Non-primary channel access (NPCA) switching operation

Abstract

An access point (AP) receives from a first station (STA), via a primary channel (PCH), an association request frame comprising an indication of whether the first STA supports a non-primary channel access (NPCA) mode of operation, where, in the NPCA mode of operation, the first STA switches from the PCH to an NPCA PCH based on detecting an inter-basic service set (BSS) physical layer protocol data unit (PPDU) on the PCH. The AP transmits to the first STA an association response frame indicating that the AP supports the NPCA mode of operation, where, in the NPCA mode of operation, the AP switches from the PCH to the NPCA PCH based on detecting an inter-BSS PPDU on the PCH. The AP determines that a PPDU being received via the PCH comprises an inter-BSS PPDU and switches from the PCH to the NPCA PCH based on the indication and the determining.

Description

Docket No.: 24-3067PCTTITLE NON-PRIMARY CHANNEL ACCESS (NPCA) SWITCHING OPERATIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 739,148, filed December 27, 2024, U.S. Provisional Application No. U.S. Provisional Application No. 63 / 768,223, filed March 7, 2025, and U.S. Provisional Application No. 63 / 771 ,099, filed March 13, 2025, all of which are hereby incorporated by reference in their entireties.BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0005] FIG. 3 illustrates 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 is an example that illustrates an MU-RTS / CTS procedure.

[0011] FIG. 9 is 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 shows an example that illustrates a problem that may arise in existing NPCA operation illustrated in FIG. 12.

[0016] FIG. 14 shows an example of a procedure according to an embodiment.

[0017] FIG. 15 shows an example of another procedure according to an embodiment.

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

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

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

[0021] FIG. 19 illustrates an example process according to an embodiment.

[0022] FIG. 20 illustrates an example process according to an embodiment.Docket No.: 24-3067PCTDETAILED DESCRIPTION

[0023] In the present disclosure, various embodiments are presented as examples of how the disclosed techniques may be implemented and / or how the disclosed techniques may be practiced in environments and scenarios. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope. After reading the description, it will be apparent to one skilled in the relevant art how to implement alternative embodiments. The present embodiments may not be limited by any of the described exemplary embodiments. The embodiments of the present disclosure will be described with reference to the accompanying drawings. Limitations, features, and / or elements from the disclosed example embodiments may be combined to create further embodiments within the scope of the disclosure. Any figures which highlight the functionality and advantages are presented for example purposes only. The disclosed architecture is sufficiently flexible and configurable, such that it may be utilized in ways other than those shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments.

[0024] 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.

[0025] 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.

[0026] If A and B are sets and every element of A is an element of B, A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B = {STA1 , STA2] are: {STA1}, {STA2}, and {STA1 , STA2}. The phrase “based on” (or equally “based at least on”) isDocket No.: 24-3067PCTindicative that the phrase following the term “based on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “in response to” (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “depending on” (or equally “depending at least to”) is indicative that the phrase following the phrase “depending on" is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “employing / using” (or equally “employing / using at least”) is indicative that the phrase following the phrase “employing / using” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g., hardware with a biological element) or a combinationDocket No.: 24-3067PCTthereof, which may be behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab or the like) or a modeling / simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. It may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and / or quantum hardware. Examples of programmable hardware comprise: computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages such as assembly, C, C++, or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardware description language (VHDL) or Verilog that configure connections between internal hardware modules with lesser functionality on a programmable device. The mentioned technologies are often used in combination to achieve the result of a functional module.

[0031] FIG. 1 illustrates example wireless communication networks in which embodiments of the present disclosure may be implemented.

[0032] 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.

[0033] 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.

[0034] 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).

[0035] 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.

[0036] 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).

[0037] For example, in FIG. 1, STAs 106-4, 106-5, and 106-6 may be configured to form a first IBSS 112-1. Similarly, STAs 106-7 and 106-8 may be configured to form a second IBSS 112-2. Since an IBSS doesDocket No.: 24-3067PCTnot 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.

[0038] A STA as a predetermined functional medium may include a medium access control (MAC) layer that complies with an IEEE 802.11 standard. A physical layer interface for a radio medium may be used among the APs and the non-AP stations (STAs). The STA may also be referred to using various other terms, including mobile terminal, wireless device, wireless transmit / receive unit (WTRU), user equipment (UE), mobile station (MS), mobile subscriber unit, or user. For example, the term "user” may be used to denote a STA participating in uplink Multi-user Multiple Input, Multiple Output (MU MIMO) and / or uplink Orthogonal Frequency Division Multiple Access (OFDMA) transmission.

[0039] 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 be used by a receiving device to decode the subsequent data in the PSDU. In instances in which PPDUs are transmitted over a bonded channel (channel formed through channel bonding), the preamble fields may be duplicated and transmitted in each of the multiple component channels. The PHY preamble may include both a legacy portion (or “legacy preamble”) and a non-legacy portion (or “non-legacy preamble”). The legacy preamble may be used for packet detection, automatic gain control and channel estimation, among other uses. The legacy preamble also may generally be used to maintain compatibility with legacy devices. The format of, coding of, and information provided in the non-legacy portion of the preamble is based on the particular IEEE 802.11 protocol to be used to transmit the payload.

[0040] A frequency band may include one or more sub-bands or frequency channels For example, PPDUs conforming to the IEEE 802.11n, 802.11ac, 802.11ax and / or 802.11be standard amendments may be transmitted over the 2.4 GHz, 5 GHz, and / or 6 GHz bands, each of which may be divided into multiple 20 MHz channels. The PPDUs may be transmitted over a physical channel having a minimum bandwidth of 20 MHz. Larger channels may be 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.

[0041] 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.Docket No.: 24-3067PCT

[0042] 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.

[0043] Memory 230 / 280 may include a read-only memory (ROM), a random-access memory (RAM), a flash memory, a memory card, a storage medium, and / or other storage unit. Memory 230 / 280 may comprise one or more non-transitory computer readable mediums. Memory 230 / 280 may store computer program instructions or code that may be executed by processor 220 / 270 to carry out one or more of the operations / embodiments discussed in the present application. Memory 230 / 280 may be implemented (or positioned) within processor 220 / 270 or external to processor 220 / 270. Memory 230 / 280 may be operatively connected to processor 220 / 270 via various means known in the art.

[0044] 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 by the IEEE 802.11 standard. As such, STA 210 and / or AP 260 may each implement multiple PHY layers. The multiple PHY layers may be implemented using one or more of transceivers 240 / 290.

[0045] 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.

[0046] As shown in FIG. 3, a MAC frame includes a MAC header, a variable length frame body, and a frame check sequence (FCS).

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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. BitsDocket No.: 24-3067PCTwithin 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] The power management subfield is used to indicate the power management mode of a STA.

[0055] 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 transmitted by 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.

[0056] The protected frame subfield is set to 1 if the frame body field contains information that has been processed by a cryptographic encapsulation algorithm.

[0057] The +HTC subfield indicates that the MAC frame contains an HT control field.

[0058] 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.

[0059] 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 ofthe address field (1-4) within the MAC header,Docket No.: 24-3067PCTindependent 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.

[0060] 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

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] FIG. 4 illustrates an example trigger frame 400. Trigger frame 400 may correspond to a basic trigger frame as defined in the existing IEEE 802.11 ax 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.

[0066] 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.

[0067] 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.

[0068] 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, theDocket No.: 24-3067PCTDuration 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).

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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 SIPS (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.

[0073] 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.

[0074] 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.Docket No.: 24-3067PCT

[0075] 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.

[0076] 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 P802.11 be / D3.1 , March 2023”).

[0077] 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.

[0078] 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 may include 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.

[0079] 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 toDocket No.: 24-3067PCTRTS 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-S1G STA, the NAV indicates idle when the NAV count is 0 or when the NAV count is non-zero 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] FIG. 8 is an example 800 that illustrates a multi-user Request-to-Send (MU-RTS) / Clear-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).

[0084] 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.

[0085] 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.Docket No.: 24-3067PCT

[0086] 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.

[0087] 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 STAto 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.

[0088] 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.

[0089] 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.

[0090] In example 800, on receiving MU-RTS trigger frame 808, STAs 804 and 806 respond by transmitting respectively CTS frames 810 and 812 to AP 802. In an example, STAs 804 and 806 begin the transmissionDocket No.: 24-3067PCTof CTS frames 810 and 812, respectively, at the SIFS 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.

[0091] 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 SIFS period.

[0092] 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.

[0093] 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.

[0094] On receiving CTS frame 810 and / or CTS frame 812, AP 802 may wait one SIFS 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.

[0095] It is envisioned in future IEEE 802.11 standards that a STA (AP STA or non-AP STA) may access a non-primary channel to communicate with another STA. Such operation may be referred to as non-primary channel access (NPCA) operation. Specifically, in addition to a default primary channel (which is used by all STAs in the BSS and via which the AP transmits management frames), the STA may have a channel considered as an NPCA primary channel. The NPCA primary channel may be a secondary channel of the BSS. The STA may transmit or receive on a channel that includes an NPCA primary channel but that does not necessarily include the primary channel (e.g., when the primary channel is unavailable). The STA may maintain a NAV for an NPCA primary channel independent of the NAV associated with the primary channel.Docket No.: 24-3067PCT

[0096] A STA (AP STA or non-AP STA) that supports NPCA operation may be called an NPCA STA. An AP (AP STA) that supports NPCA operation may be called an NPCA AP. A non-AP STA that supports NPCA operation may be called a non-AP NPCA STA.

[0097] FIG. 9 shows an example that illustrates NPCA operation. 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 .

[0098] 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 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).

[0099] 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 a frame carried in the inter-BSS PPDU, a transmission opportunity (TXOP) duration field of the inter-BSS PPDU, or a 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.: 24-3067PCT

[0100] 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”).

[0101] 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.

[0102] A NPCA STA may indicate its support of NPCA operation. In an implementation, to indicate support of NPCA operation, the NPCA STA may set an NPCA Supported field of a UHR MAC Capabilities Information field of a UHR Capabilities element to 1 . The UHR Capabilities element may be provided in an Association Request frame, a Reassociation Request frame, or a Probe Request frame by a non-AP NPCA STA The UHR Capabilities element may be provided in an Association Response frame, a Reassociation Response frame, a Probe Response frame, or a Beacon frame by an NPCA AP.

[0103] An NPCA AP may enable or disable NPCA operation in a BSS. In an implementation, the NPCAAP may enable NPCA operation for the BSS by setting an NPCA Operation Information Present field to 1. The NPCA AP may set the NPCA Operation Information Present field to 0 to indicate that NPCA operation is disabled. The NPCA Operation Information Present field may be a field of a UHR Operation Parameters field of a UHR Operation element. The UHR Operation element may be provided in an Association Response frame, a Reassociation Response frame, a Probe Response frame, or a Beacon frame by the NPCA AP. In an implementation, an NPCA AP that has an operating bandwidth less than 80 MHz (or less than 160 MHz) may not enable NPCA operation.

[0104] An NPCA STA that has enabled NPCA operation may announce NPCA Operation Information in frames that the NPCA STA transmits. In an implementation, the NPCA STA may include an NPCA Operation Information field in the UHR Operation element. The NPCA Operation Information field may include an NPCA Primary Channel field, an NPCA Minimum Duration Threshold field, an NPCA Switching Delay field, and anDocket No.: 24-3067PCTNPCA Switch Back Delay field. The NPCA Primary Channel field indicates a channel number of a channel within the BSS bandwidth that corresponds to the NPCA PCH (the channel to which the NPCA AP and its associated NPCA non-AP STAs switch to perform NPCA operation). The NPCA Minimum Duration Threshold field indicates a minimum duration of inter-BSS activity (inter-BSS PPDU or inter-BSS TXOP) that is required to have been indicated on the primary channel of the BSS as a necessary condition to permit an NPCA STA to switch to the NPCA primary channel to perform NPCA operation. The NPCA Switching Delay field indicates the time needed by the NPCA STA to switch from the BSS primary channel to the NPCA primary channel, e.g., in units of 4 usee. The NPCA Switch Back Delay field indicates the time needed by the NPCA STA to switch from the NPCA primary channel to the BSS primary channel, e.g., in units of 4 usee.

