WO2022013845A1

WO2022013845A1 - Method and devices for ofdma scheduling in wireless networks

Info

Publication number: WO2022013845A1
Application number: PCT/IB2021/056522
Authority: WO
Inventors: Mehmet Sukru KURAN; Omer I. TOPAL
Original assignee: Airties Kablosuz Iletisim Sanayi Ve Dis Ticaret A.S.
Priority date: 2020-07-17
Filing date: 2021-07-19
Publication date: 2022-01-20
Also published as: EP4183207A1

Abstract

Systems, devices, and methods for a throughput maximizing OFDMA scheduler for IEEE 802.11 networks is described herein. A scheduler may aim at maximizing the overall network throughput by considering channel bandwidth, modulation and coding scheme (MCS) levels of stations (STAs), and traffic loads of STAs. The scheduler may increase the overall network throughput and/or decrease the last-mile delay of traffics with high MCS levels.

Description

METHOD AND DEVICES FOR OFDMA SCHEDULING IN WIRELESS NETWORKS

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 63/053,219, filed July 17, 2020, which is incorporated by reference as if fully set forth.

BACKGROUND

[0002] Wireless devices, such as stations (STAs) or access points (APs) may employ one or more wireless (“Wi-Fi”) chips to access the Internet through a Wireless Local Area Network (WLAN). Although the number of devices using Wi-Fi is increasing at an exponential rate, the available bandwidth allocated for Wi-Fi communication has not increased at the same rate. In an effort to keep up with the increasing demand for throughput due to the limited bandwidth, new and updated approaches are needed in order to make wireless systems more efficient.

SUMMARY

[0003] Systems and methods for a throughput maximizing OFDMA scheduler for IEEE

802.11 networks is described. A scheduler may aim at maximizing the overall network throughput by considering channel bandwidth, modulation and coding scheme (MCS) levels of stations (STAs), and traffic loads of STAs. The scheduler may increase the overall network throughput and/or decrease the last-mile delay of traffics with high MCS levels.

BRIEF DESCRIPTION OF THE FIGURES

[0004] FIG. 1 is an example communication device.

[0005] FIG. 2 is a diagram illustrating an example of a RU configuration tree for 20 MHz.

[0006] FIG. 3A is an example set of equations used with one or more embodiments disclosed herein.

[0007] FIG. 3B is an example set of equations used with one or more embodiments disclosed herein.

[0008] FIG. 4 is an example table with data transmission rates.

[0009] FIG. 5 is an example table with simulation parameters.

[0010] FIG. 6 is a graph illustrating an example of total throughput under TCP traffic considering OFDMA MaxT scheduler and DCF/EDCA of one or more embodiments disclosed herein. [0011] FIG. 7 is a graph illustrating an example of total throughput under UDP traffic based on the OFDMA MaxT scheduler and DCF/EDCA of one or more embodiments disclosed herein. [0012] FIG. 8A is a graph that illustrates an example of average per STA delay with TCP traffic based on the OFDMA MaxT scheduler and DCF/EDCA of one or more embodiments disclosed herein.

[0013] FIG. 8B is a graph that illustrates an example of average per STA delay with TCP traffic based on the OFDMA MaxT scheduler and DCF/EDCA of one or more embodiments disclosed herein.

[0014] FIG. 9 is a flow chart of an example method according to one or more embodiments disclosed herein.

DETAILED DESCRIPTION

[0015] In an example communication system, there may be one or more wireless communication devices (e.g., 100 Communication Device of FIG. 1), such as stations (STAs) (e.g., client) or access points (APs), that utilize one or more wireless (“Wi-Fi”) chips to access the Internet through a Wireless Local Area Network (WLAN). FIG. 1 shows an example of a communication device (e.g., 100). The communication device may include a processor (e.g., 101), a transmit/receive element (e.g., transceiver 102, receiver, transmitter, etc.), means of user input/output (e.g., 104/105; a speaker/microphone, camera, a display/touchpad/keypad, etc.), non-removable memory, removable memory, a power source, a global positioning system (GPS) chipset, and/or other peripherals, among others. It should be noted that the STA and the AP described herein may include any sub-combination of the disclosed elements while remaining consistent with the description.

