The disclosure relates to an access point device (AP) for communicating with a client device (STA). The AP may include a transceiver configured to transmit a first data packet indicating a set of groups, wherein each group of the set of groups is associated with a specific set of transmission parameters. The transceiver of the AP may also be configured to transmit a second data packet indicating an allocation for at least part of the groups. Furthermore, the transceiver of the AP may also be configured to receive a response frame using at least part of random access (RA) resources selected by the STA for the at least part of the groups.