Multi-access point uplink and downlink transmission

Abstract

The present invention provides a method for managing shared transmissions in a multi-AP (or BS) situation. In one method, a first access point (AP) receives a first frame from a second AP indicating the Modulation Coding Scheme (MCS) for a downlink (DL) transmission, and the first AP transmits a second frame to the second AP indicating the allocated time for a transmission opportunity (TXOP) acquired by the first AP and the time duration for the DL transmission within that time. Here, the time duration is determined based on the MCS. Alternatively, the first access point (AP) receives a first frame from the second AP indicating the DL transmission parameters for the downlink (DL) transmission, and the first AP transmits a second frame to the second AP indicating the time duration for the DL transmission. Here, the time duration is determined based on the DL transmission parameters.

Description

Technical Field

[0001] The present invention relates to wireless communication networks, and in particular, but not exclusively, to wireless communication networks implementing the IEEE (registered trademark) 802.11 standard.

Background Art

[0002] In modern wireless networks with high installation density and high demand, it is desirable to use spectrum as efficiently as possible. Many networks employ systems that "protect" subsequent transmissions, that is, systems that give an opportunity to transmit to a specific device or group of devices by requesting other devices to refrain from transmitting. Such mechanisms can take a variety of forms. In the case of IEEE 802.11 ("Wi-Fi"), this is known as a transmission opportunity (TXOP) obtained by a station before the station performs transmission. To more efficiently utilize spectrum, TXOP sharing (in the case of Wi-Fi) is employed. In addition, techniques are also employed in which a device (a station or "STA" in the case of Wi-Fi) is served by a plurality of access points ("APs") or base stations ("BSs").

Summary of Invention

Problem to be Solved by the Invention

[0003] The present invention is defined by the appended claims. The methods, devices, and computer program products defined herein enable better management of resources by two APs (for BSs) when operating in multi-AP (or BS) mode. This is achieved by sharing information regarding subsequent downlink (DL) and uplink (UL) transmissions between APs (or BSs).

Means for Solving the Problem

[0004] In one embodiment, a method is provided comprising: a first access point (AP) receiving a first frame from a second AP indicating a Modulation Coding Scheme (MCS) for downlink (DL) transmission; and the first AP transmitting a second frame to the second AP indicating the allocated time of a transmission opportunity (TXOP) acquired by the first AP and the duration of DL transmission within that allocated time, where the duration is determined based on the MCS.

[0005] In one embodiment, a method is provided which includes: receiving a first frame from a second AP by a first access point (AP) indicating downlink (DL) transmission parameters for a downlink (DL) transmission; and transmitting a second frame from the first AP to the second AP indicating a time period for the DL transmission, where the time period is determined based on the DL transmission parameters.

[0006] In one embodiment, a method is provided which includes: a first access point (AP) receiving a first frame from a second AP showing a downlink (DL) buffer status report (BSR) for a downlink (DL) transmission; and the first AP transmitting to the second AP a second frame showing the allocated transmission opportunity (TXOP) time obtained by the first AP, the identifier of the second AP, the DL transmission time period, and DL transmission parameters for the second AP for the DL transmission.

[0007] In one embodiment, a method is provided which includes: transmitting a first frame indicating a Modulation Coding Scheme (MCS) for downlink (DL) transmission to a second AP by a first access point (AP); and receiving a second frame from the second AP by the first AP indicating the allocated time of a transmission opportunity (TXOP) acquired by the second AP and the duration of DL transmission within that allocated time, where the duration is determined based on the MCS.

[0008] In one embodiment, a method is provided that includes: a first access point (AP) transmitting a first frame indicating downlink (DL) transmission parameters for a downlink (DL) transmission to a second AP; and the first AP receiving a second frame from the second AP indicating a time period for the DL transmission, where the time period is determined based on the DL transmission parameters.

[0009] In one embodiment, a method is provided which includes: a first access point (AP) receiving a first frame from a second AP showing a downlink (DL) buffer status report (BSR) for a downlink (DL) transmission; and a first AP receiving a second frame from the second AP showing the allocated transmission opportunity (TXOP) time obtained by the second AP, the identifier of the first AP, the duration of the DL transmission, and the DL transmission parameters for the first AP for the DL transmission.

[0010] In one embodiment, the method includes receiving a first frame from the second AP by the first access point (AP) indicating the amount of uplink (UL) traffic of a station (STA) associated with the second AP, and transmitting a second frame from the first AP to the second AP indicating the allocated time of a transmit opportunity (TXOP) acquired by the first AP within the allocated time, and the time period for UL transmission from the STA to the second AP based on the amount of UL traffic.

[0011] In one embodiment, the method includes receiving a first frame from the second AP by the first access point (AP) indicating the amount of uplink (UL) traffic of a station (STA) associated with the second AP, and transmitting a second frame from the first AP to the second AP indicating the time period for UL transmission from the STA to the second AP, based on the amount of UL traffic.

[0012] In one embodiment, the method includes: a first access point (AP) receiving from the second AP a first frame indicating the amount of uplink (UL) traffic for a station (STA) associated with the second AP; and the first AP transmitting to the second AP a second frame indicating the allocated time of a transmit opportunity (TXOP) acquired by the first AP within the allocated time, the identifier of the second AP, and the duration of an uplink (UL) physical layer protocol data unit (PPDU) for UL transmission from the STA to the second AP, and a modulation and coding scheme (MCS) for the UL PPDU.

[0013] In one embodiment, the first access point (AP) receives from the second access point a first frame indicating UL time resource information and UL frequency resource information for an uplink (UL) transmission from an STA associated with the second access point to the second access point, and the first access point transmits to the second access point a second frame indicating the allocated time of a transmit opportunity (TXOP) acquired by the first access point, the identifier of the second access point, and the duration of the UL physical layer protocol data unit (PPDU) for the UL transmission, determined based on the UL time resource information and the UL frequency resource information.

[0014] In one embodiment, the method includes the first access point (AP) transmitting a first frame to a second AP indicating the amount of uplink (UL) traffic of a station (STA) associated with the first AP, and the first AP receiving a second frame from the second AP indicating the time period of UL transmission from the STA to the first AP based on the allocated time of the transmission opportunity (TXOP) acquired by the second AP within the allocated time and the amount of UL traffic.

[0015] In one embodiment, the method includes the first access point (AP) transmitting a first frame to a second AP indicating the amount of uplink (UL) traffic of a station (STA) associated with a first AP, and the first AP receiving a second frame from the second AP indicating the time period of UL transmission from the STA to the first AP, based on the amount of UL traffic.

[0016] In one embodiment, the method includes: a first AP transmitting a first frame to a second AP indicating the amount of uplink (UL) traffic relating to a station (STA) associated with the first AP; and the first AP receiving a second frame from the second AP, wherein the second frame includes: an allocated transmission opportunity (TXOP) time obtained by the second AP; an identifier of the first AP; a duration of a UL physical layer protocol data unit (PPDU) used for UL transmission from the STA to the first AP within the allocated time; and a modulation coding scheme (MCS) for the UL PPDU.

[0017] In one embodiment, the method includes: a first access point (AP) transmitting a first frame to a second AP, which includes uplink (UL) time resource information for UL transmission from the STA to a first AP and UL frequency resource information for the UL transmission; and the first AP receiving a second frame from the second AP, which includes the allocated transmission opportunity (TXOP) time obtained by the second AP, the identifier of the first AP, the duration of the UL physical layer protocol data unit (PPDU) for UL transmission determined based on the UL time resource information, and the UL frequency resource information.

[0018] In one embodiment, a computer program product is provided which can be stored on a computer-readable medium and is configured to perform any of the methods described herein when executed on a processor.

[0019] In one aspect, there is provided a device configured to perform the methods described herein when implemented in an access point. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] [Figure 1] illustrates an example of a wireless communication network in which embodiments of the present specification may be implemented. [Figure 2] is a block diagram illustrating an example implementation of a Station (STA) and an Access Point (AP). [Figure 3] illustrates an example of a Medium Access Control (MAC) frame format. [Figure 4] illustrates an example of a Quality of Service (QoS) Null frame indicating buffer status information. [Figure 5] illustrates an example format of a Physical layer (PHY) Protocol Data Unit (PPDU). [Figure 6] illustrates an example of a Multi-User Request to Send (MU-RTS) trigger frame that may be used in a triggered Transmission Opportunity (TXOP) Sharing (TXS) procedure. [Figure 7] illustrates an example of a TXS procedure (mode=1). [Figure 8] illustrates an example of a TXS procedure (mode=2). [Figure 9] illustrates an example of a multi-AP network. [Figure 10] illustrates Cooperative Orthogonal Frequency Division Multiple Access (C-OFDMA). [Figure 11] is an example illustrating an inter-AP TXS procedure. [Figure 12] illustrates an example of a Physical layer Protocol Data Unit (PPDU) that may be used for a DownLink (DL) PPDU or an UpLink (UL) PPDU. [Figure 13a] illustrates an example of a problem that may occur in the inter-AP TXS procedure illustrated in FIG. 11. [Figure 13b] illustrates an example of a problem that may occur in the inter-AP TXS procedure illustrated in FIG. 11. [Figure 14a] This shows an example of an AP-to-TXS procedure according to the embodiment. [Figure 14b] This shows an example of an AP-to-TXS procedure according to the embodiment. [Figure 15a] This shows an example of an AP-to-TXS procedure according to another embodiment. [Figure 15b] This shows an example of an AP-to-TXS procedure according to another embodiment. [Figure 16a] This shows an example of an aggregated control (A control) field that can be used in the embodiment. [Figure 16b] This shows an example of an aggregated control (A control) field that can be used in the embodiment. [Figure 17a] This shows examples of information elements that can be used in the embodiment. [Figure 17b] This shows examples of information elements that can be used in the embodiment. [Figure 18] This illustrates an exemplary process according to an embodiment. [Figure 19] This shows another exemplary process according to an embodiment. [Figure 20] This shows another exemplary process according to an embodiment. [Figure 21] This shows another exemplary process according to an embodiment. [Figure 22] This shows another exemplary process according to an embodiment. [Figure 23] This shows another exemplary process according to an embodiment. [Modes for carrying out the invention]

[0021] [Examples]

[0022] In the following explanation, the same reference number refers to similar or identical elements.

[0023] This disclosure presents various embodiments as examples of how the disclosed technology may be implemented and / or how it may be carried out in environments and scenarios. It will be apparent to those skilled in the art that various modifications can be made to its form and details without departing from the scope. After reading the description, it will be apparent to those skilled in the art that alternative embodiments may be implemented. These embodiments are not limited to any of the exemplary embodiments described. Embodiments of this disclosure are described with reference to the accompanying drawings. Further embodiments can be created within the scope of the disclosure by combining limitations, features and / or elements from the examples of the disclosed embodiments. Figures highlighting functions and benefits are presented for illustrative purposes only. The disclosed architecture is sufficiently flexible and configurable that it can be used in ways other than those illustrated. For example, the actions listed in any flowchart can be rearranged or used only optionally in some embodiments.

[0024] The embodiments can be configured to operate as needed. The disclosed mechanisms can be executed when certain criteria are met, for example, in a station, access point, wireless environment, network, or a combination thereof. Examples of criteria can be based, at least in part, on wireless device or network node configuration, traffic load, initial system configuration, packet size, traffic characteristics, or a combination thereof. Various embodiments can be used when one or more criteria are met. Therefore, it is possible to implement examples of embodiments that selectively implement the disclosed protocol.

[0025] In this disclosure, “a” and “an” and similar phrases are interpreted as “at least one” and “one or more.” Similarly, terms ending in the suffix “(s)” are interpreted as “at least one” and “one or more.” In this disclosure, the term “may” is interpreted as “may, for example.” In other words, the term “may” indicates that the phrase following the term “may” is one example of a number of suitable possibilities that may or may not be adopted by one or more of the various embodiments. As used herein, the terms “contains” and “consist of” enumerate one or more components of the element being described. The term “contains” is interchangeable with “contains” and does not exclude the inclusion of components not enumerated in the element being described. In contrast, “consist of” provides a complete enumeration of one or more components of the element being described. As used herein, the term “based on” may be interpreted as “at least partially based” rather than, for example, “based only on.” As used herein, the term “and / or” represents any possible combination of the enumerated elements. For example, “A, B, and / or C” is A;B;C;A and B;A and C;B and C;or A, B and C. If A and B are sets and all elements of A are elements of B, then A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B = {STA1,STA2} are {STA1}, {STA2}, and {STA1,STA2}. The term “based on” (or equally “at least based on”) indicates that the phrase following the term “based on” is one example of a number of suitable possibilities that may or may not be adopted in one or more of the various embodiments. The term “in response” (or similarly “at least in response”) indicates that the phrase following “in response” is one example of a number of suitable possibilities that may or may not be adopted in one or more of the various embodiments.The phrase “depend” (or equivalently “at least depend”) indicates that the phrase following “depend” is one example of a number of suitable possibilities that may or may not be adopted in one or more of the various embodiments. The phrase “adopt / use” (or similarly “at least adopt / use”) indicates that the phrase following “adopt / use” is one example of a number of suitable possibilities that may or may not be adopted in one or more of the various embodiments.

[0026] The term “configured” relates to the capabilities of a device, regardless of whether the device is operational or non-operational. “Configured” may refer to specific settings within a device that affect the device’s operational characteristics, regardless of whether the device is operational or non-operational. In other words, hardware, software, firmware, registers, memory values, and / or similar can be “configured” within a device, regardless of whether the device is operational or non-operational. Terms like “control messages generated by a device” mean that control messages include parameters that can be used to set specific characteristics or implement specific actions within a device, regardless of whether the device is operational or non-operational.

[0027] In this disclosure, a parameter (also called a field or information element: IE) includes one or more information objects, and an information object may include one or more other objects. For example, if parameter (IE)N includes parameter (IE)M, parameter (IE)M includes parameter (IE)K, and parameter (IE)K includes parameter (information element)J, then for example, N includes K and N includes J. In the examples of embodiments, if one or more messages / frames include multiple parameters, it means that some of the multiple parameters are present in at least one of the one or more messages / frames, but not in each of the one or more messages / frames.

[0028] Many of the features presented are indicated as optional by the use of "may" or parentheses. For the sake of brevity and readability, this disclosure does not explicitly describe all possible variations that may be obtained by selecting from a set of optional features. This disclosure should be construed as explicitly disclosing all such variations. For example, a system described as including three optional features can be embodied in seven aspects, namely, including just one of the three possible features, any two of the three possible features, or three of the three possible features.

[0029] Many of the elements described in the disclosed embodiments can be implemented as modules. Here, a module is defined as an element that performs a defined function and has a defined interface to other elements. Modules described in this disclosure can be implemented as hardware, software combined with hardware, firmware, wetware (e.g., hardware containing biological elements), or a combination thereof, and these are operationally equivalent. For example, a module can be implemented as a software routine written in a computer language (such as C, C++, Fortran, Java, Basic, Matlab) configured to run on a hardware machine, or as a modeling / simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEW MathScript. Modules may be implemented using physical hardware incorporating discrete or programmable analog, digital, and / or quantum hardware. Examples of programmable hardware include computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), and complex-programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages ​​such as assembly language, C++, or similar languages. FPGAs, ASICs, and CPLDs are often programmed using hardware description languages ​​(HDLs) such as VHSIC (VHDL) or Verilog, which configure connections between less functional internal hardware modules on a programmable device. These technologies are used in combination to achieve the results of functional modules.

[0030] The inventors have recognized that employing TXOP sharing in situations where multiple access points (APs) are used presents certain problems. For downlink (DL), there are Buffer Status Report (BSR) frames that describe the characteristics of buffered traffic. In multi-AP TXOP sharing, the sharing AP needs to know the transmission parameters that the shared AP intends to use or needs to use for subsequent DL transmissions. The AP can know, for example, the MCS used by the STA for uplink (UL) transmissions, but not the MCS for DL ​​responses. Similarly, in the case of ULs, the sharing AP may not know the transmissions scheduled as ULs to the shared APs, potentially leading to inefficient resource allocation.

[0031] Figure 1 shows an example of a wireless communication network in which the embodiments described herein are implemented.

[0032] As shown in Figure 1, an example of a wireless communication network may include an IEEE 802.11 (WLAN) infrastructure network 102. The WLAN infrastructure network 102 may include one or more basic service sets (BSS) 110-1 and 110-2 and a distribution system (DS) 130.

[0033] BSS110-1 and 110-2 each include one access point (AP or APSTA) and a set of at least one station (STA or non-APSTA). For example, BSS110-1 includes AP104-1 and STA106-1, and BSS110-2 includes AP104-2 and STA106-2, 106-3. The AP and at least one STA in the BSS perform connection procedures to communicate with each other.

[0034] The DS130 can be configured to connect BSS110-1 and BSS110-2. In this way, the DS130 can enable Extended Service Set (ESS) 150. Within ESS 150, AP104-1 and AP104-2 can be connected via the DS130 and have the same Service Set ID (SSID).

[0035] The WLAN infrastructure network 102 can be connected to one or more external networks. For example, as shown in Figure 1, the WLAN infrastructure network 102 can be connected to another network 108 (e.g., 802.X) via a portal 140. The portal 140 can function as a bridge connecting the DS130 of the WLAN infrastructure network 102 to the other network 108.

[0036] The example wireless communication network shown in Figure 1 may further include one or more ad-hoc networks or independent BSS (IBSS). An ad-hoc network or IBSS is a network containing multiple STAs that are within each other's communication range. The multiple STAs are configured to communicate with each other directly using peer-to-peer communication (i.e., without going through APs).

[0037] For example, in Figure 1, STA106-4, STA106-5, and STA106-6 may be configured to form a first IBSS112-1. Similarly, STA106-7 and STA106-8 may be configured to form a second IBSS112-2. Since the IBSS does not include APs, it does not include a centralized management entity. Rather, the STAs within the IBSS are managed in a distributed manner. The STAs that make up the IBSS can be fixed stations or mobile stations.

[0038] An STA as a designated functional medium may include a Media Access Control (MAC) layer compliant with the IEEE 802.11 standard. The physical layer interface of the wireless medium can be used between an AP and a non-AP station (STA). An STA may be referred to using a variety of other terms, such as mobile terminal, wireless device, wireless transceiver unit (WTRU), user equipment (UE), mobile station (MS), mobile subscriber unit, or user. For example, the term "user" may be used to indicate an STA participating in uplink multi-user multiple input, multiple output (MU MIMO) and / or uplink orthogonal frequency division multiple access (OFDMA) transmissions.

[0039] A Physical Layer (PHY) Protocol Data Unit (PPDU) can be a composite structure containing a PHY preamble and payload in the form of a PHY Service Data Unit (PSDU). For example, a PSDU may contain a PHY preamble and a header and / or one or more MAC Protocol Data Units (MPDUs). The information provided in the PHY preamble can be used by the receiving device to decode the subsequent data in the PSDU. When a PPDU is transmitted over a bonded channel (a channel formed by channel bonding), the preamble fields may be duplicated and transmitted over each of the multiple component channels. A PHY preamble may contain both a legacy portion (or "legacy preamble") and a non-legacy portion (or "non-legacy preamble"). The legacy preamble can be used for applications such as packet discovery, automatic gain control, and channel estimation. The legacy preamble can also typically be used to maintain compatibility with legacy devices. The format, coding, and information provided within the non-legacy portion of the preamble are based on the specific IEEE 802.11 protocol used for transmitting the payload.

[0040] A frequency band can include one or more subbands or frequency channels. For example, a PPDU compliant with the IEEE 802.11n, 802.11ac, 802.11ax, and / or 802.11be revisions can be transmitted over the 2.4GHz, 5GHz, and / or 6GHz bands, each of which can be divided into multiple 20MHz channels. A PPDU can be transmitted over a physical channel with a minimum bandwidth of 20MHz. Channel bonding can form larger channels. For example, a PPDU can be transmitted over a physical channel with a bandwidth of 40MHz, 80MHz, 160MHz, or 3120MHz by combining multiple 20MHz channels.

[0041] Figure 2 is a block diagram showing implementation examples of STA210 and AP260. As shown in Figure 2, STA210 may include at least one processor 220, memory 230, and at least one transceiver 240. AP260 may include at least one processor 270, memory 280, and at least one transceiver 290. The processors 220 / 270 may be operably connected to the memory 230 / 280 and / or the transceivers 240 / 290.

[0042] The processor 220 / 270 can implement the functions of the PHY layer, MAC layer, and / or Logic Link Control (LLC) layer of the corresponding device (STA210 or AP260). The processor 220 / 270 may include one or more processors and / or one or more controllers. The one or more processors and / or one or more controllers may include, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a logic circuit, or a chipset.

[0043] Memory 230 / 280 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage units. Memory 230 / 280 may include one or more non-temporary computer-readable media. Memory 230 / 280 may store computer program instructions or code that can be executed by processor 220 / 270 to perform one or more of the operations / embodiments discussed in this application. Memory 230 / 280 may be implemented (or located) within or outside processor 220 / 270. Memory 230 / 280 may be operationally connected to processor 220 / 270 by various means known in the art.

