I. Introduction
The rapid development of mobile communication and Internet of things (IoT) technologies, coupled with the advancements in industrial manufacturing capabilities, has led to the widespread use of intelligent mobile devices such as mobile phones, wearable devices and sensor devices. However, these UEs face limitations in terms of their physical resources, residual energy, etc. [1], making it challenging for them to perform computationally intensive tasks, such as virtual reality, face recognition and building scanning analysis. Mobile edge computing (MEC) can effectively solve these problems by shifting services to edge servers that are close to UEs, such as cellular base stations, and providing diverse computation and storage services. Previous research on edge computing primarily focused on static edge servers that can handle most application requests. However, the coverage of static edge servers is inherently limited. Moreover, network infrastructures become unavailable in case of some natural disasters such as earthquakes and hurricanes [2], resulting in a faulty state where the infrastructure or communication link terminals are unable to serve mobile devices. Deploying a large number of edge servers exclusively for such scenarios would require significant resources, making it impractical [3]. In contrast, Unmanned Aerial Vehicles (UAVs) offer distinct advantages in mobility and adaptability. UAVs can be deployed to specific locations and navigate through various terrains, including wilderness, oceans, and deserts. By equipping UAVs with edge servers, edge computing systems can benefit from enhanced mobility, enabling edge servers to dynamically serve users in different locations and adapt to changing environmental conditions. Moreover, this paradigm provides a viable approach to extend the coverage of services beyond the limitations of static edge servers, making it particularly valuable in situations where network infrastructure is compromised or where specific mobility requirements arise.