Power saving operations during a triggered transmission opportunity sharing procedure

Abstract

A station (STA) receives, from an access point (AP), a first frame indicating: a first time period, of a transmit opportunity (TXOP), allocated to the STA, and a sharing mode of the first time period. The STA transmits, to the AP and during the first time period, a second frame indicating a return by the STA of the first time period to the AP. After transmitting the second frame, the STA transition from a first power state to a second power state based on the sharing mode.

Description

POWER SAVING OPERATIONS DURING A TRIGGERED TRANSMISSION OPPORTUNITY SHARING PROCEDURECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Nos. 63 / 620,513, filed January 12, 2024, and 63 / 563,665, filed March 11 , 2024, all of which are hereby incorporated by reference in their entireties.BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0005] FIG. 3 illustrates an example multi-user request to send (MU-RTS) transmission opportunity sharing (TXS) trigger (MRTT) frame which may be used in a TXS procedure.

[0006] FIG. 4 illustrates an example of a TXS procedure (Mode =1).

[0007] FIG. 5 illustrates an example of a TXS procedure (Mode =2).

[0008] FIG. 6 is an example that illustrates an example TXS procedure between multi-link devices (MLDs).

[0009] FIG. 7 is an example that illustrates an inefficient STA operation that may occur during a TXS procedure.

[0010] FIG. 8 is an example that illustrates a TXS Power Save (PS) mode.

[0011] FIG. 9 is an example that illustrates a STA enabling or disabling the TXS PS mode in an example implementation.

[0012] FIG. 10 is an example that illustrates a STA enabling or disabling the TXS PS mode according to another example implementation.

[0013] FIG. 11 is an example that illustrates a STA enabling or disabling the TXS PS mode according to a further example implementation.

[0014] FIG. 12 illustrates an example of existing operation whereby a STA may enter a doze state during a target wake time (TWT) service period (SP).

[0015] FIG. 13 illustrates an example that illustrates an example TXS procedure.

[0016] FIG. 14 illustrates an example of one or more embodiments that may utilize a power saving operation during aTXS procedure.

[0017] FIG. 15 illustrates an example of one or more embodiments that may utilize a power saving operation during aTXS procedure.

[0018] FIG. 16 illustrates an example of one or more embodiments that may utilize a power saving operation during aTXS procedure.

[0019] FIG. 17 illustrates an example of one or more embodiments that may utilize a power saving operation during a TXS procedure.

[0020] FIG. 18 illustrates an example of one or more embodiments that may utilize a power saving operation during a TXS procedure.

[0021] FIG. 19 illustrates an example of one or more embodiments that may utilize a power saving operation during a TXS procedure

[0022] FIG. 20 illustrates an example of one or more embodiments that may utilize a power saving operation during a TXS procedure.

[0023] FIG. 21 describes different signaling capabilities for one or more embodiments.

[0024] FIG. 22 illustrates an example process according to an embodiment.

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

[0026] FIG. 24 illustrates an example of one or more embodiments that may utilize a power saving operation during a TXS procedure.DETAILED DESCRIPTION

[0027] 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 that shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments.

[0028] 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.

[0029] 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 ormore 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.

[0030] If A and B are sets and every element of A is an element of B, A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B = {STA1, STA2) are: {STA1 }, {STA2}, and {STA1 , STA2}. The phrase “based on” (or equally “based at least on”) is indicative that the phrase following the term “based on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “in response to” (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “depending on” (or equally “depending at least to”) is indicative that the phrase following the phrase “depending on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “employi ng / 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.

[0031] 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.

[0032] 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.

[0033] 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 explicitlydisclosing 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.

[0034] Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g. hardware with a biological element) or a combination thereof, which may be behavioral ly 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.

[0035] FIG. 1 illustrates example 100 wireless communication networks in which embodiments of the present disclosure may be implemented. 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 (BBSs) 110 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 110-2 includes an AP 104-2 and STAs 106-2 and 106-3. The AP and the at least one STA in a BSS perform an association procedure to communicate with each other.

[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 130 and 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 thatare 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).

[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” maybe used to denote a STA participating in uplink Multi-user Multiple Input, Multiple Output (MU MIMO) and / or uplink Orthogonal Frequency Division Multiple Access (OFDMA) transmission.

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

[0043] A frequency band may include one or more sub-bands or frequency channels. For example, PPDUs conforming to the IEEE 802.11n, 802.11ac, 802.11 ax and / or 802.11 be standard amendments may be transmitted over the 2.4 GHz, 5 GHz, and / or 6 GHz bands, each of which may be divided into multiple 20 MHz channels. The PPDUs may be transmitted over a physical channel having a minimum bandwidth of 20 MHz. Larger channels may be formed through channel bonding. For example, PPDUs may be transmitted over physical channels having bandwidths of 40 MHz, 80 MHz, 160 MHz, or 320 MHz by bonding together multiple 20 MHz channels.

[0044] FIG. 2 is a block diagram 200 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.

[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-transi tory computer readable mediums. Memory 230 / 280 may store computer program instructions or code that may be executed by processor 220 / 270 to carry out one or more of the operations / embodiments discussed in the present application. Memory 230 / 280 may be implemented (or positioned) within processor 220 / 270 or external to processor 220 / 270. Memory 230 / 280 may be operatively connected to processor 220 / 270 via various means known in the art.

[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] Target wake time (TWT), a feature introduced in the IEEE 802.11 ah standard, allows STAs to manage activity in the BSS by scheduling STAs to operate at different times to reduce contention. TWTs may allow STAs to reduce the required amount of time that a STA utilizing a power management mode may be awake. TWTs may be individual TWTs orbroadcast TWTs. Individual TWTs follow a negotiated TWT agreement between STAs. Broadcast TWTs are based on a schedule set and provided to STAs by an AP.

[0049] In an individual TWT, a STA that requests a TWT agreement is called a TWT requesting STA. The TWT requesting STA may be a non-AP STA for example. The STA that responds to the request is called a TWT responding STA The TWT responding STA may be an AP for example. The TWT requesting STA is assigned specific times to wake up and exchange frames with the TWT responding STA. The TWT requesting STA may communicate wake scheduling information to the TWT responding STA. The TWT responding STA may transmit TWT values to the TWT requesting STA when a TWT agreement is established between them.

[0050] When explicit TWT is employed, the TWT requesting STA may wake up and perform a frame exchange. The TWT requesting STA may receive a next TWT information in a response from the TWT responding STA. When implicit TWT is used, the TWT requesting STA may calculate a next TWT by adding a fixed value to the current TWT value.

[0051] The TWT values for implicit TWT may be periodic. The TWT requesting STA operating with an implicit TWT agreement may determine a next TWT service period (TWT SP) start time by adding a value of a TWT wake interval associated with the TWT agreement to the value of the start time of the current TWT SP. The TWT responding STA may include the start time for a series of TWT SPs corresponding to a single TWT flow identifier of an implicit TWT agreement in a target wake time field of a TWT element. The TWT element may contain a value of 'accept TWT’ in a TWT setup command field. The start time of the TWT SP series may indicate the start time of a first TWT SP in the series. Start times of subsequent TWT SPs may be determined by adding the value of the TWT wake interval to the start time of the current TWT SP. In an example, the TWT requesting STA, awake for an implicit TWT SP, may enter a doze state after the TWTSP has elapsed or after receiving an end of service period (EOSP) field equal to 1 from the TWT responding STA, whichever occurs first.

[0052] A TWT session may be negotiated between an AP and a STA. The TWT session may configure a TWT SP of DL and UL traffic between the AP and the STA. Expected traffic may be limited within the negotiated SP. The TWT SP may start at a specific time. The TWT SP may run for a SP duration. The TWT SP may repeat every SP interval.

[0053]

[0054] FIG. 3 illustrates an example MRTT frame 300 which may be used in a TXS procedure. As shown in FIG. 3, example MRTT frame 300 may comprise a frame control field, a duration field, a receiver address (RA) field, a transmitter address (TA) field, a common info field, a user info list field, a padding field, and / or frame check sequence (FCS) field.

[0055] In an example, the common info field may be a high-efficiency (HE) variant common info field or an extremely high throughput (EHT) variant common info field. An EHT variant common info field may comprise, as shown in FIG. 3, one or more of the following subfields: trigger type, UL length, more TF, CS required, UL BW, Gl and HE / EHT-LTF Type / Triggered TXOP sharing mode, number of HE / EHT-LTF symbols, LDPC extra symbol segment, AP Tx Power, Pre- FEC padding factor, PE disambiguity, UL spatial reuse, HE / EHT P160, special user info field flag, EHT reserved, reserved, or trigger dependent common info.

[0056] The trigger type subfield indicates that frame 300 is an MRTT frame.

[0057] The Gl and HE / EHT-LTF Type / Triggered TXOP sharing mode subfield may include a triggered TXOP sharing mode subfield. In an example, the triggered TXOP sharing mode subfield may be set to a non-zero value (e.g., 1 or 2). In an example, the triggered TXOP sharing mode subfield may be set to one (1). As such, the triggered TXOP sharing mode subfield may indicate that a STA indicated by an AID12 subfield of a user info field (of the user info list field) may transmit one or more non-TB PPDUs to the AP during a time indicated in the allocation duration subfield of the user info field. In another example, the triggered TXOP sharing mode subfield may be set to 2. As such, the triggered TXOP sharing mode subfield may indicate that a STA indicated by an AID12 subfield of a user info field (of the user info list field) may transmit one or more non-TB PPDUs to the AP or to a peer STA during the time indicated by the allocation duration subfield of the user info field. In an example, the peer STA may be a STA with a connection for P2P communication or direct communication with the STA.

[0058] The user info list field may include one or more user info fields. In an example, an EHT variant user info field may comprise, as shown in FIG. 3, one or more of the following subfields: AID12, RU allocation, allocation duration, reserved, or PS160.

[0059] The AID12 subfield may indicate an association identifier (AID) of a STA that may use a time indicated by the allocation duration subfield.

[0060] The RU allocation subfield may indicate the location and size of the RU allocated for a STA indicated by the AID12 subfield.

[0061] The allocation duration subfield may indicate a time allocated by an AP transmitting MRTT frame 300. The allocated time may be a portion a TXOP obtained by the AP. In an example embodiment, the allocation duration subfield may indicate a first time period.

[0062] FIG. 4 illustrates an example 400 of a TXS procedure (Mode =1). As shown in FIG. 4, the TXS procedure may begin by an AP 410 transmitting an MRTT frame 420 to a STA 411 . MRTT frame 420 may allocate a portion of a TXOP obtained by AP 410 to STA 411 and may indicate a TXS mode equal to 1 . STA 411 receiving MRTT frame 420 may use the allocated time to transmit one or more non-TB PPDUs to AP 410. The one or more non-TB PPDUs may comprise a data frame, a control frame, a management frame, or an action frame.

[0063] In an example, MRTT frame 420 may comprise a triggered TXOP sharing mode subfield that indicates the TXS mode and / or subfield that indicates a first time period corresponding to the allocated time. In an example, the first time period may be set to a value of X microseconds (us).

[0064] STA411 may respond to MRTT frame 420 by transmitting a CTS frame 421 to AP 410 Subsequently, STA 411 may transmit non-TB PPDUs 422, 424 comprising one or more data frame to AP 410 during the first time period indicated in MRTT frame 420. In an example, AP 410 may transmit one or more BA frames 423, 425 in response to the one or more data frames contained in non-TB PPDUs 422, 424 received from STA 411 .

[0065] FIG. 5 illustrates an example 500 of a TXS procedure (Mode =2). As shown in FIG. 5, the TXS procedure may begin by an AP 510 transmitting an MRTT frame 520 to a STA 511 . MRTT frame 520 may allocate a portion of a TXOP obtained by AP 510 to STA 511 and may indicate a TXS mode equal to 2. STA 511 receiving MRTT frame 520 may use the allocated time to transmit one or more non-TB PPDUs to STA 512. The one or more non-TB PPDUs may comprise a data frame, a control frame, a management frame, or an action frame.

[0066] In an example, MRTT frame 520 may comprise a triggered TXOP sharing mode subfield that indicates the TXS mode and / or subfield that indicates a first time period corresponding to the allocated time. In an example, the first time period may be set to a value of X microseconds (us).

[0067] STA511 may respond to MRTT frame 520 by transmitting a CTS frame 521 to AP 510. Subsequently, STA 511 may transmit non-TB PPDUs 522, 524 comprising one or more data frame to STA 512 during the first time period indicated in MRTT frame 520. In an example, STA 512 may transmit one or more BA frames 523, 525 in response to the one or more data frames contained in non-TB PPDUs 522, 524 received from STA 511 .

[0068] FIG. 6 is an example 600 that illustrates an example TXS procedure between multi-link devices (MLDs). As shown in FIG. 6, example 600 includes an AP MLD 602 and a non-AP MLD 604. An AP 602-1 and an AP 602-2 may be affiliated with AP MLD 602. A STA 604-1 and a STA 604-2 may be affiliated with non-AP MLD 604. STA 604-1 may be associated with AP 602-1. AP 602-1 and STA 604-1 may communicate over a first link (link 1). STA 604-2 may be associated with AP 602-2. AP 602-2 and STA 604-2 may communicate over a second link (link 2).

[0069] In an example, AP 602-1 may transmit an MU-RTS TXS Trigger (MRTT) frame 606 to STA 604-1 on link 1. MRTT frame 606 may comprise a TXOP sharing mode subfield set to 1 , an AID12 subfield set to an AID of STA 604-1, and / or a first time period (e.g ., X us, where X is an integer value larger than 0).

[0070] In an example, STA 604-1 may transmit a CTS frame 608 in response to MRTT frame 606 on link 1. Subsequently, STA 604-1 may transmit a data frame 610 (e.g., in a non-TB PPDU) to AP 602-1 on link 1 during the first time period. AP 602-1 may transmit a BA frame 613 in response to data frame 610 on link 1 during the first time period.

[0071] In an example, AP 602-2 may transmit an MRTT frame 614 to STA 604-2 on link 2. MRTT frame 614 may comprise a TXOP sharing mode subfield set to 1, an AID12 subfield set to an AID of STA 604-2, and / or a first time period (e.g., Y us, where Y is an integer value larger than 0).

