Detection operations for relay communication

Abstract

A first station (STA) receives a first frame from a second station. The first frame indicates a first Physical Layer Protocol Data Unit (PPDU) to be transmitted by the second station, wherein the first PPDU is used by the first station to estimate a first channel from the second station to the third station. The first station also requests that, after receiving the first PPDU, it transmit a second frame to a third station. The second frame indicates a second PPDU to be transmitted by the first station to the third station, wherein the second PPDU is used by the third station to estimate a second channel from the first station to the third station. The first station receives the first PPDU from the second station; after receiving the first PPDU, it transmits the second frame to the third station; and after transmitting the second frame, it transmits the second PPDU to the third station.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Application No. 63 / 615,823, filed December 29, 2023, which is incorporated herein by reference in its entirety. Attached Figure Description

[0002] Examples of several embodiments of the various embodiments of this disclosure are described herein with reference to the accompanying drawings.

[0003] Figure 1 An example wireless communication network in which embodiments of the present disclosure may be implemented is shown.

[0004] Figure 2 This is a block diagram showing an example implementation of a station (STA) and access point (AP).

[0005] Figure 3 An example Media Access Control (MAC) frame format is shown.

[0006] Figure 4 An example management frame that can be used as an action frame is shown.

[0007] Figure 5 An example control frame that can be used as a trigger frame is shown.

[0008] Figure 6 An example data frame that can be used as a Quality of Service (QoS) empty frame is shown.

[0009] Figure 7 An example format of the Physical Layer (PHY) Protocol Data Unit (PPDU) is shown.

[0010] Figure 8 An example of a relay architecture below 1 GHz (S1G) is shown.

[0011] Figure 9 An example of a source-relay-destination link is shown.

[0012] Figure 10 This is an example of a relay that does not have Transmission Opportunity (TXOP) protection.

[0013] Figure 11 An example of a Request to Send (RTS) / Clear to Send (CTS) procedure is shown.

[0014] Figure 12 This is an example of a relay with TXOP protection.

[0015] Figure 13 The example empty data PPDU (NDP) announcement (NDPA) frame format is shown.

[0016] Figure 14 An example Enhanced High Throughput (EHT) Compressed Beamforming / Channel Quality Indication (CQI) frame is shown.

[0017] Figure 15 An example EHT non-trigger-based (non-TB) probe sequence is shown.

[0018] Figure 16 An example of an EHT-based trigger-based (TB) probe sequence is shown.

[0019] Figure 17 An example probe program for relaying is shown.

[0020] Figure 18 This is an example illustrating a detection procedure for relay communication according to an embodiment.

[0021] Figure 19 This is an example illustrating a detection procedure for relay communication according to an embodiment.

[0022] Figure 20 This is an example illustrating a detection procedure for relay communication according to an embodiment.

[0023] Figure 21 This is an example illustrating a detection procedure for relay communication according to an embodiment.

[0024] Figure 22 This is an example illustrating a detection procedure for relay communication according to an embodiment.

[0025] Figure 23 An example control frame that can be used according to an embodiment is shown.

[0026] Figure 24 An example control frame that can be used according to an embodiment is shown.

[0027] Figure 25 Example action frames that can be used according to the embodiments are shown.

[0028] Figure 26 Example action frames that can be used according to the embodiments are shown.

[0029] Figure 27 An example process according to an embodiment of this disclosure is shown.

[0030] Figure 28 An example process according to an embodiment of this disclosure is shown.

[0031] Figure 29 An example process according to an embodiment of this disclosure is shown. Detailed Implementation

[0032] In this disclosure, various embodiments are presented as examples of how the disclosed techniques can be implemented and / or how the disclosed techniques can be practiced in environments and scenarios. It will be apparent to those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention. Alternative embodiments will become apparent to those skilled in the art upon reading this specification. Embodiments of the invention are not to be limited to any of the exemplary embodiments described. Embodiments of this disclosure will be described with reference to the accompanying drawings. Limitations, features, and / or elements from the disclosed example embodiments may be combined to create additional embodiments within the scope of this disclosure. Any figures highlighting functionality and advantages are given for illustrative purposes only. The disclosed architecture is flexible and configurable enough that it can be utilized in ways other than those shown. For example, any actions listed in any flowchart may be reordered or used only optionally in certain embodiments.

[0033] The embodiments can be configured to operate as needed. When certain criteria are met, the disclosed mechanisms can be executed, for example, in stations, access points, radio environments, networks, or combinations thereof. Example criteria may be based at least in part on, for example, wireless device or network node configuration, traffic load, initial system settings, packet size, service characteristics, or combinations thereof. Various example implementations can be applied when one or more criteria are met. Therefore, example embodiments that selectively implement the disclosed protocols can be implemented.

[0034] In this disclosure, the terms “a” and “an” and similar phrases will be interpreted as “at least one” and “one or more”. Similarly, any term ending with the suffix “(s)” will be 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 an example of one of a variety of suitable possibilities that may or may not be used in one or more of the various embodiments. As used herein, the terms “comprises” and “composes of” enumerate one or more components of the element being described. The terms “comprises” and “includes” are interchangeable and do not exclude the inclusion of unlisted components in the element being described. In contrast, “composes of” provides a complete enumeration of the one or more components of the element being described. As used herein, the term “based on” can be interpreted as “at least partially based on” rather than, for example, “based on only”. As used herein, the term “and / or” indicates any possible combination of the enumerated elements. For example, "A, B and / or C" can mean A; B; C; A and B; A and C; B and C; or A, B and C.

[0035] If A and B are sets, and every element of A is also an element 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 phrase “based on” (or equivalently “at least based on”) indicates that the phrase following the term “based on” is an example of one of a variety of suitable possibilities that may or may not be used in one or more of the various embodiments. The phrase “in response to” (or equivalently “at least in response to”) indicates that the phrase following the phrase “in response to” is an example of one of a variety of suitable possibilities that may or may not be used in one or more different embodiments. The phrase “depends on” (or equivalently “at least depends on”) indicates that the phrase following the phrase “depends on” is an example of one of a variety of suitable possibilities that may or may not be used in one or more different embodiments. The phrase “adopts / uses” (or equivalently “at least adopts / uses”) indicates that the phrase following the phrase “adopts / uses” is an example of one of a variety of suitable possibilities that may or may not be used in one or more different embodiments.

[0036] The term "configured" can refer to the capabilities of a device, whether the device is in an operational or non-operational state. "Configured" can refer to specific settings within the device that affect its operational characteristics, regardless of whether the device is in an operational or non-operational state. In other words, hardware, software, firmware, registers, memory values, etc., can be "configured" within the device to provide specific characteristics to the device, whether the device is in an operational or non-operational state. Similarly, the term "control messages generated in the device" can mean that the control messages have parameters that can be used to configure specific characteristics in the device or to perform certain actions in the device, regardless of whether the device is in an operational or non-operational state.

[0037] In this disclosure, a parameter (or equivalently referred to as a field or information element: IE) may include 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, and 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 an example embodiment, when one or more messages / frames include multiple parameters, this means that a parameter among the multiple parameters is in at least one of the one or more messages / frames, but not necessarily in every one of the one or more messages / frames.

[0038] Many of the proposed features are described as optional using the word "may" or parentheses. For brevity and readability, this disclosure does not explicitly describe every permutation that can be obtained by selecting from the group of optional features. This disclosure should be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features can be embodied in seven different ways: having only one of the three possible features, having any two of the three possible features, or having three of the three possible features.

[0039] Many elements described in the disclosed embodiments can be implemented as modules. A module is defined herein as an element that performs the defined function and has the defined interface to other elements. Modules described in this disclosure can be implemented in hardware, software combined with hardware, firmware, wet hardware (e.g., hardware with biological elements), or combinations thereof, all of which are behaviorally equivalent. For example, a module can be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab, etc.) or a modeling / simulation program (such as Simulink, Stateflow, GNU Octave, or LabVIEW MathScript). It is possible to implement modules 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, C, and C++. FPGAs, ASICs, and CPLDs are typically programmed using hardware description languages ​​(HDLs), such as VHSIC Hardware Description Language (VHDL) or Verilog, which configure connections between internal hardware modules with limited functionality on the programmable device. The aforementioned techniques are often used in combination to achieve the desired result of functional modules.

[0040] Figure 1 An example wireless communication network in which embodiments of the present disclosure may be implemented is shown.

[0041] like Figure 1 As shown, an example wireless communication network may include an IEEE 802.11 (WLAN) infrastructure network 102. WLAN infrastructure network 102 may include one or more Basic Service Sets (BSS) 110 and 120 and a Distribution System (DS) 130.

[0042] BSS 110-1 and 110-2 each include a set of access points (APs or AP STAs) and at least one station (STA or non-AP STA). For example, BSS 110-1 includes AP 104-1 and STA 106-1, and BSS 110-2 includes AP 104-2 and STAs 106-2 and 106-3. The APs and at least one STA in the BSS perform association procedures for communicating with each other.

[0043] DS 130 can be configured to connect BSS 110-1 and BSS 110-2. Therefore, DS 130 can enable Extended Service Set (ESS) 150. Within ESS 150, APs 104-1 and 104-2 are connected via DS 130 and can have the same Service Set Identifier (SSID).

[0044] The WLAN infrastructure network 102 can be coupled to one or more external networks. For example, such as Figure 1 As shown, WLAN infrastructure network 102 can be connected to another network 108 (e.g., 802.X) via portal 140. Portal 140 can act as a bridge connecting DS 130 of WLAN infrastructure network 102 to the other network 108.

[0045] Figure 1 The example wireless communication network shown may further include one or more self-organizing networks or independent BSSs (IBSSs). A self-organizing network or IBSS is a network of multiple STAs included within each other's communication range. The multiple STAs are configured such that they can communicate with each other using direct peer-to-peer communication (i.e., without through an AP).

[0046] For example, in Figure 1 In this configuration, STAs 106-4, 106-5, and 106-6 can be configured to form a first IBSS 112-1. Similarly, STAs 106-7 and 106-8 can be configured to form a second IBSS 112-2. Since an IBSS does not include an AP, it does not include a centralized management entity. Instead, STAs within an IBSS are managed in a distributed manner. STAs forming an IBSS can be fixed or mobile.

[0047] A STA, serving as a predefined functional medium, may include a Media Access Control (MAC) layer conforming to the IEEE 802.11 standard. The physical layer interface of the radio medium can be used in both AP and non-AP stations (STAs). STAs may also be referred to using various other terms, including mobile terminal, radio device, radio transmit / receive unit (WTRU), user equipment (UE), mobile station (MS), mobile subscriber unit, or user. For example, the term "user" may be used to refer to a STA participating in uplink multi-user multiple-input multiple-output (MU MIMO) and / or uplink orthogonal frequency division multiple access (OFDMA) transmissions.

[0048] Physical Layer (PHY) Protocol Data Units (PPDUs) can be composite structures, comprising a PHY preamble and a payload in the form of a PLCP Service Data Unit (PSDU). For example, a PSDU may include a PHY Convergence Protocol (PLCP) preamble and 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 subsequent data in the PSDU. When the PPDU is transmitted over a bonded channel (a channel formed by channel bonding), the preamble field can be copied and transmitted in each of the multiple component channels. The PHY preamble may include both a traditional portion (or "traditional preamble") and a non-traditional portion (or "non-traditional preamble"). The traditional preamble can be used for purposes such as packet detection, automatic gain control, and channel estimation. The traditional preamble is also typically used to maintain compatibility with legacy devices. The format, encoding, and information provided in the non-traditional portion of the preamble are based on the specific IEEE 802.11 protocol to be used for transmitting the payload.

[0049] A frequency band can include one or more sub-bands or frequency channels. For example, PPDUs conforming to IEEE 802.11n, 802.11ac, 802.11ax, and / or 802.11be standard modifications can be transmitted in 2.4 GHz, 5 GHz, and / or 6 GHz bands, each band can be divided into multiple 20 MHz channels. PPDUs can be transmitted through physical channels with a minimum bandwidth of 20 MHz. Larger channels can be formed through channel bonding. For example, multiple 20 MHz channels can be bonded together to transmit PPDUs through physical channels with bandwidths of 40 MHz, 80 MHz, 160 MHz, or 520 MHz.

[0050] Figure 2 This is a block diagram illustrating an example implementation of STA 210 and AP 260. (See diagram for example.) Figure 2As shown, STA 210 may include at least one processor 220, memory 230, and at least one transceiver 240. AP 260 may include at least one processor 270, memory 280, and at least one transceiver 290. Processors 220 / 270 may be operatively connected to memory 230 / 280 and / or transceiver 240 / 290.

[0051] Processors 220 / 270 can implement the functions of the PHY layer, MAC layer, and / or logical link control (LLC) layer of the corresponding device (STA 210 or AP 260). Processors 220 / 270 may include one or more processors and / or one or more controllers. For example, 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), logic circuitry, or a chipset.

[0052] Memory 230 / 280 may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium, and / or other storage units. Memory 230 / 280 may include one or more non-transitory 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 processor 220 / 270 or external to processor 220 / 270. Memory 230 / 280 may be operatively connected to processor 220 / 270 in various ways known in the art.

[0053] Transceiver 240 / 290 can be configured to transmit / receive radio signals. In embodiments, transceiver 240 / 290 can implement the PHY layer of the corresponding device (STA 210 or AP 260). In embodiments, STA 210 and / or AP 260 can be multi-link devices (MLDs), which are devices capable of operating on multiple links defined by the IEEE 802.11 standard. Therefore, STA 210 and / or AP 260 can each implement multiple PHY layers. One or more of transceivers 240 / 290 can be used to implement multiple PHY layers.

[0054] Figure 3An example format for MAC frame 300 is shown. In operation, the STA can construct a subset of MAC frames for transmission and can decode the received subset of MAC frames during verification. The specific subset of frames that the STA can construct and / or decode can be determined by the functions supported by the STA. The STA can verify received MAC frames using the Frame Check Sequence (FCS) contained in the frame and can interpret certain fields based on the MAC header of all frames.

[0055] like Figure 3 As shown, MAC frame 300 includes a MAC header, a variable-length frame body, and a frame check sequence (FCS).

[0056] The MAC header includes a frame control field, an optional duration / ID field (not in PS-Poll frames), an address field, an optional sequence control field, an optional QoS control field (only in QoS data frames), and an optional high throughput (HT) control field (only in +HTC frames).

[0057] The frame control field includes the following subfields: protocol version, type, subtype, to DS, from DS, more fragments, retry, power management, more data, protected frames, and high throughput control (+HTC).

[0058] The size and placement of the protocol version subfield remain unchanged across all revisions of the IEEE 802.11 standard. For MAC frames, the value of the protocol version subfield is 0.

[0059] The Type and Subtype subfields together identify the function of a MAC frame. There are three frame types: Control, Data, and Management. Each frame type has several defined subtypes. Bits within the Subtype subfield are 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, i.e., a data frame that includes the QoS Control field in its MAC header. When set to 1 in the Data subtype, the second MSB of the Subtype field, bit 6 (B6) of the Frame Control field, indicates a data frame that does not include a Frame Body field.

[0060] The ToDS subfield indicates whether the data frame is destined for DS. The FromDS subfield indicates whether the data frame originated from DS.

[0061] In all data or management frames that have another fragment following the MAC Service Data Unit (MSDU) or MAC Management Protocol Data Unit (MMPDU) carried in a MAC frame, the More Fragments subfield is set to 1. In all other frames in which the More Fragments subfield exists, it is set to 0.

[0062] In any data or management frame that is a retransmission of an earlier frame, the retry subfield is set to 1. In all other frames in which the retry subfield exists, it is set to 0. The receiving STA uses this indication to assist in its process of eliminating duplicate frames. These rules do not apply to frames sent by the STA according to the block protocol.

[0063] The power management subfield is used to indicate the power management mode of the STA.

[0064] The More Data subfield in Power Saving (PS) mode indicates to the STA that a bufferable unit (BU) is buffered at the AP for the STA. The More Data subfield is valid in separately addressed data or management frames transmitted from the AP to the STA in PS mode. The More Data subfield is set to 1 to indicate that at least one additional buffered BU exists for the STA.

[0065] If the frame body field contains information that has been processed by an encryption encapsulation algorithm, then the protected frame subfield is set to 1.

[0066] The +HTC subfield indicates that MAC frame 300 contains the HT control field. Frames containing the HT control field are called +HTC frames. Control wrapper frames are +HTC frames.

[0067] The Duration / ID field in the MAC header indicates different content depending on the frame type and subtype, as well as the QoS capabilities of the sending 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 has transmitted a frame in 14 least significant bits (LSBs), and both most significant bits (MSBs) are set to 1. In other frames transmitted by the STA, the Duration / ID field contains a duration value (in microseconds) for the receiver to use to update the Network Allocation Vector (NAV). The NAV is a counter indicating to the STA the amount of time it must delay access to the shared medium.

[0068] A MAC frame 300 format may contain up to four address fields. These fields are used to indicate the Basic Service Set Identifier (BSSID), source address (SA), destination address (DA), sender address (TA), and receiver address (RA). Some frames may not contain certain address fields. The use of certain address fields can be specified by the relative order of address fields (1-4) within the MAC header, regardless of the address type present in those fields. Specifically, address 1 always identifies the intended receiver of the frame, and address 2 (if present) always identifies the sender of the frame.

[0069] The sequence control field includes two subfields: a sequence number subfield and a fragment number subfield. In a data frame, the sequence number subfield indicates the sequence number of the MSDU (if not in an aggregated MSDU (A-MSDU)) or A-MSDU. In a management frame, the sequence number subfield indicates the sequence number of the frame. The fragment number subfield indicates the number of each fragment of the MSDU or MMPDU. In the first or only fragment of an MSDU or MMPDU, the fragment number is set to 0 and increments by one for each subsequent fragment of that MSDU or MMPDU. In a MAC Protocol Data Unit (MPDU) containing an A-MSDU or in an MPDU containing an unfragmented MSDU or MMPDU, the fragment number is set to 0. The fragment number remains constant throughout all retransmissions of the fragment.

[0070] The QoS control field identifies the service category (TC) or service flow (TS) to which the MAC frame 300 belongs. The QoS control field can also indicate various other QoS-related, A-MSDU-related, and mesh-related information about the frame. This information can vary depending on the frame type, frame subtype, and the type of transport STA. The QoS control field exists in all data frames where the QoS subfield of the subtype subfield is equal to 1.

[0071] The HT control field exists in QoS data, QoS empty, and management frames, as determined by the +HTC subfield of the frame control field. The control frame subtype containing the HT control field is the control wrapper frame. A control frame described as +HTC (e.g., Request to Send (RTS) +HTC, Allow to Send (CTS) +HTC, Block Ack +HTC, or Block Ack Req +HTC frame) means that the control frame is carried using a control wrapper frame.

[0072] The frame body field is a variable-length field that contains information specific to each frame type and subtype. It can include one or more MSDUs or MMPDUs. The minimum length of the frame body is 0 octets.

[0073] The FCS field contains a 32-bit Cyclic Redundancy Check (CRC) code. The FCS field value is calculated on all fields of the MAC header and frame body.

