LightSquared's conditional approval to operate ground-based 4G LTE transmitters (cell towers) was revoked by the FCC this week. This is great news for GPS users. GPS has an incredibly weak signal and can be easily interfered with, or jammed. 4G services by their nature are high powered relative to GPS signals, and even though the frequency bands used by both were not the same, they were next to each other - causing unacceptable interference to GPS receivers.
LightSquared secured their spectrum quickly through the FCC, and interference issues were not taken into account by either party. Because GPS is the equivalent of a national utility used by both civilians and the military, the FCC and LightSquared both screwed up by ignoring the interference possibilities. Additionally, GPS receiver manufacturers could have put filters in place (though not completely effective), to alleviate some of the interference from any outside transmissions. However, there have been no realized threats to the spectrum - why would the receiver manufacturers build something into a receiver, at their expense for a problem that didn't exist?
The good news is, your GPS receiver, my GPS receiver, the FAA's NextGen air traffic control system, banks, power companies, farmers, cellular service providers and all other users of GPS can now stop worrying about whether their GPS receivers will work when LightSquared turned on their system.
GPS receiver manufacturers should take note - you got lucky this time, but now IS the time to start building in safeguards and fortifying your defenses against jamming, unintentional, or intentional. There will be other spectrum contenders to come.