中国固定网络运营商建设NGN的状况和策略分析

1 NGN定义。NGN(下一代网络)是指：在一个统一的分组网络上提供语音、数据、多媒体等业务的网络。在中国，NGN主要指以软交换为核心技术并基于包交换的通信网络。软交换技术通过软件实现基本呼叫控制功能，包括呼叫选路、管理控制、连接控制(建立／拆除会话)和信令互通等。     

下一代网络NGN及其研究进展

下一代网络（NGN）是可以在电信网、计算机网和有线电视网3种互联互通的网络上提供语音、数据、视频的新一代网络，它实现了业务与网络的分离，并采用开放的体系结构，使NGN能够提供丰富的多媒体业务，NGN时代的到来也就成为电信网络发展中的一座重要里程碑。     

基于ASN.1的NGN测试系统INAP模块的研究与实现

INAP模块是NGN网络测试仪中针对智能网进行测试的部分，文章基于ASN．1的INAP协议编码规范，采用面向对象设计方法，实现了运用于NGN网络测试仪的INAP模块解码和合成功能，介绍了设计方案和实现方法。本方案经过测试，效果良好，符合实用要求。     

NGN及其关键技术探讨

NGN是一种综合、开放的网络架构,提供语言、数据和多媒体等业务。NGN通过优化网络结构,不但实现了网络的融合,更重要的是实现了业务的融合,使得分组交换网络能够继承原有电路交换网中丰富的业务功能,同时可以在全网范围内快速提供原有网络难以提供的新型业务。主要介绍了NGN的概念与体系架构,叙述了NGN涉及的主要技术及优势,并对NGN进行了展望。     

知新篇之NGN的发展趋势和创新

NGN的未来发展趋势着眼于三个方面，即业务、网络控制层、用户业务体验等。 NGN是多媒体化的业务，不仅仅是数据多媒体的单个业务多，而应该是话音、数据等综合业务在NGN网络上提供。同时，互联网业务和电信业务也将彼此渗透和融合。这可能将是NGN整个业务提供的一个亮点。     

下一代网络业务架构的探讨

随着网络技术的飞速发展,原有的网络已不能满足用户的需求。以软交换设备为核心,能够提供话音、视频、数据等多媒体综合业务,采用开放、标准的体系结构,能够提供丰富业务的下一代网络(NGN)应运而生,且一度成为人们关注的热点。文章通过对NGN业务演进策略的分析得出NGN业务架构应满足的性能要求,然后根据现有的各项NGN业务技术构建了NGN业务架构,实现了传统电信业务和Internet业务的融合。     

下一代网络中的软交换技术

１软交换的定义随着计算机和通信技术的不断发展，在一个公共的分组网络中承载话音、数据、图像已经被越来越多的运营商和设备制造商所认同。在这样的业务驱动和网络融合的趋势下，诞生了下一代网络（NGN）模型，实现于分组网络中，采用分布式的网络结构，能够有效地承载话音、数据和多媒体业务。作为NGN的核心技术，软交换的发展越来越受到关注；作为NGN的控制功能模块，软交换技术能够为NGN具有实时性要求的业务提供呼叫控制和连接控制功能。我国信息产业部电信传输研究所对软交换的定义是：“软交换是网络演进以及下一代分组网络的…     

融汇贯通的上海贝尔阿尔卡特NGN解决方案

作为中国NGN领域的领跑，上海贝尔阿尔卡特早在1998年就开始了NGN下代网络技术的研究、产品开发和相关标准的制定工作，它还是阿尔卡特集团全球NGN三大研发中心之一和亚太地区NGN技术支持中心。上海贝尔阿尔卡特的NGN解决方案目前已经为亚太地区的8个运营商提供了NGN解决方案。该“融汇贯通”的下一代网络具体而言，“融汇贯通”在于：融合全球领先技术、经验和本土化优势；汇聚固定、移动、数据等多种网络，     

面向下一代网络测试解决方案——HyperMetrics系列

随着语音、视频、数据及多媒体业务基于IP的应用大量增长,Internet所承载的业务和流量日趋庞大和复杂,这给IP技术及Internet网络带来前所未有的机遇与挑战。同时,电信业务的增长及赢利模式的多样化也催生了对于下一代网络NGN的迫切需求,下一代网络旨在建立一个全新的网络架构,以解决NGN向IP技术迁移过程中的业务融合问题,包括固网、移动、多媒体业务等,最终实现全网IP化。思博伦通信周启玄所撰《面向下一代网络测试解决方案——HyperMetrics系列》一文介绍了思博伦通信最新推出的高密度、高性能的以太网测试模块——HyperMetrics系列。思博伦面向下一代网络测试解决方案为测试人员提供多重业务应用、真实性、可扩展性的从接入层到应用层测试,并提供极高的性价比,以符合不同厂商的测试需求,具有很好的参考意义。     

移动和固定NGN融合的趋势和进程分析

近两年来,PSTN向NGN的发展成为业界探讨的热点,设备制造商如国内的中兴、华为,国外如爱立信、朗讯等知名厂商纷纷展示自己的NGN解决方案,国际电信运营商正在逐步开展以软交换为核心的NGN商用网络部署,中国电信、中国网通等也纷纷启动NGN的试验网测试工程,从而揭开了传统的PSTN向NGN演进的序幕。NGN基于软交换的控制体系可以实现业务的灵活性,基于IP的交换体系可以实现多种业务的融合,是实现三网融合的基础。从网络运营和竞争的角度来看,由于NGN可以实现比较低的固定资产投资和更低的运营成本满足未来对迅速部署和提供多样化业…     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.