[0074] Figure 4 An example management frame 400 that can be used as an action frame is shown. In the example, management frame 400 includes a MAC header, a variable-length frame body, and a frame check sequence (FCS). The MAC header includes a frame control field, a duration field, an address 1 field, an address 2 field, an address 3 field, a sequence control field, and an optional HT control field. The presence of the HT control field is determined by the setting of the +HTC subfield of the frame control field.

[0075] like Figure 4 As shown, when used as an action frame, the frame body of a management frame includes an action field, vendor-specific elements, a management message integrity code element (MME), a message integrity code (MIC), and an authenticated mesh peer exchange element.

[0076] The action field includes a category field and an action details field. The action field provides a mechanism for specifying extended management actions. The category field indicates the category of the action frame. The action details field contains details of the action requested by the action frame. For example, the action frame could be a common action frame. Figure 4 As shown, in the common action frame format, the action detail field includes the common action field in an octet immediately following the category field, followed by the variable-length common action detail field.

[0077] Optionally, one or more supplier-specific elements may exist. These elements do not exist when the category subfield of the action field is supplier-specific.

[0078] When negotiating management frame protection, the MME is present, the frame is a group-addressed robust action frame, and (MBSS only) the action frame's class does not support group-addressed privacy as indicated by the class value; otherwise, it is not present.

[0079] If a shared pair master key (PMK) exists between the sender and receiver of this frame, then the MIC element exists in the self-protection action frame; otherwise, it does not exist.

[0080] If the shared PMK exists between the sender and receiver of this frame, then the authenticated mesh peer-to-peer exchange element exists in the self-protection action frame; otherwise, it does not exist.

[0081] Figure 5 The example format of trigger frame 500 is shown. An AP can use trigger frame 500 to allocate resources to one or more STAs and request one or more TB PPDU transmissions from one or more STAs. Trigger frame 500 may also carry additional information required by a STA to transmit a TB PPDU to the AP.

[0082] like Figure 5 As shown, the trigger frame 500 includes a frame control field, a duration field, a receiver address (RA) field, a transmitter address (TA) field, a general information field, a user information list field, a padding field, and an FCS field.

[0083] The frame control field includes the following subfields: protocol version, type, subtype, to DS, from DS, more fragments, retry, power management, more data, protected frames, and +HTC.

[0084] The duration field indicates various things depending on the frame type and subtype, as well as the QoS capabilities of the sending STA. For example, in a control frame of the Power Saving Polling (PS-Poll) subtype, the duration field carries the association identifier (AID) of the STA that has transmitted the frame in 14 least significant bits (LSBs), and both most significant bits (MSBs) are set to 1. In other frames transmitted by the STA, the duration field contains a duration value (in microseconds) for the receiver to use to update the Network Allocation Vector (NAV).

[0085] The RA field is the address of the STA intended to receive an incoming transmission from the transmission station. If trigger frame 500 is addressed to an STA belonging to a single BSS, then the TA field is the address of the STA transmitting trigger frame 500. If trigger frame 500 is addressed to an STA from at least two different BSSs in a set of multiple BSSIDs, then the TA field is the BSSID being transmitted.

[0086] The General Information field specifies the trigger frame type of trigger frame 500, the transmission power of trigger frame 500 in dBm, and several key parameters of the TB PPDU transmitted by the STA in response to trigger frame 500. The trigger frame type used by the AP to receive QoS data using the UL MU is called the Basic Trigger Frame. Non-EHT, non-AP HE STAs interpret the General Information field as an HE variant. If B54 and B55 in the General Information field are equal to 1, then non-AP EHT STAs interpret the General Information field as an HE variant; otherwise, they interpret it as an EHT variant. The HE variant General Information field and the EHT variant General Information field use the same encoding method for trigger type, UL length, additional TF, required CS, LDPC additional symbol segment, AP TX power, pre-FEC padding factor, PE disambiguation, and trigger-related General Information subfields.

[0087] The user information list field contains zero or more user information fields. There are three variations of the user information field: specific user information field, EHT variant user information field, and HE variant user information field.

[0088] The Special User Information field is a user information field that does not carry user-specific information but carries extended general information not provided in the General Information field. If the Special User Information field is included in the trigger frame, the Special User Information Field Flag subfield of the EHT Variant General Information field is set to 0; otherwise, it is set to 1. The Special User Information field is identified by the AID12 value 2007 and may optionally exist in the trigger frame generated by the EHT AP. The Special User Information field (if present) immediately follows the General Information field of the trigger frame and carries information for the U-SIG field of the requested EHT TB PPDU. The PHY Version Identifier subfield indicates the PHY version of the requested TB PPDU, which is not an HE TB PPDU. For EHT, the PHY Version Identifier subfield is set to 0. Other values ​​from 1 to 7 are reserved. The UL Bandwidth (BW) Extension subfield, together with the UL BW subfield in the General Information field, indicates the bandwidth of the requested TB PPDU from the addressed ELT STA (i.e., the bandwidth in the U-SIG field of the EHT TB PPDU). The EHT Spatial Multiplexing n subfield carries the value to be included in the corresponding Spatial Multiplexing n subfield of the U-SIG field in the EHT TB PPDU. The U-SIG Ignore and Verify subfield carries the value to be included in the Ignore and Verify subfield of the U-SIG field in the requested EHT TB PPDU. The presence and length of the Trigger-Related User Information subfield in the Special User Information field depend on the variant of the trigger frame.

[0089] The EHT variant user information field contains user information fields for each STA addressed in trigger frame 500. Each STA user information field specifically includes the AID12 subfield, RU allocation subfield, UL FEC coding type subfield, UL EHT-MCS subfield, reserved subfield, spatial stream (SS) allocation / RA-RU information subfield, UL target received power subfield, and power saving (PS) 160 subfield for use by the STA in the TB PPDU transmitted in response to trigger frame 500, as well as trigger-related user information subfields. The RU allocation subfield in the EHT variant user information field (not a MU-RTS trigger frame), the UL BW subfield in the general information field, the BW extension subfield in the specific user information field, and the PS160 subfield in the EHT variant user information field identify the size and location of the RU or MRU. The B0 value of the PS160 subfield and RU allocation subfield indicates the 80 MHz frequency subblock where the RU or MRU is located, for 26-mode RU, 52-mode RU, 106-mode RU, 242-mode RU, 484-mode RU, 996-mode RU, 52+26-mode RU, and 106+26-mode RU. The PS160 subfield value indicates the 160 MHz segment where the RU or MRU is located, for 2×996-mode RU, 996+484-mode MRU, and 996+484+242-mode MRU. The UL FEC coding type subfield of the User Information field indicates the code type of the requested EHT TB PPDU. The UL FEC coding type subfield is set to 0 to indicate BCC and set to 1 to indicate LDPC. The UL EHT-MCS subfield of the User Information field indicates the EHT-MCS of the requested EHT TB PPDU. The SS allocation subfield of the EHT variant user information field indicates the spatial flow of the requested EHT TB PPDU. The UL target received power subfield indicates the expected received signal power, measured at the AP's antenna connector and averaged by the antenna, for the EHT portion of the EHT TB PPDU transmitted on the assigned RU. The AP can use the trigger-related user information subfield to specify the preferred access class (AC) for each STA. The preferred AC setting can be determined by the minimum priority AC traffic transmitted by the participating STAs. The AP determines the list of participating STAs, and the BW, MCS, RU allocation, SS allocation, Tx power, preferred AC, and maximum duration for each participating STA's TB PPDU. The RA-RU information subfield is retained in the EHT variant user information field.

[0090] The padding field is optionally present in frame 400 to extend the frame length, thereby providing the receiving STA with sufficient time to prepare a transmission response after receiving the frame at a SIFS interval. The padding field (if present) is at least two octets in length and is set to all 1s.

[0091] The STA uses the FCS field to verify received frames and interprets certain fields based on the frame's MAC header.

[0092] Figure 6 Example data frame 600, which can be used as a QoS empty frame, is shown. A QoS empty frame is a QoS data frame with an empty frame body. A QoS empty frame includes a QoS control field and an optional HT control field, which may contain a Buffer Status Report (BSR) control subfield. A QoS empty frame indicating buffer status information can be transmitted from a STA to an AP.

[0093] QoS control fields may include a Service Identifier (TID) subfield, an Acknowledgment (Ack) Policy Indicator subfield, and a Queue Size subfield (or a Transmission Opportunity (TXOP) Duration Request subfield).

[0094] The TID subfield identifies the TC or TS requesting a TXOP by setting the requested TXOP duration or queue size subfield. The encoding of the TID subfield depends on the access policy (e.g., values ​​0 to 7 are allowed for Enhanced Distributed Channel Access (EDCA) access policies to identify the user priority of the TC or TS).

[0095] The ack policy indicator subfield and other information identify the ack policy to be followed after the MPDU is delivered (e.g., normal ack, implicit block ack request, no ack, block ack, etc.). The queue size subfield is an 8-bit field that indicates the amount of buffered traffic at the STA used to transmit to the AP identified by the receiver address of the frame containing this subfield for a given TC or TS. The queue size subfield is present in QoS empty frames transmitted by the STA when bit 4 of the QoS control field is set to 1. The AP can use the information contained in the queue size subfield to determine the TXOP duration assigned to the STA or to determine the uplink (UL) resources assigned to the STA.

[0096] In frames sent to or from inefficient (non-HE) STAs, the following rules may be applied to queue size values: - The queue size value is the approximate total size of all MSDUs and A-MSDUs (excluding MSDUs or A-MSDUs contained in this QoS data frame) buffered at the STA in the delivery queue for MSDUs and A-MSDUs, rounded up to the nearest multiple of 256 octets, and expressed in units of 256 octets, where the TID value is equal to the value indicated in the TID subfield of the QoS control field.

[0097] - A queue size value of 0 is only used to indicate that there is no buffered traffic in the queue used for the specified TID.

[0098] - For all sizes greater than 64,768 octets, use a queue size value of 254.

[0099] - The queue size value of 255 is used to indicate an unspecified or unknown size.

[0100] In frames sent from HE STA to HE AP, the following rules can be applied to queue size values.

[0101] Queue size value QS It is the approximate total size of all MSDUs and A-MSDUs buffered at the STA in the delivery queue for MSDUs and A-MSDUs (including MSDUs or A-MSDUs contained in the same PSDU as the frame containing the queue size subfield), represented in octets, where the TID value is equal to the value indicated in the TID subfield of the QoS control field.

[0102] The queue size subfield includes the scaling factor subfield in bits B14 to B15 of the QoS control field and the unscaled value in bits B8 to B13 of the QoS control field. UV The scaling factor subfield provides the scaling factor. SF .

[0103] STA receives data containing scaling factors SF and unscaled values UV Get queue size from QoS control field QS ,as follows: QS = 16 × UV ,if SF Equal to 0; 1024 + 256 × UV ,if SF It equals 1; 17,408 + 2048 × UV ,if SF It equals 2; 148 480 + 32 768 × UV,if SF Equal to 3 and UV Less than 62; >2 147 328, if SF Equal to 3 and UV Equals 62; not specified or unknown ,if SF Equal to 3 and UV It equals 63.

[0104] The requested TXOP duration subfield, which may be included instead of the queue size subfield, indicates to the sending STA the duration, in 32 microseconds (µs), required for the next TXOP for the specified TID. The requested TXOP duration subfield is set to 0 to indicate that no TXOP is requested for the specified TID in the current service period (SP). The requested TXOP duration subfield is set to a non-zero value to indicate the requested TXOP duration in increments of 32 microseconds within the range of 32 microseconds to 8160 microseconds.

[0105] HT control fields may include aggregate control (A-control) subfields. A-control subfields may include control list subfields, which may include one or more control subfields.

[0106] The control subfield can be a BSR control subfield, which can contain buffer status information for UL MU operations. The BSR control subfield can be formed from the following: the Access Class Index (ACI) bitmap subfield of the HT control field, the ΔTID subfield, the ACI high subfield, the scaling factor subfield, the queue size high subfield, and the queue size full subfield.

[0107] The ACI bitmap subfield indicates the access category for reporting buffer status (e.g., B0: Best Effort (AC_BE); B1: Background (AC_BK); B2: Video (AC_VI); B3: Voice (AC_VO), etc.). Each bit of the ACI bitmap subfield is set to 1 to indicate that the buffer status of the corresponding AC is included in the queue size full subfield, and is otherwise set to 0. However, if the ACI bitmap subfield is 0 and the ΔTID subfield is 3, then the buffer status of all 8 TIDs is included.

[0108] The values ​​of the ΔTID subfield and the ACI bitmap subfield indicate the number of TIDs that the STA is reporting in the buffer state.

[0109] The ACI high subfield indicates the ACI of the AC indicated by the BSR in the queue size high subfield. The ACI to AC mapping is defined as ACI value 0 mapping to AC_BE, ACI value 1 mapping to AC_BK, ACI value 2 mapping to AC_VI, and ACI value 3 mapping to AC_VO.

[0110] The scaling factor subfield indicates the units of the queue size height and the queue size full subfield. SF It is represented by an octet.

[0111] The queue size high subfield indicates the amount of buffered traffic for the AC identified by the ACI high subfield. SF The octet is intended for use with STAs identified by the receiver address of a frame containing the BSR control subfield.

[0112] The queue size full subfield indicates the amount of buffered traffic for all ACs, identified by the ACI bitmap subfield. SF The octet is intended for use with STAs identified by the receiver address of a frame containing the BSR control subfield.

[0113] The queue size values ​​in the queue size high and queue size full subfields are the total size of all MSDUs and A-MSDUs buffered at the STA in the delivery queues for MSDUs and A-MSDUs associated with the AC, as specified in the ACI high and ACI bitmap subfields respectively, rounded up. SF The closest multiple of an octet.

[0114] The queue size value of 254 in both the queue size high and queue size full subfields indicates that the amount of buffered traffic is greater than 254 × SF Eight-bit byte. The queue size value of 255 in both the queue size high and queue size full subfields indicates that the amount of buffered traffic is unspecified or unknown. The queue size value of a QoS data frame containing fragments can remain constant, even if the amount of queued traffic changes as consecutive fragments are transmitted.

[0115] 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 transfer MSDUs to the peer MAC entity. This asynchronous MSDU transfer is performed on a connectionless basis.

[0116] Figure 7 The example format of a PPDU is shown. As shown in the figure, a PPDU may include a PHY preamble, a PHY header, a PSDU, and a tail and padding bits.

[0117] A PSDU may include one or more MPDUs, such as a QoS data frame, an MMPDU, a MAC control frame, or a QoS empty frame. When an MPDU carries a QoS data frame, the frame body of the MPDU may include an MSDU or an A-MSDU.

[0118] By default, MSDU delivery is done on a best-effort basis. That is, there is no guarantee that the transmitted MSDU will be successfully delivered. However, QoS facilities use Service Identifiers (TIDs) to specify differentiated services based on each MSDU.

[0119] The STA can differentiate MSDU delivery based on the specified service category (TC) or service flow (TS) of each MSDU. The MAC sublayer entity determines the user priority (UP) of the MSDU based on the TID value provided with the MSDU. The QoS facility supports eight UP values. The UP values ​​range from 0 to 7 and form an ordered priority sequence, where 1 is the lowest value, 7 is the highest value, and 0 falls between 2 and 3.

[0120] MSDUs with a specific UP are referred to as belonging to the service class with that UP. The UP can be provided directly in the UP parameters at the Media Access Control Service Access Point (MAC SAP) along with each MSDU. A-MPDUs can include MPDUs with different TID values.

[0121] The STA can deliver Buffer Status Reports (BSRs) to help the AP allocate UL MU resources. The STA can deliver a BSR implicitly (unrequested BSR) in the QoS control field or BSR control subfield of any frame transmitted to the AP, or explicitly (requested BSR) in a frame sent to the AP in response to a BSRP trigger frame.

[0122] 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, ΔTID, high-priority AC, and both queue sizes.

[0123] The STA can report the buffer status of transmitted QoS empty frames and QoS data frames to the AP in the QoS control field, and report the buffer status of transmitted QoS empty frames, QoS data frames and management frames in the BSR control subfield (if present), as defined below.

[0124] 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 empty frame; the STA can set the queue size subfield to 255 to indicate an unknown / unspecified queue size for the TID. The STA can aggregate multiple QoS data frames or QoS empty frames in the A-MPDU to report the queue size for different TIDs.

[0125] If the AP has indicated that it supports receiving the BSR control subfield, then the STA can report the buffer status in the BSR control subfield of the transmitted frame.

[0126] The High Efficiency (HE) STA 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 an unknown / unspecified queue size for the AC.

[0127] The HE STA can report the queue size of the AC, as indicated by the ACI bitmap subfield, in the queue size full subfield of the BSR control subfield. The STA can set the queue size full subfield to 255 to indicate those ACs with unknown / unspecified BSRs.

[0128] A multi-link device (MLD) is an entity capable of managing communication on multiple links. An MLD can be a logical entity and can have more than one affiliated station (STA). An MLD can be an access point MLD (AP MLD), where the STAs affiliated with the MLD are APSTAs (or APs). An MLD can also be a non-access point MLD (non-AP MLD), where the STAs affiliated with the MLD are non-AP STAs (or STAs).

[0129] Depending on the capabilities of both the communication AP MLD and non-AP MLD, communication across different frequency bands / channels can occur simultaneously or at different times.

[0130] MLDs can have a single MAC service access point (MAC-SAP) that includes MAC data services down to the LLC layer. MLDs can support multiple MAC sub-layers coordinated through sub-layer management entities (SMEs). Each APSTA (or non-AP STA) attached to an AP MLD (or non-AP MLD) has a different MAC address within the MLD.

[0131] The SME is responsible for coordinating the MAC sublayer management entity (MLME) of the MLD's affiliated STA to maintain a single robust Secure Network Association (RSNA) key management entity and a single IEEE 802.1X authenticator or provider for multi-link operation (MLO).

[0132] Multi-Link Operation (MLO) procedures allow a pair of MLDs to discover, synchronize, (de-)authenticate, (re)associate, disassociate, and manage resources on any common frequency band or channel supported by both MLDs. The authenticator and MAC-SAP of an AP MLD can be identified by the same AP MLD MAC address. The supplier and MAC-SAP of a non-AP MLD can be identified by the same non-AP MLD MAC address.

[0133] Figure 8 An example sub-1 GHz (S1G) relay architecture 800 is shown. This example S1G relay architecture 800 can be an example of S1G relay operation as defined in Section 10.54.1 of the IEEE 802.11 draft standard “IEEE P802.11-REVme™ / D2.1, January 2023”. Figure 8 As shown, the example S1G trunk architecture 800 may include root AP 810, trunks 820, 830 and 840, and STAs 850, 860, 870, 880 and 890.

[0134] S1G trunking is a mechanism used to extend the coverage area of ​​an AP (referred to as the root AP). In example S1G trunking architecture 800, the S1G trunking mechanism is used to extend the coverage area of ​​the root AP 810.

