Wireless communication method using multilink, and wireless communication terminal using same

Abstract

To provide a method for a station (STA) to transmit a frame in a wireless communication system.SOLUTION: In the present invention, a STA receives a management frame including a first operation element and a second operation element from an access point (AP), and transmits a PPDU to the AP on the basis of the first operation element or the second operation element. Here, the first operation element may indicate a basic service set (BSS) operating channel for a legacy STA, and the second operation element may indicate a BSS operating channel for the STA that is not the legacy STA.SELECTED DRAWING: Figure 39

Description

[Technical field]

[0001] The present invention relates to a wireless communication method using multilinks and a wireless communication terminal using the same. [Background technology]

[0002] Recently, as the use of mobile devices has become more widespread, wireless LAN technology that can provide them with high-speed wireless Internet services has been attracting attention. Wireless LAN technology is a technology that enables mobile devices such as smartphones, smart pads, laptop PCs, portable multimedia players, embedded devices, etc. to wirelessly connect to the Internet at home, in business, or in specific service areas based on short-distance wireless communication technology.

[0003] Since IEEE (Institute of Electronics Engineers) 802.11 supported early wireless LAN technology using 2.4GHz frequency, it has put into practical use or is currently developing standards for various technologies. First, IEEE 802.11b uses the 2.4GHz frequency band and supports a maximum communication speed of 11Mbps. IEEE 802.11a, which was commercialized after IEEE 802.11b, uses the 5GHz frequency band instead of the 2.4GHz band, reducing the impact of interference compared to the significantly more congested 2.4GHz frequency band, and uses OFDM technology to increase communication speeds to a maximum of 54Mbps. However, IEEE 802.11a has the disadvantage of a shorter communication distance than IEEE 802.11b. IEEE 802.11g, like IEEE 802.11b, uses the 2.4GHz band and achieves a maximum transmission speed of 54Mbps, and has attracted considerable attention because it satisfies backward compatibility, but it also has an advantage over IEEE 802.11a in communication distance.

[0004] IEEE 802.11n is a technical standard established to overcome the communication speed limitations that have been pointed out as a weakness of wireless LAN. The purpose of IEEE 802.11n is to increase the speed and reliability of the network and to extend the operating distance of wireless networks. In detail, IEEE 802.11n supports high throughput (HT) with a data processing speed of up to 540Mbps or more, and is based on MIMO (Multiple Inputs and Multiple Outputs) technology that uses multiple antennas on both the transmitting and receiving ends to minimize transmission errors and optimize data speed. This standard also uses a coding method that transmits multiple duplicate copies to increase data reliability.

[0005] As the use of wireless LANs becomes more widespread and applications using them become more diverse, the need for new wireless LAN systems to support data throughput rates (Very High Throughput, VHT) higher than those supported by IEEE 802.11n is emerging. Among them, IEEE 802.11ac supports wide bandwidth (80MHz~160MHz) at 5GHz frequency. Although the IEEE 802.11ac standard is defined only in the 5GHz band, it is expected that initial 11ac chipsets will also support operation in the 2.4GHz band for backward compatibility with existing 2.4GHz band products. Theoretically, this standard allows multi-station wireless LAN speeds of at least 1Gbps and maximum single link speeds of at least 500Mbps. This is done by extending the air interface concepts accepted by 802.11n, such as wider radio frequency bandwidth (up to 160MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high density modulation (up to 256QAM). Also, there is IEEE 802.11ad, a method of transmitting data using the 60GHz band instead of the conventional 24GHz / 5GHz. IEEE 802.11ad is a transmission standard that uses beamforming technology to provide speeds of up to 7Gbps, and is suitable for streaming large amounts of data and high bitrate videos such as uncompressed HD video. However, the 60GHz frequency band has the disadvantage that it is difficult to pass through obstacles and can only be used between devices in close proximity.

[0006] Meanwhile, the IEEE 802.11ax (High Efficiency WLAN, HEW) standard is being developed and is in the final stages as the WLAN standard after 802.11ac and 802.11ad to provide high-efficiency and high-performance WLAN communication technology in high-density environments where APs and terminals are densely packed. In an 802.11ax-based WLAN environment, it is necessary to provide high-frequency efficient communication indoors / outdoors in the presence of high density stations and APs (Access Points), and various technologies are being developed to realize this.

[0007] In addition, new WLAN standards have begun to be developed to increase maximum transmission speeds to support new multimedia applications such as high-definition video and real-time games. IEEE 802.11be (Extremely High Throughput, EHT), the 7th generation WLAN standard, is currently being developed with the goal of supporting a maximum transmission rate of 30Gbps through wider bandwidth in the 2.4 / 5 / 6GHz band, increased spatial streams, and multi-AP cooperation. IEEE 802.11be proposes technologies such as a 320MHz bandwidth, multi-link operation, multi-AP (Multi-Access Point, Multi-AP) operation, and hybrid automatic repeat request (HARQ) retransmission operation.

[0008] The multi-link operation operates in various forms depending on the operation method and implementation method. In this case, problems that did not occur in the conventional IEEE 802.11-based WLAN communication operation may occur, so it is necessary to define the detailed operation method of the multi-link operation.

[0009] On the other hand, the art that constitutes the background of the invention is created to enhance understanding of the background of the invention and includes content that is not prior art already known to those with ordinary skill in the field to which this technology belongs. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has an object to provide a method for setting up a BSS (Basic Service Set) operating channel in a multi-link operation.

[0011] Another object of the present invention is to provide a method for setting up a channel operating another BSS to a legacy terminal.

[0012] Another object of the present invention is to provide a method for indicating unavailable sub-channels included in a BSS operating channel.

[0013] Another object of the present invention is to provide a method for determining a size of response information for each terminal when transmitting a response frame to terminals including a legacy terminal.

[0014] The technical problem to be achieved in the specification is not limited to the technical problem mentioned above, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the art to which the present invention pertains from the following description. [Means for solving the problem]

[0015] A station (STA) of a wireless communication system includes a transceiver and a processor that controls the transceiver, and the processor receives a management frame including a first operation element and a second operation element from an AP (Access Point), where the first operation element indicates a BSS operation channel for a legacy STA and the second operation element indicates a BSS operation channel for the STA that is not the legacy STA, and transmits a PPDU to the AP based on the first operation element or the second operation element, but if the BSS operation channel for the STA includes at least one unavailable channel and / or exceeds a maximum bandwidth supported by the legacy STA, the BSS operation channel for the legacy STA indicated by the first operation element is different from the BSS operation channel for the STA indicated by the second operation element.

[0016] Also, in the present invention, when the BSS operating channel for the STA includes the at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is a consecutive channel including a primary channel within the BSS operating channel for the STA indicated by the second operating element.

[0017] Also, in the present invention, when the BSS operating channel for the STA includes the at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is set within the maximum bandwidth, excluding the at least one unavailable channel within the BSS operating channel for the STA indicated by the second operating element.

[0018] In addition, in the present invention, the first operating element is an operating element for a High Efficiency (HE) STA, and the second operating element is an operating element for an Extremely High Throughput (EHT) STA.

[0019] In addition, in the present invention, the second operating element includes a Disabled Subchannel Bitmap Present subfield indicating whether or not a Disabled Subchannel Bitmap subfield indicating at least one unavailable channel of the BSS operating channel for the STA is included.

[0020] Also in the present invention, each bit of the Deactivated Subchannel Bitmap subfield indicates whether a corresponding unavailable channel is included in the BSS serving channels for the STA.

[0021] Also, in the present invention, if the BSS operating channel for the STA does not include at least one unavailable channel, the value of the deactivated subchannel bitmap present subfield is set to '0', which is a value indicating that the deactivated subchannel bitmap subfield is not included.

[0022] In addition, in the present invention, the processor receives a frame including a specific field indicating whether an operational parameter is changed from the AP, and the value of the specific field is increased if the operational parameter is changed.

[0023] In addition, in the present invention, the value of the specific field is increased when the inclusion / non-inclusion of the deactivated subchannel bitmap subfield is changed or when the inclusion / non-inclusion of the at least one unavailable channel is changed.

[0024] In addition, in the present invention, the processor receives a trigger frame instructing one or more STAs to transmit a PPDU, and receives a multi-STA Block ACK frame in response to the PPDU, and if at least one of the one or more STAs transmitting the PPDU in response to the trigger frame includes the legacy STA, the size of the Ack information for each of the at least one STA included in the multi-STA Block ACK frame is limited to a specific size or less.

[0025] In addition, in the present invention, when at least one of the one or more STAs transmitting the PPDU in response to the trigger frame includes the legacy STA, and the multi-STA Block ACK frame is transmitted via a resource unit (RU) individually allocated to the STA by the AP, the size of the Ack information is not limited to or less than the specific size.

[0026] The present invention also provides a method including the steps of receiving a management frame including a first operating element and a second operating element from an AP, the first operating element indicating a BSS operating channel for a legacy STA and the second operating element indicating a BSS operating channel for the STA that is not the legacy STA, and transmitting a PPDU to the AP based on the first operating element or the second operating element, wherein if the BSS operating channel for the STA includes at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is different from the BSS operating channel for the STA indicated by the second operating element. Effect of the Invention

[0027] According to one embodiment of the present invention, the present invention provides a method for setting up another BSS operating channel in a legacy terminal, thereby providing an effect of efficiently setting up a BSS operating channel in each terminal.

[0028] In addition, the present invention has an effect of allowing a terminal to efficiently transmit uplink frames by indicating unavailable subchannels included in a BSS operating channel.

[0029] In addition, when transmitting a response frame to terminals including legacy terminals, the present invention provides a method for determining the size of response information for each terminal, thereby having the effect of transmitting response information that each terminal can support.

[0030] The effects obtained from the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from the following description. [Brief description of the drawings]

[0031] [Figure 1]FIG. 1 is a diagram showing a wireless LAN system according to an embodiment of the present invention. [Diagram 2] FIG. 11 is a diagram showing a wireless LAN system according to another embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram showing a configuration of a station according to an embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing the configuration of an access point according to an embodiment of the present invention. [Diagram 5] 1 is a diagram illustrating a process in which a STA sets up a link with an AP. [Figure 6] FIG. 1 is a diagram illustrating a CSMA (Carrier Sense Multiple Access) / CA (Collision Avoidance) method used in wireless LAN communication. [Figure 7] 1 shows examples of various standard generation PPDU (PLCP Protocol Data Unit) formats. [Figure 8] 1 illustrates an example of various Extremely High Throughput (EHT) Physical Protocol Data Unit (PPDU) formats and a method for indicating the same according to an embodiment of the present invention. [Figure 9] FIG. 1 illustrates a multi-link device according to an embodiment of the present invention. [Figure 10] A diagram showing an example of a TID-to-link mapping method according to one embodiment of the present invention. [Figure 11] A diagram showing an example of a multi-link NAV setting operation according to one embodiment of the present invention. [Figure 12] A diagram showing yet another example of a multi-link NAV setting operation according to one embodiment of the present invention. [Figure 13] FIG. 2 is a diagram showing an example of BSS classification and operations based thereon according to an embodiment of the present invention. [Figure 14] 1 shows a wireless LAN function according to an embodiment of the present invention. [Figure 15]1 illustrates an uplink (UL) multi-user (MU) operation according to one embodiment of the present invention. [Figure 16] 1 shows a trigger frame format according to one embodiment of the present invention. [Figure 17] 1 illustrates a method for indicating a trigger-based PPDU format according to one embodiment of the present invention. [Figure 18] 1 illustrates an example of UL MU operation according to one embodiment of the present invention. [Figure 19] 13 is a diagram showing the format of a Block ACK frame according to an embodiment of the present invention. [Figure 20] FIG. 13 is a diagram showing a Fragment Number subfield and a Block ACK Bitmap subfield according to an embodiment of the present invention. [Figure 21] A diagram showing a Multi-STA Block ACK frame being transmitted in response to an HE TB PPDU according to an embodiment of the present invention. [Figure 22] FIG. 2 illustrates a UL MU operation according to an embodiment of the present invention. [Diagram 23] FIG. 2 illustrates a UL MU operation and a format of a Multi-STA Block ACK frame according to an embodiment of the present invention. [Figure 24] FIG. 13 illustrates a UL MU operation and a format of a Multi-STA Block ACK frame according to another embodiment of the present invention. [Diagram 25] A diagram showing the transmission of a management frame according to an embodiment of the present invention. [Figure 26] A diagram showing a method of transmitting a management frame when TID-to-link mapping is applied according to an embodiment of the present invention. [Figure 27] A diagram showing a method of transmitting a management frame when TID-to-link mapping is applied according to another embodiment of the present invention. [Figure 28]FIG. 2 illustrates a management frame and channel width signaling according to one embodiment of the present invention. [Figure 29] A diagram illustrating setting the width of a BSS operating channel according to one embodiment of the present invention. [Diagram 30] A diagram showing setting the width of a BSS operating channel according to another embodiment of the present invention. [Diagram 31] FIG. 2 illustrates channelization and BSS operating channel width setting according to one embodiment of the present invention. [Diagram 32] FIG. 2 is a diagram showing an EHT operation element format according to one embodiment of the present invention. [Diagram 33] FIG. 13 is a diagram illustrating an example of transmission taking into account disabled subchannels according to an embodiment of the present invention. [Diagram 34] FIG. 2 illustrates an example of signaling of a deactivated subchannel according to one embodiment of the present invention. [Diagram 35] FIG. 1 illustrates signaling of deactivated subchannels and critical updates according to one embodiment of the present invention. [Diagram 36] FIG. 13 illustrates signaling of deactivated subchannels and important updates according to another embodiment of the present invention. [Figure 37] FIG. 2 is a diagram showing an EHT operation element format according to one embodiment of the present invention. [Figure 38] A diagram showing an EHT operation element format according to another embodiment of the present invention. [Figure 39] 4 is a flowchart illustrating an example of an operation of a terminal according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] The terms used in this specification are selected as general terms that are currently widely used as much as possible in consideration of the functions of the present invention, but this may vary depending on the intentions, customs, or the emergence of new technologies of the engineers in the relevant technical field. In addition, in certain cases, the applicant may arbitrarily select terms, and in such cases, the meanings of the terms will be described in the description of the relevant invention. Therefore, it is clear that the terms used in this specification should be interpreted not simply as terms, but based on the substantial meanings of the terms and the contents of this specification as a whole.

[0033] Throughout the specification, when a certain component is "connected" to another component, this includes not only when it is "directly connected" to another component, but also when it is "electrically connected" with another component therebetween. Furthermore, when a certain component "includes" a certain component, this means that it may further include the other component, not excluding the other component, unless otherwise specified. In addition, limitations such as "greater than" or "less than" based on a specific critical value may be appropriately replaced with "more than" or "less than", respectively, depending on the embodiment. Hereinafter, in the present invention, the terms "field" and "subfield" may be used interchangeably.

[0034] FIG. 1 is a diagram showing a wireless LAN system according to an embodiment of the present invention.

[0035] A wireless LAN system includes one or more Basic Service Sets (BSS), which are a set of devices that can successfully synchronize and communicate with each other. Generally, BSSs are classified into infrastructure BSSs and independent BSSs (IBSSs), and Figure 1 shows an infrastructure BSS.

[0036] As shown in FIG. 1, infrastructure BSS BSS1, BSS2 includes one or more stations STA1, STA2, STA3, STA4, STA5, access points AP-1, AP-2 which are stations providing a distribution service, and a distribution system DS which connects multiple access points AP-1, AP-2.

[0037] A station (STA) is any device including a medium access control (MAC) and a physical layer interface for a wireless medium according to the IEEE 802.11 standard, and in a broad sense includes not only non-AP stations but also APs. In this specification, the term "terminal" refers to either a non-AP or an AP, or both. A station for wireless communication includes a processor and a communication unit, and further includes a user interface unit and a display unit, etc., depending on the embodiment. The processor generates frames to be transmitted through a wireless network, processes frames received through the wireless network, and performs various other processes for controlling the station. The communication unit is functionally connected to the processor and transmits and receives frames through the wireless network for the station. In the present invention, the term "terminal" is used to include a user equipment (UE).

[0038] An access point (AP) is an entity that provides a connection to a distribution system DS via a wireless medium for a station associated therewith. In an infrastructure BSS, communication between non-AP stations is generally performed via the AP, but when a direct link is set up, direct communication is possible between non-AP stations. Meanwhile, in the present invention, AP is used as a concept including a personal BSS coordination point (PCP), but in a broad sense, AP includes all concepts such as a central controller, a base station (BS), a node B, a base transceiver system (BTS), or a site controller. In the present invention, AP is also referred to as a base wireless communication terminal, but in a broad sense, the base wireless communication terminal is used as a term including an AP, a base station, an eNodeB (eNB), and a transmission point TP. In addition, the base wireless communication terminal includes various types of wireless communication terminals that allocate communication medium resources and perform scheduling in communication with a plurality of wireless communication terminals.

[0039] A plurality of infrastructure BSSs are connected to each other via a distribution system DS. In this case, a plurality of BSSs connected to each other via the distribution system is called an Extended Service Set (ESS).

[0040] 2 is a diagram showing an independent BSS, which is a wireless LAN system according to another embodiment of the present invention, in which the same or corresponding parts in the embodiment of FIG. 2 are the same as or correspond to the embodiment of FIG.

[0041] BSS3 shown in Figure 2 is an independent BSS and does not include an AP, so all stations (STA6, STA7) are not connected to an AP. An independent BSS is not allowed to connect to a distribution system and forms a self-contained network. In an independent BSS, each station (STA6, STA7) is directly connected to each other.

[0042] 3 is a block diagram showing a configuration of a station 100 according to an embodiment of the present invention. As shown in the figure, the station 100 according to the embodiment of the present invention includes a processor 110, a communication unit 120, a user interface unit 140, a display unit 150, and a memory 160.

[0043] First, the communication unit 120 transmits and receives wireless signals such as wireless LAN packets, and may be built into or externally provided in the station 100. According to an embodiment, the communication unit 120 may include at least one communication module using different frequency bands. For example, the communication unit 120 may include communication modules of different frequency bands such as 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz. According to an embodiment, the station 100 may include a communication module using a frequency band of 7.125 GHz or more and a communication module using a frequency band of 7.125 GHz or less. Each communication module may perform wireless communication with an AP or an external station based on the wireless LAN standard of the frequency band supported by the communication module. The communication unit 120 may operate only one communication module at a time or operate multiple communication modules simultaneously according to the performance and requirements of the station 100. When the station 100 includes multiple communication modules, each communication module may be provided in an independent form, or multiple modules may be integrated into one chip. In an embodiment of the present invention, the communication unit 120 may represent a radio frequency (RF) communication module that processes RF signals.

[0044] Next, the user interface 140 includes various types of input / output means provided in the station 100. That is, the user interface unit 140 receives user input using various input means, and the processor 110 controls the station 100 based on the received user input. Also, the user interface unit 140 performs output based on a command from the processor 110 using various output means.

[0045] Then, the display unit 150 outputs an image on a display screen. The display unit 150 outputs various display objects such as a user interface based on the contents performed by the processor 110 or a control command of the processor 110. The memory 160 also stores control programs used by the station 100 and various data associated therewith. Such control programs include connection programs required for the station 100 to connect to an AP or an external station.

[0046] The processor 110 of the present invention executes various commands or programs to process data within the station 100. The processor 110 also controls each unit of the station 100 and controls transmission and reception of data between the units. According to an embodiment of the present invention, the processor 110 executes a program for connection to an AP stored in the memory 160 and receives a communication setup message transmitted by the AP. The processor 110 also reads information on the priority conditions of the station 100 included in the communication setup message and requests a connection to the AP based on the information on the priority conditions of the station 100. The processor 110 of the present invention may refer to a main control unit of the station 100, or may refer to a control unit for individually controlling some components of the station 100, for example, the communication unit 120, depending on the embodiment. That is, the processor 110 may be a modem that modulates and demodulates a wireless signal transmitted and received from the communication unit 120, or a modulator and / or demodulator. The processor 110 controls various operations of transmitting and receiving wireless signals of the station 100 according to an embodiment of the present invention. A detailed embodiment of the present invention will be described later.

[0047] The station 100 shown in FIG. 3 is a block diagram according to an embodiment of the present invention, and the separate blocks are used to logically distinguish between elements of the device. Thus, the above-mentioned device elements may be mounted on one chip or multiple chips depending on the design of the device. For example, the processor 110 and the communication unit 120 may be integrated and embodied on one chip, or may be embodied on separate chips. In addition, in an embodiment of the present invention, some components of the station 100, such as the user interface unit 140 and the display unit 150, may be selectively provided in the station 100.

[0048] 4 is a block diagram showing a configuration of an AP 200 according to an embodiment of the present invention. As shown in the figure, the AP 200 according to the embodiment of the present invention includes a processor 210, a communication unit 220, and a memory 260. In FIG. 4, a duplicated description of parts of the configuration of the AP 200 that are the same as or correspond to the configuration of the station 100 in FIG. 3 will be omitted.

[0049] Referring to FIG. 4, the AP 200 according to the present invention includes a communication unit 220 for operating a BSS in at least one frequency band. As described above in the embodiment of FIG. 3, the communication unit 220 of the AP 200 may also include a plurality of communication modules using different frequency bands. That is, the AP 200 according to the embodiment of the present invention may include two or more communication modules using different frequency bands, for example, any of 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz. Preferably, the AP 200 may include a communication module using a frequency band of 7.125 GHz or higher and a communication module using a frequency band of 7.125 GHz or lower. Each communication module may perform wireless communication with a station based on the WLAN standard of the frequency band supported by the communication module. The communication unit 220 may operate only one communication module at a time or operate multiple communication modules simultaneously according to the performance and requirements of the AP 200. In the embodiment of the present invention, the communication unit 220 may represent an RF communication module that processes RF (Radio Frequency) signals.

[0050] Next, the memory 260 stores control programs used in the AP 200 and various data associated therewith. Such control programs include a connection program for managing station connections. Also, the processor 210 controls each unit of the AP 200 and controls transmission and reception of data between the units. According to an embodiment of the present invention, the processor 210 executes a program for connection with a station stored in the memory 260 and transmits a communication setting message to one or more stations. At this time, the communication setting message includes information regarding connection priority conditions of each station. Also, the processor 210 performs connection setting in response to a connection request of a station. According to an embodiment, the processor 210 is a modem or a modulation / demodulation unit that modulates and demodulates wireless signals transmitted and received from the communication unit 220. The processor 210 controls various operations of transmitting and receiving wireless signals of the AP 200 according to an embodiment of the present invention. A detailed embodiment thereof will be described later.

[0051] FIG. 5 is a diagram illustrating a process in which a STA establishes a link with an AP.

[0052] 5, the link between the STA 100 and the AP 200 is set up through three steps: scanning, authentication, and association. First, the scanning step is a step in which the STA 100 acquires connection information of the BSS operated by the AP 200. There are two methods for performing scanning: a passive scanning method in which the AP 200 acquires information only by using a beacon message S101 periodically transmitted by the AP, and an active scanning method in which the STA 100 transmits a probe request to the AP S103, receives a probe response from the AP S105, and acquires connection information.

[0053] The STA 100 that has successfully received wireless connection information in the scanning step transmits an authentication request (S107a), receives an authentication response from the AP 200 (S107b), and performs an authentication step. After the authentication step is performed, the STA 100 transmits an association request (S109a), receives an association response from the AP 200, and performs an association step (S109b). In this specification, association basically means wireless association, but the present invention is not limited thereto, and association in a broad sense includes both wireless association and wired association.

[0054] Meanwhile, an 802.1X-based authentication step S111 and an IP address acquisition step S113 via DHCP are additionally performed. In Fig. 5, the server 300 is a server that processes 802.1X-based authentication with the STA 100, and may be physically connected to the AP 200 or may exist as a separate server.

[0055] FIG. 6 is a diagram showing a Carrier Sense Multiple Access (CSMA) / Collision Avoidance (CA) method used in wireless LAN communication.

[0056] A terminal performing wireless LAN communication performs carrier sensing before transmitting data to check whether a channel is occupied or not. If a wireless signal of a certain strength or more is detected, the channel is determined to be occupied and the terminal delays access to the channel. This process is called Clear Channel Assessment (CCA), and the level that determines whether or not the signal is detected is called the CCA threshold. If a wireless signal of a strength greater than the CCA threshold is received by the terminal and the terminal is the receiver, the terminal processes the received wireless signal. On the other hand, if no wireless signal is detected from the channel or a wireless signal of a strength less than the CCA threshold is detected, the channel is determined to be idle.

[0057] If the channel is determined to be in an idle state, each terminal having data to transmit performs a backoff procedure after an IFS (Inter Frame Space) time, such as an AIFS (Arbitration IFS) or a PIFS (PCF IFS), depending on the status of each terminal. In some embodiments, the AIFS is used as a configuration to replace the conventional DIFS (DCF IFS). Each terminal waits while decreasing a slot time of a random number determined for the corresponding terminal during an interval of the idle state of the channel, and a terminal that has exhausted all the slot time attempts to access the corresponding channel. The period in which each terminal performs a backoff procedure is called a contention window period.

[0058] If a specific terminal succeeds in accessing the channel, the terminal transmits data through the channel. However, if the terminal attempting access collides with another terminal, the colliding terminals are assigned new random numbers and perform a backoff procedure again. According to one embodiment, the random numbers newly assigned to each terminal are determined within a range (2*CW) twice the range of the random numbers previously assigned to the terminal (contention window, CW). Meanwhile, each terminal attempts access by performing a backoff procedure again in the next contention window period, and at this time, each terminal performs the backoff procedure from the slot time remaining in the previous contention window period. In this manner, each terminal performing wireless LAN communication can avoid collision with each other on a specific channel.

[0059] Hereinafter, in the present invention, a terminal can be called a non-AP STA, an AP STA, an AP, an STA, a receiving device, or a transmitting device, and the present invention is not limited thereto. Also, in the present invention, an AP STA can be called an AP.

