Low Earth Orbit (LEO) satellite networks are rapidly gaining traction today. Although several real-world deployments exist, our preliminary analysis of LEO topology performance with the soon-to-be operational Inter-Satellite Links (ISLs) reveals several interesting characteristics that are difficult to explain based on our current understanding of topologies. For example, a real-world satellite shell with a low density of satellites offers better latency performance than another shell with nearly double the number of satellites. In this work, we conduct an in-depth investigation of LEO satellite topology design parameters and their impact on network performance while using the ISLs. In particular, we focus on three design parameters: the number of orbits in a shell, the inclination of orbits, and the number of satellites per orbit. Through an extensive analysis of real-world and synthetic satellite configurations, we uncover several interesting properties of satellite topologies. Notably, there exist thresholds for the number of satellites per orbit and the number of orbits below which the latency performance degrades significantly. Moreover, network delay between a pair of traffic endpoints depends on the alignment of the satellite's orbit (Inclination) with the geographic locations of endpoints.

翻译：低地球轨道（LEO）卫星网络如今正迅速受到关注。尽管已存在若干实际部署案例，但我们对即将投入使用的星间链路（ISLs）下LEO拓扑性能的初步分析揭示了若干有趣特性，这些特性难以基于当前对拓扑的理解加以解释。例如，一个卫星密度较低的现实卫星壳层，其延迟性能优于另一个卫星数量近乎翻倍的壳层。在本研究中，我们针对使用ISLs的LEO卫星拓扑设计参数及其对网络性能的影响展开深入探究。具体而言，我们聚焦于三个设计参数：壳层中的轨道数量、轨道倾角以及每条轨道上的卫星数量。通过对现实与合成卫星配置的广泛分析，我们发现卫星拓扑的若干有趣特性。值得注意的是，每条轨道上的卫星数量与轨道数量均存在阈值——低于该阈值时延迟性能会显著恶化。此外，业务端点间的网络延迟取决于卫星轨道倾角与端点地理位置的匹配程度。