光传送网分层结构与网络管理的研究

本文从便于管理的角度对引入光层的光传送网重新进行了分层，并将光层进一步分为光通道层、波长复用段层和多波长放大段层。文中定义了光层中各子层的功能，并对各层中遇到的问题给出了解决方案。根据光层中故障的特点，提出了光层中各子层的性能监测和保护机制的要求和实现方案。最后，按电信管理网的概念和结构，结合光层的特点，设计了光层管理系统结构。     

组播技术及其在光层的实现

带宽密集型的多媒体应用对现有网络提出了新的要求,组播技术有助于解决其在网络带宽和服务质量方面的问题,而在光层实现组播具有更简单、高效的特点.然而,光层组播由于光缓存、光分束和光波长变换等光器件的限制,呈现出和IP层组播不同的特点.对IP层和光层组播进行了讨论,分析了光层组播模型,并对稀疏光分束和稀疏波长变换的光网络组播路由提出了重路由到源和重路由到相关节点两种重路由方式.     

多光纤WDM网中的QoS路由算法

利用区分光业务(DOS)模型可以将WDM光传送网中客户层(如IP)具有不同QoS要求的业务汇聚力较粗粒度的流,直接映射到光信道上,从而使客户层业务的不同QoS要求可以体现在DOS域的边缘光节点处的光路建立请求的不同优先级上。该文首先探讨了如何将多光纤WDM网转化为波长图,从而一次性解决选路和分配波长(RWA)问题,在此基础上,提出两种用于多光纤WDM网的QoS路由算法,对二者进行了比较,并进行了计算机仿真。     

WDM光网络的保护和恢复技术

文章概述了IP、SDH和WDM层网络的生存性技术,重点介绍了光传送网的光层生存性技术与光网络恢复技术,还对故障定位、多层生存性机制的协调等问题进行了简单介绍,最后给出了一个业务配置RWA算法与恢复RWA算法的实际方案。     

未来光核心网的体系结构与波长路由技术

概要介绍了未来光核心网体系结构和实现光核心网智能化节点-波长路由器的波长路由技术,重点讨论了思科系统公司提出的波长路由协议-WaRP,最后指出了光核心网进一步发展的两项关键技术。     

基于WDMA方式的EPON关键技术分析与实现

指出基于TDMA方式的EP0N方案的诸多技术难点,结合原有的关于"光通信用DWDM精确波长激光器"的研究基础,提出了用WDMA方式来实现EP0N的方案.根据对整个系统的划分和两种方案的不同点(软件部分、硬件部分、光层部分),着重论述了光层部分,并就其关键部分的实现给予了详细的设计说明.     

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。     

面向未来的通信骨干网

网络信息爆炸式地增长和IP技术不断发展极大地促进宽带IP骨干网的迅猛发展,基于光波分复用的IP传送网技术（光因特网）提供了最有效的IP骨干网解决方案。简要介绍了IP over WDM协议分层模型和网络体系结构,讨论了IP over WDM的帧结构等关键性技术,探讨了IP over WDM的发展前景。     

T－MPLS领衔分组传送网PTN

PTN的出现是光传送网技术发展在通信业务提供商现实的网络和业务环境下的必煞结果。最初没想的理想光传送网IP over WDM方案是IP分组通过简单的封装适配直接架构在智能的光层之上,适配层功能尽量简化从而被限制在接口信号格式的范围内,然后由统一的控制平面在所有层面上（分组、电路、波长、波带、光纤等）实现最高效率的光纤带宽资原调度。这一目标很早就已明确,但其技术的戎熟还有恃时日．     

波分复用全光网络及其波长转换技术

波长转换是实现ＷＤＭ全光网络的关键技术之一。通过波长转换，可以减小由于波长竞争带来的阻塞概率，使网络所需滤长数变为最小，网络管理和控制更加灵活，并具有高的可靠性和可扩充性。基于半导体光放大器的全光波长转换技术具有大的优势。本文首先介绍了ＷＤＭ全光网络的概念，分层模型及其优势，然后指出滤长转换的重要性和技术要求，最后分别介绍了基于半导体光放大器的三种滤长转换器的原理、结构和各自的优缺点。     

WDM智能光网络与IP业务

详细分析了 ＷＤＭ光网络的结构以及联网技术的演进过程，对如何压扁网络层次，实现ＩＰ直接ｏｖｅｒ ＷＤＭ，发挥 ＷＤＭ光传送网的巨大带宽优势进行了研究，提出 ＭＰＬＳ是当前解决 ＩＰ层与光层的融合以及跨层管理问题的关键技术。     

