AT&T told NTIA it believed mitigation measures could be implement...

prevent or reduce interference in this band related to unlicensed devices. The FCC opened an inquiry in 2002 on making additional spectrum available for unlicensed devices. The inquiry covered the feasibility of allowing unlicensed devices in bands such as 3650-3700 MHz at power levels higher than other unlicensed transmitters with certain technical requirements to prevent interference. NTIA said there appeared to be benefits in allowing higher power usage at 3650-3700 MHz for rural markets, but said that approach would likely have limited success in urban markets “due to the lack of supportable competition due to interference given the typical channel width of 20 MHz.” AT&T said it backed the proposed opening of spectrum for use by unlicensed devices, “provided that means are established to prevent harmful interference to AT&T’s C-band satellite earth stations.” AT&T said it operated some satellite earth stations in the “extended C-band” at 3650-3700 MHz. “Unless appropriate measures are employed, operation of unlicensed devices in the extended C-band could directly interfere with these earth stations, which are very sensitive to interference,” AT&T told NTIA in a filing. Because the earth stations are generally in remote locations, AT&T said mitigation measures such as power limits and frequency hopping could be used to allow unlicensed devices in this band while protecting earth stations. In a separate filing last week, the Satellite Industry Assn. (SIA) raised concerns about the fixed satellite services (FSS) in the band and adjacent bands that could be affected by unlicensed devices in this spectrum. SIA Pres. Richard Dalbello said in 2000 the use of these frequencies was grandfathered for certain pre-existing FSS earth stations by way of restricting terrestrial mobile services to base station operations. “Several SIA members are currently authorized to provide FSS services in these frequencies and are particularly concerned with the potential impact on services due to the aggregate power to be radiated by these unlicensed devices, given that the total number of devices is not known,” he said. He stressed the importance of ensuring that out-of-band emissions from such unlicensed devices were low enough to guarantee there won’t be interference into FSS systems operating in adjacent spectrum. SIA asked that NTIA consider the impact on commercial operations while researching the potential impact of unlicensed devices on govt. services in this spectrum “given that commercial operators may currently, or in the future, utilize these frequencies to provide services to the U.S. govt.”