A Low-Latency MAC Protocol for Wireless Sensor Networks

In wireless sensor networks, Energy efficiency is the most important performance target to prolong the networks lifetime. As the idle listening of sensor nodes result in primary energy waste, many typical MAC protocols are designed to save power by placing the radio in the low-power sleep mode, however, such schemes can lead to sleep latency problems in multi-hop transmissions. This paper analyses the sleep latency, and proposes a low- latency MAC protocol (LLMAC), which uses asynchrony message package for frame schedule between neighbor nodes instead of SYNC package in S-MAC, and brings in the stagger active schedule mechanism to maintain the data forwarding transmission. Simulation results show much better performance of the latency control compared with the existing schemes.