波分复用光网络中的波长路由分配策略

路由选择和波长分配是WDM光传输网中非常重要的问题.本文结合交叉连接节点,提出了一种基于最短路径的动态路由选择方案;然后利用这种动态的路由选择策略,以网络的阻塞性能为优化目标分配波长,达到充分利用网络资源的目的.计算机仿真结果表明,无论在单纤或者多纤WDM光传输网络中,利用这种策略的RWA算法优于传统的固定路由和单纯动态路由算法     

基于D*思想的动态RWA算法研究

文章提出一种基于D*(D-Star)思想的启发式算法,求解波分复用(WDM)光网络中动态路由和波长分配(RWA)问题.将网络中各边代价与当前波长使用情况综合考虑,建立D*算法的估价函数,实现了WDM光网络中动态业务的高效分配.仿真结果表明,该算法能有效降低阻塞率,促进波长资源的合理分配,同时,其快速和智能特性也提高了网络故障环境下的生存性.     

WDM-TDM光网络中的动态波长路由与时隙分配算法研究

在WDM光网络中,为了进一步提高波长资源的利用率,多个业务连接可以通过时分复用(TDM)技术共享一个波长的容量。在这种基于WDM-TDM技术的光网络中建立业务连接,需要解决的核心问题之一是波长路由与时隙分配(RWTA)问题。该文研究了WDM-TDM光网络中的动态RWTA问题,提出了一种基于最大使用率方法的RWTA算法(MUB)和一种改进的MUB算法(EMUB),并对它们的性能进行了计算机仿真分析。结果表明:EMUB算法的阻塞率性能优于MUB算法,能有效地优化WDM-TDM光网络的资源利用率。     

WDM光网络中动态RWA算法仿真的实现

在WDM光网络中，在给定一组连接请求后，需要为之建立路由并分配波长，这被称为路由和波长分配问题（RWA）。由于当前光网络中的业务呈现爆炸式的增长，而光网络中的可用资源却是有限的，因此如何使用合理的RWA算法来优化网络资源的利用就显得尤为重要。目前已有很多文献提出了基于各种优化目标的RWA算法，也都通计算机仿真的方法测试和评估了算法的性能。计算机仿真是进行算法性能评估的主要手段，但是关于算法仿真的实现，—般的文献都涉及的很少，本文主要研究了WDM光网络中动态RWA算法计算机枋真的实现。     

WDM疏导网络中基于光路的动态恢复

针对波分复用(WDM)网络中单链路出错的生存性流量疏导问题,文章提出了一种基于光路的动态恢复机制(DRAL).DRAL不预留任何资源,当链路出错时,通过在网络中动态地发现资源来对错误链路进行恢复,将一个出错的光路转发到一条新建立的光路或其他可用的光路上.仿真结果显示,DRAL拥有很高的恢复概率.     

基于蚁群系统的分布式RWA算法研究

针对波分复用(WDM)光网络中动态选路和波长分配(RWA)问题，提出了一种基于蚁群算法的分布式动态RWA方法。将蚁群算法与分层图模型结合，实现了RWA的并行计算。仿真结果表明，与现有最短路径法相比，该算法能有效地降低光路阻塞率，促进波长资源的合理分配，同时分布式的计算方式也降低了现代频繁变化的大型光网络的通信开销。     

WDM 网络中基于优先级的多任务波长路由分配算法

提出了一种在WDM网络中基于优先级的多任务波长路由分配算法。算法设计旨在提高光网络资源的利用率、降低网络请求阻塞率。分析了任务请求的路由类型以及负载容量对请求优先级划分的影响方式,给出了网络请求优先级划分策略,结合网络的实时状态提出了一种基于优先级的多任务波长路由分配算法。仿真结果表明,该算法相比现有算法降低了网络请求阻塞率,提高了资源利用率。     

WDM网络中一种支持优先级的波长分配算法

有效的算法能大大的提高波长利用率,文中研究了WDM光网络在固定路由无波长转换条件下的波长分配算法,以便充分挖掘WDM网络的带宽资源。提出了一种基于RLI并考虑通道优先级的波长分配算法,并给出了该算法的具体实现步骤。最后的仿真结果表明,与RLI算法相比该算法显著的降低了网络的阻塞率,有利于提高网络资源的利用率。     

