LightSquared’s LTE broadband wireless network interferes with the GPS signals that are crucial for systems like aircraft navigation, according to fresh government tests.

Last month, the National Executive Committee for National Space-Based Positioning, Navigation & Timing, and the Federal Aviation Administration tested the LightSquared systems and found them disrupting the signal strength to all GPS devices in the test area.

In some tests, all GPS-based receivers including those used by the U. S. Coast Guard lost their ability to navigate. Some GPS systems used by space agency NASA for scientific use were also seriously impacted due to LightSquared’s service.

LightSquared, a Virginia-based wireless startup, wants to get into a popular land-based cellular business through a 4G LTE network, which is much powerful than its existing satellite communications network.

Earlier in January, the FCC approved LightSquared’s request to broadcast its new service, but the service was strongly opposed by GPS manufacturers such as Trimble Navigation.

The results of tests will be handed over to the Federal Communications Committee by June 15. The report will also include a recommendation as to weather or not LightSquared should be deployed commercially.