LightSquared is calling for an investigation of the source of possibly leaked data from the recently completed GPS interference tests conducted by the U.S. government that evidently contradict more favorable test results recently promoted by the company.

The tests LightSquared performed with GPS equipment makers Javad GNSS, PCTel and Partron were touted as demonstrating that concerns over the threat posed by the company’s proposed wireless service to GPS users were overstated (Aviation Daily, Dec. 9). LightSquared also was a party to the government tests. LightSquared has rights to two 10-MHz swaths on the Mobile Satellite Service band, where it was conditionally granted permission to operate a 4G wireless broadband network based on as many as 40,000 high-powered, ground-based transmitters, raising concern about overload jamming of GPS receivers.

Earlier tests this spring, which focused on the so-called upper band, 1545-1555 MHz, closest to the 1559-1610-MHz GPS band, showed significant, possibly catastrophic interference to virtually all classes of consumer, military and precision agricultural GPS receivers. Subsequently, LightSquared said it would not immediately use the upper band, and a second round of testing was conducted near Holloman AFB, N.M., focusing on LightSquared’s lower band, 1526-1536 MHz, farther away from the GPS band. It was the preliminary report of these last tests that was seen and reported by Bloomberg News on Dec. 9. The report said that 69 of 92 GPS units, or 75%, “experienced harmful interference” at the equivalent of 100 meters (109 yards) from a LightSquared base station, Bloomberg reported.

LightSquared CEO Sanjiv Ahuja says the leaked draft report was an “incomplete, selective and slanted analysis of the testing of general location/navigation devices,” in a letter to government officials and in a press call Dec. 12.

The official interference report, expected to be released imminently, probably will shed more light on the subject.