[0135] like Figure 8 As shown, S1G relays 820, 830, and 840 may each include a relay AP, a relay STA, and a relay function. The relay STA communicates with the upper BSS, while the relay AP communicates with the lower BSS. The relay function performs local reception or selective forwarding of MSDUs between the relay STA and the relay AP based on the destination address. In the example, relays 820 and 830 are associated with root AP 810. Relay 840 may be associated with relay 820. In the example, STA 850 is associated with relay 820. STAs 860 and 870 may be associated with relay 840. STAs 880 and 890 may be associated with relay 830.

[0136] In the example, frames from STA 850 are forwarded to root AP 810 via the relay function of relay 820 (from relay AP to relay STA). Conversely, frames from root AP 810 are forwarded to STA 850 via the relay function of relay 820 (from relay STA to relay AP). Similarly, STAs 880 and 890 can communicate with root AP 810 in both directions (e.g., uplink and downlink) via relay 830. On the other hand, STAs 860 and 870 can continuously communicate with root AP 810 using relays 840 and 820.

[0137] Figure 9 Example 900 of a source-relay-destination link is shown. Figure 9 As shown, Example 900 may include STA 910 as a source STA, STA 920 as a destination STA, and relay 930.

[0138] STA 910 can be a non-AP STA or an AP STA. Similarly, STA 920 can be a non-AP STA or an AP STA. Relay 930 can include as described above. Figure 9 The relay AP, relay STA, and relay functions are described herein. In one embodiment, STA 910 may be an AP STA, and STA 920 may be a non-AP STA, or vice versa. In another embodiment, both STA 910 and 920 may be AP STAs or non-AP STAs. STA 910 and 920 may communicate directly.

[0139] Due to unreliable communication or to extend the range of existing communication, STA 910 can use relay 930 to communicate with STA 920. Therefore, STA 910 can transmit data frames destined for STA 920 via relay 930. STA 910 and / or relay 930 may optionally employ TXOP protection to protect the transmitted data frames while relaying them via relay 930. In another embodiment, STA 910 and / or relay 930 may optionally not employ TXOP protection to protect the data frames while relaying them via relay 930.

[0140] Figure 10 This is an example 1000 illustrating relaying without Transmission Opportunity (TXOP) protection. Example 1000 may be an example of a TXOP sharing procedure according to section 10.54.5 of the IEEE 1002.11 draft standard “IEEE P802.11-REVme™ / D2.1, January 2023”. Figure 10 As shown, Example 1000 may include STA1010 and 1012 and relay 1011.

[0141] In Example 1000, STA 1010 can be an STA that supports the TXOP sharing program. For example... Figure 10As shown, STA 1010 can transmit data frame 1020 destined for STA 1012 via relay 1011. Data frame 1020 can be a Protocol Version 1 (PV1) QoS data frame. In an implementation, STA 1010 can set the relay frame field in the frame control field of data frame 1020 to 1. A relay frame field set to 1 indicates a shared TXOP for the relay. Upon receiving data frame 1020 with its relay frame field set to 1, if an explicit ACK procedure is used, relay 1011 can transmit an ACK frame 1021. Alternatively, if an implicit ACK procedure is used, relay 1011 may not transmit an ACK frame.

[0142] In Example 1000, relay 1011 can transmit data frame 1022 to STA 1012 without protection. STA 1012 can transmit ACK frame 1023 after receiving data frame 1022 from relay 1011. A relay without TXOP protection allows for lower latency transmission of data frame 1020 from STA 1010 to STA 1012. However, communication may be less reliable if other STAs in the same BSS are likely to be within the communication range of STA 1010, 1012, and relay 1011. To improve communication reliability, RTS / CTS procedures can be used to protect relay data frames, as further described below.

[0143] Figure 11 Example 1100 of a Request to Send (RTS) / Clear to Send (CTS) procedure is shown. Example 1100 may illustrate an RTS / CTS procedure as defined in Section 10.3.2.9 of the IEEE 802.11 draft standard “IEEE P802.11-REVme™ / D2.1, January 2023”. Figure 11 As shown, Example 1100 may include STAs 1102 and 1104. Other STAs in the same BSS may also be within the communication range of STAs 1102 and 1104.

[0144] In the example, STA 1102 can transmit RTS frame 1106 to STA 1104. STA 1102 can transmit RTS frame 1106 to prevent one or more hidden STAs from transmitting data frame 1110 that STA 1102 is attempting to transmit. RTS frame 1106 may contain a duration / ID field. The duration / ID field can be set to the time (in microseconds) required to transmit data frame 1110, plus one CTS frame, plus one ACK frame (if needed), plus three SIFS (Short Interframe Spacing) periods.

[0145] In the example, STA 1104 can respond to RTS frame 1106 by transmitting CTS frame 1108 to STA 1102. CTS frame 1108 can be transmitted one SIFS cycle after RTS frame 1106. STA 1104 can respond to RTS frame 1106 when it is addressed to STA 1106, taking NAV into account, unless NAV is set by a frame originating from STA 1102. STA 1104 can respond to RTS frame 1106 when it is addressed to STA 1106 and if NAV indicates idle. For non-S1G STAs, NAV indicates idle when the NAV count is 0, or when the NAV count is non-zero but the non-bandwidth signaling TA obtained from the TA field of RTS frame 1106 matches the stored TXOP holder address. For S1G STA, NAV indicates idle when both the NAV and RID (Response Indication Delay) counters are 0, or when either the NAV or RID counter is non-zero but the TA field of RTS frame 1106 matches the stored TXOP holder address.

[0146] STA 1104 can set the RA field of CTS frame 1108 to the non-bandwidth signaling TA obtained from the TA field of RTS frame 1106. STA 1104 can set the duration field of CTS frame 1108 based on the duration / ID field of RTS frame 1106, that is, equal to the value of the duration / ID field of RTS frame 1106, adjusted by subtracting the time required to transmit CTS frame 1108 and one SIFS period.

[0147] After receiving CTS frame 1108, STA 1102 may wait for one SIFS cycle before transmitting data frame 1110. STA 1104 may transmit ACK frame 1112 in response to data frame 1110. STA 1104 may transmit ACK frame 1112 after receiving data frame 1110, after a SIFS interval.

[0148] As shown in Example 1100, other STAs within the communication range of STAs 1102 and 1104 and belonging to the same BSS can set their NAV based on RTS frame 1106 and / or CTS frame 1108. For example, the STA receiving RTS frame 1106 can set its NAV based on the duration / ID field of RTS frame 1106. Another STA receiving CTS frame 1108 can set its NAV based on the duration field of CTS frame 1108. Therefore, other STAs may not be able to access the channel using EDCA until the transmission of ACK frame 1112 ends.

[0149] Figure 12Example 1200 illustrates a trunk with TXOP protection. Example 1200 may be an example of a TXOP sharing procedure according to section 12.54.5 of the IEEE 802.11 standard draft "IEEE P802.11-REVme™ / D2.1, January 2023". Figure 12 As shown, Example 1200 may include STAs 1210 and 1212 and a relay 1211.

[0150] In the example, STA 1210 may be an STA that supports the TXOP sharing procedure. STA 1210 may transmit RTS frame 1220 to relay 1211 before transmitting data frame 1222. If its NAV indicates idle, relay 1211 may respond to RTS frame 1220 by transmitting CTS frame 1221 to STA 1210. After receiving CTS frame 1221, STA 1210 may transmit data frame 1222 to relay 1211. If an explicit ACK procedure is used, relay 1211 may transmit ACK frame 1223. Alternatively, if an implicit ACK procedure is used, relay 1211 may not transmit an ACK frame.

[0151] Similarly, before relaying received data frame 1222 to STA 1212, relay 1211 can transmit RTS frame 1224 to STA 1212. If its NAV indicates idle, STA 1212 can respond to RTS frame 1224 by transmitting CTS frame 1225 to relay 1211. After receiving CTS frame 1225, relay 1211 can transmit data frame 1226 (a relay of data frame 1222) to STA 1212. STA 1212 can then transmit ACK frame 1227 to relay 1211 after receiving data frame 1226.

[0152] Relays with TXOP protection provide a more reliable method for transmitting data frames from the source STA to the destination STA. This can be achieved by sequentially using the RTS / CTS procedure in both the source-to-relay link and the relay-to-destination link. However, if the relay-to-destination link is unavailable due to media congestion, a delay may occur until the relay receives the CTS frame from the destination STA and can then transmit the data frame to the destination STA. Therefore, an end-to-end approach providing TXOP protection for both links may be more suitable for preventing any such delays.

[0153] In the next Wi-Fi standard, Triggered TXOP Sharing Procedure (TXS) allows an AP to allocate a portion of the time within its acquired TXOP to a STA to transmit one or more non-trigger-based (non-TB) PPDUs. For Triggered TXOP Sharing Procedure, the AP can transmit a Multi-User Request to Send (MU-RTS) trigger frame, where the Triggered TXOP Sharing Mode subfield is set to a non-zero value. The MU-RTS trigger frame is used to trigger CTS frames from multiple users.

[0154] In the example implementation, the MU-RTS TXS (Trigger TXOP Share) Trigger (MRTT) frame is an MU-RTS trigger frame in which the Trigger TXOP Share mode subfield is set to a non-zero value (e.g., 1 or 2).

[0155] In the example, during a portion of the allocated time, the STA can transmit one or more non-TB PPDUs to the AP. In this case, the Trigger TXOP Shared Mode subfield in the MU-RTS TXS trigger frame can be set to 1.

[0156] In the example, during a portion of the allocated time, the STA can transmit one or more non-TB PPDUs to the AP or a peer STA. In the example, the peer STA can be a STA with a connection for peer-to-peer (P2P) communication or direct communication with the STA. In this case, the trigger TXOP sharing mode subfield in the MU-RTS TXS trigger frame can be set to 2. In the example, a direct radio link is established according to the Channel Direct Link Establishment (TDLS) protocol.

[0157] A probe PPDU is a PPDU transmitted by the transmitting STA so that the receiving STA can estimate the channel between the transmitting and receiving STAs. According to the IEEE 802.11 standard, a probe PPDU is a PPDU with a value of SOUNDING for the SOUNDING parameter of the corresponding RXVECTOR or TXVECTOR.

[0158] In the example, probing PPDUs includes probing empty data PPDUs (NDPs). An NDP is a PPDU that does not carry a data field.

[0159] In the example, the probe PPDU may include a PPDU carrying training symbols for channel sensing. The training symbols may be known at both the transmitting STA and the receiving STA. The receiving STA can use the training symbols from the channel sensing to estimate channel state information (CSI). The CSI may include channel coefficients.

[0160] Channel sensing can employ transmit beamforming with explicit feedback mechanisms, such as explicit feedback beamforming, to allow the transmitting STA to transmit the probe PPDU to the receiving STA.

[0161] Transmit beamforming is a technique in which a transmitting STA uses knowledge of the MIMO channel to generate a steering matrix, which is applied to the transmitted signal to optimize reception at one or more receiving STAs. The STA that transmits using the steering matrix is ​​called a beamformer (a transmitter of beamformed signals). The STA that optimizes reception for it is called a beam receiver (a receiver of beamformed signals). Transmit beamforming can be used to probe SU MIMO or MU MIMO channels.

[0162] In explicit feedback beamforming, the beamformer applies an orthogonal spatial mapping matrix as a steering matrix to the training symbols in the probed PPDU. By receiving the probed PPDU via a MIMO channel, the beamformer uses the training symbols to measure the effective channel. The effective channel is the product of the equivalent complex baseband MIMO channel coefficient matrix and the steering matrix used for transmission. Using the estimate of the equivalent channel, the beamformer can prepare a Channel Quality Indication (CQI) as CSI feedback, or prepare a beamforming feedback matrix as beamforming feedback. The beamformer quantizes the feedback and sends it to the beamformer. The beamformer can use this feedback to calculate a new steering matrix for beamforming data transmission.

[0163] The Extremely High Throughput (EHT) probe protocol can use explicit feedback beamforming.

[0164] EHT STAs can use the EHT probe protocol to determine the Channel Indicator (CSI). The EHT probe protocol provides an explicit feedback mechanism, including EHT non-trigger-based (non-TB) probe sequences and EHT trigger-based (TB) probe sequences. The EHT beam receiver can use a training signal (e.g., EHT probe NDP) transmitted by the EHT beamformer to measure the channel and transmit a transformed estimate of the CSI. The transformed estimate of the CSI includes a quantized CQI feedback or a quantized beamforming feedback matrix based on an estimate of the equivalent channel. The EHT beamformer can use this estimate to derive the steering matrix.

[0165] EHT beamforming receivers can return an estimate of the CSI from an EHT compressed beamforming / CQI report carried in one or more EHT compressed beamforming / CQI frames. There are three types of EHT compressed beamforming / CQI reports: a) SU Feedback: The EHT Compressed Beamforming / CQI report includes the EHT Compressed Beamforming report field.

[0166] b) MU Feedback: The EHT Compressed Beamforming / CQI report includes EHT Compressed Beamforming report fields and EHT MU-specific beamforming report fields.

[0167] c) CQI Feedback: The EHT Compressed Beamforming / CQI report includes EHT CQI report fields.

[0168] If the length of the resulting frame is less than or equal to 11,454 octets, the EHT compressed beamforming / CQI report can be carried in a single EHT compressed beamforming / CQI frame. Otherwise, the EHT beamforming feedback can be segmented, and each segment can be carried in an EHT compressed beamforming / CQI frame.

[0169] The EHT beamformer should support the maximum MPDU length for EHT compressed beamforming / CQI reporting, which is the minimum of the following: 11,454 octets, and the maximum length of EHT compressed beamforming / CQI reporting that the EHT beamformer intends to request from one or more of its EHT beam receivers.

[0170] Figure 13 The example 1300 Empty Data PPDU (NDP) Notification (NDPA) frame format is shown.

[0171] The NDP announcement frame has four variants: VHT NDP announcement frame, HE NDP announcement frame, ranging NDP announcement frame, and EHT NDP announcement frame. These four formats are distinguished by the settings of the NDP announcement variant subfield in the probe dialogue token field.

[0172] Each STA in the NDP announcement frame contains at most one STA information field.

[0173] The NDP announcement frame contains at least one STA information field with AID11, AID12, or AID13 subfields.

[0174] If an NDP advertisement frame contains only one STA information field with a value less than 2008 in the AID11, AID12, or AID13 subfield, then in the case of a VHT, HE, or EHT NDP advertisement frame, the RA field is set to the address of the STA addressed in the single STA information field of this NDP advertisement frame. In the case of a ranging NDP advertisement frame, the RA address is set to the address of the RDA or ISTA that is the intended receiver of the frame. If an NDP advertisement frame contains more than one STA information field with a value less than 2008 in the AID11 subfield, then the RA field is set to the broadcast address.

[0175] The TA field is set to the address of the STA transmitting the NDP advertisement frame, or the bandwidth signaling TA of the STA transmitting the NDP advertisement frame.

[0176] The NDP Announcement Variant subfield, set in the Probe Dialogue Token field, identifies a variant of the NDP Announcement frame.

[0177] The Probe Dialogue Token Number subfield in the Probe Dialogue Token field contains a value selected by the beamformer to identify the VHT NDP announcement frame.

[0178] The STA information list field contains one or more (n) STA information fields.

[0179] In the HE NDP announcement frame, the Duration, RA, and TA fields are set as in the VHT NDP announcement frame. The NDP announcement variant field is set to 2 to identify the frame as an HE NDP announcement frame. The Probe Dialogue Token Number field in the Probe Dialogue Token field contains a value selected by the beamformer to identify the HE NDP announcement frame.

[0180] In the EHT NDP announcement frame, the Duration, RA, and TA fields are set to the same values ​​as in the VHT NDP announcement frame. The NDP announcement variant field is set to 3 to identify the frame as an EHT NDP announcement frame. The Probe Dialogue Token Number field in the Probe Dialogue Token field contains a value selected by the beamformer to identify the EHT NDP announcement frame.

[0181] The AID11 subfield contains the identifier of the STA that is expected to process the following EHT probe NDP and is ready to probe feedback.

[0182] Some BW information subfields include a resolution subfield and a feedback bitmap subfield.

[0183] The resolution subfield in the partial BW information subfield indicates the resolution bandwidth of each bit in the feedback bitmap subfield.

[0184] The Feedback Bitmap subfield indicates whether feedback is requested for each resolution bandwidth, and is ordered from lowest to highest frequency, then padded with zeros. Bits in the Feedback Bitmap subfield set to 1 indicate a feedback request for the corresponding frequency with the resolution bandwidth; and therefore, B1 set to 1 indicates a feedback request for the lowest frequency at the indicated resolution bandwidth.

[0185] When the bandwidth of the PPDU carrying the EHT NDP advertisement frame is less than 320 MHz, the resolution bit B0 is set to 0 to indicate a resolution of 20 MHz.

[0186] —When the bandwidth of the PPDU carrying the EHT NDP advertisement frame is equal to 20 MHz, B1 is set to 1 to indicate a feedback request to the 242 FM RU. B2 through B8 are set to 0.

[0187] —When the bandwidth of the PPDU carrying the EHT NDP announcement frame is equal to 40 MHz, B1 and B2 indicate feedback requests for each of the two 242-frequency modulation RUs from the lower frequency to the higher frequency. B3 through B8 are set to 0.

[0188] —When the bandwidth of the PPDU carrying the EHT NDP announcement frame is equal to 80 MHz, if B1 to B4 are all set to 1, it indicates a feedback request for 996 frequency modulation RUs; otherwise, B1 to B4 indicate a feedback request for each of the four 242 frequency modulation RUs from the lower frequency to the higher frequency. B5 to B8 are set to 0.

[0189] —When the bandwidth of the PPDU carrying the EHT NDP advertisement frame is equal to 160 MHz, if all B1 to B4 are set to 1, they indicate a feedback request for the lower 996 frequency modulation RUs; otherwise, B1 to B4 indicate a feedback request for each of the four 242 frequency modulation RUs in the lower 80 MHz from the lower frequency to the higher frequency. If all B5 to B8 are set to 1, they indicate a feedback request for the upper 996 frequency modulation RUs; otherwise, B5 to B8 indicate a feedback request for each of the four 242 frequency modulation RUs in the upper 80 MHz from the lower frequency to the higher frequency.

[0190] When the bandwidth of the PPDU carrying the EHT NDP advertisement frame is equal to 320 MHz, the resolution subfield (B0) is set to 1 to indicate a resolution of 40 MHz. If both B1 and B2 are set to 1, it indicates a feedback request for the lowest 996 FM RUs; otherwise, B1 and B2 indicate a feedback request for each of the two 484 FM RUs in the lowest 80 MHz range from lower to higher frequencies. If both B3 and B4 are set to 1, it indicates a feedback request for the second lowest 996 FM RUs; otherwise, B3 and B4 indicate a feedback request for each of the two 484 FM RUs in the second lowest 80 MHz range from lower to higher frequencies. If both B5 and B6 are set to 1, it indicates a feedback request for the third lowest 996 FM RUs; otherwise, B5 and B6 indicate a feedback request for each of the two 484 FM RUs in the third lowest 80 MHz range from lower to higher frequencies. If both B7 and B8 are set to 1, they indicate a feedback request for up to 996 frequency modulation RUs; otherwise, B7 and B8 indicate a feedback request for each of two 484 frequency modulation RUs ranging from lower to higher frequencies within a maximum of 80 MHz. The feedback frequency set for each 484 frequency modulation RU consists of the feedback frequency sets of two 242 frequency modulation RUs overlapping with the 484 frequency modulation RUs.

