连通支配集算法及其改进

无线传感器网络中通常利用连通支配集以形成虚拟骨干网进行分层次的路由.分析现有的几种去冗余分布式连通支配集构造算法,针对它们冗余度大,计算复杂,提出了一种改进的连通支配集构造算法,利用节点的度以及编号构成的集合取代节点编号作为节点的权值,采用DRN算法的节点覆盖思想,并扩展为当遇到闭合环路的情况下,采用保留闭合环路中权值大的节点去冗余的方法,在保证整个网络连通的情况下减少了连通支配集节点的总数.最后通过Matlab仿真分析,证明了算法的有效性.     

混合传感器网络中基于向量代数的覆盖补偿算法

针对混合传感器网络中,能量耗尽造成的覆盖空洞与休眠冗余节点能量剩余可能并存的矛盾现象,提出一种基于向量代数的移动节点覆盖补偿方法.算法包含所有可能参与补偿的冗余节点对各自位移量的计算方法,空洞边缘节点在平衡节点剩余能量的基础上,对最佳冗余节点的选择启用策略,保证网络能充分利用遗留能量资源的同时实现完全覆盖补偿.实验分析表明,本算法在平均移动距离、能量开销等方面均优于COA算法.     

一种无线传感器网络全连通群的休眠调度算法

该文针对无线传感器网络的覆盖性和连通性问题,在假设传感器节点地理位置信息已知的条件下,设计了一种包含全连通群的建立和维护以及群内节点休眠调度的全新算法。该算法采用保证群内节点彼此一跳可达的全连通群分群方法,以及分布式节能的休眠调度策略,最大程度上减少传感器网络的能量消耗,延长了网络寿命。仿真结果表明:该算法能较好地保证无线传感器网络的覆盖性和连通性,且能耗较低。     

一种基于传感器网络的DRN改进算法

介绍了连通支配集的基本概念,提出了一种改进型分布式连通支配集DRN算法。该算法可在一个节点u的N1（u）不能直接连通、但能通过一个编号比节点u大的节点连通时去除节点u的冗余,因而具有保留编号大的节点的支配集性质,可在不增加支配集节点数和通信开销的基础上,减少支配集节点的尺寸并保证网络的连通性。     

无线传感器网络的中继节点自适应选择休眠机制

针对无线传感器网络节点能量有限的问题,设计一种中继节点自适应休眠方法,对网络节点的工作时间进行优化调度。在路由链路建立中,根据网络中节点的地理位置、剩余能量选择中继节点的方法进行节点休眠调度。网络工作时通过计算下一跳最佳节点位置,选取其附近区域内剩余能量多的节点作为下一跳的转发节点,设计出中继节点自适应选择的节点休眠机制。仿真结果表明,所设计的休眠机制提高了节点能量利用效率、延长了网络工作时间。     

一种无线传感器网络的能耗平衡覆盖模型

针对无线传感器网络节点能量有限、最小覆盖方法能耗不均衡的问题,该文提出了一种能耗平衡的连通覆盖模型,并对模型进行了分析与仿真。模型利用Voronoi划分和Delaunay三角剖分对传感器网络进行分割,判别重复覆盖目标区域的冗余传感器节点,采用节点到sink点的跳数对节点分层,进而提出选择休眠节点的方法。仿真结果表明,由模型建立的非最小连通覆盖集所导出的无线传感器网络,能够平衡节点能耗、使用优化路由、减弱路由关键点的影响。     

无线传感器网络冗余节点休眠调度算法

提出一种冗余节点休眠调度算法来延长网络生命周期。调度过程中重点考虑两方面问题：一是采取策略防止大量节点同时从工作状态转入休眠状态以防止大量盲区同时产生;二是根据邻居表中节点的工作邻居数量,判定节点是否处于网络边界,对边界节点和内部节点采用不同的调度策略,防止边界收缩。仿真结果表明,算法能有效延长无线传感器网络的生命周期。     

基于极大独立集的最小连通支配集的分布式算法

全网范围的广播在无线传感器网络和移动自组织网络中有着广泛的应用.为节省网络资源,减少冗余转发节点成为广播中需解决的关键问题.广播过程中最小化参与转发节点数问题与图论中求解最小连通支配集问题等价,而在任意图中求解最小连通支配集是NP完全问题.本文基于极大独立集,提出了一种求解最小连通支配集的分布式算法(MISB),并证明了算法的正确性.仿真结果表明,使用该算法能得到较小的连通支配集,从而有效减少网络广播过程中的转发节点数,大大节省了网络资源.     

