Wireless location privacy protection

After more than two decades of hype, computing and communication technologies are finally converging. Java-enabled cell phones run a host of powerful applications including mobile Internet access, while many notebook computers offer high-speed wireless connectivity as a standard feature. The big decision when purchasing a PDA is whether to get integrated cellular service or Wi-Fi capability. Location-based services are emerging as the next killer app in personal wireless devices, but there are few safeguards on location privacy. In fact, the demand for improved public safety is pushing regulation in the opposite direction. Today, when a person reports an emergency from a landline phone by dialing 911 in the United States or 112 in Europe, the system displays the caller's phone number and address to the dispatcher. The US Federal Communications Commission has mandated that, by December 2005, all cellular carriers be able to identify the location of emergency callers using mobile phones to within 50 to 100 meters. However, how cellular carriers and other businesses will use this capability remains open to question. The article looks at some of the areas this capability affects, including: privacy risks; economic damages; location-based spam; intermittent connectivity; user interfaces; network privacy; and privacy protection.     

Blind evaluation of location based queries using space transformation to preserve location privacy

In this paper we propose a fundamental approach to perform the class of Range and Nearest Neighbor (NN) queries, the core class of spatial queries used in location-based services, without revealing any location information about the query in order to preserve users’ private location information. The idea behind our approach is to utilize the power of one-way transformations to map the space of all objects and queries to another space and resolve spatial queries blindly in the transformed space. Traditional encryption based techniques, solutions based on the theory of private information retrieval, or the recently proposed anonymity and cloaking based approaches cannot provide stringent privacy guarantees without incurring costly computation and/or communication overhead. In contrast, we propose efficient algorithms to evaluate KNN and range queries privately in the Hilbert transformed space. We also propose a dual curve query resolution technique which further reduces the costs of performing range and KNN queries using a single Hilbert curve. We experimentally evaluate the performance of our proposed range and KNN query processing techniques and verify the strong level of privacy achieved with acceptable computation and communication overhead.     

基于神经网络的无线传感器网络数据融合算法_cg10000147修改稿

为减少无线传感器网络的通信量,降低能量消耗,设计了一种基于神经网络的数据融合算法(BPNDA),该算法将BP神经网络和传感器网络分簇路由协议有机结合,将每个簇设计成一个神经网络模型,通过神经网络提取原始数据中的少量特征数据,然后将特征数据发送给汇聚节点,从而提高数据收集效率,延长网络生存时间。仿真实验证明,与LEACH算法相比,该算法可有效减少网络通信量,降低节点能耗。     

无线传感器网络在桥梁健康监测中的应用研究

针对无线传感器网络技术在桥梁结构健康监测中的应用,研究并开发了基于无线传感器网络的桥梁结构健康监测系统.采用能量均衡分簇路由算法、时间同步算法和能量管理算法,组建了低功耗、节点能量消耗均衡、具有多跳路由结构的无线传感器网络.同时,应用加速度传感器检测桥梁振动的加速度数据,通过FFT变换由加速度数据得到桥梁的固有频率,并根据固有频率分析桥梁的健康状况.系统在公路高架桥中进行了应用试验,试验结果表明,系统便携性好,监测数据可靠.     

无线传感器网络

无线传感器网络被誉为21世纪四大高新技术之一。文章对无线传感器网络与传统网络的区别、技术特点和体系结构进行了探讨,重点针对无线传感器网络的现有各层协议进行了分析比较,最后,针对无线传感器网络发展所需的关键技术,提出来来我们重点研究的几个亟待解决的技术问题。     

无线传感器网络

集成了传感器、微机电系统和网络三大技术而形成的传感器网络是一种全新的信息获取和处理技术.在简要介绍传感器网络体系结构的基础上,分析和展望了一些有价值的应用领域.结合已有研究,总结并详细阐述了包括低功耗路由技术和介质访问控制方法等在内的热点研究问题.最后,针对应用需求,提出了几点研究设想.     

