Non-primary channel access (NPCA) switching operation for direct communication

Abstract

A first station (STA) receives from an access point (AP) a first frame indicating an identifier (ID) of a second STA, where the second STA has a peer-to-peer (PTP) link with a third STA. The first STA determines that: a physical layer protocol data unit (PPDU) being received via a primary channel (PCH) comprises an intra-basic service set (intra-BSS) downlink (DL); and a STA ID field of the PPDU indicates the second ID. Based on the determination, the first STA switches from the PCH to a non-primary channel access (NPCA) PCH.

Description

Docket No.: 24-3056PCTTITLENON-PRIMARY CHANNEL ACCESS (NPCA) SWITCHING OPERATION FOR DIRECT COMMUNICATIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 717,934, filed November 8, 2024, and U.S. Provisional Application No. 63 / 729,543, filed December 9, 2024, all of which are hereby incorporated by reference in their entireties.BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

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

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

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

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

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

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

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

[0014] FIG. 12 illustrates an inefficiency that may arise in the NPCA operation of FIG. 11 .

[0015] FIG. 13 shows an example that illustrates an example NPCA operation.

[0016] FIG. 14 shows an example that illustrates another example NPCA operation.

[0017] FIG. 15 shows an example that illustrates an example NPCA operation according to an embodiment.

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

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

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

[0021] FIG. 19 illustrates another example process according to an embodiment.DETAILED DESCRIPTIONDocket No.: 24-3056PCT

[0022] In the present disclosure, various embodiments are presented as examples of how the disclosed techniques may be implemented and / or how the disclosed techniques may be practiced in environments and scenarios. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope. After reading the description, it will be apparent to one skilled in the relevant art how to implement alternative embodiments. The present embodiments may not be limited by any of the described exemplary embodiments. The embodiments of the present disclosure will be described with reference to the accompanying drawings. Limitations, features, and / or elements from the disclosed example embodiments may be combined to create further embodiments within the scope of the disclosure. Any figures which highlight the functionality and advantages are presented for example purposes only. The disclosed architecture is sufficiently flexible and configurable, such that it may be utilized in ways other than those shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments.

[0023] Embodiments may be configured to operate as needed. The disclosed mechanism may be performed when certain criteria are met, for example, in a station, an access point, a radio environment, a network, a combination of the above, and / or the like. Example criteria may be based, at least in part, on for example, wireless device or network node configurations, traffic load, initial system set up, packet sizes, traffic characteristics, a combination of the above, and / or the like. When the one or more criteria are met, various example embodiments may be applied. Therefore, it may be possible to implement example embodiments that selectively implement disclosed protocols.

[0024] In this disclosure, “a” and “an" and similar phrases are to be interpreted as “at least one” and “one or more.” Similarly, any term that ends with the suffix “(s)” is to be interpreted as “at least one” and “one or more." In this disclosure, the term “may” is to be interpreted as “may, for example.” In other words, the term “may” is indicative that the phrase following the term “may" is an example of one of a multitude of suitable possibilities that may, or may not, be employed by one or more of the various embodiments. The terms “comprises” and “consists of', as used herein, enumerate one or more components of the element being described. The term “comprises” is interchangeable with “includes" and does not exclude unenumerated components from being included in the element being described. By contrast, “consists of' provides a complete enumeration of the one or more components of the element being described. The term “based on”, as used herein, may be interpreted as “based at least in part on” rather than, for example, “based solely on”. The term “and / or” as used herein represents any possible combination of enumerated elements. For example, “A, B, and / or C” may represent A; B; C; A and B; A and C; B and C; or A, B, and C.

[0025] If A and B are sets and every element of A is an element of B, A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B = {STA1 , STA2} are: {STA1}, {STA2}, and {STA1 , STA2}. The phrase “based on” (or equally “based at least on”) is indicative that the phrase following the term “based on” is an example of one of a multitude of suitableDocket No.: 24-3056PCT possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase "in response to" (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “depending on” (or equally “depending at least to”) is indicative that the phrase following the phrase “depending on" is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “employing / using” (or equally “employing / using at least”) is indicative that the phrase following the phrase “employing / using” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments.

[0026] The term configured may relate to the capacity of a device whether the device is in an operational or non-operational state. Configured may refer to specific settings in a device that effect the operational characteristics of the device whether the device is in an operational or non-operational state. In other words, the hardware, software, firmware, registers, memory values, and / or the like may be “configured” within a device, whether the device is in an operational or nonoperational state, to provide the device with specific characteristics. Terms such as “a control message to cause in a device" may mean that a control message has parameters that may be used to configure specific characteristics or may be used to implement certain actions in the device, whether the device is in an operational or non-operational state.

[0027] In this disclosure, parameters (or equally called, fields, or Information elements: lEs) may comprise one or more information objects, and an information object may comprise one or more other objects. For example, if parameter (IE) N comprises parameter (IE) M, and parameter (IE) M comprises parameter (IE) K, and parameter (IE) K comprises parameter (information element) J. Then, for example, N comprises K, and N comprises J. In an example embodiment, when one or more messages / frames comprise a plurality of parameters, it implies that a parameter in the plurality of parameters is in at least one of the one or more messages / frames but does not have to be in each of the one or more messages / frames.

[0028] Many features presented are described as being optional through the use of “may” or the use of parentheses. For the sake of brevity and legibility, the present disclosure does not explicitly recite each and every permutation that may be obtained by choosing from the set of optional features. The present disclosure is to be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features may be embodied in seven ways, namely with just one of the three possible features, with any two of the three possible features or with three of the three possible features

[0029] Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g., hardware with a biological element) or a combination thereof, which may be behaviorally equivalent. For example, modules may be implemented as a softwareDocket No.: 24-3056PCT 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.

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

[0031] 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.

[0032] 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 1 10-2 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.

[0033] 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).

[0034] 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.

[0035] 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).

[0036] For example, in FIG. 1 , STAs 106-4, 106-5, and 106-6 may be configured to form a first IBSS 112- 1. Similarly, STAs 106-7 and 106-8 may be configured to form a second IBSS 112-2. Since an IBSS doesDocket No.: 24-3056PCT 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.

[0037] 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.

[0038] 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.

[0039] A frequency band may include one or more sub-bands or frequency channels For example, PPDUs conforming to the IEEE 802.11 n, 802.1 1ac, 802.11 ax and / or 802.11 be standard amendments may be transmitted over the 2.4 GHz, 5 GHz, and / or 6 GHz bands, each of which may be divided into multiple 20 MHz channels. The PPDUs may be transmitted over a physical channel having a minimum bandwidth of 20 MHz. Larger channels may be optionally formed through channel bonding of a primary 20 MHz channel and one or more 20 MHz secondary channels. For example, PPDUs may be transmitted over physical channels having bandwidths of 40 MHz, 80 MHz, 160 MHz, or 320 MHz by bonding together a primary 20 MHz channel and 1 , 3, 7, or 15 secondary channel respectively. The primary channel is a common channel operation for all STAs where management frames are sent by the AP to ensure that all STAs (regardless of channel bonding support) can receive.

[0040] FIG. 2 is a block diagram illustrating example implementations of a STA 210 and an AP 260. As shown in FIG. 2, STA 210 may include at least one processor 220, a memory 230, and at least one transceiver 240. AP 260 may include at least one processor 270, a memory 280, and at least one transceiver 290. Processor 220 / 270 may be operatively connected to memory 230 / 280 and / or to transceiver 240 / 290.Docket No.: 24-3056PCT

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] As shown in FIG. 3, a MAC frame includes a MAC header, a variable length frame body, and a frame check sequence (FCS).

[0046] 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.

[0047] 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.

[0048] The protocol version subfield is invariant in size and placement across all revisions of the IEEE 802.1 1 standard. The value of the protocol version subfield is 0 for MAC frames.

[0049] The type and subtype subfields together identify the function of the MAC frame. There are three frame types: control, data, and management. Each of the frame types has several defined subtypes. BitsDocket No.: 24-3056PCT 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] The power management subfield is used to indicate the power management mode of a STA.

[0054] 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.

[0055] The protected frame subfield is set to 1 if the frame body field contains information that has been processed by a cryptographic encapsulation algorithm.

[0056] The +HTC subfield indicates that the MAC frame contains an HT control field.

[0057] The duration / ID field of the MAC header indicates various contents depending on the frame type and subtype and the QoS capabilities of the sending STA. For example, in control frames of the power save poll (PS-Poll) subtype, the duration / ID field carries an association identifier (AID) of the STA that transmitted the frame in the 14 least significant bits (LSB), with the 2 most significant bits (MSB) set to 1 . In other frames sent by STAs, the duration / ID field contains a duration value (in microseconds) which is used by a recipient to update a network allocation vector (NAV). The NAV is a counter that indicates to a STA an amount of time during which the STA must defer from accessing the shared medium.

[0058] 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,Docket No.: 24-3056PCT 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.

[0059] 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

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] FIG. 4 illustrates an example trigger frame 400. Trigger frame 400 may correspond to a basic trigger frame as defined in the existing IEEE 802.1 1 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.

[0065] 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.

[0066] 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.

[0067] The Duration field indicates various contents depending on frame type and subtype and the QoS capabilities of the sending STA. For example, in control frames of the power save poll (PS-Poll) subtype, theDocket No.: 24-3056PCTDuration 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).

[0068] 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.

[0069] 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.

[0070] 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.

[0071] The Padding field is optionally present in trigger frame 400 to extend the frame length to give recipient STAs enough time to prepare a response for transmission one SIPS (short interframe spacing) after the frame is received. The Padding field, if present, is at least two octets in length and is set to all 1 s.

[0072] 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.

[0073] FIG. 5 illustrates an example multi-user request to send (MU-RTS) trigger frame 500. MU-RTS trigger frame 500 may be used by an AP to solicit simultaneous CTS frames from multiple STAs to transmit a downlink (DL) MU PPDU to the multiple STAs. As shown in FIG. 5, MU-RTS trigger frame 500 may comprise a frame control field, a duration field, an RA field, a TA field, a common info field, one or more user info fields, a padding field, and an FCS field. The frame control, TA, RA, padding, and FCS fields may be similar to the corresponding fields of trigger frame 400 described above. The common info field may have a format as illustrated by common info field 600 described further below. The duration field may be set to the time, in microseconds, required to transmit the DL MU PPDU, plus the time required to transmit one CTS frame, one ACK frame (if required), and three SIFS periods.Docket No.: 24-3056PCT

[0074] 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.

