Method for transmitting and receiving data in wireless communication system and wireless communication terminal

Abstract

A method for transmitting a TBPPDU in a wireless communication system is disclosed.SOLUTION: The Non-APSTA may receive a frame for triggering transmission of a physicallayerprotocoldataunit (PPDU) from an AccessPoint (AP) and transmit a PPDU including a packetextension (PE) field for providing a processingtime for the PPDU in response to the frame. In this case, the frame may indicate a format for the PPDU transmitted in response to the frame, and the maximum value of the duration for the PE field may be different according to the format of the PPDU indicated by the frame.SELECTED DRAWING: Figure 30

Description

[Technical Field]

[0001] The present invention relates to a wireless communication system, and more particularly to a wireless communication method and a wireless communication terminal for determining a time for processing a wireless frame. [Background technology]

[0002] Recently, as the popularity of mobile devices has increased, wireless LAN technology, which can provide them with high-speed wireless Internet services, has been gaining attention. Wireless LAN technology is a technology that uses short-range wireless communication technology to enable mobile devices such as smartphones, smart pads, laptop PCs, portable multimedia players, embedded devices, etc. to connect to the Internet wirelessly at home, in business, or in specific service areas.

[0003] Since supporting early wireless LAN technology using the 2.4 GHz frequency band, IEEE (Institute of Electronics Engineers) 802.11 has since implemented or is currently developing various other technology standards. IEEE 802.11b uses the 2.4 GHz frequency band and supports a maximum communication speed of 11 Mbps. IEEE 802.11a, which was commercialized after IEEE 802.11b, uses the 5 GHz frequency band instead of the 2.4 GHz band, reducing the impact of interference compared to the significantly more congested 2.4 GHz frequency band, and uses OFDM technology to improve communication speeds to a maximum of 54 Mbps. 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 to achieve a maximum transmission speed of 54Mbps and is backward compatible, which has attracted considerable attention, but it also has an advantage over IEEE 802.11a in terms of communication distance.

[0004] IEEE 802.11n is a technical standard established to overcome the communication speed limitations that have been identified as a weakness of wireless LANs. IEEE 802.11n aims to increase network speed and reliability and extend the operating distance of wireless networks. Specifically, IEEE 802.11n supports high throughput (HT) of up to 540 Mbps and is based on MIMO (Multiple Inputs and Multiple Outputs) technology, which 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 WLAN adoption continues to grow and applications become more diverse, the need for new WLAN systems is emerging to support data throughput rates (Very High Throughput, VHT) higher than those supported by IEEE 802.11n. Among these, IEEE 802.11ac supports wide bandwidth (80MHz-160MHz) in the 5GHz frequency band. While the IEEE 802.11ac standard is defined only in the 5GHz band, initial 802.11ac chipsets are expected to support operation in the 2.4GHz band as well for backward compatibility with existing 2.4GHz products. Theoretically, this standard enables multi-station WLAN speeds of at least 1Gbps and maximum single-link speeds of at least 500Mbps. This is achieved by expanding the air interface concepts adopted in 802.11n, including wider radio frequency bandwidth (up to 160MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and denser modulation (up to 256QAM). Additionally, 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, making it suitable for streaming large amounts of data and high-bitrate video, such as uncompressed HD video. However, the 60GHz frequency band has the disadvantage of being 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 nearing completion as the successor to 802.11ac and 802.11ad in order 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, high-frequency-efficient communication must be provided both indoors and outdoors in the presence of a high density of stations and APs (Access Points), and various technologies are being developed to achieve this.

[0007] Additionally, development of new WLAN standards has begun to increase maximum transmission speeds to support new multimedia applications such as high-definition video and real-time gaming. IEEE 802.11be (Extremely High Throughput, EHT), the seventh generation WLAN standard, is currently under development with the goal of supporting transmission rates of up to 30 Gbps through wider bandwidth in the 2.4 / 5 / 6 GHz bands, increased spatial streams, and multi-AP cooperation. IEEE 802.11be proposes technologies such as a 320 MHz bandwidth, multi-link operation, multi-AP (multi-access point) operation, and hybrid automatic repeat request (HARQ) retransmission.

[0008] Multi-link operation operates in various forms depending on its operation method and implementation method. In this case, problems that did not occur in conventional IEEE 802.11-based WLAN communication operations may occur, so a detailed definition of the operation method for multi-link operation is required.

[0009] On the other hand, the art that forms 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] As described above, an object of the present invention is to provide an ultra-high speed wireless LAN service for new multimedia applications.

[0011] Another object of the present invention is to provide a method and apparatus for including in a radio frame a field for ensuring processing time in a receiving device when transmitting and receiving a radio frame.

[0012] Another object of the present invention is to provide a method and apparatus for determining the duration of a field to ensure processing time for a receiving device.

[0013] Another object of the present invention is to provide a method and apparatus for determining the field duration differently depending on specific conditions in order to ensure processing time for a receiving device.

[0014] Another object of the present invention is to provide a method for determining a field duration for ensuring processing time in a receiving device based on a frame modulation method, a resource unit size, a frame format, and / or the number of streams.

[0015] The technical problems to be solved by the present specification are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Means for solving the problem]

[0016] A terminal of a wireless communication system includes a communication module; and a processor that controls the communication module, wherein the processor receives a frame that triggers transmission of a physical layer protocol data unit (PPDU) from an access point (AP), and transmits a PPDU in response to the frame, the PPDU including a packet extension (PE) field for providing a processing time for the PPDU, the frame indicating a format for the PPDU transmitted in response to the frame, and a maximum value of a duration for the PE field differs depending on the format of the PPDU indicated by the frame.

[0017] In addition, in the present invention, when the format of the PPDU indicated by the frame is HE (High Efficiency) PPDU, the maximum value of the duration for the PE field is a first value, and when the format of the PPDU indicated by the frame is EHT (Extremely High Throughput) PPDU, the maximum value of the duration for the PE field is a second value.

[0018] In the present invention, the first value is "16 us" and the second value is "20 us".

[0019] Further, in the present invention, the processor receives an operation element from the AP, the operation element including a default PE duration subfield indicating the duration for the PE field, and when a value of a control identifier (ID) subfield included in the frame indicates TRS (Triggered Response Scheduling) for triggering transmission of the PPDU, if the format of the PPDU is indicated as EHT PPDU by the frame and the maximum value of the duration indicated by the default PE duration subfield is different from the maximum value of the duration when the format of the PPDU is indicated as EHT PPDU by the frame, the maximum value for the duration of the PE field is determined by the default PE duration subfield.

[0020] In addition, in the present invention, when the value of a control identifier subfield included in the frame indicates TRS (Triggered response scheduling) for triggering the transmission of a PPDU to another STA, the values ​​of each of the multiple subfields included in the frame used to calculate the duration of the PE field are set so that the duration of the PE field calculated using the multiple subfields is identical to the duration of the PE field of the PPDU to the other STA.

[0021] In addition, in the present invention, the processor receives an action element from the AP, and the action element includes an EHT default PE duration subfield indicating whether the maximum duration value for the PE field of the EHT PPDU is the same as the maximum duration value for the PE field of the HE PPDU.

[0022] Also, in the present invention, when the EHT Default PE Duration subfield indicates that the maximum value of the duration for the PE field of the EHT PPDU is not the same as the maximum value of the duration for the PE field of the HE PPDU, the duration for the PE field indicated by the EHT Default PE Duration subfield is "20us".

[0023] In addition, in the present invention, when the PPDU is modulated with 4096-QAM, or the number of spatial streams is 8 or more, or the channel bandwidth is 320 MHz, and the size of the resource unit (RU) allocated for transmitting the PPDU is 2 x 996 or more, the maximum value of the duration of the PE field is "20 us".

[0024] The present invention also provides a method including the steps of receiving a frame from an AP (Access Point) that triggers transmission of a PPDU (Physical Layer Protocol Data Unit); and transmitting a PPDU in response to the frame, the PPDU including a PE (Packet Extension) field for providing a processing time for the PPDU, wherein the frame indicates a format for the PPDU transmitted in response to the frame, and the maximum value of the duration for the PE field varies depending on the format of the PPDU indicated by the frame. [Effects of the Invention]

[0025] According to one embodiment of the present invention, radio frames can be efficiently signaled.

[0026] Furthermore, according to an embodiment of the present invention, it is possible to increase the overall resource utilization rate in a contention-based channel access system and improve the performance of a WLAN system.

[0027] Furthermore, according to one embodiment of the present invention, by including a field for processing time in the frame, it is possible to secure time for the receiving device to process the frame and send a response.

[0028] In addition, according to one embodiment of the present invention, the field duration for the frame processing time is determined based on the frame modulation method, the resource unit size, the frame format, and / or the number of streams, thereby efficiently securing the frame processing time.

[0029] 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 explanation of the drawings]

[0030] [Figure 1] 1 is a diagram showing a wireless LAN system according to an embodiment of the present invention. [Figure 2] FIG. 10 is a diagram showing a wireless LAN system according to another embodiment of the present invention. [Figure 3] FIG. 2 is a diagram showing the configuration of a station according to an embodiment of the present invention. [Figure 4] FIG. 2 is a diagram illustrating a configuration of an access point according to an embodiment of the present invention. [Figure 5] 1 is a diagram illustrating a process in which a STA establishes 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 various Extremely High Throughput (EHT) Physical Protocol Data Unit (PPDU) formats and methods for indicating the same according to an embodiment of the present invention. [Figure 9] 1 is a diagram illustrating a multi-link device according to an embodiment of the present invention. [Figure 10] FIG. 10 is a diagram illustrating an example of a TID-to-link mapping method according to one embodiment of the present invention. [Figure 11] FIG. 10 is a diagram illustrating an example of a multi-link NAV setting operation according to one embodiment of the present invention. [Figure 12] FIG. 10 is a diagram illustrating yet another example of a multi-link NAV setting operation according to one embodiment of the present invention. [Figure 13] FIG. 1 is a diagram illustrating an example of BSS classification and operations based thereon according to an embodiment of the present invention. [Figure 14]1 illustrates 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 an 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] 10 illustrates an example of a packet extension (PE) field for providing processing time according to an embodiment of the present invention. [Figure 20] 10 illustrates an example of a High Efficiency (HE) operation element and a default PE duration subfield according to an embodiment of the present invention. [Figure 21] 10 illustrates an example of a method for setting the duration of a PE field according to an embodiment of the present invention. [Figure 22] 10 illustrates yet another example of a method for configuring UL MU operation and PE field duration according to an embodiment of the present invention. [Figure 23] 10 illustrates yet another example of a method for configuring UL MU operation and PE field duration according to an embodiment of the present invention. [Figure 24] 10 illustrates yet another example of a method for configuring UL MU operation and PE field duration according to an embodiment of the present invention. [Figure 25] 10 illustrates an example of a method for setting a CS Required subfield according to an embodiment of the present invention. [Figure 26] 10 illustrates an example of a CS Required subfield configuration and UL MU operation according to an embodiment of the present invention. [Figure 27] 10 illustrates yet another example of the configuration of the CS Required subfield and the UL MU operation according to an embodiment of the present invention. [Figure 28] 10 illustrates an example of a method for setting a PE field when using an A (aggregated)-PPDU according to an embodiment of the present invention. [Figure 29] 10 illustrates an example of a method for indicating the format of a TB PPDU according to an embodiment of the present invention. [Figure 30] 10 is a flowchart illustrating an example of an operation of a terminal according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] The terms used in this specification are generally used as widely as possible, taking into consideration the functions of the present invention. However, these may vary depending on the intentions of engineers in the relevant technical field, customs, or the emergence of new technologies. In addition, in certain cases, the applicant may have arbitrarily selected terms, and in such cases, the meanings thereof will be described in the relevant description of the invention. Therefore, it is made clear that the terms used in this specification should be interpreted not simply as names of terms, but based on the substantive meanings of the terms and the overall content of this specification.

[0032] Throughout this specification, when a component is referred to as being "connected" to another component, this includes not only when the component is "directly connected" to the other component, but also when the component is "electrically connected" to the other component via another component therebetween. Furthermore, when a component is referred to as "comprising" a specific component, this does not mean that the component excludes the other component, but that the component may further include the other component, unless otherwise specified. Additionally, limitations such as "greater than" or "less than" based on a specific critical value may be appropriately substituted with "exceeds" or "less than," respectively, depending on the embodiment. Hereinafter, in the present invention, the terms "field" and "subfield" may be used interchangeably.

[0033] FIG. 1 is a diagram showing a wireless LAN system according to an embodiment of the present invention.

[0034] A wireless LAN system includes one or more Basic Service Sets (BSSs), which are a set of devices that can synchronize and communicate with each other. Generally, BSSs are classified into infrastructure BSSs and independent BSSs (IBSSs), and Figure 1 shows an infrastructure BSS.

[0035] As shown in FIG. 1, infrastructure BSSs BSS1 and BSS2 include one or more stations STA1, STA2, STA3, STA4, and STA5, access points AP-1 and AP-2 that are stations providing distribution services, and a distribution system DS that connects multiple access points AP-1 and AP-2.

[0036] A station (STA) is any device that includes a medium access control (MAC) and a physical layer interface for a wireless medium according to the IEEE 802.11 standard. In a broad sense, the term "station" encompasses 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 may further include a user interface and a display unit, depending on the embodiment. The processor generates frames to be transmitted over a wireless network, processes frames received over 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 over the wireless network for the station. In this specification, the term "terminal" encompasses user equipment (UE).

[0037] An access point (AP) is an entity that provides a connection to a distribution system (DS) via a wireless medium for associated stations. In an infrastructure BSS, communication between non-AP stations is generally performed via the AP. However, if a direct link is established, direct communication is also possible between non-AP stations. Meanwhile, in the present invention, the term AP is used as a concept including a personal BSS coordination point (PCP), but in a broader sense, it also includes 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, an AP is also referred to as a base wireless communication terminal, but in a broader sense, the term 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 for communication with multiple wireless communication terminals.

[0038] A plurality of infrastructure BSSs are connected to each other via a distribution system DS, and the plurality of BSSs connected via the distribution system are called an Extended Service Set (ESS).

[0039] 2 is a diagram showing an independent BSS, which is a wireless LAN system according to another embodiment of the present invention. In the embodiment of FIG. 2, the same or corresponding parts as those in the embodiment of FIG. 1 will not be described again.

[0040] BSS3 shown in Figure 2 is an independent BSS and does not include an AP, so none of the stations (STA6, STA7) are 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.

[0041] 3 is a block diagram showing the configuration of a station 100 according to an embodiment of the present invention. As shown, 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.

[0042] First, the communication unit 120 transmits and receives wireless signals such as WLAN packets and may be incorporated into or external to 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 using 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 above 7.125 GHz and a communication module using a frequency band below 7.125 GHz. Each communication module may perform wireless communication with an AP or an external station based on the WLAN standard of the frequency band supported by the communication module. The communication unit 120 may operate only one communication module at a time or multiple communication modules simultaneously, depending on the performance and requirements of the station 100. When the station 100 includes multiple communication modules, each communication module may be provided independently, or multiple modules may be integrated into a single chip. In the embodiment of the present invention, the communication unit 120 may represent a radio frequency (RF) communication module that processes RF signals.

[0043] 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 instructions from the processor 110 using various output means.

[0044] The display unit 150 then outputs an image on a display screen. The display unit 150 outputs various display objects, such as content generated by the processor 110 or a user interface based on a control command from the processor 110. The memory 160 also stores control programs and various data used by the station 100. The control programs include a connection program required for the station 100 to connect to an AP or an external station.

[0045] 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 the transmission and reception of data between the units. According to an embodiment of the present invention, the processor 110 executes a program for connection with an AP stored in the memory 160 and receives a communication setup message transmitted by the AP. The processor 110 also reads information about the station 100's preferences contained in the communication setup message and requests connection to the AP based on the information about the station 100's preferences. The processor 110 of the present invention may refer to a main control unit of the station 100, or, depending on the embodiment, may refer to a control unit for individually controlling some components of the station 100, such as the communication unit 120. That is, the processor 110 may be a modem that modulates and demodulates wireless signals transmitted and received by the communication unit 120, or a modulator and / or demodulator. The processor 110 controls various operations for transmitting and receiving wireless signals in the station 100 according to an embodiment of the present invention. A detailed embodiment of this will be described later.

[0046] The station 100 shown in FIG. 3 is a block diagram according to an embodiment of the present invention, and the separate blocks indicate the logically separated elements of the device. Therefore, the above-described device elements may be mounted on a single chip or multiple chips depending on the device design. For example, the processor 110 and the communication unit 120 may be integrated into a single chip or may be mounted on separate chips. Furthermore, in embodiments 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.

[0047] 4 is a block diagram showing the configuration of an AP 200 according to an embodiment of the present invention. As shown, 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, duplicated descriptions 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.

[0048] 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 multiple 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, 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz. Preferably, the AP 200 may include a communication module using a frequency band above 7.125 GHz and a communication module using a frequency band below 7.125 GHz. 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 multiple communication modules simultaneously, depending on the performance and requirements of the AP 200. In the embodiment of the present invention, the communication unit 220 may represent an RF (Radio Frequency) communication module that processes RF signals.

[0049] The memory 260 stores control programs used by the AP 200 and various data associated therewith. These control programs include a connection program that manages station connections. The processor 210 also controls each unit of the AP 200 and controls data transmission and reception between the units. According to an embodiment of the present invention, the processor 210 executes a program for connecting with a station stored in the memory 260 and transmits a communication setup message to one or more stations. The communication setup message includes information about connection preferences for each station. The processor 210 also performs connection setup in response to a station connection request. According to an embodiment, the processor 210 is a modem or a modulator / demodulator that modulates and demodulates wireless signals transmitted and received by the communication unit 220. The processor 210 controls various operations for transmitting and receiving wireless signals by the AP 200 according to an embodiment of the present invention. A detailed embodiment of this will be described later.

[0050] FIG. 5 is a diagram illustrating a process in which a STA establishes a link with an AP.

[0051] 5, a link between the STA 100 and the AP 200 is established through three steps: scanning, authentication, and association. First, the scanning step is a step in which the STA 100 acquires connection information for the BSS operated by the AP 200. There are two scanning methods: a passive scanning method in which the STA 100 acquires information using only a beacon message S101 periodically transmitted by the AP 200, 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.

[0052] The STA 100 that successfully receives wireless connection information in the scanning step transmits an authentication request (S107a), receives an authentication response from the AP 200, and performs the authentication step (S107b). After the authentication step is performed, the STA 100 transmits an association request (S109a), receives an association response from the AP 200, and performs the association step (S109b). In this specification, association basically means wireless association, but the present invention is not limited to this, and association in a broad sense includes both wireless association and wired association.

[0053] Meanwhile, an 802.1X-based authentication step S111 and an IP address acquisition step S113 via DHCP are additionally performed. In Fig. 5, server 300 is a server that processes 802.1X-based authentication with STA 100, and may be physically connected to AP 200 or may exist as a separate server.

[0054] FIG. 6 is a diagram showing a Carrier Sense Multiple Access (CSMA) / Collision Avoidance (CA) method used in wireless LAN communication.

[0055] A terminal performing WLAN communication performs carrier sensing to check whether a channel is occupied before transmitting data. If a wireless signal above a certain strength 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 a signal is detected is called the CCA threshold. If a wireless signal above 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 with a strength below the CCA threshold is detected, the channel is determined to be idle.

[0056] If the channel is determined to be idle, each terminal with data to transmit performs a backoff procedure after an Inter Frame Space (IFS), such as an Arbitration IFS (AIFS) or a PCF IFS (PIFS), depending on the status of each terminal. In some embodiments, the AIFS is used as a configuration replacing the conventional DCF IFS (DIFS). Each terminal waits while decreasing a slot time by a random number determined for the corresponding terminal during the idle interval of the channel, and a terminal that has exhausted all slot times attempts to access the corresponding channel. The period during which each terminal performs the backoff procedure is called a contention window period.

[0057] If a specific terminal successfully accesses the channel, it transmits data over 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 new random numbers 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. At this time, each terminal performs the backoff procedure from the slot time remaining in the previous contention window period. In this way, terminals communicating over a wireless LAN can avoid collisions with each other on a specific channel.

[0058] Hereinafter, in the present invention, a terminal may be referred to as 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 may be referred to as an AP.

[0059] <Examples of various PPDU formats>

[0060] Figure 7 shows examples of various standard generation PPDU (PLCP Protocol Data Unit) formats. More specifically, Figure 7(a) shows an example of a legacy PPDU format based on 802.11a / g, Figure 7(b) shows an example of an HE PPDU format based on 802.11ax, and Figure 7(c) shows an example of a non-legacy PPDU (i.e., EHT PPDU) format based on 802.11be. Also, Figure 7(d) shows detailed field configurations of L-SIG and RL-SIG commonly used in the PPDU formats.

[0061] 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.

[0062] Referring to FIG. 7(b), the preamble of the HE PPDU further includes a Repeated Legacy Short Training field (RL-SIG), a High Efficiency Signal A field (HE-SIG-A), a High Efficiency Signal B field (HE-SIG-B), a High Efficiency Short Training field (HE-STF), and a High Efficiency Long Training field (HE-LTF) 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 vary depending on the HE PPDU format. For example, HE-SIG-B may be used only in the HE MU PPDU format.

[0063] Referring to FIG. 7(c), the preamble of the EHT PPDU further includes a Repeated Legacy Short Training field (RL-SIG), a Universal Signal field (U-SIG), an Extremely High Throughput Signal A field (EHT-SIG-A), an Extremely High Throughput Signal B field (EHT-SIG-A), an Extremely High Throughput Short Training field (EHT-STF), and an Extremely High Throughput Long Training field (EHT-LTF) 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 may be referred to as an EHT preamble. The specific configuration of the non-legacy preamble may vary depending on the EHT PPDU format. For example, EHT-SIG-A and EHT-SIG-B may be used only in some EHT PPDU formats.

