Method for transmitting / receiving data in radio communication system and radio communication terminal

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

[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 expanded, 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 IEEE (Institute of Electronics Engineers) 802.11 supported the initial wireless LAN technology using the 2.4 GHz frequency, various technology standards have been put into practical use or are under development. First, IEEE 802.11b uses the frequency in the 2.4 GHz band and supports a communication speed of up to 11 Mbps. IEEE 802.11a, which was commercialized after IEEE 802.11b, uses the frequency in the 5 GHz band instead of the 2.4 GHz band, reducing the impact on interference compared to the rather congested 2.4 GHz band frequency, and uses OFDM technology to improve the communication speed up to 54 Mbps. However, IEEE 802.11a has the disadvantage of a shorter communication distance compared to IEEE 802.11b. And IEEE 802.11g uses the same 2.4 GHz band frequency as IEEE 802.11b to achieve a maximum communication speed of 54 Mbps, satisfies backward compatibility, and has received considerable attention, but it is also superior to IEEE 802.11a in terms of communication distance.

[0004] And, as a technical standard established to overcome the limitations regarding communication speed, which have been pointed out as vulnerabilities in wireless LANs, there is IEEE 802.11n. The purpose of IEEE 802.11n is to increase the speed and reliability of the network and expand the operating distance of the wireless network. Specifically, IEEE 802.11n supports a high throughput (HT) with a data processing speed of up to 540 Mbps or more, and is based on the MIMO (Multiple Inputs and Multiple Outputs) technology that uses multiple antennas at both the transmitting and receiving ends to minimize transmission errors and optimize the data speed. Also, this standard uses a coding method that transmits multiple copies of overlapping transcripts to increase the reliability of the data.

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

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

[0007] In addition, in order to support new multimedia applications such as high-quality videos and real-time games, a new Wi-Fi standard for increasing the maximum transmission speed has been started to be developed. In the 7th generation Wi-Fi standard, IEEE 802.11be (Extremely High Throughput, EHT), the standard development is in progress with the goal of supporting a maximum transmission rate of 30 Gbps by means of a wider bandwidth, increased spatial streams, and multi-AP cooperation in the 2.4 / 5 / 6 GHz bands.

Summary of the Invention

Problems to be Solved by the Invention

[0008] As described above, an object of the present invention is to provide an ultra-high-speed Wi-Fi service for new multimedia applications.

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

[0010] Another object of the present invention is to provide a method and apparatus for generating an HE (High Efficiency) PPDU or an EHT (Extremely High Throughput) PPDU based on different information included in a trigger frame transmitted from an AP (Access Point).

[0011] The technical problems to be achieved in this specification are not limited to the technical problems mentioned above, and other technical problems 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.

Means for Solving the Problems

[0012] In a wireless communication system, a terminal for transmitting 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 for controlling the communication module, where the processor receives a trigger frame from an AP (Access Point), the trigger frame includes a common information field including a first plurality of spatial reuse fields, and it is identified whether an additional information field including a second plurality of spatial reuse fields is included based on the identification information of the trigger frame, and as a response to the trigger frame, a response frame generated based on information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields is transmitted, and whether 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.

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

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

[0015] Also, 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 where the response frame is transmitted.

[0016] In the present invention, the trigger frame further includes a bandwidth field, an additional bandwidth field, and a resource allocation field for indicating a resource unit to which the response frame is transmitted.

[0017] 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 spatial reuse fields or the second plurality of spatial reuse fields according to a position on the frequency axis of the resource unit to which the response frame is transmitted.

[0018] In the present invention, the trigger frame further includes a puncturing mode field for indicating the presence or absence of puncturing and a punctured position in a bandwidth indicated by the bandwidth field and / or the additional bandwidth field.

[0019] In the present invention, when the response frame is generated based on the second plurality of spatial 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] In the present invention, the response frame includes a plurality of spatial reuse fields, and each of the plurality of spatial reuse fields is set based on information obtained from each of the corresponding first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

[0021] In the present invention, whether or not the trigger frame includes the additional information field is recognized by whether or not the value of a specific sub-field indicating whether or not the common information field includes the additional information field and / or whether or not the value of the identifier of the additional information field is set to a specific value.

[0022] In the present invention, the response frame is a TB PPDU (Trigger based Physical layer Protocol Data Unit), and the TB PPDU is transmitted in the form of an A (aggregated)-PPDU by aggregating at least one TB PPDU transmitted from at least one other terminal whose transmission of the TB PPDU is instructed by the trigger frame. 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 from each other.

[0023] The present invention also provides a method including: receiving, from an AP (Access Point), a trigger frame, where the trigger frame includes a common information field including a first plurality of spatial reuse fields, and based on the identification information of the trigger frame, identifying whether or not to include an additional information field including a second plurality of spatial reuse fields; and transmitting, as a response to the trigger frame, a response frame generated based on information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields, where whether 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.

Advantages of the Invention

[0024] According to an embodiment of the present invention, by using a trigger frame to include information for generating TB PPDUs in different formats in different fields respectively and transmitting them, 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, since the trigger frame is transmitted 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 having ordinary knowledge in the technical field to which the present invention pertains from the following description.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0030] The terms used in this specification are selected as generally widely used common terms as much as possible in consideration of the functions in the present invention, but this may vary depending on the intentions, conventions, or the emergence of new technologies of those skilled in the relevant technical field. Also, in certain cases, there are terms arbitrarily selected by the applicant, and in such cases, the meaning thereof is described in the explanatory part of the corresponding invention. Therefore, it is clarified that the terms used in this specification should not be merely the names of the terms, but should be interpreted based on the substantial meaning that the terms have and the content throughout this specification.

[0031] Throughout the specification, if a certain configuration is "connected" to another configuration, this includes not only the case where it is "directly connected", but also the case where it is "electrically connected" with other components interposed therebetween. Also, if a certain component "includes" a specific component, this means that it may further include other components rather than excluding other components, unless otherwise stated to the contrary. In addition, the limiting terms "above" or "below" based on a specific critical value may be appropriately replaced by "exceeding" or "less than" respectively according to the embodiments. Hereinafter, in the present invention, a field and a subfield may be used in the same meaning.

[0032] FIG. 1 is a diagram showing a wireless LAN system according to an embodiment of the present invention.

[0033] The wireless LAN system includes one or more Basic Service Sets (BSSs), and 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 FIG. 1 shows an infrastructure BSS among them.

[0034] As shown in FIG. 1, the infrastructure BSSs BSS1 and BSS2 include one or more stations STA1, STA2, STA3, STA4, STA5, access points AP-1 and AP-2 which are stations providing a Distribution Service, and a Distribution System (DS) that connects the plurality of access points AP-1 and AP-2.

[0035] A station (STA) is any device that includes a Medium Access Control (MAC) and a Physical Layer interface for a wireless medium in accordance with the IEEE 802.11 standard. In a broad sense, it includes not only non-access point non-AP stations but also all access points AP. Also, in this specification, the term "terminal" is used to refer to either a non-AP or an AP, or both. A station for wireless communication includes a processor and a communication unit, and in some embodiments, further includes a user interface unit, a display unit, etc. The processor generates frames to be transmitted via a wireless network, or processes frames received via the wireless network, and performs various other processes for controlling the station. And the communication unit is functionally connected to the processor and transmits and receives frames via the wireless network for the station. In the present invention, the term "terminal" is used to include a user equipment (UE).

[0036] An access point (AP) is an entity that provides a connection to a distribution system DS via a wireless medium for stations associated with itself. In an infrastructure BSS, in principle, communication between non-AP stations is performed via the AP, but direct communication is possible between non-AP stations if a direct link is set up. On the other hand, in the present invention, an AP is used as a concept including a PCP (Personal BSS Coordination Point), but in a broad sense, it includes concepts such as a centralized controller, a base station (BS), a Node B, a BTS (Base Transceiver System), or a site controller. In the present invention, an AP is also referred to as a base wireless communication terminal, and the base wireless communication terminal is used as a term that includes, in a broad sense, an AP, a base station, an eNB (eNodeB), and a transmission point TP. Moreover, the base wireless communication terminal includes various forms of wireless communication terminals that allocate communication medium resources and perform scheduling in communication with a plurality of wireless communication terminals.

[0037] A plurality of infrastructure BSSs are connected to each other via a distribution system DS. At this time, a plurality of BSSs connected via the distribution system are called an extended service set (ESS).

[0038] FIG. 2 is a diagram showing an independent BSS which is a wireless LAN system according to another embodiment of the present invention. In the embodiment of FIG. 2, parts that are the same as or corresponding to the embodiment of FIG. 1 will not be described redundantly.

[0039] Since the BSS3 shown in FIG. 2 is an independent BSS that does not include an AP, all stations (STA6, STA7) are not connected to the AP. An independent BSS does not allow connection to the distribution system and forms a self - contained network. In an independent BSS, each station (STA6, STA7) is directly connected to each other.

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

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

[0042] Next, the user interface 140 includes various forms of input / output means provided in the station 100. That is, the user interface unit 140 receives user input using various input means, and the processor 110 controls the station 100 based on the received user input. Also, the user interface unit 140 performs output based on the instructions of the processor 110 using various output means.

[0043] Next, the display unit 150 outputs an image on the display screen. The display unit 150 outputs various display objects such as content performed by the processor 110 or a user interface based on the control instructions of the processor 110. Also, the memory 160 stores control programs used in the station 100 and various data thereby. Such control programs include connection programs necessary for the station 100 to connect to an AP or an external station.

[0044] The processor 110 of the present invention performs various instructions or programs and processes the data inside the station 100. Also, the processor 110 controls each unit of the station 100 described above and controls the transmission and reception of data between the units. According to an embodiment of the present invention, the processor 110 executes a program for connection with the AP stored in the memory 160 and receives a communication setting message transmitted by the AP. Also, the processor 110 reads information regarding the priority conditions of the station 100 included in the communication setting message and requests a connection regarding the AP based on the information regarding the priority conditions of the station 100. The processor 110 of the present invention may refer to the main control unit of the station 100, or may refer to a control unit for individually controlling some configurations of the station 100, for example, the communication unit 120, etc. according to an embodiment. That is, the processor 110 may be a modem, or a modulator and / or demodulator that modulates and demodulates the radio signals transmitted and received from the communication unit 120. The processor 110 controls various operations of the radio signal transmission and reception of the station 100 according to an embodiment of the present invention. Detailed embodiments thereof will be described later.

[0045] The station 100 shown in FIG. 3 is a block diagram according to an embodiment of the present invention, and the separately shown blocks logically distinguish the elements of the device. Therefore, the above-described elements of the device may be attached to one chip or a plurality of chips according to the design of the device. For example, the processor 110 and the communication unit 120 may be integrated and implemented on one chip, or may be implemented on separate chips. Also, in an embodiment of the present invention, some configurations of the station 100, for example, the user interface unit 140 and the display unit 150, etc. may be selectively provided in the station 100.

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

[0047] Referring to FIG. 4, the AP 200 according to the present invention includes a communication unit 220 for operating a BSS in at least one frequency band. As described above in the embodiment of FIG. 3, the communication unit 220 of the AP 200 can also include a plurality of communication modules using different frequency bands. That is, the AP 200 according to the embodiment of the present invention can include two or more communication modules using different frequency bands, for example, any of 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz. Preferably, the AP 200 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 perform wireless communication with a station based on the wireless LAN standard of the frequency band supported by the communication module. The communication unit 220 can operate only one communication module at a time or operate a plurality of communication modules simultaneously according to the performance and requirements of the AP 200. In the embodiment of the present invention, the communication unit 220 can represent an RF (Radio Frequency) communication module that processes RF (Radio Frequency) signals.

[0048] Next, the memory 260 stores the control program used in the AP200 and various data thereby. Such a control program includes a connection program for managing the connection of the stations. Further, the processor 210 controls each unit of the AP200 and controls the transmission and reception of data between the units. According to an embodiment of the present invention, the processor 210 executes a program for connection to the station stored in the memory 260 and transmits a communication setting message for one or more stations. At this time, the communication setting message includes information regarding the connection priority condition of each station. Further, the processor 210 performs connection setting in response to a connection request from the station. According to one embodiment, the processor 210 is a modem or a modulation / demodulation unit that modulates and demodulates a radio signal transmitted and received from the communication unit 220. The processor 210 controls various operations of radio signal transmission and reception of the AP200 according to an embodiment of the present invention. Detailed embodiments thereof will be described later.

[0049] FIG. 5 is a diagram schematically showing a process in which a STA sets a link with an AP.

[0050] Referring to FIG. 5, the link between the STA100 and the AP200 is set through three major steps of scanning, authentication, and association. First, the scanning step is a step in which the STA100 obtains connection information of the BSS operated by the AP200. As a method for performing scanning, there are a passive scanning method in which information is obtained by utilizing only the beacon message S101 periodically transmitted by the AP200, and an active scanning method in which the STA100 transmits a probe request to the AP, receives a probe response from the AP, and obtains connection information.

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

[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 FIG. 5, the server 300 is a server that processes 802.1X-based authentication with the STA100, and may be physically connected to the AP200 or exist as a separate server.

[0053] FIG. 6 is a diagram showing 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 in an occupied state (busy) by performing carrier sensing before transmitting data. If a wireless signal with a certain intensity or higher is sensed, the corresponding channel is determined to be in an occupied state, and the terminal delays access to the corresponding channel. Such a process is called Clear Channel Assessment (CCA), and the level for determining the presence or absence of sensing of the corresponding signal is called the CCA threshold. If a wireless signal equal to or higher than the CCA threshold received by the terminal has the terminal as the recipient, the terminal processes the received wireless signal. On the other hand, if no wireless signal is sensed from the corresponding channel or a wireless signal with an intensity lower than the CCA threshold is sensed, the channel is determined to be in an idle state.

[0055] If the channel is determined to be in an idle state, each terminal having data to transmit performs a backoff procedure after a time of IFS (Inter Frame Space) according to the situation of each terminal, for example, AIFS (Arbitration IFS), PIFS (PCF IFS), etc. According to an embodiment, the AIFS is used as a configuration to replace the conventional DIFS (DCF IFS). Each terminal waits while reducing the slot time by the random number determined for the corresponding terminal during the interval of the idle state of the channel, and the terminal that has exhausted all the slot times attempts access to the corresponding channel. In this way, the section in which each terminal performs the backoff procedure is called the contention window section.

[0056] If a specific terminal successfully accesses the channel, the corresponding terminal transmits data via the channel. However, if a terminal attempting access collides with other terminals, the collided terminals are each assigned a new random number and perform a further backoff procedure. According to one embodiment, the new random number newly assigned to each terminal is determined within a range (2*CW) that is twice the range (competition window, CW) of the random number previously assigned to the corresponding terminal. On the other hand, each terminal attempts access by performing a further backoff procedure in the next competition window period. At this time, each terminal performs the backoff procedure from the slot time remaining in the previous competition window period. In this way, each terminal performing wireless LAN communication can avoid mutual collisions with respect to a specific channel.

[0057] Hereinafter, in the present invention, a terminal can 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] <Examples of various PPDU formats>

[0059] FIG. 7 shows a PPDU format of an Extremely High Throughput (EHT) wireless LAN according to an embodiment of the present invention.

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

[0061] As shown in FIGS. 7(a) to 7(c), the PPDU is divided into a preamble and a data part. The preamble can commonly include a legacy field for backwards compatibility, namely, an L-STF (Legacy Short Training field), an L-LTF (Legacy Long Training field), an L-SIG (Legacy Signal field), and an RL-SIG (Repeated Legacy Signal field).

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

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

[0064] The U-SIG is a field newly introduced in 11be, which is an extremely high-speed communication standard, and is a field commonly included in subsequent-generation 802.11 standard PPDUs including 11be. The U-SIG field may be continuously included in the EHT PPDU and subsequent-generation wireless LAN PPDUs, and plays a role in distinguishing which generation of PPDU the PPDU is, including 11be. The U-SIG field can transmit a total of 52 bits of information in 64 FFT-based OFDM 2 symbols. The parsing of some fields of the U-SIG field may vary depending on the type of the PPDU, whether it is multi-user transmission, and whether it is OFDMA transmission.

[0065] The EHT-SIG field may functionally be composed of an EHT-VD common field, an EHT-RU (resource unit) allocation subfield, and an EHT-user specific field. Depending on the type of PPDU, whether it is multi-user transmission, and whether it is OFDMA transmission, the analysis of some fields may vary or some fields may be omitted.

[0066] At this time, the EHT-VD common field and the EHT-RU allocation field can be integrated and called the EHT-common field. The composition and deformed (compressed or omitted) form of the EHT-SIG field will be described in detail later using examples. The EHT-RU allocation field can be called the RU allocation field.

[0067] The TB PPDU shown in Fig. 7(b) is a trigger-based PPDU, which means a PPDU based on a trigger frame. That is, the PPDU shown in Fig. 7(b) is a PPDU transmitted as a response to the trigger frame, and only the U-SIG field is included after the legacy field in the preamble, and the EHT-SIG field is not included. Therefore, different from the MU / SU PPDH in Fig. 7(a), the U-SIG does not contain information for decoding the EHT-SIG, and may include information such as the presence and pattern of spatial reuse and puncturing, and the puncturing mode information for indicating the presence and pattern of puncturing.

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

[0069] FIG. 8 shows the U-SIG field of the TB PPDU according to an embodiment of the present invention.

[0070] Referring to FIG. 8, the TB PPDU based on the trigger frame may be divided into a preamble and data. The preamble may include a U-SIG field commonly included in all PPDUs and an EHT-SIG field whose field configuration and inclusion vary depending on the type of the PPDU. At this time, the U-SIG field may include a spatial reuse field for spatial reuse (SR) for the transmission of the PPDU, and a puncturing mode field for indicating the presence or absence of puncturing and the presence or absence and position of puncturing for each mode.

[0071] Spatial reuse means a method of efficiently using spatial resources by the STA adjusting and / or setting an appropriate CCA level according to the situation, and determining whether the channel is idle or occupied based on the adjusted and / or set CCA level and then transmitting a signal. That is, the STA does not uniformly apply the same CCA level to all channels, and when it is determined that the signal transmitted by the STA during SR execution does not have a large interference effect on other STAs, the CCA level is adjusted lower (or the criterion for determining whether the channel is idle is relaxed), so that transmission resources can be used more efficiently.

[0072] Fig. 8(a) shows an example of the configuration of the U-SIG field. As shown in Fig. 8(a), the U-SIG field may be composed 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] The version independent field 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 that transmits and receives the PPDU, and the TXOP field includes timing information related to the time when the PPDU transmission ends. The PPDU BW field may include bandwidth information for which the PPDU is transmitted. If some frequency bands are punctured or not allocated in the bandwidth indicated by the PPDU BW field, the frequency bands may not be used for the PPDU transmission. At this time, the PPDU BW can further indicate information regarding some of the punctured bandwidths.

[0075] Since the version independent field is not changed depending on the type of the PPDU, it may be commonly included not only in the TB PPDU but also in the MU / SU PPDU, and may also be included in the PPDUs used in standards after 11be.

[0076] The version-dependent field can include a PPDU type field (1b + a bits) and a PPDU type-specific field. The PPDU type field indicates the type of the PPDU, and the PPDU type-specific field may have sub-fields that vary depending on the type of the PPDU.

[0077] Figure 8(b) shows an example of the PPDU type-specific field of a TB PPDU. Specifically, the PPDU type-specific field of a TB PPDU can include a spatial reuse field for spatial reuse and a puncturing mode field for indicating the presence and / or position of puncturing.

[0078] At this time, a plurality of spatial reuse fields may be included depending on the bandwidth. For example, as shown in Figure 8(b), four fields of 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 region within the bandwidth indicated by the PPDU BW field of the U-SIG field.

[0079] For example, when the PPDU BW indicates 20 MHz, all of the spatial reuse fields 1 to 4 may be encoded corresponding to the 20 MHz indicated by the PPDU BW. Or, when the bandwidth is indicated as 40 MHz by the PPDU BW field, two spatial reuse fields (for example, numbers 1 and 3) may correspond to the Low 20 MHz based on the center frequency among the 40 MHz, and the remaining two spatial reuse fields (for example, numbers 2 and 4) may be encoded corresponding to the High 20 MHz.

[0080] Or, when the bandwidth is indicated as 80 MHz by the PPDU BW field, each of the four spatial reuse fields may be encoded corresponding to each of the four 20 MHz of the 80 MHz.

[0081] When the bandwidth is indicated as 160 MHz by the PPDU BW field, each of the four spatial reuse fields may be encoded corresponding to four 40 MHz of 160 MHz respectively.

[0082] When the bandwidth is indicated as 260 MHz by the PPDU BW field, each of the four spatial reuse fields may be encoded corresponding to three 20 MHz out of twelve 20 MHz of 240 MHz. At this time, the three 20 MHz corresponding to the spatial reuse field 1 (Spatial Reuse1) may be the three 20 MHz channels having the lowest frequency components within the 240 MHz bandwidth. Or, each of the remaining three spatial reuse fields may be encoded corresponding to each of the three 80 MHz within 240 MHz, and the remaining one spatial reuse field may be encoded with the same value as the three encoded spatial reuse fields.

[0083] When the bandwidth is indicated as 320 MHz by the PPDU BW field, each of the four spatial reuse fields may be encoded corresponding to four 80 MHz of 320 MHz. At this time, the 80 MHz corresponding to the spatial reuse field 1 (Spatial Reuse 1) has the lowest frequency component of 320 MHz, and the 80 MHz corresponding to the spatial reuse field 4 may have the highest frequency component.

[0084] The puncturing mode field indicates the presence and / or position of puncturing and may be encoded with 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 puncturing mode field of the trigger frame and the combined form (the form in which the TB PPDU is received) of the TB PPDUs transmitted by multiple users in the uplink may change. The reason why the discontinuous form of the PPDU and the combined form of the TB PPDU indicated by the puncturing mode change is that part or all of the RUs specified by the RA-RU (Random Access, RU) are not occupied by the STA, and a discontinuous form (unused bandwidth form) not indicated by the puncturing mode may further occur.

[0086] The Puncturing Mode field of the TB PPDU may be used for the AP and STA of the adjacent BSS to recognize where the bandwidth that is (definitely) not used among the bandwidths included in the UL BW of the TB PPDU is.

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

[0088] Specifically, as shown in (b) of FIG. 8, when the spatial reuse fields of the TB PPDU for the 320 MHz uplink bandwidth are composed of Spatial Reuse 1, 2, 3, and 4 and there are only 4 of them, each spatial reuse field corresponds to 80 MHz.

[0089] However, by setting the spatial reuse fields of the TB PPDUs transmitted in the primary and secondary to be different from each other for differentiation, a total of eight spatial reuse fields may respectively correspond to the 320 MHz uplink bandwidth. Therefore, each of Spatial Reuse 1 to 8, which are the spatial reuse fields included in the two types of TB PPDUs, may correspond to each 40 MHz of the UL TB PPDU BW (the BW represented by combining the TB PPDUs transmitted by each STA).

[0090] That is, when a non-AP STA transmits a TB PPDU instructed by a trigger frame transmitted from an AP STA, the non-AP STA can configure and transmit the spatial reuse field and the puncturing mode field included in the PPDU type identification field to be different from each other according to the position of the RU where the TB PPDU is transmitted and / or the type of the TB PPDU.

[0091] For example, when the non-AP STA is a first type of TB PPDU where the position of the RU where the TB PPDU is transmitted is the primary 160 MHz, the non-AP STA can include Spatial Reuse 1 to 4, which are spatial reuse fields, in the PPDU type identification field of the TB PPDU. However, when the non-AP STA is a second type of TB PPDU where the position of the RU where the TB PPDU is transmitted is the secondary 160 MHz, the non-AP STA can include Spatial Reuse 5 to 8, which are spatial reuse fields, in the PPDU type identification field of the TB PPDU.

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

[0093] The Non-AP STA can set Spatial Reuse 1 to 8 based on the information included in the trigger frame, and the information for setting the spatial reuse field may be included in different fields of the trigger frame depending on the position of the RU where the TB PPDU is transmitted and / or the type of the TB PPDU.

[0094] As shown in FIG. 8(b), when a single spatial reuse field corresponds to 80 MHz and the spatial reuse of another BSS is restricted by a part of 20 MHz out of 80 MHz, the problem may arise as to whether the remaining reusable 60 MHz should also be restricted in spatial reuse. 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 this purpose, the number of spatial reuse fields corresponding to each bandwidth may also increase.

[0095] However, when setting and transmitting multiple spatial reuse fields, since the size of the U-SIG field increases and the signaling overhead increases, as shown in FIG. 8(c), if the spatial reuse fields are set differently between the TB PPDUs transmitted in the primary 160 MHz and the secondary 160 MHz, more spatial reuse fields can be set and transmitted without increasing the signaling overhead.

[0096] According to an 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 the RUs of the primary 160 MHz or the secondary 160 MHz.

[0097] According to still 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 the RUs of the Low 160 MHz or the High 160 MHz.

[0098] Referring to FIG. 8(c), the TB PPDU transmitted in the RU within the primary 160 MHz can include four spatial reuse fields in the PPDU type specific field, and each of the four spatial reuse fields may correspond to each of the four 40 MHz RUs within the primary 160 MHz.

[0099] Also, the TB PPDU transmitted in the RU within the secondary 160 MHz can include four spatial reuse fields in the PPDU type specific field, and each of the four spatial reuse fields may correspond to each 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 BW and the secondary BW may have a bandwidth of 80 MHz. In this case, each of the spatial reuse fields (e.g., four spatial reuse fields) of the TB PPDU transmitted in the Priamry 80 MHz and / or the secondary 80 MH RU may correspond to each of the subchannels (20 MHz) within 80 MHz.

[0101] In this embodiment, the PPDU type specific field can further include a puncturing mode field for indicating a puncturing mode in addition to the spatial reuse field. The puncturing mode fields included may be different from each other depending on whether the position of the RU where the STA that has received the trigger frame in a manner similar to the spatial reuse field transmits the TB PPDU is the primary BW or the secondary BW. That is, the puncturing mode field 1 and the puncturing mode field 2, which are set to be different from each other depending on the bandwidth (or segment) where the RU where the TB PPDU is transmitted is located, may be included in the TB PPDU respectively.

[0102] For example, as shown in Fig. 8(c), the puncturing mode field 1 is included in the TB PPDU transmitted at the primary 160 MHz and represents the discontinuous channel form at the primary 160 MHz, and the puncturing mode field 2 can be included in the TB PPDU transmitted at the secondary 160 MHz and represents the discontinuous channel form at the secondary 160 MHz.

[0103] As shown in Fig. 8(c), when the fields indicating the puncturing mode are individually set and transmitted according to the bandwidth, compared with the method of signaling the discontinuous channel by the single puncturing mode field shown in Fig. 8(b), the form of the discontinuous channels for the entire uplink bandwidth can be signaled with higher resolution.

[0104] <Trigger Frame Format>

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

[0106] Referring to Fig. 9, the 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, Padding, and an FCS field. Some of the above fields may not be included in the trigger frame, and some fields may be further included.

[0107] The frame control field, the duration field, the RA field, and the TA field are the same as the fields included in the general MAC header of the 802.11 standard.

[0108] The common information field may include information on various parameters used when a device to which a resource unit is allocated by a trigger frame transmits a TB PPDU as a response thereto.

[0109] The user information list may include at least one user information field containing individual information for each STA. The Padding field may be included to ensure time for the generation and preparation of the TB PPDU. When the receiving device's own user information field is located at the rear in the user information list, there may be insufficient time for the receiving device to recognize the RU assigned to it and generate and transmit the TB PPDU. Therefore, by positioning the Padding field as an addition after the user information list field of the trigger frame, each receiving device can ensure sufficient time to recognize the RU and prepare the TB PPDU.

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

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

[0112] The common information field can include information / parameters that are commonly applied to all terminals that receive the trigger frame. As shown in FIG. 10, the trigger type field indicates the trigger type of the trigger frame and may be composed of 4 bits.

[0113] Table 1 below shows an example of the type of trigger frame according to the value of the trigger type field.

[0114]

Table 1

[0115] Referring to Table 1, the 4 bits of the trigger type field are encoded from '0000' to '1111' and can individually indicate the type of each trigger frame. For example, the 4 bits of the trigger type field can indicate trigger frames of the types 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), EHT-NDP Feedback Report Poll(15) according to the encoded values.

[0116] When the bit value in the trigger type field ranges from '0' to '7', it can indicate the same trigger frame type as the trigger type field of HE (802.11ax). Therefore, when the value of the trigger frame type field, where the trigger frame is a HE trigger frame based on HE, is from '0' to '7', the trigger frame may be configured identically to 802.11ax. Thus, the common information field, trigger - dependent common information field, and user field may be configured and encoded in the same format.

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

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

[0119] The additional information field may be extended with a field that is functionally identical to the field included in the trigger frame where the trigger type field value is from '0' to '7', or may be added using the Reserved field.

[0120] As shown in FIG. 10, the UL BW field may have different sizes depending on the value of the trigger type field. For example, when the value of the trigger type field is from '0' to '7', the size of the UL BW field is 2 bits. However, when the value of the trigger type field is from '8' to '15', the size of the UL BW field is 3 bits, which can represent 6 BW modes (20, 40, 80, 160 (80 + 80), 240 (160 + 80), 320 (160 + 160) MHz).

[0121] The UL spatial reuse field may have different sizes depending on the value of the trigger type field. For example, when the value of the trigger type field is from '0' to '7', the size of the UL spatial reuse field is 16 bits. However, when the value of the trigger type field is from '8' to '15', the UL spatial reuse field may be composed of 8 spatial reuse fields with a size of 4 bits, for a total of 32 bits.

[0122] The reason for the total of 8 spatial reuse fields is that when only 4 Spatial euse fields are utilized as before for 240 MHz or 320 MHz PPDUs, the BW corresponding to each spatial Reuse field reaches up to 80 MHz at most, and spatial reuse cannot operate efficiently. Therefore, when the number of spatial reuse fields increases to 8, it can correspond up to 40 MHz at most, enabling a more efficient spatial reuse operation.

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

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

[0125] Referring to FIG. 11, the trigger frame can include an additional information field depending on whether it is based on HE or EHT, and the additional information field can further include additional information for the response of the TB PPDU 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 from '8' to '15', when the trigger frame is an EHT trigger frame, the trigger frame can further include an additional trigger dependent common info subfield shown in FIG. 11 which is an additional information field.

[0127] As described above, the additional information field can include an additional bandwidth field, a puncturing mode field, and / or an additional UL spatial reuse field for additional spatial reuse. At this time, the common information fields other than the additional information field may have the same bit and field configuration for a trigger frame in which the value of the trigger type field is from '0' to '7' and a trigger frame in which the value of the trigger type field is from '8' to '15'.

[0128] The additional information field shown in FIG. 11 may be commonly included in an EHT-based trigger frame in which the value of the trigger type field is from '8' to '15', and when the value of the trigger type field is '13' (EHT-GCR MU-BAR), it may be included together with BAR Control (2O octets) and BAR Information (2O octets).

[0129] The additional information field contains additional information for generating an EHT TB PPDU when a PPDU is transmitted in 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] Also, a specific field located immediately before the additional information field can indicate whether an additional information field is included after the common information field. That is, when the value of the specific field is set to a specific value (‘1’ or ‘0’), the non-AP STA can recognize that an 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 no additional information field is included, the trigger frame may be recognized as an HE trigger frame, and the non-AP STA can respond with an HE TB PPDU. At this time, the specific field may have a size of 1 bit and may be ‘B63’, ‘B53’ or other bits.

[0131] In addition to the specific field, the non-AP STA can know whether an additional information field is included after the common information field by the identifier of the additional information field. For example, when 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] When the received trigger frame is a HE trigger frame, the Non-AP STA can respond using a HE TB PPDU, and can also respond using a HE TB PPDU or an EHT TB PPDU based on the received trigger frame. At this time, when the position of the RU allocated for transmitting the response frame to the trigger frame is located 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, when the position of the allocated RU is located in the primary BW, the Non-AP STA can respond with a HE TB PPDU or an EHT TB PPDU depending on the configuration and type of the trigger frame, but when the position of the allocated RU is located in the secondary BW, the Non-AP STA can respond only with an EHT TB PPDU.

[0133] For example, based on the format related to the trigger frame (for example, when the format of the user information field included in the trigger frame is the HE format or the EHT format), the Non-AP STA can respond with a TB PPDU or an EHT TB PPDU. Specifically, after receiving the trigger frame, when the format of the user information field included in the trigger frame is the HE format, the Non-AP STA responds with a HE TB PPDU. However, when the format of the user information field included in the trigger frame is the EHT format, the Non-AP STA can respond with an EHT TB PPDU.

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

[0135] The additional UL bandwidth (BW) field may be assigned 1 bit or 2 bits and may be interpreted in combination with the bandwidth field included in the common information field. That is, when the additional UL BW field is included in the additional information field, the non-AP STA can recognize the bandwidth for transmitting the TB PPDU by considering the additional UL BW field in addition to the bandwidth field of the common information field. In this case, 6 out of the 8 (or 16) BW modes that can be indicated by 1 bit (or 2 bits) of the additional UL BW field for the 2 bits of the bandwidth field may correspond to 20, 40, 80, 160 (80 + 80), 240 (160 + 80), and 320 (160 + 160) MHz, respectively.

[0136] The additional UL spatial reuse field can signal a value for spatial reuse operation for a frequency region not indicated by the UL spatial reuse field of the common field. By including 4 spatial reuse fields in the UL spatial reuse field of the common information field and another 4 spatial reuse fields in the additional UL spatial reuse field, a total of 8 spatial reuse fields for the entire bandwidth can be indicated. That is, the multiple spatial reuse fields included in the common information field and the additional UL spatial reuse field included in the additional information field can each indicate a frequency band for spatial reuse operation for different bandwidths.

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

[0138] That is, when a non-AP STA transmits a TB PPDU as a response to a trigger frame, depending on whether the responding TB PPDU is a HE TB PPDU or an EHT TB PPDU, it can generate the TB PPDU using at least one spatial reuse field included in a different field.

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

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

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

[0142] FIG. 12(a) shows an example of a UL spatial reuse field for uplink spatial reuse operation, which is composed of a total of eight spatial reuse fields. Four of the eight spatial reuse fields seen in the trigger frame for a bandwidth of 320 (or 160 + 160) MHz indicate values for spatial reuse corresponding to Low 160 or 80 MHz, and the remaining four can indicate values for spatial reuse corresponding to High 160 or 80 MHz.

[0143] At this time, the plurality of spatial reuse fields seen in FIG. 12(a) may be separately included in the UL spatial reuse field included in the common field and the additional UL spatial reuse field included in the additional information field. That is, some of the plurality of spatial reuse fields may be included in the UL spatial reuse field included in the common field, and the remaining spatial reuse fields may be included in the additional UL spatial reuse field included in the additional information field.

[0144] Each spatial reuse field is composed of 4 bits and can indicate a spatial reuse value applied to a bandwidth of up to 40 MHz.

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

[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. At this time, the names Low and High are just expressions used to divide the frequency band into 160 MHz + 80 MHz, and may have no relation to the actual frequency position relationship. At this time, 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 four spatial reuse fields among the eight spatial reuse fields included in the trigger frame corresponds to 40 MHz (Lowest 40 MHz, Low 40 MHz, High 40 MHz, Highest 40 MHz), and the remaining four may be encoded with the same value as the spatial reuse fields corresponding to each 40 MHz.

[0148] Also, when the trigger frame indicates a bandwidth of 80 MHz, each of four out 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 with the same values as the spatial reuse fields corresponding to each 20 MHz.

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

[0150] Also, when the trigger frame indicates a bandwidth of 20 MHz, all eight spatial reuse fields may indicate the spatial reuse values corresponding to the primary 20 MHz.

[0151] As yet another example of the present invention, the UL spatial reuse field may include four spatial reuse fields. In this case, each of the four spatial reuse fields may indicate a spatial reuse value of 80 MHz for a 320 MHz bandwidth, and may indicate a spatial reuse value of 40 MHz for a 160 MHz bandwidth. Also, for an 80 MHz bandwidth, each may indicate a spatial reuse value of 20 MHz.

[0152] When a bandwidth of 40 MHz is indicated by the trigger frame, two spatial reuse fields may each correspond to low or High 20 MHz, and the remaining two may be encoded with the same values as the spatial reuse fields corresponding to each 20 MHz. Also, when a bandwidth of 20 MHz is indicated by the trigger frame, all four spatial reuse fields may indicate the spatial reuse values corresponding to the primary 20 MHz.

[0153] (b) of FIG. 12 shows an example of a puncturing mode field (8 bits or 16 bits). The puncturing mode field indicates the form of discontinuous channels for the PPDU to which the trigger frame is transmitted. That is, the puncturing mode for the bandwidth to which the PPDU, which is the trigger frame, is transmitted may be indicated by the puncturing mode field. Here, the puncturing mode can indicate whether a part of the entire bandwidth is punctured and the position where the puncturing occurs.

[0154] The puncturing mode field (or a 16-bit bitmap) may be included in an additional information field rather than the (UL HE-SIG-A2) Reserved field of the common information field, and may include two puncturing mode sub-fields. If two puncturing mode sub-fields are included, the discontinuous form of the channel to which the trigger frame included in a 320 MHz or 240 MHz PPDU is transmitted is divided into 160 MHz bandwidth sections, and the puncturing mode sub-fields may indicate whether puncturing occurs and the puncturing position.

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

[0156] Referring to FIG. 13, when a plurality of spatial reuse fields are included in the trigger frame and transmitted, each STA can transmit a response frame as a response to the trigger frame based on the plurality of spatial reuse fields.

[0157] Specifically, STAs STA1 to STA N that have received a trigger frame from an AP STA check the UL spatial reuse field included in the common information field of the trigger frame, and can generate a TB PPDU by encoding the values of the four spatial reuse fields included in the UL spatial reuse field into spatial reuse fields 1 to 4 included in the U-SIG field of the TB PPDU, respectively.

[0158] FIGS. 14A and 14B show still other examples of the transmission of a trigger frame and a trigger frame-based TB PPDU according to an embodiment of the present invention.

