IP网络中的QoS研究

本文简要介绍了IETF建议的综合服务(Int-serv)／RSVP、差分服务(Diff-Serv)、多协议标记交换MPLS、业务流量工程TE等几种IP网络QoS保证方案的工作原理，并介绍了流量管理的过程和MPLS流量管理的概念。     

二层包传送网技术的多点连接性探讨

多点连接性网络 在IP／MPLS网络中,MPLS技术被用来改善IP的性能,同时也是一种在路南器之间的网络引入面向连接的流量工程。这种面向连接网络的实质是在标签交换通路上实施MPLS标签交换机制,实现点到点（P2P）的连接。在此情形中,IP节点通过使用MPLS标签所构成的P2P连接,提供了IP节点间（或IP层）的多点连接性,即多点到多点（MP2MP）连接。     

MPLS技术的发展及应用

1概述 MPLS（Multi-Protocol Label Switching，多协议标签交换）是一种在通信网内利用定长的标签来引导数据高速传输和交换的网络技术。它是基于标签的IP路由选择方法，采用简化了的技术来完成第三层和第二层的转换。它可以为每个IP数据包提供一个标签，将标签与IP数据包封装于新的MPLS数据包中，并决定IP数据包的传输路径以及优先顺序。通过MPLS，可以实现增强的流量工程，还可以使用MPLS流量工程功能实现负载均衡，这些相对简明的流量工程应用为利用MPLS使服务供应商和企业改善整体网络管理、更好地利用可用带宽提供了最具吸引力的机会。     

感知区分服务的MPLS流量工程技术研究

区分服务（Diffsevr）通过服务分级定义了流量的逐跳行为（PHB）；流量工程（Traffic Engnineering）实现转发路径的优化。感知区分服务的MPLS流量工程（Diffsevr-aware MPLS Traffic Engnineering，简称DS-TE）将MPLS的区分服务与流量工程结合在一起，使其能够感知彼此的存在。DS-TE提出了基于类的资源分配思想，可以根据业务的类型，细粒度地建立交换路径，进一步保证了QoS。     

未来光网络中的MPλS技术

MPLS技术的发展和全光网络核心技术的突飞猛进产生了一种更紧凑的IP／DWDM集成方案MPλS。它综合了MPLS控制能力了光 交换机的大容量 交换传输优势，允许业务层通过现有的控制平面动态地向传输层申请带宽。文中首先介绍了MPλS网络结构，随后详细分析了MPλS路由和波长分配方案，讨论了MPλS局限性和相关协议及扩展的GMPLS技术。     

IP网络QoS实现技术研究

文章主要研究基于多协议标记交换(MPLS)技术和区分服务(DiffServ)／资源预留协议(RSVP)结合模型的IP网络服务质量(QoS)实现技术。首先根据带宽代理(BB)模型给出一种简化的QoS体系结构，然后着重讨论该结构中的4个主要模块：RSVP模块、DiffServ模块、MPLS模块和BB控制模块。在ns-2．26上的仿真表明，该方案有效地改善了丢包率和时延这二个QoS性能指标。     

多约束路由的MPLS流量工程

MPLS流量工程问题是在网络边缘节点间建立满足流量需求的路径,使网络性能最优化,通过多路径分流传输流量可使资源利用最优化.基于多径路由是用于实现MPLS网络中的流量工程的一个有效的方案.但多径路由中的具体表述和实践算法,即路径的计算和流量分割率中应该考虑到的路径约束条件或方针政策,还没有太多的涉及.文章给出了一个可以满足网络资源以及政策需要的较全面的多约束路由方案.     

内嵌MPLS的多业务传送平台(MSTP)

内嵌MPLS的MST不但保证了多种网络的互连互通,而且能够对接入业务有效地实施端到端的流量工程,提供有效的QoS保证。介绍了内嵌MPLS多业务传输平台的体系结构、功能模型,并详细阐述了内嵌MPLS的PW(PseudoWire)接入方法,及对以太网业务在内嵌MPLS的MSTP网中的传输和映射处理。     

精品出版快讯

MPLS宽带网络互联技术人民邮电出版社书号：08927 定价：51元 本书专门介绍目前在宽带通信技术领域里非常引人注目的热点技术--多协议标签交换MPLS。主要内容包括：概论、通信网络传输交换技术的演变、MPLS网络体系结构、标签、标签分发协议、MPLS网中应用的路由技术、标签交换路径、MPLS网络的QoS控制、MPLS流量工程、MPLS技术在帧中继网络中的应用、基于ATM的MPLS网络互联、MPLS技术应用于虚拟专用网、基于MPLS的话音业务、MPLS网络管理与维护等。 本书内容新颖,概念清楚,理论结合实际,可帮助读者尽快了解MPL…     

IP网络与数字付费电视未来发展试想

基于MPLS/VPN的internet组播技术对数字付费电视发展:MPLS/VPN是基于MPLS技术的IP VPN,在网络交换机和路由设备用应MPLS技术,简化路由的路径选择方式, 利用结合传统路由技术的标签交换实现因特网上IP虚拟专用网络组播技术,是MPLS/VPN对于实现电视视频数据包在IP 网络上传输的QOS保证。     

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.     

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.     

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