The Federal Aviation Administration says even a revised proposal from LightSquared to launch a national wireless broadband network will interfere with global positioning systems critical to aviation.
LightSquared has come under fire from the GPS industry and its users over concerns that the company's proposal to deploy a wireless broadband network using both land-based transmitters and a satellite would interfere with GPS systems. In response, LightSquared said in June that it will hold off for now on using the spectrum closest to that used by GPS receivers and operate at a reduced power level than it is authorized to use.
In an assessment conducted earlier this month but only recently released, the FAA appears to have concluded that even this revised proposal would still interfere with GPS systems used in aviation.
"The effects of LightSquared deployment would be far-reaching and potentially devastating to aviation. Proposed LightSquared operations would severely impact the efficiency and modernization of the safest, most efficient aerospace system in the world," according to the July 12 report from the FAA's Navigation Services.
The Save Our GPS coalition, which is made up of companies and groups representing GPS users and companies that offer GPS services, seized on the report as more evidence of its claims that LightSquared's proposed network would severely hamper the use of GPS.
"The FAA report is an extraordinary indictment of LightSquared's plans. Just consider the fact that FAA analysis and tests find that if LightSquared is allowed to deploy as it wants to that 'GPS is expected to be unavailable for planned aviation use over the whole of the continental U.S.,'" Jim Kirkland, vice president for GPS services provider Trimble, which is a member of the coalition, said in a statement.
LightSquared responded that it did not believe the FAA report fully examined its latest proposal.
The FCC letter "doesn't accurately reflect LightSquared's most recent proposal which is focused solely on using the spectrum furthest away from GPS. Simply put, the vast majority of the interference issues raised by this report are no longer an issue. We look forward to discussing this with the FAA," LightSquared Executive Vice President for Regulatory Affairs Jeff Carlisle, said in a statement.
An FAA spokeswoman did not respond to a request for comment on LightSquared's claim that the report didn't take into account the changes made to LightSquared's proposal.
The FAA report, however, does refer to the revised proposal from LightSquared.
"This operational, economic, and public safety impact assessment is based upon LightSquared's June 30, 2011 proposal and June 23, 2011 LightSquared testimony to the House Transportation and Infrastructure Committee, including use of the lower 10 Megahertz channel starting in 20l2 and any use of the upper 10 MHz channel starting in 2014. This assessment assumes the planned power is one-tenth the current authorized power," the report said.
The report also makes an apparent reference to the spectrum LightSquared said it would use in its revised proposal. "The FAA cannot conclude that operations using just the lower portion of the spectrum are compatible with civil aircraft receivers without definition of LightSquared's end-state deployment and further study. However, based upon existing data, LightSquared's operations at the lower channel would preclude the following critical capabilities that rely upon high-precision GPS receivers: airfield and flight procedure surveys, flight test tracking, space weather monitoring, and GPS timing for computing resources and many mission critical systems."