Do Cable Companies Have To Supply Service Of Networks

Television content transmitted via signals on coaxial cable

A coaxial cable used to bear cable television onto subscribers' premises

A set-top box, an electronic device which cablevision subscribers use to connect the cable indicate to their television sets. Presented unit is a Cisco RNG200N for QAM digital cable idiot box arrangement used in North America.

Cablevision television is a system of delivering idiot box programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with broadcast boob tube (too known every bit terrestrial telly), in which the television signal is transmitted over-the-air by radio waves and received by a television antenna attached to the television; or satellite tv, in which the boob tube bespeak is transmitted over-the-air past radio waves from a communications satellite orbiting the Earth, and received by a satellite dish antenna on the roof. FM radio programming, high-speed Net, phone services, and like not-television services may also exist provided through these cables. Analog television set was standard in the 20th century, just since the 2000s, cable systems have been upgraded to digital cable functioning.

A "cable channel" (sometimes known as a "cable network") is a idiot box network available via cable television set. When bachelor through satellite boob tube, including directly broadcast satellite providers such equally DirecTV or Dish Network, every bit well as via IPTV providers such as Verizon FIOS and U-verse TV, this is referred to as a "satellite channel". Alternative terms include "non-circulate aqueduct" or "programming service", the latter existence mainly used in legal contexts. The abbreviation "CATV" is used in the U.s.a. for cable television receiver and originally stood for Customs Access Television or Customs Antenna Television, from cablevision tv'due south origins in 1948; in areas where over-the-air TV reception was limited by altitude from transmitters or mountainous terrain, large "community antennas" were constructed, and cable was run from them to individual homes.

In 1968 6.4% of Americans had cablevision television. The number increased to 7.5% in 1978. By 1988 52.8% of all households were using cable. The number further increased to 62.iv% in 1994.^[1]

Distribution [edit]

A cable television distribution box (left) in the basement of a building in Frg (Kabel BW network, now Vodafone), with a splitter (right) which supplies the signal to separate cables which go to different rooms

To receive cablevision television at a given location, cable distribution lines must be available on the local utility poles or hugger-mugger utility lines. Coaxial cable brings the signal to the client's edifice through a service drop, an overhead or hugger-mugger cablevision. If the subscriber's building does not have a cablevision service drib, the cablevision company will install one. The standard cable used in the U.S. is RG-vi, which has a 75 ohm impedance, and connects with a type F connector. The cablevision company's portion of the wiring usually ends at a distribution box on the edifice exterior, and built-in cablevision wiring in the walls usually distributes the signal to jacks in different rooms to which televisions are continued. Multiple cables to unlike rooms are split off the incoming cable with a pocket-size device called a splitter. There are 2 standards for cable tv set; older analog cablevision, and newer digital cablevision which can comport information signals used by digital goggle box receivers such as high-definition television (HDTV) equipment. All cable companies in the United States accept switched to or are in the form of switching to digital cable television since it was starting time introduced in the late 1990s.

Well-nigh cable companies require a set-acme box (cable converter box) or a slot on one's Idiot box set for conditional admission module cards^[2] to view their cable channels, even on newer televisions with digital cable QAM tuners, because most digital cable channels are now encrypted, or "scrambled", to reduce cable service theft. A cable from the jack in the wall is fastened to the input of the box, and an output cable from the box is attached to the goggle box, ordinarily the RF-IN or blended input on older TVs. Since the set-elevation box but decodes the single aqueduct that is being watched, each telly in the house requires a separate box. Some unencrypted channels, usually traditional over-the-air broadcast networks, tin be displayed without a receiver box.^[3] The cable company will provide set-top boxes based on the level of service a client purchases, from basic ready-top boxes with a standard-definition pic connected through the standard coaxial connection on the Tv, to high-definition wireless digital video recorder (DVR) receivers connected via HDMI or component. Older analog tv sets are "cable ready" and tin can receive the old analog cablevision without a set up-meridian box. To receive digital cable channels on an analog idiot box set, even unencrypted ones, requires a unlike type of box, a digital television adapter supplied by the cable company or purchased by the subscriber. Another new distribution method that takes advantage of the low cost high quality DVB distribution to residential areas, uses Boob tube gateways to convert the DVB-C, DVB-C2 stream to IP for distribution of Tv over IP network in the abode. Many cable companies offering internet admission through DOCSIS.^[4]

Principle of operation [edit]

Diagram of a modern hybrid cobweb-coaxial cable television organisation. At the regional headend, the Goggle box channels are sent multiplexed on a calorie-free beam which travels through optical cobweb trunklines, which fan out from distribution hubs to optical nodes in local communities. Hither the calorie-free signal from the fiber is translated to a radio frequency electrical signal, which is distributed through coaxial cable to private subscriber homes.

