Patent Description:
Wireless network technologies may include various types of wireless local area networks (WLANs). The WLAN employs widely used networking protocols and can be used to interconnect nearby devices together. The various technical features described herein may be applied to any communication standard, such as WiFi or, more generally, any one of the IEEE <NUM> family of wireless protocols. A wireless local area network (WLAN) has been enhanced in various ways. For example, the IEEE <NUM>. 11ax standard has proposed an enhanced communication environment by using orthogonal frequency division multiple access (OFDMA) and downlink multi-user multiple input multiple output (DL MU MIMO) schemes.

The present specification proposes a technical feature that can be utilized in a new communication standard. For example, the new communication standard may be an extreme high throughput (EHT) standard which is currently being discussed. The EHT standard may use an increased bandwidth, an enhanced PHY layer protocol data unit (PPDU) structure, an enhanced sequence, a hybrid automatic repeat request (HARQ) scheme, or the like, which is newly proposed. The EHT standard may be called the IEEE <NUM>. 11be standard.

The prior art document <NPL>, discloses a method to realise synchronous multi-link transmissions with independent backoffs per link. Since the backoffs are rarely reaching zero at the same time, it is proposed to transmit on at least two link as soon as the backoff in one link reaches zero and the other link was idle for at least a duration of PIFS. This allows for synchronised transmission over the links, while respecting DCA rules in all links.

A method performed by a transmitting device in a wireless local area network (Wireless Local Area Network) system as described in independent claim <NUM>.

According to an example of the present specification, a transmitting device may simultaneously transmit PPDU(s) in different links using a multi-link. As a channel access method for simultaneously performing PPDU transmission, PPDU transmission can be performed simultaneously on different links by first waiting until the backoff counter of the other link reaches zero (<NUM>) for the link whose backoff counter reaches zero (<NUM>) first.

In the present specification, "A or B" may mean "only A", "only B" or "both A and B". In other words, in the present specification, "A or B" may be interpreted as "A and/or B". For example, in the present specification, "A, B, or C" may mean "only A", "only B", "only C", or "any combination of A, B, C".

A slash (/) or comma used in the present specification may mean "and/or". For example, "A, B, C" may mean "A, B, or C".

In the present specification, "at least one of A and B" may mean "only A", "only B", or "both A and B". In addition, in the present specification, the expression "at least one of A or B" or "at least one of A and/or B" may be interpreted as "at least one of A and B".

In addition, in the present specification, "at least one of A, B, and C" may mean "only A", "only B", "only C", or "any combination of A, B, and C". In addition, "at least one of A, B, or C" or "at least one of A, B, and/or C" may mean "at least one of A, B, and C".

In addition, a parenthesis used in the present specification may mean "for example". Specifically, when indicated as "control information (EHT-signal)", it may denote that "EHT-signal" is proposed as an example of the "control information". In other words, the "control information" of the present specification is not limited to "EHT-signal", and "EHT-signal" may be proposed as an example of the "control information". In addition, when indicated as "control information (i.e., EHT-signal)", it may also mean that "EHT-signal" is proposed as an example of the "control information".

Technical features described individually in one figure in the present specification may be individually implemented, or may be simultaneously implemented.

The following example of the present specification may be applied to various wireless communication systems. For example, the following example of the present specification may be applied to a wireless local area network (WLAN) system. For example, the present specification may be applied to the IEEE <NUM>. 11a/g/n/ac standard or the IEEE <NUM>. 11ax standard. In addition, the present specification may also be applied to the newly proposed EHT standard or IEEE <NUM>. 11be standard. In addition, the example of the present specification may also be applied to a new WLAN standard enhanced from the EHT standard or the IEEE <NUM> The standard. In addition, the example of the present specification may be applied to a mobile communication system. For example, it may be applied to a mobile communication system based on long term evolution (LTE) depending on a <NUM>rd generation partnership project (3GPP) standard and based on evolution of the LTE. In addition, the example of the present specification may be applied to a communication system of a <NUM> NR standard based on the 3GPP standard.

Hereinafter, in order to describe a technical feature of the present specification, a technical feature applicable to the present specification will be described.

<FIG> shows an example of a transmitting apparatus and/or receiving apparatus of the present specification.

In the example of <FIG>, various technical features described below may be performed. <FIG> relates to at least one station (STA). For example, STAs <NUM> and <NUM> of the present specification may also be called in various terms such as a mobile terminal, a wireless device, a wireless transmit/receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile subscriber unit, or simply a user. The STAs <NUM> and <NUM> of the present specification may also be called in various terms such as a network, a base station, a node-B, an access point (AP), a repeater, a router, a relay, or the like. The STAs <NUM> and <NUM> of the present specification may also be referred to as various names such as a receiving apparatus, a transmitting apparatus, a receiving STA, a transmitting STA, a receiving device, a transmitting device, or the like.

For example, the STAs <NUM> and <NUM> may serve as an AP or a non-AP. That is, the STAs <NUM> and <NUM> of the present specification may serve as the AP and/or the non-AP.

The STAs <NUM> and <NUM> of the present specification may support various communication standards together in addition to the IEEE <NUM> standard. For example, a communication standard (e.g., LTE, LTE-A, 5GNR. standard) or the like based on the 3GPP standard may be supported. In addition, the STA of the present specification may be implemented as various devices such as a mobile phone, a vehicle, a personal computer, or the like. In addition, the STA of the present specification may support communication for various communication services such as voice calls, video calls, data communication, and self-driving (autonomous-driving), or the like.

The STAs <NUM> and <NUM> of the present specification may include a medium access control (MAC) conforming to the IEEE <NUM> standard and a physical layer interface for a radio medium.

The STAs <NUM> and <NUM> will be described below with reference to a sub-figure (a) of <FIG>.

The first STA <NUM> may include a processor <NUM>, a memory <NUM>, and a transceiver <NUM>. The illustrated process, memory, and transceiver may be implemented individually as separate chips, or at least two blocks/functions may be implemented through a single chip.

The transceiver <NUM> of the first STA performs a signal transmission/reception operation. Specifically, an IEEE <NUM> packet (e.g., IEEE <NUM>. 11a/b/g/n/ac/ax/be, etc.) may be transmitted/received.

For example, the first STA <NUM> may perform an operation intended by an AP. For example, the processor <NUM> of the AP may receive a signal through the transceiver <NUM>, process a reception (RX) signal, generate a transmission (TX) signal, and provide control for signal transmission. The memory <NUM> of the AP may store a signal (e.g., RX signal) received through the transceiver <NUM>, and may store a signal (e.g., TX signal) to be transmitted through the transceiver.

For example, the second STA <NUM> may perform an operation intended by a non-AP STA. For example, a transceiver <NUM> of a non-AP performs a signal transmission/reception operation. Specifically, an IEEE <NUM> packet (e.g., IEEE <NUM>. 11a/b/g/n/ac/ax/be packet, etc.) may be transmitted/received.

For example, a processor <NUM> of the non-AP STA may receive a signal through the transceiver <NUM>, process an RX signal, generate a TX signal, and provide control for signal transmission. A memory <NUM> of the non-AP STA may store a signal (e.g., RX signal) received through the transceiver <NUM>, and may store a signal (e.g., TX signal) to be transmitted through the transceiver.

For example, an operation of a device indicated as an AP in the specification described below may be performed in the first STA <NUM> or the second STA <NUM>. For example, if the first STA <NUM> is the AP, the operation of the device indicated as the AP may be controlled by the processor <NUM> of the first STA <NUM>, and a related signal may be transmitted or received through the transceiver <NUM> controlled by the processor <NUM> of the first STA <NUM>. In addition, control information related to the operation of the AP or a TX/RX signal of the AP may be stored in the memory <NUM> of the first STA <NUM>. In addition, if the second STA <NUM> is the AP, the operation of the device indicated as the AP may be controlled by the processor <NUM> of the second STA <NUM>, and a related signal may be transmitted or received through the transceiver <NUM> controlled by the processor <NUM> of the second STA <NUM>. In addition, control information related to the operation of the AP or a TX/RX signal of the AP may be stored in the memory <NUM> of the second STA <NUM>.

For example, in the specification described below, an operation of a device indicated as a non-AP (or user-STA) may be performed in the first STA <NUM> or the second STA <NUM>. For example, if the second STA <NUM> is the non-AP, the operation of the device indicated as the non-AP may be controlled by the processor <NUM> of the second STA <NUM>, and a related signal may be transmitted or received through the transceiver <NUM> controlled by the processor <NUM> of the second STA <NUM>. In addition, control information related to the operation of the non-AP or a TX/RX signal of the non-AP may be stored in the memory <NUM> of the second STA <NUM>. For example, if the first STA <NUM> is the non-AP, the operation of the device indicated as the non-AP may be controlled by the processor <NUM> of the first STA <NUM>, and a related signal may be transmitted or received through the transceiver <NUM> controlled by the processor <NUM> of the first STA <NUM>. In addition, control information related to the operation of the non-AP or a TX/RX signal of the non-AP may be stored in the memory <NUM> of the first STA <NUM>.

In the specification described below, a device called a (transmitting/receiving) STA, a first STA, a second STA, a STA1, a STA2, an AP, a first AP, a second AP, an AP1, an AP2, a (transmitting/receiving) terminal, a (transmitting/receiving) device, a (transmitting/receiving) apparatus, a network, or the like may imply the STAs <NUM> and <NUM> of <FIG>. For example, a device indicated as, without a specific reference numeral, the (transmitting/receiving) STA, the first STA, the second STA, the STA1, the STA2, the AP, the first AP, the second AP, the AP1, the AP2, the (transmitting/receiving) terminal, the (transmitting/receiving) device, the (transmitting/receiving) apparatus, the network, or the like may imply the STAs <NUM> and <NUM> of <FIG>. For example, in the following example, an operation in which various STAs transmit/receive a signal (e.g., a PPDU) may be performed in the transceivers <NUM> and <NUM> of <FIG>. In addition, in the following example, an operation in which various STAs generate a TX/RX signal or perform data processing and computation in advance for the TX/RX signal may be performed in the processors <NUM> and <NUM> of <FIG>. For example, an example of an operation for generating the TX/RX signal or performing the data processing and computation in advance may include: <NUM>) an operation of determining/obtaining/configuring/computing/decoding/encoding bit information of a sub-field (SIG, STF, LTF, Data) included in a PPDU; <NUM>) an operation of determining/configuring/obtaining a time resource or frequency resource (e.g., a subcarrier resource) or the like used for the sub-field (SIG, STF, LTF, Data) included the PPDU; <NUM>) an operation of determining/configuring/obtaining a specific sequence (e.g., a pilot sequence, an STF/LTF sequence, an extra sequence applied to SIG) or the like used for the sub-field (SIG, STF, LTF, Data) field included in the PPDU; <NUM>) a power control operation and/or power saving operation applied for the STA; and <NUM>) an operation related to determining/obtaining/configuring/decoding/encoding or the like of an ACK signal. In addition, in the following example, a variety of information used by various STAs for determining/obtaining/configuring/computing/decoding/decoding a TX/RX signal (e.g., information related to a field/subfield/control field/parameter/power or the like) may be stored in the memories <NUM> and <NUM> of <FIG>.

The aforementioned device/STA of the sub-figure (a) of <FIG> may be modified as shown in the sub-figure (b) of <FIG>. Hereinafter, the STAs <NUM> and <NUM> of the present specification will be described based on the sub-figure (b) of <FIG>.

For example, the transceivers <NUM> and <NUM> illustrated in the sub-figure (b) of <FIG> may perform the same function as the aforementioned transceiver illustrated in the sub-figure (a) of <FIG>. For example, processing chips <NUM> and <NUM> illustrated in the sub-figure (b) of <FIG> may include the processors <NUM> and <NUM> and the memories <NUM> and <NUM>. The processors <NUM> and <NUM> and memories <NUM> and <NUM> illustrated in the sub-figure (b) of <FIG> may perform the same function as the aforementioned processors <NUM> and <NUM> and memories <NUM> and <NUM> illustrated in the sub-figure (a) of <FIG>.

