Wikipedia

Satellite television

For the television channel "Satellite Television" launched in 1982, seeSky One § History.

Satellite televisionis a service that deliverstelevisionprogramming to viewers by relaying it from acommunications satelliteorbiting the Earth directly to the viewer's location.[1]The signals are received via an outdoorparabolic antennacommonly referred to as asatellite dishand alow-noise block downconverter.

A number of satellite dishes
Diagram showing how modern satellite television works

A satellite receiver decodes the desiredtelevision programfor viewing on atelevision set.Receivers can be externalset-top boxes,or a built-intelevision tuner.Satellite television provides a wide range of channels and services. It is usually the only television available in many remote geographic areas withoutterrestrial televisionorcable televisionservice. Different receivers are required for the two types. Some transmissions and channels are unencrypted and thereforefree-to-air,while many other channels are transmitted with encryption.Free-to-viewchannels are encrypted but not charged-for, whilepay televisionrequires the viewer to subscribe and pay a monthly fee to receive the programming.[2]

Modern systems signals are relayed from a communications satellite on theX band(8–12 GHz) orKuband(12–18 GHz) frequencies requiring only a small dish less than a meter in diameter.[3]The first satellite TV systems were a now-obsolete type known astelevision receive-only.These systems received weaker analog signals transmitted in theC-band(4–8 GHz) fromFSStype satellites, requiring the use of large 2–3-meter dishes. Consequently, these systems were nicknamed "big dish" systems, and were more expensive and less popular.[4]Early systems usedanalog signals,but modern ones usedigital signalswhich allow transmission of the modern television standardhigh-definition television,due to the significantly improvedspectral efficiencyof digital broadcasting. As of 2022,Star One D2from Brazil is the only remaining satellite broadcasting in analog signals.[5][6]

Technology

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The satellites used for broadcasting television are usually in ageostationary orbit36,000 km (22,000 mi) above the earth'sequator.The advantage of this orbit is that the satellite's orbital period equals the rotation rate of the Earth, so the satellite appears at a fixed position in the sky. Thus the satellite dish antenna which receives the signal can be aimed permanently at the location of the satellite and does not have to track a moving satellite. A few systems instead use a highly elliptical orbit withinclinationof +/−63.4 degrees and an orbital period of about twelve hours, known as aMolniya orbit.

Satellite television, like other communications relayed by satellite, starts with a transmitting antenna located at anuplinkfacility.[7]Uplink satellite dishes are very large, as much as 9 to 12 meters (30 to 40 feet) in diameter.[7]The increased diameter results in more accurate aiming and increased signal strength at the satellite.[7]The uplink dish is pointed toward a specific satellite and the uplinked signals are transmitted within a specific frequency range, so as to be received by one of thetransponderstuned to that frequency range aboard that satellite.[8]The transponder re-transmits the signals back to Earth at a different frequency (a process known as translation, used to avoid interference with the uplink signal), typically in the 10.7-12.7 GHz band, but some still transmit in theC-band(4–8 GHz),Ku-band(12–18 GHz), or both.[7]The leg of the signal path from the satellite to the receiving Earth station is called the downlink.[9]

A typical satellite has up to 32Ku-bandor 24C-bandtransponders, or more forKu/Chybrid satellites. Typical transponders each have a bandwidth between 27 and 50 MHz. Each geostationaryC-bandsatellite needs to be spaced 2° longitude from the next satellite to avoid interference; forKuthe spacing can be 1°. This means that there is an upper limit of 360/2 = 180 geostationaryC-bandsatellites or 360/1 = 360 geostationaryKu-bandsatellites.C-bandtransmission is susceptible to terrestrial interference whileKu-bandtransmission is affected byrain(as water is an excellent absorber of microwaves at this particular frequency). The latter is even more adversely affected by ice crystals in thunder clouds. On occasion,sun outagewill occur when the sun lines up directly behind the geostationary satellite to which the receiving antenna is pointed.[10]

The downlink satellite signal, quite weak after traveling the great distance (seepath loss), is collected with aparabolicreceiving dish, which reflects the weak signal to the dish's focal point.[11]Mounted on brackets at the dish's focal point is a device called afeedhornor collector.[12]The feedhorn is a section ofwaveguidewith a flared front-end that gathers the signals at or near the focal point and conducts them to a probe or pickup connected to alow-noise block downconverter(LNB).[13]The LNB amplifies the signals anddownconvertsthem to a lower block ofintermediate frequencies(IF), usually in theL-band.[13]

The originalC-bandsatellite television systems used alow-noise amplifier(LNA) connected to the feedhorn at the focal point of the dish.[14]The amplified signal, still at the higher microwave frequencies, had to be fed via very expensive low-loss 50-ohm impedancegas filled hardlinecoaxial cablewith relatively complexN-connectorsto an indoor receiver or, in other designs, a downconverter (a mixer and a voltage-tuned oscillator with some filter circuitry) for downconversion to an intermediate frequency.[14]The channel selection was controlled typically by a voltage tuned oscillator with the tuning voltage being fed via a separate cable to the headend, but this design evolved.[14]

Designs formicrostrip-based converters foramateur radiofrequencies were adapted for the 4 GHzC-band.[15]Central to these designs was concept of block downconversion of a range of frequencies to a lower, more easily handled IF.[15]

Back view of a linear polarisedLNB.

