Maximizing charging throughput in rechargeable sensor networks

Energy is one of the most critical optimization objectives in wireless sensor networks. Compared with renewable energy harvesting technology, wireless energy transfer based on magnetic resonant coupling is able to provide more reliable energy supplies for sensors in wireless rechargeable sensor networks. The adoption of wireless mobile chargers (mobile vehicles) to replenish sensors' energy has attracted much attention recently by the research community. Most existing studies assume that the energy consumption rates of sensors in the entire network lifetime are fixed or given in advance, and no constraint is imposed on the mobile charger (e.g., its travel distance per tour). In this paper, we consider the dynamic sensing and transmission behaviors of sensors, by providing a novel charging paradigm and proposing efficient sensor charging algorithms. Specifically, we first formulate a charging throughput maximization problem. Since the problem is NP-hard, we then devise an offline approximation algorithm and online heuristics for it. We finally conduct extensive experimental simulations to evaluate the performance of the proposed algorithms. Experimental results demonstrate that the proposed algorithms are efficient.