Multi-radio medium access control protocol for wireless sensor networks

This paper describes a dual-radio based medium access control protocol for wireless sensor networks. Our protocol combines the advantages of the two radios operating in different frequency bands to result in highly energy-efficient operation. The design effectively addresses the two dominant sources of energy consumption in sensor network communication, namely the idle listening and the ephemeral burst data traffic. This paper presents the design rationale and extensive empirical performance evaluation of the protocol in terms of power consumption and latency under various traffic loads and duty cycles. Experimental performance comparison with B-MAC show high gains of our approach. We derive analytical expression for the optimum transmit power level ratio of the two radios giving minimum energy consumption. We also model the mathematical relationship for the optimal duty cycle of the nodes to a given network traffic load and validate it through the prototype implementation on commercially available sensor nodes.