A3LA-R-MIL-MOD User Guide Version B
Document Number: 451-93156-001A
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This command is not abortable, and finishes without waiting for a response from the
network. The interaction of this command with other commands based on other GSM
supplementary services is described in the GSM standard.
The following parameter values are currently supported:
<n>:
“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] sub
clauses 4.4.2.3 and 4.5.5.2.