Low-latency mobile data collection for Wireless Rechargeable Sensor Networks

Wireless charging is a game-changing technology to provide reliable energy source for wireless sensor networks. Combining wireless charging with mobile data collection on a single mobile vehicle can mitigate the nonuniform energy distribution problem. However, data latency may be too long for some applications because vehicles have to spend significant time in charging before uploading data to the base station. In this paper, we propose a new framework that employs a dedicated vehicle for data collection and theoretically study the trade-offs between data latency and the number of recharging vehicles needed. We first study how to minimize data latency while ensuring all sensory data are collected and derive a latency bound. Then we establish a mathematical model to calculate the minimum number of recharging vehicles needed. Finally, we conduct simulations to validate the theoretical results and evaluate the efficiency of the framework. The results show that our scheme can reduce the number of nonfunctional nodes by 30-60%, and cut down data collection latency more than an order of magnitude compared to the previous work.