Link State Based Routing and Scheduling Co-Design of Time-Triggered Traffic in Time-Sensitive Networking

Driven by the demand for high reliability and low latency applications, the IEEE 802.1 TSN working group proposed Time-Sensitive Networking (TSN) to support time-triggered (TT) traffic for real-time applications and meet compatibility and interoperability requirements. However, when solving the TT traffic scheduling problem in TSN, direct routing using the shortest path or co-design routing for traffic scheduling does not consider the transmission capacity differences caused by different link states, which can result in increased link conflicts and poor scheduling results. This paper takes into account the impact of different link states on routing and scheduling to solve the scheduling problem and minimize the average end-to-end delay of traffic. Specifically, the joint design problem is split into two sub-problems: routing and traffic scheduling. Candidate paths are selected based on delay during routing and added one-by-one using a greedy strategy. When solving the scheduling problem, Optimization Modulo Theory (OMT) is used to model the problem, and Z3 solver is utilized to solve it. Numerical simulations demonstrate that compared to the benchmark methods, the proposed algorithm can effectively reduce the average end-to-end delay of traffic, improve the success rate of scheduling, and optimize the link load distribution.