A method performed by a User Equipment, UE, configured with a plurality of serving cells, the method comprising: receiving, through Radio Resource Control, RRC, signaling from a Base Station, BS, an indication indicating a dormancy cell group having at least a first serving cell and a second serving cell of the plurality of serving cells; receiving, from the BS, a first indicator indicating to the UE that a dormant behavior applicable to the first serving cell of the dormancy cell group is to be activated when the first serving cell is activated, the dormant behavior including stopping monitoring a Physical Downlink Control Channel, PDCCH, of the first serving cell; receiving, from the BS, a second indicator indicating to the UE that a dormant behavior applicable to the second serving cell of the dormancy cell group is to be deactivated when the second serving cell is activated, the dormant behavior including stopping monitoring a PDCCH of the second serving cell; receiving, through Media Access Control, MAC, signaling from the BS, a cell activation indication to activate the first serving cell and the second serving cell; activating the first serving cell and the second serving cell based on the cell activation indication; applying the dormant behavior to the first serving cell based on the first indicator when the first serving cell is activated; not applying the dormant behavior to the second serving cell based on the second indicator when the second serving cell is activated; receiving, through Physical Layer, PHY, signaling from the BS, a signal associated with a specific Downlink Control Information, DCI, format indicating a group dormant behavior applicable to all serving cells in the dormancy cell group, wherein the signal indicates the group dormant behavior via a single bit; applying the dormant behavior to the first serving cell and the second serving cell when the signal indicates that the group dormant behavior is to be activated; and not applying the dormant behavior to the first serving cell and the second serving cell when the signal indicates that the group dormant behavior is to be deactivated. receiving, through Radio Resource Control, RRC, signaling from a Base Station, BS, an indication indicating a dormancy cell group having at least a first serving cell and a second serving cell of the plurality of serving cells; receiving, from the BS, a first indicator indicating to the UE that a dormant behavior applicable to the first serving cell of the dormancy cell group is to be activated when the first serving cell is activated, the dormant behavior including stopping monitoring a Physical Downlink Control Channel, PDCCH, of the first serving cell; receiving, from the BS, a second indicator indicating to the UE that a dormant behavior applicable to the second serving cell of the dormancy cell group is to be deactivated when the second serving cell is activated, the dormant behavior including stopping monitoring a PDCCH of the second serving cell; receiving, through Media Access Control, MAC, signaling from the BS, a cell activation indication to activate the first serving cell and the second serving cell; activating the first serving cell and the second serving cell based on the cell activation indication; applying the dormant behavior to the first serving cell based on the first indicator when the first serving cell is activated; not applying the dormant behavior to the second serving cell based on the second indicator when the second serving cell is activated; receiving, through Physical Layer, PHY, signaling from the BS, a signal associated with a specific Downlink Control Information, DCI, format indicating a group dormant behavior applicable to all serving cells in the dormancy cell group, wherein the signal indicates the group dormant behavior via a single bit; applying the dormant behavior to the first serving cell and the second serving cell when the signal indicates that the group dormant behavior is to be activated; and not applying the dormant behavior to the first serving cell and the second serving cell when the signal indicates that the group dormant behavior is to be deactivated.