The FCC has approved the front-running technology for digital radio, known as IBOC, but it dismissed or delayed action on several concerns raised by pubcasters.
The unanimous decision Oct. 10 enables stations to start using IBOC, which simultaneously transmits digital and analog signals.
Unlike television, radio does not face a mandate to convert to digital by a certain date. IBOC, which stands for in-band, on-channel, works with both current receivers and the digital models expected to hit the market in January, allowing stations to air analog signals indefinitely.
FCC commissioners hailed the decision as a huge step forward for the medium as it faces growing competition from higher-fidelity technologies such as satellite radio. However, they endorsed digital AM for daytime only, citing continuing concerns about interference during nighttime broadcasts. iBiquity Digital Corp., IBOC’s solo proponent, plans to complete testing of nighttime AM transmission by year’s end.
Though the FCC okayed IBOC, it did not formally set a digital broadcasting standard. Further testing and real-world experience with IBOC will shape a formal standard-setting process in coming months, which will end with new licensing and service rules for digital radio.
Public radio organizations have tried to influence IBOC’s development by pressing a wish list of considerations on the FCC as it crept toward its landmark decision.
Groups including NPR, the National Federation of Community Broadcasters and the International Association of Audio Information Services asked the FCC to resolve a perennial problem of FM-TV interference by reallocating television Channel 6 (82–88 MHz) to digital radio. They suggested that the FCC protect radio reading services from interference. They also hoped the agency would urge receiver manufacturers to support secondary audio channels, which could allow stations to broadcast two or more services simultaneously on the same frequency.
The FCC declined to grant any of these wishes. It dismissed the request for Channel 6, noting that television might continue to use that spectrum beyond its digital conversion in 2006, and delayed taking up the other matters until it sets the formal standard.
That means pubcasters will have to keep waiting, and pushing, for a digital technology that meets their needs. Notably, they see great promise in IBOC secondary audio channels. A station could transmit both a high-quality music channel and a lower-fidelity news channel, for example.
But the secondary channels will catch on only if manufacturers support the capability in radios. “That’s ultimately what will make digital radio more attractive to consumers,” says NFCB President Carol Pierson.
The IAAIS hopes that secondary channels could provide a new distribution path for information services that now broadcast to special receivers on FM subcarrier frequencies.
The FCC acknowledged the potential of such technology but did not force it on the industry, opting instead to delay further consideration. Nonetheless, NPR applauded the FCC for even acknowledging the promise of secondary audio.
Pubcasters also voiced concerns about IBOC’s impact on radio reading services, which they carry on the edge of their analog FM signals. Adding digital signals increases energy in the FM band that overloads subcarrier receivers, says David Noble, chairman of government affairs for the IAAIS. A study conducted by NPR showed that IBOC could affect “2.6 percent of eligible receivers within an FM station’s service area,” according to the FCC.
That sounds low, Noble says, but “imagine public stations losing 2.6 percent of their audience nationally, or even per station—and it would be worse in some areas. How happy could you be about that?”
As with secondary audio services, the FCC said it will study the protection of reading services in a Further Notice of Proposed Rulemaking. Until then, it will settle interference problems on a case-by-case basis.