LAMP: Low-Latency Dynamic Topology for LEO Satellite Constellations

In recent years, LEO satellite constellations have been used to solve many problems in communication, navigation, and observation, thanks to the low cost of launching satellites into LEO orbit and the low communication latency compared with GEO orbit. In order for LEO constellations to provide global coverage, the satellites must be able to communicate with each other, typically with a grid-like topology. In this work, we show that a static grid-like topology results in high communication latency. We propose the LEO Approximate Minimum Propagation delay (LAMP) topology, an alternative topology design method using dynamic links. The LAMP topology starts with a backbone network of persistent inter-satellite links to ensure connectivity in the constellation. Then, with the unused laser transceivers, temporary links are added such that the mean communication latency across the constellation is reduced. We show that with the LAMP topology, the average latency can be reduced by 18.5% compared to the static grid topology, and 5.61% compared to the existing Dynamic Topology of Satellites. Additionally, the LAMP topology has lower variability on mean propagation delay as the constellation parameters change compared to the static grid topology; regardless of constellation configuration, the mean propagation delay remains low.