Efficient uplink SDMA operation

1. A computer-implemented method comprising:

receiving, at a first wireless device, a polling frame including a transmission right granted to each of a plurality of wireless devices belonging to a first group, the first group including the first wireless device;

transmitting, by the first wireless device, a first acknowledgement frame during a period determined based on the transmission right, wherein the same period is assigned for transmission to each of the plurality of wireless devices belonging to the first group; and

receiving, at a second wireless device, another polling frame including another transmission right granted to each of a plurality of wireless devices belonging to a second group, the second group including the second wireless device, wherein the other transmission right defines another same period assigned for transmission to each of the plurality of wireless devices belonging to the second group,

wherein the period assigned to the wireless devices belonging to the first group is different than the other period assigned to the wireless devices belonging to the second group.

2. The computer-implemented method of claim 1 , wherein a timing for transmitting the first acknowledgement frame is determined based on the length of the first acknowledgement frame.

3. The computer-implemented method of claim 1 , wherein the first acknowledgement frame includes a queue size of a first set of buffered traffic.

4. The computer-implemented method of claim 1 , further comprising:

transmitting, by the first wireless device, a first set of buffered traffic during the period associated with the first group.

5. The computer-implemented method of claim 4 , wherein the first set of buffered traffic is transmitted simultaneously with a second set of buffered data transmitted by the second wireless device.

6. The computer-implemented method of claim 5 , wherein the first and second sets of buffered traffic are transmitted using Spatial Division Multiple Access (SDMA).

7. The computer-implemented method of claim 1 , wherein:

the first group further includes a third wireless device, and

the first acknowledgement frame is transmitted by the first wireless device simultaneously with a third acknowledgement frame transmitted by the third wireless device.

8. The computer-implemented method of claim 7 , wherein the first and third acknowledgement frames are transmitted using Spatial Division Multiple Access (SDMA).

9. A computer-implemented method comprising:

transmitting, to a group of wireless devices, a polling frame including a transmission right granted to each of the wireless devices belonging to the group, wherein the transmission right defines a same period assigned to each of the wireless devices belonging to the group; and

receiving frames transmitted using Spatial Division Multiple Access (SDMA) from at least one of the wireless devices belonging to the group; and

transmitting, to another group of wireless devices, another polling frame including another transmission right granted to each of the wireless devices belonging to the other group,

wherein the other transmission right defines another same period assigned to each of the wireless devices belonging to the other group, wherein the period assigned to the wireless devices belonging to the group is different than the other period assigned to the wireless devices belonging to the other group.

10. The computer-implemented method of claim 9 , wherein the same period is a period during which the wireless devices are allowed to transmit buffered traffic.

11. The computer-implemented method of claim 10 , wherein said receiving includes receiving a plurality of frames from a plurality of wireless devices belonging to the group; and

the method further comprising:

transmitting acknowledgement frames to the group of wireless devices in response to the receipt of the longest buffered traffic.

12. The computer-implemented method of claim 11 , wherein the acknowledgement frames are transmitted using downlink SDMA or downlink OFDMA.

13. A device comprising a processor configured to:

transmit, to a group of wireless devices, a polling frame including a transmission right granted to each of the wireless devices belonging to the group, wherein the transmission right defines a same period assigned to each of the wireless devices belonging to the group; and

receive frames transmitted using Spatial Division Multiple Access (SDMA) from at least one of the wireless devices belonging to the group;

transmit, to another group of wireless devices, another polling frame including another transmission right granted to each of the wireless devices belonging to the other group,

wherein the other transmission right defines another same period assigned to each of the wireless devices belonging to the other group, wherein the period assigned to the wireless devices belonging to the group is different than the other period assigned to the wireless devices belonging to the other group.

14. The device of claim 13 , wherein the same period is a period during which the wireless devices are allowed to transmit buffered traffic.

15. The device of claim 14 , wherein the processor is further configured to:

receive a plurality of frames from a plurality of wireless devices belonging to the group of wireless devices; and

transmit acknowledgement frames to the group of wireless devices in response to the receipt of the longest buffered traffic.

16. The device of claim 15 , wherein the acknowledgement frames are transmitted using downlink SDMA or downlink OFDMA.

17. A non-transitory computer-readable medium comprising computer-readable code physically embodied thereon which, when executed by a processor, causes the processor to perform a plurality of operations comprising:

transmitting, to a group of wireless devices, a polling frame including a transmission right granted to each of the wireless devices belonging to the group, wherein the transmission right defines a same period assigned to each of the wireless devices belonging to the group;

receiving frames transmitted using Spatial Division Multiple Access (SDMA) from at least one of the wireless devices belonging to the group; and

transmitting, to another group of wireless devices, another polling frame including another transmission right granted to each of the wireless devices belonging to the other group,

wherein the other transmission right defines another same period assigned to each of the wireless devices belonging to the other group, wherein the period assigned to the wireless devices belonging to the group is different than the other period assigned to the wireless devices belonging to the other group.

18. The computer-readable medium of claim 17 , wherein the same period is a period during which the wireless devices are allowed to transmit buffered traffic.

19. The computer-readable medium of claim 18 , wherein said receiving includes receiving a plurality of frames from a plurality of wireless devices belonging to the group, the plurality of operations further comprising transmitting acknowledgement frames to the group of wireless devices in response to the receipt of the longest buffered traffic.

20. The computer-readable medium of claim 19 , wherein the acknowledgement frames are transmitted using downlink SDMA or downlink OFDMA.

21. A non-transitory computer-readable medium comprising computer-readable code physically embodied thereon which, when executed by a processor, causes the processor to perform a plurality of operations comprising:

receiving, at a first wireless device, a polling frame including a transmission right granted to each of a plurality of wireless devices belonging to a first group, the first group including the first wireless device;

transmitting, by the first wireless device, a first acknowledgement frame during a period determined based on the transmission right, wherein the same period is assigned for transmission to each of the plurality of wireless devices belonging to the first group; and

receiving, at a second wireless device, another polling frame including another transmission right granted to each of a plurality of wireless devices belonging to a second group, the second group including the second wireless device, wherein the other transmission right defines another same period assigned for transmission to each of the plurality of wireless devices belonging to the second group,

wherein the period assigned to the wireless devices belonging to the first group is different than the other period assigned to the wireless devices belonging to the second group.

22. The computer-readable medium of claim 21 , wherein the first group further includes a third wireless device, and the first acknowledgement frame is transmitted by the first wireless device simultaneously with a third acknowledgement frame transmitted by the third wireless device.

23. The computer-readable medium of claim 22 , wherein the first and third acknowledgement frames are transmitted using Spatial Division Multiple Access (SDMA).

24. The computer-readable medium of claim 21 , wherein a timing for transmitting the first acknowledgement frame is determined based on the length of the first acknowledgement frame.

25. The computer-readable medium of claim 21 , wherein the first acknowledgement frame includes a queue size of a first set of buffered traffic.

26. The computer-readable medium of claim 21 , wherein the plurality of operations further comprises:

transmitting, by the first wireless device, a first set of buffered traffic during the period associated with the first group.

27. The computer-readable medium of claim 26 , wherein the first set of buffered traffic is transmitted simultaneously with a second set of buffered data transmitted by the second wireless device.

28. The computer-readable medium of claim 27 , wherein the first and second sets of buffered traffic are transmitted using Spatial Division Multiple Access (SDMA).