Multimedia integrated switching architecture for visual information retrieval systems
Hiroaki Sakamoto, Kazutoshi Nishimura, Yutaka Ishibashi, Hirotaka Nakano · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1993
Advanced visual information retrieval systems supporting both video and images need to have flexible system design so that their system configurations can easily be enhanced. It is therefore desirable to separate the features of a central system into three parts: storage servers, communication servers, and a back-end network that combines these. In this architecture, unscheduled arrivals of data blocks at a back-end network cause two problems: unacceptable fluctuation of video frames and overly long delays of image transfer. To solve these problems, we have designed a new multimedia integrated switching system (MISS) that uses a fully connected crossbar switch to combine servers. MISS treats a time interval of a few hundred microseconds (called a `time-slot') as the basic unit of data block transfer, and allocates appropriate time-slots to all transfer requests in order to simultaneously meet the requirements for each kind of visual information transfer. According to simulation results and estimates based on queuing theory, MISS greatly reduces video frame fluctuation and halves the average image transfer delay. These effects have been confirmed in an experimental visual communication system built around MISS. This system supports JPEG compressed video and images, and six terminals can simultaneously retrieve visual information through an FDDI network.