[0075] 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”).

[0076] 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 802.1 1 standard draft “IEEE P802.1 1-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.

[0077] In an example, STA 702 may transmit an RTS frame 706 to STA 704. STA 702 may transmit RTS frame 706 to protect from hidden STA(s) the transmission of a data frame 710 that STA 702 intends to transmit. RTS frame 706 may include a Duration / ID field. The Duration / ID field may be set to the time, in microseconds, required to transmit data frame 710, plus one CTS frame, plus one ACK frame (if required), plus three SIFS (Short Interframe Spacing) periods.

[0078] In an example, STA 704 may respond to RTS frame 706 by transmitting a CTS frame 708 to STA 702. CTS frame 708 may be transmitted one SIFS period after RTS frame 706. STA 704 may respond toDocket No.: 24-3056PCTRTS frame 706 when RTS frame 706 is addressed to STA 704 and after considering the NAV, unless the NAV was set by a frame originating from STA 702. STA 704 may respond to the RTS frame 706 when RTS frame 706 is addressed to STA 704 and if the NAV indicates idle. For a non-S1 G STA, the NAV indicates idle when the NAV count is 0 or when the NAV count is non-zero but a nonbandwidth signaling TA obtained from a TA field of RTS frame 706 matches a saved TXOP holder address. For an S1 G 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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 802.1 1 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).

[0083] 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.

[0084] As shown in FIG. 8, to protect the transmission of DL MU PPDU 814 to STAs 804 and 806 from interference by OBSS STAs hidden from AP 802, AP 802 may use the MU-RTS / CTS procedure to initiate a TXOP and to protect the TXOP frame exchange sequence. AP 802 may initiate the TXOP by transmitting an MU-RTS trigger frame 808 that solicits simultaneous CTS frame transmissions from STAs 804 and 806.Docket No.: 24-3056PCT

[0085] MU-RTS trigger frame 808 may have a format as illustrated by MU-RTS trigger frame 500 illustrated in FIG. 5. As such, MU-RTS trigger frame 808 may comprise a frame control field, a duration field, an RA field, a TA field, a common info field, one or more user info fields, a padding field, and an FCS field The duration field may be set to the time, in microseconds, required to transmit DL MU PPDU 814, plus the time required to transmit one CTS frame, one ACK frame (if required), and three SIFS periods.

[0086] 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.

[0087] 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.

[0088] After transmitting MU-RTS trigger frame 808, AP 802 may wait for a CTSTimeout interval of aSIFSTime + aSlotTime + aRxPHYStartDelay that begins when a MAC layer of AP 802 receives a PHYTXEND confirm primitive for transmitted MU-RTS trigger frame 808 If the MAC layer does not receive a PHY-RXEARLYSIG. indication or a PHY-RXSTART. indication primitive during the CTSTimeout interval, AP 802 may conclude that the transmission of MU-RTS trigger frame 808 has failed, and, if MU-RTS trigger frame 808 initiated a TXOP, AP 802 may invoke its backoff procedure. If the MAC layer receives a PHY- RXEARLYSIG. indication or a PHY-RXSTART. indication primitive during the CTSTimeout interval, then the MAC layer may wait for the corresponding PHY-RXEND. indication primitive to determine whether transmission of MU-RTS trigger frame 808 was successful. The receipt of a CTS frame from any non-AP STA addressed by MU-RTS trigger frame 808 before the PHY-RXEND. indication primitive shall be interpreted as the successful transmission of MU-RTS trigger frame 808, permitting the frame exchange sequence to continue. The receipt of any other type of frame shall be interpreted as a failure of the transmission of MU-RTS trigger frame 808. AP 802 may process the received frame and, if MU-RTS trigger frame 808 initiated a TXOP, AP 802 shall invoke its backoff procedure at the PHY-RXEND. indication primitive.

[0089] In example 800, on receiving MU-RTS trigger frame 808, STAs 804 and 806 respond by transmitting respectively CTS frames 810 and 812 to AP 802. In an example, STAs 804 and 806 begin the transmissionDocket No.: 24-3056PCT of CTS frames 810 and 812, respectively, at the SIFS time boundary after an end of a received PPDU comprising MU-RTS trigger frame 808. In an example, STA 804 (or STA 806) responds to MU-RTS trigger frame 808 with a CTS frame when the following conditions are met: MU-RTS trigger frame 808 comprises a user info field addressed to the STA (the AID12 subfield of the user info field is equal to the 12 LSBs of the AID of the STA) and MU-RTS trigger frame 808 is sent by an AP with which the STA is associated; and the UL MU CS condition indicates that the medium is idle as described in section 26.5.2.5 (UL MU CS mechanism) of the IEEE 802.1 1 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.

[0090] In an example, STAs 804 and 806 may set an RA field of respectively CTS frames 810 and 812 to a TA obtained from the TA field of MU-RTS trigger frame 808. In an example, STAs 804 and 806 may set a duration field of respectively CTS frames 810 and 812 based on the duration field of MU-RTS trigger frame 808, namely as equal to the value of the duration field of MU-RTS trigger frame 808, adjusted by subtracting the time required to transmit respectively CTS frames 810 and 812 and one SIFS period.

[0091] OBSS STAs exposed to AP 802 may receive MU-RTS trigger frame 808 due to being within the communication range of AP 802. In an example, as shown in FIG. 8, on receiving MU-RTS trigger frame 808, OBSS STAs exposed to AP 802 set their respective NAVs based on the duration field of MU-RTS trigger frame 808. As such, the OBSS STAs exposed to AP 802 may not access the wireless medium for the duration of the TXOP initiated by AP 802.

[0092] 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.

[0093] 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.

[0094] 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), the STA may have one or more secondary channels considered as NPCA primary channels. 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. FIG. 9 shows an example that illustrates non-primary channel access (NPCA) operation. For theDocket No.: 24-3056PCT purpose of illustration, NPCA operation is contrasted with single primary channel (non-NPCA STA) operation. As shown in FIG. 9, the 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 .

[0095] 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).

[0096] In contrast, 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.

[0097] In implementations, the 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 STA may use the NPCA PCH for transmission if the NPCA PCH is idle (zero NAV and CCA indicates “channel idle”).

[0098] In an implementation, the STA may perform CS in parallel on multiple channels, including the PCH and the NPCA PCH. Such a STA is referred to herein as a concurrent CCA NPCA STA (such a STA may also be referred to as a concurrent CCA multiple primary channel (MPC) STA or a Type 1 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. An NPCA STA that does not support this capability may perform CSDocket No.: 24-3056PCT on a single channel at a time. In an implementation, an NPCA STA may perform CS on the PCH by default, and when the PCH is found busy, the STA may perform CS on the NPCA PCH. Such a STA is referred to herein as a non-concurrent CCA NPCA STA (such a STA may also be referred to as a non-concurrent CCA MPC STA or a Type 2 STA). In contrast to the 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.

[0099] FIG. 11 shows an example 1 100 that illustrates an NPCA operation. As shown in FIG. 11 , example 1 100 includes an AP and a STA associated with the AP. The AP and the STA may both support NPCA operation and may operate over a plurality of channels, including a primary channel (PCH), an NPCA primary channel (NPCA PCH), a first secondary channel (SCH1), and a second secondary channel (SCH2).

[0100] Example 1100 may begin with the AP transmitting a frame 1 102 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.

[0101] 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 1 104 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 1 104 on the PCH . Frame 1 104 may indicate a transmission 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 OBSS PPDU comprising frame 1 104, or a length field of the OBSS PPDU. The AP and STA may set their NAVs for the PCH based on the duration of the OBSS transmission on the PCH (OBSS NAV duration).

[0102] In accordance with NPCA operation, on receiving an OBSS 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.

[0103] 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 1 102). In example 1 100, 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 1 106 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 toDocket No.: 24-3056PCT 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.

[0104] Existing NPCA operation, however, does not envision the AP and STA switching to the NPCA PCH on detecting / receiving an intra-BSS PPDU (a PPDU transmitted by another STA of the same BSS as the AP / STA). For example, as shown in example 1200 of FIG. 12, on detecting / receiving an intra-BSS PPDU 1202 on the PCH, the AP and STA set their (intra-BSS) NAVs for the PCH (based on a NAV duration indicated in intra-BSS PPDU 1202) and remain on the PCH for the NAV duration. The AP and STA may communicate with each other after the end of the NAV duration via the PCH, for example by the AP transmitting to the STA a frame 1204 as shown in example 1200. However, in some cases, intra-BSS PPDU 1202 may not be addressed to either the AP or the STA. For example, intra-BSS PPDU 1202 may be a peer-to-peer (P2P) PPDU transmitted between two other STAs of the BSS. The AP and STA, therefore, may not need to remain on the PCH to receive intra-BSS PPDU 1202. Nevertheless, and despite that the NPCA PCH may be available during the NAV duration, the AP and STA do not switch to the NPCA PCH according to existing NPCA operation. In some cases, this may result in buffered traffic between the AP and STA being delayed and / or discarded (e.g., when the buffered traffic comprises low-latency traffic) and the NPCA PCH resources being wasted / under-utilized during the NAV duration.

[0105] To solve this problem, in an implementation, an AP may be configured, after (or based on) detecting an intra-BSS DL PPDU via the PCH, to switch from the PCH to an NPCA PCH. In an implementation, the AP supports a first NPCA mode according to which the AP switches from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU. In an implementation, the AP switches from the PCH to the NPCA PCH after detecting the intra-BSS DL PPDU on the PCH, based on the first NPCA mode being enabled (used, activated) at the AP. In another implementation, a STA, associated with the AP, may be configured, after (or based on) detecting an intra-BSS DL PPDU via the PCH, to switch from the PCH to the NPCA PCH. In an implementation, the STA supports a second NPCA mode according to which the STA switches from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU that is not addressed to the STA. In an implementation, the STA switches from the PCH to the NPCA PCH after detecting the intra-BSS DL PPDU on the PCH, based on the second NPCA mode being enabled (used, activated) at the STA. In an implementation, the AP may be configured to switch from the PCH to the NPCA PCH after detecting an intra- BSS DL PPDU on the PCH, based on the second NPCA mode being enabled (used, activated) at the STA. This ensures that the AP switches from the PCH to the NPCA PCH (after detecting an intra-BSS DL PPDU on the PCH) when the STA is also configured to switch from the PCH to the NPCA PCH (after detecting theDocket No.: 24-3056PCT intra-BSS DL PPDU on the PCH) and may thus communicate with the AP via the NPCA PCH. In another implementation, the STA may be configured to switch from the PCH to the NPCA PCH after detecting an intra-BSS DL PPDU on the PCH, based on the first NPCA mode being enabled (used, activated) at the AP. This ensures that the STA switches from the PCH to the NPCA PCH (after detecting an intra-BSS DL PPDU on the PCH) when the AP is also configured to switch from the PCH to the NPCA PCH (after detecting the intra-BSS DL PPDU on the PCH) and may thus communicate with the AP via the NPCA PCH.

