The JSAT constellation is a communication and broadcasting satellite constellation formerly operated by JSAT Corporation and currently by SKY Perfect JSAT Group. It has become the most important commercial constellation in Japan, and fifth in the world. It has practically amalgamated all private satellite operators in Japan, with only B-SAT left as a local competitor.[1][non-primary source needed]
JSAT began in 1985, with the opening by the Government of Japan, of the communication markets in Japan and the founding of Japan Communications Satellite Company, Satellite Japan Corporation, Space Communications Corporation. It grew by own investment, mergers and acquisitions of the parent companies. As of August 2016, it includes the fleets of three previously mentioned companies, Horizons Satellite and NTT DoCoMo and the DSN military network.[1]