backtop


Print 45 comment(s) - last by Just Tom.. on Dec 19 at 8:38 PM


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



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

LightSquared background
By Accord99 on 12/12/2011 5:21:07 PM , Rating: 3
There seems to be some incorrect assumption about LightSquared. Let me try to clarify it.

LightSquared is a company's whose primary business is satellite data and communications. They are now attempting to build a terrestrial LTE network. Currently, their license only authorizes satellite broadcast in their spectrum, with ground transmitters only in areas of poor satellite coverage. The FCC in the past has explicitly forbidden the creation of a purely terrestrial network. Federal regulations also placed all responsibility on the satellite broadcasters to ensure no interference with their ground transmitters and existing satellite users in the same spectrum. This was the regulatory environment that GPS manufacturers operated

Then, just before Thanksgiving 2010, the FCC in an unusual move granted a waiver to LightSquared to eliminated conditions that would have essentially allowed LightSquared to create a terrestrial network in the satellite spectrum. It was unusual since it did not go to a vote before the commission and had an extremely short 1 week public comment period over the Thanksgiving holiday.

However, this move did not go unnoticed and provoked protest from many parties, including the Department of Defense. Because of this, the FCC was forced to modify the waiver and include the condition that the LightSquared LTE network would only be allowed if it showed no interference with GPS receivers.

There was a large-scale test conducted in the first half of 2011 and involved the military, the GPS industry, LightSquared and Federal agencies like the FAA and NASA. The test was based on LightSquared’s original configuration of 2X10 MHz bands. The results were devastating for LightSquared with complete interference to virtually all classes of existing GPS devices. LightSquared hastily proposed a new, but temporary, network configuration using the lower 10 MHz band. This is the first test results based off this new configuration. However, LightSquared has maintained that at some point in the future, it will use the upper 10 MHz band.

LightSquared’s terrestrial network is specified transmit at 1500W, which translates to roughly a billion times stronger signal than GPS signals at the surface of the Earth. Such powerful terrestrial signals have never been allowed in the satellite spectrum and are an important reason why GPS manufactures did not implement filters for illegal signals.




RE: LightSquared background
By mcnabney on 12/12/2011 8:25:35 PM , Rating: 2
What is more important is that Sprint is basing their hopes for deploying an LTE network on this company.

Now that this has doomed Lightsquared, so too are Sprint's LTE hopes. And guess what. Sprint is going to have a hard time competing without LTE and with Wimax which has already been announced as end-of-life. Add in the massive iPhone purchase agreement and Sprint is dead. How can Sprint ever hope to sell an LTE iPhone5 this summer when the only data connection it will have will be EVDO? Stick a fork in Sprint. They are done.

/They really should have known better. They had to write-off about $30B in Nextel investment due to ongoing issues adapting iDEN (which runs on CB radio spectrum!)


RE: LightSquared background
By Just Tom on 12/19/2011 8:38:46 PM , Rating: 2
CB runs at 27 MHz in the US. Nextel's iDen network at 800-900 MHz. It is hard to trust the rest of your analyses when you are so far off on this.


"When an individual makes a copy of a song for himself, I suppose we can say he stole a song." -- Sony BMG attorney Jennifer Pariser














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki