Performance modeling of IEEE 802.11 DCF based fair channel access for vehicular-to-roadside communication in a non-saturated state

This paper considers the fair access problem in vehicular ad hoc networks (VANETs) and develops an analytical model for analyzing the performance of an IEEE 802.11 DCF based fair channel access protocol in a non-saturated state. We derive the relationship between the transmission probability and the minimum contention window size of a vehicle, and the relationship between the velocity and the minimum contention window size of a vehicle in a non-saturated state. Based on the analytical model the minimum contention window size of a vehicle for a given velocity can be determined in order to achieve fair access among different vehicles. The effectiveness of the analytical model is justified through simulation results.