AODV with Source Route Accumulation for improved Routing in WiMAX

Worldwide Interoperability for Microwave Access (WiMAX) is a technology that bridges the gap between fixed and mobile access and offer the same subscriber experience for fixed and mobile user. Routing protocols for WiMAX mobile ad-hoc networks have to face the challenge of frequently changing topology, low transmission power, asymmetric links and mainly overhead problems. Ad-hoc on Demand Distance Vector (AODV) is one of the widely used routing protocols. In this paper Source Route path Accumulation Approach (SRA) is proposed for improving the performance of Ad hoc On Demand Routing Protocol (AODV) to overcome the problems of delay and overhead up to a large extent as comparison to basic AODV protocols. The protocol, AODV-SRA, incorporates source route path accumulation during the route discovery process in AODV to attain extra routing information. In this approach when the RREQ and RREP messages are generated or forwarded by the nodes in the network, each node appends its own address on these route discovery messages. Hence, at any point the RREQ packet contains a list of all the nodes traversed. Each node also updates its routing table with all the information contained in the control messages. The performance of AODV with modified AODV-SRA is compared by NS-2 simulation software under a variety of network conditions. It is also demonstrated how a small change to the AODV protocol can lead to significantly improved performance results.