PROTECTION MECHANISMS FOR MULTI-USER MIMO TRANSMISSIONS

• US 20120087316A1
• Filed: 03/30/2011
• Published: 04/12/2012
• Est. Priority Date: 03/31/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Merlin, Simone, Abraham, Santosh Paul, Sampath, Hemanth, Wentink, Maarten Menzo, Taghavi Nasrabadi, Mohammad Hossein, Vermani, Sameer, Van Nee, Didier Johannes Richard, Jones, Vincent Knowles IV
• Granted Patent: US 8,989,066 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

Certain aspects of the present disclosure relate to techniques for medium reservation in the case of multi-user (MU) communications. Multiple mechanisms are supported for protecting MU transmissions, wherein appropriate control messages can be exchanged between an access point and served user stations before transmitting downlink data packets.

Claims

1. An apparatus for wireless communications, comprising:

a transmitter configured to transmit one or more reservation messages, each of the one or more reservation messages being destined to a different apparatus of a plurality of apparatuses to reserve a medium for data communication; and

a receiver configured to receive one or more confirmation messages, each of the one or more confirmation messages was transmitted from the different apparatus in response to that reservation message, wherein

the transmitter is also configured to transmit, in response to the one or more confirmation messages, data over the medium to the apparatuses.

2. The apparatus of claim 1, wherein:

the reservation messages are transmitted sequentially, and

the confirmation messages are received sequentially.

3. The apparatus of claim 2, wherein transmitting each of the reservation messages immediately precedes transmission of a different one of the confirmation messages.

4. The apparatus of claim 1, wherein:

each of the one or more reservation messages has a format substantially the same as an IEEE 802.11 request-to-send (RTS) message format, and

each of the one or more confirmation messages has a format substantially the same as an IEEE 802.11 clear-to-send (CTS) message format.

5. The apparatus of claim 1, wherein each of the one or more reservation messages comprises Network Allocation Vector (NAV) information.

6. The apparatus of claim 1, further comprising:

a circuit configured to select the different apparatus for transmitting that reservation message based on the different apparatus being a destination for a first packet in a queue associated with a traffic belonging to a class of traffic that won contention to access the medium.

7. The apparatus of claim 1, further comprising:

a circuit configured to select the different apparatus for transmitting that reservation message based on a number of collisions during data communication over the medium associated with each of the apparatuses, and wherein

the different apparatus has the highest number of collisions among the numbers of collisions associated with all the apparatuses.

8. The apparatus of claim 1, wherein the data transmitted to the apparatuses comprise a Multi User Multiple Input Multiple Output Very High Throughput Physical layer convergence procedure Protocol Data Unit (MU-MIMO VHT PPDU).

9. A method for wireless communications, comprising:

transmitting one or more reservation messages, each of the one or more reservation messages being destined to a different apparatus of a plurality of apparatuses to reserve a medium for data communication;

receiving one or more confirmation messages, each of the one or more confirmation messages was transmitted from the different apparatus in response to that reservation message; and

transmitting, in response to the one or more confirmation messages, data over the medium to the apparatuses.

10. The method of claim 9, wherein:

the reservation messages are transmitted sequentially, and

the confirmation messages are received sequentially.

11. The method of claim 10, wherein transmitting each of the reservation messages immediately precedes transmission of a different one of the confirmation messages.

12. The method of claim 9, wherein:

each of the one or more reservation messages has a format substantially the same as an IEEE 802.11 request-to-send (RTS) message format, and

each of the one or more confirmation messages has a format substantially the same as an IEEE 802.11 clear-to-send (CTS) message format.

13. The method of claim 9, wherein each of the one or more reservation messages comprises Network Allocation Vector (NAV) information.

14. The method of claim 9, further comprising:

selecting the different apparatus for transmitting that reservation message based on the different apparatus being a destination for a first packet in a queue associated with a traffic belonging to a class of traffic that won contention to access the medium.

15. The method of claim 9, further comprising:

selecting the different apparatus for transmitting that reservation message based on a number of collisions during data communication over the medium associated with each of the apparatuses, and wherein

the different apparatus has the highest number of collisions among the numbers of collisions associated with all the apparatuses.

