Content for TS 23.540 Word version: 19.0.0

1… 4… 5… 5.1.3 5.1.4 5.1.5 5.1.6 5.1.7… 5.1.7.2.3… 5.1.7.3.2 5.1.7.3.3 5.1.7.3.4 5.1.7.3.5 5.1.7.4 5.1.8… 5.2… 6…

5.2 Procedure for SBI-based MO SMS 5.2.1 General 5.2.2 Procedure for Successful Mobile Originated short message transfer 5.2.3 Unsuccessful Mobile Originated short message transfer 5.2.4 MSISDN-less MO SMS message transfer

5.2 Procedure for SBI-based MO SMS p. 37

5.2.1 General p. 37

The procedure for SBI-based MO SMS is showed in Figure 5.2.2-1, which is based on MO SMS procedures in clause 10.2 of TS 23.040. Compared to procedures in TS 23.040, new services are introduced in, including:

Niwmsc_SMService service provided by SMS-IWMSC.

This new service is registered in NRF, and can be invoked by service consumers.

5.2.2 Procedure for Successful Mobile Originated short message transfer p. 37

Reproduction of 3GPP TS 23.540, Fig. 5.2.2-1: Procedures for successful SBI-based SM MO message transfer

Figure 5.2.2-1: Procedures for successful SBI-based SM MO message transfer

Step 0.

The SMS-IWMSC registers with the Niwmsc_SMService service in the NRF, during the NF registration procedure.

Step 1.

The MO SM message transfer from the UE to the SMSF through the AMF follows the current procedure as defined in TS 23.040.

Step 2a.

If the SMSF knows from the local configuration that the target SMS-IWMSC does not support SBI, it shall quit the SBI-based procedure and fallback to legacy (MAP/Diameter) protocol based procedures, as defined in TS 23.040,

or the SMSF invokes the Nnrf_NFDiscovery to discover and selects the serving SMS-IWMSC with the parameters of SUPI and/or GPSI and/or location (e.g. TAIs, CGIs, etc.) and/or E.164 address of the SC.

Step 2b.

If no SMS-IWMSC could be discovered, the NRF indicates so to the SMSF (by not including any SMS-IWMSC instance in the discovery response), and the SMSF shall quit the SBI-based procedure and fallback to the legacy (MAP/Diameter) protocol based procedures, as defined in TS 23.040.

If an SMS-IWMSC is discovered and selected, the NRF returns the IP addresses or FQDNs of the serving SMS-IWMSC to provide the Niwmsc_SMService service to the SMSF.

Step 3.

The SMSF sends a Niwmsc_SMService_MoForwardSm service request to the URI of the serving SMS-IWMSC, which is obtained in step 2b. The payload body of the request shall contain the SM record to be sent, the Service Centre address, the callbackURI for MO SMS Delivery Report, the timer for waiting the MO SMS Delivery Report, and optionally contains the Access Type. If the MPS for Messaging indication from the UDM is set (enabled), the SMSF includes the MPS for Messaging indication in the request and sets the transport priority (e.g., DSCP and Message priority header) of the request to a value appropriate for MPS and handles the request with priority.

Step 4.

The MO SMS delivery procedure between the SMS-IWMSC and the SC is the same as the definition in step 4 of Figure 4.13.3.3-1 of TS 23.502. If the MPS for Messaging indication from the SMSF is set (enabled), the SMS-IWMSC sets the transport priority (e.g., DSCP and Diameter priority) of the request to a value appropriate for MPS and handles the request with priority.

Step 5.

The SMS-IWMSC sends the Niwmsc_SMService_MoForwardSm response to deliver the MO SMS delivery report to the URI of the serving SMSF, which is obtained in step 3.

Step 6.

The MO SMS delivery report procedure between the SMSF, the AMF and the UE is the same as the TS 23.502.

When no more SMS is to be sent, the procedure for the CP-ack and the SMS ack is the same as in TS 23.502.

These procedures are defined in step 6a to 6d of Figure 4.13.3.3-1 of TS 23.502.

5.2.3 Unsuccessful Mobile Originated short message transfer p. 38

Figure 5.2.3-1 depicts procedure for unsuccessful SBI-based SM MO message transfer

Reproduction of 3GPP TS 23.540, Fig. 5.2.3-1: Procedures for unsuccessful SBI-based SM MO message transfer

Figure 5.2.3-1: Procedures for unsuccessful SBI-based SM MO message transfer

Step 0-3.

