Coordinated non-primary channel access operation

Abstract

A first access point (AP) transmits to a second AP a first frame indicating a first non-primary channel access (NPCA) parameter set for the second AP, where the first NPCA parameter set indicates: a first channel location of a first NPCA primary channel (PCH) of the second AP; and a first channel bandwidth of the first NPCA PCH. The first receives from the second AP a second frame indicating acceptance of the first NPCA parameter set by the second AP. After receiving the second frame, the first AP transmits to the second AP a third frame indicating a second NPCA parameter set and a time period during which the second AP uses the second NPCA parameter set instead of the first NPCA parameter set. The second NPCA parameter set indicates a second channel location of the first NPCA PCH and / or a second bandwidth of the first NPCA PCH.

Description

Docket No.: 25-3007PCTTITLE COORDINATED NON-PRIMARY CHANNEL ACCESS OPERATIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 764,595, filed February 28, 2025, which is hereby incorporated by reference in its entirety.BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0006] FIG. 4 illustrates an example trigger frame.

[0007] FIG. 5 illustrates an example multi-user request to send (MU-RTS) trigger frame.

[0008] FIG. 6 illustrates an example common info field.

[0009] FIG. 7 illustrates an example of a Request-to-Send ( RTS) / Clear-to-Send (CTS) procedure.

[0010] FIG. 8 shows an example that illustrates an MU-RTS / CTS procedure.

[0011] FIG. 9 shows an example that illustrates non-primary channel access (NPCA) operation.

[0012] FIG. 10 illustrates virtual and physical carrier sense (CS) functions associated with primary and secondary channels for NPCA operation and non-NPCA operation.

[0013] FIG. 11 shows an example that illustrates NPCA operation.

[0014] FIG. 12 shows an example that illustrates another NPCA operation.

[0015] FIG. 13 illustrates an example multi-AP network.

[0016] FIG. 14 illustrates an example of a multi-AP negotiation procedure including a multi-AP NPCA negotiation phase.

[0017] FIG. 15 illustrates a problem that may arise due to static NPCA configuration in a multi-AP group.

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

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

[0020] FIG. 18 illustrates an example of a further procedure according to an embodiment.

[0021] FIG. 19 illustrates an example of a further procedure according to an embodiment.

[0022] FIG. 20 illustrates an example process according to an embodiment.

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

[0024] 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 beDocket No.: 25-3007PCTapparent 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 those shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments.

[0025] 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.

[0026] 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.

[0027] 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”) is indicative that the phrase following the term “based on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “in response to” (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to" is an example of one of a multitude of suitable possibilities that may, 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”Docket No.: 25-3007PCT(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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g., hardware with a biological element) or a combination thereof, which may be behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab or the like) or a modeling / simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. It may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and / or quantum hardware. Examples of programmable hardware comprise: computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages such as assembly, C, C++, or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardwareDocket No.: 25-3007PCTdescription 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.

[0032] FIG. 1 illustrates example wireless communication networks in which embodiments of the present disclosure may be implemented.

[0033] 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.

[0034] 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.

[0035] 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 130 and may have the same service set identification (SSID).

[0036] 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.

[0037] 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 (i.e., not via an AP).

[0038] For example, in FIG. 1, STAs 106-4, 106-5, and 106-6 maybe configured to form a first IBSS 112-1. Similarly, STAs 106-7 and 106-8 may be configured to form a second IBSS 112-2. Since an IBSS does not include an AP, it does not include a centralized management entity. Rather, STAs within an IBSS are managed in a distributed manner. STAs forming an IBSS may be fixed or mobile.

[0039] 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” maybe 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.

[0040] 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 PHY service data unit (PSDU). For example, the PSDU may include a PHY preamble and header and / or one or more MAC protocol data units (MPDUs). The information provided in the PHY preamble may beDocket No.: 25-3007PCTused by a receiving device to decode the subsequent data in the PSDU. In instances in which PPDUs are transmitted overa 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.

[0041] A frequency band may include one or more sub-bands or frequency channels. For example, PPDUs conforming to the IEEE 802.11n, 802.11ac, 802.11 ax and / or 802.11 be standard amendments may be transmitted over the 2.4 GHz, 5 GHz, and / or 6 GHz bands, each of which may be divided into multiple 20 MHz channels. The PPDUs may be transmitted over a physical channel having a minimum bandwidth of 20 MHz. Larger channels may be optionally formed through channel bonding of a primary 20 MHz channel and one or more 20 MHz secondary channels For example, PPDUs may be transmitted over physical channels having bandwidths of 40 MHz, 80 MHz, 160 MHz, or 320 MHz by bonding together a primary 20 MHz channel and 1, 3, 7, or 15 secondary channel respectively. The primary channel is a common channel operation for all STAs where management frames are sent by the AP to ensure that all STAs (regardless of channel bonding support) can receive.

[0042] FIG. 2 is a block diagram illustrating example implementations of a STA 210 and an AP 260. As shown in FIG.2, STA 210 may include at least one processor 220, a memory 230, and at least one transceiver 240. AP 260 may include at least one processor 270, a memory 280, and at least one transceiver 290. Processor 220 / 270 may be operatively connected to memory 230 / 280 and / or to transceiver 240 / 290.

[0043] Processor 220 / 270 may implement functions of the PHY layer, the MAC layer, and / or the logical link control (LLC) layer of the corresponding device (STA 210 or AP 260). Processor 220 / 270 may include one or more processors and / or one or more controllers. The one or more processors and / or one or more controllers may comprise, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a logic circuit, or a chipset, for example.

[0044] 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-transi tory 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.

[0045] Transceiver 240 / 290 may be configured to transmit / receive radio signals. In an embodiment, transceiver 240 / 290 may implement a PHY layer of the corresponding device (STA 210 or AP 260). In an embodiment, STA 210 and / or AP 260 may be a multi-link device (MLD), that is a device capable of operating over multiple links as defined byDocket No.: 25-3007PCTthe 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.

[0046] FIG. 3 illustrates an example format of a MAC frame. In operation, a STA may construct a subset of MAC frames for transmission and may decode a subset of received MAC frames upon validation. The particular subsets of frames that a STA may construct and / or decode may be determined by the functions supported by the STA. A STA may validate a received MAC frame using the frame check sequence (FCS) contained in the frame and may interpret certain fields from the MAC headers of all frames.

[0047] As shown in FIG. 3, a MAC frame includes a MAC header, a variable length frame body, and a frame check sequence (FCS).

[0048] The MAC header includes a frame control field, an optional duration / ID field, address fields, an optional sequence control field, an optional QoS control field, and an optional HT control field.

[0049] 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.

[0050] The protocol version subfield is invariant in size and placement across all revisions of the IEEE 802.11 standard. The value of the protocol version subfield is 0 for MAC frames.

[0051] The type and subtype subfields together identify the function of the MAC frame. There are three frame types: control, data, and management. Each of the frame types has several defined subtypes. Bits within the subtype subfield are used to indicate a specific modification of the basic data frame (subtype 0). For example, in data frames, the most significant bit (MSB) of the subtype subfield, bit 7 (B7) of the frame control field, is defined as the QoS subfield. When the QoS subfield is set to 1 , it indicates a QoS data frame, which is a data frame that contains a QoS control field in its MAC header. The second MSB of the subtype field, bit 6 (B6) of the frame control field, when set to 1 in data subtypes, indicates a data frame that contain no frame body field.

[0052] The “To DS” subfield indicates whether a data frame is destined to the distribution system (DS). The “From DS” subfield indicates whether a data frame originates from the DS.

[0053] The “More Fragments” subfield is set to 1 in all data or management frames that have another fragment to follow the MAC service data unit (MSDU) or MAC management protocol data unit (MMPDU) carried by the MAC frame. The “More Fragments” subfield is set to 0 in all other frames in which the “More Fragments” subfield is present.

[0054] The retry subfield is set to 1 in any data or management frame that is a retransmission of an earlier frame. It is set to 0 in all other frames in which the retry subfield is present. A receiving STA uses this indication to aid it in the process of eliminating duplicate frames. These rules do not apply for frames sent by a STA under a block agreement.

[0055] The power management subfield is used to indicate the power management mode of a STA.

[0056] The “More Data” subfield indicates to a STA in power save (PS) mode that bufferable units (BUs) are buffered for that STA at the AP. The “More Data” subfield is valid in individually addressed data or management frames transmittedDocket No.: 25-3007PCTby an AP to a STA in PS mode. The “More Data’’ subfield is set to 1 to indicate that at least one additional buffered BU is present for the STA.

[0057] The protected frame subfield is set to 1 if the frame body field contains information that has been processed by a cryptographic encapsulation algorithm.

[0058] The +HTC subfield indicates that the MAC frame contains an HT control field.

[0059] The duration / ID field of the MAC header indicates various contents depending on the frame type and subtype and the QoS capabilities of the sending STA. For example, in control frames of the power save poll (PS-Poll) subtype, the duration / ID field carries an association identifier (AID) of the STA that transmitted the frame in the 14 least significant bits (LSB), with the 2 most significant bits (MSB) set to 1. In other frames sent by STAs, the duration / ID field contains a duration value (in microseconds) which is used by a recipient to update a network allocation vector (NAV). The NAV is a counter that indicates to a STA an amount of time during which the STA must defer from accessing the shared medium.

[0060] Up to four address fields may be present in the MAC frame format. The address fields are used to indicate the basic service set identifier (BSSID), source address (SA), destination address (DA), transmitting address (TA), and receiving address (RA). Certain frames may not contain some of the address fields. Certain address field usage may be specified by the relative position of the address field (1-4) within the MAC header, independent of the type of address present in that field. Specifically, the address 1 field always identifies the intended receiver(s) of the frame, and the address 2 field, where present, always identifies the transmitter of the frame.

[0061] The sequence control field includes two subfields, a sequence number subfield and a fragment number subfield. The sequence number subfield in data frames indicates the sequence number of the MSDU (if not in an Aggregated MSDU (A-MSDU)) or A-MSDU. The sequence number subfield in management frames indicates the sequence number of the frame. The fragment number subfield indicates the number of each fragment of an MSDU or MMPDU. The fragment number is set to 0 in the first or only fragment of an MSDU or MMPDU and is incremented by one for each successive fragment of that MSDU or MMPDU. The fragment number is set to 0 in a MAC protocol data unit (MPDU) containing an A-MSDU, or in an MPDU containing an MSDU or MMPDU that is not fragmented. The fragment number remains constant in all retransmissions of the fragment.

[0062] The QoS control field identifies the traffic category (TC) or traffic stream (TS) to which the MAC frame belongs. The QoS control field may also indicate various other QoS related, A-MSDU related, and mesh-related information about the frame. This information can vary by frame type, frame subtype, and type of transmitting STA. The QoS control field is present in all data frames in which the QoS subfield of the subtype subfield is equal to 1.

[0063] The HT control field is present in QoS data, QoS null, and management frames as determined by the +HTC subfield of the frame control field.

[0064] The frame body field is a variable length field that contains information specific to individual frame types and subtypes. The frame body may include one or more MSDUs or MMPDUs. The minimum length of the frame body is 0 octets.Docket No.: 25-3007PCT

[0065] The FCS field contains a 32-bit Cyclic Redundancy Check (CRC) code. The FCS field value is calculated over all of the fields of the MAC header and the frame body field.

[0066] FIG. 4 illustrates an example trigger frame 400. Trigger frame 400 may correspond to a basic trigger frame as defined in the existing IEEE 802.11ax standard amendment. Trigger frame 400 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 400 may also carry other information required by a responding STA to transmit a TB PPDU to the AP.

[0067] As shown in FIG. 4, trigger frame 400 includes a Frame Control field, a Duration field, a receiver address (RA) field, a transmitter address (TA) field, a Common Info field, a User List Info field, a Padding field, and an FCS field.

[0068] 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.

[0069] 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).

[0070] 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 400 if trigger frame 400 is addressed to STAs that belong to a single BSS. The TA field is the transmitted BSSID if the trigger frame 400 is addressed to STAs from at least two different BSSs of the multiple BSSID set.

[0071] The common info field may have a format as illustrated by common info field 600 described further below. The common info field specifies a trigger frame type of trigger frame 400, a transmit power of trigger frame 400 in dBm, and several key parameters of a TB PPDU that is transmitted by a STA in response to trigger frame 400. 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.

[0072] The User List Info field contains a User Info field per STA addressed in trigger frame 400. The per STA User Info field includes, among others, an AID subfield, an RU Allocation subfield, a Spatial Stream (SS) Allocation subfield, an MCS subfield to be used by a STA in a TB PPDU transmitted in response to trigger frame 400, and a Trigger Dependent User Info subfield. 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

[0073] The Padding field is optionally present in trigger frame 400 to extend the frame length to give recipient STAs enough time to prepare a response for transmission one SIFS (short interframe spacing) after the frame is received. The Padding field, if present, is at least two octets in length and is set to all 1s.

[0074] 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.Docket No.: 25-3007PCT

[0075] FIG. 5 illustrates an example multi-user request to send (MU-RTS) trigger frame 500. MU-RTS trigger frame 500 may be used by an AP to solicit simultaneous CTS frames from multiple STAs to transmit a downlink (DL) MU PPDU to the multiple STAs. As shown in FIG. 5, MU-RTS trigger frame 500 may comprise a frame control field, a duration field, an RA field, a TA field, a common info field, one or more user info fields, a padding field, and an FCS field. The frame control, TA, RA, padding, and FCS fields may be similar to the corresponding fields of trigger frame 400 described above. The common info field may have a format as illustrated by common info field 600 described further below. The duration field may be set to the time, in microseconds, required to transmit the DL MU PPDU, plus the time required to transmit one CTS frame, one ACK frame (if required), and three SIFS periods.

[0076] The one or more user info fields correspond respectively to the one or more STAs solicited by MU-RTS trigger frame 500. As shown in FIG. 5, a user info field may comprise an AID12 subfield, an RU allocation subfield, reserved bits, and a PS 160 subfield. The AID12 subfield comprises an association identifier of the STA to which the user info field is addressed. The RU allocation subfield indicates a channel on which the solicited STA is to transmit the CTS frame. In an example, this may include a primary 20 MHz channel, a primary 40 MHz, a primary 80 MHz channel, a primary 160 MHz, an 80+80 Mhz channel, or a 320 MHz channel.

