| 摘要 |
PURPOSE:To obtain a point-to-multi-point optical transmission system in which the reliability of communication is enhanced by a subscriber side transmitter not adopting a redundant configuration. CONSTITUTION:The 1:n two-way communication is conducted among a station side transmitter 100 and plural subscriber side transmitters which are opposite to each other through optical transmission media duplicate in two systems. In this case, a 1:2 branch photocoupler 700 is provided respectively to each of simplex subscriber side transmitters 301, 401 not adopting a redundant configuration and optical transmission reception circuits 310,410 are connected to branch parts 211, 221 or 212, 222 of the optical transmission media through the coupler. That is, the optical transmission reception circuits 310, 410 being components of both 0 and 1 systems. Thus, even when a system is selected, the communication using the simplex subscriber side transmitters 301, 401 is continued. |
