Analyzing and modeling the latency and jitter behavior of mixed industrial TSN and DetNet networks

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.