[0060] <Examples of various PPDU formats>

[0061] FIG 7 shows an example of various standard generation PPDU (PLCP Protocol Data Unit) formats. More specifically, FIG 7(a) shows an example of a legacy PPDU format based on 802.11a / g, FIG 7(b) shows an example of a HE PPDU format based on 802.11ax, and FIG 7(c) shows an example of a non-legacy PPDU (i.e., EHT PPDU) format based on 802.11be. Also, FIG 7(d) shows detailed field configurations of L-SIG and RL-SIG commonly used in the PPDU formats.

[0062] 7(a), the preamble of the legacy PPDU includes a legacy short training field (L-STF), a legacy long training field (L-LTF), and a legacy signal field (L-SIG). In an embodiment of the present invention, the L-STF, L-LTF, and L-SIG may be referred to as a legacy preamble.

[0063] Referring to FIG. 7(b), the preamble of the HE PPDU further includes a RL-SIG (Repeated Legacy Short Training field), a HE-SIG-A (High Efficiency Signal A field), a HE-SIG-B (High Efficiency Signal B field), a HE-STF (High Efficiency Short Training field), and a HE-LTF (High Efficiency Long Training field) in addition to the legacy preamble. In an embodiment of the present invention, the RL-SIG, HE-SIG-A, HE-SIG-B, HE-STF, and HE-LTF can be referred to as an HE preamble. The specific configuration of the HE preamble may be modified according to the HE PPDU format. For example, the HE-SIG-B may be used only in the HE MU PPDU format.

[0064] Referring to FIG. 7(c), the preamble of the EHT PPDU further includes a RL-SIG (Repeated Legacy Short Training field), a U-SIG (Universal Signal field), an EHT-SIG-A (Extremely High Throughput Signal A field), an EHT-SIG-A (Extremely High Throughput Signal B field), an EHT-STF (Extremely High Throughput Short Training field), and an EHT-LTF (Extremely High Throughput Long Training field) in addition to the legacy preamble. In an embodiment of the present invention, the RL-SIG, EHT-SIG-A, EHT-SIG-B, EHT-STF, and EHT-LTF can be called an EHT preamble. The specific configuration of the non-legacy preamble may be modified according to the EHT PPDU format. For example, EHT-SIG-A and EHT-SIG-B may be used only in some formats of the EHT PPDU format.

[0065] The L-SIG field included in the preamble of the PPDU is configured with a total of 64 subcarriers by applying 64 FFT OFDM. Of these, 48 subcarriers excluding the guard subcarriers, DC subcarriers, and pilot subcarriers are used for L-SIG data transmission. Since BPSK and Rate=1 / 2 MCS (Modulation and Coding Scheme) are applied to the L-SIG, it can contain a total of 24 bits of information. Figure 7(d) shows the 24-bit information configuration of the L-SIG.

[0066] Referring to FIG. 7(d), the L-SIG includes an L_RATE field and an L_LENGTH field. The L_RATE field is composed of 4 bits and indicates the MCS used for data transmission. Specifically, the L_RATE field indicates one of the transmission rates of 6 / 9 / 12 / 18 / 24 / 36 / 48 / 54 Mbps, which is a combination of a modulation method such as BPSK / QPSK / 16-QAM / 64-QAM and a code rate such as 1 / 2, 2 / 3, or 3 / 4. The total length of the PPDU can be indicated by combining the information of the L_RATE field and the L_LENGTH field. In the non-legacy PPDU format, the L_RATE field is set to the minimum rate of 6 Mbps.

[0067] The unit of the L_LENGTH field is a byte, and a total of 12 bits are assigned to signal up to 4095. In combination with the L_RATE field, it can indicate the length of the corresponding PPDU. In this case, legacy and non-legacy terminals can interpret the L_LENGTH field in different ways.

[0068] First, the method in which a legacy or non-legacy terminal interprets the length of the corresponding PPDU using the L_LENGTH field is as follows. When the value of the L_RATE field is set to indicate 6 Mbps, 3 bytes (i.e., 24 bits) may be transmitted during 4 us, which is one symbol duration of 64 FFT. Therefore, the number of 64 FFT reference symbols after the L-SIG is obtained by adding 3 bytes corresponding to the SVC field and the Tail field to the L_LENGTH field value and dividing it by 3 bytes, which is the transmission amount of one symbol. The length of the corresponding PPDU, i.e., the reception time (RXTIME), is obtained by multiplying the number of symbols obtained by 4 us, which is one symbol duration, and then adding 20 us for transmitting the L-STF, L-LTF, and L-SIG. This can be expressed as the following Equation 1.

[0069]

number

[0070] At this time,

number

[0071]

number

[0072] Here, TXTIME is the total transmission time constituting the PPDU, and is expressed as the following Equation 3. In this case, TX represents the transmission time of X.

[0073]

number

[0074] Referring to the above formula, the length of the PPDU is calculated based on the rounded up value of L_LENGTH / 3. Therefore, for any value of k, three different values ​​of L_LENGTH={3k+1, 3k+2, 3(k+1)} indicate the same PPDU length.

[0075] Referring to FIG. 7(e), the U-SIG (Universal SIG) field remains in the EHT PPDU and the PPDU of the succeeding generation of WLAN, and plays a role in identifying which generation of PPDU it is, including 11be. The U-SIG is two symbols of 64FFT-based OFDM and can transmit a total of 52 bits of information. Of these, 43 bits excluding the CRC / tail 9 bits are roughly divided into a VI (Version Independent) field and a VD (Version Dependent) field.

[0076] The VI bit will maintain the current bit configuration, and even if a subsequent generation PPDU is defined, a current 11be terminal can obtain information about the PPDU from the VI field of the PPDU. To this end, the VI field is composed of PHY version, UL / DL, BSS color, TXOP, and Reserved fields. The PHY version field is 3 bits, and serves to sequentially distinguish 11be and subsequent generation WLAN standards by version. 11be has a value of 000b. The UL / DL field distinguishes whether the corresponding PPDU is an uplink / downlink PPDU. The BSS color means a BSS-specific identifier defined in 11ax, and has a value of 6 bits or more. The TXOP means a transmit opportunity duration that was transmitted in the MAC header, but by adding it to the PHY header, the length of the TXOP containing the corresponding PPDU can be inferred without decoding the MPDU, and has a value of 7 bits or more.

[0077] The VD field may be composed of fields commonly used in any PPDU format, such as PPDU format and BW, which are signaling information useful only for PPDUs of the 11be version, and fields defined differently for each PPDU format. The PPDU format is a division factor that distinguishes EHT SU (Single User), EHT MU (Multiple User), EHT TB (Trigger-based), EHT ER (Extended Range) PPDU, etc. The BW field mainly signals five basic PPDU BW options of 20, 40, 80, 160 (80+80), and 320 (160+160) MHz (BWs that can be expressed in the form of a power of 20*2 can be called basic BWs), and various remaining PPDU BWs formed by preamble puncturing. After being signaled at 320 MHz, some 80 MHz may be signaled in a punctured form. Also, the punctured and modified channel shape may be directly signaled in the BW field, or may be signaled using both the BW field and a field that appears after the BW field (e.g., a field in the EHT-SIG field). If the BW field is 3 bits, a total of 8 BW signalings are possible, so a maximum of 3 puncturing modes can be signaled. If the BW field is 4 bits, a total of 16 BW signalings are possible, so a maximum of 11 puncturing modes can be signaled.

[0078] The fields located after the BW field vary depending on the type and format of the PPDU. The MU PPDU and the SU PPDU may be signaled in the same PPDU format, and a field for distinguishing the MU PPDU from the SU PPDU may be located before the EHT-SIG field, and additional signaling may be performed for this purpose. Both the SU PPDU and the MU PPDU include an EHT-SIG field, but some fields that are not necessary in the SU PPDU may be compressed. In this case, the information of the compressed field may be omitted or may have a reduced size compared to the size of the original field included in the MU PPDU. For example, in the case of the SU PPDU, the common field of the EHT-SIG may be omitted or replaced, or the user-specific field may be replaced or reduced to one, and may have a different configuration.

[0079] Alternatively, the SU PPDU may further include a compression field indicating whether or not it is compressed, and some fields (eg, the RA field, etc.) may be omitted depending on the value of the compression field.

[0080] When a part of the EHT-SIG field of the SU PPDU is compressed, the information included in the compressed field may be signaled together in an uncompressed field (e.g., a common field, etc.). In the case of the MU PPDU, since it is a PPDU format for simultaneous reception by multiple users, the EHT-SIG field must be transmitted after the U-SIG field, and the amount of information signaled may be variable. That is, since multiple MU PPDUs are transmitted to multiple STAs, each STA must recognize the location of the RU to which the MU PPDU is transmitted, the STA to which each RU is assigned, and whether the transmitted MU PPDU was transmitted to itself. Therefore, the AP must transmit the above information in the EHT-SIG field. To this end, the U-SIG field signals information for efficiently transmitting the EHT-SIG field, which may be the number of symbols of the EHT-SIG field and / or MCS, which is a modulation method. The EHT-SIG field may include the size and location information of the RU assigned to each user.

[0081] In the case of a SU PPDU, a STA may be assigned multiple RUs, and the multiple RUs may be contiguous or discontinuous. If the RUs assigned to the STA are not contiguous, the STA can receive the SU PPDU efficiently only by recognizing the RUs punctured in between. Therefore, the AP can transmit the SU PPDU including information on the punctured RUs among the RUs assigned to the STA (e.g., the puncturing pattern of the RUs, etc.). That is, in the case of a SU PPDU, a puncturing mode field including information indicating whether a puncturing mode is applied and the puncturing pattern in a bitmap format, etc., may be included in the EHT-SIG field, and the puncturing mode field may signal the type of discontinuous channels that appear within the bandwidth.

[0082] The form of the signaled discontinuous channel is limited, and indicates the BW and discontinuous channel information of the SU PPDU in combination with the value of the BW field. For example, in the case of a SU PPDU, since it is a PPDU transmitted only to a single UE, the STA can recognize the bandwidth allocated to itself from the BW field included in the PPDU, and can recognize the punctured resources of the allocated bandwidth from the puncturing mode field of the U-SIG field or EHT-SIG field included in the PPDU. In this case, the UE can receive the PPDU in the remaining resource units except for the specific channel of the punctured resource unit. In this case, the multiple RUs allocated to the STA may be configured with different frequency bands or tones.

[0083] The reason why only limited discontinuous channel types are signaled is to reduce the signaling overhead of SU PPDU. Since puncturing may be performed for each 20 MHz subchannel, if puncturing is performed for a BW having multiple 20 MHz subchannels such as 80, 160, and 320 MHz, in the case of 320 MHz, the discontinuous channel type (when only the end 20 MHz is punctured and considered as discontinuous) must be signaled by expressing whether or not the remaining 15 20 MHz subchannels except the primary channel are used. In this way, using 15 bits to signal discontinuous channel types for single user transmission may result in excessive signaling overhead when considering the low transmission speed of the signaling part.

[0084] The present invention proposes a method for signaling the discontinuous channel type of the SU PPDU, shows the discontinuous channel type determined by the proposed method, and proposes a method for signaling the puncturing types of the primary 160 MHz and secondary 160 MHz in the 320 MHz BW configuration of the SU PPDU.

[0085] In addition, in one embodiment of the present invention, a method is proposed in which the configuration of the PPDU indicated by the preamble puncturing BW value is changed according to the PPDU format signaled in the PPDU format field. Assuming that the length of the BW field is 4 bits, in the case of an EHT SU PPDU or TB PPDU, one symbol of EHT-SIG-A may be further signaled after the U-SIG, or EHT-SIG-A may not be signaled at all. Taking this into consideration, it is necessary to signal up to 11 puncturing modes using only the BW field of the U-SIG. However, in the case of an EHT MU PPDU, since an EHT-SIG-B is further signaled after the U-SIG, up to 11 puncturing modes may be signaled in a different manner from the SU PPDU. In the case of an EHT ER PPDU, the BW field is set to 1 bit, and it is possible to signal whether the PPDU uses a bandwidth of 20 MHz or 10 MHz.

[0086] FIG. 7(f) shows the format-specific field configuration of the VD field when the PPDU format field of the U-SIG indicates EHT MU PPDU. In the case of MU PPDU, SIG-B, which is a signaling field for simultaneous reception by multiple users, is required, and SIG-B may be transmitted after U-SIG without a separate SIG-A. For this purpose, U-SIG must signal information for decoding SIG-B. Such fields include SIG-B MCS, SIG-B DCM, Number of SIG-B Symbols, SIG-B Compression, and Number of EHT-LTF Symbols.

[0087] FIG. 8 illustrates an example of various Extremely High Throughput (EHT) Physical Protocol Data Unit (PPDU) formats and a method for indicating the same according to an embodiment of the present invention.

[0088] 8, a PPDU may be composed of a preamble and a data portion, and the format of an EHT PPDU, which is one type, may be distinguished by a U-SIG field included in the preamble. Specifically, whether the format of the PPDU is an EHT PPDU may be indicated based on a PPDU format field included in the U-SIG field.

[0089] 8(a) shows an example of an EHT SU PPDU format for a single STA. The EHT SU PPDU is a PPDU used for single user (SU) transmission between an AP and a single STA, and an EHT-SIG-A field for additional signaling may be located after the U-SIG field.

[0090] 8(b) shows an example of an EHT trigger-based PPDU format, which is an EHT PPDU transmitted based on a trigger frame. The EHT trigger-based PPDU is an EHT PPDU transmitted based on a trigger frame, and is an uplink PPDU used for responding to the trigger frame. Unlike the EHT SU PPDU, the EHT PPDU does not have an EHT-SIG-A field after the U-SIG field.

[0091] 8(c) shows an example of an EHT MU PPDU format, which is an EHT PPDU for multiple users. The EHT MU PPDU is a PPDU used to transmit a PPDU to one or more STAs. In the EHT MU PPDU format, an HE-SIG-B field may be located after the U-SIG field.

[0092] Fig. 8(d) shows an example of an EHT ER SU PPDU format used for single-user transmission with an STA in an extended range. The EHT ER SU PPDU may be used for single-user transmission with a STA in a wider range than the EHT SU PPDU described in Fig. 8(a), and the U-SIG field may be repeatedly positioned on the time axis.

[0093] The EHT MU PPDU described in (c) of FIG. 8 can be used by the AP for downlink transmission to multiple STAs. In this case, the EHT MU PPDU can include scheduling information so that multiple STAs can simultaneously receive the PPDU transmitted from the AP. The EHT MU PPDU can convey AID information of the receiver and / or sender of the PPDU transmitted through the user specific field of the EHT-SIG-B to the STA. Therefore, multiple terminals receiving the EHT MU PPDU can perform spatial reuse based on the AID information of the user specific field included in the preamble of the received PPDU.

[0094] Specifically, the resource unit allocation (RA) field of the HE-SIG-B field included in the HE MU PPDU may include information regarding a resource unit configuration (e.g., a resource unit division form) in a specific bandwidth (e.g., 20 MHz, etc.) on the frequency axis. That is, the RA field may indicate a resource unit configuration divided by a bandwidth for transmitting the HE MU PPDU so that the STA receives the PPDU. Information on the STA allocated (or designated) to each divided resource unit may be included in a user specific field of the EHT-SIG-B and transmitted to the STA. That is, the user specific field may include one or more user fields corresponding to each divided resource unit.

[0095] For example, a user field corresponding to at least one resource unit used for data transmission among the multiple divided resource units may include the AID of a receiver or sender, and a user field corresponding to the remaining resource units not used for data transmission may include a null STA ID that has already been set.

[0096] Two or more PPDUs shown in FIG. 8 can be indicated by a value indicating the same PPDU format. That is, two or more PPDUs can be indicated as the same PPDU format by the same value. For example, EHT SU PPDU and EHT MU PPDU can be indicated by the same value using the U-SIG PPDU format subfield. In this case, EHT SU PPDU and EHT MU PPDU can be distinguished according to the number of STAs receiving the PPDU. For example, a PPDU received by only one STA can be identified as an EHT SU PPDU, and when the number of STAs is set so that two or more STAs receive the PPDU, it can be identified as an EHT MU PPDU. In other words, two or more PPDU formats shown in FIG. 8 can be indicated by using the same subfield value.

[0097] In addition, some of the fields or some information of the fields shown in FIG. 8 may be omitted, and such a case in which some of the fields or some information of the fields is omitted can be defined as a compression mode.

[0098] FIG. 9 is a diagram showing a multi-link device according to an embodiment of the present invention.

[0099] Referring to FIG. 9, a concept of a device to which one or more STAs are affiliated may be defined. As yet another embodiment, according to an embodiment of the present invention, a device to which more than one STA is affiliated (i.e., two or more) may be defined. In this case, the device may be a logical concept. Therefore, such a concept of a device to which one or more STAs are affiliated may be called a multi-link device (MLD), a multi-band device, or a multi-link logical entity (MLLE).

[0100] Or the above conceptual device can be called a multi-link entity (MLE), and the MLD may have one MAC medium access control service access point (SAP) to a logical link control (LLC), and the MLD may have one MAC data service.

[0101] A STA included in an MLD can operate on one or more links or channels. That is, a STA included in an MLD can operate on multiple different channels. For example, a STA included in an MLD can operate using channels of different frequency bands such as 2.4 GHz, 5 GHz, and 6 GHz. As a result, MLD can obtain gains in channel access and improve the performance of the entire network. While the existing wireless LAN operates on a single link, MLD operation can obtain more channel access opportunities using multiple links, or STA can operate efficiently on multiple links taking into account channel conditions.

[0102] Also, if the STA affiliated to the MLD is an AP, the MLD to which the AP is affiliated may be an AP MLD, but if the STA affiliated to the MLD is a non-AP STA, the MLD to which the non-AP is affiliated may be a non-AP MLD.

[0103] Also, an AP MLD (Multi-link Device) may be a device including one or more wireless access points (APs) and connected to a higher layer via one interface. That is, the AP MLD may be connected to a Logical Link Control (LLC) layer via one interface. Multiple APs included in the AP MLD may share some functions in the MAC layer. Each AP in the AP MLD may operate on an individual link. An STA MLD may be a device including one or more non-AP STAs and connected to a higher layer via one interface.

[0104] That is, the STA MLD may be connected to the LLC layer through one interface. A plurality of STAs included in the STA MLD may share some functions in the MAC layer. The STA MLD may also be called a non-AP MLD. In this case, the AP MLD and the STA MLD may perform a multi-link operation in which communication is performed using a plurality of individual links. That is, when the AP MLD includes a plurality of APs, each AP may configure a separate link and perform frame transmission / reception operations using the plurality of links with each terminal included in the STA MLD. In this case, each link may operate in a 2.4 GHz, 5 GHz, or 6 GHz band, and each link may perform a bandwidth extension operation. For example, when the AP MLD sets one link in the 2.4 GHz band and two links in the 5 GHz band, the 2.4 GHz band may transmit frames at a bandwidth of 40 MHz using a bandwidth extension method, and each link using the 5 GHz band may transmit frames at a maximum bandwidth of 320 MHz using discontinuous bandwidths.

[0105] Meanwhile, the AP MLD or STA MLD may not allow a terminal in the MLD to receive while another terminal in the MLD is transmitting due to interference issues within the device. Such an operation in which one AP or terminal in the MLD receives while another AP or terminal in the MLD is transmitting is called STR (Simultaneous Transmit and Receive). The AP MLD is capable of STR operation for all links. Or, STR operation is not possible for some links of the AP MLD. An STR-capable terminal MLD may be connected to the AP MLD, or an STR-incapable MLD may be connected to some or all links. In addition, a terminal (e.g., IEEE 802.11a / b / g / n / ac / ax terminal) that does not belong to the MLD may be further connected to an AP included in the AP MLD.

[0106] The AP MLD and the STA MLD can perform a negotiation process for a multiple link use operation in the scanning and connection process described in FIG 5. For example, in the scanning process described in FIG 5, the AP included in the AP MLD can transmit a beacon frame including an indicator indicating that the multiple link operation is available, the number of available links, and information on a number of available links. Alternatively, a terminal belonging to the STA MLD can transmit a probe request frame including an indicator indicating that the multiple link operation is available, and an AP belonging to the AP MLD can transmit a probe response frame including an indicator indicating that the multiple link operation is available. In this case, the AP can transmit a probe response frame including the number of available links, link information, etc. during the multiple link operation.

[0107] The STA MLD, which has confirmed whether the AP MLD performs a multi-link operation and the link information to be used during the scanning process, can perform a connection process with the AP MLD. At this time, the AP MLD and the STA MLD can start a negotiation process for the multi-link operation. At this time, the negotiation process for the multi-link operation can be performed during a connection process between an AP belonging to the AP MLD and a terminal belonging to the STA MLD. That is, an arbitrary terminal (e.g., STA1) belonging to the STA MLD can transmit an indicator indicating that the terminal's multi-link operation is available and a request indicator requesting the terminal to perform the multi-link operation while transmitting a connection request frame to an arbitrary AP (e.g., AP1) belonging to the AP MLD. The AP receiving the connection request frame from the terminal can confirm the indicator requesting the multi-link operation, and can transmit a connection response frame to the terminal that allows the multi-link operation, including link information used for the multi-link operation and parameters used for each link, if the AP is capable of the multi-link operation. The parameters for the multi-link operation may include one or more of the bandwidth of each link used, the bandwidth expansion direction, a Target Beacon Transmission Time (TBTT), and the presence or absence of an STR operation. The AP MLD and the STA MLD in which the use of the multi-link operation is confirmed by exchanging the connection request frame and the response frame can perform a frame transmission operation on multiple links via multiple APs included in the AP MLD and multiple terminals included in the STA MLD after the connection process.

[0108] 9, there may be an MLD including multiple STAs, and the multiple STAs included in the MLD may operate on multiple links. In FIG. 9, the MLD including AP1, AP2, and AP3 that are APs may be called an AP MLD, and the MLD including non-AP STA1, non-AP STA2, and non-AP STA3 that are non-AP STAs may be called a non-AP MLD. The STAs included in the MLD may operate on Link 1, Link 2, Link 3, or some of the links 1 to 3.

[0109] According to an embodiment of the present invention, the multi-link operation may include a multi-link setup operation. The multi-link setup operation may be an operation corresponding to an association performed in a single-link operation. In order to exchange frames in the multi-link, the multi-link setup must be performed in advance. The multi-link setup operation may be performed using a multi-link setup element. Here, the multi-link setup element may include capability information related to the multi-link, and the capability information may include information on whether a STA included in the MLD can receive a frame in one link and another STA included in the MLD can transmit a frame in another link at the same time. That is, the capability information may include information on whether a STA (non-AP STA and / or an AP (or AP STA) can simultaneously transmit / receive frames in different transmission directions through a link included in the MLD. The capability information may further include information on an available link or an operating channel. The multi-link setup may be set up through negotiation between peer STAs, and the multi-link operation may be set up through one link.

[0110] According to an embodiment of the present invention, a mapping relationship may exist between TIDs and MLD links. For example, when a TID and a link are mapped, the TID may be transmitted on the mapped link. The mapping between TIDs and links may be directional-based. For example, a mapping may be performed for each direction between MLD1 and MLD2. Also, a default setting may exist for the mapping between TIDs and links. For example, the mapping between TIDs and links may basically be that all TIDs are mapped to a certain link.

[0111] FIG. 10 is a diagram illustrating an example of a TID-to-link mapping method according to an embodiment of the present invention.

[0112] Referring to Fig. 10, there may be a mapping relationship between TIDs and links as described in Fig. 9. In addition, in the present invention, the mapping relationship between TIDs and links may be called TID-to-link mapping, TID-to-link mapping, TID mapping, link mapping, etc. The TID may be a traffic identifier. In addition, the TID may be an ID (identifier) ​​that classifies traffic, data, etc. to support quality of service (QoS).

[0113] Also, the TID may be an ID used or assigned in a layer higher than the MAC layer. The TID may indicate TC (traffic categories) and TS (traffic streams). Also, the TID may have 16 possible values, and may be indicated by values ​​from 0 to 15, for example. Also, individual TID values ​​may be used according to an access policy, channel access, or medium access method. For example, when EDCA (HCF (hybrid coordination function) connection-based channel access, extended distributed channel access) is used, the possible TID value may be 0 to 7. Also, when EDCA is used, the TID value may indicate UP (user priority), and the UP may be related to TC or TS. Also, the UP may be a value assigned in a layer higher than the MAC. Also, when HCCA (HCF controlled channel access) or SPCA is used, the possible TID value may be 8 to 15. Also, when HCCA or SPCA is used, the TID may indicate TSID. Furthermore, when HEMM or SEMM is used, the possible TID value may be 8 to 15. Furthermore, when HEMM or SEMM is used, TID may indicate TSID.

[0114] There may also be a mapping relationship between UP and access category (AC). An AC may be a label for providing QoS in EDCA or a label indicating a set of EDCA parameters. The EDCA parameters or the set of EDCA parameters may be used for channel association. An AC may be used in a QoS STA.

[0115] The value of AC may be set to one of AC_BK, AC_BE, AC_VI, and AC_VO. AC_BK, AC_BE, AC_VI, and AC_VO may indicate background, best effort, video, and voice, respectively. AC_BK, AC_BE, AC_VI, and AC_VO can be further subdivided. For example, AC_VI may be further subdivided into AC_VI primary and AC_VI alternate. AC_VO may be further subdivided into AC_VO primary and AC_VO alternate. UP values ​​or TID values ​​may be mapped to AC values. For example, UP values ​​or TID values ​​1, 2, 0, 3, 4, 5, 6, and 7 may be mapped to AC_BK, AC_BK, AC_BE, AC_BE, AC_VI, AC_VI, AC_VO, and AC_VO, respectively. Alternatively, the UP or TID values ​​1, 2, 0, 3, 4, 5, 6, and 7 may be mapped to AC_BK, AC_BK, AC_BE, AC_BE, AC_VI alternate, AC_VI primary, AC_VO primary, and AC_VO alternate, respectively. Also, the UP or TID values ​​1, 2, 0, 3, 4, 5, 6, and 7 may have increasing priority in order. That is, 1 may be a lower priority, and 7 may be a higher priority. Therefore, the order of priority may be AC_BK, AC_BE, AC_VI, and AC_VO. Also, AC_BK, AC_BE, AC_VI, and AC_VO may correspond to ACI (AC index) 0, 1, 2, and 3, respectively.

