Today, 5G networks are being worldwide rolled out, with significant benefits in our economy and society. However, 5G systems alone are not expected to be sufficient for the challenges that 2030 networks will experience, including, e.g., always-on networks, 1 Tbps peak data rate, <10 cm positioning, etc. Thus, the definition of evolutions of the 5G systems and their (r)evolutions are already being addressed by the scientific and industrial communities, targeting 5G-Advanced (5G-A) and 6G. In this framework, Non-Terrestrial Networks (NTN) have successfully been integrated in 3GPP Rel. 17 and it is expected that they will play an even more pivotal role for 5G-A (up to Rel. 20) and 6G systems (beyond Rel. 20). In this paper, we explore the path that will lead to 5G-A and 6G NTN communications, providing a clear perspective in terms of system architecture, services, technologies, and standardisation roadmap.
Proactive TCP mechanism to improve Handover performance in Mobile Satellite and Terrestrial Networks
正在出现的用于卫星系统的Geo Mobile Radio（GMR-1）的标准化在上层协议层与地面GSM（全球移动通信系统）具有很强的相似性，TCP（传输控制协议）是其中之一。这种空间段技术以及地面技术的特征在于通信特性和覆盖范围的周期性变化，当移动节点（MN）的连接改变随机性时，导致正在进行的呼叫的终止。虽然规定提供有效的通信基础设施，这种混合空间和地面网络必须确保端到端的网络性能，使MN可以在这些网络之间无缝移动。然而，从连接性的角度来看，当前的TCP性能还没有被设计用于多无线电MN中的移动性事件。传统上，TCP采用一套拥塞控制算法（慢启动、拥塞避免、快速拥塞、快速恢复）来探测连接路径上的当前可用带宽，这些算法需要多次往返才能找到正确的传输速率（即拥塞窗口），并适应切换引起的连接性突变。虽然有一些协议，如移动IP（MIP）和主机身份协议（HIP），以保持连接的连续性的移动性事件，TCP性能工程的关注较少。TCP被实现为操作系统中的单独组件，因此通常不知道移动性事件或多无线电通信的性质。本文旨在提高TCP在移动卫星和地面网络中的通信性能。
Enabling Intelligent Vehicular Networks Through Distributed Learning in the Non-Terrestrial Networks 6G Vision
Alma Mater Studiorum - Università di Bologna（博洛尼亚大学）；Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”（古列尔莫·马可尼电气、电子与信息工程系）
Advancing Fluid Antenna-Assisted Non-Terrestrial Networks in 6G and Beyond: Fundamentals, State of the Art, and Future Directions
Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高等研究院）；University of Chinese Academy of Sciences（中国科学院大学）；Shenzhen CyberAray Network Technology Co., Ltd.（深圳赛博阵列网络技术有限公司）；School of Telecommunication and Information Engineering, Nanjing University of Posts and Telecommunications（南京邮电大学通信与信息工程学院）；Department of Electronic Engineering, Shanghai Jiao Tong University（上海交通大学电子工程系）；School of Electronics and Information Technology (School of Microelectronics), Sun Yat-sen University（中山大学电子与信息技术学院（微电子学院））；Graduate School of Informatics and Engineering, The University of Electro-Communications（电气通信大学信息工学研究科）；Department of Electronic and Electrical Engineering, University College London（伦敦大学学院电子电气工程系）；Department of Electronic Engineering, Kyung Hee University（庆熙大学电子工程系）
