高頻寬利用率之SB-RED影像串流傳輸技術

A SB-RED Queue Management for Video Stream over Networks

近年來，在網路上分享與觀看影片成為熱門的應用。然而，影像資料所需的傳輸頻寬較其他類型（例如：聲音、文字）高出許多，因此容易受限於網路頻寬不足而導致影片觀看品質不佳。為了能在有限的網路頻寬下達到改善影像傳輸品質，本論文提出Save Bandwidth RED（SB-RED）佇列管理機制以提高網路頻寬的利用率，此機制參考傳統RED的隨機提前丟棄技術，當網路中的影像封包被丟棄時，SB-RED佇列會根據影像的編碼關係優先選擇發生間接不可解析之影像封包進行丟棄，以保留頻寬給其他有機會被接收端解析之影像封包進行傳送。透過實驗結果分析，證實我們所提出的SB-RED機制可有效利用頻寬資源達到改善網路影像串流之傳輸品質。

Recently, more and more people watch video stream over Internet. However, the requirement of transmission bandwidth for video is higher than voice and text. The video transmission quality is decreasing due to the insufficiently available bandwidth. In this paper, we proposed a queue management mechanism, Save Bandwidth Random Early Detection （SB-RED）, to improve the video transmission quality under the limitation of available bandwidth. The SB-RED scheme drops the received video packet before the queue is full, suchlike the traditional RED scheme. Moreover, in order to increase the bandwidth utilization, the SB-RED scheme also drops the undecodable video packets which lost its depending data of video coding. The numerical results show that the SB-RED scheme improves the quality of video stream by the effective bandwidth utilization.