Methods for sending and receiving data in wireless communication systems and wireless communication terminals

Abstract

To provide a method for transmitting / receiving a TB PPDU based on a trigger frame in a radio communications system.SOLUTION: A terminal receives a trigger frame from an AP (Access Point) and transmits a response frame as a response thereto. The response frame may be generated on the basis of a format of the response frame and / or information acquired from a first plurality of spatial reuse fields or a second plurality of spatial reuse fields of the trigger frame by a resource unit.SELECTED DRAWING: Figure 33

Description

Technical Field

[0002] , , ,

[0003]

[0001] The present invention relates to a wireless communication system. More specifically, the present invention relates to a trigger frame for instructing the transmission of a TB (Trigger Based) PPDU (Physical layer Protocol Data Unit) in a wireless communication system, and a method and apparatus for configuring and transmitting and receiving a TB PPDU based on the trigger frame.

Background Art

[0002] Recently, as the popularity of mobile devices has spread, wireless LAN technology that can provide fast wireless Internet services to them has been in the spotlight. Wireless LAN technology is a technology that enables mobile devices such as smartphones, smart pads, laptop PCs, portable multimedia players, and embedded devices to be wirelessly connected to the Internet in homes, enterprises, or specific service-providing areas based on wireless communication technology at short distances.

[0003] Since supporting early wireless LAN technologies using the 2.4GHz frequency band, IEEE (Institute of Electronics Engineers) 802.11 has commercialized or is developing standards for a variety of technologies. First, IEEE 802.11b uses the 2.4GHz band frequency and supports communication speeds up to 11Mbps. IEEE 802.11a, which was commercialized after IEEE 802.11b, uses the 5GHz band frequency band instead of the 2.4GHz band, reducing interference compared to the considerably congested 2.4GHz band frequency band, and uses OFDM technology to increase communication speeds up to 54Mbps. However, IEEE 802.11a has the disadvantage of a shorter communication range compared to IEEE 802.11b. Furthermore, IEEE 802.11g, like IEEE 802.11b, uses the 2.4GHz band to achieve a maximum communication speed of 54Mbps and satisfies backward compatibility, attracting considerable attention, but it also has an advantage over IEEE 802.11a in terms of communication range.

[0004] Furthermore, IEEE 802.11n is a technical standard established to overcome the limitations in communication speed that had been pointed out as a vulnerability in wireless LANs. The purpose of IEEE 802.11n is to increase network speed and reliability and extend the operating range of wireless networks. Specifically, IEEE 802.11n supports high throughput (HT) with a data processing speed of up to 540 Mbps or more, and is based on MIMO (Multiple Inputs and Multiple Outputs) technology, which uses multiple antennas at both the transmitter and receiver ends to minimize transmission errors and optimize data speed. In addition, this standard uses a coding method that transmits multiple duplicate copies to improve data reliability.

[0005] As the proliferation of wireless LANs accelerates and the applications using them diversify, there is a growing need for new wireless LAN systems that can support very high throughput (VHT) higher than the data processing speed supported by IEEE 802.11n. Among these, IEEE 802.11ac supports a wide bandwidth (80MHz to 160MHz) at the 5GHz frequency. Although the IEEE 802.11ac standard is defined only in the 5GHz band, early 11ac chipsets are expected to support operation in the 2.4GHz band for backward compatibility with older 2.4GHz band products. Theoretically, this standard allows for a minimum wireless LAN speed of 1Gbps and a maximum single-link speed of 500Mbps. This is achieved by extending the wireless interface concepts accepted in 802.11n, including wider radio frequency bandwidth (up to 160MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high-density modulation (up to 256QAM). Another method for transmitting data using the 60GHz band instead of the conventional 24GHz / 5GHz band is IEEE 802.11ad. IEEE 802.11ad is a transmission standard that uses beamforming technology to provide speeds of up to 7Gbps, making it suitable for streaming large amounts of data and high-bitrate video such as uncompressed HD video. However, the 60GHz frequency band has the disadvantage of being difficult to pass through obstacles, limiting its use to devices in short-range spaces.

[0006] Meanwhile, the IEEE 802.11ax (High Efficiency WLAN, HEW) standard has been developed and is nearing completion as a wireless LAN standard for 802.11ac and 802.11ad and beyond, to provide highly efficient and high-performance wireless LAN communication technology in high-density environments where access points (APs) and terminals are densely packed. In an 802.11ax-based wireless LAN environment, it is necessary to provide highly frequency-efficient communication indoors and outdoors in the presence of high-density stations and APs (Access Points), and various technologies have been developed to realize this.

[0007] Furthermore, in order to support new multimedia applications such as high-definition video and real-time games, development has begun on a new wireless LAN standard to increase the maximum transmission speed. The 7th generation wireless LAN standard, IEEE 802.11be (Extremely High Throughput, EHT), is being developed with the goal of supporting a maximum transmission rate of 30 Gbps in the 2.4 / 5 / 6 GHz band through wider bandwidth, increased spatial streams, and multiple AP coordination. [Overview of the project] [Problems that the invention aims to solve]

[0008] As mentioned above, the purpose of this invention is to provide an ultra-high-speed wireless LAN service for new multimedia applications.

[0009] Furthermore, the present invention aims to provide a method and apparatus for configuring a trigger frame according to type for instructing the transmission of a TB PPDU, which is a PPDU based on a trigger frame.

[0010] Furthermore, the present invention aims to provide a method and apparatus for generating HE (High Efficiency) PPDU or EHT (Extremely High Throughput) PPDU using different information contained in trigger frames transmitted from AP (Access Point).

[0011] The technical problems to be addressed herein are not limited to those mentioned above, and other technical problems not mentioned above will be clearly understood by those with ordinary skill in the art to which the present invention pertains from the following description. [Means for solving the problem]

[0012] A terminal in a wireless communication system that transmits a TB PPDU (Trigger Based Physical Layer Protocol Data Unit), which is a response frame, based on a trigger frame, includes a communication module and a processor that controls the communication module. The processor receives a trigger frame from an AP (Access Point), the trigger frame includes a common information field containing a first plurality of space reuse fields, and based on the identification information of the trigger frame, it is determined whether or not it includes an additional information field containing a second plurality of space reuse fields. As a response to the trigger frame, the processor transmits a response frame generated based on information obtained from the first plurality of space reuse fields or the second plurality of space reuse fields, and whether the response frame is generated based on the first plurality of space reuse fields or the second plurality of space reuse fields is determined based on the format associated with the trigger frame.

[0013] Furthermore, in the present invention, when the format associated with the trigger frame is the EHT (Extremely High Throughput) format, the response frame is generated based on information obtained from the second plurality of spatial reuse fields.

[0014] Furthermore, in the present invention, when the format associated with the trigger frame is the HE (High Efficiency) format, the response frame is generated based on information obtained from the first plurality of spatial reuse fields.

[0015] Furthermore, in the present invention, whether the response frame is generated based on information obtained from the first plurality of spatial reuse fields or based on information obtained from the second plurality of spatial reuse fields is determined based on the position on the frequency axis of the resource unit to which the response frame is transmitted.

[0016] Furthermore, in the present invention, the trigger frame further includes a bandwidth field, an additional bandwidth field, and a resource allocation field that indicates the resource unit to which the response frame is transmitted.

[0017] Furthermore, in the present invention, the processor recognizes the resource unit to which the response frame is transmitted based on the resource allocation field, and generates a response frame based on information obtained from the first plurality of space reuse fields or the second plurality of space reuse fields based on the position of the resource unit on the frequency axis to which the response frame is transmitted.

[0018] Furthermore, in the present invention, the trigger frame further includes a puncturing mode field that indicates whether or not puncturing occurs in the bandwidth indicated by the bandwidth field and / or the additional bandwidth field, and the location of the puncture.

[0019] Furthermore, in the present invention, when the response frame is generated based on the second plurality of space reuse fields, the response frame is transmitted with a bandwidth indicated by the bandwidth field included in the common information field and the additional bandwidth field included in the additional information field.

[0020] Furthermore, in the present invention, the response frame includes a plurality of spatial reuse fields, each of which is configured based on information obtained from the corresponding first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

[0021] Furthermore, in the present invention, whether or not the trigger frame includes the additional information field is determined by whether or not the value of a specific subfield indicating whether or not the common information field includes the additional information field, and / or the value of the identifier of the additional information field, is set to a specific value.

[0022] Furthermore, in the present invention, the response frame is a TB PPDU (Trigger based Physical layer Protocol Data Unit), the TB PPDU is aggregated with at least one TB PPDU transmitted from at least one other terminal instructed to transmit a TB PPDU by the trigger frame, and transmitted in the form of an A(aggregated)-PPDU, the at least one TB PPDU is generated based on the first plurality of spatial reuse fields or the second plurality of spatial reuse fields, and the TB PPDU and the at least one TB PPDU are generated based on different spatial reuse fields.

[0023] The present invention also provides a method comprising the steps of: receiving a trigger frame from an Access Point (AP), wherein the trigger frame includes a common information field containing a first plurality of spatial reuse fields, and whether or not it includes an additional information field containing a second plurality of spatial reuse fields is identified based on the identification information of the trigger frame; and transmitting a response frame as a response to the trigger frame, wherein whether or not the response frame is generated based on the first plurality of spatial reuse fields or based on the second plurality of spatial reuse fields is determined based on a format associated with the trigger frame. [Effects of the Invention]

[0024] According to an embodiment of the present invention, by using a trigger frame and transmitting information for generating TB PPDUs in different formats to different fields respectively, it is possible to indicate the transmission of multi-format TB PPDUs by one signaling.

[0025] Also, according to an embodiment of the present invention, by including information for spatial reuse for TB PPDUs in different formats in different fields of the trigger frame according to each format and transmitting them, the resolution of the spatial reuse represented by the TB PPDU is increased.

[0026] Also, according to an embodiment of the present invention, since the resolution of the spatial reuse represented by the TB PPDU is increased, the spatial reuse efficiency of the OBSS (Overlapping Basic Service Set) is improved.

[0027] Also, according to an embodiment of the present invention, by transmitting the trigger frame on a discontinuous channel, it is possible to allow a plurality of STAs to transmit TB PPDUs.

[0028] The effects obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those with ordinary knowledge in the technical field to which the present invention pertains from the following description.

Brief Description of the Drawings

[0029] [Figure 1] It is a diagram showing a wireless LAN system according to an embodiment of the present invention. [Figure 2] It is a diagram showing a wireless LAN system according to another embodiment of the present invention. [Figure 3] It is a diagram showing the configuration of a station according to an embodiment of the present invention. [Figure 4] It is a diagram showing the configuration of an access point according to an embodiment of the present invention. [Figure 5]This diagram schematically illustrates the process by which STA establishes a link with AP. [Figure 6] This diagram illustrates the CSMA (Carrier Sense Multiple Access) / CA (Collision Avoidance) method used in wireless LAN communication. [Figure 7] This shows the PPDU format for an extremely high throughput (EHT) wireless LAN according to one embodiment of the present invention. [Figure 8] The U-SIG field of a TB PPDU according to one embodiment of the present invention is shown. [Figure 9] An example of a trigger format according to one embodiment of the present invention is shown. [Figure 10] An example of the configuration of the common information field of a trigger frame according to one embodiment of the present invention is shown. [Figure 11] An example of the configuration of an additional information field using the trigger frame format according to one embodiment of the present invention is shown. [Figure 12] An example of a spatial reuse field and a puncturing mode field for uplink transmission according to one embodiment of the present invention is shown. [Figure 13] An example of transmission of a trigger frame and a trigger frame-based TB PPDU according to one embodiment of the present invention is shown. [Figure 14A] Further examples of the transmission of a trigger frame and a trigger frame-based TB PPDU according to one embodiment of the present invention are shown. [Figure 14B] Further examples of the transmission of a trigger frame and a trigger frame-based TB PPDU according to one embodiment of the present invention are shown. [Figure 15] This flowchart shows an example of a method for selecting a space reuse field to generate a TB PPDU based on a trigger frame according to one embodiment of the present invention. [Figure 16]An example of spatial reuse operation based on the number of spatial reuse fields in a frequency band according to one embodiment of the present invention is shown. [Figure 17] An example of a method for transmitting a trigger frame according to one embodiment of the present invention is shown. [Figure 18] An example of a TB PPDU including a puncturing mode according to one embodiment of the present invention is shown. [Figure 19] An example of a resource unit allocation and TB PPDU response procedure using a trigger frame according to one embodiment of the present invention is shown. [Figure 20] An example of a method for receiving TB PPDU based on a trigger frame according to one embodiment of the present invention is shown. [Figure 21] Further examples of a method for receiving TB PPDU based on a trigger frame according to one embodiment of the present invention are shown below. [Figure 22] Further examples of a method for receiving TB PPDU based on a trigger frame according to one embodiment of the present invention are shown below. [Figure 23] Further examples of a method for receiving TB PPDU based on a trigger frame according to one embodiment of the present invention are shown below. [Figure 24] An example of a user information field in a trigger frame according to one embodiment of the present invention is shown. [Figure 25] This document presents an example of a method for transmitting a TB PPDU based on a trigger frame according to one embodiment of the present invention. [Figure 26] An example of the format of the U-SIG field of a TB PPDU according to one embodiment of the present invention is shown. [Figure 27] This document shows an example of the configuration and signaling of a resource unit for transmitting TB PPDU according to one embodiment of the present invention. [Figure 28] This document presents an example of puncturing modes and segment position signaling using TB PPDU according to one embodiment of the present invention. [Figure 29]This document presents an example of setting up and using a subchannel for transmitting TB PPDH according to one embodiment of the present invention. [Figure 30] An example of signal detection for TB PPDU as a response to a trigger frame according to one embodiment of the present invention is shown. [Figure 31] This example illustrates the application of different thresholds to regions where reception is expected in the signal detection process for a TB PPDU according to one embodiment of the present invention. [Figure 32] An example of an error correction method for signal detection according to one embodiment of the present invention is shown. [Figure 33] This flowchart shows an example of how a non-AP STA according to one embodiment of the present invention transmits a response frame to a trigger frame. [Figure 34] This flowchart shows an example of how an AP STA according to one embodiment of the present invention receives a response frame to a trigger frame. [Modes for carrying out the invention]

[0030] The terminology used herein has been selected to the greatest extent possible from currently widely used general terms, taking into account the function of the present invention; however, this may differ depending on the intent, conventions, or emergence of new technologies of the articulate persons in the relevant field. In addition, in certain cases, the applicant has arbitrarily selected some terms, and in such cases, the meaning of these terms will be described in the relevant section of the invention description. Therefore, it should be made clear that the terms used herein are not merely names of terms, but should be interpreted based on the substantive meaning of the terms and the content of this specification as a whole.

[0031] Throughout the specification, when one component is described as being "connected" to another, this includes not only cases where they are "directly connected," but also cases where they are "electrically connected" with other components in between. Furthermore, when a component is described as "containing" a particular component, this means, unless otherwise stated, that it may contain other components rather than excluding them. In addition, limitations such as "greater than or equal to" or "less than or equal to" a specific critical value may be appropriately replaced by "greater than" or "less than" depending on the embodiment. Hereinafter, the terms "field" and "subfield" may be used interchangeably.

[0032] Figure 1 shows a wireless LAN system according to one embodiment of the present invention.

[0033] A wireless LAN system includes one or more Basic Service Sets (BSS), 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), and Figure 1 shows an infrastructure BSS.

[0034] As shown in Figure 1, the infrastructure BSS BSS1, BSS2 includes one or more stations STA1, STA2, STA3, STA4, STA5, access points AP-1, AP-2 which are stations that provide distribution services, and a distribution system DS that connects multiple access points AP-1, AP-2.

[0035] A Station (STA) is any device that includes Medium Access Control (MAC) and a Physical Layer interface to a wireless medium in accordance with the IEEE 802.11 standard, and in a broad sense includes not only non-AP stations but also all access points (APs). In this specification, "terminal" is used to refer to non-APs, APs, or both. A station for wireless communication includes a processor and a communication unit, and depending on the embodiment, further includes a user interface unit and a display unit, etc. The processor generates frames to be transmitted over the wireless network or processes frames received over the wireless network, and performs various other processing for controlling the station. The communication unit is functionally connected to the processor and sends and receives frames over the wireless network for the station. In this invention, "terminal" is used as a term that includes user equipment (UE).

[0036] An Access Point (AP) is an individual device that provides connectivity to a distribution system (DS) via a wireless medium for stations associated with it. In an infrastructure BSS, communication between non-AP stations is generally conducted via APs, but direct communication is possible between non-AP stations if a direct link is configured. In this invention, AP is used as a concept that includes PCP (Personal BSS Coordination Point), but in a broader sense, it includes all concepts such as central controllers, base stations (BS), node B, BTS (Base Transceiver System), or site controllers. In this invention, AP is also called a base wireless communication terminal, but in a broader sense, base wireless communication terminal is used as a term that includes APs, base stations, eNBs (eNodeBs), and transmission points (TPs). Furthermore, base wireless communication terminals include various forms of wireless communication terminals that allocate and schedule communication medium resources in communication with multiple wireless communication terminals.

[0037] Multiple infrastructure BSSs are connected to each other via a distribution system DS. In this case, multiple BSSs connected via the distribution system are called an Extended Service Set (ESS).

[0038] Figure 2 shows an independent BSS, which is a wireless LAN system according to another embodiment of the present invention. In the embodiment of Figure 2, redundant explanations are omitted for parts that are the same as or corresponding to the embodiment of Figure 1.

