Distributed Multi-objective Topology Optimization Method in VLEO-LEO Satellite Networks

Kai Han, Bingbing Xu, Marie Siew, Wenbin Gong, Tony Q. S. Quek, Qianyi Ren

Abstract: Given the crucial role of the earth observation satellites in numerous key applications, accessing the Low Earth Orbit (LEO) satellite Internet via Laser Inter-Satellite Links (LISLs) has emerged as a promising solution to help transmit substantial amounts of observation data to ground stations. For Very Low Earth Orbit (VLEO) observation satellites, optimizing the inter-layer topology between themselves and LEO communication satellites has become paramount. To mitigate existing centralized algorithms’ reliance on global data transfer requirement information, a Novel Distributed Interactive Mechanism (NDIM) for inter-layer LISLs establishment is proposed. Here, the VLEO observation satellite decides its own access strategy based on local network information gleaned from three information exchanges with the LEO communication satellite. Additionally, considering the transmission requirements of observation satellites and the remaining load of communication satellites, a multi-objective topology optimization model is formulated, leading to the proposal of a Distributed Multi-objective inter-layer Topology Optimization (DMTO) algorithm. Our algorithm is novel in considering the remaining loads of the intermediary communication satellites, and it allows for the transmission of streaming observation data. We perform simulations using real task data (from Typhoon LEKIMA), and our results show that DMTO improves over existing baselines in terms of observation data throughput and communication satellite load balancing.