FCC Seeks Comments on FM IBOC Power Increase

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FCC Seeks Comments on FM IBOC Power Increase

Oct 23, 2008 4:23 PM

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Washington, DC - Oct 23, 2008 - The FCC is seeking public comment on several recent filings in the pending digital audio broadcasting proceeding, MM Docket No. 99-325. A group consisting of 18 broadcasters that operate more than 1,200 commercial and noncommercial educational FM radio stations and the four largest manufacturers of broadcast transmission equipment has filed a request asking the Commission to revise the current technical specifications for FM digital audio broadcasting. Specifically, the group requests the Commission to increase the maximum permissible digital operating power of FM stations from the current level of 1 percent of a station's authorized analog power (-20dB) to a maximum of 10 percent of a station's authorized analog power (-10dB).

Filed concurrently with and in support of the request was a technical report prepared by Ibiquity Digital, which examined the benefits to digital broadcasting, the compatibility with analog broadcasting, and the potential interference effects resulting from the proposed increase in permissible FM digital operating power. Based on the Ibiquity study, the filers requested that the Commission authorize voluntary increased digital operation power for FM stations up to a maximum value of 10 percent of the station's authorized analog power.

In addition, National Public Radio has submitted its recently completed Corporation for Public Broadcasting-supported research on digital radio coverage and interference. As part of this study, NPR investigated the effect of an increase in digital operating power to 10 percent of authorized analog power, and concluded that such an increase in digital operating power for FM stations could result in interference to reception of first and second adjacent channel FM stations, and that further testing is necessary to determine if increased digital operating power can be permitted for FM stations.

The FCC has posted the request and the Ibiquity and NPR technical studies online. are available electronically through the FCC's Electronic Comment Filing System (http://fjallfoss.fcc.gov//prod/ecfs/comsrch_v2.cgi) under MM Docket No. 99-325.

This digital sideband increase has been the subject of many debates, and now it moves to the public record for a decision. Given the prominence of the filing group, the proposal has a high likelihood of being adopted, although the NPR study could be the basis of some persuasive opposition.

MM Docket No. 99-325
Comment Date: Nov. 28, 2008
Reply Comment Date: Jan. 4, 2009