[0039] As shown in Figure 2, BSS3 is an independent BSS and does not include APs, so all stations (STA6, STA7) are not connected to APs. An independent BSS is not allowed to connect to a distribution system and forms a self-contained network. In an independent BSS, each station (STA6, STA7) is directly connected to one another.

[0040] Figure 3 is a block diagram showing the configuration of station 100 according to one embodiment of the present invention. As shown, station 100 according to the embodiment of the present invention includes a processor 110, a communication unit 120, a user interface unit 140, a display unit 150, and a memory 160.

[0041] First, the communication unit 120 transmits and receives wireless signals such as wireless LAN packets and may be incorporated into the station 100 or provided externally. According to one embodiment, the communication unit 120 may include at least one communication module using different frequency bands. For example, the communication unit 120 may include communication modules of different frequency bands such as 2.4GHz, 5GHz, 6GHz, and 60GHz. According to one embodiment, the station 100 may include a communication module using a frequency band of 7.125GHz or higher and a communication module using a frequency band of 7.125GHz or lower. Each communication module can perform wireless communication with an AP or external station based on the wireless LAN standard of the frequency band supported by the communication module. Depending on the performance and requirements of the station 100, the communication unit 120 may operate only one communication module at a time or operate multiple communication modules together simultaneously. When the station 100 includes multiple communication modules, each communication module may be provided in an independent form, or the multiple modules may be integrated as a single chip. In embodiments of the present invention, the communication unit 120 can represent an RF (Radio Frequency) communication module that processes RF signals.

[0042] Next, the user interface 140 includes various forms of input / output means provided in the station 100. In other words, 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. The user interface unit 140 also outputs based on instructions from the processor 110 using various output means.

[0043] Next, the display unit 150 outputs an image to the display screen. The display unit 150 outputs various display objects, such as content generated by the processor 110 or user interfaces based on control instructions from the processor 110. The memory 160 stores control programs used by the station 100 and various data associated with them. Such control programs include connection programs necessary for the station 100 to connect with APs or external stations.

[0044] The processor 110 of the present invention executes various instructions or programs and processes data within the station 100. The processor 110 also controls each unit of the station 100 and controls the transmission and reception of data between 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 setup message transmitted by the AP. The processor 110 also reads information regarding the priority conditions of the station 100 contained in the communication setup message and requests a connection to the AP based on 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, depending on the embodiment, may refer to a control unit for individually controlling a part of the station 100's configuration, such as the communication unit 120. In other words, the processor 110 may be a modem or a modulator and / or demodulator that modulates and demodulates the wireless signals transmitted and received from the communication unit 120. The processor 110 controls various operations of wireless signal transmission and reception of the station 100 according to an embodiment of the present invention. A detailed embodiment relating to this will be described later.

[0045] The station 100 shown in Figure 3 is a block diagram according to one embodiment of the present invention, and the separately shown blocks represent logically distinguished elements of the device. Therefore, the above-mentioned elements of the device are mounted on one chip or multiple chips depending on the device design. For example, the processor 110 and the communication unit 120 may be integrated and implemented on a single chip, or they may be implemented on separate chips. Furthermore, in the embodiment of the present invention, some components of the station 100, such as the user interface unit 140 and the display unit 150, may be selectively provided in the station 100.

[0046] Figure 4 is a block diagram showing the configuration of AP200 according to one embodiment of the present invention. As shown, AP200 according to an embodiment of the present invention includes a processor 210, a communication unit 220, and a memory 260. In Figure 4, redundant explanations are omitted for parts of the AP200 configuration that are the same as or correspond to the configuration of station 100 in Figure 3.

[0047] Referring to Figure 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 Figure 3, the communication unit 220 of the AP 200 can also include a plurality of communication modules using different frequency bands. That is, the AP 200 according to an embodiment of the present invention can include two or more communication modules using different frequency bands, for example, 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz. Preferably, the AP 200 can include a communication module using a frequency band of 7.125 GHz or higher and a communication module using a frequency band of 7.125 GHz or lower. Each communication module can communicate wirelessly with the station based on the wireless LAN standard of the frequency band supported by the communication module. Depending on the performance and requirements of the AP 200, the communication unit 220 can operate only one communication module at a time or operate multiple communication modules together simultaneously. In an embodiment of the present invention, the communication unit 220 can represent an RF (Radio Frequency) communication module that processes RF signals.

[0048] Next, the memory 260 stores the control program used by the AP200 and various data associated with it. Such a control program includes a connection program that manages station connections. The processor 210 controls each unit of the AP200 and controls the transmission and reception of data between units. According to one embodiment of the present invention, the processor 210 executes the program for connecting with stations stored in the memory 260 and transmits a communication setting message to one or more stations. In this case, the communication setting message includes information regarding the connection priority conditions of each station. The processor 210 also performs connection settings in response to connection requests from stations. According to one embodiment, the processor 210 is a modem or modulation / demodulation unit that modulates and demodulates the wireless signals transmitted and received from the communication unit 220. The processor 210 controls various operations of wireless signal transmission and reception of the AP200 according to the embodiment of the present invention. A detailed embodiment relating thereto will be described later.

[0049] Figure 5 is a schematic diagram illustrating the process by which STA establishes a link with AP.

[0050] Referring to Figure 5, the link between STA100 and AP200 is established through three main steps: scanning, authentication, and association. First, the scanning step is the step in which STA100 obtains connection information for the BSS operated by AP200. There are two methods for performing scanning: passive scanning, which obtains information using only the beacon message S101 that AP200 periodically transmits, and active scanning, in which STA100 transmits a probe request S103 to the AP, receives a probe response S105 from the AP, and obtains connection information.

[0051] In the scanning step, STA100, having successfully received wireless connection information, transmits an authentication request (S107a), receives an authentication response from AP200 (S107b), and performs the authentication step. After the authentication step is performed, STA100 transmits an association request (S109a), receives an association response from AP200 (S109b), and performs the association step. In this specification, "association" basically means wireless coupling, but the present invention is not limited to this, and in a broad sense, coupling includes both wireless and wired coupling.

[0052] On the other hand, an additional 802.1X-based authentication step S111 and an IP address acquisition step S113 via DHCP are performed. In Figure 5, Server 300 is a server that processes authentication between STA100 and the 802.1X-based system, and may be physically connected to AP200 or exist as a separate server.

[0053] Figure 6 shows the CSMA (Carrier Sense Multiple Access) / CA (Collision Avoidance) method used in wireless LAN communication.

[0054] A terminal performing wireless LAN communication checks whether a channel is busy or not by performing carrier sensing before transmitting data. If a wireless signal above a certain strength is detected, the channel is determined to be busy, and the terminal delays access to that channel. This process is called Clear Channel Assessment (CCA), and the level at which the detection of the signal is determined is called the CCA threshold. If a wireless signal above the CCA threshold is received by the terminal and the terminal is the recipient, the terminal processes the received wireless signal. On the other hand, if no wireless signal is detected from the channel, or if a wireless signal below the CCA threshold is detected, the channel is determined to be idle.

[0055] If a channel is determined to be idle, each terminal with data to transmit performs a backoff procedure after a certain period of time, such as an IFS (Inter Frame Space) or PIFS (PCF IFS), depending on the status of each terminal. In this embodiment, the AIFS is used as a replacement for the conventional DIFS (DCF IFS). Each terminal waits, decreasing its slot time by a random number determined for that terminal during the interval of the channel's idle state, and the terminal that has exhausted all of its slot time attempts to access the channel. The period in which each terminal performs this backoff procedure is called the competition window period.

[0056] If a specific terminal successfully accesses the channel, it transmits data through 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. In one embodiment, the random number newly assigned to each terminal is determined within a range twice the range (competition window, CW) of the random number previously assigned to that terminal (2*CW). Meanwhile, each terminal attempts access again in the next competition window interval by performing a further backoff procedure, but 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 collisions with each other for a specific channel.

[0057] Hereinafter, in the present invention, a terminal may be referred to as a non-AP STA, AP STA, STA, receiving device, or transmitting device, and the present invention is not limited thereto.

[0058] <Various PPDU Format Examples>

[0059] Figure 7 shows the PPDU format of an extremely high throughput (EHT) wireless LAN according to one embodiment of the present invention.

[0060] Figure 7(a) shows an example of a single / multi-user transmitted PPDU format, and (b) shows an example of a TB (trigger-based) PPDU format. Figure 7(c) shows an example of the HE (High Efficient) PPDU format in the previous generation Wi-Fi 802.11ax.

[0061] As shown in Figures 7(a) to 7(c), a PPDU is divided into a preamble and a data portion. The preamble can commonly include legacy fields for backward compatibility, such as L-STF (Legacy Short Training field), L-LTF (Legacy Long Training field), L-SIG (Legacy Signal field), and RL-SIG (Repeated Legacy Signal field).

[0062] Such legacy fields may be included not only in the EHT PPDU used in 802.11be, as shown in Figures 7(a) to (c), but also in the preamble of the HE PPDU in earlier versions of 802.11ax.

[0063] Referring to Figures 7(a) and 7(b), in addition to the legacy fields mentioned above, the EHT PPDUs, namely 11be MU / SU PPDU and 11be TB PPDU, can further include a U-SIG (Universal Signal field), and as shown in Figure 7(a), the SU / MU PPDU can further include an EHT-SIG field.

[0064] U-SIG is a field newly introduced in 11be, an ultra-high-speed communication standard, and is a field commonly included in subsequent generations of 802.11 standard PPDUs, including 11be. The U-SIG field may continue to be included in EHT PPDUs and subsequent generations of wireless LAN PPDUs, and plays a role in distinguishing which generation of PPDU it is, including 11be. The U-SIG field can transmit a total of 52 bits of information using 64FFT-based OFDM 2 symbols. The analysis of some fields in the U-SIG field may vary depending on the type of PPDU, whether it is multiple user transmission or not, and whether it is OFDMA transmission or not.

[0065] The EHT-SIG field may functionally consist of an EHT-VD common field, an EHT-RU (resource unit) allocation subfield, and an EHT-user specific field. The parsing of some fields may vary or some fields may be omitted depending on the PPDU type, whether it is a multiple-user transmission or not, and whether it is an OFDMA transmission or not.

[0066] In this case, the EHT-VD common field and the EHT-RU assignment field can be combined and called the EHT-common field. The configuration and modified (compressed or omitted) forms of the EHT-SIG field will be described in detail later using examples. The EHT-RU assignment field can be called the RU assignment field.

[0067] The TB PPDU shown in Figure 7(b) is a trigger-based PPDU, meaning a PPDU based on a trigger frame. That is, the PPDU shown in Figure 7(b) is a PPDU transmitted as a response to a trigger frame, and its preamble contains only the U-SIG field after the legacy field, and not the EHT-SIG field. Therefore, unlike the MU / SU PPDH in Figure 7(a), the U-SIG does not contain information for decoding the EHT-SIG, but may contain information such as spatial reuse and puncture mode information to indicate the presence and pattern of puncture.

[0068] Referring to Figures 7(a) to (c), the terminal can first receive and decode the PPDU preamble, and then receive data based on the preamble. For example, the terminal can recognize whether the PPDU to be received is an SU or MU PPDU from the U-SIG field included in the preamble, and based on this, it can recognize the number of content channels that make up the EHT-SIG field. Subsequently, the terminal can decode the recognized EHT-SIG field to recognize the RU assigned by the RU assignment subfield, and then receive data with the recognized RU.

[0069] Figure 8 shows the U-SIG field of a TB PPDU according to one embodiment of the present invention.

[0070] Referring to Figure 8, a TB PPDU based on a trigger frame may be divided into a preamble and data. The preamble may include a U-SIG field common to all PPDUs and an EHT-SIG field whose field configuration and inclusion vary depending on the type of PPDU. In this case, the U-SIG field may include a spatial reuse field for spatial reuse (SR) for PPDU transmission, and a puncturing mode field to indicate the presence and location of puncturing depending on the mode.

[0071] Space reuse refers to a method of efficiently using space resources by having the STA adjust and / or set an appropriate CCA level depending on the situation, and then determine whether the channel is idle or occupied based on the adjusted and / or set CCA level before transmitting a signal. In other words, the STA does not apply the same CCA level uniformly to all channels, and when it is determined that the signal transmitted by the STA during SR is not causing significant interference to other STAs, it adjusts the CCA level to a lower level (or relaxes the criteria for determining whether a channel is idle or not), thereby using transmission resources more efficiently.

[0072] Figure 8(a) shows an example of the configuration of the U-SIG field. As shown in Figure 8(a), the U-SIG field may consist of a version-independent field that is not affected by the PHY version, a version-dependent field that is affected by the PHY version, a CRC field (4 bits), and a Tail field (6 bits).

[0073] Version-independent fields may include a PHY VER field (3 bits) for distinguishing the PHY version, a UL / DL field for indicating the UL (Uplink) / DL (Downlink) of the PPDU, a BSS color field, a TXOP field, and a PPDU BW field.

[0074] The BSS color field indicates the BSS Color index of the device transmitting and receiving the PPDU, and the TXOP field contains timing information associated with the time when the PPDU transmission ends. The PPDU BW field may include bandwidth information on which the PPDU is transmitted. If some frequency bands in the bandwidth indicated by the PPDU BW field are punctured or not allocated, those frequency bands do not need to be used for PPDU transmission. In this case, the PPDU BW may further indicate information about the punctured portion of the bandwidth.

[0075] Version-independent fields are not modified by the PPDU type, and therefore may be included in MU / SU PPDUs as well as TB PPDUs, and may also be included in PPDUs used in standards from 11be onwards.

[0076] Version-dependent fields may include a PPDU type field (1b+a bits) and a PPDU type specific field. The PPDU type field indicates the type of PPDU, and the subfields included in the PPDU type specific field may change depending on the type of PPDU.

[0077] Figure 8(b) shows an example of a PPDU type identification field for a TB PPDU. Specifically, the PPDU type identification field for a TB PPDU may include a space reuse field for space reuse and a puncturing mode field for indicating the presence and / or location of punctures.

[0078] In this case, the spatial reuse field may contain multiple fields depending on the bandwidth. For example, as shown in Figure 8(b), four fields, spatial reuse fields 1 to 4, may be included in the PPDU type-specific field of the TB PPDU. The value of each spatial reuse field may be encoded corresponding to each frequency domain within the bandwidth indicated by the PPDU BW field of the U-SIG field.

[0079] For example, if the PPDU BW indicates 20MHz, all of the space reuse fields 1-4 may be encoded to correspond to the 20MHz indicated by the PPDU BW. Alternatively, if the PPDU BW field indicates a bandwidth of 40MHz, two space reuse fields (e.g., 1 and 3) may be encoded to correspond to Low 20MHz relative to the center frequency of 40MHz, and the remaining two space reuse fields (e.g., 2 and 4) may be encoded to correspond to High 20MHz.

[0080] Alternatively, if the PPDU BW field indicates a bandwidth of 80 MHz, each of the four space reuse fields may be encoded to correspond to four 20 MHz of 80 MHz, respectively.

[0081] If the PPDU BW field indicates a bandwidth of 160 MHz, each of the four space reuse fields may be encoded to correspond to four 40 MHz of 160 MHz, respectively.

[0082] When the PPDU BW field indicates a bandwidth of 260 MHz, each of the four spatial reuse fields may be encoded to correspond to three of the twelve 20 MHz in 240 MHz. In this case, the three 20 MHz corresponding to Spatial Reuse 1 may be the three 20 MHz channels having the lowest frequency components within the 240 MHz bandwidth. Alternatively, each of the remaining three spatial reuse fields may be encoded to correspond to each of the three 80 MHz in 240 MHz, and the remaining spatial reuse field may be encoded to the same value as the three encoded spatial reuse fields.

[0083] When the PPDU BW field indicates a bandwidth of 320 MHz, each of the four spatial reuse fields may be encoded to correspond to four 80 MHz of 320 MHz. In this case, the 80 MHz corresponding to Spatial Reuse 1 may have the lowest frequency component of 320 MHz, and the 80 MHz corresponding to Spatial Reuse 4 may have the highest frequency component.

[0084] The puncturing mode field indicates whether puncturing is present and / or at what location, and may be encoded to the same value as the puncturing mode field of the trigger frame.

[0085] At this time, the discontinuous form of the PPDU indicated by the trigger frame's puncturing mode field and the combined form of the TB PPDU transmitted by multiple users on the uplink (the form in which the PPDU is received) may change. The reason why the discontinuous form of the PPDU indicated by the puncturing mode and the combined form of the TB PPDU change is that some or all of the RUs specified in RA-RU (Random Access, RU) may not be occupied by STA, and further discontinuous forms (unutilized bandwidth forms) not indicated by the puncturing mode may occur.

[0086] The Puncturing Mode field of the TB PPDU may be used to identify which bandwidths within the UL BW of the TB PPDU are (deterministically) not being utilized by adjacent BSS APs and STAs.

[0087] Figure 8(c) shows an example of a user-specific field in a TB PPDU. Referring to Figure 8(c), a TB PPDU may contain different space reuse fields depending on the location (bandwidth region) of the transmitted RU or the type of TB PPDU. That is, the space reuse fields included in a TB PPDU may be differentiated depending on the transmission location and / or type of the TB PPDU.

[0088] Specifically, as shown in Figure 8(b), if the spatial reuse fields of the TB PPDU for a 320 MHz uplink bandwidth consist of Spatial Reuse 1, 2, 3, and 4, and only four exist, then each spatial reuse field corresponds to 80 MHz.

