CNC provides TSN information according to IEEE 802.1Q  clause 220.127.116.11 to AF to derive TSN QoS information and related flow information. The CNC provide the forwarding rule to AF according to IEEE 802.1Q . The TSN AF uses this information to identify the DS-TT MAC address of corresponding PDU session.
The AF determines the MAC address of a PDU Session based on the previous stored associations, then triggers an AF request procedure. The AF request includes the DS-TT MAC address of the PDU session.
Based on the information received from the CNC, 5GS bridge delay information and the UE-DS-TT residence time, the TSN AF determines the TSN QoS parameters and TSN QoS container for TSN streams and sends them to the PCF.
When PCF receives the AF request, the PCF finds the correct SMF based on the DS-TT MAC address of the PDU session and notifies the SMF via Npcf_SMPolicyControl_UpdateNotify
After mapping the received TSN QoS parameters for TSN streams to 5GS QoS, the PCF triggers Npcf_SMPolicyControl_UpdateNotify
message to update the PCC rule to the SMF. The PCC rule includes the TSN QoS container.
SMF may trigger the PDU Session Modification procedure to establish/modify a QoS Flow to transfer the TSN streams. During this procedure, the SMF provides the information received in PCC rules to the UPF via N4 Session Modification procedure. The SMF calculates the TSCAI and sends it to NG-RAN.
Upon reception of TSN QoS container, the SMF determine the TSCAI for QoS flow and sends the TSCAI along with the QoS profile to the NG RAN.
If needed, the TSN CP provides additional information (e.g. the gate control list as defined in IEEE 802.1Qbv ) to the TSN AF.
The AF determines the MAC address of a PDU Session for the configured port based on the previous stored associations, this is used to deliver the Port Management information to the correct SMF that manages the port via PCF. The AF triggers an AF request procedure. The AF request includes the DS-TT MAC address (i.e. the MAC address of the PDU Session), TSN AF Parameters, Port Management information Container and the related port number as defined in clause 5.28.3 of TS 23.501
. The port number is used by SMF to decide whether the configured port is in DS-TT or NW-TT.
The PCF determines the SMF based on the MAC address received in the AF request, the PCF maps the TSN QoS parameters provided by the AF to PCC rules as described in clause 5.28.4 in TS 23.501
. The PCF associates the TSN AF QoS container as received from the AF with the PCC rules and forwards the TSN AF QoS container along with the PCC rules to the SMF. The PCF transparently transports the received Port Management information Container and related port number to SMF via Npcf_SMPolicyControl_UpdateNotify
If the SMF decides the port is on DS-TT based on the received port number, the SMF transports the received Port Management information Container to the UE/DS-TT in PDU Session Modification Request message.
If the SMF decides the port is on NW-TT based on the received port number, the SMF transports the received Port Management information Container to the UPF/NW-TT in N4 Session Modification Request message.
If the UPF sends a Clock Drift Report to the SMF (after detecting drift of offset or change in the cumulative rateRatio between TSN GM time and 5G GM time), the SMF adjusts the Burst Arrival Time and Periodicity from a TSN clock to the 5G clock and sends the updated TSCAI to NG-RAN.