This fight has been going on for years. I’m too lazy to go back and research
the whole issue, but there’s a band of frequencies adjacent to the some of the current GPS
frequencies that they want to reallocate for terrestrial use. The original company that invested big bucks into purchasing
the frequencies was, IIRC, called Lightsquare. The FCC has been on both sides at various times. The Defense Department always opposed it, basing some of their arguments on possible adjacent channel interference
to terrestrial GPS
users, particularly those with "cheaper” GPS units that might not be able to reject the adjacent channel signals.
Lots of money
in play and lots of "experts" on both sides of the fence.