Equipment and method for band allocation

A bandwidth allocation method in an optical line terminal which allocates bandwidth for data to be transmitted from a plurality of optical network units through an optical splitter, said method comprising:

• an output request receiving step that receives an output request for requesting bandwidth allocation to the data from the respective optical network units;
• a bandwidth allocation processing step that performs bandwidth allocation by a plurality of bandwidth allocation units, each bandwidth allocation unit is provided with corresponding to the optical network unit for performing bandwidth allocation processing in accordance with the output request for the data to be transmitted from the corresponding optical network unit, and each of bandwidth allocation units are connected to one another in a ring to perform the bandwidth allocation processing one by one for corresponding optical network unit;
• and
• a sending back step that sends back a signal sending permission, which has been output from the bandwidth allocation unit that has performed the last bandwidth allocation processing in the ring connection, to the respective optical network units for specifying bandwidth to be allowed for transmitting the data in each service cycle as a unit period for the data transmission,
• wherein, said bandwidth allocation processing step includes a bandwidth allocation unit specifying step that specifies the bandwidth allocation unit to perform the first bandwidth allocation processing in the ring connection by shifting the bandwidth allocation unit one by one for each of the service cycles.