[0106] FIG. 13 shows an example 1300 that illustrates an example NPCA operation according to an implementation. Example 1300 is provided for the purpose of illustration only and is not limiting of implementation. As shown in FIG. 13, example 1300 includes an AP 1302 and STAs 1304 and 1306. Example 1300 also includes a STA 1308 (not shown in FIG. 13). AP 1302 and STAs 1304, 1306, and 1308 belong to the same BSS. STAs 1304, 1306, and 1308 may be associated with AP 1302. AP 1302 and STAs 1304, 1306, and 1308 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). AP 1302 and STAs 1304, 1306, and 1308 may each support an NPCA (switching) mode (or NPCA operation mode).

[0107] In example 1300, AP 1302 supports a first NPCA mode. According to the first NPCA mode, AP 1302 may be configured to switch from the PCH to the NPCA PCH after detecting an intra-BSS DL PPDU on the PCH. In an implementation, AP 1302 may detect an intra-BSS DL PPDU based on receiving a PPDU that indicates a downlink transmission and that is transmitted by a first STA to a second STA. The first STA may belong to the BSS of AP 1302. The second STA may belong to the BSS of AP 1302. In an implementation, based on the downlink transmission indication of the PPDU, AP 1302 may determine that the PPDU comprises an intra-BSS P2P PPDU (i.e., a PPDU transmitted by the first STA directly (not via the AP) to the second STA).

[0108] In an implementation, AP 1302 may be configured to decode (read, detect, process, parse, or receive) a signal (SIG) field of the PPDU to determine whether the PPDU is an intra-BSS DL PPDU. In an implementation, AP 1302 may decode (read, detect, process, parse, or receive) a BSS color field of the SIG field. AP 1302 may determine that the PPDU is an intra-BSS PPDU based on the BSS color field indicating a BSS color (or a BSSID) of AP 1302. Additionally, or alternatively, AP 1302 may be configured to decode (read, detect, process, parse, or receive) an uplink / downlink (UL / DL) flag of the SIG field. AP 1302 may determine that the PPDU is a DL PPDU based on the UL / DL flag being to set to DL (or a value corresponding to DL). The SIG field may be located in a preamble part or in a PHY header of the PPDU. Depending on the type of PPDU, the SIG field may comprise a U-SIG, a UHR SIG, an EHT SIG, an HE SIG-A / B, a VHT SIG- A / B, or an HT SIG, for example. The SIG field may be a universal SIG (U-SIG) field, for example when the PPDU comprises an extremely high throughput (EHT) PPDU, an ultra-high reliability (UHR) PPDU, or aDocket No.: 24-3056PCTUHR+ PPDU. The SIG field may be an HE-SIG-A field, for example when the PPDU comprises a high efficiency (HE) PPDU.

[0109] In an implementation, AP 1302 may be configured to decode (read, detect, process, parse, or receive) the SIG field of the PPDU to determine duration information associated with the PPDU. The duration information may be for NAV setting and protection of a TXOP in which the PPDU is transmitted. AP 1302 may set a NAV for the PCH based on the duration information. In an implementation, AP 1302 may be configured to decode (read, detect, process, parse, or receive) a TXOP field of the SIG field to determine the duration information. The TXOP field may indicate a value of 0; a non-zero value; or a value of UNSPECFIED (e.g., all bits of the TXOP field set to 1 s).

[0110] In another implementation, AP 1302 may be configured to decode (read, detect, process, parse, or receive) an MPDU (or a MAC header of the MPDU) of the PPDU to determine whether the PPDU is an intra- BSS DL PPDU. The MPDU may be a first occurring MPDU of the PPDU. In an implementation, AP 1302 may decode (read, detect, process, parse, or receive) a BSSID field of (the MAC header of) the MPDU. AP 1302 may determine that the PPDU is an intra-BSS PPDU based on the BSSID field indicating a MAC address of AP 1302. Additionally, or alternatively, AP 1302 may be configured to decode (read, detect, process, parse, or receive) one or more Address fields (e.g., Address 1 (RA), Address 2 (TA), Address 3, and / or Address 4) of the MPDU. AP 1302 may determine that the PPDU Is a DL PPDU based on of the one more Address fields of the MPDU. For example, AP 1302 may determine that the PPDU is a DL PPDU based on an RA of the MPDU being set to a MAC header of another STA (I. e., other than AP 1302) of the BSS. In an implementation, AP 1302 may determine that the PPDU is a P2P PPDU based on a “To DS” subfield and a “From DS” subfield in a Frame Control field of a MAC header of the PPDU. For example, if the To DS subfield is equal to 0 and the From DS subfield is equal to 0, AP 1302 may determine that the PPDU is a P2P( / D2D) PPDU.

[0111] In another implementation, AP 1302 may be configured to decode (read, detect, process, parse, or receive) an MPDU (or a MAC header of the MPDU) of the PPDU to determine the duration information associated with the PPDU. AP 1302 may set a NAV for the PCH based on the duration information. In an implementation, AP 1302 may be configured to decode (read, detect, process, parse, or receive) a Duration / ID field (of the MAC header of) the MPDU to determine the duration information.

[0112] In an implementation, AP 1302 may enable (use, activate) or disable (unuse, deactivate) the first NPCA mode. AP 1302 may switch from the PCH to the NPCA PCH after detecting an intra-BSS DL PPDU on the PCH, based on the first NPCA mode being enabled (used, activated) AP 1302 may not switch from the PCH to the NPCA PCH after detecting an intra-BSS DL PPDU on the PCH, based on the first NPCA mode being disabled (unused, deactivated). In an implementation, AP 1302 switching to the NPCA PCH comprises AP 1302 operating (or camping, or parking) on the NPCA PCH.

[0113] In example 1300, STA 1304 supports a second NPCA mode (or NPCA operation mode). According to the second NPCA mode, STA 1304 may be configured to switch from the PCH to the NPCA PCH afterDocket No.: 24-3056PCT detecting an intra-BSS DL PPDU on the PCH. In an implementation, STA 1304 may detect an intra-BSS DL PPDU based on receiving a PPDU that indicates a downlink transmission and that is transmitted by a first STA, belonging to the BSS of STA 1304, to a second STA, belonging to the BSS of STA 1304. In an implementation, STA 1304 switches from the PCH to the NPCA PCH when the detected intra-BSS DL PPDU is not addressed to STA 1304. In an implementation, STA 1304 may not distinguish the detected intra-BSS DL PPDU as being a P2P PPDU.

[0114] In an implementation, STA 1304 may be configured to decode (read, detect, process, parse, or receive) a signal (SIG) field of the PPDU to determine whether the PPDU is an intra-BSS DL PPDU. In an implementation, STA 1304 may decode (read, detect, process, parse, or receive) a BSS color field of the SIG field. STA 1304 may determine that the PPDU is an intra-BSS PPDU based on the BSS color field indicating a BSS color (or a BSSID) of AP 1302 (with which STA 1304 is associated). Additionally, or alternatively, STA 1304 may be configured to decode (read, detect, process, parse, or receive) an uplink / downlink (UL / DL) flag of the SIG field. STA 1304 may determine that the PPDU is a DL PPDU based on the UL / DL flag being to set to DL (or a value corresponding to DL). Additionally, or alternatively, STA 1304 may be configured to decode (read, detect, process, parse, or receive) a field (e.g., STA ID) of the SIG field indicating a receiver of the PPDU. STA 1304 may determine whether the PPDU is addressed to STA 1304 based on this field. The SIG field may be located in a preamble part or in a PHY header of the PPDU. Depending on the type of PPDU, the SIG field may comprise a U-SIG, a UHR SIG, an EHT SIG, an HE SIG- A / B, a VHT SIG-A / B, or an HT SIG, for example. The SIG field may be a universal SIG (U-SIG) field, for example when the PPDU comprises an extremely high throughput (EHT) PPDU, an ultra-high reliability (UHR) PPDU, or a UHR+ PPDU. The SIG field may be an HE-SIG-A field, for example when the PPDU comprises a high efficiency (HE) PPDU.

[0115] In an implementation, STA 1304 may be configured to decode (read, detect, process, parse, or receive) the SIG field of the PPDU to determine duration information associated with the PPDU. The duration information may be for NAV setting and protection of a TXOP in which the PPDU is transmitted. STA 1304 may set a NAV for the PCH based on the duration information. In an implementation, STA 1304 may be configured to decode (read, detect, process, parse, or receive) a TXOP field of the SIG field to determine the duration information. The TXOP field may indicate a value of 0; a non-zero value; or a value of UNSPECFIED (e.g., all bits of the TXOP field set to 1 s).

[0116] In another implementation, STA 1304 may be configured to decode (read, detect, process, parse, or receive) an MPDU (or a MAC header of the MPDU) of the PPDU to determine whether the PPDU is an intra- BSS DL PPDU. The MPDU may be a first occurring MPDU of the PPDU. In an implementation, STA 1304 may decode (read, detect, process, parse, or receive) a BSSID field of (the MAC header of) the MPDU. STA 1304 may determine that the PPDU is an intra-BSS PPDU based on the BSSID field indicating a MAC address of AP 1302 (with which STA 1304 is associated). Additionally, or alternatively, STA 1304 may beDocket No.: 24-3056PCT configured to decode (read, detect, process, parse, or receive) one or more Address fields (e.g., Address 1 (RA), Address 2 (TA), Address 3, and / or Address 4) of the MPDU. STA 1304 may determine that the PPDU is a DL PPDU based on of the one more Address fields of the MPDU. For example, STA 1304 may determine that the PPDU is a DL PPDU based on an RA of the MPDU being set to a MAC header of a STA other than AP 1302 of the BSS. In an implementation, STA 1304 may determine that the PPDU is a P2P PPDU based on a “To DS” subfield and a “From DS” subfield in a Frame Control field of a MAC header of the PPDU. For example, if the To DS subfield is equal to 0 and the From DS subfield is equal to O, STA 1304 may determine that the PPDU is a P2P( / D2D) PPDU.

