The application provides a method, including: generating a Physical Layer (PHY) Protocol Data Unit (PPDU) comprising both information for one or more first-generation stations (R1 STAs) and information for one or more second-generation stations (R2 STAs); and transmitting the PPDU to the one or more R1 STAs and the one or more R2 STAs, wherein a preamble portion of the PPDU comprises Resource Unit (RU) allocation entries corresponding to the one or more R1 STAs and RU allocation entries corresponding to the one or more R2 STAs.