Dynamic parameters for multi-user channel access

Abstract

The present disclosure provides systems, methods, and apparatus for wireless communications, including a computer program encoded on a computer storage medium. In some implementations, a wireless communication device: obtains one or more indications that a wireless station (STA) will enter a power saving mode; selects a duration associated with each respective STA in a plurality of STAs for the respective STA to enter the power saving mode; and adjusts one or more parameters associated with the selected duration for a multi-user channel access mechanism for transmitting uplink data. In some other implementations, a wireless communication device: outputs one or more indications that the device will enter a power saving mode; outputs or obtains data at each first moment in a plurality of first moments; enters a power saving mode at each second moment in a plurality of second moments; and obtains a beacon indicating one or more parameters to be used for a multi-user channel access mechanism for transmitting uplink data.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 017,638, filed on April 29, 2020, and entitled “DYNAMIC PARAMETERS FOR MULTI-USER CHANNEL ACCESS,” and U.S. Non-Provisional Application No. 17 / 204,530, filed on March 17, 2021, and entitled “DYNAMIC PARAMETERS FOR MULTI-USERCHANNEL ACCESS,” both of which are assigned in their entirety to the assignee thereof. The disclosures of all prior applications are considered part of this patent application and are each incorporated in their entirety by reference into this patent application. Technical Field

[0003] The present disclosure relates generally to wireless networks, and to multi-user (MU) channel access mechanisms for a shared wireless medium.

[0004] Related technical description

[0005] A wireless local area network (WLAN) may be formed by one or more access points (APs) that provide a shared wireless communication medium for use by several client devices, also referred to as stations (STAs). The basic building block of a WLAN that complies with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards is a basic service set (BSS) managed by an AP. Each BSS is identified by a basic service set identifier (BSSID) advertised by the AP. The AP periodically broadcasts beacon frames to enable any STA within the wireless range of the AP to establish or maintain a communication link with the WLAN.

[0006] Wireless networks may use random channel access mechanisms to control access to a shared wireless medium. In such wireless networks, wireless devices (including APs and STAs) typically use carrier sense multiple access with collision avoidance (CSMA / CA) techniques to contend with each other to gain access to the wireless medium. Generally speaking, the wireless device with the lowest backoff number is randomly selected to win the medium access contention operation and may be granted access to the wireless medium for a period of time, which is generally referred to as a transmit opportunity (TXOP). Other wireless devices are generally not allowed to transmit during the TXOP to avoid interfering with transmissions from the TXOP owner.

[0007] Overview

[0008] The systems, methods, and devices of the disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0009] An innovative aspect of the subject matter described in the present disclosure may be implemented in a method for wireless communication. The method may be performed by a device of a wireless access point (AP). The method includes receiving one or more indications from each of a plurality of wireless stations (STAs) associated with the AP that the corresponding STA will enter a power saving mode. The method further includes selecting, for each of the plurality of STAs, a duration between a first moment at which the corresponding STA transmits or receives data and a second moment at which the corresponding STA enters a power saving mode. The method further includes adjusting one or more parameters associated with the selected duration for a multi-user (MU) channel access mechanism for transmitting uplink (UL) data.

[0010] In some implementations, the duration is an average duration between a plurality of first times at which the corresponding STA transmits or receives data and a plurality of corresponding second times at which the corresponding STA enters a power saving mode. In some other implementations, at least one of the one or more indications includes a power management (PM) bit carried in a media access control (MAC) frame, wherein the PM bit is set to 1. In some instances, the MAC frame is a quality of service (QoS) NULL frame. In some other implementations, at least one of the one or more indications includes a PM bit carried in a media access control (MAC) frame, wherein the PM bit is set to 0, and the method further includes transmitting a buffer status report (BSR) trigger frame that triggers the corresponding STA to transmit buffer status information when exiting the power saving mode.

[0011] In some instances, the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between transmissions of triggered frames to the respective STAs. In some implementations, dynamically adjusting the one or more parameters includes decreasing at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval based on a selected duration of at least some of the plurality of STAs being greater than a value. In some instances, the method further includes setting the MU EDCA timer value to a duration, and receiving an unsolicited BSR from at least one of the plurality of STAs based on the duration of the MU EDCA timer value exceeding a time period.

[0012] In some other implementations, the method further includes adjusting a time interval between transmissions of triggered frames to the respective STA based at least in part on the determined duration of the respective STA. In some implementations, the method further includes selecting an average frequency at which the respective STA queues UL data for transmission to the AP, wherein dynamically adjusting the one or more parameters is further based on the determined average frequency.

[0013] In some implementations, the method further includes estimating a power saving schedule for each respective STA of the plurality of STAs based at least in part on the one or more indications, wherein dynamically adjusting the one or more parameters is further based on the estimated power saving schedules for the plurality of STAs. In some instances, the estimated power saving schedule for the respective STA indicates whether the respective STA transmits its UL data queue size to the AP when exiting a power saving mode, and the method further includes: selecting, for the respective STA, an average duration between a first time when the respective STA exits the power saving mode and a second time when the respective STA transmits its UL data queue size to the AP, including the respective STA in a scheduling candidate set for a UL basic trigger when the determined average duration is less than a value, and transmitting a basic trigger frame that triggers the respective STA to transmit UL QoS information when exiting the power saving mode.

[0014] In some instances, the estimated power saving schedule of the corresponding STA indicates whether the corresponding STA transmits its UL data queue size to the AP when exiting the power saving mode, and the method further includes: selecting, for the corresponding STA, an average duration between a first time when the corresponding STA exits the power saving mode and a second time when the corresponding STA transmits its UL data queue size to the AP, and transmitting a BSR trigger frame that triggers the corresponding STA to transmit buffer status information upon exiting the power saving mode when the determined average duration is greater than a value. In some other instances, the estimated power saving schedule of the corresponding STA indicates a likelihood that the corresponding STA has queued UL data.

[0015] In some implementations, the method further includes transmitting a basic trigger frame that triggers one or more of the multiple STAs to transmit UL QoS information when exiting the power saving mode when the determined duration is less than a value. In some other implementations, the method further includes transmitting a buffer status report (BSR) trigger frame that triggers one or more of the multiple STAs to transmit buffer status information when exiting the power saving mode when the determined duration is greater than a value.

[0016] Another innovative aspect of the subject matter described in the present disclosure may be implemented in a wireless communication device. The wireless communication device may include a processing system coupled to an interface. The interface is configured to obtain one or more indications that a wireless station (STA) will enter a power saving mode. The processing system is configured to select a duration between a first moment at which the corresponding STA transmits or receives data and a second moment at which the corresponding STA enters a power saving mode for each corresponding STA in the plurality of STAs. The processing system is further configured to adjust one or more parameters associated with the selected duration for transmitting uplink (UL) data of a multi-user (MU) channel access mechanism.

[0017] In some implementations, at least one of the one or more indications includes a power management (PM) bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 1. In some instances, the MAC frame is a quality of service (QoS) NULL frame. In some other implementations, at least one of the one or more indications includes a PM bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 0, and the interface is further configured to output a buffer status report (BSR) trigger frame that triggers the corresponding STA to transmit buffer status information upon exiting a power saving mode.

[0018] In some other implementations, the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between transmissions of triggered frames to the respective STAs. In some instances, dynamically adjusting the one or more parameters includes reducing at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval based on the selected duration of at least some of the plurality of STAs being greater than a value. In some implementations, the processing system is further configured to estimate a power saving schedule for each respective STA of the plurality of STAs based at least in part on the one or more indications, wherein dynamically adjusting the one or more parameters is further based on the estimated power saving schedules for the plurality of STAs.

[0019] Another innovative aspect of the subject matter described in the present disclosure may be implemented in a method for wireless communication. The method may be performed by a device of a wireless station (STA). The method includes transmitting one or more indications to a wireless access point (AP) that the STA will enter a power saving mode. The method further includes communicating data at each first moment in a plurality of first moments. The method further includes entering a power saving mode at each second moment in a plurality of second moments. The method further includes receiving a beacon from the AP indicating one or more parameters for transmitting uplink (UL) data for a multi-user (MU) channel access mechanism.

[0020] In some implementations, at least one of the one or more parameters is configured based on a duration between a corresponding pair of the first time instant and the second time instant, and the duration indicates an average duration between the corresponding pair of the first time instant and the second time instant. In some instances, at least one of the one or more indications includes a power management (PM) bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 1. In some implementations, the MAC frame is a quality of service (QoS) NULL frame.

[0021] In some other implementations, at least one of the one or more indications includes a PM bit carried in a media access control (MAC) frame, wherein the PM bit is set to 0, and the method further includes receiving a buffer status report (BSR) trigger frame that triggers the STA to transmit buffer status information to the AP upon exiting a power save mode. In some instances, the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between transmissions of trigger frames to the STA. In some implementations, at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is set based on at least one of a duration between a corresponding pair of a first time instant and a second time instant being greater than a value, a likelihood that the STA has queued UL data, or an average frequency with which the STA queues UL data for transmission to the AP.

[0022] In some implementations, at least one of the one or more parameters indicates a duration of a MU EDCA timer value, and the method further includes transmitting an unsolicited BSR to the AP based on the duration of the MU EDCA timer value exceeding a time period, wherein the unsolicited BSR indicates buffer status information for at least one access category (AC) not affected by the MU EDCA timer value. In some instances, at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is set based on an average duration between a first time the STA exits a power saving mode and a second time the STA transmits its UL data queue size to the AP, and the method further includes receiving a basic trigger frame that triggers the STA to transmit UL QoS information to the AP upon exiting the power saving mode when the average duration is less than a value, and receiving a buffer status report (BSR) trigger frame that triggers the STA to transmit buffer status information to the AP upon exiting the power saving mode when the average duration is greater than the value.

[0023] In some other implementations, the method further includes increasing the power save timer in response to receiving a trigger frame from the AP when the STA is operating in the first power save mode and not receiving a trigger frame from the AP when the STA is operating in the second power save mode. In some instances, the method further includes increasing the power save timer in response to receiving a trigger frame from the AP when the STA is operating in the first power save mode and not receiving a trigger frame from the AP when the STA is operating in the second power save mode.

[0024] Another innovative aspect of the subject matter described in the present disclosure may be implemented in a wireless communication device. The wireless communication device may include a processing system coupled to an interface. The interface is configured to output one or more indications that the wireless communication device will enter a power saving mode. The interface is further configured to output or obtain data at each first moment in a plurality of first moments. The processing system is further configured to enter a power saving mode at each second moment in a plurality of second moments. The interface is further configured to obtain a beacon indicating one or more parameters to be used for a multi-user (MU) channel access mechanism to transmit uplink (UL) data.

[0025] In some implementations, at least one of the one or more indications includes a power management (PM) bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 1. In some instances, the MAC frame is a quality of service (QoS) NULL frame. In some other implementations, at least one of the one or more indications includes a PM bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 0, and wherein the interface is further configured to obtain a buffer status report (BSR) trigger frame that triggers the wireless communication device to transmit buffer status information upon exiting a power save mode.

[0026] Details of one or more implementations of the subject matter described in the present disclosure are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. It should be noted that the relative sizes of the following drawings may not be drawn to scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of an example wireless communication network is shown.

[0029] Figure 2 A block diagram of an example wireless communication device is shown.

[0030] Figure 3A A block diagram of an example access point (AP) is shown.

[0031] Figure 3B A block diagram of an example station (STA) is shown.

[0032] Figure 4 A timing diagram illustrating the transmission of a communication is shown.

[0033] Figure 5 A timing diagram illustrating the transmission of a communication is shown.

[0034] Figure 6 A timing diagram illustrating the transmission of a communication is shown.

