FCC Says Go on HD Throttle-Up

February 3, 2010

The FCC's Mass Media Bureau has adopted a long anticipated order allowing nearly all FM IBOC digital broadcast licensees to voluntarily increase their digital carrier power by at least 6dB, with a new application path for eligible stations to make a whopping 10dB boost. The order also establishes a regulatory process for remediation of "bona fide" interference disputes within 90 days of filings with the Commission, imposes increase limits on grandfathered "super-powered" stations, and reserves the right to revisit the issue if "significant" interference occurs.

Announcement of the order on Jan. 29 was undoubtedly a high-five moment for members of the HD Radio Alliance and staffers at HD Radio developer Ibiquity Digital. Both groups have been lobbying the Commission to move forward with a 10-fold across-the-board increase. Transmitter manufacturers, suffering an industry-wide economic downturn, are smiling as well, since a number of transmission plants already running FM HD will require substantial upgrades in order to satisfy the demands of -10dBc operation.

Reaction to the news release among the FM broadcast community was predictably mixed, given the highly polarized debate the issue stirred over the past year; radio engineering message boards have been buzzing with speculation regarding the order's impact. But unlike the one-page news release issued on Jan. 27 summarizing it, the order text gives considerable insight not only to specific details, but also to the Media Bureau's mindset in terms of its decision making.

High points of the document include:

  • With almost no exception, FM stations operating with IBOC digital hybrid signals will be able to increase their digital carrier power to -14dBc , requiring only an electronic notification to the FCC as they boost the signal. Stations increasing to -14dBc will not have to take potential interference to LPFM stations into account.
  • So-called super-powered stations will have unique limits imposed on their digital carrier increase depending on actual ERP and antenna heights above and beyond the nominal station class, so the FCC has provided an online calculator to generate those values. Once such a station has determined its permissible increase level, it must provide that information in an informal request filed with the FCC prior to the boost.
  • Any station wishing to increase their IBOC digital carrier above -14dBc to a maximum of -10dBc must submit an informal application that includes an analysis specifically addressing protection of analog signals within the 60dBu protected contour of first-adjacent channel stations. The order includes a table and procedures for making the analysis, which is based on NPR's Report to the FCC on the Advanced IBOC Coverage and Compatibility Study ("AICCS Project Report") filed with the Commission in November 2009. Application of the published calculation yields the maximum permissible digital carrier level in dBc.
  • In any case where verifiable listener complaints occur regarding interference to an analog signal within a station's protected contour, the station receiving interference is required to contact the station responsible for the interference to seek voluntary resolution. In the event the stations involved fail to reach a resolution, the station receiving interference may file a complaint with the Commission, but the complaint must provide six verifiable reports of ongoing interference and a map of the locations where the interference is occurring, along with a description of tests and equipment used to determine the source of interference. nIn such "bona fide" cases, the order states the FCC will require tiered reduction of the interfering digital signal as necessary to remediate the interference within 90 days of filing.
  • No additional protections are afforded to LPFM services, which retain their secondary class status, and must accept any additional interference.

    With the exception of the interference protection and complaint remediation section (which seem to be provoking a lot of discussion on boards and forums), the new rules seem relatively straightforward. Since they take effect 30 days after publication in the Federal Register, wholesale throttle up is likely to begin in mid March, while stations in a hurry can still file for an STA to cover them till that time.

    Reaction in radio's blogosphere almost a week after the Commission's pronouncement seems mixed. Those who have been proponents of HD Radio are convinced that this step will finally secure FM HD's future. Those who have questioned the potential damage to fragile analog FM coverage see trouble ahead. Others say mobile broadband media devices may soon render the point moot, as their sales numbers far outstrip those of HD Radio devices.

    Whether this latest action by the Commission will ultimately succeed in getting the now-anemic pace of FM HD station conversions moving again is yet to be seen. What's unlikely to change, at least in the short term, is the controversy over its unintended consequences for analog FM listening across the nation.

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