物联网原理与基于RFID的物物互联模式研究

在论述物联网原理基础上,分析物联网环境下的RFID技术、无线传感网络技术和GPS等主流信息识别技术,研究了基于RFID的物物互联模式和以RFID技术为主导的混合型物物互联模式,并探讨了不同互联模式下物联网功能实现的具体过程及其应用前景。     

GSM-R系统在铁路无线通信系统中的应用与发展

随着我国铁路建设新一轮高潮的到来,今后新建的客运专线,城际铁路,高速铁路,均采用GSM-R系统作为其综合无线通信系统,本文为此具体探讨了GSM-R网络的系统结构,在铁路运输系统中的作用,主要业务功能,未来发展方向和业务应用。     

浅谈无线通信技术的发展

文章介绍了无线通信技术从早期的长波、中波、短波通信到卫星通信、微波通信的发展过程,同时对无线通信方式中的移动通信的发展阶段进行了详细的叙述,还对未来无线通信技术发展的几个方向进行了详细的讲解,从而使读者对无线通信技术的发展有一个比较详细的了解。     

基于干扰矩阵的高密WLAN场景下集中式功率控制

针对高密无线局域网（WLAN）场景中系统干扰严重导致吞吐量降低的问题,提出了一种集中式动态发射功率控制算法（CDTPC）。接入控制器（AC）依据接入点（AP）定时上报的信道扫描报告和邻居报告建立干扰矩阵,通过分析干扰矩阵确定干扰源AP集和覆盖漏洞AP集,并对干扰源AP和覆盖漏洞AP进行动态功率控制,在保障覆盖的情况下减小WLAN系统内干扰、提高网络整体吞吐量。仿真表明：在高密WLAN场景中,使用CDTPC算法进行功率控制前后各AP吞吐对量均有所提高,系统整体吞吐量提高了41.5%.     

无线传输中短码长喷泉码的度分布优化算法

数字喷泉码是针对大规模网络数据分发而提出的一种新的信道编码方式。度分布是决定数字喷泉码译码性能的关键因素。为提高译码性能,针对应用于无线信道的喷泉码提出了一种度分布优化的算法。首先,根据理想孤子分布和鲁棒孤子分布产生度值序列,然后将该度值序列截短,在此基础上根据优化算法求解该序列中每个度值的最优概率,最后得到优化的度分布。仿真结果表明,本算法产生的度分布进行编译码产生的误码率低于鲁棒孤子分布和固定度分布,提高了译码性能。     

Network impacts of distance-based road user charging

Distance-based road user charging is being seen as one potential mechanism to implement national road charging schemes. This paper investigates the design aspects of universal distance-based charging schemes and incorporates procedures within a detailed network supply model to represent how a range of different permutations of distance-based charges across a given network (charging regimes) affect route-choice, travel characteristics and demand for road space. The results suggest that distance-based charging can reduce number and length of trips, congestion, accidents and pollution, and provide net economic benefits and revenues. However, these benefits are not found to be uniform throughout the network. Their magnitude largely depends on the charge level, the hierarchy of charges across the network, and the difference between the charge levels.     

Roadmapping 3G mobile TV: Strategic thinking and scenario planning through repeated cross-impact handling

In order to deal with growing uncertainties emerging in the 3G wireless industry and to preserve their competitiveness, managers involved in the wireless value network should identify future success very early and develop their strategic planning on time. This study, based on a Scenario Evaluation and Analysis through Repeated Cross impact Handling, allows the generation of both qualitative and quantitative scenarios and can be used as an operative planning tool. The dynamic forces driving the scenario are based on the main principles of system thinking and multiple features. The probabilistic data have been elicited with the help of 40 executives in USA and Europe working for companies in the different phases of the wireless value chain. Findings allow to identify basic trends and uncertainties useful to develop corporate or business strategies.     

基于BWAS的无线传感器网络静态分簇路由算法

为提高路径搜索效率,避免动态分簇较多的能量消耗,提出了基于最优-最差蚂蚁系统(BWAS )的无线传感器 网络静态分簇路由算法。BWAS是对蚁群算法的改进,在路径搜寻过程中评价出最优最差蚂蚁 ,引入奖惩机制,加快了路径搜索速度。通过无线传感器网络静态分簇、簇内动态选举簇头 ,在簇头节点间运用BWAS算法搜寻从簇头节点到汇聚节点的多跳最优路径,能减少路径寻优 能量消耗,实现均衡能量管理,延长网络寿命,且具有较强的鲁棒性。通过与基于BWAS的 动态分簇和基于蚁群算法的动态分簇路由的仿真实验相比较,证实了本算法的有效性。     

无线传感器网络密钥管理研究进展

分析了当前无线传感器网络密钥管理协议设计中所存在的主要问题,在对具有代表性 的最新研究成果进行系统论述的基础上,全面分析了其利弊以及适应性问题。考虑到传感器 网络应用背景的细化和结构、功能的多元化,提出了今后的研究方向。     

Entering the mobile service market via mobile platforms: Qualcomm's BREW platform and Nokia's Preminet platform

The mobile telecommunication market has evolved from simple voice to multimedia services. In the past, the primary players in mobile services were local operators in different countries; international telecommunication vendors, such as Qualcomm and Nokia, were seldom involved in the mobile service market. In order to enter this market, Qualcomm and Nokia have separately introduced their mobile application platforms, called respectively BREW and Preminet. This paper examines how the two companies attempt to share the mobile service market through their mobile platforms and internationalized business models. This paper also analyzes their mobile platforms’ business models and their strategic implications.