Peak Age of Information Minimization for UAV-Aided Wireless Sensing and Communications

The freshness of information characterized by the age-of-information (AoI) is a key performance indicator (KPI) in Internet of Things (IoT) networks. In this paper, we consider a wireless sensor network (WSN) with an unmanned aerial vehicle (UAV) as a relay. A sensing-then-forwarding scheme is proposed, where the UAV first collects data packets from all sensor nodes and then forwards to a destination node. The average peak AoI is minimized by jointly optimizing the UAV trajectory, communication power, and service time. The feasibility of the formulated problem can be checked by solving a second order cone programming (SOCP), and a successive convex approximation (SCA) based algorithm with provable convergence is developed to obtain an at least suboptimal solution. Through extensive simulations, the proposed algorithm is shown to provide better convergence and much smaller peak AoI than the alternating optimization (AO) based algorithm.