How does cable television work?
Cable television originally began as a means of delivering television to people residing in deep valleys by means of a coaxial cable strung from a community antenna (hence the old name for cable television, CATV). Originally, engineers used amplifiers to increase delivery distance – only to find that noise and distortion eventually ruined the transmission.The technology eventually evolved to overcome this challenge, with engineers transmitting cable signals between antennas via microwaves.
These days, cable companies pick up televisions channels from all around the world via satellite transmission, then relay them to homes via fiber optic cabling, which doesn’t cause the same severity of signal degradation as coaxial cable. A single fiber optic cable can serve hundreds of households with a minimal need for signal amplifiers. Television programming is emitted from the head-end, which receives programming from a multitude of sources and assigns it to specific channels.
The advent of digital technology and MPEG compression has made it possible for cable providers to offer over a thousand channels of original programming by including up to 10 separate stations within a single analog channel. Digital technology also allows cable providers to encrypt their signal using key cryptography, so that non-subscribers can’t decode the video stream. Older cable anti-theft technology relied upon scrambling, or the removal of bits from the signal that we re-introduced by the cable box at the customer’s home.
Cable television brings you more channels and generally better reception than off-air reception of broadcast television, since TV signals travel to your home by cable – rather than through the air. Television stations from your local area, across the country and around the world are brought into your home through miles of high technology cable. Your television reception is un-interrupted by trees, buildings and other surface obstacles. In addition to certain local TV stations, communications satellites let you receive many additional channels via cable TV. A large selection of viewing choices is available from your cable company. • Individual television programs are produced in many locations around the world. • These programs are transmitted to communication satellites that orbit the earth. These satellites stay in a fixed position 22,300 miles above the earth, allowing them to transmit to your community. • Local satellite dishes receive these signals. • The cable television “head-end
