Station communication during unavailability period

Abstract

An access point (AP) receives from a station (STA) a first frame indicating: adaptive operation or a period of unavailability of the STA due to an in-device coexistence (IDC) event at the STA; and a condition for transmission of a physical layer protocol data unit (PPDU) to the STA while in adaptive operation or during the period of unavailability. The condition may comprise the PPDU having a size / duration smaller than or equal to a threshold, comprising a data frame with a traffic identifier (TID) equal to a first TID, or comprising a frame of a first frame type. The AP transmits to the STA and during the period of unavailability, a first PPDU based on the condition. The AP may receive from the STA a second frame in response to the first PPDU, while the STA is in adaptive operation or during the period of unavailability of the STA.

Description

Docket No.: 24-3035PCTTITLEStation Communication During Unavailability PeriodCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 682,390, filed August 13, 2024, which is hereby incorporated by reference in its entirety.BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0006] FIG. 4 illustrates an example of a Quality of Service (QoS) null frame indicating buffer status information.

[0007] FIG. 5 illustrates an example format of a physical layer (PHY) protocol data unit (PPDU).

[0008] FIG. 6 illustrates an example wireless device.

[0009] FIG. 7 illustrates a procedure in which a transmission opportunity (TXOP) may be adjusted based on a period of unavailability of a STA.

[0010] FIG. 8 illustrates another procedure in which a TXOP may be adjusted based on a period of unavailability of a STA.

[0011] FIG. 9 illustrates an example problem that may arise in the procedures illustrated in FIG. 7 and 8.

[0012] FIG. 10 illustrates an existing procedure that addresses the problem illustrated in FIG. 9.

[0013] FIG. 11 illustrates an example of a procedure according to an embodiment.

[0014] FIG. 12 illustrates another example of a procedure according to an embodiment.

[0015] FIG. 13 illustrates another example of a procedure according to an embodiment.

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

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

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

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

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

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

[0022] FIG. 20 illustrates another example of a procedure according to an embodiment.

[0023] FIG. 21 illustrates another example of a procedure according to an embodiment.

[0024] FIG. 22 illustrates an example process according to an embodiment.Docket No.: 24-3035PCT

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

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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 ,Docket No.: 24-3035PCTSTA2} are: {STA1}, {STA2}, and {STA1 , STA2}. The phrase “based on” (or equally “based at least on’’) is indicative that the phrase following the term “based on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments The phrase “in response to" (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “depending on” (or equally “depending at least to”) is indicative that the phrase following the phrase “depending on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “employing / using" (or equally “employing / using at least”) is indicative that the phrase following the phrase “employing / using” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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 inDocket No.: 24-3035PCT combination with hardware, firmware, wetware (e.g. hardware with a biological element) or a combination thereof, which may be behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab or the like) or a modeling / simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. It may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and / or quantum hardware. Examples of programmable hardware comprise: computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers and microprocessors are programmed using languages such as assembly, C, C++ or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardware description language (VHDL) or Verilog that configure connections between internal hardware modules with lesser functionality on a programmable device. The mentioned technologies are often used in combination to achieve the result of a functional module.

[0034] FIG. 1 illustrates example wireless communication networks in which embodiments of the present disclosure may be implemented.

[0035] 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) 1 10 and 120 and a distribution system (DS) 130.

[0036] 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.

[0037] DS 130 may be configured to connect BSS 110-1 and BSS 110-2. As such, DS 130 may enable an extended service set (ESS) 150. Within ESS 150, APs 104-1 and 104-2 are connected via DS 130and may have the same service set identification (SSID).

[0038] 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.

[0039] 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).Docket No.: 24-3035PCT

[0040] For example, in FIG. 1 , STAs 106-4, 106-5, and 106-6 may be configured to form a first IBSS 112- 1. Similarly, STAs 106-7 and 106-8 may be configured to form a second IBSS 112-2. Since an IBSS does not include an AP, it does not include a centralized management entity. Rather, STAs within an IBSS are managed in a distributed manner. STAs forming an IBSS may be fixed or mobile.

[0041] 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.

[0042] A physical layer (PHY) protocol data unit (PPDU) may be a composite structure that includes a PHY preamble and a payload in the form of a PLOP service data unit (PSDU). For example, the PSDU may include a PHY Convergence Protocol (PLCP) preamble and header and / or one or more MAC protocol data units (MPDUs). The information provided in the PHY preamble may be used by a receiving device to decode the subsequent data in the PSDU. In instances in which PPDUs are transmitted over a bonded channel (channel formed through channel bonding), the preamble fields may be duplicated and transmitted in each of the multiple component channels. The PHY preamble may include both a legacy portion (or "legacy preamble") and a non-legacy portion (or “non-legacy preamble”). The legacy preamble may be used for packet detection, automatic gain control and channel estimation, among other uses. The legacy preamble also may generally be used to maintain compatibility with legacy devices. The format of, coding of, and information provided in the non-legacy portion of the preamble is based on the particular IEEE 802.1 1 protocol to be used to transmit the payload.

[0043] 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 formed through channel bonding. For example, PPDUs may be transmitted over physical channels having bandwidths of 40 MHz, 80 MHz, 160 MHz, or 520 MHz by bonding together multiple 20 MHz channels.

[0044] 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.: 24-3035PCT

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] As shown in FIG. 3, a MAC frame includes a MAC header, a variable length frame body, and a frame check sequence (FCS).

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.: 24-3035PCT 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] The power management subfield is used to indicate the power management mode of a STA.

[0058] 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.

[0059] The protected frame subfield is set to 1 if the frame body field contains information that has been processed by a cryptographic encapsulation algorithm.

[0060] The +HTC subfield indicates that the MAC frame contains an HT control field.

[0061] 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.

[0062] 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.: 24-3035PCT 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.

[0063] 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

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] FIG. 4 illustrates an example of a QoS null frame indicating buffer status information. A QoS null frame refers to a QoS data frame with an empty frame body. A QoS null frame includes a QoS control field and an optional HT control field which may contain a buffer status report (BSR) control subfield. A QoS null frame indicating buffer status information may be transmitted by a STA to an AP.

[0069] The QoS control field may include a traffic identifier (TID) subfield, an ack policy indicator subfield, and a queue size subfield (or a transmission opportunity (TXOP) duration requested subfield).

[0070] The TID subfield identifies the TC or TS of traffic for which a TXOP is being requested, through the setting of the TXOP duration requested or queue size subfield. The encoding of the TID subfield depends on the access policy (e.g., Allowed value 0 to 7 for enhanced distributed channel access (EDCA) access policy to identify user priority for either TC or TS).Docket No.: 24-3035PCT

[0071] The ack policy indicator subfield, together with other information, identifies the acknowledgment policy followed upon delivery of the MPDU (e.g., normal ack, implicit block ack request, no ack, block ack, etc.)

[0072] The queue size subfield is an 8-bit field that indicates the amount of buffered traffic for a given TC or TS at the STA for transmission to the AP identified by the receiver address of the frame containing the subfield. The queue size subfield is present in QoS null frames sent by a STA when bit 4 of the QoS control field is set to 1 . The AP may use information contained in the queue size subfield to determine t TXOP duration assigned to the STA or to determine the uplink (UL) resources assigned to the STA.

[0073] In a frame sent by or to a non-High Efficiency (non-HE) STA, the following rules may apply to the queue size value:The queue size value is the approximate total size, rounded up to the nearest multiple of 256 octets and expressed in units of 256 octets, of all MSDUs and A-MSDUs buffered at the STA (excluding the MSDU or A-MSDU contained in the present QoS Data frame) in the delivery queue used for MSDUs and A-MSDUs with TID values equal to the value indicated in the TID subfield of the QoS Control field.A queue size value of 0 is used solely to indicate the absence of any buffered traffic in the queue used for the specified TID.A queue size value of 254 is used for all sizes greater than 64 768 octets.A queue size value of 255 is used to indicate an unspecified or unknown size.

[0074] In a frame sent by an HE STA to an HE AP, the following rules may apply to the queue size value.

[0075] The queue size value, QS, is the approximate total size in octets, of all MSDUs and A-MSDUs buffered at the STA (including the MSDUs or A-MSDUs contained in the same PSDU as the frame containing the queue size subfield) in the delivery queue used for MSDUs and A-MSDUs with TID values equal to the value indicated in the TID subfield of the QoS control field.

[0076] The queue size subfield includes a scaling factor subfield in bits B14-B15 of the QoS control field and an unsealed value, UV, in bits B8-B13 of the QoS control field. The scaling factor subfield provides the scaling factor, SF.

[0077] A STA obtains the queue size, QS, from a received QoS control field, which contains a scaling factor, SF, and an unsealed value, UV, as follows:QS =16 x(7V, if SF is equal to 0;1024 + 256 * UV, if SF is equal to 1 ;17 408 + 2048 x UV, if SF is equal to 2;148 480 + 32 768 x UV, if SF is equal to 3 and V is less than 62;> 2 147 328, if SF equal to is 3 and V is equal to 62;Unspecified or Unknown, if SF is equal to 3 and UV is equal to 63.Docket No.: 24-3035PCT

[0078] The TXOP duration requested subfield, which may be included instead of the queue size subfield, indicates the duration, in units of 32 microseconds (us), that the sending STA determines it needs for its next TXOP for the specified TID. The TXOP duration requested subfield is set to 0 to indicate that no TXOP is requested for the specified TID in the current service period (SP). The TXOP duration requested subfield is set to a nonzero value to indicate a requested TXOP duration in the range of 32 us to 8160 us in increments of 32 us.

[0079] The HT control field may include a BSR control subfield which may contain buffer status information used for UL MU operation. The BSR control subfield may be formed from an access category index (ACI) bitmap subfield, a delta TID subfield, an ACI high subfield, a scaling factor subfield, a queue size high subfield, and a queue size all subfield of the HT control field.

[0080] The ACI bitmap subfield indicates the access categories (ACs) for which buffer status is reported (e.g., B0: best effort (AC_BE), B1 : background (AC_BK), B2: video (AC_VI), B3: voice (AC_VO), etc.). Each bit of the ACI bitmap subfield is set to 1 to indicate that the buffer status of the corresponding AC is included in the queue size all subfield, and set to 0 otherwise, except that if the ACI bitmap subfield is 0 and the delta TID subfield is 3, then the buffer status of all 8 TIDs is included.

[0081] The delta TID subfield, together with the values of the ACI bitmap subfield, indicate the number of TIDs for which the STA is reporting the buffer status.

[0082] The ACI high subfield indicates the ACI of the AC for which the BSR is indicated in the queue size high subfield. The ACI to AC mapping is defined as ACI value 0 mapping to AC_BE, ACI value 1 mapping to AC_BK, ACI value 2 mapping to AC_VI , and ACI value 3 mapping to AC_VO.

[0083] The scaling factor subfield indicates the unit SF, in octets, of the queue size high and queue size all subfields.

[0084] The queue size high subfield indicates the amount of buffered traffic, in units of SF octets, for the AC identified by the ACI high subfield, that is intended for the STA identified by the receiver address of the frame containing the BSR control subfield.

[0085] The queue size all subfield indicates the amount of buffered traffic, in units of SF octets, for all ACs identified by the ACI Bitmap subfield, that is intended for the STA identified by the receiver address of the frame containing the BSR control subfield.

[0086] The queue size values in the queue size high and queue size all subfields are the total sizes, rounded up to the nearest multiple of SF octets, of all MSDUs and A-MSDUs buffered at the STA (including the MSDUs or A-MSDUs contained in the same PSDU as the frame containing the BSR control subfield) in delivery queues used for MSDUs and A-MSDUs associated with AC(s) that are specified in the ACI high and ACI bitmap subfields, respectively.

[0087] A queue size value of 254 in the queue size high and queue size all subfields indicates that the amount of buffered traffic is greater than 254 x SF octets. A queue size value of 255 in the queue size highDocket No.: 24-3035PCT and queue size all subfields indicates that the amount of buffered traffic is an unspecified or unknown size. The queue size value of QoS data frames containing fragments may remain constant even if the amount of queued traffic changes as successive fragments are transmitted.

