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GeekJedi
RF is Good For You
Premium
join:2001-06-21
Mukwonago, WI

2 recommendations

reply to Brisk6

Re: It's not about the network's potential to interfere with GPS

said by Brisk6:

It's about the network's potential to interfere with poorly-designed GPS receivers that work outside of specification.
LightSquared did nothing wrong in it's business plans, I believe it falls on the backs of the receiver manufacturers to fix this. They made sloppy equipment.
If the FCC had interference concerns, then it shouldn't have licensed the spectrum to begin with.

Speaking of which, isn't this covered under the old FCC adage "Device must accept any interference, including interference that may cause undesired operation" ?

Here we go again...

No it's not covered under Part 15 or anything else.

LS's license is for Satellite-to-ground communication. The FCC granted a waiver *if* LS could prove that they wouldn't interfere with GPS devices. Well, they couldn't.

Modern low-end GPS devices do not have the sharp filtering necessary to filter out LS's ground-to-ground signal which is an order of magnitude more powerful than the space-to-ground signal that everyone originally expected to be there.

Had LS done space-to-ground, then there'd be no interference problem with GPS devices because they were designed with that in mind. The burden is on LS to essentially build a ground network using the same power level as that which would be received from space. That, unfortunately would be difficult and expensive but would not interfere with GPS.

The problem here was that LS thought they had found "free money" by converting this satellite-to-ground license into essentially a nation-wide ground-based license. Now they're angry because they're finding out that the licenses are really worth what they paid for them, which wasn't a lot, compared to what similar licenses would go for at auction.

So the bottom line again is this: Either change your biz plan to utilize satellite-to-ground comms like your license states, or try and get your money back and turn in the license.
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The goal of the broadcast engineer is to get all the meters on the transmitter to go as far to the right as possible!!