ivity timer: The time interval during which the UE waits for successful decoding of the PDCCH, starting from the last successful decoding of a PDCCH. If the decoding fails, the UE can go back to sleep. The UE restarts the inactivity timer following a sin- gle successful decoding of a PDCCH for the first transmission only (i.e., not for retransmissions). Retransmission-timer: The time interval until a retransmission can be expected. Cycle: It specifies the periodic repetition of the on-duration followed by a possible period of inactivity. Active-time: The total time duration that the UE monitors PDCCH. This includes the on-duration of the DRX cycle, the time that the UE is performing continuous reception while the inactivity timer is running, and the time when the UE is performing continu- ous reception while awaiting a retransmission opportunity. 256 Chapter 2 Due to bursty nature of the packet data traffic, which is characterized by intermittent periods of transmission activity followed by longer periods of inactivity, and to reduce the UE power consumption, NR supports a DRX scheme similar to that of LTE. Bandwidth adaptation and dynamic carrier activation/deactivation are two other power- saving mechanisms supported in NR. The underlying mechanism for DRX is a configur- able DRX cycle in the device. When a DRX cycle is configured, the device monitors the downlink control channel only during the active-time and sleeps, with its receiver circuitry switched off, during the inactivity time, leading to a significant reduction in UE power consumption. The longer the DRX inactive time, the lower the power con- sumption. However, this would have certain implications for the scheduler, since the device is only reachable when it is active according to the DRX cycle configured for it. In many cases, if the device has been scheduled and is engaged in receiving or transmit- ting data, it is likely that it will be scheduled again soon; thus waiting until the next activity period according to the DRX cycle would result in ad