Patent Description:
The present disclosure is generally related to wireless communications and, more particularly, to efficient trigger-based (TB) multi-user (MU) uplink (UL) transmissions in wireless local area networks (WLANs).

Document <CIT> discloses methods according to the preamble parts of the independent claims.

For TB MU UL transmissions, a triggered station (STA) can only transmit using an exact resource unit (RU) or an aggregate of multiple RUs (multi-RU or MRU) assigned in a trigger frame. In next-generation wireless communications such as those implemented in WLANs based on the Institute of Electrical and Electronics Engineers (IEEE) <NUM>. 11ac/ax standards, an access point (AP) that sends the trigger frame does not know the clear channel assessment (CCA) status of the target triggered STAs. Thus, a STA that is allocated a RU/MRU in the trigger frame cannot transmit any signal if the CCA of one or more <NUM> subchannels within its allocated
RU/MRU is not clear. For example, when a STA is triggered for UL orthogonal frequency-division multiple access (OFDMA) transmission with an assigned <NUM>-tone RU (RU996), the STA would not participate in the UL OFDMA transmission in case CCA indicates a second <NUM> subchannel is busy. That is, in IEEE <NUM>. 11ax, when the AP configures channel sensing (CS) required (e.g., by setting "CS Required = <NUM>"), then the triggered STA is required to perform CCA per-<NUM> subchannel before responding to the trigger frame. If any portion of the allocated frequency resource is detected to be busy during the CCA, then the STA would not transmit any TB physical-layer protocol data unit (PPDU). As can been, spectrum usage efficiency would be degraded under this protocol. Therefore, there is a need for a solution for efficient TB MU UL transmissions in WLANs.

The following summary is illustrative only and is not intended to be limiting in any way. That is, the following summary is provided to introduce concepts, highlights, benefits and advantages of the novel and non-obvious techniques described herein. Select implementations are further described below in the detailed description. Thus, the following summary is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining the scope of the claimed subject matter.

An objective of the present disclosure is to provide schemes, concepts, designs, techniques, methods and apparatuses pertaining to efficient TB MU UL transmissions in WLANs. Under various proposed schemes in accordance with the present disclosure, it is believed that issue(s) described herein may be addressed. For instance, if a STA can transmit a <NUM>-tne RU or a <NUM>-tone RU or an aggregate of the <NUM>-tone RU and the <NUM>-tone RU (MRU(<NUM>+<NUM>)) out of a <NUM>-tone RU when one of the <NUM> subcarriers is busy, then spectrum efficiency could be enhanced. Methods and apparatus according to the invention are defined in the independent claims. The dependent claims define preferred embodiments thereof.

It is noteworthy that, although description provided herein may be in the context of certain radio access technologies, networks and network topologies such as, Wi-Fi, the proposed concepts, schemes and any variation(s)/derivative(s) thereof may be implemented in, for and by other types of radio access technologies, networks and network topologies such as, for example and without limitation, Bluetooth, ZigBee, 5th Generation (<NUM>)/New Radio (NR), Long-Term Evolution (LTE), LTE-Advanced, LTE-Advanced Pro, Internet-of-Things (IoT), Industrial loT (IIoT) and narrowband loT (NB-loT).

Only the embodiments shown in <FIG> are claimed.

Implementations in accordance with the present disclosure relate to various techniques, methods, schemes and/or solutions pertaining to efficient TB MU UL transmissions in WLANs. According to the present disclosure, a number of possible solutions may be implemented separately or jointly. That is, although these possible solutions may be described below separately, two or more of these possible solutions may be implemented in one combination or another.

It is noteworthy that, although examples described herein and illustrated in the figures may show a first RU of size A and a second RU of size B, as in RU A + RU B, various proposed schemes in accordance with the present disclosure may be implemented with RU A + RU B, or vice versa (e.g., RU B + RU A). In other words, the scope of the present disclosure is not limited to the examples presented herein and, rather, also covers variations thereof. For instance, for a multi-RU group (<NUM> + <NUM>), the order of RUs may be exchanged in different implementations such as, for example, a first RU of size <NUM> plus a second RU of size <NUM> in one implementation or, alternatively, a firs RU of size <NUM> plus a second RU of size <NUM> in another implementation. Moreover, in the present disclosure, aggregated multiple RUs may be interchangeably referred to as "multi-RU" and "MRU". Thus, in the aforementioned example, the multi-RU group (<NUM> + <NUM>), which is an aggregation of two RUs (namely a <NUM>-tone RU and a <NUM>-tone RU), may be referred to as a multi-RU(<NUM> + <NUM>) or an MRU(<NUM> + <NUM>).

Referring to <FIG>, network environment <NUM> may involve a communication entity <NUM> and a communication entity <NUM> communicating wirelessly (e.g., in a WLAN in accordance with one or more IEEE <NUM> standards). For instance, communication entity <NUM> may be a first STA and communication entity <NUM> may be a second STA, with each of the first STA and second STA being an access point (AP) STA or a non-AP STA. Under various proposed schemes in accordance with the present disclosure, communication entity <NUM> and communication entity <NUM> may be configured to perform efficient TB MU UL transmissions in WLANs, as described herein.