In the most common system, multiple television channels (as many as 500, although this varies depending on the provider'south available aqueduct capacity) are distributed to subscriber residences through a coaxial cable, which comes from a trunkline supported on utility poles originating at the cable company's local distribution facility, chosen the "headend". Many channels tin can exist transmitted through one coaxial cable past a technique called frequency division multiplexing. At the headend, each television channel is translated to a different frequency. By giving each channel a different frequency "slot" on the cable, the separate television signals do non interfere with each other. At an outdoor cablevision box on the subscriber's residence, the visitor's service drib cable is connected to cables distributing the betoken to different rooms in the building. At each idiot box, the subscriber'south television or a set-elevation box provided past the cable company translates the desired aqueduct back to its original frequency (baseband), and information technology is displayed onscreen. Due to widespread cablevision theft in before analog systems, the signals are typically encrypted on modern digital cable systems, and the set-summit box must exist activated by an activation code sent by the cable company before it will office, which is merely sent after the subscriber signs up. If the subscriber fails to pay their neb, the cable company tin can ship a signal to deactivate the subscriber's box, preventing reception.

There are also usually "upstream" channels on the cable to ship information from the customer box to the cable headend, for advanced features such as requesting pay-per-view shows or movies, cable net admission, and cable telephone service. The "downstream" channels occupy a band of frequencies from approximately 50 MHz to one GHz, while the "upstream" channels occupy frequencies of 5 to 42 MHz. Subscribers pay with a monthly fee. Subscribers can choose from several levels of service, with "premium" packages including more channels but costing a higher charge per unit. At the local headend, the feed signals from the private television receiver channels are received by dish antennas from communication satellites. Additional local channels, such as local circulate television stations, educational channels from local colleges, and community access channels devoted to local governments (PEG channels) are usually included on the cable service. Commercial advertisements for local business are also inserted in the programming at the headend (the individual channels, which are distributed nationally, also accept their ain nationally oriented commercials).

Hybrid fiber-coaxial [edit]

Modernistic cable systems are big, with a unmarried network and headend oftentimes serving an unabridged metropolitan area. Most systems employ hybrid cobweb-coaxial (HFC) distribution; this ways the trunklines that carry the signal from the headend to local neighborhoods are optical fiber to provide greater bandwidth and besides extra capacity for future expansion. At the headend, the electrical signal is translated into an optical signal and sent through the fiber. The fiber trunkline goes to several distribution hubs, from which multiple fibers fan out to behave the bespeak to boxes called optical nodes in local communities. At the optical node, the optical signal is translated back into an electrical indicate and carried past coaxial cable distribution lines on utility poles, from which cables branch out to a series of bespeak amplifiers and line extenders. These devices behave the signal to customers via passive RF devices called taps.

History in N America [edit]

Cable television^[v] began in the United States as a commercial business in 1950, although there were pocket-size-scale systems by hobbyists in the 1940s.

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

At the kickoff, cable systems simply served smaller communities without television stations of their own, and which could non easily receive signals from stations in cities because of distance or hilly terrain. In Canada, all the same, communities with their ain signals were fertile cable markets, as viewers wanted to receive American signals. Rarely, as in the college town of Alfred, New York, U.Due south. cable systems retransmitted Canadian channels.

Although early (VHF) television receivers could receive 12 channels (two–xiii), the maximum number of channels that could be circulate in ane city was vii: channels 2, 4, either 5 or 6, 7, 9, 11 and xiii, as receivers at the time were unable to receive strong (local) signals on adjacent channels without distortion. (At that place were frequency gaps between 4 and 5, and between 6 and 7, which allowed both to be used in the aforementioned metropolis).

As equipment improved, all twelve channels could be utilized, except where a local VHF television station circulate. Local circulate channels were non usable for signals deemed to be a priority, only technology immune low-priority signals to be placed on such channels by synchronizing their blanking intervals. TVs were unable to reconcile these blanking intervals and the slight changes due to travel through a medium, causing ghosting. The bandwidth of the amplifiers also was limited, meaning frequencies over 250 MHz were difficult to transmit to afar portions of the coaxial network, and UHF channels could not be used at all. To aggrandize beyond 12 channels, non-standard "midband" channels had to be used, located between the FM band and Channel seven, or "superband" beyond Channel 13 upwards to about 300 MHz; these channels initially were merely accessible using separate tuner boxes that sent the chosen channel into the Television set attack Channel ii, three or iv.^{[ commendation needed ]} Initially, UHF broadcast stations were at a disadvantage because the standard Television set sets in use at the fourth dimension were unable to receive their channels. Around 1966 the FCC mandated that all TV sets sold later a certain date were required to have the capability of receiving UHF channels.

Earlier being added to the cable box itself, these midband channels were used for early incarnations of pay Television receiver, e.chiliad. The Z Aqueduct (Los Angeles) and HBO but transmitted in the clear i.e. non scrambled as standard TV sets of the period could non pick upwards the signal nor could the average consumer `de-tune' the normal stations to be able to receive information technology.

