AoI━Energy Tradeoff Scheme for UAV-Assisted Wireless Sensor Network Data Collection

With advances in communication technology, the Internet of Things (IoT) has played an increasingly important role in real life, and the application of Unmanned Aerial Vehicle (UAV) communication in the IoT has been widely studied. UAVs are used as mobile data collectors to collect data from Sensor Nodes (SNs) in a WSN. The Age of Information (AoI) is introduced as an index for evaluating network performance. This paper proposes a data collection scheme based on UAV trajectory design and a scheduling strategy for SNs. Based on this scheme, a weighted minimization model is constructed to minimize the weighted sum of the Average AoI (AAoI) and energy consumption of the SNs by optimizing the trajectory of the UAV, the scheduling of the SNs, and the transmitting power. This mixed-integer nonlinear problem is usually difficult to solve directly. Therefore, the path discretization method is first used to discretize multiple continuous variables. Subsequently, a joint optimization algorithm based on Block Coordinate Descent (BCD) and Successive Convex Approximation (SCA) is proposed to obtain a local optimal solution that satisfies the KKT condition. The simulation results show an effective balance between the AoI and the energy consumption of the SNs, demonstrating the feasibility of the proposed scheme.