The advantages of using an LNB are that cheaper cable can be used to connect the indoor receiver to the satellite television dish and LNB, and that the technology for handling the signal atL-bandand UHF was far cheaper than that for handling the signal atC-bandfrequencies.[16]The shift to cheaper technology from the hardline and N-connectors of the earlyC-bandsystems to the cheaper and simpler 75-ohm cable andF-connectorsallowed the early satellite television receivers to use, what were in reality, modifiedUHFtelevision tuners which selected the satellite television channel for down conversion to a lowerintermediate frequencycentered on 70 MHz, where it was demodulated.[16]This shift allowed the satellite televisionDTHindustry to change from being a largely hobbyist one where only small numbers of systems costing thousands of US dollars were built, to a far more commercial one of mass production.[16]

In the United States, service providers use theintermediate frequencyranges of 950–2150 MHz to carry the signal from the LNBF at the dish down to the receiver. This allows for the transmission of UHF signals along the same span of coaxial wire at the same time. In some applications (DirecTVAU9-S and AT-9), ranges of the lowerB-band[ambiguous]and 2250–3000 MHz, are used. Newer LNBFs in use by DirecTV, called SWM (Single Wire Multiswitch), are used to implementsingle cable distributionand use a wider frequency range of 2–2150 MHz.[citation needed]

The satellite receiver orset-top boxdemodulates and converts the signals to the desired form (outputs for television, audio, data, etc.).[17]Often, the receiver includes the capability to selectivelyunscrambleordecryptthe received signal to provide premium services to some subscribers; the receiver is then called anintegrated receiver/decoderor IRD.[18]Low-loss cable (e.g.RG-6,RG-11,etc.) is used to connect the receiver to the LNBF or LNB.[13]RG-59is not recommended for this application as it is not technically designed to carry frequencies above 950 MHz, but may work in some circumstances, depending on the quality of the coaxial wire, signal levels, cable length, etc.[13]

A practical problem relating to home satellite reception is that an LNB can basically only handle a single receiver.[19]This is because the LNB is translating two differentcircular polarizations(right-hand and left-hand) and, in the case of K-band, two different frequency bands (lower and upper) to the same frequency range on the cable.[19]Depending on which frequency and polarization a transponder is using, the satellite receiver has to switch the LNB into one of four different modes in order to receive a specific "channel".[19]This is handled by the receiver using theDiSEqCprotocol to control the LNB mode.[19]If several satellite receivers are to be attached to a single dish, a so-calledmultiswitchwill have to be used in conjunction with a special type of LNB.[19]There are also LNBs available with a multi-switch already integrated.[19]This problem becomes more complicated when several receivers are to use several dishes (or several LNBs mounted in a single dish) pointing to different satellites.[19]

A common solution for consumers wanting to access multiple satellites is to deploy a single dish with a single LNB and to rotate the dish using an electric motor. The axis of rotation has to be set up in the north–south direction and, depending on the geographical location of the dish, have a specific vertical tilt. Set up properly the motorized dish when turned will sweep across all possible positions for satellites lined up along thegeostationary orbitdirectly above the equator. The dish will then be capable of receiving any geostationary satellite that is visible at the specific location, i.e. that is above the horizon. TheDiSEqCprotocol has been extended to encompass commands for steering dish rotors.[citation needed]

There are five major components in a satellite system: the programming source, the broadcast center, the satellite, thesatellite dish,and thereceiver."Direct broadcast" satellites used for transmission of satellite television signals are generally ingeostationary orbit37,000 km (23,000 mi) above the earth'sequator.[20]The reason for using this orbit is that the satellite circles the Earth at the same rate as the Earth rotates, so the satellite appears at a fixed point in the sky. Thus satellite dishes can be aimed permanently at that point, and do not need a tracking system to turn to follow a moving satellite. A few satellite TV systems use satellites in aMolniya orbit,a highlyellipticalorbit withinclinationof +/-63.4 degrees and an orbital period of about twelve hours.

Satellite television, like other communications relayed by satellite, starts with a transmitting antenna located at anuplinkfacility.[20]Uplink facilities transmit the signal to the satellite over a narrow beam ofmicrowaves,typically in theC-bandfrequency range due to its resistance torain fade.[20]Uplink satellite dishes are very large, often as much as 9 to 12 metres (30 to 40 feet) in diameter[20]to achieve accurate aiming and increased signal strength at the satellite, to improve reliability.[20]The uplink dish is pointed toward a specific satellite and the uplinked signals are transmitted within a specific frequency range, so as to be received by one of thetransponderstuned to that frequency range aboard that satellite.[20]The transponder then converts the signals toKuband,a process known as "translation," and transmits them back to earth to be received by home satellite stations.[20]

A DTH Satellite dish from India.

The downlinked satellite signal, weaker after traveling the great distance (seepath loss), is collected by using a rooftopparabolicreceiving dish ( "satellite dish"), which reflects the weak signal to the dish's focal point.[21]Mounted on brackets at the dish'sfocal pointis afeedhorn[21]which passes the signals through awaveguideto a device called alow-noise block converter(LNB) or low noise converter (LNC) attached to the horn.[21]The LNB amplifies the weak signals, filters the block of frequencies in which the satellite television signals are transmitted, and converts the block of frequencies to a lower frequency range in theL-bandrange.[21]The signal is then passed through acoaxial cableinto the residence to the satellite television receiver, aset-top boxnext to the television.

The reason for using the LNB to do the frequency translation at the dish is so that the signal can be carried into the residence using cheapcoaxial cable.To transport the signal into the house at its originalKubandmicrowavefrequency would require an expensivewaveguide,a metal pipe to carry the radio waves.[16]The cable connecting the receiver to the LNB are of the low loss typeRG-6,quad shield RG-6, or RG-11.[22]RG-59is not recommended for this application as it is not technically designed to carry frequencies above 950 MHz, but will work in many circumstances, depending on the quality of the coaxial wire.[22]The shift to more affordable technology from the 50ohm impedance cable andN-connectorsof the earlyC-bandsystems to the cheaper 75ohm technology andF-connectorsallowed the early satellite television receivers to use, what were in reality, modifiedUHFtelevision tuners which selected the satellite television channel for down conversion to another lowerintermediate frequencycentered on 70 MHz where it was demodulated.[16]

