A television network is a distribution network for television content whereby a central operation provides programming for many television stations. Until the mid-1980s, television programming in most countries of the world was dominated by a small number of broadcast networks. Many early television networks (e.g. the BBC, NBC or CBS) evolved from earlier radio networks.

In countries where most networks broadcast identical, centrally originated content to all their stations and where most individual transmitters therefore operate only as large "repeater stations", the terms television network, television channel and television station have become interchangeable in everyday language, with only professionals in TV-related occupations continuing to make a difference between them. Within the industry, a tiering is sometimes created among groups of networks based on whether their programming is simultaneously originated from a central point, and whether the network master control has the technical and administrative capability to take over the programming of their affiliates in real-time when it deems this necessary—the most common example being breaking national news events.

In North America in particular, many television channels available via cable and satellite television are branded as "networks" but are not truly networks in the sense defined above, as they are singular operations – they have no affiliates or component stations. Such channels are more precisely referred to by terms such as "specialty channels" (Canada) or "cable networks" (U.S.), although the latter term is somewhat of a misnomer, even though these channels are networked across the country by various cable and satellite systems.

A network may or may not produce all of its own programming. If not, production houses such as Warner Bros. and Sony Pictures can distribute their content to the different networks and it is common that a certain production house may have programmes on two or more rival networks. Similarly, some networks may import television programmes from other countries or use archival programming to help complement their schedules.

United States

Television in the United States has long been dominated by the Big Three television networks, ABC, CBS and NBC, but Fox, launched in 1986, has gained prominence and is now considered as part of the "Big Four". The Big Three provide a significant amount of programming to each of their affiliates, including news, prime-time, daytime and sports programming, but still have periods each day when each affiliate can air local programming, such as local news or syndicated programmes. Since the creation of Fox, the number of American television networks has grown, but the amount of programming they provide is often much less: for example, The CW Television Network only broadcasts for ten hours each week, leaving its affiliates free to broadcast a large amount of syndicated programming. Other networks are dedicated to specialist programmes, such as religious programming or services in languages other than English, especially in Spanish.

The largest television network in the United States, however, is the Public Broadcasting Service, a not-for-profit, publicly owned service. In comparison to the commercial networks, there is no central programming arm or unified schedule, meaning that each PBS affiliate has a significant amount of freedom to schedule programmes as it sees fit.

History

NBC set up the first permanent coast-to-coast radio network in the United States by 1928, using dedicated telephone line technology. But the signal from an electronic television system, containing much more information than a radio signal, required a broadband transmission medium. Transmission by a nationwide series of radio relay towers would be possible but extremely expensive.

Researchers at the AT&T subsidiary Bell Telephone Laboratories patented coaxial cable in 1929, primarily as a telephone improvement device. Its high capacity (transmitting 240 telephone calls simultaneously) also made it ideal for long-distance television transmission, where it could handle a frequency band of 1 megahertz. German television first demonstrated such an application in 1936 by relaying televised telephone calls from Berlin to Leipzig, 180 km (112 miles) away, by cable. The network was later extended to television viewing offices in Nuremberg and Munich.

AT&T laid the first L-carrier coaxial cable between New York and Philadelphia, with automatic signal booster stations every 10 miles (16 km), and in 1937 they experimented with transmitting televised motion pictures over the line. Bell Labs gave demonstrations of the New York-Philadelphia television link in 1940–1941. AT&T used the coaxial link to transmit the Republican national convention in June 1940 from Philadelphia to New York City, where it was televised to a few hundred receivers over the NBC station.

NBC had earlier demonstrated an inter-city television broadcast on February 1, 1940, from its station in New York City to another in Schenectady, New York by General Electric relay antennas, and began transmitting some programs on an irregular basis to Philadelphia and Schenectady in 1941. Wartime priorities suspended the manufacture of television and radio equipment for civilian use from April 1, 1942 to October 1, 1945, temporarily shutting down expansion of television networking. However, in 1944 a short film, "Patrolling the Ether", was broadcast simultaneously over three stations as an experiment.

AT&T made its first postwar addition in February 1946, with the completion of a 225-mile (362 km) cable between New York City and Washington, D.C., although a blurry demonstration broadcast showed that it would not be in regular use for several months. The DuMont Television Network, which had begun experimental broadcasts before the war, launched what Newsweek called "the country's first permanent commercial television network" on August 15, 1946, connecting New York with Washington. Not to be outdone, NBC launched what it called "the world's first regularly operating television network" on June 27, 1947, serving New York, Philadelphia, Schenectady and Washington. Baltimore and Boston were added to the NBC television network in late 1947. DuMont and NBC would be joined by CBS and ABC in 1948. In the 1940s, the term "chain broadcasting" was used, as the stations were linked together in long chains along the east coast. But as the networks expanded westward, the interconnected stations formed great networks of connected affiliate stations. By 1949 the networks reached as far west as the Mississippi River, and by 1951, the four networks stretched coast to coast, carried on the new microwave radio relay network of AT&T Long Lines. Only a few local TV stations remained independent of the networks.

Late in the 20th century, cross-country microwave radio relays were replaced by Fixed Service Satellites. Some terrestrial radio relays remained in service for regional connections.

