高速路由器上基于区分服务的QoS解决方案

本文提出了一种高速路由器上基于区分服务的QoS解决方案，克服了IntServ方案的扩展性差、实现复杂的缺点．适合主干网的使用。该方案利用相对简单的方法将数据流分类、聚合，同时将QoS参数应用于这些类别．再和高速路由器中定义好的PHB相结合。就可以为任意一个报文提供可扩展的端到端的QoS。     

基于链路资源改进RED算法研究

Internet上随着网络的不断发展和用户的要求越来越高,以为用户提供更高服务质量（Quality of Service,QoS）为目标的研究越来越重要。而强壮的网络拥塞控制是保障用户服务质量的基础。“随机早期检测算法”（Random Early Detection,RED）[1],由于其在实际应用的广泛,成为研究热点。文章首先探讨远端流和近端流在在传输过程中的不公平性和链路资源利用情况,在此基础上提出路由器将网络中的流分为远近两种区分对待,改进RED算法以提高链路资源的利用率和流在传输过程中的公平性。     

一种基于QoS特征的多媒体业务区分方法

准确、高效的业务流识别和分类是保障多媒体通信端到端服务质量(Quality of Service,QoS)和执行相关网络操作的前提。但多媒体通信业务构成复杂,具有较严格的QoS约束,且存在包/流水平统计特征多样性,因此业务统计特征有效选取直接关系到识别和分类方法的有效性。针对流行的多媒体业务,分析了典型的业务特征,从业务QoS保证角度,选取区分特征,基于隐马尔可夫模型(Hidden Markov Model,HMM),对多媒体业务在QoS类上进行区分,实现简单,能以较小的空间复杂度较快地识别出多媒体业务流,有利于提高分类准确度。通过仿真验证了该方法的有效性。     

各标准组织QoS分类和DiftServ业务类别的映射

建立合理的业务分类模型是解决下一代网络服务质量（QoS）的关键问题之一，本分析了国际上各电信组织提出的QoS分类方法，并分别与Diffserv的区分业务进行了映射。建立一个具有通用性的业务分类模型。     

高速 智能 NETGEAR千兆无线宽带路由器WNR3500

NETGEAR即将在国内上市的千兆无线宽带路由器WNR3500内置的8根天线，可实现比标准802．11g高达15倍以上的速度和12倍以上的覆盖范围，保证了冲浪、邮件、高清视频流和在线游戏等多种应用同时流畅进行。WNR3500具备智能QoS网络服务质量控制功能和一键加密（WPS）功能，     

NGN承载网的QoS

在IP分组交换网上实现业务的端到端QoS可以采取如下阶段性方案：①基于区分服务（Diff－Serv）或ToS；②基于尽力而为（Best－Effort）的流量工程；③基于Best－Effort的流量工程＋Diff－Serv或ToS；④基于Diff－Serv的流量工程，结合快速重路由等技术对实时业务的支持，有望达到电信级QoS。１．QoS的分层实现下一代网络（NGN）业务要求端到端的QoS保证，这就需要整网设备的支持。目前采用Diff－Serv模型更符合城域网的现状，要求城域承载网转发设备（二层／三层交换机、宽带接入服务器（BAS）、路由器）及NGN部件（软交换、…     

IP分类技术研究

网络应用的发展要求路由器必须有能力支持防火墙、QoS、流量计费等一系列功能.这就要求路由器对IP包进行分类,根据分类结果完成对数据包的不同处理.本文全面地介绍了IP分类技术研究的最新成果,以及IP分类的典型算法.最后本文对其中三种典型算法在虚拟环境下做了评测,比较了它们的优缺点.     

IPv6网络实现QoS路由的障碍和解决思路

大容量内存、高速CPU及接口的IPv6路由器支撑下的QoS路由是解决IPv6 QoS问题的一项关键技术.针对适应于IPv6网络环境的QoS路由成果为数不多的现状,本文分析了IPv6在实现QoS路由的过程中可能会遇到的障碍,挖掘了IPv6如何利用其简化报头、流概念、流量类型和流标签域支持QoS路由的潜能,提出借助IPv4 QoS路由研究的基础,兼容BE（best effort）路由和对现有路由体制改动小的、逐步演进的IPv6 QoS路由实现策略和扩展IPv6及其主流OSPFv3路由协议,改进算法的整体思路.最后指出为推动IPv6 QoS路由从理论研究走向实际应用还需加强的研究方向.     

DiffServ与SNMP结合实现IPv6网络QoS的新机制

文章介绍了简单网络管理协议(SNMP)模型和区分服务(DiffServ)模型的基本原理.SNMP模型放置了一个视频点播服务(VOD Server)客户端和一个带宽控制管理(BCM)服务器.在VOD Server上安装有Agent软件,主要用于申请带宽,而将BCM作为系统的核心.DiffServ模型在边缘路由器上装有分类器和调节器,主要负责驽对数据流进行分类、标记和整形;内部路由器只负责转发.文章实现了DiffServ与SNMP相结合的端到端的IPv6服务质量(QoS)的新机制.     

IP骨干路由器的CoS功能

新的IP应用（如实时的视频和音频应用）的开发和普及,对网络提供的服务提出了更高的要求,网络必须能够对用户信息流进行分类,并对不同类的信息流提供不同的服务特性,这就要求IP骨干路由器具有CoS（服务分类）功能,本文以Juniper Networks公司的M系列路由器为例,简单介绍了目前普通IP骨干路由器所具有的CoS功能。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks