基于Voronoi图的无线传感器网络的节点调度机制

无线传感器网络由大量低能量、短寿命、不可靠的传感器节点组成,最小化能量消耗—延长网络寿命是一个主要的目标。对于大多数传感器应用,通过关掉网络中配置的冗余节点提供对目标区域的完全感知并降低能量消耗是一种有效的方法。据此提出了一种基于Voronoi图的节点调度算法,该算法能在保证网络覆盖范围的情况下,有效地剔除冗余节点,由此延长网络寿命。     

基于传感器网络的航标遥控遥测节能研究

本文提出了基于无线传感器网络的航标遥控遥测系统的节能问题进行了研究。提出了低功耗太阳能电池自动跟踪系统、节能的路由算法（如LEACH算法）、系统进行体眠-唤醒方案调度等节能方法。实际应用系统的测试数据分析证明使用本文提出的节能方法后的系统．系统的功耗有明显下降，有效延长无线传感器网络节点寿命。     

传感器网络结点OS内存管理的设计与实现

传感器网络的结点是基于嵌入式设备的计算机系统，该系统对功能、可靠性、成本、体积、功耗有严格要求，系统中的每个任务、设备以及网络的连接都要求有足够的存储空间，因此选择适合的内存管理算法，高效地利用存储空间，是提高系统性能的一个重要方面。该文以自主开发的传感器结点操作系统SNNEOS为背景，重点讨论了传感器网络结点操作系统内存管理的分配算法与回收算法，为传感器结点的内存管理提供了一个有效的解决方案。     

面向差异化覆盖的异构有向传感器节点调度算法

为延长异构有向传感器网络的寿命，提出一种基于改进珊瑚礁优化算法（ECRO）的面向不同监测目标有不同监测要求的节点调度算法。利用ECRO将传感器集合划分成符合覆盖要求的多个集合，通过集合间的调度达到延长网络寿命的目的。对珊瑚礁优化算法（CRO）的改进体现在四个方面：一是在珊瑚礁的雌雄同体繁殖过程中融入生物地理学优化算法中的迁移操作，保留原有种群的优秀解；二是在雌雄同体繁殖过程中采用一种带有混沌参数的差分变异因子，增强子代的优化能力；三是通过对最差个体执行随机反向学习，增强种群的多样性；四是通过CRO与模拟退火算法的结合，增强算法的局部搜索能力。对数值基准函数和节点调度进行了大量的仿真实验。在数值测试方面的结果表明，与遗传算法、模拟退火算法、差分进化算法及其改进算法相比，ECRO的优化能力更强；在传感器网络节点调度方面的结果表明，与贪婪算法、基于学习自动机的差分进化（LADE）算法和未改进的CRO相比，ECRO使网络寿命分别提高了53.8%、19.0%和26.6%，验证了所提算法的有效性。     

铁路道口无人监控的WSN应用研究

为减少铁路道口行车事故,基于对火车行进中振动信号的检测,研究了无线传感器网络新技术在道口无人监控系统中的应用。提出了分簇的多跳汇聚树路由算法,用以减少参与网络运行的结点个数,节约全网能量;使用了振动信号数据融合机制,实现数据处理精度的提高。在IRIS结点和MTS400CB传感器板上进行系统设计,利用MIB520网关实现了无线网和有线网之间的桥接。仿真结果表明该系统合理,减少了结点能耗,能够延长系统寿命。     

WSN目标入侵节能检测算法研究

无线传感器网络是能量受限型网络,提高能量效率、延长网络寿命是无线传感器网络设计的重要目标。为了延长设防区域无线传感器网络寿命,并且确保无线传感器网络能够检测到入侵目标,提出利用一种圆环状的辐射扫描波来检测入侵目标。通过理论分析和仿真,结果表明,警戒系统使用辐射扫描算法的网络寿命比周期休眠算法更长。     

基于概率探测模型的传感器结点配置研究

无线传感器网络结点配置是传感器网络研究的核心问题之一,它反映出无线传感器网络的代价和探测能力.主要研究了基于一种更为实用化概率检测模型(引入x%-RS 的概念)的无线传感器网络覆盖优化配置问题.在严格确保无线传感器网络连通性的条件下,优化了传感器结点配置数目并达到要求的覆盖度,获得具体的传感器结点配置方案.为提高算法的效率,在分步优化算法的基础上尝试一次循环配置多个传感器结点.最后,通过模拟计算给出配置算法的性能.     

动态可靠信标结点无线传感器网络定位算法

在无线传感器网络中,距离无关定位技术得到了人们广泛的关注.在有洞的各向异性网络中,为提高普通结点到信标结点之间距离估计的准确性,提出一种距离无关的动态可靠信标结点定位算法.该算法以不同信标结点对之间最短路径上平均单跳距离差异为基础,得到普通结点的直接可靠参考信标结点集和间接可靠参考信标结点集.然后,从可靠参考信标结点集中选择参考结点对普通结点进行定位.仿真结果表明,与以前算法相比,新算法能降低定位误差.     

