Auxiliary relay for low latency communication

Abstract

A first station (STA) transmits, to a second STA and a third STA, a first frame soliciting a first acknowledgement frame from the second STA and a second acknowledgement frame from the third STA. The first frame includes one or more data units. The first STA receives, from the second STA, the first acknowledgement frame. The first STA receives, from the third STA, the second acknowledgement frame. Based on one or more of the first and second acknowledgement frames, transmitting, by the first STA to the second STA, a second frame to trigger transmission, by the second STA to the third STA, of at least one of the one or more data units of the first frame.

Description

TITLEAuxiliary Relay for Low Latency CommunicationCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 601 ,261 , filed November 21 , 2023, which is hereby incorporated by reference in its entirety.BRIEF DESCRIPTION OF THE DRAWINGS

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

[0003] FIG. 1 illustrates example wireless communication networks in which embodiments of the present disclosure may be implemented.

[0004] FIG. 2 is a block diagram illustrating example implementations of a station (STA) and an access point (AP).

[0005] FIG. 3 illustrates an example of a Medium Access Control (MAC) frame format.

[0006] FIG. 4 illustrates an example of a Quality of Service (QoS) null frame indicating buffer status information.

[0007] FIG. 5 illustrates an example format of a physical layer (PHY) protocol data unit (PPDU).

[0008] FIG. 6 illustrates an example that includes buffer status reporting by STAs, scheduling by an AP of uplink multiuser (MU) transmissions, and transmission of scheduled uplink transmissions by the STAs.

[0009] FIG. 7 illustrates an example reference model for a multi-link device (MLD).

[0010] FIG. 8 illustrates an example of an AP MLD and an associated non-AP MLD.

[0011] FIG. 9 illustrates an example of a multi-link setup between an AP MLD and a non-AP MLD.

[0012] FIG. 10 illustrates an example of a traffic identifier (TID)-to-link mapping in a multi-link communication environment.

[0013] FIG. 11 illustrates an example of a sub-1 GHz (S1G) relay architecture.

[0014] FIG. 12 illustrates an example of source-relay-destination link.

[0015] FIG. 13 is an example that illustrates relaying with no transmission opportunity (TXOP) protection.

[0016] FIG. 14 illustrates an example of relaying with Request-to-Send (RTS) / Clear-to-Send (CTS) procedure.

[0017] FIG. 15 illustrates an example in which the use of relay communication may reduce network efficiency.

[0018] FIG. 16 illustrates an example of an auxiliary relay procedure according to an embodiment.

[0019] FIG. 17 illustrates an example of an auxiliary relay procedure according to an embodiment.

[0020] FIG. 18 illustrates an example of an auxiliary relay procedure according to an embodiment.

[0021] FIG. 19 illustrates an example of an auxiliary relay procedure according to an embodiment.

[0022] FIGs. 20A-B illustrate examples of a frame which may be used in embodiments.

[0023] FIG. 21 illustrates an example process according to an embodiment.

[0024] FIG. 22 illustrates another example process according to an embodiment.DETAILED DESCRIPTION

[0025] In the present disclosure, various embodiments are presented as examples of how the disclosed techniques may be implemented and / or how the disclosed techniques may be practiced in environments and scenarios. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope. After reading the description, it will be apparent to one skilled in the relevant art how to implement alternative embodiments. The present embodiments may not be limited by any of the described exemplary embodiments. The embodiments of the present 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 further embodiments within the scope of the disclosure. Any figures which highlight the functionality and advantages, are presented for example purposes only. The disclosed architecture is sufficiently flexible and configurable, such that it may be utilized in ways other than that shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments.

[0026] Embodiments may be configured to operate as needed. The disclosed mechanism may be performed when certain criteria are met, for example, in a station, an access point, a radio environment, a network, a combination of the above, and / or the like. Example criteria may be based, at least in part, on for example, wireless device or network node configurations, traffic load, initial system set up, packet sizes, traffic characteristics, a combination of the above, and / or the like. When the one or more criteria are met, various example embodiments may be applied. Therefore, it may be possible to implement example embodiments that selectively implement disclosed protocols.

[0027] In this disclosure, “a” and “an” and similar phrases are to be interpreted as “at least one” and “one or more.” Similarly, any term that ends with the suffix “(s)” is to be interpreted as “at least one” and “one or more.” In this disclosure, the term “may” is to be interpreted as “may, for example.” In other words, the term “may” is indicative that the phrase following the term “may” is an example of one of a multitude of suitable possibilities that may, or may not, be employed by one or more of the various embodiments. The terms “comprises” and “consists of”, as used herein, enumerate one or more components of the element being described. The term “comprises” is interchangeable with “includes” and does not exclude unenumerated components from being included in the element being described. By contrast, “consists of” provides a complete enumeration of the one or more components of the element being described. The term “based on”, as used herein, may be interpreted as “based at least in part on” rather than, for example, “based solely on”. The term “and / or” as used herein represents any possible combination of enumerated elements. For example, “A, B, and / or C” may represent A; B; C; A and B; A and C; B and C; or A, B, and C.

[0028] If A and B are sets and every element of A is an element of B, 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 {STA 1 , STA2}. The phrase “based on” (or equally “based at least on”) is indicative that the phrase following the term “based on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “in response to” (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to” is an example of one of a multitude of suitable possibilities that may, ormay not, be employed to one or more of the various embodiments. The phrase “depending on” (or equally “depending at least to”) is indicative that the phrase following the phrase “depending on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “employ i n g / u sing” (or equally “employing / using at least”) is indicative that the phrase following the phrase “employing / using” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments.

[0029] The term configured may relate to the capacity of a device whether the device is in an operational or non- operational state. Configured may refer to specific settings in a device that effect the operational characteristics of the device whether the device is in an operational or non-operational state. In other words, the hardware, software, firmware, registers, memory values, and / or the like may be “configured” within a device, whether the device is in an operational or nonoperational state, to provide the device with specific characteristics. Terms such as “a control message to cause in a device” may mean that a control message has parameters that may be used to configure specific characteristics or may be used to implement certain actions in the device, whether the device is in an operational or non-operational state.

[0030] In this disclosure, parameters (or equally called, fields, or Information elements: lEs) may comprise one or more information objects, and an information object may comprise one or more other objects. For example, if parameter (IE) N comprises parameter (IE) M, and parameter (IE) M comprises parameter (IE) K, and parameter (IE) K comprises parameter (information element) J. Then, for example, N comprises K, and N comprises J. In an example embodiment, when one or more messages / frames comprise a plurality of parameters, it implies that a parameter in the plurality of parameters is in at least one of the one or more messages / frames but does not have to be in each of the one or more messages / frames.

[0031] Many features presented are described as being optional through the use of “may” or the use of parentheses. For the sake of brevity and legibility, the present disclosure does not explicitly recite each and every permutation that may be obtained by choosing from the set of optional features. The present disclosure is to be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features may be embodied in seven ways, namely with just one of the three possible features, with any two of the three possible features or with three of the three possible features.

[0032] Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g., hardware with a biological element) or a combination thereof, which may be behaviorally equivalent. For example, modules may 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 or the like) or a modeling / simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. It may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and / or quantum hardware. Examples of programmable hardware comprise: 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, C++ or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardware description language (VHDL) or Verilog that configure connections between internal hardware modules with lesser functionality on a programmable device. The mentioned technologies are often used in combination to achieve the result of a functional module.

[0033] FIG. 1 illustrates example wireless communication networks in which embodiments of the present disclosure may be implemented.

[0034] As shown in FIG. 1, the example wireless communication networks may include an Institute of Electrical and Electronic Engineers (IEEE) 802.11 (WLAN) infra-structure network 102. WLAN infra-structure network 102 may include one or more basic service sets (BSSs) 110 and 120 and a distribution system (DS) 130.

[0035] BSS 110-1 and 110-2 each includes a set of an access point (AP or AP STA) and at least one station (STA or non-AP STA). For example, BSS 110-1 includes an AP 104-1 and a STA 106-1, and BSS 110-2 includes an AP 104-2 and STAs 106-2 and 106-3. The AP and the at least one STA in a BSS perform an association procedure to communicate with each other.

[0036] DS 130 may be configured to connect BSS 110-1 and BSS 110-2. As such, DS 130 may enable an extended service set (ESS) 150. Within ESS 150, APs 104-1 and 104-2 are connected via DS 130and may have the same service set identification (SSID).

[0037] WLAN infra-structure network 102 may be coupled to one or more external networks. For example, as shown in FIG. 1, WLAN infra-structure network 102 may be connected to another network 108 (e.g., 802.X) via a portal 140. Portal 140 may function as a bridge connecting DS 130 of WLAN infra-structure network 102 with the other network 108.

[0038] The example wireless communication networks illustrated in FIG. 1 may further include one or more ad-hoc networks or independent BSSs (I BSSs). An ad-hoc network or I BSS is a network that includes a plurality of STAs that are within communication range of each other. The plurality of STAs are configured so that they may communicate with each other using direct peer-to-peer communication (i.e. , not via an AP).

[0039] For example, in FIG. 1, STAs 106-4, 106-5, and 106-6 may be configured to form a first IBSS 112-1. Similarly, STAs 106-7 and 106-8 may 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. Rather, STAs within an IBSS are managed in a distributed manner. STAs forming an IBSS may be fixed or mobile.

[0040] A STA as a predetermined functional medium may include a medium access control (MAC) layer that complies with an IEEE 802.11 standard. A physical layer interface for a radio medium may be used among the APs and the non- AP stations (STAs). The STA may also be referred to using various other terms, including mobile terminal, wireless device, wireless transmit / receive unit (WTRU), user equipment (UE), mobile station (MS), mobile subscriber unit, or user. For example, the term “user” may be used to denote a STA participating in uplink Multi-user Multiple Input, Multiple Output (MU MIMO) and / or uplink Orthogonal Frequency Division Multiple Access (OFDMA) transmission.

[0041] A physical layer (PHY) protocol data unit (PPDU) may be a composite structure that includes a PHY preamble and a payload in the form of a PLOP service data unit (PSDU). For example, the PSDU may include a PHY Convergence Protocol (PLOP) preamble and header and / or one or more MAC protocol data units (MPDUs). The information provided in the PHY preamble may be used by a receiving device to decode the subsequent data in the PSDU. In instances in which PPDUs are transmitted over a bonded channel (channel formed through channel bonding), the preamble fields may be duplicated and transmitted in each of the multiple component channels. The PHY preamble may include both a legacy portion (or “legacy preamble”) and a non-legacy portion (or “non-legacy preamble”). The legacy preamble may be used for packet detection, automatic gain control and channel estimation, among other uses. The legacy preamble also may generally be used to maintain compatibility with legacy devices. The format of, coding of, and information provided in the non-legacy portion of the preamble is based on the particular IEEE 802.11 protocol to be used to transmit the payload.

