Patent ID: 8363627

Claim:
A method for transmitting a control frame by a wireless device, the method comprising: determining, by the wireless device, that the control frame is either in response to a previous frame having been received, known as a control response frame, or is intended to elicit a response; where the control frame is a control response frame: transmitting the control response frame using a high-throughput (HT) physical (PHY) layer protocol data unit (PDU) if the previous frame includes a training request; transmitting the control response frame using the HT PHY PDU if the previous frame is a request-to-send frame carried in a HT PHY PDU; transmitting the control response frame using the HT PHY PDU if the previous frame is sent at a spatial time block coding (STBC) rate while a dual clear-to-send protection bit is set; and otherwise, transmitting the control response frame using a non-HT PHY PDU; and where the control frame is not a control response frame: transmitting the control frame using the HT PHY PDU if the control frame is intended for sounding; transmitting the control frame using the HT PHY PDU if the control frame contains a legacy signal duration value; transmitting the control frame using the HT PHY PDU if the control frame is to be sent at an STBC rate; and otherwise, transmitting the control frame using the non-HT PHY PDU.