Non-primary channel access (NPCA) switching operation

Abstract

A first station (STA) transmits to an access point (AP) a tunneled direct link setup (TDLS) setup request frame comprising: a destination address indicating a second STA; and a first field indicating that the first STA supports NPCA operation. The first STA receives from the AP a TDLS setup response frame comprising: a source address indicating the second STA; a second field indicating that the second STA does not support NPCA operation; and a status code field set to a value indicating successful establishment of a TDLS link between the first STA and the second STA. Based on the second field indicating that the second STA does not support NPCA operation, the first STA transmits to the AP a frame indicating that the first STA disables NPCA operation.

Description

Docket No.: 25-3002PCTTITLE NON-PRIMARY CHANNEL ACCESS (NPCA) SWITCHING OPERATIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 749,760, filed January 27, 2025, and U.S. Provisional Application No. 63 / 754,710, filed February 6, 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)ZCIear-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 tunneled direct link setup (TDLS) operation according to the IEEE 802.11 standard.

[0016] FIG. 14 illustrates a problem that may arise when NPCA operation is used by TDLS peer STAs.

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

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

[0019] FIG. 17 shows an example of a further procedure according to an embodiment.

[0020] FIG. 18 shows an example of a further procedure 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.

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

[0024] FIG. 22 illustrates an example process according to an embodiment.Docket No.: 25-3002PCT

[0025] FIG. 23 illustrates an example process according to an embodiment.

[0026] FIG. 24 illustrates an example process according to an embodiment.

[0027] FIG. 25 illustrates an example process according to an embodiment.

[0028] FIG. 26 illustrates an example process according to an embodiment.DETAILED DESCRIPTION

[0029] 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.

[0030] 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.

[0031] 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”.Docket No.: 25-3002PCTThe 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.

[0032] If A and B are sets and every element of A is an element of B, A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B = {STA1 , STA2} are: {STA1}, {STA2}, and {STA1 , STA2}. The phrase “based on” (or equally “based at least on”) is indicative that the phrase following the term “based on" is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “in response to” (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “depending on" (or equally “depending at least to”) is indicative that the phrase following the phrase “depending on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments The phrase “employing / using” (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.

[0033] 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.

[0034] In this disclosure, parameters (or equally called, fields, or Information elements: IBs) 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.

[0035] 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 havingDocket No.: 25-3002PCTthree 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.

[0036] Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g., hardware with a biological element) or a combination thereof, which may be behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab or the like) or a modeling / simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. It may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and / or quantum hardware. Examples of programmable hardware comprise: computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages such as assembly, C, C++, or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardware description language (VHDL) or Verilog that configure connections between internal hardware modules with lesser functionality on a programmable device. The mentioned technologies are often used in combination to achieve the result of a functional module.

[0037] FIG. 1 illustrates example wireless communication networks in which embodiments of the present disclosure may be implemented.

[0038] 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.

[0039] 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.

[0040] 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).

[0041] 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.Docket No.: 25-3002PCT

[0042] 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).

[0043] For example, in FIG. 1, STAs 106-4, 106-5, and 106-6 may be configured to form a first IBSS 112-1. Similarly, STAs 106-7 and 106-8 may be configured to form a second IBSS 112-2. Since an IBSS does not include an AP, it does not include a centralized management entity. Rather, STAs within an IBSS are managed in a distributed manner. STAs forming an IBSS may be fixed or mobile.

[0044] 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.

[0045] 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.

[0046] 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 forDocket No.: 25-3002PCTall STAs where management frames are sent by the AP to ensure that all STAs (regardless of channel bonding support) can receive.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] As shown in FIG. 3, a MAC frame includes a MAC header, a variable length frame body, and a frame check sequence (FCS).

[0053] 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.Docket No.: 25-3002PCT

[0054] 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.

[0055] 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.

[0056] The type and subtype subfields together identify the function of the MAC frame. There are three frame types: control, data, and management. Each of the frame types has several defined subtypes. Bits within the subtype subfield are used to indicate a specific modification of the basic data frame (subtype 0). For example, in data frames, the most significant bit (MSB) of the subtype subfield, bit 7 (B7) of the frame control field, is defined as the QoS subfield. When the QoS subfield is set to 1 , it indicates a QoS data frame, which is a data frame that contains a QoS control field in its MAC header. The second MSB of the subtype field, bit 6 (B6) of the frame control field, when set to 1 in data subtypes, indicates a data frame that contain no frame body field.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] The power management subfield is used to indicate the power management mode of a STA.

[0061] 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.

[0062] The protected frame subfield is set to 1 if the frame body field contains information that has been processed by a cryptographic encapsulation algorithm.

[0063] The +HTC subfield indicates that the MAC frame contains an HT control field.

[0064] 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 framesDocket No.: 25-3002PCTsent 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.

[0065] Up to four address fields may be present in the MAC frame format. The address fields are used to indicate the basic service set identifier (BSSID), source address (SA), destination address (DA), transmitting address (TA), and receiving address (RA). Certain frames may not contain some of the address fields. Certain address field usage may be specified by the relative position of the address field (1-4) within the MAC header, independent of the type of address present in that field. Specifically, the address 1 field always identifies the intended receiver(s) of the frame, and the address 2 field, where present, always identifies the transmitter of the frame.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.Docket No.: 25-3002PCT

[0072] 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.

[0073] 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.

[0074] The Duration field indicates various contents depending on frame type and subtype and the QoS capabilities of the sending STA. For example, in control frames of the power save poll (PS-Poll) subtype, the Duration field carries an association identifier (AID) of the STA that transmitted the frame in the 14 least significant bits (LSB), and the 2 most significant bits (MSB) are both set to 1. In other frames sent by STAs, the Duration field contains a duration value (in microseconds) which is used by a recipient to update a network allocation vector (NAV).

[0075] 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.

[0076] 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.

[0077] 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.

[0078] The Padding field is optionally present in trigger frame 400 to extend the frame length to give recipient STAs enough time to prepare a response for transmission one SIFS (short interframe spacing) after the frame is received. The Padding field, if present, is at least two octets in length and is set to all 1s.

[0079] 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.

[0080] 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 aDocket No.: 25-3002PCTdownlink (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.

[0081] 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.

[0082] 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”).

[0083] 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.Docket No.: 25-3002PCT

[0084] 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 SIRS (Short Interframe Spacing) periods.

[0085] In an example, STA 704 may respond to RTS frame 706 by transmitting a CTS frame 708 to STA 702. CTS frame 708 may be transmitted one SIFS period after RTS frame 706. STA 704 may respond to RTS frame 706 when RTS frame 706 is addressed to STA 704 and after considering the NAV, unless the NAV was set by a frame originating from STA 702. STA 704 may respond to the RTS frame 706 when RTS frame 706 is addressed to STA 704 and if the NAV indicates idle. For a non-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.

[0086] 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.

[0087] 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

[0088] 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.

[0089] 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).Docket No.: 25-3002PCT

[0090] 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.

[0091] 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.

[0092] 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 SIPS periods.

[0093] The one or more user info fields correspond respectively to the one or more STAs solicited by the MU-RTS trigger frame. In example 800, MU-RTS trigger frame 808 may comprise a user info field for each of STAs 804 and 806 indicating that a CTS frame is solicited from each of STAs 804 and 806. As shown in FIG. 8, a user info field may comprise an AID12 subfield, an RU allocation subfield, reserved bits, and a PS 160 subfield. The AID12 subfield comprises an association identifier of the STA to which the user info field is addressed. The RU allocation subfield indicates a channel on which the solicited STA is to transmit the CTS frame. In an example, this may include a primary 20 MHz channel, a primary 40 MHz, a primary 80 MHz channel, a primary 160 MHz, an 80+80 Mhz channel, or a 320 MHz channel.

[0094] 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.

[0095] 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-APDocket No.: 25-3002PCTSTA 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.

[0096] 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 transmission of CTS frames 810 and 812, respectively, at the SIPS time boundary after an end of a received PPDU comprising MU-RTS trigger frame 808. In an example, STA 804 (or STA 806) responds to MU-RTS trigger frame 808 with a CTS frame when the following conditions are met: MU-RTS trigger frame 808 comprises a user info field addressed to the STA (the AID12 subfield of the user info field is equal to the 12 LSBs of the AID of the STA) and MU-RTS trigger frame 808 is sent by an AP with which the STA is associated; and the UL MU CS condition indicates that the medium is idle as described in section 26.5.2.5 (UL MU CS mechanism) of the IEEE 802.11 standard ("IEEE P802.11-REVme™ / D3.0, April 2023”). Otherwise, if one of the conditions is not met, STA 804 (or STA 806) does not send a CTS frame to AP 802.

[0097] In an example, STAs 804 and 806 may set an RA field of respectively CTS frames 810 and 812 to a TA obtained from the TA field of MU-RTS trigger frame 808. In an example, STAs 804 and 806 may set a duration field of respectively CTS frames 810 and 812 based on the duration field of MU-RTS trigger frame 808, namely as equal to the value of the duration field of MU-RTS trigger frame 808, adjusted by subtracting the time required to transmit respectively CTS frames 810 and 812 and one SIPS period.

[0098] OBSS STAs exposed to AP 802 may receive MU-RTS trigger frame 808 due to being within the communication range of AP802. 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.

[0099] 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.

[0100] 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.Docket No.: 25-3002PCT

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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).

[0105] 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 communicateDocket No.: 25-3002PCTvia 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.

[0106] 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”).

[0107] 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.

[0108] 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 support 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.

[0109] An NPCAAP 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 fieldDocket No.: 25-3002PCTof 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.

[0110] 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 an NPCA 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.

[0111] 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.

[0112] 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.Docket No.: 25-3002PCTc. 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.c. 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.

[0113] 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 timec) 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.Docket No.: 25-3002PCTd) 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 channelii.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.

[0114] 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 NPCADocket No.: 25-3002PCToperation 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).

[0115] 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.

[0116] 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, a transmission 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).

[0117] 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

[0118] 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.

[0119] 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 mayDocket No.: 25-3002PCTbelong 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

[0120] 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 support field. In an example, STA 1204 may set the NPCA support field 1 to indicate the support of NPCA operation by STA 1204.

[0121] AP 1202 may respond to frame 1206 by transmitting a frame 1208 to STA 1204. Frame 1208 may indicate support of NPCA operation by AP 1202. Frame 1208 may comprise an Association Response frame, a Reassociation Response frame, a Probe Response frame, or a beacon frame, for example. In an implementation, frame 1208 comprises a UHR Capabilities element. The UHR Capabilities element may comprise a UHR MAC Capabilities Information field. The UHR MAC Capabilities Information field may comprise an NPCA support field. In an example, AP 1202 may set the NPCA support field to 1 to indicate the support of NPCA operation by AP 1202.

[0122] 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.

[0123] 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.Docket No.: 25-3002PCTSimilarly, 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.

[0124] FIG. 13 shows an example 1300 that illustrates tunneled direct link setup (TDLS) operation according to the IEEE 802.11 standard. TDLS operation allows two STAs, of the same BSS, to establish a direct peer-to-peer (PTP) link for improved performance and reduced latency. As shown in FIG. 13, example 1300 includes an AP 1302 and STAs 1304 and 1306. STAs 1304 and 1306 may be associated with AP 1302 and may belong to the same BSS. AP 1302 and STAs 1304 and 1306 may operate on a primary channel (PCH). It is assumed in example 1300 that STAs 1304 and 1306 support TDLS operation.

[0125] TDLS operation may include a discovery phase and a setup phase. In the discovery phase, a first STA discovers whether a second STA, in the same BSS, supports TDLS. For example, in example 1300, STA 1304 uses the discovery phase to determine whether STA 1306 supports TDLS To initiate the discovery phase, STA 1304 transmits a frame 1308 to AP 1302 via the PCH. Frame 1308 may be a data frame. Frame 1308 encapsulates a TDLS discovery request frame 1310 for STA 1306. STA 1304 may set a receiver address (RA) of frame 1308 to an address (e.g., MAC address) of AP 1302 or the BSSID of the BSS of which STA 1304 is a member. STA 1304 may set a destination address (DA) of TDLS discovery request frame 1310 to an address (e.g., MAC address) of STA 1306. A payload of TDLS discovery request frame 1310 comprises a TDLS discovery request action field. The TDLS discovery request action field comprises a Link Identifier element. STA 1304 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1304 is a member. STA 1304 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1304. STA 1304 may set a TDLS responder STA Address of the Link Identifier element to the DA ofTDLS discovery request frame 1310, i.e., an address (e.g., MAC address) of STA 1306.

[0126] On receiving frame 1308, AP 1302 determines, based on the destination address of TDLS discovery request frame 1310, that TDLS discovery request frame 1310, encapsulated in frame 1308, is intended for STA 1306. AP 1302 extracts TDLS discovery request frame 1310 from frame 1308 and encapsulates TDLS discovery request frame 1310 in a frame 1312, which AP 1302 transmits to STA 1306 via the PCH. Frame 1312 may be a data frame. AP 1302 sets an RA of frame 1312 to an address (e.g., MAC address) of STA 1306.

[0127] On receiving frame 1312, STA 1306 determines that the BSSID indicated in (the BSSID field of the Link Identifier element of) TDLS discovery request frame 1310, encapsulated in frame 1312, matches the BSSID of the BSS of which STA 1306 is a member and that TDLS discovery request frame 1310 is sent by STA 1304. Accordingly, STA 1306 responds to TDLS discovery request frame 1310 by transmitting (directly) to STA 1304 a TDLS discovery response frame 1314. TDLS discovery response frame 1314 comprises a TDLS discovery response frame action field. The TDLS discovery response frame action field comprises aDocket No.: 25-3002PCTLink Identifier element. STA 1306 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1306 is a member. STA 1306 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1304. STA 1306 may set a TDLS responder STA address of the Link Identifier element to an address (e.g., MAC address) of STA 1306. The TDLS discovery response frame action field further comprises a Capability field that indicates the capabilities of STA 1306 and a Supported Channels element that indicates a list of channel subbands in which STA 1306 is capable of operating. The TDLS discovery response frame action field may further comprise an Extended Capabilities element if any of the fields in this element are nonzero. The Extended Capabilities element may include a TDLS Support subfield set to 1 to indicate support for TDLS by STA 1306. The Extended Capabilities element may include a TDLS Channel Switching subfield set to 1 when TDLS channel switching is enabled by STA 1306.

[0128] After receiving TDLS discovery response frame 1314 from STA 1306, STA 1304 may establish a TDLS direct link with STA 1306. To do so, STA 1304 transmits a frame 1316 to AP 1302 via the PCH. Frame 1316 may be a data frame. Frame 1316 encapsulates a TDLS setup request frame 1318 for STA 1306. STA 1304 may set an RA of frame 1316 to an address (e.g., MAC address) of AP 1302 or the BSSID of the BSS of which STA 1304 is a member. STA 1304 may set a DA of TDLS setup request frame 1318 to an address (e.g., MAC address) of STA 1306. A payload of TDLS setup request frame 1318 comprises a TDLS setup request action field. The TDLS setup request action field comprises a Link Identifier element. STA 1304 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1304 is a member. STA 1304 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1304. STA 1304 may set a TDLS responder STA Address of the Link Identifier element to the DA of TDLS setup request frame 1318, i.e., an address (e.g., MAC address) of STA 1306. The TDLS setup request action field further comprises a Capability field that indicates the capabilities of STA 1304 and a Supported Channels element that indicates a list of channel subbands in which STA 1304 is capable of operating. The TDLS setup request action field may further comprise an Extended Capabilities element if any of the fields in this element are nonzero. The Extended Capabilities element may include a TDLS Support subfield set to 1 to indicate support for TDLS by STA 1306. The Extended Capabilities element may include a TDLS Channel Switching subfield set to 1 when TDLS channel switching is enabled by STA 1304.

[0129] On receiving frame 1316, AP 1302 determines, based on the destination address of TDLS setup request frame 1318, that TDLS setup request frame 1318, encapsulated in frame 1316, is intended for STA 1306. AP 1302 extracts TDLS setup request frame 1318 from frame 1316 and encapsulates TDLS setup request frame 1318 in a frame 1320, which AP 1302 transmits to STA 1306 via the PCH. Frame 1320 may be a data frame. AP 1302 sets an RA of frame 1320 to an address (e.g., MAC address) of STA 1306.

[0130] On receiving frame 1320, STA 1306 determines that the BSSID indicated in (the BSSID field of the Link Identifier element of) TDLS setup request frame 1318, encapsulated in frame 1320, matches the BSSIDDocket No.: 25-3002PCTof the BSS of which STA 1306 is a member. Accordingly, STA 1306 may accept TDLS setup request frame 1318 by transmitting to STA 1304, via AP 1302, a TDLS setup response frame 1324 with a status code SUCCESS. Alternatively, STA 1306 may decline TDLS setup request frame 1318 by transmitting to STA 1304, via AP 1302, a TDLS setup response frame 1324 with a status code REQUEST_DECLINED. It is noted that STA 1306 declines a TDLS setup request frame when the BSSID indicated in (the BSSID field of the Link Identifier element of) TDLS setup request frame 1318 does not match the BSSID of the BSS of which STA 1306 is a member.