Under a proposed scheme in accordance with the present disclosure with respect to enhanced TB UL transmissions, an AP (e.g., communication entity <NUM>) may be aware of the CCA status of its target STA(s) and may allocate a RU/MRU for each of the target STA(s) without violating the CCA status of the target STA(s). Currently, in a multi-user request-to-send (MU-RTS) and clear-to-send (CTS) procedure, the AP cannot tell from the CTS which STA(s) has responded to the MU-RTS with CTS. Thus, whether or not a STA responds with CTS, the AP would continue the transmission anyway. Accordingly, under the proposed scheme, a medium access control (MAC)-layer scheme which is also a CCA status report scheme may be required to avoid no transmission due to subchannel CCA busy. Moreover, under the proposed scheme, a physical (PHY)-layer scheme involving UL subcarrier puncturing or downsized RU/MRU by a STA may be required. For instance, under the PHY-layer scheme, the STA (e.g., communication entity <NUM>) may reduce the size of its allocated RU/MRU for UL TB transmissions. The STA may also signal to the AP about its downsized RU/MRU in TB PPDU. Moreover, the STA may control its transmit power correspondingly.

<FIG> illustrates an example scenario <NUM> of an implementation of a proposed scheme regarding CCA status report and period protection setup. Under the proposed scheme, a CCA status report mechanism is needed in order to avoid allocation of a RU/MRU that contains busy CCA subchannel(s) to a STA for TB MU UL transmissions. Current multi-RTS/CTS only sets up a protection period for UL TB transmissions. As for status reporting, a bandwidth query report (BQR) and/or buffer status report (BSR) as well as a bandwidth query report poll (BQRP) and/or buffer status report poll (BSRP) may be used to report CCA status. Referring to <FIG>, initially an AP may transmit a MU-RTS and, correspondingly, a first STA and a second STA (STA1 and STA2) may each respond with a CTS. Then, the AP may transmit a BQRP/BSRP to STA1 and, in response, STA1 may transmit a BQR/BSR to the AP. Similarly, the AP may transmit a BQRP/BSRP to STA2 and, in response, STA2 may transmit a BQR/BSR to the AP. Under the proposed scheme, the BQR/BSR from each of STA1 and STA2 may include a respective CCA status report so that AP may become aware of the CCA status with respect to each of STA1 and STA2.

Under the proposed scheme, BQR/BSR and BQRP/BSRP frames may be modified and may be referred to status reporting (SR) and status reporting poll (SRP), respectively. The SR may be used to report CCA status of <NUM> subchannels in addition to the subfields contained in regular BQR and BSR. Under the proposed scheme, in case that CCA status is not a subfield in the SR frame, the SR frame itself may serve as a CCA indicator by sending punctured SR frame. The SR frame may also set up a transmission opportunity (TXOP) period for upcoming TB MU UL transmissions.

<FIG> illustrates an example scenario <NUM> of an implementation of a proposed scheme regarding enhanced trigger procedure for UL TB transmissions. Under the proposed scheme, TB MU UL transmissions may follow a status report stage. For instance, in a trigger frame transmitted by the AP, the AP may allocate RU/MRU(s) to a STA according to the CCA status report from that STA. Referring to <FIG>, initially an AP may transmit a MU-RTS and, correspondingly, STA1 and STA2 may each respond with a CTS. Then, the AP may transmit a BQRP/BSRP to STA1 and, in response, STA1 may transmit a BQR/BSR to the AP. Similarly, the AP may transmit a BQRP/BSRP to STA2 and, in response, STA2 may transmit a BQR/BSR to the AP. Subsequently, the AP may transmit a trigger frame to trigger STA1 and STA2 to perform TB MU UL transmissions. The trigger frame may allocate one or more RU/MRUs to each of STA1 and STA2. Accordingly, each of STA1 and STA2 may respectively transmit one or ore UL TB PPDUs using its allocated RU/MRUs.

<FIG> illustrates an example scenario <NUM> of an implementation of a proposed scheme regarding enhanced trigger procedure for UL TB transmissions. Referring to <FIG>, with knowledge of the CCA status of STAs, the AP may allocate in the trigger frame (<NUM>+<NUM>)-tone MRU to STA2 instead of allocating a <NUM>-tone RU to STA2 when one of the four <NUM> subchannels is detected to be busy during CCA. Additionally, the AP may allocate another <NUM>-tone RU to STA1 since no subchannel is busy for STA1. Accordingly, STA1 may perform UL TB transmissions using the allocated <NUM>-tone RU, while STA2 may perform UL TB transmissions using the allocated (<NUM>+<NUM>)-tone MRU.

