Trigger-based single user uplink transmission

A method, comprising:

• receiving, at a first communication device from a second communication device, a trigger frame;
• generating, at the first communication device, a single-user (SU) physical layer (PHY) protocol data unit that includes a PHY protocol payload, wherein the PHY protocol payload include information other than information that acknowledges a previous transmission from the second communication device;
• and
• in response to the trigger frame, transmitting the SU PHY protocol data unit from the first communication device to the second communication device, wherein the first communication device transmits the SU PHY protocol data unit prior to the first communication device transmitting any other PHY protocol data unit after receiving the trigger frame.