DEMAND ACCESS INFORMATION SERVICE SYSTEM, INFORMATION DELIVERY EQUIPMENT USED FOR IT, RELAY DISTRIBUTION EQUIPMENT AND USER TERMINAL EQUIPMENT

摘要

PROBLEM TO BE SOLVED: To provide the system from which similar advantages are obtained to those in an intercast system in the demand access information service. SOLUTION: The system has an information server 6, a substitute server 13 linked with the information server 6 via a broadcast channel 8 and a 2-way communication line 9, and plural terminal equipments 17 linked to the substitute server 13. The information server 6 sends data with at least identification information added to them via the broadcast channel 8 according to a predetermined program table, the substitute server 13 receives the broadcast data according to a predetermined reception schedule table and stores the data to a storage device 14 while updating its contents in a retrieval enable way based on the identification information. When data by a demand access from an optional terminal equipment 17 are in existence in the storage device 14 of the substitute server 13, the substitute server 13 delivers the data and when not in existence, the information server 6 transfers the data to the substitute server 13, which delivers the data, and the data are stored in the storage device 14 of the substitute server 13 in a retrieval enable way.