Abstract
Energy efficiency and coverage guarantee are two important issues in sensor networks. In wireless sensor networks, energy is a scarce resource. Any energy waste will directly affect the network lifetime. In a densely deployed sensor network, an event may trigger many nearby sensors that detect this event to transmit reports, thus causing a lot of redundant reports of the same event and wasting a lot of energy resource. In this paper, we propose a concept, called duty coverage (DC), such that a sensor only needs to report an event within its DC range. Whether an event is inside a DC range is done by determining the signal strength of the event. The coverage of the sensing field will not be reduced by doing so. We propose three distributed protocols for sensors to self-organize their duty coverage. We provide extensive simulation results to evaluate the performance of our protocols.