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LightSquared deals with continued GPS interference  (Source: engadget.com)
U.S. officials say no additional testing is needed to prove the existence of harmful interference

A recent government study found that the LightSquared Inc. wireless service interrupted 75 percent of global-positioning system (GPS) receivers.

LightSquared Inc. is a company looking to offer a wholesale 4G LTE wireless broadband communications network with satellite coverage in the United States. It was founded by Philip Falcone and has had interference issues for years now. Just this year alone, interference concerns were raised by the National Telecommunications and Information Administration (NTIA), USAF Space Command, and the U.S. GPS Industry Council.

Now, a test conducted by the U.S. government has shown that 69 of 92 (75 percent) of receivers experienced "harmful interference" at the equivalent of 100 meters from a LightSquared base station. It was deemed that millions of GPS units were incompatible with the LightSquared service, and it could affect cars, planes, boats and tractors.

The test was performed from October 31 to November 4 for the National Space-Based Positioning, Navigation and Timing (PNT) Systems Engineering Forum, which advises policy makers about GPS issues. The Department of Defense and the Federal Aviation Administration took part in the testing, as well as companies like Garmin Ltd., Trimble Navigation Ltd., Deere & Co., and General Motor Co.'s OnStar unit.

"LightSquared signals caused harmful interference to majority of GPS receivers tested," said U.S. officials in a draft prepared for the review of the LightSquared proposal. "No additional testing is required to confirm harmful interference exists."

LightSquared has proposed that it operate at a reduced power than the levels used during the testing. With low power usage, LightSquared believes its services would only affect 10 percent of devices.

Sources: Business Week, SlashGear



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RE: 10% ???
By dgingerich on 12/12/2011 2:18:08 PM , Rating: 2
100m = 328ft

Even if the towers are 100ft tall (most cell phone towers are around 30-50ft up) it would put out interference about a block away.

Imagine coming up to an intersection, waiting to have your gps tell you which turn to take, and all of a sudden it loses the GPS signal. You have no idea which way to turn.

Definite interference at 100m means intermittent interference out to three times that. You would be a couple blocks away and all of a sudden have your gps device (or smartphone, or tablet) lose signal and quit giving you directions.

Considering they claimed they'd use a low power mode to prevent the interference, then put out equipment that defaulted to high power mode, I wouldn't trust anything they said. They just want to make money and don't care who they interfere with in the process.


RE: 10% ???
By DT_Reader on 12/12/11, Rating: -1
RE: 10% ???
By dgingerich on 12/12/2011 4:12:30 PM , Rating: 2
quote:
I can apply that to the GPS people who are effectively squatting on LightSquared's spectrum. They just want to steal this spectrum (because stealing the spectrum is cheaper than replacing all those GPS units with ones that work properly) and don't care who they steal it from in the process.


Um, yeah, we'll just tell the US Air Force that, since they are the ones who set up the concept, designs, satellites, and initial devices.


RE: 10% ???
By Bad-Karma on 12/12/2011 10:42:34 PM , Rating: 1
You sir, are squandering the O2 supply.......


RE: 10% ???
By Motoman on 12/12/2011 3:48:37 PM , Rating: 1
Acknowledged. It seemed like the OP was under the impression that it would knock out 10% of all GPS devices across the board. Which would really be a catastrophe...only affecting 10% of GPS devices within 100m is simply a much smaller catastrophe ;)


RE: 10% ???
By fic2 on 12/12/2011 6:51:44 PM , Rating: 2
That isn't what happens with a TomTom GPS. Just used one in New Zealand during vacation. Every time the TomTom would loose GPS lock (frequently) it would just shout out "Turn right here". Usually meaning either off the cliff or into the side of the mountain. I don't know why it was trying to commit suicide, but I would never buy a TomTom. Not to mention even though it had "updated" maps from this year it still didn't know about roads that had been there for 5+ years.


RE: 10% ???
By 0ldman on 12/14/2011 10:55:05 AM , Rating: 2
Generally, at least in the US, if the maps are wrong it is because the government has poor mapping. The rural area I live in is completely wrong. Most county roads are completely backwards from the actual layout and there are several that are off by miles as to where the road actually is.

Whoever is responsible for mapping our area (USGS?) apparently is "close enough", which makes most GPS units useless here.

Comes down to ignorance again.


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