and Engineering, Seoul National University Computer network 2006

2. Outline • Introduction • Geographic Landmark Routing (GLR) • Protocol Overhead • Performance Evaluation • Conclusion

3. Introduction • Passive Protocols • Obstacle handling rules are triggered when data packets encounter the obstacle • Active Protocols • Obstacles are handled actively before packet routings • Proactively updating and maintaining obstacle information is not suitable to dynamic topology

4. Introduction • The blind detouringproblem d d b Obstacle c Obstacle c a a Dead-end node s s

5. Introduction • The triangular routingproblem d d b Obstacle c Obstacle c a a Dead-end node s s

6. Motivations and Goals • Motivations • Solve the blind detouring and triangular routing problems • Guide the packet along an efficient route • Goals • Reduce path length • Increase packet delivery ratio

7. Assumptions • Each node is aware of its location and the neighbors’ location • The source node can determine the location of the destination node

8. Geographic landmark routing (GLR) • Landmark discovery d e Landmark c Landmark b Obstacle a Greedy Routing Perimeter Routing s Dead-end node

9. Geographic landmark routing (GLR) • Landmark routing d e Landmark c Obstacle a Greedy Routing s Dead-end node

10. Case 3 d Landmark Obstacle s Case 2 Case 4 d d Landmark Virtual Landmark Obstacle Obstacle s s Geographic landmark routing (GLR) • Various cases Case 1 d Obstacle s

11. d 9 b Obstacle c 8 s Geographic landmark routing (GLR) • Disadvantage • GLR may not find the shortest path d 10 b Obstacle c 10 Dead-end node s Landmark

12. d f Obstacle 1 e c Obstacle 2 b s Geographic landmark routing (GLR) • Multi-obstacle • GLR can find the better route • GLR may not find the shortest path d f Obstacle 1 e c Obstacle 2 b Landmark s

13. Landmark b Geographic landmark routing (GLR) • When a landmark node is unavailable • the previous node selects the next intermediate target through dynamic self-determination • Landmark discovery is periodically executed d d Obstacle 1 Landmark e Landmark c Obstacle i Obstacle 2 j s s

14. the averaged cost for FLD/BLD message exchange the average cost for feedback Protocol overhead • The total number des.of node i: mi = oi + ri # des. of node i serving as a source # des. of node i serving as a landmark

15. Performance evaluation • Simulator: ns 2 • 1500x1000 m2 • Communication range: 250 m • Tx=1.6W Rx=1.2W and Idle=1.15W • Each hole is represented as a circle with a diameter 250m • 95% confidence interval

16. Performance evaluation Node degree Node degree Static network with hole effect, h = 0

17. Performance evaluation Node degree Static network with hole effect, h = 0

18. Performance evaluation • On sparse topologies, node degree = 5 The optimality of path length in GPSR and GLR

19. Performance evaluation • Mobile nodes follow the random waypoint model with maximum speed 20 m/s Pause time (s) Pause time (s) mobile networks with hole effect, h = 6

20. Performance evaluation mobile networks with hole effect, h = 6

21. Conclusion • GLR can • Solve the blind detouring and triangular routing problems • Reduce the path length • be used for any geographic routing protocols

22. Thank you