Wireless communication method for supporting a plurality of PPDU formats and wireless communication terminal using the same

Abstract

A station that communicates wirelessly is disclosed. The station includes a transceiver and a processor. The processor receives a triggering frame that triggers the transmission of the station via the transceiver, and based on the type of the triggering frame and the type of a trigger-based (TB) physical layer protocol data unit (PPDU) transmitted as a response to the triggering frame, determines a value of a Length field in a signaling field of the trigger-based PPDU, where the Length field indicates a value used to calculate a duration of the TB PPDU, and transmits the TB PPDU.

Description

Technical Field

[0001] The present invention relates to a wireless communication method that supports multiple PPDU formats and a wireless communication terminal using the same.

Background Art

[0002] In recent years, with the spread of mobile devices, wireless LAN technology that can provide fast wireless Internet services to them has been attracting a great deal of attention. Wireless LAN technology is a technology that enables mobile devices such as smartphones, smart pads, laptop computers, portable multimedia players, and embedded devices to be wirelessly connected to the Internet from home, enterprise, or a specific service-providing area based on wireless communication technology.

[0003] Since IEEE (Institute of Electrical and Electronics Engineers) 802.11 supported the initial wireless LAN technology using the 2.4 GHz frequency, it has been commercializing or developing standards for various technologies. First, IEEE 802.11b supports a communication speed of up to 11 Mbps while using the frequency of the 2.4 GHz band. IEEE 802.11a, which was commercialized after IEEE 802.11b, uses the frequency of the 5 GHz band instead of the 2.4 GHz band, reducing the influence of interference compared to the very congested 2.4 GHz band frequency, and improving the communication speed up to 54 Mbps using OFDM (orthogonal frequency division multiplexing) technology. However, IEEE 802.11a has the disadvantage of a shorter communication distance compared to IEEE 802.11b. And IEEE 802.11g, like IEEE 802.11b, uses the frequency of the 2.4 GHz band to implement a maximum communication speed of 54 Mbps and satisfies backward compatibility, receiving considerable attention, and also having an advantage over IEEE 802.11a in terms of communication distance.

[0004] And there is IEEE 802.11n, a technical standard established to overcome the limitations on communication speed that have been regarded as vulnerabilities in wireless LANs. IEEE 802.11n aims to increase the speed and reliability of the network and extend the operating distance of wireless networks. More specifically, IEEE 802.11n supports a high throughput (HT) with a data processing speed of 540 Mbps or more, and is also based on the MIMO (Multiple Inputs and Multiple Outputs) technology that uses multiple antennas at both ends of the transmitter and receiver to minimize transmission errors and optimize data speed. In addition, this standard enables a coding method that transmits multiple copies of data to enhance data reliability.

[0005] As the popularity of Wi-Fi has been activated and the applications using it have become diversified, there has been an emerging need for a new Wi-Fi system that supports a higher processing rate (Very High Throughput, VHT) compared to the data processing speed supported by IEEE 802.11n. Among these, IEEE 802.11ac supports a wide bandwidth (80 MHz to 160 MHz) at the 5 GHz frequency. Although the IEEE 802.11ac standard is defined only in the 5 GHz band, the initial 11ac chipset will support operation in the 2.4 GHz band for backward compatibility with existing 2.4 GHz band products. Theoretically, according to this standard, the Wi-Fi speed of a multi-station can be at least 1 Gbps, and the maximum single-link speed can be at least 500 Mbps. This is achieved by expanding the wireless interface concepts accepted in 802.11n, such as a wider wireless frequency bandwidth (up to 160 MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high-density modulation (up to 256QAM). Also, there is IEEE 802.11ad, which is a transmission standard that uses beamforming technology to provide a speed of up to 7 Gbps and is suitable for high-bitrate video streaming such as large-capacity data and uncompressed HD videos. However, the 60 GHz frequency band has the disadvantage that it is difficult to pass through obstacles and can only be used between devices in a short-distance space.

[0006] On the other hand, as a Wi-Fi standard after 802.11ac and 802.11ad, the IEEE 802.11ax (High Efficiency WLAN, HEW) standard for providing high-efficiency and high-performance Wi-Fi communication technology in a high-density environment where APs and terminals are concentrated is in the development completion stage. In a Wi-Fi environment based on 802.11ax, it is necessary to provide high-frequency efficiency communication indoors / outdoors in the presence of a high density of stations and APs (Access Points), and various technologies for realizing this have been developed.

[0007] Also, new Wi-Fi standards are being developed to increase the maximum transmission speed to support new multimedia applications such as high-quality videos and real-time games. In the 7th generation Wi-Fi standard, IEEE 802.11be (Extremely High Throughput, EHT), standard development is underway with the goal of supporting a transmission rate of up to 30 Gbps in the 2.4 / 5 / 6 GHz bands through wider bandwidths, increased spatial streams, and multi-AP cooperation.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] An embodiment of the present invention aims to provide a wireless communication method that supports multiple PPDU formats and a wireless communication terminal using the same.

MEANS FOR SOLVING THE PROBLEMS

[0009] A station that communicates wirelessly according to an embodiment of the present invention includes a transceiver and

[0010] a processor. The processor receives a triggering frame that triggers the transmission of the station via the transceiver, and determines a value of a Length field in a signaling field of the TB PPDU based on a type of the triggering frame and a type of a trigger-based (TB) PPDU transmitted as a response to the triggering frame. The Length field indicates a value used to calculate a duration of the TB PPDU, and transmits the TB PPDU.

[0011] When the triggering frame is a trigger frame, the processor sets the value of L_Length of TXVECTOR as the value of the UL Length field of the trigger frame, sets the value obtained based on the value of L_Length according to the format of the TB PPDU as the value of the Length field. When the triggering frame is a frame including a TRS Control field, the value of L_Length is set based on the format of the TB PPDU and a formula specified in advance for each format of the TB PPDU, and the value obtained by adding 2 to the value of L_Length can be set as the value of the Length field.

[0012] When the triggering frame is a frame including a TRS Control field and the format of the TB PPDU is a HE TB PPDU, the value of L_Length is set as the value obtained by a formula specified in advance for the HE TB PPDU. When the triggering frame is a frame including a TRS Control field and the format of the TB PPDU is an EHT TB PPDU, the value of L_Length can be set as the value obtained by subtracting 2 from the value obtained by a formula specified in advance for the EHT TB PPDU.

[0013] The remainder value when the value of the Length field is divided by 3 may be used when distinguishing between the HE TB PPDU and the EHT TB PPDU.

[0014] The formula specified in advance for the EHT TB PPDU may be the following formula.

[0015] Length = ceil( (TXTIME - SignalExtension - 20) / 4 )*3 - 3

[0016] ceil(x) represents the ceiling value of x, SignalExtension represents the length of the signal extension, and TXTIME may be obtained by the following formula.

[0017] TXTIME = 20 + T_EHT_PREAMBLE + N_SYM*T_SYM + T_PE + SignalExtension

[0018] T_EHT_PREAMBLE is the length of the preamble of the EHT TB PPDU excluding L-STF, L-LTF, and L-SIG, N_SYM*T_SYM is the length of the data field of the EHT TB PPDU, N_SYM is the number of data OFDM symbols, T_SYM is the length of one OFDM symbol, and T_PE may be the length of the packet extension field.

[0019] When the processor receives a PPDU (physical layer protocol data unit) via the transceiver, if the PPDU meets the specified conditions, it obtains the value of the PHY Version Identifier field indicating the format of the PPDU from the signaling field of the received PPDU. When the obtained value of the PHY Version Identifier field indicates a PPDU format not supported by the station, the value of FORMAT of the RXVECTOR transmitted to the MAC (medium access control) layer of the station can be set to a specified value.

[0020] When the obtained value of the PHY Version Identifier field indicates a PPDU format supported by the station, the value of FORMAT of the RXVECTOR can be set to a value corresponding to the PPDU format indicated by the obtained value of the PHY Version Identifier field.

[0021] The received PPDU may include a Version Independent field regardless of the value of the PHY Version Identifier field. At this time, when the value of the obtained PHY Version Identifier field indicates a PPDU format not supported by the station, the processor can transmit the information obtained from the Version Independent field to the MAC layer of the station.

[0022] The processor can set CH_BANDWIDTH, UPLINK_FLAG, BSS_COLOR, and TXOP_DURATION of the RXVECTOR based on the information obtained from the Version Independent field. The CH_BANDWIDTH indicates the bandwidth of the received PPDU, the UPLINK_FLAG indicates whether the received PPDU is an uplink PPDU, the BSS_COLOR indicates the BSS color to which the received PPDU belongs, and the TXOP_DURATION can indicate the duration of the TXOP in which the received PPDU was exchanged.

[0023] A method for operating a station that communicates wirelessly according to an embodiment of the present invention includes receiving a triggering frame that triggers transmission of the station, determining a value of a Length field in a signaling field of the trigger-based (TB) PPDU (physical layer protocol data unit) based on a type of the triggering frame and a type of the TB PPDU transmitted as a response to the triggering frame, the Length field indicating a value used to calculate a duration of the TB PPDU, and transmitting the TB PPDU.

[0024] The step of determining the value of the Length field in the signaling field of the TB PPDU includes: when the triggering frame is a trigger frame, setting the value of L_Length in TXVECTOR to the value of the UL Length field of the trigger frame, and setting the value obtained based on the value of L_Length according to the format of the TB PPDU as the value of the Length field; when the triggering frame is a frame including a TRS Control field, setting the value of L_Length based on the format of the TB PPDU and a predefined formula for each format of the TB PPDU, and setting the value obtained by adding 2 to the value of L_Length as the value of the Length field.

[0025] When the triggering frame is a frame including a TRS Control field, the step of setting the value of the Length field includes: when the triggering frame is a frame including a TRS Control field and the format of the TB PPDU is a HE TB PPDU, setting the value of L_Length to the value obtained by a predefined formula for the HE TB PPDU; when the triggering frame is a frame including a TRS Control field and the format of the TB PPDU is an EHT TB PPDU, setting the value of L_Length to the value obtained by subtracting 2 from the value obtained by a predefined formula for the EHT TB PPDU.

[0026] The remainder value when the value of the Length field is divided by 3 may be used to distinguish between the HE TB PPDU and the EHT TB PPDU.

[0027] The predefined formula for the EHT TB PPDU may be the following formula.

[0028] Length = ceil( (TXTIME - SignalExtension - 20) / 4 )*3 - 3

[0029] ceil(x) represents the ceiling value of x, and

[0030] SignalExtension may represent the length of the signal extension.

[0031] TXTIME may be obtained by the following formula.

[0032] TXTIME = 20 + T_EHT_PREAMBLE + N_SYM*T_SYM + T_PE + SignalExtension

[0033] T_EHT_PREAMBLE is the length of the preamble of the EHT TB PPDU excluding L-STF, L-LTF, and L-SIG, N_SYM*T_SYM is the length of the data field of the EHT TB PPDU, N_SYM is the number of data OFDM symbols, T_SYM is the length of one OFDM symbol, and T_PE may be the length of the packet extension field.

[0034] When receiving a PPDU (physical layer protocol data unit) via the transceiver unit, the operation method may further include: when the PPDU meets a predetermined condition, obtaining the value of the PHY Version Identifier field indicating the format of the PPDU from the signaling field of the received PPDU; and when the obtained value of the PHY Version Identifier field indicates a format of the PPDU not supported by the station, setting the value of FORMAT of the RXVECTOR transmitted to the MAC (medium access control) layer of the station to a predetermined value.

[0035] The operation method may further include a step of setting the value of FORMAT in RXVECTOR to a value corresponding to the format of the PPDU indicated by the value of the obtained PHY Version Identifier field when the value of the obtained PHY Version Identifier field indicates the format of the PPDU supported by the station.

[0036] The received PPDU may include a Version Independent field regardless of the value of the PHY Version Identifier field. At this time, the operation method may further include a step of transmitting the information obtained from the Version Independent field to the MAC layer of the station when the value of the obtained PHY Version Identifier field indicates the format of the PPDU not supported by the station.

[0037] The step of transmitting the information obtained from the Version Independent field to the MAC layer of the station may include a step of setting CH_BANDWIDTH, UPLINK_FLAG, BSS_COLOR, and TXOP_DURATION in RXVECTOR based on the information obtained from the Version Independent field. The CH_BANDWIDTH indicates the bandwidth of the received PPDU, the UPLINK_FLAG indicates whether the received PPDU is an uplink PPDU, the BSS_COLOR indicates the BSS color to which the received PPDU belongs, and the TXOP_DURATION can indicate the duration of the TXOP in which the received PPDU was exchanged.

Advantages of the Invention

[0038] An embodiment of the present invention provides a wireless communication method for efficiently supporting a plurality of PPDU formats and a wireless communication terminal using the same.

Brief Description of the Drawings

[0039]

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Mode for Carrying Out the Invention

[0040] The terms used in this specification are, as much as possible, general terms that are currently widely used, considering the functions in the present invention. However, this may vary depending on the intentions, conventions of those skilled in the art, or the emergence of new technologies. Also, in certain cases, there are terms arbitrarily selected by the applicant. In such cases, the meaning is described in the description part of the corresponding invention. Therefore, it is clarified that the terms used in this specification are not just the names of the terms, but should be interpreted based on the substantial meaning the terms have and the content throughout this specification.

[0041] Throughout the specification, if a certain configuration is said to be "connected" to another configuration, this includes not only the case where it is "directly connected", but also the case where it is "electrically connected" with other components interposed in between. Also, if a certain component "includes" a specific component, this means that, unless otherwise stated to the contrary, it may further include other components rather than excluding other components. In addition, the limiting terms "above" or "below" based on a specific threshold value can be appropriately replaced by "exceeding" or "less than" respectively according to the embodiments.

[0042] Hereinafter, in the present invention, a field and a subfield may be used in the same meaning.

[0043] FIG. 1 is a diagram showing a wireless LAN system according to an embodiment of the present invention.

[0044] A wireless LAN system includes one or more Basic Service Sets (BSSs), where a BSS represents a set of devices that have successfully synchronized and can communicate with each other. Generally, BSSs are classified into infrastructure BSSs and Independent BSSs (IBSSs). Figure 1 shows an infrastructure BSS among them.

[0045] As shown in Figure 1, infrastructure BSSs BSS1 and BSS2 include one or more stations STA1, STA2, STA3, STA4, STA5, access points AP-1 and AP-2 which are stations providing a Distribution Service, and a Distribution System (DS) that connects the multiple access points AP-1 and AP-2.

[0046] A station (STA) is any device that includes a Medium Access Control (MAC) compliant with the IEEE 802.11 standard and a Physical Layer interface to the wireless medium. In a broad sense, it includes not only non-access point non-AP stations but also all access points AP. Also, in this specification, the term "terminal" is used to refer to either a non-AP or an AP, or both. A station for wireless communication includes a processor and a communication unit, and may further include a user interface unit, a display unit, etc. depending on the embodiment. The processor generates frames to be transmitted via the wireless network, or processes frames received via the wireless network, and performs various other processes for controlling the station. And the communication unit is functionally connected to the processor and transmits and receives frames via the wireless network for the station. In the present invention, the term "terminal" is used to include user equipment (UE).

[0047] An access point (AP) is an entity that provides a connection to a distribution system DS via a wireless medium for stations associated with itself. In an infrastructure BSS, in principle, communication between non-AP stations is carried out via the AP. However, if a direct link is set up, direct communication is also possible between non-AP stations. On the other hand, in the present invention, the AP is used as a concept including a PCP (Personal BSS Coordination Point), but in a broad sense, it includes concepts such as a centralized controller, a base station (BS), a Node B, a BTS (Base Transceiver System), or a site controller. In the present invention, the AP is also referred to as a base wireless communication terminal, but the base wireless communication terminal is used as a term that includes all of the AP, a base station, an eNB (eNodeB), and a transmission point TP in a broad sense. Moreover, the base wireless communication terminal includes various forms of wireless communication terminals that allocate communication medium resources and perform scheduling in communication with a plurality of wireless communication terminals.

[0048] A plurality of infrastructure BSSs are connected to each other via a distribution system DS. At this time, a plurality of BSSs connected via the distribution system are called an Extended Service Set (ESS).

[0049] FIG. 2 is a diagram showing an independent BSS which is a wireless LAN system according to another embodiment of the present invention. In the embodiment of FIG. 2, parts that are the same as or corresponding to those in the embodiment of FIG. 1 are not described repeatedly.

[0050] Since the BSS3 shown in FIG. 2 is an independent BSS and does not include an AP, all stations (STA6, STA7) are not connected to the AP. An independent BSS does not allow connection to a distribution system and forms a self - contained network. In an independent BSS, each station (STA6, STA7) is directly connected to each other.

[0051] FIG. 3 is a block diagram showing the configuration of a station 100 according to an embodiment of the present invention. As shown, the station 100 according to an 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.

[0052] First, the communication unit 120 transmits and receives wireless signals such as wireless LAN packets and may be incorporated into or externally attached to the station 100. According to an embodiment, the communication unit 120 may include at least one communication module using different frequency bands. For example, the communication unit 120 may include communication modules for different frequency bands such as 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz. According to one embodiment, the station 100 can be provided with 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 can 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 can operate only one communication module at a time or operate a plurality of communication modules together according to the performance and requirements of the station 100. When the station 100 includes a plurality of communication modules, each communication module may be provided in an independent form, or a plurality of modules may be integrated as one chip. In an embodiment of the present invention, the communication unit 120 can represent an RF (Radio Frequency) communication module that processes RF signals.

[0053] Next, the user interface 140 includes various forms 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 the instructions of the processor 110 using various output means.

[0054] Next, the display unit 150 outputs an image on the display screen. The display unit 150 outputs various display objects such as content performed by the processor 110 or a user interface based on the control instructions of the processor 110. Also, the memory 160 stores control programs used in the station 100 and various data thereby. Such control programs include connection programs necessary for the station 100 to connect to an AP or an external station.

[0055] The processor 110 of the present invention executes various instructions or programs and processes data within the station 100. Further, the processor 110 controls each unit of the station 100 described above and controls the transmission and reception of data between the units. According to an embodiment of the present invention, the processor 110 executes a program for connection with the AP stored in the memory 160 and receives a communication setting message transmitted by the AP. Further, the processor 110 reads information regarding the priority conditions of the station 100 included in the communication setting message and requests a connection regarding the AP based on the information regarding the priority conditions of the station 100. The processor 110 of the present invention may refer to the main control unit of the station 100, or may refer to a control unit for individually controlling some configurations of the station 100, for example, the communication unit 120, etc. according to an embodiment. That is, the processor 110 may be a modem, or a modulator and / or demodulator, which demodulates and modulates the radio signal transmitted and received from the communication unit 120. The processor 110 controls various operations of the radio signal transmission and reception of the station 100 according to an embodiment of the present invention. Detailed embodiments thereof will be described later.

[0056] The station 100 shown in FIG. 3 is a block diagram according to an embodiment of the present invention, and the separately shown blocks logically distinguish the elements of the device. Therefore, the above-described elements of the device are attached to one chip or a plurality of chips according to the design of the device. For example, the processor 110 and the communication unit 120 may be integrated and implemented on one chip, or may be implemented on separate chips. Further, in an embodiment of the present invention, some configurations of the station 100, for example, the user interface unit 140 and the display unit 150, etc. may be selectively provided in the station 100.

[0057] FIG. 4 is a block diagram showing the configuration of the AP200 according to an embodiment of the present invention. As shown, the AP200 according to the embodiment of the present invention includes a processor 210, a communication unit 220, and a memory 260. In FIG. 4, redundant descriptions are omitted for the parts of the configuration of the AP200 that are the same as or correspond to the configuration of the station 100 in FIG. 3.

[0058] 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 can be provided with 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 can be provided with 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 can perform wireless communication with a station based on the wireless LAN standard of the frequency band supported by the communication module. The communication unit 220 can operate only one communication module at a time or operate a plurality of communication modules simultaneously according to the performance and requirements of the AP 200. In the embodiment of the present invention, the communication unit 220 can represent an RF (Radio Frequency) communication module that processes RF (Radio Frequency) signals.

[0059] Next, the memory 260 stores the control program used in the AP200 and various data thereby. Such a control program includes a connection program for managing the connection of the stations. Further, the processor 210 controls each unit of the AP200 and controls the transmission and reception of data between the units. According to an embodiment of the present invention, the processor 210 executes a program for connection to the stations stored in the memory 260 and transmits a communication setting message for one or more stations. At this time, the communication setting message includes information regarding the connection priority condition of each station. Further, the processor 210 performs connection setting in response to a connection request from the station. According to one embodiment, the processor 210 is a modem or a modulation / demodulation unit that modulates and demodulates the radio signal transmitted and received by the communication unit 220. The processor 210 controls various operations of radio signal transmission and reception of the AP200 according to an embodiment of the present invention. Detailed embodiments thereof will be described later.

[0060] FIG. 5 is a diagram schematically showing the process in which the STA sets a link with the AP.

[0061] Referring to FIG. 5, the link between the STA100 and the AP200 is set through three major steps of scanning, authentication, and association. First, the scanning step is a step in which the STA100 obtains the connection information of the BSS operated by the AP200. As a method for performing scanning, there are a passive scanning method in which information is obtained by utilizing only the beacon message S101 periodically transmitted by the AP200, and an active scanning method in which the STA100 transmits a probe request to the AP at S103, receives a probe response from the AP at S105, and obtains connection information.

[0062] The STA100 that has successfully received the wireless connection information in the scanning step transmits an authentication request (S107a), receives an authentication response from the AP200 (S107b), and performs an authentication step. After the authentication step is performed, the STA100 transmits an association request (S109a), receives an association response from the AP200 (S109b), and performs an association step. In this specification, "association" basically means a wireless connection, but the present invention is not limited thereto, and in a broad sense, "association" includes both wireless connections and wired connections.

[0063] On the other hand, an additional 802.1X-based authentication step S111 and an IP address acquisition step S113 via DHCP are performed. In FIG. 5, the server 300 is a server that processes 802.1X-based authentication between the STA100 and the AP200, and may be physically connected to the AP200 or exist as a separate server.

[0064] FIG. 6 is a diagram showing the CSMA (Carrier Sense Multiple Access) / CA (Collision Avoidance) method used in wireless LAN communication.

[0065] A terminal performing wireless LAN communication checks whether a channel is busy by performing carrier sensing before transmitting data. If a wireless signal with a certain intensity or higher is detected, the channel is determined to be busy, and the terminal delays access to the channel. Such a process is called Clear Channel Assessment (CCA), and the level for determining the presence or absence of signal detection is called the CCA threshold. If a wireless signal equal to or higher than the CCA threshold received by the terminal has the terminal as the recipient, the terminal processes the received wireless signal. On the other hand, if no wireless signal is detected from the channel or a wireless signal with an intensity smaller than the CCA threshold is detected, the channel is determined to be idle.

[0066] If the channel is determined to be idle, each terminal with data to transmit performs a backoff procedure after an IFS (Inter Frame Space) according to the situation of each terminal, such as AIFS (Arbitration IFS), PIFS (PCF IFS), etc. According to an embodiment, the AIFS is used as a configuration to replace the conventional DIFS (DCF IFS). Each terminal waits while reducing the slot time by the random number determined for the terminal during the idle interval of the channel. The terminal that has exhausted all slot times attempts to access the channel. Thus, the section where each terminal performs the backoff procedure is called the contention window section. At this time, the random number can be called a backoff counter. That is, the initial value of the backoff counter is set by the integer that is the random number obtained by the terminal. When the terminal senses that the channel is idle during the slot time, the terminal can decrement the backoff counter by 1. Also, when the backoff counter reaches 0, the terminal may be permitted to perform channel access on the channel. Therefore, the transmission of the terminal may be permitted when the channel is idle during the AIFS time and the slot time of the backoff counter.

[0067] If a specific terminal successfully accesses the channel, the terminal transmits data via the channel. However, if a terminal attempting access collides with another terminal, the colliding terminals are each assigned a new random number and perform a further backoff procedure. According to one embodiment, the new random number newly assigned to each terminal is determined within a range (2*CW) that is twice the range (competition window, CW) of the random number previously assigned to the terminal. On the other hand, each terminal performs a further backoff procedure in the next competition window interval to attempt access, and at this time, each terminal performs the backoff procedure from the slot time remaining in the previous competition window interval. In this way, each terminal performing wireless LAN communication can avoid mutual collisions with respect to a specific channel.

[0068] <Examples of various PPDU formats>

[0069] 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 the detailed field configurations of L-SIG and RL-SIG commonly used in the PPDU formats.

[0070] Referring to FIG. 7(a), the preamble of the legacy PPDU includes an L-STF (Legacy Short Training field), an L-LTF (Legacy Long Training field), and an L-SIG (Legacy Signal field). In an embodiment of the present invention, the L-STF, L-LTF, and L-SIG can be referred to as a legacy preamble.

[0071] Referring to FIG. 7(b), the preamble of the HE PPDU further includes RL-SIG (Repeated Legacy Short Training field), HE-SIG-A (High Efficiency Signal A field), HE-SIG-B (High Efficiency Signal B field), HE-STF (High Efficiency Short Training field), and 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 the HE preamble. The specific configuration of the HE preamble may be modified according to the HE PPDU format. For example, HE-SIG-B may be used only in the HE MU PPDU format.

[0072] Referring to FIG. 7(c), the preamble of the EHT PPDU further includes RL-SIG (Repeated Legacy Short Training field), U-SIG (Universal Signal field), EHT-SIG-A (Extremely High Throughput Signal A field), EHT-SIG-A (Extremely High Throughput Signal B field), EHT-STF (Extremely High Throughput Short Training field), and 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 referred to as the 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 of the EHT PPDU formats.

[0073] The L-SIG field included in the preamble of the PPDU is applied with 64 FFT OFDM and consists of a total of 64 subcarriers. Among these, 48 subcarriers excluding the guard subcarriers, DC subcarriers, and pilot subcarriers are used for transmitting the data of L-SIG. Since BPSK and MCS (Modulation and Coding Scheme) with Rate = 1 / 2 are applied to L-SIG, it may contain a total of 24 bits of information. Fig. 7(d) shows the 24-bit information configuration of L-SIG.

[0074] Referring to Fig. 7(d), 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 value among the transmission speeds of 6 / 9 / 12 / 18 / 24 / 36 / 48 / 54 Mbps, which is a combination of modulation methods such as BPSK / QPSK / 16-QAM / 64-QAM and coding rates such as 1 / 2, 2 / 3, 3 / 4. Combining the information of the L_RATE field and the L_LENGTH field can indicate the total length of the PPDU. In the non-legacy PPDU format, the L_RATE field is set to the minimum speed of 6 Mbps.

[0075] The unit of the L_LENGTH field is byte, and a total of 12 bits are allocated, enabling signaling up to 4095. Combining with the L_RATE field can indicate the length of the PPDU. At this time, legacy terminals and non-legacy terminals can analyze the L_LENGTH field in different ways.

[0076] First, the method by which a legacy terminal or a non-legacy terminal analyzes the length of the PPDU using the L_LENGTH field is as follows. When the L_RATE field is set to 6 Mbps, 3 bytes (i.e., 24 bits) may be transmitted in a symbol duration of 4 us for 64 FFT. Therefore, adding 3 bytes corresponding to the SVC field and the Tail field to the L_LENGTH field value and dividing this by 3 bytes, which is the transmission amount of one symbol, the number of 64 FFT reference symbols after L-SIG is obtained. After multiplying the obtained number of symbols by 4 us, which is the symbol duration of one symbol, and adding 20 us required for transmitting L-STF, L-LTF, and L-SIG, the length of the PPDU, i.e., the reception time (RXTIME), is obtained. Expressing this in a mathematical formula is as shown in Equation 1 below.

[0077]

Number

[0078] At this time,

Number

[0079]

Number

[0080] Here, TXTIME is the total transmission time that constitutes the PPDU and is as shown in Equation 3 below. At this time, TX represents the transmission time of X.

[0081]

Number

[0082] Referring to the above formula, the length of the PPDU is calculated based on the ceiling value of L_LENGTH / 3. Therefore, for any k value, three different values of L_LENGTH = {3k + 1, 3k + 2, 3(k + 1)} indicate the same PPDU length.