[0159] Referring to FIGS. 14A and 14B, when a plurality of spatial reuse fields are indicated using a trigger frame, TB PPDUs may be generated, transmitted, and received by different spatial reuse fields, respectively.

[0160] Specifically, a plurality of spatial reuse fields may be transmitted using a trigger frame. At this time, some of the plurality of spatial reuse fields may be included in the common information field, and the remaining spatial reuse fields may be included in the additional information field.

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

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

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

[0164] At this time, when the TB PPDUs generated by STA1 to STA n are HE TB PPDUs, the spatial reuse fields 1 to 4 may be the spatial reuse fields included in the common information field of the trigger frame. When the TB PPDUs generated by STA1 to STA n are EHT TB PPDUs, the spatial reuse fields 1 to 4 may be the spatial reuse fields included in the additional information field of the trigger frame.

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

[0166] At this time, when the TB PPDUs generated by STAn+1 to STA N are HE TB PPDUs, the spatial reuse fields 5 to 8 may be the spatial reuse fields included in the common information field. When the TB PPDUs generated by STA1 to STA n are EHT TB PPDUs, the spatial reuse fields 5 to 8 may be the spatial reuse fields included in the additional information field.

[0167] In FIGS. 14A and 14B, the trigger frame can instruct the transmission of HE TB PPDU and / or 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 as a response to the trigger frame. The criteria for at least one non-AP STA to transmit a TB PPDU or an EHT TB PPDU can be based on the position of the assigned RU and / or the format associated with the trigger frame.

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

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

[0170] Referring to FIG. 15, the STA that receives the trigger frame can decode the preamble of the trigger frame to recognize the RU for uplink transmission, and can generate a TB PPDU using different spatial reuse fields of the trigger frame according to the position of the recognized RU.

[0171] Specifically, the AP STA can transmit 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] Thereafter, the non-AP STA can generate a TB PPDU to transmit the TB PPDU indicated by the trigger frame as a response to the received trigger frame. At this time, the non-AP STA can use the information included in the trigger frame for generating the TB PPDU.

[0173] Specifically, the non-AP STA can decode the trigger frame and recognize the RU assigned for transmitting its own TB PPDU by the RU allocation information field of the trigger frame. The non-AP STA determines whether the position of the RU assigned for transmitting the TB PPDU is in the high frequency band (or the primary BW including the primary channel) or the low frequency band (or the second BW not including the primary channel) based on the center frequency of the entire bandwidth. If the position of the assigned RU is in the high frequency band (or the primary BW), the non-AP STA can generate a TB PPDU by encoding the spatial reuse fields 1 to 4 included in the trigger frame into the spatial reuse fields 1 to 4 of the TB PPDU (S15020).

[0174] At this time, when the generated TB PPDU is a HE TB PPDU, the spatial reuse fields 1 to 4 of the trigger frame used for generating the TB PPDU may be the spatial reuse fields included in the common information field of the trigger frame.

[0175] On the one hand, when the allocated RU position 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 to 8 included in the trigger frame into the spatial reuse fields 1 to 4 of the TB PPDU (S15030).

[0176] At this time, when the generated TB PPDU is an EHT TB PPDU, the spatial reuse fields 5 to 8 of the trigger frame used for the generation of the TB PPDU may be the spatial reuse fields included in the additional information field of the trigger frame.

[0177] FIG. 16 shows an example of the spatial reuse operation according to the number of spatial reuse fields for a frequency band according to an embodiment of the present invention.

[0178] Referring to FIG. 16, the region of the bandwidth corresponding to the spatial reuse field and the spatial reuse result of the OBSS may change depending on the number of spatial reuse fields with respect to the bandwidth for the transmission of the PPDU.

[0179] Specifically, as shown in FIG. 16, there are four OBSSs 1 to 4 having a primary channel in a 320 MHz bandwidth in which a 320 MHz TB PPDU is transmitted, and each of the four OBSSs 1 to 4 may receive interference of -65, -60, -58, -50 dBm from the TB PPDU.

[0180] In this case, when only 4 spatial reuse fields are used, as shown in Fig. 16(a), each of the 4 spatial reuse fields may be set to a value associated with the spatial reuse limit allowed at 80 MHz. On the other hand, when 8 spatial reuse fields are used, as shown in Fig. 16(b), each of the 8 spatial reuse fields may be set to a value associated with the spatial reuse limit allowed at 40 MHz. At this time, the value set for the spatial reuse field may be set to the strictest value among the spatial reuse conditions applied to the BW corresponding to the spatial reuse field. Therefore, one spatial reuse field corresponding to 80 MHz may be set to the lower value (the value with more restricted spatial reuse) among the values of the two spatial reuse fields corresponding to the two 40 MHzs existing within 80 MHz, respectively.

[0181] As shown in Fig. 16(a) where 4 spatial reuse values are used for a 320 MHz bandwidth by the TB PPDU, the spatial reuse values of the bandwidths where the primary channels of each STA are located in OBSS1 to OBSS4 may be PSR_DISALLOW, -68 dBm, -68 dBm, PSR_DISALLOW. In this case, the STA confirms that spatial reuse operations are not allowed for OBSS1 and OBSS4 and does not attempt channel access. Also, for OBSS2 and OBSS3, although it is known that spatial reuse is allowed in the bandwidth where its primary channel exists, since its interference is greater than the spatial reuse threshold, it cannot perform the backoff procedure for channel access.

[0182] On the one hand, as shown in Fig. 16(b) where 8 spatial reuse values are used for a 320 MHz bandwidth by a TB PPDU, the spatial reuse values of the bandwidth where the primary channel of each STA is located in OBSS1 to 4 may be -72 dBm, -38 dBm, -41 dBm, and PSR_DISALLOW. In this case, it can be seen that OBSS2 and OBSS3 allow spatial reuse in the bandwidth where their primary channels exist, and since their own interference (from the TB PPDU) is smaller than the spatial reuse threshold, they can perform transmission after performing a backoff procedure for channel access.

[0183] Fig. 17 shows an example of a method for transmitting a trigger frame according to an embodiment of the present invention.

[0184] Referring to Figs. 17(a) to (c), the form of the trigger frame may be different depending on the form and number of resources to be transmitted.

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

[0186] As shown in Fig. 17(a), when a part of the operating BW of the AP is occupied by a heterogeneous device or an OBSS (BUSY as a result of CCA), the BW of the PPDU in which the trigger frame is transmitted is restricted, and the trigger frame may be transmitted only over a part of the operating BW. This is a problem that occurs when the wide bandwidth channel access method follows the channel bonding method. By utilizing the puncturing operation of the SU PPDU introduced in 11be, the trigger frame may be transmitted over a wider BW using a channel other than the channel determined to be BUSY.

[0187] As shown in FIG. 17(b), the trigger frame may be transmitted only in the remaining frequency bands excluding the channels for which the CCA result is determined to be BUSY within the operating BW. At this time, 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 including the trigger frame. At this time, the discontinuous form of the PPDU in which the trigger frame is transmitted may be restricted in accordance with the discontinuous form of the SU PPDU allowed in EHT. Also, the trigger frame may be repeatedly represented in each 20 MHz PPDU and transmitted in a discontinuous form that is not represented only in a specific channel (the channel for which the CCA result is BUSY). At this time, the transmission form of the trigger frame may be a method similar to the U-SIG transmission method represented in the punctured PPDU.

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

[0189] At this time, the two trigger frames may be transmitted by dividing the PPDU BW into two regions respectively. The criterion for dividing the PPDU BW into two regions may be whether the BW of one region is 160 MHz. That is, the PPDU BW may be divided so that the BW for one PPDU becomes 160 MHz.

[0190] Also, each trigger frame represented in two regions may be represented in a discontinuous form within each region. At this time, the discontinuous forms respectively applied to the two trigger frames may be restricted according to the discontinuous form of the SU PPDU allowed in the BW including the two trigger frames. For example, in FIG. 17(c), the discontinuous channel form allowed for Trigger 1 may be restricted to only the discontinuous channel form allowed for the 160 MHz SU PPDU.

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

[0192] When the puncturing mode is signaled by a trigger frame, the STA can include information about the puncturing mode obtained by the trigger frame in its own TB PPDU when configuring its own TB PPDU. For example, as shown in FIG. 18(a), when the signaling field of the TB PPDU includes a puncturing mode field, the OBSS that receives the TB PPDU can recognize the discontinuous form of the channel occupied by all the TB PPDUs transmitted together with the TB PPDU, even with only the 20 MHz TB PPDU signaling information obtained in its own primary channel.

[0193] Also, the information about the puncturing mode may be used so as to more finely divide the frequency region corresponding to the spatial reuse value. For example, when it is obtained by the puncturing mode information whether a part of the BW region corresponding to the spatial reuse field is punctured, the BW corresponding to the spatial reuse field may correspond only to the region other than the punctured bandwidth according to the information about the puncturing mode.

[0194] As shown in FIG. 18(b), when it is confirmed that some BWs are punctured according to the puncturing mode information in the puncturing mode field, the information in the spatial reuse field corresponding to each BW may be applied only to the remaining BWs that are not punctured among the corresponding BWs.

[0195] <Dynamic RU TB PPDU>

[0196] UL MU (UL MU-MIMO or UL OFDMA) transmission using a trigger frame and a TB PPDU allows multiple STAs to perform UL transmission simultaneously, reducing the competition among STAs and at the same time effectively solving the excessive overhead problem that may be induced by the Short PPDU (UL) transmission of a single STA. However, different from general UL PPDU transmission, each STA has a limitation that it must perform UL transmission using the RUs assigned by the AP through the trigger frame regardless of its own channel state (IDLE or BUSY).

[0197] The problem that the RU selection on the STA side described above is restricted may be caused by the fact that the TB PPDU reception procedure on the AP side is different from the general reception procedure. To help understand the TB PPDU reception process of the AP, an example of the procedure in which the STA that has received the trigger frame responds with a TB PPDU and the operation in which the AP receives the TB PPDU transmitted by each STA in UL is shown in FIGS. 19 and 20 described below.

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

[0199] Referring to an embodiment of FIG. 19, the AP can allocate RUs (484-tone-sized RUs in the Low 40MHz and High 40MHz bands respectively) to STA1 and STA2 by transmitting a trigger frame using the 80MHz band confirmed as IDLE. At this time, since the trigger frame allocates RUs located at different frequencies to the two STAs, it may be understood as a trigger frame for the UL OFDMA TB PPDU.

[0200] After receiving the trigger frame and decoding it, STA1 and STA2 that have received the trigger frame can confirm that the trigger frame contains two user information fields, and that one of the two user information fields is their own user information field. At this time, each STA can recognize its own user information field based on whether the AID12 subfield of the user information field contains information related to its own AID (for example, the LSB 12 bits of its own AID).

[0201] STA1 can confirm that the RU allocated to it is a 484-tone RU located in the Low 40MHz by the RU allocation subfield included in its own user information field. STA2 can recognize in the same way as STA1 that the RU allocated to it is a 484-tone RU located in the High 40MHz.

[0202] In addition, the trigger frame can 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 must be applied when each STA generates a TB PPDU as a response to the trigger frame. After each STA decodes and verifies the trigger frame for the RU assigned to itself, it generates a TB PPDU by applying the encoding parameters indicated by the trigger frame. The generated TB PPDUs of each STA are simultaneously transmitted in the UL, and the AP can receive a UL OFDMA PPDU in which the TB PPDUs transmitted by each STA are combined.

[0203] Considering the trigger frame transmission and the subsequent 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 in the UL. However, the AP's MAC, which is the entity that generates the trigger frame, knows the position and form of the RU it assigned to each STA, but the AP's PHY, which is the entity that separates and decodes the OFDMA TB PPDU, does not know the composition of the OFDMA TB PPDU it receives. Therefore, in the conventional 11ax standard, after the AP's MAC sublayer generates a trigger frame and requests transmission to the PHY layer, a procedure is defined to provide 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] In 11ax, after the MAC issues a transmission request for the trigger frame, the PHY-TRIGGER.request primitive is issued before the STA's TB PPDU is received as a response to the trigger frame for which the TB PPDU transmission was requested. 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 a TRIGVECTOR parameter, which includes the BW information (CH_BANDWIDTH) of the predicted TB PPDUs and the L-SIG length information (UL_LENGTH). At this time, the PHY performs preparatory work for receiving TB PPDUs, such as setting the BW in the Rx mode using the BW information and length information of the TB PPDUs transmitted from the MAC.

[0206] In addition, the TRIGVECTOR parameter includes the AID12_LIST and RU_ALLOCATION_LIST of the STAs to which RUs are assigned by the trigger frame. The AID12_LIST and RU_ALLOCATION_LIST are used to distinguish the subcarriers where the TB PPDUs of each STA exist from the TB PPDUs (OFDMA UL PPDU) received by the PHY from multiple STAs. As a result, the PHY can separate the TB PPDUs of each user from the TB PPDUs.