邻近信息约束下的随机异构无线传感器网络节点调度算法

针对高密度部署的随机异构传感器网络内部存在的覆盖冗余问题,该文提出一种随机异构无线传感器网络的节点调度算法(NSSH)。在网络原型拓扑的支撑下构建Delaunary三角剖分,规划出节点进行本地化调度的局部工作子集。通过折中与邻近节点的空外接圆半径,完成对感知半径的独立配置;引入几何线、面概念,利用重叠面积和有效约束圆弧完成对灰、黑色节点的分类识别,使得节点仅依赖本地及邻居信息进行半径调整和冗余休眠。仿真结果表明,NSSH能以低复杂度的代价,近似追平贪婪算法的去冗余性能,并表现出了对网络规模、异构跨度和参数配置的低敏感性。     

基于冗余节点休眠和分阶段唤醒策略的传感器网络三维覆盖控制方法

该文针对无线传感器网络中节点能量有限且密集布点时存在大量冗余节点的情况,提出了基于冗余节点休眠和分阶段唤醒策略的无线传感器网络3维覆盖控制方法。在3维待监测区域中随机配置大量传感器节点,达到高密度分布,使冗余节点处于休眠状态,等待活跃节点能量耗尽之后,分阶段唤醒休眠节点,直至整个传感器网络中所有节点的能量都耗尽为止。仿真结果表明,该方法提高了传感器网络的网络性能,且对相同的传感器节点数,分阶段唤醒策略优于不分阶段的唤醒策略,先使冗余节点休眠之后再唤醒方法的网络性能高于直接唤醒方法的网络性能。     

Prolonging lifetime for wireless rechargeable sensor networks through sleeping and charging scheduling

Prolonging network lifetime is a fundamental requirement in wireless sensor network (WSN). Existing charging scheduling algorithms suffer from high node redundancy and energy consumption issues. In this paper, we study WSN charging problem from the perspectives of energy conservation combined with energy replenishment scheduling. Firstly, we detect the redundant nodes whose energy is wasted in the network functionality and develop a K‐covering redundant nodes sleeping scheduling algorithm (KRSS) for reducing energy. Secondly, we employed multiple wireless charging vehicles (WCVs) for energy replenishment and optimize the charging scheduling algorithm to prevent any exhaustion of nodes, and we proposed a distance and energy–oriented charging scheduling algorithm (DECS) with multiple WCVs. Simulation experiments are conducted to show the advantages of the proposed KRSS+DECS, confirming that our scheme is capable of removing redundant nodes, lowering node failures, and prolonging network lifetime.     

Connectivity maintenance and coverage preservation in wireless sensor networks

In wireless sensor networks, one of the main design challenges is to save severely constrained energy resources and obtain long system lifetime. Low cost of sensors enables us to randomly deploy a large number of sensor nodes. Thus, a potential approach to solve lifetime problem arises. That is to let sensors work alternatively by identifying redundant nodes in high-density networks and assigning them an off-duty operation mode that has lower energy consumption than the normal on-duty mode. In a single wireless sensor network, sensors are performing two operations: sensing and communication. Therefore, there might exist two kinds of redundancy in the network. Most of the previous work addressed only one kind of redundancy: sensing or communication alone. Wang et al. [Intergrated Coverage and Connectivity Configuration in Wireless Sensor Networks, in: Proceedings of the First ACM Conference on Embedded Networked Sensor Systems (SenSys 2003), Los Angeles, November 2003] and Zhang and Hou [Maintaining Sensing Coverage and Connectivity in Large Sensor Networks. Technical report UIUCDCS-R-2003-2351, June 2003] first discussed how to combine consideration of coverage and connectivity maintenance in a single activity scheduling. They provided a sufficient condition for safe scheduling integration in those fully covered networks. However, random node deployment often makes initial sensing holes inside the deployed area inevitable even in an extremely high-density network. Therefore, in this paper, we enhance their work to support general wireless sensor networks by proving another conclusion: “the communication range is twice of the sensing range” is the sufficient condition and the tight lower bound to ensure that complete coverage preservation implies connectivity among active nodes if the original network topology (consisting of all the deployed nodes) is connected. Also, we extend the result to k-degree network connectivity and k-degree coverage preservation.     