An LNB can only handle a single receiver.[19]This is due to the fact that the LNB is mapping two different circular polarisations – right hand and left hand – and in the case of theKu-bandtwo different reception bands – lower and upper – to one and the same frequency band on the cable, and is a practical problem for home satellite reception.[19]Depending on which frequency a transponder is transmitting at and on what polarisation it is using, the satellite receiver has to switch the LNB into one of four different modes in order to receive a specific desired program on a specific transponder.[19]The receiver uses theDiSEqCprotocol to control the LNB mode, which handles this.[19]If several satellite receivers are to be attached to a single dish a so-calledmultiswitchmust be used in conjunction with a special type of LNB.[19]There are also LNBs available with a multi-switch already integrated.[19]This problem becomes more complicated when several receivers use several dishes or several LNBs mounted in a single dish are aimed at different satellites.[19]

Theset-top boxselects the channel desired by the user by filtering that channel from the multiple channels received from the satellite, converts the signal to a lowerintermediate frequency,decryptstheencryptedsignal,demodulatesthe radio signal and sends the resulting video signal to the television through a cable.[22]To decrypt the signal the receiver box must be "activated" by the satellite company. If the customer fails to pay his monthly bill the box is "deactivated" by a signal from the company, and the system will not work until the company reactivates it. Some receivers are capable ofdecryptingthe received signal itself. These receivers are calledintegrated receiver/decodersor IRDs.[22]

Analog television which was distributed via satellite was usually sent scrambled or unscrambled inNTSC,PAL,orSECAMtelevision broadcast standards. The analog signal isfrequency modulatedand is converted from an FM signal to what is referred to asbaseband.This baseband comprises the video signal and the audio subcarrier(s). The audio subcarrier is further demodulated to provide a raw audio signal.

Later signals were digitized television signals or multiplex of signals, typicallyQPSK.In general, digital television, including that transmitted via satellites, is based on open standards such asMPEGandDVB-S/DVB-S2orISDB-S.[citation needed]

Theconditional accessencryption/scrambling methods includeNDS,BISS,Conax,Digicipher,Irdeto,Cryptoworks,DG Crypt,Beta digital,SECA Mediaguard,Logiways,Nagravision,PowerVu,Viaccess,Videocipher,andVideoGuard.Many conditional access systems have been compromised.

Sun outage

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An event calledsun outageoccurs when the sun lines up directly behind the satellite in the field of view of the receiving satellite dish.[23]This happens for about a 10-minute period daily around midday, twice every year for a two-week period in the spring and fall around theequinox.During this period, the sun is within themain lobeof the dish's reception pattern, so the strong microwavenoiseemitted by the sun on the same frequencies used by the satellite's transponders drowns out reception.[23]

Uses

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Direct-to-home and direct broadcast satellite

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DBS satellite dishes installed on an apartment complex.

Direct-to-home(DTH) can either refer to the communications satellites themselves that deliver service or the actual television service. Most satellite television customers in developed television markets get their programming through adirect broadcast satellite(DBS) provider.[24]Signals are transmitted usingKuband(12 to 18 GHz) and are completely digital which means it has high picture and stereo sound quality.[3]

Programming for satellite television channels comes from multiple sources and may include live studio feeds.[25]The broadcast center assembles and packages programming into channels for transmission and, where necessary, encrypts the channels. The signal is then sent to theuplink[26]where it is transmitted to the satellite. With some broadcast centers, the studios, administration and up-link are all part of the same campus.[27]The satellite thentranslatesand broadcasts the channels.[28]

Most systems use theDVB-Sstandard for transmission.[24]Withpay televisionservices, the data stream is encrypted and requires proprietary reception equipment. While the underlying reception technology is similar, the pay television technology is proprietary, often consisting of aconditional-access moduleandsmart card.This measure assures satellite television providers that only authorized, payingsubscribershave access to pay television content but at the same time can allowfree-to-airchannels to be viewed even by the people with standard equipment available in the market.

Some countries operate satellite television services which can be received for free, without paying a subscription fee. This is calledfree-to-airsatellite television.Germanyis likely the leader in free-to-air with approximately 250 digital channels (including 83HDTVchannels and various regional channels) broadcast from theAstra 19.2°Esatellite constellation.[29]These are not marketed as a DBS service, but are received in approximately 18 million homes, as well as in any home using theSky Deutschlandcommercial DBS system. All German analogue satellite broadcasts ceased on 30 April 2012.[30][31]

TheUnited Kingdomhas approximately 160 digital channels (including the regional variations ofBBCchannels,ITVchannels,Channel 4andChannel 5) that are broadcast without encryption from theAstra 28.2°Esatellite constellation, and receivable on anyDVB-Sreceiver (aDVB-S2receiver is required for certain high definition television services). Most of these channels are included within theSkyEPG,and an increasing number within theFreesatEPG.

India's national broadcaster,Doordarshan,promotes a free-to-air DBS package as "DD Free Dish",which is provided as in-fill for the country's terrestrial transmission network. It is broadcast fromGSAT-15at 93.5°E and contains about 80 FTA channels.

While originally launched asbackhaulfor theirdigital terrestrial televisionservice, a large number of French channels are free-to-air on satellites at 5°W, and have recently been announced as being official in-fill for the DTT network.

In North America (United States,CanadaandMexico) there are over 80 FTA digital channels available onGalaxy 19(with the majority being ethnic or religious in nature). Other FTA satellites includeAMC-4,AMC-6,Galaxy 18,andSatmex5. A company calledGloryStarpromotes FTA religious broadcasters onGalaxy 19.

Satellite TV has seen a decline in consumers since the 2010s due to thecord-cuttingtrend where people are shifting towards internet-basedstreaming televisionand freeover-the-air television.[32]

Television receive-only

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Main article:Television receive-only
A C-bandAndrew Corporationsatellite dish used by TVRO systems.

