一个无线传感器网络的网络分割模型

首先指出网络分割会影响网络连通性，并进而影响网络的通信效率；接着从物理层和MAC协议入手，讨论了导致无线传感器网络网络分割问题的通信因素。为了定量地刻画网络分割，定义了网络分割比，并分析了影响网络分割比的物理及几何因素。通过试验采集的大量数据及曲线族拟合法，建立了一个无线传感器网络的网络分割模型，定量地确定了网络节点数、面积比与网络分割比的数学关系。     

无线传感器网络连通k覆盖问题及其解决方案综述

覆盖控制是无线传感器网络的一个基本问题,通过对网络空间资源的优化分配,来更好地完成环境感知和有效传输等任务。作为覆盖控制理论的研究热点之一,连通k覆盖问题研究如何从随机部署的大量传感器节点中选择一部分节点激活,使得任意监测目标都被至少k个不同的活跃节点同时覆盖,而且所有活跃节点都是通信连通的。本文分析了无线传感器网络中连通k覆盖问题的系统模型和算法评价指标,介绍了一些典型的近似算法并对其进行了分析和比较,最后进行了总结和展望。     

无线传感器网络抗毁性

无线传感器网络常因能量耗尽、硬件故障或者遭遇入侵等原因导致节点失效,使得原本连通的网络拓扑分割,甚至导致全局网络受损.因此,研究抗毁性对解决无线传感器网络规模化应用瓶颈具有重要的理论价值.目前有关无线传感器网络抗毁性的研究主要关注以下3个方面:(1)造成无线传感器网络节点失效与网络受损的原因有哪些;(2)如何准确度量无线传感器网络抗毁性;(3)如何有效提升无线传感器网络抗毁性能.文中有针对性地分别从失效成因、测度、提升策略与故障检测和修复等4个方面对有关研究进行归纳和分类,重点分析无线传感器网络抗毁性优化方法,包括路由控制、网络重构和拓扑演化.最后,指出无线传感器网络抗毁性研究未来发展所面临的技术挑战,并就其发展趋势进行探讨.     

无线传感器网络连通忌覆盖问题及其解决方案综述

覆盖控制是无线传感器网络的一个基本问题,通过对网络空间资源的优化分配,来更好地完成环境感知和有效传输等任务。作为覆盖控制理论的研究热点之一,连通k覆盖问题研究如何从随机部署的大量传感器节点中选择一部分节点激活,使得任意监测目标都被至少k个不同的活跃节点同时覆盖,而且所有活跃节点都是通信连通的。本文分析了无线传感器网络中连通k覆盖问题的系统模型和算法评价指标,介绍了一些典型的近似算法并对其进行了分析和比较,最后进行了总结和展望。     

无线传感器网络节点定位算法的研究

无线传感器网络节点数量大、资源有限,采用全球定位系统(GPS)定位设备来获取节点位置信息成本太高,研究适合无线传感器网络节点定位算法具有重要意义。通过分析无线传感器网络节点定位算法的基本原理,介绍已提出的几种节点定位算法,并进行分析比较。     

一种无线传感器网络自适应休眠算法的研究

降低无线传感器网络的能耗一直是迫切解决的问题。通过对无线传感器网络节点能耗分布情况的研究,发现对无线传感器网络节点休眠,可以减少节点收发能耗。针对降低无线传感器网络节点能耗的问题,文中基于多因素、多层次的层次分析法,设计了一种无线传感器网络自适应休眠算法(AHP休眠算法)。实验表明该算法依据信息采集需求和节点剩余能量自适应控制网络节点的休眠和收发,与传统的RS休眠和定时休眠算法对比,提高了节点能量的利用率,延长网络生命期。     

可存盲区的井下无线传感器网络节点部署研究

在分析现有无线传感器网络节点部署方案和覆盖模型的基础上,针对完全覆盖存在难度大、成本高、节点存在冗余等缺点,提出了一种可存盲区的井下无线传感器网络覆盖模型和节点部署方案,并给出了该方案在井下的具体应用。可存盲区的井下无线传感器网络节点部署方案可根据监测对象的具体情况调节盲区度,从而实现盲区大小的设置。分析结果表明,对于相同的节点数量,该方案比完全覆盖时的覆盖面积大;对于同等面积的监测区域,该方案比完全覆盖时所需的传感器节点数量少,不仅节约了系统成本,还在一定程度上改善了节点冗余度问题。     