[0117] In another implementation, STA 1304 may be configured to decode (read, detect, process, parse, or receive) an MPDU (or a MAC header of the MPDU) of the PPDU to determine the duration information associated with the PPDU. STA 1304 may set a NAV for the PCH based on the duration information. In an implementation, STA 1304 may be configured to decode (read, detect, process, parse, or receive) a Duration / ID field (of the MAC header of) the MPDU to determine the duration information.

[0118] In an implementation, STA 1304 may enable (use, activate) or disable (unuse, deactivate) the second NPCA mode. STA 1304 may switch from the PCH to the NPCA PCH after detecting an intra-BSS DL PPDU on the PCH, based on the second NPCA mode being enabled (used, activated). STA 1304 may not switch from the PCH to the NPCA PCH after detecting an intra-BSS DL PPDU on the PCH, based on the second NPCA mode being disabled (unused, deactivated). In an implementation, STA 1304 switching to the NPCA PCH comprises STA 1304 operating (or camping, or parking) on the NPCA PCH.

[0119] Returning to FIG. 13, example 1300 begins with STA 1306 transmitting a PPDU 1310 on the PCH to STA 1308 (not shown in FIG. 13). As AP 1302 and STA 1304 operate on the PCH, AP 1302 and STA 1304 may (in parallel) detect / sense the transmission of PPDU 1310 and begin to decode (read, detect, process, parse, or receive) PPDU 1310. In an example, AP 1302 and STA 1304 may decode (read, detect, process, parse, or receive) a PHY identifier field of PPDU 1310, which allows AP 1302 and STA 1304 to determine a PPDU type of PPDU 1310.

[0120] Next, in an implementation, AP 1302 and STA 1304 may decode (read, detect, process, parse, or receive) a preamble / PHY header of PPDU 1310 to determine if PPDU 1310 is an intra-BSS DL PPDU. As described above, AP 1302 and STA 1304 may decode (read, detect, process, parse, or receive) a BSS color field of a SIG field of the preamble / PHY header to determine whether PPDU 1310 is an intra-BSS PPDU . In example 1300, AP 1302 and STA 1304 may determine that PPDU 1310 is an intra-BSS PPDU based on the BSS color field indicating a BSS color (or a BSSID) of AP 1302. Additionally, AP 1302 and STA 1304 may decode (read, detect, process, parse, or receive) an UL / DL flag of the SIG field to determine whether PPDU 1310 is a DL PPDU. In example 1300, AP 1302 and STA 1304 may determine that PPDU 1310 is a DL PPDU based on the UL / DL flag being to set to DL (or a value corresponding to DL). Additionally, STA 1304 may decode (read, detect, process, parse, or receive) a field (e.g., STA ID) of the SIG field that indicates a receiverDocket No.: 24-3056PCT of PPDU 1310. In example 1300, STA 1304 may determine that PPDU 1310 is addressed to STA 1308 and not to STA 1304.

[0121] In another implementation (not shown in FIG. 13), alternatively or additionally, AP 1302 and STA 1304 may decode (read, detect, process, parse, or receive) an MPDU (or a MAC header of the MPDU) of PPDU 1310 to determine if PPDU 1310 is an intra-BSS DL PPDU. The MPDU may be a first occurring MPDU of PPDU 1310. In an implementation, AP 1302 and STA 1304 may be configured to decode (read, detect, process, parse, or receive) the MPDU of PPDU 1310 to determine if PPDU 1310 is an intra-BSS DL PPDU based on failing to determine whether PPDU 1310 is an intra-BSS PPDU and / or a DL PPDU based on reading / decoding the preamble / PHY header of PPDU 1310. As described above, AP 1302 and STA 1304 may decode (read, detect, process, parse, or receive) a BSSID field of the MPDU to determine whether the BSSID field indicates a MAC address of AP 1302. Additionally, or alternatively, AP 1302 may decode (read, detect, process, parse, or receive) one or more Address fields (e.g., Address 1(RA), Address 2 (TA), Address 3, and / or Address 4) of the MPDU. AP 1302 may determine that the PPDU is a DL PPDU based on of the one more Address fields of the MPDU. For example, AP 1302 may determine that the PPDU is a DL PPDU based on an RA of the MPDU being set to a MAC header of another STA (i.e., other than AP 1302) of the BSS. In an implementation, AP 1302 may determine that the PPDU is a P2P PPDU based on a "To DS” subfield and a “From DS” subfield in a Frame Control field of a MAC header of the PPDU. For example, if the To DS subfield is equal to 0 and the From DS subfield is equal to 0, AP 1302 may determine that the PPDU is a P2P( / D2D) PPDU.

[0122] Continuing with example 1300, after determining that PPDU 1310 is an intra-BSS DL PPDU, AP 1302 switches from the PCH to the NPCA PCH. Similarly, after determining that PPDU 1310 is an intra-BSS DL PPDU not addressed to STA 1304, STA 1304 switches from the PCH to the NPCA PCH. In an implementation, AP 1302 and STA 1304 may be configured to switch to the NPCA PCH at the same switching time. The switching time may correspond to the time that AP 1302 and STA 1304 finish decoding / reading the SIG field of PPDU 1310, for example. However, other switching times may also be configured or negotiated / agreed between AP 1302 and STA 1304.

[0123] Subsequently, AP 1302 may access the NPCA PCH and transmit a frame 1312 to STA 1304. As shown in FIG. 13, frame 1312 may be transmitted via a bandwidth that comprises the NPCA PCH. For example, frame 1312 may be transmitted via the NPCH PCH and SCH2. Frame 1312 may comprise an initial control frame (ICF), a request-to-send (RTS) frame, a multi-user (MU)-RTS frame, a buffer status report poll (BSRP) trigger frame, a block ack request (BAR) frame, a clear-to-send (CTS) frame, a block ack (BA) frame, an acknowledgment (Ack) frame, a buffer status report (BSR) frame, an initial control response frame (ICR), a request frame, a control frame, a management frame, or an action frame, for example. STA 1304 may respond to frame 1312 from AP 1302 by transmitting a frame 1314 to AP 1302. Frame 1314 may comprise a clear-to-send (CTS) frame, a BlockAck (BA) frame, an acknowledgment (Ack) frame, a buffer status reportDocket No.: 24-3056PCT(BSR) frame, an initial control response frame (ICR), a response frame, a control frame, a management frame, or an action frame, for example.

[0124] AP 1302 may then transmit a frame 1316 to STA 1304. Frame 1316 may comprise a data frame, a management frame, or an action frame, for example. STA 1304 may respond to frame 1316 by transmitting a frame 1318 to AP 1302. Frame 1318 may comprise an immediate response frame, such as an Ack frame or a BA frame. As such, communication between AP 1302 and STA 1304 may occur on the NPCA PCH during at least the transmission time of PPDU 1310 by STA 1306 to STA 1308 on the PCH. This allows for buffered traffic between AP 1302 and STA 1304 to be transmitted with minimal delay and avoids NPCA PCH resources from being wasted.

[0125] In an implementation, AP 1302 and STA 1304 may switch to the NPCA PCH as described above, without determining the duration information (NAV / TXOP duration) associated with PPDU 1310. Accordingly, AP 1302 and STA 1304 may be configured to finish communicating on the NPCA PCH and return to the PCH before an end of PPDU 1310. In another implementation, AP 1302 and STA 1304 may only switch to the NPCA PCH after determining the NAV / TXOP duration associated with PPDU 1310. As such, AP 1302 and STA 1304 may be configured to return to the PCH before an end of the NAV / TXOP duration associated with PPDU 1310. In an implementation, AP 1302 and STA 1304 may be configured to operate on the NPCA PCH until an end of the NAV / TXOP duration associated with PPDU 1310 duration as shown in FIG. 18.

[0126] FIG. 14 shows an example 1400 that illustrates an example NPCA operation according to an implementation. Example 1400 also includes AP 1302, STA 1304, and STA 1306 described above in FIG. 13. In FIG. 14, AP 1302 transmits a DL PPDU 1410 to STA 1306. When STA 1304 receives PPDU 1410, if STA 1304 detects / determines that PPDU 1410 is an intra-BSS DL PPDU, STA 1304 may determine to switch to the NPCA PCH at the NPCA PCH switch time. After switching to the NPCA PCH, if STA 1304 does not receive a frame from AP 1302 (or does not communicate with AP 1302) on the NPCA PCH during a specific time period, STA 1304 may be configured to return to the PCH from the NPCA PCH before an end of a duration ( / length) of PPDU 1410. In an example, the specific time period is based / determined based on the duration / length of PPDU 1410. For example, the specific time period may be equal to or less than the duration / length of PPDU 1410. After switching to the NPCA PCH, STA 1304 may transmit one or more frames (e.g., frame 1412, frame 1414, frame 1416 in FIG. 14) to AP 1302 on the NPCA PCH before returning to the PCH. In an implementation, based on STA 1304 not receiving a response to the one or more frames, STA 1304 may determine that AP 1302 did not switch to the NPCA PCH based on PPDU 1410 In an implementation, based on determining that AP 1302 did not switch to the NPCA PCH, STA 1304 may determine that AP transmitted PPDU 1410.

[0127] As described in FIG. 14, while AP 1302 transmits PPDU 1410 to STA 1306, STA 1304 determines / detects that PPDU 1410 is an intra-BSS DL PPDU. Based on the determining, STA 1304 switches from the PCH to the NPCA PCH and transmits to AP 1302 the one or more frames (e.g., frame 1412, frameDocket No.: 24-3056PCT1414, frame 1416). As AP 1302 remains on the PCH, STA 1304 does not receive any frame from AP 1302 in response to the one or more frames during the specific time period (e.g . , the duration / length of PPDU 1410) and switches back from the NPCA PCH to the PCH. These switching operations by STA 1304 based on PPDU 1410 (e.g., from the PCH to the NPCA PCH and again from the NPCA PCH to the PCH) and the transmission of the one or more frames (e.g., frame 1412, 1414, 1416) that are not received by AP 1302 increases power consumption at STA 1304. Additionally, the one or more frames may needlessly consume resources of the NPCA PCH and may interfere / contend with other transmissions on the NPCA PCH.

