Non-terrestrial networks (NTNs) are considered one of the key enablers in sixth-generation (6G) wireless networks; and with their rapid growth, system-level metrics analysis adds crucial understanding into NTN system performance. Applying stochastic geometry (SG) as a system-level analysis tool in the context of NTN offers novel insights into the network tradeoffs. In this paper, we study and highlight NTN common system-level metrics from three perspectives: NTN platform types, typical communication issues, and application scenarios. In addition to summarizing existing research, we study the best-suited SG models for different platforms and system-level metrics which have not been well studied in the literature. In addition, we showcase NTN-dominated prospective application scenarios. Finally, we carry out a performance analysis of system-level metrics for these applications based on SG models.
Stochastic Geometry Based Modelling and Analysis of Uplink Cooperative Satellite-Aerial-Terrestrial Networks for Nomadic Communications with Weak Satellite Coverage
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。
Reinforcement Learning for Opportunistic Routing in Software-Defined LEO-Terrestrial Systems
School of Electrical and Mechanical Engineering, University of Adelaide（阿德莱德大学电气与机械工程学院）；Singapore University of Technology and Design（新加坡科技设计大学）；Electronics and Telecommunications Research Institute（电子电信研究院）
Age of Information in Non-Terrestrial Networks with Energy Harvesting
ZJU-UIUC Institute, Zhejiang University（浙江大学中法联合学院）；Department of Computer and Information Science, Linkoping University（林雪平大学计算机与信息科学系）；National Mobile Communications Research Laboratory, Southeast University（东南大学移动通信国家重点实验室）
