The battle over whether a nationwide broadband network planned by startup wireless company LightSquared could knock out Global Positioning System receivers took a new twist Wednesday when GPS manufacturers and end users leaked to the media an internal Federal Aviation Administration report that could lend weight to their concerns.
The July 12 report said the LightSquared network would disable GPS for aviation use over the entire continental United States. "After the LightSquared network is deployed, GPS is expected to be unavailable for planned aviation use over the whole of the continental U.S. based upon FAA analysis and tests," the seven-page executive summary stated.
FAA spokeswoman Laura Brown confirmed the authenticity of the document, prepared by the agency's navigation services division and leaked by the Coalition to Save Our GPS, but she declined to answer any questions about it, as "we did not release it."
The aviation agency has invested $3 billion in GPS and its GPS-based Next-Generation Air Transportation System. The report said the LightSquared network could cost the aviation industry $70 billion over the next decade due to loss of efficiencies expected from the air traffic control modernization project as well as benefits from the current use of GPS.
After a series of GPS interference tests this spring showed that the 1545.2-1555.2 MHz upper frequency band would adversely affect the performance of a significant number of GPS receivers that operate in the adjacent 1559-1610 MHz band, LightSquared filed a new plan with FCC to use only the lower 1526-1536 MHz band farthest from GPS in the initial deployment of its network.
The July 12 FAA report, prepared for the director of the interagency Space-Based Positioning, Navigation and Timing Executive Committee National Coordination Office, said operating in the lower band would affect the aviation use of high-precision GPS receivers, forcing FAA to rely on ground-based navigation aids such as radar to manage the National Airspace System. The report added that LightSquared intended to use the lower band in 2012 and the upper band in 2014.
Jeffrey Carlisle, LightSquared's executive vice president for regulatory affairs, said in a statement emailed to the media in the wake of the leaked FAA report that it "discusses a LightSquared plan that is no longer on the table. It does not distinguish between operation in the spectrum farthest from GPS and the spectrum closest to it."
"Simply put, the vast majority of the interference issues raised by this report are no longer an issue," Carlisle said. "We look forward to discussing this with the FAA."
But, in its June 30 FCC filing, LightSquared said it intends to ultimately use all frequencies the FCC authorized.
James Kirkland, vice president and general counsel of Trimble Navigation Ltd. and a spokesman for the GPS coalition, said in statement that FAA's report is, "an extraordinary indictment of LightSquared's plans . . . The list of harms LightSquared's plans would cause just goes on and on. How much more evidence is needed to stop wasting time on this irresponsible plan?"
Carlisle called Kirkland's statement "histrionic" and said it ignored the fact that GPS manufacturers did not design their receivers well enough to avoid interference.