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LightSquared deals with continued GPS interference  (Source: engadget.com)
U.S. officials say no additional testing is needed to prove the existence of harmful interference

A recent government study found that the LightSquared Inc. wireless service interrupted 75 percent of global-positioning system (GPS) receivers.

LightSquared Inc. is a company looking to offer a wholesale 4G LTE wireless broadband communications network with satellite coverage in the United States. It was founded by Philip Falcone and has had interference issues for years now. Just this year alone, interference concerns were raised by the National Telecommunications and Information Administration (NTIA), USAF Space Command, and the U.S. GPS Industry Council.

Now, a test conducted by the U.S. government has shown that 69 of 92 (75 percent) of receivers experienced "harmful interference" at the equivalent of 100 meters from a LightSquared base station. It was deemed that millions of GPS units were incompatible with the LightSquared service, and it could affect cars, planes, boats and tractors.

The test was performed from October 31 to November 4 for the National Space-Based Positioning, Navigation and Timing (PNT) Systems Engineering Forum, which advises policy makers about GPS issues. The Department of Defense and the Federal Aviation Administration took part in the testing, as well as companies like Garmin Ltd., Trimble Navigation Ltd., Deere & Co., and General Motor Co.'s OnStar unit.

"LightSquared signals caused harmful interference to majority of GPS receivers tested," said U.S. officials in a draft prepared for the review of the LightSquared proposal. "No additional testing is required to confirm harmful interference exists."

LightSquared has proposed that it operate at a reduced power than the levels used during the testing. With low power usage, LightSquared believes its services would only affect 10 percent of devices.

Sources: Business Week, SlashGear



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10% ???
By name99 on 12/12/2011 1:30:37 PM , Rating: 3
quote:
LightSquared has proposed that it operate at a reduced power than the levels used during the testing. With low power usage, LightSquared believes its services would only affect 10 percent of devices.


WTF? "only" 10% --- and that their optimistic scenario? Just how well do they think this is going to fly, that 10% of users are going to have their GPS stop working? How long did they expect it would be until we heard some story of a rescue operation or police operation that was delayed because their GPS didn't work, or military training exercise that went wrong?

The whole plan seems to have been conceived by idiots if they thought "only" 10% was acceptable.




RE: 10% ???
By Mitch101 on 12/12/2011 1:54:28 PM , Rating: 2
At first I saw Government Survey and got worried who but then Im glad to see the DOD, FAA, Garmin, FedEx, UPS, and OnStar were involved with that survey because LightSquared is spinning a kind of different story.

http://www.rethink-wireless.com/2011/12/08/lightsq...
quote:
LightSquared has come out with its most concrete claims so far that its LTE network will not interfere with GPS services across the US. The start-up says an Alcatel-Lucent laboratory has carried out extensive tests on devices from three GPS vendors, whose preliminary results demonstrate that those devices are not disrupted by the LTE signals in nearby mobile satellite spectrum.

But then they are pretty much admitting guilt in this part of their statement:
quote:
LightSquared has proposed various remedies to the GPS issue, including restricting its services to the area of its spectrum which is furthest from the navigation service bands.

Ummm nothing more to say after that.


RE: 10% ???
By Motoman on 12/12/2011 2:00:08 PM , Rating: 2
...those two statements would, in fact, seem to contradict one another...


RE: 10% ???
By DT_Reader on 12/12/2011 2:50:44 PM , Rating: 2
What you're missing is that if the GPS folks had played by the rules and used proper filtering in the first place, this wouldn't be an issue. But when GPS began there was no LightSquared, so they cheaped out on the filters since there was nothing there to filter. Now a legitimate user of the neighboring spectrum wants to open shop and they are screaming "No!" solely on the basis of squatter's rights.

Nothing that LightSquared is doing is wrong, it's the GPS receiver makers who made the mistake, and they want LightSquared to pay for it. We taxpayers pay for it, too, because now that's spectrum the FCC can't sell to anyone, and you can bet the GPS people (the squatters) aren't going to pay for it either.

I say let LightSquared use their spectrum and if anyone has problems they can take it up with the maker of their GPS unit. These tests are meaningless unless they were conducted with GPS receivers that meet their (well known but ignored) filtering requirements.


RE: 10% ???
By JediJeb on 12/12/2011 3:10:43 PM , Rating: 2
Not to say the GPS Unit makers are not wrong in how they designed their units, but if they did design them properly would we still be giving GPS receivers as stocking stuffers or would they still be considered as high end gadgets only companies and rich people played with?


RE: 10% ???
By semiconshawn on 12/12/11, Rating: -1
RE: 10% ???
By Solandri on 12/12/2011 5:35:44 PM , Rating: 4
quote:
What you're missing is that if the GPS folks had played by the rules and used proper filtering in the first place, this wouldn't be an issue. But when GPS began there was no LightSquared, so they cheaped out on the filters since there was nothing there to filter.

No. The spectrum owned by LightSquared was originally used by Inmarsat to communicate with satellites. The satellite signals were about as weak as GPS signals. And the ground station broadcasts to satellites were highly directional. Other bands in that spectrum were reserved for amateur communications to satellites, so again, a similar type of use.
http://en.wikipedia.org/wiki/LightSquared#Spectrum
http://en.wikipedia.org/wiki/L_band#Telecommunicat...

GPS receivers were designed with filters adequate to remove this low level of noise at those frequencies. In 2004 LightSquared got permission from the FCC to repurpose the spectrum for land-based cellular data services. Essentially, the FCC gave them permission to blast away at those frequencies at energy levels thousands of times higher than originally allowed, omnidirectionally instead of pointed straight up. This is what's causing the interference with GPS. The GPS receivers at the time were designed to filter out the FCC-mandated maximum level of noise from those adjacent frequencies. It's the FCC (at LightSquared's behest) which raised those maximums far beyond levels where existing equipment can cope.

Also, many electrical engineers in the industry have come forward to state unequivocally that the frequencies are so close and LightSquared's proposed broadcast signal strengths so high that it is literally impossible to filter it out so that there is no degradation of GPS service. The units which fared well in the test are probably bigger units with better antennas and more power for electronic filtering and signal processing. If LightSquared's project goes live, you can probably kiss the GPS in your phone goodbye.


RE: 10% ???
By knutjb on 12/13/2011 1:01:34 AM , Rating: 2
quote:
The units which fared well in the test are probably bigger units with better antennas and more power for electronic filtering and signal processing. If LightSquared's project goes live, you can probably kiss the GPS in your phone goodbye.
What about those in cars, boats, or worse yet aircraft. Changing these kind of standards in such a rushed manner is dubious at best but prevent drilling for oil or running a pipeline without an extra decade just to make sure it's safe. Hmm....


RE: 10% ???
By Motoman on 12/12/2011 1:54:50 PM , Rating: 1
...within 100 meters of one of their base stations.

So, yeah, it's probably not the greatest goal in the world...but not quite as much of a cataclysm as it would sound without the "100 meters" bit.


RE: 10% ???
By dgingerich on 12/12/2011 2:18:08 PM , Rating: 2
100m = 328ft

Even if the towers are 100ft tall (most cell phone towers are around 30-50ft up) it would put out interference about a block away.

Imagine coming up to an intersection, waiting to have your gps tell you which turn to take, and all of a sudden it loses the GPS signal. You have no idea which way to turn.

Definite interference at 100m means intermittent interference out to three times that. You would be a couple blocks away and all of a sudden have your gps device (or smartphone, or tablet) lose signal and quit giving you directions.

Considering they claimed they'd use a low power mode to prevent the interference, then put out equipment that defaulted to high power mode, I wouldn't trust anything they said. They just want to make money and don't care who they interfere with in the process.


RE: 10% ???
By DT_Reader on 12/12/11, Rating: -1
RE: 10% ???
By dgingerich on 12/12/2011 4:12:30 PM , Rating: 2
quote:
I can apply that to the GPS people who are effectively squatting on LightSquared's spectrum. They just want to steal this spectrum (because stealing the spectrum is cheaper than replacing all those GPS units with ones that work properly) and don't care who they steal it from in the process.


Um, yeah, we'll just tell the US Air Force that, since they are the ones who set up the concept, designs, satellites, and initial devices.