Under a proposed scheme with respect to STA partial bandwidth or RU/MRU downsizing in accordance with the present disclosure, one or more predefined possible downsized RU/MRUs of each RU/MRU may be known to the AP and STAs. Under the proposed scheme, downsizing granularity may be <NUM> which corresponds to <NUM> subchannels and per-<NUM> CCA. For example, for a <NUM>-tone RU, the predefined downsized RU/MRUs may be a subset of a <NUM>-tone RU, a <NUM>-tone RU and a (<NUM>+<NUM>)-tone MRU. As another example, for a <NUM> x <NUM>-tone RU, the predefined downsized RU/MRUs may be a subset of a <NUM>-tone RU, a (<NUM>+<NUM>)-tone MRU and a (<NUM>+<NUM>)+<NUM>-tone MRU. For instance, when an AP triggers a STA with an allocated <NUM>+3x996-tone MRU, the predefined downsized RU/MRUs may be a subset of a 3x996-tone RU and a 2x996-tone RU.

Under another proposed scheme, efficient TB MU UL transmissions may still be achieved without explicit signaling to indicate RU/MRU downsizing. Under the proposed scheme, an AP may send a trigger frame to trigger an extremely-high-throughput (EHT) TB PPDU. The AP may indicate whether RU/MRU downsizing is allowed or whether UL subchannel puncturing is allowed in a User Information field of the trigger frame. For instance, one bit may be used to indicate whether or not RU/MRU downsizing is enabled (e.g., "<NUM>" = enabled and "<NUM>" = disabled). The AP may also include in the trigger frame a targeted received signal strength indicator (RSSI) as power control information for the RU/MRU assigned to STA(s). Correspondingly, a STA may transmit on a downsized RU/MRU based on <NUM> or <NUM> puncture. The EHT TB PPDU with downsized RU/MRU may utilize the same format as EHT TB PPDU without downsized RU/MRU. <FIG> illustrates an example design <NUM> of an EHT TB PPDU format. Referring to <FIG>, the EHT TB PPDU format may be used for auto-detection or EHT PPDU with or without RU/MRU downsizing. The EHT TB PPDU with downsized RU/MRU may have one more <NUM> channel punctured. There may be no explicit RU/MRU downsizing signaling carried in a preamble of the EHT TB PPDU. The AP may detect the downsized RU/MRU automatically for each STA using various auto-detection schemes described below.

Under a proposed scheme with respect to auto-detection of downsized RU/MRU, an AP may detect downsized RU/MRU using the legacy signal (L-SIG) field, repeated legacy signal (RL-SIG) field and/or universal signal (U-SIG) field in a preamble. Under the proposed scheme, the AP may decode L-SIG and/or U-SIG on every <NUM> to check a repetition pattern, contents, and the cyclic redundancy check (CRC) of each L-SIG and/or U-SIG. In case the repetition pattern, contents and/or CRC of L-SIG, RL-SIG and/or U-SIG is in error, the AP may assume the corresponding <NUM> subchannel is punctured. <FIG> illustrates an example scenario <NUM> of an implementation of the proposed scheme. In scenario <NUM>, the AP may trigger two STAs (e.g., STA1 and STA2) for UL OFDMA transmissions. Here, STA1 may be assigned with a first <NUM> (e.g., the first <NUM>-tone RU) and STA2 may be assigned with a second <NUM> (e.g., the second <NUM>-tone RU). STA1 may transmit an EHT TB PPDU on a downsized (<NUM>+<NUM>)-tone MRU. The AP may process the preamble of each <NUM> and check the content and CRC of the L-SIG, RL-SIG and/or U-SIGs to determine which <NUM> subchannel is punctured and then determine the downsized RU/MRU based on predefined downsized RU/MRU options. In the example shown in <FIG>, the AP may discover that the L-SIG, RL-SIG and/or U-SIG error in the second <NUM> subchannel for STA1, which may be punctured.

Under another proposed scheme with respect to auto-detection of downsized RU/MRU, an AP may compare the RSSI to a targeted RSSI of each <NUM> subchannel with a threshold in determining which subchannel is punctured. Using scenario <NUM> as an example, the AP may trigger two STAs (e.g., STA1 and STA2) for UL OFDMA transmissions. Here, STA1 may be assigned with a first <NUM> (e.g., the first <NUM>-tone RU) and STA2 may be assigned with a second <NUM> (e.g., the second <NUM>-tone RU). STA1 may transmit an EHT TB PPDU on a downsized (<NUM>+<NUM>)-tone MRU. The AP may compare the RSSI to the targeted RSSI of each <NUM> subchannel and determine that the second <NUM> subchannel has no signal, thereby deducing that the second <NUM> subchannel for STA1 may be punctured.

Under yet another proposed scheme with respect to auto-detection of downsized RU/MRU, an AP may detect downsized RU/MRU using the EHT short training field (EHT-STF) and/or EHT long training fields (EHT-LTFs) in a preamble. Under the proposed scheme, in case that a STA downsized its RU/MRU, the subcarriers in the EHT-STF and/or EHT-LTFs corresponding to the punctured <NUM> subchannel(s) may not be present. The AP may compare the received power on subcarriers in each <NUM> subchannel to a targeted RSSI to identify the punctured <NUM> subchannel(s). For UL multi-user multiple-input-and-multiple-output (MU-MIMO), the AP may compare the received power of the spatial streams assigned to each STA on subcarriers in each <NUM> subchannel to identify the punctured <NUM> subchannel(s) for the STA.