[0088] MAC service provides peer entities with the ability to exchange MSDUs. To support this service, a local MAC uses the underlying PHY-level service to transport the MSDUs to a peer MAC entity. Such asynchronous MSDU transport is performed on a connectionless basis.

[0089] FIG. 5 illustrates an example format of a PPDU. As shown, the PPDU may include a PHY preamble, a PHY header, a PSDU, and tail and padding bits.

[0090] The PSDU may include one or more MPDUs, such as a QoS data frame, an MMPDU, a MAC control frame, or a QoS null frame. In the case of an MPDU carrying a QoS data frame, the frame body of the MPDU may include a MSDU or an A-MSDU.

[0091] By default, MSDU transport is on a best-effort basis. That is, there is no guarantee that a transmitted MSDU will be delivered successfully. However, the QoS facility uses a traffic identifier (TID) to specify differentiated services on a per-MSDU basis.

[0092] A STA may differentiate MSDU delivery according to designated traffic category (T C) or traffic stream (TS) of individual MSDUs. The MAC sublayer entities determine a user priority (UP) for an MSDU based on a TID value provided with the MSDU. The QoS facility supports eight UP values. The UP values range from 0 to 7 and form an ordered sequence of priorities, with 1 being the lowest value, 7 the highest value, and 0 falling between 2 and 3.

[0093] An MSDU with a particular UP is said to belong to a traffic category with that UP. The UP may be provided with each MSDU at the medium access control service access point (MAC SAP) directly in a UP parameter. An A-MPDU may include MPDUs with different TID values.

[0094] A STA may deliver buffer status reports (BSRs) to assist an AP in allocating UL MU resources. The STA may either implicitly deliver BSRs in the QoS control field or BSR control subfield of any frame transmitted to the AP (unsolicited BSR) or explicitly deliver BSRs in a frame sent to the AP in response to a BSRP Trigger frame (solicited BSR).

[0095] The buffer status reported in the QoS control field includes a queue size value for a given TID. The buffer status reported in the BSR control field includes an ACI bitmap, delta TID, a high priority AC, and two queue sizes.

[0096] A STA may report buffer status to the AP, in the QoS control field, of transmitted QoS null frames and QoS data frames and, in the BSR control subfield (if present), of transmitted QoS null frames, QoS data frames, and management frames as defined below.

[0097] The STA may report the queue size for a given TID in the queue size subfield of the QoS control field of transmitted QoS data frames or QoS null frames; the STA may set the queue size subfield to 255 toDocket No.: 24-3035PCT indicate an unknown / unspecified queue size for that TID. The STA may aggregate multiple QoS data frames or QoS null frames in an A-MPDU to report the queue size for different TIDs.

[0098] The STA may report buffer status in the BSR control subfield of transmitted frames if the AP has indicated its support for receiving the BSR control subfield.

[0099] A High-Efficiency (HE) STA may report the queue size for a preferred AC, indicated by the ACI high subfield, in the queue size high subfield of the BSR control subfield. The STA may set the queue size high subfield to 255 to indicate an unknown / unspecified queue size for that AC.

[0100] A HE STA may report the queue size for ACs indicated by the ACI bitmap subfield in the queue size all subfield of the BSR control subfield. The STA may set the queue size all subfield to 255 to indicate an unknown / unspecified BSR for those ACs.

[0101] FIG. 6 illustrates an example wireless device 600. Wireless device 600 may support a plurality of radio technologies, including wireless local area network (WLAN) (e.g., IEEE 802.1 1 Wi-Fi®), Bluetooth®, ultra-wideband (UWB), and long-term evolution (LTE) / 5G, for example. As such, as shown in FIG. 6, wireless device 600 may comprise a plurality of radio modules, including a WLAN radio module 602, a Bluetooth® radio module 604, a UWB radio module 606, and an LTE / 5G radio module 608, for example. Each radio module of radio modules 602, 604, 606, and 608 may comprise a baseband processor and radio frequency (RF) circuitry for the respective radio technology supported by the radio module. Radio modules 602, 604, 606, and 608 may be coupled respectively to antennas 610, 612, 614, and 616.

[0102] Wireless device 600 may comprise or operate as a non-AP STA or an AP STA. Wireless device 600 may be, for example, an embodiment of STA 210 or AP 260 illustrated in FIG. 2. In operation, radio modules 602, 604, 606, and 608 may interfere with each other. For example, a transmission by WLAN radio module 602 may interfere with a reception by Bluetooth® radio module 604, UWB radio module 606, and / or LTE / 5G radio module 608. Alternatively, a transmission by Bluetooth® radio module 604, UWB radio module 606, or LTE / 5G radio module 608 may interfere with a reception by WLAN module 602. Such interference events may be referred to as in-device coexistence (IDC) interference events.

[0103] To reduce IDC interference events, wireless device 600 may be configured to avoid transmitting using a first radio module when the transmission using the first radio module is expected to or is likely to interfere with the reception using one or more second radio modules of wireless device 600. Alternatively, or additionally, wireless device 600 may be configured to avoid receiving using the first radio module when transmission using the one or more second radio modules is expected to or is likely to interfere with the reception using the first radio module. For example, wireless device 600 may be configured to avoid transmitting using a WLAN module 602 when the transmission using WLAN module 602 is expected to or is likely to interfere with the reception using Bluetooth® radio module 604, UWB radio module 606, and / or LTE / 5G radio module 608 of wireless device 600. Alternatively, or additionally, wireless device 600 may be configured to avoid receiving using WLAN module 602 when transmission using Bluetooth® radio moduleDocket No.: 24-3035PCT604, UWB radio module 606, and / or LTE / 5G radio module 608 is expected to or is likely to interfere with the reception using WLAN module 602.

[0104] When wireless device 600 operates as a non-AP STA or an AP STA, the time periods during which wireless device 600 may avoid transmitting and / or receiving using WLAN module 602 (to avoid the occurrence of IDC interference events) may correspond to periods of unavailability for the non-AP STA or the AP STA. That is, the non-AP STA or the AP STA embodied by wireless device 600 may be unavailable to communicate with other WLAN devices (e.g., a peer non-AP STA(s) or an AP STA(s)) during those time periods.

[0105] FIG. 7 illustrates an example 700 of a procedure in which a transmission opportunity (TXOP) may be adjusted based on a period of unavailability of a STA. As shown in FIG. 7, example 700 includes a STA 702 and a STA 704. STAs 702 and 704 may each be a non-AP STA or an AP STA. In an example, STA 702 may be an AP STA and STA 704 may be a non-AP STA. In an example, STA 704 may be associated with STA 702.

[0106] Example 700 may begin with STA 702 transmitting an initial control frame (ICF) 706 to STA 704. IGF 706 may be a control frame, such as a request-to-send (RTS) frame, for example. ICF 706 may indicate a first transmission opportunity (TXOP). In an implementation, a duration of the first TXOP may be indicated in a duration field of ICF 706. ICF 706 may reserve the wireless medium for the duration of the first TXOP.

[0107] On receiving ICF 706, STA 704 may determine that STA 702 intends to communicate with STA 704 during the first TXOP. STA 704 may further determine that the first TXOP overlaps with a period of unavailability of STA 704. The period of unavailability may be due to an IDC event within STA 704. STA 704 may be unavailable for communication with other WLAN devices, including STA 702, during the period of unavailability to avoid the occurrence of an IDC interference event due to the IDC event.

[0108] In response to ICF 706, STA 704 may transmit to STA 702 an initial control response (ICR) 708 that indicates a second TXOP that does not overlap with the period of unavailability of STA 704. ICR 708 may be a control frame, such as a clear-to-send (CTS) frame, for example. In an implementation, ICR 708 may include information regarding the period of unavailability of STA 704. In an implementation, the second TXOP may be set to a shorter value than a value indicated in the first TXOP. In this case, as shown in FIG. 7, the end time of the second TXOP may end earlier than the end time of the first TXOP. casein another implementation (not shown in FIG. 7), the end time of the second TXOP may be equal to the end time of the first TXOP. In an implementation, a duration of the second TXOP may be indicated in a duration field of ICR 708. In another implementation, a duration of the second TXOP may be indicated in another field than a duration field of ICR 708. The other field may be a new field or an existing field of ICR 708. In another implementation, a duration of the second TXOP may be indicated in a duration field of ICR 708 and the period of unavailability of STA 704 may be indicated in another field of ICR 708. In this case, the end time of theDocket No.: 24-3035PCT second TXOP may be equal to the end time of the first TXOP. The other field may be a new field or an existing field of ICR 708.

[0109] On receiving ICR 708, STA 702 may initiate transmission of a data frame 710 to STA 704. Data frame 710 may indicate a third TXOP based on the second TXOP indicated in ICR 708. In an implementation, an end time of the third TXOP may be equal to an end time of the second TXOP as shown in FIG. 7. As such, the third TXOP avoids the period of unavailability of STA 704, and communication between STA 702 and STA 704 can end before a start of the period of unavailability of STA 704. In another implementation, an end time of the second TXOP may be equal to an end time of the first TXOP. In this case, an end time of the third TXOP may be different from (e.g., shorter than) an end time of the second TXOP (not shown in FIG. 7). As such, the third TXOP avoids the period of unavailability of STA 704, and communication between STA 702 and STA 704 can end before a start of the period of unavailability of STA 704.

[0110] STA 704 may respond to data frame 710 by transmitting to STA 702 a BlockAck (BA) frame 712 marking the end of the third TXOP. Subsequently, the period of unavailability begins at STA 704, and STA 704 becomes unavailable for communication. In an implementation, based on receiving the information regarding the period of unavailability of STA 704 in ICR 708, STA 702 may refrain from any transmission to STA 704 during the period of unavailability of STA 704. In an implementation, after receiving BA frame 712, STA 702 may transmit a CF-End frame (not shown in FIG. 7).

[0111] FIG. 8 illustrates an example 800 of another procedure in which a TXOP may be adjusted based on a period of unavailability of a STA. As shown in FIG. 8, example 800 includes a STA 802 and a STA 804. STAs 802 and 804 may each be a non-AP STA or an AP STA. In an example, STA 802 may be an AP STA and STA 804 may be a non-AP STA. In an example, STA 804 may be associated with STA 802.

[0112] Example 800 may begin with STA 804 transmitting to STA 802 a frame 814 indicating a period of unavailability of STA 804. The period of unavailability may be due to an IDC event within STA 804. STA 804 may be unavailable for communication with other WLAN devices, including STA 802, during the period of unavailability to avoid the occurrence of an IDC interference event due to the IDC event. Frame 814 may be a data frame, a control frame, a management frame, or an action frame, for example.

[0113] Subsequently, STA 802 may transmit an ICF 806 to STA 804. ICF 806 may be a control frame, such as an RTS frame, for example. ICF 806 may be a management frame, a data frame, or a QoS null frame. ICF 806 may indicate a first TXOP. Based on the information regarding the period of unavailability of STA 804 received in frame 814, STA 802 may be configured to set the first TXOP so as not overlap with the period of unavailability of STA 804. For example, as shown in FIG. 8, STA 802 may be configured to set the first TXOP to end before a start of the period of unavailability of STA 804. In an implementation, a duration of the first TXOP may be indicated in a duration field of ICF 806. ICF 806 may reserve the wireless medium for the duration of the first TXOP.Docket No.: 24-3035PCT

[0114] On receiving ICF 806, STA 804 may determine that STA 802 intends to communicate with STA 804 during the first TXOP. STA 804 may further determine that the first TXOP does not overlap with the period of unavailability of STA 804. In response to ICF 806, STA 804 may transmit to STA 802 an ICR 808 that indicates a second TXOP based on the first TXOP. In an implementation, an end time of the second TXOP is equal to an end time of the first TXOP. ICR 808 may be a control frame, such as a CTS frame, for example.

