WO2018151751A1

WO2018151751A1 - Block acknowledgment for multi-user multiple input multiple output

Info

Publication number: WO2018151751A1
Application number: PCT/US2017/039796
Authority: WO
Inventors: Ou Yang; Chittabrata GHOSH; Carlos Cordeiro; Solomon Trainin; Laurent Cariou
Original assignee: Intel IP Corporation
Priority date: 2017-02-17
Filing date: 2017-06-28
Publication date: 2018-08-23

Abstract

This disclosure describes systems, methods, and devices related to block acknowledgment for MU-MIMO. A device may determine a first multiuser frame comprised of one or more subframes to be sent to one or more devices in a multiuser multiple input and multiple output (MU MIMO) group. The device may cause to set a first acknowledgement policy field in a first subframe of the first multiuser frame. The device may cause to send the first MU frame to the one or more devices. The device may identify a first block acknowledgement frame received from a first device of the one or more devices.

Description

BLOCK ACKNOWLEDGMENT FOR MULTI-USER MULTIPLE INPUT MULTIPLE

OUTPUT

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 62/460,337 filed February 17, 2017, the disclosure of which is incorporated herein by reference as if set forth in full.

TECHNICAL FIELD

[0002] This disclosure generally relates to systems and methods for wireless communications and, more particularly, to block acknowledgment for multi-user multiple input multiple output (MU-MIMO) communication.

BACKGROUND

[0003] Wireless devices are becoming widely prevalent and are increasingly requesting access to wireless channels. The growing density of wireless deployments require increased network and spectrum availability. Wireless devices may communicate with each other using directional transmission techniques, including but not limited to beamforming techniques. Wireless devices may communicate over a next generation 60 GHz (NG60) network, an enhanced directional multi-gigabit (EDMG) network, and/or any other network.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 depicts a network diagram illustrating an example network environment for block acknowledgment for MU-MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0005] FIG. 2 depicts an illustrative schematic diagram for block acknowledgment for MU- MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0006] FIG. 3 depicts an illustrative schematic diagram for block acknowledgment for MU- MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0007] FIG. 4 depicts an illustrative schematic diagram for block acknowledgment for MU- MIMO communication, in accordance with one or more example embodiments of the present disclosure. [0008] FIG. 5 depicts an illustrative schematic diagram for block acknowledgment for MU- MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0009] FIG. 6 depicts an illustrative schematic diagram for block acknowledgment for MU- MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0010] FIG. 7A depicts a flow diagram of an illustrative process for block acknowledgment for MU-MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0011] FIG. 7B depicts a flow diagram of an illustrative process for block acknowledgment for MU-MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0012] FIG. 8 depicts a functional diagram of an example communication station that may be suitable for use as a user device, in accordance with one or more example embodiments of the present disclosure.

[0013] FIG. 9 depicts a block diagram of an example machine upon which any of one or more techniques (e.g., methods) may be performed, in accordance with one or more example embodiments of the present disclosure.

DETAILED DESCRIPTION

[0014] Example embodiments described herein provide certain systems, methods, and devices for block acknowledgment for MU-MIMO communication. The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0015] Devices may communicate over a next generation 60 GHz (NG60) network, an enhanced directional multi-gigabit (EDMG) network, and/or any other network. Devices operating "in EDMG" may be referred to herein as EDMG devices. This may include user devices, and/or APs or other devices capable of communicating in accordance to a communication standard, including but not limited to IEEE 802. Had and/or IEEE 802. Hay. However, IEEE 802. Had does not support downlink MU-MIMO.

[0016] Generally, instead of transmitting an individual acknowledgement (ACK) for every media access control protocol data unit (MPDU), multiple MPDUs can be acknowledged together using a single block acknowledgment (BACK) frame. IEEE 802. Hay needs to support a BACK for MU-MIMO.

[0017] Considering the higher data rate that IEEE 802. Hay is targeting (e.g., greater than 20Gbps), the efficiency of MU-MIMO BACK becomes a concern, especially when the number of station devices (STAs) in a MU-MIMO group is large, and the multiuser physical layer convergence protocol data unit (PPDU) size is small.

[0018] Example embodiments of the present disclosure relate to systems, methods, and devices for block acknowledgment for MU-MIMO communication.

[0019] A directional multi-gigabyte (DMG) communications may involve one or more directional links to communicate at a rate of multiple gigabits per second, for example, at least 1 gigabit per second, 7 gigabits per second, or any other rate. An amendment to a DMG operation in a 60 GHz band, e.g., according to an IEEE 802. Had standard, may be defined, for example, by an IEEE 802.1 lay project.

[0020] In some demonstrative embodiments, one or more devices may be configured to communicate over a next generation 60 GHz (NG60) network, an enhanced DMG (EDMG) network, and/or any other network. For example, the one or more devices may be configured to communicate over the NG60 or EDMG networks.

[0021] In one embodiment, a block acknowledgment for MU-MIMO communication system may facilitate that one STA in a MU-MIMO group may be designated to immediately send a block acknowledgment after a channel delay time has passed from receiving an MU PPDU from an access point (AP) or a personal basic service set (PBSS) control point (PCP). Subsequent to the AP (or PCP) receiving the block acknowledgment from this STA, the AP may send a block acknowledgment request to another STA of the MU-MIMO group, whose block acknowledgment has not been received by the AP. This may solicit the STA to send its block acknowledgment to the AP. If there are additional STAs in the MU-MIMO group, the AP may then send another block acknowledgment request to one of the STAs whose block acknowledgment has not been collected. [0022] In one embodiment, a block acknowledgment for MU-MIMO communication system may facilitate that one or more MU-MIMO STAs may acknowledge the receipt of an MU PPDU from an AP or PCP by sending a block acknowledgment (BACK) to the AP/PCP sequentially. Additionally, and/or alternatively, the order of the acknowledgments from the STAs may be indicated in an MU block acknowledgment request (BAR) frame that may be sent by the AP/PCP. This option may save bandwidth to transmit multiple block acknowledgment request (BAR) per MU PPDU and hence has high bandwidth efficiency. However, this option may cause synchronization problem among MU-MIMO STAs when BACKs are sent sequentially, and in case some BACKs are missing, a 3rd party STA may sense the channel clear for longer than a channel access delay (e.g., distributed interframe space (DIFS)) and hence try to access the channel.

[0023] In another embodiment, a block acknowledgment for MU-MIMO communication system may facilitate that an AP/PCP may trigger the receipt of one or more BACKs from one or more STAs based at least in part on setting an acknowledgment policy bit(s). For example, an AP/PCP may send an MU PPDU to a group of MU-MIMO STAs. In the MU PPDU, the AP/PCP may set the ACK policy to 0 0 to only one of the MU-MIMO STAs, and set the ACK policy to 1 1 to the rest of the STAs in the MU-MIMO group. The STA that receives the MU PPDU with ACK Policy 0 0 may respond AP/PCP with BACK after a short inter-frame space (SIFS) time. The STAs that receive the MU PPDU with ACK Policy 1 1 may record the state and may not respond with a BACK. The AP/PCP may receive the BACK from one STA, and continue sending the next MU PPDU to the group of MU-MIMO STAs. In the MU PPDU, the AP/PCP may set the ACK policy to 0 0 for another STA in the MU-MIMO group, and set the ACK policy to 1 1 to the rest of the STAs in the MU-MIMO group. In fact, the AP/PCP may collect BACK from only one STA after sending each MU PPDU, and the AP/PCP may collect BACK from STAs in a round-robin fashion. This option may save bandwidth to transmit multiple BAR per MU PPDU and hence has high bandwidth efficiency. It also ensures the channel is occupied by the AP/PCP for no longer than distributed coordination function IFS (DIFS) clearance. Considering that the current BACK size is about 1024 bytes of bitmap, some of these bits in the bitmap may not be utilized. Sending one BACK for multiple MU PPDUs may better utilize the bitmap in a BACK and may reduce overhead. [0024] The above descriptions are for purposes of illustration and are not meant to be limiting. Numerous other examples, configurations, processes, etc., may exist, some of which are described in greater detail below. Example embodiments will now be described with reference to the accompanying figures.

[0025] FIG. 1 is a network diagram illustrating an example network environment, in accordance with one or more example embodiments of the present disclosure. Wireless network 100 may include one or more user device(s) 120 and one or more access point(s) (AP) 102 or (PCP), which may communicate in accordance with IEEE 802.11 communication standards, such as the IEEE 802.11 ad and/or IEEE 802.11 ay specifications. The user device(s) 120 may be referred to as stations (STAs). The user device(s) 120 may be mobile devices that are non- stationary and do not have fixed locations. Although the AP 102 is shown to be communicating on multiple antennas with user devices 120, it should be understood that this is only for illustrative purposes and that any user device 120 may also communicate using multiple antennas with other user devices 120 and/or AP 102.

[0026] In some embodiments, the user devices 120 and AP 102 may include one or more computer systems similar to that of the functional diagram of FIG. 8 and/or the example machine/system of FIG. 9.

