System and Method for Coordinated Beamforming for Overlapping Basic Service Set in WLAN

• US 20160029227A1
• Filed: 07/24/2014
• Published: 01/28/2016
• Est. Priority Date: 07/24/2014
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Aboul-Magd, Osama, Au, Kwok Shum (Edward), Suh, Junghoon
• Granted Patent: US 9,503,911 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 5/0057 Physical resource allocation for CQI
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 92/20 between access points

Abstract

Embodiments are provided for enabling a coordinated beamforming (CB) mechanism in WLAN scenarios. In an embodiment, an AP sends a Feedback Request (FBR) frame to each one of the STAs in the OBSSs. The OBSSs comprise the STAs and a plurality of APs including the AP. The AP then receives a feedback frame from each STA of the STAs that participate in the CB transmission. The feedback frame includes channel state information (CSI) of the STA. The CSI enables the sending AP of performing CB on downlink. In an embodiment, the AP receives an initiate CB frame from a second AP initiating a CB transmission, and then sends an ACK frame to the second AP before sending the FBR frame to each one of the STAs. The AP starts the CB transmission with each one of the other APs that participate in the CB transmission.

Claims

1. A method by an access point (AP) enabling coordinated beamforming (CB) for overlapping basic service sets (OBSSs) in wireless local area network (WLAN), the method comprising:

sending by the AP a Feedback Request (FBR) frame to each one of a plurality of stations (STAs), wherein the OBSSs comprise the STAs and a plurality of APs including the AP; and

receiving a feedback frame from each STA of the STAs that participate in CB transmission for the OBS Ss, wherein the feedback frame includes channel state information (CSI) of the STA, the CSI enabling the sending AP of performing CB on downlink.

2. The method of claim 1, further comprising:

sending an initiate CB frame to each one of the other APs in the OBSSs;

receiving an acknowledgement (ACK) frame from each one of the other APs intending to participate in the CB transmission; and

starting the CB transmission with each one of the other APs that participate in the CB transmission.

3. The method of claim 2, further comprising sending an end of service period (EOSP) frame terminating the CB transmission.

4. The method of claim 3, wherein the EOSP frame is sent to each one of the other APs participating in the CB transmission.

5. The method of claim 2, further comprising discarding in the CB transmission each one of the other APs of which no ACK frame was received.

6. The method of claim 2, further comprising:

upon starting the CB transmission , gaining access to a wireless medium for sending frames in the OBSSs;

sending, with the other APs participating in the CB transmission, data on downlink to the STAs participating in the CB transmission, wherein the data is sent using CB with the other APs participating in the CB transmission;

sending a Block ACK Request (BAR) frame to each STA associated with the AP; and

receiving a Block ACK (BA) frame from each STA associated with the AP.

7. The method of claim 6, wherein the BAR frame is sent to each STA associated with the AP consecutively in sequence.

8. The method of claim 6, wherein the BAR frame is sent to each STA associated with the AP concurrently using CB on downlink, and wherein the BA frame is received from each STA associated with the AP concurrently via CB on uplink.

9. The method of claim 1, further comprising discarding in the CB transmission each one of the other STAs from which no feedback frame was received.

10. The method of claim 1, wherein the FBR frame to each one of the STAs indicates Media Access Control (MAC) addresses of the sending AP and a target STA.

11. The method of claim 1, wherein the FBR frame is sent to each one of the STAs consecutively in sequence.

12. An access point (AP) enabling coordinated beamforming (CB) for overlapping basic service sets (OBSSs) in wireless local area network (WLAN), the AP comprising:

a processor; and

a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to;

send a Feedback Request (FBR) frame to each one of a plurality of statins (STAs), wherein the OBSSs comprise the STAs and a plurality of APs including the AP; and

receive a feedback frame from each STA of the STAs that participate in CB transmission for the OBS Ss, wherein the feedback frame includes channel state information (CSI) of the STA, the CSI enabling the sending AP of performing CB on downlink.

13. The AP of claim 12, wherein the programming includes further instructions to:

send an initiate CB frame to each one of the other APs in the OBSSs;

receive an acknowledgement (ACK) frame from each one of the other APs that participate in the CB transmission;

start the CB transmission with each one of the other APs that participate in the CB transmission; and

send, to the other APs participating in the CB transmission, an end of service period (EOSP) frame terminating the CB transmission.

14. The AP of claim 13, wherein the programming includes further instructions to:

upon starting the CB transmission, gain access to a wireless medium for sending frames in the OBSSs;

send, with the other APs participating in the CB transmission, data on downlink to the STAs participating in the CB transmission, wherein the data is sent using CB with the other APs participating in the CB transmission;

send a Block ACK Request (BAR) frame to each STA associated with the AP; and

receive a Block ACK (BA) frame from each STA associated with the AP.

