Cable television
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- Cable TV redirects here. For the Hong Kong-based cable television network, see Cable TV Hong Kong.
Cable television is a system of providing television, FM radio programming and other services to consumers via radio frequency signals 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 is required.
It should be noted that while the acronym CATV is often mistaken for "Cable TV" or "Community Access Television," it actually stands for Community Antenna Television. This comes from cable television's origins, in 1938, when the first cable systems were started. Television signals could only be received by homes that were in the "line-of-sight" of the originating broadcast antenna, and people in mountainous areas could not receive the signal. Large antennas were constructed in these areas, and cable was run from the antenna to homes in the area so they could receive programming, making these large antennas "community antennas."
It is most commonplace in North America, Europe, Australia and East Asia, though it is present in many other countries, mainly in South America and the Middle East. Cable TV has had little success in Africa, as it is not cost-effective to lay cables in sparsely populated areas, and although so-called "wireless cable" or microwave-based systems are used, "direct-to-home" satellite television is far more popular, especially in South Africa.
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[edit] Technology
Technically, CATV involves distributing a number of television channels collected at a central location (called a headend) to subscribers within a community by means of a branched network of optical fibers and/or coaxial cables and broadband amplifiers. Since the early 1990s, the most common architecture is the Hybrid fiber coaxial network.
As 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. A Set-top box or the tuner of the TV, VCR or radio selects one channel from this mixed signal.
The same program is often simultaneously broadcast by radio 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.
Traditional cable TV systems worked strictly by way of analog signals (i.e. using standard radio waves) but many modern cable TV systems also employ the use of digital cable technology, which uses compressed digital signals, allowing them to provide many more channels than they could with analog alone. Modern cable TV systems also offer other services such as Video on demand, telephony, and high-speed data.
Cable television is normally regarded as a natural monopoly, and most areas are served by a single provider, though Australia is characterized by extensive duplication.
[edit] Cable television deployments
[edit] Australia
Cable television services have been available in Australia since 1995. There are currently two major and four minor cable television providers in Australia - Foxtel and Optus TV. Minor providers include Austar, TransACT, Bright Telecommunications and Neighbourhood Cable, which only operate in limited areas.
Like the UK, cable is a minority means of receiving access to subscription television in Australia. Satellite distribution is more common.
Due to its history, financial backing and market dominance, most local versions of channels are either owned directly by Foxtel and Austar or through related companies.
In terms of coverage, Foxtel's cable network covers parts of Sydney, Melbourne, Brisbane, Adelaide, and Perth. Optus's network covers small parts of Sydney, Melbourne, and Brisbane, though its restrictive subscription rules means that many people living in apartments or confined living areas are unable to be connected.
Austar is available by satellite in most of regional and rural Australia, but does have a small cable network in the city of Darwin. TransACT is only available in the city of Canberra, where a custom cable network was developed. A similar situation exists in Perth where a small area is covered by Bright Telecommunications as well in parts of Geelong, Ballarat and Mildura that are reached by Neighbourhood Cable.
[edit] Canada
[edit] Hong Kong
Only one traditional cable provider operates in Hong Kong, i-Cable Communications Limited (branded as "CableTV"). Another three operators offers pay-TV via DSL, they are Now Broadband TV (PCCW), HKBN Digital TV and TVB PayVision.
Many in Hong Kong instead watch subscription TV using satellite systems like STAR TV.
[edit] Mexico
The first cable system started to operate in the early Sixties in Monterrey, as a CATV service (an antenna at the top of the Loma Larga, which could get TV signals from South Texas). Most of the other major cities didn't develop cable systems until the late Eighties, due to government censorship. By 1989 the industry had had a major impulse with the founding of Multivisión—a MMDS system who started to develop its own channels in Spanish—and the later development of companies such as Cablemas and Megacable.
Over the past few years, many US networks have started to develop content for the Latin American market, such as CNN en Español, MTV, Cartoon Network, Disney Channel, and others. The country also has a DTH service called SKY (Televisa & News Corp. owned). Recently DirecTV merged with Sky. The dominant company nowadays is Megacable and Grupo HEVI.
[edit] New Zealand
TelstraClear operate a cable television network in Wellington, Kapati and Christchurch. Customers can subscribe to plans incorporating between 25 and 95 channels. Most content is offered on behalf of Sky Network Television however some channels such as TBN, Discovery Travel and Adventure and Deutsche welle are broadcast exclusively through TelstraClear.
[edit] Republic of Ireland
[edit] South Africa
South African Broadcasting Co-operation (SABC) and e-TV are the only broadcasters in the country with the SABC being the major breoadcastor and people's choice. The SABC has three channels which focuses on its diverse cultures, languages and heritages. These channels are called SABC 1, 2, and 3. On the other hand, e-TV has only one channel and struggles to broadcast all the programmes. With SABC having the leading news channels in Africa one can't help but wonder why other channels even compite with it.