A mobile terminal, a wireless device, a wireless transmit/receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile subscriber unit, a user, a user STA, a network, a base station, a Node-B, an access point (AP), a repeater, a router, a relay, a receiving unit, a transmitting unit, a receiving STA, a transmitting STA, a receiving device, a transmitting device, a receiving apparatus, and/or a transmitting apparatus, which are described below, may imply the STAs <NUM> and <NUM> illustrated in the sub-figure (a)/(b) of <FIG>, or may imply the processing chips <NUM> and <NUM> illustrated in the sub-figure (b) of <FIG>. That is, a technical feature of the present specification may be performed in the STAs <NUM> and <NUM> illustrated in the sub-figure (a)/(b) of <FIG>, or may be performed only in the processing chips <NUM> and <NUM> illustrated in the sub-figure (b) of <FIG>. For example, a technical feature in which the transmitting STA transmits a control signal may be understood as a technical feature in which a control signal generated in the processors <NUM> and <NUM> illustrated in the sub-figure (a)/(b) of <FIG> is transmitted through the transceivers <NUM> and <NUM> illustrated in the sub-figure (a)/(b) of <FIG>. Alternatively, the technical feature in which the transmitting STA transmits the control signal may be understood as a technical feature in which the control signal to be transferred to the transceivers <NUM> and <NUM> is generated in the processing chips <NUM> and <NUM> illustrated in the sub-figure (b) of <FIG>.

For example, a technical feature in which the receiving STA receives the control signal may be understood as a technical feature in which the control signal is received by means of the transceivers <NUM> and <NUM> illustrated in the sub-figure (a) of <FIG>. Alternatively, the technical feature in which the receiving STA receives the control signal may be understood as the technical feature in which the control signal received in the transceivers <NUM> and <NUM> illustrated in the sub-figure (a) of <FIG> is obtained by the processors <NUM> and <NUM> illustrated in the sub-figure (a) of <FIG>. Alternatively, the technical feature in which the receiving STA receives the control signal may be understood as the technical feature in which the control signal received in the transceivers <NUM> and <NUM> illustrated in the sub-figure (b) of <FIG> is obtained by the processing chips <NUM> and <NUM> illustrated in the sub-figure (b) of <FIG>.

Referring to the sub-figure (b) of <FIG>, software codes <NUM> and <NUM> may be included in the memories <NUM> and <NUM>. The software codes <NUM> and <NUM> may include instructions for controlling an operation of the processors <NUM> and <NUM>. The software codes <NUM> and <NUM> may be included as various programming languages.

The processors <NUM> and <NUM> or processing chips <NUM> and <NUM> of <FIG> may include an application-specific integrated circuit (ASIC), other chipsets, a logic circuit and/or a data processing device. The processor may be an application processor (AP). For example, the processors <NUM> and <NUM> or processing chips <NUM> and <NUM> of <FIG> may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modulator and demodulator (modem). For example, the processors <NUM> and <NUM> or processing chips <NUM> and <NUM> of <FIG> may be SNAPDRAGONTM series of processors made by Qualcomm®, EXYNOSTM series of processors made by Samsung®, A series of processors made by Apple®, HELIOTM series of processors made by MediaTek®, ATOMTM series of processors made by Intel® or processors enhanced from these processors.

In the present specification, an uplink may imply a link for communication from a non-AP STA to an SP STA, and an uplink PPDU/packet/signal or the like may be transmitted through the uplink. In addition, in the present specification, a downlink may imply a link for communication from the AP STA to the non-AP STA, and a downlink PPDU/packet/signal or the like may be transmitted through the downlink.

<FIG> is a conceptual view illustrating the structure of a wireless local area network (WLAN).

An upper part of <FIG> illustrates the structure of an infrastructure basic service set (BSS) of institute of electrical and electronic engineers (IEEE) <NUM>.

Referring the upper part of <FIG>, the wireless LAN system may include one or more infrastructure BSSs <NUM> and <NUM> (hereinafter, referred to as BSS). The BSSs <NUM> and <NUM> as a set of an AP and a STA such as an access point (AP) <NUM> and a station (STA1) <NUM>-<NUM> which are successfully synchronized to communicate with each other are not concepts indicating a specific region. The BSS <NUM> may include one or more STAs <NUM>-<NUM> and <NUM>-<NUM> which may be joined to one AP <NUM>.

The BSS may include at least one STA, APs providing a distribution service, and a distribution system (DS) <NUM> connecting multiple APs.

The distribution system <NUM> may implement an extended service set (ESS) <NUM> extended by connecting the multiple BSSs <NUM> and <NUM>. The ESS <NUM> may be used as a term indicating one network configured by connecting one or more APs <NUM> or <NUM> through the distribution system <NUM>. The AP included in one ESS <NUM> may have the same service set identification (SSID).

A portal <NUM> may serve as a bridge which connects the wireless LAN network (IEEE <NUM>) and another network (e.g., <NUM>.

In the BSS illustrated in the upper part of <FIG>, a network between the APs <NUM> and <NUM> and a network between the APs <NUM> and <NUM> and the STAs <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> may be implemented. However, the network is configured even between the STAs without the APs <NUM> and <NUM> to perform communication. A network in which the communication is performed by configuring the network even between the STAs without the APs <NUM> and <NUM> is defined as an Ad-Hoc network or an independent basic service set (IBSS).

A lower part of <FIG> illustrates a conceptual view illustrating the IBSS.

Referring to the lower part of <FIG>, the IBSS is a BSS that operates in an Ad-Hoc mode. Since the IBSS does not include the access point (AP), a centralized management entity that performs a management function at the center does not exist. That is, in the IBSS, STAs <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> are managed by a distributed manner. In the IBSS, all STAs <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> may be constituted by movable STAs and are not permitted to access the DS to constitute a self-contained network.

<FIG> illustrates a general link setup process.

In S310, a STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, to access a network, the STA needs to discover a participating network. The STA needs to identify a compatible network before participating in a wireless network, and a process of identifying a network present in a particular area is referred to as scanning. Scanning methods include active scanning and passive scanning.

<FIG> illustrates a network discovery operation including an active scanning process. In active scanning, a STA performing scanning transmits a probe request frame and waits for a response to the probe request frame in order to identify which AP is present around while moving to channels. A responder transmits a probe response frame as a response to the probe request frame to the STA having transmitted the probe request frame. Here, the responder may be a STA that transmits the last beacon frame in a BSS of a channel being scanned. In the BSS, since an AP transmits a beacon frame, the AP is the responder. In an IBSS, since STAs in the IBSS transmit a beacon frame in turns, the responder is not fixed. For example, when the STA transmits a probe request frame via channel <NUM> and receives a probe response frame via channel <NUM>, the STA may store BSS-related information included in the received probe response frame, may move to the next channel (e.g., channel <NUM>), and may perform scanning (e.g., transmits a probe request and receives a probe response via channel <NUM>) by the same method.

Although not shown in <FIG>, scanning may be performed by a passive scanning method. In passive scanning, a STA performing scanning may wait for a beacon frame while moving to channels. A beacon frame is one of management frames in IEEE <NUM> and is periodically transmitted to indicate the presence of a wireless network and to enable the STA performing scanning to find the wireless network and to participate in the wireless network. In a BSS, an AP serves to periodically transmit a beacon frame. In an IBSS, STAs in the IBSS transmit a beacon frame in turns. Upon receiving the beacon frame, the STA performing scanning stores information related to a BSS included in the beacon frame and records beacon frame information in each channel while moving to another channel. The STA having received the beacon frame may store BSS-related information included in the received beacon frame, may move to the next channel, and may perform scanning in the next channel by the same method.

After discovering the network, the STA may perform an authentication process in S320. The authentication process may be referred to as a first authentication process to be clearly distinguished from the following security setup operation in S340. The authentication process in S320 may include a process in which the STA transmits an authentication request frame to the AP and the AP transmits an authentication response frame to the STA in response. The authentication frames used for an authentication request/response are management frames.

The authentication frames may include information related to an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a robust security network (RSN), and a finite cyclic group.

The STA may transmit the authentication request frame to the AP. The AP may determine whether to allow the authentication of the STA based on the information included in the received authentication request frame. The AP may provide the authentication processing result to the STA via the authentication response frame.

When the STA is successfully authenticated, the STA may perform an association process in S330. The association process includes a process in which the STA transmits an association request frame to the AP and the AP transmits an association response frame to the STA in response. The association request frame may include, for example, information related to various capabilities, a beacon listen interval, a service set identifier (SSID), a supported rate, a supported channel, RSN, a mobility domain, a supported operating class, a traffic indication map (TIM) broadcast request, and an interworking service capability. The association response frame may include, for example, information related to various capabilities, a status code, an association ID (AID), a supported rate, an enhanced distributed channel access (EDCA) parameter set, a received channel power indicator (RCPI), a received signal-to-noise indicator (RSNI), a mobility domain, a timeout interval (association comeback time), an overlapping BSS scanning parameter, a TIM broadcast response, and a QoS map.

In S340, the STA may perform a security setup process. The security setup process in S340 may include a process of setting up a private key through four-way handshaking, for example, through an extensible authentication protocol over LAN (EAPOL) frame.

<FIG> illustrates an example of a PPDU used in an IEEE standard.

As illustrated, various types of PHY protocol data units (PPDUs) are used in IEEE a/g/n/ac standards. Specifically, an LTF and a STF include a training signal, a SIG-A and a SIG-B include control information for a receiving STA, and a data field includes user data corresponding to a PSDU (MAC PDU/aggregated MAC PDU).

<FIG> also includes an example of an HE PPDU according to IEEE <NUM>. The HE PPDU according to <FIG> is an illustrative PPDU for multiple users. An HE-SIG-B may be included only in a PPDU for multiple users, and an HE-SIG-B may be omitted in a PPDU for a single user.

As illustrated in <FIG>, the HE-PPDU for multiple users (MUs) may include a legacy-short training field (L-STF), a legacy-long training field (L-LTF), a legacy-signal (L-SIG), a high efficiency-signal A (HE-SIG A), a high efficiency-signal-B (HE-SIG B), a high efficiency-short training field (HE-STF), a high efficiency-long training field (HE-LTF), a data field (alternatively, an MAC payload), and a packet extension (PE) field. The respective fields may be transmitted for illustrated time periods (i.e., <NUM> or <NUM>).

Hereinafter, a resource unit (RU) used for a PPDU is described. An RU may include a plurality of subcarriers (or tones). An RU may be used to transmit a signal to a plurality of STAs according to OFDMA. Further, an RU may also be defined to transmit a signal to one STA. An RU may be used for an STF, an LTF, a data field, or the like.

<FIG> illustrates a layout of resource units (RUs) used in a band of <NUM>.

As illustrated in <FIG>, resource units (RUs) corresponding to different numbers of tones (i.e., subcarriers) may be used to form some fields of an HE-PPDU. For example, resources may be allocated in illustrated RUs for an HE-STF, an HE-LTF, and a data field.

As illustrated in the uppermost part of <FIG>, a <NUM>-unit (i.e., a unit corresponding to <NUM> tones) may be disposed. Six tones may be used for a guard band in the leftmost band of the <NUM> band, and five tones may be used for a guard band in the rightmost band of the <NUM> band. Further, seven DC tones may be inserted in a center band, that is, a DC band, and a <NUM>-unit corresponding to <NUM> tones on each of the left and right sides of the DC band may be disposed. A <NUM>-unit, a <NUM>-unit, and a <NUM>-unit may be allocated to other bands. Each unit may be allocated for a receiving STA, that is, a user.

The layout of the RUs in <FIG> may be used not only for a multiple users (MUs) but also for a single user (SU), in which case one <NUM>-unit may be used and three DC tones may be inserted as illustrated in the lowermost part of <FIG>.

