PKI技术在移动数据业务安全中的应用

本文介绍了公钥基础设施（PKI）技术,并通过分析移动数据业务的特点及所面临的威胁,提出了采用PKI相关技术来加强数据业务的安全性,即采用代码签名技术来解决客户端代码的安全性问题,采用移动签名技术来解决各种数据业务中的用户交易确认问题。     

手机控制小车的创新设计

本设计采用单片机对HT9170双音多频解码芯片的控制,来实现手机远程控制小车的智能运行。以两个电机来驱动小车,采用反射式红外光电传感器ST178来实现小车自动循迹功能,通过超声波测距来实现语音播报,其中手机遥控部分的按键可通过一个数码管来显示。     

采用固态继电器的交流电子调压器

常用的小型交流电子调压器,大都采用继电器来切换自耦变压器上的抽头来实现调压的。由于继电器是采用机械触点方式,故存在触点氧化、接触不良、易产生火花、寿命短等缺点。本文介绍采用固态继电器来代替一般的继电器,就可避免上述缺点。不足的是目前固态     

无线传感网络中低功耗处理器的设计和优化

采用90nm工艺设计实现了应用于无线传感网络中的低功耗处理器.为了减小功耗,采用了以下两种方法:(1)采用门控时钟技术来降低动态功耗;(2)采用多阈值电压单元库来减小漏电功耗.通过比较给出了设计优化结果.     

无线传感网络中低功耗处理器的设计和优化

采用90nm工艺设计实现了应用于无线传感网络中的低功耗处理器.为了减小功耗,采用了以下两种方法:(1)采用门控时钟技术来降低动态功耗;(2)采用多阈值电压单元库来减小漏电功耗.通过比较给出了设计优化结果.     

无线传感网络中低功耗处理器的设计和优化

采用90nm工艺设计实现了应用于无线传感网络中的低功耗处理器. 为了减小功耗，采用了以下两种方法： (1）采用门控时钟技术来降低动态功耗； (2）采用多阈值电压单元库来减小漏电功耗. 通过比较给出了设计优化结果.     

基于DRM和P2P技术的内容分发模式

由于盗版光盘和网络非法下载影片视频的盛行,内容发行商迫切需要采用新的技术来保护合法的视频文件分发。论文提出了一种全新的基于DRM和P2P技术的内容分发模式,采用数字版权管理(DRM)来对视频加密和对用户进行认证,采用P2P技术来低成本快速分发视频文件,收到了良好的效果。     

电网GIS平台内存集群数据分区策略

电网GIS平台通过构建内存集群来保障数据访问和计算的实时性。其内存集群根据空间数据、台账数据和配置数据的不同特点进行数据分区。主体采用网格化的方式划分数据,适当采用冗余存储来提高数据的读取效率,支持增加集群节点数来扩容。     

一种基于预约的无线传感器网络MAC协议

无线传感器网络要求的能量高效,低延时,使得MAC协议的设计充满挑战。近来已经提出了很多基于簇的MAC协议,为减少冲突在簇内部采用TDMA方式来协调簇内各个节点的传输。提出了一种在采用簇结构的基础上,使用预约方式来发送数据的R-MAC（Reservation-MAC）协议。当争用节点少的时候,采用随机争用方式来预约数据的发送;在争用节点多的时候,采用时隙争用方式来预约数据的发送。分析表明,R-MAC能够有效地降低能耗和减少延迟。     

单目视觉车道偏离报警系统

本设计采用了一种使用未标定相机来测量车辆和车道中心的横向偏离量的方法来达到车辆车道偏离报警的目的。首先采用直线模型来表示车道,使用sobel边缘检测算法来测量车道边缘,利用Hough变换检测出实时图像中的直线车道,然后估量出车辆的横行偏移量,最后利用偏离横越时间来测量丰道是否偏离,提前检测车道车道横越,从而达到车辆偏离报警的目的。     

Universal personal communications: Emergence of a paradigm shift in the communications industry

It is postulated that today we are in the midst of a major paradigm shift in the communications industry. The essence of this paradigm shift is a transition from today's universal telephone service which has been perfected over the past 100 years, to a future communication service environment, referred to as universal personal communication. Under this new paradigm, communications will be person based in contrast to the predominantly location-based communication environment of today. Societal trends, evolving global standards for communication, regulatory policies, and emergent technologies are seen as the forces driving such a transition. Universal personal communications will be characterized by flexible access to universal services permittingmore enduser control which will result in personalization and customization of such services. Furthermore, the centralized intelligence focus of today's communication networks needs to evolve toward a focus where network intelligence can be migrated to the periphery of the core transport network. The viability of universal personal communication will be critically dependent upon how well it addresses the end customer value proposition. Two key elements of this proposition are transparency of mobility and personalization of service environments. A zonal service environment model which classifies and characterizes these various service environments in terms of common communication parameters is proposed. This model is built around hierarchical structures for both cellular and digital wireless transmission, and can be viewed as critical towards the realization of transparent mobility management and personalization of services.     

