> 2.7.3 | Multiparty

> Figure 33: Multiparty

> 2.7.3.1 | Multiparty initialization

> This section comprises the subsections Description, Used AT Commands, Flow Chart, Hints and Example. To move to these subsections please use the Navigation Frame or the appropriate buttons on the toolbar.

> 2.7.3.1.1 | Description

> This chapter describes all the steps required to initialize the supplementary service Multiparty call waiting, call hold.
> This can be done in two steps:

> • | First, activate the presentation of the URC that indicates a waiting caller to the called party. This URC takes the form “+CCWA: <number>,<type>,<class>,,<CLI validity>” or “^SCWA”. For further detail please refer to [2]. Please note that “^SCWA” is not considered in the following examples. The activation of the URC only has effect on the module and does not involve any network related activities. Therefore the response from the module will be returned immediately. The setting will not be stored when powering off the module.

> • | Activate Call waiting (Flow chart and example only show the scenario for voice). This action has effect on the network because the settings will be stored in the network. Therefore the module response will take a longer time and the setting will still be present after power off and restart of the module.

> It is recommended to save this initialization and only deactivate it when you are sure that the indication of waiting calls is not needed any longer.

> 2.7.3.1.2 | Used AT commands

> Command | Explanation
> AT+CCWA | Call waiting
> ATD*#43#; | Querying status of call waiting
> ATD*43*BS#; | Activate call waiting
> ATD#43# | Deactivate call waiting

> For further details about the commands see [2].

> 2.7.3.1.3 | Flow chart

> Figure 34: Multiparty initialization

> 2.7.3.1.4 | Hints

> • | The URC presentation mode will not be retained when the module is powered down. After restart, the default setting AT+CCWA=0 will be restored. The activation of Call waiting itself will be stored on network side and therefore, is not affected when you shut down the module.

> GCF-CC note: *# sequences the user enters on the keypad shall be transmitted over the AT interface without any conversion. Also, GCF test cases require that *# sequences can be entered during a call.

> 2.7.3.1.5 | Example

> Example 1:
> ***************************************
> Comment: Initalization multiparty
> ***************************************
> ***************************************
> Comment: Status query for display of URC.
> Note that URC presentation will be disabled after reboot of the module.
> ***************************************
> Subscr 2 Send: AT+CCWA?
> Subscr 2 Receive: AT+CCWA?
> Subscr 2 Receive: +CCWA: 0
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> ***************************************
> Comment: Display of URC disabled, next step: enable display for URC.
> ***************************************
> Subscr 2 Send: AT+CCWA=1
> Subscr 2 Receive: AT+CCWA=1
> Subscr 2 Receive: OK
> ***************************************
> Comment: Status query for CCWA, Subscriber2.
> ***************************************
> Subscr 2 Send: AT+CCWA=,2,1
> Subscr 2 Receive: AT+CCWA=,2,1
> Subscr 2 Receive:
> Subscr 2 Receive: +CCWA: 0,1
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> ***************************************
> Comment: CCWA during voice calls disabled, next step: enable CCWA for voice only.
> ***************************************
> Subscr 2 Send: AT+CCWA=,1,1
> Subscr 2 Receive: AT+CCWA=,1,1
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> ***************************************
> Comment: Status query for enabled value.
> ***************************************
> Subscr 2 Send: AT+CCWA=1,2,1
> Subscr 2 Receive: AT+CCWA=1,2,1
> Subscr 2 Receive:
> Subscr 2 Receive: +CCWA: 1,1
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> Example 2:
> ***************************************
> Comment: Initalization multiparty
> ***************************************
> ***************************************
> Comment: Alternative option using *# sequence.
> Comment: Status query for display of URC. Note that URC presentation will be
> disabled after reboot of the module.
> ***************************************
> Subscr 2 Send: AT+CCWA?
> Subscr 2 Receive: AT+CCWA?
> Subscr 2 Receive: +CCWA: 0
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> ***************************************
> Comment: Display of URC disabled, next step: enable display of URC.
> ***************************************
> Subscr 2 Send: AT+CCWA=1
> Subscr 2 Receive: AT+CCWA=1
> Subscr 2 Receive: OK
> ***************************************
> Comment: Status query for CCWA, Subscriber2.
> ***************************************
> Subscr 2 Send: ATD*#43#;
> Subscr 2 Receive: ATD*#43#;
> Subscr 2 Receive:
> Subscr 2 Receive: +CCWA: 0,1
> Subscr 2 Receive: +CCWA: 0,8
> Subscr 2 Receive: +CCWA: 0,4
> Subscr 2 Receive: +CCWA: 0,2
> Subscr 2 Receive: OK
> ***************************************
> Comment: CCWA during voice calls disabled, next step: enable CCWA for voice only.
> ***************************************
> Subscr 2 Send: ATD*43*11#;
> Subscr 2 Receive: ATD*43*11#;
> Subscr 2 Receive:
> Subscr 2 Receive: +CCWA: 1,1
> Subscr 2 Receive: OK
> ***************************************
> Comment: Status query for enabled value.
> ***************************************
> Subscr 2 Send: ATD*#43#;
> Subscr 2 Receive: ATD*#43#;
> Subscr 2 Receive: +CCWA: 1,1
> Subscr 2 Receive: +CCWA: 0,8
> Subscr 2 Receive: +CCWA: 0,4
> Subscr 2 Receive: +CCWA: 0,2
> Subscr 2 Receive: OK

