Research On Proxy Caching Algorithm For Mobile Streaming Media Based On Segmentation And Popularity

Mobile streaming media technology is the combination of the mobile network technology and streaming technology. Visiting the multimedia objects via streaming technology will bring network transmission flows with great rate and long time. The proxy caching technology can effectively reduce the transmission of streaming media content. Caching algorithm is the key part.3G network is the developing direction of mobile networks, in the streaming media transmission system of 3G, the mobile terminal's resources will be extremely limited comparing to Internet's client terminal. So in the applications of 3G streaming media, the proxy server's caching algorithm will be more important.Nowdays the research of main caching algorithm are all based on Internet. And in the research of popularity, users'visiting behavioral characteristics to streaming media is lacking of quantitive analysis. The mobile streaming media caching technology based on 3G WCDMA network is studied and a new mobile streaming media caching technology based on segmentation and popularity is proposed in this essay.Contraposing users'visiting behavioral characteristics to streaming media, The Zipf-like distribution model under K transformation is successfully introduced by describing through the collecting and analysising the records of the actual users'access log. The new model improved the original one obviously. For the fluctuation of media files'popularity made a double breakpoint estimating function which can account the internal popularity of the media's segments more actually.The segmenting issues are not clear in the existing two-layer 3G mobile streaming media proxy caching technology. For these issues, this paper proposed a method based on two breakpoint estimating function and Zipf-like model under K transformation. It can actually divide a media file to prefix, inffix and suffix so that the dividing stategy becomes complete.The existing two-layer mobile streaming media proxy servers technology hasn't researched the caching algorithms, this paper proposed two-tier caching algorithm based on the 3GPP two-layer proxy framework and the proposed segmentation mechanism. It abstracted two different cache replacing function considering of the different characteristics of the user edge proxy server and the centre proxy server, it also considered the the different influencing factors of the caching value to media files.The algorithm includes UECP caching algorithm and CCP algorithm, each one includes complete caching access control strategy and cache replacement mechanism to form a complete two-tier caching mechanism.Experimental results show that the proposed algorithms including the UECP caching algorithm and the CCP caching algorithm obviously have better caching performance than the SCU algorithm and LFU algorithm in the existing two-layer proxy framework.