4.2 Outgoing call set-up (MS originating call)

29.0103GPPInformation element mapping between Mobile Station - Base Station System (MS - BSS) and Base Station System - Mobile-services Switching Centre (BSS - MSC)Release 17Signalling Procedures and the Mobile Application Part (MAP)TS

Figure 3 shows those elements of a call set-up sequence which require interworking between BSSAP and MAP. BSSAP messages which do not require interworking with MAP are not shown.

MS MSC VLR

CM SERVICE REQUEST

———————–> MAP_PROCESS_ACCESS_REQUEST request

———————————->

+————————–+

| Possibly |

| identification procedure/|

| authentication procedure |

+————————–+

MAP_SET_CIPHERING_MODE request

<———————————-

(Note 1)

MAP_PROCESS_ACCESS_REQUEST response

CM SERVICE ACCEPT <———————————

<———————– positive result (Note 1)

(Note 2)

CIPHER MODE COMMAND

<———————–

(Note 2)

CIPHER MODE COMPLETE

———————–>

MAP_FORWARD_NEW_TMSI request

TMSI REALLOCATION COMMAND <———————————-

<———————– (Note 3)

TMSI REALLOCATION COMPLETE

———————–> MAP_FORWARD_NEW_TMSI response

———————————->

MAP_PROCESS_ACCESS_REQUEST response

CM SERVICE REJECT <———————————

<———————– negative result, MAP_U/P_ABORT,

(Note 4) MAP_NOTICE, MAP_CLOSE

SETUP (Note 5)

———————–> MAP_SEND_INFO_FOR_OUTGOING_CALL

———————————->

request

MAP_COMPLETE_CALL request

CALL PROCEEDING <———————————-

<———————–

MAP_SEND_INFO_FOR_OUTGOING_CALL

RELEASE COMPLETE <———————————-

<———————– response, MAP_U/P_ABORT,

(Note 6) MAP_NOTICE, MAP_CLOSE

Figure 3: Part of outgoing call set-up sequence

NOTE 1: If the MSC received a MAP_SET_CIPHERING_MODE request, it stores it until it receives the MAP_PROCESS_ACCESS_ REQUEST response.

NOTE 2: CM SERVICE ACCEPT is sent only if the ciphering procedure is not invoked.

NOTE 3: TMSI reallocation need not be sequenced with other messages, but should be sent after ciphering.

NOTE 4: CM SERVICE REJECT is sent as a result of a user error parameter in the MAP_PROCESS_ACCESS_REQUEST response, or termination of the MAP dialogue.

NOTE 5: The SETUP message is sent after the MS has either received a CM SERVICE ACCEPT or sent a CIPHER MODE COMPLETE.

NOTE 6: RELEASE COMPLETE is sent as a result of a user error parameter in the MAP_SEND_INFO_FOR_OUTGOING_CALL response, or termination of the MAP dialogue.

The procedure can be considered in two parts: the handling of the CM SERVICE REQUEST and the handling of the SETUP request.

The procedure is initiated by the MS sending a CM SERVICE REQUEST message. The MSC will forward the service request to the VLR in the MAP_PROCESS_ACCESS_REQUEST request. The VLR may then invoke other operations, e.g. authentication and identification. These operations are defined in clauses 3.4 and 3.5.

If there is a positive outcome for the CM SERVICE REQUEST procedure, the VLR always sends a MAP_PROCESS_ACCESS_REQUEST response. If the request is for a first MM-connection and ciphering is required, the MAP_PROCESS_ACCESS_REQUEST response is preceded by a MAP_SET_CIPHERING_MODE request. In this case the MSC sends a CIPHER MODE COMMAND towards the MS. The interworking for cipher mode setting is described in clause 4.4. If the request is for an additional MM-connection or for a first MM-connection where ciphering is not required, then the positive MAP_PROCESS_ACCESS_ REQUEST response causes the MSC to send a CM SERVICE ACCEPT message to the MS. After cipher mode setting has been completed or the CM SERVICE ACCEPT message has been returned, the MS will send the SETUP (or EMERGENCY SETUP) message and information retrieval takes place as shown.

A negative outcome for the MAP_PROCESS_ACCESS_REQUEST procedure can be signalled by a MAP_PROCESS_ACCESS_REQUEST response containing a user error parameter, or by terminating the MAP dialogue between the MSC and the VLR.

A positive outcome for the call setup procedure is indicated by a MAP_COMPLETE_CALL request from the VLR to the MSC, which causes the MSC to send a CALL PROCEEDING message towards the MS.

A negative outcome for the call setup procedure can be signalled by a MAP_SEND_INFO_FOR_INCOMING_CALL response or by terminating the dialogue between the MSC and the VLR.

