Hybrid Multi-Channel MAC Protocol for Wireless Sensor Networks: Interference Rate Evaluation

This paper evaluates a channel allocation algorithm of a Hybrid Multi-Channel MAC protocol, HMC-MAC, that tries to improve communication performance in Wireless Sensor Networks (WSNs). We also analyze different techniques that are used in multi-channel MAC protocols proposed for WSNs. These protocols often use either a schedule-based or a contention based MAC protocol to communicate with each others. HMC-MAC takes advantage of the synchronous activity of TDMA to achieve collision free communications, of the flexibility offered by CSMA/CA to offer a scalable network, and of the parallel transmissions over different channels provided by FDMA to enhance the overall throughput. HMC-MAC assumes that sensor nodes are equipped with one half-duplex radio interface. We define a new method for channel allocation that enables nodes to choose the most convenient channel in its three-hop neighborhood in order to minimize interference as much possible. Simulation results demonstrate that HMC-MAC provides smaller interference rate and outperforms other mechanisms.