TELECOMMUNICATION CIRCUIT

A 'telecommunication circuit' is defined as follows:
# The complete path between two terminals over which one-way or two-way communications may be provided. See communications protocol.
# An electronic path between two or more points, capable of providing a number of channels.
# A number of conductors connected together 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 electrical components, such as resistors, inductances, capacitors, transistors, and power sources connected together in one or more closed loops.
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In telecommunications, a ['tele']'communication'['s']' circuit' is any line or ''circuit'' on which information is transmitted.
A 'dedicated circuit', 'private circuit', or 'leased line' is a line that is dedicated to only one use. Originally, this was analog, and was often used by radio stations as a studio/transmitter link (STL) or remote pickup unit (RPU) for their audio, sometimes as a backup to other means. Later lines were digital, and used for private corporate data networks.
The opposite of a dedicated circuit is a 'switched circuit', which can be connected to different paths. A POTS or ISDN telephone line is a switched circuit, because it can connect to any other telephone number.
On digital lines, a virtual circuit can be created to serve either purpose, while sharing a single physical circuit.