> 2.7.3.2 | Multiparty – call waiting during voice calls

> This section comprises the subsections Description, Used AT Commands, Flow Chart, Hints and Example. To move to these subsections please use the Navigation Frame or the appropriate buttons on the toolbar.

> 2.7.3.2.1 | Description

> This chapter describes all the steps needed to use the Multiparty supplementary services call waiting and call hold for voice calls.
> At least three subscribers are involved. Two subscribers are connected and a third subscriber is calling subscriber 2. This waiting call is accepted while subscriber 1 is on hold. Then, the active call is terminated and the held call will be activated automatically. Generally, a call “on hold” doesn’t have a voice connection to the connected party.

> 2.7.3.2.2 | Used AT commands

> Command | Explanation
> ATA | Answer a call
> ATD | Mobile originated call to dial a number
> ATH | Disconnect existing connection
> AT+CHLD | Call hold and multiparty
> AT+CLCC | Returns a list of current calls

> For further details about the commands see [2].

> 2.7.3.2.3 | Flowchart

> Figure 35: Multiparty - call waiting during voice calls - part 1
> Figure 36: Multiparty - call waiting during voice calls- part 2

> 2.7.3.2.4 | Hints

> • | Only a voice call can be put on hold in order to accept a waiting voice, data or fax call. In case of a data call you can only terminate this data call and accept the waiting call.

> • | A data or fax call cannot be put on hold.

> GCF-CC note: *# sequences the user enters on the keypad shall be transmitted over the AT interface without any conversion. Also, GCF test cases require that *# sequences can be entered during a call.

