As a condition for approval of the carrier's plan for a combined satellite and LTE (Long-Term Evolution) network, the U.S. Federal Communications Commission with partners from the Global Positioning System industry to test interference and propose ways to mitigate it.

Late Wednesday afternoon, there was still information coming in for use in the report, according to LightSquared spokesman Chris Stern.

"It's a lot to digest, and we want to do this right," Stern said, explaining the request to the FCC for an extension until July 1.

Following the FCC's requirements, LightSquared formed a Technical Working Group to devise and carry out test plans for GPS interference. The group has been and was due to release its final report on Wednesday.

LightSquared's plan is to combine satellite and LTE into a mobile data network that is available in remote regions of the U.S. and offers higher speeds in metropolitan areas. But some of the frequencies it plans to use for LTE are next to spectrum already allocated for signals between GPS satellites and the devices that use them, including mobile phones and vehicle navigation systems.