Action follows opposition of federal GPS users.

Yesterday we reported that federal spectrum users had decided there was no way to mitigate interference from LightSquared into GPS, a finding that led the FCC to announce it would withdraw LightSquared’s conditional waiver to offer terrestrial service on mobile satellite frequencies.

The FCC has since issued a public notice seeking comment on its intended withdrawal of the waiver. We detect a note of irritation. The public notice relates how the FCC and LightSquared had moved forward through several stages of approval that culminated in the conditional waiver. Yet the GPS users were silent for most of that process, only to come forward with their objections at a relatively late stage.

The FCC has also made available the letter from National Telecommunications and Information Administration (NTIA) which, on behalf of federal spectrum users, prompted the FCC to propose terminating LightSquared’s authority. Along with that letter is one from the National Space-Based Positioning, Navigation and Timing Executive Committee (EXCOM), a test report commissioned by NTIA and EXCOM, a cover letter from EXCOM accompanying a test report from the National Space-Based Positioning, Navigation, and Timing Systems Engineering Forum, and a cover letter from the Federal Aviation Administration introducing an FAA test report. Some of these documents are redacted for public consumption. It is possible that other reports, not made publicly available, also influenced NTIA’s decision to come out against LightSquared’s plans.

Comments on the proposed withdrawal of the LightSquared waiver are due on March 1, 2012. There is no provision for reply comments.