An energy saving medium access control protocol for wireless sensor networks

Medium access control (MAC) protocols for wireless sensor networks (WSNs), consider the utilization of batteries of individual sensor nodes to extend the overall network lifetime. In this paper, an energy saving medium access control (ES-MAC) protocol is proposed. ES-MAC allows a cluster head to wake for a short duration at the beginning of each slot in a session/frame. If the cluster head doesn't hear anything from the node assigned for the slot, then it goes into sleep state (radio is turned OFF) till the beginning of the next slot. But if the cluster head receives any data from the corresponding node, it continues to listen till the end of that slot. Unlike some existing event-driven MAC protocols namely BMA-MAC, BEE-MAC, and LDC-MAC, the proposed protocol does not include any contention period/control period within a frame. This saves the energy which would be consumed otherwise, in sending and receiving control packets during this period. The simulation results show that ES-MAC reduces the energy consumption compared to BMA-MAC, BEE-MAC, and LDC-MAC.