A wireless communication method and a wireless communication terminal

Abstract

A wireless communication method and a wireless communication terminal are disclosed. A wireless communication terminal that performs wireless communication includes: a transceiver unit; and a processor. The processor receives a PLCP protocol data unit (PPDU) through the transceiver unit, and accesses a channel based on whether the PPDU is an inter-BSS PPDU or an intra-BSS PPDU. The intra-BSS PPDU indicates a PPDU sent from the same BSS as the BSS including the wireless communication terminal, and the inter-BSS PPDU indicates a PPDU sent from a BSS different from the BSS including the wireless communication terminal.

Description

[0001] This application is a divisional application of the patent application with application number 201780015247.2 (PCT / KR2017 / 002407), which was submitted to the China Patent Office on September 4, 2018, with an international application date of March 6, 2017, and the invention name is "Wireless communication method and wireless communication terminal in a basic service set overlapping with another basic service set". Technical Field

[0002] The present invention relates to a wireless communication method and a wireless communication terminal in the case where basic service sets overlap. Background Art

[0003] In recent years, as the supply of mobile devices has expanded, wireless communication technology that can provide fast wireless Internet services to mobile devices has significantly attracted public attention. Wireless communication technology allows mobile devices including smart phones, smart boards, laptops, portable multimedia players, embedded devices, etc. to access the Internet wirelessly in homes or companies or specific service provision areas.

[0004] One of the most famous wireless communication technologies is wireless LAN technology. Since the use of 2.4GHz frequency to support the initial wireless LAN technology, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 has been commercialized or developed various technical standards. First, IEEE 802.11b supports a maximum communication speed of 11Mbps when using the frequency of the 2.4GHz band. The IEEE 802.11a commercialized after IEEE802.11b uses a frequency of the 5GHz band instead of the 2.4GHz band, which reduces the impact of interference compared to the obviously congested frequency of the 2.4GHz band, and increases the communication speed by using orthogonal frequency division multiplexing (OFDM) technology until a maximum of 54Mbps. However, the reason why IEEE 802.11a has a disadvantage is that the communication distance is shorter than IEEE802.11b. Furthermore, IEEE 802.11g uses a frequency of 2.4 GHz band similarly to IEEE 802.11b to achieve a maximum communication speed of 54 Mbps and satisfy backward compatibility to be significantly noticed by the public, and further, is superior to IEEE 802.11a in terms of communication distance.

[0005] In addition, as a technical standard established to overcome the limitations of communication speed pointed out as a weakness in wireless LAN, IEEE 802.11n has been provided. IEEE 802.11n aims to improve the speed and reliability of the network and extend the working distance of the wireless network. In more detail, IEEE 802.11n supports high throughput (HT) with a data processing speed of up to 540Mbps or higher, and further, multiple input multiple output (MIMO) technology based on multiple antennas is used on both sides of the transmitting unit and the receiving unit to minimize transmission errors and optimize data speed. In addition, the standard can use a coding scheme that sends multiple copies overlapping each other to improve data reliability.

[0006] As the supply of wireless LANs is active and the applications using wireless LANs are further diversified, the need for new wireless LAN systems for supporting higher throughput (very high throughput (VHT)) than the data processing speed supported by IEEE 802.11n has attracted public attention. Among them, IEEE 802.11ac supports a wide bandwidth (80 to 160MHz) of 5GHz frequency. The IEEE 802.11ac standard is defined only in the 5GHz band, but the initial 11ac chipset will even support operations in the 2.4GHz band for backward compatibility with existing 2.4GHz band products. Theoretically, according to the standard, the wireless LAN speed of multiple stations can reach a maximum of 1Gbps and the maximum single link speed can reach a maximum of 500Mbps. This is achieved by expanding the concept of the wireless interface accepted by 802.11n, such as a wider wireless frequency bandwidth (maximum 160MHz), more MIMO spatial streams (maximum 8), multi-user MIMO and high-density modulation (maximum 256QAM). In addition, as a scheme for transmitting data by using the 60 GHz band instead of the existing 2.4 GHz / 5 GHz, IEEE 802.11ad has been provided. IEEE 802.11ad is a transmission standard that provides a maximum speed of 7 Gbps by using a beamforming technology and is suitable for high-bitrate moving image streams such as massive data or non-compressed HD video. However, since the 60 GHz band is difficult to pass through obstacles, the disadvantage is that the 60 GHz band can be used only between devices in a short-distance space.

[0007] Meanwhile, in recent years, as the next generation wireless communication technology standard after 802.11ac and 802.11ad, discussions on providing high efficiency and high performance wireless communication technology in a high density environment are ongoing. That is, in the next generation wireless communication technology environment, it is necessary to provide communication with high frequency efficiency indoors / outdoors in the presence of high density terminals and basic terminals, and various technologies for realizing the communication are required.

[0008] In particular, as the number of devices using wireless communication technology increases, it is necessary to efficiently use a predetermined channel. Therefore, what is needed is a technology that can efficiently use bandwidth by simultaneously transmitting data between multiple terminals and a base terminal. Summary of the invention

[0009] Technical issues

[0010] The embodiments of the present invention are to provide a wireless communication method and a wireless communication terminal in a situation where basic service sets overlap.

[0011] Technical Solution

[0012] According to an embodiment of the present invention, a wireless communication terminal that communicates wirelessly includes: a transceiver; and a processor. The processor is configured to send a BSS color indicating a BSS including the wireless communication terminal when communicating with another wireless communication terminal through the transceiver, and send a predetermined value as the BSS color when the wireless communication terminal fails to receive information signaling the BSS color.

[0013] When the wireless communication terminal fails to make any association with the wireless communication terminal as the AP, the processor may transmit a predetermined value as the BSS color.

[0014] When the wireless communication terminal receives signaling information indicating that the operation based on the BSS color is not permitted, the processor may be configured to transmit a predetermined value as the BSS color.

[0015] The predetermined value may be 0.

[0016] A PLCP protocol data unit (PPDU) that signals a predetermined value as a BSS color may not be identified as an inter-BSS PPDU or an intra-BSS PPDU based on the BSS color as the predetermined value. The intra-BSS PPDU may indicate a PPDU sent from the same BSS as the BSS including the wireless communication terminal, while the inter-BSS PPDU may indicate a PPDU sent from a BSS other than the BSS including the wireless communication terminal.

[0017] According to an embodiment of the present invention, a wireless communication terminal that communicates wirelessly includes: a transceiver; and a processor. The processor is configured to receive a PLCP protocol data unit (PPDU) through the transceiver and access a channel based on whether the PPDU is an inter-BSS PPDU or an intra-BSS PPDU, wherein the intra-BSS PPDU indicates a PPDU sent from the same BSS as the BSS including the wireless communication terminal, and the inter-BSS PPDU indicates a PPDU sent from a BSS other than the BSS including the wireless communication terminal.

[0018] When a PPDU satisfies both the inter-BSS PPDU condition and the intra-BSS PPDU condition, the PPDU may be identified as an inter-BSS PPDU.

[0019] When the PPDU is not identified as an inter-BSS PPDU or an intra-BSS PPDU, the processor may set a basic network allocation vector (NAV) instead of an intra-BSS NAV based on the PPDU, may set the intra-BSS NAV based on a PPDU sent from the same BSS as the wireless communication terminal, and may set the basic NAV based on a PPDU sent from a BSS other than the BSS of the wireless communication terminal.

[0020] When the wireless communication terminal cannot identify whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color, the processor can be configured not to set the intra-BSS network allocation vector (NAV) based on the BSS color and the TXOP duration field of the HE-SIG-A field of the PPDU, but to set the intra-BSS NAV based on the PPDU sent from the same BSS as the BSS of the wireless communication terminal.

[0021] When signaling information indicating that BSS color-based operation is not allowed is received, the processor may be configured not to set the intra-BSS NAV based on the BSS color and the TXOP duration field of the HE-SIG-A field of the PPDU.

[0022] When the wireless communication terminal recognizes that the BSS color of the BSS including the wireless communication terminal is the same as the BSS color of another BSS, the intra-BSS NAV may not be set based on the BSS color and the TXOP duration field of the HE-SIG-A field of the PPDU.

[0023] When the wireless communication terminal cannot identify whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color, the processor may be configured not to enter the power saving mode based on the BSS color.

[0024] When the wireless communication terminal is an AP and the PPDU is a trigger-based PPDU transmitted from the wireless communication terminal which is not triggered by the wireless communication terminal, the processor may be configured to determine that the PPDU is an inter-BSS PPDU.

[0025] When the wireless communication terminal is an AP and the PPDU is a PPDU including a trigger frame, the processor may be configured to determine that the PPDU is an inter-BSS PPDU.

[0026] The processor may be configured to determine whether the PPDU includes a trigger frame based on information related to a spatial reuse (SR) operation included in the PPDU.

[0027] The processor may be configured to determine whether the PPDU includes a trigger frame based on information related to the SR operation included in the PPDU indicating whether the SR operation is restrictively allowed or the SR operation is delayed while the PPDU is being transmitted.

[0028] According to an embodiment of the present invention, a wireless communication terminal for wireless communication includes: a transceiver; and a processor. The processor is configured to receive a PLCP processing data unit (PPDU) through the transceiver, and not perform an operation based on the BSS color when the BSS color indicated by the PPDU is a predetermined value.

[0029] When the BSS color indicated by the PPDU is a predetermined value, the processor may not perform an SR operation for the PPDU.

[0030] When the BSS color indicated by the PPDU is a predetermined value, the processor may regard the PPDU as an intra-BSS PPDU.

[0031] The predetermined value may be a reserved value that is not used in the BSS color when the AP selects the BSS color.

[0032] Beneficial Effects

[0033] Embodiments of the present invention provide a wireless communication method and a wireless communication terminal in a situation where basic service sets overlap. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A wireless LAN system according to an embodiment of the present invention is shown.

[0035] Figure 2 A wireless LAN system according to another embodiment of the present invention is shown.

[0036] Figure 3 A block diagram illustrating a configuration of a station according to an embodiment of the inventive concept is shown.

[0037] Figure 4 A block diagram illustrating a configuration of an access point according to an embodiment of the present invention is shown.

[0038] Figure 5 The process of a station setting up an access point and a link according to an embodiment of the present invention is shown.

[0039] Figure 6 It is shown that the wireless communication terminal according to an embodiment of the present invention enters the power saving mode based on the BSS color.

[0040] Figure 7 It is shown that the wireless communication terminal according to an embodiment of the present invention enters the power saving mode during the inter-BSS color conflict.

[0041] Figure 8 An operation of setting the NAV by the wireless communication terminal according to an embodiment of the present invention when a BSS color conflict occurs is shown.

[0042] Fig. 9 A NAV setting operation of a wireless communication terminal according to another embodiment of the present invention is shown when a BSS color conflict occurs.

[0043] Fig.10 An operation of a wireless communication terminal according to an embodiment of the present invention determining whether to reset NAV based on a CF-End frame when a BSS color conflict occurs is shown.

[0044] Fig.11 The operation of a wireless communication terminal according to another embodiment of the present invention to determine whether to reset the NAV based on the CF-End frame when a BSS color conflict occurs is shown.

[0045] Fig.12 The operation of the wireless communication terminal according to the embodiment of the present invention to recognize the BSS color conflict is shown.

[0046] Fig.13 MAC frame formats of a Clear to Send (CTS) frame and an ACK frame according to an embodiment of the present invention are shown.

[0047] Fig.14 An operation of a wireless communication terminal setting NAV based on an RTS frame and a CTS frame according to an embodiment of the present invention is shown.

[0048] Fig.15 The format of an 802.11a PPDU according to an embodiment of the present invention is shown.

[0049] Fig.16 The format of the service field of the PPDU according to an embodiment of the present invention is shown.

[0050] Fig.17 The wireless communication terminal according to the embodiment of the present invention is shown Figure 15 to Figure 16 An embodiment of the present invention is used to set the operation of NAV.

[0051] Fig.18 A method of setting a partial AID and group ID field of a VHT-SIG-A by a wireless communication terminal according to an embodiment of the present invention is shown.

[0052] Fig.19 A method of determining whether a corresponding PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on whether a PPDU received by a wireless communication terminal is a downlink PPDU according to an embodiment of the present invention is illustrated.

