支持11ac的多功能家庭网关硬件方案设计

设计了一种家庭网关设备,可以实现PON（无源光网络）接入,同时提供有线上网和无线覆盖（WiFi 2.4 GHz 5.8 GHz）、电话、视频服务。用一个设备解决多个家庭设备的联网问题,而且速度较快。在周围用户较多的情况下,能够有较好地用户体验。由于此设备支持大功率WiFi11ac功能,输出功率达20 dBm,可以在2.4 GHz信号密集区域有效避开干扰,同时提供高达1.3 Gbit·s-1的连接速率,可以满足多用户大数据量传输的要求。     

一种VoWiFi业务平台建设方案简介

移动通信网络覆盖由于移动通信基站的投资与建设的时间成本限制，存在部分地理区域移动通信网络弱覆盖或者无覆盖的问题，影响了用户的语音和数据通信感知质量。基于WiFi共享技术横向打通电信多张网络，利用多网融合解决移动网络的覆盖盲区问题，解决用户移动语音业务/数据业务质差的问题，快速提升用户感知，节省移动网覆盖成本。     

WiFi分流EV-DO研究

将高流量基站特定区域的数据流量有目的地迁移到WiFi网络,对于缓解EV-DO的网络压力、提高WiFi网络的资源利用率都有着积极的意义。文章对WiFi和EV-DO作了对比,结合WiFi分流EV-DO的流程,论述了忙小区和忙用户的确定标准、分流用户的定位方法以及WiFi的覆盖方案,最后结合实例对分流效果进行了对比分析。     

WiFi5与WiFi6AP建设规模与经济效益的对比分析

阐述了WiFi技术的发展历程,对WiFi 6协议中的关键技术进行了介绍。选取国内某设备厂家WiFi 5和WiFi 6中主流的两款AP设备,结合两者性能参数进行了覆盖距离和接入容量的比较。以W公园为例,分别测算出使用WiFi 5和WiFi 6两种AP设备覆盖的建设规模,并结合当地实际对两种方案的工程投资进行了比较,预测出两种方案的价格平衡点,为现阶段WiFi 5和WiFi 6方案的选择提供参考。     

校园WiFi组网与覆盖方案

目前,校园WiFi网络覆盖是各大运营商激烈竞争的进驻场景.通过WiFi覆盖有线网未能到达的众多区域,让用户随时随地接入移动网络,享受其便利的服务.WiFi在当今校园组网中扮演着重要角色,用户对其日益亲睐.本文主要针对校园内各种场景建筑物的组网方式、覆盖方案进行探讨.     

浅谈宝鸡广电“全屋WiFi”技术应用

以“广电·智家”产品和大宽带业务安装调试中易出现的问题及用户使用中易出现的故障点，比照了“全屋WiFi”技术、无线覆盖中WiFi 6和5G的特点，区分场景应用及对象，对比宝鸡广电网络传媒有限责任公司业务开通安装中采用的2种解决方案分析，对用户终端配置需注意的问题提出建议。     

华为TD-LTE干扰的分类及优化方法解析

随着LTE网络的全面铺设,网络中出现的干扰问题也越来越明显,准确定位干扰源并及时进行优化调整,是提升全网覆盖质量、提高用户感知的关键。本文结合华为TD-LTE区域出现的各类干扰,探索了不同的优化方法。     

我国研发WiFi手机面世 可拨打VoIP电话

日前,我国已经成功开发出拥有完全自主知识产权并满足实际市场需求的GSM/WiFi双模手机。此款手机区别于其他普通手机的最大特征就是通过WiFi无线局域网(WLAN)实现了VoIP网络电话功能。用户只要身在机场、酒店、餐厅、办公场所或家庭等任何WLAN覆盖的区域之内,就能够免费或以低廉的资费拨打国内或国际长途电话。与早前应用于手机上的蓝牙技术不同,WiFi具有更大的覆盖范围和更高的传输速率,因此WiFi手机成为了目前移动通信业界的时尚潮流。由于WiFi的频段在世界范围内是无需运营执照的免费频段,因此WLAN无线设备提供了一个世界范…     

大数据分析与网络弱覆盖发现案例

网络弱覆盖严重影响用户感知,是运营商最为关注并需首要解决的问题之一。网络弱覆盖的发现来源主要有路测、用户投诉等,近年来,随着大数据采集与分析能力的提升,也成为了弱覆盖发现的重要手段之一。本文以某密集城区为例,介绍从基于Hadoop的大数据解析、大数据定位、到网络弱覆盖发现与优化建议的整个流程,给实际网络规划优化工作提供经验。     

2.4 GHz WiFi与Zigbee在同一网关中的共存研究

随着智能家居技术的快速发展,越来越多的智能网关设备进入用户家中,配合已有的WiFi网关设备,满足家庭中各种智能覆盖的使用场景。大多数情况下,用户家中既有智能网关设备,也有WiFi设备,使用较为复杂。为了更好地满足终端用户的需求以及降低成本,本文尝试将无线接入WiFi网关与智能家居网关合二为一,即将智能家居Zigbee部分与WiFi集成在一个网关设备中。在此种应用场景下,Zigbee和WiFi均工作在2.4 GHz频段时,同频干扰就无法避免。本文对二者的干扰进行了较为深入的测试和分析,并根据测试结果设计了规避方案。经过实践验证,设计的方案能够有效解决部分干扰,基本满足用户的使用要求。     

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.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

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.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.