Glossary - Sony PMS-500P Bedienungsanleitung

Glossary

B-channel
The B-channel directly communicates "information"
(voice, data, facsimile). One ISDN line provides 2
communication lines.
BRI
An abbreviation for Basic Rate Interface. Single ISDN
has two B-channels and one D-channel.
Bus connection
A wiring method in which many jacks can be
implemented on one line, allowing up to 8 devices to
communicate simultaneously. (Those devices are
connected to the jacks.)
Calling line identification presentation service
A service that sends a caller's number to the called
party. The called party can determine who is calling
and accept or reject the call.
CIF
An abbreviation for Common Intermediate Format.
This format allows communication between different
color systems (NTSC or PAL). (352 pixels × 288
lines)
Circuit switching
Sets a line for each communication and occupies that
line during communication. The communication
charge is determined by the occupation time.
Codec
An abbreviation for Coder-Decoder. An electronic
device that converts an analog signal such as voice or
video to a digital data stream, compresses it, and sends
it over a digital communications line. Another codec
reverses the process at the receiving site.
Compression
A task where a codec compresses data before sending
it over a digital communications line.
D-channel
The D-channel sends/receives communication control
signals. If the packet communication mode is used, the
D-channel is available for packet communication on
the D-channel.
DSU
An abbreviation for Digital Service Unit. A terminal
device that connects to an ISDN network. Digital
telephones, digital faxes, and terminal adapters (TA)
are connected to DSUs, which are in turn connected to
telephone lines. To connect a digital device to an
ISDN network, you need the DSU in addition to the
digital device.
Echo canceller
Equipment to remove annoying echo or howling noise
to improve call quality.
Frame rate
The number of frames which can be decoded in one
second.
G.711
Pulse code modulation (PCM) of voice frequencies.
G.722
7 kHz audio-coding within 64 Kbps.
G.728
Coding of speech at 16 Kbps using low-delay code
excited linear prediction.
H.221
Frame structure for a 64 to 1920 Kbps channel in
audiovisual teleservices.
H.261
Video codec for audiovisual services as p × 64 Kbps.
H.263
This is basically based on H.261, however, this enables
communication using a lower bit rate.
H.320
Narrow-band visual telephone systems and terminal
equipment.
Interface
A protocol connecting two different devices so that
they can communicate with each other.
ISDN
An acronym for Integrated Services Digital Network.
This is a communications protocol defined by CCITT
for transmission of integrated voice, video, and data.
Bandwidths include basic (64 Kbps) and primary rate
(1.544 and 2.048 Mbps).
A-11
Appendix (GB)