[jholly]

ecanderson, on 11 March 2011 - 01:12 PM, said:

jholly, on 11 March 2011 - 10:25 AM, said:

The 4g uses a nearby frequency that does not infringe on the L1 signal. If the GPS receiver does not have enough selectivity to reject the 4g signal then it can cause reception problems.

Have a look at post #38, above. The 4G signal was never supposed to have been allowed in that adjacent band to begin with (reserved for MUCH weaker space-to-Earth signals only). No GPS receiver using L1 should have ever expected to have to reject adjacent band high power terrestrially based transmitters.

I don't disagree with you but I bet the assumption that a stronger terrestrially based transmitters would never be present did lead to some, ah, cost optimizations in the receiver design. Unfortunately this can lead to problems in the future. I'm pretty sure I will never see a fix for my present Garmin, but I suspect the FAA certified receivers for commercial air and probably civil air will be fixed. Hopefully the trucking, train and to a limited extend the shipping industry will be able to bring some weight to bear. I fear my quest for tupperware in the woods will not impress Verizon and others of the need to give a wider berth to the L1 signal. Isn't there also a L5 signal on the horizon for the latest generation GPS birds? Wonder how the 4g will affect that signal. I think the FAA is very interested in that one because it can give greater accuracy and landing improvements. But I might be wrong. Well I suppose it will be an interesting ride. Much like the battle the hams had over the BPL issue.

[yogazoo]

There needs to be more coverage of this by the major media outlets. This really will effect alot of people and the public should be outraged. Given the nefarious backstory it should make for some good play. I've been emailing this story and the appropriate links to the editors of major media outlets asking them to run the story and maybe have them probe a bit deeper. I'm sure, what's been reported on so far with Falcone buying our political system, is just the tip of the iceberg.

The story needs to gain traction with the public to gain momentum. If not, the politicians and bought system will simply serve their master... $$$$$$$$$$$$$$.

[ecanderson]

jholly, on 11 March 2011 - 02:31 PM, said:

I don't disagree with you but I bet the assumption that a stronger terrestrially based transmitters would never be present did lead to some, ah, cost optimizations in the receiver design.

Of course it (ah) did. Nobody designs ANY receiver with vastly (and vastly is the right word in this situation) more sensitivity or selectivity than the application warrants. As I said before, it's not free. There's even a point where it's not even possible. There's no point in building in unnecessary cost in electronic gear.

Let's draw a fair comparison here. You can pick up a simple AM radio that will do just fine for picking up the AM broadcast band. Nothing below the AM broadcast band, and nothing within it, is permitted more than 50KW power in the U.S. (We'll leave aside such Mexican border anomalies as XERF for now). The design of a typical radio can handle adjacent channel interference pretty well. However, even those suffer when trying to listen to a distant station on one frequency (e.g, 540KHz) when there's a boomer 50KW location station on an adjacent channel (550KHz - and we'll leave aside that this particular frequency doesn't allow for 50KW night use - it's JUST an example). Some manufacturers put some extra cash into the selectivity of the unit, and do a better job of rejecting such adjacent channels. Some don't handle it very well at all. But the cost of selectivity, while not free, is at least within reason relative to not doing it. Makes for competition in the market. A professional unit will have better selectivity than your dime store five transistor special.

Now for the ugly comparison. The FCC is suddenly going to let me deploy MEGAWATT transmitters all over the country at 530KHz, focused on urban markets. Yes, megawatt. That's a more than fair ratiometric comparison to 50KW of what's about to happen vs. space signal strength. Good luck with that. Try finding an AM radio that will successfully pull in that signal on 540KHz now. You can't afford one, and so far, nobody makes one. THAT is the moral equivalent of what the FCC did when allowing the adjacent channel terrestrial equipment. It'd be just like allowing megawatt stations to pop up on 530KHz. NO manufacturer would EVER put the kind of money into a consumer rig necessary to reject a signal like that on the odd chance that the FCC would have their collective heads up their collective patoots and allow something like that to happen. And if it did happen, you don't retrofit the receiver to solve the problem. You start over with the hardware design. That's what would be necessary for even the higher end GPS gear to operate with a powerful land-based signal sitting right under L1. Don't expect to see the FAA certified receivers getting upgrades to solve this either. I guess you can keep the case and the display. It's a whole new RF front-end and I.F. section at a minimum. Depending upon how it all pans out, it might not even be practical to build something that would cope with the LS transmitters. We'll have to wait to see what comes of the testing. I understand they have until June to duke it out in the labs, assuming Garmin can procure something that mimics the LS equipment. From what I'd heard, LS wasn't in any hurry to help with that.