[0042] A frequency band may include one or more sub-bands or frequency channels. For example, PPDUs conforming to the IEEE 802.11 n, 802.11 ac, 802.11 ax and / or 802.11 be standard amendments may be transmitted over the 2.4 GHz, 5 GHz, and / or 6 GHz bands, each of which may be divided into multiple 20 MHz channels. The PPDUs may be transmitted over a physical channel having a minimum bandwidth of 20 MHz. Larger channels may be formed through channel bonding. For example, PPDUs may be transmitted over physical channels having bandwidths of 40 MHz, 80 MHz, 160 MHz, or 520 MHz by bonding together multiple 20 MHz channels.

[0043] FIG. 2 is a block diagram illustrating example implementations of a STA 210 and an AP 260. As shown in FIG. 2, STA 210 may include at least one processor 220, a memory 230, and at least one transceiver 240. AP 260 may include at least one processor 270, a memory 280, and at least one transceiver 290. Processor 220 / 270 may be operatively connected to memory 230 / 280 and / or to transceiver 240 / 290.

[0044] Processor 220 / 270 may implement functions of the PHY layer, the MAC layer, and / or the logical link control (LLC) layer of the corresponding device (STA 210 or AP 260). Processor 220 / 270 may include one or more processors and / or one or more controllers. The one or more processors and / or one or more controllers may comprise, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a logic circuit, or a chipset, for example.

[0045] Memory 230 / 280 may include a read-only memory (ROM), a random-access memory (RAM), a flash memory, a memory card, a storage medium, and / or other storage unit. Memory 230 / 280 may comprise one or more non-transitory computer readable mediums. Memory 230 / 280 may store computer program instructions or code that may be executed by processor 220 / 270 to carry out one or more of the operations / embodiments discussed in the present application. Memory 230 / 280 may be implemented (or positioned) within processor 220 / 270 or external to processor 220 / 270. Memory 230 / 280 may be operatively connected to processor 220 / 270 via various means known in the art.

[0046] Transceiver 240 / 290 may be configured to transmit / receive radio signals. In an embodiment, transceiver 240 / 290 may implement a PHY layer of the corresponding device (STA 210 or AP 260). In an embodiment, STA 210 and / or AP 260 may be a multi-link device (MLD), that is a device capable of operating over multiple links as defined bythe IEEE 802.11 standard. As such, STA 210 and / or AP 260 may each implement multiple PHY layers. The multiple PHY layers may be implemented using one or more of transceivers 240 / 290.

[0047] FIG.3 illustrates an example format of a MAC frame. In operation, a STA may construct a subset of MAC frames for transmission and may decode a subset of received MAC frames upon validation. The particular subsets of frames that a STA may construct and / or decode may be determined by the functions supported by the STA. A STA may validate a received MAC frame using the frame check sequence (FCS) contained in the frame and may interpret certain fields from the MAC headers of all frames.

[0048] As shown in FIG. 3, a MAC frame includes a MAC header, a variable length frame body, and a frame check sequence (FCS).

[0049] The MAC header includes a frame control field, an optional duration / ID field, address fields, an optional sequence control field, an optional QoS control field, and an optional HT control field.

[0050] The frame control field includes the following subfields: protocol version, type, subtype, “To DS”, “From DS”, “More Fragments”, retry, power management, “More Data , protected frame, and +HTC.

[0051] The protocol version subfield is invariant in size and placement across all revisions of the IEEE 802.11 standard. The value of the protocol version subfield is 0 for MAC frames.

[0052] The type and subtype subfields together identify the function of the MAC frame. There are three frame types: control, data, and management. Each of the frame types has several defined subtypes. Bits within the subtype subfield are used to indicate a specific modification of the basic data frame (subtype 0). For example, in data frames, 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 data frame, which is a data frame that contains a QoS control field in its MAC header. The second MSB of the subtype field, bit 6 (B6) of the frame control field, when set to 1 in data subtypes, indicates a data frame that contain no frame body field.

[0053] The “To DS” subfield indicates whether a data frame is destined to the distribution system (DS). The “From DS” subfield indicates whether a data frame originates from the DS.

[0054] The “More Fragments” subfield is set to 1 in all data or management frames that have another fragment to follow the MAC service data unit (MSDU), or MAC management protocol data unit (MMPDU) carried by the MAC frame. The “More Fragments” subfield is set to 0 in all other frames in which the “More Fragments” subfield is present.

[0055] The retry subfield is set to 1 in any data or management frame that is a retransmission of an earlier frame. It is set to 0 in all other frames in which the retry subfield is present. A receiving STA uses this indication to aid it in the process of eliminating duplicate frames. These rules do not apply for frames sent by a STA under a block agreement.

[0056] The power management subfield is used to indicate the power management mode of a STA.

[0057] The “More Data” subfield indicates to a STA in power save (PS) mode that bufferable units (BUs) are buffered for that STA at the AP. The “More Data” subfield is valid in individually addressed data or management frames transmittedby an AP to a STA in PS mode. The “More Data” subfield is set to 1 to indicate that at least one additional buffered BU is present for the STA.

[0058] The protected frame subfield is set to 1 if the frame body field contains information that has been processed by a cryptographic encapsulation algorithm.

[0059] The +HTC subfield indicates that the MAC frame contains an HT control field.

[0060] The duration / ID field of the MAC header indicates various contents depending on the frame type and subtype and the QoS capabilities of the sending STA. For example, in control frames of the power save poll (PS-Poll) subtype, the duration / ID field carries an association identifier (AID) of the STA that transmitted the frame in the 14 least significant bits (LSB), with the 2 most significant bits (MSB) set to 1. In other frames sent by STAs, the duration / ID field contains a duration value (in microseconds) which is used by a recipient to update a network allocation vector (NAV). The NAV is a counter that indicates to a STA an amount of time during which the STA must defer from accessing the shared medium.

[0061] Up to four address fields may be present in the MAC frame format. The address fields are used to indicate the basic service set identifier (BSSID), source address (SA), destination address (DA), transmitting address (TA), and receiving address (RA). Certain frames may not contain some of the address fields. Certain address field usage may be specified by the relative position of the address field (1-4) within the MAC header, independent of the type of address present in that field. Specifically, the address 1 field always identifies the intended receiver(s) of the frame, and the address 2 field, where present, always identifies the transmitter of the frame.

[0062] The sequence control field includes two subfields, a sequence number subfield and a fragment number subfield. The sequence number subfield in data frames indicates the sequence number of the MSDU (if not in an Aggregated MSDU (A-MSDU)) or A-MSDU. The sequence number subfield in management frames indicates the sequence number of the frame. The fragment number subfield indicates the number of each fragment of an MSDU or MMPDU. The fragment number is set to 0 in the first or only fragment of an MSDU or MMPDU and is incremented by one for each successive fragment of that MSDU or MMPDU. The fragment number is set to 0 in a MAC protocol data unit (MPDU) containing an A-MSDU, or in an MPDU containing an MSDU or MMPDU that is not fragmented. The fragment number remains constant in all retransmissions of the fragment.

[0063] The QoS control field identifies the traffic category (TC) or traffic stream (TS) to which the MAC frame belongs. The QoS control field may also indicate various other QoS related, A-MSDU related, and mesh-related information about the frame. This information can vary by frame type, frame subtype, and type of transmitting STA. The QoS control field is present in all data frames in which the QoS subfield of the subtype subfield is equal to 1.

[0064] The HT control field is present in QoS data, QoS null, and management frames as determined by the +HTC subfield of the frame control field.

[0065] The frame body field is a variable length field that contains information specific to individual frame types and subtypes. The frame body may include one or more MSDUs or MMPDUs. The minimum length of the frame body is 0 octets.

[0066] The FCS field contains a 32-bit Cyclic Redundancy Check (CRC) code. The FCS field value is calculated over all of the fields of the MAC header and the frame body field.

[0067] FIG. 4 illustrates an example of a QoS null frame indicating buffer status information. A QoS null frame refers to a QoS data frame with an empty frame body. A QoS null frame includes a QoS control field and an optional FIT control field which may contain a buffer status report (BSR) control subfield. A QoS null frame indicating buffer status information may be transmitted by a STA to an AP.

[0068] The QoS control field may include a traffic identifier (TID) subfield, an ack policy indicator subfield, and a queue size subfield (or a transmission opportunity (TXOP) duration requested subfield).

[0069] The TID subfield identifies the TC or TS of traffic for which a TXOP is being requested, through the setting of the TXOP duration requested or queue size subfield. The encoding of the TID subfield depends on the access policy (e.g., Allowed value 0 to 7 for enhanced distributed channel access (EDCA) access policy to identify user priority for either TO orTS).

[0070] The ack policy indicator subfield, together with other information, identifies the acknowledgment policy followed upon delivery of the MPDU (e.g., normal ack, implicit block ack request, no ack, block ack, etc.)

[0071] The queue size subfield is an 8-bit field that indicates the amount of buffered traffic for a given TC or TS at the STA for transmission to the AP identified by the receiver address of the frame containing the subfield. The queue size subfield is present in QoS null frames sent by a STA when bit 4 of the QoS control field is set to 1. The AP may use information contained in the queue size subfield to determine t TXOP duration assigned to the STA or to determine the uplink (UL) resources assigned to the STA.

[0072] In a frame sent by or to a non-High Efficiency (non-HE) STA, the following rules may apply to the queue size value:The queue size value is the approximate total size, rounded up to the nearest multiple of 256 octets and expressed in units of 256 octets, of all MSDUs and A-MSDUs buffered at the STA (excluding the MSDU or A-MSDU contained in the present QoS Data frame) in the delivery queue used for MSDUs and A-MSDUs with TID values equal to the value indicated in the TID subfield of the QoS Control field.A queue size value of 0 is used solely to indicate the absence of any buffered traffic in the queue used for the specified TID.A queue size value of 254 is used for all sizes greater than 64768 octets.A queue size value of 255 is used to indicate an unspecified or unknown size.

[0073] In a frame sent by an HE STA to an HE AP, the following rules may apply to the queue size value.

[0074] The queue size value, QS, is the approximate total size in octets, of all MSDUs and A-MSDUs buffered at the STA (including the MSDUs or A-MSDUs contained in the same PSDU as the frame containing the queue size subfield) in the delivery queue used for MSDUs and A-MSDUs with TID values equal to the value indicated in the TID subfield of the QoS control field.

[0075] The queue size subfield includes a scaling factor subfield in bits B14-B15 of the QoS control field and an unsealed value, UV, in bits B8-B13 of the QoS control field. The scaling factor subfield provides the scaling factor, SF.

[0076] A STA obtains the queue size, QS, from a received QoS control field, which contains a scaling factor, SF, and an unsealed value, UV, as follows:QS =16 *UV, if SF is equal toO;1024 + 256 x W, if SF is equal to 1;17408 + 2048 x W, if SF is equal to 2;148480 + 32768 x UV, if SF is equal to 3 and UV is less than 62;> 2147328, if SF equal to is 3 and UV is equal to 62;Unspecified or Unknown, if SF is equal to 3 and UV is equal to 63.

[0077] The TXOP duration requested subfield, which may be included instead of the queue size subfield, indicates the duration, in units of 32 microseconds (us), that the sending STA determines it needs for its next TXOP for the specified TID. The TXOP duration requested subfield is set to 0 to indicate that no TXOP is requested for the specified TID in the current service period (SP). The TXOP duration requested subfield is set to a nonzero value to indicate a requested TXOP duration in the range of 32 us to 8160 us in increments of 32 us.

