US 12,224,851 B2
Time synchronization device, time synchronization system, and recording medium
Lei Li, Tokyo (JP); and Takashi Ichimura, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Appl. No. 17/924,116
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Jul. 1, 2020, PCT No. PCT/JP2020/025827
§ 371(c)(1), (2) Date Nov. 9, 2022,
PCT Pub. No. WO2022/003865, PCT Pub. Date Jan. 6, 2022.
Prior Publication US 2023/0179312 A1, Jun. 8, 2023
Int. Cl. H04J 3/06 (2006.01)
CPC H04J 3/0638 (2013.01) 16 Claims
OG exemplary drawing
 
1. A time synchronization device connectable to a time retaining device retaining a time to execute time synchronization with the time retaining device, together with another time synchronization device not connected to the time retaining device, the time synchronization device comprising:
a synchronization information transmitter to transmit synchronization information on time synchronization to the another time synchronization device;
a request information receiver to receive request information that is based on the synchronization information, the request information being transmitted from the another time synchronization device after transmission of the synchronization information from the synchronization information transmitter;
a response information transmitter to transmit, to the another time synchronization device, response information responding to the request information received by the request information receiver; and
a time corrector (i) to execute time correction based on a propagation delay time between the time retaining device and the time synchronization device during a period different from a predetermined period from transmission of the synchronization information from the synchronization information transmitter until reception of the request information by the request information receiver, the propagation delay time being calculated from times identified through transmission and reception of information to and from the time retaining device, and (ii) not to execute time correction during the predetermined period even when information is received from or transmitted to the time retaining device.