[0044] The transceivers 240 / 290 can be configured to transmit and receive radio signals. In some embodiments, the transceivers 240 / 290 can implement the PHY layer of the corresponding device (STA210 or AP260). In some embodiments, the STA210 and / or AP260 may be multilink devices (MLDs), which are devices that can operate over multiple links as defined by the IEEE 802.11 standard. Therefore, the STA210 and / or AP260 may each implement multiple PHY layers. Multiple PHY layers can be implemented using one or more transceivers 240 / 290.

[0045] Target Wake Time (TWT), a feature introduced in the IEEE 802.11ah standard, allows STAs to manage activity within the BSS by scheduling STAs to operate at different times to reduce contention. TWT allows STAs to reduce the time required for STAs utilizing power management modes to recover. TWTs can be individual TWTs or broadcast TWTs. Individual TWTs are subject to a TWT agreement negotiated between STAs. Broadcast TWTs are based on a schedule set and are provided to STAs by APs.

[0046] In an individual TWT, the STA requesting TWT agreement is called the TWT requesting STA. The TWT requesting STA may be, for example, a non-AP STA. The STA responding to the request is called the TWT responding STA. The TWT responding STA may be, for example, an AP. The TWT requesting STA is allocated specific time for waking up and for exchanging frames with the TWT responding STA. The TWT requesting STA can communicate wake scheduling information to the TWT responding STA. The TWT responding STA can send a TWT value to the TWT requesting STA when TWT agreement is established between them.

[0047] When an explicit TWT is used, a TWT requesting STA may be invoked and perform a frame exchange. The TWT requesting STA may receive the next TWT information in the response from the TWT responseing STA. When an implicit TWT is used, the TWT requesting STA may calculate the next TWT by adding a fixed value to the current TWT value.

[0048] The TWT value of an implicit TWT may be periodic. A TWT request STA operating with an implicit TWT agreement can determine the start time of the next TWT SP by adding the value of the TWT wake interval associated with the TWT agreement to the start time of the current TWT service period (TWT SP). A TWT response STA may include a series of TWT SP start times corresponding to a single TWT flow identifier of the implicit TWT agreement in the target wake time field of the TWT element. The TWT element may contain the value "accept TWT" in the TWT setup command field. The start time of a TWT SP series may indicate the start time of the first TWT SP in the series. The start times of subsequent TWT SPs can be determined by adding the value of the TWT wake interval to the start time of the current TWT SP. In one embodiment, a TWT request STA that is awake for an implicit TWT SP (TWT SP) may transition to a dashed state at the earlier of the following: after the TWT SP has finished, or after receiving a frame from a TWT response STA with the EOSP field set to 1.

[0049] A TWT session can be negotiated between the AP and STA. The TWT session can configure TWT SPs for DL ​​and UL traffic between the AP and STA. Expected traffic may be limited within the negotiated SP. A TWT SP may start at a specific time. A TWT SP can continue for the duration of the SP. A TWT SP can be repeated at each SP interval.

[0050] Figure 3 shows an example of the MAC frame format 300. During operation, the STA can construct a subset of MAC frames for transmission and decode a subset of received MAC frames during verification. The specific subset of frames that the STA can construct and / or decode is determined by the capabilities supported by the STA. The STA can verify received MAC frames using the frame check sequence (FCS) contained within the frame and interpret specific fields from the MAC header of all frames.

[0051] As shown in Figure 3, a MAC frame includes a MAC header, a variable frame body, and a frame check sequence (FCS).

[0052] The MAC header includes a Frame Control field, an optional Duration / ID field, an Address field, an optional Sequence Control field, an optional QoS Control field, and an optional HT Control field.

[0053] The frame control field includes subfields for Protocol Version, Type, Subtype, To DS, From DS, More Fragments, Retry, Power Management, More Data, Protect Frame, and +HTC.

[0054] The protocol version subfield remains constant in size and placement across all revisions of the IEEE 802.11 standard. The value of the protocol version subfield is 0 for MAC frames.

[0055] The type subfield and subtype subfield identify the function of a MAC frame. There are three frame types: control, data, and management. Each frame type has several predefined subtypes. Bits within the subtype subfield can be used to indicate specific modifications to the base data frame (subtype 0). For example, in a data frame, the most significant bit (MSB) of the subtype subfield, bit 7 (B7) of the frame control field, is defined as the QoS subfield. When the QoS subfield is set to 1, it indicates a QoS subtype data frame (a data frame that includes a QoS control field in its MAC header). The second bit from the MSB of the subtype field, bit 6 (B6) of the frame control field, when set to 1 in a data subtype, indicates a data frame that does not include a frame body field.

[0056] The To DS subfield indicates whether the data frame is destined for a distribution system (DS). The From DS subfield indicates whether the data frame originates from that DS.

[0057] In all data frames or management frames that have another fragment following the MAC Service Data Unit (MSDU) or MAC Management Protocol Data Unit (MMPDU) carried by the MAC frame, the Additional Fragment subfield is set to 1. This is set to 0 in all other frames where the Additional Fragment subfield exists.

[0058] The retry subfield is set to 1 for data frames or management frames that are retransmissions of previous frames. It is set to 0 for all other frames where the retry subfield exists. The receiving STA uses this metric to assist in the process of removing duplicate frames. These rules do not apply to frames sent by the STA based on a block agreement.

[0059] The power management subfield is used to indicate the power management mode of the STA.

[0060] The MoreData subfield indicates to an STA in Power Saving (PS) mode that a bufferable unit (BU) is buffered for that STA at the AP. This MoreData subfield is valid in individually addressed data or management frames sent by the AP to the STA in PS mode. The MoreData subfield is set to 1 to indicate that at least one additional buffered BU exists for the STA.

[0061] If the frame body field contains information processed by the cryptographic encapsulation algorithm, the protected frame subfield is set to 1.

[0062] The +HTC subfield indicates that the MAC frame contains the HT control field.

[0063] The Duration / ID field in the MAC header contains various values ​​depending on the frame type and subtype, as well as the QoS capabilities of the transmitting STA. For example, in a control frame of the Power-Saving Polling (PS-Poll) subtype, the Duration / ID field carries the Association Identifier (AID) of the STA that sent the frame in 14 least significant bits (LSBs), and both most significant bits (MSBs) are set to 1. In other frames sent by the STA, the Duration / ID field contains a Duration value (in microseconds) used by the receiver to update the Network Allocation Vector (NAV). The NAV is a counter that tells the STA how long access to the shared media should be delayed.

[0064] A MAC frame format can contain up to four address fields. These fields are used to identify the Basic Service Set Identifier (BSSID), Source Address (SA), Destination Address (DA), Sender Address (TA), and Receiver Address (RA). Certain frames may omit some address fields. The use of a particular address field can be specified by its relative position (1 through 4) within the MAC header, regardless of the type of address present in that field. Specifically, the Address 1 field always identifies the recipient of the frame's destination, and the Address 2 field, if present, always identifies the sender of the frame.

[0065] The sequence control field contains two subfields: the sequence number subfield and the fragment number subfield. The sequence number subfield of a data frame indicates the sequence number of the MSDU (if not in an aggregated MSDU (A-MSDU)) or A-MSDU. The sequence number subfield of a management frame indicates the sequence number of the frame. The fragment number subfield indicates the number of each fragment in the MSDU or MMPDU. The fragment number is set to 0 for the first or only fragment of an MSDU or MMPDU and increases by 1 for each subsequent fragment of that MSDU or MMPDU. The fragment number is set to 0 for MAC protocol data units (MPDUs) containing A-MSDUs, or for MPDUs containing unfragmented MSDUs or MMPDUs. The fragment number remains constant for all retransmissions of the fragment.

[0066] The QoS control field identifies the traffic category (TC) or traffic stream (TS) to which the MAC frame belongs. The QoS control field can also indicate various other QoS-related, A-MSDU-related, and mesh-related information about the frame. This information may vary depending on the frame type, frame subtype, and transmitting STA type. The QoS control field is present in all data frames where the QoS subfield of the subtype subfield is equal to 1.

[0067] The HT control field is present in the QoS data, QoS null, and management frame, determined by the +HTC subfield of the frame control field.

[0068] The frame body field is a variable-length field containing information specific to each frame type and subtype. This may include one or more MSDUs or MMPDUs. The minimum length of a frame body is 0 octets.

[0069] The FCS field contains a 32-bit cyclic redundancy check (CRC) code. The FCS field value is calculated for all fields in the MAC header and frame body.

[0070] Figure 4 shows an example 400 of a Quality of Service (QoS) null frame indicating buffer status information. A QoS null frame refers to a QoS data frame with an empty frame body. A QoS null frame includes a QoS control field and an optional HT control field which may include a buffer status report (BSR) control subfield. A QoS null frame indicating buffer status information can be sent to the AP by the STA.

[0071] The QoS control fields may include a Traffic Identifier (TID) subfield, an Ack Policy indicator subfield, and a Queue Size subfield (or a Transmit Opportunity (TXOP) duration request subfield).

[0072] The TID subfield identifies the TC or TS of the traffic for which a TXOP is being requested, through the setting of the TXOP duration request or the queue size subfield. The encoding of the TID subfield depends on the access policy (for example, for an Extended Distributed Channel Access (EDCA) access policy to identify the user priority of a TC or TS, the allowed values ​​are 0 to 7).

[0073] The ACK policy indicator subfield, along with other information, identifies the acknowledgment policy following the delivery of the MPDU (e.g., normal ACK, implicit block ACK request, no ACK, block ACK, etc.).

[0074] The queue size subfield is an 8-bit field that indicates the amount of buffered traffic for a given TC or TS at the STA for transmission to the AP, which is identified by the receiver address of the frame containing the subfield. The queue size subfield is present in QoS null frames transmitted by the STA when bit 4 of the QoS control field is set to 1. The AP may use the information contained in the queue size subfield to determine the TXOP duration allocated to the STA or to determine the uplink (UL) resources allocated to the STA.

[0075] For frames sent by or to a non-high efficiency (non-HE) STA, the following rules may apply to the queue size value: - The queue size value is the approximate total size, rounded up to the nearest multiple of 256 octets, of all MSDUs and A-MSDUs buffered by the STA in the delivery queue used for MSDUs and A-MSDUs that have a TID value equal to the value indicated in the TID subfield of the QoS control field, and expressed in units of 256 octets. - A queue size value of 0 is used only to indicate the absence of any buffered traffic in the queue used for a given TID. - The queue size value 254 is used for all sizes greater than 64768 octets. - A queue size value of 255 is used to indicate an unspecified or unknown size.

[0076] For frames sent from HESTA to HEAP, the following rules may apply to the queue size value:

[0077] The queue size value QS is the approximate total size in octets of all MSDUs and A-MSDUs (including MSDUs or A-MSDUs contained in the same PSDU as the frame containing the queue size subfield) buffered in the STA within the delivery queue, used for MSDUs and A-MSDUs that have a TID value equal to the value indicated in the TID subfield of the QoS control field.

[0078] The queue size subfield includes the scaling factor subfield in bits B14 to B15 of the QoS control field and the unscaled value UV in bits B8 to B13 of the QoS control field. The scaling factor subfield provides the scaling factor.

[0079] STA obtains the queue size QS from the received QoS control field, which includes the scaling factor SF and the unscaled value UV, as follows:

[0080] QS= If SF is equal to 0, then 16 × UV; If SF is equal to 1, then 1024 + 256 × UV; If SF is equal to 2, then 17408 + 2048 × UV; If SF is equal to 3 and UV is less than 62, then 148480 + 32768 × UV; If SF is equal to 3 and UV is equal to 62, then >2147328; If SF is equal to 3 and UV is equal to 63, it is unspecified or unknown. The TXOP Duration Request subfield can be included in place of the queue size subfield and indicates the duration in 32 microseconds (us) that the sending STA determines is required for the next TXOP for a given TID. The TXOP Duration Request subfield is set to 0 to indicate that no TXOP has been requested for a given TID during the current service period (SP). The TXOP Duration Request subfield is set to a non-zero value to indicate a requested TXOP duration ranging from 32us to 8160us in 32us units.

[0081] The HT control field may include a BSR control subfield that can contain buffer state information used for ULMU operation. The BSR control subfield can be formed from the Access Category Index (ACI) Bitmap subfield, Delta TID subfield, ACI High subfield, Scaling Factor subfield, Queue Size High subfield, and Queue Size All subfield of the HT control field.

[0082] The ACI bitmap subfield indicates the access category for which the buffer status is reported (e.g., B0: Best Effort (AC_BE), B1: Background (AC_BK), B2: Video (AC_VI), B3: Audio (AC_VO), etc.). Each bit in the ACI bitmap subfield is set to 1 to indicate that the buffer status of the corresponding AC is included in the queue size all subfield, and to 0 otherwise. However, if the ACI bitmap subfield is 0 and the Delta TID subfield is 3, it includes the buffer status of all eight TIDs.

[0083] The Delta TID subfield, along with the value of the ACI bitmap subfield, indicates the number of TIDs for which the STA is reporting buffer status.

[0084] The ACI high subfield indicates the ACI of the AC where the BSR is shown in the queue size high subfield. The mapping from ACI to AC is defined as the mapping from ACI value 0 to AC_BE, from ACI value 1 to AC_BK, from ACI value 2 to AC_VI, and from ACI value 3 to AC_VO.

[0085] The scaling factor subfields represent the octet-level, unit SF values ​​for the queue size high subfield and queue size all subfield.

[0086] The queue size high subfield indicates the amount of buffered traffic, in SF octets, for the AC identified by the ACI high subfield, for the STA identified by the receiver address of the frame, which includes the BSR control subfield.

[0087] The queue size all subfield indicates the amount of buffered traffic in SF octets for all Acs identified by the ACI bitmap subfield, for STAs identified by the receiver address of the frame including the BSR control subfield.

[0088] The queue size values ​​in the queue size high subfield and queue size all subfield are the total size, rounded up to the nearest multiple of the SF octet, of all MSDUs and A-MSDUs (including MSDUs or A-MSDUs contained in the same PSDU as the frame containing the BSR control subfield) buffered in the STA within the delivery queue used for the MSDUs and A-MSDUs associated with the AC specified in the ACI high subfield and ACI bitmap subfield, respectively.

[0089] A queue size value of 254 in the queue size high subfield and queue size all subfield indicates that the amount of buffered traffic is greater than 254 × SF octets. A queue size value of 255 in the queue size high subfield and queue size all subfield indicates that the amount of buffered traffic is unspecified or unknown. The queue size value of a QoS data frame containing fragments may remain constant even if the amount of traffic queued changes as consecutive fragments are sent.

[0090] The MAC service provides peer entities with the ability to exchange MSDUs. To support this service, the local MAC uses an underlying PHY-level service to send MSDUs to the peer MAC entity. Such asynchronous MSDU transmission is performed on a connectionless basis.

[0091] Figure 5 shows an example of a PPDU format. As illustrated, a PPDU can include a PHY Preamble, PHY Header, PSDU, and Tail & Padding bits.

[0092] A PSDU can contain one or more MPDUs, such as a QoS data frame, MMPDU, MAC control frame, or QoS null frame. For an MPDU that transmits a QoS data frame, the MPDU's frame body can contain an MSDU or A-MSDU.

[0093] By default, MSDU transmission is best-effort based; that is, there is no guarantee that transmitted MSDUs will be successfully delivered. However, the QoS facility uses a Traffic Identifier (TID) to specify a service distinct for each MSDU.

[0094] STA can distinguish MSDU deliveries according to the designated traffic category (TC) or traffic stream (TS) of individual MSDUs. MAC sublayer entities determine the user priority (UP) of an MSDU based on the TID value provided by the MSDU. The QoS facility supports eight UP values. The UP values ​​range from 0 to 7, with 1 being the minimum value, 7 being the maximum value, and 0 forming an ordered priority between 2 and 3.

[0095] An MSDU with a specific UP is said to belong to the traffic category that has that UP. UPs can be provided directly to each MSDU as UP parameters at a Media Access Control Service access point (MACSAP). An aggregated MPDU (A-MPDU) may contain MPDUs with different TID values.

[0096] STA can deliver Buffer Status Reports (BSRs) to help APs allocate ULMU resources. STA can implicitly deliver BSRs in the QoS control field or BSR control subfield of frames sent to APs (unsolicited BSRs), or explicitly deliver BSRs in frames sent to APs in response to BSRP trigger frames (solicited BSRs).

[0097] The buffer status reported in the QoS control field includes the queue size value for a given TID. The buffer status reported in the BSR control field includes the ACI bitmap, delta TID, high priority AC, and two queue sizes.

[0098] The STA may report the buffer status to the AP in the QoS control field of the transmitted QoS null frame and QoS data frame, and in the BSR control subfield (if present) of the transmitted QoS null frame, QoS data frame, and management frame, as defined below.

[0099] The STA can report the queue size for a given TID in the queue size subfield of the QoS control field of the transmitted QoS data frame or QoS null frame. The STA can set the queue size subfield to 255 to indicate an unknown / unspecified queue size for that TID. The STA can aggregate multiple QoS data frames or QoS null frames into an A-MPDU to report the queue sizes for various TIDs.

[0100] If the AP indicates support for receiving the BSR control subfield, the STA can report the buffer status in the BSR control subfield of the transmitted frame.

[0101] High-efficiency (HE) STAs can report the queue size of the preferred AC indicated by the ACI high subfield in the queue size high subfield of the BSR control subfield. The STA can set the queue size high subfield to 255 to indicate the unknown / unspecified queue size of that AC.

[0102] The HE STA can report the queue size of ACs indicated by the ACI bitmap subfield in the queue size all subfield of the BSR control subfield. The STA can set the queue size all subfield to 255 to indicate unknown / unspecified BSRs for those ACs.

[0103] Triggered TXOP sharing (TXS) is a technique introduced in a modification of the IEEE 802.11be standard. TXS allows an AP to allocate the time length within an acquired TXOP to an STA to send one or more non-trigger-based (non-TB) PPDUs. In the case of a TXS procedure, an AP may send a Multi-User Send Request (MU-RTS) trigger frame in which the Triggered TXOP sharing mode subfield is set to a non-zero value. A MU-RTS trigger frame is a trigger frame for triggering CTS frames from multiple users. A MU-RTS trigger frame in which the Triggered TXOP sharing mode subfield is set to a non-zero value is called a MU-RTSTXS trigger (MRTT) frame.

[0104] In one example, if the triggered TXOP shared mode subfield is set to 1, the STA can send one or more non-TB PPDUs to the AP within the allocated time period. In another example, if the triggered TXOP shared mode subfield is set to 2, the STA can send one or more non-TB PPDUs to the AP or peer STA within the allocated time period. The peer STA may be an STA that includes a connection for peer-to-peer (P2P) or a connection for direct communication with the STA. In one example, the direct wireless link is established according to the Tunnel Direct Link Setup (TDLS) protocol.

[0105] Figure 6 shows an example of an MRTT frame 600 that can be used in the TXS procedure. As shown in Figure 6, an example of an MRTT frame 600 may consist of a Frame Control field, a Duration field, a Receiver Address (RA) field, a Transmitter Address (TA) field, a Common Info field, a User Info List field, a Padding field, and / or a Frame Check Sequence (FCS) field.

[0106] In one example, the common information field may be a high-efficiency (HE) variant common information field or an extremely high-throughput (EHT) variant common information field. An EHT variant common information field may consist of one or more subfields, as shown in Figure 6: Trigger Type, UL Length, many TFs, CS if required, UL bandwidth, GI, and HE / EHT-LTF Type / Triggered TXOP Sharing mode, number of HE / EHT-LTF symbols, LDPC additional symbol segment, AP transmit power, Pre-FEC padding coefficient, PE deambiguation, UL space reuse, HE / EHTP160, special user information field flags, EHT reserved, reserved, or trigger-dependent common information.

[0107] The trigger type subfield indicates that frame 600 is an MRTT frame.

[0108] GI and HE / EHT-LTF type / triggered TXOP shared mode subfields may include a triggered TXOP shared mode subfield. In one example, the triggered TXOP shared mode subfield may be set to a non-zero value (e.g., 1 or 2). In another example, the triggered TXOP shared mode subfield may be set to 1. Thus, the triggered TXOP shared mode subfield may indicate that the STA indicated by the AID12 subfield of the user information field (user information list field) may send one or more non-TB PPDUs to the AP during the time indicated by the allocation duration subfield of the user information field. In yet another example, the triggered TXOP shared mode subfield may be set to 2. Thus, the triggered TXOP shared mode subfield may indicate that the STA indicated by the AID12 subfield of the user information field (user information list field) may send one or more non-TB PPDUs to the AP or peer STA during the time indicated by the allocation duration subfield of the user information field. In one example, a peer STA may be an STA that includes a connection for P2P or a connection for direct communication with the STA.

