Passive optical network system, optical line terminal, and optical network unit

An optical line terminal in a passive optical network system which comprises the optical line terminal, an optical splitter, an optical fiber, and a plurality of optical network units connected to the optical line terminal through the optical splitter, and in which the optical line terminal and the optical network units communicate with each other by wavelength division multiplexing,

• wherein a first wavelength which is received in common by the respective optical network units is previously determined, and the optical line terminal assigns a second wavelength for communication between the optical line terminal and each of the optical network units to each of the optical network units among a plurality of wavelengths which are different from the first wavelength,
• wherein the optical line terminal comprises:
• a plurality of transmitters each of which has a light source different from each other in wavelength;
• a plurality of receivers to receive signals of a plurality of wavelengths;
• a wavelength management table to manage, for each of identifiers of the optical network units, second wavelength information assigned for communication with each of the optical network units;
• and
• a control unit to transmit a control message for assigning the second wavelength to the optical network unit through one of the transmitters,
• wherein one of the transmitters is previously set to the first wavelength common to one of receivers of the optical network units, and
• wherein data of broadcast communication to the optical network units is transmitted by the first wavelength, and/or the control message including second wavelength information not assigned to other communications on the basis of the wavelength management table is transmitted to the optical network unit by the first wavelength, and the second wavelength is assigned to the optical network unit.

An optical network unit in a passive optical network system which comprises an optical line terminal, an optical splitter, an optical fiber, and a plurality of optical network units connected to the optical line terminal through the optical splitter, and in which the optical line terminal and the optical network units communicate with each other by wavelength division multiplexing,

• wherein a first wavelength which is received in common by the respective optical network units is previously determined, and a second wavelength for communication between the optical line terminal and the optical network unit itself is assigned among a plurality of wavelengths which are different from the first wavelength,
• wherein the optical network unit comprise:
• two or three or more receivers in which wavelengths different from each other are set and which respectively receive signals of the set wavelengths;
• one or a plurality of transmitters to transmit signals of set wavelengths;
• a wavelength control unit to variably control transmission wavelengths of the transmitters and reception wavelengths of the receivers in accordance with stored wavelength information;
• and
• a control unit to receive a control message for assigning the second wavelength from the optical line terminal through the receiver and to store the second wavelength information assigned to the optical network unit itself into the wavelength control unit,
• wherein the first wavelength common to one of transmitters of the optical line terminal is previously set in one of the receivers, and
• wherein data of broadcast communication from the optical line terminal is received by the first wavelength, and/or the control message including second wavelength information not assigned to other communications is received from the optical line terminal by the first wavelength, and the second wavelength is assigned.

A passive optical network system which comprises an optical line terminal, an optical splitter, an optical fiber, and a plurality of optical network units connected to the optical line terminal through the optical splitter, and in which the optical line terminal and the optical network units communicate with each other by wavelength division multiplexing,

• wherein the optical line terminal includes:
• a first transmitter to transmit a signal of a previously determined first wavelength;
• a plurality of second transmitters to transmit signals of a plurality of second wavelengths assigned to the respective optical network units;
• a plurality of first receivers to receive signals of a plurality of third wavelengths from the respective optical network units;
• and
• a distribution unit which identifies whether a packet received from a network is a packet of broadcast communication or a packet of point-to-point communication with the optical network unit, outputs, when it is the packet of the broadcast communication, the packet to the first transmitter, and outputs, when it is the packet of the point-to-point communication with the optical network unit, the packet to the second transmitter of the second wavelength assigned to the optical network unit of the destination of the packet,
• wherein each of the plurality of optical network units includes:
• a second receiver to receive a signal of the first wavelength;
• a third receiver to receive a signal of the second wavelength assigned to the optical network unit itself;
• and
• a third transmitter to transmit a signal of the third wavelength assigned to the optical network unit itself, and
• wherein the packet of the broadcast communication transmitted from the first transmitter by the first wavelength is branched by the optical splitter and is received by the second receiver of each of the optical network units, and the packet of the point-to-point communication with the optical network unit transmitted from the second transmitter by the second wavelength is received by the third receiver of a desired optical network unit.