6GSMART-EZ: Integration of 5G and Time-Sensitive Networking

Time-sensitive networking, a set of IEEE 802.1 standards to grant Quality of Service in Ethernet networks, is emerging as one of the main technologies in Industry 4.0 environments because of its characteristics (bounded low latency, high reliability, time synchronization, resource management…). Furthermore, the need to provide strict quality-of-service guarantees in industrial automation scenarios and the evolution towards smart factories, together with the needs for mobility, reduction of wires, and flexibility in the factory, motivate the integration of TSN with wireless technologies like 5G, which brings the required flexibility without compromising the advantages of TSN.

Among the existing 5G service categories (eMMB, mMTC, URLLC), Ultra-Reliable Low Latency Communications focuses on increasing reliability and lowering latencies of data transmissions, making it suitable for industrial communications and a perfect candidate for integration with TSN.

5G-TSN integration

Starting from Release 16, 3GPP standardized the architecture of the 5G-TSN integration. The 5G system is considered a TSN bridge in this new architecture. It must implement its typical functionalities (such as configuring scheduling in its ports and discovering and reporting its neighbours to the control plane, to name a couple).

A typical 5G-TSN scenario would look like the following diagram:

• Talker and Listener are TSN endpoints, sending and receiving traffic.
• CUC and CNC compose the TSN control plane. CUC is in charge of collecting stream requirements from Talker/Listener and CNC computes a scheduling that considers the network topology and the information provided by the CUC.
• Device-Side TSN Translator (DS-TT) and Network-Side TSN Translator (NW-TT) are located at the edges of the 5G-TSN bridge, next to the UE and the UPF. They are designed to apply the scheduling generated by the CNC, performing link layer connectivity discovery (to report its neighbours to CNC) and turning the 5G-TSN bridge into a PTP boundary clock or a transparent clock to maintain time synchronization in the whole network. They are responsible for adapting the 5G and TSN data planes.
• The TSN AF network function is added as a module to integrate the 5G and TSN control planes. From the CNC point of view, the 5G system appears to be a common TSN switch. It reports the 5G-TSN bridge neighbours, receives the scheduling from CNC, applies it in DS-TT and NW-TT, and performs QoS mapping by choosing an adequate 5QI for each TSN traffic class.

The 5G-TSN testbed in 6GSMART-EZ

Within the 6GSMART project, UPC and i2CAT have built a 5G-TSN integration testbed using 5G and TSN software and hardware. The testbed has been developed and evaluated with synthetic and real traffic sources and a 5G emulator at the UPC premises. It was later integrated at i2CAT laboratories with a 5G cell and a robotic arm (connected to the listener) to emulate a real industrial scenario. The testbed is shown in the following figure, following the previous scenario:

• Open5GS is being used as the 5G core network. The UE is being implemented using a Quectel RM500Q-GL, while gNB is built with an Amarisoft server and a AW2S PANTHER 4T4R
• Relyum TSN switches are located in both TSN isles.
• DS-TT and NW-TT are built using TSN NICs from Relyum.
• CUC/CNC and TSN AF have been developed within the 6GSMART-EZ project, and its Github repositories can be found here and here.
• The talker is built with a common PC and a TSN NIC, while a robotic arm (Niryo Ned 2) acts as a Listener receiving instructions from the Talker.

The evaluation of the testbed has demonstrated the traffic isolation and QoS capacities of both TSN and 5G, reaching the extreme KPIs expected.

More details about the testbed and the preliminary evaluation results can be found in the following publications:

A. Agustí-Torra, M. Ferré-Mancebo, D. Rincón-Rivera, C. Cervelló-Pastor and S. Sallent-Ribes, “Building a 5G-TSN Testbed: Architecture and Challenges,” 2024 24th International Conference on Transparent Optical Networks (ICTON), Bari, Italy, 2024, pp. 1-4

A. Agustí-Torra, M. Ferré-Mancebo and D. Rincón-Rivera, “Emulating Integrated 5G-TSN Scenarios,” 2024 15th International Conference on Network of the Future (NoF), Castelldefels, Spain, 2024, pp. 96-100

Author: Marc Ferré Mancebo, researcher at the Design and Evaluation of Broadband Networks and Services (BAMPLA) research group of the Universitat Politècnica de Catalunya (UPC)