一种新型光交换网络的流量特性分析和传输机制研究

阐述了可以弥补光电路交换和光突发交换二者缺点的混合交换技术,提出了一种采用混合交换技术的新型光交换网络,分析了该新型网络中的流量特性并提出了与该网络相应的传输机制.实验表明,采用该传输机制的新型光交换网络,在源负载低于0.75的情况下,其网络丢包率和吞吐量等性能均优于普通混合交换网络,能达到优化网络资源的目的.     

神经网络在交换中的应用

介绍神经网络在交换网络中的两种可能的应用,即应用神经网络解决重排列交换网的重排问题和应用神经网络解决多级大交换网的寻找路由问题。     

一种新型模块化内部无阻塞的自选路由ATM交换网络

为了提高ＡＴＭ交换网络的并行处理能力以适应ＡＴＭ交换机高速传输链路的要求，在中大规模ＡＴＭ交换机中普遍采用内部无阻塞的自选路由ＡＴＭ交换网络。目前满足这一要求的传统交换网络结构Ｂａｔｃｈｅｒ－ｂａｎｙａｎ网。由于Ｂａｔｃｈｅｒ－ｂａｎｙａｎ网络中的Ｂａｔｈｅｒ排序网络不能进行模块化扩充，因此Ｂａｔｃｈｅｒ－ｂａｎｙａｎ网络在大规模ＡＴＭ交换机中的应用仍然受到一定的限制。针对这一问题，本文提出了一种新型模块化内部无阻塞的自选路由ＡＴＭ交换网络——内嵌ｂａｎｙａｎ网（ＮＢＮ，ｎｅｓｔｅｄｂａｎｙａｎｎｅｔｗｏｒｋ）。ＮＢＮ与传统的Ｂａｔｃｈｅｒ－ｂａｎｙａｎ网相比，有很强的模块化扩充能力和较小的处理延迟，对于中大规模ＡＴＭ多级互联交换网络的设计和实现有较高的研究价值。     

光子交换网络实现三重分割复用的图表分析法

提出用连接逻辑图描述由单一的空分交换网络等价变换为三重分割复用光子交换网络的图解分析法，并具体讨论了一种基于Ｂｅｎｅｓ结构的８×８空分多级光子交换网络实际的拓扑变换过程。     

无阻塞大容量时隙交换网络的实现

介绍MT9080和MT9085的结构与功能,叙述由MT9080及MT9085组成的1024×1024和2048×2048无阻塞大容量时隙交换网络的电路和工作原理,简述MCS—96单片机与交换网络的接口,给出了8192×8192交换矩阵的框图。     

在7级混洗交换网络中实现16×16的可重排性

长期以来,人们猜想(2n-1)级的均匀混洗交换网络Ω对置换2^<em>n×2^<em>n是可重排的.若干论文企图从理论上给出其充分性证明,但都没有成功,包括最近的一次证明^[24],仍然是错误的,但还没有人指出.本文的目的之一是澄清这一点.当n=3时已有学者给出了证明 .本文针对n=4时的7级Ω网络,给出了实现16×16可重排性的构造性证明.论文提出了避免内部冲突的平衡树模型,置换的连接图、回路图表示和对称图形、同解变换等概念,并基于图形压缩、图形剖分等方法,将16×16置换分为五种情况,共给出五种赋值算法.这些算法比较简洁,易于编程实现.本文提出的思想对研究高阶网络的可重排性也有一定参考价值.     

航电FC交换网络可靠性建模与仿真研究

针对典型航电FC交换网络的架构,综合考虑了节点、交换机整体故障和各个端口独立故障对网络可靠性的影响差异以及多种余度数量的分析需求,建立了节点、交换机和链路故障模型、端口-端口网络故障模型以及节点-节点网络故障模型,提供了一种基于矩阵的直观建模思路;给出了基于仿真的故障样本生成方法和网络可靠性计算方法,并结合案例对航电FC交换网络的可靠性进行了定量分析,以上模型和方法可为航电FC交换网络的可靠性设计提供理论数据支持。     

智能化双交换端口电路

(一)概况 S1240数字程控交换机是全分散控制,其核心是数字交换网络。它连接各终端模块,在模块间传送话音或控制信号。数字交换网络的交换与维护过程不受微处理机控制,完全由交换网络内部硬逻辑DUSP(Dual Switch Port)实现,因而它是一个智能化的数字交换网络,主要特点是:(1)可选择最短时延的任意端口、任意话路;(2)话路阻塞(NACK)时,自动拆除,并回送塞地址给终端模块;(3)网络故障可自动告警(话路零);(4)可查询网络的状态和已建立的话路的地址。数字交换网DSN(DIGITAL SWITCH NET-WORK)由许多相同的交换单元DSE(DIGITALSWITCH ELEMENT)组成,根据交换局的大小,配     

