Jim Parker CMSC691t Spring 2000 “Ad-hoc On-Demand Distance Vector Routing” A dynamic routing algorithm for mobile ad-hoc networks

Jim Parker CMSC691t Spring 2000 AODV Characteristics On-demand routing Symmetric links Distance vector algorithm Route table

Jim Parker CMSC691t Spring 2000 Goals Discovery only when necessary Distinguish between neighborhood detection and route maintenance Disseminate change information to those neighbors most likely to be in need

Jim Parker CMSC691t Spring 2000 Path Discovery Broadcast RREQ – –Unique Path Setup –Reverse –Forward

Jim Parker CMSC691t Spring 2000 Reverse Path Setup src_seq_# dest_seq_# Reverse path Timeout D S

Jim Parker CMSC691t Spring 2000 Forward Path Setup Bi-directional link? Route current? –Unicast back to neighbor RREP – D S

Jim Parker CMSC691t Spring 2000 Forward Path Setup Each node on path –forward pointer –updates timeout –records dest_seq_# Nodes not on path timeout Propagate first, then only new information D S

Jim Parker CMSC691t Spring 2000 Route Table Destination Next Hop Number of hobs (metric) Sequence number for the destination Active neighbors for this route Expiration time for the route table entry

Jim Parker CMSC691t Spring 2000 Path Maintenance Link failure –Timeout on ‘Hello’ –Packet forwarding error Unsolicited RREP –Propagates to active path members –Fresh sequence number –Hop count is infinity Path repair via RREQ

Jim Parker CMSC691t Spring 2000 Local Connectivity ‘Hello’ message –Identity –Sequence Number –Neighbors heard –TTL = 1 hello_interval allowed_hello_loss

Jim Parker CMSC691t Spring 2000 Local Connectivity rreq_retries Bi-directional connectivity Inactive neighbors

Jim Parker CMSC691t Spring 2000 Simulation Results Number of nodes set to 50, 100, 500, and 1000 Voice and data traffic allowed_hello_loss and rreq_retries determined to be optimal at 2 Scalable

Jim Parker CMSC691t Spring 2000 Current Status AODV submitted as an Internet Draft Multicast Intermediate node route rebuilding Goodbye ‘Hello’? Locality of association and QoS –delay –bandwidth assurances

Jim Parker CMSC691t Spring 2000 Conclusions Longer route establishment latency But... Intermediate node route return Immediate report of link outage Stale routes aged out

Jim Parker CMSC691t Spring 2000 Comparison “A Performance Comparison of Multi-Hop Wireless Ad Hoc Network Routing Protocols” –DSDV, TORA, DSR, AODV –Conclusion: “DSR Rules!” “Performance Comparison of Two On-demand Routing Protocols for Ad Hoc Networks” –DSR, AODV –Delay and throughput DSR better for low loads AODV better for high loads

Jim Parker CMSC691t Spring 2000 References Charles E. Perkins and Elizabeth M. Royer. “Ad-hoc On-Demand Distance Vector Routing.” Proceedings of the 2nd IEEE Workshop on Mobile Computing Systems and Applications, New Orleans, LA, February 1999, pp Charles E. Perkins, Elizabeth M. Royer, and Samir R. Das. “Ad-hoc On- Demand Distance Vector Routing.” IETF Internet Draft, draft-ietf-manet- aodv-05.txt, March 2000 (Work in Progress). J. Broch, D. Maltz, D. Johnson, Y. Hu, and J. Jetcheva. “A Performance Comparison of Multi-Hop Wireless Ad Hoc Network Routing Protocols.” Proceedings of the Fourth Annual ACM/IEEE International Conference on Mobile Computing and Networking (MobiCom'98) Samir R. Das, Charles E. Perkins, and Elizabeth M. Royer. “Performance Comparison of Two On-demand Routing Protocols for Ad Hoc Networks.” Proceedings of the IEEE Conference on Computer Communications (INFOCOM), Tel Aviv, Israel, March 2000, p