Performance evaluation of packet aggregation scheme for VoIP service in wireless multi-hop network

In a wireless multi-hop network environment, energy consumption of mobile nodes is an important factor for the performance evaluation of network life-time. In Voice over IP (VoIP) service, the redundant data size of a VoIP packet such as TCP/IP headers is much larger than the voice data size of a VoIP packet. Such an inefficient structure of VoIP packet causes heavy energy waste in mobile nodes. In order to alleviate the effect of VoIP packet transmission on energy consumption, a packet aggregation algorithm that transmits one large VoIP packet by combining multiple small VoIP packets has been studied. However, when excessively many VoIP packets are combined, it may cause deterioration of the QoS of VoIP service, especially for end-to-end delay. In this paper, we analyze the effect of the packet aggregation algorithm on both VoIP service quality and the energy consumption of mobile nodes in a wireless multi-hop environment. We build the cost function that describes the degree of trade-off between the QoS of VoIP services and the energy consumption of a mobile node. By using this cost function, we get the optimum number of VoIP packets to be combined in the packet aggregation scheme under various wireless channel conditions. We expect this study to contribute to providing guidance on balancing the QoS of VoIP service and energy consumption of a mobile node when the packet aggregation algorithm is applied to VoIP service in a wireless multi-hop networks.     

基于冗余节点的LEACH协议的改进

无线传感器网络中LEACH协议是一种典型的能有效延长网络生命周期的节能通信协议。因为其优秀的节能效果和其简单的规程得到了广泛的认可。但是LEACH簇头算法存在簇头开销大、簇头没有确定的数量和位置等不足。而在成簇后的稳定阶段,节点通过一跳通信将数据传送给簇头,簇头也通过一跳通信将聚合后的数据传送给基站,这样会造成簇头节点...     

AODV能量优化策略

针对传统的AODV路由协议采用扩展环路由搜索算法导致的路由开销较大,没有考虑节点能量的问题,提出一种新的算法。此算法在路由请求过程中能够根据以前搜索中得到的信息,让多余的节点处于静默状态,不参与下一次的路由发现。并且综合考虑节点能量,尽可能地让低能量节点处于静默状态,从而达到均衡节点能量使用的目的。仿真结果表明改进算法有效延长了网络生存时间,提高了包投递率。     

基于准格型策略的无线传感网协作覆盖算法

该文提出了一种基于准格型策略的无线传感网协作覆盖QGCC(Quasi-Grid based Cooperative Coverage)算法,通过在随机分布节点中构造准格型结构并结合协作感测模型,减少活动节点数量,延长覆盖周期。QGCC设计了低复杂度的分布式虚拟网格确定方法及能量高效的节点调度策略,定义了不规则度指标以分析网络的不规则程度对覆盖性能的影响。仿真实验表明,相比于参照算法,QGCC能够较大程度地减少活动节点的数量,大幅延长网络的覆盖周期;此外,该算法的覆盖周期和节点密度具有近似线性的关系,且比参考算法具有更大的斜率,说明其对冗余节点具有更高的利用效率。     

Secure coverage-preserving node scheduling scheme using energy prediction for wireless sensor networks

With the fast development of the micro-electro-mechanical systems(MEMS),wireless sensor networks(WSNs)have been extensively studied.Most of the studies focus on saving energy consumption because of restricted energy supply in WSNs.Cluster-based node scheduling scheme is commonly considered as one of the most energy-efficient approaches.However,it is not always so efficient especially when there exist hot spot and network attacks in WSNs.In this article,a secure coverage-preserved node scheduling scheme for WSNs based on energy prediction is proposed in an uneven deployment environment.The scheme is comprised of an uneven clustering algorithm based on arithmetic progression,a cover set partition algorithm based on trust and a node scheduling algorithm based on energy prediction.Simulation results show that network lifetime of the scheme is 350 rounds longer than that of other scheduling algorithms.Furthermore,the scheme can keep a high network coverage ratio during the network lifetime and achieve the designed objective which makes energy dissipation of most nodes in WSNs balanced.