Fault Tolerant Multi-path Enhanced Routing Algorithm

1. Fault Tolerant Multi-path Enhanced Routing Algorithm I-Shyan Hwang, Cheng-Ching Yeh Chiung-Ying Department of Computer Engineer and Science Yuan-Ze University Department of Information Management Transworld Institute of Technology

2. Outline • Introduction • Fault Tolerant Multi-path Enhanced Routing Algorithm • Performance Evaluation • Conclusion

3. Introduction • The link stability-base method uses GPS to determine the host’s position and speed of motion • The loading balance routing method evaluate the number of routing paths • As in multi-path routing method, the selection of a multi routing path is based on AP(active path) records

4. Fault Tolerant Multi-path Enhanced Routing Algorithm • route discovery • Check routing table • maintenance procedure • prevents breaking paths

5. Receiving RREQ Update information table 2 1 Broadcast RREQ Hop count>MAX_ Hop Yes Discard RREQ No Insert information of host into PreRouteReply If destination host have been in routing table No 2 No Existing the same information in routing table No Yes If the record have been in PreRouteReply Yes If the serial number of destination in routing table larger than control record ones No No If routing process have proceed with this node 2 Yes If the control packet record and PreRouteReply record better than old ones Yes Yes 1 No Proceed Route Reply process Yes At most three records in PreRouteReply with priority Modify priority of records in PreRouteReply

6. Max_Hop=(int(Er/Tr)+1)*2 • Er :environment range • Tr : transmission range • The intermediate host only receives RREQ once to prevent two hosts from forwarding RREQ to each other RREP table RREQ table

7. Priority • At most three RREQs are accepted • Priority( stored in PreRouteReply table): • First receive priority 1 • Hop count<priority 1,Min(TTL)>priority 1,Tot(TTL)>priority 1,MAP< priority 1, set priority 1 • Only one record, set priority 2 • Hop count<priority 2,Min(TTL)>priority 2,Tot(TTL)>priority 2, set 2 • No one is priority 3, set 3 • Hop count<priority 3,Min(TTL)>priority 3,Tot(TTL)>priority 3,MAP< priority 3, set 2

8. RREP scheme • The destination node with the updatest routing table received RREQ • Waiting for destination node received 3 RREQs • Flooding RREP along primary and backup path • Return pass RREP to pre-node of PreRouteReply record • Update PreRouteReply record into routing table

9. Route maintenance • The route maintenance prevents unexpected factors from breaking paths. • If a host’s path is broken, then the host will search an alternate path from its routing table and send back an error message to previous host until the source claims the path is invalid. • If an alternate path does not exist, then the RREQ will be transmitted to destination host.

10. Performance Evaluation • Environment range : 1Km*1Km • Number of hosts : 300 • Bandwidth : 2Mbps • Transmission range : 100,200,400m • Speed • Uniformly distributed between form 0~20m/sec • Fixed speeds :1,5,10,15,20,25m/sec

11. Performance Evaluation • Maximum active paths • The DSR algorithm has more active paths than the proposed algorithm • Number of Re-Routes • The proposed algorithm has the lower number of re-routes than the DSR algorithm

12. Performance Evaluation • Hop Counts • The proposed algorithm has a higher number of hop counts than DSR algorithm • Mean throughput • The proposed algorithm has better mean throughput than the DSR algorithm

13. Conclusion • Provide stable routing path and better throughput • Improve the system performance than the DSR algorithm