A method performed by a session management function, SMF, entity in a wireless communication system, the method comprising: receiving, from an access and mobility management function, AMF, entity, a handover request message for a protocol data unit, PDU, session associated with a terminal; determining whether there is connectivity between a target radio access network, RAN, and an anchor user plane function, UPF, entity for the PDU session associated with the terminal; selecting an intermediate UPF entity for establishing the connectivity, in case that there is no connectivity between the target RAN and the anchor UPF entity; transmitting, to the intermediate UPF entity, an N4 session establishment request message for updating data path for the PDU session, the N4 session establishment request message including identification address of the target RAN, identification address of the anchor UPF entity, and tunnel identification information used to setup N9 tunnel; receiving, from the intermediate UPF entity, an N4 session establishment response message as a response to the N4 session establishment request message, the N4 session establishment response message including an identification address of the intermediate UPF entity, tunnel identification information for N9 tunnel set up between the anchor UPF entity and the intermediate UPF entity, and tunnel identification information for N3 tunnel set up between the target RAN and the intermediate UPF entity; transmitting, to the anchor UPF entity, a modification request message including the tunnel identification information for N9 tunnel set up between the anchor UPF entity and the intermediate UPF entity; receiving, from the anchor UPF entity, a modification response message as a response to the modification request message; and transmitting, to the AMF entity, a handover response message for the PDU session including identification information of the PDU session and the tunnel identification information for the N3 tunnel set up between the target RAN and the intermediate UPF entity. receiving, from an access and mobility management function, AMF, entity, a handover request message for a protocol data unit, PDU, session associated with a terminal; determining whether there is connectivity between a target radio access network, RAN, and an anchor user plane function, UPF, entity for the PDU session associated with the terminal; selecting an intermediate UPF entity for establishing the connectivity, in case that there is no connectivity between the target RAN and the anchor UPF entity; transmitting, to the intermediate UPF entity, an N4 session establishment request message for updating data path for the PDU session, the N4 session establishment request message including identification address of the target RAN, identification address of the anchor UPF entity, and tunnel identification information used to setup N9 tunnel; receiving, from the intermediate UPF entity, an N4 session establishment response message as a response to the N4 session establishment request message, the N4 session establishment response message including an identification address of the intermediate UPF entity, tunnel identification information for N9 tunnel set up between the anchor UPF entity and the intermediate UPF entity, and tunnel identification information for N3 tunnel set up between the target RAN and the intermediate UPF entity; transmitting, to the anchor UPF entity, a modification request message including the tunnel identification information for N9 tunnel set up between the anchor UPF entity and the intermediate UPF entity; receiving, from the anchor UPF entity, a modification response message as a response to the modification request message; and transmitting, to the AMF entity, a handover response message for the PDU session including identification information of the PDU session and the tunnel identification information for the N3 tunnel set up between the target RAN and the intermediate UPF entity.