A Beacon-Less Geographic Multipath Routing Protocol for Ad Hoc Networks

Multipath routing has been considered as one of the most efficient and reliable routing solutions for ad hoc networks. Compared with the link-disjoint paths, the node-disjoint paths are less likely to fail and provide better performance for load balancing. In this paper, a novel multipath routing protocol called BGM (Beacon-less Geographic Multipath routing protocol) is proposed to construct maximally node-disjoint multiple paths. Unlike most existing multipath routing protocols based on AODV or DSR, the proposed geographic routing algorithm utilizes location information to discover multiple paths. Therefore it avoids lots of control messages caused by route discovery and maintenance in the topology-based protocols. In the proposed scheme, each node discovers multiple paths and forwards data packets within a disjoint sub-zone divided by a division algorithm. Moreover, in order to reduce the control overhead, a distributed forwarding strategy is presented by applying the beacon-less mechanism. The beacon-less mechanism does not require nodes to periodically broadcast the Hello messages. Instead, the neighbors of a forwarding node contend to deliver data packets. Simulation results show that BGM not only improves the efficiency of the path discovery, but also reduces the control overhead. Also, BGM provides relatively short end-to-end delay while keeping the packet delivery ratio above 95 %.