[0115] On receiving ICR 808, STA 802 may initiate transmission of a data frame 810 to STA 804. Data frame 810 may indicate a third TXOP based on the second TXOP indicated in ICR 808. In an implementation, an end time of the third TXOP is equal to an end time of the second TXOP. The third TXOP avoids the period of unavailability of STA 804, and communication between STA 802 and STA 804 can end before a start of the period of unavailability of STA 804.

[0116] STA 804 may respond to data frame 810 by transmitting to STA 802 a BA frame 812 marking the end of the third TXOP. Subsequently, the period of unavailability begins at STA 804, and STA 804 becomes unavailable for communication. Based on receiving the information regarding the period of unavailability of STA 804 in frame 814, STA 802 may refrain from any transmission to STA 804 during the period of unavailability of STA 804.

[0117] FIG. 9 shows an example 900 that illustrates a problem that may arise in the procedure illustrated in FIG. 8. As shown in FIG. 9, example 900 may also begin with the transmission of STA 804 to STA 802 of frame 814, followed by the exchange of ICF 806 and ICR 808, the transmission of STA 802 to STA 804 of data frame 810, and the response of STA 804 to STA 802 with BA frame 812.

[0118] Subsequently, after the period of unavailability begins at STA 804, data for STA 804 arrives at STA 802 In an example, the data may be low latency (LL) data that requires urgent transmission to STA 804. However, as STA 802 is configured to refrain from any transmission to STA 804 during the period of unavailability of STA 804 (in accordance with the procedure of FIG. 8), STA 802 may only buffer the arriving data for STA 802 and may only transmit the data after the end of the period of unavailability of STA 804, e.g ., in a data frame 902.

[0119] However, in some cases, an actual period of unavailability of STA 804 may be shorter than the period of unavailability of STA 804 announced / indicated in frame 814. For example, the actual period of unavailability of STA 804 may start later than or may end before the announced / indicated period of unavailability of STA 804. In a particular example (as shown in example 900), the announced / indicated period of unavailability of STA 804 may be to avoid an IDC interference event within STA 804, and an actual duration of the IDC event (during which STA 804 is effectively unavailable for communication) may be shorter than the announced / indicated period of unavailability of STA 804. For instance, the IDC event may end before the announced / indicated period of unavailability of STA 804 or may even be cancelled before the start of the announced / indicated period of unavailability of STA 804. Nevertheless, despite that STA 804 becomes available before the end of the announced / indicated period of unavailability of STA 804, STA 802 may onlyDocket No.: 24-3035PCT transmit the data buffered for STA 802 after the end of the announced / indicated period of unavailability of STA 804. This may result in the transmission of the data to STA 804 being unnecessarily delayed, and, in the case of LL data, may cause the data to be discarded and lost at STA 802.

[0120] An existing solution to the above-described problem, illustrated in example 1000 of FIG. 10, proposes that STA 802 transmit a probe frame 1002 to STA 804, during the period of unavailability of STA 804, when STA 802 has buffered traffic for STA 804. Probe frame 1002 may probe whether STA 804 is available for communication. Probe frame 1002 may further indicate that STA 802 has buffered traffic for STA 804. If the period of unavailability of STA 804 has ended when STA 802 transmits probe frame 1002 (not shown in FIG. 10), STA 804 may receive probe frame 1002 and may respond to probe frame 1002 by transmitting to STA 802 a frame indicating that the period of unavailability ended or an immediate response frame. Otherwise, if the period of unavailability of STA 804 has not ended when STA 802 transmits probe frame 1002 (as shown in FIG. 10), STA 804 may not receive probe frame 1002 and may not respond to probe frame 1002. After waiting a first time delay, STA 802 may transmit a subsequent probe frame 1004 to STA 804. In example 1000, STA 802 transmits probe frame 1004 to STA 804 after the actual period of unavailability of STA 804 has ended. STA 804 thus receives probe frame 1004 and responds to probe frame 1004 by transmitting a frame 1006 to STA 802. Frame 1006 may be a frame that indicates that the period of unavailability ended or an immediate response frame. On receiving frame 1006, STA 802 may transmit to STA 804 a frame 1008. Frame 1008 may be a data frame that comprises the data buffered for STA 804. STA 804 may respond to frame 1008 by transmitting a frame 1010 to STA 802. Frame 1010 may comprise a BA frame.

[0121] As illustrated in example 1000, the solution of FIG. 10 allows STA 802 to transmit the data buffered for STA 804 without waiting for an end of the indicated period of unavailability of STA 802 when STA 804 becomes available before the end of the indicated period of unavailability. As such, STA 804 can receive the buffered data in a relatively short time after its arrival at STA 802. This may prevent the buffered data from being discarded when the buffered data includes LL data. However, as described above, in some cases, STA 802 may transmit probe frame 1002 to STA 804 before STA 804 has become available. For example, STA 802 may transmit probe frame 1002 while STA 804 is unavailable due to an ongoing communication event of another RAT (IDC event) at STA 804. The transmission of probe frame 1002 may thus interfere with the IDC event and may result in an IDC interference event at STA 804. Such an IDC interference event may be even less tolerable when STA 802 has only non-LL data buffered for transmission to STA 804.

[0122] Embodiments of the present disclosure, as further described below, address the above-described problems of existing technologies. In an aspect, a first STA transmits to a second STA a first frame indicating: a period of unavailability (or limited / reduced / adaptive availability / operation) of the first STA; and a condition (or modified parameter) for transmission of a PPDU by the second STA to the first STA during the period of unavailability (or while the first STA is in limited / reduced / adaptive availability / operation). In an embodiment, the condition comprises the PPDU comprising a data frame with a traffic identifier (TID) equal to a first TIDDocket No.: 24-3035PCT or with an access category (AC) equal to a first AC. In another embodiment, the condition comprises the PPDU having a size / duration lower than or equal to a threshold. In a further embodiment, the condition comprises the PPDU comprising a frame of a first frame type. In an embodiment, when the first frame indicates a condition (or modified parameter) for transmission of a PPDU during a period of unavailability of the first STA, the period of unavailability may be equivalent to, and may be referred to as, a period of limited / reduced / adaptive availability / operation of the first STA. The first frame may indicate limited / reduced / adaptive availability / operation of the first STA or a period of limited / reduced / adaptive availability / operation of the first STA. The first STA receives from the second STA, during the period of unavailability (or while the first STA is in limited / reduced / adaptive availability / operation), a first PPDU based on the condition. As such, transmissions to the first STA during the period of unavailability (or while the first STA is in limited / reduced / adaptive availability / operation) may be reduced to transmissions for which the first STA may tolerate an IDC interference event if such an IDC interference event were to occur. Such transmissions may include, for example, urgent transmissions, higher priority transmission, and / or transmissions with a lower potential interference impact at the first STA.

[0123] FIG. 11 illustrates an example 1100 of a procedure according to an embodiment. Example 1 100 is provided for the purpose of illustration only and is not limiting of embodiments. As shown in FIG. 11 , example 1100 includes a STA 1102 and a STA 1 104. STA 1 102 may be an AP STA or a non-AP STA. Similarly, STA 1104 may be an AP STA or a non-AP STA. In an embodiment, STA 1102 may be an AP STA, and STA 1104 may be a non-AP STA. STA 1 104 may be associated with STA 1 102. In another embodiment, STA 1102 may be a non-AP STA, and STA 1104 may be an AP STA. STA 1102 may be associated with STA 1104.

[0124] As shown in FIG. 11 , example 1100 may begin with STA 1104 transmitting a frame 1 106 to STA 1 102. In embodiments, frame 1106 may comprise an initial control frame (ICF), an initial control response frame (ICR), a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame, for example. In an embodiment, frame 1 106 comprises an ICR transmitted by STA 1 104 in response to an ICF frame from STA 1102. In an embodiment, the ICR transmitted by STA 1 104 comprises a multi-STA BlockAck frame, and the ICF transmitted by STA 1102 comprises a BSRP Trigger frame. In an embodiment, STA 1102 transmits the ICF to initiate frame exchanges (that are neither group addressed Data nor group address Management frames) with STA 1104 when STA 1 104 operates in a mode in which STA 1104 may inform another STA of its limited / reduced / adaptive availability / operation (e g., Dynamic Unavailability Operation (DUO) mode, Periodic Unavailability Operation (PUO) mode, or Limited Operation Mode (LOM)). LOM may also be referred to as Adaptive Operation Mode (AOM). In LOM / AOM, a STA may reduce / adapt (or may request from an associated AP to reduce / adapt) parameters / conditions used for communication (transmission / reception) with the STA. In another embodiment, where STA 1 104 is a TXOP holder, frame 1 106 comprises a BSRP Trigger frame.Docket No.: 24-3035PCT

[0125] In an embodiment, frame 1 106 may indicate a period of unavailability of (or limited / reduced / adaptive availability / operation) STA 1104. The period of unavailability (or limited / reduced / adaptive availability / operation) may be periodic or aperiodic. The period of unavailability may be due to an IDC event within STA 1104. STA 1104 may be unavailable for communication with other WLAN devices, including STA 1102, during at least a portion of the period of unavailability (or while in limited / reduced / adaptive availability / operation) to avoid the occurrence of an IDC interference event due to the IDC event. As described above, the duration of the IDC event may be shorter than the period of unavailability indicated in frame 1106. For example, the IDC event may end before the end of the period of unavailability indicated in frame 1 106. In an embodiment, frame 1106 indicates a target start time and a duration for the period of unavailability.

[0126] In an embodiment, frame 1 106 further indicates a condition for transmission of a PPDU by STA 1102 to STA 1104 during the period of unavailability (or while STA 1104 is in limited / reduced / adaptive availability / operation) of STA 1 104. In other words, frame 1106 indicates that, notwithstanding the indicated period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1 104, a PPDU may be transmitted to STA 1 104, during the period of unavailability (or while STA 1 104 is in limited / reduced / adaptive availability / operation), provided that the PPDU satisfies the condition indicated in frame 1 106.

[0127] In an embodiment, as illustrated in FIG. 1 1 , the condition comprises the PPDU comprising a data frame with a TID equal to one of one or more first TIDs (e.g., x, y, z) and / or with an access category (AC) equal to one of one or more first ACs (e.g., AC_VO, AC_VI). The one or more first TIDs and / or the one or more first ACs may correspond to traffic that STA 1104 wishes to receive during the period of unavailability (or while in limited / reduced / adaptive availability / operation). In an embodiment, the one or more first TIDs comprise a first TID that corresponds to low-latency traffic or to urgent traffic. In an embodiment, frame 1106 may comprise one or more first fields that indicate the one or more first TIDs and / or the one or more first ACs. In an embodiment, the one or more first fields comprise a first field that indicates the one or more first TIDs. In an embodiment, the first field may comprise a TID bitmap with a respective bit for each downlink TID of STA 1104. In an implementation, the respective bit for a TID may be set to 1 in the TID bitmap to indicate that a PPDU comprising a data frame with the TID (i.e., a data frame comprising traffic associated with the TID) may be transmitted to STA 1104 during the period of unavailability of STA 1104. In an implementation, the respective bit for a TID may be set to 0 in the TID bitmap to indicate that a PPDU comprising a data frame with the TID may not be transmitted to STA 1104 during the period of unavailability of STA 1104 (or while STA 1104 is in limited / reduced / adaptive availability / operation). In another embodiment, the one or more first fields comprise a first field that indicates the one or more first ACs. In an embodiment, the first field may comprise an AC bitmap with a respective bit for each AC of AC_VO, AC_VI, AC_BE, or AC_BK. In an implementation, the respective bit for an AC may be set to 1 in the AC bitmap to indicate that a PPDU comprising a data frame with the AC (i.e., a data frame comprising traffic associated with the AC) may be transmitted to STA 1104 during the period of unavailability of STA 1104. In an implementation, the respectiveDocket No.: 24-3035PCT bit for an AC may be set to 0 in the AC bitmap to indicate that a PPDU comprising a data frame with the AC may not be transmitted to STA 1104 during the period of unavailability of STA 1104 (or while STA 1 104 is in limited / reduced / adaptive availability / operation).

