| 摘要 |
PURPOSE:To reduce the cost and make the operation efficient, by controlling the start of the transmitting operation of each terminal by the control signal from an optical star repeater to perform transmissions of terminals in time division. CONSTITUTION:First, a control signal S0 is transmitted from an optical star repeater SR toward terminals H1-Hn. After the end of the control signal S0, each of terminals H1-Hn is set to the transmittable state only for a certain time. A contention detector 1 starts the detecting operation simultaneously; and if the contention state is not detected, the terminal H1 continues the transmission and reports the end of the transmission at a certain transmission stop time after the end of one cycle, and the control signal S0 is transmitted again from the optical star repeater SR to start the next communication cycle. When the contention of transmission occurs between plural terminals H1 and Hx, the contention detector 1 detects it to inhibit the repeating operation of the optical star repeater SR side, and the transmission from both terminals H1 and Hx is interrupted. The control signal S0 is issued again after a certain time to perform the transmitting operation newly. |
