A Proposal of Link Metric for Next-Hop Forwarding Methods in Vehicular Ad Hoc Networks

An inter-vehicle communication system, called vehicular ad hoc network (VANET), is one of the most promising applications of a mobile ad hoc network (MANET). One of the important issues in VANET is scalability. Compared with topology-based routing protocols, a routing protocol using position information may alleviate the issues of scalability or control overhead. Car navigation systems using a global positioning system (GPS) are widespread, and position-based routing is a useful approach in VANETs. A next-hop forwarding method is a type of position-based routing protocol, wherein a selection scheme for the next-hop node is very important. In this paper, we propose a novel selection scheme for the next-hop node in the next-hop forwarding method in VANET. In the proposed scheme, a new link metric, expected progress distance, is introduced in order to consider both forwarding distance and transmission quality of the wireless link. We evaluate the performance of our proposed scheme, and show that it can achieve much higher throughput and a better packet delivery ratio than existing conventional schemes.