[0077] FIG. 6 illustrates an example Common Info field 600. Common Info field 600 may be an embodiment of the Common Info field of trigger frame 400 or MU-RTS trigger frame 500, for example. As shown in FIG. 6, Common Info field 600 may include a Trigger Type subfield, a UL Length subfield, a More TF subfield, a CS required subfield, a UL BW subfield, a Gl and HE / EHT-LTF Type / Triggered TXS Mode subfield, a first Reserved subfield, a Number of HE / EHT-LTF Symbols subfield, a second Reserved subfield, an LDPC Extra Symbol Segment subfield, an AP Tx Power subfield, a Pre-FEC Padding Factor subfield, a PE Disambiguity subfield, an UL Spatial Reuse subfield, a third Reserved subfield, an HE / EHT P160 subfield, a Special User Info Field Flag subfield, an EHT Reserved subfield, a fourth Reserved subfield, and a Trigger Dependent Common Info subfield. The Trigger Type subfield, UL Length subfield, More TF subfield, CS required subfield, UL BW subfield, Gl and HE-LTF Type / Triggered TXS Mode subfield, first Reserved subfield, Number of HE / EHT-LTF Symbols subfield, second Reserved subfield, LDPC Extra Symbol Segment subfield, AP Tx Power subfield, Pre-FEC Padding Factor subfield, PE Disambiguity subfield, UL Spatial Reuse subfield, third Reserved subfield, HE / EHT P160 subfield, Special User Info Field Flag subfield, EHT Reserved subfield, fourth Reserved subfield, and Trigger Dependent Common Info subfield may have the same content and interpretation as corresponding subfields of an EHT variant Common Info field defined in the IEEE 802.11 be draft amendment (“IEEE P802.11be / D3.1, March 2023”).

[0078] FIG. 7 illustrates an example 700 of a Request-to-Send (RTS) / Clear-to-Send (CTS) procedure. Example 700 may be an example according to the RTS / CTS procedure as defined in section 10.3.2.9 of the IEEE 802.11 standard draft “IEEE P802.11 -REVme™ / D3.0, April 2023." As shown in FIG. 7, example 700 may include STAs 702 and 704. Other STAs of the same BSS may also be within communication range of STAs 702 and 704.

[0079] In an example, STA 702 may transmit an RTS frame 706 to STA 704. STA 702 may transmit RTS frame 706 to protect from hidden STA(s) the transmission of a data frame 710 that STA 702 intends to transmit. RTS frame 706 mayDocket No.: 25-3007PCTinclude a Duration / ID field. The Duration / ID field may be set to the time, in microseconds, required to transmit data frame 710, plus one CTS frame, plus one ACK frame (if required), plus three SIFS (Short Interframe Spacing) periods.

[0080] In an example, STA 704 may respond to RTS frame 706 by transmitting a CTS frame 708 to STA 702. CTS frame 708 may be transmitted one SIFS period after RTS frame 706. STA 704 may respond to RTS frame 706 when RTS frame 706 is addressed to STA 704 and after considering the NAV, unless the NAV was set by a frame originating from STA 702. STA 704 may respond to the RTS frame 706 when RTS frame 706 is addressed to STA 704 and if the NAV indicates idle. For a non-S1 G STA, the NAV indicates idle when the NAV count is 0 or when the NAV count is nonzero but a nonbandwidth signaling TA obtained from a TA field of RTS frame 706 matches a saved TXOP holder address. For an S1G STA, the NAV indicates idle when both the NAV and RID (response indication deferral) counters are 0 or when either the NAV or RID counter is non-zero but the TA field of RTS frame 706 matches the saved TXOP holder address.

[0081] STA 704 may set an RA field of CTS frame 708 to a nonbandwidth signaling TA obtained from the TA field of RTS frame 706. STA 704 may set a Duration field of CTS frame 708 based on the Duration / ID field of RTS frame 706, namely as equal to the value of the Duration / ID field of RTS frame 706, adjusted by subtracting the time required to transmit CTS frame 708 and one SIFS period.

[0082] Upon receiving CTS frame 708, STA 702 may wait one SIFS period before transmitting data frame 710. STA 704 may transmit an ACK frame 712 in response to data frame 710. STA 704 may transmit ACK frame 712 one SIFS after receiving data frame 710.

[0083] As shown in example 700, other STAs within communication range of STAs 702 and 704, and belonging to the same BSS, may set their NAVs according to RTS frame 706 and / or CTS frame 708. For example, a STA receiving RTS frame 706 may set its NAV based on the Duration / ID field of RTS frame 706. Another STA receiving CTS frame 708 may set its NAV based on the Duration field of CTS frame 708. As such, the other STAs may not access the channel using EDCA until the end of transmission of ACK frame 712.

[0084] FIG. 8 shows an example 800 that illustrates a multi-user Request-to-Send (MU-RTS)ZCIear-to-Send (CTS) procedure. Example 800 may be an example according to the MU-RTS / CTS procedure as defined in section 26.2.6 of the IEEE 802.11 standard draft. As shown in FIG.8, example 800 may include an AP 802 and STAs 804 and 806. STAs 804 and 806 may be associated with AP 802. For the purpose of illustration, example 800 also illustrates STAs of an overlapping basic service set (OBSS) relative to the BSS of AP 802 (OBSS STAs). The OBSS STAs, as shown in FIG.8, may be hidden from AP 802 (outside of the communication range of AP 802) or exposed to AP 802 (within the communication range of AP 802)

[0085] In example 800, AP 802 wishes to transmit a downlink (DL) multi-user (MU) PPDU 814 to STAs 804 and 806. DL MU PPDU 814 may comprise data for each of STAs 804 and 806. DL MU PPDU 814 may occupy a plurality of channels (e.g., 20 MHz channels). Each channel of the plurality of channels may carry the data for a respective STA (e.g„ STA 804, STA 806) served by DL MU PPDU 814.Docket No.: 25-3007PCT

[0086] As shown in FIG. 8, to protect the transmission of DL MU PPDU 814 to STAs 804 and 806 from interference by OBSS STAs hidden from AP 802, AP 802 may use the MU-RTS / CTS procedure to initiate a TXOP and to protect the TXOP frame exchange sequence. AP 802 may initiate the TXOP by transmitting an MU-RTS trigger frame 808 that solicits simultaneous CTS frame transmissions from STAs 804 and 806.

[0087] MU-RTS trigger frame 808 may have a format as illustrated by MU-RTS trigger frame 500 illustrated in FIG. 5. As such, MU-RTS trigger frame 808 may comprise a frame control field, a duration field, an RA field, a TA field, a common info field, one or more user info fields, a padding field, and an FCS field. The duration field may be set to the time, in microseconds, required to transmit DL MU PPDU 814, plus the time required to transmit one CTS frame, one ACK frame (if required), and three SIFS periods.

[0088] The one or more user info fields correspond respectively to the one or more STAs solicited by the MU-RTS trigger frame. In example 800, MU-RTS trigger frame 808 may comprise a user info field for each of STAs 804 and 806 indicating that a CTS frame is solicited from each of STAs 804 and 806. As shown in FIG.8, a user info field may comprise an AID12 subfield, an RU allocation subfield, reserved bits, and a PS 160 subfield. The AID12 subfield comprises an association identifier of the STA to which the user info field is addressed. The RU allocation subfield indicates a channel on which the solicited STA is to transmit the CTS frame. In an example, this may include a primary 20 MHz channel, a primary 40 MHz, a primary 80 MHz channel, a primary 160 MHz, an 80+80 Mhz channel, or a 320 MHz channel.

[0089] AP 802 may send MU-RTS trigger frame 808 in a PPDU that occupies one or more channels (e.g., 20 MHz channels). In an example, for each channel occupied by the PPDU that carries MU-RTS trigger frame 808, AP 802 may request at least one non-AP STA to send a CTS frame that occupies that channel. In an example, AP 802 may not request that a non-AP STA send a CTS frame that occupies a channel that is not occupied by the PPDU carrying MU-RTS trigger frame 808.

[0090] After transmitting MU-RTS trigger frame 808, AP 802 may wait for a CTSTimeout interval of aSIFSTime + aSlotTime + aRxPHYStartDelay that begins when a MAC layer of AP 802 receives a PHYTXEND.confirm primitive for transmitted MU-RTS trigger frame 808. If the MAC layer does not receive a PHY-RXEARLYSIG. indication or a PHY-RXSTART.indication primitive during the CTSTimeout interval, AP 802 may conclude that the transmission of MU-RTS trigger frame 808 has failed, and, if MU-RTS trigger frame 808 initiated a TXOP, AP 802 may invoke its backoff procedure. If the MAC layer receives a PHY-RXEARLYSIG.indication or a PHY-RXSTART.indication primitive during the CTSTimeout interval, then the MAC layer may wait for the corresponding PHY-RXEND. indication primitive to determine whether transmission of MU-RTS trigger frame 808 was successful. The receipt of a CTS frame from any non-AP STA addressed by MU-RTS trigger frame 808 before the PHY-RXEND.indication primitive shall be interpreted as the successful transmission of MU-RTS trigger frame 808, permitting the frame exchange sequence to continue. The receipt of any other type of frame shall be interpreted as a failure of the transmission of MU-RTS trigger frame 808. AP 802 may process the received frame and, if MU-RTS trigger frame 808 initiated a TXOP, AP 802 shall invoke its backoff procedure at the PHY-RXEND.indication primitive.Docket No.: 25-3007PCT

[0091] In example 800, on receiving MU-RTS trigger frame 808, STAs804 and 806 respond by transmitting respectively CTS frames 810 and 812 to AP 802. In an example, STAs 804 and 806 begin the transmission of CTS frames 810 and 812, respectively, at the SIPS time boundary after an end of a received PPDU comprising MU-RTS trigger frame 808. In an example, STA 804 (or STA 806) responds to MU-RTS trigger frame 808 with a CTS frame when the following conditions are met: MU-RTS trigger frame 808 comprises a user info field addressed to the STA (the AID12 subfield of the user info field is equal to the 12 LSBs of the AID of the STA) and MU-RTS trigger frame 808 is sent by an AP with which the STA is associated; and the UL MU CS condition indicates that the medium is idle as described in section 26.5.2.5 (UL MU CS mechanism) of the IEEE 802.11 standard (“IEEE P802.11-REVme™ / D3.0, April 2023”). Otherwise, if one of the conditions is not met, STA 804 (or STA 806) does not send a CTS frame to AP 802.

[0092] In an example, STAs 804 and 806 may set an RA field of respectively CTS frames 810 and 812 to a TA obtained from the TA field of MU-RTS trigger frame 808. In an example, STAs 804 and 806 may set a duration field of respectively CTS frames 810 and 812 based on the duration field of MU-RTS trigger frame 808, namely as equal to the value of the duration field of MU-RTS trigger frame 808, adjusted by subtracting the time required to transmit respectively CTS frames 810 and 812 and one SIPS period.

[0093] OBSS STAs exposed to AP 802 may receive MU-RTS trigger frame 808 due to being within the communication range of AP 802. In an example, as shown in FIG. 8, on receiving MU-RTS trigger frame 808, OBSS STAs exposed to AP 802 set their respective NAVs based on the duration field of MU-RTS trigger frame 808. As such, the OBSS STAs exposed to AP 802 may not access the wireless medium for the duration of the TXOP initiated by AP 802.

[0094] OBSS STAs hidden from AP 802 do not receive MU-RTS trigger frame 808 due to being outside the communication range of AP 802. However, in an example, as shown in FIG.8, some of the OBSS STAs hidden from AP 802 may receive CTS frame 810 and / or CTS frame 812 and may set their respective NAVs based on the duration field of CTS frame 810 and / or CTS frame 812. As such, some of the OBSS STAs hidden from AP 802 may also not access the wireless medium for the duration of the TXOP initiated by AP 802.

[0095] On receiving CTS frame 810 and / or CTS frame 812, AP 802 may wait one SIPS period before transmitting DL MU PPDU 814. On receiving DL MU PPDU 814, STAs 804 and 806 may respond by transmitting respective BlockAck (BA) frames 816 and 818 to AP 802.

[0096] In accordance with embodiments of the present disclosure, a STA (non-AP STA or AP STA) may support NPCA operation as further described below. When the STA is a non-AP STA that supports NPCA operation, the STA is referred to as an NPCA STA and may perform the NPCA STA operations / procedures described further below. When the STA is an AP STA that supports NPCA operation, the STA is referred to as an NPCA AP and may perform the NPCA AP operations / procedures described further below.

[0097] A non-AP NPCA STA may set an NPCA Supported field of a UHR MAC Capabilities Information field of a UHR Capabilities element to 1. In an implementation, a non-AP NPCA STA does not enable the NPCA mode unless the non-AP NPCA STA is associated with an NPCA AP that has enabled NPCA operation.Docket No.: 25-3007PCT

[0098] In an implementation, an NPCA AP that has an operating bandwidth less than 80 MHz does not enable NPCA operation. In an implementation, an AP of a multiple BSSID set that enables NPCA operation may indicate the same NPCA primary channel, same NPCA minimum duration, same NPCA switching delay, and same NPCA switch back delay as all of the other APs of the same multiple BSSID set that have enabled NPCA operation. In an implementation, an AP of a co-hosted BSS that enables NPCA operation may indicate the same NPCA primary channel, same NPCA minimum duration, same NPCA switching delay, and same NPCA switch back delay as all of the other APs of the same co-hosted BSSs that have enabled NPCA operation.

[0099] In an implementation, an NPCA AP that has enabled NPCA operation may set to 1 the NPCA Enabled field in the UHR Operation element of the (Re)Association Response, UHR Link Reconfiguration Notify, Beacon and Probe Response frames that it transmits.

[0100] In an implementation, an NPCA AP with a value (e.g. , dot11 HEPSROptionlmplemented) set to true may set the TXVECTOR parameter SPATIAL_REUSE to PSR_DISALLOW for PPDUs that it transmits, and may set the PSR Disallowed subfield in the SR Control field of the Spatial Reuse Parameter Set element to 1 in Management frames it transmits before enabling NPCA operation in its BSS and while NPCA operation remains enabled.

[0101] In an implementation, an AP may enable a PHY Header-based (PHYLEN) NPCA operation by setting a MAC Header-based (MOPLEN) NPCA field to 0 and may enable both PHYLEN NPCA and MOPLEN NPCA operation by setting the MOPLEN NPCA field to 1.

[0102] In an implementation, an NPCA AP may advertise an NPCA Disabled Subchannel Bitmap field in the NPCA Operation Parameters field. The NPCA Disabled Subchannel Bitmap field may indicate the subchannels that are punctured when an NPCA STA operates on the NPCA primary channel:If an NPCA Disabled Subchannel Bitmap field is present, then the NPCA Disabled Subchannel Bitmap Field Present bit may be set to 1, otherwise the NPCA Disabled Subchannel Bitmap Field Present field maybe set to 0.The NPCA Disabled Subchannel Bitmap field value may satisfy the following requirements:o The puncturing pattern indicated by the value of the NPCA Disabled Subchannel Bitmap field is a valid non-OFDMA puncturing pattern.o A 20 MHz subchannel indicated as punctured in the Disabled Subchannel Bitmap field of an EHT Operation element (if any) is also indicated as punctured in the NPCA Disabled Subchannel Bitmap field.An NPCA AP may indicate one or more 20 MHz subchannels as punctured in the NPCA Disabled Subchannel Bitmap field of the EHT Operation Element for the purpose of maximizing the BW of the NPCA operating channel.An NPCA AP may indicate one or more 20 MHz subchannels as punctured in the NPCA Disabled Subchannel Bitmap field of the EHT Operation Element for the purpose of creating a gap between the PPDU that initiated the NPCA switch and the NPCA operating channel.If no NPCA Disabled Subchannel Bitmap field is present in the NPCA Operation Parameters field transmitted by the AP that the STA is associated with, then the subchannels may be punctured during NPCA operation.Docket No.: 25-3007PCT

[0103] In an implementation, an NPCA AP may indicate a value in the NPCA Primary Channel field, of transmitted NPCA Operation Parameters fields, that corresponds to a channel that is located within the secondary 40 MHz of the BSS operating channel if the BSS is an 80 MHz BSS, that corresponds to a channel that is located within the secondary 80 MHz of the BSS operating channel if the BSS is a 160 MHz BSS, and that corresponds to a channel that is located within the secondary 160 MHz of the BSS operating channel if the BSS is a 320 MHz BSS.