[0089] However, by differentiating the spatial reuse fields of the primary and secondary TB PPDUs transmitted, a total of eight spatial reuse fields may correspond to a 320 MHz uplink bandwidth. Therefore, each of the Spatial Reuse 1 to 8 spatial reuse fields included in the two types of TB PPDUs, based on the frequency domain in which the PPDU is transmitted, can correspond to 40 MHz of the UL TB PPDU BW (the BW represented by the combined TB PPDUs transmitted by each STA).

[0090] In other words, when a non-AP STA transmits a TB PPDU indicated by a trigger frame sent from an AP STA, the non-AP STA may configure and transmit the spatial reuse field and puncturing mode field included in the PPDU type-specific field differently from each other, depending on the location of the RU to which the TB PPDU is transmitted and / or the type of the TB PPDU.

[0091] For example, a non-AP STA may include Spatial Reuse 1-4, which are spatial reuse fields, in the PPDU type-specific field of a TB PPDU if the RU where the TB PPDU is transmitted is a first-type TB PPDU with a primary frequency of 160 MHz. However, a non-AP STA may also include Spatial Reuse 5-8, which are spatial reuse fields, in the PPDU type-specific field of a TB PPDU if the RU where the TB PPDU is transmitted is a second-type TB PPDU with a secondary frequency of 160 MHz.

[0092] The first and second types may be distinguished by the PHY version of the TB PPDU, or they may be types of PPDUs that conform to the Wi-Fi standard. For example, the first type may be an HE TB PPDU, and the second type may be an EHT-TB PPDU.

[0093] Non-AP STAs can configure Spatial Reuse 1-8 based on information contained in the trigger frame, and information for configuring the spatial reuse fields may be contained in different fields of the trigger frame depending on the location of the RU from which the TB PPDU is sent and / or the type of TB PPDU.

[0094] As shown in Figure 8(b), when a single spatial reuse field corresponds to 80 MHz, if the spatial reuse of other BSSs is restricted by a portion of the 80 MHz (20 MHz), the question arises as to whether the remaining reusable 60 MHz should also be restricted. Therefore, in order to improve the efficiency of spatial reuse, the size of the bandwidth corresponding to a single spatial reuse field may be reduced, and for that purpose, the number of spatial reuse fields corresponding to each bandwidth may also be increased.

[0095] However, when multiple space reuse fields are set and transmitted, the size of the U-SIG field increases, increasing the signaling overhead. Therefore, as shown in Figure 8(c), setting different space reuse fields between TB PPDUs transmitted at primary 160MHz and secondary 160MHz allows for the setting and transmission of more space reuse fields without increasing signaling overhead.

[0096] According to one embodiment of the present invention, after receiving a trigger frame indicating an uplink bandwidth of 320 MHz, the TB PPDU of a single STA to be transmitted may be transmitted using only one of either a primary 160 MHz or a secondary 160 MHz RU.

[0097] According to yet another embodiment of the present invention, after receiving a trigger frame indicating an uplink bandwidth of 240 MHz, the TB PPDU of a single STA to be transmitted may be transmitted using only one of either a Low 160 MHz or High 160 MHz RU.

[0098] Referring to Figure 8(c), a TB PPDU transmitted in a RU within a primary 160 MHz may include four space reuse fields in the PPDU type-specific field, each of which may correspond to one of four 40 MHz RUs within a primary 160 MHz.

[0099] Furthermore, a TB PPDU transmitted on a RU within the secondary 160 MHz may include four space reuse fields in the PPDU type-specific field, each of which may correspond to one of the four 40 MHz RUs within the secondary 160 MHz.

[0100] When the bandwidth indicated by the PPDU BW is 240 MHz, the primary and secondary BWs may have a bandwidth of 80 MHz. In this case, each of the space reuse fields (e.g., four space reuse fields) of the TB PPDU transmitted on the Primary 80 MHz and / or Secondary 80 MHz RU may correspond to each of the subchannels (20 MHz) within 80 MHz.

[0101] In this embodiment, the PPDU type identification field may further include a puncturing mode field that indicates the puncturing mode, in addition to the spatial reuse field. Depending on whether the location of the RU transmitting the TB PPDU, which is in the primary BW or secondary BW, is in the STA that received the trigger frame in a manner similar to the spatial reuse field, different puncturing mode fields may be included. That is, the TB PPDU may include puncturing mode field 1 and puncturing mode field 2, which are set to be different from each other depending on the bandwidth (or segment) in which the RU transmitting the TB PPDU is located.

[0102] For example, as shown in Figure 8(c), puncturing mode field 1 may be included in a TB PPDU transmitted at primary 160 MHz and represent a discontinuous channel configuration at primary 160 MHz, while puncturing mode field 2 may be included in a TB PPDU transmitted at secondary 160 MHz and represent a discontinuous channel configuration at secondary 160 MHz.

[0103] As shown in Figure 8(c), when fields indicating the puncturing mode are individually set and transmitted for each bandwidth, it is possible to signal the form of discontinuous channels across the entire uplink bandwidth with higher resolution compared to the method of signaling discontinuous channels with a single puncturing mode field as shown in Figure 8(b).

[0104] <Trigger Frame Format>

[0105] Figure 9 shows an example of a trigger format according to one embodiment of the present invention.

[0106] Referring to Figure 9, a trigger frame can include a frame control field, a duration field, a resource allocation (RA) field, a Timing Advanced field, a Common Information field, a User information list field, a Padding field, and an FCS field. A trigger frame may omit some of the above fields, or it may include some additional fields.

[0107] The frame control field, duration field, RA field, and TA field are identical to the fields included in a standard MAC header in the 802.11 standard.

[0108] The common information field may contain information about various parameters used when a device to which a resource unit has been allocated by a trigger frame sends a TB PPDU in response.

[0109] The user information list may include at least one User Information field containing individual information for each STA. A Padding field may be included to allow time for the generation and preparation of the TB PPDU. If a receiving device's user information field is located later in the user information list, it may not have enough time to recognize its assigned RU, generate the TB PPDU, and transmit it. Therefore, by placing the Padding field as an appendage after the user information list field in the trigger frame, each receiving device can ensure sufficient time to recognize the RU and prepare the TB PPDU.

[0110] A receiving device that has received a trigger frame may, if the received trigger frame is a trigger frame that is to be sent to it, send a TB PPDU with the RU assigned by the trigger frame as a response to the transmitted trigger frame. If a trigger frame is sent to multiple receiving devices, the multiple receiving devices that received the trigger frame may send TB PPDUs simultaneously, and the TB PPDUs may be sent concatenated in the form of A (Aggregated)-PPDU. Also, if PPDUs are sent from multiple STAs as a response to a trigger frame and received in the form of A-PPDU, the formats of the concatenated TB PPDUs may be different from each other. For example, an HE TB PPDU and an EHT TB PPDU may be concatenated, or TB PPDUs of different types (or formats) may be concatenated and sent.

[0111] Figure 10 shows an example of the configuration of the common information field of a trigger frame according to one embodiment of the present invention.

[0112] The common information field can contain information / parameters that are common to all terminals receiving the trigger frame. As shown in Figure 10, the trigger type field indicates the trigger type of the trigger frame and may consist of 4 bits.

[0113] Table 1 below shows an example of trigger frame types based on the value of the trigger type field.

[0114] [Table 1]

[0115] Referring to Table 1, the four bits of the trigger type field are encoded from '0000' to '1111', individually indicating the type of each trigger frame. For example, the four bits of the trigger type field can indicate trigger frames of the following types, depending on the encoded value: Basic (0), Beamforming Report Poll (1), MU-BAR (2), MU-RTS (3), Buffer Status Report Poll (4), GCR MU-BAR (5), Bandwidth Query Report Poll (6), NDP Feedback Report Poll (7), EHT-Basic (8), EHT-Beamforming Report Poll (9), EHT-MU-BAR (10), MU-RTS (11), EHT-Buffer Status Report Poll (12), EHT-GCR MU-BAR (13), EHT-Bandwidth Query Report Poll (14), and EHT-NDP Feedback Report Poll (15).

[0116] Bit values ​​from '0' to '7' in the trigger type field can indicate the same trigger frame type as the trigger type field in HE (802.11ax). Therefore, when the value of the trigger frame type field, which indicates that the trigger frame is an HE trigger frame based on HE, is between '0' and '7', the trigger frame may be constructed identically to that of 802.11ax, and thus the common information field, trigger-dependent common information field, and user field may be constructed and encoded in the same format.

[0117] However, the type of trigger frame with bit values ​​from '8' to '15' specified by the trigger type field may only be indicated if the PHY version of the trigger frame is EHT(11be). That is, the bit value of the trigger type field may only be set to one of the values ​​from '8' to '15' if the trigger frame is an EHT trigger frame based on EHT. EHT trigger frames based on EHT with trigger type field values ​​from '8' to '15' may have the same functionality as the corresponding trigger frames from '0' to '7', respectively.

[0118] When the value of the trigger type field is between '8' and '15', it is an EHT trigger frame based on EHT, and therefore may contain different fields (e.g., additional information fields) than an HE trigger frame based on HE, where the value of the trigger type field is between '0' and '7'. For example, a trigger frame with a trigger type value between '8' and '15' may further include an additional bandwidth field, a puncturing mode field, and / or an additional UL space reuse field for additional space reuse. Such additional information fields may be used to apply newly added features to EHT (e.g., 240 / 320MHz operation, multiple RU allocation, etc.) to the operation based on the trigger frame.

[0119] Additional information fields may be added by extending fields that are functionally identical to fields included in trigger frames whose trigger type field value is '0' to '7', or by using the Reserved field.

[0120] As shown in Figure 10, the size of the UL BW field may vary depending on the value of the trigger type field. For example, when the value of the trigger type field is '0' to '7', the size of the UL BW field is 2 bits. However, when the value of the trigger type field is '8' to '15', the size of the UL BW field is 3 bits, which can represent six BW modes (20, 40, 80, 160 (80+80), 240 (160+80), 320 (160+160) MHz).

[0121] The size of the UL spatial reuse field may vary depending on the value of the trigger type field. For example, if the value of the trigger type field is between '0' and '7', the size of the UL spatial reuse field is 16 bits. However, if the value of the trigger type field is between '8' and '15', the UL spatial reuse field may consist of eight 4-bit spatial reuse fields, totaling 32 bits.

[0122] The reason for having a total of eight spatial reuse fields is that if only four spatial reuse fields were used for 240MHz or 320MHz PPDUs, as in the existing system, the bandwidth corresponding to each spatial reuse field would reach up to 80MHz, preventing efficient spatial reuse. Therefore, increasing the number of spatial reuse fields to eight allows for support up to 40MHz, enabling more efficient spatial reuse operation.

[0123] The UL HE-SIG-A2 Reserved field may be used as a Puncturing mode field when the Trigger Type is 8 to 15.

[0124] Figure 11 shows an example of the configuration of an additional information field in the trigger frame format according to one embodiment of the present invention.

[0125] Referring to Figure 11, the trigger frame may include an additional information field depending on whether it is based on HE or EHT, and the additional information field may further include additional information for the TB PPDU response based on the EHT trigger frame.

[0126] Specifically, when the value of the trigger type field included in the trigger frame is set to a value between '8' and '15', if the trigger frame is an EHT trigger frame, the trigger frame can further include an additional trigger dependent common information subfield, as shown in Figure 11, which is an additional information field.

[0127] As mentioned above, the additional information field may include an additional bandwidth field, a puncturing mode field, and / or an additional UL space reuse field for additional space reuse. In this case, the common information field other than the additional information field may have the same bit and field configuration for trigger frames where the trigger type field value is '0' to '7' and for trigger frames where the trigger type field value is '8' to '15'.

[0128] The additional information field shown in Figure 11 may be included in all EHT-based trigger frames where the trigger type field value is '8' to '15', and may be included along with BAR Control (20 octets) and BAR Information (20 octets) when the trigger type field value is '13' (EHT-GCR MU-BAR).

[0129] The additional information field contains additional information for generating an EHT TB PPDU when a PPDU is sent as a response to an EHT-based trigger frame. The additional information field may be located immediately after the common information field and may have a size of 1 or 2 bits.

[0130] Furthermore, a specific field located immediately before the additional information field can indicate whether or not the additional information field is included after the common information field. That is, if the value of the specific field is set to a specific value ('1' or '0'), the non-AP STA can recognize that the additional information field is included after the common information field. In this case, the trigger frame may be recognized as an EHT trigger frame, and the non-AP STA can respond with an EHT TB PPDU. If the specific field indicates that the additional information field is not included, the trigger frame may be recognized as an HE trigger frame, and the non-AP STA can respond with an HE TB PPDU. In this case, the specific field may have a size of 1 bit and may be 'B63', 'B53', or other bits.

[0131] Non-AP STA can determine whether an additional information field is included after the common information field by using the identifier of the additional information field in addition to a specific field. For example, if the value of the identifier of the additional information field (e.g., AID (association identifier)) is set to a specific value (e.g., AID=2007), it may be indicated that an additional information field is included after the common information field.

[0132] A non-AP STA can respond using an HE TB PPDU if the received trigger frame is an HE trigger frame, and can respond using either an HE TB PPDU or an EHT TB PPDU depending on the received trigger frame. In this case, if the location of the RU assigned to transmit the response frame to the trigger frame is in a bandwidth where the primary channel is not located, the non-AP STA can transmit only an EHT TB PPDU as a response to the trigger frame. That is, if the location of the assigned RU is in the primary bandwidth, the non-AP STA can respond with either an HE TB PPDU or an EHT TB PPDU depending on the configuration and type of the trigger frame, but if the location of the assigned RU is in the secondary bandwidth, the non-AP STA can respond with only an EHT TB PPDU.

[0133] For example, based on the format associated with the trigger frame (e.g., whether the user information field in the trigger frame is in HE or EHT format), a non-AP STA can respond with either a TB PPDU or an EHT TB PPDU. Specifically, after receiving a trigger frame, a non-AP STA will respond with an HE TB PPDU if the user information field in the trigger frame is in HE format. However, if the user information field in the trigger frame is in EHT format, the non-AP STA can respond with an EHT TB PPDU.

[0134] Additional information fields can be called special user information fields, and the fields included in additional information fields may be interpreted together with the fields included in common information.

[0135] The additional UL bandwidth (additional UL BW) field may be assigned one or two bits and may be interpreted in conjunction with the bandwidth field included in the common information field. That is, if the additional information field includes the additional UL bandwidth field, the non-AP STA can consider the additional UL bandwidth field in addition to the bandwidth field in the common information field to determine the bandwidth for transmitting the TB PPDU. In this case, the two bits of the bandwidth field can correspond to six of the eight (or sixteen) bandwidth modes that can be indicated by one (or two) bits of the additional UL BW field, respectively, which can correspond to 20, 40, 80, 160 (80+80), 240 (160+80), and 320 (160+160) MHz.

[0136] The additional UL space reuse field can signal values ​​for space reuse operations in frequency domains not indicated by the UL space reuse field in the common field. Since the UL space reuse field in the common information field contains four space reuse fields, and the additional UL space reuse field contains four other space reuse fields, a total of eight space reuse fields can be indicated for the entire bandwidth. That is, the multiple space reuse fields included in the common information field and the additional UL space reuse field included in the additional information field can each indicate frequency bands for space reuse operations across different bandwidths.

[0137] For example, if each of the space reuse fields included in the common information field indicates a frequency band for space reuse operation on the primary BW, then the additional space reuse field included in the additional information field can indicate a frequency band for space reuse operation on the secondary BW. Therefore, a non-AP STA can generate a TB PPDU using the space reuse field included in the common information of the trigger frame when transmitting a TB PPDU on the primary BW (or when the TB PPDU is an HE TB PPDU). However, a non-AP STA can generate a TB PPDU using at least one space reuse field included in the additional information field of the trigger frame when transmitting a TB PPDU on the secondary BW (or when the TB PPDU is an EHT TB PPDU).

[0138] In other words, when a non-AP STA sends a TB PPDU in response to a trigger frame, it can generate the TB PPDU using at least one spatial reuse field contained in different fields, depending on whether the responding TB PPDU is an HE TB PPDU or an EHT TB PPDU.

[0139] The puncturing mode field can signal the discontinuous configuration of the PPDU from which the trigger frame was transmitted. The trigger frame may be transmitted using discontinuous channels of the operating BW, excluding certain channels, and the discontinuous channel configuration of the RU from which the trigger frame was transmitted may be indicated by the puncturing mode field.

[0140] Furthermore, the puncturing mode field of the trigger frame may be encoded using the same mode as the puncturing mode field of the SU PPDU. Alternatively, instead of the puncturing mode field, a bitmap (8-bit or 16-bit bitmap) may be included to indicate whether each 20MHz channel is used to signal the discontinuous channel configuration of the entire PPDU BW.

[0141] Figure 12 shows an example of a spatial reuse field and a puncturing mode field for uplink transmission according to one embodiment of the present invention.

[0142] Figure 12(a) shows one embodiment of the UL space reuse field for uplink space reuse operation, consisting of a total of eight space reuse fields. Of the eight space reuse fields seen in the trigger frame for a bandwidth of 320 (or 160+160) MHz, four can represent space reuse values ​​corresponding to Low 160 or 80 MHz, and the remaining four can represent space reuse values ​​corresponding to High 160 or 80 MHz.