[0191] The feedback type of EHT TB probes is the same as that of Ng and codebook-size subfields, and the feedback type of HE TB probes is the same as that of Ng and codebook-size subfields. The feedback type of EHT non-TB probes is the same as that of Ng and codebook-size subfields, and the feedback type of HE non-TB probes is the same as that of Ng and codebook-size subfields.

[0192] In EHT NDP advertisement frames that have more than one STA information field containing a value less than 2008 in the AID11 subfield, RA is the broadcast address, and the following applies: —If the feedback type, Ng subfield, and codebook size subfield indicate SU or MU, then the Nc index subfield indicates the number of columns in the compressed beamforming feedback matrix minus 1, i.e., Nc-1. Nc index subfield values ​​higher than 7 are retained.

[0193] —If the feedback type, Ng subfield, and codebook size subfield indicate CQI, then the Nc index subfield indicates the number of spatial flows in the CQI report minus 1, i.e., Nc-1. Nc index subfield values ​​higher than 7 are retained.

[0194] In an EHT NDP advertisement frame with a single STA information field containing a value less than 2008 in the AID11 subfield, RA is a single address and the Nc index subfield is reserved.

[0195] Figure 14An example EHT compressed beamforming / CQI frame 1400 is shown. EHT compressed beamforming / CQI frame 1400 can be an unacknowledged action frame for category EHT. The action field of the EHT compressed beamforming / CQI frame contains information including a category field, an EHT action field, an EHT MIMO control field, an EHT compressed beamforming report field, an EHT MU-specific beamforming report field, and an EHT TQI report.

[0196] For the EHT category, the category field is set to the value 36.

[0197] The EHT Action field, located in an octet immediately following the Category field, distinguishes the EHT Action frame format. The EHT Action field value is associated with each frame format within the EHT category. For EHT Compressed Beamforming / CQI, the EHT Action field is set to a value of 0.

[0198] The EHT MIMO control fields include the Nc index subfield, Nr index subfield, BW subfield, grouping subfield, codebook information subfield, feedback type subfield, remaining feedback segment subfield, first feedback segment subfield, partial BW information subfield, and probe dialogue token number subfield.

[0199] In all or part of the EHT Compressed Beamforming / CQI frames that do not carry an EHT Compressed Beamforming / CQI report, the Nc index, Nr index, BW, group, codebook information, feedback type, and probe dialogue token number subfields are retained, the first feedback segment subfield is set to 0, and the remaining feedback segment subfields are set to 7.

[0200] The EHT compressed beamforming report field carries the average SNR for each spatial stream and the compressed beamforming feedback matrix, which is used by the transmission beamformer to determine the steering matrix for explicit feedback beamforming.

[0201] The EHT MU-specific beamforming report field carries explicit feedback in the form of ΔSNR. The transmission MU beamformer can use the information in the EHT compressed beamforming report field and the EHT MU-specific beamforming report field to determine the steering matrix for DLMU-MIMO.

[0202] The EHT CQI report field carries the per-RU average SNR for each spatial stream, where each per-RU average SNR is the arithmetic mean (in decibels) of the SNR on the subcarriers of the 26-frequency modulated RUs that are requesting feedback.

[0203] The EHT CQI report field contains EHT CQI report information. If the feedback type subfield in the EHT MIMO control field indicates CQI feedback, then the EHT CQI report information is included in the EHT compressed beamforming / CQI report.

[0204] The existence and content of the EHT Compressed Beamforming Report field, the EHT MU Dedicated Beamforming Report field, and the EHT CQI Report field depend on the value of the Feedback Type subfield of the EHT MIMO Control field.

[0205] There are no vendor-specific elements in the EHT compressed beamforming / CQI frame.

[0206] EHT non-TB probe sequences can be initiated by an EHT beamformer using the following: a separately addressed EDT NDP advertisement frame including exactly one STA information field, followed by an ELT probe NDP after the SIFS. An EHT beam receiver can respond using an EHT compressed beamforming / CQI frame after the SIFS.

[0207] Figure 15 Example 1500 EHT non-trigger-based (non-TB) probe sequence is shown. Figure 15 As shown, Example 1500 includes AP 1502 and STA 1504. Example 1600 allows AP 1502 to initiate an EHT non-TB probe sequence by transmitting an NDPA frame 1510 (e.g., an EHT NDP advertisement frame). AP 1502 can initiate an EHT non-TB probe sequence to request SU feedback or CQI feedback from STA 1604.

[0208] In the example, the SU feedback may include a compressed beamforming report. In the example, the compressed beamforming report may include the average SNR for each spatial flow and a compressed beamforming feedback matrix, which the transmission beamformer uses to determine the steering matrix for explicit feedback beamforming.

[0209] In the example, CQI feedback may include a CQI report. In the example, the CQI report may include the average SNR per RU for each spatial stream. In the implementation, each average SNR per RU may include the arithmetic mean (in decibels) of the SNRs on the subcarriers of the 26 frequency-modulated RUs requesting feedback.

[0210] AP 1502 may be an EHT beamformer. NDPA frame 1510 may contain a single STA information field. The AID11 subfield of the STA information field may be set to the AID of the STA identified by the RA field (e.g., STA 1504), or may be set to 0 if the STA identified by the RA field is an associated AP, mesh STA, or IBSS STA. NDPA frame 1510 may be followed by NDPA frame 1512 (e.g., EHT probe NDP) after SIFS, which may be followed by feedback frame 1514 carried in a PPDU containing one or more EHT compressed beamforming / CQI frames.

[0211] Figure 16 Example 1600 of the EHT-based triggered (TB) probe sequence is shown. Figure 16 As shown, Example 1600 includes AP 1602 and STAs 1604 and 1606. Example 1600 can initiate an ELT TB probe sequence start by AP 1602 transmitting NDPA frame 1610. AP 1602 can initiate an ELT TB probe sequence to request SU feedback, MU feedback, or CQI feedback from STAs 1604 and 1606.

[0212] In the example, the SU feedback may include a compressed beamforming report. In the example, the compressed beamforming report may include the average SNR for each spatial flow and a compressed beamforming feedback matrix, which the transmission beamformer uses to determine the steering matrix for explicit feedback beamforming.

[0213] In the example, MU feedback may include compressed beamforming reports and MU-specific beamforming reports. In the example, the MU-specific beamforming report may include explicit feedback in the form of ΔSNR.

[0214] In the example, CQI feedback may include a CQI report. In the example, the CQI report may include the average SNR per RU for each spatial stream. In the implementation, each average SNR per RU may include the arithmetic mean (in decibels) of the SNRs on the subcarriers of the 26 frequency-modulated RUs requesting feedback.

[0215] AP 1602 can be an EHT beamformer. NDPA frame 1610 may include two or more STA information fields and an RA field set to a broadcast address. After NDPA frame 1610 and a SIFS interval, AP 1602 may transmit NDP frame 1612, followed by a trigger (e.g., Beamforming Report Polling (BFRP) trigger) frame 1614 after an SIFS interval. Trigger frame 1614 can address STAs 1604 and 1606 as EHT beam receivers. In response, STAs 1604 and 1606 may respond after trigger frame 1614 and an SIFS interval using corresponding feedback frames 1616 and 1618. Feedback frames 1616 and 1618 may each be carried in an EHT TBPPDU and may include one or more EHT compressed beamforming / CQI frames.

[0216] AP 1602 may send one or more additional trigger frames in the same TXOP to request feedback frames from EHT beam receivers that are not addressed in trigger frame 1614. AP 1602 may not transmit trigger frames for STAs identified in NDPA frame 1610 unless the trigger frame is in the same TXOP as NDPA frame 1610.

[0217] Figure 17 Example 1700 of a probe procedure for relay communication is shown. Example 1700 may be an example of an EHT non-TB probe sequence. Figure 17 As shown, Example 1700 may include STAs 1702, 1704, and 1706. In this example, STAs 1702 and 1704 may be within each other's communication range, STAs 1702 and 1706 may be outside each other's communication range, and STAs 1704 and 1706 may be within each other's communication range. In this example, STA 1702 may include an AP. In this example, STA 1704 may include a trunk. In this example, a trunk may include a trunk AP and a trunk STA. In this example, STA 1704 may include a mobile trunk. In this example, STA 1706 may include a non-AP STA.

[0218] In the examples, STA 1702 can be used as an EHT beamformer to support EHT non-TB detection. In the examples, STA 1704 can be used as both a beamformer and a beam receiver to support EHT non-TB detection. In the examples, STA 1706 can be used as a beam receiver to support non-TB detection.

[0219] like Figure 17As shown, Example 1700 may include a first detection phase 1708-1 and a second detection phase 1708-2. The first detection phase 1708-1 may include a first detection sequence for estimating a first channel from STA 1702 to STA 1704. The second detection phase 1708-2 may include a second detection sequence for estimating a second channel from STA 1704 to STA 1706. In this example, the first or second detection sequence may include an EHT non-TB detection sequence. In this example, the second detection phase 1708-2 may include feedback from STA 1704 to STA 1702 reporting the second detection sequence.

[0220] like Figure 17 As shown, the first probing phase 1708-1 can begin with STA 1702 transmitting NDPA frame 1710 to STA 1704. In this example, NDPA frame 1710 may include an EHT NDPA frame. NDPA frame 1710 may advertise an NDP 1712 to be transmitted by STA 1702 for STA 1704 to estimate the first channel. In this example, NDP 1712 may include an EHT probe NDP. In this example, NDPA frame 1710 may request SU feedback or CQI feedback from STA 1704. After transmitting NDPA frame 1710 for a SIFS interval, STA 1702 transmits NDP 1712 to STA 1704. After receiving NDP 1712 for a SIFS interval, STA 1704 transmits a feedback frame 1714 to STA 1702 based on NDP 1712. In the example, feedback frame 1714 may include an EHT compressed beamforming / CQI frame, which contains SU feedback or CQI feedback for the first channel.

[0221] like Figure 17As shown, the second probing phase 1708-2 can be initiated by STA 1702 transmitting a trigger frame 1724 to STA 1704, which triggers STA 1704 to initiate a second probing sequence for estimating the second channel. In the example, after receiving the trigger frame 1724, STA 1704 can transmit an NDPA frame 1716 to STA 1706. In the example, NDPA frame 1716 may include an EHT NDPA frame. NDPA frame 1716 may announce an NDP 1718 to be transmitted by STA 1704 for STA 1706 to estimate the second channel. In the example, NDP 1718 may include an EHT probe NDP. In the example, NDPA frame 1716 may request SU feedback or CQI feedback from STA 1706. After transmitting NDPA frame 1716 for an interval of SIFS, STA 1704 transmits NDP 1718 to STA 1706. After receiving NDP 1718, at a SIFS interval, STA 1706 transmits feedback frame 1720 based on NDP 1718. In an example, feedback frame 1720 may include an EHT compressed beamforming / CQI frame containing SU feedback or CQI feedback for a second channel. Figure 17 As shown, after receiving feedback frame 1720, STA 1704 may transmit feedback frame 1722 reporting feedback from the second channel. In this example, feedback frame 1722 may include the EHT compressed beamforming / CQI frame received in feedback frame 1720. In this example, feedback frame 1722 may include SU feedback or CQI feedback from the second channel.

[0222] Typically, the relay probing procedure is repeated whenever the first channel and / or the second channel changes. For example, as described above, the STA 1704 may include a mobile relay that causes both the first and second channels to change upon movement. Upon detecting a change, the relay probing procedure can be repeated to re-estimate the first and second channels. Figure 17 In cases where the relay detection procedure requires two separate detection sequences to estimate the first and second channels, the overhead for performing relay detection can become excessive, especially when the first and second channels change frequently. For example, each time the first and / or second channel changes, Figure 17 The detection procedure requires the transmission of at least two NDPA frames, at least three feedback frames, and one trigger frame. This lengthy relay procedure can also increase the latency of data transmission between STA 1702 and STA 1706.

[0223] As further described below, embodiments of this disclosure address the aforementioned problems of existing detection procedures used for relaying.

[0224] In one aspect, a first STA may receive a first frame from a second STA, the first frame indicating or announcing a first Physical Layer Protocol Data Unit (PPDU) to be transmitted by the second STA; and instructing or triggering the first STA to transmit a second frame to a third STA, the second frame indicating or announcing a second PPDU to be transmitted by the first STA to the third STA. The first STA may be a relay STA, the second STA may be a source STA, and the third STA may be a destination STA. The first PPDU can be used by the first STA to estimate a first channel from the second STA to the first STA. The second PPDU can be used by the third STA to estimate a second channel from the first STA to the third STA. Therefore, the first frame can simultaneously trigger the estimation of both the first and second channels.

[0225] In another aspect, the first STA may receive a first PPDU for estimating a first channel from the second STA to the first STA. The first STA may transmit a second PPDU for estimating a second channel from the first STA to the third STA. The first STA may receive a first frame from the third STA including a first estimate of the second channel, and may transmit a second frame to the second STA, the second frame including: a second estimate of the first channel; and a first estimate of the second channel. Therefore, the first STA can transmit the estimates of the first channel and the second channel to the second STA in a single overhead.

[0226] Figure 18 This is an example illustrating a probe procedure for relay communication according to an embodiment. Example 1800 is provided for illustrative purposes only and is not limiting.

[0227] like Figure 18 As shown, Example 1800 may include STAs 1802, 1804, and 1806. In this example, STAs 1804 and 1806 may be associated with STA 1802. STAs 1802, 1804, and / or 1806 may each include a multilink device (MLD).

[0228] In this example, STA 1802 and STA 1804 are within each other's communication range, STA 1802 and STA 1806 are outside each other's communication range, and STA 1804 and STA 1806 are within each other's communication range. In this example, STA 1802 may include an AP. In this example, STA 1802 may include a trunk. In this example, a trunk may include a trunk AP and a trunk STA. In this example, STA 1804 may include a mobile trunk. In this example, STA 1806 may include a non-AP STA.

[0229] In Example 1800, it is assumed that STA 1802 supports relay detection capability. In this example, supporting relay detection capability allows STA 1802 to transmit a first frame (such as frame 1810 described below), which: indicates or announces a first PPDU (such as PPDU 1812 described below) to be transmitted by STA 1802; and indicates or triggers a second STA (such as STA 1804) to transmit a second frame (such as frame 1816 described below) to a third STA (such as STA 1806), which indicates or announces a second PPDU (such as PPDU 1818 described below) to be transmitted by the second STA to the third STA. In an embodiment, STA 1802 may include a beamformer. In this example, supporting relay detection capability allows STA 1802 to transmit a first PPDU for estimating a first channel from STA 1802 to the second STA after transmitting the first frame. In this example, supporting relay detection capability allows STA 1802 to receive frames from the second STA (such as frames 1814 and 1822 described below).

[0230] In Example 1800, it is assumed that STA 1804 supports relay detection capability. In this example, supporting relay detection capability allows STA 1804 to receive a first frame (such as frame 1810 described below), which: indicates or announces a first PPDU (such as PPDU 1812 described below) to be transmitted by a second STA (such as STA 1802); and indicates or triggers STA 1804 to transmit a second frame (such as frame 1816 described below) to a third STA (such as STA 1806), which indicates or announces a second PPDU (such as PPDU 1818 described below) to be transmitted by STA 1804 to the third STA. In an embodiment, STA 1804 may include a beam receiver. In this example, supporting relay detection capability allows STA 1804 to transmit frames / PPDUs (such as frame 1816 and PPDU 1818 described below) to the second STA. In an embodiment, STA 1804 may include a beamformer. In the example, the support for relay detection allows STA 1804 to transmit frames / PPDUs (such as frame 1816 and PPDU 1818 described below) to a third STA. In the example, the support for relay detection allows STA 1804 to receive a first PPDU for estimating a first channel from the second STA to STA 1804 after receiving the first frame. In the example, the support for relay detection allows STA 1804 to transmit a second PPDU for estimating a second channel from STA 1804 to the third STA after transmitting the second frame.

[0231] In this embodiment, before Example 1800 begins, STAs 1802 and 1804 may exchange the first and second frames ( Figure 18 (Not shown) to exchange capability information. In an embodiment, the first frame may include capability information of STA 1802, which includes a first indication that STA 1802 supports relay detection capability. In an embodiment, the second frame may include capability information of STA 1804, which includes a second indication that STA 1804 supports relay detection capability. In an embodiment, the first and second frames may be exchanged after association between STA 1802 and 1804. In an embodiment, the first and second frames may include management frames.

[0232] like Figure 18 As shown, Example 1800 allows STA 1802 to transmit frame 1810 to STA 1804 to initiate a probe sequence. In this example, the probe sequence may include estimating a first channel from STA 1802 to STA 1804 and a second channel from STA 1804 to STA 1806. In this example, the probe sequence may include probes for relay communication. In this example, the probe sequence may include reporting feedback on the first / second channel to STA 1802.

[0233] In one embodiment, frame 1810 may indicate or announce PPDU 1812 to be transmitted from STA 1802 to STA 1804. In another embodiment, frame 1810 may further indicate or trigger STA 1804 to transmit frame 1816 to STA 1806. In yet another embodiment, frame 1816 may indicate or announce PPDU 1818 to be transmitted from STA 1804 to STA 1806. In another embodiment, PPDU 1812 or 1818 may include a probe PPDU. In an example, PPDU 1812 or 1818 may include an NDP.

[0234] In one embodiment, frame 1810 may request frame 1814 and / or frame 1822 from STA 1804. In another embodiment, frame 1816 may request frame 1820 from STA 1806. In one example, frame 1810 may indicate a first feedback type for use by frame 1814 and / or a second feedback type for use by frames 1820 and / or 1822. In one example, the first or second feedback type may indicate SU feedback, MU feedback, or CQI feedback. In one example, the second feedback type may be the same as the first feedback type. In another example, the second feedback type may be different from the first feedback type.

[0235] In embodiments, SU feedback may include a compressed beamforming report. In an example, the compressed beamforming report may include an average SNR for each spatial stream and a compressed beamforming feedback matrix, which is used by the transmission beamformer to determine the steering matrix for explicit feedback beamforming. In embodiments, MU feedback includes a compressed beamforming report and a MU-specific beamforming report. In an example, the MU-specific beamforming report may include explicit feedback in the form of ΔSNR. In embodiments, CQI feedback may include a CQI report. In an example, the CQI report may include the average SNR per RU for each spatial stream. In an implementation, each average SNR per RU may include the arithmetic mean (in decibels) of the SNR on the subcarriers of the 26-frequency modulated RUs requesting feedback.

[0236] In an embodiment, frame 1810 may include a control frame. In an example, the control frame may include a notification frame. In an example, the notification frame may include an NDP Notification (NDPA) frame. In an example, the NDPA frame may include an Ultra-High Reliability (UHR) NDPA frame.