[0035] Figure 7 A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0036] Fig. 8A A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0037] Figure 8B A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0038] Figure 8CA flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0039] Fig.8D A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0040] Fig. 8E A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0041] Fig.8F A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0042] Figure 8G A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0043] Figure 8H A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0044] Figure 8I A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0045] Figure 8J A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0046] Fig. 9 A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0047] Fig. 10A A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0048] Fig. 10B A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0049] Fig. 10C A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0050] Fig. 10D A flow diagram illustrating example operations for wireless communications supporting a multi-user channel access mechanism is shown.

[0051] Like reference numbers and designations in the various drawings indicate like elements.

[0052] Detailed Description

[0053] The following description is directed to some specific implementations in order to describe the innovative aspects of the present disclosure. However, one of ordinary skill in the art will readily recognize that the teachings herein can be applied in many different ways. The described implementations can be implemented in a manner that is capable of being implemented in accordance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, the IEEE 802.15 standard, the Bluetooth SIG standard, or the like as defined by the Bluetooth Special Interest Group (SIG). The described implementations may be implemented in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals in accordance with one or more of the Long Term Evolution (LTE), 3G, 4G, or 5G (New Radio (NR)) standards, or the like released by the Third Generation Partnership Project (3GPP). The described implementations may be implemented in any device, system, or network capable of transmitting and receiving RF signals in accordance with one or more of the following technologies or techniques: code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), single user (SU) multiple input multiple output (MIMO), and multi-user (MU) MIMO. The described implementations may also be implemented using other wireless communication protocols or RF signals suitable for use in one or more of a wireless personal area network (WPAN), a wireless local area network (WLAN), a wireless wide area network (WWAN), or an Internet of Things (IOT) network.

[0054] When contending for medium access, some wireless communication devices may employ an EDCA mechanism based on a multi-user (MU) enhanced distributed channel access (EDCA) value, which is typically advertised by the AP in one or more beacons. In some instances, a power saving STA may wake up from a power saving mode to listen for beacons, and re-enter the power saving mode for one or more beacon intervals after receiving the beacon. If the AP sets a relatively high MU EDCA value so that the contention window for medium access contention operation is relatively long, the STA may enter the power saving mode before the contention window expires (and thus before the STA's backoff counter reaches a zero value). As a result, the STA may not win the medium access contention operation, and may also not wake up after the contention window expires to receive a trigger frame from the AP, which may increase network latency. Specifically, the AP may refrain from transmitting a trigger frame to the STA until the AP receives an indication that the STA has buffered UL data, and the STA may refrain from transmitting its buffered UL data to the AP until a trigger frame from the AP is received, resulting in a deadlock between the AP and the STA, which may also increase network latency.

[0055] Various implementations generally relate to medium access contention operations on a shared wireless medium. Some implementations more specifically relate to dynamically adjusting parameters of a multi-user (MU) channel access mechanism for transmitting uplink (UL) data based on power saving behaviors of multiple STAs associated with an AP. In some implementations, the AP may receive one or more indications from each of the multiple STAs that the corresponding STA will enter a power saving mode. The AP may determine, for each STA, a duration between a time when the corresponding STA transmits or receives data and a time when the corresponding STA enters a power saving mode. Based on the determined duration, the AP may dynamically adjust one or more parameters of the MU channel access mechanism (such as a MU EDCA value) to increase the likelihood that the STA is in an awake state long enough to receive a trigger frame, contend for medium access, and transmit UL data to the AP.

[0056] In some implementations, the AP may observe other behaviors of the STA and dynamically adjust one or more parameters of the MU channel access mechanism accordingly. For example, the AP may determine the average frequency at which the corresponding STA queues UL data for transmission to the AP, and adjust at least one parameter based on the determined average frequency. As another example, the AP may determine the average frequency at which the corresponding STA transmits its UL data queue size to the AP when exiting a power saving mode, and adjust at least one parameter based on the determined average frequency.

[0057] In some implementations, the AP may determine an average duration between the time when the corresponding STA exits the power saving mode and the time when the corresponding STA transmits the UL data queue size information to the AP. In such implementations, if the average duration is less than a value, the AP may transmit a basic trigger frame that triggers the corresponding STA to transmit UL quality of service (QoS) information to the AP upon exiting the power saving mode, for example, so that the AP has an indication of the power saving schedule of the corresponding STA. If the average duration is greater than a value, the AP may transmit a buffer status report (BSR) trigger frame that triggers the corresponding STA to transmit buffer status information to the AP upon exiting the power saving mode, for example, so that the AP has an indication of the amount of UL data queued in the corresponding STA.

[0058] Specific implementations of the subject matter described in this disclosure may be implemented to achieve one or more of the following potential advantages. By dynamically adjusting the parameters of the MU channel access mechanism based on the power saving behavior of each STA associated with the AP, the AP may transmit a trigger frame at each time the STA wakes up during this period, thereby increasing the likelihood that the STA can transmit UL data to the AP, which in turn may reduce network latency. Similarly, by triggering the power saving STA to transmit UL QoS information or buffer status information to the AP upon exiting power saving mode, the AP and the power saving STA may avoid transmission deadlock, which further reduces network latency. Thus, various implementations of the subject matter described in this disclosure may be used to reduce network latency for power saving STAs.

[0059] Figure 1 A block diagram of an example wireless communication network 100 is shown. According to some aspects, the wireless communication network 100 may be an example of a wireless local area network (WLAN) such as a Wi-Fi network (and will be referred to as WLAN 100 hereinafter). For example, the WLAN 100 may be a network that implements at least one of the IEEE 802.11 family of wireless communication protocol standards, such as the standards defined by the IEEE 802.11-2016 specification or its revisions, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be. The WLAN 100 may include numerous wireless communication devices, such as an access point (AP) 102 and a plurality of stations (STAs) 104. Although only one AP 102 is shown, the WLAN network 100 may also include a plurality of APs 102.

[0060] Each STA 104 may also be referred to as a mobile station (MS), a mobile device, a mobile handset, a wireless handset, an access terminal (AT), a user equipment (UE), a subscriber station (SS), or a subscriber unit, among other possibilities. STA 104 may represent a variety of devices, such as mobile phones, personal digital assistants (PDAs), other handheld devices, netbooks, netbook computers, tablet computers, laptops, display devices (e.g., TVs, computer monitors, navigation systems, etc.), music or other audio or stereo equipment, remote control devices (“remote controls”), printers, kitchen or other home appliances, key fobs (e.g., for passive keyless entry and start (PKES) systems), and the like.

[0061] A single AP 102 and the associated set of STAs 104 may be referred to as a basic service set (BSS), which is managed by the corresponding AP 102 . Figure 1Additionally shown is an example coverage area 108 of the AP 102, which may represent a basic service area (BSA) of the WLAN 100. The BSS may be identified to users by a service set identifier (SSID) and may also be identified to other devices by a basic service set identifier (BSSID), which may be a media access control (MAC) address of the AP 102. The AP 102 periodically broadcasts a beacon frame (“beacon”) including the BSSID to enable any STA 104 within the wireless range of the AP 102 to “associate” or reassociate with the AP 102 to establish or maintain a corresponding communication link 106 (hereinafter also referred to as a “Wi-Fi link”) with the AP 102. For example, the beacon may include an identification of a primary channel used by the corresponding AP 102 and a timing synchronization function for establishing or maintaining timing synchronization with the AP 102. The AP 102 may provide access to external networks to various STAs 104 in the WLAN via corresponding communication links 106 .

[0062] To establish a communication link 106 with the AP 102, each STA 104 is configured to perform passive or active scanning operations ("scanning") on frequency channels in one or more frequency bands (eg, 2.4 GHz, 5 GHz, 6 GHz, or 60 GHz bands). To perform a passive scan, the STA 104 listens for beacons transmitted by the corresponding AP 102 at periodic time intervals, referred to as target beacon transmission times (TBTTs), measured in time units (TUs), where one TU may be equal to 1024 microseconds (μs). To perform an active scan, the STA 104 generates probe requests and transmits them sequentially on each channel to be scanned, and listens for probe responses from the AP 102. Each STA 104 may be configured to identify or select an AP 102 to associate with based on the scan information obtained through passive or active scanning, and to perform authentication and association operations to establish a communication link 106 with the selected AP 102. The AP 102 assigns an association identifier (AID) to the STA 104 at the end of the association operation, and the AP 102 uses the AID to track the STA 104.

[0063] As wireless networks become more and more common, STA 104 may have the opportunity to select one of many BSSs within the range of the STA or to select among multiple APs 102 that together form an extended service set (ESS) (including multiple connected BSSs). The extended network station associated with WLAN 100 may be connected to a wired or wireless distribution system that allows multiple APs 102 to be connected in such an ESS. In this way, STA 104 may be covered by more than one AP 102 and may be associated with different APs 102 at different times for different transmissions. Additionally, after associating with AP 102, STA 104 may also be configured to periodically scan its surroundings to find a more suitable AP 102 to associate with. For example, a STA 104 that is moving relative to its associated AP 102 may perform a "roaming" scan to find another AP 102 with more suitable network characteristics (such as a larger received signal strength indicator (RSSI) or a reduced traffic load).

[0064] In some cases, STA 104 may form a network without AP 102 or other equipment other than STA 104 itself. An example of such a network is an ad hoc network (or wireless ad hoc network). An ad hoc network may alternatively be referred to as a mesh network or a peer-to-peer (P2P) network. In some cases, an ad hoc network may be implemented within a larger wireless network (such as WLAN 100). In such an implementation, although STA 104 may be able to communicate with each other through AP 102 using a communication link 106, STA 104 may also communicate directly with each other via a direct wireless link 110. In addition, two STAs 104 may communicate via a direct communication link 110, regardless of whether the two STAs 104 are associated with the same AP 102 and served by the same AP 102. In such an ad hoc system, one or more STAs 104 may assume the role played by AP 102 in a BSS. Such STAs 104 may be referred to as group owners (GOs) and may coordinate transmissions within the ad hoc network. Examples of direct wireless link 110 include a Wi-Fi Direct connection, a connection established by using a Wi-Fi Tunneled Direct Link Setup (TDLS) link, and other P2P group connections.

[0065] The AP 102 and the STA 104 may function and communicate (via corresponding communication links 106) in accordance with the IEEE 802.11 family of wireless communication protocol standards, such as those defined by the IEEE 802.11-2016 specification or its revisions, including, but not limited to, 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be. These standards define WLAN radio and baseband protocols for the PHY and media access control (MAC) layers. The AP 102 and the STA 104 transmit and receive wireless communications (hereinafter also referred to as "Wi-Fi" communications) to and from each other in the form of physical layer convergence protocol (PLCP) protocol data units (PPDUs). The AP 102 and STA 104 in the WLAN 100 may transmit PPDUs on an unlicensed spectrum, which may be a portion of a spectrum that includes frequency bands traditionally used by Wi-Fi technology, such as the 2.4 GHz band, the 5 GHz band, the 60 GHz band, the 3.6 GHz band, and the 900 MHz band. Some implementations of the AP 102 and STA 104 described herein may also communicate in other frequency bands, such as the 6 GHz band, that may support both licensed and unlicensed communications. The AP 102 and STA 104 may also be configured to communicate on other frequency bands, such as shared licensed frequency bands, where multiple operators may have licenses to operate in one or more of the same or overlapping frequency bands.

[0066] Each frequency band may include multiple sub-bands or frequency channels. For example, PPDUs that comply with the IEEE 802.11n, 802.11ac, and 802.11ax standard amendments may be transmitted on 2.4 GHz, 5 GHz, and 6 GHz frequency bands, where each frequency band is divided into multiple 20 MHz channels. In this way, these PPDUs are transmitted on a physical channel with a minimum bandwidth of 20 MHz, but larger channels may be formed through channel bonding. For example, a PPDU may be transmitted on a physical channel with a bandwidth of 40 MHz, 80 MHz, 160 MHz, or 320 MHz by bonding multiple 20 MHz channels together.