[yogazoo]

For what it's worth we should all email the FCC and let them know there's plenty of Americans not happy with their decision to sell us out.

To Contact the FCC Commissioners via E-mail

Chairman Julius Genachowski: Julius.Genachowski@fcc.gov
Commissioner Michael J. Copps: Michael.Copps@fcc.gov
Commissioner Robert McDowell: Robert.McDowell@fcc.gov
Commissioner Mignon Clyburn: Mignon.Clyburn@fcc.gov
Commissioner Meredith Attwell Baker: Meredith.Baker@fcc.gov
General information, comments & inquiries: fccinfo@fcc.gov

This post has been edited by yogazoo: 12 March 2011 - 07:52 AM

[The_Lost_Dogs]

Email addresses: Good. And adding one more:

The Chief of the International Bureau, out of which this item came, is
Mindel De La Torre
Mindel.DeLaTorre@fcc.gov

Other relevant political figures would be your members of Congress

Here are phone numbers

Chairman Genachowski's Contact Information
Room: 8-B201 • Phone: 202.418.1000

Commissioner Copps' Contact Information
Room: 8-B115 • Phone: 202.418.2000

Commissioner McDowell's Contact Information
Room: 8-C302 • Phone: 202.418.2200

Commissioner Clyburn's Contact Information
Room: 8-A302 • Phone: 202.418.2100

Commissioner Baker's Contact Information
Room: 8-A204 • Phone: 202.418.2400

[The_Lost_Dogs]

Also, if you tweet about this, you might want to include "@FCC"

[JBnW]

ecanderson, on 11 March 2011 - 04:41 PM, said:

We'll have to wait to see what comes of the testing.

Speaking of which, has anyone been able to find the preliminary and/or first monthly report from the GPS Users Working Group that were specified in the provisional permit? Seems like the FCC should have at least a couple of those by now...

edit: fat fingers

This post has been edited by JBnW: 14 March 2011 - 10:02 AM

[medoug]

Just to give everyone an idea of the scope of the issue....

We're talking about 40,000 towers positioned worldwide and each could cause a GPS interference area of 3 to 5 mile radius. That covers about 1% of the surface of earth, but this does not account for the vast bodies of water, both poles, and uninhabited areas.

Since land only covers about 29% of the globe, and approximately 90% of our population occupies about 3% of the land, most of civilization lives on only about 1% of the land. This 1% of land is the same 1% of the surface of the earth which will have GPS affected since the towers will be placed in the most populated areas.

Unfortunately, this is the same area where the majority of geocaches are located. If this goes through, you might as well kiss most urban geocaches goodbye. Only the most remote geocaches would be unaffected.

medoug.

[TotemLake]

All that being said, it'll make your smart phone that much more accurate by cell triangulation. Yah? (TIC)

[Bullygoat29]

I hate to be devils advocate on this but we don't know what kind of effect this is actually going to have on the GPS system yet. The only testing that says it interferes is Garmin's testing which was done in a lab. They didn't have the "filter" that LightSquared claims will not cause any interference. We really have to wait for the real world testing to be done. I for one hope there isn't any interference. I can't see the military allowing that to happen.

[yogazoo]

bullygoat29, on 15 March 2011 - 06:05 PM, said:

I hate to be devils advocate on this but we don't know what kind of effect this is actually going to have on the GPS system yet. The only testing that says it interferes is Garmin's testing which was done in a lab. They didn't have the "filter" that LightSquared claims will not cause any interference. We really have to wait for the real world testing to be done. I for one hope there isn't any interference. I can't see the military allowing that to happen.

