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laforge, 11/20/2022 07:49 PM
ITU-T Recommendation V.110¶
V.110 is an ITU standard for bit-rate adaptation of low-speed async serial signals (600, 1200, 2400, 4800, 7200, 9600, 12000, 14400, 19200, 24000, 28800 or 38400 bit/s) to 64 kbit/s ISDN B-channels. It was primarily used in the context of interworking between GSM Circuit Switched Data (CSD) and ISDN.
Details¶
Frame structure¶
The protocol uses an 80bit (10 byte) frame. The Frame contains a frame sync pattern (similar to e.g. E1 TS0 or TRAU frames) consisting of the first byte and the first bit of every following byte.
Each frame consists of
- 17 bits of above-mentioned frame sync pattern plus:
- 48 D-bits (D1..D48)
- 7 E-bits (E1..E7)
- 8 S/X-bits (S1,S3,S4,S6,S8,S9)
Rate Adaptation Functions¶
RA1¶
The rate-adaptation function RA1 converts from the V-series rates (e.g. 2400bps) to an intermediate rate of 8/16/32/64 kbit/s.
RA2¶
RA2 converts from the RA1 output rate of 8/16/32/64 kbit/s to 64 kbit/s
Updated by laforge over 1 year ago · 2 revisions