A Performance Study on Low Earth Orbit Satellite Networks with Inter Satellite Links

A network created with Low Earth Orbit (LEO) satellites has advantages, such as lower latencies and network equity to remote Internet regions. However, the inherent mobility of a LEO satellite network sets it apart from its terrestrial counterpart. Studying how LEO networks are structured and interconnected is essential for understanding the performance and efficiency of LEO network topologies. This paper explores the realm of LEO satellite networks created using Inter Satellite Links (ISL). We simulated three topologies: Sparse, +Grid, and Extended +Grid. We evaluated their performance on a major LEO satellite constellation and recorded key network characteristics. We assess the simplicity, hop count, latency, and stability (the count of total path changes over a 10-minute interval) of these connection strategies in simulated LEO networks. Our evaluations highlight that although the Sparse topology is simpler than the other two, it has a higher latency than the +Grid topology. Our results indicate that using an Extended +Grid topology over a +Grid topology can reduce hop count down to 50% in a LEO mega-constellation while using the same amount of ISL hardware. Although Sparse Topology shows similar hop count and stability results, its additional latency makes it less desirable to +Grid and Extended +Grid topologies. The trade-offs between these attributes and performance and reliability across diverse topologies in LEO satellite networks need further research.