基于有线长链解决传感器网络的能量空洞

研究了"能量空洞"现象,基于环模型,通过在网络中添加少量有线长链来缓解能量空洞,延长网络的生命周期.在环C2(环C2是半径为r2和r1的圆形重叠区域)内添加一些与sink直接相连的有线长链,将环C2内的部分数据通过有线长链向sink直接传送,从而降低了靠近sink节点的能量消耗.理论分析和仿真实验表明,该方法能够极大地延长网络的生命周期.     

无线传感器网络数据传输延时分配算法

为了提高箭载无线传感网络对火箭温度、冲击、热流等物理参数的处理能力,需对所采集的数据进行自适应延时分配,因此设计一种基于时隙窗口间隔均衡控制的无线传感器网络数据传输延时分配算法。构建火箭温度、振动、冲击等参数的数据采集模型,采用分布式网格均衡配置方法对无线传感器网络中的节点进行均衡部署;结合最短路径寻优方法使数据采集过程中的信道分配达到均衡,构建数据采集最短路径寻优控制模型,采用输出比特序列重组方法进行数据采集过程中的传输延迟配置;结合码元调节技术对数据传输进行自适应扩频调节,利用时隙窗口间隔均衡控制方法实现无线传感器网络数据传输延时分配。实验结果表明,采用该方法进行无线传感器网络数据传输延时分配的自适应性较好,输出稳定性较强、分配输出错误率低,有效性更强。     

一种基于多路数据融合的WSN路由协议

提出了一种基于多路数据融合的无线传感器网络路由协议,介绍了该协议运用的数据融合等相关技术,叙述了该协议的实现过程,并运用仿真工具评估了该协议的性能指标。仿真结果表明,由于使用了该协议,节省了网络节点能量,延长了网络的生存周期。     

无线传感网络中使用动态代理的节点收敛算法

This paper proposes fault tolerant algorithms for routing mobile agents in a single channel wireless sensor network which cover every node in the network. These algorithms use local knowledge (assume no knowledge of global deployment or topology, etc). We propose the algorithms and show mathematical analysis to support our claims. The paper ends with simulation studies and discussion of results.     

Range-Free Localization Using Expected Hop Progress in Wireless Sensor Networks

Localization algorithm continues to be an important and challenging topic in today's wireless sensor networks (WSNs). In this paper, a novel range-free localization algorithm using expected hop progress (LAEP) to predict the location of any sensor in a WSN is proposed. This algorithm is based on an accurate analysis of hop progress in a WSN with randomly deployed sensors and arbitrary node density. By deriving the expected hop progress from a network model for WSNs in terms of network parameters, the distance between any pair of sensors can be accurately computed. Since the distance estimation is a key issue in localization systems for WSNs, the proposed range-free LAEP achieves better performance and less communication overhead as compared to some existent schemes like DV-Hop and RAW. In addition, we study the effect of anchor placement on the algorithm performance by deriving the corresponding mean position error range. Extensive simulations are performed and the results are observed to be in good agreement with the theoretical analysis.     

利用GIS和无线传感器网络的环境监测系统

环境传感器网络适于用来研究灾害反映系统得的基本过程和发展状况。GIS是可以用来集成、存储和分析以及可视化显示地理相关数据的计算机系统。无线传感器网络是利用传感器来监测物理和环境信息的自动互联的空间分布的电子设备。本文描述了这种技术的有机结合,用来实时监测城市汽车尾气的监测系统,可以创建与GIS技术结合的城市汽车尾气污染的实时监测地图。     

利用GIS和无线传感器网络的环境监测系统

环境传感器网络适于用来研究灾害反映系统得的基本过程和发展状况.GIS是可以用来集成、存储和分析以及可视化显示地理相关数据的计算机系统.无线传感器网络是利用传感器来监测物理和环境信息的自动互联的空间分布的电子设备.本文描述了这种技术的有机结合,用来实时监测城市汽车尾气的监测系统,可以创建与GIS技术结合的城市汽车尾气污染的实时监测地图.     

