An Adaptive Energy-Efficient and Low-Latency Mac Protocol for Wireless Sensor Networks

In this paper, an adaptive energy-efficient and low-latency MAC (L-MAC) protocol for wireless sensor networks is proposed. In this protocol, nodes have three modes-sleeping, receiving and sending. Each node goes to sleep periodically to save energy. L-MAC delays the receiving and sending period hop by hop, so that when one node is in sending mode, its lower-hop node is in receiving mode. After receiving a message from upper- hop node, each node can transmit it to lower-hop node in the sequent sending period. Therefore, the multi-hop end-to-end delay due to periodical sleeping is reduced greatly. Furthermore, an adaptive sleeping scheme which makes the nodes with lower traffic have longer time to sleep is adopted to save more energy. Simulation results show that L-MAC achieves lower energy consumption and latency than traditional contention-based protocols.