核心通信网的光分组交换

文章首先简单说明了新一代通信网需要使用分级交换的由来。接着详细叙述了光分组交换在未来光通信网的应用，包括节点结构、分组格式、输入、输出接口和一些特别重要的技术，如再生、同步、信头处理、缓冲、空间交换和波长转换等。     

An effective buffering architecture for optical packet switching networks

A novel optical buffering architecture for Optical Packet Switching (OPS) networks is proposed in this article. The architecture which adopts a fiber-sharing mechanism aims at solving the problem of using a large number of fiber delay lines that are used to solve resource contention in the core node in OPS networks. The new architecture employs fewer fiber delay lines compared to other simple architectures, but can achieve the same performance. Simulation results and analysis show that the new architecture can decrease packet loss probability effectively and achieve reasonable performance in average packet delay.

规则全光分组网络中偏射路由算法的分析

就在ShuffleNet和Manhattan Street Network两种规则网络中使用偏射路由算法后的网络性能以及允许一个时隙插入多个数据包对该算法的影响进行了分析。结果说明，偏射路由算法不仅能使网络得到较高的性能，而且发挥了网状网具有迂回路由的能力。当采用允许插入多个数据包的策略时，网络的吞吐量和平均跳转次数都有小幅度的增加。     

The European IST project DAVID: a viable approach toward optical packet switching

In this paper, promising technologies and a network architecture are presented for future optical packet switched networks. The overall network concept is presented and the major choices are highlighted and compared with alternative solutions. Both long and shorter term approaches are considered, as well as both the wide-area network and multiple-area networks parts of the network. The results presented in this paper were developed in the frame of the research project DAVID (Data And Voice Integration over DWDM) project, funded by the European Commission through the IST-framework.     

A novel architecture of optical code label generation and recognition for optical packet switching

A novel architecture of optical code (OC) label generation and recognition for optical packet switching (OPS) by using super structured fiber Bragg grating (SSFBG) is proposed.The OC label is generated and recognized by a label generator and recognizer,respectively.The label generator is composed of N encoders in parallel,and it can generate 2N kinds of serial optical code labels (SOCLs) for indicating 2N network routing information.The label recognizer can decode SOCLs by N decoders in parallel and provides label information to the switching control unit so that clock information is not required during the decoding process.In the switch nodes,handling of the high-speed information payload stream and the recognition of the OC label are performed in the optical domain,while processing of the routing information remains in the electrical domain.This approach could be a promising solution for an OPS network with high capacity,good quality of service (QoS),multi-service function and high security.In this experiment,we demonstrate 40Gbps 256 label optical packet switching that employs clockless SOCL processing.     

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     

一种基于负载选择的光分组交换缓存结构

提出了一种基于业务负载选择的光分组交换(OPS)网络的光缓存结构,根据业务负载大小灵活选择缓存方式。输出缓存光纤延迟线(FDL)采用分段式共享机制配置,输出/反馈共享缓存模块采用简并式配置,以提高有限数目FDL的利用率。分析和仿真表明,这种可选择的缓存结构可以有效降低丢包率和OPS节点需求的FDL数目。     

光分组交换在下一代电力通信网中的应用

光分组交换是实现光传送网与电层IP网络无缝联接的理想技术.文章以电力通信网络为研究对象,对光分组交换技术在下一代电力通信网络中的应用进行深入探讨.首先,对光分组交换技术进行介绍,并分析了电力通信网的业务特性;然后,介绍了四种适用于电力通信网的光分组交换节点结构,即SMOP交换结构、FWBFWC交换结构、OFBFWC交换结构和RFWC-ROB交换结构.     

An optical router with multistage management functions for asynchronous optical packet switching network

An optical router with multistage distributed management features for the asynchronous optical packet switching (OPS) network is presented, which can improve switching capacity and all-optical scalability. A compact recycling-fiber-delay-line (Rec-FDL) based collision resolution mechanism is proposed to resolve the contentions for asynchronous and variable length optical packets. The analysis models of stabilities, packet loss rates (PLR) and average packet waiting latencies (PWL) for the router are developed based on the timer based optical packet assembly algorithm. The simulation shows that PLR and PWL for a 400-byte optical packet transmitted in the 32 wavelengths dense wavelength division multiplexing (DWDM) system equal to 3.48 × 10⁻⁴ and 0.072 ns, respectively. The non-blocking switching can be realized for the packets with lengths less than the buffer granularity of the Rec-FDL, and the optimized performance for the proposed router can be obtained through properly selecting of the system parameters.     

A novel scheme of all optical header extraction for optical packet switching network

A novel scheme of all optical header extraction using a semiconductor optical amplifier-Mach-Zehnder-Interferometer with asymmetric control light is proposed for optical packet switching with all-optical header processing at a header rate of 20 Gb/s and payload rate of 80 Gb/s in this article. The scheme parameters are discussed and analyzed to optimize the performance of optical header extraction with the proposed scheme. Numerical analysis and simulation show that a more than 17 dB contrast ratio can be achieved for the optical header separation when the input optical signal energy is as low as 0.2 pJ. In addition, the system structure is simple, stable, and photonic integratable.     

