A method for handing over a network in a source network slice to a target network slice, wherein the network comprises a control plane, CP, and a user plane, UP, which are separated from each other and a mobility management, MM, network element, and a session management, SM, network element, in the CP are separated from each other and wherein the source and the target network slice comprise a plurality of SM network elements and UP function entities and share the MM network element, comprising: determining, by the MM network element, to hand over an SM for user equipment, UE; selecting, by the MM network element, a target SM network element; and triggering, by the MM network element, a process of setting up a channel by the target SM network element, wherein the channel comprises a UP data channel between a target UP function entity and a target base station, wherein the triggering, by the MM network element, a process of setting up a channel by the target SM network element comprises: sending, by the MM network element to the target SM network element, a user equipment identifier, UE ID, an address of a source SM network element, and information indicating an address of the target base station, wherein the information indicating the address of the target base station comprises the address of the target base station or information to be mapped to the address of the target base station, characterized in that the process of setting up the channel by the target SM network element comprises: exchanging, by the target SM network element, a parameter used to set up the UP data channel between the target UP function entity and the target base station, with the target base station based on the address of the target base station or the information to be mapped to the address of the target base station. determining, by the MM network element, to hand over an SM for user equipment, UE; selecting, by the MM network element, a target SM network element; and triggering, by the MM network element, a process of setting up a channel by the target SM network element, wherein the channel comprises a UP data channel between a target UP function entity and a target base station, wherein the triggering, by the MM network element, a process of setting up a channel by the target SM network element comprises: sending, by the MM network element to the target SM network element, a user equipment identifier, UE ID, an address of a source SM network element, and information indicating an address of the target base station, wherein the information indicating the address of the target base station comprises the address of the target base station or information to be mapped to the address of the target base station, characterized in that the process of setting up the channel by the target SM network element comprises: exchanging, by the target SM network element, a parameter used to set up the UP data channel between the target UP function entity and the target base station, with the target base station based on the address of the target base station or the information to be mapped to the address of the target base station. sending, by the MM network element to the target SM network element, a user equipment identifier, UE ID, an address of a source SM network element, and information indicating an address of the target base station, wherein the information indicating the address of the target base station comprises the address of the target base station or information to be mapped to the address of the target base station, characterized in that the process of setting up the channel by the target SM network element comprises: exchanging, by the target SM network element, a parameter used to set up the UP data channel between the target UP function entity and the target base station, with the target base station based on the address of the target base station or the information to be mapped to the address of the target base station.