RW-MAC: An asynchronous receiver-initiated ultra low power MAC protocol for Wireless Sensor Networks

In this paper, we present an asynchronous energy-efficient MAC protocol called RW-MAC for wireless sensor networks. RW-MAC is a receiver-initiated MAC which significantly reduces energy consumption by precisely predicting the re ceiver´s wakeup time while still achieves high concurrent performance. To minimize collision, we present an algorithm to stagger the wakeup time of each node in the same collision do main. RW-MAC also tries to optimize the send sequence to maximize the throughput. We have implemented RW-MAC on TinyOS and evaluated its performance on testbeds. The result shows RW-MAC achieves higher concurrent performance and lower energy consumption compared to RI-MAC and X-MAC.