Efficient Geographic Routing for Ad Hoc Vehicle Networks

Abstract

As a specific instance of mobile ad hoc networks (MANET), VANET has become increasingly an attractive technology in terms of security and comfort provided to vehicle users. During inter-vehicular communication (V2V) we are confronted with various problems related to packet routing. However, VANET is characterized not only by high mobility, hence the rapid change of topology, but also by considerable congestion and a prohibitive presence of interference. Indeed, overload failures and link breaks can occur resulting in considerable packet loss, increased transmission delays (latency), jitter variation or even worse, frequent network disconnection. This situation degrades the performance of all types of routing, including geographic routing. To remedy this situation, fault tolerance mechanisms are used to make the VANET vehicular communication system capable of remaining operational in spite of failures that occur with high throughput and low response time. In this paper we present an improved version of GPSR, named OP-GPSR, which is based on a multi-criteria analytical model for geographic routing that is tolerant of link failures, link and node overload, and abrupt network disconnection. This solution is based on a multi-criteria cost function that optimizes the selection of the stable, reliable and uncongested nearest neighbour expressed in terms of predictive distance, degree of mobility, node load and link quality. Simulation results show that the proposed approach (OP-GPSR) provides better performance in terms of packet delivery rate, packet loss rate, end-to-end delay, overhead rate and interference and best predicts link failures ( breakage, overload and congestion).