基于即时通信的移动邮件终端的设计与实现

使用J2ME无线应用技术,采用可扩展消息与在线协议XMPP和Pull-Mail移动邮件解决方案,设计和实现了一个基于即时通信的移动邮件终端.该终端将一般的即时通信业务与移动邮件业务进行整合,为用户的信息获取和交流提供了一个便捷、可靠的方式.     

基于LTE的宽带多媒体集群技术在公安警务中的应用与发展

相对于传统窄带集群通信技术,基于LTE的宽带多媒体集群系统可以提供更大的无线传输带宽,能够实现无线高清视频监控、视频对讲、视频调度等宽带多媒体业务,可广泛应用于公安业务。文章介绍了基于LTE的宽带多媒体集群系统的架构及其在公安业务领域的典型应用,并且结合公安行业的实际情况,将窄带集群通信与宽带多媒体通信进行有效融合,可实现警用集群通信从窄带网络到宽带网络的平滑演进。     

物联网多终端协同的应用场景及网络控制需求

在物联网环境下,随着终端技术的发展、用户拥有智能终端数量的增加、越来越多终端对近距离通信技术的支持,同一用户或不同用户终端之间,可以通过相互协同,提升单个用户终端的功能和性能,为用户提供更加智能化的业务体验。本文分析和列举了多终端协同的7种应用场景,并提炼出了3种多终端协同下的网络控制需求,为物联网多终端协同的网络控制技术研究奠定了基础。     

警用无线宽窄融合通信应用研究

警用无线通信由窄带向宽带化演进已是势在必行,通过宽窄带融合的方式实现警用无线通信系统的平滑演进已成为主流共识。利用多媒体融合通信平台实现宽带系统与窄带系统的互联互通,利用双模同号、宽窄互通加密等关键技术延续窄带用户拨号习惯,保证宽窄系统间语音传输的安全性。搭建宽窄融合通信实验局实现了宽窄融合的多类型业务应用,为我国公安的专网通信宽带化演进提供指导借鉴作用。     

基于视频通信增值业务的终端技术要求

随着视频通话业务不断应用在用户的各类终端上,越来越多的视频通信增值业务逐渐被研发出来,如何在各类视频终端上推广这些这些业务成为亟待解决的问题。这里描述的基于视频通信增值业务的终端技术要求从SIP信令要求、音视频编解码要求、终端界面设计要求等方面分析了在终端层面影响视频通信增值业务的关键技术点,包括:在SIP信令方面需要在视频通信过程中进行多次s媒体协商;视频终端需要支持CIF分辨率以上的视频编解码能力;以及视频终端界面用户交互要求等。     

开放平台下移动互联网终端设计方案的实现探究

随着移动互联网的快速发展,全球移动互联网用户超过了十亿,中国移动互联网用户正面临着井喷式增长,互联网行业进入了快速发展期。随着移动互联网应用范围不断扩大,已经成为了通信、娱乐、媒体、互联网等众多产业融合的焦点,宽带无线通信、互联网技术、移动通信技术在移动互联网业务中获得了极大的应用。移动互联网在发展趋势中,呈现出了技术多样化趋势。研究开放平台下移动互联网终端设计方案,对我国加强移动互联网终端研发能力、实际应用能力及标准化服务,推动移动通信进步,提高移动互联网业务具有极为重要的作用。     

IMS的网络定位和业务实现

IMS是NGN的IP多媒体业务部件,是为3G的IMS域用户和固定宽带用户提供融合业务的统一网络.对于固定宽带用户,软交换是IMS的一种实现.PSTN/窄带软交换与统一IMS分属不同的网络并且将长期并存.为宽带终端提供业务的软交换设备必然要成为统一IMS的一部分,覆盖固定宽带终端的网络将向统一IMS演进.本文还介绍了呈现、即时消息等业务服务器的组网方式以及基于IMS的语音融合业务的实现方案.     

一种宽带无线移动视频调度系统的设计与实现

无线宽带接入技术的发展已具备将传统窄带语音集群调度系统与宽带视频调度集成应用的技术基础.本文提出一种宽带无线移动视频调度系统的设计,无缝整合无线移动视频与原有固定视频监控系统[1],不但实现指挥中心对无线作业终端的统一音、视频调度通信管理,而且提供可自定义的、基于事件触发与时间触发的音、视频联动调度机制.该系统具备优异的灵活性与可扩展性,尤其适合突发与应急状态下的联动调度通信应用,满足民航机场等行业的运营指挥业务需要.     

基于网络中多终端融合通信业务实现研究

随着社会经济的变革发展,各个行业领域发生前所未有的变化,对网络的需求日益强烈,使得网络通信业务得到质的飞跃。网络通信出现的重要变化则是多终端融合通信业务实现,此项变化对于网络通信行业而言是一项革命性的转变,使用户体验与宽带水平之间存在的矛盾问题得以有效解决,使通信更加规范、标准之智能化。鉴于此,文章对网络中多终端融合通信业务实现展开分析研究,因此为相关人员提供帮助。     

ATM技术的应用———B－ISDN业务

△ＡＴＭ技术的应用———Ｂ－ＩＳＤＮ业务谭淑贞１宽带业务宽带业务是相对于窄带业务而言的，一般来说，对于速率低于２Ｍｂ／ｓ的通信业务统称窄带业务，如电话网、Ｎ－ＩＳＤＮ所提供的业务。对于高于２Ｍｂ／ｓ的通信业务，如帧中继业务、交换型多Ｍｂ／ｓ数据业务（...     

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