Abstract: In a wireless communication system, a first wireless communication unit receives a first data including identification information associated with the first data transmitted from a third wireless communication unit; generates, when needed to share a specific time with a second wireless communication unit, a second data associated with a first reception time of the received first data; and transmits the second data and the identification information of the received first data. The second wireless communication unit calculates, upon reception of the identification information and the second data, if it is judged that the first data has previously been received based on the identification information, a time value needed to synchronize with the first wireless communication unit, based on a second reception time of the first data previously received and the first reception time of the first data associated with the second data transmitted from the first wireless communication unit.