[0064] The L-SIG field included in the PPDU preamble is configured with a total of 64 subcarriers using 64 FFT OFDM. Of these, 48 subcarriers, excluding guard subcarriers, DC subcarriers, and pilot subcarriers, are used for L-SIG data transmission. BPSK and Rate=1 / 2 MCS (Modulation and Coding Scheme) are applied to the L-SIG, so it can contain a total of 24 bits of information. Figure 7(d) shows the 24-bit information structure of the L-SIG.

[0065] 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, or 54 Mbps, which is a combination of a modulation scheme such as BPSK, QPSK, 16-QAM, or 64-QAM and a code rate such as 1 / 2, 2 / 3, or 3 / 4. The combined information in the L_RATE and L_LENGTH fields indicates the total length of the PPDU. In a non-legacy PPDU format, the L_RATE field is set to the minimum rate of 6 Mbps.

[0066] The unit of the L_LENGTH field is bytes, and a total of 12 bits are allocated, allowing a maximum of 4095 to be signaled. 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.

[0067] First, a legacy or non-legacy terminal interprets the length of the corresponding PPDU using the L_LENGTH field 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 the 64FFT. Therefore, by adding the 3 bytes corresponding to the SVC field and Tail field to the L_LENGTH field value and dividing this by 3 bytes, which is the transmission amount of one symbol, the number of 64FFT reference symbols after the L-SIG is obtained. The obtained number of symbols is multiplied by 4 us, which is one symbol duration, and then 20 us, which is required to transmit the L-STF, L-LTF, and L-SIG, to obtain the length of the corresponding PPDU, i.e., the reception time (RXTIME). This can be expressed mathematically as shown in Equation 1 below.

[0068]

number

[0069] At this time,

number

[0070]

number

[0071] 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.

[0072]

number

[0073] 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.

[0074] Referring to Figure 7(e), the U-SIG (Universal SIG) field remains in the EHT PPDU and subsequent generation WLAN PPDUs, and serves to distinguish which generation of PPDU it is, including 11be. The U-SIG is two 64FFT-based OFDM symbols and can transmit a total of 52 bits of information. Of these, 43 bits excluding 9 bits of CRC / tail are roughly divided into a VI (Version Independent) field and a VD (Version Dependent) field.

[0075] The VI bit will maintain its current bit configuration, so even if a subsequent generation PPDU is defined, current 11be UEs can obtain information about the PPDU from the VI field of the PPDU. To this end, the VI field consists of the PHY version, UL / DL, BSS color, TXOP, and Reserved fields. The PHY version field is 3 bits long and serves to sequentially distinguish between 11be and subsequent generations of WLAN standards. 11be has a value of 000b. The UL / DL field identifies whether the PPDU is an uplink or downlink PPDU. The BSS color represents a BSS identifier defined in 11ax and has a value of 6 or more bits. The TXOP represents the transmit opportunity duration (Transmit Opportunity Duration) transmitted in the MAC header. By adding it to the PHY header, the length of the TXOP containing the PPDU can be inferred without decoding the MPDU, and has a value of 7 or more bits.

[0076] The VD field, which is signaling information useful only for 11be version PPDUs, may consist of fields commonly used in any PPDU format, such as the PPDU format and BW, as well as fields defined differently for each PPDU format. The PPDU format is a separator that distinguishes between EHT SU (Single User), EHT MU (Multiple User), EHT TB (Trigger-based), and EHT ER (Extended Range) PPDUs. The BW field broadly signals five basic PPDU BW options: 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), as well as various remaining PPDU BWs formed by preamble puncturing. After signaling at 320 MHz, a portion of 80 MHz may be punctured. In addition, the punctured and modified channel shape may be signaled directly in the BW field, or may be signaled using both the BW field and a field that appears after the BW field (for example, 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.

[0077] The fields located after the BW field vary depending on the type and format of the PPDU. MU PPDUs and SU PPDUs may be signaled using the same PPDU format, and a field for distinguishing between MU PPDUs and SU PPDUs may be located before the EHT-SIG field, requiring additional signaling. Both SU PPDUs and MU PPDUs include an EHT-SIG field, but some fields not required for the SU PPDU may be compressed. In this case, the information of the compressed fields may be omitted or may have a reduced size compared to the size of the original fields included in the MU PPDU. For example, the SU PPDU may have a different configuration, such as the common fields of the EHT-SIG being omitted or replaced, or the user-specific fields being replaced or reduced to one.

[0078] Alternatively, the SU PPDU may further include a compression field indicating whether or not it is compressed, and some fields (such as the RA field) may be omitted depending on the value of the compression field.

[0079] When a portion 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). In the case of an 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 sent to it. 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 in the EHT-SIG field and / or the MCS, which is the modulation method. The EHT-SIG field may include information on the size and location of the RU assigned to each user.

[0080] In the case of an 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 efficiently receive the SU PPDU only by recognizing punctured RUs in between. Therefore, the AP can transmit the SU PPDU including information on punctured RUs among the RUs assigned to the STA (e.g., puncturing pattern of the RUs). That is, in the case of an 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 can signal the type of discontinuous channels appearing within the bandwidth.

[0081] The type of 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, since the SU PPDU is a PPDU transmitted only to a single UE, the STA can recognize its allocated bandwidth from the BW field included in the PPDU and can recognize punctured resources within 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 excluding specific channels of the punctured resource units. In this case, multiple RUs allocated to the STA may be configured with different frequency bands or tones.

[0082] The reason why only limited discontinuous channel types are signaled is to reduce the signaling overhead of the SU PPDU. Since puncturing can be performed for each 20 MHz subchannel, if puncturing is performed on a BW having multiple 20 MHz subchannels, such as 80, 160, or 320 MHz, in the case of 320 MHz, the discontinuous channel type (when only the end 20 MHz is punctured and considered discontinuous) must be signaled by expressing whether or not each of the remaining 15 20 MHz subchannels excluding the primary channel is in use. Using 15 bits to signal the discontinuous channel type for single-user transmission can result in excessive signaling overhead when considering the low transmission rate of the signaling part.

[0083] This 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 primary 160 MHz and secondary 160 MHz puncturing types in the 320 MHz BW configuration of the SU PPDU.

[0084] In addition, one embodiment of the present invention proposes a method of varying the PPDU configuration indicated by the preamble puncturing BW value according to the PPDU format signaled in the PPDU format field. Assuming the length of the BW field is 4 bits, in the case of an EHT SU PPDU or TB PPDU, an EHT-SIG-A symbol of one symbol may be further signaled after the U-SIG, or no EHT-SIG-A may be signaled at all. Taking this into consideration, up to 11 puncturing modes must be signaled using only the BW field of the U-SIG. However, in the case of an EHT MU PPDU, an EHT-SIG-B symbol is further signaled after the U-SIG, so up to 11 puncturing modes may be signaled in a different manner than in the SU PPDU. In the case of an EHT ER PPDU, the BW field can be set to 1 bit to signal whether the PPDU uses a 20 MHz or 10 MHz bandwidth.

[0085] Figure 7(f) shows the format-specific field configuration of the VD field when the PPDU format field of the U-SIG indicates an EHT MU PPDU. For an MU PPDU, SIG-B, a signaling field for simultaneous reception by multiple users, is required. SIG-B may be transmitted after the U-SIG without a separate SIG-A. For this purpose, the U-SIG must signal information for decoding SIG-B. These fields include the SIG-B MCS, SIG-B DCM, number of SIG-B symbols, SIG-B compression, and number of EHT-LTF symbols.

[0086] FIG. 8 illustrates an example of various Extremely High Throughput (EHT) Physical Protocol Data Unit (PPDU) formats and methods for indicating the same according to an embodiment of the present invention.

[0087] 8, a PPDU may be configured with a preamble and a data portion, and the format of one type, EHT PPDU, may be distinguished by a U-SIG field included in the preamble. Specifically, whether the format of the PPDU is EHT PPDU may be indicated based on a PPDU format field included in the U-SIG field.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 8(d) shows an example of an EHT ER SU PPDU format used for single-user transmission with STAs in an extended range. The EHT ER SU PPDU may be used for single-user transmission with STAs in a wider range than the EHT SU PPDU described in FIG. 8(a), and the U-SIG field may be repeated on the time axis.

[0092] The EHT MU PPDU described in (c) of Figure 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 transmitted PPDU to the STA through the user specific field of the EHT-SIG-B. 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.

[0093] Specifically, the resource unit allocation (RA) field of the HE-SIG-B field included in the HE MU PPDU may include information regarding the configuration of resource units (e.g., the division type of resource units) in a specific bandwidth (e.g., 20 MHz) on the frequency axis. That is, the RA field may indicate the configuration of resource units divided by the bandwidth for transmitting the HE MU PPDU so that the STA can receive the PPDU. Information about 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.

[0094] For example, among the multiple divided resource units, the user field corresponding to at least one resource unit used for data transmission may include the AID of the receiver or sender, and the user field corresponding to the remaining resource units not used for data transmission may include a previously set null STA ID.

[0095] 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, an EHT SU PPDU and an EHT MU PPDU can be indicated by the same value using the U-SIG PPDU format subfield. In this case, the EHT SU PPDU and the EHT MU PPDU can be distinguished depending on the number of STAs receiving the PPDU. For example, a PPDU received by only one STA may be identified as an EHT SU PPDU, and when the number of STAs is set so that two or more STAs can receive the PPDU, it may be identified as an EHT MU PPDU. In other words, two or more PPDU formats shown in FIG. 8 can be indicated using the same subfield value.

[0096] In addition, some of the fields or some information of the fields shown in Figure 8 may be omitted, and such a case where some of the fields or some information of the fields is omitted can be defined as a compression mode or a compressed mode.

[0097] FIG. 9 is a diagram illustrating a multi-link device according to an embodiment of the present invention.

[0098] Referring to FIG. 9, the concept of a device to which one or more STAs are affiliated may be defined. As another example, according to an embodiment of the present invention, a device to which more than one STA (i.e., two or more) is affiliated may be defined. In this case, a device may be a logical concept. Therefore, such a device to which one or more STAs are affiliated may be referred to as a multi-link device (MLD), a multi-band device, or a multi-link logical entity (MLLE).

[0099] Alternatively, the above conceptual device can be called a multi-link entity (MLE). Also, an MLD may have one MAC medium access control service access point (SAP) to a logical link control (LLC), and an MLD may have one MAC data service.

[0100] 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 in different frequency bands, such as 2.4 GHz, 5 GHz, and 6 GHz. This allows MLD to gain benefits in channel access and improve overall network performance. While existing WLANs operate on a single link, MLD operation can use multiple links to obtain more channel access opportunities, or allow STAs to operate efficiently on multiple links taking into account channel conditions.

[0101] Also, if the STA affiliated with the MLD is an AP, the MLD to which the AP is affiliated may be an AP MLD, but if the STA affiliated with the MLD is a non-AP STA, the MLD to which the non-AP is affiliated may be a non-AP MLD.

[0102] 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 the LLC (Logical Link Control) 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 a separate link. An STA MLD may be a device including one or more non-AP STAs and connected to a higher layer via one interface.

[0103] That is, the STA MLD may be connected to the LLC layer via one interface. Multiple STAs included in the STA MLD may share some functions at the MAC layer. The STA MLD may also be called a non-AP MLD. The AP MLD and STA MLD can perform multi-link operation, communicating using multiple individual links. That is, if the AP MLD includes multiple APs, each AP can configure a separate link and transmit and receive frames using multiple links with each UE included in the STA MLD. Each link can operate in the 2.4 GHz, 5 GHz, or 6 GHz band, and each link can perform bandwidth extension. For example, if the AP MLD configures one link in the 2.4 GHz band and two links in the 5 GHz band, the 2.4 GHz band can transmit frames at a bandwidth of 40 MHz using the bandwidth extension method, and each link using the 5 GHz band can transmit frames at a maximum bandwidth of 320 MHz using discontinuous bandwidth.

[0104] Meanwhile, due to interference issues within the device, the AP MLD or STA MLD may prevent one terminal in the MLD from receiving while another terminal is transmitting. This 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. Alternatively, STR operation is not possible for some links of the AP MLD. An STR-capable terminal MLD may be connected to an AP MLD, or an STR-incapable MLD may be connected to some or all links. Furthermore, an AP included in an AP MLD may also be connected to terminals (e.g., IEEE 802.11a / b / g / n / ac / ax terminals) that do not belong to the MLD.

[0105] The AP MLD and the STA MLD may perform a negotiation process for a multiple link usage operation during the scanning and connection process described in FIG. 5. For example, during the scanning process described in FIG. 5, an AP included in the AP MLD may transmit a beacon frame including an indicator indicating that a multiple link operation is available, the number of available links, and information on the number of available links. Alternatively, a terminal belonging to the STA MLD may transmit a probe request frame including an indicator indicating that a multiple link operation is available, and an AP belonging to the AP MLD may transmit a probe response frame including an indicator indicating that a multiple link operation is available. In this case, the AP may further transmit the number of available links, link information, etc. during the multiple link operation.

[0106] The STA MLD, which has confirmed whether the AP MLD is to operate multiple links 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 multiple link operation. At this time, the negotiation process for the multiple link operation can be performed during the connection process between an AP belonging to the AP MLD and a terminal belonging to the STA MLD. That is, a terminal (e.g., STA1) belonging to the STA MLD can send a connection request frame to an AP (e.g., AP1) belonging to the AP MLD, and can send an indicator indicating that the terminal's multiple link operation is available and a request indicator requesting the terminal to perform the multiple link operation. The AP receiving the connection request frame from the terminal can check the indicator requesting the multiple link operation, and if the AP is capable of the multiple link operation, can send a connection response frame to the terminal that allows the multiple link operation, including link information to be used for the multiple link operation and parameters used for each link. The parameters for the multi-link operation may include one or more of the bandwidth of each link to be used, a bandwidth expansion direction, a Target Beacon Transmission Time (TBTT), and whether or not to perform STR operation. After the connection process, the AP MLD and the STA MLD, which have confirmed the use of the multi-link operation 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 UEs included in the STA MLD.

[0107] 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, an MLD including APs AP1, AP2, and AP3 may be called an AP MLD, and an MLD including non-AP STAs non-AP STA1, non-AP STA2, and non-AP STA3 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 Links 1 to 3.

[0108] According to an embodiment of the present invention, a 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 over multiple links, multi-link setup must be performed first. 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 multiple links. The capability information may include information on whether a STA included in the MLD can receive frames over one link while another STA included in the MLD can transmit frames over another link. 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 links included in the MLD. The capability information may also include information on available links or operating channels. The multi-link setup may be set up through negotiation between peer STAs, and a multi-link operation may be set up over a single link.

[0109] According to one embodiment of the present invention, a mapping relationship may exist between a TID and an MLD link. For example, when a TID and a link are mapped, the TID may be transmitted on the mapped link. The mapping between a TID and a link may be direction-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 a TID and a link. For example, the mapping between a TID and a link may basically be such that all TIDs are mapped to a certain link.

[0110] FIG. 10 is a diagram illustrating an example of a TID-to-link mapping method according to an embodiment of the present invention.

[0111] Referring to Figure 10, there may be a mapping relationship between TIDs and links as described in Figure 9. In addition, in the present invention, the mapping relationship between TIDs and links may be referred to as TID-to-link mapping, TID-to-link mapping, TID mapping, link mapping, etc. The TID may be a traffic identifier. The TID may also be an ID (identifier) ​​that classifies traffic, data, etc. to support quality of service (QoS).

[0112] The TID may be an ID used or assigned in a layer higher than the MAC layer. The TID may indicate traffic categories (TC) or traffic streams (TS). The TID may have 16 possible values, for example, values ​​from 0 to 15. Individual TID values ​​may be used depending on an access policy, channel access, or medium access method. For example, when EDCA (HCF (hybrid coordination function) connection-based channel access, enhanced distributed channel access) is used, the possible TID values ​​may be 0 to 7. When EDCA is used, the TID value may indicate user priority (UP), and the UP may be related to TC or TS. The UP may be a value assigned in a layer higher than the MAC. When HCCA (HCF controlled channel access) or SPCA is used, the possible TID values ​​may be 8 to 15. 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.

[0113] 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 a set of EDCA parameters may be used for channel association. An AC may be used in a QoS STA.

[0114] The AC value 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. Furthermore, AC_BK, AC_BE, AC_VI, and AC_VO may be further subdivided. For example, AC_VI may be further subdivided into AC_VI primary and AC_VI alternate. Furthermore, AC_VO may be further subdivided into AC_VO primary and AC_VO alternate. Furthermore, UP values ​​or TID values ​​may be mapped to AC values. For example, UP values ​​or TID values ​​of 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, 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 alternate, AC_VI primary, AC_VO primary, and AC_VO alternate, respectively. UP values ​​or TID values ​​1, 2, 0, 3, 4, 5, 6, and 7 may have increasing priorities. That is, 1 may be a lower priority and 7 may be a higher priority. Therefore, the order of increasing priorities may be AC_BK, AC_BE, AC_VI, and AC_VO. AC_BK, AC_BE, AC_VI, and AC_VO may correspond to ACI (AC index) 0, 1, 2, and 3, respectively.

[0115] Therefore, there may be a relationship between a TID and an AC. Therefore, the TID-to-link mapping of the present invention may be a mapping relationship between an AC and a link. Also, in the present invention, when a TID is mapped, it may also mean that an AC is mapped, and vice versa.

[0116] According to one embodiment of the present invention, a TID may be mapped to each link of a multi-link. For example, there may be a mapping of which link among multiple links a specific TID or a specific AC is allowed to transmit or receive on. Such mapping may be defined separately for each direction of the link. As described above, a default setting may exist for the mapping between TIDs and links. For example, the mapping between TIDs and links may basically map all TIDs to a certain link. According to one embodiment, at a specific time, a certain TID or a certain AC may be mapped to at least one link. Furthermore, management frames or control frames may be transmitted on all links.

[0117] In the present invention, data frames corresponding to TIDs or ACs that are mapped to either direction of the link may be transmitted, and data frames corresponding to TIDs or ACs that are not mapped to either direction of the link may not be transmitted.

[0118] 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. Alternatively, 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.

[0119] TID-to-link mapping can provide QoS services. For example, by mapping a high-priority AC and TID to a link with good channel conditions or few STAs, data for that AC and TID can be transmitted quickly. Alternatively, TID-to-link mapping can help STAs on a specific link save power (or enter a doze state).

[0120] 10, there may be an AP MLD including AP1 and AP2. There may also be a Non-AP MLD including STA1 and STA2. There may also be multiple links, Link1 and Link2, in the AP MLD. AP1 and STA1 may be associated via Link1, and AP2 and STA2 may be associated via Link2.

[0121] 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 AC.

[0122] For example, all TIDs and all ACs may be mapped to Link1, a link for transmission from AP1 to STA1, and Link1, a link for transmission from STA1 to AP1. Furthermore, only AC_VO or a TID corresponding to AC_VO may be mapped to Link2, a link for transmission from STA2 to AP2. Furthermore, only data of mapped TIDs and / or ACs can be transmitted on the link. Furthermore, data of TIDs or ACs not mapped to a link cannot be transmitted on the link.

[0123] FIG. 11 is a diagram illustrating an example of a multi-link NAV setting operation according to an embodiment of the present invention.

[0124] The simultaneous transmit and receive (STR) operation of MLD may be limited, which may be related to the frequency spacing between multiple links operating in a multi-link.

[0125] Therefore, according to an embodiment of the present invention, simultaneous transmission or reception is restricted when the spacing between links is m MHz, and simultaneous transmission or reception may not be restricted when the spacing between links is n MHz for n greater than m. This embodiment may be intended to solve the problem of simultaneous transmission or reception being restricted, and redundant description may be omitted. This embodiment may also be applied to MLDs that do not support STR.

[0126] According to an embodiment of the present invention, duration information may be shared between links operating as multiple links. As an example, 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. Alternatively, the signaling field may be the HE-SIG-A field described above. As another example, the duration information may be indicated by a Duration / ID field included in a MAC header. As another example, the duration information may be indicated by a Length field included in an L-SIG field. According to an example, the duration information indicated by the U-SIG field, HE-SIG-A, or Duration / ID field may be a value indicating the TXOP duration. According to an example, 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.

[0127] Furthermore, according to an embodiment of the present invention, it is possible to restrict transmission or channel access during a period based on period information shared between links. The method of restricting transmission or channel access may include setting a NAV. Alternatively, the NAV may be reset to resume transmission or channel access. 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 its NAV based on a frame (or PPDU) directed to another STA belonging to the MLD.

[0128] 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 on link 2 may be avoided 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 does not support STR. For example, when an inter-link NAV is set, the MLD that set the inter-link NAV does not need to transmit or connect channels on multiple links (or all links used by the MLD).

[0129] In addition to the intra-BSS NAV, a basic NAV may also 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).

[0130] Using a separate inter-link NAV may have advantages over not using an inter-link NAV in situations where the NAV setting is updated. For example, situations may arise where it is acceptable to reset the NAV set by another link. For example, if an inter-link NAV is set based on a certain frame (or PPDU), but it is determined that the frame (or PPDU) is not destined for the same MLD, it may be acceptable to reset the set inter-link NAV. Suppose there is an MLD operating 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 received on link 2. If the NAV for link 2 no longer needs to be maintained, resetting the NAV for link 1 would result in the loss of the NAV information set based on the frame received on link 1. If the inter-link NAV were used together with the NAV for each link, the NAV for each link would be maintained even if the inter-link NAV was reset, thereby resolving the above problem.