[0131] In the event that STA 1306 receives TDLS setup request frame 1318 after having sent a TDLS setup request frame and before receiving the corresponding TDLS setup response frame, STA 1306 compares the source address of TDLS setup request frame 1318 to its own MAC address to determine whether to respond to TDLS setup request frame 1318. Specifically, if the source address of TDLS setup request frame 1318 (e.g., MAC address of STA 1304) is higher than the MAC address of STA 1306, STA 1306 discards TDLS setup request frame 1318 without sending a response to TDLS setup request frame 1318. If the source address of TDLS setup request frame 1318 (e.g., MAC address of STA 1304) is lower than the MAC address of STA 1306, STA 1306 responds to TDLS setup request frame 1318 by transmitting to STA 1304, via AP 1302, TDLS setup response frame 1324 as described above (accepting or declining TDLS setup request frame 1318).

[0132] As shown, STA 1306 encapsulates TDLS setup response frame 1324 in a frame 1322 that STA 1306 transmits to AP 1302. Frame 1322 may be a data frame. STA 1306 may set an RA of frame 1322 to an address (e.g., MAC address) of AP 1302 or the BSSID of the BSS of which STA 1306 is a member. STA 1306 may set a DA of TDLS setup response frame 1324 to an address (e.g., MAC address) of STA 1304. A payload of TDLS setup response frame 1324 comprises a TDLS Setup Response action field. The TDLS Setup Response action field comprises a Link Identifier element. STA 1306 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1306 is a member. STA 1306 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1304. STA 1306 may set a TDLS responder STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1306. The TDLS Setup Response action field further comprises a Capability field that indicates the capabilities of STA 1306 and a Supported Channels element that indicates a list of channel subbands in which STA 1306 is capable of operating. The TDLS Setup Response action field may further comprise an Extended Capabilities element if any of the fields in this element are nonzero. The Extended Capabilities element may include a TDLS Support subfield set to 1 to indicate support for TDLS by STA 1306. The Extended Capabilities element may include a TDLS Channel Switching subfield set to 1 when TDLS channel switching is enabled by STA 1306.

[0133] On receiving frame 1322, AP 1302 determines, based on the destination address of TDLS setup response frame 1324, that TDLS setup response frame 1324, encapsulated in frame 1322, is intended forDocket No.: 25-3002PCTSTA 1304. AP 1302 extracts TDLS setup response frame 1324 from frame 1322 and encapsulates TDLS setup response frame 1324 in a frame 1326, which AP 1302 transmits to STA 1304 via the PCH. Frame 1326 may be a data frame. AP 1302 sets an RA of frame 1326 to an address (e.g., MAC address) of STA 1304.

[0134] If STA 1304 receives TDLS setup response frame 1324 comprising a status code not equal to SUCCESS, or if STA 1304 does not receive TDLS setup response frame 1324 within a timeout period (dot1 ITDLSResponseTimeout), STA 1304 terminates the TDLS setup procedure and discards TDLS setup response frame 1324. STA 1304 may resume transmitting MSDUs to STA 1306 through AP 1302. Alternatively (as illustrated in example 1300), STA 1304 sends a TDLS setup confirm frame 1330 to STA 1306, via AP 1302, to confirm the receipt of TDLS setup response frame 1324. As shown, STA 1304 encapsulates TDLS setup confirm frame 1330 in a frame 1328 that STA 1304 transmits to AP 1302. Frame 1328 may be a data frame. STA 1304 may set an RA of frame 1328 to an address (e.g., MAC address) of AP 1302 or the BSSID of the BSS of which STA 1304 is a member. STA 1304 may set a DA of TDLS setup confirm frame 1330 to an address (e.g., MAC address) of STA 1306. A payload of TDLS setup confirm frame 1330 comprises a TDLS setup confirm action field. The TDLS setup confirm action field comprises a Link Identifier element. STA 1304 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1304 is a member. STA 1304 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1304. STA 1304 may set a TDLS responder STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1306.

[0135] The TDLS setup confirm action field of TDLS setup confirm frame 1330 may further comprise a status code. If the status code of the TDLS setup confirm action field of TDLS setup confirm frame 1330 is other than SUCCESS, STA 1304 may resume transmitting MSDUs to STA 1306 through AP 1302. If the status code of the TDLS setup confirm action field of TDLS setup confirm frame 1330 is other than SUCCESS, STA 1306 may resume transmitting MSDUs to STA 1304 through AP 1302. STA 1304 shall not transmit MSDUs over the direct link to STA 1306 before transmitting TDLS setup confirm frame 1330 with status code SUCCESS. Similarly, STA 1306 shall not transmit MSDUs over the direct link to STA 1304 before receiving TDLS setup confirm frame 1330 with status code SUCCESS.

[0136] In example 1300, it is assumed that STA 1304 transmits TDLS setup confirm frame 1330 with status code SUCCESS to STA 1306. This establishes a TDLS direct link between STA 1304 and STA 1306 and STAs 1304 and 1306 become TDLS peer STAs. STA 1304 shall accept data frames received from STA 1306 directly and may transmit data frames destined to STA 1306 over the TDLS direct link. Similarly, STA 1306 shall accept data frames received from STA 1304 directly and may transmit data frames destined to STA 1304 over the TDLS direct link. For example, STA 1304 transmits a data frame 1334 to STA 1306 via the TDLS direct link and STA 1306 accepts data frame 1334 received via the TDLS direct link. Similarly, STA 1306 transmits a data frame 1336 to STA 1304 via the TDLS direct link and STA 1304 accepts data frame 1336 received via the TDLS direct link.Docket No.: 25-3002PCT

[0137] To tear down the TDLS direct link, STA 1304 (or STA 1306) sends a TDLS Teardown frame to STA 1306 (or STA 1304). STA 1304 (or STA 1306) sends the TDLS Teardown frame over the TDLS direct link when STA 1306 (or STA 1304) with a reason code set to TDLS_TEARDOWN_UNSPECIFIED_REASON, except when STA 1304 (or STA 1306) is unreachable via the TDLS direct link, in which case STA 1304 (or STA 1306) sends the TDLS Teardown frame through AP 1302 with a reason code set to TDLS_TEARDOWN_PEER_UNREACHABLE. If the TDLS direct link is on an off-channel (further described below) when this condition occurs, then STA 1304 (or STA 1306) may switch back to a base channel (e.g., PCH) without initiating a channel switch frame exchange, before transmitting the TDLS Teardown frame. The base channel is the primary channel on which AP 1302 operates. The off-channel is a channel other than the base channel to which the TDLS direct link is switched.

[0138] An established TDLS direct link may be switched from the base channel to an off-channel, and vice versa. A STA that supports / enables TDLS channel switching sets a dot1 ITDLSChannelSwitchingActivated equal to true and shall set dot11 M u ItiDomainCapabil ItyActivated and dot11 ExtendedChannelSwitchActivated to true. When TDLS channel switching is enabled, the STA sets a TDLS Channel Switching subfield (in an Extended Capabilities field, e.g., in a TDLS setup request frame or TDLS setup response frame) to 1. The STA includes a Supported Channels element and a Supported Operating Classes element in all TDLS setup request and TDLS setup response frames that include a TDLS Channel Switching subfield equal to 1. The Supported Channels element indicates the channels supported for the current operating class. The STA includes in the Supported Channels element only channels for which the STA is capable of adhering to the local power constraint. A channel switch shall not be initiated by a STA when the TDLS peer STA did not set the TDLS Channel Switching capability subfield to 1 in the transmitted TDLS setup request frame or the TDLS setup response frame that caused the TDLS direct link to be set up.

[0139] Referring again to FIG. 13, if STAs 1304 and 1306 support TDLS channel switching, either of STA 1304 or STA 1306 may initiate TDLS channel switching. For example, while STAs 1304 and 1306 operate on an initial channel, STA 1304 may transmit a TDLS Channel Switch Request frame to STA 1306 via the TDLS direct link, indicating a requested switch to a target channel. The target channel is specified by STA 1304 from the set of operating classes supported by both STAs 1304 and 1306. The target channel and operating class are specified in the TDLS Channel Switch Request frame. STA 1306 transmits an Ack frame after a SIFS from receiving the TDLS Channel Switch Request frame. After processing the TDLS Channel Switch Request frame, STA 1306 transmits a TDLS Channel Switch Response frame to STA 1304. STA 1304 responds with an Ack frame after a SIFS from receiving the TDLS Channel Switch Response frame. If the TDLS Channel Switch Response frame comprises a status code equal to REQUEST_DECLINED, STAs 1304 and 1306 continue to operate on the initial / current channel. If the TDLS Channel Switch Response frame comprises a status code equal to SUCCESS, STAs 1304 and 1306 begin listening on the targetDocket No.: 25-3002PCTchannel no later than a duration (SwitchTime) after the end of the PPDU containing the Ack frame transmitted by STA 1304, as measured on the wireless medium.

[0140] After switching to the target channel, each of STAs 1304 and 1306 performs a clear channel assessment (CCA) on the target channel, until a frame is detected by which STA 1304 or STA 1306 sets its NAV, or until a period of time equal to a synchronization duration (dot1 ITDLSNavSync) has elapsed. If STA 1304 or STA 1306 set its NAV based on a detected frame, STA 1304 or STA 1306 may contend for the wireless medium (after a random backoff) when its NAV reaches zero to transmit a first transmission on the target channel. If STA 1304 or STA 1304 does not detect a frame on the target channel before dot1 ITDLSNavSync expires, STA 1304 or STA 1306 may contend for the wireless medium (after a random backoff) after dot1 ITDLSNAVSync expires to transmit the first transmission on the target channel. The first transmission on the target channel shall not start before the end of the duration SwitchTime. The initiator of the channel switch shall transmit a data frame on the target channel, unless a timeout duration (SwitchTimeout) has expired or the responder to the channel switch transmitted a data frame on the target channel.

[0141] In the case of a switch of the TDLS direct link to an off-channel, if no successful frame exchange sequence occurs on the off-channel within a timeout duration (SwitchTimeout) after the end of the PPDU[+SigExt] containing the Ack frame transmitted by STA 1304, as measured on the WM, STA 1304 or STA 1306 returns to the base channel. STA 1304 or STA 1306 shall be listening on the base channel not later than a duration (SwitchTime) after the end of the timeout duration (SwitchTimeout). After changing channels (either from the base channel to the off-channel or from the off-channel to the base channel), a TDLS peer STA shall perform CCA until a frame is detected by which the TDLS peer STA can set its NAV, or until a period of time equal to a synchronization duration (dot1 ITDLSNavSync) has elapsed.

[0142] Both the TDLS Channel Switch Request frame and the TDLS Channel Switch Response frame may contain a Channel Switch Timing element. The Channel Switch Timing element may comprise a SwitchTime value and a SwitchTimeout value. The SwitchTime and SwitchTimeout values comprised in a TDLS Channel Switch Timing element included in a TDLS Channel Switch Request frame may specify values required at the STA sending the TDLS Channel Switch Request frame. The SwitchTime and SwitchTimeout values specified in a TDLS Channel Switch Timing element included in a TDLS Channel Switch Response frame shall meet the requirements at the STA sending the TDLS Channel Switch Response frame and shall be equal to or larger than the values specified in the corresponding TDLS Channel Switch Request frame. The timing parameters specified in the Channel Switch Timing element included in the TDLS Channel Switch Response frame shall be used for the TDLS channel switching procedure. This procedure causes the larger of the two switch times to become the value that is transmitted in the TDLS Channel Switch Response frame.

[0143] A TDLS peer STA shall be in a power save (PS) mode with the AP and shall not be involved in an active Service Period with the AP before sending a TDLS Channel Switch Request frame or a TDLS ChannelDocket No.: 25-3002PCTSwitch Response frame with the Status Code field set to SUCCESS. The TDLS peer STA that receives a TDLS Channel Switch Request frame may enter PS mode with the AP prior to sending the TDLS Channel Switch Response frame.

[0144] A TDLS peer STA may switch the TDLS direct link from an off-channel to the base channel by sending a TDLS Channel Switch Response frame indicating the base channel as the target channel, without a prior TDLS Channel Switch Request frame. The TDLS Channel Switch Timing element comprised in the TDLS Channel Switch Response frame shall be the same as contained in the Channel Switch Response frame that caused the switch to the off-channel.

[0145] FIG. 14 shows an example 1400 that illustrates a problem that may arise when NPCA operation is used by TDLS peer ST As. As shown in FIG. 14, example 1400 includes STAs 1304 and STA 1306 described above. Example 1400 further includes AP 1302 (not shown in FIG. 14). In example 1400, it is assumed that a TDLS direct link has been established between STAs 1304 and 1306, as described in example 1300, on the primary channel (PCH) of AP 1302 and that STAs 1304 and 1306 exchange data frames (e.g., including data frames 1334 and 1336) via the TDLS direct link. STAs 1304 and 1306 are thus considered TDLS peer STAs. It is further assumed in example 1400 that STA 1304 supports NCPA operation. That is, STA 1304 may support operation over a plurality of channels, including the PCH and an NPCA PCH, and may be configured to switch from the PCH to the NPCA PCH based on detecting / receiving, on the PCH, of an inter-BSS PPDU. STA 1304 may be configured to 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 to switch to the NPCA PCH for a duration based on the NAV set for the PCH.

[0146] In example 1400, an inter-BSS PPDU 1402 is transmitted on the PCH. STA 1304 detects inter-BSS PPDU 1402 and, based on supporting NPCA operation, switches from the PCH to the NPCA PCH based on inter-BSS PPDU 1402, after a setting a NAV based on inter-BSS PPDU 1402. In contrast, in an example, based on not supporting NPCA operation or having disabled NPCA operation, STA 1306 does not switch from the PCH to the NPCA PCH based on inter-BSS PPDU 1402. STAs 1304 and 1306 may thus be precluded from communicating directly, via the TDLS direct link or via the NPCA PCH, while STA 1304 operates on the NPCA PCH. In another example (as shown in FIG. 14), STA 1306 does not detect inter-BSS PPDU 1402 on the PCH and, without information that STA 1304 switched to the NPCA PCH, attempts to transmit a data frame 1404 via the TDLS direct link on the PCH However, as STA 1304 switched to the NPCA PCH, STA 1304 does not receive data frame 1404. STA 1306 may attempt re-transmission of data frame 1404 to STA 1304 on the PCH, without success, until STA 1304 return to the PCH. In an example, where data frame 1404 contains low latency data, the low latency data may be lost. Accordingly, communication between peer TDLS STAs 1304 and 1306 may potentially be degraded when at least one of STAs 1304 and 1306 supports / enables NPCA operation.Docket No.: 25-3002PCT

[0147] 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 TDLS frame comprising a first field indicating whether the first STA supports NPCA operation. The first STA may comprise a TDLS initiator STA. The first TDLS frame may further comprise a first indication of a second STA. The second STA may comprise a TDLS responder STA. The first TDLS frame may comprise a TDLS discovery request frame, a TDLS setup request frame, or a TDLS setup confirm frame. In an embodiment, the first TDLS frame comprises a first capabilities element (e.g., UHR capabilities element) comprising the first field. In an embodiment, the first TDLS frame comprises a TDLS action field that comprises the first capabilities element. In an embodiment, where the first frame is a TDLS setup request frame, the TDLS Action field comprises a TDLS setup request action field. In an embodiment, wherein the first frame is a TDLS setup confirm frame, the TDLS action field comprises a TDLS setup confirm action field. In an embodiment, the first STA determines whether to switch (or switches) from a PCH to an NPCA PCH based on the first field. In an embodiment, where the first field indicates that the first STA supports NPCA operation, the first STA switches from the PCH to the NPCA PCH based on determining that a PPDU being received via the PCH comprises an inter-BSS PPDU. The first AP transmits the first TDLS frame comprising the first field to the second STA. As such, the second STA is able to determine whether the first STA supports NPCA operation and whether the first STA switches from the PCH to the NPCA PCH based on detecting an inter-BSS PPDU on the PCH. If both the first STA and the second STA support NPCA operation, the first STA and the second STA may continue communicating over the NPCA PCH after switching from the PCH to the NPCA PCH based on detecting an inter-BSS PPDU.

