Nascent broadband provider LightSquared's plans to roll out a satellite-terrestrial network adjacent to the GPS band next year have been halted by the US Federal Communications Commission (FCC).
"Following extensive comments received as a result of the technical working group process required by the [26 January conditional approval for the network], the FCC, in consultation with National Telecommunications and Information Administration (NTIA), has determined that additional targeted testing is needed to ensure that any potential commercial terrestrial services offered by LightSquared will not cause harmful interference to GPS operations," the FCC writes in a 13 September public notice.
The order follows months of government and industry testing of the baseline LightSquared network, which called for rebroadcasting L-band satellite signals at high power via 40,000 transmission towers on the ground. The FCC gave LightSquared a conditional approval for the system in January, pending a satisfactory outcome of interference trials.
After initial testing showed that interference from prototype ground-based transmitters would cripple aviation and variety of other GPS receivers, LightSquared in June revised its plan to operate in a portion of its assigned band farther from GPS, with reduced power and other changes designed to minimize the impacts.
Industry and government agencies, including the US military, NASA and others, remained concerned that the modified plan could pose harmful interference, and had asked the FCC for more testing.