[0078] The HT control field may include a BSR control subfield which may contain buffer status information used for UL MU operation. The BSR control subfield may be formed from an access category index (ACI) bitmap subfield, a delta TID subfield, an ACI high subfield, a scaling factor subfield, a queue size high subfield, and a queue size all subfield of the HT control field.

[0079] The ACI bitmap subfield indicates the access categories (ACs) for which buffer status is reported (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 all subfield, and set to 0 otherwise, except that if the ACI bitmap subfield is 0 and the delta TID subfield is 3, then the buffer status of all 8 TIDs is included.

[0080] The delta Tl D subfield, together with the values of the ACI bitmap subfield, indicate the number of Tl Ds for which the STA is reporting the buffer status.

[0081] The ACI high subfield indicates the ACI of the AC for which the BSR is indicated 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.

[0082] The scaling factor subfield indicates the unit SF, in octets, of the queue size high and queue size all subfields.

[0083] The queue size high subfield indicates the amount of buffered traffic, in units of SF octets, for the AC identified by the ACI high subfield, that is intended for the STA identified by the receiver address of the frame containing the BSR control subfield.

[0084] The queue size all subfield indicates the amount of buffered traffic, in units of SF octets, for all ACs identified by the ACI Bitmap subfield, that is intended for the STA identified by the receiver address of the frame containing the BSR control subfield.

[0085] The queue size values in the queue size high and queue size all subfields are the total sizes, rounded up to the nearest multiple of SF octets, of all MSDUs and A-MSDUs buffered at the STA (including the MSDUs or A-MSDUs contained in the same PSDU as the frame containing the BSR control subfield) in delivery queues used for MSDUs and A-MSDUs associated with AC(s) that are specified in the ACI high and ACI bitmap subfields, respectively.

[0086] A queue size value of 254 in the queue size high and queue size all subfields indicates that the amount of buffered traffic is greater than 254 x SF octets. A queue size value of 255 in the queue size high and queue size all subfields indicates that the amount of buffered traffic is an unspecified or unknown size. The queue size value of QoS data frames containing fragments may remain constant even if the amount of queued traffic changes as successive fragments are transmitted.

[0087] MAC service provides peer entities with the ability to exchange MSDUs. To support this service, a local MAC uses the underlying PHY-level service to transport the MSDUs to a peer MAC entity. Such asynchronous MSDU transport is performed on a connectionless basis.

[0088] FIG. 5 illustrates an example format of a PPDU. As shown, the PPDU may include a PHY preamble, a PHY header, a PSDU, and tail and padding bits.

[0089] The PSDU may include one or more MPDUs, such as a QoS data frame, an MMPDU, a MAC control frame, or a QoS null frame. In the case of an MPDU carrying a QoS data frame, the frame body of the MPDU may include a MSDU or an A-MSDU.

[0090] By default, MSDU transport is on a best-effort basis. That is, there is no guarantee that a transmitted MSDU will be delivered successfully. However, the QoS facility uses a traffic identifier (TID) to specify differentiated services on a per-MSDU basis.

[0091] A STA may differentiate MSDU delivery according to designated traffic category (TC) or traffic stream (TS) of individual MSDUs. The MAC sublayer entities determine a user priority (UP) for an MSDU based on a 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 sequence of priorities, with 1 being the lowest value, 7 the highest value, and 0 falling between 2 and 3.

[0092] An MSDU with a particular UP is said to belong to a traffic category with that UP. The UP may be provided with each MSDU at the medium access control service access point (MAC SAP) directly in a UP parameter. An A-MPDU may include MPDUs with different TID values.

[0093] A STA may deliver buffer status reports (BSRs) to assist an AP in allocating UL MU resources. The STA may either implicitly deliver BSRs in the QoS control field or BSR control subfield of any frame transmitted to the AP (unsolicited BSR) or explicitly deliver BSRs in a frame sent to the AP in response to a BSRP Trigger frame (solicited BSR).

[0094] The buffer status reported in the QoS control field includes a queue size value for a given TID. The buffer status reported in the BSR control field includes an ACI bitmap, delta TID, a high priority AC, and two queue sizes.

[0095] A STA may report buffer status to the AP, in the QoS control field, of transmitted QoS null frames and QoS data frames and, in the BSR control subfield (if present), of transmitted QoS null frames, QoS data frames, and management frames as defined below.

[0096] The STA may report the queue size for a given TID in the queue size subfield of the QoS control field of transmitted QoS data frames or QoS null frames; the STA may set the queue size subfield to 255 to indicate an unknown / unspecified queue size for that TID. The STA may aggregate multiple QoS data frames or QoS null frames in an A-MPDU to report the queue size for different TIDs.

[0097] The STA may report buffer status in the BSR control subfield of transmitted frames if the AP has indicated its support for receiving the BSR control subfield.

[0098] A High-Efficiency (HE) STA may report the queue size for a preferred AC, indicated by the ACI high subfield, in the queue size high subfield of the BSR control subfield. The STA may set the queue size high subfield to 255 to indicate an unknown / unspecified queue size for that AC.

[0099] A HE STA may report the queue size for ACs indicated by the ACI bitmap subfield in the queue size all subfield of the BSR control subfield. The STA may set the queue size all subfield to 255 to indicate an unknown / unspecified BSR for those ACs.

[0100] FIG. 6 illustrates an example that includes buffer status reporting by STAs, scheduling by an AP of uplink multiuser (MU) transmissions, and transmission of scheduled uplink transmissions by the STAs.

[0101] As shown, the AP may solicit one or more associated STAs (STA 1 and STA 2) for buffer status by sending a buffer status report poll (BSRP) trigger frame. Upon receiving the BSRP trigger frame, STA 1 and / or STA 2 may each generate a trigger-based (TB) PPDU if the BSRP trigger frame contains, in a User Info field, the 12 LSBs of the STA’s AID.

[0102] STA 1 and / or STA 2 may each include in the TB PPDU one or more QoS null frames. The one or more QoS null frames may contain one or more QoS control fields or one or more BSR control subfields.

[0103] As described earlier, a QoS control field may include a queue size subfield for a TID for which the STA has a queue size to report to the AP. For example, as shown in FIG. 6, STA 1 may respond to the BSRP trigger frame from the AP by transmitting an A-MPDU including multiple QoS null frames. The QoS null frames each indicates, in its respective QoS control field, a queue size for a respective TID, e.g., TID 0 and TID 2. Similarly, STA 2 may respond to the BSRP trigger frame by transmitting an MPDU including a QoS null frame, which indicates a queue size for TID 2 in its QoS control field.

[0104] A BSR control subfield may include a queue size all subfield indicating the queue size for the ACs, indicated by the ACI bitmap subfield, for which the STA has a queue size to report to the AP if the AP has indicated its support for receiving the BSR control subfield. The STA sets a delta TID, a scaling factor, an ACI high, and the queue size high subfields of the BSR Control subfield.

[0105] On receiving the BSRs from STA 1 and STA 2, the AP may transmit a basic trigger frame to allocate UL MU resources to STA 1 and STA 2. In response, STA 1 may transmit a TB PPDU containing QoS data frames with TID 0 and TID 2 and STA 2 may transmit a TB PPDU containing one or more QoS data frame(s) with TID. The AP may acknowledge the transmitted TB PPDUs from STA 1 and STA 2 by sending a multi-STA block ack frame.

[0106] FIG. 7 illustrates an example reference model for a multi-link device (MLD).

[0107] An MLD is an entity capable of managing communication over multiple links. The MLD may be a logical entity and may have more than one affiliated station (STA). An MLD may be an access point MLD (AP MLD) where a STA affiliated with the MLD is an AP STA (or an AP). An MLD may be a non-access point MLD (non-AP MLD) where a STA affiliated with the MLD is a non-AP STA (or an STA).

[0108] Communication across different frequency bands / channels may occur simultaneously, or not, depending on the capabilities of both of the communicating AP MLD and non-AP MLD.

[0109] As shown in FIG. 7, a MLD may have a single MAC service access point (MAC-SAP) to the LLC layer, which includes a MAC data service. The MLD may support multiple MAC sublayers, coordinated by a sublayer management entity (SME). Each AP STA (or non-AP STA) affiliated with an AP MLD (or non-AP MLD) has a different MAC address within the MLD.

[0110] The SME is responsible for coordinating the MAC sublayer management entities (MLMEs) of the affiliated STAs of the MLD to maintain a single robust security network association (RSNA) key management entity as well as a single IEEE 802.1X Authenticator or Supplicant for multi-link operation (MLO).

[0111] Multi-link operation (MLO) procedures allow a pair of MLDs to discover, synchronize, (de)authenticate, (re)associate, disassociate, and manage resources with each other on any common bands or channels that are supported by both MLDs. The Authenticator and the MAC-SAP of an AP MLD may be identified by the same AP MLD MAC address. The Supplicant and the MAC-SAP of a non-AP MLD may be identified by the same non-AP MLD MAC address.

[0112] FIG. 8 illustrates an example of an AP MLD and an associated non-AP MLD.

[0113] As shown, the AP MLD has two affiliated APs (AP1 and AP2), and the non-AP MLD has two affiliated STAs (STA 1 and STA 2). The AP MLD and the non-AP MLD may be communicatively coupled by two links (Link 1 and Link 2.) Link 1 is established between AP1 and STA1, and link 2 is established between AP2 and STA2.

[0114] Generally, the MAC addresses of an MLD and of its affiliated STAs are different from one another. For example, as shown in FIG. 8, the AP MLD may have MAC address M, AP 1 may have MAC address w, and AP2 may have with MAC address x. Similarly, the non-AP MLD may have MAC address P, STA 1 may have MAC address y, and STA2 may have MAC address z.

[0115] As shown in FIG. 8, with each MLD, the MAC sublayer may be further divided into an MLD upper MAC sublayer and an MLD lower MAC sublayer. The MLD upper MAC sublayer (MLD) performs functionalities that are common across all links. The MLD lower MAC sublayer performs functionalities that are local to each link. Some of the functionalities require joint processing of both the MLD upper and the MLD lower MAC sublayers.

[0116] The MLD upper MAC sublayer functions may include:- Authentication, association, and reassociation (between an AP MLD and a non-AP MLD);- Security association (e.g., pairwise master key security association (PMKSA), pairwise transient key security association (PTKSA)) and distribution of group temporal key (GTK) I integrity GTK (IGTK) I beacon IGTK (BIGTK);-Sequence number (SN) I packet number (PN) assignment for frames to be encrypted by pairwise transient key (PTK) for unicast frames;- Encryption / decryption using PTK for unicast frames;- Selection of the MLD lower MAC sublayer for transmission (TID-to-link mapping);- Reordering of packets to ensure in-order delivery per each Block Ack session;- Block Ack scoreboarding for individually addressed frames (in collaboration with the MLD lower MAC sublayer); optionally, the MLD upper MAC sublayer delivers the Block Ack record on one link to the MLD lower MAC sublayer of other links; and- MLD level management information exchange / indication via the MLD lower MAC sublayer

[0117] The MLD lower MAC sublayer functions may include:- Maintenance of link specific GTK / IGTK / BIGTK (between an AP affiliated with the AP MLD and a STA affiliated with the non-AP MLD);- Link-specific encryption / decryption / integrity protection and PN assignment using GTK / IGTK / BIGTK (between an AP affiliated with the AP MLD and a STA affiliated with the non-AP MLD);- Link specific management information exchange / indication (e.g., beacon);- Link specific control information exchange / indication (e.g., RTS / CTS, acknowledgements, etc.);- Power save state and mode;- MAC address filtering for frame reception; and- Block Ack scoreboarding for individually addressed frames (in collaboration with the MLD upper MAC sublayer); optionally, the MLD lower MAC sublayer receives the Block Ack record on the other links from the MLD upper MAC sublayer.