15. The AP of claim 12, wherein the FBR frame to each one of the STAs indicates Media Access Control (MAC) addresses of the sending AP and a target STA.

16. A method by an access point (AP) enabling coordinated beamforming (CB) for overlapping basic service sets (OBSSs) in wireless local area network (WLAN), the method comprising:

receiving by the AP an initiate CB frame from a second AP initiating CB transmission for OBSSs, wherein the OBSSs comprise a plurality of APs and a plurality of stations (STAs) associated with the APs;

sending an acknowledgement (ACK) frame to the second AP, wherein the AP participates in the CB transmission with the second AP;

sending a Feedback Request (FBR) frame to each one of the STAs;

receiving a feedback frame from each STA of the STAs that participate in the CB transmission, wherein the feedback frame includes channel state information (CSI) of the STA, the CSI enabling the receiving AP of performing CB on downlink; and

starting the CB transmission with each one of the other APs participating in the CB transmission.

17. The method of claim 16, further comprising receiving, from the second AP, an end of service period (EOSP) frame terminating the CB transmission.

18. The method of claim 16, further comprising:

sending, with the other APs participating in the CB transmission, data on downlink to the STAs participating in the CB transmission, wherein the data is sent using CB with the other APs participating in the CB transmission;

sending a Block ACK Request (BAR) frame to each STA associated with the AP; and

receiving a Block ACK (BA) frame from each STA associated with the AP.

19. The method of claim 16, wherein the FBR frame to each one of the STAs indicates Media Access Control (MAC) addresses of the AP and a target STA.

20. An access point (AP) enabling coordinated beamforming (CB) for overlapping basic service sets (OBSSs) in wireless local area network (WLAN), the AP comprising:

a processor; and

a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to;

receive an initiate CB frame from a second AP initiating in CB transmission for OBSSs, wherein the OBSSs comprise a plurality of APs and a plurality of stations (STAs) associated with the APs;

send an acknowledgement (ACK) frame to the second AP, wherein the AP participates in the CB transmission with the second AP;

send a Feedback Request (FBR) frame to each one of the STAs;

receive a feedback frame from each STA of the STAs that participate in the CB transmission, wherein the feedback frame includes channel state information (CSI) of the STA, the CSI enabling the receiving AP of performing CB on downlink; and

start the CB transmission with each one of the other APs participating in the CB transmission.

21. The AP of claim 20, wherein the programming includes further instructions to:

send, with the other APs participating in the CB transmission, data on downlink to the STAs participating in the CB transmission, wherein the data is sent using CB with the other APs participating in the CB transmission;

send a Block ACK Request (BAR) frame to each STA associated with the AP;

receive a Block ACK (BA) frame from each STA associated with the AP; and

receiving, from the second AP, an end of service period (EOSP) frame terminating the CB transmission.

22. A method by a station (STA) in overlapping basic service sets (OBSSs) in wireless local area network (WLAN), the method comprising:

receiving from an access point (AP) a Feedback Request (FBR) frame, wherein the OBSSs comprise a plurality of APs including the AP and further comprise a plurality of stations (STAs) including the STA; and

sending a feedback frame to the AP, wherein the STA participates in a coordinated beamforming (CB) transmission with the AP, and wherein the feedback frame includes channel state information (CSI) of the STA, the CSI enabling the sending AP of performing CB on downlink.

23. The method of claim 22, further comprising:

receiving data from the AP, wherein the data is sent by the AP using CB with the other APs participating in the CB transmission;

receiving a Block Acknowledgment (ACK) Request (BAR) frame from the AP; and

sending a Block ACK (BA) frame to the AP.

24. The method of claim 23, wherein the BA frame is sent to the AP concurrently with other STAs associated with the AP via CB on uplink.

25. A station (STA) in overlapping basic service sets (OBSSs) in wireless local area network (WLAN), the STA comprising:

a processor; and

a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to;

receive from an access point (AP) a Feedback Request (FBR) frame, wherein the OBSSs comprise a plurality of APs including the AP and further comprise a plurality of stations (STAs) including the STA; and

send a feedback frame to the AP, wherein the STA participates in a coordinated beamforming (CB) transmission with the AP, and wherein the feedback frame includes channel state information (CSI) of the STA, the CSI enabling the sending AP of performing CB on downlink.

26. The STA of claim 25, wherein the programming includes further instructions to:

receive data from the AP, wherein the data is sent by the AP using CB with the other APs participating in the CB transmission;

receive a Block Acknowledgement (ACK) Request (BAR) frame from the AP; and

send a Block ACK (BA) frame to the AP.