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

Abstract

To disclose a method for transmitting a TB PPDU in a wireless communication system.SOLUTION: A non-AP STA may receive a frame that triggers transmission of a PPDU (physical layer protocol data unit) from an AP (access point), and transmit a PPDU including a PE (packet extension) field for providing a processing time for the PPDU in response to the frame. In this case, the frame indicates the format of the PPDU to be transmitted in response to the frame, and the maximum values of the duration for the PE field may differ depending on 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 a processing time of a radio frame. [Background technology]

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

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

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

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

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

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

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

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

[0010] 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 wireless frame a field for reserving processing time for a receiving device when transmitting and receiving a wireless 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 a field duration for ensuring processing time of a receiving device in a different manner depending on a specific condition.

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

[0016] A terminal of a wireless communication system includes a communication module; and a processor that controls the communication module, the processor 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 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 differing 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] In addition, 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 Triggered Response Scheduling (TRS) for triggering transmission of the PPDU, when 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 transmission of a PPDU to another STA, the values ​​of each of a plurality of subfields included in the frame used for calculating the duration of the PE field are set so that the duration of the PE field calculated by the plurality of 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] In addition, 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 a resource unit (RU) allocated for transmitting the PPDU is 2×996 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) to trigger transmission of a physical layer protocol data unit (PPDU); and transmitting a PPDU including a packet extension (PE) field for providing a processing time for the PPDU in response to the frame, 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 differing depending on the format of the PPDU indicated by the frame. Effect 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 description of the drawings]

[0030] [Figure 1] FIG. 1 is a diagram showing a wireless LAN system according to an embodiment of the present invention. [Diagram 2] FIG. 11 is a diagram showing a wireless LAN system according to another embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram showing a configuration of a station according to an embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing the configuration of an access point according to an embodiment of the present invention. [Diagram 5] 1 is a diagram illustrating a process in which a STA sets up a link with an AP. [Figure 6] FIG. 1 is a diagram illustrating a CSMA (Carrier Sense Multiple Access) / CA (Collision Avoidance) method used in wireless LAN communication. [Figure 7] 1 shows examples of various standard generation PPDU (PLCP Protocol Data Unit) formats. [Figure 8] 1 illustrates an example of various Extremely High Throughput (EHT) Physical Protocol Data Unit (PPDU) formats and a method for indicating the same according to an embodiment of the present invention. [Figure 9] FIG. 1 illustrates a multi-link device according to an embodiment of the present invention. [Figure 10] A diagram showing an example of a TID-to-link mapping method in one embodiment of the present invention. [Figure 11] A diagram showing an example of a multi-link NAV setting operation according to one embodiment of the present invention. [Figure 12] A diagram showing yet another example of a multi-link NAV setting operation according to one embodiment of the present invention. [Figure 13] FIG. 2 is a diagram showing an example of BSS classification and operations based thereon according to an embodiment of the present invention. [Figure 14]1 shows a wireless LAN function according to an embodiment of the present invention. [Figure 15] 1 illustrates an uplink (UL) multi-user (MU) operation according to one embodiment of the present invention. [Figure 16] 1 shows a trigger frame format according to one embodiment of the present invention. [Figure 17] 1 illustrates a method for indicating a trigger-based PPDU format according to one embodiment of the present invention. [Figure 18] 1 illustrates an example of UL MU operation according to one embodiment of the present invention. [Figure 19] 1 illustrates an example of a packet extension (PE) field for providing processing time according to an embodiment of the present invention. [Figure 20] 1 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] 1 illustrates an example of a method for setting the duration of a PE field according to an embodiment of the present invention. [Figure 22] 13 illustrates yet another example of a method for configuring UL MU operation and duration of a PE field according to an embodiment of the present invention. [Figure 23] 13 illustrates yet another example of a method for configuring UL MU operation and duration of a PE field according to an embodiment of the present invention. [Figure 24] 13 illustrates yet another example of a method for configuring UL MU operation and duration of a PE field according to an embodiment of the present invention. [Diagram 25] 13 shows an example of a method for setting a CS Required subfield according to one embodiment of the present invention. [Figure 26] 13 illustrates an example of a CS Required subfield configuration and a UL MU operation according to an embodiment of the present invention. [Figure 27] 13 illustrates yet another example of the configuration of a CS Required subfield and a UL MU operation according to an embodiment of the present invention. [Figure 28] 1 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] 1 illustrates an example of a method for indicating a format of a TB PPDU according to an embodiment of the present invention. [Diagram 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 PREFERRED EMBODIMENTS

[0031] The terms used in this specification are selected as general terms that are currently widely used as much as possible in consideration of the functions of the present invention, but this may vary depending on the intentions, customs, or the emergence of new technologies of the engineers in the relevant technical field. In addition, in certain cases, the applicant may arbitrarily select terms, and in such cases, the meanings of the terms will be described in the description of the relevant invention. Therefore, it is clear that the terms used in this specification should be interpreted not simply as terms, but based on the substantial meanings of the terms and the contents of this specification as a whole.

[0032] Throughout the specification, when a certain component is "connected" to another component, this includes not only when it is "directly connected" to another component, but also when it is "electrically connected" with another component therebetween. Furthermore, when a certain component "includes" a certain component, this means that it may further include the other component, not excluding the other component, unless otherwise specified. In addition, limitations such as "greater than" or "less than" based on a specific critical value may be appropriately replaced with "more than" or "less than", respectively, depending on the embodiment. Hereinafter, in the present invention, the terms "field" and "subfield" may be used interchangeably.

[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 (BSS), which are a set of devices that can successfully synchronize and communicate with each other. Generally, BSSs are classified into infrastructure BSSs and independent BSSs (IBSSs), and Figure 1 shows an infrastructure BSS.

[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 which are stations providing a distribution service, and a distribution system DS which connects multiple access points AP-1 and AP-2.

[0036] A station (STA) is any device including a medium access control (MAC) and a physical layer interface for a wireless medium according to the IEEE 802.11 standard, and in a broad sense includes not only non-AP stations but also APs. In this specification, the term "terminal" refers to either a non-AP or an AP, or both. A station for wireless communication includes a processor and a communication unit, and further includes a user interface unit and a display unit, etc., depending on the embodiment. The processor generates frames to be transmitted through a wireless network, processes frames received through the wireless network, and performs various other processes for controlling the station. The communication unit is functionally connected to the processor and transmits and receives frames through the wireless network for the station. In the present invention, the term "terminal" is used to include a user equipment (UE).

[0037] An access point (AP) is an entity that provides a connection to a distribution system DS via a wireless medium for a station associated therewith. In an infrastructure BSS, communication between non-AP stations is generally performed via the AP, but when a direct link is set up, direct communication is possible between non-AP stations. Meanwhile, in the present invention, AP is used as a concept including a personal BSS coordination point (PCP), but in a broad sense, AP includes all concepts such as a central controller, a base station (BS), a node B, a base transceiver system (BTS), or a site controller. In the present invention, AP is also referred to as a base wireless communication terminal, but in a broad sense, the base wireless communication terminal is used as a term including an AP, a base station, an eNodeB (eNB), and a transmission point TP. In addition, the base wireless communication terminal includes various types of wireless communication terminals that allocate communication medium resources and perform scheduling in communication with a plurality of wireless communication terminals.

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

[0039] 2 is a diagram showing an independent BSS, which is a wireless LAN system according to another embodiment of the present invention, in which the same or corresponding parts in the embodiment of FIG. 2 are described in the same manner as in the embodiment of FIG.

[0040] BSS3 shown in Figure 2 is an independent BSS and does not include an AP, so all stations (STA6, STA7) are not connected to an AP. An independent BSS is not allowed to connect to a distribution system and forms a self-contained network. In an independent BSS, each station (STA6, STA7) is directly connected to each other.

[0041] 3 is a block diagram showing a configuration of a station 100 according to an embodiment of the present invention. As shown in the figure, the station 100 according to the embodiment of the present invention includes a processor 110, a communication unit 120, a user interface unit 140, a display unit 150, and a memory 160.

[0042] First, the communication unit 120 transmits and receives wireless signals such as wireless LAN packets, and may be built into or externally provided in the station 100. According to an embodiment, the communication unit 120 may include at least one communication module using different frequency bands. For example, the communication unit 120 may include communication modules of different frequency bands such as 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz. According to an embodiment, the station 100 may include a communication module using a frequency band of 7.125 GHz or more and a communication module using a frequency band of 7.125 GHz or less. Each communication module may perform wireless communication with an AP or an external station based on the wireless LAN standard of the frequency band supported by the communication module. The communication unit 120 may operate only one communication module at a time or operate multiple communication modules simultaneously according to the performance and requirements of the station 100. When the station 100 includes multiple communication modules, each communication module may be provided in an independent form, or multiple modules may be integrated into one chip. In an embodiment of the present invention, the communication unit 120 may represent a radio frequency (RF) communication module that processes RF signals.

[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 a command from the processor 110 using various output means.

[0044] Then, the display unit 150 outputs an image on a display screen. The display unit 150 outputs various display objects such as a user interface based on the contents performed by the processor 110 or a control command of the processor 110. The memory 160 also stores control programs used by the station 100 and various data associated therewith. Such control programs include connection programs required for the station 100 to connect to an AP or an external station.

[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 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 on the priority conditions of the station 100 included in the communication setup message and requests a connection to the AP based on the information on the priority conditions of the station 100. The processor 110 of the present invention may refer to a main control unit of the station 100, or may refer to a control unit for individually controlling some components of the station 100, for example, the communication unit 120, depending on the embodiment. That is, the processor 110 may be a modem that modulates and demodulates a wireless signal transmitted and received from the communication unit 120, or a modulator and / or demodulator. The processor 110 controls various operations of transmitting and receiving wireless signals of the station 100 according to an embodiment of the present invention. A detailed embodiment of the present invention will be described later.

[0046] The station 100 shown in FIG. 3 is a block diagram according to an embodiment of the present invention, and the separate blocks are used to logically distinguish the elements of the device. Thus, the above-mentioned device elements may be mounted on one chip or multiple chips depending on the design of the device. For example, the processor 110 and the communication unit 120 may be integrated and embodied on one chip, or may be embodied on separate chips. In addition, in an embodiment of the present invention, some components of the station 100, such as the user interface unit 140 and the display unit 150, may be selectively provided in the station 100.

[0047] 4 is a block diagram showing a configuration of an AP 200 according to an embodiment of the present invention. As shown in the figure, the AP 200 according to the embodiment of the present invention includes a processor 210, a communication unit 220, and a memory 260. In FIG. 4, a duplicated description of parts of the configuration of the AP 200 that are the same as or correspond to the configuration of the station 100 in FIG. 3 will be omitted.

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

[0049] Next, the memory 260 stores control programs used in the AP 200 and various data associated therewith. Such control programs include a connection program for managing station connections. Also, the processor 210 controls each unit of the AP 200 and controls transmission and reception of data between the units. According to an embodiment of the present invention, the processor 210 executes a program for connection with a station stored in the memory 260 and transmits a communication setting message to one or more stations. At this time, the communication setting message includes information regarding connection priority conditions of each station. Also, the processor 210 performs connection setting in response to a connection request of a station. According to an embodiment, the processor 210 is a modem or a modulation / demodulation unit that modulates and demodulates wireless signals transmitted and received from the communication unit 220. The processor 210 controls various operations of transmitting and receiving wireless signals of the AP 200 according to an embodiment of the present invention. A detailed embodiment thereof will be described later.

