Embodiments of an access point (AP), station (STA) and methods of communication are generally described herein. The AP may transmit a trigger frame (TF) that indicates resource units (RUs) that are available for contention based access by STAs for a fine timing measurement (FTM) protocol. The AP may attempt to decode one or more initial fine timing measurement request (iFTMR) frames received in the indicated RUs. The AP may transmit a broadcast acknowledgement (ACK) frame that indicates whether at least one iFTMR frame was decoded. The AP may, for a decoded iFTMR frame: allocate the RU corresponding to the decoded iFTMR frame to a corresponding STA for the FTM protocol; and transmit, in the corresponding RU, an initial fine timing measurement (iFTM) frame that includes an identifier of the corresponding STA.