| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem that in case of configuring a PON in which a communication distance between an OLT and an ONU is dispersed in a range equal to or more than a predetermined range by a conventional optical receiver, when the neighborhood ONU receives a signal which has an optical intensity necessary for communication between the OLT and the remote ONU, the optical intensity is too high and causes failure in an ONU receiver. <P>SOLUTION: In the ONU, the optical intensity of a downstream signal is measured, and the optical intensity is attenuated by a variable ATT comprised before that an optical signal is input to an optical receiver. Thereby, the optical intensity of the downstream signal which changes according to a path distance from the OLT to each ONU can be adjusted to the appropriate optical intensity before being input into the optical receiver. When emitting light of an upstream signal from the ONU, in the ONU, the optical signal which is to be emitted from an optical transmitter is attenuated at the variable ATT by referring to an attenuation setting in case of receiving a downstream optical signal, and the optical signal is adjusted to the appropriate optical intensity according to the path distance which can reach the OLT. <P>COPYRIGHT: (C)2012,JPO&INPIT |
