The emergence of Fifth-Generation (5G) communication networks has brought forth unprecedented connectivity with ultra-low latency, high data rates, and pervasive coverage. However, meeting the increasing demands of applications for seamless and high-quality communication, especially in rural areas, requires exploring innovative solutions that expand 5G beyond traditional terrestrial networks. Within the context of Non-Terrestrial Networks (NTNs), two promising technologies with vast potential are High Altitude Platforms (HAPs) and satellites. The combination of these two platforms is able to provide wide coverage and reliable communication in remote and inaccessible areas, and/or where terrestrial infrastructure is unavailable. This study evaluates the performance of the communication link between a Geostationary Equatorial Orbit (GEO) satellite and a HAP using the Internet of Drones Simulator (IoD-Sim), implemented in ns-3 and incorporating the 3GPP TR 38.811 channel model. The code base of IoD-Sim is extended to simulate HAPs, accounting for the Earths curvature in various geographic coordinate systems, and considering realistic mobility patterns. A simulation campaign is conducted to evaluate the GEO-to-HAP communication link in terms of Signal-to-Noise Ratio (SNR) in two different scenarios, considering the mobility of the HAP, and as a function of the frequency and the distance.

翻译：第五代（5G）通信网络的出现带来了前所未有的超低延迟、高数据速率和广泛覆盖的互联能力。然而，为满足农村地区等场景对无缝高质量通信日益增长的需求，需要探索扩展5G超越传统地面网络的创新解决方案。在非地面网络（NTNs）背景下，高空平台（HAPs）和卫星是两项具有巨大潜力的技术。这两种平台的结合能够在偏远和难以到达的区域，以及/或地面基础设施缺失的区域，提供广泛覆盖和可靠通信。本研究利用基于ns-3实现并集成3GPP TR 38.811信道模型的无人机互联网模拟器（IoD-Sim），对地球静止轨道（GEO）卫星与HAP之间的通信链路进行了性能评估。扩展了IoD-Sim的代码库以模拟HAP，考虑了多种地理坐标系中的地球曲率，并纳入了实际移动模式。开展了一系列仿真实验，在两种不同场景下，考虑HAP的移动性，并作为频率和距离的函数，评估了GEO到HAP通信链路的信噪比（SNR）。