Position-aided on demand routing protocol for wireless ad hoc networks

This paper presents the design of a position-aided on demand routing (PAR) protocol. The objective is to effectively reduce the communication overhead associated with path discovery and maintenance with the assistance of position information. For this purpose, PAR employs a novel restricted directional flooding mechanism. This mechanism creates an ellipse-forwarding zone, across which control messages are propagated for route discovery. Moreover, PAR uses location-guided expanding ring search, which works by searching successively larger areas for paths. This searching strategy can effectively prevent unnecessary network-wide flooding. In terms of location tracking, we design a method of recursive passive listening at intermediate nodes for end-to-end location tracking. This method enables the source to effectively keep track of the up-to-date location of its communication partner at little control overhead. Simulation results demonstrate that the PAR protocol can significantly reduce the communication overhead associated with path discovery, compared with related work.