The Internet of Things (IoT) is expected to bring new opportunities for improving several services for the Society, from transportation to agriculture, from smart cities to fleet management. In this framework, massive connectivity represents one of the key issues. This is especially relevant when IoT systems are expected to cover a large geographical area or a region not reached by terrestrial network connections. In such scenarios, the usage of satellites might represent a viable solution for providing wide area coverage and connectivity in a flexible and affordable manner. Our paper presents a survey on current solutions for the deployment of IoT services in remote/rural areas by exploiting satellites. Several architectures and technical solutions are analyzed, underlining their features and limitations, and real test cases are presented. It has been highlighted that low-orbit satellites offer an efficient solution to support long-range IoT services, with a good trade-off in terms of coverage and latency. Moreover, open issues, new challenges, and innovative technologies have been focused, carefully considering the perimeter that current IoT standardization framework will impose to the practical implementation of future satellite based IoT systems.

中文翻译：

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卫星物联网技术、标准和开放挑战调查

物联网 (IoT) 有望为改善社会的多项服务带来新机遇，从交通运输到农业，从智慧城市到车队管理。在这个框架中，大规模连接是关键问题之一。当物联网系统预计覆盖较大的地理区域或地面网络连接无法到达的区域时，这一点尤其重要。在这种情况下，卫星的使用可能代表以灵活且负担得起的方式提供广域覆盖和连接的可行解决方案。我们的论文对当前通过利用卫星在偏远/农村地区部署物联网服务的解决方案进行了调查。分析了几种架构和技术解决方案，强调了它们的特性和局限性，并提供了真实的测试用例。已经强调，低轨道卫星提供了一种有效的解决方案来支持远程物联网服务，并在覆盖范围和延迟方面进行了很好的权衡。此外，还关注开放性问题、新挑战和创新技术，仔细考虑当前物联网标准化框架将对未来基于卫星的物联网系统的实际实施施加的边界。