A signal field is generated to include (i) a field to indicate that a physical layer (PHY) data unit is a control frame, and (ii) one or more of a frame control field, a receiver address (RA) field, and a cyclic redundancy check (CRC) field. A PHY data payload (i) that includes one or more of a service field, a transmitter address (TA) field, a network ID field, and a CRC field, and (ii) that omits an RA field is generated. The PHY data unit is generated to include (i) a preamble, (ii) a PHY header having the SIG field, and (iii) the PHY data payload. The PHY data unit is transmitted.