[0128] In an embodiment, based on receiving frame 1 106, STA 1102 may be configured to refrain from transmitting to STA 1104, during the period of unavailability of STA 1 104 (or while STA 1104 is in limited / reduced / adaptive availability / operation), any PPDU that does not satisfy the condition indicated in frame 1 106. Specifically, in example 1100, STA 1 102 may be configured to refrain from transmitting to STA 1104, during the period of unavailability of STA 1104 (or while STA 1104 is in limited / reduced / adaptive availability / operation), any PPDU that does not comprise a data frame with a TID equal to the one of one or more first TIDs (e.g., x, y, z) and / or with an AC equal to the one of one or more first ACs (e.g., AC_VO, AC_VI).

[0129] Returning to FIG. 1 1 , in an example, after transmitting frame 1106, STA 1104 may exchange one or more frames (not shown in FIG. 11 ) with STA 1102. For example, STA 1104 may communicate with STA 1102 to transmit and / or receive data to / from STA 1102.

[0130] Subsequently, the period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1104 begins. In example 1100, after the period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1 104 begins, data for STA 1104 with a TID equal to TID x arrives at STA 1 102. For example, TID x may correspond to low latency (LL) traffic that requires urgent transmission to STA 1104. Based on TID x being among the one or more first TIDs indicated in the condition indicated in frame 1 106, STA 1102 may transmit to STA 1104 during the period of unavailability of STA 1104 (or while STA 1104 is in limited / reduced / adaptive availability / operation) a PPDU 1 108 comprising a data frame with at least a portion of the data with the TID equal to TID x.

[0131] In embodiments, as illustrated in FIGs. 12, 13, and 14, STA 1104 may transmit to STA 1 102 a frame, during the period of unavailability of STA 1 104 (or while STA 1 104 is in limited / reduced / adaptive availability / operation), in response to PPDU 1 108. The frame transmitted by STA 1 104 in response to PPDU 1108 may indicate whether STA 1 104 is available to communicate with STA 1 102. In embodiments, the frame transmitted by STA 1104 in response to PPDU 1108 may comprise a PS-Poll frame, an ICF, an ICR, a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame, for example. In an embodiment, the frame transmitted by STA 1 104 in response to PPDU 1108 may be an immediate response frame, such an acknowledgement (Ack) or a BA frame The immediate response frame may be transmitted by STA 1104 a short interframe space (SIFS) after receiving PPDU 1 108. The immediate response frame may indicate a reception status of the data comprised in PPDU 1108.

[0132] In an embodiment, as shown in example 1200 of FIG. 12, STA 1104 transmits a frame 1202 in response to PPDU 1 108 before an end of the IDC event at STA 1104. In an implementation, frame 1202 mayDocket No.: 24-3035PCT be an immediate response frame, such as an Ack or BA frame. Frame 1202 may indicate a reception status of the data comprised in PPDU 1108 and / or whether STA 1104 has become available for communication. In an implementation, STA 1104 may transmit frame 1202 without performing a random backoff procedure to access the channel. In an implementation, STA 1104 may transmit frame 1202 a SIPS after PPDU 1 108.

[0133] In another embodiment, as shown in example 1300 of FIG. 13, STA 1104 transmits a frame 1302 in response to PPDU 1108 after an end of the IDC event at STA 1 104. In embodiments, frame 1302 may comprise a PS-Poll frame, an ICF, an ICR, a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame, for example. Frame 1302 may indicate a reception status of the data comprised in PPDU 1 108 and / or whether STA 1 104 has become available for communication. In an implementation, STA 1104 may transmit frame 1302 after performing a random backoff procedure to access the channel.

[0134] In a further embodiment, as shown in example 1400 of FIG. 14, STA 1 104 transmits a frame 1404 in response to PPDU 1108 after receiving a frame 1402 from STA 1102 that solicits frame 1404. In an implementation, frame 1404 may be an Ack or BA frame. In an implementation, frame 1402 may be a BA request (BAR) frame. Frame 1404 may indicate a reception status of the data comprised in PPDU 1 108 and / or whether STA 1104 has become available for communication. In an implementation, STA 1104 may transmit frame 1404 without performing a random backoff procedure to access the channel.

[0135] FIG. 15 illustrates an example 1500 of another procedure according to an embodiment. Example 1500 is provided for the purpose of illustration only and is not limiting of embodiments. As shown in FIG. 15, example 1500 includes a STA 1502 and a STA 1504. STA 1502 may be an AP STA or a non-AP STA. Similarly, STA 1504 may be an AP STA or a non-AP STA. In an embodiment, STA 1502 may be an AP STA, and STA 1504 may be a non-AP STA. STA 1504 may be associated with STA 1502. In another embodiment, STA 1502 may be a non-AP STA, and STA 1504 may be an AP STA. STA 1502 may be associated with STA 1504.

[0136] As shown in FIG. 15, example 1500 may begin with STA 1504 transmitting a frame 1506 to STA 1502. In embodiments, frame 1506 may comprise an ICF, an ICR, a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame, for example. In an embodiment, frame 1506 comprises an ICR transmitted by STA 1504 in response to an ICF frame from STA 1502. In an embodiment, the ICR transmitted by STA 1504 comprises a multi-STA BlockAck frame, and the ICF transmitted by STA 1502 comprises a BSRP Trigger frame. In an embodiment, STA 1502 transmits the ICF to initiate frame exchanges (that are neither group addressed Data nor group address Management frames) with STA 1504 when STA 1504 operates in a mode in which STA 1504 may inform another STA of its limited / reduced / adaptive availability / operation (e.g., Dynamic Unavailability Operation (DUO) mode, Periodic Unavailability Operation (PUO) mode, or Limited Operation Mode (LOM)). LOM may also be referred to as Adaptive Operation Mode (AOM). In LOM / AOM, a STA may reduce / adapt (or may request from anDocket No.: 24-3035PCT associated AP to reduce / adapt) parameters / conditions used for communication (transmission / reception) with the STA. In another embodiment, where STA 1504 is a TXOP holder, frame 1506 comprises a BSRP Trigger frame.

[0137] In an embodiment, frame 1506 may indicate a period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1504. The period of unavailability (or limited / reduced / adaptive availability / operation) may be periodic or aperiodic. The period of unavailability (or limited / reduced / adaptive availability / operation) may be due to an IDC event within STA 1504. STA 1504 may be unavailable for communication with other WLAN devices, including STA 1502, during at least a portion of the period of unavailability (or while in limited / reduced / adaptive availability / operation) to avoid the occurrence of an IDC interference event due to the IDC event. As described above, the duration of the IDC event may be shorter than the period of unavailability indicated in frame 1506. For example, the IDC event may end before the end of the period of unavailability indicated in frame 1506. In an embodiment, frame 1506 indicates an unavailability target start time and an unavailability duration.

[0138] In an embodiment, frame 1506 further indicates a condition for transmission of a PPDU to STA 1504 during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation). In other words, frame 1506 indicates that, notwithstanding the indicated period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1504, a PPDU may be transmitted by STA 1502 to STA 1504, during the period of unavailability (or while STA 1504 is in limited / reduced / adaptive availability / operation), provided that the PPDU satisfies the condition indicated in frame 1506.

[0139] In an embodiment, as illustrated in FIG. 15, the condition comprises the PPDU having a size / d urati on smaller than or equal to a threshold (or a maximum PPDU size / duration) (e.g., X). In an embodiment, frame 1506 may include a field indicating the threshold (or the maximum PPDU size / duration).

[0140] In an embodiment, based on receiving frame 1506, STA 1502 may be configured to refrain from transmitting to STA 1504, during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation), any PPDU that does not satisfy the condition indicated in frame 1506. Specifically, in example 1500, STA 1502 may be configured to refrain from transmitting to STA 1504, during the period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1504, any PPDU that is larger than the threshold (or maximum PPDU size / duration) X indicated in frame 1506. In an embodiment, STA 1502 may be configured to apply this behavior as long as STA 1502 has not received from STA 1504 a frame indicating the availability of STA 1504.

[0141] Returning to FIG. 15, in an example, after transmitting frame 1506, STA 1504 may exchange one or more frames (not shown in FIG. 15) with STA 1502. For example, STA 1504 may communicate with STA 1502 to transmit and / or receive data to / from STA 1502.Docket No.: 24-3035PCT

[0142] Subsequently, the period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1504 begins. In example 1500, after the period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1504 begins, data for STA 1504 arrives at STA 1502. In an embodiment, STA 1502 may buffer the data for transmission to STA 1504. In an embodiment, STA 1502 may determine whether the buffered data can be transmitted in a PPDU with a size / duration smaller than or equal to the threshold X indicated in frame 1506.

[0143] In an embodiment, STA 1502 may be configured, if the buffered data can be transmitted (in its entirety) in a PPDU with a size / duration smaller than or equal to the threshold X, to transmit a PPDU with the buffered data to STA 1504 during the period of unavailability (or while STA 1504 is in limited / reduced / adaptive availability / operation). This is illustrated in example 1500, in which the size / duration of the buffered data for STA 1504 is smaller than or equal to the threshold X and in which STA 1502 transmits the buffered data, during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation), in a PPDU 1508 with a size / duration smaller than or equal to X. Conversely, STA 1502 may be configured, if the buffered data cannot be transmitted (in its entirety) in a PPDU with a size / duration smaller than or equal to the threshold X, to refrain from transmitting the buffered data during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation).

[0144] In another embodiment, STA 1502 may be configured, if the buffered data can be transmitted (in its entirety) in a PPDU with a size / duration smaller than or equal to the threshold X, to transmit a PPDU with the buffered data to STA 1504 during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation). Conversely, STA 1502 may be configured, if the buffered data cannot be transmitted (in its entirety) in a PPDU with a size / duration smaller than or equal to the threshold X, to fragment the buffered data into fragments that each can be carried in a PPDU with a size / duration smaller than or equal to the threshold X and to transmit one or more of the fragments in respective one or more PPDUs with a size / duration smaller than or equal to the threshold X. This is illustrated in example 1600 of FIG. 16, in which the size / duration of the buffered data for STA 1504 is larger than the threshold X and in which STA 1502 fragments the buffered data and transmits at least a fragment of the buffered data, during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation), in a PPDU 1602 with a size / duration smaller than or equal to X.

[0145] In another embodiment (not shown in FIGs. 15-16), frame 1506 may further indicate one or more additional conditions that limit the amount of traffic that can be transmitted by STA 1502 to STA 1504 during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation). For example, in an embodiment, frame 1506 may further comprise a field indicating a total number of PPDUs that STA 1502 is allowed to transmit to STA 1504 during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation), a field indicating a totalDocket No.: 24-3035PCT number of PPDU fragments that STA 1502 is allowed to transmit to STA 1504 during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation), and / or a field indicating an amount of traffic that STA 1502 is allowed to transmit to STA 1504 during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation). STA 1502 may apply the indicated one or more additional conditions, in addition to the condition on maximum PPDU size / duration indicated in frame 1506, to determine whether STA 1502 may transmit a PPDU to STA 1504 during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation). In another embodiment (not shown in FIGs. 15-16), frame 1506 may further indicate, additionally or alternatively, a condition, as described in FIGs. 11 -14 above, relating to traffic type / category that can be transmitted to STA 1504 during the period of unavailability of STA 1504 (or while STA 1504 is in limited / reduced / adaptive availability / operation).

[0146] FIG. 17 illustrates an example 1700 of another procedure according to an embodiment. Example 1700 is provided for the purpose of illustration only and is not limiting of embodiments. As shown in FIG. 17, example 1700 includes a STA 1702 and a STA 1704. STA 1702 may be an AP STA or a non-AP STA. Similarly, STA 1704 may be an AP STA or a non-AP STA. In an embodiment, STA 1702 may be an AP STA, and STA 1704 may be a non-AP STA. STA 1704 may be associated with STA 1702. In another embodiment, STA 1702 may be a non-AP STA, and STA 1704 may be an AP STA. STA 1702 may be associated with STA 1704.

