行動式隨意網路為沒有固定的基礎架構的無線網路，每一個無線節點可透過直接無線鏈結的方式通訊，或是利用中間節點以連續多點跳躍的無線鏈結方式來通訊。由於節點的任意地移動，使得網路的拓撲變動頻繁，因應這種網路特性需要設計一個有效率的繞路協定。在行動式隨意網路上AODV和DSR是兩個被廣為應用的隨選繞路協定，然而，之前的許多研究發現了兩者的限制。例如，當在傳輸封包的節點移動，節點之間因為距離過遠無法通訊而造成傳輸中斷，必須重新找尋路徑。一般來說，隨選繞路協定皆使用氾濫法來找尋路徑，而氾濫法會大量地浪費網路的頻寬。為了防止這樣的傳輸錯誤和減少氾濫法的使用，這篇論文提出一個隨選混合多重路徑繞路協定，它最大的特色是結合了節點不相交多重路徑和交錯多重路徑，透過理論分析和模擬結果，隨選混合多重路徑繞路協定可以減少氾濫法的使用頻率、提高封包傳輸率和縮短平均的點對點傳輸延遲。這篇論文還延伸隨選混合多路徑繞路協定對多媒體通訊做保證服務品質，我們提出一個多媒體串流分配方法，它依據多媒體串流的優先權，分配多媒體串流於不同的多路徑上，透過模擬結果顯示，隨選混合多路徑繞路協定利用多媒體串流分配方法對於多媒體通訊可達到較好的影像傳輸品質。

A Mobile ad hoc network (MANET) is a collection of wireless mobile computers forming a temporary network without existing wire line infrastructures. Due to the dynamic nature of the network topology and resource constraints, designing an efficient routing in MANETs is challenging. AODV and DSR are two most widely studied on-demand ad hoc routing protocols with low routing overheads. However, previous studies have identified various limitations of these protocols. For example, whenever a node moves and its link breaks on the active route, it can cause a communication fault and then invokes a route discovery process. In general, on-demand protocols use query flooding to discover routes. Such flooding consumes a substantial portion of the network bandwidth. To tolerate communication faults and decrease flooding, this study explores the network redundancy through multipath routing. The designated on-demand hybrid multipath routing (OHMR) features a novel characteristics; it establishes the node-disjoint multipath and the braided multipath between a source-destination pair. Through theoretical analysis and simulation results, we show OHMR can reduce the frequency of route discoveries and achieve a higher packet delivery ratio. Furthermore, the average end-to-end delay for OHMR is shorter than single path, braided multipath and node-disjoint multipath routing schemes. We also extend OHMR with a multimedia traffic allocation strategy to classify multimedia sub-streams among multiple paths according to different priority levels. Our experiments show that the proposed protocol for multimedia communication can improve the performance of the fraction of decodable frames and achieve better performance in terms of video quality over the node-disjoint multipath.

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