新环境下SDH传输网络的特点与基本构成分析

随着网络技术的迅速发展,通信网络规模不断扩展,SDH传输网络逐渐发展起来并不断在实践中走向成熟。SDH传输网络具有很强的网管能力和统一比特率,其应用对于提高网管效率、提高网络资源利用率、降低网络维护成本具有重要作用,能够保证网络操作的便捷性、高效性和灵活性。     

南京本地SDH中继传输网

本文对南京本地网中SDH网的网络结构、保护方式、Mini—DXC的应用,SDH网的同步及网管进行了较全面的阐述.     

SDH网络技术研讨会在京召开

今年10月,邮电部电信科学技术研究院和富士通集团联合在京举办了SDH网络技研讨会。会上介绍了SDH网络管理系统,特别是由CATT和富士通联合开发的网络管理系统FLEXR Plus W/Q3代理。富士通集团则展示了其在同步传送网络、光纤接入网和智能化网络管理系统的成就;会上还对高层网管—低层网管(SNMA-FLEXR PLUS)、2.5G SDH     

利用广域网实现对SDH设备的远程网管

通过DDN专线实现SDH设备远程网管系统的设计和建设全过程，并列举了所需各种硬件配置和软件设定。本系统充分发挥了SDH的强大网管功能，实现了对传输设备的远程网管和远程监控，完善了网管系统，提高了网络安全性和通信质量。     

2014年四川铁通集中化维护传输网管建设方案

随着数据业务的发展,地市传输网络由传统SDH向PTN过渡,早期SDH网络网管采用iManager T2000或NES,版本陈旧,与现有PTN网管iManager U2000相互独立,不支持新业务开通,网络运维工作量增大。本文结合地市传输网络实际,提出网管集中化方案,降低了网络运维工作量,实现了本地网传输网络集中管理,优化了网络维护结构。     

SDH网管的使用

SDH网管是传输中最重要的工具,一方面,因SDH网管功能的强大,使其具备强大的管理、控制功能,但是另一方面,也有不利因素,表现在SDH设备对网管的依赖性太强,一旦网管做误操作,或更严重的网管瘫痪,势必造成极为严重的后果,轻者某些站业务中断,重者导致整个网络瘫痪,所以必须加强对网管重要性的认识,并且要求维护人员日常维护工作中熟练使用网管,判断故障,解决问题。本文结合工作中的传输维护事例,对网管做一简单剖析。1SDH网管的使用SDH网管主要有5个功能模块,即配置管理模块、故障管理模块、性能管理模块、维护管理模块、安全管理模块。…     

烽火设备网元变灰的故障处理

众所周知,SDH技术之所以得到广泛的应用,除了它具有灵活的分插复用能力和强大的自愈保护功能外,还缘于其强大的网管能力。SDH丰富的开销比特保证了可以通过网管实时监控设备的告警和性能,完成网络配置、保护倒换、公务联络等远程控制功能。数据通讯网(DCN)是网管系统和网元之间数据交互的通道,本文通过武汉电信SDH传输网烽火网管系统DCN的实际应用和典型故障处理的分析,说明了为保证网管控制信息正常到达网元,必须按照各网管系统自身管理结构层次组织特点组建数据通讯网(DCN)。     

基于SDH网络的时间同步技术研究

简要介绍了SDH网络时间同步技术的国内外发展现状,研究了SDH时间同步信息的传输时延特性,对双向时间同步算法的误差因素进行了分析,提出了SDH时间网管系统的建设要求,明确了时间同步精度的测量方法,并对SDH网络时间同步技术的应用前景进行了展望.     

SDH性能管理系统的研究与实现

介绍了同步数字系列(SDH)性能及其对SDH网络质量的影响,在此基础上,针对网管系统对性能数据管理能力较差的问题,提出通过研发SDH性能管理系统,实现对性能数据的监控、统计和分析。实践表明该系统能够有效发现网络隐患,提高网络安全性和传输质量。     

SDH传输网集中监控与网管的优化

结合原哈尔滨网通sDH传输网监控情况,针对sDH城域网在多点网管同时监控时,不同网管系统之间出现的数据同步、告警同步,以及考虑节约二次投资费用等,提出了我们的解决方案.还介绍网管分布情况,针对华为SDH网管的功能提出网管系统优化方案.部分用户接入层SDH网络尚未接入网管监控系统,也是需要处理的问题.通过这些措施,提高了原哈尔滨网通传输网的维护管理效率.     

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