| 摘要 |
PROBLEM TO BE SOLVED: To simplify a communication procedure, to eliminate a pressure to an optical channel and to perform prompt half-duplex optical communication. SOLUTION: In an optical radio communication system, optical signals are transmitted and received by half-duplex optical communication between plural slave units and a master unit. The master unit receives frame data F from the slave unit to which an optical channel use permission PM is supplied last, then transmits the optical channel use permission PM to the slave unit, stands by for fixed time and transmits optical channel free signals SP to the other plural slave units when a new frame F is not transmitted from the slave unit within the fixed time. In the meantime, the slave unit transmits the frame data F to the master unit, then stands by for the fixed time and transmits new frame data F as needed to the master unit at the time of detecting optical channel use permission signals PM from the master unit within the fixed time. |
