Minimizing Age of Synchronization Through Aerial Intelligent Reflecting Surfaces

Aerial intelligent reflection surface offers opportunities to increase the data freshness in challenging environments. In this paper, we investigate the integration of unmanned aerial vehicles (UAVs) and intelligent reflection surface (IRS) to assist the transmission from sensor nodes (SNs) to a base station (BS). Our goal is to minimize the Age of Synchronization (AoS) by optimizing the UAV trajectory, SNs schedule, and IRS phase-shift. An actor-critic optimization algorithm is developed to solve the mixed- integer non-convex optimization problem. Numerical results demonstrate the algorithm's superior performance in reducing the AoS compared to existing methods.