Broadcasters and a major microphone manufacturer both praised the FCC's recently released study on possible DTV interference, which it conducted to help determine how to protect digital TV sets from interference.
But in comments to the commission, both the Shure company and the National Association of Broadcasters (with and assist from the Association of Maximum Service Television) asked for more testing and argued that one way to protect the DTV transition from interference would be not to allow mobile unlicensed devices to operate in the DTV band.
The FCC commissioners have said they were inclined to allow the devices to get more use out of the spectrum and promote wireless broadband, but they have also said that preventing interference, and potential impediments, to the DTV transition is also important.
According to Shure, among the FCC's findings after testing eight "late-model DTV receivers" was that the receivers are extremely vulnerable to harmful interference not only from devices on adjacent channels but from ones two or more channels away.
NAB pointed out that the FCC found that weak DTV signals were easily disrupted, and that that precludes the use of so-called spectrum "sensing " devices, which some commissioners have pointed to as a way to insure efficient spectrum use while protecting TV licensees.
The FCC has already begun the process of opening up the spaces--so-called white spaces--between TV station frequencies for advanced wireless services, but has not decided whether those should be licensed or unlicensed.
The bottom line for broadcasters and Shure is that the FCC must do more testing, expand those tests, and come up with rules that effectively protect existing devices, like TV sets and wireless microphones.