LightSquared Proposes Broadband/GNSS Interference Testing Plan

LightSquared is asking for U.S. Transportation Department feedback on a plan for testing how terrestrial broadband and GPS might co-exist. In an FCC ex parte filing in docket 12-340 posted Wednesday, it said technology consulting firm Roberson and Associates gave the DOT some initial outlines on its testing approach. The testing involves spectrum used by global navigation satellite system (GNSS) spectrum and its proximity to spectrum used by LightSquared and Inmarsat, and how LTE bases or handsets can cause interference with nearby GPS receivers. The Roberson testing proposal will look at actual devices from such providers as Apple, Garmin, Magellan, Samsung, Topcon and Trimble, and measure the relationship of GPS error and signal-to-noise ratios. The Roberson presentation said the testing is to confirm that front-end filters on such GPS devices allow GNSS reception and still let the devices work properly. And in cases when GPS performance still sees interference from terrestrial LTE despite such front-end filters, possible fixes include use of different augmentation signals that improve GPS accuracy, or different front-end filters, LightSquared said.