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A broadcast relay station, also known as a satellite station, relay transmitter, broadcast translator (U.S.), re-broadcaster (Canada),
repeater In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some ...
(
two-way radio A two-way radio is a radio transceiver (a radio that can both transmit and receive radio waves), which is used for bidirectional person-to-person voice communication with other users with similar radios, in contrast to a broadcast receiver, whi ...
) or complementary station (Mexico), is a broadcast transmitter which repeats (or transponds) the signal of a radio or television station to an area not covered by the originating station. These expand the
broadcast range A broadcast range (also listening range or listening area for radio, or viewing range or viewing area for television) is the service area that a broadcast station or other transmission covers via radio waves (or possibly infrared light, which i ...
of a television or radio station beyond the primary signal's original coverage or improves service in the original coverage area. The stations may be (but are not usually) used to create a
single-frequency network A single-frequency network or SFN is a broadcast network where several transmitters simultaneously send the same signal over the same frequency channel. Analog AM and FM radio broadcast networks as well as digital broadcast networks can operat ...
. They may also be used by an AM or FM radio station to establish a presence on the other band. Relay stations are most commonly established and operated by the same organisations responsible for the originating stations they repeat. Depending on technical and regulatory restrictions, relays may also be set up by unrelated organisations.


Types


Translators

In its simplest form, a broadcast translator is a facility created to receive a terrestrial broadcast over the air on one frequency and rebroadcast the same (or substantially identical) signal on another frequency. These stations are used in television and radio to cover areas (such as valleys or rural villages) which are not adequately covered by a station's main signal. They can also be used to expand market coverage by duplicating programming on another band.


Boosters and distributed transmitters

Relays which broadcast within (or near) the parent station's coverage area on the same channel (or frequency) are known in the U.S. as booster stations. Signals from the stations may interfere with each other without careful antenna design. Radio interference can be avoided by using
atomic time International Atomic Time (abbreviated TAI, from its French name ) is a high-precision atomic coordinate time standard based on the notional passage of proper time on Earth's geoid. TAI is a weighted average of the time kept by over 450 a ...
, obtained from GPS
satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...
s, to synchronize co-channel stations in a
single-frequency network A single-frequency network or SFN is a broadcast network where several transmitters simultaneously send the same signal over the same frequency channel. Analog AM and FM radio broadcast networks as well as digital broadcast networks can operat ...
. Analog television stations cannot have same-channel boosters unless opposite (
perpendicular In geometry, two geometric objects are perpendicular if they intersect at right angles, i.e. at an angle of 90 degrees or π/2 radians. The condition of perpendicularity may be represented graphically using the '' perpendicular symbol'', � ...
) polarization is used, due to video
synchronization Synchronization is the coordination of events to operate a system in unison. For example, the Conductor (music), conductor of an orchestra keeps the orchestra synchronized or ''in time''. Systems that operate with all parts in synchrony are sa ...
issues such as ghosting. In the U.S., no new on-channel UHF signal boosters have been authorized since July 11, 1975. A distributed transmission system (DTS or DTx) uses several medium-power stations (usually digital) on the same frequency to cover a broadcast area, rather than one high-power station with repeaters on a different frequency. Although digital television stations are technically capable of sharing a channel, this is more difficult with the
8VSB 8VSB is the modulation method used for broadcast in the ATSC digital television standard. ATSC and 8VSB modulation is used primarily in North America; in contrast, the DVB-T standard uses COFDM. A modulation method specifies how the radio sign ...
modulation Signal modulation is the process of varying one or more properties of a periodic waveform in electronics and telecommunication for the purpose of transmitting information. The process encodes information in form of the modulation or message ...
and unvariable
guard interval In telecommunications Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication techno ...
used in ATSC standards than with the
orthogonal frequency-division multiplexing In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission used in digital modulation for encoding digital (binary) data on multiple carrier frequencies. OFDM has developed into a popular scheme for ...
(OFDM) used in the European and Australian
DVB-T DVB-T, short for Digital Video Broadcasting – Terrestrial, is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in Singapore in Fe ...
standard. A distributed transmission system would have stringent synchronization requirements, requiring each transmitter to receive its signal from a central source for broadcast at a GPS-synchronized time. A DTS does not use broadcast repeaters in the conventional sense, since they cannot receive a signal from a main terrestrial broadcast transmitter for rebroadcast; to do so would introduce a re-transmission delay destroying the required synchronization, causing interference between transmitters. The use of
virtual channel In most telecommunications organizations, a virtual channel is a method of remapping the ''program number'' as used in H.222 Program Association Tables and Program Mapping Tables to a channel number that can be entered as digits on a receiver's ...
s is another alternative, although this may cause the same channel to appear several times in a receiver – once for each relay station – and require the user to tune to the best one (which may change due to propagation issues such as weather). Although boosters or DTS cause all relay stations to appear as one signal, they require careful
engineering Engineering is the practice of using natural science, mathematics, and the engineering design process to Problem solving#Engineering, solve problems within technology, increase efficiency and productivity, and improve Systems engineering, s ...
to avoid interference.


Satellite stations

Some licensed stations
simulcast Simulcast (a portmanteau of "simultaneous broadcast") is the broadcasting of programs or events across more than one resolution, bitrate or medium, or more than one service on the same medium, at exactly the same time (that is, simultaneously) ...
another station. Relay stations in name only, they are generally licensed like any other station. Although this is unregulated in the U.S. and widely permitted in
Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...
, the U.S.
Federal Communications Commission The Federal Communications Commission (FCC) is an independent agency of the United States government that regulates communications by radio, television, wire, internet, wi-fi, satellite, and cable across the United States. The FCC maintains j ...
(FCC) regulates
radio format A radio format or programming format (not to be confused with broadcast programming) describes the overall content broadcast on a radio station. The radio format emerged mainly in the United States in the 1950s, at a time when Radio broadcasting, ...
s to ensure diversity in programming. U.S. satellite stations may request an FCC exemption from requirements for a properly staffed broadcast studio in the
city of license In U.S., Canadian, and Mexican broadcasting, a city of license or community of license is the community that a radio station or television station is officially licensed to serve by that country's broadcast regulator. In North American broadcast ...
. The stations often cover large, sparsely populated regions or operate as statewide
non-commercial educational A non-commercial educational station (NCE station) is a radio station or television station that does not accept on-air advertisements (television advertisement, TV ads or radio advertisement, radio ads), as defined in the United States by the Fed ...
radio Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3  hertz (Hz) and 300  gigahertz (GHz). They are generated by an electronic device called a transmitter connec ...
and
television Television (TV) is a telecommunication medium for transmitting moving images and sound. Additionally, the term can refer to a physical television set rather than the medium of transmission. Television is a mass medium for advertising, ...
systems.


