A range-based sleep scheduling algorithm for desired area coverage in solar-powered wireless sensor networks

Energy harvesting sensor networks sparked extensive research interest in recent years. However, little attention has been paid to sleep scheduling for area surveillance in rechargeable sensor networks. In this paper, we attempt to settle the problem of keeping rechargeable Wireless Sensor Networks operating for a long time while satisfying certain desired area coverage and energy consumption balance among sensor nodes. The energy harvested by a node is still limited and unstable. So we put forward a distributed heuristic range-based sleep scheduling algorithm which integrates the residual energy of nodes with the recharging frequency constraint. It aims to find out a small set of nodes running in the active mode whose energy evaluation functions are higher than their neighbors within the r_th-range. This algorithm is simple and does not need precise location information while guaranteeing area coverage. Simulation results show that the algorithm can prolong network lifetime compared to that of the network with nonrechargeable sensor nodes or with rechargeable nodes whereas lack of sleep scheduling corresponding to the uncertain energy supplements.