Cable digital TV is a method of broadcasting television to a viewer's home through an entirely physical connection. Its benefits include more channels and better picture quality. Unlike analog TV, it allows two-way communication down a single cable, making added services possible.
The most marketed benefit of cable digital TV is that it carries more channels. This is because digital television does a much better job of efficiently carrying the information for each channel. This allows stations to offer a wider variety of channels, some of which may be from smaller TV networks or even standalone channels. It also allows mainstream channels to offer sister channels which concentrate on a particular aspect of its programming, such as a history channel offering a channel concentrating solely on military history. The extra slots can also be used for timeshifted channels which broadcast the same programming as the main channel but on a one-hour delay, which can be more convenient for viewers and help resolve scheduling conflicts.
Cable digital TV also offers a much better picture quality in most cases. This is possible because digital TV carries more chroma information than its analog counterpart. This means the colors displayed are more true to the original image, which makes for a more vivid picture. One drawback is that some carriers will compress the information for each channel too much, to the point that the picture is noticeable less detailed.
In most cases digital cable is less susceptible to interference than analog cable. This means viewers do not get the problems of snow and fuzzy pictures that can occur with poor analog signals. However, in the rare instances of poor quality digital signals, the viewer is more likely to be left with no picture whatsoever.
For cable viewers, high definition pictures are only available through digital cable TV. This is because analog set-ups are limited to 480 vertical lines of pixels, while HD is usually defined as having a minimum of 720 lines. Viewers will usually find that analog TV signals which appeared fine on a standard definition TV are noticeably poor on an HD set.
Another advantage of cable digital TV is that signals can be carried in both directions. This differs from analog cable where the viewer has to connect their cable box to a telephone line to send information, for example when ordering a pay-per-view event. Digital cable makes it possible for broadcasters to offer video on demand services, both as part of a subscription package and on a pay-per-view basis.