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

[0051] 5, the link between the STA 100 and the AP 200 is set up through three steps: scanning, authentication, and association. First, the scanning step is a step in which the STA 100 acquires connection information of the BSS operated by the AP 200. There are two methods for performing scanning: a passive scanning method in which the AP 200 acquires information only by using a beacon message S101 periodically transmitted by the AP, and an active scanning method in which the STA 100 transmits a probe request to the AP S103, receives a probe response from the AP S105, and acquires connection information.

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

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

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

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

[0057] If a specific terminal succeeds in accessing the channel, the terminal transmits data through the channel. However, if the terminal attempting access collides with another terminal, the colliding terminals are assigned new random numbers and perform a backoff procedure again. According to one embodiment, the random numbers newly assigned to each terminal are determined within a range (2*CW) twice the range of the random numbers previously assigned to the terminal (contention window, CW). Meanwhile, each terminal attempts access by performing a backoff procedure again in the next contention window period, and at this time, each terminal performs the backoff procedure from the slot time remaining in the previous contention window period. In this manner, each terminal performing wireless LAN communication can avoid collision with each other on a specific channel.

[0058] Hereinafter, in the present invention, a terminal can be called a non-AP STA, an AP STA, an AP, an STA, a receiving device, or a transmitting device, and the present invention is not limited thereto. Also, in the present invention, an AP STA can be called an AP.

[0059] <Examples of various PPDU formats>

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

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

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

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

[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 speeds of 6 / 9 / 12 / 18 / 24 / 36 / 48 / 54 Mbps, which is a combination of a modulation method such as BPSK / QPSK / 16-QAM / 64-QAM and a code rate such as 1 / 2, 2 / 3, or 3 / 4. The total length of the PPDU can be indicated by combining the information in the L_RATE field and the L_LENGTH field. In the non-legacy PPDU format, the L_RATE field is set to the minimum speed of 6 Mbps.

[0066] The unit of the L_LENGTH field is a byte, and a total of 12 bits are assigned to signal up to 4095. In combination with the L_RATE field, it can indicate the length of the corresponding PPDU. In this case, legacy terminals and non-legacy terminals can interpret the L_LENGTH field in different ways.

[0067] First, the method in which a legacy or non-legacy terminal interprets the length of the corresponding PPDU using the L_LENGTH field is as follows. When the value of the L_RATE field is set to indicate 6 Mbps, 3 bytes (i.e., 24 bits) may be transmitted during 4 us, which is one symbol duration of 64 FFT. Therefore, the number of 64 FFT reference symbols after the L-SIG is obtained by adding 3 bytes corresponding to the SVC field and the Tail field to the L_LENGTH field value and dividing it by 3 bytes, which is the transmission amount of one symbol. The length of the corresponding PPDU, i.e., the reception time (RXTIME), is obtained by multiplying the number of symbols obtained by 4 us, which is one symbol duration, and then adding 20 us for transmitting the L-STF, L-LTF, and L-SIG. This can be expressed as the following Equation 1.

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

[0075] The VI bit will maintain the current bit configuration, and even if a subsequent generation PPDU is defined, a current 11be terminal can obtain information about the PPDU from the VI field of the PPDU. To this end, the VI field is composed of PHY version, UL / DL, BSS color, TXOP, and Reserved fields. The PHY version field is 3 bits, and serves to sequentially distinguish 11be and subsequent generation WLAN standards by version. 11be has a value of 000b. The UL / DL field distinguishes whether the corresponding PPDU is an uplink / downlink PPDU. The BSS color means a BSS-specific identifier defined in 11ax, and has a value of 6 bits or more. The TXOP means a transmit opportunity duration that was transmitted in the MAC header, but by adding it to the PHY header, the length of the TXOP containing the corresponding PPDU can be inferred without decoding the MPDU, and has a value of 7 bits or more.

[0076] The VD field may be composed of fields commonly used in any PPDU format, such as PPDU format and BW, which are signaling information useful only for PPDUs of the 11be version, and fields defined differently for each PPDU format. The PPDU format is a division factor that distinguishes EHT SU (Single User), EHT MU (Multiple User), EHT TB (Trigger-based), EHT ER (Extended Range) PPDU, etc. The BW field mainly signals five basic PPDU BW options of 20, 40, 80, 160 (80+80), and 320 (160+160) MHz (BWs that can be expressed in the form of a power of 20*2 can be called basic BWs), and various remaining PPDU BWs formed by preamble puncturing. After being signaled at 320 MHz, some 80 MHz may be signaled in a punctured form. Also, the punctured and modified channel shape may be directly signaled in the BW field, or may be signaled using both the BW field and a field that appears after the BW field (e.g., a field in the EHT-SIG field). If the BW field is 3 bits, a total of 8 BW signalings are possible, so a maximum of 3 puncturing modes can be signaled. If the BW field is 4 bits, a total of 16 BW signalings are possible, so a maximum of 11 puncturing modes can be signaled.

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

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

[0079] When a part of the EHT-SIG field of the SU PPDU is compressed, the information included in the compressed field may be signaled together in an uncompressed field (e.g., a common field, etc.). In the case of the MU PPDU, since it is a PPDU format for simultaneous reception by multiple users, the EHT-SIG field must be transmitted after the U-SIG field, and the amount of information signaled may be variable. That is, since multiple MU PPDUs are transmitted to multiple STAs, each STA must recognize the location of the RU to which the MU PPDU is transmitted, the STA to which each RU is assigned, and whether the transmitted MU PPDU was transmitted to itself. Therefore, the AP must transmit the above information in the EHT-SIG field. To this end, the U-SIG field signals information for efficiently transmitting the EHT-SIG field, which may be the number of symbols of the EHT-SIG field and / or MCS, which is a modulation method. The EHT-SIG field may include the size and location information of the RU assigned to each user.

[0080] In the case of a SU PPDU, a STA may be assigned multiple RUs, and the multiple RUs may be contiguous or discontinuous. If the RUs assigned to the STA are not contiguous, the STA can receive the SU PPDU efficiently only by recognizing the RUs punctured in between. Therefore, the AP can transmit the SU PPDU including information on the punctured RUs among the RUs assigned to the STA (e.g., the puncturing pattern of the RUs, etc.). That is, in the case of a SU PPDU, a puncturing mode field including information indicating whether a puncturing mode is applied and the puncturing pattern in a bitmap format, etc., may be included in the EHT-SIG field, and the puncturing mode field may signal the type of discontinuous channels that appear within the bandwidth.

[0081] The form of the signaled discontinuous channel is limited, and indicates the BW and discontinuous channel information of the SU PPDU in combination with the value of the BW field. For example, in the case of a SU PPDU, since it is a PPDU transmitted only to a single UE, the STA can recognize the bandwidth allocated to itself from the BW field included in the PPDU, and can recognize the punctured resources of the allocated bandwidth from the puncturing mode field of the U-SIG field or EHT-SIG field included in the PPDU. In this case, the UE can receive the PPDU in the remaining resource units except for the specific channel of the punctured resource unit. In this case, the multiple RUs allocated to the STA may be configured with different frequency bands or tones.

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

[0083] The present invention proposes a method for signaling the discontinuous channel type of the SU PPDU, shows the discontinuous channel type determined by the proposed method, and proposes a method for signaling the puncturing types of the primary 160 MHz and secondary 160 MHz in the 320 MHz BW configuration of the SU PPDU.

[0084] In addition, in one embodiment of the present invention, a method is proposed in which the configuration of the PPDU indicated by the preamble puncturing BW value is changed according to the PPDU format signaled in the PPDU format field. Assuming that the length of the BW field is 4 bits, in the case of an EHT SU PPDU or TB PPDU, one symbol of EHT-SIG-A may be further signaled after the U-SIG, or EHT-SIG-A may not be signaled at all. Taking this into consideration, it is necessary to signal up to 11 puncturing modes using only the BW field of the U-SIG. However, in the case of an EHT MU PPDU, since an EHT-SIG-B is further signaled after the U-SIG, up to 11 puncturing modes may be signaled in a different manner from the SU PPDU. In the case of an EHT ER PPDU, the BW field is set to 1 bit, and it is possible to signal whether the PPDU uses a bandwidth of 20 MHz or 10 MHz.

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

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

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

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

[0092] The EHT MU PPDU described in (c) of FIG. 8 can be used by the AP for downlink transmission to multiple STAs. In this case, the EHT MU PPDU can include scheduling information so that multiple STAs can simultaneously receive the PPDU transmitted from the AP. The EHT MU PPDU can convey AID information of the receiver and / or sender of the PPDU transmitted through the user specific field of the EHT-SIG-B to the STA. Therefore, multiple terminals receiving the EHT MU PPDU can perform spatial reuse based on the AID information of the user specific field included in the preamble of the received PPDU.

[0093] Specifically, the resource unit allocation (RA) field of the HE-SIG-B field included in the HE MU PPDU may include information regarding a resource unit configuration (e.g., a resource unit division form) in a specific bandwidth (e.g., 20 MHz, etc.) on the frequency axis. That is, the RA field may indicate a resource unit configuration divided by a bandwidth for transmitting the HE MU PPDU so that the STA receives the PPDU. Information on the STA allocated (or designated) to each divided resource unit may be included in a user specific field of the EHT-SIG-B and transmitted to the STA. That is, the user specific field may include one or more user fields corresponding to each divided resource unit.

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

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

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

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

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

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

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

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

[0102] Also, an AP MLD (Multi-link Device) may be a device including one or more wireless access points (APs) and connected to a higher layer via one interface. That is, the AP MLD may be connected to a Logical Link Control (LLC) layer via one interface. Multiple APs included in the AP MLD may share some functions in the MAC layer. Each AP in the AP MLD may operate on an individual link. An STA MLD may be a device including one or more non-AP STAs and connected to a higher layer via one interface.

[0103] That is, the STA MLD may be connected to the LLC layer through one interface. A plurality of STAs included in the STA MLD may share some functions in the MAC layer. The STA MLD may also be called a non-AP MLD. In this case, the AP MLD and the STA MLD may perform a multi-link operation in which communication is performed using a plurality of individual links. That is, when the AP MLD includes a plurality of APs, each AP may configure a separate link and perform frame transmission / reception operations using the plurality of links with each terminal included in the STA MLD. In this case, each link may operate in a 2.4 GHz, 5 GHz, or 6 GHz band, and each link may perform a bandwidth extension operation. For example, when the AP MLD sets one link in the 2.4 GHz band and two links in the 5 GHz band, the 2.4 GHz band may transmit frames at a bandwidth of 40 MHz using a bandwidth extension method, and each link using the 5 GHz band may transmit frames at a bandwidth of up to 320 MHz using discontinuous bandwidths.

[0104] Meanwhile, the AP MLD or STA MLD may not allow a terminal in the MLD to receive while another terminal in the MLD is transmitting due to interference issues within the device. Such an operation in which one AP or terminal in the MLD receives while another AP or terminal in the MLD is transmitting is called STR (Simultaneous Transmit and Receive). The AP MLD is capable of STR operation for all links. Or, STR operation is not possible for some links of the AP MLD. An STR-capable terminal MLD may be connected to the AP MLD, or an STR-incapable MLD may be connected to some or all links. In addition, a terminal (e.g., IEEE 802.11a / b / g / n / ac / ax terminal) that does not belong to the MLD may be further connected to an AP included in the AP MLD.

