23.2 The mobile originated short message transfer procedure

09.023GPPMobile Application Part (MAP) specificationTS

The mobile originated short message service procedure is used to forward short message from a mobile subscriber to a Service Centre. The mobile originated short message service procedure is shown in figure 23.2/1.

+—–+ +———–+ +——+ +————-+ +—-+
ª MS ª ª Servicing ª ª VLR ª ªInterworking ª ª SC ª
ª ª ªMSC or SGSNª ª ª ª MSC ª ª ª
+—–+ +———–+ +——+ +————-+ +—-+
ª 1.ª ª ª ª ß
+ – – – – ->ª 2.ª ª ª ß
ª +————>ª ª ª ß
ª ª 3. ª ª ª ß
ª +<————ª ª ª ß
ª ª ª 4.ª ª ß
ª ª————-+————->ª 5.ª ß
ª ª ª + – – – – ->ª ß
ª ª ª ª6. ª ß
ª ª7. ª +<- – – – – ª ß
ª8. +<————+————–ª ª ß
+< – – – – -ª ª ª ª ß
ª ª ª ª ª ß

1) Short Message (GSM 04.11)

2) MAP_SEND_INFO_FOR_MO_SMS (*)

3) MAP_SEND_INFO_FOR_MO_SMS_ACK (*)

4) MAP_MO_FORWARD_SHORT_MESSAGE

5) Short message (TS GSM 03.40)

6) Short message Acknowledgement (TS GSM 03.40)

7) MAP_MO_FORWARD_SHORT_MESSAGE_ACK

8) Short Message Acknowledgment (GSM 04.11)

(*) Messages 2) and 3) are not used by SGSN

Figure 23.2/1: Mobile originated short message transfer

In addition the following MAP services are used:

MAP_PROCESS_ACCESS_REQUEST (see subclause 8.3); (*)

MAP_AUTHENTICATE (see subclause 8.5); (*)

MAP_SET_CIPHERING_MODE (see subclause 8.6); (*)

MAP_PROVIDE_IMSI (see subclause 8.9); (*)

MAP_CHECK_IMEI (see subclause 8.7);

MAP_FORWARD_NEW_TMSI (see subclause 8.9); (*)

MAP_TRACE_SUBSCRIBER_ACTIVITY (see subclause 9.1); (*)

MAP_READY_FOR_SM (see subclause 12.4).

(*) Those messages are not used by SGSN.

23.2.1 Procedure in the servicing MSC

The activation of the MAP_PROCESS_ACCESS_REQUEST service is described in the subclause 25.4.1.

When receiving the short message from the A-interface, the MSC sends the MAP_SEND_INFO_FOR_MO_SMS request to the VLR. As a response the MSC will receive the MAP_SEND_INFO_FOR_MO_SMS confirmation from VLR indicating that:

– the service ends successfully. If the MSC is not itself the IWMSC, the short message transmission towards the IWMSC is initiated using the MAP_MO_FORWARD_SHORT_MESSAGE request;

– the service ends unsuccessfully. The error cause in the MAP_SEND_INFO_FOR_MO_SMS confirmation indicates the reason for the unsuccessful end. The mapping between MAP error causes and RP_ERROR causes is described in TS GSM 03.40.

If there are data errors in the MAP_SEND_INFO_FOR_MO_SMS confirmation, or there is an operation failure in MAP, the RP_ERROR cause network out of order is forwarded to the mobile station.

If the service MAP_MO_FORWARD_SHORT_MESSAGE is started, the MSC will check whether the grouping of MAP_OPEN request and MAP_MO_FORWARD_SHORT_MESSAGE request needs segmentation. If this is the case then the MAP_OPEN request primitive shall be sent first without any associated MAP service request primitive and the dialogue confirmation must be received before the MAP_MO_FORWARD_SHORT_MESSAGE request is sent. As a response to the procedure, the servicing MSC will receive the MAP_MO_FORWARD_SHORT_MESSAGE confirmation from the IWMSC indicating that:

– the short message has been successfully delivered to the Service Centre. The acknowledgement is sent to the mobile station;

– one of several error cases has occurred. The mapping between MAP error causes and RP_ERROR causes is described in TS GSM 03.40. The appropriate indication is provided to the mobile station.

If the procedure failed, a provider error or an abort indication is received. The RP_ERROR cause network out of order is provided to the mobile station.

If the MSC itself is the interworking MSC, the short message is forwarded to the Service Centre. In that case the service MAP_MO_FORWARD_SHORT_MESSAGE is not initiated. The acknowledge message from the Service Centre is forwarded to the mobile station (TS GSM 03.40, TS GSM 04.11).

The mobile originated short message service procedure is shown in figure 23.2/2.

