| 摘要 |
An ONU 1 that receives a discovery gate transmitted by an OLT in a predetermined cycle, returns a response signal in response to the discovery gate, and receives a unicast frame transmitted to the ONU 1 by the OLT having received the response signal, comprising: a received frame detecting unit 4 that detects whether a signal received from the OLT is a discovery gate or a unicast frame; and an erroneous emission detecting unit 5 that detects an abnormal emission state, based on a result detected by the received frame detecting unit 4. |
