  The growing use of Unmanned Aerial Vehicles (UAVs) for various applications
requires ubiquitous and reliable connectivity for safe control and data
exchange between these devices and ground terminals. Depending on the
application, UAV-mounted wireless equipment can either be an aerial user
equipment (AUE) that co-exists with the terrestrial users, or it can be a part
of wireless infrastructure providing a range of services to the ground users.
For instance, AUE can be used for real-time search and rescue and Aerial Base
Station (ABS) can enhance coverage, capacity and energy efficiency of wireless
networks. In both cases, UAV-based solutions are scalable, mobile, fast to
deploy. However, several technical challenges have to be addressed. In this
work, we present a tutorial on wireless communication with UAVs, taking into
account a wide range of potential applications. The main goal of this work is
to provide a complete overview of the main scenarios (AUE and ABS), channel and
performance models, compare them, and discuss open research points. This work
gives a comprehensive overview of the research done until now and depicts a
comprehensive picture to foster new ideas and solutions while avoiding
duplication of past work. We start by discussing the open challenges of
wireless communication with UAVs. To give answers to the posed questions, we
focus on the UAV communication basics, mainly providing the necessary channel
modeling background and giving guidelines on how various channel models should
be used. Next, theoretical, simulation- and measurement-based approaches, to
address the key challenges for AUE usage, are presented. Moreover, in this
work, we aim to provide a comprehensive overview on how UAV-mounted equipment
can be used as a part of a communication network. Based on the theoretical
analysis, we show how various network parameters can be optimized.
