GRTR: A Geocasting Routing Based Target Region for VANET

Vehicular ad hoc networks (VANET) are characterized by the frequent changes and constrained by pre-existing roads in network topology compared with mobile ad hoc network (MANET). Therefore, the method of geocasting routing can not be widely applied to VANET. This paper proposes a geocasting routing based target region for VANET (GRTR) to make match road topology in VANET. That is setting a target region in the intersections from source node to destination region and using the method of VD-GREEDY (Voronoi diagram-greedy) builds forward zones to transmit information between the target regions. The method of VD-GREEDY expands forward zone to ensure the existence of next-hop nodes and limits the numbers of next Chop nodes to lower overhead. At the same time, to lower overload, we use the way of opportunistic routing in the target region where we choose the best node to go on transmitting for next target region. The proposed method matches the road conditions and lowers the overload in VANET.