A user device for a wireless communication system comprises a processor, configured to determine an on-duration period of an activity cycle, check that a channel state information (CSI) is valid, and monitor a down link control channel only while the CSI is valid and the user device is in the on-duration period of the activity cycle. A network node comprises a processor; and a transceiver; wherein the processor is configured to determine an on-duration period of an activity cycle, wherein the transceiver is configured to receive CSI updates, and wherein the processor further is configured to check that the CSI is valid, and to transmit data on a down link control channel only while the CSI is valid and the processor is in the on-duration period of the activity cycle.