[0104] In an implementation, a non-AP NPCA STA may indicate an NPCA switching delay and an NPCA switch back delay, respectively, in the NPCA Switching Delay field and NPCA Switch Back Delay fields of the OMP Request frames.

[0105] In an implementation, when a non-AP STA that supports NPCA mode (re)associates with an AP, the NPCA mode may be disabled by default for the non-AP STA. In the LIHR OMP request sent to enable or update the parameters of NPCA mode for the non-AP STA, a non-AP STA may include the following in the Mode Parameters field of the Mode Tuple field:NPCA switching delay,NPCA switch back delay.

[0106] In an implementation, for a non-AP STA to enable NPCA mode, the associated AP must support NPCA and must have NPCA enabled for the BSS.

[0107] In an implementation, if an NPCA AP that has enabled NPCA operation advertises MU EDCA parameters in the Beacon frames that it transmits, a MU EDCA protocol may apply jointly on both BSS primary channel and NPCA primary channel for a non-AP NPCA STA. In an implementation, an NPCA STA may maintain a single MU EDCA timer that is shared across the BSS primary channel and the NPCA primary channel, transition from using EDCA parameters to using MU EDCA parameters (and vice-versa) at the same time on both the BSS primary channel and the NPCA primary channel based on certain conditions that occur on either the BSS primary channel or the NPCA primary channel, and when the STA is operating on the NPCA primary channel, use the same MU EDCA parameters as are used on the BSS primary channel except that Al FS N [AC] may be set to 0 for all ACs. When the STA switches back to the BSS primary channel, it may revert to using the AIFSNjAC] values from the dot1 IMUEDCATable.

[0108] In an implementation, an NPCA STA does not switch to the NPCA primary channel for NPCA operation if NPCA mode has not been enabled by its associated AP.

[0109] In an implementation, an NPCA STA may switch to the NPCA primary channel for NPCA operation if the NPCA mode has been enabled for the BSS of which it is a member and either condition 1) or 2) is met:1) the STA received a PPDU and / or received a PHY-RXSTART.indication primitive for an HE / EHT / UHR PPDU on the BSS primary channel and all of the following conditions are true:a) Condition 2) is not true.b) The PPDU is classified by the STA as in inter-BSS PPDU.c) At least one of the following conditions is true:Docket No.: 25-3007PCT1) The value of the MAC variable NPCA_PPDU_REM_DUR derived from the received PPDU is greater than the value indicated in the most recently received or transmitted NPCA Minimum Duration Threshold field corresponding to the BSS of which the STA is a member.ii) If the NPCA AP corresponding to the BSS of which the STA is a member has enabled MOPLEN NPCA in addition to PHYLEN NPCA and the value of the MAC variable NPCA_PHY_TXOP_REM_DUR derived from the received PPDU is greater than the value indicated in the most recently received or transmitted NPCA Minimum Duration Threshold field corresponding to the BSS of which the STA is a member.d) The bandwidth of the PPDU is determined by the STA to be 20, 40, 80 or 160 MHz, based on the Bandwidth field in the PHY preamble of the PPDU and the channel occupied by the PPDU does not overlap with the NPCA primary channel.e) If the STA maintains an intra-BSS NAV, it is zero.2) All of the following conditions are true:a) A sequence of three PPDUs, separated by aSI FSTime, is identified on the BSS primary channel, comprising an initial Control frame, an initial response frame, and a third PPDU following the initial response frame.b) The STA received at least the first PPDU containing the initial Control frame and the PHY-RXSTART.indication and / or the PHY-RXEARLYSIG.indication of the third PPDU.c) An indication that a valid TXOP was obtained on the BSS primary channel, as verified by the receipt of a PHY-RXEARLYSIG.indication or PHYRXSTART.indication primitive corresponding to the third PPDU that occurs during a time window that:i) begins at aSI FSTime + IC R Timeout after the MAC receives a PHY-RXEND.indication primitive corresponding to the first PPDU, where IC R_Timeout is equal to:(1) The length (in usee) of the expected CTS if the initial Control frame is an RTS or an MU-RTS Trigger frame, (2) the value of RXTIME calculated using Equation (27-147) with the value of LENGTH replaced by the value from the UL Length field of the Common Info field, if the initial Control frame is a BSRP Trigger frame or a BSRP NTB Trigger frame.ii) has a duration that is equal to NPCA_START_TIMEOUT which is aSIFSTime + (2 x aSlotTime) + aRxPHYStartDelay.d) At least one of the three PPDUs in the sequence of PPDUs is classified by the STA as an inter-BSS PPDU. e) At least one of the following conditions is true:i) The NPCA AP corresponding to the BSS of which the STA is a member has enabled PHYLEN NPCA only and the value of the MAC variable NPCA_PPDU_REM_DUR derived from the received third PPDU of the sequence of PPDUs is greater than the value indicated in the most recently received or transmitted NPCA Minimum Duration Threshold field corresponding to its BSS.ii) If the NPCA AP corresponding to the BSS of which the STA is a member has enabled MOPLEN NPCA in addition to PHYLEN NPCA and the value of the MAC variable NPCA_CFRAME_TXOP_REM_DUR derived from theDocket No.: 25-3007PCTreceived first PPDU (containing the initial Control frame of the control frame exchange) of the sequence of PPDUs is greater than the value indicated in the most recently received or transmitted NPCA Minimum Duration Threshold field corresponding to its associated BSS.f) The bandwidth of the third PPDU is determined by the STA to be 20, 40, 80, 160 or 320 MHz based on the Bandwidth field in the PHY preamble of the PPDU not overlap with the NPCA primary channel and the channel occupied by the PPDU does not overlap with the NPCA primary channel.g) If the STA maintains an intra-BSS NAV, it is zero at the time of the receipt of the PHYRXSTART.indication and / or the PHY-RXEARLYSIG. indication of the first PPDU.

[0110] In an implementation, when a PHY-CCAJndication(BUSY) primitive corresponding to the start of the reception of a PPDU is indicated at an NPCA STA while operating on the BSS primary channel, the values of the MAC variables NPCA_PPDU_REM_DUR, NPCA_PHY_TXOP_REM_DUR and NPCA_TIMER are all set to 0. When a PHY-CCA.indication(BUSY) corresponding to the start of the reception of a PPDU containing an initial Control frame is indicated at an NPCA STA while operating on the BSS primary channel, the MAC variable NPCA_CFRAME_TXOP_REM_DUR is set to 0.

[0111] In an implementation, the MAC variable NPCA_PPDU_REM_DUR derived from a received PPDU is equal to the value in usee, of the remaining duration of the received PPDU, determined by the MAC at the time of the receipt of the PHY-RXSTART.indication primitive associated with the received PPDU, by subtracting the time elapsed between the reception of the PHY-CCA.indication(BUSY) and PHY-RXSTART.indication primitives associated with the received PPDU from the value of RXTIME of the received PPDU.

[0112] In an implementation, the MAC variable NPCA_PHY_TXOP_REM_DUR derived from a received PPDU is:Set to 0, if the RXVECTOR parameter TXOP_DURATION is UNSPECIFIED, or if the NPCA AP corresponding to the BSS of which the STA is a member has not enabled MOPLEN NPCA.Otherwise, it is equal to the value in usee, of the remaining duration of the PPDU, determined by the MAC at the time of the receipt of the PHY-RXSTART.indication primitive associated with the received PPDU, by subtracting the time elapsed between the reception of the PHY-CCA.indication(BUSY) and PHY-RXSTART.indication primitives associated with the received PPDU from the value of RXTIME corresponding to the received PPDU, plus the value of the TXOP_DURATION parameter of the RXVECTOR of the PPDU.

[0113] In an implementation, the MAC variable NPCA_CFRAME_TXOP_REM_DUR derived from a received PPDU is:Set to 0, if the NPCA AP corresponding to the BSS of which the STA is a member has not enabled MOPLEN NPCA.Otherwise, it is set to the value in the Duration / ID field of the initial Control frame in the received PPDU at the receipt of the PHY-RXEND. indication primitive of the PPDU that contained the frame. The value of NPCA_CFRAME_TXOP_REM_DUR is reduced by the amount of time elapsed between the PHY-RXEND.indication primitive of the initial Control frame from which the value of NPCA_CFRAME_TXOP_REM_DUR was determined andDocket No.: 25-3007PCTthe PHY-RXSTART. indication primitive of the third PPDU of the frame exchange sequence identified in condition 2) above at the time of the receipt of the PHY-RXSTART. i ndication primitive of the third PPDU.

[0114] In an implementation, when an NPCA STA switches to the NPCA primary channel for NPCA operation, then the following rules apply:1) If the STA switches from the BSS primary channel to the NPCA primary channel based on meeting condition 1) described above, the STA initiates the switch at the NPCA HE switch time and shall be ready to transmit and receive frames (subject to its capabilities and operating mode) on the NPCA primary channel no later than the value of its most recently indicated NPCA switching delay after the NPCA HE switch time. The NPCA HE switch time is the point in time immediately after the reception of the HE-SIG-A / U-SIG field of the received PPDU from condition 1) above.2) If the STA switches from the BSS primary channel to the NPCA primary channel based on meeting condition 2) described above, the STA initiates the switch at the NPCA NHT switch time and shall be ready to transmit and receive frames addressed to it (subject to its capabilities and operating mode) on the NPCA primary channel no later than the value of its most recently indicated NPCA switching delay after the NPCA NHT switch time. The NPCA NHT switch time is equal to the point in time that is 3 x TSYM after the reception of the L-SIG field of the third PPDU of the received sequence of PPDUs from condition 2) above. In an example, TSYM may be a symbol interval. In an example, TSYM may be 4us in 20MHz channel spacing, 8us in 10MHz channel spacing, or 16us in 5MHz channel spacing.3) The STA uses the same EDCA parameter set and EPCS EDCA parameter set values for operation on the NPCA primary channel as it uses on the BSS primary channel.4) At each NPCA HE switch time or NPCA NHT switch time, as appropriate, if the STA is an AP or if the STA is a non-AP STA and transmission of frames that are not a response to a Trigger frame is not disabled by the MU EDCA protocol, the STA may initiate a TXOP on the NPCA primary channel with the following exceptions:a) Each time that the STA switches to the NPCA primary channel, the STA does:i) If condition 1) is met, set NPCA_CFRAME_TXOP_REM_DUR to 0, set NPCA_TIMER to the largest non-zero value of the variables NPCA_PPDU_REM_DUR, NPCA_PHY_TXOP_REM_DUR and NPCA_CFRAME_TXOP_REM_DUR, minus the switch back delay that the STA indicated in the most recently transmitted NPCA Operation Parameters field.ii) Store the existing values of the variables QSRC[AC], CW[AC] and the backoff counter for each EDCAF. ill) Set QSRC[AC] for each AC to the value of the Initial NPCA QSRC field of the NPCA Operation Parameters received from its associated NPCA AP.iv) initialize variables CWjAC] to 2 lnit_QS RC_N PCA x (CWminjAC] + 1) - 1.v) invoke the backoff procedure even if the medium for the NPCA primary channel is not busy.vi) initiate countdown of the MAC variable NPCA_TIMER in units of 1 usee.5) A first STA does not initiate a transmission on the NPCA primary channel to a second STA until the NPCA switching delay time of the second STA has elapsed since the NPCA HE switch time at the first STA if the first STA isDocket No.: 25-3007PCTswitching due to condition 1) above or since the NPCA NHT switch time at the first STA if the first STA is switching due to condition 2) above.6) The STA begins all frame exchanges on the NPCA primary channel with an initial control frame (ICF) using non-HT PPDU or non-HT duplicate PPDU format using a rate of 6 Mb / s, 12 Mb / s, or 24 Mb / s.b) For TXOPs initiated by an AP, the ICF is a BSRP Trigger frame or an MU-RTS Trigger frame except when at least one of the target non-AP STA(s) is operating in the DUO mode, in which case, the ICF may be a BSRP Trigger frame or a BSRP NTB Trigger frame but not an MU-RTS. In addition, the ICF conforms to the rules for Dynamic Unavailability Operation (DUO) mode if at least one of the target non-AP STA(s) is operating in DUO mode, to the rules for Enhanced multi-link single-radio (EMLSR) operation if at least one of the target non-AP STA(s) is affiliated with a non-AP MLD that is operating in EMLSR mode, and to the rules for Dynamic power save (DPS) operation if at least one of the target non-AP STA(s) is operating in DPS mode.c) For TXOPs initiated by a non-AP STA, the initial control frame is a BSRP NTB Trigger frame, except that if the non-AP STA is operating in the Dynamic Unavailability Operation mode (DUO), then the ICF conforms to the DUO mode rules.7) An NPCA AP that transmits a Trigger frame on the NPCA primary channel indicates RU index values that use the NPCA primary channel as the reference primary channel.8) An NPCA STA that transmits a Trigger frame on the NPCA primary channel sets the NPCA Primary Indication field to 1 in the Special User Info field, otherwise, this field is set to 0.9) The 20 MHz channels occupied by PPDUs transmitted by the STA shall meet all of the following conditions: d) include at least the NPCA primary channel.e) all be within the BSS bandwidth.f) not include any of the channels occupied by either the PPDU mentioned in condition 1) or by the third PPDU mentioned in condition 2), whichever caused the STA to switch from the BSS primary channel to the NPCA primary channel.g) not include channels that are indicated as punctured in the Disabled Subchannel Bitmap field in the EHT Operation element or in the NPCA Disabled Subchannel Bitmap field in the UHR Operation element.10) UHR ELR PPDUs, HE ERSU PPDUs, EHT MCS14 / 15 shall not be transmitted on the NPCA primary channel.11) Dynamic Subband Operation shall not be used on the NPCA primary channel.12) If TBTT for the BSS occurs while an NPCA AP is operating on the NPCA primary channel, the scheduling of the transmission of the Beacon frame and following group addressed frames shall be deferred until immediately after the AP switches back to the BSS primary channel.

[0115] In an example, an AP and associated STAs are not required to switch back to the BSS primary channel at TBTT. The group addressed frames may be buffered and delivered immediately following the next DTIM Beacon, unless explicitly specified otherwise. Further, in an example, exponential backoff may apply on the NPCA primary channel when there are failed transmissions.Docket No.: 25-3007PCT

[0116] In an implementation, an NPCA STA shall switch back to the BSS primary channel when the NPCA_TIMER expires. In an implementation, when the STA switches back to the BSS primary channel, it may:1) replace the current values of the variables QSRCjAC], C W[AC] and the backoff counter for each EDCAF with the values that it stored when it switched to the NPCA primary channel.2) resume the backoff procedure.

[0117] FIG. 9 illustrates NPCA operation which may be performed by an NPCA STA / AP in accordance with embodiments. For the purpose of illustration, NPCA operation is contrasted with single primary channel (non-NPCA) operation. As shown in FIG.9, a STA may be capable of operating over a plurality of channels. According to non-NPCA operation, the plurality of channels may include a primary channel (PCH), a first secondary channel (SCH1), a second secondary channel (SCH2), and a third secondary channel (SCH2). According to NPCA operation, the same channels may include a primary channel (PCH), a first secondary channel (SCH1), an NPCA primary channel (NPCA PCH), and a second secondary channel (SCH2). It is noted that the position of the NPCA primary channel may or may not be as shown in the example of FIG. 9. For example, the NPCA primary channel may correspond to SCH1.

[0118] As shown in FIG. 9, in non-NPCA operation, when the STA has a non-zero NAV for the PCH, the STA may not communicate via any channel of the BSS. The non-zero NAV for the PCH may be due to the STA receiving / detecting an inter-BSS PPDU (a PPDU transmitted by a STA member of an overlapping BSS) on the PCH. Instead, the STA waits for the NAV for the PCH to reach zero before contending for the PCH to transmit via the PCH. In an implementation, as shown in FIG. 10, in non-NPCA operation, a virtual carrier sense (CS) function (e.g, NAV) may be associated with only the PCH. Secondary channels may have only a physical CS function (e.g., energy detection) associated with them, which may be performed only when contending for transmission on the PCH. As such, as shown in FIG. 9, the STA may only transmit on a channel that includes the PCH (e.g, PCH, PCH+SCH1, PCH+SCH1+SCH2, PCH+SCH1+SCH2+SCH3) and only when the NAV associated with the PCH is zero (and the physical CS function indicates “channel idle” for all channels being used).

[0119] In NPCA operation, the STA may switch to the NPCA PCH when the STA detects / receives an inter-BSS PPDU on the PCH. The STA may set a NAV for the PCH based on the inter-BSS PPDU (e.g, based on a duration field of a frame carried in the inter-BSS PPDU, a transmission opportunity (TXOP) duration field of the inter-BSS PPDU, ora length field of the inter-BSS PPDU) and may switch to the NPCA PCH for a duration based on the NAV set for the PCH. After switching to the NPCA PCH, the STA may communicate via the NPCA PCH or a channel comprising the NPCA PCH. In an implementation, as shown in FIG. 10, in NPCA operation, a virtual CS function (e.g, NAV) may be associated with multiple channels (e.g, PCH and NPCA PCH). As such, as shown in FIG 9, the STA may transmit on channels that do not include the PCH but that include the NPCA PCH (e.g, NPCA PCH, NPCA PCH+SCH1, NPCA PCH+SCH2) if the NAV associated with the NPCA PCH is zero (and the physical CS indicates “channel idle” for all channels being used). In an implementation, the STA may also transmit on channels that do not include the PCH but that include the NPCA PCH (e.g, NPCA PCH, NPCA PCH+SCH1, NPCA PCH+SCH2) if the STA detects that the NPCA PCH is idle using physical CS for at least a medium synchronization duration.Docket No.: 25-3007PCT

[0120] In implementations, an NPCA STA may perform physical and / or virtual CS functions (herein referred to as CS or CCA) on multiple channels (e.g., PCH and NPCA PCH). If the PCH is busy (non-zero NAV or CCA indicates “channel busy”), the NPCA STA may use the NPCA PCH for transmission if the NPCA PCH is idle (zero NAV and CCA indicates “channel idle”).

[0121] In an implementation, an NPCA STA may support performing CS in parallel on multiple channels, including the PCH and the NPCA PCH. Such an NPCA STA may be referred to herein as a concurrent CCA NPCA STA. Because of its concurrent CCA capability, a concurrent CCA NPCA STA is capable of medium synchronization simultaneously on multiple channels (e.g., PCH and NPCA PCH). Medium synchronization on a channel (e.g., PCH or NPCA PCH) may be performed by detecting a frame that includes NAV information or by listening to the channel for at least a medium synchronization duration and finding the channel idle throughout the medium synchronization duration. In another implementation, an NPCA STA may support performing CS on a single channel at a time. Such a STA may be referred to as a non-concurrent CCA NPCA STA In an implementation, the NPCA STA may perform CS on the PCH by default. The NPCA STA may perform CS on the NPCA PCH after switching from the PCH to the NPCA PCH. In contrast to a concurrent CCA NPCA STA, a non-concurrent CCA NPCA STA may only synchronize to the NPCA PCH after the PCH is found busy. Hence, it may need to listen to the channel for at least a medium synchronization duration (if it does not receive any frame that includes NAV information) before it is able to transmit.

[0122] FIG. 11 shows an example 1100 that illustrates an NPCA operation that may be performed an NPCASTA / AP in accordance with embodiments. As shown in FIG. 11, example 1100 includes an AP and a STA associated with the AP. The AP and the STA may both support NPCA operation and may operate over a plurality of channels, including a primary channel (PCH), an NPCA primary channel (NPCA PCH), a first secondary channel (SCH1), and a second secondary channel (SCH2).

[0123] Example 1100 may begin with the AP, optionally, transmitting a frame 1102 on the PCH. Frame 1102 may indicate a medium synchronization duration for the NPCA PCH. The medium synchronization duration of a channel indicates a minimum duration that a STA must listen to the channel before the STA is able to transmit on the channel (if the STA does not receive via the channel before the end of the medium synchronization duration a frame that indicates NAV information). Frame 1102 may be a management frame, such as a beacon frame, for example.

[0124] Subsequently, while the AP and STA operate on the PCH, the AP and STA may detect overlapping BSS (OBSS) activity 1104 on the PCH. In an implementation, the AP and STA may be configured to set a NAV associated with the PCH based on detecting OBSS activity 1104 on the PCH. The AP and STA may infer a duration of OBSS activity 1104 on the PCH from a duration field of a detected frame, a transmission opportunity (TXOP) duration field of an inter-BSS PPDU comprising the detected, or a length field of the inter-BSS PPDU. The AP and STA may set their NAVs for the PCH based on a remaining duration of OBSS activity 1104 on the PCH (hereinafter, OBSS NAV duration).

[0125] The AP and the STA may then switch to the NPCA PCH for the OBSS NAV duration. In an example, the AP and the STA may switch to the NPCA PCH based on condition 1 explained above. In another example, the AP and the STA may switch to the NPCA PCH based on condition 2 explained above. In an example, the AP and the STA may switchDocket No.: 25-3007PCTto the NPCA PCH at time t1 as shown in example 1100. The AP and the STA may then communicate on the NPCA PCH. For example, the AP may transmit a frame 1106 to the STA, and the STA may transmit a frame 1108 to the AP.

[0126] The AP and STA may be configured to finish communicating on the NPCA PCH before an end of the OBSS NAV duration and to return to the PCH by the end of the OBSS NAV duration, by time t2, as shown in example 1100.

[0127] In an implementation, after switching to the NPCA PCH, the AP and STA may start a "MediumSyncDelay” timer for the medium synchronization duration of the NPCA PCH (e.g., as indicated in frame 1102). In example 1100, the AP may be a concurrent CCA STA capable of concurrent CS on both the PCH and the NPCA PCH. As such, provided that the NPCA PCH is idle, the AP may access the NPCA PCH, without waiting for expiration of the “MediumSyncDelay” timer, to transmit a frame 1106 on the NPCA PCH. In an example, the STA may be a non-concurrent CCA STA. On switching to the NPCA PCH, the STA may not be aware of whether a transmission is ongoing on the NPCA PCH. The STA may thus be configured to sense the NPCA PCH until the “MediumSyncDelay” timer expires before attempting to access the NPCA PCH. However, the STA may acquire medium synchronization on the NPCA PCH before expiration of the “MediumSyncDelay” timer if the STA receives a frame indicating NAV information on the NPCA PCH. For example, the STA may acquire medium synchronization on the NPCA PCH on receiving frame 1106 from the AP. The STA may reset the “MediumSyncDelay” timer to zero and may then proceed to access the NPCA PCH, after performing a random backoff, to transmit frame 1108 on the NPCA PCH.

[0128] FIG. 12 shows an example 1200 that illustrates another NPCA operation. As shown in FIG. 12, example 1200 includes an AP 1202 and a STA 1204. STA 1204 may be associated with AP 1202 and may belong to the same BSS as AP 1202. AP 1202 and STA 1204 may both support NPCA operation and may operate over a plurality of channels, including a primary channel (PCH), an NPCA primary channel (NPCA PCH), a first secondary channel (SCH1), and a second secondary channel (SCH2), for example.

[0129] Example 1200 may begin with STA 1204 transmitting a frame 1206 to AP 1202. Frame 1206 may indicate support of NPCA operation by STA 1204. Frame 1206 may comprise an Association Request frame, a Reassociation Request frame, or a Probe Request frame, for example. In an implementation, frame 1206 comprises a UHR Capabilities element. The UHR Capabilities element may comprise a UHR MAC Capabilities Information field. The UHR MAC Capabilities Information field may comprise an NPCA Supported field. In an example, STA 1204 may set the NPCA Supported field 1 to indicate the support of NPCA operation by STA 1204.

[0130] AP 1202 may respond to frame 1206 by transmitting a frame 1208 to STA 1204. Frame 1208 may indicate support of NPCA operation by AP 1202. Frame 1208 may comprise an Association Response frame, a Reassociation Response frame, a Probe Response frame, or a beacon frame, for example. In an implementation, frame 1208 comprises a UHR Capabilities element. The UHR Capabilities element may comprise a UHR MAC Capabilities Information field. The UHR MAC Capabilities Information field may comprise an NPCA Supported field. In an example, AP 1202 may set the NPCA Supported field to 1 to indicate the support of NPCA operation by AP 1202.

[0131] Subsequently, AP 1202 may transmit a frame 1210 indicating enabling / activating of NPCA operation in the BSS. Frame 1210 may comprise a beacon frame, for example. In an implementation, frame 1210 may indicate a time for theDocket No.: 25-3007PCTenabling / activating of NPCA operation in the BSS. For example, frame 1210 may indicate a number of beacon intervals, e.g., indicated in a Target Beacon Transmission Time (TBTT) Count field, after which NPCA operation will be enabled / activated in the BSS. In an implementation, frame 1210 may comprise a UHR Operation element. The UHR Operation element may comprise a UHR Operation Parameters field. The UHR Operation Parameters field may comprise an NPCA Operation Information Present field. In an example, AP 1202 may set the NPCA Operation Information Present field to 1 to indicate enabling / activating of NPCA operation in the BSS. On receiving frame 1210, STA 1204 may enable / activate NPCA operation. Where frame 1210 indicates a time for the enabling / activating of NPCA operation in the BSS, STA 1204 may enable / activate NPCA operation at / before the indicated time.

[0132] Subsequently, AP 1202 and STA 1204 may detect / receive an inter-BSS PPDU 1212 on the PCH. Inter-BSS PPDU 1212 is transmitted by a STA (not shown in FIG. 12) that belongs to an OBSS relative to the BSS of AP 1202 and STA 1204. Based on the enabling / activating of NPCA operation in the BSS and the detection / reception of inter-BSS PPDU 1212, AP 1202 and STA 1204 switch from the PCH to the NPCA PCH, e.g., after determining a NAV duration from inter-BSS PPDU 1212. After switching to the NPCA PCH, AP 1202 and STA 1204 may communicate via the NPCA PCH. For example, AP 1202 may transmit a frame 1214 to STA 1204. Frame 1214 may comprise a data frame, a control frame, ora management frame. Similarly, STA 1204 may transmit a frame 1216 to AP 1202. Frame 1216 may comprise a data frame, a control frame, or a management frame. AP 1202 and STA 1204 may return to the PCH at / before the end of the NAV duration determined from inter-BSS PPDU 1212.

[0133] FIG. 13 illustrates an example multi-AP network 1300. Example multi-AP network 1300 may be a multi-AP network in accordance with the Wi-Fi Alliance standard specification for multi-AP networks. As shown in FIG. 13, multi-AP network 1300 may include a multi-AP controller 1302 and a plurality of multi-AP groups (or multi-AP sets) 1304, 1306, and 1308.

[0134] Multi-AP controller 1302 may be a logical entity that implements logic for controlling the APs in multi-AP network 1300. Multi-AP controller 1302 may receive capability information and measurements from the APs and may trigger AP control commands and operations on the APs. Multi-AP controller 1302 may also provide onboarding functionality to onboard and provision APs onto multi-AP network 1300.

[0135] Multi-AP groups 1304, 1306, and 1308 may each include a plurality of APs. APs in a multi-AP group are in communication range of each other and may coordinate their transmissions and / or transmissions from their associated STAs. Coordinated transmissions may involve all or a subset of the APs in a multi-AP group. A multi-AP group may also be referred to as an AP candidate set as APs in a multi-AP group are considered candidates for a coordinated transmission initiated by an AP The APs in a multi-AP group are not required to have the same primary channel. As used herein, the primary channel for an AP refers to a default channel that the AP monitors for management frames and / or uses to transmit beacon frames. For a STA associated with an AP, the primary channel refers to the primary channel of the AP, which is advertised through the AP’s beacon frames.

[0136] In one approach, a multi-AP group may be established by a coordinator AP in a multi-AP setup phase prior to any multi-AP coordination. APs of the multi-AP group, other than the coordinator AP, may be referred to as theDocket No.: 25-3007PCTcoordinated APs. A coordinator AP may establish one or more multi-AP groups. A coordinated AP may likewise be a member of multiple multi-AP groups. A coordinator AP of a multi-AP group may be a coordinated AP of another multi-AP group, and vice versa. In another approach, a multi-AP group may be established by a network administrator manually by configuring APs as part of the multi-AP group. In yet another approach, a multi-AP group may be established in a distributed manner by APs without a central controller. In this case, an AP may advertise its multi-AP capability in a beacon or other management frame (e.g., public action frame). Other APs that receive the frame with the multi-AP capability information may perform a multi-AP setup with the AP that advertised the multi-AP capability.

[0137] In one approach, one of the APs in a multi-AP group may be designated as a master AP. The designation of the master AP may be done by AP controller 1302 or by the APs of the multi-AP group. The master AP of a multi-AP group may be fixed or may change over time between the APs of the multi-AP group. An AP that is not the master AP of the multi-AP group is known as a slave AP.

