Dedicated Protection Based on Spatial-Temporal SRLG in Optical Satellite Networks

With the expansion of low Earth orbit satellite constellations, optical satellite networks are playing an increasingly important role. One significant issue in optical satellite networks is the frequent laser link failures and corresponding service interruptions. To reduce the possibility of service interruption that is caused by inter-satellite laser link failures, we propose a spatial-temporal shared risk link group (ST-SRLG) model that considers simultaneous link failure risks in both spatial and temporal dimensions. Based on the ST-SRLG model, a dedicated path protection algorithm is proposed to provision backup path that can still survive in case of primary path failures. Simulation results demonstrate that this algorithm can reduce the service interruption rate by 74.03%, thereby enhancing the overall reliability and stability of optical satellite networks.