Extending Network Lifetime for Wireless Rechargeable Sensor Network Systems through Partial Charge

Recent breakthrough in wireless power transfer technology provides a promising way for empowering sensors wirelessly, enabling them to work perpetually. Traditional research paid close attention to enhancing the system performance, but overlooks the impact of charging behavior. To address this issue, in this article, we propose a charging scheduling scheme, termed Partial Charge, which can partially charge a sensor node to minimize the overall node dead time so as to prolong the network lifetime. At first, we determine the appropriate ratio for nodes, which needs to be charged partially. Then we prioritize sensors based on their contributions to the charging tasks and always select core nodes to serve. Afterwards, a node delete scheme is proposed to exclude nodes that cannot be saved or degrade the charging performance. Finally, simulation experiments are conducted to show the merits of the proposed scheme, revealing that our scheme outperforms other competing schemes in terms of shorter service time, bigger survival rate, and smaller waiting queue.