A method, comprising: receiving, by a processor of an apparatus, first control information in a first transmission time interval, TTI,; wherein the first control information indicates whether downlink data or second control information for the apparatus is scheduled in a second TTI; and turning off a radio frequency, RF, transceiver of the apparatus in part of the second TTI when the first control information in the first radio carrier indicates that no downlink data or second control information is scheduled in the second radio carrier; wherein the downlink data or the second control information is not scheduled in the first TTI; wherein the apparatus is configured to establish a first radio carrier and a second radio carrier with a network apparatus; wherein the processor of the apparatus monitors the first control information in the first radio carrier in the first TTI; wherein the processor of the apparatus determines whether to receive the downlink data or the second control information in the second radio carrier in the second TTI according to the first control information; wherein the first control information indicates whether the downlink data or the second control information for the apparatus is scheduled in the second radio carrier in the second TTI; wherein the bandwidth of the second radio carrier is greater than that of the first radio carrier; wherein it is characterized in that there is a time gap between the first control information in the first radio carrier in the first TTI and the downlink data or the second control information in the second radio carrier in the second TTI. receiving, by a processor of an apparatus, first control information in a first transmission time interval, TTI,; wherein the first control information indicates whether downlink data or second control information for the apparatus is scheduled in a second TTI; and turning off a radio frequency, RF, transceiver of the apparatus in part of the second TTI when the first control information in the first radio carrier indicates that no downlink data or second control information is scheduled in the second radio carrier; wherein the downlink data or the second control information is not scheduled in the first TTI; wherein the apparatus is configured to establish a first radio carrier and a second radio carrier with a network apparatus; wherein the processor of the apparatus monitors the first control information in the first radio carrier in the first TTI; wherein the processor of the apparatus determines whether to receive the downlink data or the second control information in the second radio carrier in the second TTI according to the first control information; wherein the first control information indicates whether the downlink data or the second control information for the apparatus is scheduled in the second radio carrier in the second TTI; wherein the bandwidth of the second radio carrier is greater than that of the first radio carrier; wherein it is characterized in that there is a time gap between the first control information in the first radio carrier in the first TTI and the downlink data or the second control information in the second radio carrier in the second TTI.