SDH设备低阶交叉的配置、优化与工程实例

近年SDH技术日渐式微，但现网仍存在大量的SDH设备，优化、调整是SDH系统建设的主要方式。交叉连接是SDH设备的重要功能；随着3G、4G业务的发展，SDH设备低阶交叉问题层出不穷；且多发生在核心层关键节点，成为制约业务开展的瓶颈。本文结合作者亲历的工程实例，说明低价交叉的配置方法、优化方法，希望能为网络规划设计提供指导。     

同步光网络和同步数字系列大容量交叉的实现

文章介绍一种基于时分 空分 时分(T S T)结构的大容量SONET/SDH交叉单元的实现方法和应用.它涉及到高速串行I/O、交叉结构以及设计考虑.它可以支持严格无阻塞的单播业务,也可以支持重配置无阻塞的双播业务.实现双播功能是SONET/SDH的单向通道保护环(UPSR)/双向复用段保护环(BLSR)的最基本要求.     

利用SDH微波简易实现长链的成环保护

目前传输网很多长链和一些需要成环的系统,因为各种各样的原因(如物业投诉、多方阻挠、地形复杂等),无法实现成环保护。在这种情况下,可以在这些需要建立光缆和建立不了的站点之间,建立一跳SDH微波,通过SDH微波的光口与光端机的光口对接,利用SDH微波的交叉连接配置,把光端机STM-1光口的1～63个VC12或者STM-4光口的4个VC4的1-63个VC12,从一个站点通过微波透明传输到下游站点,环路逻辑系统和业务配置则按照全光网络环路配置一样,把SDH微波当作完全的再生中继段,从而可以非常简易地实现长链和未成环系统的成环保护。这样优化了网络结构,最大可能地保护了在用系统的业务.     

E1-STM1SDH终端复用器的设计与实现

SDH是二十世纪90年代初出现的新一代传输网体制,SDH终端复用器是该传输体系中不可缺少的网元设备,用以实现低阶信号到高阶信号的复接和分插功能。根据ITU关于SDH技术体制的建议,介绍了一种基于PMC专用系列芯片,实现E1信号到STM1信号转换功能的SDH终端复用器设计方案,并以16路E1为例,详细描述了这种终端复用器的电路设计及其硬件实现过程,同时指出了设计实现时应该注意的问题。     

OptiX 2500+传输设备低阶交叉容量分析

OptiX 2500 被广泛应用于各大运营商的传输网络,但是这种设备由于受内部硬件设计的限制,可以配置的低价业务数量非常有限.随着业务的不断增长,OptiX 2500 低阶交叉容量饱和以及TUPP入总线饱和的问题已经越来越明显,一旦出现溢出,将无法再增加新的低阶业务,给网络的扩容带来极大的影响.虽然因为硬件条件的限制,难以从根本上改变这种瓶颈,但可以通过对设备原理的深入研究,摸索出节约低阶交叉总线的可行性方法,定i计算出各种组网配置下低阶交叉总线的占用数量,从而做到在接近低阶容量饱和时提前控制,解决潜在的网络隐患.     

基于FPGA的数字交叉连接矩阵的设计

采用两级结构设计了一种4×4SDXC矩阵,用以实现四路不同STM-1输入信号的完全无阻塞交叉连接。整个设计采用FPGA设计方法,阐述了SDH数字交叉连接矩阵的交换实质,重点解析了空分交换单元和时分交换单元的结构框图。最后,采用Quartus Ⅱ软件进行功能仿真,验证了设计的正确性。     

SDH网络中业务配置的软件实现

文章介绍了SDH概念规范及在光电设备中的实现原理,着重展示了管理与网元间业务配置功能流程图及代码实现,并对更高速率的系统实现提出了建议。     

简述SDH帧开销的监控功能

文章介绍了SDH传输系统中传递系统状态信息所用的信号帧再生段、复用段、高阶通道和低阶通道开销含义及用途。SDH传输系统依据开销信息完成告警、性能、配置管理,实现运行维护管理（OAM）是SDH传输网络系统的特色之一。告警管理不仅提供故障告警功能,而且为故障定位、排除提供依据,便于及时发现系统异常、诊断及排除故障,提高SDH传输系统可用度。     

Optix设备维护的几点体会

一、重视SDH基本原理、基础知识　　“高楼大厦平地起”,不学好SDH原理,谈维护好设备是句空话。在SDH原理中,STM-N信号的帧结构、基本复用映射结,SDH监控层层细化的RSOH、MSOH、HP-POH、LP-POH各字节的功能,指针工作的机理等,都应熟记于心。并熟悉SDH设备各种逻辑功能块的功能,网络拓扑结构、网络保护机理及时钟工作方式等。在Optix设备中,我们要掌握五大信号流。一是业务信号流。有三大功能模块:SDH接口与交叉单元间信号流处理功能块、交叉单元信号流处理功能块和PDH接口与交叉单元间信号流处理功能块。业务主信道由…     

一种高速大容量SDH交叉连接芯片的设计与实现

介绍了一种高速大容量SDH交叉连接芯片及其各模块所完成功能的设计与实现,重点论述了如何利用T-S-T三级交换网络实现高速大容量的SDH数字交叉,讨论了设计中面临的问题和解决方法.该芯片通过高性能的FPGA器件进行仿真和综合,已经在SDH交叉设备上成功地完成测试和验证.     

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.     

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.     

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