Sistem Telekomunikasi    
   
Daftar Isi ☛
(Sebelumnya) Cable modemCableCARD (Berikutnya)

Cable television

Coaxial cable is usually used to carry the cable television signal into a residence.

Cable television is a system of distributing television programs to subscribers via radio frequency (RF) signals transmitted through coaxial cables or light pulses through fiber-optic cables. This contrasts with traditional broadcast television (terrestrial 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.

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.

Diagram of a modern hybrid fiber coaxial cable television system. At the regional headend, the TV channels are sent multiplexed on a light beam which travels through optical fiber trunklines, which fan out from distribution hubs to optical nodes in local communities. Here the light signal from the fiber is translated to a radio frequency electrical signal, which is distributed through coaxial cable to individual subscriber homes.

Contents

Receiving cable television

In order to receive cable television at a given location, cable distribution lines must be available on the local utility poles or underground utility lines. Coaxial cable brings the signal to the customer's building through a service drop, an overhead or underground cable. If the subscriber's building does not have a cable service drop, the cable company will install one. The standard cable used in the U.S. is RG-6, which has a 75 ohm impedance, and connects with a type F connector. The cable company's portion of the wiring usually ends at a distribution box on the building exterior, and built-in cable wiring in the walls usually distributes the signal to jacks in different rooms to which televisions are connected. Multiple cables to different rooms are split off the incoming cable with a small device called a splitter.

Most American television sets are cable-ready and have a television tuner capable of receiving older analog cable TV (UK televisions are set up to receive Freeview digital terrestrial broadcasting). The cable from the wall is attached directly to the "Antenna In" connector on the back of the television. To receive newer digital cable, most TVs require a "digital television adapter" (set-top box) called a cable converter box from the cable company, connected between the incoming cable and the TV, that processes digital signals. Most cable systems are required by their franchise agreement to offer some channels, including local broadcast stations, educational, and community access channels (PEG), for a low rate; this is called "Basic Cable".

How it works

In the most common system, multiple television channels (as many as 500) 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, called the headend. Multiple channels are transmitted through the cable by 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 not interfere. At the subscriber's residence, either the subscriber's television or a set-top box provided by the cable company translates the desired channel back to its original frequency (baseband), and it is displayed on the screen. Due to widespread cable theft in earlier analog systems, in modern digital cable systems the signals are encrypted, and the set-top box must be activated by an activation code sent by the cable company before it will function, which is only sent after the subscriber signs up. There are also usually "upstream" channels on the cable, to send data from the customer box to the cable headend, for advanced features such as requesting pay-per-view shows, cable internet access, and cable telephone service. The "downstream" channels occupy a band of frequencies from approximately 50 MHz to 1 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 more.

At the local headend, the feed signals from the individual television channels are received by dish antennas from communication satellites. Additional local channels, such as local broadcast television stations, educational channels from local colleges, and community access channels devoted to local governments (PEG channels) are usually included on the cable. Commercial advertisements for local business are also inserted in the programming at the headend (the individual channels, which are distributed nationally, also have their own nationally oriented commercials).

Hybrid fiber coaxial systems

Modern cable systems are large, with a single network and headend often serving an entire metropolitan area or county. Most systems use hybrid fiber coaxial (HFC) distribution; this means the trunklines that carry the signal from the headend to local neighborhoods are optical fiber to provide greater bandwidth and also extra capacity for future expansion. At the headend the radio frequency electrical signal carrying all the channels is modulated on a light beam and sent through the fiber. The fiber trunkline goes to several distribution hubs, from which multiple fibers fan out to carry the signal to boxes called optical nodes in local communities. At the optical node, the light beam from the fiber is translated back to an electrical signal and carried by coaxial cable distribution lines on utility poles, from which cables branch out to subscriber residences.

Cable television deployments

It is mostly available in North America, Europe, Australia 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 cost-effective to lay cables in sparsely populated areas. So-called "wireless cable" or microwave-based systems are used instead.

Asia and Australia

Australia

Cable television began in the early 1990s in Australia. Several companies appeared including FOXTEL, Galaxy TV, OPTUS TV, Selectv and Austar offering services to homes across the major states of Australia. Services to Tasmania and the Northern Territory took longer to start, not until the mid 2000s when the digital satellite pay television service had picked up momentum and was beginning to be used for metropolitan installs and not just rural installs.

FOXTEL dominates the cable television landscape and is now rebroadcast by Austar (in rural areas) and formerly OPTUS TV, until the latter ceased broadcasting in 2011. Galaxy TV and Selectv likewise no longer operate. The effective FOXTEL monopoly has drawn criticism within Australia for being anti-competitive and inflating prices.

Maldives

There are only two cable TV operators in the country.[citation needed] As the population of the Maldives is separated across around 200 inhabited islands, there is a cable TV operator for nearly every island. MediaNet Pvt. Ltd. is the country's largest cable TV operator, providing state of the art digital service. MediaNet is a Male-based cable TV operator that provides cable and Multichannel Multipoint Distribution Service (MMDS) service to five islands near Male. MediaNet holds a distribution license for 75 channels and distributes channels to nearly all the operators of the country. In Maldives, cable TV subscribers can get most premium channels available in Asia.

Mongolia

There are several cable TV providers in Mongolia. The main three are "SuperVision", "Hiimori" and "Sansar CATV". All three cover approximately 15 national channels and 40 foreign channels, such as CNN, BBC, and NHK. "Sansar" has the biggest network in Ulaanbaatar. SuperVision is the first digital cable television in Mongolia and other CATVs are planning to launch digital cable television with CA systems.

Philippines

“NUVUE”, the first cable television system, was set up in Baguio City spearheaded by American expatriate Russel Swartley in 1969. Popularity of CATV started in the 1980s after the Marcos administration. Cable giant SkyCable started in 1992. Cable providers have grown, and some examples are Destiny, Cablelink, and some regional cable providers. In 2007, SkyCable introduced the DigiBox, a cable TV set-top box that provides a digital television (DTV) signal for higher video quality and prevents illegal cable TV connections. In 2008, SkyCable also broadcast the 37th Ryder Cup in high-definition television (HDTV). In 2009, SkyCable became the first cable TV service provider in the Philippines to broadcast the UAAP Games in HDTV via the new SkyHD Cable TV service.

Turkey

In Turkey, there is a Satellite and Cable TV provider. Türksat A.Ş. 1990's cable TV started in eight cities: İstanbul, Ankara, İzmir, Adana, Bursa, Konya, Kayseri, and Gaziantep. There are 4 main services: Cable TV, wide band Internet, Digital TV, and VOIP.

Europe

Ireland

Main article: Cable Television in Ireland

Cable television is the most common[citation needed] system for distributing multi-channel television in Ireland. With more than 40 years of history and extensive networks of both wired and "wireless" cable, Ireland is amongst the most cabled countries in Europe. Forty percent[1] of Irish homes received cable television in September 2006. The figure dropped slightly in the early years of the 21st century due to the increased popularity of satellite reception, notably Sky, but has stabilized recently.

In the Republic of Ireland, UPC Ireland is by far the largest cable and MMDS operator, owning all of the state's MMDS licenses and almost all of the state's cable TV operators. UPC offers analogue and digital cable television services in cities and towns throughout the country (with the exception of Cork, where the network is digital-only). It offers MMDS services in rural areas. In areas previously served by NTL, the network is digital-only, while Chorus areas still have both analogue and digital services. Other than UPC, the only other operator providing analogue and digital cable is Casey Cablevision, which operates in Dungarvan, County Waterford. There also exists a small number of analogue-only cable networks such as the Longford service Crossan Cable.

United Kingdom

When the infant BBC Television service was started in 1936, Rediffusion, which had supplied cable radio services since 1928, started providing "Pipe TV" to its customers who had difficulties tuning into the weak TV broadcast signal.[2]

Suspended during World War II, the BBC service was re-established in June 1946, and had only one transmitter, at Alexandra Palace, which served the London area. From the end of 1949, new transmitters were steadily opened to serve other major conurbations, and then smaller areas of population. The areas on the fringes of the transmitter coverage provided an opportunity for Rediffusion and other commercial companies to expand cable systems to enlarge the viewing audience for the one BBC television channel which then existed. The first was in Gloucester in 1950[3] and the process gathered pace over the next few years, especially after a second television channel, ITV, was launched in 1955 to compete with BBC. By the late 1970s, two and a half million British homes received their television service via cable.[4]

By law, these cable systems were restricted to the relay of the public broadcast channels, which meant that as the transmitter network became more comprehensive, the incentive to subscribe to cable was reduced and they began to lose customers. In 1982, a radical liberalization of the law on cable was proposed by the Information Technology Advisory Panel,[5] for the sake of promoting a new generation of broadband cable systems leading to the wired society.[6] After setting up and receiving the conclusions of the Hunt Inquiry into Cable Expansion and Broadcasting Policy, the Government decided to proceed with liberalization and two pieces of legislation: the Cable and Broadcasting Act and the Telecommunications Act, were enacted in 1984.

The result was that cable systems were permitted to carry as many new television channels as they liked, as well as providing a telephone service and interactive services of many kinds (as since made familiar by the Internet). To maintain the momentum of the perceived commercial interest in this new investment opportunity, in 1983, the Government itself granted eleven interim franchises for new broadband systems each covering a community of up to around 100,000 homes, but the competitive franchising process was otherwise left to the new regulatory body, the Cable Authority, which took on its powers from January 1, 1985.