[0027] One or more illustrative user device(s) 120 and/or AP 102 may be operable by one or more user(s) 110. In some embodiments, one or more illustrative user device(s) 120 and/or AP 102 may operate as a personal basic service set (PBSS) control point/access point (PCP/AP). The user device(s) 120 (e.g., 124, 126, or 128) and/or AP 102 may include any suitable processor- driven device including, but not limited to, a mobile device or a non-mobile, e.g., a static, device. For example, user device(s) 120 and/or AP 102 may include, a user equipment (UE), a station (STA), an access point (AP), a personal computer (PC), a wearable wireless device (e.g., bracelet, watch, glasses, ring, etc.), a desktop computer, a mobile computer, a laptop computer, an ultrabook^tm computer, a notebook computer, a tablet computer, a server computer, a handheld computer, a handheld device, an internet of things (IoT) device, a sensor device, a PDA device, a handheld PDA device, an on-board device, an off-board device, a hybrid device (e.g., combining cellular phone functionalities with PDA device functionalities), a consumer device, a vehicular device, a non-vehicular device, a mobile or portable device, a non-mobile or non-portable device, a mobile phone, a cellular telephone, a PCS device, a PDA device which incorporates a wireless communication device, a mobile or portable GPS device, a DVB device, a relatively small computing device, a non-desktop computer, a "carry small live large" (CSLL) device, an ultra mobile device (UMD), an ultra mobile PC (UMPC), a mobile internet device (MID), an "origami" device or computing device, a device that supports dynamically composable computing (DCC), a context-aware device, a video device, an audio device, an A/V device, a set- top-box (STB), a blu-ray disc (BD) player, a BD recorder, a digital video disc (DVD) player, a high definition (HD) DVD player, a DVD recorder, a HD DVD recorder, a personal video recorder (PVR), a broadcast HD receiver, a video source, an audio source, a video sink, an audio sink, a stereo tuner, a broadcast radio receiver, a flat panel display, a personal media player (PMP), a digital video camera (DVC), a digital audio player, a speaker, an audio receiver, an audio amplifier, a gaming device, a data source, a data sink, a digital still camera (DSC), a media player, a smartphone, a television, a music player, or the like. It is understood that the above is a list of devices. However, other devices, including smart devices such as lamps, climate control, car components, household components, appliances, etc. may also be included in this list.

[0028] Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to communicate with each other via one or more communications networks 130 and/or 135 wirelessly or wired. Any of the communications networks 130 and/or 135 may include, but not limited to, any one of a combination of different types of suitable communications networks such as, for example, broadcasting networks, cable networks, public networks (e.g., the Internet), private networks, wireless networks, cellular networks, or any other suitable private and/or public networks. Further, any of the communications networks 130 and/or 135 may have any suitable communication range associated therewith and may include, for example, global networks (e.g., the Internet), metropolitan area networks (MANs), wide area networks (WANs), local area networks (LANs), or personal area networks (PANs). In addition, any of the communications networks 130 and/or 135 may include any type of medium over which network traffic may be carried including, but not limited to, coaxial cable, twisted-pair wire, optical fiber, a hybrid fiber coaxial (HFC) medium, microwave terrestrial transceivers, radio frequency communication mediums, white space communication mediums, ultra-high frequency communication mediums, satellite communication mediums, or any combination thereof. [0029] Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may include one or more communications antennas. The one or more communications antennas may be any suitable type of antennas corresponding to the communications protocols used by the user device(s) 120 (e.g., user devices 124, 126 and 128), and AP 102. Some non-limiting examples of suitable communications antennas include Wi-Fi antennas, Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards compatible antennas, directional antennas, non- directional antennas, dipole antennas, folded dipole antennas, patch antennas, multiple-input multiple-output (MEVIO) antennas, omnidirectional antennas, quasi-omnidirectional antennas, or the like. The one or more communications antennas may be communicatively coupled to a radio component to transmit and/or receive signals, such as communications signals to and/or from the user devices 120 and/or AP 102.

[0030] Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform directional transmission and/or directional reception in conjunction with wirelessly communicating in a wireless network. Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform such directional transmission and/or reception using a set of multiple antenna arrays (e.g., DMG antenna arrays or the like). Each of the multiple antenna arrays may be used for transmission and/or reception in a particular respective direction or range of directions. Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform any given directional transmission towards one or more defined transmit sectors. Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform any given directional reception from one or more defined receive sectors.

[0031] MEVIO beamforming in a wireless network may be accomplished using RF beamforming and/or digital beamforming. In some embodiments, in performing a given MIMO transmission, user devices 120 and/or AP 102 may be configured to use all or a subset of its one or more communications antennas to perform MIMO beamforming.

[0032] Any of the user devices 120 (e.g., user devices 124, 126, 128), and AP 102 may include any suitable radio and/or transceiver for transmitting and/or receiving radio frequency (RF) signals in the bandwidth and/or channels corresponding to the communications protocols utilized by any of the user device(s) 120 and AP 102 to communicate with each other. The radio components may include hardware and/or software to modulate and/or demodulate communications signals according to pre-established transmission protocols. The radio components may further have hardware and/or software instructions to communicate via one or more Wi-Fi and/or Wi-Fi direct protocols, as standardized by the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards. In certain example embodiments, the radio component, in cooperation with the communications antennas, may be configured to communicate via 2.4 GHz channels (e.g., 802.11b, 802. l lg, 802.11η, 802.1 lax), 5 GHz channels (e.g., 802.11η, 802.1 lac, 802.1 lax), or 60 GHZ channels (e.g., 802.1 lad). In some embodiments, non- Wi-Fi protocols may be used for communications between devices, such as Bluetooth, dedicated short-range communication (DSRC), Ultra-High Frequency (UHF) (e.g., IEEE 802.1 laf, IEEE 802.22), white band frequency (e.g., white spaces), or other packetized radio communications. The radio component may include any known receiver and baseband suitable for communicating via the communications protocols. The radio component may further include a low noise amplifier (LNA), additional signal amplifiers, an analog-to-digital (A/D) converter, one or more buffers, and digital baseband.

[0033] Some demonstrative embodiments may be used in conjunction with a wireless communication network communicating over a frequency band of 60 GHz. However, other embodiments may be implemented utilizing any other suitable wireless communication frequency bands, for example, an extremely high frequency (EHF) band (the millimeter wave (mmWave) frequency band), a frequency band within the frequency band of between 20 GHz and 300 GHz, a WLAN frequency band, a WPAN frequency band, a frequency band according to the WGA specification, and the like.

[0034] The phrases "directional multi-gigabit (DMG)" and "directional band (DBand)," as used herein, may relate to a frequency band wherein the channel starting frequency is above 45 GHz. In one example, DMG communications may involve one or more directional links to communicate at a rate of multiple gigabits per second, for example, at least 1 gigabit per second, 7 gigabits per second, or any other rate.

[0035] Media access control protocol data unit (MPDU) is a message (protocol data unit) exchanged between media access control (MAC) entities in a communication system based on the layered Open Systems Interconnection model. In systems where the MPDU may be larger than the MAC service data unit (MSDU), the MPDU may include multiple MSDUs as a result of packet aggregation. In systems where the MPDU is smaller than the MSDU, then one MSDU may generate multiple MPDUs as a result of packet segmentation.

[0036] An AMPDU is an aggregation of one or more MPDUs, which are information that is delivered as a unit among entities in a network and that may contain control information, such as address information, or user data. One purpose for using an aggregated MPDU is to allow multiple MPDUs to be sent to the same receiving device concatenated in a single MPDU (e.g., AMPDU). A physical layer convergence protocol (PLCP) data unit (PPDU) to be transmitted to multiple stations may be designated as MU PPDU and may be composed of one or more MPDUs or one or more AMPDUs. The MU PPDU may include a PHY preamble in order to be a message at the PHY layer between peer entities in a communication system. The PHY preamble may be a common PHY preamble designated for all the packets within the MU PPDU (e.g., MPDUs or AMPDUs). For example, if the AP has a plurality of antennas, a first antenna may send a first AMPDU of the MU PPDU to a first STA, the second antenna may send a second AMPDU of the MU PPDU to a second STA, and so forth. This mechanism is also similar for sending MPDUs to one or more STAs. When each of the STAs receive the MU PPDU, it decodes the PHY preamble, determine which MPDU or AMPDU is destined for it. In essence, an MU PPDU is a single frame with multiple frames transmitted to different STAs using multiple spatial streams.

[0037] MU BAR may be made up of multiple BAR frames having a common preamble. Each BAR frame may be composed of one or more fields. For example, one of the fields may be a BAR control field. The BAR control field may contain, multiple fields, for example, a BAR acknowledgment (ACK) policy field, a reserved field, and other fields.

