MSR: Minimum-Stop Recharging Scheme for Wireless Rechargeable Sensor Networks

This paper deals with simultaneous energy transfer to multiple nodes for scalable wireless recharging in wireless sensor networks. All existing recharging schemes rely on the use of a mobile charger that roves the network and drops by some locations for nodes recharging. However, they focus on the efficiency of energy transfer and neglect the energy engendered by the charger movement. This is tackled in this paper, where the wireless charging is modeled as a path optimization problem for the mobile charger, with objective function to minimizing the number of stop locations in the path. Due to the NP-harness of the problem, we propose a simple but efficient heuristic. It is based on clique partitioning to find the minimum number of locations allowing the mobile charger to replenish all the node´s batteries in the network. Evaluation results demonstrate that the proposed approach significantly reduces the total energy consumption of the mobile charger, while using a low-complexity techniques that permit scalability to a higher number of nodes.