23.7 The mobile terminated short message transfer procedure for VGCS

29.0023GPPMobile Application Part (MAP) specificationRelease 17TS

The mobile terminated short message transfer for VGCS procedure is used for forwarding a short message from a Service Centre to the group call anchor MSC. The message flow for the mobile terminated short message transfer procedure for VGCS is shown in figure 23.7/1.

Figure 23.7/1: Mobile terminated short message for VGCS service procedures

1) Short Message (3GPP TS 23.040).

2) TCAP BEGIN (*)

3) TCAP CONTINUE (*)

4) MAP_MT_FORWARD_SM_FOR_VGCS.

5) GCR_SMS_INTERROGATION (3GPP TS 43.068).

6) GCR_SMS_INTERROGATION_ACK (3GPP TS 43.068).

7) MAP_MT_FORWARD_SM_FOR_VGCS_ACK.

8) Short Message Acknowledgement (3GPP TS 23.040).

(*) If

a)
– the capacity of a message signal unit in the lower layers of the protocol is enough to carry the content of the MAP_OPEN request and the content of the MAP_MT_FORWARD_SM_FOR_VGCS request in a single TC message,

and

b) the SMS Gateway MSC operator and the serving node (Anchor-MSC) operator
agreed not to use the TCAP handshake countermeasure against SMS fraud for
messages exchanged between their networks (see 3GPP TS 33.204 [34a])

then
the TCAP handshake may be omitted.

23.7.1 Procedure in the SMS-GMSC

The process starts when the SMS-GMSC receives an SC_RP_MT_DATA indication from a Service Centre. The MAP process invokes macros not defined in this clause; the definitions of these macros can be found as follows:

Receive_Open_Cnf see clause 25.1.2;

Check_Confirmation see clause 25.2.2.

The mobile terminated short message transfer for VGCS process in the SMS-GMSC is shown in figure 23.7/2.

23.7.2 Procedure in the Anchor MSC

The process starts when the MSC receives a dialogue opening request with the application context shortMsgMT-Relay-VGCS-Context. The MAP process invokes macros not defined in this clause; the definitions of these macros can be found as follows:

Receive_Open_Ind see clause 25.1.1;

The mobile terminated short message transfer for VGCS process in the Anchor MSC is shown in figure 23.7/3

Procedure MT_SM_VGCS_GMSC sheet 1: The decision box "TCAP Handshake required" takes the "yes" or "no" exit depending on agreements between the Serving MSC’s operator and the SMS Gateway MSC’s operator (see 3GPP TS 33.204 [34a]).

Figure 23.7/2 (sheet 1 of 2): Process MT_SM_VGCS_GMSC

Figure 23.7/2 (sheet 2 of 2): Process MT_SM_VGCS_GMSC

Figure 23.7/3 (sheet 1 of 2): Process MT_SM_VGCS_Anchor MSC

Figure 23.7/3 (sheet 2 of 2): Process MT_SM_VGCS_Anchor MSC