有別於以往傳統儲存轉發的傳輸機制，網路編碼可在封包被傳輸之前，將不同來源端所送出的封包結合。近年來很多研究顯示，無線網路廣播的特性，應用上網路編碼的技術，可以有效的提升整體的網路效能。在無線網路中，封包是透過廣播到特定範圍來傳送，因此其鄰居節點能有機會竊聽到其他點所傳輸的封包。當節點有傳送機會時，考慮其他節點所偷聽到的封包資訊，則可以利用編碼來減少傳輸的次數。在本論文我們將研究結合網路編碼與媒體存取控制，來改善無線網路的效能。

Unlike the traditional store-and-forward mechanism in packet-switching networks,network coding schemes could combine and modify the contents of a number of packets from different source before the packets are forwarded.It has been recently shown that network coding techniques can significantly increase the overall throughput of wireless networks by taking advantage of their broadcast nature. In wireless networks,each transmitted packet is broadcasted within a certain area and can be overheard by the neighboring nodes.When a node needs to transmit packets,it employs the coding approach that uses the knowledge of what the node's neighbors have heard in order to reduce the number of transmissions.
In this thesis,I propose jointly designing the network coding scheme and the media access control scheme to improve the performance of wireless networks.

致謝 I
中文摘要 II
ABSTRACT III
目錄 IV
圖目錄.. VI
第一章 緒論 1
1-1 網路編碼的簡介 1
1-2 無線網路之網路編碼 3
1-3 文獻探討 4
1-4 研究動機與目標 7
1-5 文章組織 7
第二章 系統模型 8
2-1 模型架構 8
2-2 預測性輪詢演算法 10
2-3 考量封包生命時間之預測性輪詢演算法 19
第三章 網路編碼排程演算法 24
3-1 問題描述與介紹 24
3-2 編碼架構 25
3-3 最大編碼機會優先演算法 28
3-4 模擬結果 33
第四章 模擬結果 37
4-1 模擬方法與環境與參數 37
4-2 各節點之封包到達率皆相同，各節點之封包生命時間皆相同 38
4-3 各節點之封包到達率不完全相同，各節點之封包生命時間皆相同 40
4-4 各節點之封包到達率皆相同，各節點之封包生命時間不完全相同 42
4-5 各節點之封包到達率不完全相同，各節點之封包生命時間不完全相同 44
第五章 總結 47
參考文獻 48

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