移动无线传感器网络自适应信标交换算法思路探讨

针对移动无线传感器网络中周期性信标交换引起的通信暂忙现象,提出一种自适应信标交换算法。从现阶段的发展来看,移动无线传感器的应用范围非常广泛,对日常的工作具有非常重要的积极意义。移动无线传感器网络自适应信标交换算法是对原有算法的一种革新,原有的算法虽然能够应对较多的工作,但是在目前的发展当中,已经表现出了一定的不足,并且在精度方面有所下降,所以,要积极探究新的算法。     

一种基于RFID的便携式智能语音播放器设计

针对传统的红外电子导游系统的不足,采用RFID技术设计并实现了一种便携式智能语音播放器。在给出RFID便携式智能语音播放器的总体设计方案之后,分别对RFID模块、无线信号收发模块、控制器和解码模块进行了详细设计并给出了电路设计原理图;该播放器不仅体积小、感应灵敏,而且可以广泛应用在不同领域。     

小区智能红外探测报警系统

设计一种基于无线传感网络技术的小区智能红外探测报警系统。采用热释电红外传感器探测人员非法入室,利用无线传感网络技术将报警数据传送到小区值班室。给出了系统实现方案,设计了报警节点、报警主机、报警服务器和值班室监视软件。实验结果表明,系统运行良好,能够实现实时报警。     

无线Mesh网络的概念及关键技术

无线Mesh网络是一种新型的无线宽带接入网络,它融合了无线局域网和Adhoc网络的优势,具有自组网、自修复、多跳级联、节点自我管理等智能优势以及移动宽带、无线定位等特点,成为无线宽带接入的一种有效手段。文章简要介绍无线Mesh网络的概念和系统特性,详细阐述摩托罗拉Mesh技术的系统结构、频率配置和关键技术等。     

无线ATM网络的研究现状和发展趋势

该文介绍了无线ATM的技术原理及一种系统级的框架结构,探讨了有关移动ATM交换基础设施和无线接入子系统的关键设计问题。指出无线ATM技术未来发展方向——综合IP技术以及移动多媒体终端/应用。     

基于无线传感器网络的仓库智能安保系统设计

将无线传感器网络技术用于智能仓库安保系统。针对无线传感器网络技术和智能仓库安保系统的特点。设计了基于无线传感器网络的智能仓库安保系统的一整套系统和网络节点。该系统体现了无线传感器网络的特点。利用计算机处理信息,根据处理结果作出相应反应、处理。实验表明,该系统使用方便、稳定可靠。     

基于无线传感器网络的智能交通测速系统

介绍了一种基于无线传感器网络的交通检测系统,通过在路边布置两个距离已知的信标节点接收的RSSI值大小来判断移动节点的到达信标节点的时刻,因为距离越近RSSI值越大,所以当RSSI值达到最大时就是移动节点到达信标节点的时刻,最后根据已知的距离和分别到达两个信标的时刻计算出速度。文章对该测速系统进行了实物实验,并用MATLAB对实验数据进行处理,分析结果表明这个系统具有一定的实用性。     

多移动信标辅助的分布式节点定位方法

为提高移动信标辅助定位算法的定位精度,避免重复扫描待定位节点,提出了一种使用多个移动信标的定位方法。这些信标在遍历网络时保持一定相对位置关系,使用TDoA技术测距并为未知节点提供距离信息辅助其定位。提出了基于最优覆盖策略的2种移动信标路径规划方法。仿真结果表明,所提出的算法具有较高的定位精度,且所使用的移动路径性能较高。     

基于无线传感器网络的仓库智能安保系统设计

将无线传感器网络技术用于智能仓库安保系统.针对无线传感器网络技术和智能仓库安保系统的特点,设计了基于无线传感器网络的智能仓库安保系统的一整套系统和网络节点.该系统体现了无线传感器网络的特点.利用计算机处理信息,根据处理结果作出相应反应、处理.实验表明,该系统使用方便、稳定可靠.     

