針對特殊無線網路設計的一個混合式路由方法

Abstract

無線網路可依據擷取點(access point)的存在與否分為兩類，一為基礎架構(infrastructure)網路，另一為特殊無線網路(ad-hoc network)。在特殊無線網路中，每一個行動主機(mobile host)皆須扮演幫忙轉送封包的角色。亦即每個行動主機皆為一特殊的路由器(router)。然而行動主機的路由路徑(routing path)會因行動主機自由移動而改變。在本論文中，我們運用個人通訊系統(personal communication system)的架構，藉由一種階層式路由樹(hierarchical routing tree)的建立，讓所有行動主機能迅速地找出到擷取點的路由路徑。藉此讓行動主機能與網際網路的主機建立連結而相互傳輸資料。此外在內部無線區域網路中，行動主機若想建立的目的端主機也是位於內部的無線區域網路中，這種內部點對點的路由方式我們採用依需求的距離向量(AODV)路由方式來改善階層式路由樹在行動主機間點對點較無效率的路由方式。

Wireless networks can be classified into two kinds of networks according to the existence of the access point. One is the infrastructure network and the other one is the ad hoc network. In ad-hoc networks, each mobile host plays a role of forwarding packets from one to another. i.e., each mobile host acts as a specific router. However, the routing path in the ad hoc network will vary often due to the movement of mobile host. In this thesis, we apply the concept of hierarchical architecture in personal communication services (PCS) for ad hoc network routing. By the construction of hierarchical routing tree (HRT), each mobile host can find its routing path to access point quickly. Thus, mobile hosts in ad hoc network gain the access on Internet. In addition, we choose the AODV (Ad-hoc On-demand Distance Vector) routing protocol as the point-to-point routing method inner the ad-hoc network to improve the weakness of HRT method.