基于PON网络的安全量子VPN方案

该文提出了一个新的无源光网络PON组成模型。利用该模型设计了一个具有身份认证功能的高效量子密钥分配方案,以满足无源光网络中光线路终端对光网络单元的身份认证和两者间的相互量子密钥分配,以及实现光虚拟专用网内部光网络单元间的量子密钥分配。安全性分析和实验方案表明了该协议的绝对安全性和可行性。将共享密钥作为通信双方的会话密钥,对内部传输数据进行加密,最终实现量子虚拟专用网。     

Study of Optical Transmission Performance in IP‐over‐WDM Networks Based on FSK/ASK Combined Modulation Format

The transmission performance of optical labeling based on a combined frequency shift keying/amplitude shift keying (FSK/ASK) format is studied by numerical simulation. The simulation demonstrates that the bit‐error ratio (BER) characteristic of an ASK signal is limited by the extinction ratio, received optical power, and dispersion, simultaneously. However, an FSK signal is mainly limited by the extinction ratio (ER) and received optical power when the peak spectrum, which is used to detect the FSK signal, is relatively narrow.     

基于调频调幅方式的光标记网络的传输性能

数值模拟了IP-over-WDM光网络中基于频移键控/幅移键控(FSK/ASK)正交调制的光标记信号/净荷的传输性能.结果表明,ASK净荷的传输同时受到调制器消光比、接收光功率及光纤色散的影响;FSK光标记信号则主要受到调制器消光比和接收光功率的影响,几乎不受光纤色散因素的影响.     

Optical Virtual Private Networks: Survivability Against Multiple Link Failures

The Optical Virtual Private Networks (OVPNs) are going to be the next step of the present Internet Protocol or Multi-Protocol Label Switching-based VPNs. Since reliability and continuity of service are the major requirements in the design of OVPN, researchers are now paying more attention to its survivability issue. In this paper, we propose a highly simple approach for spreading out the lightpaths over the core optical network using shortest pair algorithm that mitigates the impact of multiple link failures in an OVPN. The special feature of the proposed Distributed Lightpath Routing algorithm lies in its simplicity and less computation for the working path as well as for the backup path.     

Private and Authentic Communication in Passive Optical Networks

Broadband access systems based on Passive Optical Networks (PONs) present a cost-effective alternative to star-shaped ones. An inherent weakness of PONs lies in their tree topology. This article identifies the measures necessary to support private and authentic two-way communication via a passive tree.     

Multiple Virtual Private Networks Over Passive Optical Networks Using RF Subcarrier Multiplexing and Fabry–PÉrot Laser Diodes

An optical layer solution for implementing multiple virtual private networking capabilities over a passive optical network using subcarrier multiplexed (SCM) transmission is proposed and experimentally demonstrated with 60-Mb/s data multiplexed with two radio-frequency subcarriers. The transmission of the SCM data is carried out using Fabry–PÉrot laser diodes. Experimental results and theoretical analysis show that our technique can potentially support high data rate traffic from a large number of simultaneous virtual private networks with minimal penalty resulting from optical beat interference.     

Virtual Topology Design and Reconfiguration of Virtual Private Networks (VPNs) over All-Optical WDM Networks

This paper studies the virtual topology design and reconfiguration problem of virtual private networks (VPNs) over all-optical WDM networks. To support VPN service, a set of lightpaths must be established over the underlying WDM network to meet the VPN traffic demands and this set of lightpaths must also be dynamically reconfigurable in response to changing VPN traffic. To achieve good network performance and meet the service requirements of optical virtual private networks (oVPNs), we formulate the problem as an integer programming problem with multi-objectives and present a general formulation of the problem. In the formulation, we take into account the average propagation delay over a lightpath, the maximum link load, and the reconfiguration cost with objectives to minimize the three metrics simultaneously. The formulated problem is NP-hard and is therefore not practical to have exact solutions. For this reason, we use heuristics to obtain approximate optimal solutions and propose a balanced alternate routing algorithm (BARA) based on a genetic algorithm. To make the problem computationally tractable, we approximately divide BARA into two independent stages: route computing and path routing. At the route computing stage, a set of alternate routes is computed for each pair of source and destination nodes in the physical topology. At the path routing stage, an optimal route is decided from a set of alternative routes for each of the lightpaths between a pair of source and destination nodes. A decision is subject to the constraints and objectives in the formulation. To improve the computational efficiency, we use a genetic algorithm in BARA. Through simulation experiments, we show the effectiveness of BARA and the evolution process of the best solution in a population of solutions produced by the genetic algorithm. We also investigate the impact of the number of alternative routes between each pair of source and destination nodes on the optimized solutions.     

