According to a story by David Murphy in PC Magazine:
When it rains for LightSquared, it pours for LightSquared. The ambitious, proposed wholesaler of LTE service -- designed to ultimately give consumers additional options for tapping into high-speed mobile Internet -- has come under a great deal of fire for the alleged interference that its network creates for common GPS devices. And the results of a new government test certainly don't help LightSquared make its case.
According to the news service Bloomberg, leaked draft results of government tests indicate that the base stations for LightSquared's proposed 4G LTE network created "harmful interference" for 75 percent of the 92 GPS devices used within the test -- up to 109 yards away from the base station, we note. And the overall conclusion? The analysis reports that that "millions of GPS units are not compatible"
Full story is at.