Priority-Based MAC Protocol For Vehicle Collision-Avoidance System Via Inter-Vehicle Communication Networks

In this paper, we propose an approach to vehicle collision-avoidance system by broadcasting vehicles’ driving conditions via Inter-Vehicle Communication (IVC) networks. We study the use of Elimination Yield Nonpreemptive Priority Multiple Access (EY-NPMA) Medium Access Control (MAC) protocol. This protocol is used in the High Performance Radio LAN (HIPERLAN) system being developed in Europe. In contrast to the IEEE 802.11 CSMA MAC protocol, EY-NPMA uses priority levels to access the medium. In our approach, a vehicle gains access to the medium among other contending vehicles based on its speed. Since low-speed vehicles pose a hazardous situation in a highway traffic, a lowspeed vehicle has a higher priority than a high-speed vehicle. Thus, a low-speed vehicle gains access to the medium and starts transmitting its driving conditions to other vehicles. This paper presents a detailed description of this protocol and shows the feasibility study results of the use of this protocol in IVC networks.