All true but, the polical backstory is nefarious and the FCC fast-tracking was reckless given the potential impact. I'm still writing my representation in washington about the issue and I'm still emailing and calling the FCC to voice my discontent. The outcome has yet to be decided but once the signals start transmitting from the LightSquared towers, there is no turning back. Given the broadscale concern from everyone in the GPS community the reservations appear to be warranted. Let's put it this way, I'll trust the science and technology editors at GPS World Magazine before I trust Falcone and the FCC.

[Bullygoat29]

I agree with you 100%. I'm really hoping that all of this testing had been wrong and we don't have a problem with both running. I would love to see nationwide 4G and no degredation of the GPS system but we all know that we aren't going to be able to have our cake and eat it too. All the political back door dealings doesn't help the matter either. It's a shame that with enough money you can get what you want no matter how much it might hurt someone else.

[ecanderson]

bullygoat29, on 15 March 2011 - 06:05 PM, said:

They didn't have the "filter" that LightSquared claims will not cause any interference.

I smelled a rat the first time I heard that. Even if LS had some really great control (filter?) and were able to keep 100% of their emissions within their allotted piece of spectrum - no slop or splatter at all at the edges - that still doesn't solve the problem if they're operating with enough power on a frequency close enough to that of the GPS receiver such that proximity to one of those transmitters can swamp the RF electronics of the GPS. If you've ever lived or taken a radio too close to a commercial transmitter site, you'll understand the nature of the problem quite well.

In short - the "filter" has to go on the GPS end, and must be designed in a the circuit board level. I suppose if LS is prepared to buy everyone with an affected GPS a new one... That would certainly change their view of the value of that spectrum they stole!

The simple fact is that proper spectrum management (by the FCC, or the CEPT group in Europe, or whatever agency in a given region) requires that at least SOME buffer space in the spectrum (band gap) exist between known ultra-low power services and other services. That WAS the way L1 was being managed before this fiasco.

As for the ongoing comments about the military, they use - but do not rely upon - GPS signals in the L1 band. While they might be annoyed by all of this, they do have ways to work around it not available to you or me. They have their own GPS channels off in the L2 band - VERY far away in the spectrum (1227.6 MHz) - so as to be unaffected by all of this.

Has anyone heard if LS ever DID assist Garmin in acquiring what LS felt to be representative equipment for the test?

This post has been edited by ecanderson: 15 March 2011 - 08:33 PM

[ecanderson]

Given that this is now the 15th of March, the following section (#41) of the FCC determination is particularly relevant. I'd be curious to know if and when anyone hears that a progress report has been circulated anywhere.

"Further, we require that LightSquared submit an initial report to the FCC and NTIA by
February 25, 2011, that includes a work plan outlining key milestones for the overall analyses. In
addition, LightSquared must submit progress reports on the 15th day of each succeeding month or first
business day thereafter. The first of these reports must at a minimum include base station transmitter
characteristics, categories of GPS devices and their representative performance characteristics, and test
plans and procedures. LightSquared is further required to submit a final report no later than June 15,
2011, that includes the working group’s analyses of the potential for overload interference to GPS devices
from LightSquared’s terrestrial network of base stations, technical and operational steps to avoid such
interference, and specific recommendations going forward to mitigate potential interference to GPS
devices."

[yogazoo]

Here's a link to a growing coalition of large and small businesses, including Garmin, Trimble, TomTom, Caterpillar, and UPS to name a few, banding together to push back against LightSquared. I would encourage everyone here to join the group.

http://www.saveourgps.org/

Their mission statement:

"Representatives of a wide variety of industries and companies have joined the Coalition to Save Our GPS to resolve a serious threat to the reliability and viability of the Global Positioning System (GPS) - a national utility upon which millions of Americans rely every day.

To safeguard GPS, the Coalition seeks a number of remedies from the Federal Communications Commission (FCC), which recently granted a waiver to a company called LightSquared that allows them to repurpose the satellite spectrum immediately neighboring that of the GPS.