[edit] Singapore
StarHub Cable Vision is the sole cable television operator in Singapore, where private ownership of satellite dishes is banned. StarHub Cable Vision was formed as a result of a merger between StarHub and Singapore Cable Vision on 15 May 2002. The latter first began broadcasting as a terrestrial pay-television operator in 1992 as the first cable network was not completed until 1995. Around 15% of households and offices in Singapore are connected to the StarHub network.
[edit] United Kingdom
In the UK Cable Television had its origins in 1938, when the first Community Antenna TV systems were setup in towns including Bristol and Hull, for homes which couldn't receive transmissions over the air; however these signals were on the 405-line system. In the 1960s Rediffusion Vision 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, Mirrorvision, Lifesyle Screensport, Sky Channel and TEN. The service was renamed to Rediffusion Cablevision.
In the United Kingdom, 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 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, among others, ComTel (which itself had bought Telecential), Comcast, Diamond Cable and finally, in 1999, the residential and small business operations of Cable & 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 separately. However, following NTL's aqusition of Virgin Mobile, the NTL and Telewest services will be rebranded Virgin Media in the first quarter of 2007[1] creating a single cable operator covering more than 95% of the UK cable market.
There are a small number of other surviving cable television companies in the UK outside of NTL including Kingston Communications (East Riding of Yorkshire) and WightCable (Isle of Wight, Ayrshire, Carlisle and Lancashire).
Cable TV faces intense competition from BSkyB's Sky Digital satellite television service. Most channels are carried on both platforms. However, cable often lacks "interactive" features (e.g. text services, and extra video-screens), especially on BSkyB owned channels, and the satellite platform lacks services requiring high degrees of two-way communication, such as true video on demand.
However, subscription-funded digital terrestrial television proved less of a competitive threat. The first system, ITV Digital, went into liquidation in 2002. Top Up TV later replaced it, however this service is shrinking as the DVB-T multiplex owners are finding FTA broadcasting more profitable.
Another potential source of competition in the future will be TV over broadband. This was initially launched, using ADSL, in London, where it is provided by HomeChoice. An IPTV service was also provided in Hull by Kingston Communications, but this ceased operations in April 2006. As the speed and availability of broadband connections increase, more TV content can be delivered using protocols such as IPTV.
[edit] United States
The majority of American television viewers get their signal from CATV.
[edit] Europe
According to the European Audiovisual Observatory, there were 58 million cable households in the European Union as of 31 December 2004, i.e. a rate of penetration of 32 % of the television households. 5.7 millions were connected to digital networks.
[edit] Switzerland
In Switzerland, virtually all households have cable TV. Ironically, despite this good coverage, Switzerland has only a few public TV stations (two each for the German, French and Italian-speaking parts of the country); additionally, there is now only one upstart commercial network with coverage comparable to these state-run channels. To watch news or political information, Swiss channels are preferred, but in the entertainment sector (feature movies, comedies, talk shows), private TV stations from Germany, France and Italy are dominant.
[edit] 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 plenty of space available for other digital services such as broadband internet and cable telephony.
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. One problem with some cable systems is the older amplifiers placed along the cable routes are unidirectional thus in order to allow for uploading of data the customer would need to use an analog modem to provide for the upstream connection. This limited the upstream speed to 31.2k and prevented the always-on convenience broadband internet typically provides. Many large cable systems have upgraded or are upgrading their equipment to allow for bi-directional signals, thus allowing for greater upload speed and always-on convenience, though these upgrades are expensive.
In North America and Europe many cable operators have already introduced cable telephone service, which operates just like existing fixed line operators. This service involves installing a special telephone interface at the customer's premises that converts the analog signals from the customer's in-home wiring into a digital signal, which is then sent on the local loop (replacing the analog last mile, or POTS) to the company's switching center, where it is connected to the PSTN. The biggest obstacle to cable telephone service is the need for nearly 100% reliable service for emergency calls. One of the standards available for digital cable telephony, PacketCable, seems to be the most promising and able to work with the Quality of Service demands of traditional analog POTS service. The biggest advantage to digital cable telephone service is similar to the advantage of digital cable TV, namely that data can be compressed, resulting in much less bandwidth used than a dedicated analog circuit-switched service. Other advantages include better voice quality and integration to a VoIP network providing cheap or unlimited nationwide and international calling. Note that in many cases, digital cable telephone service is separate from cable modem service being offered by many cable companies and does not rely on IP traffic or the Internet.
Beginning in 2004 in the United States, the traditional cable television providers and traditional telecommunication companies increasingly compete in providing voice, video and data services to residences. The combination of TV, telephony and Internet access is commonly called triple play regardless of whether CATV or telcos offer it.
[edit] References
- ^ NTL (2006-11-08). Virgin Media is on its way. Press release. Retrieved on 2006-12-06.
