Guardian Technologies , LLC Home Security System DVST User Manual download pdf (Page 73)

15 Glossary

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. Page 61

DVST Installation Guide Glossary

1 2 ... 68 69 70 71 72 73 74 75 76 77 78 79 80

No comments

Guardian Technologies , LLC Home Security System DVST User Manual Page 73