In video, the insertion of a nonlinear output-input characteristic for the purpose of changing the system transfer characteristic. [IEEE 100]
Note: Historically, gamma correction was a precompensation applied to the video signal at the camera to correct for the nonlinearities of the CRT (i.e., the power function of the electron gun) and, as such, it was the inverse of the… (Read More →)

A period of low energy content signals present of a digital speech interpolation device. [T1.509-1995]

1. The power loss that occurs when an optical signal is transferred from one fiber to another that is axially aligned with it, but longitudinally separated from it.
Note: The gap allows light from the "transmitting" fiber to spread out as it leaves the fiber endface. When it strikes the "receiving" fiber, some of the light will enter the cladding,… (Read More →)

An optical attenuator that exploits the principle of gap loss to reduce the optical power level when inserted in-line in the fiber path; e.g., to prevent saturation of the receiver.
Note: Gap-loss attenuators should be used in-line near the optical transmitter. [After FAA]

Periods of no speech activity or low-energy content signals present in the access channel of a wideband packet network. [T1.312-1991]

1. An error in transmission, reception, encryption, or decryption that changes the text of a message or any portion thereof in such a manner that it is incorrect or undecryptable. [JP 1-02]
2. In a telephone circuit or channel, readily audible but unintelligible interference from another circuit or channel.
Note: Garble may, for example, take place in an FDM telephone… (Read More →)

1. A device having one output channel and one or more input channels, such that the output channel state is completely determined by the input channel states, except during switching transients.
2. One of many types of combinational logic elements having at least two inputs; e.g., AND, OR, NAND, and NOR.

1. In a communications network, a network node equipped for interfacing with another network that uses different protocols.
Note 1: A gateway may contain devices such as protocol translators, impedance matching devices, rate converters, fault isolators, or signal translators as necessary to provide system interoperability. It also requires that mutually acceptable administrative procedures be established between the two networks.
Note… (Read More →)

1. The process of selecting only those portions of a wave between specified time intervals or between specified amplitude limits.
2. The controlling of signals by means of combinational logic elements.
3. A process in which a predetermined set of conditions, when established, permits a second process to occur.

A beam of light whose electric field intensity distribution is gaussian.
Note: When such a beam is circular in cross section the intensity at distance r from the center,E(r), is given by where E(0) is the electrical field strength at the beam center, i.e., at r = 0; and w is the value of r at which the intensity is… (Read More →)