A Two-Stage Routing Algorithm for Time-Triggered Flows in Time Sensitive Networks

Abstract

In modem factory communication, the traditional field bus type technology has gradually given way to Ethemetbased technology (e.g., industrial Ethernet, traditional Ethernet). Therefore, the Ethernet-based Time Sensitive Network (TSN) specified by the IEEE 802.1 working group quickly became the first choice for industrial real-time networks. TSN makes it possible to achieve deterministic real-time communication over Ethemet. It requires that the transmission of time-triggered (TT) data flows in the network be transmitted according to a pre-planned schedule. However, if TT flows’ routing paths are not carefully chosen (for example, adopting the shortest path algorithm) before their scheduling, the network capacity will be limited. This is because some links saturate faster than other links, preventing more TT flows from being added into the network. Such load imbalance also leaves less link capacity for the secondary rate constrained (RC) flows, resulting in higher latency. In this paper, we propose a twostage load-balancing routing heuristic algorithm for TT flows to avoid congested links as much as possible, and also reap the benefit from the shortest path algorithm. It can achieve low end-to-end delay and also ensure a high degree of load balance.