[0207] TRIGVECTOR includes encoding-related parameters commonly applied to TB PPDUs and MCS information utilized for the TB PPDUs of each STA. Using the encoding-related information, the PHY can decode the TB PPDUs of each STA.

[0208] Considering that, as described above, the MAC uses the TRIGVECTOR to provide the PHY with information related to the predicted TB PPDUs to be received, the reception procedure of the TB PPDU may be different from that of a general PPDU. In other words, different from when receiving a general PPDU, the PHY does not obtain information for decoding the received TB PPDUs from the preamble and SIG fields of the received TB PPDUs, but can wait for and decode the reception of the TB PPDUs based on the information provided by the MAC.

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

[0210] Referring to FIG. 20, the PHY of the AP can receive TB PPDUs predicted based on the information included in the TRIGVECTOR when the TRIGVECTOR is transmitted from the MAC sublayer.

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

[0212] The PHY that has received the TRIGGER.request primitive from the MAC can recognize from the CH_BANDWIDTH parameter among the parameters of the TRIGVECTOR that the BW of the TB PPDUs to be received is 80 MHz. Thereafter, the PHY receives the 80 MHz TB PPDUs and separates the TB PPDUs received by OFDMA into the TB PPDUs of each user using the AID12_LIST and the RU_ALLOCATION_LIST among the parameters of the TRIGVECTOR received from the MAC.

[0213] The process of separating TB PPDUs into the TB PPDUs of each STA may be performed using the AID12_LIST parameter and the RU_ALLOCATION_LIST parameter among the TRIGVECTOR parameters. For example, as shown in FIG. 20, the AID12_LIST parameter may include the AID LSB 12 bits of STA1 and STA2 as entries. Thereby, the PHY can recognize that the received TB PPDUs are a combination of the TB PPDU of STA1 and the TB PPDU of STA2. Also, the PHY can confirm from the RU_ALLOCATION_LIST information regarding the form in which the TB PPDUs of STA1 and STA2 are represented that the RU of STA1 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 the PHY grasps the positions of the RUs to which the TB PPDU1 and TB PPDU2 transmitted by STA1 and STA2 are transmitted, it can attempt to decode each of them.

[0214] Considering the above-described reception procedure of the TB PPDU, the reception of the TB PPDUs can be completed only with the information transmitted from the MAC of the receiving device to the PHY. Therefore, the receiving device can receive the TB PPDUs of the respective STAs without decoding the preambles and SIG fields of the TB PPDUs transmitted by each STA.

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

[0216] Thus, different from the reception procedure of a general PPDU, the reception of a TB PPDU may be performed based on the information provided by the MAC of the receiving device, which is the entity that generated the trigger frame, instead of obtaining information from the preamble and SIG field of the PPDU being received.

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

[0218] If a specific STA generates and UL-transmits a TB PPDU using an RU other than the RU assigned by the trigger frame, the PHY of the AP that transmitted the trigger frame may fail to separate the TB PPDU transmitted by the specific STA from the OFDMA TB PPDUs received from multiple STAs. Also, if a specific STA encodes a PPDU using a parameter value other than the parameter value indicated by the trigger frame, the PHY of the AP that transmitted the trigger frame can separate the TB PPDU of the specific STA from the received OFDMA TB PPDU, but may fail in decoding. To prevent such reception failures of TB PPDUs, STAs that transmit TB PPDUs as responses to the received trigger frames may each be restricted to generating and transmitting TB PPDUs using only the RU assigned to themselves and the indicated parameter values.

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

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

[0221] Referring to FIG. 21, when a hidden node of the AP exists on the STA side, the RU assigned by the trigger frame of the AP cannot be used by the STA for transmitting a TB PPDU.

[0222] Specifically, the AP can use a trigger frame to assign a 996-tone-sized RU located in the Low 80MHz band to STA1 and a 242+(242)+484-tone-sized RU located in the High 80MHz band to STA2. At this time, among the 160MHz bands divided and assigned to STA1 and STA2, the 20MHz band (242-tone-sized RU) not assigned to either of the two STAs may be a band in which a subchannel determined to be BUSY as a result of CCA performed by the AP before sending the trigger frame exists.

[0223] The trigger frame transmitted by the AP should be received by the STAs of the BSS operated by the AP. STA1 and STA2 can recognize their own user information fields in at least one of the user information fields included in the user information list field of the received trigger frame by means of the AID field. At this time, STA1 can recognize from the RU allocation subfield existing in its confirmed user information field that the RU allocated to it is an RU with a size of 996 tones in the Low 80MHz band, and STA2 can, in the same way as STA1, recognize that the RU allocated to it is an RU with a size of 242+(242)+484 tones located in the High 80MHz band.

[0224] After receiving the trigger frame, STA1 and STA2 that have recognized the RU allocated to them by the trigger frame must perform CCA with SIFS, which is the time interval from receiving the trigger frame to responding with a TB PPDU. At this time, the CCA may be ED-based CCA. The operation of the STA performing ED-based CCA may be performed only when the CS Required subfield represented in the common information field of the received trigger frame is 1. ED-based CCA may include either one or both of energy detect (per 20MHz CCA sensitivity) and virtual carrier sense (NAV).

[0225] In addition, the STA that performs ED-based CCA after the RU is allocated by the trigger frame can perform ED-based CCA on the entire BW region of the PPDU including the trigger frame, or can perform ED-based CCA only on the subchannel including the RU allocated to it by the trigger frame.

[0226] If, as a result of the CCA performed by the STA to which the RU is assigned by the trigger frame, at least one of the 20 MHz subchannels in which the assigned RU exists is considered BUSY, the transmission of the TB PPDU using the assigned RU cannot be performed.

[0227] STA1 and STA2 can each perform CCA on the 4 20 MHz subchannels in the Low 80 MHz band and the 3 20 MHz subchannels in the High 80 MHz band assigned to themselves. As a result of performing CCA on the subchannels existing in the RU assigned to each of them, both STAs can confirm that a part of the subchannels existing in the RU assigned to themselves (1 subchannel in the case of STA1 and 2 subchannels in the case of STA2) is BUSY. In this case, both STA1 and STA2 may not be able to transmit the TB PPDU.

[0228] Thus, when there is a subchannel considered BUSY among the 20 MHz subchannels in which the RU assigned by the trigger frame exists for the STA, the utilization of the subchannels considered to be in the IDLE state is also restricted. For such reasons, the restriction that the STA to which the RU is assigned by the trigger frame and transmits the TB PPDU in UL has to transmit the TB PPDU by fully utilizing all the RUs assigned to itself can be a major cause of reducing the efficiency of the UL OFDMA transmission performed by the trigger frame - TB PPDU exchange.

[0229] To solve the problem of the STA's utilization restriction for the RU assigned by such a trigger frame, the present invention proposes a procedure that allows the STA to adaptively change the RU for transmitting the TB PPDU based on the CCA results of the assigned RU and the 20 MHz subchannels existing in the assigned RU.

[0230] In the present invention, the meaning of "20 MHz subchannel existing in the RU" may be used to indicate the 20 MHz subchannel where the subchannel corresponding to the RU is located. That is, there is one 20 MHz subchannel included in the RU with 26, 52, 106, or 242 tone sizes, and there are two and four 20 MHz subchannels respectively included in the 484-tone and 996-tone RUs. At this time, the form of the final used RU determined by the STA based on the CCA result may be determined in consideration of the already agreed RU configuration. The above-described method for determining the form of the final used RU will be described in detail by an example described later. Briefly, one aspect of the present invention is that the STA to which the RU is assigned by the trigger frame does not directly utilize the assigned RU, but can transmit the TB PPDU in UL by utilizing all or part of the IDLE state 20 MHz subchannels existing in the assigned RU based on the CCA result.

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

[0232] Referring to FIG. 22, the device that has received the trigger frame can transmit (respond) the TB PPDU by utilizing only a part of the RUs assigned using the trigger frame.

[0233] Specifically, STA1 and STA2 can each transmit the TB PPDU in UL using only the subchannels other than the subchannels considered to be BUSY as a result of the CCA among the RUs assigned to themselves. In this way, the operation of selectively changing the RU configuration to be utilized for TB PPDU generation and transmission according to the CCA result for the 20 MHz subchannels existing in the RU assigned to the STA may be an operation that can be implemented without special performance problems. The reason is that in the process of generating the TB PPDU after the STA has received the trigger frame, the operation of the STA as shown in FIG. 22 can be implemented by adding only the procedure of updating according to the CCA result without directly utilizing the RU configuration confirmed by the trigger frame.

[0234] As described above, the operation on the STA side can be easily implemented. However, as in an embodiment of FIG. 22, when the RU assigned by the AP to each STA using the trigger frame does not match the RU occupied by the TB PPDU transmitted by each STA, the AP may fail to decode the OFDMA PPDU (TB PPDUs).

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

[0236] Referring to FIG. 23, when the RU assigned by the trigger frame and the RU in which the TB PPDU, which is a response to the trigger frame, is transmitted have different RU configurations from each other, the AP may fail in UL OFDMA reception.

[0237] Considering the TB PPDU reception procedure on the AP side described with reference to FIG. 20, it can be predicted that the PHY of the AP receives the TB PPDU1 of STA1 in a 996-tone-sized RU located in the Low 80 MHz band and the TB PPDU2 of STA2 in a 242 + 484-tone-sized RU located in the High 80 MHz band based on the TRIGVECTOR received from the MAC.

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

[0239] As described above, in order to solve the problem that the AP side cannot decode the TB PPDU transmitted in another RU configuration by the determination of each STA, rather than the RU configuration assigned using the trigger frame, a signaling or procedure that allows the AP to recognize the form of the RU utilized by each STA is required. Therefore, the present invention provides a method that allows the AP to recognize the form (RU configuration) of the TB PPDU being received through the signaling field of the TB PPDU when the AP receives the TB PPDU, and a procedure for the AP to recognize and estimate the TB PPDU form transmitted by each STA based on per 20MHz CCA.

[0240] To simplify the description of the invention to be described later, as described above, a STA to which an RU is assigned by a trigger frame does not directly utilize the RU assigned to itself, but instead utilizes only some of the RUs included in the assigned RU to construct and UL-transmit a TB PPDU due to the CCA result or implementation reasons. This can be referred to as Dynamic TB PPDU configuration and UL transmission. As an example of the Dynamic TB PPDU configuration, the configuration of the Dynamic TB PPDU means that a STA to which an 80MHz RU is assigned utilizes the 60 (20 + 40) MHz RU other than the 20MHz subchannel determined to be BUSY as a result of CCA for the assigned 80MHz RU to construct a TB PPDU. At this time, the RU utilized by each STA when constructing the Dynamic TB PPDU may be in a form that excludes not only the CCA result but also some of the subchannels determined to be IDLE among the subchannels within the assigned RU due to the limitations of the standard-allowed M-RU (Multiple RU) configuration or implementation constraints. In addition, in addition to the CCA result and the limitations of the M-RU configuration or implementation constraints, each STA may not use all of the available RUs but only some of the RUs to construct a Dynamic TB PPDU 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 multiple Dynamic TB PPDU are responded to by a single trigger frame, the AP must decode the preambles of the multiple Dynamic TB PPDU that are responded, and since the operation of decoding multiple preambles must be performed in parallel, it becomes 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 preambles of the Dynamic TB PPDU transmitted by each STA at once, it cannot decode the Dynamic TB PPDU in which the preamble has not been 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] In addition, since the reception of the Dynamic TB PPDU is performed by the PHY, after the AP's MAC constructs a trigger frame and requests transmission to the PHY, it can transmit a DYNAMIC_RU_LIST indicating whether the reception of the Dynamic TB PPDU is possible in each RU, together with the RU_ALLOCATION_LIST which is a parameter of the TRIGVECTOR, to the PHY.

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

[0247] Referring to FIG. 24, the STA to which the RU is allocated by the trigger frame can recognize whether or not it is allowed to respond with a Dynamic TB PPDU by the user identification field of the trigger frame.

[0248] The reception of the Dynamic TB PPDU by the AP is an operation not supported by the conventional 11ax standard, and may act as a factor increasing the implementation complexity of the AP that receives UL OFDMA PPDUs. Therefore, the AP can signal whether or not a Dynamic TB PPDU response is allowed as a response to the trigger frame it transmits, considering its own capability.

[0249] As an example, the AP can use a specific field of the trigger frame to indicate whether or not to allow the transmission of the Dynamic TB PPDU by the STA that responds with a TB PPDU after receiving the trigger frame.

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

[0251] As shown in FIG. 24, the user information field of the trigger frame may be composed of AID12, RU allocation, 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 sub-fields.

[0252] The AID12 field indicates the 12 least significant bits of the AID of the STA to which the RU is allocated by the user information field and which must respond to the TB PPDU. The RU allocation sub-field indicates the size and location of the RU to be used by the STA that must respond to the TB PPDU. At this time, the RU allocation sub-field may be combined with UL_BW included in the common information field of the trigger frame for interpretation.

