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Broadcast relay station

Broadcast relay station

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A broadcast relay station, relay transmitter, broadcast translator (U.S.), rebroadcaster (Canada), or repeater (two-way radio
Two-way radio
A two-way radio is a radio that can both transmit and receive , unlike a broadcast receiver which only receives content. The term refers to a personal radio transceiver that allows the operator to have a two-way conversation with other similar radios operating on the same radio frequency...

) is a broadcast transmitter which relay
Relay
A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. Relays are used where it is necessary to control a circuit by a low-power signal , or where several circuits must be controlled...

s, repeat
Repeater
A repeater is an electronic device that receives asignal and retransmits it at a higher level and/or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances.-Description:...

s, or reflects the signal of another radio station
Radio station
Radio broadcasting is a one-way wireless transmission over radio waves intended to reach a wide audience. Stations can be linked in radio networks to broadcast a common radio format, either in broadcast syndication or simulcast or both...

 or television station
Television station
A television station is a business, organisation or other such as an amateur television operator that transmits content over terrestrial television. A television transmission can be by analog television signals or, more recently, by digital television. Broadcast television systems standards are...

, usually to an area not covered by the signal of the originating station. They may serve, for example, to expand the broadcast range of a television or radio station beyond the primary signal's coverage area, or to improve service in a part of the main coverage area which receives a poor signal due to geographic constraints. They may be (but are not usually) used to create a single-frequency network
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.-Overview:...

.

Less commonly, a rebroadcaster may be owned by a community group rather than the owner of the primary station.

Broadcast translators


In its simplest form, a broadcast translator is a facility created to receive a terrestrial broadcast station 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) not adequately covered by a station's main signal.

Boosters and distributed transmission


Relays which broadcast within or very near the parent station's coverage area (a "fill-in") on the same channel or frequency are called "booster" stations in the U.S. However, this can be tricky because it is possible to have both stations interfering with each other unless they are carefully designed. Radio interference
Co-channel interference
Co-channel interference or CCI is crosstalk from two different radio transmitters using the same frequency. There can be several causes of co-channel radio interference; four examples are listed here....

 can be avoided by using exact atomic time obtained from GPS satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

s to perfectly synchronise co-channel stations, as in a single-frequency network
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.-Overview:...

.

US AM broadcasting
AM broadcasting
AM broadcasting is the process of radio broadcasting using amplitude modulation. AM was the first method of impressing sound on a radio signal and is still widely used today. Commercial and public AM broadcasting is carried out in the medium wave band world wide, and on long wave and short wave...

 stations do not have translators or boosters; though an SFN is actually easier to create in their frequency band, it is largely unnecessary as the longer wavelengths of these signals are more able to provide adequate coverage over longer distances despite a lack of line-of-sight
Line-of-sight propagation
Line-of-sight propagation refers to electro-magnetic radiation or acoustic wave propagation. Electromagnetic transmission includes light emissions traveling in a straight line...

 transmission conditions.

Analog TV stations cannot have same-channel boosters unless opposite (perpendicular
Perpendicular
In geometry, two lines or planes are considered perpendicular to each other if they form congruent adjacent angles . The term may be used as a noun or adjective...

) polarisation is used, due to video
Video
Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.- History :...

 synchronization
Synchronization
Synchronization is timekeeping which requires the coordination of events to operate a system in unison. The familiar conductor of an orchestra serves to keep the orchestra in time....

 issues such as ghosting
Ghosting
Ghosting may refer to:* ghosting , a form of identity theft, whereby a person takes on the identity of a deceased person* ghosting , a double image when receiving a distorted or multipath input signal in analog television broadcasting* motion blur, "ghosting" is a term often used when slow response...

. In the US, no new on-channel UHF signal boosters have been authorized since July 11, 1975.

Distributed transmission (DTx) is the use of several medium-power stations (usually digital) on the same frequency to cover a broadcast area, rather than one high-power station with any repeaters on a different frequency. Digital TV stations are technically capable of sharing a channel, however this is more difficult with the 8VSB
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....

 modulation
Modulation
In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...

 and invariable guard interval
Guard interval
In telecommunications, guard intervals are used to ensure that distinct transmissions do not interfere with one another. These transmissions may belong to different users or to the same user ....

 used in the ATSC
ATSC
ATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks....

 standard than with COFDM used in the European and Australian DVB-T
DVB-T
DVB-T is an abbreviation for Digital Video Broadcasting — Terrestrial; it 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 the UK in 1998...

 standard. A distributed transmission system
Distributed transmission system
In North American digital terrestrial television broadcasting, a distributed transmission system is a form of single-frequency network in which a single broadcast signal is fed via microwave, landline, or communications satellite to multiple synchronised terrestrial radio transmitter sites...

 would therefore have tight synchronisation requirements which require all transmitters to receive signal from one central source for broadcast at one exact GPS-synchronised
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...

 time. DTS (or DTx) are not broadcast repeaters in the conventional sense as they cannot simply receive the signal of one main terrestrial broadcast transmitter for rebroadcast; to do so would introduce a retransmission delay which breaks the precise synchronisation required, causing interference between individual transmitters.

The use of virtual channel
Virtual channel
In telecommunications, a logical channel number , also known as virtual channel, is a channel designation which differs from that of the actual radio channel on which the signal travels....

s is another alternative, though this may cause the same channel to appear multiple times on a receiver (once for each relay station), and requires the user to tune manually to the best one (which changes due to radio propagation
Radio propagation
Radio propagation is the behavior of radio waves when they are transmitted, or propagated from one point on the Earth to another, or into various parts of the atmosphere...

 conditions like weather
Weather
Weather is the state of the atmosphere, to the degree that it is hot or cold, wet or dry, calm or stormy, clear or cloudy. Most weather phenomena occur in the troposphere, just below the stratosphere. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate...

). Use of boosters or DTx instead causes all relay stations to ideally appear as a single signal, but requires significant broadcast engineering
Broadcast engineering
Broadcast engineering is the field of electrical engineering, and now to some extent computer engineering and information technology, which deals with radio and television broadcasting...

 to work properly and not cause destructive interference to each other's signals.

Satellite stations


Some fully licensed stations simply simulcast
Simulcast
Simulcast, shorthand for "simultaneous broadcast", refers to programs or events broadcast across more than one medium, or more than one service on the same medium, at the same time. For example, Absolute Radio is simulcast on both AM and on satellite radio, and the BBC's Prom concerts are often...

 another station. These are relay stations only in name and are generally licensed the same as any other major station. This is not regulated in the U.S., and it is also widely allowed in Canada, which otherwise the U.S. Federal Communications Commission
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...

 (FCC) regulates radio format
Radio format
A radio format or programming format not to be confused with broadcast programming describes the overall content broadcast on a radio station. Radio formats are frequently employed as a marketing tool, and constantly evolve...

s to ensure a diverse variety of programming.

US satellite stations may request that the Federal Communications Commission
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...

 (FCC) grant an exemption to requirements that a properly staffed broadcast studio be maintained in the city of license
City of license
A city of license or community of license, in American and Canadian broadcasting, is the community that a radio station or television station is officially licensed to serve by that country's broadcast regulator....

 or (in rural states) that television programming be simulcast in both analogue and digital
ATSC
ATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks....

 during digital television transition
DTV transition in the United States
The DTV transition in the United States was the switchover from analog to exclusively digital broadcasting of free over-the-air television programming...

