23.2043GPPRelease 16Stage 2Support of Short Message Service (SMS) over generic 3GPP Internet Protocol (IP) accessTS
If the HLR/HSS has recorded the MWD with a failure reason that the message failed to be sent by IP‑SM‑GW due to the memory capacity of the UE is exceeded, once the HLR/HSS receives a message from any of the domain indicating that the memory capacity of the UE is available again, e.g. form the IMS, PS or CS domain, the HLR/HSS initiates a Alert service centre procedure to request the SMSC to re-send the stored message.
The following figure only shows an example where the HLR/HSS invokes the Alert service centre procedure when the memory capacity available message is received from IMS.
Figure 6.6: Alert service centre procedure when memory capacity is available
1) If SM termination attempts (via IP-SM-GW) failed because the UE’s Memory Capacity Exceeded, the message to be transferred to IP Based UE is queued in the SMS-SC.
2) UE sends a message to IP-SM-GW indicating that the UE has memory available to receive one or more Short Messages.
3) IP-SM-GW notifies the HLR/HSS of memory being available in the UE.
4) If the HLR/HSS receives the indication that the UE has memory available to receive one or more Short Messages, it initiates a Alert service centre procedure with the SC address and the MSIsdn‑Alert to SMS‑IWMSC as described in TS 23.040 .
5) The SMS‑IWMSC forwards the Alert service centre message to the SMS-SC whose address was provided by the HLR/HSS in step 4.