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DVST

Digital Video Storage and Transmission

ISDN

Integrated Services Digital Network - A digital telephone system capable of
transmitting data, speech, images and text.

PSTN

Public Subscriber Trunk Network - The standard telephone system used for
speech and fax communication.

Speed of Update

The time taken to refresh a single picture.

Software
Compression

Video data compression achieved by computer program processing.

Hardware
Compression

Video data compression taking place in specialised purpose built microchips.

k bytes

Measurement expressing the size of digital computer memory

k bits per
second

Measurement expressing the speed at which data can be transmitted.

Compression

Taking standard video signals and reducing these into compact digital data.

Decompression

Taking digitally compressed DVST information and restoring this to normal
video images.

Complete
compression

Each time the picture is transmitted, or stored to memory, the entire picture is
compressed.

Conditional
Updating

Update only the parts of the picture that have changed. The first time the
picture is transmitted the entire picture is compressed. Thereafter only the
parts of the picture that change are transmitted.

DAT

Digital Audio Tape, the new technology for recording digital information on a
special tape cassette. Massive storage can be achieved in a very small
package.

MODEM

MOdulator/DEModulator used to connect the DVST unit to a standard
telephone line.

Terminal
Adapter

Used to connect the DVST to an ISDN digital telephone line.

Dedicated Micros Ltd.

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DVST Installation Guide

Glossary