Delay-Based Shaper With Dynamic Token Bucket Algorithm for Deterministic Networks

Abstract

To improve the experience of real-time interactive applications based on video and audio, there is a growing demand to realize deterministic networks that can transmit these media with low latency. In recent years, various deterministic network technologies have been studied such as Time Sensitive Networking(TSN). Time slot allocation type schemes such as Time-Aware Shaper (TAS) offer guaranteed delayed determinism and zero-jitter, but suffer from low network accommodation efficiency. Shaper-based techniques such as Asynchronous Traffic Shaping (ATS) provide high network accommodation efficiency and delay determinism inside the network. However, if the input traffic from the sender is bursty, End-to-End delay increases due to the shaping delay caused by the shapers at the edges of the network. In this paper, we propose Delay-Based Shaper (DBS), which dynamically controls the bandwidth while shaping the bursts so that the upper bound of the shaping delay is protected. In addition, we also propose a Dynamic Token Bucket Algorithm (DTBA) that extends the conventional token bucket algorithm to implement DBS. We show that DBS can both shape bursts and comply with the upper bound of shaping delay by comparing the behavior when bursts are input via a conventional shaper. We also demonstrate good End-to-End delay determinism and high network accommodation efficiency by applying DBS to the edge of the network.