08.03.2006 12:00 AM
NAB Supports Spectrum Sharing Tests, But Not in TV Spectrum
NAB and MSTV have told
the FCC that while they support the creation of a spectrum sharing innovation test bed, the commission should avoid any testing in broadcast TV spectrum, except in rural areas where channels could be found that were not co-channel, first or second adjacent; or on a UHF "taboo" channel to any existing full-power or low-power analog or digital TV station.
In responding to an FCC inquiry into testing spectrum sharing, (FCC Docket 06-89), the associations supported comments filed by Shure (which was concerned about interference to wireless microphones and intercom equipment), Shared Spectrum and the ARRL (representing amateur radio operators). The companies told the commission that the test bed could be used for a comprehensive evaluation of "smart" technology prior
to allowing widespread introduction of this technology into licensed band, federal or non-federal. NAB and MSTV agreed with comments from Motorola arguing, "It would be premature to rely on spectrum sensing until these mechanisms are shown to be reliable via comprehensive study and real-world testing."
In its opposition to sharing tests in the TV broadcast band, NAB notes that the open architecture of TV receivers "allows for literally thousands of variants among the receiving equipment (i.e. TV sets and Part 74 devices) used in the broadcast spectrum." NAB contends that unlicensed devices on TV bands must not only detect full power broadcasts, but LPTV broadcasts and licensed broadcast auxiliary services such as wireless microphones that use the TV bands. NAB and MSTV argued that the test bed, in addition to evaluating spectrum-sharing technologies, could also be used to test other new and unique uses of the spectrum, such as distributed transmission systems. While DTS offers an opportunity to improve DTV reception, there have been concerns raised about possible interference to other broadcasters.