Semi-satellites

A television re-broadcaster often sells local (or regional) advertising for broadcast only on the local transmitter, and may air a limited amount of programming distinct from its parent station. Some "semi-satellites" broadcast local news or separate news segments during part of the
newscast News broadcasting is the medium of broadcasting various news events and other information via television, radio, or the internet in the field of broadcast journalism. The content is usually either produced locally in a radio studio or tele ...
.
CHEX-TV-2 CHEX-DT-2 (channel 22) is a television station licensed to Oshawa, Ontario, Canada, serving the Regional Municipality of Durham as part of the Global Television Network. It is owned and operated by network parent Corus Entertainment, and maintai ...
in
Oshawa Oshawa is a city in Ontario, Canada, on the Lake Ontario shoreline. It lies in Southern Ontario, approximately east of downtown Toronto. It is commonly viewed as the eastern anchor of the Greater Toronto Area and of the Golden Horseshoe. It ...
,
Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...
, aired daily late-afternoon and early-evening news and community programs separate from its parent station, CHEX-TV in
Peterborough, Ontario Peterborough ( ) is a city on the Otonabee River in Ontario, Canada, about 125 kilometres (78 miles) northeast of Toronto. According to the 2021 Census, the population of the City of Peterborough was 83,651. The population of the Peterborough ...
. The FCC prohibits this on U.S. FM translator stations, only permitting it on fully licensed stations. In some cases, a semi-satellite is a formerly autonomous full-service station which is programmed remotely through
centralcasting In terrestrial radio and television broadcasting, centralcasting refers to the use of systems automation by which customised signals for broadcast by multiple individual stations may be created at one central facility. Definition Centralcasting ...
or
broadcast automation Broadcast automation incorporates the use of broadcast programming technology to automate broadcasting operations. Used either at a broadcast network, radio station or a television station, it can run a facility in the absence of a human oper ...
to avoid the cost of a local staff. CBLFT, an
owned-and-operated station In the broadcasting industry, an owned-and-operated station (frequently abbreviated as an O&O) usually refers to a television or radio station owned by the network with which it is associated. This distinguishes such a station from an network af ...
of the
French-language French ( or ) is a Romance language of the Indo-European family. Like all other Romance languages, it descended from the Vulgar Latin of the Roman Empire. French evolved from Northern Old Gallo-Romance, a descendant of the Latin spoken in ...
network
Ici Radio-Canada Télé Ici Radio-Canada Télé (stylized as ICI Radio-Canada Télé, and sometimes abbreviated as Ici Télé) is a Television in Canada, Canadian Canadian French, French-language terrestrial television, free-to-air television network owned by the Can ...
in
Toronto Toronto ( , locally pronounced or ) is the List of the largest municipalities in Canada by population, most populous city in Canada. It is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a p ...
, is a ''de facto'' semi-satellite of its stronger
Ottawa Ottawa is the capital city of Canada. It is located in the southern Ontario, southern portion of the province of Ontario, at the confluence of the Ottawa River and the Rideau River. Ottawa borders Gatineau, Gatineau, Quebec, and forms the cor ...
sibling CBOFT; its programming has long been identical or differed only in local news and advertising. A financially weak privately owned broadcaster in a small market can become a ''de facto'' semi-satellite by gradually curtailing local production and relying on a commonly owned station in a larger city for programming;
WWTI WWTI (channel 50) is a television station in Watertown, New York, United States, affiliated with American Broadcasting Company, ABC. Its second digital subchannel serves as an owned-and-operated station of The CW (via The CW Plus). Owned by Nexs ...
in
Watertown, New York Watertown is a city in and the county seat of Jefferson County, New York, United States. It is approximately south of the Thousand Islands, along the Black River, about east of where it flows into Lake Ontario. The city is bordered by the t ...
, relies on WSYR-TV in this manner. Broadcast automation allows the substitution of syndicated programming or
digital subchannel In broadcasting, digital subchannels are a method of transmitting more than one independent program stream simultaneously from the same digital radio or television station on the same radio frequency channel. This is done by using data compress ...
content which the broadcaster was unable to obtain for both cities. Some defunct full-service stations (such as CJSS-TV in
Cornwall, Ontario Cornwall is a city in Eastern Ontario, Canada, situated where the provinces of Central Canada, Ontario and Quebec and the U.S. state of New York (state), New York converge. It is Ontario's easternmost city. Although it is the seat of the United ...
, now CJOH-TV-8) have become full satellite stations and originate nothing. If programming from the parent station must be removed or substituted due to local sports blackouts, the modified signal is that of a semi-satellite station.


National networks

Most broadcasters outside North America, portions of South America, and Japan maintain a national network, and use relay transmitters to provide service to a region (or nation). Compared with other types of relays, the transmitter network is often created and maintained by an independent authority (funded with television license fees); several major broadcasters use the same transmitters. In North America, a similar pattern of regional network broadcasting is sometimes used by state- or province-wide
educational television Educational television or learning television is the use of television programs in the field of distance education. It may be in the form of individual television programs or dedicated specialty channels that are often associated with cable televi ...
networks. A state or province establishes an educational station and extends it with several full-power transmitters to cover the entire jurisdiction, with no capability for local-programming origination. In the U.S., such regional networks are member stations of the national
Public Broadcasting Service The Public Broadcasting Service (PBS) is an American public broadcaster and non-commercial, free-to-air television network based in Arlington, Virginia Arlington County, or simply Arlington, is a County (United States), county in the ...
.


By country


Canada

In Canada, "re-broadcaster" or "re-broadcasting transmitter" are the terms most commonly used by the
Canadian Radio-television and Telecommunications Commission The Canadian Radio-television and Telecommunications Commission (CRTC; ) is a public organization in Canada tasked with the mandate as a regulatory agency tribunal for various electronic communications, covering broadcasting and telecommunic ...
(CRTC).


