High altitude platform station (HAPS), which is deployed in the stratosphere at an altitude of 20-50 kilometres, has attracted much attention in recent years due to their large footprint, line-of-sight links, and fixed position relative to the Earth. Compared with existing network infrastructure, HAPS has a much larger coverage area than terrestrial base stations and is much closer than satellites to the ground users. Besides small-cells and macro-cells, a HAPS can offer one mega-cell, which can complement legacy networks in 6G and beyond wireless systems. This paper explores potential use cases and discusses relevant open challenges of integrating HAPS into legacy networks, while also suggesting some solutions to these challenges. The cumulative density functions of spectral efficiency of the integrated network and cell-edge users are studied and compared with terrestrial network. The results show the capacity gains achieved by the integrated network are beneficial to cell-edge users. Furthermore, the advantages of a HAPS for backhauling aerial base stations are demonstrated by the simulation results.

翻译：高空平台站（HAPS）部署在距地面20-50公里的平流层中，因其覆盖范围广、具备视距链路且相对于地球位置固定，近年来受到广泛关注。与现有网络基础设施相比，HAPS的覆盖面积远大于地面基站，同时又比卫星更接近地面用户。除小蜂窝和宏蜂窝外，HAPS可提供一种巨型蜂窝，能够补充6G及未来无线通信系统中的传统网络。本文探讨了将HAPS集成至传统网络的潜在用例及相关开放挑战，并针对这些挑战提出了若干解决方案。通过研究集成网络及小区边缘用户频谱效率的累积分布函数，并与地面网络进行对比，结果表明集成网络实现的容量增益对小区边缘用户尤为有利。此外，仿真结果验证了HAPS在回传空中基站方面的优势。