[0067] Each PPDU is a composite structure including a PHY preamble and a payload in the form of a PLCP service data unit (PSDU). The information provided in the preamble can be used by the receiving device to decode subsequent data in the PSDU. In an instance where the PPDU is transmitted over a bonded channel, the preamble field can be copied and transmitted in each of a plurality of component channels. The PHY preamble may include both a legacy portion (or "legacy preamble") and a non-legacy portion (or "non-legacy preamble"). Legacy preambles can be used for packet detection, automatic gain control, and channel estimation, as well as other purposes. Legacy preambles can also generally be used to maintain compatibility with legacy devices. The format, decoding, and information provided therein of the non-legacy portion of the preamble are based on the specific IEEE 802.11 protocol to be used to transmit the payload.

[0068] Access to the shared wireless medium is typically managed by a distributed coordination function (DCF). With DCF, there is generally no centralized master device that allocates time and frequency resources for the shared wireless medium. Before a wireless communication device (such as AP 102 or STA 104) is allowed to transmit data, the wireless communication device waits for a specific time and contends for access to the wireless medium. In some implementations, the wireless communication device may be configured to implement DCF by using carrier sense multiple access (CSMA) (CSMA / CA) technology with collision avoidance (CA) and timing intervals. Before transmitting data, the wireless communication device may perform a clear channel assessment (CCA) and determine that an appropriate wireless channel is idle. CCA includes physical (PHY level) carrier sense and virtual (MAC level) carrier sense. Physical carrier sense (or packet detection (PD)) is accomplished via a measurement of the received signal strength of a valid frame, which is compared with a value to determine whether the channel is busy. For example, if the received signal strength of the detected preamble is higher than the value, the medium is considered busy. Physical carrier sense also includes energy detection (ED). Energy detection involves measuring the total energy received by the wireless communication device regardless of whether the received signal represents a valid frame. If the total energy detected is above a value, the medium is considered busy. Virtual carrier sensing is accomplished via the use of a network allocation vector (NAV), which is an indicator of the time when the medium may next become idle. The NAV is reset each time a valid frame that is not addressed to the wireless communication device is received. The NAV effectively serves as a duration of time that elapses before the wireless communication device can contend for access, even in the absence of detected symbols or even if the detected energy is below this value.

[0069] DCF is implemented by using time intervals. These time intervals include slot times (or "slot intervals") and interframe spaces (IFS). Slot times are basic timing units and can be determined based on one or more of transmit-receive turnaround time, channel sense time, propagation delay, and MAC processing time. Measurements of channel sense are performed for each slot. All transmissions can start at slot boundaries. Example variants of IFS include short IFS (SIFS), distributed IFS (DIFS), extended IFS (EIFS), or arbitration IFS (AIFS). For example, DIFS can be defined as the sum of SIFS and twice the slot time. The values ​​of the slot time and IFS may be provided by a suitable standard specification, such as one of the IEEE 802.11 family of wireless communication protocol standards (such as the standards defined by the IEEE 802.11-2016 specification or its amendments, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be).

[0070] When the NAV reaches 0, the wireless communication device performs physical carrier sensing. If the channel remains idle within an appropriate IFS (e.g., DIFS), the wireless communication device initiates a backoff timer, which indicates the duration of time that the device senses that the medium is idle before allowing the device to transmit. The backoff timer decrements one slot each time the medium is sensed to be idle during the corresponding time slot interval. If the channel remains idle until the backoff timer expires, the wireless communication device becomes the owner (or "owner") of the transmission opportunity (TXOP) and can begin transmitting. TXOP is the duration of time that the wireless communication device can transmit frames on the channel after the wireless communication device has won contention for the wireless medium. On the other hand, if one or more carrier sensing mechanisms indicate that the channel is busy, the MAC controller within the wireless communication device will not allow transmission.

[0071] Each time a wireless communication device generates a new PPDU for transmission in a new TXOP, the wireless communication device randomly selects a new backoff timer duration. The available distribution of numbers that can be randomly selected for the backoff timer is called a contention window (CW). When the backoff timer expires, if the wireless communication device transmits the PPDU, but the medium is still busy, there may be a conflict. Additionally, if there is too much energy on the wireless channel, resulting in a poor signal-to-noise ratio (SNR), the communication may be damaged or otherwise not successfully received. In such instances, the wireless communication device may not receive a communication confirming the transmission of the PDU within the timeout interval. The MAC may increase the CW exponentially (e.g., double it) and randomly select a new backoff timer duration from the CW before each attempted retransmission of the PPDU. Before each attempted retransmission, the wireless communication device may wait for the duration of DIFS, and if the medium remains idle, proceed to initiate a new backoff timer. There are different CW and TXOP durations for each of the four access categories (AC): Voice (AC_VO), Video (AC_VI), Background (AC_BK), and Best Effort (AC_BE). This enables specific types of traffic to be prioritized in the network.

[0072] The AP 102 and the STAs 104 may support multi-user (MU) communications; that is, concurrent transmissions from one device to each of multiple devices (e.g., multiple simultaneous downlink (DL) communications from the AP 102 to the corresponding STAs 104), or concurrent transmissions from multiple devices to a single device (e.g., multiple simultaneous uplink (UL) transmissions from the corresponding STAs 104 to the AP 102). To support MU transmissions, the AP 102 and the STAs 104 may utilize multi-user multiple-input multiple-output (MU-MIMO) and multi-user orthogonal frequency division multiple access (MU-OFDMA) techniques.

[0073] In the MU-OFDMA scheme, the available spectrum of a wireless channel may be divided into multiple resource units (RUs), each of which includes several different frequency subcarriers ("tones"). Different RUs may be allocated or assigned to different STAs 104 by AP 102 at a specific time. The size and distribution of RUs may be referred to as RU allocation. In some implementations, RUs may be allocated in 2MHz intervals, and thus, the minimum RU may include 26 tones including 24 data tones and 2 pilot tones. Therefore, in a 20MHz channel, up to 9 RUs (such as 2MHz, 26-tone RUs) may be allocated (because some tones are reserved for other purposes). Similarly, in a 160MHz channel, up to 74 RUs may be allocated. Larger 52-tone, 106-tone, 242-tone, 484-tone, and 996-tone RUs may also be allocated. Adjacent RUs may be separated by a null subcarrier, such as a DC subcarrier, for example, to reduce interference between adjacent RUs, reduce receiver DC offset, and avoid transmit center frequency leakage.

[0074] For UL MU transmissions, the AP 102 may transmit a trigger frame to initiate and synchronize UL MU-OFDMA or UL MU-MIMO transmissions from multiple STAs 104 to the AP 102. Such a trigger frame may thereby enable multiple STAs 104 to send UL traffic concurrently in time to the AP 102. The trigger frame may address one or more STAs 104 by a corresponding association identifier (AID), and may assign one or more RUs to each AID (and thus each STA 104) that may be used to send UL traffic to the AP 102. The AP may also specify one or more random access (RA) RUs that unscheduled STAs 104 may contend for.

[0075] Figure 2 2 shows a block diagram of an example wireless communication device 200. In some implementations, the wireless communication device 200 may be a STA (such as a Figure 1 In some implementations, the wireless communication device 200 may be an example of a device in an AP (such as one of the STAs 104 described above). Figure 1The wireless communication device 200 is an example of a device in the AP 102 described above. The wireless communication device 200 is capable of transmitting (or outputting for transmission) and receiving wireless communications (e.g., in the form of wireless packets). For example, the wireless communication device can be configured to: transmit and receive packets in the form of physical layer convergence protocol (PLCP) protocol data units (PPDUs) and media access control (MAC) protocol data units (MPDUs) that comply with the IEEE 802.11 wireless communication protocol standard (such as the standard defined by the IEEE 802.11-2016 specification or its revisions, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be).

[0076] The wireless communication device 200 may be or may include a chip, system on chip (SoC), chipset, package, or device including one or more modems 202 (e.g., Wi-Fi (IEEE 802.11 compliant) modems). In some implementations, the one or more modems 202 (collectively, "modems 202") additionally include a WWAN modem (e.g., a 3GPP 4G LTE or 5G compatible modem). In some implementations, the wireless communication device 200 also includes one or more radios 204 (collectively, "radios 204"). In some implementations, the wireless communication device 206 further includes one or more processors, processing blocks, or processing elements 206 (collectively, "processors 206") and one or more memory blocks or elements 208 (collectively, "memory 208").

[0077] The modem 202 may include an intelligent hardware block or device (for example, such as an application specific integrated circuit (ASIC)). The modem 202 is generally configured to implement the PHY layer. For example, the modem 202 is configured to modulate packets and output the modulated packets to the radio 204 for transmission on the wireless medium. Similarly, the modem 202 is configured to obtain modulated packets received by the radio 204 and demodulate the packets to provide demodulated packets. In addition to the modulator and demodulator, the modem 202 may further include a digital signal processing (DSP) circuit system, an automatic gain control (AGC), an encoder, a decoder, a multiplexer, and a demultiplexer. For example, when in the transmission mode, the data obtained from the processor 206 is provided to the encoder, which encodes the data to provide coded bits. The coded bits are mapped to points in the modulation constellation (using the selected MCS) to provide modulated symbols. The modulated symbols can be mapped to a number (N SS ) spatial streams or several (N STSThe modulated symbols in the corresponding spatial stream or space-time stream may be multiplexed, transformed via an inverse fast Fourier transform (IFFT) block, and then provided to the DSP circuit system for Tx windowing and filtering. The digital signal may be provided to a digital-to-analog converter (DAC). The resulting analog signal may be provided to an upconverter and ultimately to the radio 204. In an implementation involving beamforming, the modulated symbols in the corresponding spatial stream are precoded via a steering matrix before being provided to the IFFT block.

[0078] When in receive mode, a digital signal received from the radio 204 is provided to a DSP circuit system that is configured to acquire the received signal, for example, by detecting the presence of the signal and estimating the initial timing and frequency offset. The DSP circuit system is further configured to digitally condition the digital signal, for example, using channel (narrowband) filtering, analog impairment conditioning (such as correcting I / Q imbalance), and applying digital gain to ultimately obtain a narrowband signal. The output of the DSP circuit system may be fed to an AGC that is configured to use information extracted from the digital signal (e.g., in one or more received training fields) to determine an appropriate gain. The output of the DSP circuit system is also coupled to a demodulator that is configured to extract modulated symbols from the signal and, for example, calculate a log-likelihood ratio (LLR) for each bit position of each subcarrier in each spatial stream. The demodulator is coupled to a decoder that may be configured to process the LLRs to provide decoded bits. The decoded bits from all spatial streams are fed to a demultiplexer for demultiplexing. The demultiplexed bits may be descrambled and provided to the MAC layer (processor 206) for processing, evaluation, or interpretation.

[0079] The radio 204 generally includes at least one radio frequency (RF) transmitter (or "transmitter chain") and at least one RF receiver (or "receiver chain"), which may be combined into one or more transceivers. For example, the RF transmitter and receiver may include various DSP circuit systems, including at least one power amplifier (PA) and at least one low noise amplifier (LNA), respectively. The RF transmitter and receiver may in turn be coupled to one or more antennas. For example, in some implementations, the wireless communication device 200 may include or be coupled to multiple transmit antennas (each having a corresponding transmit chain) and multiple receive antennas (each having a corresponding receive chain). The codewords output from the modem 202 are provided to the radio 204, which transmits the codewords via the coupled antennas. Similarly, the codewords received via the antennas are obtained by the radio 204, which provides the codewords to the modem 602.

[0080] The processor 206 may include an intelligent hardware block or device designed to perform the functions described herein, such as, for example, a processing core, a processing block, a central processing unit (CPU), a microprocessor, a microcontroller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD) (such as a field programmable gate array (FPGA)), discrete gate or transistor logic, discrete hardware components, or any combination thereof. The processor 206 processes information received through the radio 204 and the modem 202, and processes information to be output by the modem 202 and the radio 204 for transmission over a wireless medium. For example, the processor 206 may implement a control plane and a MAC layer, which is configured to perform various operations related to the generation and transmission of MPDUs, frames, or packets. The MAC layer is configured to perform or facilitate encoding and decoding of frames, spatial multiplexing, space-time block coding (STBC), beamforming, and OFDMA resource allocation, and other operations or techniques. In some implementations, the processor 206 may generally control the modem 202 to cause the modem to perform various operations described herein.

