Power saving control method and node device in optical communication network

An optical communication network system in which a plurality of node devices are connected through a plurality of optical fiber lines,

• wherein each of the node devices includes a plurality of optical transceivers on which a plurality of standby modes can be selectively set, the standby modes including a first standby mode in which a startup period is shorter than an allowable interruption period in the optical communication system and a first amount of power is consumed during standby, and a second standby mode in which the startup period is longer than the allowable interruption period and a second amount of power that is smaller than the first amount of power is consumed during standby,
• the system comprising:
• a network controller which sets a predetermined number of optical transceivers that should stand by in the first standby mode for each of the node devices and controls communication performed by the node devices;
• and
• a power consumption controller which, based on usage states of the plurality of optical transceivers and the predetermined number of optical transceivers that should stand by in the first standby mode, dynamically allocates the plurality of standby modes to the plurality of optical transceivers so that a total amount of power consumption of a relevant node device will be smaller.