An Architecture for Proxy-Assisted Periodic Broadcast for Large Scale Video Streaming

Date of Submission: 
September 17, 2003
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Many multimedia applications rely on video streaming techniques. However, large scale video delivery is still very challenging since it requires a large amount of resources such as storage space, network bandwidth and I/Obandwidth. In this paper we propose a proxy-assisted periodic broadcast architecture for video delivery to a large number of clients over the Internet. Our video delivery technique is based on a combination of periodic broadcast by central server and proxy server caching. A proxy server caches either part or the whole video based on the video popularity. We assume that each proxy server may have different capability and that the video popularity in each community can be different and dynamically changing. A video stored in the central server is partitioned into two parts, a server prefix and a server suffix, based onthe aggregated demand for the video from all communities. In principle, the server prefix is delivered by unicast and the server suffix is delivered by periodic broadcast. Such an approach allows to significantly reduce the required I/O bandwidth at a server. The combination of proxy prefix and server prefix defines a wide spectrum of different videodelivery modes. The transmission of a video can be either partially unicast or partially period broadcast depending on the relationship between proxy prefix and server prefix. We further define and solve the optimization problems for proxy prefix selection and server prefixselection in order to minimize the total resource requirements. Performance of our system is evaluated through a number of tests.