[0143] In this case, the multiple spatial reuse fields shown in Figure 12(a) may be divided and included in the UL spatial reuse fields included in the common field and the additional UL spatial reuse fields included in the additional information field. That is, some of the multiple spatial reuse fields may be included in the UL spatial reuse fields included in the common field, and the remaining spatial reuse fields may be included in the additional UL spatial reuse fields included in the additional information field.

[0144] Each space reuse field consists of 4 bits and can represent a space reuse value applicable to a bandwidth of up to 40 MHz.

[0145] For example, if the total bandwidth is 320 MHz, the four space reuse fields corresponding to the primary 160 MHz may correspond to Low 40 MHz of Low 80 MHz, High 40 MHz of Low 80 MHz, Low 40 MHz of High 80 MHz, and High 40 MHz of High 80 MHz, respectively. Similarly, the four space reuse fields corresponding to High 160 MHz may correspond to Lowest 40, Low 40, High 40, and Highest 40 MHz of High 160 MHz, respectively.

[0146] When the total bandwidth is 240 (or 160+80 or 80+160) MHz, four of the eight spatial reuse fields included in the trigger frame may correspond to Low 160 MHz or Low 80 MHz, and the remaining four spatial reuse fields may correspond to High 80 MHz or High 160 MHz. In this case, the names Low and High are merely expressions used to divide the frequency range into 160 MHz + 80 MHz and do not necessarily relate to the actual frequency positions. In this case, the four spatial reuse fields corresponding to 80 MHz may each be set to a spatial reuse value indicating 20 MHz.

[0147] When the total bandwidth is 160 (or 80+80) MHz, each of the eight spatial reuse fields included in the trigger frame may correspond to 40 MHz (Lowest 40 MHz, Low 40 MHz, High 40 MHz, Highest 40 MHz), and the remaining four may be encoded to the same values ​​as the spatial reuse fields corresponding to each of the 40 MHz values.

[0148] Furthermore, if the trigger frame indicates a bandwidth of 80 MHz, each of the eight spatial reuse fields may correspond to 20 MHz (Lowest 20 MHz, Low 20 MHz, High 20 MHz, Highest 20 MHz), and the remaining four may be encoded to the same values ​​as the spatial reuse fields corresponding to each of the 20 MHz values.

[0149] Furthermore, if the trigger frame indicates a bandwidth of 40 MHz, each of the eight spatial reuse fields may correspond to 20 MHz (Low 20 MHz, High 20 MHz), and the remaining six may be encoded to the same values ​​as the spatial reuse fields corresponding to each of the 20 MHz values.

[0150] Furthermore, when the trigger frame indicates a 20MHz bandwidth, all eight space reuse fields can indicate space reuse values ​​corresponding to a primary of 20MHz.

[0151] In yet another embodiment of the present invention, the UL space reuse field may include four space reuse fields. In this case, each of the four space reuse fields may represent a space reuse value of 80 MHz for a 320 MHz bandwidth, and each may represent a space reuse value of 40 MHz for a 160 MHz bandwidth. Alternatively, each may represent a space reuse value of 20 MHz for an 80 MHz bandwidth.

[0152] When a 40MHz bandwidth is indicated by the trigger frame, two space reuse fields may correspond to either low or high 20MHz, and the remaining two may be encoded to the same values ​​as the space reuse fields corresponding to each 20MHz. Alternatively, when a 20MHz bandwidth is indicated by the trigger frame, all four space reuse fields can represent space reuse values ​​corresponding to a primary 20MHz.

[0153] Figure 12(b) shows an example of a puncturing mode field (8-bit or 16-bit). The puncturing mode field indicates the form of discontinuous channels relative to the PPDU through which the trigger frame is transmitted. That is, the puncturing mode may be indicated by the puncturing mode field for the bandwidth through which the trigger frame PPDU is transmitted. Here, the puncturing mode can indicate whether or not a portion of the total bandwidth is punctured and where the puncture occurs.

[0154] The puncturing mode field (or 16-bit bitmap) may be included in the additional information field rather than the (UL HE-SIG-A2) Reserved field of the common information field, and may contain two puncturing mode subfields. If two puncturing mode subfields are included, the discontinuous form of the channel on which the trigger frame contained in the 320 MHz or 240 MHz PPDU is transmitted may be divided into 160 MHz bandwidth segments, and the puncturing mode subfields may indicate whether or not puncturing occurs and the location of the puncture.

[0155] Figure 13 shows an example of the transmission of a trigger frame and a trigger frame-based TB PPDU according to one embodiment of the present invention.

[0156] Referring to Figure 13, when a trigger frame is transmitted containing multiple spatial reuse fields, each STA can transmit a response frame as a response to the trigger frame based on the multiple spatial reuse fields.

[0157] Specifically, STA1 to STA N, upon receiving a trigger frame from AP STA, can check the UL space reuse field included in the trigger frame's common information field, and then encode the values ​​of the four space reuse fields included in the UL space reuse field into space reuse fields 1 to 4, respectively, included in the U-SIG field of the TB PPDU, thereby generating the TB PPDU.

[0158] Figures 14A and 14B show yet another example of the transmission of a trigger frame and a trigger frame-based TB PPDU according to one embodiment of the present invention.

[0159] Referring to Figures 14A and 14B, when multiple spatial reuse fields are indicated using a trigger frame, TB PPDUs may be generated and transmitted / received using each of the different spatial reuse fields.

[0160] Specifically, multiple space reuse fields may be transmitted using a trigger frame. In this case, some of the multiple space reuse fields may be included in a common information field, and the remaining space reuse fields may be included in an additional information field.

[0161] In this case, a non-AP STA can generate a response frame using a spatial reuse field included in the common information field or additional information field, depending on whether the response frame to the RU location or trigger frame assigned to it is an HE TB PPDU or an EHT TB PPDU.

[0162] For example, a non-AP STA can generate an EHT TB PPDU using the space reuse field included in the additional information field and send the generated EHT TB PPDU as the response frame to the trigger frame if the location of the RU assigned to it is included in the secondary BW, or if the format associated with the trigger frame is in EHT format (for example, if the format of the user information field is in EHT format). However, if the location of the RU assigned to it is included in the primary BW, or if the format associated with the trigger frame is in HE format (for example, if the format of the user information field is in HE format), a non-AP STA can generate an HE TB PPDU using the space reuse field included in the common information field and send the generated HE TB PPDU as the response frame to the trigger frame.

[0163] For example, as shown in Figure 14A, among the non-AP STAs STA1 to STA N that have received a trigger frame, STA1 to STA n, whose RU position assigned by the trigger frame is located at Low 160MHz or Low 80MHz relative to the center frequency, select spatial reuse fields 1 to 4 corresponding to Low 180MHz or Low 80MHz from the eight spatial reuse fields 1 to 8 included in the trigger frame. STA1 to STA n can then encode the selected spatial reuse fields 1 to 4 into the U-SIG field of the TB PPDU, which is the response frame to the trigger frame.

[0164] In this case, if the TB PPDU generated by STA1 to STA n is an HE TB PPDU, then spatial reuse fields 1 to 4 may be spatial reuse fields included in the common information field of the trigger frame, and if the TB PPDU generated by STA1 to STA n is an EHT TB PPDU, then spatial reuse fields 1 to 4 may be spatial reuse fields included in the additional information field of the trigger frame.

[0165] As shown in Figure 14B, among the non-AP STAs STA1 to STA N that received the trigger frame, STA n+1 to STA N whose RU position assigned by the trigger frame is located at High 160MHz or High 80MHz relative to the center frequency select spatial reuse fields 5 to 8 from the eight spatial reuse fields 1 to 8 included in the trigger frame, corresponding to High 180MHz or High 80MHz. STA n+1 to STA N can then encode the selected spatial reuse fields 5 to 8 into spatial reuse fields 1 to 4, respectively, which are included in the U-SIG field of the TB PPDU, the response frame to the trigger frame.

[0166] In this case, if the TB PPDU generated by STA n+1 to STA N is HE TB PPDU, then spatial reuse fields 5 to 8 may be spatial reuse fields included in the common information field, and if the TB PPDU generated by STA1 to STA n is EHT TB PPDU, then spatial reuse fields 5 to 8 may be spatial reuse fields included in the additional information field.

[0167] In Figures 14A and 14B, a trigger frame can instruct the transmission of an HE TB PPDU and / or an EHT TB PPDU. At this time, at least one non-AP STA that receives the trigger frame can transmit an HE TB PPDU or an EHT TB PPDU in response to the trigger frame. The criteria for at least one non-AP STA to transmit a TB PPDU or an EHT TB PPDU may be based on the location of the assigned RU and / or the format associated with the trigger frame.

[0168] For example, if the RU location assigned by the trigger frame is a secondary BW that does not include the primary channel, or if the format associated with the trigger frame is in EHT format (for example, if the format of the user information field is in EHT format), an EHT TB PPDU can be generated and sent as a response to the trigger frame. However, if the RU location assigned by the trigger frame is a primary BW that includes the primary channel, or if the format associated with the trigger frame is in HE format (for example, if the format of the user information field is in HE format), an HE TB PPDU can be generated and sent as a response to the trigger frame.

[0169] Figure 15 is a flowchart showing an example of a method for selecting a space reuse field to generate a TB PPDU based on a trigger frame according to one embodiment of the present invention.

[0170] Referring to Figure 15, upon receiving a trigger frame, the STA can decode the trigger frame's preamble to identify the RU for uplink transmission, and based on the location of the identified RU, it can generate a TB PPDU using the spatial reuse fields of different trigger frames.

[0171] Specifically, the AP STA can send a trigger frame instructing the transmission of a TB PPDU, and the non-AP STA can receive the trigger frame from the AP STA and decode the received trigger frame (S15010).

[0172] Subsequently, the non-AP STA can generate a TB PPDU in order to send the TB PPDU indicated by the trigger frame as a response to the received trigger frame. In this case, the non-AP STA can use the information contained in the trigger frame to generate the TB PPDU.

[0173] Specifically, the non-AP STA decodes the trigger frame and, based on the RU assignment information field of the trigger frame, can identify the RU assigned to transmit its TB PPDU. The non-AP STA determines whether the location of the RU assigned to transmit the TB PPDU is in the high-frequency band (or the primary bandwidth including the primary channel) or the low-frequency band (or the second bandwidth not including the primary channel), relative to the center frequency of the entire bandwidth. If the assigned RU is located in the high-frequency band (or the primary bandwidth), the non-AP STA can encode the spatial reuse fields 1-4 included in the trigger frame into the spatial reuse fields 1-4 of the TB PPDU to generate the TB PPDU (S15020).

[0174] In this case, if the generated TB PPDU is an HE TB PPDU, the spatial reuse fields 1 to 4 of the trigger frame used to generate the TB PPDU may be spatial reuse fields included in the common information field of the trigger frame.

[0175] On the other hand, if the assigned RU is located in the lower frequency band (or Second BW), the non-AP STA can generate a TB PPDU by encoding the spatial reuse fields 5-8 included in the trigger frame into the spatial reuse fields 1-4 of the TB PPDU (S15030).

[0176] In this case, if the generated TB PPDU is an EHT TB PPDU, the spatial reuse fields 5-8 of the trigger frame used to generate the TB PPDU may be spatial reuse fields included in the additional information field of the trigger frame.

[0177] Figure 16 shows an example of spatial reuse operation based on the number of spatial reuse fields in a frequency band according to one embodiment of the present invention.

[0178] Referring to Figure 16, the number of space reuse fields relative to the bandwidth for PPDU transmission may affect the bandwidth region corresponding to the space reuse fields and the resulting OBSS space reuse.

[0179] Specifically, as shown in Figure 16, there are four OBSS1-4 with primary channels in a 320MHz bandwidth where a 320MHz TB PPDU is transmitted, and each of the four OBSS1-4 may experience interference of -65, -60, -58, and -50 dBm from the TB PPDU.

[0180] In this case, if only four space reuse fields are used, as shown in Figure 16(a), each of the four space reuse fields may be set to a value associated with the space reuse limit allowed at 80 MHz. On the other hand, if eight space reuse fields are used, as shown in Figure 16(b), each of the eight space reuse fields may be set to a value associated with the space reuse limit allowed at 40 MHz. In this case, the value set for a space reuse field may be set to the strictest value among the space reuse conditions applicable to the BW corresponding to the space reuse field. Therefore, one space reuse field corresponding to 80 MHz may be set to the lower of the two space reuse field values ​​corresponding to the two 40 MHz fields within 80 MHz (a value that restricts space reuse more).

[0181] As shown in Figure 16(a), where TB PPDU uses four spatial reuse values ​​for a 320MHz bandwidth, the spatial reuse values ​​for the bandwidth where each STA's primary channel is located in OBSS1-4 may be PSR_DISALLOW, -68dBm, -68dBm, and PSR_DISALLOW. In this case, the STAs will see that spatial reuse operation is not permitted for OBSS1 and OBSS4 and will not attempt channel access. Similarly, OBSS2 and OBSS3 will see that spatial reuse is permitted in the bandwidth where their primary channels are located, but since their interference is greater than the spatial reuse threshold, they will not be able to perform the backoff procedure for channel access.

[0182] On the other hand, as shown in Figure 16(b), where TB PPDU uses eight spatial reuse values ​​for a 320 MHz bandwidth, the spatial reuse values ​​for the bandwidth where each STA's primary channel is located in OBSS1-4 may be -72 dBm, -38 dBm, -41 dBm, and PSR_DISALLOW. In this case, OBSS2 and OBSS3 know that spatial reuse is permitted in the bandwidth where their primary channels are located, and since their interference (from the TB PPDU) is smaller than the spatial reuse threshold, they can perform a backoff procedure for channel access and then transmit.

[0183] Figure 17 shows an example of a trigger frame transmission method according to one embodiment of the present invention.

[0184] Referring to Figures 17(a) to (c), the form in which the trigger frame is sent may differ depending on the form and number of resources being sent.

[0185] Specifically, the trigger frame for 11be is a MAC frame, and may be transmitted over 20, 40, 80, 160, and 320 MHz depending on the BW of the PPDU to which the trigger frame is transmitted.

[0186] As shown in Figure 17(a), if some of the AP's operating bandwidth is occupied by a different device or OBSS (resulting in a BUSY status through CCA), the bandwidth of the PPDU from which the trigger frame is transmitted is restricted, and the trigger frame may be transmitted only on some of the operating bandwidths. This is a problem that occurs when a wideband channel access scheme follows a channel bonding scheme, and by utilizing the puncturing operation of the SU PPDU introduced in 11be, the trigger frame may be transmitted on a wider bandwidth using channels other than the one determined to be BUSY.

[0187] As shown in Figure 17(b), the trigger frame may be transmitted only in the remaining frequency bands, excluding channels where the CCA result is determined to be BUSY within the operating BW. In this case, the discontinuous form of the PPDU in which the trigger frame is transmitted may be signaled by the EHT PHY represented before the MAC frame containing the trigger frame. In this case, the discontinuous form of the PPDU in which the trigger frame is transmitted may be limited in accordance with the discontinuous form of the SU PPDU permitted by the EHT. The trigger frame may also be represented repeatedly in each 20 MHz PPDU and transmitted in a discontinuous form that is not represented only in specific channels (channels that are BUSY as a result of the CCA). In this case, the transmission form of the trigger frame may be similar to the U-SIG transmission method represented in a punctured PPDU.

[0188] As shown in Figure 17(c), the two trigger frames may be transmitted simultaneously. This is because the operational bandwidth (BW) of the STA that transmits the TB PPDU using the trigger frame may be included in only a portion of the bandwidth of the trigger frame transmitted by the AP. For example, the operational bandwidth of the STA that transmits the UL MU TB PPDU using a 320MHz trigger frame may be restricted to existing only within Low 160MHz or High 160MHz.

[0189] In this case, the two trigger frames may be transmitted by dividing the PPDU BW into two regions. The criterion for dividing the PPDU BW into two regions may be whether or not the BW of one region is 160MHz. That is, the PPDU BW may be divided so that the BW for one PPDU is 160MHz.

[0190] Furthermore, each trigger frame represented in the two regions may be represented in a discontinuous form within its respective region. In this case, the discontinuous forms applied to and represented by the two trigger frames may be limited in relation to the discontinuous forms of the SU PPDU permitted for the BW containing the two trigger frames. For example, in Figure 17(c), the discontinuous channel forms permitted for Trigger 1 may be limited to only the discontinuous channel forms permitted for the 160MHz SU PPDU.

[0191] Figure 18 shows an example of a TB PPDU including a puncturing mode according to one embodiment of the present invention.

[0192] When a puncturing mode is signaled by a trigger frame, the STA can include the information about the puncturing mode obtained from the trigger frame in its TB PPDU when configuring its TB PPDU. For example, as shown in Figure 18(a), if the puncturing mode field is included in the signaling field of the TB PPDU, the OBSS receiving the TB PPDU can recognize the discontinuity of the channel occupied by all TB PPDUs transmitted together with the TB PPDU, even with only the 20MHz TB PPDU signaling information obtained on its primary channel.

[0193] Furthermore, information regarding the puncturing mode may be used to more finely divide the frequency domain corresponding to the spatial reuse value. For example, if the puncturing mode information determines whether a portion of the BW domain corresponding to the spatial reuse field has been punctured, the BW corresponding to the spatial reuse field may be defined by the puncturing mode information to correspond only to the region other than the punctured bandwidth.

[0194] As shown in Figure 18(b), if the puncturing mode information in the puncturing mode field indicates that some BWs have been punctured, the information in the spatial reuse field corresponding to each BW may be applied only to the remaining BWs that have not been punctured.

