A telecommunication circuit is a path in a
telecommunications network used to
transmit information. Circuits have evolved over time from generally being built on physical connections between individual hardware cables, as in an analog phone switch, to
virtual circuits
A virtual circuit (VC) is a means of transporting data over a data network, based on packet switching and in which a connection is established within the network between two endpoints. The network, rather than having a fixed data rate reservation ...
established over
packet switching networks.
Definitions
A telecommunication circuit may be defined as follows:
* The complete path between two terminals over which one-way or two-way communications may be provided.
* An electronic path between two or more points, capable of providing a single or multiple
communication channels.
* An electronic closed-loop path among two or more points used for
signal transfer.
In operational terms, a telecommunication circuit may be capable of transmitting information in only one direction (''simplex'' circuit), or it may be bi-directional (''duplex'' circuit). Bi-directional circuits may support half-
duplex operation, when only one end of the channel transmits at any one time, or they may support full-duplex operation, when independent simultaneous transmission occurs in both directions.
Applications
Originally, telecommunication circuits transmitted
analog signals.
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 radio ...
s used them as
studio transmitter link
A studio transmitter link (or STL) sends a radio station's or television station's audio and video from the broadcast studio or origination facility to a radio transmitter, television transmitter or uplink facility in another location. This is ac ...
s (STLs) or as
remote pickup unit (RPU) for
sound reproduction
Sound recording and reproduction is the electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording ...
, sometimes as a
backup
In information technology, a backup, or data backup is a copy of computer data taken and stored elsewhere so that it may be used to restore the original after a data loss event. The verb form, referring to the process of doing so, is "back up", ...
to other means. Later lines were
digital
Digital usually refers to something using discrete digits, often binary digits.
Technology and computing Hardware
*Digital electronics, electronic circuits which operate using digital signals
** Digital camera, which captures and stores digital ...
, used in pair-gain applications, such as
carrier systems, or in enterprise
data network
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are m ...
s.
A
leased line
A leased line is a private telecommunications circuit between two or more locations provided according to a commercial contract. It is sometimes also known as a private circuit, and as a data line in the UK. Typically, leased lines are used by ...
, ''private circuit'', or ''dedicated circuit'', is a circuit that is dedicated to only one use and is typically not switched at a central office. The opposite is a switched circuit, which can be connected to different paths in a switching center or telephone exchange.
Plain old telephone service (POTS) and
ISDN telephone
A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into e ...
lines are switched circuits.
On certain
packet switching telecommunication circuits, a
virtual circuit may be created, while
sharing the physical circuit.
See also
*
Data transmission circuit
References
Further reading
*{{cite book, title=Telecommunication Circuit Design, author=Patrick D. van der Puije, year=2002, publisher=John Wiley & Sons, location=New York
Telecommunications equipment