多波长光网络的动态路由等效算法

针对多波长光网络的特点，提出了一种动态路由和波长分配的等效算法。采用波长图、增加虚拟源节点和目的节点等技术，把多波长网络转化为等效的单波长网络，避免了求解路由和波长分配两个复杂子问题，简化了算法的程序设计。利用最短径算法进行路由和波长分配可以求得问题的最优解，从而有效地降低了网络阻塞率。仿真结果表明：与FAR-2D算法相比，在4和8波长的全波长转换网络中，采用等效算法阻塞率最大降幅分别达到0．02、0．025。     

波长路由在并行计算机光互连中的应用

提出了一种波长路由并行光互连技术，其路由直接在源端用目标地址选择波长来建立，各波长有独立传输路径并采用光通道复用，路由变换节点为全光结构，光信号在变换节点处无转发延迟。此技术可应用于并行计算机互连网络和分布式高性能计算机群的互连网络。     

基于波长移相干涉的台阶测量技术

概括了波长移相干涉技术的特点，将基于波长移相干涉技术的台阶测量算法分成两类：时域算法和频域算法。时域算法包括开瑞（Carre）算法和多波长组合算法等，频域算法包括基于时域傅立叶变换找基频算法、塔可达（Takeda）算法等，文中分析了这些算法在实际应用中需要考虑的技术问题，针对时频域算法特点，提出了基于时域傅立叶变换的差分算法，实验结果与分析证明这一算法的正确性和可行性。     

多纤多波长光网络的动态路由等效算法

针对多光纤多波长光网络的特点,提出了一种动态路由和波长分配的等效算法。采用波长图、增加虚拟源节点和目的节点、引入光纤数量矩阵等技术,把多纤多波长网络转化为等效的单波长网络,大大简化了算法程序的复杂度。采用最短径算法作为算法的基础,可求得每次业务在全网范围内的路由和波长分配的最优解。仿真结果表明,当网络呼叫量为60时,全波长转换情况下,2纤、4纤网络的阻塞率分别为0.1116、4.3×10-5。     

基于时域傅里叶变换的波长移相算法

基于傅里叶变换的波长移相算法，是基于时域傅里叶变换和差分技术来实现干涉图处理。这种算法主要用于实现较粗糙轮廓或台阶件的光学检测。介绍了该算法的中心思想，指出了已有的Takeda算法的缺点，提出了改进算法。叙述了新算法的实现过程并进行了误差分析，最后给出了实验结果。     

基于最小化波长需求的波长路由光网的优化设计

讨论了波长路由光网的资源优化设计问题,提出了一种新的整数线性规划（ILP）公式,用于解决波长通道（WP）和虚波长通道（VWP）的路由选择和波长分配问题,它的优化目标是最小的网络需求,以中国高速信息示范网（CAINONET）为例,分析了波长通道（WP）和虚波长通道（VWP）路由方案之间在波长需求方面的差别,同时还研究了网络波长重用度的问题。     

一种新型IP OVER WDM城域网的节点结构

提出了一种基于波分复用（WDM）,分组交换,副载波复用和波长变换技术的新型全光城域网节点结构,网络拓扑采用环形,网络节点采用可调输出固定输入的选波原则以利于数据的多重接入,副载波复用和基于级联半导体光放大器的波长变换,实现了射频副载波路由信息与基带IP数据包的同步复用和IP数据包的透明传输。     

双泵浦SOA四波混频效应全光波长变换的研究

本文报道了半导体光放大器 (SOA)在偏振方向相互垂直的双泵浦光作用下 ,利用其四波混频 (FWM )效应实现的全光波长变换实验 ,其变换效率和信噪比在很宽的调谐范围内较高并且基本稳定。     

一种基于EDFA+NDF的全光波长变换

针对目前全光波长变换大多是利用半导体光放大器来实现的现状,本文提出了基于掺饵光纤放大器(EDFA)和非线性色散光纤(NDF)的全光波长变换.该方法利用抽运光和信号光同时输入NDF中时,NDF中产生的四波混频效应(FWM)能有效的产生新的光波,从而实现全光波长变换.文中首先介绍了利用OptiSystem软件成功实现了全光波长变换的仿真,接着在实验室中通过利用掺饵光纤放大器以及G655实现了全光波长变换.获得了最高-16.7dB的变换效率.实验结果表明,无论是理论模拟还是在实验室均获得了清晰明显的波长变换波形.     

2.5GHz非归零码光脉冲的波长变换实验

报道了采用国产器件进行了中心波长为１．５５μｍ，重复频率为２．５ＧＨｚ的非归零码光脉冲基于半导体放大器的交叉增益调制的波长变换实验，波长变换距离２．７ｎｍ。     

部分波长光网络中的动态波长分配算法

为适应网络中不同服务质量（QoS）的光路建立请求具有不同的优先级的情况,提出了一种用于部分波长可变网络中支持QoS的动态波长分配算法。该算法对网络中的业务请求分高、低两个优先级进行处理。对于高优先级的光路建立请求,通过充分利用网络中已配置的波长转换器实时改变可用波长集,以降低高优先级业务请求的阻塞率。对低优先级的光路建立请求,只考虑所选路径的当前位置是否有波长转换器来改变可用波长集,保证了低优先级的光路建立请求速度。仿真结果表明,该算法既能保证较高优先级的光路建立请求具有较低的阻塞率,又充分利用了有限的网络资源,实现了对波长转换器的最优利用。     

