LEO卫星多跳网络更新的信息新鲜度
Information Freshness of Updates Sent over LEO Satellite Multi-Hop Networks
摘要：
低地球轨道（LEO）卫星星座正在将物联网（IoT）带入太空领域，也称为非地面网络。用于跟踪船舶和货物的几个物联网卫星应用可以被视为间歇性传输更新的示例，其主要性能参数是信息新鲜度。本文分析了信息时代（AoI）的卫星网络与多个源和目的地是非常遥远的，因此需要几个连续的多跳传输。考虑了数据包擦除信道和不同的擦除策略。我们提供了封闭形式的边界和严格的近似平均AoI，以及信息的峰值年龄（PAoI）分布的上限作为系统设计的最坏情况下的度量。性能评估揭示了复杂的权衡年龄，负载和数据包丢失。当到达率和分组丢失的组合使得系统负载可以确保接收器处的新鲜信息时，找到最佳操作点;然而，实现这一点高度依赖于网状拓扑。此外，年龄感知调度策略的潜力进行了调查和用户之间的公平性进行了讨论。结果表明，需要确定瓶颈节点的年龄，因为提高这些关键链路的速率和可靠性将极大地影响整体性能。该模型具有较强的通用性，可以用于其他多跳网状网络。
英文摘要：
Low Earth Orbit (LEO) satellite constellations are bringing the Internet of Things (IoT) to the space arena, also known as non-terrestrial networks. Several IoT satellite applications for tracking ships and cargo can be seen as exemplary cases of intermittent transmission of updates whose main performance parameter is the information freshness. This paper analyzes the Age of Information (AoI) of a satellite network with multiple sources and destinations that are very distant and therefore require several consecutive multi-hop transmissions. A packet erasure channel and different queueing policies are considered. We provide closed-form bounds and tight approximations of the average AoI, as well as an upper bound of the Peak Age of Information (PAoI) distribution as a worst-case metric for the system design. The performance evaluation reveals complex trade-offs among age, load, and packet losses. The optimal operational point is found when the combination of arrival rates and packet losses is such that the system load can ensure fresh information at the receiver; nevertheless, achieving this is highly dependent on the mesh topology. Moreover, the potential of an age-aware scheduling strategy is investigated and the fairness among users discussed. The results show the need to identify the bottleneck nodes for the age, as improving the rate and reliability of those critical links will highly impact on the overall performance. The model is general enough to represent other multi-hop mesh networks.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
