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Brief Introduction of Cable Television: Definition, History and Development | Soukacatv.com


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07.12.2018 05:21:46 - Cable television is a way of letting people watch television without having to get signals from an antenna. The television signals are brought to the television through a coaxial cable.

(live-PR.com) - Cable television is a way of letting people watch television without having to get signals from an antenna. The television signals are brought to the television through a coaxial cable. People usually have to pay to subscribe to cable television. With cable television, people can watch hundreds of television channels carrying many television shows. Usually some of these are television

 

stations and others are made for the cable companies.

Cable TV is provided by many carriers in across with world. Some of those carriers in the United States are: AT&T U-Verse, CableVision, Comcast, Cox Communications, SuddenLink, Time Warner Cable and Verizon

Another method of subscription television is by Satellite television, especially in places where cable TV is not available.

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Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fiber-optic cables. This contrasts with broadcast television (also known as terrestrial television), in which the television signal is transmitted over the air by radio wavesand received by a television antenna attached to the television; or satellite television, in which the television signal is transmitted by a communications satellite orbiting the Earth and received by a satellite dish on the roof. FM radio programming, high-speed Internet, telephone services, and similar non-television services may also be provided through these cables. Analog television was standard in the 20th century, but since the 2000s, cable systems have been upgraded to digital cable operation.

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 Sky, as well as via IPTV providers such as Verizon FIOS and AT&T U-verse 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, Cinemax, MTV, Cartoon Network, AXN, E!, Fox Life, Discovery Channel, Canal+, Eurosport, Fox Sports, Disney Channel, Nickelodeon, CNN International, ESPN, GMA Pinoy TV and The Filipino Channel.

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 TV 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 for radio are even older as radio programming was distributed by cable in some European cities as far back as 1924.

History in North America
Cable television began in the United States as a commercial business in 1950, although there were small-scale systems by hobbyists in the 1940s.

The early systems simply received weak (broadcast) channels, amplified them, and sent them over unshielded wires to the subscribers, limited to a community or to adjacent communities. The receiving antenna would be higher than any individual subscriber could afford, thus bringing in stronger signals; in hilly or mountainous terrain it would be placed at a high elevation.

At the outset, cable systems only served smaller communities without television stations of their own, and which could not easily receive signals from stations in cities because of distance or hilly terrain. In Canada, however, communities with their own signals were fertile cable markets, as viewers wanted to receive American signals. Rarely, as in the college town of Alfred, New York, U.S. cable systems retransmitted Canadian channels.

Although early (VHF) television receivers could receive 12 channels (2-13), the maximum number of channels that could be broadcast in one city was 7: channels 2, 4, either 5 or 6, 7, 9, 11 and 13, as receivers at the time were unable to receive strong (local) signals on adjacent channels without distortion. (There were frequency gaps between 4 and 5, and between 6 and 7, which allowed both to be used in the same city).

As equipment improved, all twelve channels could be utilized, except where a local VHF television station broadcast. Local broadcast channels were not usable for signals deemed to be priority, but technology allowed low-priority signals to be placed on such channels by synchronizing their blanking intervals. Similarly, a local VHF station could not be carried on its broadcast channel as the signals would arrive at the TV set slightly separated in time, causing "ghosting".

The bandwidth of the amplifiers also was limited, meaning frequencies over 250 MHz were difficult to transmit to distant portions of the coaxial network, and UHF channels could not be used at all. To expand beyond 12 channels, non-standard "midband" channels had to be used, located between the FM band and Channel 7, or "superband" beyond Channel 13 up to about 300 MHz; these channels initially were only accessible using separate tuner boxes that sent the chosen channel into the TV set on Channel 2, 3 or 4.

Before being added to the cable box itself, these midband channels were used for early incarnations of pay TV, e.g. The Z Channel(Los Angeles) and HBO but transmitted in the clear i.e. not scrambled as standard TV sets of the period could not pick up the signal nor could the average consumer `de-tune' the normal stations to be able to receive it.

Once tuners that could receive select mid-band and super-band channels began to be incorporated into standard television sets, broadcasters were forced to either install scrambling circuitry or move these signals further out of the range of reception for early cable-ready TVs and VCRs. However, once all 181 allocated cable channels had been incorporated, premium broadcasters were left with no choice but to scramble.