Information element mapping is required between the messages:

– CM SERVICE REQUEST to MAP_PROCESS_ACCESS_REQUEST request;

– SETUP to MAP_SEND_INFO_FOR_OUTGOING CALL request;

– MAP_SEND_INFO_FOR_OUTGOING_CALL response, MAP_U/P_ABORT, MAP_NOTICE or premature MAP_CLOSE to RELEASE COMPLETE or CM SERVICE REJECT.

The information contained in the MAP_COMPLETE_CALL request is not transmitted on the radio interface but is used in the MSC for connecting the call.

The conversion of information elements is as follows:

—————————————————————

| 48.008/24.008 29.002 |Notes

——–┼————————————————┼—–

Forward | COMPLETE LAYER 3 INFO MAP_PROCESS_ACCESS_ |

| (CM SERVICE REQUEST) REQUEST request |

| |

| CM Service type CM Service type | 1

| Ciphering key CKSN |

| sequence number |

| Mobile identity TMSI or IMSI or IMEI |

| Mobile station |

| Classmark 2 – |

| |

| Cell identifier Current LA Id | 4

| Chosen channel – |

| – Access Connection |

| Status | 3

——–┼————————————————┼—–

Positive| DTAP(CM SERVICE ACCEPT) MAP_PROCESS_ACCESS_ |

result | REQUEST response | 2

——–┼————————————————┼—–

Negative| DTAP(CM SERVICE REJECT) MAP_PROCESS_ACCESS_ |

result | REQUEST response |

| |

| IMSI unknown in VLR Unidentified |

| Subscriber |

[ | Requested service ??????? |

| option not |

| subscribed |]

| Illegal ME Illegal equipment |

| Network failure System failure |

| Network failure MAP_U/P_ABORT

| Network failure MAP_NOTICE |

| Network failure MAP_CLOSE |

——–┼————————————————┼—–

| DTAP(AUTHENTICATION MAP_PROCESS_ACCESS_ |

| REJECT) REQUEST response |

| |

| Illegal subscriber |

——–┴————————————————┴—–

NOTE 1: Indicates, in this case, a mobile originating call establishment or an emergency call establishment.

NOTE 2: The CM SERVICE ACCEPT is sent when the ciphering procedure is not invoked.

NOTE 3: Indicates whether or not an RR-connection exists and whether or not ciphering has been started.

NOTE 4: The Current LA Id parameter is derived by the MSC from the Cell identifier information element.

—————————————————————

| 24.008 29.002 |Notes

——–┼————————————————┼—–

Forward | SETUP MAP_SEND_INFO_FOR_ |

message | OUTGOING_CALL request |

| |

| BC repeat indicator – |

| Bearer capability 1 – | 3

| Bearer capability 2 – | 3

| Calling party subaddress – |

| Called party BCD number Called Number |

| Called party subaddress – |

| LLC repeat indicator – |

| Low layer compatibility I – |

| Low layer compatibility II – |

| HLC repeat indicator – |

| High layer compatibility i – |

| High layer compatibility ii – |

| – Bearer service | 3

| – Teleservice | 3

| Facility – | 1

| – CUG index | 4

| – Suppress pref CUG | 4

| – Suppress CUG OA | 4

| User-user – |

| SS version – |

| CLIRO flag – |

——–┼————————————————┼—–

Positive| |

result | | 2

——–┼————————————————┼—–

Negative| RELEASE COMPLETE MAP_SEND_INFO_FOR_ |

result | OUTGOING_CALL response|

| |

| 3GPP TS 24.010 Call Barred |

| Barring Service |

| Active |

| Operator determined Call Barred |

| barring Operator Determined|

| Barring |

| Network out of order Data Missing |

| Network out of order Unexpected Data Value |

| Network out of order System Failure |

| Bearer capability Bearer service not |

| not authorized provisioned |

| Bearer capability Teleservice not |

| not authorized provisioned |

| [User not member of CUG] CUG reject |

| |

| Network out of order MAP_U/P_ABORT |

| Network out of order MAP_NOTICE |

| Network out of order MAP_CLOSE |

——–┴————————————————┴—–

NOTE 1: If the Facility IE contains CUG information, the CUG information is transferred to the VLR in the MAP_SEND_INFO_FOR_OUTGOING_CALL service; any other information contained in a Facility IE is transferred to the VLR in a MAP Supplementary Services related service.

NOTE 2: The call setup parameters retrieved from the VLR are not sent to the MS. The parameters are carried in the MAP_COMPLETE_CALL service.

NOTE 3: The bearer capabilities can be used to derive the bearer/tele service.

NOTE 4: CUG information is derived from the contents of the Facility IE.