基于双模糊逻辑的无线传感器网络分簇算法

为降低无线传感器网络的能量消耗,延长网络生命周期,提出基于双模糊逻辑的无线传感器网络分簇算法(DFCP)。模糊逻辑一综合了节点剩余能量和节点与基站距离2个参数,确保输出高能量低能耗的节点竞争簇头的优势;模糊逻辑二综合了节点度与簇内平均节点能耗值2个参数,确保输出以簇为单位的局部能耗最小。簇生成阶段,基于非概率模式的延时机制保证了簇簇之间的均匀分布。通过与其他算法(LEACH、ECPF)对比,仿真结果表明:DFCP能克服LEACH协议运行下的网络簇分布不均、低能量节点担任簇头等缺点,并降低网络能量消耗;当网络中节点能量不一致时,DFCP运行下的网络簇头位置分布、网络局部能耗均衡优于ECPF。     

Distributed Localization Using a Moving Beacon in Wireless Sensor Networks

The localization of sensor nodes is a fundamental problem in sensor networks and can be implemented using powerful and expensive beacons. Beacons, the fewer the better, can acquire their position knowledge either from GPS devices or by virtue of being manually placed. In this paper, we propose a distributed method to localization of sensor nodes using a single moving beacon, where sensor nodes compute their position estimate based on the range-free technique. Two parameters are critical to the location accuracy of sensor nodes: the radio transmission range of the beacon and how often the beacon broadcasts its position. Theoretical analysis shows that these two parameters determine the upper bound of the estimation error when the traverse route of the beacon is a straight line. We extend the position estimate when the traverse route of the beacon is randomly chosen in a real-world situation, where the radio irregularity might cause a node to miss some crucial coordinate information from the beacon. We further point out that the movement pattern of the beacon plays a pivotal role in the localization task for sensors. To minimize estimation errors, sensor nodes can carry out a variety of algorithms in accordance with the movement of the beacon. Simulation results compare variants of the distributed method in a variety of testing environments. Real experiments show that the proposed method is feasible and can estimate the location of sensor nodes accurately, given a single moving beacon.     

无线传感器网络中传感器节点的布置

在无线传感器网络中，传感器节点收集本地数据，通常通过其它节点将数据转发给基站，因而离基站越近的节点，消耗的能量越多．如果采用通常的方法，即均匀布置传感器节点，则基站附近的节点将很快消耗完能量，基站也就无法收集数据．本文通过研究无线传感器网络中的能量消耗，得到了一个布置传感器节点的密度函数，按此函数布置传感器节点可以有效地延长系统的生命期．理论分析和模拟结果表明，本文的布置方案将系统生命期提高到均匀布置方案的3R/2t倍，这里t为传感器节点的通信距离，R为传感器节点的分布区域半径．     

无线传感器网络的管理

无线传感器网络是一个资源受限、应用相关的任务性网络,与现有网络特性显著不同,传统的网络管理不再适用于无线传感器网络。本文在简要说明无线传感器网络基本特性和面临挑战的基础上,给出了一个通用的无线传感器网络管理框架,并详细说明了各部分的内容和研究进展,最后探讨了无线传感器网络管理进一步的发展方向。     

WSN中一种基于多sink的快速数据收集算法

数据收集问题是无线传感器网络中的研究热点之一。数据收集方式会影响数据到达sink的准确度、延迟以及网络的能量消耗。针对时间响应和数据准确度要求高的应用,提出了一种基于多sink的快速数据收集算法（QDGA）。sink利用已知的全局信息和计算能力构建出基于最小度的数据收集森林进行任务分发,得到网格粒度最优的数据收集策略,网格内的普通节点通过时隙分配来进行数据收集,并可以根据自身的局部信息动态调整数据收集路径。仿真实验表明,相对于已有的方法,QDGA在保证网络生命周期的前提下,能够有效降低延迟以及提高数据收集的准确率。     

距离交会算法在无线传感网络节点定位中的应用

Knowing the locations of nodes in wireless sensor networks (WSN) is essential for many applications. Nodes in a WSN can have multiple capabilities and exploiting one or more of the capabilities can help to solve the localization problem. In this paper, we assume that each node in a WSN has the capability of distance measurement and present a location computation technique called linear intersection for node localization. We also propose an applied localization model using linear intersection and do some concerned experiments to estimate the location computation algorithm.