[0016] The processor may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the communication device 100 to operate in a wireless environment. The processor may be coupled to the transceiver, which may be coupled to the transmit/receive element. The processor and the transceiver may be separate components, or the processor and the transceiver may be integrated together in an electronic package or chip.

[0017] The transmit/receive element (e.g., transceiver) may be configured to transmit signals to, or receive signals from, other communication devices over an air interface. In an example, the transmit/receive element may be one or more antennas configured to transmit and/or receive radio frequency (RF) signals. [0018] The transmit/receive element may be a single physical element, or multiple physical elements. More specifically, a communication device may employ multiple-input multiple-output (MIMO) technology. In an example, a communication device may include two or more transmit/receive elements (e.g., multiple antennas) for transmitting and receiving wireless signals over an air interface. [0019] A processor may be configured to modulate the signals that are to be transmitted by the transmit/receive element and to demodulate the signals that are received by the transmit/receive element. The communication device may have multi-mode capabilities. Thus, the communications device may include multiple transmit/receive elements and/or multiple processors to communicate via multiple air interfaces.

[0020] The processor of the communication device may be coupled to, and may receive user input data from, the speaker/microphone, the keypad, and/or the display/touchpad (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor may also output user data to the speaker/microphone, the keypad, and/or the display/touchpad. In addition, the processor may access information from, and store data in, any type of suitable memory, such as the non-removable memory and/or the removable memory. The non-removable memory may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In some cases, the processor may access information from, and store data in, memory that is not physically located on the communication device, such as on a server or a home computer.

[0021] The processor may receive power from the power source and may be configured to distribute and/or control the power to the other components in the communication device. The power source may be any suitable device for powering the communication device. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0022] The processor may further be coupled to other peripherals, which may include one or more software and/or hardware modules that provide additional features, functionality and/or wired or wireless connectivity. For example, the peripherals may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and/or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and/or Augmented Reality (VR/AR) device, an activity tracker, and the like. The peripherals may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and/or a humidity sensor.

[0023] The communication device may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the uplink (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and/or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor. In an embodiment, the communication device may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes) for either the uplink (e.g., for transmission) or the downlink (e.g., for reception).

[0024] In an example communication system, a WLAN in Infrastructure Basic Service Set

(BSS) mode may have an AP for the BSS and one or more STAs associated with the AP. The AP may have access or an interface to a Distribution System (DS) or another type of wired/wireless network that carries traffic in to and/or out of the BSS. Traffic to STAs that originate from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs with destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and/or referred to as peer-to-peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an “ad-hoc” mode of communication. In some cases, there may be a plurality of APs configured in a mesh network as defined by IEEE 802.11.

[0025] A communication device (e.g., an AP or STA) may employ a throughput maximizing

OFDMA scheduler for IEEE 802.11 networks. In one scenario, the scheduler may operate in an AP. In another scenario, the scheduler may be implemented in a controller, which may reside in any device in the network and may control the APs in the network (e.g., by sending instructions to the APs). In one scenario, the scheduler may be implemented in a cloud device/system (e.g., external to the network). The scheduler may schedule traffic/STAs with the goal of maximizing the overall network throughput by considering one or more factors, such as channel bandwidth, modulation and coding scheme (MCS) levels of STAs, and traffic loads of STAs. The scheduler may increase the overall network throughput and/or decrease the last-mile delay of traffic with high MCS levels. In one scenario, the scheduler may be used in the multi-user MAC framework of the IEEE 802.11ax standard. [0026] The scheduler may work both in downlink and uplink directions and may assign resource units (e.g., a subdivision of a frequency channel, and/or a subdivision of a frequency bandwidth) to STAs using a linear programming technique that may consider one or more of: the load of each client, possible resource unit configurations (RUCs), modulation-coding scheme (MCS) of each client, and/or aging factor of each client’s load. The scheduler may increase the total throughput in a network and decrease the average end-to-end delay regardless of the number of stations connected to APs by prioritizing the traffic of clients connected via high modulation and coding schemes (MCSs).

[0027] There is an ever-increasing demand for higher throughput in Wi-Fi networks, which have been demonstrated in various IEEE 802.11 protocols. For example, IEEE 802.11h and IEEE 802.11ac, focused mainly on throughput-increasing mechanisms and pushed the network throughput over the gigabit barrier. This increase further pushed up the pervasiveness of Wi-Fi and resulted in many overlapping dense Wi-Fi networks with higher numbers of user devices (i.e., STA) per network. In such dense environments, a bottleneck metric may be the throughput density, as compared to or instead of the aggregate throughput.

[0028] In order to address this issue, IEEE 802.11 groups, such as the IEEE 802.11ax, may have goals of increasing the efficiency of network(s) in a given area. There may be key medium access control (MAC) layer mechanisms such as orthogonal frequency division multiple access (OFDMA) scheduled access via the multi-user MAC framework (MU-MAC), MU-MIMO, overlapping basic service set packet detect (OBSS-PD), and/or target wake timer (TWT).

[0029] Using OFDMA techniques, a channel may be divided into smaller parts called resource units (RUs), where each RU corresponds to a set of subcarriers of the available channel bandwidth. Using the MU-MAC framework and OFDMA, a scheduler may be able to schedule the access of STAs to these RUs at the same time over the same Wi-Fi channel. This approach is fundamentally different from the classical random-access method of Wi-Fi by practically giving the control of the medium access to the AP (e.g., a scheduler). Such a controlled access may mitigate the impact of common performance-limiting causes such as the bad apple scenario, where a single STA having a low modulation and coding scheme (MCS) level significantly diminishes the overall performance of the whole Wi-Fi network. With OFDMA scheduling and the MU-MAC determined/sent by an AP of the network, each STA within the same network is able to access the medium at the same time with other STAs in the network while using a different MCS level. [0030] The performance of the MU-MAC framework may depend on the AP knowing queue information regarding all its associated ST As. Although this information is readily available for the downlink (DL) traffic, in some Wi-Fi implementations, the AP may not have any mechanism to gather this information for the uplink (UL) traffic. To this end, there may be a buffer status report (BSR) mechanism that the AP may use to gather this information from the STAs. In case the AP does not know this information, there may also be the option of allocating some, or all, of these RUs as random- access RUs, which may be called the Uplink OFDMA Random Access (UORA) mechanism.

[0031] At its core, the MU-MAC framework may be responsible for allocating channel resources (e.g., frequency and time slots) to the AP and connected STAs while also being compliant to legacy random channel access mechanism of IEEE 802.11. In the frequency dimension, the channel may be divided into RUs, each of which may be allocated to different devices. In a time dimension, time may be divided into fixed slots called transmission opportunities (TXOP). At the MAC layer, the MU-MAC framework may use four different mechanisms for different use-cases: DL-MU access, UL-MU access, Cascading UL & DL-MU access, and/or UORA. While the first three mechanisms may be scheduled access mechanisms where the whole channel access is managed by the AP, in the fourth mechanism UORA, the RUs may be allocated to devices with a DCF/EDCA-like random access mechanism.

[0032] A scheduler may be used in the MU-MAC framework considering both the UL and the DL traffic. The scheduler may work repeatedly at the start of each OFDMA opportunity by utilizing an aging mechanism to provide some level of fairness and avoid starvation of STAs (e.g., STAs deprived of opportunities to transmit/receive) whose traffic loads are low compared to others. The scheduler may consider channel bandwidth, STA traffic queues, and STA MCS levels. The scheduler may involve an aging mechanism to be used within the scheduler so that in each subsequent run of the optimization, the scheduler may act by considering the allocations to each STA in the previous schedules.

[0033] The OFDM PHY layer may divide the wireless channel into 312.5 kHz subcarriers or tones. In order to allocate the subcarriers to devices in a more efficient manner and increase the spectral efficiency, IEEE 802.11ax may utilize subcarriers that are four times smaller than legacy sizes, each with a bandwidth of 78.125 kHz.