[0038] A quality of service (QoS) control field may be present in a frame (e.g., an MPDU). The QoS control field may comprise one or more bits that may be allocated for an acknowledgment (ACK) policy field. The ACK policy field is part of each MPDU within each AMPDU. The ACK policy field may comprise two bits that may provide up to four different values (e.g., 0 0, 0 1, 1 0, and 1 1). In one example, if each of the MPDUs in an AMPDU carry an ACK policy field set to 0 0, this may indicate to the receiving station device, that may be decoding the MPDUs, that the receiving station device must send an immediate acknowledgment. If the ACK policy is set to 1 1, this may indicate to the receiving station device, that may be decoding the MPDUs, that the receiving station device should not send an acknowledgment unless the receiving station device gets a BAR from the AP/PCP. The other two ACK policy value of 0 1 and 1 0 may be used for a delayed acknowledgment such that a receiving device sends an ACK when it is able to.

[0039] In some demonstrative embodiments, the user device(s) 120 and/or the AP 102 may be configured to operate in accordance with one or more specifications, including one or more IEEE 802.11 specifications, (e.g., an IEEE 802. Had specification, an IEEE 802.11 ay specification, and/or any other specification and/or protocol). For example, an amendment to a DMG operation in the 60 GHz band, according to an IEEE 802. Had standard, may be defined, for example, by an IEEE 802.1 lay project.

[0040] In one embodiment, and with reference to FIG. 1, there is shown one or more aggregate MPDUs 140 (e.g., AMPDU 1...AMPDU i, i being an integer) that may be sent from an initiator device (e.g., AP 102 (or PCP) and/or user device 120) to one or more responder devices (e.g., AP 102 (or PCP) and/or user device 120). At least one of the one or more responder devices may respond with a block acknowledgment (BACK) (e.g., BACKi 142). It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0041] FIG. 2 depicts an illustrative schematic diagram for block acknowledgment for MU- MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0042] Referring to FIG. 2, there is shown an AP 202 that may be in a MU-MIMO communication with two STAs (e.g., user devices 222 and 224) that form an MU-MIMO group. The AP 202 may send an MU PPDU 204 comprised of a frame (e.g., an AMPDU) destined to user device 222 and another frame (e.g., an AMPDU) destined to user device 224.

[0043] In one embodiment, a block acknowledgment for MU-MIMO communication system may facilitate that one STA (e.g., user device 222) in an MU-MIMO group may be designated to immediately send a block acknowledgment after a channel delay time has passed from receiving an MU PPDU from an AP (e.g., AP 202). For example, when user device 222 receives its AMPDU frame in the MU PPDU 204, the user device 222 may be designated in that frame to be the first STA to send an acknowledgment (e.g., BACK 1 206). The user device 222 may wait for a channel delay time (e.g., a SIFS time) before sending its acknowledgment (e.g., BACK 1 206). [0044] In one embodiment, subsequent to the AP 202 receiving the BACK 1 206 from this STA, the AP 202 may send a block acknowledgment request (e.g., BAR 1 208) to another STA (e.g., user device 224), of the MU-MIMO group, whose block acknowledgment has not been received by the AP 202. This may solicit the user device 224 to send its block acknowledgment (e.g., BACK 1 210) to the AP. If there are any additional STAs in the MU-MIMO group, the AP may then send another block acknowledgment request to one of the STAs whose block acknowledgment has not been collected. Otherwise, the AP may send the next MU PPDU (e.g., MU PPDU 212). This solution has the flexibility to request BACK only from the STAs that AP has sent data to. However, it introduces inefficiencies and additional overhead caused by multiple BARs and respected BACKs.

[0045] The efficiency of this procedure may be calculated as follows:

[0046] Efficiency = TA_MPDU/(TA_MPDU+N*T_BA_CK+(N- 1)*T_BA_R+2*N*SIFS)

[0047] Where N is the number of MU MIMO users per MU MIMO group. TA_MPDU is the time needed to transmit an AMPDU as an MU PPDU to an MU MIMO user. T_BA_R is the time needed to transmit BAR. TRA_CK is the time needed to transmit a BACK. For simplicity, assume BACKs are sent using the same MCS, and hence T_RA_CK is the same for all MU MIMO users.

[0048] This results in inefficient use of bandwidth. It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0049] FIG. 3 depicts an illustrative schematic diagram for block acknowledgment for MU- MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0050] Referring to FIG. 3, there is shown an AP/PCP 302 that may be in a MU-MIMO communication with three STAs (e.g., user devices 322, 324, and 326) that form an MU-MIMO group. The AP/PCP 302 may send the MU PPDU 304 to a group of MU-MIMO STAs (e.g., the user devices 322, 324, and 326). The AP/PCP 302 may send an MU PPDU 304 comprised of one or more frames (e.g., one or more AMPDUs) destined to the user devices 322, 324, and 326.

[0051] In one embodiment, the block acknowledgment for MU-MIMO communication system option may assume that there is a mechanism for an AP/PCP 302 to indicate the order that each STA of an MU-MIMO group should send its BACK. Further, it is assumed that all the STAs of the MU-MEVIO group (e.g., user devices 322, 324, and 326) send their respective BACK using a fixed predefined MCS, so that each STA of the MU-MIMO group may calculate the time to start sending it BACK after obtaining its order for sending BACK. The predefined MCS may be set by AP/PCP 302 based on implementation- specific algorithms. The predefined MCS may be signaled in the downlink MU PPDU 304 or a block acknowledgment request sent from the AP/PCP 302.

[0052] In one embodiment, a block acknowledgment for MU-MIMO communication system may facilitate that one or more MU-MIMO STAs may acknowledge the receipt of an MU PPDU 304 from the AP/PCP 302 by sending their respective block acknowledgments (e.g., BACK 1 308, 310, and 312), in response to each of the STAs receiving their respective AMPDU from the MU PPDU 304, to the AP/PCP 302 sequentially. Alternatively, the order of the block acknowledgments (e.g., BACK 1 308, 310, and 312) from the STAs may be indicated in an MU BAR 1 frame 306 that may be sent by the AP/PCP 302. BAR 1 frame 306 may be comprised of one or more frames (e.g., BAR frames) destined to each of the STAs in the MU-MIMO group.

[0053] In one embodiment, a block acknowledgment for MU-MIMO communication system may facilitate the use of a BAR 1 frame (e.g., MU BAR frame 306) to indicate the order of sending BACK to STAs in the MU-MIMO group (e.g., the user devices 322, 324, and 326). The duration field within the BAR 1 frame may be set such that it covers all the BACKs that may follow so that all the STAs that receive the BAR 1 frame and that are not in the MU-MIMO group set their network allocation vectors (NAVs) to avoid interfering with the transmission of the BACKs that may follow.

[0054] In one embodiment, a block acknowledgment for MU-MIMO communication system may facilitate that one STA in the MU-MIMO group may send its BACK 1 after the passage of a channel access delay (e.g., SIFS) after receiving the MU PPDU 304 from AP/PCP 302, if the acknowledgment (ACK) policy for this STA is set to 0 0 (the rest of the STAs in the MU-MIMO group should have ACK policy set to 1 1 in the received MU PPDU 304).

[0055] In one embodiment, the AP/PCP 302) may send a BAR 1 frame in a MU-MIMO fashion (e.g., MU BAR) to the MU-MIMO group, which indicates the order of the following BACK. Other options of indicating the order of the following BACK 1 may be defined as well. For example, the order of each STA (e.g., the user devices 322, 324, and 326) in the MU-MIMO group can be predefined. Another way to define the order of each STAs is to use the order in the list of association IDs (AIDs) in the Header-A of the downlink MU PPDU 304.

[0056] The efficiency per user for the above procedure may be calculated as follows: [0057] Efficiency = TAMPDU / (TAMPDU+N*T_BACK+ T_BAR+ (N+2)*SIFS).

[0058] Where N is the number of MU MIMO users per MU MIMO group. TA_MPDU is the time needed to transmit an AMPDU as an MU PPDU to an MU MIMO user. T_BA_R is the time needed to transmit BAR 1. T_BA_CK is the time needed to transmit a BACK 1. For simplicity, assume BACKs are sent using the same MCS, and hence T_BA_CK is the same for all MU MIMO users.

[0059] It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0060] FIG. 4 depicts an illustrative schematic diagram for block acknowledgment for MU- MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0061] Referring to FIG. 4, there is shown an AP/PCP 402 that may be in a MU-MIMO communication with three STAs (e.g., user devices 422, 424, and 426) that form an MU-MIMO group. The AP/PCP 402 may send the MU PPDU 404 to a group of MU-MIMO STAs (e.g., the user devices 422, 424, and 426). The AP/PCP 402 may send an MU PPDU 404 comprised of one or more frames (e.g., one or more AMPDUs) destined to the user device 422, 424, and 426.

[0062] The AP/PCP 402 may send one MU PPDU (e.g., MU PPDU 404) with an ACK policy set to 0 0 for user device 422, and ACK policy set to 1 1 for user device 424 and user device 426. For example, AMPDU 432 may be destined to user device 422, AMPDU 434 may be destined to user device 424, and AMPDU 436 is destined to user device 426. The AP/PCP 402 may set the ACK policy in each of the MPDUs included in an AMPDU for the respective STA.

