As part of a beamforming training procedure, a first communication device transmits a beamforming training packet. The first device then receives a plurality of respective beamforming feedback packets from a plurality of second communication devices. The first device then uses the plurality of beamforming feedback packets to select a group of multiple communication devices from among the plurality of second communication devices, wherein the group is selected for simultaneous transmissions to the first communication device. The first device then transmits a synchronization signal to the group to prompt second communication devices in the group to simultaneously transmit to the first communication device at a particular time. The first device then receives simultaneous transmissions from the group responsive to the synchronization signal.