[0237] Following transmission frame 1810, STA 1802 may transmit PPDU 1812 to STA 1804. In an embodiment, STA 1802 may transmit PPDU 1812 to STA 1804 after transmission frame 1810, with a SIFS interval. In an embodiment, PPDU 1812 may be used by STA 1804 to estimate the first channel from STA 1802 to STA 1804.

[0238] Upon receiving PPDU 1812, STA 1804 may transmit frame 1814 to STA 1802. In an embodiment, frame 1814 may indicate a first estimate of the first channel. In an embodiment, the first estimate may include first feedback based on PPDU 1812. In an example, the first feedback may include SU feedback or CQI feedback based on the first feedback type indicated in frame 1810. In an embodiment, frame 1814 may include a management frame. In an example, the management frame may include an action frame. In an example, frame 1814 may include a compressed beamforming report or a CQI report.

[0239] After transmitting frame 1814 to STA 1802, STA 1804 may transmit frame 1816 to STA 1806. In one embodiment, STA 1804 may transmit frame 1816 to STA 1806 after transmitting frame 1814, with a SIFS interval. In another embodiment, STA 1804 may transmit frame 1816 before transmitting frame 1814. In an example, frame 1816 may request frame 1820 from STA 1806. In an example, frame 1816 may indicate a second feedback type for use by frame 1820 based on an indication in frame 1810. In one embodiment, frame 1816 may include a control frame. In an example, the control frame may include an announcement frame. In an example, the announcement frame may include an NDP announcement (NDPA) frame. In an example, the NDPA frame may include an Ultra-High Reliability (UHR) NDPA frame.

[0240] Following transmission frame 1816, STA 1804 may transmit PPDU 1818 to STA 1806. In an embodiment, STA 1804 may transmit PPDU 1818 after transmission frame 1816 at a SIFS interval. In an embodiment, PPDU 1818 may be used by STA 1806 to estimate a second channel from STA 1804 to STA 1806.

[0241] After receiving PPDU 1818, STA 1806 may transmit frame 1820 to STA 1804. In an embodiment, STA 1806 may transmit frame 1820 after receiving PPDU 1818, with an interval of SIFS. In an embodiment, frame 1820 may indicate a second estimate of the second channel. In an example, the second estimate may include a second feedback based on PPDU 1818. In an example, the second feedback may include SU feedback or CQI feedback based on the second feedback type indicated in frame 1816.

[0242] After receiving frame 1820, STA 1804 may transmit frame 1822 to STA 1802. Frame 1822 may respond to frame 1810. In an embodiment, frame 1822 may include a second estimate of the second channel indicated in frame 1820. In an embodiment, frame 1822 may be used to report a second feedback to STA 1802.

[0243] In an embodiment, frames 1820 and / or 1822 may include management frames. In an example, a management frame may include an action frame. In an example, an action frame may include a compressed beamforming report or a CQI report.

[0244] like Figure 18As shown, according to an embodiment, a single probe sequence can be used to probe the end-to-end relay link between STAs 1802 and 1806. This can significantly reduce the overhead required for probes and the latency of relay data, especially when the first and / or second channels change frequently.

[0245] Figure 19 This is an example illustrating a probe procedure for relay communication according to an embodiment. Example 1900 is provided for illustrative purposes only and is not limiting.

[0246] like Figure 19 As shown, Example 1900 may include STAs 1902, 1904, and 1906. In this example, STAs 1904 and 1906 may be associated with STA 1902. STAs 1902, 1904, and / or 1906 may each include a multilink device (MLD).

[0247] In this example, STA 1902 and STA 1904 are within each other's communication range, STA 1902 and STA 1906 are outside each other's communication range, and STA 1904 and STA 1906 are within each other's communication range. In this example, STA 1902 may include an AP. In this example, STA 1902 may include a trunk. In this example, a trunk may include a trunk AP and a trunk STA. In this example, STA 1904 may include a mobile trunk. In this example, STA 1906 may include a non-AP STA.

[0248] In Example 1900, it is assumed that STA 1902 supports relay detection capability. In this example, supporting relay detection capability allows STA 1902 to transmit a first frame (such as frame 1910 described below), which: indicates or announces a first PPDU (such as PPDU 1912 described below) to be transmitted by STA 1902; and indicates or triggers a second STA (such as STA 1904) to transmit a second frame (such as frame 1914 described below) to a third STA (such as STA 1906), which indicates or announces a second PPDU (such as PPDU 1916 described below) to be transmitted by the second STA to the third STA. In an embodiment, STA 1902 may include a beamformer. In this example, supporting relay detection capability allows STA 1902 to transmit a first PPDU for estimating a first channel from STA 1902 to the second STA after transmitting the first frame. In this example, supporting relay detection capability allows STA 1902 to receive frames from the second STA (such as frames 1920 and 1922 described below).

[0249] In Example 1900, it is assumed that STA 1904 supports relay detection capability. In this example, supporting relay detection capability allows STA 1904 to receive a first frame (such as frame 1910 described below), which: indicates or announces a first PPDU (such as PPDU 1912 described below) to be transmitted by a second STA (such as STA 1902); and indicates or triggers STA 1904 to transmit a second frame (such as frame 1914 described below) to a third STA (such as STA 1906), which indicates or announces a second PPDU (such as PPDU 1916 described below) to be transmitted by STA 1904 to the third STA. In an embodiment, STA 1904 may include a beam receiver. In this example, supporting relay detection capability allows STA 1904 to transmit frames (such as frames 1920 and 1922 described below) to the second STA. In an embodiment, STA 1904 may include a beamformer. In the example, the support for relay detection allows STA 1904 to transmit frames / PPDUs (such as frame 1914 and PPDU 1916 described below) to a third STA. In the example, the support for relay detection allows STA 1904 to receive a first PPDU for estimating a first channel from the second STA to STA 1904 after receiving the first frame. In the example, the support for relay detection allows STA 1904 to transmit a second PPDU for estimating a second channel from STA 1904 to the third STA after transmitting the second frame.

[0250] In this embodiment, before Example 1900 begins, STA 1902 and 1904 may exchange the first and second frames ( Figure 19 (Not shown) to exchange capability information. In an embodiment, the first frame may include capability information of STA 1902, which includes a first indication that STA 1902 supports relay detection capability. In an embodiment, the second frame may include capability information of STA 1904, which includes a second indication that STA 1904 supports relay detection capability. In an embodiment, the first and second frames may be exchanged after association between STA 1902 and 1904. In an embodiment, the first and second frames may include management frames.

[0251] like Figure 19 As shown, Example 1900 allows STA 1902 to transmit frame 1910 to STA 1904 to initiate a probe sequence. In this example, the probe sequence may include estimating a first channel from STA 1902 to STA 1904 and a second channel from STA 1904 to STA 1906. In this example, the probe sequence may include probes for relay communication. In this example, the probe sequence may include reporting feedback on the first / second channel to STA 1902.

[0252] In one embodiment, frame 1910 may indicate or announce PPDU 1912 to be transmitted from STA 1902 to STA 1904. In another embodiment, frame 1910 may further indicate or trigger STA 1904 to transmit frame 1914 to STA 1906. In yet another embodiment, frame 1914 may indicate or announce PPDU 1916 to be transmitted from STA 1904 to STA 1906. In another embodiment, PPDU 1912 or 1916 may include a probe PPDU. In an example, PPDU 1912 or 1916 may include an NDP.

[0253] In one embodiment, frame 1910 may request frame 1920 and / or frame 1922 from STA 1904. In another embodiment, frame 1914 may request frame 1918 from STA 1906. In one example, frame 1910 may indicate a first feedback type for use by frame 1914 and / or a second feedback type for use by frames 1920 and / or 1922. In one example, the first or second feedback type may indicate SU feedback, MU feedback, or CQI feedback. In one example, the second feedback type may be the same as the first feedback type. In another example, the second feedback type may be different from the first feedback type.

[0254] In embodiments, SU feedback may include a compressed beamforming report. In an example, the compressed beamforming report may include an average SNR for each spatial stream and a compressed beamforming feedback matrix, which is used by the transmission beamformer to determine the steering matrix for explicit feedback beamforming. In embodiments, MU feedback includes a compressed beamforming report and a MU-specific beamforming report. In an example, the MU-specific beamforming report may include explicit feedback in the form of ΔSNR. In embodiments, CQI feedback may include a CQI report. In an example, the CQI report may include the average SNR per RU for each spatial stream. In an implementation, each average SNR per RU may include the arithmetic mean (in decibels) of the SNR on the subcarriers of the 26-frequency modulated RUs requesting feedback.

[0255] In an embodiment, frame 1910 may include a control frame. In an example, the control frame may include a notification frame. In an example, the notification frame may include an NDP Notification (NDPA) frame. In an example, the NDPA frame may include an Ultra-High Reliability (UHR) NDPA frame.

[0256] After transmission frame 1910, STA 1902 may transmit PPDU 1912 to STA 1904. In an embodiment, STA 1902 may transmit PPDU 1912 to STA 1904 after transmission frame 1910 with a SIFS interval. In an embodiment, PPDU 1912 may be used by STA 1904 to estimate the first channel from STA 1902 to STA 1904.

[0257] After receiving PPDU 1912 from STA 1902, STA 1904 may transmit frame 1914 to STA 1906. In an embodiment, STA 1904 may transmit frame 1914 to STA 1906 after receiving PPDU 1912, with an interval of SIFS. In an example, frame 1914 may request frame 1918 from STA 1906. In an example, frame 1914 may indicate a second feedback type for use by frame 1918 based on the indication in frame 1910. In an embodiment, frame 1914 may include a control frame. In an example, the control frame may include an announcement frame. In an example, the announcement frame may include an NDP Announcement (NDPA) frame. In an example, the NDPA frame may include an Ultra-High Reliability (UHR) NDPA frame.

[0258] After transmission frame 1914, STA 1904 may transmit PPDU 1916 to STA 1906. In an embodiment, STA 1904 may transmit PPDU 1916 after transmission frame 1914 at SIFS intervals. In an embodiment, PPDU 1916 may be used by STA 1906 to estimate a second channel from STA 1904 to STA 1906.

[0259] After receiving PPDU 1916, STA 1906 may transmit frame 1918 to STA 1904. In an embodiment, STA 1906 may transmit frame 1918 after receiving PPDU 1916, with an interval of SIFS. In an embodiment, frame 1918 may indicate a second estimate of the second channel. In an example, the second estimate may include a second feedback based on PPDU 1916. In an example, the second feedback may include SU feedback or CQI feedback based on the second feedback type indicated in frame 1914.

[0260] After receiving frame 1918, STA 1904 may transmit frame 1920 to STA 1902. Frame 1920 may be in response to frame 1910. In an embodiment, frame 1920 may include a second estimate of the second channel indicated in frame 1918. In an embodiment, frame 1920 may be used to report a second feedback to STA 1902.

[0261] After transmitting frame 1920, STA 1904 may transmit frame 1922 to STA 1902. In an embodiment, frame 1922 may indicate a first estimate of the first channel. In an embodiment, the first estimate may include a first feedback based on PPDU 1912. In an example, the first feedback may include SU feedback or CQI feedback based on the first feedback type indicated in frame 1910.

[0262] In an embodiment, frames 1918, 1920, and / or 1922 may include management frames. In an example, a management frame may include an action frame. In an example, frame 1922 may include a compressed beamforming report or a CQI report.

[0263] like Figure 19 As shown, according to an embodiment, a single probe sequence can be used to probe the end-to-end relay link between STAs 1902 and 1906. This can significantly reduce the overhead required for probes and the latency of relay data, especially when the first and / or second channels change frequently.

[0264] Figure 20 This is an example illustrating a probe procedure for relay communication according to an embodiment. Example 2000 is provided for illustrative purposes only and is not limiting.

[0265] like Figure 20 As shown, Example 2000 may include STA 2002, 2004, and 2006. In the example, STA 2004 and 2006 may be associated with STA 2002. STA 2002, STA 2004, and / or 2006 may each include a multilink device (MLD).

[0266] In this example, STA 2002 and STA 2004 are within each other's communication range, STA 2002 and STA 2006 are outside each other's communication range, and STA 2004 and STA 2006 are within each other's communication range. In this example, STA 2002 may include an AP. In this example, STA 2002 may include a trunk. In this example, a trunk may include a trunk AP and a trunk STA. In this example, STA 2004 may include a mobile trunk. In this example, STA 2006 may include a non-AP STA.

[0267] In Example 2000, it is assumed that STA 2002 supports relay detection capability. In this example, supporting relay detection capability allows STA 2002 to transmit a first frame (such as frame 2010 described below), which indicates or announces a first PPDU (such as PPDU 2012 described below) to be transmitted by STA 2002; and instructs or triggers a second STA (such as STA 2004) to transmit a second frame (such as frame 2014 described below) to a third STA (such as STA 2006), which indicates or announces a second PPDU (such as PPDU 2016 described below) to be transmitted by the second STA to the third STA. In an embodiment, STA 2002 may include a beamformer. In this example, supporting relay detection capability allows STA 2002 to transmit a first PPDU for estimating a first channel from STA 2002 to the second STA after transmitting the first frame. In this example, supporting relay detection capability allows STA 2002 to receive a frame (such as frame 2020 described below) from the second STA.

[0268] In Example 2000, it is assumed that STA 2004 supports relay detection capability. In this example, supporting relay detection capability allows STA 2004 to receive a first frame (such as frame 2010 described below), which: indicates or announces a first PPDU (such as PPDU 2012 described below) to be transmitted by a second STA (such as STA 2002); and indicates or triggers STA 2004 to transmit a second frame (such as frame 2014 described below) to a third STA (such as STA 2006), which indicates or announces a second PPDU (such as PPDU 2016 described below) to be transmitted by STA 2004 to the third STA. In an embodiment, STA 2004 may include a beam receiver. In this example, supporting relay detection capability allows STA 2004 to transmit a frame (such as frame 2020 described below) to the second STA. In an embodiment, STA 2004 may include a beamformer. In the example, support for relay detection allows STA 2004 to transmit frames / PPDUs (such as frame 2014 and PPDU 2016 described below) to a third STA. In the example, support for relay detection allows STA 2004 to receive a first PPDU for estimating a first channel from the second STA to STA 2004 after receiving the first frame. In the example, support for relay detection allows STA 2004 to transmit a second PPDU for estimating a second channel from STA 2004 to the third STA after transmitting the second frame.

[0269] In this embodiment, before Example 2000 begins, STA 2002 and 2004 may exchange the first frame and the second frame ( Figure 20 (Not shown) to exchange capability information. In an embodiment, the first frame may include capability information of STA 2002, which includes a first indication that STA 2002 supports relay detection capability. In an embodiment, the second frame may include capability information of STA 2004, which includes a second indication that STA 2004 supports relay detection capability. In an embodiment, the first and second frames may be exchanged after association between STA 2002 and 2004. In an embodiment, the first and second frames may include management frames.

[0270] like Figure 20 As shown, Example 2000 allows STA 2002 to transmit frame 2010 to STA 2004 to initiate a probe sequence. In this example, the probe sequence may include estimating a first channel from STA 2002 to STA 2004 and a second channel from STA 2004 to STA 2006. In this example, the probe sequence may include probes for relay communication. In this example, the probe sequence may include reporting feedback on the first / second channel to STA 2002.

[0271] In one embodiment, frame 2010 may indicate or announce PPDU 2012 to be transmitted from STA 2002 to STA 2004. In another embodiment, frame 2010 may further indicate or trigger STA 2004 to transmit frame 2014 to STA 2006. In yet another embodiment, frame 2014 may indicate or announce PPDU 2016 to be transmitted from STA 2004 to STA 2006. In another embodiment, PPDU 2012 or 2016 may include a probe PPDU. In an example, PPDU 2012 or 2016 may include an NDP.

[0272] In one embodiment, frame 2010 may request frame 2020 from STA 2004. In another embodiment, frame 2014 may request frame 2018 from STA 2006. In one example, frame 2010 may indicate a first feedback type for use by frame 2014 and / or a second feedback type for use by frames 2020 and / or 2022. In one example, the first or second feedback type may indicate SU feedback, MU feedback, or CQI feedback. In one example, the second feedback type may be the same as the first feedback type. In another example, the second feedback type may be different from the first feedback type.

[0273] In embodiments, SU feedback may include a compressed beamforming report. In an example, the compressed beamforming report may include an average SNR for each spatial stream and a compressed beamforming feedback matrix, which is used by the transmission beamformer to determine the steering matrix for explicit feedback beamforming. In embodiments, MU feedback includes a compressed beamforming report and a MU-specific beamforming report. In an example, the MU-specific beamforming report may include explicit feedback in the form of ΔSNR. In embodiments, CQI feedback may include a CQI report. In an example, the CQI report may include the average SNR per RU for each spatial stream. In an implementation, each average SNR per RU may include the arithmetic mean (in decibels) of the SNR on the subcarriers of the 26-frequency modulated RUs requesting feedback.

[0274] In an embodiment, frame 2010 may include a control frame. In an example, the control frame may include a notification frame. In an example, the notification frame may include an NDP Notification (NDPA) frame. In an example, the NDPA frame may include an Ultra-High Reliability (UHR) NDPA frame.

[0275] Following transmission frame 2010, STA 2002 may transmit PPDU 2012 to STA 2004. In an embodiment, STA 2002 may transmit PPDU 2012 to STA 2004 after transmission frame 2010, with a SIFS interval. In an embodiment, PPDU 2012 may be used by STA 2004 to estimate the first channel from STA 2002 to STA 2004.

[0276] After receiving PPDU 2012 from STA 2002, STA 2004 may transmit frame 2014 to STA 2006. In an embodiment, STA 2004 may transmit frame 2014 to STA 2006 after receiving PPDU 2012, with an interval of SIFS. In an example, frame 2014 may request frame 2018 from STA 2006. In an example, frame 2014 may indicate a second feedback type for use by frame 2018 based on frame 2010. In an embodiment, frame 2014 may include a control frame. In an example, the control frame may include an announcement frame. In an example, the announcement frame may include an NDP Announcement (NDPA) frame. In an example, the NDPA frame may include an Ultra-High Reliability (UHR) NDPA frame.

[0277] Following transmission frame 2014, STA 2004 may transmit PPDU 2016 to STA 2006. In an embodiment, STA 2004 may transmit PPDU 2016 after transmission frame 2014, with a SIFS interval. In an embodiment, PPDU 2016 may be used by STA 2006 to estimate a second channel from STA 2004 to STA 2006.

[0278] After receiving PPDU 2016, STA 2006 may transmit frame 2018 to STA 2004. In an embodiment, STA 2006 may transmit frame 2018 after receiving PPDU 2016, with an interval of SIFS. In an embodiment, frame 2018 may indicate a second estimate of the second channel. In an example, the second estimate may include a second feedback based on PPDU 2016. In an example, the second feedback may include SU feedback or CQI feedback based on the second feedback type indicated in frame 2014.