Although <FIG> proposes RUs having various sizes, that is, a <NUM>-RU, a <NUM>-RU, a <NUM>-RU, and a <NUM>-RU, specific sizes of RUs may be extended or increased. Therefore, the present embodiment is not limited to the specific size of each RU (i.e., the number of corresponding tones).

<FIG> illustrates a layout of RUs used in a band of <NUM>.

Similarly to <FIG> in which RUs having various sizes are used, a <NUM>-RU, a <NUM>-RU, a <NUM>-RU, a <NUM>-RU, a <NUM>-RU, and the like may be used in an example of <FIG>. Further, five DC tones may be inserted in a center frequency, <NUM> tones may be used for a guard band in the leftmost band of the <NUM> band, and <NUM> tones may be used for a guard band in the rightmost band of the <NUM> band.

As illustrated in <FIG>, when the layout of the RUs is used for a single user, a <NUM>-RU may be used. The specific number of RUs may be changed similarly to <FIG>.

Similarly to <FIG> and <FIG> in which RUs having various sizes are used, a <NUM>-RU, a <NUM>-RU, a <NUM>-RU, a <NUM>-RU, a <NUM>-RU, a <NUM>-RU, and the like may be used in an example of <FIG>. Further, seven DC tones may be inserted in the center frequency, <NUM> tones may be used for a guard band in the leftmost band of the <NUM> band, and <NUM> tones may be used for a guard band in the rightmost band of the <NUM> band. In addition, a <NUM>-RU corresponding to <NUM> tones on each of the left and right sides of the DC band may be used.

As illustrated in <FIG>, when the layout of the RUs is used for a single user, a <NUM>-RU may be used, in which case five DC tones may be inserted.

The RU described in the present specification may be used in uplink (UL) communication and downlink (DL) communication. For example, when UL-MU communication which is solicited by a trigger frame is performed, a transmitting STA (e.g., an AP) may allocate a first RU (e.g., <NUM>/<NUM>/<NUM>/<NUM>-RU, etc.) to a first STA through the trigger frame, and may allocate a second RU (e.g., <NUM>/<NUM>/<NUM>/<NUM>-RU, etc.) to a second STA. Thereafter, the first STA may transmit a first trigger-based PPDU based on the first RU, and the second STA may transmit a second trigger-based PPDU based on the second RU. The first/second trigger-based PPDU is transmitted to the AP at the same (or overlapped) time period.

For example, when a DL MU PPDU is configured, the transmitting STA (e.g., AP) may allocate the first RU (e.g., <NUM>/<NUM>/<NUM>/<NUM>-RU. etc.) to the first STA, and may allocate the second RU (e.g., <NUM>/<NUM>/<NUM>/<NUM>-RU, etc.) to the second STA. That is, the transmitting STA (e.g., AP) may transmit HE-STF, HE-LTF, and Data fields for the first STA through the first RU in one MU PPDU, and may transmit HE-STF, HE-LTF, and Data fields for the second STA through the second RU.

Information related to a layout of the RU may be signaled through HE-SIG-B.

<FIG> illustrates a structure of an HE-SIG-B field.

As illustrated, an HE-SIG-B field <NUM> includes a common field <NUM> and a user-specific field <NUM>. The common field <NUM> may include information commonly applied to all users (i.e., user STAs) which receive SIG-B. The user-specific field <NUM> may be called a user-specific control field. When the SIG-B is transferred to a plurality of users, the user-specific field <NUM> may be applied only any one of the plurality of users.

As illustrated in <FIG>, the common field <NUM> and the user-specific field <NUM> may be separately encoded.

The common field <NUM> may include RU allocation information of N*<NUM> bits. For example, the RU allocation information may include information related to a location of an RU. For example, when a <NUM> channel is used as shown in <FIG>, the RU allocation information may include information related to a specific frequency band to which a specific RU (<NUM>-RU/<NUM>-RU/<NUM>-RU) is arranged.

An example of a case in which the RU allocation information consists of <NUM> bits is as follows.

As shown the example of <FIG>, up to nine <NUM>-RUs may be allocated to the <NUM> channel. When the RU allocation information of the common field <NUM> is set to "<NUM>" as shown in Table <NUM>, the nine <NUM>-RUs may be allocated to a corresponding channel (i.e., <NUM>). In addition, when the RU allocation information of the common field <NUM> is set to "<NUM>" as shown in Table <NUM>, seven <NUM>-RUs and one <NUM>-RU are arranged in a corresponding channel. That is, in the example of <FIG>, the <NUM>-RU may be allocated to the rightmost side, and the seven <NUM>-RUs may be allocated to the left thereof.

The example of Table <NUM> shows only some of RU locations capable of displaying the RU allocation information.

For example, the RU allocation information may include an example of Table <NUM> below.

"01000y2y1y0" relates to an example in which a <NUM>-RU is allocated to the leftmost side of the <NUM> channel, and five <NUM>-RUs are allocated to the right side thereof. In this case, a plurality of STAs (e.g., user-STAs) may be allocated to the <NUM>-RU, based on a MU-MIMO scheme. Specifically, up to <NUM> STAs (e.g., user-STAs) may be allocated to the <NUM>-RU, and the number of STAs (e.g., user-STAs) allocated to the <NUM>-RU is determined based on <NUM>-bit information (y2y1y0). For example, when the <NUM>-bit information (y2y1y0) is set to N, the number of STAs (e.g., user-STAs) allocated to the <NUM>-RU based on the MU-MIMO scheme may be N+<NUM>.

In general, a plurality of STAs (e.g., user STAs) different from each other may be allocated to a plurality of RUs. However, the plurality of STAs (e.g., user STAs) may be allocated to one or more RUs having at least a specific size (e.g., <NUM> subcarriers), based on the MU-MIMO scheme.

As shown in <FIG>, the user-specific field <NUM> may include a plurality of user fields. As described above, the number of STAs (e.g., user STAs) allocated to a specific channel may be determined based on the RU allocation information of the common field <NUM>. For example, when the RU allocation information of the common field <NUM> is "<NUM>", one user STA may be allocated to each of nine <NUM>-RUs (e.g., nine user STAs may be allocated). That is, up to <NUM> user STAs may be allocated to a specific channel through an OFDMA scheme. In other words, up to <NUM> user STAs may be allocated to a specific channel through a non-MU-MIMO scheme.

For example, when RU allocation is set to "01000y2y1y0", a plurality of STAs may be allocated to the <NUM>-RU arranged at the leftmost side through the MU-MIMO scheme, and five user STAs may be allocated to five <NUM>-RUs arranged to the right side thereof through the non-MU MIMO scheme. This case is specified through an example of <FIG>.

<FIG> illustrates an example in which a plurality of user STAs are allocated to the same RU through a MU-MIMO scheme.

For example, when RU allocation is set to "<NUM>" as shown in <FIG>, a <NUM>-RU may be allocated to the leftmost side of a specific channel, and five <NUM>-RUs may be allocated to the right side thereof. In addition, three user STAs may be allocated to the <NUM>-RU through the MU-MIMO scheme. As a result, since eight user STAs are allocated, the user-specific field <NUM> of HE-SIG-B may include eight user fields.

The eight user fields may be expressed in the order shown in <FIG>. In addition, as shown in <FIG>, two user fields may be implemented with one user block field.

The user fields shown in <FIG> and <FIG> may be configured based on two formats. That is, a user field related to a MU-MIMO scheme may be configured in a first format, and a user field related to a non-MIMO scheme may be configured in a second format. Referring to the example of <FIG>, a user field <NUM> to a user field <NUM> may be based on the first format, and a user field <NUM> to a user field <NUM> may be based on the second format. The first format or the second format may include bit information of the same length (e.g., <NUM> bits).

Each user field may have the same size (e.g., <NUM> bits). For example, the user field of the first format (the first of the MU-MIMO scheme) may be configured as follows.

For example, a first bit (i.e., B0-B10) in the user field (i.e., <NUM> bits) may include identification information (e.g., STA-ID, partial AID, etc.) of a user STA to which a corresponding user field is allocated. In addition, a second bit (i.e., B11-B14) in the user field (i.e., <NUM> bits) may include information related to a spatial configuration. Specifically, an example of the second bit (i.e., B11-B14) may be as shown in Table <NUM> and Table <NUM> below.

As shown in Table <NUM> and/or Table <NUM>, the second bit (e.g., B11-B14) may include information related to the number of spatial streams allocated to the plurality of user STAs which are allocated based on the MU-MIMO scheme. For example, when three user STAs are allocated to the <NUM>-RU based on the MU-MIMO scheme as shown in <FIG>, N_user is set to "<NUM>". Therefore, values of N_STS[<NUM>], N_STS[<NUM>], and N_STS[<NUM>] may be determined as shown in Table <NUM>. For example, when a value of the second bit (B11-B14) is "<NUM>", it may be set to N_STS[<NUM>]=<NUM>, N_STS[<NUM>]=<NUM>, N_STS[<NUM>]=<NUM>. That is, in the example of <FIG>, four spatial streams may be allocated to the user field <NUM>, one spatial stream may be allocated to the user field <NUM>, and one spatial stream may be allocated to the user field <NUM>.

As shown in the example of Table <NUM> and/or Table <NUM>, information (i.e., the second bit, B11-B14) related to the number of spatial streams for the user STA may consist of <NUM> bits. In addition, the information (i.e., the second bit, B11-B14) on the number of spatial streams for the user STA may support up to eight spatial streams. In addition, the information (i.e., the second bit, B11-B14) on the number of spatial streams for the user STA may support up to four spatial streams for one user STA.

In addition, a third bit (i.e., B15-<NUM>) in the user field (i.e., <NUM> bits) may include modulation and coding scheme (MCS) information. The MCS information may be applied to a data field in a PPDU including corresponding SIG-B.

An MCS, MCS information, an MCS index, an MCS field, or the like used in the present specification may be indicated by an index value. For example, the MCS information may be indicated by an index <NUM> to an index <NUM>. The MCS information may include information related to a constellation modulation type (e.g., BPSK, QPSK, <NUM>-QAM, <NUM>-QAM, <NUM>-QAM, <NUM>-QAM, etc.) and information related to a coding rate (e.g., <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/6e, etc.). Information related to a channel coding type (e.g., LCC or LDPC) may be excluded in the MCS information.

In addition, a fourth bit (i.e., B19) in the user field (i.e., <NUM> bits) may be a reserved field.

In addition, a fifth bit (i.e., B20) in the user field (i.e., <NUM> bits) may include information related to a coding type (e.g., BCC or LDPC). That is, the fifth bit (i.e., B20) may include information related to a type (e.g., BCC or LDPC) of channel coding applied to the data field in the PPDU including the corresponding SIG-B.

The aforementioned example relates to the user field of the first format (the format of the MU-MIMO scheme). An example of the user field of the second format (the format of the non-MU-MIMO scheme) is as follows.

A first bit (e.g., B0-B10) in the user field of the second format may include identification information of a user STA. In addition, a second bit (e.g., B11-B13) in the user field of the second format may include information related to the number of spatial streams applied to a corresponding RU. In addition, a third bit (e.g., B14) in the user field of the second format may include information related to whether a beamforming steering matrix is applied. A fourth bit (e.g., B15-B18) in the user field of the second format may include modulation and coding scheme (MCS) information. In addition, a fifth bit (e.g., B19) in the user field of the second format may include information related to whether dual carrier modulation (DCM) is applied. In addition, a sixth bit (i.e., B20) in the user field of the second format may include information related to a coding type (e.g., BCC or LDPC).

<FIG> illustrates an operation based on UL-MU. As illustrated, a transmitting STA (e.g., an AP) may perform channel access through contending (e.g., a backoff operation), and may transmit a trigger frame <NUM>. That is, the transmitting STA may transmit a PPDU including the trigger frame <NUM>. Upon receiving the PPDU including the trigger frame, a trigger-based (TB) PPDU is transmitted after a delay corresponding to SIFS.