WDM全光通信网技术及其发展

在IP业务的高速增长和WDM技术提供超大容量带宽资源的双重刺激下,传统光网络正在朝着适于传输IP业务的新一代光网络演进。本文描述了WDM光传送网的发展与现状,讨论了基于OXC和OADM的WDM光传送网技术,并对下一代光网络的发展进行了分析和展望。     

WDM/OTDM混合光网络系统性能仿真研究

基于optisystem详细讨论如何构建一个完整的WDM/OTDM混合光网络仿真系统.仿真中信源采用经过RZ调制的信号,波长转换采用基于SOA-XGW的全光转换方式,传输采用色散补偿光纤补偿传输过程中的色散,解复用采用PLL光时钟提取方法.经过对仿真结果图的分析,表明经过以上改进处理可以改善WDM/OTDM混合光网络的传输性能,为混合光网络的商用提供参考.     

A management and visualization framework for reconfigurable WDM optical networks

As the phenomenal advance in optical WDM networking technologies continues, optical WDM network equipment has been deployed not only in backbone networks, but also in regional, metropolitan, and access networks. It is widely believed that a major component of the next-generation Internet will be an IP-based optical network employing WDM. WDM wavelength routing and signaling have become an active research field, and dynamic and adaptive wavelength routing and assignment algorithms have been proposed. However, there is less work on reporting network control and management system implementation efforts over testbed WDM networks. This article presents a network management and visualization framework aimed at guiding the development of management applications for reconfigurable WDM optical networks. A layered framework architecture including element and network management and visualization is provided, and an object-based information model representing the WDM network is introduced. Functional components on reconfiguration, software agent, and network visualization services are presented, and important issues related to optical lightpath generation are discussed. A network visualization service also provides WDM control and management APIs to applications and access networks such as an IP network management system. To illustrate the usage of the framework, we share our experience in implementing the MONET network control and management system, and present network visualization views obtained from the MONET WDM network to highlight the framework features.     

WDM全光网网络管理系统的设计与实现

基于波长路的ＷＤＭ全光网是下一代高速宽带光纤网络的首选技术，如何对它进行有效而灵活的管理是目前研究的热点。ＳＨＡＯＮＥＴ是国内自主开发的第一个ＷＤＭ全光试验网，它具有自己网络管理系统，可以实现配置管理、性能管理和故障管理。本报导了ＳＨＡＯＮＥＴ网络的设计和它基于ＳＮＭＰ的实现。     

WDM在SDH传输网中应用的技术问题

波分复用技术 ( WDM)在中国电信同步数字体系 SDH光传输网中的广泛运用 ,必将极大地满足宽带长途传输和接入的需求。通过分析波分复用技术相对于时分复用技术( TDM)的优越性及其在 SDH传输网中的应用 ,讨论了 SDH网络中使用 WDM的关键技术 ,并探讨了 WDM与 SDH网络管理一体化的技术方案和优势     

Advances in the management and control of optical Internet

Given the ever increasing demand for network bandwidth, and the phenomenal advances in optical wavelength division multiplexing (WDM) networking technologies, a major component of the next generation Internet will be an Internet protocol (IP)-based optical WDM network. As IP over WDM networking technologies mature, a number of important architectural, management and control issues have surfaced. These issues need to be addressed before a true next generation optical Internet can emerge. We enumerate some of the key architectural, management and control issues and discuss corresponding approaches and advances made toward addressing these issues. We first review the different IP/WDM networking architectural models and their tradeoffs. We outline and discuss several management and control issues and corresponding approaches related to the configuration, fault, and performance management of IP over dynamic WDM networks. We present an analysis and supporting simulation results demonstrating the potential benefits of dynamic IP over WDM networks. We then discuss the issues related to IP/WDM traffic engineering in more detail, and present the approach taken in the NGI SuperNet Network Control and Management Project funded by DARPA. In particular, we motivate and present an innovative integrated traffic-engineering framework for reconfigurable IP/WDM networks. It builds on the strength of multiprotocol label switching for fine-grain IP load balancing, and on the strength of reconfigurable WDM networking for reducing the IP network's weighted-hop-distance, and for expanding the bottleneck bandwidth     

