A method of a terminal may comprise: receiving, from a CU of a base station, configuration information of one or more candidate cells and configuration information for measurement; performing L1 measurement on the candidate cells based on the configuration information for measurement; acquiring uplink synchronization for the candidate cells by performing an uplink synchronization management procedure for the candidate cells based on the configuration information of the candidate cells; reporting a result of the L1 measurement to a DU of the base station; receiving, from the DU of the base station, information on a target cell, being the target cell to switch among the candidate cells, based on the result of the L1 measurement; and applying the uplink synchronization acquired through the uplink synchronization management procedure to the target cell.