3GPP 24.501 v20.0.0 — the document's own text
5.3.11 Handling of S-NSSAI based congestion control
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
The AMF may detect and start performing S-NSSAI based congestion control when one or more S-NSSAI congestion criteria as specified in 3GPP TS 23.501 [8] are met. If the UE does not provide a DNN for a non-emergency PDU session, then the AMF uses the selected DNN or the DNN associated with the PDU session corresponding to the 5GSM procedure. If the UE does not provide an S-NSSAI for a non-emergency PDU session, then the AMF uses the selected S-NSSAI or the S-NSSAI associated with the PDU session corresponding to the 5GSM procedure.
The AMF may detect and start performing S-NSSAI based congestion control when the UE that does not support S-NSSAI location validity information requests a PDU session establishment for an S-NSSAI limited by NS-AoS and the UE is outside the NS-AoS of the S-NSSAI.
When S-NSSAI based congestion control is activated at the AMF, the AMF performs the congestion control as specified in clause 5.4.5 and the UE performs the congestion control as specified in clause 5.4.5 and clause 6.2.8.