无线传感器网络一维区域的覆盖研究*

无线传感器网络覆盖问题的研究应综合考虑感知覆盖、通信覆盖和连通覆盖三个方面,建立适合不同监测空间的节点覆盖模型。讨论了无线传感器网络一维区域的覆盖问题,对无线传感器网络中一维直线区域出现的问题进行分析,讨论了均匀分布情况下的节点覆盖概率和覆盖数的计算方法,仿真实验表明节点感知半径是影响节点覆盖率和覆盖数的主要因素。     

带无线能量补充设备的无线传感器网络基站部署策略

为延长无线传感器网络(WSN)生存周期,引入无线能量补充设备,设计一种WSN基站部署策略。通过聚类传感器节点并计算每个区域传感器节点的通信量确定基站位置坐标,构建以最大化能量补充设备驻站时间比为目标的跨层优化问题,并将其转化为具有等优性的线性规划问题,实现传感器节点和无线能量补充设备的最佳配置。仿真结果表明,与固定基站部署策略相比,该基站部署策略可使无线能量补充设备的驻站时间比提升约75%。     

基于鸡群优化的无线传感器网络三面定位算法

针对无线传感器网络空间定位问题进行了研究,为了提高未知节点的定位精度,提出一种基于鸡群优化的无线传感器网络三面定位算法。该算法结合了两种未知节点的求解方法,首先利用三面定位模型,通过求取三个面的交点来获取未知节点的坐标;再使用鸡群优化算法进行改进,根据三面定位法计算出的坐标值以及离未知节点最近信标节点的坐标进行初始化,迭代寻优。使用MATLAB进行仿真,改变算法的迭代次数、信标节点占比和通信距离,来对定位精度进行分析。结果表明该定位算法具有较高的定位精度与较快的收敛速度,且陷入局部最优的可能性低于粒子群定位算法。     

An enhanced real-time routing protocol with load distribution for mobile wireless sensor networks

Mobile wireless sensor network (MWSN) is a wireless ad hoc network that consists of a very large number of tiny sensor nodes communicating with each other in which sensor nodes are either equipped with motors for active mobility or attached to mobile objects for passive mobility. A real-time routing protocol for MWSN is an exciting area of research because messages in the network are delivered according to their end-to-end deadlines (packet lifetime) while sensor nodes are mobile. This paper proposes an enhanced real-time with load distribution (ERTLD) routing protocol for MWSN which is based on our previous routing protocol RTLD. ERTLD utilized corona mechanism and optimal forwarding metrics to forward the data packet in MWSN. It computes the optimal forwarding node based on RSSI, remaining battery level of sensor nodes and packet delay over one-hop. ERTLD ensures high packet delivery ratio and experiences minimum end-to-end delay in WSN and MWSN compared to baseline routing protocol. In this paper we consider a highly dynamic wireless sensor network system in which the sensor nodes and the base station (sink) are mobile. ERTLD has been successfully studied and verified through simulation experiment.     

Secure data aggregation in wireless sensor networks: A comprehensive overview

Wireless sensor networks often consists of a large number of low-cost sensor nodes that have strictly limited sensing, computation, and communication capabilities. Due to resource restricted sensor nodes, it is important to minimize the amount of data transmission so that the average sensor lifetime and the overall bandwidth utilization are improved. Data aggregation is the process of summarizing and combining sensor data in order to reduce the amount of data transmission in the network. As wireless sensor networks are usually deployed in remote and hostile environments to transmit sensitive information, sensor nodes are prone to node compromise attacks and security issues such as data confidentiality and integrity are extremely important. Hence, wireless sensor network protocols, e.g., data aggregation protocol, must be designed with security in mind. This paper investigates the relationship between security and data aggregation process in wireless sensor networks. A taxonomy of secure data aggregation protocols is given by surveying the current “state-of-the-art” work in this area. In addition, based on the existing research, the open research areas and future research directions in secure data aggregation concept are provided.     

