无线局域网结课论文

802.11无线局域网安全及防范措施802.11 WLAN security and preventive measures

摘要：

首先简要介绍了IEEE802.11无线局城网技术标准。而在无线网络发展的同时，安全问题也慢慢显现出来。本文分析了基于IEEE802.11无线局域网中存在的安全问题，并提出了相应的防范措施，最大程度保证无线网络的使用安全。

关键词：无线局域网；IEEE802.11协议；安全五要素；跳频技术；直接序列扩频；

Abstract—firstly，we give a brief introduction of technical standards. However，with the development of the wireless LAN, security issues are slowly revealed. This paper analyzes the security problems existed in the IEEE802.11 wireless LAN, and proposed the corresponding preventive measures to ensure the maximum and safe use of the wireless network.

Index Terms—wireless LAN，IEEE802.11 Protocol，Five elements of security，frequency-hopping technology，Direct Sequence Spread Spectrum.

一绪论

I Introduction

1.无线局域网

无线局域网(WLAN)是用无线通信技术构建的局域网,虽不采用缆线,但也能提供传统有线局域网的所有功能,与有线局域网相比,WLAN具有移动性好、灵活性高、建网迅速、管理方便、扩展能力强等优点。无线局域网技术目前主要有两大阵营,即IEEE802.11系列标准和欧洲的HiperLAN。其中以IEEE802.11系列标准中的802.11b产品在目前占主导地位。

1. Wireless LAN

WLAN is a LAN built with wireless communication technology. Though do not

use any cable, it can provides all the functionality of traditional wired LANs, compared with wired LAN, WLAN has many advantages, such as good mobility, high flexibility, rapid network construction, easy management and good scalability. Wireless LAN technology has two main camps currently that is IEEE802.1and HiperLAN in Europe. Dominance between them is 802.11b of IEEE802.11 Series of standards.

2. IEEE802.11技术标准

IEEE802.11是在1997年由众多的局域网以及计算机专家审定通过的标准,主要规范了开放式系统互连参考模型(OSI/RM)的物理层和媒体接入控制(MAC)层,支持1～2Mbit/s的数据速率。1999年8月,802.11标准得到了进一步的完善和修订,增加了2项内容,一是802.11a,传输速率为6Mbps～54Mbps,支持语音、数据、图像业务,能满足室内、室外的各种应用场合。另一种是802.11b标准,该标准可提供11Mbps的数据速率,大约是原来IEEE标准无线局域网速度的5倍。现在大多数厂商生产的WLAN产品都基于802.11b标准,见表1。

2. IEEE802.11 technical standards

IEEE802.11 is standards approved by many LAN and computer experts in 1997. It primarily regulated the Physical Layer of OSI/RM and MAC Layer, and can support 1 ~ 2M bit/s data rate. In August 1999, The 802.11 standard has been further improved and revised. Two elements added. One is 802.11a standards, the transmission rate is 6Mbps ~ 54Mbps, supporting voice, data, image services, can be used in indoor, outdoor and Many occasions. The other one is 802.11b standers, which can provide a data rate of 11Mbps, about 5 times the speed of the former, and now most manufacturers’ WLAN products are based on the 802.11b standards shown in table 1.

表1 IEEE802.11参考模型

二无线局域网安全及防范措施

1. IEEE80

2.11

802.11协议组是国际电工电子工程学会（IEEE）为无线局域网络制定的标准。WIFI使用了802.11的媒体访问控制层(MAC) 和物理层(PHY)，802.11采