The application relates to ultra-low latency data transmission in Wireless Local Area Networks (WLANs). An apparatus used in an Access Point Station (AP STA), including processor circuitry configured to cause the AP STA to, when there is downlink urgent data that must be transmitted without waiting for a scheduled downlink slot: generate a downlink urgent packet from the downlink urgent data; and in a blank symbol of ongoing Orthogonal Frequency Division Multiplexing (OFDM) uplink transmission to the AP STA, transmit the downlink urgent packet on frequency domain resources for the ongoing OFDM uplink transmission to the AP STA, or in a blank symbol of ongoing OFDM downlink transmission from the AP STA, transmit the downlink urgent packet on frequency domain resources for the ongoing OFDM downlink transmission from the AP STA.