Based On The Hop Count To Improve AODV Routing Protocol

Ad hoc on demand distance vector routing protocol named AODV is a reactive routing protocol, and it has been widely used. However, the AODV needs the upstream node or source node to find a new routing path to the destination node when the link interrupted, which will result in larger delay. So the repair strategy of AODV is a key to affect its performance.After analyzes the whole process of AODV Routing Protocol in detail, this paper proposes a modified routing protocol named HAODV to improve the AODV Routing Protocol. Focusing on the AODV routing repair strategy and based on the hop count on the base path and the destination node, HAODV maintenances a repair area around the base path within certain number of hops. Those nodes who are in the repair area will receive the packets from the destination node to know the routing path to reach the destination node. Because in certain period of time, the mobile node is not too far away, if the link is interrupted, the path can be repaired effectively in the area.In order to form and maintain the repair area and to optimize the repair strategy of AODV, HAODV adds a table to record the hop count of base path, HAODV adds and modifies corresponding packets. Then the paper makes a detailed analysis and design on HAODV s whole routing protocol process in route discovery and route maintenance. The HAODV routing protocol algorithm is implemented in GloMoSim simulation platform. Then it is compared with the traditional AODV routing protocol in data distribution rate, average delay and the routing hops. Simulation results show that HAODV is higher than the AODV in packet delivery ratio, less than in the average delay and less than in the path hop count.