Industry automation systems are using the PROFINET protocol to allow multi-vendor implementation. From a mobile network technology perspective, PROFINET requires communication to happen on Layer 2 instead of traditional Layer 3. For some time, there has been available VLAN technology to provide a Layer 2 tunnel between User Plane Function (UPF) and UE. Setting up a tunnel is additional work and more importantly, every vendor has different requirements and procedures for the VLAN tunnels. Using PROFINET over VLAN is not a scalable solution.
To solve this problem, 3GPP has a standardized Ethernet Packet Data Unit (PDU). Ethernet PDU provides native Layer 2 connectivity between UPF, and UE as shown in the picture below.
5G SA network using Ethernet PDU can deliver Precision Time Protocol (PTP) messages over the network and deliver TSN feature. Having time synchronization is a mandatory feature in automation systems, in control loops we need to have precise knowledge of when measurements have been done and synchronize control signals to valves, motors etc.
Cumucore has been working with the ABB automation division to build a real-life off-the-shelf solution. In April 2023, we had a breakthrough to deliver synchronization signals over the network. See the network diagram below.
Work will continue to improve network accuracy using new Release 17 Ultra Reliable Low Latency Communications (URLLC) features and UE capabilities.