隨著科技的快速發展以及無線網路的普及，平板電腦以及智慧型手機等行動裝置的能力也越來越大，除了單純的文字傳輸和語音通話功能外，也提供了多媒體串流的傳輸、社群網路等多元的服務，使得網路負擔越來越大，因此如何提供更順暢的網路體驗成為各家電信業者相繼競爭的目標。
高速鐵路的興建，使得終端使用者的移動速度遠超於以往行人及車輛之速度。過去的第三代行動網路，由於終端支援速度不足，造成使用者無法在高鐵上有穩定的連接，LTE (Long Term Evolution) 大幅提升支援終端的移動速度，而為提升使用者的網路體驗，LTE-A除了提升了上下行傳輸速率以及頻譜的使用效率，也加入了許多新的技術例如: RN (Relay Node)、多點協調 (Coordinated Multi-Point，CoMP) 等等。
本篇論文利用高速鐵路列車行駛路線固定之特性，藉由將列車視為一個Relay Node與預測封包路徑，來準確的將封包送達將傳遞給列車之基地台上，以減少因列車Handover而造成封包需在基地台間進行移轉，而產生的延遲與遺失率，並在基地台間採取CoMP中的Coordinated Scheduling，藉此改善使用者的網路體驗。
模擬結果顯示，本篇論文所提出的方法，藉由預測封包路徑，可以提升整體有效的傳輸量，並降低封包的延遲時間與遺失率。

With the rapid development of technology and the widespread of wireless networks, the ability of mobile devices likes tablet PCs and smart phones is also growing. In addition to providing text and voice calling, they also provide the diversity service likes the transmission of multimedia streaming and social networking, making the burden of the network more and more heavy. Therefore how to provide a smoother network experience becomes the competing goal of each ISP (Internet Service Provider).
With the construction of high-speed rails, it makes the user move much quicker than the pedestrians and vehicles in the past. In the third generation of mobile networks, due to lack of support for the high-velocity user, the user can not have a stable connection on the high-speed rail. So LTE (Long Term Evolution) boosts supporting the high velocity of terminal to enhance the user's network experience. In addition to enhancing the transmission rate of uplink,downlink and spectrum efficiency, LTE-A also added a lot of new technologies such as RN (Relay Node), CoMP (Coordinated multi-point operation), and so on.
In this paper, we use the characteristic of the fixed path of the high-speed train, by making the train as a Relay Node and predicting the path of a train to accurately deliver the packets to the base station which will transport to the train to reduce the packet delay and loss rate and avoid the packets needed to be transferred between the base stations because of the handover. We further utilize CoMP of Coordinated Scheduling between base stations, thereby improving the user's network experience.
The simulation results show that, by predicting the path of packets, the proposed method in this paper can effectively enhance the overall amount of traffic, and reduce latency and packet loss rate.

論文審定書 i
論文公開授權書 ii
論文摘要 iii
Abstract iv
目錄 vi
圖目錄 viii
表目錄 x
第一章 導論 1
1.1 研究背景 1
1.2 研究動機 3
1.3 論文架構 4
第二章 相關背景與研究 5
2.1 LTE/LTE-A基本系統架構 5
2.2 LTE無線存取技術 8
2.3 換手機制(Handover)介紹 13
2.4 LTE-A多點協調(Coordinated Multi-Point，CoMP)技術 14
2.5 實體上行通道 19
2.6 高速鐵路介紹與相關研究 21
第三章 研究方法 23
3.1 情境假設 24
3.2 Enhanced CSI Report 25
3.3 Enhanced S-GW 26
3.3.1 紀錄歷史資訊與參考資訊之預測 26
3.3.2 預測封包路徑 32
3.3.3 S-GW之處理工作 35
3.4 基地台之封包排序 38
第四章 模擬結果與效能分析 40
4.1模擬環境與參數設定 40
4.2模擬結果與效能分析 42
第五章 結論 51
參考文獻 52

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