Television

A television re-broadcaster may sell local or regional advertising for broadcast only on the local transmitter. Rarely, they may air limited programming distinct from their parent station. Some "semi-satellites" broadcast local newscasts or separate news segments in part of a newscast. There is no strict rule for the
call sign In broadcasting and radio communications, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a unique identifier for a transmitter station. A call sign can be formally as ...
of a television re-broadcaster. Some transmitters have call signs different from the parent station ( CFGC in Sudbury is a re-broadcaster of CIII), and others use the call sign of the originating station followed by a number (such as the former CBLFT-17 in
Sarnia Sarnia is a city in Lambton County, Ontario, Canada. It had a Canada 2021 Census, 2021 population of 72,047, and is the largest city on Lake Huron. Sarnia is located on the eastern bank of the junction between the Upper and Lower Great Lakes, ...
, Ontario). The latter type officially includes the television station's -TV suffix between the call sign and the number, although it is often omitted from media directories. The numbers are usually applied sequentially, beginning with "1", and denote the chronological order in which the station's rebroadcast transmitters began operation. Some broadcasters may use a system in which the number is the transmitter's broadcast channel, such as CJOH-TV-47 in
Pembroke, Ontario Pembroke ( ) is a city in the Canadian province of Ontario at the confluence of the Muskrat River (Ontario), Muskrat River and the Ottawa River in the Ottawa Valley, northwest of Ottawa. Though containing the administrative headquarters of Renfre ...
. A broadcaster cannot mix the numbering systems under a single call sign; the transmitters are numbered sequentially or by their analogue channel. If sequential numbering reaches 99 (such as
TVOntario TVO (stylized in all lowercase as tvo), formerly known as TVOntario, is a Canadian Public broadcasting, publicly funded English-language educational television network and media organization serving the Canadian province of Ontario. It operates ...
's former broadcast transmitters), the next transmitter is assigned a new call sign and numbered "1". Translators which share a frequency (such as CBLT's former repeaters CBLET, CBLHT, CBLAT-2 and CH4113 on channel 12) are given distinct call signs. Digital re-broadcasters may be numbered by the TV channel number of the analogue signal they replaced. TVOntario's CICO-DT-53 (digital UHF 26, Belleville) is an example; the station was converted in 2011 to vacate an out-of-core analogue channel (UHF 53), and retains CICO-TV-53's former analogue UHF television call-sign numbering as a surviving TVO repeater. Low-power re-broadcasters may have a call sign consisting of the letters CH followed by four numbers; for example, CH2649 in Valemount,
British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...
, is a re-broadcaster of
Vancouver Vancouver is a major city in Western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the cit ...
's CHAN. Re-broadcasters of this type are numbered sequentially in the order they were licensed by the CRTC, and their call signs are unrelated to the parent station or other re-broadcasters. Although the next number in the sequence (CH2650 in Anzac, Alberta) is a re-broadcaster of CHAN, this is because CH2649 and CH2650 were licensed simultaneously; the following number, CH2651, is a re-broadcaster (also in Anzac) of
Edmonton Edmonton is the capital city of the Provinces and territories of Canada, Canadian province of Alberta. It is situated on the North Saskatchewan River and is the centre of the Edmonton Metropolitan Region, which is surrounded by Central Alberta ...
's
CITV CITV is a British children's morning programming block on ITV2 and formerly a free-to-air channel owned by ITV plc. CITV, then Children's ITV, launched on 3 January 1983 as a late afternoon programming block on the ITV network for children aged ...
. A station's re-broadcasters are not necessarily named in the same manner; CBLT had re-transmitters with their own call signs (some used CBLT followed by a number, and some used CH numbers). CBC and Radio-Canada owned-and-operated re-transmitters were shut down on August 1, 2012, along with most TVOntario transmitters (which often were located at Radio-Canada sites) and some
Aboriginal Peoples Television Network Aboriginal Peoples Television Network (APTN) is a group of Television in Canada, Canadian Specialty channel, specialty television channels based in Winnipeg, Manitoba. The channels broadcast programming produced by or highlighting Indigenous p ...
(APTN) transmitters in the far north. Private commercial broadcasters operate full-power re-broadcasters to obtain "must carry" status on
cable television Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with bro ...
systems. Transmitters in small markets with one (or no) originating stations were, in most cases, not required to convert to digital even if operating at full power. Transmitters broadcasting on UHF channels 52–69 were required to vacate the channels by August 31, 2011; some (such as a
CKWS-TV CKWS-DT (channel 11) is a television station in Kingston, Ontario, Canada, part of the Global Television Network. Owned and operated by network parent Corus Entertainment, the station maintains studios on Queen Street in downtown Kingston, and i ...
re-transmitter in
Brighton, Ontario Brighton is a town in Northumberland County, Ontario, Northumberland County, Ontario, Canada, approximately east of Toronto and west of Kingston, Ontario, Kingston. It is traversed by both Ontario Highway 401, Highway 401 and the former Ontario ...
, and three TVOntario sites) went digital as part of a move to a lower frequency but do not provide
high-definition television High-definition television (HDTV) describes a television or video system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since at least 1933; in more recent times, it ref ...
,
digital subchannel In broadcasting, digital subchannels are a method of transmitting more than one independent program stream simultaneously from the same digital radio or television station on the same radio frequency channel. This is done by using data compress ...
s or any functions beyond that of the original analogue site.


