HSTC:TSN中的混合流量调度机制

针对借助时间敏感网络（TSN）实现工业网络中混合流高效传输的问题,提出了一种结合时间感知整形与循环排队转发的混合流量调度机制。该机制通过求解网络最小时隙并调整预订流量采样周期,大幅降低时间敏感流对传输资源的占用;并针对流预留流,提出奇偶映射方案及流偏移规划算法,实现对大带宽流的调度规划。仿真结果表明,所提机制的系统带宽利用率可达88%,并提升52%的网络调度成功率上界,实现了TSN中混合流的高效调度。     

时间敏感网络流量整形技术综述

在保持与标准以太网兼容的基础上,基于以太网协议的时间敏感网络(TSN)通过建立网络时间同步、流量调度等手段,使得网络同时具备传输实时信号的能力.流量整形作为TSN关键技术,在解决时间敏感流传输的实时性和确定性问题方面至关重要.TSN目前主要的流量整形措施有4种,包括基于信用的整形技术(CBS)、时间感知整形调度技术(T...     

基于OMNeT++的时间敏感网络延迟仿真

为了研究时间敏感网络(Time-Sensitive Networking,TSN)中不同调度算法下流量的端到端延迟特性,基于OMNeT++搭建了TSN仿真平台,提出了支持TSN调度机制的算法模块和调度模型,并在不同网络场景下对调度机制进行仿真,分析不同调度机制下流量延迟仿真结果和延迟影响因素,得到了各调度算法下流量的延迟特性,研究结果对时间敏感网络延迟研究具有一定参考价值。     

一种基于时间敏感网络的变电站确定性网络架构优化方法

新型智能变电站网络基于传统以太网尽力而为转发机制,在突发大流量时难以保证敏感流量可靠传输。文中提出一种基于TSN（时间敏感网络）的变电站网络架构优化方法,根据敏感SV报文的传输特性,采用TSN协议簇中IEEE802.1Qbv、IEEE 802.1AS结合的时间门控调度机制,在敏感流量到来的时隙开辟专用通道保证其以最佳时延通过;采用TSN协议簇中IEEE 802.1Qci技术对网络所有流量进行过滤管理,保障敏感流量能进入专用通道并阻挡其他流量误入。经模拟变电站实际场景组网验证表明,相对于传统以太网,时间敏感网络能确保网络拥塞时敏感流量能够以最大时延2.17μs、平均抖动0.16μs的最佳时延抖动传输。     

交换机的时间感知整形器的设计

时间敏感网络（TSN）是应用于未来工业网络实时性的一种增强型以太网技术。作为主要关键技术之一,流量调度机制决定了时间敏感网络数据传输的确定性和实时性,对其进行研究是非常具有价值的。在研究了802.1Qbv标准中所定义的时间感知整形器的实现机制和完整的处理流程的基础上,提出了一种时间感知整形器调度机制的设计。将整个设计在自研的TSN交换机平台上进行组网测试,验证了调度器可支持时间敏感业务流的确定性传输。     

TSN中时间同步技术研究及实现

时间敏感网络（TSN）对在以太网上传输的时间敏感流进行确定性控制,保证了网络传输实时数据的能力。时间同步是TSN技术中的基石,保障了网络数据传输的实时性和确定性。首先对建立时钟同步生成树和选择最佳主时钟的过程进行介绍;然后对路径延迟时间计算的原理进行描述;进而重点论述了各节点中进行时间同步时的计算推导过程。最后探索了一种流量整型技术,通过一个实验展示了时间同步在TSN流量整型中的重要作用。     

时间敏感网络中基于网络演算的队列分析与优化

时间敏感网络（TSN）中循环队列转发（CQF）机制保留了时间感知整形中门控调度的转发可控特性，同时又降低了门控列表配置的复杂度，但是缓存队列的长度作为一个关键参数直接影响着网络的调度性能，并且在实现时受到硬件资源的约束。为了寻找到合适的CQF队列长度值以实现网络系统设计的性能和成本的优化，提出了一个基于网络演算的CQF性能分析方法。通过曲线模型的构建和计算，分析流量传输时延和积压的性能上界值，从而选择出合适的队列长度值。通过不同场景的实验，得到了不同流特性参数对队列长度选择的影响。     