[0072] In an example, STA 604-2 may transmit a CTS frame 616 in response to MRTT frame 614 on link 2. Subsequently, STA 604-2 may transmit a data frame 618 (e.g., in a non-TB PPDU) to AP 602-2 on link 2 during the first time period. AP 602-2 may transmit a BA frame 620 in response to data frame 618 on link 2 during the first time period (e.g., Y us).

[0073] FIG. 7 is an example 700 that illustrates an inefficient STA operation that may occur during a TXS procedure. As shown in FIG. 7, example 700 includes an AP 702 and STAs 704, 706, and 708. STA 704 may be associated with AP 702.

[0074] In an example, AP 702 may allocate a portion of an obtained TXOP to STA 704 by transmitting an MRTT frame 710. STA 704 may transmit a CTS frame 712 to AP 702 in response to MRTT frame 710.

[0075] MRTT frame 710 may comprise a TXOP sharing mode subfield, an AID12 subfield set to an AID of STA 704, and / or a first time period (e.g., X us).

[0076] In an example, the first time period may indicate a portion of time allocated by AP 702 within an obtained TXOP. In an example, the first time period may be indicated by a subfield (e.g., an allocation duration field) in MRTT frame 710. In an example, the first time period may be set to a value of X us.

[0077] In an example, the TXOP sharing mode subfield is set to 2. The TXOP sharing mode subfield set to 2 indicates that STA 704 may transmit one or more non-TB PPDUs to AP 702 or to a peer STA during the first time period. In an example, the peer STA may be a STA having a connection for P2P communication or direct communication with STA 704. In an example, the peer STA may be STA 706. The one or more non-TB PPDUs may comprise a data frame, a control frame, a management frame, or an action frame. In example 700, STA 704 may transmit a data frame 714 to STA 706 during the first time period. STA 706 may transmit a BA frame 716 to STA 704 in response to data frame 714. STA 704 may then transmit a data frame 718 to STA 706. STA 706 may respond to data frame 718 with a BA frame 720.

[0078] After receiving MRTT frame 710, STA 708 may be in an awake state during the first time period (X) indicated in MRTT frame 710. However, during this first time period, AP 702 may not communicate with STA 708 as STA 708 is not allocated by MRTT frame 710. The awake power state of STA 708 may thus result in power being unnecessarily wasted at STA 708.

[0079] FIG. 8 is an example 800 that illustrates an example TXS PS (PS) mode that may be used to address potential waste during some awake states. As shown in FIG. 8, example 800 includes an AP 802 and STAs 804, 806, and 808. One or more of STAs 804, 806, and 808 may be associated with AP 802.

[0080] As shown in FIG. 8, example 800 may begin with AP 802 transmitting a first frame 810 to allocate a portion of an obtained TXOP to STA 804. Frame 810 may comprise a TXOP sharing mode subfield, an AID 12 subfield, and a first time period (e.g ., X us). The TXOP sharing mode subfield may indicate a triggered TXOP sharing procedure. For example, the TXOP sharing mode subfield may be set to a non-zero value (e.g., 1, 2, ...) which indicates the triggered TXOP sharing mode 1 or the triggered TXOP sharing mode 2. The AID 12 subfield may be set to the AID of a STA that may use the first time period for transmitting and receiving one or more frame. For example, the AID 12 subfield field may be set to the AID of STA 804. The first time period may be specified in units of microseconds or some other unit of time. In an example, frame 810 may be an MRTT frame.

[0081] On receiving frame 810, STA 804 may transmit a second frame 812 to AP 802. In an example, frame 812 may be a CTS frame. STA 804 may subsequently transmit one or more non-TB PPDUs comprising one or more data frames 814 and 818 to STA 806 during the first time period. STA 806 may transmit one or more BA frames 816 and 820 to STA 804 in response to data frames 814 and 818 respectively.

[0082] In an implementation, based on receiving frame 810 which does not allocate STA 808 during the first time period, STA 808 may transition to a doze state. In an example embodiment, STA 808 may transition to the doze state: after STA 808 receives frame 810 and before STA 808 receives frame 812 in response to frame 810; after STA 808 receives frame 812 in response to frame 810; or if STA 808 does not receive a third frame during a second time period after STA 808 receives frame 810.

[0083] The third frame may be a data frame, a control frame, or a management frame. A value of the second time period may be a fixed value or may be signaled by a fourth frame sent by AP 802. The fourth frame may be a beacon frame, a probe response frame, or an association response frame.

[0084] In an implementation, STA 808 may maintain the doze state during a portion of the first time period after STA 808 transitions to the doze state. In an implementation, STA 808 may be in an awake state at the end of the first time period or at least from the end of the first time period.

[0085] In an implementation, AP 802 may not transmit a third frame 822 to STA 808 during the first time period. AP 802 may transmit third frame 822 to STA 808 after the first time period.

[0086] In an implementation, AP 802 and STA 808 may exchange indications of support of the TXS Power save (PS) mode prior to the beginning of example 800. For example, STA 808 may include an indication of support of the TXS PS mode in an association request frame to AP 802. STA 808 may set a TXS PS mode field (or a TXS PS Support field) to 1 in the association request frame to indicate support of the TXS PS mode. The TXS PS mode field (or TXS PS Support field) may be provided in an EHT MAC Capabilities Information field of the association request frame. AP 802 may include an indication of support of the TXS PS mode in an association response frame to STA 808. STA 808 may seta TXS PS mode field (or a TXS PS Support field) to 1 in the association response frame to indicate support of the TXS PS mode. The TXS PS mode field (or TXS PS Support field) may be provided in an EHT MAC Capabilities Information field of the association response frame.

[0087] In an implementation, when STA 808 indicates support of the TXS PS mode (e.g. , TXS PS field set to 1 in the association request frame to AP 802), AP 802 may refrain from transmitting to STA 808 during the first time period (in which STA 808 is not allocated) because STA 808 may enter the doze state during the first time period (even if STA 808 does not actually enter the doze state during the first time period). AP 802 may continue to use this behavior with respect to STA 808 for any subsequent TXS time period during which STA 808 is not allocated. That is, based on STA 808 having indicated support of the TXS PS mode, AP 802 may not transmit to STA 808 during TXS time periods in which STA 808 is not allocated.

[0088] Recently, however, it has been proposed in the 802.11 be standard amendment that a STA may return to the AP any remaining time of a time period allocated to the STA (in TXS sharing mode 2) after the STA has finished transmitting its buffered traffic. The AP may use the remaining time of the time period to transmit downlink traffic or may allocate a portion of the remaining time to another STA. For example, referring to FIG. 8, assuming that STA 804 has no more traffic to transmit after transmitting data frame 818, STA 804 may return the remaining time of the first time period after receiving BA frame 820 from STA 806. AP 802 may use the remaining time of the first time period to transmit downlink traffic (e.g., to STA 806 or 808) or may allocate a portion of the remaining time (e.g., to STA 806 or 808). According to the IEEE 802.11 be standard amendment, an AP that supports this “TXOP Return” feature may transmit to an associated STA an EHT MAC Capabilities Information field with a “TXOP Return Support In TXOP Sharing Mode 2” subfield set to 1. This indicates that the AP supports receiving, from a STA allocated in TXS sharing mode 2, a frame (e.g., quality of service (QoS) Data or QoS Null frame) that includes an HE variant HT Control field with a CAS Control subfield with the RDG / More PPDU subfield equal to 0. The AP may transmit a PPDU a SIFS after receiving the frame with the CAS Control subfield. Conversely, a STA that receives an MRTT frame with the TXOP sharing mode subfield equal to 2 may transmit, within an allocated time, a QoS Data or QoS Null frame that includes an HE variant HT Control field with a CAS Control subfield with the RDG / More PPDU subfield equal to 0 to the associated AP from which it has received an EHT Capabilities element with the “TXOP Return Support In TXOP Sharing Mode 2” subfield set to 1.

[0089] But, according to existing behavior, an AP may not use returned remaining time of a time period to transmit to, or to allocate a portion of the remaining time to, a STA that indicated support of the TXS PS mode and that was not allocated in the time period. Indeed, as described above, when a STA indicates support of the TXS PS mode and is not allocated during a time period, the AP may not transmit to the STA during the time period because the STA may enter the doze state during the time period. For example, referring to FIG. 8, assuming that STA 808 indicated support of the TXS PS mode to AP 802 (e.g., TXS PS field set to 1 in an association request frame to AP 802), AP 802 may not transmit to STA 808 during the first time period (in which STA 808 is not allocated) even if STA 804 were to return the remaining time of the first time period to AP 802 after receiving BA frame 820. Similarly, AP 802 may not allocate a portion of the returned remaining time to STA 808. This may occur even when STA 808 does not enter the doze state during the first time period.

[0090] This behavior may lead to inefficiencies as the AP may be limited in the ways it may use returned remaining time of a TXS time period. For example, the AP may have buffered downlink traffic for a STA that was not allocated inthe TXS time period and that has indicated support of the TXS PS mode. Although the STA may be in the awake state during the TXS time period, the AP must wait until the end of the TXS time period before it may transmit the buffered downlink traffic to the STA. In another example, the AP may wish to share a portion of the returned remaining time with the STA. But as the AP may not transmit to the STA during the TXS time period, the AP may not send the time allocation to the STA even though the STA may be in the awake state during the TXS time period.

[0091] FIG. 9 illustrates a first example 900, where the frame that indicates enabling or disabling of the TXS PS mode at the STA may be an association request frame or a reassociation request frame. As shown in FIG. 9, example 900 includes an AP 902 and STAs 904, 906, and 908. One or more of STAs 904, 906, and 908 may be associated with AP 902. STAs 904, 906, and / or 908 may support the TXS PS mode as described above.

[0092] As shown in FIG.9, example 900 may begin with STA 908 transmitting an association (or reassociation) request frame 910 to AP 902. In an example, association request frame 910 may comprise a TXS PS mode field (or a TXS PS Support field). In example 900, the TXS PS mode field (or TXS PS Support field) may be set to 1 to indicate enabling of the TXS PS mode at STA 908. The TXS PS mode field (or TXS PS Support field) may be provided in an EHT MAC Capabilities Information field of the association request frame. AP 902 may respond to association request frame 910 by transmitting an association response frame 912 to STA 908. In an example, association response frame 912 may comprise a TXS PS mode field (or a TXS PS Support field). In example 900, the TXS PS mode field (or TXS PS Support field) may be set to 1 to indicate support of the TXS PS mode at AP 902. The TXS PS mode field (or TXS PS Support field) may be provided in an EHT MAC Capabilities Information field of the association response frame.

[0093] Subsequently, AP 902 may transmit a frame 914 to allocate a portion of an obtained TXOP to STA 904. Frame 914 may comprise a TXOP sharing mode subfield, an AID 12 subfield, and a first time period (e.g. , X us). The TXOP sharing mode subfield may indicate a triggered TXOP sharing procedure. For example, the TXOP sharing mode subfield maybe set to a non-zero value (e.g., 1, 2, ...) which indicates the triggered TXOP sharing mode 1 or the triggered TXOP sharing mode 2. The AID 12 subfield may be set to the AID of a STA that may use the first time period for transmitting and receiving one or more frame. For example, the AID 12 subfield field may be set to the AID of STA 904. The first time period may be specified in units of microseconds or some other unit of time. In an example, frame 914 may be an MRTT frame.

[0094] On receiving frame 914, STA 904 may transmit a frame 916 to AP 902. In an example, frame 916 may be a CTS frame. STA 904 may subsequently transmit a non-TB PPDU comprising a data frame 918 to STA 906 during the first time period. STA 906 may transmit a BA frame 920 to STA 904 in response to data frame 918.

[0095] Based on receiving frame 914 which does not allocate STA 908 during the first time period, and the TXS PS mode being enabled at STA 908, STA 908 may transition to a doze state during the first time period. In accordance with the TX PS mode, STA 908 may transition to the doze state: after STA 908 receives frame 914 and before STA 908 receives frame 916 in response to frame 914; after STA 908 receives frame 916 in response to frame 914; or if STA 908 does not receive a third frame during a second time period after STA 908 receives frame 914. The third frame may be a data frame, a control frame, or a management frame. A value of the second time period may be a fixed value or may besignaled by a fourth frame sent by AP 902. The fourth frame may be a beacon frame, a probe response frame, or an association response frame.

[0096] In an implementation, STA 908 may maintain the doze state during a portion of the first time period after STA 908 transitions to the doze state. In an implementation, STA 908 may return to an awake state at the end of the first time period or at least from the end of the first time period. In an implementation, AP 902 may not transmit a frame to STA 908 during the first time period. AP 902 may transmit a frame to STA 908 after the first time period. In an example (not shown in FIG. 9), AP 902 may receive from STA 904, within the first time period, a frame indicating release or return of a remaining time of the first time period. The frame may comprise a QoS Data frame or a QoS Null frame that includes an HE variant HT Control field with a CAS Control subfield with the RDG / More PPDU subfield equal to 0. Based on the TXS PS mode being enabled at STA 908, AP 902 may wait for an end of the remaining time before transmitting a frame to STA 908. In an example, AP 902 may use the remaining time to transmit a frame to STA 904 or STA 906 (assuming STA 904 or STA 906 is in the awake state) or to another STA (not shown in FIG. 9, e.g., a legacy STA that does not support TXS PS mode). In another example, AP 902 may allocate a portion of the remaining time to STA 906.

[0097] In example 900, STA 908 may return to the awake state after the end of the first time period or at least from the end of the first time period. Subsequently, STA 908 may transmit an association (or reassociation) request frame 922 to AP 902. In an example, association request frame 922 may comprise a TXS PS mode field (or a TXS PS Support field). In example 900, the TXS PS mode field (or TXS PS Support field) may be set to 0 to indicate disabling of the TXS PS mode at STA 908. The TXS PS mode field (or TXS PS Support field) may be provided in an EHT MAC Capabilities Information field of association request frame 922. AP 902 may respond to association request frame 922 by transmitting an association response frame 924 to STA 908. In an example, association response frame 924 may comprise a TXS PS mode field (or a TXS PS Support field). In example 900, the TXS PS mode field (or TXS PS Support field) may be set to 1 to indicate support of the TXS PS mode at AP 902. The TXS PS mode field (or TXS PS Support field) may be provided in an EHT MAC Capabilities Information field of the association response frame.

