【作者】 王建；

【导师】 袁静波；

【作者基本信息】 东北大学 ， 计算机软件与理论， 2013， 硕士

【摘要】 无线传感器网络是由大量具有特定功能的传感器节点,通过自组织的无线通信方式,相互传递信息,协同地完成特定功能的智能专用网络。传感器节点能量有限,并且,通常运行在人无法接近的恶劣或危险的远程环境中,通过更换电池来补充能源是不现实的。因此,如何有效利用各节点能量进行路由转发,并设计高效的路由协议来延长网络生命周期成为无线传感器网络的核心问题。本文首先简单介绍了无线传感器网络的概念、体系结构、特点以及应用,对现有无线传感器网络路由协议进行详细阐述与对比。然后,重点分析了低功耗自适应聚类路由协议LEACH, LEACH协议以循环的方式随机选择簇首节点,将整个网络的能量负载平均分配到每个节点上,从而减低能耗、延长网络的生存时间。然而,该算法在进行簇首选择时采用各节点等概率随机成为簇首的选取方式,没有考虑到节点的剩余能量,可能导致所选的簇首不是最优,从而影响整个无线传感器网络的生存时间,另外,基站往往距离簇头节点较远,远距离的数据发送会造成大量的能量消耗。因此,本文针对LEACH协议的以上不足,随后,提出一种改进的LEACH_IMP协议,该协议充分考虑了节点剩余能量、簇间多跳数据传输等因素,在簇头的选举阶段,通过限制低能量节点参与簇头选取、引入定时器机制以及改进阈值公式,保证了所选出来簇头的健壮性；在数据传输阶段,引入簇头间的多跳数据传输机制,大大降低了由于远距离数据传输所造成的额外能耗。最后,利用NS2仿真平台对提出的路由算法进行仿真和性能评估,并对实验结果进行了分析。仿真实验表明,LEACH_IMP协议在延长网络生存周期、降低网络能耗和提高基站接收的数据量方面均表现出较好的性能。更多还原

【Abstract】 Wireless Sensor Network is an intelligent private network in which a large number of sensor nodes transmit information by means of self-organized wireless communication so as to accomplish a specific function collaboratively. Sensor node, with limited energy, usually runs in a hostile and hazardous remote environment where is inaccessible for human beings,Meanwhile, it is not practicable to supplement energy by replacing the battery. Therefore, the key issue for WSN involves in how effectively use the energy of each node for routing forwarding, and design efficient routing protocols to extend the network lifetime.This thesis first introduces the concept, systematic construction, characteristics and application of the wireless sensor network, then explicate and compare the existing WSN routing protocols. We put emphasis on the Low Energy Adaptive Clustering Hierarchy (LEACH) routing protocol. The LEACH protocol circularly and randomly selects cluster head nodes and distributes the whole network energy load into each node evenly, thereby reduce energy consumption and prolong network life. However, in this algorithm, each cluster head is selected randomly in equiprobability, without taking into account factor like the residual energy of nodes, this may result in the selection of non-optimal cluster heads thus further affect the entire WSN lifetime. The distance between base station and cluster head nodes is often too far, data transmission will cause a large amount of energy consumption. For this reason, given the deficiency of LEACH protocol in cluster heads selection strategy, a novel selection mechanism(LEACHIMP) is proposed. This protocol fully considers the residual energy of the nodes, the inter-cluster multi-hop data transmission etc.,In the cluster head election stage,by limiting the low energy nodes in the cluster head selection,the timer mechanism is put and the threshold formula is improved,this can ensure the robustness of the selected cluster head;In the data transmission phase,multi-hop data transmission mechanism between cluster head is been taken in,greatly reduce the additional energy consumption caused by long distance data transmission.At last, NS2 simulation platform is adopted for simulation and performance evaluation to the proposed routing algorithm. Simulation results analyzed and show that the LEACH_IMP protocol has desirable performance in prolonging network lifetime, reducing energy consumption and improving data reception of the base station.更多还原