Non-terrestrial networks (NTNs) traditionally have certain limited applications. However, the recent technological advancements and manufacturing cost reduction opened up myriad applications of NTNs for 5G and beyond networks, especially when integrated into terrestrial networks (TNs). This article comprehensively surveys the evolution of NTNs highlighting their relevance to 5G networks and essentially, how it will play a pivotal role in the development of 6G ecosystem. We discuss important features of NTNs integration into TNs and the synergies by delving into the new range of services and use cases, various architectures, technological enablers, and higher layer aspects pertinent to NTNs integration. Moreover, we review the corresponding challenges arising from the technical peculiarities and the new approaches being adopted to develop efficient integrated ground-air-space (GAS) networks. Our survey further includes the major progress and outcomes from academic research as well as industrial efforts representing the main industrial trends, field trials, and prototyping towards the 6G networks.
翻译:然而,最近的技术进步和制造成本的降低为5G网络和5G网络以外的网络打开了许多NTN应用软件,特别是在融入地面网络时。本文章全面调查了NTN的演变情况,突出了它们与5G网络的相关性,基本上说明了它在6G生态系统的发展中将如何发挥关键作用。我们讨论了NTN融入TN的重要特点和协同作用,具体方法是深入到与NTN一体化有关的新的服务和使用案例、各种建筑、技术促进器和更高层方面。此外,我们审查了技术特点产生的相应挑战,以及为发展高效的综合性地空空间网络而正在采用的新办法。我们的调查还进一步包括学术研究的主要进展和成果,以及代表6G网络的主要工业趋势、实地试验和原型的工业努力。