TIME SYNCHRONIZATION DEVICE AND METHOD

• Main Authors: HONDA YASUMASA, TOMINAGA SATOKO, HAYASHI TAKANORI, KOBAYASHI FUMIYA, MASUDA YUKITAKA, YOSHIMURA NORIKO
• Format: Patent
• Language: English
• Published: 17.06.2013
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

PROBLEM TO BE SOLVED: To estimate a clock skew among plural NW apparatuses in a case where a round-trip delay can be determined to be according to a stochastic process satisfying a predetermined condition when synchronizing time for the apparatuses.SOLUTION: In a NW apparatus, an SR packet being a time information request is sent out to an opposite apparatus; a corresponding RR packet is sent out to the opposite apparatus upon receiving an SR packet therefrom; and elapse time information is recorded to the RR packet. At reception of the RR packet, a round-trip delay is estimated based on time-stamp information contained in the RR packet; time-series of round-trip delay time estimation values is stored as a log in storage means; and a clock skew between the apparatuses is estimated by means of linear regression on the basis of: the time series of round-trip delay time estimation values stored in the storage means; and the round-trip delay time measurement log of the opposite apparatus.