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View Full Version : FCC Darkens Lightsquared over GPS QRM



W3WN
02-15-2012, 12:08 PM
Multiple news reports today indicated that the FCC is banning the LightSquared wireless broadband system due to interference concerns with GPS. This as a follow up to earlier rulings by the NTIA that this interference was not acceptable to government users (including the military) and that there was no way for LightSquared to mitigate this with the system they propose.

What I really like is how the LightSquared people blame the interference on technological issues with GPS. Right. Even though the waiver included a condition that LightSquared can NOT cause any "harmful inteference" with GPS & other users of the "nearby" spectrum, and that LightSquared has acknowledged that there can be "potential interference issues."

And, of course, LightSquared is threatening to sue the FCC. Beautiful.

Multiple links including:

http://money.cnn.com/2012/02/15/technology/lightsquared_gps/index.htm
http://news.cnet.com/8301-1035_3-57378009-94/fcc-suspends-lightsquared-waiver-over-gps-interference/
http://www.politico.com/news/stories/0212/72909.html
http://www.engadget.com/2012/02/14/fcc-to-deny-lightsquared-lte-bid/
http://online.wsj.com/article/SB10001424052970204795304577223764266276288.html
http://www.ibtimes.com/articles/299118/20120215/lightsquared-fcc-wireless-network-sprint.htm
http://www.forbes.com/sites/danielfisher/2012/02/14/fcc-grudgingly-hangs-up-on-lightsquared-over-gps-concerns/
http://patdollard.com/2012/02/lightsquared-fcc-to-nix-obama-owned-wireless-network-that-jams-militarys-gps/
http://www.bloomberg.com/news/2012-02-14/lightsquared-conflict-with-gps-devices-can-t-be-fixed-u-s-regulator-says.html
http://gigaom.com/broadband/fcc-puts-the-kibosh-on-lightsquareds-lte-plans/
http://www.dslreports.com/shownews/LightSquared-is-Dead-118383

Also background info on the waiver itself:
http://www.pnt.gov/interference/lightsquared/

And, a YouTube video about how LightSquared is being picked on by the FCC, and how it's Affecting the Future of America (Riiiight): http://www.youtube.com/watch?v=oKWJbXr1cOY

KC2UGV
02-15-2012, 01:10 PM
Sigh. While I can understand the required mitigation of Military Applications; the basic premise of the issue remains: GPS receivers were designed to never have to worry about nearby transmitters.

The government report states that the required fix is to replace the GPS receivers with better ones, designed to work as they should (Only recieving what they are supposed to). Currently, GPS receivers are akin to crystal radio sets: Wide as a barn door.

It's like PSK ops complaining about their front-ends being overloaded, while they refuse to use filters.

W3WN
02-15-2012, 02:10 PM
Sigh. While I can understand the required mitigation of Military Applications; the basic premise of the issue remains: GPS receivers were designed to never have to worry about nearby transmitters.

The government report states that the required fix is to replace the GPS receivers with better ones, designed to work as they should (Only recieving what they are supposed to). Currently, GPS receivers are akin to crystal radio sets: Wide as a barn door.

It's like PSK ops complaining about their front-ends being overloaded, while they refuse to use filters.OK, so if that's right (and it probably is, I just don't know)... what are you going to do about the hundreds of thousands, if not millions, of consumer-market GPS receivers & devices already out in the field?

I have no problem with the FCC mandating that newer GPS units (built after, say, another 6 months or a year from now, to allow enough time for design and manufacturing changes) have better receivers. But as a practical matter, you can't do much about the existing units.

To use your analogy, it's one thing for PSK ops to complain while refusing to use filters. It's another if it's not technically possible for them to do so (yeah, I know the analogy breaks down on that point, since WE do, or ought to, know how to run filters. But to the general public? A GPS receiver is a GPS receiver... what's a filter?)

KC2UGV
02-15-2012, 03:02 PM
OK, so if that's right (and it probably is, I just don't know)... what are you going to do about the hundreds of thousands, if not millions, of consumer-market GPS receivers & devices already out in the field?


And, that is the rub: Private pilots, Airlines, and other industries are the ones fighting it, because they want to NOT replace a thing until it breaks. Might cost them a couple of extra bucks.

And, of course, industry will now have to pay for R&D after 25 years of charging exorbitant premiums on devices they've not made a single change to in 15 years. Case in point: A bare GPS chip costs about $20.

I'll get to consumers below...



I have no problem with the FCC mandating that newer GPS units (built after, say, another 6 months or a year from now, to allow enough time for design and manufacturing changes) have better receivers. But as a practical matter, you can't do much about the existing units.


And, I think that is a valid issue. There should be some rule making that states GPS units after Date X (Like 2 or three years) will no longer be protected. And, as of today, you must make GPS devices that can accept the interference and deal with it.

If you put it at 3 years, most consumers have replaced their devices anyways (Most do not use a dedicated GPS device, but rather, and embedded one). And, the remainder of the old school devices will just have to deal with the GPS not working if they're within a half mile of a LightSquared transmitter.

Yep, that's it. The trouble range is 1/2 mile.



