Lightsquared is dead (these are the guys who wanted to build a low-priced fiber network)

[DainBramaged]

and the primary reason is:


But efforts to build a national network stalled as federal regulators argued the network would interfere with Global Positioning System signals.



I wonder whose pocket those guys are in?




http://online.wsj.com/article/SB10001424052702304192704577404341177350280.html?mod=googlenews_wsj

[Llewlladdwr]

1. Are you arguing that interference with the GPS system is no big deal? NT

[Egalitarian Thug]

3. This has been discussed for months. The only GPS systems effected

are a couple of poorly designed and non-conforming proprietary systems.

At the bottom of this is the same problem we are facing throughout the technology field, well connected thieves creating a captive system from which to extract extraordinary profits while excluding competition.

[Indydem]

4. Educate yourself

"But GPS equipment designed to provide accuracy to within a centimeter or better would still suffer. These high-end units are susceptible to interference because they were purposefully designed with relatively broad RF filters on their front ends. This allows them to sense the timing of GPS waveforms very precisely and also facilitates the reception of what are known as augmentation signals—high-precision corrections to standard GPS location fixes. Awkwardly, these corrections are sometimes broadcast from satellites on frequencies in the mobile-satellite band, near those LightSquared's new system would use.

Can those GPS receivers be modified to cope, perhaps with the augmentation signals being sent on other frequencies? Sure. But it may be too late for calm discussion of such technical fixes. In a December 2011 request to the FCC, LightSquared backed away from its earlier conciliatory offer, arguing that "unlicensed commercial GPS receivers simply are not entitled to interference protection from LightSquared's licensed operations in the [mobile satellite service] band." "Now it's a slugfest," says Barker."

Aviation GPS units, farming equipment, even military GPS receivers were all in jeopardy, and when Lightsquared decided to be assholes, their goose was cooked.

[TroglodyteScholar]

14. +1

If you are into conservation of resources, you should be against Lightsquared simply for the impact they would have had on precision agriculture.

[Egalitarian Thug]

16. Take your own advice.

http://www.democraticunderground.com/1002684539

[Indydem]

2. Fiber? Try poorly designed wireless network,

These asshats wanted to disrupt millions of GPS devices and threw a tantrum when the FCC told them to get bent.

[DainBramaged]

7. Maybe you should go way back on my journal or search the DU archives

I've been on this for a couple of years. And your attacking of them is rubbish.

[Llewlladdwr]

8. Hold the phone there...

You've been on this for a couple of years and don't know the difference between fiber and wireless?

[DainBramaged]

13. (sigh) You really are annoying me. Anyway the company is dead so you appear happy

and with that I'll say find something else you're an expert at to bloviate about.

[Wellstone ruled]

5. When Grassley defends something,run like hell.

[Llewlladdwr]

6. And how would a fiber optic network interfere with the GPS system anyhow?

Are you sure you read the article?

[naaman fletcher]

9. So, do I have this right?

There is a certain spectrum for GPS, and a certain spectrum for Lightsquared.

Lightsquared wants to operate entirely in it's own spectrum.

GPS manufacturers have for years made a shoddy product that is subject to interference from the spectrum next to it. They could have made a product that is not subject to such interference, but chose not to. The FCC has said "hey, that's cool and all that you are going to operate in your own spectrum, and that you have told everyone for years what you plan to do, but the GPS companies are still making a crappy product, so tough luck?"

As a result, we don't get nationwide 4G coverage.

Is that right?

[FarCenter]

10. The Lightsquared spectrum was allocated to satellite downlinks

It is adjacent to the GPS frequencies, which are also satellite downlinks.

Satellite transmitters are not too powerful, and when the signals get to earth, they are quite weak. So a satellite downlink in the Lightsquared frequencies would not interfere with GPS operation because the weak signals would be further attenuated by the selective filters in the GPS receivers.

Lightsquared wanted to reuse the frequencies for terrestrial cellular radio telephony. This involved fairly powerful transmitters and signals that are much more powerful than GPS satellite signals at the GPS receivers. Obviously, things vary depending on the siting of the Lightsquared cell stations, Lightsqared antenna gains, distance from the cell site, location of the GPS satellites, attenuation of Lightsquared and GPS signals by weather and atmospheric effects, and by the design of the GPS selective receiver filters.

So it was probably a reasonable gamble on Phil Falcone's part to bet a few billion dollars of hedge fund money on being able to persuade the lawyers running the FCC that they should ignore technical issues and let Lightsquared build a terrestrial radio system using satellite downlink frequencies.

But it ignored the fact that filters are not perfect notches and that the attenuation versus frequency always has some reasonable roll-off in the filter skirts. Further the GPS receiver designers had built a whole pre-existing industry in a regulatory environment that specified that they would only have to guard against weak satellite downlink signals in the adjacent bands.

The FCC should never have entertained the Lightsquared application to reuse the frequencies in the Bush adminstration.

[naaman fletcher]

12. gotcha. nt

[TroglodyteScholar]

15. NAILED it!

[bananas]

11. Lightsquared used a loophole in the regulations

The frequency band is intended for low-power satellite signals, not high-powered terrestrial transmitters. Lightsquared was trying to use a loophole in the regulations designed to allow ground-based repeater stations for the weak satellite signals. That's why it caused so many technical problems.