An Efficient Multi-channel MAC Protocol for Vehicular Ad Hoc Networks

The multi-channel MAC protocols provide not only reliable transmission of safety application but also the maximal throughput for non-safety application in Vehicle Ad Hoc Networks (VANETs). One such scheme is to employ both TDMA and CSMA schemes in the Control CHannel (CCH). A vehicle will send safety message without collision on the TDMA-based period during its reserved time slot and utilize the SCH resources on the CSMA-based period for the non-safety message. In this paper, we propose a modification of a dedicated multi-channel MAC protocol(DMMAC) protocol (called EMMAC protocol). The EMMAC protocol can reduce the transmission overhead when node density is high and outperform the DMMAC protocol in terms of packet delivery ratio.