民族通信产业之窗

我国交换技术获重大突破中兴通讯研制出64kB×64kB交换网板深圳市中兴通讯股份有限公司传来喜讯，该公司甫京研究所成功研制开发出64kBX64kB交换网板。此项技术是我国电路交换技术的一项重大突破，标志着民族通信设备制造商已完全掌握了电路交换技术，并在窄带交换设计技术领域达到了世界领先水平。此前，业界容量最大的交换网板仅为16kBXI6kB。由于单T结构的交换网络比多级交换网络具有不可比拟的优点，因此设计出一种结构简单的单T大容量交换网络一直是该领域研究专家追求的目标。但是，大容量的单T交换网板技术实现难度非常高。中兴…     

在7级混洗交换网络中实现16×16的可重排性

长期以来,人们猜想(2n-1)级的均匀混洗交换网络Ω对置换2n×2n是可重排的.若干论文企图从理论上给出其充分性证明,但都没有成功,包括最近的一次证明[24],仍然是错误的,但还没有人指出.本文的目的之一是澄清这一点.当n=3时已有学者给出了证明[1,2].本文针对n=4时的7级Ω网络,给出了实现16×16可重排性的构造性证明.论文提出了避免内部冲突的平衡树模型,置换的连接图、回路图表示和对称图形、同解变换等概念,并基于图形压缩、图形剖分等方法,将16×16置换分为五种情况,共给出五种赋值算法.这些算法比较简洁,易于编程实现.本文提出的思想对研究高阶网络的可重排性也有一定参考价值.     

新桥DDN网管系统的路由功能

介绍了天津DDN本地网网管系统的路由功能,其中引入了“域”的概念。     

自由空间二维榕树网实现方法

鉴于榕树网在自由空间光子交换网络中具有重要的应用价值,分析了榕树网的特点和4×4二维榕树网的空间拓扑结构,通过偏振光分光棱镜、微闪耀光栅阵列、平面反射镜、半反半透镜和液晶空间光调制器的集成,构建二维的榕树交换网实验模块,利用微闪耀光栅的衍射特性,控制每块微闪耀光栅的周期,以实现入射光信号不同方向的闪耀输出,最终完成二维榕树网自由空间水平和竖直方向上的交叉互连,直通则由平面镜反射实现。对二维榕树网实验模块的功能分析表明,该实验模块理论上可以完成4×4二维面阵内光信号(或数据)的排序、交换、组播、广播、矩阵变换等操作,具有交换透明、速度快、空间带宽高等特点,在全光交换和光通信中具有一定的应用。     

全交叉开关网络中四功能开关节点的实验研究

提出了一种基于全交叉开关网络的电寻址四功能多量子阱开关节点方式。采用２个１×８非对称Ｆａｂｒｙ－Ｐｅｒｏｔ胜多量子阱反射调制器列阵构成４对电寻址四功能多量子阱开关节点，实现了Ｎ＝８时全交叉开关网络第一级的开关结点功能，并给出了光学系统和实验结果。     

Parallel routing algorithms in Benes-Clos networks

A new parallel algorithm for route assignments in Benes-Clos (1962, 1953) networks is studied. Most known sequential route assignment algorithms, such as the looping algorithm, are designed for circuit switching systems where the switching configuration can be rearranged at relatively low speed. In packet switching systems, switch fabrics must be able to provide internally conflict-free paths simultaneously, and accommodate packets requesting connections in real time as they arrive at the inputs. In this paper, we develop a parallel routing algorithm for Benes networks by solving a set of Boolean equations which are derived from the connection requests and the symmetric structure of the networks. Our approach can handle partial permutations easily. The time complexity of our algorithm is O(log/sup 2/ N), where N is the network size. We also extend the algorithm and show that it can be applied to the Clos networks if the number of central modules is M=2/sup m/, where m is a positive integer. The time complexity is O(log N/spl times/log M) in this case.     

Macromodeling of nonlinear digital I/O drivers

In this paper, a modeling technique using spline functions with finite time difference approximation is discussed for modeling moderately nonlinear digital input/output (I/O) drivers. This method takes into account both the static and the dynamic memory characteristics of the driver during modeling. Spline function with finite time difference approximation includes the previous time instances of the driver output voltage/current to capture the output dynamic characteristics of digital drivers accurately. In this paper, the speed and the accuracy of the proposed method is analyzed and compared with the radial basis function (RBF) modeling technique, for modeling different test cases. For power supply noise analysis, the proposed method has been extended to multiple ports by taking the previous time instances of the power supply voltage/current into account. The method discussed can be used to capture sensitive effects like simultaneous switching noise (SSN) and cross talk accurately when multiple drivers are switching simultaneously. A comparison study between the presented method and the transistor level driver models indicate a computational speed-up in the range of 10-40 with an error of less than 5%. For highly nonlinear drivers, a method based on recurrent artificial neural networks (RNN) is discussed.     

