FIG. 9 shows examples of slots 1183 and sub-slots 1107. If a sub-slot 1107 is not configured by higher layer, the UE 102 and the eNB/gNB 160 may only use a slot 1183 as a scheduling unit. More specifically, a given transport block may be allocated to a slot 1183. If the sub-slot 1107 is configured by higher layer, the UE 102 and the eNB/gNB 160 may use the sub-slot 1107 as well as the slot 1183. The sub-slot 1107 may include one or more OFDM symbols. The maximum number of OFDM symbols that constitute the sub-slot 1107 may be NDLsymb-1 (or NULsymb-1).
The sub-slot length may be configured by higher layer signaling. Alternatively, the sub-slot length may be indicated by a physical layer control channel (e.g., by DCI format).