Performance Analysis of ITS V2V Broadcast Communication Using CSMA/CA and a Roadside Relay Station at Intersections

Abstract

The reliability of Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) vehicle-to-vehicle (V2V) communication in real road environments suffers from fading, shadowing and the hidden terminal problem, especially for non-line-of sight (NLOS) areas such as intersections. In order to improve the communication reliability, a CSMA/CA based vehicle-roadside-vehicle broadcast relay network was proposed and its effectiveness has been shown through simulations. However, the potential of such a network has not been well analyzed and optimized. In this paper, a theoretical model is proposed to analyze the performance of the broadcast relay network in detail. In order to fit real vehicular environments, the model assumes a typical crossroad and takes into account fading, shadowing, the hidden terminal problem and the capture effect. The influence of system parameters including position of nodes, carrier sense threshold and RF frequency band on the reliability of the network is studied based on the model. The accuracy of the proposed analytical model is confirmed by simulations. The analytical model and the obtained results are useful for the design of vehicular broadcast networks to select appropriate system parameters.