Trigger based physical layer protocol data unit format for inter-access point communication

Abstract

A first access point (AP) transmits a frame comprising a first basic service set (BSS) color of a BSS of which the first AP is a member. The first AP receives, from a second AP, a trigger frame soliciting a first trigger based (TB) physical layer (PHY) protocol data unit (PPDU) from the first AP. The first AP transmits, to the second AP and in response to the trigger frame, the first TB PPDU, wherein based on the trigger frame further soliciting a second TB PPDU from a third AP, a BSS color field of the first TB PPDU comprises a second BSS color different than the first BSS color.

Description

Docket No.: 25-3003PCTTITLETrigger Based Physical Layer Protocol Data Unit Format for Inter-Access Point Communication CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 753,620 , filed February 4, 2025, and U.S. Provisional Application No. 63 / 804,891, filed May 13, 2025, which are hereby incorporated by reference in their entireties.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 a non-High Throughput (non-HT) Physical Layer Protocol Data Unit (PPDU), a High Throughput (HT) mixed PPDU, and a Very High Throughput (VHT) PPDU.

[0006] FIG. 4 illustrates a High Efficiency (HE) Single User (SU) PPDU, an HE Multi-User (MU) PPDU, and an HE Extended Range (ER) SU PPDU.

[0007] FIG. 5 illustrates an Extremely High Throughput (EHT) Multi-user (MU) PPDU.

[0008] FIG. 6 illustrates an Ultra-High Reliability (UHR) Multi-user (MU) PPDU.

[0009] FIG.7 illustrates an example Universal Signal field (U-SIG) which may be used in EHT Trigger Based (TB) PPDUs

[0010] FIG. 8 illustrates an example Universal Signal (U-SIG) field which may be used in UHR MU PPDUs.

[0011] FIG. 9 illustrates an example control frame which may be used as a trigger frame.

[0012] FIG. 10 shows an example that illustrates use of a trigger based (TB) PPDU.

[0013] FIG. 11 illustrates an example that illustrates inter-AP communication.

[0014] FIG. 12 illustrates an example that highlights a potential problem that may arise in inter-AP communication.

[0015] FIG. 13 illustrates an example operation according to an embodiment.

[0016] FIG. 14 illustrates a further example operation according to an embodiment.

[0017] FIG. 15 illustrates an additional example operation according to an embodiment.

[0018] FIG. 16 illustrates another example operation according to an embodiment.

[0019] FIG. 17 illustrates another example operation according to an embodiment.

[0020] FIG. 18 illustrates an example process according to an embodiment.

[0021] FIG. 19 illustrates another example process according to an embodiment.Docket No.: 25-3003PCTDETAILED DESCRIPTION

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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 {STA1 , STA2}. The phrase “based on” (or equally “based at least on”) isDocket No.: 25-3003PCTindicative 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, or may 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 “employing / using” (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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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 combinationDocket No.: 25-3003PCTthereof, 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 LabVIEW MathScript. 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.

[0030] FIG. 1 illustrates example wireless communication network 100 in which embodiments of the present disclosure may be implemented. 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.

[0031] 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.

[0032] 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).

[0033] 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.

[0034] The example wireless communication networks illustrated in FIG. 1 may further include one or more ad-hoc networks or independent BSSs (IBSSs). An ad-hoc network or IBSS 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 (e.g., not via an AP).

[0035] 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 doesDocket No.: 25-3003PCTnot 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.

[0036] 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.

[0037] 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 (PLCP) 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.

[0038] A frequency band may include one or more sub-bands or frequency channels. For example, PPDUs conforming to the IEEE 802.11n, 802.11ac, 802.11ax and / or 802.11be 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.

[0039] FIG. 2 is a block diagram 200 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.

[0040] 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 moreDocket No.: 25-3003PCTcontrollers 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.

[0041] 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.

[0042] T ransceiver 240 / 290 may be configured to transmit / receive radio signals. In an example, transceiver 240 / 290 may implement a PHY layer of the corresponding device (STA 210 or AP 260). In an example, 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 by the 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.

[0043] FIG. 3 illustrates a non-High Throughput (non-HT) PPDU 310, a High Throughput (HT) mixed mode PPDU 320, and a Very High Throughput (VHT) PPDU 330.

[0044] Non-HT PPDU 310 may be used by STAs conforming to the IEEE 802.11a standard amendment. As shown in FIG. 3, non-HT PPDU 310 includes a non-HT Short Training field (L-STF), a non-HT Long Training field (L-LTF), a non-HT Signal field (L-SIG), and a Data field. The L-STF, L-LTF, and L-SIG form a 20 pis preamble of non-HT PPDU 310.

[0045] The L-STF may be used by a receiver of non-HT PPDU 310 to synchronize with the carrier frequency and frame timing of a transmitter of non-HT PPDU 310 and to adjust the receiver signal gain. The L-LTF may be used by the receiver of non-HT PPDU 310 to estimate channel coefficients in order to equalize the channel response (e.g., amplitude and phase distortion) in both the L-SIG and the Data fields of non-HT PPDU 310.

[0046] The L-SIG contains parameters needed to demodulate the Data field, which contains a payload of non-HT PPDU 310. The L-SIG may be equalized using the channel coefficients estimated using the L-LTF and demodulated to obtain the demodulation parameters of the Data field. The Data Field includes one or more symbols each having a duration of 4 pis, where 3.2 pis carry symbol information and 0.8 pis carry a Guard Interval (Gl)

[0047] For non-HT PPDUs, the only supported bandwidth is 20MHz, which is divided into 64 subcarriers. As such, non-HT PPDU 310 may be encoded using a subcarrier spacing of 20MHz / 64 or 312.5kHz.

[0048] HT mixed mode PPDU 320 may be used by STAs conforming to the IEEE 802.11n standard amendment. HT mixed mode PPDU 320 can support MIMO to up to 4 spatial streams, which enhancesDocket No.: 25-3003PCTspectral efficiency four folds. HT mixed mode PPDU 320 has a minimum preamble duration of 35.6 pis, which may increase depending on the number of spatial streams carried by the PPDU.

[0049] As shown in FIG. 3, HT mixed mode PPDU 320 includes an L-STF, an L-LTF, an L-SIG, an HT Signal field (HT-SIG) field, an HT Short Training field (HT-STF) field, one or more HT Long Training field (HT-LTF), and a data field. The HT-LTF and data fields include of one or more symbols each having a duration of 3.6 pis or 4 pis. In both cases, 3.2 pis carry symbol information while the remaining 0.4 pis or 0.8 pis carry a Gl. The 0.4 pis long Gl is called short Gl while the 0.8 pis long Gl is called regular or normal Gl.

[0050] For HT mixed mode PPDUs, two bandwidths, 20 MHz and 140 MHz, may be supported. When the PPDU bandwidth is 20MHz, the band is divided into 64 subcarriers. When the PPDU bandwidth is 140 MHz, the band is divided into 128 subcarriers. In both cases, subcarrier spacing of 312.5 kHz is maintained.

[0051] VHT PPDU 330 may be used by STAs conforming to the IEEE 802.11ac standard amendment. VHT PPDU 330 can support MIMO transmission to up to 8 spatial streams, which enhances spectral efficiency eight folds. VHT PPDU 330 has a minimum preamble duration of 39.6 pis, which may increase depending on the number of spatial streams carried by VHT PPDU 330.

[0052] As shown in FIG. 3, VHT PPDU 330 includes an L-STF, an L-LTF, an L-SIG, a VHT Signal A field (VHT-SIG-A), a VHT Short Training field (VHT-STF), one or more VHT Long Training field (VHT-LTF), a VHT Signal B field (VHT-SIG-B), and a Data field. The VHT-LTF and Data fields of VHT PPDU 330 include one or more symbols each having a duration of 3.6 pis or 4 pis. In both cases, 3.2 pis carry symbol information while the remaining 0.4 pis or 0.8 pis carry of the Gl. The 0.4 pis long Gl is called the Short Gl while the 0.8pis long is called regular or normal Gl.

[0053] For VHT PPDUs, four bandwidths, 20 MHz, 40 MHz, 80 MHz, and 160 MHz, may be supported. When the PPDU bandwidth is 20MHz, the band is divided into 64 subcarriers. When the PPDU bandwidth is 40 MHz, the band is divided into 128 subcarriers. When the PPDU bandwidth is 80MHz, the band is divided into 256 subcarriers. When the PPDU bandwidth is 160 MHz, the band is divided into two 256-subcarrier 80MHz bands. In all cases, a subcarrier spacing of 312.5 kHz is maintained.

[0054] FIG. 4 illustrates a High Efficiency (HE) Single User (SU) PPDU 410, an HE Multi-User (MU) PPDU 420, and an HE Extended Range (ER) SU PPDU 430. HE SU PPDU 410, HE MU PPDU 420, and HE ER SU PPDU 430 may be used by STAs conforming to the IEEE 802.11ax standard amendment.

[0055] HE SU PPDU 410 supports higher spectral efficiency compared to VHT PPDU 330 due to increased subcarrier spacing and higherorder modulation support. HE SU PPDU 410 has a minimum preamble duration of 44 pis.

[0056] As shown in FIG. 4, HE SU PPDU 410 includes an L-STF, an L-LTF, an L-SIG, a Repeated L-SIG (RL-SIG), an HE Signal A field (HE-SIG-A), an HE Short Training field (HE-STF) field, one or more HE Long Training field (HE-LTF), a Data field, and a PE field.Docket No.: 25-3003PCT

[0057] Similar to HE SU PPDU 410, HE MU PPDU 420 supports higher spectral efficiency compared to VHT PPDU 330. HE MU PPDU 420 also supports OFDMA. Due to denser subcarrier spacing (as in HE SU PPDU 410), HE MU PPDU 420 allows for payloads of multiple users to be multiplexed in the frequency domain in the Data field. HE MU PPDU 420 supports multiplexing the payload of up to 9 users in a single 20 MHz band. HE MU PPDU 420 has a minimum preamble duration of 47.2 pis, which may increase depending on the number of spatial streams carried by HE MU PPDU 420.

[0058] As shown in FIG. 4, HE MU PPDU 420 includes an L-STF, an L-LTF, an L-SIG, an RL-SIG, an HE-SIG-A, an HE Signal B Field (HE-SIG-B), an HE-STF field, one or more HE-LTF field, a Data field, and a PE field. It is noted that compared to HE SU PPDU 410, HE MU PPDU 420 further includes HE-SIG-B. HE-SIG-B contains indications per STA of RU allocations. A STA may use the indications in HE-SIG-B to locate its payload in HE MU PPDU 420.

[0059] For HE SU PPDU 410 and HE MU PPDU 420, the Gl portion of the HE-LTF and Data field may be one of one of 0.8 pis, 1.6 pis, and 3.2 pis. An AP or STA may use a suitable Gl duration depending on the channel conditions or capability of the target STA or AP.

[0060] For both HE SU PPDU 410 and HE MU PPDU 420, the information portion of the HE-LTF may be one of 3.2 pis, 6.4 pis, or 12.8 pis. Depending on the information portion duration, a subcarrier spacing of the HE-LTF may be one of: 312.5kHz if the information potion is 3.2 pis, 156.25kHz if the information portion is 6.4 pis, and 78.125kHz if the information portion is 12.8 pis. Unlike the HE-LTF, the information portion of the Data field for both HE SU PPDU 410 and HE MU PPDU 420 is always 12.8 pis. Hence, a subcarrier spacing of the Data field is always 78.125kHz corresponding to the duration of the information portion being 12.8 pis. When a 3.2 pis or 6.4 pis long HE-LTF is used by a transmitting STA to transmit HE SU PPDU 410 or HE MU PPDU 420, a receiving STA is required to interpolate the channel estimates to a subcarrier spacing resolution of 78.125kHz to match the subcarrier spacing of the Data field.

[0061] As shown in FIG. 4, HE ER SU PPDU 430 includes an L-STF, an L-LTF, an L-SIG, an RL-SIG, an HE-SIG-A, an HE-STF, one or more HE-LTF, a Data field, and a PE field. It is noted that compared to HE SU PPDU 410, HE ER SU PPDU 430 has an HE-SIG-A that is duplicated in the time domain (16 pis long instead of 8 pis long in HE SU PPDU 410). As such, both L-SIG (duplicated using RL-SIG) and HE-SIG-A are sent in duplicates, which allows a receiving STA to combine the two copies to increase the energy of the received signal. This results in an extended range of reception and increases transmission reliability between the transmitting STA and the receiving STA.

