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.     

3n?1级混洗交换网络的重排性研究

可重排性是混洗网络研究和应用的核心问题,针对当前n>4的混洗交换网络尚无实用的重排解决方案这一现实,提出了3n-1级Omega网络的重排性实现策略。该策略将无冲突路由确定问题解析为路由入线重组和路由序列分解问题,给出了通过冲突节点调整与路由无冲突扩充重组入线的方法。对于路由无冲突扩充,不仅从理论上证明了其可行性,并给出了具体的扩充算法,首次解决了n=5时Omega网络的重排性实现问题。如果关于路由序列分解的Ge猜想能以构造性方法获证,那么,策略将彻底解决3n-1级Omega网络的重排性实现问题。     

开关电容网络的广义节点故障诊断及可诊断性

本文首次引入了开关电容网络广义节点故障诊断的概念,提出了一个简单、准确、有效的算法,并着重强调了应用广义节点概念的优点。本文还探索性地研究了开关电容网络的可诊断性,并给出了可诊断性的必要条件。     

基于资源利用率的可重构无源光通信网络

为了提升网络带宽容量、降低网络时延,提出基于资源利用率的可重构无源光通信网络。通过可重构平台的网络管理构件、数据采集构件、P2P重定向构件共同配合,建立可重构无源光通信网络,依据可重构无源光通信网络层间信息互通特点,在网络物理层上添加MAC层,设计基于MAC-RPON层的资源分配模型,MAC层依据用户队列内调度事宜轻重程度,将所有队列数据包按照优先级别排序,物理层通过可重构无源光通信网络的准入、带宽分配和频谱分配三个步骤,将子载波合理分配给每个用户。实验分析表明：所研究网络可有效完成资源分配,且网络带宽容量大,更好地满足资源合理利用需求;网络平均队列长度短,资源分配时延低、效率快,有效提升网络资源利用率。     

一种可部署在重路由光网络中实现有效连接管理的策略——基于分布式代理与蚁群算法

在大型骨干光网络中, 建立一条从源节点到宿节点的路由至关重要。在集中式网络管理系统体系下, 网络中动态路由信息以及故障状态信息, 通过路由的“泛洪”机制, 被传送到其他节点上实现资源信息共享,这对于连接的迅速建立, 恢复路由的快速启动将是不利的。尝试采用一种启发式算法-蚁群策略, 快速提高光网络中故障恢复的速度。该路由算法平台采用了分布式蚁群算法自动修复故障点, 解决了重路由的快速收敛问题; 依靠分布式代理机制构建管理平面和数据平面相互通信的机制, 完成诸如链路信息素的更新等功能。设计了一个网络故障的场景, 通过实验数据表明, 采用蚁群的分布式路由策略, 可以更快地实现路由信息的汇聚, 找到最佳的恢复路由。     

Design and implementation of a scalable switch architecture for efficient high‐speed data multicasting

This paper presents the design and implementation of a new scalable cell‐based multicast switch fabric for broadband communications. Using distributed control and modular design, the multicast balanced gamma switch features a scalable, high performance architecture for unicast, multicast and combined traffic under both uniform and non‐uniform traffic conditions. The important design characteristic of the switch is that a distributed cell replication function for multicast cells is integrated into the functionality of the switch element with the self‐routing and contention resolution functions. Thus, no dedicated copy network is required. In the paper, we discuss in detail the design issues associated with the multicast functionality of the switch using 0.18 µm CMOS technology and discuss the scalability of the switch in terms of architectural, implementation, and performance scalability. Synthesized results are provided for measures of circuit complexity and timing. Copyright © 2006 John Wiley & Sons, Ltd.     

