Patent ID: 8306004

Claim:
A communication network system, comprising: a high-ranking network in which a plurality of terminals containing a plurality of interchange terminals communicate with one another through a first communication line by employing a first communication protocol, the first communication protocol setting a fixed allocation period and a dynamic allocation period every communication period of a fixed length, communication zones being fixedly allocated to the respective terminals in each fixed allocation period, communication zones being changeably allocated to the respective terminals in each dynamic allocation period; and a plurality of low-ranking networks connected with the high-ranking network through the respective interchange terminals, a plurality of low-ranking connection terminals in each low-ranking network communicating with one another through a second communication line by employing a second communication protocol different from the first communication protocol, wherein the interchange terminals set at least a part of each dynamic allocation period as a pass-through period and connect the second communication lines of the low-ranking networks with the first communication line of the high-ranking network during each pass-through period to enable each low-ranking connection terminal of each low-ranking network to communicate with the low-ranking connection terminals of the other low-ranking networks through the high-ranking network during the pass-through period by employing the second communication protocol without any protocol conversion.