Methods and apparatus for protection of multi-user (MU) transmissions

1. An Institute of Electrical and Electronics Engineers (IEEE) 802.11 station (STA) comprising:

a receiver and a processor, wherein the receiver and the processor are configured to detect a trigger frame for an uplink (UL) multi-user (MU) transmission, wherein the trigger frame includes an indication that the trigger frame is a request for a bandwidth report and an identifier of at least one STA requested to respond to the trigger frame; and

a transmitter, wherein the processor and the transmitter are configured to, on a condition that an identifier associated with the IEEE 802.11 STA corresponds to the identifier of at least one STA requested to respond to the trigger frame, transmit the bandwidth report in response to the trigger frame, wherein the bandwidth report includes channel availability information for a plurality of channels, the plurality of channels being a combination of 20 MHz sub-channels that make up a wider channel supported by an access point (AP), and

wherein the receiver and the processor are further configured to detect data in a resource unit (RU) of a downlink (DL) MU physical layer (PHY) protocol data unit (PPDU) on at least one of the 20 MHz sub-channels.

2. The STA of claim 1 , wherein the bandwidth report includes at least one of a free channel index, a busy channel index, information regarding interference level, or interference duration information.

3. The STA of claim 1 , wherein the processor and the receiver are further configured to receive the trigger frame from a neighboring STA on a condition that the STA is unable to receive the trigger frame.

4. The STA of claim 1 ,

wherein the processor and the receiver are further configured to receive another trigger frame, and

wherein the processor and the transmitter are further configured to transmit a user specific sequence (USS) in response to the other trigger frame.

5. The STA of claim 1 , wherein the trigger frame further includes an assignment of at least one of resource units, sub-channels and spatial streams for each of the at least one STA requested to respond to the trigger frame.

6. An access point (AP) comprising:

a transmitter and a processor, wherein the transmitter and the processor are configured to send a trigger frame for an uplink (UL) multi-user (MU) transmission to a plurality of Institute of Electrical and Electronics Engineers (IEEE) 802.11 stations (STAs), wherein the trigger frame includes an indication that the trigger frame is a request for a bandwidth report and an identifier of at least one STA requested to respond to the trigger frame; and

a receiver, wherein the receiver and the processor are configured to, on a condition that an identifier associated with the IEEE 802.11 STA corresponds to the identifier of at least one STA requested to respond to the trigger frame, receive the bandwidth report in response to the trigger frame, wherein the bandwidth report includes channel availability information for a plurality of channels, the plurality of channels being a combination of 20 MHz sub-channels that make up a wider channel supported by the AP, and

wherein the transmitter and the processor are further configured to transmit data to at least one of the plurality of IEEE 802.11 STAs in a downlink (DL) physical layer (PHY) protocol data unit (PPDU) on at least one of the 20 MHz sub-channels.

7. The AP of claim 6 , wherein the processor and the transmitter are further configured to duplicate the trigger frame on the plurality of channels.

8. The AP of claim 6 , wherein the bandwidth report includes at least one of a free channel index, a busy channel index, information regarding interference level, or interference duration information.

9. The AP of claim 6 ,

wherein the processor and the transmitter are further configured to transmit another trigger frame, and

wherein the processor and the receiver are further configured to receive a user specific sequence (USS) in response to the other trigger frame.

10. The AP of claim 6 , wherein the trigger frame further includes an assignment of at least one of resource units, sub-channels and spatial streams for each of the at least one STA requested to respond to the trigger frame.

11. A method, implemented in an Institute of Electrical and Electronics Engineers (IEEE) 802.11 station (STA), the method comprising:

detecting a trigger frame for an uplink (UL) multi-user (MU) transmission, wherein the trigger frame includes an indication that the trigger frame is a request for a bandwidth report and an identifier of at least one STA requested to respond to the trigger frame;

on a condition that an identifier associated with the IEEE 802.11 STA corresponds to the identifier of at least one STA requested to respond to the trigger frame, transmitting the bandwidth report in response to the trigger frame, wherein the bandwidth report includes channel availability information for a plurality of channels, the plurality of channels being a combination of 20 MHz sub-channels that make up a wider channel supported by an access point (AP); and

detecting data in a resource unit (RU) of a downlink (DL) MU physical layer (PHY) protocol data unit (PPDU) on at least one of the 20 MHz sub-channels.

12. The method of claim 11 , wherein the bandwidth report includes at least one of a free channel index, a busy channel index, information regarding interference level, or interference duration information.

13. The method of claim 11 , further comprising receiving the trigger frame from a neighboring STA on a condition that the STA is unable to receive the trigger frame.

14. The method of claim 11 , further comprising:

receiving another trigger frame; and

transmitting a user specific sequence (USS) in response to the other trigger frame.

15. The method of claim 11 , wherein the trigger frame further includes an assignment of at least one of resource units, sub-channels and spatial streams for each of the at least one STA requested to respond to the trigger frame.