Information exchange network system, information exchange central control unit and information exchange means used in the system, information transmission method and modulation method

摘要

An information communication network system comprises a plurality of information communication devices (70) to which at least one information device (80) is connected, tree shaped or star shaped bidirectional transmission lines (60) for connecting the information communication devices (70), and at least one central information communication control device (32) located upstream of the bidirectional transmission lines (60). The central information communication control device (32) includes access control information generating means (124) for detecting an information communication access state on upward transmission lines in the bidirectional transmission lines (60) and generating information communication access control information for controlling the upward transmission lines, and downward transmission means (153) for transmitting the information communication access control information, produced by the access control information generating means (124), to downward transmission lines in the bidirectional transmission lines (60) toward the at least one information communication device (70). Each information communication device (70) includes access control information receiving means (230) for receiving information communication access control information transmitted from the central information communication control device (32), and information communication control means (206) for controlling information communication processing of the local information communication device based on the information communication access control information received by the access control information receiving means (230). IMAGE