[0034] As discussed herein, these subcarriers may be bundled together to form RUs, each of which can be allocated to devices in an atomic manner (e.g., immediately, or with negligible measurable delay). The size of all possible RUs may be standardized, as well as how to divide a channel with a certain bandwidth into a set of RUs. In one example, there may be seven different RU sizes, such as 26-tone, 52-tone, 106-tone, 242-tone, 484-tone, 996-tone, and 2x996-tone. Considering these RU sizes, a 20 MHz channel may be divided in a variety of ways ranging between a single 242-tone RU to nine 26-tone RUs as depicted in the RU configuration tree shown in FIG. 2. Note that, each node of the tree can be divided into smaller parts (sets) independently. An RU configuration (RUC) comprises a selected set of RUs, such as a selected set of nodes of the tree, but if only a node is selected, all of its descendants cannot be selected in the same RUC. For example, for a channel bandwidth of 20 MHz, the set of (106, 26, 106) or the set of (106, 26, 52, 52) are possible RUCs.

[0035] An issue with the different RUCs is that the more RUs in an allocation, the smaller total number of data subcarriers can be used. Therefore, the selected RUC is critical for the performance of the network in addition to deciding on the RU size allocated to each device.

[0036] The scheduler may include the determined schedule information in an HE-SIG-B header of a frame (e.g., 802.11ax frame). In this header, the scheduler may declare the RUC to be used in the subsequent transmission as well as which RU may be allocated for the communication with which STA. Upon the reception of this HE-SIG-B header, the STAs learn which RU to listen to, if there is a transmission destined for them, or not to listen to any RUs at all. The scheduler may include the resource allocation information in a trigger frame of an 802.11ax uplink communication.

[0037] Due to the possible RUCs that are available, the resource allocation in OFDMA scheduling may be characterized as a three-dimensional problem (e.g., allocation of RUC, allocation of RUs, allocation of the time slots), or a four-dimensional problem when MU-MIMO is also considered. Furthermore, at any given TXOP, the transmission can either be in the DL or UL direction. Therefore, based on the characteristics of the network traffic, the scheduler/ AP may also decide on the direction of the MU access at any given time. Lastly, considering the fact that legacy STAs will not be able to utilize the OFDMA access, the AP may also allocate some TXOPs for classical random access in which legacy devices can send their frames as well as the AP sending them frames.

[0038] In one scenario, the scheduler may focus on maximizing the throughput of the Wi-Fi network while avoiding any starvation issues. The scheduler may run at the start of each TXOP and may calculate the ideal resource allocation considering the queue lengths and link qualities of each STA, in both DL and UL directions. The scheduler may work in DL mode or in UL mode or in both DL and UL modes.

[0039] FIG. 3A and 3B show a plurality of example equations that may be used and referred to herein with regard to one or more embodiments. Each equation is numbered (#).

[0040] In one scenario, the scheduler may solve an optimization problem, where the parameters and variables of the problem may be defined over the following sets: 1) 5 the set of STAs connected to the AP in the network; 2) R_bw, the set of available RUCs given the channel bandwidth (an example of this set considering 20 MHz channel bandwidth is as given in (2)); 3) I_bw, the index set for RUCs in R_bw 4) iRUCk- the index set for RUs in RUCk. (p(k,j) gives the unique index of each possible RU within each possible RUC given a channel bandwidth. It is a map from the index of a RUC (k, Vk e Ibw) and the index of an RU within that RUC (j, Vj e iRUCk ) to a set of integer numbers between 1 and mmaxforthe given channel bandwidth, following the function in Eq.1. Please note that = (k, j) is its inverse function.

[0041] Three parameters are defined over the set S: the modulation and coding rate of each

STA (MCSi, Vi e S), queue length of each STA (Li, Vi e S), and the aging factor of each STA (Ai, Vi e S). RUVj,k is defined as the value (i.e., number of subcarriers) of the

RU of RUCk. Finally,

Tr_MCSi,_Ruv_{j k} is defined as the data transmission rate of the STA given its MCS level, MCSi, and

RU of RUCk. An example of these transmission rates considering 20 MHz channel bandwidth, one spatial stream, and 3.2ps guard interval are as given in FIG. 4 (Table I).

