行動網路技術日新月異，如何有效的將有限的資源做最好的分配是一大難題，本論文針對LTE/LTE-A下行網路設計出兩個完善的排程機制，可以在保障即時性資料流服務品質的前提下提升整體公平性。

排程即是在數個等待被服務的資料流中挑選出當下最需要被服務的資料流，目前主流的排程機制如M-LWDF、M-EDF-PF、Log Rule、EXP/PF及FLS雖然能夠保證即時性資料流的服務品質，但卻沒有對非即時性資料流設計任何補償機制，即時性資料流常有被優先服務的權力，可能發生非即時性資料流餓死的現象，嚴重導致非即時性資料流公平性下降，因而使整體公平性降低。本論文旨在設計能夠保有即時性資料流的服務品質，且還能維持非即時性資料流公平性的排程機制，利用隨者時間累加的特性，使原本低優先權的資料流慢慢累加成高優先權並取得服務機會，可以有效減少餓死現象，並提升非即時性資料流公平性，藉以提高整體公平性。本論文使用五項指標來評斷排程機制的優劣，分別為產能、公平性、延遲、延遲抖動及封包遺失率。透過模擬結果顯示，本論文所提之方法公平性確實比主流排程機制來得好且其他各項指標皆能夠符合各種資料流的服務品質需求。

As the technology of mobile communication networks evolves, how to allocate limited resources efficiently is still a hot issue to be solved. Aiming at this issue, two scheduling algorithms will be proposed for the downlink of LTE/LTE-A in this thesis to greatly enhance the fairness while guaranteeing the quality of service (QoS) of different service flows.

As one knows, scheduling addresses the selection of service flows according to QoS, channel quality, and etc. In the literature, the existing scheduling algorithms for LTE/LTE-A, e.g., M-LWDF, M-EDF-PF, Log Rule, EXP/PF, and FLS, could meet the QoS requirements for real-time (RT) service flows, but almost no compensation is provided for the non-real-time (NRT) service flows in these algorithms. Therefore, RT service flows always get higher priorities than NRT service flows, leading to the starvation and lower fairness for NRT service flows. To address such an issue, this thesis targets to design two scheduling algorithms to not only guarantee QoS of RT service flows but also enhance fairness of NRT service flows. Examining performance metrics, including throughput, fairness index, delay, delay jitter, and packet loss ratio, the proposed scheduling algorithms are evaluated accordingly with comprehensive comparison to some closely related algorithms in the literature. As revealed by our simulation results, the proposed algorithms successfully achieve better fairness while guaranteeing QoS of different service flows as compared to the closely related algorithms and are highly recommended for LTE/LTE-A.

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