> 7.22 | AT^SLCC Extended list of current calls

> AT^SLCC covers essentially the same information as GSM 07.07 command AT+CLCC, with the following extensions:

> • | The execute command response contains the additional parameter <traffic channel assigned> which indicates whether the call has been assigned a traffic channel by the network and transmission of DTMF tones is possible.

> • | The additional write command allows to activate Event reporting for the list of current calls. If event reporting is active for an interface, a call status transition (cf. Call Status Information) and (if desired) the assignment of a traffic channel will generate an event report indication to this interface. In order to receive this event report as an URC, the URC presentation mode for this interface has to be configured with AT+CMER. Interface settings are saved with AT&W and can be displayed with AT&V The frequency of event report generation can be configured with AT command AT^SCFG. Refer to Call Status Information for further detail on the configuration options.

> • | The additional read command returns an indication whether event reporting is active for the current interface. Mind that the URC will be displayed only if the URC presentation mode for the interface concerned has been configured with AT+CMER.

> • | The exec command returns, like AT+CLCC, a list of current calls. If the command is successful, but no calls are available, no information response is sent to the TE.

> Syntax

> Test Command AT^SLCC=?
> Response(s)
> ^SLCC: (list of supported<n>s)
> OK

> Read Command AT^SLCC?
> Response(s)
> ^SLCC: <n>
> OK

> Exec Command AT^SLCC
> Response(s)
> [^SLCC:<idx>, <dir>, <stat>, <mode>, <mpty>, <traffic channel assigned>[, <number>, <type>[, <alpha>]]]
> [^SLCC:<idx>, <dir>, <stat>, <mode>, <mpty>, <traffic channel assigned>[, <number>, <type>[, <alpha>]]]
> [^SLCC:...]
> OK
> ERROR
> +CME ERROR

> Write Command AT^SLCC=[<n>]
> Response(s)
> OK
> ERROR
> +CME ERROR: <err>

> Reference(s) |  | PIN |  | ASC0 | ASC1 | USB | MUX1 | MUX2 | MUX3 |  |  | Charge | Q | Last
> Siemens |  | + |  | + | + | + | + | + | + |  |  | - | - | -

> Unsolicited Result Code
> Unsolicited Call Status information
> if the list of current calls is empty:
> ^SLCC:
> if one or more calls are currently in the list:
> ^SLCC: <idx>, <dir>, <stat>, <mode>, <mpty>, <traffic channel assigned>[, <number>, <type>[, <alpha>]]
> [^SLCC: <idx>, <dir>, <stat>, <mode>, <mpty>, <traffic channel assigned>[, <number>, <type>[, <alpha>]]]
> [...]
> ^SLCC:
> URC "^SLCC" displays the list of current calls as displayed with the execute command AT^SLCC. The list is displayed in the state it has at the time of display, not in the state it had when the signal was generated.
> The URC's occurrence indicates call status changes for any of the calls in the list of current calls.
> Please refer to Call Status Information and AT^SCFG for further information about the configuration of this URC.
> Event reporting can be enabled separately for each interface. Interface settings are saved with AT&W and can be displayed with AT&V. Additionally, The URC presentation mode for the interface must be configured with AT+CMER.
> Depending on the value of AT^SCFG setting <sucs>, Indicator "^SLCC" will be issued (if configured with write command AT^SLCC and AT+CMER)

> • | when a state transition ends in state "active" or in state "unknown" (if AT^SCFG setting <sucs>="restricted")

> • | when any state transition (including transitions beginning or ending in state "unknown") occurs in the list of active calls, or when a traffic channel is established (if AT^SCFG setting <sucs>="verbose").

> If multiple displays of identical list configurations occur, this happens because of short intermediate states of the list, that have already been overridden by new transitions and states. Thus, it is guaranteed that the configuration displayed is always the current configuration at the time of the last display.
> The list of active calls displayed with this URC will always be terminated with an empty line preceded by prefix "^SLCC: ", in order to indicate the end of the list.
> Parameter Description

> <n>(num)(&W)(&V)

> [0](&F)
> Presentation of URC "^SLCC" disabled
> 1
> Presentation of URC "^SLCC" enabled

> <idx>(num)

> Call identification number as described in GSM02.30 subclause 4.5.5.1; this number can be used in AT+CHLD command operations.

> <dir>(num)

> 0
> Mobile originated call (MOC)
> 1
> Mobile terminated call (MTC)

> <stat>(num)

> state of the call
> 0
> Active
> 1
> Held
> 2
> Dialing (MOC)
> 3
> Alerting (MOC)
> 4
> Incoming (MTC)
> 5
> Waiting (MTC)

> <mode>(num)

> bearer/teleservice
> 0
> Voice
> 1
> Data
> 2
> Fax
> 3
> Voice followed by data, voice mode (only in connection with single numbering scheme AT+CSNS)
> 4
> Alternating voice/data, voice mode (only in connection with single numbering scheme AT+CSNS)
> 5
> Alternating voice/fax, voice mode (only in connection with single numbering scheme AT+CSNS)
> 6
> Voice followed by data, data mode (only in connection with single numbering scheme AT+CSNS)
> 7
> Alternating voice/data, data mode (only in connection with single numbering scheme AT+CSNS)
> 8
> Alternating voice/fax, fax mode (only in connection with single numbering scheme AT+CSNS)
> 9
> Unknown

> <mpty>(num)

> 0
> Call is not one of multiparty (conference) call parties
> 1
> Call is one of multiparty (conference) call parties

> <traffic channel assigned>(num)

> 0
> No traffic channel assigned. Transmission of DTMF tones not possible.
> 1
> Traffic channel is assigned and the progress indicator IE has been received (call setup) or a voice connection has an active state. The parameter indicates that the audio path is activated. DTMF tones can be sent with AT+VTS.

