Sensor virtualization for underwater event detection

Distributed event detection is a popular application in Underwater Wireless Sensor Networks (UWSNs). The Base Station (BS) collects the measurements from multiple sensor nodes, and makes a decision based on the sensors’ reports. However, due to the unpredictable moving of underwater sensor nodes and interference among multiple events, it is difficult to guarantee the accuracy of event detection. In this paper, we propose a sensor virtualization approach to deal with the event detection problem in UWSNs. The final decision making at the BS will be implemented with the reports of multiple virtual sensors. Although the events may happen in a large scale, the locations where the events happen are relatively sparse in the underwater environment. Consider the sparse property of events, we employ the technique of compressive sensing to recover the original signal from the correlated sensors’ measurements. Through a proper signal reconstruction, the accurate event detection can be reached with a remarkable low sensing overhead. We implement the sensor virtualization based on the compressive sensing technique. Our approach is suitable for the high dynamic topology of UWSN, and it can improve the accuracy of event detection and reduce energy consumption in UWSNs.     

边界节点对无线传感器网络连通性的影响

无线传感器网络的连通性是确保节点成功组网的基础,相对于内部节点,边界节点对无线传感器网络的连通性有着更大的影响.本文以节点的有效通讯面积为基础,通过理论推导,分析了边界节点的连通性和网络的整体连通性,而后通过仿真研究,分析了存在边界节点与消除边界效应后的网络连通度分布、连通度期望和网络是κ点连通的概率,从而说明了边界节...     

Pair-Wise Collision-Based Underwater Time Synchronization

Time synchronization is a critical issue for Underwater Wireless Sensor Networks (UWSN). Although numerous time synchronization algorithms have been proposed for terrestrial wireless sensor networks, none of them could be applied to UWSN directly. This is because underwater time synchronization offers two fundamental challenges compared with terrestrial wireless sensor networks, i.e., (1) long propagation delay and (2) sensor node mobility. We propose a novel time synchronization approach called Coll-Sync to address the above challenging problems, which is a pair-wise collision-based time synchronization scheme for mobile underwater acoustic sensor networks. Coll-Sync adopts collision and packet meetings in a long propagation process to eliminate the effect of node mobility. In this paper, we indicate that collision and packet meetings contain highly useful information that can be leveraged to improve time synchronization. Through comprehensive experiments, we show that our proposed Coll-Sync greatly outperforms existing time synchronization schemes in both precision and energy saving.     

WSNs中基于Voronoi图的分布式覆盖协议

研究网络随机部署情况下的覆盖问题,提出基于Voronoi图的分布式覆盖协议。采用分布式节点冗余判断算法来判断传感器节点自身的冗余性,据此对节点进行相应的职能调度。当网络中节点的通信半径大于或等于其感应半径的2倍时,该协议能达到网络完全覆盖及连通的要求。通过该协议的推广,满足了覆盖度动态变化的要求,保证网络的k-度覆盖。     

Privacy preserving secure expansive aggregation with malicious node identification in linear wireless sensor networks

The Wireless Sensor Networks (WSNs) used for the monitoring applications like pipelines carrying oil, water, and gas; perimeter surveillance; border monitoring; and subway tunnel monitoring form linearWSNs. Here, the infrastructure being monitored inherently forms linearity (straight line through the placement of sensor nodes). Therefore, suchWSNs are called linear WSNs. These applications are security critical because the data being communicated can be used for malicious purposes. The contemporary research of WSNs data security cannot fit in directly to linear WSN as only by capturing few nodes, the adversary can disrupt the entire service of linear WSN. Therefore, we propose a data aggregation scheme that takes care of privacy, confidentiality, and integrity of data. In addition, the scheme is resilient against node capture attack and collusion attacks. There are several schemes detecting the malicious nodes. However, the proposed scheme also provides an identification of malicious nodes with lesser key storage requirements. Moreover, we provide an analysis of communication cost regarding the number of messages being communicated. To the best of our knowledge, the proposed data aggregation scheme is the first lightweight scheme that achieves privacy and verification of data, resistance against node capture and collusion attacks, and malicious node identification in linear WSNs.     

无线传感器网络k点连通可靠性的研究

无线传感器网络的出现引起了人们的广泛关注,由于无线传感器网络的节点不是预先定位而是随机撒放,那么如何保证一定区域内的传感器节点在满足连通可靠性要求的情况下连结成一张网络?而若干次随机抛撒所形成网络的连通度的平均值与网络的节点个数、节点的通讯半径之间又有何关系?通过计算机仿真模拟试验,给出了网络的k(k>0)连通度概率分布曲线;引入了连通度的数学期望概念来描述若干次抛撒所形成网络的连通度k的平均值,给出了其随网络节点个数、节点通讯半径变化的回归方程;给出了无线传感器网络k点连通概率曲线和3点连通的经验公式;分析了边界节点对网络连通度的影响.这些对无线传感器网络节点个数和节点通讯半径的选择、系统冗余设计等都具有重要的指导意义或参考价值.     

