无线传感器网络由协议研究及仿真.pdfVIP

内 容 摘 要 路由协议是无线传感器网络研究的重点之一，其主要的设计目标是降低节点能量 消耗，延长网络的生命周期。本论文首先介绍了无线传感器网络的体系结构、关键技 术及应用前景，然后介绍了国内外对无线传感器网络路由协议研究的现状，最后详细 分析了LEACH 协议并针对它的不足之处作了相应的改进。 LEACH 是一种低功耗自适应分层路由算法，主要的思想是以循环的方式随机分 簇，将整个网络的能量负载平均分配到每个传感器节点上，从而延长网络的生命周期。 LEACH 的运行包含初始化阶段和稳定工作阶段：初始化阶段负责选举簇首、形成分 簇和制定数据传输时隙表；而稳定工作阶段负责数据的采集和发送。虽然LEACH 与 传统的路由算法相比能有效的节省能量，延长网络的生命周期，但它仍然存在一些不 足之处，如它分簇不均，等概率的选择簇首而没有考虑节点的能量因素，这都会导致 簇首的负担过重，进而影响网络的性能。本文针对LEACH 簇首负担过重的问题，提 出了一种改进算法，该算法在初始化阶段考虑节点的剩余能量优化簇首的选取，使剩 余能量高的节点成为簇首的概率增加；在稳定工作阶段，采用双簇首机制传输数据， 在簇内选择次簇首传输数据以此来减少簇首能量损耗。 最后使用NS2 作为网络仿真平台，将改进算法和LEACH 在能量消耗、网络的生 命周期和节点死亡情况三个方面进行了比较。仿真结果显示，改进算法的性能要优于 LEACH 。 关键词：无线传感器网络 路由协议 簇 双簇首 网络仿真 II Abstract Routing algorithm is one of the key technologies of the wireless sensor network. Its main goal is to reduce energy consumption of nodes and prolong the network lifetime. The paper firstly introduces the architecture of wireless sensor networks, key technologies and some applications, and then describes the researches of routing algorithm in the wireless sensor network at home and abroad. Finally, on the basis of LEACH, an improved algorithm is proposed. LEACH is a low-energy adaptive clustering hierarchy routing protocol, which was designed to distribute the energy consumption to nodes in the wireless sensor network evenly by the way of dividing sensor nodes into clusters, so it can prolong the lifetime of the network. The operation of LEACH is divided into rounds. Each round begins with a set-up phase when the clusters are organized, followed by a steady-state phase where several frames of data are transfered from the nodes to the cluster-head and on to the base station. However, some disadvantages also exist in LEACH, such as clusters are uneven and the