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

[0106] The STA MLD, which has confirmed whether the AP MLD operates 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 a connection process between an AP belonging to the AP MLD and a terminal belonging to the STA MLD. That is, an arbitrary terminal (e.g., STA1) belonging to the STA MLD can transmit an indicator indicating that the terminal's multiple link operation is available and a request indicator requesting the terminal to perform the multiple link operation while transmitting a connection request frame to an arbitrary AP (e.g., AP1) belonging to the AP MLD. The AP receiving the connection request frame from the terminal can confirm the indicator requesting the multiple link operation, and can transmit a connection response frame to the terminal that allows the multiple link operation, including link information used for the multiple link operation and parameters used for each link, if the AP is capable of the multiple link operation. The parameters for the multi-link operation may include one or more of the bandwidth of each link used, the bandwidth expansion direction, a Target Beacon Transmission Time (TBTT), and the presence or absence of an STR operation. The AP MLD and the STA MLD in which the use of the multi-link operation is confirmed by exchanging the connection request frame and the response frame can perform a frame transmission operation on multiple links via multiple APs included in the AP MLD and multiple terminals included in the STA MLD after the connection process.

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

[0108] According to an embodiment of the present invention, the multi-link operation may include a multi-link setup operation. The multi-link setup operation may be an operation corresponding to an association performed in a single-link operation. In order to exchange frames in the multi-link, the multi-link setup must be performed in advance. The multi-link setup operation may be performed using a multi-link setup element. Here, the multi-link setup element may include capability information related to the multi-link, and the capability information may include information on whether a STA included in the MLD can receive a frame in one link and another STA included in the MLD can transmit a frame in another link at the same time. That is, the capability information may include information on whether a STA (non-AP STA and / or an AP (or AP STA) can simultaneously transmit / receive frames in different transmission directions through a link included in the MLD. The capability information may further include information on an available link or an operating channel. The multi-link setup may be set up through negotiation between peer STAs, and the multi-link operation may be set up through one link.

[0109] According to an embodiment of the present invention, a mapping relationship may exist between TIDs and MLD links. For example, when a TID and a link are mapped, the TID may be transmitted on the mapped link. The mapping between TIDs and links may be directional-based. For example, a mapping may be performed for each direction between MLD1 and MLD2. Also, a default setting may exist for the mapping between TIDs and links. For example, the mapping between TIDs and links may basically be that all TIDs are mapped to a certain link.

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

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

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

[0114] The value of AC may be set to one of AC_BK, AC_BE, AC_VI, and AC_VO. AC_BK, AC_BE, AC_VI, and AC_VO may indicate background, best effort, video, and voice, respectively. AC_BK, AC_BE, AC_VI, and AC_VO can be further subdivided. For example, AC_VI may be further subdivided into AC_VI primary and AC_VI alternate. AC_VO may be further subdivided into AC_VO primary and AC_VO alternate. UP values ​​or TID values ​​may be mapped to AC values. For example, UP values ​​or TID values ​​1, 2, 0, 3, 4, 5, 6, and 7 may be mapped to AC_BK, AC_BK, AC_BE, AC_BE, AC_VI, AC_VI, AC_VO, and AC_VO, respectively. Alternatively, the UP or TID values ​​1, 2, 0, 3, 4, 5, 6, and 7 may be mapped to AC_BK, AC_BK, AC_BE, AC_BE, AC_VI alternate, AC_VI primary, AC_VO primary, and AC_VO alternate, respectively. Also, the UP or TID values ​​1, 2, 0, 3, 4, 5, 6, and 7 may have increasing priority in order. That is, 1 may be a lower priority, and 7 may be a higher priority. Therefore, the order of priority may be AC_BK, AC_BE, AC_VI, and AC_VO. Also, AC_BK, AC_BE, AC_VI, and AC_VO may correspond to ACI (AC index) 0, 1, 2, and 3, respectively.

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

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

[0117] In the present invention, a data frame corresponding to a TID or AC that is mapped to either direction of the link may be transmitted, and a data frame corresponding to a TID or AC that is not mapped to either direction of the link may not be transmitted.

[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. Or, the TID-to-link mapping may be based on the block ack agreement. For example, a block ack agreement may exist for a TID-to-link mapped TID.

[0119] By performing TID-to-link mapping, it is possible to provide QoS services. For example, by mapping a high-priority AC and TID to a link with good channel conditions or few STAs, it is possible to transmit data of the AC and TID quickly. Or, by performing TID-to-link mapping, it is possible to help STAs of a specific link save power (or enter a doze state).

[0120] 10, an AP MLD including AP1 and AP2 may exist. A Non-AP MLD including STA1 and STA2 may also exist. A plurality of links, Link1 and Link2, may exist in the AP MLD. AP1 and STA1 may be associated with each other via Link1, and AP2 and STA2 may be associated with each other via Link2.

[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 an AC.

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

[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 MLD simultaneous transmit and receive (STR) operation 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, when the spacing between links is m MHz, simultaneous transmission or reception may be restrictive, and when the spacing between links is n MHz for n greater than m, simultaneous transmission or reception may not be restrictive. This embodiment may be for solving the problem of simultaneous transmission or reception being restrictive, and repeated explanations may be omitted. This embodiment may also be applied to MLDs that do not support STR.

[0126] According to an embodiment of the present invention, duration information may be shared between links operating as a multiple link. As an embodiment, the duration information may be TXOP duration information transmitted in a signaling field of a preamble. The signaling field may be the U-SIG field described above. Or, the signaling field may be the HE-SIG-A field described above. As yet another embodiment, the duration information may be duration information indicated by a Duration / ID field included in a MAC header. As yet another embodiment, the duration information may be duration information indicated by a Length field (L Length field) included in an L-SIG field. According to an embodiment, the duration information indicated by the U-SIG field, HE-SIG-A, or Duration / ID field may be a value indicating a TXOP duration. According to an embodiment, the duration information indicated by the L-SIG field may be a value indicating the length of a physical layer protocol data unit (PPDU) including the L-SIG field or an end of a PPDU including the L-SIG field.

[0127] Also, according to an embodiment of the present invention, it is possible to restrict transmission or channel connection to a period based on period information shared between links. The method of restricting transmission or channel connection may include setting a NAV. Alternatively, the NAV may be reset to resume transmission or channel connection. In this case, the NAV may be an intra-BSS NAV. The intra-BSS NAV may be a NAV set by an intra-BSS frame (or PPDU). That is, a STA belonging to an MLD may set a NAV based on a frame (or PPDU) directed to another STA belonging to the MLD.

[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 may not be required on link 2 based on the inter-link NAV set based on period information received on link 1. Also, the inter-link NAV may exist or be used for an MLD that is not capable of STR. For example, when an inter-link NAV is set, the MLD that sets the inter-link NAV may not transmit or connect channels on multiple links (or all links used by the MLD).

[0129] In addition to the intra-BSS NAV, a basic NAV may be included as a type of NAV. The basic NAV may be a NAV set by an inter-BSS frame (or a PPDU), and the basic NAV may also be set by a frame (or a PPDU) that does not determine whether it is an intra-BSS or inter-BSS frame (or a PPDU).

[0130] When the inter-link NAV is used separately, it may have an advantage in a situation where the NAV setting is updated compared to when the inter-link NAV is not used. For example, a situation may occur where it is acceptable to reset the NAV set by another link. For example, when the inter-link NAV is set based on a certain frame (or PPDU), it may be acceptable to reset the set inter-link NAV because it is determined that the frame (or PPDU) is not directed to the same MLD. If there is an MLD that operates on link 1 and link 2, the NAV for link 1 may be set based on a frame received on link 1. Then, the NAV for link 1 may be updated based on a frame of link 2. If the NAV for link 1 is reset when it is no longer necessary to maintain the NAV for link 2, there is a problem in that the NAV information set based on the frame received on link 1 is lost. If the inter-link NAV is used together with the NAV for each link, the NAV for each link is maintained even if the inter-link NAV is reset, and the above problem can be solved.

[0131] Although the embodiment of the present invention deals with setting the NAV, the embodiment of the present invention is not limited to this and can be applied to instructing the physical layer to suspend the channel connection or instructing the channel state to be busy. Also, the embodiment is not limited to resetting the NAV and can be applied to instructing the physical layer to continue the 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 of the MLD and another STA may be used. Alternatively, a primitive exchanged between one MAC layer of the MLD and another MAC layer may be used.

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

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

[0136] According to an embodiment of the present invention, when STA1 starts receiving a frame, STA2 may suspend the channel connection. Also, when STA1 obtains duration information from the L-SIG, STA2 may maintain the suspended state of the channel connection. At this time, STA2 can determine that the suspended state of the channel connection will last until the end of the frame received by STA1. Also, when STA1 cannot certainly decode the L-SIG (if it is an invalid L-SIG), STA2 can resume the channel connection.

[0137] Also, STA1 can receive the TXOP duration and BSS color from the U-SIG of the frame received. If the received BSS color indicates intra-BSS or the BSS color is the BSS color corresponding to STA1, the channel connection can be suspended. In one embodiment, the duration for suspending the channel connection at this time may be until the end of the received frame. In this case, there is an advantage that the channel connection can be started sooner after the end of the received frame. In another embodiment, the duration for suspending the channel connection at this time may be the TXOP duration. In this case, the duration of the suspended channel connection may be updated based on the L-SIG. In this case, there is an advantage that the sequence following the received frame can be better protected.

[0138] Or, STA1 may receive TXOP duration and BSS color from the U-SIG of the received frame, and the received BSS color may indicate that it is not intra-BSS, or the BSS color may not be the BSS color corresponding to STA1. Or, STA1 may not be able to successfully decode the U-SIG. In such a case, STA2 may resume the channel connection.

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

[0141] Also, STA2 may receive a STA-ID from the EHT-SIG of a frame received by STA1. If the received STA-ID is an indicator that STA1 should receive, for example, if the STA-ID indicates STA1, indicates a group to which STA1 belongs, or indicates broadcast, STA2 can maintain a state in which the channel connection is suspended.

[0142] Or, STA1 may receive a STA-ID from the EHT-SIG of the frame it receives. If the received STA-ID is an indicator that does not correspond to STA1, for example, if the STA-ID does not indicate an indicator that corresponds to STA1, if the STA-ID does not indicate a group to which STA1 belongs, or if the STA-ID does not indicate broadcast, STA2 can resume the channel connection. Or, STA2 can resume the channel connection even if STA1 fails to successfully decode the EHT-SIG.

[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-mentioned operation can be performed.

[0144] Also, STA2 may receive the MAC header of a frame received by STA1. If the RA (receiver address) or DA (destination address) included in the received MAC header indicates a value to be received by STA1, for example, if the RA or DA indicates STA1, indicates a group to which STA1 belongs, or the STA-ID indicates broadcast, STA2 can maintain the state in which the channel connection is suspended. At this time, the duration of the suspended channel access may be based on the duration information included in the received MAC header. More specifically, the duration of the suspended channel access may be based on the duration information indicated by the Duration / ID field included in the received MAC header.

