The Dynamic Cache Of Proxy For Streaming Media

In the age of digital information that we have entered, with the rapid development and widespread application of Internet technology, more than 50% of Internet data is stored in the formal for streaming media, whose application system, international standard and basic research have become one of the focuses of the domains for current industry and science research. To address the conflict between wide application of streaming media and limited Internet's resources are one of challenging projects. This thesis carries out some research on the proxy cache for streaming media; proposes algorithm for dynamic ache and applies it to the prefix cache, segment-based cache and video multicast; improves the caching policy in every transmitting project; sets up mathematic model; presents quantitative analysis of algorithm for dynamic cache and evaluates efficiency of the algorithms of dynamic cache, segment-based cache, prefix cache and full cache and finally gives a further description of the high-powered dynamic cache. Both dynamic cache and segment-based cache can improve high-powered proxy cache for streaming media. Thus this thesis presents the relationship of the distribution between the segmented caching and dynamic caching algorithm. This thesis applies the algorithm of dynamic cache to patching and batching, and further, present the algorithm of batched patching using dynamic cache is optimal effective.The main contributions and results included in thesis are as follow:Firstly, a detailed of the literature review of the transmitting policy of proxy cache for streaming media is described. This literature review begins with the Internet-based proxy cache, and then introduces all kinds of algorithms of the transmitting policy of streaming media and highlights the research results of streaming scheduling policy in the transmitting process of streaming media, and illustrates the current situation, the applied field, the mathematic model, and advantage and disadvantage of the patching algorithm and the batching algorithm. All above this technique serve as the basis of further research.Secondly, the thesis researches on the high-powered technique of prefix cache for streaming media. This section, on the basis of prefix cache, puts forward three kinds of algorithms of dynamic cache: window-based, quantity-based and effect-based algorithm, which are proved to be able to improve the efficiency of proxy cache, when applied respectively to unicast suffix batching, unicast patching, multicast patching, streaming merging, batched patching and other transmitting projects. In accordance with clients' request, it sets up mathematic models for various transmitting projects and presents quantitative analysis of how dynamic cache improves the efficiency of steaming media in every transmitting project.Thirdly, the thesis researches on the algorithms of dynamic cache based on segmented cache. Segmented cache is one of the high-powered caching methods, the caching size of which is allocated in accordance with request frequency of clients, and both segmented cache and prefix cache are cached in the proxy cache. Based on the segment-based cache the dynamic cache further enhances the efficiency of the proxy cache, by applying the three dynamic caching algorithms of window-based, quantity-based and effect-based to segment-based unicast suffix batching, unicast patching, multicast patching, streaming media and batched patching and other transmitting projects. This section also presents quantitative analysis of how dynamic caching algorithm improves the efficiency of streaming media system in various segment-based transmitting projects, by setting up the mathematic analysis model for various transmitting projects. It also analyzes how dynamic cache, which can be divided into the following two kinds of application forms: dynamic caching window and dynamic cache improves the caching efficiency. Both segment-based cache and dynamic cache can improve the efficiency of proxy cache, and their distributive relationship is illustrated...