Siemens MC55 manual At+ccwa=1,1,1, +CCWA +491791292364,145,32,,0, At+chld=2

MC55 AT Command Set

9.8 AT+CHLD

s

mobile

1X	Terminate a specific call X (X= 1-7). The call may be active, held or waiting.
	The remote party of the terminated call will receive a "NO CARRIER" indica-
	tion. Parameter X is the call number <idx> of the targeted call in the list of cur-
	rent calls available with AT command AT+CLCC.
2	Place all active calls on hold (if any) and accept "the other call" as the active
	call:
	• If a call is waiting, the waiting call will be accepted.
	• Otherwise, if a held call is present, the held call becomes active.
2X	Place all active calls except call X (X= 1-7) on hold. Parameter X is the call
	number <idx> of the targeted call in the list of current calls available with AT
	command AT+CLCC.
3	Add a held call to the active calls in order to set up a conference (multiparty)
	call.

Notes

•The AT+CHLD command offers a broad range of options according to the GSM specifications. However, if you attempt to invoke an option which is not provisioned by the network, or not subscribed to, invocation of this option will fail. The responses in these cases may vary with the network (for example "Operation not allowed", "Operation not supported" etc.).

•This Supplementary Service is only applicable to Teleservice 11 (Speech telephony), that is, voice calls can be put on hold, while data or fax calls cannot. For example, with AT+CHLD=2 you can simultaneously place a voice call on hold and accept another waiting voice call. But it is possible to place a voice call on hold in order to accept a waiting data of fax call, and afterwards recover the voice call. In this case, the only difference over speech telephony is that the data or fax call needs to be manually accepted via ATA (see example below).

•In conflict situations, e.g. when a waiting call comes while there are already held calls, the above procedures apply to the waiting call only. For example, <n>=0 rejects the waiting call, but does not affect the held calls.

•See also the AT+CCWA command for details on how to display waiting calls.

Example

^SYSSTART

at+cpin="9999"

OK

+CREG: 2

+CREG: 1,"0145","0016"	The mobile is now registered.
at+ccwa=1,1,1	You activate the indication of waiting calls during
	voice calls.
OK
atd"1234567";	You make a voice call.
OK
+CCWA: "+491791292364",145,32,,0	You receive a URC indicating a waiting data call.
at+chld=2	You put the voice call on hold.
RING	You now receive the RING of the data call.

MC55_ATC_V01.05	Page 231 of 469	2/10/04
Confidential / Released