Time synchronization system and time synchronization method
US11196533B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 2019 |
| Grant date | Dec 7, 2021 |
| Priority date | — |
| Expiry date | Feb 15, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J3/0682
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
[Problem] To synchronize timings of transmitting and receiving a pulse signal (1 PPS signal) at a constant interval between communication apparatuses even in a case where an optical fiber connecting the communication apparatuses fluctuates in an optical characteristic and an optical fiber length.[Solution] The time synchronization system 20 transmits and receives a pulse signal at a constant interval between a local apparatus L (apparatus L) and a remote apparatus R (apparatus R) connected through the two-core bidirectional optical fibers F1 and F2 to synchronize time. A propagation delay amount τ1 in the fiber F1 is calculated, from a proportional relationship between T1 and T2 and a proportional relationship of τud and τ1, where T1 represents a propagation delay time difference between a pulse signals P1 and P4 of an identical wavelength λ1 returned after transmitting a pulse signal P1 of wavelength λ1 and a pulse signal P2 of wavelength λ2 different from λ1 to the remote apparatus R, T2 represents a propagation delay time difference between the pulse signal P1 of wavelength λ1 and a pulse signal P3 of wavelength λ2, and τud represents the round-trip delay time between the appara…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.