The ability to intercept communications depends on the medium used, be it radio, satellite, microwave, cellular or fiber-optic. During World War II and through the 1950s, high-frequency ("short-wave") radio was widely used for military and diplomatic communication and could be intercepted at great distances. The rise of geostationary communications satellites in the 1960s presented new possibilities for intercepting international communications. In 1964, plans for the establishment of the ECHELON network took off after dozens of countries agreed to establish the International Telecommunications Satellite Organisation (Intelsat), which would own and operate a global constellation of communications satellites.