But Still No Real-World Testing On G4 Network

The U.S. Air Force is raising concerns that a new G4 service to be offered by a company called LightSquared which was recently approved by the FCC will create so much interference that it could render GPS units worthless.

The commander of the U.S. Air Force Space Command General William Shelton has called the scenario in which all GPS signals would effectively be jammed within 3-5 miles of a LightSquared G4 tower "unbelievable," and says he hopes the FCC "does the right thing."

The tech blog Engaget reports that the testing conducted by Garmin used simulated interference filters, and not the actual filters LightSquared has reportedly spent millions to develop, and which a company spokesman says prevents the jamming.

DoD Buzz reports that the primary issue is that the GPS signal is weak when it arrives from orbit to the receiver. LightSquare's signal on an adjacent frequency would effective blanket the GPS, making it unavailable to those receivers. That could spell serious problems for NextGen as well as for military aircraft navigation.

The conditional FCC licence stipulates that LightSquared not jam other signals.

FMI: www.afspc.af.mil