4 General

24.5393GPP5G System (5GS)Network to TSN translator (TT) protocol aspectsRelease 18Stage 3TS

For time sensitive communication (TSC), a 5G system (5GS) can act as a user plane node of an external network or a 5GS can be independently used to enable TSC.

The device-side TSN translator (DS-TT) is deployed at the UE-side edge and the network-side TSN translator (NW-TT) is deployed at the network-side edge (see 3GPP TS 23.501 [2]).

When integrated with IEEE TSN network, the TSN application function (TSN AF) is deployed to exchange user plane node information (i.e. TSN bridge information) with the centralized network configuration (CNC) as defined in IEEE Std 802.1Qcc-2018 [9]. The user plane node information includes port management information and user plane node management information. Port management information is related to ports located in the DS-TT and NW-TT. User plane node management information is related to the NW-TT.

In order to support user plane node information exchange between TSN AF and CNC, the DS-TT, NW-TT, and TSN AF support procedures for port management and user plane node management. Clause 5 describes details of the elementary procedures between TSN AF and DS-TT for port management. Clause 6 describes details of the elementary procedures between TSN AF and NW-TT for port management (clause 6.2) and user plane node management (clause 6.3). The operations supported by the TSN AF for port management and user plane node management are listed in 3GPP TS 23.501 [2] table 5.28.3.1-1 and table 5.28.3.1-2.

A 5GS supports AF-requested time synchronization services. For this purpose, an NEF in the 5GS exposes 5GS capabilities to support the services as described in 3GPP TS 23.501 [2] and the Time Sensitive Communication and Time Synchronization Function (TSCTSF) manages the user plane node and ports (either Ethernet ports or PTP ports) in the DS-TT and NW-TT for time synchronization. Therefore, the DS-TT, NW-TT, and TSCTSF support procedures for port management and user plane node management. Clause 5 describes details of the elementary procedures between the TSCTSF and DS-TT for port management for time synchronization. Clause 6 describes details of the elementary procedures between the TSCTSF and NW-TT for port management (clause 6.2) and user plane node management (clause 6.3) for time synchronization. The operations supported by the TSCTSF for port management and user plane node management are listed in 3GPP TS 23.501 [2] table 5.28.3.1-1 and table 5.28.3.1-2.

NOTE: What is applicable for a TSN AF in this technical specification can be applied for a TSCTSF unless specified otherwise.