Time-sensitive Networking

TSN enhances standard Ethernet by providing deterministic, low-latency, and low-jitter data transmission capabilities. While Ethernet inherently operates on a best-effort, first-come, first-served basis, TSN guarantees that data is delivered with precise timing. To make this possible, TSN leverages several IEEE 802.1 standards including 802.1Qbv Time-aware Shaper and 802.1AS time synchronization. These characteristics make TSN invaluable in domains like industrial automation, where precise timing is critical.

• Elevated Performance: TSN offers high-speed networking, transmission of large data volumes, highly accurate motion control, and low latency, all of which enhance the performance of your network.
• Exceptional Flexibility: TSN is based on standard Ethernet, meaning it supports a broad range of networking devices. Additionally, TSN provides the possibility of adding more advanced applications to your Ethernet network.
• Real-time Precision: TSN can prioritize network traffic to enable real-time communication and ensure that time-critical data is always delivered to the right place at the right time.
• Enhanced Security: TSN can help enhance network security by scheduling time-sensitive data to avoid the influx of non-authorized data.

The convergence of IT and OT systems into a unified network is essential for achieving more streamlined production processes and higher operational efficiency, but integrating these wildly different, isolated systems into a single network is no easy task. However, a unified network offers several unique benefits:

• Standardized Communication: Using a single industry standard for communication simplifies interactions, ensures compatibility between various systems, and opens up the possibility of adopting advanced applications, such as AI.
• Better Accessibility: A unified network using one language reduces the need to get familiar with proprietary protocols from different vendors, making it easier for staff to operate and maintain the network.
• Cost Efficiency: TSN simplifies device and protocol requirements to streamline the network infrastructure, which reduces maintenance and operational costs.

Time-sensitive Networking (TSN) is a collection of IEEE standards designed to bring deterministic behavior to standard Ethernet networks. The key standards include:

• IEEE 802.1AS – Time Synchronization: Provides precise clock synchronization across network devices. It ensures that all nodes share a common time base, which is essential for scheduled traffic and real-time applications.
• IEEE 802.1Qbv – Time-aware Scheduling: Introduces time-based scheduling by assigning specific time slots for transmitting different traffic classes. This eliminates collisions and guarantees predictable latency.
• IEEE 802.1Qbu / IEEE 802.3br – Frame Preemption: Allows high-priority frames to interrupt ongoing low-priority transmissions. This minimizes jitter and ensures timely delivery of critical data.
• IEEE 802.1CB – Frame Replication and Elimination for Reliability: Enables redundant transmission of critical data across multiple paths. At the destination, duplicate frames are identified and removed, enhancing network reliability.
• IEEE 802.1Qci – Per-stream Filtering and Policing: Provides traffic control and filtering on a per-stream basis. It enforces security and performance policies by limiting traffic bursts and blocking unauthorized flows.

Time-aware Shaper (TAS), defined in IEEE 802.1Qbv, is a scheduling mechanism that enables network devices to transmit packets at specific times based on a predefined schedule. Using a Gate Control List (GCL), TAS opens and closes transmission gates for different traffic queues during user-defined time windows, ensuring that time-critical or high-priority traffic is sent exactly when needed.​

TAS plays a crucial role in TSN by enabling deterministic behavior over Ethernet. It allows various types of traffic—such as control commands, video streams, and best-effort data—to coexist on the same network without interfering with each other. This is especially important for industrial automation, robotics, and automotive applications where communication latency must be predictable and controllable. ​

TSN does not replace existing industrial protocols, but rather enhances them by providing a reliable, low-latency, and deterministic Ethernet backbone. Protocols like OPC UA and PROFINET can operate over TSN-enabled networks, benefiting from features such as time synchronization (IEEE 802.1AS), time-aware scheduling (IEEE 802.1Qbv), and redundancy (IEEE 802.1CB).​

For example, OPC UA over TSN is a key industry initiative where the OPC UA Pub/Sub model is combined with TSN to ensure timely and predictable message delivery—ideal for edge computing and factory automation scenarios. Similarly, PROFINET is being extended to support TSN, improving its real-time performance and enabling better integration between OT and IT systems.