[0253] Also, the user information field of the 11be trigger frame is generally composed of sub-fields having the same or similar functions as those of the 11ax trigger frame, and the RU allocation sub-field and the SS allocation / RA-RU information sub-field may be used to indicate the additional M-RU (Multiple RU) and the additional number of antennas (16) added in 11be.

[0254] Among the sub-fields of the user information field, the Dynamic TB PPDU Response sub-field can indicate whether the STA to which the RU is allocated by the user information field and which must respond to the TB PPDU allows a Dynamic TB PPDU response by utilizing a part of the allocated RUs according to its own CCA result. In one embodiment, when the Dynamic TB PPDU Resp sub-field is set to 1, a Dynamic TB PPDU response is allowed for the STA that receives the user information field, and when the sub-field is set to 0, it indicates that the Dynamic TB PPDU response is prohibited.

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

[0256] Or, as another example, the AP can indicate to all STAs whether a response to a Dynamic TB PPDU is allowed by 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 to a Dynamic TB PPDU when a response to a Dynamic TB PPDU 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, a Dynamic TB PPDU may not be 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 that the STA is assigned a 20 MHz RU, the STA will perform CCA on the 20 MHz subchannels existing within the 20 MHz RU and will determine that the entire 20 MHz RU is IDLE or BUSY. Therefore, the STA assigned a 20 MHz RU cannot have a basis to dynamically utilize the RU assigned to itself according to the CCA result. Also, even if the CCA result for each RU within the 20 MHz RU could be obtained, since the preamble of the TB PPDU must be configured in 20 MHz units, there is a problem that a preamble other than the small RU determined to be BUSY cannot be transmitted. Similarly, the STA assigned an RU smaller than 20 MHz is also restricted in Dynamic TB PPDU transmission for the same reasons as the STA assigned the 20 MHz RU described above.

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

[0261] Alternatively, as another method, when the RU assigned to each STA is 40 MHz or more, each STA can perform a procedure to check whether the RU assigned to itself is a multi-user (MU) RU that is also assigned to other TAs. At this time, each STA can respond with a Dynamic TB PPDU only when it has confirmed that the RU assigned to itself is a single-user (SU) RU assigned only to itself.

[0262] Furthermore, even if different RUs are assigned to each STA, if the different RUs assigned are within the same 80 MHz RU boundary, the Dynamic TB PPDU response may be restricted for the STA. This may be due to the limitation that different preambles are not represented within the 80 MHz segment. For example, if the AP uses a trigger frame to assign two 40 MHz RUs existing within the 80 MHz segment to two STAs respectively, when each STA transmits a Dynamic TB PPDU, it can respond by configuring different preambles. In this case, two different types of preambles may be represented within the 80 MHz segment, which may be an operation contrary to the principle defined in 11be. At this time, the Dynamic TB PPDU response limitation related to the above-described preamble regulation may be applied limitedly to the embodiments related to the preamble configuration of the Dynamic TB PPDU among the embodiments of the present invention described later.

[0263] In addition, the operation of the STA that responds to or receives the aforementioned Dynamic TB PPDU may be an operation that is difficult to implement for 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 and the RU configuration to be supported in the EHT-capability element. 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 exchange of Dynamic TB PPDU, 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 Fig. 25, each of the STAs can respond with information regarding the RU configuration it utilized, using the U-SIG field of the Dynamic TB PPDU to which it responds. Referring to Fig. 25(a), STA1 shows that Dynamic TB PPDU1 is responded to using the 20+(20)+40 MHz RU other than the second 20 MHz subchannel among the 80 MHz RUs assigned to itself, and STA2 can show that Dynamic TB PPDU2 is responded to using the 20 MHz RU located on the lowest side in terms of frequency position among the RUs assigned to itself. In this case, if the AP decodes at least one preamble represented in the subchannels of the Dynamic TB PPDUs transmitted by STA1 and STA2 respectively, the AP can recognize that Dynamic TB PPDU1 of STA1 is received in the 20+(20)+40 MHz RU existing in Low 80 MHz, and Dynamic TB PPDU2 of STA2 is received in the Low 20 MHz RU among the RUs existing in High 80 MHz.

[0269] As described above, the method by which each STA signals information regarding the RU form it utilized when configuring the Dynamic TB PPDU has a problem in that the expression for some RU forms may be restricted due to the limited length of the U-SIG field. Suppose the RU assigned to the STA is 320 MHz and the Dynamic TB PPDU can be configured by freely utilizing the 320 MHz assigned to the STA in units of 20 MHz RUs. Then, 16 bits must be allocated to accurately represent the form of the Dynamic TB PPDU that can be configured by the STA to which the 320 MHz RU is assigned. However, U-SIG includes a Version independent field and must include a spatial reuse field and a Puncturing mode field for OBSS, etc., and it is impossible to allocate 16 bits to indicate the form of the Dynamic TB PPDU as described above.

[0270] For these reasons, the size of the RU form - related fields available for showing 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 - RUs) that a single STA can utilize are limited. And regardless of the RU sizes assigned to the STA by the limited RU combinations, most of the 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] In addition, puncturing modes 1 and 2 may be represented in the TB PPDU U-SIG. Puncturing mode 1 may be a field in which the UL_Puncturing mode field value transmitted to each STA by the common information field of the trigger frame is simply copied / moved and represented. The UL_Punturing mode field may be a value of the puncturing mode that the AP predicts and indicates the form of the UL OFDMA PPDU it will receive as a response to the trigger frame during the process of generating the trigger frame. That is, the puncturing mode 1 field is not intended to provide information necessary for the AP to receive the Dynamic TB PPDU, and similar to the spatial reuse field, it may be information provided to assist the operation of other devices. Therefore, the puncturing mode 1 field may be a field indicated by 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 in which the STA responding to the Dynamic TB PPDU indicates the form of the RU it utilized in constructing the Dynamic TB PPDU. Therefore, the puncturing mode 2 fields of (Dynamic) TB PPDU U-SIGs transmitted by different STAs (in different 80 MHz segments) may have different values. An example of signaling using the puncturing mode 2 field will be described with reference to FIG. 28 below.

[0276] The Segment location field plays a role of providing information regarding in which segment of the operating bandwidth of the AP receiving the TB PPDU the detected preamble is located when the OBSS device detects the preamble of the TB PPDU in a specific segment. An example of signaling using the Segment location field will be described with reference to an example in FIG. 28 below.

[0277] As described above, the RU combinations that can be utilized by the STA to which the RU is assigned by the trigger frame for the Dynamic TB PPDU configuration may be restricted to a specific form in consideration of the complexity and efficiency of implementation. For example, the RUs that can be assigned to a single STA using the trigger frame may be restricted 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, the 100 MHz RU (RU with 996 + 242 tone sizes) and the 140 MHz RU (RU with 242 + 484 + 996 tone sizes) may be excluded because their gains are not greater than those of the 80 MHz RU and the 120 MHz RU and they increase the implementation complexity. At this time, the types of RUs assigned to a single STA by the trigger frame of the 240 / 320 MHz PPDU may also be restricted for the reasons described above. At this time, the restricted form of the RU types may be Mandatory Multiple-RU.

[0278] According to an embodiment of the present invention, when a single STA configures a Dynamic TB PPDU by utilizing a part of the RUs assigned to itself, the configured Dynamic TB PPDU may be restricted to have a restricted form, and the restricted form of the Dynamic TB PPDU may be signaled with a 4-bit bitmap.

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

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

[0281] If, after the STA receives a trigger frame, it performs CCA on the eight 20 MHz subchannels included in the allocated 160 MHz RU, and if one or both of the two subchannels located at the lowest frequency position are determined to be BUSY, the Puncturing mode2 of the Dynamic TB PPDU U-SIG can be indicated as 0111. At this time, even if only one of the two subchannels located at the lowest frequency position is BUSY, the STA must utilize the 120 MHz RU (RU with a tone size of 484 + 996) other than the two subchannels in the allocated 160 MHz RU to form a Dynamic TB PPDU.

[0282] In still another embodiment, if the STA performs CCA on the eight 20 MHz subchannels included in the allocated 160 MHz RU and as a result can only utilize an 80 MHz RU due to the above-described RU form limitation, the Puncturing mode2 field may be set to 0011 or 1100, and the STA can configure and perform UL transmission of a Dynamic TB PPDU by only utilizing the 80 MHz RU.

[0283] When considering the above-described puncturing mode 2 (RU structure of Dynamic TB PPDU) signaling method using the 4-bit size bitmap of the present invention, it can be seen that the minimum size of the RU that the STA can indicate by utilizing the Puncturing mode2 field is 1 / 4 of the RU size allocated to itself. Therefore, as in this embodiment, when a 160 MHz RU is allocated 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 using the Dynamic TB PPDU.

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

[0285] Referring to FIG. 28, the STA may allocate RUs by a trigger frame transmitted in a 160 MHz band, and both STAs may transmit responses to the trigger frame using a Dynamic TB PPDU of a U-SIG field including a puncturing mode and a segment position field.

[0286] In FIG. 28, STA1 is allocated an 80 MHz RU corresponding to segment 1 located at the lower frequency by the trigger frame, and STA2 is allocated a 20+(20)+40 MHz RU included in segment 2 located at the higher frequency by the trigger frame. Each of STA1 and STA2 can configure and UL transmit Dynamic TB PPDUs 1 and 2 by utilizing a 20+(20)+40 MHz RU and a 20 MHz RU respectively, due to the CCA result and the RU form limitation.

[0287] At this time, the puncturing mode 1 field included in the U-SIG field of the Dynamic TB PPDUs transmitted by STA1 and STA2 respectively has the same value as each other, but the puncturing mode 2 field and the 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 described above, it indicates the form information of the UL OFDMA PPDU expected to be responded to by the trigger frame. Therefore, the puncturing mode 1 field is indicated by the same value in all TB PPDUs responded to by a single trigger frame.

[0289] In the configuration of the puncturing mode 2 field, as described in the embodiment of FIG. 27 above, each STA can signal with different values to indicate the form of the RU it utilizes. Therefore, STA1 signals by setting the puncturing mode 2 field to 1011 to indicate that its Dynamic TB PPDU1 is configured by utilizing the 20+(20)+40 MHz RU located in segment 1, and STA2 signals with the puncturing mode 2 field set to 1000 to indicate that Dynamic TB PPDU2 is configured by utilizing the 20 MHz located at the lowest frequency of segment 2 where its assigned RU exists.

[0290] Also, each STA can use the segment position field to indicate information about which segment its transmitted TB PPDU is located in among the BWs represented by the TB PPDUs responded with UL OFDMA. The segment position field may be provided so that the STA that detects the preamble of a specific TB PPDU can confirm information regarding the frequency region represented by the TB PPDUs transmitted together with the TB PPDU. At this time, 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 the STA confirms that the BW of the TB PPDU is 160 MHz and the segment position field is 00 in the preamble it detected, it can confirm that the TB PPDU it detected or the TB PPDUs responded together with the detected TB PPDU are transmitted over a 160 MHz BW, and the position of the detected TB PPDU is 80 MHz located at the lower frequency side.

[0291] One embodiment of the present invention contemplates a 2-bit example of the segment position field. Thus, the four segments included in the maximum 320 MHz PPDU can be respectively indicated as 00, 01, 10, and 11 starting from the segment located at the lower side frequency. If, as in one embodiment of FIG. 27, an RU is assigned to a specific STA across 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 that responds to a Dynamic TB PPDU does not configure the TB PPDU U-SIG by utilizing the value represented in the trigger frame that requests the Dynamic TB PPDU. After making a determination on its own CCA result and RU configuration, it must have a procedure of configuring the U-SIG field.

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

[0294] To solve such a problem, when an AP allows one or more STAs to respond with 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 receives the trigger frame can respond to the TB PPDU after PIFS instead of SIFS.

[0295] In FIG. 28, Dynamic TB PPDUs 1 and 2 received as responses to the trigger frame can have different U-SIG field configurations. In order for the AP to understand the form of the RU in which Dynamic TB PPDUs 1 and 2 are transmitted, at least one subchannel represented by each of the two Dynamic TB PPDUs 1 and 2 must be decoded. However, the AP has a problem in that it does not know which subchannels among the subchannels included in the RU assigned to each STA are excluded in each Dynamic TB PPDU response process. Therefore, the operation of decoding at least one subchannel represented by each Dynamic TB PPDU is very difficult to implement on the AP side. In order to alleviate such a problem, it is necessary to set in advance the subchannels that must be obligatorily occupied when responding to the Dynamic TB PPDU.

[0296] FIG. 29 shows an example related to the setting and utilization of subchannels for the transmission of TB PPDH according to an embodiment of the present invention.

