| 摘要 |
PROBLEM TO BE SOLVED: To provide the optical network system in which not only number of connectable nodes and a transmission distance are extended but also a system parameter is easily changed. SOLUTION: All carriers from a node 1-1 remotest from a center 2 are sent at the same level and they are received by a center 2 and a carrier level detection circuit 4 measures the level of the carriers. A microprocessor unit 5 assigns a carrier frequency with a larger level deviation than the carrier of a pilot signal as a carrier frequency of a nose arranged closer to the center 2 based on the measurement result and generates carrier control data used to control the carrier level constant. A control system electro-optic converter 6 applies electro-optic conversion to a signal where noise service data are multiplexed on the carrier control data and sends the resulting signal to an outgoing system optical fiber. Nodes 1-1 to 1-N controls the carrier frequency and the carrier level of an internal FM modulator based on the received control data. |
