WDM系统中电监控信道方法的研究

波分复用(wavelength-Division Multiplexing,WDM)技术的发展大大提高了通信网络的传输容量,将成为下一代骨干网络的核心传输方式.在WM系统光网元设备之间的通信方法中,较多的是采用光监控信道(OSC)和调顶技术(Pilot Tone),但是这两种方法的固有缺陷在城域波分系统不可避免,从而引出电监控信道(ESC)一适用于城域波分系统的基于业务开销中现有的DCC字节来进行网元之间通信的一种实现方法.该方法易于实现、可靠性高,有效降低了系统成本,提高了系统资源利用率,有较好的应用前景.     

基于光波分复用传送网网络管理的研究

对于基于 WDM的光网络来说 ,由于其承载的信息量十分巨大 ,因此网络的任何故障和失效都必将是灾难性的 ,因此研究光网络的网络管理就势在必行。本文紧扣当前城域网建设这股热潮 ,对基于 WDM技术的光城域网的网络管理进行了细致的研究 ,特别是对其网络开销的传送技术——光监控信道 (OSC)技术进行了详细的研究和探讨。     

基于光波分复用传递网网络管理的研究

对于基于WDM的光网络来说，由于其承载的信息量十分巨大，因此网络的任何故障和失效都必将是灾难性的，因此研究光网络的网络管理就势在必行，本文紧扣当前城域网建设这股热潮，对基于WDM技术的光城域网的网络管理进行了细致的研究，特别是对其网络开销的传送技术－光监控信道（OSC）技术进行了详细的研究和探讨。     

EoS技术在WDM网络光监控信道中的应用研究

通过对波分复用光网络网元设备之间管理通道技术现状及实现方案进行比较分析,指出了设计过程中需要考虑的问题.运用EoS技术设计实现了WDM系统的光监控信道(OSC)系统并完成了测试.探讨了该方法的优势,表明对WDM系统的互连互通建设具有十分重要的意义.     

宽带城域网建设分析

1宽带城域网的网络架构城域网是指覆盖城市及其郊区范围,为城域多种业务和通信协议提供综合传送平台的网络,特别是应用于大中型的城市地区,这里所讨论的宽带城域网一般是指基于已有的传输网络构建的数据网络。1.1城域传输网城域传输主要采用的技术有SDH、WDM、多业务传送节点技术和光纤直连技术。SDH技术因其技术的成熟性以及具有标准的光接口和统一的复用映射结构,有横向兼容性,是目前支撑城域传输的主要技术;随着城域网业务的突飞猛进,逐步引入WDM技术满足日益增长的容量需求;为适应数据业务的发展需要,以及支持ATM、IP和以太网业…     

上海光网公司推出城域CWDM光传输设备

上海全光网络科技股份有限公司在十一届上海国际通信展上通过现场演示,展示了上海光网公司全力推出的用于架构新一代城域宽带网络光层平台的EVERLIGHTTM CA6000、4000、2000系列城域WDM设备,在现场我们可以看到,通过CA系列设备构建三节点WDM光传输平台,配合以电端设备的VOD视频点播系统,可以让用户现场体验到高质量视频点播以及MP3音乐欣赏等宽带多媒体视音频业务的服务,突现了WDM技术在城域宽带网建设中的巨大带宽应用。     

WDM城域光传送网的网络管理

基于wDM的光网络由于承载的信息量非常巨大，网络的任何故障和失效都将造成严重的后果，因此研究这种网络的网络管理十分重要。在叙述了基于wDM技术的光网络的网络管理体系结构和特殊要求之后，着重对其网络开销的传送技术-光监控信道(OSC)技术进行了研究，井进一步探讨了光城域网环境下的OSC技术。     

像电交换一样灵活的零接触光网络

在带宽需求高增长的城域范围内,零接触光网络可以提供比传统WDM网络高94%的净现值和高达78%的运营节省。随着高带宽业务的飞速增长,一个让网络运营商头疼的问题就是:他们需要在扩充网络容量的同时,降低传输成本以保证商业运营的持续性和竞争     

城域WDM光传送网——2纤OADM环网技术概要

本阐述了一种城域WDM传送网-2纤OADM环网的主要技术，如OADM环网节点的3种基本结构、环网的保护方式、波长转换器、子速率复用和城域光网络管理等，给出了OADM环网在城域应用时应考虑的一些因素，并分析了运营商所关心的系统成本问题。     

城域WDM环网及其应用

文章阐述了城域WDM环网的节点结构、保护方式、波长转换器、子速率复用和光网络管理等,给出了WDM环网在城域应用时应考虑的一些因素,并分析了运营商所关心的系统成本问题。     

光传送网的故障管理

用分层方法讨论了光传送网络的告警管理功能,着重分析了全光网络中缺陷指示信号的起源、传输与终结问题,此外还对光监控信道的故障情况的处理方法进行了讨论。     

Robust photonic transport network implementation with optical crossconnect systems

We adopt the optical path concept to develop a photonic transport network. Because robustness is critical in a nationwide backbone network, we implement, as a first step, digital frame-based optical path network systems. NTT has developed several types of photonic transport systems. They are an optical path cross-connect system which has little quality of service monitoring large-scale integration circuit for each wavelength; a photonic transport payload assembler-disassembler, which accommodates client signals into optical path payloads and vice versa; and a repeater. The implementation of a PTS is depicted. A network-element-level operating system and an optical-network-level operating system are required to operate the WDM photonic transport network. We introduce a TMN-based network operating system. Finally, an overview of NTT's photonic transport network trial is presented     