[0109] The user information list field can contain one or more user information fields. For example, the EHT variant user information field may contain one or more of the following subfields, as shown in Figure 6: AID12, RU assignment, assignment duration, reserved, or PS160.

[0110] The AID12 subfield can indicate an Association Identifier (AID) for an STA that can use the time indicated by the Assignment Duration subfield.

[0111] The RU Allocation subfield can indicate the location and size of the RU assigned to the STA indicated by the AID12 subfield.

[0112] The allocation duration subfield may indicate the allocation time by the AP sending the MRTT frame 600. The allocation time may be part of the TXOP obtained by the AP. In one embodiment, the allocation duration subfield may indicate a first time period.

[0113] Figure 7 shows an example 700 of the TXS procedure (mode=1). As shown in Figure 7, the TXS procedure may be initiated by AP710 sending MRTT frame 720 to STA711. MRTT frame 720 may allocate a portion of the TXOP acquired by AP710 to STA711 and indicate that the TXS mode is equal to 1. Upon receiving MRTT frame 720, STA711 can use the allocated time to send one or more non-TB PPDUs to AP710. One or more non-TB PPDUs may include data frames, control frames, administration frames, or action frames.

[0114] For example, the MRTT frame 720 may include a triggered TXOP shared mode subfield indicating a TXS mode and / or a first time period corresponding to the allocated time. For example, the first time period may be set to a value of X microseconds (us).

[0115] STA711 can respond to MRTT frame 720 by sending CTS frame 721 to AP710. Subsequently, STA711 can send non-TB PPDUs 722, 724 containing one or more data frames to AP710 during the first time period indicated in MRTT frame 720. For example, AP710 may send one or more block ACK(BA) frames 723, 725 in response to one or more data frames contained in the non-TB PPDUs 722, 724 received from STA711.

[0116] Figure 8 shows an example 800 of the TXS procedure (mode=2). As shown in Figure 8, the TXS procedure may be initiated by AP810 sending an MRTT frame 820 to STA811. The MRTT frame 820 may allocate a portion of the TXOP acquired by AP810 to STA811 and indicate that the TXS mode is equal to 2. Upon receiving the MRTT frame 820, STA811 may use the allocated time to send one or more non-TB PPDUs to STA812. One or more non-TB PPDUs may include data frames, control frames, management frames, or action frames.

[0117] For example, the MRTT frame 820 may include a triggered TXOP shared mode subfield indicating a TXS mode and / or a subfield indicating a first time period corresponding to the allocated time. For example, the first time period may be set to a value of X microseconds (us).

[0118] STA811 may respond to MRTT frame 820 by sending CTS frame 821 to AP810. Subsequently, STA811 may send non-TB PPDUs 822, 824 containing one or more data frames to STA818 during the first time period indicated in MRTT frame 720. For example, STA812 may send one or more BA frames 823, 825 in response to one or more data frames contained in the non-TB PPDUs 822, 824 received from STA811.

[0119] Figure 9 shows an example of a multi-AP network 900. The example multi-AP network 900 can be a multi-AP network that conforms to the Wi-Fi Alliance standard specifications for multi-AP networks. As shown in Figure 9, the multi-AP network 900 may include a multi-AP controller 902 and multiple multi-AP groups (or multi-AP sets) 904, 906, and 908.

[0120] The multi-AP controller 902 may be a logical entity that implements the logic for controlling APs in the multi-AP network 900. The multi-AP controller 902 can receive functional information and measurements from the APs and trigger AP control commands and actions on the APs. The multi-AP controller 902 can also provide onboarding functionality to allow APs to join the multi-AP network 900 and to configure and initialize them.

[0121] Multi-AP groups 904, 906, and 908 may each contain multiple APs. APs within a multi-AP group are within each other's communication range. However, APs within a multi-AP group do not need to have the same primary channel. As used herein, the primary channel of an AP refers to the default channel that the AP uses to monitor management frames and / or transmit beacon frames. For an STA associated with an AP, the primary channel refers to the AP's primary channel, which is advertised via the AP's beacon frames.

[0122] In one approach, one of the APs in a multi-AP group can be designated as the master AP. The master AP designation can be made by the AP controller 902 or by an AP in the multi-AP group. The master AP of a multi-AP group may be fixed, or it may change over time among the APs in the multi-AP group. APs that are not the master AP in a multi-AP group are called slave APs. In another approach, the master AP may be within the communication range of all slave APs in the multi-AP group, or vice versa. A slave AP may not be within the communication range of another slave AP in the multi-AP group.

[0123] One approach is for APs within a multi-AP group to coordinate with each other, including coordinating transmissions within the multi-AP group. One form of coordination may include coordinated control for performing multi-AP transmissions within a multi-AP group. As used herein, a multi-AP transmission is a transmission event in which multiple APs (of a multi-AP group or multi-AP network) transmit simultaneously over a period of time. The period of simultaneous AP transmission may be a continuous period. Multi-AP transmissions can utilize various transmission techniques, such as coordinated OFDMA, coordinated space reuse, co-transmit and receive, coordinated beamforming, coordinated time-division multiple access (TDMA), or a combination of two or more of the aforementioned techniques.

[0124] Multi-AP group coordination can be enabled by an AP controller or the master AP of a multi-AP group. One approach is for the AP controller and / or master AP to control time and / or frequency sharing within a TXOP. For example, when one of the APs in a multi-AP group (e.g., the master AP) acquires a TXOP, the AP controller and / or master AP can control how the time / frequency resources of that TXOP are shared with the other APs in the multi-AP group. In one implementation example, the AP in the multi-AP group that acquires the TXOP becomes the master AP of the multi-AP group. The master AP can share a portion (or the entirety) of its acquired TXOP with one or more other APs in the multi-AP group.

[0125] OFDMA is a transmission technology introduced in the IEEE 802.11ax standard revision. OFDMA is a multiplex access scheme that allows multiple STAs to transmit frames simultaneously using non-overlapping (orthogonal) frequency subcarriers.

[0126] In Cooperative OFDMA (C-OFDMA), an AP (e.g., a master AP) is expected to coordinate multi-AP transmissions by multiple APs (which may or may not include the coordinating AP) by allocating each frequency of the available frequency resources (e.g., channel / subchannel) during the transmission time period to each of the multiple APs. The coordinating AP may also specify the transmission parameters for the multi-AP transmission (e.g., PPDU format, guard interval, symbol duration). The multiple APs use OFDMA during the transmission time period to simultaneously access the allocated frequency resources. Figure 10 compares C-OFDMA as multi-AP channel access with Extended Distributed Channel Access (EDCA). As shown in Figure 10, in EDCA, channel access by multiple APs (e.g., AP1, AP2) may occur during consecutive time periods (e.g., TXOP). During a particular channel access, the entire channel (e.g., 80 MHz) may be used by a single AP. In contrast, C-OFDMA allows multiple accesses by APs (multi-AP channel access) via orthogonal frequency resources to occur simultaneously during the same time period (e.g., TXOP). For example, as shown in Figure 10, an 80MHz channel is divided into four non-overlapping 20MHz channels, each assigned to one of several APs. For instance, multiple APs may simultaneously transmit to their respective associated STAs within the same time period.

[0127] In future IEEE 802.11 standard drafts, the existing TXS procedure described above is expected to be extended to APs. In such a procedure (hereinafter referred to as the AP-to-AP TXS procedure), an AP (hereinafter referred to as the sharing AP) can allocate a portion of the acquired TXOP time to one or more other APs (hereinafter referred to as the shared APs). The shared AP can use the allocated time to communicate with its associated STA and / or the sharing AP without triggering from the sharing AP. The sharing AP may or may not be part of the APs communicating within the allocated time.

[0128] Figure 11 shows Example 1100 illustrating an inter-AP TXS procedure. As shown in Figure 11, Example 1100 includes APs 1102, 1104, 1106, and 1108. In one example, APs 1102, 1104, 1106, and 1108 may form a multi-AP group, as described in Figure 9. In one example, AP 1102 may be the master AP of the multi-AP group, and APs 1104, 1106, and 1108 may be the slave APs of the multi-AP group. However, the inter-AP TXS procedure described herein is not limited to use within a multi-AP group and / or in the presence of a master AP and slave APs.

[0129] In Example 1100, AP1102 may acquire a TXOP. Subsequently, AP1102 may initiate an AP-to-AP TXS operation by sending an MRTT frame 1110 to AP1104. The MRTT frame 1110 may have a similar format to the MU-RTS trigger frame 600 described above. In one example, the MRTT frame 1110 may indicate the identifier of AP1104 (e.g., in the AID 12 subfield of the user information field in the MRTT frame 1110) and the allocated time of the TXOP 1132 (e.g., in the allocated duration subfield of the user information field). Furthermore, the MRTT frame 1110 may indicate the TXS mode (e.g., in the triggered TXOP shared mode subfield of the common information field in the MRTT frame 1110). The TXS mode indicates whether AP1104 communicates with AP1102 only during allocated time 1132 (for example, if TXS mode is set to 1), or whether AP1104 can communicate with AP1102 or another STA (for example, an associated non-APSTA or another APSTA) during allocated time 1132.

[0130] AP1104 may respond to MRTT frame 1110 by sending CTS frame 1112 to AP1102. Subsequently, for example, after a short interframe space (SIFS) following the transmission of CTS frame 1112, AP1104 may use allocated time 1132 for communication according to the TXS mode indicated in MRTT frame 1110, without a trigger from AP1102. In example 1100, the TXS mode may allow AP1104 to communicate with AP1102 or other STAs during allocated time 1132. Thus, as shown in Figure 11, AP1104 can use allocated time 1132 to send a (non-TB) downlink (DL) PPDU 1114 to an associated STA (not shown in Figure 11) and to receive an uplink (UL) PPDU 1116 from an associated STA (not shown in Figure 11).

[0131] In one example, with the remaining time of the TXOP, AP1102 can initiate another inter-AP TXS operation by sending MRTT frame 1118 to AP1106 and 1108. The MRTT frame 1118 can have a similar format to the MU-RTS trigger frame 600 described above. In one example, the MRTT frame 1118 may indicate the identifiers of AP1106 and 1108 (e.g., in the respective AID 12 subfield of the respective user information field of the MRTT frame 1118) and the TXOP allocation time 1134 (e.g., in the respective allocation duration subfield of the user information field). Furthermore, the MRTT frame 1118 may indicate the TXS mode (e.g., in the triggered TXOP shared mode subfield of the common information field of the MRTT frame 1118). The TXS mode indicates whether AP1106 and 1108 communicate with AP1102 only within the allocated time 1134 (for example, if TXS mode is set to 1), or whether AP1106 and 1108 can communicate with AP1102 or another STA (for example, an associated non-APSTA or another APSTA) within the allocated time 1134.

[0132] AP1106 and 1108 can respond to MRTT frame 1118 by sending CTS frames 1120 and 1122, respectively, to AP1102. Subsequently, for example, after SIFS following the transmission of CTS frames 1120 and 1122, AP1106 and 1108 may use allocated time 1134 for communication according to the TXS mode indicated in MRTT frame 1118, without a trigger from AP1102. In example 1100, the TXS mode may allow AP1106 and 1108 to communicate with AP1102 or another STA during allocated time 1134. Thus, as shown in Figure 11, AP1104 can use allocated time 1134 to send a (non-TB)DL PPDU 1124 to an associated STA (not shown in Figure 11) and to receive a UL PPDU 1128 from an associated STA (not shown in Figure 11). Similarly, as shown in Figure 11, AP1108 can use allocation time 1134 to send (non-TB)DL PPDU 1126 to the associated STA (not shown in Figure 11) and to receive UL PPDU 1130 from the associated STA (not shown in Figure 11).

[0133] In one example, C-OFDMA may be used for transmitting DL PPDU1124 and 1126, and UL PPDU1128 and 1130. In particular, AP1102 can allocate mutually orthogonal frequency resources to AP1106 and 1108 over an allocation time of 1134. For example, AP1102 can split an 80MHz channel into two non-overlapping 40MHz channels and allocate each channel to AP1106 and 1108, respectively. In one example, the frequency resources allocated to the APs are shown in the RU allocation subfield of the user information field (indicating the AP identifier) ​​in the MRTT frame 1118. Thus, DL PPDU1124 and UL PPDU1128 may be transmitted with RUs orthogonal to the RUs used for transmitting DL PPDU1126 and UL PPDU1130.

[0134] Figure 12 shows an exemplary PPDU1200 that can be used for downlink DL PPDU or UL PPDU. For example, PPDU1200 may be an embodiment of DL PPDU1114, 1124, or 1126, or UL PPDU1116, 1128, or 1130, as described in Figure 11. PPDU1200 may also be an ultra-high reliability (UHR) PPDU that can be used by devices compliant with the IEEE 802.11bn revision. Such devices may operate in the 2.4, 5, and 6 GHz bands. In implementations, PPDU1200 can transmit with a bandwidth of up to 320 MHz. PPDU1200 can be used by devices for both single-user (SU) and multi-user (MU) transmission. UHR may also be referred to by other names (e.g., ultra-high throughput (UHR) or ultra-high efficiency (UHE)).

[0135] As shown in Figure 12, the PPDU1200 includes a non-HT short training field (L-STF), a non-HT long training field (L-LTF), a non-high throughput (non-HT) signaling field (L-SIG), a non-HT repeating signaling field (RL-SIG), a universal signaling field (U-SIG), a UHR signaling field (UHR-SIG), a UHR short training field (UHR-STF) field, and one or more UHR long training fields (UHR-LTF), a data field, and a packet expansion (PE) field.

[0136] The L-STF is used by the PPDU1200 receiver to synchronize with the carrier frequency and frame timing of the PPDU1200 transmitter and to adjust the receiver signal gain.

[0137] L-LTF is used by the PPDU1200 receiver to estimate channel coefficients in order to equalize the channel response (such as amplitude and phase distortion) of both the signal field (L-SIG, RL-SIG, U-SIG, UHR-SIG) and the data field of the PPDU1200.

[0138] L-SIG and RL-SIG contain the parameters required to demodulate the data field. L-SIG may be equalized using channel coefficients estimated using L-LTF and demodulated to obtain the demodulation parameters of the data field.

[0139] The U-SIG ensures forward compatibility with PPDU1200. This means that future PPDUs that are backward compatible with IEEE 802.11bn will include the same U-SIG field. Therefore, devices compliant with IEEE 802.11bn will be able to understand at least part of PPDUs defined in future revisions, as long as those revisions also include the U-SIG field.

[0140] The UHR-SIG contains instructions for allocating resource units (RUs) to each STA. The receiving STA can use the indications in the UHR-SIG to locate the payload within the PPDU1200's data field.

[0141] The L-SIG, RL-SIG, U-SIG, and UHR-SIG fields can be considered as the PHY header of the PPDU1200.

[0142] The UHR-STF and one or more UHR-LTFs are used by the PPDU1200 receiver to estimate channel coefficients in order to equalize the channel response (e.g., amplitude and phase distortion) within the PPDU1200's data field.

[0143] The data field contains one or more payloads transmitted by the PPDU1200. These payloads may consist of MPDUs.

[0144] The PE field is an extension of the PPDU1200 designed to give the receiver of the PPDU1200 sufficient time to respond after receiving the PPDU1200.

[0145] Figures 13a and 13b show Example 1300, which illustrates a potential problem in the AP-to-TXS procedure shown in Figure 11. As shown in Figures 13a and 13b, Example 1300 includes APs 1102, 1106, and 1108 described above. Similar to Example 1100, AP 1102 can initiate the AP-to-TXS operation by sending an MRTT frame 1118 to APs 1106 and 1108. The MRTT frame 1118 can have a similar format to the MU-RTS trigger frame 600 described above. In one example, the MRTT frame 1118 may contain identifiers for APs 1106 and 1108 (e.g., within the respective AID 12 subfields of the respective user information fields in the MRTT frame 1118) and the TXOP allocation time 1134 (e.g., within the respective allocation duration subfields of the user information fields). Furthermore, MRTT frame 1118 may indicate TXS mode (for example, within the triggered TXOP shared mode subfield of the common information field of MRTT frame 1118). TXS mode indicates whether AP1106 and 1108 will communicate with AP1102 only within allocated time 1134 (for example, if TXS mode is set to 1), or whether AP1106 and 1108 will be able to communicate with AP1102 or another STA (for example, an associated non-APSTA or another APSTA) within allocated time 1134.

[0146] AP1106 and 1108 respond to MRTT frame 1118 by sending CTS frames 1120 and 1122, respectively, to AP1102. Subsequently, for example, after SIFS following the transmission of CTS frames 1120 and 1122, AP1106 and 1108 may use the allocated time 1134 for communication according to the TXS mode indicated in MRTT frame 1118, without a trigger from AP1102. In Example 1300, the TXS mode may allow AP1106 and 1108 to communicate with AP1102 or another STA during the allocated time 1134. Thus, as shown in Figures 13a and 13b, AP1104 can use the allocated time 1134 to send DL PPDU 1302 to an associated STA (not shown in Figure 13a) and to receive UL PPDU 1306 from an associated STA (not shown in Figure 13b). Similarly, as shown in Figure 11, AP1108 can use the allocated time 1134 to send DL PPDU 1304 to the associated STA (not shown in Figure 13a) and to receive UL PPDU 1308 from the associated STA (not shown in Figure 13b).

[0147] In one example, C-OFDMA may be used for transmitting DL PPDU1302 and 1304, and UL PPDU1128 and 1130. In particular, AP1102 can allocate mutually orthogonal frequency resources to AP1106 and 1108 over an allocation time of 1134. For example, AP1102 can split an 80MHz channel into two non-overlapping 40MHz channels and allocate each channel to AP1106 and 1108, respectively. In one example, the frequency resources allocated to the APs are shown in the RU allocation subfield of the user information field (indicating the AP identifier) ​​in the MRTT frame 1118. Thus, DL PPDU1302 and UL PPDU1306 may be transmitted with RUs orthogonal to the RUs used for transmitting DL PPDU1304 and UL PPDU1308.

[0148] Since AP1106 and AP1108 are not triggered by AP1102 during the allocated time 1134, AP1102 may indicate in the MRTT frame 1118 a first time period for downlink transmission and / or a second time period for uplink transmission within the allocated time 1134. AP1106 and 1108 can use the first time period to transmit DL PPDU 1302 and 1304, respectively. Similarly, AP1106 and 1108 can use the second time period to receive UL PPDU 1306 and 1308, respectively. The first and second time periods help to time DL PPDU 1302 and 1304, as well as UL PPDU 1306 and 1308, as shown in Figure 13b, reducing potential OFDM symbol mismatches at receivers receiving any of PPDU 1302, 1304, 1306, or 1308. OFDM symbol mismatches cause the boundaries of OFDM symbols received in the first part of the channel (e.g., the first 40 MHz) to become out of sync with the boundaries of the corresponding OFDM symbols received in the second part of the channel (e.g., the second 40 MHz). Since receivers typically receive and process the entire channel (without dedicated receiving filters for each subchannel), they may be unable to decode PPDUs that result in OFDM symbol mismatches.

[0149] Existing inter-AP TXS procedures do not define how AP1102 may set the first and / or second time periods. In one embodiment, AP1102 may set the first and / or second time periods equally, or according to a predefined configuration (e.g., fixed DL and / or UL time periods repeated within allocated time 1134). However, this may not match the actual DL / UL communication needs or requirements of AP1106 and 1108, potentially resulting in an unoptimal allocation of DL / UL resources. For example, in the case of DL transmission, as shown in Figure 13a, AP1102 may set the first time period for DL ​​transmission to significantly exceed the DL transmission needs of AP1106 and 1108. As a result, both AP1106 and 1108 may have to rely on padding to match the transmission duration of DL PPDU 1302 and 1304 to the first time period. For example, DL PDDU 1302 and 1304 may each consist of a first part (e.g., pre-UHR modulation fields such as L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG) and a second part (e.g., UHR modulation fields such as UHR-STF, UHR-LTF, data field, and PE field). For example, in the case of UL, as shown in Figure 13b, AP 1102 may set a second time period for UL transmission that significantly exceeds the UL transmission needs of AP 1106 and 1108. Therefore, each STA (not shown in Figure 13b) transmitting to AP 1106 and 1108 may have to rely on padding to match the transmission duration of DL PPDU 1306 and 1308 to the second time period. For example, UL PDDU1306 and 1308 may each consist of a first part (e.g., pre-UHR modulated fields such as L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG) and a second part (e.g., UHR-STF, UHR-LTF, data field, and PE field).AP1106 and 1108 may insert padding bits into the second portion (such as the data field) of DL PPDU1302 and 1304, respectively. This may result in suboptimal utilization of the allocated time 1134, particularly the first time period allocated for DL ​​transmission. In another example of a UL situation, the first portion may include the UHR preamble portion (e.g., pre-UHR modulation fields (L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG) and UHR-STF and UHR-LTF), and the second portion may include the data field and PE field. Each STA transmitted to AP1106 and 1108 may insert padding bits into the second portion (such as the data field) of UL PPDU1306 and 1308, respectively. This may result in suboptimal utilization of the allocated time 1134, particularly the second time period allocated for UL transmission.