. These stations most often cover vast, sparsely populated regions (an economic hardship) or are operated as statewide non-commercial educational
Educational television
Educational 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 is often associated with cable television in the United States as Public, educational, and government access ...

 radio and television
Public Broadcasting Service
The Public Broadcasting Service is an American non-profit public broadcasting television network with 354 member TV stations in the United States which hold collective ownership. Its headquarters is in Arlington, Virginia....

 systems.

Semi-satellites


A television rebroadcaster often sells local or regional advertising
Advertising
Advertising is a form of communication used to persuade an audience to take some action with respect to products, ideas, or services. Most commonly, the desired result is to drive consumer behavior with respect to a commercial offering, although political and ideological advertising is also common...

 for broadcast only on the local transmitter, and may also air a very limited amount of distinct programming from their parent station. Some such "semi-satellites" broadcast their own local newscasts, or separate news segments during part of the newscast. For example, CHEX-TV-2
CHEX-TV-2
CHEX-TV-2, branded as Channel 12 Durham , is a CBC-affiliated television station in Oshawa, Ontario, Canada, serving the Durham Region. The station's affiliation is despite the fact the Durham region is within the broadcast area of Toronto's CBLT...

 in Oshawa, Ontario
Oshawa, Ontario
Oshawa is a city in Ontario, Canada, on the Lake Ontario shoreline. It lies in Southern Ontario approximately 60 kilometres east of downtown Toronto. It is commonly viewed as the eastern anchor of both the Greater Toronto Area and the Golden Horseshoe. It is now commonly referred to as the most...

 airs separate daily late afternoon-early evening news and community broadcasts from its parent station, CHEX-TV
CHEX-TV
CHEX-TV is a television station in Peterborough, Ontario, Canada, and an affiliate of the CBC Television network. It began broadcasting on March 26, 1955, with an NHL ice hockey game. The station broadcasts over-the-air on channel 12.- History :...

 in Peterborough, Ontario
Peterborough, Ontario
Peterborough is a city on the Otonabee River in southern Ontario, Canada, 125 kilometres northeast of Toronto. The population of the City of Peterborough was 74,898 as of the 2006 census, while the census metropolitan area has a population of 121,428 as of a 2009 estimate. It presently ranks...

, Canada. The U.S. FCC prohibits this on FM translator stations, only allowing it on different fully licensed stations.

National networks


Most broadcasters outside of North America maintain a national network and use several relay transmitters to provide the same service to a region or entire nation. In comparison to the other types of relays explained above, the transmitter network is often created and maintained by an independent authority, often paid for using license fee
License fee
License fee may mean:*a fee paid for a license in general*a fee paid for a television licence...

s, and multiple major broadcasters use the same transmitters.

Canada


In Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, "rebroadcaster" or "rebroadcasting transmitter" are the terms most commonly used by the Canadian Radio-television and Telecommunications Commission.

Television


A television rebroadcaster may be permitted to sell local or regional advertising
Advertising
Advertising is a form of communication used to persuade an audience to take some action with respect to products, ideas, or services. Most commonly, the desired result is to drive consumer behavior with respect to a commercial offering, although political and ideological advertising is also common...

 for broadcast only on the local transmitter. On rarer occasions, they may also air a very limited amount of distinct programming from their parent station. Some such "semi-satellites" broadcast their own local newscasts, or separate news segments during part of the newscast.

There is no strict rule for the call sign
Call sign
In broadcasting and radio communications, a call sign is a unique designation for a transmitting station. In North America they are used as names for broadcasting stations...

 of a television rebroadcaster. Some transmitters have distinct call signs from the parent station (for example, CFGC in Sudbury is a rebroadcaster of CIII
CIII-TV
CIII-DT-41 is a television station owned by Shaw Communications that serves much of the population of the Canadian province of Ontario. It is a flagship station of the Global Television Network...

), while others use the call sign of the originating station followed by a number (e.g., CBLFT-17 in Sarnia
Sarnia, Ontario
Sarnia is a city in Southern Ontario, Canada . It is the largest city on Lake Huron and is located where the upper Great Lakes empty into the St. Clair River....

). Officially, the latter type includes the television station's TV suffix between the call sign and the number, although in media directories this is often left out for convenience.

In the latter case, the numbers are usually applied sequentially, starting from one and denoting the chronological order in which the station's rebroadcast transmitters began operation. Some broadcasters may, at their discretion, use a system in which the number denotes the actual broadcast channel of the transmitter (e.g., CJOH-TV-47
CJOH-TV
CJOH-DT is a television station serving Ottawa, Ontario, Canada, and the surrounding region. Owned by Bell Media, it is part of the CTV Television Network....

 in Pembroke
Pembroke, Ontario
Pembroke is a city in the province of Ontario, Canada, at the confluence of the Muskrat River and the Ottawa River in the Ottawa Valley...

). A broadcaster cannot, however, mix the two numbering systems under a single call sign — the transmitters are either all numbered sequentially or all numbered by their analogue channel position. On the rare occasion that the sequential numbering reaches 99 (e.g., TVOntario
TVOntario
TVOntario, often referred to only as TVO , is a publicly funded, educational English-language television station and media organization in the Canadian province of Ontario. It is operated by the Ontario Educational Communications Authority, a Crown corporation owned by the Government of Ontario...

's broadcast transmitters), rather than being numbered as 100 the next transmitter is assigned a new call sign and numbered as one. Translators which share the same frequency (such as CBLT's repeaters CBLET, CBLHT, CBLAT-2 and CH4113, all on channel 12) are also given distinct call signs.

Low-power
Low-power broadcasting
Low-power broadcasting is electronic broadcasting at very low power and low cost, to a small community area.The terms "low-power broadcasting" and "micropower broadcasting" should not be used interchangeably, because the markets are not the same...

 rebroadcasters may also have a call sign which consists of the letters CH followed by four numbers. For example, CH2649 in Valemount
Valemount, British Columbia
Valemount is a village of 1,018 people in east central British Columbia, Canada. It is situated between the Rocky, Monashee, and Cariboo Mountains. It is the nearest community to the west of Jasper National Park, and is also the nearest community to Mount Robson Provincial Park, which features...

 is a rebroadcaster of Vancouver
Vancouver
Vancouver is a coastal seaport city on the mainland of British Columbia, Canada. It is the hub of Greater Vancouver, which, with over 2.3 million residents, is the third most populous metropolitan area in the country,...

's CHAN
CHAN-TV
CHAN-DT is a television station in Vancouver, British Columbia, Canada, broadcasting over-the-air on digital channel 22, and available via cable providers in the area on channel 11. Owned by Shaw Communications as a part of its Shaw Media division, it is the West Coast flagship station of the...

. Rebroadcasters of this type are numbered strictly sequentially to the order in which they were licensed by the CRTC, and their call signs have no inherent relationship to those of the parent stations or of other rebroadcasters. Although the next number in the sequence, CH2650 in Anzac
Anzac, Alberta
Anzac is a hamlet in northern Alberta, Canada within the Regional Municipality of Wood Buffalo. It is located on Highway 881 along the east shore of Gregoire Lake, approximately southeast of Fort McMurray....

, is also a rebroadcaster of CHAN, this is simply because CH2649 and CH2650 happened to be licensed simultaneously — the following number, CH2651, is a rebroadcaster (also in Anzac) of Edmonton
Edmonton
Edmonton is the capital of the Canadian province of Alberta and is the province's second-largest city. Edmonton is located on the North Saskatchewan River and is the centre of the Edmonton Capital Region, which is surrounded by the central region of the province.The city and its census...

's CITV
CITV-TV
CITV-DT is a television station in Edmonton, Alberta, Canada. Known on air as Global Edmonton, the station is owned by Shaw Media, and is an owned-and-operated station of the Global Television Network. It transmits on channel 13 and cable 8 in Edmonton, and is carried on the Bell TV and Shaw...

