VANET communication: A traffic flow approach

Macroscopic fluid traffic flow models are used in this paper to predict connectivity behavior within vehicular to vehicular (V2V) networks. The vehicular density determines the radio connectivity in sparse traffic, and may even contribute to radio interference in dense traffic situations. We propose modeling the vehicular density using an approach from physics and engineering known as traffic flow theory. It builds models of the interactions between vehicles and road infrastructure similar to fluid or gas flows in pipelines. We have developed analytic solutions for estimating vehicular densities based on a method for solving the traffic flow equations. With very general infrastructure conditions we can find the density evolution at any location and time for any (given) initial conditions. Using such an approach we show how the connectivity, reachability and broadcast capacities of V2V networks can be calculated as applications of this approach. Furthermore we can include the path loss between vehicles and include interference from dense traffic situations in line and non-line of sight situations. We parameterize the method using Bluetooth and IEEE 802.11a radio technologies to show the applicability of such an approach.