[0150] As will be further described below, embodiments of the present disclosure address the above-mentioned problems that may occur in AP-to-AP TXS. In one embodiment, a first AP may send a first frame to a second AP that shows DL transmit parameters for a DL transmit. The first AP may be a shared AP and the second AP may be a sharing AP. The DL transmit may be a multi-AP transmit that is coordinated and / or initiated by the second AP. The multi-AP transmit can be performed within the allocated time of a TXOP acquired by the second AP. The DL transmit parameters may include parameters that the second AP can use to determine the DL traffic needs of the first AP for the DL transmit. In embodiments, the DL transmit parameters may include or indicate one or more of the following for the DL transmit: a modulation coding scheme (MCS), bandwidth (BW) size, resource unit (RU) size, PPDU type, or number of spatial streams. In embodiments, the DL transmit parameters may include or indicate DL time resource allocation information and / or DL ​​frequency resource allocation information for the DL transmit. The DL transmit may include a DL PPDU. In another aspect, the first AP may send a Buffer Status Report (BSR) to the second AP indicating the amount of DL traffic being buffered at the first AP. In one embodiment, the first frame may include the BSR. The second AP may send a second frame to the first AP indicating a time period for DL ​​transmission determined based on DL transmission parameters. The second AP may send DL PPDUs for DL ​​transmission during the time period.

[0151] In another aspect, the first AP may send a first frame to the second AP indicating the amount of UL traffic for the STA associated with the first AP. The amount of UL traffic for the STA may correspond to the amount of traffic buffered by the STA for uplink transmission to the first AP. The first AP may be a shared AP, and the second AP may be a sharing AP. The first AP may receive a second frame from the second AP indicating a time period based on the amount of UL traffic for a UL transmission from the STA to the first AP. The UL transmission may be part of a C-OFDMA UL transmission. A C-OFDMA UL transmission may consist of that UL transmission and further UL transmissions. Further UL transmissions may be from another STA to the second or third AP. C-OFDMA UL transmissions may be performed within the allocated time of a TXOP obtained by the second AP. In one embodiment, the first frame may further indicate the amount of UL traffic for further STAs associated with the first AP. In another embodiment, the first frame may further indicate UL transmission parameters for the UL transmission. The time duration may further be based on UL transmission parameters. The UL transmission parameters may include, or represent, one or more of the following for UL transmission: modulation coding scheme (MCS), bandwidth (BW) size, resource unit (RU) size, PPDU type, or number of spatial streams. In another embodiment, the first AP may receive from the second AP a second frame indicating the duration of the UL PPDU for UL transmission from the STA to the first AP and the transmission parameters of the UL PPDU. In yet another embodiment, the first AP may transmit a first frame to the second AP, which indicates UL time resource information and / or UL frequency resource information for UL transmission from the STA to the first AP. The first AP receives from the second AP a second frame indicating the duration of the UL PPDU for UL transmission, determined based on the UL time resource information and / or UL frequency resource information.

[0152] Further aspects and details of the embodiments are presented in the following example embodiments.

[0153] Figures 14a and 14b show an example 1400 of an AP-to-TXS procedure according to an embodiment. As shown in Figure 14a, example 1400 includes APs 1402, 1404, and 1406. In one example, APs 1402, 1404, and 1406 may form a multi-AP group, as described in Figure 9. In one example, AP 1402 may be the sharing AP (i.e., master AP) of the multi-AP group, and APs 1404 and 1406 may be the shared APs (i.e., slave APs) of the multi-AP group. However, the AP-to-TXS procedures described herein are not limited to use in a multi-AP group and / or when a sharing AP (i.e., master AP) and a shared AP (i.e., slave AP) are present.

[0154] As shown in Figure 14a, Example 1400 may begin with AP1404 sending frame 1408 to AP1402. In one embodiment, frame 1408 may contain DL transmission parameters for DL ​​transmission. DL transmission can be a multi-AP transmission. Multi-AP transmission may be performed within the allocated time of a TXOP acquired by AP1402. Multi-AP transmission may be performed as part of an AP-to-AP TXS procedure as described above. Multi-AP transmission may or may not include AP1402. Multi-AP transmission may be a coordinated DL PPDU transmission by AP1402, as well as one or more of AP1404 and AP1406. Alternatively, as shown in Figure 14, multi-AP transmission may be a coordinated DL PPDU transmission by AP1404 and 1406. Cooperative DL PPDU transmission may consist of C-OFDMA transmission, cooperative space reuse (C-SR) transmission, cooperative beamforming (C-BF), or cooperative joint transmission. Frame 1502 may include a buffer status report polling (BSRP) trigger frame, a base trigger frame, a polling frame, or a request frame. As shown in Figure 14b, in embodiments related to a UL scenario, frame 1408 may indicate the amount of UL traffic for a first STA (not shown in Figure 14) associated with AP1404. The amount of UL traffic for the first STA may correspond to the amount of traffic buffered at the first STA for uplink transmissions to AP1404. In one embodiment, the amount of UL traffic for the first STA may correspond to the uplink queue size at the first STA. The uplink queue size may be for one or more TIDs. In another embodiment, frame 1408 may further indicate the amount of UL traffic for another STA (not shown in Figure 14) associated with AP140.

[0155] DL transmit parameters may include parameters that AP1402 can use to determine AP1404's DL traffic needs for DL ​​transmission. In one embodiment, DL transmit parameters may include or indicate one or more of the following for DL ​​transmission: MCS, bandwidth (BW) size, RU size, PPDU type, or spatial stream count (Nss). In one embodiment, DL transmit parameters may include or indicate DL time resource allocation information or DL ​​frequency resource allocation information for said DL transmission. In embodiments relating to UL transmission, frame 1408 may alternatively or additionally indicate UL transmit parameters for a UL transmission from a first STA to AP1404. A UL transmission may be part of a coordinated UL transmission. A coordinated UL transmission may include a UL transmission from a first STA to AP1404 and further UL transmissions. Further UL transmissions may be from another STA (not shown in Figure 14) to AP1402 or AP1406. Cooperative AP transmissions may be performed within the allocated time of the TXOP acquired by AP1402. Cooperative AP transmissions may be performed in the context of the inter-AP TXS procedure as described above. Cooperative UL transmissions may or may not include AP1402. Cooperative UL PPDU transmissions may include C-OFDMA transmissions, cooperative space reuse (C-SR) transmissions, cooperative beamforming (C-BF) transmissions, or cooperative joint transmissions.

[0156] In one embodiment, if the DL (or optionally UL) transmission parameters include or indicate an MCS, frame 1408 may include an MCS index. In another embodiment, in addition to the MCS index, frame 1408 may indicate the PPDU type or format (e.g., HT, HE, VHT, EHT, UHR, etc.). In a further embodiment, frame 1408 may further indicate the requested bandwidth (e.g., 20 MHz, 40 MHz, etc.) for DL ​​or UL transmission. In one embodiment, frame 1408 may indicate multiple MCS indices for multiple bandwidth values ​​for DL ​​or UL transmission.

[0157] In one embodiment, if the DL or UL transmission parameters include or indicate DL time resource allocation information, frame 1408 may include a duration for DL ​​or UL transmission. The duration may be a requested duration for DL ​​or UL transmission.

[0158] In one embodiment, if the DL or UL transmission parameters include or indicate DL or UL frequency resource allocation information, frame 1408 may include the RU size or type for the DL or UL transmission (e.g., 26-toneRU, 52-toneRU, etc.). The RU size or type may be a requested RU size or type for the DL or UL transmission.

[0159] In one embodiment, the DL or UL transmission parameters may be determined by AP1404. The DL transmission parameters may be selected by AP1404 from a plurality of DL or UL transmission parameters. The plurality of DL transmission parameters may be pre-configured in AP1404. For example, the DL or UL transmission parameters may be proposed by AP1404 for DL ​​or UL transmission. For example, the DL or UL transmission parameters may be preferred DL or UL transmission parameters for DL ​​or UL transmission.

[0160] In one embodiment, frame 1408 may be, for example, a QoS data frame or a QoS null frame, or an action frame. If frame 1408 is a QoS data frame or a QoS null frame, it may include an aggregate control (A-control) field containing DL transmission parameters, as shown, for example, in Figure 16a. If frame 1408 is an action frame, the action frame may include an information element (i.e., an information field) containing DL transmission parameters. In a UL scenario (see Figure 16b), the aggregate control (A-Control) field may include UL traffic volume and / or UL transmission parameters. If frame 1408 is an action frame, it may include an information element (or information field) containing UL traffic volume and / or UL transmission parameters. Such information elements are shown, for example, in Figures 17a(DL) and 17b(UL).

[0161] In one embodiment, frame 1408 may further include a DL or UL buffer status report (BSR). The DL or UL BSR may indicate the amount of buffered traffic for DL ​​transmissions at AP1404 (in the case of DL) or for UL transmissions at the first STA (in the case of UL). The DL BSR can indicate the amount of buffered traffic (e.g., in the queue size subfield) as described with reference to Figure 4 above. In an implementation, the buffered traffic may correspond to all traffic buffered for DL ​​transmissions at AP1404 (in the case of DL) or the first STA (in the case of UL). In another embodiment, the buffered traffic may, in the case of DL, correspond to traffic buffered for DL ​​transmissions to a specific STA that AP1404 intends to service by DL transmissions. Furthermore, or alternatively, the buffered traffic may correspond to traffic buffered for DL ​​or UL transmissions to a specific access category (AC) or TID.

[0162] In one example, Example 1400 may also include AP1406 sending frame 1410 to AP1402. Frame 1410 may be sent before or after frame 1408. In one embodiment, in the case of DL, frame 1410 may indicate DL transmission parameters for DL ​​transmission. In one embodiment, in the case of UL, frame 1410 may indicate the amount of UL traffic to a second STA (not shown in Figure 14) associated with AP1406. Frame 1410 is similar to frame 1408. Similar descriptions for frame 1408 also apply to frame 1410.

[0163] Subsequently, AP1402 may initiate inter-AP TXS operation by acquiring a TXOP and sending an MRTT frame 1412 to AP1404 and 1406. The MRTT frame 1412 can have a similar format to the MU-RTS trigger frame 600 described above. For example, the MRTT frame 1412 may indicate the identifiers of AP1404 and 1406 (e.g., in the respective AID subfield of the respective user information field of the MRTT frame 1412) and the allocated time of the TXOP (e.g., in the respective allocation duration subfield of the user information field). Furthermore, the MRTT frame 1412 may indicate the TXS mode (e.g., in the triggered TXOP shared mode subfield of the common information field of the MRTT frame 1412). The TXS mode indicates whether AP1404 and 1406 communicate with AP1402 only within the allocated time 1414 (for example, if TXS mode is set to 1), or whether AP1404 and 1406 can communicate with AP1402 or another STA (for example, an associated non-APSTA or another APSTA) within the allocated time 1414.

[0164] In one embodiment, in the case of DL, the MRTT frame 1412 may further indicate a time period 1428 for DL ​​transmission within the allocated time 1414. DL transmission may be a multi-AP transmission. Multi-AP transmission may be performed within the allocated time of the TXOP acquired by AP 1402. Multi-AP transmission may be performed as part of the inter-AP TXS procedure as described above. Multi-AP transmission may or may not include AP 1402. Multi-AP transmission may be a coordinated DL PPDU transmission by AP 1402 and one or more of AP 1404 and AP 1406. Alternatively, as shown in Figure 14, multi-AP transmission may be a coordinated DL PPDU transmission by AP 1404 and 1406. Coordinated DL PPDU transmission may consist of C-OFDMA transmission, coordinated space reuse (C-SR) transmission, coordinated beamforming (C-BF), or coordinated joint transmission. Frame 1502 may include a Buffer Status Report Polling (BSRP) trigger frame, a basic trigger frame, a polling frame, or a request frame. In one embodiment, the DL transmission may be performed in response to frames 1408 and 1410 from APs 1404 and 1406, respectively, which notify the DL transmission parameters for the DL transmission.

[0165] In the UL embodiment, the MRTT frame 1412 may further indicate a time period 1428 for UL transmission within the allocated time 1414. The UL transmission may be part of a coordinated UL transmission. A coordinated UL transmission may include a UL transmission from a first STA to AP 1404 and further UL transmissions. Further UL transmissions may be from another STA to AP 1402 or AP 1406. The coordinated AP transmission may be performed within the allocated time of the TXOP acquired by AP 1402. The coordinated AP transmission may be performed in the context of the AP-to-TXS procedure as described above. The coordinated UL transmission may or may not include AP 1402. The coordinated UL PPDU transmission may include a C-OFDMA transmission, a coordinated space reuse (C-SR) transmission, a coordinated beamforming (C-BF) transmission, or a coordinated joint transmission. In one embodiment, UL transmission may be performed in response to frames 1408 and 1410 from AP1404 and 1406, respectively, which notify the amount of UL traffic and / or UL transmission parameters for UL transmission.

[0166] In one embodiment, AP1402 may determine the time period 1428 based on the DL or UL transmission parameters shown in frame 1408 and / or the DL or UL transmission parameters shown in frame 1410.

[0167] In one embodiment, AP1402 may determine a first data rate for DL ​​or UL transmission for AP1404 based on the DL or UL transmission parameters shown in frame 1408. In one embodiment, AP1402 may further determine a second data rate for DL ​​transmission for AP1406 based on the DL or UL transmission parameters shown in frame 1410. For example, AP1402 may determine the first or second data rate based solely on the MCS index shown in frame 1408 or 1410, or based on a combination of the MCS index and the PPDU type or format, bandwidth value, and / or number of spatial streams. For example, the first or second data rate may be determined using the MCS table provided in the IEEE 802.11 standard.

[0168] In one embodiment, AP1402 can determine a first time period using a first data rate and traffic volume (e.g., shown in frame 1408). For DL ​​transmissions, this may be the amount of traffic buffered for transmission at AP1404. In one embodiment, AP1402 can determine a second duration using a second data rate and the amount of traffic buffered (e.g., shown in frame 1410) for DL ​​transmission at AP1406. In one embodiment, AP1402 can select the longer of the first and second durations as the time period 1428. Thus, it is ensured that the time period 1428 is long enough to accommodate the DL or UL traffic requested by or shown by both AP1404 and 1406. In another embodiment, the time period 1428 may be subject to a maximum PPDU duration; that is, the time period 1428 cannot exceed the maximum PPDU duration. In another embodiment, the APs (AP1420 for DL ​​and AP1402 for UL) can select the shorter of the first and second durations as the time period 1428. This allows the time period 1428 to be fully utilized for DL ​​and UL transmission of data traffic by or to AP1404 and 1406. In other words, in the case of DL, neither AP1404 nor 1406 may need to add padding to their respective DL PPDUs to align the transmission period with the time period 1428. Similarly, in the case of UL, neither UL PPDUs 1420 nor 1422 may need to include padding bits to align the transmission period with the time period 1428.

[0169] In one embodiment, the MRTT frame 1412 may include the duration of a time period 1428. In one embodiment, the start time of the time period 1428 may be determined based on the MRTT frame 1412. For example, the start time of the time period 1428 may be the time when the MRTT frame 1412 is received plus the 2SIFS and CTS frame transmission time (and optionally, the length of the time period for DL ​​transmission of the allocated time 1414). The end time of the time period 1428 can be determined based on the start time and the specified duration.

[0170] In another embodiment, the MRTT frame 1412 may include the start and end times of a time period 1428, the start time and duration of a time period 1428, or the duration and end time of a time period 1428. In such an embodiment, the start time of the time period 1428 may not be based on the MRTT frame 1412.

[0171] In another embodiment, the MRTT frame 1412 may indicate a time period 1428 as a segment of the allocated time 1414. For example, the MRTT frame 1412 may indicate that the time period 1428 corresponds to the first or second half of the allocated time 1414, or the first or last X microseconds of the allocated time 1414, etc.

[0172] In another embodiment, the MRTT frame 1412 may indicate the time period 1428 by indicating the number of OFDM symbols (of a predetermined duration) transmitted during the time period 1428.

[0173] In other embodiments, AP1402 may initiate inter-AP TXS operation by transmitting a frame other than an MRTT frame. For example, AP1402 may use a multi-AP trigger frame to initiate inter-AP TXS operation. The multi-AP trigger frame may contain or show the same information as described above as being included in or shown in MRTT frame 1412. AP1404 and 1406 may or may not respond to or acknowledge the multi-AP trigger frame from AP1402.

[0174] As shown in Figure 14a (for DL), AP1404 and 1406 can respond to MRTT frame 1412 by sending CTS frames 1416 and 1418 to AP1402, respectively. Subsequently, for example, after SIFS following the transmission of CTS frames 1416 and 1418, AP1404 and 1406 may use the allocated time 1414 for communication, without a trigger from AP1402, according to the TXS mode indicated in MRTT frame 1412 and taking into account the time period 1428. In example 1400, the TXS mode may allow AP1404 and 1406 to communicate with AP1402 or another STA during the allocated time 1414. Thus, as shown in Figure 14, AP1404 can use the time period 1428 of allocated time 1414 to send the (non-TB)DL PPDU 1420 to the relevant STA (not shown in Figure 14a). AP1404 can use the DL transmit parameters shown in frame 1408 when transmitting DL PPDU 1420. DL PPDU 1420 includes a transmit duration equal to time period 1428. Similarly, AP1406 can use time period 1428 to transmit (non-TB) DL PPDU 1422 to the associated STA (not shown in Figure 14a). AP1404 can use the DL transmit parameters shown in frame 1410 when transmitting DL PPDU 1422. DL PPDU 1422 includes a transmit duration equal to time period 1428. In Example 1400, AP1406 can insert padding bits into the payload of DL PPDU 1422 so that the transmit duration of PPDU 1422 is equal to time period 1428. However, if time period 1428 is set by AP1402 as described above, AP1404 does not need to insert any padding bits into DL PPDU 1420 and can use time period 1428 to transmit buffered DL data throughout. Therefore, the utilization of allocated time 1414, and especially allocated time period 1428 for DL ​​transmission, is increased.

[0175] As shown in Figure 14b, in the case of UL, AP1404 and 1406 can respond to MRTT frame 1412 by sending CTS frames 1416 and 1418 to AP1402, respectively. Subsequently, for example, after SIFS following the transmission of CTS frames 1416 and 1418, AP1404 and 1406 may use the allocated time 1414 for communication, without a trigger from AP1402, according to the TXS mode indicated in MRTT frame 1412 and taking into account the time period 1428. In Example 1400, the TXS mode may allow AP1404 and 1406 to communicate with AP1402 or another STA during the allocated time 1414. Thus, in one example, as shown in Figure 14, AP1404 can use the first portion of the allocated time 1414 to send a (non-TB)DL PPDU 1420 to the relevant STA (not shown in Figure 14b). Similarly, AP1406 can use the first portion of allocated time 1414 to send a (non-TB)DL PPDU 1422 to an associated STA (not shown in Figure 14). AP1404 can then use the first time period 1428 to receive a UL PPDU 1424 from a first STA associated with AP1404 (not shown in Figure 14b). Similarly, AP1406 can use the first time period 1428 to receive a UL PPDU 1426 from a second STA associated with AP1406 (not shown in Figure 14b). In one example, AP1404 can send a frame to the first STA in the first portion of allocated time 1414 to prompt or trigger a UL PPDU 1424. In one example, AP1406 can send a frame to the second STA in the first portion of allocated time 1414 to prompt or trigger a UL PPDU 1426. In another example, the start time of the first time period 1428 may coincide with the start time of the allocated time 1414.Therefore, the first and second STAs, which do not necessarily take place before the UL transmission, may be triggered by MRTT frame 1412 to transmit, for example, UL PPDU 1424 and 1426, respectively.

[0176] In an example related to DL, AP1404 may use the remaining duration of the allocated time 1414, following any instructions in MRTT frame 1412, to receive UL PPDU 1424 from the associated STA (not shown in Figure 14). In one example, AP1406 may use the remaining duration of the allocated time 1414, following any instructions in MRTT frame 1412, to receive UL PPDU 1426 from the associated STA (not shown in Figure 14).

[0177] In embodiments relating to UL, the first STA can use the UL transmission parameters shown in frame 1408 when transmitting UL PPDU 1424. UL PPDU 1424 includes a transmission duration equal to time period 1428. In one embodiment, the second STA can use the UL transmission parameters shown in frame 1410 when transmitting UL PPDU 1426. UL PPDU 1426 includes a transmission duration equal to time period 1428. In Example 1400, the second STA can insert padding bits into the payload of UL PPDU 1426 so that the transmission duration of PPDU 1426 is equal to time period 1428. However, if time period 1428 is set by the first STA as described above, AP 1404 does not need to insert any padding bits into UL PPDU 1424 and can use the entire time period 1428 to transmit the buffered UL data to AP 1404. Therefore, the utilization rate of allocated time 1414, and especially allocated time period 1428 for UL transmission, increases.