[0116] Therefore, there may be a relationship between TID and AC. Therefore, the TID-to-link mapping of the present invention may be a mapping relationship between AC and link. Also, in the present invention, the fact that a TID is mapped may mean that an AC is mapped, and vice versa.

[0117] According to an embodiment of the present invention, a TID may be mapped to each link of a multi-link. For example, there may be a mapping for which link among multiple links a specific TID or a specific AC is allowed to transmit or receive on. Also, such mapping may be defined separately for each direction of the link. Also, as described above, there may be a default setting for the mapping between TIDs and links. For example, the mapping between TIDs and links may basically be such that all TIDs are mapped to a certain link. Also, according to an embodiment, at a specific time, a certain TID or a certain AC may be mapped to at least one link. Also, a management frame or a control frame may be transmitted on all links.

[0118] In the present invention, a data frame corresponding to a TID or AC that is mapped to either direction of the link may be transmitted, and a data frame corresponding to a TID or AC that is not mapped to either direction of the link may not be transmitted.

[0119] According to one embodiment, the TID-to-link mapping may also be applied to the acknowledgment. For example, a block ack agreement may be based on the TID-to-link mapping. Or, the TID-to-link mapping may be based on the block ack agreement. For example, a block ack agreement may exist for a TID-to-link mapped TID.

[0120] By performing TID-to-link mapping, it is possible to provide QoS services. For example, by mapping a high-priority AC and TID to a link with good channel conditions or few STAs, it is possible to transmit data of the AC and TID quickly. Or, by performing TID-to-link mapping, it is possible to help STAs of a specific link save power (or enter a doze state).

[0121] 10, an AP MLD including AP1 and AP2 may exist. A Non-AP MLD including STA1 and STA2 may also exist. A plurality of links, Link1 and Link2, may exist in the AP MLD. AP1 and STA1 may be associated with each other via Link1, and AP2 and STA2 may be associated with each other via Link2.

[0122] Thus, Link1 may include a link transmitting from AP1 to STA1 and / or a link transmitting from STA1 to AP1, and Link2 may include a link transmitting from AP2 to STA2 and / or a link transmitting from STA2 to AP2, where each link may be mapped with a TID and / or an AC.

[0123] For example, all TIDs and all ACs may be mapped to the link for transmission from AP1 to STA1 via Link1, and to the link for transmission from STA1 to AP1 via Link1. Also, only AC_VO or TID corresponding to AC_VO may be mapped to the link for transmission from STA2 to AP2 via Link2. Also, only data of the mapped TID and / or AC can be transmitted on the link. Also, data of TID or AC not mapped to the link cannot be transmitted on the link.

[0124] FIG. 11 is a diagram illustrating an example of a multi-link NAV setting operation according to an embodiment of the present invention.

[0125] The simultaneous transmit and receive (STR) operation of the MLD may be restrictive, which may be related to the frequency spacing between multiple links operating in a multi-link.

[0126] Therefore, according to an embodiment of the present invention, when the spacing between links is m MHz, simultaneous transmission or reception may be restrictive, and when the spacing between links is n MHz for n greater than m, simultaneous transmission or reception may not be restrictive. This embodiment may be for solving the problem of simultaneous transmission or reception being restrictive, and repeated explanations may be omitted. This embodiment may also be applied to MLDs that do not support STR.

[0127] According to an embodiment of the present invention, duration information may be shared between links operating as a multiple link. As an embodiment, the duration information may be TXOP duration information transmitted in a signaling field of a preamble. The signaling field may be the U-SIG field described above. Or, the signaling field may be the HE-SIG-A field described above. As yet another embodiment, the duration information may be duration information indicated by a Duration / ID field included in a MAC header. As yet another embodiment, the duration information may be duration information indicated by a Length field (L Length field) included in an L-SIG field. According to an embodiment, the duration information indicated by the U-SIG field, HE-SIG-A, or Duration / ID field may be a value indicating a TXOP duration. According to an embodiment, the duration information indicated by the L-SIG field may be a value indicating the length of a physical layer protocol data unit (PPDU) including the L-SIG field or an end of a PPDU including the L-SIG field.

[0128] Also, according to an embodiment of the present invention, it is possible to restrict transmission or channel connection to a period based on period information shared between links. The method of restricting transmission or channel connection may include setting a NAV. Alternatively, the NAV may be reset to resume transmission or channel connection. In this case, the NAV may be an intra-BSS NAV. The intra-BSS NAV may be a NAV set by an intra-BSS frame (or PPDU). That is, a STA belonging to an MLD may set a NAV based on a frame (or PPDU) directed to another STA belonging to the MLD.

[0129] According to one embodiment of the present invention, an inter-link NAV may exist. The inter-link NAV may be a NAV used by STAs of multiple links belonging to an MLD when operating with multiple links. For example, transmission may not be required on link 2 based on the inter-link NAV set based on period information received on link 1. Also, the inter-link NAV may exist or be used for an MLD that is not capable of STR. For example, when an inter-link NAV is set, the MLD that sets the inter-link NAV may not transmit or connect channels on multiple links (or all links used by the MLD).

[0130] In addition to the intra-BSS NAV, a basic NAV may be included as a type of NAV. The basic NAV may be a NAV set by an inter-BSS frame (or a PPDU), and the basic NAV may also be set by a frame (or a PPDU) that does not determine whether it is an intra-BSS or inter-BSS frame (or a PPDU).

[0131] When the inter-link NAV is used separately, it may have an advantage in a situation where the NAV setting is updated compared to when the inter-link NAV is not used. For example, a situation may occur where it is acceptable to reset the NAV set by another link. For example, when the inter-link NAV is set based on a certain frame (or PPDU), it may be acceptable to reset the set inter-link NAV because it is determined that the frame (or PPDU) is not directed to the same MLD. If there is an MLD that operates on link 1 and link 2, the NAV for link 1 may be set based on a frame received on link 1. Then, the NAV for link 1 may be updated based on a frame of link 2. If the NAV for link 1 is reset when it is no longer necessary to maintain the NAV for link 2, there is a problem in that the NAV information set based on the frame received on link 1 is lost. If the inter-link NAV is used together with the NAV for each link, the NAV for each link is maintained even if the inter-link NAV is reset, and the above problem can be solved.

[0132] Although the embodiment of the present invention has been described with respect to setting the NAV, the embodiment of the present invention is not limited to this, and can also be applied to instructing the physical layer to suspend the channel connection or to instructing the channel state to be busy. Also, the embodiment is not limited to resetting the NAV, and can also be applied to instructing the physical layer to continue the channel connection or to instructing the channel state to be idle. At this time, a primitive exchanged between the physical layer and the MAC layer may be used. Alternatively, a primitive exchanged between one STA of the MLD and another STA may be used. Alternatively, a primitive exchanged between one MAC layer of the MLD and another MAC layer may be used.

[0133] According to an embodiment of the present invention, when a STA belonging to an MLD starts receiving a PPDU, other STAs belonging to the MLD may have to stop channel access. As described above, the channel access may be stopped based on the received period information, but due to the position of the field including the period information or the time required for decoding, etc., there may be a time period from the time when the STA starts receiving the PPDU to the time when the period information is obtained. Therefore, if the STA starts transmitting by accessing the channel during this time period, the above-mentioned problem may occur. Therefore, according to an embodiment of the present invention, the STA of the MLD may suspend the channel access from the time when the other STA of the MLD starts receiving. Also, if the STA of the MLD confirms that the received frame is not destined for the other STA after the other STA of the MLD starts receiving, the STA may restart the channel access.

[0134] FIG. 12 is a diagram illustrating yet another example of a multi-link NAV setting operation according to an embodiment of the present invention.

[0135] FIG. 12 embodies the explanation regarding the specific method of the embodiment explained in FIG. 11, and the duplicated explanation may be omitted.

[0136] As described above, based on a frame or PPDU received by a STA belonging to an MLD, other STAs belonging to the same MLD can suspend or resume channel access or transmission. In the present invention, suspending channel access or transmission may include operations such as setting (updating) NAV, determining the channel as busy, or suspending CCA. Resuming channel access or transmission may include operations such as resetting NAV, canceling NAV setting, determining the channel as idle, or performing CCA. In the following, such operations can be indicated as suspending and resuming channel access. In the following, it can be described that STA1 and STA2 belong to the MLD and that STA1 and STA2 operate on Link1 and Link2, respectively. In addition, frames and PPDUs can be indicated mutually interchangeably. In addition, the NAV at this time may be intra-BSS NAV or inter-link NAV as described in FIG. 11.

[0137] According to an embodiment of the present invention, when STA1 starts receiving a frame, STA2 may suspend the channel connection. Also, when STA1 obtains duration information from the L-SIG, STA2 may maintain the suspended state of the channel connection. At this time, STA2 can determine that the suspended state of the channel connection will last until the end of the frame received by STA1. Also, when STA1 cannot certainly decode the L-SIG (if it is an invalid L-SIG), STA2 can resume the channel connection.

[0138] Also, STA1 can receive the TXOP duration and BSS color from the U-SIG of the frame received. If the received BSS color indicates intra-BSS or the BSS color is the BSS color corresponding to STA1, the channel connection can be suspended. In one embodiment, the duration for suspending the channel connection at this time may be until the end of the received frame. In this case, there is an advantage that the channel connection can be started sooner after the end of the received frame. In another embodiment, the duration for suspending the channel connection at this time may be the TXOP duration. In this case, the duration of the suspended channel connection may be updated based on the L-SIG. In this case, there is an advantage that the sequence following the received frame can be better protected.

[0139] Or, STA1 may receive TXOP duration and BSS color from the U-SIG of the received frame, but the received BSS color may indicate that it is not intra-BSS, or the BSS color may not be the BSS color corresponding to STA1. Or, STA1 may not be able to successfully decode the U-SIG. In such a case, STA2 may resume the channel connection.

[0140] Alternatively, STA2 can resume the channel connection if information obtained from the U-SIG of a frame received by STA1 indicates that the frame is a frame not received by STA1. For example, STA2 can resume the channel connection if the PHY identifier obtained from the U-SIG is an ID corresponding to a future standard or an unrecognized ID.

[0141] Although the above embodiment is described with respect to the case where U-SIG is received, the same embodiment can also be applied to the case where HE-SIG-A is received when HE PPDU is received. For example, HE-SIG-A may include TXOP duration and BSS color, and therefore the above-mentioned operation can be performed.

[0142] Also, STA2 may receive a STA-ID from the EHT-SIG of a frame received by STA1. If the received STA-ID is an indicator that STA1 should receive, for example, if the STA-ID indicates STA1, indicates a group to which STA1 belongs, or indicates broadcast, STA2 can maintain a state in which the channel connection is suspended.

[0143] Or, STA1 may receive a STA-ID from the EHT-SIG of the frame it receives. If the received STA-ID is an indicator that does not correspond to STA1, for example, if the STA-ID does not indicate an indicator that corresponds to STA1, if the STA-ID does not indicate a group to which STA1 belongs, or if the STA-ID does not indicate broadcast, STA2 can resume the channel connection. Or, STA2 can resume the channel connection even if STA1 fails to successfully decode the EHT-SIG.

[0144] Although the case of receiving EHT-SIG has been described, the same embodiment can also be applied to the case of receiving HE-SIG-B when receiving HE PPDU. For example, HE-SIG-B may include STA-ID, and therefore the above-mentioned operation can be performed.

[0145] Also, STA2 may receive the MAC header of a frame received by STA1. If the RA (receiver address) or DA (destination address) included in the received MAC header indicates a value to be received by STA1, for example, if the RA or DA indicates STA1, indicates a group to which STA1 belongs, or the STA-ID indicates broadcast, STA2 can maintain the state in which the channel connection is suspended. At this time, the duration of the suspended channel access may be based on the duration information included in the received MAC header. More specifically, the duration of the suspended channel access may be based on the duration information indicated by the Duration / ID field included in the received MAC header.

[0146] Also, STA1 may receive the MAC header of the frame it receives. If the RA or DA included in the received MAC header is an indicator that does not apply to STA1, for example, if RA or DA does not indicate an indicator that applies to STA1, does not indicate a group to which STA1 belongs, or does not indicate broadcast, STA2 can resume the channel connection. Or, STA1 may not receive all the MAC headers. For example, STA1 may fail to receive all the MPDUs included in the A-MPDU. In this case, STA2 can resume the channel connection.

[0147] The channel connection interruption and resumption described in FIG. 12 may be performed in the order of decoding as STA1 starts receiving frames (or PPDUs) and sequentially decodes them. The decoding order may be based on the PPDU format, frame format, etc. For example, the order of decoding may be L-SIG, U-SIG, EHT-SIG, and MAC header (in the case of EHT PPDU). Or, the order of decoding may be L-SIG, HE-SIG-A, and MAC header (in the case of HE SU PPDU and HE TB PPDU). Or, the order of decoding may be L-SIG, HE-SIG-A, HE-SIG-B, and MAC header (in the case of HE MU PPDU). Or, the order of decoding may be L-SIG and MAC header (in the case of 11a / g PPDU).

[0148] According to an embodiment of the present invention, the STA-ID mentioned above may be a value indicating an intended recipient of a PPDU or a resource unit (RU). The STA-ID may be included in an EHT-SIG field or an HE-SIG-B field, etc. The STA-ID may indicate a value corresponding to a single STA. For example, when multiple STAs are included in an MLD, the STA-ID may indicate a value corresponding to one of the multiple STAs. The STA-ID may be a value based on the AID or MAC address of the STA.

[0149] FIG. 13 is a diagram illustrating an example of BSS classification and operations based thereon according to an embodiment of the present invention.

[0150] According to an embodiment of the present invention, a STA can classify (or determine) a BSS based on a received frame or a received PPDU. Classifying a BSS may include an operation of classifying whether or not a received frame or a received PPDU corresponds to a BSS to which a classifying STA belongs. Or, classifying a BSS may mean an operation of classifying whether or not a received frame or a received PPDU is transmitted from a BSS to which a classifying STA belongs. Also, classifying a BSS may include an operation of classifying whether or not a received frame or a received PPDU corresponds to a BSS to which a classifying STA does not belong. Or, classifying a BSS may mean an operation of classifying whether or not a received frame or a received PPDU is transmitted from a BSS to which a classifying STA does not belong. Also, classifying a BSS may include an operation of classifying to which BSS a received frame or a received PPDU belongs. Or, classifying a BSS may mean an operation of classifying from which BSS a received frame or a received PPDU is transmitted. According to an embodiment of the present invention, a BSS to which a STA to be classified belongs may be called an intra-BSS. Or, a BSS including a BSS to which a STA to be classified belongs may be called an intra-BSS. Also, a BSS that is not an intra-BSS may be called an inter-BSS. Or, a BSS that is not an intra-BSS may be an inter-BSS or an unclassified BSS. Or, an inter-BSS may include an unclassified BSS. Also, a BSS to which a STA to be classified does not belong may be called an inter-BSS.

[0151] According to an embodiment, if a received frame or a received PPDU corresponds to an intra-BSS or is determined to have been transmitted from an intra-BSS, the received frame or the received PPDU may be referred to as an intra-BSS frame or an intra-BSS PPDU, respectively. Also, if a received frame or a received PPDU corresponds to an inter-BSS or is determined to have been transmitted from an inter-BSS, the received frame or the received PPDU may be referred to as an inter-BSS frame or an inter-BSS PPDU, respectively. Also, a PPDU including an intra-BSS frame may be an intra-BSS PPDU. Also, a PPDU including an inter-BSS frame may be an inter-BSS PPDU.

[0152] According to an embodiment of the present invention, a BSS may be classified based on one or more BSS classification conditions, for example, a BSS may be classified according to whether or not at least one of the one or more BSS classification conditions is satisfied.

[0153] The BSS classification condition may include a condition based on a BSS color. The BSS color may be an identifier for a BSS. The BSS color may be included in a preamble of a PPDU, more specifically, in a signaling field (e.g., a HE-SIG-A field, a U-SIG field, or a VHT-SIG-A field). The BSS color may be included in a TXVECTOR transmitted from a MAC layer of a sender to a PHY layer. The BSS color may be included in an RXVECTOR transmitted from a PHY layer of a receiver to a MAC layer. Parameters included in the TXVECTOR and RXVECTOR may be referred to as a TXVECTOR parameter and an RXVECTOR parameter, respectively. The BSS color may be included in a TXVECTOR parameter or an RXVECTOR parameter. The BSS color set by the AP may be notified to the STA. According to an embodiment, the BSS may be classified based on the BSS color included in the received PPDU. If the BSS color included in the PPDU received by the STA is different from the BSS color of the BSS corresponding to the STA, the received PPDU can be classified as an inter-BSS PPDU. Alternatively, if the BSS color included in the PPDU received by the STA is different from the BSS color of the BSS corresponding to the STA and its value is not 0, the received PPDU can be classified as an inter-BSS PPDU. Also, if the BSS color included in the PPDU received by the STA is the same as the BSS color of the BSS corresponding to the STA, the received PPDU can be classified as an intra-BSS PPDU.

[0154] The BSS classification condition may include a condition based on a MAC address. The MAC address may be included in a MAC header of a frame. The MAC address may include a receiver address (RA), a transmitter address (TA), a BSSID, a source address (SA), a destination address (DA), and the like. According to an embodiment, a BSS may be classified based on a MAC address included in a received frame. If a MAC address included in a received frame is different from a BSSID of a BSS corresponding to an STA, the received frame may be classified as an inter-BSS frame. More specifically, if all of the MAC addresses included in a received frame are different from the BSSID of a BSS corresponding to an STA, the received frame may be classified as an inter-BSS frame. Also, if a MAC address included in a received frame is the same as the BSSID of a BSS corresponding to an STA, the received frame may be classified as an intra-BSS frame. More specifically, if at least one of the MAC addresses included in a received frame is the same as the BSSID of a BSS corresponding to an STA, the received frame may be classified as an intra-BSS frame.

[0155] The corresponding BSS may include a BSS associated with the STA. Also, the corresponding BSS may include a BSS included in the same multiple BSSID set as the BSS associated with the STA. Also, the corresponding BSS may include a BSS included in the same co-hosted BSSID set as the BSS associated with the STA. Also, information about one or more BSSs included in the same multiple BSSID set or the same co-hosted BSSID set may be transmitted through one frame.

[0156] The BSS classification condition may include a condition based on a Partial AID field value included in the VHT PPDU. The Partial AID field may be included in a preamble of the VHT PPDU. Also, the Partial AID field may be included in a VHT-SIG-A field included in the VHT PPDU. According to an embodiment, the Partial AID field may indicate a part of the BSS color. For example, when a partial BSS color function is used, the Partial AID field may indicate a part of the BSS color. Or, when an AID assignment rule is used, the Partial AID field may indicate a part of the BSS color. The AID assignment rule may be a method of assigning an AID based on the BSS color. Also, when the Group ID field included in the VHT-SIG-A field of the VHT PPDU is a previously set value (for example, when the Group ID field is set to 63), the Partial AID field may indicate a part of the BSS color. According to one embodiment, when the Partial AID field of a received PPDU indicates a portion of a BSS color, if the received Partial AID field value is different from a portion of the BSS color corresponding to the receiving STA, the received PPDU can be classified as an inter-BSS PPDU.

[0157] Also, when the Partial AID field of the received PPDU indicates a part of the BSS color, if the value of the received Partial AID field is the same as a part of the BSS color corresponding to the receiving STA, the received PPDU can be classified as an intra-BSS PPDU. Also, in this case, the part of the BSS color can be 4 LSBs of the BSS color. According to another embodiment, the Partial AID field can indicate a part of the BSSID. For example, if the Group ID field included in the VHT-SIG-A field of the VHT PPDU is a previously set value (for example, if the Group ID field is set to 0), the Partial AID field can indicate a part of the BSSID. According to an embodiment, when the Partial AID field of the received PPDU indicates a part of the BSSID, if the value of the received Partial AID field is different from a part of the BSSID corresponding to the receiving STA, the received PPDU can be classified as an inter-BSS PPDU. Also, when the Partial AID field of the received PPDU indicates a part of the BSSID, if the received Partial AID field value is the same as a part of the BSSID corresponding to the receiving STA, the received PPDU can be classified as an intra-BSS PPDU. In this case, the part of the BSSID can be 9 MSBs of the BSSID. In addition, the Partial AID field value may be included in the TXVECTOR parameter PARTIAL_AID or the RXVECTOR parameter PARTIAL_AID. In addition, the Group ID field value may be included in the TXVECTOR parameter GROUP_ID or the RXVECTOR parameter GROUP_ID.

[0158] The BSS classification condition may include a condition for the AP to receive a PPDU of a pre-set condition. For example, the PPDU of the pre-set condition may include a downlink PPDU. According to an embodiment, the downlink PPDU may include a VHT MU PPDU. Also, the downlink PPDU may include a PPDU in which signaling indicating uplink or downlink is set to a pre-set value. The signaling indicating uplink or downlink may be included in a signaling field of a HE PPDU. Alternatively, the signaling indicating uplink or downlink may be included in a U-SIG. The U-SIG may be included in a preamble of an EHT PPDU or a post-EHT standard PPDU.

[0159] In addition, there may be cases where a PPDU cannot be classified as an intra-BSS PPDU or an inter-BSS PPDU. For example, if neither the above-mentioned conditions for classification as an intra-BSS PPDU nor the conditions for classification as an inter-BSS PPDU are satisfied, a PPDU cannot be classified as an intra-BSS PPDU or an inter-BSS PPDU.

[0160] In addition, when classifying a BSS, if the classification results based on multiple conditions do not match, it is possible to determine the final result based on the previously set conditions. For example, if the result based on the condition based on the BSS color does not match the result based on the condition based on the MAC address, the result based on the condition based on the MAC address is prioritized, or the result based on the condition based on the MAC address can be determined as the final result. Or, if both the conditions for classifying as an intra-BSS PPDU and the conditions for classifying as an inter-BSS PPDU are met, the PPDU can be classified as an intra-BSS PPDU.

[0161] According to an embodiment of the present invention, the STA may perform an operation based on the classified BSS. The operation based on the classified BSS may include an intra-PPDU power save operation. The intra-PPDU power save operation may be a power save operation based on a received PPDU. When a pre-set condition is satisfied, the intra-PPDU power save operation can be performed. The pre-set condition may include a condition for classifying a received PPDU as an intra-BSS PPDU. The pre-set condition may also include a condition for an intended receiver of a received PPDU not to be a STA that has received the PPDU. For example, if an ID or address included in a PPDU does not correspond to a STA that has received the PPDU, the intended receiver of the PPDU may not be a STA that has received the PPDU. The ID may be included in a preamble of the PPDU. For example, the ID may be a STA_ID included in a preamble of the PPDU. The STA_ID may be included in a HE MU PPDU or an EHT PPDU. The addresser may be the MAC address described above. Also, when the signaling indicating uplink or downlink included in the received PPDU indicates uplink, the intended recipient of the PPDU may not be the STA that received the PPDU. Also, when the configuration of the received PPDU is set to one that the STA that received the PPDU does not support, the intended recipient of the PPDU may not be the STA that received the PPDU. The configuration of the received PPDU may include the MCS of the PPDU, the number of spatial streams, a channel width, etc. Also, when the STA that received the PPDU does not support the configuration of the received PPDU, a PHY-RXEND.indication(UnsupportedRate) primitive may be received. Also, when the received PPDU is in a format that has already been set, the intended recipient of the PPDU may not be the STA that received the PPDU. The already set format may include a TB PPDU.The TB PPDU may include an HE TB PPDU and an EHT TB PPDU. The TB PPDU may be a PPDU transmitted as a response to a triggering frame. The triggering frame may include a trigger frame. The triggering frame may include a frame including triggering information. The triggering information may be included in a MAC header, for example, an A-control field. The triggering information or the information included in the trigger frame may include a length of the responding PPDU, an RU to be used in the response, a PHY configuration to be used in the response, a MAC configuration, etc. The intra-PPDU power saving operation may be an operation that may enter a doze state until the end of the received PPDU. As yet another embodiment, when it is determined that the STA is not the intended recipient of the received PPDU or frame, the STA may suspend reception or decoding of the PPDU or frame.

[0162] The operation based on the classified BSS may include an operation of setting (or updating) a NAV. According to an embodiment, a STA may operate one or more NAVs. Also, when a STA receives a PPDU or a frame, the STA may set a NAV corresponding to a classified BSS based on the received PPDU or the received frame. For example, an intra-BSS NAV may be a NAV corresponding to an intra-BSS PPDU. Also, a basic NAV may be a NAV corresponding to a PPDU that is not an intra-BSS PPDU. Or, a basic NAV may be a NAV corresponding to an inter-BSS PPDU. Also, when setting a NAV based on a received PPDU or a received frame, duration information included in a received PPDU or a received frame may be used. The duration information may include a TXOP. TXOP may mean a value included in a TXOP field. The TXOP field may be included in a preamble of a PPDU. For example, the TXOP field may be included in an HE-SIG-A field of a HE PPDU. Alternatively, the TXOP field may be included in the U-SIG field of the EHT PPDU or the PPDU of the post-EHT standard. Also, the duration information may be included in the MAC header. For example, the duration information may be included in the Duration / ID field included in the MAC header.

[0163] The operation based on the classified BSS may include a spatial reuse operation. Also, the operation based on the classified BSS may include a channel access operation. The spatial reuse operation may be a channel access operation. When a STA receives a PPDU or a frame, if a pre-set condition is satisfied, the spatial reuse operation can be performed. The pre-set condition may include a condition that the received PPDU or the received frame corresponds to an inter-BSS. Also, the pre-set condition may include a condition that the signal strength of the received PPDU or the received frame is smaller than a threshold. For example, the threshold may be variable. Also, the threshold may be a threshold for an OBSS PD-based spatial reuse operation. Also, the threshold may be a value equal to or greater than the CCA threshold. Also, the threshold may be a value based on the power to be transmitted. The spatial reuse operation may include an operation of transmitting a PPDU. Also, the spatial reuse operation may include an operation of resetting a PHY. For example, resetting the PHY may be issuing a PHY-CCARESET.request primitive. Spatial reuse may include not setting a NAV based on a received PPDU or a received frame. If a STA performs spatial reuse, the STA may be able to transmit a PPDU while a received PPDU or a received frame is being transmitted or received.

