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To: lump in the melting pot
Jeff Carlisle, executive vice president for regulatory affairs [wrote]: "it appeared that the GPS industry had become “too big to fail,” noting that “GPS manufacturers have been selling devices that listen into frequencies outside of their assigned spectrum band – namely LightSquared’s licensed band.”

Buddy, you need to talk to an actual RF engineer, rather than your hedge fund and political buddies.

The spectrum on either side of the GPS frequencies were purposely put there. They are what is known as a "guard band".

GPS transmissions are very low power, at least by the time the device receives them. It takes a significant amount of digital signal processing to extract the signal from the background noise.

If you transmit a signal at a much higher power in an adjacent frequency, it "blanks" the receiver. That's why those guard bands were reserved for OTHER low-power satellite transmissions. GPS devices don't listen outside their assigned frequencies, but they are affected by high power transmissions NEXT to the frequencies they listen to.

Filtering is possible, but difficult -- especially at the differential power levels we are talking about. However, even if it is possible, GPS devices have been designed and built for the past two decades with the expectations that those guard bands were in place.

Then, you came along and paid off a bunch of politicians to change the rules. They saw $$$, but they are a bunch of idiots that know nothing about the technical issues.

They sold you a pig in a poke. You got burned. It's your fault for not doing your due diligence.

5 posted on 02/15/2012 6:15:49 AM PST by justlurking (The only remedy for a bad guy with a gun is a good WOMAN (Sgt. Kimberly Munley) with a gun)
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To: lump in the melting pot
If you transmit a signal at a much higher power in an adjacent frequency, it "blanks" the receiver.

I forgot to explain why the signal is much higher power.

These guard bands were originally reserved for satellite-to-ground transmission. However, the politicians sold/assigned them to LightSquared, knowing full well that LightSquared intended to use them for terrestrial transmitters.

Yes, that's right: they wanted to put up a network of towers similar to a cell phone network, transmitting at a (relatively) high power, right next to the GPS band.

8 posted on 02/15/2012 6:22:11 AM PST by justlurking (The only remedy for a bad guy with a gun is a good WOMAN (Sgt. Kimberly Munley) with a gun)
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To: too_cool_for_skool

Read this.


33 posted on 02/16/2012 5:30:06 AM PST by dynoman (Objectivity is the essence of intelligence. - Marylin vos Savant)
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