Decoding – Wavecom W74PC V8.7.0 User Manual

Page 316

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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.

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