A fault-tolerant switching network for B-ISDN

The author proposes a self-routing fault-tolerant switching network for asynchronous transfer mode (ATM) switching systems. The network has many subswitches to enhance the fault tolerance of the conventional multistage interconnection network which only has a unique path. The subswitches provide large numbers of alternative paths between switching stages and allow the network to tolerate multiple paths. The routing algorithm is quite simple. The paths can also be used to route cells under the condition that internal cell contentions occur in switching elements. A reliability analysis shows a quantitative measurement of the improvement in fault tolerance as compared with previously presented fault-tolerant networks. A performance analysis and simulation results show that the proposed network has a high level of maximum throughput. In addition, that level of throughput is maintained with reasonable cell delay even though the number of faulty components increases in the network     

OBS网络中的多BHP延迟调度算法

光突发交换 (Optical Burst Switching,OBS) 是下一代光网络中的有效核心交换技术之一。在OBS网络中,核心节点的调度方案是影响网络交换性能的重要因素。如何有效地对突发分组 (Burst) 进行合理调度,以减少丢包率正是关键问题所在。该文提出了一种多控制分组 (Burst Header Packet,BHP) 延迟调度算法,对于一个收集周期内到达的多个BHP所对应的突发数据,按照一定的方式对它们进行集中调度,实现对已预约资源的更改,使调度结果得到了优化。该算法根据不同的网络应用,可细化为4种具体的算法实现,以适用于不同的应用场景。仿真结果表明,该文提出的调度算法和已有算法相比,能够优化对突发分组的调度,提高对信道资源的有效使用,从而降低交换网络的丢包率。     

Macromodeling of nonlinear transistor-level receiver circuits

In this paper, a modeling methodology for macromodeling transistor-level receiver circuits has been presented. A few receiver modeling techniques have been proposed in the past, but these modeling techniques only address the loading effect of the receiver circuits, i.e., the input characteristics of the receivers. In this paper, a modeling methodology that addresses both the loading effect as well as the output characteristics of the receiver has been proposed. This modeling technique is simple, accurate, and has huge computational speed-up over transistor-level receiver circuits. To model the input characteristics of the receiver, spline function with finite time difference (SFWFTD) and recurrent neural network (RNN) modeling methods have been used. The output characteristics of the receiver are modeled using a combination of receiver static characteristics and a delay element that takes into account the timing delay of the receiver. The accuracy of the modeling approach has been tested on some test cases and results show good accuracy and substantial speed-up compare to transistor-level receiver circuits. The proposed modeling technique has been extended to multiple ports to estimate sensitive effects like simultaneous switching noise (SSN) when multiple receivers are switching.     

A survey of data multicast techniques, architectures, andalgorithms

This article presents a survey of architectures, techniques, and algorithms for multicasting data in communication switching networks. We start with a broadcast architecture using a separate copy network and a routing network. A few versions of this idea using Delta and Benes networks exist. Another multicast architecture is a recycling network where internal nodes act as relay points, accept packets from the switching fabric, and recycle them back into the fabric after relabeling the packets. Next, we give an overview of a system that uses the Boolean splitting multicast algorithm. In this system a nonblocking self routing broadcast banyan copy network has been proposed. The network consists of several components including a running adder network to generate running sums of copy numbers specified in the headers of input packets. We then describe a multicasting technique presented for a different class of switching networks called deflection-routing networks. Finally, the idea of extending a nonblocking network to a three-dimensional structure consisting of multiple parallel planes is also presented. At the end of this article, we compare the efficiencies of the presented multicast architectures     

基于硅基光子学的2维相控阵真时延网络

为了实现大规模2维相控阵天线的光学真时延系统, 采用基于硅基光子学的二进制硅基集成二进制光延迟线技术, 提出一种2维相控阵(N×N)真时延网络, 利用2维相控阵结构的对称性以及行延迟和列延迟的独立控制, 真时延网络的复杂度可以降低至(N-1)/2(N为奇数)或N/2(N为偶数)。理论分析了该时延控制方案和集成时延芯片的设计, 以8×8的2维相控阵为例, 设计实现了包含4种硅基二进制时延线的真时延芯片, 测量了该芯片的时延量, 并针对测量的时延量仿真分析了2维相控阵天线的波束扫描特性。结果表明, 该真时延网络能够满足相控阵天线波束指向要求(角度误差小于0.5°); 集成光学技术的采用减小系统的体积和成本。该研究为大规模2维相控阵天线的真时延网络实现提供了一种可行的方法。