RE: 10% ???
By Bad-Karma on 12/12/2011 10:42:34 PM , Rating: 1
You sir, are squandering the O2 supply.......


RE: 10% ???
By Motoman on 12/12/2011 3:48:37 PM , Rating: 1
Acknowledged. It seemed like the OP was under the impression that it would knock out 10% of all GPS devices across the board. Which would really be a catastrophe...only affecting 10% of GPS devices within 100m is simply a much smaller catastrophe ;)


RE: 10% ???
By fic2 on 12/12/2011 6:51:44 PM , Rating: 2
That isn't what happens with a TomTom GPS. Just used one in New Zealand during vacation. Every time the TomTom would loose GPS lock (frequently) it would just shout out "Turn right here". Usually meaning either off the cliff or into the side of the mountain. I don't know why it was trying to commit suicide, but I would never buy a TomTom. Not to mention even though it had "updated" maps from this year it still didn't know about roads that had been there for 5+ years.


RE: 10% ???
By 0ldman on 12/14/2011 10:55:05 AM , Rating: 2
Generally, at least in the US, if the maps are wrong it is because the government has poor mapping. The rural area I live in is completely wrong. Most county roads are completely backwards from the actual layout and there are several that are off by miles as to where the road actually is.

Whoever is responsible for mapping our area (USGS?) apparently is "close enough", which makes most GPS units useless here.

Comes down to ignorance again.


RE: 10% ???
By Zoomer on 12/12/2011 3:55:49 PM , Rating: 2
IMO, this is totally not lightsquared problem. They got a license to the frequency band at specified power levels, and should be able to use said license. It's not their problem if some one else screwed up before.


RE: 10% ???
By semiconshawn on 12/12/2011 4:48:12 PM , Rating: 2
This is totally a LS problem. Makes no difference who is wrong or to blame. LS is the one with the problem they cant deploy. That is the problem. Nobody else is having any problems.


RE: 10% ???
By DPigs on 12/12/2011 5:40:25 PM , Rating: 2
I have recently acquired mo' money. Can I expect any net change in my number of problems?


RE: 10% ???
By MrTeal on 12/12/2011 5:54:36 PM , Rating: 2
No. Any change in the number of problems is offset by the fact that there are men who, for a certain sum, can make problems "disappear".


RE: 10% ???
By DockScience on 12/12/2011 6:44:51 PM , Rating: 2
This is TOTALLY a LightSquared problem... with some enabling help from the Obama admin (who get lots of donations from the Lightsquared investors)

Lightsquared bought spectrum for the EXPRESS and LIMITED use from satellites.

They then asked their admin cronies to change the spectrum license to allow the same power (15KW) from thousands of ground stations that would have been allowed from satellites. Thus the interference issues.


RE: 10% ???
By bigdog1984 on 12/12/2011 7:51:22 PM , Rating: 3
Why is it that people have no concept of time when posting about political problems? Lightsquared licensed the spectrum in 2004. How does the Obama administration have anything to do with enabling their blunder?


RE: 10% ???
By mcnabney on 12/12/2011 8:19:40 PM , Rating: 3
Didn't you get the memo?

Everything that has ever gone wrong in history is Obama and his time machine's fault.


RE: 10% ???
By Dorkyman on 12/12/2011 10:06:12 PM , Rating: 2
...when in fact we all know it was Bush's fault.

Messiah is a brilliant man, Bush an idiot. Why, Bush went to Yale and got some C's, while Messiah went to Hahvahd and got some...wait... Oh, yeah. He refuses to release his grades. Wow, he must be REALLY smart.


RE: 10% ???
By Black1969ta on 12/12/2011 10:55:21 PM , Rating: 2
Stupid Obama, if he hadn't knocked that Apple off the tree Women wouldn't still be fighting gravity! And why did Newton have to be sitting under that tree anyway!


RE: 10% ???
By hartleyb on 12/13/2011 11:13:06 AM , Rating: 2
The problem is that while you are correct that the license was issued 2004, you should also know it was issued for testing not operation, and the Obama administration tried to get the Airforce to coverup the GPS issue by suppressing testimony.

I say let LS and the administration have their way, and the first time a major airliner crashes becuase of positional error let the people sue LS and Obama.