[0098] Subsequently, AP 902 may transmit a frame 926 to allocate a portion of an obtained TXOP to STA 904. Frame 926 may comprise a TXOP sharing mode subfield, an AID 12 subfield, and a first time period (e.g., X us). The TXOP sharing mode subfield may indicate a triggered TXOP sharing procedure. For example, the TXOP sharing mode subfield maybe set to a non-zero value (e.g., 1, 2, ...) which indicates the triggered TXOP sharing mode 1 or the triggered TXOP sharing mode 2. The AID 12 subfield may be set to the AID of a STA that may use the first time period for transmitting and receiving one or more frame. For example, the AID 12 subfield field may be set to the AID of STA 904. The first time period may be specified in units of microseconds or some other unit of time. In an example, frame 926 may be an MRTT frame.

[0099] On receiving frame 926, STA 904 may transmit a frame 928 to AP 902. In an example, frame 916 may be a CTS frame. STA 904 may subsequently transmit a non-TB PPDU comprising a data frame 930 to STA 906 during the first time period. STA 906 may transmit a BA frame 932 to STA 904 in response to data frame 930.

[0100] On receiving frame 926 which does not allocate STA 908 during the first time period, and based on the TXS PS mode being disabled at STA 908, STA 908 may remain in the awake state during the first time period. In an example (not shown in FIG. 9), AP 902 may receive from STA 904, within the first time period, a frame indicating release or return of a remaining time of the first time period. The frame may comprise a QoS Data frame or a QoS Null frame that includes an HE variant HT Control field with a CAS Control subfield with the RDG / More PPDU subfield equal to 0. In an example, based on the TXS PS mode being disabled at STA 908, AP 902 may transmit a frame to STA 908 during the remaining time of the first time period. In another example, based on the TXS PS mode being disabled at STA 908, AP 902 may allocate a portion of the remaining time to STA 908. STA 908 may use the allocated portion of the remaining time to transmit to AP 902 or to another STA depending on the indicated TXS mode.

[0101] An advantage of the first example is that it reuses existing (re)association request / response frames (with minor modification) to enable a STA to signal enabling or disabling of the TXS mode to an AP. However, as (re)association request / response frames may be potentially large in size due to containing information regarding various capabilities supported by the STA / AP, the first example may result in increased signaling overhead. The construction of (re)association request / response frames may also require relatively large processing times at the STA / AP. The signaling by the STA, and the acknowledgment by the AP, of a TXS PS mode state change at the STA may thus require a substantial amount of time, leading to sub-optimal operation.

[0102] In another example, the frame that indicates enabling or disabling of the TXS PS mode at the STA may be separate from the frame that signals support of the TXS PS mode at the STA. In embodiments, the frame may be a QoS data frame, a QoS null frame, an action frame, a control frame, or a management frame. The frame may comprise an element or subfield indicating the enabling or disabling of the TXS PS mode at the STA. FIG. 10 is an example 1000 that illustrates such an embodiment. As shown in FIG. 10, example 1000 includes an AP 1002 and STAs 1004, 1006, and 1008. One or more of STAs 1004, 1006, and 1008 may be associated with AP 1002. STAs 1004, 1006, and / or 1008 may support the TXS PS mode as described above.

[0103] FIG. 10 illustrates an example that may begin with STA 1008 transmitting an association (or reassociation) request frame 1010 to AP 1002. In an example, association request frame 1010 may comprise a TXS PS mode field (or a TXS PS Support field). In example 1000, the TXS PS mode field (or TXS PS Support field) maybe set to 1 to indicate support of the TXS PS mode by STA 1008. The TXS PS mode field (or TXS PS Support field) may be provided in an EHT MAC Capabilities Information field of association request frame 1010.

[0104] In an implementation, support of the TXS PS mode by STA 1008 may include STA 1008 being able to perform a TXS PS mode operation in a defined condition. In an implementation, the TXS PS mode operation may comprise STA 1008 entering a doze state during a time period of a TXOP. The defined condition may comprise STA 1008 not being allocated by AP 1002 during the time period of the TXOP. In an implementation, support of the TXS PS mode by STA 1008 may include STA 1008 being able to transmit to an AP a frame indicating enabling or disabling of the TXS PS mode as described herein. In an embodiment, the frame may include a TXS PS (TPS) Control subfield (further described below) that indicates enabling or disabling of the TXS PS mode at STA 1008. The TPS Control subfield may include a TPSDisabling subfield that carries the indication of enabling or disabling of the TXS PS mode at STA 1008. In an implementation, support of the TXS PS mode by STA 1008 may include STA 1008 being capable of entering the doze state during a TXS time period that is not allocated to STA 1008 (e g., by an MRTT frame) when STA 1008 sets the TPS Disabling subfield to 0.

[0105] AP 1002 may respond to association request frame 1010 by transmitting an association response frame 1012 to STA 1008. In an example, association response frame 1012 may comprise a TXS PS mode field (or a TXS PS Support field). In example 1000, the TXS PS mode field (or TXS PS Support field) may be set to 1 to indicate support of the TXS PS mode by AP 1002. The TXS PS mode field (or TXS PS Support field) may be provided in an EHT MAC Capabilities Information field of association response frame 1012.

[0106] In an implementation, support of the TXS PS mode by AP 1002 may include AP 1002 being able to receive from a STA a frame indicating enabling or disabling of the TXS PS mode at the STA as described herein. In an embodiment, the frame may include a TPS Control subfield that indicates enabling or disabling of the TXS PS mode at the STA. The TPS Control subfield may include a TPS Disabling subfield that carries the indication of enabling or disabling of the TXS PS mode at the STA. In an implementation, support of the TXS PS mode by AP 1002 may further include AP 1002 being able to transmit to the STA an acknowledgment of the frame indicating enabling or disabling of the TXS PS mode at the STA. In an implementation, support of the TXS PS mode by AP 1002 may further include AP 1002 being capable of not transmitting (or refraining from transmitting) any frame, during a TXS time period, to a STA that sets the TPS Disabling subfield to 0 when the TXS time period is not allocated to the STA (e.g., by an MRTT frame).

[0107] Subsequently, in an example, STA 1008 may transmit a frame 1034 indicating enabling of the TXS PS mode at STA 1008. Frame 1034 maybe a QoS data frame, a QoS null frame, an action frame, a control frame, or a management frame. Frame 1034 may comprise an element or subfield that may be used to indicate enabling or disabling of the TXS PS mode at STA 1008.

[0108] In an example, frame 1034 may be a QoS data or a QoS null frame. The QoS data or QoS null frame may comprise an A-Control field that carries an indication of enabling or disabling the TXS PS mode at STA 1008. The A- Control field may be carried in an HT Control field of the QoS data frame or QoS null frame. In an embodiment, the A- Control field may comprise a TPS Control subfield. The TPS Control subfield may include a TPS Disabling subfield. The TPS Disabling subfield may be set to 0 to indicate enabling of the TXS PS mode at STA 1008 and may be set to 1 to indicate disabling of the TXS PS mode at STA 1008. The TPS Control subfield may further include Reserved bits.

[0109] In another example, frame 1034 may be an action frame. The action frame may comprise an element / field indicating enabling or disabling the TXS PS mode at STA 1008. In an example, the action frame may be an EML Operating Mode Notification frame. In an embodiment, the action frame may comprise a TPS Disabling subfield. The TPS Disabling subfield may be set to 0 to indicate enabling of the TXS PS mode at STA 1008 and may be set to 1 to indicate disabling of the TXS PS mode at STA 1008. The TPS Control subfield may further include Reserved bits.

[0110] In an implementation, AP 1002 may acknowledge frame 1034 by transmitting an acknowledgement frame 1036 to STA 1008. Acknowledgment frame 1036 may be an ACK frame or a BA frame.

[0111] Subsequently, AP 1002 may transmit a frame 1014 to allocate a portion of an obtained TXOP to STA 1004. Frame 1014 may comprise a TXOP sharing mode subfield, an AID 12 subfield, and a first time period (e.g., X us). The TXOP sharing mode subfield may indicate a triggered TXOP sharing procedure. For example, the TXOP sharing mode subfield may be set to a non-zero value (e.g . , 1, 2, ...) which indicates the triggered TXOP sharing mode 1 or the triggered TXOP sharing mode 2. The AID 12 subfield may be set to the AID of a STA that may use the first time period for transmitting and receiving one or more frame. For example, the AID 12 subfield field may be set to the AID of STA 1004. The first time period may be specified in units of microseconds or some other unit of time. In an example, frame 1014 may be an MRTT frame.

[0112] On receiving frame 1014, STA 1004 may transmit a frame 1016 to AP 1002. In an example, frame 1016 may be a CTS frame. STA 1004 may subsequently transmit a non-TB PPDU comprising a data frame 1018 to STA 1006 during the first time period. STA 1006 may transmit a BA frame 1020 to STA 1004 in response to data frame 1018.

[0113] Based on receiving frame 1014 which does not allocate STA 1008 during the first time period, and the TXS PS mode being enabled at STA 1008, STA 1008 may transition to a doze state during the first time period. In accordance with the TX PS mode, STA 1008 may transition to the doze state: after STA 1008 receives frame 1014 and before STA 1008 receives frame 1016 in response to frame 1014; after STA 1008 receives frame 1016 in response to frame 1014; or if STA 1008 does not receive a third frame during a second time period after STA 1008 receives frame 1014. The third frame may be a data frame, a control frame, or a management frame. A value of the second time period may be a fixed value or may be signaled by a fourth frame sent by AP 1002. The fourth frame may be a beacon frame, a probe response frame, or an association response frame.

[0114] In an implementation, STA 1008 may maintain the doze state during a portion of the first time period after STA 1008 transitions to the doze state. In an implementation, STA 1008 may return to an awake state at the end of the first time period or at least from the end of the first time period. In an implementation, AP 1002 may not transmit a frame to STA 1008 during the first time period. AP 1002 may transmit a frame to STA 1008 afterthe first time period. In an example (not shown in FIG. 10), AP 1002 may receive from STA 1004, within the first time period, a frame indicating release or return of a remaining time of the first time period. The frame may comprise a QoS Data frame or a QoS Null frame that includes an HE variant HT Control field with a CAS Control subfield with the RDG / More PPDU subfield equal to 0. Based on the TXS PS mode being enabled at STA 1008, AP 1002 may wait for an end of the remaining time before transmitting a frame to STA 1008. In an example, AP 1002 may use the remaining time to transmit a frame to STA 1004 or STA 1006 (assuming STA 1004 or STA 1006 is in the awake state) or to another STA (not shown in FIG. 10, e.g., a legacy STA that does not support TXS PS mode). In another example, AP 1002 may allocate a portion of the remaining time to STA 1006.

[0115] In example 1000, STA 1008 may return to the awake state after the end of the first time period or at least from the end of the first time period. Subsequently, STA 1008 may transmit a frame 1038 indicating disabling of the TXS PS mode at STA 1008. Frame 1038 may be a QoS data frame, a QoS null frame, an action frame, a control frame, or a management frame. Frame 1038 may comprise an element or subfield that may be used to indicate enabling or disablingof the TXS PS mode at STA 1008. In an example, frame 1038 may be a QoS data or a QoS null frame. The QoS data or QoS null frame may comprise an A-Control field that carries an indication of enabling or disabling the TXS PS mode at STA 1008. The A-Control field may be carried in an HT Control field of the QoS data frame or QoS null frame. In another example, frame 1038 may be an action frame. The action frame may comprise an element / field indicating enabling or disabling the TXS PS mode at STA 1008. In an example, the action frame may be an EML Operating Mode Notification frame.

[0116] In an implementation, AP 1002 may acknowledge frame 1038 by transmitting an acknowledgement frame 1040 to STA 1008. Acknowledgment frame 1040 may be an ACK frame or a BA frame.

[0117] Subsequently, AP 1002 may transmit a frame 1026 to allocate a portion of an obtained TXOP to STA 1004. Frame 1026 may comprise a TXOP sharing mode subfield, an AID 12 subfield, and a first time period (e.g., X us). The TXOP sharing mode subfield may indicate a triggered TXOP sharing procedure. For example, the TXOP sharing mode subfield may be set to a non-zero value (e.g., 1, 2, ...) which indicates the triggered TXOP sharing mode 1 or the triggered TXOP sharing mode 2. The AID 12 subfield may be set to the AID of a STA that may use the first time period for transmitting and receiving one or more frame. For example, the AID 12 subfield field may be set to the AID of STA 1004. The first time period may be specified in units of microseconds or some other unit of time. In an example, frame 1026 may be an MRTT frame.

[0118] On receiving frame 1026, STA 1004 may transmit a frame 1028 to AP 1002. In an example, frame 1016 may be a CTS frame. STA 1004 may subsequently transmit a non-TB PPDU comprising a data frame 1030 to STA 1006 during the first time period. STA 1006 may transmit a BA frame 1032 to STA 1004 in response to data frame 1030.

[0119] On receiving frame 1026 which does not allocate STA 1008 during the first time period, and based on the TXS PS mode being disabled at STA 1008, STA 1008 may remain in the awake state during the first time period. In an example (not shown in FIG. 10), AP 1002 may receive from STA 1004, within the first time period, a frame indicating release or return of a remaining time of the first time period. The frame may comprise a QoS Data frame or a QoS Null frame that includes an HE variant HT Control field with a CAS Control subfield with the RDG / More PPDU subfield equal to 0. In an example, based on the TXS PS mode being disabled at STA 1008, AP 1002 may transmit a frame to STA 1008 during the remaining time of the first time period. In another example, based on the TXS PS mode being disabled at STA 1008, AP 1002 may allocate a portion of the remaining time to STA 1008. STA 1008 may use the allocated portion of the remaining time to transmit to AP 1002 or to another STA depending on the indicated TXS mode.

[0120] Advantages of the other example illustrated in FIG. 10 include decreased signaling overhead and latency for a STA to signal to an AP a TXS PS mode state change at the STA. As described above, the TXS PS mode state change may be carried in various frame types and is not limited to association request frames. For example, the TXS PS mode state change may be carried in a QoS data / null frame or in a short action frame. The AP may respond to the frame from the STA with a short acknowledgement frame instead of a relatively large association response frame.

