A Design of Token Bucket Shaper Aided with Gate Control List in Time-Sensitive Networks

Ethernet-compatible interconnections can be widely used in avionics due to its flexibility and scalability. With the growing demand for high bandwidth, low latency, and reliability, Time-Sensitive Networking (TSN) has been proposing a series of standards to improve the real-time performance of Ethernet, among which flow control strategies including Credit Based Shaping (CBS), Time-Aware Shaping (TAS), and Asynchronous Traffic Shaping (ATS) have been applied.Taking advantage of the globally synchronized clock, the TAS mechanism can achieve low latency for Time-Triggered (TT) traffic communication by establishing completely non-overlapping time windows, with the difficulties in higher system complexity. Using the token bucket shaping method, ATS can provide per-flow logical isolation for AVB traffic without the need for global clock synchronization. However, the improper parameter configuration of Committed Information Rate (CIR) and Committed Burst Rate (CBS) in ATS will lead to a dramatic rise in transmission latency.In this paper, to realize timing gate control under low complexity, a design of the flow control strategy, Gate Controlled Asynchronous Traffic Shaping (GCATS), which incorporates the Gate Control List (GCL) of TAS into the token bucket shaping method, is introduced. With the clock synchronization on the current node, GCATS reshapes traffic using an ATS-like per-flow token bucket method, reducing the computational cost and time constraints caused by the global clock synchronization of TAS. Simulation results show that, compared to TAS, GCATS configured with GCL tables of different granularity can provide fine-grained service for lower-priority traffic and reduce the transmission delay, that is, when given a default GCL, GCATS serves specific traffic without the need for network-wide clock synchronization.