A3LA-R User Guide Version A
Document Number: 451-93156-001A
118 of 158
“0”
Releases all held calls or sets User Determined User Busy (UDUB) for a
waiting call
“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 shall
be supported
“3”
Adds a held call to the conversation
“4”
Not supported (Connects the two calls and disconnects the subscriber
from both calls (ECT))
“4*dirno”
Not supported (Redirect an incoming or a waiting call to the
specified directory number)
“5”
Not supported ($(CCBS)$: Activates the Completion of Calls to Busy
Subscriber Request)
Test Command:
+CHLD=?
Test command returns the <n> values supported by the phone. The response is in the
form:
+CHLD:(list of supported <n>s)
Note:
“AT+CHLD=0” can be used to set UDUB when there is an incoming call, whether
or not there is a current call active (or held), in order to support GSM 02.30 [5]
subclauses 4.4.2.3 and 4.5.5.2.
B.121 +XCSI
–
E
XTENDED
C
ALL
S
TATE
I
NFORMATION
This proprietary unsolicited announcement was added to allow the DTE to keep track
of call state during Call Hold and Multiparty operations using AT+CHLD.
Exec Command:
none
Unsolicited Announcement: