With a testing carried out by a federal agency having reportedly revealed that LightSquared's proposed countrywide, open-access 4G wireless broadband service "caused harmful interference to majority of GPS receivers tested," it is evident that yet another hurdle has come the way of the proposed broadband service.

The tests - which were called for by the National Telecommunications & Information Administration; and conducted on behalf of the Department of Defense, the Federal Aviation Administration, and a few GPS makers - showed that the broadband service proposed by LightSquared interfered with the performance of 75 percent of the 92 GPS receivers which were tested.

According to a report from Bloomberg news service, the leaked draft results of government tests arrive at the final conclusion that, as per a comprehensive analysis, "millions of GPS units are not compatible" with the $14 billion nationwide broadband network which LightSquared had proposed to build.

LightSquared has planned that it would build the mentioned network and then sell it to wholesale providers. While the company intended devoting a substantial part of the its spectrum - ranging from 1525MHz to 1660.5MHz - to the proposed network, it is being reported that the LightSquared spectrum is awkwardly close to what is being used by most of the GPS devices.

Noting that LightSquared was "outraged" by the release of the government data, the company executive VP Martin Harriman said that the testing "attempts to draw an inaccurate conclusion to negatively influence the future of LightSquared and narrowly serve the business interests of the GPS industry."