LevelOne VOI-7100 User Manual
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G.729 The G.729 and G.729A conjugate structure algebraic code excited linear
prediction (CS-ACELP) coding scheme also compresses PCM using advanced
codebook technology. It uses 8000 bps of total bandwidth.
G.723 The G.723 and G.723A multipulse maximum likelihood quantization
(MPMLQ) coding schemes use a look-ahead algorithm. These compression
schemes result in a required bandwidth of 6300 or 5300 bps.
GSM GSM (Global System for Mobile communications) is a cellular phone
system standard popular outside the USA. The speech signal is divided into
blocks of 20 ms. These blocks are then passed to the speech codec, which has
a rate of 13 kbps, in order to obtain blocks of 260 bits.
Note
The network administrator should balance the need for
voice quality against the cost of bandwidth in the
network when choosing CODECs.