Rather than using a large number of transceivers (transmitter/receiver pairs) operating in parallel, Access Points with multiple channels are used to aggregate, or stack, transmitted response communications, e.g., transmitting multiple acknowledgements (ACKs) in a single packet to one or more sources of received packets. The method includes sending on a plurality of channels, by each of a plurality of respective first nodes, a communication to a second node, receiving on the plurality of channels, by the second node, the communication from each of the plurality of first nodes and sending, by the second node, a transmission that contains a response to each communication that was successfully received from each of the plurality of first nodes. The response to each of the plurality of first nodes is part of a single message sent by the second node.