[0081] The memory 204 may include a tangible storage medium, such as a random access memory (RAM) or a read-only memory (ROM) or a combination thereof. The memory 204 may also store non-transient processor or computer executable software (SW) code containing instructions that, when executed by the processor 206, cause the processor to perform various operations for wireless communication described herein, including generation, transmission, reception, and interpretation of MPDUs, frames, or packets. For example, the various functions of the various components disclosed herein or the various blocks or steps of the methods, operations, processes, or algorithms disclosed herein may be implemented as one or more modules of one or more computer programs.

[0082] Figure 3A 302 is a block diagram of an example AP 302. For example, the AP 302 may be a reference Figure 1 An example implementation of the AP 102 is described. The AP 302 includes a wireless communication device (WCD) 310 (although the AP 302 itself may also be generally referred to as a wireless communication device, as used herein). For example, the wireless communication device 310 may be a wireless communication device (WCD) 310. Figure 2An example implementation of the wireless communication device 200 described. The AP 302 also includes a plurality of antennas 320 coupled to the wireless communication device 310 to transmit and receive wireless communications. In some implementations, the AP 302 additionally includes an application processor 330 coupled to the wireless communication device 310, and a memory 340 coupled to the application processor 330. The AP 302 further includes at least one external network interface 350, which enables the AP 302 to communicate with a core network or a backhaul network to obtain access to an external network including the Internet. For example, the external network interface 350 may include one or both of a wired (e.g., Ethernet) network interface and a wireless network interface (such as a WWAN interface). Components in the aforementioned components may communicate directly or indirectly with other components in these components on at least one bus. The AP 302 further includes a housing that encloses the wireless communication device 310, the application processor 330, the memory 340, and encloses at least a portion of the antenna 320 and the external network interface 350.

[0083] In some implementations, the application processor 330 may be a component of a processing system. A processing system may generally refer to a system or series of machines or components that receives inputs and processes those inputs to produce a set of outputs that may be passed to other systems or components such as the AP 302. For example, the processing system of the AP 302 may refer to a system that includes various other components or subcomponents of the AP 302.

[0084] The processing system of AP 302 may interface with other components of AP 302, and may process information (such as input or signals) received from other components, output information to other components, etc. For example, a chip or modem of AP 302 may include a processing system, a first interface for outputting information, and a second interface for obtaining information. In some instances, the first interface may refer to an interface between a processing system of a chip or modem and a transmitter so that AP 302 can transmit information output from the chip or modem. In some instances, the second interface may refer to an interface between a processing system of a chip or modem and a receiver so that AP 302 can obtain information or signal input, and the information can be passed to the processing system. One of ordinary skill in the art will readily appreciate that the first interface may also obtain information or signal input, and the second interface may also output information or signal output.

[0085] Figure 3B 304. For example, STA 304 may be a reference Figure 1 104. STA 304 includes a wireless communication device 315 (although STA 304 itself may also be generally referred to as a wireless communication device, as used herein). For example, wireless communication device 315 may be a wireless communication device. Figure 2 An example implementation of the wireless communication device 200 described. The STA 304 also includes one or more antennas 325 coupled to the wireless communication device 315 to transmit and receive wireless communications. The STA 304 additionally includes an application processor 335 coupled to the wireless communication device 315, and a memory 345 coupled to the application processor 335. In some implementations, the STA 304 further includes a user interface (UI) 355 (such as a touch screen or keyboard) and a display 365, which can be integrated with the UI 355 to form a touch screen display. In some implementations, the STA 304 can further include one or more sensors 375 (such as one or more inertial sensors, accelerometers, temperature sensors, pressure sensors, or altitude sensors, for example). Components of the aforementioned components can communicate directly or indirectly with other components of these components on at least one bus. The STA 304 further includes a housing that encloses the wireless communication device 315, the application processor 335, the memory 345, and at least portions of the antenna 325, the UI 355, and the display 365.

[0086] In some implementations, the application processor 335 may be a component of a processing system. A processing system may generally refer to a system or series of machines or components that receives inputs and processes those inputs to produce a set of outputs that may be passed to other systems or components such as the STA 304. For example, the processing system of the STA 304 may refer to a system that includes various other components or subcomponents of the STA 304.

[0087] The processing system of STA 304 can interface with other components of STA 304, and can process information (such as input or signal) received from other components, output information to other components, etc. For example, a chip or modem of STA 304 may include a processing system, a first interface for outputting information, and a second interface for obtaining information. In some instances, the first interface may refer to an interface between the processing system of the chip or modem and a transmitter, so that STA 304 can transmit information output from the chip or modem. In some instances, the second interface may refer to an interface between the processing system of the chip or modem and a receiver, so that STA 304 can obtain information or signal input, and the information can be passed to the processing system. Those of ordinary skill in the art will readily appreciate that the first interface may also obtain information or signal input, and the second interface may also output information or signal output.

[0088] As mentioned, wireless communication devices may contend with each other to gain access to a shared wireless medium. The IEEE 802.11 standard defines a distributed coordination function (DCF), in which a wireless communication device uses a carrier sensing technique to determine that the wireless medium has been idle for a period of time before attempting to transmit data on the wireless medium. Many wireless communication devices employ an enhanced distributed channel access (EDCA) mechanism to perform medium access contention operations. The EDCA mechanism is an example of a listen-before-talk (LBT) channel access mechanism, and can prevent multiple devices from accessing the wireless medium simultaneously by arbitrating access to the wireless medium using a randomly selected number representing a period of time during which the wireless medium is to remain idle before a given wireless communication device can transmit on the wireless medium. The EDCA mechanism also provides several quality of service (QoS) enhancements for, for example, prioritizing data traffic flows in a network by defining four access categories (ACs): voice (AC_VO), video (AC_VI), background (AC_BK), and best effort (AC_BE).

[0089] As the number of wireless communication devices associated with an AP increases, the likelihood of collisions on the wireless medium also increases, which may reduce the throughput of the wireless network. The ability to provide a certain quality of service (QoS) in a wireless network may depend on the throughput of the wireless network. A reduction in the UL throughput or DL ​​throughput of a wireless network may reduce the ability of the AP to guarantee a certain level of QoS for time-critical traffic flows (such as voice and video calls). In addition, the presence of legacy devices in a wireless network that do not support multiple access communication mechanisms (such as orthogonal frequency division multiple access (OFDMA) modulation schemes) may cause a greater reduction in DL throughput than UL throughput, and may therefore exacerbate the imbalance between the UL throughput and DL throughput of the wireless network. The imbalance between UL throughput and DL throughput may restrict or limit the number of bidirectional symmetric traffic flows (such as voice and video calls) that the wireless network can support for a given number of associated devices.

[0090] Figure 4 A timing diagram 400 illustrating the transmission of a communication is shown. The communication may be associated with a medium access contention operation. In some implementations, reference Figure 4 The wireless communication device D1 described may operate as a STA or within a STA, such as with reference to Figure 1 and 3B In some other implementations, the wireless communication device D1 may operate as an AP or within an AP, such as with reference to FIG. Figure 1 and Figure 3A One of the APs 102 and 302 is depicted.

[0091] In some implementations, device D1 and one or more other wireless devices (not shown for simplicity) may use an EDCA mechanism to contend for medium access, which may be implemented through the use of CSMA / CA and timing intervals such as SIFS, DIFS, EIFS, and AIFS. For example, device D1 may randomly select or generate a backoff number from a range of numbers defined by a contention window (CW), and may set its backoff counter to an initial value based on the randomly selected backoff number. The size of the contention window may be initially set to a minimum value (CW min ), for example, so that the backoff number is from 0 to CW min Randomly select from a range of numbers between .

[0092] Device D1 may sense the wireless medium and decrement its backoff counter by one slot each time the wireless medium remains idle for an appropriate IFS period, such as a DIFS period. When the backoff counter reaches zero, device D1 may become the owner of the TXOP and transmit UL data on the wireless medium for the duration of the TXOP. If there is a collision on the wireless medium, device D1 uses an exponential backoff procedure in which the CW size is doubled for each subsequent medium access contention operation. When the contention window reaches a maximum value (CW max ), the contention window size remains at CW max , until one of the contending devices wins access to the shared wireless medium. One or more other wireless devices contending for the wireless medium follow a similar procedure and increment their backoff counters from 0 to CW every time the wireless medium is sensed to be idle for an appropriate IFS period. min The backoff number is randomly selected in decreasing order.

[0093] Reference Figure 4 At time t0, a listening period 410 begins during which device D1 listens or determines whether the wireless medium is idle or busy. Device D1 senses that the wireless medium is busy between time t0 and t1, and may defer medium access contention operations. The wireless medium becomes idle at time t1, and remains idle until at least time t2. Device D1 senses that the wireless medium has been idle for a DIFS period between time t1 and t2, decrements its backoff counter by one time slot, and enters a contention period 420 at time t2.

[0094] During the contention period 420, device D1 may contend with one or more other wireless devices for medium access. Device D1 and each of the one or more other wireless devices wait for a period of time determined by their respective randomly selected backoff numbers before attempting to transmit on the wireless medium. Each of the randomly selected backoff numbers may be a number of slot times ST1-ST2 within the contention window 425. NOne of the following, and may indicate a backoff period for a corresponding contending device. The contending device with the lowest backoff number is selected to have the shortest backoff period and "wins" the medium access contention operation. Figure 4 For example, device D1 selects the lowest backoff number (which corresponds to the time slot ST1-ST N Device D1 may transmit UL data 435 on the wireless medium during the duration of TXOP 430 between time t3 and time t4.

[0095] Figure 5 A timing diagram 500 illustrating the transmission of a communication is shown. In some implementations, reference Figure 5 The first wireless communication device ("AP") described may operate as an AP or within an AP, such as with reference to Figure 1 and 3A One of the APs 102 and 302 described above, and a second wireless communication device ("STA") may operate as a STA or within a STA, such as with reference to Figure 1 and 3B One of the STAs 104 and 304 described herein. In some implementations, Figure 5 Communications may be associated with the acquisition of data having different priority levels or being assigned different traffic identifiers (TIDs). Each TID indicates the priority level of the data and may be mapped to one of four access categories: voice (AC_VO), video (AC_VI), "best effort" (AC_BE), and background (AC_BK). Figure 5 , assuming that all ACs of the STA are enabled for Unscheduled Automatic Power Save Delivery (U-APSD). The U-APSD mechanism allows the STA to fetch DL data from the AP using a trigger frame that initiates an unscheduled service period with the AP at any time (such as without waiting for a beacon frame).

[0096] At time t0, the AP broadcasts a beacon frame carrying a Delayed Traffic Indication Map (DTIM), which may indicate the start of a DTIM period. The STA wakes up from an idle state at the start of the DTMI period to receive the beacon frame and decode the DTIM. If the AP asserts the DTIM bit corresponding to the STA, the STA may determine that the AP has buffered DL data for delivery to the STA.

[0097] After decoding the DTIM and determining that there is buffered DL data in the AP, the STA contends for medium access in order to obtain or request DL data from the AP. In some implementations, when the AP sets the MU EDCA timer to a relatively high value, the STA may use a trigger frame with a lower priority than the buffered DL data to initiate the delivery of DL data, for example, to increase the duration of the STA backoff period. Specifically, although AC_VO and AC_VI data are buffered in the AP, the STA may use an AC_BE trigger frame to obtain DL data from the AP. The AC_BE trigger frame may obtain data with the same or higher priority, and thus may initiate DL delivery of AC_BE data, AC_VI data, and AC_VO data. Accordingly, when contending for medium access, the STA may determine to wait for the AIFS duration associated with the AC_BE data, rather than the AIFS duration associated with the AC_VI and AC_VO data. The AIFS duration may be based on the AIFS number (AIFSN), the slot time (ST), and the short interframe space (SIFS) duration. The AIFSN may be based on the access category to which the data is assigned. In general, the AIFS duration can be expressed as AIFS=AIFSN[AC]*ST+SIFS, where AIFSN[AC] is the AIFS number of the access category (such as AC_BE) transmitting data.