[0164] Referring to FIG. 13, there may be BSS A and BSS B, which may be different BSSs. Furthermore, BSS A and BSS B may correspond to inter-BSS. That is, a PPDU or frame transmitted by a STA associated with BSS A in BSS B may be classified as an inter-BSS PPDU or an inter-BSS frame. Furthermore, there may be STA1 and STA2 belonging to BSS A (or associated with an AP operating BSS A). There may be STA3 and STA4 belonging to BSS B (or associated with an AP operating BSS B). Referring to FIG. 13, STA1 may transmit a PPDU. Furthermore, the PPDU transmitted by STA1 may include information on the BSS. For example, the information on the BSS may be information for classifying the above-mentioned BSS. Furthermore, the PPDU transmitted by STA1 may include Duration information.

[0165] STA2 receives the PPDU transmitted by STA1 and can classify the BSS for this PPDU. Also, since STA2 and STA1 belong to BSS A, the PPDU received by STA2 may be classified as an intra-BSS PPDU. Also, the PPDU received by STA2 may be a UL PPDU or a PPDU for which the STA is not the intended recipient. Therefore, according to the above-mentioned embodiment, STA2 can perform intra-PPDU power saving. Referring to FIG. 13, STA2 can enter a doze state until the end of the received PPDU. Also, STA2 can set a NAV based on the Duration information included in the received PPDU. Since STA2 has classified the received PPDU as an intra-BSS PPDU, it can set an intra-BSS NAV.

[0166] STA3 receives the PPDU transmitted by STA1 and can classify the BSS for this PPDU. In addition, since STA3 and STA1 belong to BSS B and BSS A, respectively, the PPDU received by STA3 may be classified as an inter-BSS PPDU. In addition, STA3 can set the NAV based on the Duration information included in the received PPDU. Since STA3 has classified the received PPDU as an inter-BSS PPDU, it can set the basic NAV.

[0167] STA4 receives the PPDU transmitted by STA1 and can classify the BSS for this PPDU. In addition, since STA4 and STA1 belong to BSS B and BSS A, respectively, the PPDU received by STA4 may be classified as an inter-BSS PPDU. In addition, the signal strength of the PPDU received by STA4 may be smaller than a threshold. Therefore, since the PPDU received by STA4 is classified as an inter-BSS PPDU and the signal strength of the PPDU received by STA4 is smaller than a threshold, STA4 can perform spatial reuse operation. Therefore, STA4 can perform channel connection and backoff procedure, and can start transmission. For example, STA4 may be able to start transmission before the PPDU transmitted by STA1 is finished.

[0168] FIG. 14 illustrates the functionality of a station according to an embodiment of the invention.

[0169] According to an embodiment of the present invention, a station conforming to a certain WLAN standard includes the functions of the previous WLAN standard. This is for backward compatibility. For example, a station supporting a certain WLAN standard supports the functions of the previous generation WLAN standard and also supports additional new functions. For example, an HT station supports the basic functions of an OFDM PHY station. Therefore, the HT station is classified as an OFDM PHY station. Also, the HT station supports not only the functions of an OFDM PHY station but also additional functions that the OFDM PHY station does not support. A VHT station supports the basic functions of an HT station but also functions that the HT station does not support. A VHT station is classified as an HT station. Also, an HE station supports the basic functions of a VHT station but also functions that the VHT station does not support. An HE station is classified as a VHT station. Also, an EHT STA may be an HE STA. Also, an EHT station supports the basic functions of an HE station but also functions that the HE station does not support. Also, an EHT station is classified as an HE station. Also, a new WLAN standard is defined after the EHT standard. In the present invention, the standard following the EHT standard is called the NEXT standard, and the station following the NEXT standard is called the NEXT station. The NEXT station supports basic functions of the EHT station and also supports functions that the EHT station does not support. The NEXT station is classified as the EHT station.

[0170] Figure 14 is a diagram showing the relationship between stations supporting each WLAN standard. Referring to Figure 11, an EHT station is an HE station, a VHT station, an HT station, and an OFDM PHY station. Also, a NEXT station is an EHT station, a HE station, a VHT station, an HT station, and an OFDM PHY station.

[0171] FIG. 16 is a diagram illustrating UL MU operation according to an embodiment of the present invention.

[0172] In an embodiment of the present invention, an access point transmits a frame to solicit a multi-user (MU) transmission. Such a frame is called a triggering frame. At this time, one or more stations that receive the triggering frame perform uplink transmission based on the triggering frame. More specifically, one or more stations that receive the triggering frame transmit a response frame to the frame. At this time, the inter-space between the PPDU containing the triggering frame and the PPDU used for uplink transmission is SIFS. More specifically, multiple stations receive the triggering frame and simultaneously transmit immediate responses. An immediate response indicates that the interval between the previously received PPDU and the PPDU containing the response is SIFS.

[0173] The triggering frame is a type of control frame and includes trigger information. The triggering frame includes trigger information in a MAC header. In this case, the trigger information is TRS (triggered response scheduling) included in the HT Control field, Control subfield, or A-Control subfield of the MAC header. The trigger information is information that triggers transmission of a TB PPDU.

[0174] The TB PPDU is a PPDU format that includes a response frame to a triggering frame. The TB PPDU includes the HE TB PPDU and the EHT TB PPDU. The TB PPDU also includes the NEXT TB PPDU defined in the NEXT wireless LAN standard. The HE TB PPDU includes a preamble that includes L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, HE-STF, and HE-LTF in that order, followed by data and a packet extension (PE). The EHT TB PPDU and NEXT TB PPDU also include a preamble that includes L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, (EHT- / NEXT-)STF, and (EHT- / NEXT-)LTF in that order, followed by data and a packet extension (PE).

[0175] The triggering frame contains the information necessary for TB PPDU transmission. The Type subfield (B3 B2) of the MAC frame has a value of 01. b and the value of the subtype subfield (B7 B6 B5 B4) is 0010 b If so, this indicates that the MAC frame is a triggering frame.

[0176] If multiple stations responding to a trigger frame transmit TB PPDUs of different formats, it is difficult for the access point to receive the TB PPDU. Also, if the preambles of the PPDUs transmitted by multiple stations are different, it is difficult for the access point to receive the TB PPDU. In particular, if RUs in which TB PPDUs of different formats are transmitted overlap, it is difficult for the access point to receive the TB PPDU. Therefore, multiple stations transmitting responses to one triggering frame use TB PPDUs of the same format. Also, the preamble information of the TB PPDUs transmitted by multiple stations transmitting responses to one triggering frame is the same.

[0177] As described with reference to Fig. 14, an HE station transmits an HE TB PPDU, an EHT station transmits an EHT TB PPDU or an HE TB PPDU, and a NEXT station transmits a NEXT TB PPDU, an EHT TB PPDU, or an HE TB PPDU.

[0178] In the embodiment of FIG. 15, an AP transmits a trigger frame for scheduling the transmission of an HE station (HE STA) and an EHT station (EHT STA). If the trigger frame does not specify the format of the TB PPDU transmitted in response to the trigger frame, the HE station (HE STA) and the EHT station (EHT STA) or different EHT stations (EHT STAs) transmit TB PPDUs in different formats. This may result in failure in transmission of the TB PPDU and waste of a transmission opportunity. For convenience of explanation, the trigger frames defined in the HE, EHT, and NEXT standards are referred to as the HE trigger frame, the EHT trigger frame, and the NEXT trigger frame, respectively. Also, the TRSs defined in the HE, EHT, and NEXT standards are referred to as the HE TRS, the EHT TRS, and the NEXT TRS. The format of the trigger frame will be described with reference to FIG. 13.

[0179] FIG. 16 shows the format of a trigger frame and subfields included in the trigger frame according to an embodiment of the present invention.

[0180] In detail, FIG. 16(a) shows the format of a trigger frame, FIG. 16(b) shows the Common Info field of the trigger frame, and FIG. 16(c) shows the User Info field of the trigger frame. The MAC header of the trigger frame includes a Frame Control field, a Duration field, and an Address field. In this case, the Address field includes an RA field and a TA field. The trigger frame also includes a Common Info field and a User Info List field. The Common Info field includes information for all stations triggered by the trigger frame. The User Info List field also includes a User Info field. In a specific embodiment, a specific type of trigger frame does not include a User Info List field. The trigger frame also includes a Padding field and an FCS field. The Padding field serves to extend the length of the frame to ensure that a STA receiving the Tri has time to prepare a response, and is optionally present.

[0181] The Common Info field includes a Trigger Type subfield. The Trigger Type subfield identifies a trigger frame variant. The trigger frame indicates the type of the trigger frame via the value of the Trigger Type subfield. The Trigger Type subfield also determines the information contained in the Trigger Dependent Common Info subfield and the Trigger Dependent User Info subfield, and the lengths of the Trigger Dependent Common Info subfield and the Trigger Dependent User Info subfield. For example, the Trigger Type subfield is indicated by bits B0 to B3 of the Common Info field.

[0182] The Common Info field also includes a UL Length subfield. The UL Length subfield includes information about the length of the TB PPDU responding to the Trigger frame. Alternatively, the UL Length subfield includes information about the length of the frame responding to the Trigger frame. The UL Length subfield also indicates the value included in the Length subfield of the L-SIG of the TB PPDU responding to the Trigger frame. Therefore, the STA responding with the TB PPDU sets the Length subfield of the L-SIG of the TB PPDU based on the value of the UL Length subfield included in the received Trigger frame. More specifically, the STA responding with the TB PPDU sets the Length subfield of the L-SIG of the TB PPDU with the value of the UL Length subfield included in the received Trigger frame. For example, the UL Length subfield is indicated by bits B4 to B15 of the Common Info field.

[0183] The Common Info field also includes a UL BW subfield, which indicates a bandwidth (BW) value included in a signaling field, such as an HE-SIG-4 field or a U-SIG field, of a TB PPDU responding to a trigger frame, and indicates the maximum bandwidth of a TB PPDU responding to a trigger frame.

[0184] The Common Info field includes a signaling field of the TB PPDU responding to the trigger frame, such as information included in the HE-SIG-4 field or the U-SIG field.

[0185] The User Info field includes an AID12 subfield. The AID12 subfield serves to indicate the intended recipient of the User Info field including the AID12 subfield or the function of the User Info field. Thus, the AID12 subfield serves to indicate the intended recipient of the trigger frame including the AID12 subfield or the function of the trigger frame. For example, if the value of the AID12 subfield is a preset value, it indicates that the User Info field indicates a RA-RU (random access resource unit). More specifically, if the value of the AID12 subfield is 0, the User Info field indicates a RA-RU for an associated station. Also, if the value of the AID12 subfield is 2045, the User Info field indicates a RA-RU for an unassociated station. Also, it indicates that the User Info field including the AID12 subfield or the trigger frame including the AID12 subfield triggers a response, for example, the station AID corresponding to the AID (association ID) indicated by the value of the AID12 subfield. For example, the AID12 subfield indicates the AID or the 12 LSBs of the AID. A station that corresponds to the value of the AID12 subfield responds to the trigger frame with a TB PPDU. The value of the AID12 subfield ranges from 1 to 2007 (inclusive). If the AID12 subfield is a preset value, for example, 2046, it indicates that the corresponding RU is not assigned to any station. If the AID12 subfield is a preset value, for example, 4095, it indicates that padding of the trigger frame starts.

[0186] Also, information in the User Info field including the AID12 subfield is information corresponding to the station indicated by the AID12 subfield. For example, the RU Allocation subfield indicates the size and location of the RU. At this time, the value of the RU Allocation subfield of the User Info field including the AID12 subfield is information corresponding to the station indicated by the AID12 subfield. Also, the User Info field indicates the coding method (UL FEC Coding Type), modulation method (UL HE-MCS, UL DCM), and transmission power (UL Target RSSI) used in the response of the trigger frame including the User Info field.

[0187] As described above, a problem may occur depending on the PPDU format in which the TB PPDU, which is transmitted simultaneously in response to the trigger frame, is transmitted. A method of transmitting a triggering frame in this regard will be described with reference to FIG.

[0188] FIG. 17 shows information indicated by the value of the AID12 subfield of a trigger frame according to an embodiment of the present invention.

[0189] According to an embodiment of the present invention, an EHT station selectively transmits an HE TB PPDU or an EHT TB PPDU. Also, a NEXT station selectively transmits an HE TB PPDU, an EHT TB PPDU, or a NEXT TB PPDU. This allows multiple stations of WLAN standards to be scheduled in one or more frames or one PPDU. This increases the efficiency of the use of the transmission medium. For example, an HE station that does not support the EHT standard and an EHT station respond with an HE TB PPDU in one frame.

[0190] Furthermore, information for selecting the TB PPDU format is included in the trigger frame, or the TRS, or the PPDU including the trigger frame, or the PPDU including the TRS.

[0191] According to an embodiment of the present invention, information on the response TB PPDU format exists in the MAC level. According to an embodiment of the present invention, the trigger frame is classified into an HE trigger frame, an EHT trigger frame, and a NEXT trigger frame. In addition, responses triggered by the HE trigger frame, the EHT trigger frame, and the NEXT trigger frame respond with an HE TB PPDU, an EHT TB PPDU, and a NEXT TB PPDU, respectively.

[0192] Also, distinguishing between HE trigger frame, EHT trigger frame, and NEXT trigger frame means that the TB PPDU format responding to the trigger frame is distinguished into HE TB PPDU, EHT TB PPDU, and NEXT TB PPDU, respectively. That is, the TB PPDU format corresponding to the trigger frame differs depending on the trigger frame format, and the next generation trigger frame also commands the transmission of the previous generation TB PPDU. That is, the EHT trigger frame commands the transmission of the HE TB PPDU and the EHT TB PPDU at the same time. However, the HE trigger frame cannot command the transmission of the EHT TB PPDU.

[0193] In a specific embodiment, the Frame Control field of the MAC header included in the trigger frame determines whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame. For example, the Type subfield, the Subtype subfield, or the Control Frame Extension subfield of the Frame Control field of the MAC header included in the trigger frame determines whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame. For example, if the Type subfield, the Subtype subfield, or the Control Frame Extension subfield of the Frame Control field of the MAC header included in the trigger frame is a first value, the trigger frame is classified as an HE trigger frame. Also, if the Type subfield, the Subtype subfield, or the Control Frame Extension subfield of the Frame Control field of the MAC header included in the trigger frame is a second value, the trigger frame is classified as an EHT trigger frame. Also, if the Type subfield, the Subtype subfield, or the Control Frame Extension subfield of the Frame Control field of the MAC header included in the trigger frame is a third value, the trigger frame is classified as a NEXT trigger frame. The value of the Type subfield of the Frame Control field of the MAC header is 01. b and the value of the Subtype subfield is 0010 b If so, the trigger frame is classified as an HE trigger frame. The Type subfield, Subtype subfield, and Control Frame Extension subfield are limited to 2 bits, 4 bits, and 4 bits, respectively. Thus, this embodiment has the disadvantage of limiting the types that can be used in the future by using limited bit field values.

[0194] In another specific embodiment, whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame is determined according to the Common Info field included in the trigger frame. For example, if the value of the Trigger Type subfield of the Common Info field of the trigger frame is a first value, the trigger frame is classified as an HE trigger frame. If the value of the Trigger Type subfield of the Common Info field of the trigger frame is a second value, the trigger frame is classified as an EHT trigger frame. If the value of the Trigger Type subfield of the Common Info field of the trigger frame is a third value, the trigger frame is classified as a NEXT trigger frame. In particular, if the value of the Trigger Type subfield of the Common Info field of the trigger frame is 0 to 7, the trigger frame is classified as an HE trigger frame. Alternatively, if the value of the Trigger Type subfield of the Common Info field of the trigger frame is not 0 to 7, the trigger frame is classified as an EHT trigger frame or a NEXT trigger frame. Since the number of bits of the Trigger Type subfield is limited, such an embodiment has a disadvantage of limiting types that can be used in the future by using limited bit field values.

[0195] In another specific embodiment, the UL Length field included in the trigger frame determines whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame. For example, if the remainder of the UL Length field of the trigger frame divided by 3 is a first value, the trigger frame is classified as an HE trigger frame. If the remainder of the UL Length field of the trigger frame divided by 3 is a second value, the trigger frame is classified as an EHT trigger frame. If the remainder of the UL Length field of the trigger frame divided by 3 is a third value, the trigger frame is classified as a NEXT trigger frame. If the remainder of the UL Length field of the trigger frame divided by 3 is not 0, the trigger frame is classified as an HE trigger frame. If the remainder of the UL Length field of the trigger frame divided by 3 is 1, the trigger frame is classified as an HE trigger frame. If the remainder of the UL Length field of the trigger frame divided by 3 is 0, the trigger frame is classified as an EHT trigger frame or a NEXT trigger frame. In addition to the value of the UL Length field of the trigger frame, at least one of the Format Identifier, PHY Identifier, and TB PPDU format signaling of the trigger frame determines whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame.

[0196] In yet another specific embodiment, the trigger frame is determined to be an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame according to the User Info field included in the trigger frame. In detail, the trigger frame is determined to be an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame according to the value of the AID12 subfield of the User Info field of the trigger frame. For example, the trigger frame is determined to be an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame according to whether the value of the AID12 subfield of the User Info field of the trigger frame is a pre-specified value. In this case, the User Info field including the AID12 subfield indicating the type of the trigger frame is the first User Info field in the User Info field list. The User Info field including the AID12 subfield indicating the type of the trigger frame is located before the User Info field including the AID12 subfield indicating the AID of the station. As a result, the station receiving the trigger frame can determine the type of the trigger frame early. In yet another specific embodiment, the User Info field including the AID12 subfield indicating the type of trigger frame is located after the User Info field for the HE station in the User Info field list. This can prevent problems that occur when a legacy station, i.e., an HE station, cannot determine the meaning of the value of the AID12 subfield. Also, the User Info field including the AID12 subfield indicating the type of trigger frame may not include subfields other than the AID12 subfield. This is because the corresponding User Info field is for indicating the type of trigger frame, and no information other than the type of trigger frame is required. In this embodiment, the length of the User Info field varies depending on the value of the AID12 subfield.17 shows the meaning of the value of the AID12 subfield when such an embodiment is applied. If the value of the AID12 subfield is a first value, the AID12 subfield indicates that a trigger frame including the AID12 subfield triggers transmission of an EHT TB PPDU. The first value is 2047. If the value of the AID12 subfield is a second value, the AID12 subfield indicates that a trigger frame including the AID12 subfield triggers transmission of a NEXT TB PPDU. The second value is 2048.

[0197] In another specific embodiment, the station determines the format of the TB PPDU to be transmitted as a response to the trigger frame according to the position of the User Info field for triggering the station. In particular, the station determines the format of the TB PPDU to be transmitted as a response to the trigger frame based on whether the User Info field for triggering the station is located after the User Info field including the AID12 field having a pre-specified value. In this case, the station determines the format of the TB PPDU to be transmitted as a response to the trigger frame based on whether the User Info field for triggering the station is located after the User Info field including the AID12 field having a first value or after the User Info field including the AID12 field having a second value. In the embodiment of FIG. 17, if the User Info field for triggering the station is located after the User Info field including the AID12 field having 2047, the station transmits the EHT TB PPDU as a response to the trigger frame. Also, if the User Info field for triggering the station is located after the User Info field including the AID12 field having 2048, the station transmits a NEXT TB PPDU in response to the trigger frame. Also, if the User Info field for triggering the station is located after the User Info field including the AID12 field having 2047 and the User Info field including the AID12 field having 2048, the station transmits a NEXT TB PPDU in response to the trigger frame. Also, if the User Info field for triggering the station is located before the User Info field including the AID12 field having 2047 and the User Info field including the AID12 field having 2048, the station transmits a HE TB PPDU in response to the trigger frame.

[0198] Subfields of the User Info field other than the AID12 subfield determine whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame.

[0199] The Padding field of the trigger frame determines whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame. For example, whether the Padding field of the trigger frame contains a pre-specified value determines whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame.

[0200] In addition, the above-described embodiments may be applied in a combined manner, for example, factors that influence whether a trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame may be determined in a combined manner.

[0201] The above embodiment may also be used to determine the format of the TB PPDU transmitted in response to the TRS field.

[0202] FIG. 18 illustrates UL MU operation according to an embodiment of the present invention.

[0203] As described above, the trigger frame includes a TRS in the MAC frame header. The TRS is included in the HT Control field as described above. More specifically, when the HT Control field includes an A-Control field, the HT Control field includes a TRS. Also, the TRS is included in the TRS Control field. The Control List field is located contiguous to the A-Control field. In this case, the Control List field includes the TRS.

[0204] A station that is the intended recipient of a MAC frame containing TRS transmits a PPDU based on the TRS field. At this time, the TRS includes information (UL Data Symbols) on the length of the PPDU or frame that the station transmits in response to the MAC frame containing TRS. It also includes information on the power of the response transmission to the MAC frame containing TRS (AP Tx Power, UL Target RSSI), the location and size of the RU used when transmitting the response to the MAC frame containing TRS (RU Allocation), and information on the modulation method of the response transmission to the MAC frame containing TRS (UL HE-MCS).

[0205] TRS is defined for each WLAN standard. At this time, a station that receives a MAC frame including a TRS determines the format of the TB PPDU to be transmitted as a response to the TRS depending on the format of the TRS, i.e., which WLAN standard the TRS is defined in. In more detail, if a station receives a HE TRS, the station transmits a HE TB PPDU as a response to the TRS. Also, if a station receives an EHT TRS, the station transmits an EHT TB PPDU as a response to the TRS. Also, if a station receives a NEXT TRS, the station transmits a NEXT TB PPDU as a response to the TRS. At this time, the station determines which WLAN standard the TRS is defined in based on the control ID subfield of the A-Control subfield. TRS is classified into HE TRS and non-HE TRS.

[0206] The format of the TRS is determined by whether the HT Control field containing the TRS is an HE variant, an EHT variant, or a NEXT variant. If the HT Control field containing the TRS is an EHT variant, the TRS is an EHT TRS. If the HT Control field containing the TRS is a NEXT variant, the TRS is a NEXT TRS. The format of the TRS is also determined by the value of a pre-specified bit in the HT Control field containing the TRS, and whether the HT Control field is an HE variant, an EHT variant, or a NEXT variant. For example, if the values ​​of the first and second bits (B0, B1) of the HT Control field are 11, then the TRS is an EHT TRS. b If so, then the HT Control field is an HE variant. Also, the first and second bits (B0, B1) of the HT Control field and an additional bit, e.g., the 32nd bit (B31), determine whether the HT Control field is an HE variant, an EHT variant, or a NEXT variant.

[0207] In the embodiment of Figure 18, if TRS is included in the HE PPDU, the station receiving the HE PPDU transmits the HE TB PPDU as a response to the TRS. If TRS is included in the EHT PPDU, the station receiving the EHT PPDU transmits the EHT TB PPDU as a response to the TRS. If TRS is included in the NEXT PPDU, the station receiving the EHT PPDU transmits the NEXT TB PPDU as a response to the TRS.

[0208] Also, the information indicated by the subfield included in the TRS differs depending on the PPDU format in which the TRS is included. If the TRS is included in the HE PPDU, the subfield related to the MCS included in the TRS, for example, the UL HE-MCS subfield, indicates a value corresponding to the HE MCS table. If the TRS is included in the EHT PPDU, the subfield related to the MCS included in the TRS, for example, the UL HE-MCS subfield, indicates a value corresponding to the EHT MCS table. If the TRS is included in the NEXT PPDU, the subfield related to the MCS included in the TRS, for example, the UL HE-MCS subfield, indicates a value corresponding to the NEXT MCS table. Also, the information indicated by the RU Allocation subfield differs depending on the PPDU format in which the TRS is included.

[0209] FIG. 19 shows a format of a Block ACK frame according to an embodiment of the present invention.

[0210] An access point transmits ACK (acknowledgment) information for one or more MPDUs (MAC protocol data units) or one or more MSDUs (MAC service data units) using a Block ACK frame. A station that receives the Block ACK frame obtains ACK information related to one or more MPDUs or one or more MSDUs from the Block ACK frame. In this case, the MPDU or MSDU includes A (aggregated)-MPDU or A-MSDU. The ACK information is information indicating whether the MPDU or MSDU has been successfully received. The ACK information is also included in a Block ACK Bitmap subfield included in the Block ACK frame. For example, the Block ACK Bitmap subfield, which corresponds to the Block Ack Starting Sequence Control field, indicates ACK information related to a pre-specified number of MPDUs or MSDUs based on the sequence number indicated by the Block Ack Starting Sequence Control field included in the Block ACK field. The Block Ack Starting Sequence Control field includes a Fragment Number field and a Starting Sequence Number field. The Starting Sequence Number field indicates the sequence number of the first MSDU, MPDU, or A-MSDU in the Block ACK Bitmap field.

[0211] Figure 19(a) shows the format of a Block ACK frame. In Figure 19(a), the Block ACK frame includes a Frame Control field, a Duration field, an RA field, a TA field, a BA Control field, a BA Information field, and an FCS field. The Block ACK frame includes a Frame Control field, a Duration field, an RA field, a TA field, a BA Control field, a BA Information field, and an FCS field, in that order. In addition, the Frame Control field is a 2-octet field, the Duration field is a 2-octet field, the RA field is a 6-octet field, the TA field is a 6-octet field, the BA Control field is a 2-octet field, the BA Information field has a variable length, and the FCS field is a 4-octet field.

[0212] The Frame Control field indicates the type and subtype of the frame that contains the Frame Control field. A station that receives a Block ACK frame determines whether the frame is a Block ACK frame based on the Type and Subtype indicated by the Frame Control field.

[0213] The Duration field contains duration information. A station receiving a Block ACK frame sets its NAV based on the duration information. Also, a station receiving a Block ACK frame defer transmission based on the duration information.

[0214] The RA field indicates the address of the intended recipient of the Block ACK frame.

[0215] The TA field contains the sender STA address.

[0216] Figure 19(b) shows the format of the BA Control field.

