An Improved Coordinated Multichannel MAC Scheme by Efficient Use of Idle Service Channels for VANETs

In this paper, an improved coordinated multichannel media access control (IC-MAC) scheme by efficient use of idle service channels is proposed for vehicular ad-hoc networks (VANETs). Different from the existing coordinated multichannel MAC (C-MAC) scheme based on IEEE 802.11p and 1609.4, an improved mechanism for service channel reservation and service message transmission is introduced in the proposed IC-MAC schemes. With the proposed mechanism, the idle service channel of the reservation time can be used to transmit service messages when the quality-of-service (QoS) of safety messages is guaranteed. To evaluate the performance of the IC-MAC scheme, the throughput and delay of service messages are derived. Simulation results demonstrate that the throughput and delay performance can be improved by using the proposed IC-MAC scheme.