[0178] In one example, C-OFDMA may be used for transmitting DL PPDUs 1420 and 1422, and UL PPDUs 1424 and 1426. Specifically, AP 1402 can allocate mutually orthogonal frequency resources to APs 1404 and 1406 over an allocation time of 1414. For example, AP 1402 can split an 80MHz channel into two non-overlapping 40MHz channels and allocate each channel to APs 1404 and 1406, respectively. In one example, the frequency resources allocated to the APs are shown in the RU allocation subfield of the user information field (which indicates the AP identifier) ​​in the MRTT frame 1412. Thus, DL PPDUs 1420 and UL PPDUs 1424 may be transmitted with RUs orthogonal to the RUs used for transmitting DL PPDUs 1422 and UL PPDUs 1426.

[0179] In another embodiment (not shown in Figure 14a), AP1404 may include the DL BSR in frame 1408, but may not include the DL transmit parameters in frame 1408. Similarly, AP1406 may include the DL BSR in frame 1410, but may not include the DL transmit parameters in frame 1410. AP1402 may determine a time period 1428 for DL ​​transmission based on one or both of the DL BSRs received from AP1404 and 1406. In one embodiment, AP1402 may further determine DL transmit parameters for DL ​​transmission for one or more of AP1404 and 1406, based on one or both of the DL BSRs received from AP1404 and 1406. In one embodiment, the DL transmit parameters may include the number of MCS, DL time resource allocation information, DL frequency resource allocation information, or spatial streams for DL ​​transmission. AP1402 may include the determined DL transmit parameters in MRTT frame 1412. By selecting time period 1428 and DL transmission parameters based on the DL BSR, AP1402 can ensure that at least one of AP1404 and 1406 fully utilizes time period 1428 for DL ​​transmission of data traffic (i.e., without padding).

[0180] In another embodiment, in the case of UL (not shown in Figure 14b), AP1404 may include the amount of UL traffic for the first STA in frame 1408, but may not include the UL transmit parameters for the UL transmission from the first STA to AP1404 in frame 1408. Similarly, AP1406 may include the amount of UL traffic for the second STA in frame 1410, but may not include the UL transmit parameters for the UL transmission from the second STA to AP1406 in frame 1410. AP1402 may determine the time period 1428 based on one or both of the amount of UL traffic for the first STA and the amount of UL traffic for the second STA. In one example, AP1402 may further determine the UL transmit parameters for the UL transmission to AP1404 and / or the UL transmission to AP1406 based on one or more of the amount of UL traffic for the first STA and the amount of UL traffic for the second STA. In one embodiment, the UL transmit parameters may include the MCS, UL time resource allocation information, UL frequency resource allocation information, or the number of spatial streams for UL transmission. AP1402 can include the determined UL transmit parameters in the MRTT frame 1412. By selecting the time period 1428 and the UL transmit parameters based on one or more of the UL traffic volume for the first STA and the UL traffic volume for the second STA, AP1402 can ensure that at least one of the first and second STAs fully utilizes the time period 1428 for UL transmission of data traffic (i.e., without padding).

[0181] Figures 15a and 15b show an example 1500 of an AP-to-TXS procedure according to another embodiment. As shown in Figures 15 and 15b, example 1500 also includes APs 1402, 1404, and 1406, which were described above with reference to Figure 14. In one example, APs 1402, 1404, and 1406 may form a multi-AP group, as described in Figure 9. In one example, AP 1402 may be the sharing AP (i.e., master AP) of the multi-AP group, and APs 1404 and 1406 may be the shared APs (i.e., slave APs) of the multi-AP group. However, the AP-to-TXS procedures described herein are not limited to use in a multi-AP group and / or in the presence of a sharing AP (i.e., master AP) and a shared AP (i.e., slave AP).

[0182] As shown in Figure 15a, Example 1500 (for DL) begins with AP1402 sending frame 1502 to AP1404 and / or 1406. In one embodiment, frame 1502 requests DL BSRs from AP1404 and / or 1406 for DL ​​transmission. DL transmission can be a multi-AP transmission. Multi-AP transmission may be performed within the allocated time of the TXOP acquired by AP1402. Multi-AP transmission may be performed as part of the inter-AP TXS procedure as described above. Multi-AP transmission may or may not include AP1402. Multi-AP transmission may be a coordinated DL PPDU transmission by AP1402, as well as one or more of AP1404 and AP1406. Alternatively, as shown in Figure 15, multi-AP transmission may be a coordinated DL PPDU transmission by AP1404 and 1406. Cooperative DL PPDU transmission may consist of C-OFDMA transmission, cooperative space reuse (C-SR) transmission, cooperative beamforming (C-BF), or cooperative joint transmission. Frame 1502 may include a buffer status report polling (BSRP) trigger frame, a base trigger frame, a polling frame, or a request frame.

[0183] As shown in Figure 15b, Example 1500 (for UL) begins with AP1402 sending frame 1502 to AP1404 and / or 1406. In one embodiment, frame 1502 requests an ULBSR from AP1404 and / or 1406 for a cooperative UL transmission. The cooperative UL transmission may consist of a UL transmission from a first STA (not shown in Figure 15) to AP1404 and a further UL transmission. The further UL transmission may be from another STA (not shown in Figure 15) to AP1402 or AP1406. The cooperative AP transmission may be performed within the allocated time of the TXOP acquired by AP1402. The cooperative AP transmission may be performed in the context of the inter-AP TXS procedure as described above. The cooperative UL transmission may or may not include AP1402. Cooperative UL PPDU transmission may include C-OFDMA transmission, cooperative space reuse (C-SR) transmission, cooperative beamforming (C-BF) transmission, or cooperative joint transmission. Frame 1502 may include a buffer status report polling (BSRP) trigger frame, a base trigger frame, a polling frame, or a request frame.

[0184] In embodiments relating to DL, AP1404 can respond to frame 1502 by sending frame 1504 to AP1402. In one embodiment, frame 1504 includes a DL BSR for DL ​​transmission. The DL BSR may indicate the amount of buffered traffic for DL ​​transmission at AP1404. The DL BSR can indicate the amount of buffered traffic (e.g., in the queue size subfield) as described with reference to Figure 4 above. In an implementation, the buffered traffic may correspond to all traffic buffered at AP1404 for DL ​​transmission. In another embodiment, the buffered traffic may correspond to traffic buffered for DL ​​transmission to a particular STA that AP1404 intends to service by DL transmission. Furthermore, or alternatively, the buffered traffic may correspond to traffic buffered for DL ​​transmission to a particular access category (AC) or TID.

[0185] In embodiments relating to DL, frame 1504 may further indicate DL transmission parameters for DL ​​transmission. The DL transmission parameters may include parameters that AP 1402 can use to determine AP 1404's DL traffic needs for DL ​​transmission. In one embodiment, the DL transmission parameters may include or indicate one or more of the following for DL ​​transmission: MCS, bandwidth (BW) size, RU, PPDU type, or spatial stream count (Nss). In one embodiment, the DL transmission parameters may include or indicate DL time resource allocation information or DL ​​frequency resource allocation information for the DL transmission.

[0186] In embodiments relating to UL, AP1404 can respond to frame 1502 by sending frame 1504 to AP1402. In one embodiment, frame 1504 may indicate the amount of UL traffic for a first STA (not shown in Figure 15) associated with AP1404. The amount of UL traffic for the first STA may correspond to the amount of traffic buffered at the first STA for uplink transmission to AP1404. In one embodiment, the amount of UL traffic for the first STA may correspond to the uplink queue size at the first STA. The uplink queue size may be for one or more TIDs. In another embodiment, frame 1504 may further indicate the amount of UL traffic for another STA (not shown in Figure 15) associated with AP1404.

[0187] In embodiments relating to UL, frame 1504 may, alternatively or additionally, indicate UL transmission parameters for UL transmission from the first STA to AP1404. UL transmission may be part of a coordinated UL transmission.

[0188] In embodiments related to DL, if the DL transmission parameters include or indicate an MCS, frame 1504 may include an MCS index. In another embodiment, frame 1504 may indicate a PPDU type or format (e.g., HT, HE, VHT, EHT, UHR, etc.) in addition to the MCS index. In a further embodiment, frame 1504 may further indicate the requested bandwidth for DL ​​transmission (e.g., 20 MHz, 40 MHz, etc.). In one embodiment, frame 1504 may indicate multiple MCS indices for multiple bandwidth values ​​for DL ​​transmission.

[0189] In embodiments relating to UL, if the UL transmission parameters include or indicate an MCS, frame 1504 may include an MCS index. In another embodiment, frame 1504 may indicate a PPDU type or format (e.g., HT, HE, VHT, EHT, UHR, etc.) in addition to the MCS index. In a further embodiment, frame 1504 may further indicate the requested bandwidth for UL transmission (e.g., 20 MHz, 40 MHz, etc.). In one embodiment, frame 1408 may indicate multiple MCS indices for multiple bandwidth values ​​for UL transmission.

[0190] In one embodiment, if the DL or UL transmission parameters include or indicate DL or UL time resource allocation information, frame 1504 may include a duration for DL ​​or UL transmission. The duration may be a requested duration for DL ​​or UL transmission.

[0191] In one embodiment, if the DL or UL transmit parameters include or indicate DL frequency resource allocation information, frame 1504 may include the RU size or type for DL ​​or UL transmit (e.g., 26-toneRU, 52-toneRU, etc.). The RU size or type may be a requested RU size or type for DL ​​or UL transmit.

[0192] In one embodiment, the DL or UL transmission parameters may be determined by AP1404. The DL or UL transmission parameters may be selected by AP1404 from a plurality of DL or UL transmission parameters. The plurality of DL or UL transmission parameters may be pre-configured in AP1404. For example, the DL or UL transmission parameters may be proposed by AP1404 for DL ​​or UL transmission. For example, the DL or UL transmission parameters may be preferred DL or UL transmission parameters for DL ​​or UL transmission.

[0193] In one embodiment, in the case of DL, frame 1504 may be, for example, a QoS data frame, a QoS null frame, or an action frame. If frame 1504 is a QoS data frame or a QoS null frame, it may include an aggregate control (A control) field containing DL transmission parameters, as shown, for example, in Figure 16a. If frame 1504 is an action frame, the action frame may include an information element (i.e., an information field) containing DL transmission parameters. The information element is shown, for example, in Figure 17a.

[0194] In the case of UL, in one embodiment, frame 1504 may be, for example, a QoS data frame or a QoS null frame, or an action frame. If frame 1504 is a QoS data frame or a QoS null frame, it may include an aggregate control (A control) field containing the amount of UL traffic and / or UL transmit parameters, as shown, for example, in Figure 16b. If frame 1504 is an action frame, the action frame may include an information element (i.e., an information field) containing the amount of UL traffic and / or UL transmit parameters. The information element is shown, for example, in Figure 17b.

[0195] In embodiments relating to UL, frame 1504 may include an ULBSR. The ULBSR may indicate the amount of UL traffic at the first STA. The ULBSR can indicate the amount of buffered traffic (e.g., in the queue size subfield), as described with reference to Figure 4 above. In an implementation, the buffered traffic may correspond to all traffic buffered for UL transmission at the first STA. In another embodiment, the buffered traffic may correspond to traffic buffered for UL transmission for a specific access category (AC) or TID.

[0196] In one example, in the case of DL, Example 1500 may also include AP1406 sending frame 1506 to AP1402. Frame 1506 may be sent before or after frame 1504. In one embodiment, frame 1506 may show DL transmission parameters for DL ​​transmission. Frame 1506 is similar to frame 1504. The same description as for frame 1504 also applies to frame 1506.

[0197] In one example, in the case of UL, Example 1500 may also include AP1406 sending frame 1506 to AP1402. Frame 1506 may be sent before or after frame 1504. In one embodiment, frame 1506 may indicate the amount of UL traffic for a second STA (not shown in Figure 14) associated with AP1406. Frame 1506 is similar to frame 1504. The same description of frame 1506 also applies to frame 1504.

[0198] Subsequently, AP1402 may initiate inter-AP TXS operation by acquiring a TXOP and sending an MRTT frame 1508 to AP1404 and 1406. The MRTT frame 1508 can have a similar format to the MU-RTS trigger frame 600 described above. For example, the MRTT frame 1508 may indicate the identifiers of AP1404 and 1406 (e.g., in the respective AID12 subfield of the respective user information field of the MRTT frame 1508) and the TXOP allocation time 1510 (e.g., in the respective allocation duration subfield of the user information field). Furthermore, the MRTT frame 1508 may indicate the TXS mode (e.g., in the triggered TXOP shared mode subfield of the common information field of the MRTT frame 1508). The TXS mode indicates whether AP1404 and 1406 communicate with AP1402 only within the allocated time 1510 (for example, if TXS mode is set to 1), or whether AP1404 and 1406 can communicate with AP1402 or another STA (for example, an associated non-APSTA or another APSTA) within the allocated time 1510.

[0199] In one embodiment, the MRTT frame 1508 may further indicate a time period 1524 for DL ​​or cooperative UL transmission within the allocated time 1510.

[0200] In one embodiment, AP1402 may determine the time period 1524 based on the DL or UL transmission parameters shown in frame 1504 and / or the DL or UL transmission parameters shown in frame 1506.

[0201] In one embodiment, AP1402 may determine a first data rate for DL ​​or UL transmission for AP1404 based on the DL or UL transmission parameters shown in frame 1504. In one embodiment, AP1402 may further determine a second data rate for DL ​​transmission for AP1406 based on the DL or UL transmission parameters shown in frame 1506. For example, AP1402 may determine the first or second data rate based solely on the MCS index shown in frame 1504 or 1506, or based on a combination of the MCS index and the PPDU type or format, bandwidth value, and / or number of spatial streams. For example, the first or second data rate may be determined using the MCS table provided in the IEEE 802.11 standard.

[0202] In one embodiment, in the case of DL, AP1402 can determine a first time period for DL ​​transmission using a first data rate and the amount of traffic buffered for DL ​​transmission at AP1404 (e.g., shown in frame 1504). In one embodiment, AP1402 can determine a second duration for DL ​​transmission using a second data rate and the amount of traffic buffered for DL ​​transmission at AP1406 (e.g., shown in frame 1506). In one embodiment, AP1402 can select the longer of the first and second durations as the time period 1524. Thus, it is ensured that the time period 1524 is long enough to accommodate the DL traffic requests of both AP1404 and 1406. In another embodiment, the time period 1524 may be subject to the maximum PPDU duration; that is, the time period 1524 cannot exceed the maximum PPDU duration. In another embodiment, AP1402 can select the shorter of the first and second durations as the time period 1524. This allows time period 1524 to be fully utilized for DL ​​transmission of data traffic by AP1404 and 1406. In other words, neither AP1404 nor 1406 may need to add padding to their respective DL PPDUs to match the transmission duration to time period 1524.

[0203] In one embodiment, in the case of DL, AP1402 can determine a first time period using a first data rate and the amount of UL traffic shown in frame 1504. In one embodiment, AP1402 can determine a second duration using a second data rate and the amount of traffic shown in frame 1506. In one embodiment, AP1402 can select the longer of the first and second durations as the time period 1524. Thus, it is ensured that the time period 1524 is long enough to accommodate the UL traffic requests shown by both AP1404 and 1406. In another embodiment, the time period 1524 may be affected by the maximum PPDU duration; that is, the time period 1524 cannot exceed the maximum PPDU duration. In another embodiment, AP1402 can select the shorter of the first and second durations as the time period 1524. This means that time period 1524 can be fully utilized for UL transmission of data traffic to both AP1404 and 1406. In other words, in the case of UL, neither UL PPDU 1520 nor 1522 may need to include padding bits to align the transmission duration with time period 1524.

[0204] In one embodiment, the MRTT frame 1508 may include the duration of a time period 1524. In one embodiment, the start time of the time period 1524 may be determined based on the MRTT frame 1508. For example, the start time of the time period 1524 may be the time when the MRTT frame 1508 is received plus the 2SIFS and CTS frame transmission time (and optionally, in the case of UL transmission, the length of the time period for DL ​​transmission of the allocated time 1510). The end time of the time period 1524 can be determined based on the start time and the specified duration.

[0205] In another embodiment, the MRTT frame 1508 may include the start and end times of a time period 1524, the start time and duration of a time period 1524, or the duration and end time of a time period 1524. In such an embodiment, the start time of a time period 1524 may not be based on the MRTT frame 1508.

[0206] In another embodiment, the MRTT frame 1508 may indicate time period 1524 as a segment of allocated time 1510. For example, the MRTT frame 1508 may indicate that time period 1524 corresponds to the first or second half of allocated time 1510, or the first or last X microseconds of allocated time 1510, etc.

[0207] In another embodiment, the MRTT frame 1508 may indicate the time period 1524 by indicating the number of OFDM symbols (of a predetermined duration) transmitted during the time period 1524.

[0208] In other embodiments, AP1402 may initiate inter-AP TXS operation by transmitting a frame other than an MRTT frame. For example, AP1402 may use a multi-AP trigger frame to initiate inter-AP TXS operation. The multi-AP trigger frame may contain or show the same information as described above as being included in or shown in MRTT frame 1508. AP1404 and 1406 may or may not respond to or acknowledge the multi-AP trigger frame from AP1402.

[0209] As shown in Figure 15a (for DL), AP1404 and 1406 can respond to MRTT frame 1508 by sending CTS frames 1512 and 1514 to AP1402, respectively. Subsequently, for example, after SIFS following the transmission of CTS frames 1512 and 1514, AP1404 and 1406 may use the allocated time 1510 for communication, without a trigger from AP1402, according to the TXS mode indicated in MRTT frame 1508 and taking into account the time period 1524. In example 1500, the TXS mode may allow AP1404 and 1406 to communicate with AP1402 or another STA during the allocated time 1510. Thus, as shown in Figure 15a, AP1404 can use the time period 1524 of allocated time 1510 to send a (non-TB)DL PPDU 1516 to the relevant STA (not shown in Figure 15a). AP1404 can use the DL transmit parameters shown in frame 1504 when transmitting DL PPDU 1516. DL PPDU 1516 includes a transmit duration equal to time period 1524. Similarly, AP1406 can use time period 1524 to transmit (non-TB) DL PPDU 1518 to the associated STA (not shown in Figure 15a). AP1404 can use the DL transmit parameters shown in frame 1506 when transmitting DL PPDU 1518. DL PPDU 1518 includes a transmit duration equal to time period 1524. In Example 1500, AP1406 can insert padding bits into the payload of DL PPDU 1518 so that the transmit duration of PPDU 1518 is equal to time period 1524. However, if time period 1524 is set by AP1402 as described above, AP1404 does not need to insert any padding bits into DL PPDU 1516 and can allocate time period 1524 to transmitting buffered DL data throughout. Therefore, the utilization of allocated time 1510, and especially allocated time period 1524 for DL ​​transmission, is increased.

[0210] As shown in Figure 15b (for UL), AP1404 and 1406 can respond to MRTT frame 1508 by sending CTS frames 1512 and 1514, respectively, to AP1402. Subsequently, for example, after SIFS following the transmission of CTS frames 1512 and 1514, AP1404 and 1406 may use the allocated time 1510 for communication, without a trigger from AP1402, according to the TXS mode indicated in MRTT frame 1508 and taking into account the time period 1524. In example 1500, the TXS mode may allow AP1404 and 1406 to communicate with AP1402 or another STA during the allocated time 1510. Thus, in one example, as shown in Figure 15b, AP1404 can use the first portion of the allocated time 1510 to send a (non-TB)DL PPDU 1516 to the relevant STA (not shown in Figure 15b). Similarly, AP1406 can use the first portion of the allocated time 1510 to send a (non-TB)DL PPDU 1518 to the associated STA (not shown in Figure 15). AP1404 can then use the first time period 1524 to receive a UL PPDU 1520 from a first STA associated with AP1404 (not shown in Figure 15b). Similarly, AP1406 can use the first time period 1524 to receive a UL PPDU 1522 from a second STA associated with AP1406 (not shown in Figure 15b). In one example, AP1404 can send a frame to the first STA in the first portion of the allocated time 1510 to prompt or trigger a UL PPDU 1520. In one example, AP1406 can send a frame to the second STA in the first portion of the allocated time 1510 to prompt or trigger a UL PPDU 1522. In another example, the start time of the first time period 1524 may coincide with the start time of the allocated time 1510.Therefore, the first and second STAs, which do not necessarily undergo DL transmission before UL transmission, may be triggered by MRTT frame 1508 to transmit UL PPDU 1520 and 1522, respectively.

[0211] In an example related to DL, AP1404 may use the remaining duration of the allocated time 1510 to receive UL PPDU 1520 from the associated STA (not shown in Figure 15), following any instructions in MRTT frame 1508. In one example, AP1406 may use the remaining duration of the allocated time 1510 to receive UL PPDU 1522 from the associated STA (not shown in Figure 15), following any instructions in MRTT frame 1508.

[0212] In embodiments relating to UL, the first STA can use the UL transmission parameters shown in frame 1504 when transmitting UL PPDU 1520. UL PPDU 1520 includes a transmission duration equal to time period 1524. In one embodiment, the second STA can use the UL transmission parameters shown in frame 1506 when transmitting UL PPDU 1522. UL PPDU 1522 includes a transmission duration equal to time period 1524. In Example 1500, the second STA can insert padding bits into the payload of UL PPDU 1522 so that the transmission duration of PPDU 1522 is equal to time period 1524. However, if time period 1524 is set by the first STA as described above, AP 1404 does not need to insert any padding bits into UL PPDU 1520 and can use the entire time period 1524 to transmit buffered UL data to AP 1404. Therefore, the utilization rate of allocated time 1510, and especially allocated time period 1524 for UL transmission, will increase.

[0213] In one example, C-OFDMA may be used to transmit DL PPDU 1516 and 1518, and UL PPDU 1520 and 1522. Specifically, AP 1402 can allocate mutually orthogonal frequency resources to AP 1404 and 1406 over an allocation time of 1510. For example, AP 1402 can split an 80MHz channel into two non-overlapping 40MHz channels and allocate each channel to AP 1404 and 1406, respectively. In one example, the frequency resources allocated to the APs are shown in the RU allocation subfield of the user information field (which indicates the AP identifier) ​​in the MRTT frame 1508. Thus, DL PPDU 1516 and UL PPDU 1520 may be transmitted with RUs orthogonal to the RUs used to transmit DL PPDU 1518 and UL PPDU 1522.

[0214] In another embodiment related to DL (not shown in Figure 15a), AP1404 may include a DL BSR in frame 1504, but may not include DL transmit parameters in frame 1504. Similarly, AP1406 may include a DL BSR in frame 1506, but may not include DL transmit parameters in frame 1506. AP1402 may determine a time period 1524 for DL ​​transmission based on one or both of the DL BSRs received from AP1404 and 1406. In one embodiment, AP1402 may further determine DL transmit parameters for DL ​​transmission for one or more of AP1404 and 1406 based on one or both of the DL BSRs received from AP1404 and 1406. In one embodiment, the DL transmit parameters may include the number of MCS, DL time resource allocation information, DL frequency resource allocation information, or spatial streams for DL ​​transmission. AP1402 may include the determined DL transmit parameters in MRTT frame 1508. By selecting time period 1524 and DL transmission parameters based on the DL BSR, AP1402 can ensure that at least one of AP1404 and 1406 fully utilizes time period 1524 for DL ​​transmission of data traffic (i.e., without padding).

[0215] In another embodiment related to UL (not shown in Figure 15b), AP1404 may include the amount of UL traffic for the first STA in frame 1504, but may not include the UL transmit parameters for the UL transmission from the first STA to AP1404 in frame 1504. Similarly, AP1406 may include the amount of UL traffic for the second STA in frame 1506, but may not include the UL transmit parameters for the UL transmission from the second STA to AP1406 in frame 1506. AP1402 may determine the time period 1524 based on one or both of the amount of UL traffic for the first STA and the amount of UL traffic for the second STA. In one example, AP1402 may further determine the UL transmit parameters for the UL transmission to AP1404 and / or to AP1406 based on one or more of the amount of UL traffic for the first STA and the amount of UL traffic for the second STA. In one embodiment, the UL transmit parameters may include the MCS, UL time resource allocation information, UL frequency resource allocation information, or the number of spatial streams for UL transmission. AP1402 can include the determined UL transmit parameters in the MRTT frame 1508. By selecting the time period 1524 and the UL transmit parameters based on one or more of the UL traffic volume for the first STA and the UL traffic volume for the second STA, AP1402 can ensure that at least one of the first and second STAs fully utilizes the time period 1524 for UL transmission of data traffic (i.e., without padding).

[0216] Figure 16 shows examples of A-control fields 1602 and 1604 that can be used in embodiments. A-control fields 1602 and 1604 may be used to transmit DL transmission parameters and / or DL ​​BSR in QoS data frames or QoS null frames. As shown in Figure 16, A-control fields 1602 and 1604 may include a Control ID field indicating the type of A-control field 1602 and 1604. In one embodiment, the Control ID field may indicate that A-control fields 1602 and 1604 include a BSR for DL ​​cooperative transmission ("C-BSR"). In one embodiment, A-control field 1602 includes a DL Tx parameter field and a Queue size field. The DL Tx parameter field indicates the DL transmission parameters as described above. The Queue size field includes the DL BSR. In one embodiment, A-control field 1604 includes a DL time resource allocation field and a DL frequency resource allocation field. The DL time resource allocation field may include or indicate the duration for DL ​​cooperative transmission. The DL frequency resource allocation field may include or indicate the RU size or RU type (e.g., 26-tone RU, 52-tone RU, etc.) for cooperative DL transmission.

[0217] Figure 16b shows examples of A-control fields 1602 and 1604 that can be used in embodiments. A-control fields 1602 and 1604 may be used in QoS data frames or QoS null frames to carry UL transmit parameters and / or the amount of UL traffic for STA. As shown in Figure 16, A-control fields 1602 and 1604 may include a control ID field indicating the type of A-control fields 1602 and 1604. In one embodiment, the control ID field may indicate that A-control fields 1602 and 1604 contain a BSR for UL cooperative transmit ("C-BSR"). In one embodiment, A-control field 1602 includes a UL Tx parameter field and an Amount of UL traffic field. The UL Tx parameter field indicates the UL transmit parameters as described above. The Amount of UL traffic field indicates the amount of UL traffic for STA. In one embodiment, the A control field 1604 includes a UL time resource allocation field and a UL frequency resource allocation field. The UL time resource allocation field may include or indicate a duration for UL cooperative transmission. The UL frequency resource allocation field may include or indicate a RU size or RU type (e.g., 26-tone RU, 52-tone RU, etc.) for cooperative UL transmission.

[0218] Figures 17a and 17b show examples of information elements 1702 and 1704 that can be used in embodiments. Information elements 1702 and 1704 may be used to carry DL or UL transmission parameters and / or DL ​​BSR (or UL traffic volume for STA) in the action frame. As shown in Figures 17a and 17b, information elements 1702 and 1704 may include an Element ID field, a Length field, and an Element ID Extension field. The Element ID and Element ID Extension fields indicate the type of information elements 1702 and 1704. In one embodiment, the Element ID and Element ID Extension fields may indicate that information elements 1702 and 1704 contain a BSR for DL ​​or UL cooperative transmission ("C-BSR"). In one embodiment, information element 1702 further includes a DL Tx parameter field or a UL Tx parameter field, as well as a Queue size (or UL traffic volume) field. The DL Tx parameter field or UL Tx parameter field indicates the DL or UL transmission parameters as described above. The queue size or UL traffic volume field indicates the DL BSR or UL traffic volume for the STA. In one embodiment, information element 1704 further includes a DL time resource allocation field or a DL time resource allocation field and a DL frequency resource allocation field or a UL frequency resource allocation field. The DL or UL time resource allocation field may include or indicate the duration for DL ​​or UL coordinated transmission. The DL or UL frequency resource allocation field may include or indicate the RU size or RU type (e.g., 26-tone RU, 52-tone RU, etc.) for coordinated DL or UL transmission.

[0219] Figure 18 shows an exemplary process 1800 according to an embodiment. The exemplary process 1800 may be performed by a first AP such as AP 1402 described above. As shown in Figure 18, process 1800 includes steps 1802 and 1804.

[0220] In the case of DL, step 1802 may include the first AP receiving a first frame from the second AP, which indicates DL transmission parameters for DL ​​transmission. In one embodiment, the first AP may be part of a multi-AP group. The multi-AP group may include a second AP. The first AP may be the master AP of the multi-AP group, and the second AP may be a slave AP of the multi-AP group.

[0221] In the case of UL, step 1802 includes the first AP receiving a first frame from the second AP indicating the amount of UL traffic for the STA associated with the second AP. In one embodiment, the first AP may be part of a multi-AP group, which may include a second AP. The first AP may be the master or sharing AP of the multi-AP group, and the second AP may be the slave or shared AP of the multi-AP group. The amount of UL traffic for the STA may correspond to the amount of traffic buffered by the STA for uplink transmission to the second AP.

[0222] In one embodiment, DL transmission is a multi-AP transmission including a second AP. Multi-AP transmission may be coordinately controlled or initiated by the first AP. Multi-AP transmission may or may not include the first AP. Multi-AP transmission may include a third AP. Multi-AP transmission can be C-OFDMA transmission, C-SR transmission, C-BF, or cooperative joint transmission.

[0223] In one embodiment, the DL transmission parameters are selected by a second AP from a plurality of DL transmission parameters. In one embodiment, the DL transmission parameters are proposed by the second AP for DL ​​transmission. In one embodiment, the DL transmission parameters are preferred by the second AP for DL ​​transmission.

[0224] In embodiments, the DL transmission parameters may include or represent one or more of the following for DL ​​transmission: MCS, bandwidth (BW) size, RU, PPDU type, or spatial stream number (Nss). In one embodiment, the DL transmission parameters may include or represent DL time resource allocation information or DL ​​frequency resource allocation information for the DL transmission. The DL time resource allocation information may indicate the duration for the DL transmission. The DL frequency resource allocation information may include the RU size for the DL transmission.

[0225] In one embodiment, the first frame includes an action frame. The action frame may include an information element containing DL transmission parameters. In another embodiment, the first frame includes a QoS null or a QoS data frame. The QoS null frame or QoS data frame may include an A control field containing DL transmission parameters.

[0226] Step 1804 includes the first AP sending a second frame to the second AP, which indicates a time period for DL ​​transmission, determined based on DL transmission parameters, and a time period for UL transmission from the STA to the second AP, based on the amount of UL traffic.

[0227] In one embodiment, DL transmission is a multi-AP transmission performed in the context of an AP-to-AP TXS procedure, as described above. For example, DL transmission may be performed within a TXOP acquired by a first AP. Thus, the first AP may be a sharing AP and the second AP may be a shared AP. In such an embodiment, the first frame may further indicate the TXOP allocation time acquired by the first AP. The first frame may further indicate the identifier of the second AP, indicating that it is sharing the allocation time with the second AP. In the case of UL, in one embodiment, the second frame further indicates the TXOP allocation time acquired by the first AP.

[0228] In one embodiment, in the case of DL, the second frame includes an MRTT frame or a multi-AP trigger frame.

[0229] In one embodiment, in the case of DL, the first frame may further include a DL BSR. The DL BSR may indicate the amount of DL traffic buffered by the second AP. In one embodiment, the duration of the DL transmission is further based on the DL BSR. In the case of UL, in one embodiment, the duration is within the TXOP allocation time.

[0230] In one embodiment, the first frame further indicates UL transmission parameters for UL transmission. The UL transmission parameters may be selected, proposed, and / or preferred by a second AP for UL transmission. The UL transmission parameters may include one or more of the following for DL ​​transmission: MCS, bandwidth size, RU size, PPDU type, or spatial stream count.

[0231] In one embodiment, the time period is further based on UL transmission parameters.

[0232] In one embodiment, the UL transmission includes a UL PPDU. In one embodiment, the time period includes the duration of the UL PPDU. The UL PPDU may be part of a C-OFDMA UL transmission. A C-OFDMA UL transmission may consist of the UL transmission and further UL transmissions. Further UL transmissions may be from another STA to the first AP or a third AP. The C-OFDMA UL transmission may be performed within the TXOP allocation time acquired by the first AP.

[0233] In embodiments relating to DL, process 1800 may further include the first AP sending a third frame to the second AP requesting a DL BSR from the second AP for DL ​​transmission. The third frame may include a BSRP trigger frame, a basic trigger frame, a polling frame, or a request frame. In embodiments, process 1800 may further include the first AP receiving a first frame in response to the third frame from the second AP.

[0234] In embodiments relating to UL, the first frame includes an ULBSR for the STA, where the ULBSR indicates the amount of UL traffic for the STA. In one embodiment, process 1800 may further include the first AP sending a third frame requesting an ULBSR to the second AP, and the first AP receiving a first frame from the second AP in response to the third frame. In one embodiment, the third frame includes a BSRP trigger frame, a basic trigger frame, a polling frame, or a request frame. In one embodiment, the ULBSR is a C-OFDMA BSR.

[0235] In one embodiment related to UL, the second frame includes an MRTT frame or a multi-AP trigger frame. In one embodiment, the second frame further indicates the identifier of the second AP.

[0236] In embodiments relating to UL, the first frame includes an action frame. The action frame may include an information element containing the amount of UL traffic for STA. In another embodiment, the first frame includes a QoS null or QoS data frame. The QoS null frame or QoS data frame may include an A control field containing the amount of UL traffic for STA.

[0237] Figure 19 shows another exemplary process 1900 according to an embodiment. The exemplary process 1900 may be performed by a first AP such as AP 1402 described above. As shown in Figure 19, process 1900 includes steps 1902 and 1904.

[0238] Step 1902 includes the first AP receiving a first frame from the second AP, associated with the second AP, showing the DL BSR for DL ​​transmissions and the amount of UL traffic for the STA. In one embodiment, the first AP may be part of a multi-AP group, which may include a second AP. The first AP may be the master or sharing AP of the multi-AP group, and the second AP may be the slave or shared AP of the multi-AP group. For DL, the DL BSR may show the amount of DL traffic buffered at the second AP, and for UL, the amount of UL traffic for the STA may correspond to the amount of traffic buffered at the STA for uplink transmissions to the second AP.

[0239] In one embodiment for DL, the DL transmission is a multi-AP transmission including a second AP. The multi-AP transmission may be coordinated and initiated by the first AP. The multi-AP transmission may or may not include the first AP. The multi-AP transmission may include a third AP. The multi-AP transmission can be a C-OFDMA transmission, a C-SR transmission, a C-BF transmission, or a coordinated joint transmission.

[0240] Step 1904 includes, if it is a DL from the first AP to the second AP, sending a second frame indicating the time period for the DL transmission and the DL transmission parameters to the second AP for said DL transmission. If it is a UL, step 1904 includes sending a second frame from the first AP to the second AP indicating the duration of the UL PPDU in the UL transmission from the STA to the second AP, and the transmission parameters of said UL PPDU.

[0241] The UL PPDU may be part of a C-OFDMA UL transmission. A C-OFDMA UL transmission may consist of the UL transmission and a further UL transmission. The further UL transmission may be from another STA to the first or third AP. In one embodiment, the second frame further indicates the TXOP allocation time acquired by the first AP. The C-OFDMA UL transmission may be performed within the TXOP allocation time acquired by the first AP.

[0242] In embodiments, the DL transmission parameters may include or represent one or more of the following for DL ​​transmission: MCS, bandwidth (BW) size, RU, PPDU type, or spatial stream number (Nss). In one embodiment, the DL transmission parameters may include or represent DL time resource allocation information or DL ​​frequency resource allocation information for the DL transmission. The DL time resource allocation information may indicate the duration for the DL transmission. The DL frequency resource allocation information may include the RU size for the DL transmission.

[0243] In one embodiment, the time period for DL ​​transmission and at least one of the DL transmission parameters for the second AP are determined based on the DL BSR.

[0244] The UL transmission parameters may include one or more of the following for DL ​​transmission: MCS, bandwidth size, RU size, PPDU type, or number of spatial streams.

[0245] In one embodiment, a DL transmission is a multi-AP transmission performed in the context of an AP-to-AP TXS procedure, as described above. For example, a DL transmission may be performed within a TXOP acquired by a first AP. Thus, the first AP may be a sharing AP and the second AP may be a shared AP. In such an embodiment, the first frame may further indicate the TXOP allocation time acquired by the first AP. The first frame may further indicate the identifier of the second AP, indicating that it is sharing the allocation time with the second AP. In one embodiment for UL, the frame includes an MRTT frame or a multi-AP trigger frame. In one embodiment, the second frame further indicates the identifier of the second AP.

[0246] In one embodiment, the first frame includes an ULBSR for the STA, where the ULBSR indicates the amount of UL traffic for the STA. In one embodiment, process 1900 may further include the first AP sending a third frame requesting an ULBSR to the second AP, and the first AP receiving a first frame from the second AP in response to the third frame. In one embodiment, the third frame includes a BSRP trigger frame, a basic trigger frame, a polling frame, or a request frame. In one embodiment, the ULBSR is a C-OFDMA BSR.

[0247] Figure 20 shows another exemplary process 2000 relating to an embodiment for DL. The exemplary process 2000 may be performed by a first AP such as AP1404 or 1406 described above. As shown in Figure 20, process 2000 includes steps 2002 and 2004.

[0248] In the case of DL, step 2002 may include the first AP sending a first frame indicating DL transmission parameters for DL ​​transmission to the second AP. In one embodiment, the first AP may be part of a multi-AP group. The multi-AP group may include a second AP. The first AP may be a slave AP of the multi-AP group, and the second AP may be the master AP of the multi-AP group.

[0249] In one embodiment for DL, the DL transmission is a multi-AP transmission including a first AP. The multi-AP transmission may be coordinated and initiated by a second AP. The multi-AP transmission may or may not include a second AP. The multi-AP transmission may include a third AP. The multi-AP transmission may be a C-OFDMA transmission, a C-SR transmission, a C-BF transmission, or a coordinated joint transmission.

[0250] In one embodiment, for DL, the DL transmission parameters are selected by the first AP from a plurality of DL transmission parameters. In one embodiment, the DL transmission parameters are proposed by the first AP for DL ​​transmission. In one embodiment, the DL transmission parameters are preferred by the first AP for DL ​​transmission.

[0251] In embodiments for DL, the DL transmit parameters may include or indicate one or more of the following for DL ​​transmit: MCS, bandwidth (BW) size, RU, PPDU type, or spatial stream number (Nss). In one embodiment, the DL transmit parameters may include or indicate DL time resource allocation information or DL ​​frequency resource allocation information for the DL transmit. The DL time resource allocation information may indicate the duration for the DL transmit. The DL frequency resource allocation information may include the RU size for the DL transmit.

[0252] In an embodiment for DL, the first frame includes an action frame. The action frame may include an information element containing DL transmission parameters. In another embodiment, the first frame includes a QoS null or QoS data frame. The QoS null frame or QoS data frame may include an A control field containing DL transmission parameters.

[0253] Step 2004 includes the first AP receiving a second frame from the second AP, which indicates a time period for DL ​​transmission determined based on DL transmission parameters.

[0254] In one embodiment for DL, the DL transmission is a multi-AP transmission performed in the context of an AP-to-AP TXS procedure, as described above. For example, the DL transmission may be performed within a TXOP acquired by a second AP. Thus, the first AP may be a shared AP and the second AP may be a sharing AP. In such an embodiment, the first frame may further indicate the TXOP allocation time acquired by the second AP. The first frame may further indicate an identifier of the first AP indicating that it is sharing the allocation time with the first AP.

[0255] In one embodiment, in the case of DL, the second frame includes an MRTT frame or a multi-AP trigger frame.

[0256] In one embodiment, in the case of DL, the first frame may further include a DL BSR. The DL BSR may indicate the amount of DL traffic buffered at the first AP. In one embodiment, the duration of DL transmission is further based on the DL BSR.

[0257] In one embodiment for DL, process 2000 may further include receiving a frame from a second AP by a first AP. The third frame may include a BSRP trigger frame, a basic trigger frame, a polling frame, or a request frame. In the embodiment, process 2000 further includes sending a first frame to the second AP by the first AP in response to the third frame.

[0258] In embodiments for DL, process 2000 may further include sending a PPDU by a first AP using DL transmission parameters and during the time period for DL ​​transmission. The PPDU may be sent, for example, to an STA associated with the first AP.

[0259] Figure 20 also shows another exemplary process 2000 relating to an embodiment for UL. The exemplary process 2000 may be performed by a first AP such as AP1402 described above. As shown in Figure 20, process 2000 includes steps 2002 and 2004.

[0260] In the case of UL, step 2002 includes the first AP receiving a first frame from the second AP, which indicates UL time resource information for UL transmission from the STA to the second AP, and / or UL frequency resource information for said UL transmission. In one embodiment, the first AP may be part of a multi-AP group. The multi-AP group may include a second AP. The first AP may be the master or sharing AP of the multi-AP group, and the second AP may be the slave or shared AP of the multi-AP group. The STA may be associated with the second AP.

[0261] A UL transmission may be part of a C-OFDMA UL transmission. A C-OFDMA UL transmission may consist of such UL transmission and further UL transmissions. Further UL transmissions may be from another STA to the first AP or a third AP.

[0262] In the case of UL, step 2004 includes the first AP receiving a second frame from the second AP, which indicates the duration of the UL PPDU for UL transmission, determined based on UL time resource information and / or UL frequency resource information.

[0263] In embodiments for UL, the second frame further indicates the TXOP allocation time acquired by the first AP. The C-OFDMA UL transmission may be performed within the TXOP allocation time acquired by the first AP.