LightSquared plans to transmit ground-based radio signals that would be one billion or more times more powerful as received on earth than GPS's low-powered satellite-based signals, potentially causing severe interference impacting millions of GPS receivers - including those used by the federal agencies, state and local governments, first responders, airlines, industry, civil engineering, construction and surveying, agriculture, and everyday consumers in their cars and on handheld devices."


PS: I noticed that Delorme has not been active in this cause and, as far as I know, has not released so much as a statement regarding LightSquared. Is there a reason they don't find this threatening enough to voice concern?

This post has been edited by yogazoo: 15 March 2011 - 09:48 PM

[tozainamboku]

ecanderson, on 15 March 2011 - 08:24 PM, said:

bullygoat29, on 15 March 2011 - 06:05 PM, said:

They didn't have the "filter" that LightSquared claims will not cause any interference.

I smelled a rat the first time I heard that. Even if LS had some really great control (filter?) and were able to keep 100% of their emissions within their allotted piece of spectrum - no slop or splatter at all at the edges - that still doesn't solve the problem if they're operating with enough power on a frequency close enough to that of the GPS receiver such that proximity to one of those transmitters can swamp the RF electronics of the GPS. If you've ever lived or taken a radio too close to a commercial transmitter site, you'll understand the nature of the problem quite well.

I would if the GPS signal were like a commercial radio or television transmission.

The GPS signal is actually designed to be robust under noisy conditions such as someone broadcasting in an adjacent frequency band. All the GPS satellites transmit at the same frequency. Essentially what the receiver needs to do is to lock on to the pseudo random code from each satellite in order to pull it out of the noise. Because GPS works this way, noise from broadcast in adjacent frequency (and even low levels of noise in the same frequency band) generally only means that it might take longer to get a lock. Of course at some point noise will drown out the signal altogether and the receiver won't be able to lock or will lose lock. My guess is that LightSquare believes they can control their emissions with filters so that a GPS receiver could still lock onto the very weak satellite signal. They probably feel that unless you are standing right next to one of their transmitters, at worse a GPS receiver will simply just take longer to get a lock. Their signal is fundamentally different from GPS jammers that generate specific noise that masks the pseudo random code and GPS spoofers that attempt to spoof the same pseudo random code as a satellite. The LS signal is carrying data that is uncorrelated to the GPS satellite random code and at a much higher bit rate, so its effect on the GPS signal should not be so great. But of course, this needs to be tested.

[ecanderson]

tozainamboku, on 15 March 2011 - 10:07 PM, said:

ecanderson, on 15 March 2011 - 08:24 PM, said:

I smelled a rat the first time I heard that. Even if LS had some really great control (filter?) and were able to keep 100% of their emissions within their allotted piece of spectrum - no slop or splatter at all at the edges - that still doesn't solve the problem if they're operating with enough power on a frequency close enough to that of the GPS receiver such that proximity to one of those transmitters can swamp the RF electronics of the GPS. If you've ever lived or taken a radio too close to a commercial transmitter site, you'll understand the nature of the problem quite well.

I would if the GPS signal were like a commercial radio or television transmission.

OK - I'm making lots of analogies here to try to get the technical side of this across without undue pain. Some of those analogies are better than others. The concept I was trying to get across is that you can overload the front end of any receiver with enough power, understanding that proximity increases the effective power. You allude to this yourself:

Quote

Of course at some point noise will drown out the signal altogether and the receiver won't be able to lock or will lose lock.

That's what I meant when using the somewhat un-technical but commonly used word "swamp" to describe this in the prior post. At some point, the finest DSP chip made can't sort it out. Initial testing with a consumer grade Nuvi and a Garmin aviation unit says this is precisely what happens, and the distances they projected for interference, and finally loss of lock, were not good. The Nuvi was projected to become useless at about 2/3 mile from the transmitter, and the GNS 430W aviation unit at an astounding 5-1/2 miles out. Without seeing the test plan, it's impossible to know whether these initial findings will continue to hold in final testing, but if they are even remotely indicative of what the LS equipment causes, it's a non-starter.

