本論文在Application Layer以及Transportation Layer之間加入可動態調整視訊影像Frame Rate之Rate Control法則，我們稱之為優先權訊框丟棄(Priority Early Frame Discard, PEFD)法則來執行TCP協定上視訊串流之彈性QoS。值得注意的是在廣播服務時，固定的QoS可能無法同時滿足複雜的網路環境以及多樣化接收端的需求。不僅如此，當使用者的頻寬不足或是解碼速度過慢時，傳送過多的資料可能會造成傳送延遲，或是由於傳送端TCP BUFFER產生Overflow而讓畫面流失。因此我們讓每一接收端皆獨立使用PEFD法則，並綜合考慮網路頻寬、接收端運算速度以及畫面重要性來主動執行畫面刪除，以提供合適的QoS，並降低傳送延遲以及畫面流失。

This thesis develops a surveillance system which has flexible quality of service for TCP-based video streaming in accordance with the network bandwidth and computational capabilities of video decoder. To allow the flexible for TCP-based video streaming, the thesis proposes a novel frame-discard algorithm, termed Priority Early Frame Discard algorithm, which actively discarding necessary frame data and effectively controlling the frame rate of the encoded video sequence in the IP Camera for video streaming. Note that broadcast services with a unified quality of service may not be well suited for different network environments and/or receivers. Insufficient network bandwidth and/or decoding speed for given video bit streams may result in transmission delay. The Priority Early Frame Discard algorithm will be employed for each receiver to solve this problem. It actively discards encoded frames for each receiver in accordance with the network bandwidth and the decoding speed of that receiver. The algorithm therefore provides quality of service well-suited for each receiver, and eliminates possible transmission delay.

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