Quantifying Performance Requirements of Vehicle-to-Vehicle Communication Protocols for Rear-End Collision Avoidance

We derive analytical bounds for the maximum acceptable message delivery latency and the minimum required retransmission frequency of 802.11-based vehicle-to-vehicle (V2V) communication protocols for rear-end collision avoidance applications. Using a microscopic car-following model of highway traffic combined with a probabilistic two-ray ground propagation model of the V2V wireless channel, we numerically investigate variations in these bounds with mean vehicular velocity, road grip coefficient, V2V packet loss rate and wireless channel fluctuation. Our analysis provides new quantitative guidelines and analytical inputs for the design of adaptive V2V protocols, which are capable of maintaining high reliability and efficiency in the face of large variations in vehicular traffic and V2V network conditions.