Cellular text telephone modem +wctm – Rainbow Electronics FARGO MAESTRO 100 (with TCP_IP) User Manual
Page 117

Global Configuration Commands
Cellular Text Telephone Modem +WCTM
©Restricted
Page:
111 / 184
This document is the sole and exclusive property of Wavecom. Not to be distributed or divulged without
prior written agreement.
WM_DEV_OAT_UGD_049 - 001
VOLUME 1
August 23, 2007
6.22
Cellular Text Telephone Modem +WCTM
6.22.1
Description
This Wavecom proprietary command allows the user to activate and deactivate the
Cellular Text telephone Modem capability for outgoing voice call as specified in 3GPP
24.008
181H
[8].
CTM mode is used to send audio signals from an external text terminal (ex: a TTY
typewriter) within a voice call made by the ME. The text terminal must have a special
mobile phone input/output to work correctly.
When the ME indicates that CTM text telephony for an outgoing voice call is
supported, the network selects a speech CODEC and additionally CTM text telephony
detection and conversion functions.
To guarantee optimal audio management of CTM signals, it is mandatory to
deactivate Acoustic Echo Cancellation (see +ECHO command) and Side Tone (see
+SIDET command).
Voice gain of transmitter and receiver (see +VGR, +VGT commands) have to be
calibrated according to the external text terminal audio characteristics.
6.22.2
Syntax
Action command
AT+WCTM=
OK
Read command
AT+WCTM?
+WCTM:
OK
Test command
AT+WCTM=?
+WCTM: (list of supported
OK