[0131] Although the embodiment of the present invention focuses on 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 channel connection or instructing the channel state to be busy. Furthermore, the embodiment is not limited to resetting the NAV and can also be applied to instructing the physical layer to continue channel connection or instructing the channel state to be idle. In this case, a primitive exchanged between the physical layer and the MAC layer may be used. Alternatively, a primitive exchanged between one STA and another STA in the MLD may be used. Alternatively, a primitive exchanged between one MAC layer and another MAC layer in the MLD may be used.

[0132] 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 terminate their channel access. As described above, channel access may be terminated based on the received duration information. However, due to the position of the field containing the duration information or the time required for decoding, there may be a time lag between the start of PPDU reception and the acquisition of the duration information. Therefore, accessing the channel and starting transmission during this time may lead to the above-mentioned problem. Therefore, according to an embodiment of the present invention, an STA in an MLD can terminate its channel access from the time another STA in the MLD starts receiving. Furthermore, after another STA in the MLD starts receiving, it can resume its channel access if it determines that the received frame is not intended for the other STA.

[0133] FIG. 12 is a diagram illustrating yet another example of a multi-link NAV setting operation according to an embodiment of the present invention.

[0134] FIG. 12 embodies the explanation of the specific method of the embodiment explained in FIG. 11, and the duplicated explanation may be omitted.

[0135] As described above, based on a frame or PPDU received by a STA belonging to the same MLD, other STAs belonging to the same MLD can suspend or resume their channel access or transmission. In the present invention, suspending channel access or transmission may include operations such as setting (updating) the NAV, determining the channel as busy, or suspending CCA. Furthermore, resuming channel access or transmission may include operations such as resetting the NAV, canceling the NAV setting, determining the channel as idle, or performing CCA. Hereinafter, these operations may be referred to as suspending and resuming channel access. Hereinafter, it may be described that STA1 and STA2 belong to the MLD and operate on Link1 and Link2, respectively. Furthermore, frames and PPDUs may be indicated interchangeably. Furthermore, the NAV in this case may be the intra-BSS NAV or the inter-link NAV, as described in FIG. 11.

[0136] According to an embodiment of the present invention, when STA1 begins to receive a frame, STA2 may suspend the channel connection. Furthermore, when STA1 acquires duration information from the L-SIG, STA2 may maintain the suspended channel connection. In this case, STA2 can determine that the suspended channel connection will last until the end of the frame received by STA1. Furthermore, if STA1 cannot reliably decode the L-SIG (if the L-SIG is invalid), STA2 can resume the channel connection.

[0137] In addition, 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 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 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.

[0138] Alternatively, STA1 may receive the 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. Alternatively, STA1 may not be able to successfully decode the U-SIG. In such cases, STA2 can resume channel connection.

[0139] 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.

[0140] Although the above description is directed 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-described operations can be performed.

[0141] Also, STA2 may receive a STA-ID from the EHT-SIG of the frame received by STA1. If the received STA-ID is an indicator that STA1 should receive, for example, if the STA-ID indicates STA1, the STA-ID 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.

[0142] Alternatively, STA1 may receive a STA-ID from the EHT-SIG of the received frame. 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. Alternatively, STA2 can resume the channel connection even if STA1 fails to successfully decode the EHT-SIG.

[0143] 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-described operation can be performed.

[0144] STA2 may also 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 that STA1 should receive, 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 suspended channel connection. In this case, 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.

[0145] Also, STA1 may have received the MAC header of the frame it received. If the RA or DA included in the received MAC header is an indicator that does not apply to STA1, for example, if the 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 channel connection. Alternatively, STA1 may not have received all of the MAC header. For example, STA1 may fail to receive all of the MPDUs included in the A-MPDU. In this case, STA2 can resume channel connection.

[0146] The channel connection suspension and resumption described in FIG. 12 may be performed in the decoding order 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 L-SIG, U-SIG, EHT-SIG, and MAC header may be decoded in this order (for EHT PPDUs). Alternatively, the L-SIG, HE-SIG-A, and MAC header may be decoded in this order (for HE SU PPDUs and HE TB PPDUs). Alternatively, the L-SIG, HE-SIG-A, HE-SIG-B, and MAC header may be decoded in this order (for HE MU PPDUs). Alternatively, the L-SIG and MAC header may be decoded in this order (for 11a / g PPDUs).

[0147] 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, an HE-SIG-B field, or the like. 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.

[0148] FIG. 13 is a diagram illustrating an example of BSS classification and operations based thereon according to an embodiment of the present invention.

[0149] According to one 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 a received frame or a received PPDU corresponds to a BSS to which the classifying STA belongs. Alternatively, classifying a BSS may mean an operation of classifying whether a received frame or a received PPDU is transmitted from a BSS to which the classifying STA belongs. Classifying a BSS may also include an operation of classifying whether a received frame or a received PPDU corresponds to a BSS to which the classifying STA does not belong. Alternatively, classifying a BSS may also mean an operation of classifying whether a received frame or a received PPDU is transmitted from a BSS to which the classifying STA does not belong. Classifying a BSS may also include an operation of classifying to which BSS a received frame or a received PPDU belongs. Alternatively, classifying a BSS may mean an operation of classifying from which BSS a received frame or a received PPDU is transmitted. According to one embodiment of the present invention, a BSS to which a classification STA belongs may be referred to as an intra-BSS. Alternatively, a BSS including a BSS to which a classification STA belongs may be referred to as an intra-BSS. Furthermore, a BSS that is not an intra-BSS may be referred to as an inter-BSS. Alternatively, a BSS that is not an intra-BSS may be an inter-BSS or an unclassified BSS. Alternatively, an inter-BSS may include an unclassified BSS. Furthermore, a BSS to which a classification STA does not belong may be referred to as an inter-BSS.

[0150] 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. Furthermore, 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. Furthermore, a PPDU including an intra-BSS frame may be an intra-BSS PPDU. Furthermore, a PPDU including an inter-BSS frame may be an inter-BSS PPDU.

[0151] 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 based on whether or not at least one of the one or more BSS classification conditions is satisfied.

[0152] The BSS classification conditions may include a condition based on BSS color. BSS color may be an identifier for a BSS. Also, BSS color may be included in the preamble of a PPDU, more specifically, in the signaling field (e.g., the HE-SIG-A field, the U-SIG field, or the VHT-SIG-A field). Also, BSS color may be included in TXVECTOR, which is transmitted from the MAC layer of the sender to the PHY layer. Also, BSS color may be included in RXVECTOR, which is transmitted from the PHY layer of the receiver to the MAC layer. The parameters included in TXVECTOR and RXVECTOR may be referred to as TXVECTOR parameters and RXVECTOR parameters, respectively. Also, BSS color may be included in the TXVECTOR parameter or RXVECTOR parameter. The AP may notify the STA of the BSS color set by the AP. According to an embodiment, BSSs can be classified based on the BSS color included in the received PPDU. If the BSS color included in a PPDU received by a 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 a PPDU received by a 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. Furthermore, if the BSS color included in a PPDU received by a 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.

[0153] The BSS classification conditions may include a condition based on a MAC address. The MAC address may be included in the MAC header of the frame. The MAC address may include a receiver address (RA), a transmitter address (TA), a BSSID, a source address (SA), a destination address (DA), etc. According to one embodiment, a BSS may be classified based on a MAC address included in a received frame. If the MAC address included in the received frame is different from the BSSID of the BSS corresponding to the STA, the received frame may be classified as an inter-BSS frame. More specifically, if all of the MAC addresses included in the received frame are different from the BSSID of the BSS corresponding to the STA, the received frame may be classified as an inter-BSS frame. If the MAC address included in the received frame is the same as the BSSID of the BSS corresponding to the STA, the received frame may be classified as an intra-BSS frame. More specifically, if at least one of the MAC addresses included in the received frame is the same as the BSSID of the BSS corresponding to the STA, the received frame may be classified as an intra-BSS frame.

[0154] The corresponding BSS may include a BSS associated with the STA. The corresponding BSS may also include a BSS included in the same multiple BSSID set as the BSS associated with the STA. The corresponding BSS may also include a BSS included in the same co-hosted BSSID set as the BSS associated with the STA. For one or more BSSs included in the same multiple BSSID set or the same co-hosted BSSID set, information about the one or more BSSs may be transmitted via one frame.

[0155] The BSS classification condition may include a condition based on the value of the Partial AID field included in the VHT PPDU. The Partial AID field may be included in the preamble of the VHT PPDU. The Partial AID field may also be included in the VHT-SIG-A field included in the VHT PPDU. According to one embodiment, the Partial AID field may indicate a portion of the BSS color. For example, when the partial BSS color function is used, the Partial AID field may indicate a portion of the BSS color. Alternatively, when an AID assignment rule is used, the Partial AID field may indicate a portion of the BSS color. The AID assignment rule may be a method of assigning an AID based on the BSS color. Furthermore, when the Group ID field included in the VHT-SIG-A field of the VHT PPDU is a pre-set value (e.g., when the Group ID field is set to 63), the Partial AID field may indicate a portion of the BSS color. According to one embodiment, when the Partial AID field of a received PPDU indicates part of a BSS color, if the received Partial AID field value is different from part of the BSS color corresponding to the receiving STA, the received PPDU can be classified as an inter-BSS PPDU.

[0156] Furthermore, when the Partial AID field of a received PPDU indicates a portion of a BSS color, if the value of the received Partial AID field is identical to a portion of the BSS color corresponding to the receiving STA, the received PPDU can be classified as an intra-BSS PPDU. In this case, the portion of the BSS color may be 4 LSBs of the BSS color. According to another embodiment, the Partial AID field may indicate a portion of the BSSID. For example, if the Group ID field included in the VHT-SIG-A field of the VHT PPDU has a pre-set value (e.g., the Group ID field is set to 0), the Partial AID field may indicate a portion of the BSSID. According to one embodiment, when the Partial AID field of a received PPDU indicates a portion of a BSSID, if the value of the received Partial AID field is different from a portion of the BSSID corresponding to the receiving STA, the received PPDU can be classified as an inter-BSS PPDU. Furthermore, if the Partial AID field of a received PPDU indicates a portion of a BSSID, and the received Partial AID field value is identical to a portion of the BSSID corresponding to the receiving STA, the received PPDU can be classified as an intra-BSS PPDU. In this case, the portion of the BSSID can be the 9 MSBs of the BSSID. In addition, the Partial AID field value can be included in the TXVECTOR parameter PARTIAL_AID or the RXVECTOR parameter PARTIAL_AID. In addition, the Group ID field value can be included in the TXVECTOR parameter GROUP_ID or the RXVECTOR parameter GROUP_ID.

[0157] The BSS classification conditions may include conditions under which the AP receives a PPDU of a pre-set condition. For example, the PPDU of the pre-set condition may include a downlink PPDU. According to one 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 the signaling field of the HE PPDU. Alternatively, the signaling indicating uplink or downlink may be included in a U-SIG. The U-SIG may be included in the preamble of an EHT PPDU or a post-EHT standard PPDU.

[0158] 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 met, the PPDU cannot be classified as an intra-BSS PPDU or an inter-BSS PPDU.

[0159] In addition, when classifying BSSs, if the classification results based on multiple conditions do not match, the final result can be determined based on the pre-set conditions. For example, if the result based on the BSS color condition does not match the result based on the MAC address condition, the result based on the MAC address condition takes precedence, or the result based on the MAC address condition can be determined as the final result. Alternatively, if both the conditions for classification as an intra-BSS PPDU and the conditions for classification as an inter-BSS PPDU are met, the PPDU can be classified as an intra-BSS PPDU.

[0160] According to an embodiment of the present invention, a STA may perform an operation based on a 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. The intra-PPDU power save operation can be performed when a pre-defined condition is met. The pre-defined condition may include a condition for classifying a received PPDU as an intra-BSS PPDU. The pre-defined condition may also include a condition that the intended receiver of a received PPDU is not the STA that received the PPDU. For example, if an ID or address included in a PPDU does not correspond to the STA that received the PPDU, the intended receiver of the PPDU may not be the STA that received the PPDU. The ID may be included in the preamble of the PPDU. For example, the ID may be the STA_ID included in the preamble of the PPDU. The STA_ID may be included in an EHT MU PPDU or an EHT PPDU. The address may be the MAC address described above. Furthermore, if 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. Furthermore, if the configuration of the received PPDU is set to a format 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, the channel width, etc. Furthermore, if the STA that received the PPDU does not support the configuration of the received PPDU, a PHY-RXEND.indication(UnsupportedRate) primitive may be received. Furthermore, if the received PPDU is in a pre-configured format, the intended recipient of the PPDU may not be the STA that received the PPDU. The pre-configured 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 in 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 information included in the trigger frame may include the length of the response PPDU, the RU to be used in the response, the PHY configuration to be used in the response, the MAC configuration, etc. The intra-PPDU power saving operation may be an operation that can enter a doze state until the end of the received PPDU. As another example, if a STA determines that the intended recipient of a received PPDU or frame is not the STA, the STA may suspend reception or decoding of the PPDU or frame.

[0161] 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. Furthermore, when a STA receives a PPDU or a frame, the STA may set a NAV corresponding to the classified BSS based on the received PPDU or frame. For example, an intra-BSS NAV may be a NAV corresponding to an intra-BSS PPDU. Furthermore, a basic NAV may be a NAV corresponding to a PPDU that is not an intra-BSS PPDU. Furthermore, a basic NAV may be a NAV corresponding to an inter-BSS PPDU. Furthermore, when setting a NAV based on a received PPDU or a received frame, duration information included in the received PPDU or the received frame may be used. The duration information may include a TXOP. TXOP may refer to a value included in the TXOP field. The TXOP field may be included in the preamble of a PPDU. For example, the TXOP field may be included in the HE-SIG-A field of an HE PPDU. Alternatively, the TXOP field may be included in the U-SIG field of an EHT PPDU or a post-EHT standard PPDU. The duration information may also be included in the MAC header. For example, the duration information may be included in a Duration / ID field included in the MAC header.

[0162] The operation based on the classified BSS may include a spatial reuse operation. 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 met, 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. The pre-set condition may include a condition that the signal strength of the received PPDU or the received frame is lower than a threshold. For example, the threshold may be variable. The threshold may be a threshold for an OBSS PD-based spatial reuse operation. The threshold may be a value equal to or greater than the CCA threshold. 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. 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 frame. If a STA performs spatial reuse, the STA may be able to transmit a PPDU while a received PPDU or frame is being transmitted or received.

[0163] Referring to FIG. 13, BSS A and BSS B may exist, and BSS A and BSS B may be different BSSs. BSS A and BSS B may correspond to inter-BSSs. 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. STA1 and STA2 may belong to BSS A (or associated with the AP operating BSS A). STA3 and STA4 may belong to BSS B (or associated with the AP operating BSS B). Referring to FIG. 13, STA1 may transmit a PPDU. The PPDU transmitted by STA1 may include information about the BSS. For example, the information about the BSS may be information for classifying the BSSs described above. The PPDU transmitted by STA1 may include duration information.

[0164] STA2 receives the PPDU transmitted by STA1 and can classify the BSS for this PPDU. Since STA2 and STA1 belong to BSS A, the PPDU received by STA2 may be classified as an intra-BSS PPDU. Furthermore, 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-described embodiment, STA2 can perform intra-PPDU power saving. Referring to FIG. 13, STA2 may enter a doze state until the end of the received PPDU. Furthermore, STA2 can set its 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 its intra-BSS NAV.

[0165] STA3 receives the PPDU sent by STA1 and can classify the BSS for this PPDU. Also, since STA3 and STA1 belong to BSS B and BSS A, respectively, the PPDU received by STA3 can be classified as an inter-BSS PPDU. Also, 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 basic NAV.

[0166] STA4 receives the PPDU transmitted by STA1 and can classify the BSS for this PPDU. Furthermore, 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. Furthermore, the signal strength of the PPDU received by STA4 may be lower 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 lower than a threshold, STA4 can perform spatial reuse. Therefore, STA4 can perform channel access and backoff procedures and begin transmission. For example, STA4 may begin transmission before the PPDU transmitted by STA1 has finished.

[0167] FIG. 14 shows a wireless LAN function according to an embodiment of the present invention.

[0168] Referring to FIG. 14 , a WLAN of one standard may include the functions of a WLAN of another standard. Or, a WLAN of one standard may be a WLAN of another standard. Here, WLAN can refer to an STA. Furthermore, WLAN can refer to an MLD including an STA. For example, a WLAN standard may include the standard functions of a previous generation and include additional functions. For example, an HT STA can also be an OFDM PHY STA. An HT STA can also perform additional functions in addition to the functions of an OFDM PHY STA. For example, a VHT STA can also be an HT STA. A VHT STA can also perform additional functions in addition to the functions of an HT STA. For example, an HE STA can also be a VHT STA. An HE STA can also perform additional functions in addition to the functions of a VHT STA. An EHT STA can also be an HE STA. An EHT STA can also perform additional functions in addition to the functions of an HE STA. There may also be standards subsequent to the EHT standard. In the present invention, the standard subsequent to the EHT standard can be called the NEXT standard, and the STA that complies with the NEXT standard can be called the NEXT STA. The NEXT STA can also be an EHT STA. In addition, the NEXT STA can perform additional functions in addition to the functions of the EHT STA.

[0169] Figure 14 is a diagram showing the relationship between STAs of each standard. Referring to Figure 14, an EHT STA can be an HE STA, a VHT STA, an HT STA, or an OFDM PHY STA. Also, a NEXT STA can be an EHT STA, an HE STA, a VHT STA, an HT STA, or an OFDM PHY STA.

[0170] FIG. 15 illustrates an uplink (UL) multi-user (MU) operation according to one embodiment of the present invention.

[0171] Referring to FIG. 15, an AP can instruct at least one STA to transmit a PPDU through a specific frame (e.g., a triggering frame), and at least one STA can simultaneously transmit PPDUs of the same or individual formats based on the specific frame transmitted from the AP.

[0172] Specifically, as shown in FIG. 15, a frame soliciting or triggering a multi-user (MU) transmission may be transmitted, and one or more STAs may transmit or respond to such a frame based on such a frame. In this case, when one or more STAs transmit a response to the frame, the one or more STAs may simultaneously respond immediately based on the frame, and the response to the frame may begin transmission SIFS after the end of the PPDU containing the frame. For example, if the frame solicits an immediate response, one or more STAs may immediately transmit a response to the frame. A frame soliciting or triggering one or more STAs to transmit may be a trigger frame or a frame including information in its MAC header that solicits or triggers uplink transmission to one or more STAs. In this case, the frame may include information (e.g., a TRS control subfield) in its MAC header that triggers or instructs only one STA to transmit uplink.

[0173] For example, the information indicating or triggering an uplink transmission included in the MAC header may be a triggered response scheduling (TRS) or TRS control subfield included in an HT control field, a control subfield, or an A-control subfield.

[0174] A frame for instructing or triggering uplink transmission may be transmitted by an AP. If the frame for instructing or triggering uplink transmission is a trigger frame, a response thereto may be transmitted in a trigger-based PPDU (TB PPDU) format. In this case, the TB PPDDU may include the above-mentioned HE TB PPDU and EHT TB PPDU, as well as a NEXT TB PPDU that may be defined in the next standard.

[0175] The HE TB PPDU may consist of a preamble, data, and a packet extension (PE), and the preamble may include L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, HE-STF, and HE-LTF in that order.

[0176] The EHT TB PPDU and NEXT TB PPDU may also be composed of a preamble, data, and PE, and the preambles of the EHT TB PPDU and NEXT TB PPDU may include L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, (EHT- / NEXT-)STF, and (EHT- / NEXT-)LTF in that order.

[0177] A frame that instructs or triggers one or more STAs to transmit a PPDU may include information necessary for one or more STAs to transmit a TB PPDU. For example, if a frame includes a type subfield of "01" (B3 B2) and a subtype subfield of "0010" (B7 B6 B5 B4), the frame including such type and subtype subfields may be a trigger frame, which is a control frame.

[0178] If multiple STAs are instructed or triggered to respond with a TB PPDU, and the formats of the PPDUs to which the multiple STAs respond are different from each other, a problem may occur in that the AP that instructed or triggered the response has difficulty receiving the response PPDUs transmitted from the multiple STAs. Alternatively, if the information contained in the preambles of the PPDUs to which the multiple STAs respond differs depending on the format, a problem may occur in that the AP that instructed or triggered the response has difficulty receiving the response PPDUs transmitted from the multiple STAs.

[0179] Therefore, to solve this problem, when multiple STAs respond to a frame from an AP, the format of the responding PPDU and / or the type of information included in the preamble of the PPDU may be set to be the same. For example, when multiple STAs transmit HE TB PPDUs in response to a frame from an AP, the AP may transmit information so that the information included in the L-STF, L-LTF, L-SIG, RL-SIG, and HE-SIG-A is the same, or a convention may be defined for the information included in the HE TB PPDU, so that the AP can successfully receive the preambles transmitted by the multiple STAs. However, if the HE TB PPDU, EHT TB PPDU, and NEXT TB PPDU are simultaneously transmitted in overlapping subbands, the TB PPDU formats may be different from each other, which may make it difficult for the AP to receive them.

[0180] According to an embodiment of the present invention, an HE STA can transmit an HE TB PPDU. An EHT STA can transmit an EHT TB PPDU or an HE TB PPDU. A NEXT STA can transmit a NEXT TB PPDU, an EHT TB PPDU, or an HE TB PPDU. This is because, as described in FIG. 10, a STA of a certain standard may include the functionality of a previous standard.

[0181] As shown in Figure 15, when an AP transmits a frame to schedule the transmission of a TB PPDU to an HE STA and an EHT STA, and uses the frame to instruct or trigger the transmission of a TB PPDU, there may be no precise instruction or protocol for the TB PPDU format. In this case, the HE STA transmits an HE TB PPDU in response to the frame, and the EHT STA may respond with an EHT TB PPDU or an HE TB PPDU. In this case, the AP may have difficulty receiving the TB PPDUs transmitted by these STAs. This may result in the AP being unable to successfully receive TB PPDUs from multiple STAs, resulting in the medium being occupied and reducing transmission opportunities for other STAs.

