A digital video compression technique based on Shannon’s distortion-rate theory which states that the performance of data compression systems improves if blocks of data are coded, with larger coded data blocks giving better performance.
Lasers that emit light perpendicular to the plane of the wafer they are grown on. They have very small dimensions compared to conventional lasers and are very efficient.
A modified double-sideband transmission in which one sideband, the carrier, and only a portion of the other sideband are transmitted. See also sideband.
Abbreviation for video graphics array. A high-resolution color standard for computer monitors.
Abbreviation for very high frequency. The frequencies, ranging from 30 MHz to 300 MHz, in the electromagnetic spectrum. Contains off-air television channels 2-12.
A term used for interactive or customized video delivery service.
Conducting conferences via a video telecommunications system.
A telephone-like service with a picture as well as sound.
A communications arrangement in which data from a source user may be passed to a destination user over various real circuit configurations during a single period of communication, usually on a per call basis, although permanent connections can be established.
A circuit capable of carrying one telephone conversation or its equivalent; the standard sub-unit in which telecommunication capacity is counted. The U.S. analog equivalent is 4 kHz. The digital equivalent is 64 kbit/s in North America and in Europe.
(VAC) Abbreviation for Volts, AC. Voltage using alternating current.
(VDC) Abbreviation for Volts, DC. Voltage using direct current.
Abbreviation for virtual private network. A protected information-system link utilizing tunneling, security controls, and end-point address translation giving the end user the impression that a dedicated line exists between nodes.