Determination and transmission of BSS load metrics for MU WLAN systems

Patent metadata

Field	Value
Publication number	US-10972963-B2
Application number	US-201715648357-A
Country	US
Kind code	B2
Filing date	Jul 12, 2017
Priority date	Jul 12, 2016
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

Systems and methods of providing Basis Service Set (BSS) load information pertinent to multi-user (MU) communications in WLAN systems. An access point (AP) can determine the counts of MU-capable user stations (STAs) active STAs in a BSS. Each MU-capable STA is configured for Multi-User Multiple-Input Multiple-Output (MU-MIMO) communications and/or Orthogonal Frequency-Division Multiple Access (OFDMA) communications. The AP can further determine ratios of PPDU time over an observation period of MU uplink (UL) and downlink (DL) communications, respectively. The AP can further determine an underutilization level of each available frequency subband, the underutilization level integrating the actual underutilization in terms of both spatial streams and frequency subbands. The DL and UL underutilization levels can be separately determined and reported. The MU BSS load information can be included in a beacon frame as a BSS load information element and distributed to user STAs periodically.

First claim

What is claimed is:

1. A method of wireless communication, the method comprising:
at an access point (AP), determining load information of a Basic Service Set (BSS), wherein said determining load information comprises one or more of:
determining first information representing one or more of: a count of active stations (STAs) in said BSS in a first prescribed period; and a count of active multi-user (MU)-capable STAs in said BSS in said first prescribed period, wherein said AP has received data packets from each of said active STAs or each of said active MU-capable STAs in said first prescribed period;
determining second information representing an underutilization of resource units (RUs) usable on multiple spatial stream sizes in said BSS when a channel of said BSS is occupied during a PLCP protocol data unit (PPDU) period; and
transmitting a frame comprising said load information,

wherein said load information further comprises fourth information representing Protocol Data Unit PDU time in relation to medium idle time in a second prescribed period, and
wherein the determining said load information comprises:
summing transmission time of MU uplink (UL) PHY Layer Convergence Procedure (PLCP) Protocol Data Units (PPDUs) in said second prescribed period to obtain a first transmission time; and
summing transmission time of MU downlink (DL) PPDUs in said second prescribed period to obtain a second transmission time.

2. The method of claim 1 , wherein said load information further comprises third information representing a number of MU-capable STAs in said BSS, wherein said MU-capable STAs comprise: STAs configured to perform MU Multiple-Input Multiple-Output (MU-MIMO) communications; and STAs configured to perform MU Orthogonal Frequency-Division Multiple Access (MU-OFDMA) communications.

3. The method of claim 1 , wherein said determining said first information at said AP comprises monitoring activities of an STA in said BSS in said first prescribed period, and wherein further monitored activities of said STA comprise said STA transmitting a Media Access Control (MAC) Protocol Data Unit (MPDU) to said AP.

4. The method of claim 1 , wherein said determining said second information comprises calculating an underutilization rate for a plurality of frequency bandwidths available for orthogonal Frequency-Division Multiple Access (OFDMA) communications, wherein said calculating comprises respectively calculating:
an underutilization rate of a respective frequency bandwidth of said plurality of frequency bandwidths for MU DL transmissions; and
an underutilization rate of said respective frequency bandwidth for MU UL transmissions.

5. The method of claim 4 , wherein said underutilization rate of said respective frequency bandwidth of MU DL transmission information is determined based on a maximum number of supported spatial streams of said respective frequency bandwidth, occupied resource unit weights, RU weights of said respective frequency bandwidth, and MU DL PPDU time.

6. The method of claim 1 , wherein said determining load information further comprises determining fifth information representing a number of resource units (RUs) available for a specific spatial stream size.

7. The method of claim 6 , wherein said determining said fifth information comprises determining respective maximum number of RUs available for different spatial stream sizes over a frequency bandwidth.

8. The method of claim 1 , wherein said determining said second information at said AP comprises
summing transmission time of Single-User (SU) downlink (DL) PPDUs in said second prescribed period to obtain a third transmission time.

9. The method of claim 8 , wherein said frame comprises indications of said first transmission time, said second transmission time and said third transmission time in relation to medium idle time in said second prescribed period, respectively.

10. A wireless station comprising:
a transceiver configured to couple to a wireless network;
a processor; and
a memory coupled to said processor and storing instructions that, when executed by said processor, implement a method of:
determining load information of a Basic Service Set (BSS), wherein said load information comprises one or more of:
determining first information representing one or more of: a count of active STAs in said BSS in a first prescribed period; and a count of active MU-capable STAs in said BSS in said first prescribed period, wherein said AP received data packets from each of said active STAs or each of said active MU-capable STAs in said first prescribed period; and
determining second information representing an underutilization of resource units (RUs) usable on multiple spatial stream sizes in said BSS when a channel of said BSS is occupied during a PLCP protocol data unit (PPDU) period; and

generating a frame comprising said load information,
wherein said transceiver is further configured to transmit said frame, and
wherein said load information further comprises fourth information representing Protocol Data Unit PDU time in a second prescribed period, and wherein said fourth information indicates a ratio of accumulated DL MU PPDU time to said second prescribed period and a ratio of accumulated UL MU PPDU time to said second prescribed period.

11. The wireless station of claim 10 , wherein said load information further comprises third information representing a number of MU-capable STAs in said BSS, wherein said MU-capable STAs comprise: STAs configured to perform MU Multiple-Input Multiple-Output (MU-MIMO) communications; and STAs configured to perform MU Orthogonal Frequency-Division Multiple Access (MU-OFDMA) communication.

12. The wireless station of claim 10 , wherein said method further comprises monitoring activities of an STA in said BSS in said first prescribed period, wherein a monitored activity of said STA comprises said STA transmitting a Medium Access Control (MAC) Protocol Data Unit (MPDU) to said AP.

13. The wireless station of claim 10 , wherein said load information further comprises a ratio of accumulated DL Single User (SU) PPDU time to said second prescribed period.

14. The wireless station of claim 10 , wherein said determining said second information comprises calculating underutilization rates for a plurality of frequency bandwidths, wherein said calculating comprises respectively calculating:
an underutilization rate of a respective frequency bandwidth of said plurality of frequency bandwidth for MU DL transmissions; and
an underutilization rate of said respective frequency bandwidth for MU UL transmissions.

15. The wireless station of claim 14 , wherein said underutilization rate of said respective frequency bandwidth of MU UL transmissions is determined based on a maximum number of supported spatial streams of said respective frequency bandwidth, occupied resource unit weights, RU weights of said respective frequency bandwidth, and MU UL PPDU time.

16. The wireless station of claim 10 , wherein said load information further comprises fifth information representing a number of resource units (RUs) available for a specific spatial stream size.

17. A wireless station comprising:
a transceiver configured to receive a frame transmitted from an access point (AP) STA in a Basis Service Set (BSS), wherein said frame comprises load information of said BSS, wherein said load information comprises one or more of:
first information representing one or more of: a count of active STAs in said BSS in a first prescribed period; and a count of active MU-capable STAs in said BSS in said firs

Assignees

• Mediatek Inc

Inventors

• Hsu Chien-Fang
• Wang Chao-Chun
• Yee Chih-Shi
• Bajko Gabor

Classifications

• H04W72/52

  based on load · CPC title

• H04W48/06 Primary

  based on traffic conditions · CPC title

• H04W48/20

  Selecting an access point · CPC title

• H04B7/0452

  Multi-user MIMO systems · CPC title

• H04W48/12

  using downlink control channel · CPC title