scheme depending on the degree to which VoD services make use of user interactivity have been proposed in the This paper addresses the problem of organizing resources in large video-on-demand (VoD) front-end servers, so a large literature [1].
collection of movie titles and concurrent channels can be made
The operation of a VoD server comprises two steps. available at the lowest possible cost, and with the highest admis-First, upon receiving a request, the server must be able to sion quality of service (QoS). Coarse-grained striping (CGS) in reserve resources and decide if the request can be honored. disk arrays is shown to be a viable candidate due to its cost-This is the program scheduling phase, in which the VoD effective storage utilization and low admission latency. We server uses an admission control algorithm to decide when study the feasibility of storage organizations in which disks are to start program transmission, based on such constraints partitioned into several clusters to lessen service disruptions as the available capacity of the movie archive on disks or during reconfigurations. In parallel with this, we present an disk arrays in compressed format. Once a service has been algorithm for optimal video allocation across clusters, and show scheduled, run-time operation of the VoD server will enthat high service availability can be achieved cost-effectively sure continuous and seamless playout by retrieving in realwith minor side-effects on customers' admission latency. We time and delivering a stream of compressed video data.
also identify specific situations when storing one movie per disk
Video data is then decompressed by the customer's premperforms acceptably well. Finally, we show that full-fledged ise equipment (CPE), modulated to a conventional televi-VCR functionality can be provided at reasonable cost.