[0121] In yet another example, similar to the previous embodiment, an AP may solicit the TXS PS mode state at a STA. The STA may respond to the solicitation from the AP by transmitting to the AP a frame that indicates enabling or disablingof the TXS PS mode at the STA. In an embodiment, the AP may transmit to the STA a frame soliciting the TXS PS mode state at the STA before initiating a TXS operation. FIG. 11 is an example 1100 that illustrates such an embodiment. As shown in FIG. 11, example 1100 includes an AP 1102 and STAs 1104, 1106, and 1108. One or more of STAs 1104, 1106, and 1108 may be associated with AP 1102. STAs 1104, 1106, and / or 1108 may support the TXS PS mode as described above.

[0122] FIG. 11 illustrates an example 1100 of existing operation whereby a STA may enter a doze state during a time period of a TXOP. As shown in FIG. 11, example 1100 may begin with STA 1108 transmitting an association (or reassociation) request frame 1110 to AP 1102. In an example, association request frame 1110 may comprise a TXS PS mode field (or a TXS PS Support field). In example 1100, the TXS PS mode field (or TXS PS Support field) may be set to one (1) to indicate support of the TXS PS mode by STA 1108. The TXS PS mode field (or TXS PS Support field) may be provided in an EHT (or Ultra High Reliability (U HR)) MAC Capabilities Information field of association request frame 1110.

[0123] In an implementation, support of the TXS PS mode by STA 1108 may include STA 1108 being able to perform a TXS PS mode operation in a defined condition. In an implementation, the TXS PS mode operation may comprise STA 1108 entering a doze state during a time period of a TXOP. The defined condition may comprise STA 1108 not being allocated by AP 1102 during the time period of the TXOP. In an implementation, support of the TXS PS mode by STA 1108 may include STA 1108 being able to transmit to an AP a frame indicating enabling or disabling of the TXS PS mode as described herein. In an embodiment, the frame may include a TPS Control subfield that indicates enabling or disabling of the TXS PS mode at STA 1108. The TPS Control subfield may include a TPS Disabling subfield that carries the indication of enabling or disabling of the TXS PS mode at STA 1108. In an implementation, support of the TXS PS mode by STA 1108 may include STA 1108 being capable of entering the doze state during a TXS time period that is not allocated to STA 1108 (e.g., by an MRTT frame) when STA 1108 sets the TPS Disabling subfield to 0.

[0124] AP 1102 may respond to association request frame 1110 by transmitting an association response frame 1112 to STA 1108. In an example, association response frame 1112 may comprise a TXS PS mode field (or a TXS PS Support field). In example 1100, the TXS PS mode field (or TXS PS Support field) may be set to one (1) to indicate support of the TXS PS mode by AP 1102. The TXS PS mode field (or TXS PS Support field) may be provided in an EHT (or UHR) MAC Capabilities Information field of association response frame 1112.

[0125] In an implementation, support of the TXS PS mode by AP 1102 may include AP 1102 being able to receive from a STA a frame indicating enabling or disabling of the TXS PS mode at the STA as described herein. In an embodiment, the frame may include a TPS Control subfield that indicates enabling or disabling of the TXS PS mode at the STA. The TPS Control subfield may include a TPS Disabling subfield that carries the indication of enabling or disabling of the TXS PS mode at the STA. In an implementation, support of the TXS PS mode by AP 1102 may further include AP 1102 being able to transmit to the STA an acknowledgment of the frame indicating enabling or disabling of the TXS PS mode at the STA. In an implementation, support of the TXS PS mode by AP 1102 may further include AP 1102 beingcapable of not transmitting (or refraining from transmitting) any frame, during a TXS time period, to a STA that sets the TPS Disabling subfield to 0 when the TXS time period is not allocated to the STA (e.g. , by an MRTT frame).

[0126] Subsequently, in an example, AP 1102 may transmit to STA 1108 a frame 1138 soliciting the TXS PS mode state at STA 1108. Frame 1138 may be a control frame, a management frame, or an action frame. In an embodiment, AP 1102 may transmit frame 1138 to STA 1108 before initiating a TXS operation. In example 1100, STA 1108 may respond to frame 1138 by transmitting to AP 1102 a frame 1134 indicating enabling of the TXS PS mode at STA 1108. Frame 1134 may be a QoS data frame, a QoS null frame, an action frame, a control frame, or a management frame. Frame 1134 may comprise an element or subfield that may be used to indicate enabling or disabling of the TXS PS mode at STA 1108.

[0127] In an example, frame 1134 may be a QoS data or a QoS null frame. The QoS data or QoS null frame may comprise an A-Control field that carries an indication of enabling or disabling the TXS PS mode at STA 1108. The A- Control field may be carried in an HT Control field of the QoS data frame or QoS null frame In an embodiment, the A- Control field may comprise a TPS Control subfield.

[0128] In another example, frame 1134 may be an action frame. The action frame may comprise an element / field indicating enabling or disabling the TXS PS mode at STA 1108. In an example, the action frame maybe an EML Operating Mode Notification frame. In an embodiment, the action frame may have a format as illustrated in FIG. 20 described above.

[0129] In an implementation, AP 1102 may acknowledge frame 1134 by transmitting an acknowledgement frame 1136 to STA 1108. Acknowledgmentframe 1136 maybe an ACK frame ora BA frame. In additional or alternative embodiments, STA 1108 may transmit a frame 1134 without receiving frame 1138 from AP 1102, e.g., to indicate enabling of the TXS PS mode at STA 1108. In an example, STA 1108 may enable the TXS PS mode when STA 1108 receives acknowledgment frame 1136 from AP 1102 in response to frame 1134.

[0130] Subsequently, AP 1102 may transmit a frame 1114 to allocate a portion of an obtained TXOP to STA 1104. Frame 1114 may comprise a TXOP sharing mode subfield, an AID 12 subfield, and a first time period (e.g., X us). The TXOP sharing mode subfield may indicate a triggered TXOP sharing procedure. For example, the TXOP sharing mode subfield maybe set to a non-zero value (e.g., 1, 2, ...) which indicates the triggered TXOP sharing mode 1 or the triggered TXOP sharing mode 2. The AID 12 subfield may be set to the AID of a STA that may use the first time period for transmitting and receiving one or more frame. For example, the AID 12 subfield field may be set to the AID of STA 1104. The first time period may be specified in units of microseconds or some other unit of time. In an example, frame 1114 may be an MRTT frame.

[0131] On receiving frame 1114, STA 1104 may transmit a frame 1116 to AP 1102. In an example, frame 1116 may be a CTS frame. STA 1104 may subsequently transmit a non-TB PPDU comprising a data frame 1118 to STA 1106 during the first time period. STA 1106 may transmit a BA frame 1120 to STA 1104 in response to data frame 1118.

[0132] Based on receiving frame 1114 which does not allocate STA 1108 during the first time period, and the TXS PS mode being enabled at STA 1108, STA 1108 may transition to a doze state during the first time period. In accordance with the TX PS mode, STA 1108 may transition to the doze state: after STA 1108 receives frame 1114 and before STA1108 receives frame 1116 in response to frame 1114; after STA 1108 receives frame 1116 in response to frame 1114; or if STA 1108 does not receive a third frame during a second time period after STA 1108 receives frame 1114. The third frame may be a data frame, a control frame, or a management frame. A value of the second time period may be a fixed value or may be signaled by a fourth frame sent by AP 1102. The fourth frame may be a beacon frame, a probe response frame, or an association response frame.

[0133] In an implementation, STA 1108 may maintain the doze state during a portion of the first time period after STA 1108 transitions to the doze state. In an implementation, STA 1108 may return to an awake state at the end of the first time period or at least from the end of the first time period. In an implementation, AP 1102 may not transmit a frame to STA 1108 during the first time period. AP 1102 may transmit a frame to STA 1108 afterthe first time period. In an example (not shown in FIG. 11), AP 1102 may receive from STA 1104, within the first time period, a frame indicating release or return of a remaining time of the first time period. The frame may comprise a QoS Data frame or a QoS Null frame that includes an HE variant HT Control field with a CAS Control subfield with the RDG / More PPDU subfield equal to 0. Based on the TXS PS mode being enabled at STA 1108, AP 1102 may wait for an end of the remaining time before transmitting a frame to STA 1108. In an example, AP 1102 may use the remaining time to transmit a frame to STA 1104 or STA 1106 (assuming STA 1104 or STA 1106 is in the awake state) or to another STA (not shown in FIG. 11, e.g., a legacy STA that does not support TXS PS mode). In another example, AP 1102 may allocate a portion of the remaining time to STA 1106.

[0134] FIG. 12 illustrates an example 1200 of existing operation whereby a STA may enter a doze state during a TWT SP. As shown in FIG. 12, example 1200 includes an AP 1202 and a STA 1206. STA 1206 may be associated with AP 1202. In this example, STA 1206 can negotiate a specific target wake time (e.g., TWT SP 1250) with AP 1202 to wake up and be able to communicate with AP 1202, which may facilitate entry by STA 1206 into a low-power sleep mode (e.g., doze state 1230), thereby conserving battery life.

[0135] As shown in FIG. 12, example 1200 may begin during TWT SP 1250, with AP 1202 transmitting a downlink (DL) frame 1210-1 to STA 1206. In example 1200, DL frame 1210-1 may include an indication that the SP has not yet ended, e.g., end of service period (EOSP=0). STA 1206 may transmit BA frame 1220-1 to AP 1202 in response to DL frame 1210-1.

[0136] Subsequently, in example 1200, AP 1202 may transmit to STA 1206 another DL frame 1210-2, and DL frame 1210-2 may include an indication that the SP has ended, e.g., EOSP=1 . STA 1206 may transmit BA frame 1220-2 to AP 1202 in response to DL frame 1210-2. In this example of a TWT power saving operation, during TWT SP 1250, TWT scheduled STA 1206 may enter doze state 1230 when there is no indication of additional traffic from AP 1202, e.g., with a frame such as DL frame 1210-1 having the EOSP=1 indication discussed above, and / or an indication that more data is not forthcoming (MD=0). As depicted, in this example, doze state 1230 for STA 1206 lasts until the end of TWT SP 1250.

[0137] FIG. 13 illustrates an example 1300 that illustrates an example TXS procedure. As shown in FIG. 13, example 1300 includes AP 1310 and STAs 1311 and 1312 may be associated with AP 1310. As shown in FIG. 13, example 1300 may begin with AP 1310 transmitting an MRTT frame 1315 to allocate a portion of an obtained TXOP 1355 to STA 1311.MRTT frame 1315 specifies a TXOP sharing mode (e.g., TXS sharing mode 2 for communication between STAs 1311 and 1312), and an allocation duration of the portion of the TXOP allocated to STA 1311, e.g., shown in FIG. 13 as allocation duration 1365.

[0138] On receiving MRTT frame 1315, STA 1311 may transmit a CTS frame 1340 to AP 1310. STA 1311 may subsequently transmit one or more non-TB PPDUs to STA 1312, e.g., non-TB PPDUs 1360-1 and 1360-2. In this example, STA 1312 may transmit one or more BA frames 1320-1 and 1320-2 to STA 1311, in response to non-TB PPDUs 1360-1 and 1360-2, respectively.

[0139] In this example, for STA 1311, after receipt of BA 1320-2, STA has no additional frames to transmit to STA 1312. As depicted in FIG. 13, because STA 1311 is operating in TXS sharing mode 2, and has finished transmitting its buffered traffic during allocation duration 1365, and / or TXOP 1355, STA 1311 may return to the AP any remaining time of allocation duration 1365 allocated to STA 1311. As depicted, one approach to returning remaining allocated time is to transmit an indication to AP 1310 that the time is to be returned. In this example, the indication may be transmitted using a QoS data frame (not shown) or QoS null frame 1370.

[0140] In an implementation of the QoS null frame 1370, this frame includes an HE variant HT Control field with a CAS Control subfield, with the RDG / More PPDU subfield equal to 0 to the associated AP, e.g., AP 1310. Discussed in greater detail, the HE variant HT Control field may be a field within the MAC header of QoS null frame 1370 that includes control information specific to High Efficiency (HE) operations, and “HT” refers to High Throughput (as introduced with 802.11n). The HE variant HT Control field specifies that the frame structure supports HT features but is extended or variant to support HE capabilities. The HT Control field with a CAS Control subfield refers to a command and status (CAS) control subfield of the HT control field. RDG stands for “Reverse Direction Grant,” which is an operation that specifies that the recipient of the frame may respond without having to contend for the medium again. Because, in this example, RDG / More PPDU subfield is set to zero (0), this indicates that this mechanism is not in use for QoS null frame 1370, and there are no more PPDUs to be sent immediately in the reverse direction after the QoS null frame 1370 is received.

[0141] In this example, notwithstanding the indication communicated with QoS null frame 1370 and the acknowledgement frame 1330 from AP 1310, there is no provision for enabling STA 1311 to enter a doze state, e.g., as shown with doze state 1230 described with FIG. 12 above. As such, as depicted in FIG. 13, STA 1311 does not enter a low-power mode for the remainder of TXOP 1355, e.g., STA 1311 remains in awake state 1335 until the end of TXOP 1355.

[0142] In this example, because TXS assigned STA 1311 will be in awake state 1335 during the remaining TXS allocation duration 1365 or the remaining TXOP 1355, power consumption of the TXS assigned STA 1311 will be increased, e.g., especially when there is no DL / UL traffic for TXS assigned STA 1311 as depicted in FIG. 13.

[0143] Embodiments of the present disclosure, as further described below, address the above-described problem of existing TXS operation. In one aspect, a STA may receive from an AP a first frame indicating a first time period of a TXOP, allocated to the STA and a sharing mode of the first time period. The STA may transmit to the AP, during the first time period, a second frame indicating a return by the STA of the first time period to the AP. After transmitting the secondframe, the STA may transition from a first power state to a second power state based on the sharing mode in a power save mode. In another embodiment, after transmitting the second frame, the STA may be unavailable in an active mode, e.g., from a first power state entered based on the sharing mode. In this example context, a STA that is unavailable is not capable of receiving PPDUs. In an embodiment, the first power state corresponds to an awake state for the STA in a power save mode or an active mode, and the second power state corresponds to a doze state for the STA in a power save mode, the second power state corresponds to the STA being unavailable in an active mode, or the second power state corresponds to a listen state for the STA in a power save mode. In an embodiment, the STA may transition from the first power state to the second power state based on the sharing mode being a mode according to which the STA may communicate with a peer STA (e.g., TXS sharing mode 2). The STA may as such avoid unnecessarily and wastefully remaining in an awake state after returning the first time period to the AP.

