Satellite networks (SNs) have emerged as a key enabler to provide global, ubiquitous and seamless Internet of Things (IoT) services in a flexible and affordable manner. Different from conventional delay-tolerant tasks, many intelligent IoT services are delay-sensitive, requiring scheduling methods to make fast decisions on dynamic computing and communication resource allocation. However, existing satellite networking technologies adopt store-carry-forward data transmission mechanism, and ignore the timely processing requirements of IoT applications, which can incur unacceptable latency and is not applicable for delay-sensitive scenarios. This article investigates the time-deterministic networking strategy for real-time IoT applications over SNs. We first introduce the overall satellite-based IoT architecture, and discuss its key technologies in terms of time-varying network representation and time-deterministic routing. We construct the time-varying graph to precisely depict dynamic topologies, diversified functions, computing and communication resources and resource reservations in SNs by designing the enhanced snapshot division mechanism. Then, we propose time-deterministic routing schemes for both the on-satellite computing IoT applications and data-intensive IoT services, and provide corresponding evaluations. Finally, we discuss the future research directions of the satellite-based IoT.

中文翻译：

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基于卫星的物联网服务的时间确定性网络：架构、关键技术和未来方向


卫星网络 (SN) 已成为以灵活且经济实惠的方式提供全球、无处不在且无缝的物联网 (IoT) 服务的关键推动者。与传统的延迟容忍任务不同，许多智能物联网服务对延迟敏感，需要调度方法对动态计算和通信资源分配做出快速决策。然而，现有的卫星网络技术采用存储-结转的数据传输机制，忽略了物联网应用的及时处理要求，这会导致不可接受的延迟，不适用于延迟敏感的场景。本文研究了基于 SN 的实时物联网应用的时间确定性网络策略。我们首先介绍基于卫星的物联网整体架构，并讨论其时变网络表示和时间确定性路由方面的关键技术。通过设计增强的快照划分机制，构建时变图来精确描述SN中的动态拓扑、多样化功能、计算和通信资源以及资源预留。然后，我们针对卫星计算物联网应用和数据密集型物联网服务提出时间确定性路由方案，并提供相应的评估。最后，我们讨论了星基物联网的未来研究方向。