Video-on-demand System Architecture Using An Optical Mass Storage System

Video-on-demand (VOD) systems, using the communication network to send requested video programs from video storage centers to terminals, are applicable to services such as movies, commodities-guides, and video museums. Against the background of digitization of communications and progress in video compression techniques, digital VOD has recently been proposed [1,2]. The volume of digital video data, however, is enormous: about 1.1 GB per 100 minutes even at the 1.5 Mbps of the IS0 MPEG standard. The storage of many video programs therefore requires an optical mass storage system (MSS) [3], the use of which is associated with the following problems: (1)Response is slow because of the time required for mounting a disk. (2)When a video program divided into several surfaces or disks, the playback is interrupted while turning over or changing disks, and it is difficult to implement visual search. (3)Waiting time is long when all drives are in use. This paper proposes solutions for these problems and verifies their effectiveness in trial VOD system.