[0147] As shown in FIG. 17, example 1700 may begin with STA 1704 transmitting a frame 1706 to STA 1702. In embodiments, frame 1706 may comprise an IGF, an ICR, a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame, for example. In an embodiment, frame 1706 comprises an ICR transmitted by STA 1704 in response to an ICF frame from STA 1702. In an embodiment, the ICR transmitted by STA 1704 comprises a multi-STA BlockAck frame, and the ICF transmitted by STA 1702 comprises a BSRP Trigger frame. In an embodiment, STA 1702 transmits the ICF to initiate frame exchanges (that are neither group addressed Data nor group address Management frames) with STA 1704 when STA 1704 operates in a mode in which STA 1704 may inform another STA of its limited / reduced / adaptive availability / operation (e.g., Dynamic Unavailability Operation (DUO) mode, Periodic Unavailability Operation (PUO) mode, or Limited Operation Mode (LOM)). LOM may also be referred to as Adaptive Operation Mode (AOM). In LOM / AOM, a STA may reduce / adapt (or may request from an associated AP to reduce / adapt) parameters / conditions used for communication (transmission / reception) with the STA. In another embodiment, where STA 1704 is a TXOP holder, frame 1706 comprises a BSRP Trigger frame.

[0148] In an embodiment, frame 1706 may indicate a period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1704. The period of unavailability (or limited / reduced / adaptive availability / operation) may be periodic or aperiodic. The period of unavailability (or limited / reduced / adaptiveDocket No.: 24-3035PCT availability / operation) may be due to an IDC event within STA 1704. STA 1704 may be unavailable for communication with other WLAN devices, including STA 1702, during at least a portion of the period of unavailability (or limited / reduced / adaptive availability / operation) to avoid the occurrence of an IDC interference event due to the IDC event. As described above, the duration of the IDC event may be shorter than the period of unavailability indicated in frame 1706. For example, the IDC event may end before the end of the period of unavailability indicated in frame 1706. In an embodiment, frame 1706 indicates an unavailability target start time and an unavailability duration.

[0149] In an embodiment, frame 1706 further indicates a condition for transmission of a PPDU to STA 1704 during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation). In other words, frame 1706 indicates that, notwithstanding the indicated period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1704, a PPDU may be transmitted to STA 1704, during the period of unavailability (or while STA 1704 is in limited / reduced / adaptive availability / operation), provided that the PPDU satisfies the condition indicated in frame 1706.

[0150] In an embodiment, as illustrated in FIG. 17, the condition comprises the PPDU comprising a frame of a first frame type (allowed frame type). In an embodiment, frame 1706 may include a field indicating the first frame type. In an embodiment, the first frame type may comprise an ICF, an ICR, an RTS frame, a CTS frame, a multi-user (MU)-RTS frame, a buffer status report poll (BSRP) trigger frame, a BAR frame, a BA frame, a BSR frame, a control frame, or an action frame, for example. In an embodiment, the frame of the first frame type may be a frame that indicates that STA 1702 has buffered traffic for STA 1704. In an embodiment, the frame of the first frame type may comprise a traffic indication information (e.g., traffic indication map (TIM) element) that indicates that STA 1702 has buffered traffic for STA 1704. In another embodiment, the frame of the first frame type may further indicate a traffic type (e.g., TID, TID bitmap) or an AC of the buffered traffic.

[0151] In an embodiment, based on receiving frame 1706, STA 1702 may be configured to refrain from transmitting to STA 1704, during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation), any PPDU that does not satisfy the condition indicated in frame 1706. Specifically, in example 1700, STA 1702 may be configured to refrain from transmitting to STA 1704, during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation), any PPDU that does not include (or that does not include only) a frame of the first frame type. In an embodiment, STA 1702 may be configured to apply this behavior as long as STA 1702 has not received from STA 1704 a frame indicating the availability of STA 1704.

[0152] Returning to FIG. 17, in an example, after transmitting frame 1706, STA 1704 may exchange one or more frames (not shown in FIG. 17) with STA 1702. For example, STA 1704 may communicate with STA 1702 to transmit and / or receive data to / from STA 1702.Docket No.: 24-3035PCT

[0153] Subsequently, the period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1704 begins. In example 1700, after the period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1704 begins, data for STA 1704 arrives at STA 1702. In an embodiment, STA 1702 may buffer the data for transmission to STA 1704. STA 1702 may then transmit to STA 1704, during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation), a PPDU 1708 comprising a frame of the first frame type. In example 1700, the frame of the first frame type indicates that STA 1702 has buffered traffic for STA 1704. In an example, the frame of the first frame type may further indicate the traffic type (e.g. TID) or the AC of the buffered traffic. In an embodiment, as illustrated in FIG. 17, STA 1702 transmits PPDU 1708 comprising the frame of the first frame type indicating that STA 1702 has buffered traffic for STA 1704 regardless of the traffic type (e.g., TID) or the AC of the buffered traffic. In another embodiment (not shown in FIG. 17), STA 1702 may only transmit PPDU 1708 comprising the frame of the first frame type indicating that STA 1702 has buffered traffic for STA 1704 when the buffered traffic corresponds to a particular traffic type / access category (e.g., LL traffic). In an embodiment, STA 1704 may indicate the particular traffic type / access category to STA 1702.

[0154] In an embodiment, STA 1704 may be configured to transmit a frame in response to PPDU 1708. In an embodiment, as illustrated in FIG. 17, STA 1704 may be configured to transmit a frame 1710 to STA 1702 in response to PPDU 1708, after an end of the IDC event at STA 1704 during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation). Frame 1710 indicates that STA 1704 is available for communication with STA 1702. After receiving frame 1710 from STA 1704, STA 1702 may transmit to STA 1704 a PPDU 1712 comprising a data frame comprising the buffered traffic. STA 1702 may transmit a frame 1714 in response to the data frame comprising the buffered traffic. Frame 1714 may comprise an Ack or a BA frame.

[0155] In another embodiment, as shown in example 1800 of FIG. 18, STA 1704 may be configured to transmit a frame 1802 to STA 1702 in response to PPDU 1708, before an end of the IDC event at STA 1704 during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation). Frame 1802 may be an immediate response frame, such as an Ack frame. Based on receiving frame 1802, STA 1702 may determine that STA 1704 is not yet available for communication with STA 1702. Subsequently, when the IDC event ends at STA 1704, STA 1704 may transmit to STA 1702 frame 1710, discussed above, indicating that STA 1704 is available for communication with STA 1702. STA 1702 may then transmit to STA 1704 PPDU 1712 comprising the data frame comprising the buffered traffic.

[0156] In a further embodiment, as shown in example 1900 of FIG. 19, STA 1704 may optionally transmit to STA 1702 frame 1802, discussed above, in response to PPDU 1708, before an end of the IDC event at STA 1704 during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation). Subsequently, when the IDC event ends at STA 1704, STA 1704 may transmit to STA 1702 frame 1710, discussed above, indicating that STA 1704 is available for communication with STA 1702.Docket No.: 24-3035PCTIn response to frame 1710, STA 1702 may transmit to STA 1704 a frame 1902. Frame 1902 may be an immediate response frame, such as an Ack frame. STA 1702 may then transmit to STA 1704 PPDU 1712 comprising the data frame comprising the buffered traffic.

[0157] In a further embodiment, as shown in example 2000 of FIG. 20, STA 1702 may optionally transmit PPDU 1708, discussed above, indicating that STA 1702 has buffered traffic for STA 1704, and STA 1704 may optionally transmit to STA 1702 frame 1802, discussed above, in response to PPDU 1708, before an end of the IDC event at STA 1704 during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation). Subsequently, when the IDC event ends at STA 1704, STA 1704 may transmit to STA 1702 a frame 2002, indicating that STA 1704 is available for communication with STA 1702 during an availability period. In an implementation, frame 2002 may indicate a duration of the availability period. In an implementation, the availability period may begin after frame 2002. On receiving frame 2002, STA 1702 may determine that STA 1704 is available for communication. In an embodiment, after receiving frame 2002, STA 1702 may transmit to STA 1704 a frame 2004. Frame 2004 may be an immediate response frame, such as an Ack frame. Subsequently, STA 1702 may transmit to STA 1704 a PPDU 2006 comprising a data frame comprising the buffered traffic for STA 1704. As STA 1702 is available during the availability period, STA 1702 may not apply any condition to the transmission of PPDU 2006. STA 1702 may transmit to STA 1704 a frame 2008 in response to the data frame comprising the buffered traffic. Frame 2008 may comprise an Ack or a BA frame. After an end of the availability period (which may be due to a second IDC event), STA 1702 may return to applying any condition(s) indicated in frame 1706 and / or any configured behavior for the transmission of a PPDU to STA 1704 during the remainder of the period of unavailability (or limited / reduced / adaptive availability / operation) of STA 1704

[0158] As would be understood by a person of skill in the art based on the teachings herein, embodiments as described above in FIGs. 17-20 may readily be combined with embodiments described above in FIGs. 11- 14 and / or in FIGs. 15-16. For example, in an embodiment, STA 1702 may transmit to STA 1704, during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation), PPDUs that satisfy a condition, as described in FIGs. 11 -14 above, relating to traffic type / category that can be transmitted to STA 1704 during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation) and / or that satisfy a condition, as described in FIGs. 15-16, relating to a maximum PPDU size / duration that can be transmitted to STA 1704 during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation). In addition, when the buffered traffic does not satisfy the traffic type / category condition and / or the maximum PPDU size / duration, STA 1702 may be configured to implement one of the embodiments described in FIGs. 17-20 to inform STA 1704 of the buffered traffic, which may not be transmitted during the period of unavailability of STA 1704 (or while STA 1704 is in limited / reduced / adaptive availability / operation) according to the condition(s) indicated in frame 1706. An example of such an embodiment is illustrated in FIG. 21Docket No.: 24-3035PCT

[0159] FIG. 21 illustrates an example 2100 of another procedure according to an embodiment. Example 2100 is provided for the purpose of illustration only and is not limiting of embodiments. As shown in FIG. 21 , example 2100 includes a STA 2102 and a STA 2104. STA 2102 may be an AP STA or a non-AP STA. Similarly, STA 2104 may be an AP STA or a non-AP STA. In an embodiment, STA 2102 may be an AP STA, and STA 2104 may be a non-AP STA. STA 2104 may associated with STA 2102. In another embodiment, STA 2102 may be a non-AP STA, and STA 2104 may be an AP STA. STA 2102 may associated with STA 2104.

[0160] As shown in FIG. 21 , example 2100 may begin with STA 2104 transmitting a frame 2106 to STA 2102. In embodiments, frame 2106 may comprise an IGF, an ICR, a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame, for example. In an embodiment, frame 2106 comprises an ICR transmitted by STA 2104 in response to an ICF frame from STA 2102. In an embodiment, the ICR transmitted by STA 2104 comprises a multi-STA BlockAck frame, and the ICF transmitted by STA 2102 comprises a BSRP Trigger frame. In an embodiment, STA 2102 transmits the ICF to initiate frame exchanges (that are neither group addressed Data nor group address Management frames) with STA 2104 when STA 2104 operates in a mode in which STA 2104 may inform another STA of its limited / reduced / adaptive availability / operation (e.g., Dynamic Unavailability Operation (DUO) mode, Periodic Unavailability Operation (PUO) mode, or Limited Operation Mode (LOM)). LOM may also be referred to as Adaptive Operation Mode (AOM). In LOM / AOM, a STA may reduce / adapt (or may request from an associated AP to reduce / adapt) parameters / conditions used for communication (transmission / reception) with the STA. In another embodiment, where STA 2104 is a TXOP holder, frame 2106 comprises a BSRP Trigger frame.

