Techniques for flexible and efficient beamforming

A method comprising:

• generating, at a first device, a first data unit to include training data for a first beamforming training session between the first device and a second device;
• generating, at the first device, a first field of the first data unit, wherein the first field includes an indication of a first number of training data units to be transmitted by the first device to the second device during a second beamforming training session to occur after the first beamforming training session, wherein the first field of the first data unit corresponds to a request for the second device to participate in the second beamforming training session, and wherein the second beamforming training session corresponds to transmit beamforming training;
• generating, at the first device, a second field of the first data unit, wherein the second field includes an indication of a second number of training data units that are requested, by the first device, to be transmitted by the second device to the first device during a third beamforming training session to occur after the first beamforming training session, wherein the second field of the first data unit corresponds to a request for the second device to participate in the third beamforming training session, and wherein the third beamforming training session corresponds to receive beamforming training;
• generating, at the first device, a third field of the first data unit, wherein the third field includes an indication of whether a request by the second device for the first device to participate in a fourth beamforming training session is accepted by the first device, wherein the request to participate in the fourth beamforming training session was transmitted by the second device at a time prior to the first beamforming training session, and wherein the fourth beamforming training session corresponds to transmit beamforming training;
• generating, at the first device, a fourth field of the first data unit, wherein the fourth field includes an indication of whether a request by the second device for the first device to participate in a fifth beamforming training session is accepted by the first device, wherein the request to participate in the fifth beamforming training session was transmitted by the second device at a time prior to the first beamforming training session, and wherein the fifth beamforming training session corresponds to receive beamforming training;
• processing, at the first device, a second data unit received at the first device, wherein the second data unit includes a response, by the second device, to the request, in the first data unit, for the second device to participate in the second beamforming training session, wherein processing the second data unit includes determining whether the request for the second device to participate in the second training session was accepted by the second device based on a first field of the second data unit, wherein the first field of the second data unit is a single bit, wherein a first value of the first field indicates that the request for the second training session was accepted by the second device, and wherein a second value of the first field indicates that the request for the second training session was rejected by the second device;
• and
• in response to determining that the request to participate in the second beamforming training session was accepted by the second device, causing the first number of beamforming training data units to be transmitted by the first device during the second beamforming training session.

An apparatus comprising:

• a beamforming training (BFT) control information element (IE) generator to generate a BFT control IE to be transmitted during a first beamforming training session, wherein the BFT control IE generator is configured to generate:
• a first field of the BFT control IE that specifies a first number of training data units to be communicated from a first device to a second device during a second beamforming training session to occur after the first beamforming training session, wherein the first field corresponds to a request for the second device to participate in the second beamforming training session, and wherein the second beamforming training session corresponds to transmit beamforming training, and
• a second field of the BFT control IE that specifies whether a request for the first device to participate in a third beamforming training session is accepted by the first communication device, and wherein the request to participate in the third beamforming training session was transmitted by the second device at a time prior to the first beamforming training session;
• a transmit beam refinement controller to generate a first value if the first communication device supports beam refinement, and to generate a second value if the first communication device does not support beam refinement, wherein the transmit beam refinement controller is coupled to the BFT control IE generator to supply one of the first value or the second value for use in the second field of the BFT control IE;
• wherein the apparatus further comprises:
• a frame generator configured to generate a first communication frame to be transmitted by the first device during the first beamforming training session, wherein the first communication frame includes the BFT control IE and training data for the first beamforming training session;
• and
• a transmit beamforming training controller configured to:
• process a second communication frame received at the first device, wherein the second communication frame includes a response, by the second device, to the request, in the first communication frame, for the second device to participate in the second beamforming training session, wherein processing the second data unit includes determining whether the request for the second device to participate in the second training session was accepted by the second device based on a first field of the second communication frame, and
• in response to determining that the request to participate in the second beamforming training session was accepted by the second device, causing the first number of training data units to be transmitted by the first device during the second beamforming training session.