RE: 10% ???
By Just Tom on 12/19/2011 8:18:53 PM , Rating: 2
The original license was modified to allow for use of terrestrial only stations rather than a combination of satellite and terrestrial stations in January of '11. This waiver, whether wise or unwise, was made by the FCC which is controlled by Obama appointees. If it is an unwise move then Obama should indeed bear the blame; if it is a good move, leading to increased competition and minimal impact on GPS function, then Obama should get the credit.

Not everything is Obama's fault, or his credit, but some things indeed are.


Commi plot to knock out GPS!
By stm1185 on 12/12/2011 1:16:57 PM , Rating: 3
But seriously, 75% interference, that network is not getting built. They should sell off their spectrum and find another way.




RE: Commi plot to knock out GPS!
By Motoman on 12/12/2011 1:18:10 PM , Rating: 3
Well I was just wondering about that spectrum...I know nothing about this other than the article above, but I am left to wonder why the spectrum they bought would have such obvious interference problems with another existing service. Did somebody screw up on the spectrum that these guys got, or what?


RE: Commi plot to knock out GPS!
By MozeeToby on 12/12/2011 1:23:55 PM , Rating: 2
They have to be leaking outside what they were given, there's no way they were licensed on the same frequencies that GPS uses. Someone skimped on their filter design and it they are leaking more than they should into neighboring bands. Most likely it would usually be fine, but GPS is such a low power signal that it's easy to interfere with.


RE: Commi plot to knock out GPS!
By Motoman on 12/12/2011 1:24:46 PM , Rating: 1
Oh, well if it's just leaks that's no big deal. Halliburton and/or BP can seal that right up for them.


RE: Commi plot to knock out GPS!
By DT_Reader on 12/12/11, Rating: 0
RE: Commi plot to knock out GPS!
By DT_Reader on 12/12/2011 2:39:44 PM , Rating: 2
Excuse me, LightSquared!


RE: Commi plot to knock out GPS!
By Solandri on 12/13/2011 2:36:05 AM , Rating: 4
They did not skimp on the filter designs. LightSquared's spectrum was original allocated for satellite communications. That's what the FCC told everyone the spectrum would be used for, and what the GPS receivers were designed to filter out. Nearly undetectable satellite signals raining down and the occasional satellite dish aimed straight up; not towers every 15 miles blasting away in all directions.

To use your analogy, it's like Ford making cars that fit four abreast on the road. There's also a bike lane on the roads, and LightSquared bought a license to operate bikes in that bike lane. But by asking "nicely", they got the government to approve of them hauling oil tankers down the bike lane.


RE: Commi plot to knock out GPS!
By lothar98 on 12/12/2011 3:04:31 PM , Rating: 2
I thought that was one of the the points of having white space gaps between licensed bands was to eliminate licensed signal interference?


RE: Commi plot to knock out GPS!
By Fritzr on 12/12/2011 10:36:23 PM , Rating: 2
A similar fence was implemented by allowing directional broadcast to satellites in orbit & low power broadcast to Earth based receivers. In that application, at the power levels allowed, the sideband noise was being filtered out by the GPS equipment. Unfortunately for Lightspeed, the FCC did not eliminate the sideband noise when they changed the permitted usage. Physics tends to trump bribes no matter what the lobbyists may try to tell you.

Increased broadcast power==increased sideband noise. Existing GPS equipment was designed to ignore the legally allowed noise from neighboring bands. The FCC now needs to modify the GPS license to increase the amount of noise they are required to tolerate or disallow this version of 4G cellphone service on these specific frequencies.


RE: Commi plot to knock out GPS!
By lothar98 on 12/13/2011 3:43:25 AM , Rating: 2
Thank you


RE: Commi plot to knock out GPS!
By MrTeal on 12/12/2011 1:34:00 PM , Rating: 3
The problem isn't the spectrum, it's the GPS receivers. Because GPS signals are so low power, you don't want any attenuation of the signal. Really good sharp filtering is expensive, so many cheap receivers don't have much filtering for out of band signals, and are susceptible to interference. Even good receivers can have issues.


