宽带接入VDSL2设备特性分析及其测试应用

中国电信在规模布署FTTH的同时,面临着光纤无法入户、ODN网络建设进度慢、质量要求高、宽带提速遇到瓶颈等问题。而基于VDSL2的Vectoring技术能够提供基于双绞线300米内100M的高带宽的接入,因此VDSL2接入是现有铜缆持续实现宽带提速,满足电信长期带宽需求的重要手段,能够最快捷地提升用户接入带宽,大大节省总投资和业务发放时间。     

“互联网+”时代来袭,运营商接入网引入10G GPON势在必行

随着与“互联网+”战略相关业务的快速规模落地,接入宽带业务得到了蓬勃发展,高清视频、4K电视、3D游戏和真人互动等高带宽业务迅速发展;同时激烈的市场竞争和“宽带中国”政策的驱动,使得各大运营商纷纷加速接入宽带网络的建设部署. 当前主流的EPON、GPON等宽带网络技术逐渐难以满足持续快速增长的各种高带宽业务对运营商现网带宽的需求.因此,运营商需要在现网中引入新的接入宽带技术,用来提供更高的带宽和更好的服务,提升高带宽业务的用户体验.当前已成熟的10G GPON技术恰好可以满足这一需求,可以解决业务快速发展和带宽不足的矛盾.     

PON中无源光分路器的分析

1 前言 随着用户对各种互联网、语音、交互式视频等业务综合接入要求的提高,3G网络大规模商用以及无线宽带网络对固定宽带接入网市场的冲击,固定接入网的接入带宽的提速需求日趋迫切,成为当前固定接入网建设的重中之重.     

开启大容量传送网的新纪元——烽火通信40 Gbit/s DWDM解决方案

随着三重播放、视频点播和互联网高速接入等业务的日益增长,加之国内3G移动通信时代的到来,接入层面的宽带普遍提速,传输网的带宽消耗呈几何级趋势增长,网络正面临传输带宽严重不足的局面,因此40 Gbit/s DWDM系统的建设迫在眉睫.     

ADSL宽带接入网络优化浅析

为实现集团公司提出的“宽带升级提速”工程,山东联通淄博分公司对现有ADSL宽带接入网络,从用户分布、网络覆盖、设备配置等方面分析研究,最终采用ADSL用户改制、光进铜退等创新性的优化手段,有效地提高ADSL宽带网络的网速,扩大了宽带网络的覆盖范围,最终实现ADSL宽带接入网络升级提速.     

端到端家庭宽带网络建设策略

伴随国家政策环境的利好,互联网视频业务迎来宝贵的发展机遇期,大视频时代即将到来,而这也将带动通信行业新一轮的发展。为了能够更好的满足家庭客户带宽需求,加快家宽基础网络建设,提升网络承载能力,提高用户粘性,必须做好家宽网络的规划建设。本文通过对家庭宽带网络端到端的分析,明晰了用户终端、出口带宽、内容网络等关键环节的问题,并提出了相应的网络建设策略。     

面向高流量家宽业务的接入网演进策略研究

随着高清网络电视、3D视频等新兴业务的发展,用户对接入带宽的需求越来越高。针对高流量业务对接入网的需求变化,本文分析了现网存在的问题,测算了不同场景下接入网的承载能力,提出应对宽带提速的接入网络演进策略：OLT下行策略和OLT上联部署策略。本文所提策略能够有效指导运营商在面对用户流量高增长的形势下及时调整接入网络结构,为用户提供更好的网络体验。     

ODN网络建设新模式探索

国家“十二五”规划为三网融合与宽带提速建设带来了新的历史机遇。在此背景下,各大运营商把用户带宽作为竞争的利器,以在“端”、“管”、“云”架构下的新价值链中取得先机。为适应新的形势,运营商需加快推进FTTx光纤宽带网建设,做大做宽管道,保持管道的核心优势。而如何低成本地建设FTTx网络,尤其是占FTTH网络大量成本的ODN网络,成为运营商关注的焦点问题。     

有线宽带PON网络千兆提速演进策略及应用

目前，有线宽带网络已突破低频电缆束缚，全面迈向光纤到户的宽带PON网络时代，用户接入速率从之前的几兆到如今主流的百兆，用户需求从基本带宽消费逐渐向内容感知体验倾斜，以百兆为基础的PON网络已经掀起了下一个提速浪潮。本文就上述背景，以PON网络为对象分析网络升级至10G PON速率的演进策略和方法，并结合中国移动上海公司“全球双千兆”示范区的建设，介绍10G GPON网络升级方式及应用要点，总结归纳给出网络升级的要点和重点，指导规模升级工程的建设。     

宽带接入面临的挑战

带宽提速灵活选择 对于宽带网络建设,目前主要有FTTH、FTTB等模式。带宽提速,需结合不同用户的宽带业务需求,灵活选择可行的技术和建设模式。20M带宽、多业务,日前FTTH是主流方式。     

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.