What Is Digital Cable?
Digital cable is a service offered by most cable television providers that uses a type of compression protocol that allows more channels to be made available using the same cable network that is already in place. Digital cable allows communication too and from the cable box in the user's home which provides the ability to make pay-per-view services available, as well as new “Video on Demand” capabilities. Although the same network is used, a new digital cable box will need to be installed.
Digital cable is not the same thing as High Definition TV although the two are often confused. An HDTV is not required to utilize digital cable, and the picture quality is no better than the traditional analog cable signal. Although some analog cable services offer pay-per-view type offerings, a phone line is required for the cable box to communicate with the service provider.
Although digital cable alone doesn't provide a better picture than analog cable service, it does make transmission of superior services possible. Analog cable normally transmits in 480i, a format that uses 480 interlaced scan lines to produce a picture. The more lines used the clearer and more defined the picture becomes. HDTV formats are generally 1080i (1,080 interlaced lines) or 720p (720 progressive scan lines). Digital cable makes it possible to receive these higher level formats.
Digital cable has no effect on Cable Internet service and is a TV only format.