A Low Latency and Energy Efficient MAC Protocol Based on Packet Reordering for Wireless Sensor Networks

Energy efficiency is one of the most concerned issues in wireless sensor networks,and periodic listen/ sleep mechanism is widely used to reduce energy consumption. However,the efficiency in energy consumption of those protocols with periodic listen/sleep mechanism is achieved at the expense of compromise in the latency,and the end to end delay is in direct proportion to the duration of the cycle. In this paper,we propose a low latency and energy efficient MAC protocol named RLL-MAC based on the famous S-MAC/AL ( S-MAC with Adaptive Listening) . RLL-MAC can dynamically adjust the packet transmission order according to the timing relationship of listen period between the source and the destinations,with which,RLL-MAC can cut down the packet end to end delay greatly. Simulations have been done to evaluate the performance of the proposed new protocol,by which we can find out that,besides keeping the energy efficiency,RLL-MAC can really reduce packet end-to-end delay compared with S-MAC/AL.