Given the significant hit to the Garmin aviation unit, and the dramatically increased dependence upon GPS by the aviation industry and FAA, I believe that we have no real reason to fear the end result of all of this. Someone will either sort out the problem to (at a minimum) the satisfaction of the FAA, or the FCC will have to put its collective tail between its legs and retract its conditional authorization for the LS request for 'deviant' use of the spectrum. Or, as I suggested a number of posts ago, the entire enterprise may fail on its own. The plan may fail due to 1) underfunding, even with half of Falcon's money already in the pot (40,000 sites is a bunch of equipment to buy, negotiate site costs for, and maintain) or 2) Falcone might not be in a position to see the deal through due to his SEC issues, or 3) members of the US Congress may prevail upon the FCC to review their very "unique" handling of the LS petition - which could still be denied out of hand if the politics eventually go the wrong way.

This post has been edited by ecanderson: 15 March 2011 - 10:44 PM

[yogazoo]

The first report to the FCC was issued yesterday. http://www.insidegnss.com/node/2517

In summary, testing methodology was established. That's about it.

[t4e]

interesting article on the same website

http://www.insidegnss.com/node/2466

[JBnW]

There ya have it, folks.

[TotemLake]

It IS April 1. I'll wait for followups.

[yogazoo]

I'm calling a giant pile of BS on the whole story. I see you STARBRAND. My question for starbrand is did you create that website just to pull that 04/01 prank?

You had me going until I realized just how absurd the premise was.

Could you imagine fighter pilots navigating with gloirified smartphones? How about GPS guided missles? Is there an App for that?

If you go to the HOME page on that website you'll see StarBrands signature avatar. Funny

This post has been edited by yogazoo: 01 April 2011 - 10:11 PM

[JBnW]

Moving along from the humbugs; looks like this article was missed. As poorly as "insidegnss.com" reports the FCC's action, it would be great to see what DoD and DoT actually had to say. Should also be seeing the April 15 Working Group report anytime soon...somewhere.

[ecanderson]

Speaking of which, the next monthly report from the committee was due this this/last week. Anyone see it?

[JBnW]

Another Op-Ed article, but no word on the April Working Group report. Has anyone been able to find it?

[yogazoo]

April 15th Report - Link

[JBnW]

yogazoo, thanks! Was beginning to wonder if they missed their deadline or what. My very preliminary speed-read would show this as the important part:

Quote

Since the first progress report, the sub‐teams have been meeting regularly and have been focused on
identifying qualified laboratories for testing activities, developing test plans and identifying devices,
receivers, and systems to be tested, making arrangement for testing, and/or commencing testing. The
current draft test plans and the current list of devices and receiver models submitted for testing by
companies are included in attachments to this second progress report; any updates to these will be
included in the May 15 progress report. Each of the receiver category sub‐teams will report on their
progress to date in these areas. Test results will be published in the final report and the identity of
each tested receiver will be randomly coded within each category.

The TWG has met weekly, including in person and/or via teleconference to monitor and review subteam
progress and to address matters of general applicability across sub‐teams.

And, I'll not post the entire list, but Appendix B staring on page 17 of the PDF lists the devices to be tested...an interesting list.

Will digest more, but looks like they're getting up and running with testing, and the juicier parts will come later.

Thanks again for finding it!

[The_Lost_Dogs]

For those that might be interested.... a free and open event relevant to this topic.

Can the FCC Convert Satellite Spectrum into Wireless Competition?

Thursday, May 12, 2011
12:00 p.m. - 1:45 p.m.

National Press Club
Holeman Lounge
529 14th Street, NW
Washington, DC 20045

RSVP



Last year's National Broadband Plan promised to unlock 500 MHz more spectrum to meet the exploding consumer demand for mobile data applications. Aside from the TV band, the largest source of new spectrum is held by Mobile Satellite (MSS) companies seeking the flexibility to compete with the large mobile carriers. Last year a new company called LightSquared received conditional FCC authority to use previously restricted MSS spectrum to build out an open wholesale-only wireless network covering at least 260 million Americans by 2015.

While the potential consumer benefits of a first-ever wholesale wireless network are large, so is the controversy around whether the FCC's policy will really add meaningfully to competition in an industry consumer advocates and regional carriers say is rapidly trending toward duopoly. Can a wholesale MSS network make connectivity a commodity for a growing diversity of uses, or will it lack the capital and customers to survive against the dominant carriers?

