城域WDM环网及其应用

文章阐述了城域WDM环网的节点结构，保护方式，波长转换器，子速率复用和光网络管理等，给出了WDM环网在城域应用时应考虑的一些因素，并分析了运营商所关心的系统成本问题。     

城域WDM光传送网——2纤OADM环网技术概要

本阐述了一种城域WDM传送网-2纤OADM环网的主要技术，如OADM环网节点的3种基本结构、环网的保护方式、波长转换器、子速率复用和城域光网络管理等，给出了OADM环网在城域应用时应考虑的一些因素，并分析了运营商所关心的系统成本问题。     

城域光传送网的建设与发展

结合城域网的基本概念,介绍了城域光传送网的三种主要技术:城域WDM环网、以SDH为基础的多业务传送平台、弹性分组环(RPR),阐述了城域网的建设和发展方向.     

城域光传送网

描述了城域光传送网的3种主要技术——城域WDM环网、以SDH为基础的多业务传送平台、弹性分组环（RPR）的特点和应用，并简略阐述了近期城域光送网的建设思路和发展趋势。     

城域传送网技术分析

分析了城域传送网的结构和可以采用的技术,重点阐述了基于SDH的多业务传送平台(MSTP)、城域WDM环网技术、粗波分复用(CWDM)技术和弹性分组环(RPR)四种主要城域光传送网技术的功能及其主要特点,为运营商城域传送网的发展建设提供了多种技术手段。     

浅析城域网的发展与技术选择

本文结合城域网的基本概念，介绍了城域光传送网的3种主要技术：城域WDM环网、以SDH为基础的多业务传送平台（MSTP）、弹性分组环（RPR），阐述了城域网的建设和发展。[编者按]     

一种高效的IP城域环网解决方案-RPR+CWDM

分析了多业务同步数字序列(SDH)、城域波分复用(WDM)和以太网的城域环网的解决方案,为了解决这3种方案的不足,提出了弹性分组环(RPR)+粗波分复用(CWDM)的城域网解决方案,详细描述了这种方案的机制、帧定义和保护等.     

一种高效的IP城域环网解决方案—RPR十CWDM

分析了多业务同步数字序列(SDH)、城域波分复用(WDM)和以太网的城域环网的解决方案，为了解决这3种方案的不足，提出了弹性分组环(RPR) 粗波分复用(CWDM)的城域网解决方案，详细描述了这种方案的机制、帧定义和保护等。     

MSTP多业务传输平台在广电网络中的应用

城域光传输网的主要技术包括同步数字体系（SDH）、以SDH为基础的多业务传送节点（MSTP）、城域波分复用（WDM）环网、粗波分复用（CWDM）以及弹性分组环（RPR）；城域宽带无线接入技术主要有本地多点分配业务（LMDS）、自由空间光通信（FSO）。     

MSTP技术现状及应用

近年来城域传送网的建设方兴未艾，随着通信网络运营商的竞争重点已从骨干网转向城域网，建立高效经济的支持多业务的城域传送网已经成为运营商的共同目标。从技术的角度，多种技术层出不穷，城域光传送网的主要技术包括SDH、以SDH为基础的多业务传送平台（MSTP）、城域波分复用（WDM）环网、粗波分复用（CWDM）以及弹性分组环（RPR）。城域宽带无线接入技术主要有LMDS、     

Photonic packet WDM ring networks architecture and performance

This article reviews various WDM ring architectures and pays special attention to their implementation in the metropolitan environment. A number of possible network architectures as well as protocols are reviewed. The article also proposes and analyses a WDM slotted-ring network architecture with nodes that use one fixed transmitter and fixed receivers. Used as a metropolitan access network, it is shown through simulation how a simple slotted MAC protocol can be implemented in this network to achieve efficient bandwidth utilization. Throughput, delay and packet dropping probability results are presented under Poisson and self-similar traffic.     

A cost-effective approach to introduce an optical WDM network inthe metropolitan environment

A case study shows that an optical wavelength division multiplexing (WDM) network can be employed in a metropolitan network in a cost effective way. In part, cost savings are realized due to the total number of line terminals required and the fact that the dimensions of the electrical nodes decrease when exploiting optical cross connects (OXCs) to a large extent. Optical WDM rings are also an important building element when designing a metropolitan network. A number of the properties of WDM rings are classified, resulting in eight different ring architectures. Additional requirements arise when considering ring-to-ring connections. The extent of the rings chosen for the case study is validated from the transmission point of view by a simple model. Finally, as an alternative to an all-optical approach, an opto-electrical approach is presented     

Metro WDM networks: performance comparison of slotted ring and AWG star networks

Both wavelength-division-multiplexing (WDM) networks with a ring architecture and WDM networks with a star architecture have been extensively studied as solutions to the ever increasing amount of traffic in the metropolitan area. Studies typically focus on either the ring or the star and significant advances have been made in the protocol design and performance optimization for the WDM ring and the WDM star, respectively. However, very little is known about the relative performance comparisons of ring and star networks. In this paper, we conduct a comprehensive comparison of a state-of-the-art WDM ring network with a state-of-the-art WDM star network. In particular, we compare time-slotted WDM ring networks (both single-fiber and dual-fiber) with tunable-transmitter and fixed-receiver (TT-FR) nodes and an arrayed-waveguide grating-based single-hop star network with tunable-transmitter and tunable-receiver (TT-TR) nodes. We evaluate mean aggregate throughput, relative packet loss, and mean delay by means of simulation for Bernoulli and self-similar traffic models for unicast traffic with uniform and hot-spot traffic matrices, as well as for multicast traffic. Our results quantify the fundamental performance characteristics of ring networks versus star networks and vice versa, as well as their respective performance limiting bottlenecks and, thus, provide guidance for directing future research efforts.     