The termtelevision receive-only,or TVRO, arose during the early days of satellite television reception to differentiate it from commercial satellite television uplink and downlink operations (transmit and receive). This was the primary method of satellite television transmissions before the satellite television industry shifted, with the launch of higher powered DBS satellites in the early 1990s which transmitted their signals on theKubandfrequencies.[4][33]Satellite television channels at that time were intended to be used bycable televisionnetworks rather than received by home viewers.[34]Early satellite television receiver systems were largely constructed by hobbyists and engineers. These early TVRO systems operated mainly on theC-bandfrequencies and the dishes required were large; typically over 3 meters (10 ft) in diameter.[35]Consequently, TVRO is often referred to as "big dish" or "Big Ugly Dish" (BUD) satellite television.

TVRO systems were designed to receive analog and digitalsatellitefeeds of both television or audio from bothC-bandandKu-bandtranspondersonFSS-type satellites.[36][37]The higher frequencyKu-bandsystems tend to resemble DBS systems and can use a smaller dish antenna because of the higher power transmissions and greater antenna gain. 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 aC-band-only setup rather than aKuband-only setup. Additional receiver boxes allow for different types of digital satellite signal reception, such as DVB/MPEG-2 and4DTV.

The narrow beam width of a normal parabolic satellite antenna means it can only receive signals from a single satellite at a time.[38]Simulsator the Vertex-RSI TORUS, is a quasi-parabolic satellite earthstation antenna that is capable of receiving satellite transmissions from 35 or moreC- andKu-bandsatellites simultaneously.[39]

History

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Early history

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In 1945 Britishscience fictionwriterArthur C. Clarkeproposed a worldwide communications system which would function by means of three satellites equally spaced apart in earth orbit.[40][41]This was published in the October 1945 issue of theWireless Worldmagazine and won him theFranklin Institute'sStuart Ballantine Medalin 1963.[42][43]

The first public satellite television signals fromEuropetoNorth Americawere relayed via theTelstarsatellite over theAtlanticocean on 23 July 1962, although a test broadcast had taken place almost two weeks earlier on 11 July.[44]The signals were received and broadcast in North American and European countries and watched by over 100 million.[44]Launched in 1962, theRelay 1satellite was the first satellite to transmit television signals from the US to Japan.[45]The firstgeosynchronouscommunication satellite,Syncom 2,was launched on 26 July 1963.[46]

The world's first commercial communications satellite, calledIntelsat Iand nicknamed "Early Bird", was launched into geosynchronous orbit on April 6, 1965.[47]The first nationalnetworkof television satellites, calledOrbita,was created by theSoviet Unionin October 1967, and was based on the principle of using the highly ellipticalMolniyasatellite for rebroadcasting and delivering of televisionsignalsto grounddownlinkstations.[48]The first commercial North American satellite to carry television transmissions wasCanada's geostationaryAnik 1,which was launched on 9 November 1972.[49]ATS-6,the world's first experimental educational anddirect broadcast satellite(DBS), was launched on 30 May 1974.[50]It transmitted at 860 MHz using wideband FM modulation and had two sound channels. The transmissions were focused on the Indian subcontinent but experimenters were able to receive the signal in Western Europe using home constructed equipment that drew on UHF television design techniques already in use.[51]

The first in a series of Soviet geostationary satellites to carrydirect-to-hometelevision,Ekran1, was launched on 26 October 1976.[52]It used a 714 MHz UHF downlink frequency so that the transmissions could be received with existingUHF television technologyrather than microwave technology.[53]

Beginning of the satellite TV industry, 1976–1980

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The satellite television industry developed first in the US from thecable televisionindustry as communication satellites were being used to distribute television programming to remotecable television headends.Home Box Office(HBO),Turner Broadcasting System(TBS), andChristian Broadcasting Network(CBN, laterThe Family Channel) were among the first to use satellite television to deliver programming.Taylor HowardofSan Andreas,California,became the first person to receiveC-bandsatellite signals with his home-built system in 1976.[54]

In the US,PBS,a non-profit public broadcasting service, began to distribute its television programming by satellite in 1978.[55]

In 1979, Soviet engineers developed the Moskva (orMoscow) system of broadcasting and delivering of TV signals via satellites. They launched theGorizontcommunication satellites later that same year. These satellites usedgeostationary orbits.[56]They were equipped with powerful on-board transponders, so the size of receiving parabolic antennas of downlink stations was reduced to 4 and 2.5 metres.[56]On October 18, 1979, theFederal Communications Commission(FCC) began allowing people to have home satellite earth stations without a federal government license.[57]The front cover of the 1979Neiman-MarcusChristmas catalogue featured the first home satellite TV stations on sale for $36,500.[58]The dishes were nearly 20 feet (6.1 m) in diameter[59]and were remote controlled.[60]The price went down by half soon after that, but there were only eight more channels.[61]The Society for Private and Commercial Earth Stations (SPACE), an organisation which represented consumers and satellite TV system owners, was established in 1980.[62]

Early satellite television systems were not very popular due to their expense and large dish size.[63]The satellite television dishes of the systems in the late 1970s and early 1980s were 10 to 16 feet (3.0 to 4.9 m) in diameter,[64]made offibreglassor solidaluminumorsteel,[65]and in the United States cost more than $5,000, sometimes as much as $10,000.[66]Programming sent from ground stations was relayed from eighteen satellites ingeostationary orbitlocated 22,300 miles (35,900 km) above the Earth.[67][68]

TVRO/C-band satellite era, 1980–1986

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Further information:Television receive-only

By 1980, satellite television was well established in theUSand Europe. On 26 April 1982, the first satellite channel in the UK, Satellite Television Ltd. (laterSky One), was launched.[69]Its signals were transmitted from theESA'sOrbital Test Satellites.[69]Between 1981 and 1985, TVRO systems' sales rates increased as prices fell. Advances in receiver technology and the use ofgallium arsenideFETtechnology enabled the use of smaller dishes. Five hundred thousand systems, some costing as little as $2000, were sold in the US in 1984.[66][70]Dishes pointing to one satellite were even cheaper.[71]People in areas without local broadcast stations or cable television service could obtain good-quality reception with no monthly fees.[66][68]The large dishes were a subject of much consternation, as many people considered themeyesores,and in the US most condominiums, neighborhoods, and other homeowner associations tightly restricted their use, except in areas where such restrictions were illegal.[4]These restrictions were altered in 1986 when the Federal Communications Commission ruled all of them illegal.[63]A municipality could require a property owner to relocate the dish if it violated other zoning restrictions, such as a setback requirement, but could not outlaw their use.[63]The necessity of these restrictions would slowly decline as the dishes got smaller.[63]

Originally, all channels were broadcastin the clear(ITC) because the equipment necessary to receive the programming was too expensive for consumers. With the growing number of TVRO systems, the program providers and broadcasters had toscrambletheir signal and develop subscription systems.

