Preventive Time Slot Allocation MAC Protocol for Vehicular Networks

Dense and mobile wireless networks pose a significant challenge for Medium Access Control (MAC) protocols due to communication collision. These collisions cause network disruption, high latency, packet loss, and energy waste. To tackle this problem, researchers have used Road Side Units (RSUs) in vehicular networks to coordinate between vehicles in order to detect, avoid, and resolve collisions. However, the majority of the proposed solutions are based on vehicle localization information via a Global Positioning System (GPS) and random time-slot assignment. These solutions consume a lot of energy, produce high overhead, and are inefficient. In this paper, we propose an efficient MAC protocol called Preventive Time Slot Allocation "PTA" for vehicular networks. Our protocol minimizes future communication collisions, message propagation delay, and energy consumption by having RSUs assign time slots to incoming vehicles based on their predicted sojourn-time. Simulation results show that our protocol is capable of reducing collisions by at least 50% and communication delay by at least 40% when compared to a major state-of-the-art MAC protocol for vehicles moving in a straight line without junctions.