NGN网络测试仪中No．7信令采集卡的研制

在NGN网络测试仪的开发中,No．7信令采集卡的研制非常关键,它是针对核心网测试最重要的采集卡之一。在本文中,介绍了No．7信令采集卡的设计方案,硬件设计与实现,及驱动程序的设计。经过现场测试表明,本文研制的No．7信令采集卡能够满足NGN网络测试仪现场采集数据的要求。     

基于TD-SCDMA标准的信令采集系统的设计及实现

信今数据采集是在TD-SCDMA网络测试仪中针对核心网测试最重要的数据种类的采集之一．文中详细介绍并且分析了大容量的信令采集系统的设计与实现，包括基于PCI总线的E1采集卡的硬件设计，工作原理，以及驱动程序的设计。该系统经多次现场测试，效果良好，符合测试的要求。     

ITU在NGN体系结构等方面的标准化进展情况

1概述鉴于NGN的研究在世界各国非常活跃,ITU-T作为ITUNGN研究的主导研究机构,在2004年6月的13组会议上组建了FGNGN(NGN专题组),以进一步加强和推动NGN的研究。NGN的目标是:在传输、业务和应用处于相互分离的前提下实现网络的互通,从而使其在全球范围内跨网络支持各种业务。在设计NGN的功能和体系结构时,必须满足NGN业务定义及规范方面和实际网络技术规范之间有明显界限的要求,即是一种与具体实施技术相独立的方案。NGN的业务体系必须具有如下特征:(1)分布式控制。适应IP网络分布处理的结构特点,消除依赖于传统No.7信令的结…     

No.7信令网络的维护和管理

No.7信令网是现代通信网的重要组成部分,它支持目前整个通信网的所有业务。我国采用的No.7信令网是具有多种功能的业务支撑网,并已建有一套较为完善的网络体系。论文从No.7信令网络结构出发详细介绍了我国目前对No.7信令网络的维护管理工作,比较了No.7信令网管系统和No.7信令监测系统的区别,并对当前网络存在的不足和其面临的困扰进行了简要说明。     

No.7信令网关设备信息安全问题

文章首先介绍了No.7信令网关所处的位置功能和网络信息安全的基本原理,然后从No.7信令网关交换网络侧功能实体、IP网络侧功能实体以及公共部分三个方面论述了No.7信令网关为保证信息安全需要考虑的问题。随着技术的进步,信令网关设备的信息安全将进一步得到保障。     

铁通No.7信令集中监测系统方案探讨及其应用

No.7信令集中监测系统是架构在No.7信令网络基础之上，以分析网络节点的业务对话为基础，面向维护、管理等层面的支撑平台。随着电信运营企业网络的发展，用仪表进行测试维护已不能实现信令的完整测试和个方位监测，因此，No.7信令集中监测系统在企业网的运维管理中得到应用，通过对七号信令链路的实时、动态监测，及时掌握网络中信令链路的运行状态、效率及各局向的来去话接通率等情况，使维护工作做到集中、自动、实时、高效，并在可能出现危及网络运行的故障时，及早发现隐患，防患于未然，确保No.7信令刚络及系统的高质、高效运行。     

宜春市No.7信令网负荷的优化和分析

1 宜春市No.7信令网现状 根据信令网的三层结构,在本地信令网络中一般设有一对LSTP(低级信令转接点)和多个SP(信令点),在省会级城市设有一对HSTP(高级信令转接点).宜春市No.7信令网主要由一对LSTP和一些SP组成,这一对LSTP主要负责传递本地网中SP之间的No.7信令,网络结构如图1所示.     

CCITT No.7信令系统在S1240型交换机中的实现

CCITT No.7信令系统是国际电报电话咨询委员会研究用千程控数字通信网和ISDN的公共信道系统,是具有国际标准性的。它是当前世界各国发展数字通信网和综合业务数字网所采用的主要信号方式之一。在我国,七号信令系统已经并将继续大量进网使用。CCITT No.7信令系统在S 1240型机中的实现是较早的。ITT的有关子公司在这方面投入了大量的研制力量。早在1983年9月,BTMC研制的S 1240 No.7信令系统就和英国     

下一代网络中信令网关的组网与应用

信令网关是下一代网络中的关键设备之一,信令网关实现了No.7信令网与IP网的互通。本文分析了中国No.7信令网与IP网互通的方式,在此基础上提出了信令网关的组网方式,以及两种方式各自的特点。     

No.7信令系统的安全威胁及其防护

No.7信令系统（SS7）是公用电话网的关键支撑系统,SS7网络最初作为封闭网络来设计的,整个网络由运营商完全控制,各实体高度信任。文章分别针对该系统的信令协议、网络节点和来自外部网络的安全威胁进行了分析,并从协议安全、边界防护和内部安全加固三个方面提出了构建信令系统防护体系的方案。     

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.     

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.     

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.     

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.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

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.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.