[0083] Referring to Fig. 7(e), the U-SIG (Universal SIG) field persists in EHT PPDUs and PPDUs of subsequent generations of wireless LANs and serves to distinguish which generation of PPDU it is, including 11be. U-SIG is 2 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.

[0084] The VI bits continue to maintain the current bit configuration in the future, and even if subsequent generations of PPDUs are defined, current 11be terminals can obtain information about the PPDU from the VI field of the PPDU. For this purpose, the VI field is composed of a PHY version, UL / DL, BSS color, TXOP, and Reserved fields. The PHY version field is 3 bits and serves to sequentially distinguish the 11be and subsequent generations of wireless LAN standards by version. 11be has a value of 000b. The UL / DL field distinguishes whether the PPDU is an uplink / downlink PPDU. The BSS color means the BSS identifier defined in 11ax and has a value of 6 bits or more. The TXOP means the transmit opportunity duration transmitted in the MAC header, but by adding it to the PHY header, the length of the TXOP included in the PPDU can be inferred without decoding the MPDU and has a value of 7 bits or more.

[0085] The VD field may be composed of signaling information that is only useful for PPDUs in the 11be version, fields that are commonly used in any PPDU format such as PPDU format and BW, and fields that are defined differently for each PPDU format. The PPDU format is a discriminator that distinguishes between EHT SU (Single User), EHT MU (Multiple User), EHT TB (Trigger-based), EHT ER (Extended Range) PPDUs, etc. The BW field mainly signals five basic PPDU BW options of 20, 40, 80, 160 (80 + 80), 320 (160 + 160) MHz (BW that can be expressed in the form of 20 times a power of 2 can be called the basic BW), and various remaining PPDU BWs formed by preamble puncturing. Also, after being signaled at 320 MHz, some 80 MHz may be signaled in a punctured form. Also, the channel form that has been punctured and deformed may be directly signaled in the BW field, or may be signaled using both the BW field and fields that appear after the BW field (for example, fields within the EHT-SIG field). If the BW field is 3 bits, a total of 8 BW signalings are possible, so the puncturing mode can signal a maximum of 3. If the BW field is 4 bits, a total of 16 BW signalings are possible, so the puncturing mode can signal a maximum of 11.

[0086] The fields located after the BW field differ depending on the form and format of the PPDU. The MU PPDU and the SU PPDU may be signaled in the same PPDU format. Before the EHT-SIG field, a field for distinguishing between the MU PPDU and the SU PPDU may be located, and additional signaling may be performed therefor. Both the SU PPDU and the MU PPDU include the EHT-SIG field, but some fields unnecessary for the SU PPDU may be compressed. At this time, the information of the fields to which compression is applied may be omitted or may have a size smaller than the size of the original fields included in the MU PPDU. For example, in the case of the SU PPDU, the common fields of the EHT-SIG may be omitted or replaced, the user-specific fields may be replaced, or it may have different configurations such as being reduced to one.

[0087] Alternatively, the SU PPDU may further include a compression field indicating whether it is compressed, and some fields (e.g., the RA field, etc.) may be omitted depending on the value of the compression field.

[0088] 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 with the uncompressed fields (e.g., common fields, 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 obligatorily after the U-SIG field, and the amount of information to be signaled may be variable. That is, since multiple MU PPDUs are transmitted to multiple STAs, each STA must recognize the position of the RU to which the MU PPDU is transmitted, the STA to which each RU is assigned, and whether the transmitted MU PPDU is transmitted to itself. Therefore, the AP must transmit the above information included in the EHT-SIG field. For this purpose, 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 the MCS which is the modulation method. The EHT-SIG field may include the size and position information of the RU assigned to each user.

[0089] In the case of the SU PPDU, multiple RUs may be assigned to the STA, and the multiple RUs may be consecutive or non-consecutive. When the RUs assigned to the STA are not consecutive, the STA can efficiently receive the SU PPDU only by recognizing the RUs punctured in the middle. Therefore, the AP can transmit the SU PPDU including information on the punctured RUs among the RUs assigned to the STA (e.g., the RU puncturing pattern, etc.). That is, in the case of the SU PPDU, a puncturing mode field including information indicating whether the puncturing mode is applied and the puncturing pattern in a bitmap format, etc. may be included in the EHT-SIG field, and the puncturing mode field can signal the form of the discontinuous channels appearing within the bandwidth.

[0090] The form of the discontinuous channel to be signaled is restricted and indicates the BW of the SU PPDU and the discontinuous channel information in combination with the value of the BW field. For example, in the case of an SU PPDU, which is a PPDU transmitted only to a single terminal, the STA can recognize the bandwidth assigned to itself from the BW field included in the PPDU, and can recognize the punctured resources among the assigned bandwidths from the puncturing mode field of the U-SIG field or EHT-SIG field included in the PPDU. In this case, the terminal can receive the PPDU with the remaining resource units other than the specific channels of the punctured resource units. At this time, the plurality of RUs assigned to the STA may be composed of different frequency bands or tones from each other.

[0091] The reason why only the restricted form of the discontinuous channel form is signaled is to reduce the signaling overhead of the SU PPDU. Since puncturing may be performed for each 20 MHz subchannel, when puncturing is performed for a BW having a plurality of 20 MHz subchannels such as 80, 160, and 320 MHz, in the case of 320 MHz, it is necessary to signal the form of the discontinuous channel (including the case where only the end 20 MHz is punctured) by expressing the availability of each of the remaining 15 20 MHz subchannels other than the primary channel. Using 15 bits to signal the discontinuous channel form of single-user transmission can result in excessive signaling overhead when considering the low transmission rate of the signaling part.

[0092] The present invention proposes a method for signaling the discontinuous channel form of an SU PPDU and illustrates the discontinuous channel form determined by the proposed method. In addition, a method for signaling the puncturing forms of the primary 160 MHz and secondary 160 MHz in the 320 MHz BW configuration of the SU PPDU is proposed.

[0093] Also, 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 varied according to the signalized PPDU format in the PPDU format field. Assuming that the BW field is 4 bits, in the case of an EHT SU PPDU or a TB PPDU, since it is not necessary to further signal an EHT-SIG-A of 1 symbol after U-SIG or to signal an EHT-SIG-A from the beginning, considering this, it is necessary to completely signal up to 11 puncturing modes using only the BW field of U-SIG. However, in the case of an EHT MU PPDU, since an EHT-SIG-B is further signaled after U-SIG, up to 11 puncturing modes can be signaled in a different way 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 20 MHz or 10 MHz band. The detailed puncturing pattern for each PPDU type will be described in detail later with reference to FIGS. 11 and 12.

[0094] FIG. 7(f) shows the configuration of the format-specific field of the VD field when indicated as an EHT MU PPDU in the PPDU format field of U-SIG. In the case of an MU PPDU, a SIG-B, which is a signaling field for simultaneous reception by multiple users, is essential, and SIG-B may be transmitted without a separate SIG-A after U-SIG. Therefore, U-SIG must signal information for decoding SIG-B. Such fields include the SIG-B MCS, SIG-B DCM, number of SIG-B symbols, SIG-B compression, number of EHT-LTF symbols field, etc.

[0095] FIG. 8 shows an example of various EHT (Extremely High Throughput) PPDU (Physical Protocol Data Unit) formats according to an embodiment of the present invention and a method for instructing the same.

[0096] Referring to FIG. 8, the PPDU may be composed of a preamble and a data part, and the format of one type of EHT PPDU may be distinguished by the U-SIG field included in the preamble. Specifically, based on the PPDU format field included in the U-SIG field, whether the format of the PPDU is an EHT PPDU may be indicated.

[0097] FIG. 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.

[0098] FIG. 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 a response to the trigger frame. Different from the EHT SU PPDU, the EHT-SIG-A field is not located after the U-SIG field in the EHT PPDU.

[0099] FIG. 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 for transmitting a PPDU to one or more STAs. The EHT MU PPDU format may have an HE-SIG-B field located after the U-SIG field.

[0100] (d) of FIG. 8 shows an example of the EHT ER SU PPDU format used for single-user transmission with STAs in an extended range. The EHT ER SU PPDU may be used for single-user transmission with a wider range of STAs than the EHT SU PPDU described in (a) of FIG. 8, and the U-SIG field may be repeatedly positioned on the time axis.

[0101] The EHT MU PPDU described in (c) of FIG. 8 can be used by the AP for downlink transmission to multiple STAs. At this time, the EHT MU PPDU may include scheduling information so that multiple STAs can receive the PPDU transmitted from the AP simultaneously. The EHT MU PPDU can transmit the AID information of the recipient and / or transmitter of the PPDU transmitted through the user specific field of the EHT-SIG-B to the STA. Therefore, multiple terminals that have received the EHT MU PPDU can perform a spatial reuse operation based on the AID information in the user specific field included in the preamble of the received PPDU.

[0102] Specifically, the resource unit allocation (RA) field of the HE-SIG-B field included in the HE MU PPDU may include information regarding the configuration of resource units (e.g., the division form of resource units) in a specific bandwidth (e.g., 20 MHz, etc.) on the frequency axis. That is, the RA field can indicate the configuration of resource units divided by the bandwidth for the transmission of the HE MU PPDU for the STA to receive the PPDU. The information of the STA assigned (or designated) to each divided resource unit may be included in the 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.

[0103] For example, among a plurality of divided resource units, a user field corresponding to at least one resource unit used for data transmission may include the AID of the recipient or the sender, and a user field corresponding to the remaining resource units not used for data transmission may include a pre-set Null STA ID.

[0104] For the sake of convenience of explanation, in this specification, a frame or a MAC frame may be used in the same meaning as an MPDU.

[0105] When a wireless communication device communicates using a plurality of links, the communication efficiency of the wireless communication device can be improved. At this time, a link is a physical path and may be configured as one wireless medium available for transmitting an MSDU (MAC service data unit). For example, when the frequency band of any one link is being used by another wireless communication device, the wireless communication device can continue to communicate on other links. In this way, the wireless communication device can usefully use a plurality of channels. Also, when the wireless communication device communicates simultaneously using a plurality of links, the overall throughput can be increased. However, existing wireless LANs are defined on the premise that one wireless communication device uses one link. Therefore, a wireless LAN operation method for using a plurality of links is required. With reference to FIGS. 9 to 26, a wireless communication method of a wireless communication device using a plurality of links will be described. First, with reference to FIG. 9, a specific form of a wireless communication device using a plurality of links will be described.

[0106] FIG. 9 shows a multi-link device according to an embodiment of the present invention.

[0107] A multi-link device (MLD) may be defined for the wireless communication method using the plurality of links described above. The multi-link device may represent a device having one or more affiliated stations. According to a specific embodiment, the multi-link device may represent a device having two or more affiliated stations. Also, the multi-link device may exchange multi-link elements. The multi-link element may include information regarding one or more stations or one or more links. The multi-link element may include a multi-link setup element described later. At this time, the multi-link device may be a logical entity. Specifically, the multi-link device may have a plurality of affiliated stations. The multi-link device may be referred to as an MLLE (multi-link logical entity) or an MLE (multi-link entity). The multi-link device may have one MAC service access point (medium access control service access point, SAP) up to the logical link control (LLC). Also, the MLD may have one MAC data service.

[0108] The plurality of stations included in the multi-link device can operate on a plurality of links. Also, the plurality of stations included in the multi-link device can operate on a plurality of channels. Specifically, the plurality of stations included in the multi-link device can operate on different plural links or different plural channels. For example, the plurality of stations included in the multi-link device can operate on different plural channels of 2.4 GHz, 5 GHz, and 6 GHz.

[0109] The operation of the multi-link device can be referred to as multi-link operation, MLD operation, or multi-band operation. Also, when the station associated with the multi-link device is an AP, the multi-link device can be referred to as an AP MLD. Further, when the station associated with the multi-link device is a non-AP station, the multi-link device can be referred to as a non-AP MLD.

[0110] FIG. 9 shows the operation in which a non-AP MLD and an AP-MLD communicate. Specifically, the non-AP MLD and the AP-MLD communicate using three links each. The AP MLD includes a first AP (AP1), a second AP (AP2), and a third AP (AP3). The non-AP MLD includes a first non-AP STA (non-AP STA1), a second non-AP STA (non-AP STA2), and a third non-AP STA (non-AP STA3). The first AP (AP1) and the first non-AP STA (non-AP STA1) communicate through a first link (Link1). Also, the second AP (AP2) and the second non-AP STA (non-AP STA2) communicate through a second link (Link2). Also, the third AP (AP3) and the third non-AP STA (non-AP STA3) communicate through a third link (Link3).

[0111] Multi-link operation may include a multi-link setup operation. The multi-link setup corresponds to the association operation of the single-link operation described above and needs to precede frame exchange in the multi-link. The multi-link device can obtain the information necessary for the multi-link setup from the multi-link setup element. Specifically, the multi-link setup element may include capability information related to the multi-link. At this time, the capability information may include information indicating whether any one of the plurality of devices included in the multi-link device can perform transmission while another device can perform reception. Further, the capability information may include information regarding the links available to each station included in the MLD. Further, the capability information may include information regarding the channels available to each station included in the MLD.

[0112] The multi-link setup may be set by negotiation between peer stations. Specifically, the multi-link setup may be performed by communication between stations without communication with the AP. Also, the multi-link setup may be set through any one link. For example, even when the first to third links are set through the multi-link, the multi-link setup may be performed through the first link.

[0113] Also, the mapping between a TID (traffic identifier) and a link may be set. Specifically, frames corresponding to a specific value of the TID may be exchanged only through a pre-specified link. The mapping between the TID and the link may be set in a directional-based manner. For example, when a plurality of links are set between a first multi-link device and a second multi-link device, the first multi-link device may be set to transmit frames of a first TID to a plurality of first links, and the second multi-link device may be set to transmit frames of a second TID to the first link. Also, there may be a basic setting for the mapping between the TID and the link. Specifically, when there is no additional setting in the multi-link setting, the multi-link device can exchange frames corresponding to the TID on each link according to the basic (default) setting. At this time, the basic setting may be such that all TIDs are exchanged on any one link.

[0114] Specifically describe the TID. The TID is an ID for classifying traffic and data to support QoS (quality of service). Also, the TID may be allocated and used in a layer higher than the MAC layer. Also, the TID can indicate a traffic category (TC) and a traffic stream (TS). Also, the TID may be distinguished into 16. For example, the TID may be designated as any one of 0 to 15. It may be specified that the TID values used are different depending on the access policy, channel access, or medium access method. For example, when EDCA (enhanced distributed channel access) or HCAF (hybrid coordination function contention based channel access) is used, the value of the TID may be allocated in the range of 0 to 7. When EDCA is used, the TID can indicate the user priority (UP). At this time, the UP may be specified by the TC or TS. The UP may be allocated in a layer higher than the MAC. Also, when HCCA (HCF controlled channel access) or SPCA is used, the value of the TID may be allocated in the range of 8 to 15. When HCCA or SPCA is used, the TID can indicate the TSID. Also, when HEMM or SEMM is used, the value of the TID may be allocated in the range of 8 to 15. When HEMM or SEMM is used, the TID can indicate the TSID.

[0115] UP and AC (access category) may be mapped. AC may be a label for providing QoS in EDCA. AC may be a label for indicating an EDCA parameter set. The EDCA parameter or EDCA parameter set is a parameter used in the channel contention of EDCA. The QoS station can guarantee QoS using AC. Also, AC may include AC_BK, AC_BE, AC_VI, and AC_VO. Each of AC_BK, AC_BE, AC_VI, and AC_VO can indicate background, best effort, video, and voice. Also, AC_BK, AC_BE, AC_VI, and AC_VO may be classified into lower-level ACs. For example, AC_VI can be subdivided into AC_VI primary and AC_VI alternate. Also, AC_VO can be subdivided into AC_VO primary and AC_VO alternate. Also, UP or TID may be mapped to AC. For example, each of 1, 2, 0, 3, 4, 5, 6, 7 in UP or TID may be mapped to each of AC_BK, AC_BK, AC_BE, AC_BE, AC_VI, AC_VI, AC_VO, AC_VO. Also, each of 1, 2, 0, 3, 4, 5, 6, and 7 in UP or TID may be mapped to each of AC_BK, AC_BK, AC_BE, AC_BE, AC_VI alternate, AC_VI primary, AC_VO primary, AC_VO alternate. Also, 1, 2, 0, 3, 4, 5, 6, and 7 in UP or TID may be in descending order of priority. That is, 1 may have a lower priority and 7 may have a higher priority. Therefore, the priority may increase in the order of AC_BK, AC_BE, AC_VI, AC_VO. Also, each of AC_BK, AC_BE, AC_VI, AC_VO may correspond to each of ACI (AC index) 0, 1, 2, 3. Due to the characteristics of such TID, the mapping between TID and the link can represent the mapping between AC and the link.Also, the mapping between the link and the AC can represent the mapping between the TID and the link.

[0116] As described above, a TID may be mapped to each of a plurality of links. The mapping may be such that a link through which traffic corresponding to a specific TID or AC can be exchanged is specified. Also, a TID or AC that can be transmitted in the link for each transmission direction may be specified. As described above, there may be a basic setting for the mapping between the TID and the link. Specifically, when there is no additional setting in the multi-link setting, the multi-link device can exchange frames corresponding to the TID on each link according to the basic (default) setting. At this time, the basic setting may be such that all TIDs are exchanged on any one link. Always, at a certain point in time, any TID or AC may be mapped to at least one link. The management frame and the control frame may be transmitted on all links.

[0117] When a link is mapped to a TID or AC, only the data frame corresponding to the TID or AC mapped to the link on that link may be transmitted. Therefore, when a link is mapped to a TID or AC, a frame that does not correspond to the TID or AC not mapped to the link on that link may not be transmitted. When a link is mapped to a TID or AC, the ACK may also be transmitted based on the link to which the TID or AC is mapped. For example, the block ACK agreement may be determined based on the mapping between the TID and the link. In yet another specific embodiment, the mapping between the TID and the link may be determined based on the block ACK agreement. Specifically, a block ACK agreement may be set for the TID mapped to a specific link.

[0118] By the mapping between the TID and the link described above, QoS may be guaranteed. Specifically, a relatively small number of stations may operate, or a high-priority AC or TID may be mapped to a link with a good channel state. Also, by the mapping between the TID and the link described above, a station can be made to maintain a power-saving state for a longer time.

[0119] FIG. 10 is a diagram showing an example of a TID-to-link mapping method according to an embodiment of the present invention.

[0120] Referring to FIG. 10, there may be a mapping relationship between the TID and the link as described in FIG. 9. Also, in the present invention, the mapping relationship between the TID and the link can be referred to as TID-to-link mapping, TID-to-link mapping, TID mapping, link mapping, etc. The TID may be a traffic identifier. Also, the TID may be an ID (identifier) for classifying traffic, data, etc. to support QoS (quality of service).

[0121] Also, the TID may be an ID used or assigned at a layer higher than the MAC layer. The TID can indicate TC (traffic categories) and TS (traffic streams). Also, 16 values are possible for the TID, and for example, it may be indicated by values from 0 to 15. Also, individual TID values can be used according to an access policy or a channel connection and medium access method. For example, when using EDCA (HCF (hybrid coordination function)-based channel connection, extended distributed channel connection), the possible TID values may be from 0 to 7. Also, when using EDCA, 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 to a layer higher than the MAC layer. Also, when using HCCA (HCF controlled channel access) or SPCA, the possible TID values may be from 8 to 15. Also, when using HCCA or SPCA, the TID may indicate the TSID. Also, when using HEMM or SEMM, the possible TID values may be from 8 to 15. Also, when using HEMM or SEMM, the TID may indicate the TSID.

[0122] Also, there may be a mapping relationship between the UP and the access category (AC). The 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 connection. The AC may be used in a QoS STA.

[0123] 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 respectively indicate background, best effort, video, and voice. Also, it is possible to subdivide AC_BK, AC_BE, AC_VI, and AC_VO. For example, AC_VI may be subdivided into AC_VI primary and AC_VI alternate. Also, AC_VO may be subdivided into AC_VO primary and AC_VO alternate. Also, the UP value or the TID value may be mapped to the AC value. For example, the UP value or the TID values 1, 2, 0, 3, 4, 5, 6, 7 may be respectively mapped to AC_BK, AC_BK, AC_BE, AC_BE, AC_VI, AC_VI, AC_VO, AC_VO. Or, the UP value or the TID values 1, 2, 0, 3, 4, 5, 6, 7 may be respectively mapped to AC_BK, AC_BK, AC_BE, AC_BE, AC_VI alternate, AC_VI primary, AC_VO primary, AC_VO alternate. Also, the UP value or the TID values 1, 2, 0, 3, 4, 5, 6, 7 may be in order of higher priority. That is, 1 may have a lower priority and 7 may have a higher priority. Therefore, the priority may increase in the order of AC_BK, AC_BE, AC_VI, AC_VO. Also, AC_BK, AC_BE, AC_VI, and AC_VO may respectively correspond to ACI (AC index) 0, 1, 2, 3.

[0124] Therefore, it is possible that there is a relationship between TID and AC. Therefore, the TID-to-link mapping of the present invention may be a mapping relationship between AC and the link. Also, in the present invention, that the TID is mapped may mean that the AC is mapped, or vice versa.

[0125] According to an embodiment of the present invention, there may be TIDs mapped to each link of the multi-link. For example, there may be a mapping for which specific TID or specific AC is allowed to be transmitted or received on any of the plurality of links. Also, such a mapping may be defined separately for each direction of both directions of the link. Also, as described above, there may be a basic (default) setting for the mapping between the TID and the link. For example, basically, all TIDs may be mapped to a certain link for the mapping between the TID and the link. Also, according to an embodiment, at a specific time point, 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.

[0126] In the present invention, a data frame corresponding to a TID or AC mapped to any direction of the link may be transmitted. Also, a data frame corresponding to a TID or AC not mapped to any direction of the link may not be transmitted.

[0127] According to an 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, it is possible to have a block ack agreement for the TIDs mapped by the TID-to-link.

[0128] It is possible to provide QoS services by performing TID-to-link mapping. For example, by mapping a high-priority AC and TID to a link with good channel conditions or few STAs, it is possible to quickly transmit data for the AC and TID. Alternatively, by performing TID-to-link mapping, it is possible to help the STA of a specific link to save power (or enter the doze state).

[0129] Referring to FIG. 10, there may be an AP MLD including AP1 and AP2. Also, there may be a Non-AP MLD including STA1 and STA2. Also, there may be two links, Link1 and Link2, in the AP MLD. AP1 and STA1 may be associated via Link1, and AP2 and STA2 may be associated via Link2.

[0130] Therefore, Link1 may include a link for transmitting from AP1 to STA1 and / or a link for transmitting from STA1 to AP1, and Link2 may include a link for transmitting from AP2 to STA2 and / or a link for transmitting from STA2 to AP2. At this time, each link may have a TID and / or an AC mapped thereto.

[0131] For example, all TIDs and all ACs may be mapped to the link for transmitting from AP1 to STA1 via Link1 and the link for transmitting from STA1 to AP1 via Link1. Also, only AC_VO or the TID corresponding to AC_VO may be mapped to the link for transmitting from STA2 to AP2 via Link2. Also, only the data of the mapped TID and / or AC can be transmitted via the link. Also, the data of the TID or AC not mapped to the link cannot be transmitted via the link.

[0132] FIG. 11 is a diagram showing an example of a multi-link NAV setting operation according to an embodiment of the present invention.

[0133] The operation of the MLD to simultaneously transmit or receive (STR; simultaneous transmit and receive; simultaneous transmission and reception) may be restricted, which may be related to the frequency spacing between a plurality of links operating in a multi-link.

[0134] Therefore, according to an embodiment of the present invention, when the spacing between links is m MHz, it is restricted to simultaneously transmit or receive, and when the spacing between links is n MHz for n greater than m, it may not be restricted to simultaneously transmit or receive. This embodiment may be for solving the problem that it is restricted to simultaneously transmit or receive, and redundant explanations may be omitted. Also, this embodiment can be applied to an MLD that does not support STR.

[0135] According to an embodiment of the present invention, duration information may be shared between links operating as a multi-link. As an example, the duration information may be TXOP duration information transmitted in the signaling field of a preamble. The signaling field may be the U-SIG field described above. Alternatively, the signaling field may be the HE-SIG-A field described above. As yet another example, the duration information may be the duration information indicated by the Duration / ID field included in the MAC header. As yet another example, the duration information may be the duration information indicated by the Length field (L Length field) included in the L-SIG field. According to an embodiment, the duration information indicated by the U-SIG field or HE-SIG-A or Duration / ID field may be a value indicating the TXOP duration. According to an embodiment, the duration information indicated by the L-SIG field may be the length of the PPDU (physical layer protocol data unit) including the L-SIG field or a value indicating the end of the PPDU including the L-SIG field.

[0136] Also, according to an embodiment of the present invention, it is possible to restrict performing transmission or channel connection during a period based on period information shared between links. The method of restricting transmission or channel connection may include setting the NAV. Or, the NAV can be reset to resume transmission or channel connection. At this time, 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, an STA belonging to the MLD can set the NAV based on a frame (or, PPDU) directed to another STA belonging to the MLD.

[0137] According to an embodiment of the present invention, an inter-link NAV may exist. The inter-link NAV may be a NAV used by STAs of a plurality of links belonging to a certain MLD when operating in a multi-link. For example, transmission on link 2 may not be necessary based on the inter-link NAV set based on the period information received on link 1. Also, the inter-link NAV can exist or be used for an MLD that is not STR-capable. For example, when the inter-link NAV is set, the MLD that set the inter-link NAV does not have to perform transmission or channel connection on a plurality of links (or, all links used by the MLD).

[0138] Also, in addition to the intra-BSS NAV as a type of NAV, a basic NAV may exist. The basic NAV may be a NAV set by an inter-BSS frame (or, PPDU), and the basic NAV may also be set by a frame (or, PPDU) for which it is not determined whether it is intra-BSS or inter-BSS.

[0139] When using the inter-link NAV separately, it may have advantages in situations where the NAV settings are updated compared to the case of not using the inter-link NAV. For example, a situation may occur where it is possible to reset the NAV set by other links. For example, although the inter-link NAV is set based on a certain frame (or PPDU), it may be determined that the frame (or PPDU) is not directed to the same MLD, and it may be acceptable to reset the set inter-link NAV. Suppose there is an MLD operating on Link 1 and Link 2. The NAV for Link 1 may be set based on the frame received on Link 1. Subsequently, the NAV of Link 1 may be updated based on the frame of Link 2. And when it is no longer necessary to maintain the NAV by Link 2, if the NAV of Link 1 is reset, there is a problem of losing the NAV information set based on the frame received on Link 1. If the inter-link NAV is used together with the NAV for each link, even if the inter-link NAV is reset, the NAV for each link is maintained, and the above problem can be solved.

[0140] Although the setting of the NAV has been taken up in the embodiments of the present invention, the embodiments of the present invention are not limited thereto and are also applicable to instructing to interrupt the channel connection in the physical layer or instructing the channel state to be busy. Also, it is not limited to resetting the NAV, and it is also applicable to instructing to continue the channel connection in the physical layer or instructing the channel state to be idle. At this time, primitives exchanged between the physical layer and the MAC layer may be used. Or, primitives exchanged between one STA of the MLD and other STAs may be used. Or, primitives exchanged between one MAC layer of the MLD and other MAC layers may be used.

[0141] 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 connection. As described above, the channel connection may be stopped based on the received period information. However, due to the position of the field including the period information or the time required for decoding, etc., there may be a time from when the PPDU starts to be received until the period information is obtained. Therefore, accessing the channel and starting transmission during this time may lead to the above-mentioned problem. Thus, according to an embodiment of the present invention, a STA of the MLD can interrupt the channel connection from the time when other STAs of the MLD start receiving. Also, when it is confirmed that the frame received after other STAs of the MLD start receiving is not directed to the other STAs, the channel connection can be started again.

[0142] FIG. 12 is a diagram showing still another example of the multi-link NAV setting operation according to an embodiment of the present invention.

[0143] FIG. 12 embodies the description of the specific method of the embodiment described in FIG. 11, and redundant description may be omitted.

