Reliable and Energy-Efficient UAV Communications: A Cost-Aware Perspective

Unmanned aerial vehicles (UAVs) are expected to play an important role in future wireless networks, serving as communication relays, computing servers, and flying infrastructure for ground users when ground-based infrastructure is congested or inaccessible. However, typical UAVs are powered by on-board batteries, which results in limited battery lifetime and poses a major restriction for UAV applications in communications. To overcome this, we propose a consistent and cost-aware energy procurement framework for a UAV powered concurrently by laser beams, emitted from locally deployed laser beam directors, and local renewable energy (RE) sources. The UAV intends to lower its overall energy cost for a certain operation cycle by optimizing the quantities of energy obtained from its battery as well as laser beams at each time period. Given the optimization results, we also propose a cost-aware UAV placement strategy with the ultimate goal of ensuring quality communication-energy links for the UAV, ground devices (GDs) and users. In addition, we assess the amount of additional procured RE that can be transferred via wireless power transfer to charge a set of distributed GDs. The simulations provide interesting insights into the efficiency of the proposed framework.