TB PPDUs <NUM> and <NUM> may be transmitted at the same time period, and may be transmitted from a plurality of STAs (e.g., user STAs) having AIDs indicated in the trigger frame <NUM>. An ACK frame <NUM> for the TB PPDU may be implemented in various forms.

A specific feature of the trigger frame is described with reference to <FIG>. Even if UL-MU communication is used, an orthogonal frequency division multiple access (OFDMA) scheme or a MU MIMO scheme may be used, and the OFDMA and MU-MIMO schemes may be simultaneously used.

<FIG> illustrates an example of a trigger frame. The trigger frame of <FIG> allocates a resource for uplink multiple-user (MU) transmission, and may be transmitted, for example, from an AP. The trigger frame may be configured of a MAC frame, and may be included in a PPDU.

Each field shown in <FIG> may be partially omitted, and another field may be added. In addition, a length of each field may be changed to be different from that shown in the figure.

A frame control field <NUM> of <FIG> may include information related to a MAC protocol version and extra additional control information. A duration field <NUM> may include time information for NAV configuration or information related to an identifier (e.g., AID) of a STA.

In addition, an RA field <NUM> may include address information of a receiving STA of a corresponding trigger frame, and may be optionally omitted. A TA field <NUM> may include address information of a STA (e.g., an AP) which transmits the corresponding trigger frame. A common information field <NUM> includes common control information applied to the receiving STA which receives the corresponding trigger frame. For example, a field indicating a length of an L-SIG field of an uplink PPDU transmitted in response to the corresponding trigger frame or information for controlling content of a SIG-A field (i.e., HE-SIG-A field) of the uplink PPDU transmitted in response to the corresponding trigger frame may be included. In addition, as common control information, information related to a length of a CP of the uplink PPDU transmitted in response to the corresponding trigger frame or information related to a length of an LTF field may be included.

In addition, per user information fields <NUM>#<NUM> to <NUM>#N corresponding to the number of receiving STAs which receive the trigger frame of <FIG> are preferably included. The per user information field may also be called an "allocation field".

In addition, the trigger frame of <FIG> may include a padding field <NUM> and a frame check sequence field <NUM>.

Each of the per user information fields <NUM>#<NUM> to <NUM>#N shown in <FIG> may include a plurality of subfields.

<FIG> illustrates an example of a common information field of a trigger frame. A subfield of <FIG> may be partially omitted, and an extra subfield may be added. In addition, a length of each subfield illustrated may be changed.

A length field <NUM> illustrated has the same value as a length field of an L-SIG field of an uplink PPDU transmitted in response to a corresponding trigger frame, and a length field of the L-SIG field of the uplink PPDU indicates a length of the uplink PPDU. As a result, the length field <NUM> of the trigger frame may be used to indicate the length of the corresponding uplink PPDU.

In addition, a cascade identifier field <NUM> indicates whether a cascade operation is performed. The cascade operation implies that downlink MU transmission and uplink MU transmission are performed together in the same TXOP. That is, it implies that downlink MU transmission is performed and thereafter uplink MU transmission is performed after a pre-set time (e.g., SIFS). During the cascade operation, only one transmitting device (e.g., AP) may perform downlink communication, and a plurality of transmitting devices (e.g., non-APs) may perform uplink communication.

A CS request field <NUM> indicates whether a wireless medium state or a NAV or the like is necessarily considered in a situation where a receiving device which has received a corresponding trigger frame transmits a corresponding uplink PPDU.

An HE-SIG-A information field <NUM> may include information for controlling content of a SIG-A field (i.e., HE-SIG-A field) of the uplink PPDU in response to the corresponding trigger frame.

A CP and LTF type field <NUM> may include information related to a CP length and LTF length of the uplink PPDU transmitted in response to the corresponding trigger frame. A trigger type field <NUM> may indicate a purpose of using the corresponding trigger frame, for example, typical triggering, triggering for beamforming, a request for block ACK/NACK, or the like.

It may be assumed that the trigger type field <NUM> of the trigger frame in the present specification indicates a trigger frame of a basic type for typical triggering. For example, the trigger frame of the basic type may be referred to as a basic trigger frame.

<FIG> illustrates an example of a subfield included in a per user information field. A user information field <NUM> of <FIG> may be understood as any one of the per user information fields <NUM>#<NUM> to <NUM>#N mentioned above with reference to <FIG>. A subfield included in the user information field <NUM> of <FIG> may be partially omitted, and an extra subfield may be added. In addition, a length of each subfield illustrated may be changed.

A user identifier field <NUM> of <FIG> indicates an identifier of a STA (i.e., receiving STA) corresponding to per user information. An example of the identifier may be the entirety or part of an association identifier (AID) value of the receiving STA.

In addition, an RU allocation field <NUM> may be included. That is, when the receiving STA identified through the user identifier field <NUM> transmits a TB PPDU in response to the trigger frame, the TB PPDU is transmitted through an RU indicated by the RU allocation field <NUM>. In this case, the RU indicated by the RU allocation field <NUM> may be an RU shown in <FIG>, <FIG>, and <FIG>.

The subfield of <FIG> may include a coding type field <NUM>. The coding type field <NUM> may indicate a coding type of the TB PPDU. For example, when BCC coding is applied to the TB PPDU, the coding type field <NUM> may be set to '<NUM>', and when LDPC coding is applied, the coding type field <NUM> may be set to `<NUM>'.

In addition, the subfield of <FIG> may include an MCS field <NUM>. The MCS field <NUM> may indicate an MCS scheme applied to the TB PPDU. For example, when BCC coding is applied to the TB PPDU, the coding type field <NUM> may be set to '<NUM>', and when LDPC coding is applied, the coding type field <NUM> may be set to `<NUM>'.

Hereinafter, a UL OFDMA-based random access (UORA) scheme will be described.

<FIG> describes a technical feature of the UORA scheme.

A transmitting STA (e.g., an AP) may allocate six RU resources through a trigger frame as shown in <FIG>. Specifically, the AP may allocate a 1st RU resource (AID <NUM>, RU <NUM>), a 2nd RU resource (AID <NUM>, RU <NUM>), a 3rd RU resource (AID <NUM>, RU <NUM>), a 4th RU resource (AID <NUM>, RU <NUM>), a 5th RU resource (AID <NUM>, RU <NUM>), and a 6th RU resource (AID <NUM>, RU <NUM>). Information related to the AID <NUM>, AID <NUM>, or AID <NUM> may be included, for example, in the user identifier field <NUM> of <FIG>. Information related to the RU <NUM> to RU <NUM> may be included, for example, in the RU allocation field <NUM> of <FIG>. AID=<NUM> may imply a UORA resource for an associated STA, and AID=<NUM> may imply a UORA resource for an un-associated STA. Accordingly, the 1st to 3rd RU resources of <FIG> may be used as a UORA resource for the associated STA, the 4th and 5th RU resources of <FIG> may be used as a UORA resource for the un-associated STA, and the 6th RU resource of <FIG> may be used as a typical resource for UL MU.

In the example of <FIG>, an OFDMA random access backoff (OBO) of a STA1 is decreased to <NUM>, and the STA1 randomly selects the 2nd RU resource (AID <NUM>, RU <NUM>). In addition, since an OBO counter of a STA2/<NUM> is greater than <NUM>, an uplink resource is not allocated to the STA2/<NUM>. In addition, regarding a STA4 in <FIG>, since an AID (e.g., AID=<NUM>) of the STA4 is included in a trigger frame, a resource of the RU <NUM> is allocated without backoff.

Specifically, since the STA1 of <FIG> is an associated STA, the total number of eligible RA RUs for the STA1 is <NUM> (RU <NUM>, RU <NUM>, and RU <NUM>), and thus the STA1 decreases an OBO counter by <NUM> so that the OBO counter becomes <NUM>. In addition, since the STA2 of <FIG> is an associated STA, the total number of eligible RA RUs for the STA2 is <NUM> (RU <NUM>, RU <NUM>, and RU <NUM>), and thus the STA2 decreases the OBO counter by <NUM> but the OBO counter is greater than <NUM>. In addition, since the STA3 of <FIG> is an un-associated STA, the total number of eligible RA RUs for the STA3 is <NUM> (RU <NUM>, RU <NUM>), and thus the STA3 decreases the OBO counter by <NUM> but the OBO counter is greater than <NUM>.

<FIG> illustrates an example of a channel used/supported/defined within a <NUM> band.

The <NUM> band may be called in other terms such as a first band. In addition, the <NUM> band may imply a frequency domain in which channels of which a center frequency is close to <NUM> (e.g., channels of which a center frequency is located within <NUM> to <NUM>) are used/supported/defined.

A plurality of <NUM> channels may be included in the <NUM> band. <NUM> within the <NUM> may have a plurality of channel indices (e.g., an index <NUM> to an index <NUM>). For example, a center frequency of a <NUM> channel to which a channel index <NUM> is allocated may be <NUM>, a center frequency of a <NUM> channel to which a channel index <NUM> is allocated may be <NUM>, and a center frequency of a <NUM> channel to which a channel index N is allocated may be (<NUM> + <NUM>*N) GHz. The channel index may be called in various terms such as a channel number or the like. Specific numerical values of the channel index and center frequency may be changed.

<FIG> exemplifies <NUM> channels within a <NUM> band. Each of 1st to 4th frequency domains <NUM> to <NUM> shown herein may include one channel. For example, the 1st frequency domain <NUM> may include a channel <NUM> (a <NUM> channel having an index <NUM>). In this case, a center frequency of the channel <NUM> may be set to <NUM>. The 2nd frequency domain <NUM> may include a channel <NUM>. In this case, a center frequency of the channel <NUM> may be set to <NUM>. The 3rd frequency domain <NUM> may include a channel <NUM>. In this case, a center frequency of the channel <NUM> may be set to <NUM>. The 4th frequency domain <NUM> may include a channel <NUM>. In this case, a center frequency of the channel <NUM> may be set to <NUM>.

The <NUM> band may be called in other terms such as a second band or the like. The <NUM> band may imply a frequency domain in which channels of which a center frequency is greater than or equal to <NUM> and less than <NUM> (or less than <NUM>) are used/supported/defined. Alternatively, the <NUM> band may include a plurality of channels between <NUM> and <NUM>. A specific numerical value shown in <FIG> may be changed.

A plurality of channels within the <NUM> band include an unlicensed national information infrastructure (UNII)-<NUM>, a UNII-<NUM>, a UNII-<NUM>, and an ISM. The INII-<NUM> may be called UNII Low. The UNII-<NUM> may include a frequency domain called UNII Mid and UNII-2Extended. The UNII-<NUM> may be called UNII-Upper.

A plurality of channels may be configured within the <NUM> band, and a bandwidth of each channel may be variously set to, for example, <NUM>, <NUM>, <NUM>, <NUM>, or the like. For example, <NUM> to <NUM> frequency domains/ranges within the UNII-<NUM> and UNII-<NUM> may be divided into eight <NUM> channels. The <NUM> to <NUM> frequency domains/ranges may be divided into four channels through a <NUM> frequency domain. The <NUM> to <NUM> frequency domains/ranges may be divided into two channels through an <NUM> frequency domain. Alternatively, the <NUM> to <NUM> frequency domains/ranges may be divided into one channel through a <NUM> frequency domain.

The <NUM> band may be called in other terms such as a third band or the like. The <NUM> band may imply a frequency domain in which channels of which a center frequency is greater than or equal to <NUM> are used/supported/defined. A specific numerical value shown in <FIG> may be changed.

For example, the <NUM> channel of <FIG> may be defined starting from <NUM>. Specifically, among <NUM> channels of <FIG>, the leftmost channel may have an index <NUM> (or a channel index, a channel number, etc.), and <NUM> may be assigned as a center frequency. That is, a center frequency of a channel of an index N may be determined as (<NUM> + <NUM>*N) GHz.

