US 12,457,090 B2
Vehicle-mounted device, vehicle-mounted communication system, and time synchronization method
Tadashi Matsumoto, Yokkaichi (JP); Kazuki Kitagawa, Yokkaichi (JP); Kazuyuki Inoue, Yokkaichi (JP); Yojiro Suyama, Osaka (JP); Tatsuya Izumi, Osaka (JP); and Hideyuki Tanaka, Osaka (JP)
Assigned to AutoNetworks Technologies, Ltd., Yokkaichi (JP); Sumitomo Wiring Systems, Ltd., Yokkaichi (JP); and Sumitomo Electric Industries, Ltd., Osaka (JP)
Appl. No. 18/574,013
Filed by AutoNetworks Technologies, Ltd., Yokkaichi (JP); Sumitomo Wiring Systems, Ltd., Yokkaichi (JP); and Sumitomo Electric Industries, Ltd., Osaka (JP)
PCT Filed Jun. 27, 2022, PCT No. PCT/JP2022/025516
§ 371(c)(1), (2) Date Dec. 23, 2023,
PCT Pub. No. WO2023/282107, PCT Pub. Date Jan. 12, 2023.
Claims priority of application No. 2021-112535 (JP), filed on Jul. 7, 2021.
Prior Publication US 2024/0372694 A1, Nov. 7, 2024
Int. Cl. H04L 7/00 (2006.01); H04L 7/033 (2006.01)
CPC H04L 7/0033 (2013.01) [H04L 7/0335 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A vehicle-mounted device comprising:
a storage unit configured to store delay time information including at least one of
a first set including a first transmission delay time from an external portion to a measurement reference position at a data reception time in an own device that is the vehicle-mounted device, and a second transmission delay time from an external portion to a measurement reference position at a data reception time in another device that is a different vehicle-mounted device, and
a second set including a third transmission delay time from a measurement reference position to an external portion at a data transmission time in the own device, and a fourth transmission delay time from a measurement reference position to an external portion at a data transmission time in the other device;
a processing unit configured to measure a propagation delay time between the own device and the other device by transmitting and receiving time synchronization information to and from the other device;
a correction unit configured to correct the propagation delay time measured by the processing unit, based on the delay time information stored in the storage unit; and
a time synchronization unit configured to perform time synchronization between the own device and the other device based on the corrected propagation delay time obtained by the correction unit,
the vehicle-mounted device further comprising
a relay unit configured to relay data at three or more communication ports,
wherein pieces of the delay time information are in one-to-one correspondence with the communication ports, and the storage unit stores a piece of the delay time information corresponding to a portion of the communication ports among the three or more communication ports, and
the correction unit corrects the propagation delay time measured by the processing unit, based on the delay time information corresponding to the portion of the communication ports stored in the storage unit.