城域粗波分复用技术的应用分析

本文是从城域光网络的网络结构和技术特点以及业务市场的基础上,对粗波分复用技术进行详细的分析,对粗波分复用技术在城域光网络中的应用进行了分析。     

FBG传感网络技术研究

系统分析和总结了现有 FBG传感技术的复用结构和系统性能 ,并依据复用方式的频域、时域和空间特性 ,从网络拓扑结构的角度 ,提出把 FBG传感网络划分为波分复用网络、时分复用网络、空分复用网络、频分复用网络和混合复用网络 ,在此基础上比较了各种复用方式的优缺点 ,并针对网络实用化开发提出了自己的观点 ,从而为 FBO传感网络拓扑结构及性能的研究提供了参考。     

OA&M framework for multiwavelength photonic transport networks

Photonic networks based on wavelength division multiplexing (WDM) and optical path technologies are expected to realize flexible, transparent, and cost-effective transport networks with a large transmission capacity. This paper explores the design framework of photonic transport networks taking into consideration the operation administration and maintenance (OA&M) functions required for the successful introduction of WDM systems based on the optical path concept. From the view point of network maintenance, clear distinction is made between the optical path layer and the optical section layer to facilitate accurate and smooth failure localization. The digital multiplexing span between physical multiplexing interfaces at the end-to-end digital nodes should have the same maintenance span as the corresponding optical path. We argue that cooperative maintenance by OA&M functions at both the digital and optical layers can be a practical way of network supervision. A supervisory (SV) signal transfer method and a configuration that is suitable for the terrestrial trunk network are also indicated. As an example, a practical SV system design methodology and an actual procedure developed for a single channel optical transmission system based on optical in-line amplifiers are introduced. Furthermore, application of the developed SV system and network restoration schemes is discussed for future WDM-based photonic networks. The OA&M aspects introduced will be valuable for creating future photonic network systems     

An optical infrastructure for future telecommunications networks

For the transport of the increasing traffic volume caused by existing and new narrowband services and evolving broadband services, the enhancement of the existing public telecommunication transport network is necessary. For this purpose an optical network layer with cross-connect and add/drop functionalities will be added to the existing transport network. A comparative analysis of space, time, and optical frequency division multiplexing has shown that for the time being optical frequency multiplexing is best suited for the realization of that new network layer. This multiplexing scheme offers the greatest advantages such as very high bandwidth utilization in the fiber and simple and efficient cross-connecting of high bitrate streams. In the near future, technology will be mature enough for the realization of a demonstrator network based on optical frequency division multiplexing. The functionalities of the optical network are evaluated and the results clearly show that optical frequency conversion and regeneration should be provided by the optical network. The article also deals with the realization aspects (cross-connecting, supervision, and operation and maintenance) of an optical node     

An architecture for IP over WDM using time-division switching

This paper proposes an architecture for routing Internet protocol (IP) packets directly on optical networks. The use of label switching is assumed in the IP routers, while a new routing architecture is introduced to transport IP packets across an optical backbone network. The architecture is based on a two-tier multiplexing approach with wavelength division multiplexing (WDM) addressing the number of regional exchanges and time-division switching communicating among the hubs. Such an architecture not only has the advantages of simple network management and high efficiency with low latency; it also is scalable by addition of regional exchanges, hubs, and fibers     

Factors affecting the design of optical FDM informationdistribution systems

Major factors affecting optical frequency division multiplexing (FDM) distribution system design are described. In particular, multiplexing/distribution configuration and channel-selection methods are compared from the viewpoint of the number of channels, the number of subscribers, and the transmission distance. The applicability of optical fiber amplifiers to the optical FDM information-distribution network is also discussed. The experimental results of a 5 GHz spaced 16-channel FDM distribution/transmission at 622 Mb/s, using a waveguide frequency-selection switch (tunable filter) and a multicarrier frequency-stabilization technique, are also discussed     

Architectures and technologies for high-speed optical data networks

Current optical networks are migrating to wavelength division multiplexing (WDM)-based fiber transport between traditional electronic multiplexers/demultiplexers, routers, and switches. Passive optical add-drop WDM networks have emerged but an optical data network that makes full use of the technologies of dynamic optical routing and switching exists only in experimental test-beds. This paper discusses architecture and technology issues for the design of high performance optical data networks with two classes of technologies, WDM and time division multiplexing (TDM). The WDM network architecture presented stresses WDM aware Internet protocol (IP), taking full advantage of optical reconfiguration, optical protection and restoration, traffic grooming to minimize electronics costs, and optical flow-switching for large transactions. Special attention is paid to the access network where innovative approaches to architecture may have a significant cost benefit. In the more distant future, ultrahigh-speed optical TDM networks, operating at single stream data rates of 100 Gb/s, may offer unique advantages over WDM networks. These advantages may include the ability to provide integrated services to high-end users, multiple quality-of-service (QoS) levels, and truly flexible bandwidth-on-demand. The paper gives an overview of an ultrahigh-speed TDM network architecture and describes recent key technology developments such as high-speed sources, switches, buffers, and rate converters     

Key building blocks for high-capacity WDM photonic transportnetworks

The objective of this paper is to give an overview of the different studies we have performed at the research level regarding the design and implementation of a photonic wavelength division multiplexing (WDM) layer providing transparent transport services to client layers (SONET/SDH, ATM, etc.). Such a network requires a number of enabling factors to be assessed in order to become a reality. Among these factors are the availability of high-capacity WDM transmission systems and efficient optical routing nodes based on mature technology, the design of robust networks optimizing the utilization of resources, and the development of a management system in accordance with presently applied standards for transport networks. We review our achievements in these different fields     

