On the Outage Probability of Interference-Limited Multi-Hop Linear Vehicular Ad-Hoc Network

The outage probability of an interference-limited linear vehicular ad hoc network (VANET) with random multiple access protocol is studied in this paper. All nodes in the VANET, including the intended transmitter-receiver pair and the interferers, are assumed to form a homogeneous Poisson point process. Communications between any two nodes in the network are carried out by using nodes between them as relays. For a given network section, more nodes between the source and the destination means more relays, thus a stronger signal component due to smaller pathloss between two neighboring nodes. Meanwhile, more nodes generate more mutual interference. A random multiple access protocol, where each node transmits with a certain probability, is adopted to reduce interference. To characterize the competing effects between pathloss and interference, we derive analytically the upper and lower bounds of the outage probability for a cluster of nodes over a fixed section of the network under the interference-limited environment. The outage probability bounds are derived as explicit functions of various system parameters, including the pathloss exponent, node mobility, transmission probability, and cluster size. Optimum designs are then performed to minimize the outage probability with respect to several system parameters, such as the node density, cluster size, and node mobilities.