[0144] FIG. 14 illustrates an example 1400 of one or more embodiments that may utilize a power saving operation during a TXS procedure. As shown in FIG. 14, example 1400 includes AP 1410 and STAs 1411 and 1412 associated with AP 1410. Example 1400 may begin with AP 1410 transmitting an MRTT frame 1415 to specify allocation duration 1465 of obtained TXOP 1455 to be allocated to STA 1411. In this example, MRTT frame 1415 specifies a TXOP sharing mode of 2 (e.g., for communication between STAs 1411 and 1412), and a value corresponding to allocation duration 1465.

[0145] On receiving MRTT frame 1415, STA 1411 may transmit CTS frame 1440 to AP 1410. In accordance with allocation duration 1465, STA 1411 may subsequently transmit non-TB PPDUs 1460-1 and 1460-2 to STA 1412, with STA 1412 transmitting one or more BA frames 1420-1 and 1420-2 to STA 1411, in response to non-TB PPDUs 1460-1 and 1460-2, respectively. In one or more embodiments, to indicate to AP 1410 that no additional data is to be communicated by STA 1411 to STA 1412, QoS null frame 1470 may be communicated to AP 1410 by STA 1411. In response to QoS null frame 1470, AP 1410 may respond with acknowledgement frame 1435.

[0146] Continuing this example embodiment, after communication of QoS null frame 1470 to AP 1410, and receipt by STA 1411 of an acknowledgment frame 1435 from AP 1410, STA 1411 may enter a second power state (e.g., a doze state) during a remaining duration of allocation duration 1465 (depicted as doze state 1430-1 in FIG. 14) or of TXOP 1455 (depicted as doze state 1430-2 in FIG. 14). Thus, one or more embodiments may address the above-described problems may be associated with a TXS assigned STA unnecessarily and wastefully remaining in an awake state, e.g., as discussed with FIG. 13 above.

[0147] As implemented, one or more embodiments may facilitate entering one of doze states 1430-1 and 1430-2 (hereinafter collectively called “doze states 1430”) based on one or more combinations of conditions, e.g., conditions that promote improved operation of the network. For example, to facilitate use of doze states 1430 by embodiments, STA 1411 is scheduled by MRTT frame 1415 addressed to STA 1411. To further facilitate use of doze states 1430, STA 1411 indicated a return of the remaining TXS allocation duration to AP 1410, e.g., by communicating QoS null frame 1470 to AP 1410.

[0148] In another example embodiment of a STA operating in accordance with the disclosure herein, example 1400 can begin with a STA (e.g., STA 1411) receiving from an AP (e.g., AP 1410), a first frame (e.g., MRTT frame 1415), indicating a first time period of a TXOP allocated to the STA (e.g., allocation duration 1465) and a sharing mode of the first period (e.g., TXS sharing mode 2). Continuing this example, the STA may transmit a second frame during the time period (e.g., QoS null frame 1470) indicating a return by the STA of the first time period to the AP.

[0149] In another aspect of this example, after transmitting the second frame, the STA may transition from a first power state (e.g., STA 1411 in an active state) to a second power state (e.g., STA 1411 entering one of doze states 1430), based on the sharing mode (e.g., TXS sharing mode 2). In an implementation, the first power state may correspond to an awake state for the STA in a power save mode or in an active mode, and the second power state may correspond to a doze state of the power save mode.

[0150] In an example embodiment of an AP operating in accordance with the disclosure herein, example 1400 can begin with the AP (e.g., AP 1410) transmitting to a STA (e.g., STA 1411), a first frame indicating a first time period, of a TXOP (e.g., allocation duration 1465 of TXOP 1455), allocated to the STA, and a sharing mode of the first time period (e.g., TXS sharing mode 2). Continuing this AP example, example 1400 may include receiving, by the AP from the STA and during the first time period, a second frame (e.g., QoS null frame 1470 or a QoS data frame) indicating a return by the STA of the first time period to the AP. In additional embodiments, QoS null frame 1470 (or the QoS data frame) may include an HE variant HT Control field with a CAS Control subfield with the RDG / More PPDU subfield equal to 0.

[0151] Based on the sharing mode (e.g., TXS sharing mode 2) and the second frame, the AP may receive from STA 1411, during the first time period, a third frame comprising a first indication that STA 1411 is transitioning (or has transitioned) from the first power state (e.g., STA 1411 in an active state) to a second power state (e.g., STA 1411 entering one of doze states 1430).

[0152] As discussed further with FIGS. 15-19 below, in an implementation, based on the use of doze states 1430 in accordance with one or more embodiments, AP 1410 may be limited in different combinations of operations that may be performed by AP 1410 during the time that STA 1411 is in doze states 1430. For example, in accordance with one or more embodiments, AP 1410 may be restricted from transmitting to STA 1411, any frame during the remaining duration of either allocation duration 1465 (e.g., for doze state 1430-1) or TXOP 1455 (e.g., for doze state 1430-2). Continuing the example embodiment of the AP discussed above, AP 1410 may be restricted from transmitting any frame to STA 1411 during the remaining duration of allocation duration 1465 and / or TXOP 1455. With the end of allocation duration 1465 and / or TXOP 1455, AP 1410 may not be restricted in transmission of any frames to STA 1411.

[0153] In an alternative embodiment, after communication of QoS null frame 1470 to AP 1410, and receipt by STA 1411 of acknowledgment frame 1435 from AP 1410, STA 1411 may enter the second power state corresponding to being unavailable during a remaining duration, e.g., the remaining duration of allocation duration 1465 or TXOP 1455. In this context, a STA that is unavailable is not capable of receiving PPDUs.

[0154] FIG. 15 illustrates an example 1500 of one or more embodiments that may utilize a power saving operation during a TXS procedure. As shown in FIG. 15, example 1500 includes AP 1510 and STAs 1511 and 1512 may be associated with AP 1510.

[0155] Example 1500 may begin with AP 1510 transmitting an MRTT frame 1515 to specify allocation duration 1565 of obtained TXOP 1555 to be allocated to STA 1511. In this example, MRTT frame 1515 specifies a TXOP sharing mode of 2 (e.g., for communication between STAs 1511 and 1512), a value corresponding to allocation duration 1565, and potentially, as discussed below, MRTT frame 1515 may include information corresponding to indication 1517-1 (TXS PS is allowed to be used).

[0156] On receiving MRTT frame 1515, STA 1511 may transmit CTS frame 1540 to AP 1510. In accordance with allocation duration 1565, STA 1511 may subsequently transmit non-TB PPDUs 1560-1 and 1560-2 to STA 1512, with STA 1512 transmitting one or more BA frames 1520-1 and 1520-2 to STA 1511, in response to non-TB PPDUs 1560-1 and 1560-2, respectively. In one or more embodiments, to indicate to AP 1510 that no additional data is to be communicated by STA 1511 to STA 1512, QoS null frame 1570 may be communicated to AP 1510 by STA 1511.

[0157] In additional or alternative embodiments, at different points in the sequence of communications between AP 1510 and STA 1511, AP 1510 may analyze different factors associated with whether STA 1511 should be permitted to enter the doze state. Example factors that may be evaluated as favoring permitting STA 1511 to enter the doze state include, but are not limited to, AP 1510 does not have buffered traffic for STA 1511 ; AP 1510 has non-low latency buffered traffic for STA 1511 and AP 1510 has low-latency buffered traffic for another STA associated with AP 1510; and / or AP 1510 has buffered traffic for STA 1511, but AP 1510 has more urgent traffic than the buffered traffic for another STA associated with AP 1510.

[0158] In some implementations, an approach to communicating the determination may utilize a frame communicated from AP 1510 to STA 1511, e.g., one or more of a trigger frame, an immediate response frame (e.g., an Ack frame or BlockAck (BA) frame), a control frame, a management frame, an action frame, a QoS data frame, and / or a QoS null frame. Examples that use MRTT frame 1515 and an immediate response frame (e.g., acknowledgement frame 1535) are described below. In one or more embodiments, when a trigger frame is utilized by embodiments described herein, the trigger frame can be an MRTT Trigger frame.

[0159] One example point in the sequence of communications between AP 1510 and STA 1511 includes a point before MRTT frame 1515 is communicated from AP 1510 to STA 1511. In this example, when a determination is made byAP 1510 to allow use of a TXS power saving operation by STA 1511, indication 1517-1 (TXS PS allowed) to STA 1511 may be included with MRTT frame 1515, and this indication may permit STA 1511 toentera doze state (e.g., doze state 1530- 1 or doze state 1530-2, hereinafter collectively referred to as “doze state 1530”) in accordance with embodiments described herein. Alternatively, when indication 1517-1 corresponds to a determination not to allow use of a doze state by STA 1511, this indication, included with MRTT frame 1515, may instruct STA 1511 to not enter a doze state (e.g., doze 1530-1 or doze state 1530-2) in accordance with embodiments described herein.

[0160] An alternative example point in the sequence of communications between AP 1510 and STA 1511 includes a point after QoS null frame 1570 is received by AP 1510 and before acknowledgement frame 1535 is communicated by AP 1510 to STA 1511 in response to QoS null frame 1570. In this example, additional information may be collected and analyzed by AP 1510 to determine whether to allow the use of the doze state 1530. As depicted, when the use of the power saving operations discussed herein is allowed, indication 1517-2 (TXS PS allowed) may be included with acknowledgement frame 1535, and the subsequent operation of STA 1511 is controlled in accordance with the indication.

[0161] One approach to including indication 1517-2 in acknowledgement frame 1535 (or a BA, not shown) may utilize the More data (MD) subfield of an Ack or BA frame. When this currently existing subfield is set to zero (0), this may be used to indicate to STA 1511 that no more data is to be provided by AP 1510 to STA 1511, and thus the use of doze state 1530 is permitted. Conversely, in accordance with one or more embodiments, the MD subfield of acknowledgement frame 1535 may be set to one (1) to indicate to STA 1511 that more data is to be provided by AP 1510 to STA 1511 , and thus the doze state 1530 is not permitted to be utilized.

[0162] Another approach to communicating information associated with the use of a TXS SP procedure to STA 1511 may utilize the Buffered Traffic Indication subfield of an immediate response frame, a control frame, a management frame, an action frame, and / or a QoS null / data frame. Yet another approach to communicating information associated with the use of a TXS SP procedure to STA 1511 may utilize the SIG field (e.g., U-SIG, UHR-SIG, etc.) of preamble of the PPDU carrying the field. These additional approaches are discussed in greater detail with FIG. 20 below.

[0163] FIG. 16 illustrates an example 1600 that utilizes a power saving operation during a TXS procedure in accordance with one or more embodiments. As shown in FIG. 16, example 1600 includes AP 1610 and STAs 1611 and 1612 may be associated with AP 1610. Example 1600 may begin with AP 1610 transmitting an MRTT frame 1615 to specify allocation duration 1665 of obtained TXOP 1655 to be allocated to STA 1611. In this example, MRTT frame 1615 specifies a TXOP sharing mode of 2 (e.g., for communication between STAs 1611 and 1612), and a value corresponding to allocation duration 1665.

[0164] On receiving MRTT frame 1615, STA 1611 may transmit CTS frame 1640 to AP 1610. In accordance with allocation duration 1665, STA 1611 may subsequently transmit non-TB PPDUs 1660-1 and 1660-2 to STA 1612, with STA 1612 transmitting one or more BA frames 1620-1 and 1620-2 to STA 1611, in response to non-TB PPDUs 1660-1 and 1660-2, respectively. In one or more embodiments, to indicate to AP 1610 that no additional data is to be communicated by STA 1611 to STA 1612, QoS null frame 1670 may be communicated to AP 1610 by STA 1611.

[0165] As noted above with FIG. 14, one or more embodiments may restrict operations of AP 1610 when STA 1611 is utilizing TXS power saving operations. To implement these restrictions, in additional or alternative embodiments depicted in FIG. 16, QoS null frame 1670 may be used by STA 1611 to further indicate to AP 1610 whether STA 1611 is entering a second power state (e.g., doze state 1630-1 or 1630-2 or an unavailable state) from a first power state (e.g., an awake state), during a remaining duration (e.g., of allocation duration 1665 or TXOP 1655). As depicted in FIG. 16, an indication 1671 (TXS PS notification) may be communicated to AP 1610 with QoS null frame 1670, and based on indication 1671,AP 1610 may determine not to transmit to STA 1611 any frame during the remaining duration of allocation duration 1665 or TXOP 1655.

[0166] Continuing this example, in response to QoS null frame 1670, AP 1610 may respond with acknowledgement frame 1635. After communication of QoS null frame 1670 to AP 1610, receipt of indication 1671 by AP 1610, and receipt by STA 1611 of acknowledgement frame 1635 from AP 1610, AP 1610 may restrict communication to STA 1611, and STA 1611 may enter a second power state (e.g., doze states 1630-1 or 1630-2 or an unavailable state) during a remaining duration (e.g., of allocation duration 1665 or TXOP 1655).

[0167] FIG. 17 illustrates an example 1700 of one or more embodiments that may utilize a power saving operation during a TXS procedure. As shown in FIG. 17, example 1700 includes AP 1710 and STAs 1711 and 1712 associated with AP 1710.

[0168] Example 1700 may begin with AP 1710 transmitting an MRTT frame 1715 to specify allocation duration 1765 of obtained TXOP 1755 to be allocated to STA 1711. In this example, MRTT frame 1715 specifies a TXOP sharing mode of 2 (e.g., for communication between STAs 1711 and 1712), a value corresponding to allocation duration 1765, and potentially, as discussed below, MRTT frame 1715 may include information corresponding to indication 1717 (TXS PS is allowed to be used).

[0169] On receiving MRTT frame 1715, STA 1711 may transmit CTS frame 1740 to AP 1710. In accordance with allocation duration 1765, STA 1711 may subsequently transmit non-TB PPDUs 1760-1 and 1760-2 to STA 1712, with STA 1712 transmitting one or more BA frames 1720-1 and 1720-2 to STA 1711, in response to non-TB PPDUs 1760-1 and 1760-2, respectively. In one or more embodiments, to indicate to AP 1710 that no additional data is to be communicated by STA 1711 to STA 1712, QoS null frame 1770 may be communicated to AP 1710 by STA 1711.