[0297] Referring to FIG. 29, the AP uses a 320 MHz trigger frame to assign one 80 MHz RU located in each segment to each of STAs 1 to 4, and considers the situation where each STA is allowed to respond with a Dynamic TB PPDU. The AP can indicate to each STA the subchannels that should be occupied when responding with a Dynamic TB PPDU. For example, in FIG. 29, it shows a situation where the AP instructs STA1 to occupy the third subchannel and STAs 2 to 3 to occupy the first subchannel respectively. Each STA must obligatorily occupy the subchannel indicated by the AP among the four subchannels of the segment where the RU assigned to it is located and respond with a Dynamic TB PPDU. In the case of STA4 to which an 80 MHz RU located in segment 4 is assigned, as a result of CCA, since the CCA result of the first subchannel (the subchannel located at the lowest frequency within the segment) indicated by the AP is determined to be BUSY, it cannot utilize the 60 MHz RUs other than the subchannel determined to be BUSY and gives up transmitting a Dynamic TB PPDU.

[0298] In this way, when the STA that responds with a Dynamic TB PPDU is instructed (by the AP) to necessarily occupy or when a pre-agreed Mandatory subchannel is set, the AP can reduce a lot of burden when performing the operation of receiving at least one preamble of the Dynamic TB PPDU to be responded simultaneously. At this time, the Mandatory subchannel of the primary 80 MHz segment may be fixed to the P20 channel. That is, when the STA to which an RU including the primary 20 MHz subchannel is assigned constructs a Dynamic TB PPDU, the configuration of the Dynamic TB PPDU not including the primary 20 MHz 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 can accept Dynamic TB PPDUs.

[0300] <Example of Procedure 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 STAs (APs and non-APs) for the invention in which the AP obtains the information necessary for receiving the Dynamic TB PPDU by decoding the preamble of the TB PPDU 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 signal 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 positions of the TB PPDUs transmitted by each STA, when a TB PPDU is received as a response to the trigger frame, by attempting signal detection on the subchannels predicted to be represented by the TB PPDU, it can be confirmed whether the predicted TB PPDU is represented or some subchannels are not utilized. By confirming that the RU assigned to a specific STA is not utilized, it can be recognized that the unutilized RU has been excluded from the TB PPDU configuration. As a simple example, after the AP assigns an 80 MHz RU to a specific STA using a trigger frame, it can be predicted that an 80 MHz TB PPDU will be responded as a response to the trigger frame. At this time, signal detection can be performed on the four subchannels existing within the 80 MHz RU where the TB PPDU is expected to be responded. As a result of the signal detection, if signals are detected only on three subchannels, it can be confirmed that the remaining one subchannel, rather than the three subchannels where the signals are detected, is the subchannel excluded by the STA in the process of constructing the Dynamic TB PPDU.

[0305] Thus, when the AP independently grasps the form of the TB PPDU responded by each STA using signal detection, the STA that responds with a Dynamic TB PPDU after receiving the 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] In another aspect of the effects obtained by utilizing the present invention, the AP has the advantage that it can interrupt additional processing for TB PPDUs determined to be undecodable among the TB PPDUs UL-transmitted by each STA based on the signal detection results for the received TB PPDU.

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

[0308] Referring to FIG. 30(a), the AP allocated the 80 MHz RU of segment 1 and the 20+(20)+40 MHz RU of segment 2 to STA1 and STA2 respectively using a 160 MHz trigger frame (allowing Dynamic TB PPDU responses), and STA1 and STA2 that received the trigger frame respond with Dynamic TB PPDU1 and 2 respectively.

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

[0310] When performing signal detection, the AP can utilize not only the BW of the TB PPDU for which reception is predicted but also information regarding the timing at which the TB PPDU is received. In the conventional 11ax standard, a STA to which an RU is allocated by a trigger frame must respond with a TB PPDU using the allocated RU after SIFS. Considering such a time regulation for the TB PPDU response, the AP can predict that a TB PPDU will be received at a specific time (for example, SIFS (+ propagation delay)) after the end of transmission of the trigger frame after transmitting the trigger frame.

[0311] Therefore, the AP can specify 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 for which reception is predicted. At this time, based on the predicted time information for which the reception is predicted, the AP can attempt signal detection for a part of the time interval in which the preamble of the TB PPDU is predicted to be detected.

[0312] (b) of FIG. 30 shows an example of a detection result obtained when an AP performs signal detection on a TB PPDU. As shown in (a) of FIG. 30, if STA1 utilizes a 20+(20)+40 MHz RU and STA2 utilizes a 20 MHz RU to respond to Dynamic TB PPDUs 1 and 2, the result of the signal detection performed by the AP is that a high signal level is measured in the subchannels utilized by each STA when constructing the Dynamic TB PPDU, and a low signal level will be measured for subchannels not utilized for Dynamic TB PPDU transmission.

[0313] The AP can determine whether reception of a TB PPDU has started on each subchannel by considering the intensity of the signals detected on the respective subchannels. As a simple example, as shown in FIG. 30(b), the AP can complete the above-described signal detection based on whether the signals detected on each subchannel exceed a specific threshold value. At this time, since the signal detection performed by the AP may be performed in accordance with the timing when the preamble of the TB PPDU is received, unlike a general per 20 MHz CCA, it may be performed by a PD (preamble detection) method or by performing ED (energy detection), but using a value different from the ED threshold value for general PIFS-based channel access.

[0314] As described above, after confirming, by utilizing signal detection, the subchannels on which the AP has started receiving a TB PPDU, it is possible to predict the RU configuration of the Dynamic TB PPDU transmitted by each STA based on the reception form of the confirmed TB PPDU.

[0315] In FIG. 30, as a result of signal detection, it can be determined that the AP received the TB PPDU as 1011 in segment 1 and 1000 in segment 2. At this time, since the 80 MHz RU of segment 1 was allocated from STA1 using the trigger frame, the AP can recognize that it is responding with a Dynamic TB PPDU by utilizing the 20+(20)+40 MHz RU other than one subchannel among the 80 MHz RUs allocated to STA1. At this time, the determination of the Dynamic TB PPDU form of STA2 may be performed in the same manner as the process of grasping the Dynamic TB PPDU of STA1 described above.

[0316] The above-described process of grasping the Dynamic TB PPDU form will be briefly described in relation to the operations performed by the AP's PHY. After the AP's PHY receives a request from the MAC to transmit a trigger frame, parameters such as the RU_ALLOCATION_LIST and DYNAMIC_RU_LIST may be transmitted by the TRIGVECTOR. Thereafter, the PHY attempts to detect the signal of the TB PPDU according to the time when the TB PPDU is expected to be responded, and determines whether the TB PPDU is received on each subchannel. At this time, the signal detection may be limitedly performed only on the subchannels where the Dynamic TB PPDU can be received based on the information of the DYNAMIC_RU_LIST parameter.

[0317] Based on the signal detection result, the AP's PHY can modify the RU configuration of the STA confirmed by the RU_ALLOCATION_LIST parameter. As a result, even if the Dynamic TB PPDU is responded using an RU with a configuration different from the RU allocated by the MAC using the trigger frame, the PHY can appropriately separate and decode the TB PPDU of each STA.

[0318] By utilizing the above-described embodiment of the present invention, the AP can independently receive the Dynamic TB PPDU responded by each STA without additional signaling using the TB PPDU U-SIG. However, the signal detection method as shown in FIG. 30(b) described above may be somewhat inaccurate. Therefore, for the AP, it may misjudge the subchannel on which the TB PPDU is received. Therefore, in order to improve the accuracy of the above-described signal detection, a signal detection method for adaptively adjusting and applying a threshold is required.

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

[0320] Referring to FIG. 31, in the signal detection process for confirming whether the TB PPDU has been received, different thresholds may be applied to the regions where the TB PPDUs of different STAs are predicted to be received.

[0321] In FIG. 31, the AP can perform signal detection by applying different thresholds to the RUs assigned to different STAs. After the AP transmits the trigger frame, a situation may be assumed where it is predicted that the TB PPDU1 of STA1 will respond in segment 1 and the TB PPDU2 of STA2 will respond in segment 2. At this time, the AP applies a threshold of -x dBm to the four subchannels where the TB PPDU1 is predicted to be received to confirm whether the TB PPDU1 is represented, and a threshold of -y dBm can be applied to the four subchannels where the TB PPDU2 is predicted to be received.

[0322] The reason for utilizing different thresholds to detect the TB PPDUs of different STAs in this way is that each STA that has received the trigger frame may have a different distance from the AP, and also 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 the AP indicates a UL Target RSSI of 90 to STA1 to instruct it to satisfy -20 dBm, a signal received at -40 dBm does not have to be a signal detected from the TB PPDU to which the STA1 responded. On the other hand, if the AP indicates a UL Target RSSI of 0 to STA2 to instruct it to satisfy -110 dBm, the signal detection result using -40 dBm as a threshold can ignore the TB PPDU signal to which the STA2 responded.

[0324] Therefore, when detecting a TB PPDU to which each STA responds, the AP can apply different thresholds in consideration of the Target RSSI values indicated to each STA. For this purpose, the MAC of the AP must transmit an RU (subchannel)_(target)RSSI_LIST to the PHY in the TRIGVECTOR to be transmitted.

[0325] According to an embodiment of the present invention described above, signal detection can be performed on TB PPDUs responded using different Target RSSI values. However, if signal interference occurs in some of the subchannels in which signal detection is performed by other devices, it may be confirmed that the signal detection results for the some subchannels are different from the actual TB PPDU reception form.

[0326] In this way, in order to correct possible signal detection errors caused by signals of other devices, the AP can determine whether a TB PPDU is represented based on a threshold in the process of performing signal detection, and at the same time, further confirm whether a signal of a certain intensity is received in the subchannels predicted to respond to the TB PPDU of each STA.

[0327] In the WiFi standard, when the PPDU transmitted by the STA (AP, non-AP) has a BW exceeding 20 MHz, it is recommended that the intensity of the signal emitted by the PPDU on each subchannel be constant (for example, the maximum deviation is +-4 dB). Therefore, among the signals confirmed on each subchannel, if there is a subchannel where the intensity of the signal with a certain level or above is different from that of the signals confirmed on other subchannels, the signal detected from the subchannel can be determined to be received from another device. At this time, it can be said that the method of comparing the intensity of the signal and detecting the signal received from another device is a signal detection error method using signal flatness.

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

[0329] Referring to FIG. 32, the AP performs signal detection to confirm the RU configuration of the Dynamic TB PPDU of STA1 and STA2, and utilizes different thresholds for the subchannels where the TB PPDU of each STA is predicted 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 the TB PPDU of STA2 is predicted to be received.

[0331] However, the PHY of the AP can confirm that among the signals detected in segment 2, the intensity of the signal confirmed in the first (the leftmost in the figure) subchannel is different from the signals confirmed in the remaining second, third, and fourth subchannels. Based on this, it can be grasped that the signals detected in the first subchannel and the remaining subchannels are different signals. In this case, in order for the AP to confirm whether the Dynamic TB PPDU transmitted by STA2 in the UL is a 20MHz TB PPDU represented in the first subchannel or a 20+40MHz TB PPDU that utilizes the remaining three subchannels, it can attempt decoding for both of them respectively.

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

[0333] FIG. 33 is a flowchart showing an example of a method by which a non-AP STA according to an embodiment of the present invention transmits a response frame to a trigger frame.

[0334] Referring to FIG. 33, if the non-AP STA receives a trigger frame instructing the transmission of a TB PPDU from the AP, it can generate and respond with a TB PPDU according to the type and format of the responding TB PPDU.

[0335] Specifically, the non-AP STA can receive a trigger frame instructing the transmission of a TB PPDU from the AP (S33010). The trigger frame can include a common information field including a first plurality of spatial reuse fields. Further, the trigger frame can further include an additional information field including a second plurality of spatial reuse fields, and whether the trigger frame includes the additional information field is identified based on the identification information of the trigger frame.

[0336] That is, it may be identified whether the trigger frame includes a second plurality of spatial reuse fields based on the identification information included in the trigger frame.

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

[0338] The configuration of the trigger frame may be the same as the trigger format described in FIGS. 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 configurations of the additional information field and / or the user information field may vary depending on the type and / or format of the trigger frame.

[0339] At this time, the user information field for each non-AP STA may be in the EHT format or the HE format according to the format of the TB PPDU indicated by the trigger frame.

[0340] At this time, the first plurality of spatial reuse fields included in the common information field may be used for the position of the RU for transmitting the TB PPDU that is a response to the trigger frame to be in the upper frequency band (or, primary BW), or may be used for generating the HE TB PPDU when the TB PPDU is an HE TB PPDU. That is, the first plurality of spatial reuse fields may be encoded into the spatial reuse fields of the TB PPDU.

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

[0342] Alternatively, depending on the format associated with the trigger frame (e.g., the format of the user information field), the first plurality of spatial reuse fields or the second plurality of spatial reuse fields may be used for generating a TB PPDU that is a response frame.