16. The method of claim 9, wherein the data transmitted to the apparatuses comprise a Multi User Multiple Input Multiple Output Very High Throughput Physical layer convergence procedure Protocol Data Unit (MU-MIMO VHT PPDU).

17. An apparatus for wireless communications, comprising:

means for transmitting one or more reservation messages, each of the one or more reservation messages being destined to a different apparatus of a plurality of apparatuses to reserve a medium for data communication; and

means for receiving one or more confirmation messages, each of the one or more confirmation messages was transmitted from the different apparatus in response to that reservation message, wherein

the means for transmitting is further configured to transmit, in response to the one or more confirmation messages, data over the medium to the apparatuses.

18. The apparatus of claim 17, wherein:

the reservation messages are transmitted sequentially, and

the confirmation messages are received sequentially.

19. The apparatus of claim 18, wherein transmitting each of the reservation messages immediately precedes transmission of a different one of the confirmation messages.

20. The apparatus of claim 17, wherein:

each of the one or more reservation messages has a format substantially the same as an IEEE 802.11 request-to-send (RTS) message format, and

each of the one or more confirmation messages has a format substantially the same as an IEEE 802.11 clear-to-send (CTS) message format.

21. The apparatus of claim 17, wherein each of the one or more reservation messages comprises Network Allocation Vector (NAV) information.

22. The apparatus of claim 17, further comprising:

means for selecting the different apparatus for transmitting that reservation message based on the different apparatus being a destination for a first packet in a queue associated with a traffic belonging to a class of traffic that won contention to access the medium.

23. The apparatus of claim 17, further comprising:

means for selecting the different apparatus for transmitting that reservation message based on a number of collisions during data communication over the medium associated with each of the apparatuses, and wherein

the different apparatus has the highest number of collisions among the numbers of collisions associated with all the apparatuses.

24. The apparatus of claim 17, wherein the data transmitted to the apparatuses comprise a Multi User Multiple Input Multiple Output Very High Throughput Physical layer convergence procedure Protocol Data Unit (MU-MIMO VHT PPDU).

25. A computer-program product for wireless communications, comprising a computer-readable medium comprising instructions executable to:

transmit one or more reservation messages, each of the one or more reservation messages being destined to a different apparatus of a plurality of apparatuses to reserve a medium for data communication;

receive one or more confirmation messages, each of the one or more confirmation messages was transmitted from the different apparatus in response to that reservation message; and

transmit, in response to the one or more confirmation messages, data over the medium to the apparatuses.

26. An access point, comprising:

at least one antenna;

a transmitter configured to transmit one or more reservation messages via the at least one antenna, each of the one or more reservation messages being destined to a different access terminal of a plurality of access terminals to reserve a medium for data communication; and

a receiver configured to receive one or more confirmation messages via the at least one antenna, each of the one or more confirmation messages was transmitted from the different access terminal in response to that reservation message, wherein

the transmitter is also configured to transmit, via the at least one antenna in response to the one or more confirmation messages, data over the medium to the access terminals.

27. An apparatus for wireless communications, comprising:

a receiver configured to receive, at the apparatus of a plurality of apparatuses, a reservation message from one or more reservation messages, each of the one or more reservation messages being destined to a different one of the apparatuses for reserving a medium for data communication; and

a transmitter configured to transmit a confirmation message in response to the reservation message, wherein

the receiver is also configured to receive data dedicated to the apparatus, the data being transmitted over the medium.

28. The apparatus of claim 27, wherein the confirmation message is transmitted according to a transmission order specified in the reservation message.

29. The apparatus of claim 27, further comprising:

a circuit configured to count a number of one or more other confirmation messages previously transmitted from one or more other apparatuses of the plurality of apparatuses to determine when to transmit the confirmation message.

30. The apparatus of claim 29, wherein the circuit is also configured to:

detect the one or more other confirmation messages.

31. The apparatus of claim 27, wherein the confirmation message is transmitted immediately after receiving the reservation message.