[0170] As discussed above with FIG. 17, in one or more embodiments, AP 1710 may analyze different factors associated with whether STA 1711 should be permitted to enter doze state 1730-1 or doze state 1730-2 (hereinafter collectively referred to as “doze state 1730”). Example factors that may be evaluated as favoring permitting STA 1711 to enter doze state 1730 include, but are not limited to, that AP 1710 does not have buffered traffic for STA 1711, that AP 1710 has non-low latency buffered traffic for STA 1711 , and that AP 1710 has low-latency buffered traffic for another STA associated with AP 1710, and / or that AP 1710 has buffered traffic for STA 1711, but AP 1710 has more urgent traffic than the buffered traffic for another STA associated with AP 1710.

[0171] In additional or alternative embodiments, at the time that QoS null frame 1770 is utilized by STA 1711 to indicate to AP 1710 that no additional data is to be communicated by STA 1711 to STA 1712, STA 1711 can utilize an indication 1771 to request to be allowed to utilize TXS power saving operation. At that time, based at least on the example factors described above, AP 1710 can determine whether to permit usage of TXS power saving operation by STA 1711 in response to indication 1771 (TXS PS request) included with QoS null frame 1770.

[0172] With respect to communicating determination information corresponding to indication 1717 to STA 1711, one or more embodiments can utilize approaches described with FIG. 15 above, e.g., an approach to communicating the determination may utilize a frame communicated from AP 1710 to STA 1511, including one or more of a trigger frame,an immediate response frame (e.g., an Ack frame or BlockAck (BA) frame), a control frame, a management frame, an action frame, a QoS data frame, and / or a QoS null frame. Examples that use an immediate response frame (e.g., acknowledgement frame 1735) are described with FIG. 15 above, and FIG. 20 below. The immediate response frame (e.g., acknowledgement frame 1735) may comprise indication 1717. In an embodiment, indication 1717 may be comprised in a separate frame with acknowledgement frame 1735. In an additional or alternative embodiment, indication 1771 may be comprised in a separate frame with QoS null frame 1770.

[0173] FIG. 18 illustrates an example 1800 of one or more embodiments that may utilize a power saving operation during a TXS procedure. As shown in FIG. 18, example 1800 includes AP 1810 and STAs 1811 and 1812 associated with AP 1810.

[0174] In one or more embodiments, a STA (or AP) may negotiate, with an AP (or STA), a capability to support different TXS power saving operations described with embodiments herein, e.g., STA 1811 may or may not have a capability of utilizing TXS power saving operations

[0175] To illustrate this exchange of capability information between AP 1810 and STA 1811, example 1800 begins with STA 1811 transmitting an association (or reassociation) request frame 1825 to AP 1810. Based on association request frame 1825, AP 1810 may respond with an association response frame 1827. In one or more embodiments, the existing capability fields of association request frame 1825 and association response frame 1827 may be used to exchange capability information associated with TXS power saving operations. For example, utilized capability fields may be included in one or more capabilities elements (e.g., HE capabilities element, EHT MAC capabilities element, UHR MAC capabilities element, etc.), in one or more management frames (e.g., beacon frame, probe request frame, probe response frame, association request frame, association response frame, etc.).

[0176] Alternative frames that can be utilized to provide the capabilities of STA 1811 include, but are not limited to, a probe request frame, an association request frame, a control frame, a management frame, an action frame, a QoS data frame, and / or a QoS null frame.

[0177] Alternative frames that can be utilized to provide capabilities of AP 1810 include, but are not limited to, a probe response frame, an association response frame, a broadcast addressed frame, a control frame, a management frame, an action frame, a QoS data frame, and / or a QoS null frame. In one or more embodiments, the broadcast addressed frame may be a beacon frame, a probe response frame, and / or a fast initial link setup (FILS) discovery frame.

[0178] Example 1800 continues with AP 1810 transmitting an MRTT frame 1815 to specify allocation duration 1865 of obtained TXOP 1855 to be allocated to STA 1811. In this example, MRTT frame 1815 specifies a TXOP sharing mode of 2 (e.g., for communication between STAs 1811 and 1812), and a value corresponding to allocation duration 1865.

[0179] On receiving MRTT frame 1815, STA 1811 may transmit CTS frame 1840 to AP 1810. In accordance with allocation duration 1865, STA 1811 may subsequently transmit non-TB PPDUs 1860 to STA 1812, and STA 1812 may respond by transmitting BA frame 1820 to STA 1811. In one or more embodiments, to indicate to AP 1810 that no additional data is to be communicated by STA 1811 to STA 1812, QoS null frame 1870 may be communicated to AP 1810 by STA 1811. In response to QoS null frame 1870, AP 1810 may respond with acknowledgement frame 1835.

[0180] Continuing this example embodiment, after communication of QoS null frame 1870 to AP 1810, and receipt by STA 1811 of acknowledgement frame 1835 from AP 1810, when STA 1811 is determined to have capabilities that support the TXS power saving operation, STA 1811 may enter the doze state during the remaining duration, and the AP 1810 should not transmit to the STA 1811 any frame during the remaining duration. Conversely, when the STA 1811 is not determined to have sufficient capabilities to support TXS power saving operations, STA 1811 may not enter doze state 1830-1 or doze state 1830-2 (hereinafter collectively referred to as “doze state 1830”), and AP 1810 may transmit a frame to STA 1811, during the remaining duration.

[0181] FIG. 19 illustrates an example 1900 of one or more embodiments that may utilize a power saving operation during a TXS procedure. As shown in FIG. 19, example 1900 includes AP 1910 and STAs 1911 and 1912 may be associated with AP 1910.

[0182] Example 1900 may begin with STA 1911 transmitting association request 1925 to AP 1910. Based on association request 1925, AP 1910 may respond with association response 1927. In one or more embodiments, to facilitate the use of TXS power saving operations by STA 1911, after receipt of association response 1927 by STA 1911, STA 1911 may transmit to the AP 1910, enabling frame 1980 that may include an indication of whether STA 1911 enables (activates) or disables (deactivates) the TXS power saving operation for the current communication session. For TXS power saving operations described herein, STA 1911 may enter doze state 1930-1 or doze state 1930-2 (hereinafter collectively referred to as “doze state 1930”) during a remaining TXS allocation duration 1965 (TXOP 1955) based on STA 1911 transmitting enabling frame 1980. Without enablement of TXS power saving operations by enabling frame 1980, STA 1911 may not enter the doze state during the remaining duration.

[0183] In TXS power saving operations described with embodiments herein, AP 1910 may transmit a frame to STA 1911 during the remaining time only when AP 1910 receives an indication via enabling frame 1980, that the TXS power saving operation is disabled. Otherwise, when enabling frame 1980 indicates that TXS power saving operations are to be enabled, AP 1910 may not transmit any frame to STA 1911 during the remaining time.

[0184] In an additional example, when AP 1910 receives enabling frame 1980, AP 1910 may transmita response frame (e.g„ response management ( / action) frame or immediate response frame (e.g„ Ack or BA)), e.g„ acknowledgement frame 1935-1 depicted in FIG. 19.

[0185] Example 1900 continues with AP 1910 transmitting an MRTT frame 1915 to specify allocation duration 1965 of obtained TXOP 1955, to be allocated to STA 1911. In this example, MRTT frame 1915 specifies a TXOP sharing mode of 2 (example, for communication between STAs 1911 and 1912), and a value corresponding to allocation duration 1965.

[0186] On receiving MRTT frame 1915, STA 1911 may transmit CTS frame 1940 to AP 1910. In accordance with allocation duration 1965, STA 1911 may subsequently transmit non-TB PPDU 1960 to STA 1912, and STA 1912 may respond by transmitting BA frame 1920 to STA 1911. In one or more embodiments, to indicate to AP 1910 that no additional data is to be communicated by STA 1911 to STA 1912, QoS null frame 1970 may be communicated to AP 1910 by STA 1911. In response to QoS null frame 1970, AP 1910 may respond with acknowledgement frame 1935-2.

[0187] Continuing this example embodiment, after communication of QoS null frame 1970 to AP 1910, and receipt by STA 1911 of acknowledgement frame 1935-2 from AP 1910, based on enabling frame 1980 indicating an enablement of TXS power saving operations, STA 1911 may enter a second power state (e.g., doze state 1930-1 or 1930-2) during a remaining duration (e.g., of allocation duration 1965 orTXOP 1955).

[0188] FIG. 20 illustrates an example 2000 of one or more embodiments that may utilize a power saving operation during a TXS procedure. As shown in FIG. 20, example 2000 includes AP 2010 and STAs 2011 and 2012 associated with AP 2010.

[0189] Example 2000 may begin with AP 2010 transmitting an MRTT frame 2015 to specify allocation duration 2065 of obtained TXOP 2055 to be allocated to STA 2011. In this example, MRTT frame 2015 specifies a TXOP sharing mode of 2 (e.g., for communication between STAs 2011 and 2012), a value corresponding to allocation duration 2065, and potentially, as discussed below, MRTT frame 2015 may include information corresponding to indication 2017 (a TXS power saving operation is allowed to be used).

[0190] On receiving MRTT frame 2015, STA 2011 may transmit CTS frame 2040 to AP 2010. In accordance with allocation duration 2065, STA 2011 may subsequently transmit non-TB PPDUs 2060-1 and 2060-2 to STA 2012, with STA 2012 transmitting one or more BA frames 2020-1 and 2020-2 to STA 2011, in response to non-TB PPDUs 2060-1 and 2060-2, respectively. In one or more embodiments, to indicate to AP 2010 that no additional data is to be communicated by STA 2011 to STA 2012, QoS null frame 2070 may be communicated to AP 2010 by STA 2011.

[0191] As discussed above with FIG. 20, in one or more embodiments, AP 2010 may analyze different factors associated with whether STA 2011 should be permitted to enter doze state 2030-1 or doze state 2030-2 (hereinafter, collectively referred to as “doze state 2030”). Example factors that may be evaluated as favoring permitting STA 2011 to enter doze state 2030 include, but are not limited to, that AP 2010 does not have buffered traffic for STA 2011, that AP 2010 has non-low latency buffered traffic for STA 2011, and that AP 2010 has low-latency buffered traffic for another STA associated with AP 2010, and / or that AP 2010 has buffered traffic for STA 2011, but AP 2010 has more urgent traffic than the buffered traffic for another STA associated with AP 2010.

[0192] In additional or alternative embodiments, at the time that QoS null frame 2070 is utilized by STA 2011 to indicate to AP 2010 that no additional data is to be communicated by STA 2011 to STA 2012, STA 2011 can utilize an indication 2071 to request to be allowed to utilize TXS power saving operations. At that time, based at least on the example factors described above, AP 2010 can determine whether to permit usage of TXS power saving operation by STA 2011 in response to indication 2071 (TXS PS request) included with QoS null frame 2070.

[0193] With respect to communicating determination information corresponding to indication 2017 to STA 2011, one or more embodiments can utilize approaches described with FIG. 15 above, e.g., an approach to communicating the determination may utilize a frame communicated from AP 2010 to STA 1511, including one or more of a trigger frame, an immediate response frame (e.g., an Ack frame or BlockAck (BA) frame), a control frame, a management frame, an action frame, a QoS data frame, and / or a QoS null frame. Examples that use an immediate response frame (e.g., acknowledgement frame 2035) are described with FIG. 15 above, and FIG. 21 below. In an embodiment, indication 2017may be comprised in a separate frame with acknowledgement frame 2035. In an additional or alternative embodiment, indication 2017 may be comprised in a separate frame with QoS null frame 2070.

[0194] In an embodiment, after STA 2011 receives an indication that TXS power saving operations are allowed, STA 2011 may transmit a confirmation indication to AP 2010. For example, as depicted, after receiving indication 2017 with acknowledgement frame 2035, STA 2011 transmits confirmation indication 2075 to AP 2010 to confirm receipt of the indication. In an example, confirmation indication may be a QoS Data frame, a QoS Null frame, or other frame that communicates similar information.

[0195] FIG. 21 describes an example 2100 of different signaling capabilities for one or more embodiments. In one or more embodiments, a TXS power save mode 2 Support subfield 2115 in an UHR MAC Capabilities element 2110 can be utilized using approaches described below. In an example where the STA supports the TXS power save mode 2, the STA may enter the doze state during a remaining duration within an TXS allocation duration or the current TXOP when one or more of the following conditions are met: when the STA transmits a first frame to return a remaining duration within an allocated duration, when the STA receives a response frame in response to the first frame, when the STA activates ( / enables) TXS power saving operation, when the STA transmits a second frame indicating that the STA enters the second power state (doze state) during the remaining duration, when the STA receives a third frame indicating that the STA is allowed to be in doze state (the second power state), and when the STA receives the third frame in response to the second frame. For example, for a non-AP STA, the UHR MAC Capabilities element 2110 may be carried in an association request frame or a probe request frame, and the TXS power save mode 2 Support subfield being set to one (1) indicates that the non-AP STA supports the TXS power save mode 2.

[0196] Foran AP, the UHR MAC Capabilities element 2110 may be carried in a beacon frame, an association response frame, or a probe response frame. The TXS power save mode 2 Support subfield 2115 being set to one (1) indicates that the AP supports TXS power save mode 2. In that case, the AP should not transmit any frame to a STA that is allowed to enter the doze state during a remaining duration within an TXS allocation duration or the current TXOP when one or more of the following conditions is met: when the AP receives a first frame to return a remaining duration within an allocated duration, when the AP transmits a response frame in response to the first frame, when the AP receives, from the STA, a frame to activate / enable TXS power saving operation, when the AP receives, from the STA, a second frame indicating that the STA enters the second power state (doze state) during the remaining duration, when the AP transmits a third frame indicating that the STA is allowed to be in doze state (the second power state), and when the AP transmits the third frame in response to the second frame.