[0063] As explained before, a QoS control field may be present in a frame (e.g., an MPDU). The QoS control field may comprise one or more bits that may be allocated for an acknowledgment (ACK) policy field. The ACK policy field is part of each MPDU within each AMPDU. The ACK policy field may comprise two bits that may provide up to four different values (e.g., 0 0, 0 1, 1 0, and 1 1). In one example, if each of the MPDUs in an AMPDU carry an ACK policy field set to 0 0, this may indicate to the receiving station device, that may be decoding the MPDUs, that the receiving station device must send an immediate acknowledgment. If the ACK policy is set to 1 1, this may indicate to the receiving station device, that may be decoding the MPDUs, that the receiving station device should not send an acknowledgment unless the receiving station device gets a BAR 1 from the AP/PCP. The other two ACK policy values of 0 1 and 1 0 may be used for a delayed acknowledgment such that a receiving device sends an ACK when it is able to.

[0064] In one embodiment, after the user device 422 received its intended AMPDU 1 432, the user device 422 may send its BACK 1 438 after the passage a SIFS time after receiving the MU PPDU 404. The AP/PCP 402 then sends an MU BAR 1 406 to user devices 424 and 426. The user devices 424 and 426 may reply with their respective BACKs (e.g., BACK 1 440 and 442, respectively) sequentially according to an order that may be indicated in the MU BAR 406. The AP/PCP 402 may then send the next MU PPDU 2 408 and so on. It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0065] FIG. 5 depicts an illustrative schematic diagram for block acknowledgment for MU- MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0066] In one embodiment, a MU BAR frame may be made up of multiple BAR 1 frames having a common preamble. The common preamble may indicate to the STAs of MU-MIMO group, the number of STAs of the MU-MIMO group.

[0067] Referring to FIG. 5, there is shown a format of each BAR frame 500 formats as defined in the IEEE 802.11 standard. Specifically, the BAR frame 500 may include a frame control field, a duration field, a receiving station address field, a transmitting station address field, a BAR control field 502, a BAR information field, and a frame check sequence (FCS) field. The BAR control field may contain multiple fields, for example, a BAR ACK policy field, a multi-TID field, a compressed bitmap field, a group cast with the retries (GCR) field, a reserved field 504, and a TID_info field. In the case of the MU BAR frame, it may contain a MU BAR control field that may also contain similar fields as the BAR frame 500. For example, the MU BAR control field may contain a reserved field that may be used, to indicate to multiple STAs (up to eight STAs) the order of sending their respective block acknowledgments to the AP.

[0068] In one embodiment, a block acknowledgment for MU-MIMO communication system may facilitate using at least one of the multiple fields of the MU BAR control field to set the order that the devices in an MU-MIMO group should send their block acknowledgments. For example, in other embodiments, the block acknowledgment for MU-MIMO communication system may facilitate using at least one of the multiple fields of each individual BAR control frame of each respective BAR frame of the MU BAR frame to set the order that the devices in an MU-MIMO group should send their block acknowledgments. For example, three reserved bits of the reserved field 504 may be used to indicate to the destined STA its place in the order of sending its block acknowledgment to the AP.

[0069] In one embodiment, a block acknowledgment for MU-MIMO communication system may indicate the MCS value of each STA of the MU-MIMO group. The block acknowledgment may have a fixed predefined length. This way, all the STAs of the MU-MIMO group can calculate time start sending its respective block acknowledgment after obtaining the order from the MU BAR frame by knowing the length of the block acknowledgment frame and the respective MCS value used by each STA of the MU-MIMO group.

[0070] It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0071] FIG. 6 depicts an illustrative schematic diagram for block acknowledgment for MU- MIMO communication, in accordance with one or more example embodiments of the present disclosure.

[0072] Referring to FIG. 6, there is shown in an AP/PCP 602 that may be in a MU-MIMO communication with two STAs (e.g., user devices 622 and 624) that may be part of an MU- MIMO group.

[0073] In one embodiment, a block acknowledgment for MU-MIMO communication system may facilitate triggering one or more block acknowledgments from one or more STAs in an MU- MIMO group without the need for a MU BAR (or BAR) frame. For example, an AP/PCP may be able to trigger the one or more STA processes in an MU-MIMO group by simply sending one or more MU PPDUs. For example, AP/PCP 602 may send an MU PPDU (e.g., MU PPDU 604) comprised of one or more frames (e.g., one or more AMPDUs) to the user devices 622, and 624 , where each AMPDU MU PPDU may be destined to each STA of the MU-MIMO group. For example, the MU PPDU 604 may be comprised of two AMPDUs (e.g., AMPDUs 632 and 634), where AMPDU 632 is intended for STA 622 AMPDU 634 is intended for STA 624.

[0074] A QoS control field may be present in a frame (e.g., an MPDU). The QoS control field may comprise one or more bits that may be allocated for an acknowledgment (ACK) policy field. The ACK policy field is part of each MPDU within each AMPDU. The ACK policy field may comprise two bits that may provide up to four different values (e.g., 0 0, 0 1, 1 0, and 1 1). In one example, if each of the MPDUs in an AMPDU carry an ACK policy field set to 0 0, this may indicate to the receiving station device, that may be decoding the MPDUs, that the receiving station device must send an immediate acknowledgment. If the ACK policy is set to 1 1, this may indicate to the receiving station device, that may be decoding the MPDUs, that the receiving station device should not send an acknowledgment unless the receiving station device gets a BAR from the AP/PCP. The other two ACK policy values of 0 1 and 1 0 may be used for a delayed acknowledgment such that a receiving device sends an ACK when it is able to.

[0075] In one embodiment, a block acknowledgment for MU-MIMO communication system may facilitate that an AP/PCP may set the ACK of individual MPDUs within an AMPDU in order to trigger one or more block acknowledgment responses from the STAs in the MU-MIMO group. For example, in the MU PPDU 604, the AP/PCP 602 may set the ACK policy to 0 0 (immediate ACK) in the AMPDU intended for only one of the MU-MIMO STAs (e.g., user device 622), and set ACK policy to 1 1 to the rest of the STAs (e.g., user device 624) in the MU- MIMO group. The user device 622 that receives the AMPDU 632 with ACK Policy 0 0 will respond AP/PCP 602 with BACK 636 after the passage of a SIFS time. The BACK 636, however, is a block acknowledgment to AMPDU 632 and a previously received AMPDU from the AP/PCP 602. The BACK 636 in FIG. 6 is shown with a designation of "0 & 1" to indicate that this BACK 636 is in response to AMPDU 0 (not shown) and AMPDU 1 (e.g., AMPDU 632). The STAs (e.g., user device 624) that receives, their respective AMPDU (e.g., AMPDU 634) with ACK Policy 1 1 will record the state and will not respond with a BACK. After the AP/PCP 602 receives the BACK 636 from user device 622, the AP/PCP 602 may continue sending the next MU PPDU 606 to the group of MU-MIMO STAs (e.g., user devices 622 and 624). In the MU PPDU 606, the AP/PCP 602 will set ACK policy to 0 0 for another STA (e.g., user device 624) in its respective AMPDU, and set ACK policy to 1 1 to the rest of the STAs (e.g., user device 622) in their respective AMPDUs.. In the example of FIG. 6, BACK 640 is a block acknowledgment from user device 622 to MU PPDUs 606 and 608. The BACK 642 is a block acknowledgment from user device 624 to MU PPDUs 608 and 610. In fact, the AP/PCP 602 may collect BACK from only one STA after sending each MU PPDU, and the AP/PCP may continue to collect BACK from the STAs in a round-robin fashion.

[0076] In one embodiment, in case there is no data to be sent to one of the STAs of the MU- MIMO group, the AP/PCP may still be able to set the ACK policy to a 0 0 or a 1 1 by using a QoS Null frame. That is, in the case where there is no AMPDU frame allocated for a STA, the AP/PCP may send a QoS Null frame and may set the ACK policy in the QoS Null frame to reflect how the AP/PCP requires an acknowledgment from that STA.

[0077] The efficiency per user for this procedure may be calculated as follows:

[0078] Efficiency = N*TA_MPDU / (N*TA_MPDU+T_BAC_K+2*N*SIFS).

[0079] Where N is the number of MU MIMO users per MU MIMO group. TA_MPDU is the time needed to transmit an AMPDU as an MU PPDU to an MU MIMO user. T_BA_R is the time needed to transmit BAR. T_BA_CK is the time needed to transmit a BACK. For simplicity, assume BACKs are sent using the same MCS, and hence T_BA_CK is the same for all MU MIMO users.

[0080] It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0081] FIG. 7 A illustrates a flow diagram of illustrative process 700 for an illustrative block acknowledgment for MU-MIMO system, in accordance with one or more example embodiments of the present disclosure.

[0082] At block 702, a device (e.g., the user device(s) 120 and/or the AP 102 (or PCP) of FIG. 1) may determine a first multiuser frame comprised of one or more subframes to be sent to one or more devices (e.g., the user device(s) 120 and/or the AP 102 (or PCP) of FIG. 1) in a multiuser multiple input and multiple output (MU MIMO) group. For example, an AP may send a MU PPDU to a group of MU-MIMO STAs. The AP may send an MU PPDU comprised of one or more frames (e.g., one or more AMPDUs) destined to the STAs.