[0182] Hereinafter, in the present invention, instructing an STA can mean instructing a response from the STA, and the terms "trigger" and "instruct" may be used interchangeably.

[0183] Furthermore, the HE trigger frame, EHT trigger frame, and NEXT trigger frame may be trigger frames defined in the HE, EHT, and NEXT standards, respectively. Furthermore, in the present invention, the HE TRS, EHT TRS, and NEXT TRS may be TRSs defined in the HE, EHT, and NEXT standards, respectively.

[0184] FIG. 16 shows a trigger frame format according to an embodiment of the present invention.

[0185] Figure 16(a) shows the trigger frame format, and Figure 16(b) and (c) show the common info(information) field and the user info field, respectively, which are fields included in the trigger frame.

[0186] 16(a), as a trigger MAC header, the frame includes a Frame Control field, a Duration field, an Address field, and may include a Common Information field and a User Information List field. The Address field may include a Resource Allocation (RA) field and a Transmitter Address (TA) field.

[0187] The common information field may include information that is common to all STAs designated by the trigger frame. Figure 12(b) shows an example of the common information field.

[0188] The user information list field may contain zero or more user information fields, and the user information list field of a trigger frame other than a specific type of trigger frame may contain one or more user information fields. (c) of Figure 16 shows an example of a user information field.

[0189] The trigger frame may additionally include a padding field and a frame check sequence (FCS) field. The padding field may be used to increase the length of the frame to allow time for a STA receiving the trigger frame to prepare a response to the trigger frame, and may be optionally included in the trigger frame.

[0190] Referring to (b) of Figure 16, the common information field may include a trigger type subfield. The trigger type subfield may be used to identify a trigger frame variant. Alternatively, the type of trigger frame may be indicated based on the value of the trigger frame subfield. Furthermore, the information and length included in the trigger dependent common information subfield and the trigger dependent user information subfield shown in Figure 12 may be determined based on the trigger type subfield. For example, the trigger type subfield may be indicated by bits B0 to B3 of the common information field.

[0191] The common information field may include an Uplink (UL) length subfield. The UL length subfield may include information about the length of the TB PPDU, which is a response to the trigger frame, or may include information about the length of a frame responding to the trigger frame. The UL length subfield may also indicate the value included in the length subfield of the L-SIG of the TB PPDU responding to the trigger frame. Therefore, a STA that receives a trigger frame and responds with a TB PPDU can set the value of the length subfield included in the L-SIG of the TB PPDU based on the value of the UL length subfield included in the received trigger frame. Specifically, a STA that responds with a TB PPDU can set the length subfield included in the L-SIG of the TB PPDU to the value of the UL length subfield included in the received trigger frame. For example, a STA can transmit a TB PPDU by setting the length subfield included in the L-SIG of the TB PPDU based on the value of bits B4 to B15 of the common information field, which indicate the UL length subfield.

[0192] The common information field may further include an uplink bandwidth subfield (UL Bandwidth (BW) subfield). The UL BW subfield may indicate a BW value included in a signaling field (e.g., HE-SIG-A or U-SIG) of a TB PPDU responding to the trigger frame, and may indicate the maximum BW of a TB PPDU transmitted in response to the trigger frame. Therefore, the STA can set the BW value included in the signaling field of the TB PPDU based on the value of the UL BW subfield included in the trigger frame.

[0193] In addition, the common information field may further include information included in the signaling field of the TB PPDU, which is a response to the trigger frame. Therefore, after receiving the trigger frame, the STA can set the information included in the TB PPDU based on the information included in the trigger frame.

[0194] Referring to (c) of FIG. 16, the user information field may include an AID12 subfield. The AID12 subfield may be used to indicate the intended recipient of the user information field including the AID12 subfield or the function of the user information field. Therefore, the AID12 subfield may also serve 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 pre-configured value, the user information field may indicate a Random Access Resource Unit (RA-RU). That is, the pre-configured value of the AID12 subfield may indicate that the user information field indicates an RA-RU. Specifically, if the value of the AID12 subfield is '0', the user information field may indicate an RA-RU for associated STAs. For example, if the value of the AID12 subfield is "0", the user information field can indicate an RA-RU for associated STAs, and if the value of the AID12 subfield is "2045", the user information field can indicate an RA-RU for unassociated STAs. STAs corresponding to the STA ID (e.g., AID (association ID)) indicated by the value of the AID12 subfield may be instructed to respond by a user information field including the AID12 subfield or a trigger frame including the AID subfield. For example, the AID12 subfield can indicate the AID or 12 LSBs of the AID. STAs corresponding to the value indicated by the AID12 subfield can transmit a TB PPDU in response to the received trigger frame. In this case, the value of the AID12 subfield may be in the range of "1" to "2007" (inclusive), and if the AID12 subfield is a previously set value (e.g., "2046"), the RU corresponding to the previously set value of the AID12 subfield may not be assigned to any STA.Also, if the AID subfield is already set to a value (for example, "4095"), the already set value may indicate that padding of the trigger frame begins.

[0195] Information in the user information field including the AID12 subfield may be information corresponding to the STA indicated by the AID12 subfield. For example, the Resource Unit (RU) Allocation subfield may indicate the size and location of the RU. In this case, the value of the RU Allocation subfield in the user information field including the AID12 subfield may be information corresponding to the STA indicated by the AID12 subfield. That is, the RU indicated by the RU Allocation subfield in the AID12 subfield may be the RU allocated to the STA indicated by the AID12 subfield.

[0196] The user information field may also indicate the coding method (UL FEC coding type), modulation method (UL HE-MCS, UL DCM), and power (UL Target RSSI) for generating the TB PPDU to be transmitted in response to the trigger frame.

[0197] FIG. 17 illustrates a method for indicating a triggered-based (TB) PPDU format according to one embodiment of the present invention.

[0198] Referring to FIG. 17, one STA can selectively transmit PPDUs of different formats based on instructions from a triggering frame instructing the transmission of the PPDU.

[0199] Specifically, an EHT STA can selectively transmit not only a legacy PPDU (e.g., an HE TB PPDU) but also an EHT TB PPDU, and a NEXT STA can selectively transmit an HE TB PPDU, an EHT TB PPDU, and / or a NEXT TB PPDU. In this case, STAs to which multiple standards are applied can be individually scheduled using one frame or one PPDU. This method can be advantageous because STAs to which multiple standards are applied share common resources in a WLAN. For example, an HE STA (an HE STA other than an EHT STA) can respond with an HE TB PPDU using one frame. That is, a non-AP STA can transmit a triggering frame to instruct EHT STAs as well as HE STAs to transmit an HE TB PPDU.

[0200] In addition, information for selecting the TB PPDU format may be included in a triggering frame, such as a trigger frame, a TRS, a PPDU including the trigger frame, or a PPDU including a TRS control subfield. That is, the AP STA includes information for selecting the TB PPDU format in a triggering frame and transmits it to at least one non-AP STA, and the non-AP STA can select the format of a PPDU to respond to based on the information included in the received triggering frame. The at least one non-AP STA can then transmit a PPDU to the AP based on the selected format.

[0201] Information on the format of the PPDU (TB PPDU format) which is a response to such a triggering frame may exist at the MAC level, and a trigger frame, which is one of the triggering frames, may be classified into an HE trigger frame, an EHT trigger frame, and a NEXT trigger frame, and responses to each trigger frame may be classified into an HE TB PPDU, an EHT TB PPDU, and a NEXT TB PPDU.

[0202] In addition, classifying trigger frames into HE trigger frames, EHT trigger frames, and NEXT trigger frames may be equivalent to classifying the TB PPDU formats, which are responses to trigger frames, into HE TB PPDU, EHT TB PPDU, and NEXT TB PPDU, respectively.

[0203] Whether the format of a trigger frame for distinguishing the format of a TB PPDU is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame may be identified based on a Frame Control field included in a MAC header. Specifically, the format of the trigger frame may be distinguished based on a Type subfield, a Subtype subfield, and / or a Control Frame Extension subfield. Furthermore, if the values ​​of the Type subfield, the Subtype subfield, and / or the Control Frame Extension subfield are pre-set values, the trigger frame may be identified as an HE trigger frame, and if the values ​​are other pre-set values, the trigger frame may be identified as an EHT trigger frame. Furthermore, if the values ​​of the Type subfield, the Subtype subfield, and / or the Control Frame Extension subfield are other pre-set values, the trigger frame may be identified as a NEXT trigger frame.

[0204] For example, if the Type subfield is 01 (B3 B2) and the Subtype subfield is 0010 (B7 B6 B5 B4), the format of the frame including the Type subfield and the Subtype subfield may be an HE trigger frame. In this case, it may be necessary to further use entries in the Type subfield (2 bits), the Subtype subfield (4 bits), and / or the Control Frame Extension subfield (4 bits), which are assigned limited numbers of bits, in the EHT standard and the NEXT standard.

[0205] Alternatively, whether the format of the trigger frame is an HE trigger frame or an EHT trigger frame may be identified based on the common information field included in the trigger frame. That is, the format of the PPDU transmitted in response to the trigger frame may be determined based on the value of a specific subfield (first subfield) included in the common information field. For example, a non-AP STA may select an HE TB PPDU or an EHT TB PPDU based on the value of the common information field and transmit it in the assigned RU. In this case, in addition to the common information field, a specific subfield (second subfield) of the user information field may also be used to identify the format of the PPDU.

[0206] That is, a variant for determining the format of a PPDU that is a response to the trigger frame may be determined based on the common information field of the trigger frame, and the format of the PPDU may be determined based on the determined variant. For example, if the variant for determining the PPDU format is determined to be the HE variant based on the common information field, the non-AP STA may respond with an HE TB PPDU, and if the variant for determining the PPDU format is determined to be the EHT variant based on the common information field, the non-AP STA may respond with an EHT TB PPDU.

[0207] In this case, the variant for determining the format of the PPDU may further use a user information field in addition to the common information field.

[0208] For example, a trigger frame may be classified as an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame based on the trigger type subfield. For example, if the trigger type subfield value is a previously set value, the trigger frame may be an HE trigger frame. Also, if the trigger type subfield value is a previously set value, the trigger frame may be an EHT trigger frame. If the trigger type subfield value is a previously set value, the trigger frame may be a NEXT trigger frame.

[0209] For example, if the trigger type subfield value is 0 to 7, it is an HE trigger frame, and if it is not 0 to 7, it may be an EHT trigger frame or a NEXT trigger frame. The trigger type subfield indicates various trigger frame types, but in this case, there is a disadvantage that a limited trigger type subfield space must be used.

[0210] According to still another embodiment, a trigger frame may be distinguished as an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame based on a UL length subfield of the trigger frame. For example, a trigger frame may be distinguished as an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame based on a value obtained by modulating the UL length subfield value (remainder). That is, the value of the UL length subfield may be used to determine whether the format of a PPDU transmitted in response to a trigger frame is an HE PPDU or an EHT PPDU.

[0211] More specifically, the trigger frame can be distinguished as an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame based on the value obtained by modulating the UL length subfield value modulo 3 (the remainder when the UL length subfield is divided by 3). For example, if the result of modulating the UL length subfield value modulo 3 is not 0, the trigger frame may be an HE trigger frame. Alternatively, if the result of modulating the UL length subfield value modulo 3 is 1, the trigger frame may be an HE trigger frame. Alternatively, if the result of modulating the UL length subfield value modulo 3 is 0, the trigger frame may not be an HE trigger frame. Alternatively, if the result of modulating the UL length subfield value modulo 3 is 0, the trigger frame may be an EHT trigger frame or a NEXT trigger frame.

[0212] That is, if the value modulo 3 of the UL length subfield of the trigger frame is not 0, the response to the trigger frame may be transmitted in an HE TB PPDU, and if the value modulo 3 of the UL length subfield is 1, the response to the trigger frame may be transmitted in an HE TB PPDU.

[0213] Also, when the value modulo 3 of the UL length subfield of the trigger frame is 0, the format of the PPDU transmitted in response to the trigger frame may be EHT TB PPDU.

[0214] Furthermore, an additional trigger frame classification method can be used in addition to this method to classify the HE trigger frame, EHT trigger frame, and NEXT trigger frame. For example, the classification method described in FIG. 16 can be used in addition to this method to classify the HE trigger frame, EHT trigger frame, and NEXT trigger frame.

[0215] According to one embodiment, the format of the trigger frame may be determined as an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame based on a User Info field of the trigger frame.

[0216] That is, similar to the above-described common information field, whether the format of the trigger frame is an HE trigger frame or an EHT trigger frame can be identified based on the user information field included in the trigger frame. That is, the format of the PPDU transmitted in response to the trigger frame may be determined based on the value of a specific subfield (second subfield) included in the user information field. For example, depending on the value of the user information field, a non-AP STA may select an HE TB PPDU or an EHT TB PPDU and transmit it in the assigned RU. In this case, in addition to the user information field, a specific subfield (first subfield) of the common information field may also be used to identify the format of the PPDU.

[0217] That is, a variant for determining the format of a PPDU that is a response to the trigger frame may be determined based on the user information field of the trigger frame, and the format of the PPDU may be determined based on the determined variant. For example, if the variant for determining the PPDU format is determined to be the HE variant based on the user information field, the non-AP STA may respond with an HE TB PPDU, and if the variant for determining the PPDU format is determined to be the EHT variant based on the user information field, the non-AP STA may respond with an EHT TB PPDU.

[0218] In this case, in addition to the user information field, a common information field may also be used as a variant for determining the format of the PPDU.

[0219] For example, a frame may be distinguished as an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame based on the AID12 subfield. According to one embodiment, a frame may be distinguished as an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame based on whether or not it includes an AID12 subfield with a preset value. In this case, a question may arise as to whether a STA indicated by a certain user information field should continue to check the AID12 subfield present after the user information field to determine the trigger frame format. To solve this problem, a user information field including an AID12 subfield indicating which trigger frame it is may be located at the beginning of the user information list. In addition, to prevent HE STAs that cannot understand this signaling method from malfunctioning, a user information field including an AID12 subfield indicating which trigger frame it is may be located after the user information field corresponding to the HE STA.

[0220] In addition, since information on subfields other than the AID12 subfield included in the user information field may not be necessary for the TB PPDU response, subfields of the user information field including the AID12 subfield indicating which trigger frame it is may be omitted. That is, the length of the user information field may vary depending on the AID12 subfield. Referring to FIG. 15, the AID12 subfield may serve to indicate the format of the TB PPDU to be responded to. For example, if the AID12 subfield is a pre-set value, the response to the trigger frame including the AID12 subfield set to the pre-set value may be an EHT TB PPDU. For example, if the AID12 subfield value is 2047, the response to the trigger frame including the AID12 subfield may be an EHT TB PPDU. Furthermore, if the AID12 subfield is a pre-set value, the response to the trigger frame including the AID12 subfield set to the pre-set value may be a NEXT TB PPDU. For example, if the AID12 subfield value is 2048, the response to a trigger frame containing the AID12 subfield may be a NEXT TB PPDU.

[0221] According to another embodiment, when responding based on a user information field located at a pre-set position from the AID12 subfield of a pre-set value, the response can be made in a TB PPDU format corresponding to the pre-set value. For example, when responding based on a user information field located after the AID12 subfield of a pre-set value, the response can be made in a TB PPDU format corresponding to the pre-set value. If there are multiple values ​​indicating a TB PPDU format, when responding based on a user information field located after both the pre-set value 1 and the pre-set value 2, the response can be made in a TB PPDU format according to the pre-set priority between the TB PPDU format corresponding to the pre-set value 1 and the TB PPDU format corresponding to the pre-set value 2. Referring to FIG. 15, when responding based on a user information field located after the AID12 subfield set to 2047, the response can be made in an EHT TB PPDU. Also, when responding based on a user information field located after the AID12 subfield set to 2048, the response can be made in a NEXT TB PPDU. Also, when responding based on a user information field that exists after both the AID12 subfield set to 2047 and the AID12 subfield set to 2048, it can respond with a NEXT TB PPDU. Also, when responding based on a user information field that exists before both the AID12 subfield set to 2047 and the AID12 subfield set to 2048, it can respond with a HE TB PPDU.

[0222] In this embodiment, an example is given in which the AID12 subfield indicates the type of trigger frame, but the present invention is not limited to this, and it is also possible to indicate the type of trigger frame in other subfields of the user information field.

[0223] According to an embodiment, the trigger frame may be distinguished as an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame based on a padding field of the trigger frame. For example, whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame can be determined based on whether the padding field includes a pre-set value indicating whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame.

[0224] According to an embodiment of the present invention, it is possible to distinguish between an HE trigger frame, an EHT trigger frame, and a NEXT trigger frame by combining a plurality of trigger frame distinction methods described in the present invention. In addition, the contents described in the present invention regarding trigger frames are not limited to the above and can also be applied to TRS.

[0225] In yet another embodiment of the present invention, the AP may not be able to use a triggering frame to instruct transmission of both the EHT PPDU and the HE PPDU, i.e., the EHT AP cannot transmit a trigger frame instructing both the HE TB PPDU and the EHT TB PPDU, and can only instruct one PPDU format.

[0226] FIG. 18 illustrates UL MU operation according to yet another embodiment of the present invention.

[0227] As described above, in addition to the trigger frame, the transmission of a TB PPDU can also be indicated by a TRS. Also, the TRS may be included in the HT control field as described above. For example, when the HT control field includes an A-control field, it can include a TRS. The TRS can be conveyed by a TRS control subfield. The A-control field may be in the form of a series of control list fields. Also, the control list field may include a TRS.

[0228] In addition, a receiver of a frame including a TRS (indented receiver) can respond to the TRS. For example, a STA corresponding to an RA included in a frame including a TRS can respond to the TRS. The TRS may include information on the length of a PPDU or frame responding to the TRS (UL Data Symbols), the location and size of an RU used when responding to the TRS (RU Allocation), information on power when responding to the TRS (AP Tx Power, UL Target RSSI), information on a modulation method when responding to the TRS (UL HE-MCS), etc.

[0229] The embodiment of Fig. 18 may be a method for solving the problems described in Fig. 14 and Fig. 15. Also, as described above, the above-mentioned embodiment regarding the trigger frame can also be applied to the TRS. Also, the above-mentioned content can be omitted.

[0230] According to one embodiment of the present invention, in addition to the TRS defined in the HE standard (HE TRS), TRS defined in the EHT standard or the NEXT standard (EHT TRS and NEXT TRS, respectively) may also exist. Therefore, depending on whether the indicated TRS is the HE TRS, EHT TRS, or NEXT TRS, the TB PPDU responding to the TRS may be the HE TB PPDU, EHT TB PPDU, or NEXT TB PPDU, respectively. For example, the TRS defined by which standard can be determined by the Control ID subfield of the A-Control subfield. As an additional example, the TRS can be divided into two types: the HE TRS and a TRS other than the HE TRS.

[0231] Alternatively, for example, the TRS defined by which standard is used may be determined depending on whether the HT control field is an HE variant, an EHT variant, or a NEXT variant. Also, whether it is an HE variant, an EHT variant, or a NEXT variant may be determined depending on the value of the already set bits in the HT control field. For example, if B0 and B1 in the HT control field are 1, 1, it may be an HE variant. Also, whether it is an HE variant, an EHT variant, or a NEXT variant can be determined using B0 and B1 in the HT control field and an additional bit (e.g., B31).

[0232] According to one embodiment of the present invention, it is possible to determine the TB PPDU format in response to the TRS based on the PPDU format including the TRS. That is, when a PPDU instructing PPDU transmission includes a TRS control subfield, the PPDU format may be determined based on the format of the PPDU including the TRS control subfield. For example, when the format of the PPDU including the TRS control subfield is HE PPDU, the format of the indicated PPDU may be HE PPDU. However, when the format of the PPDU including the TRS control subfield is EHT PPDU, the format of the indicated PPDU may be EHT PPDU.

[0233] 18, when a TRS is transmitted in an HE PPDU, a TB PPDU responding to the TRS may be an HE TB PPDU. When a TRS is transmitted in an EHT PPDU, a TB PPDU responding to the TRS may be an EHT TB PPDU. When a TRS is transmitted in a NEXT PPDU, a TB PPDU responding to the TRS may be a NEXT TB PPDU.

[0234] According to an embodiment of the present invention, the subfields included in the TRS may be interpreted differently depending on the PPDU format in which the TRS is included. For example, when the TRS is included in an HE PPDU, the UL HE-MCS subfield (or a subfield related to MCS) included in the TRS may indicate a value corresponding to the HE MCS table. When the TRS is included in an EHT PPDU, the UL HE-MCS subfield (or a subfield related to MCS) included in the TRS may indicate a value corresponding to the EHT MCS table. When the TRS is included in a NEXT PPDU, the UL HE-MCS subfield (or a subfield related to MCS) included in the TRS may indicate a value corresponding to the NEXT MCS table. In addition, the RU Allocation subfield may also be interpreted differently depending on the PPDU format in which the TRS is included.

[0235] FIG. 19 illustrates an example of a packet extension (PE) field for providing processing time according to an embodiment of the present invention.

[0236] Referring to FIG. 19, when transmitting a PPDU, a specific field that does not need to be decoded may be included at the end of the PPDU to provide additional processing time for the receiving device to process the received PPDU.

[0237] Specifically, a receiving device that receives a PPDU can decode the PPDU, interpret the PPDU, and transmit a response to the transmitting device. However, if the time required to process the PPDU increases due to a decrease in the performance of the receiving device, the receiving device may not be able to transmit a response to the PPDU within the time required to transmit the response. Therefore, to ensure time for such processing, the PPDU may include a field that does not require decoding, which may be called a PE field.

[0238] Since the PE field does not require separate decoding, the receiving device can secure time to decode and process the PPDU during the duration of the PE field, and can transmit a response to the PPDU to the transmitting device within a predetermined time. That is, the PE field is located at the end of the PPDU, and can provide additional processing time to the receiving device, i.e., the terminal.

[0239] Therefore, the PE field may be located at the end of the PPDU to provide additional processing time, or may be located next to the data field. For example, the PPDU may be included in the order of preamble, data field, and PE field. The preamble and data field may be as described in the above embodiments. For an HE PPDU, the preamble may include L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, HE-SIG-B, HE-STF, and HE-LTF. For an EHT PPDU, the preamble may include L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-SIG, EHT-STF, and EHT-LTF. A PPDU including a PE field may be an HE PPDU, an EHT PPDU, or a PPDU in a standard defined after the EHT standard.

[0240] If the PE field is not included in the PPDU, a receiving device (e.g., an STA) with low performance may have difficulty responding within a preset time from the end of the received PPDU due to the time required to process the received PPDU. The preset time may be an IFS (interframe space) or a SIFS (short interframe space) from the end of the received PPDU. Therefore, by placing the PE field, which does not need to be decoded, at the end of the received PPDU, time for processing the received PPDU can be secured. In other words, by placing a field that does not need to be decoded at the end of the PPDU, the PPDU can be processed sufficiently quickly. Therefore, it is possible to process a PPDU including a PE field and transmit an immediate response to the PPDU within a set time. In this case, the immediate response may be transmitted SIFS from the end of the PPDU including the PE field.

[0241] Also, the power at which the PE field is transmitted may be based on the power at which the data field is transmitted, for example, the power at which the PE field is transmitted may be the same as the average power at which the data field is transmitted.

[0242] The PE field may be transmitted with any content, and the location and size of the PE field in the frequency domain may be the same as the data field or the resource unit (RU) in which the data field is transmitted.

[0243] According to one embodiment of the present invention, the duration of the PE field may be 0 or a multiple of 4 us. For example, the duration of the PE field may be one of 0, 4, 8, 12, 16, and 20 us. In this case, the maximum value of the duration of the PE field may vary depending on the format of the PPDU in which the PE field is included. For example, in the case of an HE PPDU, the duration of the PE field may be one of 0, 4, 8, 12, and 16 us, and in the case of an EHT PPDU, the duration may be one of 0, 4, 8, 12, 16, and 20 us. A PE field of 0 us corresponds to no PE field being included.

[0244] According to one embodiment, the PE field of the pre-set duration may be used only for the pre-set setting. For example, the pre-set duration may be 20 us or more. The pre-set duration may be based on the MCS (modulation and coding scheme) or modulation method. That is, the PE field of the pre-set duration may be set and included in the PPDU according to the pre-set MCS index, MCS, or modulation method.

[0245] Alternatively, a PE field of a previously set MCS index, a previously set modulation, or an MCS index, modulation, or MCS equal to or greater than a previously set MCS may be included in the PPDU. For example, the previously set MCS index, the previously set modulation, or the previously set MCS may be based on 4096-QAM.

[0246] In addition to the MCS or modulation scheme, the preset value for the duration of the PE field may also be based on the number of spatial streams, for example, if more than eight spatial streams are used, the preset value for the duration of the PE field may be used.

[0247] The preset value may also be based on the channel width, bandwidth, or size of the RU to be transmitted. For example, if the channel width, bandwidth, or size of the RU is set to a preset value, the duration of the PE field may be determined to be a specific preset value.

[0248] According to one embodiment, the channel width or bandwidth may be a value corresponding to the PPDU to be transmitted. Alternatively, the channel width or bandwidth may be a value corresponding to the PPDUs simultaneously transmitted by multiple STAs or the entire PPDU. For example, when the channel width or bandwidth is 320 MHz, a specific value that has already been set may be allowed to be used as the duration value of the PE field of the PPDU. For example, a duration of 20 us may be allowed to be used only when the channel width or bandwidth is 320 MHz.

[0249] According to another embodiment, the channel width or bandwidth allowed for use of a specific value may be greater than 160 MHz, and the RU size may be greater than 2×996. Also, the RU size may be relative to the entire RU used for transmission, i.e., when multiple RUs are used, it may be relative to the sum of the sizes of multiple RUs.

[0250] That is, a specific value previously set for the duration of the PE field may be used or set only under specific conditions. For example, the duration of the PE field may be set to one of 0 us, 4 us, 8 us, 12 us, 16 us, or 20 us as described above, and the specific value may be used or set in a PPDU under the following conditions:

[0251] - PPDU modulated using 4096-QAM modulation

[0252] - PPDUs transmitted using 8 or more spatial streams (in at least one RU / MRU)

[0253] - 320MHz PPDU if the size of at least one allocated RU or MRU is 2 x 996 or more.

[0254] - EHT TB PPDU based on trigger frame (i.e., the format of the PPDU indicated by the trigger frame);

[0255] For example, the duration of the PE field may be set differently depending on the format of the PPDU indicated by the frame that triggers the transmission of the PPDU. Specifically, if the PPDU indicated by the frame is an HE TB PPDU, the duration of the PE field of the HE TB PPDU may be set to one of 0 us, 4 us, 8 us, 12 us, or 16 us. However, if the PPDU indicated by the frame is an EHT TB PPDU, the duration of the PE field of the HE TB PPDU may be set to one of 0 us, 4 us, 8 us, 12 us, 16 us, or 20 us. In other words, the value (e.g., maximum value) that can be set as the duration of the PE field may differ depending on the format of the PPDU indicated by the frame.

[0256] For example, as mentioned above, 20 us may only be acceptable under certain conditions.

[0257] For example, in the above description, the specific value already set may be 20 us, that is, a PE field having a duration of 20 us may be allowed only under the above-mentioned specific conditions or in specific cases.

[0258] FIG. 20 illustrates an example of a High Efficiency (HE) operation element and a default PE duration subfield according to an embodiment of the present invention.

[0259] Referring to FIG. 20, an AP STA (or AP) can indicate the duration value of the PE field in an operation element.

[0260] Specifically, information related to the duration of the PE field of the PPDU may be included in an action element and transmitted. The information related to the duration of the PE field may be the duration of the PE field included in the PPDU. For example, the AP may set the value of the control ID to a value indicating TRS to trigger transmission of a PPDU, and the non-AP STA may transmit the PPDU in response to the TRS PPDU. In this case, the PPDU may include a PE field for providing the above-mentioned additional processing time, and the information related to the duration of the PE field may be transmitted to the non-AP STA in a specific field (e.g., a default PE duration field) of the action element.

[0261] In this case, the duration of the PE field or the already set information related to the duration of the PE field may be called a default PE duration, and the default PE duration may be indicated by a default PE duration subfield.

[0262] The value of the Default PE Duration subfield and / or the PE field may be set by the TXVECTOR parameter DEFAULT_PE_DURATION, which is a transmission parameter. In the present invention, TRS may be used interchangeably with TRS Control.

[0263] The operation element may include information related to the operation of the BSS and may be an HE operation element or an EHT operation element depending on the format. Such operation elements may be included in and transmitted in a beacon frame, a probe request frame, a probe response frame, an association request frame, an association response frame, a reassociation request frame, and a reassociation request frame.

[0264] The default PE duration subfield included in the action element may indicate the duration of the PE field in a fixed unit (or a preset unit). In this case, the fixed unit or the preset unit may be 4 us, and if the value of the default PE duration subfield is N, the duration of the PE field indicated by the default PE duration subfield may be N*4 us. For example, if the value of the default PE duration subfield is '4', the duration of the PE field indicated by the default PE duration subfield may be 16 us.

[0265] FIG. 20(a) is a diagram showing an example of an HE operation element. Referring to FIG. 20(a), the HE operation element may include an HE operation parameters field. FIG. 20(b) is a diagram showing an example of an HE operation parameters field. Referring to FIG. 20(b), the HE operation parameters field may include a default PE duration subfield. In this case, the default PE duration subfield may be 3 bits, and values ​​5 to 7 may be reserved. That is, since values ​​5 to 7 of the default PE duration subfield are reserved, only values ​​0 to 4 may be valid. Therefore, the duration that can be specified by the default PE duration subfield may be 0, 4, 8, 12, or 16 us. If the reserved value 5 is used, the default PE duration subfield may specify up to 20 us.

[0266] FIG. 21 shows an example of a method for setting the duration of a PE field according to an embodiment of the present invention.

[0267] Referring to FIG. 21, when a non-AP STA transmits a PPDU in response to a TRS from an AP, the non-AP STA can set the duration of the PE field of the PPDU to the default PE duration obtained from the AP.

[0268] Specifically, a terminal that receives a frame for triggering PPDU transmission (e.g., a frame including a control ID subfield with a value indicating TRS or a trigger frame instructing PPDU transmission) can transmit a PPDU by including a PE field for providing additional processing time. As described above, the PE field may be set in a fixed time unit or a pre-set time unit (e.g., 0 us, 4 us, 8 us, 12 us, 16 us, or 20 us). In this case, as described above, 20 us may be allowed to be used only in certain cases.

[0269] The duration of the PE field may be set to a value indicated by the default PE duration indicated by the default PE duration field transmitted from the AP, and in this case, the default PE duration may be the same as that described above in Fig. 20, and the same content as that described in Fig. 20 will be omitted. The default PE duration field may be indicated by being included in and transmitted as an action element, as described in Fig. 20.

[0270] That is, when a non-AP STA responds to a TRS from an AP, the duration for the PE field of the PPDU can be determined based on the default PE duration transmitted and indicated from the AP. In this case, the PPDU may be a trigger frame-based PPDU such as an HE TB PPDU, an EHT TB PPDU, or a later version TB PPDU, and the AP may be an AP associated with the non-AP STA.

[0271] As shown in FIG. 21, a STA can receive a trigger frame or a frame including a TRS control field to trigger or instruct the transmission of a PPDU, and can transmit a TB PPDU in response thereto.

[0272] As described above in Figures 19 and 20, the TB PPDU may include a PE field to provide additional processing time, and the duration of the PE field may be set in fixed time units. If a default PE duration is instructed to a STA by the AP using the Default PE Duration subfield, the STA may set the duration of the PE field to the instructed default PE duration. For example, the default PE duration may be a value included in an operation element (e.g., an HE operation element or an EHT operation element) transmitted from the AP. The STA (AP or AP STA) that transmitted the default PE duration and the STA (AP or AP STA) that transmitted the TRS control field may be the same STA.

[0273] If a STA receives a trigger frame from an AP and transmits a TB PPDU in response to the trigger frame, the TB PPDU may include a PE field, and the duration of the PE field is T PE may be calculated by the following Equation 5:

[0274]

number

[0275] That is, in Equation 5,

number

[0276] m is a value that varies depending on the format of the PPDU, for example, the value of m for a TB PPDU may be 2.

[0277] T PREAMBLE means the length of the preamble of the transmitted TB PPDU. When the HE TB PPDU is transmitted, T PREAMBLE may be the sum of the lengths of L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, HE-STF and HE-LTF. When an EHT PPDU is transmitted, T PREAMBLE may be the length of the EHT preamble, i.e., when the EHT TB PPDU is transmitted, T PREAMBLE may be the sum of the lengths of L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-STF, and EHT-LTF.

[0278] N SYM may represent the number of data OFDM symbols included in the transmitted PPDU. For example, N SYM may be determined by Equation 7 below.

[0279]

number

[0280] In Equation 7, b PE_Disambiguity may be the TXVECTOR parameter TB_PE_DISAMBIGUITY value, or PE_disambiguitymay be the value of the PE Disambiguity subfield included in the trigger frame. Also, the TXVECTOR parameter TB_PE_DISAMBIGUITY may be the TXVECTOR parameter HE_TB_PE_DISAMBIGUITY when transmitting an HE PPDU. Also, the TXVECTOR parameter TB_PE_DISAMBIGUITY may be the TXVECTOR parameter EHT_TB_PE_DISAMBIGUITY when transmitting an EHT PPDU. Also, the PE Disambiguity subfield included in the trigger frame may be set based on whether a preset formula is satisfied.

[0281] T SYM may be the length of an OFDM symbol. SYM may be a value including a guard interval (GI).

[0282] N MA N may be the number of midambles or the number of midamble periods. If the Doppler field is 0, then N MA may be 0. Also, for EHT PPDUs, the Doppler field may be 0 or N MA may be 0. A mid-ample may be inserted in the middle of the data field of a PPDU. A mid-ample may also consist of multiple LTFs. A mid-ample may exist to assist the receiver in channel estimation.

[0283] N LTF may be the number of LTFs included in the preamble, where the LTF may be an HE-LTF when an HE PPDU is transmitted, or an EHT-LTF when an EHT PPDU is transmitted.

[0284] T LTFSYMmay be the length of the OFDM symbol of the LTF. In this case, the LTF may be an HE-LTF when an HE PPDU is transmitted, or an EHT-LTF when an EHT PPDU is transmitted. Also, T LTFSYM may be a value including GI.

[0285] According to the described embodiment, in the absence of mid ampoule, T PE may be determined by Equation 8 below.

[0286]

number

[0287] As shown in FIG. 21, when a trigger frame instructs the STA to transmit a TB PPDU, the STA transmits a T PE A PPDU containing a PE field having a duration of .times. ...

[0288] If a frame including a TRS and a trigger frame instructing the transmission of a PPDU are transmitted together in one PPDU, the values ​​of each field included in the trigger frame may be set so that the duration of the PE field included in the PPDU transmitted in response to the TRS is the same as the default PE duration. For example, the values ​​of the UL Length subfield and the PE Disambiguity subfield of the trigger frame may be adjusted (or set) to set the T PE The value of can be the same as the default PE duration.

[0289] That is, when the transmission of a PPDU is triggered by a trigger frame and a TRS, the duration of the PE field of the PPDU transmitted in response thereto may be set to a value indicated by the default PE duration subfield. PE The value of the field to calculate TPE The value of may be set to be the same as the value indicated by the Default PE Duration subfield.

[0290] For example, if one PPDU contains a trigger frame and a TRS instructing different STAs to transmit TB PPDUs, the maximum duration of the PE field included in the TB PPDU instructed to transmit only by the trigger frame may be 20 us (i.e., if a PE field duration of 20 us is allowed), and the maximum duration of the PE field included in the TB PPDU triggered by the TRS may be 16 us depending on the default PE subfield. In this case, PE The value of the subfields (e.g., LENGTH field and / or PE Disambiguity subfield) used to calculate the duration is calculated by the default PE subfield and the T PE may be set to have the same value.

[0291] In other words, when the transmission of an EHT TB PPDU is instructed by the trigger frame, the duration of the PE field of the EHT TB PPDU may be determined to be one of 0 us, 4 us, 8 us, 12 us, 16 us, or 20 us. However, if the PPDU including the trigger frame also includes a TRS instructing the transmission of an EHT TB PPDU, the default PE duration subfield for the EHT TB PPDU instructed by the TRS may be set to one of 0 us, 4 us, 8 us, 12 us, or 16 us. In this case, the terminal whose transmission of a TB PPDU is triggered by the trigger frame may be STA1, and the terminal whose transmission of a TB PPDU is triggered by the TRS may be STA2.

[0292] In this case, a terminal whose TB PPDU transmission is triggered by a TRS can set the duration of the PE field to a value indicated by the default PE duration included in the action element. However, a terminal whose TB PPDU transmission is triggered by a trigger frame can set the duration of the PE field to a value indicated by the default PE duration included in the action element. However, a terminal whose TB PPDU transmission is triggered by a trigger frame can set the duration of the PE field to a value indicated by the default PE duration included in the action element. PE The value can be set as the duration of the PE field included in the TB PPDU. PE The values ​​of the subfields for calculating the value are the values ​​dictated by the default PE duration and T PE The values ​​may be set to be the same.

[0293] That is, when the maximum value for the duration of the PE field of a TB PPDU according to a trigger frame included in one PPDU and triggering the transmission of a TB PPDU to different STAs is different from the maximum value of the PE field indicated by the default PE duration subfield according to the TRS, the value of the subfield included in the trigger frame for calculating the duration of the PE field included in the TB PPDU may be set (or adjusted) so that the calculated value is the same as the value indicated by the default PE duration subfield.

[0294] In this case, when the default PE duration subfield is set to one of 0 us, 4 us, 8 us, 12 us, or 16 us (or 0 us, 4 us, 8 us, 12 us, 16 us, or 20 us), the T calculated by the trigger frame PE and the value indicated by the Default PE Duration subfield may be the same.

[0295] Therefore, according to an embodiment of the present invention, when a TRS and a trigger frame, which trigger the transmission of a TB PPDU to different STAs, are included in one PPDU, the duration of the PE field included in the PPDU transmitted in response to the TRS and the duration of the PE field included in the PPDU transmitted in response to the trigger frame may be the same. PE and the default PE duration may be the same value.

[0296] According to the above-described embodiment, when responding to a TRS or a trigger frame included in a PPDU containing a TRS, the AP responds by including a PE field with a previously set duration. In this case, the previously set duration may be a default PE duration. Therefore, the AP may set the default PE duration to a sufficiently large value in order to successfully receive a PPDU or successfully respond to a received PPDU. However, as described above, any value of the duration of the PE field may be used only in the previously set configuration. For example, a PE field duration of 20 us may be used only in the previously set configuration. Therefore, in order to use the previously set configuration when responding to a TRS or a trigger frame included in a PPDU containing a TRS, it may be necessary to set a larger value for the default PE duration. For example, in order to use the previously set configuration, it may be necessary to set the default PE duration to 20 us. In this case, it may be necessary to use a long default PE duration even if the previously set configuration is not used, which may be redundant. That is, even for PPDUs that can be received without a long PE field, the long PE field must be included, which may result in a waste of airtime.

[0297] In addition, the maximum value that the default PE duration subfield included in the HE action element can indicate may be 16 us. Therefore, a problem may arise in that it is difficult to trigger a setting that requires a longer PE field using a trigger frame included in a TRS or a PPDU including a TRS. If a reserved value is used for the default PE duration subfield included in the HE action element, the HE STA receiving it will not be able to interpret it and will not be able to operate correctly.

[0298] The following example describes a method for solving this problem.

[0299] FIG. 22 illustrates yet another example of a method for configuring UL MU operation and PE field duration according to an embodiment of the present invention.

[0300] Referring to FIG. 22, to solve the problem described in FIG. 21, the value of the PE field of a PPDU triggered by a trigger frame or TRS may be restricted.

[0301] Specifically, when a response of an STA is triggered, the STA may be instructed to respond using a restricted setting. For example, the STA may be instructed to respond using the restricted setting when triggering using a TRS or a trigger frame included in a PPDU including a TRS. The instructing method may include instructing using a subfield included in the TRS or the trigger frame. The instructing method may also include implicitly instructing when responding to a TRS or a trigger frame included in a PPDU such as a TRS. Such a restricted setting may not require a PE field of a pre-set length. In one embodiment, the pre-set length may be 20 us or more. More specifically, the pre-set length may be 20 us. In another embodiment, the pre-set length may be more than 16 us. Therefore, a STA responding to a TRS or a trigger frame included in a PPDU including a TRS can respond using the restricted setting.

[0302] In this case, the duration of the PE field included in the response PPDU may be shorter than the preset length, for example, 16 us or less.

[0303] Furthermore, the restricted setting may be based on the already set setting described in FIG. 19. For example, the restricted setting may be a setting other than the already set setting described in FIG. 19. Or, the restricted setting may be a setting other than the setting that can use the PE field of the already set duration described in FIG. 19. Or, the restricted setting may be a setting that does not require the PE field of the already set duration described in FIG. 19. For example, the restricted setting may be based on at least one of the following:

[0304] 1) MCS or modulation

[0305] 2) Number of spatial streams

[0306] 3) Channel width, bandwidth, or RU size

[0307] Therefore, according to one embodiment, when transmitting a TRS or a trigger frame included in a PPDU including a TRS, it may be instructed to respond using a previously set MCS index or an MCS index or modulation that is lower than the previously set modulation. Alternatively, when transmitting a TRS or a trigger frame included in a PPDU including a TRS, it may not be necessary to instruct to respond with 4096-QAM. Alternatively, when transmitting a TRS or a trigger frame included in a PPDU including a TRS, it may be instructed to respond with an MCS that does not correspond to 4096-QAM.

[0308] Alternatively, when transmitting a trigger frame included in a TRS or a PPDU including a TRS, the TRS may be instructed to respond using a preset number of spatial streams or less, for example, the preset number may be eight.

[0309] Alternatively, when transmitting a TRS or a trigger frame included in a PPDU containing a TRS, the TRS may be instructed to respond using a channel width, bandwidth, or RU size equal to or smaller than a pre-set size. For example, the pre-set size may be 160 MHz or 320 MHz. Alternatively, the pre-set size may be 2×996 size (number of tones).

[0310] If a trigger frame is transmitted in a PPDU that does not include a TRS, the restricted settings described above do not need to be used.

[0311] Referring to FIG. 22, an AP may transmit a frame including a TRS control. A trigger frame may also be included in a PPDU including such a frame. In this case, the TRS control and the trigger frame may indicate a limited setting. For example, they may not indicate a setting that requires high capability upon reception. Therefore, the PE field included in the EHT TB PPDU responding to the TRS control and the EHT TB PPDU responding to the trigger frame may be 16 us or less. This prevents unnecessary resource consumption due to a long PE field.

[0312] FIG. 23 illustrates yet another example of a method for configuring UL MU operation and PE field duration according to an embodiment of the present invention.

[0313] Referring to Figure 23, when the duration of the PE field of the PPDU indicated by the trigger frame is different from the duration of the PE field of the PPDU indicated by the TRS, the duration of the PE field may be set by the PE duration indicated by the TRS.