[0144] As described above, based on a frame or PPDU received by a certain STA belonging to an MLD, other STAs belonging to the same MLD can suspend or resume channel connection or transmission. In the present invention, suspending channel connection or transmission may include operations such as setting (updating) the NAV, determining that the channel is busy, or suspending CCA. Also, resuming channel connection or transmission may include operations such as resetting the NAV, canceling the NAV setting, determining that the channel is idle, or performing CCA. Hereinafter, such operations can be instructed as suspending and resuming channel connection. Further, hereinafter, it can be described that STA1 and STA2 belong to an MLD, and STA1 and STA2 operate on Link1 and Link2, respectively. Also, a frame and a PPDU can be interchangeably instructed. Also, the NAV at this time may be an intra-BSS NAV or an inter-link NAV as described in FIG. 11.

[0145] According to an embodiment of the present invention, when STA1 starts receiving a frame, STA2 may interrupt the channel connection. Also, when STA1 obtains duration information from the L-SIG, STA2 may continue to have the channel connection interrupted. At this time, it can be determined that the state in which STA2 interrupts the channel connection continues until the end of the frame received by STA1. Also, when STA1 cannot surely decode the L-SIG (in the case of an invalid L-SIG), STA2 can resume the channel connection.

[0146] In addition, STA1 can receive the TXOP duration and BSS color from the U-SIG of the frame it receives. If the received BSS color indicates that it is intra-BSS or the BSS color is the BSS color corresponding to STA1, the channel connection can be interrupted. As an example, the period during which the channel connection is interrupted 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 earlier after the received frame ends. As another example, the period during which the channel connection is interrupted at this time may be the TXOP duration. In this case, the period of the channel connection interrupted based on the L-SIG may be updated. In this case, there is an advantage that the sequence following the received frame can be better protected.

[0147] Alternatively, STA1 may receive the TXOP duration and BSS color from the U-SIG of the frame it receives, and the received BSS color may not indicate that it is 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 can resume the channel connection.

[0148] Or, when the information obtained by STA1 from the U-SIG of the received frame indicates that the frame is a frame that STA1 does not receive, STA2 can resume the channel connection. For example, when the PHY identifier obtained from the U-SIG is an ID corresponding to a future standard or an unrecognizable ID, STA2 can resume the channel connection.

[0149] Also, although the case of receiving the U-SIG has been described, the same example can also be applied when receiving the HE PPDU or when receiving the HE-SIG-A. For example, the HE-SIG-A may include the TXOP duration and BSS color, and thus, the operations as described above can be performed.

[0150] In addition, STA1 may receive a STA-ID from the EHT-SIG of the frame it receives. If the received STA-ID is an indicator that STA1 should receive, for example, when the STA-ID indicates STA1, indicates the group to which STA1 belongs, or indicates broadcast, STA2 can maintain the state of interrupting the channel connection.

[0151] Alternatively, 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, when the STA-ID does not indicate an indicator corresponding to STA1, does not indicate the group to which STA1 belongs, or does not indicate broadcast, STA2 can resume the channel connection. Or, STA2 can also resume the channel connection when STA1 fails to successfully decode the EHT-SIG.

[0152] In addition, although the case of receiving the EHT-SIG has been described, the same embodiment can also be applied when receiving a HE PPDU or receiving a HE-SIG-B. For example, the HE-SIG-B may include a STA-ID, and thus, the operations as described above can be performed.

[0153] In addition, STA1 may receive the MAC header of the frame it receives. If the RA (receiver address) or DA (destination address) included in the received MAC header indicates the value that STA1 should receive, for example, when the RA or DA indicates STA1, indicates the group to which STA1 belongs, or indicates broadcast, STA2 can maintain the state of interrupting the channel connection. At this time, the period of interrupted channel access can be obtained based on the period information included in the received MAC header. More specifically, the period of interrupted channel access can be obtained based on the period information indicated by the Duration / ID field included in the received MAC header.

[0154] In addition, 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 correspond to STA1, for example, when the RA or DA does not indicate an indicator corresponding to STA1, does not indicate the group to which STA1 belongs, or does not indicate broadcast, STA2 can resume the channel connection. Or, STA1 may not receive all MAC headers. For example, STA1 may fail to receive all MPDUs included in the A-MPDU. In this case, STA2 can resume the channel connection.

[0155] The channel connection interruption and resumption described in FIG. 12 may operate in the order of decoding as the frame (or PPDU) is received and sequentially decoded at STA1. The decoding order may be based on the PPDU format, frame format, etc. For example, it can be decoded in the order of L-SIG, U-SIG, EHT-SIG, MAC header (in the case of EHT PPDU). Or, it can be decoded in the order of L-SIG, HE-SIG-A, MAC header (in the case of HE SU PPDU, HE TB PPDU). Or, it can be decoded in the order of L-SIG, HE-SIG-A, HE-SIG-B, MAC header (in the case of HE MU PPDU). Or, it can be decoded in the order of L-SIG, MAC header (in the case of 11a / g PPDU).

[0156] According to an embodiment of the present invention, the aforementioned STA-ID may be a value indicating the intended receiver of the PPDU or RU (resource unit). Also, the STA-ID may be included in the EHT-SIG field or HE-SIG-B field, etc. Also, the STA-ID can indicate a value corresponding to a single STA. For example, when a plurality of STAs are included in the MLD, the STA-ID can indicate a value corresponding to one of the plurality of STAs. Also, the STA-ID may be a value based on the AID or MAC address of the STA.

[0157] FIG. 13 is a diagram showing an example of BSS classification and operations based thereon according to an embodiment of the present invention.

[0158] 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 a received frame or a received PPDU corresponds to the BSS to which the STA that classifies it belongs. Or, classifying a BSS may mean an operation of classifying whether a received frame or a received PPDU is transmitted from the BSS to which the STA that classifies it belongs. Also, classifying a BSS may include an operation of classifying whether a received frame or a received PPDU corresponds to a BSS to which the STA that classifies it does not belong. Or, classifying a BSS may mean an operation of classifying whether a received frame or a received PPDU is transmitted from a BSS to which the STA that classifies it 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, the BSS to which the STA that classifies it belongs can be called an intra-BSS. Or, a BSS including the BSS to which the STA that classifies it belongs can be called an intra-BSS. Also, a BSS that is not an intra-BSS can be called an inter-BSS. Or, a BSS that is not an intra-BSS may be an inter-BSS or a BSS that is not classified. Or, an inter-BSS may include a BSS that is not classified. Also, a BSS to which the STA that classifies it does not belong can be called an inter-BSS.

[0159] According to one embodiment, when it is determined that the received frame or the received PPDU belongs to an intra-BSS or is transmitted from an intra-BSS, the received frame or the received PPDU can be referred to as an intra-BSS frame and an intra-BSS PPDU, respectively. Also, when it is determined that the received frame or the received PPDU belongs to an inter-BSS or is transmitted from an inter-BSS, the received frame or the received PPDU can be referred to as an inter-BSS frame and 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.

[0160] According to one embodiment of the present invention, a BSS can be classified based on one or more BSS classification conditions. For example, the BSS can be classified according to whether or not at least one of the one or more BSS classification conditions is satisfied.

[0161] The BSS classification condition may include a condition based on BSS color. The BSS color may be an identifier for the BSS. Further, the BSS color may be included in the preamble of the PPDU, more specifically, in the signaling field (e.g., HE-SIG-A field or U-SIG field or VHT-SIG-A field). Further, the BSS color may be included in the TXVECTOR transmitted from the MAC layer of the sender to the PHY layer. Further, the BSS color may be included in the RXVECTOR transmitted from the PHY layer of the receiver to the MAC layer. The parameters included in the TXVECTOR and RXVECTOR can be called TXVECTOR parameters and RXVECTOR parameters, respectively. Further, the BSS color may be included in the TXVECTOR parameters or the RXVECTOR parameters. Also, the AP can notify the STA of the BSS color set by the AP. According to one embodiment, the BSS can 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. Or, 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.

[0162] The BSS classification condition may include a condition based on the MAC address. The MAC address may be included in the MAC header of the frame. Further, the MAC address may include the RA (receiver address), TA (transmitter address), BSSID, SA (source address), DA (destination address), etc. According to one embodiment, the BSS can be classified based on the MAC address included in the received frame. If the MAC address included in the received frame is different from the BSSID of the BSS corresponding to the STA, the received frame can be classified as an inter-BSS frame. More specifically, if all of the MAC addresses included in the received frame are different from the BSSID of the BSS corresponding to the STA, the received frame can be classified as an inter-BSS frame. Also, if the MAC address included in the received frame is the same as the BSSID of the BSS corresponding to the STA, the received frame can be classified as an intra-BSS frame. More specifically, if at least one of the MAC addresses included in the received frame is the same as the BSSID of the BSS corresponding to the STA, the received frame can be classified as an intra-BSS frame.

[0163] The corresponding BSS may include the BSS with which the STA is associated. Further, the corresponding BSS may include the BSS included in the same multiple BSSID set as the BSS with which the STA is associated. Also, the corresponding BSS may include the BSS included in the same co-hosted BSSID set as the BSS with which the STA is associated. Also, information regarding the one or more BSSs included in the same multiple BSSID set or the same co-hosted BSSID set may be transmitted to the one or more BSSs through one frame.

[0164] The BSS classification condition may include a condition based on the Partial AID field value included in the VHT PPDU. The Partial AID field may be included in the preamble of the VHT PPDU. Also, the Partial AID field may be included in the VHT-SIG-A field included in the VHT PPDU. According to one embodiment, the Partial AID field can indicate a part of the BSS color. For example, when using the partial BSS color function, the Partial AID field can indicate a part of the BSS color. Or, when using an AID assignment rule, the Partial AID field can 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 preset value (for example, when the Group ID field is set to 63), the Partial AID field can indicate a part of the BSS color. According to one embodiment, when the Partial AID field of the received PPDU indicates a part of the BSS color, if the received Partial AID field value is different from the part of the BSS color corresponding to the received STA, the received PPDU can be classified as an inter-BSS PPDU.

[0165] Also, when the Partial AID field of the received PPDU indicates a part of the BSS color, if the received Partial AID field value is the same as the part of the BSS color corresponding to the received STA, the received PPDU can be classified as an intra-BSS PPDU. Also, at this time, a part of the BSS color can be the 4 LSBs of the BSS color. According to another embodiment, the Partial AID field can indicate a part of the BSSID. For example, when the Group ID field included in the VHT-SIG-A field of the VHT PPDU is a preset value (for example, when the Group ID field is set to 0), the Partial AID field can indicate a part of the BSSID. According to one embodiment, when the Partial AID field of the received PPDU indicates a part of the BSSID, if the received Partial AID field value is different from the part of the BSSID corresponding to the received 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 the part of the BSSID corresponding to the received STA, the received PPDU can be classified as an intra-BSS PPDU. Also, at this time, a part of the BSSID can be the 9 MSBs of the BSSID. Also, the Partial AID field value may be included in the TXVECTOR parameter PARTIAL_AID or the RXVECTOR parameter PARTIAL_AID. Also, the Group ID field value may be included in the TXVECTOR parameter GROUP_ID or the RXVECTOR parameter GROUP_ID.

[0166] The BSS classification conditions may include the condition that the AP receives a PPDU that meets the already set conditions. For example, the PPDU that meets the already set conditions may include a downlink PPDU. According to one embodiment, the downlink PPDU may include a VHT MU PPDU. Also, the downlink PPDU may include a PPDU in which the signaling indicating whether it is an uplink or a downlink is set to a already set value. The signaling indicating whether it is an uplink or a downlink may be included in the signaling field of the HE PPDU. Or, the signaling indicating whether it is an uplink or a downlink may be included in the U-SIG. The U-SIG may be included in the preamble of the EHT PPDU or a PPDU after the EHT standard.

[0167] Also, there may be cases where it cannot be classified as an intra-BSS PPDU or an inter-BSS PPDU. For example, when neither the conditions for classifying as the aforementioned intra-BSS PPDU nor the conditions for classifying as the inter-BSS PPDU can be satisfied, it cannot be classified as an intra-BSS PPDU or an inter-BSS PPDU.

[0168] Also, when classifying the BSS, if the classification results based on multiple conditions do not match, it is possible to determine the final result according to the already set conditions. For example, when the result based on the condition based on the BSS color and the result based on the condition based on the MAC address do not match, the result based on the condition based on the MAC address may be prioritized, or the result based on the condition based on the MAC address may be determined as the final result. Or, when both the conditions for classifying as an intra-BSS PPDU and the conditions for classifying as an inter-BSS PPDU are satisfied, it can be classified as an intra-BSS PPDU.

[0169] According to an embodiment of the present invention, the STA can perform operations based on the classified BSS. The operations based on the classified BSS may include intra-PPDU power save operations. The intra-PPDU power save operation may be a power save operation based on the received PPDU. It is possible to perform the intra-PPDU power save operation when the already set conditions are satisfied. The already set conditions may include conditions for classifying the received PPDU as an intra-BSS PPDU. Also, the already set conditions may include the condition that the intended receiver of the received PPDU is not the STA that received the PPDU. For example, when the ID or address included in the PPDU does not correspond to the STA that received the PPDU, the intended receiver of the PPDU may not be the STA that received the PPDU. The ID may be included in the preamble of the PPDU. For example, the ID may be the STA_ID included in the preamble of the PPDU. Also, the STA_ID may be included in the HE MU PPDU or the EHT PPDU. Also, the address may be the MAC address described above. Also, when the signaling indicating whether the received PPDU is an uplink or a downlink indicates an uplink, the intended receiver of the PPDU may not be the STA that received the PPDU. Also, when the setting of the received PPDU is set to something that the STA that received the PPDU does not support, the intended receiver of the PPDU may not be the STA that received the PPDU. The setting of the received PPDU may include the MCS of the PPDU, the number of spatial streams, the channel width, etc. Also, when the setting of the received PPDU is not supported by the STA that received the PPDU, the PHY-RXEND.indication(UnsupportedRate) primitive may be received. Also, when the received PPDU is in the already set format, the intended receiver of the PPDU may not be the STA that received the PPDU. The already set format may include the TB PPDU.A TB PPDU may include a HE TB PPDU and an EHT TB PPDU. Also, a TB PPDU may be a PPDU transmitted as a response to a triggering frame. The triggering frame may include a trigger frame. The triggering frame may include a frame containing triggering information. The triggering information may be included in a MAC header, for example, an A-control field. Also, the information included in the triggering information or the trigger frame may include the length of the responding PPDU, the RU used during response, the PHY configuration used during response, the MAC configuration, etc. The intra-PPDU power saving operation may be an operation that can enter the doze state until the end of the received PPDU. As another example, when it is determined that the intended recipient of the PPDU or frame received by the STA is not the STA, the reception or decoding of the PPDU or frame can be interrupted.

[0170] The operation based on the classified BSS may include the operation of setting (or updating) the NAV. According to one embodiment, the STA can operate one or more NAVs. Also, when the STA receives a PPDU or a frame, it is possible to set the NAV corresponding to the BSS classified based on the received PPDU or the received frame. For example, the intra-BSS NAV may be the NAV corresponding to the intra-BSS PPDU. Also, the basic NAV may be the NAV corresponding to a PPDU that is not an intra-BSS PPDU. Or, the basic NAV may be the NAV corresponding to an inter-BSS PPDU. Also, when setting the NAV based on the received PPDU or the received frame, it is possible to use the duration information included in the received PPDU or the received frame. The duration information may include the TXOP. The TXOP can mean the value included in the TXOP field. The TXOP field may be included in the preamble of the PPDU. For example, the TXOP field may be included in the HE-SIG-A field of the HE PPDU. Or, the TXOP field may be included in the U-SIG field of the EHT PPDU or a PPDU of a standard after EHT. 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.

[0171] Operations based on the classified BSS may include spatial reuse operations. Also, operations based on the classified BSS may include channel connection operations. The spatial reuse operation may be a channel connection operation. When a STA receives a PPDU or a frame, if the already set conditions are satisfied, it is possible to perform a spatial reuse operation. The already set conditions may include conditions where the received PPDU or the received frame corresponds to an inter-BSS. Also, the already set conditions may include conditions where 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 OBSS PD-based Spatial reuse operations. 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 the PHY. For example, the operation of resetting the PHY may be an operation of issuing a PHY-CCARESET.request primitive. Also, the spatial reuse operation may include an operation of not setting the NAV based on the received PPDU or the received frame. If the STA performs a spatial reuse operation, it may be possible for the STA to transmit a PPDU while the received PPDU or the received frame is being transmitted or received.

[0172] Referring to FIG. 13, BSS A and BSS B may exist, and BSS A and BSS B may be different BSSs from each other. Also, BSS A and BSS B may correspond to each other in inter-BSS. That is, a PPDU or frame transmitted by a STA associated with BSS B in BSS A may be classified as an inter-BSS PPDU or an inter-BSS frame. Also, there may be STAs STA1 and STA2 belonging to (or associated with an AP operating BSS A). There may be STAs STA3 and STA4 belonging to (or associated with an AP operating BSS B). Referring to FIG. 13, STA1 can transmit a PPDU. Also, the PPDU transmitted by STA1 may include information about the BSS. For example, the information about the BSS may be information for classifying the aforementioned BSS. Also, the PPDU transmitted by STA1 may include Duration information.

[0173] 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 that is not the intended recipient of the STA. Therefore, according to the above-described embodiments, STA2 can perform intra-PPDU power saving. Referring to FIG. 13, STA2 can enter the doze state until the time at the end of the received PPDU. Also, STA2 can set the NAV based on the Duration information included in the received PPDU. Since STA2 classifies the received PPDU as an intra-BSS PPDU, it is possible to set the intra-BSS NAV.

[0174] STA3 can receive the PPDU transmitted by STA1 and classify the BSS for this PPDU. Also, 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. Further, STA3 can set the NAV based on the Duration information included in the received PPDU. Since STA3 classifies the received PPDU as an inter-BSS PPDU, it is possible to set the basic NAV.

[0175] STA4 can receive the PPDU transmitted by STA1 and classify the BSS for this PPDU. Also, 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. Also, the signal strength of the PPDU received by STA4 may be less than the threshold value. 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 less than the threshold value, STA4 can perform a spatial reuse operation. Therefore, STA4 can perform a channel connection and a backoff procedure and start transmission. For example, it may be possible for STA4 to start transmission when the PPDU transmitted by STA1 has not ended.

[0176] FIG. 14 shows a wireless LAN function according to an embodiment of the present invention.

[0177] Referring to FIG. 14, a certain standard wireless LAN may include the functions of other standard wireless LANs. Or, when it is a certain standard wireless LAN, it may be another standard wireless LAN. Here, the wireless LAN can mean a STA. Further, here, the wireless LAN may mean an MLD including a STA. For example, the wireless LAN standard may include the functions of previous generation standards and additional functions. For example, an HT STA can also be an OFDM PHY STA. Also, an HT STA can perform additional functions in addition to the functions of an OFDM PHY STA. For example, a VHT STA can also be an HT STA. Also, a VHT STA can perform additional functions in addition to the functions of an HT STA. For example, an HE STA can also be a VHT STA. Also, an HE STA can perform additional functions in addition to the functions of a VHT STA. Also, an EHT STA can also be an HE STA. Also, an EHT STA can 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 conforming to the NEXT standard can be called the NEXT STA. The NEXT STA can also be an EHT STA. Also, the NEXT STA can perform additional functions in addition to the functions of the EHT STA.

[0178] FIG. 14 is a diagram showing the relationship between STAs of each standard. Referring to FIG. 14, if it is an EHT STA, it can be an HE STA, a VHT STA, an HT STA, and an OFDM PHY STA. Also, if it is a NEXT STA, it can be an EHT STA, an HE STA, a VHT STA, an HT STA, and an OFDM PHY STA.

[0179] FIG. 15 shows the uplink (UL) multi-user (MU) operation according to an embodiment of the present invention.

[0180] Referring to FIG. 15, the AP can instruct at least one STA to transmit a PPDU through a specific frame (e.g., a triggering frame), and at least one STA can simultaneously transmit PPDUs of the same or individual formats based on the specific frame transmitted from the AP.

[0181] Specifically, as shown in FIG. 15, a frame that instructs or triggers multi-user (MU) transmission may be transmitted, and based on such a frame, one or more STAs can transmit or respond to such a frame. At this time, when one or more STAs transmit a response to the frame, based on the frame, one or more STAs can simultaneously give an immediate response, and the response to the frame may start to be transmitted after SIFS from the end of the PPDU containing the frame. For example, when the frame instructs an immediate response, one or more STAs can immediately transmit a response to the frame. A frame that instructs or triggers transmission to one or more STAs may be a trigger frame or a frame included in the MAC header that contains information instructing or triggering uplink transmission to one or more STAs. At this time, the frame may include in the MAC header information (e.g., a TRS control subfield) that triggers or instructs uplink transmission to only one STA.

[0182] For example, the information instructing or triggering uplink transmission included in the MAC header may be a triggered response scheduling (TRS) or a TRS control subfield included in an HT control field, a control subfield, or an A-control subfield.

[0183] Frames for instructing or triggering uplink transmission may be transmitted by the AP. When the frame for instructing or triggering uplink transmission is a trigger frame, the response thereto may be transmitted in the trigger-based PPDU (TB PPDU) format. At this time, the TB PPDDU may include, in addition to the HE TB PPDU and EHT TB PPDU described above, the NEXT TB PPDU that may be defined in the following standard.

[0184] The HE TB PPDU may be composed of a preamble, data, and a packet extension (PE). The preamble may sequentially include L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, HE-STF, and HE-LTF.

[0185] The EHT TB PPDU and NEXT TB PPDU may also be composed of a preamble, data, PE, etc. The preambles of the EHT TB PPDU and NEXT TB PPDU may sequentially include L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, (EHT- / NEXT-)STF, and (EHT- / NEXT-)LTF.

[0186] A frame for instructing or triggering the transmission of a PPDU to one or more STAs may include information necessary for one or more STAs to transmit a TB PPDU. For example, when the type subfield included in the frame is "01" (B3 B2) and the subtype subfield is "0010" (B7 B6 B5 B4), a frame including such type and subtype subfields may be a trigger frame that is a control frame.

[0187] If the formats of the PPDUs to be responded by multiple STAs are different from each other when the response to the TB PPDU is instructed or triggered for the multiple STAs, there may occur a problem that it is difficult for the AP that instructed or triggered the response to receive the PPDU which is the response transmitted from the multiple STAs. Or, if the information included in the preambles of the PPDUs to be responded by the multiple STAs is different from each other depending on the format, there may occur a problem that it is difficult for the AP that instructed or triggered the response to receive the PPDU which is the response transmitted from the multiple STAs.

[0188] Therefore, in order to solve such problems, when multiple STAs respond to the frame of the AP, the format of the PPDU to be responded and / or the type of the information included in the preamble of the PPDU may be set to be the same. For example, when multiple STAs transmit an HE TB PPDU as a response to the frame of the AP, the AP may transmit information so that the preambles transmitted by the multiple STAs can be successfully received by the AP, or an agreement on the information included in the HE TB PPDU may be defined so that the information included in L-STF, L-LTF, L-SIG, RL-SIG, and HE-SIG-A is the same. However, if the TB PPDU formats are different from each other when HE TB PPDU, EHT TB PPDU, and NEXT TB PPDU are simultaneously transmitted in an overlapping subband, there may occur a problem that it is difficult for the AP to receive them.

[0189] According to an embodiment of the present invention, an HE STA can transmit an HE TB PPDU. Also, an EHT STA can transmit an EHT TB PPDU or an HE TB PPDU. Also, a NEXT STA can transmit a NEXT TB PPDU or an EHT TB PPDU or an HE TB PPDU. This is because, as described in FIG. 10, a certain standard STA may include the functions of a previous standard.

[0190] As shown in FIG. 15, when AP transmits a frame for scheduling the transmission of a TB PPDU to a HE STA and an EHT STA, and instructs or triggers the transmission of the TB PPDU using the frame, there may be no exact instruction or protocol for the TB PPDU format. In this case, the HE STA transmits a HE TB PPDU as a response to the frame, and the EHT STA can respond with an EHT TB PPDU or a HE TB PPDU. In this case, the AP may have difficulty receiving the TB PPDUs transmitted by these STAs. The AP may not be able to successfully receive TB PPDUs from multiple STAs, and although the transmission was not successful, the medium may be occupied, resulting in a problem that the transmission opportunities of other STAs are reduced.

[0191] Hereinafter, in the present invention, instructing an STA may mean instructing a response from the STA, and trigger and instruction may be used in the same meaning.

[0192] Also, the HE trigger frame, the EHT trigger frame, and the NEXT trigger frame may each be a trigger frame defined by the HE, EHT, and NEXT standards. Also, in the present invention, the HE TRS, the EHT TRS, and the NEXT TRS may each be a TRS defined by the HE, EHT, and NEXT standards.

[0193] FIG. 16 shows a trigger frame format according to an embodiment of the present invention.

[0194] FIG. 16(a) shows the trigger frame format, and FIGS. 16(b) and 16(c) show the common information field and the user information field, which are fields included in the trigger frame, respectively.

[0195] Referring to Fig. 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.

[0196] The common information field may include information that is common to all STAs indicated by the trigger frame. Fig. 12(b) shows an example of the common information field.

[0197] The user information list field may include zero or more user information fields. The user information list field of a trigger frame, excluding a specific type of trigger frame, may include one or more user information fields. Fig. 16(c) shows an example of a user information field.

[0198] As an addition, the trigger frame may further 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 ensure the time required for the STA receiving the trigger frame to prepare a response to the trigger frame, and may be selectively included in the trigger frame.

[0199] Referring to FIG. 16(b), 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 Info subfield and the Trigger Dependent User Info 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.

[0200] The common information field may include an uplink (UL) length subfield. The UL length subfield may include information regarding the length of the TB PPDU that is a response to the trigger frame, and may include information regarding the length of the frame that responds to the trigger frame. Also, the UL length subfield can indicate the value included in the length subfield of the L-SIG of the TB PPDU that responds to the trigger frame. Therefore, a STA that receives a trigger frame and responds with a TB PPDU can set the value of the length subfield included in the L-SIG of the TB PPDU based on the value of the UL length subfield included in the received trigger frame. Specifically, a STA that responds with a TB PPDU can set the length subfield included in the L-SIG of the TB PPDU to the value of the UL length subfield included in the received trigger frame. For example, the STA can set 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 and transmit the TB PPDU.

[0201] Also, the common information field may further include an uplink bandwidth subfield (UL Bandwidth (BW) subfield). The UL BW subfield can indicate the BW value included in the signaling field (e.g., HE-SIG-A or U-SIG, etc.) of the TB PPDU that responds to the trigger frame, and can indicate the maximum BW of the TB PPDU transmitted as a response to the trigger frame. Therefore, the STA can set the BW value included in the signaling field of the TB PPDU based on the value of the UL BW subfield included in the trigger frame.

[0202] Also, the common information field may further include information such as that included in the signaling field of the TB PPDU which is a response to the trigger frame. Therefore, after receiving the trigger frame, the STA can set the information included in the TB PPDU based on the information included in the trigger frame.

[0203] Referring to FIG. 16(c), the user information field may include an AID12 subfield. The AID12 subfield may be used to indicate the intended recipient of the user information field including the AID12 subfield or the function of the user information field. Thus, the AID12 subfield can also play a role in indicating the intended recipient of the trigger frame including the AID12 subfield or the function of the trigger frame. For example, when the value of the AID12 subfield is a preset value, the user information field can indicate an RA-RU (Random Access Resource Unit). That is, the preset value of the AID12 subfield can indicate that the user information field indicates an RA-RU. Specifically, when the value of the AID12 subfield is "0", the user information field can indicate an RA-RU for the associated STAs. For example, when the value of the AID12 subfield is "0", the user information field can indicate an RA-RU for the associated STAs, and when the value of the AID12 subfield is "2045", the user information field can indicate an RA-RU for the unassociated STAs. The STA corresponding to the STA ID (e.g., AID (association ID)) indicated by the value of the AID12 subfield may be instructed to respond by the user information field including the AID12 subfield or the trigger frame including the AID subfield. For example, the AID12 subfield can indicate an AID or the 12 LSBs of an AID. The STA corresponding to the value indicated by the AID12 subfield can transmit a TB PPDU as a response to the received trigger frame. In this case, the value of the AID12 subfield may be in the range from "1" to "2007" (including 1 and 2007), and when the AID12 subfield is a preset value (e.g., "2046", etc.), the RU corresponding to the preset value of the AID12 subfield does not have to be assigned to any STA.Also, when the value already set in the AID subfield (for example, "4095" etc.) is present, the already set value can indicate the start of padding of the trigger frame.