The franchising process proceeded steadily, but the actual construction of new systems was slow, as doubts about an adequate payback from the substantial investment persisted. By the end of 1990 almost 15 million homes had been included in franchised areas, but only 828,000 of these had been passed by broadband cable and only 149,000 were actually subscribing.[7] Thereafter, however, construction accelerated and take-up steadily improved.

The first new television channels launched for carriage on cable systems (going live in March 1984) were Sky Channel, Screensport, Music Box and The Movie Channel. Others followed, some were merged or closed down, but the range expanded. A similar flux was seen among the operators of cable systems: franchises were granted to a host of different companies, but a process of consolidation saw the growth of large multiple system operators, until by the early 2000s, virtually the whole industry was in the hands of two companies, NTL and Telewest.

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 March 3, 2006, with the company being named ntl Incorporated. For the time being, the two brand names and services were marketed separately. However, following NTL's acquisition of Virgin Mobile, the NTL and Telewest services were rebranded Virgin Media on February 8, 2007, creating a single cable operator covering more than 95% of the UK cable market.[citation needed]

There are a small number of other surviving cable television companies in the UK outside of NTL including WightFibre (Isle of Wight) and Smallworld Cable (Ayrshire, Carlisle and Lancashire).

Cable TV faces intense competition from BSkyB's Sky 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 (DTT) 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[citation needed] as the DVB-T multiplex owners are finding free-to-air broadcasting more profitable.[citation needed]

Another potential source of competition in the future will be TV over broadband internet connections; this is known as Internet Protocol television (IPTV). Some IPTV services are currently available in London, while services operated in Hull ceased in April 2006.[citation needed] As the speed and availability of broadband connections increase, more TV content can be delivered using protocols such as IPTV. However, its impact on the market is yet to be measured, as is consumer attitude toward watching TV programs on personal computers instead of television sets. At the end of 2006, BT (the UK's former state owned monopoly phone company) started offering BT Vision, which combines the digital free-to-air standard Freeview through an aerial, and on-demand IPTV, delivered over a BT Broadband connection through the Vision set-top box (BT have chosen to deploy Microsoft's Mediaroom platform for this).[citation needed]

Finland

Finland also has a cable television infrastructure, which is also used for cable internet.

Italy

In the 1950s and 1960s the Italian state broadcaster RAI was the only one authorized to broadcast in Italy, hence making RAI a monopolist. That monopoly status was broken in 1971, when Giuseppe Sacchi, a former RAI editor, launched on April 21 that year the first "free" television station in Italy, called Telebiella and based in Biella, which was only possible through a legal loophole in Italian broadcasting law that did not specifically prohibit the existence of cable television. Telebiella and later of such stations provided Italy's first cable TV services free from the influence of the Italian state. However, these early cable TV stations, which operated as pirate broadcasters in a sense were soon heavily stifled by the Italian government and most were forced to shut down. Later the Italian government introduced laws to regulate and allow for cable television, albeit with heavy restrictions: only one cable system for every city and only one TV channel for each system.

Only in the 1990s did a nationwide cable TV system was developed, first by Telecom Italia and later by FASTWEB. In 2001 TV di Fastweb became the first commercial cable TV platform in Italy, however, after just over a decade in operation TV di Fastweb shut down in November 2012 due to competition from other similar services such as Sky Italia and Mediaset Premium as well as internet video-on-demand services such as Hulu.

North America

Canada

Further information: Multichannel television in Canada

In 1949, Broadcast Relay Service began negotiations for the implementation of what was to be the first large scale cable TV system in North America. The development of the system relied on reaching agreement with Quebec Hydro-Electric Commission to utilise their existing network of power poles supplying power to the Montreal Metro area. Initial discussions began with a meeting with Montreal City Council on June 21, 1949. After many months of negotiation, agreement was reached between Hydro Quebec and Rediffusion on February 28, 1950 for an initial 5 year period. The Rediffusion cable system was operational in 1952 and eventually supplied 80,000 homes in Montreal Quebec. Cable television in Canada began in 1952 with community antenna connections in Vancouver and London, Ontario; which city is first is not clear. Initially, the systems brought American stations to viewers in Canada who had no Canadian stations to watch; broadcast television, though begun late in 1952 in Toronto and Montreal, did not reach a majority of cities until 1954.

In time, cable television was widely established to carry available Canadian stations as well as import American stations, which constituted the vast majority of signals on systems (usually only one or two Canadian stations, while some systems had duplicate or even triplicate coverage of American networks). During the 1970s, a growing number of Canadian stations pushed American channels off the systems, forcing several to expand beyond the original 12-channel system configurations. At the same time, the advent of fibre-optic technology enabled companies to extend their systems to nearby towns and villages that by themselves were not viable cable television markets.

