The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services.
The present invention provides a method of a base station for supporting an inter-system handover from an evolved packet system (EPS) system to a 5th generation (5G) system. The method comprises receiving, from an access and mobility management function (AMF), a handover request message including E-UTRAN radio access bearer (E-RAB) information and quality of service (Qos) flow information, identifying whether a protocol data unit (PDU) session is accepted or not, determining whether a data forwarding for at least one Qos flow associated with the PDU session is accepted or not based on the E-RAB information and the Qos flow information in case that the PDU session is accepted and transmitting, to the AMF, a handover request acknowledgement message including information on the at least one Qos flow based on the determination. The method solves the data forwarding problem during the movement of a UE between an LTE system and a 5G system, so that the loss of data is avoided and the continuity of services is ensured.