[0314] Specifically, the TRS control including the TRS instructing the transmission of a PPDU may indicate the duration of the PE field of the PPDU in a PE Duration subfield. For example, a STA responding to the TRS control field may determine the duration of the PE field included in the responding PPDU based on the PE Duration subfield included in the TRS control field.

[0315] According to one embodiment, the PE Duration subfield can indicate one of the following values: 0, 4, 8, 12, 16, or 20 us. In this case, the PE Duration subfield can be 3 bits. This has the advantage that the PE field of the required duration can be individually indicated each time the TRS triggers the transmission of a PPDU. For example, the required minimum duration can be indicated.

[0316] According to yet another embodiment, the PE Duration subfield may indicate whether or not the use of a 20 us PE field is permitted. In this case, the PE Duration subfield may be 1 bit. This method has the advantage of reducing the number of bits of the PE Duration subfield included in the TRS. According to one embodiment, if the PE Duration subfield included in the TRS control indicates 20 us, the duration of the PE field included in the PPDU may be 20 us. Also, if the PE Duration subfield included in the TRS control does not allow the use of a 20 us PE field, the duration indicated by the Default PE Duration subfield included in the Operation element described in FIGS. 20 and 21 may be set as the duration of the PE field and transmitted in the PPDU.

[0317] The 20 us duration of the PE field may be limited to be used only in EHT TB PPDUs. If responding with an HE TB PPDU, the duration of the PE field cannot be set to 20 us. In this case, the STA can recognize whether the TB PPDU whose transmission is triggered by the TRS or trigger frame is an EHT TB PPDU or an HE TB PPDU based on the TB PPDU format signaling described in Figures 17 and 18. For example, based on the value of a specific field included in the trigger frame, the STA can identify whether the format of the triggered PPDU is an EHT TB PPDU or an HE TB PPDU.

[0318] The TRS control may include signaling indicating whether the PPDU containing the TRS control includes a TRS control or trigger frame configured to require a 20 us PE field. If it is indicated that a TRS control or trigger frame configured to require a 20 us PE field is included, a response may be made using a PPDU including a 20 us PE field. If it is indicated that a TRS control or trigger frame configured to require a 20 us PE field is not included, the duration of the PE field may be set to the default PE duration.

[0319] According to yet another embodiment, when responding to a TRS, it is possible to always respond with a PPDU including a PE field with a preset duration. For example, the preset duration may be 20 us. This embodiment may also be limited to responding with an EHT TB PPDU. If responding with an HE TB PPDU, the 20 us PE field may not be used. That is, when responding with an EHT TB PPDU, a 20 us PE field may be included in the EHT TB PPDU and transmitted, and when responding with an HE TB PPDU, a PE field set according to the default PE duration may be included in the HE TB PPDU and transmitted.

[0320] In the described embodiment, the trigger frame included in the PPDU including the TRS may be set to indicate the duration of the PE field indicated in the described embodiment. For example, the UL Length subfield and the PE Disambiguity subfield of the trigger frame included in the PPDU including the TRS may indicate values ​​that cause the duration of the PE field to be the duration of the PE field indicated in the described embodiment. In this case, the duration of the PE field is set to the T described in FIG. PE may be determined by

[0321] According to an embodiment, multiple TRSs included in one PPDU may indicate the same PE field duration. For example, multiple TRSs included in one PPDU may include PE duration subfields set to the same value. The multiple TRSs may be included in multiple A-MPDUs of the PPDU.

[0322] Figure 23(a) is a diagram showing a TRS control field. Referring to Figure 23(a), the TRS control field may include UL Data Symbols, RU Allocation, AP Tx Power, UL Target RSSI, UL MCS, and PE Duration subfields. The explanation of each subfield may be as explained in Figures 18 to 23. Furthermore, the PE Duration subfield can indicate whether or not to respond with a 20us PE field. In this case, the PE Duration subfield may be 1 bit.

[0323] Referring to FIG. 23(b), an AP may transmit a PPDU including a trigger frame or a frame including a TRS control field. If the PE Duration subfield included in the TRS control field is set to 0, the PE Duration subfield may be set to 0. The PE Duration subfield set to 0 may indicate that 20 us is not used or that the default PE duration is used. Other PE Duration subfields included in a PPDU including a PE Duration subfield set to 0 may also be set to 0. For a trigger frame included in a PPDU including a PE Duration subfield set to 0, the duration of the PE field of a PPDU responding to the trigger frame may be set to the same duration as the PE Duration subfield set to 0. Referring to FIG. 23(b), 1) the PE Duration subfield set to 0, or 2) the duration of the PE field included in a PPDU responding to a trigger frame included in a PPDU including a PE Duration subfield set to 0 may be the default PE duration. Alternatively, the duration of the PE field included in a PPDU responding to a trigger frame included in a PPDU with 1) a PE duration subfield set to 0 or 2) a PE duration subfield set to 0 may be 16 us or less. In this case, the responding PPDU may be an EHT TB PPDU. Alternatively, if responding to a TRS or trigger frame with an EHT TB PPDU, a PE field with a default PE duration may be used.

[0324] Referring to FIG. 23(b), an AP may transmit a PPDU including a trigger frame or a frame including a TRS control field. The PE Duration subfield included in the TRS control field may be set to 1. A PE Duration subfield set to 1 may indicate that 20 us is used or that the default PE duration is not used. Other PE Duration subfields included in a PPDU including a PE Duration subfield set to 1 may also be set to 1. A trigger frame included in a PPDU including a PE Duration subfield set to 1 may have a PE frame duration in a PPDU responding to the trigger frame set to the same duration as the PE Duration subfield set to 1. Referring to FIG. 23(b), the duration of the PE field included in a PPDU responding to a trigger frame included in a PPDU including 1) a PE Duration subfield set to 1, or 2) a PE Duration subfield set to 1 may be 20 us. Alternatively, the duration of the PE field included in a PPDU responding to a trigger frame included in a PPDU including 1) a PE duration subfield set to 1, or 2) a PE duration subfield set to 1, may not be the default PE duration. In this case, the responding PPDU may be an EHT PPDU. Alternatively, the responding PPDU may be an EHT TB PPDU. That is, the response may be limited to an EHT TB PPDU.

[0325] FIG. 24 illustrates yet another example of a method for configuring UL MU operation and PE field duration according to an embodiment of the present invention.

[0326] 24, the duration of the PE field included in the TB PPDU may be set to a value indicated by a PE Duration field indicated by a TRS control field or a value indicated by a Default PE Duration subfield included in an Action element. Alternatively, when the TB PPDU is triggered only by a trigger frame, the duration of the PE field of the TB PPDU may be set according to specific conditions (MCS method, RU size, number of spatial streams used, and / or indicated PPDU format (e.g., whether an EHT TB PPDU or an HE TB PPDU is indicated)).

[0327] For example, a duration of 20 us may be allowed for the PE field only when the TB PPDU satisfies the aforementioned specific conditions (e.g., when it is designated as an EHT TB PPDU, when eight or more spatial streams are used, or when the size of at least one RU is greater than 2x996, when the bandwidth over which the EHT PPDU (or EHT MU PPDU, etc.) is transmitted is 320 MHz, or when the PPDU is modulated with 4096-QAM, etc.).

[0328] If the transmission of a PPDU is instructed by the TRS, the duration of the PE field included in the PPDU may be set to a value indicated by a default PE duration subfield included in an operation element (e.g., an HE operation element or an EHT operation element) or indicated by a PE duration subfield included in the TRS control field.

[0329] If a TRS and a trigger frame are included in one PPDU and both indicate the transmission of the PPDU, and if the maximum value of the duration of the PE field when the PPDU is indicated by the trigger frame is the same as the maximum value of the duration of the PE field when indicated by the TRS, it may be set to the value indicated by the default PE duration subfield or the value indicated by the PE duration subfield included in the TRS.

[0330] However, when a TRS and a trigger frame are included in one PPDU and both indicate transmission of the PPDU, the duration of the PE field when the PPDU is indicated by the trigger frame and the maximum value of the PE field duration indicated by the default PE duration subfield when indicated by the TRS may not be the same. For example, if the TB PPDU indicated by the trigger frame and / or TRS meets a specific condition, the maximum value of the PE field duration may be a first maximum value (e.g., 20 us), and the maximum value of the PE field duration indicated by the default PE subfield included in the action element may be a second maximum value (e.g., 16 us). In this case, the duration of the PE field may be set to the value indicated by the default PE subfield or the value indicated by the PE subfield included in the TRS.

[0331] In this case, the PE Duration subfield can indicate that the maximum duration of the PE field is allowed to be 20 us, or can indicate that the duration of the PE field should be set to the value of the Default PE Duration subfield included in the Action element.

[0332] In other words, according to an embodiment of the present invention, the duration of the PE field may be determined based on the PPDU format used in response to a TRS. According to an embodiment, when responding to a TRS with an HE PPDU, the duration of the PE field may be the HE default PE duration. Also, when responding to a TRS with an EHT PPDU, the duration of the PE field may be a value indicated by the EHT default PE duration. For example, the HE PPDU may be an HE TB PPDU. Or the HE PPDU may be an HE SU PPDU. Or the EHT PPDU may be an EHT TB PPDU. Or the EHT PPDU may be an EHT MU PPDU. Also, the HE default PE duration may be the default PE duration described in FIG. 20 and FIG. 21. For example, the HE default PE duration may be a value indicated by an HE action element. More specifically, the HE default PE duration may be a value indicated in a default PE duration subfield included in an HE action element.

[0333] Also, the EHT default PE duration may be a value indicated by an EHT operation element. More specifically, the EHT default PE duration may be a value indicated by an EHT default PE duration subfield included in the EHT operation element.

[0334] According to one embodiment, the EHT Default PE Duration subfield may indicate whether the duration of the PE field is 20 us, in which case the EHT Default PE Duration subfield may be 1 bit.

[0335] According to another embodiment, the EHT default PE duration subfield can indicate whether the duration of the PE field is the same as the HE default PE duration. In this case, the EHT default PE duration subfield can be 1 bit. For example, if the EHT default PE duration subfield indicates that the duration of the PE field is the same as the HE default PE duration, the EHT default PE duration can be the default PE duration indicated by the HE operation element. Also, if the EHT default PE duration subfield indicates that the duration of the PE field is not the same as the HE default PE duration, the EHT default PE duration can be 20 us.

[0336] According to another embodiment, the EHT Default PE Duration subfield can indicate whether the duration of the PE field is 0, 4, 8, 12, 16, or 20 us. In this case, the EHT Default PE Duration subfield can be 3 bits.

[0337] According to yet another embodiment, the EHT default PE duration may be 20 us.

[0338] Referring to Figure 24(a), the HE operation element may include a default PE duration subfield. Also, the default PE duration subfield may be included in the HE operation parameters field included in the HE operation element. Figure 24(a) may be the same as Figure 20(b).

[0339] 24(b), the EHT operation element may include an EHT default PE duration subfield. The EHT default PE duration subfield may be included in an EHT operation parameter field included in the EHT operation element. For example, the EHT default PE duration subfield may be 1 bit.

[0340] Referring to FIG. 24(c), there may be cases where an HE PPDU is transmitted in response to a TRS control, and cases where an EHT PPDU is transmitted. If an HE PPDU is transmitted as a response, the duration of the PE field included in the HE PPDU may be the default PE duration. The default PE duration may be the value indicated in FIG. 24(a). The default PE duration may be a value of 16 us or less. If an EHT PPDU is transmitted as a response, the duration of the PE field included in the EHT PPDU may be the EHT default PE duration. The EHT default PE duration may be set based on the EHT operation element or the HE operation element. For example, the EHT default PE duration may be set to 1) a pre-set value based on the EHT default PE duration subfield included in the EHT operation element, or 2) a value based on the default PE duration subfield included in the HE operation element. The pre-set value may be 20 us. Referring to FIG. 24(c), when responding to TRS control with an EHT PPDU, the PPDU can be transmitted including a 20 us PE field.

[0341] According to an embodiment of the present invention, multiple PPDUs may be multiplexed in the frequency domain. Such multiple PPDUs may be referred to as an A-PPDU (aggregated PPDU). When an A-PPDU is transmitted, multiple PPDUs may be transmitted simultaneously. For example, an HE PPDU and an EHT PPDU may constitute an A-PPDU. More specifically, an HE TB PPDU and an EHT TB PPDU may constitute an A-PPDU. For example, an A-PPDU composed of an HE TB PPDU and an EHT TB PPDU may be triggered to be transmitted by multiple STAs.

[0342] According to an embodiment of the present invention, the durations of the PE fields included in the PPDUs constituting the A-PPDU may be the same. For example, the durations of the PE fields included in the HE TB PPDU and the EHT TB PPDU may be the same. In this case, the method for setting the durations may be the same as the methods described with reference to Figures 20 to 24. This may simplify the operation of the STA receiving the A-PPDU.

[0343] As another example, when one STA transmits an A-PPDU consisting of an HE PPDU and an EHT PPDU, the duration of the included PE field may be the same, which allows for simple implementation when configuring the A-PPDU.

[0344] According to an embodiment of the present invention, a PPDU other than a TB PPDU can also be transmitted in response to a trigger frame or a TRS. For example, an SU PPDU or an MU PPDU can be transmitted. For example, the MU PPDU may be an EHT MU PPDU or an HE MU PPDU. The SU PPDU may be an HE SU PPDU or a non-HT PPDU. According to an embodiment, the duration of the PE field may be set differently depending on whether a TB PPDU or a PPDU other than a TB PPDU is transmitted in response to a trigger frame or a TRS. For example, when a TB PPDU is transmitted, the duration setting methods described with reference to FIGS. 20 to 24 can be used. Furthermore, when a PPDU other than a TB PPDU is transmitted, the nominal PE duration can be set as the duration.

[0345] FIG. 25 illustrates an example of a method for setting the CS Required subfield according to an embodiment of the present invention.

[0346] Referring to FIG. 25, carrier sense (CS) can be performed when responding to a trigger frame. For example, when a trigger frame is received, an STA can determine whether to respond to the trigger frame based on the CS result. Here, CS may include physical CS and virtual CS. Physical CS may include clear channel assessment (CCA). For example, physical CS performed when determining whether to respond to a trigger frame may be energy detection (ED). Also, virtual CS may refer to consideration of NAV. CS performed when determining whether to respond to a trigger frame may be performed during (or within) a SIFS time from (or after) the end of a PPDU including the trigger frame.

[0347] According to an embodiment of the present invention, there may be signaling instructing that a response to a trigger frame should be determined based on a CS result. For example, the CS Required subfield included in the trigger frame shown in FIG. 16 may be signaling instructing that a response to a trigger frame should be determined based on a CS result. For example, if the CS Required subfield is set to 1, a response to a trigger frame including the CS Required subfield can be determined based on a CS result.

[0348] For example, when the CS Required subfield is set to 1, if the CS result is busy when responding to a trigger frame including the CS Required subfield, the device does not need to respond to the trigger frame. When the CS Required subfield is set to 1, if the CS result is idle when responding to a trigger frame including the CS Required subfield, the device may respond to the trigger frame. For example, when the CS Required subfield is set to 0, the device can determine whether to respond to a trigger frame including the CS Required subfield regardless of the CS result. When the CS result is busy, it may mean that at least one of the physical CS and the virtual CS is busy. When the CS result is idle, it may mean that both the physical CS and the virtual CS are idle.

[0349] Also, when responding to the TRS control field, it is possible to determine whether to respond without relying on the CS result.

[0350] In addition, a trigger frame included in the same PPDU as the TRS control field can set the CS Required subfield to 0 or 1. Alternatively, a trigger frame included in the same PPDU as a frame containing the TRS control field can set the CS Required subfield to 0 or 1.

[0351] As shown in Figure 25, a trigger frame and a frame including TRS control may be transmitted in the same PPDU. In this case, the CS Required subfield included in the trigger frame may be set to 0. Therefore, a response to the trigger frame can be made without being based on the CS result. Also, a response to the TRS control can be made without being based on the CS result.

[0352] According to an embodiment of the present invention, the CS Required subfield may be set when transmitting a trigger frame. For example, the CS Required subfield may be set based on the length of the response indicated by the trigger frame. The UL Length subfield shown in FIG. 16 may indicate the length of the response indicated by the trigger frame. The length of the TB PPDU responding to the trigger frame may be based on the UL Length subfield value included in the trigger frame. Furthermore, setting the CS Required subfield based on the UL Length subfield may be limited to cases where the trigger frame is of a previously set type. The type of the trigger frame may be indicated by the Trigger Type subfield shown in FIG. 16. For example, if the trigger frame is a Basic, BSRP, MU-BAR, BQRP, GCR MU-BAR, or BFRP trigger frame, the CS Required subfield may be set based on the UL Length subfield.

[0353] According to one embodiment, if the UL Length subfield value is less than or equal to a pre-set value (smaller or equal), the CS Required subfield may be set to 0 or 1. As a more specific example, if the UL Length subfield value is less than or equal to a pre-set value, the CS Required subfield may be set to 0. Also, if the UL Length subfield value exceeds (is greater than) the pre-set value, the CS Required subfield may be set to 1. If the UL Length subfield value exceeds (is greater than) the pre-set value, the CS Required subfield does not need to be set to 0.

[0354] According to one embodiment of the present invention, the preset value may be 418. For example, when a condition based on the UL Length subfield is used together with the following condition 1 or condition 2, the preset value may be 418.

[0355] (Condition 1) The RA (receiver address) of the trigger frame is the MAC address of an individually addressed STA, and the trigger frame is aggregated into one A-MPDU with either 1) a QoS Data frame whose Ack Policy is set to respond with an acknowledgment in a TB PPDU (HETP Ack), or 2) a Management frame soliciting an acknowledgment.

[0356] (Condition 2) The trigger frame is an MU-BAR or GCR MU-BAR trigger frame.

[0357] Condition 1 may be used in conjunction with conditions where the trigger frame is Basic, BSRP, MU-BAR, BQRP, or GCR MU-BAR.

[0358] The pre-set value 418 may be a value corresponding to the PPDU length 584 us. Also, 584 us may be the maximum TB PPDU duration that can be specified by TRS control. 584 us may be the maximum HE TB PPDU duration that can be specified by TRS control. 584 us may be the sum of the lengths of the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, HE-STF, HE-LTF, Data field, and PE field of the TB PPDU. The L-STF, L-LTF, L-SIG, and RL-SIG may be 8 us, 8 us, 4 us, and 4 us, respectively. The HE-SIG-A may be 8 us. The HE-STF may be 8 us for the TB PPDU. The HE-LTF is a TB PPDU that responds to TRS control and may be 16 us. 4x HE-LTF with a GI (guard interval) of 3.2 us may be 16 us. The maximum value of the Data field that can be specified by the TRS control may be the value specified as the maximum number of symbols having a GI of 3.2 us. If the maximum number of symbols that can be specified is 32 symbols, the maximum value of the Data field that can be specified by the TRS control may be 32*16 us, i.e., 512 us. Also, the maximum value of the PE field may be 16 us. Therefore, the maximum TB PPDU duration that can be specified by the TRS control may be (8 + 8 + 4 + 4 + 8 + 8 + 16 + 512 + 16) us, i.e., 584 us.

[0359] Therefore, the trigger frame included in the same PPDU as the frame including the TRS control can set the CS Required subfield to 0 based on whether the UL Length subfield value is 418 or less. This is because the trigger frame and the frame including the TRS control included in the same PPDU must indicate the same response TB PPDU duration. Therefore, the trigger frame included in the same PPDU as the frame including the TRS control indicates a length less than the maximum length that the TRS control can indicate, and the UL Length subfield value is less than the previously set value of 418, so the CS Required subfield can be set to 0. The embodiment shown in FIG. 25 may also set the CS Required subfield to 0 using the method described above.

[0360] If the CS Required subfield of a trigger frame included in the same PPDU as a frame containing TRS control is set to 1, STAs responding to TRS control will respond without basing their responses on the CS result, while STAs responding to the trigger frame will respond based on the CS result. This could result in the resources allocated by the trigger frame being wasted if a STA is unable to respond to the trigger frame.

[0361] According to another embodiment, the preset value may be 76. For example, when the condition based on the UL length subfield is used together with the following condition 1 or condition 2, the preset value may be 76.

[0362] (Condition 1) The trigger frame is a Basic, BSRP, MU-BAR, BQRP, or GCR MU-BAR trigger frame.

[0363] (Condition 2) The trigger frame is a BFRP trigger frame.

[0364] The pre-set value 76 may be a value corresponding to 128 us, which may be the duration of an HE TB PPDU having a 4x HE-LTF and PE field.

[0365] In an embodiment of the present invention, the preset value of the length corresponding to Time us may be calculated by the following Equation 9 or 10.

[0366]

number

[0367]

number

[0368] In an embodiment of the present invention, Ceil(x) may be the smallest integer greater than or equal to x. SignalExtention may be the length of the signal extension. The length of the signal extension may be 0 us in the 5 GHz band or 6 GHz band. The length of the signal extension may be 6 us in the 2.4 GHz band.

[0369] 26 shows an example of the setting of the CS Required subfield and the UL MU operation according to one embodiment of the present invention. In FIG. 26, the same content as that explained in FIG. 1 to FIG. 25 is omitted.

[0370] According to the above-described embodiment, there may be a case where the trigger frame indicates a response with an HE TB PPDU or a case where the trigger frame indicates a response with an EHT TB PPDU, and there may be a case where the TRS control indicates a response with an HE TB PPDU or a case where the trigger frame indicates a response with an EHT TB PPDU.

[0371] According to an embodiment of the present invention, the maximum TB PPDU duration that can be indicated by the TRS control field indicating an EHT TB PPDU response may be different from the maximum TB PPDU duration that can be indicated by the TRS control field indicating an HE TB PPDU response. For example, the maximum TB PPDU duration that can be indicated by the TRS control field indicating an EHT TB PPDU response may be longer than the maximum TB PPDU duration that can be indicated by the TRS control field indicating an HE TB PPDU response. This is because, as described above, the EHT PPDU may include a 20 us PE field. Alternatively, this may be because the length indication method of the TRS control field indicating an EHT TB PPDU response is different from that of the TRS control field indicating an HE TB PPDU response.