[0204] The information of 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 can indicate the size and location of the RU etc. At this time, the value of the RU allocation subfield of 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 of the AID12 subfield may be the RU allocated to the STA indicated by the AUD12 subfield.

[0205] Also, the user information field can indicate a coding method (UL FEC coding type), a modulation method (UL HE-MCS, UL DCM), and power (UL Target RSSI), etc. for the generation of the TB PPDU transmitted as a response to the trigger frame.

[0206] FIG. 17 shows a method for indicating a triggered-based (TB) PPDU format according to an embodiment of the present invention.

[0207] Referring to FIG. 17, one STA can selectively transmit PPDUs in different formats based on being indicated by a triggering frame that indicates the transmission of the PPDU.

[0208] Specifically, the EHT STA can selectively transmit not only legacy PPDUs (e.g., HE TB PPDUs) but also EHT TB PPDUs, and the NEXT STA can selectively transmit HE TB PPDUs, EHT TB PPDUs, and / or NEXT TB PPDUs. In this case, STAs to which multiple standards are respectively applicable in one frame or one PPDU can be individually scheduled. Since multiple STAs to which multiple standards are applicable share common resources in a wireless LAN, such a method can be advantageous. For example, an HE STA (an HE STA other than an EHT STA) and an EHT STA can be made to respond with an HE TB PPDU using one frame. That is, the non-AP STA can transmit a triggering frame and instruct the transmission of an HE TB PPDU not only to the HE STA but also to the EHT STA.

[0209] Also, information for selecting the TB PPDU format may be included in a trigger frame which is a triggering frame, a TRS, a PPDU including the triggering frame, or a PPDU including a TRS control subfield. That is, the AP STA includes information for selecting the format of the TB PPDU in the 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 respond based on the information included in the received triggering frame. Thereafter, at least one non-AP STA can transmit a PPDU to the AP based on the selected format.

[0210] Information regarding the format (TB PPDU format) of the PPDU 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 the respective trigger frames may be classified into HE TB PPDUs, EHT TB PPDUs, and NEXT TB PPDUs.

[0211] Moreover, distinguishing the trigger frame into an HE trigger frame, an EHT trigger frame, and a NEXT trigger frame may have the same meaning as distinguishing 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.

[0212] 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 the Frame Control field included in the MAC header. Specifically, the format of the trigger frame may be distinguished based on the Type subfield, the Subtype subfield, and / or the Control Frame Extension subfield. Also, when the values of the Type subfield, the Subtype subfield, and / or the Control Frame Extension subfield are already set values, the trigger frame may be identified as an HE trigger frame, and when they are other already set values, the trigger frame may be identified as an EHT trigger frame. Further, when the values of the Type subfield, the Subtype subfield, and / or the Control Frame Extension subfield are other already set values, the trigger frame may be identified as a NEXT trigger frame.

[0213] For example, when 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, the entries of the Type subfield (2 bits), the Subtype subfield (4 bits), and / or the Control Frame Extension subfield (4 bits) with limited number of bits may need to be further used in the EHT standard and the NEXT standard.

[0214] Alternatively, whether the format of the trigger frame is a HE trigger frame or an EHT trigger frame may be identified based on a common information field included in the trigger frame. That is, based on the value of a specific subfield (first subfield) included in the common information field, the format of the PPDU transmitted as a response to the trigger frame may be determined. For example, depending on the value of the common information field, a non-AP STA may select a HE TB PPDU or an EHT TB PPDU and transmit it using the assigned RU. At this time, in addition to the common information field, a specific subfield (second subfield) of the user information field may also be further used to identify the format of the PPDU.

[0215] That is, based on the common information field of the trigger frame, a variant for determining the format of the PPDU that is a response to the trigger frame may be determined, 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 by the common information field is determined to be a HE variant, a non-AP STA can respond with a HE TB PPDU, and when the variant for determining the format of the PPDU by the common information field is determined to be an EHT variant, a non-AP STA can respond with an EHT TB PPDU.

[0216] At this time, for the variant for determining the format of the PPDU, in addition to the common information field, the user information field may also be further used.

[0217] For example, the trigger frame may be classified as an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame based on the trigger type subfield. For example, when the trigger type subfield value is a preset value, the trigger frame may be an HE trigger frame. Also, when the trigger type subfield value is a preset value, the trigger frame may be an EHT trigger frame. When the trigger type subfield value is a preset value, the trigger frame may be a NEXT trigger frame.

[0218] For example, when the trigger type subfield value is from 0 to 7, it may be an HE trigger frame, and when it is not from 0 to 7, it may be an EHT trigger frame or a NEXT trigger frame. The trigger type subfield indicates various trigger frame types, but in this case, there is a disadvantage that a limited trigger type subfield space must be used.

[0219] According to still another embodiment, based on the UL length subfield of the trigger frame, it can be determined whether it is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame. For example, based on the value obtained by performing a mod (remainder) operation on the UL length subfield value, it can be determined whether it is an HE trigger frame, an EHT trigger frame, or a NEXT trigger frame. That is, using the value of the UL length subfield, it may be determined whether the format of the PPDU transmitted as a response to the trigger frame is an HE PPDU or an EHT PPDU.

[0220] More specifically, based on the value obtained by performing a modulo (remainder) 3 operation on the UL length subfield value (the remainder when the UL length subfield is divided by 3), it is possible to distinguish whether it is a HE trigger frame, an EHT trigger frame, or a NEXT trigger frame. For example, when the result of performing a modulo 3 operation on the UL length subfield value is not 0, the trigger frame may be a HE trigger frame. Or, when the result of performing a modulo 3 operation on the UL length subfield value is 1, the trigger frame may be a HE trigger frame. Or, when the result of performing a modulo 3 operation on the UL length subfield value is 0, the trigger frame may not be a HE trigger frame. Or, when the result of performing a modulo 3 operation on the UL length subfield value is 0, the trigger frame may be an EHT trigger frame or a NEXT trigger frame.

[0221] That is, when the value obtained by performing a modulo 3 operation on the value of the UL length subfield of the trigger frame is not 0, the response to the trigger frame may be transmitted as a HE TB PPDU, and when the value obtained by performing a modulo 3 operation on the value of the UL length subfield is 1, the response to the trigger frame may be transmitted as a HE TB PPDU.

[0222] Also, when the value obtained by performing a modulo 3 operation on the value of the UL length subfield of the trigger frame is 0, the format of the PPDU transmitted as a response to the trigger frame may be an EHT TB PPDU.

[0223] In addition, it is possible to distinguish HE trigger frames, EHT trigger frames, and NEXT trigger frames by using such a method together with an additional trigger frame classification method. For example, it is possible to distinguish HE trigger frames, EHT trigger frames, and NEXT trigger frames by using the classification method described in FIG. 16 together.

[0224] According to one embodiment, based on the User Info field of the trigger frame, it may be determined whether the format of the trigger frame is a HE trigger frame, an EHT trigger frame, or a NEXT trigger frame.

[0225] That is, similar to the common information field described above, whether the format of the trigger frame is a HE trigger frame or an EHT trigger frame can be identified based on the user information field included in the trigger frame. That is, based on the value of a specific sub-field (second sub-field) included in the user information field, the format of the PPDU transmitted as a response to the trigger frame may be determined. For example, depending on the value of the user information field, the non-AP STA can select a HE TB PPDU or an EHT TB PPDU and transmit it using the assigned RU. In this case, in addition to the user information field, a specific sub-field (first sub-field) of the common information field may be further used to identify the format of the PPDU.

[0226] That is, based on the user information field of the trigger frame, a variant for determining the format of the PPDU that is a response to the trigger frame may be determined, and the format of the PPDU may be determined according to the determined variant. For example, when the variant for determining the format of the PPDU is determined to be a HE variant by the user information field, the non-AP STA can respond with a HE TB PPDU, and when the variant for determining the format of the PPDU is determined to be an EHT variant by the user information field, the non-AP STA can respond with an EHT TB PPDU.

[0227] At this time, in addition to the user information field, the common information field may be further used for the variant for determining the format of the PPDU.

[0228] For example, based on the AID12 subfield, it may be classified as a HE trigger frame, an EHT trigger frame, or a NEXT trigger frame. According to one embodiment, whether it is a HE trigger frame, an EHT trigger frame, or a NEXT trigger frame may be classified according to whether it includes the AID12 subfield of a preset value. Also, in this case, it may be a problem whether the STA indicated by a certain user information field should continuously check the AID12 subfield existing after the user information field to determine the trigger frame format. To solve such a problem, the user information field including the AID12 subfield indicating which trigger frame it is may exist in front of the user information list. Also, in order to prevent a HE STA that cannot understand such a signaling method from malfunctioning, it is possible that there is a user information field including the AID12 subfield indicating which trigger frame it is after the user information field corresponding to the HE STA.

[0229] Also, at this time, since the information of other sub-fields other than the AID12 sub-field included in the user information field may not be necessary for the TB PPDU response, the sub-field of the user information field including the AID12 sub-field indicating which trigger frame it is may be omitted. That is, the length of the user information field may vary based on the AID12 sub-field. Referring to FIG. 15, the AID12 sub-field can play a role in indicating the response TB PPDU format. For example, when the AID12 sub-field has a preset value, the response to the trigger frame including the AID12 sub-field set to the preset value may be an EHT TB PPDU. For example, when the AID12 sub-field value is 2047, the response to the trigger frame including the AID12 sub-field may be an EHT TB PPDU. Also, when the AID12 sub-field has a preset value, the response to the trigger frame including the AID12 sub-field set to the preset value may be a NEXT TB PPDU. For example, when the AID12 sub-field value is 2048, the response to the trigger frame including the AID12 sub-field may be a NEXT TB PPDU.

[0230] According to still other embodiments, when responding based on the user information field existing at the already set position from the AID12 subfield of the already set value, it is possible to respond in the TB PPDU format corresponding to the already set value. For example, when responding based on the user information field existing after the AID12 subfield of the already set value, it is possible to respond in the TB PPDU format corresponding to the already set value. If there are multiple values indicating the TB PPDU format, when responding based on the user information field existing after both the already set value 1 and the already set value 2, among the TB PPDU format corresponding to the already set value 1 and the TB PPDU format corresponding to the already set value 2, it is possible to respond in the TB PPDU format according to the already set priority order. Referring to FIG. 15, when responding based on the user information field existing after the AID12 subfield set to 2047, it is possible to respond with an EHT TB PPDU. Also, when responding based on the user information field existing after the AID12 subfield set to 2048, it is possible to respond with a NEXT TB PPDU. Also, when responding based on the user information field existing after both the AID12 subfield set to 2047 and the AID12 subfield set to 2048, it is possible to respond with a NEXT TB PPDU. Also, when responding based on the user information field existing before both the AID12 subfield set to 2047 and the AID12 subfield set to 2048, it is possible to respond with a HE TB PPDU.

[0231] In this embodiment, an example where the AID12 subfield indicates the type of trigger frame is taken, but the present invention is not limited to this, and it is also possible to indicate the type of trigger frame with other subfields of the user information field.

[0232] According to one embodiment, whether it is a HE trigger frame, an EHT trigger frame, or a NEXT trigger frame may be determined based on the padding field of the trigger frame. For example, whether it is a HE trigger frame, an EHT trigger frame, or a NEXT trigger frame can be determined by whether the padding field contains a pre-set value indicating whether it is a HE trigger frame, an EHT trigger frame, or a NEXT trigger frame.

[0233] According to the embodiments of the present invention, it is possible to classify HE trigger frames, EHT trigger frames, and NEXT trigger frames by combining a plurality of trigger frame classification methods described in the present invention. In addition, the content described about the trigger frame in the present invention is not limited to the above, and is also applicable to TRS.

[0234] As yet another embodiment of the present invention, the AP may not be able to instruct the transmission of both the EHT PPDU and the HE PPDU using a trigger frame. That is, the EHT AP cannot transmit a trigger frame that instructs both the HE TB PPDU and the EHT TB PPDU, and can only instruct one PPDU format.

[0235] FIG. 18 shows UL MU operation according to yet another embodiment of the present invention.

[0236] 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 an A-control field, it is possible to include the TRS. The TRS can be transmitted by the TRS control subfield. The A-control field may be in a form in which the control list field continues continuously. Also, the control list field may include the TRS.

[0237] Also, a receiver (indented receiver) of a frame including a TRS can respond to the TRS. For example, a STA corresponding to the RA included in a frame including a TRS can respond to the TRS. The TRS may include information regarding the length of a PPDU or frame that responds to the TRS (UL Data Symbols), the position and size of the RU used when responding to the TRS (RU Allocation), information regarding power when responding to the TRS (AP Tx Power, UL Target RSSI), information regarding the modulation method when responding to the TRS (UL HE-MCS), and the like.

[0238] The embodiment of FIG. 18 may be a method for solving the problems described in FIGS. 14 to 15. Also, as described above, the embodiments regarding the above trigger frame are also applicable to the TRS. Also, the above-described content may be omitted.

[0239] According to an embodiment of the present invention, in addition to the TRS (HE TRS) defined by the HE standard, it is also possible to have a TRS defined by the EHT standard or the NEXT standard (EHT TRS and NEXT TRS, respectively). Therefore, depending on whether the indicated TRS is any one of HE TRS, EHT TRS, and NEXT TRS, the TB PPDU that responds to the TRS may be HE TB PPDU, EHT TB PPDU, or NEXT TB PPDU, respectively. For example, which standard the defined TRS belongs to can be determined by the Control ID subfield of the A-control subfield. As an additional embodiment, the TRS can be divided into two types: HE TRS and TRS other than HE TRS.

[0240] Alternatively, for example, which standard-defined TRS it is may be determined by whether the HT control field is a HE variant, an EHT variant, or a NEXT variant. Also, whether it is a HE variant, an EHT variant, or a NEXT variant may be determined by the values of the already set bits in the HT control field. For example, when B0 and B1 of the HT control field are 1 and 1, it may be a HE variant. Also, using B0, B1 of the HT control field and an additional bit (e.g., B31), whether it is a HE variant, an EHT variant, or a NEXT variant can be determined.

[0241] According to an embodiment of the present invention, based on the PPDU format including the TRS, it is possible to determine the TB PPDU format in response to the TRS. That is, when the PPDU instructing the transmission of the 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 a HE PPDU, the format of the instructed PPDU may be a HE PPDU. However, when the format of the PPDU including the TRS control subfield is an EHT PPDU, the format of the instructed PPDU may be an EHT PPDU.

[0242] Referring to FIG. 18, when the TRS is transmitted by a HE PPDU, the TB PPDU in response to the TRS may be a HE TB PPDU. Also, when the TRS is transmitted by an EHT PPDU, the TB PPDU in response to the TRS may be an EHT TB PPDU. Also, when the TRS is transmitted by a NEXT PPDU, the TB PPDU in response to the TRS may be a NEXT TB PPDU.

[0243] According to an embodiment of the present invention, based on the PPDU format including the TRS, sub-fields included in the TRS can be interpreted differently. For example, when the TRS is included in the HE PPDU, the UL HE-MCS sub-field (or the sub-field related to MCS) included in the TRS can indicate a value corresponding to the HE MCS table. When the TRS is included in the EHT PPDU, the UL HE-MCS sub-field (or the sub-field related to MCS) included in the TRS can indicate a value corresponding to the EHT MCS table. When the TRS is included in the NEXT PPDU, the UL HE-MCS sub-field (or the sub-field related to MCS) included in the TRS can indicate a value corresponding to the NEXT MCS table. Also, the RU Allocation sub-field may be interpreted differently based on the PPDU format including the TRS.

[0244] FIG. 19 shows an example of a PE (packet extension) field for providing a processing time according to an embodiment of the present invention.

[0245] 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 PPDU received by the receiving device.

[0246] Specifically, a receiving device that receives a PPDU can decode the PPDU, interpret the PPDU, and transmit a response thereto to the transmitting device. However, when the time for processing the PPDU increases due to a performance degradation of the receiving device or the like, there may be a case where the receiving device cannot transmit a response within the time for transmitting a response to the PPDU. Therefore, in order to secure such a time for processing, the PPDU may include a field that does not require decoding, which can be called a PE field.

[0247] Since the PE field does not require separate decoding, during the duration of the PE field, the receiving device can ensure the time for decoding and processing the PPDU, 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 receiving device, which is a terminal.

[0248] Therefore, the PE field may be located at the end of the PPDU or next to the data field to provide additional processing time. For example, it may be included in the PPDU in the order of preamble, data field, and PE field. The preamble and data field may be as described in the above embodiments. For the HE PPDU, the preamble may include L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF. For the EHT PPDU, the preamble may include L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-SIG, EHT-STF, EHT-LTF. The PPDU including the PE field may be a HE PPDU or an EHT PPDU, or a PPDU in a standard defined after the EHT standard.

[0249] If the PE field is not included in the PPDU, when the performance of the receiving device (e.g., STA) that receives it is not high, due to the time required to process the received PPDU, it may be difficult to respond to the already set time from the end of the received PPDU. The already set time may be after the IFS (inter - frame space) or SIFS (short inter - frame space) from the end of the received PPDU. Therefore, by positioning the PE field, which is a field that does not need to be decoded, at the end of the received PPDU, it is possible to ensure the time for processing the received PPDU. That is, by positioning the field that does not require decoding at the end of the PPDU, the PPDU can be processed fast enough. Therefore, it is possible to process the PPDU including the PE field and send an immediate response to it within the time limit. At this time, the immediate response may be sent after the SIFS from the end of the said PPDU including the PE field.

[0250] Also, the power for transmitting the PE field can be based on the power for transmitting the data field. For example, the power for transmitting the PE field may be the same as the average power for transmitting the data field.

[0251] The PE field may be transmitted including any content. Also, the position and size where the PE field is transmitted in the frequency domain may be the same as the data field or the resource unit (RU) where the data field is transmitted.

[0252] 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, 20 us. At this time, the maximum value of the duration of the PE field may vary depending on the format of the PPDU in which the PE field is included. For example, in the case of an HE PPDU, the duration of the PE field may be one of 0, 4, 8, 12, 16 us, and in the case of an EHT PPDU, it may be one of 0, 4, 8, 12, 16, 20 us. A PE field of 0 us corresponds to the absence of the PE field.

[0253] According to an embodiment, a PE field with a pre-set duration may be used only for a pre-set setting. For example, the pre-set duration may be 20 us or more. The pre-set duration may be based on an MCS (modulation and coding scheme) or a modulation method. That is, a PE field with a pre-set duration may be set according to a pre-set MCS index, MCS, or modulation method and included in the PPDU.

[0254] Alternatively, a PE field with a pre-set duration may be included in the PPDU for a pre-set MCS index, a pre-set modulation, or an MCS index, modulation, or MCS higher than the pre-set MCS. For example, the pre-set MCS index, the pre-set modulation, or the pre-set MCS may be based on 4096-QAM.

[0255] In addition to the MCS or modulation method, the pre-set value for the duration of the PE field may also be based on the number of spatial streams. For example, when a number of streams more than 8 spatial streams are used, the pre-set value for the duration of the PE field may be used.

[0256] Also, the already set value may be based on the transmitted channel width, bandwidth, or RU size. For example, when the channel width, bandwidth, or RU size is set to the already set value, the duration of the PE field may be determined to be a specific already set value.

[0257] According to one embodiment, the channel width or bandwidth may be a value corresponding to the transmitted PPDU. Or, the channel width, or bandwidth, may be a value corresponding to the PPDU transmitted by a plurality of STAs simultaneously or the entire PPDU. For example, when the channel width or bandwidth is 320 MHz, the use of a specific already set value as the duration value of the PE field of the PPDU may be allowed. For example, a duration of 20 us may be allowed to be used only when the channel width or bandwidth is 320 MHz.

[0258] According to other embodiments, the channel width or bandwidth for which the use of a specific value is allowed 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. That is, when using multiple RUs, it may be for the sum of the sizes of the plurality of RUs.

[0259] That is, the specific already set 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 the values 0 us, 4 us, 8 us, 12 us, 16 us, or 20 us as described above, and among these, the specific value may be used or set for the PPDU under the following conditions.

[0260] - A PPDU modulated using a 4096-QAM modulation method

[0261] - A PPDU transmitted using 8 or more spatial streams (in at least one RU / MRU)

[0262] - When the size of at least one assigned RU or MRU is 2×996 or more, a 320 MHz PPDU

[0263] - An EHT TB PPDU based on a trigger frame (i.e., the format of the PPDU indicated by the trigger frame),

[0264] For example, the duration of the PE field may be set to be different according to 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 a HE TB PPDU, the duration of the PE field of the HE TB PPDU may be set to one value among 0 us, 4 us, 8 us, 12 us, or 16 us. However, when the PPDU indicated by the frame is an EHT TB PPDU, the duration of the PE field of the HE TB PPDU may be set to one value among 0 us, 4 us, 8 us, 12 us, 16 us, or 20 us. That is, the values (e.g., the maximum value) that can be set as the duration of the PE field may be different according to the format of the PPDU indicated by the frame.

[0265] For example, as described above, 20 us may be allowed only under specific conditions.

[0266] For example, in the above description, the specific value that has already been set may be 20 us. That is, the PE field having a duration of 20 us may be allowed only under the specific conditions or in the specific cases described above.

[0267] FIG. 20 shows an example of a HE (High Efficiency) operation element and a default PE duration subfield according to an embodiment of the present invention.

[0268] Referring to FIG. 20, an AP STA (or, AP) can indicate the duration value of the PE field in an operation element.

[0269] Specifically, information related to the duration for the PE field of the PPDU may be included in and transmitted by the operation element. 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 can set the value of the control ID to a value indicating the TRS in order to trigger the transmission of the PPDU, and the non-AP STA can transmit a PPDU as a response to the PPDU of the TRS. At this time, the PPDU may include a PE field for providing the additional processing time described above, 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 operation element (e.g., the default PE duration field).

[0270] At this time, the duration of the PE field or the already set information related to the duration of the PE field can be referred to as the default PE duration, and the default PE duration may be indicated by a default PE duration subfield.

[0271] 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, the TRS may be used interchangeably with the TRS Control.

[0272] The operation element may include information related to the operation of the BSS, and may be a HE operation element or an EHT operation element depending on the format. Such operation elements may be included in and transmitted in a beacon frame, a probe request frame, a probe response frame, an association request frame, an association response frame, a re-association request frame, and a reassociation request frame.

[0273] The default PE duration subfield included in the operation element can indicate the duration of the PE field in a certain unit (or a pre-set unit). At this time, the certain unit or the pre-set unit may be 4 us. 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, if the value of the default PE duration subfield is "4", the duration of the PE field indicated by the default PE duration subfield may be 16 us.

[0274] Figure 20(a) is a diagram showing an example of a HE operation element. Referring to Figure 20(a), the HE operation element may include a HE operation parameter field (Operation Parameters field). Figure 20(b) is a diagram showing an example of the HE operation parameter field. Referring to Figure 20(b), the HE operation parameter field may include a default PE duration subfield. At this time, the default PE duration subfield may be 3 bits, and the 5-7 values may be reserved. That is, since the 5-7 values of the default PE duration subfield are reserved, only the 0-4 values may be valid values. Therefore, the durations that can be indicated by the default PE duration subfield may be 0, 4, 8, 12, 16 us. If the reserved value 5 is used, the default PE duration subfield may be indicated up to 20 us.

[0275] FIG. 21 shows an example of a method for setting the duration of the PE field according to an embodiment of the present invention.

[0276] Referring to FIG. 21, when a non-AP STA transmits a PPDU as a response to the AP's TRS, the non-AP STA can set the duration of the PE field of the PPDU to the default PE duration obtained from the AP.

[0277] Specifically, a terminal that has received a frame for triggering the transmission of a PPDU (for example, a frame including a control ID subfield having a value indicating a TRS or a trigger frame indicating the transmission of a PPDU) can include a PE field for providing additional processing time in the PPDU and transmit it. The PE field may be set in units of a fixed time or a previously set time unit (for example, 0 us, 4 us, 8 us, 12 us, 16 us, or 20 us). At this time, 20 us may be allowed to be used only in specific cases as described above.

[0278] The duration of the PE field may be set to a value indicated by the default PE duration field transmitted from the AP, where the default PE duration may be the same as that described above with reference to FIG. 20, and the same content as that described in FIG. 20 is omitted. The default PE duration field may be indicated by being included in the operation element and transmitted as described in FIG. 20.

[0279] That is, when a non-AP STA responds to the AP's TRS, the duration for the PE field of the PPDU can be determined based on the default PE duration transmitted and indicated from the AP. At this time, the PPDU may be a HE TB PPDU, an EHT TB PPDU, or a TB PPDU of a later version that is a PPDU based on a trigger frame, and the AP may be an AP associated with the non-AP STA.

[0280] As shown in FIG. 21, the STA can receive a trigger frame or a frame including a TRS control field for triggering or indicating the transmission of a PPDU, and can transmit a TB PPDU as a response thereto.

[0281] The TB PPDU may include a PE field to provide additional processing time, as described above with reference to FIGS. 19 and 20, and the duration of the PE field may be set in fixed time units. If the default PE duration is indicated to the STA by a default PE duration subfield from the AP, the STA can set the duration of the PE field to the indicated 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, etc.) transmitted from the AP. The STA (AP or AP STA) that transmitted the default PE duration and the STA (AP or AP STA) that transmitted the TRS control field may be the same STA.

[0282] If, when the STA receives a trigger frame from the AP and transmits a TB PPDU as a response thereto, the TB PPDU may include a PE field, and T, which is the duration of the PE field PE may be calculated by Equation 5 below.

[0283]

Equation

[0284] That is, in Equation 5

Equation

[0285] m is a value that varies depending on the format of the PPDU. For example, the value of m for the TB PPDU may be 2.

[0286] T PREAMBLE means the length of the preamble of the transmitted TB PPDU. When an HE TB PPDU is transmitted, T PREAMBLE may be the sum of the lengths of the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, HE-STF, and HE-LTF. When an EHT PPDU is transmitted, T PREAMBLE may be the length of the EHT preamble. That is, when an EHT TB PPDU is transmitted, T PREAMBLE may be the sum of the lengths of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-STF, and EHT-LTF.

[0287] N SYM can represent the number of data OFDM symbols included in the transmitted PPDU. For example, N SYM may be determined by Equation 7 below.

[0288]

Equation

[0289] In Equation 7, b PE_Disambiguity may be the value of the TXVECTOR parameter TB_PE_DISAMBIGUITY. Alternatively, b PE_disambiguity may be the value of the PE Disambiguity subfield included in the trigger frame. Also, the TXVECTOR parameter TB_PE_DISAMBIGUITY may be the TXVECTOR parameter HE_TB_PE_DISAMBIGUITY when transmitting a HE PPDU. The TXVECTOR parameter TB_PE_DISAMBIGUITY may be the TXVECTOR parameter EHT_TB_PE_DISAMBIGUITY when transmitting an EHT PPDU. Also, the PE Disambiguity subfield included in the trigger frame may be set based on whether it satisfies a preset equation.

[0290] T SYM may be the length of the OFDM symbol. Also, T SYM may be a value including the GI (guard interval).

[0291] N MA may be the number of midambles or the number of midamble periods. If the Doppler field is 0, N MA may be 0. Also, for an EHT PPDU, whether the Doppler field is 0 or N MAIt may be 0. The midamble may be inserted in the middle of the data field of the PPDU. Also, the midamble may be composed of a plurality of LTFs. The midamble may exist to assist the receiver's channel estimation.

[0292] N LTF may be the number of LTFs included in the preamble. At this time, the LTF may be a HE-LTF when transmitting a HE PPDU. Or, at this time, the LTF may be an EHT-LTF when transmitting an EHT PPDU.

[0293] T LTFSYM may be the length of the OFDM symbol of the LTF. At this time, the LTF may be a HE-LTF when transmitting a HE PPDU. Or, at this time, the LTF may be an EHT-LTF when transmitting an EHT PPDU. Also, T LTFSYM may be a value including the GI.

[0294] According to the described embodiment, when there is no midamble, T PE may be determined by the following Equation 8.

