Physics problem or engineering challenge? Wireless networking company LightSquared argues that, with some technical engineering work, its $14-billion plan to expand wireless broad-band to millions of consumers can work without disrupting the majority of the industry's global positioning systems.
But on Sept. 8, during a hearing in the House, major U.S. government agencies that rely on GPS disagreed, calling the company's plan a major physics problem that essentially would create too much signal noise in spectrum bands adjacent to sensitive GPS networks, causing widespread disruption.
For example, the U.S. Geological Survey's David Applegate told the House Committee on Science, Space and Technology that tests of LightSquared's network plans would disrupt GPS systems that collect seismic monitoring data from earthquakes. The National Oceanic and Atmospheric Administration's Mary Glackin said at least five of its systems would be affected by LightSquared's network plan, including GPS that it uses for weather and space-storm monitoring. Anthony Russo, who directs the Coordination Office for Space-Based Positioning, Navigation and Timing, saidthe LightSquared networkplans would disrupt more thana billion satellite systems usersworldwide and urged that the company's plans not be licensed until all the technical issuesare resolved.
Facing stiff opposition to its network by other major U.S. agencies—including NASA, the Dept. of Transportation and the Dept. of Defense—LightSquared, Reston, Va., has floated a new network plan to the Federal Communications Commission, which is mulling over approval of LightSquared's network proposal. Filed with the FCC before the House hearing on Sept. 8, the proposal calls for more testing with lower transmission power using its ground-based towersas well as use of filtering technology to quell disruptionof other GPS bands.
LightSquared's chief counsel, Jeff Carlisle, says the company won't implement any plan that disrupts existing systems.
"This is not a zero-sum game between a GPS and a competitive broadband network,"he countered at the hearing."This is an issue of responsible receiver design."