[0098] At time t3, the STA wins access to the shared medium and transmits an AC_BE trigger frame to the AP, which initiates an unscheduled service period (such as from time t3-t9) during which the AP can deliver AC_BE data, AC_VI data, and AC_VO data to the STA. In some implementations, the AC_BE trigger frame can be a QoS Null frame identified with or otherwise associated with a best-effort access category. The AP responds to the AC_BE trigger by sending an acknowledgment (ACK) frame back to the STA (such as at time t4) and then sending the buffered DL data.

[0099] The AP sends an AC_VO data frame to the STA (such as at time t5) and waits for an acknowledgment from the STA. The "more data" bit may be asserted (MD[1]) through the AC_VO data frame, indicating that the AP has additional data to send to the STA. The STA responds to the AC_VO data frame by sending an ACK frame back to the AP (such as at time t6) to confirm the receipt of the AC_VO data frame. The AP sends an AC_VI data frame to the STA (such as at time t7) and again waits for an acknowledgment from the STA. The "more data" bit may be deasserted (MD[0]) in the AC_VI data frame, indicating that the AP has no more data to send to the STA. The STA responds to the AC_VI data frame by sending an ACK frame to the AP (such as at time t8) and then returning to a low-power idle state (such as at time t9), ending the service period.

[0100] Figure 6 A timing diagram 600 illustrating the transmission of a communication is shown. The communication may be associated with MU channel access. In some implementations, reference Figure 6 The first wireless communication device ("AP") described may operate as an AP or within an AP, such as with reference to Figure 1 and 3A One of the APs 102 and 302 described above, and each of the plurality of wireless communication devices (STA1-STA4) may operate as a STA or within a STA, such as referring to the respective Figure 1 and 3B One of the STAs 104 and 304 described. Although Figure 6 The example of shows four STAs associated with an AP, but any number of STAs may be associated with an AP. At least some of the STAs may have the capability to operate in a power save mode.

[0101] Prior to time t0, each of STA1-STA4 ("STAs") is associated with the AP. Between time t0 and t1, each of the STAs transmits a number of packets (such as a number of UL PPDUs), receives a number of packets (such as a number of DL PPDUs), or both. Also between time t0 and time t1, each of the STAs enters a power saving mode and exits the power saving mode a certain number of times. Figure 6 In an example of , the AP receives one or more indications from each respective STA that the respective STA will enter a power saving mode. In some implementations, one or more of these indications are power management (PM) bits carried in a quality of service (QoS) NULL packet. The respective STA may set the PM bit to 1 to indicate that it will enter a power saving mode.

[0102] Also between time t0 and time t1, the AP may generate, for each respective STA, behavior statistics indicating the power saving behavior of the respective STA. For example, the AP may determine, for each respective STA, the duration between the first time the respective STA transmits or receives data (such as within a QoS NULL packet) and the second time the respective STA enters a power saving mode. For each respective STA, the duration may be fixed, variable, or both. In some instances, the duration may be on the order of milliseconds (ms).

[0103] In some implementations, the AP may determine, for each respective STA, an average duration between a plurality of first times at which the respective STA transmits or receives data and a corresponding plurality of second times at which the respective STA enters a power saving mode. The AP may estimate a power saving schedule for each respective STA based on the average duration. In some implementations, instead of determining the average duration for each respective STA, the AP may generate a parameterized duration for each respective STA and estimate a power saving schedule for each respective STA based on the parameterized duration.

[0104] Based on the generated statistics, the AP may adjust one or more parameters of a multi-user (MU) channel access mechanism for transmitting uplink (UL) data based on the generated behavior statistics and transmit a beacon advertising the one or more adjusted parameters 602. For example, the one or more parameters may include a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size (CW Min ), or at least one of a maximum CW size.

[0105] In some implementations, the AP may determine the percentage of STAs that enter power saving mode within a specific duration (such as 10ms) after transmitting or receiving data based on the determined average duration. If the percentage is greater than a value, the AP may reduce at least one of the MU EDCA timer value, AIFSN, minimum CW size, or maximum CW size. If the percentage is less than a value, the AP may refrain from adjusting one or more parameters, or in some instances, the AP may increase at least one of these parameters. As a non-limiting example, if the AP determines that more than 75% of the STAs enter power saving mode within 20ms after transmitting or receiving data, the AP may reduce the MU EDCA timer value so that more than 75% of the STAs can contend for medium access more frequently, thereby reducing overall network latency. As another non-limiting example, the AP may determine that less than 25% of the STAs enter power saving mode within less than 10ms after transmitting or receiving data. In such instances, based on the AP's TBTT scheduling, the AP may refrain from reducing the MU EDCA timer value. In some of such instances, the AP may reduce overall network latency by increasing the MU EDCA timer value.

[0106] In some implementations, also between time t0 and time t1, the AP may determine at least one of: (i) the average frequency at which the corresponding STA queues UL data for transmission to the AP; (ii) the average frequency at which the corresponding STA transmits its UL data queue size to the AP when exiting a power saving mode; or (iii) the average duration between the time when the corresponding STA exits power saving mode and the time when the corresponding STA transmits its UL data queue size to the AP, in addition to or in lieu of (iv) the average duration between the time when the corresponding STA transmits or receives data and the time when the corresponding STA enters power saving mode, as described herein, and adjust one or more parameters based on at least one of (i), (ii), (iii), or (iv). At time t1, the AP may transmit a beacon 602 advertising one or more adjusted parameters. The AP and STA may thereafter operate according to the adjusted parameters, or until the AP advertises further adjusted parameters in a subsequent beacon (not shown for simplicity). Figure 6 In the example of , STA2 and STA4 enter the power saving mode at time t2.

[0107] As a non-limiting example, the AP may determine that (iv) of the corresponding STA is greater than a value and (i) of the corresponding STA is less than a value. In such an implementation, the AP may reset the BSR trigger timer and transmit a buffer status report poll (BSRP) that triggers the corresponding STA to transmit a BSR to the AP. Figure 6In the example of , the AP determines that (iv) of STA1 is greater than a value and (i) of STA1 is less than a value. Thus, the AP transmits a BSRP (such as BSRP 610 at time t6) to STA1, triggering STA1 to transmit a BSR (such as BSR 612 at time t7) to the AP.

[0108] As another non-limiting example, the AP may determine that (iv) of the corresponding STA is greater than a value and (i) of the corresponding STA is greater than a value. In such an implementation, when the AP receives a QoS NULL packet with the PM bit set to 0 from the corresponding STA, the AP may transmit a buffer status report (BSR) trigger frame that triggers the corresponding STA to transmit buffer status information upon exiting power saving mode. Figure 6 In the example of , the AP determines that (iv) of STA2 is greater than a value and (i) of STA2 is greater than a value. Thus, when STA2 exits power save mode and transmits a QoS NULL packet with the PM bit set to 0 to the AP (such as at time t 11 When the QoS NULL packet 622 is transmitted, the AP transmits a trigger STA2 to transmit the buffer status information (such as at time t 13 The buffer information 624) of the BSR trigger frame (such as at time t 12 BSR trigger frame 620).

[0109] As another non-limiting example, the AP may determine that (iv) of the corresponding STA is less than a value and (i) of the corresponding STA is greater than a value. In such an implementation, the AP may thus include the corresponding STA in a scheduling candidate set for a UL basic trigger and transmit a basic trigger frame that triggers the corresponding STA to transmit UL QoS information upon exiting a power saving mode. Figure 6 In the example of FIG. 5 , the AP determines that (iv) of STA4 is less than a value and (i) of STA4 is greater than a value. Thus, when STA4 exits the power save mode and transmits a QoS NULL packet with the PM bit set to 0 to the AP (such as QoS NULL packet 642 at time t8), the AP transmits a packet that triggers STA4 to transmit UL QoS information (such as at time t9). 10 A basic trigger frame (such as the basic trigger frame 640 at time t9) containing UL QoS information 644.

[0110] In some implementations, the corresponding STA may transmit an unsolicited BSR to the AP upon waking up from a power saving mode in response to the duration of the MU EDCA timer value exceeding a period of time. Figure 6In the example of , STA3 transmits an unsolicited BSR (such as BSR 632 at time t3) to the AP based on the modified MU EDCA timer exceeding a value. In some implementations, BSR 632 is a QoS NULL packet that includes buffer status for up to two STA2 backlogged traffic identifiers (TIDs). That is, BSR 632 may indicate buffer status information for STA2 for at least one access category (AC) (such as AC_VI, AC_VO, or both) that is not affected by the MU EDCA timer value. Thereafter, the AP transmits a trigger frame (such as trigger frame 630 at time t4) to trigger STA2 to transmit its backlogged TID to the AP in one or more UL PPDUs (such as (s) UL PPDU 634 at time t5). The UL PPDU may include, for example, STA3's backlogged AC_VI UL data, AC_VO UL data, or both. In some implementations, if one or more of the AC_VI UL data and the AC_VO UL data is insufficient to fill all of the one or more UL PPDUs, STA3 may insert data for at least one other AC (such as AC_BE, AC_BK, or both) affected by the MU EDCA timer value. In this way, STA3 may suppress the insertion of wasteful padding in one or more UL PPDUs.

[0111] In some implementations not shown, the corresponding STA may operate in one of a plurality of different power saving modes, such as a first power saving mode or a second power saving mode. In such implementations, the corresponding STA may increase a power saving timer in response to receiving a trigger frame from the AP when the STA is operating in the first power saving mode. Additionally or alternatively, the AP may refrain from transmitting one or more trigger frames to the corresponding STA when the corresponding STA is operating in the second power saving mode.

[0112] Figure 7 A flow chart illustrating example operations 700 for wireless communications supporting a multi-user channel access mechanism is shown. Operations 700 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 700 may be performed by a wireless communication device 200 as an AP (such as the wireless communication device 200 described in the respective embodiments). Figure 1 and Figure 3B The method is performed by a wireless communication device operating with or within one of the described APs 102 and 302.

[0113] At block 702, the wireless communication device receives one or more indications from each respective STA of a plurality of wireless stations (STAs) associated with an AP that the respective STA is to enter a power save mode.

[0114] At block 704, the wireless communication device selects, for each respective STA of the plurality of STAs, a duration between a first time at which the respective STA transmits or receives data and a second time at which the respective STA enters a power saving mode.

[0115] At block 706, the wireless communication device adjusts one or more parameters associated with the selected duration of a multi-user (MU) channel access mechanism for transmitting uplink (UL) data.

[0116] In some implementations, at least one of the one or more indications is a power management (PM) bit carried in a media access control (MAC) frame, and the PM bit is set to 1. In some instances, the MAC frame is a quality of service (QoS) NULL frame. In some other instances, the determined duration is an average duration between a plurality of first times at which the corresponding STA transmits or receives data and a corresponding plurality of second times at which the corresponding STA enters a power saving mode. In some implementations, the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between transmissions of trigger frames to the corresponding STA.

[0117] Fig. 8A A flow chart illustrating example operations 800 for wireless communications supporting a multi-user channel access mechanism is shown. Operations 800 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 800 may be performed by a wireless communication device 200 as an AP (such as the wireless communication device 200 described in the respective embodiments). Figure 1 and Figure 3B The operation 800 may be performed by a wireless communication device operating with or within the AP 102 or one of the APs 102 and 302 described herein. For example, the operation 800 may be performed after receiving one or more indications in block 702 of the operation 700.

