Patent ID: 8842587

Claim:
A method comprising: transmitting a calibration initiation frame from a first wireless communication device to a second wireless communication device that comprises a single space-time stream transmitter via a wireless communication medium, the calibration initiation frame including an acknowledgement policy parameter set to request the second wireless communication device to return an acknowledgement frame after the second wireless communication device receives the calibration initiation frame; receiving at the first wireless communication device the acknowledgement frame sent from the second wireless communication device after the second wireless communication device receives the calibration initiation frame, wherein the second communication device is not configured to transmit a null data packet (NDP); transmitting a null data packet (NDP) frame from the first wireless communication device to the second wireless communication device after receiving the acknowledgement frame; receiving at the first wireless communication device a second acknowledgement frame sent from the second wireless communication device after the second wireless communication device receives the NDP frame; performing beamforming calibration of a wireless communication channel between the first wireless communication device and the second wireless communication device based on the second acknowledgement frame; and transmitting a calibration complete frame from the first wireless communication device to the second wireless communication device after receiving the second acknowledgement frame.