[0161] In an embodiment, frame 2106 may indicate a period of unavailability (or limited / reduced / adaptive availability / operation) of STA 2104. The period of unavailability (or limited / reduced / adaptive availability / operation) may be periodic or aperiodic. The period of unavailability (or limited / reduced / adaptive availability / operation) may be due to an IDC event within STA 2104. STA 2104 may be unavailable for communication with other WLAN devices, including STA 2102, during at least a portion of the period of unavailability (or limited / reduced / adaptive availability / operation) to avoid the occurrence of an IDC interference event due to the IDC event. As described above, the duration of the IDC event may be shorter than the period of unavailability indicated in frame 2106. For example, the IDC event may end before the end of the period of unavailability (or limited / reduced / adaptive availability / operation) indicated in frame 2106 In an embodiment, frame 2106 indicates an unavailability target start time and an unavailability duration for the period of unavailability (or limited / reduced / adaptive availability / operation).

[0162] In an embodiment, frame 2106 further indicates a condition for transmission of a PPDU to STA 2104 during the period of unavailability of STA 2104 (or while STA 2104 is in limited / reduced / adaptive availability / operation). In other words, frame 2106 indicates that, notwithstanding the indicated period ofDocket No.: 24-3035PCT unavailability (or limited / reduced / adaptive availability / operation) of STA 2104, a PPDU may be transmitted to STA 2104, during the period of unavailability of STA 2104 (or while STA 2104 is in limited / reduced / adaptive availability / operation), provided that the PPDU satisfies the condition indicated in frame 2106.

[0163] In an embodiment, as illustrated in FIG. 21 , the condition comprises the PPDU having a size / duration smaller than or equal to a threshold (or a maximum PPDU size / duration) (e.g., X). In an embodiment, frame 2106 may include a field indicating the threshold (or the maximum PPDU size / duration).

[0164] In an embodiment, based on receiving frame 2106, STA 2102 may be configured to refrain from transmitting to STA 2104, during the period of unavailability of STA 2104 (or while STA 2104 is in limited / reduced / adaptive availability / operation), any PPDU that does not satisfy the condition indicated in frame 2106. Specifically, in example 2100, STA 2102 may be configured to refrain from transmitting to STA 2104, during the period of unavailability of STA 2104 (or while STA 2104 is in limited / reduced / adaptive availability / operation), any PPDU that is larger than the threshold (or maximum PPDU size / duration) X indicated in frame 2106. In an embodiment, STA 2102 may be configured to apply this behavior as long as STA 2102 has not received from STA 2104 a frame indicating the availability of STA 2104.

[0165] In an embodiment, frame 2106 may further indicate a first frame type (allowed frame type) that can be transmitted to STA 2104, during the period of unavailability of STA 2104 (or while STA 2104 is in limited / reduced / adaptive availability / operation), when the buffered traffic for STA 2104 cannot be transmitted in a PPDU with a size / duration smaller than or equal to the threshold (or maximum PPDU size / duration). Such an embodiment may be used when fragmentation of the buffered traffic is not available. In an embodiment, frame 2106 may include a field indicating the first frame type. In an embodiment, the first frame type may comprise an ICF, an ICR, an RTS frame, a CTS frame, an MU-RTS frame, a BSRP trigger frame, a BAR frame, a BA frame, a BSR frame, a control frame, or an action frame, for example. In an embodiment, the frame of the first frame type may be a frame that indicates that STA 2102 has buffered traffic for STA 2104. In an embodiment, the frame of the first frame type may comprise a traffic indication information (e.g., TIM element) that indicates that STA 2102 has buffered traffic for STA 2104. In another embodiment, the frame of the first frame type may further indicate a traffic type (e.g., TID or TID bitmap) or an AC of the buffered traffic.

[0166] In an embodiment, based on receiving frame 2106, STA 2102 may be configured to refrain from transmitting to STA 2104, during the period of unavailability of STA 2104 (or while STA 2104 is in limited / reduced / adaptive availability / operation), any PPDU that does not satisfy the condition indicated in frame 2106. Specifically, in example 2100, STA 2102 may be configured to refrain from transmitting to STA 2104, during the period of unavailability of STA 2104 (or while STA 2104 is in limited / reduced / adaptive availability / operation), any PPDU that is larger than the threshold (or maximum PPDU size / duration) X indicated in frame 2106.Docket No.: 24-3035PCT

[0167] Returning to FIG. 21 , in an example, after transmitting frame 2106, STA 2104 may exchange one or more frames (not shown in FIG. 21 ) with STA 2102. For example, STA 2104 may communicate with STA 2102 to transmit and / or receive data to / from STA 2102.

[0168] Subsequently, the period of unavailability (or limited / reduced / adaptive availability / operation) of STA 2104 begins. In example 2100, after the period of unavailability (or limited / reduced / adaptive availability / operation) of STA 2104 begins, data for STA 2104 arrives at STA 2102. In an embodiment, STA 2102 may buffer the data for transmission to STA 2104. In an embodiment, STA 2102 may determine whether the buffered data can be transmitted in a PPDU with a size / duration smaller than or equal to the threshold X indicated in frame 2106. In an embodiment, STA 2102 may be configured, if the buffered data can be transmitted (in its entirety) in a PPDU with a size / duration smaller than or equal to the threshold X, to transmit a PPDU with the buffered data to STA 2104 during the period of unavailability of STA 2104 (or while STA 2104 is in limited / reduced / adaptive availability / operation). Conversely, STA 2102 may be configured, if the buffered data cannot be transmitted (in its entirety) in a PPDU with a size / duration smaller than or equal to the threshold X, to transmit to STA 2104, during the period of unavailability of STA 2104 (or while STA 2104 is in limited / reduced / adaptive availability / operation), a PPDU comprising a frame of the first frame type indicated in frame 2106. The frame of the first frame type indicates that STA 2102 has buffered traffic for STA 2104. In an example, the frame of the first frame type may further indicate the traffic type (e.g. TID) or the AC of the buffered traffic.

[0169] In example 2100, the buffered data is larger than the threshold X and thus may not be transmitted (in its entirety) in a PPDU with a size / duration smaller than or equal to the threshold X. As such, as illustrated in FIG. 21 , STA 2102 transmits to STA 2104 a PPDU 2108, during the period of unavailability of STA 2104 (or while STA 2104 is in limited / reduced / adaptive availability / operation), comprising a frame of the first frame type indicating that STA 2102 has buffered traffic for STA 2104. Optionally, STA 2104 may transmit a frame 21 10 to STA 2102 in response to PPDU 2108, before an end of the IDC event at STA 2104 during the period of unavailability of STA 2104 (or while STA 2104 is in limited / reduced / adaptive availability / operation). Frame 21 10 may be an immediate response frame, such as an Ack frame. Based on receiving frame 2110, STA 2102 may determine that STA 2104 is not yet available for communication with STA 2102. Subsequently, when the IDC event ends at STA 2104, STA 2104 may transmit to STA 2102 a frame 21 12. Frame 2112 indicates that STA 2104 is available for communication with STA 2102. In response to frame 2112, STA 2102 may transmit to STA 2104 a frame 2114. Frame 21 14 may be an immediate response frame, such as an Ack frame. STA 2102 may then transmit to STA 2104 a PPDU 2116 comprising the data frame comprising the buffered traffic. STA 2102 may transmit a frame 2118 in response to the data frame comprising the buffered traffic. Frame 2118 may comprise an Ack or a BA frame.

[0170] FIG. 22 illustrates an example process 2200 according to an embodiment. Example process 2200 is provided for the purpose of illustration only and is not limiting. Example process 2200 may be performed byDocket No.: 24-3035PCT a first STA, such as STA 1102, STA 1502, STA 1702, or STA 2102, for example. In an embodiment, the first STA may be an AP STA or a non-AP STA.

[0171] As shown in FIG 22, process 2200 may include a step 2202, which includes receiving, by the first STA from a second STA, a first frame. The second STA may be similar to STA 1 104, STA 1504, STA 1704, or STA 2104, for example. In an embodiment, the second STA may be an AP STA or a non-AP STA. In an embodiment, the first STA may be an AP STA, and the second STA may be a non-AP STA. The second STA may be associated with the first STA.

[0172] The first frame may comprise an ICF, an ICR, a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame, for example. In an embodiment, the first frame comprises an ICR transmitted by the second STA in response to an ICF frame from the first STA. In an embodiment, the ICR transmitted by the second STA comprises a multi-STA BlockAck frame, and the ICF transmitted by the first STA comprises a BSRP Trigger frame. In an embodiment, the first STA transmits the ICF to initiate frame exchanges (that are neither group addressed Data nor group address Management frames) with the second STA when the second STA operates in a mode in which the second STA may inform another STA of its limited / reduced / adaptive availability / operation (e.g., Dynamic Unavailability Operation (DUO) mode, Periodic Unavailability Operation (PUO) mode, or Limited Operation Mode (LOM)). LOM may also be referred to as Adaptive Operation Mode (AOM). In LOM / AOM, a STA may reduce / adapt (or may request from an associated AP to reduce / adapt) parameters used for communication (transmission / reception) with the STA. In another embodiment, where the second STA is a TXOP holder, the first frame comprises a BSRP Trigger frame.

[0173] In an embodiment, the first frame may indicate a period of unavailability (or limited / reduced / adaptive availability / operation) of the second STA. The period of unavailability (or limited / reduced / adaptive availability / operation) may be periodic or aperiodic. In an embodiment, the period of unavailability (or limited / reduced / adaptive availability / operation) may be due to an IDC event at the second STA. In an embodiment, the first frame indicates a start time and duration for the period of unavailability (or limited / reduced / adaptive availability / operation). Alternatively, or additionally, the first frame may indicate a condition for transmission (e.g., by the first STA) of a PPDU to the second STA during the period of unavailability of the second STA (or while the second STA is in limited / reduced / adaptive availability / operation).

[0174] In an embodiment, the condition may comprise the PPDU comprising a data frame with a TID equal to a first TID or with an AC equal to a first AC. In an embodiment, the first TID or the first AC may correspond to low-latency traffic or to urgent traffic, for example. In an embodiment, the first TID or the first AC may correspond to traffic that the second STA wants to receive during the period of unavailability (or while the second STA is in limited / reduced / adaptive availability / operation).Docket No.: 24-3035PCT

[0175] In an embodiment, the first frame comprises a first field indicating the first TID or the first AC. In an embodiment, the first field indicates the first TID. As such, the first field may comprise a TID bitmap comprising a first bit corresponding to the first TID In another embodiment, the first field indicates the first AC. As such, the first field may comprise an AC bitmap comprising a first bit corresponding to the first AC. In an embodiment, the first AC comprises AC_VO, AC_VI, AC_BE, or AC_BK.

[0176] In another embodiment, the condition may, additionally or alternatively, comprise the PPDU having a size / duration smaller than or equal to a threshold. In an embodiment, the first frame comprises a second field indicating the threshold or a maximum size / duration of the PPDU.

[0177] In a further embodiment, the condition may, additionally or alternatively, comprise the first STA not exceeding a total number of PPDUs that the first STA is allowed to transmit to the second STA during the period of unavailability of the second STA (or while the second STA is in limited / reduced / adaptive availability / operation). In an embodiment, the first frame comprises a third field indicating a total number of PPDUs that the first STA is allowed to transmit to the second STA during the period of unavailability of the second STA (or while the second STA is in limited / reduced / adaptive availability / operation).

[0178] In a further embodiment, the condition may, additionally or alternatively, comprise the first STA not exceeding a total number of PPDUs that the first STA is allowed to transmit to the second STA during the period of unavailability of the second STA (or while the second STA is in limited / reduced / adaptive availability / operation). In an embodiment, the first frame comprises a fourth field indicating a total number of PPDU fragments that the first STA is allowed to transmit to the second STA during the period of unavailability of the second STA (or while the second STA is in limited / reduced / adaptive availability / operation).