时间敏感网络中基于EDWF-MTTF的启发式调度算法

随着工业控制和信息网络的快速融合发展,基于以太网的时间敏感网络受到了广泛关注。时间敏感网络采用时间触发通信调度来保证数据传输的确定性。然而,现有调度算法难以快速计算大规模周期性流量的调度表。因此,设计了基于带权重的最早截止时间-最大传输时间优先的启发式调度算法,通过灵活适配流量排序权重以及回溯增强等方法,可以在较短时间内解决工业自动化场景中大规模流量的调度问题。实验结果表明,相比经典整数线性规划方法,带权重的最早截止时间-最大传输时间优先的启发式调度算法能更快地计算出大规模周期性流量调度表的较优解。     

时间敏感网络研究现状与关键技术探析

随着现代工业信息化技术与网络管理运维技术的不断融合,可以较好确保高实时性与确定性传输的时间敏感网络已成为工业互联网和车联网等领域重点研究的技术方向之一。时间敏感网络符合标准以太网规范,具备流量调度与时间感知能力,通过交错传输周期性数据与非周期性数据来提供业务流量确定性传输服务。旨在对TSN这一新兴技术领域进行调研和分析,在对现有研究工作进行归纳总结的基础上,重点分析了TSN涉及的主要关键技术,并对其可能的应用场景和未来发展进行讨论和展望。     

下一代车载时间敏感网络架构设计与调度评估

智能网联汽车(Intelligent Connected Vehicle, ICV)是未来汽车行业发展的主要方向之一,其对车载网络通信的带宽、延迟出了较高的要求。针对该要求,提出了基于以太网的电子电气架构(Electronic/Electrical Architecture, EEA);在分析基于IEEE802.1Qbv的时间敏感网络(Time-sensitive Networking, TSN)传输调度机制的基础上,实现了控制数据流和传感器数据流的增量式调度。通过评估和对比,TSN拥有更高的带宽、更低的传输时延,有望成为下一代车载网络。     

有线无线融合的卫星时间敏感网络流调度研究

随着空间通信任务日趋复杂化,尤其是对时间敏感的需求不断提升,一方面要求星内系统的高带宽、可靠性和实时性;另一方面星间无线链路也应具备低时延和高可靠性.但由于卫星内部有线链路与星间无线链路差异大,业务数据经过有线和无线链路联合传输时,容易引发节点拥塞,而无法保障时敏业务的时延有界需求.为了提升数据在空间网络传输的实时性,...     

时间敏感网络（TSN）及无线TSN技术

时间敏感网络（TSN）在以太网的基础上提供端到端极低时延和高可靠性的数据传输,适用于时延敏感型应用,广泛应用于自动驾驶、工业互联网等场景。首先总结了TSN的特点,并详细阐述了TSN标准的工作原理和特性,重点介绍了在无线网络中提供确定性时延和可靠数据传输的网络技术,即无线TSN技术。此外,通过TSN的应用场景简要分析了TSN的应用案例。最后探讨了TSN和无线TSN技术及其在工业场景中应用存在的挑战和问题,并展望了未来的研究方向。     

面向航天器有线无线混合场景的流调度机制研究

随着各国深空探测任务的开展,空间站的建设需求日益增加,而航天器内部大量的数据通信总线在一定程度上影响了航天器的有效载荷。因此,该文将无线通信方式引入到航天器通信系统设计中,但传统无线通信难以保障时敏数据的端到端传输时延,该文提出了一种有线无线融合的时间敏感网络(TSN)流调度方案。设计了一种上下行时隙分离的TDMA时隙分配机制,通过对航天器内部业务类型与有线无线融合传输链路的时延关系进行建模分析,构建了以时敏业务平均端到端时延最小的目标函数,采用粒子群算法对时隙分配方案进行快速求解。最后在Pycharm平台对所提算法进行对比测试,并在EXata网络仿真平台搭建航天传感器采集网络进行验证。实验结果表明,该文所提出的有线无线融合流调度方案能为时敏业务提供稳定、有界的时延保障。     

时间敏感网络的关键协议及应用场景综述

随着信息技术的发展,以物与物作为通信主体的场景需求不断增加,如工厂自动化控制、自动驾驶等,这类通信对数据传输时延的要求远远超出了传统以太网的可控范围,时间敏感网络应运而生。时间敏感网络是以标准以太网为网络基础,提供确定性信息传输的标准化技术,通过时间感知的调度机制最小化抖动,并为时间敏感应用提供可靠的数据传输保障。通过对时间敏感网络相关国际标准的说明,介绍了其核心特性及机制,并在车载网络、工业互联网、航空电子网络和移动前传网络等应用场景进行了分析和研究。     