[0118] At block 802, the wireless communication device transmits a buffer status report (BSR) trigger frame that triggers the corresponding STA to transmit buffer status information upon exiting a power saving mode. In some implementations, at least one of the one or more indications is a PM bit carried in a media access control (MAC) frame. In some instances, the PM bit is set to 0.

[0119] Figure 8B A flow chart illustrating example operations 810 for wireless communication supporting a multi-user channel access mechanism is shown. Operation 810 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 810 may be performed by a wireless communication device 200 as an AP (such as the wireless communication device 200 described in the examples). Figure 1 and Figure 3B The method may be performed by a wireless communication device operating with or within the AP 102 or one of the APs 102 and 302 described herein. For example, operation 810 may be an implementation of adjusting one or more parameters in block 706 of operation 700.

[0120] At block 812, the wireless communication device decreases at least one of a MU EDCA timer value, an AIFSN, a minimum CW size, or a time interval based on the determined duration for at least some of the plurality of STAs being greater than a value.

[0121] Figure 8C A flow chart illustrating example operations 820 for wireless communication supporting a multi-user channel access mechanism is shown. Operation 820 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 820 may be performed by a wireless communication device 200 as an AP (such as the wireless communication device 200 described in the respective embodiments). Figure 1 and Figure 3B For example, operation 820 may be performed during or after adjusting one or more parameters in block 706 of operation 700.

[0122] At block 822, the wireless communication device sets the MU EDCA timer value to a duration.

[0123] At block 824, the wireless communication device receives an unsolicited BSR from at least one of the plurality of STAs based on the duration of the MU EDCA timer value exceeding a period of time.

[0124] Fig.8D A flow chart illustrating example operations 830 for wireless communication supporting a multi-user channel access mechanism is shown. Operation 830 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 830 may be performed by a wireless communication device 200 as an AP (such as the wireless communication device 200 described in the respective embodiments). Figure 1 and Figure 3B The wireless communication device may be operated by or within the AP 102 or one of the APs 102 and 302 described herein. For example, operation 830 may be an implementation of adjusting one or more parameters in block 706 of operation 700.

[0125] At block 832, the wireless communication device adjusts a time interval between transmissions of triggered frames to the respective STA based at least in part on the determined duration of the respective STA.

[0126] Fig. 8EA flow chart illustrating example operations 840 for wireless communication supporting a multi-user channel access mechanism is shown. Operation 840 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 840 may be performed by a wireless communication device 200 as described in the foregoing description. Figure 1 and Figure 3B The operation 840 may be performed by a wireless communication device operating with or within the AP 102 or one of the APs 102 and 302 described herein. For example, operation 840 may be performed after a duration is selected in block 704 of operation 700.

[0127] At block 842, the wireless communication device selects an average frequency at which the corresponding STA queues UL data for transmission to the AP, wherein dynamically adjusting the one or more parameters is further based on the determined average frequency.

[0128] Fig.8F A flow chart illustrating example operations 850 for wireless communication supporting a multi-user channel access mechanism is shown. Operation 850 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 850 may be performed by a wireless communication device 200 as an AP (such as the wireless communication device 200 described in the respective embodiments). Figure 1 and Figure 3B The wireless communication device may be operated by or within the AP 102 or one of the APs 102 and 302 described herein. For example, operation 850 may be an implementation of adjusting one or more parameters in block 706 of operation 700.

[0129] At block 852, the wireless communication device estimates a power saving schedule for each respective STA in the plurality of STAs based at least in part on the one or more indications, wherein dynamically adjusting the one or more parameters is further based on the estimated power saving schedules for the plurality of STAs. In some instances, the estimated power saving schedules for the respective STAs indicate a likelihood that the respective STA has queued UL data.

[0130] Figure 8G A flow chart illustrating example operations 860 for wireless communication supporting a multi-user channel access mechanism is shown. Operation 860 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 860 may be performed by a wireless communication device 200 as an AP (such as the wireless communication device 200 described in the accompanying drawings). Figure 1 and Figure 3BThe method may be performed by a wireless communication device operating with or within an AP (one of the APs 102 and 302 described herein). For example, operation 860 may be performed after estimating a power saving schedule in block 852 of operation 850. In some implementations, the estimated power saving schedule of the corresponding STA may indicate whether the corresponding STA is to transmit its UL data queue size to the AP when exiting a power saving mode.

[0131] At block 862, the wireless communication device selects, for the respective STA, an average duration between a first time at which the respective STA exits a power saving mode and a second time at which the respective STA transmits its UL data queue size to the AP.

[0132] At block 864, the wireless communication device includes the corresponding STA in a scheduling candidate set for a UL basic trigger when the determined average duration is less than a value.

[0133] At block 866, the wireless communication device transmits a basic trigger frame that triggers the corresponding STA to transmit UL QoS information upon exiting the power save mode.

[0134] Figure 8H A flow chart illustrating example operations 870 for wireless communication supporting a multi-user channel access mechanism is shown. Operation 870 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 870 may be performed by a wireless communication device 200 as an AP (such as the wireless communication device 200 described in the respective embodiments). Figure 1 and Figure 3B The method may be performed by a wireless communication device operating with or within an AP (one of the APs 102 and 302 described herein). For example, operation 870 may be performed after estimating a power saving schedule in block 852 of operation 850. In some implementations, the estimated power saving schedule of the corresponding STA may indicate whether the corresponding STA is to transmit its UL data queue size to the AP when exiting a power saving mode.

[0135] At block 872, the wireless communication device selects, for the respective STA, an average duration between a first time at which the respective STA exits a power saving mode and a second time at which the respective STA transmits its UL data queue size to the AP.

[0136] At block 874, the wireless communication device transmits a BSR trigger frame that triggers the corresponding STA to transmit buffer status information upon exiting the power saving mode when the determined average duration is greater than a value.

[0137] Figure 8I A flow chart illustrating example operations 880 for wireless communications supporting a multi-user channel access mechanism is shown. Operation 880 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2In some implementations, operation 880 may be performed by a wireless communication device 200 as an AP (such as the wireless communication device 200 described in the respective embodiments). Figure 1 and Figure 3B The operation 880 may be performed by a wireless communication device operating with or within the AP 102 or one of the APs 102 and 302 described herein. For example, operation 880 may be performed after adjusting one or more parameters in block 706 of operation 700.

[0138] At block 882, the wireless communication device transmits a basic trigger frame that triggers one or more of the plurality of STAs to transmit UL QoS information upon exiting a power save mode when the determined duration is less than a value.

[0139] Figure 8J A flow chart illustrating example operations 890 for wireless communication supporting a multi-user channel access mechanism is shown. Operation 890 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 890 may be performed by a wireless communication device 200 as an AP (such as the wireless communication device 200 described in the respective embodiments). Figure 1 and Figure 3B The operation 890 may be performed by a wireless communication device operating with or within the AP 102 or one of the APs 102 and 302 described herein. For example, operation 890 may be performed after adjusting one or more parameters in block 706 of operation 700.

[0140] At block 892, the wireless communication device transmits a BSRP trigger frame that triggers one or more of the plurality of STAs to transmit buffer status information upon exiting a power save mode when the determined duration is greater than a value.

[0141] Fig. 9 A flow chart illustrating example operations 900 for wireless communications supporting a multi-user channel access mechanism is shown. Operations 900 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 900 may be performed by a STA (such as a wireless communication device 200 described in detail in the accompanying drawings). Figure 1 and Figure 3B The method is performed by a wireless communication device operating with or within the STA 104 and 304 described herein.

[0142] At block 902, the wireless communication device transmits one or more indications to a wireless access point (AP) that the STA is to enter a power save mode.

[0143] At block 904, the wireless communication device communicates data at each first time instant in a plurality of first time instants.

[0144] At block 906, the wireless communication device enters a power save mode at each second time instant in a plurality of second time instants.

[0145] At block 908, the wireless communication device receives a beacon from the AP indicating one or more parameters for a multi-user (MU) channel access mechanism to transmit uplink (UL) data.

[0146] In some implementations, the duration indicates an average duration between corresponding pairs of the first and second moments. In some instances, at least one of the one or more indications is a power management (PM) bit carried in a media access control (MAC) frame, and the PM bit is set to 1. In some other instances, the MAC frame is a quality of service (QoS) NULL frame. In some implementations, the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between each trigger frame transmission to the STA. In some instances, at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is set based on at least one of the duration between the corresponding pair of the first and second moments being greater than a value, the possibility that the STA has queued UL data, or the average frequency with which the STA queues UL data for transmission to the AP.

[0147] Fig. 10A A flow chart illustrating example operations 1000 for wireless communications supporting a multi-user channel access mechanism is shown. Operations 1000 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, the operations 1000 may be performed by a STA (such as a wireless communication device 200 described in the accompanying drawings). Figure 1 and Figure 3B The operation 1000 may be performed by a wireless communication device operating with or within a STA (one of the STAs 104 and 304 described herein). For example, the operation 1000 may be performed after entering a power saving mode in block 906 of the operation 900. In some implementations, at least one of the one or more indications is a PM bit carried in a medium access control (MAC) frame, and the PM bit is set to 0.

[0148] At block 1002, the wireless communication device receives a buffer status report (BSR) trigger frame that triggers the STA to transmit buffer status information to the AP upon exiting a power save mode.

[0149] Fig. 10B A flow chart illustrating example operations 1010 for wireless communications supporting a multi-user channel access mechanism is shown. Operations 1010 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 1010 may be performed by a STA (such as a wireless communication device 200 described in the accompanying drawings). Figure 1 and Figure 3B The operation 1010 may be performed by a wireless communication device operating with or within the STA described herein. For example, operation 1010 may be performed after receiving the beacon in block 908 of operation 900. In some implementations, at least one of the one or more parameters indicates a duration of a MU EDCA timer value.

[0150] At block 1012, the wireless communication device transmits an unsolicited BSR to the AP based on the duration of the MU EDCA timer value exceeding a period of time, wherein the unsolicited BSR indicates buffer status information for at least one access category (AC) not affected by the MU EDCA timer value.

[0151] Fig. 10C A flow chart illustrating example operations 1020 for wireless communication supporting a multi-user channel access mechanism is shown. Operation 1020 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2 In some implementations, operation 1020 may be performed by a STA (such as a wireless communication device 200 described in the accompanying drawings). Figure 1 and Figure 3B The operation 1020 may be performed by a wireless communication device operating with or within the STA (one of the STAs 104 and 304 described above). For example, operation 1020 may be performed after entering the power saving mode in block 906 of operation 900. In some implementations, at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is set based on an average duration between a first time when the STA exits the power saving mode and a second time when the STA transmits its UL data queue size to the AP.

[0152] At block 1022, the wireless communication device receives a basic trigger frame that triggers the STA to transmit UL QoS information to the AP upon exiting a power save mode when the average duration is less than a value.

[0153] At block 1024, the wireless communication device receives a BSRP trigger frame that triggers the STA to transmit buffer status information to the AP upon exiting power save mode when the average duration is greater than the value.

[0154] Fig. 10D A flow chart illustrating example operations 1030 for wireless communication supporting a multi-user channel access mechanism is shown. Operation 1030 may be performed by a wireless communication device (such as a wireless communication device such ... Figure 2In some implementations, operation 1030 may be performed by a STA (such as a wireless communication device 200 described in the accompanying drawings). Figure 1 and Figure 3B The operation 1030 may be performed by a wireless communication device operating with or within the STA 104 or 304 described herein. For example, the operation 1030 may be performed after entering the power saving mode in block 906 of the operation 900.

[0155] At block 1032, the wireless communication device increases a power save timer in response to receiving a trigger frame from the AP when the STA operates in a first power save mode and not receiving a trigger frame from the AP when the STA operates in a second power save mode.

[0156] Various implementation examples are described in the following numbered clauses.

[0157] 1. A method for wireless communication by a device of a wireless access point (AP), comprising: receiving one or more indications from each of a plurality of wireless stations (STA) associated with the AP that the respective STA will enter a power saving mode; selecting, for each of the plurality of STAs, a duration between a first moment at which the respective STA transmits or receives data and a second moment at which the respective STA enters the power saving mode; and adjusting one or more parameters associated with the selected duration of a multi-user (MU) channel access mechanism for transmitting uplink (UL) data.

