Trigger frame format for orthogonal frequency division multiple access (OFDMA) communication

A method for communicating in a wireless communication network, the method comprising:

• generating, at a first communication device, multiple trigger frames to trigger an uplink orthogonal frequency multiple access (OFDMA) transmission by multiple second communication devices, including generating
• (i) a broadcast trigger frame that includes information to indicate transmission parameters for a first subset of the second communication devices and
• (ii) one or more unicast trigger frames, wherein each of the one or more unicast trigger frame includes information to indicate transmission parameters for a particular second communication device in a second subset of the second communication devices;
• transmitting, with the first communication device, the multiple trigger frames to the multiple second communication devices in a single downlink OFDMA physical layer (PHY) protocol data unit (PPDU), including
• (i) transmitting the broadcast trigger frame to the first subset of the second communication devices, wherein the broadcast trigger frame is transmitted in a first frequency portion of the single downlink OFDMA PPDU to the multiple second communication devices, and
• (ii) transmitting the one or more unicast trigger frames to the second subset of the second communication devices, wherein one or more respective unicast trigger frames are transmitted in one or more respective second frequency portions of the single downlink OFDMA PPDU, the respective second frequency portions corresponding with the respective second communication devices in the second subset, wherein the one or more second frequency portions do not overlap in frequency with the first frequency portion;
• and
• receiving, at the first communication device, the triggered uplink OFDMA transmission, wherein the triggered uplink OFDMA transmission includes respective transmissions from the multiple second communication devices.