Novel methods for energy charging and data collection in wireless rechargeable sensor networks

In wireless rechargeable sensor networks, sensors are responsible for sensing environment and generating sensed data, and mobile devices are responsible for recharging sensors and/or collecting sensed data to the sink. Because of the rapid development of wireless charging technology, sensors can be recharged when they are within limited charging ranges of mobile devices. In addition, because sensors' electric capacity and memory storage are often limited, sensors must be recharged, and their generated data must be collected by mobile devices periodically, or the network cannot provide adequate quality of services. Therefore, the problem of scheduling minimum mobile devices to periodically recharge and collect data from sensors subject to the limited charging range, electric capacity, and memory storage, such that the network lifetime can be guaranteed to be prolonged without limits, termed the periodic energy replenishment and data collection problem, is studied in the paper. For the problem, the grid-based algorithm, the dominating-set-based algorithm, and the circle-intersection-based algorithm are proposed to find a set of anchor points. In addition, the mobile device scheduling algorithm is proposed to schedule minimum mobile devices to visit the generated anchor points. Simulation results show that our proposed methods provide good performance.