超长距离光传输技术在网络中的应用

超长距离光传输技术的研究已经开展多年，相关的实验室测试和现场试验已经证明了超长距光传输的可行性。超长距光传输中所应用的相关技术，已从实验室进入到市场应用，我国也已经制定出版了超长距光传输相关的通信行业标准。在市场需求的推动作用下，构架一个高性能、低成本的基础光网络逐渐成为运营商考虑的重点。     

超长距离全光传输技术

超长距离全光传输是光通信发展的目标之一,文章介绍了几种超长距离全光传输方案,例如：拉曼放大技术、光孤子传输技术、全谱WDM（Full-spectrum WDM）技术,对它们优缺点进行了比较全面的分析和比较。     

超长距离无中继微波光子链路传输的探讨

文章建立了采用外调制方式的超长距离无中继微波光传输链路的理论模型,分析了超长距离无中继微波光子链路传输系统在工程设计中需要考虑和解决的问题及其实现方案,论述了超长距离无中继微波光传输方案的应用模型及各种设备在系统中所起的作用。     

浅析超长距离无中继光传输技术与应用

在电力系统中,数字化智能新颖的技术正被采纳并推广,从根本入手促进了传输的改进。有些传输设定了超长的传输距离,这时的光传输就应配备最佳的途径及方式。从现状看,光纤通信配备了调控性的计算机、中继器及相应的转换器,在超长传输范围内的这些构件都有着必备的价值。无中继特征的光传输相比拥有更高水准的传输性能,可用作距离超长状态下的传输。对于此,解析了传输技术现存的应用状态;结合光传输的真实情形,选取最合适的技术手段。     

MSTP超长距应用场景分析及解决方案

分析了单跨段超长距离传输应用场景,介绍了限制光传输距离的3个主要因素,最后给出了MSTP系统单跨段超长距离传输解决方案。     

超长距光传输技术三峡金沙江下游光传输网的应用

针对金沙江下游二期光环网因地貌环境等因素无法采用中继站的方式实验远距离光传输问题,文章通过对超长距光传输技术中光接口类型、功放BA、PA、拉曼等技术的研究分析,并结合二期光环网各站点距离的统计,针对性地计算出每段站点间光衰耗和色散等参数;运用再生距离公式和色散容限公式给出光接口和放大器的最优组合方案;并通过对提出方案的光信号功率在传输线路上的损耗计算,最后给出金沙江下游光环网二期超长距站点的实际配置方案,总结出了不同光缆距离间的超长距设备配置。     

ULH技术及其标准

本文介绍超长距离(ULH)WDM光传输技术,并对与其相关的标准指标进行探讨.重点是OSNR和色散代价,提出ULH系统OSNR的要求为15dB,ULH系统也应考虑光通道代价指标,并主张可以放心使用Raman放大器.     

新一代光通信技术

光通信技术将从研究光纤的固有性质向研究光的性质,如载波(Carrier)方向发展。具体技术有:①超高速/超长距离传输技术;②光波通信技术;③光信号处理技术。实现超高速/超长距离传输技术将采用相干光传输技术,这样,接收灵敏度可提高十几dB,中继距离将达到100km。如采用光纤放大器,中继距离会增加到400km左右。在理论上,光纤放大器的中继距离为5000～10000km。目前,已制定其技术开发目标:①超高速电     

浅谈长距离光传输

随着网络信息化时代的到来,长距离光传输通信技术越来越重要,例如跨距之间没有光放或电3R再生中继站点、海底光缆、荒岛连接以及跨越恶劣地形的传输等等.目前.长距离传输系统在我国的干线网络上已经有大量的应用,论述了光网络长距离传输一些关键技术、超长距离光传输方案的应用模型及各种设备在系统中所起作用     

超长站距光传输技术及其在电力系统的应用

在科技不断发展的过程中,电力工程也已经发展成为人们生活中不可缺少的一项重要内容.电力工程随着科技而生,又在不断被运用到人们的生活与建设的过程中推动了科技的蓬勃发展.电力工程之中的技术理论众多,而作为其中之一的通信技术,也在现代电力工程的发展之中发挥着重要的作用.在电力通信的工程之中,超长站距光传输技术,也成为了远距离通信技术中的重要研究内容.从远距离光传输的应用现状出发,对超长站距光传输中的光放大技术、色散补偿技术以及光传输技术的应用进行了研究.     

烽火长途传输解决方案

介绍了烽火通信针对长途骨干网长距离、超大容量、智能化的发展趋势推出的FONST长途传输解决方案，包括方案的特点和组成等。     

Trends in long-wavelength single-mode transmission systems and demonstrations in japan

Long-wavelength single-mode optical fiber transmission technology has recently made rapid progress and is now moving into the commercial operation stage. This paper describes the present state of this technology focusing on the research and development work in the Electrical Communication Laboratories. Based on the results of experiments on optical devices and on preliminary system feasibility analysis, it is shown that, at the present time, an optical wavelength in the 1.3 μm band is desirable for large capacity transmission from the viewpoint of attainable repeater spacings. A field trial plan of a 400 Mbit/s optical transmission system for a long-haul trunk which can compete economically with existing digital transmission systems is outlined.     