Wavelength conversion in optical packet switching

A detailed traffic analysis of optical packet switch design is performed. Special consideration is given to the complexity of the optical buffering and the overall switch block structure is considered in general. Wavelength converters are shown to improve the traffic performance of the switch blocks for both random and bursty traffic. Furthermore, the traffic performance of switch blocks with add-drop switches has been assessed in a Shufflenetwork showing the advantage of having converters at the inlets. Finally, the aspect of synchronization is discussed through a proposal to operate the packet switch block asynchronously, i.e. without packet alignment at the input     

光分组交换的关键技术

在电域内，有电路交换与分组交换之分，随着语音、数据、视频等通信业务正朝着综合的方向发展，数据流量逐渐超过话音流量。这就意味着面向连接的电路交换需要被升级到能支持数据业务的分组交换。分组交换保留电路交换传输时延小的优点，同时克服了线路利用率差的缺点。客观而言，在电域可望取得的进展在一段时间内能满足分组交换的需求，但是研究显示光开发技术的潜力能满足网络的长期需求。互联网快速增长是驱动光分组交换及网络快速发展的动力，得到WDM光传输基础设施的支持。电域TDM技术的增长系数是每年1.5，而每年的带宽需求增长系…     

Clos lives on in optical packet switching

While the technological evolution since C. Clos's seminal article (see Bell Sys. Tech. J., vol.32, p.406-24, 1953) on multistage switch architectures has been huge, his work and ideas still live on. We discuss node architectures for optical packet switching and show how the multistage approach proposed by Clos can be adopted to solve scalability issues and construct switches with large port counts. As in the old days, the driving factors behind the introduction of multistage concepts also include economic issues: compared to a single-stage architecture, the number of components to realize the switching fabric is reduced.     

Approaches to optical Internet packet switching

Wavelength-division multiplexing is currently being deployed in telecommunications networks in order to satisfy the increased demand for capacity brought about by the explosion in Internet use. The most widely accepted network evolution prediction is via an extension of these initial predominantly point-to-point deployments, with limited system functionalities, into highly interconnected networks supporting circuit-switched paths. While current applications of WDM focus on relatively static usage of individual wavelength channels, optical switching technologies enable fast dynamic allocation of WDM channels. The challenge involves combining the advantages of these relatively coarse-grained WDM techniques with emerging optical switching capabilities to yield a high-throughput optical platform directly underpinning next-generation networks. One alternative longer-term strategy for network evolution employs optical packet switching, providing greater flexibility, functionality, and granularity. This article reviews progress on the definition of optical packet switching and routing networks capable of providing end-to-end optical paths and/or connectionless transport. To date the approaches proposed predominantly use fixed-duration optical packets with lower-bit-rate headers to facilitate processing at the network-node interfaces. Thus, the major advances toward the goal of developing an extensive optical packet-switched layer employing fixed-length packets are summarized, but initial concepts on the support of variable-length IP-like optical packets are also introduced. Particular strategies implementing the crucial optical buffering function at the switching nodes are described, motivated by the network functionalities required within the optical packet layer     

Hybrid and optical packet switching supporting different service classes in data center network

Photonic Network Communications - Optical packet switching is a prominent technology proposing not only a reduction in the energy consumption by the elimination of numerous...     

Protection-against-collision optical packet network

An optically transparent packet network controlled by a simple medium access circuit is presented. The system, based on frequency division multiplexing and tunable transmitters, has no internal blocking and is optically self-routing. It provides internal collision-free traffic by allowing access to the network only if the addressed channel (output port) is available. A packet denied access to the network is reflected back to its input port, which is thus informed of the packet status. Therefore, the traffic is not bogged down by acknowledgments between input and output ports. To achieve this result, each input of the network is controlled by a protection-against-collision (PAC) circuit located at a central hub. The PAC circuit uses the packet for probing the energy present in the addressed channel. The resulting signal controls an optical switch connecting the input port to the network. Thus, full optical connectivity is provided between ports controlled by electrical signals derived from simple optical power measurements     

Dual-fiber optical burst switching network: A novel architecture for metropolitan area networks

Fiber optic rings are widely deployed in metropolitan area networks (MAN). These rings currently employ architectures and protocols that are neither optimized for nor scalable to the network demand. Therefore, emerging technologies are being pushed to replace the traditional architectures. Among these technologies, optical burst switching (OBS) is an effective and promising technology. In this study, a novel architecture, dual-fiber OBS (DOBS), is proposed. This architecture has similar functions to those of fiber delay lines, partial wavelength conversion and deflection routing. A theoretical model is developed to evaluate the performance of DOBS, which is compared with single-fiber and simple two-fiber schemes by introducing them into ring and mesh MAN in simulations. The results reveal that DOBS can exponentially reduce the burst dropping probability. Moreover, since DOBS can be implement using commercially available devices and dark fibers, it is commercially viable in metro networks.     

光分组交换中的波长变换器配置研究

首先对波长变换器的功能及分类进行详细的论述,然后,对波长变换器的配置进行分析,总结出两种波长变换器配置方法,即独占式配置方法和共享式配置方法.针对独占式配置方法,本文使用仿真实验的方法研究了在不同类型的波长变换器下交换节点丢包性能的差异.本文还对独占式配置方法和共享式配置方法进行对比研究.     

Design of a broadcast packet switching network

An overview is given of a system designed to handle a heterogeneous and dynamically changing mix of applications. It is based on fiber-optic transmission systems and high-performance packet switching and can handle applications ranging from low-speed data to voice to full-rate video. A novel feature is a flexible multipoint connection capability suitable for broadcast and conferencing applications. The architecture of a switching systems that can be used to support this network is described