NPR TESTING NEW CODECS FOR IBOC DIGITAL RADIO

The tests will focus on how much bandwidth is required to provide improved digital audio reading services, Starling said. The preliminary results of the Corp. for Public Bcstg.-funded research on developing the “extended hybrid capabilities” of iBiquity’s in-band, on-channel (IBOC) technology will be presented to the FCC early next month, he said.

NPR has asked the Commission to hold off setting new regulatory requirements for digital transmission of radio reading services until the tests are done. That shouldn’t require delaying FCC action on DAB and digital multicasting, Starling said. NPR hopes its tests will “better inform” the Commission of the “logical underpinnings of how well additional supplemental audio channels can work with the iBiquity system.”

Starling said the NPR tests seek to: (1) Determine what bit rates are most appropriate for public radio formats for jazz, classical and news talk. For this, NPR will conduct panels of “subjective” audio listeners because there’s no audio quality meter to measure “what works best in what situation.” (2) Find out whether one or 2 extended hybrids are needed for improved digital radio reading service and detect any interference. Lighting up extended hybrids to extend bandwidth could increase “hiss” on inexpensive radios, he said.

Starling said he expected Commission action on supplemental audio channel, since the agency has teed up the issue. NPR, which pioneered the secondary audio channel, was “gratified” that 40 state broadcast associations, companies like Microsoft, Cox and Clear Channel and the NAB itself supported multicasting with the IBOC system, he said: “So we are cautiously optimistic that based on earlier expression of interest at the Commission, they will indeed go ahead and endorse this as an authorized activity since there is no interference impact from doing it within the main audio program.” Although commercial broadcasters have shown much interest in multicasting, there have been no direct inquiries to NPR, he said: “But that’s probably not necessary because we have been very transparent about sharing all the results of the Tomorrow Radio project.” The results have been made available to the National Radio Systems Committee (NRSC), where all radio groups are represented, he said.

Getting radio reading service-enabled receivers is a “big part” of NPR’s upcoming tests, Starling said, “to determine if we can use the exact same codec that comes with the [IBOC] system or if it makes sense for this special purpose application to use a different codec and to try and get that integrated into the chipset.” Chipmakers, he said, had indicated there was sufficient space for it and “they could do it if there is one clear winner. So we are testing a variety of codecs this summer to see which ones perform best and we should know some results hopefully around Labor Day.”

While urging the Commission to immediately allow stations to start multicasting without special licensing, NPR has sought authorization for public radio stations to use digital broadcasting to offer “remunerative” services without having to pay spectrum fees. Public TV got FCC permission to provide ad- supported nonbroadcast ancillary and supplementary services to augment station revenue. But public TV stations were asked to ensure a “substantial majority” of their digital capacity was used for nonprofit, noncommercial educational service. NPR doesn’t want any such restrictions on use of digital capacity. Vp-Govt. Relations Mike Riksen said as a “engineering and technology proposition, we have less bits in our bitstream than TV. So requiring some level of delivery to satisfy a primary broadcast stream, we think is just not appropriate, especially given the… improvements in compression technology.” While public broadcasters appreciated that the FCC wanted delivery of “fine quality audio,” the agency didn’t have to worry about that with public radio, he said.

Asked whether public radio is thinking of ad-supported supplementary audio services, he said services hadn’t been thought out in detail. “We simply want to reserve the right we currently have to use sub-carriers for remunerative purposes, and we simply want that basic notion or concept to be preserved for future use in a digital broadcast environment.” Starling said public radio’s interest in digital conversion was predicated on multicasting possibilities. He said virtually no station wanted to make the conversion just to keep pace with commercial counterparts or give listeners “somewhat improved audio enhancement… I think without exception everyone has said that the beef for public radio is in their ability to do multicasting and offer additional program services.” Judging by the pace of digital conversion fund intake from CPB, Starling said, he expected more than 200 public radio stations to be “well down the road to digital broadcasting” by year-end.