PMAC: Energy efficient medium access control protocol for wireless sensor networks

PMAC is a medium access protocol designed for wireless sensor networks. The protocol is based on exploiting the periodicity inherent in carrier sensing schemes like CSMA/CA combined with a relaxed time-access arbitration regime among the competing nodes. Transmission and reception of data frames are made to be strictly receiver-triggered events which makes it possible to bring down idle-listening drastically. The protocol also provides a way to make the channel access collision-free among the two-degree neighbors. PMAC requires no additional control signaling and no network-wide synchronization. The protocol design is not based on making any tradeoffs for the gains in energy efficiency with latency or throughput. It presents high-energy efficiency and throughput improvement in low as well as high-traffic scenarios. The performance of PMAC protocol is demonstrated using simulations and compared with SMAC protocol. In the results presented, PMAC provides an energy-efficiency by a factor of 3-8 when compared with SMAC. Also, latency improvement goes up by a factor of 5 and throughput increases by a factor of 3 on average.