[0128] Embodiments of the present disclosure, as further described below, address the above-described problem of existing technologies. In an aspect, a first STA (e.g., non-AP STA) may be configured to receive from an AP, a first frame indicating a second STA having a peer-to-peer (PTP) link. For example, the first STA may be associated with the AP. In an aspect, the first STA may be configured to determine that a physical layer protocol data unit (PPDU) being received via a primary channel (PCH) comprises an intra- basic service set (intra-BSS) downlink (DL) and that the PPDU indicates the second STA. In an aspect, the first STA may be configured, based on the determination, to switch from the PCH to a non-primary channel access (NPCA) PCH. In an aspect, the first STA may be configured, after switching from the PCH to the NPCA PCH, to communicate with the AP. The first STA may have a first identifier (ID). The second STA may have a second ID. The second STA may have the PTP link with a third STA. The third STA may have a third ID. The PPDU may comprise a STA ID field comprising the second ID or the third ID. The first frame may indicate the third STA. The first frame may indicate other STA having a PTP link. The first frame may comprise the second ID and the third ID. The first frame may comprise a STA ID list comprising the second ID and the third ID. The first STA may detect the PPDU comprising the intra-BSS DL PPDU. The first STA may not switch from the PCH to the NPCA PCH based on detecting the PPDU comprising a STA ID field equal to an identifier that is not in the STA ID list. The first STA may communicate with the AP on the NPCA PCH.

[0129] In another aspect, an access point (AP) may be configured to transmit to a first station (STA) a first frame indicating a second STA identifier (ID) of a second STA. The second STA may have a peer-to-peer (PTP) link with a third STA. The first STA may have a first STA ID. In an aspect, the AP may be configured to determine that a physical layer protocol data unit (PPDU) being received via a primary channel (PCH) may comprise an intra-basic service set (intra-BSS) downlink (DL). In an aspect, the AP may be configured to, based on the determining, switch from the PCH to a non-primary channel access (NPCA) PCH.

[0130] FIG. 15 shows an example 1500 that illustrates another NPCA operation according to an embodiment. Example 1500 is provided for the purpose of illustration only and is not limiting of embodiments. As shown in FIG. 15, example 1500 also includes AP 1302 and STAs 1304, 1306, and 1308 (not shown in FIG. 15) described above in FIG. 13. In example 1500, STA 1306 has a peer-to-peer (PTP) link with STA 1308.Docket No.: 24-3056PCT

[0131] Example 1500 may begin with AP 1302 transmitting a frame 1502 via the PCH. Frame 1502 may indicate whether AP 1302 supports the first NPCA mode described above. Frame 1502 may further indicate the STAs, associated with AP 1302, that have PTP links. As such, in example 1500, frame 1502 may further indicate STA 1306 and / or STA 1308. In an embodiment, frame 1502 may indicate the STA IDs of the STAs that have PTP links. As such, in example 1500, frame 1502 may indicate / comprise a second ID of STA 1306 and / or a third ID of STA 1308. In an embodiment, frame 1502 may comprise a STA ID list comprising the second ID and the third ID. Frame 1502 may comprise one of a beacon frame, a fast initial link setup (FILS) discovery frame, a short beacon frame, a traffic indication map (TIM) broadcast frame, a probe response frame, an association response frame, an individually addressed management frame, a group addressed management frame, a control frame, an action frame, a QoS data frame, a QoS null frame, a broadcast frame, or an announcement frame.

[0132] As described above, according to the first NPCA mode, AP 1302 may switch from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU. In an embodiment, when AP 1302 supports the first NPCA mode, AP 1302 may be configured to switch from the PCH to the NPCA PCH (after detecting on the PCH an intra-BSS DL PPDU) on condition that at least one STA associated with AP 1302 supports (or supports and has indicated enablement / activation of) a mode (e.g., the second NPCA mode) according to which the STA switches from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU. The intra-BSS DL PPDU may comprise a STA ID field comprising / indicating a STA ID of a STA having a PTP link.

[0133] Subsequently, example 1500 may include STA 1304 transmitting a frame 1504 to AP 1302. Frame 1504 may indicate whether STA 1304 supports the second NPCA mode. As described above, according to the second NPCA mode, STA 1304 may switch from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU that is not addressed to STA 1304. In an embodiment, STA 1304 may further be configured to switch from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU indicating an identifier of a STA indicated in the STA ID list of frame 1502 (e.g., ID of STA 1306 or ID of STA 1308). In an embodiment, when STA 1304 supports the second NPCA mode, STA 1304 may be configured to switch from the PCH to the NPCA PCH (after detecting on the PCH an intra-BSS DL PPDU not addressed to it) on condition that AP 1302 (with which STA 1304 is associated) supports (or supports and has indicated enablement / activation of) a mode (e.g., the first NPCA mode) according to which AP 1302 switches from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU. The intra-BSS DL PPDU may comprise a STA ID field comprising / indicating a STA ID of a STA having a PTP link.

[0134] In another embodiment, additionally or alternatively, frame 1504 may indicate enablement / disablement (activation / deactivation) of the second NPCA mode at STA 1304. In an embodiment, when STA 1304 has enabled (used, activated) the second NPCA mode, STA 1304 may be configured to switch from the PCH to the NPCA PCH (after detecting on the PCH an intra-BSS DL PPDU notDocket No.: 24-3056PCT addressed to it) on condition that AP 1302 (with which STA 1304 is associated) supports (or supports and has indicated enablement / activation of) a mode (e.g., the first NPCA mode) according to which AP 1302 switches from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU.

[0135] Frame 1504 may comprise a probe request frame, an association request frame, a reassociation request frame, a request frame, a management frame, an action frame, a control frame, a quality of service (QoS) null frame, or a QoS data frame, for example.

[0136] In an embodiment, AP 1302 may respond to frame 1504 from STA 1304 by transmitting a frame 1506 to STA 1304. In another embodiment, AP 1302 may not respond to frame 1504 from STA 1304. In an embodiment, frame 1506 acknowledges frame 1504. In another embodiment, frame 1506 responds to frame 1504. In an embodiment, frame 1506 indicates whether AP 1302 supports the first NPCA mode described above. Frame 1506 may further indicate STA 1306 and / or STA 1308. Frame 1506 may comprise the second ID and the third ID Frame 1506 may comprise a STA ID list comprising the second ID and the third ID In another embodiment, additionally or alternatively, frame 1506 may indicate enablement / disablement (activation / deactivation) of the first NPCA mode at AP 1302. In an embodiment, when AP 1302 has enabled (used, activated) the first NPCA mode, AP 1302 may be configured to switch from the PCH to the NPCA PCH (after detecting on the PCH an intra-BSS DL PPDU) on condition that at least one STA associated with AP 1302 supports (or supports and has indicated enablement / activation of) a mode (e.g., the second NPCA mode) according to which the STA switches from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU. In an embodiment, in response to frame 1504 indicating enablement / activation of the second NPCA mode at STA 1304, AP 1302 may transmit frame 1506 indicating enablement / activation of the first NPCA mode at AP 1302. That is, AP 1302 may enable / activate the first NPCA mode in response to STA 1304 indicating enablement / activation of the second NPCA mode. Frame 1506 may comprise a probe response frame, an association response frame, a reassociation response frame, a response frame, a management frame, an action frame, a control frame, a quality of service (QoS) null frame, or a QoS data frame, for example. In an embodiment, STA 1304 may switch from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU indicating an identifier of a STA indicated in the STA ID list of frame 1406 (e.g., ID of STA 1306 or ID of STA 1308).

[0137] Subsequently, example 1500 may include STA 1306 transmitting a PPDU 1310 to STA 1308. STA 1304 may determine PPDU 1310 being transmitted comprises an intra-BSS PPDU indicating STA 1308 that is in the STA ID list of frame 1502 or Frame 1506. In an embodiment, based on the determination, STA 1304 may switch from the PCH to the NPCA PCH. PPDU 1310 may comprise a BSS color for AP 1302, UL / DL flag equal to DL, and / or STA ID equal to an identifier of STA 1308. AP 1302 may determine PPDU 1310 being transmitted comprises an intra-BSS PPDU indicating STA 1308 that is in the STA ID list of frame 1502 or Frame 1506. In an embodiment, based on the determination, AP 1302 may switch from the PCH to theDocket No.: 24-3056PCTNPCA PCH. PPDU 1310 may comprise a BSS color for AP 1302, UL / DL flag equal to DL, and / or STA ID equal to an identifier of STA 1308.

[0138] Subsequently, AP 1302 may access the NPCA PCH and transmit a frame 1512 to STA 1304. Frame 1512 may be similar to frame 1312 described above. STA 1304 may respond to frame 1512 from AP 1302 by transmitting a frame 1514 to AP 1302. Frame 1514 may be similar to frame 1314 described above. AP 1302 may then transmit a frame 1516 to STA 1304. Frame 1516 may be similar to frame 1316 described above. STA 1304 may respond to frame 1516 by transmitting a frame 1518 to AP 1302. Frame 1518 may be similar to frame 1318 described above. As such, communication between AP 1302 and STA 1304 may occur on the NPCA PCH during at least the transmission time of PPDU 1310 by STA 1306 to STA 1308 on the PCH. This allows for buffered traffic between AP 1302 and STA 1304 to be transmitted with minimal delay and avoids NPCA PCH resources from being wasted. Further, STA 1304 only switches to the NPCA PCH when PPDU 1310 is an intra-BSS DL PPDU indicating an identifier of a STA indicated in the STA ID list of frame 1502 or frame 1506.

[0139] In an embodiment, AP 1302 and STA 1304 may switch to the NPCA PCH as described above, without determining the duration information (NAV / TXOP duration) associated with PPDU 1510. Accordingly, AP 1302 and STA 1304 may be configured to finish communicating on the NPCA PCH and return to the PCH before an end of PPDU 1310. In another embodiment, AP 1302 and STA 1304 may only switch to the NPCA PCH after determining the NAV / TXOP duration associated with PPDU 1310. As such, AP 1302 and STA 1304 may be configured to return to the PCH before an end of the NAV / TXOP duration associated with PPDU 1310.

