Cost-efficient UAV Deployment for Content Fetching in Cellular D2D Systems

Content caching at base stations (BSs), unmanned aerial vehicles (UAVs) and specific user devices is expected to enhance the performance of content fetching significantly. In this paper, we study the UAV deployment problem in UAV-enabled cellular device-to-device (D2D) systems. Stressing the importance of content fetching delay and energy consumption, as well as the cost for deploying UAVs, we define a cost function and formulate the joint UAV deployment and user association problem as a cost function minimization problem. We then propose a heuristic algorithm to solve the optimization problem and determine the joint strategy. Numerical results verify the effectiveness of the proposed algorithm.