Analyzing and modeling the latency and jitter behavior of mixed industrial TSN and DetNet networks
Lukas Wüsteney, David Hellmanns, Markus A. Schramm, Lukas Osswald, René Hummen, Michael Menth, Tobias Heer
Abstract
Today, industrial real-time communication is commonly designed based on two key principles to satisfy the challenging Quality of Service (QoS) requirements of industrial applications: a) local communication and b) purpose-built networks. IEEE Time-Sensitive Networking (TSN) and IETF Deterministic Networking (DetNet) promise to lift these two limitations. This facilitates the transformation of previously loosely integrated automation network parts from isolated, purpose-built real-time networks to more tightly integrated, open, multi-purpose networks of networks. With TSN and DetNet, each of these interconnected networks, e.g., machine or backbone networks, can and will be fined-tuned for optimal performance regarding the different real-time applications located inside them. The resulting patchwork of DetNet-connected TSN networks, however, creates a challenge for cross-network real-time communication: predicting QoS properties, such as the end-to-end latency. To address this challenge, we propose a model that allows calculating best-case and worst-case latencies for time-critical communication across different DetNet-connected TSN networks. This enables validating end-to-end communication requirements in open, multi-purpose industrial networks. Our evaluation with real industrial hardware shows the applicability of our proposed model.