[0217] In Fig. 19(b), the BA Control field includes a BA Ack Policy field, a BA Type field, a Reserved field, and a TID_INFO field. The BA Ack Policy field, the BA Type field, the Reserved field, and the TID_INFO field are located in this order in the BA Control field. The BA Control field is a 1-bit field, the BA Ack Policy field is a 1-bit field, the BA Type field is a 4-bit field, the Reserved field is a 7-bit field, and the TID_INFO field is a 4-bit field.

[0218] The BA Ack Policy subfield is decoded in the reserved field for agreements other than the HT-delayed agreement, e.g., the HT-Immediate agreement.

[0219] The BA Type subfield indicates which variant the Block ACK frame containing the BA Type subfield is. The format of the Block ACK frame differs depending on the variant of the Block ACK frame. A station that receives a Block ACK frame determines the format of the BA Information field based on the BA Type field. Also, the information indicated by the TID-INFO field differs depending on the value of the BA Type field. For example, the values ​​of the BA Type field indicate the extended compressed Block ACK variant, compressed Block ACK variant, Multi-TID Block ACK variant, GCR Block ACK variant, GLK-GCR Block ACK variant, and Multi-STA Block ACK variant, respectively. In this case, the Block ACK variant is interpreted as indicating a Block ACK frame.

[0220] FIG. 19(c) shows the BA Information field of the Compressed Block ACK variant and the BA Information field of the Multi-STA Block ACK variant. The Compressed Block ACK variant includes a Block Ack Starting Sequence Control field and a Block ACK Bitmap field. The Block Ack Starting Sequence Control field is a 2-octet field. The TID-INFO field included in the Compressed Block ACK variant indicates the TID (traffic identifier) ​​value corresponding to the MSDU and MPDU that the Compressed Block ACK variant acknowledges. The size of the Block ACK Bitmap subfield of the Compressed Block ACK variant is determined based on the Fragment Number subfield of the Block Ack Starting Sequence Control field. For example, the size of the Block ACK Bitmap subfield of the Compressed Block ACK variant is 8, 32, 64, 128, 256, or 512 octets. For example, as shown in FIG. 20, the size of the Block ACK Bitmap subfield and the maximum number of MSDUs and A-MSDUs to be ACKed are determined based on the Fragment Number subfield.

[0221] The Multi-STA Block ACK variant contains ACK information for one or more stations. The Multi-STA Block ACK variant also contains ACK information for one or more TIDs. The Multi-STA Block ACK variant contains multiple BA Information fields per AID TID Info field, depending on the combination of AID and TID.

[0222] FIG. 19(d) shows the format of the Per AID TID Info subfield. If the value of the AID11 subfield included in the Per AID TID Info subfield is not a pre-specified value, the format of the Per AID TID Info subfield as in the first embodiment of FIG. 16(d) is used. In this case, the pre-specified value is 2045. Also, if the value of the AID11 subfield included in the Per AID TID Info subfield is a pre-specified value, the format of the Per AID TID Info subfield as in the second embodiment of FIG. 19(d) is used. The AID11 subfield indicates the recipient of the Per AID TID Info subfield including the AID11 subfield, or which station the Per AID TID Info subfield corresponds to. Also, the first Per AID TID Info field in FIG. 16(d) is a Per AID TID Info field for connected stations. The second Per AID TID Info field in FIG. 16(d) is a Per AID TID Info field for unconnected stations.

[0223] The first Per AID TID Info field in FIG. 19(d) includes an AID TID Info field, a Block Ack Starting Sequence Control field, and a Block ACK Bitmap field. In addition, the AID TID Info field, the Block Ack Starting Sequence Control field, and the Block ACK Bitmap field are sequentially positioned in the Per AID TID Info field. The AID TID Info field is a two-octet field. In detail, the format of the AID TID Info field is as shown in FIG. 19(e). In addition, whether the Per AID TID Info field includes a Block Ack Starting Sequence Control field and a Block ACK Bitmap field is determined according to the value of the AID TID Info subfield. More specifically, whether the Per AID TID Info field includes a Block Ack Starting Sequence Control field and a Block ACK Bitmap field is determined according to the value of the Ack Type subfield included in the AID TID Info subfield. If the Per TID Info field includes a Block Ack Starting Sequence Control field, the Per TID Info field includes a Fragment Number subfield and a Starting Sequence Number field. Also, the degree of fragmentation, the size of the Block ACK Bitmap subfield, and the maximum number of ACKed MSDUs and A-MSDUs are determined according to the value of the Fragment Number field. The degree of fragmentation, the size of the Block ACK Bitmap subfield, and the maximum number of ACKed MSDUs and A-MSDUs are determined according to the value of the Fragment Number subfield, which will be described in detail with reference to FIG. 20.The sizes of the Block ACK Bitmap subfield are 4 octets, 8 octets, 16 octets, 32 octets, 64 octets, 128 octets, 256 octets, and 512 octets.

[0224] The second Per AID TID Info field in Figure 19(d) includes an AID TID Info field, a Reserved field, and an RA field. The AID TID Info field, the Reserved field, and the RA field are located in this order in the Per AID TID Info field. The AID TID Info field is a 2-octet field, the Reserved field is a 4-octet field, and the RA field is a 6-octet field.

[0225] The format of the AID TID Info field is as shown in the embodiment of Figure 19(e). The RA field indicates the MAC address of the recipient of the Per AID TID Info field that contains the RA field. If the recipient of the Per AID TID Info field is a non-linked station, this is because the non-linked station is not assigned an AID.

[0226] The AID TID Info subfield includes an AID11 subfield, an Ack Type subfield, and a TID subfield. The AID11 subfield, Ack Type subfield, and TID subfield are sequentially located in the AID TID Info subfield. The AID11 subfield is an 11-bit field, the Ack Type subfield is a 1-bit field, and the TID subfield is a 4-bit field. If the AID11 subfield is not a pre-specified value, it includes 11 bits of the AID of the recipient of the Per AID TID Info subfield including the AID11 subfield. The Ack Type subfield indicates whether the Per AID TID Info field includes a Block Ack Starting Sequence Control field and a Block ACK Bitmap field. If the Ack Type subfield has a value of 1, the Block Ack Starting Sequence Control field and the Block ACK Bitmap field do not exist. If the Ack Type subfield has a value of 1, the Per AID TID Info subfield including the Ack Type subfield indicates that the recipient of the Per AID TID Info subfield has successfully received all frames sent by it. In this case, the frames may be one or more frames. If the Ack Type subfield has a value of 1 and the TID subfield has a value of 0 to 7, the Per AID TID Info field indicates an ACK for a QoS Data frame or a QoS Null frame requesting an Ack frame. If the Ack Type subfield has a value of 1 and the TID subfield has a value of 14, the Per AID TID Info field indicates an ACK for the successful reception of all MPDUs in the A-MPDU, including the MPDU requesting an immediate response. If the Ack Type subfield has a value of 1 and the TID subfield has a value of 15, the Per AID TID Info field indicates an ACK for a management frame or a PS-Poll frame.The TID subfield indicates the TID corresponding to the Block ACK Bitmap. As described above, the TID subfield indicates which ACK the Per AID TID Info subfield is.

[0227] FIG. 20 illustrates a Fragment Number subfield and a Block ACK Bitmap subfield according to an embodiment of the present invention.

[0228] As described above, the size of the Block ACK Bitmap subfield and the maximum number of MSDUs and A-MSDUs to be ACKed are determined by the value of the Fragment Number subfield. The Fragment Number subfield also indicates whether fragmentation is used. In this case, the fragmentation is level 3 dynamic fragmentation. Figure 17 shows the size of the Block ACK Bitmap subfield, which corresponds to the fragment number, the maximum number of MSDUs and A-MSDUs to be ACKed, and whether fragmentation is available. The size of the Block ACK Bitmap subfield, not shown in Figure 17, is assigned to the value of the Fragment Number subfield shown as reserved in Figure 17.

[0229] FIG. 21 illustrates a Multi-STA Block ACK frame being transmitted in response to an HE TB PPDU according to an embodiment of the present invention.

[0230] The size of the Block ACK Bitmap supported by a certain standard is limited. For convenience of explanation, the Block ACK Bitmap is referred to as a bitmap. Also, the bitmap size and the bitmap length are used interchangeably. In the 802.11ax HE standard, the size of the bitmap is limited to a maximum of 256 bits.

[0231] The 802.11ax HE standard and 512-bit and 1024-bit bitmaps are supported. However, stations that support the 802.11ax HE standard but do not support standards after the 802.11ax HE standard cannot recognize the 512-bit and 1024-bit bitmaps. Therefore, the stations cannot correctly parse the Per AID TID Info field that contains the 512-bit or 1024-bit bitmap or the Per AID TID Info field that follows the field.

[0232] In Figure 21, the Multi-STA Block ACK frame includes multiple Per AID TID Info fields, and the Per AID TID Info fields have variable lengths. The length of the Per AID TID Info field is determined by the size or inclusion of the Block ACK Bitmap subfield, the inclusion of the Block Ack Starting Sequence Control subfield, the value of the Fragment Number subfield, the value of the Ack Type subfield, and the value of the AID11 subfield. In the embodiment of Figure 18, the first Per AID TID Info field (Per AID TID Info1), the second Per AID TID Info field (Per AID TID Info2), and the third Per AID TID Info field (Per AID TID Info3) are Per AID TID Info fields for the first station (STA1), the second station (STA2), and the third station (STA3), respectively. Also, the first Per AID TID Info field (Per AID TID Info1), the second Per AID TID Info field (Per AID TID Info2), and the third Per AID TID Info field (Per AID TID Info3) include 64-bit, 512-bit, and 64-bit Block ACK bitmaps, respectively. Also, the third station (STA3) is a station that does not support 512-bit and 1024-bit bitmaps. A station receiving a Multi-STA Block ACK frame determines whether the AID11 subfield included in the Per AID TID field indicates the AID of the station, and sequentially parses until it obtains a Per AID TID Info field in which the AID11 subfield indicates the AID of the station.In the embodiment of Figure 18, the third station (STA3) parses the Per AID TID Info fields in order and may not be able to parse the second Per AID TID Info field (Per AID TID Info2) correctly because the second Per AID TID Info field (Per AID TID Info2) has a length that the third station (STA3) does not support. Therefore, the third station (STA3) may not be able to receive or parse the third Per AID TID Info field (Per AID TID Info3) correctly.

[0233] A method for preventing such a problem will be described with reference to Fig. 22. In the following description, for convenience of explanation, the bitmap size is expressed as 512 bits or 1024 bits, which is a bitmap size that was not supported in the previous standard but is used in the new standard. Therefore, other numbers of bits, for example, 2048 bits or 4096 bits, may be applied instead of 512 bits or 1024 bits.

[0234] FIG. 22 illustrates UL MU operation according to an embodiment of the present invention.

[0235] As described above, the triggering frame triggers a response from one or more stations. In this case, the response is an immediate response. Therefore, the interval between the PPDU containing the trigger frame and the PPDU containing the immediate response is a pre-specified time. In this case, the pre-specified time is SIFS. In the 2.4 GHz band, SIFS is 10us, and in the 5 GHz band and 6 GHz band, SIFS is 16us. As described above, the AP transmits a trigger frame, and when a non-AP station that receives the triggering frame transmits a TB PPDU in response, it transmits an EHT TB PPDU or HE TB PPDU. In this case, the non-AP station is not only an EHT station but also an HE station. Also, the frame containing the TB PPDU requests an immediate response. In this case, the AP transmits a Multi-STA Block ACK frame.

[0236] When the AP transmits a Multi-STA Block ACK frame, which is a response to an HE TB PPDU transmitted by an HE station, the AP limits the length of the Block ACK Bitmap subfield included in the Multi-STA Block ACK frame to a value less than 512 bits. Therefore, the Multi-STA Block ACK frame does not include a 512-bit or 1024-bit Block Ack Bitmap subfield. When the AP transmits a response to a TB PPDU, the AP uses without restriction within the PPDU format supported by the station that transmitted the TB PPDU. In addition, when the AP transmits a response to a PPDU, the AP transmits a control frame, for example, a Multi-STA Block ACK frame. When the AP transmits a response frame for the TB PPDU, if the PPDU length when the AP transmits the response frame in the HE SU PPDU, HE MU PPDU, or EHT MU PPDU is smaller or equal to the PPDU length when the AP transmits the PPDU in the HE SU PPDU, HE MU PPDU, or EHT MU PPDU, the response frame is transmitted using the HE SU PPDU, HE MU PPDU, or EHT MU PPDU. Therefore, the AP transmits the Multi-STA Block ACK frame in response to the HE TB PPDU transmitted by the HE station using any PPDU supported by the intended recipient of the Multi-STA Block ACK frame. At this time, the AP uses the HE SU PPDU or HE MU PPDU. At this time, the length of the Black Ack Bitmap included in the Multi-STA Block ACK frame included in the HE SU PPDU or the HE MU PPDU is limited.

[0237] In the embodiment of FIG. 22, the AP transmits a triggering frame to a first station (non-EHT HE STA1), a second station (non-EHT HE STA2), a third station (EHT STA1), and a fourth station (EHT STA2). At this time, the first station (non-EHT HE STA1) and the second station (non-EHT HE STA2) are non-EHT stations and HE stations. Also, the third station (EHT STA1) and the fourth station (EHT STA2) are EHT stations. The triggering frame indicates the format of the TB PPDU transmitted as a response to the triggering frame as HE TB PPDU. The first station (non-EHT HE STA1), the second station (non-EHT HE STA2), the third station (EHT STA1), and the fourth station (EHT STA2) transmit the HE TB PPDU to the AP. The AP transmits a Multi-STA Block ACK frame including only a Block ACK Bitmap having a bit number of a size smaller than a pre-specified size to the first station (non-EHT HE STA1), the second station (non-EHT HE STA2), the third station (EHT STA1), and the fourth station (EHT STA2). In this case, the pre-specified size is 512 bits. The AP also transmits a Multi-STA Block ACK frame including only a Block ACK Bitmap having a bit number of a size of 256 bits or less to the first station (non-EHT HE STA1), the second station (non-EHT HE STA2), the third station (EHT STA1), and the fourth station (EHT STA2). In this case, the AP transmits a Multi-STA Block ACK frame including only a Block ACK Bitmap having a bit number of a size smaller than a pre-specified size even if it does not receive a frame from the non-EHT HE station. This is because the non-EHT HE station does not know whether the transmission is successful or not.

[0238] It is inefficient that the size of the Block ACK Bitmap is limited to the station that processes the long Block ACK Bitmap. A method for solving this problem will be described with reference to FIG.

[0239] FIG. 23 illustrates UL MU operation and the format of a Multi-STA Block ACK frame according to an embodiment of the present invention.

[0240] Even if the HE station transmits the HE TB PPDU to the AP, if the pre-specified condition is satisfied, the AP does not limit the size of the Block ACK Bitmap included in the Multi-STA Block ACK frame to a pre-specified number of bits or less. In particular, the pre-specified condition is that the Multi-STA Block ACK frame is transmitted only to the EHT station. The pre-specified condition is that the Multi-STA Block ACK frame is transmitted via the RU assigned only to the EHT station. In this case, the size of the Block ACK Bitmap included in the Multi-STA Block ACK frame is 512 bits or 1024 bits. Therefore, if the AP includes at least one non-EHT HE station among the recipients of the Multi-STA Block ACK frame, the AP sets the size of the Block ACK Bitmap of the Multi-STA Block ACK frame to a pre-specified number of bits or less. If the AP assigns at least one of the RUs to which the Multi-STA Block ACK frame is transmitted to the non-EHT HE station, the AP sets the size of the Block ACK Bitmap of the Multi-STA Block ACK frame to a pre-specified number of bits or less. The pre-specified number of bits is 256 bits.

[0241] Additionally, an HE MU PPDU or EHT MU PPDU is transmitted via one or more RUs. Additionally, each HE MU PPDU or EHT MU PPDU indicates the RU to which the PPDU is transmitted and the receiver ID (STA-ID) corresponding to the RU. The HE-SIG-B field included in the preamble of the HE MU PPDU indicates the RU to which the HE MU PPDU is transmitted and the receiver ID (STA-ID) corresponding to the RU. The EHT-SIG field included in the preamble of the EHT MU PPDU indicates the RU to which the EHT MU PPDU is transmitted and the receiver ID (STA-ID) corresponding to the RU.

[0242] The HE-SIG-B field and the EHT-SIG field include a Common field and a User Specific field. The User Specific field includes one or more User fields. A station receiving an EHT MU PPDU or an HE MU PPDU determines which RU is assigned to the User field based on the position of the Common field or the User field. The User field also includes a STA-ID field, which is a field indicating the ID of the recipient corresponding to the User field. The STA-ID field indicates the recipient of the EHT MU PPDU or the HE MU PPDU corresponding to the RU corresponding to the User field including the STA-ID field. In this case, if an RU is assigned to an individual station, the value of the STA-ID field corresponding to the RU indicates the AID of the station or a value obtained based on the AID value. In this case, the value obtained based on the AID value is the LSB (least significant bit) 11 bits of the AID. In addition, if an RU is assigned to multiple stations, the value of the STA-ID field corresponding to the RU includes a pre-specified value. The assignment of an RU to multiple stations means that a PPDU broadcasted through the RU is transmitted. In this case, the pre-specified value is 0. If the AP does not use multiple BSSIDs, the value of the STA-ID field of the RU assigned to multiple stations is set to 0. If the AP uses multiple BSSIDs, the value of the STA-ID field of the RU assigned to multiple stations is set to 0 for stations connected to the BSS of the transmitted BSSID. If the AP uses multiple BSSIDs, the value of the STA-ID field of the RU assigned to multiple stations is the BSSID index of the BSS to which the stations assigned to the RU are connected. The value of the BSSID index is one between 1 and the maximum value of the multiple BSSID set.That is, the BSSID index value ranges from 0 to the maximum BSSID index of the multiple BSSID set (or the maximum number of multiple BSSID sets minus 1, or an index value corresponding to the maximum number of BSSIDs included in the multiple BSSID set). In this case, in a multiple BSSID set, "0" is the BSSID index corresponding to the transmitted BSSID, and in a multiple BSSID set, "1" to the maximum BSSID index of the multiple BSSID set (or the maximum number of multiple BSSID sets minus 1, or an index value corresponding to the maximum number of BSSIDs included in the multiple BSSID set) is the BSSID index corresponding to the non-transmitted BSSID.

[0243] The value of the STA-ID field of an RU assigned to multiple stations is 2047. Also, the value of the STA-ID field of an RU assigned to a station connected to a BSS with a non-transmitted BSSID is 2047. In this case, the TA field of the frame transmitted through the RU indicates the transmitted BSSID. If the AP is the receiver of an EHT MU PPDU or HE MU PPDU, the STA-ID field indicates the sender of the HE MU PPDU or ETH MU PPDU. Also, the value of the STA-ID field of an RU assigned to an unconnected station is 2045.

[0244] The value of the STA-ID field is the STA-ID value of the TXVECTOR or RXVECTOR parameter.

[0245] The size of the Block ACK Bitmap of a Multi-STA Block ACK frame transmitted through an RU assigned to one ETH station or a Multi-STA Block ACK frame transmitted to one EHT station is not limited to a value smaller than a pre-specified value. In this case, the Multi-STA Block ACK frame includes a 512-bit Block ACK Bitmap or a 1024-bit Block ACK Bitmap. In this embodiment, the Multi-STA Block ACK frame is transmitted through an HE MU PPDU, HE SU PPDU, EHT MU PPDU, or non-HT PPDU.

[0246] If a Multi-STA Block ACK frame is transmitted through an RU assigned to one ETH station, the size of the Block ACK Bitmap of the Multi-STA Block ACK frame is not limited to a value smaller than a pre-specified value. If the RA field of the Multi-STA Block ACK frame indicates the MAC address of an individual ETH station, the size of the Block ACK Bitmap of the Multi-STA Block ACK frame is not limited to a value smaller than a pre-specified value. In such an embodiment, the Multi-STA Block ACK frame includes a 512-bit Block ACK Bitmap or a 1024-bit Block ACK Bitmap. If a Multi-STA Block ACK frame is transmitted in response to an HE TB PPDU transmitted by at least one non-EHT HE station, and the Multi-STA Block ACK frame is not transmitted through an RU assigned to one EHT station, but the RA field of the Multi-STA Block ACK frame does not indicate the MAC address of an individual EHT station, the size of the Block ACK Bitmap of the Multi-STA Block ACK frame is limited to a value smaller than a pre-specified value. In this case, the Multi-STA Block ACK frame is not permitted to include a 512-bit Block ACK Bitmap or a 1024-bit Block ACK Bitmap.

[0247] That is, if at least one STA transmitting the PPDU in response to the trigger frame among one or more STAs includes not only an EHT STA but also a legacy HE STA, the size of the Block ACK Bitmap, which is Ack information for each of at least one STA included in the Multi-STA Block ACK frame, which is a response frame for the PPDU indicated by the triggering frame, is limited to a specific size (e.g., 256 bits) or less. That is, 512 bits and 1024 bits cannot be used as the size of the Block ACK Bitmap.

[0248] However, even if the at least one STA that transmits the PPDU in response to the trigger frame among the one or more STAs includes an HE STA, which is a legacy STA, the size of the Ack information is not limited to a specific size or less if the multi-STA Block ACK frame is transmitted through a resource unit (RU) individually assigned to the STA by the AP. In other words, even if the AP receives an HE TB PPDU from a STA, the size of the ACK information is not limited if the AP transmits the multi-STA Block ACK frame through an RU individually assigned to the EHT STA. In other words, if the AP transmits the multi-STA Block ACK frame through an RU assigned to the EHT STA as dedicated, the multi-STA Block ACK frame is received and interpreted only by the EHT STA, so there is no need to limit the size of the Block ACK Bitmap for the HE STA.

[0249] In the embodiment of FIG. 23, the AP transmits a triggering frame to a first station (non-EHT HE STA1), a second station (non-EHT HE STA2), a third station (EHT STA1), and a fourth station (EHT STA2). At this time, the first station (non-EHT HE STA1) and the second station (non-EHT HE STA2) are non-EHT stations and HE stations. Also, the third station (EHT STA1) and the fourth station (EHT STA2) are EHT stations. The triggering frame indicates the format of the TB PPDU transmitted as a response to the triggering frame as HE TB PPDU. The first station (non-EHT HE STA1), the second station (non-EHT HE STA2), the third station (EHT STA1), and the fourth station (EHT STA2) transmit the HE TB PPDU to the AP. The AP transmits a Multi-STA Block ACK frame for the first station (non-EHT HE STA1), the second station (non-EHT HE STA2), and the fourth station (EHT STA2) through the first RU (RU1). At this time, the stations assigned to the first RU (RU1) include the first station (non-EHT HE STA1) and the second station (non-EHT HE STA2), which are non-EHT stations. Therefore, the Multi-STA Block ACK frame includes only a Block ACK Bitmap with a size smaller than 512 bits. In addition, the AP transmits a Multi-STA Block ACK frame for the third station (EHT STA1) through the second RU (RU2). The second RU (RU2) is an RU assigned only to the third station (EHT STA1), which is an EHT station. Therefore, the size of the Block ACK Bitmap included in the Multi-STA Block ACK frame transmitted through the second RU (RU2) is not limited to a size smaller than 512 bits.

[0250] FIG. 24 illustrates UL MU operation and the format of a Multi-STA Block ACK frame according to another embodiment of the present invention.

[0251] When the AP receives an HE TB PPDU from at least one HE station and transmits a Multi-STA Block ACK frame in response to the frame included in the HE TB PPDU, the AP determines whether to limit the size of the Block ACK Bitmap in the Multi-STA Block ACK frame to a value smaller than a pre-specified size based on pre-specified conditions. If all pre-specified conditions are satisfied, the AP does not limit the size of the Block ACK Bitmap in the Multi-STA Block ACK frame to a value smaller than a pre-specified size. Even if the Multi-STA Block ACK frame is transmitted in an RU allocated for a broadcast frame, if all pre-specified conditions are satisfied, the AP does not limit the size of the Block ACK Bitmap in the Multi-STA Block ACK frame to a value smaller than a pre-specified size. In this case, the pre-specified conditions include the case where the Multi-STA Block ACK frame is transmitted only to an EHT station. Therefore, even if the Multi-STA Block ACK frame is transmitted via a broadcast RU, if it is transmitted only to an ETH station, the AP does not limit the size of the Block ACK Bitmap in the Multi-STA Block ACK frame to a value smaller than a pre-specified size. Even if the Multi-STA Block ACK frame is transmitted via a broadcast RU, if it is transmitted only to ETH stations, the AP does not limit the size of the Multi-STA Block ACK frame to a value smaller than a pre-specified size.

[0252] In addition, the pre-specified conditions include a case where a PPDU including a Multi-STA Block ACK frame is transmitted from different RUs assigned to each of all HE stations that triggered the transmission of the TB PPDU transmitted immediately before the Multi-STA Block ACK frame.

[0253] This embodiment assumes that the AP transmits a Multi-STA Block ACK frame to at least one non-EHT HE STA.

[0254] In addition, in the above-mentioned embodiment, not limiting the size of the Block ACK Bitmap of the Multi-STA Block ACK frame to a value smaller than a pre-specified size indicates that the Multi-STA Block ACK frame includes a Block ACK Bitmap of 512 bits or 1024 bits.