[0105] In an implementation, a non-AP NPCA STA shall not switch to the NPCA primary channel for NPCA operation if the value of the most recently received NPCA Operation Information Present field from its associated AP is equal to 0. An NPCA AP shall not switch to the NPCA primary channel for NPCA operation if the value of its most recently transmitted NPCA Operation Information Present field is equal to 0.

[0106] In an implementation, an NPCA STA may switch to the NPCA primary channel for NPCA operation if the value of the most recently received or transmitted NPCA Operation Information Present subfield corresponding to the BSS of which the NPCA STA is a member if equal to 1 and any of conditions a), b), or c) is met:a) 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 (or one or more) of the following conditions are true:a. the PPDU is classified by the STA as an inter-BSS PPDU following the procedure of Intra-BSS and inter-BSS PPDU classification.b. the duration of the PPDU (e.g., determined using one or more parameters (e.g., TXOP_DURATION) of the RXVECTOR associated with the 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.c. the 20 / 40 / 80 / 160 MHz channel occupied by the PPDU is identified by the STA, based on the Bandwidth field in the PHY preamble of the PPDU and the channel allocations in the corresponding band, and the channel occupied by the PPDU does not overlap with the NPCA primary channel.b) the STA received a PPDU containing a Control frame and / or a PPDU containing an initial response frame of a Control frame exchange on the BSS primary channel and all of the following conditions apply: a. the received PPDU(s) are classified by the STA as inter-BSS PPDU(s) following the procedure of Intra-BSS and inter-BSS PPDU classification.b. the TXOP duration, determined from the Duration field of the received frame(s), 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.Docket No.: 24-3067PCTc. the 20 / 40 / 80 / 160 MHz channel occupied by the received PPDU(s) is identified by the STA based on the channel allocations in the corresponding band and the PPDU bandwidth that is signaled in the received PPDU(s) or obtained from the RXVECTOR parameter CH_BANDWIDTH_IN_NON_HT of the received PPDU(s) and the channel occupied by the received PPDU(s) does not overlap with the NPCA primary channel.I. if the Control frame is an RTS frame in a non-HT (duplicate) PPDU, then it includes a bandwidth signaling TA and the signaled PPDU bandwidth is 20 MHz, 40 MHz, 80 MHz, or 160 MHz.c) The primary channel is known to be busy.

[0107] When an NPCA STA switches to the NPCA primary channel for NPCA operation, the following rules may apply:a) If the STA switches from the BSS primary channel to the NPCA primary channel based on an inter- BSS HE / EHT / UHR PPDU reception on the BSS primary channel, the STA shall initiate the switch at the NPCA HE switch time and it 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.b) If the STA switches from the BSS primary channel to the NPCA primary channel based on an inter- BSS Control frame exchange reception on the primary channel, the STA shall initiate 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.c) The STA shall use the same EDCA parameter set, MU EDCA parameter set, and EPCS EDCA parameter set values for operation on the NPCA primary channel as the STA uses on the BSS primary channel.d) Once the STA becomes ready to transmit on the NPCA primary channel, the STA may initiate a TXOP on the NPCA primary channel by following the rules defined in 10.23.2.2 (EDCA backoff procedure) and 10.23.2.4 (Obtaining an EDCA TXOP) of the IEEE 802.11 standard with the following exceptions: a. Each time that the STA switches to the NPCA primary channel, the STA shall initialize CW_NPCA[AC] to a value to be determined and randomly choose a new initial value between 0 and CW_NPCA[AC] for the backoff counter (BO_NPCA[AC]).b. QSRC_NPCA[AC] shall be set to 0.c. If the STA is a non-AP STA and the associated AP has disabled the use of untriggered UL transmissions on the NPCA primary channel for that STA, then the STA shall not initiate a TXOP on the NPCA primary channel.i.MU EDCA parameters mechanism and or some other mechanism may be used to disable untriggered UL transmissions on the NPCA primary channel.Docket No.: 24-3067PCTii.The baseline EDCA procedure may be followed on the BSS primary channel. The values of CW_NPCA[AC] and BO_NPCA[AC] may be discarded by the NPCA STA when it switches back to the BSS primary channel. e) The STA shall not initiate a transmission on the NPCA primary channel to another STA until the NPCA switching delay time of the other STA has elapsed since the NPCA HE switch time (if switching due to condition a) above) or NPCA NHT switch time (if switching due to condition b) above).f) The STA shall begin all frame exchanges on the NPCA primary channel with an NPCA initial Control frame using non-HT PPDU or non-HT duplicate PPDU format using a rate of 6 Mb / s, 12 Mb / s, or 24 Mb / s. g) An NPCA AP that transmits a Trigger frame on the NPCA primary channel shall indicate RU index values that use the NPCA primary channel as the reference primary channel. The Trigger frame shall include an explicit indication that it is being transmitted on the NPCA primary channel.h) The 20 MHz channels occupied by PPDUs transmitted by the STA shall meet all of the following conditions:a. include at least the NPCA primary channel.b. all be within the BSS bandwidth.c. not include any of the channels occupied by the inter-BSS traffic that caused the STA to switch from the BSS primary channel to the NPCA primary channel.d. not include channels that are indicated as punctured in the Disabled Subchannel Bitmap field in the EHT Operation element.e. a frame that solicits a response other than TB PPDUs may puncture 20 MHz subchannels not indicated as punctured in the Disabled Subchannel Bitmap field of the EHT Operation element.

[0108] FIG. 11 shows an example 1100 that illustrates an NPCA operation. 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).

[0109] Example 1100 may begin with the AP 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.

[0110] Subsequently, while the AP and STA operate on the PCH, transmission of a frame 1104 from an OBSS may begin on the PCH. The AP and the STA may detect frame 1104 on the PCH. In an implementation, the AP and STA may be configured to set a NAV associated with the PCH based on receiving frame 1104 on the PCH. Frame 1104 may indicate a transmission (of one or more frames including frame 1104) on the PCH. A duration of the transmission on the PCH may be provided by a duration field of frame 1104, aDocket No.: 24-3067PCTtransmission opportunity (TXOP) duration field of an inter-BSS PPDU comprising frame 1104, or a length field of the inter-BSS PPDU. The AP and STA may set their NAVs for the PCH based on the duration of the OBSS transmission on the PCH (hereinafter, OBSS NAV duration or OBSS TXOP duration).

[0111] In accordance with NPCA operation, on receiving an inter-BSS PPDU and obtaining the OBSS NAV duration, the AP and the STA may be configured to switch to the NPCA PCH for the OBSS NAV duration. The AP and STA may be configured to finish transmitting 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

[0112] 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 a frame (not shown in FIG. 11) on the NPCA PCH.

[0113] 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.

[0114] 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.

[0115] AP 1202 may respond to frame 1206 by transmitting a frame 1208 to STA 1204. Frame 1208 may indicate support of NPCA operation byAP 1202. Frame 1208 may comprise an Association Response frame, a Reassociation Response frame, a Probe Response frame, or a beacon frame, for example. In anDocket No.: 24-3067PCTimplementation, 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 byAP 1202.

[0116] 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 the enabling / 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.

[0117] 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, or a 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.

[0118] FIG. 13 shows an example 1300 that illustrates a problem that may arise in existing NPCA operation illustrated in FIG. 12. As shown in FIG. 13, example 1300 also includes AP 1202 and STA 1204 described in FIG. 12 above. Example 1300 may include STA 1204 transmitting to AP 1202 frame 1206 indicating support of NPCA operation by STA 1204; AP 1202 transmitting to STA 1204 frame 1208 indicating support of NPCA operation byAP 1202; and AP 1202 transmitting frame 1210 indicating enabling / activating of NPCA operation in the BSS.

[0119] In practice, AP 1202 and STA 1204 may experience different channel conditions on the PCH. For example, as shown in FIG. 13, STA 1204 may detect an inter-BSS PPDU 1302 on the PCH, which AP 1202 may not detect. Based on the enabling / activating of NPCA operation in the BSS, STA 1204 may switch from the PCH to the NPCA PCH on detecting inter-BSS PPDU 1302. In contrast, AP 1202 remains on the PCH.Docket No.: 24-3067PCTWithout AP 1202 switching to the NPCA PCH, STA 1204 may not communicate on the NPCA PCH after switching. Instead, STA 1204 may observe unnecessary transmissions on the NPCA PCH that do not concern STA 1204

[0120] To reduce such unnecessary switching to the NPCA PCH by STA 1204, STA 1204 may be configured to determine additional conditions for switching from the PCH to the NPCA PCH and / or to switch from the PCH to the NPCA PCH when additional conditions are true. For example, STA 1204 may be configured to switch to the NPCA PCH when STA 1204 has low latency traffic (e.g., traffic associated with a particular traffic identifier (TID)) and / or high priority traffic (e.g., AC_VI or AC_VO).

[0121] However, when STA uses additional conditions for switching to the NPCA PCH, AP 1202 may not be aware of whether STA 1204 is configured to switch from the PCH to the NPCA PCH at a given time. Without this information, AP 1202 may not know whether AP 1202 may communicate with STA 1204 after switching to the NPCA PCH. Existing NPCA operation does not support STA 1204 informing AP 1202 of whether STA 1204 is configured to switch from the PCH to the NPCA PCH at a given time. For example, as illustrated above, existing NPCA operation allows STA 1204 to inform AP 1202 of only whether STA 1204 supports NPCA operation.

[0122] Embodiments of the present disclosure, as further described below, address the above-described problem of existing technologies. In an aspect, a first STA transmits to an AP a first frame comprising a first indication regarding enabling / activating by the first STA of a first NPCA mode operation. In an embodiment, in the first NPCA mode of operation, the first STA switches from the PCH to the NPCA PCH based on detecting / receiving a first inter-BSS PDDU on the PCH. In an embodiment, the first indication indicates whether the first STA enables / activates the first NPCA mode of operation. In another embodiment, the first indication comprises a request by the first STA to enable / disable the first NPCA mode of operation. In an embodiment, the first STA determines whether to switch or switches from the PCH to the NPCA PCH based on the first indication. As such, the AP can be aware of when the first STA is configured to switch from the PCH to the NPCA PCH. In an embodiment, the AP determines whether to switch or switches from the PCH to the NPCA PCH based on the first indication. As such, the AP may switch to the NPCA PCH based on knowing that the first STA is configured to switch from the PCH to the NPCA PCH. In an example, the AP may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH when all STAs that are associated with the AP and that support NPCA operation do not enable ( / activate) NPCA operation (or the first NPCA mode of operation). In another example, the AP may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH, for transmission / communication on the NPCA PCH, when all STAs that are associated with the AP and that support NPCA operation do not enable ( / activate) NPCA operation (or the first NPCA mode of operation). In another example, the AP may ( / shall / does / decides to) not initiate a transmission on the NPCA PCH (e.g. to an NPCA non-AP STA) when all STAs that are associated with the AP and that support NPCA operation do not enable ( / activate) NPCA operation (or the first NPCA mode of operation). In thisDocket No.: 24-3067PCTexample, the AP may or may not switch to the NPCA PCH. For example, the AP may switch to the NPCA PCH for channel monitoring purposes without transmitting on the NPCA PCH. In another example, the AP may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH (or may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH, for the purpose of transmission on the NPCA PCH) when: 1) all STAs that are associated with the AP and that support NPCA operation do not enable ( / activate) NPCA operation (or the first NPCA mode of operation) and / or 2) there is at least one STA, associated with the AP, that is either a pre-UHR (or legacy) STA or a UHR STA that does not support NPCA operation (a UHR STA is a STA that complies with the IEEE 802.11bn standard amendment; a pre-UHR (or legacy) STA is a STA that complies with an IEEE 802.11 standard amendment earlier than the IEEE 802.11 bn standard (e.g., a High Throughput (HT) STA that complies with the IEEE 802.11n standard amendment, a Very High Throughput (VHT) STA that complies with the IEEE 802.11 ac standard amendment, a High Efficiency (HE) STA that complies with the IEEE 802.11ax standard amendment, or an Extremely High Throughput (EHT) STA that complies with the IEEE 802.11be standard amendment). In another example, the AP may ( / shall / does / decides to) not initiate a transmission on the NPCA PCH (e.g. to an NPCA non-AP STA) when: 1) all STAs that are associated with the AP and that support NPCA operation do not enable ( / activate) NPCA operation (or the first NPCA mode of operation) and / or 2) there is at least one STA, associated with the AP, thatiseither a pre-UHR (or legacy) STAor a UHR STA that does not support NPCA operation. In an example, the AP may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH (or may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH, for the purpose of transmission on the NPCA PCH) when there is no STA associated with the AP that enables NPCA operation (or the first NPCA mode of operation). In another example, the AP may ( / shall / does / decides to) not initiate a transmission on the NPCA PCH (e.g. to an NPCA non-AP STA) when there is no STA associated with the AP that enables NPCA operation (or the first NPCA mode of operation).