Accordingly, an index (or channel number) of the <NUM> channel of <FIG> may be <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. In addition, according to the aforementioned (<NUM> + <NUM>*N)GHz rule, an index of the <NUM> channel of <FIG> may be <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

Although <NUM>, <NUM>, <NUM>, and <NUM> channels are illustrated in the example of <FIG>, a <NUM> channel or a <NUM> channel may be additionally added.

Hereinafter, a PPDU transmitted/received in a STA of the present specification will be described.

<FIG> illustrates an example of a PPDU used in the present specification.

The PPDU of <FIG> may be called in various terms such as an EHT PPDU, a TX PPDU, an RX PPDU, a first type or N-th type PPDU, or the like. For example, in the present specification, the PPDU or the EHT PPDU may be called in various terms such as a TX PPDU, a RX PPDU, a first type or N-th type PPDU, or the like. In addition, the EHT PPDU may be used in an EHT system and/or a new WLAN system enhanced from the EHT system.

The PPDU of <FIG> may indicate the entirety or part of a PPDU type used in the EHT system. For example, the example of <FIG> may be used for both of a single-user (SU) mode and a multi-user (MU) mode. In other words, the PPDU of <FIG> may be a PPDU for one receiving STA or a plurality of receiving STAs. When the PPDU of <FIG> is used for a trigger-based (TB) mode, the EHT-SIG of <FIG> may be omitted. In other words, a STA which has received a trigger frame for uplink-MU (UL-MU) may transmit the PPDU in which the EHT-SIG is omitted in the example of <FIG>.

In <FIG>, an L-STF to an EHT-LTF may be called a preamble or a physical preamble, and may be generated/transmitted/received/obtained/decoded in a physical layer.

A subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields of <FIG> may be determined as <NUM>, and a subcarrier spacing of the EHT-STF, EHT-LTF, and Data fields may be determined as <NUM>. That is, a tone index (or subcarrier index) of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields may be expressed in unit of <NUM>, and a tone index (or subcarrier index) of the EHT-STF, EHT-LTF, and Data fields may be expressed in unit of <NUM>.

In the PPDU of <FIG>, the L-LTE and the L-STF may be the same as those in the conventional fields.

The L-SIG field of <FIG> may include, for example, bit information of <NUM> bits. For example, the <NUM>-bit information may include a rate field of <NUM> bits, a reserved bit of <NUM> bit, a length field of <NUM> bits, a parity bit of <NUM> bit, and a tail bit of <NUM> bits. For example, the length field of <NUM> bits may include information related to a length or time duration of a PPDU. For example, the length field of <NUM> bits may be determined based on a type of the PPDU. For example, when the PPDU is a non-HT, HT, VHT PPDU or an EHT PPDU, a value of the length field may be determined as a multiple of <NUM>. For example, when the PPDU is an HE PPDU, the value of the length field may be determined as "a multiple of <NUM>"+<NUM> or "a multiple of <NUM>"+<NUM>. In other words, for the non-HT, HT, VHT PPDI or the EHT PPDU, the value of the length field may be determined as a multiple of <NUM>, and for the HE PPDU, the value of the length field may be determined as "a multiple of <NUM>"+<NUM> or "a multiple of <NUM>"+<NUM>.

For example, the transmitting STA may apply BCC encoding based on a <NUM>/<NUM> coding rate to the <NUM>-bit information of the L-SIG field. Thereafter, the transmitting STA may obtain a BCC coding bit of <NUM> bits. BPSK modulation may be applied to the <NUM>-bit coding bit, thereby generating <NUM> BPSK symbols. The transmitting STA may map the <NUM> BPSK symbols to positions except for a pilot subcarrier{subcarrier index -<NUM>, -<NUM>, +<NUM>, +<NUM>} and a DC subcarrier{subcarrier index <NUM>}. As a result, the <NUM> BPSK symbols may be mapped to subcarrier indices -<NUM> to -<NUM>, -<NUM> to -<NUM>, -<NUM> to -<NUM>, +<NUM> to +<NUM>, +<NUM> to +<NUM>, and +<NUM> to +<NUM>. The transmitting STA may additionally map a signal of {-<NUM>, -<NUM>, -<NUM>, <NUM>} to a subcarrier index{-<NUM>, -<NUM>, +<NUM>, +<NUM>}. The aforementioned signal may be used for channel estimation on a frequency domain corresponding to {-<NUM>, -<NUM>, +<NUM>, +<NUM>}.

The transmitting STA may generate an RL-SIG generated in the same manner as the L-SIG. BPSK modulation may be applied to the RL-SIG. The receiving STA may know that the RX PPDU is the HE PPDU or the EHT PPDU, based on the presence of the RL-SIG.

A universal SIG (U-SIG) may be inserted after the RL-SIG of <FIG>. The U-SIB may be called in various terms such as a first SIG field, a first SIG, a first type SIG, a control signal, a control signal field, a first (type) control signal, or the like.

The U-SIG may include information of N bits, and may include information for identifying a type of the EHT PPDU. For example, the U-SIG may be configured based on two symbols (e.g., two contiguous OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG may have a duration of <NUM>. Each symbol of the U-SIG may be used to transmit the <NUM>-bit information. For example, each symbol of the U-SIG may be transmitted/received based on <NUM> data tomes and <NUM> pilot tones.

Through the U-SIG (or U-SIG field), for example, A-bit information (e.g., <NUM> un-coded bits) may be transmitted. A first symbol of the U-SIG may transmit first X-bit information (e.g., <NUM> un-coded bits) of the A-bit information, and a second symbol of the U-SIB may transmit the remaining Y-bit information (e.g., <NUM> un-coded bits) of the A-bit information. For example, the transmitting STA may obtain <NUM> un-coded bits included in each U-SIG symbol. The transmitting STA may perform convolutional encoding (i.e., BCC encoding) based on a rate of R=<NUM>/<NUM> to generate <NUM>-coded bits, and may perform interleaving on the <NUM>-coded bits. The transmitting STA may perform BPSK modulation on the interleaved <NUM>-coded bits to generate <NUM> BPSK symbols to be allocated to each U-SIG symbol. One U-SIG symbol may be transmitted based on <NUM> tones (subcarriers) from a subcarrier index -<NUM> to a subcarrier index +<NUM>, except for a DC index <NUM>. The <NUM> BPSK symbols generated by the transmitting STA may be transmitted based on the remaining tones (subcarriers) except for pilot tones, i.e., tones -<NUM>, -<NUM>, +<NUM>, +<NUM>.

For example, the A-bit information (e.g., <NUM> un-coded bits) generated by the U-SIG may include a CRC field (e.g., a field having a length of <NUM> bits) and a tail field (e.g., a field having a length of <NUM> bits). The CRC field and the tail field may be transmitted through the second symbol of the U-SIG. The CRC field may be generated based on <NUM> bits allocated to the first symbol of the U-SIG and the remaining <NUM> bits except for the CRC/tail fields in the second symbol, and may be generated based on the conventional CRC calculation algorithm. In addition, the tail field may be used to terminate trellis of a convolutional decoder, and may be set to, for example, "<NUM>".

The A-bit information (e.g., <NUM> un-coded bits) transmitted by the U-SIG (or U-SIG field) may be divided into version-independent bits and version-dependent bits. For example, the version-independent bits may have a fixed or variable size. For example, the version-independent bits may be allocated only to the first symbol of the U-SIG, or the version-independent bits may be allocated to both of the first and second symbols of the U-SIG. For example, the version-independent bits and the version-dependent bits may be called in various terms such as a first control bit, a second control bit, or the like.

For example, the version-independent bits of the U-SIG may include a PHY version identifier of <NUM> bits. For example, the PHY version identifier of <NUM> bits may include information related to a PHY version of a TX/RX PPDU. For example, a first value of the PHY version identifier of <NUM> bits may indicate that the TX/RX PPDU is an EHT PPDU. In other words, when the transmitting STA transmits the EHT PPDU, the PHY version identifier of <NUM> bits may be set to a first value. In other words, the receiving STA may determine that the RX PPDU is the EHT PPDU, based on the PHY version identifier having the first value.

For example, the version-independent bits of the U-SIG may include a UL/DL flag field of <NUM> bit. A first value of the UL/DL flag field of <NUM> bit relates to UL communication, and a second value of the UL/DL flag field relates to DL communication.

For example, the version-independent bits of the U-SIG may include information related to a TXOP length and information related to a BSS color ID.

For example, when the EHT PPDU is divided into various types (e.g., various types such as an EHT PPDU related to an SU mode, an EHT PPDU related to a MU mode, an EHT PPDU related to a TB mode, an EHT PPDU related to extended range transmission, or the like), information related to the type of the EHT PPDU may be included in the version-dependent bits of the U-SIG.

For example, the U-SIG may include: <NUM>) a bandwidth field including information related to a bandwidth; <NUM>) a field including information related to an MCS scheme applied to EHT-SIG; <NUM>) an indication field including information regarding whether a dual subcarrier modulation (DCM) scheme is applied to EHT-SIG; <NUM>) a field including information related to the number of symbol used for EHT-SIG; <NUM>) a field including information regarding whether the EHT-SIG is generated across a full band; <NUM>) a field including information related to a type of EHT-LTF/STF; and <NUM>) information related to a field indicating an EHT-LTF length and a CP length.

Preamble puncturing may be applied to the PPDU of <FIG>. The preamble puncturing implies that puncturing is applied to part (e.g., a secondary <NUM> band) of the full band. For example, when an <NUM> PPDU is transmitted, a STA may apply puncturing to the secondary <NUM> band out of the <NUM> band, and may transmit a PPDU only through a primary <NUM> band and a secondary <NUM> band.

For example, a pattern of the preamble puncturing may be configured in advance. For example, when a first puncturing pattern is applied, puncturing may be applied only to the secondary <NUM> band within the <NUM> band. For example, when a second puncturing pattern is applied, puncturing may be applied to only any one of two secondary <NUM> bands included in the secondary <NUM> band within the <NUM> band. For example, when a third puncturing pattern is applied, puncturing may be applied to only the secondary <NUM> band included in the primary <NUM> band within the <NUM> band (or <NUM>+<NUM> band). For example, when a fourth puncturing is applied, puncturing may be applied to at least one <NUM> channel not belonging to a primary <NUM> band in the presence of the primary <NUM> band included in the 80MHaz band within the <NUM> band (or <NUM>+<NUM> band).

Information related to the preamble puncturing applied to the PPDU may be included in U-SIG and/or EHT-SIG. For example, a first field of the U-SIG may include information related to a contiguous bandwidth, and second field of the U-SIG may include information related to the preamble puncturing applied to the PPDU.

For example, the U-SIG and the EHT-SIG may include the information related to the preamble puncturing, based on the following method. When a bandwidth of the PPDU exceeds <NUM>, the U-SIG may be configured individually in unit of <NUM>. For example, when the bandwidth of the PPDU is <NUM>, the PPDU may include a first U-SIG for a first <NUM> band and a second U-SIG for a second <NUM> band. In this case, a first field of the first U-SIG may include information related to a <NUM> bandwidth, and a second field of the first U-SIG may include information related to a preamble puncturing (i.e., information related to a preamble puncturing pattern) applied to the first <NUM> band. In addition, a first field of the second U-SIG may include information related to a <NUM> bandwidth, and a second field of the second U-SIG may include information related to a preamble puncturing (i.e., information related to a preamble puncturing pattern) applied to the second <NUM> band. Meanwhile, an EHT-SIG contiguous to the first U-SIG may include information related to a preamble puncturing applied to the second <NUM> band (i.e., information related to a preamble puncturing pattern), and an EHT-SIG contiguous to the second U-SIG may include information related to a preamble puncturing (i.e., information related to a preamble puncturing pattern) applied to the first <NUM> band.

Additionally or alternatively, the U-SIG and the EHT-SIG may include the information related to the preamble puncturing, based on the following method. The U-SIG may include information related to a preamble puncturing (i.e., information related to a preamble puncturing pattern) for all bands. That is, the EHT-SIG may not include the information related to the preamble puncturing, and only the U-SIG may include the information related to the preamble puncturing (i.e., the information related to the preamble puncturing pattern).

