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Satellite television

From Academic Kids

Satellite television is television delivered by way of orbiting communications satellites located 37,000 km (22,300 miles) above the earth's surface. The first satellite television signal was relayed from Europe to the Telstar satellite over North America in 1962. The first domestic North American satellite to carry television was Canada's Anik 1, which was launched in 1973.

Satellite television, like other communications relayed by satellite, starts with a transmitting antenna located at an uplink facility. Uplink satellite dishes are directed toward the satellite that their signals will be transmitted to, and are very large, as much as 9 to 12 meters (30 to 40 feet) in diameter. The increased diameter results in more accurate positioning and improved signal reception at the satellite. The signal is transmitted to devices located on-board the satellite called transponders, which retransmit the satellite signal back towards the Earth at a different frequency.

The satellite signal, quite weak after travelling through space, is collected by a parabolic receiving dish, which reflects the weak signal to the dish's focal point and is received, down-converted to a lower frequency band and amplified by a device called a low-noise block downconverter, or LNB. Direct broadcast satellite dishes use an LNBF, which integrates the feedhorn with the LNB.

A new form of satellite antenna, which does not use a directed parabolic dish and can be used on a mobile platform such as a vehicle, was recently announced by the University of Waterloo. [1] (http://newsrelease.uwaterloo.ca/news.php?id=4072)

The signal, now amplified, travels to a satellite receiver box through coaxial cable (RG-6 or RG-10; cannot be standard RG-59) and is converted by a local oscillator to the L-band range of frequencies (approximately). Special on-board electronics in the receiver box help tune the signal and then convert it to a frequency that a standard television can use.

There are two primary types of satellite television distribution: direct broadcast satellite (DBS) and television receive-only (TVRO).

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Direct broadcast via satellite

Direct broadcast satellite, (DBS) also known as "direct to home" is a relatively recent development in the world of television distribution. "Direct broadcast satellite" can either refer to the communications satellites themselves that deliver DBS service or the actual television service. DBS systems are commonly referred to as "minidish" systems. DBS uses the upper portion of the Ku band.

Modified DBS systems can also run on C Band satellites and have been used by some networks in the past to get around legislation by some countries against reception of Ku Band transmissions.

DBS systems are generally based on open standards such as MPEG2 DVB-S but may include proprietary encryption and decryption/reception equipment, most often in the form of a television set-top signal descrambling box called an IRD (Integrated Receiver Decoder). This measure assures satellite television providers that only authorised, paying subscribers have access to Pay TV content but at the same time can allow free to air channels to be viewed even by the people with standard equipment available in the market.

Satellite television by continent and country

United Kingdom

The first commercial DBS service, Sky Television, was launched in 1989 and served customers in the United Kingdom, providing 16 analogue TV channels. In the following year BSB was launched, broadcasting five channels in D2Mac format; the two services subsequently merged to form British Sky Broadcasting. In 1994 17% of the group was floated on London and U.S. stock exchanges, and Rupert Murdoch's News Corporation owns a 35% stake.

By 1999, following the launch of several more satellites (at 19.2 degrees east) by SES Astra, the number of channels had increased to around 60 and BSkyB launched the first subscription-based digital television platform in the UK, offering a range of 200 channels broadcast from the Astra satellites at 28.2 degrees east under the brand name Sky Digital. BSkyB's analogue service has now been discontinued, with all customers having been migrated to Sky Digital.

United States

Consumer satellite television reception in the United States began in the early 1980's with the introduction of the first home satellite systems designed for receiving the same TVRO signals used for distribution to cable systems. Early setups were very expensive and large, with 12-foot (3.7m) dishes common. Many were motorized, allowing for reception of multiple satellites, and therefore a greater selection of channels. Originally, all channels were available in the clear, including premium movie services, a major draw and source of growth for the then-burgeoning industry. In 1986, movie channel HBO encrypted their signal, setting a precedent for most other mainstream cable television services. This led to a major decline in the sales of satellite systems. By the early 1990's, the industry recovered as a result of Videocipher decoders being bundled with systems. TVRO systems reached their peak around 1995 before declining as a result of consumer adoption of higher-powered, "small-dish" systems such as DirecTV, Primestar, and the Dish Network. As of May 31, 2005, 215,076 big dishes were still subscribed to pay TV programming 1 (http://skyretailer.com/view.cfm?ReleaseID=688&SearchCriteria=c%2Dband), as opposed to nearly three million at the peak in 1995, although more may be in use solely for free-to-air television reception.

Hughes's DirecTV, the first high-powered DBS system, went online in 1994 and was the first North American DBS service; it is now owned by News Corporation. In 1996, EchoStar's DISH Network went online in the United States and has gone on to similar success as DirecTV's primary competitor. In 2004, Cablevision's Voom service went online, specifically catering to the emerging market of HDTV owners and afficianados, but folded in April 2005, with the service's "exclusive" high-definition channels currently being migrated to the Dish Network system. Commercial DBS services are the primary competition to cable television service, although the two types of service have significantly different regulatory requirements (for example, cable television has public access requirements, and the two types of distribution have different regulations regarding carriage of local stations).

