802.11 mesh网的安全研究

WMN（wireless Mesh Network）是一种动态的自组织、自配置的网络。网络中的各节点自动建立成一个Adhoc网络并保持一种网状连接。WMN具有前期投入低、系统容量大、维护简单、可靠性高等许多优点。802．11mesh网是一种802．11和mesh相结合的组网结构，它使用一组网状的无线路由器相连来提供一定区域的无线覆盖。由于802．11mesh网的一些特点，这种网络也带来了一些不同于传统802．11网络的一些新的安全挑战。     

浅谈无线MESH网络技术

无线mesh网络是新近出现的一种无线多跳网状拓扑网络,是一种非常有前途的无线接入网络技术。本文简要介绍了无线mesh网的网络结构、特点、应用,并分析了影响无线mesh网性能的主要技术因素。     

莫块化无线mesh网络加密方案设计

文章在基于装有Open Wrt和Click的无线路由器所搭建的无线mesh网络测试床上,研究使用Click模块化路由编程工具,结合802．11i和802．11s草案针对无线mesh网络安全的协议设计方案,提出在无认证服务器环境中,使用预共享密钥进行数据包链路层加密以确保mesh节点间通信保密可靠的安全解决方案。     

基于无线传感器网络的远程智能抄表系统设计

无线传感器网络 无线传感器网络技术是一种近距离、低复杂度、低功耗、低数据速率、低成本的双向无线通信技术,是一组基于IEEE802．15．4无线标准研制开发的有关组网、安全和应用软件方面的技术。它支持3种主要的白组织无线网络类型,即星状网、集群树状网和网状网三种拓扑。     

无线网状网通信安全技术论述

随着近些年来我国通信技术的不断发展,人们对于通信安全也越来越重视,而无线网状网作为一种动态的自配置网络,它既具有无线网络的特征,同时也具备多跳、自组织和配置灵活等特征,虽然无线网络状网有着这些优势,但是在实际的应用过程中,由于其缺乏明确的网络边界防线,所以说无线网状网的安全一直以来都是人们较为关注的一个话题.因此本文就如何有效地保障无线网状网的通信安全进行了一定的论述,并介绍了相应的无线网状网通信安全技术.     

应急通信保障中无线自组网技术的应用研究

无线自组网具有无中心、自配置和快速组网等显著特点,非常适合用于应急通信保障。首先,介绍了当前国内应急通信的现状和存在的问题。然后,概述了以Ad Hoc网络、无线传感网和无线mesh网络为代表的无线自组网的显著特点和技术优势,并举例说明了无线自组网在应急通信保障中的几种具体应用。最后,展望了应急通信网络今后的发展方向。     

无线网状网及其在铁路应急通信中的应用

无线网状网融合了无线局域网和Ad Hoc络的优势,是一种大容量、高速率、覆盖范围广的网络。文章首先介绍了无线网状网的起源发展,其次研究了无线网状网的网络结构及特点,最后介绍了铁路应急通信的网络部署及无线网状网在铁路应急通信中的应用,并对目前无线网状网的研究热点和发展前景做了展望。     

VCON发布HD5000和vPoint HD的新版本

近日，美国网件公司(NETGEAR)发布了基于Airgo公司TrueMIMOTM技术的新款MIMOG无线产品：MIMOG无线路由器(WGM124)和网卡(WGM511)。NETGEAR MIM0G无线路由器提供高达108Mbps的速度，极大地改善802．11b和802、11g网络性能，与802．11b、802．11g无线网络完全兼容，适应流媒体等高级的网络应用，为用户提供高性能的无线网络技术，     

基于802.11的多跳移动自组织网测试床设计与实现

随着对自组织网技术研究的不断深入，设计一个Adhoc网络测试床越来越具有重要的意义．文中介绍了自组织网的概念，提出了一种基于802．11技术的自组织网测试床设计方案，并采用该方案设计的测试床对Q—AODV的数据业务模块进行了初步的实验．     

802.11无线局域网与公用网的连接方式探讨

作为一种有广阔前景的技术，IEEE802．11(简称802．11)无线局域网正在得到越来越多人的关注，而运营商也考虑在热点地区布署无线局域网以作为其接入手段的一种补充。由于早期制定协议时对如何接入公用网考虑得不够完全，因而802．11标准在AAA（authenticate、authority、account)、漫游、加密等方面还存在一些不完备之处。同时，在局域网布署以后将对运营商原有的网络产生影响，运营商也希望能将其纳入至统一的网络管理、规划和业务控制系统中。本描述了目前国际上正在进行的这方面努力，同时提出了原有经营无线业务的运营商在铺设基于802．11的无线局域网时采用的解决方案。最后简要介绍了802．11无线局域网在未来的发展方向。     

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