[0372] Therefore, even when indicating an EHT TB PPDU when setting the CS Required subfield based on the UL Length subfield, using the same pre-set value (threshold) as described in FIG. 25 may result in wasted resources.

[0373] For example, when responding to a TRS control that indicates an EHT TB PPDU response, it is possible to respond without relying on the CS result. There may be a case where the trigger frame is included in the same PPDU as a frame containing a TRS control that solicits an EHT TB PPDU response. In this case, the trigger frame and the TRS control that indicates an EHT TB PPDU response can indicate the same response length.

[0374] In this case, the trigger frame can set the CS Required subfield based on a value based on the maximum EHT TB PPDU length that can be specified by the TRS control, as described in Figure 25. In this case, the trigger frame can set the CS Required subfield based on a value smaller than the maximum EHT TB PPDU length that can be specified by the TRS control. Therefore, since the UL Length subfield value included in the trigger frame is larger than the pre-set value used when setting the CS Required subfield, the CS Required subfield can be set to 1.

[0375] As shown in FIG. 26, the trigger frame may set the CS Required subfield to 1. Also, there may be a TRS control included in the same PPDU as the trigger frame. In this case, the TRS control and the trigger frame may indicate an EHT TB PPDU. In this case, a STA responding to the TRS control responds with an EHT TB PPDU regardless of the CS result, and a STA responding to the trigger frame can determine whether to respond with an EHT TB PPDU based on the CS result. Therefore, a STA responding to the trigger frame may not be able to respond because the CS result is busy. In this case, resources allocated by the trigger frame may be wasted. Since some of the resources are used to respond to the TRS control, it may be difficult for other STAs to use the resources.

[0376] FIG. 27 illustrates yet another example of the configuration of the CS Required subfield and the UL MU operation according to an embodiment of the present invention.

[0377] The embodiment of Figure 27 may be a method for solving the problems described in Figures 25 and 26. In addition, in the embodiment of Figure 27, the above-described content may be omitted.

[0378] According to an embodiment of the present invention, the pre-set value used when setting the CS Required subfield based on the UL Length subfield described in Figures 25 and 26 may differ depending on which TB PPDU the trigger frame indicates. Alternatively, the pre-set value used when setting the CS Required subfield based on the UL Length subfield may differ depending on which TB PPDU the TRS control included in the same PPDU indicates. According to an embodiment, when the trigger frame or TRS control solicits an HE TB PPDU, the pre-set value may be threshold 1, and when the trigger frame or TRS control solicits an EHT TB PPDU, the pre-set value may be threshold 2.

[0379] Alternatively, according to one embodiment of the present invention, when an EHT TB PPDU is indicated, the pre-set value may be threshold 1. Also, the pre-set value may be determined by using the methods described with reference to Figures 22 to 24. For example, when an EHT TB PPDU is presented and the PE duration is 16 us or less, the pre-set value may be threshold 1. When an EHT TB PPDU is presented and the PE duration is 20 us, the pre-set value may be threshold 2.

[0380] According to one embodiment, the threshold 1 may be a preset value as described in Fig. 25. That is, the threshold 1 may be 418 or 76, and the preset value may be 418 or 76 depending on the conditions as described in Fig. 25.

[0381] According to one embodiment, threshold 2 may be a value greater than threshold 1. This is because the maximum duration of a TB PPDU that can be instructed by the TRS control presenting an EHT TB PPDU is greater than the maximum duration of a TB PPDU that can be instructed by the TRS control presenting an HE TB PPDU. For example, threshold 2 may be equal to the length value calculated by substituting the value of Time calculated by Equation 11 for Time in Equation 9 or 10.

[0382]

number

[0383] In the above Equation 11, the L-STF length may be 8 us, the L-LTF length may be 8 us, the L-SIG length may be 4 us, the RL-SIG length may be 4 us, the U-SIG length may be 8 us, and the EHT-STF length may be 8 us.

[0384] The EHT-LTF length may be 4x the EHT-LTF length with a GI of 3.2 us, so the EHT-LTF length may be 16 us.

[0385] The Data field length may be based on the maximum length that can be specified by the TRS control presenting the EHT TB PPDU. For example, the Data field length may be based on the maximum number of OFDM symbols that can be specified by the TRS control presenting the EHT TB PPDU. The Data field length may be based on the maximum number of OFDM symbols that can be specified by the TRS control presenting the EHT TB PPDU multiplied by the OFDM symbol length. The Data field length may be based on the maximum number of OFDM symbols that can be specified by the TRS control presenting the EHT TB PPDU multiplied by the maximum OFDM symbol length. The maximum number of OFDM symbols may be 32. The maximum OFDM symbol length may be a symbol length using a GI of 3.2 us. The maximum OFDM symbol length may be 16 us. Therefore, the Data field length may be 32*16 us (512 us).

[0386] According to one embodiment, the maximum length that can be indicated by the TRS control presenting the EHT TB PPDU may be the same as the maximum length that can be indicated by the TRS control presenting the HE TB PPDU. The maximum length that can be indicated by the TRS control presenting the EHT TB PPDU may be the same as the maximum number of OFDM symbols that can be indicated by the TRS control presenting the HE TB PPDU. This allows the EHT STA to perform the same operation as the HE STA based on the TRS control, which may facilitate implementation of the EHT STA.

[0387] According to another embodiment, the maximum length that can be indicated by the TRS control soliciting the EHT TB PPDU may be different from the maximum length that can be indicated by the TRS control soliciting the HE TB PPDU. The maximum length that can be indicated by the TRS control soliciting the EHT TB PPDU may be different from the maximum number of OFDM symbols that can be indicated by the TRS control soliciting the HE TB PPDU. This is because the space of signaling that the TRS control can include is limited. For example, the TRS control soliciting the EHT TB PPDU may include signaling that the TRS control soliciting the HE TB PPDU does not include. Therefore, the TRS control soliciting the EHT TB PPDU may define a different maximum length that can be indicated or a different resolution of the length that can be indicated than the TRS control soliciting the HE TB PPDU.

[0388] According to one embodiment, the PE field length may be the maximum PE field length. The PE field length may be 20 us. According to another embodiment, the PE field length may be the PE field length according to the method described in FIGS. 22-24. For example, the PE field length may be 16 us when using a PE field of 16 us or less according to the method described in FIGS. 22-24. Alternatively, the PE field length may be 20 us when using a PE field of 20 us according to the method described in FIGS. 22-24.

[0389] Thus, according to the described embodiment, the Time value may be as follows:

[0390]

number

[0391] Also, in Equation 12, when the Time value is substituted into Equation 10, threshold 2 may be 421.

[0392] In conjunction with the embodiment described in FIG. 25, the following applies: A trigger frame presenting an EHT TB PPDU can set the CS Required subfield to 1 if the UL Length subfield is greater than threshold 2. Also, a trigger frame presenting an EHT TB PPDU can set the CS Required subfield to 0 or 1 if the UL Length subfield is equal to or less than threshold 2. Threshold 2 may be a value greater than 418. Threshold 2 may be 421. Threshold 2 may also be used together with the conditions described in FIG. 25. For example, when a condition based on the UL Length subfield is used together with the following condition 1 or condition 2, threshold 2 (e.g., 421 value) can be used.

[0393] (Condition 1) The RA (receiver address) of the trigger frame is the MAC address of an individually addressed STA, and the trigger frame is aggregated into one A-MPDU with either 1) a QoS Data frame whose Ack Policy is set to respond with an acknowledgment in a TB PPDU (HETP Ack), or 2) a Management frame that indicates an acknowledgment.

[0394] (Condition 2) The trigger frame is an MU-BAR or GCR MU-BAR trigger frame.

[0395] Condition 1 may be used in conjunction with conditions where the trigger frame is Basic, BSRP, MU-BAR, BQRP, or GCR MU-BAR.

[0396] That is, when indicating an EHT TB PPDU under the condition that the pre-set value of 418 is used when presenting an HE TB PPDU, the pre-set value of 421 can be used instead of 418.

[0397] According to another embodiment, the threshold 2 may be 79. The threshold 2 value 79 may be a value corresponding to 132 us. The threshold 2 value 79 may be a length value obtained by substituting 132 us for the Time value in Equation A or Equation B. Also, 132 us may be the duration of an EHT TB PPDU having a 4x EHT-LTF and PE field.

[0398] In conjunction with the embodiment described in FIG. 25, the following applies: A trigger frame presenting an EHT TB PPDU can set the CS Required subfield to 1 if the UL Length subfield is greater than threshold 2. Also, a trigger frame presenting an EHT TB PPDU can set the CS Required subfield to 0 or 1 if the UL Length subfield is equal to or less than threshold 2. Threshold 2 may be a value greater than 76. Threshold 2 may be 79. Threshold 2 may also be used together with the conditions described in FIG. 25. For example, threshold 2 (e.g., a value of 79) can be used when a condition based on the UL Length subfield is used together with the following condition 1 or condition 2.

[0399] (Condition 1) The trigger frame is a Basic, BSRP, MU-BAR, BQRP, or GCR MU-BAR trigger frame.

[0400] (Condition 2) The trigger frame is a BFRP trigger frame.

[0401] That is, when an EHT TB PPDU is presented under the condition that the preset value of 76 is used when an HE TB PPDU is presented, the preset value of 79 can be used instead of 76.

[0402] As shown in FIG. 27, the trigger frame may be transmitted in the same PPDU as the frame containing the TRS control.

[0403] The trigger frame and TRS control included in the sequence indicated as Sequence 1 may present an HE TB PPDU. Therefore, the PE field included in the presented HE TB PPDU may be 16 us or less. In addition, the trigger frame included in Sequence 1 may set the CS Required subfield based on threshold 1. For example, the trigger frame included in Sequence 1 may set the CS Required subfield based on whether the UL Length subfield value is less than or equal to threshold 1. Threshold 1 may be 418 or 76. If the UL Length subfield value is less than or equal to threshold 1, the trigger frame included in Sequence 1 may set the CS Required subfield to 0 or 1. Therefore, the CS Required subfield can be set to 0. If the UL Length subfield value is greater than threshold 1, the trigger frame included in Sequence 1 may set the CS Required subfield to 1. Therefore, the CS Required subfield may not be set to 0. Thus, in the illustrated embodiment, both the STAs responding to the TRS control and the STAs responding to the trigger frame are not based on the CS result and can transmit TB PPDU responses when scheduled.

[0404] The trigger frame and TRS control included in the sequence indicated as Sequence 2 may present an EHT TB PPDU. Therefore, the PE field included in the presented EHT TB PPDU may be 20 us or less. In addition, the trigger frame included in sequence 2 may set the CS Required subfield based on threshold 2. As a more specific example, when the trigger frame included in sequence 2 presents a TB PPDU response including a PE field of 20 us, it may set the CS Required subfield based on threshold 2. For example, when the trigger frame included in sequence 2 presents a TB PPDU response including a PE field of 16 us or less, it may set the CS Required subfield based on threshold 1. The following may be an example where threshold 2 is used. For example, the trigger frame included in sequence 2 may set the CS Required subfield based on whether the UL Length subfield value is less than or equal to threshold 2. Threshold 2 may be 421 or 79. If the UL Length subfield value of the trigger frame included in sequence 2 is less than or equal to threshold 2, the CS Required subfield can be set to 0 or 1. Therefore, the CS Required subfield can be set to 0. Therefore, if a frame including TRS control is included in the same PPDU as the trigger frame, the UL Length subfield of the trigger frame should be set to a value less than threshold 2, and therefore the CS Required subfield included in the trigger frame can be set to 0. Therefore, as described in FIG. 26, the problem of resource wastage can be solved because the STA responding to the TRS control transmits a TB PPDU regardless of the CS result, and the STA responding to the trigger frame does not respond with a TB PPDU based on the CS result.For example, if the trigger frame included in sequence 2 has a UL Length subfield value greater than threshold 2, the CS Required subfield can be set to 1. Therefore, the CS Required subfield may not be set to 0. Therefore, in the illustrated embodiment, both the STA responding to the TRS control and the STA responding to the trigger frame can transmit a TB PPDU response when scheduled, regardless of the CS result.

[0405] According to another embodiment, threshold 2 may be a value smaller than threshold 1. In this case, there is an advantage that it is possible to prevent the CS Required subfield from being set to 1 unnecessarily for a short PPDU or a short frame. For example, if the maximum response length or the maximum number of OFDM symbols that can be specified by the TRS control indicating the EHT TB PPDU is smaller than that of the TRS control indicating the HE TB PPDU, threshold 2 may be smaller than threshold 1. For example, if the maximum number of OFDM symbols that can be specified by the TRS control presenting the EHT TB PPDU is 16, threshold 2 may be equal to the value obtained by substituting the following Time value into Equation 9 or 10.

[0406] Time=8+8+4+4+8+8+16+16*16+16=328

[0407] Time=8+8+4+4+8+8+16+16*16+20=332

[0408] Therefore, threshold 2 can be 226 or 229.

[0409] FIG. 28 illustrates an example of a method for setting the PE field when using an A (aggregated)-PPDU according to an embodiment of the present invention.

[0410] As described in FIG. 24, the PPDUs included in the A-PPDU may have the same duration of the PE field. Therefore, the duration of the PE field included in the EHT PPDU included in the A-PPDU may be 16 us or less. More specifically, the duration of the PE field included in the EHT TB PPDU included in the A-PPDU may be 16 us or less. More specifically, the duration of the PE field included in the EHT TB PPDU included in the A-PPDU may be set to the Default PE Duration subfield value included in the HE Operation element.

[0411] To achieve this, when transmitting a TRS control indicating an EHT TB PPDU transmitted as (or constituting) an A-PPDU, the signaling indicating the PE duration can be set to a value of 16 us or less. Alternatively, when transmitting a TRS control indicating an EHT TB PPDU transmitted as (or constituting) an A-PPDU, the signaling indicating the PE duration can be set to use the Default PE Duration subfield value included in the HE Operation element as the duration of the PE field.

[0412] Alternatively, when responding to a TRS control indicating an EHT TB PPDU transmitted as (or constituting) an A-PPDU, the PE duration of the transmitted PE field can be set to a value of 16 us or less. This requires the responding STA to know whether the TB PPDU transmission is transmitted as (or constituting) an A-PPDU.

[0413] Alternatively, the TRS control indicating the EHT TB PPDU need not be included in the PPDU when indicating the A-PPDU, since there is no way to know whether the responding STA will respond to the A-PPDU, and also because the TRS control does not include signaling to indicate the PE duration.

[0414] In the embodiment of FIG. 28, the same contents as those explained in FIGS. 1 to 27 may be omitted.

[0415] According to an embodiment of the present invention, the pre-set value used when setting the CS Required subfield based on the UL Length subfield described with reference to Figures 25 to 27 may differ depending on whether the trigger frame indicating the EHT TB PPDU indicates an EHT TB PPDU included in an A-PPDU or presents an EHT TB PPDU not included in an A-PPDU. That is, the pre-set value used when setting the CS Required subfield based on the UL Length subfield of the trigger frame indicating the EHT TB PPDU may differ depending on whether the PPDU including the trigger frame includes a frame indicating an EHT TB PPDU.

[0416] According to an embodiment of the present invention, when a trigger frame indicating an EHT TB PPDU is not included in an A-PPDU, the method described in Figure 27 can be used. That is, when a trigger frame indicating an EHT TB PPDU is not included in an A-PPDU, threshold 2 described in Figure 27 can be used. More specifically, when a trigger frame indicating an EHT TB PPDU is not included in an A-PPDU, the CS Required subfield can be set based on the pre-set value 421 or 79 described in Figures 25 to 27.

[0417] Furthermore, when a trigger frame indicating an EHT TB PPDU is included in an A-PPDU, the methods described in Figures 25 and 26 can be used. Alternatively, when a trigger frame indicating an EHT TB PPDU is included in an A-PPDU, threshold 1 described in Figure 27 can be used. More specifically, when a trigger frame indicating an EHT TB PPDU is included in an A-PPDU, the CS Required subfield can be set based on the pre-set value of 418 or 76 described in Figures 25 to 27. When a trigger frame indicating an EHT TB PPDU is included in an A-PPDU, the CS Required subfield can be set based on the same pre-set value as in the case of a trigger frame indicating an EHT TB PPDU.

[0418] Referring to FIG. 28, one frame included in one PPDU or multiple frames included in one PPDU may indicate an A-PPDU. For example, an HE TB PPDU and an EHT TB PPDU may be simultaneously indicated. For example, referring to sequence 1, a PPDU may include a TRS control indicating an HE TB PPDU and a TRS control indicating an EHT TB PPDU. In this case, the PPDU responding to the TRS control indicating the HE TB PPDU and the PE field of the PPDU responding to the TRS control indicating the EHT TB PPDU may have the same duration. The same duration may be 16 us or less. Alternatively, the same duration may be a value indicated by a Default PE Duration subfield included in the HE Operation element.

[0419] Referring to Sequence 2, the trigger frame may solicit an EHT TB PPDU constituting an A-PPDU. In this case, the CS Required subfield included in the trigger frame may be set based on threshold 1 described in FIG. 27. Threshold 1 may be a pre-set value used when setting the CS Required subfield included in the trigger frame indicating the HE TB PPDU based on the UL Length subfield value. Threshold 1 may be 418 or 76. The trigger frame indicating the EHT TB PPDU may indicate a response of the same length as the TRS control indicating the HE TB PPDU or the trigger frame indicating the HE TB PPDU. Furthermore, the trigger frame indicating the EHT TB PPDU may set the CS Required subfield based on the same pre-set value as the trigger frame indicating the HE TB PPDU. Therefore, the CS Required subfield may be set to the same value in the trigger frame indicating the EHT TB PPDU and the trigger frame indicating the HE TB PPDU. Furthermore, when a trigger frame indicating an EHT TB PPDU is transmitted together with a TRS control indicating an HE TB PPDU and the CS Required subfield is set based on threshold 1, the CS Required subfield can be set to 0 or 1. That is, the CS Required subfield can be set to 0. Therefore, among the A-PPDUs proposed according to the embodiment of the present invention, it is possible to prevent a situation in which the HE TB PPDU is transmitted without based on the CS result and the EHT TB PPDU determines whether to respond based on the CS result.

[0420] FIG. 29 illustrates an example of a method for indicating a TB PPDU format according to an embodiment of the present invention.

[0421] As described in the above embodiment, a method for indicating the format of the PPDU to be responded to by a frame that triggers the PPDU may be necessary. For example, the PPDU format may indicate the TB PPDU format. The embodiment of FIG. 29 may be a specific example of the above-described TB PPDU format indication method. In this embodiment, the above content may be omitted.

[0422] According to an embodiment of the present invention, the format of a PPDU responding to a trigger frame can be determined based on a User Info field included in the trigger frame. Alternatively, the format of a PPDU responding to a trigger frame can be indicated by the User Info field included in the trigger frame. In the present invention, the User Info field that determines and indicates the format of a PPDU can be referred to as a Special User Info field.

[0423] According to one embodiment, the Special User Info field may be a User Info field in which the AID12 subfield included in the Special User Info field is set to a pre-set value. For example, the pre-set value may be 2007. The pre-set value may be a value that the AP does not assign as an AID (association ID). The Special User Info field may have a different format from other User Info fields. That is, the subfields included in the Special User Info field may be different from those included in other User Info fields. The Special User Info field and other User Info fields may both include an AID12 subfield at the same position. For example, the first 12 bits of the Special User Info field and User Info fields other than the Special User Info field may be the AID12 subfield. For example, B0 to B11 of the Special User Info field and User Info fields other than the Special User Info field may be the AID12 subfield.

[0424] The trigger frame may also include a subfield indicating whether or not a Special User Info field is included. The subfield indicating whether or not a Special User Info field is included may be referred to as a Special User Info Field Present subfield. For example, the Special User Info Field Present subfield may be present in the Common Info field. For example, bit B55 of the Common Info field may be the Special User Info Field Present subfield. If the Special User Info Field Present subfield is set to 1, the trigger frame may not include the Special User Info field. If the Special User Info Field Present subfield is set to 0, the trigger frame may include the Special User Info field. This is because the 802.11ax standard sets B55 of the Common Info field to the already-defined value of 1.

[0425] A STA receiving a trigger frame can determine whether a Special User Info field is included based on the Special User Info Field Present subfield, making it easier to implement the determination of whether a Special User Info field is included compared to when the Special User Info Field Present subfield is not present. Furthermore, when a trigger frame is received by a STA that is not associated with the AP that sent the trigger frame, the AID12 subfield can be set to a pre-configured value indicating the Special User Info field. The STA can determine whether the User Info field is a Special User Info field (whether it actually indicates the 12 LSBs of the AID) based on the Special User Info Field Present subfield. For example, when indicating an RA-RU for an unassociated STA, if a trigger frame is received by a STA that is not associated with the AP that sent the trigger frame, the STA can operate based on the trigger frame. Furthermore, spatial reuse can be performed based on a trigger frame or a TB PPDU from a BSS to which the STA is not associated.

[0426] Furthermore, when a trigger frame includes a Special User Info field, the Special User Info field may be located at the front of the User Info fields, or may be located immediately after the Common Info field, so that a STA receiving the trigger frame can easily parse the Special User Info field.