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The majority of ethnic-language broadcasts to North America are carried on Ku-band free-to-air; the largest concentration of ethnic programming is on Intelsat Americas 5 at 97°W. Globecast World TV offers a mix of free and pay-TV ethnic channels in the internationally-standard DVB-S format, as do others. Several US-English language network affiliates (representing CBS, NBC, ABC, PBS, Fox TV, WB, PAX and UPN) are available as free-to-air broadcasts, as are the three US-Spanish language networks (Univisión, Telefutura and Telemundo). The number of free-to-air specialty channels is otherwise rather limited. Specific FTA offerings tend to appear and disappear rather often and typically with little or no notice, although sites such as LyngSat (http://www.lyngsat.com) do track the changing availability of both free and pay channels worldwide.

Canada

In Canada, the two legal DBS services available are Bell Canada's ExpressVu, and StarChoice. The CRTC has refused to license American satellite services, but nonetheless hundreds of thousands (if not millions) of Canadians access or have accessed American services - usually these services have to be billed to an American address and are paid for in U.S. dollars. Whether such activity is grey market or black market is the source of often heated debate between those who would like greater choice and those who argue that the protection of Canadian firms and Canadian culture is more important.

Most recently as of 2004, an October 2004 ruling by judge Danièle Côté of Québec has determined the Canadian radiocommunication act to be in direct violation of the Canadian Charter of Rights and Freedoms; the judgement gave the federal government a one-year deadline to remedy this breach of the Constitution as the fundamental law of the land.

In addition, Canadian satellite providers continue to be plagued by the unquestionably black market devices which "pirate" or "steal" their signals as well as by a number of otherwise completely lawful devices which can be reprogrammed to receive pirate TV.

One cable TV CEO (Karl Péladeau of Québecor, which owns Vidéotron) is on public record as demanding conditions be placed on the CRTC license issued to Bell ExpressVu, due to BEV's reputation for vastly inferior security compared to its cable rivals and Shaw Cable-owned StarChoice.

Although there are no official statistics, the use of American satellite services in Canada appears to be declining as of 2004.

Some would claim that this is probably due to a combination of increasingly aggressive police enforcement and an unfavourable exchange rate between the Canadian and U.S. currencies. As the U.S. dollar has been declining as of 2005 versus other international currencies, the decline in DirecTV viewership in Canada may well be related not to a cost difference as much as to the series of smart card swaps which have rendered the first three generations of DirecTV access cards (F, H and HU) all obsolete.

Australia and New Zealand

Satellite television in Australia has proven to be a far more feasible option than cable television, due to the vast distances between population centres. The first service to come online in Australia was Galaxy Television, which was later taken over by Cable Television giant Foxtel, which now operates both cable and satellite services to all state capital cities and the Southwest. Its main metropolitan rival is Optus Television, while rural areas of the Eastern States are served by Austar. In neighbouring New Zealand, SKY Network Television now offers multichannel digital satellite TV, in addition to its terrestrial UHF service.

Europe

In Europe, DBS satellite services are found mainly on Eutelsat, Hotbird, and Astra, with Canal Digital, Viasat, and UPC being the main providers in Western Europe, Scandinavia, and Central Europe. BSkyB (known as Sky Television) also serves Northern Europe and many channels can be received as far away as Cyprus. The overall market share of DBS satellite services in 2004 was 21.4% of all TV homes, however this highly varies from country to country. For example, in Germany, with many free-to-air TV-stations, DBS market share is almost 40%, and in Belgium and the Netherlands, it's only about 7%, due to the widespread cable networks with exclusive content.

Japan

The two satellite systems in use in Japan are B-SAT and JSAT; the BS digital service uses B-SAT, while SKY PerfecTV! uses JSAT.

India

After more than a decade of debate and controversy, two networks were allowed to start Direct To Home (DTH) services in India, private broadcaster [Zee Network] and state owned broadcaster [Doordarshan] started [Dish TV] and DD Direct+ respectively.

Due to several issues concerning competitors in the Cable TV space, Dish TV has not been able to garner the number of subscribers it had expected to win over from Cable TV because Zee Network's competing broadcasters have refused to allow Dish TV to telecast their channels on the DTH platform. With legislation coming into place and the regulating authority TRAI working on the issue, this is expected to change soon.

Dish TV uses the NSS 6 satellite for telecast.

Latin America

Latin America's main satellite system is SKY Television, which has up to 1 million subscribers in Brazil, Colombia and Mexico. In 2004, DirecTV Latin America was converted to SKY by News Corporation.

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Africa

Multichoice is the satellite for both South Africa and sub-Saharan Africa.

Television receive-only

Television receive-only, or TVRO, refers to satellite television reception equipment that is based primarily on open standards equipment. This contrasts sharply with direct broadcast satellite, which is a completely closed system that uses proprietary reception equipment. TVRO is often referred to as "big dish" satellite television.

TVRO systems are designed to receive analog satellite signals from both C-band and Ku-band satellite television or audio signals. TVRO systems tend to use larger rather than smaller satellite dish antennas, since it is more likely that the owner of a TVRO system would have a C-band-only setup rather than a Ku-band-only setup. Additional receiver boxes allow for different types of digital satellite signal reception, such as DVB/MPEG-2 and 4DTV.

Parabolic Earth Station antennas receive signals from a single satellite at a time. Simulsat is a quasi-parabolic satellite earthstation antenna that is capable of receiving satellite transmissions from 35 or more C and Ku Band satellites simultaneously.

Direct broadcasting satellites which can be received by what are known in Chinese as little ears have had a major role in breaking the government monopoly of information on Mainland China. Although met with frequent and generally unsuccessful efforts to regulate them, satellite dishes are fairly common in urban China. Satellite television has also played an important role in broadcasting to expatriate communities such as Arabs, and overseas Chinese.

See also

External links

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