> 2.7.3.2.5 | Example

> ***************************************
> Comment: Multiparty Call waiting during voice calls
> ***************************************
> ***************************************
> Comment: Establish voice call Sub1-->Sub2
> ***************************************
> Subscr 1 Send: atd<Sub2>;
> ***************************************
> Comment: Sub2: waiting for CRING
> ***************************************
> Subscr 1 Receive: atd<Sub2>;
> Subscr 2 Receive:
> Subscr 2 Receive: +CRING: VOICE
> ***************************************
> Comment: Sub2: accept waiting call of Sub1
> ***************************************
> Subscr 2 Send: ATA
> Subscr 2 Receive: ATA
> Subscr 2 Receive: OK
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> ***************************************
> Comment: Request list of current calls
> ***************************************
> Subscr 1 Send: at+clcc
> Subscr 1 Receive: at+clcc
> Subscr 1 Receive: +CLCC: 1,0,0,0,0,"<Sub2>",129
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> ***************************************
> Comment: 2nd call Sub3-->Sub2
> ***************************************
> Subscr 3 Send: atd<Sub2>;
> Subscr 3 Receive: atd<Sub2>;
> Subscr 2 Receive:
> Subscr 2 Receive: +CCWA: "<Sub3>",145,1,,0
> ***************************************
> Comment: 2nd call accepted by Sub2, Sub1 on hold, Sub2 connected with Sub3
> ***************************************
> Subscr 2 Send: at+chld=2
> Subscr 2 Receive: at+chld=2
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> Subscr 3 Receive:
> Subscr 3 Receive: OK
> ***************************************
> Comment: Request list of current calls
> ***************************************
> Subscr 1 Send: at+clcc
> Subscr 1 Receive: at+clcc
> Subscr 1 Receive: +CLCC: 1,0,0,0,0,"<Sub2>",129
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> Subscr 2 Send: at+clcc
> Subscr 2 Receive: at+clcc
> Subscr 2 Receive: +CLCC: 1,1,1,0,0,"<Sub1>",145
> Subscr 2 Receive: +CLCC: 2,1,0,0,0,"<Sub3>",145
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> Subscr 3 Send: at+clcc
> Subscr 3 Receive: at+clcc
> Subscr 3 Receive: +CLCC: 1,0,0,0,0,"<Sub2>",129
> Subscr 3 Receive:
> Subscr 3 Receive: OK
> ***************************************
> Comment: Sub2 disconnects active connection to Sub3, connection to Sub1 re-activated
> ***************************************
> Subscr 2 Send: at+chld=1
> Subscr 3 Receive:
> Subscr 3 Receive: NO CARRIER
> Subscr 2 Receive: at+chld=1
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> ***************************************
> Comment: Request list of current calls
> ***************************************
> Subscr 1 Send: at+clcc
> Subscr 1 Receive: at+clcc
> Subscr 1 Receive: +CLCC: 1,0,0,0,0,"<Sub2>",129
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> Subscr 2 Send: at+clcc
> Subscr 2 Receive: at+clcc
> Subscr 2 Receive: +CLCC: 1,1,0,0,0,"<Sub1>",145
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> Subscr 3 Send: at+clcc
> Subscr 3 Receive: at+clcc
> Subscr 3 Receive: OK
> ***************************************
> Comment: Sub2 disconnects the last active connection to Sub1
> ***************************************
> Subscr 2 Send: ATH
> Subscr 2 Receive: ATH
> Subscr 2 Receive: OK
> Subscr 1 Receive:
> Subscr 1 Receive: NO CARRIER
> ***************************************
> Comment: Request list of current calls
> ***************************************
> Subscr 1 Send: at+clcc
> Subscr 1 Receive: at+clcc
> Subscr 1 Receive: OK
> Subscr 2 Send: at+clcc
> Subscr 2 Receive: at+clcc
> Subscr 2 Receive: OK
> Subscr 3 Send: at+clcc
> Subscr 3 Receive: at+clcc
> Subscr 3 Receive: OK

> 2.7.3.3 | Multiparty – conference call

> This section comprises the subsections Description, Used AT Commands, Flow Chart, Hints and Example. To move to these subsections please use the Navigation Frame or the appropriate buttons on the toolbar.

> 2.7.3.3.1 | Description

> This chapter describes all the steps needed to use the Multiparty supplementary services call waiting and call hold for a conference call.
> At least three subscribers are involved. At first two subscribers (1 and 2) are connected.
> There are two ways to establish a conference call:

> • | Subscriber 2 puts subscriber 1 on hold while he is establishing an additional call. Afterwards the held call will be connected to the active call in order to establish a conference call.

> • | If during an active call an additional call comes in, the active call has to be put on hold, the waiting call is accepted and afterwards the held call has to be added to the active call.

> 2.7.3.3.2 | Used AT commands

> Command | Explanation
> ATA | Answer a call
> ATD | Mobile originated call to dial a number
> AT+CHLD | Call hold and multiparty
> AT+CLCC | Returns a list of current calls

> For further details about the commands see [2].

> 2.7.3.3.3 | Flow chart

> Figure 37: Multiparty - conference call - part 1
> Figure 38: Multiparty - conference call - part 2
> Figure 39: Multiparty - conference call - part 3
> Figure 40: conference call - part 4

> 2.7.3.3.4 | Hints

> • | When a subscriber disconnects from a 3-party conference call, the related entry is cleared from the list of current calls provided with AT+CLCC. Yet, the multiparty parameter <mpty> of the other two subscribers will not be updated in the list. This means, although the status of the call has changed to a simple 2-party call, the value of <mpty> remains 1 (multiparty) instead of being reset to 0 (no multiparty).

> • | If you try to add a party to a conference call, and the call is answered by the mailbox, you are advised to disconnect the call with AT+CHLD=1X. Otherwise, in extreme cases, the conference call might be recorded until the mailbox automatically disconnects the call.

> GCF-CC note: *# sequences the user enters on the keypad shall be transmitted over the AT interface without any conversion. Also, GCF test cases require that *# sequences can be entered during a call.

