Embodiments of a user equipment (UE) configurable for unlicensed band operation in a 5G NR system (5GS), when operating in semi-static channel access mode, for a UE-initiated channel-occupancy time (COT), is configured to transmit an uplink (UL) transmission burst, as an initiating device, starting at a beginning of fixed frame period (FFP) and ending at a symbol before an idle period of the FFP after a successful clear-channel assessment (CCA).