| 摘要 |
PROBLEM TO BE SOLVED: To provide flexibility against a fault of a host node by dividing an optical distribution stage into a plurality of groups and configuring the distributer such a way that the division groups mutually compensate the input from an optical switch given to the division groups. SOLUTION: The distributer is configured to be multi-stage (e.g. 3 stages) in a way of a tree of redundant configuration of 2×2 optical switches and 1×N photocouplers. A 3rd stage is divided equally into two groups, and each of the 2×2 optical switches S being equally divided receives every output of the 1×4 photocouplers C. In the 2nd stage, one of the group divided at the 3rd stage into two is divided into two groups again, outputs from the 1×4 photocouplers C are given to the input of the 2×2 optical switches S so as to compensate other groups. In the 1st stage, the 1×4 photocouplers C and the 2×2 optical switches S are connected to be compensated with each other. The 2×2 optical switch S acts like a 1×2 photocoupler when one of input signals is in error and provides an output of a normal input to each output equally. Thus, any normal route is enough for the input from a terminal IN. |
