A multi-server video-on-demand system with arbitrary-rate playback support

In this paper, we propose a multi-server design for video-on-demand (VoD) s ystems that can provide different quality of service (QoS) guarantees by ar bitrary-rate video playback. This design chooses a symmetric architecture t hat consists of a set of identically configured servers and supports arbitr ary rates of video playback required by different clients in the following way. The playback requirements requested from all clients are first sent to the master server. If the master server decides to accept a new client, it distributes the task of the new client to all the servers, including itsel f. Through the pre-processing of the video streams, we can map the data of each frame of every video to a frame map. This frame map indicates whether a frame should be sent to the client at a given frame rate. In our multi-se rver design for a VoD system, using these frame maps and a suitable transmi ssion schedule, a client can demand to play any video, at any playback rate and at any time. Furthermore, the VoD system provides a high degree of fau lt tolerance. This design not only can tolerate the failure of one or more servers, but also requires relatively small bandwidth capability or reserva tion for fault tolerance. In addition, this multi-server design can effecti vely overcome the hot spot problem of popular videos and keep the load bala nced at the same time. Finally, we discuss how to generalize the proposed m ethod for a large-scale VoD system with heterogeneous architecture. (C) 200 0 Elsevier Science Inc. All rights reserved.