This chapter delves into theproblem of wireless-aware path planning for UAVs with a focus on cellular-connected UAV user equipment (UAV UE) that can communicate with ground cellular networks. To this end, we present a very focused study on interference-aware path planning for cellular-connected UAV UEs, in which each UAV aims at achieving a tradeoff between various quality-of-service and mission goals, such as minimizingwireless latency and interference caused on the ground network. To this end, we first motivate the need for wireless-aware path planning for UAV UE and, then, we introduce a rigorous system model for a wireless network with UAV UEs. We then formally pose the wireless-aware path planning problem for UAV UEs using the framework of game theory. We subsequently provide a reinforcement learning solution that can be used to design autonomous, self-organizing wireless-aware path planning mechanisms for UAV UEs while balancing the various wireless and mission objectives of the drones. We also show how some of the unique features of UAVs, such as their altitude and their ability to establish line-of-sight, will have significant impact on the way in which their trajectory is designed.

This chapter investigates a variety of scenarios involving cooperative communications for networks that incorporate UAVs. We particularly analyze the role of cooperative communications in improving the connectivity and capacity of cellular-connected UAV user equipmentleveraging principles ofcoordinated multi-point (CoMP) transmissions among ground base stations. We then study how one can effectively use multiple quadrotor UAVs as an aerial antenna array that acts as a single coordinated UAV base station to provide wireless service to ground users. The goal will be to maximize performance while minimizing the airborne service time for communication. We also characterize the optimal rotor's speed for minimizing the control time using theoretical postulates of bang-bang control theory.

This chapter provides a broad overview on several key applications and use cases of UAVs in various wireless networking scenarios. For the role of a UAV base station, we focus on the use of UAVs in a variety of applications, includingpublic safety, the Internet of Things, caching, edge computing, and smart cities. Then, we discuss a handful of important applications for UAV user equipment, and we show how these applications require UAV users to connect to ground cellular networks. While discussing the various applications, we also provide an in-depth exposition of the associated communications and networking challenges in each application.

This chapter provides a practical discussion on the integration of UAVs into real-world cellular systems, ranging from long-term evolution (LTE) to 5G new radio (NR) and beyond. We first review the roles of mobile cellular technologies for UAV applications while highlighting the use of mobile connectivity and the role of mobile cellular technologies in enabling the development of new services for UAVs in key areas such as identification and registration, location-based services, and law enforcement. Then, we discuss LTE-enabled UAVs in more detail, including a tutorial on LTE and the various UAV use cases that include UAV LTE user equipment and UAV LTE base stations. We also touch upon some performance enhancing solutions that can optimize LTE connectivity for providing improved performance for UAVs while protecting the performance of terrestrial mobile devices. We then introduce various 3GPP standardization efforts on cellular-connected UAVs that aim to address the anticipated usage of mobile technologies by UAVs and regulatory requirements. Next, we discuss 5G NR-enabled UAVs while providing a primer on 5G NR essentials, how 5G NR can provide superior UAV connectivity, and the roles of network slicing and network intelligence for identifying, monitoring, and controlling UAVs in the 5G era.