运营商云资源池部署应用Overlay SDN解决方案

移动互联网背景下,云计算技术实现了IT资源的虚拟化管理,用户可以按需灵活地申请资源。底层承载网络如何应对这种新变化,为用户按需灵活地创建网络连接并满足特定需求的承载服务已经成为运营商云资源池解决方案关注的焦点。文章主要介绍在云资源池的网络建设中引入SDN(软件定义网络技术)的解决方案以简化网络配置、实现灵活组网、满足个性化服务质量,并考虑到SDN南向接口技术不是很成熟,引入软件定义的Overlay层,来屏蔽底层物理设备的差异性,实现云计算网络的智能化,更好的支撑运营商云计算业务的发展。     

基于SDN的网络虚拟化平台及其隔离性研究

随着云计算的高速发展,虚拟化正成为近年来在企业级环境下广泛应用的技术。除服务器及存储虚拟化外,在SDN和OpenFlow技术的推动下,网络虚拟化成为热点,基于SDN的网络虚拟化平台也应运而生。在分析基于SDN的网络虚拟化设计目标的基础上,对近年来业界推出的4种典型SDN网络虚拟化平台的系统架构和原理进行了对比,并对其安全和隔离性进行了分析总结。     

基于SDN的网络虚拟化仿真研究

软件定义网络的集中控制和可编程能力解决了传统网络虚拟化技术的弊端。为了进一步研究网络虚拟化技术,采用Mininet、OpenVirteX和Floodlight等软件,提出一种基于SDN的网络虚拟化仿真平台实现方案。总结了SDN网络和网络虚拟化特性,介绍了基于SDN的网络虚拟化仿真平台的系统架构,验证了其功能和隔离特性。提出的仿真平台为基于SDN技术的网络虚拟化创新提供了良好的平台支撑。     

基于SDN的数据中心网络技术研究

随着云计算数据中心规模的扩大,虚拟化技术的成熟应用保证了计算能力、存储能力的自动伸缩,然而仍然采用传统网络技术,虚拟化程度严重不足,网络能力逐渐成为制约云计算灵活提供资源的瓶颈。SDN(Software Defined Network,软件定义网络)实现了控制与转发的分离,有效解决了网络资源的灵活配置问题。文章对现有SDN技术进行研究,重点分析基于SDN的数据中心网络技术,详细阐述SDN架构,并对控制器和转发设备进行分析说明,对理解基于SDN的数据中心网络具有借鉴意义,对SDN在数据中心落地提供了技术依据。其引入有效解决了数据中心的海量数据多路径转发、虚拟机智能迁移等网络问题,实现了对网络流量的智能规划。     

overlay SDN实现异构兼容的关键技术

云计算的规模化发展对数据中心网络提出了新的挑战,要求应用SDN技术对数据中心网络进行虚拟化,以满足多租户环境下灵活调整的动态网络需求,overlay SDN是实现数据中心网络虚拟化的核心技术。研究了overlay SDN网络虚拟化的关键技术,提出了商业overlay SDN存在的兼容性问题,分析了overlay SDN 实现异构兼容的主要方法,并提出了基于开源和白盒交换机实现异构兼容的overlay SDN架构。     

SDN与NFV在云计算IDC中的应用

主要探讨如何在云计算IDC(互联网数据中心)的网络建设中引入SDN(软件定义网络)技术,以简化网络配置,实现多租户环境下的灵活组网,满足个性化QoS(服务质量)、安全性等要求,更好地支撑云计算IDC的业务发展。考虑到OpenFlow(SDN的一种南向标准接口)标准的产业成熟度还有所欠缺,借鉴NFV(网络功能虚拟化)的理念,引入软件定义的Overlay(叠加网络)层,来屏蔽底层物理设备的差异性,从而在无需对现有硬件设备进行升级改造的前提下,实现云计算IDC网络的智能化可管可控。     

一种面向SDN网络的云安全技术方案研究和实现

本文从当前云计算快速发展、安全问题影响日益严重的现状出发,对SDN和云安全进行了介绍,分析了部署SDN和虚拟化的新型网络所带来的问题和挑战,提出了安全设备虚拟化,资源池化,通过安全运营管理平台与SDN控制器的协同,对流量按需调度,通过适配OpenStack进行资源实例的自动化管理,并针对方案进行了有效的验证和评估.通过基于SDN网络的云安全研究,对中国移动集团公众服务云未来安全服务的发展具有相当的参考价值.     

基于SDN的VxLAN组网方案研究

传统IDC面临的资源弹性不足问题日益凸显,而VDC网络虚拟化技术框架作为一种解决策略,结合Overlay网络中VxLAN协议可攻克上述难题.然而VxLAN协议的全局表项同步需要复杂组播划分,基于SDN构建VxLAN的方式,可使全局表项同步流程得到简化,从而对VxLAN网络的控制更加灵活,最后给出对VxLAN全局表项同步的实验室验证数据.     

NFV助力中国移动 加速迈向新型数字服务时代

中国移动研究院院长黄晓庆表示:"未来运营商既是网络服务公司又是云计算服务公司,不仅要传送数据还要计算数据,并将进一步转变成集电信服务和运算服务于一体的新型数字服务企业。"云计算、LTE、智能终端等的快速发展,网络数据流量呈爆炸性增长,在给运营商带来利润的同时,也给网络设备带来了巨大压力。为解决当前网络难题,新的网络技术层出不穷,其中最受关注的莫过于SDN和NFV。SDN主要采用集中控制器以控制分布式网络,解决传输、路由等领域的软件化问题;与SDN相互补充、相辅相成的NFV则聚焦于网络核心层面,采用虚拟化技术,使网络设备功能不再依赖专用硬     

面向SDN网络虚拟化平台的控制器放置算法

随着网络技术发展,以网络虚拟化为手段解决TCP/IP网络体系结构僵化问题已成为未来网络领域发展的主流方向之一.SDN(software defined networking,软件定义网络)作为一种新兴的网络体系结构,为网络虚拟化提供了有效的解决方案.首先总结了当前具有代表性的SDN网络虚拟化平台,并对比了SDN与传统网络环境中部署虚拟网的区别,然后针对SDN网络虚拟化平台中的虚拟网络映射问题,提出一种时延敏感的虚拟化控制器放置算法,最后通过实验验证了该算法在提高网络资源的利用效率的同时,保证了控制器与底层交换机的通信时延在可接受范围之内.     

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