There are three types of communication; one to one communcation multipoint communication(teleconference) and center-end communication. Although teleconference has been expected as a powerful means which would make social activties more effecient, it is not so popular compared with Other two types of communication because it needs high level communication techniques and sophisticated human interface. But recent technological progress of variety fields is making it realistic. In this paper, perspective of teleconferencigng techniques development is presented.
In accordance with wide variety of situations which video codecs are applied to, many kinds of codecs have been developed with different design philosophies. This paper outlines objectives, coding algorithms, hardware architectures, and coding performances of our four video codecs; 1. compact codec for LAN, 2. medium rate codec for primary or sub-primary rate transmission, 3. low rate codec for ISDN use, and 4,. HDTV codec for LAN and BB-ISDN.
We have been studying Audio Graphic Conference(AGO service and its protocol based on existing telematic services and protocols. This paper firstly introduces a new Application Service Element, called AGSE, to cover the basic AGC facilities in OSI together with the AGC protocol architecture. Secondary, the basic functionalities ofMCU( Multi-point control Unit) which is used for multi-point connection are discussed. To be concrete, the document and voice information delivery method, token control for voice information and data channel control on 64kbps frame are proposed.