一种基于二级队列调度的时间敏感网络帧抢占机制  

A frame preemption mechanism based on two-level queue scheduling in time-sensitive network

作　　者：王紫涵 刘泽响[1] 徐丹妮[1] 唐金锋 李泽亚 WANG Zihan;LIU Zexiang;XU Danni;TANG Jinfeng;LI Zeya(Xi'an Microelectronics Technology Institute,Xi'an 710054,China)

机构地区：[1]西安微电子技术研究所,陕西西安710054

出　　处：《微电子学与计算机》2024年第6期65-72,共8页Microelectronics & Computer

摘　　要：作为工业以太网、无人驾驶、航空电子等网络应用场景的核心技术之一,基于以太网的时间敏感网络(Time Sensitive Network,TSN)能够提供低时延、低抖动的确定性传输服务,一直以来广为业界关注。TSN流量调度是解决帧传输的确定性和有界时延问题的关键技术,其中帧抢占技术通过对不同实时性要求的数据进行划分且允许高优先级实时数据打断低优先级非实时数据的传输,来保证TSN网络中高优先级实时数据的超低时延。然而,帧抢占机制设置“保护带”以隔离高低优先级两类数据的传输,导致在保护带内网络链路空闲。本文针对保护带引起的链路带宽损耗问题,对帧抢占机制进行改进,提出一种基于二级队列调度(Two-Level Queue Scheduling,TLQS)的帧抢占机制。该机制通过设置两组队列,将经过基于门控的时间感知整形机制(Time-Aware Shaper,TAS)调度的非实时数据进行分流、存储与仲裁调度,并利用保护带闲置带宽进行传输选择。仿真结果表明,相较于使用标准帧抢占机制,基于TLQS的帧抢占机制在降低抢占产生的额外开销的基础上,能够有效提升网络带宽利用率。As one of the core technologies of network application scenarios such as industrial Ethernet,unmanned driving and avionics,Ethernet-based Time Sensitive Network(TSN)can provide deterministic transmission services with low delay and low jitter,which has been widely concerned by the industry.TSN traffic scheduling is a key technology to solve the deterministic and bounded delay problem of frame transmission.The frame preemption technology ensures the ultra-low delay of high-priority real-time data in TSN by dividing the data with different real-time requirements and allowing the transmission of high-priority real-time data to interrupt the transmission of low-priority non-real-time data.However,the frame preemption mechanism sets a"guard band"to isolate the transmission of high and low priority data,resulting in idle network links in the guard band.Aiming at the problem of link bandwidth loss caused by guard band,this paper improves the frame preemption mechanism and proposes a frame preemption mechanism based on Two-Level Queue Scheduling(TLQS).By setting up two groups of queues,the non-real-time data scheduled by the gated Time-Aware Shaper(TAS)mechanism is diverted,stored and scheduled for arbitration,and the idle bandwidth of the guard band is used for transmission selection.Simulation result shows that compared with the standard frame preemption mechanism,the frame preemption mechanism based on TLQS can effectively improve the network bandwidth utilization on the basis of reducing the additional overhead caused by preemption.

关 键 词：时间敏感网络 TAS 帧抢占 二级队列调度 保护带 

分 类 号：TN915.04[电子电信—通信与信息系统]