[0197] In one or more embodiments, signaling values that correspond to the enabling and disabling of TXS power saving operations may be performed using different approaches. One option may use an A-Control field (e.g., an EHT OM Control subfield 2120). Another option may use an action frame 2130 (e.g., an EML Operating Mode Notification (OMN) frame). In an embodiment, action frame 2130 may comprise an EHT TPS Control element and EHT TPS Control element may comprise TXS power save mode 2 Enabling subfield 2125.

[0198] In one or more embodiments, signaling values that correspond to TXS power saving entry may be performed by utilizing a TXS power saving entry subfield. For example, a STA may indicate whether the STA transitions ( / enters) a second power state (e.g ., a doze state) or an unavailable state during the remaining duration (TXS allocation duration or TXOP). The TXS power saving entry subfield may be included in a QoS null / data frame (e.g., CAS control field or new A-Control field) or a control, management, action frame or in the SIG field (e.g., U-SIG, UHR-SIG, etc.) of a preamble of the PPDU carrying the field. In some implementations, when the TXS power saving entry subfield may be set to one (1), and this may indicate that the STA transitions ( / enters) a second power state (e.g., doze state) during the remaining duration in a power save mode. Additionally or alternatively, the TXS power saving entry subfield may be set to one (1 ) when the STA will be unavailable during the remaining duration (allocation or TXOP) in an active mode. In an embodiment, setting the TXS power saving entry subfield to one (1), may occur when one or more of the following conditions is met: if the STA transmitted a first frame comprising the TXS power saving entry subfield set to one (1 ), if the STA receives a second frame (e.g., immediate response frame (Ack or BA), response management frame, a control frame, a management frame, or an action frame). As used herein,

[0199] In some implementations, if the STA receives a second frame (e.g., an immediate response frame (Ack or BA) or response management frame) in response to the first frame comprising the TXS power saving entry subfield, then the second frame indicates that the STA is allowed to be in a second power state (e.g., a doze state in the TXS power save mode (e.g., TXS power save mode 2) during the remaining duration or that the STA is allowed to be unavailable in an active mode during the remaining duration. It should be noted that for one or more approaches to utilizing TXS power saving operations described herein, the STA and / or the AP supports TXS power save mode 2 and / or the STA acti vates / enables the TXS power save mode 2.

[0200] In one or more embodiments, a TXS power saving allowance subfield may be used by an AP to indicate whether a non-AP STA is allowed to enter a second power state (e.g., doze state) in a power save mode (e.g., TXS power save mode 2) during the remaining duration or whether the non-AP STA is allowed to be unavailable in an active mode during the remaining duration (allocation or TXOP). The TXS power saving allowance subfield field may be included in an immediate response frame (e.g., Ack frame or BlockAck (BA) frame), a control frame, a management frame, an action frame, or a QoS null / data frame, or in the SIG field (e.g., U-SIG, UHR-SIG, etc.) of preamble of the PPDU carrying the field. If the STA receives a frame carrying the TXS power saving allowance subfield set to one (1), the non-AP STA may transition (or enter) a second power state (e.g., doze state) in a power save mode (e.g., TXS power save mode 2) during the remaining duration or the non-AP STA may be unavailable in an active mode during a remaining duration (e.g., allocation duration or TXOP), when one or more of the following conditions is met: the STA transmitted a first frame comprising the TXS power saving entry subfield set to one (1) (e.g., before the STA receives the TXS power saving allowance subfield), the STA received a second frame (e.g., immediate response frame (Ack or BA) or a management frame, or a control frame, QoS null / data frame, or an action frame), the STA receives a second frame (e.g., immediate response frame (Ack or BA) or response management frame) in response to the first frame comprising the TXS power saving entry subfield, and the second frame indicates that the STA is allowed to be in a second power state (e.g., dozestate) in a power save mode (e.g., TXS power save mode 2) during the remaining duration or that the STA is allowed to be unavailable in an active mode during the remaining duration. The TXS power saving allowance subfield may be set to one (1) when one or more of the following conditions are met: when the AP does not have buffered traffic to be sent to the STA, when the AP has non-low latency traffic for the STA, and when the AP has non-low latency buffered traffic for the STA but the AP has low latency traffic for another STA.

[0201] In one or more embodiments, a Buffered Traffic Indication subfield may be used by an AP to indicate whether the AP has buffered traffic (or low latency traffic) to be sent to a STA. In some implementations, the Buffered Traffic Indication subfield field may be included in an immediate response frame (e.g., Ack frame or BlockAck (BA) frame), a control frame, a management frame, an action frame, a QoS null / data frame, and in the SIG field (e.g., U-SIG, UHR-SIG, etc.) of preamble of the PPDU carrying the field. In some implementations, the Buffered Traffic Indication subfield is set to one (1) to indicate that the AP has buffered traffic (or low latency buffered traffic) to be sent to the STA. Otherwise it is set to zero (0)

[0202] In some implementations, when the STA receives a frame carrying the subfield set to one (1), the non-AP STA may transition (or enter) a second power state (e.g., doze state) or an unavailable state during a remaining duration (e.g., allocation duration or TXOP), when one or more of the following conditions is met: the STA transmitted a first frame comprising the TXS power saving entry subfield set to one (1) (e.g., before the STA receives the Buffered Traffic Indication subfield), the STA received a second frame (e.g., immediate response frame (Ack or BA) or a management frame, or a control frame, QoS null / data frame, or an action frame), the STA receives a second frame (e.g., immediate response frame (Ack or BA) or response management frame) in response to the first frame comprising the TXS power saving entry subfield, when the second frame indicates that the STA is allowed to be in a second power state (e.g., doze state) in a power save mode (e.g., TXS power save mode 2) during the remaining duration or that the STA is allowed to be unavailable in an active mode during the remaining duration, when the STA and / or the AP supports TXS power save mode 2, and the STA activates / enables the TXS power save mode 2.

[0203] FIG. 22 illustrates an example process 2200 according to an embodiment. Example process 2200 may be performed by an AP, such as AP 1410, AP 1510, AP 1610, AP 1710, AP 1810, 1910, or AP 2010 described above. As shown in FIG. 22, process 2200 may include steps 2202 and 2204.

[0204] Step 2202 includes transmitting, by the access point (AP) to a station (STA), a first frame indicating a time period, of a transmit opportunity (TXOP), allocated to the STA. The STA may be associated with the AP. The first frame may comprise a trigger frame. The trigger frame may comprise an MRTT frame.

[0205] Step 2204 includes receiving, by the AP from the STA and during the time period, a second frame indicating a return by the STA of the time period to the AP. In an embodiment, the second frame comprises a QoS data frame, a QoS null frame, an action frame, a control frame, or a management frame.

[0206] In an embodiment, process 2200 may further comprise, receiving, by the AP from the STA and during the first time period, a third frame comprising a first indication of transitioning from the first power state to the second power state. In an embodiment, the second frame comprises the first indication. In an embodiment, the second frame or the thirdframe is a control frame, a management frame, an action frame, a QoS data frame ora QoS null frame. In an embodiment, process 2200 may further comprise, transmitting, by the AP to the STA and during the first time period, a fourth frame comprising a second indication whether the STA is allowed to be in the second power state. In an embodiment, the AP transmits, to the STA, the fourth frame in response to the second frame.

[0207] In an embodiment, the AP transmits, to the STA, the fourth frame in response to the second frame comprising the first indication. In an embodiment, the AP transmits, to the STA, the fourth frame in response to the third frame. In an embodiment, the fourth frame is a Trigger frame, an immediate response frame, a control frame, a management frame, an action frame, a QoS data frame or a QoS null frame. In an embodiment, the trigger frame comprises an MU-RTS TXS Trigger frame or an MU-RTS Trigger frame. In an embodiment, the immediate response frame comprises an acknowledgement (Ack) frame or a BlockAck (BA) frame. In an embodiment, the Ack frame or the BA frame comprises a more data (MD) subfield set to 0 to indicate that the STA is allowed to be in the second power state. In an embodiment, the Ack frame or the BA frame comprises a more data (MD) subfield set to 1 to indicate that the STA is not allowed to be in the second power state. In an embodiment, the second indication that the STA is allowed to be in the second power state comprises that the AP does not have buffered traffic for the STA.

[0208] In an embodiment, the second indication that the STA is allowed to be in the second power state comprises that the AP has a non-low latency buffered traffic for the STA and the AP has a low latency buffered traffic for another STA. In an embodiment, the second indication that the STA is allowed to be in the second power state comprises that the AP has buffered traffic for the STA, but the AP has more urgent traffic for other STA. In an embodiment, process 2200 may further comprise, transmitting, by the AP to the STA and during the first time period, the fourth frame comprising a third indication whether the AP has buffered traffic for the STA. In an embodiment, process 2200 may further comprise, transmitting, by the AP to the STA and during the first time period, the fourth frame comprising a third indication whether the AP has a low latency buffered traffic for the STA. In an embodiment, process 2200 may further comprise, receiving, by the AP from the STA and before the first time period, a fifth frame comprising a first capability whetherthe STA supports the TXS power saving operation, and after receiving the fifth frame, transmitting, by the AP to the STA, a sixth frame comprising a second capability whether the AP supports TXS power saving operation.

[0209] In an embodiment, the fifth frame is a probe request frame, an association request frame, a control frame, a management frame, an action frame, a QoS data frame or a QoS null frame. In an embodiment, the sixth frame is a probe response frame, an association response frame, a control frame, a management frame, an action frame, a QoS data frame or a QoS null frame. In an embodiment, a broadcast addressed frame further comprises the second capability. In an embodiment, the broadcast addressed frame is a beacon frame or a probe response frame, or a fast initial link setup (FILS) discovery frame.

[0210] FIG. 23 illustrates another example process 2300 according to an embodiment. Example process 2300 may be performed by a first STA, such as STA 1411, STA 1511, STA 1611, STA 1711, STA 1811, 1911, or 2011, described above. As shown in FIG. 23, process 2300 may include steps 2302, 2304, and 2306.

[0211] Step 2302 includes receiving, by a station (STA) from an access point (AP), a first frame indicating a time period, of a transmit opportunity (TXOP), allocated to the STA. The first STA may be associated with the AP. The first frame may comprise a trigger frame. The trigger frame may comprise an MRTT frame. Step 2304 includes transmitting, by the STA to the AP and during the time period, a second frame indicating a return by the STA of the time period to the AP. In an embodiment, the second frame comprises a QoS data frame, a QoS null frame, an action frame, a control frame, or a management frame. Step 2306 includes, after transmitting the second frame, transitioning, by the STA, from a first power state (awake) to a second power state (doze).

[0212] In an embodiment, the second frame comprises the first indication. In an embodiment, the second frame or the third frame is a control frame, a management frame, an action frame, a QoS data frame or a QoS null frame. In an embodiment, process 2300 may further comprise, receiving, by the STA from the AP and during the first time period, a fourth frame comprising a second indication whether the STA is allowed to be in the second power state, and based on the second indication that the STA is allowed to be in the second power state, transitioning, by the STA, from the first power state to the second power state.

[0213] In an embodiment, the STA receives, from the AP, the fourth frame in response to the second frame. In an embodiment, the STA receives, from the AP, the fourth frame in response to the second frame comprising the first indication. In an embodiment, the STA receives, from the AP, the fourth frame in response to the third frame. In an embodiment, the fourth frame is a Trigger frame, an immediate response frame, a control frame, a management frame, an action frame, a QoS data frame or a QoS null frame. In an embodiment, the trigger frame comprises an MU-RTS TXS Trigger frame. In an embodiment, the immediate response frame comprises an acknowledgement (Ack) frame or a BlockAck (BA) frame. In an embodiment, the Ack frame or the BA frame comprises a more data ( MD) subfield set to 0 to indicate that the STA is allowed to be in the second power state In an embodiment, the Ack frame or the BA frame comprises a more data (MD) subfield set to 1 to indicate that the STA is not allowed to be in the second power state. In an embodiment, the second indication that the STA is allowed to be in the second power state comprises that the AP does not have buffered traffic for the STA.

[0214] In an embodiment, the second indication that the STA is allowed to be in the second power state comprises that the AP has a non-low latency buffered traffic for the STA and the AP has a low latency buffered traffic for another STA. In an embodiment, the second indication that the STA is allowed to be in the second power state comprises that the AP has buffered traffic for the STA, but the AP has more urgent traffic for other STA. In an embodiment, process 2300 may further comprise, receiving, by the STA from the AP and during the first time period, the fourth frame comprising a third indication whether the AP has buffered traffic for the STA, and based on the third indication that the AP does not have buffered traffic for the STA, transitioning, by the STA, from the first power state to the second power state.

[0215] In an embodiment, process 2300 may further comprise, receiving, by the STA from the AP and during the first time period, the fourth frame comprising a third indication whether the AP has a low latency buffered traffic for the STA, and based on the third indication that the AP does not have the low latency buffered traffic for the STA, transitioning, by the STA, from the first power state to the second power state. In an embodiment, process 2300 may further comprise,transmitting, by the STA to the AP and before the first time period, a fifth frame comprising a first capability whether the STA supports the TXS power saving operation, after transmitting the fifth frame, receiving, by the STA from the AP, a sixth frame comprising a second capability whether the AP supports TXS power saving operation, and based on the first capability and the second capability supporting the TXS power saving operation, transitioning, by the STA, from the first power state to the second power state.

[0216] In an embodiment, the fifth frame is a probe request frame, an association request frame, a control frame, a management frame, an action frame, a QoS data frame or a QoS null frame. In an embodiment, the sixth frame is a probe response frame, an association response frame, a control frame, a management frame, an action frame, a QoS data frame or a QoS null frame. In an embodiment, a broadcast addressed frame further comprises the second capability. In an embodiment, the broadcast addressed frame is a beacon frame or a probe response frame, or a fast initial link setup (FILS) discovery frame.

[0217] In an implementation, a second power state may be referred to as a lower power receive state or a listen / listening state. While in the second power state, the STA is capable of receiving PPDUs of a first category. In an implementation, the STA is capable of receiving PPDUs of only the first category during the second power state.

[0218] In an implementation, the first category may include PPDUs having a non-HT PPDU format. In another implementation, the first category may include, additionally or alternatively, PPDUs having a data rate that is less than or equal to 24 Mbps, a bandwidth of 20 MHz, and / or a single spatial stream.

[0219] FIG. 24 illustrates an example 2400 of one or more embodiments that may utilize a power saving operation during a TXS procedure. As shown in FIG. 24, example 2400 includes AP 2410 and STAs 2411 and 2412 associated with AP 2410.