The same as the procedures in step 0-3 of Figure 5.2.2-1 in clause 5.2.2

Step 4.

SMS-IWMSC sends Niwmsc_SMService_MoForwardSm response with HTTP status code for application errors as defined in Table 5.3.2-1.

Step 5.

Failure report from SMSF to UE, with the error cause code as defined in Table 5.3.2-2.

SMS-IWMSC indicates the different errors for MO SM transfer in MoForwardSm response according to the different failure scenarios which happened during MO SM transfer. The Application Errors used in Niwmsc_SMService_MoForwardSm response are defined in Table 5.3.2-1 below

Table 5.3.2-1: Application errors

Application Error	HTTP status code	Description
SMS_PAYLOAD_MISSING	400 Bad Request	The expected SMS payload content is missing.
SMS_PAYLOAD_ERROR	400 Bad Request	Error exists in the SMS payload content.
UNKNOWN_SERVICE_CENTRE_ADDRESS	403 Forbidden	The delivery of the MO short message failed because SMS-SC was unknown.
SERVICE_CENTRE_CONGESTION	403 Forbidden	The delivery of the MO short message failed because SMS-SC was in congestion.
USER_NOT_SERVICE_CENTER	403 Forbidden	The delivery of the short message failed because the user didn't belongs to the SMS-SC.
FACILITY_NOT_SUPPORTED	403 Forbidden	The delivery of the MO short message failed because of facility not supported.
INVALID_SME_ADDRESS	403 Forbidden	The delivery of the MO short message failed because the SME address is invalid.
UNREACHABLE_SMS_SC	504 Gateway Timeout	The delivery of the MO short message failed because the response is timeout.

If errors are indicated by the SMS-IWMSC, the SMSF shall send a failure report (i.e. a RP-ERROR message) to the UE, with the error cause coded as following mapping between errors indicated by SMS-IWMSC and error cause code in RP-ERROR message:

Table 5.3.2-2: Mapping between Application errors and Cause value

Return error from SMS-IWMSC	Cause value in the RP-ERROR message
The Response from SMS-IWMSC is timeout Unspecified 4xx/5xx error code	38 Network out of order
400 Bad Request with SMS_PAYLOAD_MISSING or SMS_PAYLOAD_ERROR	99 Information element non-existent or not implemented
403 Forbidden with FACILITY_NOT_SUPPORTED	69 Requested facility not implemented
403 Forbidden with UNKNOWN_SERVICE_CENTRE_ADDRESS	1 Unassigned number
403 Forbidden with SERVICE_CENTRE_CONGESTION	42 Congestion
403 Forbidden with USER_NOT_SERVICE_CENTER	28 Unidentified subscriber
403 Forbidden with INVALID_SME_ADDRESS	21 Short message transfer rejected

5.2.4 MSISDN-less MO SMS message transfer p. 39

The procedure for SBI-based MSISDN-less MO SMS message transfer is depicted in Figure 5.2.4-1,

Reproduction of 3GPP TS 23.540, Fig. 5.2.4-1: Procedures for MSISDN-less MO SMS message transfer

Figure 5.2.4-1: Procedures for MSISDN-less MO SMS message transfer

Step 0.

NEF registers Nnef_SMService_MoForwardSm service and supporting long/short code ranges in NRF, during the NF registration procedure.

Step 1.

MO SMS transmit from UE to SMS-SC, as already defined in clause 5.2.2.

Step 2a-2b.

SMS-SC provides destination SME address (long/short code of the AF) to NRF for NEF selection, and chooses Nnef_SMService_MoForwardSm service for MSISDN-less MO SMS submit.

Step 3.

SMS-SC forwards MO SM to NEF, by invoking Nnef_SMService_MoForwardSm service.

Step 4-5.

Nudm_SDM_Get and response between NEF and UDM, which refers to Step 3-Step 4 of Figure 4.13.7.2-1 in TS 23.502.

Step 6.

The NEF provides a Nnef_MSISDN-less_MO_SMS Notify, which refers to Step 5 of Figure 4.13.7.2-1 in TS 23.502.

Step 7.

NEF sends Nnef_SMService_MoForwardSm response to SMS-SC, carrying a success or failure delivery indication to SMS-SC.

Step 8.

SMS-SC indicates success/failure back to UE using existing SBI-based SMS delivery report defined in clause 6.2.2.