Optimizing Neighbor Table Accuracy of Position-Based Routing Algorithms

In position-based routing protocols, each node periodically transmits a short hello message (called beacon) to announce its presence and position. Receiving nodes list all known neighbor nodes with their position in the neighbor table and remove entries after they have failed to receive a beacon for a certain time from the corresponding node. Especially in highly dynamic networks, the information stored in the neighbor table is often out-dated and does not reflect the actual topology of the network anymore such that retransmissions and rerouting are required which consume bandwidth and increase latency. Despite a considerable number of proposed position-based protocols, almost no analysis has been performed on the impact of beacons and the out-dated and inaccurate neighbor tables. We show by analytical and simulation results that performance suffers especially in highly mobile ad-hoc networks and propose several mechanisms to improve the accuracy of neighborhood information. Extensive simulations show the effectiveness of the proposed schemes to improve the network performance.