COMMUNICATION SYSTEM AND TIME SYNCHRONIZATION METHOD

• Main Authors: MITSUNAGA DAIJI, MIZUTANI MASAHIKO, NAKAZAWA HIROAKI, NAKANISHI AKIYUKI, ASHI MASAHIRO
• Format: Patent
• Language: English; Japanese
• Published: 09.04.2015
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; ELECTRONIC TIME-PIECES; HOROLOGY; PHYSICS; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

PROBLEM TO BE SOLVED: To avoid an influence of fluctuation in a communication delay time and perform highly accurate time synchronization in a wide area distribution system in which a network having no delay guarantee is used as a relay network.SOLUTION: First and second delay control devices 10 and 20, respectively installed at contact points between communication networks 210 and 220 and a relay network 100, respectively have functions of: retaining first and second time information and setting a first relay network passage time for a first communication signal from a time distribution device 30 to a time reception device 40 through the relay network 100; and setting a second relay network passage time for a second communication signal from the time reception device 40 to the time distribution device 30. At the measurement of a communication delay time between the first communication network 210 and the second communication network 220 preceding time synchronization, the uncertainty of a communication time in the delay measurement time in a relay network section is eliminated by the unification of the first and second relay network passage times in advance. 【課題】 遅延保証のないネットワークを中継網とする広域分散システムにおいて、通信遅延時間の揺らぎの影響を回避し、高精度の時刻同期を行う。【解決手段】 通信網２１０、２２０と中継網１００との接点にそれぞれ設置された第１及び第２の遅延制御装置１０、２０は、それぞれ第１及び第２の時刻情報を保持し、中継網１００を通過して時刻配信装置３０から時刻受信装置４０へ向かう第１の通信信号に対する第１の中継網通過時間と、時刻受信装置４０から時刻配信装置３０へ向かう第２の通信信号に対する第２の中継網通過時間を設定する機能を備える。時刻同期に先立つ第１の通信網２１０と第２の通信網２２０との通信遅延時間の測定に際し、第１及び第２の中継網通過時間を予め統一することによって、遅延測定時間のうち中継網区間における通信時間の不確定性を排除する。【選択図】 図１