An Energy-Efficient Asynchronous MAC for Bulk-Data Collection in Wireless Sensor Networks

In this paper, we propose a new asynchronous MAC protocol, the AW-MAC, for bulk-data collection in wireless sensor networks. We develop a routing-enhanced adaptive wakeup mechanism and an on-demand channel assignment scheme that allow the protocol to transform from single channel asynchronous schedule to multi-channel TDMA schedule in an on-demand fashion. These schemes overcome the sleep latency problem of duty-cycling and avoid the inefficiency of unscheduled asynchronous channel access. The simulation results show that our protocol largely reduces the latency on collecting bulk data then the state-of-the-art asynchronous duty-cycle MAC protocol while consuming similar energy.