Real-Time Traffic Guarantees in Heterogeneous Time-sensitive Networks

Time-Sensitive Networks (TSN) enhance standard IEEE 802.1Q Ethernet devices with real-time and time-aware capabilities. The forwarding of time-critical frames is done according to a so-called Gate Control List (GCL) schedule via the timed-gate mechanism introduced in IEEE 802.1Qbv. Most TSN scheduling mechanisms impose that all devices in the network must have the TSN capabilities related to scheduled gates and time synchronization. However, this is often an unrealistic assumption since many distributed applications use heterogeneous TSN networks with legacy or off-the-shelf end systems that are unscheduled and/or unsynchronized. This paper proposes a novel, more flexible TSN scheduling algorithm that intertwines a worst-case delay analysis within the scheduling synthesis step. Through this, we leverage the solution's optimality to support heterogeneous TSN networks featuring unscheduled and/or unsynchronized end-systems while still guaranteeing the timeliness of critical communication. We evaluate the performance of our approach using both synthetic and real-world use cases, comparing it with existing TSN scheduling mechanisms. Furthermore, we use OMNET++ to validate the generated GCL schedules.