[0279] After receiving frame 2018, STA 2004 may transmit frame 2020 to STA 2002. Frame 2020 may respond to frame 2010. In an embodiment, frame 2020 may indicate a first estimate of a first channel. In an embodiment, the first estimate may include first feedback based on PPDU 2012. In an example, the first feedback may include SU feedback or CQI feedback based on the first feedback type indicated in frame 2010. In an embodiment, frame 2020 may include a second estimate of a second channel indicated in frame 2018. In an embodiment, frame 2020 may be used to report second feedback to STA 2002.

[0280] In an embodiment, frames 2018 and / or 2020 may include management frames. In an example, a management frame may include an action frame. In an example, frame 2022 may include a compressed beamforming report or a CQI report.

[0281] like Figure 20 As shown, according to an embodiment, a single probe sequence can be used to probe the end-to-end relay link between STAs 2002 and 2006. This can significantly reduce the overhead required for probes and the latency of relay data, especially when the first channel and / or the second channel changes frequently.

[0282] Figure 21 This is an example illustrating a probe procedure for relay communication according to an embodiment. Example 2100 is provided for illustrative purposes only and is not limiting.

[0283] like Figure 21 As shown, example 2100 may include STAs 2102, 2104, and 2106. In this example, STAs 2104 and 2106 may be associated with STA 2102. STAs 2102, 2104, and / or 2106 may each include a multilink device (MLD).

[0284] In this example, STA 2102 and STA 2104 are within each other's communication range, STA 2102 and STA 2106 are outside each other's communication range, and STA 2104 and STA 2106 are within each other's communication range. In this example, STA 2102 may include an AP. In this example, STA 2102 may include a trunk. In this example, a trunk may include a trunk AP and a trunk STA. In this example, STA 2104 may include a mobile trunk. In this example, STA 2106 may include a non-AP STA.

[0285] In Example 2100, it is assumed that STA 2102 supports relay detection capability. In an embodiment, STA 2102 may include a beamformer. In this example, supporting relay detection capability allows STA 2102 to transmit a first PPDU (such as PPDU 2112 described below) for estimating a first channel from STA 2102 to a second STA. In this example, supporting relay detection capability allows STA 2102 to receive frames from the second STA (such as frame 2122 described below).

[0286] In Example 2100, it is assumed that STA 2104 supports relay detection capability. In an embodiment, STA 2104 may include a beam receiver. In the example, supporting relay detection capability allows STA 2104 to receive a first PPDU (such as PPDU 2112 described below) from a second STA (such as STA 2102) for estimating a first channel from the second STA to STA 2104. In an embodiment, STA 2104 may include a beamformer. In the example, supporting relay detection capability allows STA 2104 to transmit a second PPDU (such as PPDU 2118 described below) for estimating a second channel from STA 2104 to a third STA (such as STA 2106). In an embodiment, supporting relay detection capability allows STA 2104 to receive a frame (such as frame 2120 described below) from the third STA that includes a first estimate of the second channel. In an embodiment, the support for relay detection capability allows STA 2104 to transmit frames (such as frame 2122) to a second STA, the frames including: a second estimate of a first channel; and a first estimate of a second channel.

[0287] In this embodiment, before Example 2100 begins, STA 2102 and 2104 may exchange the first frame and the second frame ( Figure 21(Not shown) to exchange capability information. In an embodiment, the first frame may include capability information of STA 2102, which includes a first indication that STA 2102 supports relay detection capability. In an embodiment, the second frame may include capability information of STA 2104, which includes a second indication that STA 2104 supports relay detection capability. In an embodiment, the first and second frames may be exchanged after association between STA 2102 and 2104. In an embodiment, the first and second frames may include management frames.

[0288] like Figure 21 As shown, in Example 2100, STA 2102 may transmit frame 2110 to STA 2104 to initiate a probe sequence. In this example, the probe sequence may include estimating a first channel from STA 2102 to STA 2104 and a second channel from STA 2104 to STA 2106. In this example, the probe sequence may include probes for relay communication. In this example, the probe sequence may include reporting feedback on the first / second channel to STA 2102.

[0289] In an embodiment, frame 2110 may indicate or announce PPDU 2112 to be transmitted from STA 2102 to STA 2104.

[0290] In an embodiment, frame 2110 may include a control frame. In an example, the control frame may include a notification frame. In an example, the notification frame may include an NDP Notification (NDPA) frame. In an example, the NDPA frame may include an Ultra-High Reliability (UHR) NDPA frame.

[0291] Following transmission frame 2110, STA 2102 may transmit PPDU 2112 to STA 2104. In an embodiment, STA 2102 may transmit PPDU 2112 to STA 2104 after transmission frame 2110 with a SIFS interval. In an embodiment, PPDU 2112 may be used by STA 2104 to estimate a first channel from STA 2102 to STA 2104. In an embodiment, PPDU 2112 may include a probe PPDU. In an example, PPDU 2112 may include an NDP.

[0292] After transmitting PPDU 2112, STA 2102 may transmit frame 2114, which triggers STA 2104 to transmit frame 2116 to STA 2106. In an embodiment, STA 2102 may transmit frame 2114 to STA 2104 after transmitting PPDU 2112 with a SIFS interval.

[0293] In an embodiment, frame 2114 may request frame 2122 from STA 2104. In an example, frame 2114 may indicate a first feedback type for use by frame 2122 and / or a second feedback type for use by frames 2120 and / or 2122. In an example, the first or second feedback type may indicate SU feedback, MU feedback, or CQI feedback. In an example, the second feedback type may be the same as the first feedback type. In another example, the second feedback type may be different from the first feedback type.

[0294] In embodiments, SU feedback may include a compressed beamforming report. In an example, the compressed beamforming report may include an average SNR for each spatial stream and a compressed beamforming feedback matrix, which is used by the transmission beamformer to determine the steering matrix for explicit feedback beamforming. In embodiments, MU feedback includes a compressed beamforming report and a MU-specific beamforming report. In an example, the MU-specific beamforming report may include explicit feedback in the form of ΔSNR. In embodiments, CQI feedback may include a CQI report. In an example, the CQI report may include the average SNR per RU for each spatial stream. In an implementation, each average SNR per RU may include the arithmetic mean (in decibels) of the SNR on the subcarriers of the 26-frequency modulated RUs requesting feedback.

[0295] In an embodiment, frame 2114 may include a control frame. In an example, the control frame may include a trigger frame.

[0296] After receiving frame 2114 from STA 2102, STA 2104 may transmit frame 2116 to STA 2106. In an embodiment, STA 2104 may transmit frame 2116 to STA 2106 after receiving frame 2114, with a SIFS interval. In an embodiment, frame 2116 may indicate or announce PPDU 2118 to be transmitted from STA 2104 to STA 2106. In an example, frame 2116 may request frame 2120 from STA 2106. In an example, frame 2116 may indicate a second feedback type for use by frame 2120 based on frame 2114.

[0297] In an embodiment, frame 2116 may include a control frame. In an example, a control frame may include a notification frame. In an example, a notification frame may include an NDP notification (NDPA) frame.

[0298] Following transmission frame 2116, STA 2104 may transmit PPDU 2118 to STA 2106. In an embodiment, STA 2104 may transmit PPDU 2118 after transmission frame 2116 at an interval of SIFS. In an embodiment, PPDU 2118 may be used by STA 2106 to estimate a second channel from STA 2104 to STA 2106. In an embodiment, PPDU 2118 may include a probe PPDU. In an example, PPDU 2118 may include an NDP.

[0299] After receiving PPDU 2118, STA 2106 may transmit frame 2120 to STA 2104. In an embodiment, STA 2106 may transmit frame 2120 after receiving PPDU 2118, with an interval of SIFS. In an embodiment, frame 2120 may indicate a second estimate of the second channel. In an example, the second estimate may include a second feedback based on PPDU 2118. In an example, the second feedback may include SU feedback or CQI feedback based on the second feedback type indicated in frame 2116.

[0300] After receiving frame 2120, STA 2104 may transmit frame 2122 to STA 2102. Frame 2122 may respond to frame 2114. In an embodiment, frame 2122 may indicate a first estimate of a first channel. In an embodiment, the first estimate may include first feedback based on PPDU 2112. In an example, the first feedback may include SU feedback or CQI feedback based on the first feedback type indicated in frame 2110. In an embodiment, frame 2122 may include a second estimate of a second channel indicated in frame 2120. In an embodiment, frame 2122 may be used to report the first and second feedback to STA 2102.

[0301] In an embodiment, frames 2120 and / or 2122 may include management frames. In an example, a management frame may include an action frame. In an example, frame 2122 may include a compressed beamforming report or a CQI report.

[0302] like Figure 21 As shown, according to an embodiment, a single probe sequence can be used to probe the end-to-end relay link between STAs 2102 and 2106. This can significantly reduce the overhead required for probes and the latency of relay data, especially when the first channel and / or the second channel changes frequently.

[0303] like Figure 21As shown, according to an embodiment, STA 2104 can detect the end-to-end relay link between STA 2102 and 2106 by combining a first estimate of the first channel and a second estimate of the second channel in a single frame 2122. This reduces the delay in reporting the first and second feedbacks to STA 2102.

[0304] Figure 22 This is an example illustrating a probe procedure for relay communication according to an embodiment. Example 2200 is provided for illustrative purposes only and is not limiting.

[0305] like Figure 22 As shown, Example 2200 may include STAs 2202, 2204, and 2206. In this example, STAs 2204 and 2206 may be associated with STA 2202. STAs 2202, STA 2204, and / or STA 2206 may each include a multilink device (MLD).

[0306] In this example, STA 2202 and STA 2204 are within each other's communication range, STA 2202 and STA 2206 are outside each other's communication range, and STA 2204 and STA 2206 are within each other's communication range. In this example, STA 2202 may include an AP. In this example, STA 2202 may include a trunk. In this example, a trunk may include a trunk AP and a trunk STA. In this example, STA 2204 may include a mobile trunk. In this example, STA 2206 may include a non-AP STA.

[0307] In Example 2200, it is assumed that STA 2202 supports relay detection capability. In an embodiment, STA 2202 may include a beamformer. In the example, supporting relay detection capability allows STA 2202 to transmit a first PPDU (such as PPDU 2212 described below) for estimating a first channel from STA 2202 to a second STA. In the example, supporting relay detection capability allows STA 2202 to receive frames (such as frames 2222 and 2226 described below) from the second STA. In the example, supporting relay detection capability allows STA 2202 to transmit frames (such as frame 2224 described below) to the second STA.

[0308] In Example 2200, it is assumed that STA 2204 supports relay detection capability. In an embodiment, STA 2204 may include a beam receiver. In the example, supporting relay detection capability allows STA 2204 to receive a first PPDU (such as PPDU 2212 described below) from a second STA (such as STA 2202) for estimating a first channel from the second STA to STA 2204. In an embodiment, STA 2204 may include a beamformer. In the example, supporting relay detection capability allows STA 2204 to transmit a second PPDU (such as PPDU 2218 described below) for estimating a second channel from STA 2204 to a third STA (such as STA 2206). In an embodiment, supporting relay detection capability allows STA 2204 to receive a frame (such as frame 2220 described below) from the third STA that includes a first estimate of the second channel. In one embodiment, support for relay detection allows STA 2204 to transmit frames (such as frames 2222 and 2226) to a second STA, the frames including: a second estimate of a first channel; and a first estimate of a second channel. In another embodiment, support for relay detection allows STA 2204 to receive frames (such as frame 2224 described below) from a second STA.

[0309] In this embodiment, before Example 2200 begins, STA 2202 and 2204 may exchange the first frame and the second frame ( Figure 22 (Not shown) to exchange capability information. In an embodiment, the first frame may include capability information of STA 2202, which includes a first indication that STA 2202 supports relay detection capability. In an embodiment, the second frame may include capability information of STA 2204, which includes a second indication that STA 2204 supports relay detection capability. In an embodiment, the first and second frames may be exchanged after association between STA 2202 and 2204. In an embodiment, the first and second frames may include management frames.

[0310] like Figure 22 As shown, in Example 2200, STA 2202 may transmit frame 2210 to STA 2204 to initiate a probe sequence. In this example, the probe sequence may include estimating a first channel from STA 2202 to STA 2204 and a second channel from STA 2204 to STA 2206. In this example, the probe sequence may include probes for relay communication. In this example, the probe sequence may include reporting feedback on the first / second channel to STA 2202.

[0311] In an embodiment, frame 2210 may indicate or announce PPDU 2212 to be transmitted from STA 2202 to STA 2204. In an example, frame 2210 may indicate a first feedback type for use by frame 2226. In an example, the first feedback type may include SU feedback, MU feedback, or CQI feedback.

[0312] In embodiments, SU feedback may include a compressed beamforming report. In an example, the compressed beamforming report may include an average SNR for each spatial stream and a compressed beamforming feedback matrix, which is used by the transmission beamformer to determine the steering matrix for explicit feedback beamforming. In embodiments, MU feedback includes a compressed beamforming report and a MU-specific beamforming report. In an example, the MU-specific beamforming report may include explicit feedback in the form of ΔSNR. In embodiments, CQI feedback may include a CQI report. In an example, the CQI report may include the average SNR per RU for each spatial stream. In an implementation, each average SNR per RU may include the arithmetic mean (in decibels) of the SNR on the subcarriers of the 26-frequency modulated RUs requesting feedback.

[0313] In an embodiment, frame 2210 may include a control frame. In an example, the control frame may include a notification frame. In an example, the notification frame may include an NDP Notification (NDPA) frame. In an example, the NDPA frame may include an Ultra-High Reliability (UHR) NDPA frame.

[0314] Following transmission frame 2210, STA 2202 may transmit PPDU 2212 to STA 2204. In an embodiment, STA 2202 may transmit PPDU 2212 to STA 2204 after a SIFS interval following transmission frame 2210. In an embodiment, PPDU 2212 may be used by STA 2204 to estimate a first channel from STA 2202 to STA 2204. In an embodiment, PPDU 2212 may include a probe PPDU. In an example, PPDU 2212 may include an NDP.

[0315] After transmitting PPDU 2212, STA 2202 may transmit frame 2214, which triggers STA 2204 to transmit frame 2216 to STA 2206. In an embodiment, STA 2202 may transmit frame 2214 to STA 2204 after transmitting PPDU 2212 with a SIFS interval.

[0316] In an embodiment, frame 2214 may include a control frame. In an example, the control frame may include a trigger frame.

[0317] After receiving frame 2214 from STA 2202, STA 2204 may transmit frame 2216 to STA 2206. In an embodiment, STA 2204 may transmit frame 2216 to STA 2206 after receiving frame 2214, with a SIFS interval. In an embodiment, frame 2216 may indicate or announce PPDU 2218 to be transmitted from STA 2204 to STA 2206. In an example, frame 2216 may request frame 2220 from STA 2206. In an example, frame 2216 may indicate a second feedback type for use by frame 2220 based on frame 2214.

[0318] In the example, frame 2216 may indicate a second feedback type for use by frames 2222 and 2226. In the example, the second feedback type may include SU feedback, MU feedback, or CQI feedback. In the example, the second feedback type may be the same as the first feedback type. In another example, the second feedback type may be different from the first feedback type.

[0319] In an embodiment, frame 2216 may include a control frame. In an example, a control frame may include a notification frame. In an example, a notification frame may include an NDP notification (NDPA) frame.

[0320] Following transmission frame 2216, STA 2204 may transmit PPDU 2218 to STA 2206. In an embodiment, STA 2204 may transmit PPDU 2218 after transmission frame 2216 at an interval of SIFS. In an embodiment, PPDU 2218 may be used by STA 2206 to estimate a second channel from STA 2204 to STA 2206. In an embodiment, PPDU 2218 may include a probe PPDU. In an example, PPDU 2218 may include an NDP.

[0321] After receiving PPDU 2218, STA 2206 may transmit frame 2220 to STA 2204. In an embodiment, STA 2206 may transmit frame 2220 after receiving PPDU 2218, with an interval of SIFS. In an embodiment, frame 2220 may indicate a second estimate of the second channel. In an example, the second estimate may include a second feedback based on PPDU 2218. In an example, the second feedback may include SU feedback or CQI feedback based on the second feedback type indicated in frame 2216.

[0322] After receiving frame 2220, STA 2204 may transmit frame 2222 to STA 2202. In one embodiment, STA 2204 may transmit frame 2222 after receiving frame 2220, with an interval of SIFS. Frame 2222 may indicate that STA 2204 has received frame 2220. In one embodiment, frame 2222 may include a notification frame. In one embodiment, frame 2222 may include a contention-free (CF) end frame. In another embodiment, frame 2222 may include a data frame.

[0323] After receiving frame 2222, STA 2202 may transmit frame 2224 to STA 2204. In an embodiment, STA 2202 may transmit frame 2224 after receiving frame 2222 at SIFS intervals. In an embodiment, frame 2224 may request frame 2226 from STA 2204.

[0324] After receiving frame 2224, STA 2204 may transmit frame 2226 to STA 2202. In an embodiment, STA 2204 may transmit frame 2226 after receiving frame 2224, with an interval of SIFS. Frame 2226 may respond to frame 2224. In an embodiment, frame 2226 may indicate a first estimate of a first channel. In an embodiment, the first estimate may include first feedback based on PPDU 2212. In an example, the first feedback may include SU feedback or CQI feedback based on the first feedback type indicated in frame 2210. In an embodiment, frame 2222 may include a second estimate of a second channel indicated in frame 2220. In an embodiment, frame 2226 may be used to report the first and second feedback to STA 2202.

[0325] In an embodiment, frames 2220 and / or 2226 may include management frames. In an example, a management frame may include an action frame. In an example, frame 2222 may include a compressed beamforming report or a CQI report.

[0326] like Figure 22 As shown, according to an embodiment, a single probe sequence can be used to probe the end-to-end relay link between STAs 2202 and 2206. This can significantly reduce the overhead required for probes and the latency of relay data, especially when the first channel and / or the second channel changes frequently.

[0327] like Figure 22 As shown, according to an embodiment, STA 2204 can detect the end-to-end relay link between STA 2202 and 2206 by combining a first estimate of the first channel and a second estimate of the second channel in a single frame 2222. This reduces the delay in reporting the first and second feedbacks to STA 2202.

[0328] In an embodiment, Figure 18 Frame 1810 described in the document Figure 19 Frame 1910 as described in the document and Figure 20 The frame 2010 described herein may include a control frame. In the example, a control frame may include a notification frame.

[0329] Figure 23 An example notification frame 2300 that may be used according to an embodiment is shown. For example, notification frame 2300 may be an embodiment of frame 1810, 1910 or 2010.

[0330] In an embodiment, frame 2300 may be used by a first STA to indicate or announce a first PPDU for estimating a first channel from the first STA to the second STA by a second STA, and to indicate or trigger the second STA to announce a second PPDU for estimating a second channel from the second STA to the third STA by a third STA. For example, the first STA may include Figure 20 The STA2002 described in the text Figure 21 STA 2102 or as described in Figure 22 The embodiments of STA 2202 described herein. For example, the second STA may include... Figure 20 STA 2004 as described in the document Figure 21 STA 2104 or as described in Figure 22 The embodiments of STA 2204 described herein. For example, the third STA may include... Figure 20 STA 2006 as described in the document Figure 21 STA 2106 or as described in Figure 22 The embodiment of STA 2206 described herein. In the embodiment, frame 2300 may be further provided by the first STA to indicate or trigger the second STA to announce a second PPDU for the fourth STA to estimate the third channel from the second STA to the fourth STA.

