摘要无线传感器网络是一类由大量位置相对固定的节点所组成的无线通信网络，其节点能量、计算和通信能力都非常有限，传统网络的层次设计和网络协议都难以应用到无线传感器网络中。本文以目前公认的用于无线传感器网络的ZigBee协议为基础，基于专业的用于模拟通信系统和预测网络性能的OPNET软件平台，构建了适用于传感器网络的节点模型；基于OPNET 实现了IEEE802.15.4标准规范的信标使能模式下的有时隙CSMA/CA机制。在建立节点模型的基础上，本文分析了该机制用于以星型网络拓扑和广播方式传输数据的传感器网络中的性能，通过改变不同的网络设置，来分析有时隙CSMA/CA机制中规定的属性对网络的性能的影响，即网络吞吐量，平均延迟和传输成功率；并引入了效用这一综合指标以确定特定网络的最优负载的选择。63511

毕业论文关键词  OPNET，无线传感器网络，CSMA/CA，最优负载

毕业设计说明书（论文）外文摘要

Title Model and simulation of wireless sensor network

Abstract OPNET is a powerful network simulator, which can be used to simulate communication systems and predict network performance. Wireless sensor networks (WSN) are a kind of wireless communication network made by a plenty of fixed nodes which have limited energy store and restricted computing and communication ability. Hence, traditional network layer design and network protocol aren’t applicable in WSN. In this paper, based on the ZigBee protocol , which is acknowledged used in WSN, we construct a model of WSN node. Slotted CSMA/CA mechanism of IEEE 802.15.4 in the beacon-enabled mode is realized in OPNET. We only analyze the performance of the slotted CSMA/CA mechanism for broadcast transmissions in WSN. We use the different network settings to understand the impact of protocol attributes on the network performance, namely in terms of throughput, average delay and probability of success. While, we introduce the concept of utility as a combination metrics to determine the best offered load of the network.Keywords  OPNET; wireless sensor network; CSMA/CA; best offered load

1绪论 1

1．1 无线传感器网络概述 1

1.2 无线传感网络的特点与挑战 2

1.3  网络建模与仿真技术 3

1.4  本文研究背景意义和内容 6

2  ZigBee协议及无线信道的建模 8

2.1  无线传感网络的性能评价 8

2.2  ZigBee 技术 9

2.3  无线信道建模 16

3  基于OPNET的节点模型的建立 21

3.1  模型概述 21

3.2  sink 模块 21

3.3  sensory data模块 23

3.4  mac command模块 25

3.5  wpan_mac模块 25

3.6 Battery 模块 32

3.7  物理层 34

3.8  节点级属性 35

3.9  总结 36

4 用节点模型构建网络进行仿真 37

4.1  计算机网络的主要性能指标 37

4.2  网络衡量标准的统计模型