This work evaluates the potential of High-Altitude Platform Stations (HAPS) and Low Earth Orbit (LEO) satellites as alternative or complementary systems to enhance Internet of Things (IoT) connectivity. We first analyze the transmission erasure probability under different connectivity configurations, including only HAPS or LEO satellites, as well as hybrid architectures that integrate both aerial/spatial and terrestrial infrastructures. To make the analysis more realistic, we considered movement of LEO satellites regarding a fixed region, elevation angle between gateway and devices, and different fading models for terrestrial and non-terrestrial communication. We also analyze LR-FHSS (Long-Range Frequency Hopping Spread Spectrum) random access uplink technology as a potential use case for IoT connectivity, showing the scalability impact of the scenarios. The simulation results demonstrate that HAPS can effectively complement sparse terrestrial networks and improve the performance of satellite-based systems in specific scenarios. Furthermore, considering the deployment and operational costs, respectively, CAPEX and OPEX, the economic analysis reveals that although HAPS exhibits higher costs, these remain within a comparable order of magnitude to LEO and terrestrial deployments. In addition, specific use cases, such as natural disasters, transform HAPS into a competitive technology for conventional infrastructures.

翻译：本研究评估了高空平台站与低地球轨道卫星作为替代或补充系统以增强物联网连接能力的潜力。我们首先分析了不同连接配置下的传输擦除概率，包括仅使用高空平台站或低地球轨道卫星的方案，以及融合空天与地面基础设施的混合架构。为使分析更贴近实际，我们考虑了低地球轨道卫星相对于固定区域的运动、网关与设备间的仰角，以及地面与非地面通信的不同衰落模型。同时，我们以LR-FHSS随机接入上行链路技术作为物联网连接的潜在用例，展示了各场景的可扩展性影响。仿真结果表明，高空平台站能有效补充稀疏的地面网络，并在特定场景中提升卫星系统的性能。此外，通过分别考虑部署成本与运营成本（即资本性支出与运营性支出），经济分析揭示：尽管高空平台站成本较高，但仍与低地球轨道及地面部署保持在相近数量级。值得注意的是，在自然灾害等特定应用场景中，高空平台站可转变为相较于传统基础设施更具竞争力的技术方案。