Of a medium, the ratio of the velocity of propagation of an electromagnetic wave in vacuum to its velocity in the medium. Synonym index of refraction.
Note: When the Greek character eta is unavailable, the letter n is used to represent the refractive index.

In an optical fiber, a measure of the relative difference in refractive index of the core and cladding.
Note: Refractive index contrast, , is given by = (n12- n 22)/(2n12), where n1 is the maximum refractive index in the core and n2 is the refractive index of the homogeneous cladding.

Of the cross section of an optical fiber, the description, i.e., plot, of the value of the refractive index as a function of distance from the fiber axis along a diameter. Synonyms index profile, refraction profile.

The time interval between the instant at which a valid frame-alignment signal is available at the receiving data terminal equipment and the instant at which frame alignment is established.
Note: The reframing time includes the time required for replicated verification of the validity of the frame-alignment signal. Synonym frame-alignment recovery time.

To reproduce, repeatedly, a display image on a display surface, so that the image remains visible.

Signaling packets that are transmitted on a periodic basis across a permanent virtual circuit in the direction of transmission from the channelized side to the packetized side. This allows the originating endpoint to update the knowledge of the terminating endpoint regarding the signaling information on the incoming channel and the status of the permanent virtual circuit status. [T1.312-1991]

1. In a regenerative repeater, the process by which digital signals are amplified, reshaped, retimed, and retransmitted. Synonym positive feedback.
2. In a storage or display device, the restoration of stored or displayed data that have deteriorated.
Note: For example, conventional cathode-ray tube displays must be continually regenerated for the data to remain displayed.
3. In computer graphics, the sequence… (Read More →)

Feedback in which the portion of the output signal that is returned to the input has a component that is in phase with the input signal.

A repeater, designed for digital transmission, in which digital signals are amplified, reshaped, retimed, and retransmitted. Synonym regenerator.

1. Synonym regenerative repeater.
2. A device that reconstructs and retransmits a received pulse train. [T1.403-1989]