Patent ID: 8238274

Claim:
A wireless communication device comprising: a wireless communication unit to transmit a wireless beamforming calibration announcement packet to another wireless communication device to announce both first and second null-data-packets to be exchanged between said wireless communication unit and the other wireless communication device, to transmit the first null-data-packet after transmitting said announcement packet, and to receive the second null-data-packet from the other device immediately successive to the first null-data-packet and prior to receiving another communication from the other wireless communication device, wherein, prior to transmitting said first null-data-packet, said wireless communication unit is to receive from the other wireless communication device a response packet, and wherein both said beamforming calibration announcement packet and said response packet comprise an announcement bit, the announcement bit of said beamforming calibration announcement packet having a first value, and the announcement bit of said response packet having a second value, different from said first value.