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

[0146] The channel connection interruption and resumption described in FIG. 12 may be performed in the order of decoding as STA1 starts receiving frames (or PPDUs) and sequentially decodes them. The decoding order may be based on the PPDU format, frame format, etc. For example, the order of decoding may be L-SIG, U-SIG, EHT-SIG, and MAC header (in the case of EHT PPDU). Or, the order of decoding may be L-SIG, HE-SIG-A, and MAC header (in the case of HE SU PPDU and HE TB PPDU). Or, the order of decoding may be L-SIG, HE-SIG-A, HE-SIG-B, and MAC header (in the case of HE MU PPDU). Or, the order of decoding may be L-SIG and MAC header (in the case of 11a / g PPDU).

[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 or an HE-SIG-B field, etc. The STA-ID may indicate a value corresponding to a single STA. For example, when multiple STAs are included in an MLD, the STA-ID may indicate a value corresponding to one of the multiple STAs. The STA-ID may be a value based on the AID or MAC address of the STA.

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

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

[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 according to whether or not at least one of the one or more BSS classification conditions is satisfied.

[0152] The BSS classification condition may include a condition based on a BSS color. The BSS color may be an identifier for a BSS. The BSS color may be included in a preamble of a PPDU, more specifically, in a signaling field (e.g., a HE-SIG-A field, a U-SIG field, or a VHT-SIG-A field). The BSS color may be included in a TXVECTOR transmitted from a MAC layer of a sender to a PHY layer. The BSS color may be included in an RXVECTOR transmitted from a PHY layer of a receiver to a MAC layer. The parameters included in the TXVECTOR and RXVECTOR may be referred to as a TXVECTOR parameter and an RXVECTOR parameter, respectively. The BSS color may be included in a TXVECTOR parameter or an RXVECTOR parameter. The BSS color set by the AP may be notified to the STA. According to an embodiment, the BSS may be classified based on the BSS color included in the received PPDU. If the BSS color included in the PPDU received by the STA is different from the BSS color of the BSS corresponding to the STA, the received PPDU can be classified as an inter-BSS PPDU. Alternatively, if the BSS color included in the PPDU received by the STA is different from the BSS color of the BSS corresponding to the STA and its value is not 0, the received PPDU can be classified as an inter-BSS PPDU. Also, if the BSS color included in the PPDU received by the STA is the same as the BSS color of the BSS corresponding to the STA, the received PPDU can be classified as an intra-BSS PPDU.

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

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

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

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

[0157] The BSS classification condition may include a condition for the AP to receive a PPDU of a pre-set condition. For example, the PPDU of the pre-set condition may include a downlink PPDU. According to an embodiment, the downlink PPDU may include a VHT MU PPDU. Also, the downlink PPDU may include a PPDU in which signaling indicating uplink or downlink is set to a pre-set value. The signaling indicating uplink or downlink may be included in a signaling field of a HE PPDU. Alternatively, the signaling indicating uplink or downlink may be included in a U-SIG. The U-SIG may be included in a preamble of an EHT PPDU or a post-EHT standard PPDU.

[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 satisfied, a PPDU cannot be classified as an intra-BSS PPDU or an inter-BSS PPDU.

[0159] In addition, when classifying a BSS, if the classification results based on multiple conditions do not match, it is possible to determine the final result based on the previously set conditions. For example, if the result based on the condition based on the BSS color does not match the result based on the condition based on the MAC address, the result based on the condition based on the MAC address is prioritized, or the result based on the condition based on the MAC address can be determined as the final result. Or, if both the conditions for classifying as an intra-BSS PPDU and the conditions for classifying as an inter-BSS PPDU are met, the PPDU can be classified as an intra-BSS PPDU.

[0160] According to an embodiment of the present invention, the STA may perform an operation based on the classified BSS. The operation based on the classified BSS may include an intra-PPDU power save operation. The intra-PPDU power save operation may be a power save operation based on a received PPDU. When a pre-set condition is satisfied, the intra-PPDU power save operation can be performed. The pre-set condition may include a condition for classifying a received PPDU as an intra-BSS PPDU. The pre-set condition may also include a condition for an intended receiver of a received PPDU not to be a STA that has received the PPDU. For example, if an ID or address included in a PPDU does not correspond to a STA that has received the PPDU, the intended receiver of the PPDU may not be a STA that has received the PPDU. The ID may be included in a preamble of the PPDU. For example, the ID may be a STA_ID included in a preamble of the PPDU. The STA_ID may be included in a HE MU PPDU or an EHT PPDU. The addresser may be the MAC address described above. Also, when the signaling indicating uplink or downlink included in the received PPDU indicates uplink, the intended recipient of the PPDU may not be the STA that received the PPDU. Also, when the configuration of the received PPDU is set to one that the STA that received the PPDU does not support, the intended recipient of the PPDU may not be the STA that received the PPDU. The configuration of the received PPDU may include the MCS of the PPDU, the number of spatial streams, a channel width, etc. Also, when the STA that received the PPDU does not support the configuration of the received PPDU, a PHY-RXEND.indication(UnsupportedRate) primitive may be received. Also, when the received PPDU is in a format that has already been set, the intended recipient of the PPDU may not be the STA that received the PPDU. The already set format may include a TB PPDU.The TB PPDU may include an HE TB PPDU and an EHT TB PPDU. Also, the TB PPDU may be a PPDU transmitted as a response to the 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. Also, the triggering information or the information included in the trigger frame may include a length of the responding PPDU, an RU to be used in the response, a PHY configuration to be used in the response, a MAC configuration, etc. The intra-PPDU power saving operation may be an operation that may enter a doze state until the end of the received PPDU. As yet another embodiment, when it is determined that the STA is not the intended recipient of the received PPDU or frame, the STA may suspend reception or decoding of the PPDU or frame.

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

[0162] The operation based on the classified BSS may include a spatial reuse operation. Also, the operation based on the classified BSS may include a channel access operation. The spatial reuse operation may be a channel access operation. When a STA receives a PPDU or a frame, if a pre-set condition is satisfied, the spatial reuse operation can be performed. The pre-set condition may include a condition that the received PPDU or the received frame corresponds to an inter-BSS. Also, the pre-set condition may include a condition that the signal strength of the received PPDU or the received frame is smaller than a threshold. For example, the threshold may be variable. Also, the threshold may be a threshold for an OBSS PD-based spatial reuse operation. Also, the threshold may be a value equal to or greater than the CCA threshold. Also, the threshold may be a value based on the power to be transmitted. The spatial reuse operation may include an operation of transmitting a PPDU. Also, the spatial reuse operation may include an operation of resetting a PHY. For example, resetting the PHY may be issuing a PHY-CCARESET.request primitive. Spatial reuse may include not setting a NAV based on a received PPDU or a received frame. If a STA performs spatial reuse, the STA may be able to transmit a PPDU while a received PPDU or a received frame is being transmitted or received.

[0163] Referring to FIG. 13, there may be BSS A and BSS B, which may be different BSSs. Furthermore, BSS A and BSS B may correspond to inter-BSS. That is, a PPDU or frame transmitted by a STA associated with BSS A in BSS B may be classified as an inter-BSS PPDU or an inter-BSS frame. Furthermore, there may be STA1 and STA2 belonging to BSS A (or associated with an AP operating BSS A). There may be STA3 and STA4 belonging to BSS B (or associated with an AP operating BSS B). Referring to FIG. 13, STA1 may transmit a PPDU. Furthermore, the PPDU transmitted by STA1 may include information on the BSS. For example, the information on the BSS may be information for classifying the above-mentioned BSS. Furthermore, the PPDU transmitted by STA1 may include Duration information.

[0164] STA2 receives the PPDU transmitted by STA1 and can classify the BSS for this PPDU. Also, since STA2 and STA1 belong to BSS A, the PPDU received by STA2 may be classified as an intra-BSS PPDU. Also, the PPDU received by STA2 may be a UL PPDU or a PPDU for which the STA is not the intended recipient. Therefore, according to the above-mentioned embodiment, STA2 can perform intra-PPDU power saving. Referring to FIG. 13, STA2 can enter a doze state until the end of the received PPDU. Also, STA2 can set a NAV based on the Duration information included in the received PPDU. Since STA2 has classified the received PPDU as an intra-BSS PPDU, it can set an intra-BSS NAV.

[0165] STA3 receives the PPDU transmitted by STA1 and can classify the BSS for this PPDU. In addition, since STA3 and STA1 belong to BSS B and BSS A, respectively, the PPDU received by STA3 may be classified as an inter-BSS PPDU. In addition, STA3 can set the NAV based on the Duration information included in the received PPDU. Since STA3 has classified the received PPDU as an inter-BSS PPDU, it can set the basic NAV.

[0166] STA4 receives the PPDU transmitted by STA1 and can classify the BSS for this PPDU. In addition, since STA4 and STA1 belong to BSS B and BSS A, respectively, the PPDU received by STA4 may be classified as an inter-BSS PPDU. In addition, the signal strength of the PPDU received by STA4 may be smaller than a threshold. Therefore, since the PPDU received by STA4 is classified as an inter-BSS PPDU and the signal strength of the PPDU received by STA4 is smaller than a threshold, STA4 can perform spatial reuse operation. Therefore, STA4 can perform channel connection and backoff procedure, and can start transmission. For example, STA4 may be able to start transmission before the PPDU transmitted by STA1 is finished.

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

[0168] Referring to FIG. 14, a wireless LAN of a certain standard may include the function of a wireless LAN of another standard. Or, when a wireless LAN of a certain standard is used, it may be a wireless LAN of another standard. Here, the wireless LAN may mean an STA. Furthermore, here, the wireless LAN may mean an MLD including an STA. For example, the wireless LAN standard may include a standard function of a previous generation and may include additional functions. For example, an HT STA may be an OFDM PHY STA. Also, an HT STA may perform additional functions in addition to the functions of an OFDM PHY STA. For example, an VHT STA may be an HT STA. Also, an VHT STA may perform additional functions in addition to the functions of an HT STA. For example, an HE STA may be a VHT STA. Also, an HE STA may perform additional functions in addition to the functions of a VHT STA. Also, an EHT STA may be an HE STA. Also, an EHT STA may perform additional functions in addition to the functions of an HE STA. Also, there may be a standard after the EHT standard. In the present invention, the standard after the EHT standard can be called the NEXT standard, and the STA following 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, if it is an EHT STA, it can be an HE STA, a VHT STA, a HT STA, or an OFDM PHY STA. Also, if it is a NEXT STA, it can be an EHT STA, a HE STA, a VHT STA, a 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 format 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 the frame. In this case, when one or more STAs transmit a response to the frame, the one or more STAs may respond simultaneously (simultaneous) immediately based on the frame, and the response to the frame may start transmission SIFS after the end of the PPDU including the frame. For example, when the frame solicits an immediate response, one or more STAs may transmit a response to the frame immediately. A frame soliciting or triggering one or more STAs to transmit may be a trigger frame or a frame including information in a MAC header that solicits or triggers one or more STAs to transmit uplink. In this case, the frame may include information (e.g., a TRS control subfield) in a 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, and 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 preamble 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 required for one or more STAs to transmit a TB PPDU. For example, if a type subfield included in a frame is "01" (B3 B2) and a subtype subfield is "0010" (B7 B6 B5 B4), the frame including such a type subfield and a subtype subfield may be a trigger frame, which is a control frame.

