The Road to High Data Rates in Space: Terahertz Versus Optical Wireless Communication

With the ultimate vision of ubiquitous egalitarian worldwide coverage, private companies are launching satellite constellations at unprecedented rates. The large projected traffic in orbital cross-link communication will demand more spectrum to suit more users and to satisfy higher data rates. In this article, terahertz and optical wireless communication technologies are explored as the two projected high-data-rate cross-link communication technologies and are compared in terms of device technology capabilities and wireless propagation properties. A performance analysis including a link budget directly compares the two technologies for space communication in low Earth orbit constellations. More importantly, a roadmap is provided paving the way to push both ultrabroadband wireless technologies forward.