LightSquared, the company wanting to offer wholesale 4G service across the US, has hit another road block.
After being asked by the DoD and DoT, the FCC performed testing to show that the network does interfere with GPS signals.
75% of GPS receivers experienced "harmful interference" when within 100 meters of a transmission tower.
LightSquared, outraged by the leak of data, has always stated in it's defence that GPS makers rely on frequencies assigned to other licensees.
Spectrum owned by LightSquared and spectrum used by GPS devices are very close together in range.
Even with a planned 40,000 towers across the US, this 'harmful interference' the government is talking about is merely affecting a fraction of surface area of the country. Never mind the accusation that GPS devices are using frequencies not assigned to them.
So at an average speed of 80 km/h driving by a transmission tower, you would loose the GPS signal for maybe 10 seconds or so. I don't think this is much of concern at all myself, considering the benefits of a nationwide 4G cell service.