Selective Route-Request Scheme for On-demand Routing Protocols in Ad Hoc Networks

摘要

The on-demand routing protocols are appealing because of their lower routing overhead in bandwidth restricted mobile ad hoc networks, compared with Table-driven routing protocol. They introduce routing overhead only in the presence of data packets that need routes. However, the control overhead of on-demand routing protocols is increased by node mobility, node geographic density and traffic pattern density. In fact, this is undesirable feature for the scalable routing protocols whose control overhead should be under control to keep up with increasing offered load. The fundamental cause of these drawbacks is produced by flooding RouteRequest (RREQ) packet. As a solution for such a drawback of current on-demand routing schemes, we propose Selective Request Scheme (SR scheme). In this protocol, the stability of local network can be improved by re-floods or discards RREQ. Therefore in dynamic environment and limited bandwidth, SR Scheme assists in discovery the robust route and reduces the number of flooded RREQ packet. We demonstrate the effectiveness of our enhancement by applying it to Ad hoc On-demand Distance Vector Routing (AODV). Simulation results show that proposed idea significantly reduces the control overhead and improves the performance and scalability of the routing protocols.