[0123] In another aspect, a first STA transmits to an AP a first frame comprising a first indication of whether the first STA supports a first NPCA mode operation. In an embodiment, in the first NPCA mode of operation, the first STA switches from the PCH to the NPCA PCH based on detecting / receiving a first inter-BSS PDDU on the PCH. In an embodiment, the first STA determines whether to switch or switches from the PCH to the NPCA PCH based on the first indication. In an embodiment, the AP determines whether to switch or switches from the PCH to the NPCA PCH based on the first indication. As such, the AP may switch to the NPCA PCH based on knowing that the first STA supports the first NPCA mode of operation. In an embodiment, the AP switches from the PCH to the NPCA PCH based on at least one STA associated therewith supporting the first NPCA mode of operation and does not switch from the PCH to the NPCA PCH based on all STAs associated therewith not supporting the first NPCA mode of operation. In an example, the AP may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH (or may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH, for the purpose of transmission on the NPCA PCH) when all STAs that areDocket No.: 24-3067PCTassociated with the AP do not support NPCA operation (or the first NPCA mode of operation). In an example, the AP may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH (or may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH, for the purpose of transmission on the NPCA PCH) when there is no STA associated with the AP that supports NPCA operation (or the first NPCA mode of operation). In another example, the AP may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH (or may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH, for the purpose of transmission on the NPCA PCH) when: 1) there is no UHR STA, associated with the AP, that supports NPCA operation (or the first NPCA mode of operation) and / or 2) there is at least one pre-UHR (or legacy) STA associated with the AP.

[0124] FIG. 14 shows an example 1400 of a procedure according to an embodiment. Example 1400 is provided for the purpose of illustration only and is not limiting of embodiments. As shown in FIG. 14, example 1400 includes an AP 1402 and STAs 1404 and 1406. STAs 1404 and 1406 may be associated with AP 1402 and may therefore belong to the same BSS as AP 1402. Each of AP 1402, STA 1404, and STA 1406 may comprise an MLD.

[0125] Example 1400 may begin with STA 1404 transmitting a frame 1408 to AP 1402. Frame 1408 comprises a first indication of whether STA 1404 supports a first NPCA mode of operation. In an embodiment, STA 1404 supporting the first NPCA mode of operation comprises STA 1404 being capable of operating according to the first NPCA mode of operation. In an embodiment, STA 1404 supporting the first NPCA mode of operation comprises (implicitly indicates) STA 1404 enabling / activating the first NPCA mode of operation. In an embodiment, according to the first NPCA mode of operation, STA 1404 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, frame 1408 comprises an association request frame, a reassociation request frame, a probe request frame, a control frame, a management frame, or an action frame. In an embodiment, frame 1408 comprises a first field set to a first value (e.g., 1) or to a second value (e.g. 0) to indicate whether STA 1404 supports the first NPCA mode of operation. In an example, the first field set to the first value may indicate that STA 1404 supports the first NPCA mode of operation. In an example, the first field set to the second value may indicate that STA 1404 does not support the first NPCA mode of operation. In example 1400, the first field for STA 1404 is set to the first value. In an embodiment, frame 1408 comprises a UHR Capabilities element, which comprises the first field. In an embodiment, the UHR Capabilities element comprises a UHR MAC Capabilities Information field, which comprises the first field In an embodiment, the first field comprises an “NPCA Supported” field.

[0126] In response to frame 1408, AP 1402 may transmit a frame 1410 to STA 1404. Frame 1410 comprises a second indication of whether AP 1402 supports a second NPCA mode of operation. In an embodiment, AP 1402 supporting the second NPCA mode of operation comprises AP 1402 being capable of operating according to the second NPCA mode of operation. In an embodiment, AP 1402 supporting the second NPCA mode of operation comprises (implicitly indicates) AP 1402 enabling / activating the second NPCA mode ofDocket No.: 24-3067PCToperation. In an embodiment, according to the second NPCA mode of operation, AP 1402 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, frame 1410 may comprise an association response frame, a reassociation response frame, a probe response frame, a beacon frame, a control frame, a management frame, or an action frame. In an embodiment, frame 1410 may comprise a second field set to a first value (e.g., 1) or to a second value (e.g. 0) to indicate whether AP 1402 may support the second NPCA mode of operation. In an example, the second field set to the first value may indicate that AP 1402 supports the second NPCA mode of operation. In an example, the second field set to the second value may indicate that AP 1402 does not support the second NPCA mode of operation. In example 1400, the second field for AP 1402 is set to the first value. In an embodiment, frame 1410 may comprise a UHR Capabilities element, which comprises the second field. In an embodiment, the UHR Capabilities element may comprise a UHR MAC Capabilities Information field, which may comprise the second field. In an embodiment, the second field may comprise an "NPCA Supported” field. In an embodiment, the second NPCA mode of operation is the same as the first NPCA mode of operation; that is, AP 1402 and STA 1404 support the same NPCA mode of operation. In another embodiment, the second NPCA mode of operation is different than the first NPCA mode of operation; that is, AP 1402 and STA 1404 support different NPCA modes of operations, e.g., AP 1402 and STA 1404 may switch from the PCH to the NPCA PCH based on different conditions (e.g., in addition to detecting / receiving an inter-BSS PPDU on the PCH).

[0127] Subsequently, STA 1406 transmits a frame 1412 to AP 1402. Frame 1412 comprises a third indication of whether STA 1406 supports the first NPCA mode of operation. In an embodiment, STA 1406 supporting the first NPCA mode of operation comprises STA 1406 being capable of operating according to the first NPCA mode of operation. In an embodiment, STA 1406 supporting the first NPCA mode of operation comprises (implicitly indicates) STA 1406 enabling / activating the first NPCA mode of operation. In an embodiment, according to the first NPCA mode of operation, STA 1406 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, frame 1412 comprises an association request frame, a reassociation request frame, a probe request frame, a control frame, a management frame, or an action frame. In an embodiment, frame 1412 comprises a first field set to a first value (e.g., 1) or to a second value (e.g. 0) to indicate whether STA 1406 supports the first NPCA mode of operation. In an example, the first field set to the first value may indicate that STA 1406 supports the first NPCA mode of operation. In an example, the first field set to the second value may indicate that STA 1406 does not support the first NPCA mode of operation. In example 1400, the first field for STA 1406 is set to the second value. In an embodiment, frame 1412 comprises a UHR Capabilities element, which comprises the first field. In an embodiment, the UHR Capabilities element comprises a UHR MAC Capabilities Information field, which comprises the first field. In an embodiment, the first field comprises an “NPCA Supported” field.

[0128] In response to frame 1412, AP 1402 may transmit a frame 1414 to STA 1406. Frame 1414 comprises the second indication of whether AP 1402 supports the second NPCA mode of operation. In an embodiment,Docket No.: 24-3067PCTthe second NPCA mode of operation is the same as the first NPCA mode of operation; that is, AP 1402 and STA 1406 support the same NPCA mode of operation. In another embodiment, the second NPCA mode of operation is different than the first NPCA mode of operation; that is, AP 1402 and STA 1406 support different NPCA modes of operations, e.g., AP 1402 and STA 1406 may switch from the PCH to the NPCA PCH based on different conditions (e.g., in addition to detecting / receiving an inter-BSS PPDU on the PCH).

[0129] In an embodiment, AP 1402, STA 1404, and / or STA 1406 may be configured to determine whether to switch (or to switch) from the PCH to the NPCA PCH based on the first indication, the second indication, and / or the third indication.

[0130] In an embodiment, AP 1402 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the second indication indicating that AP 1402 supports the second NPCA mode of operation. In another embodiment, AP 1402 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the second indication indicating that AP 1402 does not support the second NPCA mode of operation. The second indication may correspond to a last transmitted second indication by AP 1402. For example, in example 1400, the second indication may be the second indication comprised in frame 1410 and / or frame 1414.

[0131] In an embodiment, AP 1402 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on: the first indication indicating that STA 1404 supports the first NPCA mode of operation or the third indication indicating that STA 1406 supports the first NPCA mode of operation. That is, AP 1402 may switch from the PCH to the NPCA PCH if at least one STA associated therewith supports the first NPCA mode of operation. Conversely, AP 1402 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on: the first indication indicating that STA 1404 does not support the first NPCA mode of operation and the third indication indicating that STA 1404 does not support the first NPCA mode of operation. That is, AP 1402 may not switch from the PCH to the NPCA PCH if all STAs associated therewith do not support the first NPCA mode of operation. In another embodiment, AP 1402 may not switch from the PCH to the NPCA PCH when: 1) all UHR STAs associated with AP 1402 do not support NPCA operation (or the first NPCA mode of operation) and / or 2) there is at least one pre-UHR (or legacy) STA associated with AP 1402. In another embodiment, AP 1402 may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH, for the purpose of transmission / communication on the NPCA PCH, when: 1) all UHR STAs associated with AP 1402 do not support NPCA operation (or the first NPCA mode of operation) and / or 2) there is at least one pre-UHR (or legacy) STA associated with AP 1402. In another embodiment, AP 1402 may ( / shall / does / decides to) not initiate a transmission on the NPCA PCH (e.g., to an NPCA non-AP STA) when: 1) all UHR STAs associated with AP 1402 do not support NPCA operation (or the first NPCA mode of operation) and / or 2) there is at least one pre-UHR (or legacy) STA associated with AP 1402. For example, AP 1402 may ( / shallDocket No.: 24-3067PCT / does / decides to) switch from the PCH to the NPCH (e.g., for channel monitoring purposes) but may ( / shall / does / decides to) not initiate a transmission on the NPCA PCH when the above conditions are satisfied.

[0132] In an embodiment, AP 1402 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the second indication indicating that AP 1402 supports the second NPCA mode of operation and: the first indication indicating that STA 1404 supports the first NPCA mode of operation or the third indication indicating that STA 1406 supports the first NPCA mode of operation. The second indication may correspond to a last transmitted second indication by AP 1402. For example, in example 1400, the second indication may be the second indication comprised in frame 1410 and / or frame 1414.

[0133] In an embodiment, AP 1402 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on: the first indication indicating that STA 1404 supports the first NPCA mode of operation and the third indication indicating that STA 1406 supports the first NPCA mode of operation. That is, AP 1402 may switch from the PCH to the NPCA PCH if all STAs associated therewith support the first NPCA mode of operation. Conversely, AP 1402 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on: the first indication indicating that STA 1404 does not support the first NPCA mode of operation or the third indication indicating that STA 1406 does not support the first NPCA mode of operation. That is, AP 1402 may not switch from the PCH to the NPCA PCH if at least one of the STAs associated therewith does not support the first NPCA mode of operation.

[0134] In an embodiment, AP 1402 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the second indication indicating that AP 1402 supports the second NPCA mode of operation and: the first indication indicating that STA 1404 supports the first NPCA mode of operation and the third indication indicating that STA 1406 supports the first NPCA mode of operation. The second indication may correspond to a last transmitted second indication by AP 1402. For example, in example 1400, the second indication may be the second indication comprised in frame 1410 and / or frame 1414.

