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。     

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.     

基于能耗均衡的WSN连通覆盖集构建算法

为提高无线传感器网络的能量利用率,提出一种基于能耗均衡的连通覆盖集构建算法EBACCS。该算法以概率覆盖模型为基础,采用Voronoi图划分目标区域,获得网络冗余节点,根据能量权值函数,从冗余节点中选出必要的连接节点建立一个优化的连通覆盖集。理论分析和仿真实验结果表明,EBACCS能够保证网络的连通性与覆盖性,均衡节点能耗,延长网络寿命。     

机场噪声监测无线传感网络最小连通覆盖集研究

针对机场噪声监测无线传感网络中的最小连通覆盖集问题,设计了一种基于目标区域Voronoi划分的集中式近似算法,用于分析完全覆盖目标区域所需的最低要求的节点集;为了更好地调整噪声监测节点的感知半径Rs与通信半径Rc的比值关系,在通信半径小于两倍感知半径时,提出了一种基于最小生成树的连通算法用以确保CVT算法构造的覆盖集连通所需的辅助节点。理论分析与仿真实验表明,与现有常用的集中式贪婪算法和DVC算法相比,CVT(+MST)算法的性能在时间复杂性和连通覆盖集大小等两方面都较优。     

无线传感器网络的连通性问题研究

无线传感器网络的初始配置最优可以减少传感器网络的拓扑变化和降低网络重置的能量消耗.对初始均匀随机分布的无线传感器网络的连通性进行了研究.运用覆盖理论给出了传感器节点的连通度概率分布模型,并在此模型基础上推导出传感器节点的通信半径与期望连通度概率最大之间的关系.仿真结果表明了结论的正确性.     

无线传感网络中覆盖保持的K-连通子集构造算法

构造无线传感网络中具有连通覆盖特性的节点子集是实现网络休眠调度、延长网络生命周期的关键技术之一,具有重要的研究意义.已有的研究大多侧重于k覆盖节点子集构造问题,由于k覆盖子集在一定条件下便满足k连通,故人们对k连通子集的构造问题研究较少,但通过构造k覆盖节点子集来实现k连通会耗费过多的节点,代价较大.因此,本文提出一个直接构造k连通1覆盖节点子集的算法-CPC,能够用较少的节点构造出一个既能满足网络的覆盖特性又能够满足k-连通特性的节点子集,使得在任意k-1个节点发生故障时,网络能够仍然保持连通.本文还对算法的正确性进行了严格证明,并通过仿真实验与相关算法进行了性能比较.结果表明,与已有的k覆盖算法相比,CPC算法能够节省约55%的节点数.     

群混合智能算法优化异构WSN的生命周期

为了优化异构无线传感器网络的生命周期,找到尽可能多的连通覆盖子集（CCS）,本文建立了以网络覆盖约束、收集约束、连通约束作为目标评价函数的模型。针对该模型,在蚁群算法基础上,引进鱼群拥挤度的概念,解决了蚁群在算法初期陷入局部收敛的问题。实验结果表明,该改进算法比一般蚁群算法具有更好的全局搜索能力和收敛速度,同时针对蚁群算法在构建子集中存在大量冗余节点的问题,提出了关键域法（KFM）判断各子集中冗余节点且利用冗余节点构建新的子集,这不仅能有效提高节点的利用率,而且延长了异构网络的生命周期。     

无线传感器网络的覆盖和连通研究

节点配置是无线传感器网络研究的核心问题之一。为实现传感器节点的配置,随机散布方式被广泛地采用。主要研究了无线传感器网络节点随机配置的完全覆盖和连通问题。通过对网络完全覆盖和连通的分析,给出完全覆盖概率、检测半径和节点数目之间的定量关系;分析了参数对配置的影响,对比高斯分布和均匀分布的配置特性,以指导传感器网络的节点放置。提出了完全覆盖径向连通的配置方案来优化传感器节点数目,从而降低网络的配置代价。最后,利用模拟仿真试验来评定结论。     

自适应半径调整的无线传感器网络覆盖算法

针对随机分布的无线传感器网络中节点分布不均匀造成的覆盖冗余,以及同时存在的覆盖空洞,提出了一种自适应半径调整无线传感器网络覆盖算法,通过阈值判断监测区域内传感器节点密度,根据监测区域内传感器节点疏密程度,利用节点半径步长系数对监测区域内节点半径进行自适应调整,建立无线传感器节点发射功率与节点发射半径的模型,计算无线传感器发射功率,通过实验和仿真,表明上述方法能够保证网络覆盖率的基础上减少无线传感器网络总功耗,提高网络寿命.     

