Multipath Routing of Mixed-Critical Traffic in Time Sensitive Networks

Abstract

Distributed embedded systems for safety-critical applications demand reliable communication with real-time characteristics. Switched Ethernet-based network is a practical and scalable solution that allows high-reliability level through path redundancy. The Time-Sensitive Networking (TSN) standard is being developed to support real-time communication which supports a deterministic and low latency communication for safety-critical control applications, namely, Time-Triggered (TT) traffic class. In addition, a bounded-latency traffic class, namely, Audio Video Bridging (AVB) class is introduced. In this paper, we propose a multipath routing technique which tackles both TT and AVB traffic simultaneously. The proposed approach investigates satisfying path redundancy requirements for each message while the imposed interference from TT traffic on AVB traffic is minimized. The considered routing problem is formalized as an Integer Linear Programming (ILP) optimization problem. The Worst Case end-to-end Delay (WCD) is the optimization objective. 50 test cases of various network size and number of messages are solved to evaluate the performance, i.e., interference reduction, and the scalability of the proposed technique. Results demonstrate WCD reduction up to 90% comparing to the typical routing approach that determines TT and AVB routing in separate steps.