[0195] <Dynamic RU TB PPDU>

[0196] UL MU (UL MU-MIMO or UL OFDMA) transmission using trigger frames and TB PPDUs is effective in reducing inter-STA contention by allowing multiple STAs to perform UL transmissions simultaneously, while also resolving the excessive overhead that can be induced by a single STA's Short PPDU (UL) transmission. However, unlike general UL PPDU transmissions, each STA must perform UL transmissions using RUs assigned by the AP via a trigger frame, rather than based on its own channel state (IDLE or BUSY).

[0197] The aforementioned problem of STA-side RU selection being restricted may stem from the fact that the AP-side TB PPDU reception procedure differs from the general reception procedure. To aid in understanding the AP's TB PPDU reception process, an example of the procedure in which an STA responds with a TB PPDU after receiving a trigger frame, and the operation of the AP receiving the TB PPDU transmitted by each STA, is shown in Figures 19 and 20 below.

[0198] Figure 19 shows an example of a resource unit allocation and TB PPDU response procedure using a trigger frame according to one embodiment of the present invention.

[0199] Referring to one embodiment in Figure 19, the AP can assign RUs (484 tone size RUs each) in the Low 40MHz and High 40MHz bands to STA1 and STA2, respectively, by transmitting a trigger frame using the IDLE-confirmed 80MHz band. In this case, the trigger frame can be understood as a trigger frame for UL OFDMA TB PPDU, since it assigns RUs located at different frequencies to the two STAs.

[0200] Upon receiving a trigger frame, STA1 and STA2 decode the received trigger frame and then confirm that the trigger frame contains two user information fields, and that one of the two user information fields is their own. At this point, each STA can recognize their own user information field based on whether or not the AID12 subfield of the user information field contains information related to their AID (for example, their AID LSB 12 bits).

[0201] STA1 can confirm that the RU assigned to it is a 484-tone RU located at Low 40MHz by the RU assignment subfield included in its user information field, and STA2 can recognize that the RU assigned to it is a 484-tone RU located at High 40MHz in the same manner as STA1.

[0202] Furthermore, the trigger frame may include not only information related to the RU (and SS (Spatial Stream)) assigned to each STA, but also various encoding parameters and PPDU length information that each STA must apply when generating a TB PPDU in response to the trigger frame. Each STA decodes the trigger frame to confirm the RU assigned to it, and then generates a TB PPDU by applying the encoding parameters indicated by the trigger frame. The generated TB PPDUs from each STA are simultaneously transmitted via UL, and the AP can receive a combined UL OFDMA PPDU from the TB PPDUs transmitted by each STA.

[0203] Considering the trigger frame transmission and the resulting UL OFDMA PPDU reception procedure briefly described above, the AP must separate the received OFDMA TB PPDU into the TB PPDUs of each STA in order to obtain the TB PPDUs transmitted by each STA. However, while the MAC of the AP, which is the entity that generated the trigger frame, knows the location and form of the RUs it assigned to each STA, the PHY of the AP, which is the entity that separates and decodes the OFDMA TB PPDU, does not know the configuration of the OFDMA TB PPDU it receives. Therefore, the conventional 11ax standard defines a procedure in which the MAC sublayer of the AP generates a trigger frame, requests transmission from the PHY layer, and then provides the PHY layer with the information necessary to receive the TB PPDU that is expected to be received as a response to the transmitted trigger frame.

[0204] 11ax issues a PHY-TRIGGER.request primitive after the MAC has requested transmission for the trigger frame, but before the STA receives the TB PPDU as a response to the trigger frame that requested the transmission of the TB PPDU. At this time, the PHY-TRIGGER.request is issued to request the PHY entity to set the parameters for receiving the TB PPDU.

[0205] The PHY-TRIGGER.request primitive provides the TRIGVECTOR parameter, which includes the bandwidth information (CH_BANDWIDTH) and L-SIG length information (UL_LENGTH) of the predicted TB PPDUs. At this time, the PHY performs preparatory work for receiving TB PPDUs, such as setting the Rx mode bandwidth using the bandwidth and length information of the TB PPDUs transmitted from the MAC.

[0206] Furthermore, the TRIGVECTOR parameter includes the AID12_LIST and RU_ALLOCATION_LIST of the STAs to which the RU is assigned by the trigger frame. The AID12_LIST and RU_ALLOCATION_LIST are used by the PHY to distinguish the subcarriers in which each STA's TB PPDU resides from the TB PPDUs (OFDMA UL PPDUs) received by multiple STAs, and as a result, the PHY can separate each user's TB PPDU from the TB PPDUs.

[0207] TRIGVECTOR includes encoding-related parameters applied to all TB PPDUs and MCS information used for each STA's TB PPDU. The PHY can use this encoding-related information to decode each STA's TB PPDU.

[0208] As mentioned above, considering that the MAC uses TRIGVECTOR to provide the PHY with information related to TB PPDUs that are expected to be received, the procedure for receiving TB PPDUs may differ from the procedure for receiving general PPDUs. In other words, unlike when receiving general PPDUs, the PHY does not obtain information for decoding the TB PPDUs being received from the preamble and SIG field of the TB PPDUs being received, but rather can wait for and decode the TB PPDUs based on the information provided by the MAC.

[0209] Figure 20 shows an example of a method for receiving TB PPDU based on a trigger frame according to one embodiment of the present invention.

[0210] Referring to Figure 20, the AP's PHY can receive a TRIGVECTOR transmitted from the MAC sublayer and predict TB PPDUs based on the information contained in the TRIGVECTOR.

[0211] Specifically, as shown in Figure 20, the MAC sublayer issues a PHY-TRIGGER.request primitive to the local PHY entity. At this time, the TRIGGER.request primitive may be issued after the MAC requests the PHY to send a trigger frame, but before the TB PPDU is received as a response to the trigger frame.

[0212] Upon receiving the TRIGGER.request primitive from the MAC, the PHY can determine from the CH_BANDWIDTH parameter of the TRIGVECTOR that the bandwidth of the expected received TB PPDUs is 80MHz. Subsequently, the PHY receives the 80MHz TB PPDUs and uses the AID12_LIST and RU_ALLOCATION_LIST parameters of the TRIGVECTOR received from the MAC to separate the TB PPDUs received via OFDMA as TB PPDUs for each user.

[0213] The process of separating TB PPDUs into TB PPDUs for each STA may be performed using the AID12_LIST and RU_ALLOCATION_LIST parameters among the TRIGVECTOR parameters. For example, as shown in Figure 20, the AID12_LIST parameter may include the 12 bits of the AID LSB for STA1 and STA2 as entries. This allows the PHY to recognize that the received TB PPDUs are a combination of the TB PPDUs of STA1 and STA2. Furthermore, by checking information about the form in which the TB PPDUs of STA1 and STA2 are represented from RU_ALLOCATION_LIST, the PHY can confirm that the RU of STA is a 484 tone RU located in the Low 40MHz band, and the RU of STA2 is a 484 tone RU located in the High 40MHz band. Therefore, after determining the location of the RUs to which TB PPDU1 and TB PPDU2 transmitted by STA1 and STA2 are transmitted, the PHY can attempt to decode each of them.

[0214] Considering the TB PPDU reception procedure described above, the reception of TB PPDUs can be completed using only the information transmitted from the receiver's MAC to the PHY. Therefore, the receiver can receive each STA's TB PPDU without having to decode the preamble and SIG field of each STA's transmitted TB PPDU.

[0215] For these reasons, the HE-SIG-A field of the 11ax TB PPDU may be configured to include information to assist the operation of the OBSS device (BSS color, TXOP, and four space reuse fields) instead of information necessary for receiving and decoding the TB PPDU.

[0216] Thus, unlike the general PPDU receiving procedure, TB PPDU reception may be performed based on information provided to the PHY by the MAC of the receiving device that generated the trigger frame, rather than obtaining information from the preamble and SIG field of the PPDU being received.

[0217] Therefore, if an STA that receives a trigger frame encodes the PPDU using a RU other than the one assigned by the trigger frame, or using a parameter value other than the parameter value indicated by the trigger frame, a device that receives TB PPDUs after transmitting the trigger frame will not be able to receive and process the TB PPDUs.

[0218] If a specific STA generates and transmits a TB PPDU using a RU other than the one assigned by the trigger frame, the PHY of the AP that sent the trigger frame may fail to separate the TB PPDU sent by that specific STA from the OFDMA TB PPDUs received from multiple STAs. Furthermore, if a specific STA encodes the PPDU using parameter values ​​other than those indicated by the trigger frame, the PHY of the AP that sent the trigger frame may be able to separate the TB PPDU from the received OFDMA TB PPDU, but decoding may fail. To prevent such TB PPDU reception failures, each STA that sends a TB PPDU as a response after receiving a trigger frame may be restricted to generating and transmitting the TB PPDU using only the RU assigned to it and the indicated parameter values.

[0219] Thus, restricting the STA to using only the RU and parameters assigned by the trigger frame when responding with a TB PPDU after receiving a trigger frame is essential to ensure that the AP can successfully receive and decode the TB PPDU responded by the STA. However, in situations where a hidden node of the AP exists on the STA side, the STA may not be able to efficiently utilize the RU assigned to it.

[0220] Figure 21 shows yet another example of a method for receiving TB PPDU based on a trigger frame according to one embodiment of the present invention.

[0221] Referring to Figure 21, when the AP's hidden node is on the STA side, the RU allocated by the AP's trigger frame cannot be used by the STA to transmit the TB PPDU.

[0222] Specifically, the AP can use a trigger frame to assign a 996-tone RU located in the Low 80MHz band to STA1, and a 242+(242)+484-tone RU located in the High 80MHz band to STA2. In this case, of the 160MHz band allocated to STA1 and STA2, the 20MHz band (242-tone RU) that is not allocated to either of the two STAs may be the band in which a subchannel identified as BUSY as a result of a CCA performed by the AP before sending the trigger frame exists.

[0223] The trigger frame transmitted by the AP should be received by the STA of the BSS operated by the AP. STA1 and STA2 can identify their own user information field from the AID field among at least one user information field included in the user information list field of the received trigger frame. At this time, STA1 can recognize from the RU assignment subfield present in its identified user information field that the RU assigned to it is a 996-tone RU in the Low 80MHz band, and STA2 can recognize, in the same manner as STA1, that the RU assigned to it is a 242+(242)+484-tone RU located in the High 80MHz band.

[0224] STA1 and STA2, having recognized their assigned RU via the trigger frame, must perform a CCA within the SIFS (Time Interval Between Received Trigger Frame and Responding with a TB PPDU). At this time, the CCA may be an ED-based CCA. The STA may perform an ED-based CCA only if the CS Required subfield, represented in the common information field of the received trigger frame, is 1. The ED-based CCA may include either or both of energy detection and virtual carrier sense (NAV) per 20MHz CCA sensitivity.

[0225] Furthermore, an STA that performs ED-based CCA after being assigned a RU by a trigger frame can either perform ED-based CCA on the entire BW region of the PPDU containing the trigger frame, or only on the subchannel containing the RU assigned to it by the trigger frame.

[0226] If, as a result of the CCA performed by the STA to which the RU was assigned by the trigger frame, it is determined that at least one of the 20MHz subchannels where the assigned RU resides is considered busy, then it is not possible to transmit a TB PPDU using the assigned RU.

[0227] STA1 and STA2 can each perform a Cancellation Correction (CCA) on the four 20MHz subchannels in the Low 80MHz band and the three 20MHz subchannels in the High 80MHz band that are assigned to them. As a result of performing the CCA on the subchannels in their assigned RU, both STAs can confirm that some of the subchannels in their assigned RU (one subchannel for STA1 and two subchannels for STA2) are busy. In this case, neither STA1 nor STA2 may be able to transmit a TB PPDU.

[0228] Thus, if an STA has a RU assigned by a trigger frame and there is a subchannel considered to be busy among the 20MHz subchannels where that RU is located, the STA's use of subchannels considered to be idle is also restricted. For this reason, the restriction that an STA assigned a RU by a trigger frame and transmitting a TB PPDU must utilize all of its assigned RU to transmit the TB PPDU can be a major cause of reduced efficiency in UL OFDMA transmissions performed by trigger frame-TB PPDU exchanges.

[0229] To address the limitations on the usability of STAs for RUs assigned by such trigger frames, the present invention proposes a procedure that allows STAs to adaptively change the RUs that transmit TB PPDUs based on the assigned RUs and the CCA results of the 20MHz subchannels present in the assigned RUs.

[0230] In this invention, the meaning of "20MHz subchannel present in the RU" may be used to indicate the 20MHz subchannel in which the subchannel corresponding to the RU is located. That is, there is one 20MHz subchannel in RUs of 26, 52, 106, and 242 tone sizes, and there are two and four 20MHz subchannels in RUs of 484 and 996 tone sizes, respectively. In this case, the final RU configuration determined by the STA based on the CCA results may be determined considering the already promised RU configuration. The method for determining the final RU configuration described above will be explained in detail by an embodiment described later. In short, one aspect of this invention is that an STA to which an RU has been assigned by a trigger frame can transmit a TB PPDU using all or part of the idle 20MHz subchannels present in the assigned RU based on the CCA results, without directly utilizing the assigned RU.

[0231] Figure 22 shows yet another example of a method for receiving TB PPDU based on a trigger frame according to one embodiment of the present invention.

[0232] Referring to Figure 22, a device that receives a trigger frame can use the trigger frame to transmit (respond to) a TB PPDU using only a portion of the allocated RUs.

[0233] Specifically, STA1 and STA2 can each transmit a TB PPDU using only the subchannels of their assigned RUs other than those considered BUSY based on the CCA results. Thus, the operation in which STA selectively changes the RU configuration used for TB PPDU generation and transmission based on the CCA results for the 20MHz subchannels within their assigned RUs can be implemented without any special performance issues. This is because, in the process of generating a TB PPDU after receiving a trigger frame, the operation of the STA shown in Figure 22 can be implemented by simply adding a step to update the RU configuration based on the CCA results, rather than using the RU configuration confirmed by the trigger frame as is.

[0234] As described above, the STA's operation can be easily implemented, but the AP may fail to decode the OFDMA PPDU (TB PPDUs) if the RU assigned to each STA using the trigger frame does not match the RU occupied by the TB PPDU transmitted by each STA, as shown in one embodiment in Figure 22.

[0235] Figure 23 shows yet another example of a method for receiving TB PPDU based on a trigger frame according to one embodiment of the present invention.

[0236] Referring to Figure 23, an AP may fail to receive UL OFDMA if the RU assigned by the trigger frame and the RU to which the TB PPDU, which is a response to the trigger frame, is sent have different RU configurations.

[0237] Considering the AP-side TB PPDU reception procedure explained in Figure 20, the AP's PHY can predict, based on the TRIGVECTOR received from the MAC, that STA1's TB PPDU1 will be received as a RU of 996 tones located in the Low 80MHz band, and STA2's TB PPDU2 will be received as a RU of 242+484 tones located in the High 80MHz band.

[0238] Therefore, when the AP begins receiving UL OFDMA PPDUs, it can predict that there is an 80MHz TB PPDU1 in the Low 80MHz band and attempt to decode the 80MHz PPDU, and predict that there is a TB PPDU2 at 20+(20)+40MHz in the High 80MHz band and attempt to decode the 20+(20)+40MHz PPDU. At this time, the TB PPDU1 and TB PPDU2 transmitted by STA1 and STA2, respectively, have different forms from the PPDUs that the AP attempts to decode. Consequently, the AP fails to decode the TB PPDUs transmitted as a response to the trigger frame.

[0239] As described above, in order to solve the problem that the AP cannot decode TB PPDUs that are UL transmitted with a different RU configuration at the discretion of each STA, rather than the RU configuration assigned using a trigger frame, a signaling or procedure is needed that allows the AP to recognize the form of the RU used by each STA. Therefore, the present invention provides a method that allows the AP to recognize the form (RU configuration) of the TB PPDU being received by the signaling field of the TB PPDU when it receives the TB PPDU, and a procedure for the AP to recognize and estimate the form of the TB PPDU transmitted by each STA by per 20MHz CCA.

[0240] To simplify the description of the invention described later, as mentioned above, when an STA assigned an RU by a trigger frame does not use the assigned RU as is, but instead uses only a portion of the RUs included in the assigned RU as a result of the CCA or for practical reasons to configure and UL transmit a TB PPDU, this can be called Dynamic TB PPDU configuration and UL transmission. As one embodiment of Dynamic TB PPDU configuration, Dynamic TB PPDU configuration means that an STA assigned an 80MHz RU uses 60(20+40)MHz RUs other than the 20MHz subchannel determined to be BUSY as a result of the CCA on the assigned 80MHz RU to configure a TB PPDU. In this case, the RUs used by each STA when configuring the Dynamic TB PPDU may be in a form that excludes some subchannels within the assigned RU that are determined to be IDLE, not only as a result of the CCA, but also due to the limitations of the M-RU (Multiple RU) configuration allowed by the standard, or practical constraints. Furthermore, in addition to the limitations or practical constraints of the CCA results and M-RU configuration, each STA can also configure a Dynamic TB PPDU by utilizing only a portion of the available RUs, rather than using all of them, if the amount of data it transmits is not large.

