1. SHARP: A Hybrid Adaptive Routing Protocol for Mobile Ad Hoc Networks Venugopalan Ramasubramanian, Zygmunt J. Haas, and Emin Gun sirer ACM MobiHoc 2003 Speaker ： ChiChih Wu

2. Outline Introduction Overview of SHARP SHARP Routing Protocols Simulations Conclusions

3. Introduction Ad hoc routing protocols –Proactive protocols DSDV –Reactive protocols AODV TORA –Hybrid protocols

4. Introduction Proactive protocols –Advantage good reliability Low latency through frequent dissemination of routing information –Disadvantage high overhead

5. Introduction Reactive protocols –Advantage Low routing overhead –Disadvantage Increase latency due to on-demand route discovery and route maintenance

6. Overview of SHARP SHARP Routing Protocol –Proactive Zone –All nodes not in the proactive zone use reactive routing protocols to establish routes to that node –Making some nodes more popular than others

7. Overview of SHARP Proactive Zone Reactive Routing Protocol

8. Overview of SHARP Proactive Zone –By increasing the radius, SHARP can decrease the loss rate and variance in delay, but will pay more in packet overhead to maintain routes in a large zone –By decreasing the radius, SHARP can reduce routing overhead, as fewer nodes need to be proactively updated; however, it may pay more in delay jitter and experience higher loss rates

9. SHARP Routing Protocols Proactive Routing Component –Destination Sequenced Distance Vector (DSDV) –Temporally Ordered Routing Algorithm (TORA) Reactive Routing Component –Ad-hoc On-demand Distance Vector (AODV)

10. SHARP Routing Protocols DSDV –Table driven destnextmetric … AA0 BB1 CB2 destnextmetric … AA1 BB0 CB1 ACB destnextmetric … AB2 BB1 CC0

11. SHARP Routing Protocols TORA s d 3 3 2 2 2 1 1 0 s d height

12. SHARP Routing Protocols

13. TORA s d

14. SHARP Routing Protocols Proactive Routing Component –Building and maintaining a directed acyclic graph (DAG ) rooted at the destination

15. SHARP Routing Protocols Reactive Routing Protocols d s s d d s s d Source Destination

16. Simulations 600 nodes –3000m X 3000m –8 packets per second –256 bytes per packet 200 nodes –1700m X 1700m –2 packets per second –256 bytes per packet Velocities ranged between 0 m/s and 20 m/s

17. Simulations Mobility fraction

18. Simulations

19. Simulations

20. Simulations

21. Conclusions SHARP could be used to minimize packet overhead, to bound loss rate, and to control delay jitter SHARP achieves performance that is better than each one of its concomitant purely reactive and purely proactive protocols across a wide range of network conditions

22. THANK YOU