基于ATM的宽带网络技术

随着科学技术的发展，ＡＴＭ技术已成为建造信息高速公路的关键技术之一，以ＡＴＭ为基础的宽带通信是网络发展的必然趋势。     

ATM网络技术在局域网中的应用

ＡＴＭ网络技术是宽带综合业务数字网络（Ｂ－ＩＳＤＮ）的关键技术，随着多媒体技术与多功能个人计算机技术的高速发展，促进了这一技术在计算机局域网络中的广泛应用，本文就ＡＴＭ网络技术在局域网中的应用进行详细综述。     

无线ATM网络的媒体访问控制（MAC）

宽带ＩＳＤＮ网络以及无线技术的迅速发展使得对无线ＡＴＭ网络的需求日益增加。本文介绍了无线ＡＴＭ网络的拓扑结构与用于无线网络的媒体访问控制方式，分析了现有的用于无线ＡＴＭ网络的ＭＡＣ的标准的现状，根据ＡＴＭ业务得出了无线ＡＴＭ媒体访问控制（ＭＡＣ）设计的探讨性的结论。     

ATM基本技术及其在公用网应用的主要难点

ＡＴＭ技术已被公认为实现宽带综合业务数字网（Ｂ－ＩＳＤＮ）的关键技术。本文将介绍ＡＴＭ技术的基本原理－ＡＴＭ概念，ＡＴＭ协议的分层结构，ＡＴＭ网络和接口，ＡＴＭ传输与复用技术，ＡＴＭ的交换技术，ＡＴＭ的信令方式，ＡＴＭ网络管理和管制以及ＡＴＭ技术在公用网应用中的主要难点。     

多业务宽带交换

分组化、宽带化、支持各种应用要求的统一网络是通信发展的共同目标。本文综述千兆比以太网，千兆比路由器网和ＡＴＭ网三种宽带网络技术，侧重介绍了基于多协议接口宽带分组交换技术的多业务宽带交换网。     

未来的宽带化网络

本文介绍了电信网在向Ｂ－ＩＳＤＮ发展过程中的四个阶段，构勒出电信网从引入ＳＤＨ传输系统，采用ＡＴＭ交叉连接技术，引入宽带交换，到实现宽带ＩＳＤＮ网络这四个不同历史时期的功能结构和特点，指出ＡＴＭ技术的引入为电信网提供了一个简易地，一致地处理所有类型信息的能力，从而实现了网络的综合化和宽带化。     

如何建设一个成功的ATM网络

目前，ＡＴＭ作为宽带交换技术已成为全球最引人瞩目的数据通信技术之一，国内电信行业ＡＴＭ网络的建设也如雨后春笋，不断涌现。然而究竟为什么要上ＡＴＭ？如何建设一个ＡＴＭ网络？怎样利用ＡＴＭ资源等？则众说纷纭，各持己见。本文试图就以上问题作一些探讨。１建设...     

宽带综合业务与ATM适配协议

宽带综合业务与ＡＴＭ适配协议沈雁蓉，丁炜一、ＡＴＭ技术及ＡＴＭ适配协议ＡＴＭ是一种快速分组技术，它是宽带综合业务数字网（Ｂ－ＩＳＤＮ）的核心。国际电联组织ＩＴＵ－ＴＳ在８０年代中期开始研究支持宽带业务的网络能力。它的目标是用统一的交换和传输技术来支持...     

宽带无线接入技术的探讨

一、引言异步传送模式（ＡＴＭ）作为宽带网络的核心技术,经过十多年的发展,已经不断地成熟,特别是在数据通信领域得到了不同程度的应用。近年来,许多机构开始致力于将ＡＴＭ技术拓展到无线网络,从而将ＡＴＭ特性应用于无线电媒体中。基于信元的宽带技术的应用以及它与当前最新的无线接入网的结合变得日益重要。在有线ＡＴＭ技术高速发展成为宽带核心技术之时,无线ＡＴＭ技术却刚刚起步,而且还有很多问题尚待解决,本文给出了宽带无线本地接人（ＷＷＬＡ）技术的发展概况,对其标准技术以及美国、欧洲和日本的宽带无线项目发展情况进…     

建设新一代宽带专用通信网

随着通信网络的宽带化、分组化演进以及光网络和光技术的不断发展 ,通信网主要业务也从单纯的语音向语音、数据和图像等多业务方向发展 ,而原有的基于ＴＤＭ技术建设的窄带专用通信网已越来越无法满足用户的需求 ,建设一个实用化的综合宽带通信网已成为摆在我们面前的迫切任务。１宽带网络的核心技术宽带网络建设模式一般有以下３种 :采用ＡＴＭ交换机建设ＡＴＭ综合业务宽带网 ;采用高速路由器建设ＩＰ宽带数据网 ;同时建设ＡＴＭ和ＩＰ两个网络。根据专用通信网主要满足行业内部通信的特点 ,同时建设ＡＴＭ网和ＩＰ网的可能性不大 ,一般根…     

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