Interactive television system with cd-rom at each subscriber site

摘要

In an interactive TV system, information which can be left relatively unchanged for substantial periods of time is stored in CD-ROM at each subscriber site. Information which changes between CD-ROM replacements is transmitted from the head end to the subscriber sites in a recurring, or recycling data stream. Individual subscriber sites select the information they desire from the data stream and reproduce it, together with any related information stored in CD-ROM. Transactions based on the so-reproduced information are activated by telephone line transmissions from the subscriber sites.