LightSquared wants to offer cellular broadband over spectrum that's next to the band used by GPS (Global Positioning System), but tests have shown that its network would interfere with GPS receivers. On Feb. 15, the U.S. Federal Communications Commission proposed cancelling a conditional waiver it had given to LightSquared and indefinitely suspending its permission to build a land-based network.

The agency then set aside time for public comments on its plans, followed by responses to those comments. Thousands of comments came in, arguing on both sides of the issue, and the FCC extended the opportunity to comment. The response period finally ended last week.

In its formal response, filed on Friday, LightSquared slammed its opponents' comments as "revisionist history" and said the FCC's proposal was unsupported by law, science or precedent. LightSquared said the agency could either test more possible solutions to the interference, acknowledge LightSquared's spectrum rights and make GPS vendors pay for solving the problem, or give LightSquared a different block of spectrum. The carrier's loudest critic, the industry group Coalition to Save Our GPS, said LightSquared shouldn't get to use the spectrum because it didn't fulfill a requirement to resolve interference issues.

After reviewing the comments and responses, the FCC could go ahead with its plans or take some other course of action. It has no deadline to act. If it decides to kill LightSquared's plan, the carrier will be given time to file a protest.

It appears unlikely the FCC will act soon.