It is noteworthy that some or all of the above-described auto-detection schemes may be utilized together to enhance performance in auto-detection. Additionally, a transmission (TX) capability element for support of downsized RU/MRU may be defined for non-AP STAs. Moreover, the AP may transmit a trigger frame that contains an indication that RU/MRU downsizing is allowed/enabled or not for each assigned RU/MRU.

Under a proposed scheme with respect to STA explicit signaling of downsized RU/MRU, to avoid complexity in preamble processing for the AP, a STA may explicitly signal its downsized RU/MRU in a TB PPDU. For instance, a new format of EHT TB PPDU with a TB signal (TB-SIG) field may be introduced for this purpose. <FIG> illustrates an example design <NUM> under the proposed scheme. Referring to <FIG>, in the TB-SIG field, each STA may be allocated with a set of subcarriers to carry its downsized RU/MRU information. The set of subcarriers in TB-SIG allocated for each STA may also be indicated in the trigger frame. For 4x numerology, each STA may be assigned with a <NUM>-tone RU in the TB-SIG to carry its downsized RU/MRU information. For 1x numerology, each STA may be allocated N data tones, with N being <NUM> or <NUM> for example.

In an event that the TB-SIG symbol is 1x numerology, it may contain <NUM> or <NUM> data tones. In such cases, each STA may be allocated N data tones, with N being <NUM>, <NUM>, <NUM>, <NUM> and so on. Under the proposed scheme, a STA may transmit TB-SIG using only tones allocated to itself and may use zero energy on data tones not allocated to it. The allocated tones in TB-SIG may be a set of contiguous tones or a set of discrete interlaced (e.g., non-contiguous) tones. The bits carried on the allocated set of tones may contain the downsized RU/MRU information for that STA.

It is noteworthy that a BQR/BSR frame or a BQRP/BSRP frame may only poll STAs one by one. As such, when there are many STAs to be polled, the efficiency in polling the STAs for the CCA status of each STA may be very low. In view of this issue, two schemes are proposed herein to address this issue.

Under a proposed scheme to enhance the efficiency of status polling, triggered OFDMA PPDU may be utilized for status report. Under the proposed scheme, a trigger frame from an AP may trigger a status report frame from each STA using UL TB PPDU with an OFDMA format on the primary <NUM> subchannel among a plurality of subchannels. For instance, the trigger frame may trigger an UL TB OFDMA transmission from a plurality of STAs by assigning each STA a respective <NUM>-tone RU or <NUM>-tone RU within the primary <NUM>. Each triggered STA may use its assigned <NUM>-tone RU or <NUM>-tone RU to transmit its status report which indicates status of a respective plurality of subchannels according to CCA performed by that STA.

<FIG> illustrates an example scenario <NUM> of an implementation of the proposed scheme. Referring to <FIG>, an AP transmits an MU-RTS to a plurality of STAs including STA1, STA2 and STA3 over a wide bandwidth (e.g., <NUM> or greater). In response to receiving the MU-RTS, each of STA1, STA2 and STA3 transmits to the AP a respective CTS. Then, the AP transmits a trigger to the plurality of STAs, with the trigger assigning a respective RU/MRU to each STA. In response to receiving the trigger, each of STA1, STA2 and STA3 transmits to the AP a respective status report on its assigned RU/MRU within the primary <NUM> subchannel. Then, the AP transmits a trigger frame over the wide bandwidth which results in each of STA1, STA2 and STA3 transmitting one or more respective UL TB PPDUs over the wide bandwidth.

Under another proposed scheme to enhance the efficiency of status polling, a new type of trigger (or polling) frame may be utilized to trigger OFDMA duplicated (OFDMA DUP) PPDU. This new type of trigger (or polling) frame may trigger a status report frame using TB PPDU with OFDMA Duplicated format on a wide bandwidth (e.g., <NUM> or greater). The new type of trigger frame may trigger an UL TB OFDMA transmission to a plurality of STAs by assigning each STA a <NUM>-tone RU or <NUM>-tone RU within a primary <NUM> bandwidth. Each triggered STA may respond with a status report, including CCA status, using the assigned <NUM>-tone RU or <NUM>-tone RU within the primary <NUM>. Each triggered STA may duplicate the waveform of the primary <NUM> over the entire bandwidth without puncturing <NUM> subchannel(s) in an event that CCA of one or more <NUM> subchannels is not clear. Under the proposed scheme, MU-RTS/CTS may be unnecessary because the OFDMA DUP status report frame may set up the protection period for UL TB transmissions.

<FIG> illustrates an example scenario <NUM> of an implementation of the proposed scheme. Referring to <FIG>, an AP transmits a new trigger to a plurality of STAs including STA1, STA2 and STA3 over a wide bandwidth (e.g., <NUM> or greater). In response to receiving the trigger, each of STA1, STA2 and STA3 transmits to the AP a respective status report on its assigned RU/MRU. A protection period for UL TB transmissions by the STAs is set up by the OFDMA DUP status report frame. Then, the AP transmits a trigger frame over the wide bandwidth which results in each of STA1, STA2 and STA3 transmitting one or more respective UL TB PPDUs over the wide bandwidth.