Radio

Like a TV station, a radio re-broadcaster may have a distinct call sign or use the call sign of the originating station followed by a numeric suffix. The numeric suffix is always sequential. For a re-broadcaster of an FM station, the numeric suffix is appended to the FM suffix; re-broadcasters of CJBC-FM in Toronto are numbered CJBC-FM-1, CJBC-FM-2, etc. If an AM station has a re-broadcaster on the FM band, the numeric suffix falls between the four-letter call sign and the FM suffix; CKSB-1-FM is an FM re-broadcaster of the AM station CKSB, and CKSB-FM-1 would be a re-broadcaster of CKSB-FM. A broadcaster is limited to two stations on one band in a market, but a possible means to obtain a third FM signal in-market is to use a re-broadcaster of the AM station to move the signal to low-power FM. In Sarnia,
Blackburn Radio Blackburn Radio, Inc. is a Canadian radio broadcasting group, which owns several radio stations in Southwestern Ontario. Headquartered in London, Ontario, the company is owned by 2061302 Ontario Limited, which is majority owned by Cogent Investmen ...
owns
CFGX-FM CFGX-FM is a Canadian radio station, which broadcasts at 99.9 FM broadcasting, FM in Sarnia, Ontario. The station broadcasts an adult top 40 format with the brand name ''The Fox'' and slogan ''Today's Best Music''. CFGX-FM can be heard in the ea ...
(99.9) and
CHKS-FM CHKS-FM is a Canadian radio station, which broadcasts at 106.3 FM broadcasting, FM in Sarnia, Ontario. The station broadcasts a classic hits format with the brand name ''Cool 106.3''. In addition to Sarnia, it also serves Port Huron, Michigan. C ...
(106.3); its third Sarnia station,
CHOK CHOK (1070  kHz, "CHOK 103.9 FM & 1070 AM") is a Canadian commercial radio station, licensed to Sarnia, Ontario, Canada, and owned by Blackburn Radio. The station broadcasts a country music format with local all-news radio, talk radio and s ...
(1070 kHz), uses an FM repeater for city coverage as Country 103.9 FM (although the AM signal remains the station's official primary transmitter). Low-power radio re-broadcasters may have a call sign consisting of VF followed by four numbers; a call sign of this type may also denote a low-power station which originates its own programming. Some stations licensed under the CRTC's experimental-broadcasting guidelines, a special class of short-term license (similar to
special temporary authority Special Temporary Authority (STA) in U.S. broadcast law is a type of broadcast license which temporarily allows a broadcast station to operate outside of its normal technical or legal parameters. In the Federal Communications Commission (FCC) st ...
) sometimes granted to newer
campus A campus traditionally refers to the land and buildings of a college or university. This will often include libraries, lecture halls, student centers and, for residential universities, residence halls and dining halls. By extension, a corp ...
and
community radio Community radio is a radio service offering a third model of radio broadcasting in addition to commercial broadcasting, commercial and public broadcasting. Community broadcasting, Community stations serve geographic communities and communities o ...
operations, may have a call sign consisting of three letters from anywhere in Canada's ITU-prefix range followed by three digits (such as CFU758 or VEK565). Other stations in this license class have been assigned conventional Cxxx call signs. Former re-broadcasters have occasionally been converted to originating stations, retaining their former call sign; examples include CITE-FM-1 in
Sherbrooke Sherbrooke ( , ) is a city in southern Quebec, Canada. It is at the confluence of the Saint-François River, Saint-François and Magog River, Magog rivers in the heart of the Estrie administrative region. Sherbrooke is also the name of a territ ...
, CBF-FM-8 in
Trois-Rivières Trois-Rivières (, ; ) is a city in the Mauricie administrative region of Quebec, Canada. It is located at the confluence of the Saint-Maurice River, Saint-Maurice and Saint Lawrence River, Saint Lawrence rivers, on the north shore of the Sain ...
and CBAF-FM-15 in
Charlottetown Charlottetown is the capital and largest city of the Provinces and territories of Canada, Canadian province of Prince Edward Island, and the county seat of Queens County, Prince Edward Island, Queens County. Named after Queen Charlotte, Charlott ...
.


Mexico

In
Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
, translator and booster stations are given the call sign of the parent station.


Television

Most television stations in Mexico are operated as repeaters of the networks they broadcast. Translator stations in Mexico are given call signs beginning with XE and XH.
Televisa Grupo Televisa, S.A.B., simply known as Televisa, is a Mexican telecommunications and broadcasting company. A major Latin American mass media corporation, it often presents itself as the largest producer of Spanish-language content. In April ...
and Azteca maintain two national networks apiece. Televisa's
Las Estrellas Las Estrellas () is a Mexican television network owned by TelevisaUnivision. Its first official broadcast took place on 21 March 1951. It airs free-to-air through affiliate stations throughout Mexico, based on XEW-TDT in Mexico City. It is con ...
network includes 128 stations (the most in Mexico), and Azteca's networks have 88 and 91 stations. The stations may insert local advertising. Azteca's stations in larger cities may include local news and a limited amount of regional content;
Televisa Grupo Televisa, S.A.B., simply known as Televisa, is a Mexican telecommunications and broadcasting company. A major Latin American mass media corporation, it often presents itself as the largest producer of Spanish-language content. In April ...
prefers to use its non-national Gala TV network and Televisa Regional stations as outlets for local production. A number of translators also serve areas with little or no signal in their defined coverage area, known as ('shadow channels'). Most shadow channels air the same programming as their parent station. The northern and central regional network Multimedios Televisión in
Monterrey Monterrey (, , abbreviated as MtY) is the capital and largest city of the northeastern Mexican state of Nuevo León. It is the ninth-largest city and the second largest metropolitan area, after Greater Mexico City. Located at the foothills of th ...
uses the same system to a smaller extent (its XHSAW-TDT is the shadow channel of main station XHAW-TDT in Monterrey), with regional output for local newscasts and advertising on a master schedule. There are two main national networks of non-commercial TV stations in Mexico. One is the Canal Once (or XEIPN-TDT) network, operated by the
Instituto Politécnico Nacional The National Polytechnic Institute (), abbreviated IPN, is one of the largest public universities in Mexico with 171,581 students at the high school, undergraduate and postgraduate levels. It is the second-best university in Mexico in the techni ...
(IPN). Operating 13 transmitters, it airs its programs under a contract with the Quintana Roo state network. The other network, operated by the
Sistema Público de Radiodifusión del Estado Mexicano AFK Sistema PAO is a large Russian conglomerate company, founded by Vladimir Yevtushenkov, who was chairman of the corporation's board of directors until 2022. In April, Yevtushenkov's shareholding in Sistema has decreased to 49.2%, and he also ...
(SPR), has 26 stations (16 operational); most are digital. The SPR transmitters are almost exclusively in cities where the IPN never built stations, and carry Canal Once as one of the five educational networks in the
multiplex Multiplex may refer to: Science and technology * Multiplex communication, combining many signals into one transmission circuit or channel ** Multiplex (television), a group of digital television or radio channels that are combined for broadcast * ...
of the digital station. Twenty-six of Mexico's 32 states also own and operate television services, and 16 use more than one transmitter. The largest (by number of stations) is Telemax,
Sonora Sonora (), officially Estado Libre y Soberano de Sonora (), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is divided into Municipalities of Sonora, 72 ...
's state network, with 59 transmitters. Many state-network transmitters broadcast at a low
effective radiated power Effective radiated power (ERP), synonymous with equivalent radiated power, is an IEEE standardized definition of directional radio frequency (RF) power, such as that emitted by a radio transmitter. It is the total power in watts that would ha ...
(ERP). A few stations are owned by municipalities or translator associations. Like state networks, they transmit at very low power. Transmitters re-broadcasting Mexico City stations to
Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...
and other communities along the Pacific coast normally operate on a two-hour delay behind the originating station; there is a one-hour delay in
Sonora Sonora (), officially Estado Libre y Soberano de Sonora (), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is divided into Municipalities of Sonora, 72 ...
, and
Quintana Roo Quintana Roo, officially the Free and Sovereign State of Quintana Roo, is one of the 31 states which, along with Mexico City, constitute the 32 administrative divisions of Mexico, federal entities of Mexico. It is divided into municipalities of ...
(one hour ahead of central Mexico in 2015) receives programs one hour later than they are broadcast to most of the rest of Mexico.