[0138] In one approach, APs in a multi-AP group may perform coordinated transmissions together. One aspect of coordination may include coordination to perform coordinated transmissions within the multi-AP group. As used herein, a coordinated transmission, also referred to as a multi-AP transmission, is a transmission event in which multiple APs (of a multi-AP group ora multi-AP network) transmit in a coordinated manner over a time period. Coordinated transmissions may involve simultaneous transmissions of a plurality of APs in a multi-AP group. The time period of simultaneous AP transmission may be a continuous period. The multi-AP transmission may use different transmission techniques, such as Coordinated OFDMA (COFDMA), Coordinated Spatial Reuse (CSR), Joint Transmission or Reception (JT / JR), Coordinated Beamforming (CBF), and CTDMA, or a combination of two or more of the aforementioned techniques.

[0139] Multi-AP transmissions may be enabled by the AP controller and / or by the master AP of the multi-AP group. In one approach, the AP controller and / or the master AP may control time and / or frequency sharing in a transmission opportunity (TXOP). For example, when one of the APs (e.g., the master AP) in the multi-AP group obtains a TXOP, the AP controller and / or the master AP may control how time / frequency resources of the TXOP are to be shared with other APs of the multi-AP group. In an implementation, the AP of the multi-AP group that obtains a TXOP becomes the master AP of the multi-AP group. The master AP may then share a portion of its obtained TXOP (which may be the entire TXOP) with one or more other APs of the multi-AP group.

[0140] Different multi-AP transmission schemes may be suitable for different use cases in terms of privacy protection, including whether transmitted data may be shared with other BSSs in the multi-AP group. For example, some multi-AP transmission schemes, such as CSR, CDTMA, coordinated frequency division multiple access (CFDMA), COFDMA, and CBF, enable a master AP to coordinate slave APs by sharing control information among APs, without requiring the sharing of user data among APs. The control information may include BSS information of APs, link quality information of channels between each AP and its associated STAs, and information related to resources to be used to achieve multiplexing in power, time, frequency, or special domains for multi-AP transmission. The control information exchanged among a master AP and slave APs may be used for interference avoidance or nulling to avoid or null co-channel interference introduced to neighboring BSSs in a multi-AP network. Interference avoidance or interference nulling requires that data transmissionsDocket No.: 25-3007PCTbetween an AP and STAs are only within the same BSS. In other words, each AP transmits or receives data frames to or from its associated STAs, while each STA receives or transmits data frames to or from its associating AP.

[0141] By contrast, other multi-AP transmission schemes may enable a master AP to coordinate slave APs by sharing both control information and user data among APs in a multi-AP group. Control information may include BSS information related to APs and link quality information of channels between each AP and its associated STAs. By having user data exchanged over backhaul, the master AP and slave APs may perform data transmissions jointly to achieve spatial diversity, e.g., using distributed Ml MO, for example, joint transmission (JT) for downlink transmissions and joint reception (JR) for uplink transmissions. The data transmissions between APs and STAs may include transmissions within the same BSS and / or across different BSSs. In other words, an AP may transmit or receive data frames to or from its associated STAs as well STAs associated with other APs participating in multi-AP transmission. Similarly, a STA may transmit or receive data frames to or from multiple APs.

[0142] Different multi-AP transmission schemes may be suitable for different use cases in terms of signal reception levels at STAs or APs within a multi-AP group. For example, CBF and JT / JR require that each STA involved in a multi-AP transmission be located within a common area of signal coverage of the APs involved in the multi-AP transmission. Generally, CBF may be suitable when a receiving STA suffers from potential interference from other APs in the multi-AP group. By using channel related information such as channel state information (CSI), channel quality indication (CQI), or compressed beamforming (BF) feedback exchanged among APs, an AP may pre-code a signal to be transmitted to form a beam that increases power toward a target STA while reducing the power that interferes with a STA associated with a neighboring AP. Use cases of JT / JR may require a sufficient received signal power at receiving STAs for JT and a sufficient received signal power at receiving APs for JR. By contrast, CSR may perform multi-AP transmission in an interference coordination manner. The received signal power at a STA associated with an AP transmitting data may be required to be much higher than the received interference power.

[0143] Different multi-AP transmission schemes may require different synchronization levels and may operate with or without a backhaul between a master AP and slave APs in a multi-AP group. For example, CSR may require PPDU-level synchronization, whereas CBF may require symbol-level synchronization. On the other hand, JT / JR may require tight time / frequency / phase-level synchronization as well as a backhaul for data sharing between APs in the multi-AP group.

[0144] Different multi-AP transmission schemes may have different complexity levels with regard to coordination between a master AP and slave APs in a multi-AP group. For example, JT / JR may require very high complexity due to both CSI and user data being shared between APs. CBF may require medium complexity due to the sharing of CSI. CFDMA, COFDMA and CTDMA may require medium or relatively low complexity due to the CSI and time / frequency resources to be shared between APs. CSR may require low complexity as the amount of information related to spatial reuse and traffic that needs to be exchanged between APs may be low.

[0145] A multi-AP group may adopt a static multi-AP operation including a static multi-AP transmission scheme. A multi-AP network may also be dynamic due to various reasons. For example, a STA may join or leave the multi-AP network, a STA may switch to a power save mode, or an AP or a STA may change its location. Such changes may leadDocket No.: 25-3007PCTto changes in the conditions underlying the selection of the multi-AP transmission scheme and may cause certain requirements (e.g., synchronization, backhaul, coordination, etc.) for the multi-AP transmission scheme to be lost. This results in an inferior quality of transmissions in the multi-AP network.

[0146] FIG. 14 illustrates an example 1400 of a multi-AP negotiation procedure including a multi-AP NPCA negotiation phase. As shown in FIG. 14, example 1400 may include an AP 1402, an AP 1404, and an AP 1406. In an example, the multi-AP negotiation procedure may begin with a multi-AP discovery phase, in which AP 1402 transmits a frame 1408 to APs 1404 and 1406. In an example, frame 1408 polls APs 1404 and 1406 regarding joining a multi-AP group with AP 1402. In an example, frame 1408 may further indicate that NPCA operation parameters will be negotiated in the multi-AP group. Frame 1408 may be a broadcast or multicast frame. APs 1404 and 1406 respond to frame 1408 by transmitting to AP 1402 frame 1410 and frame 1412 respectively. Frames 1410 and 1412 indicate acceptance or rejection by APs 1404 and 1406 respectively of joining the multi-AP group with AP 1402. In an example, AP 1402 may be referred to as coordinating AP, and APs 1404 and 1406 may be referred to as coordinated APs.

[0147] Subsequently, the multi-AP negotiation procedure may proceed to the multi-AP NPCA negotiation phase, in which AP 1402 negotiates NPCA operation parameters with APs 1404 and 1406. In an implementation, the objective of the multi-AP NPCA negotiation phase is to reduce interference among APs 1402, 1404, and 1406 during NPCA operation by, for example, ensuring that APs 1402, 1404, and 1406 operate on non-overlapping NPCA PCH channels. The multi-AP NPCA negotiation phase may be performed using a variety of ways. In an example, AP 1402 may determine a first NPCA parameter set for itself. The first NPCA parameter set may include a first channel location / number and a first bandwidth for a first NPCA PCH to be used by AP 1402. The first NPCA PCH may include a 20 MHz channel corresponding to the first channel location / number and zero or more adjacent 20 MHz channels up to the first bandwidth for the first NPCA PCH (the one or more adjacent 20 MHz channels may be located at either side in frequency relative to the 20 MHz channel corresponding to the first channel location / number, provided that the first NPCA PCH does not overlap with the PCH). For example, if the first bandwidth is 40 MHz, the first NPCA PCH may include the 20 MHz channel corresponding to the first channel location / number and zero or one 20 MHz channel adjacent to the 20 MHz channel corresponding to the first channel location / number.

[0148] Subsequently, as shown, AP 1402 may transmit a frame 1414 to AP 1404 indicating a second NPCA parameter set for AP 1404. The second NPCA parameter set may include a second channel location / number and a second bandwidth for a second NPCA PCH to be used by AP 1404. In an implementation, AP 1402 may determine the second channel location / number of the second NPCA PCH to be different than the first channel location / number of first NCPA PCH used by AP 1402. Additionally, AP 1402 may determine the second bandwidth of the second NPCA PCH to avoid or reduce overlap between the second NPCA PCH and the first NPCA PCH. Upon receiving frame 1414, AP 1404 may transmit a frame 1416 to AP 1402 indicating acceptance or rejection of the second NPCA parameter set or indicating a modified second NPCA parameter set. The modified second NPCA parameter set may include a modified second channel location / number and / or a modified second bandwidth. The modified second channel location / number may be the same as or different than the second channel location / number. The modified second bandwidth may be the same as or differentDocket No.: 25-3007PCTthan the second bandwidth. APs 1402 and 1404 may exchange additional frames (not shown in FIG. 14) until agreement is reached on the second NPCA parameter set for AP 1404. In example 1400, it is assumed that AP 1404 accepts the second NPCA parameter set indicated in frame 1414.

[0149] After agreeing on the second NPCA parameter set with AP 1404, AP 1402 may transmit a frame 1418 to AP 1406 indicating a third NPCA parameter set. The third NPCA parameter set may include a third channel location / number and a third bandwidth for a third NPCA PCH to be used by AP 1406. In an implementation, AP 1402 may determine the third channel location / number of the third NPCA PCH to be different than the first channel location / number of the first NCPA PCH used by AP 1402 and the second channel location / number of the second NPCA PCH used by AP 1404. Additionally, AP 1402 may determine the third bandwidth of the third NPCA PCH to avoid or reduce overlap between the third NPCA PCH and both the first NPCA PCH and the second NPCA PCH. Upon receiving frame 1418, AP 1406 may transmit a frame 1420 to AP 1402 indicating acceptance or rejection of the third NPCA parameter or indicating a modified NPCA parameter set. APs 1402 and 1406 may exchange additional frames (not shown in FIG. 14) until agreement is reached on the third NPCA parameter set for AP 1406. In example 1400, it is assumed that AP 1406 accepts the third NPCA parameter set indicated in frame 1418. Thus, the multi-AP NPCA negotiation phase ends with frame 1420, and APs 1402, 1404, and 1406 may begin using the negotiated NPCA parameter sets.

[0150] While the multi-AP negotiation procedure illustrated in FIG. 14 may allow APs to coordinate NPCA operation to avoid / reduce interference during NPCA operation, the procedure is based on a static view of the network environment as determined at the time of the negotiation. As mentioned above, the multi-AP negotiation procedure is performed at the time of formation of a multi-AP group comprising the APs. The static view based on which the multi-AP NPCA negotiation is performed thus may not reflect and may be ill-suited for changing traffic / load conditions after multi-AP group formation. FIG. 15 shows an example 1500 that illustrates a problem that may arise with a static multi-AP NPCA configuration. As shown in FIG. 15, example 1500 includes an AP 1502 and an AP 1504. APs 1502 and 1504 operate on the same PCH, PCH 1506. Additionally, it is assumed that, before the beginning of example 1500, APs 1502 and 1504 performed a multi-AP negotiation procedure as illustrated in FIG. 14. Specifically, APs 1502 and 1504 performed a multi-AP NPCA negotiation phase that resulted in AP 1502 being assigned a channel "NPCA PCH 1508” having a first bandwidth for a first NPCA PCH used byAP 1502 and AP 1504 being assigned a channel “NPCA PCH 1510” having a second bandwidth for a second NPCA PCH used by AP 1504. As shown, NPCA PCH 1508 and NPCA PCH 1510 are adjacent to one another and the first bandwidth is equal to the second bandwidth. Example 1500 begins with APs 1502 and 1504 operating on PCH 1506.

[0151] Ata time t1, low latency (LL) traffic arrives at AP 1502 for transmission byAP 1502. The LL traffic may be for transmission to a STA associated with AP 1502. The LL traffic may have a transmission deadline corresponding to a time t4. AP 1502 may be configured to contend for PCH 1506 to transmit the LL traffic. However, in example 1500, AP 1502 detectsan OBSS PPDU 1512 on PCH 1506. Based on NPCA operation being enabled at AP 1502, AP 1502 sets a NAV 1514 for PCH 1506 based on OBSS PPDU 1512 and switches from PCH 1506 to NPCA PCH 1508 at a time t3. AP 1502 may be configured to return to PCH 1506 at / before expiration of NAV 1514 at a time t5. After switching to NPCA PCHDocket No.: 25-3007PCT1508, AP 1502 may determine that the first bandwidth of NPCA PCH 1508 is not sufficient to transmit the LL traffic by its transmission deadline, t4. Accordingly, AP 1502 may determine not to transmit the LL traffic via NPCA PCH 1508. Further, based on NAV 1514 extending beyond the transmission deadline, t4, AP 1502 may determine to discard the LL traffic altogether since AP 1502 may not transmit the LL traffic by the transmission deadline, t4, after returning to PCH 1506 at time t5.

[0152] At a time t2, non-LL traffic arrives at AP 1504 for transmission by AP 1504. The non-LL traffic may be for transmission to a STA associated with AP 1504. The non-LL traffic may have a transmission deadline corresponding to a time t6. As shown, time t6 is significantly later than the transmission deadline, t4, of the LL traffic of AP and is after the expiration time, t5, of NAV 1514. AP 1504 may be configured to contend for PCH 1506 to transmit the non-LL traffic. However, AP 1504 also detects OBSS PPDU 1512 on PCH 1506. Based on NPCA operation being enabled at AP 1504, AP 1504 sets NAV 1514 for PCH 1506 based on OBSS PPDU 1512 and switches from PCH 1506 to NPCA PCH 1510 at time t3. After switching to NPCA PCH 1510, AP 1504 proceeds to transmit a frame 1516 comprising the non-LL traffic via NPCA PCH 1510. As the second bandwidth of NPCA PCH 1510 is sufficiently large for transmission of the non-LL traffic, AP 1504 may finish transmitting frame 1516 much earlier than time t5, at which AP 1504 returns to PCH 1506.

[0153] As example 1500 illustrates, static multi-AP NPCA configuration may be inefficient when traffic / load conditions change at APs 1502 and 1504. Specifically, in example 1500, the allocation of equal bandwidths to NPCA PCH 1508 and NPCA PCH 1510 resulted in AP 1502 being unable to transmit its LL traffic after switching to NPCA PCH 1508 and in AP 1504 under-utilizing NPCA PCH 1510 after transmitting its non-LL traffic via NPCA PCH 1510.

