PON技术及其应用模式

PON技术分析PON技术已经成为业界公认的实现FTTH的首选方案。PON系统由局端设备(OLT)、用户端设备(ONU／ONT)和光分配网(ODN)组成。所谓“无源”,是指ODN全部由无源光分路器和光纤等无源光器件组成,不包括任何有源器件。PON技术采用点到多点拓扑结构,下行和上行分别通过TDM和TDMA方式传输数据。     

一种融合EPON和GPON的接入方案

无源光网络(PON)突破了传统的点到点解决方法的局限,一直被认为是光接入网中最具发展前景的技术.由于光接入网应用环境复杂多样,PON应用技术也呈现出多样化的特点.以太网无源光网络(EPON)和千兆无源光网络(GPON)是其中两种具有代表性的接入技术.文章根据光纤到户实际工程的需要,论述了一种融合EPON和GPON技术的接入方案.     

PON应用及运营考虑

一、xPON接入技术介绍 无源光网络(PON)技术是一种点到多点的光纤接入技术,它由局侧的OLT(光线路终端)、用户侧的ONU(光网络单元)以及ODN(光分配网络)组成.     

基于集成节点的PON与OBS网络互连技术研究

无源光网络(PON)与光突发交换(OBS)网的互连是光分组传送网络发展的必然.文章分析了PON与OBS网互连存在的主要问题及已有的解决方案,提出一种聚合PON与OBS边缘节点功能的集成节点结构,研究基于集成节点的PON与0BS网络互连技术方案,提出基于业务流量的三级汇聚机制,分析结果表明三级汇聚机制可以保证业务等级,减少业务延时.     

一种跨OLT的PON保护技术

目前已经实现的无源光网络(PON)保护方案通常保护的是光线路终端(OLT)的PON媒体接入控制器(MAC)到光网络单元(ONU)的PON MAC之间的光路,无法对OLT整体设备进行保护.文章介绍了一种跨OLT的PON保护方案:ONU同时在两台OLT上注册,两台OLT之间通过传输控制协议(TCP)方式使配置和状态等信息周...     

无源光网络PON中光网络单元ONT的应用方案

随着光纤接入网(统称FTTx)的大热,无源光网络PON技术越来越受到人们的关注,本文首先简单介绍了PON技术的发展历史和现状,接着介绍了基于上海贝岭的PON芯片:BL1908和BL1920设计的一种千兆位无源光纤网络GPON中的光收发模块ONT应用方案。     

一种改进的PON保护组解决方案

无源光网络(PON)无疑是下一代接入网的一种主流方案。由于该技术一般采用点到多点(P2MP)的树形拓扑结构,因此从局端设备OLT的PON MAC到ONU的PON MAC之间的链路可靠性就显得极为重要。文章提供了一种快速、稳定、成本低、易扩展且与PON系统其他软件模块兼容的光纤保护倒换的整体方案。     

三种宽带无源光接入网技术比较

无源光网络(PON)是一种新兴的覆盖最后一公里的宽带光纤接入技术.随着PON的发展,应用于PON的技术也层出不穷,基于ATM的无源光网络(APON)/宽带无源光网络(BPON)、以太网无源光网络(EPON)以及最近出现的千兆以太网无源光网络(GPON)技术都进一步推动了宽带光接入网的发展.文章回顾了宽带PON技术的发展,介绍了3种宽带PON技术,并对它们进行了比较和分析.     

六大技术优势助力EPON发展

技术优势 EPON(以太无源光网络)是一种新型的光纤接入网技术,它采用点到多点结构和无源光纤传输,在以太网之上提供多种业务.PON的本质特征是光分配网络(ODN)全部由无源光器件组成,由于取消了局端与客户端之间的有源设备,PON能避免外部设备的电磁干扰和雷电影响,减少了线路和外部设备的故障率,提高了系统可靠性,同时也节约了维护成本,是电信维护部门长期期待的技术.     

EPON技术及应用设想

PON（无源光网络）在解决宽带接入问题上是一种经济的、面向未来多业务的用户接入技术。作为光纤接入领域最引人注目的技术,只有适合末端光纤接入的业务和网络发展趋势,才能有机会取得真正的商业成功。因为PON作为一种点对多点的技术方案和产品,     

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     

OTDR in single-mode fibre at 1.55 ?m using a semiconductor laser and PINFET receiver

Optical time domain reflectometry (OTDR) at a wavelength of 1.55 ?m using a semiconductor laser source is reported for the first time. The apparatus uses a PINFET optical receiver and can detect the Rayleigh scatter signal over 30 km of single-mode fibre installed in duct.     