. A single station's rebroadcasters are not necessarily all named in the same manner. CBLT, for example, has some retransmitters which have their own call signs, some which use CBLT followed by a number and some transmitters with CH numbers.

Radio


As in television, a radio rebroadcaster may have either a distinct call sign or the call sign of the originating station followed by a numeric suffix. In the case of radio, however, the numeric suffix is always sequential.

For a rebroadcaster of an FM station, the numeric suffix is appended to the FM suffix. For example, rebroadcasters of CJBC-FM
CJBC-FM
CJBC-FM is a Canadian radio station, broadcasting at 90.3 FM in Toronto, Ontario. A French language station, it airs the programming of Radio-Canada's Espace musique network.The station launched in 1992...

 in Toronto
Toronto
Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...

 are numbered CJBC-FM-1, CJBC-FM-2, etc. Where an AM station has a rebroadcaster operating on the FM band, the numeric suffix instead falls between the four-letter call sign and the FM suffix — for example, CKSB-1-FM is an FM rebroadcaster of the AM station CKSB
CKSB (AM)
CKSB is a Canadian radio station, broadcasting at 1050 AM and 90.5 FM in Winnipeg, Manitoba. It is an affiliate of Radio-Canada's Première Chaîne network.-History:...

, while CKSB-FM-1 would be a rebroadcaster of CKSB-FM
CKSB-FM
CKSB-FM is a Canadian radio station, broadcasting at 89.9 FM in Winnipeg, Manitoba. It is an affiliate of Radio-Canada's Espace musique network. The station launched in 2001....

.

As a broadcaster is limited to no more than two stations on one radio band in a market, one possible means to obtain a third FM signal in-market is to use a rebroadcaster of the AM station to move that signal onto low-power FM. In Sarnia, Ontario
Sarnia, Ontario
Sarnia is a city in Southern Ontario, Canada . It is the largest city on Lake Huron and is located where the upper Great Lakes empty into the St. Clair River....

, Blackburn Radio
Blackburn Radio
Blackburn Radio 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 Investments....

 already owns CFGX-FM
CFGX-FM
CFGX-FM is a Canadian radio station, which broadcasts at 99.9 FM in Sarnia, Ontario. The station broadcasts a soft adult contemporary format with the brand name The Fox.CFGX-FM can be heard in the eastern parts of Michigan...

 99.9 and CHKS-FM
CHKS-FM
CHKS-FM is a Canadian radio station, which broadcasts at 106.3 FM in Sarnia, Ontario. The station broadcasts an active rock format with the brand name K106.3.CHKS-FM can be received deep down inside parts of Eastern Michigan, as far in as Flint, Michigan...

 106.3; its third Sarnia station CHOK
Chok
Chok may refer to:*A Singaporean masculine given name:** Goh Chok Tong , second Prime Minister of the Republic of Singapore** Lionel Chok , Singaporean film-maker and director*Chok, a handwoven cloth from Central Thailand...

 1070 uses an FM repeater for in-city coverage as "Country 103.9" FM, although officially the AM signal remains the station's primary transmitter.

Low-power radio rebroadcasters may also have a call sign which consists of the letters VF followed by four numbers. 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
In U.S. broadcast law, a special temporary authorization or special temporary authority is a type of broadcast license which temporarily allows a broadcast station to operate outside of its normal technical or legal parameters...

) sometimes granted to newer campus
Campus radio
Campus radio is a type of radio station that is run by the students of a college, university or other educational institution. Programming may be exclusively by students, or may include programmers from the wider community in which the radio station is based...

 and community radio
Community radio
Community radio is a type of radio service, that offers a third model of radio broadcasting beyond commercial broadcasting and public broadcasting. Community stations can serve geographic communities and communities of interest...

 operations, may have another distinct class of call sign which consists of three letters from anywhere within Canada's ITU prefix range followed by three digits — e.g. CFU758 or VEK565. Some other stations within this license class, however, have been assigned conventional Cxxx call signs.

Occasionally, former rebroadcasters have been converted to originating stations in their own right, but have retained their former call sign instead of being reassigned a new one of their own. Such stations include CITE-FM-1
CITE-FM-1
CITE-FM-1 is a French-language Canadian radio station located in Sherbrooke, Quebec.Owned and operated by Astral Media, it broadcasts on 102.7 MHz with an effective radiated power of 100,000 watts using an omnidirectional antenna...

 in Sherbrooke, CBF-FM-8
CBF-FM-8
CBF-FM-8 is a French-language Canadian radio station located in Trois-Rivières, Quebec.Owned and operated by public broadcaster Canadian Broadcasting Corporation as part of the French-language Société Radio-Canada system, it broadcasts on 96.5 MHz using a directional antenna with an average...

 in Trois-Rivières
Trois-Rivières
Trois-Rivières means three rivers in French and may refer to:in Canada*Trois-Rivières, the largest city in the Mauricie region of Quebec, Canada*Circuit Trois-Rivières, a racetrack in Trois-Rivières, Quebec...

 and CBAF-FM-15
CBAF-FM-15
CBAF-FM-15 is a French-language Canadian radio station located in Charlottetown, Prince Edward Island.Owned and operated by the Canadian Broadcasting Corporation , it broadcasts on 88.1 MHz using a directional antenna with an average effective radiated power of 33,500 watts and a peak effective...

 in Charlottetown
Charlottetown
Charlottetown is a Canadian city. It is both the largest city on and the provincial capital of Prince Edward Island, and the county seat of Queens County. Named after Queen Charlotte, the wife of George III, Charlottetown was first incorporated as a town in 1855 and designated as a city in 1885...

.

Mexico


In Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

, translator and booster stations are given the callsign of the parent station plus a sequential number, such as XHABC and XHABC1, XHABC2.

Television


The majority of full-power television stations in Mexico are operated as repeaters or semi-satellites of the major Televisa
Televisa
Televisa is a Mexican multimedia conglomerate, the largest mass media company in Latin America and in the Spanish-speaking world. It is a major international entertainment business, with much of its programming airing in the United States on Univision, with which it has an exclusive contract...

 and TV Azteca
TV Azteca
Azteca, is the second largest Mexican television entertainment. It was established in 1983 as the state-owned Instituto Mexicano de la Televisión , a holding of the national TV networks channel 13 and 7 and was privatized under its current name in 1993 and now is part of Grupo Salinas...

 stations in Mexico City
Mexico City
Mexico City is the Federal District , capital of Mexico and seat of the federal powers of the Mexican Union. It is a federal entity within Mexico which is not part of any one of the 31 Mexican states but belongs to the federation as a whole...

; the largest of these repeater chains rebroadcasts XEW-TV
XEW-TV
XEW-TV is the call sign assigned to channel 2, a television station in Mexico City, Mexico. The station is owned by Televisa and is the flagship station to the Canal de las Estrellas network. XEW is second oldest Televisa and Mexico City's station, founded in 1951.-References:...

 programming on more than a hundred stations nationwide. The National Polytechnic Institute
National Polytechnic Institute
The National Polytechnic Institute colloquially known as the Polytechnic is one of the largest public universities in Mexico with 153.027 students at the high school, undergraduate and postgraduate levels...

's Once TV
Once TV
Once TV México, Spanish for México Eleven TV is a Mexican educational broadcast television network owned by Instituto Politecnico Nacional. The network's flagship station is XEIPN channel 11 in Mexico, Distrito Federal. It broadcasts across Mexico through local television affiliates, cable...

 and Monterey, Mexico-based Multimedios are also commonly rebroadcast nationally; individual Mexican states each operate a chain of full-power repeaters in-state to provide public educational television
Educational television
Educational 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 is often associated with cable television in the United States as Public, educational, and government access ...