In October 1984, theU.S. Congresspassed theCable Communications Policy Act of 1984,which gave those using TVRO systems the right to receive signals for free unless they were scrambled, and required those who did scramble to make their signals available for a reasonable fee.[68][72]Since cable channels could prevent reception by big dishes, other companies had an incentive to offer competition.[73]In January 1986,HBObegan using the now-obsoleteVideoCipherII system toencrypt their channels.[64]Other channels used less securetelevision encryptionsystems. The scrambling of HBO was met with much protest from owners of big-dish systems, most of which had no other option at the time for receiving such channels, claiming that clear signals from cable channels would be difficult to receive.[74]Eventually HBO allowed dish owners to subscribe directly to their service for $12.95 per month, a price equal to or higher than what cable subscribers were paying, and required adescramblerto be purchased for $395.[74]This led to theattackon HBO's transponderGalaxy 1byJohn R. MacDougallin April 1986.[74]One by one, all commercial channels followed HBO's lead and began scrambling their channels.[75]TheSatellite Broadcasting and Communications Association(SBCA) was founded on December 2, 1986, as the result of a merger between SPACE and the Direct Broadcast Satellite Association (DBSA).[70]

Videocipher II used analog scrambling on its video signal andData Encryption Standard–based encryption on its audio signal. VideoCipher II was defeated, and there was ablack marketfor descrambler devices which were initially sold as "test" devices.[75]

1987 to present

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By 1987, nine channels were scrambled, but 99 others were available free-to-air.[72]While HBO initially charged a monthly fee of $19.95, soon it became possible to unscramble all channels for $200 a year.[72]Dish sales went down from 600,000 in 1985 to 350,000 in 1986, but pay television services were seeing dishes as something positive since some people would never have cable service, and the industry was starting to recover as a result.[72]Scrambling also led to the development ofpay-per-viewevents.[72]On November 1, 1988,NBCbegan scrambling itsC-bandsignal but left itsKubandsignal unencrypted in order for affiliates to not lose viewers who could not see their advertising.[76]Most of the two million satellite dish users in the United States still usedC-band.[76]ABCandCBSwere considering scrambling, though CBS was reluctant due to the number of people unable to receive localnetwork affiliates.[76]The piracy on satellite television networks in the US led to the introduction of theCable Television Consumer Protection and Competition Act of 1992.This legislation enabled anyone caught engaging in signal theft to be fined up to $50,000 and to be sentenced to a maximum of two years in prison.[77]A repeat offender can be fined up to $100,000 and be imprisoned for up to five years.[77]

Satellite television had also developed inEuropebut it initially used low power communication satellites and it required dish sizes of over 1.7 metres. On 11 December 1988, however,LuxembourglaunchedAstra 1A,the first satellite to provide medium power satellite coverage to Western Europe.[78]This was one of the first medium-powered satellites, transmitting signals inKubandand allowing reception with small dishes (90 cm).[78]The launch of Astra beat the winner of the UK's state Direct Broadcast Satellite licence holder,British Satellite Broadcasting,to the market.

Commercial satellite broadcasts have existed in Japan since 1992 led byNHKwhich is influential in the development of regulations and has access to government funding for research. Their entry into the market was protected by theMinistry of Posts and Telecommunications(MPT) resulting in theWOWOWchannel that is encrypted and can be accessed from NHK dishes with a decoder.[79]

In the US in the early 1990s, four large cable companies launchedPrimeStar,a direct broadcasting company using medium power satellites. The relatively strong transmissions allowed the use of smaller (90 cm) dishes. Its popularity declined with the 1994 launch of theHughesDirecTVandDish Networksatellite television systems.

Digitalsatellite broadcasts began in 1994 in the United States throughDirecTVusing theDSSformat. They were launched (with theDVB-Sstandard) inSouth Africa,Middle East,North AfricaandAsia-Pacificin 1994 and 1995, and in 1996 and 1997 in European countries including France, Germany, Spain, Portugal, Italy and the Netherlands, as well as Japan, North America and Latin America. Digital DVB-S broadcasts in the United Kingdom and Ireland started in 1998. Japan started broadcasting with theISDB-Sstandard in 2000.

