工学硕士学位论文
（中职教师在职攻读硕士学位研究生）
IEEE802.11b无线局域网协议性能
分析与研究
韩丽萍
哈尔滨工业大学
2005年12月
国内图书分类号：TN925+.93 国际图书分类号：621.396.2
工学硕士学位论文
（中职教师在职攻读硕士学位研究生）
IEEE802.11b无线局域网协议性能
分析与研究
硕士研究生：韩丽萍
导师：郭庆教授
申请学位：工学硕士
学科、专业：通信与信息系统
所在单位：黑龙江省贸易经济学校
答辩日期：2005年12月
授予学位单位：哈尔滨工业大学
Classified Index: TN925+.93 U.D.C.: 621.396.2
Dissertation for the Master’s Degree in Engineering
STUDY ON PERFORMANCE OF
IEEE802.11b WIRELESS LAN PROTOCOL
Candidate： Han Liping
Supervisor： Prof. Guo Qing
Academic Degree Applied for： Master of Engineering
Specialty： Communication and Information System
Affiliation： Hei Longjiang Trade & Economy School
Date of Defence: December, 2005
Degree-Conferring-Institution: Harbin Institute of Technology
哈尔滨工业大学工学硕士学位论文
摘要
近年来，无线局域网技术逐渐成为了一种流行的网络最后一公里接入技
术，其中IEEE802.11b标准是当前无线局域网协议的主流。IEEE802.11b的
基本结构、特性和服务仍然由最初的IEEE802.11标准定义，IEEE802.11b
标准只影响IEEE802.11标准的物理层，其物理层采用补偿码键控编码技
术，使数据传输速率达到了5.5Mbps和11Mbps。
无线局域网的快速发展，使无线局域网的性能成为人们最关心的问题。
无线网络中介质访问控制 (MAC) 协议用于解决多个用户如何共享信道的问
题，它对无线网络系统的性能起着决定性的影响。良好的MAC协议设计应
该保证在任意的业务负载情况下都有较高的吞吐率、较低的时延以及较少的
开销。
本文重点研究的是基于Shiann-Tsong Sheu等人提出的THN(Tower of Hanio Network)网络模型来对IEEE802.11b协议的MAC子层的性能进行分
析。文中首先介绍了无线局域网的基本概念与国内外的发展情况。然后介绍
了IEEE802.11b的物理层结构，并对IEEE802.11b的MAC子层进行了详细
的阐述，深入地分析了MAC层的帧结构、帧类型，比较了分布式协调功能(DCF)和点协调功能(PCF)两种MAC层接入方式的特点。
接着本文介绍了THN模型的工作原理，包括THN的网络结构、实现
位置检测的方法、实现网络公平性问题及THN的帧格式。最后依据IEEE802.11b协议中规定的DCF和PCF的工作方式，以离散的二维马尔可
夫链为理论依据，对THN的网络吞吐量、时延、数据业务与语音业务进行
了理论分析，得出了数学表达式，通过Matlab仿真得到了相应的性能曲
线，并对性能曲线进行分析，得出不同的数据传输速率对网络性能有不同影
响的结论。
关键词 IEEE802.11b；介质访问控制；吞吐量；时延
- - I哈尔滨工业大学工学硕士学位论文
Abstract
In recent years, the technology of the wireless LAN has gradually become a
kind of popular access network technology for the last kilometer, IEEE802.11b is
the mainstream of the wireless LAN protocol of the day. The basic structure,
performance and service of IEEE802.11b were defined by initial IEEE802.11
standard, IEEE802.11b only affects physical layer of the IEEE802.11, which
physical layer adopts the complementary code keying technology with the data
transmission rate of 5.5Mbps and 11Mbps.
Being the rapid development of the wireless LAN, performance of it make a
greatest concern. The MAC in the wireless network is used for solving the
problem how to share the channel for users, it has decisive influence for
performance of the wireless network system. Good MAC protocol design should
guarantee there are higher throughput, lower delay and less spending in any
service payload.
What this paper researches put forth a THN based on the Shiann-Tsong Sheu,
etc, to analyze the performance of MAC with IEEE802.11b protocol. First, this
paper introduces the basic concept of wireless LAN and developments both at
home and abroad, physical layer of IEEE802.11b and puts forth MAC, then
deeply analyzes frame structure and type, and compares access feature of DCF
with PCF.
Next, this paper introduces the operational principle of THN, including THN
network structure, the method of location detetion, the network fairness problem
and frame format in realization. Finally, according to the working method of
DCF and PCF, the paper analyzes network throughput, delay, data service and
speech service to THN based on two dimensional dispersed Markovs chain to
reach math expression. Through Matlab simulation, performance curves are
correspondingly obtained and analyzed to reach a conclusion that different data
rate have influence upon network performance differently.
Keywords IEEE802.11b, the medium access control,throughput,delay
- - II哈尔滨工业大学工学硕士学位论文
目录
摘要......................................................................................................................I Abstract...............................................................................................................II 第1章 绪论.........................................................................................................1 1.1 无线局域网简介........................................................................................1 1.1.1 无线局域网的概念及发展.................................................................1 1.1.2 无线局域网的优势.............................................................................2 1.1.3 无线局域网的应用环境.....................................................................3 1.1.4 无线局域网的技术要求.....................................................................4 1.2 课题研究的意义、来源及目的.................................................................5 1.3 无线局域网的研究现状............................................................................7 1.3.1 国际的研究现状.................................................................................7 1.3.2 国内的研究现状.................................................................................8 1.4 本论文的主要研究内容和结构.................................................................8 第2章 IEEE802.11无线局域网综述..............................................................10 2.1 IEEE802.11标准系列...............................................................................10 2.1.1 IEEE802.11标准................................................................................10 2.1.2 IEEE802.11b标准...............................................................................11 2.1.3 IEEE802.11a标准...............................................................................11 2.1.4 IEEE802.11g标准...............................................................................12 2.1.5 IEEE802.11n标准...............................................................................12 2.2 IEEE802.11的体系结构...........................................................................12 2.2.1 无中心的对等网络...........................................................................13 2.2.2 有中心的结构化网络.......................................................................13 2.3 IEEE802.11物理层...................................................................................14 2.3.1 跳频扩频...........................................................................................15 2.3.2 直接序列扩频...................................................................................15 2.3.3 红外传输技术...................................................................................16 2.3.4 IEEE802.11b的增强物理层...............................................................16 2.4 本章小结..................................................................................................17 第3章 IEEE802.11bMAC层协议描述............................................................18
- - I