COMMUNICATION SYSTEM, AND DEVICE THEREOF

• Main Authors: MIZUTANI MASAHIKO, ASHI MASAHIRO
• Format: Patent
• Language: English
• Published: 26.03.2009
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; ELECTROMECHANICAL CLOCKS OR WATCHES; ELECTRONIC TIME-PIECES; HOROLOGY; PHYSICS; TRANSMISSION; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION; WIRELESS COMMUNICATIONS NETWORKS

PROBLEM TO BE SOLVED: To solve a problem that highly-accurate time synchronization of a terminal device is required. SOLUTION: A transmission device creates a correction value for time information of the terminal device using reciprocating transmission delay time between the terminal device and the time information of the transmission device, and transmits the value to the terminal device. The terminal device includes arrival expected time information based on the time information of the terminal device and the correction value received from the transmission device in a frame for transmitting to the transmission device. The transmission device compares the reception time of the frame and the arrival expected time information in the frame. When they coincide, the time information of the terminal device is synchronized with the time information of the transmission device. When they do not coincide, a new correction value is transmitted to the terminal device. The terminal device transmits the frame including the arrival expected time information using the new correction value to the transmission device. By repeating these processes, the time of the terminal device is synchronized with the time of the transmission device. COPYRIGHT: (C)2009,JPO&INPIT