[0427] According to an embodiment of the present invention, the format of a PPDU in response to a trigger frame may be determined based on whether the trigger frame includes a Special User Info field. For example, if the trigger frame includes a Special User Info field, the format of the PPDU in response to the trigger frame may be an EHT TB PPDU. Alternatively, if the trigger frame does not include a Special User Info field, the format of the PPDU in response to the trigger frame may be an HE TB PPDU. As described above, a Special User Info Field Present subfield may be present, which is signaling indicating whether the trigger frame includes a Special User Info field. Therefore, it can be said that the format of a PPDU in response to a trigger frame can be determined based on the Special User Info Field Present subfield. For example, if the Special User Info Field Present subfield is set to 0, the format of the PPDU in response to the trigger frame may be an EHT TB PPDU. Alternatively, if the Special User Info Field Present subfield is set to 1, the format of the PPDU in response to the trigger frame may be an HE TB PPDU.

[0428] Furthermore, when a trigger frame includes a Special User Info field, the User Info field included in the trigger frame may be an EHT variant User Info field. Furthermore, when a trigger frame does not include a Special User Info field, the trigger frame does not need to include an EHT variant User Info field. When a trigger frame does not include a Special User Info field, the trigger frame may include only an HE variant User Info field.

[0429] The RU indication method may differ when the User Info field is the EHT variant and when it is the HE variant. For example, the interpretation method of the User Info field may differ depending on whether the RU Allocation subfield included in the User Info field is the EHT variant or the HE variant. For example, the RU Allocation subfield included in the EHT variant User Info field may be encoded to indicate an RU supported by the EHT standard. Also, the RU Allocation subfield included in the HE variant User Info field may be encoded to indicate an RU supported by the HE standard.

[0430] Furthermore, when interpreting an RU indicated based on the EHT variant User Info field, it is necessary to refer to two or more subfields. The two or more subfields may include an RU Allocation subfield and a PS160 subfield. The RU Allocation subfield may be located immediately after the AID12 subfield as shown in FIG. 16. The RU Allocation subfield may be 8 bits. The PS160 subfield may indicate which subchannel the RU indicated by the RU Allocation subfield is located on. Alternatively, the PS160 subfield may indicate which subchannel the RU indicated by the User Info field is located on. In this case, the unit for indicating which subchannel may be 160 MHz subchannels. The PS160 subfield may indicate whether the indicated RU is located on a primary 160 MHz channel or a secondary 160 MHz channel. The PS160 subfield may be located immediately before the Trigger Dependent User Info field. The PS160 subfield may be bit B39 of the User Info field. The PS160 subfield may be 1 bit.

[0431] Furthermore, when interpreting an RU indicated based on the HE variant User Info field, it may be based on one subfield. The one subfield may be the RU Allocation subfield. That is, the location of the RU indicated by the HE variant User Info field can be determined based only on the RU Allocation subfield included in the HE variant User Info field.

[0432] Referring to FIG. 29, the trigger frame may include a Special User Info field. Whether the User Info field is a Special User Info field may be determined based on the AID12 subfield included in the User Info field. For example, if the AID12 subfield included in the User Info field has a pre-set value, the User Info field may be a Special User Info field. Referring to FIG. 29, the pre-set value may be 2007. Also, referring to FIG. 29, the Special User Info field may be located immediately after the Common Info field, at the forefront of the User Info fields. Also, a Special User Info Field Present subfield may be present, which is signaling indicating whether the trigger frame includes a Special User Info field. Referring to FIG. 29, the Special User Info Field Present subfield may be included in the Common Info field. If the Special User Info Field Present subfield is set to 0, the trigger frame may include a Special User Info field. As shown in FIG. 29, when the trigger frame includes a Special User Info field, the response PPDU format thereto may be an EHT TB PPDU.

[0433] According to an additional embodiment, the format of a PPDU in response to the trigger frame can be determined based on whether the trigger frame includes a Special User Info field and the subfield indicating the TB PPDU format. In the present invention, the subfield indicating the TB PPDU format can be referred to as the HE / EHT P160 subfield. According to a more specific embodiment, the HE / EHT P160 subfield may indicate the TB PPDU format for a previously established channel. For example, the HE / EHT P160 subfield may indicate the TB PPDU format for a primary 160 MHz channel (P160 channel). For example, a value of the HE / EHT P160 subfield may indicate a response with an HE TB PPDU. A value of the HE / EHT P160 subfield may indicate a response with an EHT TB PPDU. The HE / EHT P160 subfield may be 1 bit.

[0434] 29, the HE / EHT P160 subfield may be included in the Common Info field. More specifically, the HE / EHT P160 subfield may be included in the bit B55 position of the Common Info field.

[0435] Therefore, the following operations can be performed when indicating and determining the TB PPDU format based on the Special User Info field and the HE / EHT P160 subfield: If the HE / EHT P160 subfield indicates an EHT TB PPDU, a response can be made with the EHT TB PPDU when responding to a trigger frame. That is, if the HE / EHT P160 subfield indicates an EHT TB PPDU, a response can be made with the EHT TB PPDU when responding to a trigger frame regardless of the assigned RU location. Also, if the HE / EHT P160 subfield indicates an EHT TB PPDU, the Special User Info field may always be included. That is, the Special User Info Field Present subfield can also indicate that the Special User Info field is included.

[0436] If the HE / EHT P160 subfield indicates an HE TB PPDU, the TB PPDU format can be indicated and determined based on the allocated RU location when responding to the trigger frame. If the HE / EHT P160 subfield indicates an HE TB PPDU and an allocated RU is included in the already configured channel (e.g., P160 channel) indicated by the HE / EHT P160 subfield, the response can be made with an HE TB PPDU. Also, if the HE / EHT P160 subfield indicates an HE TB PPDU and an allocated RU is not included in the already configured channel (e.g., P160 channel) indicated by the HE / EHT P160 subfield (e.g., an RU allocated to a secondary 160 MHz channel (S160 channel)), the response can be made with an EHT TB PPDU. Whether an allocated RU is included in the already configured channel can be determined based on the RU Allocation subfield and the PS160 subfield. More specifically, if the already-configured channel is a P160 channel, whether the already-configured channel includes an assigned RU may be determined based on the PS160 subfield.

[0437] Furthermore, indicating and determining the TB PPDU format based on the HE / EHT P160 subfield and the assigned RU location may be limited to cases where the trigger frame includes a Special User Info field. If the trigger frame includes a Special User Info field, the trigger frame may include an HE / EHT P160 subfield and a PS160 subfield. If the trigger frame does not include a Special User Info field, the trigger frame can always be responded to using an HE TB PPDU. Also, as described above, whether or not the Special User Info field is included may depend on the Special User Info Field Present subfield. Therefore, the descriptions of whether the trigger frame includes or does not include the Special User Info field may refer to whether or not the Special User Info Field Present subfield is set to include or not include the Special User Info field, respectively.

[0438] In the present invention, the description of instructing or determining whether to use the EHT TB PPDU when responding to a trigger frame may be replaced with an invention of instructing or determining whether to use the EHT TB PPDU or the NEXT TB PPDU. Furthermore, whether to use the EHT TB PPDU or the NEXT TB PPDU may be determined based on the Format Identifier subfield. That is, the TB PPDU format indicated by the Format Identifier subfield can be used. For example, if the Format Identifier subfield indicates EHT, the EHT TB PPDU can be used.

[0439] The Special User Info field may include an AID12 subfield and information required when responding to a trigger frame. The information required when responding to a trigger frame may include information included in the preamble of a PPDU responding to the trigger frame. For example, the information required when responding to a trigger frame may include information included in the U-SIG field of a PPDU responding to the trigger frame. FIG. 29 may include an example of information included in the U-SIG field. Referring to FIG. 29, the Special User Info field may include AID12, PHY Version ID, UL Bandwidth Extension, Spatial Reuse 1, Spatial Reuse 2, U-SIG Disregard And Validate, Reserved, and Trigger Dependent User Info fields. The mentioned fields may be present in the mentioned order. The mentioned fields may have the following number of bits: 12, 3, 2, 4, 4, 12, 3, or variable, respectively. The PHY Version ID field may be the Format Identifier subfield, the PHY version identifier subfield, or the PHY version field described above. A STA responding to a trigger frame can set the U-SIG field included in the responding PPDU based on the Special User Info field included in the trigger frame. For example, the subfield values ​​included in the Special User Info field can be copied to the subfields included in the responding U-SIG field. The subfields copied to the subfields included in the U-SIG field can be the PHY Version ID, Spatial Reuse 1, Spatial Reuse 2, and U-SIG Disregard And Validate subfields.

[0440] Alternatively, the subfield included in the U-SIG field of the responding PPDU can be set based on the subfield value included in the Special User Info field. The subfield for setting the U-SIG field based on the subfield included in the Special User Info field may be the UL Bandwidth Extension subfield. For example, the bandwidth (BW) subfield included in the U-SIG field of the responding PPDU can be set based on the UL Bandwidth Extension subfield included in the Special User Info field and the UL BW subfield included in the Common Info field (see FIG. 16).

[0441] Furthermore, the presence and length of the Trigger Dependent User Info field included in the Special User Info field may be based on the type of the trigger frame. That is, the presence and length of the Trigger Dependent User Info field included in the Special User Info field may be based on which variant the trigger frame is. The type of the trigger frame may be indicated and determined by the Trigger Type subfield included in the Common Info field (see FIG. 16).

[0442] FIG. 30 is a flowchart illustrating an example of the operation of a terminal according to an embodiment of the present invention.

[0443] First, a terminal that is a non-AP STA can receive a frame that triggers the transmission of a physical layer protocol data unit (PPDU) from an AP (or an AP STA) (S30010).

[0444] In this case, the frame that triggers the PPDU may be a trigger frame or a frame containing a TRS.

[0445] The non-AP STA can then generate a PPDU to transmit as a response to the frame, and can set the duration of the PE field included in the PPDU.

[0446] The PE field is a field for providing additional processing time for the PPDU and does not require additional decoding. In this case, the PE field may be located at the end of the PPDU and transmitted at the average power of the data field.

[0447] The duration of the PE field may be set by the method described above with reference to Figures 19 to 29. For example, the duration of the PE field may be set according to the format of the PPDU indicated by the frame, and the maximum value of the duration of the PE field may be determined differently depending on the format of the PPDU.

[0448] Specifically, the duration of the PE field of the TB PPDU may be set to a value indicated by the PE Duration field indicated by the TRS control field, or may be set to a value indicated by the Default PE Duration subfield included in the Action element. Alternatively, when the TB PPDU is triggered only by the trigger frame, the duration of the PE field of the TB PPDU may be set according to specific conditions (MCS method, RU size, number of spatial streams used, and / or indicated PPDU format (e.g., whether EHT TB PPDU or HE TB PPDU is indicated)).

[0449] For example, a PE field duration of 20 us may be permitted only when the TB PPDU satisfies the above-mentioned specific conditions (e.g., when it is designated as an EHT TB PPDU, when eight or more spatial streams are used, when the size of at least one RU is greater than 2x996, when the bandwidth over which the EHT PPDU (or EHT MU PPDU, etc.) is transmitted is 320 MHz, or when the PPDU is modulated with 4096-QAM, etc.).

[0450] If the transmission of a PPDU is instructed by the TRS, the duration of the PE field included in the PPDU may be set to a value indicated by a default PE duration subfield included in an operation element (e.g., an HE operation element or an EHT operation element) or a value indicated by a PE duration subfield included in the TRS control field.

[0451] If a TRS and a trigger frame are included in one PPDU and both indicate the transmission of the PPDU, and if the maximum value of the duration of the PE field when the PPDU is indicated by the trigger frame is the same as the maximum value of the duration of the PE field when indicated by the TRS, it may be set to the value indicated by the default PE duration subfield or the value indicated by the PE duration subfield included in the TRS.

[0452] However, when a TRS and a trigger frame are included in a single PPDU and both indicate transmission of the PPDU, the duration of the PE field when the PPDU is indicated by the trigger frame and the maximum value of the PE field duration indicated by the default PE duration subfield when indicated by the TRS may not be the same. For example, if the TB PPDU indicated by the trigger frame and / or TRS meets a specific condition, the maximum value of the PE field duration may be a first maximum value (e.g., 20 us), and the maximum value of the PE field duration indicated by the default PE subfield included in the action element may be a second maximum value (e.g., 16 us). In this case, the duration of the PE field may be set to the value indicated by the default PE subfield or the value indicated by the PE subfield included in the TRS.

[0453] In this case, the PE Duration subfield can indicate that the maximum duration of the PE field is allowed to be 20 us, or can indicate that the value of the Default PE Duration subfield included in the Action element should be set as the duration of the PE field.

[0454] In other words, according to an embodiment of the present invention, the duration of the PE field may be determined based on the PPDU format used in response to a TRS. According to an embodiment, when responding to a TRS with an HE PPDU, the duration of the PE field may be the HE default PE duration. Also, when responding to a TRS with an EHT PPDU, the duration of the PE field may be a value indicated by the EHT default PE duration. For example, the HE PPDU may be an HE TB PPDU. Or the HE PPDU may be an HE SU PPDU. Or the EHT PPDU may be an EHT TB PPDU. Or the EHT PPDU may be an EHT MU PPDU. Also, the HE default PE duration may be the default PE duration described in FIG. 20 and FIG. 21. For example, the HE default PE duration may be a value indicated by an HE action element. More specifically, the HE default PE duration may be a value indicated in a default PE duration subfield included in an HE action element.

[0455] Also, the EHT default PE duration may be a value indicated by an EHT operation element. More specifically, the EHT default PE duration may be a value indicated by an EHT default PE duration subfield included in the EHT operation element.

[0456] According to one embodiment, the EHT Default PE Duration subfield may indicate whether the duration of the PE field is 20 us, in which case the EHT Default PE Duration subfield may be 1 bit.

[0457] According to another embodiment, the EHT default PE duration subfield can indicate whether the duration of the PE field is the same as the HE default PE duration. In this case, the EHT default PE duration subfield can be 1 bit. For example, if the EHT default PE duration subfield indicates that the duration of the PE field is the same as the HE default PE duration, the EHT default PE duration can be the default PE duration indicated by the HE operation element. Also, if the EHT default PE duration subfield indicates that the duration of the PE field is not the same as the HE default PE duration, the EHT default PE duration can be 20 us.

[0458] According to another embodiment, the EHT Default PE Duration subfield can indicate the duration of the PE field as 0, 4, 8, 12, 16, or 20 us. In this case, the EHT Default PE Duration subfield can be 3 bits. According to yet another embodiment, the EHT Default PE Duration can be 20 us.

[0459] Thereafter, the non-AP STA can transmit a PPDU including a packet extension (PE) field for providing processing time for the PPDU in response to the frame (S30020).

[0460] In this case, if the format of the PPDU indicated by the frame is an HE (High Efficiency) PPDU, the maximum value of the duration for the PE field is a first value, and if the format of the PPDU indicated by the frame is an EHT (Extremely High Throughput) PPDU, the maximum value of the duration for the PE field is a second value.

[0461] The first value is "16 us" and the second value is "20 us".

[0462] A non-AP STA may receive an operation element from the AP. The operation element includes a default PE duration subfield indicating the duration for the PE field, and when a value of a control identifier (ID) subfield included in the frame indicates triggered response scheduling (TRS) for triggering transmission of the PPDU, if the format of the PPDU is indicated as an EHT PPDU by the frame and the maximum value of the duration indicated by the default PE duration subfield is different from the maximum value of the duration when the format of the PPDU is indicated as the EHT PPDU by the frame, the maximum value for the duration of the PE field is determined by the default PE duration subfield.

[0463] When the value of a control identifier subfield included in the frame indicates TRS (Triggered response scheduling) for triggering the transmission of a PPDU to another STA, the values ​​of each of the multiple subfields included in the frame used to calculate the duration of the PE field are set so that the duration of the PE field calculated using the multiple subfields is identical to the duration of the PE field of the PPDU to the other STA.

[0464] The action element includes an EHT default PE duration subfield that indicates whether the maximum duration for the PE field of the EHT PPDU is the same as the maximum duration for the PE field of the HE PPDU.

[0465] If the EHT Default PE Duration subfield indicates that the maximum value of the duration for the PE field of the EHT PPDU is not the same as the maximum value of the duration for the PE field of the HE PPDU, the duration for the PE field indicated by the EHT Default PE Duration subfield is "20us".

[0466] If the PPDU is modulated with 4096-QAM, or the number of spatial streams is 8 or more, or the channel bandwidth is 320 MHz, and the size of the resource unit (RU) allocated for transmitting the PPDU is 2x996 or more, the maximum value of the duration of the PE field is '20us'.

[0467] 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 spirit or essential features of the present invention. Therefore, the above-described embodiments should be understood as illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed form, and similarly, each component described as a distributed type may be implemented in a combined form.

[0468] The scope of the present invention is indicated by the claims set forth below rather than by the above detailed description, and any modifications or variations derived from the meaning and scope of the claims and their equivalent concepts should be construed as being within the scope of the present invention.

Claims

1. A terminal of a wireless communication system, communication module; a processor for controlling the communication module; The processor: Receive a frame that triggers the transmission of a physical layer protocol data unit (PPDU) from an access point (AP); In response to the frame, a PPDU including a packet extension (PE) field for providing processing time for the PPDU is transmitted; The frame indicates a format for the PPDU to be sent in response to the frame; The maximum duration for the PE field varies depending on the format of the PPDU indicated by the frame.

2. When the format of the PPDU indicated by the frame is a High Efficiency (HE) PPDU, the maximum value of the duration for the PE field is a first value; The terminal of claim 1 , wherein when the format of the PPDU indicated by the frame is an Extremely High Throughput (EHT) PPDU, the maximum value of the duration for the PE field is a second value.

3. The first value is "16 us", The terminal of claim 2 , wherein the second value is “20 us”.

4. The processor: receiving an operation element from the AP; The operation element includes a Default PE duration subfield that indicates the duration for the PE field; 2. The terminal of claim 1, wherein, when a value of a control identifier (ID) subfield included in the frame indicates a TRS (Triggered response scheduling) for triggering transmission of the PPDU, the format of the PPDU is indicated as an EHT PPDU by the frame, and when the maximum value of the duration indicated by the default PE duration subfield is different from the maximum value of the duration when the format of the PPDU is indicated as the EHT PPDU by the frame, the maximum value for the duration of the PE field is determined by the default PE duration subfield.

5. If the value of the control identifier subfield included in the frame indicates a TRS (Triggered response scheduling) for triggering the transmission of a PPDU to another STA, The terminal of claim 1, wherein the values ​​of each of a plurality of subfields included in the frame used to calculate the duration of the PE field are set so that the duration of the PE field calculated using the plurality of subfields is the same as the duration of the PE field of the PPDU for the other STA.

6. The processor: receiving an action element from the AP; 2. The terminal of claim 1, wherein the action element includes an EHT Default PE Duration subfield indicating whether a maximum duration value for a PE field of an EHT PPDU is the same as a maximum duration value for a PE field of an HE PPDU.

7. 7. The terminal of claim 6, wherein when the EHT Default PE Duration subfield indicates that the maximum value of the duration for the PE field of the EHT PPDU is not the same as the maximum value of the duration for the PE field of the HE PPDU, the duration for the PE field indicated by the EHT Default PE Duration subfield is “20 us”.

8. 2. The terminal of claim 1, wherein the maximum value of the duration of the PE field is '20us' when the PPDU is modulated with 4096-QAM, the number of spatial streams is 8 or more, the channel bandwidth is 320 MHz, and the size of a resource unit (RU) allocated for transmission of the PPDU is 2x996 or more.

9. A method for a terminal to transmit a frame in a wireless communication system, comprising: receiving a frame from an access point (AP) that triggers the transmission of a physical layer protocol data unit (PPDU); and transmitting a PPDU in response to the frame, the PPDU including a packet extension (PE) field for providing a processing time for the PPDU; the frame indicating a format for the PPDU to be sent in response to the frame; The maximum duration for the PE field varies depending on the format of the PPDU indicated by the frame.

10. When the format of the PPDU indicated by the frame is a High Efficiency (HE) PPDU, the maximum value of the duration for the PE field is a first value; 10. The method of claim 9, wherein when the format of the PPDU indicated by the frame is an Extremely High Throughput (EHT) PPDU, the maximum value of the duration for the PE field is a second value.

11. The first value is "16 us", The method of claim 10 , wherein the second value is “20 us”.

12. receiving an operation element from the AP; The operation element includes a Default PE duration subfield that indicates the duration for the PE field; 10. The method of claim 9, wherein, when a value of a control identifier (ID) subfield included in the frame indicates a TRS (Triggered response scheduling) for triggering transmission of the PPDU, the format of the PPDU is indicated as an EHT PPDU by the frame, and when the maximum value of the duration indicated by the default PE duration subfield is different from the maximum value of the duration when the format of the PPDU is indicated as the EHT PPDU by the frame, the maximum value for the duration of the PE field is determined by the default PE duration subfield.

13. 10. The method of claim 9, wherein when a value of a control identifier subfield included in the frame indicates a TRS (Triggered response scheduling) for triggering transmission of a PPDU to another STA, the values ​​of each of a plurality of subfields included in the frame used to calculate the duration of the PE field are set so that the duration of the PE field calculated using the plurality of subfields is the same as the duration of the PE field of the PPDU for the other STA.

14. receiving an operational element from the AP; 10. The method of claim 9, wherein the action element includes an EHT Default PE Duration subfield indicating whether a maximum duration value for the PE field of an EHT PPDU is the same as a maximum duration value for the PE field of an HE PPDU.

15. 15. The method of claim 14, wherein if the EHT Default PE Duration subfield indicates that the maximum value of the duration for the PE field of the EHT PPDU is not identical to the maximum value of the duration for the PE field of the HE PPDU, then the duration for the PE field indicated by the EHT Default PE Duration subfield is “20 us”.

16. 10. The method of claim 9, wherein the maximum value of the duration of the PE field is '20 us' when the PPDU is modulated with 4096-QAM, the number of spatial streams is 8 or more, the channel bandwidth is 320 MHz, and the size of a resource unit (RU) allocated for transmission of the PPDU is 2x996 or more.

Images