单信道EDFA在WDM城域网中的应用研究

通过研究单信道EDFA在多信道工作条件下的增益特性,指出合理设计单信道EDFA的结构参数,可使得EDF的增益平坦度达到最佳。设计了应用于WDM城域网中的单信道EDFA,降低了系统成本并保证了系统灵活性。     

WDM光网络与IPoverWDM组网方式

WDM技术的出现与发展是本世纪末光纤通信发展的一个重大突破,WDM技术利用单模光纤的宽带低损耗特性,采用多个波长作为信息载波信道,各信道在一根光纤内同时传输。与单信道系统相比,密集波分复用(DWDM)不仅极大地提高了网络系统的通信容量,充分利用了光纤的带宽,而且具有扩容的灵活性和路由选择的灵活性等诸多优点,应用前景十分广阔。因此近年来,世界各国对WDM技术都进行了重点研究,新技术和新设备层出不穷,相应的光网络组网形式也随之不断改变。     

中兴通讯长途骨干网波分保护方式分析

引言 近期，为顺应GE／2.5G／10G等大颗粒数据业务的传送需求，并降低网络建设成本，IP Over WDM技术已逐渐成为各运营商关注的新一轮焦点技术。由于IP Over WDM技术的发展导致SDH层边缘化，IP传输将极大地依赖于WDM层面的保护，因此，IP 0VER WDM的演进对波分骨干网层面保护技术的灵活性和安全性、保护资源利用率、     

WDM光传送网的设计与操作

综述一WDM光传送网的设计和操作问题，首先介绍了一些基本概念，然后给出了有关WDM光传送网的不同问题及其设计方法，最后描述了对WDM光传送网进行操作的一此算法。     

频谱分割WDM无源光网络中的损耗和串扰研究

提出了一种频谱分割WDM无源光网络（PON）的损耗和串扰模型，通过理论分析和数值计算，得到了损耗和串扰与光源带宽、复用器参数、信道数以及信道失配系数等系统参数的关系，对频谱分割WDM PON的设计具有一定的指导意义。     

WDM系统中继段工程设计方法

本文为WDM系统中继段设计提出了流程化设计方法，并将其内容分为传输站型设置、光放大器设置、系统传输指标和传输性能改善4个部分，分别对各部分涉及的内容和设计方法进行详细论述。     

OTU在WDM中的使用

OTU在WDM系统中占据重要地位，对其进行研究有可能优化WDM和SDH系统。本文介绍了OTU的概念，特点及其运用。     

国内首条100G WDM长途传输系统正式开通运行

由中讯邮电咨询设计有限公司（下称中讯院）承担设计的国内首条100G WDM长途传输系统--2012年中国联通长途传输网100G WDM系统实验网工程,于2013年7月31日正式开通运行,成为国内首个承载100 Gbit/s业务的长途传输WDM系统。     

中国运营商对下一代传送网的发展考虑

目前，光传送网的带宽不再是光网络发展的主要矛盾，设备的稳定性、多业务性，组网的灵活性，网络的智能性成为当前关注的焦点。未来WDM系统将主要围绕超大容量和超长距离传输展开，而OXC和OADM主要用于实现灵活、可靠的波长路由配置以及有效的网络管理。[编者按]     

100G WDM系统设计方法及其在试验网工程中的应用

在对100G WDM关键技术和设计特点分析的基础上,结合中国联通100G WDM系统试验网工程,提出了100G WDM系统在现网环境下的工程设计方法:对光纤类型分析、客户侧接口选择、极限传输能力验证以及网络保护方式等与工程建设相关的内容进行了总结说明,同时对系统指标要求给出了明确建议.     

The impact of optical amplifiers on long-distance lightwavetelecommunications

The potential of erbium-doped fiber amplifiers (EDFA) and wavelength-division multiplexing (WDM) technology for expanding transmission capacity in long-distance telecommunications is examined. Properties of EDFA are nearly ideal for application in lightwave long-haul transmission. Nonlinear effects in the transmission fiber and amplifier spontaneous emission noise limit the performance and therefore dictate the design of long-distance amplified systems, especially those employing WDM. The next-generation transoceanic system will use EDFA as repeaters, yielding a capacity almost ten times larger than what is available today. Multichannel WDM soliton transmission promises further substantial enhancement. Terrestrial long-haul networks will also benefit greatly from amplified WDM systems designed to mine the large inherent bandwidth in the embedded fiber. The ten- to fifty-fold capacity increase over present systems not only will provide for ample growth, but also will enable network operators to enhance operational flexibility and network functionality, and to facilitate a fast-recovery self-healing capability through cost-effective redundant routing     

Application, design, and evolution of WDM in GTS's pan-Europeantransport network

A pan-European transport network must cope with enormous traffic inflation by introducing appropriate network solutions. WDM technology is the solution adopted by GTS, driven by capacity requirements, infrastructure availability, flexibility, and cost. The deployment of this new technology presents specific technical issues, but more important, it lays the foundation of future optical networking. We describe the motives underlying the deployment of WDM technology in the long-haul and short-haul areas of GTS's operational transport network. Next, after presenting the use of WDM as the multiservice platform for SDH and IP overlay networks as well as native WDM services, we focus on the design of SDH-over-WDM and IP-over-WDM networks. Finally, we discuss future WDM networking and management requirements to better serve the needs of a pan-European carrier such as GTS     

