J-RCA: A Joint Routing and Charging Algorithm with WCE Assisted Data Gathering in Wireless Rechargeable Sensor Networks

With the development of wireless charging technology, the wireless energy replenishment using mobile wireless charging equipment (WCE) has been a promising way to prolong the lifetime of wireless rechargeable sensor networks (WRSNs). However, many existing researches have neglected some dynamic factors (e.g. topology changes in routing selection) which lead to low energy efficiency of charging tour. In this paper, a joint routing and charging algorithm (J-RCA) with WCE assisted data gathering is proposed to increase the network lifetime (NL). For routing, an improved Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method is presented to balance energy consumption of nodes, which can fully consider the difference between indexes to select the optimal next hop. In terms of charging, we present a two-step charging scheme that includes calculating the shortest Hamilton cycle of original charging nodes and selecting the other nodes called passer-by nodes. That is, when WCE moves along the shortest Hamilton cycle, it considers both routing requirements and spatial location to pick up some passer-by nodes for energy replenishment with the extra energy. In this way, the energy carried by WCE can be fully utilized and NL can be effectively extended. The simulation results demonstrate that the proposed algorithm has certain advantages in prolonging NL and improving transmission reliability.