[0042] There are three variables in the optimization problem: Tk, binary variables whose value is 1 if RUCk is selected, and 0 otherwise; ¾·,_¾, binary variables whose value is 1 if STA i is allocated the

RU of RUCk , 0 otherwise; lastly Y_{i j k} , refers to the allocated transmission rate of the i^th STA at the j^th RU of RUCk in bits.

[0043] Considering these parameters and variables, the problem may be solved (e.g., achieving the goal throughput-maximizing), by giving as much allocated transmission rate as possible to all ST As while adhering to the STA-to-RU, RU-to-STA, RU limit, RU configuration, queue length, and MCS level constraints. The first four constraints reflect the RU allocation rules and limitations of the IEEE 802.11 ax OFDMA scheduling. The STA-to-RU constraint Eq. (4) states that in an OFDMA schedule, a given STA may only be allocated a single RU. In the other direction, the RU-to-STA constraint Eq. (5) states that a given RU may only be allocated to a single STA. Given an RU configuration, the number of RUs allocated to different STAs cannot exceed the RU count of the selected RUC, or in other words cannot exceed the cardinality of the selected item of R_bw (Eq. 6). Lastly, only a single RUC can be selected at any given time (Eq. 7).

[0044] The last two constraints deal with limitations over the allocated transmission rate.

Queue length constraint Eq. (8) states that each STA may not be allocated a transmission rate more than its queue length, whether it is allocated this RU or not. The MCS level constraint on the other hand Eq. (9) states that the allocated transmission rate may not exceed the transmission rate of the RU given the MCS level of the STA for a specific Wi-Fi TXOP duration {d_TX0P). For example, even if a STA has many frames at its queue, if the link between itself and the AP has very low RSSI values, the STA will have much lower maximum allocated transmission rate than the STAs whose link to the AP is higher.

[0045] The OFDMA resource allocation performed by the scheduler may be active for only the next TXOP duration. In one scenario, the scheduler may work in rounds, such as once at the start of each TXOP.

[0046] Since the optimization problem is trying to maximize the total amount of data that has been transmitted, the STAs whose MCS levels or Li[t] values are low may be at a disadvantage therefore they may be given RUs last, if available. Although this behavior may increase the airtime efficiency of the network, if left unchecked, it may lead to starvation of the traffics of STAs with low MCS values. In order to avoid this behavior, at the end of each optimization round, the aging values of each STA, A, may be recalculated based on the previous Yy_,/< values and current Li values. For a given STA /, if there are unsent frames in the queue of the STA (i.e., Li[t] > 0) then Eq. (10) may be evaluated, where MI is the maximum aging value for a given STA.

[0047] On the other hand, if there are no leftover frames in the queue (i.e., Li[t] = 0), then

Eq. (11) may be evaluated. Note that, this aging mechanism may be disabled by setting the base aging value to 1 (i.e., AF = 1).

[0048] For demonstration purposes, the performance of the scheduler may be evaluated via computer simulations. The parameters used in the computer simulations are given in FIG. 5 (Table II). [0049] FIG. 6 is a graph illustrating an example of total throughput under TCP traffic considering OFDMA MaxT scheduler and DCF/EDCA of one or more embodiments disclosed herein. FIG. 7 is a graph illustrating an example of total throughput under UDP traffic based on the OFDMA MaxT scheduler and DCF/EDCA of one or more embodiments disclosed herein. As seen in both FIG. 6 and FIG. 7, in all scenarios the scheduler outperforms the standard DCF/EDCA mechanism.

[0050] The scheduler may prioritize the STAs with high MCS levels over the STAs with low

MCS levels. This is due to the fact that STAs with high MCS levels utilize the air medium much more efficiently in terms of throughput.

