This annex defines the procedures for 5GS integration with TSN fully-centralized model as defined in IEEE Std 802.1Qcc-2018 , it includes 5GS Bridge information reporting and 5GS Bridge configuration.
Identities of 5GS Bridge and UPF/NW-TT ports are pre-configured on the UPF based on deployment. The SMF requests the UPF/NW-TT to measure and report the clock drift between the TSN GM time and 5GS GM time for one or more TSN working domains.
PDU Session Establishment as defined clause 188.8.131.52.1 is used to establish a PDU Session serving for TSC.
During this procedure, the SMF selects a UPF, which supports functions as defined in clause 5.28.1 of TS 23.501, for the PDU Session.
During this procedure, the SMF receives the UE-DS-TT residence time, DS-TT MAC address for this PDU Session and port management capabilities from the DS-TT/UE in PDU Session Establishment request, and receives the allocated port number for DS-TT Ethernet port and user-plane Node ID in N4 Session Establishment Response message. The UPF allocates the port number for DS-TT, user-plane Node ID after receiving N4 Session Establishment Request message.
The SMF sends the information received in step 1 to the TSN AF via PCF to establish/modify the 5GS Bridge. The Npcf_PolicyAuthorization_Notify message in step 2b is delivered via the pre-configured AF session as described in clause 184.108.40.206. The TSN AF stores the binding relationship between 5GS user-plane Node ID, MAC address of the DS-TT Ethernet port and also updates 5GS bridge delay as defined in clause 5.27.5 of TS 23.501 for future configuration. The TSN AF requests creation of a new AF session associated with the MAC address of the DS-TT Ethernet port using the Npcf_PolicyAuthorization_Create operation (step 2c) and subscribes for TSN events over the newly created AF session using the Npcf_PolicyAuthorization_Subscribe operation (step 2d).
Using the 5GS user-plane Node ID received in step 2b the TSN AF subscribes with the NW-TT for receiving user plane node management information changes for the 5GS bridge indicated by the 5GS user-plane Node ID as described in clause 220.127.116.11 of TS 23.501.
After receiving a User plane node Management Information Container (UMIC) containing the NW-TT port numbers, the TSN AF subscribes with the NW-TT for receiving NW-TT port management information changes for the NW-TT port indicated by each of the NW-TT port numbers as described in clause 18.104.22.168 of TS 23.501.
The TSN AF can use any PDU Session to subscribe with the NW-TT for bridge or port management information notifications. Similarly, the UPF can use any PDU Session to send bridge or port management information notifications.
If supported according to the port management capabilities received from DS-TT, TSN AF retrieves txPropagationDelay and Traffic Class table from DS-TT. TSN AF also retrieves txPropagationDelay and Traffic Class table from NW-TT.
CNC provides per-stream filtering and policing parameters according to clause 22.214.171.124 of IEEE Std 802.1Q  to AF and the AF uses them to derive TSN QoS information and related flow information. The CNC provides the forwarding rule to AF according to clause 8.8.1 of IEEE Std 802.1Q . The TSN AF uses this information to identify the DS-TT MAC address of corresponding PDU session.
The AF determines if the stream is UE-UE TSC and divides the stream into UL and DL streams for PDU Sessions corresponding to ingress DS-TT Ethernet port and egress DS-TT port(s) as specified in clause 5.28.2 of TS 23.501, and separately triggers following procedures for the UL and DL streams.
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 information and TSC Assistance Container for one or more TSN streams and sends them to the PCF. The TSN AF also provides Service Data Flow Filter containing Flow description also includes Ethernet Packet Filters.
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 message.
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 Ethernet Packet Filters, the 5GS QoS profile along with TSC Assistance 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.
Upon reception of the TSC Assistance Container, the SMF determine the TSCAI for QoS flow and sends the TSCAI along with the QoS profile to the NG RAN.
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 QoS 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 information provided by the AF to PCC rules as described in clause 5.28.4 in TS 23.501. The PCF includes the TSC Assistance Container received from the AF with the PCC rules and forwards it to the SMF. The PCF transparently transports the received Port Management information Container and related port number to SMF via Npcf_SMPolicyControl_UpdateNotify message.
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. SMF provides the Ethernet Packet Filters as part of the N4 Packet Detection rule to the UPF/NW-TT.
If the UPF sends a Clock Drift Report to the SMF as described in clause 5.27.2 in TS 23.501, the SMF adjusts the Burst Arrival Time, Periodicity and Survival Time (if present) from a TSN grandmaster clock to the 5G clock and sends the updated TSCAI to NG-RAN.
