  In existing computing systems, such as edge computing and cloud computing,
several emerging applications and practical scenarios are mostly unavailable or
only partially implemented. To overcome the limitations that restrict such
applications, the development of a comprehensive computing paradigm has
garnered attention in both academia and industry. However, a gap exists in the
literature owing to the scarce research, and a comprehensive computing paradigm
is yet to be systematically designed and reviewed. This study introduces a
novel concept, called aerial computing, via the amalgamation of aerial radio
access networks and edge computing, which attempts to bridge the gap.
Specifically, first, we propose a novel comprehensive computing architecture
that is composed of low-altitude computing, high-altitude computing, and
satellite computing platforms, along with conventional computing systems. We
determine that aerial computing offers several desirable attributes: global
computing service, better mobility, higher scalability and availability, and
simultaneity. Second, we comprehensively discuss key technologies that
facilitate aerial computing, including energy refilling, edge computing,
network softwarization, frequency spectrum, multi-access techniques, artificial
intelligence, and big data. In addition, we discuss vertical domain
applications (e.g., smart cities, smart vehicles, smart factories, and smart
grids) supported by aerial computing. Finally, we highlight several challenges
that need to be addressed and their possible solutions.