[0295] [Number]

[0296] As shown in FIG. 21, when the transmission of the TB PPDU is instructed by the trigger frame, the STA can transmit a PPDU including a PE field having a duration of T PE in response to the trigger frame.

[0297] If, for example, a frame including a TRS and a trigger frame for instructing transmission of a PPDU are included and transmitted together in one PPDU, the value of each field included in the trigger frame may be set so that the duration of the PE field included in the PPDU transmitted as a response thereto is the same as the default PE duration. For example, by adjusting (or setting) the values of the UL length subfield and the PE Disambiguity subfield of the trigger frame, the value of T PE can be the same as the default PE duration.

[0298] That is, when transmission of a PPDU is triggered by a trigger frame and a TRS, the duration of the PE field of the PPDU transmitted as a response thereto may be set to the value indicated by the default PE duration subfield. At this time, the value of the field for calculating T PE included in the trigger frame may be set so that the value of T PE is the same as the value indicated by the default PE duration subfield.

[0299] For example, when one PPDU includes a trigger frame and a TRS that respectively instruct different STAs to transmit TB PPDUs, the maximum value of the duration of the PE field included in the TB PPDU whose transmission is instructed only by the trigger frame may be 20 us (that is, when a PE field duration of 20 us is allowed), and the duration of the PE field included in the TB PPDU triggered by the TRS may have a maximum value of 16 us according to the default PE subfield. In this case, the value of the subfield (such as the LENGTH field and / or the PE Disambiguity subfield, etc.) for calculating T PE included in the trigger frame may be set so that the value of the duration according to the default PE subfield is the same as the value of T PE is the same.

[0300] 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 as one of the values of 0 us, 4 us, 8 us, 12 us, 16 us, or 20 us. However, the PPDU including the trigger frame also includes the TRS that instructs the transmission of the EHT TB PPDU, and the default PE duration sub-field for the EHT TB PPDU instructed by the TRS may be set to one of the values of 0 us, 4 us, 8 us, 12 us, or 16 us. At this time, 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.

[0301] In this case, the terminal whose transmission of the TB PPDU is triggered by the TRS can set the value indicated by the default PE duration included in the operating element as the duration of the PE field. However, the terminal whose transmission of the TB PPDU is triggered by the trigger frame can use the sub-fields (such as the LENGTH field and / or the PE Disambiguity sub-field, etc.) included in the trigger frame to calculate the T PE value and set it as the duration of the PE field included in the TB PPDU. At this time, the value of the sub-field for calculating the T PE value included in the trigger frame may be set so that the value is the same as the value indicated by the default PE duration and T PE value.

[0302] That is, when the maximum value for the duration of the PE field of the TB PPDU by the trigger frame that is included in one PPDU and triggers the transmission of the TB PPDU to different STAs respectively 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 and the value indicated by the default PE duration subfield are the same.

[0303] In this case, when the default PE duration subfield is set to one of the values of 0 us, 4 us, 8 us, 12 us, or 16 us (or 0 us, 4 us, 8 us, 12 us, 16 us or 20 us), T calculated by the trigger frame PE and the value indicated by the default PE duration subfield may be the same.

[0304] Therefore, according to the embodiments of the present invention, when including the TRS and the trigger frame that trigger the transmission of the TB PPDU to different STAs respectively in one PPDU, the duration of the PE field included in the PPDU transmitted as a response to the TRS and the duration of the PE field included in the PPDU transmitted as a response to the trigger frame may be the same. That is, in FIG. 21, T PE and the default PE duration may be the same value.

[0305] According to the foregoing embodiments, when responding to a TRS or responding to a trigger frame included in a PPDU including a TRS, a response is made including the PE field of a previously set duration. At this time, the previously set duration may be the default PE duration. Therefore, the AP can 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 a previously set setting. For example, the duration of the PE field of 20 us may be used only in a previously set setting. Therefore, when responding to a TRS or responding to a trigger frame included in a PPDU including a TRS, it may be necessary to set a default PE duration with a larger value in order to use the previously set setting. For example, it may be necessary to set the default PE duration to 20 us in order to use the previously set setting. In such a case, even if the previously set setting is not used, a long default PE duration has to be used, which can be redundant. That is, even for a PPDU of a setting that can be received without using a long PE field, a long PE field has to be included, which can lead to a waste of airtime.

[0306] Also, the maximum value among the values that the default PE duration subfield included in the HE operation element can indicate may be 16 us. Therefore, a problem may occur that it is difficult to trigger a setting that requires a PE field longer than that with a trigger frame included in a TRS or a PPDU including a TRS. If the reserved value of the default PE duration subfield included in the HE operation element is used, the HE STA that receives this cannot interpret it and cannot operate correctly.

[0307] A method for solving this in the following embodiments will be described.

[0308] FIG. 22 shows yet another example of a method for setting the UL MU operation and the duration of the PE field according to an embodiment of the present invention.

[0309] Referring to FIG. 22, in order to solve the problems described in FIG. 21, the value of the PE field of the PPDU triggered by the trigger frame or the TRS may be restricted.

[0310] Specifically, when triggering the response of the STA, it can be instructed to respond according to restricted settings. For example, when triggering using the TRS or using the trigger frame included in the PPDU including the TRS, it can be instructed to respond using restricted settings. Also, at this time, the method of instruction may include instructing in the subfield included in the TRS or the trigger frame. Also, at this time, the method of instruction may include implicitly instructing when responding to the TRS or the trigger frame included in the PPDU such as the TRS. Such restricted settings may be settings that do not require a PE field of a preset length. As an example, the preset length may be a length of 20 us or more. More specifically, the preset length may be a length of 20 us. As another example, the preset length may be a length greater than 16 us. Therefore, the STA responding to the trigger frame included in the PPDU including the TRS or the TRS can respond using restricted settings.

[0311] At this time, the duration of the PE field included in the responding PPDU may be smaller than the preset length. For example, at this time, the duration of the PE field included in the responding PPDU may be 16 us or less.

[0312] Also, 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 utilize 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.

[0313] 1) MCS or modulation

[0314] 2) Number of spatial streams

[0315] 3) Channel width, bandwidth, or RU size

[0316] Therefore, according to one embodiment, when transmitting a trigger frame included in a TRS or a PPDU including a TRS, it can be instructed to respond using the already set MCS index or an MCS index or modulation below the already set modulation. Or, when transmitting a trigger frame included in a TRS or a PPDU including a TRS, it may not be necessary to instruct to respond with 4096-QAM. Or, when transmitting a trigger frame included in a TRS or a PPDU including a TRS, it can be instructed to respond with an MCS that does not correspond to 4096-QAM.

[0317] Or, when transmitting a trigger frame included in a TRS or a PPDU including a TRS, it can be instructed to respond using a number of spatial streams equal to or less than the already set number. For example, the already set number may be 8.

[0318] Alternatively, when transmitting a trigger frame included in a TRS or a PPDU including a TRS, it can 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. Alternatively, the previously set size may be a 2×996 size (number of tones).

[0319] If a trigger frame is transmitted in a PPDU that does not include a TRS, it is not necessary to use the restricted settings as described.

[0320] Referring to FIG. 22, an AP can transmit a frame including TRS Control. Also, a trigger frame may be included in a PPDU including such a frame. At this time, the TRS Control and the trigger frame can indicate restricted settings. For example, it is not necessary to indicate a setting that requires a high capability at reception. Therefore, the PE field included in the EHT TB PPDU responding to the TRS Control and the EHT TB PPDU responding to the trigger frame may be 16 us or less. Therefore, resources are not wasted unnecessarily due to a long PE field.

[0321] FIG. 23 shows still another example of a method for setting UL MU operation and the duration of the PE field according to an embodiment of the present invention.

[0322] 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.

[0323] Specifically, for the TRS control including the TRS that instructs the transmission of the PPDU, the duration of the PE field of the PPDU can be indicated by the PE duration subfield. For example, a STA that responds to the TRS control field can determine the duration of the PE field included in the responding PPDU based on the PE duration subfield included in the TRS control field.

[0324] According to one embodiment, the PE duration subfield can indicate one value among 0, 4, 8, 12, 16, or 20 us. In such a case, the PE duration subfield may be 3 bits. In this case, there is an advantage that the duration of the PE field required each time the transmission of the PPDU is triggered by the TRS can be individually indicated. For example, the minimum required duration can be indicated.

[0325] According to still another embodiment, the PE duration subfield can indicate whether the use of the 20 - us PE field is allowed. 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, when 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, when the PE duration subfield included in the TRS control does not allow the use of the 20 - us PE field, the duration indicated by the default PE duration subfield included in the operation elements described in FIGS. 20 and 21 is set as the duration of the PE field and may be transmitted in the PPDU.

[0326] The 20 us duration of the PE field may be limited to be used only in EHT TB PPDUs. If responding with an HE TB PPDU, it is not possible to set the duration of the PE field to 20 us. At this time, whether the TB PPDU triggered for transmission by a TRS or a trigger frame is an EHT TB PPDU or an HE TB PPDU can be recognized based on the TB PPDU format signaling described in FIGS. 17 and 18, etc. 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.

[0327] TRS control may include signaling indicating whether a TRS control or a trigger frame including a TRS control that requires a 20 us PE field in the PPDU including the TRS control is included. If it is indicated that a TRS control or a trigger frame that requires a 20 us PE field is included, it is possible to respond using a PPDU including a 20 us PE field. If it is indicated that a TRS control or a trigger frame that requires a 20 us PE field is not included, the duration of the PE field may be set by the default PE duration.

[0328] According to still other embodiments, when responding to a TRS, it is always possible to respond with a PPDU including a PE field having a previously set duration. For example, the previously set duration may be 20 us. Also, this embodiment may be limited to the case of responding with an EHT TB PPDU. If responding with an HE TB PPDU, a 20 us PE field may not be used. That is, when responding with an EHT TB PPDU, a 20 us PE field is included and transmitted in the EHT TB PPDU, and when responding with an HE TB PPDU, a PE field set by the default PE duration may be included and transmitted in the HE TB PPDU.

[0329] In the described embodiments, 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 embodiments. For example, the UL length subfield and the PE Disambiguity subfield of the trigger frame included in the PPDU including the TRS can indicate values such that the duration of the PE field becomes the duration of the PE field indicated in the described embodiments. At this time, the duration of the PE field may be determined by T PE as described in FIG. 21.

[0330] Also, according to one embodiment, a plurality of TRSs included in one PPDU can indicate the same duration of the PE field. For example, a plurality of TRSs included in one PPDU may include PE duration subfields set to the same value. The plurality of TRSs may be included in a plurality of A-MPDUs of the PPDU.

[0331] 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 description of each subfield may be as described in FIGS. 18 to 23. Also, the PE duration subfield can indicate whether to respond with a 20 us PE field. In this case, the PE duration subfield may be 1 bit.

[0332] Referring to FIG. 23(b), the AP can transmit a PPDU including a frame containing a trigger frame or a TRS control field. Optionally, the PE duration subfield included in the TRS control field may be set to 0. The PE duration subfield set to 0 may indicate that 20 us is not used or that the default PE duration is to be used. Also, other PE duration subfields included in the PPDU including the PE duration set to 0 may also be set to 0. Also, the trigger frame included in the PPDU including the PE duration subfield set to 0 may be set such that the duration of the PE field of the 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) the PE duration subfield set to 0, 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 0 may be the default PE duration. Or, 1) the PE duration subfield set to 0, 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 0 may be 16 us or less. At this time, the responding PPDU may be an EHT TB PPDU. Or, optionally, when responding to a TRS or a trigger frame with an HE TB PPDU, the PE field of the default PE duration can be used.

[0333] Referring to FIG. 23(b), the AP can transmit a PPDU including a frame containing a trigger frame or 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 20 us is used or that the default PE duration is not used. Also, other PE duration subfields included in the PPDU including the PE duration subfield set to 1 may also be set to 1. Further, the trigger frame included in the PPDU including the PE duration subfield set to 1 may be set such 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 20 us. Or, 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 not be the default PE duration. At this time, the responding PPDU may be an EHT PPDU. Or, at this time, the responding PPDU may be an EHT TB PPDU. That is, it may be limited to the case of responding with an EHT TB PPDU.

[0334] FIG. 24 shows still another example of a method for setting the UL MU operation and the duration of the PE field according to an embodiment of the present invention.

[0335] Referring to FIG. 24, the duration of the PE field included in the TB PPDU is set to the value indicated by the PE duration field indicated by the TRS control field, or may be set to the value indicated by the default PE duration subfield included in the operating element. Alternatively, when the TB PPDU is triggered only by the trigger frame, the duration of the PE field of the TB PPDU may be set by 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 an HE TB PPDU is indicated)).

[0336] For example, 20 us may be allowed as the duration of the PE field only when the TB PPDU meets the aforementioned specific conditions (e.g., when an EHT PPDU (or an EHT MU PPDU, etc.) is indicated, when more than 8 spatial streams are used, or when the size of at least one RU is larger than 2×996, when the bandwidth for transmitting the EHT PPDU (or the like) is 320 MHz, or when the PPDU is modulated with 4096-QAM, etc.).

[0337] If the transmission of the PPDU is indicated by the TRS, the duration of the PE field included in the PPDU may be indicated by the default PE duration subfield included in the operating element (e.g., HE operating element or EHT operating element, etc.), or may be set to the value indicated by the PE duration subfield included in the TRS control field.

[0338] If, hypothetically, the TRS and the trigger frame are included in one PPDU and both are instructed to transmit the PPDU, and when the maximum value of the duration of the PE field when the PPDU is indicated by the trigger frame is the same as the maximum value of the duration of the PE field when indicated by the TRS, it may be set to the value indicated by the default PE duration subfield or the value indicated by the PE duration subfield included in the TRS.

[0339] However, if the TRS and the trigger frame are included in one PPDU and both are instructed to transmit the PPDU, the maximum value of the duration of the PE field when the PPDU is indicated by the trigger frame does not have to be the same as the maximum value of the duration of the PE field indicated by the default PE duration subfield when indicated by the TRS. For example, the TB PPDU indicated by the trigger frame and / or the TRS meets specific conditions, and the maximum value of the duration of the PE field is the first maximum value (for example, when 20 us is allowed), and the maximum value of the duration of the PE field indicated by the default PE subfield included in the operating element may be the second maximum value (for example, 16 us). In this case, the duration of the PE field may be set to the value indicated by the default PE subfield or the value indicated by the PE subfield included in the TRS.

[0340] At this time, the PE duration subfield can indicate that 20 us is allowed as the maximum value of the duration of the PE field, or can be instructed to set the duration of the PE field as the value of the default PE duration subfield included in the operating element.

[0341] In other words, according to an embodiment of the present invention, the duration of the PE field may be determined based on the PPDU format in response to the TRS. According to one 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 an HE TB PPDU. Or, the HE PPDU may be an HE SU PPDU. Also, the EHT PPDU may be an EHT TB PPDU. Or, the EHT PPDU may be an EHT MU PPDU. Also, the HE default PE duration may be the default PE duration described in FIGS. 20 and 21. For example, the HE default PE duration may be a value indicated by the HE operation element. More specifically, the HE default PE duration may be a value indicated by the default PE duration subfield included in the HE operation element.

[0342] Also, the EHT default PE duration may be a value indicated by the EHT operation element. More specifically, the EHT default PE duration may be a value indicated by the EHT default PE duration subfield included in the EHT operation element.

[0343] According to one embodiment, the EHT default PE duration subfield can indicate whether the duration of the PE field is 20 us. In this case, the EHT default PE duration subfield may be 1 bit.

[0344] According to other embodiments, 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 may be 1 bit. For example, when the EHT default PE duration subfield is indicated that the duration of the PE field is the same as the HE default PE duration, the EHT default PE duration may be the default PE duration indicated by the HE operation element. Also, when the EHT default PE duration subfield is indicated that the duration of the PE field is not the same as the HE default PE duration, the EHT default PE duration may be 20 us.

[0345] According to other embodiments, the EHT default PE duration subfield can indicate which value among 0, 4, 8, 12, 16, 20 us the duration of the PE field is. In this case, the EHT default PE duration subfield may be 3 bits.

[0346] According to still other embodiments, the EHT default PE duration may be 20 us.

[0347] Referring to FIG. 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 parameter field included in the HE operation element. FIG. 24(a) may be the same as FIG. 20(b).

[0348] Referring to FIG. 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.

[0349] Referring to FIG. 24(c), there may be cases of transmitting a HE PPDU and an EHT PPDU in response to TRS control. If transmitting a HE PPDU as a response, the duration of the PE field included in the HE PPDU may be the default PE duration. The default PE duration may be the value indicated in FIG. 24(a). Also, the default PE duration may be a value of 16 us or less. If transmitting an EHT PPDU as a response, the duration of the PE field included in the EHT PPDU may be the EHT default PE duration. The EHT default PE duration may be set based on the EHT operation element or the HE operation element. For example, the EHT default PE duration may be set to 1) a previously set value or 2) a value based on the default PE duration subfield included in the HE operation element, based on the EHT default PE duration subfield included in the EHT operation element. The previously set value may be 20 us. Referring to FIG. 24(c), when responding to TRS control with an EHT PPDU, a PPDU can be transmitted including a 20 us PE field.

[0350] According to an embodiment of the present invention, a plurality of PPDUs may be multiplexed in the frequency domain. Such a plurality of PPDUs can be referred to as an A-PPDU (aggregated PPDU). When the A-PPDU is transmitted, a plurality of PPDUs may be transmitted simultaneously. For example, an HE PPDU and an EHT PPDU can constitute an A-PPDU. More specifically, an HE TB PPDU and an EHT TB PPDU can constitute an A-PPDU. For example, a plurality of STAs can be triggered to transmit an A-PPDU composed of an HE TB PPDU and an EHT TB PPDU.

[0351] 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. At this time, the method of setting the duration may follow the method described in FIGS. 20 to 24. Thereby, the operation of the STA receiving the A-PPDU can be simplified.

[0352] As yet another example, when one STA transmits an A-PPDU composed of an HE PPDU and an EHT PPDU, the durations of the PE fields included may be the same. Thereby, a simple implementation becomes possible when constituting the A-PPDU.

[0353] According to an embodiment of the present invention, it is also possible to transmit a PPDU other than a TB PPDU in response to a trigger frame or a TRS. For example, an SU PPDU or an MU PPDU can be transmitted. For example, the MU PPDU may be an EHT MU PPDU or a HE MU PPDU. The SU PPDU may be a HE SU PPDU or a non-HT PPDU. According to an embodiment, the method for setting the duration of the PE field may be different based on whether to transmit a TB PPDU or a PPDU other than the TB PPDU in response to a trigger frame or a TRS. For example, when transmitting a TB PPDU, the duration setting method described in FIGS. 20 to 24 can be used. Also, when transmitting a PPDU other than the TB PPDU, the nominal PE duration can be set as the duration.

[0354] FIG. 25 shows an example of a method for setting the CS Required subfield according to an embodiment of the present invention.

[0355] Referring to FIG. 25, it is possible to perform CS (carrier sense) when responding to a trigger frame. For example, when receiving a trigger frame, 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 CCA (clear Channel assessment). For example, the physical CS performed when determining whether to respond to a trigger frame may be ED (energy detection). Also, virtual CS can mean considering the NAV. The CS performed when determining whether to respond to a trigger frame may be performed during (or within) the SIFS time from the end of the PPDU including the trigger frame (or after the PPDU).

[0356] According to an embodiment of the present invention, there may be signaling that instructs to determine whether to respond based on the 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 that instructs to determine whether to respond based on the CS result when responding to the 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 the trigger frame including the CS Required subfield.

[0357] For example, when the CS Required subfield is set to 1, if the CS result is busy when responding to the trigger frame including the CS Required subfield, it may not be necessary to respond to the trigger frame. When the CS Required subfield is set to 1, if the CS result is idle when responding to the trigger frame including the CS Required subfield, it may be possible to respond to the trigger frame. For example, when the CS Required subfield is set to 0, it is possible to determine whether to respond without depending on the CS result when responding to the trigger frame including the CS Required subfield. The CS result may be busy when at least one of the physical CS and the virtual CS is busy. The CS result may be idle when both the physical CS and the virtual CS are idle.

[0358] Also, when responding to the TRS control field, it is possible to determine whether to respond without depending on the CS result.

[0359] Also, the trigger frame included in the same PPDU as the TRS control field can set the CS Required subfield to 0 or 1. Or, the trigger frame included in the same PPDU as the frame including the TRS control field can set the CS Required subfield to 0 or 1.

[0360] As shown in FIG. 25, the trigger frame and the frame including TRS control may be transmitted in the same PPDU. At this time, the CS Required subfield included in the trigger frame may be set to 0. Therefore, it is possible to respond without depending on the CS result when responding to the trigger frame. Also, it is possible to respond without depending on the CS result when responding to the TRS control.

[0361] According to an embodiment of the present invention, the CS Required subfield may be set when transmitting the trigger frame. For example, the CS Required subfield may be set based on the length of the response indicated by the trigger frame. The UL length subfield shown in FIG. 16 can indicate the length of the response indicated by the trigger frame. The length of the TB PPDU responding to the trigger frame can 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 already set to a certain type. 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.

[0362] According to one embodiment, when the UL length subfield value is less than or equal to a preset value (smaller or equal), the CS Required subfield may be set to 0 or 1. As a more specific example, when the UL length subfield value is less than or equal to a preset value, the CS Required subfield may be set to 0. Also, when the UL length subfield value exceeds the preset value (larger), the CS Required subfield may be set to 1. When the UL length subfield value exceeds the preset value (larger), the CS Required subfield does not have to be set to 0.

[0363] According to one embodiment of the present invention, the preset value may be 418. For example, when the condition based on the UL Length subfield is used together with the following Condition 1 or Condition 2, the preset value may be 418.

[0364] (Condition 1) The RA (receiver address) of the trigger frame is the MAC address of the individually addressed STA, and the trigger frame is 1) a QoS Data frame with the Ack Policy set to respond with an acknowledgment for the TB PPDU (HETP Ack), or 2) aggregated into one A-MPDU with a Management frame that solicits an acknowledgment.

[0365] (Condition 2) The trigger frame is a MU-BAR or GCR MU-BAR trigger frame.

[0366] Condition 1 may be used together with the condition that the trigger frame is Basic, BSRP, MU-BAR, BQRP, or GCR MU-BAR.

[0367] The already set value 418 may be a value corresponding to a PPDU length of 584 us. Also, 584 us may be the maximum TB PPDU duration that can be indicated by TRS control. 584 us may be the maximum HE TB PPDU duration that can be indicated by TRS control. 584 us may be the sum of the lengths of the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, HE-STF, HE-LTF, Data field, and PE field of the TB PPDU. L-STF, L-LTF, L-SIG, and RL-SIG may be 8, 8, 4, and 4 us respectively. HE-SIG-A may be 8 us. HE-STF may be 8 us for the TB PPDU. HE-LTF is a TB PPDU that responds to TRS control and may be 16 us. 4x HE-LTF with a GI (guard interval) of 3.2 us may be 16 us. The maximum value of the Data field that can be indicated by TRS control may be the value of the maximum number of symbols with a 3.2 us GI. When the maximum number of symbols that can be indicated is 32 symbols, the maximum value of the Data field that can be indicated by 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 indicated by TRS control may be (8 + 8 + 4 + 4 + 8 + 8 + 16 + 512 + 16) us, i.e., 584 us.

[0368] 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 included in the same PPDU as the frame including TRS control 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 that is less than or equal to the maximum length that can be indicated by the TRS control, and since the UL length subfield value is already set to a value of 418 or less, it is possible to set the CS Required subfield to 0. The example shown in FIG. 25 may also set the CS Required subfield to 0 by the method described.

[0369] If the CS Required subfield of the trigger frame included in the same PPDU as the frame including TRS control is set to 1, the STA responding to the TRS control responds without relying on the CS result, and the STA responding to the trigger frame responds based on the CS result. Therefore, if the trigger frame cannot be responded to, it may lead to a result of wasting the resources allocated by the trigger frame.

[0370] According to another embodiment, the already set value may be 76. For example, when the condition based on the UL length subfield is used together with the following condition 1 or condition 2, the already set value may be 76.

[0371] (Condition 1) The trigger frame is a Basic, BSRP, MU-BAR, BQRP, or GCR MU-BAR trigger frame.

[0372] (Condition 2) The trigger frame is a BFRP trigger frame.

[0373] The already set value 76 may be a value corresponding to 128 us. Also, 128 us may be the duration of a HE TB PPDU having 4x HE-LTF and a PE field.

[0374] In an embodiment of the present invention, the already set value corresponding to Time us in length may be calculated by the following Equation 9 or Equation 10.

[0375]

Equation

[0376]

Equation

[0377] 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 signal extension. The length of signal extension may be 0 us in the 5 GHz band or 6 GHz band. The length of signal extension may be 6 us in the 2.4 GHz band.

[0378] FIG. 26 shows an example of the setting of the CS Required subfield and UL MU operation according to an embodiment of the present invention. The same content as that described in FIGS. 1 to 25 in FIG. 26 is omitted.

[0379] According to the above-described embodiment, there may be a case where it is instructed to respond with a trigger frame using a HE TB PPDU and a case where it is instructed to respond with an EHT TB PPDU. Also, there may be a case where the TRS control is instructed to respond with a HE TB PPDU and a case where it is instructed to respond with an EHT TB PPDU.

[0380] According to an embodiment of the present invention, the maximum TB PPDU duration that can be indicated by a TRS control field indicating an EHT TB PPDU response may be different from the maximum TB PPDU duration that can be indicated by a TRS control indicating an HE TB PPDU response. For example, the maximum TB PPDU duration that can be indicated by a TRS control indicating an EHT TB PPDU response may be longer than the maximum TB PPDU duration that can be indicated by a TRS control indicating an HE TB PPDU response. This is because, as described above, an EHT PPDU may include a 20 us PE field. Or, it is because the length indication method of the TRS control indicating an EHT TB PPDU response is different from that of the TRS control indicating an HE TB PPDU response.

[0381] Therefore, when indicating an EHT TB PPDU when setting the CS Required subfield based on the UL length subfield, using the same already set value (threshold) as described in FIG. 25 may lead to a result of wasted resources.

[0382] For example, when responding to a TRS control indicating an EHT TB PPDU response, it is possible to respond without relying on the CS result. The trigger frame may be included in the same PPDU as a frame including a TRS control that solicits an EHT TB PPDU response. In this case, the trigger frame and the TRS control indicating an EHT TB PPDU response can indicate the same response length.

[0383] At this time, as described in FIG. 25, the trigger frame can set the CS Required subfield based on a value based on the maximum HE TB PPDU length that can be instructed by TRS control. 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 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.

[0384] As shown in FIG. 26, the trigger frame can set the CS Required subfield to 1. Also, there may be TRS control included in the same PPDU as the trigger frame. At this time, the TRS control and the trigger frame can indicate an EHT TB PPDU. In this case, the STA responding to the TRS control responds with an EHT TB PPDU without depending on the CS result, and the STA responding to the trigger frame can determine whether to respond with an EHT TB PPDU based on the CS result. Therefore, the STA responding to the trigger frame may have a situation where the CS result is busy and it cannot respond. In this case, the resources allocated by the trigger frame may be wasted. Since a part of the resources is used for the response to the TRS control, it may become difficult for other STAs to utilize the resources.

[0385] FIG. 27 shows still other examples of the setting of the CS Required subfield and the UL MU operation according to an embodiment of the present invention.

[0386] The embodiment of FIG. 27 may be a method for solving the problems described in FIGS. 25 and 26. Also, in the embodiment of FIG. 27, the above-described content may be omitted.

[0387] According to an embodiment of the present invention, the already set value used when setting the CS Required subfield based on the UL length subfield described in FIGS. 25 and 26 may vary depending on which TB PPDU the trigger frame indicates. Or, the already set value used when setting the CS Required subfield based on the UL length subfield may vary depending on which TB PPDU the trigger frame indicates for the TRS control included in the same PPDU. According to an embodiment, when the trigger frame or the TRS control solicits an HE TB PPDU, the already set value may be threshold 1, and when the trigger frame or the TRS control solicits an EHT TB PPDU, the already set value may be threshold 2.

