电信IP网向SDN演进的探讨

SDN提出了面向下一代IP网络的全新架构,以适应网络技术和应用的创新发展,为传统网络演进和变革指明了方向。对当前电信IP网面临的问题进行了阐述,介绍了SDN架构及基本特征,对SDN满足电信级要求的网络性能、网络扩展性、网络生存性3个方面进行了探讨和分析,并结合电信运营商网络现实需求,探索SDN在电信网的应用与实践。     

构建面向下一代移动互联网的创新型IP网络

未来的网络将会走向IP化，围绕着如何面对下一代移动互联网的创新型IP网络架构这一议题，来自运营商和制造商的多位专家在主题为“构建安全可靠、有服务质量保证的IP网络”的网络分会场3，从不同的角度就异构网络的安全、电信级IP网络服务质量、增值业务等问题进行了探讨。     

MA5200G助力运营商打造精品城域网

1 引言 随着IP宽带路由技术的不断发展和业界多年对IP宽带网上实际应用的探讨,运营商的城域网已逐步成为未来电信多业务的承载网,并确定了以大容量、高带宽、高处理能力的路由器为承载核心,构建物理和逻辑层次清晰的三层路由网络(IP城域网)和二层宽带接入网的网络架构.在这个网络优化和多业务转型的过程中,IP核心网络"边缘智能化"将成为实现运营商网络和业务转型的关键.     

国内行业动态

思科公司为电信运营商移植“IP下一代网络”思科公司近日在SuperComm大会上宣布,帮助电信运营商移植到高级全互联网协议(IP)网络的计划保持了非常强劲的发展势头。此计划名为“IP下一代网络(IP NGN)”, 可提高电信运营商的各项能力,如交付创新业务、提高运营和前期投资效率、以及提前推出增值网络和业务控制功能, 以满足运营商长期业务目标等。思科于2004年12月首次公布其IP NGN构想与架构,目前的这一宣布代表了思科这一战略的进一步发展。思科IP NGN解决方案可帮助电信运营商移植到IP NGN,如思科帮助     

中国移动IP城域网网络架构选择探讨

本文在各大电信运营商不断提出转型的背景下,从城域网所面临的任务出发,对影响 IP 城域网建设架构选择的主要因素进行了分析,并结合中国移动实际情况提出了目标网络发展架构、中期网络发展架构和近期网络发展架构以及网络的演进策略,以期对中国移动建设IP城域网提供参考。     

7342 ISAM FTTU——引领FTTx宽带光接入发展潮流

1 FTTx宽带光接入网络的发展是大势所趋 随着互联网和宽带应用的进一步发展,以"铜缆"为基础的电信网络必须逐渐向宽带多媒体架构转变.近几年来,运营商虽然已经在核心网和IP承载网进行了大量投资,但是以DSL技术为主的接入层仍然存在带宽瓶颈,大力发展FTTx宽带光接入网络已经成为全球运营商的共识.     

从网络的规划建设和运维管理论网络架构

从业务及技术出发分析总结了电信运营商网络的架构及其演进历程。业务主体由话音向数据的变化导致电信网的主体架构也由电路交换网向分组交换网演进,IP网正在逐渐成为所有业务的统一承载网络。互联网本质是"扁平"的,但为克服互联网流量的不确定性以及技术架构的缺陷,IP网在实际建设中采用了一定的分层结构,IP网的分层结构同时也决定了波分网络的分层结构。通过网管系统的集中以及管理架构的简化,实现"一二干融合",是国内电信运营商集约化运营的切入点。     

全IP时代中国移动传送网要解决的几个问题

目前,电信业正在向IP化、移动化、宽带化和融合化四个趋势变化。IP化主要体现在网络上,过去的网络是纵向的网络,横向之间没有什么联系。随着整个网络的IP化,网络的架构发生了很大的变化,成了一个分层的网络架构。 IP化是通信网络发展的大势所趋,用户对网络IP化有很大的需求。首先,用户需要更高的带宽,未来5年内不管固定用户还是移动用户,对带宽的需求将是现在的10倍甚至更多。其次,用户需要在不同终端上得到更好的服务体验,包括手机和手提电脑。第三,用户越来越希望参与通信服务的定制。目前用户已经不满足于运营商推给他的服务,希望参与定制服务,这就需要运营商提供固定、移动融合的服务,IP技术的应用将进一步推动固定与移动通信的融合（FMC）。 IP化给网络带来了丰富多彩的业务,也能够令运营商降低经营成本,提升服务质量,但同时也给运营商带来了诸多问题和挑战：在进行网络IP化的同时,运营商该如何满足未来分组业务需求的网络架构的选择？如何提高网络的效率、扩展性和可管理性？如何协调传统业务和新业务的发展？在网络演进的同时如何降低网络建设和运营成本？这值得运营商探讨和研究。为了探究运营商光传送网的发展趋势与策略以及电信设备商将为运营商提供怎样的解决方案,本刊特推出“网络IP化”专题。     

多业务融合承载网与传输网的关键技术分析

IP化是未来电信网络发展的必然趋势。业内越来越关注IP承载技术和传输技术的分工和融合，作为网络层面融合的主旋律，IP网络必将成为未来语音、视频、数据以及各种综合多媒体业务统一承载的网络平台，这在电信界已经达成共识。但是，作为多业务融合承载网络，传统的IP网络很难满足电信级业务对QoS、安全、可靠性和管控的要求。因此，需要对传统IP网络进行改进和优化，即保留IP灵活方便的特性，又满足电信业务承载和运营商对网络的新要求。[编者按]     

网络转型驱动下的省级电信运营商管理运营变革策略

万物互联时代,传统运维模式和封闭的网络能力限制了电信运营商的响应能力和竞争力,基于SDN/NFV的下一代网络成为未来网络演进的必然选择。本文将以省级电信运营商为例,重点论述电信运营商在网络转型中的战略演进路径,提出了下一代网络的建设规划模式,研究了网络转型给电信运营商带来的业务形态及交付模式变化,针对省级运营商的运营架构及组织机构变革提出了具体建议。     

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.     

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.     

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.     

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.     

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.