Choosing the Right Spot: How Well Are LEO Satellite Gateways Placed? Starlink Case-Study

This paper explores the optimisation of gateway (GW) placements within Low Earth Orbit (LEO) satellite networks, focusing on enhancing network performance metrics such as latency and hop count. Utilising a modified variant of the K-means algorithm termed Geo K-means, we analysed the current Starlink GW distribution and proposed a strategic placement model that aligns GW locations with user density. Results demonstrate that strategic GW placement, informed by user population density and utilising a hybrid architecture of bent-pipe and inter-satellite links (ISLs), significantly improves network performance, decreasing latency by 86% on average for user terminals across the globe, even when using only half the number of gateways deployed by Starlink. Our optimised GW placements connect more user terminals through direct bent-pipe connections, requiring less reliance on ISLs. ISLs increase the reach of Starlink gateways but at the expense of higher hop counts and can therefore increase latency by up to 5x compared to a bent-pipe connection to a nearby GW, highlighting the importance of strategic GW placement in LEO satellite megaconstellations, especially when relying on ISLs.