Reducing bandwidth requirement for delivering video over wide area networks with proxy server

Due to the high bandwidth requirements and rate variability of compressed video, delivering video across wide area networks (WANs) is a challenging issue. Proxy servers are used to cache passing data to reduce the congestion and to improve the client access time on the Internet. In this paper, we investigate ways to store or stage partial video in the proxy servers to reduce the network bandwidth requirements over WANs. A client needs to access a portion of the video from a proxy server over a local area network (LAN), and the rest of it from a central server across the WAN. Therefore, the client buffer requirements and video synchronization need to be considered. We study the tradeoffs between the client buffer, the storage requirements of the proxy server and the required rate for video transport over the WAN. Given a video delivery rate for the WAN, we propose several frame-staging selection algorithms to decide which frames of the video are to be stored in the proxy server. A scheme called the Chunk algorithm, which partitions a video into different segments (frame chunks), with alternating chunks being stored in the proxy server, offers the best tradeoff.