[0053] Fig. 20A method for a wireless communication terminal according to an embodiment of the present invention to identify whether a received MAC frame is an intra-BSS frame or an inter-BSS frame based on SR-related information is shown.

[0054] Fig.21 A method is shown in which, when a PPDU received by a wireless communication terminal according to an embodiment of the present invention satisfies both an inter-BSS PPDU condition and an intra-BSS PPDU condition, the wireless communication terminal determines whether the corresponding PPDU is an inter-BSS PPDU or an intra-BSS PPDU.

[0055] Fig. 22 A case where a wireless communication terminal according to an embodiment of the present invention enters a power saving state based on a MAC header of a frame received by the wireless communication terminal is shown.

[0056] Fig.23 A case is shown in which a wireless communication terminal enters a power saving state based on a MAC header of a frame received by the wireless communication terminal when the wireless communication terminal according to an embodiment of the present invention is included in a BSS corresponding to a multiple BSSID set.

[0057] Fig.24 The format of the HE-SIG-B field according to an embodiment of the present invention is shown.

[0058] Fig.25 is a view illustrating a MAC frame format according to an embodiment of the present invention.

[0059] Fig.26 is a view illustrating a variation of an HT Control field according to an embodiment of the present invention.

[0060] Fig. 27 The format of the A-Control subfield according to an embodiment of the present invention is shown.

[0061] Fig.28 FIG. 2 shows a format of an A-Control subfield of a control subfield according to another embodiment of the present invention.

[0062] Figure 29 to Figure 33 The frame format and HE variant format of the HT Control field according to another embodiment of the present invention are shown.

[0063] Fig.34 The format of a trigger frame according to an embodiment of the present invention is shown.

[0064] Fig.35 The formats of the common information field and the per-user information field of the trigger frame according to an embodiment of the present invention are shown.

[0065] Fig.36The common information field and the per-user information field of the trigger frame according to another embodiment of the present invention are shown.

[0066] Fig.37 The trigger-related common information field and the trigger-related per-user information field of the MU-BAR type trigger frame according to an embodiment of the present invention are shown.

[0067] Fig.38 The format of the trigger-related common information field of the MU-BAR type trigger frame according to an embodiment of the present invention is shown.

[0068] Fig.39 A format of a MU-BAR type trigger frame for GCR according to an embodiment of the present invention is shown.

[0069] Fig.40 A format of a MU-BAR type trigger frame for GCR according to an embodiment of the present invention is shown.

[0070] Fig.41 The format of the BAR control field and the encoded values ​​of the BlockACKReq variant according to an embodiment of the present invention are shown.

[0071] Fig.42 The format of the BAR information field according to an embodiment of the present invention is shown.

[0072] Fig.43 A BAR information field according to another embodiment of the present invention is shown.

[0073] Fig.44 A trigger frame structure according to another embodiment of the present invention is shown.

[0074] Fig.45 The operation of the wireless communication terminal according to the embodiment of the present invention is shown. DETAILED DESCRIPTION

[0075] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. However, the present invention can be specifically implemented in different forms and should not be constructed to be limited to the embodiments set forth herein. Parts that are irrelevant to the description are omitted in the accompanying drawings in order to clearly describe the present invention, and similar reference numerals refer to similar elements from beginning to end.

[0076] Furthermore, when it is described that a thing includes (or contains or has) some elements, it should be understood that, without specific limitations, it may include (or contain or have) only those elements, or it may include (or contain or have) other elements as well as those elements.

[0077] This application claims priority to and the benefit of Korean Patent Applications No. 10-2016-0026684 (March 4, 2016), No. 10-2016-0029975 (March 12, 2016), No. 10-2016-0044465 (April 11, 2016), No. 10-2016-0057597 (May 11, 2016), and No. 10-2016-0114821 (September 7, 2016) filed in the Korean Intellectual Property Office, and the embodiments and items mentioned in the corresponding applications are included in the detailed description of this application.

[0078] Figure 1 1 is a diagram illustrating a wireless communication system according to an embodiment of the present invention. For the convenience of description, the embodiment of the present invention is described through a wireless LAN system. The wireless LAN system includes one or more basic service sets (BSSs) and the BSS represents a collection of devices that are successfully synchronized with each other to communicate with each other. In general, the BSS can be classified into an infrastructure BSS and an independent BSS (IBSS) and Figure 1 The diagram shows the infrastructure BSS between them.

[0079] like Figure 1 As illustrated in the figure, the infrastructure BSS (BSS1 and BSS2) includes one or more stations STA1, STA2, STA3, STA4 and STA5, access points PCP / AP-1 and PCP / AP-2 as stations providing distribution services, and a distribution system (DS) connecting multiple access points PCP / AP-1 and PCP / AP-2.

[0080] A station (STA) is a predetermined device including a medium access control (MAC) and a physical layer interface for a wireless medium that follows the procedures of the IEEE 802.11 standard, and includes a non-access point (non-AP) station and an access point (AP) in a broad sense. In addition, in this specification, the term "terminal" may be used to refer to the concept of a wireless LAN communication device including a non-AP STA or AP or both terms. A station for wireless communication includes a processor and a transceiver, and according to this embodiment, may further include a user interface unit and a display unit. The processor may generate a frame to be sent through a wireless network or process a frame received through a wireless network, and further, perform various processes for controlling the station. In addition, the transceiver is functionally connected to the processor and sends and receives frames through a wireless network for a station.

[0081] An access point (AP) is an entity that provides access to a distribution system (DS) for stations associated therewith via a wireless medium. In an infrastructure BSS, communication between non-AP stations is performed via an AP in principle, but when a direct link is configured, direct communication can be achieved even between non-AP stations. Meanwhile, in the present invention, AP is used as a concept including a personal BSS coordination point (PCP) and may include concepts including a centralized controller, a base station (BS), a node B, a base transceiver system (BTS), and a site controller in a broad sense.

[0082] Multiple infrastructure BSSs may be connected to each other through a distribution system (DS). In this case, the multiple BSSs connected through the distribution system are referred to as an extended service set (ESS).

[0083] Figure 2 The figure shows an independent BSS as a wireless communication system according to another embodiment of the present invention. For the convenience of description, another embodiment of the present invention is described by a wireless LAN system. Figure 2 In the embodiment of Figure 1 The same or corresponding parts of the embodiments are described repeatedly.

[0084] because Figure 2 The BSS3 shown in FIG. 1 is an independent BSS and does not include an AP, so all stations STA6 and STA7 are not connected to the AP. An independent BSS is not allowed to access the distribution system and form a complete network. In an independent BSS, corresponding stations STA6 and STA7 can be directly connected to each other.

[0085] Figure 3 is a block diagram illustrating a configuration of a station 100 according to an embodiment of the present invention.

[0086] like Figure 3 As illustrated in FIG. 1 , the station 100 according to an embodiment of the present invention may include a processor 110 , a transceiver 120 , a user interface unit 140 , a display unit 150 , and a memory 160 .

[0087] First, the transceiver 120 transmits and receives wireless signals such as wireless LAN physical layer frames and can be embedded in the station 100 or set to the outside. According to the embodiment, the transceiver 120 may include at least one transmission and reception module using different frequency bands. For example, the transceiver 120 may include transmission and reception modules with different frequency bands such as 2.4GHz, 5GHz and 60GHz. According to the embodiment, the station 100 may include a transmission and reception module using a frequency band of 6GHz or higher and a transmission and reception module using a frequency band of 6GHz or lower. The corresponding transmission and reception module can perform wireless communication with an AP or an external station according to the wireless LAN standard of the frequency band supported by the corresponding transmission and reception module. The transceiver 120 can operate only one transmission and reception module at a time or operate multiple transmission and reception modules simultaneously together according to the performance and requirements of the station 100. When the station 100 includes multiple transmission and reception modules, each transmission and reception module can be implemented by an independent element or multiple modules can be integrated into one chip.

[0088] Next, the user interface unit 140 includes various types of input / output devices provided in the station 100. That is, the user interface unit 140 may receive a user input by using various input devices and the processor 110 may control the station 100 based on the received user input. In addition, the user interface unit 140 may perform an output based on a command of the processor 110 by using various output devices.

[0089] Next, the display unit 150 outputs an image on the display screen. The display unit 150 may output various display objects such as content or a user interface executed by the processor 110 based on a control command of the processor 110 or the like. In addition, the memory 160 stores a control program used in the station 100 and various resulting data. The control program may include an access program required for the station 100 to access an AP or an external station.

[0090] The processor 110 of the present invention may execute various commands or programs and process data in the station 100. In addition, the processor 110 may control the corresponding units of the station 100 and control data transmission / reception between these units. According to an embodiment of the present invention, the processor 110 may execute a program for accessing an AP stored in the memory 160 and receive a communication configuration message sent by the AP. In addition, the processor 110 may read information about the priority condition of the station 100 included in the communication configuration message and request access to the AP based on the information about the priority condition of the station 100. The processor 110 of the present invention may represent a main control unit of the station 100 and according to this embodiment, the processor 110 may represent a control unit for individually controlling a certain component (e.g., transceiver 120, etc.) of the station 100. The processor 110 may be a modulator and / or demodulator that modulates a wireless signal sent to the transceiver 120 and demodulates a wireless signal received from the transceiver 120. The processor 110 controls various operations of wireless signal transmission / reception of the station 100 according to an embodiment of the present invention. A detailed embodiment thereof will be described below.

[0091] Figure 3 The station 100 illustrated in is a block diagram according to an embodiment of the present invention, in which individual blocks are illustrated as logically distinct elements of the device. Therefore, the elements of the device can be installed in a single chip or multiple chips depending on the design of the device. For example, the processor 110 and the transceiver 120 can be integrated into a single chip or implemented as separate chips. In addition, in an embodiment of the present invention, some components of the station 100, such as the user interface unit 140 and the display unit 150, can be optionally set in the station 100.

[0092] Figure 4 is a block diagram illustrating a configuration of an AP 200 according to an embodiment of the present invention.

[0093] like Figure 4 As shown in FIG. 2 , the AP 200 according to an embodiment of the present invention may include a processor 210, a transceiver 220, and a memory 260. Figure 4 In the AP 200, the components of Figure 2 Description of the same or corresponding parts of the components of the station 100 are repeated.

[0094] refer to Figure 4 , the AP 200 according to the present invention includes a transceiver 220 for operating a BSS in at least one frequency band. Figure 3As described in the embodiment of the present invention, the transceiver 220 of the AP 200 may also include a plurality of transmission and reception modules using different frequency bands. That is, the AP 200 according to the embodiment of the present invention may include two or more transmission and reception modules among different frequency bands (e.g., 2.4 GHz, 5 GHz, and 60 GHz) together. Preferably, the AP 200 may include a transmission and reception module using a 6 GHz or higher frequency band and a transmission and reception module using a 6 GHz or lower frequency band. The corresponding transmission and reception modules may perform wireless communication with the station according to the wireless LAN standard of the frequency band supported by the corresponding transmission and reception modules. The transceiver 220 may operate only one transmission and reception module at a time or operate a plurality of transmission and reception modules simultaneously together according to the performance and requirements of the AP 200.

[0095] Next, the memory 260 stores the control program used in the AP 200 and various resulting data. The control program may include an access program for managing the access of the station. In addition, the processor 210 may control the corresponding units of the AP 200 and control the data transmission / reception between these units. According to an embodiment of the present invention, the processor 210 may execute a program for accessing the station stored in the memory 260 and send a communication configuration message for one or more stations. In this case, the communication configuration message may include information about the access priority condition of the corresponding station. In addition, the processor 210 performs access configuration according to the access request of the station. The processor 210 may be a modulator and / or demodulator that modulates the wireless signal sent to the transceiver 220 and demodulates the wireless signal received from the transceiver 220. The processor 210 controls various operations such as the radio signal transmission / reception of the AP 200 according to the first embodiment of the present invention. Its detailed embodiment will be described below.

[0096] Figure 5 is a diagram schematically illustrating a process in which a STA sets up a link with an AP.

[0097] refer to Figure 5 , the link between the STA 100 and the AP 200 is generally set up through three steps of scanning, authentication, and association. First, the scanning step is a step in which the STA 100 obtains access information of the BSS operated by the AP 200. Methods for performing scanning include a passive scanning method in which the AP 200 obtains information by using a beacon message (S101) transmitted periodically and an active scanning method in which the STA 100 transmits a probe request to the AP (S103) and obtains access information by receiving a probe response (S105) from the AP.

[0098] The STA 100 that successfully receives the wireless access information in the scanning step performs an authentication step by sending an authentication request (S107a) and receiving an authentication response (S107b) from the AP 200. After the authentication step is performed, the STA 100 performs an association step by sending an association request (S109a) and receiving an association response (S109b) from the AP 200.

[0099] At the same time, an authentication step (S111) based on 802.1X and an IP address acquisition step (S113) through DHCP may be additionally performed. Figure 5 In the example, the authentication server 300 is a server that processes 802.1X-based authentication for the STA 100 and may exist in physical association with the AP 200 or as a separate server.

[0100] In a specific embodiment, the AP 200 may be a wireless communication terminal that allocates communication medium resources and performs scheduling in an independent network (such as an ad hoc network) that is not connected to an external distribution service. In addition, the AP 200 may be at least one of a base station, an eNB, and a transmission point TP.

[0101] Due to the popularity of mobile devices and the supply of wireless communications, wireless communication terminals are increasingly communicating in dense environments. In particular, the number of situations in which wireless communication terminals communicate in an environment where multiple BSSs overlap is increasing. When multiple BSSs overlap, the communication efficiency of the wireless communication terminal may be degraded due to interference with other wireless communication terminals. In particular, when the frequency band is used through a competition process, the wireless communication terminal may not even be able to guarantee a transmission opportunity due to interference with other wireless communication terminals. In order to solve this problem, the wireless communication terminal may perform a spatial reuse (SR) operation. Specifically, the SR operation may include an operation to access a channel based on whether the received frame is a MAC frame sent from a BSS including the wireless communication terminal or a MAC frame sent from another BSS. For the convenience of description, when a frame is used in the following description without any description, it is assumed to refer to a MAC frame.

[0102] In a specific embodiment, the operation of accessing the channel may include setting NAV and resetting NAV operations, CCA operations, and deferring operations. For example, the wireless communication terminal may adjust a clear channel assessment (CCA) threshold according to whether a frame received by the wireless communication terminal is a frame transmitted from a BSS including the wireless communication terminal or a frame transmitted from an OBSS. In addition, the wireless communication terminal may adjust the transmission power of the PPDU to be transmitted according to the CCA threshold adjustment during the SR operation.

[0103] Specifically, the wireless communication terminal may apply the CCA threshold value according to whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU while the received PPDU is being sent. In a specific embodiment, the CCA threshold value may be applied according to whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU while the payload of the received PPDU is being sent. In addition, the wireless communication terminal may receive the first PPDU and receive the second PPDU while applying the CCA threshold value according to whether the first PPDU is an inter-BSS PPDU or an intra-BSS PPDU. Specifically, the wireless communication terminal may apply the CCA threshold value according to whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU while the received PPDU is being sent. Specifically, when the wireless communication terminal receives an inter-BSS PPDU and applies the CCA threshold value corresponding to the inter-BSS PPDU, it may receive the intra-BSS PPDU. At this time, the wireless communication terminal may apply the CCA threshold value corresponding to the intra-BSS PPDU instead of the CCA threshold value corresponding to the inter-BSS PPDU. However, when the wireless communication terminal receives the intra-BSS PPDU and applies the CCA threshold corresponding to the intra-BSS PPDU, the wireless communication terminal may receive the inter-BSS PPDU when the transmission of the intra-BSS PPDU is not completed. At this time, the wireless communication terminal may maintain the CCA threshold corresponding to the intra-BSS PPDU until the transmission of the intra-BSS PPDU is completed. Specifically, the wireless communication terminal may not apply the CCA threshold corresponding to the inter-BSS PPDU until the transmission of the intra-BSS PPDU is completed. In the above operation, the CCA threshold corresponding to the inter-BSS PPDU may be equal to or greater than the CCA threshold corresponding to the intra-BSS PPDU.

[0104] In addition, the wireless communication terminal may enter the power saving mode according to whether a frame received by the wireless communication terminal is a frame transmitted from the BSS including the wireless communication terminal or a frame transmitted from the OBSS.

[0105] For the convenience of explanation, a BSS including a wireless communication terminal is referred to as intra-BSS, and a basic service set overlapping with intra-BSS is referred to as an overlapping basic service set (OBSS). In addition, a BSS different from intra-BSS is referred to as inter-BSS. In addition, a frame sent within a BSS is referred to as an intra-BSS frame, and a frame sent in an OBSS is referred to as an OBSS frame or an inter-BSS frame. In addition, a PPDU sent from within a BSS is referred to as an intra-BSS PPDU, and a PPDU sent from an OBSS is referred to as an OBSS PPDU or an inter-BSS PPDU.

[0106] Figure 6 It is shown that the wireless communication terminal according to an embodiment of the present invention enters the power saving mode based on the BSS color.

[0107] When the recipient of the PPDU sent within the BSS does not include a non-AP wireless communication terminal, the non-AP wireless communication terminal can enter a power saving mode. Specifically, the non-AP wireless communication terminal can enter a power saving mode under the following conditions. When the PPDU received by the non-AP wireless communication terminal is a HE-MU-PPDU, the BSS color value signaled by the corresponding PPDU indicates the BSS associated with the wireless communication terminal, the corresponding PPDU is not an uplink PPDU, the non-AP wireless communication terminal is not included in the address of the receiving wireless communication terminal signaled by the PPDU, and it is not a broadcast address indicating a non-AP wireless communication terminal, the non-AP wireless communication terminal can enter a power saving mode. In addition, when the PPDU received by the non-AP wireless communication terminal is any one of a HE-MU-PPDU, a HE-SU-PPDU, and a HE extended range SU-PPDU, the BSS color value signaled by the corresponding PPDU indicates the BSS associated with the non-AP wireless communication terminal, and the corresponding PPDU is an uplink PPDU, the non-AP wireless communication terminal can enter a power saving mode. In addition, when the PPDU received by the non-AP wireless communication terminal is a triggered PPDU and the BSS color value signaled by the PPDU indicates the BSS associated with the non-AP wireless communication terminal, the non-AP wireless communication terminal can enter the power saving mode. In a specific embodiment, the non-AP wireless communication terminal can determine whether the PPDU is a PPDU for uplink transmission based on the UL_FLAG value of RXVECTOR. In addition, the non-AP wireless communication terminal can determine whether the wireless communication terminal is included in the address of the receiving wireless communication terminal signaled by the PPDU based on the STA_ID_LIST of RXVECTOR. In addition, the non-AP wireless communication terminal can leave the power saving mode when the corresponding PPDU is not sent. At this time, RXVECTOR is a parameter set indicating the information of the PPDU received from the module of the physical layer by the module of the MAC layer when the wireless communication terminal receives the PPDU.

[0108] In addition, the non-AP wireless communication terminal may determine that the wireless medium is busy in the power saving state. Therefore, the wireless communication terminal does not access the wireless medium in the power saving state. In addition, the non-AP wireless communication terminal may operate the network allocation vector (NAV) timer in the power saving mode and access the wireless medium when the NAV timer expires. In addition, when the power saving mode option of the non-AP wireless communication terminal is activated and the current state of the non-AP wireless communication terminal is not in the power saving mode, the non-AP wireless communication terminal may enter the power saving mode. At this time, the state in which the power saving mode option is activated may be the case where the value of dot11IntraPPDUPowerSaveOptionActivated is True. In addition, the power saving mode is referred to as the sleep state, and the state that is not the power saving mode may be referred to as the wake-up state.

[0109] exist Figure 6 In an embodiment of the present invention, the station STA detects a PPDU that signals a BSS color that is the same as the BSS color of the BSS including the station. At this time, the station STA identifies the detected PPDU as an intra-BSS PPDU based on the BSS color. Therefore, the station STA can enter the power saving mode. Specifically, when at least one of the above conditions is met, the station STA can enter the power saving mode. In addition, the station STA leaves the power saving mode when the transmission of the corresponding PPDU is terminated.

[0110] Since the size of the field indicating the BSS color is limited, different BSSs may be set to the same BSS color. For convenience of description, the case where different BSSs correspond to the same BSS color is called inter-BSS color conflict or BSS color conflict.

[0111] Figure 7 It is shown that the wireless communication terminal according to an embodiment of the present invention enters the power saving mode during the inter-BSS color conflict.

[0112] When an inter-BSS color conflict occurs and the non-AP wireless communication terminal receives an inter-BSS PPDU that signals an inter-BSS color that is the same as the BSS color of the BSS associated with the non-AP wireless communication terminal, the non-AP wireless communication terminal may enter a power saving mode. Figure 7 In the embodiment of the present invention, the PPDU sent by the AP associated with the non-AP wireless communication terminal is not received. In this case, the BSS color signaled by the PPDU may be the BSS color signaled by the BSS color field of the PPDU. Specifically, the BSS color signaled by the PPDU may be the BSS color signaled by the BSS color field of the HE-SIG-A of the PPDU.

[0113] Therefore, when the wireless communication terminal cannot identify the BSS to which the corresponding PPDU is sent based on the BSS color signaled through the PPDU, the wireless communication terminal may not perform operations based on the BSS color. Specifically, when the wireless communication terminal cannot identify the BSS based on the BSS color signaled through the PPDU, the wireless communication terminal may not perform operations based on the BSS color that is the same as the BSS color between BSSs. For example, when the wireless communication terminal cannot identify the BSS based on the BSS color signaled through the PPDU, even when the wireless communication terminal receives a PPDU indicating a BSS color that is the same as the BSS color between BSSs, the wireless communication terminal may not regard the PPDU as an inter-BSS PPDU.

[0114] When the non-AP wireless communication terminal cannot identify whether the PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on the BSS color signaled by the PPDU, the non-AP wireless communication terminal may not enter the power saving mode based on the BSS color signaled by the PPDU. Specifically, when the non-AP wireless communication terminal identifies a BSS color conflict, the non-AP wireless communication terminal may not enter the power saving mode based on the BSS color signaled by the PPDU. In a specific embodiment, from the time when the BSS color conflict is identified to a predetermined time point, the non-AP wireless communication terminal may not enter the power saving mode based on the BSS color value. In another specific embodiment, from the time when the BSS color conflict is identified to a predetermined time point, the non-AP wireless communication terminal may not operate in the intra-PPDU power saving mode based on the BSS color value. In addition, the predetermined time point may indicate the time point when the BSS color conflict is resolved. In another specific embodiment, the predetermined time point may be the time point when the association between the AP and the non-AP wireless communication terminal is disassociated. In another specific embodiment, the non-AP wireless communication terminal may stop entering the power saving mode from the time when the non-AP wireless communication terminal detects the BSS color conflict.

[0115] In addition, when the wireless communication terminal cannot identify whether the PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on the BSS color signaled by the PPDU, the wireless communication terminal may not set the NAV based on the BSS color. Specifically, when the wireless communication terminal cannot identify whether the PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on the BSS color signaled by the PPDU, the wireless communication terminal may not set the intra-BSS NAV based on the BSS color and TXOP duration field of the HE-SIG-A field. First, the operation of setting two NAVs by the wireless communication terminal will be described, and the method of setting the NAV by the wireless communication terminal when the wireless communication terminal cannot identify whether the PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on the BSS color signaled by the PPDU will be described.

[0116] The wireless communication terminal can maintain two NAVs, namely, the intra-BSS NAV set based on the PPDU identified as the intra-BSS PPDU and the basic NAV set based on the PPDU identified as the inter-BSS PPDU. At this time, the wireless communication terminal can set the basic NAV based on the PPDU that may not be identified as the inter-BSS PPDU or the intra-BSS PPDU. Specifically, the wireless communication terminal can maintain the two NAVs through the following operations.

[0117] When the wireless communication terminal receives at least one valid frame from the PSDU and identifies the frame as an intra-BSS frame, the wireless communication terminal can set the intra-BSS NAV based on the valid duration field value of the PSDU. In addition, when the wireless communication terminal receives at least one valid frame from the PSDU and identifies the frame as an inter-BSS frame, the wireless communication terminal can set the basic NAV based on the valid duration field value of the PSDU. In addition, when the wireless communication terminal receives at least one valid frame from the PSDU and may not determine the frame as an intra-BSS frame or an inter-BSS frame, the wireless communication terminal can set the basic NAV based on the valid duration field value of the PSDU.