.

Full-power rebroadcasters are issued callsigns in the same manner as all other stations; the callsign itself does not identify the originating station. As there are four Televisa
Televisa
Televisa is a Mexican multimedia conglomerate, the largest mass media company in Latin America and in the Spanish-speaking world. It is a major international entertainment business, with much of its programming airing in the United States on Univision, with which it has an exclusive contract...

 and three TV Azteca
TV Azteca
Azteca, is the second largest Mexican television entertainment. It was established in 1983 as the state-owned Instituto Mexicano de la Televisión , a holding of the national TV networks channel 13 and 7 and was privatized under its current name in 1993 and now is part of Grupo Salinas...

 stations in Mexico City alone, ownership of an individual transmitter by one of these groups does not in and of itself identify which signal the station is rebroadcasting. Transmitters rebroadcasting México City stations into Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...

 and other communities along the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 coast normally operate on a two-hour delay relative to the originating station.

The smallest repeaters are operated by municipal-level organisations; these bear standard callsigns and license but are registered to a local translator authority (typically «Patronato pro TV», «Comité Patronato Municipal pro TV» or «Comité Civil pro Ant. Retrans. de T.V.» followed by the name of a municipality) and licensed for small amounts of power - often operating at a hundred watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...

s or less. The largest repeaters are full-power satellite stations operated by national networks Televisa
Televisa
Televisa is a Mexican multimedia conglomerate, the largest mass media company in Latin America and in the Spanish-speaking world. It is a major international entertainment business, with much of its programming airing in the United States on Univision, with which it has an exclusive contract...

 and TV Azteca
TV Azteca
Azteca, is the second largest Mexican television entertainment. It was established in 1983 as the state-owned Instituto Mexicano de la Televisión , a holding of the national TV networks channel 13 and 7 and was privatized under its current name in 1993 and now is part of Grupo Salinas...

. There is no legal distinction between translators and originating stations.

Radio


As of July 2009, the basic Federal Communications Commission
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...

 (FCC) regulation
Regulation
Regulation is administrative legislation that constitutes or constrains rights and allocates responsibilities. It can be distinguished from primary legislation on the one hand and judge-made law on the other...

s on translators are:
  • FM translators may be used for cross-band translation. This removes the restriction that prevented FM translators from retransmitting AM signals.
  • No translator or booster may transmit anything other than the live simulcast
    Simulcast
    Simulcast, shorthand for "simultaneous broadcast", refers to programs or events broadcast across more than one medium, or more than one service on the same medium, at the same time. For example, Absolute Radio is simulcast on both AM and on satellite radio, and the BBC's Prom concerts are often...

     of its licensed parent station, except for emergency warnings (such as EAS
    Emergency Alert System
    The Emergency Alert System is a national warning system in the United States put into place on January 1, 1997, when it superseded the Emergency Broadcast System , which itself had superseded the CONELRAD System...

    ), and 30 seconds per hour of fundraising.
  • The parent station must identify
    Station identification
    Station identification is the practice of radio or television stations or networks identifying themselves on air, typically by means of a call sign or brand name...

     all of its translators and boosters between 7 and 9 a.m., between 12:55 and 1:05 p.m., and between 4 and 6 p.m. each broadcast day; or each must be equipped with its own automated device
    Information appliance
    In general terms, an information appliance or information device is any machine or device that is usable for the purposes of computing, telecommunicating, reproducing, and presenting encoded information in myriad forms and applications....

     (audio or FSK
    Frequency-shift keying
    Frequency-shift keying is a frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a carrier wave. The simplest FSK is binary FSK . BFSK uses a pair of discrete frequencies to transmit binary information. With this scheme, the "1" is called...

    ) for hourly identification.
  • Maximum power is 250 watt
    Watt
    The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...

    s ERP
    Effective radiated power
    In radio telecommunications, effective radiated power or equivalent radiated power is a standardized theoretical measurement of radio frequency energy using the SI unit watts, and is determined by subtracting system losses and adding system gains...

     for a translator, and 20% of the maximum allowable ERP for the primary station's class for a booster. There is no limit on height for fill-in translators (those that exist within the primary service contour of the primary station).
  • A translator or booster must go off the air if the parent station's signal is lost. (This helps prevent unauthorized retransmission of other stations).


There is one loophole by which programming may differ between a main station and an FM translator: an HD Radio
HD Radio
HD Radio, which originally stood for "Hybrid Digital", is the trademark for iBiquity's in-band on-channel digital radio technology used by AM and FM radio stations to transmit audio and data via a digital signal in conjunction with their analog signals...

 signal may contain digital subchannel
Digital subchannel
In broadcasting, digital subchannels are a means to transmit more than one independent program at the same time from the same digital radio or digital television station on the same radio frequency channel. This is done by using data compression techniques to reduce the size of each individual...

s with different programming from the main analogue channel, and a translator may operate in such a way as to broadcast programming taken from the originating station's HD2 subchannel as the translator's main analogue signal. W237DE (95.3 Harrisburg, Pennsylvania
Harrisburg, Pennsylvania
Harrisburg is the capital of Pennsylvania. As of the 2010 census, the city had a population of 49,528, making it the ninth largest city in Pennsylvania...

) broadcasts the programming format formerly carried by WTCY
WTCY
WHGB is a radio station broadcasting an sports format. Licensed to Harrisburg, Pennsylvania, it serves the greater Harrisburg metropolitan area. It first began broadcasting under the call sign WFEC. The station is currently owned by Cumulus Media and features sports programming from ESPN Radio...

 AM 1400, but it actually gets this signal from a WNNK
WNNK
WNNK-FM is a hot adult contemporary music formatted radio station serving the Harrisburg, Pennsylvania, area. Its studio is located in Linglestown, Pennsylvania and its transmitter is located on an Antenna farm alongside WHTM-TV in Enola, Pennsylvania.-History:Wink 104 actually began life with the...

 (104.1 FM) HD2 digital subchannel for analogue rebroadcast at the WNNK tower site on 95.3's main signal. As such, it technically is still legally an FM repeater of an FM station, even though each signal would be heard as delivering unique content by users of standard analogue FM radio receivers.

Commercial stations may own their translators or boosters when that translator or booster exists within the primary service contour of the parent station (they can only fill in where terrain
Terrain
Terrain, or land relief, is the vertical and horizontal dimension of land surface. When relief is described underwater, the term bathymetry is used...

 blocks the signal). In fact, boosters may only be owned by the primary station. Translators outside of a primary station's service contour cannot be owned by the primary station, nor can they receive any financial support from the primary station. Most translators operate by picking-up the signal of the main station off the air with a directional antenna and sensitive receiver, and directly retransmitting the signal. They also may not transmit in the FM "reserved band" from 88 to 92 MHz, where only noncommercial
Non-commercial educational
The term non-commercial educational applies to a radio station or TV station that does not accept on air advertisements , as defined in the United States by the Federal Communications Commission . NCE stations do not pay broadcast license fees for their non-profit uses of the radio spectrum...

 stations are allowed. Noncommercial stations may broadcast in the commercial band, however. Unlike commercial stations, they can also relay programming to translators via satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

, so long as those translators are in the reserved band. Translators in the commercial band may only be fed by a direct off-the-air signal from another FM station or translator. Non-fill-in commercial band translators may not be fed by satellite, as spelled out in FCC rule 74.1231(b). All stations may use any means to feed boosters.

