Decoding – Wavecom W74PC V8.7.0 User Manual
Page 316
306
Modem and FAX Modes
WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V8.7.0
ITU-T
Rec.
User Data Rate [bps]
User
Input
Transmission
Format
Full
or
Half-
duplex
2 or 4
Wire
Modulation
V.27bis
4800/2400
Sync
FDX
4W
D8PSK
V.27ter
4800/2400
Fax
HDX
2W
D8PSK
V.29
9600
Fax
FDX
4W
16QAM
V.32
9600/7600/4800
Sync/Async
FDX
2W
Trellis coded
32/16/4QAM
V.32bis
14400/12000/9600/
7200
Sync/Async
FDX
2W
Trellis coded
128/64/32/
16QAM
V.34
Up to 33600
Fax/Sync/Async
FDX
2W
Trellis coded QAM
V.90
Down: 56000
Up: 33600
Async
FDX
2W
Down: PCM, digital
Up: V.32 analogue
V.92
Down: 56000
Up: 33600
Async
FDX
2W
Down: PCM, digital
Up: V.32, ana-
logue.
“Internet call wait-
ing”
Decoding
The fax and modem decoding features depends on three software modules which analyze one or two in-
coming bit streams (calling and answering modems) in G.711 format (8 kHz sampling rate, A- or mu-law)
or a 16 bit linear format.
The first module analyzes the initial handshakes to route the bit stream(s) to the appropriate demodula-
tion modules – fax or full-duplex data - of the next stage.
The next module demodulates the signal, and echo cancellation is applied if in use.
The last module processes fax ECM (Error Correction Mode) as well as performing data link layer analysis
on data signals. The various fax and data modes are then decoded and output in a number of formats.