隨著無線區域網路(Wireless Local Area Network, WLAN)和以蜂巢式網路(Cellular Network)為基礎的無線行動通訊技術在近幾年的快速發展，在日常生活中隨處都可以見到無線網路的應用，WLAN與Cellular網路的整合也被熱烈地討論與研究以提高整體的網路傳輸率。
本論文針對有WLAN嵌入的Cellular網路提出了一個具有侵佔機制的通道配置法，由於MN(Mobile Node)會移動的特性，太頻繁的換手會導致整體網路效能的降低，因此我們的方法是讓MN儘可能的使用可以支援高移動性的Cellular網路，只有在Cellular網路中BS(Base Station)的通道不夠使用時，在WLAN範圍外的MN才會以侵佔的方式去迫使WLAN內的BS通道使用者讓出通道，而BS通道被侵佔的MN仍然可以使用WLAN繼續地連上網路。我們以三維的馬可夫鏈來分析本論文所提出的侵佔機制，在數學模型的建立中，由於MN的移動特性與我們所提出的機制息息相關，我們以MN的移動速度、WLAN在Cellular網路中的涵蓋面積、以及BS的涵蓋面積分別推導出MN在WLAN涵蓋範圍內以及WLAN涵蓋範圍外的滯留時間(Residence Time)，最後，我們以WLAN的使用者個數、BS通道使用率、連線中斷率、MN會侵佔的機率、以及MN會被侵佔的機率五個不同的角度來分析整體網路的效能。

The rapid growth of wireless and cellular technologies in recent years has brought in various applications in our daily life. Thus, the integration between WLAN and cellular networks has attracted more and more attention to researchers.
In this Thesis, we proposed a preemptive channel allocation mechanism for WLAN-embedded cellular networks. In such integrated networking environments, frequent handoffs may result in dramatic performance degradation. In our model, a mobile node first utilizes the cellular network for supporting high mobility. However, the capacity of a BS is easily saturated. To minimize session blocking, a mobile node outside the WLAN coverage can preempt the channel(s) occupied by a mobile node inside the WLAN coverage. The preempted mobile node can still get access to the Internet through the AP of WLAN. For the purpose of performance evaluation, we build a three-dimension Markov Chain to analyze the proposed mechanism. We derive the residence time inside the WLAN coverage and outside the WLAN coverage, respectively. Finally, we evaluate the overall network performance in terms of the number of active sessions over WLAN, the channel utilization of a BS, the probability of session blocking, the preemption probability, and the preempted probability. From the evaluation, we observe the relative performance improvements of our proposed channel preemption mechanisms.

第一章 導論
1.1 研究動機
1.2 研究方法
1.3 章節介紹
第二章 異質性網路上的通道侵佔配置法
2.1 有WLAN嵌入的Cellular網路之架構
2.1.1 無線區域網路簡介
2.1.2 蜂巢式網路簡介
2.1.3 無線區域網路與蜂巢式網路的比較
2.1.4 WLAN嵌入的Cellular網路之相關研究
2.1.5 WLAN嵌入Cellular網路運作機制的比較
2.2 具有侵占性的通道配置方法
2.2.1 具有侵佔性的通道配置方法的相關研究
2.2.2 具有侵佔性的通道配置方法的比較
2.3 本論文的通道配置方法
第三章 具有侵佔性的通道配置法
3.1 系統運作流程
3.2 數學模型的建立
3.2.1 網路拓墣
3.2.2 數學模型的假設
3.2.3 馬可夫鏈的設計
3.2.4 移動率及MN滯留時間的推導
3.2.5 馬可夫鏈的狀態轉換率
3.3 效能參數
第四章 數學分析與結果
4.1 穩定狀態機率的求解
4.2 數值結果與網路效能的分析
4.2.1 使用WLAN的平均連線數
4.2.2 BS通道使用率
4.2.3 連線中斷率
4.2.4 MN會發生侵佔的機率
4.2.5 MN會被侵佔的機率
第五章 結論與未來工作
5.1 結論
5.2 未來工作
REFERENCES
Index

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