[0083] An AMPDU is an aggregation of one or more MPDUs. An MU PPDU may be composed of one or more MPDUs or one or more AMPDUs. The MU PPDU may include a PHY preamble in order to be a message at the PHY layer between peer entities in a communication system. The PHY preamble may be a common PHY preamble designated for all the packets within the MU PPDU (e.g., MPDUs or AMPDUs). For example, if the AP has a plurality of antennas, a first antenna may send a first AMPDU of the MU PPDU to a first STA, the second antenna may send a second AMPDU of the MU PPDU to a second STA, and so forth. This mechanism is also similar for sending MPDUs to one or more STAs. When each of the STAs receives the MU PPDU, it decodes the PHY preamble, determines which MPDU or AMPDU is destined for it. In essence, an MU PPDU is a single frame with multiple frames transmitted to different STAs using multiple spatial streams. [0084] At block 704, the device may cause to set a first acknowledgement policy field in a first subframe of the first multiuser frame. For example, a QoS control field may be present in a frame (e.g., an MPDU). The QoS control field may comprise one or more bits that may be allocated for an acknowledgment (ACK) policy field. The ACK policy field is part of each MPDU within each AMPDU. The ACK policy field may comprise two bits that may provide up to four different values (e.g., 0 0, 0 1, 1 0, and 1 1). In one example, if each of the MPDUs in an AMPDU carry an ACK policy field set to 0 0, this may indicate to the receiving station device, that may be decoding the MPDUs, that the receiving station device must send an immediate acknowledgment. If the ACK policy is set to 1 1, this may indicate to the receiving station device, that may be decoding the MPDUs, that the receiving station device should not send an acknowledgment unless the receiving station device gets a BAR from the AP/PCP. The other two ACK policy values of 0 1 and 1 0 may be used for a delayed acknowledgment such that a receiving device sends an ACK when it is able to.

[0085] At block 706, the device may cause to send the first MU frame to the one or more devices. For example, the AP may send the MU PPDU to the STAs in the MU MIMO group. The MU PPDU may include the ACK policy field for each of the MPDU.

[0086] At block 708, the device may identify a first block acknowledgement frame received from a first device of the one or more devices. After a STA receives its intended AMPDU, the STA may send its BACK after the passage a SIFS time after receiving the MU PPDU. The AP then sends an MU BAR to STAs. The STAs may reply with their respective BACKs sequentially according to an order that may be indicated in the MU BAR. The AP may then send the next MU PPDU and so on. It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0087] FIG. 7B illustrates a flow diagram of illustrative process 750 for a block acknowledgment for MU-MIMO system, in accordance with one or more example embodiments of the present disclosure.

[0088] At block 752, a device (e.g., the user device(s) 120 and/or the AP 102 (or PCP) of FIG. 1) may identify a multiuser frame received from a device in a multiuser multiple input multiple output (MU MIMO) group. For example, an STA may receive an MU PPDU frame based on the fact that the STA is part of an MU MIMO group with an AP or PCP. An AMPDU is an aggregation of one or more MPDUs. An MU PPDU may be composed of one or more MPDUs or one or more AMPDUs. The MU PPDU may include a PHY preamble in order to be a message at the PHY layer between peer entities in a communication system. The PHY preamble may be a common PHY preamble designated for all the packets within the MU PPDU (e.g., MPDUs or AMPDUs). The STA may decode the fields included in each of the MPDUs that may be destined for it. For example, the STA may decode an acknowledgment policy field.

[0089] At block 754, the device may determine an acknowledgement policy field in the multiuser frame. The QoS control field may comprise one or more bits that may be allocated for an acknowledgment (ACK) policy field. The ACK policy field is part of each MPDU within each AMPDU. The ACK policy field may comprise two bits that may provide up to four different values (e.g., 0 0, 0 1, 1 0, and 1 1). In one example, if each of the MPDUs in an AMPDU carry an ACK policy field set to 0 0, this may indicate to the receiving station device, that may be decoding the MPDUs, that the receiving station device must send an immediate acknowledgment. If the ACK policy is set to 1 1, this may indicate to the receiving station device, that may be decoding the MPDUs, that the receiving station device should not send an acknowledgment unless the receiving station device gets a BAR from the AP/PCP. The other two ACK policy values of 0 1 and 1 0 may be used for a delayed acknowledgment such that a receiving device sends an ACK when it is able to.

[0090] At block 756, the device may determine to send a block acknowledgement frame to the device based at least in part on the acknowledgement policy field. For example, if the ACK policy is set to 0 0, the STA may send its BACK immediately after receiving the MU PPDU from the AP or PCP.

[0091] It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0092] FIG. 8 shows a functional diagram of an exemplary communication station 800 in accordance with some embodiments. In one embodiment, FIG. 8 illustrates a functional block diagram of a communication station that may be suitable for use as an AP 102 (FIG. 1) or a user device 120 (FIG. 1) in accordance with some embodiments. The communication station 800 may also be suitable for use as a handheld device, a mobile device, a cellular telephone, a smartphone, a tablet, a netbook, a wireless terminal, a laptop computer, a wearable computer device, a femtocell, a high data rate (HDR) subscriber station, an access point, an access terminal, or other personal communication system (PCS) device. [0093] The communication station 800 may include communications circuitry 802 and a transceiver 810 for transmitting and receiving signals to and from other communication stations using one or more antennas 801. The transceiver 810 may be a device comprising both a transmitter and a receiver that are combined and share common circuitry (e.g., communication circuitry 802). The communication circuitry 802 may include amplifiers, filters, mixers, analog to digital and/or digital to analog converters. The transceiver 810 may transmit and receive analog or digital signals. The transceiver 810 may allow reception of signals during transmission periods. This mode is known as full-duplex, and may require the transmitter and receiver to operate on different frequencies to minimize interference between the transmitted signal and the received signal. The transceiver 810 may operate in a half-duplex mode, where the transceiver 810 may transmit or receive signals in one direction at a time.

[0094] The communications circuitry 802 may include circuitry that can operate the physical layer (PHY) communications and/or media access control (MAC) communications for controlling access to the wireless medium, and/or any other communications layers for transmitting and receiving signals. The communication station 800 may also include processing circuitry 806 and memory 808 arranged to perform the operations described herein. In some embodiments, the communications circuitry 802 and the processing circuitry 806 may be configured to perform operations detailed in FIGs. 2, 3, 4, 5A and 5B.

[0095] In accordance with some embodiments, the communications circuitry 802 may be arranged to contend for a wireless medium and configure frames or packets for communicating over the wireless medium. The communications circuitry 802 may be arranged to transmit and receive signals. The communications circuitry 802 may also include circuitry for modulation/demodulation, upconversion/downconversion, filtering, amplification, etc. In some embodiments, the processing circuitry 806 of the communication station 800 may include one or more processors. In other embodiments, two or more antennas 801 may be coupled to the communications circuitry 802 arranged for sending and receiving signals. The memory 808 may store information for configuring the processing circuitry 806 to perform operations for configuring and transmitting message frames and performing the various operations described herein. The memory 808 may include any type of memory, including non-transitory memory, for storing information in a form readable by a machine (e.g., a computer). For example, the memory 808 may include a computer-readable storage device , read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash- memory devices and other storage devices and media.

[0096] In some embodiments, the communication station 800 may be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), a wearable computer device, or another device that may receive and/or transmit information wirelessly.

[0097] In some embodiments, the communication station 800 may include one or more antennas 801. The antennas 801 may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmission of RF signals. In some embodiments, instead of two or more antennas, a single antenna with multiple apertures may be used. In these embodiments, each aperture may be considered a separate antenna. In some multiple-input multiple-output (MIMO) embodiments, the antennas may be effectively separated for spatial diversity and the different channel characteristics that may result between each of the antennas and the antennas of a transmitting station.

[0098] In some embodiments, the communication station 800 may include one or more of a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an LCD screen including a touch screen.

[0099] Although the communication station 800 is illustrated as having several separate functional elements, two or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio- frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements of the communication station 800 may refer to one or more processes operating on one or more processing elements. [00100] Certain embodiments may be implemented in one or a combination of hardware, firmware, and software. Other embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory memory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. In some embodiments, the communication station 800 may include one or more processors and may be configured with instructions stored on a computer-readable storage device memory.

[00101] FIG. 9 illustrates a block diagram of an example of a machine 900 or system upon which any one or more of the techniques (e.g., methodologies) discussed herein may be performed. In other embodiments, the machine 900 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine 900 may operate in the capacity of a server machine, a client machine, or both in server-client network environments. In an example, the machine 900 may act as a peer machine in peer-to- peer (P2P) (or other distributed) network environments. The machine 900 may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile telephone, a wearable computer device, a web appliance, a network router, a switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine, such as a base station. Further, while only a single machine is illustrated, the term "machine" shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), or other computer cluster configurations.