ACTS MOBILE TERMINALS

The development of the advanced communications technology satellite (ACTS) mobile terminal (AMT) and its follow-on, the broadband aeronautical terminal (BAT), have provided an excellent testbed for the evaluation of K- and Ka-band mobile satellite communications systems. Such systems have proved viable for many different commercial and government applications. Combining emerging satellite communications technologies such as ACTS' highly focused spotbeams with the smaller, higher-gain K- and Ka-band antenna technology, results in system designs that can support significantly higher throughput capacity than today's current commercial systems. An overview of both of these terminals is presented in this paper.     

一种基于激光通信浮标的潜艇水下双工通信方式

对现有潜艇水下通信技术进行比较分析,提出一种采用无线脉冲激光作为通信载波的系留浮标潜艇水下双工通信方式,并简要描述了该通信方式的应用体制及其可行性。     

卫星移动通信系统的发展思考

本文回顾了现代中低轨道卫星移动通信系统的发展历程、在发展过程中存在的问题,全面分析了各行业、部门对卫星移动通信系统的使用需求,并展望未来发展前景,提出了未来卫星全球人个移动通信系统的发展策略。     

地震应急卫星通信指挥车通信系统设计

“十五”期间,江苏省地震局完成了应急指挥技术系统的建设,江苏地震现场也配置了箱式应急卫星通信系统,这些都有力的提升了地震现场应急的通信保障能力。针对该箱式系统存在的缺点,利用移动通信车的优点,在简述地震应急卫星通信指挥车通信系统需要实现的功能基础上,详细介绍了江苏省地震现场应急卫星通信指挥车通信系统设计,对实际应用中出现的问题进行了总结,并提出了解决方案,最后对通信指挥车今后的应用前景进行了说明。     

Dynamic Base Station Selection for Personal Communication Systems with Distributed Control Schemes

Distributed control schemes allow base stations in personal communication systems to be placed at locations corresponding to high expected traffic. This flexible base station placement creates significant overlapping coverage areas that can be utilized to improve system performance [1]. A new technique for dynamic base station selection in systems with overlapping cells is considered and its effect on traffic performance is characterized. The technique realizes robust performance for personal communication systems in fluctuating and heavily tapered traffic. A mathematical analysis based on a state transition model is used to evaluate performance of a system that employs the proposed technique. The results indicate that improved blocking probability and carried traffic performance are obtainable. Computer simulations were undertaken confirm the analytical results.     

移动数据：开创移动服务新天地

固定网数据业务的发展经历将在移动网上重演,其发展潜力将更大于固定网;充分重视短消息业务是运营商将来生存和发展的重要基础;移动Ｉｎｔｅｒｎｅｔ是移动数据发展的必然趋势;日本ｉＭＯＤＥ移动上网的成功策略给人们很多启示。     

我国光纤通信系统传输设备产业现状与发展建议

光纤通信在中国已有20余年的发展史，拥有大量的科研成果，但尚未能形成产业。建议高度重视其问题，把关系国家命脉的信息控制和管理权掌握在自己手中。     

卫星通信在跨区域应急救援中的应用

介绍应急通信系统的组成及主要功能,描述了在应对突发事件过程中,事故现场与指挥中心之间语音、视频及数据业务的实现方式。最后,结合消防卫星网研究了跨区域应急救援卫星通信中的应用。     

Mobile and Personal Communications in the 60 GHz Band: A Survey

This paper intends to present a summary of the technical issues arising in the exploitation of the 60 GHz mm-wave band for mobile and personal communications. The most significant applications proposed so far are surveyed, with particular emphasis placed on recent experimentation about millimeter-wave propagation for road/railway transportation as well as indoor scenarios. As a case study, the capacity of a (micro-)cellular Code Division Multiple Access (CDMA) network in the 60-GHz band is also evaluated in detail.