LightSquared is attempting to launch a new LTE network, to provide 4G service both to carriers like Sprint and to end users. However, the spectrum it has lined up for that network has the potential to interfere with GPS receivers used by both consumers and the military. The FCC has provisionally given the company permission to launch, depending on whether or not tests show that the network can operate without interference.
A draft of a test commissioned by the government has leaked, and the results don't look good for LightSquared. Apparently, the "great majority" of GPS devices tested experienced interference, meaning that "millions of fielded GPS units are not compatible" if the report is confirmed. LightSquared is clearly not happy with the leak, calling for a government investigation and saying the report is "patently false" because the test doesn't take into account the actual power levels LightSquared will use to transmit its LTE signal.
LightSquared has a long history of arguing, perhaps over-strenuously, that its network won't interfere with GPS devices. In addition to commissioning its own reports, it has also worked with another company to create prototypes to help precision GPS devices avoid interference. LightSquared is also promising that its network will lower the overall costs of LTE service. In all, it adds up to a PR offensive with the goal of convincing the FCC and consumers that the planned network gets launched. There's obviously a lot of money on the line, Harbinger Capital Partners has invested $3 billion in LightSquared, while Sprint, Best Buy, and others are making plans on using its network. The government is set to make its final decision next year, but in the meantime it's likely that we'll see LightSquared and its detractors continue to debate the GPS interference issue.