On Tuesday, the FCC approved LightSquared’s fallback plan to move from a frequency close to that of GPS in the upper L-band–where tests had shown severe interference–to a lower 10-MHz portion of the same spectrum where reduced interference was expected.
Possibly recognizing that the July 1 final report on GPS testing showed that interference was worse than predicted, LightSquared lawyers are now bypassing the FCC and submitting technical papers directly to the UN’s International Telecommunications Union (ITU) in Geneva, according to published reports.
Following extensive reports of GPS interference, LightSquared announced last week that it would vacate its L-Band frequency adjacent to GPS and move to one further away to greatly reduce, but not eliminate, interference with satnav signals.
“The test data discussed today makes clear that there is substantial interference to GPS if LightSquared turns on high-powered terrestrial facilities in the spectrum next door to GPS,” Trimble vice president and general counsel Jim Kirkland said today at an event sponsored by the National Space-Based PNT Advisory Board. Kirkland is also a founding member of the Coalition to Save Our GPS.
LightSquared documents submitted to the FCC last week reveal that its transmitters were transmitting at only half power during the tests recently conducted in the Las Vegas area to check for interference with GPS receivers. This means that any interference detected by the GPS units could be as much as half that expected when the LightSquared transmitters operate at their eventual planned power levels.
The confrontation between LightSquared and the U.S. government and industry GPS interests is heating up. LightSquared was able to obtain an FCC waiver of its satellite broadcast license to build a supplemental terrestrial transmitter network for broadband wireless. The GPS community claims that LightSquared’s plan, using a radio frequency close to that of GPS, will create interference. On Friday, Rep.
Following a certification and verification process, the European Commission approved the European Geostationary Navigation Overlay Service (Egnos) “safety-of-life” service for aviation last month. Egnos is closely similar to, and compatible with, the U.S. Waas satellite-based augmentation system that corrects timing errors in GPS signals, enabling GPS precision approaches and shorter, more-direct routes.
Representatives from a wide variety of industries, companies and associations, including AOPA and GAMA, have joined together to form the Coalition To Save Our GPS to resolve a “serious threat” to GPS.
At press time, the first of three monthly reports of the technical arguments between experts from LightSquared and the GPS community over GPS jamming was about to be issued.