<FIG> illustrates an example scenario <NUM> of an implementation of the proposed scheme. Referring to <FIG>, an OFDMA DUP PPDU may be an OFDMA PPDU duplicating the primary <NUM> subchannel over each <NUM> subchannel of the wide bandwidth. Each <NUM> may be used by multiple users (or STAs) using OFDMA format. For instance, each user may be assigned the same <NUM>-tone RU in each <NUM>.

<FIG> illustrates an example system <NUM> having at least an example apparatus <NUM> and an example apparatus <NUM> in accordance with an implementation of the present disclosure. Each of apparatus <NUM> and apparatus <NUM> may perform various functions to implement schemes, techniques, processes and methods described herein pertaining to efficient TB MU UL transmissions in WLANs, including the various schemes described above with respect to various proposed designs, concepts, schemes, systems and methods described above as well as processes described below. For instance, apparatus <NUM> may be an example implementation of communication entity <NUM>, and apparatus <NUM> may be an example implementation of communication entity <NUM>.

Each of apparatus <NUM> and apparatus <NUM> may be a part of an electronic apparatus, which may be a STA or an AP, such as a portable or mobile apparatus, a wearable apparatus, a wireless communication apparatus or a computing apparatus. For instance, each of apparatus <NUM> and apparatus <NUM> may be implemented in a smartphone, a smart watch, a personal digital assistant, a digital camera, or a computing equipment such as a tablet computer, a laptop computer or a notebook computer. Each of apparatus <NUM> and apparatus <NUM> may also be a part of a machine type apparatus, which may be an IoT apparatus such as an immobile or a stationary apparatus, a home apparatus, a wire communication apparatus or a computing apparatus. For instance, each of apparatus <NUM> and apparatus <NUM> may be implemented in a smart thermostat, a smart fridge, a smart door lock, a wireless speaker or a home control center. When implemented in or as a network apparatus, apparatus <NUM> and/or apparatus <NUM> may be implemented in a network node, such as an AP in a WLAN.

In some implementations, each of apparatus <NUM> and apparatus <NUM> may be implemented in the form of one or more integrated-circuit (IC) chips such as, for example and without limitation, one or more single-core processors, one or more multicore processors, one or more reduced-instruction set computing (RISC) processors, or one or more complex-instruction-set-computing (CISC) processors. In the various schemes described above, each of apparatus <NUM> and apparatus <NUM> may be implemented in or as a STA or an AP. Each of apparatus <NUM> and apparatus <NUM> includes at least some of those components shown in <FIG> such as a processor <NUM> and a processor <NUM>, respectively, for example. Each of apparatus <NUM> and apparatus <NUM> may further include one or more other components not pertinent to the proposed scheme of the present disclosure (e.g., internal power supply, display device and/or user interface device), and, thus, such component(s) of apparatus <NUM> and apparatus <NUM> are neither shown in <FIG> nor described below in the interest of simplicity and brevity.

In one aspect, each of processor <NUM> and processor <NUM> may be implemented in the form of one or more single-core processors, one or more multicore processors, one or more RISC processors or one or more CISC processors. That is, even though a singular term "a processor" is used herein to refer to processor <NUM> and processor <NUM>, each of processor <NUM> and processor <NUM> may include multiple processors in some implementations and a single processor in other implementations in accordance with the present disclosure. In another aspect, each of processor <NUM> and processor <NUM> may be implemented in the form of hardware (and, optionally, firmware) with electronic components including, for example and without limitation, one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors and/or one or more varactors that are configured and arranged to achieve specific purposes in accordance with the present disclosure. In other words, in at least some implementations, each of processor <NUM> and processor <NUM> is a special-purpose machine specifically designed, arranged and configured to perform specific tasks including those pertaining to efficient TB MU UL transmissions in WLANs in accordance with various implementations of the present disclosure. For instance, each of processor <NUM> and processor <NUM> may be configured with hardware components, or circuitry, implementing one, some or all of the examples described and illustrated herein.

In some implementations, apparatus <NUM> includes a transceiver <NUM> coupled to processor <NUM>. Transceiver <NUM> is capable of wirelessly transmitting and receiving data. In some implementations, apparatus <NUM> also includes a transceiver <NUM> coupled to processor <NUM>. Transceiver <NUM> includes a transceiver capable of wirelessly transmitting and receiving data.

Each of apparatus <NUM> and apparatus <NUM> is a communication entity capable of communicating with each other using various proposed schemes in accordance with the present disclosure. For illustrative purposes and without limitation, a description of capabilities of apparatus <NUM>, as communication entity <NUM> implemented in or as a non-AP STA, and apparatus <NUM>, as communication entity <NUM> implemented in or as an AP STA, is provided below. It is noteworthy that, although the example implementations described below are provided in the context of WLAN, the same may be implemented in other types of networks.