无线传感器网络中一种分布式冗余检测算法

无线传感器网络覆盖控制中现有的大部分冗余检测算法都是针对节点感知半径相同的同构网络的,无法应用于异构网络.提出一种保持网络k级覆盖的适应异构传感器网络的分布式冗余检测算法.该算法根据节点的冗余分布特性设计了有效覆盖邻居选取,通过有效覆盖邻居感知半径关系及交点处的覆盖程度判断检测冗余.仿真表明:算法中有效覆盖邻居选取的设计,大大降低了节点执行冗余计算的时间,算法的运行效率较高;算法在异构WSN中性能优异,冗余检测彻底、充分,有益于节省节点能量,延长网络生存时间.     

基于WSNs的部分覆盖应用的节点唤醒机制

无线传感网络WSNs(Wireless Sensor Networks)已广泛应用于各类领域.然而,由于能量有限,提高传感节点能效是一项挑战工作.休眠调度策略是保存能量、延长网络寿命的有效策略.此外,多数WSNs应用并不要求100％的覆盖.为此,提出面向部分覆盖应用的节点唤醒机制,且标记为PCLA.PCLA机制引用学习自动机去合理地唤醒节点,而其他节点休眠,进而延长网络寿命.首先,唤醒部分节点构成主干网,然后,再利用这些节点的邻居去满足网络覆盖要求.实验数据表明,与同类机制相比,提出的PCLA机制能够有效地满足部分覆盖要求,并且在活动节点数和网络寿命方面也具有较好的性能.     

无线传感器网络中基于异构节点的覆盖控制算法

研究了无线传感器网络中基于异构节点的优化覆盖控制问题.异构无线传感器网络由两类能力不同的节点组成,包括普通节点和超级节点.对普通节点采用基于状态轮转的覆盖控制算法,对超级节点采用基于路由表的转发策略.通过两类节点的协作使得网络达到覆盖与连通的目的.模拟结果表明,在具有相同初始能量的情况下,该算法与SHHN-HS算法相比能够延长网络生命期.     

C3: an energy-efficient protocol for coverage,connectivity and communication in WSNs

The lower layer of ubiquitous and pervasive systems consists of wireless ad hoc and sensor networks. In wireless sensor networks (WSNs), sensors consume most of their energy in data transmission and idle listening. Hence, efficient usage of energy can be ensured by improved protocols for topology control (i.e., coverage and connectivity), sleep scheduling, communication, and aggregation and compression of data. Though several protocols have been proposed for this purpose, they are not energy-efficient. We propose an integrated and energy-efficient protocol for Coverage, Connectivity, and Communication (C3) in WSNs. The C3 protocol uses received signal strength indicator to divide the network into virtual rings, defines clusters with clusterheads more probably at alternating rings, defines dings that are rings inside a cluster and uses triangular tessellation to identify redundant nodes, and communicates data to sink through clusterheads and gateways. The proposed protocol strives for near-optimal deployment, load balancing, and energy-efficient communication. Simulation results show that the C3 protocol ensures partial coverage of more than 90 % of the total deployment area, ensures one connected network, and facilitates energy-efficient communication while expending only one-fourth of the energy compared to other related protocols such as the coverage and connectivity protocol, and the layered diffusion-based coverage control.     

