Low Earth Orbit Satellite Networks: Architecture, Key Technologies, Measurement, and Open Issues

Low Earth Orbit (LEO) satellite networks are transforming global connectivity by enabling high-speed, low-latency Internet access. Particularly, they significantly facilitate areas where terrestrial networks are not deployed or destroyed. Meanwhile, LEO satellite technology is experiencing an unprecedented surge in development. This paper provides a comprehensive and up-todate overview of LEO satellite networks. First, the evolution of LEO satellites is introduced, followed by an exploration of the components and communication architecture within LEO satellite networks using representative examples. Second, key technologies, including routing, handover management, and digital twins, are summarized, and some practical application scenarios are discussed. The performance of LEO satellite networks, illustrated by SpaceX’s Starlink, is then evaluated to understand its scheduling algorithm and network characteristics, which can inform future satellite-related algorithms and architecture design. Finally, as LEO constellations continue to expand, practical operations face significant challenges in management, technology, and security. Consequently, we highlight some open research issues to provide potential inspiration for academia and industry in satellite networking.