无线传感器网络测试技术与测试平台研究

随着无线传感器网络应用研究的不断深入，通过实际传感器节点建立网络平台进行网络测试越来越受到人们的重视。本文对无线传感器网络测试技术和测试平台进行了探讨，并分别对搭建测试平台中的三个关键问题：量化评估节点度网络的状态信息、监视控制节点网络行为、反映大规模网络应用环境，以度解决这三个问题的技术方案进行了介绍和讨论。为无线传感器网络平台的实际设计工作提供了指导和借鉴。     

无线传感器网络数据库的研究

本文根据应用需要，讨论了构建无线传感器网络数据库的必要性，分析了它与传统数据库管理系统在功能上的差别，以及在实现上面临的问题；详细分析了系统的体系结构，主要包括数据库前端和网络节点上的功能组成，以及节点之间协同完成查询请求的关键技术。     

空间传感器节点定位方法研究

无线传感器网络能够实时监测、感知和采集各种环境和检测对象的信息,但无线传感器节点在使用的过程中需要对其进行维护,而在投放传感器节点时,往往没有记录传感器节点的投放空间坐标或者由于其他因素导致传感器节点在投放后位置发生了改变,在这样的情况下,就需要对传感器节点进行定位。介绍一种传感器空间节点定位的方法,并对其误差及改进方法进行了讨论。     

虚拟MIMO无线传感器网络的传输模式

无线传感器网络(wirelesssensor networks,WSN)是由大量低成本、低功耗、具备感知能力、计算能力和无线通信能力的微型传感器节点通过自组织方式构成的网络。多入多出(Multiple-Input Multiple-Output,MIMO)技术是指在发送端和接收端采用多天线,MIMO技术可在不增加频谱资源和天线发送功率的情况下,成倍地提高信道容量,是新一代移动通信系统采用的关键技术。将虚拟MIMO技术引入无线传感器网络,可以利用MIMO技术带来的分集增益,增加接收端信号的信号强度,通过分集来克服信道衰落的影响;也可以利用MIMO技术提供的复用增益,提高信息速率,大大改善网络的能耗特性。本文介绍了虚拟MIMO技术在无线传感器网络中的应用,针对中小规模传感器网络,设计了一种基于分簇的能量高效协作式虚拟MIMO传输模式。并对虚拟MIMO无线传感器网络的能效性进行了分析,最后总结了研究的关键问题以及未来的发展趋势和研究方向。     

LAD: Localization anomaly detection for wireless sensor networks

In wireless sensor networks (WSNs), sensors’ locations play a critical role in many applications. Having a GPS receiver on every sensor node is costly. In the past, a number of location discovery (localization) schemes have been proposed. Most of these schemes share a common feature: they use some special nodes, called beacon nodes, which are assumed to know their own locations (e.g., through GPS receivers or manual configuration). Other sensors discover their locations based on the reference information provided by these beacon nodes. Most of the beacon-based localization schemes assume a benign environment, where all beacon nodes are supposed to provide correct reference information. However, when the sensor networks are deployed in a hostile environment, where beacon nodes can be compromised, such an assumption does not hold anymore. In this paper, we propose a general scheme to detect localization anomalies that are caused by adversaries. Our scheme is independent from the localization schemes. We formulate the problem as an anomaly intrusion detection problem, and we propose a number of ways to detect localization anomalies. We have conducted simulations to evaluate the performance of our scheme, including the false positive rates, the detection rates, and the resilience to node compromises.     

随机部署的无线传感器网络的负载平衡

从结构的角度来研究在大规模随机部署时所形成的无线传感器网络的数据流负载平衡。通过统计分析邻居节点数目来分析其对无线传感器网络的数据流负载平衡的影响,发现在大规模随机部署时节点的邻居节点数目近似服从正态分布,其成因在于边缘效应。仿真实验发现节点通信半径的增大比部署密度的增大更不利于负载平衡。     

Fuzzy topology discovery protocol for SDN-based wireless sensor networks

The growing trend in pervasive systems forces traditional wireless sensor networks to deal with new challenges, such as dynamic application requirements and heterogeneous networks. One of the latest paradigms in this area is software defined wireless sensor network. According to the paradigm, the networks take care of managing topological information and forwarding decisions using a bipartite architecture in which a control plane decides the forwarding policies and the data plane (i.e. ordinary sensor nodes) executes them. Unfortunately, in highly dynamic networks, this approach generates an overhead of control packet exchange between the ordinary nodes and the control plane, that leads to additional energy consumptions. This paper proposes a fuzzy logic based solution, called Fuzzy Topology Discovery Protocol (FTDP), to improve the efficiency of software defined wireless sensor networks. This work is designed according to the Software Defined Networking solution for WIreless SEnsor networks (SDN-WISE), which is an open source solution for software defined wireless sensor networks. The proposed work is one of the first attempts to use fuzzy theory in software defined based wireless sensor networks. The simulation results show that our approach can increase the lifetime of the network by 45% and decreases the packet loss ratio by 50% compared to the basic SDN-WISE solution.