[0220] Example 2400 may begin with AP 2410 transmitting an MRTT frame 2415 to specify allocation duration 2465 of obtained TXOP 2455 to be allocated to STA 2411. In this example, MRTT frame 2415 specifies a TXOP sharing mode of 2 (e.g., for communication between STAs 2411 and 2412), a value corresponding to allocation duration 2465, and potentially, as discussed below, MRTT frame 2415 may include information corresponding to indication 2417 (TXS PS is allowed to be used). The indication 2417 may indicate whether TXS PS is allowed to be used by the STA 2411. The indication 2417 may indicate whether the AP has the buffered traffic for the STA 2411. The indication 2417 may indicate whether the AP has low latency / latency sensitive / urgent buffered traffic for the STA 2411. The indication 2417 may indicate whether the AP will schedule the DL transmission for the STA 2411 faster than other STAs during TXOP 2455 orallocation duration 2465. For example, the indication 2417 may indicate that the AP will schedule the DL transmission for the STA 2411 faster than other STAs during TXOP 2455 or allocation duration 2465 when the AP has low latency / latency sensitive / urgent buffered traffic for the STA 2411. In that case, AP will transmit DL PPDU for the STA 2411 faster than other STAs during TXOP 2455 or allocation duration 2465 and STA 2411 will be in awake state after transmitting QoS null frame 2470 and then receiving an immediate response frame (e.g., acknowledgement frame 2435) in response to QoS null frame 2470. For example, the indication 2417 may indicate that the AP will not schedule the DL transmission for the STA 2411 faster than other STAs during TXOP 2455 or allocation duration 2465 when the AP doesnot have low latency / latency sensitive / urgent buffered traffic for the STA 2411. If the indication 2417 indicates that the will not schedule the DL transmission for the STA 2411 faster than other STAs during TXOP 2455 or allocation duration 2465, AP may transmit DL PPDU for other STAs faster than STA 2411 during TXOP 2455 or allocation duration 2465 and STA 2411 will transition to the second power state (Listen State) after transmitting QoS null frame 2470 and then receiving an immediate response frame (e.g., acknowledgement frame 2435) in response to QoS null frame 2470.

[0221] On receiving MRTT frame 2415, STA 2411 may transmit CTS frame 2440 to AP 2410. In accordance with allocation duration 2465, STA 2411 may subsequently transmit non-TB PPDUs 2460-1 and 2460-2 to STA 2412, with STA 2412 transmitting one or more BA frames 2420-1 and 2420-2 to STA 2411, in response to non-TB PPDUs 2460-1 and 2460-2, respectively. In one or more embodiments, to indicate to AP 2410 that no additional data is to be communicated by STA 2411 to STA 2412, QoS null frame 2470 may be communicated to AP 2410 by STA 2411.

[0222] As discussed above with FIG. 24, in one or more embodiments, AP 2410 may analyze different factors associated with whether STA 2411 should be permitted to enter listen state 2430. Example factors that may be evaluated as favoring permitting STA 2411 to enter listen state 2430 include, but are not limited to, that AP 2410 does not have buffered traffic for STA 2411 , that AP 2410 has non-low latency buffered traffic for STA 2411 , and that AP 2410 has low- latency buffered traffic for another STA associated with AP 2410, and / or that AP 2410 has buffered traffic for STA 2411 , but AP 2410 has more urgent traffic than the buffered traffic for another STA associated with AP 2410.

[0223] In additional or alternative embodiments, at the time that QoS null frame 2470 is utilized by STA 2411 to indicate to AP 2410 that no additional data is to be communicated by STA 2411 to STA 2412, STA 2411 can utilize an indication 2471 to request to be allowed to utilize TXS power saving operation. At that time, based at least on the example factors described above, AP 2410 can determine whether to permit usage of TXS power saving operation by STA 2411 in response to indication 2471 (TXS PS request) included with QoS null frame 2470.

[0224] With respect to communicating determination information corresponding to indication 2417 to STA 2411, one or more embodiments can utilize approaches described with FIG. 15 above, e.g., an approach to communicating the determination may utilize a frame communicated from AP 2410 to STA 1511, including one or more of a trigger frame, an immediate response frame (e.g., an Ack frame or BlockAck (BA) frame), a control frame, a management frame, an action frame, a QoS data frame, and / or a QoS null frame. Examples that use an immediate response frame (e.g., acknowledgement frame 2435) are described with FIGS. 15 and 20. The immediate response frame (e.g., acknowledgement frame 2435) may comprise indication 2417. In an embodiment, indication 2417 may be comprised in a separate frame with acknowledgement frame 2435. In an additional or alternative embodiment, indication 2471 may be comprised in a separate frame with QoS null frame 2470. In an embodiment, AP 2410 and STA 2411 operations for indication 2417 will be same as the operations described above.

[0225] In an example, while STA 2411 is in listen state 2430, AP 2410 may transmit DL PPDU 2436 to STA 2412 and STA 2412 may transmit BA 2420-3 to AP 2410 in response to DL PPDU 2436. In an example, AP 2410 may transmit an initial control frame (IGF) 2437 to STA 2411. The initial control frame may comprise a RTS frame, an MU-RTS frame, a BSRP frame, a BAR frame, or a new control frame. After receiving ICF 2437, STA 2411 may transition from the secondpower state (listen state) to the first power state (awake state). In response to ICF 2437, STA 2411 may transmit an initial control response frame (ICR) 2480 to AP 2410. After receiving ICR 2480, AP 2410 may transmit DL PPDU 2436 to STA 2411. In response to DL PPDU 2436, STA 2411 may transmit BA 2485

Claims

CLAIMSWhat is claimed is:

1. A method comprising: receiving, by a station (STA) from an access point (AP), a first frame indicating: a first time period, of a transmit opportunity (TXOP) , allocated to the STA; and a sharing mode of the first time period; transmitting, by the STA to the AP and during the first time period, a second frame indicating a return by theSTA of the first time period to the AP; and after transmitting the second frame, transitioning, by the STA, from a first power state to a second power state based on the sharing mode.

2. A method comprising: receiving, by a station (STA) from an access point (AP), a first frame indicating a first time period, of a transmit opportunity (TXOP), allocated to the STA; transmitting, by the STA to the AP and during the first time period, a second frame indicating a return by the STA of the first time period to the AP; and after transmitting the second frame, transitioning, by the STA, from a first power state to a second power state.

3. The method of claim 2, wherein the first frame further indicates a sharing mode of the first time period.

4. The method of claim 3, wherein the transitioning, by the STA, from the first power state to the second power state is based on the sharing mode.

5. The method of any of claims 2-4, further comprising: transmitting, by the STA to the AP and during the first time period, a third frame comprising a first indication of transitioning from the first power state to the second power state; and after transmitting the third frame, transitioning, by the STA, from the first power state to the second power state.

6. The method of claim 5, wherein the second frame comprises the first indication.

7. The method of any of claims 5-6, wherein the second frame or the third frame is a control frame, a management frame, an action frame, a quality of service (QoS) data frame or a QoS null frame.

8. The method of any of claims 5-7, further comprising: receiving, by the STA from the AP and during the first time period, a fourth frame comprising a second indication whether the STA is allowed to be in the second power state; and based on the second indication that the STA is allowed to be in the second power state, transitioning, by the STA, from the first power state to the second power state.

9. The method of claim 8, wherein the STA receives, from the AP, the fourth frame in response to the second frame.

10. The method of any of claims 8-9, wherein the STA receives, from the AP, the fourth frame in response to the second frame comprising the first indication.

11. The method of claim 8, wherein the STA receives, from the AP, the fourth frame in response to the third frame.

12. The method of any of claims 8-11, wherein the fourth frame is a Trigger frame, an immediate response frame, a control frame, a management frame, an action frame, a QoS data frame or a QoS null frame.

13. The method of claim 12, wherein the Trigger frame comprises a multi-user request to send (MU-RTS) transmission opportunity sharing (TXS) trigger (MRTT) frame.

14. The method of claim 12, wherein the immediate response frame comprises an acknowledgement (Ack) frame or a blockack (BA) frame.

15. The method of claim 14, wherein the Ack frame or the BA frame comprises a more data (MD) subfield set to 0 to indicate that the STA is allowed to be in the second power state.

16. The method of claim 14, wherein the Ack frame or the BA frame comprises an MD subfield set to 1 to indicate that the STA is not allowed to be in the second power state.

17. The method of any of claims 8-16, wherein the second indication that the STA is allowed to be in the second power state comprises that the AP does not have buffered traffic for the STA.

18. The method of any of claims 8-16, wherein the second indication that the STA is allowed to be in the second power state comprises that the AP has a non-low latency buffered traffic for the STA and the AP has a low latency buffered traffic for another STA.

19. The method of any of claims 8-16, wherein the second indication that the STA is allowed to be in the second power state comprises that the AP has buffered traffic for the STA, but the AP has more urgent traffic for other STA.

20. The method of any of claims 8-19, further comprising: receiving, by the STA from the AP and during the first time period, the fourth frame comprising a third indication whether the AP has buffered traffic for the STA; and based on the third indication that the AP does not have buffered traffic for the STA, transitioning, by the STA, from the first power state to the second power state.

21. The method of claim 20, further comprising: receiving, by the STA from the AP and during the first time period, the fourth frame comprising a third indication whether the AP has a low latency buffered traffic for the STA; and based on the third indication that the AP does not have the low latency buffered traffic for the STA, transitioning, by the STA, from the first power state to the second power state.

22. The method of any of claims 2-21, further comprising: transmitting, by the STA to the AP and before the first time period, a fifth frame comprising a first capability whether the STA supports a TXS power save (PS) operation; after transmitting the fifth frame, receiving, by the STA from the AP, a sixth frame comprising a second capability whether the AP supports TXS PS operation; and based on the first capability and the second capability supporting the TXS PS operation, transitioning, by the STA, from the first power state to the second power state.

23. The method of claim 22, wherein the fifth frame is a probe request frame, an association request frame, a control frame, a management frame, an action frame, a QoS data frame or a QoS null frame.

24. The method of any of claims 22-23, wherein the sixth frame is a probe response frame, an association response frame, a control frame, a management frame, an action frame, a QoS data frame or a QoS null frame.

25. The method of any of claims 22-24, wherein a broadcast addressed frame further comprises the second capability.

26. The method of claim 25, wherein the broadcast addressed frame is a beacon frame or a probe response frame, or a fast initial link setup (FILS) discovery frame.

27. The method of any of claims 2-26, further comprising: transmitting, by the STA to the AP and before the first time period, a seventh frame comprising an indication of an activation or a deactivation of TXS PS mode; receiving, by the STA from the AP, an eighth frame in response to the seventh frame; and based on the indication of the activation of TXS PS mode, transitioning, by the STA, from the first power state to the second power state.

28. The method of claim 27, wherein the eighth frame comprises an indication of acceptance or rejection of the activation of the TXS PS mode.

29. The method of any of claims 27-28, wherein the seventh frame is a control frame, a management frame, an action frame, a QoS data frame ora QoS null frame.

30. The method of any of claims 27-29, wherein the eighth frame is an immediate response frame, a control frame, a management frame, an action frame, a QoS data frame ora QoS null frame.

31. The method of any of claims 2-30, wherein the first power state corresponds to an awake state for the STA in a power save mode or an active mode.

32. The method of any of claims 2-31 , wherein the second power state corresponds to a doze state for the STA being in a power save mode.

33. The method of claim any of claims 2-32, wherein the second power state corresponds to the STA being unavailable while being in an awake mode.

34. The method of any of claims 2-33, wherein the second frame comprises a high efficiency (HE) variant high throughput (HT) control field with a command and status (CAS) control subfield with a reverse direction grant (RDG)Zmore physical layer (PHY) protocol data unit (PPDU) subfield equal to 0.

35. The method of any of claims 3-34, wherein the sharing mode is set to TXS mode 2.

36. The method of any of claims 2-35, wherein after transitioning to the second power state, the STA maintains the second power state for a first remaining duration of the first time period.

37. The method of any of claims 2-35, wherein after transitioning to the second power state, the STA maintains the second power state for a second remaining duration of the TXOP.

38. The method of any of claims 2-37, further comprising transitioning by the STA from the second power state to the first power state after an end of the first time period.

39. The method of claim 2-37, further comprising transitioning by the STA from the second power state to the first power state after an end of the TXOP.

40. A method comprising: transmitting, by an access point (AP) to a station (STA), a first frame indicating: a first time period of a transmit opportunity (TXOP), allocated to the STA; and a sharing mode of the first time period; receiving, by the AP from the STA during the first time period, a second frame indicating a return by the STA of the first time period to the AP; and receiving, by the AP from the STA and during the first time period, a third frame comprising a first indication of transitioning from a first power state to a second power state.

41. A method comprising: transmitting, by an access point (AP) to a station (STA), a first frame indicating: a first time period of a transmit opportunity (TXOP), allocated to the STA; and a sharing mode of the first time period; and receiving, by the AP from the STA during the first time period, a second frame indicating a return by the STA of the first time period to the AP.

42. The method of claim 41 , further comprising receiving, by the AP from the STA and during the first time period, a third frame comprising a first indication of transitioning from a first power state to a second power state.

43. The method of claim 42, further comprising transmitting, by the AP to the STA and during the first time period, a fourth frame comprising a second indication whether the STA is allowed to be in the second power state.

44. The method of claim 43, wherein the AP transmits, to the STA, the fourth frame in response to the third frame.

45. The method of any of claims 41-44, further comprising: receiving, by the AP from the STA and before the first time period, a fifth frame comprising a first capability whether the STA supports a TXS PS operation; and after receiving the fifth frame, transmitting, by the AP to the STA, a sixth frame comprising a second capability whether the AP supports the TXS PS operation.

46. The method of any of claims 41-45, further comprising: receiving, by the AP from the STA and before the first time period, a seventh frame comprising an indication of an activation or a deactivation of a TXS PS mode; and transmitting, by the AP to the STA, an eighth frame in response to the seventh frame.

47. A device comprising: one or more processors; andmemory storing instructions that, when executed by the one or more processors, cause the device to perform a method according to any of claims 1-46.

48. 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 1-46.

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