User equipment, UE (102, 200), comprising: a transceiver configured to transmit/receive signals to/from a plurality of serving cells (512, 600); and processing circuitry configured to: determine at least one subframe to monitor for a physical downlink control channel, PDCCH, formed in accordance with a first Downlink Control Information, DCI, format, the first DCI format indicating a transmission state of the serving cells (512, 600); configure the transceiver to receive the at least one subframe containing the first DCI format; determine the transmission state of the serving cells (512, 600) based on the received first DCI format; and configure the transceiver to monitor at least one of the PDCCH and an enhanced PDCCH, EPDCCH, of serving cells (512, 600) determined to be in a first transmission state and to refrain from monitoring the at least one of the PDCCH and EPDCCH of serving cells (512, 600) determined to be in a second transmission state, wherein the at least one of the PDCCH and EPDCCH of serving cells (512, 600) determined to be in the first transmission state is configured to provide a scheduling assignment for the UE (102, 200), wherein the first DCI format is periodically transmitted in at least one subframe of each modification period of a plurality of modification periods, wherein the transmission state of the serving cells (512, 600) indicated by the first DCI format transmitted in the at least one subframe of each modification period of the plurality of modification periods is independent of that of the serving cells (512, 600) indicated by the first DCI format transmitted in the at least one subframe of other modification periods of the plurality of modification periods, and wherein the processing circuitry is further configured to configure the transceiver to receive higher layer signaling specifying the at least one subframe in which the UE (102, 200) monitors the first DCI format. a transceiver configured to transmit/receive signals to/from a plurality of serving cells (512, 600); and processing circuitry configured to: determine at least one subframe to monitor for a physical downlink control channel, PDCCH, formed in accordance with a first Downlink Control Information, DCI, format, the first DCI format indicating a transmission state of the serving cells (512, 600); configure the transceiver to receive the at least one subframe containing the first DCI format; determine the transmission state of the serving cells (512, 600) based on the received first DCI format; and configure the transceiver to monitor at least one of the PDCCH and an enhanced PDCCH, EPDCCH, of serving cells (512, 600) determined to be in a first transmission state and to refrain from monitoring the at least one of the PDCCH and EPDCCH of serving cells (512, 600) determined to be in a second transmission state, wherein the at least one of the PDCCH and EPDCCH of serving cells (512, 600) determined to be in the first transmission state is configured to provide a scheduling assignment for the UE (102, 200), wherein the first DCI format is periodically transmitted in at least one subframe of each modification period of a plurality of modification periods, wherein the transmission state of the serving cells (512, 600) indicated by the first DCI format transmitted in the at least one subframe of each modification period of the plurality of modification periods is independent of that of the serving cells (512, 600) indicated by the first DCI format transmitted in the at least one subframe of other modification periods of the plurality of modification periods, and wherein the processing circuitry is further configured to configure the transceiver to receive higher layer signaling specifying the at least one subframe in which the UE (102, 200) monitors the first DCI format. determine at least one subframe to monitor for a physical downlink control channel, PDCCH, formed in accordance with a first Downlink Control Information, DCI, format, the first DCI format indicating a transmission state of the serving cells (512, 600); configure the transceiver to receive the at least one subframe containing the first DCI format; determine the transmission state of the serving cells (512, 600) based on the received first DCI format; and configure the transceiver to monitor at least one of the PDCCH and an enhanced PDCCH, EPDCCH, of serving cells (512, 600) determined to be in a first transmission state and to refrain from monitoring the at least one of the PDCCH and EPDCCH of serving cells (512, 600) determined to be in a second transmission state, wherein the at least one of the PDCCH and EPDCCH of serving cells (512, 600) determined to be in the first transmission state is configured to provide a scheduling assignment for the UE (102, 200), wherein the first DCI format is periodically transmitted in at least one subframe of each modification period of a plurality of modification periods, wherein the transmission state of the serving cells (512, 600) indicated by the first DCI format transmitted in the at least one subframe of each modification period of the plurality of modification periods is independent of that of the serving cells (512, 600) indicated by the first DCI format transmitted in the at least one subframe of other modification periods of the plurality of modification periods, and wherein the processing circuitry is further configured to configure the transceiver to receive higher layer signaling specifying the at least one subframe in which the UE (102, 200) monitors the first DCI format.