[0118] The wireless communication terminal receives a signaling field of a PPDU including BSS identification information from a PPDU, and the wireless communication terminal can set two NAVs based on the BSS identification information signaled by the signaling field of the PPDU. At this time, the PPDU can be a HE-PPDU, and the signaling field of the PPDU can be a HE-SIG-A field. In addition, the BSS identification information can be a BSS color. In addition, the wireless communication terminal can set the NAV based on the TXOP duration field of the HE-SIG-A field. Specifically, when the wireless communication terminal receives a signaling field of a PPDU including BSS identification information from a PPDU and the BSS identification information signaled by the signaling field of the PPDU is identified as within the BSS, the wireless communication terminal can set the BSS intra-NAV based on the signaling field of the PPDU. In addition, when the wireless communication terminal receives a signaling field of a PPDU including BSS identification information from a PPDU, and the BSS identification information signaled by the signaling field of the PPDU is identified as between BSSs, the wireless communication terminal can set the basic NAV based on the signaling field of the PPDU.

[0119] When the receiver address RA of the frame received by the wireless communication terminal is the same as the MAC address of the wireless communication terminal, the wireless communication terminal may not set the intra-BSS NAV or the basic NAV according to the duration field of the corresponding frame. In addition, when the wireless communication terminal receives a valid signaling field of the PPDU from the PPDU and receives a valid PSDU from the corresponding PPDU, the wireless communication terminal may not set the intra-BSS NAV or the basic NAV based on the TXOP duration field in the signaling field including the corresponding PPDU.

[0120] When the value of the duration field of a frame recognized by the wireless communication terminal as an intra-BSS frame is greater than the value of the current intra-BSS NAV, the wireless communication terminal can set the intra-BSS NAV based on the value of the duration field of the frame. When the value of the duration field of a frame that the wireless communication terminal cannot recognize as an intra-BSS frame or an inter-BSS frame is greater than the value of the current basic NAV, the wireless communication terminal can set the basic NAV based on the value of the duration field of the frame.

[0121] When the value of the TXOP duration field of the signaling field of the PPDU identified as the intra-BSS PPDU by the wireless communication terminal is greater than the value of the current intra-BSS NAV, the wireless communication terminal can set the intra-BSS NAV based on the TXOP duration field value of the signaling field of the PPDU identified as the intra-BSS PPDU. In addition, when the value of the TXOP duration field of the signaling field of the PPDU identified as the inter-BSS PPDU by the wireless communication terminal is greater than the value of the current basic NAV, the wireless communication terminal can set the basic NAV based on the TXOP duration field value of the signaling field of the corresponding PPDU.

[0122] When the wireless communication terminal receives the CF-End frame, the wireless communication terminal may reset the NAV. At this time, the wireless communication terminal may determine whether to reset the NAV according to the BSS from which the CF-End frame is sent. Specifically, when the BSS from which the PPDU for setting the currently set NAV is sent and the BSS from which the CF-End frame is sent are the same, the wireless communication terminal may reset the currently set NAV. Additionally, when the BSS from which the PPDU for setting the currently set NAV is sent and the BSS from which the CF-End frame is sent are different, the wireless communication terminal may not reset the NAV. In a specific embodiment, when the wireless communication terminal receives the CF-End frame from a BSS that does not correspond to the BSS indicated by the multi-BSSID set including the inter-BSS or the BSSID within the BSS, and sets the most recent NAV by a PPDU sent from any one of the BSSs indicated by the multi-BSSID set including the intra-BSS or the BSSID within the BSS, the wireless communication terminal may not reset the NAV. In another specific embodiment, when the wireless communication terminal receives a CF-End frame from a BSS that is one of the BSSs indicated by a set of multiple BSSIDs including an intra-BSS or an intra-BSS BSS, and the most recent NAV is set by a PPDU that does not correspond to the BSS indicated by a set of multiple BSSIDs including an inter-BSS or an intra-BSS BSS BSS, the wireless communication terminal may not reset the NAV.

[0123] The trigger frame sent by the AP may trigger uplink transmission of the wireless communication terminal that receives the trigger frame. At this time, according to a certain condition, the wireless communication terminal may start UL MU transmission based on the trigger frame without considering NAV. Specifically, when the NAV is set by a frame sent by the AP that sent the trigger frame, the wireless communication terminal may start UL MU transmission based on the trigger frame without considering NAV. In addition, when the response to be sent by the wireless communication terminal includes an ACK frame or a block ACK frame and the duration of the triggered PPDU is less than a predetermined value, the wireless communication terminal may start UL MU transmission based on the trigger frame without considering NAV. In addition, when the NAV is set by a frame sent by another wireless communication terminal included in the BSS, the wireless communication terminal may start UL MU transmission based on the trigger frame without considering NAV. In addition, when the field indicating whether channel sensing is required of the trigger frame indicates that channel sensing is not required, the wireless communication terminal may start UL MU transmission based on the trigger frame without considering NAV. Specifically, the field indicating whether the trigger frame requires channel sensing may be a CS required field.

[0124] However, when NAV is set as in the above-described embodiment, BSS color conflict may occur. NAV setting and transmission operation of the wireless communication terminal may be a problem. Figures 8 to 9 Describe this.

[0125] Figure 8 An operation of setting the NAV by the wireless communication terminal according to an embodiment of the present invention when a BSS color conflict occurs is shown.

[0126] exist Figure 8 In an embodiment, the BSS color of the first BSS BSS1 including the first station STA1 and the BSS color of the second BSS BSS2 including the second station STA2 and the third station STA3 are the same. The first station STA1 receives the inter-BSS frame sent by the second station STA2 included in the first BSS BSS1. At this time, the station STA identifies the inter-BSS frame as an intra-BSS frame based on the BSS color indicated by the HE-SIG-A field of the PPDU including the inter-BSS frame. The first station STA1 sets the intra-BSS NAV according to the value of the TXOP duration field of the signaling field of the PPDU including the inter-BSS frame. Then, the first station STA1 receives a trigger frame from the intra-BSS AP within the BSS. As described above, when the NAV is set by a frame sent by another wireless communication terminal included in the BSS, the wireless communication terminal can start UL MU transmission based on the trigger frame without considering the NAV. Therefore, the first station STA1 can start uplink transmission based on the trigger frame sent by the AP of the first BSS BSS1. At this time, because a frame is being transmitted from the third station STA3 to the second station STA2, interference occurs in the second BSS BSS2 due to a UL frame based on the trigger based on the trigger frame transmitted by the first station STA1. Therefore, a method of operating a wireless communication terminal capable of minimizing the influence of a BSS color conflict when a BSS color conflict occurs is required. For example, Figure 8 In the embodiment of FIG. 1 , when the first station STA1 sets the basic NAV instead of the intra-BSS NAV based on the frame transmitted by the second station STA2 , interference occurring in the second BSS BSS2 by transmission of the first station STA1 can be prevented. Fig. 9 Describe this.

[0127] Fig. 9 A NAV setting operation of a wireless communication terminal according to another embodiment of the present invention is shown when a BSS color conflict occurs.

[0128] When the wireless communication terminal cannot identify whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU, the wireless communication terminal may not set the intra-BSS NAV based on the TXOP duration field indicated by the signaling field of the PPDU. As described above, the BSS color signaled by the PPDU may be the BSS color signaled by the BSS color field of the PPDU. Specifically, the BSS color signaled by the PPDU may be the BSS color signaled by the BSS color field of the HE-SIG-A of the PPDU. Specifically, when the wireless communication terminal may not be sure whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU, the wireless communication terminal can identify a BSS color conflict. In addition, when the wireless communication terminal cannot identify whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU and other parameters and other conditions of the RXVECTOR, the wireless communication terminal may not set the intra-BSS NAV based on the TXOP duration field indicated by the signaling field of the PPDU. In a specific embodiment, when the wireless communication terminal cannot identify whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU, the wireless communication terminal may set the basic NAV based on the TXOP duration field indicated by the signaling field of the PPDU. At this time, when the wireless communication terminal cannot identify whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU and other parameters and other conditions of the RXVECTOR, the wireless communication terminal may set the basic NAV based on the TXOP duration field indicated by the signaling field of the PPDU. That is, when the wireless communication terminal cannot identify whether the received PPDU is an intra-BSS PPDU or an inter-BSS PPDU, the wireless communication terminal can set the basic NAV based on the PPDU. Specifically, when the PPDU received by the wireless communication terminal may not be identified as an intra-BSS PPDU or an inter-BSS PPDU, the wireless communication terminal can set the basic NAV based on the TXOP duration field of the corresponding PPDU. At this time, the TXOP duration field of the PPDU can be the TXOP duration field of the HE-SIG-A field.

[0129] In addition, when the wireless communication terminal cannot identify whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU, but can identify whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on other parameters and other conditions of the RXVECTOR, the wireless communication terminal can set the intra-BSS NAV or the basic NAV based on other parameters or other conditions of the RXVECTOR. The case where the corresponding PPDU is not identified as an intra-BSS PPDU or an inter-BSS PPDU based on other parameters and other conditions of the RXVECTOR may include the following case: the MAC frame included in the PPDU is not decoded. In addition, the case where the corresponding PPDU is not identified as an intra-BSS PPDU or an inter-BSS PPDU based on other parameters and other conditions of the RXVECTOR may include the following case: at least one of the corresponding PPDUs in the format and use of the PPDU is not identified as an intra-BSS PPDU or an inter-BSS PPDU. Through these embodiments, the wireless communication terminal can prevent interference with transmission in the OBSS that may occur with BSS color conflicts.

[0130] exist Fig. 9 In the embodiment, the BSS color of the first BSS BSS1 including the first station STA1 and the BSS color of the second BSS BSS2 including the second station STA2 and the third station STA3 are the same. At this time, the first station STA1 may determine whether the PPDU may not be identified as an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the HE-SIG-A field of the PPDU. For example, the first station STA1 may determine that a BSS color conflict occurs. The first station STA1 receives an inter-BSS frame sent by the second station STA2 included in the first BSS BSS1. However, because the first station STA1 may not be able to identify whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU, the first station STA1 sets a basic NAV. Therefore, because the basic NAV is set even when the first station STA1 receives a trigger frame from the AP of the first BSS BSS1, the first station STA1 does not start uplink transmission based on the trigger.

[0131] As described above, when the wireless communication terminal maintains two NAVs, the wireless communication terminal can reset the NAV according to the BSS that sends the CF-End frame and the BSS that sends the frame that sets the NAV. Therefore, when a BSS color conflict occurs, the operation of the wireless communication terminal may be problematic when resetting the NAV through the CF-End frame. Fig.10 and Fig.11 Describe this.

[0132] Fig.10 The operation of the wireless communication terminal according to the embodiment of the present invention to determine whether to reset the NAV based on the CF-End frame when a BSS color conflict occurs is shown.

[0133] exist Fig.10 In the embodiment of the present invention, the first station STA1 and the second station STA2 are included in the first BSS BSS1. The third station STA3 is included in the second BSS BSS2. At this time, a BSS color conflict occurs in which the first BSS BSS1 and the second BSS BSS2 use the same BSS color. The first station STA1 receives a frame (BSS intra-frame) from the second station STA2. The first station STA1 sets the intra-BSS NAV based on the frame sent from the second station STA2. In addition, the first station STA1 receives a frame (BSS inter-frame) from the third station STA3. However, because the first BSS BSS1 and the second BSS BSS2 have the same BSS color, the first station STA1 recognizes the frame received from the third station STA3 as an intra-BSS frame. Therefore, the first station STA1 sets the intra-BSS NAV based on the frame received from the third station STA3. However, when the value of the duration field indicated by the frame received from the third station STA3 is less than the value of the currently set NAV, the first station STA1 does not set the intra-BSS NAV. Then, the first station STA1 receives a CF-End frame from the second station STA2. The first station STA1 resets the BSS intra-NAV based on the CF-End frame received from the second station STA2. Thereafter, the first station STA1 may send a frame even when attempting the transmission of the third station STA3. Therefore, the transmission of the first station STA1 may conflict with the transmission of the third station STA3.