On March 4, 1996, EchoStar introduced Digital Sky Highway (Dish Network) using the EchoStar 1 satellite.[80]EchoStar launched a second satellite in September 1996 to increase the number of channels available on Dish Network to 170.[80]These systems provided better pictures and stereo sound on 150–200 video and audio channels, and allowed small dishes to be used. This greatly reduced the popularity of TVRO systems. In the mid-1990s, channels began moving their broadcasts todigital televisiontransmission using theDigiCipherconditional accesssystem.[81]

In addition to encryption, the widespread availability, in the US, of DBS services such as PrimeStar and DirecTV had been reducing the popularity of TVRO systems since the early 1990s. Signals from DBS satellites (operating in the more recentKuband) are higher in both frequency and power (due to improvements in thesolar panelsandenergy efficiencyof modern satellites) and therefore require much smaller dishes thanC-band,and thedigital modulationmethods now used require lesssignal strengthat the receiver than analog modulation methods.[82]Each satellite also can carry up to 32 transponders in theKuband,but only 24 in theC band,and severaldigital subchannelscan bemultiplexed(MCPC) or carried separately (SCPC) on a single transponder.[83]Advances innoise reductiondue to improved microwave technology andsemiconductormaterials have also had an effect.[83]However, one consequence of the higher frequencies used for DBS services israin fadewhere viewers lose signal during a heavy downpour.C-bandsatellite television signals are less prone to rain fade.[84]

In a return to the older (but proven) technologies of satellite communication, the current DBS-based satellite providers in the US (Dish Network and DirecTV) are now utilizing additional capacity on theKu-bandtransponders of existing FSS-class satellites, in addition to the capacity on their own existing fleets of DBS satellites in orbit. This was done in order to provide more channel capacity for their systems, as required by the increasing number of High-Definition and simulcast local station channels. The reception of the channels carried on theKu-bandFSS satellite's respective transponders has been achieved by both DirecTV & Dish Network issuing to their subscribers dishes twice as big in diameter (36 ") than the previous 18" (& 20 "for the Dish Network" Dish500 ") dishes the services used initially, equipped with 2 circular-polarized LNBFs (for reception of 2 native DBS satellites of the provider, 1 per LNBF), and 1 standard linear-polarized LNB for reception of channels from an FSS-type satellite. These newer DBS/FSS-hybrid dishes, marketed by DirecTV and Dish Network as the" SlimLine "and"SuperDish"models respectively, are now the current standard for both providers, with their original 18" /20 "single or dual LNBF dishes either now obsolete, or only used for program packages, separate channels, or services only broadcast over the providers' DBS satellites.

On 29 November 1999 US PresidentBill Clintonsigned theSatellite Home Viewer Improvement Act(SHVIA).[85]The act allowed Americans to receive local broadcast signals via direct broadcast satellite systems for the first time.[85]

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The1963 Radio Regulationsof theInternational Telecommunication Union(ITU) defined a "broadcasting satellite service" as a "space service in which signals transmitted or retransmitted by space stations, or transmitted by reflection from objects in orbit around theEarth,are intended for direct reception by the general public. "[86]

In the 1970s some states grew concerned that external broadcasting could alter the cultural or political identity of a state leading to theNew World Information and Communication Order(NWICO) proposal. However, satellite broadcasts can not be restricted on a per-state basis due to the limitations of the technology. Around the time theMacBride reportwas released, satellite broadcasting was being discussed at theUN Committee on the Peaceful Uses of Outer Space(COPUOS) where most of the members supported prior consent restrictions for broadcasting in their territories, but some argued this would violatefreedom of information.The parties were unable to reach a consensus on this and in 1982 submittedUNGA Res 37/92( "DBS Principles" ) to theUN General Assemblywhich was adopted by a majority vote, however, most States capable of DBS voted against it. The "DBS Principles" resolution is generally regarded as ineffective.[87]