Please join us for this luncheon, keynoted by LightSquared CEO and wireless pioneer Sanjiv Ahuja, followed by a discussion panel featuring leading experts and industry stakeholders.



Lunch will be provided.



Keynote Speaker
Sanjiv Ahuja
Chairman and CEO, LightSquared

Panelists
Reed Hundt
Former Chairman, FCC and Principal, REH Advisors LLP

Parul Desai
Communications Policy Counsel
Consumers Union

Bill Ingram
Senior Vice President Strategy
Cricket/Leap

Larry Krevor
Vice President Government Affairs
Sprint Nextel

Michael Calabrese
Senior Research Fellow and Director, Wireless Future Project
New America Foundation

Moderator
Sascha Meinrath
Director, Open Technology Initiative
New America Foundation



To RSVP for the event, click on the red button or go to the event page:

http://www.newameric...rum_competition


For questions, contact Stephanie Gunter at (202) 596-3367 or gunter@newamerica.net.

[ecanderson]

May 16th has come and gone, and I haven't seen anything of the required report from that date. Has anyone seen anything from the Working Group for May as yet?

[JBnW]

ecanderson, on 20 May 2011 - 09:06 AM, said:

May 16th has come and gone, and I haven't seen anything of the required report from that date. Has anyone seen anything from the Working Group for May as yet?

The GPSworld link above had a new letter and field reports from a 911 drill in New Mexico doing some drills near one of the towers. Not scientific and not much detail to go on, but the responders did report significant interference with commercial GPSers.

It appears that the reports take a few days to filter down to the public, though.

[ecanderson]

Looks like a Webinar to discuss the May report is scheduled for 10:00 Pacific on May 26th. It's not clear who the "experts" will be, but the listing says that "panelists will represent the high-precision sector, aviation, consumer handsets, and timing infrastructure."

You can sign up here if you're interested in hearing it: https://event.on24.c...&eventid=311442

[JBnW]

While still waiting for someone with better google-foo than me, I found this FAA advisory for portions of Nevada. Not the report that we're waiting for, but apparently they are/were doing some larger scale tests. Still, they are required to provide monthly reports.

[ecanderson]

JBnW, on 23 May 2011 - 05:15 AM, said:

While still waiting for someone with better google-foo than me, I found this FAA advisory for portions of Nevada. Not the report that we're waiting for, but apparently they are/were doing some larger scale tests. Still, they are required to provide monthly reports.

The FAA is certainly taking a pessimistic/cautious view of that test. They're talking about unreliable/unavailable GPS in a 115 nautical mile radius, and from ground level to 30K feet!

[yogazoo]

My biggest fear in all of this is that the GPS manufacturers will be made to tighten the receiver filtering as a part of a solution. This will likely play out in one of two scenarios. 1) The GPS manufacturers will "upgrade" the current models on the market, or 2) The current models on the market will become much less desireable and new models will have improved filtering.

Either way, I'm not rushing out to buy a bunch of new GPSr's until this whole FCC/LightSquared thing is resolved (June 15th?).

[ecanderson]

The idea of retrofitting an existing unit - not gonna happen. It's not like changing the filter on your furnace. After what I've read of the initial look at the problem, it isn't a simple one of adjacent channel interference .. it's complete front end overload.

The idea that this will be resolved by 15 June - call it 1 chance in 100,000. The p***ing contest that will ensue after the report is complete will take far longer than that.