[0134] You can refer to Fig.10 The described embodiments address Fig.10 However, even if we follow the reference Fig. 9 In the described embodiment, the operation of the wireless communication terminal that receives the CF-End frame may also be a problem. Fig.11 Describe this.

[0135] Fig.11 The operation of a wireless communication terminal according to another embodiment of the present invention to determine whether to reset the NAV based on the CF-End frame when a BSS color conflict occurs is shown.

[0136] As described above, the wireless communication terminal may determine whether to reset the NAV based on the BSS that sends the CF-End frame. Specifically, when the BSS that sends the PPDU that sets the currently set NAV is the same as the BSS that sends the CF-End frame, the wireless communication terminal may reset the currently set NAV. Additionally, when the BSS that sends the PPDU that sets the currently set NAV is different from the BSS that sends the CF-End frame, the wireless communication terminal may not reset the NAV.

[0137] In addition, when the NAV is set by a PPDU in which the PPDU is not identified as an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU, the wireless communication terminal may not reset the NAV based on the CF-End frame sent from the BSS. In addition, when the NAV is set by a PPDU in which the PPDU is not identified as an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU, the wireless communication terminal may not reset the NAV based on the CF-End frame sent from the BSS corresponding to the multi-BSSID set, which includes the BSSID corresponding to the BSS of the wireless communication terminal. Through this embodiment, the wireless communication terminal can prevent interference with transmission in the OBSS caused by BSS color conflicts. In addition, as described above, the BSS color signaled by the PPDU may be the BSS color signaled by the BSS color field of the PPDU. Specifically, the BSS color signaled by the PPDU may be the BSS color signaled by the BSS color field of the HE-SIG-A of the PPDU.

[0138] As described above, the case where the wireless communication terminal cannot identify whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU may include a case where the wireless communication terminal recognizes a BSS color conflict. Fig.12 A method of determining whether a wireless communication terminal conflicts with a BSS color is described in detail.

[0139] Fig.12 The operation of the wireless communication terminal according to the embodiment of the present invention to recognize the BSS color conflict is shown.

[0140] The wireless communication terminal can determine the BSS color conflict based on the MAC header. Specifically, the wireless communication terminal can determine the BSS color conflict based on the address field of the MAC header. In a specific embodiment, if there are two or more MAC address fields in the MAC header, at least one of these MAC address fields corresponds to a BSSID within the BSS, or at least one of these MAC address fields corresponds to a multi-BSSID set in a BSSID including a BSSID within the BSS, then the wireless communication terminal can determine the corresponding PPDU as an intra-BSS PPDU. This is because in the case of BSS color, a conflict may occur due to the size limitation of the BSS color field, but the MAC address indicated by the address field of the MAC header is a unique value for each wireless communication terminal and there is no possibility of conflict.

[0141] However, the wireless communication terminal may determine that the destination of the MAC frame included in the PPDU is not the wireless communication terminal based on at least one of the signaling field of the PPDU and the PPDU format, and may not decode the MAC header. Specifically, when the non-AP wireless communication terminal receives a HE single-user (SU) PPDU, the BSS color indicated by the signaling field of the corresponding PPDU is equal to the BSS color within the BSS, and the corresponding PPDU is a downlink transmission PPDU, the non-AP wireless communication terminal may continue to decode. At this time, the non-AP wireless communication terminal may determine that the corresponding PPDU is a SU PPDU through L-SIG signaling. In addition, the non-AP wireless communication terminal may determine that the corresponding PPDU is an extended range SUPPDU based on L-SIG signaling and the HE-SIG-A modulation method. In addition, the non-AP wireless communication terminal may determine whether the corresponding PPDU is a PPDU for downlink transmission based on the DL / UL field of the HE-SIG-A field.

[0142] However, when the PPDU received by the non-AP wireless communication terminal is an uplink transmission PPDU, the non-AP wireless communication terminal may not decode the MAC frame included in the corresponding PPDU. This is because it is clear that the PPDU is a PPDU for uplink transmission and the destination of the PPDU is not a non-AP wireless communication terminal. In addition, when the PPDU received by the non-AP wireless communication terminal is a MU PPDU and the identifier of the non-AP wireless communication terminal is not included in the wireless communication terminal identifier (STAID) field of the signaling field of the PPDU, the non-AP wireless communication terminal may not decode the MAC frame included in the corresponding PPDU. At this time, the signaling field of the PPDU may be HE-SIG-B. In addition, the case where the wireless communication terminal identifier (STAID) field of the signaling field of the PPDU does not include the identifier of the non-AP wireless communication terminal may include the following case: the wireless communication terminal (STAID) field of the signaling field of the PPDU does not include the following broadcast address / multicast address, which includes a non-AP wireless communication terminal.

[0143] Even when it is clear that the destination of the MAC frame included in the PPDU is not the wireless communication terminal, the non-AP wireless communication terminal can decode the MAC frame included in the corresponding PPDU. Specifically, even when the destination of the MAC frame included in the PPDU is not the wireless communication terminal, the non-AP wireless communication terminal can decode the header of the MAC frame included in the PPDU. Specifically, the case where it is clear that the destination of the MAC frame included in the PPDU is not the wireless communication terminal may include the following cases: the above-mentioned corresponding PPDU is a HE single-user (SU) PPDU, the BSS color indicated by the signaling field of the corresponding PPDU is the same as the BSS color within the BSS, and the corresponding PPDU is a downlink PPDU. In addition, the case where it is clear that the destination of the MAC frame included in the PPDU is not the wireless communication terminal may include the following case: the identifier of the non-AP wireless communication terminal is not included in the wireless communication terminal identifier (STAID) field of the signaling field of the PPDU as described above.

[0144] When a wireless communication terminal cannot identify whether a PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on a BSS color value indicated by a signaling field of the PPDU, other wireless communication terminals may not identify whether a PPDU sent from a corresponding BSS is an intra-BSS PPDU or an inter-BSS PPDU, so that a malfunction may occur. In addition, another wireless communication terminal cannot identify whether a PPDU sent by the wireless communication terminal is an intra-BSS PPDU or an inter-BSS PPDU, so that the PPDU sent by the wireless communication terminal may cause other wireless communication terminals to malfunction. In order to prevent such a malfunction problem, the wireless communication terminal may operate as in the following embodiments.

[0145] Specifically, the wireless communication terminal may send a PPDU by including signaling information indicating that the operation based on the BSS color is not allowed in the signaling field of the PPDU. At this time, the wireless communication terminal that receives the PPDU including the signaling information indicating that the operation based on the BSS color is not allowed may not perform the operation based on the BSS color. In a specific embodiment, the wireless communication terminal may send it by setting the BSS color value indicated by the signaling field of the PPDU to a predetermined value. At this time, the predetermined value may be a reserved value that is not used in the BSS color when the BSS color is selected by the AP. For example, the predetermined value may be zero.

[0146] In addition, when the wireless communication terminal receives signaling information indicating that the operation based on the BSS color is not allowed, the wireless communication terminal may not perform the operation based on the BSS color value. Specifically, when the BSS color value indicated by the signaling field of the PPDU received by the wireless communication terminal is a predetermined value, the wireless communication terminal may not perform the above-mentioned SR operation based on the BSS color value. In addition, the wireless communication terminal can send the PPDU through the traditional PPDU by including signaling information indicating that the operation based on the BSS color is not allowed in the signaling field of the PPDU. Specifically, the wireless communication terminal can send the signaling information indicating that the operation based on the BSS color is not allowed even by using the BW signaling method of the MAC address or using the reserved bit of the MAC header.

[0147] In addition, when the wireless communication terminal receives a PPDU indicating a predetermined value in a BSS color, the wireless communication terminal may not perform an operation based on the BSS color. Specifically, when the wireless communication terminal receives a PPDU indicating a predetermined value as a BSS color, the wireless communication terminal may not perform an SR operation on the corresponding PPDU. In a specific embodiment, when the wireless communication terminal receives a PPDU indicating a predetermined value as a BSS color, the wireless communication terminal may regard the PPDU as an intra-BSS PPDU. Therefore, when the wireless communication terminal receives a PPDU indicating a predetermined value as a BSS color, the wireless communication terminal may not discard the corresponding PPDU.

[0148] In addition, a wireless communication terminal that receives signaling information indicating that BSS color-based operation is not allowed can access the channel without using SR operation. Specifically, a wireless communication terminal that receives signaling information indicating that BSS color-based operation is not allowed can access the channel without using BSS color values.

[0149] Even if a non-AP wireless communication terminal that has not received a signaling signal for a BSS color arbitrarily selects a BSS color, this may cause a wireless communication terminal that operates based on the BSS color to malfunction. A method for preventing this is needed.

[0150] The AP operating the BSS may select a BSS color corresponding to the BSS. The non-AP wireless communication terminal may obtain the BSS color assigned to the non-AP wireless communication terminal from the BSS color field included in the HE operation element received from the AP. Specifically, the non-AP wireless communication terminal may receive a management frame from an AP associated with the non-AP wireless communication terminal, and obtain the BSS color assigned to the non-AP wireless communication terminal from the BSS color field of the HE operation element included in the received management frame. At this time, the management frame may be any one of a beacon frame, an association request frame, an association response frame, a reassociation request frame, a reassociation response frame, a probe request frame, and a probe response frame.

[0151] When a non-AP wireless communication terminal fails to receive information for signaling a BSS color, the non-AP wireless communication terminal may use a predetermined value as a BSS color value when communicating with another wireless communication terminal. At this time, the predetermined value may be a reserved value that is not used in the BSS color when the BSS color is selected by the AP. For example, the predetermined value may be zero. Specifically, if the non-AP wireless communication terminal does not receive information for signaling a BSS color, the non-AP wireless communication terminal may set the BSS color value signaled by the PPDU sent by the non-AP wireless communication terminal to a predetermined value. In addition, when the non-AP wireless communication terminal fails to receive information for signaling a BSS color, the non-AP wireless communication terminal may set the BSS color value signaled by the frame sent by the non-AP wireless communication terminal to a predetermined value. When the non-AP wireless communication terminal does not receive information for signaling a BSS color, this is because there is no BSS color. Specifically, when the non-AP wireless communication terminal does not receive information for signaling a BSS color, the non-AP wireless communication terminal may not be associated with any AP. In addition, the case where the non-AP wireless communication terminal does not receive information for signaling the BSS color may include a case where the non-AP wireless communication terminal can establish a tunnel direct link setup (TDLS) link, a direct link setup (DLS) link, or an IBSS (independent) membership. In addition, the case where the non-AP wireless communication terminal does not receive information for signaling the BSS color may include the following case: after receiving signaling information from the AP indicating that an operation based on the BSS color value is not allowed, the non-AP wireless communication terminal does not receive information about the changed BSS color value.

[0152] In a specific embodiment, when the non-AP wireless communication terminal fails to receive the HE operation element, the non-AP wireless communication terminal may set the BSS color value included in the PPDU sent by the non-AP wireless communication terminal to a predetermined value. For example, the non-AP wireless communication terminal may use a predetermined value as the BSS color value when sending a probe request frame. Specifically, the non-AP wireless communication terminal may set the value of the BSS color field included in the HE operation element to a predetermined value when sending a probe request frame. When sending a probe request frame, the non-AP wireless communication terminal may set the value of the BSS color field of the HE-SIG-A field of the PPDU including the probe request frame to a predetermined value.

[0153] In another specific embodiment, when sending a PPDU to a wireless communication terminal between BSSs, the wireless communication terminal may set the BSS color value indicated by the PPDU to a predetermined value. It is likely that the wireless communication terminal does not know the BSS color between BSSs. In addition, this is because the wireless communication terminal between BSs may ignore the PPDU indicating the BSS color of the BSS including the wireless communication terminal.

[0154] In addition, when the wireless communication terminal receives a PPDU indicating a predetermined value as a BSS color, the wireless communication terminal may not perform an operation based on the BSS color. Specifically, when the wireless communication terminal receives a PPDU indicating a predetermined value as a BSS color, the wireless communication terminal may not perform an SR operation on the corresponding PPDU. In a specific embodiment, when the wireless communication terminal receives a PPDU indicating a predetermined value as a BSS color, the wireless communication terminal may regard the PPDU as an intra-BSS PPDU. Therefore, when the wireless communication terminal receives a PPDU indicating a predetermined value as a BSS color, the wireless communication terminal may not discard the corresponding PPDU.

