新一代智能变电站波分复用无源光通信网络性能研究

针对智能变电站通信系统中出现的网络时间同步、传输时延以及抖动较大的问题,对智能变电站通信网络复用方式进行了研究,提出了波分复用网络架构模式。新一代智能变电站波分复用无源光通信网络架构基于无源光网络和虚拟的点对点双向传输链路,采用业务隔离等技术,保证整个网络的稳定和可靠。通过仿真得到波分复用无源光网络的通信业务的性能指标并加以分析,证实了变电站业务对通信网络的要求均能够通过波分复用通信网络实现,该通信网络可用于变电站通信网。     

新型ICT网络中的一种动态路由波长分配算法

根据新一代电力ICT网络模型的要求,对智能光网络技术的动态路由和波长分配策略及其对ICT网络性能的影响进行了研究,提出了基于分层图模型的动态路由选择和波长分配优化算法.在不设定备用路由的情况下,以网络链路上的可用光通道数作为链路代价,综合考虑路由跳数,把连接请求建立在优化可用信道数和跳数选择的光通道上,从而使网络负载平衡的同时,尽可能减少网络资源的占用.仿真结果表明,所提算法能有效地降低网络阻塞率,性能优于分别求解两个子问题的传统路由和波长分配算法.     

山西电力主干波分复用智能网状网的建设

波分复用技术在长途通信中已经得到了广泛的应用,但传统的波分复用技术给运维带来了诸多不便.文章从山西电力通信网及现网的各类业务需求出发,介绍了山西电力主干光纤波分复用智能网状网建设的网络建设情况,详细说明网络中采用的设备板卡的应用及配置,并以朔州变为例进行阐述.     

电力波分复用网络中基于软管模型的生存性设计

生存性设计是规划电力通信波分复用(WDM)网络时必须考虑的问题。传统的方法根据各节点对的峰值速率来制定保护规划方案,也并未考虑光纤链路之间共享物理资源的情况,既不准确又浪费资源。为解决上述问题,提出了一种新的计算共享风险链路组的失效概率模型,并以此为基础,提出了基于软管不确定业务量模型和共享风险链路组的分级保护算法——HSP算法,并通过计算机仿真对该算法的性能进行了评估。结果表明,HSP显著提高了找到保护路径的可能性,从而降低了受损业务无法恢复的概率。失效概率模型和HSP算法还应用到了某省级电力波分复用核心网络的成效评估和规划设计中,作为评估该省电力骨干光传输网络建设成本和可靠性的依据。     

基于EPON的配电通信网的动态带宽分配方案

结合以太无源光网络（EPON）的技术特点及智能配电网对通信系统的需求,设计了一种可用于配电通信网的EPON带宽分配方案。利用高阶移动平均模型,对高优先级业务在等待时隙中额外收到的流量进行预测并分配授权带宽,保证了高优先级业务性能,杜绝了较低优先级业务分配的时隙被挤占的现象。采用Round-Robin调度算法对处于高负载下的ONU进行提前发送,显著提高了系统整体性能并兼顾了分配的公平性。理论分析和仿真结果表明,所提出的动态带宽分配方案能够显著提高业务延时性能,增加网络吞吐量,并降低网络丢包率。     

基于光纤光栅传感器的变压器测温系统设计

阐述了基于光纤光栅传感器的变压器测温系统的工作原理和硬件、软件的设计过程.Bragg光栅的中心波长是温度的线性函数,由FBG-T-01光纤传感器通过波分复用原理构成光纤传感器阵列作为测温元件,运用可调谐发布里—珀罗腔(F-P)滤波解调法对波分复用的光信号进行波长的检测.为了能够及时发现变压器绕组温度异常问题,设计的变压器测温系统同时将测点温度和测点温升速率作为判据来判断变压器绕组温度是否正常.测试结果表明,光纤光栅测温系统精度高,稳定性好,能够很好完成变压器测温任务.     

