基于一次性突发原则的TTE网络实时性能优化  

Real-time performance optimization of TTE network based on“pay bursts only once”principle

作　　者：郑重[1] 赵露茜[1] 何锋[1] 熊华钢[1] 卢广山[1] ZHENG Zhong;ZHAO Luxi;HE Feng;XIONG Huagang;LU Guangshan(School of Electronic and Information Engineering,Beihang University,Beijing 100083,China)

机构地区：[1]北京航空航天大学电子信息工程学院,北京100083

出　　处：《北京航空航天大学学报》2021年第12期2503-2513,共11页Journal of Beijing University of Aeronautics and Astronautics

基　　金：国家自然科学基金(62071023)。

摘　　要：确定性通信的发展,促进了时间触发概念的引入。时间触发以太网(TTE)通过提供3种流量类别来支持混合安全性的实时应用:时间触发(TT)流量,具有完全的时间确定性;速率约束(RC)流量,具有确界的端到端延迟;尽力传(BE)流量。如何实现时间触发机制下RC流量实时性能的紧性分析,仍然是决定TTE网络顺利应用的开放式问题。在FIFO服务策略的假设下,将"一次性突发原则"的分析方法引入到TTE网络中,以观察该原则在时间触发网络性能分析中的影响。不同于航空电子全双工以太网(AFDX),具有更高优先级的TT流量会对RC流量的延迟分析产生关键影响,从而导致一次性突发分析的复杂性。通过建立聚合TT流量在及时阻断模式下的到达曲线模型,从而获得单条RC流量端到端的服务曲线模型,基于此实现了RC流量的最坏情况端到端延迟(WCD)评估,进一步完成了一次性突发原则下的分析对比。相较于已有工作,一次性突发原则可以得到RC流量更精确的最坏端到端延迟上界评估结果,有助于改善TTE网络性能评价紧性。通过A380拓扑组网案例的对比分析,相比于传统方法,所提方法RC流量平均延迟减少了12.05%。The development of deterministic communication promotes the introduction of time-triggered concepts.Time-Triggered Ethernet(TTE)network supports real-time applications of mixed safety by providing three traffic classes,including Time-Triggered(TT)traffic,which has complete time certainty,Rate-Constrained(RC)traffic,which has bounded end-to-end delay,and the Best-Effort(BE)traffic.How to realize the tight analysis of real-time performance of RC traffic under time-triggered mechanism is still an open problem that determines the smooth application of TTE network.Under the assumption of First Input First Output(FIFO)service,this paper introduces the analysis method of“pay bursts only once”principle into TTE network to observe the influence of this principle on the performance analysis of time-triggered network.Different from Avionics Full-Duplex Switched Ethernet(AFDX),TT traffic with higher priority will have a key impact on the delay analysis of RC traffic,resulting in the complexity of“pay bursts only once”principle analysis.In this paper,the arrival curve model of aggregated TT traffic in the timely blocking mode is established,and the end-to-end service curve model of single RC traffic is obtained.Based on this model,the Worst-Case end-to-end Delay(WCD)evaluation of RC traffic is realized.Compared with those in the existing studies,this method gives a tighter upper bound of the WCD for RC traffic,which is helpful to improve the tightness of TTE network performance evaluation.Through the comparative analysis of A380 topology networking cases,compared with the traditional method,the proposed method reduces the average delay of RC traffic by 12.05%.

关 键 词：时间触发以太网(TTE) 实时性分析 网络演算 FIFO服务 延迟上界 

分 类 号：TP393.1[自动化与计算机技术—计算机应用技术]