Patent ID: 8626869

Claim:
A communication apparatus having a clock unit, and a communication unit for sending and receiving data, comprising: a data generating unit that generates a first data; a generation obtaining unit that obtains a generating time point based on the clock unit and corresponding to the time that the first data is generated; a sending obtaining unit that obtains a sending start time point based on the clock unit and corresponding to the time that the communication unit starts to externally send the first data; a calculation unit that calculates a time lag between the generating time point and the sending start time point; an addition unit that adds time lag information onto the first data, the time lag information indicating the time lag calculated by the calculation unit; a reception determination unit that determines a receiving start time point based on the clock unit and corresponding to the time that the communication unit externally receives a second data; an extraction unit that extracts added time lag information from the second data; and a generation determination unit that determines a data generating time point of the second data based on the added time lag information and the receiving start time point, wherein the communication unit externally sends the first data onto which the time lag information has been added by the addition unit.