WAVELENGTH SPLIT TYPE OPTICAL CHANNEL

摘要

PROBLEM TO BE SOLVED: To enhance the reliability against a failure by adopting a redundancy configuration where no switch back from a standby system to an active system is required when a fault is recovered and to allow the channel to have provision for increase/decrease in input output transmission channels flexibly by using a confluent switch for the switching. SOLUTION: (N+H) sets of optical distributers 21, (N+H) sets of confluent switches 31 that distribute signal lights into N directions depending on the wavelength bands and (N+H) sets of optical combiners 41 are connected to N input optical transmission lines 11 via an optical spatial switch 61 providing outputs of (N+H) so as to provide H-sets of standby systems. When any of the confluent switches 31 is faulty, the setting of the optical spatial switch 61 is changed to select any of the H sets of the standby system to avoid the failure and no switch back after restoration is conducted to avoid interruption of communication. Since the confluent switches 31 are dependent on the circuit scale and number of optical transmission lines, the required minimum configuration is enough to cope with the increase/decrease in the input output optical transmission line number N, and the extension performance with respect to the increase in traffic is enhanced.