32. The apparatus of claim 27, wherein the confirmation message is transmitted according to a scheduled time specified in the reservation message.

33. The apparatus of claim 27, wherein:

the reservation message has a format substantially the same as an IEEE 802.11 request-to-send (RTS) message format, and

the confirmation message has a format substantially the same as an IEEE 802.11 clear-to-send (CTS) message format.

34. The apparatus of claim 27, wherein the confirmation message comprises Network Allocation Vector (NAV) information specified in the received reservation message.

35. A method for wireless communications, comprising:

receiving, at an apparatus of a plurality of apparatuses, a reservation message from one or more reservation messages, each of the one or more reservation messages being destined to a different one of the apparatuses for reserving a medium for data communication;

transmitting a confirmation message in response to the reservation message; and

receiving data dedicated to the apparatus, the data being transmitted over the medium.

36. The method of claim 35, wherein the confirmation message is transmitted according to a transmission order specified in the reservation message.

37. The method of claim 35, further comprising:

counting a number of one or more other confirmation messages previously transmitted from one or more other apparatuses of the plurality of apparatuses to determine when to transmit the confirmation message.

38. The method of claim 37, further comprising:

detect the one or more other confirmation messages.

39. The method of claim 35, wherein the confirmation message is transmitted immediately after receiving the reservation message.

40. The method of claim 35, wherein the confirmation message is transmitted according to a scheduled time specified in the reservation message.

41. The method of claim 35, wherein:

the reservation message has a format substantially the same as an IEEE 802.11 request-to-send (RTS) message format, and

the confirmation message has a format substantially the same as an IEEE 802.11 clear-to-send (CTS) message format.

42. The method of claim 35, wherein the confirmation message comprises Network Allocation Vector (NAV) information specified in the received reservation message.

43. An apparatus for wireless communications, comprising:

means for receiving, at the apparatus of a plurality of apparatuses, a reservation message from one or more reservation messages, each of the one or more reservation messages being destined to a different one of the apparatuses for reserving a medium for data communication; and

means for transmitting a confirmation message in response to the reservation message, wherein

the means for receiving is further configured to receive data dedicated to the apparatus, the data being transmitted over the medium.

44. The apparatus of claim 43, wherein the confirmation message is transmitted according to a transmission order specified in the reservation message.

45. The apparatus of claim 43, further comprising:

means for counting a number of one or more other confirmation messages previously transmitted from one or more other apparatuses of the plurality of apparatuses to determine when to transmit the confirmation message.

46. The apparatus of claim 45, further comprising:

means for detecting the one or more other confirmation messages.

47. The apparatus of claim 43, wherein the confirmation message is transmitted immediately after receiving the reservation message.

48. The apparatus of claim 43, wherein the confirmation message is transmitted according to a scheduled time specified in the reservation message.

49. The apparatus of claim 43, wherein:

the reservation message has a format substantially the same as an IEEE 802.11 request-to-send (RTS) message format, and

the confirmation message has a format substantially the same as an IEEE 802.11 clear-to-send (CTS) message format.

50. The apparatus of claim 43, wherein the confirmation message comprises Network Allocation Vector (NAV) information specified in the received reservation message.

51. A computer-program product for wireless communications, comprising a computer-readable medium comprising instructions executable to:

receive, at an apparatus of a plurality of apparatuses, a reservation message from one or more reservation messages, each of the one or more reservation messages being destined to a different one of the apparatuses for reserving a medium for data communication;

transmit a confirmation message in response to the reservation message; and

receive data dedicated to the apparatus, the data being transmitted over the medium.

52. An access terminal, comprising:

at least one antenna;

a receiver configured to receive, at the access terminal of a plurality of access terminals via the at least one antenna, a reservation message from one or more reservation messages, each of the one or more reservation messages being destined to a different one of the access terminals for reserving a medium for data communication; and

a transmitter configured to transmit, via the at least one antenna, a confirmation message in response to the reservation message, wherein

the receiver is also configured to receive data dedicated to the access terminal via the at least one antenna, the data being transmitted over the medium.