Optical line terminal, optical access network system, and optical communication method

An optical line terminal on an operator side to operate a plurality of virtual dynamic bandwidth allocation units to, according to a transmission request transmitted by an optical network unit on a subscriber side, calculate bandwidth to be allocated to a transmission source of the transmission request and output a transmission grant, the optical line terminal comprising:

• service control circuitry to generate the plurality of virtual dynamic bandwidth allocation units according to service requests;
• transfer control circuitry to, when receiving the transmission request, select the virtual dynamic bandwidth allocation unit that is a transfer destination of the received transmission request, based on transfer rule information indicating a correspondence relationship between the transmission source of the transmission request and the virtual dynamic bandwidth allocation unit that is the transfer destination, and transfer the transmission request to the selected virtual dynamic bandwidth allocation unit;
• and
• aggregation control circuitry to aggregate the transmission grants output by the virtual dynamic bandwidth allocation units, based on aggregation rule information indicating correspondence relationships between destinations of the transmission grants and the virtual dynamic bandwidth allocation units that are possibly transmission sources of the transmission grants.