DTV is more advanced than the older
analog technology. Unlike analog television, which uses a continuously variable
signal, a digital broadcast converts the programming into a stream of binary
on/off bits—sequences of 0s and 1s. This is the same way that computers store
information in data files; each bit represents a small part of the picture, and
all the bits combine to reproduce the original picture.
Digital television converts the
picture into a stream of 0s and 1s.
The primary advantage of digital
broadcasting is that these binary bits recombine to reproduce an exact copy of
the original material. The picture and sound received from a digital
transmission are always identical to the original source.
Even better, over-the-air digital
signals don’t weaken over distance, as analog signals do. As long as the signal
can be received, the picture is perfect, with no degradation or ghosting.
Because digital signals are composed of binary bits, a 1 is always a 1, and a 0
is always a 0. There is no fuzziness or snow in the picture, no ghosts caused
by interference.
In addition, digital is a more
efficient technology. A digital transmission requires less bandwidth than does
a similar analog broadcast; this lets local television stations broadcast two,
three, or even four digital channels in the space of a single analog channel.
This “multicasting” technology means you’ll receive more variety in programming
from your local stations—all delivered with superior digital quality.
NOTE
It’s important to note that DTV is
not the same as high-definition television. Whereas all HDTV is digital, not
all digital broadcasts are high definition. Learn more in Chapter 3, “Digital
Versus High Definition: What’s the Difference?”
for more about digital vs analogue TV read here
