近年來由於手持式行動運算裝置發展迅速，以及網路通訊設備的各種改進，使得人們使用網路的習慣不再侷限於有線網路，越來越多人透過無線網路來瀏覽各種訊息。
因為生活周遭有各種不同的無線網路，手持式行動運算裝置通常搭載著兩種以上的網路存取方式，讓使用者可以因應各種不同的情況來存取網路，但是在傳統TCP的建立連線架構中，卻只能使用單一IP位址；然而在SCTP(Stream Control Transmission Protocol)當中建立關聯(Association)時，卻能夠同時配置一個以上的IP位址使用，擺脫了TCP協定只得使用單一IP位址的連線限制，並且利用同步多路徑傳輸的特色，來增加整體的傳輸效能。
在同步多路徑傳輸的使用下，看似能增加效能且沒有任何的缺點，但在使用多條路徑同時傳送時，可能會因為封包遺失或者路徑速率成長不一，而導致封包傳遞錯序的現象發生，進而導致接收端緩衝空間阻塞(Receiver Buffer Blocking)的問題發生，因此造成整體的傳輸效能衰弱。
因此本篇論文提出一個在CMT-SCTP下，考量封包延遲排程的改進機制，藉由跨層資訊、計算路徑權重、挑選路徑參與排程機制，以及在網路狀況都不好的時候，使用另一種排程機制，進而增加整體的傳輸效能。

In recent years, due to the rapid development of smartphones and wireless network communications, more and more people use smartphones to surf the Internet by wireless networks.
Because there are many different types of wireless networks, the smart phones often are equipped with more than two network interfaces. Users can choose the interfaces to access the Internet depending on networks connections.
In the Transmission Control Protocol, the smartphones use only one interface with single IP address. However, in the Stream Control Transmission Protocol (SCTP), we can set up multiple IP addresses to be used while creating the association.
SCTP with the multiple IP addresses can use the Concurrent Multipath Transfer (CMT) feature, which can make transmission performance well.
But, the Concurrent Multipath Transfer (CMT) may have some drawbacks.
By simply sending data simultaneously through multiple paths, a better transmission performance may not be achieved. Factors such as packet losses, congestion window sizes, and round trip time (RTT) can lead to a problem called receiver buffer blocking which degrade the total transmission throughput.
In our paper, we propose an adaptive packet scheduling scheme. The scheme considers the cross-layer information and path characteristics. It uses these information to choose the scheduling scheme among two schemes and to determine the number of paths for current transmissions. As a result, we can transmit the data efficiently.

學位論文審定書 i
論文公開授權書 ii
摘要 iii
Abstract iv
目錄 v
圖目錄 vi
表目錄 vii
第一章 導論 1
1.1 前言 1
1.2 研究動機 2
1.3 論文架構 3
第二章 相關背景與研究 4
2.1 串流控制協定(SCTP)介紹 4
2.2 SCTP的同步多路徑傳輸(CMT-SCTP)介紹 10
2.3 接收端緩衝空間阻塞問題與相關文獻 12
第三章 協定機制制定 16
3.1 情境假設 16
3.2 問題描述 17
3.3 機制架構 20
3.4 取得跨層資訊 21
3.5 修正後的DAPS排程機制 22
3.5.1 修改路徑取得的RTT 24
3.5.2 計算每條路徑的權重值 27
3.5.3 修改DAPS方式排程 29
3.6 修正後的Bicasting排程機制 34
第四章 模擬實驗與結果分析 35
4.1 NS2簡介 35
4.2 模擬環境與參數設定 36
4.3 模擬結果與分析 38
4.3.1. 評測對象 38
4.3.2. 數據分析 39
第五章 結論 50
參考文獻 51

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