The UPF/NW-TT receives the Announce message via User -plane from DS-TT connectivity established using PDU session, or via NW-TT port over N6.
As Announce message is a periodic message, after step 3, the UPF/NW-TT will receive Announce messages regularly.
If the BMCA procedure in NW-TT determines to use Announce message from the external grandmaster PTP instance, the UPF/NW-TT regenerates the Announce message based on the received Announce message for each Master PTP port on the NW-TT and DS-TT(s) port for this PTP domain. The NW-TT/UPF forwards the regenerated Announce messages to the PDU session(s) related to the Master PTP ports on the DS-TT(s).
If the TSN AF or TSCTSF has subscribed for notifications for the PTP port state changes, the UPF/NW-TT reports any changes to the PTP port states to the TSN AF or TSCTSF via UMIC (for DS-TT ports) or PMIC (for NW-TT ports).
Based on the notification for the PTP port state changes, the TSN AF or TSCTSF may request appropriate QoS treatment and PDU Session modification may then be triggered to modify the QoS Flow carrying the gPTP messages over user plane in order to be compliant with the IEEE Std 802.1AS  delay recommendation for carrying gPTP messages as in clause 126.96.36.199 of TS 23.501.
This annex applies when the SMF+PGW-C is enhanced to support GERAN/UTRAN access via Gn/Gp interface as specified in Annex L of TS 23.501.
SMF+PGW-C is selected by the SGSN using existing mechanism as specified in Annex A of TS 23.060.
When a SMF+PGW-C is used for GERAN/UTRAN access, at PDP context activation, the SMF+PGW-C allocates a PDU Session ID (in the network range) and uses this PDU Session ID over SBI interface (e.g. N7).
The following procedures from TS 23.060 are not supported when SMF+PGW-C is used for GERAN/UTRAN access:
When SMF+PGW-C is used for GERAN/UTRAN access and interacts with PCF, the SMF+PGW-C uses SM policy association procedures as specified in clause 4.11.0a.2 with the following modification:
The SMF+PGW-C performs mapping of QoS parameters as follows:
The SMF+PGW-C maps the Release 99 QoS parameters received from Gn/Gp interface to EPS QoS parameters as specified in Annex E of TS 23.401, which is then used to derive QoS parameters over N7 interface as specified in clause 4.11.0a.2.
the SMF+PGW-C uses QoS parameters over N7 interface to derive EPS QoS parameters as specified in clause 4.11.0a.2, which is then mapped to Release 99 QoS parameters for Gn/Gp interface as specified in Annex E of TS 23.401.
For SM Policy Association Establishment Procedure, the SMF+PGW-C invokes Npcf_SMPolicyControl_Create Service operation taking input from the information elements received in Create PDP Context Request message (specified in TS 23.060), including mapping of QoS parameters as mentioned above as well as GERAN/UTRAN location management related information.
For SM Policy Association Modification procedure initiated by the SMF+PGW-C, the SMF+PGW-C invokes Npcf_SMPolicyControl_Update Service operation taking input from the information elements received in Update PDP Context Request message (specified in TS 23.060), including mapping of QoS parameters as mentioned above, as well as GERAN/UTRAN location management related information.
For SM Policy Association Modification procedure initiated by the PCF, the SMF+PGW-C may receive PCC Rules and PDU Session Policy Information. The SMF+PGW-C performs mapping of QoS parameters as mentioned above.
For SM Policy Association Termination procedure, the SMF+PGW-C invokes Npcf_SMPolicyControl_Delete service operation (including GERAN/UTRAN location management related information) when receiving Delete PDP Context Request message (specified in TS 23.060).
Even though N7 supports Ethernet PDU Session Type, as Ethernet PDN Type is not supported in GERAN/UTRAN, it is assumed that if the UE moves from E-UTRAN to GERAN/UTRAN, Ethernet PDN connections are released and thus no information related with Ethernet PDU Session Type shall be exchanged over N7 when a UE is served by GERAN/UTRAN.
Even though GERAN/UTRAN specifications foresee other alternatives, the Bearer Binding is performed by the SMF+PGW-C acting as a PGW.
Access Network Information reporting with a granularity of GERAN/UTRAN cell is supported over N7 and N5.
When the UE moves between E-UTRAN and GERAN/UTRAN, the SMF+PGW-C may invoke SM Policy Association Modification procedure based on the Policy Control Request Triggers as specified in TS 23.503.