栅栏覆盖最大化生存周期调度算法

栅栏覆盖是近年来无线传感器网络的研究热点之一,如何延长生存周期是无线传感器网络研究的一个重要问题。针对无线传感器网络的栅栏覆盖应用,设计了两种最大化网络生存周期的调度算法:集中式的Greedy调度算法和分布式的DBCS调度算法。仿真实验表明:两种算法显著地延长了网络的生存周期;在较稀疏的网络中,DBCS算法与Greedy算法性能接近,分布式的DBCS算法适合应用于大规模传感器网络。     

基于时间片的无线传感器网络拓扑控制

LEACH通过分簇算法与功率控制两种拓扑控制方法有效地降低了无线传感器网络的能耗,延长了网络寿命.然而,在具备能量意识的PowerTOSSIM仿真实验中发现,LEACH往往在网络整体能量较多的情形下会出现少量结点过早死亡的现象.提出了基于能量意识的簇头选举方法和簇内基于时间片的动态活动结点(Active Node)负责机制,实现了网内各结点的能量负载均衡,通过大量仿真实验及相关工作的分析与比较,说明该方法有效克服了LEACH因簇规模大小不同而导致的结点能耗不均匀现象,从而延长了网络寿命.     

一种高跟踪质量保证的预先节点选择策略

为保证传感器网络节点高质量的目标跟踪效果,采用在目标移动的方向上提前选择一些节点进行监控的策略,保证当目标移动到新的位置时总有监测节点进行持续的监测,使这些监测节点总是离目标最近,感知质量最高;该策略依据网络能量消耗的不均衡性,在能量有剩余的区域提前唤醒更多的节点,而在能量消耗紧张的区域少唤醒节点,与其他策略相比并没有降低网络寿命。通过实验性能分析对比表明：该策略可以在不降低网络寿命的前提下大幅度提升跟踪质量。     

A two-hop clustered image transmission scheme for maximizing network lifetime in wireless multimedia sensor networks

In traditional wireless sensor networks, normal sensor nodes which measure scalar physical phenomena like temperature, pressure and humidity usually compress the data before sending them out to minimize the communication energy consumption. However, this strategy may not be suitable for image transmission in wireless multimedia sensor networks. In the traditional clustering structure, when the camera-equipped node or the cluster head compresses the images, an energy hole will appear. This is a key factor that affects the lifetime of the network. To avoid the energy hole problem, a two-hop clustered image transmission scheme is proposed in this paper. In the proposed scheme, many redirectors are used to compress and forward the images for the purpose of reducing energy consumption of the camera-equipped node and the cluster head. With adaptive adjustment of the transmission radius in the camera cluster and tasks allocation based on the residual energy of the normal sensor nodes by the camera-equipped node, the energy consumption of the nodes in the network is balanced. The experimental results show that the proposed scheme can prolong the network lifetime dramatically in the case of the sensor nodes deployed densely.     

学习自动机结合节点功率自适应调整的WSN目标覆盖方案

针对大多数现有无线传感器网络(Wireless Sensor Network, WSN)目标覆盖方案没有考虑传感器功率(传感范围)可调的问题,提出一种基于学习自动机(Learning Automata, LA)和节点功率自适应调整的WSN的目标覆盖方案。利用LA算法根据节点能量自适应调整节点的发射功率,构建能够覆盖所有目标的覆盖集,并通过精简过程获得最小覆盖集,从而减低节点的能耗,提高网络的生命周期。通过实验研究了传感器数量和目标数量对网络寿命的影响,并将该方案与基于贪婪算法、遗传算法的方案进行比较,结果表明,该方案能够获得更多的覆盖集和更长的网络寿命。     

异构传感器网络的分布式能量有效成簇算法

为了延长网络的生存时间,需要设计能量有效的协议,以适应传感器网络的特点.成簇算法是传感器网络中减少能量消耗的一种关键技术,它能够增强网络的扩展性和延长网络的生存时间.研究了异构传感器网络中成簇算法在节省能量方面的性能,提出一种适应异构无线传感器网络的分布式能量有效的成簇方案.此方案基于节点剩余能量与网络节点的平均能量的比例来选举簇头节点.较高初始能量和剩余能量的节点比低能量节点拥有更多的机会成为簇头节点,从而使网络能量均匀消耗,延长网络的生存时间.模拟实验结果显示,与现有的重要成簇方案相比,新的成簇算法在异构网络下提供了更长的网络生存时间和更大的网络有效吞吐量.     

DAR: An energy-balanced data-gathering scheme for wireless sensor networks

A wireless sensor network faces special challenges due to its inherent features, such as the limited energy. The energy constraint drives research on how to utilize energy efficiently to prolong the lifetime of the network. Because a sink node takes the responsibility of collecting data from other nodes, a usual conception is to transfer data towards the sink node by multihop. However, conventional data-gathering schemes based on the conception give rise to the hotspot problem because of the nodes that run out of their energy sooner than other nodes, which results in accelerating the end of the whole network. The closer sensor nodes are to the sink, the more quickly they exhaust their energy, which leaves an upper bound to the lifetime of the whole network. Because of the bottleneck nodes, the network loses its service ability regardless of a large amount of residual energy of the other nodes. In this paper, we propose a novel data-gathering scheme, DAR, to handle the hotspot problem, in which all the nodes participate in the workload of gathering data from the whole network and transferring the data directly to the sink. In our scheme, the forwarding behavior of all the nodes is scheduled to balance their burden of aggregating and transmitting the network data and the nodes may send their data back against the sink, which differs from the conventional schemes. We performed simulation experiments to evaluate the performance of the DAR scheme, and the results show that our data-gathering scheme can balance the energy consumption among all the nodes and extend the network lifetime notably.     