[0388] Or, according to an embodiment of the present invention, when indicating an HE TB PPDU, the already set value may be threshold 1. Also, the already set value can be determined by using both methods described in FIGS. 22 to 24. For example, when presenting an EHT TB PPDU and the PE duration is 16 us or less, the already set value may be threshold 1. When presenting an EHT TB PPDU and the PE duration is 20 us, the already set value may be threshold 2.

[0389] According to an embodiment, the threshold 1 may be the already set value described in FIG. 25. That is, the threshold 1 may be 418 or 76, and depending on the conditions described in FIG. 25, the already set value may be 418 or 76.

[0390] According to one embodiment, the threshold 2 may be a value greater than the threshold 1. This is because the maximum duration of the TB PPDU that can be indicated by the TRS control presenting the EHT TB PPDU is greater than the maximum duration of the TB PPDU that can be indicated by the TRS control presenting the HE TB PPDU. For example, the threshold 2 may be the same as the length value calculated by substituting the value of Time calculated by Equation 11 into Time in Equation 9 or Equation 10.

[0391]

Number

[0392] 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.

[0393] The EHT-LTF length may be 4x EHT-LTF length using a 3.2 us GI. Therefore, the EHT-LTF length may be 16 us.

[0394] The Data field length may be based on the maximum length that can be indicated by the TRS control presenting the EHT TB PPDU. For example, the Data field length may be based on the maximum number of OFDM symbols that can be indicated by the TRS control presenting the EHT TB PPDU. The Data field length may be based on the value obtained by multiplying the maximum number of OFDM symbols that can be indicated by the TRS control presenting the EHT TB PPDU by the OFDM symbol length. The Data field length may be based on the value obtained by multiplying the maximum number of OFDM symbols that can be indicated by the TRS control presenting the EHT TB PPDU by the maximum OFDM symbol length. The maximum number of OFDM symbols may be 32. The maximum OFDM symbol length may be the symbol length using a 3.2 us GI. The maximum OFDM symbol length may be 16 us. Therefore, the Data field length may be 32 * 16 us (512 us).

[0395] According to one embodiment, the maximum length that can be indicated for the TRS control for presenting an EHT TB PPDU may be the same as the maximum length that can be indicated for the TRS control for presenting an HE TB PPDU. The maximum length that can be indicated for the TRS control for presenting an EHT TB PPDU and the maximum number of OFDM symbols that can be indicated for the TRS control for presenting an HE TB PPDU may be the same. Thereby, an EHT STA can perform the same operations as an HE STA based on the TRS control, and thus, the implementation of the EHT STA can be facilitated.

[0396] According to other embodiments, the maximum length that can be indicated for the TRS control for presenting (solicit) an EHT TB PPDU and the maximum length that can be indicated for the TRS control for presenting an HE TB PPDU may be different. The maximum length that can be indicated for the TRS control for presenting an EHT TB PPDU and the maximum number of OFDM symbols that can be indicated for the TRS control for presenting an HE TB PPDU may be different. This is because the space for signaling that the TRS control may include is limited. For example, the TRS control for presenting an EHT TB PPDU may include signaling that is not included in the TRS control for presenting an HE TB PPDU. Therefore, the TRS control for presenting an EHT TB PPDU can define the maximum length that can be indicated or the resolution of the length that can be indicated to be different from that of the TRS control for presenting an HE TB PPDU.

[0397] According to one embodiment, the PE field length may be the maximum PE field length. The PE field length may be 20 us. According to other embodiments, the PE field length may be the PE field length by the method described in FIGS. 22 to 24. For example, the PE field length may be 16 us when using a PE field of 16 us or less by the method described in FIGS. 22 to 24. Also, the PE field length may be 20 us when using a PE field of 20 us by the method described in FIGS. 22 to 24.

[0398] Therefore, according to the described embodiments, the Time value may be as shown in Equation 12 below.

[0399]

Number

[0400] Also, in Equation 12, when substituting the Time value into Equation 10, threshold 2 may be 421.

[0401] When described in combination with the embodiment explained in FIG. 25, it is as follows. The trigger frame presenting the EHT TB PPDU can set the CS Required subfield to 1 when the UL length subfield is larger than threshold 2. Also, the trigger frame presenting the EHT TB PPDU can set the CS Required subfield to 0 or 1 when the UL length subfield is less than or equal to 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 explained in FIG. 25. For example, when the condition based on the UL length subfield is used together with the following Condition 1 or Condition 2, threshold 2 (for example, the value 421) can be used.

[0402] (Condition 1) The RA (receiver address) of the trigger frame is the MAC address of the individually addressed STA, and the trigger frame is 1) a QoS Data frame with the Ack Policy set to what should respond with an acknowledgment (HETP Ack) for the TB PPDU, or 2) aggregated into one A-MPDU with a Management frame indicating an acknowledgment.

[0403] (Condition 2) The trigger frame is a MU-BAR or GCR MU-BAR trigger frame.

[0404] Condition 1 may be used together with the condition that the trigger frame is a Basic, BSRP, MU-BAR, BQRP or GCR MU-BAR.

[0405] That is, when indicating an EHT TB PPDU under the condition of using the already set value of 418 when presenting an HE TB PPDU, the already set value of 421 can be used instead of 418.

[0406] According to another embodiment, the threshold 2 may be 79. The threshold 2 value of 79 may be a value corresponding to 132 us. The threshold 2 value of 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 4x EHT-LTF and a PE field.

[0407] When described in conjunction with the embodiment described in FIG. 25, it is as follows. For a trigger frame presenting an EHT TB PPDU, when the UL length subfield is greater than threshold 2, the CS Required subfield can be set to 1. Also, for a trigger frame presenting an EHT TB PPDU, when the UL length subfield is less than or equal to threshold 2, the CS Required subfield can be set to 0 or 1. 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., the value of 79) can be used when the condition based on the UL length subfield is used together with the following Condition 1 or Condition 2.

[0408] (Condition 1) The trigger frame is a Basic, BSRP, MU-BAR, BQRP, or GCR MU-BAR trigger frame.

[0409] (Condition 2) The trigger frame is a BFRP trigger frame.

[0410] That is, when presenting an EHT TB PPDU under the condition of using the already set value of 76 when presenting an HE TB PPDU, the already set value of 79 can be used instead of 76.

[0411] As shown in FIG. 27, the trigger frame may be transmitted included in the same PPDU as the frame including TRS control.

[0412] The trigger frame and TRS control included in the sequence labeled "Sequence 1" may be those that present an HE TB PPDU. Therefore, the PE field included in the HE TB PPDU presented at this time may be 16 us or less. Also, the trigger frame included in sequence 1 can set the CS Required subfield based on threshold 1. For example, the trigger frame included in sequence 1 can 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 trigger frame included in sequence 1 has a UL length subfield value less than or equal to threshold 1, the CS Required subfield can be set to 0 or 1. Therefore, it is possible to set the CS Required subfield to 0. If the trigger frame included in sequence 1 has a UL length subfield value greater than threshold 1, the CS Required subfield can be set to 1. For this reason, there may be cases where the CS Required subfield cannot be set to 0. Therefore, in the illustrated embodiment, neither the STA that responds to the TRS control nor the STA that responds to the trigger frame is based on the CS result, and if scheduled, it is possible to transmit a TB PPDU response.

[0413] The trigger frame and TRS control included in the sequence displayed as Sequence 2 may present an EHT TB PPDU. Therefore, the PE field included in the EHT TB PPDU presented at this time may be 20 us or less. Also, the trigger frame included in sequence 2 can set the CS Required subfield based on threshold 2. As a more specific example, the trigger frame included in sequence 2 can set the CS Required subfield based on threshold 2 when presenting a TB PPDU response including a 20 us PE field. If the trigger frame included in sequence 2 presents a TB PPDU response including a PE field of 16 us or less, the CS Required subfield can be set based on threshold 1. The following may be an example for the case of using threshold 2. For example, the trigger frame included in sequence 2 can 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 trigger frame included in sequence 2 has a UL length subfield value less than or equal to threshold 2, the CS Required subfield can be set to 0 or 1. Therefore, it is possible to set the CS Required subfield to 0. Therefore, 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 of threshold 2 or less, and thus, it is possible to set the CS Required subfield included in the trigger frame to 0. Therefore, as described in FIG. 26, since the STA responding to the TRS control transmits the TB PPDU without relying on the CS result and the STA responding to the trigger frame does not perform a TB PPDU response based on the CS result, the problem of resource waste can be solved.If the trigger frame included in sequence 2 can set the CS Required subfield to 1 when the UL length subfield value is greater than threshold 2. Therefore, there may be cases where the CS Required subfield cannot be set to 0. Thus, 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, without relying on the CS result.

[0414] According to other embodiments, the threshold 2 may be a value smaller than threshold 1. In this case, there is an advantage that it is possible to prevent the CS Required subfield from being unnecessarily set to 1 for short PPDUs or short frames. For example, when the maximum response length or the maximum number of OFDM symbols that can be indicated by the TRS control indicating an EHT TB PPDU is smaller than that of the TRS control indicating an HE TB PPDU, threshold 2 may be smaller than threshold 1. For example, when the maximum number of OFDM symbols that can be indicated by the TRS control presenting an EHT TB PPDU is 16, threshold 2 may be the same as the value obtained by substituting the next Time value into Equation 9 or Equation 10.

[0415] Time=8+8+4+4+8+8+16+16*16+16=328

[0416] Time=8+8+4+4+8+8+16+16*16+20=332

[0417] Therefore, threshold 2 may be 226 or 229.

[0418] FIG. 28 shows an example of a method for setting the PE field when using an A (aggregated)-PPDU according to an embodiment of the present invention.

[0419] As described with reference to FIG. 24, the PPDUs included in the A-PPDU may have the same duration in the PE field. Therefore, the duration of the PE field included in the EHT PPDU included in the A-PPDU may be 16 μs or less. More specifically, the duration of the PE field included in the EHT TB PPDU included in the A-PPDU may be 16 μs 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 value of the Default PE Duration subfield included in the HE Operation element.

[0420] To achieve this, when transmitting TRS control that indicates an EHT TB PPDU transmitted as (or constituting) an A-PPDU, the signaling that indicates the PE duration can be set to a value of 16 μs or less. Or, when transmitting TRS control that indicates an EHT TB PPDU transmitted as (or constituting) an A-PPDU, the signaling that indicates the PE duration can be set to use the value of the Default PE Duration subfield included in the HE Operation element as the duration of the PE field.

[0421] Or, when responding to TRS control that presents an EHT TB PPDU transmitted as (or constituting) an A-PPDU, the PE duration of the PE field to be transmitted can be set to a value of 16 μs or less. For this, the responding STA needs to know whether the TB PPDU transmission is transmitted as (or constitutes) an A-PPDU.

[0422] Or, the TRS control that indicates the EHT TB PPDU may not be included in the PPDU when indicating the A-PPDU. This is because there is no way for the responding STA to know whether it is responding to an A-PPDU. Also, this is because the TRS control does not include signaling that indicates the PE duration.

[0423] In the embodiment of FIG. 28, the same content as that described in FIGS. 1 to 27 may be omitted.

[0424] According to an embodiment of the present invention, 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 the A-PPDU, the already set value used when setting the CS Required subfield based on the UL length subfield described in FIGS. 25 to 27 may be different. That is, depending on whether a PPDU including the trigger frame indicating an EHT TB PPDU includes a frame indicating a HE TB PPDU, the already set value used when setting the CS Required subfield based on the UL length subfield may be different.

[0425] According to an embodiment of the present invention, when a trigger frame indicating an EHT TB PPDU is not included in the 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 the A-PPDU, the threshold 2 described in FIG. 27 can be used. More specifically, when a trigger frame indicating an EHT TB PPDU is not included in the A-PPDU, the CS Required subfield can be set based on the already set values of 421 or 79 described in FIGS. 25 to 27.

[0426] Also, when a trigger frame indicating an EHT TB PPDU is included in an A-PPDU, the methods described in FIGS. 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 FIG. 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 values of 418 or 76 described in FIGS. 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 values as in the case of a trigger frame indicating an HE TB PPDU.

[0427] Referring to FIG. 28, one frame included in one PPDU or a plurality of frames included in one PPDU can indicate an A-PPDU. For example, an HE TB PPDU and an EHT TB PPDU can be indicated simultaneously. For example, referring to sequence 1, a PPDU may include a TRS control indicating an HE TB PPDU and a TRS control indicating an EHT TB PPDU. In this case, the PE fields of the PPDU responding to the TRS control indicating the HE TB PPDU and the PPDU responding to the TRS control indicating the EHT TB PPDU may have the same duration. The same duration may be a length of 16 us or less. Or, the same duration may be the value indicated by the Default PE duration subfield included in the HE Operation element.

[0428] Referring to Sequence 2, the trigger frame can solicit the EHT TB PPDU that constitutes the A-PPDU. In this case, when setting the CS Required subfield included in the trigger frame, it can be based on threshold 1 described in FIG. 27. The threshold 1 may be a previously 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 can 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 can set the CS Required subfield based on the same previously 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 can set the CS Required subfield to the same value. Also, when the trigger frame indicating the EHT TB PPDU sets the CS Required subfield based on threshold 1 when transmitted together with the TRS control indicating the HE TB PPDU, it is possible to set the CS Required subfield to 0 or 1. That is, it is possible to set the CS Required subfield to 0. Therefore, among the A-PPDUs presented according to the embodiments of the present invention, it is possible to prevent a situation where the HE TB PPDU is transmitted without depending on the CS result and the EHT TB PPDU determines whether to respond based on the CS result.

[0429] FIG. 29 shows an example of a method for indicating the format of the TB PPDU according to an embodiment of the present invention.

[0430] As described in the above embodiments, it may be necessary to have a method in which the format of the PPDU to respond is indicated by a frame that triggers the PPDU. For example, the PPDU format may mean the TB PPDU format. The embodiment of FIG. 29 may be a specific embodiment of the above-described TB PPDU format indication method. Also, in this embodiment, the above-described content may be omitted.

[0431] According to an embodiment of the present invention, based on the User Info field included in the trigger frame, the format of the PPDU that responds to the trigger frame can be determined. Alternatively, the format of the PPDU that responds to the trigger frame can be indicated by the User Info field included in the trigger frame. In the present invention, the User Info field that determines and indicates the format of the PPDU can be called the Special User Info field.

[0432] According to one embodiment, the Special User Info field may be a User Info field set to a value in which the AID12 subfield included in the Special User Info field has already been set. For example, the already set value may be 2007. Also, the already set value may be a value that the AP does not assign as an AID (association ID). Further, the Special User Info field may have a different format from other User Info fields. That is, the Special User Info field may have different subfields included compared to other User Info fields. Also, the Special User Info field and other User Info fields may commonly include the AID12 subfield at the same position. For example, the Special User Info field and User Info fields other than the Special User Info field may have the first 12 bits as the AID12 subfield. For example, the Special User Info field and User Info fields other than the Special User Info field may have B0 to B11 as the AID12 subfield.

[0433] Also, the trigger frame may include a subfield indicating whether it includes the Special User Info field. The subfield indicating whether it includes the Special User Info field can be called the Special User Info Field Present subfield. For example, the Special User Info Field Present subfield may exist 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. Also, 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 an already set value.

[0434] The STA that receives the trigger frame can determine whether the Special User Info field is included based on the Special User Info Field Present subfield. Therefore, compared with the case where the Special User Info Field Present subfield does not exist, it may be easier to implement the determination of whether to include the Special User Info field. Also, when the trigger frame is received by an STA that is not associated with the AP that sent the trigger frame, the AID12 subfield can determine whether the User Info field set to a pre-set value indicating the Special User Info field is the Special User Info field (whether it actually indicates the 12 LSBs of the AID) based on the Special User Info Field Present subfield. For example, when indicating the RA-RU for an unassociated STA, when the trigger frame is received by an STA that is not associated with the AP that sent the trigger frame, it can operate based on the trigger frame. Also, the STA can perform a spatial reuse operation based on a trigger frame or a TB PPDU from a BSS with which it is not associated.

[0435] Also, when the trigger frame includes the Special User Info field, the Special User Info field may be located at the very front of the User Info field. Alternatively, the Special User Info field may be located immediately after the Common Info field. This may be for the purpose of enabling the STA that receives the trigger frame to easily parse the Special User Info field.

[0436] According to an embodiment of the present invention, based on whether the trigger frame includes a Special User Info field, the format of the PPDU responding to the trigger frame can be determined. For example, when the trigger frame includes a Special User Info field, the format of the PPDU responding to the trigger frame may be an EHT TB PPDU. Also, when the trigger frame does not include a Special User Info field, the format of the PPDU responding to the trigger frame may be a HE TB PPDU. Also, as described above, there may be a Special User Info Field Present subfield which is signaling indicating whether the trigger frame includes a Special User Info field. Therefore, it can also be said that based on the Special User Info Field Present subfield, the format of the PPDU responding to the trigger frame can be determined. For example, when the Special User Info Field Present subfield is set to 0, the format of the PPDU responding to the trigger frame may be an EHT TB PPDU. Also, when the Special User Info Field Present subfield is set to 1, the format of the PPDU responding to the trigger frame may be a HE TB PPDU.

[0437] Also, 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. Also, 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 a HE variant User Info field.

[0438] When the User Info field is in the EHT variant or the HE variant, the RU indication method may be different. For example, the interpretation method of the User Info field may vary depending on whether the RU Allocation subfield included in the User Info field is in the EHT variant or the HE variant. For example, the RU Allocation subfield included in the EHT variant User Info field may be encoded to indicate the RUs supported by the EHT standard. Also, the RU Allocation subfield included in the HE variant User Info field may be encoded to indicate the RUs supported by the HE standard.

[0439] Also, when interpreting the RUs indicated based on the EHT variant User Info field, it is necessary to be based on two or more subfields. The two or more subfields may include the RU Allocation subfield and the 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 can indicate in which subchannel the RU indicated by the RU Allocation subfield exists. Or, the PS160 subfield can indicate in which subchannel the RU indicated by the User Info field exists. At this time, the unit indicating which subchannel it is may be a 160 MHz subchannel. The PS160 subfield can indicate whether the RU to be indicated exists in the primary 160 MHz channel or the secondary 160 MHz channel. The PS160 subfield may exist 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.

[0440] Also, when interpreting the RU indicated based on the HE variant User Info field, it can be based on one subfield. The one subfield may be the RU Allocation subfield. That is, based only on the RU Allocation subfield included in the HE variant User Info field, the position of the RU indicated by the HE variant User Info field can be determined.

[0441] Referring to FIG. 29, the trigger frame may include a Special User Info field. Whether the User Info field is the Special User Info field may be determined based on the AID12 subfield included in the User Info field. For example, when the AID12 subfield included in the User Info field is a preset value, the User Info field may be the Special User Info field. Referring to FIG. 29, the preset value may be 2007. Also referring to FIG. 29, the Special User Info field may be located immediately after the Common Info field and at the very front of the User Info fields. Also, there may be a Special User Info Field Present subfield which is signaling indicating whether the trigger frame includes the 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 the Special User Info field. As shown in FIG. 29, when the trigger frame includes the Special User Info field, the response PPDU format therefor may be the EHT TB PPDU.

[0442] Also, according to an additional embodiment, based on whether the trigger frame includes a Special User Info field and a subfield indicating the TB PPDU format, the format of the PPDU responding to the trigger frame can be determined. 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 to respond with an HE TB PPDU. Also, when the HE / EHT P160 subfield value is 0, it may indicate to respond with an EHT TB PPDU. The HE / EHT P160 subfield may be 1 bit.

[0443] Referring to FIG. 29, the HE / EHT P160 subfield may be included in the Common Info field. More specifically, the HE / EHT P160 subfield may be included at bit position B55 of the Common Info field.

[0444] Therefore, when instructing and determining the TB PPDU format based on the Special User Info field and the HE / EHT P160 subfield, the following operations can be performed. When the HE / EHT P160 subfield indicates an EHT TB PPDU, it is possible to respond with an EHT TB PPDU when responding to a trigger frame. That is, when the HE / EHT P160 subfield indicates an EHT TB PPDU, it is possible to respond with an EHT TB PPDU regardless of the assigned RU position when responding to a trigger frame. Also, when the HE / EHT P160 subfield indicates an EHT TB PPDU, the Special User Info field may always be included. That is, the Special User Info Field Present subfield can also indicate that the Special User Info field is included.

[0445] If the HE / EHT P160 subfield indicates an HE TB PPDU, when responding to a trigger frame, the TB PPDU format can be indicated and determined based on the allocated RU position. When the HE / EHT P160 subfield indicates an HE TB PPDU, if it includes an RU allocated to a pre-configured channel (e.g., the P160 channel) indicated by the HE / EHT P160 subfield, it can respond with an HE TB PPDU. Also, when the HE / EHT P160 subfield indicates an HE TB PPDU, if it does not include an RU allocated to a pre-configured channel (e.g., the P160 channel) indicated by the HE / EHT P160 subfield (e.g., if it includes an RU allocated to a secondary 160 MHz channel (S160 channel)), it can respond with an EHT TB PPDU. Also, whether it includes an RU allocated to a pre-configured channel or not can be obtained based on the RU Allocation subfield and the PS160 subfield. More specifically, when the pre-configured channel is the P160 channel, whether it includes an RU allocated to the pre-configured channel or not can be obtained based on the PS160 subfield.

[0446] Also, the instruction and determination of the TB PPDU format based on the HE / EHT P160 subfield and the assigned RU position may be limited to the case where the trigger frame includes the Special User Info field. When 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 to include the Special User Info field may be based on the Special User Info Field Present subfield. Therefore, when the trigger frame includes the Special User Info field and when it does not include the Special User Info field as described above can respectively 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 is set not to include the Special User Info field.

[0447] In the present invention, the description of instructing and determining to use the EHT TB PPDU when responding to the trigger frame may be replaced by an invention that instructs and determines to use the EHT TB PPDU or the NEXT TB PPDU. Also, which of the EHT TB PPDU or the NEXT TB PPDU to use 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.

[0448] The Special User Info field may include information necessary when responding to the AID12 subfield and the trigger frame. The information necessary when responding to the trigger frame may include the information contained in the preamble of the PPDU that responds to the trigger frame. For example, the information necessary when responding to the trigger frame may include the information contained in the U-SIG field of the PPDU that responds to the trigger frame. FIG. 29 may include an example of the information contained in the U-SIG field. Referring to FIG. 29, the Special User Info field may include the AID12, PHY Version ID, UL Bandwidth Extension, Spatial Reuse 1, Spatial Reuse 2, U-SIG Disregard And Validate, Reserved, Trigger Dependent User Info fields. Also, the mentioned fields may exist in the mentioned order. Also, each of the mentioned fields may have 12, 3, 2, 4, 4, 12, 3, variable number of bits. The PHY Version ID field may be the Format Identifier subfield or the PHY version identifier subfield or the PHY version field described above. The STA that responds to the trigger frame can set the U-SIG field included in the responding PPDU based on the Special User Info field included in the trigger frame. For example, the subfield values included in the Special User Info field can be copied to the subfields included in the responding U-SIG field. The subfields to be copied to the subfields included in the U-SIG field may be the PHY Version ID, Spatial Reuse 1, Spatial Reuse 2, U-SIG Disregard And Validate subfields.

[0449] Alternatively, based on the sub-field values included in the Special User Info field, the sub-fields included in the U-SIG field of the responding PPDU can be set. The sub-field for setting the U-SIG field based on the sub-fields included in the Special User Info field may be the UL Bandwidth Extension sub-field. For example, based on the UL Bandwidth Extension sub-field included in the Special User Info field and the UL BW sub-field included in the Common Info field (see FIG. 16), the bandwidth (BW) sub-field included in the U-SIG field of the responding PPDU can be set.

[0450] Also, the presence and length of the Trigger Dependent User Info field included in the Special User Info field can 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 can be based on which variant the trigger frame is. The type of the trigger frame may be indicated and determined by the Trigger Type sub-field included in the Common Info field (see FIG. 16).

[0451] FIG. 30 is a diagram showing an STA, a TX VECTOR, and an RX VECTOR according to an embodiment of the present invention.

[0452] According to an embodiment of the present invention, a station may be a logical entity including a MAC (medium access control) and a PHY (physical layer). The station may be a logical entity including a singly addressable MAC and PHY one by one. Alternatively, the station may be an entity providing PHY and MAC functions (services). Also, the PHY may be a physical layer interface to a wireless medium. Also, the MAC may be in contact with the link layer.

[0453] The MAC may be referred to as the MAC layer. The PHY may be referred to as the physical layer or the PHY layer.

[0454] Also, the MAC and the PHY may be connected via an interface. The interface may include TXVECTOR, RXVECTOR, PHYCONFIG_VECTOR, and TRIG_VECTOR.

[0455] The MAC can transmit per-PPDU transmission parameters to the PHY using a TXVECTOR. Specifically, when a station transmits a PPDU, the MAC can transmit parameters related to the transmission of the PPDU to the PHY using the TXVECTOR. The parameters included in the TXVECTOR can be called TXVECTOR parameters. The TXVECTOR can be a vector including TXVECTOR parameters. The PHY can transmit a PPDU based on the received TXVECTOR parameters. For example, the PHY can encode and transmit a PPDU according to the TXVECTOR parameters. Also, the PHY can set the value of the field included in the preamble of the PPDU based on the TXVECTOR parameters. Also, the types of TXVECTOR parameters included in the TXVECTOR may vary according to the PHY format used. The TXVECTOR may be included in the PHY-TXSTART, request primitive.

[0456] The PHY can transmit the parameters of the received PPDU to the MAC using an RXVECTOR. Specifically, the PHY can transmit the parameters obtained from the PPDU when the station receives the PPDU to the MAC using the RXVECTOR. The parameters included in the RXVECTOR can be called RXVECTOR parameters. The RXVECTOR can be a vector including RXVECTOR parameters. For example, the PHY can set the RXVECTOR parameters based on the field included in the preamble of the received PPDU and transmit the RXVECTOR to the MAC. Also, the types of RXVECTOR parameters included in the RXVECTOR may vary according to the PHY format used. The RXVECTOR may be included in the PHY-RXSTART.indication primitive, PHY-RXEND.indication primitive.

[0457] The TXVECTOR parameter or the RXVECTOR parameter may include at least any one of FORMAT, EHT_PPDU_TYPE, L_LENGTH, L_DATARATE, RSS, MCS, CH_BANDWIDTH, INACTIVE_SUBCHANNELS, PSDU_LENGTH, TXOP_DURATION, and SPATIAL_REUSE, RU_ALLOCATION, TRIGGER_METHOD, BSS_COLOR, UPLINK_FLAG, and STA_ID. FORMAT can indicate the format of the PPDU. EHT_PPDU_TYPE can indicate whether the EHT PPDU is transmitted by DL OFDMA transmission, transmitted by single-user transmission, or is a sounding NDP. L_LENGTH can indicate the value used to calculate the value of the Length field of the L-SIG field. L_DATARATE can indicate the data rate of the PPDU. FEC_CODING can indicate the FEC encoding method. Specifically, FEC_CODING can indicate whether BCC coding is used or LDPC coding is used. RSSI can indicate the RSSI of the signal including the PPDU. MCS can indicate the modulation and coding scheme of the data field of the PPDU. CH_BANDWIDTH can indicate the channel bandwidth of the PPDU. INACTIVE_SUBCHANNELS can indicate the punctured subchannels. At this time, INACTIVE_SUBCHANNELS can indicate the subchannels punctured in units of 20 MHz. PSDU_LENGTH can indicate the number of octets of the PSDU. NUM_STS can indicate the number of spatial streams. TXOP_DURATION can indicate the TXOP duration. SPATIAL_REUSE can indicate the spatial reuse (SR) parameter. SPATIAL_REUSE can indicate at least any one of whether spatial reuse is allowed, the degree to which spatial reuse is allowed, and the values required for setting when using spatial reuse.RU_ALLOCATION can indicate the composition of the RU or MRU (multiple RU) where the PPDU is transmitted. BSS_COLOR can indicate the BSS color of the BSS to which the station transmitting the PPDU belongs. TRIGGER_METHOD can indicate how the transmission of the TB PPDU is indicated. Specifically, TRIGGER_METHOD can indicate whether the transmission of the TB PPDU is triggered by a trigger frame or by the TRS Control subfield. UPLINK_FLAG can indicate whether the PPDU is transmitted by the AP. STA_ID can indicate a list including the IDs of the stations that receive the PPDU.