Effect of Co permeation on spin polarized transport in a Co/organic semiconductor (OSC) structure

Co atoms will permeate into the soft organic material to form a magnetic permeated sublayer (MPS) during the fabrication of an organic spin device, such as Co/OSC/LSMO. We considered the OSC as a two-sublayer structure of MPS and pristine OSC, and then established a dynamic spin-diffusion equation to study the effect of MPS on the spin current polarization and the magnetoresistance of the device. It was found that the MPS will change the spin transport due to its different spin-flip time and mobility from that in the pristine OSC. The splitting of spin-flip times will be favorable to the spin polarization transport. Mobility of spin polarons in the MPS will be reduced due to the scattering of the Co atoms, which will weaken the spin polarization. For a given device, effect of the thickness of the MPS on the spin polarization is discussed. Finally, we calculated the magnetoresistance of a Co/OSC/LSMO device. A theoretical result which is consistent with the experimental data was obtained.     

Network architecture for optical path transport networks

This paper proposes a new layered transport network architecture on which the WDM optical path network can be effectively created. The optical path network will play a key role in the development of the transport network that will realize the bandwidth-abundant B-ISDN. This paper extends the layered transport network architecture described in ITU-T Recommendation G.803 which is applied in existing SDH networks. First, we elucidate an application example of WDM optical path networks. Next, we propose a new layered architecture for WDM-based transport networks that retains maximum commonality with the layered architectures developed for existing B-ISDN networks. The proposed architecture is composed of circuit layer networks, electrical path layer networks, optical layer networks, and physical media (fiber) networks. The optical layer is divided into an optical path layer and an optical section layer. The optical path layer accommodates electrical paths. Optical section layer networks are divided into optical multiplex section (OMS) layer networks and optical repeater section (ORS) layer networks. The OMS layer network is concerned with the end-to-end transfer of information between locations transferring or terminating optical paths, whereas the ORS layer is concerned with the transfer of information between individual optical repeaters. Finally, a detailed functional block model of WDM optical path networks, the function allocation of each layer, and an optical transport module (OTM) are developed     

Optical Burst Transport: A Technology for the WDM Metro Ring Networks

We propose a sublambda traffic-grooming scheme on wavelength-division-multiplexing ring networks, named optical burst transport. The network protocol and architecture are designed to support dynamic bandwidth allocation, which is more reasonable for bursty data traffic. To verify our network protocol and architecture, we build a testbed which supports burst-mode transmission. Also, we transmit streaming video over Ethernet as an application     

Light core and intelligent edge for a flexible, thin-layered, and cost-effective optical transport network

We present a new optics-based transport architecture that emulates fast switching in the network core via emerging fast tunable lasers at the network edge, and bypasses the need for fast optical switching and buffering. The new architecture is capable of handling both asynchronous and synchronous traffic, for dealing with various bandwidth granularities and responding to dynamic changes in end-to-end traffic demands. The architecture also reduces the amount of layering in the transport network by eliminating packet and TDM switching, keeps the network core light (lightweight and transparent), and pushes intelligence to the network edge. We discuss technical challenges that arise in the new architecture and describe possible approaches to address them.     

Impact of amplifier noise figure modeling in simulations of impairment-aware all-optical networks

In this article, we analyze and quantify the impact of the use of different amplifier noise figure models in impairment-aware optical network simulations. We compare network simulations that use three different models, two of them already known and largely employed in the literature, and a third one that we propose here, which is more appropriate to use for gain-clamped amplifiers. We present simulation results for the network blocking probability for each model, for different amplifier output saturation powers. And we also present simulation results for the distribution of optical powers at the input of each amplifier in the network. From our results we can conclude in which cases one can use a simpler model and in which other cases it is worth using a more elaborate model. We show that if the simplest and most common model is used for any network simulation, the obtained blocking probability is overestimated.     

Performance Evaluation of Service‐Aware Optical Transport System

We propose and experimentally demonstrate a service‐aware optical transport system. The proposed service‐aware optical transport system makes a flow based on service type and priority of traffic. The generated flow is mapped to a corresponding sub‐λ for transport over an optical network. Using sub‐λ provided by the centralized control plane, we could effectively provide quality‐of‐service guaranteed Ethernet service and best‐effort service simultaneously in a single link. The committed information rate (CIR) traffic and best‐effort traffic are assigned to different sub‐λs. The bandwidth of the CIR traffic is guaranteed without being affected by violation traffic because the bandwidth is managed per each sub‐λ. The failure detection time and restoration time from a link failure is measured to be about 60 µs and 22 ms, respectively, in the ring network. The measured restoration time is much smaller than the 50 ms industry requirement for real‐time services. The fast restoration time allows the proposed service‐aware optical transport system to offer high availability and reliability which is a requirement for transport networks.     

智能光网络的多域生存性技术研究

自动交换光网络是传送网的发展趋势,而快速高效的生存性是其重要特点.介绍了光网络生存性,重点分析了多域网络和域间路由问题,并且提出了具体的实现多域网络的生存性方法.     

Experimental validation of resource allocation in transport network slicing using the ADRENALINE testbed

Transport network virtualization provides the necessary data and control plane technologies as key enablers of future networks. The interaction between network slicing and optical transport network virtualization architectures is under study to automate effective network resource orchestration. In this paper, we present an harmonized network slicing and transport network virtualization architecture, including a network slice planner tool, which is designed and implemented enabling in-operation execution of network slice resource allocation algorithms. We validate the proposed architecture by providing a novel resource allocation algorithm, evaluating its performance and deploying two different slices on top of the ADRENALINE testbed, while measuring both slices key performance indicators.