以太无源光网络中光分配网的优化设计

提供了一种兼容光纤CATV网的以太无源光网络(EPON)的光分配网(ODN)设计方法,采用两级光网结构提高了系统设计的灵活性,并给出了光分路器的设计公式;提供了一种冗余环行干线和冗余分支结合进行ODN冗余保护的方法,能极大地提高EPON网络的可靠性。     

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.     

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.     

基于千兆以太网的无源光网络技术研究

基于千兆以太网的无源光网络(EPON)将有可能取代基于ATM的无源光网络(APON),成为解决接入网瓶颈的最佳途径。文章从EPON引入的原因着手,对EPON系统组成、分层结构和实现EPON系统的关键技术作了较详细的探讨,同时对EPON的下一步发展作了展望。     

PON发展现状及思考

无源光网络(PON)是近几年兴起的新技术,包括ATM无源光网络(APON)、以太无源光网络(EPON)和千兆无源光网络(GPON).指出了它们的关键技术和系统特点,并进行了详细比较.同时,介绍了PON技术的发展现状,并对PON的未来发展提出了建议.     

FTTH两大实现方式：EPON和GPON

无源光网络(PON)是实现FTTH的主流方式,其中,基于ATM的宽带无源光网络(BPON)由于种种因素不宜采用。本文分析比较了以太网无源光网络(EPON)和吉比特无源光网络(GPON)的关键技术,并介绍了这两种宽带PON技术的设备互通性和产品进展情况。     

EPON专用芯片设计

文章介绍了集成化设计以太网无源光网络(EPON)产品中传输汇聚(TC)子层芯片的结构设计框图,详细介绍了光线路终端(OLT)和光网络单元(ONU)的TC子层芯片设计.在此结构框架下,对EPON系统性能进行了仿真,发现在相同业务负载的情况下,EPON系统业务延迟小于以ATM为基础的无源光网络(ATM PON)系统中的相应延迟.     

EPON技术在青海电网的应用

无源光网络(PON)技术越来越受到人们的关注,PON是一种单纤双向的点到多点(P2MP)结构的无源光网络,EPON具备了以太网和PON的优点,由光线路终端OLT(Optical Line Terminal)、光网络单元ONU(Optical Network Unit)和无源分光器POS(Passive Optical Splitter)组成。介绍了EPON技术的主要优缺点,并与其他通信技术进行了比较,概述了EPON的系统结构,以及EPON技术在青海电力网中的应用,展示了EPON技术广泛应用的美好前景。     

EPON光纤保护倒换的研究

以太网无源光网络(EPON)正在不断进步与发展,在实际生活中的运用范围也在不断扩大,而关于它的保护方式也随之成为重点关注对象之一.介绍了EPON的光纤保护倒换机制的4种类型及其保护倒换的方式、当前各种保护倒换类型的发展和研究近况.详细说明了当前类型b保护的最新发展,1:N保护方式的实现方法和目前需要解决的问题.     

xPON系统中用户侧端口成环的破除方法

在以太网无源光网络/吉比特无源光网络(EPON/GPON)系统中,光网络单元(ONU)用户端口成环将会造成同一个无源光网络(PON)口下所有的业务中断.文章首先分析了EPON/GPON系统中造成ONU用户端口成环的常见原因以及成环后所带来的严重后果,然后列出了5种可以破除用户侧端口环路的方法,并在此基础上提出了采用"特...     

Bandwidth-efficient PON system for broad-band access and local customer Internetworking

We present a new passive optical network (PON) architecture for broad-band access and local customer networking. It provides high bandwidth efficiency for delivering both PON and customer internetworking services. The architecture separates the local optical network from the PON system, thereby enhancing security, flexibility, and allowing the use of any media access control protocol. The local customer internetworking feature is demonstrated with insignificant penalty to the overall PON system performance.     

构建NGB多业务PON融合网络

根据广电运营商业务发展的需要,结合天威视讯网络现状,提出了适合广电行业的多业务融合无源光网络架构.由于PON技术在广电接入网方面具有突出的优势,在现有网络上构建满足多业务要求的融合PON网络将影响深远.介绍了多接入方式并存的PON融合网络架构.最后,分析如何在融合PON网络平台开展基础业务、增值业务和ICT业务.为广大广电运营商推进光网的双向改造提供了参考.     

PON接入技术在城域网中的应用定位

光接入是宽带接入的发展方向,无源光网络(PON)是实现光纤到户(FTTH)的首选方案.本文首先分析了城域网概念的引入对接入网发展的影响和PON接入网的原理特点,指出PON拓扑结构完全符合城域网边缘的业务汇聚和接入模式,符合城域网概念引入后的用户业务引入段和接入层的结构特点,最后给出了PON技术与MSTP(多业务传送平台)结合构建多业务城域网的策略和PON技术在移动网络中的应用定位.     