[0154] Embodiments of the present disclosure, as further described below, address the above-discussed problem of existing technologies. In an aspect, a first AP transmits to a second AP a first frame indicating a first NPCA parameter set for the second AP. The first NPCA parameter set indicates at least one of: a first channel location of a first NPCA PCH of the second AP; and a first channel bandwidth of the first NPCA PCH. The first AP receives from the second AP a second frame indicating acceptance of the first NPCA parameter set by the second AP. In an embodiment, the first frame and the second frame are part of a multi-AP NPCA negotiation phase comprising the first AP and second AP. In an embodiment, the first AP and the second AP form a multi-AP group. The first AP may be coordinating AP of the multi-AP group, and the second AP may be a coordinated AP of the multi-AP group. After receiving the second frame, the first AP transmits to the second AP a third frame indicating a second NPCA parameter set for the second AP. The second NPCA parameter set indicates at least one of: a second channel location of the first NPCA PCH; and a second bandwidth of the first NPCA PCH. The second channel location may be different than the first channel location and / or the second bandwidth may be different than the first bandwidth In an embodiment, the third frame is not part of a multi-AP NPCA negotiation phase. As such, the first AP may dynamically change the NPCA parameter set used by the second AP, e.g ., after the multi-AP negotiation phase. In an embodiment, the third frame further indicates a time period during which the second AP uses the second NPCA parameter set instead of the first NPCA parameter set. The second AP may thus return to using the first NPCA parameter set after the time period.Docket No.: 25-3007PCT

[0155] FIG. 16 illustrates an example 1600 of procedure according to an embodiment. The procedure illustrated in FIG.16 may be used to enable coordinated NPCA (Co-NPCA) operation, according to which an AP may adjust the NPCA parameter set of another AP, e.g., after a multi-AP NPCA negotiation phase between the two APs. Example 1600 is provided for the purpose of illustration only and is not limiting of embodiments of the present disclosure. As shown in FIG.16, example 1600 may include an AP 1602 and an AP 1604. In an embodiment, each of AP 1602 and AP 1604 maybe a multi-link device (MLD), that is a device capable of operating over multiple links as defined by the IEEE 802.11 standard. In an embodiment, APs 1602 and 1604 may form a multi-AP group. AP 1602 may be coordinating AP of the multi-AP group, and AP 1604 may be a coordinated AP of the multi-AP group. In an embodiment, AP 1602 and AP 1604 may be configured to operate on the same PCH 1606 and on the same NPCA PCH channels by default and may support reconfiguration of their respective NPCA PCH channels during a multi-AP NPCA negotiation phase as described in FIG.14 above. Hereinafter, the NPCA PCH used by AP 1602 is referred to as the first NPCA PCH, and the NPC PCH used by AP 1604 is referred to as the second NPCA PCH

[0156] Example 1600 may begin with AP 1602 transmitting a first frame (not shown in FIG. 16) to AP 1604 initiating a multi-AP negotiation procedure. In an embodiment, the first frame may comprise a request to form a multi-AP group. The first frame may be a broadcast or multicast frame. In an embodiment, the first frame may be a management frame that advertises multi-AP coordination capabilities (and associated parameters) of AP 1602. In an embodiment, the first frame may indicate a request by AP 1602 to initiate a discovery phase for Co-NPCA operation. During the discovery phase, AP 1602 discovers AP(s) of the multi-AP group that accept to participate in Co-NPCA operation. In an embodiment, AP 1602 may receive a response to the first frame from AP(s) of the multi-AP group indicating acceptance or rejection of participation in Co- NPCA operation. In an embodiment, in accordance with Co-NPCA, multiple APs may coordinate NPCA operation, including NPCA operation parameters, among each other.

[0157] Upon receiving the first frame, AP 1604 may transmit a second frame to AP 1602. In an embodiment, the second frame indicates acceptance or rejection by AP 1604 of the request, in the first frame, to form a multi-AP group. Alternatively, or additionally, the second frame indicates acceptance or rejection of the request, in the first frame, to participate in Co-NPCA operation. In an embodiment, the second frame may be a management frame.

[0158] Example 1600 may also include APs 1602 and 1604 performing a multi-AP NPCA negotiation phase (not shown in FIG. 16) of the multi-AP negotiation procedure. As described in FIG. 14, the multi-AP negotiation phase may include a frame exchange between APs 1602 and 1604 to agree on a second NPCA parameter setfor AP 1604. The second NPCA parameter set may include a second channel location / number and a second bandwidth for the second NPCA PCH to be used by AP 1604. AP 1602 may determine the second NPCA parameter set based on a first NPCA parameter set used by AP 1602. The first NPCA parameter set may include a first channel location / number and a first bandwidth for the first NPCA PCH used byAP 1602. In an implementation, AP 1602 may determine the second channel location / number of the second NPCA PCH to be different than the first channel location / number of the first NCPA PCH used by AP 1602. Additionally, AP 1602 may determine the second bandwidth of the second N PCA PC H to avoid or reduce overlap between the second NPCA PCH and the first NPCA PCH.Docket No.: 25-3007PCT

[0159] In accordance with the procedure illustrated in FIG. 16, after an AP performs and finishes a multi-NPCA negotiation phase with another AP, the AP may initiate / request / recommend a modification of the NPCA parameter set of the other AP. The AP may be the coordinating AP of a multi-AP group comprising the other AP. The AP may initiate / request / recommend the modification based on traffic and / or interference conditions, for example. The modification may include a modification of the channel location / number and / or the bandwidth of the NPCA PCH channel of the other AP. In an embodiment, the AP may request / recommend that the other AP modify its NPCA parameter set to a requested / recommended NPCA parameter set. The other AP may accept / reject the requested / recommended NPCA parameter set or may propose a modified requested / recommended NPCA parameter set. In another embodiment, the AP may instruct the other AP to modify its NPCA parameter to an indicated NPCA parameter set. The other AP may modify its NPCA parameter to the indicated NPCA parameter set based on the instruction. In a further embodiment, the AP may indicate a time period during which the other AP should use the requested / recommended / indicated NPCA parameter set. The other AP may return to its initial NPCA parameter after the time period has elapsed. The other AP may accept or reject the time period or may propose a modified time period.

[0160] In another embodiment, an AP may initiate / request / recommend a modification of its own NPCA parameter set. The AP may be a coordinated AP of a multi-AP group. The AP may initiate / request / recommend the modification based on traffic and / or interference conditions, for example. The modification may include a modification of the channel location / number and / or the bandwidth of the NPCA PCH channel of the AP. In an embodiment, the AP may request / recommend to modify its NPCA parameter set to a requested / recommended NPCA parameter set. Another AP, which may be the coordinating AP of the multi-AP group, may accept / reject the requested / recommended NPCA parameter set or may propose a modified requested / recommended NPCA parameter set. In another embodiment, the AP may inform the other AP that the AP modified its NPCA parameter to an indicated NPCA parameter set. That is, the AP may not require approval by the other AP to modify its NPCA parameter set to the indicated NPCA parameter set. In a further embodiment, the AP may indicate a time period during which the AP requests to use the requested / recommended NPCA parameter set or is going to use the indicated NPCA parameter set. The AP may return to its initial NPCA parameter after the time period has elapsed. The other AP may accept or reject the time period or may propose a modified time period.

[0161] For illustration, in an example, it is assumed that, at the beginning of example 1600, the first NPCA PCH (used by AP 1602) corresponds to a channel “NPCA PCH 1608” and that the second NPCA PCH (used by AP 1604) corresponds to a channel “NPCA PCH 1610”. NPCA PCH 1608 / 1610 may be associated with a channel location / number, e.g., corresponding to the channel location / number of a lowest frequency 20 MHz subchannel encompassed by NPCA PCH 1608 / 1610. NPCA PCH 1608 / 1610 may have a bandwidth corresponding to the bandwidth of one or more 20 MHz channels encompassed by NPCA PCH 1608 / 1610. As shown, it is further assumed that NPCA PCH 1608 and NPCA PCH 1610 may be adjacent to one another.

[0162] In an example, low latency (LL) traffic may arrive at a time t1 at AP 1602. The LL traffic may be for transmission to a STA associated with AP 1602. The LL traffic may have a transmission deadline corresponding to a time t4. In anDocket No.: 25-3007PCTexample, based on the arrival of the LL traffic, AP 1602 may determine to initiate modification of the first NPCA parameter set used by AP 1602 and / or the second NPCA parameter set used by AP 1604. For example, AP 1602 may determine that transmission of the LL traffic by the transmission deadline may require a bandwidth larger than the maximum bandwidth supported by NPCA PCH 1608. As such, to avoid delay to the LL traffic in the event that AP 1602 must transmit the LL traffic via NPCA PCH 1608, AP 1602 may determine to modify the first NPCA parameter set and / or the second NPCA parameter set to allow for a greater bandwidth for the first NPCA PCH used by AP 1602.

[0163] In accordance with an embodiment, AP 1602 may transmit to AP 1604 a frame 1614 indicating a third NPCA parameter set for AP 1604. The third NPCA parameter set may indicate at least one of: a third channel location / number for the second NPCA PCH and / or a third bandwidth for the second NPCA PCH. The third channel location / number may be the same as or different than the second channel location / number. The third bandwidth may be the same or different than the second bandwidth. The third bandwidth may correspond to a maximum bandwidth of the second NPCA PCH. The third bandwidth may comprise the bandwidth of the channel indicated by the second channel location / number and zero or more (e.g., 20 MHz) channels, within a bandwidth of a basic service set (BSS) of the AP 1604, adjacent to the channel indicated by the second channel location / number. In an embodiment, frame 1614 requests / recommends that AP 1604 use the third NPCA parameter set. In another embodiment, frame 1614 instructs AP 1604 to use the third NPCA parameter set.

[0164] In an embodiment, frame 1614 further indicates a first time period 1626 during which AP 1604 uses (or should use) the third NPCA parameter set (instead of the second NPCA parameter set). Frame 1614 may indicate a starting time, a duration, and / or an endtime of first time period 1626. In an embodiment, frame 1614 requests / recommends that AP 1604 use the third NPCA parameter set during first time period 1626. In another embodiment, frame 1614 instructs AP 1604 to use the third NPCA parameter set during first time period 1626. In an embodiment, AP 1602 determines first time period 1626 based on expected traffic characteristics of the LL traffic.

[0165] In accordance with an embodiment, AP 1604 may respond to frame 1614 by transmitting a frame 1616 to AP 1602. In an embodiment, e.g., where frame 1614 requests / recommends that AP 1604 use the third NPCA parameter set, frame 1616 may indicate acceptance or rejection of the request / recommendation. Alternatively, frame 1616 may indicate / propose a fourth NPCA parameter set, different than the third NPCA parameter set, to be used by AP 1604 and / or a second time period, different than first time period 1626, during which AP 1604 uses the third / fourth NPCA parameter set. The fourth NPCA parameter set may indicate a fourth channel location / number and / or a fourth bandwidth for the second NPCA PCH. The fourth channel location / number may be the same as or different than the third channel location / number. The fourth bandwidth may be the same as or different than the third bandwidth. AP 1602 may respond to frame 1616 to indicate acceptance or rejection of the fourth NPCA parameter set. In another embodiment, e.g., where frame 1614 instructs AP 1604 to use the third NPCA parameter set, frame 1616 may acknowledge the instruction and / or may indicate that AP 1604 has updated the NPCA parameter set for the second NPCA PCH.

[0166] In an embodiment, AP 1602 and 1604 may pre-negotiate a plurality of NPCA parameter set for AP 1602 and / or a plurality of NPCA parameter sets for AP 1604. The third NPCA parameter set indicated in frame 1614 may correspondDocket No.: 25-3007PCTto a selected NPCA parameter set of the plurality of NPCA parameter sets pre-negotiated for AP 1604. In an implementation, frame 1614 may indicate an identifier of the selected NPCA parameter set. As the third NPCA parameter set is pre-negotiated, AP 1604 may simply acknowledge frame 1614 in frame 1616.

[0167] In example 1600, to accommodate a larger NPCA PCH bandwidth for its LL traffic, AP 1602 determines to increase the bandwidth of the first NPCA PCH that AP 1602 uses. For example, AP 1602 may determine to increase the bandwidth of the first NCPA PCH to encompass the second bandwidth associated with the second NPCA PCH used by AP 1604. For example, AP 1602 may increase the bandwidth of the first NPCA PCH to include the bandwidths of NPCA PCH 1608 and NPCA PCH 1610. In example 1600, AP 1602 may determine not to change the channel location / number associated with the first NPCA PCH. In conjunction, AP 1602 determines to move the second NPCA PCH used by AP 1604. For example, AP 1602 may determine to move the second NPCA PCH to an NPCA PCH 1612, instead of NPCA PCH 1610. In example 1600, AP 1602 may determine not to change the bandwidth of the second NPCA PCH. In an example, AP 1602 may also determine first time period 1626 during which AP 1604 should use NPCA PCH 1612, instead of NPCA PCH 1610, for the second NPCA PCH. AP 1602 indicates the modified location of the second NPCA PCH using the third NPCA parameter set indicated in frame 1614, and more specifically by indicating the channel location / number associated with NPCA PCH 1612 as the third channel location / number. In example 1600, it is assumed that AP 1604 accepts the requested NPCA parameter set change in frame 1616 and begins using the third NPCA parameter set after receiving frame 1614.

[0168] Subsequently, AP 1602 may begin transmitting the LL traffic. In an example, AP 1602 may transmit a portion of the LL traffic on the PCH (not shown in FIG. 16). In another example, before starting transmitting the LL traffic via the PCH or before finishing transmitting the LL traffic, an OBSS PPDU 1618 may gain access to the PCH. As mentioned above, an OBSS PPDU is a PPDU transmitted by a STA (AP / non-AP) that is a member of an OBSS relative to the BSS of AP 1602 / 1604 or the ESS of APs 1602 and 1604. On detecting / receiving OBSS PPDU 1618 on the PCH, AP 1602 andAP 1602 each sets a NAV 1620 for the PCH based on OBSS PPDU 1618 and switches to its respective NPCA PCH. Specifically, AP 1602 switches to the first NPCA PCH corresponding to NPCA PCH 1608 (and having a bandwidth encompassing the bandwidths of NPCA PCH 1608 and NPCA PCH 1610) and AP 1604 switches to the second NPCA PCH corresponding to NPCA PCH 1612. AP 1602 then gains access to the first NPCA PCH and transmits a frame 1624 via the first NPCA PCH. As shown, with the second NPCA PCH used byAP 1604 moved to NPCA PCH 1612, AP 1602 may use the entire modified bandwidth of the first NPCA PCH (encompassing the bandwidths of NPCA PCH 1608 and NPCA PCH 1610), without risking interference byAP 1604, to transmit frame 1624. As such, AP 1602 is able to transmit the entirety of the LL traffic by the transmission deadline t4 using frame 1624.

[0169] In an example, after switching to the second NPCA PCH corresponding to NPCA PCH 1612, AP 1604 has traffic arrive for transmission. AP 1604 gains access to the second NPCA PCH and transmits a frame 1622 with the traffic via the second NPCA PCH. As the second NPCA PCH was moved to NPCA PCH 1612, AP 1604 may not block AP 1602 from gaining access to the entire modified bandwidth of the first NPCA PCH (encompassing the bandwidths of NPCA PCH 1608 and NPCA PCH 1610).Docket No.: 25-3007PCT

[0170] AP 1602 and AP 1604 may return to the PCH at / before expiration of NAV 1620 set based on OBSS PPDU 1618. At expiration of first time period 1626, AP 1604 may return to using the second NPCA parameter set negotiated with AP 1602 during the multi-AP NPCA negotiation phase. It is noted that first time period 1626 may expire before expiration of NAV 1620. As such, AP 1604 may return to using the second NPCA parameter set during NAV 1620.

