Times Article 015
High-Definition (Television (HDTV) Information
our computer technology accelerating as fast as it is, it seems a bit
surprising to realize that the television we watch today isn't really
very different than the technology used since the mid-1950s. Well,
that's about to change.
April 4, 1997, the Federal Communications Commission awarded 6 MHz (or
19.3 Mbits/second) of frequency spectrum to each of approximately
1,500 television stations for Digital Television (DTV) broadcasting.
By doing so, the FCC opened a whole new era for TV watchers and
computer users alike.
decreed that the three commercial networks in the top 10 U.S. markets
were to start broadcasting digitally by May 1, 1999, with markets in
the 11th through 30th spots coming online by
November 1, 1999. All U.S. TV stations must broadcast digitally by May
1, 2003, as the current analog TV spectrum is scheduled to revert back
to the FCC on January 1, 2007. Somewhat unfortunately, the FCC decree
did not specifically define DTV, and, in fact, lists 36 possible
formats for digital transmission.
lack of definition is now the battleground between the TV networks and
the computer industry. And at stake in this war is (1) how soon DTV
will deliver high-definition content to those who do not buy DTV sets,
and (2) whether your DTV will sport the familiar Microsoft Windows and
start off with some basics. Your current television screen shows an
analog signal that is strictly mandated by the National Television
Systems Committee (NTSC). This signal has a standard resolution of
512X486, a 4:3 aspect ratio (screen width:height), and a frame-rate of
30 frames each second (actually 29.97). When you go to the movies,
you're seeing much higher film resolution and a wide-screen 16:9
aspect ratio at 24 frames/second (FPS). DTV is intended to give you
about the same quality as the movie screen in the comfort of your own
parameters define each of the new DTV formats: resolution, scan type,
and frame-rate. Four resolutions are acceptable to the FCC: 1920X1080,
1280X720, 720X480, and 640X480. The first two resolutions are called
High-Definition (HDTV), and the last two are called
type refers to progressive scan versus interlaced scan. Current NTSC
video is interlaced: each of the 29.97 frames that make up each second
of TV video is split into two fields, odd and even, that are
interlaced together. Computer monitors are progressive-scan devices,
where every line of the entire frame is updated from top to bottom, at
a rate determined by a combination of your video board and the
monitor's internal specifications.
last DTV variable is frame-rate, or the number of times the screen is
updated each second. Each resolution supports multiple frame-rates and
scan types. For example, 1920X1080 supports 30 FPS in both interlaced
and progressive modes, as well as 24 FPS in progressive mode.
the 1920X1080 interlaced (1080i) format are CBS, NBC, Sony, and Warner
Brothers. They believe DTV should be as close as possible to the same
quality as the 35mm film you see at the movies, wide-screen and all.
The first problem with this approach is that we will need a big-screen
TV, which could cost $5,000 or more, and may leave some viewers
without the deep pockets to buy them. Second, the 1080i signal uses
the entire 6 MHz allocation, which leaves no room for other digital
other DTV team consists of Compaq, Microsoft, Intel, Lucent, ABC, and
Fox, which supports the 1280X720 progressive (720p) format. This
format allows plenty of spectrum bandwidth for other digital content,
which can be another channel, Web-based content, or data multicasting
(showing both HDTV and SDTV). The second advantage is that computers
can easily support 720p DTV with minimal upgrades (around $100). This
could dramatically increase the number of DTV viewers near-term.
our first choice appears to be better-quality content (1080i) that few
people can afford, and that offers none of the other perceived
benefits of digital transmission. The real unstated benefit of 1080i
seems to be maintaining the apartheid of computers and TV sets...and
keeping Wintel out of the living room. Our second choice (720p)
promotes – again unstated – computers as the preferred viewing
devices, giving Intel and Microsoft a huge advantage over the
add to this confusion, the Motion Picture Association of America (MPAA)
is worried that converting all video and audio content to
computer-compatible digital data will cause their clients (all the
major producers of movie and TV programming) a world of hurt. One
popular proposal for early adopters of DTV is to use a digital cable
into a low-cost "set-top box" that will then be connected to
your TV via a familiar interface: FireWire, or IEEE-1394. FireWire is
already the standard for camcorders, digital VCRs, and DVD players, to
name a few.
suppose some pay-per-view service offers a new hit movie, and you, the
consumer, use your FireWire connection to record that movie to your new
DVD recorder. Then suppose you loan your copy to two of your friends,
who in turn make digital copies, and so on until everyone has a copy,
with only you having paid for it. MPAA has used this horror story to
convince Congress to pass legislation that called for copy management in
consumer digital audio recorders, which is why DAT has never become a
of course there is no guarantee that DTV will become an overnight
success story, either. In 1965, 11 years after NTSC color TV was
introduced, only about five percent of the U.S. had a color set. But by
1975, that number had rocketed to over 75 percent. So will broadcasters
give us a reason to buy DTV sets? Will they commit to providing
significant coverage of multichannel surround-sound, data-enhanced
interactive programming, and digital-quality super-hits?
one knows, but there a lot of companies betting the farm on it.