Radio

Ten to 15 FM shadow channels exist, and they are required to be co-channel with the stations they re-transmit. Quintana Roo has the most FM shadow channels (seven), about half the national total. Three more FM shadows are authorized: XETIA-FM/ XEAD-FM ( Ajijic,
Jalisco Jalisco, officially the Free and Sovereign State of Jalisco, is one of the 31 states which, along with Mexico City, comprise the 32 Political divisions of Mexico, Federal Entities of Mexico. It is located in western Mexico and is bordered by s ...
) and XHRRR-FM (Tecolula,
Veracruz Veracruz, formally Veracruz de Ignacio de la Llave, officially the Free and Sovereign State of Veracruz de Ignacio de la Llave, is one of the 31 states which, along with Mexico City, comprise the 32 Political divisions of Mexico, Federal Entit ...
).


United States


Radio

In July 2009, the basic FCC regulations concerning translators were: * FM translators may be used for cross-band translation; this removed the restriction preventing FM translators from re-transmitting AM signals. * No translator (or booster) may transmit anything other than the
simulcast Simulcast (a portmanteau of "simultaneous broadcast") is the broadcasting of programs or events across more than one resolution, bitrate or medium, or more than one service on the same medium, at exactly the same time (that is, simultaneously) ...
of its licensed parent station, except for emergency warnings (such as EAS) and 30 seconds per hour of fundraising. * The parent station must identify all its translators and boosters between 7 and 9a.m., 12:55 and 1:05 p.m., and 4 and 6p.m. each broadcast day, or each must be equipped with an automated device (audio or FSK) for hourly identification. * Maximum power is 250 watts ERP for a translator, and 20 percent of the maximum allowable ERP for the primary station's class for a booster. There is no limit on
height Height is measure of vertical distance, either vertical extent (how "tall" something or someone is) or vertical position (how "high" a point is). For an example of vertical extent, "This basketball player is 7 foot 1 inches in height." For an e ...
for fill-in translators within the
service contour In US broadcasting, service contour (or protected contour) refers to the area in which the Federal Communications Commission (FCC) predicts coverage. The FCC calculates FM and TV contours based on effective radiated power (ERP) in a given direct ...
of the primary station. * A translator (or booster) must stop transmitting if the parent station's signal is lost; this helps prevent unauthorized re-transmission of other stations. There is one way programming may differ between a main station and an FM translator: an
HD Radio HD Radio (HDR) is a trademark for in-band on-channel (IBOC) digital radio broadcast technology. HD radio generally simulcast, simulcasts an existing analog radio station in digital format with less noise and with additional text information. HD R ...
signal may contain
digital subchannel In broadcasting, digital subchannels are a method of transmitting more than one independent program stream simultaneously from the same digital radio or television station on the same radio frequency channel. This is done by using data compress ...
s with different programming from the main analogue channel, and a translator may broadcast programming from the originating station's HD2 subchannel as the translator's main analogue signal. W237DE (95.3 MHz in
Harrisburg, Pennsylvania Harrisburg ( ; ) is the capital city of the U.S. commonwealth of Pennsylvania and the seat of Dauphin County. With a population of 50,099 as of 2020, Harrisburg is the ninth-most populous city in Pennsylvania. It is the larger of the two pr ...
) broadcasts the format formerly carried by WTCY (1400 AM, now WHGB), receiving the signal from a WNNK (104.1 FM) HD2 digital subchannel for analogue rebroadcast from the WNNK tower site on 95.3. It is legally an FM repeater of an FM station, although each signal would be heard with unique content by users with analogue
FM radio FM broadcasting is a method of radio broadcasting that uses frequency modulation (FM) of the radio broadcast carrier wave. Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to transmit high fidelity, high-f ...
receivers. Commercial stations may own their translators (or boosters) when the translator (or booster) is in the parent station's primary service contour; they can only fill in where
terrain Terrain (), alternatively relief or topographical relief, is the dimension and shape of a given surface of land. In physical geography, terrain is the lay of the land. This is usually expressed in terms of the elevation, slope, and orientati ...
blocks the signal. Boosters may only be owned by the primary station; translators outside a primary station's service contour cannot be owned by (or receive financial support from) the primary station. Most translators operate by receiving the main station's on-air signal with a directional antenna and sensitive receiver and re-transmitting the signal. They may not transmit in the FM reserved band from 88 to 92
MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base u ...
, where only
non-commercial A non-commercial (also spelled noncommercial) activity is an activity that is not carried out in the interest of Profit (economics), profit. The opposite is Commerce, commercial, something that primarily serves profit interests and is focused on bu ...
stations are allowed. Non-commercial stations may broadcast in the commercial portion of the band. Unlike commercial stations, they can relay programming to translators via
satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...
if the translators are in the reserved band. Translators in the commercial band may only be fed by a direct on-air signal from another FM station (or translator). Non-fill-in commercial-band translators may not be fed by satellite, according to FCC rule 74.1231(b). All stations may use any means to feed a booster. All U.S. translator and booster stations are low-power and have a class D license, making them secondary to other stations (including the parent); they must accept
interference Interference is the act of interfering, invading, or poaching. Interference may also refer to: Communications * Interference (communication), anything which alters, modifies, or disrupts a message * Adjacent-channel interference, caused by extra ...
from full-power (100 watts or more on FM) stations, while not causing any of their own. Boosters must not interfere with the parent station in the
community of license In U.S., Canadian, and Mexican broadcasting, a city of license or community of license is the community that a radio station or television station is officially licensed to serve by that country's broadcast regulator. In North American broadcast ...
. Licenses are automatically renewed with that of the parent station and do not require separate applications, although the renewal may be challenged with a petition to deny. FM booster stations are given the full call sign (including an -FM
suffix In linguistics, a suffix is an affix which is placed after the stem of a word. Common examples are case endings, which indicate the grammatical case of nouns and adjectives, and verb endings, which form the conjugation of verbs. Suffixes can ca ...
, even if there is none assigned) of the parent station plus a
serial number A serial number (SN) is a unique identifier used to ''uniquely'' identify an item, and is usually assigned incrementally or sequentially. Despite being called serial "numbers", they do not need to be strictly numerical and may contain letters ...
such as WXYZ-FM1, WXYZ-FM2, etc. FM translator stations may use sequential numbered call signs consisting of K or W followed by a three-digit number (201 through 300, corresponding to 88.1 to 107.9 MHz), followed by a pair of sequentially assigned letters. The format is similar to that used by numbered television translators, where the number refers to the permanent channel assignment. The largest terrestrial radio-translator system in the U.S. in October 2008 belonged to KUER-FM, the non-commercial radio outlet of the
University of Utah The University of Utah (the U, U of U, or simply Utah) is a public university, public research university in Salt Lake City, Utah, United States. It was established in 1850 as the University of Deseret (Book of Mormon), Deseret by the General A ...
, with 33 translator stations ranging from
Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...
to
New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...
and
Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...
.