WDM全光网SHAONET的快速自愈保护

基于波长路由的ＷＤＭ全光网是下一代高速宽带光纤网络的首选技术。ＳＨＡＯＮＥＴ是国内自主开发的第一个ＷＤＭ全光试验网平台,它采用了一种新型保护结构的ＯＡＤＭ,具有很强的自愈功能。本文阐述了ＳＨＡＯＮＥＴ中采用的快速自愈保护机制及其实现。     

AWG-based metro WDM networking

A plethora of metropolitan area wavelength-division multiplexing networks have been proposed and examined in recent years with the aim to alleviate the bandwidth bottleneck between increasingly higher-speed local/access networks and high-speed backbone networks. Many of the considered metropolitan area networks use the arrayed waveguide grating as an optical building block. As we review in this article, in ring, interconnected ring, and meshed metro WDM networks, the AWG is typically used to realize wavelength multiplexers, demultiplexers, or optical add-drop multiplexers without capitalizing on spatial wavelength reuse. By using the AWG as a wavelength router, highly efficient star metro WDM networks can be realized due to extensive spatial wavelength reuse. We give an overview of star metro WDM networks that are able to meet modular upgradability, transparency, flexibility, efficiency, reliability, and protection requirements of future metro networks. AWG-based star networks also enable an evolution path of ring networks toward highly efficient and fault-tolerant hybrid star-ring metro network solutions.     

基于Dijkstra算法的城域mesh系统最佳路由研究

5G通信时代的到来使城域波分系统从传统的环形向mesh形演进,OXC技术的引入让mesh形组网变得更加便捷。本文通过利用Dijkstra算法和偏离路径Yen算法解决城域mesh波分系统中最短路由和备用路由的规划选择问题,让业务在城域传送网中的时延得到优化以满足5G业务大带宽低时延的要求。     

Design Considerations for Transmission Systems in Optical Metropolitan Networks

Wavelength division multiplexing (WDM) has become a key technology in optical long-haul communications and wide area networks. Recently, interest in introducing WDM into metropolitan networks has increased. We look at some issues pertinent to the design of WDM transmission systems deploying optical add/drop multiplexers in these networks. In particular, we investigate the interaction of node-induced crosstalk with fiber nonlinearities in metropolitan ring networks. Two transmission systems are considered; namely a system of nonzero dispersion shifted fiber operating in the anomalous dispersion regime and another one of single mode fiber with post dispersion compensation. Data rate is assumed to be 10 Gb/s per wavelength. The dependence of the crosstalk/nonlinearity interaction and its system penalty on the frequency difference between signal and crosstalk carriers, input signal power, extinction ratio, number of nodes, and physical span of the network is examined in detail. It is shown that node-induced crosstalk can interact with fiber nonlinearities and introduce limitations on transmission performance. This interaction should therefore be taken into consideration in designing regional metropolitan networks.     

Amplifier placement methods for metropolitan WDM ring networks

This paper presents two new amplifier placement methods to minimize the number of amplifiers in metropolitan wavelength-division-multiplexing (WDM) rings based on integer programming techniques. The first method describes the amplifier placement problem exactly and uses a nonlinear programming solver to obtain a solution. The second method approximates some requirements in the problem and employs a linear programming solver to derive the amplifier placement solution. A new amplifier placement method for self-healing WDM rings is also reported in this paper. The new method is based on iteratively solving an amplifier placement problem for a ring network under different link failure scenarios. The solution provides a minimum number of amplifiers required to operate the self-healing ring under a normal or any single-link or single-node failure conditions.     

Scalability of a Metropolitan Bidirectional Multifiber WDM-Ring Network

We analyze the scalability of a metropolitan bidirectional multifiber wavelength-division-multiplexed (WDM) ring network. The analysis is carried out by using a bidirectional transmission model for optical networks and by building an experimental network. The model includes major limiting factors in WDM-ring networks such as relative intensity noise (RIN) due to multiple Rayleigh backscattering, amplified spontaneous emission (ASE) accumulation in a cascade of bidirectional erbium-doped fiber amplifiers (EDFA), tilting of the EDFA gain spectrum and input saturation power of the EDFA. We found that in metropolitan areas the scalability of a WDM-ring network using bidirectional transmission is not mainly limited by the RIN arising from the Rayleigh backscattering. The result was verified experimentally. The maximum size of the demonstrated network is 33–43 nodes with a spacing of 5–10 km between nodes. With this spacing, which is typical in metropolitan areas, the scalability of the network is mainly limited by the gain tilt and the input saturation power of the EDFA.     

基于IP over WDM的光城域网

提出了基于IP over WDM的光城域网方案,详细阐述了波长选路WDM光城域网的多级网络拓扑及波长配置方式,并分析了波长配置方式对波长选路由策略的影响。