United States

Main article: Cable television in the United States

Cable television in the United States is a common form of television delivery, generally by subscription. Cable television first became available in the United States in 1948, with subscription services in 1949. Data by SNL Kagan shows that as of 2006 about 58.4% of all United States homes subscribe to basic cable television services. Most cable viewers in the US are in the suburbs and tend to be middle class;[8] cable television is less common in low income, inner city, and rural areas.[8]

Cable television franchise fees stem from a community's basic right to charge for use of the property it owns. The cable television franchise fees represent part of the compensation a community receives in exchange for the cable operator's occupation and the right-of-way use of public property. A franchise fee is not a tax; it is a rental charge.

South America

Dominican Republic

Cable television in the Dominican Republic is provided by a variety of companies. These companies offer both English- and Spanish-language television, plus a range of channels in other languages, high definition channels, pay-per-view movies and events, sports packages and premium movie channels such as HBO, Playboy TV, Cinecanal, etc. Also, the channels are from not only the Dominican Republic, but also the United States and Europe. In the Dominican Republic television spectrum, there are 46 VHF, UHF, and free-to-air (FTA) channels. The free of charge channels programming consists mainly of locally produced entertainment shows, news, and comedy shows; and foreign sit-coms, soap operas, movies, cartoons, and sports programs.

The main service provider in the Dominican Republic is Telecable from Tricom. Aster is concentrated in Santo Domingo, but is expanding its service throughout the Dominican Republic. There are also new companies using new technologies that are expanding quickly such as Claro TV (IPTV), Wind Telecom (MMDS) and SKY (Satellite TV).

Panama

Panamanian company Rexa started Cable TV deployment in 1983 to Panama City. In other regions they also had local cable companies. Rexa's successor, Cableonda, was dominant throughout the 1990s, and expanded to Chiriqui Province. Since 2000 actually the most important are: Cable Onda (40% share), Cable and Wireless (started on late 2009) and CTV.[citation needed]

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 cable internet, cable telephony and wireless services, using both unlicensed and licensed spectrum.

Broadband internet access 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 telephone 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, Australia 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 plain old telephone service (POTS)) to the company's switching center, where it is connected to the public switched telephone network (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 (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 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 Voice over Internet Protocol (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 Internet Protocol (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, telephone and Internet access is commonly called triple play regardless of whether CATV or telcos offer it.

More recently, several US cable operators have begun offering wireless services to their subscribers. Most notably was the September 2008 launch of Optimum Wi-Fi by Cablevision. This service is made available, at no additional cost, to Optimum Broadband subscribers, and is available at over 14,000 locations across Long Island, NY, parts of NJ and CT. Cablevision has reported a double digit reduction in subscriber churn since launching Optimum Wi-Fi, even as Verizon has rolled out FiOS, a competitive residential broadband service in the Cablevision footprint. Other Tier 1 cable operators, including Comcast, have announced trials of a similar service in sections of the US Northeast.

History and beginnings of cable TV-originated live programs

During the 1980s, mandated regulations not unlike public, educational, and government access (PEG) channels created the beginning of the cable-originated live television program that evolved into what is known today in the 2010s where many cable networks provide live cable-only broadcasts of many varieties, cable-only produced television movies, and miniseries. Various live local programs with local interests were rapidly being created all over the United States in most major television markets in the early 1980s.

With the development of the internet, by the late 1990s and early 2000, much of that regulation had been replaced where newer industry technologies developed, offering viewers alternate choices for local events and programming leading to what is today, that being Digital Cable, Internet, and Phone being offered to consumers, bundled, by 2010.

See also

  • AllVid
  • CableCARD
  • DVB-C
  • Multichannel video programming distributor
  • North American cable television frequencies
  • Private cable operator
  • QAM (television)
  • Switched Video
  • Tru2way

Notes

  1. ^ "Commission for Communications Regulation". Comreg.ie. Retrieved 2012-02-12. 
  2. ^ Writer Russ J Graham EMAIL MORE ARTICLES WEBSITE. "A short history of Rediffusion by Russ J Graham". Transdiffusion.org. Retrieved 2012-02-12. 
  3. ^ "The Michael Aldrich Archive - Cable Systems". Aldricharchive.com. Retrieved 2012-02-14. 
  4. ^ 1982 Aldrich MJ co-author Cable Systems p18 HMSO London ISBN 0-11-630821-4
  5. ^ "The Michael Aldrich Archive - The Cable Story". Aldricharchive.com. Retrieved 2012-02-14. 
  6. ^ 1982 Aldrich MJ co-author Cable Systems HMSO London ISBN 0-11-630821-4
  7. ^ Cable Authority, Final Report and Accounts 1990
  8. ^ a b "Chart close-up from SNL Kagan Cable Subscription Data Contradicts FCC Chairman Kevin Martin". Marketingcharts.com. 2012-01-29. Retrieved 2012-02-12. 

References

External links

(Sebelumnya) Cable modemCableCARD (Berikutnya)