Unsaturated Performance of IEEE 802.11 Broadcast Service in Vehicle-to-Vehicle Networks

In this paper, we propose an analytic model for performance evaluation of IEEE 802.11 ad hoc broadcast networks without the assumption of saturation condition that is not true in safety related vehicle-to-vehicle (v2v) communication. We use a discrete time M/G/l queue to model occasional occurrences of safety related message in each vehicle. By means of probability generating function (PGF) and a recursive algorithm, we obtain solution to the analytic model. Based on the solution, we derive several important performance indices for IEEE 802.11 broadcast service, such as packet delay, throughput, packet delivery ratio, and service time distribution. The proposed analytic model is validated by extensive simulations. Numerical results also reveal characteristics of the broadcast service in a typical v2v wireless network.