3GPP 24.501 v20.0.0 — the document's own text

6.3.2.6 Abnormal cases in the UE

Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).

The following abnormal cases can be identified:

PDU session inactive for the received PDU session ID.

If the PDU session ID in the PDU SESSION MODIFICATION COMMAND message belongs to any PDU session in state PDU SESSION INACTIVE in the UE, the UE shall set the 5GSM cause IE to #43 "Invalid PDU session identity" in the 5GSM STATUS message, and set the PDU session ID to the received PDU session ID in the UL NAS TRANSPORT message as specified in clause 5.4.5.

Collision of network-requested PDU session modification procedure and UE-requested PDU session modification procedure.

If the UE receives a PDU SESSION MODIFICATION COMMAND message during the UE-requested PDU session modification procedure, the PTI IE of the PDU SESSION MODIFICATION COMMAND message is set to "No procedure transaction identity assigned", and the PDU session indicated in the PDU SESSION MODIFICATION COMMAND message is the PDU session that the UE had requested to modify, the UE shall abort internally the UE-requested PDU session modification procedure, enter the state PDU SESSION ACTIVE and proceed with the network-requested PDU session modification procedure.

A semantic error in QoS operations or a sematic error in packet filters is detected in a PDU SESSION MODIFICATION COMMAND message that contains other optional information elements.

If the UE diagnoses a semantic error in QoS operations or a semantic error in packet filters in the PDU SESSION MODIFICATION COMMAND, as specified in clause 6.3.2.4, and the message contains other optional information elements, the UE shall discard the other optional information elements and shall send the PDU SESSION MODIFICATION REJECT message as specified in clause 6.3.2.4.