异构无线传感器网络能量和距离有效分簇算法

降低能耗、延长网络生存时间，是无线传感器网络设计的重要目标。提出了一种基于虚拟区域划分的适用于异构无线传感器网络的能量和距离有效分簇算法。仿真结果证明，此算法可有效地均衡簇内负载，延长网络的稳定周期和生存时间，提高网络的通信效率。     

基于能量效率的无线传感器网络分簇算法

提出了一种最大选票和负载平衡的分簇算法(VLCA)。该算法是完全分布式的,不依赖于网络大小和其拓扑结构。仿真结果显示:该分簇算法能够使簇的数量减少20%到50%,并且能有效延长传感器网络的生命周期。     

无线传感器网络中的能量分布

在线性均匀分布的无线传感器网络中，通过分析网络内各种载荷引起的能量消耗及各类路由算法对网络生命周期的影响，提出了通过改变网络能量分布密度来提高网络生命周期的方法．通过大量实验总结出能量分布的模型，并将该模型扩展到窄带区域内分布的网络．仿真实验结果表明按该密度分布时，网络生命周期将明显增加．     

改进无线传感器网络路由算法

无线传感器网络是由能量有限的节点组成,高效节能的路由算法是无线传感器网络的基础。针对低功耗自适应分簇（LEACH）路由算法在选择簇首节点及通信过程中能量消耗大的不足问题,提出了一种改进的LEACH路由算法。引入节点剩余能量因素参与簇首节点的选择,有效地降低剩余能量较小的节点成为簇首的可能性,节点之间的数据传输采用单跳和多跳相结合的通信方式,也降低了传感器网络能耗。     

无线传感器网络分簇路由协议的对比分析

本文分析了无线传感器网络中基于分簇的路由协议的优点,介绍了几种基于分簇的路由协议,通过分析对比的方式总结了这几种协议在网络性能方面的优缺点。     

无线传感器网络中的能量分布

在线性均匀分布的无线传感器网络中,通过分析网络内各种载荷引起的能量消耗及各类路由算法对网络生命周期的影响,提出了通过改变网络能量分布密度来提高网络生命周期的方法.通过大量实验总结出能量分布的模型,并将该模型扩展到窄带区域内分布的网络.仿真实验结果表明按该密度分布时,网络生命周期将明显增加.     

无线传感器网络LEACH算法的研究

无线传感器网络能够实时监测、采集和处理环境信息,应用前景十分广阔。目前,路由算法已成为无线传感器网络的关键技术之一。LEACH算法是一种典型的分簇路由算法,簇头的选取直接影响到算法性能的优劣。通过对LEACH算法的分析,在簇头节点的选取方面提出了改进方案。     

基于网络编码和占空比的无线传感器网络节能方案

提出一种结合随机网络编码和占空比的无线传感器网络节能方案（RNC_DCES）. 该方案根据所接收数据标识信息决定节点处于工作状态或睡眠状态,以避免数据重复接收,并通过结合随机网络编码,增加相同传输次数下的数据信息量,从而实现节能. 通过理论计算分析了RNC_DCES方案所构建传输模型下的网络能耗最大值,并验证了多跳网络能耗的最优解. 实验结果表明,对比联合随机占空比网络编码（RDCNCode）算法和改进型自适应网络编码（AdapCode++）算法,RNC_DCES延长了网络生命周期4.02%和8.51%,提升了包投递率14.83%和4.65%,从而有效提升了数据包投递率和网络能量效率.     

改进的基于分簇无线传感器网络的数据聚合算法

为了有效地延长分簇无线传感器网络的寿命,提出了一种改进的解决不均衡能量消耗问题的新算法EESA(Energy-efficient separating algorithm)。在考虑簇间能耗平衡的基础上,根据网络拓扑和能量消耗来计算簇半径,对基本的簇划分方式进行了改进,并通过将单个簇头的任务分配给两个节点完成以实现簇内的能耗平衡的方法从任务分离角度对簇头选举策略进行了改进。仿真结果表明:EESA可以有效避免能量洞问题,并减少整个传感器网络的能量消耗,从而延长了网络寿命。     

Novel routing protocol for heterogeneous wireless sensor networks

An improved LEACH for heterogeneous wireless sensor networks is proposed.Nodes are distributed in a sensing area that is divided into a number of same equilateral hexagons.Heterogeneous nodes act as the cluster heads and ordinary nodes act as those cluster sensors in all clusters.The structure of WSNs is a two-layer structure.The upper layer consists of all cluster heads and the lower layer consists of all ordinary sensors managed by their corresponding cluster heads.The cluster heads and the ordinary sensors establish their pairwise keys respectively through utilizing different methods.The arithmetic balances energy expense among all kinds of nodes,saves the node energy,and prolongs the life of wireless sensor networks.Additionally,Analysis demonstrates that the security of wireless sensor networks has been improved obviously even with some heterogeneous nodes.     

