Acknowledgement of transmissions in a wireless local area network

1. A method for acknowledging a data unit, the method comprising:

receiving, at a first communication device, one or more aggregate medium access control (MAC) data units from respective one or more second communication devices, respective ones of the one or more aggregate MAC data units including respective sets of multiple MAC data units from respective ones of the one or more second communication devices;

generating, at the first communication device, one or more acknowledgement information fields corresponding to the one or more second communication devices, including generating a first acknowledgement information field corresponding to a particular second communication device of the one or more second communication devices, wherein the first acknowledgement information field includes (i) a block acknowledgment starting sequence control field having (a) a first subfield that indicates a sequence number corresponding to a first one of the multiple MAC data units being acknowledged in the first acknowledgement information field and (b) a second subfield that includes a length indication that indicates a length of an acknowledgement field, and (ii) the acknowledgment field of the indicated length, wherein the acknowledgement field includes respective acknowledgement information for at least some of the multiple MAC data units received from the particular second communication device, and wherein the length of the acknowledgement field is determined based at least in part on a maximum number of MAC data units limited by a buffer size negotiated in an acknowledgement setup procedure previously conducted between the first communication device and the particular second communication device;

generating, at the first communication device, an acknowledgement data unit to include the one or more one or more acknowledgement information fields; and

transmitting the acknowledgment data unit from the first communication device to the one or more second communication devices.

2. The method of claim 1 , wherein generating the one or more acknowledgement information fields further includes generating a second acknowledgement information field corresponding to the particular second communication device, wherein i) the first acknowledgement information field is generated to acknowledge a first subset of the multiple MAC data units received from the particular second communication device and ii) the second acknowledgement information is generated to acknowledge a second subset of the multiple MAC data units received from the particular second communication device.

3. The method of claim 2 , wherein the first subset of the multiple MAC data units and the second subset of the multiple MAC data units comprise MAC data units of a first traffic class.

4. The method of claim 2 , wherein generating the acknowledgement data unit includes generating the acknowledgement data unit such that the second acknowledgement information field corresponding to the particular second communication device immediately follows the first acknowledgement information field corresponding to the particular second communication device.

5. The method of claim 3 , wherein generating the one or more acknowledgement information fields further includes generating a third acknowledgement information field corresponding to the particular second communication device, wherein the third acknowledgement information field is generated to acknowledge a third subset of the multiple MAC data units received from the particular second communication device, the third subset of the multiple MAC data units comprising MAC data units of a second traffic different from the first traffic class.

6. The method of claim 2 , wherein generating the one or more acknowledgement information fields further includes generating a third acknowledgement information field corresponding to an additional second communication device of the one or more second communication devices, wherein the third acknowledgement information field is generated to acknowledge at least some of the multiple MAC data units received from the additional second communication device.

7. The method of claim 1 , wherein the first acknowledgement information field further includes an additional length indication, wherein a value of the length indication is interpreted based on a value of the additional length indication.

8. The method of claim 7 , wherein the length indication is interpreted i) to indicate a first length if the additional length indication is set to a first value, the first length selected from a first set of predetermined lengths or ii) to indicate a second length, different from the first length, if the additional length indication is set to a second value, the second length selected from a second set of predetermined length different from the first set of predetermined lengths.

9. The method of claim 1 , wherein the acknowledgement field includes a bitmap of the indicated length, wherein respective bits of the bitmap indicate acknowledgments of respective MAC data unit of the at least some of the multiple MAC data units received from the particular second communication device.

10. The method of claim 1 , wherein

the particular second communication device conforms to a first communication protocol that supports aggregation of a first maximum number of MAC data units in an aggregate MAC data unit, and

generating the one or more acknowledgement information fields includes generating

i) a single acknowledgement information field corresponding to an additional second communication device of the one or more second communication devices, the additional second communication device conforming to a second communication protocol that supports aggregation of a second maximum number of MAC data units in an aggregate MAC data unit, wherein the second maximum number of MAC data units is smaller than the first maximum number of MAC data units, and

ii) multiple acknowledgement information fields corresponding to the particular second communication device, wherein respective ones of the multiple acknowledgement fields a) conform to the first communication protocol and ii) do not exceed an acknowledgement field length that corresponds to the second maximum number of MAC data units supported by the second communication protocol.