[0331] like Figure 23 As shown, the announcement frame 2300 may include a frame control field, a duration field, a receiver address (RA) field, a transmitter address (TA) field, a probe session token field, a STA information list field, and an FCS field.

[0332] like Figure 23 As shown, the STA information list field of the notification frame 2300 may include STA information field 2302, STA information field 2304, and optional STA information field 2306.

[0333] In an embodiment, the STA information field 2302 includes a STA ID subfield 2308, a partial BW information subfield, a flag subfield 2310, an Nc index subfield, a feedback type and Ng subfield, a disambiguation subfield, a codebook size subfield, and a reserved subfield. In an embodiment, the STA information field 2302 may include first information for supporting relay detection. In an embodiment, the first information may include a notification of a first PPDU. In an embodiment, the notification of the first PPDU may be provided in the STA ID subfield 2308 and / or the flag subfield 2310 of the STA information field 2302.

[0334] For example, in an embodiment, the STA ID subfield 2308 may indicate the identifier of the second STA. In the example, the identifier of the second STA may include the associated identifier (AID) of the second STA. In an embodiment, the flag subfield 2310 may indicate that the STA information field 2302 is being used to announce the first PPDU for estimating the first channel by the second STA.

[0335] In an embodiment, flag subfield 2310 may indicate the presence of one or more subsequent STA information fields following STA information field 2302. For example, flag subfield 2310 may indicate the presence of STA information field 2304, which is used to indicate or trigger a second STA announcement, as indicated in STA ID subfield 2308, for estimating a second PPDU for the second channel by a third STA, as indicated in STA information field 2304. In another example, flag subfield 2310 may further indicate the presence of STA information field 2306, which is used to indicate or trigger a second STA announcement, as indicated in STA information field 2306, for estimating a second PPDU for the third channel by a fourth STA, as indicated in STA information field 2306.

[0336] like Figure 23 As shown, STA information field 2304 has a similar format to STA information field 2302. Specifically, STA information field 2304 may include STA ID subfield 2312 and flag subfield 2314.

[0337] In an embodiment, the STA information field 2304 may include second information for supporting relay detection. In an embodiment, the second information may include information for the second STA to send an announcement of the second PPDU to the third STA. In an embodiment, the announcement of the second PPDU may be provided in the STA ID subfield 2312 and / or the flag subfield 2314 of the STA information field 2304.

[0338] In an embodiment, the STA ID subfield 2312 may indicate an identifier for a third STA. In an example, the identifier for the third STA may include the AID of the third STA.

[0339] In an embodiment, flag subfield 2314 may indicate that: STA information field 2304 is being used by the second STA to send an announcement to the third STA regarding a second PPDU for estimating the second channel by the third STA; and that STA information fields preceding STA information field 2304 (such as STA information field 2302) are being used to announce a first PPDU for estimating the first channel by the second STA. In an embodiment, flag subfield 2314 may be set to the same value as flag subfield 2310 of STA information field 2302.

[0340] In an embodiment, frame 2300 may include a UHR NDPA frame for end-to-end relay detection. In an example, the UHR NDPA frame for end-to-end relay detection may include a UHR relay NDPA frame.

[0341] Figure 24 An example control frame 2400 that may be used according to an embodiment is shown. For example, control frame 2400 may be an embodiment of frame 1810, 1910 or 2010 described above.

[0342] In an embodiment, control frame 2400 may be used by a first STA to indicate or announce a first PPDU for estimation of a first channel from the first STA to the second STA by a second STA, and to indicate or trigger the second STA to announce a second PPDU for estimation of a second channel from the second STA to the third STA by a third STA. For example, the first STA may include Figure 20 The STA2002 described in the text Figure 21 STA 2102 or as described in Figure 22 The embodiments of STA 2202 described herein. For example, the second STA may include... Figure 20 STA 2004 as described in the document Figure 21 STA 2104 or as described in Figure 22 The embodiments of STA 2204 described herein. For example, the third STA may include... Figure 20 STA 2006 as described in the document Figure 21 STA 2106 or as described in Figure 22 The embodiment of STA 2206 described herein. In this embodiment, control frame 2400 may be further provided by the first STA to indicate or trigger the second STA to announce a second PPDU for the fourth STA to estimate the third channel from the second STA to the fourth STA.

[0343] like Figure 24 As shown, control frame 2400 may include a frame control field, a duration field, a receiver address (RA) field, a transmitter address (TA) field, a probe session token field, a STA information list field, and an FCS field.

[0344] like Figure 24 As shown, the STA information list field may contain one or more STA information fields, including STA information field 2402. STA information field 2402 may contain STA ID subfield 2404, partial BW information subfield, flag subfield 2406, Nc index subfield, feedback type and Ng subfield, disambiguation subfield, codebook size subfield, relay probe information subfield 2408, and optional relay probe information subfield 2410.

[0345] In an embodiment, the STA information field 2402 may include information for supporting relay detection. In an embodiment, the information for supporting relay detection may include a first announcement of a first PPDU to be transmitted by the first STA, and information for the second STA to send a second announcement of the second PPDU to the third STA.

[0346] In an embodiment, the first announcement of the first PPDU may be provided in the STA ID subfield 2404 and / or the flag subfield 2406. In an embodiment, the STA ID subfield 2404 may indicate an identifier of the second STA. In an example, the identifier of the second STA may include the AID of the second STA. In an embodiment, the flag subfield 2406 may indicate that the STA information field 2402 contains the first announcement of the first PPDU and information for sending a second announcement of the second PPDU.

[0347] In this embodiment, the information for sending the second PPDU (Second Announcement) can be provided in the relay probe information subfield 2408. In this embodiment, the relay probe information subfield 2408 includes a STA ID subfield 2412, a partial BW information subfield, a flag subfield 2414, an Nc index subfield, a feedback type and Ng subfield, a disambiguation subfield, a codebook size subfield, and a reserved subfield.

[0348] In an embodiment, the STA ID subfield 2412 may indicate an identifier for a third STA. In an example, the identifier for the third STA may include the AID of the third STA.

[0349] In an embodiment, the flag subfield 2414 may indicate that the relay probe information subfield 2408 contains information for sending a second announcement for a second PPDU.

[0350] In an embodiment, the flag subfield 2414 may indicate that: the relay probe information subfield 2408 is being used by the second STA to send a notification for the second PPDU for the third STA to estimate the second channel to the third STA; and the subfield of the STA information field 2402 preceding the relay probe information subfield 2408 is being used to notify the first PPDU for the second STA to estimate the first channel.

[0351] In an embodiment, the flag subfield 2406 may further indicate that the STA information field 2402 contains information for the second STA to send a third announcement by the second STA to the fourth STA regarding a second PPDU used by the fourth STA to estimate the third channel from the second STA to the fourth STA. Therefore, the STA information field 2402 may include a relay probe information subfield 2410, which includes information for sending the third announcement. The relay probe information subfield 2410 may have a format similar to the relay probe information subfield 2408 described above.

[0352] In an embodiment, control frame 2400 may include a UHR NDPA control frame for end-to-end relay detection. In an example, the UHR NDPA control frame for end-to-end relay detection may include a UHR relay NDPA control frame or a UHR enhanced NDPA control frame.

[0353] Figure 25 An example action frame 2500 that may be used according to an embodiment is shown. For example, action frame 2500 may be an embodiment of frame 2020, 2122, or 2226. In the example, action frame 2500 may include a common action frame.

[0354] In an embodiment, action frame 2500 can be used by a first STA to report a first estimate of a first channel from a second STA to the first STA and a second estimate of a second channel from the first STA to a third STA. For example, the first STA may include Figure 20 STA 2004 as described in the document Figure 21 STA 2104 or as described in Figure 22 The embodiments of STA 2204 described herein. For example, the second STA may include... Figure 20 The STA 2002 described in the document Figure 21 STA 2102 or as described in Figure 22 The embodiments of STA 2202 described herein. For example, the third STA may include... Figure 20 STA 2006 as described in the document Figure 21 STA 2106 or as described in Figure 22 The embodiment of STA 2206 described herein.

[0355] In one embodiment, the first estimate of the first channel may include first feedback based on a first PPDU used by a first STA to estimate the first channel. In another embodiment, the first feedback may include a first beamforming report or a first channel quality indication (CQI) report. In another embodiment, the second estimate of the second channel may include second feedback based on a second PPDU used by a third STA to estimate the second channel. In another embodiment, the second feedback may include a second beamforming report or a second CQI report.

[0356] In an embodiment, action frame 2500 may be further used by the first STA to report a third estimate of the third channel from the first STA to the fourth STA. In an embodiment, the third estimate of the third channel may include third feedback based on a second PPDU used by the fourth STA to estimate the third channel. In an embodiment, the third feedback may include a third beamforming report or a third CQI report.

[0357] like Figure 25 As shown, action frame 2500 may include aggregated frames. In an embodiment, action frame 2500 may aggregate action frame 2502 and action frame 2504.

[0358] In one embodiment, action frame 2502 may include first information for supporting relay detection. In another embodiment, the first information may include a first estimate of a first channel.

[0359] In an embodiment, action frame 2502 may have a format similar to the CQI frame 1400 described above. Specifically, action frame 2502 may include a frame control field, a duration field, one or more address fields, a sequence control field, an HT control field, a frame body, and an FCS field. In an embodiment, the frame body of action frame 2502 may include an action field. In an embodiment, the action field of action frame 2502 may include a category subfield indicating that action frame 2502 is used to probe a first channel from the second STA to the first STA. In an example, the action field of action frame 2502 may include an EHT compressed beamforming / CQI action field or a UHR compressed beamforming / CQI action field.

[0360] In an embodiment, action frame 2504 may include second information for supporting relay detection. In an embodiment, the second information may include one or more estimates associated with one or more STAs, such as a second estimate of a second channel associated with a third STA and a third estimate of a third channel associated with a fourth STA.

[0361] like Figure 25As shown, action frame 2504 may include a frame control field, a duration field, one or more address fields, a sequence control field, an HT control field, a frame body, and an FCS field. In an embodiment, the frame body of action frame 2504 may include action field 2506. In an example, action field 2506 may include a relay compressed beamforming / CQI action field.

[0362] In an embodiment, the action field 2506 may include a category subfield 2508, which indicates that the action frame 2504 is used to probe one or more channels, such as a second channel from a first STA to a third STA and a third channel from a first STA to a fourth STA. In an example, the category subfield 2508 may be set to a value for a relay category.

[0363] In an embodiment, the action field 2506 may further include a relay action field 2510, a STA ID field 2512, a MIMO control field 2514, a compressed beamforming report field 2516, a MU-specific beamforming report field 2518, a CQI report field 2520, and an optional additional relay detection report field 2522.

[0364] In an embodiment, the relay action field 2510 may indicate the value of the compressed beamforming / CQI frame format associated with the second probe of the second channel. In an example, the compressed beamforming / CQI frame format associated with the second probe of the second channel may include a relay compressed beamforming / CQI frame format.

[0365] In an embodiment, the STA ID field 2512, MIMO control field 2514, compressed beamforming report field 2516, MU-specific beamforming report field 2518, and CQI report field 2520 may carry information associated with the detection of the second channel.

[0366] In this embodiment, the STA ID field 2512 may indicate an identifier for a third STA. In this example, the identifier for the third STA may include the AID of the third STA. In this example, the third STA may be associated with a second STA.

[0367] In an embodiment, the MIMO control field 2514 may indicate MIMO control information associated with the probe of the second channel. In an embodiment, the MIMO control information may include an Nc index subfield, an Nr index subfield, a BW subfield, a packet subfield, a codebook information subfield, a feedback type subfield, a remaining feedback segment subfield, a first feedback segment subfield, a partial BW information subfield, and a probe dialogue token number subfield.

[0368] In one embodiment, the compressed beamforming report field 2516 may indicate a second beamforming report. In another embodiment, the compressed beamforming report field 2516 may carry the average SNR of each spatial stream associated with the detection of the second channel and the compressed beamforming feedback matrix associated with the detection of the second channel. In this example, the average SNR and / or compressed beamforming feedback matrix of each spatial stream may be used by a transmission beamformer (such as a first STA) to determine the steering matrix for explicit feedback beamforming associated with the detection of the second channel.

[0369] In one embodiment, the MU-specific beamforming report field 2518 may indicate a second beamforming report. In another embodiment, the MU-specific beamforming report field 2518 may carry explicit feedback in the form of ΔSNR associated with the detection of the second channel. In an example, when DL MU-MIMO is used for transmission via the second channel, the transmitting MU beamformer may use the information in the compressed beamforming report field 2516 and the information in the MU-specific beamforming report field 2518 to determine the steering matrix associated with the detection of the second channel.

[0370] In one embodiment, the CQI report field 2520 may indicate a second CQI report. In another embodiment, the CQI report field 2520 may carry the average SNR per resource unit (RU) for each spatial stream associated with the probe of the second channel. In yet another embodiment, the CQI report field 2520 may contain CQI report information associated with the probe of the second channel. In an example, if the feedback type subfield in the MIMO control field 2514 indicates CQI feedback, then the CQI report information may be included in the compressed beamforming / CQI report.

[0371] In an embodiment, an additional relay detection report field 2522 may exist and contains information associated with the detection of the third channel. In an embodiment, the additional relay detection report field 2522 has a similar field format to the STA ID field 2512, MIMO control field 2514, compressed beamforming report field 2516, MU-specific beamforming report field 2518, and CQI report field 2520 described above.

[0372] Figure 26 An example action frame 2600 that may be used according to an embodiment is shown. For example, action frame 2600 may be an embodiment of frame 2020, 2122, or 2226. In the example, action frame 2600 may include a common action frame.

[0373] In an embodiment, action frame 2600 can be used by a first STA to report a first estimate of a first channel from a second STA to the first STA and a second estimate of a second channel from the first STA to a third STA. For example, the first STA may include... Figure 20 STA 2004 as described in the document Figure 21 STA 2104 or as described in Figure 22 The embodiments of STA 2204 described herein. For example, the second STA may include... Figure 20 The STA 2002 described in the document Figure 21 STA 2102 or as described in Figure 22 The embodiments of STA 2202 described herein. For example, the third STA may include... Figure 20 STA 2006 as described in the document Figure 21 STA 2106 or as described in Figure 22 The embodiment of STA 2206 described herein.

[0374] In one embodiment, the first estimate of the first channel may include first feedback based on a first PPDU used by a first STA to estimate the first channel. In another embodiment, the first feedback may include a first beamforming report or a first CQI report. In another embodiment, the second estimate of the second channel may include second feedback based on a second PPDU used by a third STA to estimate the second channel. In another embodiment, the second feedback may include a second beamforming report or a second CQI report.

[0375] In an embodiment, frame 2600 may be further provided by the first STA to report a third estimate of the third channel from the first STA to the fourth STA. In an embodiment, the third estimate of the third channel may include third feedback based on a second PPDU used by the fourth STA to estimate the third channel. In an embodiment, the third feedback may include a third beamforming report or a third CQI report.

[0376] like Figure 26 As shown, action frame 2600 may include a frame control field, a duration field, one or more address fields, a sequence control field, an HT control field, a frame body, and an FCS field.

[0377] like Figure 26 As shown, the frame body of action frame 2600 may include action field 2602. In an embodiment, action field 2602 may include information for supporting relay detection. In an embodiment, the information may include a first estimate of a first channel and a second estimate of a second channel. In an embodiment, the information may further include a third estimate of a third channel. In the example, action field 2602 may be a UHR detection action field.

[0378] In an embodiment, action field 2602 may include a category subfield 2604, which indicates that the action frame is used to probe a first channel from the second STA to the first STA and to probe a second channel from the first STA to the third STA. In an embodiment, category subfield 2604 may further indicate that the action frame is used to probe a third channel from the first STA to the fourth STA. In an example, action field 2602 may include a UHR compressed beamforming / CQI action field. In an example, category subfield 2604 may be set to a value of the UHR category.

[0379] In an embodiment, the action field 2602 may further include an action detail field, which includes a UHR action field 2606, a UHR MIMO control field, a UHR compressed beamforming report field, a UHR MU dedicated beamforming report field and a UHR CQI report field, a relay detection report field 2608 and an optional additional relay detection report field 2610.

[0380] In an embodiment, the UHR action field 2606 may indicate the value of the UHR compressed beamforming / CQI frame format associated with the detection of the first channel and the detection of the second channel. In an example, the UHR compressed beamforming / CQI frame format associated with the detection of the first channel and the detection of the second channel may include the UHR relay compressed beamforming / CQI frame format.

[0381] In an embodiment, the relay detection report field 2608 may include a STA ID field 2612, a MIMO control field 2614, a compressed beamforming report field 2616, a MU-specific beamforming report field 2618, and a channel quality indication (CQI) report field 2620.

[0382] In an embodiment, the UHR MIMO control field, the UHR compressed beamforming report field, the UHR MU dedicated beamforming report field, and the UHR CQI report field may carry information associated with the detection of the first channel.

[0383] In an embodiment, the relay detection report field 2608 may carry information associated with the detection of the second channel.

[0384] In an embodiment, the STA ID field 2612 may indicate an identifier for a third STA. In an example, the identifier for the third STA may include the AID of the third STA. In an example, the third STA may be associated with a second STA.

[0385] In an embodiment, the MIMO control field 2614 may indicate MIMO control information associated with the probe of the second channel. In an embodiment, the MIMO control information may include an Nc index subfield, an Nr index subfield, a BW subfield, a packet subfield, a codebook information subfield, a feedback type subfield, a remaining feedback segment subfield, a first feedback segment subfield, a partial BW information subfield, and a probe dialogue token number subfield.

[0386] In an embodiment, the compressed beamforming reporting field 2616 may carry the average SNR of each spatial stream associated with the detection of the second channel, and the compressed beamforming feedback matrix associated with the detection of the second channel. In an example, the average SNR and / or compressed beamforming feedback matrix of each spatial stream may be used by a transmission beamformer (such as a first STA) to determine the steering matrix for explicit feedback beamforming associated with the detection of the second channel.

[0387] In an embodiment, the MU-specific beamforming report field 2618 may carry explicit feedback in the form of ΔSNR associated with the detection of the second channel. In the example, when DL MU-MIMO is used for transmission via the second channel, the transmission MU beamformer may use the information in the compressed beamforming report field 2616 and the information in the MU-specific beamforming report field 2618 to determine the steering matrix associated with the detection of the second channel.

[0388] In one embodiment, the CQI report field 2620 may carry the average SNR per resource unit (RU) for each spatial stream associated with the second probe of the second channel. In another embodiment, the CQI report field 2620 may contain CQI report information associated with the probe of the second channel. In an example, if the feedback type subfield in the MIMO control field 2614 indicates CQI feedback, the CQI report information may be included in the compressed beamforming / CQI report.