无线异构网络中终端的能耗分析模型

为了对无线异构网络中多模终端的能耗分析问题进行研究,通过考察终端的工作机理,利用半马尔科夫链描述终端的通信状态,从而得到终端的能耗分析方程. 相比已有的工作,提出的模型更全面地考虑了终端的工作状态,还考虑了终端发现wireless local area network(WLAN)的概率和业务类别等因素的影响. 分析结果表明,终端能耗随呼叫到达强度和呼叫持续时间增大而增大;终端能耗与话音业务的比例和发现WLAN的概率均成近似线性关系;使WLAN模块进入低能耗的等待状态并不会节省终端能耗.     

A sink moving scheme based on local residual energy of nodes in wireless sensor networks

In the application of periodic data-gathering in sensor networks, sensor nodes located near the sink have to forward the data received from all other nodes to the sink, which depletes their energy very quickly. A moving scheme for the sink based on local residual energy was proposed. In the scheme, the sink periodically moves to a new location with the highest stay-value defined by the average residual energy and the number of neighbors. The scheme can balance energy consumption and prevent nodes around sink from draining their energy very quickly in the networks. The simulation results show that the scheme can prolong the network lifetime by 26%–65% compared with the earlier schemes where the sink is static or moves randomly. Foundation item: Project(60673164) supported by the National Natural Science Foundation of China; Project(20060533057) supported by the Specialized Research Foundation for the Doctoral Program of Higher Education of China     

Coordinated node scheduling for energy-conserving in large wireless sensor networks

Aiming at developing a node scheduling protocol for sensor networks with fewer active nodes, we propose a coordinated node scheduling protocol based on the presentation of a solution and its optimization to determine whether a node is redundant. The proposed protocol can reduce the number of working nodes by turning off as many redundant nodes as possible without degrading the coverage and connectivity. The simulation result shows that our protocol outperforms the peer with respect to the working node number and dynamic coverage percentage.     

Prediction-based energy-efficient target tracking protocol in wireless sensor networks

A prediction based energy-efficient target tracking protocol in wireless sensor networks (PET) was proposed for tracking a mobile target in terms of sensing and communication energy consumption. In order to maximize the lifetime of a wireless sensor network (WSN), the volume of messages and the time for neighbor discovery operations were minimized. The target was followed in a special region known as a face obtained by planarization technique in face-aware routing. An election process was conducted to choose a minimal number of appropriate sensors that are the nearest to the target and a wakeup strategy was proposed to wakeup the appropriate sensors in advance to track the target. In addition, a tracking algorithm to track a target step by step was introduced. Performance analysis and simulation results show that the proposed protocol efficiently tracks a target in WSNs and outperforms some existing protocols of target tracking with energy saving under certain ideal situations.     

应用于无线传感器网络的自适应TDMA协议

提出了一种应用于无线传感器网络的自适应、低功耗的时分多址接入协议AT-MAC.该协议根据应用和拓扑的变化来自适应地伸缩时帧长度,提高了信道的利用率;采用二叉树结构来方便地管理时隙分配信息;基于两跳邻域信息为节点分配时隙,减少了申请冲突.时帧长度的可变和对邻域信息的获知使得AT-MAC具有良好的扩展性和适应能力.AT-MAC还采用节能模式来减少节点的能量消耗.仿真结果表明,AT-MAC可以有效地提高信道的利用率,缩短传输时延,并减少能量的消耗.     

延长无线传感器网络生存周期的跨层算法

为了延长无线传感器网络(WSNs)的生存周期,提出了联合优化物理层和网络层的跨层算法.首先通过物理层的功率控制方法,初步确定可能参与通信传输的传感器节点候选集;然后在节点候选集中,综合考虑传感器节点的接入概率、端到端通信链路的单跳成功传输概率和端到端通信链路的能量效率,以达到均衡性地进行网络层路由选择的目的,实现传感器网络的端到端通信传输过程.仿真结果表明,在保证能量效率的同时,该算法可以有效地延长无线传感器网络的生存周期.