| Summary: | 碩士 === 國立交通大學 === 網路工程研究所 === 100 === In this thesis, we propose a performance analytical model for single-tree and multiple-tree streaming mechanisms and an algorithm to determine if a single-tree or multiple-tree structure should be used according to these analysis results. Our analytical model targets multiple sources, server-less, and tree-based streaming for video conferencing application. Through analyzing and modeling three performance metrics of video streaming, such as bandwidth, delay, and synchronization, and according to our analyses of tree-based streaming, we embody these models and design the algorithms for spanning tree and calculation of maximum delay.
First, in regards to analysis of bandwidth, we discuss bandwidth requirement for single-tree and multiple-tree. We need to identify the required bandwidth to send all streams and differences between single-tree and multiple-tree. However, since we assume that each peer with sufficient bandwidth receives the streams directly or indirectly from other peers, we are interested in uploading bandwidth requirement. Through analyzing, the total upload bandwidth requirement of single-tree is larger than that of multiple-tree. Second, in analysis of delay, operation of single-tree is different from multiple-tree. Single-tree must be considered upload and download delay, and multiple-tree just is considered upload delay of each tree. Finally, in analysis of synchronization, in the single-tree system, a participant with the maximum upload bandwidth serves as a centralized multipoint control unit (MCU) who deals with synchronization. In a multiple-tree system, each participant deals with its own synchronization.
Bandwidth and delay modeling are based on our analyses. Nevertheless, since we regard overhead of synchronization as a kind of delay in our thesis, we integrate synchronization into delay to create delay modeling. We accord with our analyses of total upload bandwidth requirement for single-tree and multiple-tree streaming to do bandwidth modeling and realize their tree-based formations. Single-tree formation can be successfully constructed based on the total maximum number of receivers for each participant streaming. Multiple-tree can be constructed successfully because the total upload bandwidth is sufficient for multiple-tree streaming. Our delay models depend on the tree-based formations for design. We do delay modeling both with and without synchronization.
Moreover, in order to verify the reasonability of our analytical model and proposed algorithm, we use a series of simulations. Furthermore, for single-tree and multiple-tree, we make the comparison between results of analyses and simulations to conclude what conditions of metrics have better performance. Based on conditions of performance metrics, we can determine which (single-tree or multiple-tree) is better suited for transmitting streams.
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