Highway propagation modeling in VANETS and its impact on performance evaluation

Available simulation studies on communication performance of Vehicular Ad-Hoc Networks (VANETs) in highway scenarios are based on different propagation models, often without empirical validation. In this paper, we present the results of a 5.9 GHz vehicle-to-vehicle (V2V) highway measurement campaign using commercial off-the-shelf hardware to gain insights into adequate path loss modeling. As most established models significantly deviate from the empirical results, we propose a propagation model for V2V communication on highways which reflects conditions found in reality sufficiently well to be applicable for VANET simulation studies. Due to the propagation model´s complex interdependencies with the CSMA-based medium access, interference and frame collisions in VANETs, we examine the impact of different propagation modeling approaches on the resulting communication performance for varying network loads based on a simulation study. The results reveal that both the applied path loss model and the severity of fading substantially influence the simulation results and hence should be modeled very carefully.