Philip Falcone’s proposed LightSquared Inc. wireless service caused interference to 75 percent of global-positioning system receivers examined in a U.S. government test, according to a draft summary of results. The results from testing conducted Oct. 31 to Nov. 4 show that “millions of fielded GPS units are not compatible” with the planned nationwide wholesale service, according to the draft seen by Bloomberg News.“LightSquared signals caused harmful interference to majority of GPS receivers tested,” according to the draft prepared for a meeting next week of U.S. officials reviewing the LightSquared proposal. “No additional testing is required to confirm harmful interference exists.”LightSquared, backed by $3 billion from Falcone’s Harbinger Capital Partners hedge fund, faces challenges from makers of global-positioning system devices who say the service will disrupt navigation by cars, boats, tractors and planes. U.S. regulators are withholding approval as they check on claims of interference.

The Reston, Virginia-based company has proposed offering high-speed mobile Internet service to as many as 260 million people using 40,000 base stations. The service would operate on airwaves formerly reserved mainly for satellites, and near those used by GPS devices. LightSquared is proposing to operate at a lower power than the level used during the tests, and believes that its operations would affect about 10% of devices, Martin Harriman, executive vice president, said in an interview.

‘Harmful Interference’

The tests worked off an “extraordinarily conservative” threshold and didn’t show the devices’ performance was affected, Harriman said.

“If we’re affecting the performance of the device — my goodness, we’d like to be sure that doesn’t happen,” Harriman said.

The laboratory testing was performed for the National Space-Based Positioning, Navigation, and Timing (PNT) Systems Engineering Forum, an executive branch body that helps advise policy makers on issues around GPS. It found that 69 of 92, or 75 percent, of receivers tested “experienced harmful interference” at the equivalent of 100 meters (109 yards) from a LightSquared base station. The devices tested include those used for automobile and boat navigation. The forum is to present its results on Dec. 14 in Washington.

High-Precision Receivers

The testing was requested by the National Telecommunications & Information Administration, a Commerce Department agency that oversees airwaves use. The agency is still reviewing data, Moira Vahey, a spokeswoman, said in an interview today. The government is to test high-precision receivers, used in farm equipment and scientific instruments, next year. Agencies participating in the testing included the Department of Defense and the Federal Aviation Administration, according to the draft summary. Companies participating included GPS makers Trimble Navigation Ltd. and Garmin Ltd., farm-gear maker Deere & Co., and General Motor Co.’s OnStar unit, according to the summary.