[0140] FIG. 16 shows an example 1600 that illustrates another NPCA operation according to an embodiment. Example 1600 is provided for the purpose of illustration only and is not limiting of embodiments. As shown in FIG. 16, example 1600 also includes AP 1302 and STAs 1304, 1306, and 1308 (not shown in FIG. 16) described above in FIG. 13. Additionally, example 1600 includes / refers to a STA 1608 (not shown in FIG. 13). In example 1600, STA 1308 has a PTP link with STA 1608.

[0141] Example 1600 may begin with AP 1302 transmitting a frame 1602 via the PCH. Frame 1602 may indicate whether AP 1302 supports the first NPCA mode described above. Frame 1602 may further indicate the STAs, associated with AP 1302, that have PTP links. As such, in example 1600, frame 1602 may further indicate STA 1308 and / or STA 1608. In an embodiment, frame 1602 may indicate the STA IDs of the STAs that have PTP links. As such, in example 1600, frame 1602 may indicate / comprise a second ID of STA 1308 and / or a third ID of STA 1608. In an embodiment, frame 1602 may comprise a STA ID list comprising the second ID and the third ID. Frame 1602 may comprise a beacon frame, a traffic indication map (TIM) broadcast frame, a probe response frame, an association response frame, an individually addressed management frame, a group addressed management frame, a control frame, an action frame, a QoS data frame, or a QoS null frame.Docket No.: 24-3056PCT

[0142] As described above, according to the first NPCA mode, AP 1302 may switch from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU. In an embodiment, when AP 1302 supports the first NPCA mode, AP 1302 may be configured to switch from the PCH to the NPCA PCH (after detecting on the PCH an intra-BSS DL PPDU) on condition that at least one STA associated with AP 1302 supports (or supports and has indicated enablement / activation of) a mode (e.g., the second NPCA mode) according to which the STA switches from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU. The intra-BSS DL PPDU may comprise a STA ID field comprising / indicating a STA ID of a STA having a PTP link.

[0143] Subsequently, example 1600 may include STA 1304 transmitting a frame 1604 to AP 1302. Frame 1604 may indicate whether STA 1304 supports the second NPCA mode. As described above, according to the second NPCA mode, STA 1304 may switch from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU that is not addressed to STA 1304. In an embodiment, STA 1304 may switch from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU indicating an identifier of a STA indicated in the STA ID list of frame 1602 (e.g., ID of STA 1308 or ID of STA 1608). In an embodiment, when STA 1304 supports the second NPCA mode, STA 1304 may be configured to switch from the PCH to the NPCA PCH (after detecting on the PCH an intra-BSS DL PPDU not addressed to it) on condition that AP 1302 (with which STA 1304 is associated) supports (or supports and has indicated enablement / activation of) a mode (e.g., the first NPCA mode) according to which AP 1302 switches from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU. The intra-BSS DL PPDU may comprise a STA ID field comprising / indicating a STA ID of a STA having a PTP link.

[0144] Subsequently, example 1600 may include AP 1302 transmitting a frame 1606 to STA 1304. Frame 1602 may further indicate the STAs, associated with AP 1302, that have PTP links. As such, in example 1600, frame 1602 may further indicate STA 1308 and / or STA 1608. In an embodiment, frame 1602 may indicate the STA IDs of the STAs that have PTP links. As such, in example 1600, frame 1602 may indicate / comprise a second ID of STA 1308 and / or a third ID of STA 1608. In an embodiment, frame 1602 may comprise a STA ID list comprising the second ID and the third ID. In an embodiment, STA 1304 may switch from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU indicating an identifier of a STA indicated in the STA ID list of frame 1606 (e.g., ID of STA 1308 or ID of STA 1608).

[0145] Subsequently, example 1600 may include AP 1302 transmitting a PPDU 1610 to STA 1306. PPDU 1610 may comprise a BSS color for AP 1302, an UL / DL flag equal to DL, and a STA ID field set to an identifier of STA 1306. STA 1304 may determine that PPDU 1610 comprises an intra-BSS PPDU based on the BSS color of PPDU 1610. Additionally, STA 1304 may determine that the STA ID field of PPDU 1610 indicates STA 1306, which is not in the STA ID list of frame 1602 or frame 1606. In an embodiment, based on this determination, STA 1304 may not switch from the PCH to the NPCA PCH based on PPDU 1610. Instead, STA 1304 may continue to operate on the PCH.Docket No.: 24-3056PCT

[0146] FIG. 17 shows an example 1700 that illustrates another NPCA operation 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 1302 and STAs 1304, 1306, and 1308 (not shown in FIG. 17) described above in FIG. 13. In example 1700, STA 1306 has a peer-to-peer (PTP) link with STA 1308.

[0147] Example 1700 may begin with AP 1302 transmitting a frame 1702 via the PCH. Frame 1702 may request PTP information from STA 1306 (e.g, whether STA 1306 has a PTP link, or an identifier (or MAC address) of a peer STA of STA 1306, etc.). Frame 1702 may indicate whether AP 1302 solicits a frame 1704 from STASTA 1306. Frame 1702 may comprise one of a management frame, a control frame, an action frame, a QoS data frame, or a QoS null frame.

[0148] Subsequently, example 1700 may include STA 1306 transmitting frame 1704 to AP 1302 in response to frame 1702. In another embodiment, STA 1306 may transmit frame 1704 to AP 1302 without receiving frame 1702. Frame 1704 may indicate PTP link information. The PTP link information may comprise an indication of whether STA 1306 has a PTP link. The PTP link information may comprise an identifier (e.g., STA ID, AID) or a MAC address of a peer STA (e.g., STA 1308) of STA 1306. Frame 1704 may comprise one of a management frame, a control frame, an action frame, a QoS data frame, or a QoS null frame, for example.

[0149] In an embodiment, AP 1302 may configure a PTP STA list (e.g., STA 1306, STA 1308) based on frame 1704.

[0150] In an embodiment, AP 1302 may transmit to STA 1304 a frame 1706. Frame 1706 may indicate STA 1306 and / or STA 1308. Frame 1706 may comprise a second ID of STA 1306 (e.g., AID / STA ID of STA 1306) and a third ID of STA 1308 (e.g., AID / STA ID of STA 1308). Frame 1706 may comprise a STA ID list comprising the second ID and the third ID. Frame 1706 may comprise a management frame, a control frame, an action frame, a QoS data frame, or a QoS null frame, for example.

[0151] In an embodiment, STA 1304 may be configured to switch from the PCH to the NPCA PCH after detecting on the PCH an intra-BSS DL PPDU indicating an identifier of a STA indicated in the STA ID list of frame 1706 (e.g, ID of STA 1306 or ID of STA 1308).

[0152] Subsequently, example 1700 may include STA 1306 transmitting a PPDU 1310 to STA 1308. PPDU 1310 may comprise a BSS color for AP 1302, UL / DL flag equal to DL, and / or a STA ID equal to an identifier (e.g, 11 LSBs of AID) of a STA 1308. STA 1304 may determine PPDU 1310 comprises an intra-BSS PPDU indicating STA 1308 which is in the STA ID list of frame 1706. In an embodiment, based on the determination, STA 1304 may switch from the PCH to the NPCA PCH. AP 1302 may determine PPDU 1310 being transmitted comprises an intra-BSS PPDU indicating STA 1308 which is in the STA ID list of frame 1706. In an embodiment, based on the determination, AP 1302 may switch from the PCH to the NPCA PCH.Docket No.: 24-3056PCT

[0153] Subsequently, AP 1302 may access the NPCA PCH and transmit a frame 1712 to STA 1304. Frame 1712 may be similar to frame 1312 described above. STA 1304 may respond to frame 1712 from AP 1302 by transmitting a frame 1714 to AP 1302. Frame 1714 may be similar to frame 1314 described above. AP 1302 may then transmit a frame 1716 to STA 1304. Frame 1716 may be similar to frame 1316 described above. STA 1304 may respond to frame 1716 by transmitting a frame 1718 to AP 1302. Frame 1718 may be similar to frame 1318 described above. As such, communication between AP 1302 and STA 1304 may occur on the NPCA PCH during at least the transmission time of PPDU 1310 by STA 1306 to STA 1308 on the PCH. This allows for buffered traffic between AP 1302 and STA 1304 to be transmitted with minimal delay and avoids NPCA PCH resources from being wasted. Further, STA 1304 only switches to the NPCA PCH when PPDU 1310 is an intra-BSS DL PPDU indicating an identifier of a STA indicated in the STA ID list of frame 1706.

[0154] In an embodiment, AP 1302 and STA 1304 may switch to the NPCA PCH as described above, without determining the duration information (NAV / TXOP duration) associated with PPDU 1310. Accordingly, AP 1302 and STA 1304 may be configured to finish communicating on the NPCA PCH and return to the PCH before an end of PPDU 1310. In another embodiment, AP 1302 and STA 1304 may only switch to the NPCA PCH after determining the NAV / TXOP duration associated with PPDU 1310. As such, AP 1302 and STA 1304 may be configured to return to the PCH before an end of the NAV / TXOP duration associated with PPDU 1310.

[0155] FIG. 18 illustrates another example process 1800 according to an embodiment. Example process 1800 is provided for the purpose of illustration only and is not limiting of embodiments. Example process 1800 may be performed by a first STA, such as STA 1304, for example. As shown in FIG. 18, example process 1800 may include steps 1802, 1804, and 1806. The first STA may be associated with an AP.

[0156] Step 1802 includes receiving, by a first STA from an AP, a first frame indicating a second STA having a peer-to-peer (FTP) link.

[0157] Step 1804 includes determining, by the first STA, that a physical layer protocol data unit (PPDU) being received via a primary channel (PCH) comprises an intra-basic service set (intra-BSS) downlink (DL) PPDU and that the PPDU indicates the second STA.

[0158] Step 1806 includes, based on the determining, switching, by the first STA, from the PCH to a nonprimary channel access (NPCA) PCH.

[0159] In an embodiment, the first STA may be associated with the AP. The first STA may have a first identifier (ID). The second STA may have a second ID. The second STA may have the PTP link with a third STA. The third STA may have a third ID. In an embodiment, the PPDU may comprise a STA ID field comprising the second ID or the third ID.