To use your analogy, it's one thing for PSK ops to complain while refusing to use filters. It's another if it's not technically possible for them to do so (yeah, I know the analogy breaks down on that point, since WE do, or ought to, know how to run filters. But to the general public? A GPS receiver is a GPS receiver... what's a filter?)

And, it's the reason I can understand giving a couple of years lead time. But, how long has this application been approved? How long have the GPS makers known this was coming?

They're dragging their feet because they don't want to have to pay any money to redesign a thing.

W3WN
02-16-2012, 10:26 AM
One thing to consider, too: Just because LightSquared is claiming that GPS receivers are picking up (out-of-GPS-band) signals they shouldn't doesn't make it so. I see in the various articles and blog & pundit posts a presumptiion that this is the case... but is it?

That aside, the bottom line though is this: LightSquared got their conditional waiver 2 years ago on the condition that, or with the understanding that, they would not interfere with GPS systems. Which they agreed to. So they really can't very well argue that it's not their fault; no one is saying that it is. That's the big MacGuffin in the room.

And according to at least one news article, LightSquared has additonal bandwith available to them, in the 1.4, 1.6, & 2 GHz bands. None of which are affected by the GPS issue. So one wonders why they pinned their corporate hopes & dreams to a band segment (1525 - 1559 MHz) that has the interference potentials?

Further... in September 2011, LightSquared claimed that "99.5 %" of all commercial GPS devices would be "compatible" (from context, one would imply this means would not suffer QRM from) with the proposed LightSpeed network. So now who's blowing smoke... LightSpeed, or NTIA, or the GPS industry? Was this announcement wishful thinking? An attempt to use PR to overcome a technical issue? Is the NTIA being proactive, or are they over-reacting?

WTKX
02-16-2012, 10:35 AM
Obvious lack of technical considerations on both sides. However, GPS systems are already in place, and avoiding that spectrum segment would have been the correct move.

What a waste of time, money, and talent.

KC2UGV
02-16-2012, 10:45 AM
One thing to consider, too: Just because LightSquared is claiming that GPS receivers are picking up (out-of-GPS-band) signals they shouldn't doesn't make it so. I see in the various articles and blog & pundit posts a presumptiion that this is the case... but is it?


LightSquared isn't claiming that. The USAF's report on the situation claims it.



That aside, the bottom line though is this: LightSquared got their conditional waiver 2 years ago on the condition that, or with the understanding that, they would not interfere with GPS systems. Which they agreed to. So they really can't very well argue that it's not their fault; no one is saying that it is. That's the big MacGuffin in the room.


Let me ask this question:

If I am operating CW on 160 meters, using an AM filter; and I hear broadcast band AM inside of my filter, is the AM broadcast band station interfering with me? Or, are my filters just too wide, and I am hearing part of the AM broadcast band?



And according to at least one news article, LightSquared has additonal bandwith available to them, in the 1.4, 1.6, & 2 GHz bands. None of which are affected by the GPS issue. So one wonders why they pinned their corporate hopes & dreams to a band segment (1525 - 1559 MHz) that has the interference potentials?


1525-1599 has much better building penetration ability than the higher bands.



Further... in September 2011, LightSquared claimed that "99.5 %" of all commercial GPS devices would be "compatible" (from context, one would imply this means would not suffer QRM from) with the proposed LightSpeed network. So now who's blowing smoke... LightSpeed, or NTIA, or the GPS industry? Was this announcement wishful thinking? An attempt to use PR to overcome a technical issue? Is the NTIA being proactive, or are they over-reacting?

And, that's true. The only receivers that would have issue with is are those within a 1/2 mile bubble around a LightSquared transmitter.

It's the GPS industry blowing smoke, as well as the airline industry. GPS industry doesn't want to spend money on new R&D; and the airline industry doesn't want to have to replace their GPS modules.

n2ize
02-18-2012, 05:01 PM
1525-1599 has much better building penetration ability than the higher bands.
.

Freq's in the 1.4 and 1.6 range should work just as well. There is adequate energy at those frequencies to allow for similar penetration and structural propagation as in the 1.5 range. 1.5 plus or minus 0.2 should work quite well.

K7SGJ
02-24-2012, 11:36 AM
Freq's in the 1.4 and 1.6 range should work just as well. There is adequate energy at those frequencies to allow for similar penetration and structural propagation as in the 1.5 range. B.5 plus or minus 0.2 should work quite well.

I've always found penetration to be important.

N2PYS
02-24-2012, 04:07 PM
You know our infertility specialist said the same thing to my wife and i when we where trying to have a baby and just couldn't after 2 years of trying.

N8YX
02-24-2012, 07:12 PM
You know our infertility specialist said the same thing to my wife and i when we where trying to have a baby and just couldn't after 2 years of trying.

:lol:

Welcome to the Island!

Charles, what kind of drink does a comment such as the quoted one call for?

K7SGJ
02-24-2012, 09:19 PM
Hemlock

Welcome to the Island. The barkeep will be along shortly. Feel free to drink till ya puke, and put it on Carls tab.

Have him pay for the drinks, too.