[0148] In another aspect, the first STA receives from the AP a second TDLS frame comprising a second field indicating whether the second STA supports NPCA operation. The second TDLS frame may further comprise a second indication of the second STA. The second TDLS frame may comprise a TDLS discovery response frame or a TDLS setup response frame. In an embodiment, the second TDLS frame comprises a second capabilities element (e.g., UHR capabilities element) comprising the second field. In an embodiment, the second TDLS frame comprises a TDLS Action field that comprises the second capabilities element. In an embodiment, where the second frame is a TDLS setup response frame, the TDLS Action field comprises a TDLS Setup Response Action field. In another embodiment, the first STA determines whether to switch (or switches) from the PCH to the NPCA PCH based on the first field and the second field. In an embodiment, where the first field indicates that the first STA supports NPCA operation and the second field indicates that the second STA supports NPCA operation, the first STA switches from the PCH to the NPCA PCH based on determining that a PPDU being received via the PCH comprises an inter-BSS PPDU. In another embodiment, where the first field indicates that the first STA supports NPCA operation and the second field indicates that the second STA does not support NPCA operation, the first STA disables NPCA operation. The first STA may transmit to the AP a frame indicating that the first STA disables NPCA operation. By disabling NPCADocket No.: 25-3002PCToperation, the first STA does not switch from the PCH to the NPCA PCH based on detecting an inter-BSS PPDU on the PCH, and the possibility of the second STA attempting to communicate with the first STA on the PCH, while the first STA is operating on the NPCA PCH, is avoided.

[0149] In a further aspect, an AP receives from a first STA a first TDLS frame comprising a first field indicating whether the first STA supports NPCA operation. The first STA may comprise a TDLS initiator STA. The first TDLS frame may further comprise a first indication of a second STA. The second STA may comprise a TDLS responder STA. The first TDLS frame may comprise a TDLS discovery request frame, a TDLS setup request frame, or TDLS setup confirm frame. In an embodiment, the first TDLS frame comprises a first capabilities element (e.g., UHR capabilities element) comprising the first field. In an embodiment, the first TDLS frame comprises a TDLS action field that comprises the first capabilities element. In an embodiment, where the first frame is a TDLS setup request frame, the TDLS action field comprises a TDLS setup request action field. In an embodiment, where the first frame is a TDLS setup confirm frame, the TDLS action field comprises a TDLS setup confirm action field. The AP transmits to the first STA a second TDLS frame comprising a second field indicating whether the second STA supports NPCA operation. The second TDLS frame may further comprise a second indication of the second STA. The second TDLS frame may comprise a TDLS discovery response frame or a TDLS setup response frame. In an embodiment, the second TDLS frame comprises a second capabilities element (e.g., UHR capabilities element) comprising the second field. In an embodiment, the second TDLS frame comprises a TDLS action field that comprises the second capabilities element. In an embodiment, where the second frame is a TDLS setup response frame, the TDLS action field comprises a TDLS setup response action field. As such, the AP facilitates the exchange of NPCA support information within a TDLS frame exchange between the first STA and the second STA. The first STA and / or the second STA may determine whether to establish a TDLS direct link based on the NPCA support information and, when a TDLS direct link is established, may use the NPCA support information to enable / disable NPCA operation so as to enhance direct communication between the two STAs.

[0150] 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 includes an AP 1502 and STAs 1504 and 1506. STAs 1504 and 1506 may be associated with AP 1502 and may therefore belong to the same BSS as AP 1502. STAs 1504 and 1506 support TDLS operation as described in FIG. 13 above. Each of AP 1502, STA 1504, and STA 1506 may comprise an MLD.

[0151] Example 1500 may begin with STA 1504 transmitting a frame 1508 to AP 1502. Frame 1508 may comprise a data frame. Frame 1508 encapsulates a TDLS frame 1510 for STA 1506. In an embodiment, frame 1508 comprises a MAC frame that comprises TDLS frame 1510. STA 1504 may set a receiver address (RA) of frame 1508 to an address (e.g., MAC address) of AP 1502 or the BSSID of the BSS of which STA 1504 is a member. STA 1504 may set a destination address (DA) of TDLS frame 1510 to an address (e.g., MAC address) of STA 1506.Docket No.: 25-3002PCT

[0152] In an embodiment (not shown in FIG. 15), TDLS frame 1510 comprises a TDLS discovery request frame. A payload of the TDLS discovery request frame comprises a TDLS discovery request action field. The TDLS discovery request action field comprises a Link Identifier element. STA 1504 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1504 is a member. STA 1504 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1504. STA 1504 may set a TDLS responder STA Address of the Link Identifier element to the DA of the TDLS discovery request frame, i.e., an address (e.g., MAC address) of STA 1506. That is, STA 1504 transmits the TDLS discovery request frame to discover whether STA 1506 supports TDLS.

[0153] In another embodiment (illustrated in FIG. 15), TDLS frame 1510 comprises a TDLS setup request frame. A payload of the TDLS setup request frame comprises a TDLS setup request action field. The TDLS setup request action field comprises a Link Identifier element. STA 1504 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1504 is a member. STA 1504 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1504. STA 1504 may set a TDLS responder STA Address of the Link Identifier element to the DA of the TDLS setup request frame, i.e., an address (e.g., MAC address) of STA 1506. The TDLS setup request action field further comprises a capability field that indicates the capabilities of STA 1504 and / or a Supported Channels element that indicates a list of channel subbands in which STA 1504 is capable of operating. In an embodiment, when STA 1504 supports NPCA operation, the list of channel subbands may comprise the NPCA PCH. In another embodiment, the capability field includes a UHR capabilities element. The UHR capabilities element may include a UHR MAC capabilities information field and / or a UHR PHY capabilities information field. In an embodiment, the UHR MAC capabilities information field includes an NPCA support field that indicates whether STA 1504 supports NPCA operation. The TDLS setup request action field may further comprise an Extended Capabilities element if any of the fields in this element are nonzero. The Extended Capabilities element may include a TDLS Support subfield set to 1 to indicate support for TDLS by STA 1504. The Extended Capabilities element may include a TDLS Channel Switching subfield set to 1 when TDLS channel switching is enabled by STA 1504.

[0154] On receiving frame 1508, AP 1502 determines, based on the destination address of TDLS frame 1510, that TDLS frame 1510, encapsulated in frame 1508, is intended for STA 1506. AP 1502 extracts TDLS frame 1510 from frame 1508 and encapsulates TDLS frame 1510 in a frame 1512, which AP 1502 transmits to STA 1506 via the PCH. Frame 1512 may be a data frame. AP 1502 sets an RA of frame 1512 to an address (e.g., MAC address) of STA 1506.

[0155] In an embodiment, TDLS frame 1510 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1508 or frame 1512, comprises a first field that indicates whether STA 1504 supports NPCA operation. In an embodiment, STA 1504 supporting NPCA operation comprises STA 1504 being capable of operating according to NPCA operation. In an embodiment, STA 1504Docket No.: 25-3002PCTsupporting the NPCA operation comprises (implicitly indicates) STA 1504 enabling / activating NPCA operation. In an embodiment, according to NPCA operation, STA 1504 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, the first field is set to a first value (e.g., 1) to indicate that STA 1504 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 does not support NPCA operation. In embodiment, TDLS frame 1510 comprises a first capabilities element comprising the first field. The first capabilities element may comprise an ultra-high reliability (UHR) capabilities element. The UHR capabilities element may comprise a UHR capabilities information field comprising the first field. In an embodiment, the first field comprises an NPCA support field.

[0156] In an embodiment, TDLS frame 1510 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1508 or frame 1512, may further comprise a second field that indicates whether STA 1504 enables / activates NPCA operation. In an embodiment, the second field comprises an NPCA Operation Information Present field. In an embodiment, the second field is set to a first value (e.g., 1) to indicate that STA 1504 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 disables / deactivates NPCA operation. In embodiment, frame 1510 comprises a second capabilities (or operation) element comprising the second field. The second capabilities element may comprise a UHR capabilities (or UHR operation) element. The second capabilities element may be the same as the first capabilities element comprising the first field.

[0157] In an embodiment, TDLS frame 1510 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1508 or frame 1512, may further comprise one or more first NPCA-related parameters. The one or more first NPCA-related parameters may comprise a first NPCA switching delay, a first NPCA switching back delay, a first NPCA minimum duration threshold, and the NPCA primary channel of STA 1504.

[0158] Returning to FIG. 15, on receiving frame 1512, STA 1506 determines that the BSSID indicated in (the BSSID field of the Link Identifier element of) TDLS frame 1510, encapsulated in frame 1512, matches the BSSID of the BSS of which STA 1506 is a member and that TDLS frame 1510 is sent by STA 1504. In response to TDLS frame 1510, STA 1506 transmits a second TDLS frame, directly or via AP 1502, to STA 1504.

[0159] In an embodiment (not shown in FIG. 15), where TDLS frame 1510 comprises a TDLS discovery request frame, STA 1506 responds to the TDLS discovery request frame by transmitting, directly to STA 1504, a TDLS discovery response frame as the second TDLS frame. The TDLS discovery response frame comprises a TDLS discovery response frame action field. The TDLS discovery response frame action field comprises a Link Identifier element. STA 1506 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1506 is a member. STA 1506 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1504. STA 1506 may set a TDLS responder STA address of the Link Identifier element to an address (e.g., MAC address) of STA 1506. The TDLSDocket No.: 25-3002PCTdiscovery response frame action field further comprises a Capability field that indicates the capabilities of STA 1506 and a Supported Channels element that indicates a list of channel subbands in which STA 1506 is capable of operating In an embodiment, where STA 1506 supports NPCA operation, the list of channel subbands comprises the NPCA PCH. The TDLS discovery response frame action field may further comprise an Extended Capabilities element if any of the fields in this element are nonzero. The Extended Capabilities element may include a TDLS Support subfield set to 1 to indicate support for TDLS by STA 1506. The Extended Capabilities element may include a TDLS Channel Switching subfield set to 1 when TDLS channel switching is enabled by STA 1506.

[0160] In another embodiment (as illustrated in FIG. 15), where TDLS frame 1510 comprises a TDLS setup request frame, STA 1506 may accept the TDLS setup request frame by transmitting to STA 1504, via AP 1502, a TDLS setup response frame with a status code SUCCESS as the second TDLS frame. Alternatively, STA 1506 may decline the TDLS setup request frame by transmitting to STA 1504, via AP 1502, a TDLS setup response frame with a status code REQUEST_DECLINED. It is noted that STA 1506 declines a TDLS setup request frame when the BSSID indicated in (the BSSID field of the Link Identifier element of) the TDLS setup request frame does not match the BSSID of the BSS of which STA 1506 is a member. In an embodiment, STA 1506 accepts or declines the TDLS setup request frame based on the first field, the second field, and / or the one or more first NPCA-related parameters. For example, STA 1506 may accept the TDLS setup request frame based on the first field being set to the first value or may decline the TDLS setup request frame based on the first field being set to the second value, or vice versa. Alternatively, or additionally, STA 1506 may accept the TDLS setup request frame based on the second field being set to the first value or may decline the TDLS setup request frame based on the second field being set to the second value, or vice versa. Alternatively, or additionally, STA 1506 may accept or decline the TDLS setup request frame based on the one or more first NPCA-related parameters matching or not corresponding second NPCA-related parameters of STA 1506.

[0161] In example 1500, STA 1506 accepts the TDLS setup request frame comprised in TDLS frame 1510 and transmits to STA 1504, via AP 1502, a TDLS setup response frame 1516 with a status code SUCCESS. As shown, STA 1506 encapsulates TDLS setup response frame 1516 in a frame 1514 that STA 1506 transmits to AP 1502. Frame 1514 may be a data frame. In an embodiment, frame 1514 comprises a MAC frame that comprises TDLS setup response frame 1516. STA 1506 may set an RA of frame 1514 to an address (e.g., MAC address) of AP 1502 or the BSSID of the BSS of which STA 1506 is a member. STA 1506 may set a DA of TDLS setup response frame 1516 to an address (e.g., MAC address) of STA 1504. A payload of TDLS setup response frame 1516 comprises a TDLS Setup Response action field. The TDLS Setup Response action field comprises a Link Identifier element. STA 1506 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1506 is a member. STA 1506 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1504. STADocket No.: 25-3002PCT1506 may set a TDLS responder STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1506. The TDLS Setup Response action field further comprises a capability field that indicates the capabilities of STA 1506 and / or a Supported Channels element that indicates a list of channel subbands in which STA 1506 is capable of operating. In an embodiment, where STA 1506 supports NPCA operation, the list of channel subbands comprises the NPCA PCH. In another embodiment, the capability field includes a UHR capabilities element. The UHR capabilities element may include a UHR MAC capabilities information field and / or a UHR PHY capabilities information field. In an embodiment, the UHR MAC capabilities information field includes an NPCA support field that indicates whether STA 1506 supports NPCA operation. The TDLS Setup Response action field may further comprise an Extended Capabilities element if any of the fields in this element are nonzero. The Extended Capabilities element may include a TDLS Support subfield set to 1 to indicate support for TDLS by STA 1506. The Extended Capabilities element may include a TDLS Channel Switching subfield set to 1 when TDLS channel switching is enabled by STA 1506.

[0162] In an embodiment, the second TDLS frame transmitted by STA 1506 (directly to STA 1504 or via AP 1502) comprises a third field that indicates whether STA 1506 supports NPCA operation. As described above, STA 1506 may transmit the second TDLS frame directly to STA 1504 in response to TDLS frame 1510 comprising a TDLS discovery request frame. In this case, the second TDLS frame comprises a TDLS discovery response frame. Alternatively, where TDLS frame 1510 comprises a TDLS setup request frame, STA 1506 may transmit the second TDLS frame via AP 1502. In this case, the second TDLS frame comprises TDLS setup response frame 1516 and is encapsulated in frame 1514. In an embodiment, STA 1506 supporting NPCA operation comprises STA 1506 being capable of operating according to NPCA operation. In an embodiment, STA 1506 supporting the NPCA operation comprises (implicitly indicates) STA 1506 enabling / activating NPCA operation. In an embodiment, according to NPCA operation, STA 1506 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, the third field is set to a first value (e.g., 1) to indicate that STA 1506 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1506 does not support NPCA operation. In embodiment, the second TDLS frame comprises a third capabilities element comprising the third field. The third capabilities element may comprise a UHR capabilities element. The UHR capabilities element may comprise a UHR capabilities information field comprising the third field. In an embodiment, the third field comprises an NPCA support field.

[0163] In an embodiment, the second TDLS frame transmitted by STA 1506 may further comprise a fourth field that indicates whether STA 1506 enables / activates NPCA operation. In an embodiment, the fourth field comprises an NPCA Operation Information Present field. In an embodiment, the fourth field is set to a first value (e.g., 1) to indicate that STA 1506 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1506 disables / deactivates NPCA operation. In embodiment, the second TDLS frame comprises a fourth capabilities (or operation) element comprising the fourth field. The fourth capabilities (orDocket No.: 25-3002PCToperation) element may comprise a UHR capabilities (or UHR operation) element. The fourth capabilities element may be the same as the third capabilities element comprising the third field.

[0164] In an embodiment, the second TDLS frame transmitted by STA 1506 may further comprise one or more second NPCA-related parameters. The one or more second NPCA-related parameters may comprise a second NPCA switching delay, a second NPCA switching back delay, a second NPCA minimum duration threshold, and the NPCA primary channel of STA 1506.

[0165] Returning to FIG. 15, on receiving frame 1514, AP 1502 determines, based on the destination address of TDLS setup response frame 1516 that TDLS setup response frame 1516, encapsulated in frame 1514, is intended for STA 1504. AP 1502 extracts TDLS setup response frame 1516 from frame 1514 and encapsulates TDLS setup response frame 1516 in a frame 1518, which AP 1502 transmits to STA 1504 via the PCH. Frame 1518 may be a data frame. AP 1502 sets an RA of frame 1518 to an address (e.g., MAC address) of STA 1504.

[0166] On receiving TDLS setup response frame 1516 (and assuming that TDLS setup response frame 1516 comprises a status code equal to SUCCESS), STA 1504 transmits a TDLS setup confirm frame (not shown in FIG. 15) with status code equal to SUCCESS to STA 1506. This establishes a TDLS direct link between STA 1504 and STA 1506 and STAs 1504 and 1506 become TDLS peer ST As. In an embodiment, the TDLS setup confirm frame comprises a fifth field that indicates whether STA 1504 supports NPCA operation. In an embodiment, the fifth field is set to a first value (e.g., 1) to indicate that STA 1504 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 does not support NPCA operation. In embodiment, the TDLS setup confirm frame comprises a fifth capabilities element comprising the fifth field. The fifth capabilities element may comprise a UHR capabilities element. In an embodiment, the TDLS setup confirm frame transmitted by STA 1504 may further comprise a sixth field that indicates whether STA 1504 enables / activates NPCA operation. In an embodiment, the sixth field is set to a first value (e.g., 1) to indicate that STA 1504 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 disables / deactivates NPCA operation. In an embodiment, the sixth field comprises an “NPCA Operation Information Present” field. In embodiment, the TDLS setup confirm frame comprises a sixth capabilities (or operation) element comprising the sixth field. The sixth capabilities (or operation) element may comprise a UHR capabilities (or UHR operation) element. The sixth capabilities element may be the same as the fifth capabilities element comprising the fifth field. In an embodiment, the TDLS setup confirm frame comprises the one or more first NPCA-related parameters of STA 1504.