An energy-saving routing architecture with a uniform clustering algorithm for wireless body sensor networks

Wireless body sensor networks are expected to extend human-centered applications in large-scale sensing and detecting environments. Energy savings has become one of the most important features of the sensor nodes to prolong their lifetime in such networks. To provide reasonable energy consumption and to improve the network lifetime of wireless body sensor network systems, new and efficient energy-saving schemes must be developed. An energy-saving routing architecture with a uniform clustering algorithm is proposed in this paper to reduce the energy consumption in wireless body sensor networks. We adopted centralized and cluster-based techniques to create a cluster-tree routing structure for the sensor nodes. The main goal of this scheme is to reduce the data transmission distances of the sensor nodes by using the uniform cluster structure concepts. To make an ideal cluster distribution, the distances between the sensor nodes are calculated, and the residual energy of each sensor node is accounted for when selecting the appropriate cluster head nodes. On the basis of the uniform cluster location, the data transmission distances between the sensor nodes can be reduced by employing an adaptive multi-hop approach. The energy consumption is reduced, and the lifetime is extended for the sensor nodes by balancing the network load among the clusters. Simulation results show that the proposed scheme outperforms the previously known schemes in terms of the energy consumption and the network lifetime for the wireless body sensor networks.     

一种支持多分辨率查询的数据存储策略

减少空闲侦听是延长无线传感网络生命周期的有效途径。文章分析了无线传感网络在数据处理和数据传输时的能耗问题,提出了一种支持多分辨率查询的数据存储策略。该策略是将指定区域内所有无线传感节点的工作时槽以一种蛇形排列方式进行分配,使各节点周期性地进入睡眠或侦听状态。在任意时刻,有且仅有两个传感节点处于工作状态,既保证了系统的可靠性,又降低了系统的开销。仿真实验表明,该方法减少了空闲侦听,降低了传感器的能耗,有效延长了网络的生命周期。     

EEMC: An energy-efficient multi-level clustering algorithm for large-scale wireless sensor networks

Wireless sensor networks can be used to collect environmental data from the interested area using multi-hop communication. As sensor networks have limited and non-rechargeable energy resources, energy efficiency is a very important issue in designing the topology, which affects the lifetime of sensor networks greatly. In this paper, the energy consumption is modeled and compared under the flat scheme and the clustering scheme, respectively. Motivated by the analysis, we propose an energy-efficient multi-level clustering algorithm called EEMC, which is designed to achieve minimum energy consumption in sensor networks. The cluster head election scheme is also considered in EEMC. EEMC terminates in O(log log N) iterations given N nodes. When the path loss exponent is 2, EEMC also achieves minimum latency. We focus on the case where sink node is remotely located and sensor nodes are stationary. Simulation results demonstrate that our proposed algorithm is effective in prolonging the network lifetime of a large-scale network, as well as low latency and moderate overhead across the network.     

Energy-aware self-organisation algorithms with heterogeneous connectivity in wireless sensor networks

Heterogeneity of node energy is a common phenomenon in wireless sensor networks. In such node energy heterogeneous sensor network, how to balance the energy consumption is the key problem on extending the lifetime of the sensor network system. An energy-efficient self-organisation algorithm with heterogeneous connectivity based on energy-awareness is proposed. Each sensor node in the network adjusts its own transmission radius based on the local energy information during the constructing and operating phase. Thus heterogeneous network topology, in which the nodes can choose different transmission radius, is formed. In contrast to the homogeneous network model, in which the node carries the same radius, simulation and analysis are conducted to explore the topology characteristics and robustness with different node energy distribution. The degree distribution shows the scale-free property in the heterogeneous model. The proposed network model enjoys higher efficiency of transmitting data, less clustering, higher robustness under node random failures and longer network lifetime than those in the homogeneous ones.     

基于梯度的无线传感器网络能耗分析及能量空洞避免机制

在基于"梯度汇聚"模型的无线传感器网络 (Wireless sensor networks, WSNs)中, 因节点间能量消耗不平衡而引发的能量空洞一直是影响网络生存周期的重要原因. 本文分别分析了无通信干扰的自由空间环境和瑞利衰落环境下网络中节点的能量消耗,提出了一种基于节点能量非均匀分布的能量空洞避免机制,即根据节点的能耗水平为每个节点储备不同的初始能量.并结合通信干扰、休眠机制等因素,研究了基于"梯度汇聚"模型的无线传感器网络生存周期的上界和下界. 模拟结果表明,该机制提高了能量的利用效率,延长了网络的生存周期.