Figure 23.2/2 (sheet 1 of 3): Process MOSM_MSC

Figure 23.2/2 (sheet 2 of 3): Process MOSM_MSC

Figure 23.2/2 (sheet 3 of 3): Process MOSM_MSC

23.2.2 Procedure in the VLR

The MAP_PROCESS_ACCESS_REQUEST indication starts the MAP_PROCESS_ACCESS_REQUEST service in the VLR. The application context in the MAP_OPEN indication is mobile originated short message transfer.

If the service MAP_PROCESS_ACCESS_REQUEST is successful, the VLR waits for the next message from the MSC. When receiving the MAP_SEND_INFO_FOR_MO_SMS indication, the VLR acts as follows:

– if there is incompatibility in the subscription check, the error teleservice not provisioned is returned to the MSC;

– if the short message transfer would contravene operator determined barring, the call barred error with cause operator barring is returned;

– if the short message transfer would contravene the supplementary service call barring conditions in the VLR, the call barred error with cause barring service active is returned.

When the mobile subscriber has passed all checks, the MAP_SEND_INFO_FOR_MO_SMS response is initiated and the procedure is terminated in the VLR. The mobile originated short message transfer procedure in the VLR is shown in figure 23.2/3.

Figure 23.2/3: Process MOSM_VLR

23.2.3 Procedure in the interworking MSC

This procedure applies only when the IWMSC is not the servicing MSC or SGSN.

When receiving a MAP_OPEN indication primitive that is not associated with any MAP service indication primitive and if the dialogue is accepted, the MAP service-user in the interworking MSC issues a MAP_DELIMITER request primitive in order to trigger the local MAP service-provider to confirm the dialogue. Then a MAP_MO_FORWARD_SHORT_MESSAGE indication shall be received.

When a MAP_MO_FORWARD_SHORT_MESSAGE indication is correctly received, the Interworking MSC invokes forwarding of the short message to the Service Centre. If invalid data content is detected, an unexpected data value error or a data missing error is returned to the servicing MSC or SGSN.

The outcome of the procedure with the Service Centre is awaited before a MAP_MO_FORWARD_SHORT_MESSAGE response is given back to the servicing MSC or SGSN:

– if a short message is accepted by the Service Centre, an acknowledgement is sent back to the servicing MSC or SGSN;

– if the Service Centre is not identified, the SM Delivery Failure error is returned to the servicing MSC or SGSN;

– if the Service Centre returns an error indication, the SM Delivery Failure error is returned to the servicing MSC with the error cause and any diagnostic information received from the Service Centre;

– if the short message cannot be forwarded to the Service Centre or the procedure towards the Service Centre fails for some reason, a system failure error is sent to the servicing MSC or SGSN.

The mobile originated short message service transfer in the IWMSC is shown in figure 23.2/4.

Figure 23.2/4: Process MOSM_IWMSC

23.2.4 Procedure in the servicing SGSN

When receiving the short message from the MS, the SGSN acts as follows:

– if there is incompatibility in the subscription check, the RP_ERROR cause requested facility not subscribed is provided to the mobile station;

– if the short message transfer would contravene operator determined barring, the RP_ERROR cause operator determined barring is provided to the mobile station;

NOTE: The RP_ERROR causes are described in TS GSM 04.11

– if no error is detected, the short message transmission towards the IWMSC is initiated using the MAP_MO_FORWARD_SHORT_MESSAGE request.

If the service MAP_MO_FORWARD_SHORT_MESSAGE is started, the SGSN will check whether the grouping of MAP_OPEN request and MAP_MO_FORWARD_SHORT_MESSAGE request needs segmentation.

If this is the case then the MAP_OPEN request primitive shall be sent first without any associated MAP service request primitive and the dialogue confirmation must be received before the MAP_MO_FORWARD_SHORT_MESSAGE request is sent. As a response to the procedure, the servicing SGSN will receive the MAP_MO_FORWARD_SHORT_MESSAGE confirmation from the IWMSC indicating that:

– the short message has been successfully delivered to the Service Centre. The acknowledgement is sent to the mobile station;

– one of several error cases has occurred. The mapping between MAP error causes and RP_ERROR causes is described in TS GSM 03.40. The appropriate indication is provided to the mobile station.

If the procedure failed, a provider error or an abort indication is received. The RP_ERROR cause network out of order is provided to the mobile station.

The mobile originated short message service procedure is shown in figure 23.2/5

Figure 23.2/5 (sheet 1 of 3): Process MOSM_SGSN

Figure 23.2/5 (sheet 2 of 3): Process MOSM_SGSN

Figure 23.2/5 (sheet 3 of 3): Process MOSM_SGSN