Unfortunately for pay-TV operators, the descrambling circuitry was often published in electronics hobby magazines such as Popular Science and Popular Electronics allowing anybody with anything more than a rudimentary knowledge of broadcast electronics to be able to build their own and receive the programming without cost.

Later, the cable operators began to carry FM radio stations, and encouraged subscribers to connect their FM stereo sets to cable. Before stereo and bilingual TV sound became common, Pay-TV channel sound was added to the FM stereo cable line-ups. About this time, operators expanded beyond the 12-channel dial to use the "midband" and "superband" VHF channels adjacent to the "high band" 7-13 of North American television frequencies. Some operators as in Cornwall, Ontario, used a dual distribution network with Channels 2-13 on each of the two cables.

During the 1980s, United States regulations not unlike public, educational, and government access (PEG) created the beginning of cable-originated live television programming. As cable penetration increased, numerous cable-only TV stations were launched, many with their own news bureaus that could provide more immediate and more localized content than that provided by the nearest network newscast.

Such stations may use similar on-air branding as that used by the nearby broadcast network affiliate, but the fact that these stations do not broadcast over the air and are not regulated by the FCC, their call signs are meaningless. These stations evolved partially into today's over-the-air digital subchannels, where a main broadcast TV station e.g. NBS 37* would – in the case of no local CNB or ABS station being available – rebroadcast the programming from a nearby affiliate but fill in with its own news and other community programming to suit its own locale. Many live local programs with local interests were subsequently created all over the United States in most major television markets in the early 1980s.

This evolved into today's many cable-only broadcasts of diverse programming, including cable-only produced television moviesand miniseries. Cable specialty channels, starting with channels oriented to show movies and large sporting or performance events, diversified further, and "narrowcasting" became common. By the late 1980s, cable-only signals outnumbered broadcast signals on cable systems, some of which by this time had expanded beyond 35 channels. By the mid-1980s in Canada, cable operators were allowed by the regulators to enter into distribution contracts with cable networks on their own.

By the 1990s, tiers became common, with customers able to subscribe to different tiers to obtain different selections of additional channels above the basic selection. By subscribing to additional tiers, customers could get specialty channels, movie channels, and foreign channels. Large cable companies used addressable descramblers to limit access to premium channels for customers not subscribing to higher tiers, however the above magazines often published workarounds for that technology as well.

During the 1990s, the pressure to accommodate the growing array of offerings resulted in digital transmission that made more efficient use of the VHF signal capacity; fibre optics was common to carry signals into areas near the home, where coax could carry higher frequencies over the short remaining distance. Although for a time in the 1980s and 1990s, television receivers and VCRs were equipped to receive the mid-band and super-band channels. Due to the fact that the descrambling circuitry was for a time present in these tuners, depriving the cable operator of much of their revenue, such cable-ready tuners are rarely used now - requiring a return to the set-top boxes used from the 1970s onward.

The conversion to digital broadcasting has put all signals - broadcast and cable - into digital form, rendering analog cable television service mostly obsolete, functional in an ever-dwindling supply of select markets. Analog television sets are still[when?]accommodated, but their tuners are mostly obsolete, oftentimes dependent entirely on the set-top box.

Deployments by continent
Cable television is mostly available in North America, Europe, Australia, South Asia and East Asia, and less so in South America and the Middle East. Cable television has had little success in Africa, as it is not cost-effective to lay cables in sparsely populated areas. So-called "wireless cable" or microwave-based systems are used instead.

Cable television, generally, any system that distributes television signals by means of coaxial or fibre-optic cables. The term also includes systems that distribute signals solely via satellite. Cable-television systems originated in the United States in the late 1940s and were designed to improve reception of commercial network broadcasts in remote and hilly areas. During the 1960s they were introduced in many large metropolitan areas where local television reception is degraded by the reflection of signals from tall buildings. Commonly known as community antenna television (CATV), these cable systems use a “community antenna” to receive broadcast signals (often from communications satellites), which they then retransmit via cables to homes and establishments in the local area subscribing to the service. Subscribers pay a specified monthly service charge in addition to an initial installation fee.

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Source: From Wikipedia, the free encyclopedia


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