[0160] In an embodiment, the first frame may indicate the third STA. In an embodiment, the first frame may indicate a further STA having a PTP link. In an embodiment, where the second STA has the PTP link withDocket No.: 24-3056PCT the third STA, the first frame may comprise the second ID and the third ID. In an embodiment, the first frame may comprise a STA ID list comprising the second ID and the third ID.

[0161] In an embodiment, process 1800 may further comprise not switching, by the first STA, from the PCH to the NPCA PCH based on determining that the PPDU comprises a STA ID field set to an identifier that is not in the STA ID list.

[0162] In an embodiment, process 1800 may further comprise the first STA detecting the PPDU comprising the intra-BSS DL PPDU.

[0163] In an embodiment, process 1800 may further comprise communicating, by the first STA, with the AP on the NPCA PCH. The communicating, by the first STA, with the AP may comprise transmitting, by the first STA to the AP and during a period / duration indicated by the PPDU, a second frame. The second frame may comprise a control frame, a data frame, or a management frame. The communicating, by the first STA, with the AP may comprise receiving, by the first STA from the AP during a period / duration indicated by the PPDU, a third frame. The third frame may comprise a control frame, a data frame, or a management frame.

[0164] In an embodiment, the first frame may comprise one of a beacon frame, a traffic indication map (TIM) broadcast frame, a probe response frame, an association response frame, an individually addressed management frame, a group addressed management frame, a control frame, an action frame, a QoS data frame, or a QoS null frame.

[0165] 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 an AP, such as AP 1302, for example. As shown in FIG. 19, example process 1900 may include steps 1902, 1904, and 1906.

[0166] Step 1902 includes transmitting, by the AP from to first STA, a first frame indicating a second STA having a peer-to-peer (PTP) link.

[0167] Step 1904 includes determining, by the AP, that a physical layer protocol data unit (PPDU) being received via a primary channel (PCH) comprises an intra-basic service set (intra-BSS) downlink (DL) PPDU.

[0168] Step 1906 includes, based on the determining, switching, by an AP, from the PCH to a non-primary channel access (NPCA) PCH.

[0169] In an embodiment, the first STA may be associated with the AP. The first STA may have a first identifier (ID). The second STA may have a second ID. The second STA may have the PTP link with a third STA. The third STA may have a third ID. In an embodiment, he PPDU may comprise a STA ID field comprising the second ID or the third ID.

[0170] In an embodiment, the first frame may indicate the third STA. In an embodiment, the first frame may indicate a further STA having a PTP link. In an embodiment, where the second STA has the PTP link with the third, the first frame may comprise the second ID and the third ID. In an embodiment, the first frame may comprise a STA ID list comprising the second ID and the third ID.Docket No.: 24-3056PCT

[0171] In an embodiment, the first STA may switch from the PCH to the NPCA PCH based on determining that the PPDU comprises a STA ID field set to an identifier that is in the STA ID list. In an embodiment, the first STA may not switch from the PCH to the NPCA PCH based on determining that the PPDU comprises a STA ID field set to an identifier that is not in the STA ID list.

[0172] In an embodiment, process 1900 may further comprise detecting, by the AP, the PPDU comprising the intra-BSS DL PPDU.

[0173] In an embodiment, process 1900 may further comprise communicating, by the AP, with the first STA on the NPCA PCH. The communicating, by the AP, with the first STA may comprise transmitting, by the AP to first STA and during a period / duration indicated by the PPDU, a second frame. The second frame comprises a control frame, a data frame, or a management frame. The communicating, by the AP, with the first STA may comprise receiving, by the AP from the first STA during a period / duration indicated by the PPDU, a third frame. The third frame may comprise a control frame, a data frame, or a management frame.

[0174] In an embodiment, the first frame may comprise one of a beacon frame, a traffic indication map (TIM) broadcast frame, a probe response frame, an association response frame, an individually addressed management frame, a group addressed management frame, a control frame, an action frame, a QoS data frame, or a QoS null frame.

[0175] In an embodiment, an AP (e.g., AP 1302) may not be configured to transmit to a first STA a first frame indicating a second STA's identifier (ID). For example, the AP may not know which STA has a PTP link with a peer STA, e.g., if the AP does not track(Zmonitor) PTP link related frames (e.g., TDLS Discovery Request frame or TDLS Setup Request frame) and does not maintain a list of STAs that have PTP links (e.g., TDLS PTP link). In an embodiment, the AP may transmit to the second STA a request fame asking the second STA whether the second STA has a PTP link (e.g., TDLS link). After the second STA receives the request frame, the second STA may send to the AP a response frame indicating whether the second STA has a PTP link. The response frame may further comprise an identifier (e.g., STA ID, AID) or address (e.g., MAC address) of a peer STA associated with the PTP link. Based on the response frame comprising the PTP link presence indication and the peer STA’s ID information (e.g., second STA's ID), the AP may configure a PTP link information comprising the peer STA’s ID (e.g., second STA's ID). The AP may be configured to transmit to the first STA the first frame indicating the PTP link information. Based on the first frame indicating the PTP link information, the first STA may decide to switch to the NPCA PCH. For example, if the first STA receives a PPDU indicating / comprising a STA’s IDs in the PTP link information (e.g., the second STA's ID), the first STA may switch to NPCA PCH. If the first STA receives a PPDU indicating / comprising a STA's ID that is not in the PTP link information, the first STA may not switch to the NPCA PCH.

[0176] In combination with the above-described embodiments, an AP (e.g., AP 1302) or STA (e.g., STA 1304, 1306) as described above may further perform one or more of the following operations. Specifically, the AP or STA may perform one or more of the operations associated with NPCA operation as describedDocket No.: 24-3056PCT above. A person of skill in the art, based on the teachings herein, would appreciate that any of the below described operations may be readily combined with the above described embodiments.

[0177] In an implementation, a STA that supports NPCA operation may be called an NPCA STA. An AP that supports NPCA operation may be 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.

[0178] 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.

[0179] 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.

[0180] In an implementation, an NPCA AP with a value (e.g., dotH HEPSROption Implemented) set to true may set the TXVECTOR parameter SPATIAL_REUSE to PSRJDISALLOW for PPDUs that it transmits, and may set the PSR Disallowed subfield in the SR Control field of the Spatial Reuse Parameter Set element to 1 in Management frames it transmits before enabling NPCA operation in its BSS and while NPCA operation remains enabled.

[0181] 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 .

[0182] 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:Docket No.: 24-3056PCT• 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.

[0183] 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.

[0184] 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.

[0185] In an implementation, when a non-AP STA that supports NPCA mode (re)associates with an AP, the NPCA mode may be disabled by default for the non-AP STA. In the UHR OMP request sent to enable or update the parameters of NPCA mode for the non-AP STA, a non-AP STA may include the following in the Mode Parameters field of the Mode Tuple field:NPCA switching delay,NPCA switch back delay.

[0186] 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.

[0187] 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 STADocket No.: 24-3056PCT 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.

[0188] 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.

[0189] 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:1) The value of the MAC variable NPCA_PPDU_REM_DUR derived from the received PPDU is greater than the value indicated in the most recently received or transmitted NPCA Minimum Duration Threshold field corresponding to the BSS of which the STA is a member. ii) If the NPCA AP corresponding to the BSS of which the STA is a member has enabled MOPLEN NPCA in addition to PHYLEN NPCA and the value of the MAC variable NPCA_PHY_TXOP_REM_DUR derived from the received PPDU is greater than the value indicated in the most recently received or transmitted NPCA Minimum Duration Threshold field corresponding to the BSS of which the STA is a member. d) The bandwidth of the PPDU is determined by the STA to be 20, 40, 80 or 160 MHz, based on the Bandwidth field in the PHY preamble of the PPDU and the channel occupied by the PPDU does not overlap with the NPCA primary channel. e) If the STA maintains an intra-BSS NAV, it is zero.2) All of the following conditions are true: a) A sequence of three PPDUs, separated by aSIFSTime, is identified on the BSS primary channel, comprising an initial Control frame, an initial response frame, and a third PPDU following the initial response frame.Docket No.: 24-3056PCT 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. f) The bandwidth of the third PPDU is determined by the STA to be 20, 40, 80, 160 or 320 MHz based on the Bandwidth field in the PHY preamble of the PPDU not overlap with the NPCA primary channel and the channel occupied by the PPDU does not overlap with the NPCA primary channel. g) If the STA maintains an intra-BSS NAV, it is zero at the time of the receipt of the PHYRXSTART.indication and / or the PHY-RXEARLYSIG.indication of the first PPDU.

[0190] 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 valuesDocket No.: 24-3056PCT 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.

[0191] In an implementation, the MAC variable NPCA_PPDU_REM_DUR derived from a received PPDU is equal to the value in usee, of the remaining duration of the received PPDU, determined by the MAC at the time of the receipt of the PHY-RXSTART. indication primitive associated with the received PPDU, by subtracting the time elapsed between the reception of the PHY-CCA.indication(BUSY) and PHY- RXSTART. indication primitives associated with the received PPDU from the value of RXTIME of the received PPDU.

[0192] 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.

[0193] 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 third PPDU of the frame exchange sequence identified in condition 2) above at the time of the receipt of the PHY- RXSTART. indication primitive of the third PPDU.

