Dynamic Channel Assignment MAC Protocol for Cognitive Radio Ad Hoc Networks (CRAHNs)

In Cognitive Radio Ad Hoc Networks (CRAHNs), the Medium Access Control (MAC) protocol should handle the diverse Quality of Service (QoS) requirements of data packets of various classes generated by the nodes. The delay and reliability requirements of various applications should be considered while assigning the channels to the nodes. Hence in this paper, we propose to design a channel quality based MAC protocol for CRAHNs. In this technique, a channel with best Channel Quality Indicator (CQI) is chosen as the Common Control Channel (CCC). The CCC is assigned dynamically in each round. The channels with higher weights are assigned to higher priority traffic classes. Initially backup channels are assigned only to the nodes with higher priority real-time traffic. If a data channel is not available for any lower priority traffic, then the backup channels of higher priority traffic can be temporarily assigned to the lower priority traffic nodes. By simulation results, we show that the proposed technique reduces packet drop rate, error rate and increases packet delivery ratio and throughput.