Tomorrow Radio
Commercial broadcasters see digital radio's sound quality and PAD features as a way to compete with satellite radio. NPR saw something different: a possible application of HD Radio technology that solves one of public radio's more pressing problems. Public broadcasting, collectively, embodies several different formats: classical music, jazz, world music, Americana, news, talk, entertainment programming and more. Each genre has its own loyal audience, in some cases with little overlap.

When your local public station switches from "Morning Edition" to "Midday Classics," for example, the news audience tunes out and the classical music audience tunes in. Stations struggle to serve a diverse audience with a single signal that at best represents programming compromises their audiences are willing to put up with. Towards that end, the Tomorrow Radio Project explored the possibility of subdividing IBOC's 96kbps digital signal into two or more viable audio streams, giving stations the opportunity to broadcast different formats simultaneously.

The project was undertaken with some important partners. Kenwood USA, one of the nation?s largest manufacturers of audio gear, developed the HD Radio receivers used to test Tomorrow Radio. Kenwood is bringing HD Radio receivers to the marketplace in 2004. The Harris Corporation, a major supplier of broadcast equipment, created transmission equipment capable of splitting the digital signal that was used for the tests.

The promise of no compromise
According to Mike Starling, NPR's vice president of engineering and operations, nine of the top twenty-five radio markets only have one NPR affiliate station. Most smaller markets are served by a single public radio station. These stations have the difficult task of deciding what combination of formats they'll carry — knowing that each format only serves a fraction of their total potential audience. In some cases, there are simply not enough broadcast hours to adequately provide all the kinds of programming listeners desire. Since a significant part of a public radio station?s funding comes from listener contributions, reaching that under- or unserved potential audience is a major problem stations are desperate to address.

At CES, Tomorrow Radio successfully demonstrated that stations could broadcast two discrete streams of programming, both with sound quality that matches or exceeds current FM broadcasts. Each stream has its own PAD (or text information) — now an expected part of any digital radio broadcast. According to Starling, the 96kbps signal can be further subdivided, and as compression technology continues to improve, this capability will enable stations to provide even more program options.