40G WDM系统应用研究

结合运营商网络需求特点,通过对技术方案、设备和线路参数的分析,提出了40GWDM系统在长途传输网上的码型选择和色散管理建议,分析并提出了在WDM和路由器设备间40G互联接口采用OTU3信号格式的建议和长距离客户侧光接口的解决方案     

浅析CRZ码在大容量超长距WDM系统中的应用

针对大容量超长距WDM系统的发展趋势，介绍编码调制方式对其实现的重要性，并从多个角度分析采用CRZ调制格式的优势，探讨其应用前景。     

波分复用技术及其在通信中的应用

波分复用 ( WDM)技术以其优异特征成为对现有光纤传输系统进行扩容、升级改造及建设新的高速、大容量通信网络的优选技术方案。文中阐述了它的主要技术特点 ,着重论述了它在通信领域中的应用 :长途通信干线传输、区域网、接入网等 ,并对 WDM技术的未来发展和应用进行了分析与展望。     

UK Core Transmission Network for the New Millennium

The capacity of the BT/UK core transport network is being increased by more than 100% per year to support the growing demands from IP/ATM broadband data services and the traditional private services platform. At the same time, unit costs are reducing significantly by the introduction of new SDH/WDM technology within both long-haul and city networks. These changes are described, together with the associated developments in network management, which will enable fast bandwidth provisioning and improved network resilience.     

Performance Comparison of Duobinary Formats for 40-Gb/s and Mixed 10/40-Gb/s Long-Haul WDM Transmission on SSMF and LEAF Fibers

Duobinary formats are today considered as being one of the most promising cost-effective solutions for the deployment of 40-Gb/s technology on existing 10-Gb/s WDM long-haul transmission infrastructures. Various methods for generating duobinary formats have been developed in the past few years but to our knowledge their respective performances for 40-Gb/s WDM transmission have never been really compared. In this paper, we made an extensive numerical evaluation of the robustness of these different types of duobinary transmitter to accumulation of ASE noise, chromatic dispersion, PMD but also to single-channel and WDM 40-Gb/s transmission impairments on standard single-mode fiber. A numerical evaluation of the ability of duobinary format for mixed 10/40-Gb/s WDM long-haul transmission with 50-GHz channel spacing is also led, on both standard single-mode and LEAF fibers, and compared to DQPSK format. In order to clearly identify the limiting transmission effects on each of these two fiber types, the assessment of the performance of a 50-GHz spaced WDM 40-Gb/s long-haul transmission using either duobinary or DQPSK channels only is implemented at last.      

Design Considerations for Transmission Systems in Optical Metropolitan Networks

Wavelength division multiplexing (WDM) has become a key technology in optical long-haul communications and wide area networks. Recently, interest in introducing WDM into metropolitan networks has increased. We look at some issues pertinent to the design of WDM transmission systems deploying optical add/drop multiplexers in these networks. In particular, we investigate the interaction of node-induced crosstalk with fiber nonlinearities in metropolitan ring networks. Two transmission systems are considered; namely a system of nonzero dispersion shifted fiber operating in the anomalous dispersion regime and another one of single mode fiber with post dispersion compensation. Data rate is assumed to be 10 Gb/s per wavelength. The dependence of the crosstalk/nonlinearity interaction and its system penalty on the frequency difference between signal and crosstalk carriers, input signal power, extinction ratio, number of nodes, and physical span of the network is examined in detail. It is shown that node-induced crosstalk can interact with fiber nonlinearities and introduce limitations on transmission performance. This interaction should therefore be taken into consideration in designing regional metropolitan networks.     

Wavelength division multiplexing in long-haul transoceanic transmission systems

Wavelength division multiplexing (WDM) technology used in long-haul transmission systems has steadily progressed over the past few years. Newly installed state-of-the-art transoceanic systems now have terabit per second maximum capacity, while being flexible enough to have an initial deployed capacity at a fraction of the maximum. The steady capacity growth of these long-haul fiber-optic cable systems has resulted from many improvements in WDM transmission techniques and an increased understanding of WDM optical propagation. Important strides have been made in areas of dispersion management, gain equalization, modulation formats, and error-correcting codes that have made possible the demonstration of capacities approaching 4 Tb/s over transoceanic distances in laboratory experiments.     

WDM field trials of 43-Gb/s/channel transport system for optical transport network

This paper describes recent technical challenges and the progress toward the realization of the optical transport network (OTN) based on 43 Gb/s channel. We describe the new digital frame format "OTU3: Optical Channel Transport Unit 3," which is standardized in ITU-T for OTN, for the enhancement of the network management capability in the OTN based on 43-Gb/s channels. We first proposed 43-Gb/s/ch dense wavelength-division multiplexing (DWDM) dispersion-managed transmission system using carrier-suppressed return-to-zero (CS-RZ) format that has several attractive features; it advances the evolution of OTN into 100 GHz-spaced long-haul DWDM transport networks. The first wavelength-division multiplexing (WDM) field trials confirmed the superiority of CS-RZ format in the DWDM transmission performance for the first time. The first 1 Tb/s (25 /spl times/ 43 Gb/s) WDM field trial confirmed the excellent network management capability of OTU3 in future data-centric OTN using the newly developed 43-Gb/s OTN line-terminal prototype.