[0167] In an embodiment, STA 1504 may be configured to determine whether to switch from the PCH to the NPCA PCH based on the first field. In an embodiment, STA 1504 may be configured to switch from the PCH to the NPCA PCH based on the first field. Specifically, after determining that a PPDU 1520 being received via the PCH comprises an inter-BSS PPDU, STA 1504 may be configured to switch from the PCH to the NPCA PCH when the first field indicates that STA 1504 supports NPCA operation and to not switchDocket No.: 25-3002PCTfrom the PCH to the NPCA PCH when the first field indicates that STA 1504 does not support NPCA operation. As STA 1504 signals the first field to STA 1506, STA 1504 may switch from the PCH to the NPCA PCH based on the first field without risking STA 1506 (with which STA 1504 has an established TDLS direct link) attempting to communicate with STA 1504 via the TDLS direct link after STA 1504 switches from the PCH to the NPCA PCH (after detecting inter-BSS PPDU 1520 on the PCH). Similarly, STA 1506 may be configured to determine whether to switch from the PCH to the NPCA PCH based on the third field. In an embodiment, STA 1506 may be configured to switch from the PCH to the NPCA PCH based on the third field. Specifically, after determining that PPDU 1520 being received via the PCH comprises an inter-BSS PPDU, STA 1506 may be configured to switch from the PCH to the NPCA PCH when the third field indicates that STA 1506 supports NPCA operation and to not switch from the PCH to the NPCA PCH when the third field indicates that STA 1506 does not support NPCA operation. As STA 1506 signals the third field to STA 1504, STA 1506 may switch from the PCH to the NPCA PCH based on the third field without risking STA 1504 (with which STA 1506 has an established TDLS direct link) attempting to communicate with STA 1506 via the TDLS direct link after STA 1506 switches from the PCH to the NPCA PCH (after detecting inter-BSS PPDU 1520 on the PCH).

[0168] In another embodiment, STA 1504 may be configured to determine whether to switch from the PCH to the NPCA PCH based on the third field. In an embodiment, STA 1504 may be configured to switch from the PCH to the NPCA PCH based on the third field. Specifically, in an embodiment, where the first field indicates that STA 1504 supports PCA operation, after determining that PPDU 1529 being received via the PCH comprises an inter-BSS PPDU, STA 1504 may be configured to switch from the PCH to the NPCA PCH based on the third field indicating that STA 1506 supports NPCA operation. Conversely, where the first field indicates that STA 1504 supports PCA operation, after determining that PPDU 1520 being received via the PCH comprises an inter-BSS PPDU, STA 1504 may be configured not to switch from the PCH to the NPCA PCH based on the third field indicating that STA 1506 does not support NPCA operation. As such, STA 1504 ensures that STA 1504 switches from the PCH to the NPCA PCH only when STA 1506 is configured to switch from the PCH to the NPCA PCH (on detecting inter-BSS PPDU 1520). STA 1504 therefore remains on the same channel as STA 1506, with which STA 1504 established a TDLS direct link. Similarly, STA 1506 may be configured to determine whether to switch from the PCH to the NPCA PCH based on the first field. In an embodiment, STA 1506 may be configured to switch from the PCH to the NPCA PCH based on the first field. Specifically, in an embodiment, where the third field indicates that STA 1506 supports NPCA operation, after determining that PPDU 1520 being received via the PCH comprises an inter-BSS PPDU, STA 1506 may be configured to switch from the PCH to the NPCA PCH based on the first field indicating that STA 1504 supports NPCA operation. Conversely, where the third field indicates that STA 1506 supports NPCA operation, after determining that PPDU 1520 being received via the PCH comprises an inter-BSS PPDU, STA 1506 may be configured not to switch from the PCH to the NPCA PCH based on the first field indicating that STA 1504Docket No.: 25-3002PCTdoes not support NPCA operation. As such, STA 1506 ensures that STA 1506 switches from the PCH to the NPCA PCH only when STA 1504 is configured to switch from the PCH to the NPCA PCH (on detecting inter-BSS PPDU 1520). STA 1506 therefore remains on the same channel as STA 1504, with which STA 1506 established a TDLS direct link.

[0169] In another embodiment, STA 1504 may be configured to determine whether to switch from the PCH to the NPCA PCH based on the first field and the third field. In an embodiment, STA 1504 may be configured to switch from the PCH to the NPCA PCH based on the first field and the third field.

[0170] In an embodiment, where the first field indicates that STA 1504 supports NPCA operation and the third field indicates that STA 1506 supports NPCA operation, STA 1504 may be configured to switch from the PCH to the NPCA PCH based on determining that a PPDU being received via the PCH comprises an inter-BSS PPDU. As such, in example 1500, STA 1504 switches from the PCH to the NPCA PCH based on detecting inter-BSS PPDU 1520 on the PCH. In an embodiment, after receiving the third field, STA 1504 may be configured to transmit a frame indicating enablement / activation of NPCA operation by STA 1504 (e.g., if NPCA operation was previously disabled by STA 1504). In an embodiment, the frame indicating enablement / activation of NPCA operation may comprise a reassociation request frame indicating that STA 1504 supports NPCA operation.

[0171] In another embodiment, where the third field indicates that STA 1506 does not support NPCA operation, STA 1504 may be configured not to switch from the PCH to the NPCA PCH based on the determining a PPDU being received via the PCH comprises an inter-BSS PPDU. As such, in example 1500, STA 1504 does not switch from the PCH to the NPCA PCH based on detecting inter-BSS PPDU 1520 on the PCH. In an embodiment, after receiving the third field, STA 1504 may be configured to transmit a frame indicating disablement / deactivation of NPCA operation by STA 1504 (e.g., if NPCA operation was previously enabled by STA 1504). In an embodiment, the frame indicating disablement / deactivation of NPCA operation may comprise a reassociation request frame indicating that STA 1504 does not support NPCA operation.

[0172] FIG. 16 shows an example 1600 of another procedure 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 1502 and STAs 1504 and 1506 described above. STAs 1504 and 1506 may be associated with AP 1502 and may therefore belong to the same BSS as AP 1502. STAs 1504 and 1506 support TDLS operation as described in FIG. 13 above. Each of AP 1502, STA 1504, and STA 1506 may comprise an MLD.

[0173] Example 1600 may begin with STA 1504 transmitting a frame 1602 to AP 1502. Frame 1602 may be similar to frame 1508 described with reference to FIG. 15 above. Frame 1602 encapsulates a TDLS frame 1604 for STA 1506. STA 1504 may set a receiver address (RA) of frame 1602 to an address (e.g., MAC address) of AP 1502 or the BSSID of the BSS of which STA 1504 is a member. STA 1504 may set a destination address (DA) of TDLS frame 1604 to an address (e.g., MAC address) of STA 1506. TDLS frameDocket No.: 25-3002PCT1604 may be similar to TDLS frame 1510 described with reference to FIG. 15 above. Specifically, in an embodiment (not shown in FIG. 16), TDLS frame 1604 comprises a TDLS Discover Request frame, which STA 1504 transmits to discover whether STA 1506 supports TDLS. In another embodiment (illustrated in FIG. 16), TDLS frame 1604 comprises a TDLS setup request frame.

[0174] On receiving frame 1602, AP 1502 determines, based on a destination address of TDLS frame 1604, that TDLS frame 1604, encapsulated in frame 1604, is intended for STA 1506. AP 1502 extracts TDLS frame 1604 from frame 1602 and encapsulates TDLS frame 1604 in a frame 1606, which AP 1502 transmits to STA 1506 via the PCH. Frame 1606 may be similar to frame 1512 described with reference to FIG. 15 above.

[0175] Like TDLS frame 1510 described above, TDLS frame 1604 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1602 or frame 1606, comprises a first field that indicates whether STA 1504 supports NPCA operation. In an embodiment, STA 1504 supporting NPCA operation comprises STA 1504 being capable of operating according to NPCA operation. In an embodiment, STA 1504 supporting the NPCA operation comprises (implicitly indicates) STA 1504 enabling / activating NPCA operation. In an embodiment, according to NPCA operation, STA 1504 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, the first field is set to a first value (e.g., 1) to indicate that STA 1504 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 does not support NPCA operation. In embodiment, TDLS frame 1604 comprises a first capabilities element comprising the first field. The first capabilities element may comprise an ultra-high reliability (UHR) capabilities element. The UHR capabilities element may comprise a UHR MAC capabilities information field comprising the first field. In an embodiment, the first field comprises an NPCA support field. In example 1600, it is assumed that the first field of TDLS frame 1604 is set to the first value, indicating that STA 1504 supports NPCA operation.

[0176] In an embodiment, like TDLS frame 1510 described above, TDLS frame 1604 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1602 or frame 1606, may further comprise a second field that indicates whether STA 1504 enables / activates NPCA operation. In an embodiment, the second field comprises an NPCA Operation Information Present field. In an embodiment, the second field is set to a first value (e.g., 1) to indicate that STA 1504 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 disables / deactivates NPCA operation. In embodiment, frame 1604 comprises a second capabilities (or operation) element comprising the second field. The second capabilities element may comprise a UHR capabilities (or UHR operation) element. In an embodiment, like TDLS frame 1510 described above, TDLS frame 1604 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1602 or frame 1606, may further comprise one or more first NPCA-related parameters. The one or more first NPCA-related parameters may comprise a first NPCA switching delay, a first NPCA switching back delay, a first NPCA minimum duration threshold, and the NPCA primary channel of STA 1504.Docket No.: 25-3002PCT

[0177] Returning to FIG. 16, on receiving frame 1606, STA 1506 determines that a BSSID indicated in (a BSSID field of a Link Identifier element of) TDLS frame 1604, encapsulated in frame 1606, matches the BSSID of the BSS of which STA 1506 is a member and that TDLS frame 1604 is sent by STA 1504. In response to TDLS frame 1604, STA 1506 transmits a second TDLS frame, directly or via AP 1502, to STA 1504.

[0178] In an embodiment (not shown in FIG. 16), where TDLS frame 1604 comprises a TDLS discovery request frame, STA 1506 responds to the TDLS discovery request frame by transmitting, directly to STA 1504, a TDLS discovery response frame as the second TDLS frame. The TDLS discovery response frame comprises a TDLS discovery response frame action field. The TDLS discovery response frame action field comprises a Link Identifier element. STA 1506 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1506 is a member. STA 1506 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1504. STA 1506 may set a TDLS responder STA address of the Link Identifier element to an address (e.g., MAC address) of STA 1506. The TDLS discovery response frame action field further comprises a capability field that indicates the capabilities of STA 1506 and / or a Supported Channels element that indicates a list of channel subbands in which STA 1506 is capable of operating. In an embodiment, where STA 1506 supports NPCA operation, the list of channel subbands comprises the NPCA PCH. The TDLS discovery response frame action field may further comprise an Extended Capabilities element if any of the fields in this element are nonzero. The Extended Capabilities element may include a TDLS Support subfield set to 1 to indicate support for TDLS by STA 1506. The Extended Capabilities element may include a TDLS Channel Switching subfield set to 1 when TDLS channel switching is enabled by STA 1506.

[0179] In another embodiment (as illustrated in FIG. 16), where TDLS frame 1604 comprises a TDLS setup request frame, STA 1506 may accept the TDLS setup request frame by transmitting to STA 1504, via AP 1502, a TDLS setup response frame with a status code SUCCESS as the second TDLS frame. Alternatively, STA 1506 may decline the TDLS setup request frame by transmitting to STA 1504, via AP 1502, a TDLS setup response frame with a status code REQUEST_DECLINED. It is noted that STA 1506 declines a TDLS setup request frame when the BSSID indicated in (the BSSID field of the Link Identifier element of) the TDLS setup request frame does not match the BSSID of the BSS of which STA 1506 is a member. In an embodiment, STA 1506 accepts or declines the TDLS setup request frame based on the first field, the second field, and / or the one or more first NPCA-related parameters. For example, STA 1506 may accept the TDLS setup request frame based on the first field being set to the first value or may decline the TDLS setup request frame based on the first field being set to the second value, or vice versa. Alternatively, or additionally, STA 1506 may accept the TDLS setup request frame based on the third field being set to the first value or may decline the TDLS setup request frame based on the third field being set to the second value, or vice versa. Alternatively, or additionally, STA 1506 may accept or decline the TDLS setup request frame based on theDocket No.: 25-3002PCTone or more first NPCA-related parameters matching or not corresponding one or more second NPCA-related parameters of STA 1506.

[0180] In an embodiment, the second TDLS frame transmitted by STA 1506 (directly to STA 1504 or via AP 1502) comprises a third field that indicates whether STA 1506 supports NPCA operation. As described above, STA 1506 may transmit the second TDLS frame directly to STA 1504 in response to TDLS frame 1604 comprising a TDLS discovery request frame. In this case, the second TDLS frame comprises a TDLS discovery response frame. Alternatively, where TDLS frame 1604 comprises a TDLS setup request frame, STA 1506 may transmit the second TDLS frame via AP 1502. In this case, the second TDLS frame comprises TDLS setup response frame 1610 and is encapsulated in frame 1608. In an embodiment, STA 1506 supporting NPCA operation comprises STA 1506 being capable of operating according to NPCA operation. In an embodiment, STA 1506 supporting the NPCA operation comprises (implicitly indicates) STA 1506 enabling / activating NPCA operation In an embodiment, according to NPCA operation, STA 1506 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, the third field is set to a first value (e.g., 1) to indicate that STA 1506 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1506 does not support NPCA operation. In embodiment, the second TDLS frame comprises a third capabilities element comprising the third field. The third capabilities element may comprise a UHR capabilities element. The UHR capabilities element may comprise a UHR MAC capabilities information field comprising the third field. In an embodiment, the third field comprises an NPCA support field. In example 1600, it is assumed that the third field is set to the second value, indicating that STA 1506 does not support NPCA operation.

[0181] In an embodiment, the second TDLS frame transmitted by STA 1506 may further comprise a fourth field that indicates whether STA 1506 enables / activates NPCA operation. In an embodiment, the fourth field comprises an NPCA Operation Information Present field. In an embodiment, the fourth field is set to a first value (e.g., 1) to indicate that STA 1506 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1506 disables / deactivates NPCA operation. In embodiment, the second TDLS frame comprises a fourth capabilities (or operation) element comprising the fourth field. The fourth capabilities (or operation) element may comprise a UHR capabilities (or UHR operation) element. The fourth capabilities element may be the same as the third capabilities element comprising the third field. In an embodiment, the second TDLS frame transmitted by STA 1506 may further comprise one or more second NPCA-related parameters. The one or more second NPCA-related parameters may comprise a second NPCA switching delay, a second NPCA switching back delay, a second NPCA minimum duration threshold, and the NPCA primary channel of STA 1506.

[0182] Returning to FIG. 16, in example 1600, STA 1506 accepts the TDLS setup request frame comprised in TDLS frame 1604 and transmits to STA 1504, via AP 1502, a TDLS setup response frame 1610 with a status code SUCCESS. As shown, STA 1506 encapsulates TDLS setup response frame 1610 in a frameDocket No.: 25-3002PCT1608 that STA 1506 transmits to AP 1502. Frame 1608 may be similar to frame 1514 described with reference to FIG. 15 above. TDLS setup response frame 1610 may be similar to TDLS setup response frame 1516 described with reference to FIG. 15 above. In example 1600, the third field of TDLS setup response frame 1610 is set to the second value, indicating that STA 1506 does not support NPCA operation.

[0183] On receiving frame 1608, AP 1502 determines, based on a destination address of TDLS setup response frame 1610, that TDLS setup response frame 1610, encapsulated in frame 1608, is intended for STA 1504. AP 1502 extracts TDLS setup response frame 1610 from frame 1608 and encapsulates TDLS setup response frame 1610 in a frame 1612, which AP 1502 transmits to STA 1504 via the PCH. Frame 1612 may be similar to frame 1518 described with reference to FIG. 15 above.

[0184] On receiving TDLS setup response frame 1610 (and assuming that TDLS setup response frame 1610 comprises a status code equal to SUCCESS), STA 1504 transmits a TDLS setup confirm frame (not shown in FIG. 16) with status code equal to SUCCESS to STA 1506. This establishes a TDLS direct link between STA 1504 and STA 1506 and STAs 1504 and 1506 become TDLS peer ST As. In an embodiment, the TDLS setup confirm frame comprises a fifth field that indicates whether STA 1504 supports NPCA operation. In an embodiment, the fifth field is set to a first value (e.g., 1) to indicate that STA 1504 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 does not support NPCA operation. In embodiment, the TDLS setup confirm frame comprises a fifth capabilities element comprising the fifth field. The fifth capabilities element may comprise a UHR capabilities element. In an embodiment, the TDLS setup confirm frame transmitted by STA 1504 may further comprise a sixth field that indicates whether STA 1504 enables / activates NPCA operation. In an embodiment, the sixth field is set to a first value (e.g., 1) to indicate that STA 1504 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 disables / deactivates NPCA operation. In an embodiment, the sixth field comprises an “NPCA Operation Information Present” field. In embodiment, the TDLS setup confirm frame comprises a sixth capabilities (or operation) element comprising the sixth field. The sixth capabilities (or operation) element may comprise a UHR capabilities (or UHR operation) element. The sixth capabilities element may be the same as the fifth capabilities element comprising the fifth field. In an embodiment, the TDLS setup confirm frame comprises the one or more first NPCA-related parameters of STA 1504.

