Monday, February 20, 2012

Why LightSquared Failed

Inevitably, despite the small possibility of some positive resolution, we now will see a period of reflection where observers try to explain "why LightSquared failed." That doesn't mean LightSquared has given up. But as some of us have been saying for a while, the big problem here is interference.

When the frequencies were originally awarded for mobile satellite use, what became the LightSquared spectrum was a "low-power" application, in terms of the transmitted downlink signals.

Mobile communications service is, by way of contrast, a "high-power application." And since all radio communications (digital or analog) is fundamentally a matter of signal-to-noise ratio, there are some physical locations (close to proposed cell sites) where the signal strength of the cell towers simply overpowers the received GPS signal

This is physics, not politics. As originally designed, the satellite-based GPS network and the satellite-based mobile communications network could have co-existed, without interference, because both were low-power systems.

LightSquared has tried to paint the objections as a matter of politics and vested business interests. Those interests do exist. So one explanation for LightSquared's almost-certain failure (assuming one believes there still is a real possibility of fixing the interference issue)  already can be sketched out.

 "Entrenched and vested interests," including the GPS industry and some mobile telecom providers,  were able to defeat LightSquared by political and financial assets brought to bear on the spectrum re-authorization process.

Others would note that the aviation industry and U.S. military also objected, though. No FCC commissioner is going to risk "an airliner falling out of the sky," or other risks to passenger safety. 

LightSquared needed an FCC waiver because it was trying to use spectrum allocated for low-power space-to-ground transmissions for high-power ground-only transmissions. Interference issues with adjacent low-power satellite apps are well understood, which is why two adjacent satellite bands originally were authorized.  Why LightSquared failed


No comments:

"Tokens" are the New "FLOPS," "MIPS" or "Gbps"

Modern computing has some virtually-universal reference metrics. For Gemini 1.5 and other large language models, tokens are a basic measure...