Multicode-DRR: a packet-scheduling algorithm for delay guarantee in a multicode-CDMA network

Multicode-code division multiple access (CDMA) supports a variety of transmission rates within a wireless network. However, providing packet-delay guarantees in a multicode-CDMA network is difficult because its transmission capacity is time varying even in an error-free wireless channel. In this paper, we develop a packet-scheduling algorithm called multicode-deficit round robin (DRR) as a solution to the problem. The basic idea of multicode-DRR is to separate the time-varying capacity into a deterministic component and a variable component, and to use these components to serve time-sensitive and non-time-sensitive traffic, respectively. With the proposed scheduling algorithm, simulation results have confirmed that the maximum packet delays for time-sensitive traffic never exceed their target upper bounds.     

Group-scheduling mechanism for large-scale time-sensitive network

In order to achieve the deterministic delay of time-triggered traffic in a large-scale time-sensitive network,a kind of group-scheduling mechanism was proposed.By designing a topology pruning strategy and a flow grouping strategy based on spectral clustering,the impact of the rapid increase in network topology scale and traffic scale on the speed of scheduling response was avoided,and the scheduling calculation efficiency was improved.The results of experiment show that the mechanism can solve the model in a relatively short time for large-scale scheduling problem and achieve a relatively high scheduling success rate.     

Traffic scheduling in hybrid WDM–TDM PON with wavelength-reuse ONUs

Hybrid WDM?CTDM PON (wavelength division multiplexing?Ctime division multiplexing passive optical network) that applies wavelength-independent or colorless ONU (optical network unit) technologies will further reduce implementation and maintenance expenses. The ??wavelength-reuse?? colorless ONU technology imposes a physical constraint in the hybrid WDM?CTDM PON that the same wavelength is used for both upstream and downstream traffic transmission of an ONU. This physical constraint brings a new challenge to developing traffic scheduling algorithms in the network, as upstream traffic scheduling is no longer independent of downstream traffic scheduling and the existing traffic scheduling algorithms that treated the upstream and downstream traffic independently cannot be applied in this case. We propose a new traffic scheduling algorithm that takes both directions?? traffic scheduling into account at the same time. A logical PON concept is defined, and wavelength resource sharing is performed based on reconfiguring logical PONs. Simulation study on this algorithm is conducted, and results show that it achieves efficient wavelength and bandwidth resource sharing in the network.     

A novel scheduling scheme to share dropping ratio while guaranteeing a delay bound in a MultiCode-CDMA network

A MultiCode-CDMA network that is capable of providing quality-of-service guarantees will find widespread application in future wireless multimedia networks. However, providing delay guarantees to time-sensitive traffic in such a network is challenging because its transmission capacity is variable even in the absence of any channel impairment. We propose and evaluate the performance of a novel transmission scheduling scheme that is capable of providing such a delay guarantee in a MultiCode-CDMA network. The proposed scheme drops packets to ensure that delays for all transmitted packets are within the guaranteed target bounds, but packets are dropped in a controlled manner such that the average dropping ratios of a set of time-sensitive flows can be proportionally differentiated according to the assigned weighting factors or shares. We provide extensive simulation results to show the effectiveness of the proposed scheme as well as to study the effects of various parameters on its performance. In particular, we show that it can simultaneously guarantee a delay upper bound and a proportionally differentiated dropping ratio in a fading wireless channel for different traffic loads, peak transmission rates, and weighting factors of individual flows.     

Efficient scheduling of transmissions in optical broadcast networks

All-optical networks (AONs) with a broadcast-star based physical topology offer the possibility of transmission scheduling to resolve channel and receiver conflicts. This paper considers the problem of scheduling packet transmissions in a wavelength-division multiplexed (WDM) optical network with tunable transmitters and fixed-tuned receivers. The scheduling problem is complicated by tuning latency, a limited number of channels, and arbitrary traffic demands. We first analyze scheduling all-to-all packet transmissions and obtain a new lower bound for the schedule length. The lower bound is achieved by an algorithm proposed by Pieris and Sasaki (1994). We then extend the analysis to the case of arbitrary traffic demands and obtain lower bounds for the schedule length. Two constructions for scheduling algorithms are provided through list scheduling and multigraphs. The upper bounds so obtained not only provide performance guarantees with arbitrary demands, but also nearly meet the lower bound in simulations