| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a PON system capable of achieving time correction with high accuracy by a simple structure. <P>SOLUTION: In a PON system, an OLT1 performs time synchronization processing between the OLT 1 and a time synchronization client 3 connecting to an ONU 2. The ONU 2 comprises an upstream frame identification unit 22 for giving PON clock time at which the frame is received as a receiving PON clock to store it in a buffer unit 23 when an upstream frame is a time synchronization frame, and an uplink transmission control unit 24 for reading the time synchronization frame from the buffer unit 23, giving PON clock time at which the frame is transmitted as a transmission PON clock to transmit it to the OLT 1. The OLT 1 comprises a reference time correction unit for storing time information in which delay amount in the ONU 2 is corrected in accordance with the transmission PON clock and the receiving PON clock of the time synchronization frame to transmit it to the time synchronization client 3. <P>COPYRIGHT: (C)2012,JPO&INPIT |
