A simpler TSN? Traffic Scheduling vs. Preemption.

This paper extends research on TSN enablement for industrial automation, comparing the time-aware traffic shaping with the traffic (frame) preemption. Time-aware traffic shaping combined with tightly synchronized end devices enables data exchange cycles with μs granularity and nanosecond jitter, but requires system-wide scheduling for all networked devices, which can be difficult in multi-hop networks. Frame preemption does not require scheduling, and is anticipated to simplify network configuration while providing similar guarantees in latency and jitter for high priority traffic. However, it is not yet clear just how deterministic frame preemption is in comparison with time-aware traffic shaping. This manuscript compares the two mechanisms in a real heavy-loaded TSN network.