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 Lightsquared - GPS Jamming - FCC Pulls the Plug
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HIPAR

USA
29 Posts

Posted - 11 févr. 2011 :  16:29:18  Show Profile  Reply with Quote
Updated 20120215 : FCC pulls the plug on the Lightsquared Network, see details on page 4.
Updated 20110512 : you can follow the testing process here: http://www.pnt.gov/interference/lightsquared/ - in their monthly reports.
Updated 20110311 : GPS industry and users are getting organized -> http://saveourgps.org/ !

Members of the Coalition : Garmin, Trimble, Caterpillar, ATA, etc...
Here is a study on the impact : >> LINK <<






Original post - Has anyone here been following developments concerning interference from the Lightsquared terrestrial network on susceptible GPS devices? Evidently, the GPS industry has conducted laboratory testing that indicates popular GPS devices might be 'jammed'.

http://www.gpsworld.com/gnss-system/news/data-shows-disastrous-gps-jamming-fcc-approved-broadcaster-11029

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gpspassion

93938 Posts

Posted - 11 févr. 2011 :  21:40:17  Show Profile  Visit gpspassion's Homepage  Reply with Quote
Yes, I saw that the other day, it looks really bad based on the preliminary testing. Interestingly it's worse for the FAA certified receivers than for consumer road guidance systems. I suppose it's due to use of high sensitiviy chipsets in mobile car systems, not needed for planes that normally have a clear view and also because they work with lower signals and are less accurate.

The good news is that the FCC will not be able to ignore the results of the planned four month testing period due to start at the end of February.

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offthegrid

USA
399 Posts

Posted - 19 févr. 2011 :  04:52:45  Show Profile  Reply with Quote
They have been approved for testing in 3 or 4 metro areas. I wouldn't be surprised to see that reigned in soon.
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HIPAR

USA
29 Posts

Posted - 20 févr. 2011 :  17:39:38  Show Profile  Reply with Quote
This issue is finally getting the attention it deserves from the Air Force brass.

http://www.airforce-magazine.com/DRArchive/Pages/2011/February%202011/February%2017%202011/GPSinJeopardy.aspx

Although we are concerned with the L1 GPS open signal, the US Department of Defense operates encrypted signals on L1. There are two, the legacy Precision code and the newer Modernized precision code. I would think DoD would want to protect its capability to access these signals on the US mainland. let's hope DoD will be conduct its own testing scenarios.

Baltimore MD will be an interesting test city. There's a busy airport along with major port operations. Thousands of GPS equipped recreational boaters cruise the nearby Chesapeake Bay.

--- CHAS
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gpspassion

93938 Posts

Posted - 24 févr. 2011 :  04:37:59  Show Profile  Visit gpspassion's Homepage  Reply with Quote
An article that goes into some detail : http://www.foxnews.com/scitech/2011/02/23/fast-new-smartphone-network-cause-dangerous-interference-gps-fcc-fears/?test=latestnews

Apparently Lightsquared is saying that only poorly designed receivers will have an issue with their network
quote:
If you have a poor receiver, the outcome is either you get interference, or you restrict the transmitter so much that they’re not able to provide an attractive service.
That's going to add fuel to the fire!

I must admit Lightsquared is a pretty ambitious project since it apparently relies on two-way satellite communication for unlimlited coverage and with a bandwidth of 100+MB/second. Sounds too good to be true ! More info here http://www.lightsquared.com/what-we-do/network/

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gpspassion

93938 Posts

Posted - 25 févr. 2011 :  04:19:41  Show Profile  Visit gpspassion's Homepage  Reply with Quote
Lightsquared is toning it down a notch...and Garmin is revving it up

quote:
Garmin's Gartner said that he's just trying to make sure that the GPS industry has a say.

"We're a little bit concerned that LightSquared is in charge of this whole process, and we're concerned that somehow it's going to be incumbent on the GPS industry to be the ones that find the fix for this," Gartner said.
quote:
"They will send us a letter after the June 15th process to indicate whether they believe the problem has been addressed. We're very optimistic and we've gotten off to a great start," Carlisle [ED - From Lightsquared] said.

"Your guess is as good as mine" as to what happens if the two sides can't agree, Gartner said.
http://www.pcmag.com/article2/0,2817,2380855,00.asp

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Hurston

30 Posts

Posted - 25 févr. 2011 :  12:31:37  Show Profile  Reply with Quote
If all this does go ahead and L1 becomes unusable in places, maybe that will push the US government to decrypt the L2 P(Y) C/A signal.
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gpspassion

93938 Posts

Posted - 11 mars 2011 :  05:16:56  Show Profile  Visit gpspassion's Homepage  Reply with Quote
The GPS industry and users are getting organized -> http://saveourgps.org/ !

Members of the Coalition : Garmin, Trimble, Caterpillar, ATA, etc...

Here is the study : http://saveourgps.org/GPS_Threatened_with_Widespread_Interference.aspx

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HIPAR

USA
29 Posts

Posted - 22 mars 2011 :  00:19:45  Show Profile  Reply with Quote
The Space-Based PNT National Executive Committee is taking this situation seriously. They are going to conduct their own interference study in conjunction with the Lightsquared working group.

The National Executive Committee is sponsored by the US Government and is chaired jointly by the Deputy Secretaries of Defense and Transportation.

http://www.pnt.gov/interference/lightsquared/

--- CHAS

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ve7mdt

Canada
170 Posts

Posted - 24 mars 2011 :  09:45:05  Show Profile  Reply with Quote
This is indeed very interesting. Traditionally, a consumer class electronics has the lowest priority in terms of interference trump card. If you ever take a look at your manuals from your broadcast receiver, cordless phone, baby monitor etc, you will find a note (if it's in the U.S.) that quoted the FCC saying that your device must accept any interference that it may receiver, and it cannot cause interference to others (usually higher class devices, licensed classes etc). So I am not sure if a Garmin nav is considered one of those, but it is usually the case. Your average Garmin nav is not licensed, and is not protected from being interfered with. It's basically "good luck" from the FCC's point of view.

But since this is a big industry and many users are at stake here (i.e. the stake holders could be important users, in the government and commercial domain), it is causing a bigger concern.

Technical point of view: is Lightsquared transmission out of spec? e.g. Are they producing spurious or harmonic interference (i.e. out of their licensed spectrum), and if so, are those signal levels higher than regulation permits? If not, then Lightsquared could claim that they have already fulfilled FCC's requirement by transmitting according to regulations and specs.

Ironic point of view: GPS signal is by nature a DSSS signal (spread spectrum) and by nature rather immune to interference. So this is really a first. Of course nothing can be totally immmune to interference, but DSSS is quite a level higher than your older transmission methods. I'm no expert though.

This reminds me of the long standing interference complaints from 800MHz trunking users (many federal gov etc) to Sprint's iDEN network (inherited from their merger from Nextel). It took years and rarely resolved (both operated in the 800MHz band, but not overlapping, but close).

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gpspassion

93938 Posts

Posted - 24 mars 2011 :  19:45:57  Show Profile  Visit gpspassion's Homepage  Reply with Quote
The technical aspects are a bit over my head, but the gist of the problem seems to be that they are wanting to convert their existing satellite band (that sits right next to the GPS band) for terrestrial use and much more powerful transmissions, the study I linked just above explains that better, as well as the impact on GPS reception in the vicinity of the plannes 40,000 towers.

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ve7mdt

Canada
170 Posts

Posted - 27 mars 2011 :  11:34:32  Show Profile  Reply with Quote
This also reminds me of the Broadband over Power Line (BPL) that was the darling of the broadband push, yet at the same time, a huge interference maker to amateur radio, HF, military, and other users all over. Although newer designed BPL has resolved some (but not all) the interference issues, it was a bit too late for the industry to save itself. Now BPL is nothing but a historical remark, and from being a broadband competitor, to being a telemetry transmission method for internal power companies use. Sure, FCC did not kill it, but it kills itself indirectly.

Will Lightsquared come to a similar fate? I don't know. But spectrum management is all about cooperation, it's like sharing water resources and clean air. So from that angle, it might not get the nod from FCC if the interference is found to be unavoidable (i.e. it is not the fault of simply "cheaply made" receivers as they are trying to spin / paint it).