> 2.7.3.3.5 | Example

> ***************************************
> Comment: Multiparty conference call
> ***************************************
> ***************************************
> Comment: Establish voice call Sub1-->Sub2
> ***************************************
> Subscr 1 Send: ATD<Sub2>;
> ***************************************
> Comment: Sub2: waiting for CRING
> ***************************************
> Subscr 1 Receive: ATD<Sub2>;
> Subscr 2 Receive:
> Subscr 2 Receive: +CRING: VOICE
> ***************************************
> Comment: Sub2: accept waiting call of Sub1
> ***************************************
> Subscr 2 Send: ATA
> Subscr 2 Receive: ATA
> Subscr 2 Receive: OK
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> ***************************************
> Comment: Put active call on hold
> ***************************************
> Subscr 2 Send: AT+CHLD=2
> Subscr 2 Receive: AT+CHLD=2
> Subscr 2 Receive: OK
> ***************************************
> Comment: Establish voice call Sub2-->Sub3
> ***************************************
> Subscr 2 Send: ATD<Sub3>;
> ***************************************
> Comment: Sub3: waiting for CRING
> ***************************************
> Subscr 2 Receive: ATD<Sub3>;
> Subscr 2 Receive: OK
> Subscr 3 Receive:
> Subscr 3 Receive: +CRING: VOICE
> ***************************************
> Comment: Sub3: accept waiting call of Sub2
> ***************************************
> Subscr 3 Send: ATA
> Subscr 3 Receive: ATA
> Subscr 3 Receive: OK
> ***************************************
> Comment: Request list of current calls
> ***************************************
> Subscr 1 Send: AT+CLCC
> Subscr 1 Receive: AT+CLCC
> Subscr 1 Receive: +CLCC: 1,0,0,0,0,"<Sub2>",129
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> Subscr 2 Send: AT+CLCC
> Subscr 2 Receive: AT+CLCC
> Subscr 2 Receive: +CLCC: 1,1,1,0,0,"<Sub1>",145
> Subscr 2 Receive: +CLCC: 2,0,0,0,0,"<Sub3>",129
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> Subscr 3 Send: AT+CLCC
> Subscr 3 Receive: AT+CLCC
> Subscr 3 Receive: +CLCC: 1,1,0,0,0,"<Sub2>",145
> Subscr 3 Receive:
> Subscr 3 Receive: OK
> ***************************************
> Comment: Add the held call to the active call
> ***************************************
> Subscr 2 Send: AT+CHLD =3
> Subscr 2 Receive: AT+CHLD=3
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> ***************************************
> Comment: Request list of current calls
> ***************************************
> Subscr 1 Send: AT+CLCC
> Subscr 1 Receive: AT+CLCC
> Subscr 1 Receive: +CLCC: 1,0,0,0,0,"<Sub2>",129
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> Subscr 2 Send: AT+CLCC
> Subscr 2 Receive: AT+CLCC
> Subscr 2 Receive: +CLCC: 1,1,0,0,1,"<Sub1>",145
> Subscr 2 Receive: +CLCC: 2,0,0,0,1,"<Sub3>",129
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> Subscr 3 Send: AT+CLCC
> Subscr 3 Receive: AT+CLCC
> Subscr 3 Receive: +CLCC: 1,1,0,0,0,"<Sub2>",145
> Subscr 3 Receive:
> Subscr 3 Receive: OK
> ***************************************
> Comment: Terminate the active call no. 2 (Sub2 - Sub3)
> ***************************************
> Subscr 2 Send: AT+CHLD=12
> Subscr 2 Receive: AT+CHLD=12
> Subscr 2 Receive: OK
> Subscr 3 Receive:
> Subscr 3 Receive: NO CARRIER
> ***************************************
> Comment: Request list of current calls
> ***************************************
> Subscr 1 Send: AT+CLCC
> Subscr 1 Receive: AT+CLCC
> Subscr 1 Receive: +CLCC: 1,0,0,0,0,"<Sub2>",129
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> Subscr 2 Send: AT+CLCC
> Subscr 2 Receive: AT+CLCC
> Subscr 2 Receive: +CLCC: 1,1,0,0,1,"<Sub1>",145
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> Subscr 3 Send: AT+CLCC
> Subscr 3 Receive: AT+CLCC
> Subscr 3 Receive: OK
> ***************************************
> Comment: Incoming voice call Sub3-->Sub2
> ***************************************
> Subscr 3 Send: ATD<Sub2>;
> Subscr 3 Receive: ATD<Sub2>;
> Subscr 2 Receive:
> Subscr 2 Receive: +CCWA: "<Sub3>",145,1,,0
> ***************************************
> Comment: 2nd call accepted by Sub2, Sub1 on hold, Sub2 connected with Sub3
> ***************************************
> Subscr 2 Send: AT+CHLD=2
> Subscr 2 Receive: AT+CHLD=2
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> Subscr 3 Receive:
> Subscr 3 Receive: OK
> ***************************************
> Comment: Request list of current calls
> ***************************************
> Subscr 1 Send: AT+CLCC
> Subscr 1 Receive: AT+CLCC
> Subscr 1 Receive: +CLCC: 1,0,0,0,0,"<Sub2>",129
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> Subscr 2 Send: AT+CLCC
> Subscr 2 Receive: AT+CLCC
> Subscr 2 Receive: +CLCC: 1,1,1,0,1,"<Sub1>",145
> Subscr 2 Receive: +CLCC: 2,1,0,0,0,"<Sub3>",145
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> Subscr 3 Send: AT+CLCC
> Subscr 3 Receive: AT+CLCC
> Subscr 3 Receive: +CLCC: 1,0,0,0,0,"<Sub2>",129
> Subscr 3 Receive:
> Subscr 3 Receive: OK
> ***************************************
> Comment: Add the held call to the active call
> ***************************************
> Subscr 2 Send: AT+CHLD=3
> Subscr 2 Receive: AT+CHLD=3
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> ***************************************
> Comment: Request list of current calls
> ***************************************
> Subscr 1 Send: AT+CLCC
> Subscr 1 Receive: AT+CLCC
> Subscr 1 Receive: +CLCC: 1,0,0,0,0,"<Sub2>",129
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> Subscr 2 Send: AT+CLCC
> Subscr 2 Receive: AT+CLCC
> Subscr 2 Receive: +CLCC: 1,1,0,0,1,"<Sub1>",145
> Subscr 2 Receive: +CLCC: 2,1,0,0,1,"<Sub3>",145
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> Subscr 3 Send: AT+CLCC
> Subscr 3 Receive: AT+CLCC
> Subscr 3 Receive: +CLCC: 1,0,0,0,0,"<Sub2>",129
> Subscr 3 Receive:
> Subscr 3 Receive: OK
> ***************************************
> Comment: Terminate all active calls
> ***************************************
> Subscr 2 Send: AT+CHLD=1
> Subscr 2 Receive: AT+CHLD=1
> Subscr 2 Receive: OK
> Subscr 2 Receive:
> Subscr 2 Receive: NO CARRIER
> Subscr 1 Receive:
> Subscr 1 Receive: NO CARRIER
> Subscr 3 Receive:
> Subscr 3 Receive: NO CARRIER
> ***************************************
> Comment: Request list of current calls
> ***************************************
> Subscr 1 Send: AT+CLCC
> Subscr 1 Receive: AT+CLCC
> Subscr 1 Receive: OK
> Subscr 2 Send: AT+CLCC
> Subscr 2 Receive: AT+CLCC
> Subscr 2 Receive: OK
> Subscr 3 Send: AT+CLCC
> Subscr 3 Receive: AT+CLCC
> Subscr 3 Receive: OK

