See network topology.

Technology and Operations (Council)

An antiquated tape relay system in which the perforated tape is manually transferred by an operator to the appropriate outgoing transmitter.

Type of Service

The sum of random noise, intermodulation noise, and crosstalk.
Note: Total channel noise does not include impulse noise because different techniques are required for its measurement.

Of a signal, the ratio of (a) the sum of the powers of all harmonic frequencies above the fundamental frequency to (b) the power of the fundamental frequency.
Note 1: The THD is usually expressed in dB.
Note 2: Measurements for calculating the THD are made at the output of a device under specified conditions.

The reflection that occurs when light, in a higher refractive-index medium, strikes an interface, with a medium with a lower refractive index, at an angle of incidence (with respect to the normal) greater than the critical angle. See Snell's law (Note 3).

In facsimile, the spot speed divided by the scanning line frequency.
Note: The total line length may be greater than the length of the available line.

See touch-sensitive.

See touch-sensitive.