[0264] In the embodiment of UL, UL time resource information is preferred, recommended, or selected by a second AP. In one embodiment, the UL time resource information includes the length of the UL PPDU.

[0265] In embodiments for UL, UL frequency resource information is preferred, recommended, or selected by a second AP. In one embodiment, the UL frequency resource information includes the size of the frequency RU for UL transmission.

[0266] In one embodiment, in the case of UL, the second frame includes an MRTT frame or a multi-AP trigger frame. In one embodiment, the second frame further indicates the identifier of the second AP.

[0267] In an embodiment for UL, the first frame includes an action frame. The action frame may include an information element containing UL time resource information and / or UL frequency resource information. In another embodiment, the first frame includes a QoS null or QoS data frame. The QoS null frame or QoS data frame may include an A control field containing UL time resource information and / or UL frequency resource information.

[0268] Figure 21 shows another exemplary process 2100 relating to embodiments for DL ​​and UL. The exemplary process 2100 may be performed by a first AP such as AP 1404 or 1406 described above. As shown in Figure 21, process 2100 includes steps 2102 and 2104.

[0269] In the case of DL, step 2102 may include the first AP sending a first frame indicating the DL BSR for DL ​​transmission to the second AP. In one embodiment, the first AP may be part of a multi-AP group. The multi-AP group may include a second AP. The first AP may be a slave AP of the multi-AP group, and the second AP may be the master AP of the multi-AP group. The DL BSR may indicate the amount of DL traffic buffered by the first AP.

[0270] In one embodiment for DL, the DL transmission is a multi-AP transmission including a first AP. The multi-AP transmission may be coordinated and initiated by a second AP. The multi-AP transmission may or may not include a second AP. The multi-AP transmission may include a third AP. The multi-AP transmission may be a C-OFDMA transmission, a C-SR transmission, a C-BF transmission, or a coordinated joint transmission.

[0271] Step 2104 includes receiving a second frame from the second AP via the first AP, which indicates the time period for DL ​​transmission and the DL transmission parameters for the first AP for said DL transmission.

[0272] In an embodiment for DL, the DL transmission parameters may include or indicate one or more of an MCS, a bandwidth (BW) size, an RU, a PPDU type, or a number of spatial streams (Nss) for DL transmission. In one embodiment, the DL transmission parameters may include or indicate DL time resource allocation information or DL frequency resource allocation information for the DL transmission. The DL time resource allocation information may indicate a duration for DL transmission. The DL frequency resource allocation information may include an RU size for DL transmission.

[0273] In one embodiment for DL, at least one of a time period for the first AP for DL transmission and the DL transmission parameters is determined based on a DL BSR.

[0274] In an example for DL, as described above, the DL transmission is multi-AP transmission performed in the context of an inter-AP TXS procedure. For example, the DL transmission may be performed within a TXOP obtained by a second AP. Accordingly, the first AP may be a shared AP and the second AP may be a sharing AP. In such embodiments, the first frame may further indicate a TXOP allocation duration obtained by the second AP. The first frame may further indicate an identifier of the first AP indicating that the allocation duration is being shared with the first AP.

[0275] In an embodiment for DL, process 2100 may further include transmitting, by the first AP, a PPDU using the DL transmission parameters and during the time period for DL transmission. The PPDU may, for example, be transmitted to a STAs associated with the first AP.

[0276] In the case of UL, the example process 2100 may be performed by a first AP, such as the aforementioned AP 1404 or 1406. As shown in FIG. 21, process 2100 includes steps 2102 and 2104.

[0277] In the case of UL, step 2102 includes the first AP sending a first frame to the second AP that indicates the amount of UL traffic for the STA associated with the first AP. In one embodiment, the first AP may be part of a multi-AP group. The multi-AP group may include a second AP. The second AP may be the master or sharing AP of the multi-AP group, and the first AP may be the slave or shared AP of the multi-AP group. The amount of UL traffic for the STA may correspond to the amount of traffic buffered by the STA for uplink transmission to the first AP.

[0278] In the case of UL, step 2104 includes the first AP receiving from the second AP a second frame from the first AP indicating a time period based on the amount of UL traffic for UL transmission from the STA to the first AP.

[0279] In embodiments for UL, the second frame further indicates the allocation time of the TXOP acquired by the first AP. In one embodiment, the time period is within the TXOP allocation time.

[0280] In one embodiment, the first frame further indicates UL transmission parameters for UL transmission. The UL transmission parameters may be selected, proposed, and / or preferred by the first AP for UL transmission. The UL transmission parameters may include one or more of the following for DL ​​transmission: MCS, bandwidth size, RU size, PPDU type, or spatial stream count.

[0281] In one embodiment for UL, the time period is further based on UL transmission parameters.

[0282] In one embodiment for UL, the UL transmission includes a UL PPDU. In one embodiment, the time period includes the duration of the UL PPDU. The UL PPDU may be part of a C-OFDMA UL transmission. A C-OFDMA UL transmission may consist of the said UL transmission and a further UL transmission. The further UL transmission may be from another STA to a second or third AP. The C-OFDMA UL transmission may be performed within the TXOP allocation time acquired by the second AP.

[0283] In one embodiment for UL, the first frame includes an ULBSR for STA, where the ULBSR indicates the amount of UL traffic for STA. In one embodiment, process 2100 may further include the first AP sending a third frame from the second AP requesting an ULBSR, and the first AP sending a first frame to the second AP in response to the third frame. In one embodiment, the third frame includes a BSRP trigger frame, a basic trigger frame, a polling frame, or a request frame. In one embodiment, the ULBSR is a C-OFDMA BSR.

[0284] In one embodiment, the second frame includes an MRTT frame or a multi-AP trigger frame. In one embodiment, the second frame further indicates the identifier of the first AP.

[0285] In an embodiment for UL, the first frame includes an action frame. The action frame may include an information element containing the amount of UL traffic for STA. In another embodiment, the first frame includes a QoS null or QoS data frame. The QoS null frame or QoS data frame may include an A control field containing the amount of UL traffic for STA.

[0286] Figure 22 shows another exemplary process 2200 according to an embodiment. The exemplary process 2200 may be performed by a first AP such as AP 1404 or 1406 described above. As shown in Figure 22, process 2200 includes steps 2202 and 2204.

[0287] Step 2202 includes the first AP sending a first frame to the second AP that indicates the amount of UL traffic for the STA associated with the first AP. In one embodiment, the first AP may be part of a multi-AP group, which may include a second AP. The second AP may be the master or sharing AP of the multi-AP group, and the first AP may be the slave or shared AP of the multi-AP group. The amount of UL traffic for the STA may correspond to the amount of traffic buffered by the STA for uplink transmission to the first AP.

[0288] Step 2204 includes the first AP receiving a second frame from the second AP indicating the duration of the UL PPDU in the UL transmission from the STA to the first AP, and the transmission parameters of the UL PPDU.

[0289] The UL PPDU may be part of a C-OFDMA UL transmission. A C-OFDMA UL transmission may consist of the UL transmission and a further UL transmission. The further UL transmission may be from another STA to a second or third AP. In one embodiment, the second frame further indicates the allocation time of the TXOP acquired by the first AP. The C-OFDMA UL transmission may be performed within the TXOP allocation time acquired by the second AP.

[0290] The UL transmission parameters may include one or more of the following for DL ​​transmission: MCS, bandwidth size, RU size, PPDU type, or number of spatial streams.

[0291] In one embodiment, the first frame includes an ULBSR for the STA, where the ULBSR indicates the amount of UL traffic for the STA. In one embodiment, process 2200 may further include the first AP sending a third frame from the second AP requesting an ULBSR, and the first AP sending a first frame to the second AP in response to the third frame. In one embodiment, the third frame includes a BSRP trigger frame, a basic trigger frame, a polling frame, or a request frame. In one embodiment, the ULBSR is a C-OFDMA BSR.

[0292] In one embodiment, the second frame includes an MRTT frame or a multi-AP trigger frame. In one embodiment, the second frame further indicates the identifier of the first AP.

[0293] In one embodiment, the first frame includes an action frame. The action frame may include an information element containing the amount of UL traffic for the STA. In another embodiment, the first frame includes a QoS null or a QoS data frame. The QoS null frame or QoS data frame may include an A control field containing the amount of UL traffic for the STA.

[0294] Figure 23 shows another exemplary process 2300 according to an embodiment. The exemplary process 2300 may be performed by a first AP such as AP 1404 or 1406 described above. As shown in Figure 23, process 2300 includes steps 2302 and 2304.

[0295] Step 2302 comprises receiving, by a first AP from a second AP, a first frame indicating UL time resource information for UL transmission from a STA to the first AP, and / or UL frequency resource information for said UL transmission. In one embodiment, the first AP may be part of a multi-AP group. The multi-AP group may include the second AP. The second AP may be a master or sharing AP of the multi-AP group, and the first AP may be a slave or shared AP of the multi-AP group. The STA can be associated with the first AP.

[0296] The UL transmission may be part of C-OFDMA UL transmission. The C-OFDMA UL transmission may consist of said UL transmission and a further UL transmission. The further UL transmission may be from another STA to the second AP or a third AP.

[0297] Step 2304 comprises receiving, by the first AP from the second AP, a second frame indicating a duration of a UL PPDU for the UL transmission, which is determined based on the UL time resource information and / or the UL frequency resource information.

[0298] In one embodiment, the second frame further indicates an allocated TXOP duration obtained by the first AP. The C-OFDMA UL transmission may be performed within the TXOP allocation duration obtained by the second AP.

[0299] In one embodiment, the UL time resource information is preferred, recommended, or selected by the first AP. In one embodiment, the UL time resource information includes the length of the UL PPDU.

[0300] In an embodiment, the UL frequency resource information is preferred, recommended, or selected by the first AP. In one embodiment, the UL frequency resource information includes the size of a frequency RU for the UL transmission.

[0301] In one embodiment, the second frame includes an MRTT frame or a multi-AP trigger frame. In one embodiment, the second frame further indicates the identifier of the first AP.

[0302] In one embodiment, the first frame includes an action frame. The action frame may include an information element containing UL time resource information and / or UL frequency resource information. In another embodiment, the first frame includes a QoS null or QoS data frame. The QoS null frame or QoS data frame may include an A control field containing UL time resource information and / or UL frequency resource information.

[0303] Therefore, in one embodiment, a method is provided which includes: a first access point (AP) receiving a first frame from a second AP showing a Modulation Coding Scheme (MCS) for downlink (DL) transmission; and the first AP transmitting a second frame to the second AP for DL ​​transmission, showing a Transmit Opportunity (TXOP) allocation time acquired by the first AP and a time period within that allocation time, where the time period is determined based on the MCS.

[0304] Furthermore, in one embodiment, a method is provided which includes: a first access point (AP) receiving a first frame indicating downlink (DL) transmission parameters for downlink (DL) transmission from a second AP; and the first AP transmitting a second frame indicating a time period for DL ​​transmission to the second AP, where the time period is determined based on the DL transmission parameters.

[0305] In one embodiment, the DL transmission parameters are selected by the second AP from a plurality of DL transmission parameters.

[0306] In one embodiment, DL transmission parameters are proposed by a second AP for DL ​​transmission.

[0307] In one embodiment, the DL transmission parameters are preferred by a second AP for DL ​​transmission.

[0308] In one embodiment, the DL transmission parameters include one or more of the following: a modulation coding scheme (MCS) for DL ​​transmission, bandwidth size, resource unit (RU) size, physical layer protocol data unit (PPDU) type, or number of spatial streams.

[0309] In one embodiment, the second frame further indicates the Transmit Opportunity (TXOP) allocation time acquired by the first AP.

[0310] In one embodiment, the second frame further indicates the identifier of the second AP.

[0311] In one embodiment, DL transmission is a multi-AP transmission including a second AP.

[0312] In one embodiment, multi-AP transmission is initiated by the first AP.

[0313] In one embodiment, multi-AP transmission includes a first AP.

[0314] In one embodiment, the first frame includes a downlink (DL) buffer status report (BSR).

[0315] In one embodiment, the time period for DL ​​transmission is further based on the DL BSR.

[0316] In one embodiment, DL BSR indicates the amount of DL traffic buffered by the second AP.

[0317] In one embodiment, the first AP sends a third frame to the second AP requesting a buffer status report (BSR) from the second AP for DL ​​purposes.

[0318] One embodiment includes a method in which a first access point (AP) receives a first frame from a second AP showing a downlink (DL) buffer status report (BSR) for downlink (DL) transmission; and the first AP transmits to the second AP a second frame showing the allocated transmission opportunity (TXOP) time obtained by the first AP, the identifier of the second AP, the DL transmission time period, and DL transmission parameters for the second AP for the DL transmission.

[0319] In one embodiment, the time period for DL ​​transmission and at least one of the DL transmission parameters for the second AP are determined based on the DL BSR.

[0320] In one embodiment, DL transmission is a multi-AP transmission performed during the TXOP assignment continuation period.

[0321] In one embodiment, multi-AP transmission is cooperative orthogonal frequency division multiple access (C-OFDMA) transmission.

[0322] In one embodiment, DL transmission includes DL Physical Protocol Data Units (PPDUs).

[0323] In one embodiment, the duration of DL transmission includes the length of the DL PPDU.

[0324] In one embodiment, the DL transmission parameters include one or more of the following: a modulation coding scheme (MCS) for DL ​​transmission, bandwidth size, resource unit (RU) size, physical layer protocol data unit (PPDU) type, or number of spatial streams.

[0325] One embodiment includes a method comprising: transmitting a first frame indicating a Modulation Coding Scheme (MCS) for downlink (DL) transmission from a first access point (AP) to a second AP; and receiving a second frame from the second AP by the first AP indicating the allocated transmission opportunity (TXOP) time and the duration of DL transmission within that allocated time. Here, the duration is determined based on the MCS.

[0326] One embodiment includes a method in which a first access point (AP) transmits a first frame indicating downlink (DL) transmission parameters for downlink (DL) transmission to a second AP; and the first AP receives a second frame indicating a time period for DL ​​transmission from the second AP, where the time period is determined based on the DL transmission parameters.

[0327] In one embodiment, the DL transmission parameters are selected by the first AP from a plurality of DL transmission parameters.

[0328] In one embodiment, DL transmission parameters are proposed by the first AP for DL ​​transmission.

[0329] In one embodiment, the DL transmission parameters are preferred by the first AP for DL ​​transmission.

[0330] In one embodiment, the DL transmission parameters include one or more of the following: a modulation coding scheme (MCS) for DL ​​transmission, bandwidth size, resource unit (RU) size, physical layer protocol data unit (PPDU) type, or number of spatial streams.

[0331] In one embodiment, the DL transmission parameters may include, or include, downlink (DL) time resource allocation information or DL ​​frequency resource allocation information for the DL transmission.

[0332] In one embodiment, the DL time resource allocation information indicates the time period for DL ​​transmission.

[0333] In one embodiment, the DL frequency resource allocation information includes the resource unit (RU) size for DL ​​transmission.

[0334] In one embodiment, the duration of DL transmission is determined based on DL time resource allocation information or DL ​​frequency resource allocation information.

[0335] In one embodiment, the second frame further indicates the Transmit Opportunity (TXOP) allocation time acquired by the second AP.

[0336] In one embodiment, the second frame includes a multi-user RTS (MU-RTSTXS) trigger frame or a multi-AP trigger frame for triggered TXOP sharing.

[0337] In one embodiment, the second frame further indicates the identifier of the first AP.

[0338] In one embodiment, DL transmission is a multi-AP transmission including a first AP.

[0339] In one embodiment, multi-AP transmission is initiated by a second AP.

[0340] In one embodiment, multi-AP transmission includes a second AP.

[0341] In one embodiment, multi-AP transmission is cooperative orthogonal frequency-division multiple access (C-OFDMA) transmission, cooperative time-division multiple access (C-TDMA) transmission, cooperative spatial reuse (C-SR) transmission, cooperative beamforming (C-BF), or cooperative joint transmission.

[0342] In one embodiment, the first frame includes a downlink (DL) buffer status report (BSR).

[0343] In one embodiment, the time period for DL ​​transmission is further based on the DL BSR.

[0344] In one embodiment, DL BSR indicates the amount of DL traffic buffered by the first AP.

[0345] In one embodiment, the first AP receives a third frame from the second AP requesting a buffer status report (BSR) from the first AP.

[0346] In one embodiment, the BSR is a Cooperative Orthogonal Frequency Division Multiple Access (C-OFDMA) BSR.

[0347] In one embodiment, the third frame includes a buffer status report polling (BSRP) trigger frame, a basic trigger frame, a polling frame, or a request frame.

[0348] In one embodiment, the first AP transmits the first frame to the second AP in response to the third frame.

[0349] In one embodiment, the first frame includes an action frame.

[0350] In one embodiment, the action frame includes an information element containing DL transmission parameters.

[0351] In one embodiment, the first frame includes a Quality of Service (QoS) null or a QoS data frame.

[0352] In one embodiment, a QoS null frame or QoS data frame includes an aggregate control (A control) field containing DL transmission parameters.

[0353] In one embodiment, the first AP transmits a Physical Layer Protocol Data Unit (PPDU) using DL transmission parameters and during the time period for DL ​​transmission.

[0354] In one embodiment, a first access point (AP) receives a first frame from a second AP indicating a DL buffer status report (BSR) for downlink (DL) transmission, and the first AP receives a second frame from the second AP indicating the allocated transmission opportunity (TXOP) time obtained by the second AP, the identifier of the first AP, the time period for DL ​​transmission, and DL transmission parameters for the first AP for said DL transmission.

[0355] In one embodiment, the time period for DL ​​transmission and at least one of the DL transmission parameters for the first AP are determined based on the BSR.

[0356] In one embodiment, DL transmission is a multi-AP transmission performed during the TXOP assignment continuation period.

[0357] In one embodiment, multi-AP transmission is cooperative orthogonal frequency division multiple access (C-OFDMA) transmission.

[0358] In one embodiment, DL transmission includes DL Physical Protocol Data Units (PPDUs).

[0359] In one embodiment, the duration of DL transmission includes the length of the DL PPDU.

[0360] In one embodiment, the DL transmission parameters include one or more of the following: a modulation coding scheme (MCS) for DL ​​transmission, bandwidth size, resource unit (RU) size, physical layer protocol data unit (PPDU) type, or number of spatial streams.

[0361] In one embodiment, there is a computer program product that can be stored on a computer-readable medium and is configured to perform any of the methods described herein when executed on a processor.

[0362] In one embodiment, there is a device configured to perform the following operations when implemented in a first access point: the first access point (AP) receives a first frame from a second access point (AP) indicating a Modulation Coding Scheme (MCS) for downlink (DL) transmission; and the first AP transmits a second frame to the second AP indicating the allocated transmission opportunity (TXOP) time and the duration of DL transmission within that allocated time. Here, the duration is determined based on the MCS.

[0363] In one embodiment, there is a device configured to perform the following operations when implemented in a first access point: receiving a first frame from a second access point (AP) indicating downlink (DL) transmission parameters for downlink (DL) transmission by the first access point (AP), and sending a second frame indicating a time period for DL ​​transmission to the second AP. Here, the time period is determined based on the DL transmission parameters.

[0364] In one embodiment, there is a device that, when implemented in a first access point, is configured to perform the following operations: transmit a first frame indicating a modulation coding scheme (MCS) for DL ​​transmission to a second access point (AP); and receive a second frame from the second AP indicating the allocated time of a transmission opportunity (TXOP) acquired by the first AP and the duration of DL transmission within that allocated time. Here, the duration is determined based on the MCS.

[0365] In one embodiment, there is a device that, when implemented in a first access point, is configured to perform an operation including sending a first frame to a second AP indicating DL transmission parameters for a downlink (DL) transmission, and receiving a second frame from the second AP indicating a time period for the DL transmission determined based on the DL transmission parameters, where the time period is determined based on the DL transmission parameters.

[0366] Therefore, in the case of an uplink, one method includes: the first access point (AP) receiving a first frame from the second AP indicating the amount of uplink (UL) traffic for a station (STA) associated with the second AP; and the first AP transmitting a second frame to the second AP indicating the time period for UL transmission from the STA to the second AP, based on the allocated time of the transmit opportunity (TXOP) acquired by the first AP within the allocated time and the amount of UL traffic.

[0367] One embodiment includes a method in which a first access point (AP) receives a first frame from the second AP indicating the amount of uplink (UL) traffic of a station (STA) associated with the second AP, and a second frame is transmitted from the first AP to the second AP, indicating the time period of UL transmission from the STA to the second AP, based on the amount of UL traffic.

[0368] In one embodiment, the second frame further indicates the Transmit Opportunity (TXOP) allocation time acquired by the first AP.

[0369] In one embodiment, the first frame further indicates the UL transmission parameters for UL transmission.

[0370] In one embodiment, the time period is further based on UL transmission parameters.

[0371] In one embodiment, the UL transmission parameters are selected by a second AP from a plurality of UL transmission parameters.

[0372] In one embodiment, the UL transmission parameters are proposed by a second AP for UL transmission.

