Internet, TV, Cable TV, & Satellite TV Service Providers
An Internet service provider (ISP) is an organization that provides services for accessing, using, the Internet. Internet service providers may be organized in various forms, such as commercial, community-owned, non-profit, or otherwise privately owned.
Television is a telecommunication medium used for transmitting sound with moving images in monochrome(black-and-white), or in color, and in two or three dimensions. It can refer to a television set, a television program, or the medium of television transmission. Television is a mass medium, for entertainment,education, news and advertising.
Television became available in crude experimental forms in the late 1920s. After World War II, an improved form became popular in the United States and Britain, and television sets became commonplace in homes, businesses, and institutions. During the 1950s, television was the primary medium for influencing public opinion. In the mid-1960s, color broadcasting was introduced in the US and most other developed countries. The availability of storage media such as VHS tape (1976), DVDs (1997), and high-definition Blu-ray Discs (2006) enabled viewers to watch recorded material such as movies. At the end of the first decade of the 2000s, digital television transmissions greatly increased in popularity. Another development was the move from standard-definition television (SDTV) (576i, with 576 interlaced lines of resolution and 480i) to high-definition television (HDTV), which provides a resolution that is substantially higher. HDTV may be transmitted in various formats: 1080p, 1080i and 720p. Since 2010, with the invention of smart television,Internet television has increased the availability of television programs and movies via the Internet through services such as Netflix, iPlayer, Hulu, Roku andChromecast.
In 2013, 79% of the world’s households owned a television set. The replacement of early bulky, high-voltage cathode ray tube (CRT) screen displays with compact, energy-efficient, flat-panel alternative technologies such as plasma displays, LCDs (both fluorescent-backlit and LED), and OLED displays was a hardware revolution that began with computer monitors in the late 1990s. Most TV sets sold in the 2000s were flat-panel, mainly LEDs. Major manufacturers announced the discontinuation of CRT, DLP, plasma, and even fluorescent-backlit LCDs by the mid-2010s. LEDs are expected to be replaced gradually by OLEDs in the near future. Also, major manufacturers have announced that they will increasingly produce smart TV sets in the mid-2010s. Smart TVs with integrated Internet and Web 2.0 functions became the dominant form of television by the late 2010s.
Television signals were initially distributed only as terrestrial television using high-powered radio-frequency transmitters to broadcast the signal to individual television receivers. Alternatively television signals are distributed by co-axial cable or optical fibre, satellite systems and via the Internet. Until the early 2000s, these were transmitted as analog signals but countries started switching to digital, this transition is expected to be completed worldwide by late 2010s. A standard television set is composed of multiple internal electronic circuits, including a tuner for receiving and decoding broadcast signals. A visual display devicewhich lacks a tuner is correctly called a video monitor rather than a television.
Cable television is a system of delivering television programming to paying subscribers via radio frequency (RF) signals transmitted through coaxial cables or light pulses through fiber-optic cables. This contrasts with broadcast television, in which the television signal is transmitted over the air by radio waves and received by a television antenna attached to the television. FM radio programming, high-speed Internet, telephone service, and similar non-television services may also be provided through these cables.
A cable channel (sometimes known as a cable network) is a television network available via cable television. When available through satellite television, including direct broadcast satellite providers such as DirecTV, Dish Network and BSkyB, as well as via IPTV, it is referred to as a satellite channel. Alternative terms include non-broadcast channel or programming service, the latter being mainly used in legal contexts. Examples of cable/satellite channels/cable networks available in many countries are HBO, MTV, Cartoon Network, E!, Eurosport and CNN International.
The abbreviation CATV is often used for cable television. It originally stood for Community Access Television or Community Antenna Television, from cable television’s origins in 1948: in areas where over-the-air reception was limited by distance from transmitters or mountainous terrain, large “community antennas” were constructed, and cable was run from them to individual homes. The origins of cable broadcasting are even older as radio programming was distributed by cable in some European cities as far back as 1924.
It is delivering television programming using signals relayed from space radio stations (e.g. DVB satellites). The signals are received via an outdoor parabolic reflector antenna usually referred to as a satellite dish and a low-noise block downconverter(LNB). A satellite receiver then decodes the desired television programme for viewing on a television set. Receivers can be external set-top boxes, or a built-in television tuner. Satellite television provides a wide range of channels and services, especially to geographic areas without terrestrial television or cable television.
The most common method of reception is direct-broadcast satellite television (DBSTV), also known as “direct to home” (DTH). In DBSTV systems, signals are relayed from a direct broadcast satellite on the Ku wavelength and are completely digital. Satellite TV systems formerly used systems known as television receive-only. These systems received analog signals transmitted in the C-band spectrum from FSS type satellites, and required the use of large dishes. Consequently, these systems were nicknamed “big dish” systems, and were more expensive and less popular.
The direct-broadcast satellite television signals were earlier analog signals and later digital signals, both of which require a compatible receiver. Digital signals may include high-definition television (HDTV). Some transmissions and channels are unencrypted and therefore free-to-air or free-to-view, while many other channels are transmitted with encryption (pay television), requiring a subscription.