UPDATE: Potential disruption to GPS users.

[+PFF]

There has been grave concern over the proposed establishment of a nationwide wireless broadband network consisting of up to forty thousand high-powered transmitters operating immediately next to the spectrum allocation for GPS satellites. After a outpouring of criticism from GPS manufacturers, the Coast Guard, the FAA, plus many police/fire organizations, the Government mandated testing to determine the extent of interference LightSquared's operation would cause.

 

The tests were conclusive. As any Ham Radio operator could have predicted, interference with GPS technology (i.e.; receiving weak signals from space) was a certainty. [is there NO ONE remaining at the FCC who has any actual experience with radio communications?)

 

LightSquared initial position was that GPS manufacturers would "just have to do a better job designing receivers". That idea did not fly very far! Not only is it an impossible task, but what about the millions of receivers already in use around the World?

 

Facing strong and increasing resistance, LightSquared has agreed to move some of its operations to another frequency and to reduce operating power. Most importantly, LightSquared will not be allowed to begin operation until the interference issue is resolved. Meetings with GPS user groups are continuing at this time.

 

Article at: http://wraltechwire....ogpost/9753070/

 

-Paul-

 

Celebrating 50 years as a licensed Amateur Radio operator (June 16, 1961)

[holograph]

There is a web site devoted to the issue: http://www.saveourgps.org/

 

This was a classic case of big-money expecting to dominate the regulatory agency, as has so often succeeded in the past. LightSquared was funded by one of the multi-billion-dollar hedge funds, and got the OK from the FCC to construct the infrastructure pending the outcome of the tests. I suspect that they expected to get approval as a result of their fait-accomplie: "hey we've already spent a billion or so and constructed the network on your preliminary OK, so you have to approve it now, don't you?"

 

Their claim has consistently been: hey, the older GPS receivers were crappy, and should not have been sensitive to signals outside their allocated band. So it's not our fault if our signal disrupts them. They should all be replaced by receivers that have narrower filters.

 

I'm surprised that the GPS manufacturers weren't also enthusiastically supporting LightSquared , since it would have meant that all those old GPS receivers would have to be replaced.

 

You may want to curb your enthusiasm for the latest ruling, because Congress only said that LightSquared must not interfere with DoD and Homeland Security application of GPS. If LightSquared can do that, but still ends up disrupting civilian GPS I'm not sure anyone would object, since it means forced replacement of all those "cheap" consumer GPS units.

[Bill93]

LightSquared has claimed GPS receivers were not well designed, but in fact they were mostly designed to work with the regulatory conditions in existence. The frequencies that LS was proposing to use were allocated as a satellite band. LS used a loophole that allowed some low-power terrestrial transmitters as fill-in for poor coverage areas, and suddenly wanted to make most of their transmitters terrestrial.

 

The power ratio for a nearby terrestrial transmitter versus a satellite transmitter is so large that it is a major design problem to build a receiver that will separate them. That problem grows worse for frequencies that are essentially adjacent channels like the band LS wanted to use, almost adjacent to GPS L1.

 

The FCC should have the technical savvy to understand this. For many decades they have regulated AM, FM, and TV broadcast station allocations in such a way as to minimize adjacent channel interference.

 

I'm not surprised at the idea of changing frequency bands. Some commentators have been saying all along that LS had a strategy of letting the fuss develop, then making an even trade the band of spectrum that they acquired license for relatively cheaply, for a band of spectrum that would have cost them many times as much on the open market. That may be happening now.

 

I have not heard what the new frequency allocation would be, nor any real analysis of how much that will ease the GPS problem.

 

I wrote both of my senators to tell them that they should make the FCC preserve the enormous investment we all have in GPS. You can do the same.

[Bill93]

Another update. LightSquared is discussing a slight move in frequency which will help many GPS applications avoid interference, but does not protect precision GPS as used by surveyors, construction machine control, and agriculture.

 

http://www.gpsworld.com/survey/lightsquared-high-precision-receivers-are-collateral-damage-11802

[+DragonsWest]

Another update. LightSquared is discussing a slight move in frequency which will help many GPS applications avoid interference, but does not protect precision GPS as used by surveyors, construction machine control, and agriculture.

 

http://www.gpsworld.com/survey/lightsquared-high-precision-receivers-are-collateral-damage-11802

 

Well, it's simple. As LightSquared aren't even established they are the least impacted target. They'll have to go.

[+shorbird]

From today's Washington Post:

 

http://www.washingtonpost.com/blogs/post-tech/post/lightsquared-interferes-with-gps-report/2011/06/30/AGXhyAsH_blog.html?wpisrc=nl_tech

 

LightSquared interferes with GPS: Report

By Cecilia Kang

LightSquared’s wireless network interferes with global positioning systems, according to tests the company and the GPS industry submitted to federal regulators Thursday.

 

But that’s where their agreement ends.

 

LightSquared, a startup created by hedge fund investor Philip Falcone, said it still thinks it can figure out a way to get its satellite-based mobile broadband network to work without knocking out GPS receivers. Among other things, the company says filtering technology — for its own devices and for GPS devices — can help reduce interference.

 

But the GPS industry disagrees.

 

“There is no existing technology that solves this interference, only unproven claims of hypotehtical future fixes,” said Jim Kirkland, vice president of GPS firm Trimble.

 

The FCC said it won’t allow LightSquared to launch its business until the interference issues are resolved. Spokesman Neil Grace said the agency will review the report it received Thursday.

 

“The FCC has a long-standing record of resolving interference disputes based on engineering data,” Grace said. “Our nation cannot afford to let spectrum go underutilized. America's economic growth and global competitiveness are on the line.”

 

Much is at stake in Falcone’s venture. His firm, Harbinger Ventures, put about $3 billion into the mobile broadband firm. LightSquared, based in Reston, has signed wholesale wireless leasing agreements with Leap Wireless and Best Buy. UBS and JP Morgan put $586 million into the firm this year.

 

The company has touted its potential to bring more competition to the telecom industry. Its satellite service can provide mobile broadband service to rural areas. If you are a game console maker or big-box retailer, you can lease LightSquared’s wireless network and bypass carriers such as AT&T and Verizon. Consumer groups have lamented a potential decline of competition among wireless carriers with AT&T’s bid to merge with T-Mobile.

 

The tests, required by the FCC, showed significant interference. Construction companies such as Caterpillar and John Deere said interference could potentially lead a tractor to run into a gas line. The aviation industry warned that flight safety was jeopardized.

 

But LightSquared asked the GPS industry to cooperate to find ways for both technologies to co-exist.

 

“This issue will be resolved by good data, smart engineers and good-faith problem-solving dialog,” said Sanjiv Ahuja, LightSquared CEO.

 

This post has been updated since it was first published.

 

By Cecilia Kang | 11:43 AM ET, 06/30/2011

[Wintertime]

The tests were conclusive. As any Ham Radio operator could have predicted, interference with GPS technology (i.e.; receiving weak signals from space) was a certainty. [is there NO ONE remaining at the FCC who has any actual experience with radio communications?)

Oh, you don't want to ask that question, Paul! The answer is too depressing...

 

I have a friend on a local Usenet group who used to be an FCC field engineer. He's deeply discouraged by the failure of the current Commission to take a strong stand against interference.

 

Celebrating 50 years as a licensed Amateur Radio operator (June 16, 1961)

Congratulations! I'd be celebrating the same milestone soon if I had gotten licensed when I first threatened to. As it is, I'm only a bit over 30 years.

 

K5PF de N6BIS...