Things are looking bleak for the proposed LightSquared LTE network according to a story in PC World.

A key federal agency involved in testing the proposed LightSquared LTE network has concluded that there is no practical way to solve interference between that network and GPS, possibly dealing a crippling blow to the startup carrier’s hopes for a terrestrial mobile network.

That agency is the National Space-Based Positioning, Navigation and Timing Executive Committee (PNT ExComm). Now that’s a mouthful. The agencies that make up this one have unanimously concluded that none of the LightSquared proposals would overcome interference with GPS.

Here’s an excerpt from the letter to the FCC:

Earlier this week we published results of our ZimmPoll that showed a majority think the LightSquared proposal would be good for ag/rural America. However, most of those positive responses all came at nearly the same time.