在進階長程演進系統 (LTE-A) 網路中，第三代合作夥伴計劃 (3GPP) 提出了機器型態通訊 (MTC)，指在有限的人為干涉之下，裝置間彼此互相傳送資料的通訊方式。在 MTC 裝置中，省電技術是相當重要的議題。
在 LTE-A 中，標準的省電機制為非連續性接收 (DRX)，但該機制是為了一般行動裝置而設計，並不適合 MTC 裝置。在本論文中，我們提出適合 MTC 裝置之樂觀 DRX (ODRX)。
為了更加省電，ODRX 考慮無線資源 (RRC) 的建立與釋放，以及允許更長睡眠週期的樂觀旗標。我們提出了數學模型以及模擬實驗來評估 ODRX 的效能，並在模擬實驗與標準 DRX 以及動態 DRX (DDRX) 比較。實驗結果顯示，ODRX 顯著比標準 DRX 以及 DDRX 更加省電，且只需付出些微增加的封包延遲。此外，我們也提出了設定 ODRX 參數的指導方針。

In Long Term Evolution-Advanced (LTE-A) networks, the Third Generation Partnership Project (3GPP) proposes machine-type communications (MTC) as a new paradigm where devices transfer data among themselves with limited human interaction. For MTC devices, power saving is an important issue. In LTE-A networks, the standard power saving mechanism, called discontinuous reception (DRX), is designed for normal mobile users, not for MTC devices. In this thesis, we propose the optimistic DRX (ODRX) mechanism to be suitable for MTC devices. ODRX considers radio resource control (RRC) connection release and re-establishment to save more power. We also introduce the optimistic flag to allow longer sleep period. Analytical and simulation models are proposed to investigate the performance of ODRX, which is then compared with the standard DRX and dynamic DRX (DDRX) through simulation experiments. The results show that ODRX outperforms standard DRX and DDRX by gaining significant extra power saving with little extra wake-up latency. We also propose guidelines to configure the ODRX parameters.

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