11. A first communication device, comprising:

a network interface having one or more integrated circuits configured to

receive one or more aggregate medium access control (MAC) data units from respective one or more second communication devices, respective ones of the one or more aggregate MAC data units including respective sets of multiple MAC data units from respective ones of the one or more second communication devices,

generate one or more acknowledgement information fields corresponding to the one or more second communication devices, including generating a first acknowledgement information field corresponding to a particular second communication device of the one or more second communication devices, wherein the first acknowledgement information field includes (i) a block acknowledgment starting sequence control field having (a) a first subfield that indicates a sequence number corresponding to a first one of the multiple MAC data units being acknowledged in the first acknowledgement information field and (b) a second subfield that includes a length indication that indicates a length of an acknowledgement field, and (ii) the acknowledgment field of the indicated length, wherein the acknowledgement field includes respective acknowledgement information for at least some of the multiple MAC data units received from the particular second communication device, and wherein the length of the acknowledgement field is determined based at least in part on a maximum number of MAC data units limited by a buffer size negotiated in an acknowledgement setup procedure previously conducted between the first communication device and the particular second communication device,

generate an acknowledgement data unit to include at least the first acknowledgement information field, and

cause the acknowledgment data unit to be transmitted to the one or more second communication devices.

12. The first communication device of claim 11 , wherein the one or more integrated circuits are further configured to generate a second acknowledgement information field corresponding to the particular second communication device, wherein i) the first acknowledgement information field corresponding to the is generated to acknowledge a first subset of the multiple MAC data units received from the particular second communication device and ii) the second acknowledgement information is generated to acknowledge a second subset of the multiple MAC data units received from the particular second communication device.

13. The first communication device of claim 12 , wherein the first subset of the multiple MAC data units and the second subset of the multiple MAC data units comprise MAC data units of a first traffic class.

14. The first communication device of claim 12 , wherein the one or more integrated circuits are configured to generated the acknowledgement data unit such that the second acknowledgement information field corresponding to the particular second communication device immediately follows the first acknowledgement information field corresponding to the particular second communication device.

15. The first communication device of claim 13 , wherein the one or more integrated circuits are further configured to generate a third acknowledgement information field corresponding to the particular second communication device, wherein the third acknowledgement information field is generated to acknowledge a third subset of the multiple MAC data units received from the particular second communication device, the third subset of the multiple MAC data units comprising MAC data units of a second traffic different from the first traffic class.

16. The first communication device of claim 12 , wherein the one or more integrated circuits are further configured to generate a third acknowledgement information field corresponding to an additional second communication device of the one or more second communication devices, wherein the third acknowledgement information field is generated to acknowledge at least some of the multiple MAC data units received from the additional second communication device.

17. The first communication device of claim 11 , wherein the first acknowledgement information field further includes an additional length indication, wherein a value of the length indication is interpreted based on a value of the additional length indication.

18. The first communication device of claim 17 , wherein the length indication is interpreted i) to indicate a first length if the additional length indication is set to a first value, the first length selected from a first set of predetermined lengths or ii) to indicate a second length, different from the first length, if the additional length indication is set to a second value, the second length selected from a second set of predetermined length different from the first set of predetermined lengths.

19. The first communication device of claim 11 , wherein the acknowledgement field includes a bitmap of the indicated length, wherein respective bits of the bitmap indicate acknowledgments of respective MAC data unit of the at least some of the multiple MAC data units received from the particular second communication device.

20. The first communication device of claim 11 , wherein

the particular second communication device conforms to a first communication protocol that supports aggregation of a first maximum number of MAC data units in an aggregate MAC data unit, and

the one or more integrated circuits are configured to generate the one or more acknowledgement information fields at least by generating

i) a single acknowledgement information field corresponding to an additional second communication device of the one or more second communication devices, the additional second communication device conforming to a second communication protocol that supports aggregation of a second maximum number of MAC data units in an aggregate MAC data unit, wherein the second maximum number of MAC data units is smaller than the first maximum number of MAC data units, and

ii) multiple acknowledgement information fields corresponding to the particular second communication device, wherein respective ones of the multiple acknowledgement fields a) conform to the first communication protocol and ii) do not exceed an acknowledgement field length that corresponds to the second maximum number of MAC data units supported by the second communication protocol.