【作者】 房晓菲；

【导师】 沈永增；

【作者基本信息】 浙江工业大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 无线传感器网络(Wireless Sensor Network,WSN)就是由大量部署在监测区域内的传感器节点组成,通过无线通信的方式形成的一个多跳的自组织的网络系统,从而协作地感知、采集和处理网络覆盖区域的监测信息,并发送给观察者。无线传感器网络在军事侦察、环境信息检测、农业生产、医疗健康监护、建筑与家居、工业生产控制以及商业等领域有着广阔的应用前景。在无线传感器网络中,能量是一种非常宝贵的资源,因为传感器通常由电池供电,而电池提供的能量有限,且传感器通常被部署在无人值守的环境下,不能持续充电。为了延长电池的寿命,以达到延长整个网络的生命周期的目的,近年来人们渐渐意识到了借助通信协议或者算法来实现节能的必要性。研究能量高效的通信协议或者算法,已经成为无线传感器网络中最主要的问题。本文首先简单地介绍了无线传感器网络的概念、体系结构、特点以及应用前景等等,然后研究了无线传感器网络中使用的节能技术,并对典型的无线传感器网络节能路由算法进行总结、分析与比较。无线传感器路由算法有平面路由算法和层次路由算法,层次路由算法是目前无线传感器网络路由算法研究的重点,LEACH(Low Energy Adaptive Clustering Hierarchy,LEACH)算法是最典型的层次路由算法之一,它激发了许多层次路由算法的产生,因此选择LEACH算法为重点研究对象。通过分析LEACH算法和其他算法提出改进思路,从而形成一种新的无线传感器网络节能路由算法——B-LEACH(Based on Low Energy Adaptive ClusteringHierarchy,B-LEACH)算法。LEACH算法采用随机选取的方式产生簇首,再根据最小通信能量原则形成簇;而B-LEACH算法先形成簇首集合,再在簇首集合内根据节点的剩余能量来选择簇首,成簇后离Sink节点距离近的簇半径较大,而离Sink节点距离远的簇半径较小。改进后算法实现了网络负载的均衡,节省网络能耗,有效地延长了网络寿命。最后介绍了网络仿真软件NS2(Network Simulator version 2,NS2),详细地叙述了NS2中仿真和开发的一般过程,并利用NS2在50m×50m和100m×100m两种不同的网络场景中对LEACH算法、LEACH-C(LEACH-centralized)算法和B-LEACH算法进行了仿真实验,从网络寿命、Sink节点接收到的数据量和网络能耗三个角度对实验结果进行了总结与分析。实验结果表明,改进后的算法更好地平衡了网络负载,节约了系统能量,提高了网络的使用寿命,且改进后的算法在100m×100m网络场景中的性能较50m×50m网络场景更为突出。更多还原

【Abstract】 Wireless sensor network can be defined as a multi-hop and autonomous network system consisting of a collective of sensor nodes designed to intercommunicate via wireless radio. It can acquire and process information, and transfer information to the terminal users. Wireless sensor network has comprehensive application prospect in many fields, such as military, environmental monitoring, agriculture, health care, space exploration, industry, civilian and home networks.Being limited by the application environments, wireless sensor networks which use wireless communication technology are different from traditional networks because the battery being used can not be recharged. Therefore, making full use of energy efficiently and prolonging life time becomes the main issue of sensor networking designing.The article introduces simply the concept、system structure、characteristic and application prospect of wireless sensor network, and researches the power-saving technology used in the wireless sensor network, and summarizes、analyzes and compares typical power-saving routing algorithm for wireless sensor network.Hierarchical routing is the research hotspot in routing algorithm for wireless sensor network. LEACH (Low Energy Adaptive Clustering Hierarchy, LEACH) is one of the most typical routing algorithm which causes the appearance of many hierarchical routing. So the article raises a new routing algorithm based on LEACH algorithm by analysis of LEACH algorithm and other algorithms.The clusters are built after cluster-heads are selected in LEACH algorithm, so cluster-heads spend more energy; the periodic establish of clusters and selection of cluster-heads need cost the extra expenses; the distribution of the clusters is unreasonable because of the random choice of cluster-heads. The article improved on LEACH algorithm in three ways. The improved algorithm uses the stationary cluster; the shape of the cluster is unequal, the radius of the cluster that is far away from the Sink node is smaller than the radius of the cluster that is close to the Sink node; the cluster-heads will are selected according to the present energy of the nodes. The new routing algorithm is named B-LEACH (Based on Low Energy Adaptive Clustering Hierarchy, B-LEACH).B-LEACH algorithm can utilize the energy of the sensor nodes and prolong the lifetime of the whole network. Finally, the article introduces the simulation software NS2(Network Simulator version 2) and the process of the simulation, and realizes the simulation of LEACH algorithm、LEACH-C(LEACH-centralized) algorithm and B-LEACH algorithm in 50m×50m and 100m×100m network, and analyzes detailedly the simulation result in three ways: the network lifetime、the number of data signals received at the sink node and the energy dissipated in the network. The simulation studies show, B-LEACH algorithm performs better than LEACH algorithm and LEACH-C algorithm in the index of the network lifetime、the number of data signals received at the sink node and the energy dissipated.更多还原