> 2.7.3.4 | Multiparty - call reject

> This section comprises the subsections Description, Used AT Commands, Flow Chart, Hints and Example. To move to these subsections please use the Navigation Frame or the appropriate buttons on the toolbar.

> 2.7.3.4.1 | Description

> This chapter describes all the steps needed to reject a waiting call within the Multiparty supplementary service call waiting and call hold. At least three subscribers are involved.
> At first two subscribers are connected. Then, a third subscriber is calling subscriber 2.
> There are two ways to reject a waiting call, Subscriber 2 can reject the waiting call with

> • | AT+CHLD=0 (Figure 42) or

> • | AT+CHLD=1x (Figure 43).

> However, if subscriber 2 uses ATH the active call between subscriber 1 and 2 will be disconnected, and the waiting caller (subscriber 3) can be accepted with ATA or rejected with ATH (see normal call handling, example in Figure 50).

> 2.7.3.4.2 | Used AT commands

> Command | Explanation
> ATA | Answer a call
> ATD | Mobile originated call to dial a number
> AT+CHLD | Call hold and multiparty
> AT+CLCC | Returns a list of current calls

> For further details about the commands see [2].

> 2.7.3.4.3 | Flowchart

> Figure 41: Multiparty - call reject - alternative 1
> Figure 42: Multiparty - call reject - alternative 2

> 2.7.3.4.4 | Hints

> GCF-CC note: *# sequences the user enters on the keypad shall be transmitted over the AT interface without any conversion. Also, GCF test cases require that *# sequences can be entered during a call.