基于链接预测的水下WSN消息转发算法

随着移动自组织网络的发展以及为了更加便捷地监测和探索水下环境,水下无线传感器网络开始出现并逐渐受到研究人员的重视.水下无线传感器网络可广泛应用于海洋环境监测、资源开采、水下生物研究、海难搜救等诸多水下场景.与传统的无线传感器网络不同,通常,水下无线传感器网络中存在锚定节点和移动节点两种类型的节点,并且由于水声通信的不规则性和水下环境的复杂性,这些给水下无线传感器网络数据传输带来了很多挑战,如节点移动规律复杂、未来链接不确定等.因此,设计合理的水下无线传感器网络消息转发算法,将有助于提高水下数据的传输效率.针对水下无线传感器网络的网络结构特性,利用链接预测方法来预测未来链接情况,特别引入了时空共同邻居指标来分析节点间链接在时空双重维度上的关联.此外,还针对锚定节点通信范围大、计算能力强的特点,使其扮演边缘计算节点角色,来进一步改善链接预测结果.最后,依据链接预测结果为待转发消息选择合适的下一跳节点.仿真实验结果表明:在消息转发副本数限定的情况下,所提算法能够提高消息投递率,缩短消息转发时延.     

基于OKS的无线传感器网络对偶密钥预分配方案

无线传感器网络(Wireless Sensor Networks WSNs)是由资源有限的传感器节点构成的无线网络。在传感器节点间建立对偶密钥是实现网络安全通信的基础。在本文中,我们提出了一种新的对偶密钥建立方案。本方案以六边形结构进行网络域分簇,利用节点的部署信息和重叠密钥共享(overlap key sharingOKS)思想给每个传感器节点预分配密钥信息。通过分析,本方案具有较高的抗节点俘获能力,能够有效减少存储开销,并提供灵活的安全等级。     

无线传感网身份认证协议研究

无线传感器网络由功耗、处理能力、通信能力及存储容量均有限的节点组成,传感器节点易遭受物理攻击及资源的有限的特点,均为节点安全性带来了严重威胁.因此,文章指出针对无线传感网安全问题,除了要有轻量级的密码算法之外,还需要高效的密钥分配和管理机制.为了解决内存有限性和安全性之间的平衡问题,目前已经有许多密钥建立技术,但是,学术领域中对于哪种方案最有效仍有争议.文章对各种常见的身份认证协议进行了比较和分析.     

基于长延时信道的水下传感器网络中继选择及功率分配优化算法

针对水下传感器网络(UWSN)中水声信道衰落特性随时间-空间-频率随机变化的特点,在此提出利用中继协作网络获得分集增益从而提高水下网络通信质量的水下协作网络模型。基于该协作模型,提出了一种基于信道增益和信号延时双指标最佳中继评价标准,并提出了基于该标准的最佳中继选择算法与基于最小误比特率准则的功率分配算法。仿真结果表明,相比于传统最佳中继选择算法,传输延时降低约16.7%;相对于等功率分配,该算法在典型场景下使误比特率降低1.81dB。     

无线传感器网络中基于Voronoi图的覆盖和连通综合配置协议

着重研究无线传感器网络随机部署下的覆盖和连通问题的解决方案,尤其是当无线传感器节点的通信半径Rc与感应半径Rs之比小于2时的解决方案.本文提出了无线传感器网络中一个基于Voronoi图的覆盖和连通的综合配置协议(VIP).该协议采用了一种分布式节点冗余判断算法以判断无线传感器网络中节点的冗余性,并让节点据此来对自身进行相应的职能调度.该协议能够在Rc/Rs为任意值时保证网络的覆盖和连通性能.本文还将该协议进行了推广,使得该协议能够满足覆盖度和连通度动态变化的要求,保证网络的k-度覆盖和k-度连通.     