[0185] In an embodiment, assuming STA 1504 supports NPCA operation, STA 1504 may enable or disable NPCA operation based on: the third field, the fourth field, and / or the one or more second NPCA-related parameters of STA 1506 indicated in the second TDLS frame transmitted by STA 1506. In example 1600, the second TDLS frame corresponds to TDLS setup response frame 1610. In an embodiment, STA 1504 may enable NPCA operation based on the third field indicating that STA 1506 supports NPCA operation and / or the fourth field indicating that STA 1506 enables NPCA operation. Conversely, STA 1504 may disable NPCA operation based on the third field indicating that STA 1506 does not support NPCA operation and / or the fourth field indicating that STA 1506 disables NPCA operation. In another embodiment, STA 1506 mayDocket No.: 25-3002PCTenable NPCA operation based on the one or more second NPCA-related parameters of STA 1506 matching the one or more first NPCA-related parameters of STA 1504. Conversely, STA 1506 may disable NPCA operation based on (at least one of) the one or more second NPCA-related parameters of STA 1506 not matching (at least one of) the one or more first NPCA-related parameters of STA 1504.

[0186] In example 1600, TDLS setup response frame 1610, as encapsulated in frame 1608 or frame 1612, comprises the third field indicating that STA 1506 does not support NPCA operation. Accordingly, STA 1504 may disable NPCA operation at STA 1504. In an embodiment, STA 1504 may transmit a frame 1614 indicating disabling of NPCA operation at STA 1504. In an embodiment, STA 1504 may transmit frame 1614 to AP 1502. Frame 1614 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, frame 1614 may comprise an association request frame, a reassociation request frame, or a probe request frame that indicates that STA 1504 does not support NPCA operation. For example, frame 1614 may comprise an NPCA support field set to a value indicating that STA 1504 does not support PCA operation.

[0187] Subsequently, in an example, transmission of an inter-BSS PPDU 1616 may be initiated on the PCH. On detecting inter-BSS PPDU 1616, AP 1502 switches from the PCH to the NPCA PCH and sets a NAV for the PCH based on inter-BSS PPDU 1616. STA 1504 detects inter-BSS PPDU 1616 on the PCH. STA 1504 sets a NAV for the PCH based on inter-BSS PPDU 1616. But having disabled NPCA operation, STA 1504 does not switch from the PCH to the NPCA PCH based on detecting inter-BSS PPDU 1616. Instead, STA 1504 remains on the PCH. In an example (as shown in FIG. 16), STA 1506 does not detect inter-BSS PPDU 1616 and does not set a NAV for the PCH based on inter-BSS PPDU 1616. As such, STA 1506 may transmit a data frame 1618 via the established TDLS direct link, on the PCH, to STA 1504. As STA 1504 remains on the PCH, STA 1504 may receive data frame 1618 from STA 1506. STA 1504 may respond to data frame 1618 by transmitting a BlockAck (BA) frame 1620 via the TDLS direct link to STA 1506. It is noted that STA 1504 may be allowed to transmit BA frame 1620, despite having a non-zero NAV for the PCH, as a response to data frame 1618.

[0188] FIG. 17 shows an example 1700 of another procedure according to an embodiment. Example 1700 is provided for the purpose of illustration only and is not limiting of embodiments. As shown in FIG. 17, example 1700 also includes AP 1502 and STAs 1504 and 1506 described above. STAs 1504 and 1506 may be associated with AP 1502 and may therefore belong to the same BSS as AP 1502. STAs 1504 and 1506 support TDLS operation as described in FIG. 13 above. Each of AP 1502, STA 1504, and STA 1506 may comprise an MLD.

[0189] Example 1700 may begin with STA 1504 transmitting a frame 1702 to AP 1502. Frame 1702 may be similar to frame 1508 described with reference to FIG. 15 above. Frame 1702 encapsulates a TDLS frame 1704 for STA 1506. STA 1504 may set a receiver address (RA) of frame 1702 to an address (e.g., MACDocket No.: 25-3002PCTaddress) of AP 1502 or the BSSID of the BSS of which STA 1504 is a member. STA 1504 may set a destination address (DA) of TDLS frame 1704 to an address (e.g., MAC address) of STA 1506. TDLS frame 1704 may be similar to TDLS frame 1510 described with reference to FIG. 15 above. Specifically, in an embodiment (not shown in FIG. 17), TDLS frame 1704 comprises a TDLS Discover Request frame, which STA 1504 transmits to discover whether STA 1506 supports TDLS. In another embodiment (illustrated in FIG. 17), TDLS frame 1704 comprises a TDLS setup request frame.

[0190] On receiving frame 1702, AP 1502 determines, based on a destination address of TDLS frame 1704, that TDLS frame 1704, encapsulated in frame 1704, is intended for STA 1506. AP 1502 extracts TDLS frame 1704 from frame 1702 and encapsulates TDLS frame 1704 in a frame 1706, which AP 1502 transmits to STA 1506 via the PCH. Frame 1706 may be similar to frame 1512 described with reference to FIG. 15 above.

[0191] Like TDLS frame 1510 described above, TDLS frame 1704 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1702 or frame 1706, comprises a first field that indicates whether STA 1504 supports NPCA operation. In an embodiment, STA 1504 supporting NPCA operation comprises STA 1504 being capable of operating according to NPCA operation. In an embodiment, STA 1504 supporting the NPCA operation comprises (implicitly indicates) STA 1504 enabling / activating NPCA operation. In an embodiment, according to NPCA operation, STA 1504 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, the first field is set to a first value (e.g., 1) to indicate that STA 1504 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 does not support NPCA operation. In embodiment, TDLS frame 1704 comprises a first capabilities element comprising the first field. The first capabilities element may comprise an ultra-high reliability (UHR) capabilities element. The UHR capabilities element may comprise a UHR capabilities information field comprising the first field. In an embodiment, the first field comprises an NPCA support field. In example 1700, it is assumed that the first field of TDLS frame 1704 is set to the first value, indicating that STA 1504 supports NPCA operation.

[0192] In an embodiment, like TDLS frame 1510 described above, TDLS frame 1704 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1702 or frame 1706, may further comprise a second field that indicates whether STA 1504 enables / activates NPCA operation. In an embodiment, the second field comprises an NPCA Operation Information Present field. In an embodiment, the second field is set to a first value (e.g., 1) to indicate that STA 1504 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 disables / deactivates NPCA operation. In embodiment, frame 1704 comprises a second capabilities (or operation) element comprising the second field. The second capabilities element may comprise a UHR capabilities (or UHR operation) element. In an embodiment, like TDLS frame 1510 described above, TDLS frame 1704 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1702 or frame 1706, may further comprise one or more first NPCA-related parameters. The one or more first NPCA-related parameters may comprise a first NPCADocket No.: 25-3002PCTswitching delay, a first NPCA switching back delay, a first NPCA minimum duration threshold, and the NPCA primary channel of STA 1504.

[0193] Returning to FIG 17, on receiving frame 1706, STA 1506 determines that a BSSID indicated in (a BSSID field of a Link Identifier element of) TDLS frame 1704, encapsulated in frame 1706, matches the BSSID of the BSS of which STA 1506 is a member and that TDLS frame 1704 is sent by STA 1504. In response to TDLS frame 1704, STA 1506 transmits a second TDLS frame, directly or via AP 1502, to STA 1504.

[0194] In an embodiment (not shown in FIG. 17), where TDLS frame 1704 comprises a TDLS discovery request frame, STA 1506 responds to the TDLS discovery request frame by transmitting, directly to STA 1504, a TDLS discovery response frame as the second TDLS frame. The TDLS discovery response frame comprises a TDLS discovery response frame action field. The TDLS discovery response frame action field comprises a Link Identifier element. STA 1506 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1506 is a member. STA 1506 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1504. STA 1506 may set a TDLS responder STA address of the Link Identifier element to an address (e.g., MAC address) of STA 1506. The TDLS discovery response frame action field further comprises a Capability field that indicates the capabilities of STA 1506 and a Supported Channels element that indicates a list of channel subbands in which STA 1506 is capable of operating. In an embodiment, where STA 1506 supports NPCA operation, the list of channel subbands comprises the NPCA PCH. The TDLS discovery response frame action field may further comprise an Extended Capabilities element if any of the fields in this element are nonzero. The Extended Capabilities element may include a TDLS Support subfield set to 1 to indicate support for TDLS by STA 1506. The Extended Capabilities element may include a TDLS Channel Switching subfield set to 1 when TDLS channel switching is enabled by STA 1506.

[0195] In another embodiment (as illustrated in FIG. 17), where TDLS frame 1704 comprises a TDLS setup request frame, STA 1506 may accept the TDLS setup request frame by transmitting to STA 1504, via AP 1502, a TDLS setup response frame with a status code SUCCESS as the second TDLS frame. Alternatively, STA 1506 may decline the TDLS setup request frame by transmitting to STA 1504, via AP 1502, a TDLS setup response frame with a status code REQUEST_DECLINED. It is noted that STA 1506 declines a TDLS setup request frame when the BSSID indicated in (the BSSID field of the Link Identifier element of) the TDLS setup request frame does not match the BSSID of the BSS of which STA 1506 is a member. In an embodiment, STA 1506 accepts or declines the TDLS setup request frame based on the first field, the second field, and / or the one or more first NPCA-related parameters. For example, STA 1506 may accept the TDLS setup request frame based on the first field being set to the first value or may decline the TDLS setup request frame based on the first field being set to the second value, or vice versa. Alternatively, or additionally, STA 1506 may accept the TDLS setup request frame based on the third field being set to the first value or mayDocket No.: 25-3002PCTdecline the TDLS setup request frame based on the third field being set to the second value, or vice versa. Alternatively, or additionally, STA 1506 may accept or decline the TDLS setup request frame based on the one or more first NPCA-related parameters matching or not corresponding second NPCA-related parameters of STA 1506.

[0196] In an embodiment, the second TDLS frame transmitted by STA 1506 (directly to STA 1504 or via AP 1502) comprises a third field that indicates whether STA 1506 supports NPCA operation. As described above, STA 1506 may transmit the second TDLS frame directly to STA 1504 in response to TDLS frame 1704 comprising a TDLS discovery request frame. In this case, the second TDLS frame comprises a TDLS discovery response frame. Alternatively, where TDLS frame 1704 comprises a TDLS setup request frame, STA 1506 may transmit the second TDLS frame via AP 1502. In this case, the second TDLS frame comprises TDLS setup response frame 1710 and is encapsulated in frame 1708. In an embodiment, STA 1506 supporting NPCA operation comprises STA 1506 being capable of operating according to NPCA operation. In an embodiment, STA 1506 supporting the NPCA operation comprises (implicitly indicates) STA 1506 enabling / activating NPCA operation. In an embodiment, according to NPCA operation, STA 1506 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, the third field is set to a first value (e.g., 1) to indicate that STA 1506 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1506 does not support NPCA operation. In embodiment, the second TDLS frame comprises a third capabilities element comprising the third field. The third capabilities element may comprise a UHR capabilities element. The UHR capabilities element may comprise a UHR capabilities information field comprising the third field. In an embodiment, the third field comprises an NPCA support field In example 1700, it is assumed that the third field is set to the first value, indicating that STA 1506 supports NPCA operation.

[0197] In an embodiment, the second TDLS frame transmitted by STA 1506 may further comprise a fourth field that indicates whether STA 1506 enables / activates NPCA operation. In an embodiment, the fourth field comprises an NPCA Operation Information Present field. In an embodiment, the fourth field is set to a first value (e.g., 1) to indicate that STA 1506 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1506 disables / deactivates NPCA operation. In embodiment, the second TDLS frame comprises a fourth capabilities (or operation) element comprising the fourth field. The fourth capabilities (or operation) element may comprise a UHR capabilities (or UHR operation) element. The fourth capabilities element may be the same as the third capabilities element comprising the third field. In an embodiment, the second TDLS frame transmitted by STA 1506 may further comprise one or more second NPCA-related parameters. The one or more second NPCA-related parameters may comprise a second NPCA switching delay, a second NPCA switching back delay, a second NPCA minimum duration threshold, and the NPCA primary channel of STA 1506.Docket No.: 25-3002PCT

[0198] Returning to FIG. 17, in example 1700, STA 1506 accepts the TDLS setup request frame comprised in TDLS frame 1704 and transmits to STA 1504, via AP 1502, a TDLS setup response frame 1710 with a status code SUCCESS. As shown, STA 1506 encapsulates TDLS setup response frame 1710 in a frame 1708 that STA 1506 transmits to AP 1502. Frame 1708 may be similar to frame 1514 described with reference to FIG. 15 above. TDLS setup response frame 1710 may be similar to TDLS setup response frame 1517 described with reference to FIG. 15 above. In example 1700, the third field of TDLS setup response frame 1710 is set to the first value, indicating that STA 1506 supports NPCA operation.

[0199] On receiving frame 1708, AP 1502 determines, based on a destination address of TDLS setup response frame 1710, that TDLS setup response frame 1710, encapsulated in frame 1708, is intended for STA 1504. AP 1502 extracts TDLS setup response frame 1710 from frame 1708 and encapsulates TDLS setup response frame 1710 in a frame 1712, which AP 1502 transmits to STA 1504 via the PCH. Frame 1712 may be similar to frame 1518 described with reference to FIG. 15 above.

[0200] On receiving TDLS setup response frame 1710 (and assuming that TDLS setup response frame 1710 comprises a status code equal to SUCCESS), STA 1504 transmits a TDLS setup confirm frame (not shown in FIG. 17) with status code equal to SUCCESS to STA 1506. This establishes a TDLS direct link between STA 1504 and STA 1506 and STAs 1504 and 1506 become TDLS peer ST As. In an embodiment, the TDLS setup confirm frame comprises a fifth field that indicates whether STA 1504 supports NPCA operation. In an embodiment, the fifth field is set to a first value (e.g., 1) to indicate that STA 1504 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 does not support NPCA operation. In embodiment, the TDLS setup confirm frame comprises a fifth capabilities element comprising the fifth field. The fifth capabilities element may comprise a UHR capabilities element. In an embodiment, the TDLS setup confirm frame transmitted by STA 1504 may further comprise a sixth field that indicates whether STA 1504 enables / activates NPCA operation. In an embodiment, the sixth field is set to a first value (e.g., 1) to indicate that STA 1504 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 disables / deactivates NPCA operation. In an embodiment, the sixth field comprises an “NPCA Operation Information Present” field. In embodiment, the TDLS setup confirm frame comprises a sixth capabilities (or operation) element comprising the sixth field. The sixth capabilities (or operation) element may comprise a UHR capabilities (or UHR operation) element. The sixth capabilities element may be the same as the fifth capabilities element comprising the fifth field. In an embodiment, the TDLS setup confirm frame comprises the one or more first NPCA-related parameters of STA 1504.

[0201] In an embodiment, assuming STA 1504 supports NPCA operation, STA 1504 may enable or disable NPCA operation based on: the third field, the fourth field, and / or the one or more second NPCA-related parameters of STA 1506 indicated in the second TDLS frame transmitted by STA 1506. In example 1700, the second TDLS frame corresponds to TDLS setup response frame 1710. In an embodiment, STA 1504 may enable NPCA operation based on the third field indicating that STA 1506 supports NPCA operationDocket No.: 25-3002PCTand / or the fourth field indicating that STA 1506 enables NPCA operation. Conversely, STA 1504 may disable NPCA operation based on the third field indicating that STA 1506 does not support NPCA operation and / or the fourth field indicating that STA 1506 disables NPCA operation. In another embodiment, STA 1506 may enable NPCA operation based on the one or more second NPCA-related parameters of STA 1506 matching the one or more first NPCA-related parameters of STA 1504. Conversely, STA 1506 may disable NPCA operation based on (at least one of) the one or more second NPCA-related parameters of STA 1506 not matching (at least one of) the one or more first NPCA-related parameters of STA 1504.

