OMA: A Multi-channel MAC Protocol with Opportunistic Media Access in Wireless Sensor Networks

To tackle control channel saturation problems, this paper proposes OMA, an asynchronous duty cycle based multi-channel MAC protocol with opportunistic media access for wireless sensor networks. By adopting opportunistic media access, OMA effectively alleviates, if not completely eliminates, control channel saturation problems. More importantly, OMA is fully distributed with no requirements of time synchronization or multi-radio. Therefore, OMA is very easy to be implemented in resource-constrained sensor nodes. Via the theoretical analysis, the opportunistic probability with which a node opportunistically access the control channel is obtained. To validate the effectiveness of opportunistic media access, extensive simulations and real test bed experiments were conducted. The simulation and experimental results show that when the number of channels is large or the network loads are heavy, OMA improves energy efficiency and throughput significantly compared with other works in the literature.