A studio transmitter link (or STL) sends a

radio station Radio broadcasting is transmission of audio (sound), sometimes with related metadata, by radio waves to radio receivers belonging to a public audience. In terrestrial radio broadcasting the radio waves are broadcast by a land-based radi ...

's or

television station A television station is a set of equipment managed by a business, organisation or other entity, such as an amateur television (ATV) operator, that transmits video content and audio content via radio waves directly from a transmitter on the eart ...

audio Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound * Audio signal, an electrical representation of sound *Audio frequency, a frequency in the audio spectrum * Digital audio, representation of sou ...

and

video Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) syst ...

from the broadcast studio or origination facility to a

radio transmitter In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the ...

television transmitter A television transmitter is a transmitter that is used for terrestrial (over-the-air) television broadcasting. It is an electronic device that radiates radio waves that carry a video signal representing moving images, along with a synchronized ...

or uplink facility in another location. This is accomplished through the use of terrestrial microwave links or by using fiber optic or other telecommunication connections to the transmitter site. This is often necessary because the best locations for an antenna are on top of a mountain, where a much shorter

radio tower Radio masts and towers are typically tall structures designed to support antennas for telecommunications and broadcasting, including television. There are two main types: guyed and self-supporting structures. They are among the tallest human-made ...

is required, but where locating a studio may be impractical. Even in flat regions, the center of the station's allowed coverage area may not be near the studio location or may lie within a populated area where a transmitter would be frowned upon by the community, so the antenna must be placed at a distance from the studio. Depending on the locations that must be connected, a station may choose either a point to point (PTP) link on another special

radio frequency Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the ...

, or a newer all- digital wired link via a dedicated

data transmission circuit In telecommunication, a data transmission circuit is the transmission media and the intervening equipment used for the data transfer between data terminal equipment ( DTEs). A data transmission circuit includes any required signal conversion eq ...

. Radio links can also be digital, or the older

analog Analog or analogue may refer to: Computing and electronics * Analog signal, in which information is encoded in a continuous variable ** Analog device, an apparatus that operates on analog signals *** Analog electronics, circuits which use analog ...

type, or a

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

of the two. Even on older all-analog systems, multiple audio and data channels can be sent using subcarriers. Stations that employ an STL usually also have a ''transmitter/studio link'' (TSL) to return

telemetry Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', "remote", an ...

information. Both the STL and TSL are considered

broadcast auxiliary service A broadcast auxiliary service or BAS is any radio frequency system used by a radio station or TV station, which is not part of its direct broadcast to listeners or viewers. These are essentially internal-use backhaul channels not intended for ac ...

s (BAS).

Transmitter/studio link

The transmitter/studio link (or TSL) of a

is a

return link In communications systems, the return channel (also reverse channel or return link) is the transmission link from a user terminal to the central hub. Return links are often, but not always, slower than the corresponding forward links. Examples where ...

which sends

data from the remotely located

back to the studio for monitoring purposes. The TSL may return the same way as the STL, or it can be embedded in the station's regular broadcast

signal In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The '' IEEE Transactions on Signal Processing' ...

as a subcarrier (for analog stations) or a separate

data channel A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used for informat ...

(for digital stations). Analog or digital data such as transmitter

power Power most often refers to: * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power * Power (social and political), the ability to influence people or events ** Abusive power Power may a ...

, temperature,

VSWR In radio engineering and telecommunications, standing wave ratio (SWR) is a measure of impedance matching of loads to the characteristic impedance of a transmission line or waveguide. Impedance mismatches result in standing waves along the transmi ...

, voltage, modulation level, and other status information are returned so that

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. Audio engineering and RF engineering are also essential ...

staff can correct any problems as soon as possible. These data may be attended to by an

automated transmission system An automatic transmission system (ATS) is an automated system designed to keep a broadcast radio or television station's transmitter and antenna system running without direct human oversight or attention for long periods. Such systems are occasi ...

References

* CFR Title 47:

Telecommunication Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that fe ...

Part 74—Experimental Radio, Auxiliary, Special Broadcast and Other Program Distributional Services *CFR Title 47: Telecommunication Chapter I—Federal Communications Commission Subchapter C—Part 73—Broadcast Radio Services Broadcast transmitters Broadcast engineering Television terminology {{tv-stub

Transmitter/studio link

See also

References