The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A method for preventing a loss of data packets of a transmission end is provided. The method includes performing a path switching operation, receiving, from a reception end, a switching status report that includes information related to the data packets that were not received by the reception end, and retransmitting the data packets that were not received by the reception end, where the path switching operation is an operation of switching a data transmission path from a first communication system to a second communication system or from the second communication system to the first communication system, and where the first communication system is a fourth generation (4G) communication system, and the second communication system is a fifth generation (5G) communication system that uses a millimeter-wave (mm-wave) band.