[0171] In another embodiment, not shown in FIG. 16, the exchange of frames 1614 and 1616 may occur via the NPCA PCH. For example, AP 1602 and 1604 may be operating using the same NPCA PCH. After switching to the NPCA PCH based on OBSS PPDU 1618, APs 1602 and 1604 may exchange frames 1614 and 1616 via the NPCA PCH to begin using different NPCA parameter sets as discussed above. APs 1602 and 1604 may then switch to their respective NPCA PCHs during NAV 1620.

[0172] FIG. 17 illustrates an example 1700 of another procedure according to an embodiment. The procedure illustrated in FIG. 17 may be used to enable coordinated NPCA (Co-NPCA) operation, according to which an AP may adjust the NPCA parameter set of another AP, e.g., after a multi-AP NPCA negotiation phase between the two APs. Example 1700 is provided for the purpose of illustration only and is not limiting of embodiments of the present disclosure. As shown in FIG. 17, example 1700 may include an AP 1702 andan AP 1704. In an embodiment, each of AP 1702 and AP 1704 may be an MLD. In an embodiment, APs 1702 and 1704 may form a multi-AP group. AP 1702 may be coordinating AP of the multi-AP group, and AP 1704 may be a coordinated AP of the multi-AP group. In an example, AP 1702 may be an embodiment of AP 1602, and AP 1704 may bean embodiment of AP 1604.

[0173] Example 1700 may begin with APs 1702 and 1704 performing a multi-AP NPCA negotiation phase (not shown in FIG. 17), as described with reference to FIGs. 14 and 16 above, to determine a first NPCA parameter set used byAP 1702 and a second NPCA parameter set used by AP 1704. Based on the first and second NPCA parameter sets, AP 1702 uses a first NPCA PCH having a first channel location / number and a first bandwidth and AP 1704 uses a second NPCA PCH having a second channel location / number and a second bandwidth.

[0174] In an embodiment, example 1700 may further include AP 1702 transmitting a frame 1706 to AP 1704 indicating a third NPCA parameter set for AP 1704. The third NPCA parameter set may indicate at least one of: a third channel location / number for the second NPCA PCH and / or a third bandwidth for the second NPCA PCH. The third channel location / number may be the same as or different than the second channel location / number. The third bandwidth may be the same or different than the second bandwidth. The third bandwidth may correspond to a maximum bandwidth of the second NPCA PCH. As described with reference to FIG. 16 above, frame 1706 may request / recommend that AP 1704 use the third NPCA parameter set or may instruct AP 1704 to use the third NPCA parameter set.

[0175] In an embodiment, frame 1706 may further indicate a first time period 1710 during which AP 1704 is to use the third NPCA parameter set. Frame 1706 may indicate a start time 1712 and / or an end time 1714 of first time period 1710. Alternatively, or additionally, frame 1706 may further indicate a second time period 1716 during which AP 1704 is to use the second NPCAparameter set (or a default NPCA parameterpre-configured within AP 1704). Frame 1706 may indicate a start time 1718 and / or an end time 1720 of second time period 1716.Docket No.: 25-3007PCT

[0176] In an embodiment, frame 1706 indicates a periodic NPCA operation schedule for AP 1704. The periodic NPCA operation schedule may indicate / comprise first time period 1710 and / or second time period 1716. In an embodiment, the periodic NPCA operation schedule indicates a first periodicity of first time period 1710 and / or a second periodicity of second time period 1716. For example, the periodic NPCA operation schedule may indicate a time interval 1722 between successive instances of start time 1712 of first time period 1710.

[0177] Upon receiving frame 1706, AP 1704 may transmit a frame 1708 to indicate acceptance or rejection of the periodic NPCA operation schedule. Alternatively, AP 1704 may propose an alternative periodic NPCA operation schedule for itself in frame 1708. AP 1702 may accept or reject the alternative periodic NPCA operation schedule for AP 1704.

[0178] FIG. 18 illustrates an example 1800 of another procedure according to an embodiment. The procedure illustrated in FIG. 18 may be used to enable coordinated NPCA (Co-NPCA) operation, according to which an AP may adjust the NPCA parameter set of another AP, e.g., after a multi-AP NPCA negotiation phase between the two APs. Example 1800 is provided for the purpose of illustration only and is not limiting of embodiments of the present disclosure. As shown in FIG. 18, example 1800 may include an AP 1802 and an AP 1804. APs 1802 and 1804 operate on the same PCH, PCH 1806. In an embodiment, each of AP 1802 and AP 1804 may be an MLD. In an embodiment, APs 1802 and 1804 may form a multi-AP group. AP 1802 may be coordinating AP of the multi-AP group, and AP 1804 may be a coordinated AP of the multi-AP group. In an example, AP 1802 maybe an embodiment of AP 1602, and AP 1804 may be an embodiment of AP 1604.

[0179] Example 1800 begins with NPCA operation enabled at both APs 1802 and 1804 and with AP 1802 using a first NPCA parameter set and AP 1804 using a second NPCA parameter set for NPCA operation. For example, before example 1800, APs 1802 and 1804 may have performed a multi-AP NPCA negotiation phase that resulted in AP 1802 being assigned a channel "NPCA PCH 1808” having a first bandwidth for a first NPCA PCH used by AP 1802 and AP 1804 being assigned a channel “NPCA PCH 1810” having a second bandwidth for a second NPCA PCH used by AP 1804.

[0180] While APs 1802 and 1804 operate on PCH 1806, APs 1802 and 1804 detect an OBSS PPDU 1814 on PCH 1806. On detecting OBSS PPDU 1814, APs 1802 and 1804 set a NAV 1820 for PCH 1806 and switch to their respective NPCAPCHsata time t1. Specifically, AP 1802 switches to NPCA PCH 1808, andAP 1804 switches to NPCA PCH 1810. In an example, after switching to NPCA PCH 1808, AP 1802 may transmit a frame 1816 with buffered traffic via NPCA PCH 1808. In an example, AP 1802 may use the entirety of the first bandwidth of NPCA PCH 1808 to transmit frame 1816. In an example, after switching to NPCA PCH 1810, AP 1804 may have traffic arrive for transmission and may proceed to transmit a frame 1816 with the traffic via NPCA PCH 1810. In an example, AP 1804 may use only a portion of the second bandwidth of NPCA PCH 1810 to transmit frame 1818. APs 1802 and 1804 return to PCH 1806 at / before expiration of NAV 1820 at a time t2.

[0181] Subsequently, at a time t3, traffic arrives at AP 1802 for transmission by AP 1802. With AP 1802 operating on the PCH, AP 1802, AP 1802 initiates a TXOP on PCH 1806, at a time t4, by transmitting a frame 1822 to AP 1804. Frame 1822 may be an embodiment of frame 1614 described above. In an embodiment, frame 1822 comprises an initial controlDocket No.: 25-3007PCTframe (ICF). In an embodiment, the ICF may comprise a request-to-send (RTS) frame or a clear-to-send (CTS)-to-self frame. In an embodiment, frame 1822 indicates a third NPCA parameter set for AP 1804. In example 1800, the third NPCA parameter set indicates a channel "NPCAPCH 1812” for the second NPCA PCH used byAP 1804. In an example, the third NPCA parameter set further indicates a third bandwidth for the second NPCA PCH. In an embodiment, frame 1822 may further indicate a first time period (not shown in FIG. 18) during which AP 1804 uses the third NPCA parameter set instead of the second NPCA parameter set. In an embodiment, the ICF comprises a duration field that indicates the first time period. In an example, based on the traffic arriving at AP 1802 at time t3 being LL traffic, AP 1802 may relocate the NPCA PCH of AP 1804 as shown in FIG. 18 to be non-adjacent to the NPCA PCH of AP 1802. This allows AP 1802 to expand the bandwidth of its NPCA PCH if needed (e.g., to cover both NPCA PCH 1808 and NPCA PCH 1810) without interfering the NPCA operation of AP 1804. In another example, based on AP 1802 gaining access to PCH 1806 at time t4, AP 1802 may determine to increase the bandwidth of the NPCA PCH of AP 1804 (e.g., to cover both NPCA PCH 1810 and a portion of NPCA PCH 1808), during the TXOP, since AP 1802 will not require its NPCA PCH 1808 during the TXOP.

[0182] Subsequently, as owner of the TXOP, AP 1802 transmits a frame 1826 (e.g., to a STA associated with AP 1802) on the PCH. AP 1804 detects frame 1826 on the PCH, sets a NAV 1824 for the PCH based on frame 1826, and switches to NPCA PCH 1812 ata time t5. In an example, after switching to NPCA PCH 1812, AP 1804 accesses NPCA PCH 1812 to transmit a frame 1828, e.g., to a STA associated with AP 1804. In an example, AP 1804 may use the entirety of the third bandwidth of NPCA PCH 1812 to transmit frame 1828. AP 1804 returns to PCH 1806 at / before expiration of NAV 1824 at a time t6. In an embodiment, AP 1804 may be configured to return to using the second NPCA parameter set upon returning to PCH 1806. That is, frame 1822 may be configured to change the NPCA parameter set for AP 1804 only during NAV 1824 and until AP 1804 returns to PCH 1806.

[0183] As described above, the Co-NPCA procedure illustrated by example 1800 allows AP 1802 to change the NPCA parameter set for AP 1804 in the same frame (e.g., frame 1822) that initiates the TXOP for AP 1802 on the PCH. In another embodiment (not shown in FIG. 18), AP 1804 may be configured to update its NPCA parameter set as well as switch from the PCH to the NPCA PCH based on the frame (e.g., frame 1822) that initiates the TXOP for AP 1802 on the PCH.

[0184] FIG. 19 illustrates an example 1900 of another procedure according to an embodiment. The procedure illustrated in FIG. 19 may be used to enable coordinated NPCA (Co-NPCA) operation, according to which an AP may adjust the NPCA parameter set of another AP, e.g., after a multi-AP NPCA negotiation phase between the two APs. Example 1900 is provided for the purpose of illustration only and is not limiting of embodiments of the present disclosure. As shown in FIG. 19, example 1900 may include an AP 1902, an AP 1904, and a STA 1906. In an embodiment, each of AP 1902 and AP 1904 may be an MLD. In an embodiment, APs 1902 and 1904 may form a multi-AP group. AP 1902 may be coordinating AP of the multi-AP group, and AP 1904 may be a coordinated AP of the multi-AP group. In an example, AP 1902 may be an embodiment of AP 1602, and AP 1904 may be an embodiment of AP 1604. In example 1900, it is assumed that STA 1906 is associated with AP 1902.Docket No.: 25-3007PCT

[0185] Example 1900 may include AP 1902 transmitting a frame 1908 indicating a service period (SP) 1912 for STA 1906. In an embodiment, the SP may be periodic. The SP may comprise a target wake time (TWT) SP or a restricted TWT (RTWT) SP. Frame 1908 may comprise a beacon frame.

[0186] In an embodiment, before or after transmitting frame 1908, AP 1902 may transmit to AP 1904 a frame 1910 modifying a first NPCA parameter set used by AP 1904. Frame 1910 may be an embodiment of frame 1614 or frame 1706 described above. In an example, frame 1910 indicates a second NPCA parameter set to be used by AP 1904. As described above, the second NPCA parameter set may indicate a modified channel location / number and / or a modified bandwidth of the NPCA PCH of AP 1904.

[0187] In an embodiment, frame 1910 further indicates a time period 1914 during which AP 1904 is to use the second NPCA parameter set. In an embodiment, to avoid / reduce interference on the NPCA PCH during SP 1912, AP 1902 may determine the second NPCA parameter set to reduce potential interference by AP 1904 during NPCA operation (e.g., by moving the NPCA PCH of AP 1904 away from the NPCA PCH of AP 1902 and / or by reducing the bandwidth of the NPCA PCH of AP 1904) and may overlap time period 1914 with SP 1912. In an embodiment, time period 1914 may be configured to align with SP 1912. In an embodiment, where SP 1912 has a first periodicity, time period 1914 may have a second periodicity based on the first periodicity. In an embodiment, the second periodicity is equal to the first periodicity.

[0188] In another embodiment, AP 1902 may determine the second NPCA parameter set to increase the NPCA PCH bandwidth available for AP 1904. For example, AP 1904 may have requested an increased NPCA PCH bandwidth in response to increased QoS requirements. To avoid / reduce NPCA PCH interference during SP 1912, AP 1902 may determine not to overlap time period 1914 with SP 1912. In an embodiment, time period 1914 maybe configured to avoid overlap with SP 1912. In another embodiment, AP 1902 may schedule SP 1912 not to overlap with time period 1914.

[0189] FIG. 20 illustrates an example process 2000 according to an embodiment. Example process 2000 is provided for the purpose of illustration only and is not limiting embodiments. Process 2000 may be performed by a first AP, such as AP 1602, AP 1702, AP 1802, or AP 1902 described above. As shown in FIG. 20, process 2000 may comprise step 2002.

[0190] Step 2002 comprises transmitting, by the first AP to a second AP, a first frame indicating a first NPCA parameter set. In an embodiment, the first frame may further indicate a first time period during which the second AP uses (is to use or is requested / recommended to use) the first NPCA parameter set. In an embodiment, the first NPCA parameter set indicates at least one of: a first channel location of a first NPCA PCH of the second AP; and a first bandwidth of the first NPCA PCH.

[0191] In an embodiment, the first AP comprises a coordinating AP of a multi-AP group comprising both the first AP and the second AP. In an embodiment, the second AP comprises a coordinated AP of the multi-AP group.

[0192] In an embodiment, the first frame indicates a starting time of the first time period, a duration of the first time period, and / or an end time of the first time period.

[0193] In an embodiment, the first NPCA PCH corresponds to a channel within a bandwidth of a BSS of the second AP that the second AP and its associated NPCA non-AP STAs switch to in order to perform NPCA operation.Docket No.: 25-3007PCT

[0194] In an embodiment, the second AP is configured to switch from a first PCH of the second AP to the first NPCA PCH based on detecting an inter-BSS PPDU on the first PCH.

[0195] In an embodiment, the first channel location of the first NPCA PCH comprises a channel number of the first NPCA PCH.

[0196] In an embodiment, the first bandwidth of the first NPCA PCH comprises the first NPCA PCH and zero or more channels, within the bandwidth of the BSS of the second AP, adjacent to the first NPCA PCH.

[0197] In an embodiment, the first bandwidth of the first NPCA PCH is equal to a multiple of 20 MHz.

[0198] In an embodiment, process 2000 further comprises transmitting, by the first AP to the second AP, a second frame indicating a second NPCA parameter set of the first AP. In an embodiment, the second NPCA parameter set comprises: a second channel location of a second NPCA PCH of the first AP; and a second channel bandwidth of the second NPCA PCH.

[0199] In an embodiment, process 2000 further comprises receiving, by the first AP from the second AP, a third frame indicating a third NPCA parameter of the second AP. In an embodiment, the third NPCA parameter set comprises: a third channel location of the first NPCA PCH of the second AP; and a third channel bandwidth of the first NPCA PCH.

