基于网络处理器IXP1200的以太网上联卡的设计

以太网上联卡是以ATM技术为内核的DSLAM设备中的一块板卡，DSLAM设备通过他直接与IP网络相连，由于在进行ATM与IP转换时要消耗大量资源，容易使上联卡成为系统瓶颈。本文提出了一种基于网络处理器IXP1200的以太网上联卡设计方案，利用网络处理器强大的数据处理能力和高度灵活性，实现对数据的线速处理，并可根据需要增加新的功能和特性。     

网络处理器IXP1200在DSLAM设备中的应用

文章提出了一种在DSLAM设备中,基于网络处理器IXP1200的上联卡(uplinkcard)设计应用方案,利用网络处理器强大的数据处理能力和高度灵活性,实现对数据的高速处理。着重介绍了该方案的硬件和软件的设计和实现过程。     

网络处理器IXP1200在DSLAM设备中的应用

文章提出了一种在DSLAM设备中,基于网络处理器IXP1200的上联卡(uplink card)设计应用方案,利用网络处理器强大的数据处理能力和高度灵活性,实现对数据的高速处理.着重介绍了该方案的硬件和软件的设计和实现过程.     

IP-DSLAM的应用组网策略

随着ADSL宽带接入技术的普及和发展,同时为了适应IP城域骨干网宽带接入的需要,ADSL局端设备DSLAM开始提供以太网上行接口,这类设备统称为“IPDSALM”。由于ADSL线路普遍采用了ATM传送模式,业已成熟并广泛应用的传统DSALM设备普遍采用了ATM交换机制并提供ATM上行接口。而IP DSLAM设备根据所采用的交换机制则可分为两类:一类为采用ATM交换机制,同时提供以太网上行接口,其主流的实现方式为仅提供ATM至以太网的链路层转换,但也有些设备在其上行以太网接口板卡上甚至实现了网络层的认证和路由的功能;而另一类则考虑到当前绝大多数实用的VDSL线路采用了以太网传送模式,而且面向公众宽带数据接入市场,存在着将ADSL与VDSL集成的需要,DSLAM设备采用了以太网交换机制,从而使ADSL线路中ATM信元至以太网帧的转换在线路板卡上实现;由于这类设备采用了以太网交换机制,因此也较容易实现网络层的认证和路由的功能。综上所述的种种实现方式,IPDSLAM设备又可根据其协议层次功能的实现分为二层(即链路层)IP DSLAM和三层(即网络层)IP DSLAM。     

ATM上行口与以太网上行口的ADSL技术比较

ADSL局端设备为DSLAM，目前一般采用ATM STM-1接口或100M/1000M以太网接口连接到ATM或IP城域网上。对采用ATM上行口和采用以太网上行口的DSLAM进行比较和分析，希望能对选择和使用ADSL设备有所帮助。     

ATM上行口与以太网上行口的ADSL技术比较

ADSL局端设备为DSLAM,目前一般采用ATM STM-1接口或100M/1000M以太网接口连接到ATM或IP城域网上。对采用ATM上行口和采用以太网上行口的DSLAM进行比较和分析,希望能对选择和使用ADSL设备有所帮助。     

—种基于网络处理器的城域以太交换系统的设计

本文介绍了基于IXP1200网络处理器进行城域以太交换系统数据通道的设计，在以太交换的基础上，实现了独特的EVC连接功能。文中描述了具体的系统结构，任务结构，相应的数据结构以及该城域交换系统数据层面的逻辑流程框图；同时说明了基于网络处理器的设计方法和步骤。本文基于网络处理器实现的城域以太交换系统可提供点到点和多点到多点的EVC连接。     

ADSL DSLAM的技术演进

第一代：纯ATM结构第一代ADSL DSLAM从下行的线路到上行的接口全部采用ATM方式，这是最符合ADSL技术自身特点的结构。这一代的DSLAM只能使用ATM网络作为其接入与核心网络，而ATM网络接口直到目前为止仍然仅能提供622M接口，交换容量也通常只有几个GB，这样就导致在提供大容量的核心网络时要使用大量的ATM设备，再加上ATM设备本身成本较高，也就导致了ATM核心网络的建网成本高昂。第一代ADSL DSLAM建设成本高昂不仅仅来自ATM网络本身，还来自于网关设备。无论ATM网络建设的有多么丰富，最终还要与以IP技术为核心的In…     

DSLAM设备中IP接入模块的实现

针对目前普遍采用的DSLAM设备。提出了一种IP接入模块的设计方案和IP over ATM解决方案，实现了基于ATM架构的IP—DSLAM技术，既发挥了ATM的综合业务接入能力，又使得运营商能够利用现有的ATM设备开展IP业务。     

PMCS的IP DSLAM促三网合一 www.pmc-sierra.com/networking

2月底,PMC-Sierra公司宣布推出 PM7354型号S／UNI DUPLEX GE多路 复用器,此低成本装置可为IP DSL接入 复用器(DSLAM)提供ATM转换至以太 网模式的功能。PMCS称以S/UNI DUPLEX GE设计的IP DSLAM设备可 减低整体开发及生产成本,并让客户减 少实际装配成本及提供具增值效益的三 网合一服务。     

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.     

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.     

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     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first     

JOURNAL OF ELECTRONICS(CHINA)

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NOTICE OF CHANGING JOURNAL OF ELECTRONICS （CHINA） TO MICROSYSTEMS ＆ NANOENGINEERING

正Journal of Electronics(China)(JE)was founded in 1984,sponsored by the Institute of Electronics,Chinese Academy of Sciences.JE is one of the first English academic journals in China in the field of Electronics and Information technology.The journal was published quarterly since it was launched in 1984 to 2003,then it is published bimonthly till now.During