User guide

3GPP TS 27.007 AT COMMANDS
61 AT Commands for EV-DO-EV3 Modems
Call Holding Services +CHLD
Execute command controls the network call hold service. This command is used to manage call hold and
multiparty conversation (conference call). Calls can be put on hold, recovered, released or added to a
conversation.
Test command returns the list of supported <n>s.
+CHLD: (2)
Syntax
Command Command type
AT+CHLD=[<n>] Execute
AT+CHLD=? Test
Parameters and Values
<n>
2 Places all active calls, if any exist, on hold and accepts the other (held or waiting)
call. If no calls are active, only OK is sent.
Notes
 Only for VOICE calls.
 Reference: 3GPP TS 27.007.
List Current Calls +CLCC
Execute command returns the list of current calls and their characteristics in the format:
[+CLCC:<id1>,<dir>,<stat>,<mode>,<mpty>,<number>,<type>,<alpha>[<CR><LF>+CLCC:<
id2>,<dir>,<stat>,<mode>,<mpty>,<number>,<type>,<alpha>[…]]]
where:
<idn> Call identification number.
<dir> Call direction.
0 Mobile originated call.
1 Mobile terminated call.
<stat> State of the call.
0 Active.
1 Held.
2 Dialing (MO call).
3 Alerting (MO call).
4 Incoming (MT call).
5 Waiting (MT call).
<mode> Call type.
0 Voice.
1 Data.
9 Unknown.
<mpty> Multiparty call flag.
0 Call is not one of multiparty (conference) call parties.
1 Call is one of multiparty (conference) call parties.