OAM Technology of Packet Transport Network

The Packet Transport Network(PTN) technology includes Transport Multi-Protocol Label Switching(T-MPLS) and Provider Backbone Transport(PBT).T-MPLS is the simplified and reformed Multi-Protocol Label Switching(MPLS).It drops MPLS’connectionless features and its transport-unrelated forwarding processing,but adds the network model of the transport layer,protection switching and Operation,Administration and Maintenance(OAM) functionality.PBT enforces both OAM and protection functions,adds Time Division Multiplexing(TDM) business simulation and clock functions,and strengthens multi-service support capability.But PBT has no functions of traditional Ethernet address learning,address broadcast and Spanning Tree Protocol(STP).Both T-MPLS and PBT can well satisfy the requirements of packet transport.Compared to PBT,T-MPLS has better OAM functions.

Technology Development and Deployment Strategy of Carrier Ethernet

Carrier Ethernet(CE) is gradually stepping away from standardization and testing to deployment and application in live networks.Although great improvement has been made in the reliability of various CE technologies,there is need for improvement in their Quality of Service(QoS),Operation,Administration and Maintenance(OAM),especially the multi-vendor interoperability.The deployment of CE should be service-oriented,and the factors,such as maturity of related technologies and standards,deployment costs,and the complexity of network reconstruction as well as the interoperability with other vendors,should be taken into full consideration to flexibly select appropriate networking technology for different application scenarios according to technical features.

T-MPLS Technology and Application on Carrier Ethernet

As a connection-oriented packet transport technology,Transport Multi-Protocol Label Switching(T-MPLS) is an important bearer technology for Carrier Ethernet(CE).This article starts with the technological characteristics of T-MPLS,then goes on to the latest T-MPLS standardization progress and challenges,followed by the description of T-MPLS based CE architecture.Next,the article covers several key technologies related with T-MPLS,including the data forwarding plane,control plane,network survivability,and Operation,Administration and Maintenance(OAM).Finally,the article analyzes the applications of T-MPLS based CE.

Carrier Ethernet Services and Technologies

Carrier Ethernet(CE) services generally refer to the standardized carrier-class transfer services that feature in excellent scalability,reliability,manageability and Quality of Service(QoS) guarantee,and are offered by carriers to users based on Ethernet technologies.One of the important characteristics of CE service is the diversity of its implementation technologies.Enhanced Ethernet technologies consider scalability as their chief objective so as to extend conventional Ethernet bridge technologies;the latest Provider Backbone Bridge Traffic Engineering(PBB-TE) emerges as the technical trend of CE technology.Multi-Protocol Label Switch(MPLS) offers reliable Pseudowire(PW) connections for CE based on Label Switching Path(LSP).The convergence of MPLS and PBB is one of the important evolution trends for CE.Making full use of the existing Optical Transport Network(OTN) infrastructure,the optical ring network technology is the most cost-efficient and effective way to deliver CE services;its future development trend is characterized by enhancing the Operation,Administration and Maintenance(OAM) function and the control plane.

光层OAM关键技术研究

伴随着通信业务的高速发展,具有更大、更灵活、更低时延、更低功耗、更高集成度特点的光网络越来越被关注。网络的虚拟化、云化带来更多数据中心的部署,大容量的数据中心通过城域网互联对传送网在带宽、灵活性、安全、可运维等方面都提出了全新的要求。为保障光网络更高效的使用,现采用以波长标签技术为基础来研究光层OAM(Operation Administration and Maintenance)。光层OAM的实现将提供光层性能参数监测,重新优化,故障定位分析,业务路由的灵活调度,波道业务的高效可靠保护,优化和简化网络运维等重要功能。通过波长标签技术,可以对网络的光纤连接和故障定位提供高效直接的管理和排查,对各波长,功率对应的业务可实现在线监测和管理,对网络的灵活运维以及成本降低起到了巨大作用。

基于物体对称性实现旋转多普勒效应的优化测量

为了快速高效地测量对称物体的转速,基于数字螺旋成像理论,提出了一种测量旋转多普勒频移的优选方案.通过在空间光调制器上加载多重对称性物体的旋转光栅来模拟旋转物体.实验中通过测量三重对称物体和十重对称物体的反射谱,分析其频谱特性,验证了该方案可以快速高效地得到高信噪比的信号,进而测得转速,且测量误差在0.7%左右.该方法对测量具有多重对称性的物体的转速高效准确,有望应用在遥感技术领域,甚至在天文领域探测天体转速.

奇点光束复用光通信(特邀)

奇点光束包括基于相位奇点的轨道角动量(OAM)光束和基于偏振奇点的柱矢量光束(CVB)。OAM光束和CVB都具有正交性,可以作为空分复用的模式应用于光通信中,为光束复用提供一个新的自由度,大幅度地提高光通信系统的容量,在光通信中具有广泛的应用前景。文章首先介绍了OAM光束和CVB的数学描述和物理特性,然后重点综述了其产生和检测方法以及在自由空间光通信和光纤通信中的研究进展,比较了OAM光束和CVB在光通信应用中各自的优势与不足之处。最后,探讨了奇点光束复用光通信的应用方向和发展趋势。

基于电磁超表面的轨道角动量天线技术综述

电磁超表面是一种由亚波长电磁超材料单元周期性或非周期性排列构成的平面阵列结构,这种结构具有非常强大的空间电磁波调控能力,是天线领域的新兴研究方向。近年来,人们开始关注轨道角动量(OAM, Orbital Angular Momentum)在无线通信技术中的应用,以缓解频谱资源需求增长带来的压力。基于超表面构建的OAM无线通信系统具有设计简洁、灵巧轻便的特点,目前正是该领域的研究热点。本文主要就近期超表面OAM无线通信天线技术的研究进展,按照三个部分进行梳理总结。首先是OAM无线通信发展的简要介绍。其次是基于超表面的OAM无线通信天线关键技术研究进展综述,包括基于无源、有源超表面的涡旋波天线技术等。最后,本文对其今后的发展方向做出展望。

智能探针系统

智能探针系统以标准的Y.1731电信级OAM技术、标准的Y.1564以太网专线开通测量技术、MEF40标准开通模型为技术基础,结合互联网的思路,提供了向导式专线业务配置、基于WEB、APP的移动监控平台,实时监控网络的专线诸如时延、抖动、丢包等各类性能KPI的运营情况,探测性能故障,定位性能故障,降低Capex和Opex,提高客户体验,提升运营商专线品牌。

基于光载无线技术的毫米波轨道角动量多维联合调制/解调研究

提出了一种基于光载无线(ROF)技术的W波段涡旋毫米波生成及轨道角动量(OAM)多维联合调制/解调方法。采用ROF技术在光域对微波源进行倍频生成W波段光学毫米波,并通过集成光调制器对光学毫米波的相位和幅度进行调控。通过合理调控圆环天线阵列(CAAs)的辐射毫米波相移,从而实现涡旋毫米波的生成以及状态切换。同时,设计了64阶OAM、幅度和相位的三维联合调制格式,并通过模拟仿真,成功实现了75Gbit/s高阶联合调制信号的调制/解调。研究结果表明,OAM作为一个新的物理维度不仅可以通过复用来实现传输容量密度的提升,同时也可以作为调制手段实现传输容量的提升,在提高无线频谱效率以及保密通信中具有重要的潜在应用价值。

PTN关键技术及发展应用

PTN技术是业务向ALL IP转型对承载网的需求,首先介绍了PTN技术的概念及特点,其次重点研究了PTN中的关键技术,最后提出了PTN技术的发展应用方向。