Cable television or Community Antenna Television (CATV) (and often shortened to 'cable') refers to television, FM radio programming and other services that are provided to consumers via fixed coaxial cables, rather than by the older and more widespread radio broadcasting (over-the-air) method. It is most common in Canada, the United States, Europe, most of Australasia and much of eastern Asia, though it is present in many other countries.
Technically, both cable TV and CATV involve distributing a number of televisionchannels collected at a central location (called a head end or headend) to subscribers within a community by means of a network of optical fibers and/or coaxial cables and broadband amplifiers.
Like in the case of radio broadcasting, the use of different frequencies allows many channels to be distributed through the same cable, without separate wires for each. The tuner of the TV, VCR or radio selects from this mixed signal one channel.
The same program is often simultaneously radio broadcast and distributed by cable, usually at different frequencies. Other programs may be distributed by cable only; rules restricting content (e.g. regarding nudity and pornography) are often more relaxed for cable than for over-the-air TV.
Another system in Mahanoy City was founded by Jerrold Electronics Corp. which served the other side of town. Both were originally three-channel systems and were upgraded to five. Other systems were built: some conceived the idea independently, others didn't, and others laid claim to the title of first.
On August 1, 1949 T.J. Slowie, a secretary of the Federal Communications Commission, sent a letter to a CATV pioneer in Astoria, Oregon, L.E. Parsons, requesting he "furnish the Commission full information with respect to the nature of the system you may have developed and may be operating." He did. This is the first known involvement of the FCC in CATV. An FCC lawyer, E. Stratford Smith, determined the Commission could exercise common carrier jurisdiction over CATV. The FCC didn't act on this opinion and Smith later changed his mind after working in the cable industry for some time and testifying in Senate committee hearings. Senator and future Federal Communications Commissioner Kenneth A. Cox attended and participated in these hearings. He prepared a report entitled the Cox Report for the Senate Committee on Interstate and Foreign Commerce. This report was against CATV and supported the FCC policy of a television station in every community.
In 1959 and 1961 bills were introduced in Congress that would have determined the role of the FCC in CATV policy. The 1959 bill, which actually made it to the floor of the Senate, would have limited FCC jurisdiction to CATV systems within the contours, i.e. the broadcast range, of a single station. It was defeated. The 1961 bill proposed by the FCC would have given the Commission authority over CATV as CATV, and not as a common carrier or broadcaster. The Commission could then adopt rules and regulations "in the public interest" to govern CATV in any area covered both by CATV and broadcast television. No action was ever taken on this bill.
More important than Congressional action in determining Federal Communications Commission CATV policy were court cases and FCC hearings. Frontier Broadcasting Co. v. Collier was a hearing in which broadcasters tried to get the FCC to exercise common carrier authority over 288 CATV systems in 36 states. The broadcasters maintained that CATV went against the FCC's Sixth Report and Order, which advocated at least one television station in every community. The FCC, in 1958, decided that CATV was not really a common carrier since the subscriber did not determine the programming. Carter Mountain Transmission Corp., a common carrier that already transmitted television signals by microwave to CATV systems in several Wyoming towns, wanted to add a second signal to two of the towns and add two signals to a previously unserved town. A television station in one town opposed this and protested to the FCC on the grounds of economic damage. A hearing examiner supported Carter Mountain but the Commission supported the television station. The case was taken to appeal, as most are, and the Federal Communications Commission won. "The fact that no broadcaster has actually gone off the air due to CATV competition at the time the government moved to expand its authority (nor have any since) did not stay the momentum for the expansion of regulatory authority. That some economic impact was merely plausible sufficed as the basis for government concern and government action." The FCC overruled a hearing examiner in favor of broadcasters again in the "San Diego Case". The CATV systems in San Diego, California wanted to import stations from Los Angeles, some of which could be seen in San Diego; the television stations in San Diego didn't want the signals imported. The television stations won, not allowing the signals on future cable lines in San Diego and its environs. The FCC's reasoning was to protect the present and future UHF stations in San Diego.
In the First Report and Order by the Federal Communications Commission on CATV the FCC gave itself the power to regulate CATV. This Report and Order was designed to protect small town television stations. It did this by imposing two rules, which in slightly altered form still stand: one requires that a CATV system carry all local stations in which the CATV system is in the "A" (best reception) contour of the station. The second prohibits the importation of programs from a non-local station that duplicates programming on a local station if the duplication is shown either 15 days before or 15 days after its local airing. This 1965 report reasoning is as follows: 1) CATV should carry local stations because CATV supplements, not replaces, local stations and the non-carriage of local stations gives distant stations an advantage since people will not change from the cable to the antenna to see a local station; 2) non-carriage is "inherently contrary to the public interest"; 3) CATV duplication of local programming via distant signals is unfair since broadcasters and CATV do not compete for programs on an equal footing; the FCC recommends "a reasonable measure of exclusivity".
The 1966 Second Report and Order made some minor changes in the First Report and Order and added a major regulation. This was designed to protect UHF stations in large cities. The new rule disallowed the importation of distant signals into the top 100 markets, thus making CATV profitable only in cities with poor reception. In 1968 the Supreme Court upheld the FCC's right to make rules and regulations concerning CATV. In its decision on United States v. Southwestern Cable, the "San Diego Case", it said "the Commissions authority over 'all interstate ... communications by wire or radio' permits the regulation of CATV systems."
In 1969 the FCC issued rules requiring all CATV systems with over 3500 subscribers to have facilities for local origination of programming by April 1, 1971. The date was later suspended. Dean Burch, in 1972, steered the FCC into a new area of regulation. It lifted its restrictions on CATV in large cities, but now put the burden of more local programming on CATV operators. In 1976, the FCC used its rule making power to require that new systems now had to have 20 channels, and that cable providers with systems of 3500 subscribers or more had to provide PEG (public, education, and government access) channel capacity, and facilities and equipment necessary to use this capacity. Public Access Television remains of major importance to progressives, environmentalists, community activists, artists, radicals, scholars, and independent filmmakers who cannot find a forum in profit-oriented commercial broadcasting.
There is much less of a restriction on adult-oriented content such as nudity and strong language, because the signals are not transmitted over the airwaves where anyone with a television set (including children) can receive them. Audience numbers tend to be smaller, so more specialized programming (such as minority sports) is acceptable. Greater bandwidth is available than with broadcast, so there are 10 to 20 times as many channels. Cable imposes a charge for service, depending on the number and perceived quality of the channels available. This has a positive side, as advertisement breaks on cable are either absent or their number and duration are far lower than on broadcast, where ads make up around 25% of programming in the US. By coding signals and having decoding equipment in the homes it also enables subscription based channels and pay-per-view services.
Starting in the late 1990s, advances in digital signal compression (primarily Motorola's DigiCipher 2 technology in North America) technology have given rise to wider implementation of digital cable services. Digital cable provides many more television channels over the same available bandwidth, usually for a higher monthly subscription fee. The downside to digital compression is its tendency to soften the quality of the television picture.
In the United States, cable companies typically receive exclusive rights to serve a region as a result of a franchise agreement with a local government.
Cable companies have recently expanded their service to provide broadband internet services through their cables, using cable modems, as opposed to ADSL through the telephone cable. Cable internet service has become relatively popular, often far more so than DSL.
A chart showing the North American cable television bandplan can be found here.