Union-PON,全业务光纤接入解决方案

从Union-PON的网络结构、共存波分复用器、承载无线BBU-RRU间业务的WDM-PON模块等3个方面介绍了Union-PON的关键技术,并通过测试结果说明了Union-PON系统中的TDM-PON和WDM-PON在共存情况下互无干扰。     

PON管理关键技术问题浅析

面向三重播放业务的需求,构建新一代的网络管理架构、优化IT系统和维护体系是当前运营商PON建设和维护的重点和难点.本文面向PON,尤其是FTTH规模发展情况下的运维能力提升,探讨了PON管理中的一系列关键技术问题,包括PON EMS管理、北向接口及网管流程以及省级集中管理平台功能要求等.     

无源光网络冗余保护及应用实现

PON网络相对于传统网络组网简单,无源传输,提供可观接入速率和多业务应用,得到了蓬勃发展。通过对PON网络组网结构以及业务特征的定性研究,分析了PON网络中不同保护方式对应的应用场景。并对在网络设计中考虑保护以及在组网各个节点进行冗余保护以及提升网络运行稳定性,提高用户体验感知的有效方法进行了总结。并对特殊应用下的PON网络结合和冗余保护实现进行分析总结。     

Architecture of multi-OLT PON systems and its bandwidth allocation algorithms

In this paper, we propose a novel passive optical network (PON) architecture that has multiple optical line terminals (OLTs). Unlike existing PONs where all ONUs are connected to a single OLT, the proposed multi-OLT PON allows subscribers to choose their own service providers from among multiple OLTs. Service companies and subscribers can make service level agreements (SLA) on the amount of bandwidth that each OLT or ONU requires. A new control protocol and bandwidth allocation algorithms appropriate in this new PON environments are suggested. For the downstream, a scheme to share the bandwidth among multiple OLTs is studied to maximize the total transmitted packets while guaranteeing each OLT’s SLA. A modified Limited Dynamic Bandwidth Allocation named mLimited scheme is also proposed for upstream transmission toward multiple OLTs, which maximizes the total upstream throughput while minimizing the delay of each ONU. Performances of the proposed PON architecture and algorithms are analyzed. A PON system with two OLTs and 16 ONUs is used in the analysis. Self-similar traffic reflecting current packet distribution is used in the packet generation. The results show that the proposed DBA schemes efficiently manage bandwidth even when the occurred traffic load is quite different from the reserved bandwidth. It is found that the proposed PON architecture is appropriate in supporting diverse services in future high-speed optical access network.     

Experimental demonstration of remote unified control for OpenFlow-based software-defined optical access networks

Passive optical network (PON) has attracted much attention by the emergence of high-bitrate video-centric applications over the Internet in the access side. In the current commercial PON, the configuration of optical line termination equipment is needed to modify through network management system manually and periodically in the local areas. The traffic flow of different users lacks dynamic control and intelligent schedule. In this paper, we propose and implement a novel software-defined optical access network (SDOAN) architecture for remote unified control based on OpenFlow-enabled PON. Based on the proposed architecture, a service-aware flow scheduling strategy is introduced to flexibly and efficiently allocate the network bandwidth resources and detect the status of network flows in real time. The SDOAN can enhance the resource utilization and QoS guarantee of each user effectively through unified control manner, and reduce the operating expense by remote interaction and operation. We have designed and verified experimentally SDOAN on our test bed with OpenFlow-enabled OLTs. The overall feasibility and efficiency of the proposed architecture are also experimentally demonstrated and compared with interleaved polling with adaptive cycle time strategy in terms of resource occupation rate and average delay.     

基于WDM技术的宽带无源光网络

为了进一步满足接入网增加带宽的需求,同时考虑到WDM器件的局限性,提出了一种基于WDM与现行的功率分束无源光网络（PS－PON）技术的新型光纤接入网络结构,并设计了IP数据报在PON中传送具体优化实施方案。     

Low‐Cost,Low‐Power,High‐Capacity 3R OEO‐Type Reach Extender for a Long‐Reach TDMA‐PON

This paper proposes a low‐cost, low‐power, and high‐capacity optical‐electrical‐optical‐type reach extender that can provide 3R frame regeneration and remote management to increase the reach and split ratio with no change to a legacy time division multiple access passive optical network. To provide remote management, the extender gathers information regarding optical transceivers and link status per port and then transmits to a service provider using a simple network management protocol agent. The extender can also apply to an Ethernet passive optical network (E‐PON) or a gigabit‐capable PON (G‐PON) by remote control. In a G‐PON, in particular, it can provide burst mode signal retiming and burst‐to‐continuous mode conversion at the upstream path through a G‐PON transmission convergence frame adaptor. Our proposed reach extender is based on the quad‐port architecture for cost‐effective design and can accommodate both the physical reach of 60 km and the 512 split ratios in a G‐PON and the physical reach of 80 km and the 256 split ratios in an E‐PON.