一种简单路由算法下的全互连立方体网络性能分析

本文研究在一种简单路由算法条件下全互连立方体网络(FCCN，Fully Connected Cubic Network)的性能。研究结果表明在应用简单路由算法的条件下，至少在80％以上的情况下可以得到最短路径，而且这个比例是随着网络规模的扩大而增大的，进而得到网络最大结点间距离和平均结点距离的公式，而且网络性能在通信局部性的条件下可以显著提高。计算结果证明FCCN在信息局部性系统中具有比较高的并行处理效率。     

电信网管开发平台分析

电信管理网（ＴＭＮ）是现代电信网络的一个重要组成部分。鉴于国内对符合ＴＭＮ国际标准的网管开发尚处于刚刚起步,本文分析各主要网管开发平台的功能特点。并对各集成环境作剖析和比较,以期有助于推进国内电信网管系统的设计和开发。     

有旋转连接的双层光互连网络设计与分析

设计一个具有旋转连接功能的双层并行光互连网络。顶层为数字路由结点(DRN)和光网络接口卡(ONIC)组成的星型网,吞吐率大于10Gbps;底层为ONIC连接而成的环形网,峰值传输速率1．056Gbps。光纤旋转连接器(FORJ)的引入增加了网络的灵活性和使用范围。该网络的最大吞吐速率为8．448Gbps;环网内平均延迟2195ns,环网间平均延迟4713ns,误码率小于10^-14;结点机之间的链路长度最大可达5．46km。     

Performance Evaluation of a New MAC Protocol for the CDMA Interconnection Network

A CDMA mobile system consists of subsystems that transmit and receive call control messages and traffic messages through the CDMA Interconnection Network (CIN). To assure high throughput and short delay in the CIN, an efficient Medium Access Control (MAC) protocol should be provided.In this study, we propose a new MAC protocol for CDMA interconnection networks in order to provide real-time communications in CDMA mobile systems. Also, we evaluate the delay performance of the proposed MAC protocol and compare it with that of existing MAC protocol. Through numerical examples, we show that the proposed protocol provides better delay performance than the existing protocol.     

分组无线网网络管理代理端的MIB开发及其存取实现

研究了分组无线网网管代理端的MIB的开发,并实现了对MIB的存取。     

下一代网络（NGN）的发展及其与IPv6的关系

下一代网络NGN是当今的研究热点，而作为与NGN发展密切相关的IPv6，将采必将取代IPv4。从NGN的概念出发，着重介绍了下一代网络（NGN）的网络结构、特点以厦现阶段发展状况和今后发展趋势，并对NGN与Ipv6的关系以及IPv6在NGN中应用的场景进行了详细的探讨。     

An analytical approach to the performance evaluation of the balanced gamma switch under multicast traffic

This paper presents the performance evaluation of a new cell‐based multicast switch for broadband communications. Using distributed control and a modular design, the balanced gamma (BG) switch features high performance for unicast, multicast and combined traffic under both random and bursty conditions. Although it has buffers on input and output ports, the multicast BG switch follows predominantly an output‐buffered architecture. The performance is evaluated under uniform and non‐uniform traffic conditions in terms of cell loss ratio and cell delay. An analytical model is presented to analyse the performance of the multicast BG switch under multicast random traffic and used to verify simulation results. The delay performance under multicast bursty traffic is compared with those from an ideal pure output‐buffered multicast switch to demonstrate how close its performance is to that of the ideal but impractical switch. Performance comparisons with other published switches are also studied through simulation for non‐uniform and bursty traffic. It is shown that the multicast BG switch achieves a performance close to that of the ideal switch while keeping hardware complexity reasonable. Copyright © 2006 John Wiley & Sons, Ltd.     

Polymer 1×2 Thermo‐Optic Digital Optical Switch Based on the Total‐Internal‐Reflection Effect

This letter presents a polymer 1×2 thermo‐optic total‐internal‐reflection digital optical switch (TIR‐DOS) with an index contrast of 1.5%‐Δ operating at low power consumption. The structure of our 1×2 TIR‐DOS was created by adding a reflection port to that of a conventional multimode filtering variable optical attenuator. To improve the total‐internal‐reflection efficiency, a heater offset was applied to the crossing region of multimode waveguides of the TIR‐DOS. The fabricated 1×2 TIR‐DOS shows a low electrical power consumption of 18 mW for an on‐off ratio of 35 dB.