> 2.9.5 | Further scenarios for outgoing CSD 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.

> 2.9.5.1 | Description

> The following scenario considers all AT commands used by the two remote parties involved in the data connection and, in addition, describes the handling of further waiting voice and data calls.
> When a third subscriber calls one of the other two (while the called subscriber has not enabled Call waiting) the call from the third subscriber is not signaled to the called subscriber.

> 2.9.5.2 | Used AT commands

> Command | Explanation
> ATD | Mobile originated call to dial a number
> ATH | Disconnect existing connection
> ATA | Answer a call
> +++ | Switch from data mode to command mode
> ATO | Switch from command mode to data mode / PPP online mode

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

> 2.9.5.3 | Flow chart

> Figure 58: Call handling for CSD – part 1
> Figure 59: Call handling for CSD - part 2
> Figure 60: Call handling for CSD - part 3

> 2.9.5.4 | Hints

> Not applicable.

> 2.9.5.5 | Example

> ***************************************
> Comment: Call handling
> ***************************************
> ***************************************
> Comment: Establish data call Sub1-->Sub2
> ***************************************
> Subscr 1 Send: ATD<Sub2>
> ***************************************
> Comment: Sub2: Waiting for RING
> ***************************************
> Subscr 1 Receive: ATD<Sub2>
> Subscr 2 Receive:
> Subscr 2 Receive: RING
> ***************************************
> Comment: Sub2: Reject waiting call of Sub1
> ***************************************
> Subscr 2 Send: ATH
> Subscr 2 Receive: ATH
> Subscr 2 Receive: OK
> Subscr 1 Receive:
> Subscr 1 Receive: NO CARRIER
> ***************************************
> Comment: Establish data call Sub1-->Sub2
> ***************************************
> Subscr 1 Send: ATD<Sub2>
> ***************************************
> Comment: Sub2: Waiting for RING
> ***************************************
> Subscr 1 Receive: ATD<Sub2>
> Subscr 2 Receive:
> Subscr 2 Receive: RING
> ***************************************
> Comment: Sub2: Accept waiting call of Sub1
> ***************************************
> Subscr 2 Send: ATA
> Subscr 2 Receive: ATA
> Subscr 2 Receive:
> Subscr 2 Receive: CONNECT 9600/RLP
> Subscr 1 Receive:
> Subscr 1 Receive: CONNECT 9600/RLP
> ***************************************
> Comment: Try to establish voice call Sub3-->Sub2 without enabled call waiting
> ***************************************
> Subscr 3 Send: ATD<Sub2>;
> Subscr 3 Receive: ATD<Sub2>;
> Subscr 3 Receive:
> Subscr 3 Receive: BUSY
> ***************************************
> Comment: Try to establish data call Sub3-->Sub2 without enabled call waiting
> ***************************************
> Subscr 3 Send: ATD<Sub2>
> Subscr 3 Receive: ATD<Sub2>
> Subscr 3 Receive:
> Subscr 3 Receive: BUSY
> ***************************************
> Comment: Sub1&2: Send data
> ***************************************
> Subscr 1 Send: hello from subscriber1;
> Subscr 2 Receive: hello from subscriber1;
> Subscr 2 Send: hello from subscriber2;
> Subscr 1 Receive: hello from subscriber2;
> ***************************************
> Comment: Switch back to command mode (Sub1)
> ***************************************
> Subscr 1 Send: +++
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> Subscr 2 Receive: +++
> ***************************************
> Comment: Any AT-command
> ***************************************
> Subscr 1 Send: ATI
> Subscr 1 Receive: ATI
> Subscr 1 Receive: SIEMENS
> Subscr 1 Receive: TC35i
> Subscr 1 Receive: REVISION 02.07
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> ***************************************
> Comment: Switch back to online mode (Sub1)
> ***************************************
> Subscr 1 Send: ATO
> Subscr 1 Receive: ATO
> Subscr 1 Receive: CONNECT 9600/RLP
> ***************************************
> Comment: Sub1&2: send data
> ***************************************
> Subscr 1 Send: hello again from subscriber1;
> Subscr 2 Receive: hello again from subscriber1;
> Subscr 2 Send: hello again from subscriber2;
> Subscr 1 Receive: hello again from subscriber2;
> ***************************************
> Comment: Switch back to command mode (Sub2)
> ***************************************
> Subscr 2 Send: +++
> Subscr 1 Receive: +++
> Subscr 2 Receive:
> Subscr 2 Receive: OK
> ***************************************
> 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