Abstract
For lifetime extension, energy-efficient medium-access control (MAC) protocols designed for battery-powered wireless sensor networks (WSNs) usually enable nodes to operate in low duty cycle. However, without offline change in system parameters, existing protocols either save energy at a cost of long latency or work well only for a narrow range of traffic load. To remedy these problems, this paper presents CBA-EVT, an energy-efficient MAC protocol that is self-organizing in the presence of different operating regimes. To be self-organizing, CBA-EVT leverages two techniques - cost benefit analysis and extreme-value theory. CBA-EVT uses the cost benefit analysis that considers both delay and energy consumption to determine the sleep schedule from a macroscopic view; while it exploits extreme value theory to adjust duty cycle at a microscopic aspect. Through simulation, we confirm that compared with existing energy-efficient MAC protocols designed for WSNs given a delay bound, CBA-EVT with a single set of system parameters achieves significant energy savings at a wide range of traffic load. © 2014 IEEE.