Abstract
In recent years, owing to demands from national security requirements and the Earth observation market,
the technological development of intersatellite optical communication network systems capable of
high-capacity and low-latency communications has been actively advanced in both the public and private
sectors. This paper reviews the trends in projects independently developed by the governments of Japan,
the United States, and Europe, as well as the movements of private companies such as SpaceX and
Amazon, that surpass government projects in momentum. Additionally, this paper discusses recently developed
technologies for multi-protocol optical communication networks and the multi-orbit concept.
