Medium Reservation Based MAC for Delay-Sensitive Wireless Sensor Network

In this paper, we present a new MAC protocol satisfying with both high energy efficiency and low transmission latency at the same time over wireless sensor network, named as medium reservation preamble based MAC (MRPM). The proposed MRPM is a synchronized duty cycle MAC protocol. MRPM has three main features. The first feature is that MRPM does not have separate time frames for Sync and data traffics. Both traffics are integrated in a short listen period. The second feature is the novel approach of medium reservation done by a transmitter. That is, the contention period precedes the listen period, and only transmitters wake up in this contention period and contend for medium reservation, avoiding the non-transmitters from idle listening. The above-mentioned two features have made MRPM to achieve listen period of very short length, which make our protocol energy efficient. As the final feature, MRPM uses carrier sensing information for advanced adaptive listening which makes packets travel multiple hops away in a single sleep/listen cycle. We compared MRPM with S-MAC and TEEM protocols through ns-2 simulation. The simulation results show that MRPM outperforms S-MAC and TEEM at both metrics of energy efficiency and latency.