[0241] <Example of Trigger Frame Format for Dynamic TB PPDU>

[0242] After transmitting a trigger frame, the AP that receives Dynamic TB PPDU(s) as a response to the trigger frame, different from a conventional 11ax AP, must grasp the RU configuration in which the Dynamic TB PPDU transmitted by each STA is transmitted, without relying only on the RU information assigned to each STA using the trigger frame. For this purpose, each STA includes information regarding the RU in which the Dynamic TB PPDU configured by itself is transmitted in the preamble, and the AP can confirm the form of the Dynamic TB PPDU transmitted by each STA by receiving / decoding the preamble of the Dynamic TB PPDU transmitted by each STA. At this time, the AP can confirm the form of all RUs represented by the Dynamic TB PPDU only after decoding at least one subchannel represented by the preamble of the Dynamic TB PPDU transmitted by each STA.

[0243] Therefore, when a plurality of Dynamic TB PPDU are responded by a single trigger frame, the AP must decode the preambles of the plurality of Dynamic TB PPDU responded respectively, and the operation of decoding the plurality of preambles must be performed in parallel, so it has to be an operation that requires a high level of implementation complexity on the AP side.

[0244] If the AP does not have the ability to process the preamble of the Dynamic TB PPDU transmitted by each STA at once, it cannot decode the Dynamic TB PPDU in which the preamble is not properly processed among the Dynamic TB PPDU. For this reason, when the AP assigns an RU to the STA using the trigger frame, it is necessary to explicitly indicate whether or not it may respond to the STA with a Dynamic TB PPDU at the same time.

[0245] Furthermore, since Dynamic TB PPDU reception is performed by the PHY, the AP's MAC can, after constructing a trigger frame and requesting transmission from the PHY, transmit a DYNAMIC_RU_LIST to the PHY, along with the TRIGVECTOR parameter RU_ALLOCATION_LIST, indicating whether or not Dynamic TB PPDU reception is possible at each RU.

[0246] Figure 24 shows an example of a user information field in a trigger frame according to one embodiment of the present invention.

[0247] Referring to Figure 24, an STA to which a RU has been assigned by a trigger frame can determine whether or not to allow a Dynamic TB PPDU response based on the user-specific field of the trigger frame.

[0248] The reception of Dynamic TB PPDUs by an AP is an operation not supported by the previous 11ax standard and can increase the complexity of APs receiving UL OFDMA PPDUs. Therefore, APs can signal whether or not they are allowed to respond to their transmitted trigger frames with Dynamic TB PPDU responses, taking their own capabilities into consideration.

[0249] In one embodiment, the AP may use a specific field of the trigger frame to indicate whether or not to allow the STA to send a Dynamic TB PPDU in response to the TB PPDU after receiving the trigger frame.

[0250] Specifically, to indicate whether or not to allow each STA to respond with a Dynamic TB PPDU, the AP can use the user information field in the trigger frame, using a specific field included in the trigger frame.

[0251] As shown in Figure 24, the user information field of the trigger frame may consist of the following subfields: AID12, RU assignment, Dynamic TB PPDU Response, UL FED Coding Type, UL EHT-MCS, UL DCM, SS Allocation / RA-RU Information, UL Target RSSI, Reserved, and Trigger Dependent User Info.

[0252] The AID12 field indicates the 12-bit AID LSB of the STA whose RU has been assigned by the user information field and which must respond with a TB PPDU, and the RU assignment subfield indicates the size and location of the RU used by the STA which must respond with a TB PPDU. In this case, the RU assignment subfield may be interpreted in conjunction with the UL_BW contained in the common information field of the trigger frame.

[0253] Furthermore, the user information field of the 11be trigger frame is usually composed of subfields that have the same or similar functions as the trigger frame of 11ax, and the RU assignment subfield and SS assignment / RA-RU information subfield may be used to indicate the M-RU (Multiple RU) and the number of added antennas (16) that were added in 11be.

[0254] The Dynamic TB PPDU Response subfield, one of the subfields of the user information field, allows an STA, which has been assigned a RU by the user information field and is required to respond with a TB PPDU, to indicate whether or not to allow a Dynamic TB PPDU response that utilizes a portion of the assigned RU based on its CCA result. In one embodiment, when the Dynamic TB PPDU Resp subfield is set to 1, it indicates that a Dynamic TB PPDU response is allowed for the STA that received the user information field, and when the subfield is set to 0, it indicates that a Dynamic TB PPDU response is prohibited.

[0255] As another example, the AP may not need to separately signal to each STA whether a Dynamic TB PPDU response is allowed. At this time, each STA can recognize that a Dynamic TB PPDU response is allowed and operate only when it is assigned an SU-RU of 40 MHz or more by a trigger frame.

[0256] Alternatively, as another example, the AP can indicate to all STAs whether a Dynamic TB PPDU response is allowed by using a common information field (of the trigger frame) instead of the user information field of each STA. If a STA assigned an RU of 40 MHz or more has the ability to respond with a Dynamic TB PPDU when a Dynamic TB PPDU response is allowed by the common information field of the trigger frame, the STA can construct a Dynamic TB PPDU and respond to the trigger frame.

[0257] <Method for Determining Whether a Dynamic TB PPDU is Allowed>

[0258] In addition to the above-mentioned constraints related to the decoding ability of the AP, there may be cases where a Dynamic TB PPDU is not allowed. If the RU assigned to a specific STA using a trigger frame is smaller than 20 MHz (a 242-tone-sized RU) or is a 20 MHz RU, the STA assigned the RU may not be able to construct a Dynamic TB PPDU.

[0259] Assuming an STA is assigned a 20MHz RU, the STA would perform a CCA on the 20MHz subchannels within the 20MHz RU and determine that the entire 20MHz RU is either idle or busy. Therefore, an STA assigned a 20MHz RU has no basis for dynamically utilizing its assigned RU according to the CCA results. Furthermore, even if the CCA results for each RU within the 20MHz RU could be obtained, there is a problem in that the TB PPDU preamble must be composed in 20MHz units, meaning that preambles other than those for small RUs determined to be busy cannot be transmitted. Similarly, an STA assigned a RU smaller than 20MHz will also be limited in dynamic TB PPDU transmission for the same reasons as the STA assigned a 20MHz RU.

[0260] Furthermore, when an AP assigns the same RU to multiple STAs using a trigger frame, each STA must respond with a Dynamic TB PPDU using the same preamble and RU configuration. If multiple STAs assigned the same RU respond with Dynamic TB PPDUs using different RU configurations, the AP receiving these Dynamic TB PPDUs may not be able to distinguish the form of the Dynamic TB PPDU sent by each STA. Therefore, when an AP assigns a specific RU to multiple STAs, it can restrict each STA from responding with Dynamic TB PPDUs using different RU configurations by setting the Dynamic TB PPDU Resp. subfield in the user information field of each STA to 0.

[0261] Alternatively, each STA can perform a procedure to confirm whether the RU assigned to it is a MU (Multi-user) RU, which is also assigned to other TAs, when the RU is 40MHz or higher. In this case, each STA can respond with a Dynamic TB PPDU only when it has confirmed that the RU assigned to it is a SU (Single-user) RU, which is assigned only to it.

[0262] Furthermore, even if each STA is assigned different RUs, if the assigned different RUs are located within the same 80MHz RU boundary, the STA may be restricted from responding to Dynamic TB PPDU. This restriction may be based on the condition that different preambles cannot be represented within the 80MHz segment. If an AP uses a trigger frame to assign two 40MHz RUs located within the 80MHz segment to two STAs, each STA can respond by constructing different preambles when transmitting Dynamic TB PPDU. In this case, two different preambles may be represented within the 80MHz segment, which may be contrary to the principle defined in 11be. At this time, the Dynamic TB PPDU response restriction related to the preamble specification described above may be applied only to the embodiments of the present invention described later that relate to the preamble configuration of Dynamic TB PPDU.

[0263] Also, the operation of the STA that responds to or receives the aforementioned Dynamic TB PPDU may be an operation that is difficult to implement in an STA having a limited hardware configuration. Therefore, the AP and the STA may exchange information regarding whether to support the Dynamic TB PPDU response in the EHT-capability element and the RU configuration to be supported. At this time, when the Dynamic TB PPDU field of the EHT-capability element is indicated as 1, it may mean that the STA can configure and respond to the Dynamic TB PPDU.

[0264] <Trigger frame for Dynamic TB PPDU exchange, TB PPDU format example>

[0265] FIG. 25 shows an example of a method for transmitting a TB PPDU based on a trigger frame according to an embodiment of the present invention.

[0266] Referring to FIG. 25, the STA to which the RU is assigned by the trigger frame can respond with a Dynamic TB PPDU.

[0267] Specifically, the operation in which the AP assigns the RU using the trigger frame and the STAs STA1 and STA2 to which the RU is assigned by the trigger frame perform a Dynamic TB PPDU response assumes the same situation as the CCA situation of each STA shown in an embodiment of FIG. 22.

[0268] As shown in Figure 25, each STA can respond with information about the RU configuration it utilized using the U-SIG field of the Dynamic TB PPDU it responds to. Referring to Figure 25(a), STA1 can indicate that Dynamic TB PPDU1 is responded to by utilizing the 20+(20)+40MHz RUs, excluding the second 20MHz subchannel, of its assigned 80MHz RU, while STA2 can indicate that Dynamic TB PPDU2 is responded to by utilizing the 20MHz RU, which is the lowest frequency position of its assigned RU. In this case, if the AP decodes at least one preamble represented in the subchannel of the Dynamic TB PPDU transmitted by STA1 and STA2 respectively, the AP can recognize that STA1's Dynamic TB PPDU1 is received in the 20+(20)+40MHz RU located at Low 80MHz, and STA2's Dynamic TB PPDU2 is received in the Low 20MHz RU located at High 80MHz.

[0269] As mentioned above, the method by which each STA signals information about the RU configuration it used when constructing the Dynamic TB PPDU has a problem in that the representation of some RU configurations may be limited due to the limited length of the U-SIG field. For example, if an STA is assigned a 320MHz RU, and can freely use that 320MHz in 20MHz RU units to construct a Dynamic TB PPDU, then 16 bits must be allocated to accurately represent the configuration of the Dynamic TB PPDU that the STA with the 320MHz RU can construct. However, the U-SIG must include a version-independent field, a space reuse field for OBSS, and a puncturing mode field, and as mentioned above, it is impossible to allocate 16 bits to indicate the configuration of the Dynamic TB PPDU.

[0270] For these reasons, the size of the RU form - related fields available for use in indicating the form of the Dynamic TB PPDU may be limited and may have a configuration that excludes signaling for a specific RU combination. However, in 11be, considering the complexity and efficiency of implementation, the RU combinations (M - RU) that a single STA can utilize are limited. Regardless of the RU size assigned to the STA by the limited RU combinations, most Dynamic TB PPDU forms can be represented with only 4 bits.

[0271] FIG. 26 shows an example of the format of the U - SIG field of the TB PPDU according to an embodiment of the present invention. It can be assumed that the format of the U - SIG field of the TB PPDU shown in FIG. 26 is such that the U - SIG of the TB PPDU may be indicated by different values for each 80 - MHz segment.

[0272] Referring to FIG. 26, the U - SIG of the TB PPDU can include a version - independent field. The version - independent field may be a field that is commonly included in the next - generation WiFi PPDU regardless of the PHY protocol version and PPDU type, as described in an embodiment of FIG. 8 above.

[0273] Also, the spatial reuse 1, 2 fields represented in the U - SIG of the TB PPDU can indicate the spatial reuse values applied to the 80 - MHz segment in which the TB PPDU is transmitted.

[0274] Furthermore, the TB PPDU U-SIG may represent puncturing modes 1 and 2, and puncturing mode 1 may be a field that is simply copied / moved to represent the UL_Puncturing mode field value transmitted to each STA by the common information field of the trigger frame. The UL_Puncturing mode field may be a value of the puncturing mode that the AP predicts and indicates in the process of generating the trigger frame, in the process of the AP predicting the form of the UL OFDMA PPDU it will receive as a response to the trigger frame. In other words, the puncturing mode 1 field is not intended to provide information necessary for the AP to receive the Dynamic TB PPDU, but rather, similar to the space reuse field, may be information provided to assist the operation of other devices. Therefore, the puncturing mode 1 field may be a field that is shown with the same value in all (Dynamic) TB PPDUs responded to by the trigger frame.

[0275] On the other hand, the puncturing mode 2 field is a field that indicates the form of RU that an STA responding with a Dynamic TB PPDU utilized in constructing the Dynamic TB PPDU. Therefore, the puncturing mode 2 fields of (Dynamic) TB PPDU U-SIGs transmitted by different STAs (on different 80MHz segments) may have different values. An example of signaling utilizing the puncturing mode 2 field is illustrated in Figure 28 below.

[0276] The Segment location field provides information about which segment the TB PPDU containing the detected preamble is located in within the operating bandwidth (BW) of the AP receiving the TB PPDU, when the OBSS device detects the preamble in a specific segment. One example of signaling utilizing the Segment location field is illustrated in the example shown in Figure 28 below.

[0277] As mentioned above, the RU combinations that can be used in a Dynamic TB PPDU configuration by an STA to which RUs are assigned by a trigger frame may be limited to specific forms considering the complexity and efficiency aspects of implementation. For example, the RUs that can be assigned to a single STA using a trigger frame may be limited to Small RUs (RUs with 26, 52, 78, 106, and 132 tone sizes) and 20, 40, 60, 80, 120, and 160 MHz RUs (RUs with 242, 484, 996, 484+996, and 996×2 tone sizes, respectively). That is, 100 MHz RUs (RUs with 996+242 tone sizes) and 140 MHz RUs (RUs with 242+484+996 tone sizes) may be excluded because they do not have a greater gain than 80 MHz RUs and 120 MHz RUs, respectively, and thus increase the complexity of implementation. In this case, the types of RUs assigned to a single STA by the trigger frame of a 240 / 320MHz PPDU may also be restricted for the reasons described above. In this case, the restricted form of RU type may be Mandatory Multiple-RU.

[0278] According to one embodiment of the present invention, when a single STA utilizes a portion of the RUs assigned to it to configure a Dynamic TB PPDU, the configured Dynamic TB PPDU may be restricted to have a limited form, and the restricted form of the Dynamic TB PPDU can be signaled as a 4-bit bitmap.

[0279] Figure 27 shows an example of the configuration and signaling of a resource unit for transmitting TB PPDU according to one embodiment of the present invention.

[0280] Referring to Figure 27, the STA is assigned a 160MHz RU by a trigger frame, and the AP that generated and transmitted the trigger frame already knows the size and location of the RU assigned to the STA.

[0281] If, after the STA receives the trigger frame, it performs a CCA on the eight 20MHz subchannels included in the allocated 160MHz RU, and determines that one or both of the two subchannels located at the lowest frequency position are busy, then the Puncturing mode 2 of the Dynamic TB PPDU U-SIG can be set to 0111. In this case, even if only one of the two subchannels located at the lowest frequency position is busy, the STA must utilize the remaining 120MHz RU (RU with a tone size of 484+996) from the allocated 160MHz RU to configure the Dynamic TB PPDU.

[0282] In another embodiment, if the STA performs a CCA on the eight 20MHz subchannels included in the allocated 160MHz RU and, due to the RU configuration limitations described above, only the 80MHz RU can be utilized, the Puncturing mode2 field may be set to 0011 or 1100, and the STA can configure and UL transmit a Dynamic TB PPDU using only the 80MHz RU.

[0283] When considering the puncturing mode 2 (RU structure of Dynamic TB PPDU) signaling method utilizing the 4-bit size bitmap of the present invention described above, it can be seen that the minimum size of the RU that an STA can demonstrate by utilizing the puncturing mode 2 field is 1 / 4 of the RU size assigned to it. Therefore, as in this embodiment, if a 160MHz RU is assigned to the STA, and only one of the eight subchannels included in the RU is determined to be IDLE, the STA must abandon UL transmission utilizing Dynamic TB PPDU.

[0284] Figure 28 shows an example of a puncturing mode and segment position signaling using TB PPDU according to one embodiment of the present invention.

[0285] Referring to Figure 28, an STA may be assigned a RU by a trigger frame transmitted in a 160 MHz bandwidth, and both STAs can transmit a response to the trigger frame using a Dynamic TB PPDU of the U-SIG field, which includes the puncturing mode and segment position field.

[0286] In Figure 28, STA1 is assigned an 80MHz RU corresponding to segment 1 located at the lower frequency by the trigger frame, and STA2 is assigned a 20+(20)+40MHz RU included in segment 2 located at the higher frequency by the same trigger frame. STA1 and STA2, respectively, can utilize the 20+(20)+40MHz RU and 20MHz RU to configure and UL transmit Dynamic TB PPDU1 and 2, depending on the CCA results and RU configuration limitations.

[0287] In this case, the puncturing mode 1 field included in the U-SIG field of the Dynamic TB PPDU transmitted by STA1 and STA2 respectively will have the same value, but the puncturing mode 2 field and segment position field may be set to different values ​​for both Dynamic TB PPDUs.

[0288] The puncturing mode 1 field included in the Dynamic TB PPDU is a value indicated by the common information field of the trigger frame, and as mentioned above, it indicates the morphological information of the UL OFDMA PPDU that is expected to be responded to by the trigger frame. Therefore, the puncturing mode 1 field is shown with the same value in all TB PPDUs responded to by a single trigger frame.

