光交换技术

现代通信技术正向着宽频、高速和数字化的方向发展,能承担诸如话音、数据、图象等各种通信业务的综合业务数字网已于1980年正式列入CCITT标准项目。随着光纤通信等光技术的实用化和高性能化,以及为了适应今后超工业化、信息化社会对通信的需要,出现了一种新型的交换技术——光交换技术。     

光交换技术

光交换技术是令世人瞩目的新技术，这项技术的实用化将是２１世纪发展的必然趋势。因此，本文论述了光交换技术发展的过程，介绍了三类光交换系统的概况和光器件突破性的进展新及结构接排，对光交换系统的发展前景做了乐观的分析。     

交换技术的新宠——光交换

光交换是指对光纤传送的光信号直接进行交换。与电子数字程控交换相比 ,光交换无须在光纤传输线路和交换机之间设置光端机进行光 /电(Ｏ /Ｅ)和电 /光 (Ｅ /Ｏ)变换 ,而且在交换过程中 ,还能充分发挥光信号的高速、宽带和无电磁感应的优点。光纤传输技术与光交换技术融合在一起 ,可以起到相得益彰的作用 ,从而使光交换技术成为通信网交换技术的一个发展方向。光交换技术的交换方式可分为空分光交换(ＳＤＰＳ)、时分光交换 (ＴＤＰＳ)、波分光交换(ＷＤＰＳ)、复合型光交换和自由空间光交换(ＦＳＰＳ) 5种方式。(1 )空分光交换 (ＳＤＰＳ)Ｓ…     

下一代光互联网交换技术--光突发交换的关键技术

本文阐述了光突发交换技术的基本原理,并对OBS中资源预留协议、流量等级、资源竞争、预约机制和偏置时间确定等关键技术进行了介绍。简要指出了OBS面临的瓶颈以及未来主要研究方向。     

下一代光互联网交换技术——光突发交换的关键技术

本文阐述了光突发交换技术的基本原理，并对OBS中资源预留协议、流量等级、资源竞争、预约机制和偏置时间确定等关键技术进行了介绍。简要指出了OBS网面临的瓶颈以及未来主要研究方向。     

光网络中的光交换技术

在对光交换技术深入研究的基础上，对光网络中的关键器件，声光可调滤波器及光缓存器作了详细介绍，最后对光交换的发展前景作了展望。     

光ATM交换技术

本文介绍两种用于大容量交换系统的光ＡＴＭ信元交换结构，一种是以超短光脉冲为基础的广播及选通（ｂｒｏａｄｃａｓｔ—ａｎｄ—ｓｅｌｅｃｔ）星形网；另一种是以具有光矩阵开关为基础的超立方网。文中描述及论证了支持这些结构的关键技术及其实现结果。例如：高速信元形成，全光寻址匹配和全光同步电路     

Data transparent reconfigurable optical interconnections usingpolarization switching in VCSEL's induced by optical injection

We demonstrate a data transparent reconfigurable optical interconnection system based on optical injection controlled polarization switching in a master-slave vertical-cavity surface-emitting laser (VCSEL) configuration. A 140-Mb/s data stream generated by the slave VCSEL is redirected by an anisotropic diffractive optical element depending on the polarization state of the emitted light. The polarization of the slave laser is controlled by injecting an orthogonally polarized optical signal from a master laser. The current modulation of the master VCSEL and the subsequent polarization switching of the slave VCSEL occur at 40 MHz. In our setup, both the data rate and the optical interconnection reconfiguration rate are limited by the electronic drive circuitry and could in principle attain the gigahertz range     

Techniques for optical packet switching and optical burst switching

Wavelength-division multiplexing appears to be the solution of choice for providing a faster networking infrastructure that can meet the explosive growth of the Internet. Several different technologies have been developed so far for the transfer of data over WDM. We survey two new technologies which are still in the experimental stage-optical packet switching and optical burst switching-and comment on their suitability for transporting IP traffic     

Management and control of transparent optical networks

Multiwavelength optical networking is expected to play a significant role in the next-generation transport networks providing capacity enhancements as well as built-in network survivability and reconfigurability. While advances have been made in the hardware technologies, considerable research effort is still required in the area of network management and control in order for optical networking to be proven commercially viable. This paper investigates key design issues concerning optical network management and control and examines how the networking architecture is influenced by the various management considerations     

