Patent ID: 11855760

Abstract:
The accuracy of an offset value is improved by correcting an error in time synchronization caused by link asymmetry. PTP packets are exchanged between a master node 3 and a slave node 4 vis a first transmission device 1 connected to the master node 3 and a second transmission device 2 corresponding to the first transmission device 1 and connected to the slave node 4. The second transmission device 2 includes: a transmission section 16 configured to transmit PTP packets for a plurality of wavelengths to the corresponding transmission device simultaneously; and a reception section 17 configured to calculate a propagation delay Dms on a path from the corresponding transmission device to the second transmission device 2 based on a difference between the arrival times of the PTP packets for the plurality of wavelengths received from the corresponding transmission device, and provide the propagation delay Dms to the slave node 4 as a correction parameter used in a process of synchronizing the time of the slave node 4.