Embodiments of a User Equipment (UE), generation Node-B (gNB) and methods of communication are generally described herein. The UE may receive a narrowband physical downlink control channel (NPDCCH) that includes an uplink scheduling parameter. The UE may determine an uplink scheduling delay for transmission of a narrowband physical uplink shared channel (NPUSCH) in accordance with time-division duplexing (TDD). The uplink scheduling delay may be based on a sum of a predetermined first number of subframes and a variable second number of subframes. The second number of subframes may be based on a window of variable size that starts when the first number of subframes has elapsed since reception of the NPDCCH, and ends when a number of uplink subframes has elapsed since the start of the window. The number of uplink subframes may be indicated by the uplink scheduling parameter.