基于MR的无线移动智能网络优化平台的设计与实现

蜂窝移动通信网络的快速增长,使无线网络的优化设计问题日益重要。基于TD-SCDMA、GSM等无线移动网络的Abis或Iu-b接口中实时采集的信令MR帧,对MR帧进行同步解析,并由提取的帧结构中的数据,构建了无线移动智能网络优化平台。该无线移动智能网络优化平台利用MR测量报告信息能快速定位出TD-SCDMA移动通信网络当中的故障问题。该智能网络优化平台提供了一种新的越区检测算法实现,并能够对越区覆盖和弱覆盖进行检测和优化。     

Beaconing Approaches in Vehicular Ad Hoc Networks: A Survey

A vehicular ad hoc network (VANET) is a type of wireless ad hoc network that facilitates ubiquitous connectivity between vehicles in the absence of fixed infrastructure. Beaconing approaches is an important research challenge in high mobility vehicular networks with enabling safety applications. In this article, we perform a survey and a comparative study of state-of-the-art adaptive beaconing approaches in VANET, that explores the main advantages and drawbacks behind their design. The survey part of the paper presents a review of existing adaptive beaconing approaches such as adaptive beacon transmission power, beacon rate adaptation, contention window size adjustment and Hybrid adaptation beaconing techniques. The comparative study of the paper compares the representatives of adaptive beaconing approaches in terms of their objective of study, summary of their study, the utilized simulator and the type of vehicular scenario. After implementing the representatives of beaconing approaches, we analysed the simulation results and discussed the strengths and weaknesses of these beaconing approaches with regard to their suitability to vehicular networks. Finally, we discussed the open issues and research directions related to VANET adaptive beaconing approaches.     

Evaluating the communication performance of an ad hoc wirelessnetwork

Adaptive and self-organizing wireless networks are gaining in popularity. Several media access and routing protocols were proposed for such networks and the performance of such protocols were evaluated based on simulations. In this paper, we evaluate the practicality of realizing an ad hoc wireless network and investigate on performance issues. Several mobile computers were enhanced with ad hoc routing capability and were deployed in an outdoor environment and communication performance associated with ad hoc communications were evaluated. These computers periodically send beacons to their neighbors to declare their presence. We examined the impact of varying packet size, beaconing interval, and route hop count on route discovery time, communication throughput, end-to-end delay, and packet loss. We had also performed mobility experiments and evaluated the route reconstruction time incurred. File transfer times associated with sending information reliably (via TCP) over multihop wireless links are also presented. The experimental results obtained revealed that it is feasible to augment existing wireless computers with ad hoc networking capability. End-to-end performance in ad hoc routes are less affected by beaconing intervals than packet size or route length. Similarly, communication throughput is more dependent on packet size and route length with the exception at very high beaconing frequencies. Packet loss, on the other hand, is not significantly affected by packet size, route length or beaconing frequency. Finally, route discovery time in ad hoc wireless networks are more dependent on channel conditions and route length than variations in beaconing intervals     

无线智能报靶系统设计与实现

提出了一种利用摄像头、便携式计算机和无线路由器等搭建无线报靶系统,并利用图像识别算法实现智能报靶,所设计方案具有便携和性价比高等特点。经过图像预处理、确定自动阈值、二值化处理和轮廓提取等环节实现了弹孔的自动识别。     

Autonomous and adaptive beaconing strategy for multi‐interfaced wireless mobile nodes

Ad hoc wireless communications rely on beaconing to manage and maintain several network operations and to share relevant network parameters among network nodes. Beacon frames are sent at the start of each beacon interval. The frequency of beaconing depends on whether beacon intervals are fixed size or may be adapted and regulated according to the perceived network and workload conditions. On the other hand, current mobile nodes usually embed several heterogeneous wireless interfaces that urge the design of an adaptive beaconing strategy. In this paper, we propose an autonomous and adaptive beaconing strategy for multi‐interfaced mobile wireless nodes that is capable of regulating the beacon interval size dynamically according to the perceived network conditions. The proposed strategy is based on a joint dynamic estimation of both the announcement traffic indication message (ATIM) window and the beyond‐ATIM window sizes for each beacon interval. Extensive simulations were conducted using OMNeT++ to ascertain the improvements achieved by autonomously regulating the entire beacon interval to take into account the network and workload conditions. Obtained results showed that the two proposed approaches improve significantly the efficiency of the network in terms of throughput, end‐to‐end delay, and power consumption. The proposed fixed beacon interval (fixed‐BI) approach stands as an enhanced version of the power‐saving multi‐channel MAC protocol (PSM‐MMAC). The proposed variable beacon interval (variable‐BI) approach, which regulates dynamically both of the ATIM and the beyond‐ATIM windows, outperforms both the fixed‐BI and the PSM‐MMAC. In particular, under nominal traffic loads, the end‐to‐end delay of the variable‐BI is much lower than those provided by the fixed‐BI and PSM‐MMAC. Copyright © 2015 John Wiley & Sons, Ltd.     

