A telecommunication circuit is an electrical circuit in telecommunication used to transmit information.[1]
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.
- A number of conductors connected for the purpose of carrying an electric current.
- An electronic closed-loop path among two or more points used for signal transfer.
- A number of active and passive electrical components, and power sources connected in one or more closed loops.
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.[1]
Applications
Originally, telecommunication circuits transmitted analog information. Radio stations used them as studio transmitter links (STLs) or as remote pickup unit (RPU) for sound reproduction, sometimes as a backup to other means. Later lines were digital, used in pair-gain applications, such as carrier systems, or in enterprise data networks.
A leased line, 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 lines are switched circuits.
On certain types of telecommunication circuits, a virtual circuit may be created, while sharing the physical circuit.
Components
Electrical components commonly used in telecommunication circuits include:
- Transistors
- Metal-oxide-semiconductor field-effect transistor (MOSFET)[2]
- Bipolar junction transistor (BJT)
- RF circuit
- Capacitors
- Inductors
- Resistors
See also
- Data transmission circuit
References
- ↑ 1.0 1.1 Freeman, Roger L. (1999). Fundamentals of Telecommunications. John Wiley & Sons, Inc. ISBN 0471296996.
- ↑ Colinge, Jean-Pierre; Greer, James C. (2016). Nanowire Transistors: Physics of Devices and Materials in One Dimension. Cambridge University Press. p. 2. ISBN 9781107052406.