Patent ID: 8620581

Claim:
A method of performing time synchronization using a navigation device, comprising: (a) performing time synchronization between a GPS satellite and the navigation device by receiving GPS signals at the navigation device from at least one GPS satellite; (b) establishing an interface between the navigation device and a time-using device, the time-using device being a clock device installed in a transporter or a black box installed in a transporter; (c) setting a time period for transmitting time information to the navigation device; (d) performing time synchronization between the navigation device and the time-using device by transmission of current time information from the navigation device to the time-using device periodically according to the set time period, and (e) changing from the time-using device to an internal clock generation mode to generate a clock according to its internal clock, when time synchronization between the time-using device and the navigation device is cut off because the GPS satellite is not communicating with the navigation device.