LightSquared report due amid criticism

The carrier will report on interference to GPS from its planned LTE network

Mobile startup LightSquared may go from the frying pan to the fire on Wednesday when it releases a report on potential interference between its planned network and GPS.

Reports on recent tests have shown the company's LTE (Long-Term Evolution) equipment knocked out Global Positioning System gear used for aviation, surveying, consumer navigation and other applications. The U.S. Defense Department and Transportation Department have also criticized LightSquared's plan. LightSquared will need to persuade the Federal Communications Commission (FCC) that the interference can be prevented before the agency will allow the project to continue.

On Wednesday, the carrier is due to issue a report from a Technical Working Group it formed with vendors and other interested parties in the GPS community. The group was formed to devise tests to determine interference.

LightSquared gained access to valuable terrestrial cellular spectrum by agreeing to combine an LTE network with a satellite system, which the FCC sees as a tool to improve mobile data access in rural areas of the U.S. The carrier plans to sell its cellular and satellite services wholesale to service providers who can offer subscribers either or both services. It won't offer any service plans of its own. Electronics retailer Best Buy and cellular carrier Leap Wireless have announced plans to resell LightSquared service.

However, part of the cellular spectrum LightSquared holds is next to frequencies used by GPS, the service that allows vehicles, airplanes, cell phones and other systems to determine their location via satellite signal. Conditions of the FCC's approval of LightSquared's network require the company to show GPS service would not be hurt. Over the past few months, LightSquared and its Technical Working Group have been devising and carrying out tests leading up to Wednesday's report.

Some test results disclosed at a meeting in Washington, D.C., on June 9 indicate the LTE network might put aviation, public safety and other valued uses of GPS at risk.

A series of tests in April had serious effects on several types of GPS systems, according to the National Positioning Navigation and Timing (PNT) Systems Engineering Forum. The Forum conducts assessments for the Space-Based PNT Executive Committee, a government agency set up to coordinate efforts around GPS and similar systems.

Tests in an anechoic chamber at White Sands Missile Range in New Mexico showed a simulated LightSquared network knocked out GPS receivers used for aviation, surveying, agriculture, the U.S. Coast Guard and Garmin personal navigation devices. All the aviation units lost their GPS connections, as did all the tested high-precision receivers for scientific use by NASA.

The PNT agency also reported the results of "live sky" tests conducted using a production transmitter set up and operated by LightSquared at Holloman Air Force Base in New Mexico. Among other things, those tests showed that police cars lost their GPS reception within about 600 feet from the tower and ambulances and fire trucks lost service about 1,000 feet away. General Motors' OnStar vehicle navigation systems also were significantly degraded, the agency said.

To mitigate the interference, the PNT group proposed shifting LightSquared service to other frequencies or adding filters to GPS receivers, a solution that the agency noted would be expensive and might affect GPS performance. Other possible solutions were changing LightSquared's antenna patterns and cutting transmitter power.

The RTCA, a non-profit corporation that advises the Federal Aviation Administration, said its tests showed that LightSquared's operations in one part of its spectrum band would make GPS unavailable to aircraft over a large region of the Northeastern U.S. RTCA recommended LightSquared not be able to use that band, and called for further study.

At the June 9 meeting, LightSquared said there were several possible ways to mitigate the interference, including ones involving the frequencies and transmitting power the carrier uses, and that it had not taken any options for mitigation off the table.

Stephen Lawson covers mobile, storage and networking technologies for The IDG News Service. Follow Stephen on Twitter at @sdlawsonmedia. Stephen's e-mail address is stephen_lawson@idg.com

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection

Tags telecommunicationconsumer electronicsregulationLightSquaredGPSmobilegovernment

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Stephen Lawson

IDG News Service
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

George Khoury

Sharp PN-40TC1 Huddle Board

The biggest perks for me would be that it comes with easy to use and comprehensive programs that make the collaboration process a whole lot more intuitive and organic

David Coyle

Brother PocketJet PJ-773 A4 Portable Thermal Printer

I rate the printer as a 5 out of 5 stars as it has been able to fit seamlessly into my busy and mobile lifestyle.

Kurt Hegetschweiler

Brother PocketJet PJ-773 A4 Portable Thermal Printer

It’s perfect for mobile workers. Just take it out — it’s small enough to sit anywhere — turn it on, load a sheet of paper, and start printing.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?