BTW, not sure if related, about 10 to 20 years ago, there have also been big push of LEO satellites to provide media and broadband and phone services. Many problems came up including interference (to amateur radio and others), budget and financing, market shift, etc, and LEO seemed to have gone vapourware before they were even up. Is Lightsquared one of those era players, and now trying to reinvent themselves in another form?

GPS is too pervasive today, and so this is unlike another kind of challenge.

iPad WiFi w/ RoqyBT to use BT GPSr, LG Optimus G2x, BenQ S6, Samsung Q1, Toshiba e830, Toshiba e805, HTC Advantage X7501, Nextar MN2707 running P7, Magellan Springboard GPS on Visor 2MB, Haicom HI-303III + BT slipper, Holux GPSlim236, eTrex yellow
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gpspassion

93938 Posts

Posted - 29 mars 2011 :  03:07:40  Show Profile  Visit gpspassion's Homepage  Reply with Quote
Had forgotten about BPL...didn't remember LEO though. Not sure what Lightsquared's model is, they certainly hadn't made the headlines until this potential interference with GPS.

According to http://saveourgps.org/related-articles.aspx TomTom has now joined the Alliance and testing has started : http://news.techworld.com/networking/3266108/gps-tests-started-by-lightsquared/?olo=rss - apparently the next update will occur on April 15th...

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HIPAR

USA
29 Posts

Posted - 30 mars 2011 :  04:08:41  Show Profile  Reply with Quote
A major hurtle for Lightsquared will be proving they will not degrade the accuracy and reliability of GNSS avionics equipment that's a basis for the FAA NextGen air traffic control.

GPS/WAAS/EGNOS receivers are certified internationally. More than 100,000 receivers are currently in service. The equipment is stringently specified and performance is verified through extensive testing. GPS landing approaches are authorized at airports throughout the US. Europe is preparing its approach procedures.

These equipments are designed with wide bandwidth filtering admitting the total received power, that is spread over the entire radio navigation band. to enter the receiver. Evidently, that's a criteria for maximum accuracy but there isn't sufficient attenuation of the proposed adjacent Lightsquared power. An organization that sets avionics standards has filed a comment with the FCC warning these equipments were not designed to operate in the forthcoming electromagnetic environment. The preliminary Garmin testing tends to confirm that.

Wide bandwidth receivers are not malfunctioning because the adjacent spectrum is currently utilized for satellite downlinks that don't overpower the the GPS receiver.

--- CHAS
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gpspassion

93938 Posts

Posted - 31 mars 2011 :  06:53:00  Show Profile  Visit gpspassion's Homepage  Reply with Quote
Yes, high accuracy GPS systems that ignore weak GPS signals would likely be hurt the most, actually this is what Garmin's prelimnary studay showed when they compared the impact between a road and an aviation system.

This just in: DOD and DOT weighing in...US Gov't Agencies Slam LightSquared Network Plan
quote:
The DOD and DOT were not sufficiently involved in the development of the work plan for testing LightSquared's network, the agencies told Genachowski in their letter. Calling themselves "the national stewards and global providers" of GPS, the departments said they needed to be actively engaged with the process.

Another problem with the plan for evaluating interference is that there is no requirement for consensus among the various participants, the letter said. "DOD and DOT need to understand how differing conclusions and recommendations developed during the ... process that could affect national security and transportation safety will be addressed," said the letter, which was signed by Deputy Transportation Secretary John Porcari and Deputy Defense Secretary William Lynn.
This brings us back to an early statement by Ted Gartner, Garmin's PR Man, who'd said : "Your guess is as good as mine" as to what happens if the two sides can't agree"!

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HIPAR

USA
29 Posts

Posted - 12 mai 2011 :  20:59:57  Show Profile  Reply with Quote
Some interference observations have emerged through emergency services personnel who participated in live sky tests around a Lightsquared tower:

http://www.gpsworld.com/gnss-system/first-responders-lightsquared-issue-11620

The testing was conducted at Holloman Air Force Base, New Mexico

--- CHAS
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