| 摘要 |
PROBLEM TO BE SOLVED: To provide a discovery method capable of preventing the reduction of band use efficiency, even if an ONU having a long transmission wavelength switchover time exists at the registration of the ONU.SOLUTION: In the discovery method, a time (transmission permission period) from the time of receiving a search signal to the time transmittable of a response signal is set to be constant, irrespective of a time required for wavelength switchover at the ONU. In regard to an ONU having a set wavelength of an optical transmitter in the ONU, different from a wavelength (output light wavelength) required for the response signal, the response signal is not transmitted but awaited. Accordingly, the extension of a discovery time is not necessary even if an ONU having a long wavelength switchover time exists, and the reduction of the band use efficiency can be prevented. |