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 any interference
Interference (communication)
In communications and electronics, especially in telecommunications, interference is anything which alters, modifies, or disrupts a signal as it travels along a channel between a source and a receiver. The term typically refers to the addition of unwanted signals to a useful signal...

 from full-power (100-watt or more on FM) stations, while not causing any of their own. Boosters must not interfere with the parent station within the community of license. Licenses are automatically renewed with that of the parent station and do not require separate applications, though each may still be challenged with a petition to deny.

FM booster stations are given the full callsign (always including an -FM suffix
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 or adjectives, and verb endings, which form the conjugation of verbs...

, even if there is none assigned) of the parent station, plus a serial number
Serial number
A serial number is a unique number assigned for identification which varies from its successor or predecessor by a fixed discrete integer value...

, such as WRIF1, WXYZ-FM2, etc.

FM translator stations may use sequential numbered callsigns, consisting of K or W, followed by a three-digit number (201 through 300 corresponding to frequencies 88.1 MHz - 107.9 MHz) followed by a pair of sequentially assigned letters. The format is similar to that used by numbered TV translators, where the number refers to the permanent channel assignment.

As of October 2008 the largest terrestrial radio translator system in the US belongs to KUER-FM
KUER-FM
KUER-FM is a public radio station licensed to the University of Utah in Salt Lake City, Utah. Broadcasting at 90.1 MHz FM, KUER is a National Public Radio -member station, also airing shows distributed by Public Radio International and American Public Media...

, the non-commercial radio outlet of the University of Utah
University of Utah
The University of Utah, also known as the U or the U of U, is a public, coeducational research university in Salt Lake City, Utah, United States. The university was established in 1850 as the University of Deseret by the General Assembly of the provisional State of Deseret, making it Utah's oldest...

, with 33 translator stations ranging from Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....

 to New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

 and Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

.

Television


Unlike FM, LPTV stations may operate as either translators or originate their own programming.

Translator stations in the U.S. are given callsigns which begin with a W or K (respectively east or west of the Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

, as with regular stations), followed by a channel number, and two serial letter
Serial number
A serial number is a unique number assigned for identification which varies from its successor or predecessor by a fixed discrete integer value...

s for each channel. (The first stations on that channel are AA, AB, AC, and so on.) Television channels are always two-digit, from 02 to 51 (formerly 02 to 83); while FM radio channels are from 200 (87.9 MHz) to 300 (107.9 MHz), one every 0.2 MHz. (Examples: W42BD, K263AF). The presence of an X after the number in these callsigns does not indicate an experimental broadcasting license as it may in other services, as all 26 letters are included in the sequence. The highest pair of letters used, , is ZS (K13ZS-D is a translator of KTSC in Sargents, Colorado
Sargents, Colorado
Sargents is an unincorporated town and a U.S. Post Office located in Saguache County, Colorado, United States. The Sargents Post Office has the ZIP Code 81248.-See also:* List of cities and towns in Colorado* Saguache County, Colorado* State of Colorado...

).

Numbered translator stations (a format such as "W70ZZ") are typically low-power repeaters, often 100 watts or less on FM, and 1000 or less on TV. The former "translator band", UHF TV channels 70
Channel 70
Channel 70 has been removed from television use in 1983, but was formerly used by television stations in North America which broadcast on 806-812 MHz. In the United States, channels 70-83 served primarily as a "translator band" containing repeater transmitters to fill gaps in coverage for existing...

 through 83
Channel 83
Channel 83 was removed from television use in 1983. The highest frequency to have been used for NTSC-M terrestrial TV broadcasting, it was formerly used by a handful of television stations in North America which broadcast on 884-890 MHz...

, was originally occupied primarily by these low-powered translators. The combination of low power and high frequencies provided a very limited range for these broadcasts. This band was reallocated to cellular telephone services in the 1980s, with the handful of remaining transmitters from these channels moved to lower frequencies.

Full-power repeaters (such as WPBS-TV
WPBS-TV
WPBS-DT and WNPI-DT are a Public Broadcasting Service member Public television station serving northern New York. Originating in the Watertown/Potsdam region, its primary audience includes Kingston, Ottawa and most of eastern Ontario....

's identical twin transmitter WNPI-TV) are normally assigned -TV callsigns like those of any other full-power station. They do not bear numbered callsigns and must operate in the same manner as other full-power broadcasters. This simulcasting is generally not regulated by the FCC.

LPTV stations may also choose a regular four-letter callsign with an -LP suffix (shared with LPFM) for analog or -LD for digital, generally done only if the station originates programming. Class A television stations get -CA and -CD instead. Digital stations which use numerals get a -D suffix (as in W42BD-D). All of these are despite the fact the full-power digital TV 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 callsigns, which means it may be different from the virtual channel
Virtual channel
In telecommunications, a logical channel number , also known as virtual channel, is a channel designation which differs from that of the actual radio channel on which the signal travels....

 (the analog number).

Numbered broadcast translators which are moved permanently to another frequency are normally issued new callsigns to reflect the updated channel assignments. The same is not true of displaced translators using another frequency temporarily under special technical authority, For instance, K55KD
K55KD
K55KD is a low-power Class A television station in Van Nuys, California, broadcasting locally in analog on UHF channel 57. Founded on August 4, 1998 as a Santa Barbara station on UHF channel 66, K55KD is owned and operated by Almavision, and serves the Los Angeles area on channel 57 through Special...

 could retain its callsign while displaced temporarily to channel 57
Channel 57
Channel 57 refers to several television stations:...

 to resolve interference to MediaFLO
MediaFLO
MediaFLO is 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...

 users, while W81
Channel 81
Channel 81 has been used to refer to:* BBC Parliament, a digital television channel on the British Freeview terrestrial service.* A rarely-used NTSC-M channel, removed from television use in 1983 and originally used in North America for broadcast on 872-878 MHz...

AA would have received new calls when channel 81 was deleted from the bandplan. On the rare occasion a station moves back to its original channel, it is given its old callsign, as they are not reused by other stations like regular callsigns can be.
Digital transition

LPTV operations are not required to simulcast a digital signal, nor were they required to shut down analog operation in June 2009 when full-power US TV operators had to do so.

Full-power stations used to simulcast another station were, like other full-service television broadcasters, required to convert fully to digital in June 2009. The FCC defines these "TV satellite stations" as "full-power broadcast stations authorized under Part 73 of the Commission’s rules to retransmit all or part of the programming of a parent station that is typically commonly owned." As most satellite stations operate in small or sparsely populated areas that have an insufficient economic base to support full-service operations, many were granted FCC authorization on a case-by-case basis to flash-cut
Flash-cut
A flash-cut, also called flash-cutover, is an immediate change in a complex system, with no phase-in period.Some telephone area codes were split immediately, rather than being phased in with a permissive dialing period. An example is telephone area code 213, which was split into 213 and 714 all at...

 from analog to digital on the same channel instead of simulcasting in both formats during the digital transition.

, no current or future DTV mandates had been forced on LPTV stations, however Congress passed legislation to provide immediate funding so these low-power stations could switch to digital by the conversion date, or shortly thereafter.

For many LPTV operations, the creation of digital companion channels for full-power stations has already required that the low-power station relocate to another frequency. Once the digital transition was complete, additional LPTV broadcasters were forced onto lower channels as channel 52 through 69 were removed from television use at that time. Existing channel 55
Channel 55
Channel 55 refers to several television stations. This frequency is also in use by MediaFLO, a US system developed by Qualcomm to send video and media to mobile devices:...

 licensees, both low-power and full-power, were being encouraged to relocate early to free spectrum for Qualcomm's MediaFLO
MediaFLO
MediaFLO is 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...

 transmitters.

