The consortium of major broadcasters pushing digital radio are wasting no time deploying what they believe to be its “killer app,” multicasting – the ability to split a single radio channel into multiple program streams. Earlier this month they announced the rollout of digital multicast signals in several dozen markets. The broadcasts introduce industry-coordinated secondary program channels featuring formats like “Classical Alternative,” “Coffee House,” “Female Talk,” and “Extreme Hip-Hop,” and some miscellaneous strangeness. For now, these channels will be offered without commercials.
The languishing state of digital audio broadcasting in the United States following its introduction more than two years ago has spurred the nation’s largest broadcast conglomerates to form an “HD Digital Radio Alliance” to facilitate the bona-fide rollout of digital service. Key to this campaign is the coming of what the Alliance calls “HD2 multicast sidechannels.”
The ability to broadcast multiple program streams on a single radio channel is relatively new to the U.S. digital radio environment. As initially developed over the last 15 years (!) the dominant U.S. digital radio protocol, now known as “HD Radio,” did not accommodate a multicasting feature: National Public Radio spearheaded its creation less than three years ago.
Ibiquity Digital Corp., patent-holders on the In-Band On-Channel (IBOC) digital audio broadcast standard adopted by the U.S., announced its license fee structure earlier this month. Ibiquity’s technology is proprietary – therefore, going forward, digital radio broadcasting requires two licenses to broadcast: one from the government and one from Ibiquity.
In hopes of enticing early adoption, the initial “one-time” general IBOC license fee to Ibiquity begins at $5,000 per station. If stations wait just three years to convert, however, they will find that fee to be five-fold.
Then, there are the residuals: stations that multicast (i.e. carry multiple program streams on one channel) must pay Ibiquity 3% of the revenues derived from the second DAB channel, or $1,000, whichever is greater. This fee will be assessed annually. This is somewhat ironic because National Public Radio led the effort to develop IBOC-compliant multicast capability (something commercial broadcasters initially rebuffed).
Digital radio is essentially streaming audio over the air. Anyone who’s handled an audio file knows the rule of thumb: the better the bitrate, the better the sound. In the file-sharing community most songs are offered is 128kbps – okay, not CD quality, but not cruddy like a tape dub. Some audio encoders offer better quality than others, due to subtle differences in the encoding algorithm each system uses.
For “HD Radio,” the U.S. brand name for digital radio, the bitrate for most stations is expected to be between 64-96kbps, with AM running as low as 36kbps. iBiquity, the company behind the system, promises “enhanced sound fidelity” at these bitrates. In May the National Radio Systems Committee disagreed, suspending the official standard-setting process for the IBOC technology (at the heart of “HD Radio”) after declaring its audio quality unsuitable for broadcast, jeopardizing the full-scale rollout of consumer receivers for that all-important holiday season in the process.
Guess what? The sound quality of the new “HD Radio” system sucks! That’s the verdict of none other than the National Radio Systems Committee, the industry-sponsored group that develops radio broadcast standards in the U.S.
In an internal memo dated May 14 (.pdf, 94K), Milford Smith, chairman of the NRSC subcommittee on digital radio, announced it is “temporarily suspending its IBOC-DAB standards-setting process.” This is due in part to the results of recent on-air tests and a private demonstration held at the Washington, D.C. studios of National Public Radio. The evidence mostly involves the AM side of the iBiquity-engineered digital radio system.