Enhanced epsilon-Self-Sorting Based MAC Protocol for Multi-Density Vehicular Ad Hoc Networks

Vehicular ad hoc networks (VANETs) have great potential in improving the transportation safety and efficiency. We have recently proposed a self-sorting based medium access control protocol [1] for high-density scenarios. It allows vehicles to establish a logic queue by a self-sorting process before data transmission. An enhanced ϵ-self-sorting based algorithm is proposed in this paper to overcome the shortage of the original algorithm in sparse scenarios. In the enhanced algorithm, vehicles can terminate the self-sorting process before the length of the logic queue reaches the set threshold. It is determined by a transmission opportunity function defined in this paper which makes the algorithm more flexible. The analysis and simulation results reveal that the enhanced ϵ-self-sorting algorithm can significantly improve the performance in sparse scenarios. The flexible design of the queue forming makes the enhanced ϵ-self-sorting algorithm applicable to multi-density scenarios.