LightSquare Testing

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Landis
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Joined: Thu Jan 17, 2008 8:57 pm

LightSquare Testing

Postby Landis » Fri May 13, 2011 12:10 pm

Just saw a Flight Advisory noting that LightSquare is doing some mobile broadband testing in the Las Vegas area. The effective radius of possible GPS outages is 175nm!

https://www.faasafety.gov/files/notices ... visory.pdf

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cozy171bh
Posts: 148
Joined: Mon Jan 07, 2008 4:07 am
Location: Las Vegas, NV

Re: LightSquare Testing

Postby cozy171bh » Sat May 14, 2011 12:10 am

UCAP Gang,

There's also another NOTAM for possible GPS interference for additional testing over Boulder City, which is by the Hoover Dam just to the East of Vegas. The radius is 115 NM, ensuring the interference covers the busy Las Vegas terminal area and portions of Southern California.

I moved into a management position at my airline, working in the flight standards department, but still try to fly at least once a week to check the pulse of the operation. One of my responsibilities is tracking issues like this and sending out notifications to the line pilots and ensuring the dispatch office is forward-thinking on issues like this. Many of our FMS units use GPS updating, others use Inertial with DME/DME position updating. The INS units will be fine, but the GPS units may be affected. We'll see.

What's more, many of the departures and arrivals at McCarran are RNAV based. One departure in particular depends on GPS to the extent that there is a cautionary note that backup VOR reception is required if GPS is unavailable.

The obvious question: If LightSquare, as the company asserts, not an issue for the GPS system, then why do they have to issue a NOTAM when they conduct testing?

With all the mountains surrounding the valley and all the tour traffic in the area, it's a good thing the weather is typically VFR in Vegas.

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sballmer
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Re: LightSquare Testing

Postby sballmer » Sat May 14, 2011 2:55 pm

Great! Just the testing already renders GPS unreliable (i.e. useless) in all of Southern California. Just glad no one lives there... wait... :o

What is the FCC thinking?

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RigaRunner
Posts: 133
Joined: Tue Feb 12, 2008 11:34 pm

Re: LightSquare Testing

Postby RigaRunner » Fri May 27, 2011 10:05 pm

We have a FAA notice (not a real NOTAM) circulating here in the Washington, DC area about future outages of the GPS signal in the vicinity of the Patuxent Naval Air Station. The notice text is here: https://www.faasafety.gov/files/notices/2011/May/PAXR_11-05_GPS_Flight_Advisory.pdf

At the same time, LightSpeed is engaged in a major publicity campaign in the Washington area, buying full page color advertisements in the Washington Post several times per week. The ads say nothing about LightSpeed's potential to interfere with GPS signals, but they are exactly the kind of "public service" communications we routinely see when some company or group is trying to influence the government agencies or Congress.

Maybe it's just a coincidence.
A commercial pilot, IFR rated, who flies a Cirrus SR22 out of JYO.
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plutocrat03
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Joined: Sun Oct 11, 2009 9:45 pm

Re: LightSquare Testing

Postby plutocrat03 » Thu Jun 02, 2011 9:35 am

Preliminary report is that Lightsquare signals DO interfere with GPS navigation

http://www.avweb.com/avwebflash/news/te ... 751-1.html

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RigaRunner
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Re: LightSquare Testing

Postby RigaRunner » Mon Jun 06, 2011 8:51 am

Under the headline, "LightSquared wireless Internet plan concerns officials pushing GPS for aviation" the June 5 Washington Post carries a good explanation of the issues.

As the first sentence puts it: "Two of 21st-century America’s favorite gadgets — the smartphone and the GPS device — are on a collision course, according to a report delivered Friday to the Federal Aviation Administration."

"The report says deployment of a massive new network of towers and satellites to expand wireless communication may effectively shut down Global Positioning System devices that are at the core of a multibillion-dollar plan to revolutionize aviation. They also may affect some GPS units used by drivers, bicyclists and boaters."

The article, written by the Post's aviation reporter Ashley Halsey III, is at: http://tinyurl.com/3oz99js
A commercial pilot, IFR rated, who flies a Cirrus SR22 out of JYO.
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Landis
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Re: LightSquare Testing

Postby Landis » Wed Jun 08, 2011 4:43 pm

So here's a thought: Given the lack of any ground based backup for GPS with the decommissioning of LORAN, and the fact that LightSquare's 40,000 ground based stations will be in fixed locations, what are the chances a system like this could be modified to serve a dual purpose and actually backup GPS? And it could even give us more data in the cockpit. The LightSquared folks should get on this and make it into a win-win situation.

gmarshall
Posts: 298
Joined: Fri Sep 25, 2009 1:54 pm

Re: LightSquare Testing

Postby gmarshall » Thu Jun 09, 2011 12:13 am

Landis wrote:So here's a thought: Given the lack of any ground based backup for GPS with the decommissioning of LORAN, and the fact that LightSquare's 40,000 ground based stations will be in fixed locations, what are the chances a system like this could be modified to serve a dual purpose and actually backup GPS? And it could even give us more data in the cockpit. The LightSquared folks should get on this and make it into a win-win situation.


That is the most levelheaded suggestion I've heard! Though I still think they should bump Lightsquared to a different frequency band.

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RigaRunner
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Re: LightSquare Testing

Postby RigaRunner » Thu Jun 09, 2011 9:45 pm

There is a very informative National Journal article, and a couple of sophisticated comments by radio frequency engineering experts, on the subject of Light Squared's problems at this link:

http://www.nationaljournal.com/hotline/campaign-law-watch/no-static-at-all-gps-industry-disputes-lightsquared-claims-20110608

Interesting also to note that the venture capital firm behind Light Squared seems to be experiencing withdrawals by investors, according to Bloomberg.
A commercial pilot, IFR rated, who flies a Cirrus SR22 out of JYO.
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Laminar
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Re: LightSquare Testing

Postby Laminar » Tue Jun 21, 2011 11:09 am

Light Squared seems to be backing off a bit. They have just purchased a different part of the spectrum for $40 million. I wonder who lost his job over that.

My local newspaper covers it here.


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