[0118] Multi-link (re)setup between a non-AP MLD and an AP MLD may include an exchange of (re)association request / response frames. A (re)association request / response frame exchange for a multi-link setup may include both frames carrying a basic multi-link element.

[0119] In the (re)association request frame, the non-AP MLD indicates the links that are requested for (re)setup and the capabilities and operational parameters of the requested links. The non-AP MLD may request to (re)set up links with a subset of APs affiliated with the AP MLD. The links that are requested for (re)setup and the capabilities and operation parameters of requested links are independent of existing setup links with an associated AP MLD and the capabilities and operation parameters of setup links.

[0120] In the (re)association response frame, the AP MLD may indicate the requested links that are accepted and the requested links that are rejected for (re)setup and the capabilities and operational parameters of the requested links. TheAP MLD may accept a subset of the links that are requested for (re)setup. The (re)association response frame is sent to the non-AP STA, affiliated with the non-AP MLD, that sent the (re)association request frame.

[0121] An MLD that requests or accepts multi-link (re)setup for any two links ensures that each link is located on a different nonoverlapping channel. After successful multi-link (re)setup between a non-AP MLD and an AP MLD, the non- AP MLD and the AP MLD set up links for multi-link operation, and the non-AP MLD is (re)associated with the AP MLD. For each setup link, the corresponding non-AP STA affiliated with the non-AP MLD is in the same associated state as the non-AP MLD and is associated with a corresponding AP affiliated with the AP MLD. For each setup link, functionalities between a non-AP STA and its associated AP are enabled unless the functionalities have been extended to the MLD level or specified otherwise.

[0122] FIG. 9 illustrates an example of a multi-link setup between an AP MLD and a non-AP MLD. As shown, the AP MLD has three affiliated APs: AP 1 operating in the 2.4 GHz band, AP 2 operating in the 5 GHz band, and AP 3 operating in the 6 GHz band. The non-AP MLD has three affiliated STAs: non-AP STA 1 operating in the 2.4 GHz band, non-AP STA 2 operating in the 5 GHz band, and non-AP STA 3 operating in the 6 GHz band.

[0123] The non-AP MLD may initiate multi-link setup by non-AP STA 1 sending an association request frame to AP 1 affiliated with the AP MLD. In the association request frame, the transmitter address (TA) field is set to the MAC address of non-AP STA 1 and the receiver address (RA) field is set to the MAC address of AP 1. The association request frame includes a basic multi-link element that indicates the MLD MAC address of the non-AP MLD and complete information of non-AP STA 1, non-AP STA 2, and non-AP STA 3. The association request frame may request the setup of three links between the non-AP MLD and the AP MLD (a link between AP 1 and non-AP STA 1, a link between AP 2 and non-AP STA 2, and a link between AP 3 and non-AP STA 3).

[0124] The AP MLD may respond to the requested multi-link setup by AP sending an association response frame to non-AP STA 1 affiliated with the non-AP MLD. In the association response frame, the TA field is set to the MAC address of the AP 1 and the RA field is set to the MAC address of the non-AP STA 1. The association response frame includes a basic multi-link element that indicates the MLD MAC address of the AP MLD and complete information of AP 1, AP 2, and AP 3. The association response frame signals successful multi-link setup by the setup of three links between the non-AP MLD and AP MLD (link 1 between AP 1 and non-AP STA 1, link 2 between AP 2 and non-AP STA 2, and link 3 between AP 3 and non-AP STA 3).

[0125] By default, all TIDs at the non-AP MLD are mapped to all setup links for both uplink and downlink. The TID-to- link mapping mechanism allows an AP MLD and a non-AP MLD that performed or are performing multi-link setup to specify how UL and DL QoS traffic corresponding to different TIDs (e.g., between 0 and 7) may be assigned to the setup links. In a negotiated TID-to-link mapping, a TID may be mapped to a link set, which is a subset of setup links, ranging from a single setup link to all the setup links.

[0126] A setup link is defined as enabled for a non-AP MLD if at least one TID is mapped to that link either in DL or in UL, and is defined as disabled if no TIDs are mapped to that link both in DL and UL. At any point in time, a TID is alwaysmapped to at least one setup link both in DL and UL, which means that a TID-to-link mapping change can only be valid and successful if it does not result in a TID having a mapped link set made of zero setup links.

[0127] By default, all setup links are enabled. If a link is enabled for a non-AP MLD, it may be used for the exchange of individually addressed frames, subject to the power state of the non-AP STA operating on that link. Only MSDUs or A- MSDUs with TIDs mapped to a link may be transmitted on that link in the direction (DL / UL) corresponding to the TID-to- link mapping. Individually addressed management frames and control frames may be sent on any enabled link between an affiliated STA of the non-AP MLD and a corresponding AP of the AP MLD, both in DL and UL.

[0128] If a link is disabled for a non-AP MLD, the link may not be used for the exchange of individually addressed frames between an affiliated STA of the non-AP MLD and a corresponding AP of the AP MLD.

[0129] If a TID is mapped in UL to a set of enabled links for a non-AP MLD, the non-AP MLD may use any link within this set of enabled links to transmit individually addressed MSDUs or A-MSDUs corresponding to that TID.

[0130] If a TID is mapped in DL to a set of enabled links for a non-AP MLD, the non-AP MLD may retrieve individually addressed BUs buffered at the AP MLD that are MSDUs or A-MSDUs corresponding to the TID, on any link of the set of enabled links. Conversely, the AP MLD may use any link within the set of enabled links to transmit individually addressed MSDUs or A-MSDUs corresponding to the TID, subject to the power state of the non-AP STA on each of the used link.

[0131] If the default mode is used, the non-AP MLD may retrieve BUs buffered by the AP MLD on any setup link, though the AP MLD may recommend a link.

[0132] A non-AP MLD may retrieve buffered BUs that are MMPDUs buffered at the AP MLD on any enabled link. An AP MLD may use any enabled link to transmit individually addressed bufferable management frames that are not measurement MMPDUs, subject to the power state of the non-AP STA on the used link.If a STA affiliated with a non-AP MLD is in active mode on a link with a set of TIDs mapped for DL transmission, its associated AP affiliated with the AP MLD may transmit to the STA: MSDUs / A-MSDUs for the set of mapped TIDs for the non-AP MLD; and MMPDUs that are not measurement MMPDUs for the non-AP MLD or its affiliated STAs, unless the frames are transmitted to another STA affiliated with the same non-AP MLD and in active mode.

[0133] As mentioned above, under the default mapping mode, all TIDs are mapped to all setup links for DL and UL, and all setup links are enabled. A non-AP MLD and an AP MLD that perform multi-link setup shall operate under this mode if a TID-to-link mapping negotiation for a different mapping has not occurred, was unsuccessful, or was torn down.

[0134] In a multi-link (re)setup procedure, a non-AP MLD may initiate a TID-to-link mapping negotiation by including a TID-to-link mapping element in a (re)association request frame if an AP MLD has indicated support for TID-to-link mapping negotiation.After receiving the (re)association request frame containing the TID-to-link mapping element, the AP MLD may reply to the (re)association request frame in according to the following rules. The AP MLD can accept the requested TID-to-link mapping indicated in the TID-to-link mapping element in the received (re)association request frame only if it accepts the multi-link (re)setup for all links on which at least one TID is requested to be mapped. In this case, the non-AP MLD does include in the (re)association response frame a TID-to-link mapping element. Otherwise, the non-AP MLD indicatesrejection of the proposed TID-to-link mapping by including in the (re)association response frame a TID-to-link mapping element that suggests a preferred TID-to-link mapping.

[0135] Following a successful multi-link (re)setup, to negotiate a new TID-to-link mapping, an initiating MLD may send an individually addressed TID-to-link mapping request frame to a responding MLD that has indicated support of TID-to- link mapping negotiation.

[0136] On receiving the individually addressed TID-to-link mapping request frame, the responding MLD sends an individually addressed TID-to-link mapping response frame to the initiating MLD according to the following rules. The responding MLD may accept the requested TID-to-link mapping indicated in the TID-to-link mapping element in the received TID-to-link mapping request frame by transmitting a TID-to-link mapping response frame. Otherwise, the responding MLD may indicate rejection of the proposed TID-to-link mapping in the TID-to-link mapping response frame. The responding MLD may suggest a preferred TID-to-link mapping in the TID-to-link mapping response frame by including the TID-to-link mapping element in the TID-to-link mapping response frame.

[0137] An MLD may suggest a preferred TID-to-link mapping to a peer MLD by sending an unsolicited TID-to-link mapping response frame that includes a TID-to-link mapping element.

[0138] When a peer MLD indicates a preferred TID-to-link mapping, an MLD may take into account the preferred TID- to-link mapping when it initiates a new TID-to-link mapping. In addition, an AP MLD may take into account the traffic flow(s) affiliated with the non-AP MLD and the capabilities and constraints (if any) of the non-AP MLD.

[0139] When two MLDs have negotiated a TID-to-link mapping, either MLD may tear down the negotiated TID-to-link mapping by sending an individually addressed TID-to-link mapping teardown frame. After teardown, the MLDs operates in default mapping mode.

[0140] When an MLD successfully negotiates a TID-to-link mapping with a peer MLD, both the MLD and the peer MLD update an uplink and / or downlink TID-to-link mapping information according to the negotiated the TID-to-link mapping.

[0141] When an MLD has successfully negotiated with a peer MLD an uplink and / or downlink TID-to-link mapping in which the bit position of a link mapping field n in the TID-to-link mapping element is set to 0, a TID n shall not be mapped to the link associated with the link ID in uplink and / or downlink. When an MLD has successfully negotiated with a peer MLD an uplink and / or downlink TID-to-link mapping in which the bit position of a link mapping field n in the TID-to-link mapping element is set to 1 , the TID n is mapped to the link associated with the link ID in uplink and / or downlink.

[0142] FIG. 10 illustrates an example of a TID-to-link mapping in a multi-link communication environment. As shown, the multi-link communication environment includes an AP MLD having three affiliated APs and a non-AP MLD having three affiliated STAs.

