Enhanced System Design and Scheduling Strategy for Switches in Time-Sensitive Networking

Time-Sensitive Networking (TSN) is a new set of amendments that guarantee the quality of service (QoS) of time-critical and safety-critical Ethernet applications. The guard band mechanism prevents time-sensitive traffic from colliding with non-time-sensitive traffic, causing potential bandwidth waste. Moreover, most of the existing scheduling strategies only consider Audio Video Bridging (AVB) traffic and Time-Triggered (TT) traffic, resulting in Best Effort (BE) traffic not being scheduled de facto. This article proposes a new system design and scheduling strategy for TSN switches. The size-aware group weighted round robin (SGWRR) strategy is proposed to schedule AVB queues according to subperiods, reducing the average scheduling intervals of the AVB frames. The entire scheduling cycle is divided into a protected slot and an unprotected slot, and dynamic programming is used to minimize guard band waste. An old queue priority (OQP) strategy is also proposed to provide scheduling opportunities for BE queues. A simulation of OMNet++ shows that SGWRR can achieve low average scheduling intervals while improving bandwidth utilization by 5.66% and that OQP can enhance BE scheduling opportunities by 21.9% under our experimental conditions compared with existing methods.