Many low-power broadcast translators also were directly affected by a parent station's conversion to digital television. Translators which received an analog over-the-air signal from a full-service TV station for rebroadcast needed to convert receiving equipment in much the same way that individual viewers needed to deploy digital converters. While the signal transmitted by the repeater may remain in analog format, the uplink had to be changed. In the United States, 23% of the 4000 licensed translators have received a $1000 federal government subsidy which covers a small portion of the cost of this additional equipment. Many other translators were expected to simply go dark
Dark (broadcasting)
In the broadcasting industry, dark is a term used to describe a radio station or television station that has gone off-the-air for an indefinite period of time, or as defined by the U.S. Federal Communications Commission , a "silent" station...

 after the digital transition deadline.

Some small translators operated by direct conversion of a parent station's signal to another frequency for rebroadcast, without any other local signal processing or demodulation. For example, W07BA, a 16-watt repeater for Syracuse, New York
Syracuse, New York
Syracuse is a city in and the county seat of Onondaga County, New York, United States, the largest U.S. city with the name "Syracuse", and the fifth most populous city in the state. At the 2010 census, the city population was 145,170, and its metropolitan area had a population of 742,603...

 broadcaster WSYR-TV
WSYR-TV
WSYR-TV is the ABC-affiliated television station for Central New York State that is licensed to Syracuse. It broadcasts a high definition digital signal on UHF channel 17 from a transmitter on Sevier Road in Pompey. The station can also be seen on Time Warner channel 9 and in high definition on...

, was by design a very simple piece of broadcast apparatus; it merely shifted the main station's signal from channel nine to channel seven to cover a small valley in Dewitt. After digital transition
DTV transition in the United States
The DTV transition in the United States was the switchover from analog to exclusively digital broadcasting of free over-the-air television programming...

, Syracuse became a UHF island and WSYR-TV's main ABC
American Broadcasting Company
The American Broadcasting Company is an American commercial broadcasting television network. Created in 1943 from the former NBC Blue radio network, ABC is owned by The Walt Disney Company and is part of Disney-ABC Television Group. Its first broadcast on television was in 1948...

 signal became a 100 kW digital broadcast on channel seventeen. Therefore there is no longer a channel nine signal in any format available to feed the tiny repeater. Translators in remote locations, where no commercial power is available, were also expected to have problems in deploying extra equipment to handle an uplink's digital conversion. While many translators continue analog broadcasts (and a minority transitioned to digital themselves), some distant rural communities expected to find all local translator signals gone as a result of originating stations' transition to digital. As an interim solution to this problem, communities that are permitted to do so by state and federal laws have chosen to purchase Ku-Band (Echostar, Hughes, etc.) or C-Band satellite receivers for their translator stations: the satellite input is simply re-broadcast as their analog translator output. Retransmitting the local channels from the satellite has the same problems as if the service area residents purchased individual service themselves: signal latency, atmospheric conditions (thick clouds or precipitation would scramble the signal although the translator is operating normally), satellite equipment issues, etc.

A digital-to-digital repeater or broadcast translator is possible; in North America the ATSC
ATSC
ATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks....

 specifications allow such repeaters to leave the virtual channel
Virtual channel
In telecommunications, a logical channel number , also known as virtual channel, is a channel designation which differs from that of the actual radio channel on which the signal travels....

 numbering and guide (PSIP) of the originating station unchanged, so that the rebroadcaster appears to the viewer as if it were on the same channel numbers as the original station. Some full-power television stations that have lost coverage after the digital transition have applied for digital replacement translators to fill in the gaps in some of the station's lost coverage. Those "fill-in" translators use the same call letters, suffix and facility IDs as their main full-power station.

Most digital TV sets and digital video recorder
Digital video recorder
A digital video recorder , sometimes referred to by the merchandising term personal video recorder , is a consumer electronics device or application software that records video in a digital format to a disk drive, USB flash drive, SD memory card or other local or networked mass storage device...

s include analog and digital tuner
ATSC tuner
An ATSC tuner, often called an ATSC receiver or HDTV tuner is a type of television tuner that allows reception of digital television television channels transmitted by television stations in North America, parts of Central America and South Korea that use ATSC standards...

s, however most DTV set-top box
Set-top box
A set-top box or set-top unit is an information appliance device that generally contains a tuner and connects to a television set and an external source of signal, turning the signal into content which is then displayed on the television screen or other display device.-History:Before the...

es fail to display analog stations or even to include analog passthrough
Analog passthrough
Analog passthrough is a feature found on some digital-to-analog television converter boxes. Boxes without analog passthrough only allow digital TV to be viewed on older, analog-only TVs...

 for RF from the TV antenna (the way a VCR does). This is an issue primarily with coupon-eligible converter box
Coupon-eligible converter box
A coupon-eligible converter box was a digital television adapter that met eligibility specifications for subsidy "coupons" from the United States government...

es and caused grave concern among LPTV operators and border stations; the Community Broadcasters Association
Community Broadcasters Association
The Community Broadcasters Association was a trade organization representing low-power broadcasting interests, including LPTV and Class A television stations, in the United States of America...

 filed a lawsuit
Lawsuit
A lawsuit or "suit in law" is a civil action brought in a court of law in which a plaintiff, a party who claims to have incurred loss as a result of a defendant's actions, demands a legal or equitable remedy. The defendant is required to respond to the plaintiff's complaint...

 claiming it violated the All-Channel Receiver Act, the law
Law
Law is a system of rules and guidelines which are enforced through social institutions to govern behavior, wherever possible. It shapes politics, economics and society in numerous ways and serves as a social mediator of relations between people. Contract law regulates everything from buying a bus...

 on which the FCC based its digital mandate. However, in late 2008, 58% of approved coupon-eligible converter models were providing analog pass-through.

Controversy


Under US law, full-service local broadcasters are the primary occupants of the FM radio broadcast band. All LPFM operations, as well as all translators, are considered to be secondary in importance. In theory, this leaves low-power FM stations and broadcast translators with co-equal status on the FM band. In practice, as the FM broadcast band becomes more crowded, frequencies assigned to translators become unavailable to new LPFM stations or to existing LPFM stations seeking to upgrade their facilities.

A few key distinctions often place small, local LPFM operators at a disadvantage:
  • The maximum power for an LPFM station (either 10 or 100 watt
    Watt
    The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...

    s, depending on class of station) is less than that of the largest FM broadcast translators (at 250 watts), limiting the reach of the LPFM signal.
  • The minimum spacing required (in distance and frequency) to other stations is less strict for translators than for LPFM applicants. While the translator spacing is based on signal contour levels (and therefore takes terrain and obstacles into account), the LPFM stations have a more restrictive legally defined minimum distance requirement.
  • An LPFM broadcaster is required to generate local content; if there are multiple applicants for the same frequency, those who agree to originate eight or more hours a day of local programming are favoured. Translators are not required to (and are not licensed to) originate anything locally.
  • LPFM licenses are normally issued to non-commercial educational entities (such as schools or municipalities) and are subject to strict requirements largely precluding multiple stations under common ownership. The same is not true of translators. A non-commercial translator with no local content and no educational content is free to occupy space even in the non-commercial segment (below 92 MHz) of the US FM broadcast band. During the narrow FCC filing windows for new applicants, multiple applications for broadcast translators from the same or related entities can be abused to request every locally available frequency in multiple communities.
  • An LPFM license or construction permit cannot lawfully be resold. The same is not true for translators. A few related entities can easily file applications for thousands of individual translator construction permits via automated means, using non-commercial status to gain exemption from any FCC filing fees, then resell these construction permits en masse or individually for thousands of dollars each - even if the corresponding transmitters have not yet been constructed.