[0135] In an embodiment, STA 1404 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the first indication indicating that STA 1404 supports the first NPCA mode of operation. In another embodiment, STA 1404 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the first indication indicating that STA 1404 does not support the first NPCA mode of operation.

[0136] In an embodiment, STA 1404 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the first indication indicating that STA 1404 supports the first NPCA mode of operation and the second indication indicating that AP 1402Docket No.: 24-3067PCTsupports the second NPCA mode of operation. In another embodiment, STA 1404 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the first indication indicating that STA 1404 does not support the first NPCA mode of operation or the second indication indicating that AP 1402 does not support the second NPCA mode of operation. The second indication may correspond to a last transmitted second indication by AP 1402. For example, in example 1400, the second indication may be the second indication comprised in frame 1410 and / or frame 1414.

[0137] In an embodiment, STA 1404 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the first indication indicating that STA 1404 supports the first NPCA mode of operation and the third indication indicating that STA 1406 supports the first NPCA mode of operation. For example, due to a peer-to-peer (FTP) link with STA 1406, STA 1404 may switch from the PCH to the NPCA PCH only when STA 1406 supports the first NPCA mode of operation.

[0138] In an embodiment, STA 1406 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the third indication indicating that STA 1406 supports the first NPCA mode of operation. In another embodiment, STA 1406 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the third indication indicating that STA 1406 does not support the first NPCA mode of operation.

[0139] In an embodiment, STA 1406 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the third indication indicating that STA 1406 supports the first NPCA mode of operation and the second indication indicating that AP 1402 supports the second NPCA mode of operation. In another embodiment, STA 1406 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the third indication indicating that STA 1406 does not support the first NPCA mode of operation or the second indication indicating that AP 1402 does not support the second NPCA mode of operation. The second indication may correspond to a last transmitted second indication by AP 1402. For example, in example 1400, the second indication may be the second indication comprised in frame 1410 and / or frame 1414.

[0140] In an embodiment, STA 1406 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the third indication indicating that STA 1406 supports the first NPCA mode of operation and the first indication indicating that STA 1404 supports the first NPCA mode of operation. For example, due to a FTP link with STA 1404, STA 1406 may switch from the PCH to the NPCA PCH only when STA 1404 supports the first NPCA mode of operation.Docket No.: 24-3067PCT

[0141] In example 1400, AP 1402 may be configured to switch from the PCH to the NCPA PCH based on AP 1402 supporting the second NPCA mode of operation and at least one STA associated with AP 1402 supporting the first NPCA mode of operation. STA 1404 (or STA 1406) may be configured to switch from the PCH to the NPCA PCH based on STA 1404 (or STA 1406) supporting the first NPCA mode of operation. In example 1400, frame 1408 indicates that STA 1404 supports the first NPCA mode of operation; frames 1410 and 1414 indicate that AP 1402 supports the second NPCA mode of operation; and frame 1412 indicates that STA 1406 does not support the first NPCA mode of operation. As such, as shown in FIG. 14, AP 1402 and STA 1404 switch from the PCH to the NPCA PCH on detecting / receiving inter-BSS PPDU 1416 on the PCH. In contrast, STA 1406 does not switch from the PCH to the NPCA PCH on detecting / receiving inter-BSS PPDU 1416 and remains on the PCH.

[0142] In an embodiment, STA 1404 may indicate support of the first NPCA mode of operation in frame 1408 to indicate to AP 1402 that STA 1404 enables / activates the first NPCA mode of operation. STA 1404 may determine whether to enable / activate the first NPCA mode of operation based on various conditions (e.g., presence of low latency and / or high-priority traffic that may benefit from enabling / activating the first NPCA mode of operation, desire to save power by reducing channel switching operations, presence of a PTP link with another STA that does / does not support NPCA, etc.). Similarly, in an embodiment, despite supporting the first NPCA mode of operation, STA 1404 may indicate non-support of the first NPCA mode of operation in frame 1412 to indicate to AP 1402 that STA 1406 disables / deactivates the first NPCA mode of operation. STA 1406 may determine whether to enable / activate the first NPCA mode of operation based on various conditions (e.g., presence of low latency and / or high-priority traffic that may benefit from enabling / activating the first NPCA mode of operation, desire to save power by reducing channel switching operations, presence of a PTP link with another STA that does / does not support NPCA, etc.). In an embodiment, AP 1402 may indicate support of the second NPCA mode of operation in frame 1410 or frame 1414 to indicate enabling / activating NPCA operation in the BSS.

[0143] After switching to the NPCA PCH, AP 1402 may gain control of the NPCA PCH and transmit an initial control frame (ICF) 1418 to STA 1404. STA 1404 may respond to ICF 1418 by transmitting an initial control response (ICR) 1420 to AP 1402. Subsequently, AP 1402 may transmit a data frame 1422 to STA 1404, and STA 1404 may respond with a BA frame 1424 to AP 1402. AP 1402 and STA 1404 may return to the PCH at / before an end of a NAV duration determined from inter-BSS PPDU 1416.

[0144] FIG. 15 shows an example 1500 of a procedure according to an embodiment. Example 1500 is provided for the purpose of illustration only and is not limiting of embodiments. As shown in FIG. 15, example 1500 also includes AP 1402 and STAs 1404 and 1406 described in FIG. 14 above. STAs 1404 and 1406 may be associated with AP 1402 and may therefore belong to the same BSS as AP 1402. As would be understood by a person of skill in the art based on the teachings herein, the procedure illustrated in example 1500 may be readily combined with the procedure illustrated in example 1400.Docket No.: 24-3067PCT

[0145] Example 1500 may begin with AP 1402 transmitting a frame 1502. Frame 1502 comprises a first indication of whether NPCA operation is enabled in the BSS. Frame 1502 may comprise an association response frame, a reassociation response frame, a probe response frame, a beacon frame, a management frame, an action frame, or a control frame. In an embodiment, frame 1502 comprises a first field set to a first value (e.g., 1) or to a second value (e.g. 0) to indicate whether AP 1402 enables / disables NPCA operation. In an example, the first field set to the first value may indicate that AP 1402 enables NPCA operation. In an example, the first field set to the second value may indicate that AP 1402 disables NPCA operation. In example 1400, the first field for AP 1402 is set to the first value. In an embodiment, frame 1502 comprises a UHR Operation element comprising the first field. In an embodiment, the UHR Operation element comprises a UHR Operation Parameters field, which comprises the first field. In an embodiment, the first field comprises an “NPCA Operation Information Present” field. In an embodiment, frame 1502 further indicates a time period during which NPCA operation is enabled / disabled. For example, frame 1502 may indicate a start time for the enabling / disabling of NPCA operation and / or an end time for the enabling / disabling of NPCA operation.

[0146] In example 1500, it is assumed that STAs 1404 and 1406 support a first NCPA mode of operation. In an embodiment, STA 1404 (or STA 1406) supporting the first NPCA mode of operation comprises STA 1404 (or STA 1406) being capable of operating according to the first NPCA mode of operation. In an embodiment, STA 1404 (or STA 1406) supporting the first NPCA mode of operation comprises (implicitly indicates) STA 1404 (or STA 1406) enabling / activating the first NPCA mode of operation. In an embodiment, according to the first NPCA mode of operation, STA 1404 (or STA 1406) switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In example 1500, it is assumed that AP 1402 supports a second NPCA mode of operation. AP 1402 supporting the second NPCA mode of operation comprises AP 1402 being capable of operating according to the second NCPA mode of operation. In an embodiment, AP 1402 supporting the second NPCA mode of operation comprises (implicitly indicates) AP 1402 enabling / activating the second NPCA mode of operation. In an embodiment, the second NPCA mode of operation is the same as the first NPCA mode of operation; that is, AP 1402 and STAs 1404 and 1406 support the same NPCA mode of operation. In another embodiment, the second NPCA mode of operation is different than the first NPCA mode of operation; that is, AP 1402 and STAs 1404 and 1406 support different NPCA modes of operations, e.g., AP 1402 and STAs 1404 and 1406 may switch from the PCH to the NPCA PCH based on different conditions (e.g., in addition to detecting / receiving an inter-BSS PPDU on the PCH). In an example, transmission of frame 1502 by AP 1402 may be preceded by the transmission by AP 1402 of a frame indicating support of the second NPCA mode of operation, similar to frame 1410 or 1414 described above, by the transmission of STA 1404 of a frame indicating support of the first NPCA mode of operation, similar to frame 1408 described above, and by the transmission by STA 1406 of a frame indicating support of the first NPCA mode of operation, similar to frame 1412 described above.Docket No.: 24-3067PCT

[0147] In an example, STA 1404 may transmit on the PCH a frame 1504 comprising a second indication regarding enabling / activating by STA 1404 of the first NPCA mode of operation. Frame 1504 may comprise an association request frame, a reassociation request frame, a probe request frame, a control frame, a management frame, an action frame, a Quality of Service (QoS) Null frame, or a QoS data frame. In an embodiment, where frame 1504 comprises the QoS Null frame or the QoS data frame, frame 1504 comprises an Aggregated Control (A-Control) field comprising the second indication.

[0148] In an embodiment, the second indication indicates whether STA 1404 enables / activates the first NPCA mode of operation. In an embodiment, STA 1404 enabling / activating the first NPCA mode of operation comprises (or implicitly indicates) STA 1404 supporting the first NPCA mode of operation. In an implementation, frame 1504 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, STA 1404 may set the NPCA Operation Information Present field to 1 to indicate enabling / activating of the first NPCA mode of operation. In an embodiment, frame 1504 further indicates a time period during which STA 1404 enables / disables the first NPCA mode of operation. For example, frame 1504 may indicate a start time for the enabling / disabling of the first NPCA mode of operation and / or an end time for the enabling / disabling of the first NPCA mode of operation.

[0149] In an example, STA 1406 may transmit on the PCH a frame 1506 comprising a third indication regarding enabling / activating by STA 1406 of the first NPCA mode of operation. Frame 1506 may comprise an association request frame, a reassociation request frame, a probe request frame, a control frame, a management frame, an action frame, a Quality of Service (QoS) Null frame, or a QoS data frame. In an embodiment, where frame 1506 comprises the QoS Null frame or the QoS data frame, frame 1506 comprises an Aggregated Control (A-Control) field comprising the third indication.

[0150] In an embodiment, the third indication indicates whether STA 1406 enables / activates the first NPCA mode of operation. In an embodiment, STA 1406 enabling / activating the first NPCA mode of operation comprises (or implicitly indicates) STA 1406 supporting the first NPCA mode of operation. In an implementation, frame 1506 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, STA 1406 may set the NPCA Operation Information Present field to 1 to indicate enabling / activating of the first NPCA mode of operation. In an embodiment, frame 1506 further indicates a time period during which STA 1406 enables / disables the first NPCA mode of operation. For example, frame 1506 may indicate a start time for the enabling / disabling of the first NPCA mode of operation and / or an end time for the enabling / disabling of the first NPCA mode of operation.

[0151] In an embodiment, AP 1402, STA 1404, and / or STA 1406 may be configured to determine whether to switch (or to switch) from the PCH to the NPCA PCH based on the first indication, the second indication, and / or the third indication.Docket No.: 24-3067PCT

[0152] In an embodiment, AP 1402 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the first indication indicating that AP 1402 enables / activates the second NPCA mode of operation. In another embodiment, AP 1402 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the first indication indicating that AP 1402 does not enable / activate the second NPCA mode ofoperation. The first indication may correspond to a last transmitted first indication byAP 1402. For example, in example 1500, the first indication may be the first indication comprised in frame 1502.