[00102] Examples, as described herein, may include or may operate on logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations when operating. A module includes hardware. In an example, the hardware may be specifically configured to carry out a specific operation (e.g., hardwired). In another example, the hardware may include configurable execution units (e.g., transistors, circuits, etc.) and a computer readable medium containing instructions where the instructions configure the execution units to carry out a specific operation when in operation. The configuring may occur under the direction of the executions units or a loading mechanism. Accordingly, the execution units are communicatively coupled to the computer-readable medium when the device is operating. In this example, the execution units may be a member of more than one module. For example, under operation, the execution units may be configured by a first set of instructions to implement a first module at one point in time and reconfigured by a second set of instructions to implement a second module at a second point in time.

[00103] The machine (e.g., computer system) 900 may include a hardware processor 902 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 904 and a static memory 906, some or all of which may communicate with each other via an interlink (e.g., bus) 908. The machine 900 may further include a power management device 932, a graphics display device 910, an alphanumeric input device 912 (e.g., a keyboard), and a user interface (UI) navigation device 914 (e.g., a mouse). In an example, the graphics display device 910, alphanumeric input device 912, and UI navigation device 914 may be a touch screen display. The machine 900 may additionally include a storage device (i.e., drive unit) 916, a signal generation device 918 (e.g., a speaker), a block acknowledgment for MU-MEVIO device 919, a network interface device/transceiver 920 coupled to antenna(s) 930, and one or more sensors 928, such as a global positioning system (GPS) sensor, a compass, an accelerometer, or other sensor. The machine 900 may include an output controller 934, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate with or control one or more peripheral devices (e.g., a printer, a card reader, etc.)).

[00104] The storage device 916 may include a machine readable medium 922 on which is stored one or more sets of data structures or instructions 924 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 924 may also reside, completely or at least partially, within the main memory 904, within the static memory 906, or within the hardware processor 902 during execution thereof by the machine 900. In an example, one or any combination of the hardware processor 902, the main memory 904, the static memory 906, or the storage device 916 may constitute machine-readable media.

[00105] The block acknowledgment for MU-MIMO device 919 may carry out or perform any of the operations and processes (e.g., processes 400 and 500) described and shown above. For example, the block acknowledgment for MU-MIMO device 919 may facilitate that one STA in an MU-MIMO group may be designated to immediately send a block acknowledgment after a channel delay time has passed from receiving an MU PPDU from an access point (AP) or a personal basic service set (PBSS) control point (PCP). Subsequent to the AP (or PCP) receiving the block acknowledgment from this STA, the AP may send a block acknowledgment request to another STA of the MU-MIMO group, whose block acknowledgment has not been received by the AP. This may solicit the STA to send its block acknowledgment to the AP. If there are additional STAs in the MU-MIMO group, the AP may then send another block acknowledgment request to one of the STAs whose block acknowledgment has not been collected.

[00106] The block acknowledgment for MU-MIMO device 919 may facilitate that one or more MU-MIMO STAs may acknowledge the receipt of an MU PPDU from an AP or PCP by sending a block acknowledgment (BACK) to the AP/PCP sequentially. Additionally, and/or alternatively, the order of the acknowledgments from the STAs may be indicated in an MU block acknowledgment request (BAR) frame that may be sent by the AP/PCP.

[00107] The block acknowledgment for MU-MIMO device 919 may facilitate that an AP/PCP may trigger the receipt of one or more BACKs from one or more STAs based at least in part on setting an acknowledgment policy bit(s). For example, an AP/PCP may send an MU PPDU to a group of MU-MIMO STAs. In the MU PPDU, the AP/PCP may set the ACK policy to 0 0 to only one of the MU-MIMO STAs, and set the ACK policy to 1 1 (BACK) to the rest of the STAs in the MU-MIMO group. The STA that receives the MU PPDU with ACK Policy 0 0 may respond AP/PCP with BACK after a short inter-frame space (SIFS) time. The STAs that receive the MU PPDU with ACK Policy 1 1 may record the state and may not respond with a BACK. The AP/PCP may receive the BACK from one STA, and continue sending the next MU PPDU to the group of MU-MIMO STAs. In the MU PPDU, the AP/PCP may set the ACK policy to 0 0 for another STA in the MU-MIMO group, and set the ACK policy to 1 1 to the rest of the STAs in the MU-MIMO group. In fact, the AP/PCP may collect BACK from only one STA after sending each MU PPDU, and the AP/PCP may collect BACK from STAs in a round-robin fashion.

[00108] It is understood that the above are only a subset of what the block acknowledgment for MU-MIMO device 919 may be configured to perform and that other functions included throughout this disclosure may also be performed by the block acknowledgment for MU-MIMO device 919.

[00109] While the machine-readable medium 922 is illustrated as a single medium, the term "machine-readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 924.

[00110] Various embodiments may be implemented fully or partially in software and/or firmware. This software and/or firmware may take the form of instructions contained in or on a non-transitory computer-readable storage medium. Those instructions may then be read and executed by one or more processors to enable performance of the operations described herein. The instructions may be in any suitable form, such as but not limited to source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. Such a computer-readable medium may include any tangible non-transitory medium for storing information in a form readable by one or more computers, such as but not limited to read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; a flash memory, etc.

[00111] The term "machine-readable medium" may include any medium that is capable of storing, encoding, or carrying instructions for execution by the machine 900 and that cause the machine 900 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding, or carrying data structures used by or associated with such instructions. Non-limiting machine-readable medium examples may include solid-state memories and optical and magnetic media. In an example, a massed machine-readable medium includes a machine-readable medium with a plurality of particles having resting mass. Specific examples of massed machine-readable media may include non- volatile memory, such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), or electrically erasable programmable read-only memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD- ROM disks.

[00112] The instructions 924 may further be transmitted or received over a communications network 926 using a transmission medium via the network interface device/transceiver 920 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communications networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), plain old telephone (POTS) networks, wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi®, IEEE 802.16 family of standards known as WiMax®), IEEE 802.15.4 family of standards, and peer-to-peer (P2P) networks, among others. In an example, the network interface device/transceiver 920 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network 926. In an example, the network interface device/transceiver 920 may include a plurality of antennas to wirelessly communicate using at least one of single-input multiple-output (SEVIO), multiple-input multiple- output (MEVIO), or multiple-input single-output (MISO) techniques. The term "transmission medium" shall be taken to include any intangible medium that is capable of storing, encoding, or carrying instructions for execution by the machine 900 and includes digital or analog communications signals or other intangible media to facilitate communication of such software. The operations and processes described and shown above may be carried out or performed in any suitable order as desired in various implementations. Additionally, in certain implementations, at least a portion of the operations may be carried out in parallel. Furthermore, in certain implementations, less than or more than the operations described may be performed.

[00113] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The terms "computing device," "user device," "communication station," "station," "handheld device," "mobile device," "wireless device" and "user equipment" (UE) as used herein refers to a wireless communication device such as a cellular telephone, a smartphone, a tablet, a netbook, a wireless terminal, a laptop computer, a femtocell, a high data rate (HDR) subscriber station, an access point, a printer, a point of sale device, an access terminal, or other personal communication system (PCS) device. The device may be either mobile or stationary.

[00114] As used within this document, the term "communicate" is intended to include transmitting, or receiving, or both transmitting and receiving. This may be particularly useful in claims when describing the organization of data that is being transmitted by one device and received by another, but only the functionality of one of those devices is required to infringe the claim. Similarly, the bidirectional exchange of data between two devices (both devices transmit and receive during the exchange) may be described as "communicating," when only the functionality of one of those devices is being claimed. The term "communicating" as used herein with respect to a wireless communication signal includes transmitting the wireless communication signal and/or receiving the wireless communication signal. For example, a wireless communication unit, which is capable of communicating a wireless communication signal, may include a wireless transmitter to transmit the wireless communication signal to at least one other wireless communication unit, and/or a wireless communication receiver to receive the wireless communication signal from at least one other wireless communication unit.

[00115] As used herein, unless otherwise specified, the use of the ordinal adjectives "first," "second," "third," etc., to describe a common object, merely indicates that different instances of like objects are being referred to and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

[00116] The term "access point" (AP) as used herein may be a fixed station. An access point may also be referred to as an access node, a base station, an evolved node B (eNodeB), or some other similar terminology known in the art. An access terminal may also be called a mobile station, user equipment (UE), a wireless communication device, or some other similar terminology known in the art. Embodiments disclosed herein generally pertain to wireless networks. Some embodiments may relate to wireless networks that operate in accordance with one of the IEEE 802.11 standards.