[0143] During or after multi-link setup, the non-AP MLD and the AP MLD may negotiate a TID-to-link mapping. The TID-to-link mapping maps TIDs at the non-AP MLD in UL and DL to setup links between the AP MLD and the non-AP MLD. For example, as shown in FIG. 10, the TID-to-link mapping may map TIDs 0-6 in both UL and DL to link 1 and TID 7 in both UL and DL to link 2. As such, links 1 and 2 are enabled, and link 3 is disabled. The TID-to-link mappingnegotiation may be performed by exchanging an association request / response frame or a TID-to-link mapping request / response frame between the non-AP MLD and the AP MLD.

[0144] FIG. 11 illustrates an example 1100 of a sub-1 GHz (S1G) relay architecture. Example S1G relay architecture 1100 may be an example according to the S1G relay operation as defined in section 10.54.1 of the IEEE 802.11 standard (“802.11-2020 - IEEE Standard for Information Technology-Telecommunications and Information Exchange between Systems - Local and Metropolitan Area Networks— Specific Requirements - Part 11 : Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications”). As shown in FIG. 11 , example S1 G relay architecture 1100 may include a root AP 1110, relays 1120, 1130 and 1140, and STAs 1150, 1160, 1170, 1180 and 1190.

[0145] S1G relay is a mechanism for expanding the coverage area of an AP, referred to as the root AP. In example S1G relay architecture 1100, the S1 G relay mechanism is being used to expand the coverage area of root AP 1110.

[0146] As shown in FIG. 11, S1G relays 1120, 1130 and 1140 may each comprise a relay AP, a relay STA, and a relay function. The relay STA communicates with an upper BSS, whereas the relay AP communicates with a lower BSS. The relay function performs local reception or selective forwarding of MSDUs between the relay STA and the relay AP, based on destination address. In an example, relays 1120 and 1130 are associated with root AP 1110. Relay 1140 may be associated with relay 1120. In an example, STA 1150 is associated with relay 1120. STAs 1160 and 1170 may be associated with relay 1140. STAs 1180 and 1190 may be associated with relay 1130.

[0147] In an example, frames from STA 1150 are forwarded via the relay function of relay 1120 (from the relay AP to the relay STA of relay 1120) to root AP 1110. In the reverse direction, frames from root AP 1110 are forwarded to STA 1150 via the relay function of relay 1120 (from the relay STA to the relay AP of relay 1120). Similarly, STAs 1180 and 1190 may communicate with root AP 1110 via relay 1130 in both directions (e.g., uplink and downlink). On the other hand, STAs 1160 and 1170 may use relays 1140 and 1120 consecutively to communicate with root AP 1110.

[0148] FIG. 12 illustrates an example 1200 of a source-relay-destination link. As shown in FIG. 12, source-relay- destination link 1200 may comprise a STA 1210 as a source STA, a STA 1220 as a destination STA, and a relay 1230.

[0149] STA 1210 may be a non-AP STA or an AP STA. Similarly, STA 1220 may be a non-AP STA or an AP STA. Relay 1230 may comprise a relay AP, a relay STA, and a relay function as described in FIG. 12 above. In an embodiment, STA 1210 may be an AP STA and STA 1220 may be a non-AP STA, or vice versa. In another embodiment, STAs 1210 and 1220 both may be AP STAs or non-AP STAs. STAs 1210 and 1220 may communicate directly.

[0150] Due to unreliable communication or to extend the range of existing communication, source STA 1210 may use relay 1230 to communicate with a destination STA 1220. As such, STA 1210 may transmit data frames destined to STA 1220 via relayl 230. Source STA 1210 and / or the relay 1230 may choose to protect the transmitted data frames with TXOP protection while relaying the data frames via relay 1230. In another embodiment, source STA 1210 and / or relay 1230 may choose not to protect the data frames with TXOP protection while relaying the data frames via relay 1230.

[0151] FIG. 13 is an example 1300 that illustrates relaying with no transmission opportunity (TXOP) protection. Example 1300 may be an example according to the TXOP sharing procedures for S1 G relay operation as defined in section 10.54.5 of the IEEE 802.11 standard (“802.11-2020 - IEEE Standard for Information Technology-Telecommunications andInformation Exchange between Systems - Local and Metropolitan Area Networks— Specific Requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications”). As shown in FIG. 8, example 1300 may include STAs 1310 and 1312 and relay 1311.

[0152] In example 1300, STA 1310 may be a STA that supports TXOP sharing procedures. As shown in FIG. 13, STA 1310 may transmit a data frame 1320 destined to STA 1312 via relay 1311. Data frame 1320 may be a protocol version 1 (PV1) QoS data frame. In an implementation, STA 1310 may set a Relayed Frame field in a Frame Control field of data frame 1320 to 1. The Relayed Frame field set to 1 indicates a relay-shared TXOP. On receiving data frame 1320 with the Relay Frame field set to 1, relay 1311 may transmit an ACK frame 1321 if an explicit ACK procedure is used. Alternatively, relay 1311 may not transmit an ACK frame if an implicit ACK procedure is used.

[0153] In example 1300, relay 1311 may transmit data frame 1322 to STA 1312 without protecting data frame 1322. STA 1312 may transmit an ACK frame 1323 after receiving data frame 1322 from relay 1311. Relaying without TXOP protection may allow a lower latency transmission of data frame 1320 from STA 1310 to STA 1312. However, communication may be less reliable in case that other STAs of the same BSS may be present within the communication ranges of STAs 1310, 1312 and relay 1311. To improve communication reliability, an RTS / CTS procedure may be used to protect relayed data frames as further described below.

[0154] FIG. 14 is an example 1400 that illustrates relaying with TXOP protection. Example 1400 may be an example according to the TXOP sharing procedures for S1G relay operation as defined in section 10.54.5 of the IEEE 802.11 standard (“802.11-2020 - IEEE Standard for Information Technology-Telecommunications and Information Exchange between Systems - Local and Metropolitan Area Networks— Specific Requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications”). As shown in FIG. 14, example 1400 may include STAs 1410 and 1412 and relay 1411.

[0155] In an example, STA 1410 may be a STA that supports TXOP sharing procedures. Before transmitting a data frame 1422 to relay 1411, STA 1410 may transmit an RTS frame 1420 to Relay 1411. Relay 1411 may respond to RTS frame 1420 by transmitting a CTS frame 1421 to STA 1410, if its NAV indicates idle. Upon receiving CTS frame 1421, STA 1410 may transmit data frame 1422 to relay 1411. Relay 1411 may transmit an ACK frame 1423 if an explicit ACK procedure is used. Alternatively, Relay 1411 may not transmit an ACK frame if an implicit ACK procedure is used.

[0156] Similarly, before relaying received data frame 1422 onto STA 1412, Relay 1411 may transmit an RTS frame 1424 to STA 1412. STA 1412 may respond to RTS frame 1424 by transmitting a CTS frame 1425 to relay 1411, if its NAV indicates idle. Upon receiving CTS frame 1425, Relay 1411 may transmit a data frame 1426 (relay of data frame 1422) to STA 1412. STA 1412 may transmit an ACK frame 1427 to relay 1411 after receiving data frame 1426.

[0157] FIG. 15 illustrates an example 1500 in which the use of relay communication may reduce network efficiency. As shown in FIG. 15, example 1500 includes a STA 1510, a relay 1511 and a STA 1512. Relay 1511 may have a relay architecture as described above in FIG. 11. Alternatively, relay 1511 may be a STA (AP STA or non-AP STA) configured to perform relay functions. In example 1500, relay 1511 may be configured to relay traffic from STA 1510 to STA 1512.

[0158] In example 1500, STA 1510 may have first data for transmission to STA 1512. STA 1510 may wish or may be configured to transmit the first data to STA 1512 via relay 1511. STA 1510 may be further configured to protect the transmission of the first data to relay 1511 using the RTS / CTS procedure. As such, as shown in FIG. 15, example 1500 begins with STA 1510 transmitting an RTS frame 1520 to relay 1511. With its NAV indicating idle, relay 1511 responds to RTS frame 1520 by transmitting a GTS frame 1521 to STA 1510. Upon receiving GTS frame 1521, STA 1510 transmits a data frame 1522 to relay 1511. Data frame 1522 may contain a portion of the first data.

[0159] In example 1500, STA 1512 may be within the communication range of STA 1510 and / or Relay 1511. On hearing RTS frame 1520 and / or GTS frame 1521 , STA 1512 may set its NAV for the duration indicated in RTS frame 1520 and / or GTS frame 1521 and may remain idle as STA 1510 transmits data frame 1522 to relay 1511. If STA 1512 happens to be within the communication range of STA 1510 such that STA 1512 is able to successfully decode data frame 1522, STA 1512 may be able to obtain the first data transmitted in data frame 1522. Subsequent frame transmissions of the relay procedure, including an ACK frame 1523 from Relay 1511 to STA 1510, an RTS frame from relay 1511 to STA 1512, a CTS frame from STA 1512 to relay 1511, a data frame 1526 (containing the same portion of the first data as data frame 1522) from relay 1511 to STA 1512, and an ACK frame from STA 1512 to relay 1511, become redundant as STA 1512 has already received the data which transmission these frames are intended to enable.

[0160] Embodiments of the present disclosure, as further discussed below, address the above-described inefficiency of existing relay procedures. In one aspect, a first STA transmits to a second STA and a third STA a first frame, comprising one or more data units, soliciting a first acknowledgement frame from the second STA and a second acknowledgement frame from the third STA. The first STA may be a source STA, the second STA may be a relay, and the third STA may be a destination STA of a relay communication. The first STA receives from the second STA the first acknowledgement frame and receives from the third STA the second acknowledgement frame. Based on one or more of the first and second acknowledgement frames, the first STA transmits to the second STA, a second frame to trigger transmission, by the second STA to the third STA, of at least one of the one or more data units of the first frame. In another aspect, a first STA receives from a second STA, a first frame, comprising one or more data units, soliciting a first acknowledgement frame from the first STA and a second acknowledgement frame from a third STA. The first STA may be a relay, the second STA may be a source STA, and the third STA may be a destination STA of a relay communication. The first STA transmits to the second STA the first acknowledgement frame, and, after transmitting the first acknowledgement frame, the first STA receives from the second STA, a second frame to trigger transmission, by the first STA to the third STA, of one or more data units of the first frame. Accordingly, the first STA may control whether the second STA relays one or more data units of the first frame to the third STA, based on a reception status of the first frame at the third STA.

[0161] FIG. 16 illustrates an example 1600 of an auxiliary relay procedure according to an embodiment. As shown in FIG. 16, example 1600 may include a STA 1610, a STA 1612, and a relay 1611. Relay 1611 may have a relay architecture as described above in FIG. 11. Alternatively, relay 1611 may be a STA (AP STA or non-AP STA) configured to perform relay functions. In example 1600, relay 1611 may be configured to relay traffic from STA 1610 to STA 1612.

[0162] In example 1600, STA 1610 may have first data for transmission to STA 1612. STA 1610 may wish or may be configured to transmit the first data to STA 1612 via relay 1611. STA 1610 may be further configured to protect the transmission of the first data to relay 1611 using an RTS / CTS procedure. It is further assumed in example 1600 that STA 1612 may be within the communication range of STA 1612.