Second-Generation Trunk Transmission Technology

Long-wavelength single-mode optical fiber transmission technology has recently made rapid progress and is now moving into the commercial operation stage. The introduction of high-speed single-mode systems to long-haul trunk transmission systems is quite attractive from the viewpoint of cost effectiveness and network digitalization. This paper describes the system requirements as well as the key technology for the systems with empasis on the transmission characteristics of high-speed single-mode systems.     

Optical phase conjugation for ultra long-haul phase-shift-keyed transmission

Nonlinear phase noise (Gordon-Mollenauer phase noise) can limit the transmission distance for phase-shift-keyed modulation formats. In this paper, the compensation of nonlinear phase noise by a midlink optical phase conjugation (OPC) is studied. A proof-of-principle experiment is presented showing an over 4-dB improvement in Q factor when OPC is employed in a differential phase-shift-keying (DPSK) system. Also, an ultra long-haul OPC-based differential quadrature phase-shift-keying (DQPSK) transmission experiment is studied to show the impact of self-phase modulation (SPM)-induced impairments, including nonlinear phase noise, in a transmission line. OPC results in a 44% increase in transmission distance when compared to a "conventional" transmission system using dispersion compensating fiber (DCF) for chromatic dispersion compensation.     

Study on New Concatenated Code in WDM Optical Transmission Systems

A new concatenated code of RS（255,239）＋BCH（2 040,1 930） code to he suitable for WDM optical transmission systems is proposed. The simulation resuhs show that this new concatenated code. compared with the RS（255,239）4-CSOC（k0/n0=6/7, J= 8） code in ITU-TG. 75.1, has a lower redundancy and better error-correction performance, furthermore, its net coding gain（NCG） is respectively 0. 46 dB, 0.43 dB morethanthatofRS（255,239）＋CSOC（k0/n0= 6/7, J= 8） code and BCH（3860,3824）＋BCH （2 040,1 930） code in ITU TG. 75. 1 at the third iteration for the bit error rate（BER） of 10^-12. Therefore, the new super forward error correction（Super-FEC） concatenated code can be better used in ultra long-haul, ultra large-capacity and ultra high-speed WDM optical communication systems.     

Optical amplifiers transform long-distance lightwavetelecommunications

Optical amplifiers and wavelength-multiplexing technology are transforming lightwave communications by providing cost-effective upgrades that will increase immensely the transmission capacity of long-distance telecommunications networks. A new generation of undersea cable systems using fiber optical amplifiers as repeaters has been developed for transoceanic applications, yielding a capacity almost ten times larger than conventional systems using opto-electronic regenerators. Terrestrial long-haul networks will benefit significantly from amplified wavelength-multiplexed transmission systems designed to access the large inherent bandwidth in the installed fiber. Successful deployment of these advanced systems requires a thorough understanding of optical amplifiers and the optical fiber medium, as their requirements interrelate through optical bandwidth, noise, dispersion, optical nonlinearities, and their impact on signal transmission. While the first commercial WDM amplified lightwave systems are deployed for point-to-point applications, optical transparency and wavelength multiplexing will be exploited for networking leading to the higher functionality and improved cost-effectiveness expected of photonic networks     

An overview of very high capacity transmission technology for NTT networks

This paper describes very high capacity optical transmission system technology, which is useful for long-haul trunk lines, and has led to the feasibility of NTT's first gigabit-per-second range transmission system. It also describes various devices and circuits, such as high performance lasers, photodetectors, very wide-band amplifiers, and high speed logic circuits required for the development of such systems. It then discusses future research areas and trends in advanced lightwave communication systems.     

直接检测光正交频分复用系统噪声分析

针对直接检测光正交频分复用（DDO-OFDM）系统产生的放大器自发辐射（ASE）拍频噪声。通过对系统受ASE噪声影响的数学分析得到噪声影响机理及系统信噪比表达式,根据理论推导提出载波抑制方案,通过数字仿真验证推导结果及方案可行性。理论分析和仿真结果表明,系统受ASE拍频噪声影响严重,合理选择带通滤波器带宽可有效降低噪声...     

10-Gb/s, 4-channel wavelength division multiplexing fibertransmission using semiconductor optical amplifier modules

A dense wavelength-division-multiplexing (WDM) transmission system with very-high-speed channels was investigated experimentally. A 10-Gb/s four-channel WDM optical transmission (total capacity of 40 Gb/s) over a 40-km dispersion-shifted fiber was achieved by using hybrid-integrated DFB-LD/driver modules for transmitters and two cascaded semiconductor optical amplifier (SOA) modules for receivers. The experiment confirmed that the SOA is applicable for WDM transmission systems with high bit rates because of its inherent wide bandwidth. The transmission capacity of 40 Gb/s, achieved using an intensity modulation/direct detection (IM/DD) scheme, is the highest ever reported. This technology will make possible ultralarge capacity (up to several-hundred gigabits per second) and long-haul transmission systems in the future