Preempting a slot with a mini-slot for use in a wireless transmitter of a wireless communication network is presented. The method includes preempting a slot transmission to a wireless receiver with a mini-slot transmission to the wireless receiver, wherein the slot transmission comprises a plurality of time-frequency regions (TFRs), each TFR comprising a plurality of sub-regions. The method further includes transmitting a preemption indication to the wireless receiver, where the preemption indication includes a TFR position in time of one or more preempted TFRs in the slot transmission, a TFR position in frequency of the one or more preempted TFRs in the slot transmission and an identifier of one or more of the plurality a sub-regions of the one more preempted TFRs.