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
Over-the-air has several meanings, depending on context. *Generally, over-the-air is synonymous for wireless.*Specifically, over-the-air can have the following meanings or is used in the following contexts:...

 and retransmit solely within the region which should be covered by the main station. (This eliminates the need for a translator except in cases where the terrain shielding is a problem.) This same restriction does not apply to non-commercial educational
Non-commercial educational
The term non-commercial educational applies to a radio station or TV station that does not accept on air advertisements , as defined in the United States by the Federal Communications Commission . NCE stations do not pay broadcast license fees for their non-profit uses of the radio spectrum...

 stations. Any non-commercial station, even one with no local or educational content to offer, can apply for an unlimited number of translators anywhere to be fed by any means (including via satellite). The end result is a network of hundreds of small local transmitters, none of which broadcast (and none of which can lawfully broadcast) programming of interest to the local community. All take increasingly scarce available spectrum which otherwise could have been employed by local LPFM stations or used for rebroadcast of local full-service stations.

Another related issue involves the use of full-power stations to carry automated
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 operator...

 or satellite-originated programming. Any new full-service station can displace an existing low-power translator or an independent LPFM station; regulations allow this on the presumption that the full-service broadcaster would be more likely to provide a local voice to the community of license. Not all full-service broadcasters live up to this expectation. In some cases (such as the displacement of existing National Public Radio repeaters by newly created religious stations in Lake Charles, Louisiana
Lake Charles, Louisiana
Lake Charles is the fifth-largest incorporated city in the U.S. state of Louisiana, located on Lake Charles, Prien Lake, and the Calcasieu River. Located in Calcasieu Parish, a major cultural, industrial, and educational center in the southwest region of the state, and one of the most important in...

) the result has been the loss of local or educational content. While an exactly opposite outcome to that which legislative intent had anticipated, often a small non-commercial educational translator was carrying content of higher quality than a satellite-fed full-power station for which it is displaced.
Great Translator Invasion of 2003

An FCC licensing window for new translator applications in 2003 resulted in over 13,000 applications being filed, most of them coming from religious broadcasters. Due to the extremely high volume of license applications, LPFM advocates describe this as the Great Translator Invasion.

A few broadcasters have taken advantage of FM translator regulations which allow non-commercial stations to feed distant translators from satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

-delivered programming hundreds or even thousands of miles outside the parent station's coverage area. However, it is a misconception that all translators can be fed by satellites. Only translators located on the non-commercial portion of the FM band (88.1 to 91.9 MHz) can be so-called "Satellators". All other translators must be fed off the air by direct radio reception, except in the case of so called "fill-in" facilities that exist within the service contour of a primary station. Translators may also be used to feed other translators, so it is possible to create small chains of translators all fed from one distant station, however, this only works until the chain is broken and, if any one translator fails, the entire network beyond the failed translator goes down, too. The application window of 2003 resulted in so many applications, that the FCC was overloaded and issued an emergency hold order on new translator applications until the present batch can be sorted through; this came after considerable criticism from LPFM lobbyist groups such as Prometheus Radio. These translator applications were all on the commercial band and none of them can be used as satellators. It is unknown how the one broadcast group with the most applications planned to deliver programming to all of the translators, but affiliated churches of the parent organization own broadcasting outlets in many of the cities.

Some religious broadcasting
Religious broadcasting
Religious broadcasting refers to broadcasting by religious organizations, usually with a religious message. Many religious organizations have long recorded content such as sermons and lectures, and have moved into distributing content on their Internet websites.While this article emphasises...

 outlets — such as Calvary Chapel
Calvary Chapel
Calvary Chapel is an evangelical association of Christian churches with over one thousand congregations worldwide. Calvary Chapel also maintains a number of radio stations around the world and operates many local Calvary Chapel Bible College programs. It presents itself as a "fellowship of...

's KAWZ-
CSN International
CSN International, broadcasting under the callsign KAWZ, is an FM radio station in Twin Falls, Idaho, operating on a frequency of 89.9 MHz with an effective radiated power of 100 kW at 302 meters above average terrain....

Twin Falls, Idaho
Twin Falls, Idaho
Twin Falls is the county seat and largest city of Twin Falls County, Idaho, United States. The population was 44,125 at the 2010 censusTwin Falls is the largest city of Idaho's Magic Valley region...

, Educational Media Foundation
Educational Media Foundation
Educational Media Foundation is a not-for-profit organization that operates the K-LOVE and Air 1 radio networks. EMF is based in Rocklin, California....

 or Family Radio
Family Radio
Family Radio, also known by its licensee name Family Stations Inc., is a Christian radio network based in Oakland, California, USA, founded by Lloyd Lindquist, Richard H. Palmquist and Harold Camping...

's KEAR-FM
KEAR-FM
KEAR-FM 88.1 FM is a non-commercial traditional Christian radio station in Sacramento, California, which runs programming from Family Radio. Its transmitter is located in Walnut Grove, California. The station first went on the air in 1996 as KEDR, until October 17, 2005, when KEAR San Francisco...

-Sacramento
Sacramento, California
Sacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...

 – are relayed by hundreds of FM "translator" stations across the US. As these parent stations are owned by non-profit organizations and they exist on the non-commercial part of the spectrum, they are not required to have their translators receive their signal over the air, as would be required for a commercial broadcaster. This has been used by a number of religious broadcasters to set up large satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

-based networks composed almost entirely of "distant translators" – translators outside of the market area (generally a 50-mile radius surrounding the transmitter).

Some LPFM advocates erroneously state that the proliferation of translators has posed difficulties for non-translator station operators, in particular LPFM license applicants who claim that they cannot get stations on the air due to translators eliminating any available channels in an area. While this may be true for future LPFM applications, it is not true for any existing LPFM broadcasters or LPFM applicants. This is because the last LPFM filing window was in 2001. All translator applications from the 2003 window were required to protect the LPFM applications already pending or authorized at that time. As a result, no LPFM station was denied due to translators.

Since so-called sat-casting translators are only permitted on the non-commercial part of the spectrum, where LPFM stations do not exist, they pose no threat to the ability of existing LPFM licensees to expand their current station facilities. Non-sat-casting translators can sometimes present a problem for existing LPFM stations and the existence of a translator, theoretically, could leave LPFM stations who have been "bumped" from existing channel assignments by new full-power stations with no available frequency to which to move. The FCC has, generally, not required LPFM stations to be displaced by full power stations. In such cases, the LPFM may be subject to increased interference from the full-powered move-in, but the FCC has adopted a "Live and let live" policy that has been used to keep existing LPFM stations operating.

There is at least one proposed rulemaking that would revise the procedures by which nonprofit groups may apply for translators (thus disallowing more than a certain number of translator applications to be owned by any one entity); in addition, the FCC has modified channel requirements for LPFM broadcasters to open up channel space. REC Networks has filed a petition with the FCC that would, among other things, require the FCC to give higher priority to LPFM stations.
Satellite translator networks

Areas with no available FM spectrum for LPFM stations due to large distant translator networks include Chicago (with several Calvary Chapel and Educational Media Foundation stations), Atlanta
Atlanta, Georgia
Atlanta is the capital and most populous city in the U.S. state of Georgia. According to the 2010 census, Atlanta's population is 420,003. Atlanta is the cultural and economic center of the Atlanta metropolitan area, which is home to 5,268,860 people and is the ninth largest metropolitan area in...