[0255] In the embodiment of FIG. 24, the AP transmits a triggering frame to a first station (non-EHT HE STA1), a second station (non-EHT HE STA2), a third station (EHT STA1), and a fourth station (EHT STA2). At this time, the first station (non-EHT HE STA1) and the second station (non-EHT HE STA2) are non-EHT stations and HE stations. Also, the third station (EHT STA1) and the fourth station (EHT STA2) are EHT stations. The triggering frame indicates the format of the TB PPDU transmitted as a response to the triggering frame as HE TB PPDU. The first station (non-EHT HE STA1), the second station (non-EHT HE STA2), the third station (EHT STA1), and the fourth station (EHT STA2) transmit the HE TB PPDU to the AP. The AP transmits a Multi-STA Block ACK frame to the first station (non-EHT HE STA1) through the first RU (RU1), the second station (non-EHT HE STA2) through the second RU (RU2), and the third station (EHT STA3) and fourth station (EHT STA2) through the third RU (RU3). At this time, the stations assigned to the first RU (RU1) include the first station (non-EHT HE STA1), which is a non-EHT station, and the stations assigned to the second RU (RU2) include the second station (non-EHT HE STA2). Therefore, the Multi-STA Block ACK frame transmitted through each of the first RU (RU1) and the second RU (RU2) includes only a Block ACK Bitmap of a size smaller than 512 bits. The third RU (RU3) is a broadcast RU, but all stations assigned to the third RU (RU3) are ETH stations. Therefore, the size of the Block ACK Bitmap included in the Multi-STA Block ACK frame transmitted via the third RU (RU3) is not limited to having a size smaller than 512 bits.

[0256] If the above-mentioned pre-specified conditions are not satisfied, there is no RU individually assigned to the non-EHT HE station to transmit the Multi-STA Block ACK frame. Therefore, the non-EHT HE station receives the Multi-STA Block ACK frame through the RU assigned to the multiple stations. In this case, if the size of the Block ACK Bitmap of the Multi-STA Block ACK frame is 512 bits or more, the non-EHT HE station may not be able to parse the Multi-STA Block ACK frame correctly. In addition, if the AP cannot receive the HE TB PPDU transmitted by the non-EHT HE station, the intended recipient of the Multi-STA Block ACK frame does not include the non-EHT HE station. In this case, if the size of the Block ACK Bitmap of the Multi-STA Block ACK frame is 512 bits or more, the non-EHT HE station may not be able to parse the Multi-STA Block ACK frame correctly.

[0257] To summarize the embodiments described in Figures 23 and 24, if the AP transmits a Multi-STA Block ACK frame as a response to a TB PPDU transmitted only by an EHT station or a TB PPDU transmitted by a triggering frame triggering an EHT station, the AP does not limit the size of the Multi-STA Block ACK frame to a value smaller than a pre-specified size. Also, if the AP transmits a Multi-STA Block ACK frame including a response to a frame including an HE TB PPDU transmitted by at least one non-EHT HE station, the AP limits the size of the Multi-STA Block ACK frame to a value smaller than a pre-specified size. If the AP transmits a Multi-STA Block ACK frame in an RU individually addressed to an EHT station, the AP does not limit the size of the Multi-STA Block ACK frame to a value smaller than a pre-specified size. Also, if the Multi-STA Block ACK frame is transmitted in an RU allocated only to the EHT station, and the PPDU including the Multi-STA Block ACK frame is transmitted in an RU allocated individually to all non-EHT HE stations that were triggered by the triggering frame that triggered all TB PPDUs transmitted simultaneously with the TB PPDU that triggered the transmission of the Multi-STA Block ACK frame, the AP does not limit the size of the Multi-STA Block ACK frame to a value smaller than the pre-specified size. Also, if the Multi-STA Block ACK frame is transmitted in an RU allocated only to the EHT station, and the PPDU including the Multi-STA Block ACK frame is transmitted in an RU allocated individually to all non-EHT HE stations that were triggered by the PPDU that triggered the TB PPDU that triggered the transmission of the Multi-STA Block ACK frame, the AP does not limit the size of the Multi-STA Block ACK frame to a value smaller than the pre-specified size.

[0258] Alternatively, in the case of a Multi-STA BlockAck frame included in a broadcast RU for EHT STAs only, if individually addressed RUs for all non-EHT HE STAs triggered by a PPDU that solicited a frame that solicited the Multi-STA BlockAck frame are included in the PPDU that includes the broadcast RU, the size of the bitmap is not restrictive.

[0259] The AP has been described in conjunction with Figures 20 to 24 for configuring and transmitting a Multi-STA Block ACK frame. A station receives and parses the Multi-STA Block ACK frame according to the above-described configuration and transmission method of the Multi-STA Block ACK frame. In addition, the station determines the number of MPDUs that can be aggregated into an A-MPDU based on the size of the Block ACK Bitmap of the Multi-STA Block ACK frame.

[0260] FIG. 25 illustrates transmitting a management frame according to an embodiment of the present invention.

[0261] A management frame is included in an A(aggregate)-MPDU. If the type field included in the Frame Control field is a pre-specified value, the Type field indicates that the frame containing the Type field is a management frame. The pre-specified value is 00. b It is.

[0262] The management frames include an Association Request frame, an Association Response frame, a Reassociation Request frame, a Reassociation Response frame, a Probe Request frame, a Probe Response frame, a Timing Advertisement frame, a Beacon frame, an ATIM frame, a Disassociation frame, an Authentication frame, a Deauthentication frame, an Action frame, and an Action No Ack frame.

[0263] The management frame may be included in an ack-enabled single-TID A-MPDU or an ack-enabled multi-TID A-MPDU. An ack-enabled single-TID A-MPDU is an A-MPDU that contains at least two A-MPDU subframes, where the traffic identifiers (TIDs) differ and where only one of the A-MPDU subframes includes a tagged MPDU that solicits the acknowledgment context. An Ack-enabled multi-TID A-MPDU is an A-MPDU where at least one tagged MPDU that solicits acknowledgment context is aggregated in the A-MPDU, and MPDUs from more than one TID that solicit Ack acknowledgment or Block Ack acknowledgment context are aggregated in the A-MPDU.

[0264] An Ack-enabled A-MPDU is an A-MPDU that induces an ACK frame or induces an ACK context of a Multi-STA Block ACK frame. In addition, capability signaling is performed regarding whether to receive an ack-enabled A-MPDU. In this case, the capability signaling is performed via the HE Capabilities element. More specifically, the capability signaling is performed via the Ack-Enabled Aggregation Support subfield included in the HE MAC Capabilities Information field.

[0265] Management frames are considered to have a TID of 15. Specifically, management frames are treated as single-TID frames. Management frames are frames that trigger ACKs. Also, management frames are included in ack-enabled single-TID A-MPDUs or ack-enabled multi-TID A-MPDUs.

[0266] In this case, the management frame is a frame that solicits an acknowledgment. Also, in this case, the management frame may be included in an ack-enabled single-TID A-MPDU or an ack-enabled multi-TID A-MPDU.

[0267] An ACK frame is transmitted in response to the management frame. The AP also transmits a response to the management frame using the Per AID TID field included in the Multi-STA Block ACK frame. In this case, the AP sets the value of the TID field in the Per AID TID field to 15.

[0268] In the embodiment of Figure 25, the station transmits an A-MPDU including a management frame. The AP transmits an ACK for the management frame using a Multi-STA Block ACK frame. At that time, the AP sets the value of the TID field of the Per AID TID field, which corresponds to the response to the management frame, to 15.

[0269] FIG. 26 illustrates a method of transmitting a management frame when TID-to-link mapping is applied according to an embodiment of the present invention.

[0270] As mentioned above, TID-to-link mapping is applied in multi-link operation. A specific TID is mapped to a link, and each link transmits frames corresponding to the TID mapped to the link, and does not allow transmission of frames corresponding to TIDs not mapped to the link. A link to which at least one TID is mapped is called an enabled link, and a link to which no TID is mapped is called a disabled link.

[0271] As mentioned above, management frames are transmitted on any link. Also, management frames are single TID frames. Also, management frames are treated as frames with TID 15. Therefore, there is a risk of conflict between TID-to-link mapping and the handling of management frames.

[0272] In a specific embodiment, the management frame is mapped to all links regardless of the TID value. In another specific embodiment, the management frame is mapped to all links regardless of whether the TID of the management frame is 15. In this case, the management frame is transmitted on all links. All links are limited to only activated links. In this case, the management frame is included in an ack-enabled single-TID A-MPDU or an ack-enabled multi-TID A-MPDU. In addition, the management frame is a frame that induces an ACK.

[0273] In another embodiment, management frames are transmitted regardless of the TID-to-link mapping, and the TID-to-link mapping is only applied to data frames or QoS data frames.

[0274] In the embodiment of FIG. 26, TID-to-link mapping is performed, and TIDs 0 to 7 are mapped to the first link (Link 1). At this time, the management frame is transmitted on the first link (Link 1). Specifically, an ack-enabled single-TID A-MPDU or an ack-enabled multi-TID A-MPDU including a management frame is transmitted on the first link (Link 1). More specifically, an ack-enabled single-TID A-MPDU or an ack-enabled multi-TID A-MPDU including a management frame that induces an ACK is transmitted on the first link (Link 1). That is, only in the TID-to-link mapping, the management frame is not treated as a single TID frame, and the TID value of the management frame is not treated as 15.

[0275] FIG. 27 illustrates a method of transmitting a management frame when TID-to-link mapping is applied according to another embodiment of the present invention.

[0276] In another specific embodiment, TID-to-link mapping is applied to the management frame. That is, the TID corresponding to the management frame is mapped to a link. If the TID corresponding to the management frame is mapped to a link, the management frame is transmitted on the corresponding link. If the TID corresponding to the management frame is not mapped to a link, the management frame is not transmitted on the corresponding link. The TID corresponding to the management frame is 15. In this case, the management frame is included in an ack-enabled single-TID A-MPDU or an ack-enabled multi-TID A-MPDU. The management frame also induces an ACK.

[0277] In the embodiment of FIG. 27, TID-to-link mapping is performed. At this time, TIDs 0 to 7 are mapped to the first link (Link 1), and the management frame is mapped to the second link (Link 2). At this time, the management frame cannot be transmitted on the first link (Link 1). Therefore, the management frame is transmitted on the second link (Link 2). More specifically, an ack-enabled single-TID A-MPDU or an ack-enabled multi-TID A-MPDU including a management frame is transmitted on the second link (Link 2). More specifically, an ack-enabled single-TID A-MPDU or an ack-enabled multi-TID A-MPDU including a management frame that induces an ACK is transmitted on the second link (Link 2).

[0278] In the above embodiment, the TID value of the management frame is described as 15, but other values ​​may be applied to the TID value of the management frame.

[0279] For the TID corresponding to the management frame, the TID-to-link mapping for uplink transmission and the TID-to-link mapping for downlink transmission are not performed independently. Therefore, if the management frame is mapped to a link, the uplink transmission of the management frame and the downlink transmission of the management frame are mapped to the corresponding link. As described above, the TID-to-link mapping of the data frame or the QoS data frame, the TID-to-link mapping of the uplink transmission and the TID-to-link mapping of the downlink transmission are performed independently. In this way, the TID-to-link mapping method of the data frame or the QoS data frame and the TID-to-link mapping method of the management frame are different.

[0280] The elements transmitted during the negotiation process of the TID-to-link mapping signal the TID-to-link mapping for uplink transmission and the TID-to-link mapping for downlink transmission, respectively. In this case, the value of the TID-to-link mapping for uplink transmission of the management frame and the value of the TID-to-link mapping for downlink transmission of the management frame are set to the same value. In another specific embodiment, the TID-to-link mapping for uplink transmission of the management frame and the TID-to-link mapping for downlink transmission are not separately signaled. In yet another specific embodiment, the TID-to-link mapping for the management frame is implicitly signaled, not explicitly signaled. In yet another specific embodiment, if the TID-to-link mapping for any one transmission direction of the management frame is signaled, the TID-to-link mapping for the remaining transmission directions is also applied.

[0281] The TID-to-link mapping for management frames is only applied to the specific management frame. For example, the TID-to-link mapping is not applied to beacon frames. In this case, the beacon frame is transmitted through any link regardless of the TID-to-link mapping. Also, the specific frame is an action frame.

[0282] Before multilink setup, no TID-to-link mapping is applied to management frames, after multilink setup, TID-to-link mapping is applied to management frames. Before multilink setup, management frames are transmitted on any link. After multilink setup, management frames are transmitted only on the links to which they are mapped.

[0283] FIG. 28 is a diagram illustrating a management frame and channel width signaling according to one embodiment of the present invention.

[0284] Referring to FIG. 28, a management frame transmitted by an AP to a STA includes an operation element for each STA.

[0285] In detail, according to an embodiment of the present invention, a management frame includes a Capabilities element. The management frame also includes an operation element. The management frame includes a Beacon frame, an Association Response frame, a Reassociation Response frame, a Probe Response frame, an Association Request frame, a Reassociation Request frame, a Probe Request frame, etc. The Capabilities element also includes information on capabilities for each standard. For example, the Capabilities element includes an HT Capabilities element, a VHT Capabilities element, a HE Capabilities element, an EHT Capabilities element, etc. The operation element includes information on operation for each standard. For example, the operation element includes an HT operation element, a VHT operation element, a HE operation element, an EHT operation element, etc.

[0286] According to an embodiment, the Capabilities element includes signaling indicating a channel width set supported by the STA transmitting the Capabilities element. The signaling indicating the channel width is a Supported Channel Width Set subfield. The Supported Channel Width Set subfield included in the HT Capabilities element is 1) 20 MHz, or 2) 20 or 40 MHz channel width. Also, the Supported Channel Width Set subfield included in the HT Capabilities element is 1-bit. The Supported Channel Width Set subfield included in the VHT Capabilities element or the HE Capabilities element indicates which combination of channel widths is supported among 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 80+80 MHz channel widths. The Supported Channel Width Set subfield included in the VHT Capabilities element is 2-bit. The Supported Channel Width Set subfield included in the HE Capabilities element is 7-bit. The Supported Channel Width Set subfield included in the EHT Capabilities element indicates which combination of channel widths is supported among 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz channel widths.

[0287] An operating element indicates channel information operated by a STA transmitting the operating element. For example, an operating element indicates a channel width operated by a STA transmitting the operating element. Signaling indicating the channel width included in the operating element is a Channel Width subfield. Also, the operating element indicates a channel location operated by a STA transmitting the operating element. Signaling indicating the channel location included in the operating element includes a Primary Channel subfield, a Channel Center Frequency Segment 0 subfield, a Channel Center Frequency Segment 1 subfield, and a Secondary Channel Offset field. The Primary Channel subfield indicates the location of the primary channel. The Channel Center Frequency Segment 0 subfield and the Channel Center Frequency Segment 1 subfield indicate the center frequency of the operating subchannel. The Secondary Channel Offset field indicates the location of the secondary channel.

[0288] Also, the channel width in which the BSS operates is determined based on at least one of the signaling indicating the channel width and the signaling indicating the channel position included in the operating element. Also, the channel position in which the BSS operates is determined based on at least one of the signaling indicating the channel width and the signaling indicating the channel position included in the operating element. Also, the channel width or the channel position can be determined based on an operating element corresponding to one or more standards. Although it has been described that the channel width and the channel position are determined based on the operating element, this is the operation of the STA receiving the operating element. For example, the STA receiving the operating element is a non-AP STA. Conversely, the STA transmitting the operating element signals the channel width and signals the channel position based on the operating element as described above. For example, the STA transmitting the operating element is an AP. According to an embodiment of the present invention, the channel width indicated to the HT STA is one of 20 and 40 MHz channel widths. According to an embodiment of the present invention, the channel width indicated to the VHT STA is one of 20, 40, 80, 160, and 80+80 MHz channel widths. According to an embodiment of the present invention, the channel width specified to the HE STA is one of 20, 40, 80, 160, and 80+80 MHz channel widths. According to an embodiment of the present invention, the channel width specified to the EHT STA is one of 20, 40, 80, 160, and 320 MHz channel widths. Or, according to an embodiment of the present invention, the channel width specified to the EHT STA is one of 0, 40, 80, 160, 80+80, and 320 MHz channel widths.

[0289] Referring to FIG. 28(a), the management frame includes the above-mentioned Capabilties element or operation element. According to one embodiment, the management frame includes Capabilties element or operation element corresponding to one or more standards, thereby allowing STAs of previous standards to operate based on the management frame. This also reduces the overhead of information corresponding to STAs of new standards. Referring to FIG. 28(a), the management frame transmitted by the EHT AP includes an HT Capabilities element, an HT operation element, a VHT Capabilities element, a VHT operation element, a HE Capabilities element, an EHT Capabilities element, and an EHT operation element.

[0290] 28(b), the HE operation element includes a 6GHz Operation Information field. The 6GHz Operation Information field is signaling indicating channel information. Alternatively, the 6GHz Operation Information field includes signaling indicating channel information. Alternatively, the 6GHz Operation Information field indicates channel information for a BSS in the 6GHz band.

[0291] Referring to FIG. 28(c), the 6GHz Operation Information field includes a primary channel subfield, a control field, a Channel Center Frequency Segment 0 subfield, a Channel Center Frequency Segment 1 subfield, and a Minimum Rate subfield. Each of the above fields has a size of 1-octet. The Primary Channel subfield included in the 6GHz Operation Information field indicates the channel number of the primary channel in the 6GHz band. The Channel Center Frequency Segment 0 subfield indicates the center frequency index of the entire operation channel when operating with a 20, 40, or 80MHz channel width. The Channel Center Frequency Segment 0 subfield indicates the center frequency index of the primary 80MHz channel when operating with a 160 or 80+80MHz channel width. The Channel Center Frequency Segment 1 subfield indicates the center frequency index of the entire operation channel when operating with a 20, 40, 80, or 160MHz channel width. The Channel Center Frequency Segment 1 subfield indicates the center frequency index of the secondary 80 MHz channel when operating with 80+80 MHz channel width.

[0292] The control field included in the 6GHz Operation Information field has a format as shown in FIG. 28(d). Referring to FIG. 28(d), the Control field includes Channel Width, Duplicate Beacon, Regulatory Info, and Reserved subfields. Each of the subfields mentioned above has a size of 2, 1, 3, and 2-bit, respectively. That is, the 6GHz Operation Information field includes a Channel Width subfield. In this case, the channel width indicated by the Channel Width subfield is 20, 40, 80, or 160 / 80+80MHz. More specifically, if the Channel Width subfield is 0, it indicates a 20MHz channel width, if it is 1, it indicates a 40MHz channel width, if it is 2, it indicates an 80MHz channel width, and if it is 3, it indicates a 160 or 80+80MHz channel width.

[0293] FIG. 29 is a diagram illustrating setting the width of a BSS operating channel according to one embodiment of the present invention.

[0294] Referring to FIG. 29, the AP sets different BSS operating channels for each STA depending on whether the STA supports the BSS.

[0295] In detail, according to an embodiment of the present invention, the AP informs the non-EHT STA and the EHT STA of different BSS operating channels. For example, the AP informs the non-EHT STA and the EHT STA of different BSS operating channel widths. This can be limited to an example operating in the 6 GHz band. The non-EHT STA includes the HE STA. In the embodiment of the present invention, the BSS operating channel informed to the non-EHT STA is called the non-EHT BSS operating channel. Also, the BSS operating channel informed to the EHT STA is called the EHT BSS operating channel. In the present invention, the EHT BSS operating channel and the non-EHT BSS operating channel are different because the EHT BSS operating channel is a channel that cannot be supported by the non-EHT BSS or the non-EHT STA. Or, in the present invention, the EHT BSS operating channel and the non-EHT BSS operating channel are different because the EHT BSS operating channel includes a disallowed channel. More specifically, the EHT BSS operating channel is different from the non-EHT BSS operating channel because the EHT BSS operating channel includes at least one disabled 20 MHz channel. In this case, the BSS operating channel means the BSS operating channel width.

[0296] In other words, the AP transmits the BSS operating channel by including information on the BSS operating channel in each STA operating element included in the management frame. In this case, the AP sets a different BSS operating channel for each STA when setting the BSS operating channel for each STA. For example, when the AP sets an operating channel for the EHT STA and an operating channel for the HE STA, the set operating channel for the EHT STA and the set operating channel for the HE STA are different from each other. In particular, the EHT STA can operate even if the BSS operating channel includes a punctured subchannel (or an unavailable subchannel or a deactivated subchannel, etc.). In addition, the EHT STA can operate even if the BSS operating channel is non-contiguous or is allocated 160 MHz or more. However, the HE STA cannot operate if the set BSS operating channel includes a punctured subchannel, the BSS operating channel is a non-contiguous channel, or is 160 MHz or more.

[0297] Therefore, when the AP sets up a BSS operating channel for the STA via each operating element included in the management frame for the STA, the AP sets up the EHT STA and the HE STA differently. That is, if the EHT BSS operating channel includes at least one punctured subchannel and / or the EHT BSS operating channel has a channel width not supported by the HE BSS, the AP sets up a BSS operating channel for the HE STA via the HE operating element different from the BSS operating channel for the EHT STA.

[0298] In this case, the BSS serving channels for the HE STAs are set up contiguously within the maximum bandwidth that the primary channel is included in.

[0299] Therefore, the HE operation element (first operation element) for the HE STA and the EHT operation element (second operation element) for the EHT STA included in the management frame set the BSS operation channel to each STA differently. In this case, each STA transmits a PPDU to the AP according to the set BSS operation channel. Also, whether a channel is punctured or disallowed is determined by the AP. For example, if the AP observes a certain channel and determines that it is difficult to operate, it sets the channel as disallowed. Or, whether a channel is disallowed is based on a database. For example, if a certain channel is disallowed based on the database, the AP sets the channel as a disallowed channel. According to one embodiment, the disallowed channel is indicated by the EHT operation element or the EHT Capabilities element. For example, the unit for signaling the disallowed channel is 20 MHz bandwidth. For example, the EHT operation element signals whether each 20 MHz channel constituting the BSS operation channel is disallowed or not. In addition, the AP and non-AP STAs of a BSS in which a disabled channel is configured do not transmit PPDUs including the disabled channel.

[0300] According to an embodiment, the non-EHT BSS operating channel is a BSS operating channel notified based on an EHT operation element or an element other than an EHT Capabilities element. For example, the non-EHT BSS operating channel is a non-EHT BSS operating channel notified based on an HE operation element or an HE Capabilities element. More specifically, the non-EHT BSS operating channel is a non-EHT BSS operating channel notified based on a 6GHz Operation Information field included in the HE operation element. The non-EHT BSS operating channel width may have values ​​of 20, 40, 80, or 160 MHz. Alternatively, the non-EHT BSS operating channel width may have values ​​of 20, 40, 80, 160, or 80+80 MHz.

[0301] Also, the EHT BSS operating channel is a BSS operating channel notified based on an element including an EHT operation element or an EHT Capabilities element. More specifically, the EHT BSS operating channel is an EHT BSS operating channel notified based on a 6GHz Operation Information field included in the EHT operation element. Or, the EHT BSS operating channel is an EHT BSS operating channel notified based on a channel width subfield included in the EHT operation element. Also, the EHT operation element includes information on disallowed channels. Values ​​indicated as the EHT BSS operating channel width are 20, 40, 80, 160, and 320 MHz. Or, values ​​indicated as the Non-EHT BSS operating channel width are 20, 40, 80, 160, 80+80, 320, and 160+160 MHz.

[0302] According to an embodiment of the present invention, the non-EHT BSS operating channel width is the widest width obtained by excluding disallowed channels from the EHT operating channel width. According to an embodiment of the present invention, the BSS operating channel width included in the HE operating element is the widest width obtained by excluding disallowed channels from the EHT operating channel width. Alternatively, the BSS operating channel width included in the HE operating element is the widest width obtained by excluding disallowed channels from channel widths signaled based on the EHT operating element. In this case, more specifically, the disallowed channels refer to disabled 20 MHz channels.

[0303] Referring to FIG. 29, there are four 80 MHz channels in succession. For example, there are 80 MHz channel 1, 80 MHz channel 2, 80 MHz channel 3, and 80 MHz channel 4. Also, 80 MHz channel 1 is a disallowed channel. Since the EHT standard supports a wider channel width than the conventional HE or previous standards, a BSS with a wider channel width can be configured excluding the disallowed channels. For example, an EHT BSS operating channel width of 320 MHz is set. In this case, the disallowed channels are signaled, and the system operates using a maximum band of 240 MHz using 80 MHz channel 2, 80 MHz channel 3, and 80 MHz channel 4 excluding the disallowed channels. In this case, the non-EHT BSS operating channel is notified as being different from the EHT BSS operating channel. In this case, as described above, the non-EHT BSS operating channel width is notified as the widest width excluding the disallowed channels. Therefore, the non-EHT BSS operating channel width is notified as 160 MHz. In addition, the 160 MHz channel, which is a non-EHT BSS operating channel, is a channel consisting of 80 MHz channel 3 and 80 MHz channel 4. Therefore, the primary channel should be in 80 MHz channel 3 or 80 MHz channel 4. In other words, the primary channel cannot be included in 80 MHz channel 2. The primary channel means a primary 20 MHz channel. Or, the primary channel means a primary 40 MHz channel or a primary 80 MHz channel.

[0304] FIG. 30 is a diagram illustrating setting the width of a BSS operating channel according to another embodiment of the present invention.

[0305] The embodiment of Fig. 30 is an embodiment for solving the problem of limitations on the setting of the primary channel described in Fig. 29. The contents previously described are omitted.

[0306] According to one embodiment of the present invention, the non-EHT BSS operating channel width is the widest width including the primary channel, excluding the disabled channels, from the EHT operating channel width. In this case, the primary channel is a primary 20 MHz channel. In another embodiment, the primary channel is a primary 40 MHz channel or a primary 80 MHz channel. More specifically, according to one embodiment of the present invention, the BSS operating channel width included in the HE operating element is the widest width including the primary channel, excluding the disabled channels, from the EHT operating channel width. Alternatively, the BSS operating channel width included in the HE operating element is the widest width including the primary channel, excluding the disabled channels, from the channel width signaled based on the EHT operating element. In this case, more specifically, the disabled channels refer to disabled 20 MHz channels.

[0307] An embodiment of the present invention may be limited to operating in the 6 GHz band.

[0308] Also, the non-EHT BSS operating channel width is information included in the HE operation element. More specifically, the non-EHT BSS operating channel width is information included in the 6 GHz Operation Information field included in the HE operation element. More specifically, the non-EHT BSS operating channel width is channel width information included in the 6 GHz Operation Information field included in the HE operation element.

