Digital and HD Radio Revolution
DAB makes analog AM and FM outmoded systems. With the great popularity of home and portable digital music equipment (CD, MP3s, iPods), broadcasters are forced to convert their signals to remain competitive. Thus, DAB, or High Definition (HD) as it is more popularly called, looms large in the future of radio. The days of analog signal propagation are numbered. (For an explanation of both digital and analog signaling, see Chapters 9 and 10.) In the mid-1980s, compact disc players were introduced to the consumer market. Today, CD players no longer rank as the top consumer item for home music reproduction, because they have all but been replaced by iPods and MP3s. Turntables have long gone by the board, and the analog tape cassette market is consigned to the history books. Digital is here to stay, at least until something better comes along.
At first broadcasters viewed DAB as a threat. The National Association of Broadcasters (NAB) looked at the new sound technology adversarially. In an interview in the July 23, 1990, issue of RadioWeek, John Abel, NAB’s executive vice president of operations, stated, “DAB is a threat and anyone who plans to stay in business for a while needs to pay careful attention.” As time went on, DAB was regarded as a fait accompli, something that was simply going to happen. Soon broadcasters assumed a more proactive posture regarding the technology, and then the concern shifted to where to put the new medium and how to protect existing broadcast operations. Early on, NAB proposed locating DAB in the L-band portion of the electromagnetic spectrum. It also argued for in-band placement. Eventually the FCC saw fit to recommend that DAB be allocated room in the S-band, and it took its proposal to the World Administrative Radio Conference (WARC) held in Spain in February 1992.
This spectrum designation is expected to help in-band terrestrial development. In-band, on-channel (IBOC) digital signaling, developed by iBiquity Digital Corporation’s Glynn Walden, permits broadcasters to remain on their existing frequencies. This is something they favor, as satellite DAB signal transmission is regarded as a significant threat to the local nature of U.S. broadcasting. On the other hand, many countries are fully supportive of a satellite DAB system because they do not have the number of stations the United States possesses and thus lack the coverage and financial investment. Of course, digitized terrestrial radio (called HD Radio) renders existing analog receivers obsolete. This is cause for some anxiety among broadcasters who wonder how quickly the buying public will convert. However, considerable confidence exists since consumers’ huge appetitite for new and improved sound shows no sign of abating. As of this writing, several manufacturers are offering HD receivers at prices that are becoming more and more affordable and competitive and a number of car manufacturers provide HD Radio in their latest models. Digital converters are also available at a modest price.
Considered another plus of digital radio is its capacity to do other things. For example, iBiquity has developed a technology that allows those stations broadcasting digitally to transmit data to portable digital services, including cell phones. This is attractive to the station operator’s bottom line. The ability to multicast (provide side-channel transmissions) is yet another major plus for HD Radio. Known as HD2, it allows the medium to provide additional program streams (two to eight channels) to the listening audience. America is a nation of audiophiles, demanding high-quality sound. Analog broadcasting cannot compete with the interference-free reception and greater frequency dynamics of digital signals. Digital signaling heralds a new age in radio broadcasting. Jeff Tellis, former president of the IBS, explains why. “The reason for the great interest in digital broadcasting is its considerable number of advantages.” Among them are:
• Significantly improved coverage using significantly less power
• Dramatic improvement in the quality of the signal; compare CD to vinyl
• More precise coverage control using multiple transmitters similar to cellular phone technology
• No adjacent channel reception problems
• On-channel booster capabilities eliminating the need to use separate frequencies to extend the same signal • Easy transmission of auxiliary services, including format information, traffic, weather, text, and selective messaging services
• Sharing of transmitting facilities – common transmitter and antenna
Telecommunications professor Ernest Hakanen expands on the cost advantages of digital broadcasting. “DAB also promises to be economically efficient. Since there is no interstation interference between digital signals and because of the appeal of the spectrum efficiency provided by the interleaved environment, all of the channel operators in an area could utilize the same transmitter. The transmission facilities could be operated by a consortium for the construction, operation, and maintenance of the common transmission plant. Antenna height for DAB systems is also lower than current FM standards. Electrical power conservation and savings are a huge advantage of DAB.”
Picking up on Hakanen’s point about consolidating broadcast operations, Lynn Christian says, “The consortium (radio station malls or clusters) approach to maintaining and operating a station is commonplace because of economic reasons, and HD Radio is very conducive to a collaborative relationship among broadcasters.” Prior to the WARC meeting in 1992, NAB’s DAB Task Force proposed a set of standards to ensure that the technology would operate effectively. The specifications included:
• CD-quality sound
• Enhanced coverage area
• Accommodation of existing AM and FM frequencies
• Immunity to multipath interference
• Immunity to stoplight fades
• No interference to existing AM and FM broadcasters
• DAB system interference immunity
• Minimization of transmission costs
• Receiver complexity
• Additional data capacity
• Reception area threshold
After nearly a century of analog signal transmission, radio is venturing into the digital domain, which will keep it relevant to the demands of a technologically sophisticated listening marketplace as it embarks on its next 100 years. As of this writing hundreds of radio stations across the country offer digital signals, and the majority are also providing expanded listening options with HD2 service. At several industry gatherings in the first half of the 2000s, former NAB president Eddie Fritts presciently proclaimed HD Radio as the wave of the medium’s future, saying “Transitioning to digital will give radio even better opportunities to serve [its] listeners.” Today, not all industry observers see HD/ HD2 as the solution to the drop in music radio listening. Observes Mark Ramsey of Mercury Media Research, “Will digital help reverse radio’s declining audience? Absolutely not.” Counters Dave Neugesser, “It’s not something that’s going to happen overnight. HD2 gives radio an infinite dial with incalculable choices, but it won’t impact the market as fast as some would like. Before this happens, it has to be standard equipment in new cars, and people have to buy HD radios. It’s a steep hill, but it can be surmounted.”