全光网络的透明性和管理信息传递方案

绍了透明光网络管理和控制的有关问题 ,研究了透明光网络的结构以及配置管理问题 ,针对光网络缺少空闲信号 ,提出了一种告警压缩机制 ,最后介绍了光网络的抗毁性。     

Hybrid switching and p-routing for optical burst switching networks

One promising switching technology for wavelength-division multiplexing optical networks is optical burst switching (OBS). However, there are major deficiencies of OBS. (1) The delay offset between a control message and its corresponding data burst is based on the diameter of a network. This affects network efficiency, quality-of-service, and network scalability.( 2) OBS adopts one-way resource reservation scheme, which causes frequent burst collision and, thus, burst loss. We address the above two important issues in OBS. In particular, we study how to improve the performance of delay and loss in OBS. To reduce the end-to-end delay, we propose a hybrid switching scheme. The hybrid switching is a combination of lightpath switching and OBS switching. A virtual topology design algorithm based on simulated annealing to minimize the longest shortest path through the virtual topology is presented. To minimize burst collision and loss, we propose a new routing algorithm, namely, p-routing, for OBS network. The p-routing is based on the wavelength available probability. A path that has higher available probability is less likely to drop bursts due to collision. The probability-based p-routing can reduce the volatility, randomness, and uncertainty of one-way resource reservation. Our studies show that hybrid switching and p-routing are complementary and both can dramatically improve the performance of OBS networks.     

一种新型光交换技术:光码标签突发包交换

一种新型光交换技术-光码标签突发包交换技术。该技术是光突发包交换与光码标签交换的结合体，具有两者的共同优点，是一种性能优良的光交换技术。本文首先介绍了该技术的原理，然后给出了网络节点功能结构的设计，最后讨论了该技术的性能。     

Hierarchical time-sliced optical burst switching

To overcome the need for large buffers to store contending bursts in optical burst switched (OBS) networks, a recent variant called time-sliced OBS (TSOBS) suggested that bursts be sliced and spread across multiple frames of fixed-length time-slots. Since TSOBS is rigid in its frame structure, this paper generalises TSOBS to allow a hierarchy of frames. Termed hierarchical TSOBS (HiTSOBS), this scheme supports several granularities of rates, and permits multiple traffic classes with different loss-delay requirements to efficiently share the network. Our contributions are as follows: first, we present an architecture for HiTSOBS and offer it as a viable option for the realisation of flexible and cost-effective OBS networks. Second, we develop mathematical analysis to study the loss and delay performance of the proposed HiTSOBS system. Finally, we present simulation results that captures these loss-delay tradeoff values. Our HiTSOBS architecture gives network operators the freedom to choose the right mix of traffic with desired loss-delay requirements to coexist in the network.     

Bistable solitons and optical switching

Using a particular nonlinearity (the "linear + smooth step" model) as an illustrative example, it is demonstrated numerically that cyclic switching between bistable soliton states of the highly-non-linear (generalized) Schriödinger equation can occur. Some important aspects of the switching process, including the nature and role of the intermediate states, are discussed. This numerical simulation may serve as a model of optical switching between distinctly different soliton states in a nonlinear optical fiber and should stimulate the search for the materials and mechanisms with appropriate nonlinearities.     

基于业务流的混合光交换网络

在包括了光突发交换和光电路交换的混合光交换网络中,对IP区分服务的流量进行分类.在混合交换中,时延敏感的短期流量使用OBS,丢包敏感的长期流量使用OCS.混合光交换的目的在于网络利用的最大化,并满足用户的QoS需求.     

Digital MEMS for optical switching

Over the last few years an amazing amount of interest has emerged for applications of micro electro-mechanical systems (MEMS) in telecommunications. Silicon-based optical MEMS have proven to be the technology of choice for low-cost scalable photonic applications because they allow mass manufacturing of highly accurate miniaturized parts, and use materials with excellent mechanical and electrical properties. Applications include tunable lasers, optical switches, and tunable filters. The use of MEMS for optical switching has turned out to be most attractive since this application could revolutionize fiber optic telecommunications. We discuss the technology, performance, and reliability of 2D MEMS optical switches. We show that this technology meets the scalability, performance, and reliability requirements for important applications in fiber optic networks