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

[0179] Therefore, in order to solve this problem, when multiple STAs respond to the AP frame, 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 PPDU as a response to the AP frame, the AP may transmit information so that the information included in L-STF, L-LTF, L-SIG, RL-SIG, and HE-SIG-A is the same so that the AP can successfully receive the preambles transmitted by the multiple STAs, or a promise may be set for the information included in the HE TB PPDU. However, if the HE TB PPDU, EHT TB PPDU, and NEXT TB PPDU are simultaneously transmitted in overlapping subbands, a problem may occur in which the AP has difficulty receiving them because the TB PPDU formats are different from each other.

[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, and a NEXT STA can transmit a NEXT TB PPDU, an EHT TB PPDU, or an HE TB PPDU, because a STA of a certain standard may include a function of a previous standard, as described in FIG.

[0181] As shown in FIG. 15, when the AP transmits a frame for scheduling the transmission of the TB PPDU to the HE STA and the EHT STA, and instructs or triggers the transmission of the TB PPDU using the frame, there may be no precise instruction or protocol for the TB PPDU format. In this case, the HE STA transmits the HE TB PPDU as a response to the frame, and the EHT STA can respond with the EHT TB PPDU or the HE TB PPDU. In this case, the AP may have difficulty receiving the TB PPDU transmitted by these STAs, and even if the AP does not successfully receive the TB PPDU from multiple STAs and does not successfully transmit, the medium is occupied, and there may be a problem that the transmission opportunity of other STAs is reduced.

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

[0183] In addition, the HE trigger frame, the EHT trigger frame, and the NEXT trigger frame may be trigger frames defined in the HE, EHT, and NEXT standards, respectively. In addition, in the present invention, the HE TRS, the EHT TRS, and the 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] FIG. 16(a) shows the trigger frame format, and FIG. 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, and 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 applicable to all STAs designated by the trigger frame. An example of the common information field is shown in (b) of FIG.

[0188] The user information list field may include 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 include one or more user information fields. Figure 16 (c) 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 selectively included in the trigger frame.

[0190] Referring to (b) of FIG. 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 the trigger frame may be indicated based on the value of the trigger frame subfield. Also, based on the trigger type subfield, the information and length included in the trigger dependent common information subfield and the trigger dependent user information subfield shown in FIG. 12 may be determined. 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 length subfield (Uplink (UL) length subfield). The UL length subfield may include information on the length of a TB PPDU, which is a response to the trigger frame, or may include information on the length of a frame responding to the trigger frame. In addition, the UL length subfield may indicate a 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 may 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 may 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 may 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 indicating the UL length subfield.

[0192] In addition, 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 a maximum BW of a TB PPDU transmitted in response to the trigger frame. Therefore, the STA may set a BW value included in a signaling field of a 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, etc. 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 an intended recipient of a user information field including the AID12 subfield or a function of the user information field. Thus, the AID12 subfield may also serve to indicate an intended recipient of a trigger frame including the AID12 subfield or a function of the trigger frame. For example, when 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 a RA-RU. Specifically, when the value of the AID12 subfield is "0", the user information field may indicate a RA-RU for associated STAs. For example, when the value of the AID12 subfield is "0", the user information field can indicate an RA-RU for associated STAs, and when the value of the AID12 subfield is "2045", the user information field can indicate an RA-RU for unassociated STAs. A STA corresponding to a 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 an AID subfield. For example, the AID12 subfield can indicate an AID or 12 LSBs of the AID. A STA corresponding to a 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 a pre-set value (eg, "4095"), the pre-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 AUD12 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, a single STA can selectively transmit PPDUs of different formats based on instructions from a triggering frame instructing transmission of a PPDU.

[0199] Specifically, an EHT STA can selectively transmit an EHT TB PPDU in addition to a legacy PPDU (e.g., an HE 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 in one frame or one PPDU. Since STAs to which multiple standards are applied use common resources together in a wireless LAN, such a method can be advantageous. For example, an HE STA (HE STA other than an EHT STA) can be made to 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] Also, information for selecting the TB PPDU format may be included in a triggering frame, which is a triggering 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 the PPDU to be responded to based on the information included in the received triggering frame. Then, the at least one non-AP STA can transmit the PPDU to the AP based on the selected format.

[0201] Information regarding 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 the trigger frame into an HE trigger frame, an EHT trigger frame, and a NEXT trigger frame may have the same meaning as dividing the TB PPDU format, which is a response to the trigger frame, into an HE TB PPDU, an EHT TB PPDU, and a NEXT TB PPDU, respectively.

[0203] Whether the format of the trigger frame for distinguishing the format of the 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 the 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. In addition, if the values ​​of the Type subfield, the Subtype subfield, and / or the Control Frame Extension subfield are already set, the trigger frame may be identified as an HE trigger frame, and if the values ​​are other already set, the trigger frame may be identified as an EHT trigger frame. In addition, if the values ​​of the Type subfield, the Subtype subfield, and / or the Control Frame Extension subfield are other already set, 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 the entries of the type subfield (2 bits), the subtype subfield (4 bits), and / or the control frame extension subfield (4 bits) to which a limited number of bits are assigned 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 a common information field included in the trigger frame. That is, the format of the PPDU transmitted as a 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 depending on the value of the common information field and transmit the PPDU 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 a 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, when the variant for determining the format of the PPDU is determined to be the HE variant by the common information field, the non-AP STA may respond with the HE TB PPDU, and when the variant for determining the format of the PPDU is determined to be the EHT variant by the common information field, the non-AP STA may respond with the EHT TB PPDU.

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

[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 a 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 is 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, the trigger frame may be determined 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, the trigger frame may be determined 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. That is, the format of a PPDU transmitted in response to a trigger frame may be determined as an HE PPDU or an EHT PPDU using the value of the UL length subfield.

[0211] More specifically, the trigger frame can be classified 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 mod (remainder) 3 (the remainder when the UL length subfield is divided by 3). For example, if the result of modulating the UL length subfield value mod 3 is not 0, the trigger frame may be an HE trigger frame. Or, if the result of modulating the UL length subfield value mod 3 is 1, the trigger frame may be an HE trigger frame. Or, if the result of modulating the UL length subfield value mod 3 is 0, the trigger frame may not be an HE trigger frame. Or, if the result of modulating the UL length subfield value mod 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] In addition, the above method may be used together with an additional trigger frame classification method to classify the HE trigger frame, the EHT trigger frame, and the NEXT trigger frame. For example, the classification method described in FIG. 16 may be used together to classify the HE trigger frame, the EHT trigger frame, and the NEXT trigger frame.

[0215] According to an 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-mentioned 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 be further used to identify the format of the PPDU.

[0217] That is, a variant for determining a 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 by the determined variant. For example, when the variant for determining the format of the PPDU is determined to be the HE variant by the user information field, the non-AP STA can respond with the HE TB PPDU, and when the variant for determining the format of the PPDU is determined to be the EHT variant by the user information field, the non-AP STA can respond with the 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, it may be determined whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame based on the AID12 subfield. According to an embodiment, it may be determined whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame depending on whether the AID12 subfield of a previously set value is included. In this case, it may be a problem 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 present at the front of the user information list. In addition, in order to prevent a HE STA that cannot understand such a signaling method from malfunctioning, a user information field including an AID12 subfield indicating which trigger frame it is may be present after the user information field corresponding to the HE STA.

[0220] In addition, since information of other subfields than the AID12 subfield included in the user information field may not be necessary for the TB PPDU response, the 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 play a role in indicating a TB PPDU format to be responded to. For example, when the AID12 subfield is a previously set value, the response to the trigger frame including the AID12 subfield set to the previously set value may be an EHT TB PPDU. For example, when the AID12 subfield value is 2047, the response to the trigger frame including the AID12 subfield may be an EHT TB PPDU. Also, when the AID12 subfield is a previously set value, the response to the trigger frame including the AID12 subfield set to the previously set value may be a NEXT TB PPDU. For example, if the AID12 subfield value is 2048, the response to a trigger frame including the AID12 subfield may be a NEXT TB PPDU.

[0221] According to another embodiment, when responding based on a user information field existing at an already set position from an AID12 subfield of a previously set value, it can respond in a TB PPDU format corresponding to the previously set value. For example, when responding based on a user information field existing after an AID12 subfield of a previously set value, it can respond in a TB PPDU format corresponding to the previously set value. If there are a plurality of values ​​indicating a TB PPDU format, when responding based on a user information field existing after both a previously set value 1 and a previously set value 2, it can respond in a TB PPDU format according to a previously set priority among the TB PPDU format corresponding to the previously set value 1 and the TB PPDU format corresponding to the previously set value 2. Referring to FIG. 15, when responding based on a user information field existing after an AID12 subfield set to 2047, it can respond in an EHT TB PPDU. Also, when responding based on a user information field existing after an AID12 subfield set to 2048, it can respond 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 classified 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, it may be determined whether the trigger frame is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame depending on whether the padding field includes a pre-defined 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 the trigger frame are not limited to the above, and can also be applied to the TRS.

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

[0226] FIG. 18 illustrates a 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 the TB PPDU can also be instructed by the TRS. Also, the TRS may be included in the HT control field as described above. For example, when the HT control field includes the A-control field, the TRS can be included. The TRS can be conveyed by the TRS control subfield. The A-control field may be in the form of a continuous control list field. Also, the control list field may include the TRS.

[0228] Also, a receiver of a frame including a TRS 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), a 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 be applied to the TRS. Also, the above-mentioned contents can be omitted.

[0230] According to an embodiment of the present invention, in addition to the TRS defined in the HE standard (HE TRS), there may also be TRS defined in the EHT standard or the NEXT standard (EHT TRS, NEXT TRS, respectively). 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, which standard the TRS is defined in may be determined by the Control ID subfield of the A-Control subfield. As an additional embodiment, the TRS may be divided into two types: the HE TRS and a TRS other than the HE TRS.

[0231] Or, for example, which standard defines the TRS 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 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 an embodiment of the present invention, it is possible to determine a TB PPDU format in response to a TRS based on a PPDU format including the TRS. That is, when a PPDU instructing transmission of a PPDU includes a TRS control subfield, the format of the PPDU 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 a HE PPDU, a TB PPDU in response to the TRS may be a HE TB PPDU. When a TRS is transmitted in an EHT PPDU, a TB PPDU in response to the TRS may be an EHT TB PPDU. When a TRS is transmitted in a NEXT PPDU, a TB PPDU in response 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 the HE PPDU, the UL HE-MCS subfield (or subfield related to MCS) included in the TRS may indicate a value corresponding to the HE MCS table. When the TRS is included in the EHT PPDU, the UL HE-MCS subfield (or subfield related to MCS) included in the TRS may indicate a value corresponding to the EHT MCS table. When the TRS is included in the NEXT PPDU, the UL HE-MCS subfield (or 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 a 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 performance of the receiving device, the receiving device may not be able to transmit a response within the time required to transmit the response to the PPDU. Therefore, in order to secure 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 preset time. That is, the PE field is located at the end of the PPDU, and can provide additional processing time to the terminal, which is the receiving device.