[0153] In an embodiment, AP 1402 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on: the second indication indicating that STA 1404 enables / activates the first NPCA mode of operation or the third indication indicating that STA 1406 enables / activates the first NPCA mode of operation. That is, AP 1402 may switch from the PCH to the NPCA PCH if at least one STA associated therewith enables / activates the first NPCA mode of operation. Conversely, AP 1402 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on: the second indication indicating that STA 1404 does not enable / activate the first NPCA mode of operation and the third indication indicating that STA 1406 does not enable / activate the first NPCA mode of operation. That is, AP 1402 may not switch from the PCH to the NPCA PCH if all STAs associated therewith (and which support NPCA operation) do not enable / activate the first NPCA mode of operation. In an embodiment, AP 1402 may not switch from the PCH to the NPCA PCH if 1) all STAs associated therewith (and which support NPCA operation) do not enable / activate the first NPCA mode of operation and / or 2) there is at least STA, associated with AP 1402, that is either a pre-UHR (or legacy) STA or a UHR STA that does not support NPCA operation In another embodiment, AP 1402 may ( / shall / does / decides to) not switch from the PCH to the NPCA PCH, for the purpose of transmission / communication on the NPCA PCH, if 1) all STAs associated therewith (and which support NPCA operation) do not enable / activate the first NPCA mode of operation and / or 2) there is at least STA, associated with AP 1402, that is either a pre-UHR (or legacy) STA or a UHR STA that does not support NPCA operation. In another embodiment, AP 1402 may ( / shall / does / decides to) not initiate a transmission on the NPCA PCH (e.g., to an NPCA non-AP STA) if 1) all STAs associated therewith (and which support NPCA operation) do not enable / activate the first NPCA mode of operation and / or 2) there is at least STA, associated with AP 1402, that is either a pre-UHR (or legacy) STA or a UHR STA that does not support NPCA operation. For example, AP 1402 may ( / shall / does / decides to) switch from the PCH to the NPCH (e.g., for channel monitoring purposes) but may not initiate a transmission on the NPCA PCH when the above conditions are satisfied.

[0154] In an embodiment, AP 1402 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the first indication indicating that AP 1402 enables / activates the second NPCA mode of operation and: the first indication indicating that STA 1404Docket No.: 24-3067PCTenables / activates the first NPCA mode of operation or the third indication indicating that STA 1406 enables / activates the first NPCA mode of operation. The first indication may correspond to a last transmitted first indication by AP 1402. For example, in example 1500, the first indication may be the first indication comprised in frame 1502.

[0155] In an embodiment, AP 1402 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on: the second indication indicating that STA 1404 enables / activates the first NPCA mode of operation and the third indication indicating that STA 1406 enables / activates the first NPCA mode of operation. That is, AP 1402 may switch from the PCH to the NPCA PCH if all STAs associated therewith enable / activate the first NPCA mode of operation. Conversely, AP 1402 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on: the second indication indicating that STA 1404 does not enable / activate the first NPCA mode of operation or the third indication indicating that STA 1406 does not enable / activate the first NPCA mode of operation. That is, AP 1402 may not switch from the PCH to the NPCA PCH if at least one of the STAs associated therewith does not enable / activate the first NPCA mode of operation.

[0156] In an embodiment, AP 1402 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the first indication indicating that AP 1402 enables / activates the second NPCA mode of operation and: the second indication indicating that STA 1404 enables / activates the first NPCA mode of operation and the third indication indicating that STA 1406 enables / activates the first NPCA mode of operation. The first indication may correspond to a last transmitted first indication by AP 1402. For example, in example 1500, the first indication may be the first indication comprised in frame 1502.

[0157] In an embodiment, STA 1404 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the second indication indicating that STA 1404 enables / activates the first NPCA mode of operation. In another embodiment, STA 1404 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the second indication indicating that STA 1404 does not enable / activate the first NPCA mode of operation.

[0158] In an embodiment, STA 1404 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the second indication indicating that STA 1404 enables / activates the first NPCA mode of operation and the first indication indicating that AP 1402 enables / activates the second NPCA mode of operation. In another embodiment, STA 1404 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the second indication indicating that STA 1404 disables / deactivates the first NPCA mode of operation or the first indication indicating that AP 1402 disables / deactivates the second NPCADocket No.: 24-3067PCTmode of operation. The first indication may correspond to a last transmitted first indication by AP 1402. For example, in example 1500, the first indication may be the first indication comprised in frame 1502.

[0159] In an embodiment, STA 1404 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the second indication indicating that STA 1404 enables / activates the first NPCA mode of operation and the third indication indicating that STA 1406 supports the first NPCA mode of operation. For example, due to a FTP link with STA 1406, STA 1404 may switch from the PCH to the NPCA PCH only when STA 1406 enables / activates the first NPCA mode of operation.

[0160] In an embodiment, STA 1406 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the third indication indicating that STA 1406 enables / activates the first NPCA mode of operation. In another embodiment, STA 1406 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the third indication indicating that STA 1406 does not enable / activate the first NPCA mode of operation.

[0161] In an embodiment, STA 1406 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the third indication indicating that STA 1406 enables / activates the first NPCA mode of operation and the first indication indicating that AP 1402 enables / activates the second NPCA mode of operation. In another embodiment, STA 1406 may be configured not to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the third indication indicating that STA 1406 disables / deactivates the first NPCA mode of operation or the first indication indicating that AP 1402 disables / deactivates the second NPCA mode of operation. The first indication may correspond to a last transmitted first indication byAP 1402. For example, in example 1400, the first indication may be the first indication comprised in frame 1502.

[0162] In an embodiment, STA 1406 may be configured to switch from the PCH to the NPCA PCH in response to detecting / receiving an inter-BSS PPDU on the PCH, based on the third indication indicating that STA 1406 enables / activates the first NPCA mode of operation and the second indication indicating that STA 1404 enables / activates the first NPCA mode of operation. For example, due to a PTP link with STA 1404, STA 1406 may switch from the PCH to the NPCA PCH only when STA 1404 enables / activates the first NPCA mode of operation.

[0163] In another embodiment, the second indication (or the third indication) comprises a request by STA 1404 (or STA 1406) to enable / disable the first NPCA mode of operation. AP 1402 may respond to frame 1504 (or frame 1506) by transmitting to STA 1404 (or STA 1406) a frame (not shown in FIG. 15) comprising a fourth indication accepting or rejecting the request.Docket No.: 24-3067PCT

[0164] In an embodiment, the switching from the PCH to the NPCA PCH based on the second indication by STA 1404 (or based on the third indication by STA 1406) comprises switching from the PCH to the NPCA PCH based on the second indication (or the third indication) and the fourth indication.

[0165] In an embodiment, the switching from the PCH to the NPCA PCH based on the second indication by STA 1404 (or based on the third indication by STA 1406) and the fourth indication comprises switching from the PCH to the NPCA PCH based on the second indication comprising a request by STA 1404 (or the third indication comprising a request by STA 1406) to enable the first NPCA mode of operation and the fourth indication accepting the request.

[0166] In an embodiment, the switching from the PCH to the NPCA PCH based on the second indication by STA 1404 (or based on the third indication by STA 1406) and the fourth indication comprises switching from the PCH to the NPCA PCH based on the second indication comprising a request by STA 1404 (or the third indication comprising a request by STA 1406) to disable the first NPCA mode of operation and the fourth indication rejecting the request.

[0167] In an embodiment, the switching from the PCH to the NPCA PCH based on the second indication by STA 1404 (or based on the third indication by STA 1406) and the fourth indication comprises not switching from the PCH to the NPCA PCH based on the second indication comprising a request by STA 1404 (or the third indication comprising a request by STA 1406) to enable the first NPCA mode of operation and the fourth indication rejecting the request.

[0168] In an embodiment, the switching from the PCH to the NPCA PCH based on the second indication by STA 1404 (or based on the third indication by STA 1406) and the fourth indication comprises not switching from the PCH to the NPCA PCH based on the second indication comprising a request by STA 1404 (or the third indication comprising a request by STA 1406) to disable the first NPCA mode of operation and the fourth indication accepting the request.

[0169] In another example (not shown in FIG. 15), AP 1402 may not transmit frame 1502 to indicate enabling / activating of NPCA operation in the BSS. Instead, AP 1402 may transmit a frame similar to frame 1410 or frame 1414 indicating support of the second NPCA mode of operation. The transmission of such a frame implicitly indicates enabling / activating of NPCA operation in the BSS. AP 1402 may transmit a further frame to disable NPCA operation in the BSS, which is assumed enabled otherwise. Alternatively, despite AP 1402 transmitting a frame indicating support of the second NPCA mode of operation, NPCA operation is not considered enabled / activated in the BSS. To enable / activate NPCA operation in the BSS, AP 1402 transmits a frame such as frame 1502.

[0170] In another example (not shown in FIG. 15), STA 1404 may not transmit frame 1504 to indicate enabling / activating of the first NPCA mode of operation by STA 1404. Instead, STA 1404 may transmit a frame similar to frame 1408 indicating support of the first NPCA mode of operation by STA 1404. The transmission of such a frame implicitly indicates enabling / activating of the first NPCA mode of operation byDocket No.: 24-3067PCTSTA 1404. STA 1404 may transmit a further frame to disable the first NPCA mode of operation, which is assumed to be enabled / activated otherwise. Alternatively, despite STA 1404 transmitting a frame indicating support of the first NPCA mode of operation, NPCA operation is not considered enabled / activated at STA 1404. To enable / activate NPCA operation, STA 1404 transmits a frame such as frame 1504. In another example,

[0171] In another example (not shown in FIG. 15), STA 1406 may not transmit frame 1506 to indicate disabling / deactivating the first NPCA mode of operation. Instead, STA 1406 may transmit a frame similar to frame 1412 indicating non-support of the first NPCA mode of operation. The transmission of such a frame implicitly indicates disabling / deactivating of the first NPCA mode of operation by STA 1406. STA 1406 may transmit a further frame to enable the first NPCA mode of operation, which is assumed to be disabled / deactivated otherwise. Alternatively, STA 1406 may disable the first NPCA mode of operation without transmitting any frame. For example, STA 1406 may disable the first NPCA mode of operation due to a scheduled unavailability period or due to a scheduled power saving mode operation (e.g., doze state, low-power capability mode, etc.). AP 1402 may or may not be aware of the scheduled unavailability period or the scheduled power saving mode operation.

[0172] In example 1500, the first indication in frame 1502 indicates that AP 1402 enables / activates the second NPCA mode of operation at AP 1402 (or NPCA operation in the BSS). For example, AP 1402 may enable / activate the second NPCA mode of operation at AP 1402 based on having low latency traffic (e.g., traffic associated with a particular TID) and / or high priority traffic (e.g., AC_VI or AC_VO) buffered for transmission to associated STA(s). In another example, AP 1402 may enable / activate the second NPCA mode of operation at AP 1402 based on STA 1404 or STA 1406 indicating support / enabling of the first NPCA mode of operation.

[0173] In example 1500, the second indication in frame 1504 indicates that STA 1404 enables / activates the first NPCA mode of operation. For example, STA 1404 may have low latency traffic (e.g., traffic associated with a particular TID) and / or high priority traffic (e.g., AC_VI or AC_VO) arrive for transmission to AP 1402. STA 1404 may determine that enabling / activating NPCA operation increases the chance of a timely transmission of the low latency traffic and / or the high priority traffic. In another example, STA 1404 may have a PTP link with another STA that has enabled / activated NPCA operation. To maintain the link with the other STA when the other STA switches to the NPCA PCH, STA 1404 may determine to enable / activate NPCA operation.

[0174] In example 1500, the third indication in frame 1506 indicates that STA 1406 disables / deactivates the first NPCA mode of operation. For example, STA 1404 may not have low latency traffic and / or high priority traffic for transmission that would justify the increased power consumption associated with NPCA operation. In another example, STA 1404 may wish to save power by reducing channel switching operations.Docket No.: 24-3067PCT

[0175] In example 1500, AP 1402 may be configured to switch from the PCH to the NCPA PCH based on AP 1402 enabling the second NPCA mode of operation and at least one STA associated with AP 1402 enabling the first NPCA mode of operation. STA 1404 (or STA 1406) may be configured to switch from the PCH to the NPCA PCH based on STA 1404 (or STA 1406) enabling the first NPCA mode of operation. As such, as shown in FIG. 15, AP 1402 and STA 1404 switch from the PCH to the NPCA PCH on detecting / receiving inter-BSS PPDU 1508 on the PCH. In contrast, STA 1406 does not switch from the PCH to the NPCA PCH on detecting / receiving inter-BSS PPDU 1508 and remains on the PCH.

