因應科技發展的進步，移動設備使用者對於網路的需求量逐漸增加，傳統類型的網路已漸漸不敷使用，並且隨著使用者的使用方式改變，各式各樣的裝置改變了傳統的使用習慣，對於網路的需求不再只是位於一固定位置，而是期望能夠隨著使用者移動提供更好的網路服務品質，這也成為現今無線網路傳輸所面臨的課題。
隨著環境中架設LTE基地台及Wi-Fi AP佈署的增加，使用者對於網路服務有了更多的選擇，由於前者能提供的服務範圍較後者廣，但使用LTE網路是需要付費的，而使用Wi-Fi網路則是免費的，因此，對使用者而言，能盡可能的選用Wi-Fi是較好的，但當目前所使用的Wi-Fi網路已無法滿足使用者需求，必須切換至LTE網路時，現在的方法是由使用者自行手動調整，而沒有一套較智能的換手機制，因此本篇論文嘗試提出一套較智能的換手機制來取代目前的方法。
本篇論文所提出的方法會讓使用者根據目前的網路環境狀況來做判斷，由使用者目前連現狀況又分為三種case，依照每種case訂定出不同的限制條件以及提出三個演算法，讓使用者能依據演算法做出判斷，切換至能提供較好服務的網路，滿足使用者的需求。
由模擬結果顯示，本篇論文所提出的方法與傳統Wi-Fi連線的方法相比，能服務較多的使用者且有較大的平均總吞吐量，特別是在環境負載很重的情形下，會有較好的表現。

In view of the progress of the development of science and technology, users demands for the network gradually increased. The traditional networks have gradually become inadequate. With the change of usage habit, the connection for a user to the network is no longer just in a fixed location, but rather hope to provide better quality of network services when a user is moving, which has become an important subject of today''s wireless network transmissions.
While the deployment of LTE base stations and Wi-Fi APs in the environment increased, users have more network services to choose. The LTE base stations can provide a wider range of services than the Wi-Fi AP. However, using the LTE network is usually required to pay but using Wi-Fi network is often free. Therefore, it is better to choose Wi-Fi for a user as much as possible. As the current Wi-Fi network has been unable to meet the needs of users and the user must switch to the LTE network, the current method is adjusted by the user. Hence, we attempt to propose a more intelligent handover mechanism to replace the current method.
In our paper, we proposed a handover mechanism for user to make judgments based on the current situation of the Internet environment. According to the current situation we divided it into three cases, and users can make judgments based on the algorithm to switch to a better service to provide the network to satisfy the needs of users.
According to the simulation results, compared with the traditional Wi-Fi connection method, our method can serve more users and have a larger average total throughput, especially in the heavy load situation, there will be a better performance.

學位論文審定書 i
論文公開授權書 ii
論文摘要 iii
Abstract iv
目錄 v
圖目錄 vii
表目錄 ix
第一章 導論 1
1.1 前言 1
1.2 研究動機 4
1.3 論文架構 5
第二章 相關背景與研究 6
2.1 長期演進技術(LTE)簡介 6
2.2Wi-Fi架構簡介 9
2.3換手技術(Handover) 12
2.3.1換手技術分類簡介 12
2.3.2 LTE換手技術 14
2.3.3 LTE-WiFi間的換手架構 20
2.4相關論文 22
第三章 研究方法 24
3.1 系統架構 24
3.2 基地台負載 28
3.3 情境探討 31
3.3.1 Wi-Fi AP間的換手 31
3.3.2 Wi-Fi網路換手至LTE網路 33
3.3.3 LTE網路換手至Wi-Fi網路 37
第四章 效能與分析 39
4.1 模擬環境與參數設定 39
4.2 模擬結果與效能分析 40
第五章 結論 62
參考文獻 63

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