Digital cable Guide, Meaning , Facts, Information and Description
Digital cable is a term for a type of cable digital television that delivers more channels than possible with analog cable by using digital video compression. Digital cable also enables two-way communication, enabling services such as an on-screen program guide and/or the ability to purchase pay-per-view programming without the use of a phone line. Recently, some companies have also added video on demand services.The standard for HD signal transmission over digital cable television systems in the US is now fixed as QAM 256 (Quadrature Amplitude Modulation), which is technically part of the DVB standard (but not ATSC) and is a de facto cable industry standard. This method has higher bandwidth than 8-VSB, allowing two 19.2 Mbit/s channels in a 6 MHz bandwidth, due to its lower tolerance for errors which are generally less of a concern in a wired environment. The ATSC standards included a provision for 16-VSB transmission over cable at 38.4 Mbit/s, but the encoding never gained wide acceptance.