HACH: Heuristic Algorithm for Clustering Hierarchy protocol in wireless sensor networks

Wireless sensor networks (WSNs) require energy management protocols to efficiently use the energy supply constraints of battery-powered sensors to prolong its network lifetime. This paper proposes a novel Heuristic Algorithm for Clustering Hierarchy (HACH), which sequentially performs selection of inactive nodes and cluster head nodes at every round. Inactive node selection employs a stochastic sleep scheduling mechanism to determine the selection of nodes that can be put into sleep mode without adversely affecting network coverage. Also, the clustering algorithm uses a novel heuristic crossover operator to combine two different solutions to achieve an improved solution that enhances the distribution of cluster head nodes and coordinates energy consumption in WSNs. The proposed algorithm is evaluated via simulation experiments and compared with some existing algorithms. Our protocol shows improved performance in terms of extended lifetime and maintains favourable performances even under different energy heterogeneity settings.     

一种无线传感器网络节点随机部署策略

针对无线传感器网络节点随机部署的盲目性,提出一种按随机均匀分布规律部署无线传感器网络节点的策略。证明在感知区域内,随机均匀部署的大量相互独立的传感器节点数目服从泊松分布,通过建立无线传感器网络节点分布模型,得到面积覆盖率与目标区域节点分布密度之间的关系,设计在目标区域内传感器节点数量的估计方法。实验结果表明,该策略能保证无线传感器网络的覆盖性和连通性,更有效地控制网络成本。     

无线传感器网络节点部署问题研究

节点部署是无线传感器网络(W SNs)研究的一个基本问题。合理的节点部署方式有助于提高网络工作效率,优化利用网络资源。针对与节点部署相关的覆盖、连通、能耗三方面基本问题,对现有主要研究成果进行了分类和比较,讨论了三者之间的关系,总结性地提出并分析了网络覆盖和连通性能的评价标准。     

A novel gossip-based sensing coverage algorithm for dense wireless sensor networks

Wireless sensor networks (WSNs) have been widely studied and usefully employed in many applications such as monitoring environments and embedded systems. WSNs consist of many nodes spread randomly over a wide area; therefore, the sensing regions of different nodes may overlap partially. This is called the “sensing coverage problem”. In this paper, we define a maximum sensing coverage region (MSCR) problem and present a novel gossip-based sensing-coverage-aware algorithm to solve the problem. In the algorithm, sensor nodes gossip with their neighbors about their sensing coverage region. In this way, nodes decide locally to forward packets (as an active node) or to disregard packets (as a sleeping or redundant node). Being sensing-coverage-aware, the redundant node can cut back on its activities whenever its sensing region is k-covered by enough neighbors. With the distributed and low-overhead traffic benefits of gossip, we spread energy consumption to different sensor nodes, achieve maximum sensing coverage with minimal energy consumption in each individual sensor node, and prolong the whole network lifetime. We apply our algorithm to improve LEACH, a clustering routing protocol for WSNs, and develop a simulation to evaluate the performance of the algorithm.     

A survey on coverage and connectivity issues in wireless sensor networks

A wireless sensor network (WSN) is composed of a group of small power-constrained nodes with functions of sensing and communication, which can be scattered over a vast region for the purpose of detecting or monitoring some special events. The first challenge encountered in WSNs is how to cover a monitoring region perfectly. Coverage and connectivity are two of the most fundamental issues in WSNs, which have a great impact on the performance of WSNs. Optimized deployment strategy, sleep scheduling mechanism, and coverage radius cannot only reduce cost, but also extend the network lifetime. In this paper, we classify the coverage problem from different angles, describe the evaluation metrics of coverage control algorithms, analyze the relationship between coverage and connectivity, compare typical simulation tools, and discuss research challenges and existing problems in this area.     

基于连通性的无线传感器网络覆盖优化算法

针对无线传感器网络(WSNs)的覆盖优化和连通性问题,提出了一种基于连通性的WSNs覆盖优化算法(CC-BCBS).在二维监测区域内,CC-BCBS以传感器节点间的通信半径作为限制条件,只对连通的传感器节点进行Voronoi图划分,根据节点对应泰森多边形的覆盖情况构造盲区图,将盲区重心作为候选优化位置,使节点尽可能最大化覆盖监测区域.节点通信半径影响着区域覆盖的冗余度,故针对划分时可能出现的3种不同连通情况,给出了相应措施.仿真结果表明:CC-BCBS在覆盖率,分布均匀性,平均连通个数与连通率方面相比BCBS等算法有明显优势.