[ICHTHYS]

Here's an Article I just read on it:

Working group seeks to address perceived problems with GPS signal interference
A few weeks ago, I wrote a story about potential interference with Global Positioning Satellite (GPS) signals due to the deployment of a new cellular telephone and data network by a communications company called LightSquared. When I was preparing that article I attempted to contact LightSquared to get their side of the issue, but got no response to my emails and phone calls. After the story ran, LightSquared did reach out to me, and on April 28, 2011, I spoke via phone with Jeff Carlisle, their executive vice president for regulatory affairs and public policy.
LightSquared is historically a satellite telephone services company, founded in 1989. They launched their first communications satellite in 1996, and have a wide range of clients using their services, including many public safety agencies. Carlisle pointed out that LightSquared is the only provider of a push-to-talk satellite-based network that can be provided on an ad hoc basis to first responders.
The frequency band that LightSquared licenses from the FCC is underused by their satellite subscribers. In 2001, LightSquared petitioned the FCC to repurpose this frequency band for a combination of satellite and ground-based wireless communications. When users were within range of a ground station, their communications would run through that system, as with conventional cellular telephone service. When users were out of range of a ground station, their handset or data modem would communicate with an overhead satellite. The switch from ground to satellite communications would be seamless and transparent to the user.
Because LightSquared’s portion of the communications spectrum is adjacent to the channels used by the GPS network, the GPS community expressed concern that LightSquared’s ground-based signal would bleed into the GPS bands and overwhelm the relatively weak transmissions from the GPS constellation, roughly 13,000 miles away from the typical GPS receiver.
LightSquared responded to this issue by spending $9 million to develop filters to ensure their signals would not interfere with GPS transmissions. Carlisle says these filters are 1000 times more effective than the FCC required in a 2003 ruling. In 2004, the GPS industry indicated to the FCC their support for LightSquared’s technical parameters.
GPS frequencies lie within bands designated L1 to L5, with the L1 band being closest to the LightSquared spectrum. In 2010, the GPS industry told the FCC that some GPS receivers “look” outside of the GPS bands, and strong transmissions in the adjacent frequency bands — namely, the ones used by LightSquared — could render those receivers useless. Many receivers do not have appropriate filtering because of older technology or poor design, and can pull in signals outside the designated GPS bands, so that a strong adjacent transmission could overwhelm the GPS signals.
Carlisle co-chairs a working group to resolve this problem with Charlie Trimble who founded Trimble Navigation, a major GPS manufacturer. There are seven subgroups within the working group that include representatives from Garmin, APCO, Boeing, Rockwell, Lockheed-Martin, public safety organizations, the Dept. of Defense, NASA, and the FAA. Testing of solutions is underway, with a final report to the FCC due on June 15, 2011.
The FCC-mandated testing process is evaluating 150 different GPS devices. After that testing is complete, mitigation solutions will be explored by all the parties. Carlisle assured me that both the FCC and LightSquared are cognizant of the critical role that GPS has not only for land, sea, and air navigation, but for maintaining other aspects of our infrastructrure.
We’ll all still be able to find Grandma’s house at Thanksgiving.

[yogazoo]

That last line is extremely condescending. How about Airplanes will still be able to land safely, or Emergency crews will still be able to pinpoint your address in an emergency.

This story is nothing but one sided talking points. Quoting someone other than a LightSquared exectutive would have been nice.

ICTHYS, how about a citation? Publication? Writers name? Anything that I can see where this BS was posted.

This post has been edited by yogazoo: 24 May 2011 - 03:37 PM

[yogazoo]

Never mind, I found it. The article is from "Police Tech & Gear" Author: Tim Dees.

Tim is a criminal justice instructor. Tim may be a decent writer but hardly someone I'd want to get my information in Satellite transmission and GPS technology from. Obviously not versed enough to question some of the spoutings from Carlisle. It's a good thing that this article will never show up on a Google search of "LightSquared, GPS, Interference, Technology"

This post has been edited by yogazoo: 24 May 2011 - 03:37 PM

[JBnW]

Apparently, the May 16th report has been released, but danged if I can find it! However, here is someone who has, and an interesting read about the recent Las Vegas tests.

[ecanderson]

If my geolocation job was successful, they were testing on an existing tower on the NW side of Boulder City (just SE of Las Vegas a bit). As an aside, local agencies in Boulder City reported poor GPS results anywhere near the test site.

[coggins]

JBnW, on 31 May 2011 - 05:45 AM, said:

Apparently, the May 16th report has been released, but danged if I can find it! However, here is someone who has, and an interesting read about the recent Las Vegas tests.

