Screen-Based Multimedia Telephony
Paul E. Crouch, Jorge S. Rodriguez, William C. Schwartz · AT&T Technical Journal · 1995
Today, telephone users are already realizing the multimedia dream as the AT&T VideoPhone 2500, Picasso® and Vistium™ products are introduced into consumer's homes and onto office desktops. A major, common element of these products is a display screen that provides a visual perspective. In addition, end-users now have a choice about what they can view at any given instant. The quality of this choice depends on the product itself, the feature set being used, and the bit rate of the telephone transmission medium. This bit rate varies from the very low speeds of the public switched telephone network (PSTN) to the higher speeds of basic-rate ISDN and ultimately to the very high speeds of broadband and asynchronous transfer mode technologies. This paper discusses these factors, the overall architecture of the three AT&T products, as well as their rich sets of features. In addition, key markets and applications are highlighted.