[0289] As explained in the embodiment shown in Figure 27 above, the configuration of the puncturing mode 2 field allows each STA to signal with a different value to indicate the form of RU it is utilizing. Therefore, STA1 signals with the puncturing mode 2 field set to 1011 to indicate that its Dynamic TB PPDU1 is configured utilizing the 20+(20)+40MHz RU located in segment 1, and STA2 signals with the puncturing mode 2 field set to 1000 to indicate that its Dynamic TB PPDU2 is configured utilizing the 20MHz located at the lowest frequency in segment 2 where its assigned RU is located.

[0290] Furthermore, each STA can use a segment position field to indicate which segment in the BW (bandwidth) represents the TB PPDUs it transmits. The segment position field may be provided so that an STA that has detected the preamble of a particular TB PPDU can confirm information about the frequency domain in which the TB PPDUs transmitted with the TB PPDU are represented. In this case, the segment position field may be interpreted together with the BW field, which is another field included in the TB PPDU U-SIG. In one embodiment, if an STA confirms that the BW of the TB PPDU in the preamble it detected is 160 MHz and the segment position field is 00, it can confirm that the TB PPDU it detected, or the TB PPDUs responded with the detected TB PPDU, are transmitted over a 160 MHz BW, and that the position of the detected TB PPDU is at the lower frequency of 80 MHz.

[0291] One embodiment of the present invention considers a 2-bit example of the segment position field. Therefore, the four segments included in the maximum 320 MHz PPDU can be represented as 00, 01, 10, and 11 respectively from the segment located at the lower side frequency. If, as in one embodiment of FIG. 27, an RU is allocated to a specific STA over two segments, the specific STA can set the segment position fields included in the U-SIG field of the TB PPDU to different values (for example, 00, 01) according to each segment position.

[0292] As described above, a STA responding to a Dynamic TB PPDU has a procedure that it must configure the U-SIG field after making a determination on its own CCA result and RU configuration without using the value represented in the trigger frame requesting the Dynamic TB PPDU to configure the TB PPDU U-SIG.

[0293] Therefore, the operation of a STA responding to a Dynamic TB PPDU can be more complex compared to the operation of a STA responding to an 11ax TB PPDU, and a delay may occur in this process, making it difficult to respond to the TB PPDU within a defined time (SIFS after the trigger frame).

[0294] To solve such a problem, when an AP allows one or more STAs to respond to a Dynamic TB PPDU using a trigger frame, the AP can instruct that the response to the TB PPDU can be started at a time other than after SIFS. For example, when the AP indicates 1 in the Delayed response field by the common Info field of the trigger frame, the STA that has received the trigger frame can respond to the TB PPDU after PIFS instead of SIFS.

[0295] In Figure 28, Dynamic TB PPDU1 and 2, received as responses to a trigger frame, can have different U-SIG field configurations. For an AP to understand the form of the RU from which Dynamic TB PPDU1 and 2 are transmitted, it must decode at least one subchannel representing each of the two Dynamic TB PPDU1 and 2. However, the AP has the problem of not knowing which subchannels included in the RU it has assigned to each STA were excluded during the Dynamic TB PPDU response process. Therefore, the operation of decoding at least one subchannel representing each Dynamic TB PPDU is very difficult for the AP to implement. To mitigate this problem, it is necessary to have a subchannel that must be obligated to occupy when responding with a Dynamic TB PPDU already configured.

[0296] Figure 29 shows an example of setting up and using a subchannel for transmitting TB PPDH according to one embodiment of the present invention.

[0297] Referring to Figure 29, the AP uses a 320MHz trigger frame to assign one 80MHz RU located in each segment to STA1-4, and considers a situation where each STA is allowed to respond with a Dynamic TB PPDU. The AP can instruct each STA to occupy the subchannel that it should use when responding with a Dynamic TB PPDU. For example, Figure 29 shows a situation where the AP instructs STA1 to occupy the third subchannel and STA2-3 to occupy the first subchannel each. Each STA is obligated to occupy the subchannel instructed by the AP from among the four subchannels in the segment where its assigned RU is located and respond with a Dynamic TB PPDU. In the case of STA4, which is assigned an 80MHz RU located in segment 4, the CCA result determined that the first subchannel instructed by the AP (the subchannel with the lowest frequency in the segment) was BUSY. Therefore, it could not utilize the 60MHz RU other than the subchannel determined to be BUSY, and thus abandoned the transmission of the Dynamic TB PPDU.

[0298] Thus, when an STA responding to a Dynamic TB PPDU is instructed (by the AP) to always occupy a mandatory subchannel, or when a mandatory subchannel is already established, the AP can significantly reduce the burden of receiving at least one preamble for each Dynamic TB PPDU that is responded to simultaneously. In this case, the mandatory subchannel for the primary 80MHz segment may be fixed as the P20 channel. That is, when an STA assigned a RU that includes the primary 20MHz subchannel configures a Dynamic TB PPDU, Dynamic TB PPDU configurations that do not include the primary 20MHz may be restricted.

[0299] Therefore, depending on its capabilities, the AP can allow Dynamic TB PPDUs to be responded within the range it can support by setting the Mandatory subchannel as described above to reduce the burden on receiving the preamble, or by limiting the number of STAs that allow Dynamic TB PPDUs.

[0300] <Procedure Example for Receiving Dynamic TB PPDU>

[0301] The above-described Dynamic TB PPDU-related embodiments describe the format of the TB PPDU and the operations of the STAs (AP and non-AP) for the invention in which the AP obtains the information necessary for receiving the Dynamic TB PPDU by decoding the preambles of the TB PPDUs transmitted UL by each STA.

[0302] Another embodiment of the present invention described below provides a method for the AP to independently grasp the RU configuration of the Dynamic TB PPDUs transmitted by each STA. According to an embodiment of the present invention described below, the AP confirms the form represented by the TB PPDU received as a response to the trigger frame transmitted by itself based on the strength of the received signal, and compares it with the RU information assigned to each STA, thereby grasping the RU configuration of the Dynamic TB PPDUs transmitted UL by each STA.

[0303] To explain in more detail the method for receiving the Dynamic TB PPDU proposed by the present invention, since the AP has assigned RUs to each STA using the trigger frame, based on the information of the trigger frame generated by itself, it can calculate the reception time and BW of the TB PPDUs whose reception is predicted. Also, in the TB PPDUs whose reception is predicted, the position information represented by the TB PPDU transmitted UL by each STA is known in advance.

[0304] Thus, considering the situation where the AP knows the RU location of the TB PPDU transmitted by each STA, when the TB PPDU is received as a response to the trigger frame, the AP can attempt to detect signals in the subchannels where the TB PPDU is expected to be represented. This allows the AP to confirm whether the expected TB PPDU is represented or whether some subchannels are not being utilized. By confirming that the RU assigned to a specific STA is not being utilized, the AP can recognize that the unused RU has been excluded from the TB PPDU configuration. As a simple example, after the AP assigns an 80MHz RU to a specific STA using a trigger frame, it can predict that an 80MHz TB PPDU will be responded to the trigger frame. At this time, the AP can perform signal detection on the four subchannels within the 80MHz RU where the TB PPDU is expected to be responded to. If, as a result of the signal detection, signals are detected in only three subchannels, the remaining subchannel, rather than the three subchannels where signals were detected, can be confirmed to be the subchannel that the STA excluded during the process of configuring the Dynamic TB PPDU.

[0305] Thus, when an AP uses signal detection to independently determine the form of the TB PPDU responded to by each STA, an STA that responds with a Dynamic TB PPDU after receiving a trigger frame does not need to separately provide the AP with information related to the RU configuration of the Dynamic TB PPDU it transmits.

[0306] Another aspect of the effects obtained by utilizing the present invention is that the AP has the advantage of being able to interrupt additional processing of TB PPDUs that each STA has UL-transmitted and which are determined to be undecodeable, based on the signal detection results for the received TB PPDU.

[0307] Figure 30 shows an example of signal detection for TB PPDU as a response to a trigger frame according to one embodiment of the present invention.

[0308] Referring to Figure 30(a), the AP uses a 160MHz trigger frame to assign 80MHz RU for segment 1 and 20+(20)+40MHz RU for segment 2 to STA1 and STA2, respectively (allowing Dynamic TB PPDU responses), and upon receiving the trigger frame, STA1 and STA2 respond with Dynamic TB PPDU1 and PPDU2, respectively.

[0309] At this time, since the AP already knows that a TB PPDU will be received over a 160 MHz bandwidth after it transmits its trigger frame, it can attempt signal detection to determine the RU configuration in which the Dynamic TB PPDU will be received. The signal detection method performed by the AP at this time may be similar to that of a per 20 MHz CCA.

[0310] When an AP performs signal detection, it can utilize not only the BW of the TB PPDU that is expected to be received, but also information about the timing of the TB PPDU's reception. In the conventional 11ax standard, an STA that has been assigned a RU by a trigger frame must respond with a TB PPDU using the assigned RU after SIFS. Considering this time requirement for TB PPDU responses, the AP can predict that after transmitting the trigger frame, the TB PPDU will be received a specific time (e.g., SIFS (+ propagation delay)) after the end of transmission of the trigger frame.

[0311] Therefore, the AP can determine the range (frequency and time) of the signal detection operation by utilizing the predicted BW information and predicted reception timing information of the TB PPDUs that are expected to be received. At this time, the AP can attempt to detect the signal for a portion of the time interval in which the preamble of the TB PPDU is expected to be detected, based on the time information in which reception is expected.

[0312] Figure 30(b) shows an example of the detection results obtained when an AP performs signal detection for a TB PPDU. As shown in Figure 30(a), if STA1 uses 20+(20)+40MHz RU and STA2 uses 20MHz RU to respond with Dynamic TB PPDU1 and 2, then the signal detection results performed by the AP will show high signal levels in the subchannels used by each STA when constructing the Dynamic TB PPDU, and low signal levels in the subchannels not used for Dynamic TB PPDU transmission.

[0313] The AP can determine whether or not reception of the TB PPDU has begun in each subchannel by considering the signal strength detected in each subchannel. As a simple example, as shown in Figure 30(b), the AP can complete the signal detection described above based on whether or not the signal detected in each subchannel exceeds a specific threshold. In this case, the signal detection performed by the AP may be timed to coincide with the reception of the TB PPDU preamble, and unlike typical per 20MHz CCA, it may be performed using a PD (preamble detection) method or ED (energy detection), but using a different value from the ED threshold for general PIFS-based channel access.

[0314] As described above, after the AP identifies the subchannel from which TB PPDU reception began using signal detection, it can predict the RU configuration of the Dynamic TB PPDU transmitted by each STA based on the identified TB PPDU reception pattern.

[0315] In Figure 30, based on the signal detection results, the AP can determine that the TB PPDU is received as 1011 in segment 1 and 1000 in segment 2. At this time, since the 80MHz RU for segment 1 was allocated from STA1 using the trigger frame, the AP can recognize that the Dynamic TB PPDU is being responded to by utilizing 20+(20)+40MHz RU from the 80MHz RU allocated to STA1, excluding one subchannel. At this time, the determination of the Dynamic TB PPDU form of STA2 may be performed in the same way as the process for determining the Dynamic TB PPDU of STA1 described above.

[0316] The process of recognizing the Dynamic TB PPDU format described above will be briefly explained in relation to the operation performed by the AP's PHY. After receiving a request from the MAC to send a trigger frame, the AP's PHY may receive the RU_ALLOCATION_LIST and DYNAMIC_RU_LIST parameters via TRIGVECTOR. Subsequently, the PHY attempts to detect the TB PPDU signal at the time when the TB PPDU is expected to be responded to, and determines whether or not a TB PPDU has been received on each subchannel. At this time, the signal detection may be limited to only the subchannels where a Dynamic TB PPDU can be received based on the information in the DYNAMIC_RU_LIST parameter.

[0317] Based on the aforementioned signal detection results, the AP's PHY can modify the RU configuration of the STAs as confirmed by the RU_ALLOCATION_LIST parameter. As a result, even if a Dynamic TB PPDU is responded to using a RU with a different configuration than the one assigned by the MAC using the trigger frame, the PHY can properly isolate and decode the TB PPDU for each STA.

[0318] By utilizing the embodiment of the present invention described above, an AP can independently receive Dynamic TB PPDUs responded to by each STA without additional signaling using TB PPDU U-SIG. However, the signal detection method shown in Figure 30(b) above can be somewhat inaccurate, which can cause the AP to mistakenly determine which subchannel is receiving the TB PPDU. Therefore, in order to improve the accuracy of the signal detection described above, a signal detection method that adaptively adjusts and applies the threshold is necessary.

[0319] Figure 31 shows an example of applying different thresholds to regions where reception is expected in a signal detection process for a TB PPDU according to one embodiment of the present invention.

[0320] Referring to Figure 31, in the signal detection process to determine whether or not a TB PPDU has been received, different thresholds may be applied to regions where TB PPDUs of different STAs are predicted to be received.

[0321] In Figure 31, the AP can perform signal detection by applying different thresholds to RUs assigned to different STAs. It may be assumed that after the AP sends a trigger frame, it predicts that TB PPDU1 from STA1 will be responded to segment 1 and TB PPDU2 from STA2 will be responded to segment 2. In this case, the AP can apply a threshold of -x dBm to the four subchannels where TB PPDU1 is expected to be received to check whether TB PPDU1 is represented, and apply a threshold of -y dBm to the four subchannels where TB PPDU2 is expected to be received.

[0322] Thus, the reason for utilizing different thresholds to detect the TB PPDU of different STAs is that each STA that receives a trigger frame may be at a different distance from the AP, and the UL Target RSSI values ​​indicated by the AP using the User Info field of the trigger frame may be different from each other.

[0323] If AP instructs STA1 to satisfy -20dBm by indicating a UL Target RSSI of 90, then the signal received at -40dBm does not have to be the signal detected from the TB PPDU to which STA1 responded. On the other hand, if AP instructs STA2 to satisfy -110dBm by indicating a UL Target RSSI of 0, then the signal detection result using -40dBm as the threshold can ignore the TB PPDU signal to which STA2 responded.

[0324] Therefore, the AP can apply different thresholds to each STA when detecting the TB PPDU to which each STA responds, taking into account the Target RSSI value instructed to each STA. To this end, the AP's MAC must transmit RU(subchannel)_(target)RSSI_LIST to the TRIGVECTOR that transmits to the PHY.

[0325] According to the embodiment of the present invention described above, signal detection can be performed for TB PPDUs that are responded to using different Target RSSI values. However, if signal interference occurs in some of the subchannels used for signal detection by other devices, the signal detection results for those subchannels may appear to differ from the actual reception pattern of the TB PPDU.

[0326] In this way, to correct signal detection errors that may occur due to signals from other devices, the AP can determine whether or not a TB PPDU is represented based on a threshold during the signal detection process, and at the same time, it can further confirm whether or not a signal of a certain strength is received in the subchannel where each STA is expected to respond with a TB PPDU.

[0327] This is because the WiFi standard recommends that when a PPDU transmitted by an STA (AP, non-AP) has a bandwidth exceeding 20 MHz, the signal intensity emitted by the PPDU to each subchannel should be constant (for example, a maximum deviation of ±4 dB). Therefore, if any of the signals detected in each subchannel differ in signal intensity by a certain level or more from those detected in other subchannels, the signal detected from that subchannel can be determined to have been received from another device. In this case, the method of detecting a signal received from another device by comparing the signal intensity can be considered a signal detection error method that utilizes signal flatness.

[0328] Figure 32 shows an example of an error correction method for signal detection according to one embodiment of the present invention.

[0329] Referring to Figure 32, the AP performs signal detection to verify the RU configuration of the Dynamic TB PPDUs of STA1 and STA2, utilizing different thresholds for each STA's TB PPDUs for the subchannels where they are expected to be received.

[0330] At this time, a non-TB PPDU signal exceeding the threshold (-y dBm) set by the AP to detect the TB PPDU of STA2 may be detected in segment 2, where it is expected that the TB PPDU of STA2 will be received.

[0331] However, the AP's PHY can confirm that the signal detected in segment 2 has a different intensity than the signal detected in the first subchannel (the leftmost in the diagram) and the signals detected in the remaining second, third, and fourth subchannels. Based on this, the AP can determine that the signals detected in the first subchannel and the remaining subchannels are different signals. In this case, the AP can attempt to decode both the Dynamic TB PPDU transmitted by STA2's UL, either the 20MHz TB PPDU represented in the first subchannel or the 20+40MHz TB PPDU utilizing the remaining three subchannels.

[0332] Therefore, according to one embodiment of the present invention, the AP can utilize signal detection to understand the RU configuration of the Dynamic TB PPDU transmitted by each STA, and errors that may occur in the signal detection process can be resolved using an error detection method that uses adaptive threshold adjustment and the flatness of the WiFi signal.

[0333] Figure 33 is a flowchart showing an example of how a non-AP STA according to one embodiment of the present invention transmits a response frame to a trigger frame.

[0334] Referring to Figure 33, a non-AP STA can, upon receiving a trigger frame from the AP instructing it to send a TB PPDU, generate and respond with a TB PPDU of the type and format of the TB PPDU to be responded with.

[0335] Specifically, a non-AP STA can receive a trigger frame from the AP instructing it to send a TB PPDU (S33010). The trigger frame may include a common information field containing a first number of spatial reuse fields. The trigger frame may also include an additional information field containing a second number of spatial reuse fields, and whether or not the trigger frame contains the additional information field is determined based on the trigger frame's identification information.

[0336] In other words, a trigger frame may be identified by the identification information contained within the trigger frame as to whether or not it contains a second or more spatial reuse fields.

