摘要:面对日益增长的高速无线因特网接入需求,传统的无线接入方式,如蜂窝网、无线局域网(WLAN)面临许多挑战,而无线网状网(WMN)作为因特网“最后一公里”接入方案,提供一种灵活而低成本的多跳通信,也将成为各种无线网络融合的主要技术。针对这一极具发展前途的网络结构,从WMN的两种典型应用出发,文章从网络配置、功率控制、移动性管理和接入控制以及路由协议设计等方面说明了WMN组网中的相关问题和技术,对WMN与移动自组织(Adhoc)网路由协议的设计进行了对比,并给出了一种基于WLAN和第二层交换技术的WMN试验床实现方案。
关键词:无线网状网;路由;网络管理;试验床
Abstract:With the increasing popularity and rising demand for high-rate wireless Internet access, traditional wireless access networks such as the cellular network and Wireless Local Area Network (WLAN) are facing some challenges. The Wireless Mesh Network (WMN) is emerging as a flexible and low-cost alternative to provide multi-hop communications, supporting applications such as last-mile Internet delivery. WMN has also become a promising technique in the merging of wireless networks. Some key technologies about the network management in WMN, including network configuration, power control, mobility management, access control and routing protocol are analyzed; the routing protocol design in WMN and mobile Ad hoc network are compared. An example of WMN testbed based on WLAN and second-layer switching technology is given.
Keywords:wireless Meshnet work;routing;network management; testbed
1无线网状网的介绍
无线Mesh网(WMN)又称为无线网状网、无线网格网,大约出现在20世纪90年代中期。随着移动通信技术的发展,除无线通信网络的语音业务需求外,高速因特网接入需求也日渐增加。传统的无线接入方式面临着接入带宽不足、服务质量得不到满足等问题,而且无线频谱资源及拓扑结构缺乏统一规划,难以适应灵活多变的使用状况。WMN提供了一条解决无线接入网所面临问题的新途径。
通信网络的拓扑结构通常抽象成一个图G(V,E),其中,V代表通信节点的集合,E代表着通信链路的集合。无线Mesh网的最初定义[1],就是指无线通信网络的网络拓扑可以抽象成一个连通图,对图中的任意两个顶点vi,vj∈V,vi和vj之间是连通的,即存在一条或多条从vi到vj的路径,定义为顶点集合(vi =vp,0,vp,1……vp,m=vj),其中(vp,n-1,vp,n)∈E,1≤n≤m。
