A dynamic sleep MAC protocol for wireless sensor networks

It has been proved radio sleep can significantly prolong the lifetime of wireless sensor networks; however, sleep causes more multi-hop latency and fewer throughputs under heavy load. This paper proposes a dynamic sleep MAC protocol LD3-MAC for wireless sensor networks, which uses global schedule, stagger sleep and periodic synchronization to achieve sleep coordination. The dynamic listening scheme that employs limited contention and extended listening is proposed to reduce forward delay and collision. In addition, the dynamic duty cycle scheme is used to adjust the regular listening period according to the traffic load, which further improves the space efficiency of channel. LD3-MAC was evaluated through NS-2 simulation; the results show that the scheme reduces energy consumption and latency, and improves deliver ratio under heavy traffic load.