ATC
Nations Act To Protect Their Satellite Industries
The biggest challenge to imagined interoperability could be governments protecting their own systems.

When ICAO introduced the Global Navigation Satellite System (GNSS) concept in 1993, it was to establish an earth-girdling network of navigation satellite constellations that would provide service “for the foreseeable future on a continuous worldwide basis, free of direct user fees.” The U.S. and Russia (then the Soviet Union) were first to sign up in 1996, followed several years later by Europe, China, Japan and India, which planned to launch constellations of their own. By 2020, there should be six constellations and close to 150 navigation satellites criss-crossing the Earth.