Multi­level model of terrestrial and non­terrestrial telecommunications using optical wireless technologies

Abstract

Non-terrestrial communication technologies will become a key component for the development of future 6th generation (6G) networks. Potentials, implementation prospects, problems and solutions for non-terrestrial telecommunications remain open areas for future research. The article discusses the use of millimeter and optical wavelengths in various configurations of multilevel space communications using LEO satellites, stratospheric platforms and unmanned repeaters. Wireless communication in MMW and OR has great potential for use in space communication systems. These technologies have the advantages of using azimuth line-of-sight channels in comparison with terrestrial ones. For example, the total zenith attenuation can be much less than the linear attenuation in the lower atmosphere. It also has advantages in terms of reconfiguration virtuality, coverage area and energy (spectral) efficiency. A sudden drop in communication quality due to atmospheric phenomena, including severe atmospheric turbulence, leads to the need for adaptive dynamic beam steering, which also leads to a decrease in the use of resources, both frequency and energy. Wireless and fiber optic communication systems have similarities in the operating wavelength range, processing methods. The methods of radio-photonics can be applied to wireless communication systems, where the technology of converting radio waves into optical, including the terahertz range, can be used. The comparison of the capacity of the Shannon channel for various multi-level scenarios of the satellite communication line is carried out. The directions of research to ensure the continuity of communication, adaptation to weather conditions, and the achievement of throughput up to 100 Gbit/s are analyzed.