Optical Communications Through Low Orbit Satellites

Current societal needs demand for global high-speed networks. Toward this regard, 3GPP has included in its release 17 Non-Terrestrial Networks (NTN). In order to meet the strict requirements of 6G networks, Very Low Earth Orbit (VLEO) and Low Earth Orbit (LEO) satellites will play a key role. Optical fibers can also be used for transmitting data at high speeds. Unfortunately, the refraction index of the optical fibers and the satellite altitude penalize them. So, this paper determines the transmission distance for which it is better to use optical fiber or satellite links. For a fair comparison in terms of bandwidth, it has been assumed that the LEO/VLEO satellites should be optical too. After that an algorithm has been developed to determine the best suitable regions for locating the ground station of an optical satellite. Specifically, it computes the degree of cloudiness of a certain geographic region. Given that the determination of such regions demands a large computational burden, it has been parallelized using OpenMP libraries for Python. The Iberian Peninsula, which images were taken by the METEOSAT satellite from EUMETSAT, has been considered as a paradigmatic case of study.