The huge prospects of the internet of things (IoT) have led to an ever-growing demand for computing power by IoT users to enable various applications. Multi-access edge computing (MEC) research and development has rapidly gained attention during the last decade. The ability to deploy edge servers at different points across a content delivery network that can offer communication and computing services close to mobile user devices is one of the main factors driving the evolution of MEC. Furthermore, MEC has been considered a potentially transformational approach for fifth-generation (5 G) and beyond 5 G (B5G) networks, as well as a potential improvement to conventional cloud computing. Unmanned aerial vehicles (UAVs) can be used as effective aerial platforms to offer reliable and ubiquitous connections in wireless communication networks due to their distinctive qualities, such as high cruising altitude, on-demand deployment, and three-dimensional (3D) maneuverability. The number of research studies published in this area has dramatically increased due to the growing interest in UAV-enabled MEC. Although UAV-enabled MEC systems have been well studied, the existing models are becoming increasingly heterogeneous and scattered without harmony. This paper provides a comprehensive analysis of the literature on UAV-enabled MEC systems with a special focus on the system modeling, and optimization techniques for five identified domains, such as energy efficiency, resource allocation, trajectory control, latency, and security. For each domain, we have highlighted the recent advances, critical findings, and the advantages and disadvantages. Additionally, the identified proposed techniques were analyzed and discussed, with emphasize on the constraints and performance metrics. We also discuss a general system model for each highlighted domain. Moreover, the lessons are also derived from the study on system optimization and system modeling techniques identified in this paper. Then we discuss open issues related to UAV-enabled MEC systems in each highlighted domain, including problem formulation and optimization techniques. Finally, this paper lay out directions for future research to solve the aforementioned problems associated with UAV-enabled MEC systems.

中文翻译：

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无人机 MEC 系统的基本设计方面：模型、挑战和未来机遇回顾

物联网（IoT）的巨大前景导致物联网用户对计算能力的需求不断增长，以实现各种应用。多接入边缘计算（MEC）的研究和开发在过去十年中迅速受到关注。在内容交付网络的不同点部署边缘服务器的能力，可以提供靠近移动用户设备的通信和计算服务，是推动 MEC 发展的主要因素之一。此外，MEC 被认为是第五代 (5G) 及超 5G (B5G) 网络的潜在变革方法，也是对传统云计算的潜在改进。无人机（UAV）因其独特的品质，例如高巡航高度、按需部署和三维（3D）机动性，可以用作有效的空中平台，在无线通信网络中提供可靠且无处不在的连接。由于人们对无人机 MEC 的兴趣日益浓厚，该领域发表的研究数量急剧增加。尽管无人机MEC系统已经得到了很好的研究，但现有的模型正变得越来越异构和分散，不和谐。本文对无人机 MEC 系统的文献进行了全面分析，特别关注能源效率、资源分配、轨迹控制、延迟和安全等五个确定领域的系统建模和优化技术。对于每个领域，我们重点介绍了最新进展、关键发现以及优点和缺点。此外，还分析和讨论了已确定的提议技术，重点是约束和性能指标。我们还讨论了每个突出显示领域的通用系统模型。此外，本文还从系统优化和系统建模技术的研究中得出了教训。然后，我们讨论每个突出领域中与无人机支持的 ​​MEC 系统相关的开放问题，包括问题表述和优化技术。最后，本文提出了未来研究的方向，以解决上述与无人机 MEC 系统相关的问题。