[0051] FIG. 8A is a graph that illustrates an example of average per STA delay with TCP traffic in DL direction based on the OFDMA MaxT scheduler and DCF/EDCA of one or more embodiments disclosed herein. FIG. 8B is a graph that illustrates an example of average per STA delay with TCP traffic in the UL direction based on the OFDMA MaxT scheduler and DCF/EDCA of one or more embodiments disclosed herein. While increasing the total network throughput, as shown in FIG. 8A and 8B, the scheduler may also significantly decrease the Wi-Fi delay of the STAs with high MCS values while increasing it for the STAs with low MCS values. [0052] FIG. 9 is a flow chart of an example method according to one or more embodiments disclosed herein. In method 900, there may be orthogonal frequency division multiple access (OFDMA) scheduled access via the multi-user MAC framework (MU-MAC) implemented by a scheduler operating on a device (e.g., an access point (AP) of a wireless network, a controller, etc.). The method may comprise of: 901 receiving queue information from a plurality of stations (STAs); 902, determining scheduling information based on scheduling one or more STAs of the plurality of STAs using one or more modulation and coding schemes (MCS) based on the queue information; and 903, sending the scheduling information to one or more STAs of the plurality of STAs. The scheduling information may instruct the STAs to use specific RUs in a way that optimizes the performance of the network and/or the STAs. The queue information may be received via a buffer status report or uplink OFDMA random access information. The scheduling information may be sent in an HE-SIG-B field. The scheduling information may include downlink scheduling, uplink scheduling, or both downlink and uplink scheduling. The scheduling information may include resource unit configuration information, time slots, and resource units. The determining the scheduling information may be based on maximizing a throughput metric of the wireless network. The determining the scheduling information may include solving an optimization problem. The one or more STAs of the plurality of STAs may include a first STA and a second STA, and the scheduling information for the first STA uses a first MCS and the second STA uses a second MCS, wherein the first MCS is different than the second MCS.

[0053] In one scenario, the scheduler may be a hybrid scheduler that has different utility functions based on the quality-of-service levels of each traffic. In one scenario, the scheduler may cover transmissions where the transmission direction dynamically changes. In one scenario, the scheduler may utilize the cascading UL/DL MU access.

Claims

CLAIMS What is claimed is:

1. A method for orthogonal frequency division multiple access (OFDMA) scheduled access via a multi-user MAC framework (MU-MAC) implemented by an access point (AP) of a wireless network, the method comprising: receiving queue information from a plurality of stations (STAs); determining scheduling information based on scheduling one or more STAs of the plurality of STAs using one or more modulation and coding schemes (MCS) based on the queue information; and sending the scheduling information to one or more STAs of the plurality of STAs.

2. A method as in any one of the preceding claims, wherein the queue information is received via a buffer status report or uplink OFDMA random access information.

3. A method as in any one of the preceding claims, wherein the scheduling information is sent in an HE-SIG-B field.

4. A method as in any one of the preceding claims, wherein the scheduling information includes downlink scheduling, uplink scheduling, or both downlink and uplink scheduling.

5. A method as in any one of the preceding claims, wherein the scheduling information includes resource unit configuration information, time slots, and resource units.

6. A method as in any one of the preceding claims, wherein determining the scheduling information is based on maximizing a throughput metric of the wireless network.

7. A method as in any one of the preceding claims, wherein determining the scheduling information includes solving an optimization problem.

8. A method as in any one of the preceding claims, wherein the one or more STAs of the plurality of STAs include a first STA and a second STA, and the scheduling information for the first STA uses a first MCS and the second STA uses a second MCS, wherein the first MCS is different than the second MCS.

9. At least one processor operatively connected to transceiver, the processor and transceiver configured to perform at least part of any one of the methods of claims 1 -8.

10. A network element configured to perform at least part of any one of the methods of claims 1 -8.

11. A base station configured to perform at least part of any one of the methods of claims 1-8.

12. An access point (AP) configured to perform at least part of any one of the methods of claims 1-8.

13. A station (STA) configured to perform at least part of any one of the methods of claims 1-8.

14. An integrated circuit configured to perform at least part of any one of the methods of claims 1-8.

15. A memory configured to store instructions, and a processor operatively coupled to the memory configured to execute the instructions to perform at least part of any one of the methods of claims 1-8.