发表机构
University of Science and Technology of China; Southern University of Science and Technology; University of Luxembourg; Shanghai Jiao Tong University, China（中国科学技术大学; 南方科技大学; 卢森堡大学; 上海交通大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究首次对 NB-IoT NTN 在 GEO 上的性能进行实测分析，发现其处于初始阶段，PSM 重塑流量模式，并提出优化方案降低延迟和能耗。
AI 中文摘要
随着非地面网络（NTN）标准化以向大规模、低功耗物联网（IoT）设备提供直接卫星连接，3GPP IoT-NTN 将蜂窝通信与卫星通信的世界连接起来。尽管 IoT-NTN 在实现物联网设备全球连接方面潜力巨大，但对其在地球静止轨道（GEO）上的系统性能仍存在若干担忧，这些担忧涵盖多个维度，例如考虑到地面物联网终端到 GEO 卫星的超长传输距离而产生的端到端延迟和能耗。为解答这些担忧，我们首次对 NB-IoT NTN 在 GEO 上进行了全面深入的测量。基于包括 Skylo 和天通在内的真实 NB-IoT NTN 测试平台，覆盖超过六个月的测量证实，现有 NB-IoT NTN 实现仍处于初始阶段。由于地面物联网终端与 GEO 卫星之间的超长往返时间（RTT）被放大，接入过程中存在大量时间和能量消耗。有趣的是，测量还揭示，作为一种节能机制，省电模式（PSM）从根本上将 NB-IoT NTN 流量重塑为突发性且由接入驱动的通信模式，从而对端到端延迟和能耗产生显著影响。最后，我们提出了相应的优化方案以减少延迟和能耗，这为 NB-IoT NTN 在不久的将来的实施奠定了良好基础。
英文摘要
With the standardization of Non-Terrestrial Networks (NTN) to provide direct satellite connectivity to massive, low-power Internet of Things (IoT) devices, 3GPP IoT-NTN bridges the worlds of cellular and satellite communications. While holding great potential for global connectivity with IoT devices, there exist several concerns about the system performance of IoT-NTN over Geostationary Earth Orbit (GEO), which covers multiple dimensions such as end-to-end delay and energy consumption considering the ultra-long transmission distance from ground IoT terminals to GEO satellite. To answer these concerns, we have conducted the first comprehensive and in depth measurement for NB-IoT NTN over GEO. Based on real NB-IoT NTN testbeds including both Skylo and Tiantong, measurements covering more than six months confirm that the available implementation of NB-IoT NTN remains in the initial stage. Amplified by ultra-long Round-Trip Time (RTT) between ground IoT terminals and GEO satellite, there exists plenty of time and energy consumption during the access process. Interestingly, it also reveals that as an energy-saving mechanism, Power Saving Mode (PSM) fundamentally reshapes NB-IoT NTN traffic into a bursty and access-driven communication pattern and thus has a considerable influence on the end-to-end delay and energy consumption. Finally, we propose corresponding optimization schemes to reduce the delay and energy, which lays a good foundation for the implementation of NB-IoT NTN in the near future.
Comments15 pages, 21 figures