[0194] 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 readyDocket No.: 24-3056PCT to transmit and receive frames (subject to its capabilities and operating mode) on the NPCA primary channel no later than the value of its most recently indicated NPCA switching delay after the NPCA HE switch time. The NPCA HE switch time is the point in time immediately after the reception of the HE-SIG- A / U-SIG field of the received PPDU from condition 1 ) above.2) If the STA switches from the BSS primary channel to the NPCA primary channel based on meeting condition 2) described above, the STA initiates the switch at the NPCA NHT switch time and shall be ready to transmit and receive frames addressed to it (subject to its capabilities and operating mode) on the NPCA primary channel no later than the value of its most recently indicated NPCA switching delay after the NPCA NHT switch time. The NPCA NHT switch time is equal to the point in time that is 3 x TSYM after the reception of the L-SIG field of the third PPDU of the received sequence of PPDUs from condition 2) above.3) The STA uses the same EDCA parameter set and EPCS EDCA parameter set values for operation on the NPCA primary channel as it uses on the BSS primary channel.4) At each NPCA HE switch time or NPCA NHT switch time, as appropriate, if the STA is an AP or if the STA is a non-AP STA and transmission of frames that are not a response to a Trigger frame is not disabled by the MU EDCA protocol, the STA may initiate a TXOP on the NPCA primary channel with the following exceptions: a) Each time that the STA switches to the NPCA primary channel, the STA does:I) If condition 1) is met, set NPCA_CFRAME_TXOP_REM_DUR to O, set NPCA_TIMER to the largest non-zero value of the variables NPCA_PPDU_REM_DUR, NPCA_PHY_TXOP_REM_DUR and NPCA_CFRAME_TXOP_REM_DUR, minus the switch back delay that the STA indicated in the most recently transmitted NPCA Operation Parameters field.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_NPcA x(CWmin[AC] + 1 ) - 1 . v) invoke the backoff procedure even if the medium for the NPCA primary channel is not busy. vi) initiate countdown of the MAC variable NPCA_TIMER in units of 1 usee.5) A first STA does not initiate a transmission on the NPCA primary channel to a second STA until the NPCA switching delay time of the second STA has elapsed since the NPCA HE switch time at the first STA if the first STA is switching due to condition 1 ) above or since the NPCA NHT switch time at the first STA if the first STA is switching due to condition 2) above.6) The STA begins all frame exchanges on the NPCA primary channel with an initial control frame (ICF) using non-HT PPDU or non-HT duplicate PPDU format using a rate of 6 Mb / s, 12 Mb / s, or 24 Mb / s.Docket No.: 24-3056PCT a) For TXOPs initiated by an AP, the ICF is a BSRP Trigger frame or an MU-RTS Trigger frame except when at least one of the target non-AP STA(s) is operating in the DUO mode, in which case, the ICF may be a BSRP Trigger frame or a BSRP NTB Trigger frame but not an MU-RTS. In addition, the ICF conforms to the rules for Dynamic Unavailability Operation (DUO) mode if at least one of the target non-AP STA(s) is operating in DUO mode, to the rules for Enhanced multi-link single-radio (EMLSR) operation if at least one of the target non-AP STA(s) is affiliated with a non-AP MLD that is operating in EMLSR mode, and to the rules for Dynamic power save (DPS) operation if at least one of the target non-AP STA(s) is operating in DPS mode. b) For TXOPs initiated by a non-AP STA, the initial control frame is a BSRP NTB Trigger frame, except that if the non-AP STA is operating in the Dynamic Unavailability Operation mode (DUO), then the ICF conforms to the DUO mode rules.7) An NPCA AP that transmits a Trigger frame on the NPCA primary channel indicates RU index values that use the NPCA primary channel as the reference primary channel.8) An NPCA STA that transmits a Trigger frame on the NPCA primary channel sets the NPCA Primary Indication field to 1 in the Special User Info field, otherwise, this field is set to 0.9) The 20 MHz channels occupied by PPDUs transmitted by the STA shall meet all of the following conditions: a) include at least the NPCA primary channel. b) all be within the BSS bandwidth. c) not include any of the channels occupied by either the PPDU mentioned in condition 1) or by the third PPDU mentioned in condition 2), whichever caused the STA to switch from the BSS primary channel to the NPCA primary channel. 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.1 1) Dynamic Subband Operation shall not be used on the NPCA primary channel.12) If TBTT for the BSS occurs while an NPCA AP is operating on the NPCA primary channel, the scheduling of the transmission of the Beacon frame and following group addressed frames shall be deferred until immediately after the AP switches back to the BSS primary channel.

[0195] In an example, an AP and associated STAs are not required to switch back to the BSS primary channel at TBTT. The group addressed frames may be buffered and delivered immediately following the next DTIM Beacon, unless explicitly specified otherwise. Further, in an example, exponential backoff may apply on the NPCA primary channel when there are failed transmissions.Docket No.: 24-3056PCT

[0196] In an implementation, an NPCA STA shall switch back to the BSS primary channel when the NPCA_TIMER expires. In an implementation, when the STA switches back to the BSS primary channel, it may:1 ) replace the current values of the variables QSRC[AC], CW[AC] and the backoff counter for each EDCAF with the values that it stored when it switched to the NPCA primary channel.2) resume the backoff procedure.

Claims

Docket No.: 24-3056PCTCLAIMSWhat is claimed is:1 . A method comprising: receiving, by a first station (STA) from an access point (AP), a first frame indicating an identifier (ID) of a second STA, wherein the second STA has a peer-to-peer (PTP) link with a third STA; determining, by the first STA, that: a physical layer protocol data unit (PPDU) being received via a primary channel (PCH) comprises an intra-basic service set (intra-BSS) downlink (DL); and a STA ID field of the PPDU indicates the second ID; and based on the determining, switching, by the first STA, from the PCH to a non-primary channel access (NPCA) PCH.

2. A method comprising: receiving, by a first station (STA) from an access point (AP), a first frame indicating a second STA having a peer-to-peer (PTP) link; determining, by the first STA, that: a physical layer protocol data unit (PPDU) being received via a primary channel (PCH) comprises an intra-basic service set (intra-BSS) downlink (DL) PPDU; and the PPDU indicates the second STA; and based on the determining, switching, by the first STA, from the PCH to a non-primary channel access (NPCA) PCH.

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

4. The method of any of claims 2-3, wherein the first STA has a first identifier (ID).

5. The method of any of claims 2-4, wherein the second STA has a second ID.

6. The method of claims 5, wherein the second STA has the PTP link with a third STA.

7. The method of claim 6, wherein the third STA has a third ID.

8. The method of claim 7, wherein the PPDU comprises a STA ID field comprising the second ID or the third ID.

9. The method of any of claims 6 or 7, wherein the first frame indicates the third STA.

10. The method of any of claims 2-8, wherein the first frame indicates a further STA having a PTP link.11 . The method of claim 5, wherein the second STA has the PTP link with a third STA having a third ID, and wherein the first frame comprises the second ID and the third ID.

12. The method of claim 11 , wherein the first frame comprises a STA ID list comprising the second ID and the third ID.Docket No.: 24-3056PCT13. The method of claim 12, further comprising not switching, by the first STA, from the PCH to the NPCA PCH based on determining that the PPDU comprises a STA ID field set to an identifier that is not in the STA ID list.

14. The method of any of claims 2-12, further comprising detecting ( / receiving), by the first STA, the PPDU comprising the intra-BSS DL PPDU.

15. The method of any of claim 2-14, further comprising communicating, by the first STA, with the AP on the NPCA PCH.

16. The method of claim 15, wherein the communicating, by the first STA, with the AP comprises transmitting, by the first STA to the AP and during a period / duration indicated by the PPDU, a second frame.

17. The method of claim 16, wherein the second frame comprises a control frame, a data frame, or a management frame.

18. The method of claim 15, wherein the communicating, by the first STA, with the AP comprises receiving, by the first STA from the AP during a period / duration indicated by the PPDU, a third frame.

19. The method of claim 18, wherein the third frame comprises a control frame, a data frame, or a management frame.

20. The method of any of claims 2-19, wherein the first frame comprises one of a beacon frame, a traffic indication map (TIM) broadcast frame, a probe response frame, an association response frame, an individually addressed management frame, a group addressed management frame, a control frame, an action frame, a QoS data frame, or a QoS null frame.21 . A method comprising: transmitting, by an access point (AP) to a first station (STA), a first frame indicating a second STA identifier (ID) of a second STA, wherein the second STA has a peer-to-peer (PTP) link with a third STA; determining, by the AP, that a physical layer protocol data unit (PPDU) being received via a primary channel (PCH) comprises an intra-basic service set (intra-BSS) downlink (DL); and based on the determining, switching, by the AP, from the PCH to a non-primary channel access (NPCA) PCH.

22. A method comprising: transmitting, by an access point (AP) to a first station (STA), a first frame indicating a second STA having a peer-to-peer (PTP) link; determining, by the AP, that a physical layer protocol data unit (PPDU) being received via a primary channel (PCH) comprises an intra-basic service set (intra-BSS) downlink (DL) PPDU; and based on the determining, switching, by the AP, from the PCH to a non-primary channel access (NPCA) PCH.

23. The method of claim 22, wherein the first STA is associated with the AP.Docket No.: 24-3056PCT24. The method of any of claims 22-23, wherein the first STA has a first identifier (ID).

25. The method of any of claims 22-24, wherein the second STA has a second ID.

26. The method of claim 25, wherein the second STA has the PTP link with a third STA.

27. The method of claim 26, wherein the third STA has a third ID.

28. The method of claim 27, wherein the PPDU comprises a STA ID field comprising the second ID or the third ID.

29. The method of any of claims 26 or 27, wherein the first frame indicates the third STA.

30. The method of any of claims 22-28, wherein the first frame indicates a further STA having a PTP link.31 . The method of claim 25, wherein the second STA has the PTP link with a third STA, and wherein the first frame comprises the second ID and the third ID.

32. The method of claim 31 , wherein the first frame comprises a STA ID list comprising the second ID and the third ID.

33. The method of claim 32, where the first STA: switches from the PCH to the NPCA PCH based on determining that the PPDU comprises a STA ID field set to an identifier that is in the STA ID list; or does not switch from the PCH to the NPCA PCH based on determining that the PPDU comprises a STA ID field set to an identifier that is not in the STA ID list.

34. The method of any of claims 22-32, further comprising detecting ( / receiving), by the AP, that the PPDU comprises the intra-BSS DL PPDU.

35. The method of any of claim 22-34, further comprising communicating, by the AP, with the first STA on the NPCA PCH.

36. The method of claim 35, wherein the communicating, by the AP, with the first STA comprises transmitting, by the AP to first STA and during a period / duration indicated by the PPDU, a second frame.

37. The method of claim 36, wherein the second frame comprises a control frame, a data frame, or a management frame.

38. The method of claim 35, wherein the communicating, by the AP, with the first STA comprises receiving, by the AP from the first STA during a period / duration indicated by the PPDU, a third frame.

39. The method of claim 38, wherein the third frame comprises a control frame, a data frame, or a management frame.

40. The method of any of claims 22-39, wherein the first frame comprises one of a beacon frame, a traffic indication map (TIM) broadcast frame, a probe response frame, an association response frame, an individually addressed management frame, a group addressed management frame, a control frame, an action frame, a QoS data frame, or a QoS null frame.41 . A device comprising:Docket No.: 24-3056PCT one or more processors; and memory storing instructions that, when executed by the one or more processors, cause the device to perform a method according to any of claims 1-40.

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

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