[0176] After switching to the NPCA PCH, AP 1402 may gain control of the NPCA PCH and (knowing that STA 1404 also switched to the NPCA PCH) transmits an ICF 1510 to STA 1404. STA 1404 may respond to ICF 1510 by transmitting an ICR 1512 to AP 1402. Subsequently, AP 1402 may transmit a data frame 1514 to STA 1404, and STA 1404 may respond with a BA frame 1516 to AP 1402. AP 1402 and STA 1404 may return to the PCH at / before an end of a NAV duration determined from inter-BSS PPDU 1508.

[0177] FIG. 16 shows an example 1600 of another operation according to an embodiment. Example 1600 is provided for the purpose of illustration only and is not limiting of embodiments. As shown in FIG. 16, example 1600 also includes AP 1402 and STAs 1404 and 1406 described in FIG. 14 above. STAs 1404 and 1406 may be associated with AP 1402 and may therefore belong to the same BSS as AP 1402.

[0178] As shown in FIG. 16, example 1600 begins with STA 1404 transmitting to AP 1402 frame 1408 (described above in FIG. 14) and AP 1402 responding with frame 1410 (described above in FIG. 14). As described above, frame 1408 comprises a first indication of whether STA 1404 supports a first NPCA mode of operation. According to the first NPCA mode of operation, STA 1404 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. Frame 1410 comprises a second indication of whether AP 1402 supports a second NPCA mode of operation. According to the second NPCA mode of operation, AP 1402 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, the second NPCA mode of operation is the same as the first NPCA mode of operation; that is, AP 1402 and STA 1404 support the same NPCA mode of operation. In another embodiment, the second NPCA mode of operation is different than the first NPCA mode of operation; that is, AP 1402 and STA 1404 support different NPCA modes of operations, e.g., AP 1402 and STA 1404 may switch from the PCH to the NPCA PCH based on different conditions (e.g., in addition to detecting / receiving an inter-BSS PPDU on the PCH).

[0179] Subsequently, STA 1406 transmits a frame 1602 to AP 1402. Frame 1602 comprises a third indication of whether STA 1406 supports the first NPCA mode of operation. According to the first NPCA mode of operation, STA 1406 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, frame 1602 comprises an association request frame, a reassociation request frame, or a probe request frame. In an embodiment, frame 1602 comprises a first field set to a first value (e.g., 1) or to a second value (e.g. 0) to indicate whether STA 1406 supports the first NPCA mode ofDocket No.: 24-3067PCToperation. In an embodiment, frame 1602 comprise a UHR Capabilities element, which comprises the first field. In an embodiment, the UHR Capabilities element comprises a UHR MAC Capabilities Information field, which comprises the first field In an embodiment, the first field comprises an “NPCA Supported” field.

[0180] In response to frame 1602, AR 1402 may transmit a frame 1604 to STA 1406. Frame 1604 comprises the second indication of whether AR 1402 supports the second NPCA mode of operation. In an embodiment, the second NPCA mode of operation is the same as the first NPCA mode of operation; that is, AP 1402 and STA 1406 support the same NPCA mode of operation. In another embodiment, the second NPCA mode of operation is different than the first NPCA mode of operation; that is, AP 1402 and STA 1406 support different NPCA modes of operations, e.g., AP 1402 and STA 1406 may switch from the PCH to the NPCA PCH based on different conditions (e.g., in addition to detecting / receiving an inter-BSS PPDU on the PCH).

[0181] Subsequently, STA 1406 may transmit on the PCH a frame 1606 comprising a fourth indication of whether STA 1406 enables / activates the first NPCA mode of operation. Frame 1606 may comprise an association request frame, a reassociation request frame, a probe request frame, a control frame, a management frame, an action frame, a Quality of Service (QoS) Null frame, or a QoS data frame. In an embodiment, where frame 1606 comprises the QoS Null frame or the QoS data frame, frame 1606 comprises an Aggregated Control (A-Control) field comprising the third indication. In an implementation, frame 1606 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, STA 1406 may set the NPCA Operation Information Present field to 1 to indicate enabling / activating of the first NPCA mode of operation. In an embodiment, frame 1606 further indicates a time period during which STA 1406 enables / disables the first NPCA mode of operation. For example, frame 1606 may indicate a start time for the enabling / disabling of the first NPCA mode of operation and / or an end time for the enabling / disabling of the first NPCA mode of operation.

[0182] In example 1600, the first indication in frame 1408 indicates that STA 1404 supports the first NPCA mode of operation; the second indication in frame 1410 or frame 1604 indicates that AP 1402 supports the second NPCA mode of operation, the third indication in frame 1602 indicates that STA 1406 supports the first NPCA mode of operation; and the fourth indication in frame 1606 indicates that STA 1406 disables / deactivates the first NPCA mode of operation.

[0183] In example 1600, AP 1402, STA 1404, and / or STA 1406 may be configured to determine whether to switch (or to switch) from the PCH to the NPCA PCH based on the first indication, the second indication, the third indication, and / or the fourth indication. For example, AP 1402 may be configured to switch from the PCH to the NCPA PCH based on AP 1402 supporting the second NPCA mode of operation and at least one STA associated with AP 1402 enabling the first NPCA mode of operation. STA 1404 (or STA 1406) may be configured to switch from the PCH to the NPCA PCH based on STA 1404 (or STA 1406) enabling the first NPCA mode of operation.Docket No.: 24-3067PCT

[0184] In example 1600, AP 1402 may determine that a STA that supports the first NPCA mode of operation enables / activates the first NPCA mode of operation unless the STA transmits a frame disabling / deactivating the first NPCA mode of operation. As such, AP 1402 may determine that STA 1404 enables / activates the first NPCA mode of operation and that STA 1406 disables / deactivates the first NPCA mode of operation (based on receiving frame 1606 from STA 1406). AP 1402 may thus be configured to switch from the PCH to the NPCA PCH on detecting / receiving an inter-BSS PPDU on the PCH. However, in example 1600, AP 1402 does not detect on the PCH an inter-BSS PPDU 1608, which STAs 1404 and 1406 detect. As such, AP 1402 does not switch from the PCH to the NPCA PCH in response to inter-BSS PPDU 1608. Similarly, STA 1406, which disables / deactivates the first NPCA mode of operation, does not switch from the PCH to the NPCA PCH based on detecting / receiving inter-BSS PPDU 1608. In an example, as AP 1402 is not aware of inter-BSS PPDU 1608 and does not set a basic NAV based on inter-BSS PPDU 1608 for the PCH, AP 1402 may communicate with STA 1406 on the PCH. For example, AP 1402 may transmit a data frame 1610 to STA 1406 on the PCH. STA 1406 may respond with a BA frame 1612 to AP 1402 on the PCH (despite setting a basic NAV based on inter-BSS PPDU 1608 for the PCH, as STA 1406 does not check the basic NAV for transmitting a BA frame).

[0185] STA 1404, which enables / activates the first NPCA mode of operation, switches from the PCH to the NPCA PCH based on detecting / receiving inter-BSS PPDU 1608. As AP 1402 with which STA 1404 is associated does not switch to the NPCA PCH, STA 1404 may not communicate on the NPCA PCH after switching to the NPCA PCH. In another example, STA 1404 may communicate on the NPCA PCH with another STA (not shown in FIG. 16) with which STA 1404 has a PTP link (assuming that the other STA also switches from the PCH to the NPCA PCH based on inter-BSS PPDU 1608). STA 1404 may return to the PCH at / before the end of a NAV duration determined from inter-BSS PPDU 1608.

[0186] FIG. 17 illustrates an example process 1700 according to an embodiment. Example process 1700 is provided for the purpose of illustration only and is not limiting of embodiments. Example process 1700 may be performed by a first STA, such as STA 1404 or STA 1406, for example. As shown in FIG. 17, example process 1700 may include steps 1702 and 1704.

[0187] Step 1702 includes transmitting, by the first STA to an AP, a first frame comprising a first indication regarding enabling / activating by the first STA of a first NPCA) mode of operation. In an embodiment, the first STA is associated with the AP.

[0188] Step 1704 includes determining whether to switch or switching, by the STA, from a PCH to an NPCA PCH based on the first indication.

[0189] In an embodiment, the first indication indicates whether the first STA enables / activates the first NPCA mode of operation.Docket No.: 24-3067PCT

[0190] In an embodiment, the first indication comprises a request by the first STA to enable / disable the first NPCA mode of operation. In an embodiment, process 1700 may further comprise receiving, by the first STA from the AP, a second frame comprising a second indication accepting or rejecting the request.

[0191] In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication in step 1704 comprises switching from the PCH to the NPCA PCH based on the first indication and the second indication. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises switching from the PCH to the NPCA PCH based on the first indication comprising a request by the first STA to enable the first NPCA mode of operation and the second indication accepting the request. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises switching from the PCH to the NPCA PCH based on the first indication comprising a request by the first STA to disable the first NPCA mode of operation and the second indication rejecting the request. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises not switching from the PCH to the NPCA PCH based on the first indication comprising a request by the first STA to enable the first NPCA mode of operation and the second indication rejecting the request. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises not switching from the PCH to the NPCA PCH based on the first indication comprising a request by the first STA to disable the first NPCA mode of operation and the second indication accepting the request.

[0192] In an embodiment, the first STA enabling / activating the first NPCA mode of operation comprises the first STA supporting the first NPCA mode of operation.

[0193] In an embodiment, in the first NPCA mode of operation, the first STA switches from the PCH to the NPCA PCH based on detecting / receiving a first inter-BSS PPDU on the PCH.

[0194] In an embodiment, the first frame comprises an association request frame, a reassociation request frame, a probe request frame, a control frame, a management frame, an action frame, a Quality of Service (QoS) Null frame, or a QoS data frame. In an embodiment, where the first frame comprises the QoS Null frame or the QoS data frame, the first frame comprises an Aggregated Control (A-Control) field comprising the first indication.

[0195] In an embodiment, the AP supports / enables a second NPCA mode of operation, in which the AP switches from the PCH to the NPCA PCH based on detecting a second inter-BSS PPDU on the PCH. In an embodiment, the second NPCA mode of operation is the same as the first NPCA mode of operation. In another embodiment, the second NPCA mode of operation is different than the first NPCA mode of operation.

[0196] In an embodiment, process 1700 further comprise transmitting, by the first STA to the AP and via the PCH, a third frame indicating that the first STA supports the first NPCA mode of operation. In an embodiment, the third frame comprises an association request frame, a reassociation request frame, a probe request frame, a management frame, an action frame, or a control frame. In an embodiment, the third frameDocket No.: 24-3067PCTcomprises a first field set to 1 to indicate that the first STA supports the first NPCA mode of operation. In an embodiment, the third frame comprises an ultra-high reliability (UHR) Capabilities element, and the UHR Capabilities element comprises the first field. In an embodiment, the UHR Capabilities element comprises a UHR medium access control (MAC) Capabilities Information field, and the UHR MAC Capabilities Information field comprises the first field. In an embodiment, the first field comprises an "NPCA Supported” field.

[0197] In an embodiment, process 1700 further comprises receiving, by the first STA from the AP, a fourth frame indicating that the AP supports the second NPCA mode of operation. In an embodiment, the fourth frame comprises an association response frame, a reassociation response frame, a probe response frame, a beacon frame, a management frame, an action frame, or a control frame. In an embodiment, the fourth frame comprises a second field set to 1 to indicate that the AP supports the second NPCA mode of operation. In an embodiment, the fourth frame comprises an ultra-high reliability (UHR) Capabilities element, and the UHR Capabilities element comprises the second field In an embodiment, the UHR Capabilities element comprises a UHR medium access control (MAC) Capabilities Information field, and the UHR MAC Capabilities Information field comprises the second field. In an embodiment, the second field comprises an "NPCA Supported" field.