[0163] As shown in FIG. 16, example 1600 begins with STA 1610 transmitting an MU-RTS trigger frame 1620 to relay 1611 and STA 1612. MU-RTS trigger frame 1620 triggers the transmission of GTS frame(s) from relay 1611 and STA 1612. Upon receiving MU-RTS trigger frame 1620, with its NAV indicating idle, relay 1611 transmits a GTS frame 1621 to STA 1610. Similarly, STA 1612 transmits a GTS frame 1622 to STA 1612, based on its NAV indicating idle.

[0164] Upon receiving GTS frames 1621 1622, STA 1610 may transmit a data frame 1623 to both relay 1611 and STA 1612. In an embodiment, data frame 1623 may include an indication that both relay 1611 and STA 1612 shall decode the data contained in data frame 1623. In an embodiment, data frame 1623 may solicit an acknowledgement frame from both relay 1611 and STA 1612. In an implementation, data frame 1623 may comprise a first field for soliciting an acknowledgement from STA 1612. The first field may be provided in a physical layer (PHY) header of data frame 1623. In another implementation, the first field may be provided in a medium access control (MAC) header of a first MPDU of data frame 1623. In another embodiment, data frame 1623 may further comprise a second field to indicate that relay 1611 is an auxiliary relay. An auxiliary relay as used herein refers to a STA configured to perform a relay function in response to one or more conditions being true. The one or more conditions may be based on or more frames received from another STA (e.g., trigger frame, acknowledgment frame, etc.) as further described below. In an implementation, the second field may be provided in a PHY header of data frame 1623. In another implementation, the second field may be provided in a MAC header of the first MPDU of data frame 1623. In another embodiment, data frame 1623 may further comprise a third field for indicating a receiver address of data frame 1623. In an implementation, the receiver address is set to an address of relay 1611.

[0165] Upon receiving data frame 1623, STA 1612 may transmit an ACK frame 1624. ACK frame 1624 may comprise a positive acknowledgment or a negative acknowledgment. In an implementation, ACK frame 1624 may comprise a block acknowledgement frame, which indicates the reception status of data units contained in data frame 1623. The data units may be MPDUs.

[0166] Upon receiving data frame 1623, relay 1611 may transmit an ACK frame 1625. ACK frame 1625 may comprise a positive acknowledgment or a negative acknowledgment. In an implementation, ACK frame 1625 may comprise a block acknowledgement frame, which indicates the reception status at relay 1611 of the data units contained in data frame 1623.

[0167] Based on receiving ACK frame 1624 and ACK frame 1625, STA 1610 may compare the reception status of the data units of data frame 1623 by STA 1612 and relay 1611. Specifically, STA 1710 may determine if one or more data units of data frame 1623 were received in error by STA 1612 but successfully by relay 1611. If so, STA 1610 may transmit a trigger frame 1626 to relay 1611 to trigger transmission by relay 1611 to STA 1612 of those one or more data units. Trigger frame 1626 may indicate the one or more data units of data frame 1623 to be transmitted by relay 1611 to STA1612. Upon receiving trigger frame 1626, relay 1611 transmits a data frame 1627 which includes the one or more data units indicated in trigger frame 1626. Upon receiving data frame 1627, STA 1612 may transmit an ACK frame 1628 to relay 1611. ACK frame 1628 may comprise a positive acknowledgment or a negative acknowledgment. ACK frame 1628 may comprise a block acknowledgement frame.

[0168] In example 1600, if all data units are received correctly by the STA 1612, after the reception of the ACK frame 1624, STA 1610 may not send a trigger frame. In another embodiment if STA 1610 did not receive ACK frame 1624, it may assume that all data units in data frame 1623 receive incorrectly.

[0169] Accordingly, as described above, relay 1611 may only transmit data frame 1627 toSTA 1612 when one or more of the data units of data frame 1623 are received in error by STA 1612. In other words, relay 1611 does not transmit any frame to STA 1612 when STA 1612 receives all the data units of data frame 1623 successfully. This eliminates the transmission by relay 1611 of one of more frames (e.g., frames 1524, 1525, 1526, and 1527) which transmission is superfluous or unnecessary in light of the successful reception of data frame 1623 by STA 1612. Communication efficiency is thereby improved.

[0170] FIG. 17 illustrates an example 1700 of an auxiliary relay procedure according to an embodiment. As shown in FIG. 17, example 1700 may include a STA 1710, a STA 1712, and a relay 1711. Relay 1711 may have a relay architecture as described above in FIG. 11. Alternatively, relay 1711 may be a STA (AP STA or non-AP STA) configured to perform relay functions. In example 1700, relay 1711 may be configured to relay traffic from STA 1710 to STA 1712.

[0171] In example 1700, STA 1710 may have first data for transmission to STA 1712. STA 1710 may wish or may be configured to transmit the first data to STA 1712 via relay 1711. STA 1710 may be further configured to protect the transmission of the first data to relay 1711 using an RTS / CTS procedure. It is further assumed in example 1700 that STA 1712 may be within the communication range of STA 1712.

[0172] As shown in FIG. 17, example 1700 begins with STA 1710 transmitting an MU-RTS trigger frame 1720 to relay 1711 and STA 1712. MU-RTS trigger frame 1720 triggers the transmission of CTS frame(s) from relay 1711 and STA 1712. Upon receiving MU-RTS trigger frame 1720, with its NAV indicating idle, relay 1711 transmits a CTS frame 1721 to STA 1710. Similarly, STA 1712 transmits a CTS frame 1722 to STA 1712, based on its NAV indicating idle.

[0173] Upon receiving CTS frames 1721 1722, STA 1710 may transmit a data frame 1723 to both relay 1711 and STA 1712. In an embodiment, data frame 1723 may include an indication that both relay 1711 and STA 1712 shall decode the data contained in data frame 1623. In an embodiment, data frame 1723 may solicit an acknowledgement frame from both relay 1711 and STA 1712. In an implementation, data frame 1723 may comprise a first field for soliciting an acknowledgement from STA 1712. The first field may be provided in a physical layer (PHY) header of data frame 1723. In another implementation, the first field may be provided in a medium access control (MAC) header of a first MPDU of data frame 1723. In another embodiment, data frame 1723 may further comprise a second field to indicate that relay 1711 is an auxiliary relay. In an implementation, the second field may be provided in a PHY header of data frame 1723. In another implementation, the second field may be provided in a MAC header of the first MPDU of data frame 1723. Inanother embodiment, data frame 1723 may further comprise a third field for indicating a receiver address of data frame 1723. In an implementation, the receiver address is set to an address of relay 1711.

[0174] Upon receiving data frame 1723, STA 1712 may transmit an ACK frame 1724. ACK frame 1724 may comprise a positive acknowledgment or a negative acknowledgment. In an implementation, ACK frame 1724 may comprise a block acknowledgement frame, which indicates the reception status of data units contained in data frame 1723. The data units may be MPDUs.

[0175] Upon receiving ACK frame 1724, STA 1710 may check if all the data units of data frame 1723 were received correctly by STA 1712. If one or more data units were received in error, STA 1710 may transmit an ACK request frame1725 to relay 1711 to obtain the reception status of data units of data frame 1723 by relay 1711. In an implementation, ACK request frame 1725 requests the reception status at relay 1711 of all the data units of data frame 1723. In another implementation, ACK request frame 1725 requests the reception status at relay 1711 of only those data units received in error by STA 1712. In an implementation, tf STA 1710 does not receive ACK frame 1724 from STA 1712, STA 1710 may assume that all data units of data frame 1723 were received in error by STA 1712.

[0176] Upon receiving ACK request frame 1725, relay 1711 may transmit an ACK frame 1726 to STA 1710. ACK frame1726 may comprise a positive acknowledgment or a negative acknowledgment. ACK frame 1726 may comprise a block acknowledgement frame. In an implementation, ACK frame 1726 includes the reception status at relay 1711 of all the data units of data frame 1723. In another implementation, ACK frame 1726 includes the reception status at relay 1711 of only those data units received in error by STA 1712 as indicated by ACK request frame 1725.

[0177] Based on receiving ACK frame 1724 and ACK frame 1726, STA 1710 may compare the reception status of the data units of data frame 1723 by STA 1712 and relay 1711. Specifically, STA 1710 may determine if one or more data units of data frame 1723 were received in error by STA 1712 but successfully by relay 1711. If so, STA 1710 may transmit a trigger frame 1727 to relay 1711 to trigger transmission by relay 1711 to STA 1712 of those one or more data units. Trigger frame 1727 may indicate the one or more data units of data frame 1723 to be transmitted by relay 1711 to STA 1712. Upon receiving trigger frame 1727, relay 1711 transmits a data frame 1728 which includes the one or more data units of data frame 1723 indicated trigger frame 1727. Upon receiving data frame 1728, STA 1712 may transmit an ACK frame 1729 to relay 1711. ACK frame 1729 may comprise a positive acknowledgment or a negative acknowledgment. ACK frame 1729 may comprise a block acknowledgement frame.

[0178] FIG. 18 illustrates an example 1800 of an auxiliary relay procedure according to an embodiment. As shown in FIG. 18, example 1800 may include a STA 1810, a STA 1812, and a relay 1811. Relay 1811 may have a relay architecture as described above in FIG. 11. Alternatively, relay 1811 may be a STA (AP STA or non-AP STA) configured to perform relay functions. In example 1800, relay 1811 may be configured to relay traffic from STA 1810 to STA 1812.

[0179] In example 1800, STA 1810 may have first data for transmission to STA 1812. STA 1810 may wish or may be configured to transmit the first data to STA 1812 via relay 1811. STA 1810 may be further configured to protect the transmission of the first data to relay 1811 using an RTS / CTS procedure. It is further assumed in example 1800 that STA 1812 may be within the communication range of STA 1812.

[0180] As shown in FIG. 18, example 1800 begins with STA 1810 transmitting an MU-RTS trigger frame 1820 to relay 1811 and STA 1812. MU-RTS trigger frame 1820 triggers the transmission of GTS frame(s) from relay 1811 and STA 1812. Upon receiving MU-RTS trigger frame 1820, with its NAV indicating idle, relay 1811 transmits a GTS frame 1821 to STA 1810. Similarly, STA 1812 transmits a GTS frame 1822 to STA 1812, based on its NAV indicating idle.

[0181] Upon receiving GTS frames 1821 1822, STA 1810 may transmit a data frame 1823 to both relay 1811 and STA 1812. In an embodiment, data frame 1823 may include an indication that both relay 1811 and STA 1812 shall decode the data contained in data frame 1823. In an embodiment, data frame 1823 may solicit an acknowledgement frame from both relay 1811 and STA 1812. In an implementation, data frame 1823 may comprise a first field for soliciting an acknowledgement from STA 1812. The first field may be provided in a physical layer (PHY) header of data frame 1823. In another implementation, the first field may be provided in a medium access control (MAC) header of a first MPDU of data frame 1823. In another embodiment, data frame 1823 may further comprise a second field to indicate that relay 1811 is an auxiliary relay In an implementation, the second field may be provided in a PHY header of data frame 1823. In another implementation, the second field may be provided in a MAC header of the first MPDU of data frame 1823. In another embodiment, data frame 1823 may further comprise a third field for indicating a receiver address of data frame 1823. In an implementation, the receiver address is set to an address of relay 1811.