[0155] The non-legacy PPDU includes a signaling field indicating the BSS color, such as the HE-SIG-A field, and the wireless communication terminal can perform the various SR operations described above based on the signaling field indicating the BSS color. However, the legacy PPDU does not include a signaling field indicating the BSS color. Therefore, the wireless communication terminal that receives the legacy PPDU must perform an SR operation based on the MAC frame included in the PPDU. However, there is a MAC frame that only includes the receiver address RA but not the sender address TA. When an operation based on the BSS color may not be performed because a MAC frame including only the receiver address is sent via the legacy PPDU or a BSS color conflict occurs, an SR operation for a MAC frame including only the receiver address may be a problem. Reference will be made to Fig.13 and Fig.14 Embodiments of a wireless communication terminal related thereto are described.

[0156] Fig.13MAC frame formats of a Clear to Send (CTS) frame and an ACK frame according to an embodiment of the present invention are shown. Fig.14 An operation of a wireless communication terminal setting NAV based on an RTS frame and a CTS frame according to an embodiment of the present invention is shown.

[0157] The MAC frame of the CTS frame and the ACK frame may include a frame control field including information about frame control. In addition, the MAC frame of the CTS frame and the ACK frame may include a duration field for NAV setting. In addition, the MAC frame of the CTS frame and the ACK frame may include an RA field indicating a receiver address. In addition, the MAC frame of the CTS frame and the ACK frame may include an FCS field indicating whether the MAC frame includes an error.

[0158] The RA field of the CTS frame can be set based on the TA field of the RTS frame. Specifically, the value of the TA field of the RA field of the CTS frame can be a value that sets the individual / group bit to zero. In addition, when the CTS frame is the first frame of the transmission sequence, the RA field can be set to the MAC address of the sender.

[0159] The RA field of the ACK frame can be set based on the Address 2 field of a data frame, a management frame, a BlockACKReq frame, a BlockACK frame, or a PS-poll frame sent to a wireless communication terminal. Specifically, the RA field of the ACK frame can set the Address 2 field value of a data frame, a management frame, a BlockACKReq frame, a BlockACK frame, or a PS-poll frame sent to a wireless communication terminal to a non-bandwidth signaling TA value. In addition, the RA field of the ACK frame can be set to the MAC address of the recipient.

[0160] When the wireless communication terminal may not determine whether the frame is an intra-BSS frame or an inter-BSS frame based on the address field of the CTS frame or the ACK frame, the wireless communication terminal may set the basic NAV based on the corresponding frame. Specifically, when the wireless communication terminal may not determine whether the frame is an intra-BSS frame or an inter-BSS frame based on the PPDU including the CTS frame or the ACK frame and may not determine whether the frame is an intra-BSS frame or an inter-BSS frame based on the address field of the CTS frame or the ACK frame, the wireless communication terminal may set the basic NAV based on the frame. In addition, the case where the wireless communication terminal may not determine whether the frame is an intra-BSS frame or an inter-BSS frame based on the address field of the CTS frame or the ACK frame may be the following case: the address field of the CTS frame or the ACK frame is one and the corresponding address field does not indicate the AP address or the BSSID. In a specific embodiment, a non-AP wireless communication terminal may receive a downlink (DL) CTS frame. At this time, the address field of the corresponding CTS frame may include the address of the non-AP wireless communication terminal and may not include the address or the BSSID of the wireless communication terminal as the AP. Therefore, the wireless communication terminal receiving the corresponding CTS frame may not determine whether the corresponding CTS frame is an inter-BSS frame or an intra-BSS frame based on the address field of the corresponding CTS frame. In addition, when the wireless communication terminal may not determine whether the frame is an intra-BSS frame or an inter-BSS frame based on the PPDU including the CTS frame or the ACK frame, the corresponding PPDU may be a conventional PPDU. This is because the conventional PPDU may not include information indicating the BSS color. In addition, the case where the wireless communication terminal may not be able to determine whether the frame is an intra-BSS frame or an inter-BSS frame based on the PPDU including the CTS frame or the ACK frame may be the following: the wireless communication terminal may not be able to determine whether the frame is an intra-BSS frame or an inter-BSS frame based on the BSS color indicated by the signaling field of the corresponding PPDU as in the above-mentioned embodiment.

[0161] In another specific embodiment, when the wireless communication terminal receives a frame, the wireless communication terminal can set the basic NAV based on the frame regardless of the value of the address field of the frame. For example, when receiving a downlink (DL) CTS frame or an uplink (UL) CTS frame, the wireless communication terminal can set the basic NAV based on the frame.

[0162] In addition, when the wireless communication terminal maintains a NAV, instead of setting a basic NAV based on a corresponding frame in the above-mentioned embodiment, the wireless communication terminal may consider that the NAV set by the corresponding frame is not set by a BSS intra-frame. Specifically, when the wireless communication terminal may not determine whether a frame is a BSS intra-frame or an inter-BSS frame based on an address field of a CTS frame or an ACK frame, the wireless communication terminal may consider that the NAV set on a frame basis is not set by a BSS intra-frame. In addition, when the wireless communication terminal receives a frame, the wireless communication terminal may consider that the NAV set based on the frame is not set by a BSS intra-frame, regardless of the value of the address field of the frame.

[0163] exist Fig.14 In the embodiment of the present invention, the first station STA1 to the third station STA3 are all included in the same BSS. The first station STA1 sends an RTS frame and the second station STA2 sends a CTS frame in response to the RTS frame. The third station STA3 sets the BSS intra-NAV based on the RTS frame. Because the address field of the CTS frame sent by the second station STA2 includes only the address of the first station STA1, the third station STA3 may not clearly determine whether the CTS frame sent by the second station STA2 is sent from the BSS intra-frame. Therefore, the third station STA3 sets the basic NAV based on the CTS frame sent by the second station STA2 as in some of the above-mentioned embodiments.

[0164] At this time, when the third station STA3 receives the CF-End frame transmitted from the first station STA1 or the second station STA2, the third station STA3 recognizes the received CF-End frame as an intra-BSS frame. Therefore, even if the third station STA3 receives the CF-End frame transmitted from the first station STA1 or the second station STA2, the third station STA3 resets only the inner NAV based on the received CF-End frame, and the basic NAV is maintained. When the third station STA3 does not receive the RTS frame but receives the CF-End frame from the BSS in the state of receiving only the CTS frame, the third station STA3 may initiate transmission during the transmission process of the first station STA1 and the second station STA2, thereby causing interference.

[0165] To solve this problem, the wireless communication terminal may send a PPDU including only one address field in the format of a PPDU that signals the BSS color. However, when sending a PPDU that signals the BSS color, a conventional wireless communication terminal may not decode the PPDU. In addition, the wireless communication terminal may infer the BSS of the CTS frame and the ACK frame based on the frame sent before the CTS frame or the ACK frame. To this end, there is a problem that the wireless communication terminal may be required to receive the previously sent frames and store information about the received frames. Therefore, the wireless communication terminal may send information identifying the BSS through a conventional PPDU. Reference will be made to Figures 15 to 17 Describe this.

[0166] Fig.15 The format of an 802.11a PPDU according to an embodiment of the present invention is shown.

[0167] The 802.11a PPDU includes a short training field including a relatively short training signal, a long training field including a relatively long training signal, a signal field including signaling information, and a data field including data. The data field may include a service field, a PSDU, and tail bits. The data field may also include padding bits as needed. Specifically, the format of the 802.11a PPDU may be similar to Fig.15 The format is the same.

[0168] At this time, the wireless communication terminal can use the service field to send information identifying the BSS. Specifically, the wireless communication terminal can use the reserved bits of the service field to send information identifying the BSS. Specifically, the bits from the first bit B0 to the seventh bit B6 of the service field can be scrambler initialization bits. The remaining nine bits except the scrambler initialization bit are reserved. Therefore, the wireless communication terminal can use part or all of the nine reserved bits to send information identifying the BSS.

[0169] In addition, the information for identifying the BSS may be any one of a BSS color, a BSSID, and a partial BSS color. In addition, the information for identifying the BSS may be a partial AID generated based on the BSS color. In addition, the information for identifying the BSS may be a part of the BSSID or information generated based on the BSSID. At this time, the information generated based on the BSSID may be a value obtained by calculating a partial value of the BSSID or a value obtained by calculating the BSSID.

[0170] According to another specific embodiment, the wireless communication terminal may also send the information identifying the BSS through a field other than the service field. Specifically, the wireless communication terminal may send the information identifying the BSS through a signal field.

[0171] In addition, the wireless communication terminal can transmit information identifying the BSS by combining a plurality of reserved fields.

[0172] In these embodiments, the wireless communication terminal receiving the PPDU can obtain information identifying the BSS based on the reserved field of the PPDU. In addition, the wireless communication terminal receiving the PPDU can determine whether the corresponding PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on the obtained information identifying the BSS.

[0173] Fig.16 The format of the service field of the PPDU according to an embodiment of the present invention is shown.

[0174] As reference Fig.15 As described above, the wireless communication terminal can use the reserved bits of the service field to send information identifying the BSS. Specifically, the wireless communication terminal can use the eighth bit B7 to the thirteenth bit B12 of the service field to send information identifying the BSS. Figure 15 to Figure 16 The described embodiments use reserved bits, so a legacy wireless communication terminal that does not support embodiments of the present invention may not decode the information identifying the BSS, but may successfully receive a PPDU according to embodiments of the present invention.

[0175] When the address field of the MAC frame is one, the wireless communication terminal may apply the reference Figure 15 to Figure 16 However, reference Figure 15 to Figure 16 The described embodiment is not limited thereto, and even when the number of address fields of the MAC frame is two or more, the wireless communication terminal may apply the reference Figure 15 to Figure 16 Embodiment described.

[0176] Fig.17 The wireless communication terminal according to the embodiment of the present invention is shown Figure 15 to Figure 16 An embodiment of setting the operation of NAV.

[0177] exist Fig.17 In the embodiment of FIG. 1 , the first station STA1 to the third station STA3 are all included in the same BSS. The first station STA1 sends an RTS frame and the second station STA2 sends a CTS frame in response to the RTS frame. The third station STA3 sets the BSS intra-NAV based on the RTS frame. The address field of the CTS frame sent by the second station STA2 includes only the address of the first station STA1, but as in the reference Figure 15 to Figure 16 As in the described embodiment, the reserved field of the PPDU including the CTS frame sent by the second station STA2 includes information identifying the BSS. In this case, the reserved field may be a reserved bit in the service field. The third station STA3 obtains information identifying the BSS based on the reserved field. The third station STA3 may set the BSS intra-NAV based on the information identifying the BSS. Fig.17 In the embodiment of FIG. 5 , the third station STA3 does not set the value of the intra-BSS NAV because the value of the intra-BSS NAV that has been set is equal to the value of the NAV indicated by the duration field of the CTS frame.

[0178] Therefore, even when the address field of the MAC frame is one, the third station STA3 can correctly set the intra-BSS NAV and the basic NAV. Thereafter, when the third station STA3 receives a CF-End frame from within the BSS, the third station STA3 can reset the intra-BSS NAV. In addition, when the third station STA3 receives a CF-End frame from between the BSSs, the third station STA3 may not reset the intra-BSS NAV.

[0179] Fig.18 A method of setting a partial AID and group ID field of a VHT-SIG-A by a wireless communication terminal according to an embodiment of the present invention is shown.

[0180] The VHT-SIG-A field may include a partial AID field and a group ID field. The partial AID field may indicate information identifying the connection between the AP and the wireless communication terminal and information identifying the BSS. Specifically, the partial AID field of the PPDU sent to the AP may indicate the BSSID of the AP. In addition, the partial AID field of the PPDU sent to the non-AP wireless communication terminal may be an identifier obtained by combining the AID of the non-AP wireless communication terminal and the BSSID of the AP associated with the non-AP wireless communication terminal. In addition, when the PPDU is sent to the mesh station, the value of the partial AID field may be a value corresponding to the last 9 bits of the recipient address. In a specific embodiment, the partial AID field may be a 9-bit field.