[0458] In FIG. 30, a station (STA) may include a MAC and a PHY. The MAC can transmit a TXVECTOR to the PHY. The PHY can transmit a PPDU based on the TXVECTOR. Also, the PHY can receive a PPDU. The PHY can set an RXVECTOR based on the received PPDU. The PHY can transmit the RXVECTOR to the MAC. The MAC can operate based on the RXVECTOR.

[0459] FIG. 31 shows a frame format and a field format according to an embodiment of the present invention.

[0460] (a) of FIG. 31 shows the format of a MAC frame. The MAC frame may include a MAC header, a Frame Body, and an FCS. Also, the MAC header may include a Frame Control field, a Duration / ID field, a MAC address field, a Sequence Control field, a QoS Control field, and an HT Control field. The Frame Control field can indicate the type and subtype of the frame with a Type field and a Subtype field, respectively. Also, the Frame Control field can indicate whether the frame includes an HT Control field with a +HTC subfield. The Duration / ID field can indicate a duration value. When the frame is not a PS-Poll frame, the Duration / ID field can indicate a duration value. Also, a station that receives a MAC frame can set a NAV (network allocation vector) based on the duration value. The Duration / ID field can indicate an ID, such as an AID. When the frame is a PS-Poll frame, the Duration / ID field can indicate an ID. Also, the MAC address field may include one or more address fields. The Address field can indicate a MAC address. Also, the address field may include at least one of a BSSID (basic service set identifier) field, an SA (source address) field, a DA (destination address) field, a TA (transmitting STA address or transmitter address) field, and an RA (receiving STA address or receiver address (RA)) field. Also, the Sequence Control field can indicate a fragment number or a sequence number.Also, the QoS Control field can indicate at least one of the TID of the data included in the MAC frame, the Ack policy, the TXOP limit, and the buffer state and queue size. Further, the QoS Control field may further include the aforementioned RDG / More PPDU subfield and AC Constraint subfield. Specifically, the QoS Control field included in the DMG PPDU may further include the RDG / More PPDU subfield and AC Constraint subfield.

[0461] The HT Control field may further include the aforementioned RDG / More PPDU subfield and AC Constraint subfield. The RDG / More PPDU subfield can signal whether a PPDU including the RDG / More PPDU subfield includes an RDG or whether there is a subsequent PPDU following the PPDU including the RDG / More PPDU subfield.

[0462] The AC Constraint subfield can indicate whether the TID or AC transmitted by the MAC frame is restricted.

[0463] The HT Control field may be a 4-octet, 32-bit field.

[0464] The length of the MAC header and the fields included in the MAC header may have a predefined length.

[0465] The Frame Body field may include the content of the frame. Specifically, the Frame Body field may include information corresponding to the frame type and subtype.

[0466] The FCS field may include an FCS (frame check sequence). The value of the FCS field is used for both the MAC header and the Frame Body field, and may be used to check whether the MAC header and the Frame Body field contain error values.

[0467] Figure 31(b) shows the format of the HT Control field. As described above, the HT Control field may include an AC Constraint subfield and an RDG / More PPDU subfield.

[0468] The HT Control field may include bits B0 to B31. At this time, each of bits B30 and B31 may be an AC Constraint subfield and an RDG / More PPDU subfield. At this time, the HT Control field may be an HT variant or a VHT variant. The HT Control field may have multiple variants. For example, the HT Control field may be an HT variant, a VHT variant, an HE variant, an EHT variant, or a variant of a standard after EHT. The HE variant described in this specification may be a variant of a standard after HE. Also, the HT Control field may include signaling indicating which variant the HT Control field is. For example, some bits of the HT Control field can indicate which variant the HT Control field is. For example, when the value of bit B0 is 0, the HT Control field may be an HT variant. Also, when the value of bit B0 is 1, the HT Control field may be any one of a VHT variant, an HE variant, or an EHT variant. Also, when the value of bit B0 is 1 and the value of bit B1 is 0, the HT Control field may be a VHT variant. Also, when the value of the B0 field is 1 and the value of the B1 field is 1, it may be an HE variant or an EHT variant. Or, when the value of bit B0 is 1 and the value of bit B1 is 1, the HT Control field may be an HE variant, an EHT variant, or a variant of a standard after EHT.

[0469] According to one embodiment, when the HT Control field is a HE variant, an EHT variant, or a variant of a standard after EHT, the HT Control field may include an A-Control subfield. A-Control can mean aggregated control. The A-Control subfield may include one or more control information. For example, bits B2 to B31 of the HT Control field may be the A-Control subfield.

[0470] Figure 31(c) shows the format of the A-Control subfield in Figure 31(b). Referring to Figure 31(c), the A-Control subfield may include a Control List subfield and a Padding subfield. The Control List subfield may include one or more control information. Also, the Control List subfield may include one or more Control subfields. Also, the Padding subfield may or may not be included in the A-Control subfield. For example, the remainder obtained by subtracting the length of the Control List subfield from the length of the pre-specified A-Control subfield may be the length of the Padding subfield. In a specific embodiment, the Padding subfield may be set to a pre-set value. Or, the Padding subfield may have a pre-specified number of start bits set to a pre-set value.

[0471] (d) of FIG. 31 shows the format of the Control subfield mentioned in (c) of FIG. 31. In the example of (d) of FIG. 31, the Control subfield may include a Control ID subfield and a Control Information subfield. The Control ID subfield can indicate whether the content in the Control Information subfield is included, or what control information the Control subfield containing the Control ID subfield includes. Also, the station can determine the length of the Control Information subfield based on the value of the Control ID subfield. The Control ID subfield may be a 4-bit field. The information that the Control subfield may include may include the above-mentioned TRS (triggered response scheduling) Control subfield. The Control subfield may include a TRS field, which is information for triggering the response of the station that received the Control subfield. The value of the Control ID corresponding to the TRS field may be 0. Also, the Control subfield may include information regarding the operating mode (OM). The value of the Control ID corresponding to the OM may be 1. Also, the Control subfield may include information regarding link adaptation. The value of the Control ID corresponding to the link adaptation information may be 2. Also, the Control subfield may include information regarding the buffer, BSR (buffer status report). The value of the Control ID corresponding to the BSR may be 3. Also, the Control subfield may include information regarding the UL power headroom. The information regarding the UL power headroom may indicate how much more margin there is in the transmitable power, or may be a value used for power pre-correction. The value of the Control ID corresponding to the UL power headroom may be 4.In addition, the Control subfield may include signaling indicating the state of the subchannel and a BQR (bandwidth query report). The value of the Control ID corresponding to the BQR may be 5. The BQR may be signaling indicating whether the subchannel is available. Also, the Control subfield may include information regarding CAS (command and status CAS). The value of the Control ID corresponding to the CAS may be 6.

[0472] Figure 31(e) shows the Control Information subfield corresponding to the TRS mentioned in Figure 31(d). Figure 31(e) shows the corresponding Control Information subfield when the value of the Control ID subfield included in the Control subfield is 0. The TRS Control subfield includes the TRS, and in this specification, the TRS Control subfield, TRS Control, TRS, and TRS information may be used interchangeably. Referring to Figure 31(e), the TRS Control may include a UL Data Symbols subfield, a RU Allocation subfield, an AP Tx Power subfield, a UL Target Receive Power subfield, a UL MCS subfield, and a Reserved subfield. Also, the mentioned subfields may be 5 bits, 8 bits, 5 bits, 5 bits, 2 bits, and 1 bit respectively, and may be arranged in the order shown in Figure 31(e).

[0473] TRS Control may include information that triggers the transmission of a TB PPDU. The TB PPDU may include a HE TB PPDU, an EHT TB PPDU, or a NEXT TB PPDU. A station that receives TRS Control can transmit a TB PPDU based on the TRS Control received by the station. For example, after a station receives a PPDU that includes TRS Control, the station can immediately transmit a TB PPDU. At this time, "immediately" can indicate "after SIFS from receiving the PPDU". An AP can transmit TRS Control. Also, when a non-AP station receives TRS Control, the station can transmit a TB PPDU in response to the TRS control.

[0474] The UL Data Symbols subfield can indicate the number of OFDM symbols included in the Data field of the TB PPDU transmitted in response to TRS Control. For example, the value of the UL Data Symbols subfield may be set to a value obtained by subtracting 1 from the number of the OFDM symbols. At this time, when a station transmits a TB PPDU in response to TRS Control, the station can set the number of OFDM symbols in the Data field included in the TB PPDU to a value obtained by adding 1 to the value of the UL Data Symbols subfield included in the TRS Control.

[0475] The RU Allocation subfield can indicate the RU (resource unit) used when a station responds to TRS Control.

[0476] The AP Tx Power subfield can indicate the transmit power when the station transmits a PPDU including the AP Tx Power subfield. At this time, the transmit power may be indicated in units of dBm / 20MHz. Also, the AP Tx Power subfield can indicate the combined transmit power at the transmit antenna connectors of all antennas. For example, the value of the transmit power indicated by the AP Tx Power subfield may be (-20 + 2*(the value of the AP Tx Power subfield)) in units of dBm / 20MHz.

[0477] The UL Target Receive Power subfield can indicate the expected receive signal power of the AP. The UL Target Receive Power subfield can indicate the average expected receive signal power for multiple antennas measured at the antenna connectors of the AP. Also, the UL Target Receive Power subfield can indicate the signal power measured in the RU allocated after the RL-SIG field. For example, the UL Target Receive Power subfield can indicate the expected receive signal power in the allocated RU for the HE portion and the EHT portion for the HE TB PPDU and the EHT TB PPDU, respectively.

[0478] The UL MCS subfield can indicate the MCS to be used when transmitting a TB PPDU in response to a TRS Control that includes the UL MCS subfield. The UL MCS subfield can indicate the standard MCS index corresponding to the format of the TB PPDU transmitted in response to a TRS Control that includes the UL MCS subfield. For example, when responding to a TRS Control with an HE TB PPDU, the UL MCS subfield included in the TRS Control can indicate the HE MCS index. When responding to a TRS Control with an EHT TB PPDU, the UL MCS subfield included in the TRS Control can indicate the EHT MCS index.

[0479] Figure 32 shows the UL MU operation of the station according to an embodiment of the present invention and the operation of the station to determine the TB PPDU format.

[0480] In an embodiment of the present invention, a plurality of stations can perform uplink transmission to an AP based on the UL MU operation.

[0481] For example, the AP can transmit a triggering frame to one or more stations (non-AP stations) participating in the UL MU operation. The triggering frame can be used to initiate the UL MU operation. Also, the station that receives the triggering frame can transmit a PPDU to the station (AP) that transmitted the triggering frame as a response to the triggering frame. The UL MU operation can include triggering frame transmission and response transmission to the triggering frame. The PPDU transmitted as a response to the triggering frame can be transmitted after the SIFS from the end of the PPDU including the triggering frame.

[0482] The triggering frame may be a frame that solicits a TB PPDU. Also, the triggering frame may include 1) a trigger frame, or 2) a frame including TRS Control. The response to the triggering frame may be transmitted in the TB PPDU format. For example, an HE TB PPDU, an EHT TB PPDU, or a NEXT TB PPDU may be transmitted as a response to the triggering frame. There may be a method for determining which TB PPDU format to use as a response to the triggering frame. Also, the method for determining which TB PPDU format to use as a response to the triggering frame may vary depending on the type of the triggering frame.

[0483] In the embodiment of FIG. 32, the station can receive a triggering frame. The triggering frame may be a trigger frame or a frame including TRS Control. When the triggering frame is a trigger frame, the station can determine the format of the responding TB PPDU based on the first method. Also, the station can transmit a TB PPDU as a response to the triggering frame using the format of the TB PPDU determined based on the first method. When the triggering frame is a frame including TRS Control, the station can determine the format of the responding TB PPDU based on the second method. Also, the station can transmit a TB PPDU as a response to the triggering frame using the format of the TB PPDU determined based on the second method.

[0484] When the triggering frame is the trigger frame, the station can set the TRIGGER_METHOD, which is a TXVECTOR parameter, to TRIGGER_FRAME. When the triggering frame is a frame including TRS Control, the station can set the TRIGGER_METHOD, which is a TXVECTOR parameter, to TRS. Therefore, in this specification, when the triggering frame is the trigger frame, it may be the same as the case where the TRIGGER_METHOD, which is a TXVECTOR parameter, is TRIGGER_FRAME, and may be the same as the case where the triggering frame is a frame including TRS Control and the TRIGGER_METHOD of TXVECTOR is TRS. When the station transmits an HE TB PPDU, the FORMAT, which is a parameter of TXVECTOR, may be set to HE_TB. When the station receives an HE TB PPDU, the station can set the FORMAT, which is a parameter of RXVECTOR, to HE_TB. When the station transmits an EHT TB PPDU, the station can set the FORMAT of TXVECTOR to EHT_TB. When receiving an EHT TB PPDU, the FORMAT of RXVECTOR may be set to EHT_TB. When the station transmits an HE TB PPDU, it may be the same as the case where the FORMAT of TXVECTOR is HE_TB station, and when the station transmits an EHT TB PPDU, it may be the same as the case where the FORMAT of TXVECTOR is EHT_TB respectively. Also, when the station receives an HE TB PPDU, it may be the same as the case where the FORMAT of RXVECTOR is HE_TB, and when the station receives an EHT TB PPDU, it may be the same as the case where the FORMAT of RXVECTOR is EHT_TB.

[0485] In an embodiment of the present invention, the first method may be a method in which the format of the TB PPDU is determined based on the information indicated by the trigger frame. In still other specific embodiments, the first method may include the embodiments described with reference to FIG. 17. For example, the station can determine the format of the responding TB PPDU based on which variant the User Info field of the trigger frame received by the station is. When the User Info field of the trigger frame received by the station is the HE variant User Info field, the station can respond to the trigger frame with an HE TB PPDU. When the User Info field of the trigger frame received by the station is the EHT variant User Info field, the station can respond to the trigger frame with an EHT TB PPDU. When the User Info field of the trigger frame received by the station is the NEXT variant User Info field, the station can respond to the trigger frame with a NEXT TB PPDU. In the above description, the fact that the station has received the User Info field of the trigger frame can indicate that the station has received the User Info field including the AID12 subfield corresponding to the AID of the station.

[0486] When the value of the 39th bit of the User Info field received by the station and the value of the 54th bit of the Common Info field of the Trigger frame including the User Info field are 0 and 1 respectively, the User Info field may be a HE variant User Info field. In other cases, the User Info field may be an EHT variant User Info field. In other cases, it may include the cases where the value of the 39th bit of the User Info field and the value of the 54th bit of the Common Info field of the trigger frame including the User Info field are 0 and 0, 1 and 0, and 1 and 1 respectively.

[0487] The 39th bit of the User Info field may be a PS160 subfield. The PS160 subfield may be used to indicate the RU or MRU (multiple RU) assigned to the station corresponding to the User Info field. The PS160 subfield can indicate whether the RU or MRU assigned to the station corresponding to the User Info field corresponds to the primary 160 MHz channel or the secondary 160 MHz channel. If the RU or MRU assigned to the station corresponding to the User Info field corresponds to the primary 160 MHz channel, the value of the PS160 subfield may be set to 0. If the RU or MRU assigned to the station corresponding to the User Info field corresponds to the secondary 160 MHz channel, the value of the PS160 subfield may be set to 1. This may apply when the size of the assigned RU or MRU is less than or equal to 2x996 tones.

[0488] The B54 bits of the Common Info field may be the HE / EHT P160 subfield. The HE / EHT P160 subfield can indicate whether the solicited TB PPDU is a HE TB PPDU or an EHT TB PPDU in the primary 160 MHz channel. When the solicited TB PPDU is an EHT TB PPDU in the primary 160 MHz channel, the value of the HE / EHT P160 subfield may be set to 0. When the solicited TB PPDU is a HE TB PPDU in the primary 160 MHz channel, the value of the HE / EHT P160 subfield may be set to 1.

[0489] In an embodiment of the present invention, the second method may be a method for determining the format of a TB PPDU based on a PPDU format including TRS Control. In still other specific embodiments, the second method may include the embodiments described in FIG. 18. For example, based on which PPDU the received TRS Control of the station is included in, the format of the TB PPDU responding to the TRS Control can be determined. For example, when the received TRS Control of the station is included in a HE PPDU, the station can respond to the TRS Control with a HE TB PPDU. When the received TRS Control of the station is included in an EHT PPDU, the station can respond to the TRS Control with an EHT TB PPDU. When the received TRS Control of the station is included in a NEXT PPDU, the station can respond to the TRS Control with a NEXT TB PPDU.

[0490] When the received TRS Control of the station is included in the HE PPDU, when receiving a PPDU including the TRS Control, the FORMAT of the RXVECTOR parameter may be HE_MU, HE_SU, or HE_ER_SU. HE_MU, HE_SU, and HE_ER_SU may be the values of the RXVECTOR parameter or the TXVECTOR parameter corresponding to the HE MU PPDU, HE SU PPDU, and HE ER SU PPDU, respectively. When the received TRS Control of the station is included in the EHT PPDU, when receiving a PPDU including the TRS Control, the FORMAT of the RXVECTOR parameter may be EHT_MU. EHT_MU may be the value of the FORMAT of the RXVECTOR or the TXVECTOR FORMAT corresponding to the EHT MU PPDU. In this specification, the fact that the station has received the TRS Control can indicate that the MAC address of the frame including the TRS Control is set to the MAC address of the station. More specifically, in the present invention, the fact that the station has received the TRS Control can indicate that the RA field of the frame including the TRS Control is set to the MAC address of the station.

[0491] FIG. 33 shows the UL MU operation of the station according to an embodiment of the present invention, and the station sets the L_LENGTH of the TXVECTOR and transmits a PPDU in the UL MU operation.

[0492] The station that has received the triggering frame can transmit the TB PPDU according to the embodiment described in FIG. 32. At this time, the method for the station to set the L-SIG field and the TXVECTOR will be described.

[0493] PPDUs including HE PPDUs and EHT PPDUs may include an L-SIG field and an RL-SIG field. Thus, a TB PPDU may include an L-SIG field and an RL-SIG field. The RL-SIG field has the same fields as the L-SIG field, and the value of the RL-SIG field is set to the same value as the value of the L-SIG field. Examples for the L-SIG field may also apply to the RL-SIG field. The L-SIG field may include a Length field, a Rate field, a Reserved (R) field, a Parity (P) field, and a Signal tail field. The L-SIG field indicates rate information and length information, and a station that receives the L-SIG field can obtain the rate information and the length information from the L-SIG field.

[0494] The value of the Rate field may be set to indicate 6 Mbps. Also, the value of the Reserved field may be set to 0. The Parity field may be set to indicate even parity for 0 to 16 bits. The value of the Signal tail field may be set to 0.

[0495] The value of the Length field may be set according to the format of the PPDU including the Length field. Specifically, the method of setting the Length field when the station transmits an EHT PPDU may be different from the method of setting the Length field when the station transmits an HE PPDU. Specifically, when the station transmits an HE PPDU, the station can set the value of the Length field based on the HE Length formula. More specifically, when the station transmits an HE SU PPDU, an HE ER SU PPDU, or an HE MU PPDU, the station can set the value of the Length field according to the HE Length formula. The HE Length formula may be a formula for setting the Length field included in the HE SU PPDU, the HE ER SU PPDU, and the HE MU PPDU. Also, the HE SU PPDU, the HE ER SU PPDU, and the HE MU PPDU are HE PPDUs that are not TB PPDUs and are not HE PPDUs transmitted in a trigger-based manner.

[0496] (HE Length formula)

[0497] Length = ceil( (TXTIME - SignalExtension - 20) / 4 )*3 - 3 - m

[0498] In the HE Length formula, TXTIME may be the same as the HE TXTIME formula. TXTIME may be in microseconds.

[0499] (HE TXTIME formula)

[0500] TXTIME = 20 + T_HE_PREAMBLE + N_SYM*T_SYM + N_MA*N_HE_LTF*T_HE_LTF_SYM + T_PE + SignalExtension

[0501] T_HE_PREAMBLE may be the length of the preamble of the HE PPDU excluding the L-STF, L-LTF, and L-SIG. That is, T_HE_PREAMBLE may be the sum of the lengths of the RL-SIG, HE-SIG-A, HE-SIG-B (if present, HE-SIG-B is present in the HE MU PPDU. HE-SIG-B is not present in the HE SU PPDU, HE ER SU PPDU, and HE TB PPDU), HE-STF, and HE-LTF.

[0502] N_SYM*T_SYM may be the length of the Data field. N_SYM may be the number of data OFDM symbols. T_SYM may be the length of an OFDM symbol.

[0503] N_MA*N_HE_LTF*T_HE_LTF_SYM may be the total length of the midamble. The midamble may be composed of HE-LTF. N_MA may be the number of midambles. N_HE_LTF may be the number of HE_LTFs. T_HE_LTF_SYM may be the length of the OFDM symbol included in the midamble or HE-LTF.

[0504] T_PE may be the duration of the packet extension field.

[0505] Also, in the HE Length formula, m may be set to 1 for HE MU PPDU and HE ER SU PPDU. Also, m may be set to 2 for other PPDUs, HE SU PPDU and HE TB PPDU. In such an embodiment, the remainder when the value of the Length field is divided by 3 may be determined based on the PPDU format. When the remainder when the value of the Length field is divided by 3 is 2, the station can determine that the Length field is included in the HE MU PPDU or HE ER SU PPDU. When the remainder when the value of the Length field is divided by 3 is 1, the station can determine that the Length field is included in the HE SU PPDU or HE TB PPDU.

[0506] SignalExtension may be the length of the signal extension. When NO_SIG_EXTN, a TXVECTOR parameter, is true, SignalExtension may be 0 us. When NO_SIG_EXTN of TXVECTOR is false, SignalExtension may be aSignalExtension. Also, when the PPDU is transmitted in the 5 GHz or 6 GHz band, aSignalExtension may be 0 us. Also, aSignalExtension may be 6 us when operating in the 2.4 GHz band.

[0507] Also, ceil(A) may be the smallest integer equal to or greater than A.

[0508] The HE Length formula may vary depending on the type of HE PPDU. The value of m described above may be determined based on the type of HE PPDU. Also, the HE Length formula can determine the value of the Length field to be a non-multiple of 3.

[0509] Also, when the station transmits an EHT PPDU, the station can set the value of the Length field according to the EHT Length formula. Specifically, when the station transmits an EHT MU PPDU, the station can set the value of the Length field based on the EHT Length formula. The EHT Length formula may be a formula for setting the Length field included in the EHT MU PPDU. Also, the EHT MU PPDU is an EHT PPDU that is not a TB PPDU and is not transmitted in a trigger-based manner.

[0510] (EHT Length formula)

[0511] Length = ceil( (TXTIME - SignalExtension - 20) / 4 )*3 - 3

[0512] In the EHT Length formula, TXTIME may be the same as the EHT TXTIME formula. TXTIME may be in units of us.

[0513] (EHT TXTIME formula)

[0514] TXTIME = 20 + T_EHT_PREAMBLE + N_SYM*T_SYM + T_PE + SignalExtension

[0515] T_EHT_PREAMBLE may be the preamble length of the EHT PPDU excluding L-STF, L-LTF, and L-SIG. That is, T_EHT_PREAMBLE may be the sum of the lengths of RL-SIG, U-SIG, EHT-SIG (if present, EHT-SIG is present in the EHT MU PPDU. EHT-SIG is not present in the EHT TB PPDU.), EHT-STF, and EHT-LTF.

[0516] N_SYM*T_SYM may be the length of the Data field. N_SYM may be the number of data OFDM symbols. T_SYM may be the length of the OFDM symbol.

[0517] T_PE may be the length of the packet extension field.

[0518] The remainder when the value of the Length field is divided by 3 may be determined by the PPDU format. When the remainder when the value of the Length field is divided by 3 is 0, the station can determine that the PPDU including L-SIG is an EHT PPDU.

[0519] SignalExtension may be the length of the signal extension. When the TXVECTOR parameter NO_SIG_EXTN is true, SignalExtension may be 0 us. When the TXVECTOR parameter NO_SIG_EXTN is false, SignalExtension may be aSignalExtension. Also, when the PPDU is transmitted in the 5 GHz or 6 GHz band, aSignalExtension may be 0 us. Also, when the PPDU is transmitted in the 2.4 GHz band, aSignalExtension may be 6 us.

[0520] Also, ceil(A) may be the smallest integer equal to or greater than A.

[0521] The EHT Length formula may be a fixed formula that does not vary depending on the type of EHT PPDU. The EHT Length formula can determine the value of the Length field as a multiple of 3.

[0522] When a station transmits a NEXT PPDU, the station can set the value of the Length field based on the NEXT Length formula. The NEXT Length formula can set a multiple of 3 as the value of the Length field, similar to the EHT Length formula. The NEXT Length formula may be a formula obtained by replacing the parts corresponding to EHT with the parts corresponding to NEXT in the part where the EHT Length formula was described.

[0523] When a station transmits a TB PPDU, the station can set the value of the Length field with a value obtained based on the value of L_LENGTH, which is a TXVECTOR parameter. For example, when a station transmits a HE TB PPDU, the station can set the value of the Length field to the same value as L_LENGTH of the TXVECTOR. Also, when a station transmits an EHT TB PPDU, the station can set the value of the Length field to the value obtained by adding 2 to L_LENGTH of the TXVECTOR.

[0524] When a station transmits a TB PPDU as a response to a trigger frame, the station can set the value of L_LENGTH of the TXVECTOR to the value of the UL Length subfield of the Common Info field included in the trigger frame. When a station transmits a HE TB PPDU as a response to a trigger frame, or when a station transmits an EHT TB PPDU as a response to a trigger frame, the station can set L_LENGTH of the TXVECTOR to the value of the UL Length subfield of the Common Info field included in the trigger frame.

[0525] Also, the station can set the UL Length field of the trigger frame that induces the TB PPDU to a value where m is 2 in the HE Length formula. For example, the value of the UL Length field of the trigger frame that induces the HE TB PPDU can be set to a value where m is 2 in the HE Length formula. Or, the station can set the value of the UL Length field of the trigger frame that induces the TB PPDU to a value obtained by subtracting 2 from the EHT Length formula. For example, the station can set the value of the UL Length field of the trigger frame that induces the EHT TB PPDU to a value obtained by subtracting 2 from the EHT Length formula.

[0526] The station can set the value of the UL Length field of the trigger frame and the value of L_LENGTH of the TXVECTOR used when responding to the trigger frame to a value that is not a multiple of 3. Also, the station can set the value of the UL Length field included in the trigger frame and the value of L_LENGTH of the TXVECTOR used when responding to the trigger frame to a value where the remainder when divided by 3 is 1.

[0527] Also, when the station transmits the HE TB PPDU according to the foregoing embodiment and sets the value of the Length field to the same value as L_LENGTH of the TXVECTOR, the value of the Length field included in the HE TB PPDU induced by the trigger frame may be set to a value that is not a multiple of 3. Specifically, the value of the Length field may be a value where the remainder when divided by 3 is 1.

[0528] Also, when the station transmits an EHT TB PPDU according to the foregoing embodiments, the value of the Length field can be set to the value obtained by adding 2 to L_LENGTH of the TXVECTOR. At this time, the value of the Length field included in the EHT TB PPDU induced by the trigger frame may be set to a value that is a multiple of 3. Thereby, the station that transmits the trigger frame sets the value of the UL Length field in the same way whether it induces the transmission of an HE TB PPDU or an EHT TB PPDU, and based on the trigger frame, the station that transmits the EHT TB PPDU can set the value of the Length field of the L-SIG to a multiple of 3.

[0529] When the station transmits a TB PPDU as a response to the TRS Control, the station can set the value of L_LENGTH of the TXVECTOR to the value calculated by the Length formula specified in advance for each TB PPDU standard that the station transmits, that is, the TB PPDU. At this time, the Length formula is calculated by the TXTIME formula corresponding to each standard, and the N_SYM value included in the TXTIME formula may be set to FVAL + 1. FVAL may be the value of the UL Data Symbols subfield included in the TRS Control.