[0179] In a further embodiment, the condition may, additionally or alternatively, comprise the first STA not exceeding a total amount of traffic that the first STA is allowed to transmit to the second STA during the period of unavailability of the second STA (or while the second STA is in limited / reduced / adaptive availability / operation). In an embodiment, the first frame comprises a fifth field indicating an amount of traffic that the first STA is allowed to transmit to the second STA during the period of unavailability of the second STA (or while the second STA is in limited / reduced / adaptive availability / operation).

[0180] In a further embodiment, the condition may, additionally or alternatively, comprise the PPDU comprising a frame of a first frame type. In an embodiment, the first frame comprises a first field indicating the first frame type. In an embodiment, the first frame type may comprise an ICF, an ICR, an RTS frame, a CTS frame, an MU-RTS frame, a BSRP trigger frame, a BAR frame, a BA frame, a BSR frame, a control frame, or an action frame, for example. In an embodiment, the frame of the first frame type indicates that the first STA has buffered traffic for the second STA. In an embodiment, the frame of the first frame type further indicates a traffic type or an AC of the buffered traffic.

[0181] In an embodiment, process 2200 may further comprise, after receiving the first frame, transmitting, by the first STA to the second STA and during the period of unavailability of the second STA (or while theDocket No.: 24-3035PCT second STA is in limited / reduced / adaptive availability / operation), a first PPDU based on the condition. In an embodiment, the first PPDU comprises a data frame. The data frame may comprise the buffered frame. In another embodiment, the first PPDU indicates that the first STA has buffered traffic for the second STA In an embodiment, the first PPDU further may further indicates a type or an AC of the buffered traffic. The first PPDU may comprise a frame of the first frame type. As such, the first PPDU may comprise an ICF, an ICR, an RTS frame, a CTS frame, an MU-RTS frame, a BSRP trigger frame, a BAR frame, a BA frame, a BSR frame, a control frame, or an action frame.

[0182] In an embodiment, process 2200 may further comprise receiving, by the first STA from the second STA, a second frame in response to the first PPDU. In an embodiment, the second frame indicates that the second STA is available to communicate with the first STA. In an embodiment, the first STA receives the second frame from the second STA after an IDC event at the second STA ends during the period of unavailability of the second STA (or while the second STA is in limited / reduced / adaptive availability / operation). In another embodiment, the first STA receives the second frame from the second STA before an IDC at the second STA ends. The second frame may comprise a PS-Poll frame, an ICF, an ICR, a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame.

[0183] In an embodiment, process 2200 may further comprise receiving, from the second STA, an immediate response frame a SIFS after transmitting the first PPDU. The immediate response frame may comprise an Ack frame or a BA frame.

[0184] In an embodiment, process 2200 may further comprise, after receiving the second frame, transmitting, by the first STA to the second STA, the buffered traffic In an embodiment, process 2200 may further comprise receiving, by the first STA from the second STA, an immediate response frame in response to the buffered traffic.

[0185] In another embodiment, process 2200 may further comprise transmitting, by the first STA to the second STA, an immediate response frame in response to the second frame; transmitting, by the first STA to the second STA, the buffered traffic; and receiving, by the first STA from the second STA, an immediate response frame in response to the buffered traffic.

[0186] In an embodiment, process 2200 may further comprise, where a size / duration of the buffered traffic is larger than a maximum PPDU size / duration indicated by the second STA, fragmenting, by the first STA, the buffered traffic based on the maximum PPDU size / duration. In an embodiment, process 2200 may further comprise transmitting fragments of the buffered traffic during the period of unavailability of the second STA (or while the second STA is in limited / reduced / adaptive availability / operation). In an embodiment, process 2200 may further comprise, where a size / duration of the buffered traffic is smaller than a maximum PPDU size / duration indicated by the second STA, transmitting the buffered traffic to the second STA, withoutDocket No.: 24-3035PCT fragmentation, during the period of unavailability of the second STA (or while the second STA is in limited / reduced / adaptive availability / operation).

[0187] FIG. 23 illustrates another example process according to an embodiment. Example process 2300 is provided for the purpose of illustration only and is not limiting. Example process 2300 may be performed by a first STA, such as STA 1104, STA 1504, STA 1704, or STA 2104, for example. In an embodiment, the first STA may be an AP STA or a non-AP STA.

[0188] As shown in FIG. 23, process 2300 may include a step 2302, which includes transmitting, by the first STA to a second STA, a first frame. The second STA may be similar to STA 1102, STA 1502, STA 1702, or STA 2102, for example. In an embodiment, the second STA may be an AP STA or a non-AP STA. In an embodiment, the first STA may be a non-AP STA, and the second STA may be an AP STA. The first STA may be associated with the second STA.

[0189] The first frame may comprise an ICF, an ICR, a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame, for example. In an embodiment, the first frame comprises an ICR transmitted by the first STA in response to an ICF frame from the second STA. In an embodiment, the ICR transmitted by the first STA comprises a multi-STA BlockAck frame, and the ICF transmitted by the second STA comprises a BSRP Trigger frame. In an embodiment, the second STA transmits the ICF to initiate frame exchanges (that are neither group addressed Data nor group address Management frames) with the first STA when the first STA operates in a mode in which the first STA may inform another STA of its limited / reduced / adaptive availability / operation (e.g., Dynamic Unavailability Operation (DUO) mode, Periodic Unavailability Operation (PUO) mode, or Limited Operation Mode (LOM)). LOM may also be referred to as Adaptive Operation Mode (AOM). In LOM / AOM, a STA may reduce / adapt (or may request from an associated AP to reduce / adapt) parameters used for communication (transmission / reception) with the STA. In another embodiment, where the first STA is a TXOP holder, the first frame comprises a BSRP Trigger frame.

[0190] In an embodiment, the first frame may indicate a period of unavailability (or limited / reduced / adaptive availability / operation) of the first STA. The period of unavailability (or limited / reduced / adaptive availability / operation) may be periodic or aperiodic. In an embodiment, the period of unavailability (or limited / reduced / adaptive availability / operation) of the first STA may be due to an IDC event at the first STA. In an embodiment, the first frame indicates a start time and a duration for the period of unavailability (or limited / reduced / adaptive availability / operation) of the first STA. Alternatively, or additionally, the first frame may indicate a condition for transmission (e.g., by the second STA) of a PPDU to the first STA during the period of unavailability of the first STA (or while the first STA is in limited / reduced / adaptive availability / operation).

[0191] In an embodiment, the condition may comprise the PPDU comprising a data frame with a TID equal to a first TID or with an AC equal to a first AC. In an embodiment, the first TID or the first AC may correspondDocket No.: 24-3035PCT to low-latency traffic or to urgent traffic, for example. In an embodiment, the first TID or the first AC may correspond to traffic that the first STA wants to receive during the period of unavailability of the first STA (or while the first STA is in limited / reduced / adaptive availability / operation).

[0192] In an embodiment, the first frame comprises a first field indicating the first TID or the first AC. In an embodiment, the first field indicates the first TID. As such, the first field may comprise a TID bitmap comprising a first bit corresponding to the first TID. In another embodiment, the first field indicates the first AC. As such, the first field may comprise an AC bitmap comprising a first bit corresponding to the first AC. In an embodiment, the first AC comprises AC_VO, AC_VI, AC_BE, or AC_BK.

[0193] In another embodiment, the condition may, additionally or alternatively, comprise the PPDU having a size / duration smaller than or equal to a threshold. In an embodiment, the first frame comprises a second field indicating the threshold or a maximum size / duration of the PPDU.

[0194] In a further embodiment, the condition may, additionally or alternatively, comprise the second STA not exceeding a total number of PPDUs that the second STA is allowed to transmit to the first STA during the period of unavailability of the first STA (or while the first STA is in limited / reduced / adaptive availability / operation). In an embodiment, the first frame comprises a third field indicating a total number of PPDUs that the second STA is allowed to transmit to the first STA during the period of unavailability of the first STA (or while the first STA is in limited / reduced / adaptive availability / operation).

[0195] In a further embodiment, the condition may, additionally or alternatively, comprise the second STA not exceeding a total number of PPDUs that the second STA is allowed to transmit to the first STA during the period of unavailability of the first STA (or while the first STA is in limited / reduced / adaptive availability / operation). In an embodiment, the first frame comprises a fourth field indicating a total number of PPDU fragments that the second STA is allowed to transmit to the first STA during the period of unavailability of the first STA (or while the first STA is in limited / reduced / adaptive availability / operation).

[0196] In a further embodiment, the condition may, additionally or alternatively, comprise the second STA not exceeding a total amount of traffic that the second STA is allowed to transmit to the first STA during the period of unavailability of the first STA (or while the first STA is in limited / reduced / adaptive availability / operation). In an embodiment, the first frame comprises a fifth field indicating an amount of traffic that the second STA is allowed to transmit to the first STA during the period of unavailability of the first STA (or while the first STA is in limited / reduced / adaptive availability / operation).

[0197] In a further embodiment, the condition may, additionally or alternatively, comprise the PPDU comprising a frame of a first frame type. In an embodiment, the first frame comprises a first field indicating the first frame type. In an embodiment, the first frame type may comprise an ICF, an ICR, an RTS frame, a CTS frame, an MU-RTS frame, a BSRP trigger frame, a BAR frame, a BA frame, a BSR frame, a control frame, or an action frame, for example. In an embodiment, the frame of the first frame type indicates that theDocket No.: 24-3035PCT second STA has buffered traffic for the first STA. In an embodiment, the frame of the first frame type further indicates a traffic type or an AC of the buffered traffic.

[0198] In an embodiment, process 2300 may further comprise, after transmitting the first frame, receiving, by the first STA from the second STA and during the period of unavailability of the first STA (or while the first STA is in limited / reduced / adaptive availability / operation), a first PPDU based on the condition. In an embodiment, the first PPDU comprises a data frame. The data frame may comprise the buffered frame. In another embodiment, the first PPDU indicates that the second STA has buffered traffic for the first STA. In an embodiment, the first PPDU further may further indicates a type or an AC of the buffered traffic. The first PPDU may comprise a frame of the first frame type. As such, the first PPDY may comprise an ICF, an ICR, an RTS frame, a CTS frame, an MU-RTS frame, a BSRP trigger frame, a BAR frame, a BA frame, a BSR frame, a control frame, or an action frame.

[0199] In an embodiment, process 2300 may further comprise transmitting, by the first STA to the second STA, a second frame in response to the first PPDU. In an embodiment, the second frame indicates that the first STA is available to communicate with the second STA. In an embodiment, transmitting the second frame comprises transmitting the second frame after an IDC event at the first STA ends during the period of unavailability of the first STA (or while the first STA is in limited / reduced / adaptive availability / operation). In another embodiment, transmitting the second frame comprises transmitting the second frame before an IDC at the first STA ends. The second frame may comprise a PS-Poll frame, an ICF, an ICR, a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame.

[0200] In an embodiment, process 2300 may further comprise transmitting, to the second STA, an immediate response frame a SIFS after receiving the first PPDU. The immediate response frame may comprise an Ack frame or a BA frame.

[0201] In an embodiment, process 2300 may further comprise, after transmitting the second frame, receiving, by the first STA from the second STA, the buffered traffic. In an embodiment, process 2300 may further comprise transmitting, by the first STA to the second STA, an immediate response frame in response to the buffered traffic.

[0202] In another embodiment, process 2300 may further comprise receiving, by the first STA from the second STA, an immediate response frame in response to the second frame; receiving, by the first STA from the second STA, the buffered traffic; and transmitting, by the first STA to the second STA, an immediate response frame in response to the buffered traffic.

Claims

Docket No.: 24-3035PCTCLAIMSWhat is claimed is:

1. A method comprising: receiving, by an access point (AP) from a station (STA), a first frame indicating: adaptive operation of the STA; and a condition for transmission of a physical layer protocol data unit (PPDU) to the STA while the STA is in adaptive operation; transmitting, by the AP to the STA and while the STA is in adaptive operation, a first PPDU based on the condition; and receiving, by the AP from the STA and after an in-device coexistence (IDC) event ends while the STA is in adaptive operation, a second frame in response to the first PPDU.