Television

Unlike FM radio, low-power television stations may operate as translators or originate their own programming. Translator stations are given call signs which begin with W (east of the
Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...
) or K (west of the Mississippi, like regular stations) followed by a channel number and two serial letters for each channel; the first stations on a channel are AA, AB, AC and so on. Television channels have two digits, from 02 to 36 (formerly 02 to 83; 02 to 69 and 02 to 51); FM radio channels are numbered from 200 (87.9 MHz) to 300 (107.9 MHz), one every 0.2 MHz (for example, W42BD or K263AF). An X after the number in these call signs does not indicate an experimental broadcasting license (as it may in other services), since all 26 letters are used in the sequence. When the sequence is exhausted, another letter is added. This has already happened for translator on channels 7 and 13 in K territory; what is now KMNF-LD was assigned callsign K13AAR-D in September 2018 and K07AAH-D in May 2019. Numbered translator stations (a format such as W70ZZ) are typically low-power repeaters – often 100 watts (or less) on FM and 1,000 watts (or less) on television. The former translator band,
UHF Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter ...
television channels 70 through 83, was originally occupied primarily by low-powered translators. The combination of low power and high frequency limited broadcast range. The band was reallocated to
cellular telephone A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This radio ...
services during the 1980s, with the handful of remaining transmitters moved to lower frequencies. Full-power repeaters such as WPBS-TV's identical-twin transmitter, WNPI-TV, are normally assigned TV call signs like other full-power stations. These "satellite stations" do not have numbered call signs, and must operate in the same manner as other full-power broadcasters. This simulcasting is generally not regulated by the FCC, except when a station owner seeks an exemption from requirements such as restrictions on owning several full-service stations in the same market, limits on overlap in coverage area between commonly owned stations, or requirements that each full-service station have a local studio and a skeleton staff capable of originating programming locally. These exemptions are normally justified on the basis of economic hardship, where a rural location unable to support a full-service originating station may be able to sustain a full-power re-broadcaster. Some stations (such as
KVRR KVRR (channel 15) is a television station in Fargo, North Dakota, United States, affiliated with the Fox Broadcasting Company, Fox network. Owned by Coastal Television Broadcasting Company, the station maintains studios on South 40th Street an ...
in
Fargo, North Dakota Fargo is the List of cities in North Dakota, most populous city in the U.S. state of North Dakota and the county seat of Cass County, North Dakota, Cass County. The population was 125,990 at the 2020 United States census, 2020 census, which was e ...
) are chains of as many as four full-power transmitters, each with its own call sign and license, covering a large, sparsely populated region. LPTV stations may also choose a four-letter call sign with an -LP suffix (shared with low-power FM) for analog or -LD for digital; this is generally done only if the station originates programming.
Class A television The class A television service is a system for regulating some low-power television (LPTV) stations in the United States. Class A stations are denoted by the broadcast callsign suffix "-CA" (analog) or "-CD" (digital), although very many analog ...
stations are assigned calls with -CA and -CD suffixes. Digital stations which use numbers receive a -D suffix, such as W42BD-D. All are despite the fact that most of the full-power digital television stations had their -DT (originally -HD) suffixes dropped by the FCC before -D and -LD were implemented. Digital LPTV stations have their digital RF channel numbers as part of their digital call sign, which may differ from the
virtual channel In most telecommunications organizations, a virtual channel is a method of remapping the ''program number'' as used in H.222 Program Association Tables and Program Mapping Tables to a channel number that can be entered as digits on a receiver's ...
(the analog number). Numbered broadcast translators which are moved to another frequency are normally issued new call signs to reflect the updated channel assignment. This is not true of displaced translators using another frequency temporarily under a special technical authority. Although K55KD could retain its call sign while it was displaced temporarily to channel 57 to resolve interference to
MediaFLO MediaFLO was a technology developed by Qualcomm for transmitting audio, video and data to portable devices such as mobile phones and personal televisions, used for mobile television. Qualcomm operated a mobile pay television service, FLO TV, from ...
users, W81AA received the new call sign W65AM when channel 81 was deleted from the bandplan and the translator was moved to channel 65. On the rare occasion that a station moves back to its original channel, it receives its old call sign (which is not reused by another station).


