三网融合与广电网络双向化建设

本文简要介绍三网融合各行业的行动情况,重点介绍了广电有线网络双向化建设方案双向HFC、EPON＋LAN、单向HFC＋EPON＋EOC和三通道接入技术,指出单向HFC＋EPON＋EOC是广电NGB建设的较优方案之一。     

三网融合接入网PON＋EOC技术

充分利用广电网络HFC资源,通过EPON和EOC技术实现广电网络的双向改造,可以提供数据、视频、语音等多业务的三网融合。通过对EPON＋EOC技术方案进行分析,得出EPON＋EOC技术是面向广电运营商NGB网络接入层首选技术的结论。     

双向HFC Vs. EPON＋EoC——NGB有线接入方式探讨

随着三网融合试点方案全面启动,如何进行双向网络改造,以应对电信的竞争,成为广电运营商面临的共性问题。目前广电双向网改造最常用的两种技术为HFC网络接入技术（CMTS）及基于以太网协议的用户接入技术（EPON＋EOC、EPON＋LAN）。近年来,随着多种EOC解决方案不断推出,EPON＋EOC方案开始为越来越多的运营商所采用,一些业内人士甚至预言,EPON＋EOC将在不远的将来成为双向网改的主流。但业内亦有不同的观点和实践,保定根据自身的改造实践及广电业务角度,提出HFC网络接入技术更适应未来NGB环境的论点。欢迎您就此问题展开讨论,来稿请发wang_yun@ccw.com.cn或wang_yun118@qq.com。     

双向HFC网络采用EPON技术的探讨

本文简单介绍了EPON的技术特点,结合EPON技术的HFC双向光网络的关键技术、双向HFC采用EPON的改造方案：EPON＋LAN改造方案和EPON＋无源EOC方案广电运营商在网络建设和综合业务规划时．研究如何利用双向HFC网络光缆的共缆多纤条件,增加专门的数据业务通道而采用EPON的方案是有意义的讨论“光进铜退”环境条件下的双向HFC网络举例说明了EPON在接入网领域的广泛应用潜能．     

EPON+EOC技术在广电双向网络中的应用

本文介绍应用EPON和EOC成熟技术,结合目前有线电视HFC网络的现状,提出了采用EPON+EOC技术在有线电视HFC网络中应用的可行性、优越性,根据广电的资金状态对有线网络进行分步实施双向改造,来实现广电有线网络一样能实现全双向化、数字化,能成为综合信息业务发展的主要网络提供者,成为“三网融合”中一支不可忽视的主力军。用EPON+EOC+1550nm技术方案对当地有线网络进行了改造,效果非常好,一线全业务进家得到了用户的认可,网络用户数量发展很快。     

广电网络双向改造

天津广电充分利用现有的HFC网络网络,采用EPON+EOC进行网络改造。数据信号通过EPON采用1490/1310nm传输,有利于广电与其他运营商在最后100m上的竞争。     

浅谈基于EPON＋EOC的HFC网双向建设

本文简要介绍了通过EPON＋EOC技术实现HFC网双向化的基本原理,分析了EPON系统和EOC系统设计要点,并指出了EPON＋EOC技术未来的发展趋势。本文是对当前较为流行的HFC双向化技术的普遍性分析,并不拘泥于具体产品,对各个厂家并无偏袒之言。     

面向NGB的EPON和EOC综合网管方案

有线电视网是国家重要的信息化基础设施,随着业务发展和三网融合的迫切需求,对网络质量和承载能力提出了更高的要求。传统有线电视HFC网络为单向网络,不能满足这些需求,所以有线电视网络必须进行数字化和双向化改造。结合广电的网络特点,目前EPON＋EOC成为双向网改造的主要技术方案之一。UT斯达康公司焦名胜所撰《面向NGB的EPON和EOC综合网管方案》一文,分析了现阶段EPON＋EOC方案存在的管理问题,为满足下一代广播电视网NGB发展的需求,提出了EPON＋EOC综合网管方案。     

EPON＋EOC技术在衢州市有线电视双向网络改造中的实践

广电系统正逐步采用EPON、EOC作为网络接入技术,分析目前广电宽带主流接入技术以及采用这些技术所遇到的问题,此外也对EOC技术加以比较,分析各种技术所适用的网络环境,最后介绍EPON＋EOC技术方案在衢州网络的应用情况。     

EPON+EOC技术在招远广电有线电视网络双向改造中的应用

招远广播电视台采用EPON+EOC方式,对原有HFC网络成功地进行了双向改造。在介绍EPON和EOC的技术原理的基础上,对双向网络系统架构、技术模式和接入方式等进行了详细阐述。     

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.     

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.     

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.     

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