A new report prepared by the National Space-Based Positioning, Navigation and Timing Systems Engineering Forum concludes that the planned deployment of a satellite and terrestrially based national broadband service by LightSquared “poses a significant potential for harmful interference” to Global Positioning System (GPS) services.
The report, “Assessment of LightSquared Terrestrial Broadband System Effects on GPS Receivers and GPS-Dependent Applications,” was submitted to FCC Chairman Julius Genachowski July 6 by the Commerce Department’s National Telecommunications and Information Administration.
It recommends LightSquared should not begin service as planned for terrestrial operation in the 1525MHz to 1559MHz Mobile-Satellite Service (MSS) band due to harmful interference to GPS operations. According to the report, tests have shown there to be “significant detrimental impacts to all GPS application” looked at for the report.
The report also calls on the government to conduct more thorough studies on “the operational, economic and safety impacts” of operating the company’s network. These studies should look at the compatibility of ATC (Ancillary Terrestrial Components) architectures in the MSS L Band with GPS applications.
Various approaches to mitigating harmful interference for LightSquared’s nationwide broadband service were considered. According to the report, two involving frequency separation were the most promising for GPS users. Relocation of LightSquared’s terrestrial operations to another band offered “the greatest long-term benefit to the GPS community,” the report said.
Limiting LightSquared transmissions to the lower 5MHz or 10 MHz channel of its planned deployment would offer protection for a limited number of GPS applications, but “other applications would still be susceptible to interference,” it said.
The day after the report was submitted to the FCC, LightSquared announced a new initiative to bring wireless broadband to rural America and the establishment of an advisory board, including former U.S. Senator Byron Dorgan (ND) and former Reps. George Nethercutt (WA) and Charlie Stenholm (TX).
A press statement announcing the moves quotes Nethercutt as saying giving farmers “accurate GPS signals and advanced wireless and broadband services … shouldn’t be mutually exclusive.”