[0181] The group ID field may indicate whether the data in the data field is for a multi-user (MU). Specifically, when the data in the data field is for a single user (SU), the value of the group ID field may be 0 or 63. In a specific embodiment, if the PPDU is sent to an AP, the value of the group ID field may be zero. In addition, when the PPDU is sent to a non-AP wireless communication terminal, the value of the group ID field may be 63. In addition, when the PPDU is sent to a mesh station, the value of the group ID field may be zero. In a specific embodiment, the group ID field may be a 6-bit field.

[0182] The wireless communication terminal can transmit information identifying the BSS through the partial AID field and the group ID field of the VHT-SIG-A. Specifically, the wireless communication terminal as an AP can set the partial AID field value to the non-AP wireless communication terminal according to the following equation.

[0183] (dec(AID[0:8])+dec(BSSID[44:47]XOR BSSID[40:43])*2^5)mod 2^9

[0184] XOR represents an exclusive OR operation of a bit operation, mod X represents the remainder when divided by X, and dec(A[b:c]) represents the number of binary digits from the b+1th bit to the c+1th bit of A in decimal.

[0185] At this time, the wireless communication terminal acting as an AP can set the group ID field to 63.

[0186] In addition, when the wireless communication terminal is a direct link setup (DLS) station or a tunnel direct link setup (TDLS) station and the wireless communication terminal sends a PPDU in a direct path and the receiver of the PPDU or PSDU is a DLS station or a TDLS station, the wireless communication terminal can set the partial AID field of the PPDU according to the above formula. At this time, the wireless communication terminal can set the group ID field to 63.

[0187] Figures 19 to 20 A method of determining whether a frame received by a wireless communication terminal is an inter-BSS frame or an intra-BSS frame according to an embodiment of the present invention is shown.

[0188] Fig.19 A method of determining whether a corresponding PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on whether a PPDU received by a wireless communication terminal is a downlink PPDU according to an embodiment of the present invention is illustrated.

[0189] As described above, the wireless communication terminal can perform identification based on the BSS color indicated by the signaling field of the PPDU. In addition, the wireless communication terminal can identify whether the received frame is an inter-BSS frame or an intra-BSS frame based on the MAC header of the frame. Specifically, when the receiver address RA or the sender address TA of the MAC header of the frame received by the wireless communication terminal is a BSSID of the BSS of the wireless communication terminal or a bandwidth signaling variant of the BSSID, the wireless communication terminal can identify the received frame as an intra-BSS frame.

[0190] The wireless communication terminal can identify whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on information other than the BSS color value indicated by the MAC address and signaling fields of the PPDU. Specifically, the wireless communication terminal can identify whether the received PPDU is an inter-BSS PPDU based on other parameter values ​​of RXVECTOR. Specifically, when a BSS color conflict occurs, the wireless communication terminal can identify whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on information other than the BSS color value indicated by the signaling field of the PPDU. Specifically, when the frame received by the wireless communication terminal is a downlink frame, the wireless communication terminal can identify the frame as an inter-BSS frame. In a specific embodiment, even if the BSS color value indicated by the BSS color field of the signaling field of the PPDU or the BSS color indicated by the partial AID field is the same as the BSS color of the BSS including the wireless communication terminal, when the frame received by the wireless communication terminal as an AP is a downlink frame, the wireless communication terminal can identify the frame as an inter-BSS frame. For example, in Fig.19 In an embodiment of the present invention, the AP receives a PPDU for downlink transmission and determines the PPDU as an inter-BSS frame.

[0191] In addition, when the value of the group ID field of the VHT-SIG-A field of the PPDU received by the wireless communication terminal is 63, the wireless communication terminal can recognize the received PPDU as an inter-BSS PPDU. This is because, as shown in FIG. Fig.18 As described, the group ID field of the PPDU sent to the non-AP wireless communication terminal is set to 63. At this time, only when the DLS protocol or the TDLS protocol is not used, the wireless communication terminal as the AP can identify the received PPDU as an inter-BSS PPDU. As described above, this is because even when the DLS wireless communication terminal or the TDLS wireless communication terminal sends a PPDU to the DLS wireless communication terminal or the TDLS wireless communication terminal through a direct path, the value of the group ID field is set to 63.

[0192] In addition, the wireless communication terminal as the AP can identify whether the VHT PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on the partial AID field of the VHT PPDU. Specifically, the wireless communication terminal as the AP can identify whether the VHT PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on the partial AID field and the group ID field of the VHT PPDU. In a specific embodiment, when the value of the partial AID field is a value that does not exist in the BSS operated by the wireless communication terminal, the AP can identify the corresponding PPDU as an inter-PPDU.

[0193] In addition, when a wireless communication terminal as an AP receives a VHT MU PPDU, the wireless communication terminal can identify the PPDU as an inter-PPDU. This is because the VHT MU PPDU can be used only for downlink transmission. Specifically, the wireless communication terminal as an AP can determine that the corresponding PPDU is a VHT MU PPDU through automatic detection and the VHT-SIG-A field. In addition, if the group ID of the VHT-SIG-A is not 0 or 63, the wireless communication terminal as an AP can identify the corresponding PPDU as a MU PPDU.

[0194] In addition, when the wireless communication terminal as an AP receives an HE PPDU and the UL / DL field of the HE-SIG-A field indicates downlink transmission, the wireless communication terminal as an AP can identify the corresponding PPDU as an inter-BSS PPDU. At this time, the value of the UL / DL field can be zero. At this time, only when the DLS protocol or the TDLS protocol is not used, the wireless communication terminal as an AP can identify the received PPDU as an inter-BSS PPDU.

[0195] When the wireless communication terminal of the AP receives the HE PPDU and the corresponding PPDU is not transmitted to the wireless communication terminal included in the IBSS and the UL_FLAG field of the HE-SIG-A field indicates downlink transmission, the wireless communication terminal as the AP can identify the PPDU as an inter-BSS PPDU. At this time, the wireless communication terminal as the AP can determine whether the DLS protocol or the TDLS protocol is used, and therefore can determine whether the received PPDU is not transmitted to the wireless communication terminal included in the IBSS.

[0196] When the wireless communication terminal as the AP receives a triggered PPDU from the wireless communication terminal that has not been triggered, the wireless communication terminal as the AP triggers and can identify the corresponding PPDU as an inter-BSS PPDU. Specifically, when the wireless communication terminal as the AP receives a triggered PPDU without sending a trigger frame, the wireless communication terminal as the AP can identify the PPDU as an inter-BSS PPDU.

[0197] Fig. 20 A method for a wireless communication terminal to identify whether a received MAC frame is an intra-BSS frame or an inter-BSS frame based on SR-related information according to an embodiment of the present invention is shown.

[0198] As described above, when a wireless communication terminal as an AP receives a PPDU for downlink transmission, the wireless communication terminal as an AP can identify the PPDU as an inter-PPDU. This is because the PPDU of the destination of the wireless communication terminal as an AP within the BSS is a PPDU for uplink transmission. In addition, the AP as an AP can identify whether the corresponding PPDU is an inter-BSS PPDU based on the SR related information indicated by the PPDU. The SR related information included in the PPDU may indicate that the PPDU includes a trigger frame. In addition, the trigger frame is only used for downlink transmission. Therefore, the wireless communication terminal as an AP can determine whether the corresponding PPDU is a PPDU for downlink transmission based on whether the PPDU includes a trigger frame. Therefore, the wireless communication terminal can identify whether the corresponding PPDU is an inter-BSS PPDU based on the SR related information.

[0199] At this time, the SR related information may be an SR field of a signaling field of the PPDU. Specifically, the signaling field of the PPDU may indicate whether an SR operation is allowed while the corresponding PPDU is being sent, and may indicate the conditions for the permission. At this time, the signaling field may be a HE-SIG-A field. Specifically, the SR field may indicate SR_Delay, which indicates that the SR operation will be delayed. If the PPDU is a HE SU PPDU or a HE extended range SU PPDU, and the corresponding PPDU includes a trigger frame, the SR field indicates SR_Delay.

[0200] In addition, the SR field may indicate SR_Restricted, which indicates that the SR operation is restrictively allowed. Specifically, when the SR field of the PPDU has the SR_Restricted value, during the SR operation of the inter-BSS wireless communication terminal, the TXOP duration of the transmission of the inter-BSS wireless communication terminal may be limited to the PPDU including the trigger frame. In addition, when the PPDU is a HE MU PPDU and the corresponding PPDU includes a trigger frame, the SR field indicates SR_Restricted.

[0201] In addition, the SR field may indicate SR_Disallowed, which indicates that the SR operation is not allowed. A wireless communication terminal that transmits a PPDU including a trigger frame indicates through the SR field of the PPDU that the PPDU includes a trigger frame and can protect a transmission sequence based on the trigger frame.

[0202] Therefore, when the SR field value of the PPDU received by the wireless communication terminal as an AP is SR_Restricted or SR_Delay, the wireless communication terminal as an AP can identify the PPDU as an inter-BSS PPDU based on the type of the PPDU and the SR field. Specifically, when the PPDU received by the wireless communication terminal AP is a HE single user (SU) PPDU or a HE extended range SUPPDU, and the SR field signaled by the corresponding PPDU indicates SR_Restricted, the wireless communication terminal as an AP can identify the PPDU as an inter-BSS PPDU. In addition, when the PPDU received by the wireless communication terminal is a HE MU PPDU and the value of the SR field signaled by the PPDU indicates SR_Delayed, the wireless communication terminal as an AP can identify the PPDU as an inter-BSS PPDU. At this time, the HE SU PPDU indicates a PPDU for transmission to a single wireless communication terminal. In addition, the HE extended range SU PPDU indicates a PPDU for transmission to a single wireless communication terminal. In addition, the HE MU PPDU indicates a PPDU for multiple wireless communication terminals.

[0203] In addition, in a specific embodiment, when the PPDU received by the non-AP wireless communication terminal is an inter-BSS PPDU or an intra-BSS PPDU, the non-AP wireless communication terminal may prioritize the determination based on the SR-related information indicated by the PPDU over the determination based on the BSS color value indicated by the PPDU signaling field.

[0204] exist Fig. 20 In the embodiment, the first AP AP1 sends a trigger frame for triggering transmission of the first station STA1 and the second station STA2. At this time, the second AP AP2 receives the PPDU including the trigger frame sent by the first AP AP1. The second AP AP2 can recognize that the corresponding PPDU is the PPDU including the trigger frame through the SR field value of the PPDU including the trigger frame sent by the first AP AP1. Therefore, the second AP AP2 can identify the PPDU including the trigger frame sent by the first AP AP1 as an inter-BSS PPDU. In particular, even when the BSS color x of the BSS operated by the second AP AP2 is the same as the BSS color x of the BSS operated by the first AP AP1, the second AP AP2 can also identify the PPDU including the trigger frame sent by the first AP AP1 as an inter-BSS PPDU.

[0205] Fig.21A method for a wireless communication terminal to determine whether a corresponding PPDU is an inter-BSS PPDU or an intra-BSS PPDU when a PPDU received by the wireless communication terminal according to an embodiment of the present invention satisfies both an inter-BSS PPDU condition and an intra-BSS PPDU condition is illustrated.

[0206] When a frame received by a wireless communication terminal satisfies both the inter-BSS frame condition and the intra-BSS frame condition, the wireless communication terminal may identify the frame as an inter-BSS frame. Specifically, when a frame received by a wireless communication terminal satisfies both the inter-BSS frame condition and the intra-BSS frame condition and the wireless communication terminal cannot identify whether the frame is an inter-BSS frame or an intra-BSS frame based on a MAC address, the wireless communication terminal may identify the frame as an inter-BSS frame. In this case, the case where the wireless communication terminal cannot identify an inter-BSS frame or an intra-BSS frame based on a MAC address may include the following case: the wireless communication terminal cannot decode a MAC header of the corresponding frame.

[0207] In addition, in the above-mentioned embodiment, the BSS inter-frame condition and the BSS intra-frame condition may include all conditions for identifying whether the wireless communication terminal is an inter-BSS frame or an intra-BSS frame. For example, the wireless communication terminal can identify whether the frame is an inter-BSS frame or an intra-BSS frame based on the BSS color value indicated by the BSS color field of the signaling field of the PPDU including the MAC frame. As described above, the BSS color signaled by the PPDU can be the BSS color signaled by the BSS color field of the PPDU. Specifically, the BSS color signaled by the PPDU can be the BSS color signaled by the BSS color field of the HE-SIG-A of the PPDU.