=Digital transition

= Low-power television stations are not required to simulcast a digital signal, nor were they required to cease analog operation in June 2009 like full-power stations. Full-power stations used for simulcasting another station were (like other full-service TV broadcasters) required to convert to digital in June 2009. The FCC defines "TV satellite stations" as "full-power broadcast stations authorized under Part 73 of the Commission's rules to re-transmit all or part of the programming of a parent station that is typically commonly owned". Since most satellite stations operate in small or sparsely populated areas with an insufficient economic base to support full-service operations, many received FCC authorization on a case-by-case basis to flash cut from analog to digital on the same channel instead of simulcasting in both formats during the digital transition. Although no digital television mandates were forced on existing low-power television stations, Congress passed legislation in 2008 funding low-power stations which went digital by the conversion date or shortly thereafter. Some low-power stations were forced to change frequency to accommodate full-power stations which moved to UHF or operated digital companion channels on UHF during the transition period. By 2008, low- and full-power channel 55 licensees were encouraged to relocate early to free spectrum for
Qualcomm Qualcomm Incorporated () is an American multinational corporation headquartered in San Diego, California, and Delaware General Corporation Law, incorporated in Delaware. It creates semiconductors, software and services related to wireless techn ...
's MediaFLO transmitters. By 2011, remaining LPTV broadcasters on UHF channels 52 through 69 were forced onto lower channels. Many transmitters on the original UHF 70–83 translator band had to move twice; channels 70–83 were lost to mobile phones in 1983, followed by channels 52–69 between 2009 and 2011. Many low-power translators were also directly affected by a parent station's conversion to digital television. Translators which received an analog over-the-air signal from a full-service television station for rebroadcast needed to convert their receiving equipment, like individual viewers used digital converter boxes. Although the signal transmitted by the repeater may have remained analog, the
uplink In a telecommunications network, a link is a communication channel that connects two or more devices for the purpose of data transmission. The link may be a dedicated physical link or a virtual circuit that uses one or more physical links or shar ...
had to be changed. Twenty-three percent of the 4,000 licensed translators received a $1,000 federal-government subsidy for a portion of the additional equipment. Many other translators went
dark Darkness is the condition resulting from a lack of illumination, or an absence of visible light. Human vision is unable to distinguish colors in conditions of very low luminance because the hue-sensitive photoreceptor cells on the retina are ...
after the digital-transition deadline, or did not apply for new channels after UHF channels 52–69 were removed from the bandplan. Some small translators operated by directly converting a parent station's signal to another frequency for rebroadcast, without any other local signal processing or demodulation. W07BA (a 16-watt repeater for WSYR-TV in
Syracuse, New York Syracuse ( ) is a City (New York), city in and the county seat of Onondaga County, New York, United States. With a population of 148,620 and a Syracuse metropolitan area, metropolitan area of 662,057, it is the fifth-most populated city and 13 ...
) was a simple piece of broadcast apparatus, shifting the main station's signal from channel nine to channel seven to cover a small valley in DeWitt. Syracuse became a UHF island, WSYR-TV's main ABC signal became a 100 kW digital broadcast on channel 17, and there is no longer a channel 9 signal to feed the repeater. Translators in remote locations with no
commercial power Economic power refers to the ability of countries, businesses or individuals to make decisions on their own that benefit them. Scholars of international relations also refer to the economic power of a country as a factor influencing its power in ...
were expected to have problems deploying equipment for a digital uplink. Although many translators continued analog broadcasts and a minority transitioned to digital, some rural communities expected to find all local translator signals gone as a result of the originating stations' transition.


Controversy

By law, full-service local broadcasters are the primary occupants of the FM broadcast band; LPFM and translators are secondary occupants, with theoretically-equal status. In practice, frequencies assigned to translators become unavailable to new LPFM stations or existing stations wishing to upgrade. Some distinctions place small, local LPFM operators at a disadvantage: * The maximum power for an LPFM station (10 or 100 watts, depending on station class) is less than that of the largest FM broadcast translators (250 watts), limiting the reach of the LPFM signal. * Minimum spacing (in distance and frequency) between stations is less strict for translators than for LPFM applicants. Although translator spacing is based on signal contour levels (accounting for terrain and obstacles), LPFM stations have a more restrictive minimum-distance requirement. * An LPFM broadcaster is required to generate local content; if there are several applicants for a frequency, those who agree to originate eight (or more) hours a day of local programming are favored. Translators are not required to originate anything locally. * LPFM licenses are normally issued to non-commercial educational entities (such as schools or municipalities), and are subject to requirements precluding several commonly owned stations; this is not true of translators. A non-commercial translator with no local or educational content can occupy space in the non-commercial segment (below 92 MHz) of the FM broadcast band. During the narrow FCC filing windows for new applicants, applications for broadcast translators from the same (or related) entities can request every locally-available frequency in several communities. Broadcast translators for commercial stations are normally required to receive a signal from their parent full-service FM station
over the air Over the Air was an annual mobile technology-focused overnight Hackathon, hack day event held in London from 2008 to 2016. The two-day event would include practical and educational talks and a hacking competition. Sponsors of the event have inc ...
and re-transmit in the region covered by the main station, eliminating the need for a translator except where
terrain shielding Terrain (), alternatively relief or topographical relief, is the dimension and shape of a given surface of land. In physical geography, terrain is the lay of the land. This is usually expressed in terms of the elevation, slope, and orientati ...
is a problem). This restriction does not apply to
non-commercial educational A non-commercial educational station (NCE station) is a radio station or television station that does not accept on-air advertisements (television advertisement, TV ads or radio advertisement, radio ads), as defined in the United States by the Fed ...
stations. Any non-commercial station, even one with no local or educational content, can apply for an unlimited number of translators to be fed by any means (including satellite). All take spectrum from local LPFM stations or rebroadcasters of local full-service stations.


=2003 translator boom

= A 2003 FCC licensing window for new translator applications resulted in over 13,000 applications. Due to the number of license applications, LPFM advocates called it the Great Translator Invasion. Some broadcasters have taken advantage of FM translator regulations allowing non-commercial stations to feed distant translators with
satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...
-delivered programming hundreds (or thousands) of miles from the parent station's coverage area. The largest satellite-fed translator network was
CSN International CSN Radio is a Christian radio network based in Twin Falls, Idaho. KAWZ, 89.9 MHz, in Twin Falls is the uplink station, feeding over 348 broadcast translators and 59 full-power radio stations across the United States, including Alaska and the ...
. Other networks and individual churches affiliated with Calvary Chapel have also submitted multiple applications for translators. Not all translators can be fed by satellites; only those in the non-commercial portion of the FM band (88.1 to 91.9 MHz) can be "satellators". All other translators must be directly fed off the air, except for "fill-in" facilities in a primary station's service contour. Translators may feed other translators, so it is possible to create small chains of translators fed from one distant station; if one translator failed, the network beyond the failed translator would go dark. The number of 2003 applications overwhelmed the FCC, which issued an emergency hold order on new translator applications until those already received were processed. The rules change sparked a series of lawsuits known as '' Prometheus Radio Project v. FCC''. LPFM advocates allege that the proliferation of translators poses difficulties for non-translator station operators (particularly LPFM license applicants), who say that they cannot get stations on the air because translators occupy available channels in an area. Since "satcasting" translators are only permitted on the non-commercial part of the spectrum (where LPFM stations do not exist), they do not threaten the ability of LPFM licensees to expand their facilities. Non-satcasting translators may be a problem for LPFM stations; if an LPFM station is "bumped" from its channel by a new full-power station, there may be no available frequency to which to move. Proposed rules would revise the procedures by which nonprofit groups may apply for translators (prohibiting more than a certain number of translator applications to be owned by any one entity), and the FCC modified its channel requirements for LPFM broadcasters to free channel space. REC Networks petitioned the FCC to prioritize LPFM stations.


