No description available.

在無線傳輸網路環境日益普遍的今日，以往各類型只在固定網路傳輸上的應用都紛紛的套用在具移動性要求的無線傳輸網路上。然而無線網路的傳輸環境比固定網路有更多使用上的條件限制以及需克服技術上的問題，像是與基地台傳輸距離的限制而產生對傳輸連線上換手( Handover )的需求，以及因為換手而導致傳輸時各種時間上的延遲( Delay )和抖動( Jitter )，若是多媒體 (Multimedia) 的多點傳輸( Multicasting )需求，則更要對傳輸內容的特性和傳輸協定的可靠性、可擴展性及穩定性加以考量。再者因為在無線傳輸環境中接收端和發送端都可能是處於移動的狀態，所以整個傳輸架構的健全性 ( Robustness )也十分重要。基於這些需求，本論文提出利用跨層(Cross Layer)設計來匯集較低網層協定在傳輸速率(Throughput)上的優勢，以及由較高網層協定提供之針對傳輸內容不同需求的應用彈性，降低協定在既有網路中實現的困難度，以期Wireless網路提供多點傳輸時在滿足穩定性及可靠性的要求下，達到最佳的傳輸速率表現。 / Applications of wireless mobile network are prevalent in recent years. Many applications inherited or developed from wired network have been proposed to enable mobile nodes to connect to wireless mobile network to access resources/services from Internet using multicasting protocol. However, wireless mobile networks have difficulty in forwarding information due to its inherent dynamism and frequent topology changes. To multicast multimedia data stream, we have to consider not only the issues of reliability, robustness, scalability and stability of routing protocol, but also the content of transmission. Besides, when handover occurs frequently during transmission, the throughput decreases rapidly due to severe jitter and delay. This thesis presents a hybrid multicasting policy for wireless mobile network to build a multicasting architecture using cross layer design of network layer and application layer to manage quality transmission according to flexible requirements. In summary, our goal is to optimize throughput in order to fulfill the requirement of reliability and stability of multicasting in wireless mobile network.