Connection management for multiwavelength optical networking

This paper describes the connection management research done by the Network Control and Management (NC&M) task force under the multiwavelength optical networking (MONET) program. MONET is sponsored by the Defense Advanced Research Project Agency (DARPA) the US Government Department of Defense, with participation from Bellcore, AT&T, Lucent Technologies, several government agencies, and regional Bell operating companies. MONET's vision is to develop a flexible reliable high-capacity high-performance cost-effective national optical network based on multiwavelength fiber optic technology. As an important component in realizing this vision, the MONET program includes the architecture and design of a prototype network control and management system for MONET's reconfigurable wavelength-division multiplexing (WDM) all-optical network. The primary objectives of the prototype research work are to develop the architecture and framework for managing national-scale transparent reconfigurable WDM optical networks and to demonstrate the feasibility of the NC&M prototype system in a field experiment network in Washington, DC. This prototype system allows the program participants to conduct experiments and gain experience in the management and operations of reconfigurable optical networks. This paper describes the connection management aspects of the prototype system, addressing issues such as the management architecture, information model, and provisioning algorithms of the prototype management system     

基于相干光正交频分复用的WDM传输系统及其性能分析

相干光正交频分复用由于其良好的传输性能成为近年来光传输领域的研究热点,波分复用技术可以在光纤中通过增加并行波长的数量来提高系统的容量,将CO-OFDM和WDM技术结合,可以构造出高速率、大容量、低成本的光传输网络。文章首先对基于CO-OFDM的WDM传输系统的理论模型和基本原理进行了研究,然后对基于CO-OFDM的100Gb/s×32-信道WDM传输系统进行了仿真分析。并研究了该系统的传输性能。结果表明：在没有任何光纤的色散及非线性补偿的情况下,当信号速率为3.2 Tb/s时,系统的Q因子高于16.0 dB,在标准单模光纤中的传输距离可达1500km。     

全光光孤子WDM到OTDM转换的概念系统

提出了在未来的光孤子波分复／时分复用网络中由ＷＤＭ到ＯＴＤＭ节点处的转换复用的概念系统，主要的模块是完成波长转换的基于交叉增益调制的半导体光放大器，同步和延时及时分复用模块。通过ＳＯＡ可以实现全光的ＷＤＭ到ＯＴＤＭ的波长转换复用，是ＷＤＭ／ＯＴＤＭ网络实用化的一个关键部分。     

Traffic grooming in mesh WDM optical networks - performance analysis

Traffic grooming is an important task in interworking between the wavelength-division multiplexing (WDM) optical network that supplies "pipes" at the wavelength granularity, and the attached client networks that usually require connections of subwavelength granularity. The focus of this paper is to conduct performance analysis of grooming dynamic client traffic in WDM optical networks with a mesh topology. This paper first briefly introduces the traffic grooming problem in WDM optical networks and the issues related to performance analysis. It then develops two link blocking models, an exact model based on the stochastic knapsack problem and an approximation model based on an approximate continuous time Markov chain (CTMC). The end-to-end performance analysis is conducted using the reduced load approximation. The result obtained from analysis is shown to be accurate compared with the numerical result obtained from simulation.     

A novel medium access control protocol for WDM-based LAN's andaccess networks using a master/slave scheduler

We describe an architecture and medium access control (MAC) protocol for wavelength-division multiplexing (WDM) networks. Our system is based on a broadcast star architecture and uses an unslotted access protocol and a centralized scheduler to efficiently provide bandwidth-on-demand in WDM networks. To overcome the effects of propagation delays the scheduler measures the delays between the terminals and the hub and takes that delay into account when scheduling transmissions. Simple scheduling algorithms, based on a look-ahead capability, are used to overcome the effects of head-of-line blocking. An important application area for this system is in optical access networks, where this novel MAC protocol can be used to access wavelengths in a WDM passive optical network (PON)     

无线ATM通信网多址访问协议与信道动态分配算法研究

本文为无线ATM通信网提出了可支持话音、数据和图像业务的多址访问控制协议(MAC)和信道动态分配(DCA)算法.所提出的正交码预约多址访问协议(ORMA)可避免各终端在预约竞争时发生碰撞,提高信道利用率.同时,还提出了一种突发业务信道动态分配算法(DCA-BT),ORMA与DCA-BT相结合能有效地提高系统内多媒体业务的质量和信道利用率,增大系统容量,支持多种业务在无线ATM通信网中的应用.