Patent ID: 8116249

Claim:
A wireless communication system which performs wireless communication between one access point and a plurality of wireless terminals; wherein the access point is configured to transmit a plurality of data frames to the plurality of wireless terminals by one communication of multicast communication and broadcast communication, and configured to request Block ACK frames as affirmative acknowledgment; each of the plurality of wireless terminals is configured to generate the Block ACK frame and configured to return the Block ACK frame to the access point and the wireless terminals other than the wireless terminal itself by one communication of the multicast communication and the broadcast communication, in a case where the access point requests the Block ACK frame; wherein each of the plurality of wireless terminals is configured to compare a Block ACK Bitmap field included in the Block ACK frame transmitted from the wireless terminals other than the wireless terminal itself with a Block ACK Bitmap field included in a Block ACK frame generated by the wireless terminal itself; configured to reduce the size of the Block ACK Bitmap field of the Block ACK frame generated by the wireless terminal itself in a case where both the fields match with each other; and configured to store, in the reduced Block ACK Bitmap field, data to identify a transmitter wireless terminal in which the Block ACK Bitmap field matches.