DOT: Not So Fast, LightSquared

FAA testing shows GPS interference.



Despite bold predictions by LightSquared that the firm's proposed mobile satellite service would soon win FCC approval, Department of Transportation officials on Wednesday said the company's 4G broadband technology does indeed interfere with "the majority" of global positioning system receivers and poses dangerous disruption to aviation safety systems.

The findings, announced after recent testing by the FAA and Department of Defense, throw into serious doubt claims by LightSquared that its ground tower network would interfere only with a limited number of GPS receivers, and not high-performance aviation equipment. The DOT also said the LightSquared network interferes with TAWS, which obtains its position data from GPS. Over the next several weeks, the analysis of the findings will be completed and a final report will be sent to the FCC, said Transportation Department officials.

Fighting to salvage its satellite business, LightSquared agreed to use a different portion of satellite spectrum further away from GPS. However, its signals would cause “harmful interference to the majority of other tested general purpose GPS receivers,” and separate tests showed “interference with a flight safety system designed to warn pilots of approaching terrain,” according to a statement issued Wednesday by the National Coordination Office for Space-Based Positioning, Navigation and Timing.

LightSquared, however, holds starkly different views from those of the DOT. “We profoundly disagree with the conclusions drawn with respect to general navigation devices,” said LightSquared CEO Sanjiv Ahuja in a statement. He blamed GPS interference on the GPS devices themselves and not on the company’s proposed network. “We have taken extraordinary measures — and at extraordinary expense — to solve a problem that is not of our making.”