基于3G网络的智能交通视频监控系统

设计了一款基于3G网络的智能交通视频监控系统,包括前端视频采集部分、3G无线网络传输部分和后端监控管理服务平台三个部分。系统对实时路况车辆进行视频采集、经过无线传输,最终在PC终端界面上进行实时播放、存储,并实现了车辆违规判断、报警等功能。本系统有轻巧便捷、安装简易、运营成本低等优势,具有广阔的应用前景,是智能交通监控系统的新型发展模式。     

面向展会园区信息服务的射频识别和无线异构组网实例

本文面向展会园区信息服务,针对复杂环境下的RFID识别和实时数据采集分析应用,基于WiMAX+WiFi联合组网,并结合Mesh网结构,提出了多种接入方式相结合的分层无线异构网络,并基于此实现了RFID信息平台和智能监控系统。通过实例详细介绍了WiFi网络规划。本文提出的无线异构网络已在示范平台上进行了业务能力验证。     

A fuzzy logic approach to beaconing for vehicular ad hoc networks

Vehicular Ad Hoc Network (VANET) is an emerging field of technology that allows vehicles to communicate together in the absence of fixed infrastructure. The basic premise of VANET is that in order for a vehicle detect other vehicles in the vicinity. This cognizance, awareness of other vehicles, can be achieved through beaconing. In the near future, many VANET applications will rely on beaconing to enhance information sharing. Further, the uneven distribution of vehicles, ranging from dense rush hour traffic to sparse late night volumes creates a pressing need for an adaptive beaconing rate control mechanism to enable a compromise between network load and precise awareness between vehicles. To this end, we propose an intelligent Adaptive Beaconing Rate (ABR) approach based on fuzzy logic to control the frequency of beaconing by taking traffic characteristics into consideration. The proposed ABR considers the percentage of vehicles traveling in the same direction, and status of vehicles as inputs of the fuzzy decision making system, in order to tune the beaconing rate according to the vehicular traffic characteristics. To achieve a fair comparison with fixed beaconing schemes, we have implemented ABR approach in JIST/SWANs. Our simulation shows that the proposed ABR approach is able to improve channel load due to beaconing, improve cooperative awareness between vehicles and reduce average packet delay in lossy/lossless urban vehicular scenarios.     

SNMS: an intelligent transportation system network architecture based on WSN and P2P network

With the development of city road networks, the question of how to obtain information about the roads is becoming more and more important. In this article, sensor network with mobile station (SNMS), a novel two-tiered intelligent transportation system (ITS) network architecture based on wireless sensor network (WSN) and peer-to-peer (P2P) network, is proposed to provide significant traffic information about the road and thereby, assist travelers to take optimum decisions when they are driving. A detailed explanation with regard to the strategy of each level as well as the design of two main components in the network, sensor unit (SU) and mobile station (MS), is presented. Finally, a representative scenario is described to display the operation of the system.     

具有新型网络协调吞吐机制的智慧医疗健康监测系统

将无线通信网络技术引入智慧医疗、智慧家庭等前沿的智慧城市技术领域,设计并实现了一种支持多监测点自由接入的无线便携式生物电信号智能监测与显示系统.提出了一种异步缓存机制,降低系统运算复杂度及开销,解决实时监测数据与现有无线网络接入问题;改进无线网络数据传输点协调控制(PCF)机制,提出优先级轮询及动态调整重发上限等技术手段,提高无线网络的通信效率,保证多用户情况下的实时监测与波形显示稳定性.通过NS2仿真及系统整体实测,表明设计能够达到连续不间断的无线监测与视频显示效果,与现有采用DCF和PCF网络机制相比,传输延迟降低5％和1％,且接入的设备数量越多优势越体现.该设计大幅改善设备使用灵活性与实用性,突破现有设备因体积及有线连接等方式只能局限于医疗机构等场地使用的限制,适用于智慧城市对智能健康监护的多用户、可移动、无线化、远程诊断与记录发展需求.