Probably Russian supplied GPS units.,...or Chinese.,...
Chinese manufactured, Japanese designed, or even US designed. They are by now a commerical commodity, or near to it. The GPS set is just a specialized receiver and computer. It's the satellite constellation that is either US (GPS) or Russian (GLONASS). Small differences in the details of the signals from the satellites, but not so much that a single unit can't work with either. But the Satellites just broadcast, you don't anyone's permission or key to use them. One exception is the high accurracy mode, which may be encrypted, but AFAIK, neither is. Too many civilian services use it. It's not really regional, so that you could turn it off or on for just a certain region. AFAIK, the high accurracy mode was turned to "unencrpted" back in 2000 and has never gone back.