LightSquared's planned 4G wireless network caused "harmful interference" to the majority of GPS receivers used in recent government testing of the network, according to reports citing a draft version of the test results.
LightSquared plans to offer network services like wholesale Internet access to companies such as Best Buy, but concerns about the network knocking out personal or military GPS devices have been raised by the Defense Department, the Federal Aviation Administration, and GPS companies and users. The LightSquared network uses frequencies that are near to those used by GPS devices.
In response to earlier tests, the company said it would use only the frequencies furthest away, but these new results suggest that won't necessarily solve the problem.
The Wall Street Journal reported that a congressional aide who saw preliminary test results analyzed by government-industry advisory board the National Space-Based Positioning, Navigation and Timing Systems Engineering Forum said "a great majority" of the commercial and military GPS units tested suffered from interference.
And news service Bloomberg, which said it saw the draft, from testing conducted October 31 to November 4, reported that it showed that "millions of fielded GPS units are not compatible" with the planned network.
The Federal Communications Commission gave LightSquared permission earlier in the year to build the network but said the company couldn't throw the switch on the system until the interference problems were addressed. The government still has one round of testing to finish on the network, set for early next year. After that, the FCC is expected to decide if the system is good to go.
The National Space-Based Positioning, Navigation and Timing Systems Engineering Forum plans to offer its final report on this recent testing to the Commerce Department before the end of the year.
LightSquared has argued that the GPS industry should have vacated the spectrum in question years ago and that the industry should foot the bill for the fixes required to prevent the interference--a bill that could end up totaling as much as $400 million. The GPS companies, meanwhile, have balked, saying their gear is too crucial to risk interference.
The Journal reported that LightSquared has called for a government investigation of the leaked draft and has said that the preliminary results are inaccurate because in practice the network would operate at a lower power level, thus lessening its effect on GPS receivers.
"By ignoring this commitment by LightSquared, this conclusion is erroneously based on estimated power levels that are up to 15 times the levels guaranteed by LightSquared," the Journal quoted Martin Harriman, LightSquared's executive vice president of ecosystem development and satellite business, as saying.