See also

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References

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  1. ^ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.39, definition:Broadcasting-satellite service
  2. ^Campbell, Dennis; Cotter, Susan (1998).Copyright Infringement.Kluwer Law International.ISBN90-247-3002-3.Retrieved18 September2014.
  3. ^ab"Frequency letter bands".Microwaves101.com.25 April 2008. Archived fromthe originalon 14 July 2014.Retrieved30 January2014.
  4. ^abc"Installing Consumer-Owned Antennas and Satellite Dishes".FCC.Archivedfrom the original on 2011-04-29.Retrieved2008-11-21.
  5. ^"Star One D2 at 70.0°W".lyngsat.com.Archivedfrom the original on 2023-12-10.Retrieved2023-12-10.
  6. ^"Lista completa de frequências".Portal BSD(in Portuguese).Archivedfrom the original on 2023-12-10.Retrieved2023-12-10.
  7. ^abcdPattan 1993,p. 207.
  8. ^Pattan 1993,p. 330.
  9. ^Pattan 1993,p. 327.
  10. ^Tirro 1993,p. 279.
  11. ^Minoli 2009,p. 60.
  12. ^Minoli 2009,p. 27.
  13. ^abcdMinoli 2009,p. 194.
  14. ^abc"Europe's Best Kept Secret".Electronics World + Wireless World.95.Reed Business Publishing: 60–62. 1985.Retrieved28 July2014.
  15. ^ab"Microstrip Impedance Program".Ham Radio Magazine.17.Communications Technology, Incorporated: 84. 1984.Retrieved28 July2014.
  16. ^abcde"Microwave Journal International".Microwave Journal International.43(10–12).Horizon House:26–28. 2000.Retrieved28 July2014.
  17. ^Dodd 2002,p. 308.
  18. ^Dodd 2002,p. 72.
  19. ^abcdefghijklmnFox, Barry (1995)."Leaky dishes drown out terrestrial TV".New Scientist.145.Reed Business Information:19–22.Retrieved28 July2014.
  20. ^abcdefgPattan, Bruno (31 March 1993).Satellite Systems:Principles and Technologies.Berlin: Springer Science & Business Media.ISBN9780442013578.Retrieved29 July2014.
  21. ^abcdMinoli, Daniel (3 February 2009).Satellite Systems Engineering in an IPv6 Environment.Boca Raton, Florida:CRC Press.ISBN978-1420078688.Retrieved29 July2014.
  22. ^abcdDodd, Annabel Z. (2002).The Essential Guide to Telecommunications(5th ed.).Upper Saddle River, New Jersey:Prentice Hall.pp. 307–10.ISBN0130649074.Retrieved29 July2014.
  23. ^abTirró, S. (30 June 1993).Satellite Communication Systems Design.Berlin:Springer Science & Business Media. pp. 279–80.ISBN978-0306441479.Retrieved29 July2014.
  24. ^abAntipolis, Sophia (September 1997).Digital Video Broadcasting (DVB); Implementation of Binary Phase Shift Keying (BPSK) modulation in DVB satellite transmission systems(PDF)(Report).European Telecommunications Standards Institute.pp. 1–7. TR 101 198.Archived(PDF)from the original on 13 December 2016.Retrieved20 July2014.
  25. ^"JEDI Innovation report".Archivedfrom the original on 2014-07-27.Retrieved2014-07-22.
  26. ^Bruce R. Elbert (2008). "9 Earth Stations and Network Technology".Introduction To Satellite Communications.Artech House.ISBN9781596932111.
  27. ^"Space TV".Popular Mechanics.171(8). Hearst Magazines: 57–60. August 1994.ISSN0032-4558.
  28. ^"Intelsat New Media Brochure"(PDF).Archived(PDF)from the original on 2014-04-07.Retrieved2014-07-21.
  29. ^"Satellitenfernsehen in Deutschland"[Satellite TV in Germany].kabelfernsehen-kabelanschluss.de(in German).Archivedfrom the original on 15 April 2016.Retrieved5 April2016.
  30. ^"ZDFneo, 3sat, BR, NDR, SWR, WDR, Phoenix, KiKa starten HD Kanäle"[ZDFneo, 3sat, BR, NDR, SWR, WDR, Phoenix, KiKa launch HD channels].kabel-internet-telefon.de(in German). 13 March 2012.Archivedfrom the original on 27 February 2019.Retrieved8 April2012.
  31. ^"HDTV: Neue HD-Kanäle von ARD und ZDF ab 30. April 2012"[HDTV: New HD channels from ARD and ZDF after 30 April 2012].T-online.de(in German). 20 January 2012.Archivedfrom the original on 27 December 2012.Retrieved8 April2012.
  32. ^Newman, Jared (2019-02-13)."Cable and satellite TV companies need a miracle to save them from cord-cutting".Fast Company.Archivedfrom the original on 2020-02-26.Retrieved2019-07-05.
  33. ^James, Meg.NBC tacks on Telemundo oversight to Gaspin's tasksArchived2020-02-26 at theWayback Machine.Los Angeles Times, July 26, 2007. Retrieved on May 14, 2010.
  34. ^"Satellite Communications Training from NRI!".Popular Science.228.Bonnier Corporation. February 1986.Retrieved16 December2014.
  35. ^Prentiss 1989,p. 274.
  36. ^Prentiss 1989,p. 246.
  37. ^Prentiss 1989,p. 1.
  38. ^Prentiss 1989,p. 293.
  39. ^"Sensing SATCOM Success Is New Simulsat From ATCi".Satnews.1 November 2009.Archivedfrom the original on 16 December 2014.Retrieved16 December2014.
  40. ^"The Arthur C. Clarke Foundation".Archived fromthe originalon July 25, 2011.Retrieved2016-06-01.
  41. ^Campbell, Richard; Martin, Christopher R.; Fabos, Bettina (23 February 2011).Media and Culture: An Introduction to Mass Communication.London, UK:Macmillan Publishers.p. 152.ISBN978-1457628313.Retrieved15 August2014.
  42. ^"The 1945 Proposal by Arthur C. Clarke for Geostationary Satellite Communications".lakdiva.org.Archivedfrom the original on 2020-03-08.Retrieved2019-12-06.
  43. ^Wireless technologies and the national information infrastructure.DIANE Publishing. September 1995. p. 138.ISBN0160481805.Archivedfrom the original on 2 May 2024.Retrieved15 August2014.
  44. ^abKlein, Christopher (23 July 2012)."The Birth of Satellite TV, 50 Years Ago".History.com.History Channel.Archivedfrom the original on 25 October 2014.Retrieved5 June2014.
  45. ^"Relay 1".NASA.gov.NASA.Archivedfrom the original on 2019-07-14.Retrieved2014-07-20.
  46. ^Darcey, RJ (16 August 2013)."Syncom 2".NASA.gov.NASA.Archivedfrom the original on 14 July 2019.Retrieved5 June2014.
  47. ^"Encyclopedia Astronautica - Intelsat I".Archived fromthe originalon 16 January 2010.Retrieved5 April2010.
  48. ^"Soviet-bloc Research in Geophysics, Astronomy, and Space"(Press release). Springfield Virginia: U.S. Joint Publications Research Service. 1970. p. 60.Archivedfrom the original on 2 May 2024.Retrieved16 December2014.