Australia


Radio

Australia's national radio networks (
Radio National ABC Radio National, more commonly known as Radio National or simply RN, is an Australian nationwide public service radio network run by the Australian Broadcasting Corporation (ABC). From 1947 until 1985, the network was known as ABC Radio 2. ...
,
ABC NewsRadio ABC NewsRadio, since 2017 broadcast under the ABC News brand and for a short time known as ABC News on Radio, is a 24-hour news radio service broadcast by the Australian public broadcaster, the Australian Broadcasting Corporation (ABC). ABC ...
,
Triple J Triple J is an Australian government-funded national radio station founded in 1975 as a division of the Australian Broadcasting Corporation (ABC). It aims to appeal to young listeners of alternative music, and plays far more Australian conten ...
,
ABC Classic FM ABC Classic, formerly ABC-FM (also ABC Fine Music), and then ABC Classic FM, is an Australian classical music radio station available in Australia and internationally. Its website features classical music news, features and listening guides. I ...
and
SBS Radio SBS Radio is an Australian radio network owned by the Special Broadcasting Service directed towards newly arrived immigrants in Australia. It originally began as two stations based in Melbourne and Sydney, set up to provide pre-recorded informa ...
) have relay transmitters which allow each service to be broadcast as widely as possible. The ABC and SBS allow community-based relay transmitters to rebroadcast radio or television in areas which would otherwise have no service. Commercial radio broadcasters normally have relay transmitters only if local geography (such as mountains) prevents them from broadcasting to their entire market.


Television

Since the early-1990s market aggregation, each television broadcaster uses multiple relays to provide consistent service throughout Australia's large markets. Although each market is subdivided due to the legacy of previous commercial broadcasters ( Southern Cross 10 (formerly
Southern Cross Nine 10 was an Australian television network distributed by Southern Cross Austereo (SCA) in regional Queensland, southern New South Wales, the Australian Capital Territory, regional Victoria, the Spencer Gulf and Broken Hill. SCA's network was ...
) maintains two stations in the Victoria market: GLV and BCV), the only difference between these sub-markets in practice is news service and local advertising. Except in major cities, all major television broadcasters use the same network of transmitters (which may have dozens of relay stations in each market). As a result, some areas have had trouble beginning
digital Digital usually refers to something using discrete digits, often binary digits. Businesses *Digital bank, a form of financial institution *Digital Equipment Corporation (DEC) or Digital, a computer company *Digital Research (DR or DRI), a software ...
or HD service due to problems with regional transmitters.


Europe

Because most radio and television systems in Europe are national networks, the radio or television system in some countries can be considered a collection of relay stations in which each broadcaster uses a transmitter network (developed by the public broadcaster or maintained through a government-funded authority) to provide broadcast service to the entire nation.


Asia

In most parts of Asia, satellite is the preferred method of national signal coverage. Exceptions include Singapore (which bans civilian ownership of satellite receivers) and Malaysia, which only allows civilian ownership of receivers provided by Astro. Terrestrially, the scenario is similar to Europe's; the systems are considered national networks, and are a collection of relay stations maintained by a government-funded authority. In Japan and the Philippines, television stations are owned and operated by networks or are affiliates owned by other media companies.


See also

*
Airborne radio relay Airborne radio relay is a technique employing aircraft fitted with radio relay stations for the purpose of increasing the range, flexibility, or physical security of communications systems. The aircraft may be manned or unmanned aerial vehicles. U ...
*
Amateur radio repeater An amateur radio repeater is an electronic device that receives a weak or low-level amateur radio signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. Many repeaters a ...
*
Call signs in North America Call signs are frequently still used by North American broadcast stations, in addition to amateur radio and other international radio stations that continue to identify by call signs worldwide. Each country has a different set of patterns for its ...
*
Communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a Transponder (satellite communications), transponder; it creates a communication channel between a source transmitter and a Rad ...
*
Cellular repeater A cellular repeater (also known as cell phone signal booster or cell phone signal amplifier) is a type of bi-directional amplifier used to improve cell phone reception. A cellular repeater system commonly consists of a donor Antenna (radio), anten ...
*
Microwave radio relay Microwave transmission is the Data transmission, transmission of information by electromagnetic waves with wavelengths in the microwave frequency range of 300 MHz to 300 GHz (1 m - 1 mm wavelength) of the electromagnetic spectrum ...
*
Repeater In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some ...
*
Radio repeater A radio repeater is a combination of a radio receiver and a radio transmitter that receives a signal and retransmits it, so that two-way radio signals can cover longer distances. A repeater sited at a high elevation can allow two mobile stations ...
*
Relay (disambiguation) A relay is an electric switch operated by a signal in one circuit to control another circuit. Relay may also refer to: Electrical engineering * Protective relay, a device designed to trip a circuit breaker when a fault is detected. Historical * ...
* Shortwave relay station *
Transmitter station A transmitter station or transmission facility is an installation used for transmitting radio frequency signals for wireless communication, broadcasting, microwave link, mobile telephone or other purposes. Choice of location The location may ...
*
Television transmitter A television transmitter is a transmitter that is used for terrestrial television, terrestrial (over-the-air) television broadcasting. It is an electronic device that radiates radio waves that carry a video signal representing moving images, alon ...


References


External links


FCC "FM Translators and Boosters" webpage
{{DEFAULTSORT:Broadcast Relay Station Broadcast engineering Broadcast transmitters Broadcasting Television technology Television terminology