Cable television
Cable TV redirects here. For the Hong Kong-based cable television network, see Cable TV Hong Kong. |
Coaxial cable is often used to transmit cable television into the house. |
Cable television or
Community Antenna Television (
CATV) (often shortened to
cable) 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 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.
Technically, both cable TV and CATV involve distributing a number of
television channels collected at a central location (called a
headend) to
subscribers within a community by means of a network of
optical fibers and/or
coaxial cables and
broadband amplifiers.
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. 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.
Many cable television systems were formerly known as CATV (Community Antenna Television) systems as they were originally composed simply of a shared antenna located in a high location to which multiple households could have their TVs connected via coaxial cable. This was designed to provide access to television signals in areas where reception was traditionally poor. As cable-only networks began to appear on CATV systems, picked up via satellite rather than by antenna, the use of the term CATV has largely faded and the term cable television has taken its place.
Cable television is normally regarded as a
natural monopoly, and most areas are served by a single provider, though
Australia is characterised by extensive
duplication.
Australia
Cable television services have been available in Australia since 1995. There are currently three major and four minor digital cable television providers in Australia -
Foxtel, which is a 50/50 joint agreement by
Telstra and
News Corp,
Optus TV and
Austar. A newcomer,
SelecTV, provides a cheaper service with a more limited array of channels and features. Other minor providers include
TransACT,
Bright Telecommunications and
Neighbourhood Cable, which only operate in specific regional areas.
Services, channels and usability have drastically improved since the days of analogue. While many people outside the capital cities are still unable to reach the cable network, satellite services provided by the top providers have now been able to provide the same standard of quality and usability (Video on Demand, Live TV Manipulation, Dolby Digital) that cable subscribers are able to access.
Most providers are able to offer in excess of 60 channels, including 24-hour news services, movie channels, on-demand events and films, as well as terrestrial digital (DVB) free-to-air channels. Features such as timeshifting, on-demand recording, games and interactive TV are also available. Channels include but aren't limited to
Discovery Channel,
History Channel,
Showtime Australia,
Sky News Australia,
Movie Network (A group of 3 separate movie channels),
CNN,
BBC World,
MTV,
ESPN and more.
Due to its history, financial backing and market dominance, most locally produced content and channels are either owned directly by Foxtel or through subsidiary companies. Channels that Foxtel own are then wholesaled to other providers, while individual channels not owned by Foxel will sell their licensing rights in content sharing agreements. This way, all providers are able to share from the same pool of channels, while still being able to set their own pricing, packages and brand.
In terms of coverage,
Foxtel's cable network covers most 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 regional and rural Australia, but does have a small cable network in the city of
Darwin.
Austar and
Foxtel only compete for customers in the Gold Coast but by a mutual non-compete agreement,
Foxtel limits its market to the capital cities and
Austar limits its market to regional and rural areas.
The other provider,
TransACT, is only available in the city of
Canberra, where a custom cable network was developed. A simular 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.
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.
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.
Republic of Ireland
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.
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,
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 3rd March 2006 with the company being named
NTL Incorportated. For the time being the two brand names and services will still be marketed separately however are to be slowly integrated to create a single cable operator for more than 95% of the UK market, likely under the
Virgin Group brand if NTL's April 2006 aqusition of
Virgin Mobile is accepted.
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
SkyDigital's
satellite television service, although most channels on that platform are also carried on cable (however they do lack features- for example interaction news or football - available to Sky Digital viewers). Very few channels are now exclusive to cable, usually channels showing local programming. However, subscription-funded
digital terrestrial television proved less of a competitive threat, as
ITV Digital went into liquidation in
2002. The re-launch of DTTV as the free
Freeview service has been a success in introducing people to multichannel digital TV and seems not to have adversely affected the growth of cable and satellite subscribers.
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.
United States
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.
Unlike
North America, many cable operators in
Europe have already introduced telephone services, which operate just like existing fixed line operators.
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 56k 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.
Another service being added to many cable systems is
cable telephone service. 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 most 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.