> <number>(str)

> Phone number in format specified by <type>

> <type>(num)

> Type of address octect
> 145
> Dialing string <number> includes international access code character '+'
> 128
> number is restricted
> 129
> Otherwise

> <alpha>(str)(+CSCS)

> Alphanumeric representation of <number> corresponding to the entry found in phonebook.
> The maximum displayed length of <alpha> is 16 characters. If <alpha> has more than 16 characters, only the first 15 characters will be displayed. To indicate an overflow, a special character will be used as the 16th character. This will be a space if the character set selected with AT+CSCS is 'GSM', or 'E400' if the character set is 'UCS2'.
> Due to time constraints on the necessary evaluation of the phonebook, this parameter may show a default value during early call phases (e.g. for <stat>= "dialing", "incoming" or "alerting"), even if a phonebook entry is present for the number concerned.
> Notes

> • | Teleservices other than voice, data, fax are not fully supported by ME. They are used only in connection with the handling for AT+CSNS, and may therefore occur in parameter <mode> for mobile terminated calls.

> • | If a URC "^SLCC" in verbose mode (see AT^SCFG) has been buffered while the interface was in dedicated mode (depending on the settings of AT+CMER parameter <bfr>), each buffered event indicator will be output as a separate URC after the interface returns to idle mode. However, the output will deliver the list of current calls in the "current" state (at the time when the output is generated), possibly leading to multiple displays of identical list configurations.

> • | Some parameters of the AT+CHLD command, as well as some situations where the call status in the network changes very quickly (e.g. the transition between <stat>= "unknown", "dialing" and "alerting" for a call to a reachable subscriber within the registered network) may lead to quasi-simultaneous changes to the states of one or several calls in the list, possibly leading to multiple displays of identical list configurations.

> • | If multiple displays of identical list configurations occur, this happens because of intermediate states of the list, that have already been overridden by new transitions and states. Thus, it is guaranteed that the configuration displayed in such cases is the current configuration at the time of the last display.

> • | It is adviseable to receive URC "^SLCC" on an interface that is not used for call initiation, if verbose output is configured. If only voice calls are expected, a setting of AT^SM20= 0 may be used alternatively in order to keep the call from blocking the interface.

> Examples

> EXAMPLE 1 |

> ^SYSSTART
> at+cpin=9999
> OK
> +CREG: 2
> +CREG: 1,"0145","0016" | We are now registered.
> at^sm20=0 | Command ATD for an outgoing voice call will terminate immediately with response "OK".
> OK
> atd"1234567"; | We start a voice call.
> OK | "OK" response is issued immediately because of setting AT^SM20="0".
> ^SLCC: 1,0,2,0,0,0,"1234567",129,"Called Party" | MO voice call starts, paging B-party.
> ^SLCC: | End of current list
> ^SLCC: 1,0,2,0,0,1,"1234567",129,"Called Party" | Traffic channel established, network may now transmit network announcements, ME may now transmit DTMF tones.
> ^SLCC: | End of current list
> ^SLCC: 1,0,3,0,0,1,"1234567",129,"Called Party" | Call is now ringing at B-Party.
> ^SLCC: | End of current list
> ^SLCC: 1,0,0,0,0,1,"1234567",129,"Called Party" | B-Party has accepted the call, connection established.
> ^SLCC: | End of current list.
> atd23456; | We start a second voice call.
> OK | "OK" response is issued immediately because another call is already active (cf. ATD).
> ^SLCC: 1,0,1,0,0,0,"1234567",129,"Called Party" | The active call is automatically put on hold, triggering the display of the list.
> ^SLCC: 2,0,2,0,0,1,"23456",129 | The second call has already started before the indication for the held call could be displayed
> ^SLCC: | End of current list.
> ^SLCC: 1,0,1,0,0,0,"1234567",129,"Called Party" | The identical list is displayed again, triggered by the start of the second voice call.
> ^SLCC: 2,0,2,0,0,1,"23456",129 | The status of the second list entry has already been displayed with the previous URC.
> ^SLCC: | End of current list.
> ^SLCC: 1,0,1,0,0,0,"1234567",129,"Called Party" | The held call doesn't change status right now.
> ^SLCC: 2,0,3,0,0,1,"23456",129 | The second call is now alerting the B-Party.
> ^SLCC: | End of current list.
> ^SLCC: 1,0,0,0,0,1,"1234567",129,"Called Party" | The held call doesn't change status right now.
> ^SLCC: | End of current list: the B-Party of the second call has not accepted the call in time, the second call has ended.
> NO CARRIER | The second call has ended.
> ^SLCC: | list is now empty: B-Party has ended the first call.
> NO CARRIER | The first call has ended.

> EXAMPLE 2 |

> ^SLCC: 1,1,4,0,0,1,"1234567",129 | Incoming voice call is signalled. Display is triggered by the incoming call, but the current status of the call at the time of display already comprises an active traffic channel.
> ^SLCC: | End of current list.
> RING | Incoming call is signalled.
> ^SLCC: 1,1,4,0,0,1,"1234567",129 | The incoming call had a traffic channel assigned from the start. This second identical display is triggered by the traffic channel assignment. Since the traffic channel was already indicated in the previous URC, both instances of the URC contain identical information.
> ^SLCC: | End of current list.
> RING | Incoming call is signalled.
> ata | Incoming call is accepted.
> OK | call is established.
> ^SLCC: 1,1,0,0,0,1,"1234567",129 | The call is now active.
> ^SLCC: | End of current list.
> ath | Hang up the call.
> OK | hang up complete.
> ^SLCC: | The list of current calls is empty again.