Digital
Television (DTV)
DTV is a new type of
broadcasting technology that will transform television as we now know
it. By transmitting the information used to make a TV picture and sound
as "data bits" (like a computer), a digital broadcaster can carry more
information than is currently possible with analog broadcast technology.
For example, the technology allows the
transmission of pictures with higher resolution for dramatically better
picture and sound quality than currently available - called High
Definition Television (HDTV) - or the transmission of several
"standard definition" TV programs at once - called "multicasting."
"Standard definition" digital TV
pictures would be similar in clarity and detail to the best TV pictures
being received and displayed today using the current analog broadcast
system and TV receivers. |
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How will digital
television be different than the current analog television?
DTV - Digital Television allows
a number of new and better services. With HDTV, broadcasters can
offer far higher resolution and picture quality than exists with Analog
technology. Or, they can offer several different TV programs at the same
time, with pictures and sound quality equal to or better than is
generally available today.
In addition, broadcasters can
simultaneously transmit a variety of other information through a data
bitstream to both enhance the TV programming and to provide entirely new
services.
What is high
definition TV (HDTV)? How is it different from analog television?
HDTV is a name given to two of
the digital television (DTV) formats. HDTV provides high
resolution programming. A current analog TV picture is made up of
horizontal lines on the picture screen; an HDTV picture can have more
than twice as many lines, allowing for stunning picture detail.
HDTV uses a "widescreen format." "Widescreen format" refers to an
image's aspect ratio, which is a comparison of screen width to screen
height. Analog television has an aspect ratio of 4 by 3, which means the
screen is 4 units wide by 3 units high. The aspect ratio of HDTV is 16
by 9, similar to a movie theater screen. HDTV programs can include Dolby
Digital surround sound, the same digital sound system used in many movie
theaters and DVDs.
HDTV uses the same amount of bandwidth (the size of the
communications channel) as the current analog system, but with HDTV,
about six times more information is transmitted. This capability
translates to much better quality in picture and sound. |
How do I get DTV or
HDTV?
Receiving the DTV and HDTV
signals over-the-air requires an antenna and a new DTV receiver that can
decode the digital signals. In general, an antenna that provides quality
reception of over-the-air analog TV signals will work for DTV reception.
If you are a cable or satellite customer, you may need a set-top box
to receive DTV signals and convert them into the format of your current
analog television, even after the DTV transition is complete. A DTV
set-top box also may receive multicast channels and high definition
programming and display them in analog picture quality. Check with your
cable or satellite provider to determine if and when you will need a
set-top box.
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