E.2 EPS aspects when connected to the IM CN subsystem

24.3413GPPRelease 18Stage 3Support of SMS over IP networksTS

E.2.1 Procedures at the UE

E.2.1.1 Smart Congestion Mitigation

The following information is provided to the non-access stratum layer:

– MO-SMSoIP-attempt-started;

– MO-SMSoIP-attempt-ended;

– MT-SMSoIP-attempt-started; and

– MT-SMSoIP-attempt-ended.

Upon request from the user to submit an originating SM over IP as described in clause 5.3.1 and no other originating SM over IP as described in clause 5.3.1 exists, the UE sends the MO-SMSoIP-attempt-started indication to the non-access stratum and continue with SM over IP submission as described in clause 5.3.1.

When a terminating SM over IP submission is started and no other terminating SM over IP submission as described in clause 5.3.2 exists, the UE sends the MT-SMSoIP-attempt-started indication to the non-access stratum.

When an originating SM over IP submission is completed and no other originating SM over IP as described in clause 5.3.1 exists, the UE sends the MO-SMSoIP-attempt-ended indication to the non-access stratum.

When a terminating SM over IP submission is started and no other terminating SM over IP submission as described in clause 5.3.2 exists, the UE sends the MT-SMSoIP-attempt-started indication to the non-access stratum.

NOTE: If the UE supports other 3GPP specific mechanisms for communicating with the non-access stratum protocol implementation, e.g. DHCP discovery via PCO, then the UE is expected to support the transfer of information elements needed for the smart congestion mitigation enforcement.