[0530] When the station transmits an HE TB PPDU as a response to the TRS Control, the station can set the L_LENGTH of the TXVECTOR to the value calculated by the HE Length formula corresponding to the PPDU to be transmitted. At this time, when calculating by the HE Length formula transmitted by the station, the station can set the N_SYM value included in the HE TXTIME formula to FVAL + 1. FVAL may be the value of the UL Data Symbols subfield included in the TRS Control.

[0531] When transmitting a HE TB PPDU in response to TRS Control, if the TXVECTOR L_LENGTH is calculated by the HE Length formula, the L_LENGTH of the TXVECTOR may be a value that is not a multiple of 3 or a value with a remainder of 1 when divided by 3. Also, when a station transmits a HE TB PPDU according to the foregoing embodiment, the station can set the value of the Length field to the same value as the L_LENGTH of the TXVECTOR. At this time, the value of the Length field included in the HE TB PPDU induced by the TRS Control may be set to a value that is not a multiple of 3. Specifically, the value of the Length field may be a value with a remainder of 1 when divided by 3.

[0532] Also, when a station transmits an EHT TB PPDU as a response to TRS Control, the station can set the value of the L_LENGTH of the TXVECTOR to the value calculated by the EHT Length formula corresponding to the PPDU transmitted by the station. At this time, when the station calculates the value of the L_LENGTH by the EHT Length formula, the N_SYM value included in the EHT TXTIME formula may be set to FVAL + 1. FVAL may be the value of the UL Data Symbols subfield included in the TRS Control.

[0533] When a station transmits an EHT TB PPDU in response to TRS Control, the station can calculate the L_LENGTH of the TXVECTOR using the EHT Length formula. At this time, the L_LENGTH of the TXVECTOR is set to a value that is a multiple of 3, that is, a value with a remainder of 0 when divided by 3. Also, when the station transmits an EHT TB PPDU according to the above-described embodiment, the station can set the value of the Length field of the EHT TB PPDU to a value obtained by adding 2 to the value of the L_LENGTH of the TXVECTOR. At this time, the value of the Length field included in the EHT TB PPDU induced by TRS Control is set to a value that is not a multiple of 3. Specifically, the value of the Length field has a remainder of 1 when divided by 3.

[0534] As in the foregoing embodiments, when the station determines which format of HE PPDU and EHT PPDU it corresponds to based on the remainder value when the value of the Length field is divided by 3, and determines that it is an EHT PPDU when the remainder value is 0, the station can determine the EHT TB PPDU as an HE PPDU. Specifically, when the received PPDU of the station does not include the RL-SIG field, the station can determine that the received PPDU is any one of a non-HT PPDU, an HT PPDU, and a VHT PPDU. Also, when the received PPDU of the station includes the RL-SIG field, the station can determine that the received PPDU is an HE PPDU or an EHT PPDU. Further, in another specific embodiment, when the received PPDU of the station includes the RL-SIG field, the station can determine that the received PPDU is an HE PPDU, an EHT TB PPDU, or a NEXT PPDU. In such an embodiment, if the remainder value when the value of the L-Length field of the PPDU including RL-SIG is divided by 3 is not 0, the station can determine that the received PPDU is an HE PPDU. Also, if the remainder value when the value of the L-Length field of the PPDU including RL-SIG is divided by 3 is 0, the station can determine that the received PPDU is an EHT PPDU or a NEXT PPDU. At this time, the station can distinguish between an EHT TB PPDU and a NEXT PPDU based on the value of the PHY Version Identifier subfield of the U-SIG field. FIG. 33 shows the operation of the station to which such an embodiment is applied.

[0535] In FIG. 33, the first station (STA1) receives a triggering frame and transmits a TB PPDU as a response to the triggering frame. When the triggering frame is a trigger frame, the first station (STA1) sets the value of L_LENGTH of the TXVECTOR to the value of the UL Length subfield included in the trigger frame. When the triggering frame includes a TRS Control, the first station (STA1) sets the value obtained by the HE Length formula or the EHT Length formula as the value of L_LENGTH of the TXVECTOR. The PHY of the first station (STA1) can set the value of the Length field of the L-SIG field based on the value of L_LENGTH of the TXVECTOR. When the first station (STA1) transmits an HE TB PPDU as a response to the triggering frame, the first station (STA1) sets the value of the Length field to the value of L_LENGTH of the TXVECTOR. When the first station (STA1) transmits an EHT TB PPDU as a response to the triggering frame, the first station (STA1) sets the value of the Length field to the value obtained by adding 2 to the value of L_LENGTH of the TXVECTOR.

[0536] In connection with the problem described in FIG. 33, the station can determine how to set the value of the Length subfield of the L-SIG field of the EHT TB PPDU based on the triggering frame that induced the EHT TB PPDU. This will be specifically described in FIG. 34.

[0537] FIG. 34 shows the UL MU operation of a station and the station setting the L_LENGTH of the TXVECTOR and transmitting a PPDU in the UL MU operation according to still another embodiment of the present invention.

[0538] In an embodiment of the present invention, based on the type of the triggering frame that induces the TB PPDU and the format of the TB PPDU, the station can set the value of L_LENGTH of the TXVECTOR parameter used when transmitting the TB PPDU and the value of the Length subfield of the L-SIG field of the TB PPDU. Specifically, the station can determine how to set the value of L_LENGTH of the TXVECTOR parameter when transmitting the EHT TB PPDU based on which triggering frame the EHT TB PPDU is induced by. In a specific embodiment, when the transmission of the EHT TB PPDU is induced by a trigger frame, the station can set the value of the Length subfield of the L-SIG field of the EHT TB PPDU to the value obtained by adding 2 to the value of L_LENGTH of the TXVECTOR parameter used when transmitting the EHT TB PPDU. Also, when the transmission of the EHT TB PPDU is induced by a frame including TRS Control, the station can set the value of the Length subfield of the L-SIG field of the EHT TB PPDU to the value of L_LENGTH of the TXVECTOR parameter used when transmitting the EHT TB PPDU. When applying such an embodiment, the station can use the formula for setting the value of L_LENGTH of the TXVECTOPR parameter of the EHT PPDU that is not the EHT TB PPDU to set the value of L_LENGTH of the TXVECTOPR parameter of the EHT TB PPDU. The formula for setting the value of L_LENGTH of the TXVECTOPR parameter of the EHT PPDU that is not the EHT TB PPDU is the aforementioned EHT Length formula. That is, with such an embodiment, the station can set the value of the Length field of the L-SIG of the EHT PPDU to a multiple of 3, and can reduce the complexity of the method for setting the value of L_LENGTH of the TXVECTOPR parameter of the EHT PPDU.

[0539] When the station transmits an HE TB PPDU, the station can set the value of L_LENGTH of the TXVECTOR parameter used to transmit the value of the HE TB PPDU as the value of the Length field of the L-SIG of the HE TB PPDU. At this time, the L_LENGTH value of the TXVECTOPR parameter of the HE PPDU may be set by the HE Length formula described above.

[0540] In FIG. 34, the first station (STA1) receives a triggering frame and transmits a TB PPDU as a response to the triggering frame. When the triggering frame is a trigger frame, the first station (STA1) sets the value of L_LENGTH of the TXVETOR to the value of the UL Length subfield included in the trigger frame. When the triggering frame includes a TRS Control, the first station (STA1) sets the value obtained by the HE Length formula or the EHT Length formula as the value of L_LENGTH of the TXVECTOR. The PHY of the first station (STA1) can set the value of the Length field of the L-SIG field based on the value of L_LENGTH of the TXVECTOR. When the first station (STA1) transmits an HE TB PPDU as a response to the triggering frame, the first station (STA1) sets the value of the Length field to the value of L_LENGTH of the TXVECTOR. When the first station (STA1) transmits an EHT TB PPDU as a response to the triggering frame and the trigger frame induces the transmission of the EHT TB PPDU, the first station (STA1) sets the value of the Length field to the value obtained by adding 2 to the value of L_LENGTH of the TXVECTOR. Also, when the first station (STA1) transmits an EHT TB PPDU as a response to the triggering frame and a frame including a TRS Control induces the transmission of the EHT TB PPDU, the first station (STA1) sets the value of the Length field to the value of L_LENGTH of the TXVECTOR.

[0541] According to the embodiment described with reference to FIG. 34, the operation of the PHY that receives the PPDU can become complicated. Further, in other specific embodiments, the station can determine how to set the value of L_LENGTH of the TXVECTOR used when transmitting the EHT TB PPDU based on what triggering frame induced the EHT TB PPDU. This will be specifically described with reference to FIG. 35.

[0542] FIG. 35 shows the UL MU operation of the station and the station setting the L_LENGTH of the TXVECTOR to transmit the PPDU in the UL MU operation according to still other embodiments of the present invention.

[0543] When a station transmits a TB PPDU, the station can set the value of L_LENGTH of TXVECTOR based on the format of the TB PPDU and the type of the triggering frame that induced the transmission of the TB PPDU. Specifically, when the triggering frame is a trigger frame, the station can set the value of L_LENGTH of TXVECTOR to the value of the UL Length subfield of the trigger frame. When the triggering frame contains TRS Control, when the station transmits an EHT TB PPDU as a response to the triggering frame, the station can set the value of L_LENGTH of TXVECTOR to the value obtained by subtracting 2 from the value obtained by the formula used for setting the L_LENGTH value of the TXVECTOR of an EHT PPDU other than the EHT TB PPDU. At this time, the formula used for setting the L_LENGTH value of the TXVECTOR of an EHT PPDU other than the EHT TB PPDU may be the EHT Length formula described above. When the triggering frame contains TRS Control and the station transmits a HE TB PPDU as a response to the triggering frame, the station can set the value of L_LENGTH of TXVECTOR to the value obtained by the formula used for setting the L_LENGTH value of the TXVECTOR of the HE PPDU. At this time, the formula used for setting the L_LENGTH value of the TXVECTOR of the HE PPDU may be the HE Length formula described above.

[0544] Also, when the station transmits a PPDU other than an EHT TB PPDU, the station can set the value of L_LENGTH in TXVETOR as the value of the Length field in L-SIG. When the station transmits an EHT TB PPDU, the station can set the value obtained by adding 2 to the value of L_LENGTH in TXVETOR as the value of the Length field in L-SIG. According to such an embodiment, the value of the Length field in L-SIG of the EHT TB PPDU is set to a multiple of 3, and the value of the Length field in L-SIG of the HE TB PPDU can be set to a value that is not a multiple of 3. Therefore, a station receiving an EHT TB PPDU can determine the format of the EHT TB PPDU based on the value of the Length field in L-SIG. Also, according to such an embodiment, a station transmitting an EHT TB PPDU can set the value of the L-SIG field using the L_LENGTH value in TXVETOR regardless of the type of the triggering frame that induced the transmission of the EHT TB PPDU.

[0545] In FIG. 35, the first station (STA1) receives a triggering frame and transmits a TB PPDU as a response to the triggering frame. When the triggering frame is a trigger frame, the first station (STA1) sets the value of L_LENGTH of the TXVECTOR to the value of the UL Length subfield included in the trigger frame. When the triggering frame includes TRS Control and the station transmits an HE TB PPDU as a response to the triggering frame, the first station (STA1) sets the value obtained by the HE Length formula as the value of L_LENGTH of the TXVECTOR. When the triggering frame includes TRS Control and the station transmits an EHT TB PPDU as a response to the triggering frame, the first station (STA1) sets the value obtained by subtracting 2 from the value obtained by the EHT Length formula as the value of L_LENGTH of the TXVECTOR. The PHY of the first station (STA1) can set the value of the Length field of the L-SIG field based on the value of L_LENGTH of the TXVECTOR. When the first station (STA1) transmits an HE TB PPDU as a response to the triggering frame, the first station (STA1) sets the value of the Length field to the value of L_LENGTH of the TXVECTOR. When the first station (STA1) transmits an EHT TB PPDU as a response to the triggering frame, the first station (STA1) sets the value of the Length field to the value obtained by adding 2 to the value of L_LENGTH of the TXVECTOR.

[0546] The same may be equally applicable when a station that raises the examples described in FIGS. 34 to 35 transmits a NEXT TB PPDU. Specifically, it may be applicable to the operation of setting the value of L_LENGTH of the TXVECTOR used for transmitting the EHT TB PPDU and the operation of setting the value of the Length field of the L-SIG of the EHT TB PPDU in the examples described in FIGS. 34 to 35.

[0547] Also, in FIGS. 30 to 35, for the operations of adding 2 or subtracting 2 in the embodiments, a value specified in advance may be used instead of 2.

[0548] FIG. 36 shows that the station according to the embodiment of the present invention receives a PPDU and sets the FORMAT of the RXVECTOR.

[0549] As described above, when the received PPDU of the station does not include the RL-SIG field, the station can determine that the received PPDU is any one of a non-HT PPDU, an HT PPDU, and a VHT PPDU. Also, when the received PPDU of the station includes the RL-SIG field, the station can determine that the received PPDU is a HE PPDU or an EHT PPDU. Further, in other specific embodiments, when the received PPDU of the station includes the RL-SIG field, the station can determine that the received PPDU is a HE PPDU, an EHT TB PPDU, or a NEXT PPDU. In such an embodiment, if the remainder value obtained by dividing the value of the L-Length field of the PPDU including RL-SIG by 3 is not 0, the station can determine that the received PPDU is a HE PPDU. Also, if the remainder value obtained by dividing the value of the L-Length field of the PPDU including RL-SIG by 3 is 0, the station can determine that the received PPDU is an EHT PPDU or a NEXT PPDU. Also, if the remainder value obtained by dividing the value of the L-Length field of the PPDU including RL-SIG by 3 is 0, the station can determine that the received PPDU includes the U-SIG field. The station can distinguish between an EHT TB PPDU and a NEXT PPDU based on the value of the PHY Version Identifier subfield of the U-SIG field. FIG. 33 shows the operation of the station to which such an embodiment is applied.

[0550] Further, the U-SIG field may include at least any one of a PHY Version Identifier field, a Bandwidth field, a UL / DL field, a BSS Color field, a TXOP field, a PPDU Type And Compression Mode field, a Punctured Channel Information field, an MCS field, and a Number Of SIG Symbols field. Also, the U-SIG field may include a version independent field and a version dependent field. The version independent field may be a field that is identically included in the U-SIG field regardless of the PHY Version Identifier field indicated by the U-SIG field. The version dependent field may be a field that is set in the U-SIG field based on the PHY Version Identifier field indicated by the U-SIG field. The version independent field may include a PHY Version Identifier field, a Bandwidth field, a UL / DL field, a BSS Color field, and a TXOP field.

[0551] The station can defer during the duration of the PPDU based on the Version Independent field of the received U-SIG field. At this time, the duration of the PPDU may be the TXOP duration indicated by the U-SIG field. Specifically, the station can set the NAV based on at least any one of the BSS color field and the TXOP field of the Version Independent field. Specifically, the station can set the basic NAV or the Intra-BSS NAV based on at least any one of the BSS color field and the TXOP field of the Version Independent field.

[0552] The station can operate based on the Version Independent field even when receiving a PPDU not supported by the station, such as a PPDU defined by a standard not supported by the station. Specifically, the station can obtain the Version Independent field from a PPDU not supported by the station. At this time, the station can perform a defer operation based on the obtained Version Independent field. Specifically, the station can set the NAV based on the obtained Version Independent field. Since such an operation is performed by the MAC, in order to perform such an operation, the station needs to transmit the information obtained from the signaling field of the physical layer to the MAC layer. For this purpose, a method for indicating the format of the non-supported PPDU will be described.

[0553] Examples regarding the position of the aforementioned Version Independent field will be described. The U-SIG field may include two OFDM symbols. Of the two OFDM symbols, the U-SIG field included in the first OFDM symbol can be referred to as the U-SIG1 field, and the U-SIG field included in the second OFDM symbol can be referred to as the U-SIG2 field. The U-SIG1 field may include the Version Independent field. In still other specific embodiments, the U-SIG2 field may include the Version Independent field.

[0554] Previously, each of the PPDU formats was indicated by one of the variables. However, in order to support PPDU formats to be introduced in the future and utilize the value of the Version Independent field of the PPDU, a method for effectively indicating it is necessary. The PHY of the station that receives the PPDU can transmit to the MAC by specifying the version of the PPDU that the station does not know (unknown) as a pre-specified value. Specifically, the PHY of the station that receives the PPDU can set the FORMAT of the REXVECTOR to a pre-specified value. Specifically, when the value of the PHY Version Identifier field of the PPDU is 0, an EHT or EHT PPDU can be indicated. Also, when the value of the PHY Version Identifier field of the PPDU is 1 to 7, a NEXT or NEXT PPDU can be indicated. Also, when the value of the PHY Version Identifier field of the PPDU is 1 to 7, the station can determine that the PHY Version Identifier field is valid. Even if the value of the PHY Version Identifier field indicates a PPDU in a format not supported by the station, the station can defer during the duration of the PPDU. Also, even if the value of the PHY Version Identifier field indicates a PPDU in a format not supported by the station, the PHY of the station can transmit the information indicated by the Version Independent field to the MAC. For this purpose, the station can set the CH_BANDWIDTH, UPLINK_FLAG, BSS_COLOR, and TXOP_DURATION of the RXVECTOR based on the information indicated by the Version Independent field. At this time, the station does not have to set the parameters of the RXVECTOR that cannot be set by the information indicated by the Version Independent field, for example, parameters other than FORMAT, CH_BANDWIDTH, UPLINK_FLAG, BSS_COLOR, and TXOP_DURATION.

[0555] As described above, the PHY of the station can transmit the format of an unknown PPDU to the MAC by setting the FORMAT of the RXVETOR to a pre-specified value. The pre-specified value may be UNK. Also, when the value of the PHY Version Identifier field indicates a PPDU in a format not supported by the station, the value of the PHY Version Identifier field may be any one of 1 to 7. The value UNK of the FORMAT of the RXVECTOR is a value that is distinguished from NON_HT, HT_MF, HT_GF, VHT, HE_SU, HE_MU, HE_ER_SU, HE_TB, EHT_MU, and EHT_TB. NON_HT indicates a non-HT PPDU or a non-HT duplicate PPDU. Also, HT_MF indicates an HT-mixed PPDU. Also, HT_GF indicates an HT-greenfield PPDU. Also, VHT indicates a VHT PPDU. Also, HE_SU indicates an HE SU PPDU. Also, HE_MU indicates an HE MU PPDU. Also, HE_ER_SU indicates an HE ER SU PPDU. Also, HE_TB indicates an HE TB PPDU. Also, EHT_MU indicates an EHT MU PPDU. Also, EHT_TB indicates an EHT TB PPDU. Also, the pre-specified value may not be used as the FORMAT of the TXVECTOR. This is because the station transmitting the PPDU already supports the format of the PPDU to be transmitted.

[0556] In the embodiment of FIG. 36, the first station (STA1) receives a NEXT PPDU that is not supported by the first station (STA1). At this time, the first station (STA1) obtains the U-SIG field from the PPDU. Since the value of the PHY Verision Idenfier field in the U-SIG field indicates a PPDU that is not supported by the first station (STA1), the PHY of the first station (STA1) sets the value of FORMAT in the RXVECTOR to UNK and transmits the information obtained from the Version Independent field of the U-SIG field to the MAC. At this time, the PHY of the first station (STA1) sets the RXVECTOR based on the information obtained from the Version Independent field of the U-SIG field.

[0557] In the embodiment described above, the pre-specified value may be the latest PPDU format indicated by the station instead of UNK. For example, an EHT station can use EHT_MU or EHT TB as the pre-specified value.

[0558] The present invention has been described above by taking wireless LAN communication as an example. However, the present invention is not limited to this, and may be equally applied to other communication systems such as cellular communication. Also, although the method, apparatus, and system of the present invention have been described in relation to specific embodiments, some or all of the components and operations of the present invention can be implemented using a computer system having a general-purpose hardware architecture.

[0559] The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified for other embodiments by those with ordinary knowledge in the field to which the embodiments belong. Therefore, the content related to such combinations and modifications should be construed as being included in the scope of the present invention.

[0560] Although the above description has focused on the embodiments, these are merely examples and do not limit the present invention. Those with ordinary knowledge in the field to which the present invention pertains will understand that various modifications and applications not exemplified above are possible without departing from the essential characteristics of these embodiments. For example, each component specifically shown in the embodiments can be implemented with modifications. And the differences related to such modifications and applications should be construed as being included within the scope of the present invention defined by the appended claims.

Claims

1. A station that communicates wirelessly, including a transceiver and, a processor, wherein the processor receives a triggering frame that triggers the transmission of the station via the transceiver, determines a value of a Length field in a signaling field of the TB PPDU (physical layer protocol data unit) based on a type of the triggering frame and a type of a trigger-based (TB) PPDU transmitted as a response to the triggering frame, the Length field indicating a value used to calculate a duration of the TB PPDU, and transmits the TB PPDU.

2. The processor sets a value of L_Length of TXVECTOR as a value of a UL Length field of the triggering frame when the triggering frame is a trigger frame, and sets a value obtained based on the value of L_Length according to a format of the TB PPDU as a value of the Length field, and sets the value of L_Length according to a format of the TB PPDU and a formula specified in advance for each format of the TB PPDU when the triggering frame is a frame including a TRS Control field, and sets a value obtained by adding 2 to the value of L_Length as a value of the Length field. The station according to claim 1.

3. When the triggering frame is a frame including a TRS Control field and the format of the TB PPDU is a HE TB PPDU, the value of L_Length is set to a value obtained by a formula specified in advance for the HE TB PPDU, When the triggering frame is a frame including a TRS Control field and the format of the TB PPDU is an EHT TB PPDU, the value of L_Length is set to a value obtained by subtracting 2 from a value obtained by a formula specified in advance for the EHT TB PPDU. The station according to claim 2.

4. The remainder value when the value of the Length field is divided by 3 is used when distinguishing between the HE TB PPDU and the EHT TB PPDU. The station according to claim 3.

5. The formula specified in advance for the EHT TB PPDU is the following formula: Length = ceil( (TXTIME - SignalExtension - 20) / 4 )*3 - 3 ceil(x) represents the ceiling value of x. SignalExtension represents the length of the signal extension. TXTIME is obtained by the following formula: TXTIME = 20 + T_EHT_PREAMBLE + N_SYM*T_SYM + T_PE + SignalExtension T_EHT_PREAMBLE is the length of the preamble of the EHT TB PPDU excluding L-STF, L-LTF, and L-SIG. N_SYM*T_SYM is the length of the data field of the EHT TB PPDU. N_SYM is the number of data OFDM symbols. T_SYM is the length of one OFDM symbol. T_PE is the length of the packet extension field. The station according to claim 3.

6. The processor When receiving a PPDU (physical layer protocol data unit) via the transceiver, if the PPDU meets the specified conditions, the value of the PHY Version Identifier field indicating the format of the received PPDU is obtained from the signaling field of the received PPDU. When the value of the obtained PHY Version Identifier field indicates a PPDU format not supported by the station, the value of FORMAT of the RX VECTOR transmitted to the MAC (medium access control) layer of the station is set to a specified value. The station according to claim 1.

7. The processor The station according to claim 6, wherein when the value of the obtained PHY Version Identifier field indicates the format of the PPDU supported by the station, the value of the FORMAT of the RX VECTOR is set to a value corresponding to the format of the PPDU indicated by the value of the obtained PHY Version Identifier field.

8. The received PPDU includes a Version Independent field regardless of the value of the PHY Version Identifier field, The processor, The station according to claim 6, wherein when the value of the obtained PHY Version Identifier field indicates the format of the PPDU not supported by the station, the information obtained from the Version Independent field is transmitted to the MAC layer of the station.

9. The processor, sets the CH_BANDWIDTH, UPLINK_FLAG, BSS_COLOR, and TXOP_DURATION of the RX VECTOR based on the information obtained from the Version Independent field, The CH_BANDWIDTH indicates the bandwidth of the received PPDU, The UPLINK_FLAG indicates whether the received PPDU is an uplink PPDU, The BSS_COLOR indicates the BSS color to which the received PPDU belongs, The station according to claim 8, wherein the TXOP_DURATION indicates the duration of the TXOP in which the received PPDU is exchanged.

10. A method for operating a station that communicates wirelessly, comprising: receiving a triggering frame that triggers transmission of the station; determining a value of a Length field of a signaling field of the TB PPDU based on a type of the triggering frame and a type of a trigger-based (TB) PPDU (physical layer protocol data unit) transmitted as a response to the triggering frame, the Length field indicating a value used to calculate a duration of the TB PPDU. A method of operation, including the step of transmitting the TB PPDU. **Claim 11** The step of determining the value of the Length field in the signaling field of the TB PPDU is as follows: When the triggering frame is a trigger frame, set the value of L_Length of the TXVECTOR as the value of the UL Length field of the trigger frame, and set the value obtained based on the value of L_Length according to the format of the TB PPDU as the value of the Length field; When the triggering frame is a frame including a TRS Control field, set the value of L_Length based on the format of the TB PPDU and a predefined mathematical formula for each format of the TB PPDU, and set the value obtained by adding 2 to the value of L_Length as the value of the Length field. The method of operation according to claim 10 includes these steps. **Claim 12** When the triggering frame is a frame including a TRS Control field, the step of setting the value of the Length field is as follows: When the triggering frame is a frame including a TRS Control field and the format of the TB PPDU is a HE TB PPDU, set the value of L_Length to the value obtained by a predefined mathematical formula for the HE TB PPDU; When the triggering frame is a frame including a TRS Control field and the format of the TB PPDU is an EHT TB PPDU, set the value of L_Length to the value obtained by subtracting 2 from the value obtained by a predefined mathematical formula for the EHT TB PPDU. The method of operation according to claim 11 includes these steps. **Claim 13** The remainder value when the value of the Length field is divided by 3 is used when distinguishing between the HE TB PPDU and the EHT TB PPDU. The method of operation according to claim 12. **Claim 14** The predefined mathematical formula for the EHT TB PPDU is the following formula: Length = ceil( (TXTIME - SignalExtension - 20) / 4 )*3 - 3 ceil(x) represents the ceiling value of x. SignalExtension represents the length of the signal extension, TX TIME is obtained by the following formula, TXTIME = 20 + T_EHT_PREAMBLE + N_SYM*T_SYM + T_PE + SignalExtension T_EHT_PREAMBLE is the length of the preamble of the EHT TB PPDU excluding L-STF, L-LTF, and L-SIG, N_SYM*T_SYM is the length of the data field of the EHT TB PPDU, N_SYM is the number of data OFDM symbols, T_SYM is the length of one OFDM symbol, T_PE is the length of the packet extension field, the operation method according to claim 12.

15. The operation method is as follows, When receiving a PPDU (physical layer protocol data unit) via a transceiver, if the PPDU meets a predefined condition, obtaining the value of the PHY Version Identifier field that indicates the format of the received PPDU from the signaling field of the received PPDU; When the value of the obtained PHY Version Identifier field indicates a PPDU format not supported by the station, setting the value of FORMAT of RX VECTOR transmitted to the MAC (medium access control) layer of the station to a predefined value. The operation method according to claim 10 further includes this step.

16. The operation method is as follows, When the value of the obtained PHY Version Identifier field indicates a PPDU format supported by the station, further including the step of setting the value of FORMAT of RX VECTOR to a value corresponding to the PPDU format indicated by the value of the obtained PHY Version Identifier field. The operation method according to claim 15 includes this step.

17. The received PPDU includes a Version Independent field regardless of the value of the PHY Version Identifier field, The operation method is as follows, The method of operation according to claim 15, further comprising the step of transmitting the information obtained from the Version Independent field to the MAC layer of the station when the value of the obtained PHY Version Identifier field indicates a format of a PPDU not supported by the station. **Claim 18** The step of transmitting the information obtained from the Version Independent field to the MAC layer of the station comprises: setting CH_BANDWIDTH, UPLINK_FLAG, BSS_COLOR, and TXOP_DURATION of the RX VECTOR based on the information obtained from the Version Independent field, wherein the CH_BANDWIDTH indicates the bandwidth of the received PPDU, the UPLINK_FLAG indicates whether the received PPDU is an uplink PPDU, the BSS_COLOR indicates the BSS color to which the received PPDU belongs, and the TXOP_DURATION indicates the duration of the TXOP in which the received PPDU was exchanged, the method of operation according to claim 17.

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