23.1 General
29.0023GPPMobile Application Part (MAP) specificationRelease 17TS
The short message service procedures are used to control both mobile originated and mobile terminated short message transfer.
Four procedures exist for short message services:
– mobile originated short message service transfer;
– mobile terminated short message service transfer;
– short message alert procedure;
– short message delivery status report procedure.
The following application context refers to a complex MAP user consisting of several processes:
– shortMessageGatewayContext.
This application context needs a co-ordinating process in the HLR. Additionally a co-ordinating process needed for the mobile originated situation in the MSC, because the A_CM_SERV_REQ message does not distinguish between mobile originated short message transfer and the short message alert procedures.
NOTE: the A_CM_SERV_REQ message is not used for SMS over GPRS. The modelling is based on the assumption that the SGSN will trigger the appropriate process, according to whether an RP_MO_DATA or an RP_SM_MEMORY_AVAILABLE is received over the LLC layer.
When the "SMS in MME" architecture option is supported, the clause 23 and its associated figures applies where HSS replaces HLR and where MME is handled as a MSC, except the procedures between the serving MSC and the VLR which, here, are not applicable to the MME.
NOTE: MSC and MME cannot be both registered as serving nodes for MT SMS at a given time (cf 3GPP TS 23.272 [2])
23.1.1 Mobile originated short message service Co-ordinator for the MSC
The process starts when the MSC receives an A_CM_SERV_REQ message (see 3GPP TS 24.008 [35]), with a CM service type indicating short message service, from the A-interface. The process invokes a macro not defined in this clause; the definition of this macro can be found as follows:
Process_Access_Request_MSC see clause 25.4.1.
If the macro Process_Access_Request_MSC takes the "OK" exit (which means that the MSC has sent an A_CM_SERVICE_ACCEPT to the MS), , the MS initiates mobile originated short message transfer or sends an indication that it has memory available for more short messages.
The SMS Co-ordinator process in the MSC is shown in figure 23.1/1.
23.1.2 Short message Gateway Co-ordinator for the HLR
The process starts when the HLR receives a MAP_OPEN indication using when the application context shortMessageGatewayContext. The MAP process invokes a macro not defined in this clause; the definition of this macro can be found as follows:
Receive_Open_Ind see clause 25.1.1.
The SM Gateway Co-ordinator process in the HLR is shown in figure 23.1/2.
If the Receive_Open_Ind macro takes the Vr exit then HLR shall perform the MAP dialogue as specified for the appropriate application context version. Depending on the subscriber data, handling at the MAP user application level may be performed as specified in clauses 23.3.2 and 23.5.2 of the present document:
Figure 23.1/1 (sheet 1 of 2): Process Co_SMS_MSC
Figure 23.1/1 (sheet 2 of 2): Process Co_SMS_MSC
Figure 23.1/2: Process Co_SM_Gateway_HLR