[0373] In one embodiment, the UL transmission parameters are preferred by a second AP for UL transmission.

[0374] In one embodiment, the UL transmission parameters include one or more of the following: a modulation coding scheme (MCS) for UL transmission, bandwidth size, resource unit (RU) size, physical layer protocol data unit (PPDU) type, or number of spatial streams.

[0375] In one embodiment, the first frame includes a UL buffer status report (BSR) for the STA, where the ULBSR indicates the amount of UL traffic for the STA.

[0376] In one embodiment, the first AP transmits a third frame requesting ULBSR to the second AP, and in response to the third frame, the first AP receives a first frame from the second AP.

[0377] In one embodiment, the third frame includes a buffer status report polling (BSRP) trigger frame, a basic trigger frame, a polling frame, or a request frame.

[0378] In one embodiment, the second frame further indicates the identifier of the second AP.

[0379] In one embodiment, the method includes: a first access point (AP) receiving from the second AP a first frame indicating the amount of uplink (UL) traffic for a station (STA) associated with the second AP; and the first AP transmitting to the second AP a second frame indicating the allocated time of a transmit opportunity (TXOP) acquired by the first AP within the allocated time, the identifier of the second AP, and the duration of an uplink (UL) physical layer protocol data unit (PPDU) for UL transmission from the STA to the second AP, and a modulation and coding scheme (MCS) for the UL PPDU.

[0380] One embodiment includes a method in which a first access point (AP) receives from a second AP a first frame indicating uplink (UL) time resource information for UL transmission from an STA to a second AP and UL frequency resource information for said UL transmission, and the first AP transmits to the second AP a second frame indicating the allocated transmission opportunity (TXOP) time obtained by the first AP, the identifier of the second AP, and the duration of the UL physical layer protocol data unit (PPDU) for UL transmission, determined based on the UL time resource information and the UL frequency resource information.

[0381] In one embodiment, UL time resource information is preferred, recommended, or selected by a second AP.

[0382] In one embodiment, the UL time resource information includes the length of the UL PPDU.

[0383] In one embodiment, UL frequency resource information is preferred, recommended, or selected by a second AP.

[0384] In one embodiment, the UL frequency resource information includes the size of the frequency resource unit (RU) for UL transmission.

[0385] One embodiment includes a method in which a first access point (AP) transmits a first frame to a second AP that indicates the amount of uplink (UL) traffic of a station (STA) associated with a first AP, and a second frame received by the first AP from the second AP that indicates the time period for UL transmission from the STA to the first AP, based on the allocated time of the transmission opportunity (TXOP) acquired by the second AP within the allocated time and the amount of UL traffic.

[0386] One embodiment includes a method in which a first access point (AP) transmits a first frame to a second AP that indicates the amount of uplink (UL) traffic from a station (STA) associated with a first AP, and a second frame is received by the first AP from the second AP, based on the amount of UL traffic, indicating the time period of UL transmission from the STA to the first AP.

[0387] In one embodiment, the second frame further indicates the Transmit Opportunity (TXOP) allocation time acquired by the second AP.

[0388] In one embodiment, the time period is within the TXOP allocation time.

[0389] In one embodiment, the first frame further indicates the UL transmission parameters for UL transmission.

[0390] In one embodiment, the time period is further based on UL transmission parameters.

[0391] In one embodiment, the UL transmission parameters are selected by the first AP from a plurality of UL transmission parameters.

[0392] In one embodiment, UL transmission parameters are proposed by the first AP for UL transmission.

[0393] In one embodiment, the UL transmission parameters are preferred by the first AP for UL transmission.

[0394] In one embodiment, the UL transmission parameters include one or more of the following: a modulation coding scheme (MCS) for UL transmission, bandwidth size, resource unit (RU) size, physical layer protocol data unit (PPDU) type, or number of spatial streams.

[0395] In one embodiment, UL transmission includes a UL Physical Layer Protocol Data Unit (PPDU).

[0396] In one embodiment, the time period includes the duration of the UL PPDU.

[0397] In one embodiment, UL PPDU transmission is part of cooperative orthogonal frequency division multiple access (C-OFDMA) transmission.

[0398] In one embodiment, the first frame includes a buffer status report (BSR) for the STA, and the ULBSR indicates the amount of UL traffic for the STA.

[0399] In one embodiment, the first AP receives a third frame requesting ULBSR from the second AP, and in response to the third frame, the first AP transmits a first frame to the second AP.

[0400] In one embodiment, the third frame includes a buffer status report polling (BSRP) trigger frame, a basic trigger frame, a polling frame, or a request frame.

[0401] In one embodiment, the ULBSR is a cooperative orthogonal frequency-division multiple access (C-OFDMA) BSR.

[0402] In one embodiment, the second frame includes a multi-user RTS (MU-RTSTXS) trigger frame or a multi-AP trigger frame for triggered TXOP sharing.

[0403] In one embodiment, the second frame further indicates the identifier of the first AP.

[0404] In one embodiment, the first frame includes an action frame.

[0405] In one embodiment, the action frame includes an information element that includes the amount of UL traffic for STA.

[0406] In one embodiment, the first frame includes a Quality of Service (QoS) null or a QoS data frame.

[0407] In one embodiment, a QoS null frame or QoS data frame includes an aggregated control (A control) field containing the amount of UL traffic for STA.

[0408] In one embodiment, the first AP transmits a trigger frame to the second AP, and in response to the trigger frame, the first AP receives a UL transmission from the STA.

[0409] One embodiment includes a method comprising: transmitting a first frame from a first access point (AP) to a second AP indicating the amount of uplink (UL) traffic of a station (STA) associated with the first AP; and the first AP receiving a second frame from the second AP indicating the following: the second frame includes the allocated time of a transmit opportunity (TXOP) acquired by the second AP, the identifier of the first AP, the duration of a UL physical layer protocol data unit (PPDU) for UL transmission from the STA to the first AP during the allocated time; and the modulation coding scheme (MCS) of the UL PPDU.

[0410] In one embodiment, the method includes: a first access point (AP) transmitting a first frame to a second AP, which shows uplink (UL) time resource information for UL transmission from the STA to a first AP and UL frequency resource information for the UL transmission; and a second frame received by the first AP from the second AP, which shows the allocated transmission opportunity (TXOP) time acquired by the second AP, the identifier of the first AP, the duration of the UL physical layer protocol data unit (PPDU) for UL transmission determined based on the UL time resource information, and the UL frequency resource information.

[0411] In one embodiment, UL time resource information is preferred, recommended, or selected by the first AP.

[0412] In one embodiment, the UL time resource information includes the length of the UL PPDU.

[0413] In the embodiment, UL frequency resource information is preferred, recommended, or selected by the first AP.

[0414] In one embodiment, the UL frequency resource information includes the size of the frequency resource unit (RU) for UL transmission.

[0415] In one embodiment, there is a computer program product that can be stored on a computer-readable medium and is configured to perform any of the methods of claims 1 to 49 when executed on a processor.

[0416] In one embodiment, there is a device that, when implemented in an access point, is configured to perform the following operations: receive from the second AP by the first access point (AP) a first frame indicating the amount of uplink (UL) traffic of a station (STA) associated with the second AP; and transmit from the first AP to the second AP a second frame indicating the time period of UL transmission from the STA to the second AP, based on the allocated time of the transmit opportunity (TXOP) acquired by the first AP within the allocated time and the amount of UL traffic.

[0417] In one embodiment, there is a device that, when implemented in an access point, is configured to perform operations including receiving a first frame from the second AP by the first access point (AP) indicating the amount of uplink (UL) traffic of a station (STA) associated with the second AP, and sending a second frame from the first AP to the second AP indicating the time period of UL transmission from the STA to the second AP, based on the amount of UL traffic.

[0418] In one embodiment, there is a device configured to perform the following actions when implemented as an access point: a first access point (AP) receives a first frame from a second AP indicating the amount of uplink (UL) traffic for a station (STA) associated with the second AP; and the first AP transmits a second frame to the second AP indicating the allocated time of a transmit opportunity (TXOP) acquired by the first AP, the identifier of the second AP, the duration of the UL physical layer protocol data unit (PPDU) for UL transmission from the STA to the second AP during the allocated time, and the modulation coding scheme (MCS) of the UL PPDU.

[0419] In one embodiment, a device is provided that, when implemented in an access point, includes: a first access point (AP) receiving a first frame from a second AP indicating UL time resource information for an uplink (UL) transmission from the STA to the second AP, and UL frequency resource information for said UL transmission; and the first AP transmitting a second frame to the second AP indicating the allocated transmission opportunity (TXOP) time acquired by the first AP, the identifier of the second AP, and the duration of the UL physical layer protocol data unit (PPDU) for said UL transmission, determined based on the UL time resource information and the UL frequency resource information.

[0420] In one embodiment, there is a device that, when implemented in an access point, is configured to perform the following operations: first access point (AP) transmits a first frame to a second AP indicating the amount of uplink (UL) traffic of a station (STA) associated with the first AP; and first AP receives from the second AP a second frame indicating the time period of UL transmission from the STA to the second AP based on the allocated time of a transmit opportunity (TXOP) acquired by the second AP within the allocated time and the amount of UL traffic.

[0421] In one embodiment, there is a device that, when implemented in an access point, is configured to perform the following operations: a first access point (AP) transmits a first frame to a second AP indicating the amount of uplink (UL) traffic from a station (STA) associated with a first AP; and the first AP receives a second frame from the second AP indicating the time period of UL transmission from the STA to the first AP, based on the amount of UL traffic.

[0422] An embodiment of this design may be a set of computer program instructions stored on a computer-readable storage device that can be executed by a computer, or it may be implemented in a computer program product.

[0423] Instructions may include, but are not limited to, scripts, interpretable programs, dynamic link libraries (DLLs), or Java classes, and may be any interpretable or executable code mechanism. Instructions may be provided as a complete executable program, a partial executable program, a modification to an existing program (e.g., an update), or an extension to an existing program (e.g., a plug-in). Furthermore, some of the processing of the present invention may be distributed across multiple computers or processors.

[0424] Suitable storage media for storing computer program instructions include, but are not limited to, EPROM, EEPROM, and flash memory devices, magnetic disks such as internal and external hard disk drives, removable disks, and CD-ROM disks, and include all forms of non-volatile memory. Computer program products may be distributed on such storage media, or they may be provided for download via HTTP, FTP, email, or through servers connected to a network such as the Internet.

Claims

1. The first access point (AP) receives a first frame from the second AP indicating a Modulation Coding Scheme (MCS) for downlink (DL) transmission. The first AP transmits a second frame to the second AP. A method that includes, The aforementioned second frame is, The allocated time of the transmission opportunity (TXOP) acquired by the first AP, The time period for DL ​​transmission within the aforementioned allocated time, Show, The aforementioned time period is determined based on the MCS. method.

2. The first access point (AP) receives a first frame from the second AP that contains DL transmission parameters for downlink (DL) transmission. The first AP transmits a second frame to the second AP indicating the time period for DL ​​transmission. A method that includes, The aforementioned time period is determined based on the DL transmission parameters. method.

3. The method according to claim 2, The DL transmission parameters are selected by the second AP from among a plurality of DL transmission parameters. method.

4. A method according to claim 2 or 3, The aforementioned DL transmission parameters are proposed by the second AP for DL ​​transmission. method.

5. A method according to any one of claims 2 to 4, The DL transmission parameters are preferred by the second AP for the DL transmission. method.

6. A method according to any one of claims 2 to 5, The DL transmission parameters include one or more of the following: modulation coding scheme (MCS), bandwidth size, resource unit (RU) size, physical layer protocol data unit (PPDU) type, or number of spatial streams for DL ​​transmission. method.

7. A method according to any one of claims 2 to 6, The second frame further indicates the allocated time for the Transmit Opportunity (TXOP) acquired by the first AP. method.

8. A method according to any one of claims 2 to 7, The second frame further indicates the identifier of the second AP, method.

9. A method according to any one of claims 2 to 8, The DL transmission is a multi-AP transmission including the second AP. method.

10. The method according to claim 9, The multi-AP transmission is initiated by the first AP. method.

11. The method according to claim 9 or 10, Multi-AP transmission includes the first AP, method.

12. A method according to any one of claims 2 to 11, The aforementioned first frame includes a downlink (DL) buffer status report (BSR). method.

13. A method according to claim 12, The aforementioned DL transmission time period is further based on DL BSR, method.

14. The method according to claim 13, The DL BSR indicates the amount of DL traffic buffered by the second AP. method.

15. A method according to any one of claims 2 to 14, The first AP transmits a third frame to the second AP requesting a buffer status report (BSR) from the second AP for the DL transmission. A way to further include that.

16. The first access point (AP) receives a first frame from the second AP indicating a downlink (DL) buffer status report (BSR) for DL ​​transmission. The first AP transmits a second frame to the second AP. A method that includes, The aforementioned second frame is, The allocated time of the transmission opportunity (TXOP) acquired by the first AP, The identifier of the second AP mentioned above, The time period for the DL transmission, The DL transmission parameters of the second AP for the DL transmission are shown below. method.

17. The method according to claim 16, The time period of the second AP for DL ​​transmission and at least one of the DL transmission parameters are determined based on the DL BSR. method.

18. The method according to claim 16 or 17, The DL transmission is a multi-AP transmission performed during the TXOP's allocated time. method.

19. The method according to claim 18, The aforementioned multi-AP transmission is Cooperative Orthogonal Frequency Division Multiple Access (C-OFDMA) transmission. method.

20. The method according to claim 16, The aforementioned DL transmission includes a DL Physical Protocol Data Unit (PPDU), method.

21. The method according to claim 20, The time period for the DL transmission includes the length of the DL PPDU. method.

22. A method according to any one of claims 16 to 21, The DL transmission parameters include one or more of the following: modulation coding scheme (MCS), bandwidth size, resource unit (RU) size, physical layer protocol data unit (PPDU) type, or number of spatial streams for DL ​​transmission. method.

23. The first access point (AP) transmits a first frame indicating the Modulation Coding Scheme (MCS) for DL ​​transmission to the second AP. A method comprising receiving a second frame from the second AP by the first AP, The aforementioned second frame is, The allocated time of the transmission opportunity (TXOP) acquired by the second AP, The time period for the DL transmission within the aforementioned allocated time is indicated, The aforementioned time period is determined based on the MCS. method.

24. The first access point (AP) sends a first frame to the second AP, which contains DL transmission parameters for downlink (DL) transmission. The first AP receives a second frame from the second AP indicating the time period of the DL transmission. A method that includes, The aforementioned time period is determined based on the DL transmission parameters. method.

25. The method according to claim 24, The DL transmission parameters are selected by the first AP from a plurality of DL transmission parameters. method.

26. The method according to claim 24 or 25, The DL transmission parameters are proposed by the first AP for the DL transmission. method.

27. A method according to any one of claims 24 to 26, The DL transmission parameters are determined by the first AP to be suitable for DL ​​transmission. method.

28. A method according to any one of claims 24 to 27, The DL transmission parameters include one or more of the following: modulation coding scheme (MCS), bandwidth size, resource unit (RU) size, physical layer protocol data unit (PPDU) type, or number of spatial streams for DL ​​transmission. method.

29. A method according to any one of claims 1 to 28, The DL transmission parameters include downlink (DL) time resource allocation information or DL ​​frequency resource allocation information for the DL transmission. method.

30. The method according to claim 1, The aforementioned DL time resource allocation information indicates the duration of DL transmission. method.

31. The method according to claim 1, The DL frequency resource allocation information includes the resource unit (RU) size for the DL transmission. method.

32. The method according to claim 1, The duration of the DL transmission is determined based on the DL time resource allocation information or the DL frequency resource allocation information. method.

33. A method according to any one of claims 24 to 32, The second frame further indicates the allocated time of the transmission opportunity (TXOP) acquired by the second AP. method.

34. A method according to any one of claims 1 to 33, The second frame includes a multi-user send request triggered TXOP shared (MU-RTS TXS) trigger frame or a multi-AP trigger frame. method.

35. A method according to any one of claims 24 to 34, The second frame further indicates the identifier of the first AP, method.

36. A method according to any one of claims 24 to 35, The DL transmission is a multi-AP transmission including the first AP. method.

37. The method according to claim 36, The multi-AP transmission is initiated by the second AP. method.

38. The method according to claim 36 or 37, wherein the multi-AP transmission includes the second AP. method.

39. A method according to any one of claims 1 to 38, The multi-AP transmission is a coordinated orthogonal frequency-division multiple access (C-OFDMA) transmission, a coordinated time-division multiple access (C-TDMA) transmission, a coordinated spatial reuse (C-SR) transmission, a coordinated beamforming (C-BF) transmission, or a coordinated joint transmission. method.

40. A method according to any one of claims 1 to 6, The first frame includes a Downlink (DL) Buffer Status Report (BSR), method.

41. A method according to any one of claims 1 to 40, wherein the duration of the DL transmission is further based on the DL BSR, method.

42. The method according to claim 40 or 41, wherein the DL BSR indicates the amount of DL traffic buffered to the first AP. method.

43. A method according to any one of claims 24 to 42, The first AP receives a third frame from the second AP requesting a buffer status report (BSR), method.

44. A method according to any one of claims 1 to 43, The BSR is a Cooperative Orthogonal Frequency Division Multiple Access (C-OFDMA) BSR. method.

45. The method according to claim 43 or 44, The third frame includes a Buffer Status Report Pole (BSRP) trigger frame, a base trigger frame, a pole frame, or a request frame. method.

46. A method according to any one of claims 43 to 45, The first AP transmits the first frame to the second AP in response to the third frame, method.

47. A method according to any one of claims 24 to 46, The aforementioned first frame includes an action frame. method.

48. The method according to claim 25, The aforementioned action frame includes an information element that includes the DL transmission parameters, method.

49. A method according to any one of claims 24 to 27, wherein the first frame includes a quality of service (QoS) null frame or a QoS data frame. method.

50. The method according to claim 49, The QoS null frame or QoS data frame includes an aggregate control (A-Control) field containing the DL transmission parameters, method.

51. A method according to any one of claims 24 to 50, The first AP further includes transmitting a Physical Layer Protocol Data Unit (PPDU) using the DL transmission parameters and during the DL transmission time period, method.

52. The first access point (AP) sends a first frame to the second AP indicating a buffer status report (BSR) for a downlink (DL) transmission. The first AP receives a second frame from the second AP. A method including, The aforementioned second frame is, The allocated time of the transmission opportunity (TXOP) acquired by the second AP, The identifier of the first AP mentioned above, The time period for DL ​​transmission, The DL transmission parameters of the first AP for the DL transmission are shown below. method.

53. The method according to claim 52, The time period of the first AP for DL ​​transmission and at least one of the DL transmission parameters are determined based on the BSR. method.

54. The method according to claim 52 or 53, The DL transmission is a multi-AP transmission performed during the TXOP's allocated time. method.

55. The method according to claim 54, The aforementioned multi-AP transmission is a cooperative orthogonal frequency division multiple access (C-OFDMA) transmission. method.

56. The method according to claim 52, The DL transmission includes the DL Physical Protocol Data Unit (PPDU), method.

57. The method according to claim 56, The time period for the DL transmission includes the length of the DL PPDU. method.

58. A method according to any one of claims 52 to 57, The DL transmission parameters include one or more of the following: modulation coding scheme (MCS), bandwidth size, resource unit (RU) size, physical layer protocol data unit (PPDU) type, or number of spatial streams for DL ​​transmission. method.

59. It can be saved on a computer-readable medium. When executed on a processor, it is configured to perform the method according to any of the above claims, Computer program products.

60. When it was implemented in the first access point, The second AP receives a first frame indicating the Modulation Coding Scheme (MCS) for downlink (DL) transmission. The second AP is sent a second frame. A device configured in such a way, The aforementioned second frame is, The allocated time of the transmission opportunity (TXOP) acquired by the first AP, The time period for DL ​​transmission within the aforementioned allocated time, Show, The aforementioned time period is determined based on the MCS. device.

61. When it was implemented in the first access point, The first access point (AP) receives a first frame from the second AP that contains DL transmission parameters for downlink (DL) transmission. A second frame indicating the time period of the DL transmission is transmitted to the second AP. A device configured in such a way, The aforementioned time period is determined based on the DL transmission parameters. device.

62. When it was implemented in the first access point, A first frame indicating the Modulation Coding Scheme (MCS) for DL ​​transmission is transmitted to the second AP. The second AP receives the second frame. A device configured in such a way, The aforementioned second frame is, The transmission opportunity allocation time (TXOP) acquired by the second AP, The time period for DL ​​transmission within the aforementioned allocated time is indicated, The aforementioned time period is determined based on the MCS. device.

63. When it was implemented in the first access point, A first frame containing DL transmission parameters for downlink (DL) transmission is sent to the second AP. The second AP receives a second frame indicating the time period of the DL transmission. A device configured in such a way, The aforementioned time period is determined based on the DL transmission parameters. device.

Images