> 2.7.3.4.5 | Example

> Example 1:
> ***************************************
> Comment: Multiparty - call reject- ATH
> ***************************************
> ***************************************
> Comment: Establish voice call Sub1-->Sub2
> ***************************************
> Subscr 1 Send: ATD<Sub2>;
> ***************************************
> Comment: Sub2: waiting for CRING
> ***************************************
> Subscr 1 Receive: ATD<Sub2>;
> Subscr 2 Receive:
> Subscr 2 Receive: +CRING: VOICE
> ***************************************
> Comment: Sub2: accept waiting call of Sub1
> ***************************************
> Subscr 2 Send: ATA
> Subscr 2 Receive: ATA
> Subscr 2 Receive: OK
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> ***************************************
> Comment: Establish voice call Sub3-->Sub2
> ***************************************
> Subscr 3 Send: ATD<Sub2>;
> Subscr 3 Receive: ATD<Sub2>;
> Subscr 2 Receive:
> Subscr 2 Receive: +CCWA: "<Sub3>",145,1,,0
> ***************************************
> Comment: Terminate the active call
> ***************************************
> Subscr 2 Send: ATH
> Subscr 2 Receive: ATH
> Subscr 2 Receive: OK
> Subscr 2 Receive:
> Subscr 2 Receive: +CRING: VOICE
> Subscr 1 Receive:
> Subscr 1 Receive: NO CARRIER
> ***************************************
> Comment: Waiting call may be the last active call
> Comment: Reject the active call
> ***************************************
> Subscr 2 Send: ATH
> Subscr 2 Receive: ATH
> Subscr 2 Receive: OK
> Subscr 3 Receive:
> Subscr 3 Receive: NO CARRIER
> Example 2:
> ***************************************
> Comment: Multiparty - call reject- AT+CHLD=0
> ***************************************
> ***************************************
> Comment: Establish voice call Sub1-->Sub2
> ***************************************
> Subscr 1 Send: ATD<Sub2>;
> ***************************************
> Comment: Sub2: waiting for CRING
> ***************************************
> Subscr 1 Receive: ATD<Sub2>;
> Subscr 2 Receive:
> Subscr 2 Receive: +CRING: VOICE
> ***************************************
> Comment: Sub2: accept waiting call of Sub1
> ***************************************
> Subscr 2 Send: ATA
> Subscr 2 Receive: ATA
> Subscr 2 Receive: OK
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> ***************************************
> Comment: Establish voice call Sub3-->Sub2
> ***************************************
> Subscr 3 Send: ATD<Sub2>;
> Subscr 3 Receive: ATD<Sub2>;
> Subscr 2 Receive:
> Subscr 2 Receive: +CCWA: "<Sub3>",145,1,,0
> ***************************************
> Comment: Set UDUB=user determined user busy, i.e. reject a waiting call
> ***************************************
> Subscr 2 Send: AT+CHLD=0
> Subscr 2 Receive: AT+CHLD=0
> Subscr 2 Receive: OK
> Subscr 3 Receive:
> Subscr 3 Receive: BUSY
> Example 3:
> ***************************************
> Comment: Multiparty - call reject- AT+CHLD=12
> ***************************************
> ***************************************
> Comment: Establish voice call Sub3-->Sub2
> ***************************************
> Subscr 3 Send: ATD<Sub2>;
> Subscr 3 Receive: ATD<Sub2>;
> Subscr 2 Receive:
> Subscr 2 Receive: +CCWA: "<Sub3>",145,1,,0
> Subscr 2 Send: AT+CLCC
> Subscr 2 Receive: AT+CLCC
> Subscr 2 Receive: +CLCC: 1,1,0,0,0,"<Sub1>",145
> Subscr 2 Receive: +CLCC: 2,1,5,0,0,"<Sub3>",145
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> ***************************************
> Comment: Terminate the call with index 2 (=waiting call)
> ***************************************
> Subscr 2 Send: AT+CHLD=12
> Subscr 2 Receive: AT+CHLD=12
> Subscr 2 Receive: OK
> Subscr 3 Receive:
> Subscr 3 Receive: NO CARRIER
> ***************************************
> Comment: Disconnect the active call
> ***************************************
> Subscr 2 Send: ATH
> Subscr 2 Receive: ATH
> Subscr 2 Receive: OK
> Subscr 1 Receive:
> Subscr 1 Receive: NO CARRIER