Looks like Light Squared is blocking your link too

[ecanderson]

coggins, on 31 May 2011 - 07:32 AM, said:

Looks like Light Squared is blocking your link too

I only found it to be malformed when I tried it. Just delete the superfluous stuff on the front end and it works.

[dbrierley]

The report seems to be at:

http://licensing.fcc...ment_key=889555

Congress is trying to slow things down:

http://www.insidegnss.com/node/2629

LightSquared is planning an initial public offering (IPO):

http://www.fiercewir...ally/2011-05-27

[ecanderson]

DBrierley - thanks for picking up those links. The previously cited article complained that LS was using a signal whose ERP is -3db (half power) of that projected by the license. I discovered in the report that it's actually far less than that at -6db (quarter power) of the projected ERP. I'm beginning to wonder about the test parameters. From the report to which you pointed us:

Testing is occurring during the period from May 16th to 27th, from midnight to 6AM (local time) daily.
LightSquared is using base stations identical to the ones which it will use for its network deployment;
however due to unique circumstances of the test setup, in single frequency mode, the test sites will
operate at power levels of approximately 59 dBm EIRP per channel as opposed to the 62 dBm EIRP per
channel currently planned for LightSquared's initial commercial deployment. For two carrier tests, the
MIMO gain will not be present, reducing the EIRP a further 3 dB per channel to approximately 56 dBm
EIRP (see Note 1 in Appendix G).

There's a whopping difference between 56db and 62db. No matter. Local agencies were still clobbered per their own reports.

As for an IPO - there's no way Falcone is going to start a road show with the cloud of this testing and congressional 'approval' hanging over his head. He'd have to price LS as a penny stock.

This post has been edited by ecanderson: 31 May 2011 - 08:33 AM

[jholly]

ecanderson, on 31 May 2011 - 08:29 AM, said:

As for an IPO - there's no way Falcone is going to start a road show with the cloud of this testing and congressional 'approval' hanging over his head. He'd have to price LS as a penny stock.

Didn't pay attention during the dot bomb era, eh? Plenty of startups with a desktop server and a virtual warehouse for the inventory sold their stock for a big bundle. Plenty of investors out there willing to get on the band wagon hoping for the next google.

[ecanderson]

jholly, on 31 May 2011 - 08:55 AM, said:

Didn't pay attention during the dot bomb era, eh? Plenty of startups with a desktop server and a virtual warehouse for the inventory sold their stock for a big bundle. Plenty of investors out there willing to get on the band wagon hoping for the next google.

Too late, Holly. That was Yandex. Your chance has already come and gone for this week (Nas: YNDX). The rest of the money remains on the sidelines - perhaps until November '12.

[ecanderson]

More tidbits starting to come out. Here's the executive summary of the anticipated impact on aviation GPS use, written 26 May (not a pretty conclusion):

http://www.pnt.gov/i...TCA-ExecSum.pdf

Looks like there's more to the tests in New Mexico (vs. Nevada). Them boys what make the cool John Deere hats aren't none too happy, neither:

http://licensing.fcc...ment_key=891387

[jholly]

ecanderson, on 02 June 2011 - 02:00 PM, said:

More tidbits starting to come out. Here's the executive summary of the anticipated impact on aviation GPS use, written 26 May (not a pretty conclusion):

http://www.pnt.gov/i...TCA-ExecSum.pdf

Looks like there's more to the tests in New Mexico (vs. Nevada). Them boys what make the cool John Deere hats aren't none too happy, neither:

http://licensing.fcc...ment_key=891387

Looks down right ugly. And if Deere is not happy, Archer Daniels Midland won't be happy either.

[dbrierley]

Symmetricom claims to have a solution for LightSquared:

http://urgentcomm.co...rence-20110601/

[ecanderson]

dbrierley, on 02 June 2011 - 02:48 PM, said:

Symmetricom claims to have a solution for LightSquared:

http://urgentcomm.co...rence-20110601/

If I'm reading that right, Symmetricom's 'solution' is only worried about whether the cell site's own GPS reception would be degraded, screwing up local TDMA timing - and wouldn't do diddly to improve the situation for other GPS units. I think they're misreading the larger problem entirely.