[0202] In example 1700, TDLS setup response frame 1710, as encapsulated in frame 1708 or frame 1712, comprises the third field indicating that STA 1506 supports NPCA operation and the fourth field indicating that STA 1506 disables NPCA operation. Accordingly, STA 1504 may disable NPCA operation at STA 1504. In an embodiment, STA 1504 may transmit a frame 1714 indicating disabling of NPCA operation at STA 1504. In an embodiment, STA 1504 may transmit frame 1714 to AP 1502. Frame 1714 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, frame 1714 may comprise an association request frame, a reassociation request frame, or a probe request frame that indicates that STA 1504 does not support NPCA operation. For example, frame 1714 may comprise an NPCA support field set to a value indicating that STA 1504 does not support NPCA operation.

[0203] Subsequently, in an example, transmission of an inter-BSS PPDU 1716 may be initiated on the PCH. On detecting inter-BSS PPDU 1716, AP 1502 switches from the PCH to the NPCA PCH and sets a NAV for the PCH based on inter-BSS PPDU 1716. STA 1504 detects inter-BSS PPDU 1716 on the PCH. STA 1504 sets a NAV for the PCH based on inter-BSS PPDU 1716. But having disabled NPCA operation, STA 1504 does not switch from the PCH to the NPCA PCH based on detecting inter-BSS PPDU 1716. Instead, STA 1504 remains on the PCH. In an example (as shown in FIG. 17), STA 1506 does not detect inter-BSS PPDU 1716 and does not set a NAV for the PCH based on inter-BSS PPDU 1716. As such, STA 1506 may transmit a data frame 1718 via the established TDLS direct link, on the PCH, to STA 1504. As STA 1504 remains on the PCH, STA 1504 may receive data frame 1718 from STA 1506. STA 1504 may respond to data frame 1718 by transmitting a BlockAck (BA) frame 1720 via the TDLS direct link to STA 1506. It is noted that STA 1504 may be allowed to transmit BA frame 1720, despite having a non-zero NAV for the PCH, as a response to data frame 1718.

[0204] FIG. 18 shows an example 1800 of another procedure according to an embodiment. Example 1800 is provided for the purpose of illustration only and is not limiting of embodiments. As shown in FIG. 18, example 1800 also includes AP 1502 and STAs 1504 and 1506 described above. STAs 1504 and 1506 may be associated with AP 1502 and may therefore belong to the same BSS as AP 1502. STAs 1504 and 1506Docket No.: 25-3002PCTsupport TDLS operation as described in FIG. 13 above. Each of AP 1502, STA 1504, and STA 1506 may comprise an MLD.

[0205] Example 1800 may begin with STA 1504 transmitting a frame 1802 to AP 1502. Frame 1802 may be similar to frame 1508 described with reference to FIG. 15 above. Frame 1802 encapsulates a TDLS frame 1804 for STA 1506. STA 1504 may set a receiver address (RA) of frame 1802 to an address (e.g., MAC address) of AP 1502 or the BSSID of the BSS of which STA 1504 is a member. STA 1504 may set a destination address (DA) of TDLS frame 1804 to an address (e.g., MAC address) of STA 1506. TDLS frame 1804 may be similar to TDLS frame 1510 described with reference to FIG. 15 above. Specifically, in an embodiment (not shown in FIG. 18), TDLS frame 1804 comprises a TDLS Discover Request frame, which STA 1504 transmits to discover whether STA 1506 supports TDLS. In another embodiment (illustrated in FIG. 18), TDLS frame 1804 comprises a TDLS setup request frame.

[0206] On receiving frame 1802, AP 1502 determines, based on a destination address of TDLS frame 1804, that TDLS frame 1804, encapsulated in frame 1804, is intended for STA 1506. AP 1502 extracts TDLS frame 1804 from frame 1802 and encapsulates TDLS frame 1804 in a frame 1806, which AP 1502 transmits to STA 1506 via the PCH. Frame 1806 may be similar to frame 1512 described with reference to FIG. 15 above.

[0207] Like TDLS frame 1510 described above, TDLS frame 1804 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1802 or frame 1806, comprises a first field that indicates whether STA 1504 supports NPCA operation. In an embodiment, STA 1504 supporting NPCA operation comprises STA 1504 being capable of operating according to NPCA operation. In an embodiment, STA 1504 supporting the NPCA operation comprises (implicitly indicates) STA 1504 enabling / activating NPCA operation In an embodiment, according to NPCA operation, STA 1504 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, the first field is set to a first value (e.g., 1) to indicate that STA 1504 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 does not support NPCA operation. In embodiment, TDLS frame 1804 comprises a first capabilities element comprising the first field. The first capabilities element may comprise an ultra-high reliability (UHR) capabilities element. The UHR capabilities element may comprise a UHR capabilities information field comprising the first field. In an embodiment, the first field comprises an NPCA support field. In example 1800, it is assumed that the first field of TDLS frame 1804 is set to the first value, indicating that STA 1504 supports NPCA operation.

[0208] In an embodiment, like TDLS frame 1510 described above, TDLS frame 1804 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1802 or frame 1806, may further comprise a second field that indicates whether STA 1504 enables / activates NPCA operation. In an embodiment, the second field comprises an NPCA Operation Information Present field. In an embodiment, the second field is set to a first value (e.g., 1) to indicate that STA 1504 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 disables / deactivates NPCA operation. In embodiment,Docket No.: 25-3002PCTframe 1804 comprises a second capabilities (or operation) element comprising the second field. The second capabilities element may comprise a UHR capabilities (or UHR operation) element. In an embodiment, like TDLS frame 1510 described above, TDLS frame 1804 (whether as a TDLS discovery request frame or as a TDLS setup request frame), as encapsulated in frame 1802 or frame 1806, may further comprise one or more first NPCA-related parameters. The one or more first NPCA-related parameters may comprise a first NPCA switching delay, a first NPCA switching back delay, a first NPCA minimum duration threshold, and the NPCA primary channel of STA 1504.

[0209] Returning to FIG. 18, on receiving frame 1806, STA 1506 determines that a BSSID indicated in (a BSSID field of a Link Identifier element of) TDLS frame 1804, encapsulated in frame 1806, matches the BSSID of the BSS of which STA 1506 is a member and that TDLS frame 1804 is sent by STA 1504. In response to TDLS frame 1804, STA 1506 transmits a second TDLS frame, directly or via AP 1502, to STA 1504.

[0210] In an embodiment (not shown in FIG. 18), where TDLS frame 1804 comprises a TDLS discovery request frame, STA 1506 responds to the TDLS discovery request frame by transmitting, directly to STA 1504, a TDLS discovery response frame as the second TDLS frame. The TDLS discovery response frame comprises a TDLS discovery response frame action field. The TDLS discovery response frame action field comprises a Link Identifier element. STA 1506 may set a BSSID field of the Link Identifier element to the BSSID of the BSS of which STA 1506 is a member. STA 1506 may set a TDLS initiator STA Address of the Link Identifier element to an address (e.g., MAC address) of STA 1504. STA 1506 may set a TDLS responder STA address of the Link Identifier element to an address (e.g., MAC address) of STA 1506. The TDLS discovery response frame action field further comprises a Capability field that indicates the capabilities of STA 1506 and a Supported Channels element that indicates a list of channel subbands in which STA 1506 is capable of operating. In an embodiment, where STA 1506 supports NPCA operation, the list of channel subbands comprises the NPCA PCH. The TDLS discovery response frame action field may further comprise an Extended Capabilities element if any of the fields in this element are nonzero. The Extended Capabilities element may include a TDLS Support subfield set to 1 to indicate support for TDLS by STA 1506. The Extended Capabilities element may include a TDLS Channel Switching subfield set to 1 when TDLS channel switching is enabled by STA 1506.

[0211] In another embodiment (as illustrated in FIG. 18), where TDLS frame 1804 comprises a TDLS setup request frame, STA 1506 may accept the TDLS setup request frame by transmitting to STA 1504, via AP 1502, a TDLS setup response frame with a status code SUCCESS as the second TDLS frame. Alternatively, STA 1506 may decline the TDLS setup request frame by transmitting to STA 1504, via AP 1502, a TDLS setup response frame with a status code REQUEST_DECLINED. It is noted that STA 1506 declines a TDLS setup request frame when the BSSID indicated in (the BSSID field of the Link Identifier element of) the TDLS setup request frame does not match the BSSID of the BSS of which STA 1506 is a member. In anDocket No.: 25-3002PCTembodiment, STA 1506 accepts or declines the TDLS setup request frame based on the first field, the second field, and / or the one or more first NPCA-related parameters. For example, STA 1506 may accept the TDLS setup request frame based on the first field being set to the first value or may decline the TDLS setup request frame based on the first field being set to the second value, or vice versa. Alternatively, or additionally, STA 1506 may accept the TDLS setup request frame based on the third field being set to the first value or may decline the TDLS setup request frame based on the third field being set to the second value, or vice versa. Alternatively, or additionally, STA 1506 may accept or decline the TDLS setup request frame based on the one or more first NPCA-related parameters matching or not corresponding second NPCA-related parameters of STA 1506.

[0212] In an embodiment, the second TDLS frame transmitted by STA 1506 (directly to STA 1504 or via AP 1502) comprises a third field that indicates whether STA 1506 supports NPCA operation. As described above, STA 1506 may transmit the second TDLS frame directly to STA 1504 in response to TDLS frame 1804 comprising a TDLS discovery request frame. In this case, the second TDLS frame comprises a TDLS discovery response frame. Alternatively, where TDLS frame 1804 comprises a TDLS setup request frame, STA 1506 may transmit the second TDLS frame via AP 1502. In this case, the second TDLS frame comprises TDLS setup response frame 1810 and is encapsulated in frame 1808. In an embodiment, STA 1506 supporting NPCA operation comprises STA 1506 being capable of operating according to NPCA operation. In an embodiment, STA 1506 supporting the NPCA operation comprises (implicitly indicates) STA 1506 enabling / activating NPCA operation. In an embodiment, according to NPCA operation, STA 1506 switches from the PCH to the NPCA PCH based on detecting / receiving an inter-BSS PPDU on the PCH. In an embodiment, the third field is set to a first value (e.g., 1) to indicate that STA 1506 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1506 does not support NPCA operation. In embodiment, the second TDLS frame comprises a third capabilities element comprising the third field. The third capabilities element may comprise a UHR capabilities element. The UHR capabilities element may comprise a UHR capabilities information field comprising the third field. In an embodiment, the third field comprises an NPCA support field. In example 1800, it is assumed that the third field is set to the first value, indicating that STA 1506 supports NPCA operation.

[0213] In an embodiment, the second TDLS frame transmitted by STA 1506 may further comprise a fourth field that indicates whether STA 1506 enables / activates NPCA operation. In an embodiment, the fourth field comprises an NPCA Operation Information Present field. In an embodiment, the fourth field is set to a first value (e.g., 1) to indicate that STA 1506 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1506 disables / deactivates NPCA operation. In embodiment, the second TDLS frame comprises a fourth capabilities (or operation) element comprising the fourth field. The fourth capabilities (or operation) element may comprise a UHR capabilities (or UHR operation) element. The fourth capabilities element may be the same as the third capabilities element comprising the third field. In an embodiment, theDocket No.: 25-3002PCTsecond TDLS frame transmitted by STA 1506 may further comprise one or more second NPCA-related parameters. The one or more second NPCA-related parameters may comprise a second NPCA switching delay, a second NPCA switching back delay, a second NPCA minimum duration threshold, and the NPCA primary channel of STA 1506.

[0214] Returning to FIG. 18, in example 1800, STA 1506 accepts the TDLS setup request frame comprised in TDLS frame 1804 and transmits to STA 1504, via AP 1502, a TDLS setup response frame 1810 with a status code SUCCESS. As shown, STA 1506 encapsulates TDLS setup response frame 1810 in a frame 1808 that STA 1506 transmits to AP 1502. Frame 1808 may be similar to frame 1514 described with reference to FIG. 15 above. TDLS setup response frame 1810 may be similar to TDLS setup response frame 1516 described with reference to FIG. 15 above. In example 1800, the third field of TDLS setup response frame 1810 indicates that STA 1506 supports NPCA operation. Alternatively, or additionally, the fourth field of TDLS setup response frame 1810 indicates that STA 1506 enables NPCA operation.

[0215] On receiving frame 1808, AP 1502 determines, based on a destination address of TDLS setup response frame 1810, that TDLS setup response frame 1810, encapsulated in frame 1808, is intended for STA 1504. AP 1502 extracts TDLS setup response frame 1810 from frame 1808 and encapsulates TDLS setup response frame 1810 in a frame 1812, which AP 1502 transmits to STA 1504 via the PCH. Frame 1812 may be similar to frame 1518 described with reference to FIG. 15 above.

[0216] On receiving TDLS setup response frame 1810 (and assuming that TDLS setup response frame 1810 comprises a status code equal to SUCCESS), STA 1504 transmits a TDLS setup confirm frame (not shown in FIG. 18) with status code equal to SUCCESS to STA 1506. This establishes a TDLS direct link between STA 1504 and STA 1506 and STAs 1504 and 1506 become TDLS peer ST As. In an embodiment, the TDLS setup confirm frame comprises a fifth field that indicates whether STA 1504 supports NPCA operation. In an embodiment, the fifth field is set to a first value (e.g., 1) to indicate that STA 1504 supports NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 does not support NPCA operation. In embodiment, the TDLS setup confirm frame comprises a fifth capabilities element comprising the fifth field. The fifth capabilities element may comprise a UHR capabilities element. In an embodiment, the TDLS setup confirm frame transmitted by STA 1504 may further comprise a sixth field that indicates whether STA 1504 enables / activates NPCA operation. In an embodiment, the sixth field is set to a first value (e.g., 1) to indicate that STA 1504 enables / activates NPCA operation or to a second value (e.g. 0) to indicate that STA 1504 disables / deactivates NPCA operation In an embodiment, the sixth field comprises an “NPCA Operation Information Present” field. In embodiment, the TDLS setup confirm frame comprises a sixth capabilities (or operation) element comprising the sixth field. The sixth capabilities (or operation) element may comprise a UHR capabilities (or UHR operation) element. The sixth capabilities element may be the same as the fifth capabilities element comprising the fifth field. In an embodiment, the TDLS setup confirm frame comprises the one or more first NPCA-related parameters of STA 1504.Docket No.: 25-3002PCT

[0217] In an embodiment, assuming STA 1504 supports NPCA operation, STA 1504 may enable or disable NPCA operation based on: the third field, the fourth field, and / or the one or more second NPCA-related parameters of STA 1506 indicated in the second TDLS frame transmitted by STA 1506. In example 1800, the second TDLS frame corresponds to TDLS setup response frame 1810. In an embodiment, STA 1504 may enable NPCA operation based on the third field indicating that STA 1506 supports NPCA operation and / or the fourth field indicating that STA 1506 enables NPCA operation. Conversely, STA 1504 may disable NPCA operation based on the third field indicating that STA 1506 does not support NPCA operation and / or the fourth field indicating that STA 1506 disables NPCA operation. In another embodiment, STA 1506 may enable NPCA operation based on the one or more second NPCA-related parameters of STA 1506 matching the one or more first NPCA-related parameters of STA 1504. Conversely, STA 1506 may disable NPCA operation based on (at least one of) the one or more second NPCA-related parameters of STA 1506 not matching (at least one of) the one or more first NPCA-related parameters of STA 1504.

[0218] In example 1800, TDLS setup response frame 1810, as encapsulated in frame 1808 or frame 1812, comprises the third field indicating that STA 1506 supports NPCA operation and / or the fourth field indicating that STA 1506 enables NPCA operation. Accordingly, STA 1504 may enabled NPCA operation at STA 1504 (if not already enabled). In an embodiment, STA 1504 may transmit a frame 1814 indicating enabling of NPCA operation at STA 1504. In an embodiment, STA 1504 may transmit frame 1814 to AP 1502. Frame 1814 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, frame 1814 may comprise an association request frame, a reassociation request frame, or a probe request frame that indicates that STA 1504 supports NPCA operation. For example, frame 1814 may comprise an NPCA support field set to a value indicating that STA 1504 supports NPCA operation.

[0219] Subsequently, in an example, transmission of an inter-BSS PPDU 1816 may be initiated on the PCH. On detecting inter-BSS PPDU 1816, AP 1502 switches from the PCH to the NPCA PCH and sets a NAV for the PCH based on inter-BSS PPDU 1816. STA 1504 detects inter-BSS PPDU 1816 on the PCH. STA 1504 sets a NAV for the PCH based on inter-BSS PPDU 1816, and, having enabled NPCA operation, switches from the PCH to the NPCA PCH based on detecting inter-BSS PPDU 1816. Similarly, STA 1506 detects inter-BSS PPDU 1816 and sets a NAV for the PCH based on inter-BSS PPDU 1816, and switches from the PCH to the NPCA PCH based on detecting inter-BSS PPDU 1816. In an embodiment, STA 1506 switches from the PCH to the NPCA PCH based on detecting inter-BSS PPDU 1816 and having set the third field to indicate support of NPCA operation and / or the fourth field to indicate enablement of NPCA operation at STA 1506.