Under at least some of the proposed schemes in accordance with the present disclosure with respect to efficient TB MU UL transmissions in WLANs, processor <NUM> of apparatus <NUM>, implemented in or as a non-AP STA, may receive, via transceiver <NUM>, a trigger frame from apparatus <NUM> as an AP STA, with the trigger frame assigning one or more RUs. Additionally, processor <NUM> may perform, via transceiver <NUM>, a transmission to apparatus <NUM> using the assigned one or more RUs corresponding to one or more subchannels of a plurality of subchannels responsive to receiving the trigger frame, with the one or more subchannels being a subset of the plurality of subchannels in an event that at least one subchannel of the plurality of subchannels is detected as being busy.

In some implementations, prior to receiving the trigger frame from the AP, processor <NUM> may further perform certain operations. For instance, processor <NUM> may perform, via transceiver <NUM>, CCA on the plurality of subchannels. Additionally, processor <NUM> may receive, via transceiver <NUM>, a poll from apparatus <NUM>. Moreover, processor <NUM> may transmit, via transceiver <NUM>, a report to apparatus <NUM> responsive to receiving the poll, with the report indicating status of the plurality of subchannels according to the CCA. In some implementations, the one or more RUs may be assigned by apparatus <NUM> based on the status of the plurality of subchannels according to the CCA as indicated in the report. In such cases, no RU corresponding to the at least one subchannel may be assigned responsive to the at least one subchannel being detected as being busy according to the CCA.

In some implementations, the trigger frame may indicate whether RU downsizing is enabled or otherwise allowed. Moreover, the trigger frame may also indicate a target RSSI as power control information with respect to the assigned one or more RUs.

In some implementations, in performing the transmission using the assigned one or more RUs, processor <NUM> may perform the transmission with RU downsizing by transmitting a TB PPDU to apparatus <NUM> on a downsized RU with the at least one subchannel punctured. In such cases, the downsized RU may be smaller than a size of the assigned one or more RUs responsive to the at least one subchannel being detected as being busy. In some implementations, the TB PPDU may contain a TB-SIG field carrying information on the RU downsizing.

In some implementations, the trigger frame may trigger an UL TB OFDMA transmission. In such cases, the assigned one or more RUs may include a <NUM>-tone RU or <NUM>-tone RU within a primary <NUM> subchannel of the plurality of subchannels. Accordingly, in performing the transmission, processor <NUM> may transmit a status report including CCA status using the assigned <NUM>-tone RU or <NUM>-tone RU. In some implementations, in performing the transmission, processor <NUM> may duplicate a waveform of the primary <NUM> subchannel over an entire bandwidth comprising the plurality of subchannels except the at least one subchannel in an event that the at least one subchannel is detected as being busy.

Under at least some of the proposed schemes in accordance with the present disclosure with respect to efficient TB MU UL transmissions in WLANs, processor <NUM> of apparatus <NUM>, implemented in or as an AP STA, may transmit, via transceiver <NUM>, a trigger frame to apparatus <NUM> as a STA, with the trigger frame assigning one or more RUs. Additionally, processor <NUM> may receive, via transceiver <NUM>, a transmission from apparatus <NUM> on the assigned one or more RUs corresponding to one or more subchannels of a plurality of subchannels responsive to transmitting the trigger frame, with the one or more subchannels being a subset of the plurality of subchannels in an event that at least one subchannel of the plurality of subchannels is detected as being busy.

In some implementations, prior to transmitting the trigger frame to apparatus <NUM>, processor <NUM> may perform certain operations. For instance, processor <NUM> may transmit, via transceiver <NUM>, a poll to apparatus <NUM>. Moreover, processor <NUM> may receive, via transceiver <NUM>, a report from apparatus <NUM> responsive to transmitting the poll, with the report indicating status of the plurality of subchannels according CCA performed by apparatus <NUM> on the plurality of subchannels. In some implementations, the one or more RUs may be assigned by processor <NUM> based on the status of the plurality of subchannels according to the CCA as indicated in the report. In such cases, no RU corresponding to the at least one subchannel may be assigned responsive to the at least one subchannel being detected as being busy according to the CCA.

In some implementations, the trigger frame may indicate whether RU downsizing is enabled or otherwise allowed. In such cases, the trigger frame may further indicate a target RSSI as power control information with respect to the assigned one or more RUs.

In some implementations, in receiving the transmission from apparatus <NUM> on the assigned one or more RUs, processor <NUM> may receive a TB PPDU with RU downsizing by apparatus <NUM> using a downsized RU with the at least one subchannel punctured. In such cases, the downsized RU may be smaller than a size of the assigned one or more RUs responsive to the at least one subchannel being detected as being busy. In some implementations, the TB PPDU may contain a TB-SIG field carrying information on the RU downsizing.

In some implementations, the trigger frame may trigger an UL TB OFDMA transmission from apparatus <NUM>. In such cases, the assigned one or more RUs may include a <NUM>-tone RU or <NUM>-tone RU within a primary <NUM> subchannel of the plurality of subchannels. Accordingly, in receiving the transmission, processor <NUM> may receive a status report including CCA status using the assigned <NUM>-tone RU or <NUM>-tone RU. In some implementations, a waveform of the primary <NUM> subchannel may be duplicated over an entire bandwidth comprising the plurality of subchannels except the at least one subchannel in an event that the at least one subchannel is detected as being busy.

