文档介绍：合肥工业大学
硕士学位论文
多速率环境下无线Adhoc网络的路由研究
姓名:鲁顶芝
申请学位级别:硕士
专业:计算机系统结构
指导教师:吴国凤
2011-04
多速率环境下无线 Ad hoc 网络的路由研究

摘要
IEEE DCF协议以其简易性与健壮性成为目前主流的无线Ad hoc 网
络的MAC协议,其基本思想是载波侦听与冲突避免。同时,DCF协议也提供了
两种数据包传输机制:二次握手机制(又被称作为基本机制)和四次握手机制
(又被称作为RTS/CTS机制)。为了适应时变的信道条件并获得更好的信道利
用率,IEEE ,、2、、11Mbps
四种速率,。因此,为了充分利用多
速率来提高网络吞吐量,设计良好的路由协议至关重要。
传统的无线Ad hoc网络路由协议都是基于单速率环境下设计的,而且大多
数路由协议都以源和目的节点之间的最少跳数为路由判据进行路由选择。由于
高传输速率与有效的传输范围之间存在固有的权衡,最少跳数倾向选择长距离
低速率链路,严重制约网络的吞吐量。同时,经典的通信协议分层思想没有考
虑层次之间的相关性,无法动态适应网络时变的信道质量,造成部分链路不可
用。
本文首先介绍了IEEE ,以及支持多速率的
MAC层自适应机制,并分析了多速率对路由协议的影响。然后,分析总结了多
速率路由研究现状,重点分析多速率跨层路由协议。最后,在分析无线媒介接
入竞争和冲突退避情况的基础上,提出了一个负载感知跨层路由协议(简称
LACR协议)。该协议通过跨层设计方法,利用端到端延迟动态衡量链路带宽,
根据本地的信道忙率来划分网络负载水平进行拥塞控制。同时,它采用了节点
休眠唤醒机制来实现路由且由MAC层检测链路连接性,减少了HELLO分组开
销。仿真结果证明,当网络负载增加时,该路由协议能均衡网络负载,有效地
减少冲突开销,从而提高了网络的整体性能。
关键词:Ad hoc 网络;多速率;信道忙率;跨层设计;路由协议
I
The Research on Routing for Wireless Ad works in
Multi-Rate Environment
ABSTRACT
IEEE DCF protocol is simplicity and robustness, and has e the
mainstream MAC protocol in Ad hoc work. The basic idea of the
protocol is carrier sensing and conflict avoiding. At the same time, the protocol
provides two kinds of packet transmission mechanism: twice handshake mechanism
which was known as the basic mechanism and four times handshake mechanism
which was known as RTS/CTS mechanism. In order to meet the time-varying
channel conditions and get a better channel utilization, IEEE supports
multiple data transfer rate, for example, support four rates such as 1, 2, ,
11Mbps, and support eight rates from 6Mbps to 54Mbps. Therefore, a
well-designed routing protocol is very important in order to take full advantage of
multi-rate to improve work throughput.
The traditional routing protocols were based on single rate in wireless Ad hoc
network. Moreover, most of the routing protocols ch