1. Impact of Selfish Nodes on Route Discovery in Mobile Ad Hoc Networks Impact of Selfish Nodes on Route Discovery in Mobile Ad Hoc Networks Qi Zhang and Dharma P. Agrawal IEEE conference on Globecom ’ 04 Speak:His-wei Chen

2. Outline Outline  INTRODUCTION  ROUTING WITH SELFISH NODES  Simulation  CONCLUSION

3. INTRODUCTION INTRODUCTION  reduce the route discovery cost by minimizing the number of rebroadcasts, collisions,contention. collisions,contention.  Reduce forward packet in RREQ of AODV  Goal: Discover and maintain low cost appropriate paths in dynamic environments.

4. Two type node Two type node  selfish nodes: refuse to relay packets  normal nodes: always relay packets. AODV protocol: all node relay packets

5. ROUTING WITH SELFISH NODES P= P=

6. ROUTING WITH SELFISH NODES T: 時間 (Number of route request messages)

7. ROUTING WITH SELFISH NODES  假設 data packet size :K bytes  Control packet size : bytes : Total number of forwarded route requests

8. ROUTING WITH SELFISH NODES ROUTING WITH SELFISH NODES G:goodput

9. ROUTING WITH SELFISH NODES Protocol: Protocol: 計算 the probability range Randomly choose the selfish probability p within the range Determine if the current node should be selfish or not based on the probability p.

10. ROUTING WITH SELFISH NODES  所有參數設定好之後 : If the current node is not selfish Reboradcast the packet Reboradcast the packetElse Discard the packet Discard the packet

11. Simulation Simulation

12. Rebroadcast time AODV RSN(p=0.1) RSN(p=0.2)

13. Simulation Simulation Collision time

14. Simulation Simulation Latency time

15. Simulation Simulation Throughput time

16. Simulation Simulation Reachability time

17. CONCLUSION CONCLUSION  mobile nodes into selfish nodes and normal nodes.  selfish nodes:refuse to relay packets  normal nodes: always relay packets.  Simulation results show outperforms the AODV protocol: low Rebroadcasts, low Collision, low Latency, high Throughput, high Reachability