Evolution of Terrestrial Optical System and Core Network Architecture

Optical systems and technologies have been radically changing the telecommunication networks for past 15 years; today wavelength division multiplexing (WDM) technology, optical amplifiers, and simple optical switching elements like optical add-drop multiplexers (OADMs) are used in the backbone networks of all operators worldwide. Optical systems nowadays provide the basis for cost-effective transmission of large amounts of bandwidth over the Internet, and will enable its future growth and the spreading of new applications and services. This paper summarizes the main trends in optical networking and investigates potential future application areas. Optical system technology has become so pervasive in network design that it needs to be considered in the context of provisioning new applications and services. Therefore, the analysis is not limited to the aspects of physical transmission, but also takes into account recent developments in integrated network design as well as network control and management. The following sections describe the key functionalities of future optical network architectures, and the key findings of the theoretical analysis are supported by the results of a field trial of advanced transmission technology.     

具有反馈式光缓存的OPS节点结构性能研究

对反馈式光分组交换节点的性能进行深入分析,并针对现有反馈式光分组交换节点结构的不足,提出一种改进的反馈式光分组交换节点结构,即SMOP-TWC交换结构.最后,本文使用仿真实验的方法对SMOP-TWC交换结构的性能进行深入研究.     

Optical switching technology comparison: optical MEMS vs. other technologies

Optical switching technologies are very crucial to future mobile broadband all-optical IP networks. Many different optical switching technologies are currently available or under development. The main purpose of the article is to conduct performance comparisons on optical switching technologies in terms of basic performance, network requirements, and system requirements based on a literature survey. The technologies include switching based on optical microelectromechanical systems (MEMS), thermal optical switching, electro-optic switching, and acousto-optic switching technologies. Each optical switching technology has unique performance characteristics specific to the utilized optical phenomena. It might be crucial to integrate some technologies together to achieve a better solution for optical switching. Optical switching is a very hot topic attracting much research effort. Optical MEMS-based switching technology might be one of the most promising approaches at present. Many new optical switching technologies might be created in the near future. Through the impact of nanotechnology, some innovative approaches to optical switching might emerge.     

光交叉连接用三维MEMS技术

随着密集波分复用[Density Wavelength Division Multiplexing(DWDM)]技术的迅速发展,在高速光传送网中,光交换设备逐渐成为限制网络通信速度的瓶颈,而基于微电子机械系统[Micro-Electro-Mechanical Systems(MEMS)]技术的光交叉连接设备被认为是未来高速光网络中节点设备的首选.本文对MEMS的光交叉连接结构进行了介绍,并对三维MEMS的光交叉连接结构的部分性能进行了研究和分析,最后讨论了基于三维MEMS结构的光分插复用器在全光通信网中的应用.     

峰峰矿区HFC网络改造方案——从1 310 nm到1 550 nm全光网络传输技术方案

针对峰峰矿区已拥有的1310 nm光网络存在的故障多、可靠性差、管理维护难等问题,讨论了采用1550 nm EDFA光传输替代1310 nm光传输模式的优势,介绍峰峰矿区1550 nm全光网络的设计思路和技术方案,该方案使以上问题得以解决。     

Long-term monitoring of polarization-mode dispersion of aerial optical cables with respect to line availability

Physical and technical limits become important when trying to increase data transfer rates to tens of gigabits and higher for already installed optical cables. Polarization-mode dispersion (PMD) is one of the crucial transmission constraints, especially for aerial cables exposed to environmental stresses. Optical fibers in the laboratory and three aerial optical fiber cable links across the Swiss alps were characterized with respect to PMD. Long-term measurement results are correlated to weather data along the cables, and predictions regarding line availability are made.     

时隙光突发交换网络阻塞性能分析模型

文章介绍了基于时隙的光突发交换网络的结构及其特点，提出了相应的时隙化多波长多光纤系统阻塞分析模型，仿真结果表明该模型准确地反映了光纤数和帧长等网络参数变化对网络阻塞特性的影响．对于评估时隙突发交换网络性能和设计实现参数具有重要意义。     

光开关矩阵技术及其应用研究

光开关矩阵是智能光交叉连接设备和可重构光分插复用器核心技术,是构建自动交换光网络的基础.文章介绍了大规模商用的光开关矩阵的关键技术及其进展,详细分析了光开关矩阵在自动交换光网络中的应用.