新型ICT网络中的一种动态路由波长分配算法

根据新一代电力ICT网络模型的要求,对智能光网络技术的动态路由和波长分配策略及其对ICT网络性能的影响进行了研究,提出了基于分层图模型的动态路由选择和波长分配优化算法。在不设定备用路由的情况下,以网络链路上的可用光通道数作为链路代价,综合考虑路由跳数,把连接请求建立在优化可用信道数和跳数选择的光通道上,从而使网络负载平衡的同时,尽可能减少网络资源的占用。仿真结果表明,所提算法能有效地降低网络阻塞率,性能优于分别求解两个子问题的传统路由和波长分配算法。     

WDM及其在电力通信网的应用

介绍了波分复用系统的组成及其主要元器件的功能,重点介绍了光放大器、分波/合波器、波长转换器、光分插复用器等的功能与应用,深入探讨了WDM系统在电力专网应用设计中应考虑的几个关键技术问题。针对电力专网的特点与现状,提出了电力专网应用波分复用系统组网的具体策略,对WDM系统在电力专网的推广应用具有指导意义。     

密集波分复用技术及全光网络

密集波分复用技术和全光网络已成为当前光通信的研究热点。密集波分复用技术具有超大容量、对数据信号“透明”、组网灵活等传统光纤通信技术无法比拟的优点,成为未来光纤通信的支撑技术,也成为全光网络的关键技术之一;全光网络是指对信号的传输与处理等均在光域中进行,全光网络与目前传统的通信网络相比容量更大、可扩充性和可重构性更强、网络结构更简单、对数据完全“透明”。文中对密集波分复用技术、密集分波分复用系统的构成、全光网络的概念及其网络形式进行了介绍。     

可波长重用的高可靠性对环型电力通信光接入网

为满足新型电力系统末端通信接入越来越高的大容量和可靠性传输要求,提出一种新颖的对环型波分复用电力通信光接入网架构。通过全新设计的切换模块与交换模块,充分利用各类光器件特性,对中心端局和远端节点分别进行重构。所提设计使得网络兼具了规模化和模块化的特性,同时采用对环型架构搭建,重新设计了光信号在网络中的传输方式,根据在不同运行模式下的传输方式切换使得整体网络不仅具备高可靠性,还能实现波长的多重复用。通过建模分析与仿真测试,上述功能及特性均得到验证,网络具备良好的传输性能。     

基于遗传算法的城市交通优化分配

随着智能交通系统的发展,交通分配及交通控制已成为重要的研究和发展项目之一。着重研究了城市交通出行量的路网分配问题,对兼顾系统最优和用户最优的路网动态平衡分配模型采用遗传算法求解,并用Visual C＋＋6.0编写的模型优化算法程序对拟定的简例实施优化控制,运行结果表明该方法是行之有效的。     

A New Light-Path Setup Scheme for Dynamic Traffic in Ring-based Optical Networks

A simple and fast ring management token (RMT) wavelength reservation method for dynamic traffic in multi-ring wavelength-routed networks is proposed. The RMT is an agent that can control and manage the used wavelength in the network efficiently. We show that the proposed scheme achieves a high performance in terms of setup delay and loss probability. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

电力骨干光传输网络的动态波道均衡路由波长分配算法

提出一种电力光传输网络中基于业务的路由波长分配(RWA)算法。算法设计旨在解决复杂电力光传输网络拓扑下,多业务等级请求路由波长分配问题。首先根据复杂网络拓扑情况与业务请求状况,完成业务请求合并与对跨域业务的路由选择;其次依据域内与域间优先级设定策略,完成业务请求优先级设定,并按照优先级顺序,采用分组波长分配算法完成波长分配。仿真结果表明,算法在处理大规模复杂网络拓扑、多业务等级路由波长分配问题上,有效降低了网络请求阻塞率,提高了光传输网络资源利用率。     

基于车载通信网络的认知无线电信道分配技术的研究

车载通信网络的移动性对无线网络的信道分配提出了高要求,认知无线电技术能适应这一要求。将认知无线电的信道分配技术运用到车载通信网络中,根据实际交通状况对车载通信网络进行建模,主用户和认知用户分别实体化为无线网络用户及车载通信用户;运用协作最大化带宽和（CMSB）算法对认知用户进行信道分配。仿真分析结果表明在给定的车载通信网络模型下,CMSB能极大地优化网络吞吐量,并能保证一定的分配公平性。     

Variable length dynamic addressing based on network traffic distribution in wireless sensor networks

In this paper, a novel dynamic addressing scheme for wireless sensor networks (WSNs) is proposed by using variable length coding. A WSN is typically composed of numerous tiny energy-constrained sensor nodes with limited information processing and data storage capabilities; thus, the energy-efficient strategy is the key issue in designing protocols for WSN. Traditional addressing strategies adopt flat addressing (static and uniform addresses) for sensor nodes. However, the proposed variable length dynamic addressing (VLDA) for sensor nodes is based on the fact that different nodes in the network have uneven traffic loads. Therefore, nodes with more data to receive or send are allocated with shorter addresses. Whether a node is busy or not is determined by the network traffic distribution (NTD), which is defined as the number of data packets each node has received or sent in a period of time. Sensor nodes’ energy is saved by VLDA scheme; hence, the wireless sensor network’s lifetime is extended. In the simulation, a 20% improvement has been achieved through the addressing scheme compared to traditional flat addressing.     