The U-SIG may be configured in unit of <NUM>. For example, when an <NUM> PPDU is configured, the U-SIG may be duplicated. That is, four identical U-SIGs may be included in the <NUM> PPDU. PPDUs exceeding an <NUM> bandwidth may include different U-SIGs.

The EHT-SIG of <FIG> may include control information for the receiving STA. The EHT-SIG may be transmitted through at least one symbol, and one symbol may have a length of <NUM>. Information related to the number of symbols used for the EHT-SIG may be included in the U-SIG.

The EHT-SIG may include a technical feature of the HE-SIG-B described with reference to <FIG> and <FIG>. For example, the EHT-SIG may include a common field and a user-specific field as in the example of <FIG>. The common field of the EHT-SIG may be omitted, and the number of user-specific fields may be determined based on the number of users.

As in the example of <FIG>, the common field of the EHT-SIG and the user-specific field of the EHT-SIG may be individually coded. One user block field included in the user-specific field may include information for two users, but a last user block field included in the user-specific field may include information for one user. That is, one user block field of the EHT-SIG may include up to two user fields. As in the example of <FIG>, each user field may be related to MU-MIMO allocation, or may be related to non-MU-MIMO allocation.

As in the example of <FIG>, the common field of the EHT-SIG may include a CRC bit and a tail bit. A length of the CRC bit may be determined as <NUM> bits. A length of the tail bit may be determined as <NUM> bits, and may be set to '<NUM>'.

As in the example of <FIG>, the common field of the EHT-SIG may include RU allocation information. The RU allocation information may imply information related to a location of an RU to which a plurality of users (i.e., a plurality of receiving STAs) are allocated. The RU allocation information may be configured in unit of <NUM> bits (or N bits), as in Table <NUM>.

The example of Table <NUM> to Table <NUM> is an example of <NUM>-bit (or N-bit) information for various RU allocations. An index shown in each table may be modified, and some entries in Table <NUM> to Table <NUM> may be omitted, and entries (not shown) may be added.

The example of Table <NUM> to Table <NUM> relates to information related to a location of an RU allocated to a <NUM> band. For example, 'an index <NUM>' of Table <NUM> may be used in a situation where nine <NUM>-RUs are individually allocated (e.g., in a situation where nine <NUM>-RUs shown in <FIG> are individually allocated).

Meanwhile, a plurality or RUs may be allocated to one STA in the EHT system. For example, regarding `an index <NUM>' of Table <NUM>, one <NUM>-RU may be allocated for one user (i.e., receiving STA) to the leftmost side of the <NUM> band, one <NUM>-RU and one <NUM>-RU may be allocated to the right side thereof, and five <NUM>-RUs may be individually allocated to the right side thereof.

A mode in which the common field of the EHT-SIG is omitted may be supported. The mode in which the common field of the EHT-SIG is omitted may be called a compressed mode. When the compressed mode is used, a plurality of users (i.e., a plurality of receiving STAs) may decode the PPDU (e.g., the data field of the PPDU), based on non-OFDMA. That is, the plurality of users of the EHT PPDU may decode the PPDU (e.g., the data field of the PPDU) received through the same frequency band. Meanwhile, when a non-compressed mode is used, the plurality of users of the EHT PPDU may decode the PPDU (e.g., the data field of the PPDU), based on OFDMA. That is, the plurality of users of the EHT PPDU may receive the PPDU (e.g., the data field of the PPDU) through different frequency bands.

The EHT-SIG may be configured based on various MCS schemes. As described above, information related to an MCS scheme applied to the EHT-SIG may be included in U-SIG. The EHT-SIG may be configured based on a DCM scheme. For example, among N data tones (e.g., <NUM> data tones) allocated for the EHT-SIG, a first modulation scheme may be applied to half of contiguous tones, and a second modulation scheme may be applied to the remaining half of the contiguous tones. That is, a transmitting STA may use the first modulation scheme to modulate specific control information through a first symbol and allocate it to half of the contiguous tones, and may use the second modulation scheme to modulate the same control information by using a second symbol and allocate it to the remaining half of the contiguous tones. As described above, information (e.g., a <NUM>-bit field) regarding whether the DCM scheme is applied to the EHT-SIG may be included in the U-SIG.

An HE-STF of <FIG> may be used for improving automatic gain control estimation in a multiple input multiple output (MIMO) environment or an OFDMA environment. An HE-LTF of <FIG> may be used for estimating a channel in the MIMO environment or the OFDMA environment.

The EHT-STF of <FIG> may be set in various types. For example, a first type of STF (e.g., 1x STF) may be generated based on a first type STF sequence in which a non-zero coefficient is arranged with an interval of <NUM> subcarriers. An STF signal generated based on the first type STF sequence may have a period of <NUM>, and a periodicity signal of <NUM> may be repeated <NUM> times to become a first type STF having a length of <NUM>. For example, a second type of STF (e.g., 2x STF) may be generated based on a second type STF sequence in which a non-zero coefficient is arranged with an interval of <NUM> subcarriers. An STF signal generated based on the second type STF sequence may have a period of <NUM>, and a periodicity signal of <NUM> may be repeated <NUM> times to become a second type STF having a length of <NUM>. Hereinafter, an example of a sequence for configuring an EHT-STF (i.e., an EHT-STF sequence) is proposed. The following sequence may be modified in various ways.

The EHT-STF may be configured based on the following sequence M.

The EHT-STF for the <NUM> PPDU may be configured based on the following equation. The following example may be a first type (i.e., 1x STF) sequence. For example, the first type sequence may be included in not a trigger-based (TB) PPDU but an EHT-PPDU. In the following equation, (a:b:c) may imply a duration defined as b tone intervals (i.e., a subcarrier interval) from a tone index (i.e., subcarrier index) 'a' to a tone index 'c'. For example, the equation <NUM> below may represent a sequence defined as <NUM> tone intervals from a tone index -<NUM> to a tone index <NUM>. Since a subcarrier spacing of <NUM> is applied to the EHT-STR, the <NUM> tone intervals may imply that an EHT-STF coefficient (or element) is arranged with an interval of <NUM> * <NUM> = <NUM>. In addition, * implies multiplication, and sqrt() implies a square root. In addition, j implies an imaginary number.

The EHT-STF for the <NUM> PPDU may be configured based on the following equation. The following example may be the first type (i.e., 1x STF) sequence.

In the EHT-STF for the <NUM>+<NUM> PPDU, a sequence for lower <NUM> may be identical to Equation <NUM>. In the EHT-STF for the <NUM>+<NUM> PPDU, a sequence for upper <NUM> may be configured based on the following equation.

Equation <NUM> to Equation <NUM> below relate to an example of a second type (i.e., 2x STF) sequence.

The EHT-STF for the <NUM> PPDU may be configured based on the following equation.

The EHT-LTF may have first, second, and third types (i.e., 1x, 2x, 4x LTF). For example, the first/second/third type LTF may be generated based on an LTF sequence in which a non-zero coefficient is arranged with an interval of <NUM>/<NUM>/<NUM> subcarriers. The first/second/third type LTF may have a time length of <NUM>/<NUM>/<NUM>. In addition, a GI (e.g., <NUM>/<NUM>/<NUM>/<NUM>) having various lengths may be applied to the first/second/third type LTF.

Information related to a type of STF and/or LTF (information related to a GI applied to LTF is also included) may be included in a SIG-A field and/or SIG-B field or the like of <FIG>.

A PPDU (e.g., EHT-PPDU) of <FIG> may be configured based on the example of <FIG> and <FIG>.

For example, an EHT PPDU transmitted on a <NUM> band, i.e., a <NUM> EHT PPDU, may be configured based on the RU of <FIG>. That is, a location of an RU of EHT-STF, EHT-LTF, and data fields included in the EHT PPDU may be determined as shown in <FIG>.

An EHT PPDU transmitted on a <NUM> band, i.e., a <NUM> EHT PPDU, may be configured based on the RU of <FIG>. That is, a location of an RU of EHT-STF, EHT-LTF, and data fields included in the EHT PPDU may be determined as shown in <FIG>.

Since the RU location of <FIG> corresponds to <NUM>, a tone-plan for <NUM> may be determined when the pattern of <FIG> is repeated twice. That is, an <NUM> EHT PPDU may be transmitted based on a new tone-plan in which not the RU of <FIG> but the RU of <FIG> is repeated twice.

When the pattern of <FIG> is repeated twice, <NUM> tones (i.e., <NUM> guard tones + <NUM> guard tones) may be configured in a DC region. That is, a tone-plan for an <NUM> EHT PPDU allocated based on OFDMA may have <NUM> DC tones. Unlike this, an <NUM> EHT PPDU allocated based on non-OFDMA (i.e., a non-OFDMA full bandwidth <NUM> PPDU) may be configured based on a <NUM>-RU, and may include <NUM> DC tones, <NUM> left guard tones, and <NUM> right guard tones.

A tone-plan for <NUM>/<NUM>/<NUM> may be configured in such a manner that the pattern of <FIG> is repeated several times.

The PPDU of <FIG> may be determined (or identified) as an EHT PPDU based on the following method.

A receiving STA may determine a type of an RX PPDU as the EHT PPDU, based on the following aspect. For example, the RX PPDU may be determined as the EHT PPDU: <NUM>) when a first symbol after an L-LTF signal of the RX PPDU is a BPSK symbol; <NUM>) when RL-SIG in which the L-SIG of the RX PPDU is repeated is detected; and <NUM>) when a result of applying "modulo <NUM>" to a value of a length field of the L-SIG of the RX PPDU is detected as "<NUM>". When the RX PPDU is determined as the EHT PPDU, the receiving STA may detect a type of the EHT PPDU (e.g., an SU/MU/Trigger-based/Extended Range type), based on bit information included in a symbol after the RL-SIG of <FIG>. In other words, the receiving STA may determine the RX PPDU as the EHT PPDU, based on: <NUM>) a first symbol after an L-LTF signal, which is a BPSK symbol; <NUM>) RL-SIG contiguous to the L-SIG field and identical to L-SIG; <NUM>) L-SIG including a length field in which a result of applying "modulo <NUM>" is set to "<NUM>"; and <NUM>) a <NUM>-bit PHY version identifier of the aforementioned U-SIG (e.g., a PHY version identifier having a first value).

For example, the receiving STA may determine the type of the RX PPDU as the EHT PPDU, based on the following aspect. For example, the RX PPDU may be determined as the HE PPDU: <NUM>) when a first symbol after an L-LTF signal is a BPSK symbol; <NUM>) when RL-SIG in which the L-SIG is repeated is detected; and <NUM>) when a result of applying "modulo <NUM>" to a value of a length field of the L-SIG is detected as "<NUM>" or "<NUM>".

For example, the receiving STA may determine the type of the RX PPDU as a non-HT, HT, and VHT PPDU, based on the following aspect. For example, the RX PPDU may be determined as the non-HT, HT, and VHT PPDU: <NUM>) when a first symbol after an L-LTF signal is a BPSK symbol; and <NUM>) when RL-SIG in which L-SIG is repeated is not detected. In addition, even if the receiving STA detects that the RL-SIG is repeated, when a result of applying "modulo <NUM>" to the length value of the L-SIG is detected as "<NUM>", the RX PPDU may be determined as the non-HT, HT, and VHT PPDU.

