Energy-efficient routing algorithm based on intersatellite traffic-awareness in hybrid RF/FSO satellite communication networks

Low Earth Orbit (LEO) optical satellite networks are central to integrated space-ground systems, offering low latency and wide coverage. However, frequent charge-discharge cycles during satellite shadow periods hasten battery degradation and limit network lifespan. To address this, we propose an energy-efficient traffic-aware (EE-TA) routing algorithm by utilizing hybrid RF/FSO communication technology. EE-TA deploys additional microwave links on intra-orbit laser connections, enabling satellites in sunlight to handle traffic for neighboring satellites in shadow. This offloading reduces battery strain and extends operational lifetimes. Simulations with a 288-satellite Walker-Star constellation show that EE-TA lowers overall lifespan consumption by 5% at the cost of only a 0.52% increase in blockage rate.