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2.
INTRODUCTION:
THE BASICS
Digital Television (DTV)
Television
broadcasting
is changing. By February of 2009, traditional
analog TV
transmissions
(the standard since TV's inception) will cease to exist, in
compliance
with a federal mandate requiring all U.S. television
stations to convert
from analog to the new digital television
(DTV) standards.
In contrast to the magnetic waves used for analog transmission
(also known as
NTSC, short for National Television Standards Committee),
DTV transmits
images and sound as data, using ones and zeroes, the same digital code
computers
use. As a result of this increased efficiency,
DTV offers an array of
benefits including dramatic improvements
to picture and sound quality. In addition,
DTV allows the same number of stations to broadcast
using fewer channels,
freeing parts of the broadcast spectrum for other uses, such as public safety and
wireless services
NUi%_) D YV should not be confused
with dif_ita/ c_,b/e or dif_it_/ sate/rite syr_tenls.
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High Definition Television
(HDTV)
The most common DTV formats are Standard Definition Television
(SDTV) and
High Definition Television
(HDTV). Of the two, HDTV delivers digital
broadcasting's
highest resolution and picture quality.
HDTV also uses a
"widescreen
format," which refers to the aspect ratio (screen width vs. height) of
the image. To put this in perspective,
analog television
uses a 4 x 3 aspect ratio;
HDTV's aspect ratio is 16 x 9, creating a more cinematic-like
viewing experience.
Plus HDTV increases the number of horizontal scan lines on the screen, enabling
it to render greater picture detail. And, while HDTV uses approximately
the same
bandwidth,
it transmits approximately
six times more information,
further
enhancing video and audio clarity.
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