NPR Moves Multi-Channel Forward

Network Seeks Manufacturers to Make Radios; It Will Provide Program Streams for Members
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Network Seeks Manufacturers to Make Radios; It Will Provide Program Streams for Members

Network Seeks Manufacturers to Make Radios; It Will Provide Program Streams for Members

For some station executives, going digital only makes sense if there's an opportunity to create new programming to go along with the promise of better audio.

That's why this June, NPR plans to offer several program streams to member stations that plan to split their digital signals into multiple channels. By fall, the network hopes, receivers will be available to consumers to decode multi-channel digital radio.

Radio World has reported on the efforts of NPR and its partners Kenwood and Harris to test the concept of multi-channel digital. Now NPR is prepared to bring its Tomorrow Radio project to reality with plans for handling both the programming and hardware needs of member stations.

Anticipating a group purchase of receivers, the network is asking manufacturers to make HD Radios that can receive multiple digital signals. It is offering special, free, programming available to member stations to fill the channels with content.

The target date is June for the first of a planned four program streams consisting of classical, jazz, news/talk and another music channel. Format streams developed for the supplemental channels are seen as the ones most likely to grow and be supported by the network for a long time, sources close to NPR said.

Many in radio long have argued that digital only makes sense if the industry can deliver improved content as part of the transition, giving consumers sufficient reason to buy HD Radios - just as subscribers to satellite radio do so for the new content.

Mike Bergman, Kenwood vice president of new digital technologies, said Tomorrow Radio "is the single most important feature to promote HD Radio because it gives the consumer another compelling reason to buy" aside from great audio quality with digital radio.

Possible group buy

NPR released a Request for Information to licensed HD Radio receiver manufacturers at the recent CES convention in Las Vegas. Other HD Radio vendors were welcome to respond. A future group purchase could include 10,000 to 50,000 radios, said Mike Starling, NPR vice president of engineering and operations.

"It depends on what the manufacturers tell us about the price points, whether we can come to terms and actually execute a group buy. That's why it's an RFI as opposed to an RFP," or a Request for Proposal, he said.

NPR hopes to be able to craft a deal by the spring NAB show so it can place an order and have the units shipped in time for station fall fundraisers.

The radios would be used to seed the marketplace, probably as pledge premiums, and by station employees for station monitoring.

The RFI response deadline was Jan. 31. The network has brokered such group equipment buys in the past, he said.

Eventually, all stations would pay NPR for their radios, said John Kean, senior technologist at NPR.

While the multi-channel concept has garnered the most attention from the non-commercial world, commercial broadcasters are warming up to the potential of the supplemental digital channels. Several told Radio World they are looking at the concept.

At Ibiquity's press conference in Las Vegas, Entercom President/CEO David Field called the technology an "opportunity to create new radio stations to grow content."

Ibiquity Digital President/CEO Robert Struble said the extra channel capability of digital radio would "help these guys (representing different radio groups) light up a competitive battle" between each other and with satellite radio.

At the show, KCNV(FM) in Las Vegas became the 50th NPR member station to go HD Radio. It was featured in a supplemental audio demo at Ibiquity's booth.

Approximately 300 NPR member stations are in various stages of digital conversion, with funding for an additional 150 to 200 expected to be approved by the Corporation for Public Broadcasting this year, according to NPR executives.

How low can you go?

NPR hopes the FCC approves the multi-channel concept for HD Radio early this year.

In perceptual test results of Ibiquity's HDC codec at various bit rates, submitted to the commission in the fall, NPR said, "The new testing indicates that 48 kbps is perceived by most listeners as providing equal sound quality to the maximum rate of 96 kbps."

Optimum bit rate allocation varies according to format, so NPR hoped the agency would allow stations to determine their own bit rate allocation for multicasting.

The codec tests showed it was possible to achieve two near-CD quality channels, plus up to four additional voice-grade channels with minimal, if any, interference to existing analog radios, Starling said. Twelve codecs from nine vendors were tested.

In the initial tests last year, the main channel was 64 kbps and the supplemental channel was 32 kbps.

NPR referenced its "Report on Perceptual Tests of Low- and Very Low-Bit Rate Codecs," filed with the FCC - the results of testing that the network commissioned, along with the International Association of Audio Information Services and Ibiquity.

Participants wanted to see if the extended hybrid digital spectrum was suitable for radio reading service transmission. The testing measured subjective qualitative differences among the latest digital codecs that may be used for radio reading services.

The network stated, "Improved quality was achieved with readily available codecs compared to existing analog SCA technologies, both within a single extended hybrid partition and within two of the four available partitions. Based on these results, we believe radio reading services, and other specialized audience services, will be a practical service option via extended hybrid mode."

Reading services viable

"This would allow listeners who rely on these services to purchase commonly available mass-market receivers, ultimately freeing these services from reliance on specially manufactured SCA receivers, which historically have offered inferior quality service," it stated.

(For hybrid analog/digital broadcasting, the Ibiquity HD Radio system adds a number of OFDM carriers above and below the host analog signal. Groups of carriers are formed into frequency partitions about 6904 Hz each in width. Ten of the outer partitions form the main group, providing a 96 kbps digital stream for the primary audio channel [and optionally, supplemental audio]. Additional sets of partitions are allocated symmetrically within the pair of main partitions, called the extended hybrid mode. These interior partitions provide ancillary data streams at about 12.5 kbps each. Radio World will report further on these tests in a subsequent issue.)

Based on results in the tests, NPR asked the FCC for expedited authorization for public stations to begin digital multicasting to foster the development of diverse, new public programming services; eliminate the costs of retroactive upgrades; and afford stations the opportunity to streamline operations.

The network hopes the commission approves the multicasting initiative in the first half of the year.