A next-generation optical regional access network

We describe an optical regional access network which combines electronic IP routing with intelligent networking functionality of the optical WDM layer. The optical WDM layer provides such networking functions as network logical topology reconfiguration, optical flow switching to offload traffic and bypass IP routers, wavelength routing of signals, protection switching and restoration in the optical domain, and flexible network service provisioning by reconfigurable wavelength connectivity. We discuss key enabling technologies for the WDM layer and describe their limitations. The symbiosis of electronic and optical WDM networking functions also allows support for heterogeneous format traffic and will enable efficient gigabit-per-second user access in next-generation Internet networks     

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     

A perspective on photonic multiprotocol label switching

Various MPLS-based IP over WDM integration techniques are considered in this article. In particular, this includes the circuit-switching MPλS framework for providing logical IP-layer topologies over optical lightpath routing networks. Additionally, an optical code label switching technique for photonic packet switching and its application to MPLS is also introduced, termed OC-MPLS. The related advantages and challenges of both of these approaches are discussed, and various future research issues are addressed     

IP智能与WDM技术的融合

讨论了在IP over WDM directly分层结构下,IP层网络与光层网络的三种基本融合方式—静态重叠模型、动态重叠模型和动态对等模型,这三种融合方式体现了IP over WDM directly的演变过程。同时还对各种融合方式中网络的组成结构及相应的控制平面技术作了详尽的阐述。     

用MPLS技术实现IP over WDM

提出了一种全新的高速宽带组网技术－基于MPLS的IPoverWDM网络技术,并对其进行了深入研究。这个方案在光联网技术中综合了目前先进的MPLS流量工程控制技术,特别适合于由可重构的OADM和OXC组成的以数据业务为核心的互联网络系统,而且它为最终在IP路由器上直接提供WDM复用功能铺平了道路。     

新世纪初期的光通信网

扼要说明通信网的发展进程,对未来光通信网分别解释其波长路由与波长控制,分组交换与突发交换、以及IP配合ATM和WDM的传送方式。     

WDM光网络上宽带IP的传送方式

综述了基于波分复用 ( WDM)技术的光网络发展以及因特网技术和 IP业务的特点 ,在此基础上介绍并分析比较了光网络上传送 IP的多种方式 ,包括 WDM光网络上ATM、SDH以及千兆比以太网与 IP网络相结合形成网络的协议和结构。最后探讨了未来宽带 IP传送网络的发展方向。     

Optical burst switching for service differentiation in thenext-generation optical Internet

In an effort to eliminate the electronic bottleneck, new optical switches/routers (hardware) are being built for the next-generation optical Internet where IP runs over an all-optical WDM layer. However, important issues yet to be addressed in terms of protocols (software) are how to develop a new paradigm that does not require any buffer at the WDM layer, as in circuit switching, and elimination of any layers between which exist mainly due to historical reasons. At the same time, such a paradigm should also efficiently support bursty traffic with high resource utilization as in packet switching. This article surveys design issues related to a new switching paradigm called optical burst switching, which achieves a balance between circuit and packet switching while avoiding their shortcomings. We describe how OBS can be applied to the next-generation optical Internet, and in particular how offset times and delayed reservation can help avoid the use of buffer, and support quality of service at the WDM layer     

CATZ: Time-Zone-Aware Bandwidth Allocation in Layer 1 VPNs

The layer 1 virtual private network framework has emerged from the need to enable the dynamic coexistence of multiple circuit-switched client networks over a common physical network infrastructure. Such a VPN could be set up for an enterprise with offices across a wide geographical area (e.g., around the world or by a global ISP). Additionally, emerging IP over optical WDM technologies let IP traffic be carried directly over the optical WDM layer. Thus, different VPNs can share a common optical WDM core, and may demand different amounts of bandwidth at different time periods. This type of operation would require dynamic and reconfigurable allocation of bandwidth. This article evaluates the state of the art in layer 1 VPNs in the context of globally deployable optical networks and cost-efficient dynamic bandwidth usage. While exploiting the dynamism of IP traffic in a global network in which the nodes are located in different time zones, we study different bandwidth allocation methods for setting up a worldwide layer 1 VPN. We propose and investigate the characteristics of a cost-efficient bandwidth provisioning and reconfiguration algorithm, called capacity allocation using time zones (CATZ)