Patent ID: 7876790

Claim:
An apparatus for performing time synchronization by using Global Positioning System (GPS) information in a communication system, the apparatus comprising: a grand-master node having a GPS receiver, and for generating a synchronizing message including Time Of Day (TOD) information received from the GPS receiver; and at least one slave node for receiving the synchronizing message from the grand-master node for carrying out time synchronization operation by using an Offset and Frequency Compensation Clock (OFCC) synchronization process supporting time offset and frequency separation compensation said OFCC comprising: checking a point in time when a relevant synchronizing message is received in relation to a point in time of previous frequency compensation when the synchronizing message is received from the master node, and confirming whether an interval between the point in time of the reception of the relevant synchronizing message and the point in time of the previous frequency compensation reaches a preset frequency compensation interval; wherein only a time offset compensation operation is performed if it is confirmed that the interval does not reach the preset frequency compensation interval; and both the time offset compensation operation and a frequency compensation operation are performed if it is confirmed that the interval reaches the preset frequency compensation interval.