[0198] In an embodiment, process 1700 further comprises receiving, by the first STA from the AP, a fifth frame indicating enabling, by the AP, of the second NPCA mode of operation. In an embodiment, the fifth frame comprises an association response frame, a reassociation response frame, a probe response frame, a beacon frame, a management frame, an action frame, or a control frame. In an embodiment, the fifth frame comprises a third field set to 1 to indicate that the AP enables the second NPCA mode of operation. In an embodiment, the fifth frame comprises an ultra-high reliability (UHR) Operation element, and the UHR Operation element comprises the third field. In an embodiment, the UHR Operation element comprises a UHR Operation Parameters field, and the UHR Operation Parameters field comprises the third field. In an embodiment, the third field comprises an “NPCA Operation Information Present” field.

[0199] FIG. 18 illustrates an example process according to an embodiment. Example process 1800 is provided for the purpose of illustration only and is not limiting of embodiments. Example process 1800 may be performed by an AP, such as AP 1402, for example. As shown in FIG. 18, example process 1800 may include steps 1802 and 1804.

[0200] Step 1802 includes receiving, by the AP from a first STA, a first frame comprising a first indication of whether the first STA enables / activates a first non-primary channel access (NPCA) mode of operation. In an embodiment, the first STA is associated with the AP.

[0201] Step 1804 includes determining whether to switch or switching, by the AP, from a PCH to an NPCA PCH based on the first indication.

[0202] In an embodiment, the first STA enabling / activating the first NPCA mode of operation comprises the first STA supporting the first NPCA mode of operation. In an embodiment, in the first NPCA mode ofDocket No.: 24-3067PCToperation, the first STA switches from the PCH to the NPCA PCH based on detecting / receiving a first inter-basic service set (BSS) physical layer protocol data unit (PPDU) on the PCH.

[0203] In an embodiment, the first frame comprises an association request frame, a reassociation request frame, a probe request frame, a control frame, a management frame, an action frame, a Quality of Service (QoS) Null frame, or a QoS data frame. In an embodiment, where the first frame comprises the QoS Null frame or the QoS data frame, the first frame comprises an Aggregated Control (A-Control) field comprising the first indication.

[0204] In an embodiment, the AP supports / enables a second NPCA mode of operation, in which the AP switches from the PCH to the NPCA PCH based on detecting a second inter-BSS PPDU on the PCH.

[0205] In an embodiment, process 1800 further comprises determining, by the AP, that a PPDU being received via the PCH comprises a third inter-BSS PPDU. In an embodiment, where the first indication indicates that the first STA enables / activates the first NPCA mode of operation, the switching from the PCH to the NPCA PCH based on the first indication in step 1802 comprises switching from the PCH to the NPCA PCH based on the determining that the PPDU being received via the PCH comprises the third inter-BSS PPDU. In an embodiment, where the first indication indicates that the first STA disables / deactivates the first NPCA mode of operation, the switching from the PCH to the NPCA PCH based on the first indication in step 1802 comprises not switching from the PCH to the NPCA PCH based on the determining that the PPDU being received via the PCH comprises the third inter-BSS PPDU.

[0206] In an embodiment, process 1800 further comprises receiving, by the AP from a second STA, a second frame comprising a second indication of whether the second STA enables / activates the first NPCA mode of operation. In an embodiment, the second STA is associated with the AP. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication in step 1802 comprises switching from the PCH to the NPCA PCH based on the first indication and the second indication. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises switching from the PCH to the NPCA PCH based on the first indication indicating that the first STA enables / activates the first NPCA mode of operation or the second indication indicating that the second STA enables / activates the first NPCA mode of operation. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises not switching from the PCH to the NPCA PCH based on the first indication indicating that the first STA disables / deactivates the first NPCA mode of operation and the second indication indicating that the second STA disables / deactivates the first NPCA mode of operation. In such an embodiment, a basic service set (BSS) of the AP may comprise the first STA and the second STA only. In another embodiment, the BSS may further comprise at least one STA that is either a pre-UHR (legacy) STA or a UHR STA that does not support NPCA operation (i.e., at least one STA that is either a pre-UHR (legacy) STA or a UHR STA that does not support NPCA operation is associatedDocket No.: 24-3067PCTwith the AP). In such an embodiment, the not switching from the PCH to the NPCA PCH may further be based on the at least one STA being associated with the AP.

[0207] In an embodiment, process 1800 further comprises receiving, by the AP from the first STA and via the PCH, a third frame indicating that the first STA supports the first NPCA mode of operation. In an embodiment, the third frame comprises an association request frame, a reassociation request frame, a probe request frame, a management frame, an action frame, or a control frame. In an embodiment, the third frame comprises a first field set to 1 to indicate that the first STA supports the first NPCA mode of operation. In an embodiment, the third frame comprises an ultra-high reliability (UHR) Capabilities element, and the UHR Capabilities element comprises the first field. In an embodiment, the UHR Capabilities element comprises a UHR medium access control (MAC) Capabilities Information field, and the UHR MAC Capabilities Information field comprises the first field. In an embodiment, the first field comprises an “NPCA Supported" field.

[0208] In an embodiment, process 1800 further comprises transmitting, by the AP to the first STA, a fourth frame indicating that the AP supports a second NPCA mode of operation, in which the AP switches from the PCH to the NPCA PCH based on detecting a second inter-BSS PPDU on the PCH. In an embodiment, the fourth frame comprises an association response frame, a reassociation response frame, a probe response frame, a beacon frame, a management frame, an action frame, or a control frame. In an embodiment, the fourth frame comprises a second field set to 1 to indicate that the AP supports the second NPCA mode of operation. In an embodiment, the fourth frame comprises an ultra-high reliability (UHR) Capabilities element, and the UHR Capabilities element comprises the second field. In an embodiment, the UHR Capabilities element comprises a UHR medium access control (MAC) Capabilities Information field, and the UHR MAC Capabilities Information field comprises the second field. In an embodiment, the second field comprises an “NPCA Supported” field.

[0209] In an embodiment, process 1800 further comprises transmitting, by the AP, a fifth frame indicating enabling, by the AP, of the second NPCA mode of operation. In an embodiment, the fifth frame comprises an association response frame, a reassociation response frame, a probe response frame, a beacon frame, a management frame, an action frame, or a control frame. In an embodiment, the fifth frame comprises a third field set to 1 to indicate that the AP enables the second NPCA mode of operation. In an embodiment, the fifth frame comprises an ultra-high reliability (UHR) Operation element, and the UHR Operation element comprises the third field. In an embodiment, the UHR Operation element comprises a UHR Operation Parameters field, and the UHR Operation Parameters field comprises the third field. In an embodiment, the third field comprises an “NPCA Operation Information Present” field.

[0210] FIG. 19 illustrates an example process according to an embodiment. Example process 1900 is provided for the purpose of illustration only and is not limiting of embodiments. Example process 1900 may be performed by a first STA, such as STA 1404 or STA 1406, for example. As shown in FIG. 19, example process 1900 may include steps 1902 and 1904.Docket No.: 24-3067PCT

[0211] Step 1902 includes transmitting, by the first STA to an AP, a first frame comprising a first indication of whether the first STA supports a first NPCA mode of operation. In an embodiment, the first STA is associated with the AP.

[0212] Step 1904 includes determining whether to switch or switching, by the STA, from a PCH to an NPCA PCH based on the first indication.

[0213] In an embodiment, the first STA supporting the first NPCA mode of operation comprises the first STA being capable of operating according to the first NPCA mode of operation. In an embodiment, the first STA supporting the first NPCA mode of operation comprises the first STA enabling / activating the first NPCA mode of operation. In an embodiment, in the first NPCA mode of operation, the first STA switches from the PCH to the NPCA PCH based on detecting / receiving a first inter-BSS PPDU on the PCH.

[0214] In an embodiment, the first frame comprises an association request frame, a reassociation request frame, or a probe request frame. In an embodiment, the first frame comprises a first field set to 1 to indicate that the first STA supports the first NPCA mode of operation. In an embodiment, the first frame comprises an ultra-high reliability (UHR) Capabilities element, and the UHR Capabilities element comprises the first field. In an embodiment, the UHR Capabilities element comprises a UHR medium access control (MAC) Capabilities Information field, and the UHR MAC Capabilities Information field comprises the first field. In an embodiment, the first field comprises an “NPCA Supported” field.

[0215] In an embodiment, process 1900 further comprises determining, by the first STA, that a PPDU being received via the PCH comprises a second inter-BSS PPDU. In an embodiment, the first indication indicates that the first STA supports the first NPCA mode of operation, and the switching from the PCH to the NPCA PCH based on the first indication in step 1904 comprises switching from the PCH to the NPCA PCH based on the determining that the PPDU being received via the PCH comprises the second inter-BSS PPDU. In an embodiment, where the first indication indicates that the first STA does not support the first NPCA mode of operation, the switching from the PCH to the NPCA PCH based on the first indication in step 1904 comprises not switching from the PCH to the NPCA PCH based on the determining that the PPDU being received via the PCH comprises the second inter-BSS PPDU.

[0216] In an embodiment, process 1900 further comprises receiving, by the first STA from the AP, a second frame comprising a second indication of whether the AP supports a second NPCA mode of operation. In an embodiment, when the AP supports the second NPCA mode of operation, the AP switches from the PCH to the NPCA PCH based on detecting a third inter-BSS PPDU on the PCH. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication in step 1904 comprises switching from the PCH to the NPCA PCH based on the first indication and the second indication. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises switching from the PCH to the NPCA PCH based on the first indication indicating that the first STA supports the first NPCA mode of operation and the second indication indicating that the AP supports the second NPCA modeDocket No.: 24-3067PCTof operation. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises not switching from the PCH to the NPCA PCH based on the first indication indicating that the first STA does not support the first NPCA mode of operation or the second indication indicating that the AP does not support the second NPCA mode of operation.

[0217] FIG. 20 illustrates an example process according to an embodiment. Example process 2000 is provided for the purpose of illustration only and is not limiting of embodiments. Example process 2000 may be performed by an AP, such as AP 1402, for example. As shown in FIG. 20, example process 2000 may include steps 2002 and 2004.

[0218] Step 2002 includes receiving, by the AP from a first STA, a first frame comprising a first indication of whether the first STA supports a first NPCA mode of operation. In an embodiment, the first STA is associated with the AP.

[0219] Step 2004 includes determining whether to switch or switching, by the AP, from a PCH to an NPCA PCH based on the first indication.

[0220] In an embodiment, the first STA supporting the first NPCA mode of operation comprises the first STA being capable of operating according to the first NPCA mode of operation. In an embodiment, the first STA supporting the first NPCA mode of operation comprises the first STA enabling / activating the first NPCA mode of operation. In an embodiment, in the first NPCA mode of operation, the first STA switches from the PCH to the NPCA PCH based on detecting / receiving a first inter-BSS PPDU on the PCH.

[0221] In an embodiment, the first frame comprises an association request frame, a reassociation request frame, or a probe request frame. In an embodiment, the first frame comprises a first field set to 1 to indicate that the first STA supports the first NPCA mode of operation In an embodiment, the first frame comprises an ultra-high reliability (UHR) Capabilities element, and the UHR Capabilities element comprises the first field. In an embodiment, the UHR Capabilities element comprises a UHR medium access control (MAC) Capabilities Information field, and the UHR MAC Capabilities Information field comprises the first field. In an embodiment, the first field comprises an “NPCA Supported” field.

[0222] In an embodiment, the AP supports / enables a second NPCA mode of operation, in which the AP switches from the PCH to the NPCA PCH based on detecting a second inter-BSS PPDU on the PCH.

[0223] In an embodiment, process 2000 further comprises determining, by the AP, that a PPDU being received via the PCH comprises a third inter-BSS PPDU. In an embodiment, where the first indication indicates that the first STA supports the first NPCA mode of operation, the switching from the PCH to the NPCA PCH based on the first indication in step 2004 comprises switching from the PCH to the NPCA PCH based on the determining that the PPDU being received via the PCH comprises the third inter-BSS PPDU. In an embodiment, where the first indication indicates that the first STA does not support the first NPCA mode of operation, the switching from the PCH to the NPCA PCH based on the first indication in step 2004Docket No.: 24-3067PCTcomprises not switching from the PCH to the NPCA PCH based on the determining that the PPDU being received via the PCH comprises the third inter-BSS PPDU.

