A method for packet data convergence protocol, PDCP, protocol data unit, PDU, duplication for a user equipment, UE, the method comprising: receiving, from a base station, through radio resource control, RRC, signaling, a PDCP duplication configuration for a PDCP entity, the configuration indicating: i) an association between the PDCP entity and a plurality of radio link control, RLC, entities; ii) an RLC entity in the plurality of the RLC entities being a primary path; and iii) one or more of the RLC entities as active RLC entities for transmitting duplicated PDCP PDUs, the active RLC entities include RLC entities that are not indicated as the primary path; generating, by the PDCP entity, one or more duplicated PDCP PDUs when a PDCP duplication function activation indicator is received; transmitting, by the PDCP entity, the generated one or more duplicated PDCP PDUs to the one or more active RLC entities; and receiving a medium access control, MAC, control element, CE, comprising a plurality of fields for switching at least one of the one or more active RLC entities, excluding the RLC entity that is the primary path, to an inactive RLC entity; wherein: the UE is configured with a plurality of dedicated radio bearers, DRBs, and each of the plurality of DRBs is configured with a PDCP duplication function, the received MAC CE comprises a first field that has more than one bit and the value of the first field is associated with one of the plurality of DRBs, and the plurality of fields of the MAC CE comprises the first field for identifying the DRB associated with the MAC CE and at least a second field for indicating whether a corresponding RLC entity is active or inactive. receiving, from a base station, through radio resource control, RRC, signaling, a PDCP duplication configuration for a PDCP entity, the configuration indicating: i) an association between the PDCP entity and a plurality of radio link control, RLC, entities; ii) an RLC entity in the plurality of the RLC entities being a primary path; and iii) one or more of the RLC entities as active RLC entities for transmitting duplicated PDCP PDUs, the active RLC entities include RLC entities that are not indicated as the primary path; i) an association between the PDCP entity and a plurality of radio link control, RLC, entities; ii) an RLC entity in the plurality of the RLC entities being a primary path; and iii) one or more of the RLC entities as active RLC entities for transmitting duplicated PDCP PDUs, the active RLC entities include RLC entities that are not indicated as the primary path; generating, by the PDCP entity, one or more duplicated PDCP PDUs when a PDCP duplication function activation indicator is received; transmitting, by the PDCP entity, the generated one or more duplicated PDCP PDUs to the one or more active RLC entities; and receiving a medium access control, MAC, control element, CE, comprising a plurality of fields for switching at least one of the one or more active RLC entities, excluding the RLC entity that is the primary path, to an inactive RLC entity; the UE is configured with a plurality of dedicated radio bearers, DRBs, and each of the plurality of DRBs is configured with a PDCP duplication function, the received MAC CE comprises a first field that has more than one bit and the value of the first field is associated with one of the plurality of DRBs, and the plurality of fields of the MAC CE comprises the first field for identifying the DRB associated with the MAC CE and at least a second field for indicating whether a corresponding RLC entity is active or inactive.