A communication network system having a high-ranked network and low-ranked networks, an exchange port for connecting the high-ranking network and a low-ranked network, microcomputers for controlling connection between a low-ranking network transmission line and a high-level network transmission line, and communication transceivers which is connected to the transmission line of a low-rank network and the transmission line of the high-order network

摘要

A communication network system (1) comprising: - a high-ranked network (N1) in which a plurality of ports (2-5) having a plurality of exchange ports (2, 5) communicate with each other via a first communication line (8) by applying a first communication protocol wherein the first communication protocol sets each fixed length communication period a fixed allocation period and a dynamic allocation period, communication zones are fixedly assigned to the respective terminals in each fixed allocation period, and communication zones are changeably allocated to the respective terminals in each dynamic allocation period; and - a plurality of low-ranked networks (N2, N3) connected to the high-level network (N1) through the respective exchange ports (2, 5), and a plurality of low-rank (6, 7) connection ports in each low-level network (N2 , N3) communicate with each other via a second communication line (91, 92) by applying a second communication protocol different from the first communication protocol, wherein the exchange ports (2, 5) define at least a portion of each dynamic allocation period as the transmission period and the second communication lines (91 , 92) of the low-rank networks (N2, N3) during each transmission period to the first communication line (8) of the high-order network (N1) to connect it to each low-level connection port (6, 7) of each low-level network (N2, N3) during the transmission period over the high-order network (N1) with the connection terminals of low rank (6, 7) of the other low-level networks (N2, N3) by using the second communication protocol without any protocol conversion.