RAMC: A RSU-Assisted Multi-Channel Coordination MAC Protocol for VANET

This paper proposes a RSU assisted multi-channel coordination MAC (RAMC) protocol that fully utilizes all DSRC channels to provide simultaneous safety and non-safety communications. Within the radio range of a roadside unit (RSU), vehicles are free to tune to any service channels. The RSU monitors all the safety messages being transmitted in both the control and service channels. Periodically, the RSU broadcasts a consolidated traffic view report to all neighboring vehicles in all channels. Therefore, a vehicle can operate in a service channel as long as it needs to achieve high throughput for nonsafety applications, while maintaining adequate and timely safety awareness. Our simulation results show that the proposed RAMC protocol consistently provides high throughput for non-safety applications, while maintaining high safety message delivery ratios in various traffic density conditions.