Dynamic multicast traffic grooming in WDM networks

Dynamic multicast traffic grooming in wavelength division multiplexing (WDM) networks was analyzed to minimize networkwide costs and to increase the network resource utilization. A network model was developed for dynamic multicast traffic grooming with resource constraints and an algorithm that can provide quality of service (QoS) was proposed. The QoS is measured by the maximum number of lightpaths passing between the source and the destinations. The blocking probability of the algorithm was assessed in simulations. The results show that a higher QoS requirement results in higher blocking probability, and when the QoS requirement is low, changes in the QoS requirements have only small effects on the blocking probability. __________ Translated from Journal of Tsinghua University (Science and Technology), 2005, 45(4): 437–440 (in Chinese)     

Development of terabit‐class super‐networking technologies

We propose terabit‐class super‐networking technologies, designed to improve the scalability, reliability and performance of optical Internet protocol networks. Our technologies comprise both intra‐ and interlayer traffic engineering technologies. The intralayer technologies include an optical path protection scheme, an electrical load‐balancing scheme and a distributed content‐caching scheme. These provide an effective and economical way of improving performance and reliability. The interlayer technologies include both traffic‐driven and application‐driven optical cut‐through control schemes and a policy control scheme. These provide an effective and economical way of improving scalability and performance. The feasibility of our technologies has been verified by means of experiments using prototype systems. The results showed that the different techniques can be combined to form a single network architecture for dynamic optical path control. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

基于贪心流量调度的智能变电站过程层网络拓扑高可用无缝冗余配置方法

泛在电力物联网背景下,智能变电站中负责运行状态上传与控制命令下达的过程层网络负载将急剧升高。传统IEC61850标准协议中的高可用性无缝冗余(High-Availability Seamless Redundancy,HSR)通信链路配置方法由于数据副本在存在环路的网络内循环产生额外流量与额外传输延时,存在信息传输实时性差的缺点。因此,提出基于贪心流量优化算法的过程层网络拓扑高冗余无缝配置方法。首先,在分析采用HSR技术的智能变电站过程层网络工作原理的技术上,提出两种高可用性无缝冗余配置方案:交叉(Cross-Links,CLs)方案与四连通环(Four-Connected Rings,FCRs)方案。其次,为避免过程层网络在流量汇聚时易产生拥塞导致传输时效性变差,提出基于贪心算法的流量调度策略。最后,基于Opnet的变电站仿真算例表明,与传统网络拓扑配置方案相比,所提方案的数据平均传输跳数与传统拓扑方案比下降50%,而采用贪心算法的过程层网络流量调度策略在数据拥塞时的传输延时、丢包率和吞吐量衰退服务分别降低32.7%,63.5%和33.3%。因此,所提方案能够显著提升智能变电站过程层网络性能。     

Field demonstration of in-line all-optical wavelength conversion in a WDM dispersion managed 40-Gbit/s link

The development of wavelength-division multiplexing (WDM) all-optical transport networks is an interesting solution to increase the capacity of long-haul transmission systems and to solve the route-exhaust problems of metropolitan networks, driving down the cost of that traffic. Routing can be achieved using a transparent device able to select and interchange wavelengths, such as an all-optical wavelength converter. In this paper, an optical transport network over an embedded link located between Rome and Pomezia in Italy is emulated. The transmission has been realized along a WDM, 5/spl times/100 km long, dispersion managed link at 40 Gb/s. The in-line rerouting process has been controlled by means of an all-optical wavelength converter realized with a periodically poled lithium niobate waveguide. Moreover, a polarization-independent scheme for the converter has been exploited to allow the in-line signal processing. This scheme is based on the counterpropagation of TE and TM signal components along the same guide and results extremely compact. In this paper it is demonstrated that wavelength conversion and rerouting add no penalty with respect to the simple transmission along the embedded cable. This result seems to be another step toward the feasibility of true all-optical networks.     

海南电网通信网络建设分析

对海南电网各种电力通信业务进行了分类与整合;针对每类业务的特性,给出了其承载网络及网络建设技术体制;结合网络覆盖范围,利用模糊数学与矩阵分析等工具给出了各网络承载业务的分布模型及网络结构建设方案;并结合业务流量分析,导出了各网络的建设带宽及基础承载网络的带宽分配模型。该方案清晰了网络建设,优化了资源利用,方便了网络的维护管理。