[0309] Referring to FIG. 30, there are four 80 MHz channels in succession. For example, there are 80 MHz channel 1, 80 MHz channel 2, 80 MHz channel 3, and 80 MHz channel 4. Also, 80 MHz channel 1 is a disallowed channel. Since the EHT standard supports a wider channel width than the conventional HE or previous standards, a BSS with a wider channel width can be configured excluding the disallowed channels. For example, an EHT BSS operating channel width of 320 MHz is set. In this case, the disallowed channels are signaled, and the system operates using a maximum band of 240 MHz using 80 MHz channel 2, 80 MHz channel 3, and 80 MHz channel 4 excluding the disallowed channels. In this case, the non-EHT BSS operating channel is notified differently from the EHT BSS operating channel. In this case, as described above, the non-EHT BSS operating channel width is notified as the widest width including the primary channel excluding the disallowed channels. Therefore, the non-EHT BSS operating channel width is notified as 80 MHz. In this case, the 80 MHz channel operating the non-EHT BSS is a channel consisting of 80 MHz channel 2. Also, unlike the embodiment shown in the drawing, if it is desired to set the primary channel to exist in 80 MHz channel 3 or 80 MHz channel 4, the non-EHT BSS operating channel can be set to 160 MHz. Thus, there is a degree of freedom in the selection of the primary channel.

[0310] FIG. 31 is a diagram illustrating channelization and BSS operating channel width setting according to one embodiment of the present invention.

[0311] The embodiment of Fig. 31 is an embodiment for solving the problem that the setting of the primary channel described in Fig. 29 is limited. The contents described before are omitted. Also, the embodiment of Fig. 31 is used together with the embodiment described in Fig. 30.

[0312] According to one embodiment of the present invention, channelization exists. That is, available channels (bands) are defined. FIG. 31(a) shows channelization for the 6 GHz band. For example, 80 MHz, 160 MHz, and 320 MHz channels are defined as shown in the drawing. For example, it is impossible to configure a 160 MHz channel using any two consecutive 80 MHz channels other than the 160 MHz channel defined in the channelization. Similarly, it is impossible to configure a 320 MHz channel using any four consecutive 80 MHz channels other than the 320 MHz channel defined in the channelization.

[0313] According to an embodiment of the present invention, the non-EHT BSS operating channel width is the widest width including the primary channel, excluding the disallowed channels from the EHT operating channel width. More specifically, according to an embodiment of the present invention, the non-EHT BSS operating channel width is the widest width including the primary channel, excluding the disallowed channels from the EHT operating channel width, not exceeding the channel defined by the channelization. In this case, the primary channel is a primary 20 MHz channel. In another embodiment, the primary channel is a primary 40 MHz channel or a primary 80 MHz channel. More specifically, according to an embodiment of the present invention, the BSS operating channel width included in the HE operating element is the widest width including the primary channel, excluding the disallowed channels from the EHT operating channel width, not exceeding the channel defined by the channelization. Alternatively, the BSS operating channel width included in the HE operating element is the widest width including the primary channel, excluding the disallowed channels from the channel width signaled based on the EHT operating element, not exceeding the channel defined by the channelization. In this case, more specifically, the disabled channels refer to disabled 20MHz channels.

[0314] An embodiment of the present invention may be limited to operating in the 6 GHz band.

[0315] Also, the non-EHT BSS operating channel width is information included in the HE operation element. More specifically, the non-EHT BSS operating channel width is information included in the 6 GHz Operation Information field included in the HE operation element. More specifically, the non-EHT BSS operating channel width is channel width information included in the 6 GHz Operation Information field included in the HE operation element.

[0316] Referring to FIG. 31, there are four 80 MHz channels in succession. For example, there are 80 MHz channel 1, 80 MHz channel 2, 80 MHz channel 3, and 80 MHz channel 4. Also, 80 MHz channel 1 and 80 MHz channel 4 are disallowed channels. Since the EHT standard supports a wider channel width than conventional HE or previous standards, a BSS with a wider channel width can be configured excluding the disallowed channels. For example, an EHT BSS operating channel width of 320 MHz is set. In this case, the disallowed channels are signaled and the system operates using a maximum band of 160 MHz using 80 MHz channel 2 and 80 MHz channel 3 excluding the disallowed channels. In this case, the non-EHT BSS operating channel is notified differently from the EHT BSS operating channel. In this case, as described in FIG. 30, if the non-EHT BSS operating channel width is simply notified as the widest width including the primary channel excluding the disallowed channels, the non-EHT BSS operating channel width should be notified as 160 MHz. However, a 160 MHz channel consisting of 80 MHz channel 2 and 80 MHz channel 3 may not exist based on the channelization. Therefore, such a setting of the non-EHT BSS operating channel width may be problematic, and is not possible according to the embodiment of FIG. 31. Therefore, the non-EHT BSS operating channel width is notified as the widest width among the channels defined by the channelization, including the primary channel, excluding the disallowed channels. Therefore, the non-EHT BSS operating channel width is notified as 80 MHz. In this case, the 80 MHz channel that is the non-EHT BSS operating channel is a channel consisting of 80 MHz channel 2 and 80 MHz channel 3. If the primary channel exists in 80 MHz channel 2, the 80 MHz channel that is the non-EHT BSS operating channel is 80 MHz channel 2. If the primary channel exists in 80 MHz channel 3, the 80 MHz channel that is the non-EHT BSS operating channel is 80 MHz channel 3.

[0317] Also, when the BSS operating channel width is defined as the widest width satisfying a certain condition, the 80+80MHz channel is wider than 80MHz, so the 80+80MHz channel is set as the BSS operating channel width. However, it may not be desirable to set a non-contiguous channel as the BSS operating channel. For example, it may not allow or implement a non-contiguous channel as the non-EHT BSS operating channel width. Or, according to one embodiment of the present invention, the non-EHT BSS operating channel width is not allowed as the EHT BSS operating channel width. Therefore, according to an embodiment of the present invention, the non-EHT BSS operating channel width is the widest width that excludes disallowed channels from the EHT operating channel width, includes the primary channel, does not exceed the channels defined in the channelization, and is not a non-contiguous channel. In this case, the primary channel is a primary 20MHz channel. In another embodiment, the primary channel is a primary 40MHz channel or a primary 80MHz channel. More specifically, according to one embodiment of the present invention, the BSS operating channel width included in the HE operating element is the widest width, excluding disallowed channels from the EHT operating channel width, including the primary channel, not exceeding the channels defined in the channelization, and not being a non-contiguous channel. Or, the BSS operating channel width included in the HE operating element is the widest width, excluding disallowed channels from the channel width signaled based on the EHT operating element, including the primary channel, not exceeding the channels defined in the channelization, and not being a non-contiguous channel. In this case, more specifically, the disallowed channel means a disabled 20 MHz channel.

[0318] The embodiments described in Figures 28 to 31 may be used in combination with each other. To summarize the embodiments described in Figures 28 to 31, the non-EHT BSS operating channel width is signaled to be different from the EHT operating channel width. For example, the non-EHT BSS operating channel width is signaled as the width of the widest channel in the EHT BSS operating channel that satisfies the following condition:

[0319] 1) Any channel other than Disallowed channels.

[0320] 2) Includes Primary channel.

[0321] 3) Channelization defines channels within channels.

[0322] 4) It is a contiguous channel.

[0323] According to one embodiment, all of the above conditions should be satisfied. According to another embodiment, at least one of the above conditions should be satisfied. For example, the above conditions 1), 2), and 3) should be satisfied. In addition, the widest channel among the EHT BSS operating channels that satisfies the following conditions is a channel that can be signaled based on the HE operating element, excluding the EHT operating element.

[0324] FIG. 32 is a diagram showing an EHT operation element format according to one embodiment of the present invention.

[0325] As described above, information regarding the operation of the EHT BSS is included in the EHT operating element, which is one type of the operating element described above.

[0326] In addition, the operation element is transmitted by the AP or AP MLD. The non-AP STA or non-AP MLD operates based on the operation element received from the AP or AP MLD. In addition, the AP or AP MLD operates based on the operation element it transmits.

[0327] The EHT operating element also includes information about the operating channel of the BSS. The information about the operating channel includes a channel width. The information about the operating channel also includes a CCFS (channel center frequency segment). The CCFS indicates a center frequency of a preset frequency segment. The information about the operating channel also includes a disabled channel. In this embodiment, the contents described above are omitted.

[0328] The EHT operating element indicates a disabled channel. In the present invention, the terms "disallowed", "disabled", "inactive" and "puctured" are used interchangeably. Also, the terms "channel", "subchannel" and "band" are used interchangeably. Therefore, the term "disallowed channel" used above means a disabled subchannel.

[0329] According to an embodiment of the present invention, the disabled subchannels are indicated for subchannels (bands) of a preset unit. For example, the preset unit is 20 MHz. The disabled subchannels are indicated through a bitmap. For example, each bit of the bitmap indicates whether a subchannel of the preset unit is disabled or not. Also, each bit of the bitmap corresponds to a non-overlapping subchannel. Also, the bit (bit index) of the bitmap corresponds to the subchannels of the preset unit in frequency order. For example, the bits of bit indexes B0, B1, B2, ..., B15 of the bitmap correspond to the subchannel of the preset unit with the lowest frequency, the subchannel of the preset unit with the second lowest frequency, the subchannel of the preset unit with the third lowest frequency, ..., the subchannel of the preset unit with the 16th lowest (or highest) frequency, respectively. For example, if a bit of the bitmap is set to 1, the subchannel corresponding to the bit set to 1 is disabled. Also, if a bit of the bitmap is set to 0, the subchannel corresponding to the bit set to 0 is not disabled (enabled). Alternatively, conversely, a bit value of 0 may indicate enabled and a bit value of 1 may indicate disabled, respectively.

[0330] Additionally, bits that do not correspond to the subchannels on which the BSS operates are set to a preset value, for example, 1. For example, when the BSS operates in a 160 MHz channel width, bits in the bitmap that do not correspond to the 160 MHz channel are set to a preset value. Additionally, bits that correspond to the primary 20 MHz channel are set to a preset value, for example, 0.

[0331] In addition, the STA or MLD does not transmit PPDUs, frames, or energy to disabled subchannels. The STA or MLD transmits PPDUs, frames, or energy only to subchannels that are not disabled. In addition, not transmitting to disabled subchannels is referred to as puncturing or preamble puncturing. In addition, puncturing based on disabled subchannels determined in a long term is referred to as static puncturing. For example, puncturing based on an EHT operating element that is transmitted or has been transmitted is referred to as static puncturing. In addition, puncturing in which the disabled subchannel may differ on a PPDU basis is referred to as dynamic puncturing. For example, puncturing based on a disabled subchannel included in a PPDU or frame is referred to as dynamic puncturing. In this case, the disabled subchannel included in a PPDU or frame is not disabled subchannel information included in an EHT operating element.

[0332] In addition, the STA sets the TXVECTOR parameter INACTIVE_subchannel S value based on the received or transmitted disabled subchannel information. The TXVECTOR parameter is information transmitted from the MAC layer to the PHY layer. In addition, the STA transmits a PPDU based on the TXVECTOR parameter INACTIVE_subchannel S. For example, the STA does not transmit a PPDU to a subchannel that is inactive as indicated by the TXVECTOR parameter INACTIVE_subchannel S.

[0333] Referring to FIG. 32(a), the EHT operation element includes Element ID, Length, Element ID Extension, EHT Operation Information, and Disabled Subchannel Bitmap fields. The Element ID and Element ID Extension fields serve to identify which element includes the Element ID and Element ID Extension fields. The Length field indicates the length of the element. EHT Operation Information field The Disabled Subchannel field indicates information about the operating channel of the BSS. The Disabled Subchannel Bitmap subfield is a bitmap indicating the above-mentioned disabled subchannel. There is signaling indicating whether the Disabled Subchannel Bitmap subfield exists. For example, the EHT operation element or the EHT Operation Information field includes signaling indicating whether the Disabled Subchannel Bitmap subfield exists. The signaling indicating whether the Disabled Subchannel Bitmap subfield exists is the Disabled Subchannel Bitmap Present subfield. The Disabled Subchannel Bitmap Present subfield is 1-bit. If the Disabled Subchannel Bitmap subfield exists, it is 2 octets long. Each bit in the Disabled Subchannel Bitmap subfield indicates information for a 20 MHz subchannel. The Disabled Subchannel Bitmap subfield indicates information for a total of 320 MHz.

[0334] For example, the EHT Operation Information field format is as shown in FIG. 32(b1) or FIG. 32(b2).

[0335] Referring to FIG. 32(b1), the EHT Operation Information field includes a Channel Width subfield indicating a channel width. The Channel Width subfield indicates a channel width and does not include other information. The channel width indicated by the Channel Width subfield includes 20, 40, 80, 160, and 320 MHz. The values ​​of bits B2, B1, and B0 of the Channel Width subfield being 000, 001, 010, 011, and 100 indicate 20, 40, 80, 160, and 320 MHz, respectively. The Channel Width subfield is 3-bit in one embodiment. In another embodiment, the Channel Width subfield may be 1-octet. The EHT Operation Information field also includes the Disabled Subchannel Bitmap subfield described above. Based on the value of the Disabled Subchannel Bitmap Present subfield, the EHT operation element determines whether to include the Disabled Subchannel Bitmap subfield. For example, if the Disabled Subchannel Bitmap Present subfield is set to 1, then the EHT operating element includes the Disabled Subchannel Bitmap subfield. If the Disabled Subchannel Bitmap Present subfield is set to 0, then the EHT operating element does not include the Disabled Subchannel Bitmap subfield.

[0336] Referring to FIG. 32(b2), the EHT Operation Information field indicates, in one subfield, 1) channel width, and 2) whether the EHT operation element includes the Disabled Subchannel Bitmap subfield. That is, one subfield can include the functions of the Channel Width subfield and the Disabled Subchannel Bitmap Present subfield described in FIG. 32(b1). For example, the one subfield is the Channel Width (Disabled Subchannel Bitmap Present) subfield shown in FIG. 32(b2). For example, one value indicated by the Channel Width (Disabled Subchannel Bitmap Present) subfield indicates what the channel width is and whether the Disabled Subchannel Bitmap subfield is included. For example, each value of the Channel Width (Disabled Subchannel Bitmap Present) subfield indicates one of the pieces of information listed in the following (1) to (10).

[0337] (1) The channel width is 20 MHz and does not include the Disabled Subchannel Bitmap subfield.

[0338] (2) The channel width is 20 MHz and includes a Disabled Subchannel Bitmap subfield.

[0339] (3) The channel width is 40 MHz and does not include the Disabled Subchannel Bitmap subfield.

[0340] (4) The channel width is 40 MHz and includes a Disabled Subchannel Bitmap subfield.

[0341] (5) The channel width is 80 MHz and does not include the Disabled Subchannel Bitmap subfield.

[0342] (6) The channel width is 80 MHz and includes a Disabled Subchannel Bitmap subfield.

[0343] (7) The channel width is 160 MHz and does not include the Disabled Subchannel Bitmap subfield.

[0344] (8) Channel width is 160 MHz and includes a Disabled Subchannel Bitmap subfield.

[0345] (9) The channel width is 320 MHz and does not include the Disabled Subchannel Bitmap subfield.

[0346] (10) Channel width is 320 MHz and includes a Disabled Subchannel Bitmap subfield.

[0347] However, the BSS operating channel may be 20 MHz wide, and the unit for setting the disabled subchannel may be 20 MHz. In this case, if the BSS operating channel is 20 MHz wide, the disabled subchannel is not set. Or, the primary 20 MHz channel is not disabled. Therefore, in this case, it is meaningless to include the Disabled Subchannel Bitmap subfield. Also, if the BSS operating channel is 40 MHz wide, and the unit for setting the disabled subchannel is 20 MHz, the primary 20 MHz channel is a secondary 20 MHz channel that can be disabled if it is 40 MHz channel width if it is not disabled. However, in this case, since the only enabled subchannel is the primary 20 MHz channel, it operates the same as if the BSS operating channel width is 20 MHz. Therefore, the disabled subchannel is not set when the channel width is 40 MHz. Also, in this case, it is meaningless to include the Disabled Subchannel Bitmap subfield.

[0348] Therefore, each value of the Channel Width (Disabled Subchannel Bitmap Present) subfield indicates one of the pieces of information listed in (1) to (8) below.

[0349] (1) The channel width is 20 MHz and does not include the Disabled Subchannel Bitmap subfield.

[0350] (2) The channel width is 40 MHz and does not include the Disabled Subchannel Bitmap subfield.

[0351] (3) The channel width is 80 MHz and does not include the Disabled Subchannel Bitmap subfield.

[0352] (4) The channel width is 80 MHz and includes a Disabled Subchannel Bitmap subfield.

[0353] (5) The channel width is 160 MHz and does not include the Disabled Subchannel Bitmap subfield.

[0354] (6) The channel width is 160 MHz and includes a Disabled Subchannel Bitmap subfield.

[0355] (7) The channel width is 320 MHz and does not include the Disabled Subchannel Bitmap subfield.

[0356] (8) Channel width is 320 MHz and includes a Disabled Subchannel Bitmap subfield.

[0357] Alternatively, in the above (1) and (2), this has the same meaning as including only channel width information, without including information that does not include the Disabled Subchannel Bitmap subfield.

[0358] In Fig. 32(b2), the Channel Width (Disabled Subchannel Bitmap Present) subfield is 3 bits, or in Fig. 32(b2), the Channel Width (Disabled Subchannel Bitmap Present) subfield is 1 octet.

[0359] 32(b1) or 32(b2), the EHT Operation Information field includes CCFS information. For example, the Channel Center Frequency Segment 0 subfield and the Channel Center Frequency Segment 1 subfield include CCFS information.

[0360] FIG. 33 is a diagram illustrating an example of transmission taking into account deactivated subchannels according to an embodiment of the present invention.

[0361] According to an embodiment of the present invention, a disabled subchannel is indicated as described in FIG. 32. Referring to FIG. 33, a PPDU or frame is transmitted based on the indicated or indicated disabled subchannel. For example, a PPDU or frame is transmitted based on the most recently indicated or indicated disabled subchannel. For example, a PPDU or frame is not transmitted to the most recently indicated or indicated disabled subchannel. For example, when transmitting a non-HT (duplicate) PPDU, a PPDU is transmitted based on the indicated or indicated disabled subchannel. Or, when transmitting a non-HT (duplicate) PPDU, a PPDU is transmitted based on the above-mentioned TXVECTOR parameter INACTIVE_subchannel S.

[0362] Referring to FIG. 33, the AP transmits a PPDU including an MU-RTS frame. At this time, the PPDU is transmitted on a subchannel other than the disabled subchannel. Also, the STA that receives the MU-RTS frame responds by transmitting a PPDU including a CTS frame. At this time, the STA transmitting the CTS frame transmits the PPDU on a subchannel other than the disabled subchannel. For example, if the channel or RU indicated by the MU-RTS frame includes a disabled subchannel or is indicated regardless of the disabled subchannel, the STA transmits the PPDU on a subchannel other than the known disabled subchannel. Also, if the MU-RTS frame indicates an additional disabled subchannel other than the known disabled subchannel, the STA responds on a subchannel other than the known disabled subchannel and the additional disabled subchannel. A preamble is not transmitted on the disabled subchannel. Also, the STA that receives the CTS frame transmits a subsequent frame, for example, a Data frame. In this case, the PPDU is transmitted only on subchannels other than the disabled subchannel. If the CTS frame indicates additional disabled subchannels, the PPDU is transmitted on subchannels other than the additional disabled subchannels.

[0363] FIG. 34 illustrates an example of signaling of a deactivated subchannel according to one embodiment of the present invention.

[0364] In the embodiment of FIG. 34, a more specific method of indicating a disabled subchannel will be described. The contents described above are omitted. In the embodiment of the present invention, the description that the EHT operating element includes a disabled subchannel bitmap subfield has the same meaning as the case where the Disabled subchannel bitmap Present subfield or the signaling indicating whether the Disabled subchannel bitmap subfield is included is indicated to include the Disabled subchannel bitmap subfield. Also, the description that the EHT operating element does not include a disabled subchannel bitmap subfield has the same meaning as the case where the Disabled subchannel bitmap Present subfield or the signaling indicating whether the Disabled subchannel bitmap subfield is included is indicated to not include the Disabled subchannel bitmap subfield.

[0365] According to an embodiment of the present invention, even if a disabled subchannel exists in a BSS, the Disabled Subchannel Bitmap subfield may not always be included in the EHT operation element. Thus, a STA receiving an EHT operation element does not recognize that there is no disabled subchannel even if the EHT operation element does not include the Disabled Subchannel Bitmap subfield. According to an embodiment, this is limited to the case where the EHT operation element is included in a Beacon frame. Alternatively, this is limited to the case where the EHT operation element is included in a Beacon frame or a Probe Response frame. This can reduce the problem of management frames such as Beacon frames and Probe Response frames occupying a large amount of resources.

[0366] However, if disabled subchannels exist, STAs must be made aware of them explicitly before operating.

[0367] Therefore, according to one embodiment of the present invention, the EHT operation element included in the preset frame always includes a Disabled Subchannel Bitmap subfield. The preset frame is an Association Response frame or a Reassociation Response frame. Also, the preset frame is an Association Response frame, a Reassociation Response frame, or a Probe Response frame. Also, in the present invention, when an STA operates based on a received preset frame, it means the most recently received preset frame.

[0368] According to a more specific embodiment, if a disabled subchannel exists, the EHT operation element included in the pre-configured frame always includes the Disabled Subchannel Bitmap subfield. In this case, if a disabled subchannel does not exist, even the EHT operation element included in the pre-configured frame does not include the Disabled Subchannel Bitmap subfield. Also, if the pre-configured frame received by the STA does not include the Disabled Subchannel Bitmap subfield, the STA recognizes that a disabled subchannel does not exist and operates. If the pre-configured frame received by the STA includes the Disabled Subchannel Bitmap subfield, the STA recognizes that a disabled subchannel does not exist based on the received Disabled Subchannel Bitmap subfield and operates. For example, a STA that does not receive the Disabled Subchannel Bitmap subfield at all determines that a disabled subchannel does not exist. The reason that the Disabled Subchannel Bitmap subfield cannot be received at all is because the Association Response frame does not include the Disabled Subchannel Bitmap subfield.

[0369] According to another specific embodiment, the EHT operating element included in the preset frame always includes the Disabled Subchannel Bitmap subfield regardless of whether a disabled subchannel exists. In this case, if there is no disabled subchannel, the EHT operating element included in the preset frame indicates that there is no disabled subchannel in the Disabled Subchannel Bitmap subfield (e.g., all bits corresponding to the operating channel are set to 0). The STA recognizes whether there is a disabled subchannel or which subchannel is a disabled subchannel based on the Disabled Subchannel Bitmap subfield included in the received preset frame, and operates accordingly.

[0370] Referring to FIG. 34, an AP transmits a Beacon frame, an Association Response frame, and a Reassociation Response frame. A management frame transmitted by the AP, for example, a Beacon frame, an Association Response frame, a Reassociation Response frame, and a Probe Response frame, includes an EHT operation element. In addition, a disabled subchannel exists in the BSS operated by the AP. Although a disabled subchannel exists, the AP sets the Disabled subchannel bitmap Present subfield to 0 (does not include a bitmap) when transmitting a Beacon frame. This is to reduce the size of the Beacon frame. Even if a STA receives an EHT operation element in which the Disabled subchannel bitmap Present subfield is set to 0, the STA does not recognize whether a disabled subchannel exists based on the EHT operation element. The STA recognizes whether a disabled subchannel exists and which subchannel is disabled based on the EHT operation element included in the most recently received Association Response frame or Reassociation Response frame.

[0371] Also, when the AP transmits an Association Response frame or a Reassociation Response frame, it always sets the Disabled subchannel bitmap Present subfield to 1 (if the bitmap is included). When the STA transmits a PPDU, it transmits based on the EHT operation element and the Disabled subchannel bitmap subfield included in the most recently received Association Response frame or Reassociation Response frame. At this time, the STA performs acquiring for the subchannel indicated by the disabled subchannel and performs acquired transmission. At this time, even if the most recently received EHT operation element does not include the Disabled subchannel bitmap subfield as shown in FIG. 34, the STA does not recognize that there is no disabled subchannel because the most recently received EHT operation element is included in the Beacon frame.

[0372] FIG. 35 illustrates signaling of deactivated subchannels and critical updates according to one embodiment of the present invention.

[0373] According to one embodiment of the present invention, the following events are classified as critical updates:

[0374] (a)Inclusion of a Channel Switch Announcement element

[0375] (b)Inclusion of an Extended Channel Switch Announcement element

[0376] (c)Modification of the EDCA parameters element

[0377] (d)Inclusion of a quiet element

[0378] (e) Modification of the DSSS Parameter Set

[0379] (f) Modification of the CF Parameter Set element

[0380] (g) Modification of the HT operation element

[0381] (h) Inclusion of a Wide Bandwidth Channel Switch element

[0382] (i) Inclusion of a Channel Switch Wrapper element

[0383] (j) Inclusion of an Operating Mode Notification element

[0384] (k) Inclusion of a Quiet Channel element

[0385] (l) Modification of the VHT operation element

[0386] (m) Modification of the HE operation element

[0387] (n) Insertion of a Broadcast TWT element

[0388] (o) Inclusion of the BSS Color Change Announcement element

[0389] (p) Modification of the MU EDCA Parameter Set element

[0390] (q)Modification of the Spatial Reuse Parameter Set element

[0391] (r)Modification of the UORA Parameter Set element

[0392] (s)Modification of the EHT Operational Elements

[0393] Modification of an element means that there is a change in at least one field value of the element. Inclusion of an element means that the element is included in a beacon frame. Insertion of an element means that the element was not included in the previous beacon frame but is included in the current beacon frame. Or, insertion of an element means that the element was not included in the previous beacon frame but is included in the next beacon frame.

[0394] Also, when a critical update occurs, the AP changes a preset field (or subfield) value. According to an embodiment, the AP changes the preset field value when a critical update occurs not only for the BSS operated by the AP but also for a BSS operated by another AP in the MLD to which the AP belongs. That is, the preset field value is changed when an element corresponding to a critical update included in a multi-link element is changed. Alternatively, the AP changes the preset frame value not only for the BSS operated by the AP but also for a BSS operated by another AP in the multiple BSSID set to which the AP belongs. That is, the preset field value is changed when an element corresponding to a critical update included in a multiple BSSID element is changed. When the STA confirms that the preset field has changed, it checks which critical update has occurred or which element has changed, and changes the corresponding parameter to operate.