[0239] Therefore, the PE field may be located at the end of the PPDU to provide additional processing time, or next to the data field. For example, the PPDU may include the preamble, the data field, and the PE field in this order. The preamble and the data field may be as described in the above embodiment. 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. The PPDU including the PE field may be an HE PPDU or 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, it may be difficult for a receiving device (e.g., STA) that does not have high performance to respond at 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 IFS (interframe space) or SIFS (short interframe space) from the end of the received PPDU. Therefore, the PE field, which is a field that does not need to be decoded, may be positioned at the end of the received PPDU, thereby securing time for processing the received PPDU. That is, the PPDU can be processed sufficiently quickly by positioning a field that does not need to be decoded at the end of the PPDU. Therefore, it is possible to process the PPDU including the PE field and transmit an immediate response thereto within the 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 for transmitting the data field, 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 an 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 a 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 an embodiment, the PE field of the already-set duration may be used only for the already-set configuration. For example, the already-set duration may be 20 us or more. The already-set duration may be based on the MCS (modulation and coding scheme) or modulation method. That is, the PE field of the already-set duration may be set and included in the PPDU according to the already-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 equal to or greater than a previously set MCS, a previously set duration for the modulation or 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] Besides 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, e.g., when more than eight spatial streams are used, the preset value for the duration of the PE field may be used.

[0247] In addition, the previously set value may be based on the channel width, bandwidth, or size of the RU to be transmitted. For example, when the channel width, bandwidth, or size of the RU is set to a previously set value, the duration of the PE field may be determined to be a previously set specific value.

[0248] According to an 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 PPDU or the entire PPDU transmitted simultaneously by multiple STAs. 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 particular value may be a value greater than 160 MHz, and the RU size may be greater than 2×996. Also, the RU size may be for the entire RU used for transmission, i.e., when multiple RUs are used, it may be for the sum of the sizes of multiple RUs.

[0250] That is, a previously set specific value for the duration of the PE field may be used or set only under specific conditions. For example, the duration for 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 among these, a specific value may be used or set in a PPDU under the following conditions.

[0251] - PPDU modulated using the 4096-QAM modulation scheme

[0252] - PPDUs transmitted with 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 the 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, when the PPDU indicated by the frame is the 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, when the PPDU indicated by the frame is the 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. That is, the value (e.g., the 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 the 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 the 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 the TRS to trigger the transmission of the PPDU, and the non-AP STA may transmit the PPDU as a response to the PPDU of the TRS. 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 of the action element (e.g., a default PE duration field).

[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 action element may include information related to the operation of the BSS, and may be an HE action element or an EHT action element depending on the format. Such action 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 when 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, when 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 values. 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 illustrates 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 the transmission of a PPDU (e.g., a frame including a control ID subfield having a value indicating TRS or a trigger frame instructing the transmission of a PPDU) 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, the use of 20 us may be permitted only in certain cases, as described above.

[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 the TRS of the AP, the duration for the PE field of the PPDU can be determined based on the default PE duration transmitted and indicated by the AP. In this case, the PPDU may be a HE TB PPDU, an EHT TB PPDU, or a later version TB PPDU, which is a PPDU based on a trigger frame, and the AP may be an AP associated with the non-AP STA.

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

[0272] As described above in FIG. 19 and FIG. 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 a certain time unit. If the default PE duration is instructed to the STA by the AP through 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 transmits the default PE duration and the STA (AP or AP STA) that transmits 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 according to Equation 5 below.

[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 T may be the sum of the lengths of L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, HE-STF and HE-LTF. PREAMBLE T 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 N may represent the number of data OFDM symbols included in the transmitted PPDU. For example, N SYM may be determined according to Equation 7 below.

[0279]

number

[0280] In formula 7, b PE_Disambiguity may be the TXVECTOR parameter TB_PE_DISAMBIGUITY value, or PE_disambiguitymay be a value of the PE Disambiguity subfield included in the trigger frame. Also, the TXVECTOR parameter TB_PE_DISAMBIGUITY may be a TXVECTOR parameter HE_TB_PE_DISAMBIGUITY when transmitting an HE PPDU. The TXVECTOR parameter TB_PE_DISAMBIGUITY may be a 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 previously set 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 PPDU, 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 aid in channel estimation of the receiver.

[0283] N LTF may be the number of LTFs included in the preamble, in which case the LTF may be the HE-LTF when an HE PPDU is transmitted, or the LTF may be the 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 the HE-LTF when transmitting the HE PPDU, or the LTF may be the EHT-LTF when transmitting the EHT PPDU. LTFSYM may be a value including the GI.

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

[0286]

number

[0287] As shown in FIG. 21, when a TB PPDU is instructed to be transmitted by a trigger frame, the STA transmits a T PE In this case, a PPDU containing a PE field having a duration of 0.5 ms can be transmitted.

[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 the fields 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 to the trigger frame may be set to a value indicated by the default PE duration subfield. PE The value of the field to calculate TPE may be set to be the same as the value indicated by the Default PE Duration subfield.

[0290] For example, when one PPDU includes a trigger frame and a TRS instructing different STAs to transmit a TB PPDU, 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., a PE field duration of 20 us is permitted), and the duration of the PE field included in the TB PPDU triggered by the TRS may be a maximum of 16 us due to the default PE subfield. In this case, the T PE The value of the subfields (e.g., LENGTH field and / or PE Disambiguity subfield) for calculating the duration by the default PE subfield and T PE may be set to be identical.

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

[0292] In this case, a terminal whose TB PPDU transmission is triggered by the 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 subfield values ​​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] In other words, when the maximum value for the duration of the PE field of the TB PPDU by 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 by 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 0us, 4us, 8us, 12us, or 16us (or 0us, 4us, 8us, 12us, 16us, or 20us), the T calculated by the trigger frame is PE and the value indicated by the Default PE Duration subfield may be identical.

[0295] Therefore, according to an embodiment of the present invention, when a TRS and a trigger frame for triggering 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 including 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. Thus, the AP may set the default PE duration to a sufficiently large value in order to successfully receive a PPDU or to 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. Thus, in order to use the previously set configuration when responding to a TRS or a trigger frame included in a PPDU including a TRS, it may be necessary to set a larger value of 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, even if the previously set configuration is not used, a long default PE duration must be used, which may be redundant. That is, even for PPDUs that can be received without the 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 16us. Therefore, a problem may occur in that a setting that requires a PE field longer than that may be difficult to trigger with 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 to solve 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, in order to solve the problem described in FIG. 21, the value of the PE field of a PPDU triggered by a trigger frame or a TRS may be restricted.

[0301] Specifically, when a response of the STA is triggered, the STA may be instructed to respond using a limited setting. For example, when triggering using a TRS or a trigger frame included in a PPDU including a TRS, the STA may be instructed to respond using the limited setting. In addition, the method of instructing may include instructing using a subfield included in the TRS or the trigger frame. In addition, the method of instructing may include implicitly instructing when responding to a TRS or a trigger frame included in a PPDU such as a TRS. Such a limited setting may be a setting that does not require a PE field of a previously set length. In one embodiment, the previously set length may be 20 us or more. More specifically, the previously set length may be 20 us. In another embodiment, the previously 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 a limited 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, the duration of the PE field included in the response PPDU may be 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 an embodiment, when transmitting a TRS or a trigger frame included in a PPDU including a TRS, it is possible to instruct a response 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 is not necessary to instruct a response with 4096-QAM. Alternatively, when transmitting a TRS or a trigger frame included in a PPDU including a TRS, it is possible to instruct a response 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 number of spatial streams not exceeding a preset number, for example, the preset number may be eight.

[0309] Alternatively, when transmitting a trigger frame included in a TRS or a PPDU including a TRS, it may be instructed to respond using a channel width, bandwidth, or RU size equal to or smaller than a previously set size. For example, the previously set size may be 160 MHz or 320 MHz. Or, the previously 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 as described above do not need to be used.

[0311] Referring to FIG. 22, an AP may transmit a frame including a TRS control. Also, a trigger frame may 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, a setting that requires a high capability upon reception may not be indicated. 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 16us or less. Therefore, unnecessary resource consumption due to a long PE field is avoided.

[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 FIG. 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 the PPDU may indicate the duration of the PE field of the PPDU in the PE Duration subfield. For example, the 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 may indicate one of the following values: 0, 4, 8, 12, 16, or 20 us. In this case, the PE duration subfield may be 3 bits. In this case, there is an 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 PE field of 20 us is permitted. In this case, the PE duration subfield may be 1 bit. This method has the advantage that the number of bits of the PE duration subfield included in the TRS is small. 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 permit the use of a PE field of 20 us, the duration indicated by the default PE duration subfield included in the operation element described in FIG. 20 and FIG. 21 may be set as the duration of the PE field and transmitted in the PPDU.

[0317] The duration of the PE field of 20 us may be limited to be used only in the EHT TB PPDU. If a response is made with the 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, the transmission of which is triggered by the TRS or the 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 a TRS control or trigger frame configured to request a PE field of 20 us is included in the PPDU including the TRS control. If it is indicated that a TRS control or trigger frame configured to request a PE field of 20 us is included, a response may be made using a PPDU including a PE field of 20 us. If it is indicated that a TRS control or trigger frame configured to request a PE field of 20 us is not included, the duration of the PE field may be set by 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 of a previously set duration. For example, the previously set duration may be 20us. Also, this embodiment may be limited to a case where a response is made with an EHT TB PPDU. If a response is made with an HE TB PPDU, the PE field of 20us may not be used. That is, when responding with an EHT TB PPDU, a PE field of 20us may be included in the EHT TB PPDU and transmitted, and when responding with an HE TB PPDU, a PE field set by 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 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] FIG. 23(a) is a diagram showing a TRS control field. Referring to FIG. 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 FIG. 18 to FIG. 23. In addition, the PE Duration subfield may indicate whether or not to respond with a PE field of 20 us. 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 a PE duration subfield included in the TRS control field is set to 0, the PE duration subfield set to 0 may indicate that 20us is not used or that a default PE duration is used. In addition, other PE duration subfields included in a PPDU including a PE duration subfield set to 0 may also be set to 0. In addition, a trigger frame included in a PPDU including a PE duration subfield set to 0 may be set such that the duration of a PE field of a PPDU responding to the trigger frame is the same as the duration indicated by the PE duration subfield set to 0. Referring to FIG. 23(b), 1) a PE duration subfield set to 0, or 2) a duration of a 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 including 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 HE 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. The PE duration subfield set to 1 may indicate that 20us is used or that the default PE duration is not used. In addition, other PE duration subfields included in the PPDU including the PE duration subfield set to 1 may also be set to 1. In addition, the trigger frame included in the PPDU including the PE duration subfield set to 1 may be set so that the duration of the PE frame of the PPDU responding to the trigger frame is the same as the duration indicated by the PE duration subfield set to 1. Referring to FIG. 23(b), 1) the PE duration subfield set to 1, or 2) the duration of the PE field included in the PPDU responding to the trigger frame included in the PPDU including the PE duration subfield set to 1 may be 20us. Alternatively, 1) 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 1, or 2) the PE duration subfield set to 1 may not be the default PE duration. In this case, the responding PPDU may be an EHT PPDU. Or, in this case, 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 may be set to 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 format of the indicated PPDU (e.g., whether EHT TB PPDU or 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 above-mentioned specific conditions (e.g., when it is indicated 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 2×996, when the bandwidth in 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 a PPDU, if the maximum value of the duration of the PE field when the PPDU is indicated by the trigger frame and the maximum value of the duration of the PE field when indicated by the TRS are the same, 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 the TRS and the trigger frame are included in one PPDU and both indicate the 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 duration of the PE field indicated by the default PE duration subfield when indicated by the TRS may not be the same. For example, when the TB PPDU indicated by the trigger frame and / or the TRS meets a specific condition, the maximum value of the duration of the PE field may be a first maximum value (e.g., 20us is allowed), and the maximum value of the duration of the PE field indicated by the default PE subfield included in the action element may be a second maximum value (e.g., 16us). 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 may indicate that a maximum value of 20 us is allowed for the duration of the PE field, or may indicate that the duration of the PE field should be set as 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 a PPDU format responding to the TRS. According to an embodiment, when responding to the TRS with an HE PPDU, the duration of the PE field may be the HE default PE duration. Also, when responding to the 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 the HE TB PPDU. Or, the HE PPDU may be the HE SU PPDU. Or, the EHT PPDU may be the EHT TB PPDU. Or, the EHT PPDU may be the 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 20us, 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 20us.

