Patent ID: 11949460
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 4:
5. An optical line terminal comprising:
an optical transmitting/receiving unit, including one or more processors, configured to transmit an optical signal to a plurality of optical network units or receive multiple optical signals from the plurality of optical network units via optical transfer paths, and
a control unit, including one or more processors, configured to:
receive a monitoring value of the optical signal at a first optical network unit included in the plurality of optical network units, wherein the monitoring value changes according to a receive signal quality of the optical signal,
determine that the monitoring value has changed to a value indicating deterioration of the receive signal quality,
determine an adjust power value based on an upper limit value and a lower limit value for each of the plurality of optical network units, and
change a launch power of the optical signal based on the adjust power value to obtain a changed optical signal, such that, a receive power of the changed optical signal in each of the plurality of optical network units is lower than or equal to an upper limit value of the corresponding optical network unit and a receive power of the changed optical signal in the first optical network unit is higher than or equal to a lower limit value of the first optical network unit.