In some implementations, processor <NUM> may perform additional operations. For instance, processor <NUM> may detect, via transceiver <NUM>, whether the transmission is performed by apparatus <NUM> with RU downsizing by performing one or more of the following: (a) decoding either or both of a L-SIG field and a U-SIG field on each of the plurality of subchannels to check a repetition pattern, contents, and a CRC of each of the L-SIG and U-SIG; (b) comparing a RSSI of the received transmission to a target RSSI of each of the plurality of subchannels; and (c) processing either or both of an EHT-STF and one or more EHT-LTFs.

<FIG> illustrates an example process <NUM> in accordance with an implementation of the present disclosure. Process <NUM> may represent an aspect of implementing various proposed designs, concepts, schemes, systems and methods described above. More specifically, process <NUM> may represent an aspect of the proposed concepts and schemes pertaining to efficient TB MU UL transmissions in WLANs in accordance with the present disclosure. Process <NUM> may include one or more operations, actions, or functions as illustrated by one or more of blocks <NUM> and <NUM>. Although illustrated as discrete blocks, various blocks of process <NUM> may be divided into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation. Moreover, the blocks/sub-blocks of process <NUM> may be executed in the order shown in <FIG> or, alternatively in a different order. Furthermore, one or more of the blocks/sub-blocks of process <NUM> may be executed repeatedly or iteratively. Process <NUM> may be implemented by or in apparatus <NUM> and apparatus <NUM> as well as any variations thereof. Solely for illustrative purposes and without limiting the scope, process <NUM> is described below in the context of apparatus <NUM> as communication entity <NUM> (e.g., a non-AP STA) and apparatus <NUM> as communication entity <NUM> (e.g., an AP STA) of a wireless network such as a WLAN in accordance with one or more of IEEE <NUM> standards. Process <NUM> begins at block <NUM>.

At <NUM>, process <NUM> may involve processor <NUM> of apparatus <NUM>, implemented in or as a non-AP STA, receiving, via transceiver <NUM>, a trigger frame from apparatus <NUM> as an AP STA, with the trigger frame assigning one or more RUs. Process <NUM> proceeds from <NUM> to <NUM>.

At <NUM>, process <NUM> may involve processor <NUM> performing, via transceiver <NUM>, a transmission to apparatus <NUM> using the assigned one or more RUs corresponding to one or more subchannels of a plurality of subchannels responsive to receiving the trigger frame, with the one or more subchannels being a subset of the plurality of subchannels in an event that at least one subchannel of the plurality of subchannels is detected as being busy.

In some implementations, prior to receiving the trigger frame from the AP, process <NUM> may further involve processor <NUM> performing certain operations. For instance, process <NUM> may involve processor <NUM> performing, via transceiver <NUM>, CCA on the plurality of subchannels. Additionally, process <NUM> may involve processor <NUM> receiving, via transceiver <NUM>, a poll from apparatus <NUM>. Moreover, process <NUM> may involve processor <NUM> transmitting, via transceiver <NUM>, a report to apparatus <NUM> responsive to receiving the poll, with the report indicating status of the plurality of subchannels according to the CCA. In some implementations, the one or more RUs may be assigned by apparatus <NUM> based on the status of the plurality of subchannels according to the CCA as indicated in the report. In such cases, no RU corresponding to the at least one subchannel may be assigned responsive to the at least one subchannel being detected as being busy according to the CCA.

In some implementations, in performing the transmission using the assigned one or more RUs, process <NUM> may involve processor <NUM> performing the transmission with RU downsizing by transmitting a TB PPDU to apparatus <NUM> on a downsized RU with the at least one subchannel punctured. In such cases, the downsized RU may be smaller than a size of the assigned one or more RUs responsive to the at least one subchannel being detected as being busy. In some implementations, the TB PPDU may contain a TB-SIG field carrying information on the RU downsizing.

In some implementations, the trigger frame may trigger an UL TB OFDMA transmission. In such cases, the assigned one or more RUs may include a <NUM>-tone RU or <NUM>-tone RU within a primary <NUM> subchannel of the plurality of subchannels. Accordingly, in performing the transmission, process <NUM> may involve processor <NUM> transmitting a status report including CCA status using the assigned <NUM>-tone RU or <NUM>-tone RU. In some implementations, in performing the transmission, process <NUM> may further involve processor <NUM> duplicating a waveform of the primary <NUM> subchannel over an entire bandwidth comprising the plurality of subchannels except the at least one subchannel in an event that the at least one subchannel is detected as being busy.