[0336] According to another embodiment, the EHT default PE duration subfield may 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 may be 3 bits.

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

[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. Also, the EHT default PE duration subfield may be included in the 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 a case where an HE PPDU is transmitted in response to a TRS control and a case 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 a value indicated in FIG. 24(a). Also, the default PE duration may be a value of 16us 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 an EHT operation element or an HE operation element. For example, the EHT default PE duration may be set to 1) a value already set based on an EHT default PE duration subfield included in an EHT operation element, or 2) a value based on a default PE duration subfield included in an HE operation element. The already set value may be 20us. 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 A-PPDUs (aggregated PPDUs). 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 constituted of an HE TB PPDU and an EHT TB PPDU may be triggered to transmit 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 of setting the durations may follow the methods described in 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 the TB PPDU can also be transmitted in response to a trigger frame or a TRS. For example, a SU PPDU or a 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, a method of setting the duration of the PE field may be different depending on whether a TB PPDU or a PPDU other than the TB PPDU is transmitted in response to a trigger frame or a TRS. For example, when a TB PPDU is transmitted, the duration setting method described in FIG. 20 to FIG. 24 can be used. Also, 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, it is possible to perform carrier sense (CS) when responding to a trigger frame. For example, when a trigger frame is received, the 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 mean taking NAV into consideration. 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 a trigger frame.

[0347] According to an embodiment of the present invention, there may be signaling instructing to determine whether to respond based on a CS result when responding to a trigger frame. For example, the CS Required subfield included in the trigger frame shown in FIG. 16 may be signaling instructing to determine whether to respond based on a CS result when responding to a trigger frame. For example, when the CS Required subfield is set to 1, it is possible to determine whether to respond based on the CS result when responding to a trigger frame including the CS Required subfield.

[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 may not 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 may 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 be the case that at least one of the physical CS and the virtual CS is busy. When the CS result is idle, it may be the case 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 or not 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 Fig. 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, it is possible to respond to the trigger frame without relying on the CS result. Also, it is possible to respond to the TRS control without relying 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 a response indicated by the trigger frame. The UL Length subfield shown in FIG. 16 may indicate the length of a response indicated by the trigger frame. The length of a TB PPDU responding to the trigger frame may be based on the UL Length subfield value included in the trigger frame. Also, setting the CS Required subfield based on the UL Length subfield may be limited to the case where the trigger frame is of a type that has already been set. The type of the trigger frame may be indicated by the Trigger Type subfield shown in FIG. 16. For example, when 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 previously set value (smaller or equal), the CS Required subfield may be set to 0 or 1. As a more specific embodiment, if the UL length subfield value is less than or equal to a previously set value, the CS Required subfield may be set to 0. Also, if the UL length subfield value exceeds (is greater than) the previously set value, the CS Required subfield may be set to 1. If the UL length subfield value exceeds (is greater than) the previously 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 already set value 418 may be a value corresponding to the PPDU length 584us. Also, 584us may be the maximum TB PPDU duration that can be specified by TRS control. 584us may be the maximum HE TB PPDU duration that can be specified by TRS control. 584us may be the sum of the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, HE-STF, HE-LTF, Data field, and PE field lengths of the TB PPDU. L-STF, L-LTF, L-SIG, and RL-SIG may be 8, 8, 4, and 4us, respectively. HE-SIG-A may be 8us. HE-STF may be 8us for the TB PPDU. HE-LTF is a TB PPDU that responds to TRS control and may be 16us. 4x HE-LTF with a GI (guard interval) of 3.2us may be 16us. The maximum value of the Data field that can be specified by the TRS control may be a 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 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 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 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 be one in which the CS Required subfield is set to 0 according to 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 the TRS control will respond without based on the CS result, and STAs responding to the trigger frame will respond based on the CS result, which may 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 a 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 already set value 76 may be a value corresponding to 128 us, and 128 us may be the duration of an HE TB PPDU having a 4x HE-LTF and a 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 the 6 GHz band. The length of the signal extension may be 6 us in the 2.4 GHz band.

[0369] An example of the setting of the CS Required subfield and the UL MU operation according to one embodiment of the present invention is shown in Fig. 26. In Fig. 26, the same contents as those explained in Figs. 1 to 25 are omitted.

[0370] According to the above embodiment, there may be a case where the trigger frame instructs to respond with an HE TB PPDU and a case where the trigger frame instructs to respond with an EHT TB PPDU, and there may be a case where the TRS control instructs to respond with an HE TB PPDU and a case where the trigger frame instructs to respond 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 the EHT TB PPDU response may be different from the maximum TB PPDU duration that can be indicated by the TRS control field indicating the HE TB PPDU response. For example, the maximum TB PPDU duration that can be indicated by the TRS control field indicating the EHT TB PPDU response may be longer than the maximum TB PPDU duration that can be indicated by the TRS control field indicating the HE TB PPDU response. This is because, as described above, the EHT PPDU may include a PE field of 20us. Or, the length indication method of the TRS control field indicating the EHT TB PPDU response is different from that of the TRS control field indicating the 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 a waste of resources.

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

[0374] At this time, the trigger frame can set the CS Required subfield based on a value based on the maximum EHT TB PPDU length that can be instructed by the TRS control, as described in FIG 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 instructed by the TRS control. Therefore, since the UL Length subfield value included in the trigger frame is larger than the already set value used when setting the CS Required subfield, it is possible to set the CS Required subfield 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 may respond with an EHT TB PPDU regardless of the CS result, and a STA responding to the trigger frame may decide 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 a part of the resources is used to respond to the TRS control, it may be difficult for other STAs to utilize 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 Fig. 27 may be a method for solving the problems described in Fig. 25 and Fig. 26. Also, in the embodiment of Fig. 27, the above-mentioned contents 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 trigger frame indicates by the TRS control included in the same PPDU. According to an embodiment, when the trigger frame or the TRS control solicits the HE TB PPDU, the pre-set value may be threshold 1, and when the trigger frame or the TRS control solicits the EHT TB PPDU, the pre-set value may be threshold 2.

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

[0380] According to an 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 an 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 a TRS control presenting an EHT TB PPDU is greater than the maximum duration of a TB PPDU that can be instructed by a TRS control presenting an HE TB PPDU. For example, threshold 2 may be equal to a length value calculated by substituting the value of Time calculated by Equation 11 into 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. The EHT-STF length may be 8 us.

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

[0385] The data field length may be based on the maximum length that the TRS control presenting the EHT TB PPDU can indicate. For example, the data field length may be based on the maximum number of OFDM symbols that the TRS control presenting the EHT TB PPDU can indicate. The data field length may be based on the maximum number of OFDM symbols that the TRS control presenting the EHT TB PPDU can indicate multiplied by the OFDM symbol length. The data field length may be based on the maximum number of OFDM symbols that the TRS control presenting the EHT TB PPDU can indicate 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 an 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 the implementation of the EHT STA.

[0387] According to another embodiment, the maximum length that the TRS control soliciting the EHT TB PPDU can indicate may be different from the maximum length that the TRS control soliciting the HE TB PPDU can indicate. The maximum length that the TRS control soliciting the EHT TB PPDU can indicate may be different from the maximum number of OFDM symbols that the TRS control soliciting the HE TB PPDU can indicate. 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 the maximum length that can be indicated or the resolution of the length that can be indicated differently from the TRS control soliciting the HE TB PPDU.

[0388] The PE field length may be the maximum PE field length according to one embodiment. The PE field length may be 20 us. According to another embodiment, the PE field length may be a PE field length according to the method described in Figures 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 Figures 22-24. Also, the PE field length may be 20 us when using a PE field of 20 us according to the method described in Figures 22-24.

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

[0390]

number

[0391] Also, in Equation 12, by substituting the Time value into Equation 10, threshold 2 may be 421.

[0392] In conjunction with the embodiment described in FIG. 25, the following is described. A trigger frame presenting an EHT TB PPDU may 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 may set the CS Required subfield to 0 or 1 if the UL length subfield is equal to or less than threshold 2. The threshold 2 may be a value greater than 418. The threshold 2 may be 421. Also, threshold 2 may 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 (for example, a value of 421) may 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 indicating 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 an EHT TB PPDU is indicated under the condition that the pre-set value of 418 is used when an HE TB PPDU is presented, 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 a PE field.

[0398] In conjunction with the embodiment described in FIG. 25, the following is described. A trigger frame presenting an EHT TB PPDU may 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 may set the CS Required subfield to 0 or 1 if the UL length subfield is equal to or less than threshold 2. The threshold 2 may be a value greater than 76. The threshold 2 may be 79. Also, threshold 2 may be used together with the conditions described in FIG. 25. For example, threshold 2 (e.g., a value of 79) may 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 16us 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, it is possible to set the CS Required subfield 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. For this reason, there are cases where the CS Required subfield cannot be set to 0. Thus, in the illustrated embodiment, both STAs responding to the TRS control and STAs responding to the trigger frame are not based on the CS result and are able to 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 20us or less. Also, the trigger frame included in sequence 2 may set the CS Required subfield based on threshold 2. As a more specific example, the trigger frame included in sequence 2 may set the CS Required subfield based on threshold 2 when presenting a TB PPDU response including a PE field of 20us. For example, the trigger frame included in sequence 2 may set the CS Required subfield based on threshold 1 when presenting a TB PPDU response including a PE field of 16us or less. The following may be an example for the case 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. Thus, the CS Required subfield can be set to 0. Thus, when 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. Thus, as described in FIG. 26, 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, thereby solving the problem of resource waste.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. For this reason, the CS Required subfield cannot 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, the threshold 2 may be a value smaller than the threshold 1. In this case, there is an advantage in that it is possible to prevent the CS Required subfield from being set to 1 for a short PPDU or a short frame. For example, when 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, the threshold 2 may be smaller than the threshold 1. For example, when the maximum number of OFDM symbols that can be specified by the TRS control presenting the EHT TB PPDU is 16, the threshold 2 may be equal to a value obtained by substituting the following Time value into Equation 9 or Equation 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 a 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 an A-PPDU (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 an A-PPDU (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 suggesting an EHT TB PPDU transmitted as (or constituting) an A-PPDU, the PE duration of the transmitted PE field may be set to a value of 16us 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 or not, and since 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 FIG. 1 to FIG. 27 may be omitted.