[00117] Some embodiments may be used in conjunction with various devices and systems, for example, a personal computer (PC), a desktop computer, a mobile computer, a laptop computer, a notebook computer, a tablet computer, a server computer, a handheld computer, a handheld device, a personal digital assistant (PDA) device, a handheld PDA device, an on-board device, an off-board device, a hybrid device, a vehicular device, a non-vehicular device, a mobile or portable device, a consumer device, a non-mobile or non-portable device, a wireless communication station, a wireless communication device, a wireless access point (AP), a wired or wireless router, a wired or wireless modem, a video device, an audio device, an audio-video (A/V) device, a wired or wireless network, a wireless area network, a wireless video area network (WVAN), a local area network (LAN), a wireless LAN (WLAN), a personal area network (PAN), a wireless PAN (WPAN), and the like. [00118] Some embodiments may be used in conjunction with one way and/or two-way radio communication systems, cellular radio-telephone communication systems, a mobile phone, a cellular telephone, a wireless telephone, a personal communication system (PCS) device, a PDA device which incorporates a wireless communication device, a mobile or portable global positioning system (GPS) device, a device which incorporates a GPS receiver or transceiver or chip, a device which incorporates an RFID element or chip, a multiple input multiple output (MIMO) transceiver or device, a single input multiple output (SIMO) transceiver or device, a multiple input single output (MISO) transceiver or device, a device having one or more internal antennas and/or external antennas, digital video broadcast (DVB) devices or systems, multi- standard radio devices or systems, a wired or wireless handheld device, e.g., a smartphone, a wireless application protocol (WAP) device, or the like.

[00119] Some embodiments may be used in conjunction with one or more types of wireless communication signals and/or systems following one or more wireless communication protocols, for example, radio frequency (RF), infrared (IR), frequency-division multiplexing (FDM), orthogonal FDM (OFDM), time-division multiplexing (TDM), time-division multiple access (TDM A), extended TDMA (E-TDMA), general packet radio service (GPRS), extended GPRS, code-division multiple access (CDMA), wideband CDMA (WCDMA), CDMA 2000, single- carrier CDMA, multi-carrier CDMA, multi-carrier modulation (MDM), discrete multi-tone (DMT), Bluetooth®, global positioning system (GPS), Wi-Fi, Wi-Max, ZigBee, ultra-wideband (UWB), global system for mobile communications (GSM), 2G, 2.5G, 3G, 3.5G, 4G, fifth generation (5G) mobile networks, 3GPP, long term evolution (LTE), LTE advanced, enhanced data rates for GSM Evolution (EDGE), or the like. Other embodiments may be used in various other devices, systems, and/or networks.

[00120] According to example embodiments of the disclosure, there may be a device. The device may include memory and processing circuitry configured to determine a first multiuser (MU) frame comprised of one or more subframes to be sent to one or more devices in at least one of an orthogonal frequency-division multiple access (OFDM A) group or an MU multiple input and multiple output (MU MIMO) group. The processing circuitry may be further configured to cause to set a first acknowledgement policy field in a first subframe of the first MU frame. The processing circuitry may be further configured to cause to send the first MU frame to the one or more devices. The processing circuitry may be further configured to identify a first block acknowledgement frame received from a first device of the one or more devices corresponding to the first acknowledgement policy field in the first subframe.

[00121] The implementations may include one or more of the following features. The processing circuitry may be further configured to cause to send a second MU frame to the one or more devices after identifying the block acknowledgment frame from the first device. The second MU frame is an MU block acknowledgment request frame comprised of one or more block acknowledgment request subframes. Each of the one or more block acknowledgment requests subframes contains a block acknowledgment control field containing an indication of an order that the one or more devices are to send their respective block acknowledgment frames. The first MU frame is an aggregated media access control protocol data unit (A-MPDU) and wherein the one or more subframes are physical layer convergence protocol data units (PPDUs). Each of the one or more block acknowledgment requests subframes is caused to be sent to a respective device of the one or more devices. The first acknowledgement policy field is included in a first PPDU of the one or more subframes in an MU frame, and wherein the first PPDU may include a destination field in the first subframe associated with the first device. The first acknowledgement policy field is comprised of two bits, and wherein the two bits are both set to "0" to indicate that the first block acknowledgement frame is to be sent by the first device after a short inter-frame space time from receiving the first MU frame. The block acknowledgment from the first device is received after a short inter-frame space time. The device may further include a transceiver configured to transmit and receive wireless signals. The device may further include one or more antennas coupled to the transceiver.

[00122] According to example embodiments of the disclosure, there may be a device. The device may include memory and processing circuitry configured to identify a multiuser (MU) frame received from a device in at least one of an orthogonal frequency-division multiple access (OFDMA) group or an MU multiple input multiple output (MU MEVIO) group. The processing circuitry may be further configured to determine an acknowledgement policy field in the MU frame. The processing circuitry may be further configured to determine to send a block acknowledgement frame to the device based at least in part on the acknowledgement policy field.

[00123] The implementations may include one or more of the following features. The block acknowledgment is sent after a short inter-frame space (SIFS) time. The operations to determine to send the block acknowledgment frame further comprise determining two bits of the acknowledgement policy field are both set to "0". The operations further comprise determining two bits of the acknowledgement policy field are both set to "1". A "1 1" value of the acknowledgement policy field indicates to hold off sending a block acknowledgment to the MU frame until receiving a block acknowledgment request from the device. The MU frame is an aggregated media access control protocol data unit (AMPDU) containing one or more subframes are physical layer convergence protocol data units (PPDUs). The device may further include a transceiver configured to transmit and receive wireless signals. The device may further include one or more antennas coupled to the transceiver.

[00124] According to example embodiments of the disclosure, there may be a non-transitory computer-readable medium storing computer-executable instructions which, when executed by a processor, cause the processor to perform operations. The operations may include identifying a multiuser (MU) frame received from a device in at least one of an orthogonal frequency-division multiple access (OFDMA) group or an MU multiple input multiple output (MU MIMO) group. The operations may include determining an acknowledgement policy field in the MU frame. The operations may include determining to send a block acknowledgement frame to the device based at least in part on the acknowledgement policy field.

[00125] The implementations may include one or more of the following features. The block acknowledgment is sent after a short inter-frame space (SIFS) time. The operations to determine to send the block acknowledgment frame further comprise determining two bits of the acknowledgement policy field are both set to "0". The operations further comprise determining two bits of the acknowledgement policy field are both set to "1". A "1 1" value of the acknowledgement policy field indicates to hold off sending a block acknowledgment to the MU frame until receiving a block acknowledgment request from the device. The MU frame is an aggregated media access control protocol data unit (AMPDU) containing one or more subframes are physical layer convergence protocol data units (PPDUs).

[00126] According to example embodiments of the disclosure, there may be a non-transitory computer-readable medium storing computer-executable instructions which, when executed by a processor, cause the processor to perform operations. The operations may include determining, by one or more processors, a first multiuser (MU) frame comprised of one or more subframes to be sent to one or more devices in at least one of an orthogonal frequency-division multiple access (OFDMA) group or an MU multiple input and multiple output (MU MIMO) group. The operations may include causing to set a first acknowledgement policy field in a first subframe of the first MU frame. The operations may include causing to send the first MU frame to the one or more devices. The operations may include identifying a first block acknowledgement frame received from a device of the one or more devices corresponding to the acknowledgement policy field value in the first subframe.

[00127] The implementations may include one or more of the following features. The operations further comprise causing to send a second MU frame to the one or more devices after receiving the block acknowledgment frame from the device receiving the first subframe with the first acknowledgment policy field in the MU frame. The second MU frame is a MU block acknowledgment request frame comprised of one or more block acknowledgment request subframes. Each of the one or more block acknowledgment requests subframes contains a block acknowledgment control field containing an indication of an order that the one or more devices are to send their respective block acknowledgment frames. The first MU frame is an aggregated media access control protocol data unit (A-MPDU) and wherein the one or more subframes are physical layer convergence protocol data units (PPDUs). Each of the one or more block acknowledgment requests subframes is caused to be sent to a respective device of the one or more devices. The first acknowledgement policy field is included in a first PPDU of the one or more subframes in an MU frame, and wherein the first PPDU may include a destination field in the first subframe associated with the first device. The first acknowledgement policy field is comprised of two bits, and wherein the two bits are both set to "0" to indicate that the first block acknowledgement frame is to be sent by the first device after a short inter-frame space time from receiving the first MU frame.

[00128] According to example embodiments of the disclosure, there may include a method. The method may include determining, by one or more processors, a first multiuser (MU) frame comprised of one or more subframes to be sent to one or more devices in at least one of an orthogonal frequency-division multiple access (OFDMA) group or an MU multiple input and multiple output (MU MIMO) group. The method may include causing to set a first acknowledgement policy field in a first subframe of the first MU frame. The method may include causing to send the first MU frame to the one or more devices. The method may include identifying a first block acknowledgement frame received from a device of the one or more devices corresponding to the acknowledgement policy field value in the first subframe. [00129] The implementations may include one or more of the following features. The method may further include causing to send a second MU frame to the one or more devices after receiving the block acknowledgment frame from the device receiving the first subframe with the first acknowledgment policy field in the MU frame. The second MU frame is a MU block acknowledgment request frame comprised of one or more block acknowledgment request subframes. Each of the one or more block acknowledgment requests subframes contains a block acknowledgment control field containing an indication of an order that the one or more devices are to send their respective block acknowledgment frames. The first MU frame is an aggregated media access control protocol data unit (A-MPDU) and wherein the one or more subframes are physical layer convergence protocol data units (PPDUs). Each of the one or more block acknowledgment requests subframes is caused to be sent to a respective device of the one or more devices. The first acknowledgement policy field is included in a first PPDU of the one or more subframes in an MU frame, and wherein the first PPDU includes a destination field in the first subframe associated with the first device. The first acknowledgement policy field is comprised of two bits, and wherein the two bits are both set to "0" to indicate that the first block acknowledgement frame is to be sent by the first device after a short inter-frame space time from receiving the first MU frame.

