Reports on recent tests have shown the company's LTE (Long-Term Evolution) equipment knocked out Global Positioning System gear used for aviation, surveying, consumer navigation and other applications. The U.S. Defense Department and Transportation Department LightSquared's plan. LightSquared will need to persuade the Federal Communications Commission (FCC) that the interference can be prevented before the agency will allow the project to continue.

On Wednesday, the carrier is due to issue a report from . The group was formed to devise tests to determine interference.

LightSquared by agreeing to combine an LTE network with a satellite system, which the FCC sees as a tool to improve mobile data access in rural areas of the U.S. The carrier plans to sell its cellular and satellite services wholesale to service providers who can offer subscribers either or both services. It won't offer any service plans of its own. have announced plans to resell LightSquared service.

However, part of the cellular spectrum LightSquared holds is next to frequencies used by GPS, the service that allows vehicles, airplanes, cell phones and other systems to determine their location via satellite signal. Conditions of the FCC's approval of LightSquared's network require the company to show GPS service would not be hurt. Over the past few months, LightSquared and its Technical Working Group have been devising and carrying out tests leading up to Wednesday's report.

Some test results disclosed at a meeting in Washington, D.C., on June 9 indicate the LTE network might put aviation, public safety and other valued uses of GPS at risk.