近年來，Wi-Fi Peer-to-peer (P2P)技術被廣泛討論可以用於支援無基地台網路(Infrastructure-less)或Device-to-device (D2D)網路中的通訊服務，在本論文中我們討論使用Wi-Fi P2P技術來達到可靠地分享檔案之目的，根據Wi-Fi P2P的規範，裝置需要加入一個Group owner所形成之Group才得以與其他裝置間交換資料，而一個Group的連接型態為類似於星狀網路，我們發現到，這樣子的傳輸模式會使得Group owner快速地消耗掉其能量，且使用Wi-Fi P2P廣播方式的封包遺失率高，也降低資料散佈的可靠性。在本論文中，我們提出使用unicast的方式來達成可靠性資料散佈之需求，在所提出之方法中，網路中有多個Group存在，我們將時間切割為時槽，而網路中之裝置依照當下的時槽來決定執行Group內或Group間之通訊，為了管理所形成之Group，我們提出樹狀以及環狀網路拓樸兩種連線方式。模擬與實做結果顯示，所提出之方法能快速且可靠地散佈檔案，且達到電量負載平衡之特性。

Recently, Wi-Fi peer-to-peer technology are discussed to be used to support infrastructure-less or device to device communications. In this work, we use Wi-Fi P2P technology to achieve reliable file sharing. According to the Wi-Fi P2P specification, before a device can communicate with others, this device has to join a group, which formed by a group owner. A topology of a group is like a star network. In the literature, the broadcast reliability of Wi-Fi P2P is low, and the start topology will cause the group owner runs out of its battery quickly. To solve the reliability and energy consumption issues, we propose to use unicast to achieve reliable data broadcast. In our scheme, the network has multiple groups, we divide time into slots. Network devices use the current slots to execute intra-group or inter-group communications. In order to manage the group communications, we propose a logical tree network and a logical ring network. The simulation and prototyping result indicate that the proposed schemes can effectively distribute files quickly and reliable.

目錄
圖目錄                           IV
表目錄                           V
第一章　簡介	                1
第二章　Wi-Fi P2P規範簡介	        4
第三章　邏輯樹狀網路方法	        6
   3.1 網路建立與運作	        7
   3.2 網路維護程序	        9
第四章　邏輯環狀網路方法	        11
   4.1	 網路建立與運作	        13
   4.2	 網路維護程序	        16
第五章　模擬結果	                19
   5.1	 網路建立時間	        20
   5.2	 資料散佈時間	        21
   5.3	 動態網路維護時間	        24
第六章　實做結果	                25
   6.1	 Android Wi-Fi P2P實做	25
第七章　相關文獻	                27
第八章　結論	                29
參考文獻	                        30
附錄-英文論文	                34

圖目錄
圖1: Wi-Fi P2P網路情境	        2
圖2: 邏輯樹狀網路連線圖	        6
圖3: 邏輯環狀網路連線圖	        12
圖4：兩種網路架構在不同up時建立網路所花費的時間	21
圖5：在不同裝置數量下散佈不同大小之檔案時所花費的時間	22
圖6：在不同裝置數量下散佈不同大小檔案時網路中消耗電力最大之裝置的電力消耗量	                22
圖7：環狀及樹狀網路架構在不同upbound時的效能比較	23
圖8：不同無預警離開比例下，兩種網路架構的恢復時間	24
圖9：實做結果示意圖	        26

表目錄
表1：模擬環境參數	                20

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