The present disclosure relates to a power saving in wireless communications. According to an embodiment of the present disclosure, a method performed by a central unit (CU) of a secondary node (SN) serving a wireless device with a master node (MN) in a dual connectivity (DC) in a wireless communication system comprises: transmitting, to a distributed unit (DU) of the SN, a first message comprising an instruction to deactivate one or more cells in a secondary cell group (SCG) related to the SN, wherein the one or more cells comprise a primary secondary cell (PSCell); receiving, from the DU, a second message comprising information informing a successful deactivation of the one or more cells; determining a list of cells to be activated in the SCG based on at least one of an amount of packets received by the CU or a measurement report received from the wireless device, wherein the list of cells comprises the PSCell; transmitting, to the DU, a third message comprising information informing the list of cells to be activated in the SCG; and receiving, from the DU, a fourth message comprising information informing a successful activation of the list of cells.