FCC regulations in the United States restricted the number of television stations that could be owned by any one network, company or individual. This led to a system where most local television stations were independently owned, but received programming from the network through a franchising contract, except in a few big cities that had network owned-and-operated stations and independent stations. In the early days of television, when there were often only one or two stations broadcasting in an area, the stations were usually affiliated with several networks and were able to choose which programs to air. Eventually, as more stations were licensed, it became common for each station to be affiliated with only one network and carry all of the "prime time" network programs. Local stations however occasionally break from regularly scheduled network programming, especially when there is breaking local news (e.g. severe weather). Moreover, when stations return to network programming from commercial breaks, the station's logo is displayed in the first few seconds before switching to the network's logo.

Another FCC regulation, the Prime Time Access Rule, restricted the number of hours of network programming that could be broadcast on the local affiliate stations. This was done to encourage the development of locally produced programs and to give local residents access to broadcast time. More often, the result included a substantial amount of syndicated programming, usually consisting of old movies, independently produced and syndicated shows, and reruns of network programs. Occasionally, these shows were presented by a local host, especially in programs that showed cartoons and short comedies intended for children. See List of local children's television series .

Canada

The first Canadian television networks, the English CBC and Radio-Canada in French, were established in 1952 as government-owned networks, but there is a significant presence in other national networks: CTV and Global in English, and TVA and V in French. Smaller television systems, such as A and Citytv also function as mini-networks. Most local television stations in Canada are now owned and operated directly by their network, with only a very few affiliates still operating.

Europe, Asia, Africa and South America

Most television services outside North America are national networks established by a combination of publicly-funded broadcasters and commercial broadcasters. Most nations established television networks in a similar way: the first television service in each country was operated by a public broadcaster, often funded by a TV licensing fee, and most of them later established a second or even third station providing a greater variety of content. Commercial television services also became available when private companies applied for television broadcasting licenses. Often, each new network would be identified with their channel number, so that individual stations would often be numbered One, Two, Three, and so forth.

United Kingdom

The first television service in the United Kingdom was provided by the BBC, but commercial broadcasting was established in order to create a second television service. Rather than creating a single network owned by a single company, each region had an separate television company independent from any other, although most of these stations shared a number of programmes. Gradually, each of these stations adopted a single national schedule, forming the ITV Network.

When UHF television allowed a greater number of television stations to broadcast, the BBC launched BBC Two (and the original service was later renamed BBC One), and a second commercial network was launched, Channel 4, although Wales introduced a Welsh-language service instead, S4C. A fifth network, currently called Five, was later launched. Since the introduction of digital television, the BBC, ITV, Channel Four and Five each introduced a number of digital-only channels.

Netherlands

Until 1989, Netherlands Public Broadcasting was the only television network in the Netherlands, with three stations, Nederland 1, Nederland 2 and Nederland 3. Rather than having a single production arm, there are a number of public broadcasting organizations that create programming for each of the three stations, each working relatively independently. Commercial broadcasting in the Netherlands is currently operated by two networks, RTL Nederland and SBS Broadcasting, which together broadcast seven commercial stations.

Australia

Australia has two national public networks, the ABC and SBS. The ABC operates eight stations as part of its main network ABC1, one for each state and territory, as well as two digital only channels, ABC2 and the planned ABC3. Although SBS was originally founded as a multilingual network, featuring programmmes in languages other than English, it gradually adopted more populist programming, and, although funded mostly through government grants, is partially funded through advertising. It currently operates two stations, SBS One and SBS Two.

The first commercial networks in Australia involved commercial stations in Sydney, Melbourne, Brisbane, Adelaide, and, later, Perth, sharing programming, with each network forming networks based on their allocated channel numbers: TCN-9 Sydney, GTV-9 Melbourne, QTQ-9 Brisbane, NWS-9 Adelaide and STW-9 Perth together formed the Nine Network, while their equivalents on VHF channels 7 and 10 formed the Seven Network and Network Ten respectively. Until 1989, areas outside of these main cities had access to only a single commercial station, and these rural stations often formed small networks such as Prime Television. Beginning in 1989, however, television markets in rural areas began to aggregate, allowing these rural networks to broadcast over a larger area, often an entire state, and become full-time affiliates to one specific metropolitan network.

Philippines

In the Philippines, in practice, the terms network, station and channel are used interchangeably as programming line-ups are mostly centrally planned from the networks' main offices, and since provincial/regional stations usually just relay the broadcast from their parent network's flagship station (usually based in the Mega Manila area). Hence VHF networks are sometimes informally referred to by the channel number they are seen on terrestrial TV in the Mega Manila area (e.g. Channel 2 or Dos for ABS-CBN) while some networks have the channel numbers in their name (e.g. TV5, C/S9, Studio 23 and Net 25 which are seen on channels 23 and 25 respectively).

Unlike the US where networks get programmes from various production houses, the two largest networks in the Philippines produce all their primetime programmes except for Asianovelas. Other networks adopt block-time programming whose programming arrangements are similar to the relationship between a US network and station.

References

1. " Coaxial Cable", Time, Oct. 14, 1935.
2. Television in Germany, Berlin, 1936.
3. " Television 'Piped' From New York to Philadelphia," Short Wave & Television, February 1938, pp. 534, 574-575.
4. GOP Convention of 1940 in Philadelphia, UShistory.org.
5. Weinstein, David (2004). The Forgotten Network: DuMont and the Birth of American Television Temple University Press: Philadelphia, p. 16-17. ISBN 1-59213-499-8.
6. " Beginning," Time, July 7, 1947.
7. "The Impact of the FCC's Chain Broadcasting Rules". The Yale Law Journal, 60(1) (1951): 78-111

See also

• List of television networks by country
• Television system