影像訊號於多工傳輸環境中之流量控制

Abstract

本論文所要探討的是關於壓縮後的影像信號在ATM網路中多工傳輸時的流 量控制. 由於網路頻寬的限制, 網路管理者必須適當的分配頻寬給使用 者,而使用者也必須適當的控制信號量的產生以符合網路的需求.我們將探 討一種利用傅利葉係數在頻域運算時的簡便性來降低頻寬分配所需的複雜 運算量的頻寬分配方法, 此法能夠根據影像特性以及被服務者總數來有效 分配頻寬以減少網路擁擠.同時聯合流量控制以及網路頻寬分配的考慮,我 們將穫得最大的系統效益. This thesis examines the problem of video transmission in a multiplexed environment over ATM network under the constraints of channel bandwidth and MPEG-based codec. Leaky bucket model for burst rate control of video transport over ATM net using MPEG-based compression codec has been proven effective. Network buffer placement is adopted to effectively allocate network chann bandwidth in a multiplexed environment. To improve the system performace, criterion to minimize the bursty probability and buffer overlap is used to allocate multiplexer buffer to each user according to the source characteristics and the total number of sources being served. We show that the Fourier analysis method is effective in network buffer placement, and a control scheme under joint considerations of leaky bucket model and network buffer management is proposed to improve system performace.