RE: Commi plot to knock out GPS!
By dgingerich on 12/12/2011 2:09:59 PM , Rating: 2
From what I remember, there were arguments about this, from the Air Force and IEEE, before Lightsquared was even sold the spectrum. The FCC still sold it to them, claiming the low power function would not cause problems. This is the same low power functionality they claim will not cause problems now, even though they had the test equipment set to run in high power mode by default.


LightSquared background
By Accord99 on 12/12/2011 5:21:07 PM , Rating: 3
There seems to be some incorrect assumption about LightSquared. Let me try to clarify it.

LightSquared is a company's whose primary business is satellite data and communications. They are now attempting to build a terrestrial LTE network. Currently, their license only authorizes satellite broadcast in their spectrum, with ground transmitters only in areas of poor satellite coverage. The FCC in the past has explicitly forbidden the creation of a purely terrestrial network. Federal regulations also placed all responsibility on the satellite broadcasters to ensure no interference with their ground transmitters and existing satellite users in the same spectrum. This was the regulatory environment that GPS manufacturers operated

Then, just before Thanksgiving 2010, the FCC in an unusual move granted a waiver to LightSquared to eliminated conditions that would have essentially allowed LightSquared to create a terrestrial network in the satellite spectrum. It was unusual since it did not go to a vote before the commission and had an extremely short 1 week public comment period over the Thanksgiving holiday.

However, this move did not go unnoticed and provoked protest from many parties, including the Department of Defense. Because of this, the FCC was forced to modify the waiver and include the condition that the LightSquared LTE network would only be allowed if it showed no interference with GPS receivers.

There was a large-scale test conducted in the first half of 2011 and involved the military, the GPS industry, LightSquared and Federal agencies like the FAA and NASA. The test was based on LightSquared’s original configuration of 2X10 MHz bands. The results were devastating for LightSquared with complete interference to virtually all classes of existing GPS devices. LightSquared hastily proposed a new, but temporary, network configuration using the lower 10 MHz band. This is the first test results based off this new configuration. However, LightSquared has maintained that at some point in the future, it will use the upper 10 MHz band.

LightSquared’s terrestrial network is specified transmit at 1500W, which translates to roughly a billion times stronger signal than GPS signals at the surface of the Earth. Such powerful terrestrial signals have never been allowed in the satellite spectrum and are an important reason why GPS manufactures did not implement filters for illegal signals.




RE: LightSquared background
By mcnabney on 12/12/2011 8:25:35 PM , Rating: 2
What is more important is that Sprint is basing their hopes for deploying an LTE network on this company.

Now that this has doomed Lightsquared, so too are Sprint's LTE hopes. And guess what. Sprint is going to have a hard time competing without LTE and with Wimax which has already been announced as end-of-life. Add in the massive iPhone purchase agreement and Sprint is dead. How can Sprint ever hope to sell an LTE iPhone5 this summer when the only data connection it will have will be EVDO? Stick a fork in Sprint. They are done.

/They really should have known better. They had to write-off about $30B in Nextel investment due to ongoing issues adapting iDEN (which runs on CB radio spectrum!)


RE: LightSquared background
By Just Tom on 12/19/2011 8:38:46 PM , Rating: 2
CB runs at 27 MHz in the US. Nextel's iDen network at 800-900 MHz. It is hard to trust the rest of your analyses when you are so far off on this.


Tractors?
By Visual on 12/13/2011 7:18:23 AM , Rating: 2
So it could affect cars, planes, boats and... tractors? How did you come up with that?




RE: Tractors?
By Quadrillity on 12/13/2011 8:20:34 AM , Rating: 2
Some farming tractors use GPS.


Lightsquared Testing
By Danger3000 on 12/12/2011 9:21:23 PM , Rating: 2
I fly and often transited an area near some of the lighsquared testing. When the FAA was doing Lightsquared testing, they'd always post the advisory "GPS signals may be inaccurate during testing". Not a very comforting message to see, especially when the autopilot is coupled to the GPS. I never noticed any reduction of accuracy (not sure if the test was live when I was in the area), but on final approach on a cloudy, rainy, foggy day a little inaccuracy can do a lot of damage. That's something I *never* want to have to worry about, and neither do you.




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