Chinese Journal of Computers   Full Text
Title	Hierarchical Total Utility Modeling and Solution for Large-Scale Video Multicast System
Authors	WANG Hui SHA Ji-Chang JIANG Zhi-Hong ZHANG Xin
Address	(College of Information System and Management, National University of Defense Technology, Changsha 410073)
Year	2007
Issue	No.12(2115—2123)
Abstract &   Background	Abstract To effectively analyze and evaluate the adaptive methods for large-scale video multicast system, this paper first abstractly describe the maximum problem of the total utility for large-scale video multicast system. Since the centralized solution for the maximum problem has disadvantages of single-node failure, feedback implosion, and bad real-time performance, a hierarchical decomposition method based on bottleneck link is presented in this paper, and the hierarchical total utility model for large-scale video multicast is also given. Then, OptUtility, an extendable, hierarchical proxy-based distributed solution, is proposed, by which we can figure out optimally the bandwidth allocation of each session, the layering number, and the rate of each layer in all hierarchical proxies. Analysis of computational complexity and experimental results prove the proposed distributed method to be of low complexity, easy in implementation, and well performed in real time. keywords large-scale video multicast; total utility; hierarchical proxy; distributed solution; optimal performance background With the popularization of access to broadband networks, the demand for network video services is on the great increase in recent years. Video multicast, the particular network video service apt at multipoint data delivery, has been widely applied to distance learning, distributed video conference, digital video surveillance and real-time video distribution. In accordance with the enlarging of video multicast application scale, the capability of video multicast networks and receivers varies greatly. Video multicast has suffered criticism on its performance, such as the complexity of management, the difficulty of Quality of Service(QoS) guarantee, etc. In order to solve these problems, the academic and industrial communities have concerned on adaptive video multicast(AVM) for years, but there are still many theoretical and practical problems left to be resolved, especially for large-scale video multicast applications. This paper studies the optimization for large-scale AVM to make it apply in heterogeneous environments. In this paper, the authors first classify and analyze several typical AVM schemes. It is found that most of these schemes take small-scale video multicast applications as the backgrounds, and they only improve the local performance metrics. To extend the results, a total system utility model for AVM systems is presented in this thesis. And an extendable, hierarchically distributed solution is also proposed, by which we can figure out optimally the bandwidth, the layer number, and the layer rates for each session. The proposed method can handle the problems of feedback implosion, single-node failure, and bad real-time performance caused by centralized adaptive control and decision in large-scale AVM applications. Experimental results and analysis of computational complexity prove the proposed distributed method to be of low complexity, easy in implementation, and well performed in real time.