CMAC - A Multi-Channel Energy Efficient MAC for Wireless Sensor Networks

This paper presents CMAC, a fully desynchronized MAC protocol that is designed to exploit the existing multi-channel support in sensor nodes. The hardware requirements of our protocol are minimal, requiring a single half-duplex transceiver and a low-power wake-up radio. CMAC takes into account the fundamental energy constraint in sensor nodes by placing them in a default sleep mode and waking them up only when necessary. As a contrast to other dual radio wake-up schemes, our protocol focuses on how communication and its preceding control message exchange mechanism can be undertaken in a multi-channel scenario without assuming a separate control channel. CMAC enables spatial channel re-use, nearly collision free communication, and addresses the deafness problem without incurring a tradeoff in fairness or latency. When compared with a recent MAC protocol SMAC, results show that CMAC obtains nearly 200% reduction in energy consumption, significantly improved throughput, and end-to-end delay values that are 50-150% better than SMAC for our simulated topologies.