ReMAC: a novel hybrid and reservation-based MAC protocol for VANETs

The period in which a roadside unit (RSU) of a vehicle remains in the coverage area is too short in vehicular ad hoc networks (VANETs) in which the vehicles move at high speeds. In this short period, it is necessary for the vehicles to join the network and establish continuous communication with the RSU. To accomplish this, the RSU and vehicles need an efficient and robust media access control (MAC) protocol. In this study, a new reservation-based MAC (ReMAC) protocol in which multiple channels are used is suggested to ensure rapid connection to RSUs, smooth transition between RSUs, and efficient channel usage. The protocol uses the dedicated short-range communication (DSRC) standard’s data/control channels by dividing them into multiple subchannels to support efficient channel usage, rapid service provision, and high vehicle density scenarios. The simulation of the protocol was conducted with OPNET Modeler and the performance comparisons were carried out with the metrics such as channel access delay, channel collision rate, success rate, and throughput. These are the metrics that are used in VeMAC, CFR-MAC, TMMAC, and VATMAC protocols that exist in this area. All the simulation results show in all scenarios that ReMAC significantly surpassed the current protocols.