What is Cable?

Cable television is a system of providing television, radio and other services to consumers via radio frequency signals. The signals are transmitted directly to people's televisions through fixed optical fibers or coaxial cables as opposed to the over-the-air method used in traditional television broadcasting (via radio waves) in which a television antenna or satellite would be required.

Cable: Timeline

Cable Television originated in the UK in 1938, when the first Antenna TV systems were setup in towns such as Bristol and Hull, for homes which couldn't receive transmissions over the air, (however these signals were on the 405 line system). In 1960 rediffusion was setup to provide cable television in the newer 625-line and PAL formats.

In the early 1980s Rediffusion Vision supplemented its service with other channels including The Music box, Mirror vision, Lifestyle screen sport, sky channel and TEN. The service was renamed to Rediffusion Cablevision.

In the UK, the current generation of cable television began in the late 1980s with the issue of franchises to many local operators. These small operations proved uneconomic and there has been a continuing process of consolidation and re-financing.

By the year 2000 the two principal cable operators were NTL and Telewest. NTL's cable service was originally known as CableTel and grew rapidly through the acquisition of, amongst others, ComTel (which itself had bought Telecential), Comcast, Diamond Cable and finally in 1999 the residential and small business operations of Cable and Wireless. Telewest also steadily acquired local operators.

In 2005 it was announced that NTL and Telewest would merge, after a period of co-operation in the preceding few years. This merger was completed on 3 March 2006 with the company being named NTL Incorporated. For the time being the two brand names and services are still being marketed as individual companies. However, following NTL's acquisition of Virgin Mobile, the NTL and Telewest services will be rebranded Virgin Media in the first quarter of 2007 creating a single cable operator covering more than 95% of the UK cable market.

Other cable based services

Coaxial cables are capable of bi-directional carriage of signals as well as the transmission of large amounts of data. Cable television signals use only a portion of the bandwidth available over coaxial lines. This leaves space available for other digital services like broadband internet.

Broadband internet is achieved over coaxial cable by using cable modems to convert the network data into a type of digital signal that can be transferred over coaxial cable.