Survey on Traffic Scheduling in Time-Sensitive Networking

Many industry field applications like industrial control, avionics, in-vehicle networks, and mobile prequel networks require deterministic low-latency network transmissions. In order to achieve these transmission requirements, the IEEE 802 time-sensitive networking (TSN) working group extends standard Ethernet to TSN, which attracts continuous attentions from both academia and industry. Traffic scheduling is the core mechanism in the TSN standard system, where the scheduling algorithm determines the transmission order and time period of each data frame on egress ports of all switches to meet the respective delay and bandwidth requirements of traffic and optimize transmission performance at the same time. In this paper, we first describe the formalization of traffic scheduling problem in TSN, introduce network and traffic models, and conclude the scheduling constraints and goals. A simple example is employed to illustrate the traffic scheduling task and procedure. Then we analyze and summarize existing TSN traffic scheduling mechanisms, focusing on their solved problems, concerned traffic type, optimized performance metrics and solving algorithms. Finally, the design space and development trends of future TSN traffic scheduling are discussed, and a novel idea of joint static traffic planning and dynamic traffic scheduling is proposed in response to the existing problems of current scheduling mechanisms.