In the following example, a signal represented as a (TX/RX/UL/DL) signal, a (TX/RX/UL/DL) frame, a (TX/RX/UL/DL) packet, a (TX/RX/UL/DL) data unit, (TX/RX/UL/DL) data, or the like may be a signal transmitted/received based on the PPDU of <FIG>. The PPDU of <FIG> may be used to transmit/receive frames of various types. For example, the PPDU of <FIG> may be used for a control frame. An example of the control frame may include a request to send (RTS), a clear to send (CTS), a power save-poll (PS-poll), BlockACKReq, BlockAck, a null data packet (NDP) announcement, and a trigger frame. For example, the PPDU of <FIG> may be used for a management frame. An example of the management frame may include a beacon frame, a (re-)association request frame, a (re-)association response frame, a probe request frame, and a probe response frame. For example, the PPDU of <FIG> may be used for a data frame. For example, the PPDU of <FIG> may be used to simultaneously transmit at least two or more of the control frame, the management frame, and the data frame.

<FIG> illustrates an example of a modified transmission device and/or receiving device of the present specification.

Each device/STA of the sub-figure (a)/(b) of <FIG> may be modified as shown in <FIG>. A transceiver <NUM> of <FIG> may be identical to the transceivers <NUM> and <NUM> of <FIG>. The transceiver <NUM> of <FIG> may include a receiver and a transmitter.

A processor <NUM> of <FIG> may be identical to the processors <NUM> and <NUM> of <FIG>. Alternatively, the processor <NUM> of <FIG> may be identical to the processing chips <NUM> and <NUM> of <FIG>.

A memory <NUM> of <FIG> may be identical to the memories <NUM> and <NUM> of <FIG>. Alternatively, the memory <NUM> of <FIG> may be a separate external memory different from the memories <NUM> and <NUM> of <FIG>.

Referring to <FIG>, a power management module <NUM> manages power for the processor <NUM> and/or the transceiver <NUM>. A battery <NUM> supplies power to the power management module <NUM>. A display <NUM> outputs a result processed by the processor <NUM>. A keypad <NUM> receives inputs to be used by the processor <NUM>. The keypad <NUM> may be displayed on the display <NUM>. A SIM card <NUM> may be an integrated circuit which is used to securely store an international mobile subscriber identity (IMSI) and its related key, which are used to identify and authenticate subscribers on mobile telephony devices such as mobile phones and computers.

Referring to <FIG>, a speaker <NUM> may output a result related to a sound processed by the processor <NUM>. A microphone <NUM> may receive an input related to a sound to be used by the processor <NUM>.

Hereinafter, technical features of channel bonding supported by the STA of the present disclosure will be described.

For example, in an IEEE <NUM>. 11n system, <NUM> channel bonding may be performed by combining two <NUM> channels. In addition, <NUM>/<NUM>/<NUM> channel bonding may be performed in the IEEE <NUM>. 11ac system.

For example, the STA may perform channel bonding for a primary <NUM> channel (P20 channel) and a secondary <NUM> channel (S20 channel). A backoff count/counter may be used in the channel bonding process. The backoff count value may be chosen as a random value and decremented during the backoff interval. In general, when the backoff count value becomes <NUM>, the STA may attempt to access the channel.

During the backoff interval, when the P20 channel is determined to be in the idle state and the backoff count value for the P20 channel becomes <NUM>, the STA, performing channel bonding, determines whether an S20 channel has maintained an idle state for a certain period of time (for example, point coordination function interframe space (PIFS)). If the S20 channel is in an idle state, the STA may perform bonding on the P20 channel and the S20 channel. That is, the STA may transmit a signal (PPDU) through a <NUM> channel (that is, a <NUM> bonding channel) including a P20 channel and the S20 channel.

<FIG> shows an example of channel bonding. As shown in <FIG>, the primary <NUM> channel and the secondary <NUM> channel may make up a <NUM> channel (primary <NUM> channel) through channel bonding. That is, the bonded <NUM> channel may include a primary <NUM> channel and a secondary <NUM> channel.

Channel bonding may be performed when a channel contiguous to the primary channel is in an idle state. That is, the Primary <NUM> channel, the Secondary <NUM> channel, the Secondary <NUM> channel, and the Secondary <NUM> channel can be sequentially bonded. However, if the secondary <NUM> channel is determined to be in the busy state, channel bonding may not be performed even if all other secondary channels are in the idle state. In addition, when it is determined that the secondary <NUM> channel is in the idle state and the secondary <NUM> channel is in the busy state, channel bonding may be performed only on the primary <NUM> channel and the secondary <NUM> channel.

Hereinafter, preamble puncturing supported by an STA in the present disclosure will be described.

For example, in the example of <FIG>, if the Primary <NUM> channel, the Secondary <NUM> channel, and the Secondary <NUM> channel are all in the idle state, but the Secondary <NUM> channel is in the busy state, bonding to the secondary <NUM> channel and the secondary <NUM> channel may not be possible. In this case, the STA may configure a <NUM> PPDU and may perform a preamble puncturing on the preamble transmitted through the secondary <NUM> channel (for example, L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF, EHT-SIG, EHT -STF, EHT-LTF, etc.), so that the STA may transmit a signal through a channel in the idle state. In other words, the STA may perform preamble puncturing for some bands of the PPDU. Information on preamble puncturing (for example, information about <NUM>/<NUM>/<NUM> channels/bands to which puncturing is applied) may be included in a signal field (for example, HE-SIG-A, U-SIG, EHT-SIG) of the PPDU.

Hereinafter, technical features of a multi-link (ML) supported by an STA of the present disclosure will be described.

The STA (AP and/or non-AP STA) of the present disclosure may support multi-link (ML) communication. ML communication may refer to communication supporting a plurality of links. The link related to ML communication may include channels of the <NUM> band shown in <FIG>, the <NUM> band shown in <FIG>, and the <NUM> band shown in <FIG> (for example, <NUM>/<NUM>/<NUM>/<NUM>/<NUM>/<NUM> channels).

A plurality of links used for ML communication may be set in various ways. For example, a plurality of links supported by one STA for ML communication may be a plurality of channels in a <NUM> band, a plurality of channels in a <NUM> band, and a plurality of channels in a <NUM> band. Alternatively, a plurality of links supported by one STA for ML communication may be a combination of at least one channel in the <NUM> band (or <NUM>/<NUM> band) and at least one channel in the <NUM> band (or <NUM>/<NUM> band). Meanwhile, at least one of the plurality of links supported by one STA for ML communication may be a channel to which preamble puncturing is applied.

The STA may perform an ML setup to perform ML communication. The ML setup may be performed based on a management frame or control frame such as a Beacon, a Probe Request/Response, an Association Request/Response, and the like. For example, information about ML setup may be included in an element field included in a Beacon, a Probe Request/Response, an Association Request/Response, and the like.

When ML setup is completed, an enabled link for ML communication may be determined. The STA may perform frame exchange through at least one of a plurality of links determined as an enabled link. For example, the enabled link may be used for at least one of a management frame, a control frame, and a data frame.

When one STA supports multiple links, a transceiver supporting each link may operate as one logical STA. For example, one STA supporting two links may be expressed as one Multi Link Device (MLD) including a first STA for the first link and a second STA for the second link. For example, one AP supporting two links may be expressed as one AP MLD including a first AP for a first link and a second AP for a second link. In addition, one non-AP supporting two links may be expressed as one non-AP MLD including a first STA for the first link and a second STA for the second link.

Hereinafter, more specific features related to the ML setup are described.

The MLD (AP MLD and/or non-AP MLD) may transmit, through ML setup, information on a link that the corresponding MLD can support. Link information may be configured in various ways. For example, information on the link may include at least one of <NUM>) information on whether the MLD (or STA) supports simultaneous RX/TX operation, <NUM>) information on the number/upper limit of uplink/downlink links supported by the MLD (or STA), <NUM>) information on the location/band/resource of the uplink/downlink Link supported by the MLD (or STA), <NUM>) information on the frame type (management, control, data, etc.) available or preferred in at least one uplink/downlink link, <NUM>) information on ACK policy available or preferred in at least one uplink/downlink link, and <NUM>) information on an available or preferred traffic identifier (TID) in at least one uplink/downlink Link. The TID is related to the priority of traffic data and is expressed as eight types of values according to the conventional wireless LAN standard. That is, eight TID values corresponding to four access categories (ACs) (AC_Background (AC_BK), AC_Best Effort (AC_BE), AC_Video (AC_VI), AC_Voice (AC_VO)) according to the conventional WLAN standard may be defined.

For example, it may be preset that all TIDs are mapped for uplink/downlink link. Specifically, if negotiation is not made through ML setup, if all TIDs are used for ML communication, and if the mapping between uplink/downlink link and TID is negotiated through additional ML settings, the negotiated TID may be used for ML communication.

Through ML setup, a plurality of links usable by the transmitting MLD and the receiving MLD related to ML communication may be set, and this may be referred to as an "enabled link". The "enabled link" may be called differently in various expressions. For example, it may be referred to as various expressions such as a first link, a second link, a transmission link, and a reception link.

After the ML setup is completed, the MLD could update the ML setup. For example, the MLD may transmit information on a new link when it is necessary to update information on the link. Information on the new link may be transmitted based on at least one of a management frame, a control frame, and a data frame.

In extreme high throughput (EHT), a standard being discussed after IEEE802.11ax, the introduction of HARQ is being considered. When HARQ is introduced, coverage can be expanded in a low signal to noise ratio (SNR) environment, that is, in an environment where the distance between the transmitting terminal and the receiving terminal is long, and higher throughput may be obtained in a high SNR environment.

The device described below may be the apparatus of <FIG> and/or <NUM>, and the PPDU described below may be the PPDU of <FIG>. The device may be an AP or a non-AP STA. The device described below may be an AP multi-link device (MLD) supporting multi-link or a non-AP STA MLD.

In extremely high throughput (EHT), a standard being discussed after <NUM>. 11ax, a multi-link environment using one or more bands at the same time is being considered. When the device supports multi-link or multi-link, the device may use one or more bands (e.g., <NUM>, <NUM>, <NUM>, <NUM>, etc.) simultaneously or alternately. Multi-link transmission can be classified into two types as shown in <FIG>.

Hereinafter, although described in the form of a multi-link, the frequency band may be configured in various other forms. Although terms such as multi-band and/or multi-link may be used in this specification, the following embodiments may be described based on multi-link for convenience of description below.

In the following specification, MLD refers to a multi-link device. The MLD has one or more affiliated STAs and has one MAC service access point (SAP) that connects to an upper link layer (Logical Link Control, LLC). The MLD may mean a physical device or a logical device. Hereinafter, a device may mean the MLD.

In the following specification, a transmitting device and a receiving device may refer to the MLD. The first link of the receiving/transmitting device may be a terminal (e.g., STA or AP) that performs signal transmission/reception through the first link included in the receiving/transmitting device. The second link of the receiving/transmitting device may be a terminal (e.g., STA or AP) that performs signal transmission/reception through the second link included in the receiving/transmitting device.

IEEE802.11be can support two types of multi-link operations. For example, simultaneous transmit and receive (STR) and non-STR operations may be considered. For example, an STR may be referred to as an asynchronous multi-link operation, and a non-STR may be referred to as a synchronous multi-link operation. The multi-link may include a multi-band. That is, the multi-link may mean a link included in several frequency bands, or may mean a plurality of links included in one frequency band.

<FIG> is a diagram illustrating an embodiment of a device supporting multi-link.

Referring to <FIG>, a multi-link device may have three links, and each link may include a primary channel (PCH). For example, `link <NUM>' supporting the <NUM> band and `link <NUM>' and `link <NUM>' supporting the <NUM> band may be provided. A multi-link device (STA) may include a plurality of STAs. For example, the multi-link device may include `STA <NUM>', `STA <NUM>', and `STA <NUM>', the STA <NUM> may operate on the link <NUM>, the STA <NUM> may operate on the link <NUM>, and the STA <NUM> may operate on the link <NUM>.

In the case of non-STR (i.e., synchronous multi-link operation), a back-off operation may be performed in the primary channel of each link. Due to the randomness of the backoff operation, it is rare that all links have a backoff counter value of <NUM> at the same time, and thus, aggregation of several links may occur rarely. That is, the case in which link aggregation in which PPDUs can be transmitted simultaneously on multiple links can occur naturally may occur very rarely. Therefore, there is a need for a method capable of efficiently performing aggregation, and an aggregation transmission method based on deferring will be described below.