[0062] FIG. 5 illustrates an Extremely High Throughput (EHT) MU PPDU. EHT MU PPDU 510 supports OFDMA up to a bandwidth of 320MHz. EHT MU PPDU 510 can improve spectral efficiency due to support of a higher order modulation compared to other PPDUs (e.g., HE SU PPDU 410 and HE MU PPDU 420) while supporting the same number of spatial streams. EHT MU PPDU 510 has a minimum preamble duration of 47.2 pis, which may increase depending on the number of spatial streams carried by EHT MU PPDU 510.Docket No.: 25-3003PCT

[0063] As shown in FIG. 5, EHT MU PPDU 510 includes an L-STF, an L-LTF, an L-SIG, an RL-SIG, a Universal Signal field (U-SIG), an EHT Signal field (EHT-SIG), an EHT Short Training Field (EHT-STF), one or more EHT Long Training fields (EHT-LTF), a Data field, and a PE field It is noted that according to the IEEE 802.11 be standard amendment, EHT MU PPDU 510 may be used by a transmitting STA for both SU and MU transmissions.

[0064] The U-SIG is intended to ensure forward compatibility of EHT MU PPDU 510. This means that any future PPDUs that are backward compatible to IEEE 802.11 be will contain the same U-SIG field and interpretation. Because of this, IEEE 802.11be STAs will be able to understand at least in part a PPDU developed in a future amendment.

[0065] The EHT-SIG contains indications per STA of resource unit (RU) allocations. A STA may use the indications in the EHT-SIG to locate its payload in EHT MU PPDU 510.

[0066] The Gl portion of the EHT-LTF and Data fields of EHT MU PPDU 510 may be one of: 0.8 s, 1.6 ps, or 3.2 ps. An AP or STA may use a suitable Gl duration depending on the channel conditions or capability of the target STA or AP.

[0067] The information portion of the EHT-LTF may be one of 3.2 ps, 6.4 ps, or 12.8 ps. Depending on the information portion duration, a subcarrier spacing of the EHT-LTF may be one of: 312.5kHz if the information potion is 3.2 ps, 156.25kHz if the information portion is 6.4 ps, or 78.125kHz if the information portion is 12.8 ps. The information portion of the Data field of EHT MU PPDU 510 is always 12.8 ps. Hence, a subcarrier spacing of the Data field is always 78.125kHz corresponding to the duration of the information portion being 12.8 ps. When a 3.2 ps long or a 6.4 ps long EHT-LTF is used by a transmitting STA to transmit EHT MU PPDU 510, a receiving STA is required to interpolate the channel estimates to a subcarrier spacing resolution of 78.125kHz to match the Data field subcarrier spacing.

[0068] FIG. 6 illustrates an Ultra-High Reliability (UHR) Multi-user (MU) PPDU. In an example, UHR MU PPDU 610 shares many similarities with EHT MU PPDU 510 illustrated in FIG. 5. For example, UHR MU PPDU 610 supports OFDMA up to a bandwidth of 320MHz, can improve spectral efficiency due to support of a higher order modulation compared to other PPDUs (e.g., HE SU PPDU 410 and HE MU PPDU 420) while supporting the same number of spatial streams, and has a minimum preamble duration of 47.2 pis, which may increase depending on the number of spatial streams carried by UHR MU PPDU 610.

[0069] Further, as shown in FIG. 6, and again like EHT MU PPDU 510 illustrated in FIG. 5, UHR MU PPDU 610 includes an L-STF, an L-LTF, an L-SIG, an RL-SIG, and a U-SIG field. In a example, UHR MU PPDU 610 includes a UHR Signal field (UHR -SIG), a UHR Short Training Field (UHR -STF), one or more UHR Long Training fields (UHR -LTF), a Data field, and a PE field. In an example, UHR MU PPDU 610 may be used by a transmitting STA for both SU and MU transmissions.

[0070] The U-SIG is intended to ensure forward and backward compatibility of UHR MU PPDU 610. This means that any future PPDUs that are backward compatible to IEEE 802.11 bn will contain the same U-SIGDocket No.: 25-3003PCTfield and interpretation. Because of this, IEEE 802.11bn STAs will be able to understand at least in part a PPDU developed in a future amendment. Likewise, STAs developed prior to IEEE 802.11bn that are capable of transmitting and receiving PPDUs (e.g., EHT MU PPDUs) with a U-SIG field will be able to understand at least in part a UHR MU PPDU.

[0071] The UHR-SIG contains indications per STA of RU allocations. A STA may use the indications in the UHR-SIG to locate its payload in UHR MU PPDU 610.

[0072] FIG. 7 illustrates an example U-SIG field 700 which may be used in EHT TB PPDUs. As shown in FIG. 7, U-SIG field 700 includes two symbols, U-SIG- 1 and U-SIG-2, each containing 26 bits.

[0073] U-SIG field 700 is designed to bring forward compatibility to the EHT preamble via the introduction of version independent subfields. For the EHT PHY, version independent subfields are located in U-SIG- 1 only. Version independent subfields are subfields that are consistent in location and interpretation across various IEEE 802.11 PHY layers. The intent of version independent subfields is to achieve better coexistence among IEEE 802.11 PHYs that are defined for 2.4, 5, and 6 GHz spectrum from the EHT PHY specification onwards.

[0074] As shown in FIG. 7, U-SIG field 700 includes version independent subfields followed by version dependent subfields. The version independent subfields are located from bit B0 to B19 of U-SIG- 1 , while the version dependent subfields are located from bits B20 to B25 of U-SIG- 1 and over all the bits of U-SIG-2.

[0075] The PHY Version Identifier subfield is one of the version independent subfields in U-SIG field 700. The purpose of the PHY Version Identifier is to facilitate autodetection for IEEE 802.11 PHY layers that are defined for 2.4, 5, and 6 GHz spectrum from the EHT PHY specification onwards. The value of this subfield is used to identify the exact PHY version of the EHT PPDU.

[0076] Other version independent subfields include a Bandwidth (BW) subfield, which indicates the PPDU bandwidth, an Uplink / Downlink (UL / DL) subfield, which indicates whether the PPDU is an uplink or a downlink PPDU, a BSS Color subfield, which indicates the BSS Color of the PPDU, and a TXOP subfield, which indicates a duration of a transmit opportunity (TXOP) in which the PPDU is transmitted.

[0077] Version dependent subfields in U-SIG field 700 are subfields specific to an IEEE 802.11 PHY. For example, in FIG. 7, the version dependent subfields include a Disregard subfield in U-SIG- 1 and all the subfields in U-SIG-2. As shown in FIG. 7, U-SIG-2 may include a PPDU Type and Compressed Mode subfield, a Validate subfield, a Spatial Reuse 1 subfield, a Spatial Reuse 2 subfield, a Disregard subfield, a CRC subfield, and a Tail subfield.

[0078] Disregard subfields (e.g., bits B20 to B25 of U-SIG-1 and bits B11 to B15 of U-SIG-2) are intended for use by a future PHY Version that may not be supported by a receiving STA. A Receiving STA may ignore these subfields without impact on the STA’s continued reception of the PPDU (i.e. , reception at the STA can continue as usual after skipping these fields).Docket No.: 25-3003PCT

[0079] The PPDU Type and Compressed Mode subfield indicates the type of PPDU among a number of PPDU types (e.g., EHT MU PPDU or EHT TB PPDU) supported by a particular PHY Version.

[0080] Validate subfields such as bit B2 in U-SIG-2 may indicate whether to continue or terminate the reception of a PPDU at a STA. If a STA encounters a PPDU where at least one field in the preamble that is identified as Validate for the STA is not set to the value specified for the field in that PHY version, the STA may terminate the reception of the PPDU. In this case, it waits until the PPDU’s estimated duration expires and report the information from the version independent subfields to the MAC layer. Similarly, the STA may terminate the reception of the PPDU when at least one field in the preamble equals a value that is identified as Validate for the STA.

[0081] Spatial Reuse subfields 1 and 2 may contain parameters to support spatial reuse features defined in a specific PHY version. Since these are version dependent subfields, only STAs supporting a specific PHY version are able to understand these bits.

[0082] The CRC subfield contains a frame check sum to validate the correctness of U-SIG field contents. The Tail subfield is set to 0 and is used to terminate the trellis of a convolutional encoder used to encode U-SIG fields.

[0083] FIG. 8 illustrates an example Universal Signal (U-SIG) field 800 which may be used in UHR MU PPDUs. As shown in FIG. 8, U-SIG field 800 includes two symbols, U-SIG- 1 and U-SIG-2, each containing 26 bits. In an example, like U-SIG field 700 illustrated in FIG. 5 for EHT MU PPDUs, U-SIG field 800 includes version independent subfields followed by version dependent subfields. The version independent subfields are located from bit B0 to B19 of U-SIG- 1 , while the version dependent subfields are located from bits B20 to B25 of U-SIG-1 and over all the bits of U-SIG-2.

[0084] The PHY Version Identifier subfield is one of the version independent subfields in U-SIG field 800. The purpose of the PHY Version Identifier is to facilitate autodetection for IEEE 802.11 PHY layers that are defined for 2.4, 5, and 6 GHz spectrum from the EHT PHY specification onwards. The value of this subfield is used to identify the exact PHY version of the PPDU. For example, the PHY Version Identifier may be set to 1 to indicate UHR (e.g., as opposed to 0 to indicate EHT).

[0085] Other version independent subfields include a Bandwidth (BW) subfield, which indicates the PPDU bandwidth, an Uplink / Downlink (UL / DL) subfield, which indicates whether the PPDU is an uplink or a downlink PPDU, a first BSS Color subfield, which indicates the BSS Color of the PPDU, and a TXOP subfield, which indicates a duration of a transmit opportunity (TXOP) in which the PPDU is transmitted.

[0086] Version dependent subfields in U-SIG field 800 are subfields specific to an IEEE 802.11 PHY. For example, in FIG. 8, the version dependent subfields include bits B20-B25. In an example, UHR may define a variant UHR MU PPDU for coordinated beamforming (Co-BF) and coordinated spatial reuse (Co-SR). In this case, a second BSS Color field may be defined to signal the BSS Color of a shared AP. The second BSS color may be used by the recipient STA of the Co-BF / Co-SR to decode their respective payloads. Where CoDocket No.: 25-3003PCTBF or Co-SR is used, bits B20-B25 may indicate this second BSS color. Where neither Co-BF nor Co-SR is used, bits B20-B25 may use the same definition as U-SIG field 700 for an EHT MU PPDU (e.g., bits B20-B24 may be disregard bits and bit B25 may be a validate bit).

[0087] As shown in FIG. 8, the U-SIG-2 may include a PPDU Type and Compression Mode field, similar to U-SIG field 700 illustrated in FIG. 7. Further, U-SIG-2 may include a Co-BF / Co-SR indication field. In an example, the Co-BF / Co-SR indication field indicates whether Co-SR is on, or off, in SU transmission, indicates whether Co-BF is on, or off, in non-OFDMA MU-MIMO, and is a validate bit in other cases. For example, a receiving STA may use the Co-BF / Co-SR indication field to identify whether B20-B25 in U-SIG-1 indicates a second BSS color. Where the Co-BF / Co-SR indication field is high, the receiving STA can identify the second BSS color for Co-BF / Co-SR using B20-B25 in U-SIG- 1.

[0088] In an example, the U-SIG-2 may further include a punctured channel information field, a validate bit, a UHR-SIG MCS field, a CRC field, and a tail field. The punctured channel information field may include a puncturing pattern indicating that the PPDU avoids transmissions in certain subcarriers. The validate field may be set to 1 and may be treated as a validate field. This means that a UHR STA may be configured not to continue reception of a UHR MU PPDU if the validate field indicates a value of 0. The UHR-SIG MCS field may indicate the MCS used for modulation of the UHR-SIG field of the UHR MU PPDU. The CRC field may contain a frame check sum to validate the correctness of U-SIG field contents. The tail subfield may be set to 0 and may be used to terminate the trellis of a convolutional encoder used to encode U-SIG fields.

[0089] FIG. 9 illustrates an example control frame which may be used as a trigger frame (TF) 900. Trigger frame 900 may be used by an AP to allocate resources for and solicit one or more TB PPDU transmissions from one or more STAs. Trigger frame 900 may also carry other information required by a responding STA to transmit a TB PPDU to the AP.

[0090] As shown in FIG. 9, trigger frame 900 includes a Frame Control field, a Duration field, a receiver address (RA) field, a transmitter address (TA) field, a Common Info field, a User Info List field, a Padding field, and an FCS field.

[0091] 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.

[0092] The Duration field indicates various contents depending on 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 field carries an association identifier (AID) of the STA that transmitted the frame in the 14 least significant bits (LSB), and the 2 most significant bits (MSB) are both set to 1. In other frames sent by STAs, the Duration field contains a duration value (in microseconds) which is used by a recipient to update a network allocation vector (NAV).

[0093] The RA field is the address of the STA that is intended to receive the incoming transmission from the transmitting station. The TA field is the address of the STA transmitting trigger frame 900 if trigger frameDocket No.: 25-3003PCT900 is addressed to STAs that belong to a single BSS. The TA field is the transmitted BSSID if trigger frame 900 is addressed to STAs from at least two different BSSs of the multiple BSSID set.

[0094] The Common Info field specifies a trigger frame type of trigger frame 900, a transmit power of trigger frame 900 in dBm, and several key parameters of a TB PPDU that is transmitted by a STA in response to trigger frame 900. The trigger frame type of a trigger frame used by an AP to receive QoS data using UL MU operation is referred to as a basic trigger frame. A non-EHT non-AP HE STA interprets the Common Info field as HE variant. A non-AP EHT STA interprets the Common Info field as HE variant if B54 and B55 in the Common Info field are equal to 1 ; and interprets the Common Info field as EHT variant otherwise. The HE variant Common Info field and the EHT variant Common Info field use the same encoding method for the Trigger Type, UL Length, More TF, CS Required, LDPC Extra Symbol Segment, AP TX Power, Pre-FEC Padding Factor, PE Disambiguity, and Trigger Dependent Common Info subfields.

[0095] The User Info List field contains zero or more User Info fields. There are three variants for the User Info field, which are the Special User Info field, the EHT variant User Info field, and the HE variant User Info field.

[0096] The Special User Info field is a User Info field that does not carry the user specific information but carries the extended common information not provided in the Common Info field. If the Special User Info field is included in the Trigger frame, then the Special User Info Field Flag subfield of the EHT variant Common Info field is set to 0, otherwise it is set to 1 . The Special User Info field is identified by an AID12 value of 2007 and is optionally present in a Trigger frame that is generated by an EHT AP. The Special User Info field, if present, is located immediately after the Common Info field of the Trigger frame and carries information for the U-SIG field of a solicited EHT TB PPDU. The PHY Version Identifier subfield indicates the PHY version of the solicited TB PPDU that is not an HE TB PPDU. The PHY Version Identifier subfield is set to 0 for EHT. Other values from 1 to 7 are reserved. The UL Bandwidth (BW) Extension subfield, together with the UL BW subfield in the Common Info field, indicates the bandwidth of the solicited TB PPDU from the addressed EHT STA (i.e., the bandwidth in the U-SIG field of the EHT TB PPDU). The EHT Spatial Reuse n subfield carries the values to be included in the corresponding Spatial Reuse n subfield in the U-SIG field of the EHT TB PPDU. The U-SIG Disregard And Validate subfield carries the values to be included in the Disregard and Validate subfields of the U-SIG field of the solicited EHT TB PPDUs. The presence and length of the Trigger Dependent User Info subfield in the Special User Info field depends on the variant of the Trigger frame.

[0097] The EHT variant User Info field contains a User Info field per STA addressed in trigger frame 900. The per STA User Info field includes, among others, an AID12 subfield, an RU Allocation subfield, a UL FEC Coding Type subfield, a UL extremely high throughput (EHT) modulation and coding scheme (MCS) (EHT-MCS) subfield, a Reserved subfield, a Spatial Stream (SS) Allocation / RA-RU information subfield, a UL Target Receive Power subfield, and a Power Save (PS) 160 subfield to be used by a STA in a TB PPDU transmitted in response to trigger frame 900, and a Trigger Dependent User Info subfield. The RU AllocationDocket No.: 25-3003PCTsubfield in an EHT variant User Info field in a Trigger frame that is not an MU-RTS Trigger frame, along with the UL BW subfield in the Common Info field, the UL BW Extension subfield in the Special User Info field, and the PS160 subfield in the EHT variant User Info field, identifies the size and the location of the RU or MRU. The values of PS160 subfield and BO of RU Allocation subfield indicate the 80 MHz frequency subblock in which the RU or MRU is located for 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, 484-tone RU, 996-tone RU, 52+26-tone RU, and 106+26-tone RU. The values of PS160 subfield indicates the 160 MHz segment in which the RU or MRU is located for 2996-tone RU, 996+484-tone MRU, and 996+484+242-tone MRU. The UL PEC Coding Type subfield of the User Info field indicates the code type of the solicited EHT TB PPDU. The UL PEC Coding Type subfield is set to 0 to indicate BCC and set to 1 to indicate LDPC. The UL EHT-MCS subfield of the User Info field indicates the EHT-MCS of the solicited EHT TB PPDU. The SS Allocation subfield of the EHT variant User Info field indicates the spatial streams of the solicited EHT TB PPDU. The UL Target Receive Power subfield indicates the expected receive signal power, measured at the AP's antenna connector and averaged over the antennas, for the EHT portion of the EHT TB PPDU transmitted on the assigned RU. The Trigger Dependent User Info subfield can be used by an AP to specify a preferred access category (AC) per STA. The preferred AC sets the minimum priority AC traffic that can be sent by a participating STA. The AP determines the list of participating STAs, along with the BW, MCS, RU allocation, SS allocation, Tx power, preferred AC, and maximum duration of the TB PPDU per participating STA. The RA-RU Information subfield is reserved in the EHT variant User Info field.

[0098] The Padding field is optionally present to extend the frame length to give recipient STAs enough time to prepare a response for transmission one SIFS after the frame is received. The Padding field, if present, is at least two octets in length and is set to all 1s.

[0099] The FCS field is used by a STA to validate a received frame and to interpret certain fields from the MAC headers of a frame.

[0100] FIG. 10 shows an example 1000 that illustrates use of a TB PPDU.

[0101] As shown in FIG. 10, example 1000 includes an AP 1002 and a plurality of STAs 1004-1 to 1004-8. In an example, AP 1002 may transmit trigger frame (TF) 1010 to STAs 1004-1 to 1004-8 to solicit UL frames from STAs 1004-1 to 1004-8. STAs 1004-1 to 1004-8 may respond simultaneously to TF 1010 by each transmitting a TB PPDU 1020. In an example, TB PPDU 1020 may have an 80 MHz bandwidth. As shown in FIG. 10, a STA 1004-1 to 1004-8 may duplicate four times over frequency each of the fields L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-STF to fill out the 80 MHz bandwidth. EHT-LTFs 1040-1 to 1040-8 and a data field 1050 of PPDU 1020 may fill out the entire 80 MHz bandwidth and are not duplicated over frequency. The number of EHT-LTFs transmitted by the STA (in time) is based on the maximum number of spatial streams across all RUs contained in the TB PPDU 1020. In example 1000, TB PPDU 1020 includes eight EHT-LTFs 1040-1 to 1040-8. AP 1002 may acknowledge TB PPDU 1020 by transmitting a multi-user block acknowledgment frame M-BA 1030.Docket No.: 25-3003PCT

[0102] As TB PPDUs 1020 transmitted by STAs 1004-1 to 1004-8 are transmitted simultaneously in response to TF 1010, precorrection of time, frequency, sampling clock, and power (in the case of a High Efficiency (HE) TB PPDU or extremely high throughput (EHT) TB PPDU) by STAs 1004-1 to 1004-8 may be necessary to mitigate synchronization and interference issues at AP 1002. Specifically, frequency and sampling clock precorrections are needed to prevent inter-carrier interference. Power precorrection is necessary to control interference between TB PPDUs 1020.

[0103] In an implementation, TF 1010 includes in a User Info field an uplink (UL) Target Receive Power subfield that indicates whether a STA among STAs 1004-1 to 1004-8 is to transmit TB PPDU 1020 at a maximum transmit power. The maximum transmit power may correspond to the STA's maximum transmit power for the assigned HE-MCS. The STA transmits TB PPDU 1020 at the maximum transmit power when the UL Target Receive Power subfield indicates that the maximum transmit power is to be used. Otherwise, the STA calculates the transmit power, T p™, of TB PPDU 1020 for the assigned HE-MCS using the equation:where PLDLis the downlink pathloss and TargetRxpwris the expected receive signal power, in units of dBm, as indicated by the UL Target Receive Power subfield in the User Info field of TF 1010. If the STA applies beamforming to TB PPDU 1020, the STA may take into account the beamforming gain when calculating the transmit power.

[0104] In an implementation, the STA computes PLDLusing the equation:where Txp ris the AP's transmit power, in units of dBm / 20 MHz, as indicated by an AP Tx Power subfield of a Common Info field of TF 1010 and Rxpwris the receive signal power, in units of dBm / 20MHz, of TF 1010 at an antenna connector of the STA. Rxpwrmay be an average of the receive signal power over the antennas on which the average PLDLis being computed.

[0105] FIG. 11 illustrates an example that illustrates inter-AP communication.

[0106] Example 1100 includes APs 1102 and 1104. In an example, APs 1102 and 1104 operate according to the IEEE 802.11 bn standard amendment and may be referred to as UHR APs. AP 1102 and AP 1104 may undertake inter-AP coordination for a variety of UHR features, including Co-BF, Co-SR, coordinated restricted target wake time (r-TWT) operation, and seamless roaming. This inter-AP coordination may require AP 1102 and AP 1104 to exchange management frames (e.g., an r-TWT schedule, a buffer status report (BSR), and other suitable management frames). For example, AP 1102 may solicit and receive feedback from AP 1104. AP 1102 may also provide unsolicited feedback to AP 1104.

[0107] An AP may select a BSS color value, and may include the BSS color value in a PPDU, to assist a STA receiving the PPDU in identifying the BSS from which the PPDU originates. As illustrated, AP 1102 andDocket No.: 25-3003PCTAP 1104 set their BSS colors to 1 and 2, respectively. In an example, the BSS color value set by each AP may be referred to as the BSS color that matches the color of the BSS of which the AP is a member. Each of AP 1102 and AP 1104 may then indicate their respective BSS color in an operation element (e.g., an HE operation element) included in transmitted management frame (e.g., a beacon, association response, or probe response). In addition, each of AP 1102 and AP 1104 may set the TXVECTOR parameter BSS_COLOR of HE PPDUs (e.g., HE SU PPDU 410, HE MU PPDU 420 and HE ER SU PPDU 430 illustrated in FIG. 4) or EHT MU PPDUs to match their respective BSS color value (e.g., to 1 or 2). For a non-AP STA associated with either AP 1102 or AP 1104 (not shown in FIG. 11), the STA may set the TXVECTOR parameter BSS_COLOR of an HE PPDU or EHT MU PPDU, that the non-AP STA transmits, to the value indicated in an operation element received from its associated AP (e.g., to the BSS color provided in the operation element by the AP). As another example, the non-AP STA may set the TXVECTOR parameter BSS_COLOR for an HE TB PPDU or EHT TB PPDU to the active BSS color of the BSS.

[0108] As illustrated, AP 1102 transmits a feedback request frame 1112. For example, feedback request frame 1112 may be a trigger frame (TF) (e.g., TF 900) transmitted using a non-HT PPDU (e.g., non-HT PPDU 310 illustrated in FIG. 3), HE PPDU (e.g., HE SU PPDU 410, HE MU PPDU 420 or HE ER SU PPDU 430 illustrated in FIG. 4) or EHT MU PPDU (e.g., EHT MU PPDU 510 illustrated in FIG. 5). It is noted that because AP 1102 and 1104 are UHR APs, each AP may receive, and decode, any of the aforementioned PPDUs if the AP supports the PPDU parameters (e.g., MCS, number of spatial streams, bandwidth, etc.). In another example, feedback request frame 1112 may be a QoS data frame with a triggered response scheduling (TRS) control subfield (e.g., instead of a TF). The TRS control subfield of the QoS data frame may be used to signal parameters (e.g., RU allocation, MCS, UL Target Receive Power) needed by a responding AP to transmit a TB PPDU response in the absence of a dedicated TF.

[0109] AP 1104 may respond to feedback request frame 1112 by transmitting a feedback response frame. For example, AP 1104 may transmit a TB PPDU 1114 carrying the feedback response frame. AP 1102 may receive, and decode, TB PPDU 1114 transmitted by AP 1104. It is noted that because TB PPDU 1114 may use parameters (e.g., MCS, number spatial streams, bandwidth, etc.) indicated in the TF or TRS control subfield of feedback request frame 1112, AP 1102 may have the capability to receive TB PPDU 1114. In an example, AP 1104 may set the BSS color in the U-SIG field of TB PPDU 1114 to 2 (i.e., matching the BSS color of the BSS of which AP 1104 is a member). Thus, any receiving STA (including AP 1102) of the TB PPDU 1114 may identify whether TB PPDU 1114 is transmitted by a STA belonging to the receiving STA's own BSS or by a STA belonging to another BSS.

[0110] In an example, AP 1102 may then transmit an unsolicited feedback frame 1116. For example, unsolicited feedback frame 1116 may include a management frame (e.g., a public action frame or an action frame that may be defined in the future to support inter-AP communication). AP 1104 may receive, and decode, unsolicited feedback frame 1116 because, like feedback request frame 1112, AP 1102 transmitsDocket No.: 25-3003PCTunsolicited feedback frame 1116 using a non-HT PPDU (e.g., non-HT PPDU 310 illustrated in FIG. 3), HE PPDU (e.g., HE SU PPDU 410, HE MU PPDU 420 and HE ER SU PPDU 430 illustrated in FIG. 4) or EHT MU PPDU (e.g., EHT MU PPDU 510 illustrated in FIG. 5). In an example, when unsolicited feedback frame 1116 is transmitted using an HE PPDU or EHT MU PPDU, the PPDU may indicate in the BSS color field of the PPDU the BSS color that identifies the BSS from which the PPDU originates. Thus in example 1100, TB PPDU 1114 may indicate a BSS color of 2 (e.g., the BSS color of the BSS of which AP 1104 is a member) in the U-SIG field while unsolicited feedback frame 1116 may indicate a BSS color of 1 (e.g., the BSS color of the BSS of which AP 1102 is a member) in the HE-SIG-A field (in case of HE PPDU) or U-SIG field (in case of EHT MU PPDU).

[0111] FIG. 12 illustrates an example that highlights a potential problem that may arise in inter-AP communication.

[0112] Example 1200 includes APs 1202, 1204 and 1206. In an example, APs 1202, 1204 and 1206 operate according to the IEEE 802.11 bn standard amendment and may be referred to as UHR APs. AP 1202, 1204 and AP 1206 may undertake inter-AP coordination for a variety of UHR features, including Co-BF, Co-SR, r-TWT operation, and seamless roaming. This inter-AP coordination may require AP 1202, AP 1204 and AP 1206 to exchange management frames (e.g., an r-TWT schedule, a BSR, and other suitable management frames). For example, AP 1202 may solicit and receive feedback from AP 1204 and AP 1206. AP 1202 may also provide unsolicited feedback to AP 1204 and AP 1206.

[0113] As illustrated, AP 1202, AP 1204, and AP 1206 set their BSS colors to 1, 2, and 3 respectively. Each of AP 1202, AP 1204, and AP 1206 may then transmit an operation element (e.g., HE operation element) indicating the respective BSS color in management frames that each transmits (e.g., beacons, association responses, or probe responses). In addition, each of AP 1202, AP 1204, and AP 1206 may set the TXVECTOR parameter BSS_COLOR of HE PPDUs (e.g., HE SU PPDU 410, HE MU PPDU 420 and HE ER SU PPDU 430 illustrated in FIG. 4) or EHT MU PPDUs, that the AP transmits, to 1, 2, or 3 respectively. For a non-AP STA associated with either AP 1202, AP 1204, or AP 1206 (not shown in FIG. 12), the STA may set the TXVECTOR parameter BSS_COLOR of HE PPDUs or EHT MU PPDUs that it transmits to the value indicated in an operation element that the non-AP STA receives from its associated AP. As another example, the non-AP STA may set the TXVECTOR parameter BSS_COLOR for an HE TB PPDU or EHT TB PPDU to the active BSS color of the BSS.

[0114] As illustrated, AP 1202 transmits a feedback request frame 1212. In an embodiment, feedback request frame 1212 may solicit a TB PPDU from AP 1204. For example, feedback request frame 1212 may be a TF (e.g., TF 900) transmitted using a non-HT PPDU (e.g., non-HT PPDU 310 illustrated in FIG. 3), HE PPDU (e.g., HE SU PPDU 410, HE MU PPDU 420 or HE ER SU PPDU 430 illustrated in FIG. 4) or EHT MU PPDU (e.g., EHT MU PPDU 510 illustrated in FIG. 5). It is noted that because AP 1202, 1204 and 1206 are UHR APs, each AP may receive, and decode, any of the aforementioned PPDUs if the AP supports theDocket No.: 25-3003PCTPPDU parameters (e.g., MCS, number of spatial streams, bandwidth, etc.). In another example, feedback request frame 1212 may be a QoS data frame with a TRS control subfield instead of a TF. The TRS control subfield of the QoS data frame may be used to signal parameters (e.g., RU allocation, MCS, UL Target Receive Power) needed by a responding AP to transmit a TB PPDU response in the absence of a dedicated TF.

[0115] AP 1204 may respond to feedback request frame 1212 by transmitting a TB PPDU 1214 carrying a feedback response frame. Similarly, AP 1206 may respond to feedback request frame 1212 by transmitting a TB PPDU 1216 carrying another feedback response frame. In an embodiment, TB PPDUs 1214 and 1216 may be transmitted using non-overlapping resource units or spatial streams. In an embodiment, each of TB PPDUs 1214 and 1216 carrying feedback response frames may be transmitted concurrently as illustrated in FIG. 12. It is noted that because each of TB PPDUs 1214 and TB PPDU 1216 may use parameters (e.g., MCS, number spatial streams, bandwidth, etc.) indicated in the TF or TRS control subfield of feedback request frame 1212, AP 1202 may receive TB PDDU 1214 or TB PPDU 1216 if they are transmitted one at a time. In the illustrated example, however, AP 1202 may not receive, and decode, TB PPDUs 1214 and 1216 because TB PPDUs 1214 and 1216 are transmitted concurrently with inconsistent parameter settings.

[0116] For example, AP 1204 may set the BSS color in the U-SIG field of TB PPDU 1214 to 2. On the other hand, AP 1206 may set the BSS color in the U-SIG field of TB PPDU 1216 to 3. Because of these different values set by the APs in the U-SIG of TB PPDUs 1214 and 1216, a STA receiving the concurrent TB PPDU transmissions may not successfully decode the U-SIG of either of the TB PPDUs 1214 or 1216. In an example, AP 1202 may not receive, and decode, the feedback frames carried in TB PPDUs 1214 and 1216 due to U-SIG detection error. It is noted that this U-SIG detection error may not occur for concurrent TB PPDU transmissions in a single BSS (e.g., TB PPDU 1020 in example 1000), because in a single BSS all TB PPDUs may indicate the same BSS color.

[0117] Further, in an example, feedback request frame 1212 may solicit TB PPDUs from one or more non-AP STAs associated with AP 1202 (e.g., in addition to soliciting feedback from AP 1204). In an example, when the non-AP STAs transmit TB PPDUs to associated AP 1202 (e.g., in response to feedback request frame 1212), the STAs may set the TXVECTOR parameter BSS_COLOR of the TB PPDUs to the value indicated in an operation element that the respective STA receives from its associated AP (e.g., 1 for associated STAs of AP 1202). The STAs may transmit the TB PPDUs, in response to feedback request frame 1212, concurrently with TB PPDU 1214 from AP 1204 and / or TB PPDU 1216 from AP 1206. AP 1202 may not receive, and decode, TB PPDUs 1214 and / or 1216 because TB PPDUs 1214 and / or 1216 are transmitted concurrently with the TB PPDUs from the non-AP STAs associated with AP 1202, with inconsistent parameter settings (e.g., inconsistent BSS color values in the respective U-SIG fields, causing a U-SIG detection error for AP 1202).Docket No.: 25-3003PCT

[0118] T ransmission of solicited feedback from one AP to another AP may, therefore, be limited to a single AP at a time to prevent U-SIG detection error. But single AP feedback for solicited TB PPDUs prevents the initiating AP from using OFDMA, or MU-MIMO, to solicit feedback from multiple APs simultaneously. Further, when an AP is soliciting TB PPDUs from associated non-AP STAs, the AP may not be able to solicit feedback from another AP as well. This can lead to significant inefficiencies in inter-AP communication and negative impacts on communication performance.

[0119] Embodiments of the present disclosure, as further described below, address the above-described problem associated with existing technologies. In an aspect, a first AP transmits a frame indicating a first BSS color of a BSS of which the first AP is a member. The first AP may receive, from a second AP, a trigger frame soliciting a first TB PPDU from the first AP. The first AP may then transmit to the second AP and in response to the trigger frame, the first TB PPDU, wherein based on the trigger frame further soliciting a second TB PPDU from a third AP, a BSS color field of the first TB PPDU comprises a second BSS color different than the first BSS color. In one embodiment, the second BSS color matches a third BSS color of a BSS of which the second AP is a member. In another embodiment, the second BSS color is a predetermined BSS color. In another embodiment, the second BSS color may be indicated in a frame received from the second AP prior to receiving the trigger frame. In another embodiment, the second BSS color may be indicated in a frame transmitted, by the first AP to the second AP, prior to receiving the trigger frame. In another embodiment, the second BSS color may be indicated in the trigger frame. In one or more of the aforementioned embodiments, the BSS color fields in the U-SIGs of the TB PPDUs transmitted by the first AP and the third AP may have consistent values, avoiding the problem of reception error when the second AP receives the concurrently solicited TB PPDUs.

[0120] As described further below, this may improve performance by allowing an AP to more efficiently solicit feedback from one or more other APs.

[0121] FIG. 13 illustrates an example 1300 of an example operation according to an embodiment. Example 1300 includes APs 1302, 1304, and 1306. In example 1300, AP 1302 may be a member of a BSS with a BSS color equal to 1. Further, in an embodiment, AP 1304 is a member of another BSS with a BSS color equal to 2. In an embodiment, AP 1306 is a member of a third BSS, with a BSS color equal to 3. Each of APs 1302, AP 1304 and AP 1306 may transmit an operation element (e.g., an HE operation element) indicating the respective BSS color, in management frames that each transmits (e.g., beacons, association responses, probe responses). In addition, each of AP 1302, AP 1304, and AP 1306 may set the TXVECTOR parameter BSS_COLOR of HE PPDUs (e.g., HE SU PPDU 410, HE MU PPDU 420 and HE ER SU PPDU 430 illustrated in FIG. 4) or EHT MU PPDUs, that the AP transmits, to 1, 2, and 3 respectively. For a non-AP STA associated with either AP 1302, AP 1304, or AP 1306 (not shown in FIG. 13), the STA may set the TXVECTOR parameter BSS_COLOR of HE PPDUs or EHT MU PPDUs that it transmits to the value indicated in aDocket No.: 25-3003PCTreceived operation element from its associated AP. In addition, the non-AP STA may set the TXVECTOR parameter BSS_COLOR for an HE TB PPDU or EHT TB PPDU to the active BSS color of the BSS.

[0122] As illustrated, AP 1302 transmits a frame 1310. In an embodiment, frame 1310 may be a beacon frame. In such an embodiment, frame 1310 may be a beacon frame that AP 1302 transmits to its associated STAs to provide access parameters within the BSS. In an embodiment, frame 1310 includes a BSS color subfield provided in an operation element (e.g., an HE operation element) and indicating a BSS color of 1 (as illustrated in example 1300). In another embodiment, frame 1310 may be a public action frame. In an embodiment, a public action frame may be used by a STA (e.g., AP 1302) to communicate with an inter-BSS AP (e.g., AP 1304 and AP 1306). In such an embodiment, the action frame may include a BSS color subfield indicating the value of 1 . In an example, AP 1304 and AP 1306 may receive frame 1310. AP 1304 and AP 1306 may also decode the BSS color from frame 1310 (e.g., the BSS color of 1 set by AP 1302).

[0123] As illustrated, AP 1302 transmits a feedback request frame 1312 soliciting a feedback response from both AP 1304 and AP 1306. For example, feedback request frame 1312 may be a TF (e.g., TF 900) transmitted using a non-HT PPDU (e.g., non-HT PPDU 310 illustrated in FIG. 3). In another example, feedback request frame 1312 may be a QoS data frame with a TRS control subfield instead of a TF. In another example, feedback request frame 1312 may be an initial control frame (ICF) that is used by AP 1302 to announce its intention of sharing a time portion of an obtained TXOP with AP 1304 and / or AP 1306.

[0124] In an embodiment, AP 1302 may further solicit a TB PPDU (e.g., to carry uplink data frames, not shown in FIG. 13) from one or more associated non-AP STAs using feedback request frame 1312. In an embodiment, after a respective STA associated with AP 1302 receives feedback request frame 1312, soliciting a TB PPDU, the STA may respond by transmitting the TB PPDU to AP 1302 In an example, the respective STA may set a TXVECTOR parameter BSS_COLOR, for the TB PPDU, to the active BSS color of AP 1302 (e.g., 1).

[0125] In an example, AP 1304 receives feedback request frame 1312. In an embodiment, feedback request frame 1312 solicits a TB PPDU from AP 1304. In response to feedback request frame 1312, AP 1304 may transmit a TB PPDU 1314 carrying a feedback response frame. In an example, AP 1306 also receives feedback request frame 1312. Feedback request frame 1312 may also solicit a TB PPDU from AP 1306 in addition to soliciting a TB PPDU from AP 1304. In response, AP 1306 may transmit a TB PPDU 1316 carrying another feedback response frame. In an embodiment, each of the TB PPDUs 1314 and 1316 may use nonoverlapping resource units or spatial streams. It is noted that because each of the TB PPDUs 1314 and 1316 may use parameters (e.g., MCS, number spatial streams, bandwidth, etc.) indicated in the TF or TRS control subfield of feedback request frame 1312, AP 1302 may have the capability to receive TB PPDUs 1314 and 1316.

[0126] In an embodiment, AP 1304 may set the BSS color field of the U-SIG field of TB PPDU 1314 to a BSS color that is different from its own BSS color (e.g., different from the BSS color of the BSS of which APDocket No.: 25-3003PCT1304 is a member). As illustrated in FIG. 13, AP 1304 sets the BSS color subfield in the U-SIG field of TB PPDU 1314 to 1, the BSS color of AP 1302 (i.e., the BSS color of the BSS of which AP 1302 is a member).

[0127] In an embodiment, AP 1304 may set the BSS color subfield of TB PPDU 1314 to the BSS color of the TXOP holder / owner AP. For example, AP 1302 may obtain the TXOP (e.g., prior to transmitting frame 1312). AP 1302 may hold / own the TXOP during transmission of frame 1312 and TB PPDU 1314. AP 1304 may set the BSS color subfield of TB PPDU 1314 to 1 , the BSS color of AP 1302 (i.e., the BSS color of the BSS of which AP 1302, the TXOP holder / owner, is a member).

[0128] In an embodiment, AP 1304 sets the BSS color field of TB PPDU 1314 to 1 based on feedback request frame 1312 soliciting TB PPDUs from both AP 1304 and AP 1306. For example, feedback request frame 1312 may indicate that it is soliciting TB PPDUs from both AP 1304 and AP 1306, and AP 1304 may set the BSS color field of TB PPDU 1314 to 1 based on this indication. In another embodiment, AP 1304 sets the BSS color field of TB PPDU 1314 to 1 based on feedback request frame 1312 soliciting TB PPDUs from both AP 1304 and at least one associated STAof AP 1302. For example, feedback request frame 1312 may indicate that it is soliciting TB PPDUs from both AP 1304 and an associated STA, and AP 1304 may set the BSS color field of TB PPDU 1314 to 1 based on this indication. In an example, when feedback request frame 1312 is a TF, AP 1304 may set the BSS color field of TB PPDU 1314 to 1 when the TF includes at least one more user info field assigned to another AP or STA (e.g., AP 1306 or a STA associated with AP 1302), in addition to a user info field assigned to AP 1304. In another example, AP 1304 may set the BSS color field of TB PPDU 1314 to 1 when a field in feedback request frame 1312 indicates setting the BSS color field of TB PPDU 1314 to 1 . In an example, when feedback request frame 1312 is a TF (e.g., TF 900), the reserved fields in the common info field (e g., bit B22) or user info field (e.g., bit B25) may be used to provide the indication.

[0129] In further embodiments, AP 1306 may also set the BSS color subfield in the U-SIG field of TB PPDU 1316 to 1. In an embodiment, AP 1306 also sets the BSS color field ofTB PPDU 1316 to 1 based on feedback request frame 1312 soliciting TB PPDUs from both AP 1304 and AP 1306.

[0130] In another embodiment, AP 1306 sets the BSS color field of TB PPDU 1316 to 1 based on feedback request frame 1312 soliciting TB PPDUs from both AP 1306 and at least one associated STA. For example, feedback request frame 1312 may indicate that it is soliciting TB PPDUs from both AP 1306 and an associated STA of AP 1302, and AP 1306 may set the BSS color field of TB PPDU 1316 to 1 based on this indication. As one example, feedback request frame 1312 may indicate that it is soliciting TB PPDUs from both AP 1304 and AP 1306, and AP 1306 may set the BSS color field of TB PPDU 1316 based on this indication. In an example, when feedback request frame is a TF, AP 1306 may set the BSS color field of TB PPDU 1316 to 1 when the TF includes at least one more user info field assigned to another AP or STA (e.g., AP 1306 or a STA associated with AP 1302), in addition to a user info field assigned to AP 1306. In another example, AP 1306 may set the BSS color field of TB PPDU 1316 to 1 when a field in feedback request frameDocket No.: 25-3003PCT1312 indicates setting the BSS color field of TB PPDU 1316 to 1. In an example, when feedback request frame 1312 is a TF (e.g. , TF 900), the reserved fields in the common info field (e.g., bit B22) or user info field (e.g., bit B25) may be used to provide the indication.

[0131] In an embodiment, AP 1306 may set the BSS color subfield of TB PPDU 1316 to the BSS color of the TXOP holder / owner AP. For example, AP 1302 may obtain the TXOP (e.g., prior to transmitting frame 1312). AP 1302 may hold / own the TXOP during transmission of frame 1312 and TB PPDU 1316. AP 1306 may set the BSS color subfield of TB PPDU 1316 to 1 , the BSS color of AP 1302 (i.e., the BSS color of the BSS of which AP 1302, the TXOP holder / owner, is a member).

[0132] In an embodiment, AP 1302 may then receive, and decode, TB PPDUs 1314 and / or 1316 carrying respective feedback frames, because of consistent parameter settings in TB PPDUs 1314 and 1316. In an embodiment, AP 1302 may further receive TB PPDUs carrying UL frames from an associated STAs, in addition to TB PPDUs 1314 and / or TB PPDU 1316. For example, TB PPDUs 1314 and 1316, and TB PPDUs transmitted by STAs associated with AP 1302, may each have a BSS color field of their respective U-SIG fields set to 1 . Further, in an embodiment, AP 1304 and AP 1306 may set a UL / DL field (e.g., B6 of U-SIG- 1 in U-SIG field 800) of TB PPDUs 1314 and 1316 to indicate UL transmission of a PPDU addressed to an AP (e.g., AP 1304 and AP 1306 may set the respective UL / DL fields of TB PPDUs 1314 and 1316 to a value of 1). In further embodiments, AP 1302 may transmit an acknowledgement frame (e.g., ACK, block acknowledgement (BA), or multi-STA BA) to AP 1304 and / or AP 1306 after successful reception of the feedback frames.

[0133] In an embodiment, one or more of these described aspects may improve performance by allowing an AP to more efficiently solicit feedback from one or more other APs.

[0134] FIG. 14 illustrates an example 1400 of a further example operation according to an embodiment. Example 1400 includes APs 1302, 1304, and 1306. In an embodiment, AP 1302, AP 1304, and AP 1306 are described above with reference to example 1300 illustrated in FIG. 13.

[0135] As illustrated, AP 1302 transmits a feedback request frame 1412 soliciting a feedback response from both AP 1304 and AP 1306. For example, feedback request frame 1412 may be a TF (e.g., TF 900) transmitted using a non-HT PPDU (e.g., non-HT PPDU 310 illustrated in FIG. 3). In another example, request frame 1412 may be a QoS data frame with a TRS control subfield instead of a TF.

[0136] In an example, AP 1304 receives feedback request frame 1412. In an embodiment, feedback request frame 1412 solicits a TB PPDU from AP 1304. In response to feedback request frame 1412, AP 1304 may transmit a TB PPDU 1414 carrying a feedback response frame. In an example, AP 1306 also receives feedback request frame 1412. Feedback request frame 1412 may also solicit a TB PPDU from AP 1306 in addition to soliciting a TB PPDU from AP 1304. In response, AP 1306 may transmit a TB PPDU 1416 carrying another feedback response frame. In an embodiment, each of the TB PPDUs 1414 and 1416 may use nonoverlapping resource units or spatial streams. It is noted that because each of the TB PPDUs 1414 and 1416Docket No.: 25-3003PCTmay use parameters (e.g MCS, number spatial streams, bandwidth, etc.) indicated in the TF or TRS control subfield of request frame 1412, AP 1302 may have the capability to receive TB PPDUs 1414 and 1416 successfully.

[0137] In an embodiment, AP 1304 may set the BSS color field of the U-SIG field of TB PPDU 1414 to a BSS color that is different from its own BSS color (e.g., different from the BSS color of the BSS of which AP 1304 is a member). In an embodiment, AP 1304 may set the BSS color field of the U-SIG field of TB PPDU 1414 to a predetermined value. In an example, AP 1304 may set the BSS color field of the U-SIG field of TB PPDU 1414 to a BSS color used for broadcast transmission or to a BSS color used when at least one recipient STA is not a member of the same BSS as the transmitting AP. As illustrated in FIG. 14, AP 1304 sets the BSS color subfield in the U-SIG field of TB PPDU 1414 to 0.

[0138] In an embodiment, AP 1304 sets the BSS color field of TB PPDU 1414 to a predetermined value based on feedback request frame 1412 soliciting TB PPDUs from both AP 1304 and AP 1306. For example, feedback request frame 1412 may indicate that it is soliciting TB PPDUs from both AP 1304 and AP 1306, and AP 1304 may set the BSS color field of TB PPDU 1414 to 0 based on this indication. In an example, when feedback request frame 1412 is a TF, AP 1304 may set the BSS color field of TB PPDU 1414 to 0 when the TF includes at least one more user info field assigned to another AP (e.g., AP 1306), in addition to a user info field assigned to AP 1304. In another example, AP 1304 may set the BSS color field of TB PPDU 1414 to 0 when a field in feedback request frame 1412 indicates setting the BSS color field ofTB PPDU 1414 to 0. In an example, when feedback request frame 1412 is a TF (e.g., TF 900), the reserved fields in the common info field (e.g., bit B22) or user info field (e.g., bit B25) may be used to provide the indication.

[0139] In further embodiments, AP 1306 may also set the BSS color subfield in the U-SIG field of TB PPDU 1416 to 0. In an embodiment, AP 1306 also sets the BSS color field ofTB PPDU 1416 to 0 based on feedback request frame 1412 soliciting TB PPDUs from both AP 1304 and AP 1306. For example, feedback request frame 1412 may indicate that it is soliciting TB PPDUs from both AP 1304 and AP 1306, and AP 1306 may set the BSS color field of TB PPDU 1416 based on this indication. In an example, when feedback request frame is a TF, AP 1306 may set the BSS color field of TB PPDU 1416 to 0 when the TF includes at least one more user info field assigned to another AP (e.g., AP 1304) in addition to a user info field assigned to AP 1306. In another example, AP 1306 may set the BSS color field of TB PPDU 1416 to 0 when a field in feedback request frame 1412 indicates setting the BSS color field of TB PPDU 1416 to 0. In an example, when feedback request frame 1412 is a TF (e.g., TF 900), the reserved fields in the common info field (e g., bit B22) or user info field (e.g., bit B25) may be used to provide the indication.

[0140] In an embodiment, AP 1302 may then receive, and decode, TB PPDUs 1414 and 1416 carrying respective feedback frames, because of consistent parameter settings in TB PPDUs 1414 and 1416. For example, TB PPDUs 1414 and 1416 may each have a BSS color field of their respective U-SIG fields set to 0. Further, in an embodiment, AP 1304 and AP 1306 may set a UL / DL field (e.g., B6 of U-SIG-1 in U-SIGDocket No.: 25-3003PCTfield 800) of TB PPDUs 1414 and 1416 to indicate UL transmission of a PPDU addressed to an AP (e.g., AP 1304 and AP 1306 may set the respective UL / DL fields of TB PPDUs 1414 and 1416 to a value of 1). In further embodiments, AP 1302 may transmit an acknowledgement frame (e.g., ACK, BA, or multi-STA BA) to AP 1304 and / or AP 1306 after successful reception of the feedback frames.

[0141] In an embodiment, one or more of these described aspects may improve performance by allowing an AP to more efficiently solicit feedback from one or more other APs.

[0142] FIG. 15 illustrates an example 1500 of an additional example operation according to an embodiment. Example 1500 includes APs 1302, 1304, and 1306. In an embodiment, AP 1302, AP 1304, and AP 1306 are described above with reference to example 1300 illustrated in FIG. 13.

[0143] As illustrated, AP 1302 transmits a frame 1510. In an embodiment, frame 1510 may be a public action frame. In such an embodiment, frame 1510 may be a public action frame that AP 1302 transmits to coordinate transmissions with other APs (e.g , AP 1304 and AP 1306). In an embodiment, frame 1510 includes an identifier (e.g., an indication) for coordination between APs 1302, 1304 and 1306. In further embodiments, AP 1304 and / or AP 1306 may transmit to AP 1302, a frame 1511 (illustrated for AP 1304 only) including an identifier (e.g., an indication) or modifying an existing identifier (e.g., an existing indication) for coordination between the APs. In an embodiment, the identifier (e.g., indication) may include an AP group identifier that the coordinating APs (e.g., AP 1302, AP 1304, and AP 1306) may use to identify their AP group. In an embodiment, the identifier (e.g., indication) may include a BSS color that the coordinating APs may use when communicating with other members of the same group of coordinating APs. As illustrated, frame 1510 includes a value of X identifying the AP group of AP 1302, AP 1304 and AP 1306. In an embodiment, X may be a value different from the respective BSS colors of AP 1302, AP 1304 and AP 1306.

[0144] As illustrated, AP 1302 transmits a feedback request frame 1512 soliciting a feedback response from both AP 1304 and AP 1306. For example, feedback request frame 1512 may be a TF (e.g., TF 900) transmitted using a non-HT PPDU (e.g., non-HT PPDU 310 illustrated in FIG. 3). In another example, feedback request frame 1512 may be a QoS data frame with a TRS control subfield instead of a TF.

[0145] In an example, AP 1304 receives feedback request frame 1512. In an embodiment, feedback request frame 1512 solicits a TB PPDU from AP 1304. In response to feedback request frame 1512, AP 1304 may transmit a TB PPDU 1514 carrying a feedback response frame. In an example, AP 1306 also receives feedback request frame 1512. Feedback request frame 1512 may also solicit a TB PPDU from AP 1306 in addition to soliciting a TB PPDU from AP 1304. In response, AP 1306 may transmit a TB PPDU 1516 carrying another feedback response frame. In an embodiment, each of the TB PPDUs 1514 and 1516 may use nonoverlapping resource units or spatial streams. It is noted that because each of the TB PPDUs 1514 and 1516 may use parameters (e.g., MCS, number spatial streams, bandwidth, etc.) indicated in the TF or TRS control subfield of feedback request frame 1512, AP 1302 may have the capability to receive TB PPDUs 1514 and 1516.Docket No.: 25-3003PCT

[0146] In an embodiment, AP 1304 may set the BSS color field of the U-SIG field of TB PPDU 1514 to a BSS color that is different from its own BSS color (e.g., different from the BSS color of the BSS of which AP 1304 is a member). As illustrated in FIG. 15, AP 1304 sets the BSS color subfield in the U-SIG field of TB PPDU 1514 to X, the BSS color identifying the AP group composed of AP 1302, AP 1304 and AP 1306. In an embodiment, AP 1304 sets the BSS color field of TB PPDU 1514 to X based on feedback request frame 1512 soliciting TB PPDUs from both AP 1304 and AP 1306. For example, feedback request frame 1512 may indicate that it is soliciting TB PPDUs from both AP 1304 and AP 1306, and AP 1304 may set the BSS color field of TB PPDU 1514 to X based on this indication. In an example, when feedback request frame 1512 is a TF, AP 1304 may set the BSS color field ofTB PPDU 1514 to X when the TF includes at least one more user info field assigned to another AP (e.g., AP 1306), in addition to a user info field assigned to AP 1304. In another example, AP 1304 may set the BSS color field of TB PPDU 1514 to X when a field in feedback request frame 1512 indicates setting the BSS color field of TB PPDU 1514 to X. In an example, when feedback request frame 1512 is a TF (e.g., TF 900), the reserved fields in the common info field (e.g., bit B22) or user info field (e.g., bit B25) may be used to provide the indication.

[0147] In further embodiments, AP 1306 may also set the BSS color subfield in the U-SIG field of TB PPDU 1516 to X. In an embodiment, AP 1306 also sets the BSS color field of TB PPDU 1516 to X based on feedback request frame 1512 soliciting TB PPDUs from both AP 1304 and AP 1306. For example, feedback request frame 1512 may indicate that it is soliciting TB PPDUs from both AP 1304 and AP 1306, and AP 1306 may set the BSS color field of TB PPDU 1516 based on this indication. In an example, when feedback request frame is a TF, AP 1306 may set the BSS color field of TB PPDU 1516 to X when the TF includes at least one more user info field assigned to another AP (e.g., AP 1304), in addition to a user info field assigned to AP 1306. In another example, AP 1306 may set the BSS color field of TB PPDU 1516 to X when a field in the feedback request frame indicates setting the BSS color field of TB PPDU 1516 to X. In an example, when feedback request frame 1512 is a TF (e.g., TF 900), the reserved fields in the common info field (e.g., bit B22) or user info field (e.g., bit B25) may be used to provide the indication.

[0148] In an embodiment, AP 1302 may then receive, and decode, TB PPDUs 1514 and 1516 carrying respective feedback frames, because of consistent parameter settings in TB PPDUs 1514 and 1516. For example, TB PPDUs 1514 and 1516 may each have a BSS color field of their respective U-SIG fields set to X. Further, in an embodiment, AP 1304 and AP 1306 may set a UL / DL field (e.g., B6 of U-SIG- 1 in U-SIG field 800) of TB PPDUs 1514 and 1516 to indicate UL transmission of a PPDU addressed to an AP (e.g., AP 1304 and AP 1306 may set the respective UL / DL fields of TB PPDUs 1514 and 1516 to a value of 1). In further embodiments, AP 1302 may transmit an acknowledgement frame (e.g., ACK, BA, or multi-STA BA) to AP 1304 and / or AP 1306 after successful reception of the feedback frames.

[0149] In an embodiment, one or more of these described aspects may improve performance by allowing an AP to more efficiently solicit feedback from one or more other APs.Docket No.: 25-3003PCT

[0150] FIG. 16 illustrates an example 1600 of another example operation according to an embodiment. Example 1600 includes APs 1302, 1304, and 1306. In an embodiment, AP 1302, AP 1304, and AP 1306 are described above with reference to example 1300 illustrated in FIG 13.

[0151] As illustrated, AP 1302 transmits a feedback request frame 1612 soliciting a feedback response from both AP 1304 and AP 1306. For example, feedback request frame 1612 may be a TF (e.g., TF 900) transmitted using a non-HT PPDU (e.g., non-HT PPDU 310 illustrated in FIG. 3). In another example, instead of a TF, feedback request frame 1612 may be a QoS data frame with a TRS control subfield. In an embodiment, feedback request frame 1612 may include a value of BSS color for use when transmitting a TB PPDU in response to the feedback request frame 1612. As illustrated, feedback request frame 1612 indicates a value of Y for use as the BSS color value when transmitting a TB PPDU response. In an embodiment, the value for use as a BSS color may be provided in a common info field and / or in a user info field of the feedback request frame 1612 (e.g., as shown in FIG 9).

[0152] In an example, AP 1304 receives feedback request frame 1612. In an embodiment, feedback request frame 1612 solicits a TB PPDU from AP 1304. In response to feedback request frame 1612, AP 1304 may transmit a TB PPDU 1614 carrying a feedback response frame. In an example, AP 1306 also receives feedback request frame 1612. Feedback request frame 1612 may also solicit a TB PPDU from AP 1306 in addition to soliciting a TB PPDU from AP 1304. In response, AP 1306 may transmit a TB PPDU 1616 carrying another feedback response frame. In an embodiment, each of the TB PPDUs 1614 and 1616 may use nonoverlapping resource units or spatial streams. It is noted that because each of the TB PPDUs 1614 and 1616 may use parameters (e.g., MCS, number spatial streams, bandwidth, etc.) indicated in the TF or TRS control subfield of feedback request frame 1612, AP 1302 may have the capability to receive TB PPDUs 1614 and 1616.

[0153] In an embodiment, AP 1304 may set the BSS color field of the U-SIG field of TB PPDU 1614 to a BSS color that is different from its own BSS color (e.g., different from the BSS color of the BSS of which AP 1304 is a member). As illustrated in FIG. 16, AP 1304 sets the BSS color subfield in the U-SIG field of TB PPDU 1614 to Y, the BSS color indicated in feedback request frame 1612. In an embodiment, when feedback request frame 1612 is a TF (e.g., TF 900), the BSS color may be indicated using a one or more bits of the trigger dependent common info field. In another embodiment, the BSS color may be indicated in one or more bits of the trigger dependent user info field. In another embodiment, the BSS color may be indicated in one or more bits of a special user info field

[0154] In an embodiment, AP 1304 sets the BSS color field of TB PPDU 1614 to Y based on feedback request frame 1612 soliciting TB PPDUs from both AP 1304 and AP 1306. For example, feedback request frame 1612 may indicate that it is soliciting TB PPDUs from both AP 1304 and AP 1306, and AP 1304 may set the BSS color field of TB PPDU 1614 to Y based on this indication. In an example, when feedback request frame 1612 is a TF, AP 1304 may set the BSS color field of TB PPDU 1614 to Y when the TF includes atDocket No.: 25-3003PCTleast one more user info field assigned to another AP (e.g., AP 1306), in addition to a user info field assigned to AP 1304. In another example, AP 1304 may set the BSS color field of TB PPDU 1614 to Y when a field in the feedback request frame 1612 indicates setting the BSS color field of TB PPDU 1614 to Y In an example, when feedback request frame 1612 is a TF (e.g., TF 900), the reserved fields in the common info field (e.g., bit B22) or user info field (e.g., bit B25) may be used to provide the indication.

[0155] In further embodiments, AP 1306 may also set the BSS color subfield in the U-SIG field of TB PPDU 1616 to Y. In an embodiment, AP 1306 also sets the BSS color field ofTB PPDU 1616 to Y based on feedback request frame 1612 soliciting TB PPDUs from both AP 1304 and AP 1306. For example, feedback request frame 1612 may indicate that it is soliciting TB PPDUs from both AP 1304 and AP 1306, and AP 1306 may set the BSS color field of TB PPDU 1616 based on this indication. In an example, when feedback request frame is a TF, AP 1306 may set the BSS color field of TB PPDU 1616 to 1 when the TF includes at least one more user info field assigned to another AP (e.g., AP 1304), in addition to a user info field assigned to AP 1306. In another example, AP 1306 may set the BSS color field of TB PPDU 1616 to Y when a field in the feedback request frame indicates setting the BSS color field of TB PPDU 1616 to Y. In an example, when feedback request frame 1612 is a TF (e.g., TF 900), the reserved fields in the common info field (e.g., bit B22) or user info field (e.g., bit B25) may be used to provide the indication.

[0156] AP 1302 may then receive, and decode, TB PPDUs 1614 and 1616 carrying respective feedback frames, because of consistent parameter settings in TB PPDUs 1614 and 1616. For example, TB PPDUs 1614 and 1616 may each have a BSS color field of their respective U-SIG fields set to Y. Further, in an embodiment, AP 1304 and AP 1306 may set a UL / DL field (e.g., B6 of U-SIG- 1 in U-SIG field 800) of TB PPDUs 1614 and 1616 to indicate UL transmission of a PPDU addressed to an AP (e.g., to a value of 1) In further embodiments, AP 1302 may transmit an acknowledgement frame (e.g., ACK, BA, or multi-STA BA) to AP 1304 and / or AP 1306 after successful reception of the feedback frames.

[0157] In an embodiment, one or more of these described aspects may improve performance by allowing an AP to more efficiently solicit feedback from one or more other APs.

[0158] FIG. 17 illustrates an example 1700 of another example operation according to an embodiment. Example 1700 includes APs 1302, 1304, and 1306. In an embodiment, AP 1302, AP 1304, and AP 1306 are described above with reference to example 1300 illustrated in FIG. 13.

[0159] As illustrated, AP 1302 transmits a feedback request frame 1712 soliciting a feedback response from both AP 1304 and AP 1306. For example, feedback request frame 1712 may be a TF (e.g., TF 900) transmitted using a non-HT PPDU (e.g., non-HT PPDU 310 illustrated in FIG. 3). In another example, request frame 1712 may be a QoS data frame with a TRS control subfield instead of a TF.

[0160] In an example, AP 1304 receives feedback request frame 1712. In an embodiment, feedback request frame 1712 solicits a TB PPDU from AP 1304. In response to feedback request frame 1712, AP 1304 may transmit a TB PPDU 1714 carrying a feedback response frame. In an example, AP 1306 also receives theDocket No.: 25-3003PCTfeedback request frame 1712. Feedback request frame 1712 may also solicit a TB PPDU from AP 1306 in addition to soliciting a TB PPDU from AP 1304. In response, AP 1306 may transmit a TB PPDU 1716 carrying another feedback response frame. In an embodiment, each of the TB PPDUs 1714 and 1716 may use nonoverlapping resource units or spatial streams. It is noted that because each of the TB PPDUs 1714 and 1716 may use parameters (e.g., MCS, number spatial streams, bandwidth, etc.) indicated in the TF or TRS control subfield of request frame 1712, AP 1302 may have the capability to receive TB PPDUs 1714 and 1716.

[0161] In an embodiment, TB PPDU 1714 and TB PPDU 1716 may include a U-SIG field having two BSS color fields (e.g., B7-B12 and B20-B25 of U-SIG-1 in U-SIG field 800 illustrated in FIG. 8). In an embodiment, AP 1304 may set the first BSS color field of the U-SIG field of TB PPDU 1714 (e.g., B7-B12 of U-SIG-1 in U-SIG field 800) to its own BSS color and the second BSS color field (e.g., B20-B25 of U-SIG-1 in U-SIG field 800) to a BSS color that is different from its own BSS. As illustrated in FIG. 17, AP 1304 sets the first BSS color subfield in the U-SIG field of TB PPDU 1714 to 2, and the second BSS color subfield of the U-SIG field to 3 (e.g., the BSS color of the BSS of which AP 1306 is a member).

[0162] In an embodiment, AP 1304 sets the first and second BSS color fields based on feedback request frame 1712 soliciting TB PPDUs from both AP 1304 and AP 1306. For example, feedback request frame 1712 may indicate that it is soliciting TB PPDUs from both AP 1304 and AP 1306, and AP 1304 may set the first and second BSS color fields of TB PPDU 1714 based on this indication. In an example, when feedback request frame is a TF, AP 1304 may set the first and second BSS color fields of TB PPDU 1714 when the TF includes at least one more user info field assigned to another AP (e.g. AP 1306), in addition to a user info field assigned to AP 1304. In another example, AP 1304 sets the first and second BSS color fields of TB PPDU 1714 based on an indication in a field in the feedback request frame. In an example, when feedback request frame 1712 is a TF (e.g., TF 900), the reserved fields in the common info field (e.g., bit B22) or user info field (e.g., bit B25) may be used to provide the indication.

[0163] In another embodiment, AP 1304 may set the first BSS color subfield in the U-SIG field of TB PPDU 1714 to 2, and the second BSS color subfield of the U-SIG field to 1 (e.g., the BSS color of the BSS of which AP 1302 is a member). In an embodiment, AP 1304 sets the first and second BSS color fields based on feedback request frame 1712 soliciting TB PPDUs from AP 1304 without any other user info fields in the feedback request frame that are addressed to other APs (e.g., aside from the user info field for AP 1304). For example, feedback request frame 1712 may indicate that it is soliciting a TB PPDU only from AP 1304, and AP 1304 may set the first and second BSS color fields of TB PPDU 1714 based on this indication. In an example, when feedback request frame is a TF, AP 1304 may set the first and second BSS color fields of TB PPDU 1714 when the TF does not include at least one more user info field assigned to another AP. In another example, AP 1304 sets the first and second BSS color fields of TB PPDU 1714 based on an indication in a field in the feedback request frame. In an example, when feedback request frame 1712 is a TF (e.g., TF 900),Docket No.: 25-3003PCTthe reserved fields in the common info field (e.g., bit B22) or user info field (e.g., bit B25) may be used to provide the indication.

[0164] In further embodiments, AP 1306 may set the first BSS color field of the U-SIG field of TB PPDU 1716 (e.g., B7-B12 of U-SIG- 1 in U-SIG field 800) to a BSS color that is different from its own BSS color and the second BSS color field (e.g., B20-B25 of U-SIG- 1 in U-SIG field 800) to its own BSS color. As illustrated in FIG. 17, AP 1306 sets the first BSS color subfield in the U-SIG field of TB PPDU 1716 to 2 (e.g., the BSS color field of the BSS of which AP 1304 is a member), and the second BSS color subfield of the U-SIG field to 3.

[0165] In an embodiment, AP 1306 sets the first and second BSS color fields based on feedback request frame 1712 soliciting TB PPDUs from both AP 1304 and AP 1306. For example, feedback request frame 1712 may indicate that it is soliciting TB PPDUs from both AP 1304 and AP 1306, and AP 1306 may set the first and second BSS color fields of TB PPDU 1716 based on this indication. In an example, when feedback request frame is a TF, AP 1306 may set the first and second BSS color fields of TB PPDU 1716 when the TF includes at least one more user info field assigned to another AP (e.g. AP 1304), in addition to a user info field assigned to AP 1306. In another example, AP 1306 sets the first and second BSS color fields of TB PPDU 1716 based on an indication in a field in the feedback request frame. In an example, when feedback request frame 1712 is a TF (e.g., TF 900), the reserved fields in the common info field (e.g., bit B22) or user info field (e.g., bit B25) may be used to provide the indication.

[0166] In another embodiment, AP 1304 may set the first BSS color subfield in the U-SIG field of TB PPDU 1716 to 3, and the second BSS color subfield of the U-SIG field to 1 (e.g., the BSS color of the BSS of which AP 1302 is a member). In an embodiment, AP 1306 sets the first and second BSS color fields based on feedback request frame 1712 soliciting TB PPDUs from AP 1306 without any other user info fields in the feedback request frame that are addressed to other APs (e.g., aside from the user info field for AP 1306). For example, feedback request frame 1712 may indicate that it is soliciting a TB PPDU only from AP 1306, and AP 1306 may set the first and second BSS color fields of TB PPDU 1716 based on this indication. In an example, when feedback request frame is a TF, AP 1306 may set the first and second BSS color fields of TB PPDU 1716 when the TF does not include at least one more user info field assigned to another AP. In another example, AP 1306 sets the first and second BSS color fields of TB PPDU 1716 based on an indication in a field in the feedback request frame. In an example, when feedback request frame 1712 is a TF (e.g., TF 900), the reserved fields in the common info field (e.g , bit B22) or user info field (e.g , bit B25) may be used to provide the indication..

[0167] AP 1302 may then receive, and decode, TB PPDUs 1714 and 1716 carrying respective feedback frames, because of consistent parameter settings in TB PPDUs 1714 and 1716. For example, TB PPDUs 1714 and 1716 may each have a first BSS color field of their respective U-SIG fields set to 2. Further, TB PPDUs 1714 and 1716 may each have a second BSS color field of their respective U-SIG fields set to 3.Docket No.: 25-3003PCTFurther, in an embodiment, AP 1304 and AP 1306 may set a UL / DL field (e.g., B6 of U-SIG- 1 in U-SIG field 800) of TB PPDUs 1714 and 1716 to indicate UL transmission of a PPDU addressed to an AP (e.g., to a value of 1). In further embodiments, AP 1302 may transmit an acknowledgement frame (e.g., ACK, BA, or multi-STA BA) to AP 1304 and / or AP 1306 after successful reception of the feedback frames.

[0168] In an embodiment, one or more of these described aspects may improve performance by allowing an AP to more efficiently solicit feedback from one or more other APs.

[0169] As would be understood by a person of skill in the art based on the teachings herein, the embodiments as described by the above examples may be readily extended to implementations including more than one STA.

[0170] As would be understood by a person of skill in the art based on the teachings herein, the embodiments as described by the above examples may be readily extended to implementations including more than one AP.

[0171] As would be understood by a person of skill in the art based on the teachings herein, the embodiments as described by the above examples may be readily extended to scenarios in which any of the APs or any of the STAs may comprise a MLD, comprising at least one affiliated AP or affiliated STA.

[0172] FIG. 18 illustrates an example process 1800 according to an embodiment. Example process 1800 may be performed by a suitable AP, such as AP 1304 or AP 1306 illustrated in FIGS. 13-17, for example. As shown in FIG. 18, process 1800 may include steps 1802 and 1804.

[0173] Step 1802 includes receiving, by a first access point (AP) from a second AP, a first frame soliciting a first TB PPDU from the first AP. The second AP may be any suitable AP, such as AP 1302 illustrated in FIGS. 13-17, for example.

[0174] In an embodiment, the first frame is a trigger frame. In another embodiment, the first frame is a QoS data frame addressed to the first AP and comprising a TRS control subfield.

[0175] In an embodiment, the first frame further solicits one or more second TB PPDUs from one or more respective third APs.

[0176] Step 1804 includes transmitting, by the first AP to the second AP and in response to the first frame, the first TB PPDU, wherein a BSS color field of the first TB PPDU comprises a first BSS color different than a second BSS color of a BSS of which the first AP is a member.

[0177] In an embodiment, the U-SIG field of the first TB PPDU comprises the BSS color field.

[0178] In an embodiment, the first TB PPDU comprises a UL / DL field. The UL / DL field may indicate that the first TB PPDU is addressed to an AP.

[0179] In an embodiment, process 1800 may include transmitting, by the first AP, a second frame comprising the second BSS color. In such an embodiment, the second BSS color may be provided in an operation element of the second frame. In an embodiment, the second frame may be beacon or an action frame.Docket No.: 25-3003PCT

[0180] In an embodiment, whether the BSS color field of the first TB PPDU comprises the first BSS color or the second BSS color, is based on the first frame soliciting the one or more second TB PPDUs.

[0181] In an embodiment, process 1800 may further include receiving, by the first AP from the second AP, a third frame acknowledging the first TB PPDU.

[0182] In an embodiment, process 1800 may further include transmitting, by the first AP to the second AP, a fourth frame comprising a first indication. In another embodiment, process 1800 may further include receiving, by the first AP from the second AP, a fifth frame comprising a second indication. In further embodiments, the first BSS color is based on at least one of the first indication or the second indication.

[0183] In an embodiment, the first BSS color identifies a group comprising the first AP and the second AP.

[0184] In an embodiment, the first BSS color comprises a BSS color different from both the second BSS color and from a third BSS color of a BSS of which the second AP is a member.

[0185] In an embodiment, the first BSS color matches a third BSS color of a BSS of which the second AP is a member.

[0186] In an embodiment, process 1800 may include receiving, by the first AP from the second AP, a sixth frame comprising the first BSS color.

[0187] In an embodiment, the first BSS color matches a predetermined BSS color. In further embodiments, the predetermined BSS color is a broadcast BSS color. In further embodiments, the predetermined BSS color is 0.

[0188] In an embodiment, the first frame comprises an indication of the first BSS color. In further embodiments, the first BSS color is provided in a common info field or a special user info field of the first frame.

[0189] In additional embodiments, the first TB PPDU further comprises a second BSS color field. In such embodiments, the first BSS color field may indicate a fourth BSS color of a BSS of which a fourth AP is a member. In addition, the second BSS color field may indicate a fifth BSS color of the BSS of which the first AP is a member.

[0190] FIG. 19 illustrates an example process 1900 according to an embodiment. Example process 1900 may be performed by a suitable AP, such as AP 1302 illustrated in FIGS. 13-17, for example. As shown in FIG. 19, process 1900 may include steps 1902 and 1904.

[0191] Step 1902 includes transmitting, by a first access point (AP) to a second AP, a first frame soliciting a first TB PPDU from the second AP.

[0192] In an embodiment, the U-SIG field of the first TB PPDU comprises the BSS color field.

[0193] In an embodiment, the first TB PPDU comprises a UL / DL field. The UL / DL field may indicate that the first TB PPDU is addressed to an AP.

[0194] In an embodiment, the first frame is a trigger frame. In another embodiment, the first frame is a QoS data frame addressed to the second AP and comprising a TRS control subfield.Docket No.: 25-3003PCT

[0195] In an embodiment, the first frame further solicits one or more second TB PPDUs from one or more respective third APs.

[0196] Step 1904 includes receiving, by the first AP from the second AP and in response to the first frame, the first TB PPDU, wherein a basic service set (BSS) color field of the first TB PPDU comprises a first BSS color different than a second BSS color of a BSS of which the second AP is a member.

