Posts Tagged ‘l-band’

FightSquared!

Tuesday, December 13th, 2011

All was well with the GPS world. LightSquared had some trouble surface last June, then the farmers were sold a load of manure. Fine. We can work this out, right?

Not really.

A draft report was leaked and promptly published by Bloomberg, concluding LightSquared will harmfully interfere with 75% of GPS devices.

Philip Falcone’s proposed LightSquared Inc. wireless service caused interference to 75 percent of global-positioning system receivers examined in a U.S. government test, according to a draft summary of results.

The results from testing conducted Oct. 31 to Nov. 4 show that “millions of fielded GPS units are not compatible” with the planned nationwide wholesale service, according to the draft seen by Bloomberg News.

“LightSquared signals caused harmful interference to majority of GPS receivers tested,” according to the draft prepared for a meeting next week of U.S. officials reviewing the LightSquared proposal. “No additional testing is required to confirm harmful interference exists.”

GPS users are the 99% here and I’m afraid the bankers have got something to worry about.

The National Space-Based Positioning, Navigation, and Timing (PNT) Systems Engineering Forum presents its results on 14 December 2011.


The PNT Took My L-band Baby Away

Friday, June 10th, 2011


Seems LightSquared has a problem on its hands, after a report (PDF) from the National PNT Systems Engineering Forum

Key Findings:

  • All GPS receiver applications impacted by proposed LightSquared Network
  • Simulation of fully deployed LightSquared network of ~40,000 base stations would:
    1. Degrade or result in loss of GPS function (ranging, position) at standoff distances ranging from few kilometers and extending to space operations
    2. Out of band emissions due to close proximity to GPS Band
    3. Appear to be satisfactory
  • No universal mitigation approach identified

Seriously, it’s not a good situation, according to Fierce Wireless

Jim Kirkland, vice president and general counsel at Trimble Navigation which has opposed LightSquared’s operations as currently designed, said the tests showed that LightSquared’s network clearly cause interference with GPS.

“There is not a solution here,” he said. “In our view, it’s time to stop squandering resources on this and look for alternative spectrum for this operation. What LightSquared is trying to do is a great thing. It’s very important that we have more competition in broadband and more spectrum in broadband wireless. However, there is one place in the satellite band where this does not work,” and that is the spectrum next to GPS, he said.

It gets worse. According to the WSJ blog post by Amy Schatz, the DoD, aviation and a swarm from Congress are signaling a rough go ahead…

A bipartisan group of 66 House members asked the FCC Tuesday to protect global positioning systems from interference from wireless broadband start-up LightSquared, which is trying to launch a new network.

LightSquared’s airwaves have been knocking out some GPS systems during recent tests in New Mexico, according to unofficial reports from GPS users.

The company has acknowledged the problem but says technological fixes are available. LightSquared and GPS makers are scheduled to file a joint report to the FCC on June 15 about any interference issues.

The aviation industry, Defense Department and other government agencies are worried that the new mobile broadband network’s planned 40,000 cell towers could interfere with highly precise GPS systems used in military, aviation and homeland security equipment. Federal officials and GPS industry advocates have been lobbying Congress heavily to pressure the FCC to resolve any interference issues before letting LightSquared turn on its service.

“We request that the Commission only approve LightSquared’s waiver (to offer service) if it can be indisputably proven that there will be no GPS interference,” the lawmakers wrote Tuesday. A bipartisan group of 34 Senators wrote a similar letter to the FCC last month.

By our count, the House letter was signed by 17 Democrats and 49 Republicans, including four committee chairman: House Armed Services Chairman Howard “Buck” McKeon of California, Science Space and Technology Chairman Ralph Hall of Texas, Small Business Chairman Sam Graves of Missouri and House Foreign Affairs Chairman Ileana Ros-Lehtinen of Florida.

Like a challenge, rocket scientists? They’re hiring!