SYSTEM AND METHOD FOR WLAN OFDMA DESIGN OF SUBCARRIER GROUPS AND FRAME FORMAT

Embodiments are provided for WLAN OFDMA operations in uplink and downlink transmissions. For OFDMA downlink transmission, an access point (AP) sends a signaling requesting protection of a transmission channel from access by stations (STAs) associated with the AP. The AP then sends an OFDMA physical layer Protocol Data Unit (PPDU) and a Block Acknowledgement Request (BAR) to the STAs, and receives a Block Acknowledgement (BA) from each one of the STAs. For OFDMA uplink transmissions, an STA sends a signaling requesting protection of a transmission channel from access by the AP. The STA then sends, to the AP, a frame indicating start of OFDMA transmission by the STA, and receives, from the AP, an OFDMA Begin Receive (OBR) frame, which is sent by the AP to participating STAs. The STA then sends an OFDMA PPDU and a BAR to the AP, and receives a BA in return.