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

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

[0345] That is, the non-AP STA determines the format of the response frame for the trigger frame and can generate a TB PPDU, which is the response frame, according to the determined format. At this time, the TB PPDU, which is the response frame, may be generated based on the information obtained from the first plurality of spatial reuse fields or the 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, when the format of the user information field of the trigger frame is the HE format, the format of the TB PPDU is determined to be the HE TB PPDU and may be generated based on the first plurality of spatial reuse fields. That is, the response frame may be generated based on the information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

[0346] The first plurality of spatial reuse fields or the second plurality of spatial reuse fields for the generation of the TB PPDU may also be selected according to the position of the RU assigned for the transmission of the TB PPDU indicated by the trigger frame. That is, if the position of the RU is in the upper frequency band (or, Priamry BW), the TB PPDU may be generated based on the first plurality of spatial reuse fields, and if the position of the RU is in the lower frequency band (or, Secondary BW), the TB PPDU may be generated based on the second plurality of spatial reuse fields.

[0347] Thereafter, the non-AP STA can transmit, as a response to the trigger frame, a response frame generated based on the information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields (S34030). 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.

[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 plurality of spatial reuse fields.

[0349] Also, 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] Also, whether the response frame is generated based on the information obtained from the first plurality of spatial reuse fields or the information obtained from the 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 that indicates the resource unit to which the response frame is transmitted. The trigger frame may further include at least one of a puncturing mode field that indicates the presence or absence of puncturing and the punctured position in the bandwidth indicated by the bandwidth field and / or the additional bandwidth field.

[0352] Also, the non-AP STA can recognize the resource unit to which the response frame is transmitted based on the resource allocation field included in the trigger frame, and can generate the response frame based on the information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields according to the position on the frequency axis of the resource unit to which the response frame is transmitted.

[0353] When the response frame is generated based on the second plurality of 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 a plurality of spatial reuse fields, and each of the plurality of spatial reuse fields may be set based on information obtained from each of the corresponding first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

[0355] Whether the trigger frame includes the additional information field may be recognized by whether the value of a specific subfield indicating whether to include the additional information field and / or the value of the identifier of the additional information field is set to a specific value in the common information field.

[0356] Also, the response frame may be transmitted in the form of a TB PPDU as described above, and the TB PPDU may be 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 and transmitted in the form of an A (aggregated)-PPDU. At this time, 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 from each other.

[0357] FIG. 34 is a flowchart showing an example of a method for an AP STA according to an embodiment of the present invention to receive a response frame for a trigger frame.

[0358] Referring to FIG. 34, the AP can transmit a trigger frame instructing the transmission of a TB PPDU, and can receive at least one TB PPDU from at least one non-AP STA as a response thereto. At this time, when 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 instructing the transmission of a TB PPDU (S34010). The trigger frame can include a common information field including a first plurality of spatial reuse fields. Also, the trigger frame can further include an additional information field including a second plurality of spatial reuse fields, and whether the trigger frame includes the additional information field is identified based on the identification information of the trigger frame.

[0360] That is, whether the trigger frame includes a second plurality of spatial reuse fields may be identified by the identification information included in the trigger frame.

[0361] For example, as described above, the trigger frame can include a first plurality of spatial reuse fields (spatial reuse fields 1 to 4) in the common information field, and depending on the identification information (e.g., 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', etc.), the trigger frame can include an additional information field including a second plurality of spatial reuse fields (spatial reuse fields 5 to 8).

[0362] The configuration of the trigger frame may be the same as the trigger format described in FIGS. 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 the user information field may vary depending on the type and / or format of the trigger frame.

[0363] At this time, the user information field for each non-AP STA may be in the EHT format or the HE format according to the format of the TB PPDU indicated by the trigger frame.

[0364] At this time, the first plurality of spatial reuse fields included in the common information field may be used for the generation of the HE TB PPDU when the position of the RU for transmitting the TB PPDU that is a response to the trigger frame is in the upper frequency band (or, the primary BW), or when the TB PPDU is an HE TB PPDU. That is, the first plurality of spatial reuse fields may be encoded into the spatial reuse field of the TB PPDU.

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

[0366] Alternatively, depending on the format associated with the trigger frame (e.g., the format of the user information field), the first plurality of spatial reuse fields or the second plurality of spatial reuse fields may be used for the generation of the TB PPDU that is the response frame.

[0367] For example, when the format associated with the trigger frame is the HE format (e.g., when the format of the user information field is the HE format), the response frame, i.e., the TB PPDU, is generated as an HE TB PPDU using the first plurality of spatial reuse fields. However, when the format associated with the trigger frame is the EHT format (e.g., when the format of the user information field is the EHT format), the response frame, i.e., the TB PPDU, is generated as an EHT TB PPDU using the second plurality of spatial reuse fields.

[0368] Thereafter, 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 the information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

[0369] The response frame, i.e., the TB PPDU, may be generated based on the information obtained from the first plurality of spatial reuse fields or the 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, when the format of the user information field of the trigger frame is the HE format, the format of the TB PPDU is determined to be the HE TB PPDU and may be generated based on the first plurality of spatial reuse fields. That is, the response frame may be generated based on the information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

[0370] The first plurality of spatial reuse fields or the second plurality of spatial reuse fields for generating the TB PPDU may also be selected according to the positions of the RUs allocated for transmitting the TB PPDU indicated by the trigger frame. That is, if the position of the RU is in the upper frequency band (or, Priamry BW), the TB PPDU may be generated based on the first plurality of spatial reuse fields, and if the position of the RU is in the lower frequency band (or, Secondary BW), the TB PPDU may be generated based on the second plurality of spatial reuse fields.

[0371] 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.

[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 plurality of spatial reuse fields.

[0373] Also, 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. That is, the response frame may be generated based on the information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

[0374] The first plurality of spatial reuse fields or the second plurality of spatial reuse fields for generating the TB PPDU may also be selected according to the positions of the RUs allocated for transmitting the TB PPDU indicated by the trigger frame. That is, if the position of the RU is in the upper frequency band (or, Priamry BW), the TB PPDU may be generated based on the first plurality of spatial reuse fields, and if the position of the RU is in the lower frequency band (or, Secondary BW), the TB PPDU may be generated based on the second plurality 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 plurality of spatial reuse fields.

[0376] Also, 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] Also, whether the response frame is generated based on the information obtained from the first plurality of spatial reuse fields or the information obtained from the second plurality of spatial reuse fields may be determined based on the position on the frequency axis of the resource unit where 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 where the response frame is transmitted, and the trigger frame may further include at least one of a puncturing mode field indicating the presence or absence of puncturing and the punctured position in the bandwidth indicated by the bandwidth field and / or the additional bandwidth field.

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

[0380] When the response frame is generated based on the second plurality of 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 a plurality of spatial reuse fields, and each of the plurality of spatial reuse fields may be set based on information obtained from each of the corresponding first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

[0382] Whether the trigger frame includes the additional information field may be recognized by whether the value of a specific subfield indicating whether 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.

[0383] In addition, 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 by being 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. At this time, 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 from each other.

[0384] The foregoing description of the present invention is for illustrative purposes, and it should be understood that those with ordinary knowledge in the technical field to which the present invention pertains can easily transform it into other specific forms without changing the technical idea and essential features of the present invention. Therefore, it must be understood that the embodiments described above are illustrative in every aspect and not restrictive. For example, each component described as a single type may be implemented dispersedly, and similarly, components described as being dispersed may also be implemented in a combined form.

[0385] The scope of the present invention is indicated by the claims described below, rather than the above detailed description, and any changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included within the scope of the present invention.

Claims

1. A terminal of a wireless communication system, A communication module; a processor for controlling the communication module; The processor, Receive a trigger frame from an AP (Access Point); the trigger frame includes a common information field including a first plurality of spatial reuse fields, and whether or not the trigger frame includes an additional information field including a second plurality of spatial reuse fields is identified based on identification information of the trigger frame; transmitting a response frame generated based on information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields in response to the trigger frame; A terminal, wherein whether the response frame is generated based on the first plurality of spatial reuse fields or the second plurality of spatial reuse fields is determined based on a format associated with the trigger frame.

2. 2. The terminal of claim 1, wherein if a format associated with the trigger frame is an Extremely High Throughput (EHT) format, the response frame is generated based on information obtained from the second plurality of spatial reuse fields.

3. 2. The terminal of claim 1, wherein if a format associated with the trigger frame is a High Efficiency (HE) format, the response frame is generated based on information obtained from the first plurality of spatial reuse fields.

4. 2. The terminal of claim 1, wherein 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 a position on a frequency axis of a resource unit from which the response frame is transmitted.

5. The terminal of claim 1 , wherein the trigger frame further comprises a bandwidth field, an additional bandwidth field, and a resource allocation field indicating resource units in which the response frame is to be transmitted.

6. The processor, Identifying the resource unit in which the response frame is to be transmitted based on the resource allocation field; 6. The terminal of claim 5, further comprising: a response frame generating unit configured to receive the response frame from the resource unit and a response frame receiving unit configured to receive the response frame from the resource unit.

7. The terminal of claim 5 , wherein the trigger frame further includes a puncturing mode field indicating whether or not puncturing is performed in the bandwidth indicated by the bandwidth field and / or the additional bandwidth field, and a puncturing position.

8. 2. The terminal of claim 1, wherein when the response frame is generated based on the second plurality of spatial reuse fields, the response frame is transmitted at a bandwidth indicated by a bandwidth field included in the common information field and an additional bandwidth field included in the additional information field.

9. the response frame includes a plurality of spatial reuse fields; The terminal of claim 1 , wherein each of the plurality of spatial reuse fields is configured based on information obtained from a corresponding one of the first plurality of spatial reuse fields or the second plurality of spatial reuse fields.

10. 2. The terminal of claim 1, wherein whether the trigger frame includes the additional information field is recognized based on whether a value of a specific subfield indicating whether the additional information field is included in the common information field and / or whether a value of an identifier of the additional information field is set to a specific value.

11. The response frame is a TB PPDU (Trigger based Physical layer Protocol Data Unit), The TB PPDU is transmitted in the form of an A(aggregated)-PPDU by aggregating it with at least one TB PPDU transmitted from at least one other terminal instructed to transmit a TB PPDU by the trigger frame; 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; The terminal of claim 1 , wherein the TB PPDU and the at least one TB PPDU are generated based on different spatial reuse fields.

12. A method for a terminal to transmit data in a wireless communication system, comprising: receiving a trigger frame from an access point (AP), the trigger frame including a common information field including a first plurality of spatial reuse fields, and identifying whether the trigger frame includes an additional information field including a second plurality of spatial reuse fields based on identification information of the trigger frame; and transmitting a response frame generated based on information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields in response to the trigger frame, wherein whether the response frame is generated based on the first plurality of spatial reuse fields or the second plurality of spatial reuse fields is determined based on a format associated with the trigger frame.

13. 13. The method of claim 12, wherein if a format associated with the trigger frame is an Extremely High Throughput (EHT) format, the response frame is generated based on information obtained from the second plurality of spatial reuse fields.

14. 13. The method of claim 12, wherein if a format associated with the trigger frame is a High Efficiency (HE) format, the response frame is generated based on information obtained from the first plurality of spatial reuse fields.

15. 13. The method of claim 12, wherein 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 a position on a frequency axis of a resource unit from which the response frame is transmitted.

16. The method of claim 12 , wherein the trigger frame further includes a bandwidth field, an additional bandwidth field, and a resource allocation field indicating resource units in which the response frame is to be transmitted.

17. identifying the resource unit in which the response frame is to be transmitted based on the resource allocation field; and 17. The method of claim 16, further comprising: generating a response frame based on information obtained from the first plurality of spatial reuse fields or the second plurality of spatial reuse fields according to a position on a frequency axis of the resource unit from which the response frame is transmitted.

18. 17. The method of claim 16, wherein the trigger frame further includes a puncturing mode field indicating whether and where puncturing is performed in the bandwidth indicated by the bandwidth field and / or the additional bandwidth field.

19. 13. The method of claim 12, wherein when the response frame is generated based on the second plurality of spatial reuse fields, the response frame is transmitted at a bandwidth indicated by a bandwidth field included in the common information field and an additional bandwidth field included in the additional information field.

20. 13. The method of claim 12, wherein the response frame includes a plurality of spatial reuse fields, each of the plurality of spatial reuse fields being set based on information obtained from a corresponding one of the first plurality of spatial reuse fields or each of the second plurality of spatial reuse fields.

21. The method according to claim 12, wherein whether the trigger frame includes the additional information field is recognized by whether a value of a specific subfield indicating whether the common information field includes the additional information field and / or a value of an identifier of the additional information field is set to a specific value.

22. The response frame is a TB PPDU (Trigger based Physical layer Protocol Data Unit), The TB PPDU is transmitted in the form of an A(aggregated)-PPDU by aggregating it with at least one TB PPDU transmitted from at least one other terminal instructed to transmit a TB PPDU by the trigger frame; 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; The method of claim 12 , wherein the TB PPDU and the at least one TB PPDU are generated based on different spatial reuse fields.

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