Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
TIME SYNCHRONIZATION SYSTEM AND TIME SYNCHRONIZATION METHOD
Document Type and Number:
WIPO Patent Application WO/2020/026817
Kind Code:
A1
Abstract:
[Problem] To reduce overall equipment costs. [Solution] A local device 20A of a time synchronization system 10A is provided with: a route switching unit 33 which connects remote devices 40A1 to 40An using individual optical fibers 60a to 60n, and successively switches between the optical fibers 60a to 60n in a cyclic order; a counter unit 31; a phase difference memory unit 30; and a table unit 32. The counter unit 31 obtains a count value T1 by counting a pulse signal P1d demodulated by a pulse per second (PPS) demodulating unit 23. The phase difference memory unit 30 stores the count value T1, as route information, in association with a phase difference φ1 detected by a phase detecting unit 22, and outputs the phase difference φ1 associated with the route information to a variable delay unit 24 when the count value T1 representing the same route information is input. When the count value T1 is input, the table unit 32 outputs to the route switching unit 33 a route switching signal K for switching to the next optical fiber 60n in the cyclic order, and the route switching unit 33 switches to the next optical fiber 60n.

Inventors:
SAKUMA HIROKI (JP)
ARAI KAORU (JP)
HISASHIMA TAKAAKI (JP)
SUGIYAMA RYUTA (JP)
TSUBOI SHUNICHI (JP)
KUROKAWA OSAMU (JP)
MATSUMURA KAZUYUKI (JP)
Application Number:
PCT/JP2019/028125
Publication Date:
February 06, 2020
Filing Date:
July 17, 2019
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
NIPPON TELEGRAPH & TELEPHONE (JP)
International Classes:
G04G5/00; G04G7/00; G06F1/14; H04B10/07; H04B10/272; H04L7/00
Foreign References:
JPH10142361A1998-05-29
JP2016527748A2016-09-08
JP2006319899A2006-11-24
US20180062825A12018-03-01
Attorney, Agent or Firm:
ISONO INTERNATIONAL PATENT OFFICE, P.C. (JP)
Download PDF: