ffic as well as the channel quality, thus effi- ciently utilizing the available resources in order to maximize the network capacity. Semi- static scheduling implies that the transmission parameters are provided to the devices in advance and are not changed on a dynamic basis. The scheduler operation takes into account the UE buffer status and the QoS requirements of each UE as well as the associated radio bearers when assigning radio resources among active UEs (see Fig. 4.26). The schedulers assign network resources to the UEs by consider- ing the radio conditions as seen by the UEs, identified through measurements made at the gNB and/or reported by the UE. The schedulers assign radio resources in a unit of slot, for example, one mini-slot, one slot, or multiple slots and resource assignments consist of radio resources (time, frequency, code, space, power). The UEs identify the allocated resources by receiving a scheduling decision (resource assignment) through PDCCH. The UE periodi- cally or on-demand basis conducts measurements to support scheduler operation. The uplink buffer status reports (measuring the data that is buffered in the logical channel queues in the UE) are used to provide support for QoS-aware packet scheduling. Power headroom reports Chapter 4 Measurements Buffer status Associated radio Scheduling (UE/Network) reports requirements bearer request Scheduler Resource allocation/ Monitor PDCCH DCI (PDCCH)/C-RNTI CS (RRC signaling) CS (RRC signaling) CS (RRC signaling) PDSCH [periodicity] [periodicity] [periodicity] Monitor PDCCH Monitor PDCCH Monitor PDCCH Activating CS DCI (PDCCH)/CS-RNTI PUSCH DCI (PDCCH)/CS-RNTI PDSCH Activating CS No PDCCH PUSCH PUSCH DCI (PDCCH)/C-RNTI PDSCH PDSCH No PDCCH PUSCH PUSCH PDSCH PUSCH DCI (PDCCH)/C-RNTI DCI (PDCCH)/C-RNTI DCI (PDCCH)/C-RNTI DCI (PDCCH)/C-RNTI PDSCH If received overwrites CS If received overwrites CS If received overwrites CS PDSCH Without configured scheduling With configured scheduling (CS) With type 1 configured With type 2 configured scheduling 