Sunday, December 11, 2011

LightSquared and GPS interference.

LightSquared is a company that plans to provide a wholesale, nationwide 4G-LTE wireless broadband network that includes satellite coverage. LightSquared plans to combine existing mobile satellite communications services with a ground-based wireless communications network that uses the same L-band radio spectrum as the satellites.

However the signals for the LightSquared base stations will be transmitted on a frequency immediately adjacent to those used for the existing Global Positioning System (GPS). A draft report suggested that 75% of GPS receivers would be affected by harmful interference when located 100 meters from a LightSquared base station. LightSquared are naturally upset that the draft report had been leaked and have stated that they plan to operate their equipment at lower power levels which would affect 10% of devices.

If I were certain of their intent to run lower power levels I would still find this to be an unacceptable situation. I'm positively sure that if the amateur radio community proposed to operate in a manner that caused harmful interference to 10% of GPS units we'd be shutdown so fast our heads would spin.

GPS receivers, while not falling under the same category as emergency radio systems, are none-the-less an essential service for the smooth running of society. GPS has integrated itself into almost every portable electronic device and are used for much more than just navigation. Allowing LightSquared to continue without serious real world testing would be the worst way to find out how essential GPS had become and just how much it would cost to have it disrupted. More details are available on the website of the National Executive Committee on Space-Based Positioning Navigation and Timing