Latest Tests Show LightSquared Disrupts Most GPS
Federal officials Wednesday confirmed earlier reports that signals from a nationwide broadband system proposed by LightSquared will significantly disrupt existing GPS service. In separate statements, the National Coordination Office for Spaced-Based Positioning, Navigation and Timing (PNT), the Department of Defense and the Department of Transportation essentially said that under current circumstances, GPS cannot coexist with LightSquared's planned 40,000-tower network of high-speed wireless broadband transmitters. "LightSquared signals caused harmful interference to the majority of … general purpose GPS receivers," said Anthony Russo, director of PNT. The comments were based on recent test results that also showed the signals could affect TAWS. Cellphones are not affected significantly, according to the tests. LightSquared said it rejects the findings about the GPS receivers but is willing to work with the FAA on TAWS. The GPS interference, LightSquared claims, is the GPS industry's fault, which, regardless of the veracity of the claim, may be a moot point.
In a statement, LightSquared CEO Sanjiv Ahuja said the problem isn't that his company's signals invade GPS's territory, it's that GPS receivers "look into" LightSquared's spectrum. "LightSquared has had the legal and regulatory right to use its spectrum for eight years over two administrations," Ahuja said. "The testing further confirmed that the interference issues are not caused by LightSquared's spectrum, but by GPS devices looking into spectrum that is licensed to LightSquared. We have taken extraordinary measures -- and at extraordinary expense -- to solve a problem that is not of our making. We continue to believe that LightSquared and GPS can co-exist." However, the FCC waiver that would permit LightSquared to operate its system appears to place the onus on LightSquared to ensure its signals do not interrupt GPS service. LightSquared is expected to have more to say about the tests on Thursday.