Even though achieving global connectivity represents one of the main goals of 5G and beyond wireless networks, exurban areas are still suffering frequent outages because of the lack of proper telecom infrastructures, which are often available only in urban areas. Indeed, cellular network design is usually capacity driven, and thus the densities of base stations (BSs) follow mostly population and especially revenue densities. Contextually, we focus on one of the most promising solutions to provide sufficient and reliable coverage in far-flung areas: aerial base stations (ABSs), which consist of unmanned aerial vehicles (UAVs) carrying cellular BS equipment. In this article, we extensively discuss the problem of bridging what is called the urban–rural digital divide (i.e., the connectivity gap between urban and rural areas) from various perspectives. First, we showcase various alternative solutions and compare conventional terrestrial networks with aerial networks from a techno-economic point of view. Then, we highlight the topological aspects of rural environments and explain how they can affect the actual design of cellular networks. In addition, we investigate both the coverage probability and the reliability of the communication links via simulations, proving that the integration of ABSs can be quite promising in a 6G perspective. Finally, we propose two original extensions of our case study as open problems.

中文翻译：

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用于全球连接的空中基站：这是一个可行且可靠的解决方案吗？

尽管实现全球连接是 5G 及其他无线网络的主要目标之一，但由于缺乏适当的电信基础设施（通常只有城市地区才有），远郊地区仍然经常遭受中断的困扰。事实上，蜂窝网络设计通常是容量驱动的，因此基站（BS）的密度主要遵循人口密度，尤其是收入密度。从具体情况来看，我们专注于在偏远地区提供充分可靠的覆盖的最有前途的解决方案之一：空中基站（ABS），由携带蜂窝基站设备的无人机（UAV）组成。在本文中，我们广泛讨论了桥接问题从不同角度审视城乡数字鸿沟（即城乡之间的互联互通差距）。首先，我们展示各种替代解决方案，并从技术经济的角度比较传统地面网络与空中网络。然后，我们重点介绍农村环境的拓扑方面，并解释它们如何影响蜂窝网络的实际设计。此外，我们还通过仿真研究了通信链路的覆盖概率和可靠性，证明从 6G 的角度来看，ABS 的集成非常有前景。最后，我们提出了案例研究的两个原始扩展作为开放问题。