Node Bundle Scheduling: An Ultra-low Latency Traffic Scheduling Algorithm for TAS-Based Time-Sensitive Networks

Time Aware Shaper (TAS) and the corresponding traffic scheduling algorithms jointly ensure low-latency and low-jitter data transmission in Time-Sensitive Networking (TSN). However, existing TAS-based traffic scheduling algorithms suffer from either high scheduling failure rate or heavy computation overhead. Such limitations make the algorithms unable to satisfy some TSN applications with harsh scheduling requirements like ultra-low latency and frequent scenarios reconfiguration requirements, such as smart factories in industrial control. Therefore, more efficient traffic scheduling algorithms are required for the specific TSN applications. To achieve this goal, a Node Bundle Scheduling (NBS) algorithm is proposed in this paper. NBS is based on a TAS traffic scheduling abstraction which greatly simplifies the scheduling problem under the premise of sacrificing a certain amount of bandwidth. To improve the scheduling success rate and optimize the scheduling efficiency, it considers resource allocation in both spatial and temporal dimensions. NBS is compared with typical and state-of-the-art algorithms under different industrial topologies. The results show that the scheduling success rate of NBS is 34.25% higher than that of Tabu Search under low transmission latency scenarios. Compared with the typical SMT solver, NBS can reduce the time overhead by over 99.9% in some complex scheduling scenarios, at a cost of extra 11.86% bandwidth consumption.