[0182] Upon receiving data frame 1823, STA 1812 may transmit an ACK frame 1824. ACK frame 1824 may comprise a positive acknowledgment or a negative acknowledgment. In an implementation, ACK frame 1824 may comprise a block acknowledgement frame, which indicates the reception status of data units contained in data frame 1823. The data units may be MPDUs.

[0183] Upon receiving ACK frame 1824, STA 1810 may check if all the data units of data frame 1823 were received correctly by STA 1812. If one or more data units were received in error, STA 1810 may transmit an ACK request frame1825 to relay 1811 to obtain the reception status of data units of data frame 1823 by relay 1811. In an implementation, ACK request frame 1825 requests the reception status at relay 1811 of all the data units of data frame 1823. In another implementation, ACK request frame 1825 requests the reception status at relay 1811 of only those data units received in error by STA 1812. In an implementation, if STA 1810 does not receive ACK frame 1824 from STA 1812, STA 1810 may assume that all data units of data frame 1823 were received in error by STA 1812.

[0184] Upon receiving ACK request frame 1825, relay 1811 may transmit an ACK frame 1826 to STA 1810. ACK frame1826 may comprise a positive acknowledgment or a negative acknowledgment. ACK frame 1826 may comprise a block acknowledgement frame. In an embodiment, ACK request frame 1825 may request that relay 1811 respond to ACK request frame 1825 by conveying the contents of ACK frame 1824 transmitted by STA 1812. As such, assuming that relay 1811 receives ACK frame 1824, relay 1811 may include in ACK frame 1826 the contents of ACK frame 1824 in addition to the reception status of relay 1811 for data frame 1823. That is, ACK frame 1826 may include the reception status of both STA 1812 and relay 1811 for data frame 1823.

[0185] Based on receiving ACK frame 1824 and ACK frame 1826 (or, in another embodiment, based on receiving ACK frame 1826 only), STA 1810 may compare reception status of the data units of data frame 1823 by STA 1812 and relay1811. Specifically, STA 1810 may determine if one or more data units of data frame 1823 were received in error by STA 1812 but successfully by relay 1811. If so, STA 1810 may transmit a trigger frame 1827 to relay 1811 to trigger transmission by relay 1811 to STA 1812 of those one or more data units. Trigger frame 1827 may indicate the one or more data units of frame 1823 to be transmitted by relay 1811 to STA 1812. Upon receiving trigger frame 1827, relay 1811 transmits a data frame 1828 which includes the one or more data units indicated in trigger frame 1827. Upon receiving data frame 1828, STA 1812 may transmit an ACK frame 1829 to relay 1811. ACK frame 1829 may comprise a positive acknowledgment or a negative acknowledgment. ACK frame 1829 may comprise a block acknowledgement frame.

[0186] FIG. 19 illustrates an example 1900 of an auxiliary relay procedure according to an embodiment. As shown in FIG. 19, example 1900 may include a STA 1910, a STA 1912, and a relay 1911. Relay 1911 may have a relay architecture as described above in FIG. 11. Alternatively, relay 1911 may be a STA (AP STA or non-AP STA) configured to perform relay functions. In example 1900, relay 1911 may be configured to relay traffic from STA 1910 to STA 1912.

[0187] In example 1900, STA 1910 may have first data for transmission to STA 1912. STA 1910 may wish or may be configured to transmit the first data to STA 1912 via relay 1911. STA 1910 may be further configured to protect the transmission of the first data to relay 1911 using an RTS / CTS procedure. It is further assumed in example 1900 that STA 1912 may be within the communication range of STA 1912.

[0188] As shown in FIG. 19, example 1900 begins with STA 1910 transmitting an MU-RTS trigger frame 1920 to relay 1911 and STA 1912. MU-RTS trigger frame 1920 triggers the transmission of CTS frame(s) from relay 1911 and STA 1912. Upon receiving MU-RTS frame 1820, with its NAV indicating idle, relay 1911 transmits a CTS frame 1921 to STA 1910. Similarly, STA 1912 transmits a CTS frame 1922 to STA 1912, based on its NAV indicating idle.

[0189] Upon receiving CTS frames 1921 1922, STA 1910 may transmit a data frame 1923 to both relay 1911 and STA 1912. In an embodiment, data frame 1923 may include an indication that both relay 1911 and STA 1912 shall decode the data contained in data frame 1923. In an embodiment, data frame 1923 may solicit an acknowledgement frame from both relay 1911 and STA 1912. In an implementation, data frame 1923 may comprise a first field for soliciting an acknowledgement from STA 1912. The first field may be provided in a physical layer (PHY) header of data frame 1923. In another implementation, the first field may be provided in a medium access control (MAC) header of a first MPDU of data frame 1923. In another embodiment, data frame 1923 may further comprise a second field to indicate that relay 1911 is an auxiliary relay. In an implementation, the second field may be provided in a PHY header of data frame 1923. In another implementation, the second field may be provided in a MAC header of the first MPDU of data frame 1923. In another embodiment, data frame 1923 may further comprise a third field for indicating a receiver address of data frame 1923. In an implementation, the receiver address is set to an address of relay 1911.

[0190] Upon receiving data frame 1923, STA 1912 may transmit an ACK frame 1924. ACK frame 1924 may comprise a positive acknowledgment or a negative acknowledgment. In an implementation, ACK frame 1924 may comprise a block acknowledgement frame, which indicates the reception status of data units contained in data frame 1923. The data units may be MPDUs.

[0191] Upon receiving ACK frame 1924, STA 1910 may check if all the data units of data frame 1923 were received correctly by STA 1912. If one or more data units were received in error, STA 1910 may transmit an ACK request frame1925 to relay 1911 to obtain the reception status of data units of data frame 1923 by relay 1911. In an implementation, ACK request frame 1925 requests the reception status at relay 1911 of all the data units of data frame 1923. In another implementation, ACK request frame 1925 requests the reception status at relay 1911 of only those data units received in errorby STA 1912. In an implementation, if STA 1710 does not receive ACK frame 1724 from STA 1712, STA 1710 may assume that all data units of data frame 1723 were received in error by STA 1712.

[0192] Upon receiving ACK request frame 1925, relay 1911 may transmit an ACK frame 1926 to STA 1910. ACK frame1926 may comprise a positive acknowledgment or a negative acknowledgment. ACK frame 1926 may comprise a block acknowledgement frame. In an implementation, ACK frame 1926 includes the reception status at relay 1911 of all the data units of data frame 1923. In another implementation, ACK frame 1926 includes the reception status at relay 1911 of only those data units received in error by STA 1912 as indicated by ACK request frame 1925.

[0193] In an embodiment, on receiving ACK frame 1924, relay 1911 may compare the reception status of the data units of data frame 1923 by STA 1912 with its own reception status of the same data units. Specifically, relay 1911 may determine if one or more data units of data frame 1923 that relay 1911 received successfully were received in error by STA 1912. If so, relay 1911 may transmit a data frame 1927 including those data units to STA 1912. Upon receiving data frame 1927, STA 1912 may transmit an ACK frame 1928 to relay 1911. ACK frame 1928 may comprise a positive acknowledgment or a negative acknowledgment. ACK frame 1928 may comprise a block acknowledgement frame.

[0194] Upon receiving ACK frame 1928, relay 1911 may transmit an ACK frame 1929 to STA 1910. ACK frame 1929 may comprise a positive acknowledgment or a negative acknowledgment. ACK frame 1929 may comprise a block acknowledgement frame. ACK frame 1929 may indicate the reception status of data frame 1923 by relay 1911. In another implementation, ACK frame 1924 may indicate the reception status at STA 1912 of the data units of data frame 1923 after the transmission of data frame 1927 by relay 1911 to STA 1912.

[0195] FIG. 20A illustrates an example 2000A of a frame which may be used in embodiments. Frame 2000A may be an embodiment of frame 1623, 1723, 1823, or 1923, for example. As such, frame 2000A may be used to transmit data to a destination STA and to solicit an acknowledgment from multiple STAs, including a destination STA (to which the data is intended) and a relay.

[0196] As shown in FIG. 20A, frame 2000A comprises a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), a repeated L-SIG (RL-SIG), a universal signal field (U-SIG), an Extremely High Throughput (EHT) signal field (EHT-SIG), an EHT short training field (EHT-STF), one or more EHT long training field (EHT-LTF), a data field, and a packet extension (PE) field.

[0197] The L-SIG, RL-SIG, U-SIG, and EHT-SIG form a PHY header of frame 2000A. In an embodiment, as described above, the PHY header may comprise a first field for soliciting an acknowledgement from the destination STA. In an implementation, as shown in FIG. 20A, the EHT-SIG may comprise a common info field and a user specific field. In another embodiment, the PHY header may further comprise a second field for indicating that the relay is to be operateas an auxiliary relay. As described above, when a relay is configured to operate as an auxiliary relay, it may perform relay functions in response to one or more conditions being true. In a further embodiment, the PHY header may further comprise a third field for indicating a receiver address of frame 2000A. In an implementation, the first field, second field, and / or third field may be provided in the user specific field of the EHT-SIG, each in a respective user field of the user specific field.

[0198] FIG. 20B illustrates an example 2000B of a frame which may be used in embodiments. Frame 2000B may be an embodiment of frame 1623, 1723, 1823, or 1923, for example. As such, frame 2000B may be used to transmit data to a destination STA and to solicit an acknowledgment from multiple STAs, including a destination STA (to which the data is intended) and a relay.

[0199] As shown in FIG. 20B, frame 2000B comprises a MAC header that comprises a plurality of address fields (Address 1, Address 2, and Address 3). In an embodiment, a receiver address (RA) and a destination address (DA) of frame 2000B may be provided in the plurality of address fields of frame 2000B. The RA may identify the relay. The DA may identify the destination STA. In another embodiment, there may be more than 3 address fields, including the address fields comprising the RA and DA. In a further embodiment, the MAC header of frame 2000B may comprise a first field for soliciting an acknowledgement from the destination STA indicated by the DA. In an embodiment, the MAC header may comprise a second field to indicate that relay is to operate as an auxiliary relay. The first field and / or the second field may be provided in an HT control field of the MAC header. As described above, when a relay is configured to operate as an auxiliary relay, it may perform relay functions in response to one or more conditions being true.

[0200] In a further embodiment, the MAC Header may further comprise a third field, for indicating a receiver address of frame 2000B.

[0201] FIG. 21 illustrates an example process 2100 according to an embodiment. Example process 2100 is provided for the purpose of illustration only and is not limiting embodiments. Process 2100 may be performed by a first STA (e.g., non-AP STA or AP STA) while communicating with a second STA (e.g., non-AP STA or AP STA) and a third STA (e.g., non-AP STA or AP STA). The first STA, the second STA and the third STA may be communicatively coupled by a link (e.g., 2.4 GHz, 5 GHz, 6 GHz, 60 GHz, etc.). The first STA may be a source STA, the second STA may be a relay, and the third STA may be a destination STA of a relay communication. As shown in FIG. 21, process 2100 includes steps 2102, 2104, 2106, and 2108.