<FIG> illustrates an example process <NUM> in accordance with an implementation of the present disclosure. Process <NUM> may represent an aspect of implementing various proposed designs, concepts, schemes, systems and methods described above. More specifically, process <NUM> may represent an aspect of the proposed concepts and schemes pertaining to efficient TB MU UL transmissions in WLANs in accordance with the present disclosure. Process <NUM> includes one or more operations, actions, or functions as illustrated by one or more of blocks <NUM> and <NUM>. Although illustrated as discrete blocks, various blocks of process <NUM> may be divided into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation. Moreover, the blocks/sub-blocks of process <NUM> may be executed in the order shown in <FIG> or, alternatively in a different order. Furthermore, one or more of the blocks/sub-blocks of process <NUM> may be executed repeatedly or iteratively. Process <NUM> may be implemented by or in apparatus <NUM> and apparatus <NUM> as well as any variations thereof. Solely for illustrative purposes and without limiting the scope, process <NUM> is described below in the context of apparatus <NUM> as communication entity <NUM> (e.g., a non-AP STA) and apparatus <NUM> as communication entity <NUM> (e.g., an AP STA) of a wireless network such as a WLAN in accordance with one or more of IEEE <NUM> standards. Process <NUM> may begin at block <NUM>.

At <NUM>, process <NUM> may involve processor <NUM> of apparatus <NUM>, implemented in or as communication entity <NUM>, transmitting, via transceiver <NUM>, a trigger frame to apparatus <NUM> as a STA, with the trigger frame assigning one or more RUs. Process <NUM> proceeds from <NUM> to <NUM>.

At <NUM>, process <NUM> may involve processor <NUM> receiving, via transceiver <NUM>, a transmission from apparatus <NUM> on the assigned one or more RUs corresponding to one or more subchannels of a plurality of subchannels responsive to transmitting the trigger frame, with the one or more subchannels being a subset of the plurality of subchannels in an event that at least one subchannel of the plurality of subchannels is detected as being busy.

In some implementations, prior to transmitting the trigger frame to apparatus <NUM>, process <NUM> may involve processor <NUM> performing certain operations. For instance, process <NUM> may involve processor <NUM> transmitting, via transceiver <NUM>, a poll to apparatus <NUM>. Moreover, process <NUM> may involve processor <NUM> receiving, via transceiver <NUM>, a report from apparatus <NUM> responsive to transmitting the poll, with the report indicating status of the plurality of subchannels according CCA performed by apparatus <NUM> on the plurality of subchannels. In some implementations, the one or more RUs may be assigned by processor <NUM> based on the status of the plurality of subchannels according to the CCA as indicated in the report. In such cases, no RU corresponding to the at least one subchannel may be assigned responsive to the at least one subchannel being detected as being busy according to the CCA.

In some implementations, in receiving the transmission from apparatus <NUM> on the assigned one or more RUs, process <NUM> may involve processor <NUM> receiving a TB PPDU with RU downsizing by apparatus <NUM> using a downsized RU with the at least one subchannel punctured. In such cases, the downsized RU may be smaller than a size of the assigned one or more RUs responsive to the at least one subchannel being detected as being busy. In some implementations, the TB PPDU may contain a TB-SIG field carrying information on the RU downsizing.

In some implementations, the trigger frame may trigger an UL TB OFDMA transmission from apparatus <NUM>. In such cases, the assigned one or more RUs may include a <NUM>-tone RU or <NUM>-tone RU within a primary <NUM> subchannel of the plurality of subchannels. Accordingly, in receiving the transmission, process <NUM> may involve processor <NUM> receiving a status report including CCA status using the assigned <NUM>-tone RU or <NUM>-tone RU. In some implementations, a waveform of the primary <NUM> subchannel may be duplicated over an entire bandwidth comprising the plurality of subchannels except the at least one subchannel in an event that the at least one subchannel is detected as being busy.

In some implementations, process <NUM> may involve processor <NUM> performing additional operations. For instance, process <NUM> may involve processor <NUM> detecting, via transceiver <NUM>, whether the transmission is performed by apparatus <NUM> with RU downsizing by performing one or more of the following: (a) decoding either or both of a L-SIG field and a U-SIG field on each of the plurality of subchannels to check a repetition pattern, contents, and a CRC of each of the L-SIG and U-SIG; (b) comparing a RSSI of the received transmission to a target RSSI of each of the plurality of subchannels; and (c) processing either or both of an EHT-STF and one or more EHT-LTFs.

Claim 1:
A method, comprising:
receiving a trigger frame from an access point, in the following also referred to as AP, with the trigger frame assigning one or more resource units, in the following also referred to as RUs (<NUM>); and
performing a transmission using the assigned one or more RUs corresponding to one or more subchannels of a plurality of subchannels responsive to receiving the trigger frame (<NUM>),
wherein the one or more subchannels comprise a subset of the plurality of subchannels in an event that at least one subchannel of the plurality of subchannels is detected as being busy;
characterized in that
the performing of the transmission using the assigned one or more RUs comprises performing the transmission with RU downsizing by transmitting a trigger-based, in the following also referred to as TB, physical-layer protocol data unit, in the following also referred to as PPDU, to the AP on a downsized RU, wherein the downsized RU is smaller than a size of the assigned one or more RUs responsive to the at least one subchannel being detected as being busy.