[0389] In an embodiment, an additional relay detection report field 2610 may exist and contains information associated with the detection of the third channel. In an embodiment, the additional relay detection report field 2610 has a similar format to the relay detection report field 2608 described above.

[0390] As those skilled in the art will understand based on the teachings herein, the embodiments described by the examples above can be readily extended to include cases with more than three STAs.

[0391] As those skilled in the art will understand based on the teachings herein, the embodiments described by the examples above can be readily extended to include cases involving more than one relay.

[0392] As those skilled in the art will understand based on the teachings herein, the embodiments described by the examples above can be readily extended to include cases with more than one non-AP STA.

[0393] As will be understood by those skilled in the art based on the teachings herein, the embodiments described by the examples above can be readily extended to scenarios in which any of the APs or STAs may include an MLD, the MLD including at least one associated AP or associated STA.

[0394] Figure 27 An example process 2700 according to an embodiment is shown. Example process 2700 is provided for illustrative purposes only and is not intended to limit the embodiment. Process 2700 may be executed by a first AP.

[0395] like Figure 27 As shown, process 2700 begins with step 2702, which includes the STA receiving a first frame from the second STA, the first frame indicating or announcing a first PPDU to be transmitted by the second STA; and instructing or triggering the first STA to transmit a second frame to the third STA, the second frame indicating or announcing a second PPDU to be transmitted by the first STA to the third STA.

[0396] In an embodiment, step 2702 further includes: receiving a first PPDU from a second STA by a first STA; and transmitting a second PPDU to a third STA by the first STA.

[0397] In an embodiment, the first PPDU or the second PPDU includes a probe PPDU.

[0398] In an embodiment, the first PPDU or the second PPDU includes a null data PPDU (NDP).

[0399] In an embodiment, the first PPDU is used by the first STA to estimate the first channel from the second STA to the first STA.

[0400] In step 2704, process 2700 includes the first STA transmitting the second frame to the third STA.

[0401] In an embodiment, process 2700 further includes the first STA transmitting a third frame indicating a first estimate of the first channel to the second STA.

[0402] In an embodiment, the first estimate includes first feedback based on a first PPDU.

[0403] In an embodiment, transmitting a third frame includes transmitting the third frame before or after transmitting the second frame.

[0404] In one embodiment, transmitting the third frame includes transmitting the third frame at a short inter-frame interval (SIFS) before transmitting the second frame.

[0405] In an embodiment, transmitting the second frame includes transmitting the second frame after receiving the first PPDU.

[0406] In an embodiment, transmitting the second frame includes transmitting the second frame after receiving the first PPDU, with an interval of SIFS.

[0407] In an embodiment, the second frame includes a control frame, which includes a notification frame.

[0408] In this embodiment, the notification frame includes an NDP notification frame.

[0409] In an embodiment, the second PPDU is used by the third STA to estimate the second channel from the first STA to the third STA.

[0410] In an embodiment, transmitting the second PPDU includes transmitting the second PPDU after transmitting the third frame.

[0411] In an embodiment, transmitting the second PPDU includes transmitting the second PPDU after transmitting the third frame at an interval of SIFS.

[0412] In an embodiment, process 2700 further includes: receiving a fourth frame including a second estimate of the second channel from a third STA by a first STA; and transmitting a fifth frame including the second estimate to a second STA by the first STA.

[0413] In an embodiment, the second estimate includes a second feedback based on a second PPDU.

[0414] In this embodiment, the third frame includes the fifth frame.

[0415] In an embodiment, the third, fourth, or fifth frame includes a management frame, which includes an action frame.

[0416] In this embodiment, the action frame indicates a beamforming report or a channel quality indication (CQI) report.

[0417] In this embodiment, the first frame includes a control frame.

[0418] In an embodiment, the control frame includes a notification frame.

[0419] In this embodiment, the notification frame includes an NDP notification frame.

[0420] In this embodiment, the control frame includes a trigger frame.

[0421] In this embodiment, the first frame includes an aggregated frame of an aggregated notification frame and a trigger frame.

[0422] In an embodiment, process 2700 further includes: a first STA receiving a first indication from a second STA that the second STA supports relay detection capability; and the first STA transmitting a second indication that the first STA supports relay detection capability to the second STA.

[0423] Figure 28 An example process 2800 according to an embodiment is illustrated. Example process 2800 is provided for illustrative purposes only and is not intended to limit the embodiment. Process 2800 may be executed by a first AP.

[0424] like Figure 28 As shown, process 2800 begins with step 2802, which includes the STA transmitting a first frame to the second STA, the first frame indicating or announcing a first PPDU to be transmitted by the first STA; and instructing or triggering the second STA to transmit a second frame to the third STA, the second frame indicating or announcing a second PPDU to be transmitted by the second STA to the third STA.

[0425] In an embodiment, step 2802 further includes the first STA transmitting the first PPDU to the second STA.

[0426] In an embodiment, the first PPDU or the second PPDU includes a probe PPDU.

[0427] In an embodiment, the first PPDU or the second PPDU includes a null data PPDU (NDP).

[0428] In an embodiment, the first PPDU is used by the second STA to estimate the first channel from the first STA to the second STA.

[0429] In an embodiment, process 2800 further includes: the first STA receiving a third frame from the second STA indicating a first estimate of the first channel.

[0430] In an embodiment, the first estimate includes first feedback based on a first PPDU.

[0431] In an embodiment, instructing or triggering the second STA to transmit the second frame to the third STA includes: instructing or triggering the second STA to transmit the second frame to the third STA after transmitting the first PPDU.

[0432] In an embodiment, instructing or triggering the second STA to transmit the second frame to the third STA includes: instructing or triggering the second STA to transmit the second frame to the third STA after a SIFS interval following the transmission of the first PPDU.

[0433] In an embodiment, the second frame includes a control frame, which includes a notification frame.

[0434] In this embodiment, the notification frame includes an NDP notification frame.

[0435] In an embodiment, the second PPDU is used by the third STA to estimate the second channel from the first STA to the third STA.

[0436] In an embodiment, the second PPDU to be transmitted from the second STA to the third STA includes the second PPDU to be transmitted from the second STA to the third STA after receiving the third frame.

[0437] In an embodiment, the second PPDU to be transmitted from the second STA to the third STA includes the second PPDU to be transmitted from the second STA to the third STA after receiving the third frame at a SIFS interval.

[0438] In an embodiment, process 2800 further includes the first STA receiving a fourth frame from the second STA, which includes a second estimate of the second channel.

[0439] In an embodiment, the second estimate includes a second feedback based on a second PPDU.

[0440] In this embodiment, the third frame includes the fourth frame.

[0441] In an embodiment, the third or fourth frame includes a management frame, which includes an action frame.

[0442] In this embodiment, the action frame indicates a beamforming report or a channel quality indication (CQI) report.

[0443] In this embodiment, the first frame includes a control frame.

[0444] In an embodiment, the control frame includes a notification frame.

[0445] In this embodiment, the notification frame includes an NDP notification frame.

[0446] In this embodiment, the control frame includes a trigger frame.

[0447] In this embodiment, the first frame includes an aggregated frame of an aggregated notification frame and a trigger frame.

[0448] In an embodiment, process 2800 further includes: a first STA transmitting a first indication that the first STA supports relay detection capability to a second STA; and the first STA receiving a second indication that the second STA supports relay detection capability from the second STA.

[0449] Figure 29 An example process 2900 according to an embodiment is shown. Example process 2900 is provided for illustrative purposes only and is not intended to limit the embodiment. Process 2900 may be executed by a first AP.

[0450] like Figure 29 As shown, process 2900 begins with step 2902, which includes receiving a first PPDU from a second STA by a first STA for estimating a first channel from the second STA to the first STA; transmitting a second PPDU from the first STA to the third STA for estimating a second channel from the first STA to the third STA; receiving a first frame from the third STA by the first STA including a first estimate of the second channel; and transmitting a second frame from the first STA to the second STA, the second frame including: a second estimate of the first channel and a first estimate of the second channel.

[0451] In an embodiment, the second estimate of the first channel includes a first feedback based on the first PPDU.

[0452] In an embodiment, the first estimate of the second channel includes a second feedback based on the second PPDU.

[0453] In an embodiment, the first PPDU or the second PPDU includes a probe PPDU.

[0454] In an embodiment, the first PPDU or the second PPDU includes a null data PPDU (NDP).

[0455] In an embodiment, process 2900 further includes a first STA receiving a third frame from a second STA, the third frame requesting the second frame from the first STA.

[0456] The method of claim 6 further includes transmitting a fourth frame to a second STA before receiving a third frame, the fourth frame indicating that the first STA has received the first frame.

[0457] In an embodiment, process 2900 further includes: a first STA receiving a fifth frame from a second STA announcing the transmission of a first PPDU; the first STA receiving a sixth frame from the second STA, the sixth frame triggering the first STA to transmit a seventh frame to a third STA after receiving the sixth frame, the seventh frame announcing the transmission of a second PPDU; and the first STA transmitting the seventh frame to the third STA.

[0458] In an embodiment, the first frame or the second frame includes a management frame, which includes an action frame.

[0459] In this embodiment, the action frame indicates a beamforming report or a channel quality indication (CQI) report.

[0460] In an embodiment, the third or fourth frame includes a control frame.

[0461] In this embodiment, the third frame includes a trigger frame.

[0462] In this embodiment, the fourth frame includes a contention-free (CF) end frame.

[0463] In this embodiment, the fourth frame includes a data frame.

[0464] In this embodiment, the fourth frame includes a Quality of Service (QoS) empty frame.

[0465] In an embodiment, process 2900 further includes: a first STA receiving a first indication from a second STA that the second STA supports relay detection capability; and the first STA transmitting a second indication that the first STA supports relay detection capability to the second STA.

[0466] As will be understood by those skilled in the art based on the teachings herein, the embodiments described by the above examples can be readily extended to include scenarios including: a first station (STA) receiving a first frame from a second STA, the first frame: requesting the transmission of a first physical layer protocol data unit (PPDU) from the first STA to the second STA; and triggering the first STA to transmit a second frame to a third STA, the second frame requesting the transmission of a second PPDU from the third STA to the first STA; the first STA transmitting the first PPDU to the second STA in response to the first frame; the first STA transmitting the second frame to the third STA; the first STA receiving the second PPDU from the third STA in response to the second frame; and the first STA transmitting a third frame to the second STA, the third frame including an estimate of a second channel based on the second PPDU. In an embodiment, the first PPDU is used to estimate a first channel from the first STA to the second STA. In an embodiment, the second PPDU is used to estimate a second channel from the third STA to the first STA.

Claims

1. A method comprising: The first frame is received by the first STA from the second STA. The first frame is: The first physical layer protocol data unit (PPDU) is indicated to be transmitted by the second STA, wherein the first PPDU is used by the first STA to estimate a first channel from the second STA to the first STA. and The first STA is requested to transmit a second frame to the third STA after receiving the first PPDU. The second frame indicates a second PPDU to be transmitted from the first STA to the third STA, wherein the second PPDU is used by the third STA to estimate a second channel from the first STA to the third STA. The first STA receives the first PPDU from the second STA; After receiving the first PPDU, the first STA transmits the second frame to the third STA. as well as The first STA transmits the second PPDU to the third STA after transmitting the second frame.

2. A method comprising: The first frame is received by the first STA from the second STA. The first frame is: Indicates the first physical layer protocol data unit (PPDU) to be transmitted by the second STA; and The first STA is requested to transmit the second frame to the third STA, and the second frame indicates a second PPDU to be transmitted from the first STA to the third STA; as well as The first STA transmits the second frame to the third STA.

3. The method of claim 2, further comprising: The first STA receives the first PPDU from the second STA; as well as The first STA transmits the second PPDU to the third STA.

4. The method according to any one of claims 2 to 3, wherein the first PPDU or the second PPDU includes a probe PPDU.

5. The method according to any one of claims 2 to 4, wherein the first PPDU or the second PPDU comprises empty data PPDUNDP.

6. The method according to any one of claims 2 to 5, wherein the first PPDU is used by the first STA to estimate a first channel from the second STA to the first STA.

7. The method of claim 6, further comprising the first STA transmitting a third frame indicating a first estimate of the first channel to the second STA.

8. The method of claim 7, wherein the first estimate comprises a first feedback based on the first PPDU.

9. The method according to any one of claims 7 to 8, wherein transmitting the third frame includes transmitting the third frame before or after transmitting the second frame.

10. The method according to any one of claims 7 to 8, wherein the second PPDU is transmitted after the transmission of the third frame.

11. The method of claim 2, wherein transmitting the second frame includes transmitting the second frame after receiving the first PPDU.

12. The method according to any one of claims 2 to 11, wherein the second frame includes a control frame, the control frame including a notification frame.

13. The method of claim 12, wherein the notification frame includes an NDP notification frame.

14. The method according to any one of claims 2 to 13, wherein the second PPDU is transmitted after the second frame is transmitted.

15. The method according to any one of claims 2 to 14, wherein the second PPDU is used by the third STA to estimate a second channel from the first STA to the third STA.

16. The method of claim 15, further comprising: The first STA receives a fourth frame from the third STA, which includes a second estimate of the second channel. as well as The first STA transmits a fifth frame, including the second estimate, to the second STA.

17. The method of claim 16, wherein the second estimate includes second feedback based on the second PPDU.

18. The method according to any one of claims 16 to 17, wherein the third frame includes the fifth frame.

19. The method according to any one of claims 2 to 18, wherein the first frame includes a control frame.

20. The method of claim 19, wherein the control frame includes a notification frame.

21. The method of claim 19, wherein the control frame includes a trigger frame.

22. The method of claim 19, wherein the first frame comprises an aggregated frame of an aggregated notification frame and a trigger frame.

23. The method according to any one of claims 2 to 22, further comprising: The first STA receives a first indication from the second STA that the second STA supports relay detection capability; as well as The first STA transmits a second indication that the relay detection capability supported by the first STA to the second STA.

24. A method comprising: The first frame is transmitted from the first STA to the second STA. The first frame is: The first physical layer protocol data unit (PPDU) is indicated to be transmitted by the first STA, wherein the first PPDU is used by the second STA to estimate a first channel from the first STA to the second STA; and The second STA is requested to transmit a second frame to the third STA after transmitting the first PPDU. The second frame indicates a second PPDU to be transmitted from the second STA to the third STA, wherein the second PPDU is used by the third STA to estimate a second channel from the second STA to the third STA. as well as The first STA transmits the first PPDU to the second STA.

25. A method comprising: The first frame is transmitted from the first STA to the second STA. The first frame is: Indicates the first physical layer protocol data unit (PPDU) to be transmitted by the first STA; and The second STA is requested to transmit the second frame to the third STA, and the second frame indicates the second PPDU to be transmitted by the second STA to the third STA.

26. The method of claim 25, further comprising: The first STA transmits the first PPDU to the second STA.

27. The method according to any one of claims 25 to 26, wherein the first PPDU or the second PPDU includes a probe PPDU.

28. The method according to any one of claims 25 to 27, wherein the first PPDU or the second PPDU comprises empty data PPDUNDP.

29. The method according to any one of claims 25 to 28, wherein the first PPDU is used by the second STA to estimate a first channel from the first STA to the second STA.

30. The method of claim 29, further comprising the first STA receiving a third frame from the second STA indicating a first estimate of the first channel.

31. The method of claim 30, wherein the first estimate comprises a first feedback based on the first PPDU.

32. The method of claim 25, wherein requesting the second STA to transmit the second frame to the third STA comprises: The second STA is triggered to transmit the second frame to the third STA after transmitting the first PPDU.

33. The method according to any one of claims 25 to 32, wherein the second frame includes a control frame, the control frame including a notification frame.

34. The method of claim 33, wherein the notification frame includes an NDP notification frame.

35. The method according to any one of claims 25 to 34, wherein the second PPDU is used by the third STA to estimate a second channel from the second STA to the third STA.

36. The method of claim 35, further comprising: The first STA receives a fourth frame from the second STA, which includes a second estimate of the second channel.

37. The method of claim 36, wherein the second estimate includes second feedback based on the second PPDU.

38. The method according to any one of claims 25 to 37, wherein the first frame includes a control frame.

39. The method of claim 38, wherein the control frame includes a notification frame.

40. The method of claim 39, wherein the notification frame includes an NDP notification frame.

41. The method of claim 38, wherein the control frame includes a trigger frame.

42. The method of claim 38, wherein the first frame comprises an aggregated frame of an aggregated notification frame and a trigger frame.

43. The method according to any one of claims 25 to 42, further comprising: The first STA transmits a first indication that it supports relay detection capability to the second STA; as well as The first STA receives a second indication from the second STA that the second STA supports the relay detection capability.

44. A method comprising: The first STA receives a first physical layer protocol data unit (PPDU) from the second STA for estimating a first channel from the second STA to the first STA by the first STA. The first STA transmits a second PPDU, used by the third STA to estimate the second channel from the first STA to the third STA; The first STA receives a first frame from the third STA, which includes a first estimate of the second channel. as well as The first STA transmits the second frame to the second STA, and the second frame includes: The second estimate of the first channel; as well as The first estimate of the second channel.

45. The method of claim 44, wherein the second estimate of the first channel includes a first feedback based on the first PPDU.

46. ​​The method of claim 44, wherein the first estimate of the second channel includes a second feedback based on the second PPDU.

47. The method according to any one of claims 44 to 46, wherein the first PPDU or the second PPDU includes a probe PPDU.

48. The method according to any one of claims 44 to 47, wherein the first PPDU or the second PPDU comprises empty data PPDUNDP.

49. The method according to any one of claims 44 to 48, further comprising receiving a third frame from the second STA by the first STA, the third frame requesting the second frame from the first STA.

50. The method of claim 49, wherein the third frame includes a trigger frame.

51. The method according to any one of claims 49 to 50, further comprising transmitting a fourth frame to the second STA before the first STA receives the third frame, the fourth frame indicating that the first STA has received the first frame.

52. The method of claim 51, wherein the fourth frame includes a contention-free CF end frame.

53. The method of claim 51, wherein the fourth frame comprises a data frame.

54. The method of claim 51, wherein the fourth frame includes a Quality of Service (QoS) empty frame.

55. The method according to any one of claims 44 to 54, further comprising: The first STA receives the fifth frame from the second STA announcing the transmission of the first PPDU; The first STA receives a sixth frame from the second STA. The sixth frame triggers the first STA to transmit a seventh frame to the third STA after receiving the sixth frame. The seventh frame announces the transmission of the second PPDU. as well as The first STA transmits the seventh frame to the third STA.

56. The method according to any one of claims 44 to 55, further comprising: The first STA receives a first indication from the second STA that the second STA supports relay detection capability; as well as The first STA transmits a second indication that the relay detection capability supported by the first STA to the second STA.

57. An apparatus comprising: One or more processors; as well as A memory that stores instructions, which, when executed by the one or more processors, cause the device to perform the method according to any one of claims 1 to 56.

58. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to any one of claims 1 to 56.

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