We propose  B-MAC , a carrier sense media access protocol for wireless sensor networks that provides a flexible interface to obtain ultra low power operation, effective collision avoidance, and high channel utilization. To achieve low power operation,  B-MAC  employs an adaptive preamble sampling scheme to reduce duty cycle and minimize idle listening.  B-MAC  supports on-the-fly reconfiguration and provides bidirectional interfaces for system services to optimize performance, whether it be for throughput, latency, or power conservation. We build an analytical model of a class of sensor network applications. We use the model to show the effect of changing  B-MAC 's parameters and predict the behavior of sensor network applications. By comparing  B-MAC  to conventional 802.11-inspired protocols, specifically SMAC, we develop an experimental characterization of  B-MAC  over a wide range of network conditions. We show that  B-MAC 's flexibility results in better packet delivery rates, throughput, latency, and energy consumption than S-MAC. By deploying a real world monitoring application with multihop networking, we validate our protocol design and model. Our results illustrate the need for flexible protocols to effectively realize energy efficient sensor network applications.
['Joseph Polastre', 'Jason L. Hill', 'David E. Culler']
Versatile low power media access for wireless sensor networks