[0200] In an embodiment, the second channel location is same as or different than the third channel location.

[0201] In an embodiment, the second channel bandwidth is same as or different than the third channel bandwidth.

[0202] In an embodiment, the first channel location is same as or different than the third channel location.

[0203] In an embodiment, the first channel bandwidth is same as or different than the third channel bandwidth.

[0204] In an embodiment, transmitting the first frame in step 2002 comprises transmitting the first frame after transmitting the second frame. In an embodiment, transmitting the first frame in step 2002 comprises transmitting the first frame after receiving the third frame.

[0205] In an embodiment, process 2000 further comprises changing, by the first AP, at least one of the second channel location and the second channel bandwidth after receiving the third frame.

[0206] In an embodiment, the first frame requests, recommends, or instructs that the second AP use the first NPCA parameter set during the first time period.

[0207] In an embodiment, process 2000 further comprises receiving, by the first AP from the second AP, a fourth frame accepting or rejecting the first NPCA parameter set or the first time period.

[0208] In an embodiment, process 2000 further comprises receiving, by the first AP from the second AP, in response to the first frame, a fifth frame indicating a fourth NPCA parameter set and a second time period during which the second AP uses the fourth NPCA parameter set In an embodiment, the fourth NPCA parameter set comprises a fourth channel location, different than the first channel location, of the first NPCA PCH of the second AP. In an embodiment, the fourth NPCA parameter set comprises a fourth bandwidth, different than the first channel bandwidth, of the first NPCA PCH.

[0209] In an embodiment, the first frame indicates a periodic NPCA operation schedule for the second AP. In an embodiment, the periodic NPCA operation schedule indicates the first time period. In an embodiment, the periodic NPCA operation schedule indicates a third time period during which the second AP uses a fifth NPCA parameter set. In anDocket No.: 25-3007PCTembodiment, the fifth NPCA parameter set corresponds to a default NPCA parameter set used by the second AP. The default NPCA parameter set may correspond to a pre-configured NPCA parameter set of the second AP. In another embodiment, the fifth NPCA parameter set is negotiated by the second AP with the first AP.

[0210] In an embodiment, the first frame comprises an initial control frame (ICF). In an embodiment, the first AP obtains a TXOP on a second PCH of the first AP after transmitting the ICF. In an embodiment, the ICF comprises a duration field that indicates the first time period.

[0211] In an embodiment, process 2000 further comprises transmitting, by the first AP, a sixth frame indicating a service period (SP) for a STA associated with the first AP. In an embodiment, the SP comprises a restricted target wake time (R-TWT) SP. In an embodiment, process 2000 further comprises determining the first time period to overlap with the SP. In an embodiment, process 2000 further comprises determining the first time period to not overlap with the SP.

[0212] In an embodiment, the first AP and / or the second AP comprises an AP MLD.

[0213] In an embodiment, the first frame comprises an identifier of the first NPCA parameter set. In an embodiment, the identifier identifies the first NPCA parameter set from among a plurality of NPCA parameter sets. In an embodiment, the plurality of NPCA parameter sets are pre-negotiated between the first AP and the second AP.

[0214] FIG. 21 illustrates an example process 2100 according to an embodiment. Example process 2100 is provided for the purpose of illustration only and is not limiting embodiments. Process 2100 may be performed by a first AP, such as AP 1604, AP 1704, AP 1804, or AP 1904 described above. As shown in FIG. 21, process 2100 may comprise step 2102.

[0215] Step 2102 comprises receiving, by the first AP to a second AP, a first frame indicating a first NPCA parameter set. In an embodiment, the first frame may further indicate a first time period during which the first AP uses (is to use or is requested / recommended to use) the first NPCA parameter set. In an embodiment, the first NPCA parameter set indicates at least one of: a first channel location of a first NPCA PCH of the first AP; and / or a first bandwidth of the first NPCA PCH.

[0216] In an embodiment, the first AP comprises a coordinated AP of a multi-AP group comprising both the first AP and the second AP. In an embodiment, the second AP comprises a coordinating AP of the multi-AP group.

[0217] In an embodiment, the first frame indicates a starting time of the first time period, a duration of the first time period, and / or an end time of the first time period.

[0218] In an embodiment, the first NPCA PCH corresponds to a channel within a bandwidth of a BSS of the forst AP that the first AP and its associated NPCA non-AP STAs switch to in order to perform NPCA operation.

[0219] In an embodiment, the first AP is configured to switch from a first PCH of the first AP to the first NPCA PCH based on detecting an inter-BSS PPDU on the first PCH.

[0220] In an embodiment, the first channel location of the first NPCA PCH comprises a channel number of the first NPCA PCH.

[0221] In an embodiment, the first bandwidth of the first NPCA PCH comprises the first NPCA PCH and zero or more channels, within the bandwidth of the BSS of the first AP, adjacent to the first NPCA PCH.Docket No.: 25-3007PCT

[0222] In an embodiment, the first bandwidth of the first NPCA PCH is equal to a multiple of 20 MHz.

[0223] In an embodiment, process 2100 further comprises receiving, by the first AP from the second AP, a second frame indicating a second NPCA parameter set of the first AP. In an embodiment, the second NPCA parameter set comprises: a second channel location of a second NPCA PCH of the first AP; and / or a second channel bandwidth of the second NPCA PCH.

[0224] In an embodiment, process 2100 further comprises transmitting, by the first AP to the second AP, a third frame indicating a third NPCA parameter of the first AP. In an embodiment, the third NPCA parameter set comprises: a third channel location of the first NPCA PCH of the first AP; and / or a third channel bandwidth of the first NPCA PCH.

[0225] In an embodiment, the second channel location is same as or different than the third channel location.

[0226] In an embodiment, the second channel bandwidth is same as or different than the third channel bandwidth.

[0227] In an embodiment, the first channel location is same as or different than the third channel location.

[0228] In an embodiment, the first channel bandwidth same as or different than the third channel bandwidth.

[0229] In an embodiment, receiving the first frame in step 2102 comprises receiving the first frame after receiving the second frame. In an embodiment, receiving the first frame in step 2102 comprises receiving the first frame after transmitting the third frame.

[0230] In an embodiment, process 2100 further comprises changing, by the first AP, at least one of the third channel location and the third channel bandwidth before transmitting the third frame.

[0231] In an embodiment, the first frame requests, recommends, or instructs that the first AP use the first NPCA parameter set during the first time period.

[0232] In an embodiment, process 2100 further comprises transmitting, by the first AP to the second AP, a fourth frame accepting or rejecting the first NPCA parameter set or the first time period.

[0233] In an embodiment, process 2100 further comprises transmitting, by the first AP to the second AP, in response to the first frame, a fifth frame indicating a fourth NPCA parameter set and / or a second time period during which the first AP uses the fourth NPCA parameter set. In an embodiment, the fourth NPCA parameter set comprises a fourth channel location, different than the first channel location, of the first NPCA PCH of the first AP. In an embodiment, the fourth NPCA parameter set comprises a fourth bandwidth, different than the first channel bandwidth, of the first NPCA PCH.

[0234] In an embodiment, the first frame indicates a periodic NPCA operation schedule for the first AP. In an embodiment, the periodic NPCA operation schedule indicates the first time period. In an embodiment, the periodic NPCA operation schedule indicates a third time period during which the first AP uses a fifth NPCA parameter set. In an embodiment, the fifth NPCA parameter set corresponds to a default NPCA parameter set used by the first AP. The default NPCA parameter set may correspond to a pre-configured NPCA parameter set of the first AP. In another embodiment, the fifth NPCA parameter set is negotiated by the first AP with the second AP.

[0235] In an embodiment, the first frame comprises an initial control frame (ICF). In an embodiment, the second AP obtains a TXOP on a second PCH of the second AP after transmitting the ICF. In an embodiment, the ICF comprises a duration field that indicates the first time period.Docket No.: 25-3007PCT

[0236] In an embodiment, process 2100 further comprises receiving, by the first AP from the second AP, a sixth frame indicating a service period (SP) for a STA associated with the second AP. In an embodiment, the SP comprises a restricted target wake time (R-TWT) SP. In an embodiment, the second AP determines the first time period to overlap with the SP. In another embodiment, the second AP determines the first time period to not overlap with the SP.

[0237] In an embodiment, the first AP and / or the second AP comprises an AP MLD.

[0238] In an embodiment, the first frame comprises an identifier of the first NPCA parameter set. In an embodiment, the identifier identifies the first NPCA parameter set from among a plurality of NPCA parameter sets. In an embodiment, the plurality of NPCA parameter sets are pre-negotiated between the first AP and the second AP.

Claims

Docket No.: 25-3007PCTCLAIMSWhat is claimed is:

1. A method comprising:transmitting, by a first access point (AP) to a second AP, a first frame indicating a first non-primary channel access (NPCA) parameter set for the second AP, wherein the first NPCA parameter set indicates:a first channel location of a first NPCA primary channel (PCH) of the second AP; and a first channel bandwidth of the first NPCA PCH;receiving, by the first AP from the second AP, a second frame indicating acceptance of the first NPCA parameter set by the second AP; andafter receiving the second frame, transmitting, by the first AP to the second AP, a third frame indicating a second NPCA parameter set and a time period during which the second AP uses the second NPCA parameter set instead of the first NPCA parameter set, wherein the second NPCA parameter set indicates at least one of:a second channel location of the first NPCA PCH; anda second bandwidth of the first NPCA PCH.

2. A method comprising:transmitting, by a first access point (AP) to a second AP, a first frame indicating a first non-primary channel access (NPCA) parameter set and a first time period during which the second AP uses the first NPCA parameter set, wherein the first NPCA parameter set indicates at least one of:a first channel location of a first NPCA primary channel (PCH) of the second AP; and a first bandwidth of the first NPCA PCH.

3. The method of claim 2, wherein the first AP comprises a coordinating AP of a multi-AP group comprising the first AP and the second AP.

4. The method of claim 3, wherein the second AP comprises a coordinated AP of the multi-AP group.

5. The method of any of claims 2-4, wherein the first frame indicates a starting time of the first time period.

6. The method of any of claims 2-5, wherein the first frame indicates a duration of the first time period.

7. The method of any of claims 2-6, wherein the first frame indicates an end time of the first time period.

8. The method of any of claims 2-7, wherein the first NPCA PCH corresponds to a channel within a bandwidth of a basic service set (BSS) of the second AP that the second AP and its associated NPCA non-AP stations (STAs) switch to in order to perform NPCA operation.

9. The method of any of claims 2-7, wherein the second AP is configured to switch from a first primary channel (PCH) of the second AP to the first NPCA PCH based on detecting an inter-basic service set (inter-BSS) physical layer protocol data unit (PPDU) on the first PCH.

10. The method of any of claims 2-9, wherein the first channel location of the first NPCA PCH comprises a channel number of the first NPCA PCH.Docket No.: 25-3007PCT11. The method of any of claims 2-10, wherein the first bandwidth of the first NPCA PCH comprises the first NPCA PCH and zero or more channels, within a bandwidth of a basic service set (BSS) of the second AP, adjacent to the first NPCA PCH.

12. The method of any of claims 2-11 , wherein the first bandwidth of the first NPCA PCH is equal to a multiple of 20 MHz.

13. The method of any of claims 2-12, further comprising transmitting, by the first AP to the second AP, a second frame indicating a second NPCA parameter set of the first AP, wherein the second NPCA parameter set comprises: a second channel location of a second NPCA PCH of the first AP; anda second channel bandwidth of the second NPCA PCH.

14. The method of claim 13, further comprising receiving, by the first AP from the second AP, a third frame indicating a third NPCA parameter set of the second AP, wherein the third NPCA parameter set comprises:a third channel location of the first NPCA PCH of the second AP; anda third channel bandwidth of the first NPCA PCH.

15. The method of claim 14, wherein the second channel location is same as or different than the third channel location.

16. The method of any of claims 14-15, wherein the second channel bandwidth is same as or different than the third channel bandwidth.

17. The method of any of claims 14-16, wherein the first channel location is same as or different than the third channel location.

18. The method of any of claims 14-17, wherein the first channel bandwidth is same as or different than the third channel bandwidth.

19. The method of any of claims 13-18, wherein transmitting the first frame comprises transmitting the first frame after transmitting the second frame.

20. The method of any of claims 14-18, wherein transmitting the first frame comprises transmitting the first frame after receiving the third frame.

21. The method of any of claims 14-18, further comprising changing, by the first AP, at least one of the second channel location and the second channel bandwidth after receiving the third frame.

22. The method of any of claims 2-21 , wherein the first frame requests / recommends / instructs that the second AP use the first NPCA parameter set during the first time period.

23. The method of any of claims 2-22, further comprising receiving, by the first AP from the second AP, a fourth frame accepting or rejecting the first NPCA parameter set or the first time period.

24. The method of any of claims 2-22, further comprising receiving, by the first AP from the second AP, in response to the first frame, a fifth frame indicating a fourth NPCA parameter set and a second time period during which the second AP uses the fourth NPCA parameter set.

25. The method of claim 24, wherein the fourth NPCA parameter set comprises:Docket No.: 25-3007PCTa fourth channel location, different than the first channel location, of the first NPCA PCH of the second AP; anda fourth bandwidth, different than the first channel bandwidth, of the first NPCA PCH.

26. The method of any of claims 2-25, wherein the first frame indicates a periodic NPCA operation schedule for the second AP.

27. The method of claim 26, wherein the periodic NPCA operation schedule indicates / comprises the first time period.

28. The method of any of claims 26-27, wherein the periodic NPCA operation schedule indicates / comprises a third time period during which the second AP uses a fifth NPCA parameter set.

29. The method of claim 28, wherein the fifth NPCA parameter set corresponds to a default NPCA parameter set used by the second AP.

30. The method of claim 28, wherein the fifth NPCA parameter set is negotiated by the second AP with the first AP.

31. The method of claim 2, wherein the first frame comprises an initial control frame (ICF).

32. The method of claim 31 , wherein the first AP obtains a transmission opportunity (TXOP) on a second PCH of the first AP after transmitting the ICF.

33. The method of any of claims 31-32, wherein the ICF comprises a duration field that indicates the first time period.

34. The method of any of claims 2-33, further comprising transmitting, by the first AP, a sixth frame indicating a service period (SP) for a station (STA) associated with the first AP.

35. The method of claim 34, wherein the SP comprises a restricted target wake time (R-TWT) SP.

36. The method of any of claims 34-35, further comprising determining the first time period to overlap with the SP.

37. The method of any of claims 34-35, further comprising determining the first time period to not overlap with the SP.

38. The method of any of claims 2-37, wherein the first AP or the second AP comprises an AP multi-link device (MLD).

39. The method of claim 2, wherein the first frame comprises an identifier of the first NPCA parameter set, and wherein the identifier identifies the first NPCA parameter set from among a plurality of NPCA parameter sets.

40. The method of claim 39, wherein the plurality of NPCA parameter sets are pre-negotiated between the first AP and the second AP.

41. 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 1-40.

42. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform a method according to any of claims 1-40.

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