[0202] As shown in FIG. 21, process 2100 begins in step 2102, which includes transmitting, by the first STA to the second STA and the third STA, a first frame comprising one or more data units. The first frame may comprise a PPDU. In an embodiment, the first frame may solicit a first acknowledgement frame from the second STA and a second acknowledgement frame from the third STA. In an embodiment, the first frame may comprise a first field for soliciting the first acknowledgement frame from the second STA. In an embodiment, the first field may be provided in a PHY header of the first frame. In an embodiment, the first field may be provided in a MAC header of a first MPDU of the first frame.

[0203] In an embodiment, the first frame may comprise a second field for configuring the second STA as an auxiliary relay for the first frame. In an embodiment the second field may be provided in a PHY header of the first frame. In an embodiment, the second field may be provided in a MAC header of a first MPDU of the first frame.

[0204] In an embodiment, the first frame further may comprise a third field for indicating a receiver address of the first frame. In an embodiment, the receiver address may be set to an address to the second STA.

[0205] Step 2104 may include receiving, by the first STA from the second STA, the first acknowledgement frame in response to the first frame. In an embodiment, the first acknowledgement frame may comprise a positive acknowledgment or a negative acknowledgment. In an embodiment, the first acknowledgement frame may comprise a block acknowledgement frame.

[0206] Step 2106 includes receiving, by the first STA from the third STA, the second acknowledgement frame in response to the first frame In an embodiment, the second acknowledgement frame may comprise a positive acknowledgment or a negative acknowledgment. In an embodiment, the second acknowledgement may comprise a block acknowledgement frame.

[0207] Step 2108 may include transmitting, by the first STA to the second STA, a second frame to trigger transmission, by the second STA to the third STA, of at least one of the one or more data units of the first frame, based on one or more of the first and second acknowledgement frames. In an embodiment, transmitting the second frame may comprise transmitting the second frame on condition that: the first acknowledgement frame comprises a positive acknowledgement for a first data unit of the one or more data units and the second acknowledgement frame comprises a negative acknowledgement for the first data unit. In an embodiment, where the second acknowledgment frame comprises a negative acknowledgment for the first data unit, step 2108 may include transmission of the first data unit.

[0208] FIG. 22 illustrates an example process 2200 according to an embodiment. Example process 2200 is provided for the purpose of illustration only and is not limiting embodiments. Process 2200 may be performed by a first STA (e.g., non-AP STA or AP STA) while communicating with a second STA (e.g., non-AP STA or AP STA) and a third STA (e.g., non-AP STA or AP STA). The first STA, the second STA and the third STA may be communicatively coupled by a link (e.g., 2.4 GHz, 5 GHz, 6 GHz, 60 GHz, etc.). The first STA may be a relay, the second STA may be a source STA, and the third STA may be a destination STA of a relay communication. As shown in FIG. 22 process 2200 includes steps 2202, 2204, and 2206.

[0209] As shown in FIG. 22, process 2200 begins in step 2202, which includes receiving, by the first STA from the second STA, a first frame soliciting a first acknowledgement frame from the first STA and a second acknowledgement frame from the third STA. The first frame comprises one or more data units. The first frame may comprise a PPDU. In an embodiment, the first frame may comprise a first field for soliciting the first acknowledgement frame from the first STA. In an embodiment, the first field may be provided in a PHY header of the first frame. In an embodiment, the first field may be provided in a MAC header of a first MPDU of the first frame. In an embodiment, the first frame may comprise a second field for configuring the first STA as an auxiliary relay for the first frame. In an embodiment, second field may be providedin a PHY header of the first frame. In an embodiment, the second field may be provided in a MAC header of a first MPDU of the first frame.

[0210] In an embodiment, the first STA may receive from the third STA, the second acknowledgment frame transmitted by the third STA in response to the first frame.

[0211] Step 2204 includes transmitting by the first STA to the second STA the first acknowledgement frame in response to the first frame. In an embodiment, the first acknowledgement may comprise a positive acknowledgment or a negative acknowledgment. In an embodiment, the first acknowledgement frame may comprise a block acknowledgement frame.

[0212] In an embodiment, after transmitting the first acknowledgement frame in step 2204, process 2200 may further comprise receiving by the first STA from the second STA, = a second frame to trigger transmission, by the first STA to the third STA, of the at least one of the one or more data units of the first frame.

[0213] Step 2206 includes transmitting, by the first STA to the third STA, may transmit to the third STA, at least one of the one or more data units of the first frame. In an embodiment, transmitting, by the first STA to the third STA, the at least one of the one or more data units of the first frame comprises transmitting the at least one of the one or more data units of the first frame based on the second acknowledgment frame. In an embodiment, transmitting, by the first STA to the third STA, the at least one of the one or more data units of the first frame comprises transmitting the at least one of the one or more data units of the first frame based on the second acknowledgment frame comprising a negative acknowledgment for a first data unit of the one or more data units of the first frame.

[0214] In an embodiment, the second acknowledgement frame may comprise a negative acknowledgement for the first data unit. Transmitting the at least one of the one or more data units comprises transmission of the first data unit.

Claims

CLAIMS1. A method comprising: transmitting, by a first station (STA) to a second STA and a third STA, a first frame soliciting a first acknowledgement frame from the second STA and a second acknowledgement frame from the third STA, wherein the first frame comprises one or more data units; receiving, by the first STA from the second STA, the first acknowledgement frame; receiving, by the first STA from the third STA, the second acknowledgement frame; and based on one or more of the first and second acknowledgement frames, transmitting, by the first STA to the second STA, a second frame to trigger transmission, by the second STA to the third STA, of at least one of the one or more data units of the first frame.

2. A method comprising: transmitting, by a first station (STA) to a second STA and a third STA, a first frame comprising one or more data units; receiving, by the first STA from the second STA, a first acknowledgement frame in response to the first frame; receiving, by the first STA from the third STA, a second acknowledgement frame in response to the first frame; and based on one or more of the first and second acknowledgement frames, transmitting, by the first STA to the second STA, a second frame to trigger transmission, by the second STA to the third STA, of at least one of the one or more data units of the first frame.

3. The method of claim 2, wherein the first frame solicits the first acknowledgement frame from the second STA and the second acknowledgement frame from the third STA.

4. The method of claim 3, wherein the first frame comprises a first field for soliciting the first acknowledgement frame from the second STA.

5. The method of claim 4, wherein the first field is provided in a physical layer (PHY) header of the first frame.

6. The method of claim 4, wherein the first field is provided in a medium access control (MAC) header of a first MPDU of the first frame.

7. The method of any of claims 2-6, wherein the first frame comprises a second field for configuring the second STA as an auxiliary relay for the first frame.

8. The method of claim 7, wherein the second field is provided in a physical layer (PHY) header of the first frame.

9. The method of claim 7, wherein the second field is provided in a medium access control (MAC) header of a first MPDU of the first frame.

10. The method of any of claims 2-9, wherein the first frame further comprises a third field, for indicating a receiver address of the first frame.

11. The method of claim 10, wherein the receiver address is set to an address to the second STA.

12. The method of any of claims 2-11, wherein the first acknowledgement frame comprises a positive acknowledgment or a negative acknowledgment.

13. The method of any of claims 2-12, wherein the second acknowledgement frame comprises a positive acknowledgment or a negative acknowledgment.

14. The method of any of claims 2-13, wherein the first acknowledgement frame comprises a block acknowledgement frame.

15. The method of any of claims 2-14, wherein the second acknowledgement frame comprises a block acknowledgement frame.

16. The method of any of claims 2-15, wherein the first frame comprises a PPDU.

17. The method of any of claims 2-16, wherein transmitting the second frame comprises transmitting the second frame on condition that:(i) the first acknowledgement frame comprises a positive acknowledgement for a first data unit of the one or more data units; and(ii) the second acknowledgement frame comprises a negative acknowledgement for the first data unit.

18. The method of claim 17, wherein the second acknowledgement frame comprises a negative acknowledgement for the first data unit and wherein, the transmission of at least one of the one or more data units comprises transmission of the first data unit.

19. A method comprising: receiving, by a first station (STA) from a second STA, a first frame soliciting a first acknowledgement frame from the first STA and a second acknowledgement frame from a third STA, wherein the first frame comprises one or more data units; transmitting, by the first STA to the second STA, the first acknowledgement frame; after transmitting the first acknowledgement frame, receiving, by the first STA from the second STA, a second frame to trigger transmission, by the first STA to the third STA, of one or more data units of the first frame; and transmitting, by the first STA to the third STA, of at least one of the one or more data units of the first frame.

20. A method comprising: receiving, by a first station (STA) from a second STA, a first frame soliciting a first acknowledgement frame from the first STA and a second acknowledgement frame from a third STA, wherein the first frame comprises one or more data units; transmitting, by the first STA to the second STA, the first acknowledgement frame in response to the first frame; and transmitting, by the first STA to the third STA, at least one of the one or more data units of the first frame.

21. The method of claim 20, further comprising, after transmitting the first acknowledgement frame, receiving, by the first STA from the second STA, a second frame to trigger transmission, by the first STA to the third STA, of the at least one of the one or more data units of the first frame.

22. The method of claim 20, further comprising receiving, by the first STA from the third STA, a second acknowledgment frame transmitted by the third STA in response to the first frame.

23. The method of claim 22, wherein transmitting, by the first STA to the third STA, the at least one of the one or more data units of the first frame comprises transmitting the at least one of the one or more data units of the first frame based on the second acknowledgment frame.

24. The method of claim 23, wherein transmitting, by the first STA to the third STA, the at least one of the one or more data units of the first frame comprises transmitting the at least one of the one or more data units of the first frame based on the second acknowledgment frame comprising a negative acknowledgment for a first data unit of the one or more data units of the first frame.

25. The method of claim 24, wherein the second acknowledgement frame comprises a negative acknowledgement for the first data unit and wherein, transmitting the at least one of the one or more data units comprises transmission of the first data unit.

26. The method of any of claims 21-25, wherein the first frame comprises a first field for soliciting the first acknowledgement frame from the first STA.

27. The method of claim 26, wherein the first field is provided in a physical layer (PHY) header of the first frame.

28. The method of claim 26, wherein the first field is provided in a medium access control (MAC) header of a first MPDU of the first frame.

29. The method of any of claims 20-28, wherein the first frame comprises a second field for configuring the first STA as an auxiliary relay for the first frame.

30. The method of claim 29, wherein the second field is provided in a physical layer (PHY) header of the first frame.

31. The method of claim 29, wherein the second field is provided in a medium access control (MAC) header of a first MPDU of the first frame.

32. The method of any of claims 20-31, wherein the first acknowledgement comprises a positive acknowledgment or a negative acknowledgment.

33. The method of any of claims 20-32, wherein the first acknowledgement frame comprises a block acknowledgement frame.

34. A device comprising: one or more processors; and memory storing instructions that, when executed by the one or more processors, cause the device to perform a method according to any of claims 1 -33.

35. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform a method according to any of claims 1-33.

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