Age-Optimal Data Gathering and Energy Recharging of UAV in Wireless Sensor Networks

Unmanned aerial vehicle (UAV) can act as an aerial data collector to efficiently gather fresh information in wireless sensor networks (WSNs). To support continuous data collection, the battery-powered UAV should be able to obtain energy supplements in time. In this paper, we propose a joint data gathering and energy recharging framework for age minimization in UAV-enabled WSNs. To discuss the impacts of the deployments of ground terminals and charging stations on the network age, we assume that the UAV’s action follows a stochastic policy. It flies from one terminal to another with some probability when its on-board energy is sufficient, otherwise flies to the nearest charging station to recharge its battery. The UAV-aided data collection problem with energy recharging is modeled as a non-linear optimization problem. With the aid of convex programming, a stochastic optimal policy is found to minimize the network peak age. Simulation results show that the network peak age performance is greatly affected by the intensities of the ground terminals and charging stations.