  Unmanned aerial vehicles (UAVs) for wireless communications has rapidly grown
into a research hotspot as the mass production of high-performance, low-cost,
intelligent UAVs become more practical and feasible. In the meantime, fifth
generation (5G) wireless communications is being standardized and planned for
deployment globally. During this process, UAVs are gradually being considered
as an important part of 5G and expected to play a critical role in enabling
more functional diversity for 5G communications. In this article, we conduct an
in-depth investigation of mainstream UAV designs and state-of-the-art UAV
enabled wireless communication systems.We propose a hierarchical architecture
of UAVs with multi-layer and distributed features to facilitate a smooth
integration of different mainstream UAVs into the next-generation wireless
communication networks. Furthermore, we unveil the critical comprehensive
design tradeoffs, in light of both communication and aerodynamic principles.
Empirical models and satellite measurement data are used to conduct numerical
analysis of the meteorological impacts of UAV enabled, 5G high bands
communications.