[0220] In an embodiment, based on receiving the first field and / or the second field (and / or frame 1814), STA 1506 is able to determine whether STA 1504 switches from the PCH to the NPCA PCH on detecting an inter-BSS PPDU on the PCH. Similarly, based on receiving the third field and / or the fourth field, STA 1504 is ableDocket No.: 25-3002PCTto determine whether STA 1506 switches from the PCH to the NPCA PCH on detecting an inter-BSS PPDU. In example 1800, based on the third field and / or the fourth field, STA 1504 determines that STA 1506 switches from the PCH to the NPCA PCH on detecting an inter-BSS PPDU on the PCH Similarly, based on the first field and / or the second field, STA 1506 determines that STA 1504 switches from the PCH to the NPCA PCH on detecting an inter-BSS PPDU on the PCH. As such, after detecting inter-BSS PPDU 1816 and switching from the PCH to the NPCA PCH, STA 1506 may transmit a frame 1818 to STA 1504. Frame 1818 may comprise an initial control frame (ICF). Frame 1818 may include information related to the TDLS direct link established between STA 1504 and STA 1506 on the PCH. For example, frame 1818 may indicate a context (frame sequence number, BA number, etc.) related to ongoing communication via the TDLS direct link. As such, frame 1818 may allow the ongoing communication via the TDLS direct link to be seamlessly continued via the NPCA PCH. In an embodiment, frame 1818 may comprise a TDLS Channel Switch Request frame for switching to the TDLS direct link from the PCH to the NPCA PCH.

[0221] STA 1506 may respond to frame 1818 by transmitting a frame 1820 via the NPCA PCH to STA 1504. Frame 1820 may comprise an initial control response (ICR). Subsequently, STA 1506 may transmit a data frame 1822 to STA 1504, and STA 1504 may respond to data frame 1822 by transmitting a BA frame 1824 to STA 1506. At expiration of the NAV set based on inter-BSS PPDU 1816, STAs 1504 and 1506 return to the PCH. STAs 1504 and 1506 may continue communicating via the TDLS direct link established on the PCH.

[0222] FIG. 19 illustrates an example process 1900 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 1504 or STA 1506, for example.

[0223] As shown in FIG. 19, process 1900 may include a step 1902, which includes transmitting, by the first STA to an AP, a first TDLS frame comprising a first field indicating whether the first STA supports NPCA operation. The first STA may be associated with the AP. In an embodiment, the first STA comprises a TDLS initiator STA. In an embodiment, the first field comprises a first NPCA support field. In an embodiment, the first TDLS frame comprises a first capabilities element comprising the first field. In an embodiment, the first capabilities element comprises a first UHR capabilities element. The first UHR capabilities element may comprise a first UHR capabilities information field comprising the first field. In an embodiment, the first TDLS frame comprises a TDLS discovery request frame, a TDLS setup request frame, or a TDLS setup confirm frame.

[0224] In an embodiment, the first TDLS frame comprises a first indication of a second STA. The second STA may be associated with the AP. The second STA may comprise a TDLS responder STA. In an embodiment, the first indication comprises a destination address of the first TDLS frame.Docket No.: 25-3002PCT

[0225] In an embodiment, transmitting the first TDLS frame in step 1902 comprises transmitting a first data frame that encapsulates the first TDLS frame. In an embodiment, the first data frame comprises a first MAC frame comprising the first TDLS frame.

[0226] In an embodiment, the first TDLS frame further comprises a second field indicating whether the first STA enables / activates NPCA operation. In an embodiment, the second field comprises an “NPCA Operation Information Present” field. In an embodiment, the first TDLS frame comprises a capabilities (or operation) element comprising the second field. In an embodiment, the capabilities (or operation) element comprises a UHR capabilities (or UHR operation) element. The UHR capabilities element may comprise a UHR capabilities information field comprising the second field. In an embodiment, the first TDLS frame further comprises one or more first NPCA-related parameters. The one or more first NPCA-related parameters may comprise a first NPCA switching delay, a first NPCA switching back delay, a first NPCA minimum duration threshold, and an NPCA primary channel of the first STA.

[0227] In an embodiment, process 1900 may further comprise determining, by the first STA, whether to switch from a PCH to an NPCA PCH based on the first field.

[0228] In an embodiment, process 1900 may further comprise switching, by the first STA, from the PCH to the NPCA PCH based on the first field. In an embodiment, the first STA supporting NPCA operation comprises the first STA switching from the PCH to the NPCA PCH based on detecting a first inter-BSS PPDU on the PCH.

[0229] In an embodiment, process 1900 may further comprise determining, by the first STA, that a PPDU being received via the PCH comprises the first inter-BSS PPDU. In an embodiment, where the first field indicates that the first STA supports NPCA operation, switching from the PCH to the NPCA PCH based on the first field comprises switching from the PCH to the NPCA PCH based on determining that the PPDU being received via the PCH comprises the first inter-BSS PPDU. In another embodiment, where the first field indicates that the first STA does not support NPCA operation, switching from the PCH to the NPCA PCH based on the first field comprises not switching from the PCH to the NPCA PCH based on determining that the PPDU being received via the PCH comprises the first inter-BSS PPDU.

[0230] In an embodiment, process 1900 may further comprise receiving, by the first STA from the AP, a second TDLS frame comprising a third field indicating whether the second STA supports NPCA operation. The second TDLS frame may comprise a TDLS setup response frame. In an embodiment, the third field comprises a second NPCA support field. In an embodiment, the second TDLS frame comprises a second capabilities element comprising the third field. In an embodiment, the second capabilities element comprises a second UHR capabilities element.

[0231] In an embodiment, the second TDLS frame comprises a second indication of the second STA. In an embodiment, the second indication comprises a source address of the second TDLS frame.Docket No.: 25-3002PCT

[0232] In an embodiment, where the second TDLS frame comprises a TDLS setup response frame, the TDLS setup response frame comprises a status code field indicating establishment status of a TDLS link between the first STA and the second STA.

[0233] In an embodiment, receiving the second TDLS frame comprises receiving a second data frame that encapsulates the second TDLS frame. In an embodiment, the second data frame comprises a second MAC frame comprising the second TDLS frame.

[0234] In an embodiment, the second TDLS frame further comprises a fourth field indicating whether the second STA enables / activates NPCA operation. In an embodiment, the fourth field comprises an “NPCA Operation Information Present” field. In an embodiment, the second TDLS frame comprises a capabilities (or operation) element comprising the fourth field. In an embodiment, the capabilities (or operation) element comprises a UHR capabilities (or UHR operation) element. The UHR capabilities element may comprise a UHR capabilities information field comprising the fourth field. In an embodiment, the second TDLS frame further comprises one or more second NPCA-related parameters. In an embodiment, the one or more second NPCA-related parameters comprise a second NPCA switching delay, a second NPCA switching back delay, a second NPCA minimum duration threshold, and an NPCA primary channel of the second STA.

[0235] In an embodiment, process 1900 may further comprise determining, by the first STA, whether to switch from the PCH to the NPCA PCH based on one or more of the first field and the third field. In an embodiment, process 1900 may further comprise switching, by the first STA, from the PCH to the NPCA PCH based on one or more of the first field and the third field.

[0236] In an embodiment, where the first field indicates that the first STA supports NPCA operation and the third field indicates that the second STA supports NPCA operation, switching from the PCH to the NPCA PCH based on the first field and the third field comprises switching from the PCH to the NPCA PCH based on determining, by the first STA, that a PPDU being received via the PCH comprises the first inter-BSS PPDU. In an embodiment, process 1900 may further comprise transmitting, by the first STA to the AP, a frame indicating enablement / activation of NPCA operation by the first STA. In an embodiment, the frame comprises a reassociation request frame indicating that the first STA supports NPCA operation. In an embodiment, process 1900 may further comprise communicating, by the first STA, with the second STA via the NPCA PCH.

[0237] In another embodiment, where the third field indicates that the second STA does not support NPCA operation, switching from the PCH to the NPCA PCH based on the first field and the third field comprises not switching from the PCH to the NPCA PCH based on the determining, by the first STA, that a PPDU being received via the PCH comprises the first inter-BSS PPDU. In an embodiment, process 1900 may further comprise transmitting, by the first STA to the AP, a frame indicating disablement / deactivation of NPCA operation by the first STA. In an embodiment, the frame comprises a reassociation request frame indicatingDocket No.: 25-3002PCTthat the first STA does not support NPCA operation. In an embodiment, process 1900 may further comprise communicating, by the first STA, with the second STA via the PCH.

[0238] FIG. 20 illustrates another example process 2000 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 a first STA, such as STA 1504 or STA 1506, for example.

[0239] As shown in FIG. 20, process 2000 may include a step 2002, which includes receiving, by the first STA from an AP, a first TDLS frame comprising a first field indicating whether a second STA supports NPCA operation. The first STA may be associated with the AP. The second STA may be associated with the AP. The first TDLS frame may comprise a TDLS setup response frame. In an embodiment, the first field comprises a first NPCA support field. In an embodiment, the first TDLS frame comprises a first capabilities element comprising the first field. In an embodiment, the first capabilities element comprises a first UHR capabilities element. The first UHR capabilities element may comprise a first UHR capabilities information field comprising the first field. In an embodiment, the first TDLS frame comprises a first indication of the second STA. In an embodiment, the first indication comprises a source address of the first TDLS frame.

[0240] In an embodiment, process 2000 may further comprise transmitting, by the first STA to the AP, a second TDLS frame comprising a second field indicating whether the first STA supports NPCA operation. In an embodiment, the second field comprises a second NPCA support field. In an embodiment, the second TDLS frame comprises a second capabilities element comprising the second field. In an embodiment, the second capabilities element comprises a second UHR capabilities element. The second UHR capabilities element may comprise a second UHR capabilities information field comprising the second field. In an embodiment, the first TDLS frame comprises a TDLS discovery request frame, a TDLS setup request frame, or a TDLS setup confirm frame. In an embodiment, the second TDLS frame comprises a second indication of the second STA. In an embodiment, the second indication comprises a destination address of the second TDLS frame.

[0241] FIG. 21 illustrates another example process 2100 according to an embodiment. Example process 2100 is provided for the purpose of illustration only and is not limiting of embodiments. Example process 2100 may be performed by an AP, such as AP 1502, for example.

[0242] As shown in FIG. 21, process 2100 may include a step 2102, which includes receiving, by the AP from a first STA, a first TDLS frame comprising a first field indicating whether the first STA supports NPCA operation. In an embodiment, the first STA supporting NPCA operation comprises the first STA switching from the PCH to the NPCA PCH based on detecting a first inter-BSS PPDU on the PCH. The first STA may be associated with the AP. In an embodiment, the first STA comprises a TDLS initiator STA. In an embodiment, the first field comprises a first NPCA support field. In an embodiment, the first TDLS frame comprises a first capabilities element comprising the first field . In an embodiment, the first capabilities element comprises a first UHR capabilities element. The first UHR capabilities element may comprise a first UHRDocket No.: 25-3002PCTcapabilities information field comprising the first field. In an embodiment, the first TDLS frame comprises a TDLS discovery request frame, a TDLS setup request frame, or a TDLS setup confirm frame.

[0243] In an embodiment, the first TDLS frame comprises a first indication of a second STA. The second STA may be associated with the AP. The second STA may comprise a TDLS responder STA. In an embodiment, the first indication comprises a destination address of the first TDLS frame.

[0244] In an embodiment, receiving the first TDLS frame in step 2102 comprises receiving a first data frame that encapsulates the first TDLS frame. In an embodiment, the first data frame comprises a first MAC frame comprising the first TDLS frame.

[0245] In an embodiment, the first TDLS frame further comprises a second field indicating whether the first STA enables / activates NPCA operation. In an embodiment, the second field comprises an “NPCA Operation Information Present” field. In an embodiment, the first TDLS frame comprises a capabilities (or operation) element comprising the second field. In an embodiment, the capabilities (or operation) element comprises a UHR capabilities (or UHR operation) element. The UHR capabilities element may comprise a UHR capabilities information field comprising the second field. In an embodiment, the first TDLS frame further comprises one or more first NPCA-related parameters. The one or more first NPCA-related parameters may comprise a first NPCA switching delay, a first NPCA switching back delay, a first NPCA minimum duration threshold, and an NPCA primary channel of the first STA.

[0246] In an embodiment, process 2100 may further comprise transmitting, by the AP to the first STA, a second TDLS frame comprising a third field indicating whether the second STA supports NPCA operation. The second TDLS frame may comprise a TDLS setup response frame. In an embodiment, the third field comprises a second NPCA support field. In an embodiment, the second TDLS frame comprises a second capabilities element comprising the third field. In an embodiment, the second capabilities element comprises a second UHR capabilities element.

[0247] In an embodiment, the second TDLS frame comprises a second indication of the second STA. In an embodiment, the second indication comprises a source address of the second TDLS frame.

[0248] In an embodiment, where the second TDLS frame comprises a TDLS setup response frame, the TDLS setup response frame comprises a status code field indicating establishment status of a TDLS link between the first STA and the second STA.

[0249] In an embodiment, transmitting the second TDLS frame comprises transmitting a second data frame that encapsulates the second TDLS frame. In an embodiment, the second data frame comprises a second MAC frame comprising the second TDLS frame.

[0250] In an embodiment, the second TDLS frame further comprises a fourth field indicating whether the second STA enables / activates NPCA operation. In an embodiment, the fourth field comprises an “NPCA Operation Information Present” field. In an embodiment, the second TDLS frame comprises a capabilities (or operation) element comprising the fourth field. In an embodiment, the capabilities (or operation) elementDocket No.: 25-3002PCTcomprises a UHR capabilities (or UHR operation) element. The UHR capabilities element may comprise a UHR capabilities information field comprising the fourth field. In an embodiment, the second TDLS frame further comprises one or more second NPCA-related parameters. In an embodiment, the one or more second NPCA-related parameters comprise a second NPCA switching delay, a second NPCA switching back delay, a second NPCA minimum duration threshold, and an NPCA primary channel of the second STA.

[0251] In an embodiment, where the first field indicates that the first STA supports NPCA operation and the third field indicates that the second STA supports NPCA operation, process 2100 may further comprise receiving, by the AP from the first STA, a frame indicating enablement / activation of NPCA operation by the first STA. In an embodiment, the frame comprises a reassociation request frame indicating that the first STA supports NPCA operation. In another embodiment, where the third field indicates that the second STA does not support NPCA operation, process 2100 may further comprise receiving, by the AP from the first STA, a frame indicating disablement / deactivation of NPCA operation by the first STA. In an embodiment, the frame comprises a reassociation request frame indicating that the first STA does not support NPCA operation.

[0252] FIG. 22 illustrates another example process 2200 according to an embodiment, Example process 2200 is provided for the purpose of illustration only and is not limiting of embodiments. Example process 2200 may be performed by an AP, such as AP 1502, for example.

[0253] As shown in FIG. 22, process 2000 may include a step 2202, which includes transmitting, by an AP to a first STA, a first TDLS frame comprising a first field indicating whether a second STA supports NPCA operation. The first STA may be associated with the AP. The second STA may be associated with the AP. The first TDLS frame may comprise a TDLS setup response frame. In an embodiment, the first field comprises a first NPCA support field. In an embodiment, the first TDLS frame comprises a first capabilities element comprising the first field. In an embodiment, the first capabilities element comprises a first UHR capabilities element. The first UHR capabilities element may comprise a first UHR capabilities information field comprising the first field. In an embodiment, the first TDLS frame comprises a first indication of the second STA. In an embodiment, the first indication comprises a source address of the first TDLS frame.

[0254] In an embodiment, process 2200 may further comprise receiving, by the AP from the first STA, a second TDLS frame comprising a second field indicating whether the first STA supports NPCA operation. In an embodiment, the second field comprises a second NPCA support field. In an embodiment, the second TDLS frame comprises a second capabilities element comprising the second field. In an embodiment, the second capabilities element comprises a second UHR capabilities element. The second UHR capabilities element may comprise a second UHR capabilities information field comprising the second field. In an embodiment, the first TDLS frame comprises a TDLS discovery request frame, a TDLS setup request frame, or a TDLS setup confirm frame. In an embodiment, the second TDLS frame comprises a second indication of the second STA. In an embodiment, the second indication comprises a destination address of the second TDLS frame.Docket No.: 25-3002PCT

[0255] As would be understood by a person of skill in the art based on the teachings herein, embodiments are not limited to signaling NPCA-related information via TDLS frames and may be extended to signaling / including other types of capability / support / enablement / activation information (e.g., dynamic power saving (DPS) support / enablement, dynamic subchannel operation (DSO) support / enablement, etc.) in TDLS frames. The signaling of such information via TDLS frames allows for the information to be communicated with reduced overhead during TDLS negotiation / setup. A STA receiving such capability / support / enablement / activation information regarding another STA may use the information to determine whether to establish a TDLS direct link with the other STA. Additionally, the STA may be configured to adapt its operation based on this information, after the TDLS direct link is established with the other STA.