[0337] For example, as mentioned above, a trigger frame may include a first set of spatial reuse fields (spatial reuse fields 1-4) in its common information field, and depending on the identification information (for example, whether the value of a specific field in the common information field is '1' or the value of the AID in the additional information field is '2007'), the trigger frame may include an additional information field containing a second set of spatial reuse fields (spatial reuse fields 5-8).

[0338] The configuration of the trigger frame may be the same as the trigger format described in Figures 9 and 11. For example, the trigger frame may include at least one of a common information field, an additional information field, and a user information field, and the configuration of the additional information field and / or user information field may vary depending on the type and / or format of the trigger frame.

[0339] In this case, the user information field for each non-AP STA may be in EHT format or HE format, depending on the format of the TB PPDU indicated by the trigger frame.

[0340] In this case, the first multiple spatial reuse fields included in the common information field may be used to generate the HE TB PPDU if the RU's position for transmitting the TB PPDU, which is a response to the trigger frame, is in the higher frequency band (or primary BW), or if the TB PPDU is an HE TB PPDU. That is, the first multiple spatial reuse fields may be encoded into the spatial reuse fields of the TB PPDU.

[0341] The second or more spatial reuse fields for spatial reuse of the second bandwidth included in the additional information field may be used for generating the EHT TB PPDU if the RU's position for transmitting the TB PPDU, which is a response to the trigger frame, is in the lower frequency band (or primary or secondary bandwidth), or if the TB PPDU is an EHT TB PPDU. That is, the second or more spatial reuse fields may be encoded into the spatial reuse fields of the TB PPDU.

[0342] Alternatively, a first or second set of spatial reuse fields may be used to generate the TB PPDU, which is the response frame, in a format associated with the trigger frame (e.g., the format of the user information field).

[0343] For example, if the format associated with the trigger frame is HE format (for example, if the format of the user information field is HE format), the response frame, a TB PPDU, is generated as an HE TB PPDU using a first number of spatial reuse fields. However, if the format associated with the trigger frame is EHT format (for example, if the format of the user information field is EHT format), the response frame, a TB PPDU, is generated as an EHT TB PPDU using a second number of spatial reuse fields.

[0344] Subsequently, the non-AP STA can generate a response frame in response to the trigger frame, based on the information obtained from the first or second spatial reuse fields (S33020).

[0345] In other words, a non-AP STA can determine the format of the response frame to a trigger frame and generate a TB PPDU, which is the response frame, based on the determined format. In this case, the TB PPDU, which is the response frame, may be generated based on information obtained from a first plurality of spatial reuse fields or a second plurality of spatial reuse fields. Whether the response frame is generated based on the first plurality of spatial reuse fields or the second plurality of spatial reuse fields may be determined based on the format associated with the trigger frame. For example, if the format of the user information field of the trigger frame is HE format, the format of the TB PPDU is determined to be HE TB PPDU and may be generated based on the first plurality of spatial reuse fields. In other words, the response frame may be generated based on information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

[0346] The first or second set of spatial reuse fields for generating the TB PPDU may also be selected based on the location of the RU assigned for the transmission of the TB PPDU as indicated by the trigger frame. That is, if the RU is located in the upper frequency band (or primary band), the TB PPDU may be generated based on the first set of spatial reuse fields, and if the RU is located in the lower frequency band (or secondary band), the TB PPDU may be generated based on the second set of spatial reuse fields.

[0347] Subsequently, the non-AP STA may send a response frame in response to the trigger frame, generated based on information obtained from a first or second set of spatial reuse fields (S34030). Whether the response frame is generated based on a first or second set of spatial reuse fields may be determined based on the format associated with the trigger frame.

[0348] If the format associated with the trigger frame is the EHT (Extremely High Throughput) format, the response frame is generated based on the information obtained from the second set of spatial reuse fields.

[0349] Furthermore, if the format associated with the trigger frame is the HE (High Efficiency) format, the response frame is generated based on the information obtained from the first plurality of spatial reuse fields.

[0350] Furthermore, whether the response frame is generated based on information obtained from a first plurality of spatial reuse fields or based on information obtained from a second plurality of spatial reuse fields may be determined based on the position on the frequency axis of the resource unit to which the response frame is transmitted.

[0351] The trigger frame includes a bandwidth field, an additional bandwidth field, and a resource allocation field indicating the resource unit to which the response frame is transmitted. The trigger frame may further include at least one of the following: a puncturing mode field indicating whether puncturing is present in the bandwidth indicated by the bandwidth field and / or the additional bandwidth field, and where the puncturing is located.

[0352] Furthermore, the non-AP STA can recognize the resource unit to which the response frame is sent based on the resource allocation field included in the trigger frame, and can generate the response frame based on information obtained from a first or second set of space reuse fields, depending on the position of the resource unit to which the response frame is sent on the frequency axis.

[0353] When a response frame is generated based on a second or more spatial reuse fields, the response frame may be transmitted with a bandwidth indicated by the bandwidth field included in the common information field and the additional bandwidth field included in the additional information field.

[0354] The response frame includes multiple spatial reuse fields, each of which may be set based on information obtained from the corresponding first or second spatial reuse fields.

[0355] Whether or not a trigger frame includes the additional information field may be determined by whether or not the value of a specific subfield indicating whether or not the additional information field is included in the common information field, and / or whether the value of the identifier of the additional information field is set to a specific value.

[0356] Furthermore, the response frame may be transmitted in the form of a TB PPDU, as described above, and the TB PPDU may be transmitted in the form of an A(aggregated)-PPDU by combining with at least one TB PPDU transmitted from at least one other non-ATP STA whose transmission of a TB PPDU is instructed by the trigger frame. In this case, at least one TB PPDU is generated based on the first plurality of spatial reuse fields or the second plurality of spatial reuse fields, and the TB PPDU and the at least one TB PPDU are generated based on different spatial reuse fields.

[0357] Figure 34 is a flowchart showing an example of how an AP STA according to one embodiment of the present invention receives a response frame to a trigger frame.

[0358] Referring to Figure 34, an AP can send a trigger frame instructing the transmission of a TB PPDU, and can receive a TB PPDU in response from at least one non-AP STA. In this case, if there are two or more TB PPDUs transmitted from at least one non-AP STA, the TB PPDUs may be aggregated and transmitted in the form of an A-PPDU. Also, the TB PPDUs may be in different formats (e.g., HE TB PPDU, EHT TB PPDU, etc.).

[0359] Specifically, the AP can generate and transmit a trigger frame that instructs the transmission of a TB PPDU (S34010). The trigger frame may include a common information field containing a first number of spatial reuse fields. The trigger frame may also further include an additional information field containing a second number of spatial reuse fields, and whether or not the trigger frame contains the additional information field is determined based on the trigger frame's identification information.

[0360] In other words, a trigger frame may be identified by the identification information contained within the trigger frame as to whether or not it contains a second or more spatial reuse fields.

[0361] For example, as mentioned above, a trigger frame may contain a first set of spatial reuse fields (spatial reuse fields 1-4) in its common information field, and depending on the identification information (for example, whether the value of a specific field in the common information field is '1' or the value of the AID in the additional information field is '2007'), the trigger frame may also contain an additional information field containing a second set of spatial reuse fields (spatial reuse fields 5-8).

[0362] The configuration of the trigger frame may be the same as the trigger format described in Figures 9 and 11. For example, the trigger frame may include at least one of a common information field, an additional information field, and a user information field, and the configuration of the additional information field and / or user information field may vary depending on the type and / or format of the trigger frame.

[0363] In this case, the user information field for each non-AP STA may be in EHT format or HE format, depending on the format of the TB PPDU indicated by the trigger frame.

[0364] In this case, the first multiple spatial reuse fields included in the common information field may be used to generate the HE TB PPDU if the RU's position for transmitting the TB PPDU, which is a response to the trigger frame, is in the higher frequency band (or primary BW), or if the TB PPDU is an HE TB PPDU. That is, the first multiple spatial reuse fields may be encoded into the spatial reuse fields of the TB PPDU.

[0365] The second or more spatial reuse fields for spatial reuse of the second bandwidth included in the additional information field may be used for generating the EHT TB PPDU if the RU's position for transmitting the TB PPDU, which is a response to the trigger frame, is in the lower frequency band (or primary or secondary bandwidth), or if the TB PPDU is an EHT TB PPDU. That is, the second or more spatial reuse fields may be encoded into the spatial reuse fields of the TB PPDU.

[0366] Alternatively, a first or second set of spatial reuse fields may be used to generate the TB PPDU response frame, in a format associated with the trigger frame (e.g., the format of the user information field).

[0367] For example, if the format associated with the trigger frame is HE format (for example, if the format of the user information field is HE format), the response frame, a TB PPDU, is generated as an HE TB PPDU using a first number of spatial reuse fields. However, if the format associated with the trigger frame is EHT format (for example, if the format of the user information field is EHT format), the response frame, a TB PPDU, is generated as an EHT TB PPDU using a second number of spatial reuse fields.

[0368] Subsequently, the AP can receive at least one response frame (TB PPDU) from at least one non-AP STA as a response to the trigger frame (S34020). At this time, the TB PPDU may be generated based on information obtained from a first plurality of spatial reuse fields or a second plurality of spatial reuse fields.

[0369] The response frame, a TB PPDU, may be generated based on information obtained from a first or second set of spatial reuse fields. Whether the response frame is generated based on the first or second set of spatial reuse fields may be determined based on the format associated with the trigger frame. For example, if the format of the user information field in the trigger frame is HE format, the format of the TB PPDU is determined to be HE TB PPDU and may be generated based on the first set of spatial reuse fields. In other words, the response frame may be generated based on information obtained from the first or second set of spatial reuse fields.

[0370] The first or second set of spatial reuse fields for generating the TB PPDU may also be selected based on the location of the RU assigned for the transmission of the TB PPDU as indicated by the trigger frame. That is, if the RU is located in the upper frequency band (or primary band), the TB PPDU may be generated based on the first set of spatial reuse fields, and if the RU is located in the lower frequency band (or secondary band), the TB PPDU may be generated based on the second set of spatial reuse fields.

[0371] Whether the response frame is generated based on a first plurality of spatial reuse fields or a second plurality of spatial reuse fields may be determined based on the format associated with the trigger frame.

[0372] If the format associated with the trigger frame is the EHT (Extremely High Throughput) format, the response frame is generated based on the information obtained from the second set of spatial reuse fields.

[0373] Furthermore, if the format associated with the trigger frame is the HE (High Efficiency) format, the response frame is generated based on the information obtained from the first multiple spatial reuse fields. In other words, the response frame may be generated based on the information obtained from the first multiple spatial reuse fields or the second multiple spatial reuse fields.

[0374] The first or second set of spatial reuse fields for generating the TB PPDU may also be selected based on the location of the RU assigned for the transmission of the TB PPDU as indicated by the trigger frame. That is, if the RU is located in the upper frequency band (or primary band), the TB PPDU may be generated based on the first set of spatial reuse fields, and if the RU is located in the lower frequency band (or secondary band), the TB PPDU may be generated based on the second set of spatial reuse fields.

[0375] If the format associated with the trigger frame is the EHT (Extremely High Throughput) format, the response frame is generated based on the information obtained from the second set of spatial reuse fields.

[0376] Furthermore, if the format associated with the trigger frame is the HE (High Efficiency) format, the response frame is generated based on the information obtained from the first plurality of spatial reuse fields.

[0377] Furthermore, whether the response frame is generated based on information obtained from a first plurality of spatial reuse fields or based on information obtained from a second plurality of spatial reuse fields may be determined based on the position on the frequency axis of the resource unit to which the response frame is transmitted.

[0378] The trigger frame includes a bandwidth field, an additional bandwidth field, and a resource allocation field indicating the resource unit to which the response frame is transmitted. The trigger frame may further include at least one of the following: a puncturing mode field indicating whether puncturing is present in the bandwidth indicated by the bandwidth field and / or the additional bandwidth field, and where the puncturing is located.

[0379] Furthermore, the non-AP STA can recognize the resource unit to which the response frame is sent based on the resource allocation field included in the trigger frame, and can generate the response frame based on information obtained from a first or second set of spatial reuse fields depending on the position of the resource unit to which the response frame is sent on the frequency axis.

[0380] When a response frame is generated based on a second or more spatial reuse fields, the response frame may be transmitted with a bandwidth indicated by the bandwidth field included in the common information field and the additional bandwidth field included in the additional information field.

[0381] The response frame includes multiple spatial reuse fields, each of which may be set based on information obtained from the corresponding first or second spatial reuse fields.

[0382] Whether or not a trigger frame includes the additional information field may be determined by whether or not the value of a specific subfield indicating whether or not the common information field includes the additional information field, and / or the value of the identifier of the additional information field, is set to a specific value.

[0383] Furthermore, the response frame may be transmitted in the form of a TB PPDU, as described above, and the TB PPDU may be received in the form of an A(aggregated)-PPDU, combined with at least one TB PPDU transmitted from at least one other non-ATP STA whose transmission of the TB PPDU is instructed by the trigger frame. In this case, at least one TB PPDU is generated based on the first plurality of spatial reuse fields or the second plurality of spatial reuse fields, and the TB PPDU and the at least one TB PPDU are generated based on different spatial reuse fields.

[0384] The above description of the present invention is illustrative, and a person with ordinary skill in the art to which the invention pertains will understand that it can be easily modified into other specific forms without altering the technical idea or essential features of the invention. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0385] The scope of the present invention is indicated more by the claims described below than by the detailed description above, and any modified or altered forms derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included within the scope of the present invention.

Claims

1. A terminal of a wireless communication system, Communication module and A processor configured to control the aforementioned communication module Includes, The aforementioned processor, Receiving a trigger frame containing a Common Information (CI) field from an access point (AP), The aforementioned common information field includes a first plurality of spatial reuse (SR) fields, Depending on whether the trigger frame is of the ultra-high-speed (EHT) type or high-efficiency (HE) type, the trigger frame may or may not include a second plurality of spatial reuse (SR) fields. That thing, In response to the trigger frame, transmit a trigger-based physical layer protocol data unit (TB PPDU), The TB PPDU is generated using the first plurality of spatial reuse fields or the second plurality of spatial reuse fields, based on whether the type of the trigger frame is the EHT type or the HE type. thing and A terminal configured to perform the following actions.

2. The terminal according to claim 1, wherein when the type of the trigger frame is the EHT type, the TB PPDU is generated using the second plurality of spatial reuse fields.

3. The terminal according to claim 1, wherein when the type of the trigger frame is the HE type, the TB PPDU is generated using the first plurality of spatial reuse fields.

4. The terminal according to claim 1, wherein the trigger frame includes the second plurality of spatial reuse fields when the type of the trigger frame is the EHT type.

5. The terminal according to claim 1, wherein the trigger frame does not include the second plurality of spatial reuse fields when the type of the trigger frame is the HE type.

6. The terminal according to claim 1, wherein the location of the frequency band to which a resource unit for transmitting the TB PPDU is allocated differs depending on whether the TB PPDU is generated using the first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

7. The terminal according to claim 6, wherein when the TB PPDU is generated using the second plurality of spatial reuse fields, the resource unit for transmitting the TB PPDU is allocated within a secondary 160 MHz channel.

8. The terminal according to claim 1, further comprising identification information used to indicate whether the type of the trigger frame is the EHT type or the HE type.

9. The terminal according to claim 1, wherein when the type of the trigger frame is the EHT type, the TB PPDU is generated based on a bandwidth indicated by a combination of i) a bandwidth field included in the common information (CI) field and ii) an additional bandwidth field included in the trigger frame.

10. A method for transmitting data by a terminal in a wireless communication system, The step of receiving a trigger frame containing a Common Information (CI) field from an access point (AP), The aforementioned common information field includes a first plurality of spatial reuse (SR) fields, Depending on whether the trigger frame is of the ultra-high-speed (EHT) type or high-efficiency (HE) type, the trigger frame may or may not include a second plurality of spatial reuse (SR) fields. Steps and The step of transmitting a trigger-based physical layer protocol data unit (TB PPDU) in response to the trigger frame, The TB PPDU is generated using the first plurality of spatial reuse fields or the second plurality of spatial reuse fields, based on whether the type of the trigger frame is the EHT type or the HE type. Steps and A method that includes [a certain feature].

11. The method according to claim 10, wherein when the type of the trigger frame is the EHT type, the TB PPDU is generated using the second plurality of spatial reuse fields.

12. The method according to claim 10, wherein when the type of the trigger frame is the HE type, the TB PPDU is generated using the first plurality of spatial reuse fields.

13. The method according to claim 10, wherein the trigger frame includes the second plurality of spatial reuse fields when the type of the trigger frame is the EHT type.

14. The method according to claim 10, wherein when the type of the trigger frame is the HE type, the trigger frame does not include the second plurality of spatial reuse fields.

15. The method according to claim 10, wherein the location of the frequency band to which a resource unit for transmitting the TB PPDU is allocated differs depending on whether the TB PPDU is generated using the first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

16. The method according to claim 15, wherein when the TB PPDU is generated using the second plurality of spatial reuse fields, the resource unit for transmitting the TB PPDU is allocated within a secondary 160 MHz channel.

17. The method according to claim 10, further comprising identification information used to indicate whether the type of the trigger frame is the EHT type or the HE type.

18. The method according to claim 10, wherein when the type of the trigger frame is of type EHT, the TB PPDU is generated based on a bandwidth indicated by a combination of i) a bandwidth field included in the common information (CI) field and ii) an additional bandwidth field included in the trigger frame.

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