稀疏波长变换的WDM光网络阻塞率的分析与计算

本文主要对具有稀疏波长变换的WDM全光网的阻塞率进行分析,首先提出一种模型分析了无波长变换器的L跳路径端到端阻塞率,接着对部分波长变换器的L跳路径的阻塞率进行求解,随后分析了全网的平均阻塞率。研究得到的主要结论是,波长变换器使用的有效性取决于网络的连接度。     

Dynamic O-band to C-band wideband wavelength converter for integrated VCSEL-based optical interconnects

ABSTRACT

Real-time wavelength conversion and traffic routing at key network nodes is a fundamental requirement for current optical interconnects. This work experimentally demonstrates a broadband wavelength conversion from O-band to C-band employing commercially available, power efficient VCSELs. A 1310?nm VCSEL is directly modulated with 8.5 Gbps data and transmitted over 22?km G. 652 fibre with a 0.53 dB penalty. The received data is used to run a 1550?nm VCSEL located at the network integration node, achieving the first reported wavelength conversion from O-to-C-band. VCSEL wavelength tuneability with changing bias current functionality is further exploited to route the converted wavelength over 400?GHz spectra range for integration into wavelength flexible networks. The newly converted wavelength is transmitted over 24.7?km of G. 655 fibre, incurring a maximum penalty of 1.86?dB. Results from this work proves an enabling development technology for wavelength converters for transparent contention resolution in current and future optical Interconnects.     

Selective assign shortest path first algorithm for routing and wavelength assignment in the presence of four wave mixing

The authors proposed a selective assign shortest path first (SASPF) algorithm for routing and wavelength assignment in the presence of four wave mixing (FWM) in wavelength division multiplexing network with a design parameter V_m. In order to maintain a reasonably good performance in terms of blocking probability to fulfil the connection requests but also to allow acceptable FWM effects, V_m is an important design parameter (number of established optical channels to fulfil the connection requests but also to allow acceptable FWM effects). If its value is too low, many connection requests will not be able to establish, which may lead to higher blocking probability. On the other hand, if its value is too high, it may lead to obvious FWM effects that will affect the network performance. Thus, V_m must be optimum to balance the requirement of the connection requests and also the induced FWM crosstalks. Performance results show that SASPF algorithm outperforms the comparison scheme such as traditional assign shortest path first resulting in low blocking probability with a specific value of V_m.     

Dynamic multicast routing and wavelength assignment using generic graph model for wavelength-division-multiplexing networks

The problem of dynamic multicast routing and wavelength assignment (MC-RWA) in the wavelength-routed wavelength-division-multiplexing networks is addressed. Current solutions to this problem always rely on homogeneous network constructions. However, future backbone networks tend to be heterogeneous in nature. Thus, the dynamic MC-RWA problem should be studied in a more realistic situation by considering the heterogeneity of network structures. A new graph model is proposed for the MC-RWA problem. This model is based on layered auxiliary graph which is generic and able to support various node architectures and heterogeneous network structures. Based on this graph model, the dynamic MC-RWA problem can be simply solved by an efficient multicast tree algorithm on various light-splitting and wavelength-conversion scenarios. In general, this graph model provides a universal platform to study different aspects of the dynamic MC-RWA as well as related problems.     

任意拓扑结构全光WDM网络中波长转换器配置的遗传算法

波长转换是应用在全光WDM网络中打破波长一致性约束、降低网络阻塞概率的一种有效技术,但限于波长转换器的高昂成本以及其对信号失真度的影响,目前还不可能为网络中的每个节点均配置波长转换器,所以波长转换器需要以最优方案配置在网络中的个别关键节点上,本文提出了一种在任意拓扑结构的网络中,基于遗传算法的波长转换器配置算法,并对该算法在NSFNET网络上进行了计算机仿真,模拟结果显示该算法非常有效.     

Genetic algorithm quality of service design in resilient dense wavelength division multiplexing optical networks

The important role of quality of service (QoS) in deployment of a resilient dense wavelength division multiplexing (DWDM) backbone for global networks requires critical design-phase planning optimisation. The design issues of resilient DWDM networks for bandwidth and delay sensitive applications of dedicated path protection are addressed. A genetic algorithm (GA) model has been developed to solve the routing and wavelength assignment problem using binary variable-length chromosome encoding under two different schemes of bandwidth optimisation (BOS) and delay optimisation (DOS).The performance of the new GA-based resiliency model has been evaluated for four benchmark networks: PAN EUROPEAN, COST239, NSFNETand ARPA2. Simulation results show a superior capability and efficiency for the model to solve this complex, multi-constraint and nondeterministic polynomial-hard problem for BOS and DOS. The nonlinear nature of this process reveals a significant sensitivity for optical layer network topology on the optimum-design QoS. The results also demonstrate that the PAN EUROPEAN network shows the highest flexibility for primary path design, NSFNET for the secondary path and ARPA2 comes with the lowest design flexibility for both primary and secondary paths.