Abstract: A center-to-end type information service system utilizing the public telephone networks that are fundamental communication media of nation-wide scale is disclosed in which desired information is requested from the terminal side to the center by means of a telephone set or simplified keyboard and then delivered to and received by a TV receiver. A part of the center functions is transferred together with the exchange function to a subcenter located near the terminal. Thus, the length of transmission path connecting the center to terminals becomes shorter and the cost of the whole system can be cut down. A simplified character generator is provided in the subcenter, thereby diminishing traffic of the video network.

Abstract: A video/audio transmission system for sending video and audio information from video and audio files of a center to a subscriber through a subscriber's junction line is disclosed in which at least one subcenter having a video/audio buffer memory, an exchange and the like is disposed near to the subscriber to reduce the number of repeaters arranged on the subscribers junction line, and in which the video and audio information is transmitted from the center to the sub-center in a time division multiplex fashion to reduce the number of transmission lines between the center and the sub-center.

Abstract: A video/audio transmission system for sending video and audio information from the video and audio files of a center to a subscriber through a subscriber's junction line is disclosed in which at least one subcenter is disposed near to the subscriber to reduce the number of repeaters arranged on the subscriber's junction line. The subcenters can include a video/audio buffer memory, and exchange and other related circuits. The transmission lines for sending the video and audio information from the center to the sub-center are spatially divided into a plurality of groups in accordance with the sort of the video and audio information being sent, and further the information is time-divisionally transmitted at each group.

Abstract: A center-to-end type information service system utilizing the public telephone networks that are fundamental communication media of nation-wide scale is disclosed in which desired information is requested from the terminal side to the center by means of a telephone set or simplified keyboard and then delivered to and received by a TV receiver. A part of the center functions is transferred together with the exchange function to a subcenter located near the terminal. Thus, the length of transmission path connecting the center to terminals becomes shorter and the cost of the whole system can be cut down.