[0395] For example, the preset field is a flag indicating whether a critical update has occurred. For example, the preset field is a Check Beacon Flag subfield or a critical update Flag subfield. The flag indicating whether a critical update has occurred is 1-bit. If the flag indicating whether a critical update has occurred is set to 1, a critical update has occurred.

[0396] Alternatively, the preset field is a field indicating a sequence. For example, the preset field is a field whose value increases when a critical update occurs. For example, the preset field is a field whose value increases by 1 when a critical update occurs. In this case, the sequence value is a value obtained by modulo calculation with a maximum value. For example, the preset field is a Check Beacon field or a Change Sequence field.

[0397] As described in FIG. 34, even if a disabled subchannel exists, the EHT operation element may not include the Disabled Subchannel Bitmap subfield. Also, when a disabled subchannel exists, the EHT operation element may include the Disabled Subchannel Bitmap subfield. Also, as described in FIG. 32, when the EHT operation element changes whether or not it includes the Disabled Subchannel Bitmap subfield, the Disabled Subchannel Bitmap Present subfield value included in the EHT operation element is changed. Therefore, if a change in at least one value included in the EHT operation element is defined as a critical update, it is also classified as a critical update when the Disabled Subchannel Bitmap subfield is included and then not included simply to reduce the size of the management frame, or when there is no change in the actual disabled subchannel but the inclusion or non-inclusion of the Disabled Subchannel Bitmap subfield is changed. Therefore, the STA unnecessarily checks the change in the parameter.

[0398] Therefore, according to one embodiment of the present invention, whether the EHT operating element includes the Disabled Subchannel Bitmap subfield is not classified as a critical update, or a change in the Disabled Subchannel Bitmap Present subfield included in the EHT operating element is not classified as a critical update. This is limited to the case where the EHT operating element is included in the beacon frame.

[0399] Alternatively, a change in at least one value of a field other than the Disabled Subchannel Bitmap Present subfield of an EHT operation element is classified as a critical update, or a change in a Disabled Subchannel Bitmap subfield included in an EHT operation element is classified as a critical update.

[0400] Alternatively, the EHT operation elements included in the Association Response frame or Reassociation Response frame (or Probe Response frame) are classified as a critical update when their values ​​change compared to the EHT operation elements included in the previous Association Response frame or Reassociation Response frame (or Probe Response frame). In this case, a change in the value of the Disabled Subchannel Bitmap Present subfield is also classified as a critical update.

[0401] Referring to FIG. 35, when the AP transmits Beacon frame1, it sets the Disabled subchannel bitmap Present subfield to 1. Also, when the AP transmits Beacon frame2, it sets the Disabled subchannel bitmap Present subfield to 0. This is to reduce the size of Beacon frame2. Also, at this time, the value of the Disabled subchannel bitmap Present subfield included in the EHT operation element has changed from the previous one, but it does not need to be classified as a critical update. Therefore, the AP does not change the value of the preset field to be changed when a critical update included in Beacon frame2 occurs. Also, Beacon frame3 sets the Disabled subchannel bitmap Present subfield to 1, and the value of the Disabled subchannel bitmap subfield is different from the Disabled subchannel bitmap subfield included in Beacon frame1. In this case, it is classified as a critical update. Also, the AP changes the value of the preset field to be changed when a critical update included in Beacon frame3 occurs.

[0402] FIG. 36 illustrates signaling and critical updates for deactivated subchannels according to another embodiment of the present invention.

[0403] If the embodiment described in FIG. 34 or FIG. 35 is used, the STA must additionally check the type of frame to determine whether a disabled subchannel exists, which places a burden on the implementation. Therefore, FIG. 36 describes an embodiment for solving this problem. In this embodiment, the contents described above are omitted.

[0404] According to an embodiment of the present invention, if there is a disabled subchannel, the EHT operation element always includes the Disabled Subchannel Bitmap subfield. Therefore, the STA determines the disabled subchannel based on the most recently received EHT operation element. This includes the case where the EHT operation element is included not only in the Association Response frame or Reassociation Response frame but also in the Beacon frame.

[0405] In addition, in this embodiment, if there is no disabled subchannel, the AP does not need to include the Disabled Subchannel Bitmap subfield in the EHT operation element to be transmitted. Also, if the EHT operation element received by the STA does not include the Disabled Subchannel Bitmap subfield, it is determined that there is no disabled subchannel.

[0406] That is, the operating element includes a Disabled Subchannel Bitmap Present subfield indicating whether a Disabled Subchannel Bitmap subfield indicating the at least one unavailable channel (or disabled subchannel, or punctured subchannel, etc.) of the BSS operating channel is included. In this case, each bit of the Disabled Subchannel Bitmap subfield indicates whether a corresponding subchannel is unavailable. For example, a bit value of '0' indicates that the corresponding channel is available (e.g., not punctured), and a bit value of '1' indicates that the corresponding channel is available (e.g., punctured).

[0407] Also, the bit value of the deactivated subchannel bitmap present subfield indicates whether the deactivated subchannel bitmap subfield is present or not. For example, if the bit value of the deactivated subchannel bitmap present subfield is set to '1', the deactivated subchannel bitmap subfield is included in the operation element, and if the bit value of the deactivated subchannel bitmap present subfield is set to '0', the deactivated subchannel bitmap subfield is not included in the operation element.

[0408] Or, if there is no disabled subchannel, the AP includes a Disabled Subchannel Bitmap subfield in the EHT operation element to be transmitted, but sets all bits corresponding to the operating subchannels to 0 (enabled). Even if the received EHT operation element includes a Disabled Subchannel Bitmap subfield, if all bits corresponding to the operating channels are set to enabled, the STA that receives the EHT operation element determines that there is no disabled subchannel and operates accordingly.

[0409] Thus, according to the embodiment described above, there are two ways for the EHT operator to indicate that there are no deactivated subchannels. One of the two ways is to not include the deactivated subchannel bitmap subfield in the EHT operator, and the other is to set all values ​​of the bits of the deactivated subchannel bitmap subfield included in the EHT operator to enabled, which correspond to the operating channels. In addition, either of the two ways may be used depending on the AP's selection. When the configuration of the EHT operator is switched between the two methods, the value of the field included in the EHT operator is changed. For example, the value of the deactivated subchannel bitmap present subfield is changed. According to the embodiment of the present invention, the switch between these two methods is not classified as a critical update. That is, even if the value of the deactivated subchannel bitmap present subfield is changed, it is not classified as a critical update unless the deactivated subchannel bitmap subfield indicates at least one disabled subchannel.

[0410] When the deactivated subchannel bitmap presence subfield is changed, the case where the deactivated subchannel bitmap subfield indicates at least one deactivated subchannel is classified as a critical update. For example, after the deactivated subchannel bitmap subfield transmits an EHT operation element indicating at least one disabled subchannel, the case where the deactivated subchannel bitmap subfield transmits an EHT operation element not including the deactivated subchannel bitmap subfield is classified as a critical update. Or, after the EHT operation element not including the deactivated subchannel bitmap subfield is transmitted, the case where the deactivated subchannel bitmap subfield transmits an EHT operation element indicating at least one disabled subchannel is classified as a critical update.

[0411] In addition, any change in any field of an EHT operation element other than those mentioned above is also classified as a critical update.

[0412] Therefore, if the value of the field indicating the presence or absence of the deactivated subchannel bitmap subfield indicating the unavailable subchannel is changed, it is classified as a critical update and the value of the field indicating the critical update is increased. In this case, the AP transmits a frame (e.g., a TIM frame) including a field indicating a critical update to the STA, and the STA recognizes whether the operational parameters have changed based on the frame. In other words, if the bit value of the subchannel bitmap presence subfield, which is a field indicating the presence or absence of the deactivated subchannel bitmap subfield, is changed from '0' to '1' (or from '1' to '0'), this is classified as a critical update. Therefore, the AP increases the value of the field indicating the critical update and transmits it to the STA. In this case, the STA recognizes that the operational parameters have changed, and recognizes the updated operational parameters by receiving a management frame.

[0413] According to another embodiment, the above-mentioned EHT operating element does not allow one of two ways to indicate that there is no deactivated subchannel. For example, in order for the EHT operating element to indicate that there is no deactivated subchannel, it is not necessary to always include the deactivated subchannel bitmap subfield. That is, the deactivated subchannel bitmap presence subfield is always set to 0. Also, the EHT operating element does not allow a setting that includes the deactivated subchannel bitmap subfield but does not indicate any deactivated subchannel. For example, the EHT operating element does not allow all bits of the deactivated subchannel bitmap subfield that correspond to the operating channel to be set to enabled while including the deactivated subchannel bitmap subfield. This is because such a setting can be redundant. According to an embodiment of the present invention, if the EHT operating element includes the deactivated subchannel bitmap subfield, it can indicate at least one deactivated subchannel. That is, if the EHT operating element includes the deactivated subchannel bitmap subfield, at least one bit of the bits of the deactivated subchannel bitmap subfield that correspond to the operating channel is set to 1. In this case, if at least one of the values ​​of the fields included in the EHT operation element is changed, it is classified as a critical update. If the value of the inactivated subchannel bitmap presence subfield included in the EHT operation element is changed, it may be classified as a critical update.

[0414] In the embodiment of the present invention, the description limited to the value corresponding to the operating channel among the deactivated subchannel bitmap subfields may be extended to the bit of the deactivated subchannel bitmap subfields. For example, the embodiment in which the value corresponding to the operating channel among the deactivated subchannel bitmap subfields is set to the same value may be extended to the embodiment in which all bits of the deactivated subchannel bitmap subfields are set to the same value.

[0415] Referring to FIG. 36, the AP transmits Beacon frame1, Beacon frame2, and Beacon frame3, each of which includes an EHT operation element. Beacon frame1 sets the deactivated subchannel bitmap presence subfield to 1. Also, the deactivated subchannel bitmap subfield included in Beacon frame1 indicates at least one deactivated subchannel (puctured subchannel). The STA receiving Beacon frame1 determines whether a deactivated subchannel exists and which subchannel is disabled based on the deactivated subchannel bitmap subfield. Also, the channel status is changed and the AP uses all subchannels. The deactivated subchannel bitmap presence subfield included in the EHT operation element included in Beacon frame2 is set to 0. Therefore, the deactivated subchannel bitmap subfield does not exist in the EHT operation element included in Beacon frame2. The STA receiving the EHT operation element determines that there is no deactivated subchannel by confirming that the deactivated subchannel bitmap subfield does not exist. At this time, the AP includes a deactivated subchannel bitmap subfield indicating deactivated subchannels in Beacon frame 1, but does not include a deactivated subchannel bitmap subfield in Beacon frame 2, which is classified as a critical update. The EHT operating element included in Beacon frame 3 sets the deactivated subchannel bitmap presence subfield to 1, and the deactivated subchannel bitmap subfield included in the EHT operating element included in Beacon frame 3 indicates that there are no deactivated subchannels. That is, all bits corresponding to the operating channels in the deactivated subchannel bitmap subfield are set to 0.In this case, since Beacon frame 2 indicates that there are no deactivated channels by not including the deactivated subchannel bitmap subfield, and Beacon frame 3 similarly indicates that there are no deactivated channels, this case is not classified as a critical update.

[0416] FIG. 37 is a diagram showing an EHT operating element format according to one embodiment of the present invention.

[0417] The length of the deactivated subchannel bitmap subfield described in FIG. 32 is fixed if it exists. However, the channel width in which the BSS operates may not be the maximum channel width that the element supports signaling, and in such a case, the deactivated subchannel bitmap subfield should contain a redundant value. Therefore, in the present invention, a method for reducing the length of the deactivated subchannel bitmap subfield is described.

[0418] According to an embodiment of the present invention, the length of the deactivated subchannel bitmap subfield included in the EHT operating element varies depending on the channel width indicated by the EHT operating element. For example, if the channel width indicated by the EHT operating element is 320 MHz, the deactivated subchannel bitmap subfield included in the EHT operating element is 2-octet. Also, if the channel width indicated by the EHT operating element is less than 320 MHz, that is, 160 MHz or less, the deactivated subchannel bitmap subfield included in the EHT operating element is 1-octet. If the channel width subfield included in the EHT operating element is 0, 1, 2, 3, or 4, it indicates that the channel width is 20, 40, 80, 160, or 320 MHz, respectively.

[0419] Referring to FIG. 37, the EHT operation element includes an EHT Operation Information field and a deactivated subchannel bitmap subfield. The EHT Operation Information field includes a channel width subfield and a deactivated subchannel bitmap presence subfield. If the deactivated subchannel bitmap presence subfield is set to 0, the deactivated subchannel bitmap subfield is 0-octet, i.e., not present. If the deactivated subchannel bitmap presence subfield is set to 1 and the channel width subfield indicates a channel width of 320 MHz, the length of the deactivated subchannel bitmap subfield is 2-octets. If the deactivated subchannel bitmap presence subfield is set to 1 and the channel width subfield indicates a channel width of 160 MHz or less, the length of the deactivated subchannel bitmap subfield is 1-octet.

[0420] According to an embodiment of the present invention, the length of the deactivated subchannel bitmap subfield varies depending on the band corresponding to the EHT operation element. For example, if the band corresponding to the EHT operation element is the 2.4 GHz band, the length of the deactivated subchannel bitmap subfield is 1-octet. This is because 320 MHz channelization is not defined in the 2.4 GHz band. Also, if the band corresponding to the EHT operation element is the 5 or 6 GHz band, the length of the deactivated subchannel bitmap subfield is 2-octet. The band corresponding to the EHT operation element is indicated by the HT operation element, VHT operation element, or HE operation element corresponding to the EHT operation element. For example, the channel number indicates the corresponding band.

[0421] FIG. 38 is a diagram showing an EHT operating element format according to another embodiment of the present invention.

[0422] The EHT operation element described in Figure 32 or Figure 37 includes a reserved field for byte alignment. Therefore, Figure 38 describes an embodiment in which the reserved field is reduced and a deactivated subchannel is signaled.

[0423] According to one embodiment of the present invention, the EHT operation element always includes a deactivated subchannel bitmap subfield for the pre-configured subchannel 1. Referring to FIG. 38, the deactivated subchannel bitmap subfield for the pre-configured subchannel 1 is the deactivated subchannel bitmap 1 subfield. The deactivated subchannel bitmap 1 subfield is included in the EHT Operation Information field. For example, the deactivated subchannel bitmap 1 subfield has a length of 1-octet. The deactivated subchannel bitmap 1 subfield includes a bit corresponding to each 20 MHz subchannel of the pre-configured subchannel 1.

[0424] According to one embodiment of the present invention, the EHT operation element selectively includes a deactivated subchannel bitmap subfield for the pre-configured subchannel 2. Referring to FIG. 38, the deactivated subchannel bitmap subfield for the pre-configured subchannel 2 is the deactivated subchannel bitmap 2 subfield. The deactivated subchannel bitmap 2 subfield is included in a position other than the EHT Operation Information field. For example, if the deactivated subchannel bitmap 2 subfield exists, it has a length of 1-octet. The deactivated subchannel bitmap 2 subfield includes a bit corresponding to each 20 MHz subchannel of the pre-configured subchannel 2.

[0425] According to one embodiment, the pre-defined sub-channel 1 is a primary 160 MHz channel, or the pre-defined sub-channel 1 is a 160 MHz channel including a primary 20 MHz channel, and the pre-defined sub-channel 2 is a secondary 160 MHz channel.

[0426] According to another embodiment, the preset sub-channel 1 is a 160 MHz channel having a lower frequency among the 320 MHz channels in operation, and the preset sub-channel 2 is a 160 MHz channel having a higher frequency among the 320 MHz channels in operation.

[0427] Also, there is signaling that indicates whether the EHT operation element includes the deactivated subchannel bitmap 2 subfield. For example, the signaling that indicates whether the EHT operation element includes the deactivated subchannel bitmap 2 subfield is included in the EHT Operation Information field.

[0428] According to one embodiment, the EHT Operation Information field includes signaling indicating whether the EHT operation element includes a deactivated subchannel bitmap 2 subfield as one subfield. For example, there is a 1-bit signaling indicating whether the EHT operation element includes a deactivated subchannel bitmap 2 subfield. According to another embodiment, as described in FIG. 32, one subfield included in the EHT Operation Information field indicates the channel width and indicates whether the deactivated subchannel bitmap 2 subfield is included. For example, if the channel width is 320 MHz, the deactivated subchannel bitmap 2 subfield is included. In this case, whether the deactivated subchannel bitmap 2 subfield is included is indicated based on the bit of the bit index B2 of the channel width subfield. For example, a preset bit of the channel width subfield indicates whether the deactivated subchannel bitmap 2 subfield is included. Alternatively, there is a value indicating that the channel width is 320 MHz and includes a deactivated subchannel bitmap 2 subfield, and there is a value indicating that the channel width is 320 MHz and does not include a deactivated subchannel bitmap 2 subfield.

[0429] Also, if the channel width is 160 MHz or less, the EHT operating element is set not to include the Deactivated Subchannel Bitmap 2 subfield.

[0430] A STA receiving an EHT operating element that does not include the Deactivated Subchannel Bitmap 2 subfield determines that pre-configured sub-channel 2 is not used in the BSS or that there is no deactivated sub-channel in pre-configured sub-channel 2.

[0431] FIG. 39 is a flow chart showing an example of the operation of a terminal according to one embodiment of the present invention.

[0432] Referring to FIG. 39, the STA receives an operating element including information about an operating channel from the AP and transmits a PPDU.

[0433] In detail, the STA receives a management frame including a first operating element and a second operating element from the AP (S39010).

[0434] The first operating element indicates a BSS operating channel for a legacy STA, and the second operating element indicates a BSS operating channel for the STA that is not the legacy STA.

[0435] Next, the STA transmits a PPDU to the AP based on the first operating element or the second operating element S39020.

[0436] In this case, if the BSS operating channel for a STA includes at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is different from the BSS operating channel for the STA indicated by the second operating element.

[0437] If the BSS operating channel for the STA includes at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is a contiguous channel including a primary channel within the BSS operating channel for the STA indicated by the second operating element.

[0438] If the BSS operating channel for the STA includes at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is set within the maximum bandwidth with the at least one unavailable channel excluded within the BSS operating channel for the STA indicated by the second operating element.

[0439] The first operating entity is an operating entity for HE STAs, and the second operating entity is an operating entity for EHT STAs.

[0440] The second operating element includes a deactivated subchannel bitmap present subfield indicating whether or not to include a deactivated subchannel bitmap subfield indicating the at least one unavailable channel of the BSS operating channel for the STA.

[0441] Each bit of the Deactivated Subchannel Bitmap subfield indicates whether a corresponding unavailable channel is included in the BSS serving channels for that STA.

[0442] If the BSS operating channel for the STA does not include the at least one unavailable channel, the value of the Deactivated Subchannel Bitmap Present subfield is set to '0', which is a value indicating that the Deactivated Subchannel Bitmap subfield is not included.

[0443] The STA receives a frame including a specific field indicating whether or not an operational parameter is changed from the AP, and the value of the specific field is increased if the operational parameter is changed.

[0444] The value of the particular field is increased if the inclusion or exclusion of the deactivated subchannel bitmap subfield is changed or if the inclusion or exclusion of the at least one unavailable channel is changed.

[0445] A STA receives a trigger frame instructing one or more STAs to transmit a PPDU, and receives a multi-STA Block ACK frame in response to the PPDU.

[0446] In this case, if at least one of the one or more STAs transmitting the PPDU in response to the trigger frame includes the legacy STA, the size of the Ack information for each of the at least one STA included in the multi-STA Block ACK frame is limited to a specific size or less.

[0447] However, if at least one of the one or more STAs transmitting the PPDU in response to the trigger frame includes the legacy STA, and the multi-STA Block ACK frame includes only Ack information regarding the PPDU of the STA, the size of the Ack information is not limited to or less than the specific size.

[0448] The above description of the present invention is for illustrative purposes only, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. Therefore, it should be understood that the above-described embodiments are illustrative in all respects and are not limiting. For example, each component described as a single component may be implemented in a distributed form, and each component described as a distributed form may be implemented in a combined form.

[0449] The scope of the present invention is indicated by the claims set forth below rather than by the above detailed description, and all modifications and variations derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0450] 110 Processor 120 Communications Department 140 User Interface Section 150 display units 160 Memory 210 Processor 220 Communications Department 260 Memory

Claims

1. In a station (STA) of a wireless communication system, A transmitter / receiver unit; a processor for controlling the transceiver; The processor, A management frame including a first operation element and a second operation element is received from an AP (Access Point), The first operating element indicates a BSS (Basic Service Set) operating channel for a legacy STA; The second operating element indicates a BSS operating channel for the STA that is not the legacy STA; transmit a PPDU to the AP based on the first operating element or the second operating element; If the BSS operating channel for the STA includes at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is different from the BSS operating channel for the STA indicated by the second operating element.

2. 2. The STA of claim 1, wherein when the BSS operating channel for the STA includes the at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is a contiguous channel including a primary channel within the BSS operating channel for the STA indicated by the second operating element.

3. STA according to claim 2, wherein, when the BSS operating channel for the STA includes the at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is set within the maximum bandwidth with the at least one unavailable channel excluded within the BSS operating channel for the STA indicated by the second operating element.

4. The first operating element is an operating element for a High Efficiency (HE) STA, The STA of claim 1 , wherein the second operating element is an operating element for an Extremely High Throughput (EHT) STA.

5. The STA of claim 1, wherein the second operating element includes a Disabled Subchannel Bitmap Present subfield indicating whether or not the BSS includes a Disabled Subchannel Bitmap subfield indicating the at least one unavailable channel of the BSS operating channel for the STA.

6. The STA of claim 5 , wherein each bit of the Deactivated Subchannel Bitmap subfield indicates whether a corresponding unavailable channel is included in the BSS serving channels for the STA.

7. 6. The STA of claim 5, wherein if the BSS operating channel for the STA does not include the at least one unavailable channel, the value of the Deactivated Subchannel Bitmap Present subfield is set to '0', a value indicating that the Deactivated Subchannel Bitmap subfield is not included.

8. The processor, A frame including a specific field indicating whether or not an operational parameter is to be changed is received from the AP. The STA of claim 5, wherein the value of the specific field is increased when the operation parameter is changed.

9. The STA of claim 8, wherein the value of the particular field is increased when the inclusion / non-inclusion of the deactivated subchannel bitmap subfield is changed or when the inclusion / non-inclusion of the at least one unavailable channel is changed.

10. The processor, receiving a trigger frame instructing one or more STAs to transmit a PPDU; In response to the PPDU, a multi-STA Block ACK frame is received.

2. The STA of claim 1, wherein, when at least one of the one or more STAs transmitting the PPDU in response to the trigger frame includes the legacy STA, the size of the Ack information for each of the at least one STA included in the multi-STA Block ACK frame is limited to a specific size or less.

11. 11. The STA of claim 10, wherein the at least one STA that transmits the PPDU in response to the trigger frame among the one or more STAs includes the legacy STA, and the multi-STA Block ACK frame is transmitted via a resource unit (RU) individually allocated to the STA by the AP, the size of the Ack information is not limited to the specific size or less.

12. A method for a station (STA) in a wireless communication system to transmit a frame, comprising: receiving a management frame including a first operating element and a second operating element from an AP; The first operating element indicates a BSS operating channel for a legacy STA; The second operating element indicates a BSS operating channel for the STA that is not the legacy STA; and transmitting a PPDU to the AP based on the first operating element or the second operating element, A method in which, when the BSS operating channel for the STA includes at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is different from the BSS operating channel for the STA indicated by the second operating element.

13. The method of claim 12, wherein if the BSS operating channel for the STA includes at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is a contiguous channel including a main channel within the BSS operating channel for the STA indicated by the second operating element.

14. The method of claim 13, wherein, if the BSS operating channel for the STA includes the at least one unavailable channel and / or exceeds the maximum bandwidth supported by the legacy STA, the BSS operating channel for the legacy STA indicated by the first operating element is set within the maximum bandwidth with the at least one unavailable channel excluded within the BSS operating channel for the STA indicated by the second operating element.

15. the first operating entity is an operating entity for a HE STA; The method of claim 12 , wherein the second operating element is an operating element for an EHT STA.

16. The method of claim 12, wherein the second operating element includes a Deactivated Subchannel Bitmap Present subfield indicating whether or not to include a Deactivated Subchannel Bitmap subfield indicating the at least one unavailable channel of the BSS operating channel for the STA.

17. 17. The method of claim 16, wherein each bit of the Deactivated Subchannel Bitmap subfield indicates whether a corresponding unavailable channel is included in the BSS serving channels for the STA.

18. 17. The method of claim 16, wherein if the BSS operating channel for the STA does not include the at least one unavailable channel, the value of the Deactivated Subchannel Bitmap Present subfield is set to '0', a value indicating that the Deactivated Subchannel Bitmap subfield is not included.

19. The method comprises: The method further includes receiving a frame including a specific field indicating whether or not an operating parameter is changed from the AP, The method of claim 16, wherein the value of the particular field is increased when the operational parameter is changed.

20. 20. The method of claim 19, wherein the value of the particular field is increased if the inclusion or non-inclusion of the deactivated subchannel bitmap subfield is changed or if the inclusion or non-inclusion of the at least one unavailable channel is changed.

21. The method comprises: receiving a trigger frame instructing one or more STAs to transmit a PPDU; receiving a multi-STA Block ACK frame in response to the PPDU; 13. The method of claim 12, wherein, when at least one of the one or more STAs transmitting the PPDU in response to the trigger frame includes the legacy STA, the size of the Ack information for each of the at least one STA included in the multi-STA Block ACK frame is limited to a specific size or less.

22. 22. The method of claim 21, wherein the at least one STA among the one or more STAs that transmits the PPDU in response to the trigger frame includes the legacy STA, and the multi-STA Block ACK frame is transmitted via a resource unit (RU) individually allocated to the STA by the AP, the size of the Ack information is not limited to the specific size or less.

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