[0197] In an embodiment, process 1900 may include receiving, by the first AP, a second frame comprising the second BSS color. In such an embodiment, the second BSS color is provided in an operation element of the second frame. In further embodiments, the second frame comprises a beacon or an action frame.

[0198] In an embodiment, the first frame may further solicit a second TB PPDU from a third AP. In an embodiment, the first TB PPDU comprising a first BSS color different than the second BSS is based on the first frame soliciting the second TB PPDU. In an embodiment, process 1900 further includes receiving, by the first AP from the third AP and in response to the first frame, the second TB PPDU. In an embodiment, a second BSS color field of the second TB PPDU comprises the first BSS color.

[0199] In an embodiment, process 1900 may further include transmitting, by the first AP to the second AP, a third frame acknowledging the first TB PPDU.

[0200] In an embodiment, process 1900 may further include, receiving by the first AP from the second AP, a fourth frame comprising a first indication. In an embodiment, process 1900 may further include, transmitting by the first AP to the second AP, a fifth frame comprising a second indication.

[0201] In an embodiment, the first BSS color is based on at least one of the first indication or the second indication. In another embodiment, the first BSS color identifies a group comprising the first AP and the second AP. In further embodiments, the first BSS color comprises a BSS color different from both the second BSS color and from a third BSS color of a BSS of which the first AP is a member.

[0202] In an embodiment, the first BSS color matches the third BSS color of a BSS of which the first AP is a member.

[0203] In an embodiment, process 1900 may further include, transmitting, by the first AP to the second AP, a sixth frame comprising the first BSS color.

[0204] In an embodiment, the first BSS color matches a predetermined BSS color. In such an embodiment, the predetermined BSS color may be a broadcast BSS color. In further embodiments, the predetermined BSS color is O.

[0205] In an embodiment, the first frame comprises an indication of the first BSS color. In an embodiment, the first BSS color is provided in a common info field or a special user info field of the first frame.

[0206] In additional embodiments, the first TB PPDU further comprises a second BSS color field. In such embodiments, the first BSS color field may indicate a fourth BSS color of a BSS of which a fourth AP is a member. In addition, the second BSS color field may indicate a fifth BSS color of the BSS of which the second AP is a member.Docket No.: 25-3003PCT

[0207] In an embodiment, an AP or STA in accordance with the above-described embodiments (e.g., any AP or STA as described in FIGS. 11-19) may perform operations as described below. A person of skill in the art based on the teachings herein would appreciate that the below described features and operations may be readily combined with the above-described embodiments.

[0208] In an aspect, one or more rules related to a PHY interface of a UHR STA may include setting TXVECTOR parameters for a UHR PPDU. A UHR STA may set the TXVECTOR parameter STAJD following rules applicable to STA_I D, with the following additions. The rules that apply to an EHT MU PPDU may also apply to a UHR MU PPDU and to a UHR enhanced long range (ELR) PPDU.

[0209] A UHR STA may set the TXVECTOR parameter POWER_BOOST_FACTOR following rules applicable to POWER_BOOST_FACTOR, with the following additions. The rules that apply to an OFDMA EHT MU PPDU may also apply to an OFDMA UHR MU PPDU. The rules that apply to a non-OFDMA EHT MU PPDU may also apply to a non-OFDMA UHR MU PPDU. The POWER_BOOST_FACTOR may not be present in the TXVECTOR in a UHR TB PPDU or a UHR ELR PPDU.

[0210] A UHR STA may set the TXVECTOR parameter UPLINK_FLAG following rules applicable to UPLINK_FLAG, with the following additions. The rules that apply to an EHT MU PPDU may also apply to a UHR MU PPDU. The rules that apply to an HE ER PPDU may also apply to a UHR ELR PPDU.

[0211] A UHR STA may set the TXVECTOR parameter BSS_COLOR following rules applicable to BSS_COLOR, with the following additions. The rules that apply to an EHT MU PPDU may also apply to a UHR MU PPDU. A UHR STA that transmits a UHR ELR PPDU may set the TXVECTOR parameter BSS COLOR to the BSS Color subfield of a most recently received or transmitted HE Operation element exchanged within the BSS of which the UHR STA is a member. A value of 0 for the TXVECTOR parameter BSS_COLOR may be disallowed for ELR PPDUs.

[0212] A UHR STA may set the TXVECTOR parameter TXOP_DURATION following rules applicable to TXOP_DURATION, with the following additions. The rules that apply to an EHT MU PPDU may also apply to a UHR MU PPDU. The rules that apply to an HE ER PPDU may also apply to a UHR ELR PPDU.

Claims

Docket No.: 25-3003PCTCLAIMSWhat is claimed is:

1. A method comprising:transmitting, by a first access point (AP), a frame comprising a first basic service set (BSS) color of a BSS of which the first AP is a member;receiving, by the first AP from a second AP, a trigger frame soliciting a first trigger based (TB) physical layer (PHY) protocol data unit (PPDU) from the first AP; andtransmitting, by the first AP to the second AP and in response to the trigger frame, the first TB PPDU, wherein based on the trigger frame further soliciting a second TB PPDU from a third AP, a BSS color field of the first TB PPDU comprises a second BSS color different than the first BSS color.

2. A method comprising:receiving, by a first access point (AP) from a second AP, a first frame soliciting a first trigger based (TB) physical layer (PHY) protocol data unit (PPDU) from the first AP; and transmitting, by the first AP to the second AP and in response to the first frame, the first TB PPDU, wherein a basic service set (BSS) color field of the first TB PPDU comprises a first BSS color different than a second BSS color of a BSS of which the first AP is a member.

3. The method of claim 2, wherein a universal signal (U-SIG) field of the first TB PPDU comprises the BSS color field.

4. The method of any of claims 2-3, wherein the first TB PPDU comprises an uplink ( U L) / downl in k (DL) field.

5. The method of claim 4, wherein the UL / DL field indicates that the first TB PPDU is addressed to an AP.

6. The method of any of claims 2-5, wherein the first frame comprises at least one of:a trigger frame; ora quality of service (QoS) data frame comprising a triggered response scheduling (TRS) control subfield.

7. The method of any of claims 2-6, further comprising, transmitting, by the first AP, a second frame comprising the second BSS color.

8. The method of claim 7, wherein the second BSS color is provided in an operation element of the second frame.

9. The method of any of claims 7-8, wherein the second frame comprises a beacon or an action frame.

10. The method of any of claims 2-9, wherein the first frame further solicits one or more second TB PPDUs from one or more respective third APs.Docket No.: 25-3003PCT11. The method of claim 10, wherein the BSS color field of the first TB PPDU comprising a first BSS color different than the second BSS color of the BSS of which the first AP is a member is based on the first frame soliciting the one or more second TB PPDUs.

12. The method of any of claims 2-11, further comprising receiving, by the first AP from the second AP, a third frame acknowledging the first TB PPDU.

13. The method of any of claims 2-12, further comprising, transmitting by the first AP to the second AP, a fourth frame comprising a first indication.

14. The method of any of claims 2-13, further comprising, receiving by the first AP from the second AP, a fifth frame comprising a second indication.

15. The method of any of claims 13-14, wherein the first BSS color is based on at least one of the first indication or the second indication.

16. The method of any of claims 2-15, wherein the first BSS color identifies a group comprising the first AP and the second AP.

17. The method of any of claims 2-15, wherein the first BSS color comprises a BSS color different from both the second BSS color and from a third BSS color of a BSS of which the second AP is a member.

18. The method of any of claims 2-14, wherein the first BSS color matches a third BSS color of a BSS of which the second AP is a member.

19. The method of claim 18, further comprising, receiving, by the first AP from the second AP, a sixth frame comprising the first BSS color.

20. The method of any of claims 2-14, wherein the first BSS color matches a predetermined BSS color.

21. The method of claim 20, wherein the predetermined BSS color is a broadcast BSS color.

22. The method of any of claims 20-21 , wherein the predetermined BSS color is 0.

23. The method of any of claims 2-14, wherein the first frame comprises an indication of the first BSS color.

24. The method of claim 23, wherein the first BSS color is provided in a common info field or a special user info field of the first frame.

25. The method of claim 2, wherein the first TB PPDU further comprises a second BSS color field.

26. The method of claim 25, wherein the first BSS color field comprises a fourth BSS color of a BSS of which a fourth AP is a member.

27. The method of any of claims 25-26, wherein the second BSS color field comprises a fifth BSS color of the BSS of which the first AP is a member.

28. A method comprising:receiving, by a first access point (AP) from a second AP, a frame comprising a first basic service set (BSS) color of a BSS of which the second AP is a member;Docket No.: 25-3003PCTtransmitting, by the first AP to the second AP, a trigger frame soliciting a first trigger based (TB) physical layer (PHY) protocol data unit (PPDU) from the second AP; andreceiving, by the first AP from the second AP and in response to the trigger frame, the first TB PPDU, wherein based on the trigger frame further soliciting a second TB PPDU from a third AP, a BSS color field of the first TB PPDU comprises a second BSS color different than the first BSS color.

29. A method comprising:transmitting, by a first access point (AP) to a second AP, a first frame soliciting a first trigger based (TB) physical layer (PHY) protocol data unit (PPDU) from the second AP; and receiving, by the first AP from the second AP and in response to the first frame, the first TB PPDU, wherein a basic service set (BSS) color field of the first TB PPDU comprises a first BSS color different than a second BSS color of a BSS of which the second AP is a member.

30. The method of claim 29, wherein a universal signal (U-SIG) field of the first TB PPDU comprises the BSS color field.

31. The method of any of claims 29-30, wherein the first TB PPDU comprises an uplink (UL)Zdownlink (DL) field.

32. The method of claim 31 , wherein the UL / DL field indicates that the first TB PPDU is addressed to an AP.

33. The method of any of claims 29-32, wherein the first frame comprises at least one of:a trigger frame; ora quality of service (QoS) data frame comprising a triggered response scheduling (TRS) control subfield.

34. The method of any of claims 29-33, further comprising, receiving, by the first AP, a second frame comprising the second BSS color.

35. The method of claim 34, wherein the second BSS color is provided in an operation element of the second frame.

36. The method of any of claims 34-35, wherein the second frame comprises a beacon or an action frame.

37. The method of any of claims 29-36, wherein the first frame further solicits a second TB PPDU from a third AP.

38. The method of claim 37, wherein the BSS color field of the first TB PPDU comprising a first BSS color different than the second BSS color of the BSS of which the second AP is a member is based on the first frame soliciting the second TB PPDU.

39. The method of any of claims 37-38, further comprising receiving, by the first AP from the third AP and in response to the first frame, the second TB PPDU.Docket No.: 25-3003PCT40. The method of claim 39, wherein a second BSS color field of the second TB PPDU comprises the first BSS color.

41. The method of any of claims 29-40, further comprising transmitting, by the first AP to the second AP, a third frame acknowledging the first TB PPDU.

42. The method of any of claims 29-41 , further comprising, receiving by the first AP from the second AP, a fourth frame comprising a first indication.

43. The method of any of claims 29-42, further comprising, transmitting by the first AP to the second AP, a fifth frame comprising a second indication.

44. The method of any of claims 42-43, wherein the first BSS color is based on at least one of the first indication or the second indication.

45. The method of any of claims 29-44, wherein the first BSS color identifies a group comprising the first AP and the second AP.

46. The method of any of claims 29-45, wherein the first BSS color comprises a BSS color different from both the second BSS color and from a third BSS color of a BSS of which the first AP is a member.

47. The method of any of claims 29-43, wherein the first BSS color matches a third BSS color of a BSS of which the first AP is a member.

48. The method of claim 47, further comprising, transmitting, by the first AP to the second AP, a sixth frame comprising the first BSS color.

49. The method of any of claims 29-43, wherein the first BSS color matches a predetermined BSS color.

50. The method of claim 49, wherein the predetermined BSS color is a broadcast BSS color.

51. The method of any of claims 49-50, wherein the predetermined BSS color is 052. The method of any of claims 29-43, wherein the first frame comprises an indication of the first BSS color.

53. The method of claim 52, wherein the first BSS color is provided in a common info field or a special user info field of the first frame.

54. The method of claim 29, wherein the first TB PPDU further comprises a second BSS color field.

55. The method of claim 54, wherein the first BSS color field comprises a fourth BSS color of a BSS of which a fourth AP is a member.

56. The method of any of claims 54-55, wherein the second BSS color field comprises a fifth BSS color of the BSS of which the second AP is a member57. A device comprising:one or more processors; andmemory storing instructions that, when executed by the one or more processors, cause the device to perform a method according to any of claims 1-56.Docket No.: 25-3003PCT58. 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

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