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.
Step 0.
SMS-IWMSC registers Niwmsc_SMService service in the NRF, during the NF registration procedure.
Step 1.
MO SM message transfer from UE to SMSF through AMF follows the current procedure as defined in
TS 23.040
Step 2a.
If SMSF knows from 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 SMSF invokes the
Nnrf_NFDiscovery to discover and select 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 SMSF (by not including any SMS-IWMSC instance in the discovery response), and SMSF shall quit the SBI-based procedure and fallback to legacy (MAP/Diameter) protocol based procedures, as defined in
TS 23.040.
If a SMS-IWMSC is discovered and selected, NRF returns the IP addresses or FQDNs of the serving SMS-IWMSC to provide
Niwmsc_SMService service to SMSF.
Step 3.
SMSF sends a Niwmsc_SMService_MoForwardSm service request to the URI of 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.
Step 4.
Step 5.
SMS-IWMSC sends Niwmsc_SMService_MoForwardSm response to deliver the MO SMS delivery report to the URI of serving SMSF, which is obtained in step 3
Step 6.
MO SMS delivery report procedure between SMSF, AMF and UE is the same as the
TS 23.502.
When no more SMS is to be sent, the procedure for CP-ack and SMS ack is the same as the
TS 23.502.
These procedures are defined in step 6a to 6d of
Figure 4.13.3.3-1 of
TS 23.502.
Figure 5.2.3-1 depicts procedure for unsuccessful SBI-based SM MO message transfer
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
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:
The procedure for SBI-based MSISDN-less MO SMS message transfer is depicted in
Figure 5.2.4-1,
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.
Step 6.
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.