METHOD AND APPARATUS FOR TRANSMITTING ACKNOWLEDGEMENTS IN RESPONSE TO RECEIVED FRAMES

1 . An access point (AP) in a wireless communication network, comprising:

at least one processor configured to establish a group of stations;

a receiver configured to receive packets from the group of stations over a delay period;

the at least one processor configured to generate a delayed multi-user acknowledgement (ACK) frame based on successful receipt of the packets over the delay period; and

a transmitter configured to transmit the delayed multi-user ACK frame to the group of stations following the delay period.

2 . The AP of claim 1 , wherein the delayed multi-user ACK frame is a block ACK frame configured to acknowledge the packets successfully received from at least one station belonging to the group of stations.

3 . The AP of claim 1 , wherein the delayed multi-user ACK frame includes an indication indicating whether the delayed multi-user ACK frame is a block ACK frame or a non-block ACK frame.

4 . The AP of claim 1 , wherein the delay period expires in response to receiving an ACK request from at least one station of the group of stations or in response to an expiration of a delay timer corresponding to the delay period.

5 . The AP of claim 1 , wherein:

the receiver is configured to receive a capability indication from each of a plurality of stations indicating a capability of receiving delayed multi-user ACK frames, and

the at least one processor is configured to establish the group of stations based on receipt of the capability indications.

6 . The AP of claim 5 , wherein:

the transmitter is configured to transmit a response message to each of the plurality of stations from which the capability indication is affirmative, wherein the response message includes configuration information associated with the delayed multi-user ACK frame.

7 . The AP of claim 1 , wherein:

the delayed multi-user ACK frame includes an ACK field for each station belonging to the group of stations, and

each ACK field includes at least one traffic identifier and a traffic identifier ACK for a corresponding traffic identifier of the at least one traffic identifier, wherein the traffic identifier ACK acknowledges at least one packet associated with the corresponding traffic identifier.

8 . The AP of claim 1 , wherein:

the at least one processor is configured to arrange a plurality of stations belonging to the group of stations into a sequential order, and

the delayed multi-user ACK frame includes a plurality of ACK fields arranged in the sequential order, wherein each ACK field of the plurality of ACK fields corresponds to a different station of the plurality of stations.

9 . The AP of claim 1 , further comprising a memory configured to accumulate the received packets from the group of stations over the delay period.

10 . A method for use in an access point (AP) in a wireless communication network, the method comprising:

establishing a group of stations;

receiving packets from the group of stations over a delay period;

generating a delayed multi-user acknowledgement (ACK) frame based on successful receipt of the packets over the delay period; and

transmitting the delayed multi-user ACK frame to the group of stations following the delay period.

11 . The method of claim 10 , wherein the delayed multi-user ACK frame is a block ACK frame configured to acknowledge the packets successfully received from at least one station belonging to the group of stations.

12 . The method of claim 10 , wherein the delayed multi-user ACK frame includes an indication indicating whether the delayed multi-user ACK frame is a block ACK frame or a non-block ACK frame.

13 . The method of claim 10 , wherein the delay period expires in response to receiving an ACK request from at least one station of the group of stations or in response to an expiration of a delay timer corresponding to the delay period.

14 . The method of claim 10 , further comprising:

receiving a capability indication from each of a plurality of stations indicating a capability of receiving delayed multi-user ACK frames, and

establishing the group of stations based on receipt of the capability indications.

15 . The method of claim 14 , further comprising:

transmitting a response message to each station belonging to the group of stations from which the capability indication is affirmative, wherein the response message includes configuration information associated with the delayed multi-user ACK frame.

16 . The method of claim 10 , wherein:

the delayed multi-user ACK frame includes an ACK field for each station belonging to the group of stations, and

each ACK field includes at least one traffic identifier and a traffic identifier ACK for a corresponding traffic identifier of the at least one traffic identifier, wherein the traffic identifier ACK acknowledges at least one packet associated with the corresponding traffic identifier.

17 . The method of claim 10 , further comprising:

arranging a plurality of stations belonging to the group of stations into a sequential order, and

wherein the delayed multi-user ACK frame includes a plurality of ACK fields arranged in the sequential order, wherein each ACK field of the plurality of ACK fields corresponds to a different station of the plurality of stations.

18 . The method of claim 10 , further comprising:

accumulating the received packets over the delay period; and generating the delayed multi-user ACK frame based on successful receipt of the accumulated packets.