An optimal multi-channel coordination scheme for IEEE 802.11p based Vehicular Adhoc Networks (VANETs)

The Wireless Access in Vehicular Environment (WAVE) architecture enables V2X communication through an IEEE 802.11p and 1609.1-4 standards for improving safety and comfort of users. The 1609.4 standard supports multi-channel operations with a Control Channel (CCH) and six Service Channels (SCH). Transmission of critical safety messages and improving network throughput are challenging tasks with the fixed channel interval. Moreover, the highly dynamic wireless vehicular network and non-predictable traffic load demands the dynamic adjustments in the channel interval. To cope this, an optimal Dynamic Channel Interval MAC (DCI-MAC) protocol is proposed which regulates the duration of SCH interval and CCH interval based on number of vehicles, message priority, and packets in Access Category (AC) queues. DCI-MAC determines the optimal CCH interval which is proportional to the time needed to transmit the safety messages waiting in the AC queues. The remaining channel interval is utilized for the transmission of non-safety messages on SCH. To validate the proposed DCI-MAC protocol, the simulations are carried out in NS3 along with SUMO tool for real-time mobility in urban/highway scenarios. The simulated results reveal that the proposed DCI-MAC protocol outperforms the fixed and other variable channel interval schemes.