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。
　　當今異質性網路(Heterogeneous Network)已融入我們所處的環境當中，也就是說有我們身邊有多種網路混合共存的情形，已經是一件非常稀鬆平常的事情，這讓使用者可以因應各種不同的情況來使用著不同的網路存取方式，而在SCTP(Stream Control Transmission Protocol)當中建立關聯(Association)時能夠同
時配置一個以上的IP 位址來作使用，對於現在異質性網路的環境下，擺脫了TCP協定只得使用單一IP 位址的連線限制，此外利用同步多路徑傳輸此特色來增加整體的傳輸效能。
　　而由於在同步多路徑傳輸的使用下，看似能增加效能但事實上並非沒有任何的缺點，其中在選擇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續的現象發生，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考量封包延遲下在CMT-SCTP 的封包排程機制，藉由跨層資訊來考量路徑是否加入排程以及修正當前所測量之RTT(Round Trip Time)，並且根據此延遲來進行封包的排程，並且當RTT 評估錯誤時做出補償的機制，以減少發生Receiver Buffer Blocking 的機率，進而增加整體的傳輸效能。

In recent years, due to the population of mobile devices and growing demand of network services, the wireless network becomes more important.
　　Nowadays, it is very common that there are multiple ubiquitous network around our life, so-called “Heterogeneous Network.” Users can choose any different network interface to fit what situation they are facing in. And the transport layer protocol – Stream Control Transmission Protocol (SCTP), can set up multiple IP address to use while creating the association. It is more suitable than TCP which is restricted in using only single IP address. In the current situation with heterogeneous network, SCTP with the multiple IP address can use the Concurrent Multipath Transfer (CMT) feature, and make transmission performance well.
　　In fact, the Concurrent Multipath Transfer (CMT) has drawbacks while using multiple path to transmission data simultaneously. It causes the Receiver Buffer Blocking problem because of packet loss or different growth rate of paths, and makes the total throughput worse. In our paper, we propose a Delay-Based CMT-SCTP Packet Scheduling Scheme with Consideration of Cross-Layer Information. We use the cross-layer information to determine the path should join the scheduler or not, and then fix
the estimated RTT. Moreover, in order to mitigate the probability of Receiver Buffer Blocking problem, we make some compensation mechanism when we estimated inaccurate RTT. The simulation results show that our scheme have better transmission throughput.

學位論文審定書 i
摘要 ii
Abstract iii
目錄 iv
圖目錄 vi
表目錄 viii
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 異質性網路 4
2.2 WiFi(Wireless Fidelity)技術簡介 4
2.2.1 訊框間隔(Interframe Space, IFS)與延遲(Backoff)機制 5
2.2.2 RTS/CTS與四段交握 7
2.3 串流控制協定(SCTP)的介紹 8
2.3.1 SCTP介紹 8
2.3.2 SCTP特性 8
2.4 相關文獻研究 11
2.4.1 SCTP同步多路徑傳輸(Concurrent Multipath Transfer, CMT) 11
2.4.2 接收端緩衝空間阻塞(Receiver Buffer Blocking)問題相關文獻 14
2.4.3 排程機制之相關方法介紹 15
第三章 協定設定 16
3.1 情境假設 16
3.2 問題描述 17
3.3 機制架構 19
3.4 路徑狀況評估 21
3.5 封包排程機制 23
3.5.1 機制流程說明 23
3.5.2 封包排程機制 27
3.6 RTT評估錯誤補償機制 35
3.6.1 RTT評估錯誤情況說明 35
3.6.2 補償機制 38
3.6.3 封包遺失時處理機制 42
第四章 模擬實驗與結果分析 43
4.1 模擬工具介紹 43
4.2 模擬環境與參數設定 44
4.3 模擬結果與分析 46
4.3.1 評測對象 46
4.3.2 數據分析 47
第五章 結論 53
參考文獻 54

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