[00130] According to example embodiments of the disclosure, there may include a method. The method may include identifying a multiuser (MU) frame received from a device in at least one of an orthogonal frequency-division multiple access (OFDMA) group or an MU multiple input multiple output (MU MEVIO) group. The method may include determining an acknowledgement policy field in the MU frame. The method may include determining to send a block acknowledgement frame to the device based at least in part on the acknowledgement policy field.

[00131] The implementations may include one or more of the following features. The block acknowledgment is sent after a short inter-frame space (SIFS) time. The method wherein determining to send the block acknowledgment frame further comprise determining two bits of the acknowledgement policy field are both set to "0". The method may further include determining two bits of the acknowledgement policy field are both set to "1". A "1 1" value of the acknowledgement policy field indicates to hold off sending a block acknowledgment to the MU frame until receiving a block acknowledgment request from the device. The MU frame is an aggregated media access control protocol data unit (AMPDU) containing one or more subframes are physical layer convergence protocol data units (PPDUs).

[00132] In example embodiments of the disclosure, there may be an apparatus. The apparatus may include means for determining, by one or more processors, a first multiuser (MU) frame comprised of one or more subframes to be sent to one or more devices in at least one of an orthogonal frequency-division multiple access (OFDMA) group or an MU multiple input and multiple output (MU MIMO) group. The apparatus may include means for causing to set a first acknowledgement policy field in a first subframe of the first MU frame. The apparatus may include means for causing to send the first MU frame to the one or more devices. The apparatus may include means for identifying a first block acknowledgement frame received from a device of the one or more devices corresponding to the acknowledgement policy field value in the first subframe.

[00133] The implementations may include one or more of the following features. The apparatus may further include means for causing to send a second MU frame to the one or more devices after receiving the block acknowledgment frame from the device receiving the first subframe with the first acknowledgment policy field in the MU frame. The second MU frame is a MU block acknowledgment request frame comprised of one or more block acknowledgment request subframes. Each of the one or more block acknowledgment requests subframes contains a block acknowledgment control field containing an indication of an order that the one or more devices are to send their respective block acknowledgment frames. The first MU frame is an aggregated media access control protocol data unit (A-MPDU) and wherein the one or more subframes are physical layer convergence protocol data units (PPDUs). Each of the one or more block acknowledgment requests subframes is caused to be sent to a respective device of the one or more devices. The first acknowledgement policy field is included in a first PPDU of the one or more subframes in an MU frame, and wherein the first PPDU includes a destination field in the first subframe associated with the first device. The first acknowledgement policy field is comprised of two bits, and wherein the two bits are both set to "0" to indicate that the first block acknowledgement frame is to be sent by the first device after a short inter-frame space time from receiving the first MU frame.

[00134] Certain aspects of the disclosure are described above with reference to block and flow diagrams of systems, methods, apparatuses, and/or computer program products according to various implementations. It will be understood that one or more blocks of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and the flow diagrams, respectively, may be implemented by computer-executable program instructions. Likewise, some blocks of the block diagrams and flow diagrams may not necessarily need to be performed in the order presented, or may not necessarily need to be performed at all, according to some implementations .

[00135] These computer-executable program instructions may be loaded onto a special- purpose computer or other particular machine, a processor, or other programmable data processing apparatus to produce a particular machine, such that the instructions that execute on the computer, processor, or other programmable data processing apparatus create means for implementing one or more functions specified in the flow diagram block or blocks. These computer program instructions may also be stored in a computer-readable storage media or memory that may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage media produce an article of manufacture including instruction means that implement one or more functions specified in the flow diagram block or blocks. As an example, certain implementations may provide for a computer program product, comprising a computer-readable storage medium having a computer-readable program code or program instructions implemented therein, said computer-readable program code adapted to be executed to implement one or more functions specified in the flow diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational elements or steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions that execute on the computer or other programmable apparatus provide elements or steps for implementing the functions specified in the flow diagram block or blocks.

[00136] Accordingly, blocks of the block diagrams and flow diagrams support combinations of means for performing the specified functions, combinations of elements or steps for performing the specified functions and program instruction means for performing the specified functions. It will also be understood that each block of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and flow diagrams, may be implemented by special-purpose, hardware-based computer systems that perform the specified functions, elements or steps, or combinations of special-purpose hardware and computer instructions.

[00137] Conditional language, such as, among others, "can," "could," "might," or "may," unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain implementations could include, while other implementations do not include, certain features, elements, and/or operations. Thus, such conditional language is not generally intended to imply that features, elements, and/or operations are in any way required for one or more implementations or that one or more implementations necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or operations are included or are to be performed in any particular implementation.

[00138] Many modifications and other implementations of the disclosure set forth herein will be apparent having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosure is not to be limited to the specific implementations disclosed and that modifications and other implementations are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

CLAIMS What is claimed is:

1. A device, the device comprising memory and processing circuitry configured to:

determine a first multiuser (MU) frame comprised of one or more subframes to be sent to one or more devices in at least one of an orthogonal frequency-division multiple access (OFDMA) group or an MU multiple input and multiple output (MU MIMO) group;

cause to set a first acknowledgement policy field in a first subframe of the first MU frame;

cause to send the first MU frame to the one or more devices; and

identify a first block acknowledgement frame received from a first device of the one or more devices corresponding to the first acknowledgement policy field in the first subframe.

2. The device of claim 1, wherein the processing circuitry is further configured to cause to send a second MU frame to the one or more devices after identifying the block

acknowledgment frame from the first device.

3. The device of claim 2, wherein the second MU frame is an MU block acknowledgment request frame comprised of one or more block acknowledgment request subframes.

4. The device of claim 3, wherein each of the one or more block acknowledgment requests subframes contains a block acknowledgment control field containing an indication of an order that the one or more devices are to send their respective block acknowledgment frames.

5. The device of claim 1, wherein the first MU frame is an aggregated media access control protocol data unit (A-MPDU) and wherein the one or more subframes are physical layer convergence protocol data units (PPDUs).

6. The device of claim 3, wherein each of the one or more block acknowledgment requests subframes is caused to be sent to a respective device of the one or more devices.

7. The device of claim 5, wherein the first acknowledgement policy field is included in a first PPDU of the one or more subframes in an MU frame, and wherein the first PPDU includes a destination field in the first subframe associated with the first device.

8. The device of claim 1, wherein the first acknowledgement policy field is comprised of two bits, and wherein the two bits are both set to "0" to indicate that the first block

acknowledgement frame is to be sent by the first device after a short inter-frame space time from receiving the first MU frame.

9. The device of claim 1, wherein the block acknowledgment from the first device is received after a short inter-frame space time.

10. The device of claim 1, further comprising a transceiver configured to transmit and receive wireless signals.

11. The device of claim 10, further comprising one or more antennas coupled to the transceiver.

12. A non-transitory computer-readable medium storing computer-executable instructions which when executed by one or more processors result in performing operations comprising:

identifying a multiuser (MU) frame received from a device in at least one of an orthogonal frequency-division multiple access (OFDM A) group or an MU multiple input multiple output (MU MIMO) group;

determining an acknowledgement policy field in the MU frame;

determining to send a block acknowledgement frame to the device based at least in part on the acknowledgement policy field.

13. The non-transitory computer-readable medium of claim 12, wherein the block acknowledgment is sent after a short inter-frame space (SIFS) time.

14. The non-transitory computer-readable medium of claim 12, wherein the operations to determine to send the block acknowledgment frame further comprise determining two bits of the acknowledgement policy field are both set to "0".

15. The non-transitory computer-readable medium of claim 12, wherein the operations further comprise determining two bits of the acknowledgement policy field are both set to "1".

16. The non-transitory computer-readable medium of claim 12, wherein a "1 1" value of the acknowledgement policy field indicates to hold off sending a block acknowledgment to the MU frame until receiving a block acknowledgment request from the device.

17. The non-transitory computer-readable medium of claim 12, wherein the MU frame is an aggregated media access control protocol data unit (AMPDU) containing one or more subframes are physical layer convergence protocol data units (PPDUs).

18. A method comprising :

determining, by one or more processors, a first multiuser (MU) frame comprised of one or more subframes to be sent to one or more devices in at least one of an

orthogonal frequency-division multiple access (OFDM A) group or an MU multiple input and multiple output (MU MIMO) group;

causing to set a first acknowledgement policy field in a first subframe of the first MU frame;

causing to send the first MU frame to the one or more devices; and

identifying a first block acknowledgement frame received from a device of the one or more devices corresponding to the acknowledgement policy field value in the first subframe.

19. The method of claim 18, further comprising causing to send a second MU frame to the one or more devices after receiving the block acknowledgment frame from the device receiving the first subframe with the first acknowledgment policy field in the MU frame.

20. The method of claim 19, wherein the second MU frame is a MU block acknowledgment request frame comprised of one or more block acknowledgment request subframes.