All-Optical 10 and 40 Gbit/s RZ-to-NRZ Format and Wavelength Conversion Using Semiconductor Optical Amplifiers

We demonstrate that the cross-gain compression (XGC) in a semiconductor optical amplifier can produce effective return to zero (RZ)-to-nonreturn to zero (NRZ) format conversion. This technique is experimentally investigated at 10 and 40 Gbit/s. At 10 Gbit/s, the format adaptation allows for a very high pulsewidth increase, i.e., from 10 to 100 ps. The output 10 Gbit/s NRZ signal is transmitted on metro-like links with no chromatic dispersion compensation.      

全光网络中光通道连接的分布式管理

在全光通信网络中,光通道连接是透明的,可以承载不同格式和速率的信号.着重研究全光网络中光通道连接的控制机制,提出了波长路由光网络的分布式控制方案,从而实现光通道连接的可靠建立和拆除.     

全光网络中光通道连接的分布式管理

全光通信网络中 ,光通信连接是透明的 ,可以承载不同格式和速率的信号。文中着重研究全光网络中光通道连接的控制机制 ,提出了波长路由光网络的分布式控制方案 ,从而实现光通道连接的可靠建立和拆除。     

基于MPLS的虚拟专网在光网中的实现

本文在论述虚拟专网发展演讲过程的基础上,对基于多协议标记交换的第二层虚拟专网的 关键技术和实现进行了论述,进而对基于多协议标记交换机制的虚拟专网在光网络中的实现机制进行了深入分析。     

光网络的动态特性与可扩展性

光网络正从静态光网络逐步演进为动态和智能的光网络,在演进过程中,光网络的动态特性越来越重要。一些可行的控制管理算法、策略和信令方法在网络规模扩大之后性能会严重恶化,因此光网络的可扩展性越来越受到研究者的重视。动态特性和可扩展性都是网络发展的需求,然而二者在存在一定的相互制约,通过建立分层分域的机制可以有效的环节这种制约,为实现动态特性良好、智能化程度高同时可扩展的光网络提供了可能。     

无源光网络可靠性分析

简要讨论了网络可靠性的定义,研究了无源光网络(PON)树型、总线型、环型、树/冗余型等四种典型拓扑结构,分别建立了模型,并给出了其可靠度计算式,最后对其可靠性进行了定性对比分析。     

采用光突发交换技术组建动态光虚拟专用网

光突发交换是光路交换和光分组交换的一个有效折衷方案，避免了两者的缺点，能很好的适应未来业务量爆炸式增长及业务的多样性和多变性的要求。光虚拟专用网业务使得企业能够在公网内部灵活地组建自己的网络拓扑，避免支出建设专用网络的学生费用，同时使得运营商优化带宽的利用率，通过较少的投资获得更多的商业机会从而增加收入，把OBS技术应用于OVPN网络将使其具有更大的灵活性，安全性和可扩展性。这里介绍了OBS原理和功能，阐述了OVPN体系结构及参考模型，对采用OBS技术组建动态OVPN进行了探讨性研究。     

Scalability of Wavelength Division Multiplexed Optical Passive Star Networks with Range Limited Tunable Transceivers

The number of stations attached to a single optical passive star is limited by current state of the art in optical technology. Also, the wavelength range of tunable optical transceivers is limited by current technology. Many high performance computing applications require the use of large size regular topologies for communication between computing nodes. Scalability of passive star networks built with these two limitations becomes an important issue for building larger networks. This is the subject of our study in this paper. In a previous related work we explored the design issues for networks built on a single passive star employing transceivers of a limited tuning range. Here we extend that study by considering the problem of connecting several optical passive stars, each embedded with a given virtual topology, to create larger aggregate networks. The design issues are analyzed and a number of design rules are proposed for building such aggregate networks. We study the scalability of embedded optical passive stars by considering the most commonly employed virtual topologies—complete graph, mesh and hypercube.     

以太网无源光网络的服务质量分析

以太网无源光网络正成为当前光接入网研究的热点课题．本文重点研究了服务质量问题。在分析EPON系统QoS问题的基础上，利用优先级排队理论对基于QoS的DBA算法的性能进行了理论分析，指出DBA算法进一步优化的方向。     

在SDON中面向成本优化的虚拟光网络映射方法

结合软件定义光网络和光网络资源虚拟化的技术背景,对虚拟光网络成本优化问题进行了深入研究。在软件定义光网络中采用软件定义光网络基础服务架构和网络资源抽象的虚拟光网络服务架构,通过引入虚拟光网络的映射模型,提出了虚拟光网络映射策略和虚拟光网络协同映射规划方法,解决了面向成本优化的虚拟光网络映射方法,可为未来光网络虚拟化技术的应用提供技术支撑。     

光虚拟专用网技术的研究

介绍了OVPN体系结构及参考模型,阐述了供应商提供OVPN所需要的关键技术和各方面要求,最后分析了智能光网络对OVPN服务的支持。