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 movement these signals farther out of the range of reception for early cable-ready TVs and VCRs. Even so, once consumer sets had the ability to receive all 181 FCC allocated channels, premium broadcasters were left with no choice but to scramble.

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

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

During the 1980s, Us regulations not unlike public, educational, and authorities admission (PEG) created the kickoff of cable-originated live telly 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 past the nearest network newscast.

Such stations may use similar on-air branding as that used by the nearby broadcast network affiliate, merely the fact that these stations practise not circulate 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 Goggle box station east.g. NBS 37* would – in the instance of no local CNB or ABS station being bachelor – rebroadcast the programming from a nearby chapter simply fill in with its own news and other community programming to arrange its own locale. Many live local programs with local interests were after created all over the United states in most major boob tube markets in the early 1980s.

This evolved into today's many cable-but broadcasts of diverse programming, including cable-only produced television movies and miniseries. Cable specialty channels, starting with channels oriented to show movies and large sporting or performance events, diversified farther, and "narrowcasting" became mutual. By the late 1980s, cable-only signals outnumbered broadcast signals on cablevision systems, some of which by this time had expanded beyond 35 channels. Past the mid-1980s in Canada, cable operators were allowed past 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 bones selection. Past subscribing to additional tiers, customers could get specialty channels, picture show channels, and strange channels. Large cablevision companies used addressable descramblers to limit admission 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 than efficient use of the VHF bespeak capacity; fibre optics was common to behave signals into areas near the abode, where coax could deport higher frequencies over the short remaining distance. Although for a fourth dimension 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 cablevision – into digital form, rendering analog cable television service mostly obsolete, functional in an e'er-dwindling supply of select markets. Analog television sets are still^{[ when? ]} accommodated, but their tuners are by and large obsolete, oftentimes dependent entirely on the gear up-summit box.

Deployments past continent [edit]

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 tv has had little success in Africa, as it is not price-effective to lay cables in sparsely populated areas. And then-called "Wireless Cable" microwave-based systems are used instead.

Other cable-based services [edit]

Coaxial cables are capable of bi-directional carriage of signals every bit well every bit the transmission of large amounts of data. Cable boob tube signals utilise only a portion of the bandwidth available over coaxial lines. This leaves plenty of space available for other digital services such every bit cable net, cablevision telephony and wireless services, using both unlicensed and licensed spectrum. Broadband net access is achieved over coaxial cable by using cablevision modems to convert the network data into a type of digital signal that can be transferred over coaxial cable. One problem with some cablevision systems is the older amplifiers placed forth the cable routes are unidirectional thus in order to let for uploading of data the customer would need to use an analog telephone modem to provide for the upstream connection. This express the upstream speed to 31.2 Kbp/due south and prevented the always-on convenience broadband cyberspace typically provides. Many large cable systems take upgraded or are upgrading their equipment to allow for bi-directional signals, thus allowing for greater upload speed and e'er-on convenience, though these upgrades are expensive.

In North America, Australia and Europe, many cable operators accept already introduced cablevision phone service, which operates just like existing fixed line operators. This service involves installing a special telephone interface at the customer'southward 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 plain old phone service (POTS) to the company'south switching center, where it is connected to the public switched telephone network (PSTN). The biggest obstruction to cable telephone service is the need for well-nigh 100% reliable service for emergency calls. One of the standards available for digital cablevision telephony, PacketCable, seems to be the nearly promising and able to work with the quality of service (QOS) demands of traditional analog plain old telephone service (POTS) service. The biggest advantage to digital cable telephone service is similar to the advantage of digital cablevision, namely that information tin 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 Voice over Internet Protocol (VoIP) network providing cheap or unlimited nationwide and international calling. In many cases, digital cable telephone service is separate from cable modem service being offered past many cablevision companies and does not rely on Net Protocol (IP) traffic or the Internet.

Traditional cable television set providers and traditional telecommunications companies increasingly compete in providing vocalism, video and information services to residences. The combination of television receiver, telephone and Internet admission is commonly called "triple play", regardless of whether CATV or telcos offer it.

References [edit]

^ Coopersmith, Jonathan (1998). "Pornography, Engineering science and Progress". Icon. 4: 94–125. JSTOR 23785961.
^ Tynan, Dan (23 May 2007). "New Choices Coming for Cable TV Users". TechHive . Retrieved 3 April 2019.
^ "ClearQAM – What Information technology Is And Why It Matters". eighteen February 2012. Retrieved 19 June 2015.
^ "The Route to Cisco Infinite Broadband" (PDF). Cisco. 2017. Retrieved 28 February 2022.
^ "History of Cable – CCTA". Retrieved 2021-eleven-12 .

External links [edit]

Cable Television at Curlie