2. A method comprising: receiving, by a first station (STA) from a second STA, a first frame indicating: adaptive operation of the second STA; and a condition for transmission of a physical layer protocol data unit (PPDU) to the second STA while the second STA is in adaptive operation.

3. The method of claim 2, wherein the condition comprises the PPDU comprising a data frame with a traffic identifier (TID) equal to a first TID or with an access category (AC) equal to a first AC.

4. The method of claim 3, wherein the first TID or the first AC corresponds to low-latency traffic or to urgent traffic.

5. The method of claim 3, wherein the first TID or the first AC corresponds to traffic that the second STA wants to receive while in adaptive operation.

6. The method of any of claims 3-5, wherein the first frame comprises a first field indicating the first TID or the first AC.

7. The method of claim 6, wherein the first field indicates the first TID.

8. The method of claim 7, wherein the first field comprises a TID bitmap comprising a first bit corresponding to the first TID.

9. The method of claim 6, wherein the first field indicates the first AC.

10. The method of claim 9, wherein the first field comprises an AC bitmap comprising a first bit corresponding to the first AC11. The method of any of claims 9-10, wherein the first AC comprises AC_VO, AC_VI, AC_BE, or AC_BK.

12. The method of claim 2, wherein the condition comprises the PPDU having a size or a duration smaller than or equal to a threshold.

13. The method of any of claims 2-12, wherein the first frame comprises a second field indicating a maximum size or duration of the PPDU.Docket No.: 24-3035PCT14. The method of any of claims 2-13, wherein the first frame comprises a third field indicating a total number of PPDUs that the first STA is allowed to transmit to the second STA while the second STA is in adaptive operation.

15. The method of any of claims 2-14, wherein the first frame comprises a fourth field indicating a total number of PPDU fragments that the first STA is allowed to transmit to the second STA while the second STA is in adaptive operation.

16. The method of any of claims 2-15, wherein the first frame comprises a fifth field indicating an amount of traffic that the first STA is allowed to transmit to the second STA while the second STA is in adaptive operation.

17. The method of claim 2, wherein the condition comprises the PPDU comprising a frame of a first frame type.

18. The method of claim 17, wherein the first frame comprises a first field indicating the first frame type.

19. The method of any of claims 17-18, wherein the first frame type comprises an initial control frame (IGF), an initial control response frame (ICR), a request-to-send (RTS) frame, a clear-to-send (CTS) frame, a multi-user (MU)-RTS frame, a buffer status report poll (BSRP) trigger frame, a block ack request (BAR) frame, a block ack (BA) frame, a buffer status report (BSR) frame, a control frame or an action frame.

20. The method of any of claims 17-19, wherein the frame of the first frame type indicates that the first STA has buffered traffic for the second STA.21 . The method of claim 20, wherein the frame of the first frame type further indicates a type or an access category (AC) of the buffered traffic.

22. The method of any of claims 2-21 , wherein the first frame comprises an initial control frame (ICF), an initial control response frame (ICR), a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame.

23. The method of any of claims 2-22, further comprising: after receiving the first frame, transmitting, by the first STA to the second STA and while the second STA is in adaptive operation, a first PPDU based on the condition; and receiving, by the first STA from the second STA, a second frame in response to the first PPDU.

24. The method of claim 23, wherein the first STA receives the second frame from the second STA after an in-device coexistence (IDC) event at the second STA ends while the second STA is in adaptive operation.

25. The method of claim 23, wherein the first STA receives the second frame from the second STA before an in-device coexistence event (IDC) at the second STA ends.

26. The method of any of claims 23-25, wherein the second frame indicates that the second STA is available to communicate with the first STA.Docket No.: 24-3035PCT27. The method of any of claims 22-26, wherein the second frame comprises a power save poll (PS-Poll) frame, an initial control frame (IGF), an initial control response frame (ICR), a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame.

28. The method of any of claims 23-27, further comprising receiving, from the second STA, an immediate response frame a short interframe space (SIPS) after transmitting the first PPDU.

29. The method of claim 28, wherein the immediate response frame comprises an acknowledgment (Ack) frame or a block ack (BA) frame.

30. The method of any of claims 23-29, wherein the first PPDU comprises an initial control frame (ICF), an initial control response frame (ICR), a request-to-send (RTS) frame, a clear-to-send (CTS) frame, a multi-user (MU)-RTS frame, a buffer status report poll (BSRP) trigger frame, a block ack request (BAR) frame, a block ack (BA) frame, a buffer status report (BSR) frame, a control frame or an action frame.31 . The method of any of claims 23-30, wherein the first PPDU indicates that the first STA has buffered traffic for the second STA.

32. The method of claim 31 , wherein the first PPDU further indicates a type or an access category (AC) of the buffered traffic.

33. The method of any of claims 31 -32, further comprising: after receiving the second frame, transmitting, by the first STA to the second STA, the buffered traffic; and receiving, by the first STA from the second STA, an immediate response frame in response to the buffered traffic.

34. The method of any of claims 31 -32, further comprising: transmitting, by the first STA to the second STA, an immediate response frame, in response to the second frame; transmitting, by the first STA to the second STA, the buffered traffic; and receiving, by the first STA from the second STA, an immediate response frame in response to the buffered traffic.

35. The method of any of claims 32-34, wherein a size of the buffered traffic is larger than a maximum PPDU size indicated by the second STA, the method further comprising fragmenting, by the first STA, the buffered traffic based on the maximum PPDU size.

36. The method of any of claims 32-34, wherein a size of the buffered traffic is smaller than a maximum PPDU size indicated by the second STA, the method further comprising transmitting the buffered traffic to the second STA, without fragmentation, while the second STA is in adaptive operation.

37. The method of any of claims 2-36, wherein the first STA comprises an access point (AP) STA.

38. The method of any of claims 2-37, wherein the second STA comprises a non-access point (non-AP) STA.Docket No.: 24-3035PCT39. A method comprising: transmitting, by a station (STA) to an access point (AP), a first frame indicating: adaptive operation of the STA; and a condition for transmission of a physical layer protocol data unit (PPDU) to the STA while the STA is in adaptive operation, wherein the condition indicates a maximum duration of the PPDU; receiving, by the STA from the AP and while in the STA is in adaptive operation, a first PPDU based on the condition, wherein a duration of the first PPDU is shorter than the maximum duration of the PPDU; and transmitting, by the STA to the AP and after an in-device coexistence (IDC) event ends while the STA is in adaptive operation, a second frame in response to the first PPDU.

40. A method comprising: transmitting, by a first station (STA) to a second STA, a first frame indicating: adaptive operation of the first STA; and a condition for transmission of a physical layer protocol data unit (PPDU) to the STA while the first STA is in adaptive operation.

41. The method of claim 40, wherein the condition comprises the PPDU comprising a data frame with a traffic identifier (TID) equal to a first TID or with an access category (AC) equal to a first AC.

42. The method of claim 41 , wherein the first TID or the first AC corresponds to low-latency traffic or to urgent traffic.

43. The method of claim 41 , wherein the first TID or the first AC corresponds to traffic that the first STA wants to receive while in adaptive operation.

44. The method of any of claims 41-43, wherein the first frame comprises a first field indicating the first TID or the first AC.

45. The method of claim 44, wherein the first field indicates the first TID.

46. The method of claim 45, wherein the first field comprises a TID bitmap comprising a first bit corresponding to the first TID.

47. The method of claim 46, wherein the first field indicates the first AC.

48. The method of claim 47, wherein the first field comprises an AC bitmap comprising a first bit corresponding to the first AC.

49. The method of any of claims 47-48, wherein the first AC comprises AC_VO, AC_VI, AC_BE, or AC_BK.

50. The method of claim 40, wherein the condition comprises the PPDU having a size or a duration smaller than or equal to a threshold.

51. The method of any of claims 40-50, wherein the first frame comprises a second field indicating a maximum size or duration of the PPDU.Docket No.: 24-3035PCT52. The method of any of claims 40-51 , wherein the first frame comprises a third field indicating a total number of PPDUs that the second STA is allowed to transmit to the first STA while the first STA is in adaptive operation.

53. The method of any of claims 40-52, wherein the first frame comprises a fourth field indicating a total number of PPDU fragments that the second STA is allowed to transmit to the first STA while the first STA is in adaptive operation.

54. The method of any of claims 40-53, wherein the first frame comprises a fifth field indicating an amount of traffic that the second STA is allowed to transmit to the first STA while the first STA is in adaptive operation.

55. The method of claim 40, wherein the condition comprises the PPDU comprising a frame of a first frame type.

56. The method of claim 55, wherein the first frame comprises a first field indicating the first frame type.

57. The method of any of claims 55-56, wherein the first frame type comprises an initial control frame (IGF), an initial control response frame (ICR), a request-to-send (RTS) frame, a clear-to-send (CTS) frame, a multi-user (MU)-RTS frame, a buffer status report poll (BSRP) trigger frame, a block ack request (BAR) frame, a block ack (BA) frame, a buffer status report (BSR) frame, a control frame or an action frame.

58. The method of any of claims 55-57, wherein the frame of the first frame type indicates that the second STA has buffered traffic for the first STA.

59. The method of claim 58, wherein the frame of the first frame type further indicates a type or an access category (AC) of the buffered traffic.

60. The method of any of claims 40-59, wherein the first frame comprises an initial control frame (ICF), an initial control response frame (ICR), a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame.61 . The method of any of claims 40-60, further comprising: after transmitting the first frame, receiving, by the first STA from the second STA and while the first STA is in adaptive operation, a first PPDU based on the condition; and transmitting, by the first STA to the second STA, a second frame in response to the first PPDU.

62. The method of claim 61 , wherein transmitting the second frame comprises transmitting the second frame after an in-device coexistence (IDC) event at the first STA ends while the first STA is in adaptive operation.

63. The method of claim 61 , wherein transmitting the second frame comprises transmitting the second before an in-device coexistence event (IDC) at the first STA ends.

64. The method of claims 61-63, wherein the second frame indicates that the first STA is available to communicate with the second STA.Docket No.: 24-3035PCT65. The method of any of claims 60-64, wherein the second frame comprises a power save poll (PS-Poll) frame, an initial control frame (IGF), an initial control response frame (ICR), a request frame, a response frame, a control frame, a management frame, an action frame, a QoS null frame, or a QoS data frame.

66. The method of any of claims 61 -65, further comprising transmitting to the second STA an immediate response frame a short interframe space (SIPS) after receiving the first PPDU.

67. The method of claim 66, wherein the immediate response comprises an acknowledgment (Ack) frame or a block ack (BA) frame.

68. The method of any of claims 61 -67, wherein the first PPDU comprises an initial control frame (ICF), an initial control response frame (ICR), a request-to-send (RTS) frame, a clear-to-send (CTS) frame, a multi-user (MU)-RTS frame, a buffer status report poll (BSRP) trigger frame, a block ack request (BAR) frame, a block ack (BA) frame, a buffer status report (BSR) frame, a control frame or an action frame.

69. The method of any of claims 62-68, wherein the first PPDU indicates that the second STA has buffered traffic for the first STA.

70. The method of claim 69, wherein the first PPDU further indicates a type or an access category (AC) of the buffered traffic.71 . The method of any of claims 69-70, further comprising: after transmitting the second frame, receiving, by the first STA from the second STA, the buffered traffic; and transmitting, by the first STA to the second STA, an immediate response frame in response to the buffered traffic.

72. The method of any of claims 69-70, further comprising: receiving, by the first STA from the second STA, an immediate response frame, in response to the second frame; receiving, by the first STA from the second STA, the buffered traffic; and transmitting, by the first STA to the second STA, an immediate response frame in response to the buffered traffic.

73. The method of any of claims 40-72, wherein the first STA comprises a non-access point (non-AP) STA.

74. The method of any of claims 40-73, wherein the second STA comprises an access point (AP) STA.

75. A device comprising: 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 1-74.

76. 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 1-74.

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