Data Over Cable Service Interface Specification (DOCSIS) is an international telecommunications standard that permits the addition of high-bandwidth data transfer to an existing cable television (CATV) system. It is used by many cable television operators to provide cable Internet access over their existing hybrid fiber-coaxial (HFC) infrastructure.
A DOCSIS 3.0 cable modem
A cable modem termination system (CMTS)
Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with broadcast television, in which the television signal is transmitted over-the-air by radio waves and received by a television antenna attached to the television; or satellite television, in which the television signal is transmitted over-the-air by radio waves from a communications satellite orbiting the Earth, and received by a satellite dish antenna on the roof. FM radio programming, high-speed Internet, telephone services, and similar non-television services may also be provided through these cables. Analog television was standard in the 20th century, but since the 2000s, cable systems have been upgraded to digital cable operation.
A coaxial cable used to carry cable television onto subscribers' premises
A set-top box, an electronic device which cable subscribers use to connect the cable signal to their television sets. Presented unit is a Cisco RNG200N for QAM digital cable television system used in North America.
A cable television distribution box (left) in the basement of a building in Germany (Kabel BW network, now Vodafone), with a splitter (right) which supplies the signal to separate cables which go to different rooms
Demonstration of a 30-channel cable TV system in the Netherlands in March 1981.