光通信网开始实际运用

首选对光通信网的涵义作一概述,然后较明确地说明以波分复用为基础的光通信网的具体内容,最后,介绍欧洲近年开始筹建泛欧波分复用光通信网实际运用的情况。     

Operation and maintenance for an all-optical transport network

For the enhancement of the existing electrical transport network a new one based on optical frequency division multiplexing (or wavelength division multiplexing) will be added to the existing one. This article focuses on the system/network supervision and operation and maintenance, which are of great importance for the success of the optical transport network. For a better understanding of these topics, it is necessary to derive a layered network model for the optical transport network and to make a workable definition of the term “network transparency.” The proposed operation and maintenance concept deals with the identification of its related functions, the supervision of the optical regenerators, the maintenance signals required for failure localization, and the difficulty of defining a suitable mechanism for performance monitoring in transparent networks. Appropriate realization aspects are discussed too. Possible solutions for failure detectors are described. For transferring the individual maintenance signals between the associated network elements, a communication channel with a suitable structure is proposed     

Coherent passive optical network for 5G and beyond transport

Building low-latency and high-capacity optical networks is vital for new high-speed cellular technologies. Coherent wavelength division multiplexing passive optical networks (WDM-PONs) are expected to play a key role in these applications. In this article, an overview of PON technologies for the 5th generation (5G) transport systems has been given. Moreover, a modified scheme based on coherent WDM-PON has been investigated using a dual polarization quadrature phase shift keying (DP-QPSK) transceiver. The aim of the scheme is to build a 1 600 Gbit/s network that will be used in the construction of the transport architecture of 5G and beyond cellular networks either in mobile front haul (MFH) or mobile back haul (MBH). The results indicate that the proposed scheme offers a promising solution for future 5G transport systems.     

光传送网(OTN)技术应用阐述

光传送网(Optical Transport Network, OTN)是一种基于波分复用技术(WDM),在光层上组织成网的传送网。其因具有可靠性高、容量大等优点而被广泛应用于各种通信业务中,目前已经形成包括SDH, PTT, ATM, MSTP, IPRAN在内的多种传输体制并存的局面。文中首先简要阐述了OTN技术概念及ROADM技术、OTN技术概念及其作用,然后简要阐述了OTN网络技术及其在我国省际网省、内部网和城域网建设中的典型应用实例、光传输网的特性,即其复用原理和映射复用原理,最后简要地阐述了OTN光传输网应用。     

Optical FDM transmission technique

This paper surveys the present state of optical frequency-division multiplexing (optical FDM) technologies. Utilizing a broad optical frequency bandwidth up to several hundred terahertz, optical FDM is expected to find applications in large-capacity trunking and local distribution networks. The present state of the related technologies and the future prospects for these applications are discussed.     

New advances on optical components needed for FDM optical networks

Two critical components, needed for optical networks based on frequency division multiplexing (FDM) and frequency reuse technologies, are presented. One is a fast tunable laser, yielding 24 discrete frequencies regularly spaced by 40 GHz around 1.53 μm. The laser can be switched randomly in less than 8 ns among these frequencies. Frequency routing of a 3-Gb/s bit stream in 10-ns packets between ten different destinations has been demonstrated with this laser. The second component is a broadband wavelength shifter capable of switching multigigabit data between optical frequencies in the 1.5-μm region. The device is tunable and cascadable, provides conversion gain, and is nearly polarization insensitive. Data degradation after wavelength shifting is negligible. Such a device provides the means of reusing the limited set of frequencies given by the lasers and thus of realizing large size networks     

光网络技术的发展与应用

主要从TDM（时分复用）、WDM（波分复用）、光纤技术、节点技术及全光网络等方面的发展介绍了近阶段光网络技术的发展与应用。     

On the future of wavelength routing networks

This article discusses the possible applications for optical networks based on wavelength division multiplexing and how they compete and complement current high-speed networks (SONET, ATM). We first outline the best-case scenario for this technology and describe the spectrum of proposed optical networks (WDM links, passive optical access networks, broadcast-and-select networks, and wavelength routing networks). Then we focus on wavelength routing networks and describe their advantages and disadvantages relative to other competing alternatives for very-high-speed networks. Finally, we analyze the different markets for such networks in the telco and data communications arena     

WDM光网络中的业务量疏导

波分复用（WDM）技术在主干传送网中巳广泛应用，WDM光网络的研究进展也非常迅速，光网络中的业务量疏导定义为复用、解复用和交换低速率业务流到大容量的光路中的行为。介绍了WDM光网络的业务量疏导的重要性，研究方法及其最新研究进展情况。     

密集波分多路在组建通信网中的应用

首先说明通信设施使用多路技术的发展进程，从过去的频分多路（FDM）至数字的时分多路＊TDM）到最近的波分多路（WDM），接着，叙述WDM在光纤传输线路中的应用，对加大传输容量非常有效，最后，解释WDM在光核心网中的应用，以期扩大通信网容量，适应快速增长的通信业务量的需要。     

Transmission capacity of optical path overhead transfer schemeusing pilot tone for optical path network

Photonic networks based on the optical path concept and wavelength division multiplexing (WDM) technology require unique operation, administration, and maintenance (OAM) functions. In order to realize the required OAM functions, the optical path network must support an effective management information transfer method. The method that superimposes a pilot tone on the optical signal appears very interesting for optical path overhead transfer. The pilot tone transmission capacity is determined by the carrier to noise ratio which depends on the power spectral density of the optical signal. The pilot tone transmission capacity of an optical path network employing WDM technology is elucidated; 4.5 kb/s transmission can be realized when the pilot tone modulation index is set at 3%