A communication scheme and a system thereof are provided for converging IoT technology and a 5G communication system for supporting a high data transmission rate beyond that of a 4G system. The disclosure can be applied to intelligent services based on the 5G communication technology and the IoT-related technology. The disclosure provides a method of minimizing a handover delay and a handover failure possibility of the terminal in a mobile communication system, which includes receiving a handover command from a first BS; performing DL synchronization with a second BS; determining whether a first UL signal to be transmitted to the first BS and a second UL signal to be transmitted to the second BS overlap; and in response to determining that the first UL signal and the second UL signal overlap, transmitting the second UL signal to the second BS, wihtout transmitting the first UL signal to the first BS.