基于簇首轮替的高密度无线网状传感器网络中能耗均衡休眠调度方案

将无线传感器网络和无线网状网络相结合构建了无线网状传感器网络拓扑结构,将部分传感器设为休眠状态可以降低高密度无线网状传感器网络中的能量消耗,并且均衡网络能耗可以解决能量空洞问题。提出了一种基于簇首轮替的无线网状传感器网络能耗均衡的休眠调度方案。通过建立簇首轮替的能耗模型,得到在不同传感器轮流担当簇首的条件下网络能耗均衡时传感器的休眠概率。分析和仿真结果表明,相比较随机调度方案,该方案保证了网络覆盖范围,延长了网络生存时间,均衡了网络的能耗。     

WSN的对偶密钥路径本地搜索算法

无线传感器网络中基于规则网络的密钥预置方案具有预置开销小、寻径快等特点,但这类方案直接对偶密钥建立的概率较低。该文基于已经存在的节点连通集团,针对传感器网络对偶密钥连通图,提出层次连通框架,定义节点层次连通度,给出节点本地搜索算法。仿真结果表明该算法能提高节点的平均密钥连通度。     

A survey on routing techniques in underwater wireless sensor networks

Underwater Wireless Sensor Networks (UWSNs) are finding different applications for offshore exploration and ocean monitoring. In most of these applications, the network consists of significant number of sensor nodes deployed at different depths throughout the area of interest. The sensor nodes located at the sea bed cannot communicate directly with the nodes near the surface level; they require multi-hop communication assisted by appropriate routing scheme. However, this appropriateness depends not only on network resources and application requirements but also on environmental constraints. All these factors provide a platform where a resource-aware routing strategy plays a vital role to fulfill the different application requirements with dynamic environmental conditions. Realizing the fact, significant attention has been given to construct a reliable scheme, and many routing protocols have been proposed in order to provide an efficient route discovery between the sources and the sink. In this paper, we present a review and comparison of different algorithms, proposed recently in order to fulfill this requirement. The main purpose of this study is to address the issues like data forwarding, deployment and localization in UWSNs under different conditions. Later on, all of these are classified into different groups according to their characteristics and functionalities.     

传感器网络安全研究综述

新的无线传感器网络正在兴起。结点环境、无线通信方式、结点有限的资源使得其安全问题尤其突出。本文对无线传感器网络的安全问题及其解决方案作分类和综述。首先从多个维度对WSN安全攻击进行分类,并总结不同协议层次的攻击方法;然后讨论目前的解决方案并分类归纳密钥分配算法,重点分析随机密钥分配算法;提出一种新的研究思路。     

混合密钥管理的传感器网络聚类算法设计实现

密钥管理是解决传感器网络安全的关键技术。现有的密钥管理机制,不能很好地优化系统的整体性能,基于连通支配集对传感器网络进行聚类,在簇内实现集中式密钥管理,簇间通过通信主干实现分布式密钥管理,从而构建安全的传感器网络。实验表明,通过混合式的密钥管理,可以有效延长网络生命期。     

基于身份密码学的异构传感网络密钥管理方案

在充分考虑异构无线传感器网络自身特点的基础上,针对现有无线传感器网络密钥管理中存在的问题,利用基于身份的加密算法(Identity-Based Cryptography,IBC),提出了一种异构无线传感器网络密钥管理方案(KMUIBC),并从该方案的安全性、连通性、可扩展性、有效性等方面进行分析,与现有的一些典型方案进行了分析比较,结果表明,KMUIBC有较好的性能。     

无线传感器网络密钥分布方案研究

无线传感器网络广泛应用于目标跟踪、环境监测、军事感应和地震活动测试等方面。网络安全是无线传感器网络应用的关键因素。在无线传感器网络安全结构中,节点的密钥分布是其中的重要一环。资源有限的大规模无线传感器网络的部署需要高效的节点密钥分布机制。高效的节点密钥分布方案能加强网络连通性、提高抵抗节点捕获攻击的能力、减小节点能量的消耗以及扩展节点通信范围。本文分析了密钥分布的安全要求,着重从密钥的产生、密钥连接的建立和性能方面描述了当前典型的密钥分布方案,并比较和分析了这些算法的特点和安全性能。最后结合该领域当前研究现状,指出无线传感器网络密钥分布未来可能的研究方向。     

基于部署信息的无线传感器网络配对密钥方案

在充分考虑无线传感器网络自身特点的基础上,针对现有无线传感器网络密钥管理中存在的问题,利用Blom矩阵,提出了一个基于部署信息的无线传感器网络密钥管理方案(KPSBM),并从该方案的安全性、连通性、可扩展性、有效性等方面进行分析,并与现有的一些常用方案进行了分析比较,结果表明,KPSBM在这些方面有较好的性能。     

基于部署信息的无线传感器网络密钥管理方案

在充分考虑无线传感器网络自身特点的基础上,针对现有无线传感器网络密钥管理中存在的问题,利用基于身份的加密算法,提出一个基于部署信息的无线传感器网络密钥管理方案（KMSBDK）。从该方案的安全性、连通性、可扩展性、有效性等方面进行分析,并与现有一些典型方案进行比较。结果表明,KMSBDK有较好的性能。