The PCH of each link of the multi-link STA (i.e., multi-link device, MLD) basically decrements the back-off counter (BC) based on EDCA. For example, the multi-link device may independently perform EDCA-based channel access for each link, and may decrement a backoff counter for each link.

When a BC of one link reaches <NUM>, a BC of another link is less likely to be <NUM>, so the following operation may be necessary.

If the multi-link device (STA) uses all the links enabled, this process does not necessarily have to be performed.

There may be a primary link that should always be included, such as a link performing the main BSS functionality.

<FIG> is a diagram illustrating an embodiment of a channel access method.

Referring to <FIG>, on the assumption that links <NUM>, <NUM>, and <NUM> are all selected, if a BC of the link <NUM> reaches <NUM>, the multi-link device defers in the link <NUM> until BCs of the links <NUM> and <NUM> reach <NUM>, and even if a BC of the link <NUM> reaches <NUM>, the link <NUM> may defer until a BC of the link <NUM> reaches <NUM> because a BC of the link <NUM> has not reached <NUM> yet.

First, during deferring in the link where BC is <NUM>, the method can be classified as follows according to the channel state and the action according to the state.

This method may be difficult to aggregate because it has a large dependency on each channel state.

Referring to <FIG>, when BC = <NUM> of the STA <NUM> in the link <NUM>, if the channel is IDLE, the BC is continuously kept at <NUM>, and when the channel is BUSY, a back-off procedure can be started again. Even in the link <NUM>, when a BC of the STA <NUM> reaches <NUM>, if the channel is IDLE, the STA <NUM> may continuously hold/keep the BC at <NUM>. In the link <NUM>, because the channel is BUSY, the STA <NUM> starts a back-off procedure again, and since there is a point in time when the BCs of the STA <NUM> and the STA <NUM> are <NUM> at the same time, a back-off procedure may be performed for the link <NUM>, and the device may transmit frame(s) by aggregating only the link <NUM> and the link <NUM>.

This method is relatively easy to aggregate, as it holds/keeps a BC at zero when the BC reaches zero, as described in step "<NUM>)" above. In addition, when deferring on one link for a long time, collision may occur with other STAs that are equally deferring on the corresponding link.

Referring to <FIG> , when a BC of the STA <NUM> in the link <NUM> reaches <NUM>, the BC can be continuously held/kept at <NUM> regardless of channel state, and STA <NUM> continuously hold/keep a BC at <NUM> in the link <NUM> regardless of channel state. If a BC reaches <NUM> in the link <NUM> and channels are IDLE in all links, the STA <NUM>, the STA <NUM>, and the STA <NUM> may transmit data (i.e., PPDU) at the same time. Link aggregation transmission is not limited to when there are three links, and can be applied to all of the cases in which there are two or more links.

That is, if the channel is BUSY, a back-off procedure can be restarted or deferred. The Method <NUM> and Method <NUM> can be freely used depending on the situation.

Referring to <FIG>, in the link <NUM>, when BC = <NUM> of the STA <NUM>, the BC may be continuously held/kept at <NUM> regardless of the channel state. In the link <NUM>, if the channel is BUSY, the STA <NUM> may start a back-off procedure again. In link <NUM>, because the channel is BUSY, the STA <NUM> starts a back-off procedure again, and since there is a point in time when BCs of STA <NUM> and STA <NUM> reach <NUM> at the same time, the STA <NUM> of the link <NUM> performs a back-off procedure, and a PPDU transmission can be performed only in the link <NUM> and link <NUM> after aggregation.

<FIG> is a diagram illustrating an embodiment of an operation of a transmitting device.

Referring to <FIG>, the operation of the transmitting device may be performed based on <FIG>.

For example, the transmitting device may include a first STA and a second STA. The first STA may operate for/on the first link, and the second STA may operate for/on the second link.

For a non-STR (i.e., synchronous multi-link operation) device, a back-off operation may be performed in the primary channel of each link.

With respect to PCH of each link of the multi-link STA (i.e., multi-link device, MLD), the MLD decrements a back-off counter (BC) based on EDCA. For example, the multi-link device may independently perform EDCA-based channel access for each link, and may decrement a backoff counter for each link.

A transmitting device performs channel access (S2610). The transmitting device performs channel access on the first and second links.

The transmitting device determines whether to transmit the PPDU through the first link (S2620). The transmitting device determines whether to transmit a first physical protocol data unit (PPDU) based on a channel access result on the first link and a channel access result on the second link.

If a BC of one link reaches zero, the BC of the link is kept/held at zero until all links have BCs equal to zero. That is, an STA including a link in which a BC reaches <NUM> first waits without transmitting a PPDU until a BC in another link in the same transmitting device reaches <NUM>.

Based on a back-off counter of the first link reaching zero (<NUM>) and a back-off counter of the second link not reaching zero (<NUM>), the first PPDU is not transmitted and the back-off counter of the first link is kept/held at zero (<NUM>).

Based on a back-off counter of the first link reaching zero (<NUM>) and a back-off counter of the second link reaching zero (<NUM>), the first PPDU is transmitted.

Optionally, based on both back-off counters of the first link and the second link reaching zero (<NUM>) and both channels of the first link and the second link being idle, the first PPDU may be transmitted.

For example, when a channel of the first link is occupied by another device while the back-off counter of the first link is kept at zero (<NUM>), new channel access is performed on the first link.

The transmitting device transmits the first PPDU through the first link (S2630). For example, a second PPDU may be transmitted through the second link at the same time as transmitting the first PPDU. That is, the first link/STA for transmitting the first PPDU and the second link/STA for transmitting the second PPDU may simultaneously transmit the PPDU through the aggregation.

<FIG> is a diagram illustrating an embodiment of an operation of a receiving device.

For example, the receiving device may include a first STA and a second STA. The first STA may operate for/on the first link, and the second STA may operate for/on the second link.

Referring to <FIG> , the receiving device may receive the first PPDU and the second PPDU through the first link and the second link (S2710). The first PPDU and the second PPDU may be PPDUs simultaneously transmitted through link aggregation.

The receiving device may decode the first PPDU and the second PPDU (S2720).

Some of the detailed steps shown in the example of <FIG> and <FIG> may not be essential steps and may be omitted. In addition to the steps shown in <FIG> and <FIG>, other steps may be added, and the order of the steps may vary. Some of the above steps may have independent technical meaning.

The technical features of the present specification described above may be applied to various devices and methods. For example, the above-described technical features of the present specification may be performed/supported through the apparatus of <FIG> and/or <NUM>. For example, the above-described technical features of the present specification may be applied only to a part of <FIG> and/or <NUM>. For example, the technical features of the present specification described above are implemented based on the processing chip(s) <NUM> and/or <NUM> of <FIG>, or implemented based on the processor(s) <NUM> and/or <NUM> and the memory(s) <NUM> and/or <NUM> of <FIG>, or may be implemented based on the processor <NUM> and the memory <NUM> of <FIG>. For example, an apparatus herein may include a memory and a processor operatively coupled to the memory, the processor to perform channel access in first and second links; determine whether to transmit a first physical protocol data unit (PPDU) based on a channel access result in the first link and a channel access result in the second link; and transmit the first PPDU through the first link.

The technical features of the present specification may be implemented based on a computer readable medium (CRM). For example, the CRM proposed by the present specification includes at least an instruction based on being executed by at least one processor of a station (STA) of a wireless local area network (Wireless Local Area Network) system. The CRM stores instructions that perform operations comprising: performing channel access on a first link and a second link; determining whether to transmit a first physical protocol data unit (PPDU) based on a channel access result on the first link and a channel access result on the second link; and transmitting the first PPDU through the first link.

The instructions stored in the CRM of the present specification may be executed by at least one processor. At least one processor related to CRM in the present specification may be the processor(s) <NUM> and/or <NUM> or the processing chip(s) <NUM> and/or <NUM> of <FIG>, or the processor <NUM> of <FIG>. Meanwhile, the CRM of the present specification may be the memory(s) <NUM> and/or <NUM> of <FIG>, the memory <NUM> of <FIG>, or a separate external memory/storage medium/disk.

The foregoing technical features of this specification are applicable to various applications.

For example, the foregoing technical features may be applied for wireless communication of a device supporting artificial intelligence (AI).

Artificial intelligence refers to a field of study on artificial intelligence or methodologies for creating artificial intelligence, and machine learning refers to a field of study on methodologies for defining and solving various issues in the area of artificial intelligence. Machine learning is also defined as an algorithm for improving the performance of an operation through steady experiences of the operation.

An artificial neural network (ANN) is a model used in machine learning and may refer to an overall problem-solving model that includes artificial neurons (nodes) forming a network by combining synapses. The artificial neural network may be defined by a pattern of connection between neurons of different layers, a learning process of updating a model parameter, and an activation function generating an output value.

The artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer includes one or more neurons, and the artificial neural network may include synapses that connect neurons. In the artificial neural network, each neuron may output a function value of an activation function of input signals input through a synapse, weights, and deviations.

A model parameter refers to a parameter determined through learning and includes a weight of synapse connection and a deviation of a neuron. A hyper-parameter refers to a parameter to be set before learning in a machine learning algorithm and includes a learning rate, the number of iterations, a mini-batch size, and an initialization function.

Learning an artificial neural network may be intended to determine a model parameter for minimizing a loss function. The loss function may be used as an index for determining an optimal model parameter in a process of learning the artificial neural network.

Machine learning may be classified into supervised learning, unsupervised learning, and reinforcement learning.

Supervised learning refers to a method of training an artificial neural network with a label given for training data, wherein the label may indicate a correct answer (or result value) that the artificial neural network needs to infer when the training data is input to the artificial neural network. Unsupervised learning may refer to a method of training an artificial neural network without a label given for training data. Reinforcement learning may refer to a training method for training an agent defined in an environment to choose an action or a sequence of actions to maximize a cumulative reward in each state.

Machine learning implemented with a deep neural network (DNN) including a plurality of hidden layers among artificial neural networks is referred to as deep learning, and deep learning is part of machine learning. Hereinafter, machine learning is construed as including deep learning.

The foregoing technical features may be applied to wireless communication of a robot.

Robots may refer to machinery that automatically process or operate a given task with own ability thereof. In particular, a robot having a function of recognizing an environment and autonomously making a judgment to perform an operation may be referred to as an intelligent robot.

Robots may be classified into industrial, medical, household, military robots and the like according uses or fields. A robot may include an actuator or a driver including a motor to perform various physical operations, such as moving a robot joint. In addition, a movable robot may include a wheel, a brake, a propeller, and the like in a driver to run on the ground or fly in the air through the driver.

The foregoing technical features may be applied to a device supporting extended reality.

Extended reality collectively refers to virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology is a computer graphic technology of providing a real-world object and background only in a CG image, AR technology is a computer graphic technology of providing a virtual CG image on a real object image, and MR technology is a computer graphic technology of providing virtual objects mixed and combined with the real world.

MR technology is similar to AR technology in that a real object and a virtual object are displayed together. However, a virtual object is used as a supplement to a real object in AR technology, whereas a virtual object and a real object are used as equal statuses in MR technology.

Claim 1:
A method in a wireless local area network, WLAN, system, the method comprising:
performing (S2610), by a non-simultaneous transmit and receive, non-STR, device, channel access on a first link and a second link; and
determining (S2620), by the non-STR device, whether to transmit a first physical protocol data unit, PPDU, based on a channel access result on the first link and a channel access result on the second link,
wherein based on a back-off counter of the first link reaching zero and a back-off counter of the second link not reaching zero,
the non-STR device determines not to transmit the first PPDU through the first link and keeps the back-off counter of the first link at zero, and
wherein based on a back-off counter of the first link reaching zero and a back-off counter of the second link reaching zero,
the non-STR device determines to transmit the first PPDU through the first link.