Wavelength division multiplexing transmission system, wavelength division multiplexing transmission apparatus and method for controlling wavelength division multiplexing transmission apparatus

A wavelength division multiplexing transmission system having terminal stations for entering/delivering an optical signal and performing wavelength division multiplexing and transmission of said optical signal,

• wherein a signal transmission system comprising said terminal stations has a redundant configuration comprising an active system and a standby system,
• wherein said input/output means for the optical signal is provided on both said active system and said standby system, on the side of said active system of said terminal stations.

A wavelength division multiplexing transmission apparatus comprising input/output terminal stations for an optical signal, and performing wavelength division multiplexing and transmission of said optical signal,

• wherein a signal transmission system comprising said terminal stations has a redundant configuration comprising an active system station and a standby system station,
• wherein said input/output means for an optical signal to be transmitted through said active system or said standby system is provided on both said active system and said standby system, on the side of said active system of said terminal stations.

A method for controlling a wavelength division multiplexing transmission apparatus comprising input/output terminal stations for an optical signal, and performing wavelength division multiplexing and transmission of said optical signal, comprising steps of:

• rendering a signal transmission system comprising said terminal stations a redundant configuration comprising an active system and a standby system, and providing said input/output means for the optical signal on both said active system and said standby system, on the side of said active system of said terminal station, and
• controlling the clock synchronization of the optical signal transmission on the said active system or said standby system, based on the prescribed control information set based on said redundant configuration, through said input/output means.