Patent ID: 8559814

Claim:
A carrier-side optical communication device that is connected to a plurality of subscriber-side optical communication devices and that performs two-way communication with the subscriber-side optical communication devices in an optical communication system, the carrier-side optical communication device comprising: a packet monitor that monitors the presence or absence of a packet that is transmitted from the subscriber-side optical communication devices; a packet discriminator that discriminates between a delay measurement packet and a packet other than the delay measurement packet among packets transmitted from the subscriber-side optical communication devices; a power-saving mode flag generator that generates a power-saving mode flag for the carrier-side optical communication device in accordance with the presence or absence of the packet that is monitored by the packet monitor and a discrimination result by the packet discriminator; and a power-saving controller that controls saving of power of the carrier-side optical communication device in accordance with the power-saving mode flag generated by the power-saving mode flag generator, wherein when the packet discriminator determines that a packet transmitted from the subscriber-side optical communication devices is the delay measurement packet, the power-saving mode flag generator generates a power-saving mode flag so that the power-saving controller does not control the saving of power.