Abstract
In recent years, Vehicular Ad Hoc Networks (VANETs), which consists of On-Board Units (OBUs) and Road Side Units (RSUs), are becoming more and more popular. Due to the high expenditure on the deployment of RSUs, it is important to minimize the number of deployed RSUs while maintaining the same coverage. To this end, we propose a MAC protocol that can extend virtual transmission range at the same physical transmission range. The protocol enhances packet transmission across a long distance by utilizing opportunistic relaying and network coding. The use of opportunistic relaying improves the packet reception probability because relay nodes opportunistically forward packets when needed. The use of network coding decreases performance degradation caused by acknowledgement loss. As a result, our proposed protocol not only can be used to decrease the number of deployed RSUs but also helps to improve performance in terms of throughput and delay. Simulation results show that our proposed protocol outperforms several MAC protocols, including direct communication and deterministic relaying (both using IEEE 802.11). We also compare the simulation results with our analysis to ensure the correctness.