For example, an Access Point (AP) may be configured to set an Association Identifier (AID) field to a predefined AID value. For example, the predefined AID value may be configured to indicate that a non-AP station (STA) having latency-sensitive traffic is to be allowed to transmit a non-Trigger-Based (non-TB) Physical layer (PHY) Protocol Data Unit (PPDU) including the latency-sensitive traffic according to a channel contention mechanism during a contention-based time period. For example, the AP may be configured to transmit a trigger frame to allocate the contention-based time period. For example, the trigger frame may include the AID field.