 (with several Way-FM - associated with K-Love and Salem Communications - and Edgewater Broadcasting stations) and Dallas, Texas
Dallas, Texas
Dallas is the third-largest city in Texas and the ninth-largest in the United States. The Dallas-Fort Worth Metroplex is the largest metropolitan area in the South and fourth-largest metropolitan area in the United States...

 (with Calvary Satellite Network and American Family Radio). Even Louisville, Kentucky
Louisville, Kentucky
Louisville is the largest city in the U.S. state of Kentucky, and the county seat of Jefferson County. Since 2003, the city's borders have been coterminous with those of the county because of a city-county merger. The city's population at the 2010 census was 741,096...

 and Knoxville, Tennessee
Knoxville, Tennessee
Founded in 1786, Knoxville is the third-largest city in the U.S. state of Tennessee, U.S.A., behind Memphis and Nashville, and is the county seat of Knox County. It is the largest city in East Tennessee, and the second-largest city in the Appalachia region...

, both small market areas, have a complete lack of LPFM channels due to distant translator invasion by broadcasters such as Calvary Chapel and Way-FM.

The largest satellite-fed translator networks are endeavors linked to Calvary Chapel (including Radio Assist Ministries, Horizon Broadcasting, and (formerly) Edgewater Broadcasting and REACH Media) and American Family Radio owned by the American Family Association
American Family Association
The American Family Association is a 501 non-profit organization that promotes conservative Christian values, such as opposition to same-sex marriage, pornography, and abortion, as well as other public policy goals such as deregulation of the oil industry and lobbying against the Employee Free...

. The multiple networks associated with Calvary Chapel have been a particular focus in regard to translator-based networks. In many cases, multiple applications were submitted by different companies linked to Calvary Chapel in particular for the same channel. At least four separate radio stations operated by Calvary Chapel churches and relaying Calvary Satellite Network programming have been identified as "home stations" for distant translators and there are many home churches in addition to the main "national" Calvary Chapel concerns applying for licenses.

In the case of American Family Radio in particular, there are indications of a deliberate strategy to crowd out rebroadcasters of National Public Radio stations for political purposes.

Educational Media Foundation, owners of the K-Love contemporary Christian music
Contemporary Christian music
Contemporary Christian music is a genre of modern popular music which is lyrically focused on matters concerned with the Christian faith...

 radio network, have also been cited as applying for distant translators en masse.
Out-of-band translators

, the FCC officially sanctioned the use of FM translators for cross-band carriage of AM signals. although some feel that this poses a threat to LPFM stations, the FCC did not authorize the use of any new FM translators for this purpose and limited cross-band translation to existing translators that had already been authorized as of May 2009. Since no new translators were authorized, there is no increased threat to LPFMs from cross-band translation services The FCC also allows translation of HD Radio
HD Radio
HD Radio, which originally stood for "Hybrid Digital", is the trademark for iBiquity's in-band on-channel digital radio technology used by AM and FM radio stations to transmit audio and data via a digital signal in conjunction with their analog signals...

 digital-only channels as inputs for analog FM-only output.
Sale of permits

Some groups have sold their translator construction permit
Construction permit
A construction permit or building permit is a permit required in most jurisdictions for new construction, or adding on to pre-existing structures, and in some cases for major renovations. Generally, the new construction must be inspected during construction and after completion to ensure compliance...

s for a large profit
Profit (accounting)
In accounting, profit can be considered to be the difference between the purchase price and the costs of bringing to market whatever it is that is accounted as an enterprise in terms of the component costs of delivered goods and/or services and any operating or other expenses.-Definition:There are...

. Other licensees have sold their translator stations for large amounts of money — sometimes tens of thousands of dollars or more, and many times what it costs to build one.

Radio


Australia's national radio networks (Radio National
Radio National
ABC Radio National is an Australia-wide non-commercial radio network run by the Australian Broadcasting Corporation.Radio National broadcasts national programming in areas that include news and current affairs, the arts, social issues, science, drama and comedy...

, ABC NewsRadio
ABC NewsRadio
ABC NewsRadio is an Australian Broadcasting Corporation radio service devoted to delivering live and 24-hour news updates and information. The service is available on a number of broadcasts right around Australia, including AM/FM radio, some pay-TV platforms and online via the Internet.Originally...

, Triple J
Triple J
triple j is a nationally networked Australian radio station intended to appeal to listeners between the ages of 18 and 30. The government-funded station is a division of the Australian Broadcasting Corporation...

, ABC Classic FM
ABC Classic FM
ABC Classic FM is a classical music radio station available in Australia, and internationally online. It is operated by the Australian Broadcasting Corporation . It was established in 1976 as "ABC-FM", and later for a short time was known as "ABC Fine Music" , before adopting its current name...

 and SBS Radio
SBS Radio
SBS Radio is a service provided by the Special Broadcasting Service '..to inform, educate and entertain Australians, especially those of non-English speaking backgrounds'. SBS Radio originally began as two stations based in Melbourne and Sydney, set up to provide pre-recorded information about the...

) each have relay transmitters which allow each service to be broadcast as widely as possible. In order to provide this, the ABC and SBS both 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 the local geography (such as mountainous terrain) prevents them from broadcasting to their entire market.

Television


Since market aggregation in the early 1990s, each television broadcaster transmits its service using multiple relays in order provide the same service throughout Australia's large market areas. While each market is often divided into submarkets due to the legacy of previous commercial broadcasts (for example, Southern Cross Ten
Southern Cross Ten
Southern Cross Ten is an Australian television channel broadcast by the Macquarie Media Group in Queensland, New South Wales, the Australian Capital Territory, Victoria and South Australia. The channel is owned by the Macquarie Media Group as is affiliated to Network Ten...

 maintains two separate stations in the single Victoria market, GLV and BCV), the only difference between these submarkets in practice is limited to news services or 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 starting digital or HD
High-definition television
High-definition television is video that has resolution substantially higher than that of traditional television systems . HDTV has one or two million pixels per frame, roughly five times that of SD...

 services due to problems with certain regional transmitters.

Europe


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

See also

  • Airborne radio relay
    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.-Use in Vietnam:...

  • Amateur radio repeater
    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...

  • Communications satellite
    Communications satellite
    A communications satellite is an artificial satellite stationed in space for the purpose of telecommunications...

  • Cellular repeater
    Cellular repeater
    A cellular repeater, cell phone repeater, or wireless cellular signal booster, a type of bi-directional amplifier as commonly named in the wireless telecommunications industry, is a device used for boosting the cell phone reception to the local area by the usage of a reception antenna, a signal...

  • Microwave radio relay
  • Repeater
    Repeater
    A repeater is an electronic device that receives asignal and retransmits it at a higher level and/or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances.-Description:...

  • Radio repeater
    Radio repeater
    A radio repeater is a combination of a radio receiver and a radio transmitter that receives a weak or low-level signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. This article refers to professional, commercial, and...

  • Shortwave relay station
    Shortwave relay station
    Shortwave relay stations are transmitter sites used by international broadcasters to extend their coverage to areas that cannot be reached easily from their home state, for example the BBC operates an extensive net of relay stations....

  • Transmitter station
    Transmitter station
    Transmitter station refers to terrestrial infrastructure for transmitting radio frequency signals. The station maybe used for, wireless communication, broadcasting, microwave link, mobile telephone etc.-Choice of location:...

  • Television transmitter
    Television transmitter
    A television transmitter is a device which broadcasts an electromagnetic signal to the television receivers. Television transmitters may be analog or digital.- Types of transmitters :There are many types of transmitters depending on* The system standard...


External links