Review of Multi-channel MAC Protocols for Vehicular Ad Hoc Networks

Vehicular ad hoc networks (VANETs) need to support the timely end-to-end transmissions of safety and non-safety messages. Medium access control (MAC) protocols can ensure fair and efficient sharing of channel resources among multiple vehicles for VANETs, which can provide timely packet transmissions and significantly improve road safety. According to the physical division of spectrum resources, the MAC protocols are divided into single-channel MAC protocols and multi-channel MAC protocols. In this paper, we briefly introduce some multi-channel MAC protocols for VANETs, and then summarize and qualitatively compare them. Finally, we discuss the open issues to improve the MAC performance and future work on MAC design for VANETs.