Low-complexity optimization algorithm for ground network design in optical satellite networks

Free space optics (FSO) is considered a promising technology for satellite communications due to its various advantages over radio-frequency (RF) systems, such as higher throughput, lower energy consumption and smaller mass. Nevertheless, optical satellite communication systems are heavily affected by atmospheric impairments, mainly by clouds. In order to cope with cloud coverage, site diversity technique is employed at the expense of installing extra optical ground stations (OGSs). As a consequence, the interest in ground network optimization is rapidly increasing with the aim to guarantee a given service availability. In this paper, a low-complexity optimization algorithm for ground network design in optical geostationary (GEO) satellite systems is presented, taking into account the spatial correlation between sites. Specifically, the objective is to choose a group of candidate OGSs that minimizes the overall cost of the ground network and meets certain availability requirements for every time period (thus incorporating the temporal variability of cloud coverage). Moreover, an extension of the methodology to optical medium-Earth-orbit (MEO) satellite systems is provided. Lastly, the performance of the proposed algorithm is evaluated via numerical experiments.