[0415] According to an embodiment of the present invention, a pre-set value used when setting the CS Required subfield based on the UL length subfield described in Figures 25 to 27 may be different depending on whether a trigger frame indicating an 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, a pre-set value used when setting the CS Required subfield based on the UL length subfield may be different depending on whether a PPDU including the trigger frame indicates an EHT TB PPDU includes a frame indicating an HE 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 Fig. 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 Fig. 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 already set value 421 or 79 described in Figs. 25 to 27.

[0417] Also, 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. Or, 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 already 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 already set value as in the case of a trigger frame indicating an HE 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, a PPDU responding to the TRS control indicating an HE TB PPDU and a PE field of a PPDU responding to the TRS control indicating an EHT TB PPDU may have the same duration. The same duration may be 16 us or less. Or, the same duration may be a value indicated by a Default PE Duration subfield included in an HE Operation element.

[0419] Referring to Sequence 2, the trigger frame may solicit the EHT TB PPDU constituting the 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. The 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. The 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. Also, 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 trigger frame indicating the EHT TB PPDU and the trigger frame indicating the HE TB PPDU may set the CS Required subfield to the same value. In addition, when the trigger frame indicating the EHT TB PPDU is transmitted together with the TRS control indicating the 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 may be required in which a response PPDU format is indicated by a frame triggering a PPDU. For example, the PPDU format may refer to a TB PPDU format. The embodiment of FIG. 29 may be a specific embodiment of the above-mentioned TB PPDU format indication method. Also, in this embodiment, the above content may be omitted.

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

[0423] According to an 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 previously set value. For example, the previously set value may be 2007. The previously 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 format different from other User Info fields. That is, the subfields included in the Special User Info field may be different from other User Info fields. The Special User Info field and other User Info fields may commonly include an AID12 subfield at the same position. For example, the first 12 bits of the Special User Info field and other User Info fields may be the AID12 subfield. For example, B0 to B11 of the Special User Info field and other User Info fields may be the AID12 subfield.

[0424] The trigger frame may also include a subfield indicating whether or not the Special User Info field is included. The subfield indicating whether or not the Special User Info field is included may be called 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 in the 802.11ax standard, B55 of the Common Info field is set to 1, which is a previously set value.

[0425] Since the STA receiving the trigger frame can determine whether the Special User Info field is included based on the Special User Info Field Present subfield, it may be easier to implement the determination of whether the Special User Info field is included compared to the case where the Special User Info Field Present subfield does not exist. In addition, when the trigger frame is received by a STA that is not associated with the AP that sent the trigger frame, the AID12 subfield can determine whether the User Info field, which is set to a previously set value indicating the Special User Info field, is a Special User Info field (whether it actually indicates 12 LSBs of AID) based on the Special User Info Field Present subfield. For example, when indicating an RA-RU for an unassociated STA, if the 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. In addition, the STA can perform spatial reuse based on the trigger frame or TB PPDU from a BSS to which the STA is not associated.

[0426] Also, when the trigger frame includes a Special User Info field, the Special User Info field may be located at the very 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, a format of a PPDU responding to a trigger frame can be determined based on whether a trigger frame includes a Special User Info field. For example, if a trigger frame includes a Special User Info field, a format of a PPDU responding to the trigger frame can be EHT TB PPDU. Also, if a trigger frame does not include a Special User Info field, a format of a PPDU responding to the trigger frame can be HE TB PPDU. Also, as described above, a Special User Info Field Present subfield, which is signaling indicating whether a trigger frame includes a Special User Info field, can be present. Therefore, it can be said that a format of a PPDU responding to a trigger frame can be determined based on a Special User Info Field Present subfield. For example, if a Special User Info Field Present subfield is set to 0, a format of a PPDU responding to a trigger frame can be EHT TB PPDU. Also, if a Special User Info Field Present subfield is set to 1, a format of a PPDU responding to a trigger frame can be HE TB PPDU.

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

[0429] When the User Info field is the EHT variant and when it is the HE variant, the RU indication method may be different. For example, the User Info field may be interpreted differently 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 so as 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 so as to indicate an RU supported by the HE standard.

[0430] Also, 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. Also, the RU Allocation subfield may be 8 bits. The PS160 subfield may indicate which subchannel the RU indicated by the RU Allocation subfield is in. Or, the PS160 subfield may indicate which subchannel the RU indicated by the User Info field is in. In this case, the unit for indicating which subchannel may be a 160 MHz subchannel. The PS160 subfield may indicate whether the indicated RU is in 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 the B39 bit of the User Info field. The PS160 subfield may be 1 bit.

[0431] Also, 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 or not 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 is a previously set value, the User Info field may be a Special User Info field. Referring to FIG. 29, the previously set value may be 2007. Also, referring to FIG. 29, the Special User Info field may be present 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 or not 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] Also, according to an additional embodiment, the format of the 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 called the HE / EHT P160 subfield. According to a more specific embodiment, the HE / EHT P160 subfield may indicate the TB PPDU format for a channel that has already been set. For example, the HE / EHT P160 subfield may indicate the TB PPDU format for a primary 160MHz channel (P160 channel). For example, when the HE / EHT P160 subfield value is 1, it may indicate that a response is made with the HE TB PPDU. Also, when the HE / EHT P160 subfield value is 0, it may indicate that a response is made with the 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. When the HE / EHT P160 subfield indicates the EHT TB PPDU, it is possible to respond with the EHT TB PPDU when responding to a trigger frame. That is, when the HE / EHT P160 subfield indicates the EHT TB PPDU, it is possible to respond with the EHT TB PPDU regardless of the assigned RU position when responding to a trigger frame. Also, when the HE / EHT P160 subfield indicates the 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 the HE TB PPDU, the TB PPDU format can be indicated and determined based on the allocated RU position when responding to the trigger frame. If the HE / EHT P160 subfield indicates the HE TB PPDU, and the allocated RU is included in the already set channel (e.g., P160 channel) indicated by the HE / EHT P160 subfield, the response can be made with the HE TB PPDU. Also, if the HE / EHT P160 subfield indicates the HE TB PPDU, and the allocated RU is not included in the already set channel (e.g., P160 channel) indicated by the HE / EHT P160 subfield (e.g., RU allocated to the secondary 160 MHz channel (S160 channel) is included), the response can be made with the EHT TB PPDU. Also, whether or not the allocated RU is included in the already set channel can be 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 based on the PS160 subfield.

[0437] Also, indicating and determining the TB PPDU format based on the HE / EHT P160 subfield and the assigned RU location may be limited to the case where the trigger frame includes the Special User Info field. If the trigger frame includes the Special User Info field, the trigger frame may include the HE / EHT P160 subfield and the PS160 subfield. If the trigger frame does not include the Special User Info field, the trigger frame can always be responded to using the 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 description of the case where the trigger frame includes the Special User Info field and the case where it does not include the Special User Info field may mean the case where the Special User Info Field Present subfield is set to include the Special User Info field and the case where it does not include the Special User Info field, respectively.

[0438] In the present invention, the description of instructing and determining whether to use the EHT TB PPDU when responding to a trigger frame may be replaced with an invention instructing and determining whether to use the EHT TB PPDU or the NEXT TB PPDU. In addition, 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, when 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 the trigger frame. The information required when responding to the trigger frame may include information included in the preamble of the PPDU responding to the trigger frame. For example, the information required when responding to the trigger frame may include information included in the U-SIG field of the 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. Also, the mentioned fields may be present in the mentioned order. Also, the mentioned fields may have the number of bits of 12, 3, 2, 4, 4, 12, 3, and 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 value included in the Special User Info field can be copied to the subfield included in the responding U-SIG field. The subfields copied to the subfield 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] In addition, 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 (see FIG. 16) included in the Common Info field.

[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 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 to be different depending on the format of the PPDU.

[0448] Specifically, it may be set to a value indicated by a PE duration field indicated by a TRS control field, or may be set to a value indicated by a default PE duration subfield included in an action element, or, when a 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 format of the indicated PPDU (e.g., whether an EHT TB PPDU or a HE TB PPDU is indicated)).

[0449] For example, a duration of 20 us may be allowed for the PE field only when the TB PPDU satisfies the above-mentioned specific conditions (e.g., when it is indicated 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 in 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 to 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 a single PPDU and both indicate the transmission of a PPDU, if the maximum value of the duration of the PE field when a PPDU is indicated by the trigger frame and the maximum value of the duration of the PE field when indicated by the TRS are the same, then the duration 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 the TRS and the 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 duration of the PE field indicated by the default PE duration subfield when indicated by the TRS may not be the same. For example, when the TB PPDU indicated by the trigger frame and / or the TRS meets a specific condition, the maximum value of the duration of the PE field may be a first maximum value (e.g., 20us is allowed), and the maximum value of the duration of the PE field indicated by the default PE subfield included in the action element may be a second maximum value (e.g., 16us). In this case, the duration of the PE field may be set to a value indicated by the default PE subfield or a value indicated by the PE subfield included in the TRS.

[0453] In this case, the PE Duration subfield can indicate that 20 us is permitted as the maximum duration of the PE field, 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 a PPDU format responding to the TRS. According to an embodiment, when responding to the TRS with an HE PPDU, the duration of the PE field may be the HE default PE duration. Also, when responding to the 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 the HE TB PPDU. Or, the HE PPDU may be the HE SU PPDU. Or, the EHT PPDU may be the EHT TB PPDU. Or, the EHT PPDU may be the 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 20us, 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 20us.

[0458] 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. According to yet another embodiment, the EHT default PE duration can be 20 us.

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

[0460] In this case, 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.

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

[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 a triggered response scheduling (TRS) for triggering transmission of the PPDU, 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 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 for calculating the duration of the PE field are set so that the duration of the PE field calculated by the plurality of subfields is identical to the duration of the PE field of the PPDU for the other STA.

[0464] The action element includes an EHT default PE duration subfield that indicates 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.

[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, then the duration for the PE field indicated by the EHT Default PE Duration subfield is "20us".

[0466] 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 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 idea or essential features of the present invention. Therefore, the above-described embodiments should be understood as illustrative and not restrictive in all respects. 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 interpreted as being included within the scope of the present invention.

Claims

1. A terminal of a wireless communication system, A 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 AP (Access Point); In response to the frame, a PPDU is transmitted, the PPDU including a packet extension (PE) field for providing a processing time for the PPDU; 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 action element includes a Default PE duration subfield indicating 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 Triggered response scheduling (TRS) for triggering transmission of the PPDU, the format of the PPDU is indicated as an EHT PPDU by the frame, and when a maximum value of the duration indicated by the default PE duration subfield is different from a 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 each value of a plurality of subfields included in the frame used for calculating the duration of the PE field is set so that the duration of the PE field calculated by 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; 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 identical to 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 action element includes a Default PE duration subfield indicating 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 for calculating the duration of the PE field are set so that the duration of the PE field calculated by the plurality of subfields is equal to 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 a PE field of an EHT PPDU is the same as a maximum duration value for a 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 '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.

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