[0158] 2. The method of clause 1, wherein the duration is an average duration between a plurality of first times at which the respective STA transmits or receives data and a corresponding plurality of second times at which the respective STA enters a power saving mode.

[0159] 3. A method as in any one or more of clauses 1-2, wherein at least one of the one or more indications comprises a power management (PM) bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 1.

[0160] 4. The method of clause 3, wherein the MAC frame is a Quality of Service (QoS) NULL frame.

[0161] 5. The method of any one or more of clauses 1-2, wherein at least one of the one or more indications comprises a PM bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 0, the method further comprising:

[0162] A buffer status report (BSR) trigger frame is transmitted which triggers the corresponding STA to transmit buffer status information upon exiting the power saving mode.

[0163] 6. A method as described in any one or more of clauses 1-5, wherein the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between each triggered frame transmission to the corresponding STA.

[0164] 7. The method of any one or more of clauses 1-6, wherein dynamically adjusting the one or more parameters comprises:

[0165] At least one of a MU EDCA timer value, an AIFSN, a minimum CW size, or a time interval is decreased based on the selected duration of at least some of the plurality of STAs being greater than a value.

[0166] 8. The method of clause 7, further comprising:

[0167] setting the MU EDCA timer value to a duration; and receiving an unsolicited BSR from at least one of the plurality of STAs based on the duration of the MU EDCA timer value exceeding a period of time.

[0168] 9. The method of any one or more of clauses 1-8, further comprising:

[0169] A time interval between transmissions of trigger frames to the respective STA is adjusted based at least in part on the determined duration of the respective STA.

[0170] 10. The method of any one or more of clauses 1-9, further comprising:

[0171] An average frequency at which the respective STA queues UL data for transmission to the AP is selected, wherein dynamically adjusting the one or more parameters is further based on the determined average frequency.

[0172] 11. The method of any one or more of clauses 1-10, further comprising:

[0173] A power saving schedule for each respective STA of the plurality of STAs is estimated based at least in part on the one or more indications, wherein dynamically adjusting the one or more parameters is further based on the estimated power saving schedules for the plurality of STAs.

[0174] 12. The method of clause 11, wherein the estimated power saving schedule of the respective STA indicates whether the respective STA is to transmit its UL data queue size to the AP when exiting power saving mode, the method further comprising:

[0175] an average duration between a first time when the corresponding STA selects the corresponding STA to exit the power saving mode and a second time when the corresponding STA transmits its UL data queue size to the AP;

[0176] including the corresponding STA in a scheduling candidate set for UL basic triggering when the determined average duration is less than a value; and

[0177] A basic trigger frame is transmitted which triggers the corresponding STA to transmit UL QoS information upon exiting the power saving mode.

[0178] 13. The method of clause 11, wherein the estimated power saving schedule of the respective STA indicates whether the respective STA is to transmit its UL data queue size to the AP when exiting power saving mode, the method further comprising:

[0179] An average duration between a first time when the respective STA selects the respective STA to exit the power saving mode and a second time when the respective STA transmits its UL data queue size to the AP; and

[0180] A BSR trigger frame is transmitted when the determined average duration is greater than a value, triggering the corresponding STA to transmit buffer status information upon exiting the power saving mode.

[0181] 14. The method of clause 11, wherein the estimated power saving schedule of the respective STA indicates a likelihood that the respective STA has queued UL data.

[0182] 15. The method of clause 1, further comprising:

[0183] A basic trigger frame is transmitted when the determined duration is less than a value to trigger one or more STAs of the plurality of STAs to transmit UL QoS information upon exiting a power saving mode.

[0184] 16. The method of clause 1, further comprising:

[0185] A buffer status report (BSR) trigger frame is transmitted when the determined duration is greater than a value, triggering one or more STAs of the plurality of STAs to transmit buffer status information upon exiting a power saving mode.

[0186] 17. A wireless communication device comprising means for performing the operations of any one or more of clauses 1-16.

[0187] 18. A non-transitory computer-readable memory comprising instructions that, when executed by one or more processors of a wireless communication device, cause the wireless communication device to perform the operations of any one or more of clauses 1-16.

[0188] 19. A wireless communication device, comprising:

[0189] interface, which is configured as:

[0190] obtaining one or more indications that a wireless station (STA) is to enter a power save mode; and

[0191] A processing system, the processing system being configured to:

[0192] selecting, for each respective STA of the plurality of STAs, a duration between a first time at which the respective STA transmits or receives data and a second time at which the respective STA enters a power saving mode; and

[0193] One or more parameters associated with the selected duration of a multi-user (MU) channel access mechanism used to transmit uplink (UL) data are adjusted.

[0194] 20. The wireless communication device of clause 19, wherein at least one of the one or more indications comprises a power management (PM) bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 1.

[0195] 21. The wireless communication device of clause 20, wherein the MAC frame is a Quality of Service (QoS) NULL frame.

[0196] 22. The wireless communications device of clause 19, wherein at least one of the one or more indications comprises a PM bit carried in a medium access control (MAC) frame, wherein the PM bit is set to zero, and wherein the interface is further configured to:

[0197] A buffer status report (BSR) trigger frame is output to trigger the corresponding STA to transmit buffer status information upon exiting the power saving mode.

[0198] 23. A wireless communication device as described in any one or more of clauses 19-22, wherein the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between each trigger frame transmission to the corresponding STA.

[0199] 24. The wireless communication device of any one or more of clauses 19-23, wherein dynamically adjusting the one or more parameters comprises:

[0200] At least one of a MU EDCA timer value, an AIFSN, a minimum CW size, or a time interval is decreased based on the selected duration of at least some of the plurality of STAs being greater than a value.

[0201] 25. The wireless communication device of any one or more of clauses 19-24, wherein the processing system is further configured to:

[0202] A power saving schedule for each respective STA of the plurality of STAs is estimated based at least in part on the one or more indications, wherein dynamically adjusting the one or more parameters is further based on the estimated power saving schedules for the plurality of STAs.

[0203] 26. A method for performing wireless communication by a device of a wireless station (STA), comprising:

[0204] transmitting one or more indications to a wireless access point (AP) that the STA will enter a power saving mode;

[0205] communicating data at each first time instant in a plurality of first time instants;

[0206] Entering a power saving mode at each second time in a plurality of second times; and

[0207] A beacon is received from the AP indicating one or more parameters for a multi-user (MU) channel access mechanism to transmit uplink (UL) data.

[0208] 27. A method as described in clause 26, wherein at least one of the one or more parameters is configured based on the duration between the corresponding pair of the first moment and the second moment, and wherein the duration indicates an average duration between the corresponding pair of the first moment and the second moment.

[0209] 28. The method of any one or more of clauses 26-27, wherein at least one of the one or more indications comprises a power management (PM) bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 1.

[0210] 29. The method of clause 28, wherein the MAC frame is a Quality of Service (QoS) NULL frame.

[0211] 30. The method of clause 26, wherein at least one of the one or more indications comprises a PM bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 0, the method further comprising:

[0212] A buffer status report (BSR) trigger frame is received that triggers the STA to transmit buffer status information to the AP upon exiting a power saving mode.

[0213] 31. A method as described in any one or more of clauses 26-30, wherein the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between each trigger frame transmission to the STA.

[0214] 32. A method as described in clause 31, wherein at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is set based on at least one of the duration between the corresponding pair of the first moment and the second moment being greater than a value, the likelihood that the STA has queued UL data, or the average frequency with which the STA queues UL data for transmission to the AP.

[0215] 33. The method of any one or more of clauses 31-32, wherein at least one of the one or more parameters indicates a duration of a MU EDCA timer value, the method further comprising:

[0216] An unsolicited BSR is transmitted to the AP based on the duration of the MU EDCA timer value exceeding a time period, wherein the unsolicited BSR indicates buffer status information for at least one access category (AC) not affected by the MU EDCA timer value.

[0217] 34. The method of any one or more of clauses 31-32, wherein at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is set based on an average duration between a first time the STA exits a power save mode and a second time the STA transmits its UL data queue size to the AP, the method further comprising:

[0218] receiving a basic trigger frame that triggers the STA to transmit UL QoS information upon exiting a power saving mode when the average duration is less than a value; and

[0219] A buffer status report (BSR) trigger frame is received when the average duration is greater than a value, triggering the STA to transmit buffer status information to the AP upon exiting a power saving mode.

[0220] 35. The method of clause 26, further comprising:

[0221] The power save timer is incremented in response to receiving a trigger frame from the AP when the STA operates in the first power save mode and not receiving a trigger frame from the AP when the STA operates in the second power save mode.

[0222] 36. The method of clause 26, further comprising:

[0223] The power save timer is incremented in response to receiving a trigger frame from the AP when the STA operates in the first power save mode and not receiving a trigger frame from the AP when the STA operates in the second power save mode.

[0224] 37. A wireless communication device comprising means for performing the operations of any one or more of clauses 26-36.

[0225] 38. A non-transitory computer readable memory comprising instructions that, when executed by one or more processors of a wireless communication device, cause the wireless communication device to perform the operations of any one or more of clauses 26-36.

[0226] 39. A wireless communication device, comprising:

[0227] interface, which is configured as:

[0228] outputting one or more indications that the wireless communication device will enter a power saving mode; and outputting or obtaining data at each first time in a plurality of first times;

[0229] A processing system, the processing system being configured to:

[0230] Entering a power saving mode at each second time in a plurality of second times; and

[0231] The interface is further configured to:

[0232] A beacon is obtained from the AP indicating one or more parameters to be used for a multi-user (MU) channel access mechanism to transmit uplink (UL) data.

[0233] 40. The wireless communications device of clause 39, wherein at least one of the one or more indications comprises a power management (PM) bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 1.

[0234] 41. The wireless communication device of clause 40, wherein the MAC frame is a Quality of Service (QoS) NULL frame.

[0235] 42. The wireless communications device of clause 39, wherein at least one of the one or more indications comprises a PM bit carried in a medium access control (MAC) frame, wherein the PM bit is set to zero, and wherein the interface is further configured to:

[0236] A buffer status report (BSR) trigger frame is obtained that triggers the wireless communication device to transmit buffer status information to the AP upon exiting a power save mode.

[0237] As used herein, a phrase referring to "at least one of" or "one or more of" a list of items refers to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to cover the following possibilities: only a, only b, only c, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a, b, and c.

[0238] The various illustrative components, logic, logic blocks, modules, circuits, operations, and algorithmic processes described in conjunction with the implementations disclosed herein may be implemented as electronic hardware, firmware, software, or a combination of hardware, firmware, or software, including the structures disclosed in this specification and their structural equivalents. The interchangeability of hardware, firmware, and software has been generally described in terms of their functionality and is illustrated in the various illustrative components, blocks, modules, circuits, and processes described herein. Whether such functionality is implemented in hardware, firmware, or software depends on the specific application and the design constraints imposed on the overall system.

[0239] Various modifications to the implementations described in this disclosure may be apparent to those of ordinary skill in the art, and the universal principles defined herein may be applied to other implementations without departing from the spirit or scope of the disclosure. Thus, the claims are not intended to be limited to the implementations shown herein, but should be granted the widest scope consistent with the disclosure, the principles and novel features disclosed herein.

[0240] In addition, various features described in this specification in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented in multiple implementations separately or in any suitable subcombination. Thus, while features may be described as functioning in a particular combination and even initially claimed as such, one or more features from a claimed combination may be removed from the combination in some cases, and a claimed combination may be directed to a subcombination, or a variation of a subcombination.

