Tondo Felipe Augusto, Montejo-Sánchez Samuel, Pellenz Marcelo Eduardo, Céspedes Sandra, Souza Richard Demo
Department of Electrical and Electronics Engineering, Federal University of Santa Catarina, Florianópolis 88040-900, Brazil.
Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación, Universidad Tecnológica Metropolitana, Santiago 8940577, Chile.
Sensors (Basel). 2021 Oct 26;21(21):7099. doi: 10.3390/s21217099.
Direct-to-satellite Internet of Things (IoT) solutions have attracted a lot of attention from industry and academia recently, as promising alternatives for large scale coverage of a massive number of IoT devices. In this work, we considered that a cluster of IoT devices was under the coverage of a constellation of low-Earth orbit (LEO) satellites, while slotted Aloha was used as a medium access control technique. Then, we analyzed the throughput and packet loss rate while considering potentially different erasure probabilities at each of the visible satellites within the constellation. We show that different combinations of erasure probabilities at the LEO satellites and the IoT traffic load can lead to considerable differences in the system's performance. Next, we introduce an intelligent traffic load distribution (ITLD) strategy, which, by choosing between a non-uniform allocation and the uniform traffic load distribution, guarantees a high overall system throughput, by allocating more appropriate amounts of traffic load at different positions (i.e., different sets of erasure probabilities) of the LEO constellation with respect to the IoT cluster. Finally, the results show that ITLD, a mechanism with low implementation complexity, allows the system to be much more scalable, intelligently exploiting the potential of the different positions of the satellite constellation.
直接面向卫星的物联网（IoT）解决方案最近引起了业界和学术界的广泛关注，有望成为大规模覆盖大量物联网设备的替代方案。在这项工作中，我们考虑了一群物联网设备处于低地球轨道（LEO）卫星星座的覆盖范围内，同时采用时隙Aloha作为介质访问控制技术。然后，我们在考虑星座内每个可见卫星可能存在不同擦除概率的情况下，分析了吞吐量和丢包率。我们表明，LEO卫星的擦除概率和物联网流量负载的不同组合会导致系统性能出现显著差异。接下来，我们引入一种智能流量负载分配（ITLD）策略，该策略通过在非均匀分配和均匀流量负载分配之间进行选择，通过在LEO星座相对于物联网集群的不同位置（即不同的擦除概率集）分配更合适的流量负载量，保证了较高的整体系统吞吐量。最后，结果表明，ITLD这种实现复杂度较低的机制使系统具有更高的可扩展性，能够智能地利用卫星星座不同位置的潜力。
