Westermo ID-90 - Manual (Page 112)

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Glossary
-law
Coding standard in use in USA for Pulse Code Modulated (PCM) voice-band signals.
A-law
Coding standard in use in Europe for Pulse Code Modulated (PCM) voice-band signals
(CCITT G.711).
ASCII
A binary code system which defines 128 characters using different combinations of 1s and
0s. ASCII = American Standard Code for Information Interchange.
Asynchronous Data
Transmission where the characters are transmitted one at a time, starting with a start bit
and ending with a stop bit. About 90–95% of all serial data communications are asynchro-
nous.
Baud
The number of data symbols transmitted every second. In local data communications,
baud = bit/s. In telecommunication, each symbol may encode several bits.
BC
Bearer Capability, one of the services obtained through a request sent on the D-channel.
Bearer services provide data transfer at layers 1, 2, and 3 of the OSI reference model, but
do not verify the compatibility at a higher layer of the connected devices.
B-channel
64 kbit/s, can be splitted in (8, 16 and 32 kbits/s), the sub-channels must although be
addressed to the same final destination. Example of information carried in the B-channel is:
Voice encoded at 64 kbit/s according to Recommendation G.711;
Data information corresponding to circuit or packet-switching user classes of service at
bit rates less than or equal to 64 kbit/s, according to Recommendation X.1;
Videband voice encoded at 64 kbit/s according to Recommendation G.722;
voice encoded at bit rates lower than 64 kbit/s alone, or combined with other
digital information streams.
B-ISDN
Broadband-ISDN.
BOD
Bandwidth On Demand.
BRI/BRA
Basic Rate Interface / Basic Rate Access; the interface configuration with two 64 kbit/s
information channels 2B and one 16 kbit/s signalling channel D, 2B + 1D, B=Bearer
D=Delta.