Digital Television

Digital Television (DTV) refers to the transmission of digital signals to a digital TV set for display. [Page 149]Similar to analog television signals, these digital signals can be broadcast over the air or sent through a cable or satellite system. With its brilliant, high-definition images, CD-quality audio, and the possibility of transmitting multiple programs and information simultaneously, the quality of digital television is a vast improvement over the analog television that most of us experience today.

With DTV, more visual information can be sent without increasing the broadcast frequency spectrum because the data is compressed, making the DTV picture noticeably clearer. Most analog television broadcast stations transmit a picture that contains 480 vertical interlaced lines with about 340 horizontal pixels per line, whereas DTV's pictures can be 1,080 vertical interlaced lines with 1,920 horizontal pixels per line.

DTV allows transmission of television programming in new wide-screen, high-definition television (HDTV) formats. HDTV sets take full advantage of the digital signal, and use the highest DTV image resolution combined with Dolby Digital surround sound. In addition to the higher-resolution picture, HDTV can display images in a 16:9 ratio, which is wider than the 4:3 ratio of traditional, analog televisions. The standard for the traditional ratio was set in 1889 in Thomas Edison's laboratories; in the 1950s, filmmakers adopted the wider ratio to give viewers a more realistic, immersive experience. HDTV viewers will be able to see films in their original ratio, as well as television programming (such as football games) that will benefit from the wider screen. HDTV requires expensive new production and transmission equipment, but some broadcasters are already airing programs in HDTV. CBS, ABC, and many cable channels have announced plans to air programs such as college football, movies, and primetime comedy and drama series in HDTV.

Eventually, all television programming will be transmitted digitally, and analog programming will cease to exist. Until then, television programmers will operate two channels: one digital and one analog. The Federal Communications Commission (FCC), which oversees the television industry and allocates portions of the airwaves to broadcasters, is directing the slow transition to DTV, which has been hampered by standardization issues and by the massive expense of the effort (estimated at $1.6 billion system-wide). In 1997, the FCC gave broadcasters $70 billion worth of broadcasting spectrum so they could broadcast digital programming alongside their traditional analog programming, and set 2006 as the date by which the transition to digital would be complete, at which point the broadcasters would have to give up their analog signals. However, broadcasters have asked for a delay, citing the tremendous cost involved in switching over to digital, the fact that relatively few stations have made the switch, and the low rate of consumer adoption.

Consumer adoption of DTV has been hindered by the fact that televisions capable of displaying the digital signal correctly are expensive ($1,500 and up). Currently, less than one percent of TV owners have digital TV sets. Another issue is affecting adoption: Hollywood studios were reluctant to release high-resolution, digital versions of their products until a method was in place to combat piracy, because digital signals are far more susceptible to piracy than are analog. With analog media such as videotapes, the quality of the image degrades each time the product is copied, providing a built-in disincentive to create multiple copies of a product; but with digital media, each copy is exactly the same.

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