IRS and UAV-relay assisted public safety networks for video transmission: optimizing UAVs deployment and resource allocation

In disaster scenarios with cellular base station failures, the importance of wireless communication further rises, necessitating the deployment of Public Safety Communication (PSC) networks for critical missions. This manuscript delves into an innovative approach that harnesses the power of Unmanned Aerial Vehicles (UAVs) and Intelligent Reflecting Surfaces (IRS) to elevate the capabilities of a PSC network. Within this framework, an observation UAV (Ob-UAV) captures videos from ground users in affected areas (AGUs) and seamlessly relays them to nearby operational ground Base Stations (GBS) through a passive IRS-equipped UAV. The central objective is to maximize the average utility of video streams from AGUs at the GBS. The optimization involves positions of the observation UAV and IRS-UAV, IRS-UAV phase shift coefficients, and communication resource distribution. We formulate a mathematical solution addressing these optimizations with system-defined constraints. Due to the non-convex nature of the problem, finding a solution poses a significant challenge. To address this challenge, we suggest an efficient iterative algorithm that relies on block coordinate descent and successive convex approximation techniques. Thorough simulations confirm that our proposed optimization approach surpasses the outcomes of other compared schemes.