  49. ^Robertson, Lloyd (1972-11-09)."Anik A1 launching: bridging the gap".CBC English TV.Archivedfrom the original on 2007-12-19.Retrieved2007-01-25.
  50. ^Ezell, Linda N. (22 January 2010)."NASA - ATS".Nasa.gov.NASA.Archivedfrom the original on 6 April 2013.Retrieved1 July2014.
  51. ^Long Distance Television Reception (TV-DX) For the Enthusiast, Roger W. Bunney,ISBN0900162716
  52. ^"Ekran".Astronautix.com.Astronautix. 2007. Archived fromthe originalon 12 November 2013.Retrieved1 July2014.
  53. ^"Ekran (11F647)".space.skyrocket.de.Archivedfrom the original on 2020-01-02.Retrieved2019-12-06.
  54. ^Feder, Barnaby J. (15 November 2002)."Taylor Howard, 70, Pioneer In Satellite TV for the Home".New York Times.Archivedfrom the original on 2 May 2024.Retrieved19 July2014.
  55. ^Public Service Broadcasting in the Age of Globalization, Editors: Indrajit Banerjee, Kalinga Seneviratne.ISBN9789814136013
  56. ^abWade, Mark."Gorizont".Encyclopedia Astronautica. Archived fromthe originalon 2008-06-17.Retrieved2008-06-29.
  57. ^"The" Glory Days "of Satellite".Archived fromthe originalon March 3, 2014.
  58. ^Browne, Ray (2001).The Guide to United States Popular Culture.Madison, Wisconsin:Popular Press. p. 706.ISBN9780879728212.Archivedfrom the original on 2 May 2024.Retrieved1 July2014.
  59. ^Giarrusso, Michael (28 July 1996)."Tiny Satellite Dishes Sprout in Rural Areas".Los Angeles Times.Los Angeles.Archivedfrom the original on 15 July 2014.Retrieved1 July2014.
  60. ^Keating, Stephen (1999)."Stealing Free TV, Part 2".The Denver Post.Denver, CO:The Denver Post.Archivedfrom the original on 14 July 2014.Retrieved3 July2014.
  61. ^Stein, Joe (1989-01-24). "Whatta dish: Home satellite reception a TV turn-on".Evening Tribune.p. C-8.
  62. ^"Earth Station Is Very Popular Dish".Reading Eagle.Kansas City, Missouri.21 December 1980.Archivedfrom the original on 13 August 2021.Retrieved21 July2014.
  63. ^abcdBrooks, Andree (10 October 1993)."Old satellite dish restrictions under fire New laws urged for smaller models".The Baltimore Sun.Baltimore, MD:The Baltimore Sun.Archivedfrom the original on 14 July 2014.Retrieved1 July2014.
  64. ^abNye, Doug (14 January 1990)."SATELLITE DISHES SURVIVE GREAT SCRAMBLE OF 1980S".Deseret News.Salt Lake City:Deseret News.Archivedfrom the original on 7 October 2017.Retrieved30 June2014.
  65. ^Ku-Band Satellite TV: Theory, Installation and Repair.Frank Baylin et al.ISBN9780917893148.
  66. ^abcStecklow, Steve (1984-07-07). "America's Favorite Dish".The Miami Herald.Knight-Ridder News Service.p. 1C.
  67. ^Reibstein, Larry (1981-09-27). "Watching TV Via Satellite Is Their Dish".The Philadelphia Inquirer.p. E01.
  68. ^abcDawidziak, Mark (1984-12-30). "Satellite TV Dishes Getting Good Reception".Akron Beacon-Journal.p. F-1.
  69. ^ab"Broadband Cable 10th Anniversary".TinyPic.Archivedfrom the original on 6 March 2014.Retrieved5 May2013.
  70. ^ab"Industry History".sbca.com.Satellite Broadcasting and Communications Association. 2014. Archived fromthe originalon 19 February 2014.Retrieved5 June2014.
  71. ^Stecklow, Steve (1984-10-25). "Research Needed in Buying Dish: High Cost Is Important Consideration for Consumer".Wichita Eagle.Knight-Ridder News Service. p. 6C.
  72. ^abcdeTakiff, Jonathan (1987-05-22)."Satellite TV Skies Brighten As War With Programmers Ends".Chicago Tribune.Knight-Ridder Newspapers.Archivedfrom the original on 2014-04-15.Retrieved2014-04-10.
  73. ^Wolf, Ron (1985-01-20). "Direct-Broadcast TV Is Still Not Turned On".The Philadelphia Inquirer.p. C01.
  74. ^abcLyman, Rick; Borowski, Neill (April 29, 1986)."On The Trail Of 'Captain Midnight'".Philly.Archivedfrom the original on May 21, 2014.RetrievedMay 20,2014.
  75. ^abParadise, Paul R. (1 January 1999).Trademark Counterfeiting, Product Piracy, and the Billion Dollar Threat to the U.S. Economy.Westport, Connecticut:Greenwood Publishing Group.p. 147.ISBN1567202500.Archivedfrom the original on 2 May 2024.Retrieved3 July2014.
  76. ^abc"Scrambled NBC Bad News for Satellite Pirates".The San Francisco Chronicle.United Press International. 1988-11-03. p. E3.
  77. ^abCable Television Consumer Protection and Competition Act of 1992(PDF)(1460, STATUTE-106-Pg1460.pdf). 8 October 1992.Retrieved3 July2014.
  78. ^ab"ASTRA 1A Satellite details 1988-109B NORAD 19688".N2YO. 9 July 2014.Archivedfrom the original on 30 June 2014.Retrieved12 July2014.
  79. ^Buckley, Sandra (2002).Encyclopedia of Contemporary Japanese Culture.Routledge.
  80. ^abGrant, August E. (2010).Communication Technology Update(10th ed.).Taylor & Francis.p. 87.ISBN978-0-240-81475-9.
  81. ^Bell-Jones, Robin; Berbner, Jochen; Chai, Jianfeng; Farstad, Thomas; Pham, Minh (June 2001)."High Technology Strategy and Entrepreneurship"(PDF).INSEAD Journal.Fontainebleau:INSEAD. Archived fromthe original(PDF)on 2014-07-24.
  82. ^Mirabito, M., and Morgenstern, B. (2004).Satellites: Operations and Applications: The New Communication Technologies(fifth edition). Burlington: Focal Press.
  83. ^abKhaplil, Vidya R.; Bhalachandra, Anjali R. (April 2008).Advances in Recent Trends in Communication and Networks.New Delhi:Allied Publishers. p. 119.ISBN978-1466651708.Archivedfrom the original on 2 May 2024.Retrieved16 July2014.
  84. ^"Rain fade: satellite TV signal and adverse weather".Dish-cable.com.2010.Archivedfrom the original on 15 June 2014.Retrieved16 July2014.
  85. ^abSatellite Home Viewer Improvement Act(00-96). 29 November 1999.Retrieved30 July2014.
  86. ^Gotlieb, A.E. (1969). "Direct Satellite Broadcasting: A Case Study in the Development of the Law of Space Communications".The Canadian Yearbook of International Law 1969.7:33–60.doi:10.1017/S0069005800011826.S2CID169142288.
  87. ^Francis Lyall (2019). "satellite Broadcasting".UN Committee on the Peaceful Uses of Outer Space.
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