[0256] FIG. 23 illustrates another example process 2300 according to an embodiment. Example process 2300 is provided for the purpose of illustration only and is not limiting of embodiments. Example process 2300 may be performed by a first STA, such as STA 1504 or STA 1506, for example.

[0257] As shown in FIG. 23, process 2300 may include a step 2302, which includes transmitting, by the first STA to an AP, a first TDLS frame comprising a first UHR capabilities element indicating a capability of the first STA. The first STA may be associated with the AP. In an embodiment, the first STA comprises a TDLS initiator STA. In an embodiment, the first UHR capabilities element may comprise a first UHR capabilities information field indicating the capability of the first STA. In an embodiment, the first TDLS frame comprises a TDLS discovery request frame, a TDLS setup request frame, or a TDLS setup confirm frame.

[0258] In an embodiment, the first TDLS frame comprises a first indication of a second STA. The second STA may be associated with the AP. The second STA may comprise a TDLS responder STA. In an embodiment, the first indication comprises a destination address of the first TDLS frame.

[0259] In an embodiment, process 2300 may further comprising receiving, by the first STA from the AP, a second TDLS frame comprising a second UHR capabilities element indicating a capability of the second STA. In an embodiment, the second UHR capabilities element may comprise a second UHR capabilities information field indicating the capability of the second STA. In an embodiment, the second TDLS frame comprises a TDLS setup response frame.

[0260] FIG. 24 illustrates another example process 2400 according to an embodiment. Example process 2400 is provided for the purpose of illustration only and is not limiting of embodiments. Example process 2400 may be performed by a first STA, such as STA 1504 or STA 1506, for example.

[0261] As shown in FIG 24, process 2400 may include a step 2402, which includes receiving, by the first STA from an AP, a first TDLS frame comprising a first UHR capabilities element indicating a capability of a second STA. The first STA may be associated with the AP. The second STA may be associated with the AP. In an embodiment, the first STA comprises a TDLS initiator STA. In an embodiment, the second STA comprises a TDLS responder STA. In an embodiment, the first UHR capabilities element may comprise aDocket No.: 25-3002PCTfirst UHR capabilities information field indicating the capability of the second STA. In an embodiment, the first TDLS frame comprises a TDLS setup response frame.

[0262] In an embodiment, the first TDLS frame comprises a first indication of the second STA. In an embodiment, the first indication comprises a source address of the first TDLS frame.

[0263] In an embodiment, process 2400 may further comprising transmitting, by the first STA to the AP, a second TDLS frame comprising a second UHR capabilities element indicating a capability of the first STA. In an embodiment, the second UHR capabilities element may comprise a second UHR capabilities information field indicating the capability of the first STA. In an embodiment, the second TDLS frame comprises a TDLS discovery request frame, a TDLS setup request frame, or a TDLS setup confirm frame.

[0264] FIG. 25 illustrates another example process 2500 according to an embodiment. Example process 2500 is provided for the purpose of illustration only and is not limiting of embodiments. Example process 2500 may be performed by an AP, such as AP 1502, for example.

[0265] As shown in FIG. 25, process 2500 may include a step 2502, which includes receiving, by the AP from a first STA, a first TDLS frame comprising a first UHR capabilities element indicating a capability of the first STA. The first STA may be associated with the AP. In an embodiment, the first STA comprises a TDLS initiator STA. In an embodiment, the first UHR capabilities element may comprise a first UHR capabilities information field indicating the capability of the first STA. In an embodiment, the first TDLS frame comprises a TDLS discovery request frame, a TDLS setup request frame, or a TDLS setup confirm frame.

[0266] In an embodiment, the first TDLS frame comprises a first indication of a second STA. The second STA may be associated with the AP. The second STA may comprise a TDLS responder STA. In an embodiment, the first indication comprises a destination address of the first TDLS frame.

[0267] In an embodiment, process 2500 may further comprising transmitting, by the AP to the first STA, a second TDLS frame comprising a second UHR capabilities element indicating a capability of the second STA. In an embodiment, the second UHR capabilities element may comprise a second UHR capabilities information field indicating the capability of the second STA. In an embodiment, the second TDLS frame comprises a TDLS setup response frame.

[0268] FIG. 26 illustrates another example process 2600 according to an embodiment. Example process 2600 is provided for the purpose of illustration only and is not limiting of embodiments. Example process 2600 may be performed by an AP, such as AP 1502, for example.

[0269] As shown in FIG. 26, process 2600 may include a step 2602, which includes transmitting, by the AP to a first STA, a first TDLS frame comprising a first UHR capabilities element indicating a capability of a second STA. The first STA may be associated with the AP. The second STA may be associated with the AP. In an embodiment, the first STA comprises a TDLS initiator STA. In an embodiment, the second STA comprises a TDLS responder STA. In an embodiment, the first UHR capabilities element may comprise aDocket No.: 25-3002PCTfirst UHR capabilities information field indicating the capability of the second STA. In an embodiment, the first TDLS frame comprises a TDLS setup response frame.

[0270] In an embodiment, the first TDLS frame comprises a first indication of the second STA. In an embodiment, the first indication comprises a source address of the first TDLS frame.

[0271] In an embodiment, process 2600 may further comprising receiving, by the AP from the first STA, a second TDLS frame comprising a second UHR capabilities element indicating a capability of the first STA. In an embodiment, the second UHR capabilities element may comprise a second UHR capabilities information field indicating the capability of the first STA. In an embodiment, the second TDLS frame comprises a TDLS discovery request frame, a TDLS setup request frame, or a TDLS setup confirm frame.

[0272] 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. 15-26 may switch to the NPCA primary channel for NPCA operation if either condition 1) or 2), described below, is met.

[0273] 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.

[0274] In an implementation, an NPCA AP that has an operating bandwidth less than 80 MHz does not enable NPCA operation. In an implementation, an AP of a multiple BSSID set that enables NPCA operation may indicate the same NPCA primary channel, same NPCA minimum duration, same NPCA switching delay, and same NPCA switch back delay as all of the other APs of the same multiple BSSID set that have enabled NPCA operation. In an implementation, an AP of a co-hosted BSS that enables NPCA operation may indicate the same NPCA primary channel, same NPCA minimum duration, same NPCA switching delay, and same NPCA switch back delay as all of the other APs of the same co-hosted BSSs that have enabled NPCA operation.

[0275] 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.

[0276] 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 toDocket No.: 25-3002PCT1 in Management frames it transmits before enabling NPCA operation in its BSS and while NPCA operation remains enabled.

[0277] 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.

[0278] 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 O.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.

[0279] In an implementation, an NPCA AP may indicate a value in the NPCA Primary Channel field, of transmitted NPCA Operation Parameters fields, that corresponds to a channel that is located within the secondary 40 MHz of the BSS operating channel if the BSS is an 80 MHz BSS, that corresponds to a channel that is located within the secondary 80 MHz of the BSS operating channel if the BSS is a 160 MHz BSS, and that corresponds to a channel that is located within the secondary 160 MHz of the BSS operating channel if the BSS is a 320 MHz BSS.

[0280] 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.Docket No.: 25-3002PCT

[0281] 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,PCA switch back delay.

[0282] 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.

[0283] 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.

[0284] 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.

[0285] 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:i) 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.Docket No.: 25-3002PCTd) 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 of the sequence of PPDUs is greater than the value indicated in the most recently received or transmitted NPCA Minimum Duration Threshold field corresponding to its BSS.ii) If the NPCA AP corresponding to the BSS of which the STA is a member has enabled MOPLEN NPCA in addition to PHYLEN NPCA and the value of the MAC variable NPCA_CFRAME_TXOP_REM_DUR derived from 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.Docket No.: 25-3002PCTf) 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.

[0286] 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.

[0287] 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.

[0288] In an implementation, the MAC variable NPCA_PHY_TXOP_REM_DUR derived from a received PPDU is:Set to 0, if the RXVECTOR parameter TXOP_DURATION is UNSPECIFIED, or if the NPCA AP corresponding to the BSS of which the STA is a member has not enabled MOPLEN NPCA.Otherwise, it is equal to the value in usee, of the remaining duration of the PPDU, determined by the MAC at the time of the receipt of the PHY-RXSTART. indication primitive associated with the received PPDU, by subtracting the time elapsed between the reception of the PHY-CCA.indication(BUSY) and PHY-RXSTART. indication primitives associated with the received PPDU from the value of RXTIME corresponding to the received PPDU, plus the value of the TXOP_DURATION parameter of the RXVECTOR of the PPDU.

[0289] In an implementation, the MAC variable NPCA_CFRAME_TXOP_REM_DUR derived from a received PPDU is:Set to 0, if the NPCA AP corresponding to the BSS of which the STA is a member has not enabled MOPLEN NPCA.Otherwise, it is set to the value in the Duration / ID field of the initial Control frame in the received PPDU at the receipt of the PHY-RXEND. indication primitive of the PPDU that contained the frame. The value of NPCA_CFRAME_TXOP_REM_DUR is reduced by the amount of time elapsed between the PHY-RXEND.indication primitive of the initial Control frame from which the value of NPCA_CFRAME_TXOP_REM_DUR was determined and the PHY-RXSTART. indication primitive of the thirdDocket No.: 25-3002PCTPPDU 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.

[0290] 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 0, set NPCA_TIMER to the largest non-zero value of the variables NPCA_PPDU_REM_DUR, NPCA_PHY_TXOP_REM_DUR and NPCA_CFRAME_TXOP_REM_DUR, minus the switch back delay that the STA indicated in the most recently transmitted NPCA Operation Parameters field.ii) Store the existing values of the variables QSRC[AC], CW[AC] and the backoff counter for each EDCAF.ill) Set QSRC[AC] for each AC to the value of the Initial NPCA QSRC field of the NPCA Operation Parameters received from its associated NPCA AP.iv) initialize variables 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.Docket No.: 25-3002PCT5) 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 leastoneofthe 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.d) 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.Docket No.: 25-3002PCT12) 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

[0291] 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.

[0292] 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

1. Docket No.: 25-3002PCTCLAIMSWhat is claimed is:

1. A method comprising:transmitting, by a first station (STA) to an access point (AP), a tunneled direct link setup (TDLS) setup request frame comprising:a destination address indicating a second STA; anda first field indicating that the first STA supports NPCA operation;receiving, by the first STA from the AP, a TDLS setup response frame comprising:a source address indicating the second STA;a second field indicating that the second STA does not support NPCA operation; and a status code field set to a value indicating successful establishment of a TDLS link between the first STA and the second STA; andbased on the second field indicating that the second STA does not support NPCA operation, transmitting, by the first STA to the AP, a frame indicating that the first STA disables NPCA operation.

2. A method comprising:transmitting, by a first station (STA) to an access point (AP), a first tunneled direct link setup (TDLS) frame comprising:a first indication of a second STA; anda first field indicating whether the first STA supports non-primary channel access (NPCA) operation.

3. The method of claim 2, wherein the first STA comprises a TDLS initiator STA.

4. The method of any of claims 2-3, wherein the first TDLS frame comprises a TDLS discovery request frame or a TDLS setup request frame.

5. The method of any of claims 2-4, wherein transmitting the first TDLS frame comprises transmitting a first data frame that encapsulates the first TDLS frame.

6. The method of claim 5, wherein the first data frame comprises a first medium access control (MAC) frame comprising the first TDLS frame.

7. The method of any of claims 2-6, wherein the first indication comprises a destination address of the first TDLS frame.

8. The method of any of claims 2-7, wherein the second STA comprises a TDLS responder STA.

9. The method of any of claims 2-8, wherein the first field comprises a first “NPCA supported” field 10. The method of any of claims 2-9, wherein the first TDLS frame comprises a first capabilities element comprising the first field.

11. The method of claim 10, wherein the first capabilities element comprises a first ultra-high reliability (UHR) capabilities element.Docket No.: 25-3002PCT12. The method of any of claims 2-11 , wherein the first TDLS frame further comprises a second field indicating whether the first STAenables / activates NPCA operation.

13. The method of any of claims 2-12, wherein the first TDLS frame further comprises one or more first NPCA-related parameters.

14. The method of claim 13, wherein the one or more first NPCA-related parameters comprise a first NPCA switching delay, a first NPCA switching back delay, a first NPCA minimum duration threshold, and an NPCA primary channel of the first STA.

15. The method of any of claims 2-14, further comprising determining, by the first STA, whether to switch from a primary channel (PCH) to an NPCA PCH based on the first field.

16. The method of any of claims 2-15, further comprising switching, by the first STA, from a primary channel (PCH) to an NPCA PCH based on the first field.

17. The method of claim 16, wherein the first STA supporting NPCA operation comprises the first STA switching 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.

18. The method of claim 17, further comprising determining, by the first STA, that a PPDU being received via the PCH comprises the first inter-BSS PPDU.

19. The method of claim 18, wherein the first field indicates that the first STA supports NPCA operation, and wherein switching from the PCH to the NPCA PCH based on the first field comprises switching from the PCH to the NPCA PCH based on the determining.

20. The method of claim 18, wherein the first field indicates that the first STA does not support NPCA operation, and wherein switching from the PCH to the NPCA PCH based on the first field comprises not switching from the PCH to the NPCA PCH based on the determining.

21. The method of any of claims 2-20, wherein the first STA is associated with the AR22. The method of any of claims 2-21 , further comprising receiving, by the first STA from the AP, a second TDLS frame comprising:a second indication of the second STA; anda third field indicating whether the second STA supports NPCA operation.

23. The method of claim 22, wherein the second TDLS frame comprises a TDLS setup response frame.

24. The method of claim 23, wherein the TDLS setup response frame comprises a status code field indicating establishment status of a TDLS link between the first STA and the second STA.

25. The method of any of claims 22-24, wherein receiving the second TDLS frame comprises receiving a second data frame that encapsulates the second TDLS frame.

26. The method of claim 25, wherein the second data frame comprises a second MAC frame comprising the second TDLS frame.Docket No.: 25-3002PCT27. The method of any of claims 22-26, wherein the second indication comprises a source address of the second TDLS frame.

28. The method of any of claims 22-27, wherein the third field comprises a second "NPCA supported” field.

29. The method of any of claims 22-28, wherein the second TDLS frame comprises a second capabilities element comprising the third field.

30. The method of claim 29, wherein the second capabilities element comprises a second ultra-high reliability (UHR) capabilities element.

31. The method of any of claims 22-30, wherein the second TDLS frame further comprises a fourth field indicating whether the second STA enables / activates NPCA operation.

32. The method of any of claims 22-31 , wherein the second TDLS frame further comprises one or more second NPCA-related parameters.

33. The method of claim 32, wherein the one or more second NPCA-related parameters comprise a second NPCA switching delay, a second NPCA switching back delay, a second NPCA minimum duration threshold, and an NPCA primary channel of the second STA.

34. The method of any of claims 15-16, further comprising receiving, by the first STA from the AP, a second TDLS frame comprising:a second indication of the second STA; anda third field indicating whether the second STA supports NPCA operation.

35. The method of claim 34, further comprising determining, by the first STA, whether to switch from the PCH to the NPCA PCH based on one or more of the first field and the third field.

36. The method of claim 34, further comprising switching, by the first STA, from the PCH to the NPCA PCH based on one or more of the first field and the third field.

37. The method of claim 36, wherein the first STA supporting NPCA operation comprises the first STA switching 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.

38. The method of claim 37, further comprising determining, by the first STA, that a PPDU being received via the PCH comprises the first inter-BSS PPDU.

39. The method of claim 38, wherein the first field indicates that the first STA supports NPCA operation and the third field indicates that the second STA supports NPCA operation, and wherein switching from the PCH to the NPCA PCH based on the first field and the third field comprises switching from the PCH to the NPCA PCH based on the determining.

40. The method of claim 39, further comprising transmitting, by the first STA to the AP, a frame indicating enablement / activation of NPCA operation by the first STA.Docket No.: 25-3002PCT41. The method of claim 40, wherein the frame comprises a reassociation request frame indicating that the first STA supports NPCA operation.

42. The method of any of claims 39-41 , further comprising communicating, by the first STA, with the second STA via the NPCA PCH.

43. The method of claim 38, wherein the third field indicates that the second STA does not support NPCA operation, and wherein switching from the PCH to the NPCA PCH based on the first field and the third field comprises not switching from the PCH to the NPCA PCH based on the determining.

44. The method of claim 43, further comprising transmitting, by the first STA to the AP, a frame indicating disablement / deactivation of NPCA operation by the first STA.

45. The method of claim 44, wherein the frame comprises a reassociation request frame indicating that the first STA does not support NPCA operation.

46. The method of any of claims 43-45, further comprising communicating, by the first STA, with the second STA via the PCH.

47. The method of any of claims 2-46, wherein the second STA is associated with the AP.

48. 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 1-47.

49. 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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