STATION SIDE DEVICE, PON OPTICAL COMMUNICATION SYSTEM, AND POWER CONSUMPTION CONTROL METHOD

PROBLEM TO BE SOLVED: To implement low power consumption of a home side device ONU by determining traffic amount of information from a station side device OLT to the home side device ONU.SOLUTION: A station side device OLT: observes downstream traffic amount of each home side device ONU; transmits a power saving mode setting frame describing power saving mode time TPS during which the home side device ONU is in a power saving state to the home side device ONU whose average traffic amount in the past is lower than a prescribed threshold; and controls a transmission interval of a control frame for upstream band allocation to be transmitted to the home side device ONU so that the transmission interval is longer than that of the home side device ONU in the state which is not the power saving state. A reception part of the home side device ONU sets the own reception part into the power saving mode during the power saving mode time TPS described in the power saving mode setting frame, when receiving the power saving mode setting frame addressed to its own station from the station side device OLT.