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gpspassion
93402 Posts |
 Posted - 22 juin 2011 : 00:28:27
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Yes that's what I posted yesterday.
As for the FCC being "sympathetic", there are two things I recently became aware of that have been conveniently "forgotten" in this whole debate :
- Lightsquared already have a dual satellite/terrestrial licence for the 1525-1559 Mhz band
- their "promise" is to bring 4G to the masses. The FCC mandates that they cover 100 million people by 2012 and 260 million by 2015.
Clearly that doesn't mean they should create problems for people who rely on GPS, but they're not doing that on a "whim" as there is value to the community as a whole to have access to high speed mobile data. |
Discounts and Assistance/Réductions et Assistance (Club GpsPasSion) / Où commencer? |
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HIPAR
USA
29 Posts |
Posted - 23 juin 2011 : 20:13:53
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It's true Lightsquared holds a satellite/terrestrial license for the 1525-1559 Mhz band. Prior to that now infamous FCC 'fast tracked' waver, that license didn't authorize 40,000 terrestrial stations.
The GPS industry contends the original license authorized a satellite service with a 'few' terrestrial 'fill ins'. The modified license allows a terrestrial network with satellite 'fill ins'. So, FCC effectively re-purposed spectrum without following rule making procedure. Consequently they inappropriately altered the electromagnetic environment associated with GNSS operations.
--- CHAS |
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HIPAR
USA
29 Posts |
Posted - 30 juin 2011 : 20:01:48
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Hundreds of pages of Lightsquared test data are available for public review at the FCC website. The report is huge and is segmented into multiple documents. For those who are engineering oriented, search for the filings of 06/30/2011.
http://licensing.fcc.gov/cgi-bin/ws.exe/prod/ib/forms/reports/related_filing.hts?f_key=-216679&f_number=SATMOD2010111800239
I superficially scanned through a few of the documents. I'm flabbergasted .. so much coordination, so much intellect, so much work accomplished in so little time. As expected, several detailed filtering presentations are included.
A highly technical analysis of GPS avionics (RTCA) is also there. I still contend Lightsquared vs NextGen airspace is the ultimate challenge. Direct link:
http://licensing.fcc.gov/myibfs/download.do?attachment_key=900115
Internationally, the ICAO is voicing concern. Letter to FCC:
http://licensing.fcc.gov/myibfs/download.do?attachment_key=900180
Perhaps the problem technical specifics are now understood. I think that's the most Lightsquared, industry and FCC can conclude from their massive effort. I didn't find anything outstanding proving the full and complete LTE network can proceed as scheduled.
--- CHAS
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Edited by - HIPAR on 30 juin 2011 20:07:27 |
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wco81
USA
222 Posts |
Posted - 05 juil. 2011 : 01:27:02
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| How did the FCC license this spectrum without realizing this potential conflict? |
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HIPAR
USA
29 Posts |
Posted - 24 juil. 2011 : 17:45:10
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The European Commission has finally commented on Lightsquared's potential to disrupt GNSS receivers. Evidently, they have performed Galileo interference testing:
http://www.insidegnss.com/node/2692
Here's the skillfully written letter addressed directly to FCC Commissioner Genachowski:
http://licensing.fcc.gov/myibfs/download.do?attachment_key=906632
Where is the Russian Federation? Success of everyone's Global Navigation Satellite System depends upon global access. There might also be 'back channel' diplomatic activities relating to this matter.
--- CHAS |
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JGinhisSS
USA
88 Posts |
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gpspassion
93402 Posts |
Posted - 13 déc. 2011 : 09:51:34
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The battle rages on : LightSquared Slams Leak on GPS Tests, Expects to Win.quote:
...LightSquared believes a government official selectively leaked results from tests of its proposed mobile broadband network to set public opinion against the company, and it is seeking a federal investigation of the apparent leak.
But executives of the fledgling carrier, which plans to build a national LTE (Long Term Evolution) network in spectrum near GPS frequencies, said they are still confident of getting government approval in time to launch the network next year.
"The tide is on our side completely in terms of getting through this process," LightSquared General Counsel Curtis Lu said on a conference call with reporters on Monday.
The company believes the U.S. Federal Communications Commission (FCC) will be able to make a decision in the first quarter of next year and will rule in LightSquared's favor, said Martin Harriman, executive vice president of ecosystem development and satellite business. LightSquared has said it could launch the network within nine months of receiving government approval.
Oddly enough there are no more comments about the GPS systems being poorly designed in the first place, at least not the way they should have been to filter our interferences from the then empty adjacent frequencies. This seemed to be a valid argument based on what I'd heard. I guess it's a bit of a mooth point anyway as the receivers are out there now and can't be degraded by the LS network. |
Discounts and Assistance/Réductions et Assistance (Club GpsPasSion) / Où commencer? |
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JGinhisSS
USA
88 Posts |
Posted - 16 déc. 2011 : 04:30:05
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DOD and DOT joint statement- LightSquared interferes with terrain avoidance warning in aircraft : quote:
Preliminary analysis of the test findings found no significant interference with cellular phones. However, the testing did show that LightSquared signals caused harmful interference to the majority of other tested general purpose GPS receivers. Separate analysis by the Federal Aviation Administration also found interference with a flight safety system designed to warn pilots of approaching terrain.
http://www.dot.gov/affairs/2011/dot16411.html |
nuvi 680 - nuvi 500 - nuvi 1690 - nuLink! 1695 |
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gpspassion
93402 Posts |
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HIPAR
USA
29 Posts |
Posted - 18 déc. 2011 : 05:30:15
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Nobody wants to be responsible for flying an airplane into a mountain so I'd say there's a certain amount of theater citing disruption of terrain avoidance systems. However, FAA can present statistics proving controlled flight into terrain is a rare occurrence since aircraft were equipped with these systems.
http://en.wikipedia.org/wiki/Controlled_flight_into_terrain
Let's observe Lightsquared's creativity spinning their way out of this one.
--- CHAS
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cleo43
Canada
149 Posts |
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LER
USA
212 Posts |
Posted - 14 janv. 2012 : 04:49:32
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And LightSquared, Predictably, cries "BIAS". uh huh, right.....
Buh-bye LS. |
Garmin SP2720/7.20 Firmware/GTM-12 (5.50)/CNNA NT 2012.30 (Lifetime)
Garmin Nuvi 1690/3.90 Firmware/CNNA NT 2012.30 (Lifetime)
Garmin Nuvi 3790T/4.70 Firmware/CNNA NT 2012.30 (Lifetime) |
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HIPAR
USA
29 Posts |
Posted - 14 janv. 2012 : 17:25:07
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Yes, Last act of desperation. They don't like the results of testing so they attempt to discredit those who organized the testing. Did they not have their own technical person looking after their interests during the conduct of testing.
http://www.lightsquared.com/wp-content/uploads/2012/01/Letter-NTIA-EXCOMM.pdf
And they are attempting to dump a load of manure on Professor Parkinson. For those who don't know who he is, he was US Air Force project manager who oversaw the development of GPS way back during the 1970's.
--- CHAS |
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wco81
USA
222 Posts |
Posted - 14 janv. 2012 : 18:49:10
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I'm not sympathetic to LS's arguments either.
However, if they got their way, would it be that disastrous? PNDs are cheap now and every year, smart phones and tablets with GPS are probably outselling PNDs by a huge margin.
So would it take that long to turn over the installed base of PNDs and GPS-enabled devices to co-exist with an LTE network as planned by LS?
LS claims GPS devices could have better filtering to work correctly. Not sure if this is a trivial change or would make GPS devices too expensive. But if it's feasible, would it take that long to turn over the installed base?
In return, we'd get another LTE network, which would be a positive thing for the mobile telecom infrastructure in this country. |
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HIPAR
USA
29 Posts |
Posted - 14 janv. 2012 : 20:56:00
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This is bigger than your Garmins, TomToms and iPhones. These devices might already work just fine if Lightsquared operations are confined to the lower half of their spectrum. They only require about 2 MHz of GPS spectrum to provide acceptable personal positioning. That's a realizable filtering problem.
The testing of November 2011 actually indicates many of those devices continue working as is. Failed consumer devices might very well be redesigned and marketable within a year or so.
Lightsquared needs to get past the FAA, DoD and scientific users. That is the equipment where wider filters are required to improve precision and reduce multipath. The required shape factors and environmental stability for these filters are a more daunting design challenge.
JAVAD has demonstrated a precision receiver claimed to be Lightsquared compatible. But don't buy Lightsquared's claims the interference problem is resolved. What has been demonstrated is, if only the lower network channel is operating, the problem appears to be solvable. There remains a problem in binging a half million (or so) fielded receivers into compliance.
Lightsquared's show stopping nemesis is aviation. Testing has indicated lower channel signals degrade GPS avionics .. a terrain avoidance system recently making news. Avionics cannot be modified without triggering lengthy certification rituals.
--- CHAS |
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Lightsquared - GPS Jamming - FCC Pulls the Plug