[0224] In an embodiment, process 2000 further comprises receiving, by the AP from a second STA, a second frame comprising a second indication of whether the second STA supports the first NPCA mode of operation. In an embodiment, the second STA is associated with the AP. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication comprises switching from the PCH to the NPCA PCH based on the first indication and the second indication. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises switching from the PCH to the NPCA PCH based on the first indication indicating that the first STA supports the first NPCA mode of operation or the second indication indicating that the second STA supports the first NPCA mode of operation. In an embodiment, the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises not switching from the PCH to the NPCA PCH based on the first indication indicating that the first STA does not support the first NPCA mode of operation and the second indication indicating that the second STA does not support the first NPCA mode of operation. In such an embodiment, a basic service set (BSS) of the AP may comprise the first STA and the second STA only. In another embodiment, the BSS may further comprise at least one pre-UHR (legacy) STA (i.e., at least one pre-UHR (legacy) STA is associated with the AP). In such an embodiment, the not switching from the PCH to the NPCA PCH may further be based on the at least one pre-UHR (legacy) STA being associated with the AP.

[0225] In an embodiment, a STA (e.g., an AP or non-AP STA) described in any of the embodiments above may further perform one or more of the NPCA operations described herein below. As would be understood by a person of skill in the art based on the teachings, any of the NPCA operations described below may be combined with the procedures / operations described above. For example, a STA (e.g., an AP or non-AP STA) described above in relation to FIGS. 14-20 may switch to the NPCA primary channel for NPCA operation if either condition 1) or 2), described below, is met.

[0226] Hereinafter, a STA that supports NPCA operation is called an NPCA STA. An AP that supports NPCA operation is called an NPCA AP. 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.

[0227] 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 sameDocket No.: 24-3067PCTNPCA switch back delay as all of the other APs of the same co-hosted BSSs that have enabled NPCA operation.

[0228] 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.

[0229] In an implementation, an NPCA AP with a value (e.g., dotHHEPSROption Implemented) 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.

[0230] 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.

[0231] 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 may be set to 0.The NPCA Disabled Subchannel Bitmap field value may satisfy the following requirements:• The puncturing pattern indicated by the value of the NPCA Disabled Subchannel Bitmap field is a valid non-OFDMA puncturing pattern.• 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.

[0232] 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 theDocket No.: 24-3067PCTsecondary 40 MHz of the BSS operating channel if the BSS is an 80 MHz BSS, thatcorresponds 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.

[0233] 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.

[0234] 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 UHR 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.

[0235] 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.

[0236] 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 AIFSN[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 AIFSN[AC] values from the dot11 MUEDCATable.

[0237] 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.

[0238] 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.: 24-3067PCT1) 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 aSIFSTime, 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 aSIFSTime + ICR_Timeout after the MAC receives a PHY-RXEND. indication primitive corresponding to the first PPDU, where ICR_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 ofDocket No.: 24-3067PCTthe 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 the received 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.

[0239] In an implementation, when a PHY-CCA.indication(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.

[0240] 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 PHYRXSTART.indication primitives associated with the received PPDU from the value of RXTIME of the received PPDU.

[0241] 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 PHYRXSTART.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.

[0242] In an implementation, the MAC variable NPCA_CFRAME_TXOP_REM_DUR derived from a received PPDU is:Docket No.: 24-3067PCTSet 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 and the 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. indication primitive of the third PPDU.

[0243] 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.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 O, 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.Docket No.: 24-3067PCTii) 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 CW[AC] to 2lnit-QSRc_NPCAx(CWmin[AC] + 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 is switching 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. a) 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.b) 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:a) include at least the NPCA primary channel.b) all be within the BSS bandwidth.c) 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.Docket No.: 24-3067PCTd) 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 ER SU 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.

[0244] 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.

[0245] 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 QSRC[AC], CW[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.

Claims

Docket No.: 24-3067PCTCLAIMSWhat is claimed is:

1. A method comprising:receiving, by an access point (AP) from a first station (STA) and via a primary channel (PCH), an association request frame comprising an indication of whether the first STA supports a non-primary channel access (NPCA) mode of operation, wherein, in the NPCA mode of operation, the first STA switches from the PCH to an NPCA PCH based on detecting a first inter-basic service set (BSS) physical layer protocol data unit (PPDU) on the PCH;transmitting, by the AP to the first STA, an association response frame indicating that the AP supports the NPCA mode of operation, wherein in the NPCA mode of operation, the AP switches from the PCH to the NPCA PCH based on detecting a second inter-BSS PPDU on the PCH;determining, by the AP, that a PPDU being received via the PCH comprises a third inter-BSS PPDU; andswitching, by the AP, from the PCH to the NPCA PCH based on the indication and the determining.

2. A method comprising:receiving, by an access point (AP) from a first station (STA), a first frame comprising a first indication of whether the first STA supports a first non-primary channel access (NPCA) mode of operation; and switching, by the AP, from a primary channel (PCH) to a non-primary channel access (NPCA) PCH based on the first indication.

3. The method of claim 2, wherein the first STA is associated with the AP.

4. The method of any of claims 2-3, wherein the first STA supporting the first NPCA mode of operation comprises the first STA being capable of operating according to the first NPCA mode of operation.

5. The method of any of claims 2-4, wherein the first STA supporting the first NPCA mode of operation comprises the first STA enabling the first NPCA mode of operation.

6. The method of any of claims 2-5, wherein in the first NPCA mode of operation, the first STA switches from the PCH to the NPCA PCH based on detecting a first inter-basic service set (BSS) physical layer protocol data unit (PPDU) on the PCH.

7. The method of any of claims 2-6, wherein the first frame comprises an association request frame, a reassociation request frame, or a probe request frame.

8. The method of any of claims 2-7, wherein the first frame comprises a first field set to 1 to indicate that the first STA supports the first NPCA mode of operation.

9. The method of claim 8, wherein the first frame comprises an ultra-high reliability (UHR) Capabilities element, and wherein the UHR Capabilities element comprises the first field.Docket No.: 24-3067PCT10. The method of claim 9, wherein the UHR Capabilities element comprises a UHR medium access control (MAC) Capabilities Information field, and wherein the UHR MAC Capabilities Information field comprises the first field.

11. The method of any of claims 8-10, wherein the first field comprises an "NPCA Supported" field.

12. The method of any of claims 2-11 , wherein the AP supports a second NPCA mode of operation, and wherein, in the second NPCA mode of operation, the AP switches from the PCH to the NPCA PCH based on detecting a second inter-BSS PPDU on the PCH.

13. The method of any of claims 2-12, further comprising determining, by the AP, that a PPDU being received via the PCH comprises a third inter-BSS PPDU.

14. The method of claim 13, wherein the first indication indicates that the first STA supports the first NPCA mode of operation, and wherein the switching from the PCH to the NPCA PCH based on the first indication comprises switching from the PCH to the NPCA PCH based on the determining.

15. The method of claim 13, wherein the first indication indicates that the first STA does not support the first NPCA mode of operation, and wherein the switching from the PCH to the NPCA PCH based on the first indication comprises not switching from the PCH to the NPCA PCH based on the determining.

16. The method of any of claims 2-15, further comprising receiving, by the AP from a second STA, a second frame comprising a second indication of whether the second STA supports the first NPCA mode of operation, and wherein the switching from the PCH to the NPCA PCH based on the first indication comprises switching from the PCH to the NPCA PCH based on the first indication and the second indication.

17. The method of claim 16, wherein the second STA is associated with the AP.

18. The method of any of claims 16-17, wherein the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises switching from the PCH to the NPCA PCH based on the first indication indicating that the first STA supports the first NPCA mode of operation or the second indication indicating that the second STA supports the first NPCA mode of operation.

19. The method of any of claims 16-18, wherein the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises not switching from the PCH to the NPCA PCH based on the first indication indicating that the first STA does not support the first NPCA mode of operation and the second indication indicating that the second STA does not support the first NPCA mode of operation.

20. The method of any of claims 16-19, wherein a basic service set (BSS) ofthe AP comprises the first STA and the second STA only.

21. A method comprising:transmitting, by a first station (STA) to an access point (AP) and via a primary channel (PCH), an association request frame comprising an indication of whether the first STA supports a non-primaryDocket No.: 24-3067PCTchannel access (NPCA) mode of operation, wherein, in the NPCA mode of operation, the first STA switches from the PCH to an NPCA PCH based on detecting a first inter-basic service set (BSS) physical layer protocol data unit (PPDU) on the PCH;receiving, by the first STA from the AP, an association response frame indicating that the AP supports the NPCA mode of operation, wherein in the NPCA mode of operation, the AP switches from the PCH to the NPCA PCH based on detecting a second inter-BSS PPDU on the PCH;determining, by the STA, that a PPDU being received via the PCH comprises a third inter-BSS PPDU; andswitching, by the STA, from the PCH to the NPCA PCH based on the indication and the determining.

22. A method comprising:transmitting, by a first station (STA) to an access point (AP), a first frame comprising a first indication of whether the first STA supports a first non-primary channel access (NPCA) mode of operation; and switching, by the STA, from a primary channel (PCH) to a non-primary channel access (NPCA) PCH based on the first indication.

23. The method of claim 22, wherein the first STA is associated with the AP.

24. The method of any of claims 22-23, wherein the first STA supporting the first NPCA mode of operation comprises the first STA being capable of operating according to the first NPCA mode of operation.

25. The method of any of claims 22-24, wherein the first STA supporting the first NPCA mode of operation comprises the first STA enabling the first NPCA mode of operation.

26. The method of any of claims 22-25, wherein in the first NPCA mode of operation, the first STA switches from the PCH to the NPCA PCH based on detecting a first inter-basic service set (BSS) physical layer protocol data unit (PPDU) on the PCH.

27. The method of any of claims 22-26, wherein the first frame comprises an association request frame, a reassociation request frame, or a probe request frame.

28. The method of any of claims 22-27, wherein the first frame comprises a first field set to 1 to indicate that the first STA supports the first NPCA mode of operation.

29. The method of claim 28, wherein the first frame comprises an ultra-high reliability (UHR) Capabilities element, and wherein the UHR Capabilities element comprises the first field.

30. The method of claim 29, wherein the UHR Capabilities element comprises a UHR medium access control (MAC) Capabilities Information field, and wherein the UHR MAC Capabilities Information field comprises the first field.31 . The method of any of claims 28-30, wherein the first field comprises an “NPCA Supported” field.

32. The method of any of claims 22-31 , further comprising determining, by the first STA, that a PPDU being received via the PCH comprises a second inter-BSS PPDU.Docket No.: 24-3067PCT33. The method of claim 32, wherein the first indication indicates that the first STA supports the first NPCA mode of operation, and wherein the switching from the PCH to the NPCA PCH based on the first indication comprises switching from the PCH to the NPCA PCH based on the determining.

34. The method of claim 32, wherein the first indication indicates that the first STA does not support the first NPCA mode of operation, and wherein the switching from the PCH to the NPCA PCH based on the first indication comprises not switching from the PCH to the NPCA PCH based on the determining.

35. The method of any of claims 22-34, further comprising receiving, by the first STA from the AP, a second frame comprising a second indication of whether the AP supports a second NPCA mode of operation.

36. The method of claim 35, wherein, when the AP supports the second NPCA mode of operation, the AP switches from the PCH to the NPCA PCH based on detecting a third inter-BSS PPDU on the PCH.

37. The method of any of claims 35-36, wherein the switching from the PCH to the NPCA PCH based on the first indication comprises switching from the PCH to the NPCA PCH based on the first indication and the second indication.

38. The method of claim 37, wherein the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises switching from the PCH to the NPCA PCH based on the first indication indicating that the first STA supports the first NPCA mode of operation and the second indication indicating that the AP supports the second NPCA mode of operation.

39. The method of claim 37, wherein the switching from the PCH to the NPCA PCH based on the first indication and the second indication comprises not switching from the PCH to the NPCA PCH based on the first indication indicating that the first STA does not support the first NPCA mode of operation or the second indication indicating that the AP does not support the second NPCA mode of operation.

40. 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 1-39.

41. 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-

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