Syntax, Parameters and values, Notes – Synaccess Networks NP-0801DTM User Manual
Page 66: Unstructured supplementary service data +cusd

3GPP TS 27.007 AT COMMANDS
HSPA+ AT Commands Reference Guide
66
Syntax
Command
Command type
AT+CHLD=[
Execute
AT+CHLD=?
Test
Parameters and Values
0
Releases all held calls, or sets the UDUB (User Determined User Busy) indication
for a waiting call. (only from version D).
1
Releases all active calls if any exist, and accepts the other (held or waiting) call
1X
Releases a specific active call X.
2
Places all active calls, if any exist, on hold and accepts the other (held or waiting)
call.
2X
Places all active calls on hold except call X with which communication is
supported (only from version D).
3
Adds held call to the conversation.
4
Connects the two calls and disconnects the subscriber from both calls (Explicit Call
Transfer (ECT))
Note: "X" is the numbering (starting with 1) of the call given by the sequence of
setting up or receiving the calls (active, held or waiting) as seen by the served
subscriber. Calls hold their number until they are released. New calls take the
lowest available number.
Note: Where both a held and a waiting call exist, the above procedures apply to
the waiting call—not to the held call—in conflicting situations.
Notes
Only for VOICE calls.
Reference: 3GPP TS 27.007.
Unstructured Supplementary Service Data +CUSD
Set command allows control of the Unstructured Supplementary Service Data (USSD [GSM 02.90]).
Read command reports the current value of the parameter
Test command reports the supported values for the parameter
Syntax
Command
Command type
AT+CUSD=[
Set
AT+CUSD?
Read
AT+CUSD=?
Test
Parameters and Values
Disables or enable the presentation of an unsolicited result code.
0
Disable the result code presentation in the DTA.
1
Enable the result code presentation in the DTA.
2
Cancel an ongoing USSD session. Not applicable to read command response.