Multi-Node Wireless Energy Charging in Sensor Networks

• Published in: IEEE/ACM transactions on networking Vol. 23; no. 2; pp. 437 - 450
• Main Authors: Liguang Xie, Yi Shi, Hou, Y. Thomas, Wenjing Lou, Sherali, Hanif D., Midkiff, Scott F.
• Format: Journal Article
• Language: English
• Published: IEEE 01.04.2015
• Subjects: Coils; Couplings; Energy consumption; Energy exchange; Magnetic resonance; Optimization; scalability; Wireless communication; wireless energy transfer; wireless sensor network; Wireless sensor networks
• ISSN: 1063-6692; 1558-2566
• DOI: 10.1109/TNET.2014.2303979

Wireless energy transfer based on magnetic resonant coupling is a promising technology to replenish energy to a wireless sensor network (WSN). However, charging sensor nodes one at a time poses a serious scalability problem. Recent advances in magnetic resonant coupling show that multiple nodes can be charged at the same time. In this paper, we exploit this multi-node wireless energy transfer technology and investigate whether it is a scalable technology to address energy issues in a WSN. We consider a wireless charging vehicle (WCV) periodically traveling inside a WSN and charging sensor nodes wirelessly. Based on charging range of the WCV, we propose a cellular structure that partitions the two-dimensional plane into adjacent hexagonal cells. We pursue a formal optimization framework by jointly optimizing traveling path, flow routing, and charging time. By employing discretization and a novel Reformulation-Linearization Technique (RLT), we develop a provably near-optimal solution for any desired level of accuracy. Through numerical results, we demonstrate that our solution can indeed address the charging scalability problem in a WSN.