無線隨意網路多重擇路協定

Abstract

在無線隨意網路中，對於支援多重傳輸應用的需求越來越增加， 在多重傳輸裡其中一個我們關切的議題為擇路協定的設計，普遍來說 多重擇路協定可以區分為樹狀結構和網狀結構，在不同的網路環境情 況下，兩種類型的擇路協定分別有各自的優點和缺點。 在本論文中，兩種改善的多重擇路協定被提出。PCHMR 協定同 時結合了樹狀結構以及網狀結構，同時路徑決定機制中除了路徑上的 節點數之外，還把接收信號的強度一併考慮。ORODMR 協定則利用 接收節點的資訊，減少了傳統ODMRP 協定中所需傳送的額外控制封 包量，ORODMR 協定保留了原始ODMRP 協定的優點，同時去改善 ODMRP 協定為人所詬病的其一主要缺陷。透過模擬，在不同的節點 移動模式和網路狀況下，評估提出協定的效用。

There has been an increasing demand for applications to support multicast communication in the mobile ad hoc networks. One of the primary concerns in the multicast communication is the feasible design of the multicast ad hoc routing protocols. Conventionally, the design of the multicast routing protocols can be categorized into the tree-based and the mesh-based schemes. These two types of protocols have their own strength and weakness under different networking scenarios. In this thesis, two multicast routing protocols are proposed. A Power-Controlled Hybrid Multicast Routing (PCHMR) protocol is a hybrid scheme, which consists of both the tree-based and the mesh-based structures. The route determination scheme of the PCHMR algorithm not only relies on the hop counts but also on the received power strength of the neighborhood nodes. The proposed PCHMR algorithm is suitable for the dynamically changing network topologies, especially for the group mobility scenario. On the other hand, a Overhead-Reduced On Demand Multicast Routing (ORODMR) protocol, which reduces the control overhead in the conventional ODMRP algorithm, is proposed. The ORODMR protocol uses the information from the multicast receivers to reduce the control overheads effectively. The ORODMR algorithm keeps the advantages of the original ODMRP algorithm and improves one of its primary drawbacks. Different conditions associated with the mobility models are utilized in the simulations to evaluate the effectiveness of both the PCHMR and the ORODMR algorithms.