[0241] Similarly, although operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring such operations to be performed in the particular order shown or in a sequential order, or to perform all the operations described in order to achieve the desired result. In addition, the accompanying drawings may schematically depict one or more example processes in the form of a flow chart or a flow diagram. However, other operations not depicted may be incorporated into the example processes schematically illustrated. For example, one or more additional operations may be performed before, after, simultaneously or between any of the illustrated operations. In some environments, multitasking and parallel processing may be advantageous. In addition, the separation of various system components in the implementation described herein should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

Claims

1. A method for wireless communication performed by a device of a wireless access point (AP), comprising: receiving one or more indications from each respective STA of a plurality of wireless stations (STAs) associated with the AP that the respective STA is to enter a power save mode; as well as For each corresponding STA among the multiple STAs, one or more parameters of a multi-user (MU) channel access mechanism for transmitting uplink (UL) data are adjusted, wherein the one or more parameters are based on the duration between a first moment when the corresponding STA transmits or receives data and a second moment when the corresponding STA enters the power saving mode and based on the number of STAs among the multiple STAs for which the duration is greater than a value.

2. The method of claim 1, wherein at least one of the one or more indications comprises a power management (PM) bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 1.

3. The method of claim 2, wherein the MAC frame is a Quality of Service (QoS) NULL frame.

4. The method of claim 1 , wherein at least one of the one or more indications comprises a PM bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 0, the method further comprising: A buffer status report (BSR) trigger frame is transmitted which triggers the corresponding STA to transmit buffer status information upon exiting the power saving mode.

5. The method of claim 1, wherein the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between transmissions of trigger frames to the corresponding STA.

6. The method of claim 5, wherein adjusting the one or more parameters comprises: At least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is decreased.

7. The method of claim 1, further comprising: An average frequency at which the respective STA queues UL data for transmission to the AP is selected, wherein adjusting the one or more parameters is further based on the selected average frequency.

8. The method of claim 1, further comprising: A power saving schedule for each respective STA of the plurality of STAs is estimated based at least in part on the one or more indications, wherein adjusting the one or more parameters is further based on the estimated power saving schedules for the plurality of STAs.

9. The method of claim 8, wherein the estimated power saving schedule of the corresponding STA indicates whether the corresponding STA is to transmit its UL data queue size to the AP when exiting the power saving mode, the method further comprising: an average duration between a first time when the corresponding STA selects the corresponding STA to exit the power saving mode and a second time when the corresponding STA transmits its UL data queue size to the AP; including the corresponding STA in a scheduling candidate set for UL basic triggering when the selected average duration is less than a value; and A basic trigger frame is transmitted to trigger the corresponding STA to transmit UL QoS information upon exiting the power saving mode.

10. The method of claim 8, wherein the estimated power saving schedule of the corresponding STA indicates whether the corresponding STA is to transmit its UL data queue size to the AP when exiting the power saving mode, the method further comprising: an average duration between a first time when the corresponding STA selects the corresponding STA to exit the power saving mode and a second time when the corresponding STA transmits its UL data queue size to the AP; as well as A BSR trigger frame is transmitted when the selected average duration is greater than a value, triggering the corresponding STA to transmit buffer status information upon exiting the power saving mode.

11. The method of claim 1, wherein adjusting the one or more parameters comprises adjusting the one or more parameters based on a number of the STAs in the plurality of STAs whose duration is greater than the value satisfying a threshold number. 12 . The method of claim 11 , wherein the number of STAs is a percentage of STAs in the plurality of STAs whose duration is greater than the value.

13. A wireless communication device, comprising: interface, the interface being configured to: obtaining one or more indications that a wireless station (STA) is to enter a power save mode; and a processing system configured to: selecting, for each respective STA of a plurality of STAs, a duration between a first time at which the respective STA transmits or receives data and a second time at which the respective STA enters the power saving mode; as well as For each corresponding STA among the multiple STAs, one or more parameters of a multi-user (MU) channel access mechanism for transmitting uplink (UL) data are adjusted, wherein the one or more parameters are based on the duration between the first moment when the corresponding STA transmits or receives data and the second moment when the corresponding STA enters the power saving mode and based on the number of STAs among the multiple STAs for which the duration is greater than a value.

14. The wireless communication device of claim 13, wherein at least one of the one or more indications comprises a power management (PM) bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 1.

15. The wireless communication device of claim 14, wherein the MAC frame is a Quality of Service (QoS) NULL frame.

16. The wireless communication device of claim 13, wherein at least one of the one or more indications comprises a PM bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 0, and wherein the interface is further configured to: A buffer status report (BSR) trigger frame is outputted to trigger the corresponding STA to transmit buffer status information upon exiting the power saving mode.

17. The wireless communication device of claim 13, wherein the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between transmissions of trigger frames to the corresponding STA.

18. The wireless communication device of claim 17, wherein adjusting the one or more parameters comprises: At least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is decreased.

19. The wireless communication device of claim 13, wherein the processing system is further configured to: An average frequency at which the respective STA queues UL data for transmission to the wireless communication device is selected, wherein adjusting the one or more parameters is further based on the selected average frequency.

20. The wireless communication device of claim 13, wherein the processing system is further configured to: A power saving schedule for each respective STA of the plurality of STAs is estimated based at least in part on the one or more indications, wherein adjusting the one or more parameters is further based on the estimated power saving schedules for the plurality of STAs.

21. The wireless communication device of claim 20, wherein the estimated power save schedule of the corresponding STA indicates whether the corresponding STA is to transmit its UL data queue size to the wireless communication device when exiting the power save mode, wherein the processing system is further configured to: an average duration between a first time when the respective STA is selected to exit the power saving mode and a second time when the respective STA transmits its UL data queue size to the wireless communication device; including the corresponding STA in a scheduling candidate set for UL basic triggering when the selected average duration is less than a value; and wherein the interface is further configured to: A basic trigger frame is outputted to trigger the corresponding STA to transmit UL QoS information upon exiting the power saving mode.

22. The wireless communication device of claim 20, wherein the estimated power save schedule of the corresponding STA indicates whether the corresponding STA is to transmit its UL data queue size to the wireless communication device when exiting the power save mode, wherein the processing system is further configured to: an average duration between a first time when the respective STA is selected to exit the power saving mode and a second time when the respective STA transmits its UL data queue size to the wireless communication device; and wherein the interface is further configured to: A BSR trigger frame is outputted when the selected average duration is greater than a value, triggering the corresponding STA to transmit buffer status information upon exiting the power saving mode.

23. The wireless communication device of claim 13, wherein adjusting the one or more parameters comprises adjusting the one or more parameters based on a number of the STAs in the plurality of STAs for which the duration is greater than the value satisfying a threshold number.

24. The wireless communication device of claim 23, wherein the number of STAs is a percentage of STAs in the plurality of STAs whose duration is greater than the value.

25. A method for wireless communication performed by an apparatus of a wireless station (STA), comprising: transmitting one or more indications to a wireless access point (AP) that the STA will enter a power save mode; communicating data at each first time instant in a plurality of first time instants; entering a power saving mode at each second time in a plurality of second times; as well as A beacon is received from the AP indicating one or more parameters for transmitting uplink (UL) data for a multi-user (MU) channel access mechanism, the one or more parameters being based on a duration between a first moment at which a corresponding STA among a plurality of STAs transmits or receives data and a second moment at which the corresponding STA enters a power saving mode and based on the number of STAs among the plurality of STAs for which the duration is greater than a value.

26. The method of claim 25, wherein at least one of the one or more indications comprises a power management (PM) bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 1.

27. The method of claim 26, wherein the MAC frame is a Quality of Service (QoS) NULL frame.

28. The method of claim 25, wherein at least one of the one or more indications comprises a PM bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 0, the method further comprising: A buffer status report (BSR) trigger frame is received that triggers the STA to transmit buffer status information upon exiting the power saving mode.

29. The method of claim 25, wherein the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between transmissions of trigger frames to the STA.

30. The method of claim 29, wherein at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is set based on at least one of a likelihood that the STA has queued UL data, or an average frequency with which the STA queues UL data for transmission to the AP.

31. The method of claim 29, wherein at least one of the one or more parameters indicates a duration of the MU EDCA timer value, the method further comprising: An unsolicited BSR is transmitted to the AP based on the duration of the MU EDCA timer value exceeding a period of time, wherein the unsolicited BSR indicates buffer status information for at least one access category (AC) not affected by the MU EDCA timer value.

32. The method of claim 29, wherein at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is set based on an average duration between a first time when the STA exits the power saving mode and a second time when the STA transmits its UL data queue size to the AP, the method further comprising: receiving, when the average duration is less than a value, a basic trigger frame that triggers the STA to transmit UL QoS information to the AP upon exiting the power saving mode; as well as A buffer status report (BSR) trigger frame is received when the average duration is greater than the value, triggering the STA to transmit buffer status information to the AP upon exiting the power saving mode.

33. The method of claim 25, further comprising: A power save timer is incremented in response to receiving a trigger frame from the AP when the STA operates in a first power save mode and not receiving a trigger frame from the AP when the STA operates in a second power save mode.

34. A wireless communication device, comprising: interface, the interface being configured to: outputting one or more indications that the wireless communication device will enter a power save mode; and outputting or obtaining data at each first moment in time among a plurality of first moments in time; A processing system, the processing system being configured to: Entering the power saving mode at each second time in a plurality of second times; and The interface is further configured to: A beacon is obtained that indicates one or more parameters to be used for a multi-user (MU) channel access mechanism for transmitting uplink (UL) data, wherein the one or more parameters are based on a duration between a first moment at which a corresponding STA among a plurality of STAs transmits or receives data and a second moment at which the corresponding STA enters a power saving mode and based on the number of STAs among the plurality of STAs for which the duration is greater than a value.

35. The wireless communication device of claim 34, wherein at least one of the one or more indications comprises a power management (PM) bit carried in a medium access control (MAC) frame, wherein the PM bit is set to 1.

36. The wireless communication device of claim 35, wherein the MAC frame is a Quality of Service (QoS) NULL frame.

37. The wireless communication device of claim 24, wherein at least one of the one or more indications comprises a PM bit carried in a media access control (MAC) frame, wherein the PM bit is set to zero, and wherein the interface is further configured to: A buffer status report (BSR) trigger frame is obtained that triggers the wireless communication device to transmit buffer status information upon exiting the power save mode.

38. A wireless communication device as described in claim 34, wherein the one or more parameters include at least one of a MU enhanced distributed channel access (EDCA) timer value, an arbitration inter-frame space number (AIFSN), a minimum contention window (CW) size, a maximum CW size, or a time interval between each trigger frame transmission to the wireless communication device.

39. The wireless communication device of claim 38, wherein at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is set based on at least one of a likelihood that the wireless communication device has queued UL data, or an average frequency with which the wireless communication device queues UL data for transmission to a wireless access point (AP).

40. The wireless communication device of claim 38, wherein at least one of the one or more parameters indicates a duration of the MU EDCA timer value, wherein the interface is further configured to: An unsolicited BSR is output to a wireless access point (AP) based on the duration of the MU EDCA timer value exceeding a period of time, wherein the unsolicited BSR indicates buffer status information for at least one access category (AC) not affected by the MU EDCA timer value.

41. The wireless communication device of claim 38, wherein at least one of the MU EDCA timer value, the AIFSN, the minimum CW size, or the time interval is set based on an average duration between a first time the wireless communication device exits the power save mode and a second time the wireless communication device transmits its UL data queue size to a wireless access point (AP), wherein the interface is further configured to: obtaining a basic trigger frame for triggering the wireless communication device to transmit UL QoS information to the AP upon exiting the power saving mode when the average duration is less than a value; and A buffer status report (BSR) trigger frame is obtained that triggers the wireless communication device to transmit buffer status information to the AP upon exiting the power save mode when the average duration is greater than the value.

42. The wireless communication device of claim 34, wherein the processing system is further configured to: A power save timer is incremented in response to receiving a trigger frame from a wireless access point (AP) when the wireless communication device operates in a first power save mode and not receiving a trigger frame from the AP when the wireless communication device operates in a second power save mode.

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