This chapter is from the book
This chapter is from the book
This chapter is from the book
How Digital Television Works
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.
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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.