近年來，由於行動裝置的蓬勃發展，各式的網路應用服務推陳出新，為滿足逐年飆升的網路需求，LTE-A提出異質網路之概念，可有彈性地佈署小功率基地台於熱點區域以改善網路的頻寬及通訊系統的效能；然而，當網路使用率較低的情況下，大部分的小功率基地台都會處於空轉狀態，無形中浪費許多能源及成本，另一方面，綠能通訊的議題逐漸受到重視，因此，基地台如何在不影響服務品質的前題下達成節能效應是值得探討的問題；此外，電信商為提供使用者不同品質的網路服務，對於大頻寬的網路需求，更需要有效率地分配系統資源，並考量各種資料串流的性質，來制定資源分配排程策略及計價方法。
在本論文中，我們將使用者依優先權分為Golden、Silver、Bronze三類，並提出Energy-Efficient Pricing and Resource Allocation Scheme (E-PRAS)架構，結合計價、資源排程及節能三種層面來提升系統效能，期望在不影響使用者的權益下為電信商降低營運成本並且提升營收；首先，E-PRAS演算法會依據使用者優先權來選擇通道品質較佳的基地台，接著，它評估基地台資源的使用情況，並採用非連續傳輸(DTX)機制，讓資源使用率低的基地台進入低功耗模式，並將其服務中的使用者裝置換手給尚有資源的基地台，以達到節能的效果；此外，E-PRAS架構所設計的排程機制可分為兩層，其中，上層使用改良過的FLS及MT方法，以frame作為單位來計算使用者所需的資源數量，接著，下層則採用M-LWDF的概念，考量到即時性資料流的延遲需求，並將使用者裝置所取得的資源，依其資料流的需求量及迫切性來分配系統資源；最後，在計價策略的部分，為有效平衡尖峰與離峰的網路負載量並同時提升網路的使用率，我們針對尖峰及離峰提出相對應的費用來影響使用者資料傳輸之行為；透過MATLAB模擬並與LTE-A常見的計價機制比較，證實E-PRAS可以提高電信商的營收及降低能源成本，同時實踐綠能通訊的指標。

In recent years, due to the vigorous development of mobile devices, various network services are proposed. To meet the growing demand of network bandwidth, LTE-A adopts the HetNet concept to allow small cells to be deployed in hotspot regions to improve bandwidth and throughput. However, when the network traffic load is low, a large number of small-cell base stations may become almost idle, which waste energy. On the other hand, the issue of green communication attracts attention nowadays. Hence, the issue of energy efficiency becomes important. Moreover, telecommunication operators have to support different QoS levels for different network services. It is critical to schedule network resource for these services to meet their QoS requirements.
In this paper, we consider three-level of users, namely golden, silver, and bronze. Then, we propose an energy-efficient pricing and resource allocation scheme (E-PRAS) that addresses resource scheduling, pricing, and power saving to promote the operator’s revenue, save the energy cost, and improve network throughput. Our E-PRAS framework allows users to select the base stations with good channel quality according to their priorities, and evaluates the resource utilization of different base stations. By adopting the discontinuous transmission (DTX) mechanism, E-PRAS makes those base stations with lower resource utilization enter the low-duty mode and handover its users to other base station to save their energy. The resource scheduling module in E-PRAS has two layers. In the upper layer, E-PRAS uses both FLS and MT methods to calculates the amount of physical resource blocks (PRB) that each user need. Considering the nature of real-time data stream, we then use the M-LWDF scheme in the lower-level scheduler to allocate the PRBs for those flows in danger of packet dropping. Finally, the pricing module in E-PRAS considers adjusting the charges during peak-hour and non-peak-hour time. So, as to increase revenue and throughput. Simulation results show that E-PRAS can increase operator’s revenue and reduce the energy cost, while provides green communications.

論文審定書 i
誌謝 ii
摘要 iii
Abstract iv
目錄 vi
圖次 viii
表次 ix
第一章 導論 1
1.1 前言 1
1.2 研究動機 3
1.3 論文貢獻與章節架構 5
第二章 相關文獻探討 7
2.1 LTE-A系統架構及無線傳輸模型 7
2.2 LTE-A基地台節能機制 11
2.3 計價策略之演進與比較 13
第三章 系統架構與問題定義 19
3.1 LTE-A網路模型 19
3.2 LTE-A基地台節能機制 25
3.3 電信計價模型 29
3.4 問題定義 31
第四章 研究方法 33
4.1 節能之資源分配模組 34
4.1.1 階段一：考量UE等級和通道品質(SINR)選擇連 線之基地台 36
4.1.2 階段二：計算基地台資源之使用情況 37
4.1.3 階段三：調整基地台的運行模式及調整UE連線 38
4.1.4 階段四：分配資源 40
4.2 計價模組 45
4.3 E-PRAS演算法討論 47
第五章 實驗結果分析與討論 50
5.1 模擬環境與參數設定 50
5.2 電信商營收及系統效能分析 54
5.2.1 電信商營收之比較 54
5.2.2 系統效能之比較 56
5.3 系統能源消耗及封包遺失率 58
5.3.1 系統能源消耗之比較 59
5.3.2 封包遺失率之比較 60
5.4 熱點情況下之系統效能分析 62
5.5 模擬全天流量之系統效能分析 66
5.6 離峰期間之系統效能分析 68
第六章 結論與未來研究方向 72
參考文獻 73

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