[0208] In addition, the wireless communication terminal can identify whether the frame is an inter-BSS frame or an intra-BSS frame based on the value of the partial AID field of the signaling field of the PPDU including the frame. In addition, the wireless communication terminal can identify whether the frame is an inter-BSS frame or an intra-BSS frame based on the address field of the frame. In addition, when the wireless communication terminal is an AP and the wireless communication terminal receives a downlink transmission PPDU, the wireless communication terminal can identify the frame included in the corresponding PPDU as an inter-BSS frame.

[0209] If the PPDU includes a BSS color field, the partial AID field is unlikely to include information about the BSS color. Therefore, the situation where the BSS intra-frame condition and the BSS inter-color condition are satisfied at the same time may include the following situation, that is, when the wireless communication terminal performs determination based on the BSS color field or the partial AID field, the corresponding PPDU is identified as the BSS intra-PPDU, and when the wireless communication terminal performs determination based on the address field of the frame, the corresponding PPDU can be identified as the BSS inter-PPDU. Alternatively, when the wireless communication terminal performs determination based on the BSS color field or the partial AID field, the corresponding MAC frame is identified as the BSS intra-frame, and when the wireless communication terminal performs determination based on whether the PPDU including the MAC frame is an uplink transmission format, the corresponding PPDU is identified as the BSS inter-PPDU. Because the number of bits representing the BSS color is limited, a BSS color conflict may occur as described above. Therefore, when the frame received by the wireless communication terminal satisfies both the BSS inter-frame condition and the BSS intra-frame condition, the wireless communication terminal can identify whether the received frame is an inter-BSS frame or an intra-BSS frame based on conditions other than the BSS color indicated by the PPDU. Specifically, when the frame received by the wireless communication terminal satisfies both the inter-BSS frame condition and the intra-BSS frame condition, the wireless communication terminal can identify whether the received frame is an inter-BSS frame or an intra-BSS frame based on conditions other than the BSS color field or the partial AID field of the PPDU. At this time, other conditions can be identified based on the address field of the above-mentioned MAC header. In addition, another condition may be that the PPDU including the frame is a PPDU for downlink transmission.

[0210] exist Fig.21 In the embodiment of the present invention, the first AP AP1 sends a HE MU PPDU including a trigger frame to the first station STA1 and the second station STA2. At this time, the second AP AP2 receives the HE MU PPDU including the trigger frame sent by the first AP AP1. The BSS color of the BSS operated by the first AP AP1 and the second AP is equal to x. Therefore, the BSS color indicated by the HE-SIG-A field of the HE MU PPDU sent by the first AP AP1 satisfies the intra-BSS color condition. However, when the HE MU PPDU sent by the first AP AP1 is a PPDU for downlink transmission including a trigger frame, and as in the above-mentioned embodiment, because when the wireless communication terminal determines that the frame received by the wireless communication terminal is an inter-BSS frame or an intra-BSS frame, the determination based on whether it is a PPDU for downlink transmission takes precedence over the determination based on the BSS color, the second AP AP2 identifies the HE MU PPDU sent by the first AP AP1 as an inter-BSS PPDU.

[0211] The wireless communication terminal may identify the received frame as an intra-BSS frame according to any one of the conditions, and then, identify the received frame as an inter-BSS frame according to the above-mentioned determination priority order. At this time, the wireless communication terminal may use an enhanced CCA level. Specifically, the wireless communication terminal may use a CCA level corresponding to an inter-BSS frame. In a specific embodiment, the CCA level corresponding to an inter-BSS frame may be referred to as an OBSS PD level.

[0212] As described above, the wireless communication terminal can enter the power saving state based on the MAC header. Figure 22 to Figure 23 The specific operations of the wireless communication terminal are described in detail.

[0213] Fig. 22 The wireless communication terminal according to an embodiment of the present invention enters a power saving state based on a MAC header of a frame received by the wireless communication terminal. Fig.23 A case is shown in which a wireless communication terminal enters a power saving state based on a MAC header of a frame received by the wireless communication terminal when the wireless communication terminal according to an embodiment of the present invention is included in a BSS corresponding to a multiple BSSID set.

[0214] When the sender address TA or the receiver address RA indicated by the MAC header of the received frame corresponds to another BSSID of the multi-BSSID set, wherein the multi-BSSID set includes the BSSID of the BSS, and the BSS includes the wireless communication terminal, the wireless communication terminal can determine the received frame as a BSS intra-frame. When the frame received by the wireless communication terminal is an intra-BSS frame and the wireless communication terminal is not the recipient of the received frame, the wireless communication terminal can enter a power saving state. At this time, the wireless communication terminal can maintain the power saving state until the end of the duration of the PPDU including the received frame.

[0215] exist Fig. 22 In the embodiment of the present invention, the first station STA1 and the second station STA2 are associated with the same access point AP. When the access point AP sends a PPDU to the first station STA1, the second station STA2 can receive the PPDU. At this time, the second station STA2 determines whether the received PPDU is a frame within the BSS. When the received PPDU is a frame within the BSS, the second station STA2 determines whether the recipient of the received PPDU is the second station STA2. Specifically, the second station STA2 can determine whether the recipient of the PPDU received based on the MAC header is the second station STA2. At this time, when the second station STA2 is not the recipient of the received PPDU, the second station STA2 can enter a power saving state.

[0216] When entering the power saving state, the wireless communication terminal can determine whether the receiver address RA of the frame indicates multiple wireless communication terminals including the corresponding wireless communication terminal. Specifically, when the received frame is an intra-BSS frame, the receiver address RA of the received frame is not the MAC address of the wireless communication terminal and the receiver address RA of the received frame does not correspond to the broadcast address, the wireless communication terminal can enter the power saving state. At this time, when the receiver address RA of the received frame does not correspond to the multicast address that the wireless communication terminal is required to receive and the receiver address RA of the received frame does not correspond to the group address that the wireless communication terminal is required to receive, the wireless communication terminal can enter the power saving state.

[0217] In a specific embodiment, even when the receiver address RA of the trigger frame or the receiver address RA of the multi-station block ACK (multi-STA BlockACK) frame does not match the MAC address of the wireless communication terminal, the wireless communication terminal may be required to receive the trigger frame or the multi-station block ACK frame. Specifically, when the receiver of the trigger frame is a plurality of wireless communication terminals, the receiver address RA of the trigger frame may be a broadcast address. At this time, the number of user information fields of the trigger frame may be two or more. In addition, when the receiver of the multi-station block ACK frame is a plurality of wireless communication terminals, the receiver address RA of the multi-station block ACK may be a broadcast address. At this time, the number of AID fields in the per-STA information subfield of the multi-station block ACK may be two or more. At this time, the broadcast address may indicate a plurality of wireless communication terminals or one wireless communication terminal.

[0218] Therefore, when the received frame is an intra-BSS frame, the receiver address RA of the received frame is not the MAC address of the wireless communication terminal, the received frame is a trigger frame, and the receiver address RA of the received frame does not correspond to the broadcast address, the wireless communication terminal can enter the power saving state. In addition, when the received frame is an intra-BSS frame, the receiver address RA of the received frame is not the MAC address of the wireless communication terminal, the received frame is a trigger frame, and the receiver address RA of the multi-station block ACK frame does not correspond to the broadcast address, the wireless communication terminal can enter the power saving state.

[0219] Specifically, when the receiver of the trigger frame or the multi-station block ACK frame is a plurality of wireless communication terminals, the receiver address RA may be a multicast address or a group address. Therefore, when the wireless communication terminal receives the trigger frame or the multi-station block ACK frame and the receiver address RA of the received frame is not a multicast address and a group address including the wireless communication terminal, the wireless communication terminal may enter a power saving state.

[0220] When any one of the BSSIDs included in the multi-BSSID set is set to the receiver address RA of the frame or the sender address TA of the frame, only the wireless communication terminal included in the BSS identified by the corresponding BSSID can be the receiver or sender of the corresponding frame. Specifically, for a frame sent to a plurality of wireless communication terminals included in each of two or more BSSs corresponding to the multi-BSSID set, a modified value can be set in the sender address of the frame based on the BSSID. At this time, the wireless communication terminal may not separately determine that the receiver address RA and the sender address TA are broadcast addresses or multicast addresses including the addresses of the wireless communication terminals. For the convenience of explanation, the BSSID of the BSS including the wireless communication terminal is referred to as the first BSSID, and the different BSSIDs are referred to as the second BSSID. Specifically, when the second BSSID is included in the multi-BSSID set including the first BSSID and the receiver address RA or the sender address TA of the frame received by the wireless communication terminal matches the second BSSID, the wireless communication terminal can enter a power saving state.

[0221] exist Fig.23 In an embodiment of the present invention, the multi-BSSID set includes a first BSSID BSSID(1) and a second BSSID BSSID(2). The first station STA1 is included in the BSS identified by the second BSSID BSSID(2) and the second station STA2 is included in the BSS identified by the first BSSID BSSID(1). At this time, the virtual access point with the second BSSID BSSID(2) sends a PPDU to the first station STA1. The second station STA2 receives the corresponding PPDU. The second station STA2 determines whether the received PPDU is an intra-BSS frame. Specifically, the second station STA2 can determine whether the MAC address signaled by the MAC header of the received PPDU is a BSSID of the multi-BSSID set including the first BSSID. Because the sender address TA of the received PPDU is the second BSSID BSSID(2), the second station STA2 determines the received PPDU as an intra-BSS frame. In addition, since the recipient of the received PPDU is a wireless communication terminal included in the BSS identified by the second BSSID BSSID(2), the second station STA2 enters the power saving state.

[0222] When the received PPDU is an inter-BSS frame, the second station STA2 determines whether the recipient of the received PPDU is the second station STA2. Specifically, the second station STA2 may determine whether the recipient of the received PPDU is the second station STA2 based on the MAC header. At this time, when the second station STA2 is not the recipient of the received PPDU, the second station STA2 may enter a power saving state.

[0223] In another specific embodiment, if the reference BSSID is set as the sender address TA of the frame, it can indicate that the sender address TA is sent to a plurality of wireless communication terminals included in two or more BSSs corresponding to the multi-BSSID set. When the second BSSID is included in the multi-BSSID set including the first BSSID, the second BSSID is not the reference BSSID, and the receiver address RA or the sender address TA of the frame received by the wireless communication terminal is sent from the second BSSID, the wireless communication terminal can enter a power saving state.

[0224] As described above, the wireless communication terminal can signal various information through the signaling field of the PPDU. Fig.24 Describes the format of the signaling fields.

[0225] Fig.24 The format of the HE-SIG-B field according to an embodiment of the present invention is shown.

[0226] The HE MU PPDU may include a HE-SIG-B field that signals the information necessary for multi-user transmission. Specifically, the HE-SIG-B field may be classified into a common field for signaling information generally applied to wireless communication terminals participating in multi-user transmission and a user-specific field for signaling information for each of multiple wireless communication terminals participating in multi-user transmission. Both the common field and the user-specific field may be encoded based on 20MHz. Specifically, the common field may include information about resource allocation, such as resource units RUs allocated to multiple wireless communication terminals participating in multi-user transmission and many users in MU-MIMO. In addition, in the user-specific field, information about each of the multiple wireless communication terminals may be arranged in the order listed in the RU allocation field in the common field.

[0227] Specifically, the user-specific field includes information about the station identifier (STAID), the number of spatial streams, transmit beamforming (TxBF), modulation and coding scheme (MCS), dual subcarrier modulation (DCM), and coding. In addition, when multiple wireless communication terminals are assigned to one RU, the user-specific field may include information about the spatial configuration field, MCS, DCM, and coding. At this time, the information about the coding may indicate whether LDPC is used. The common field may include a binary block code (BCC) block. The user-specific field includes information about two wireless communication terminals in one BCC block. At this time, the last BCC block may include information about one wireless communication terminal. In addition, information about a separate wireless communication terminal may be referred to as per-user content. A BCC block may include CRC and tail bits. In addition, the HE-SIG-B field may also include padding to align OFDM symbol boundaries. The format of the specific HE-SIG-B field may be as follows: Fig.24 As shown in (a).

[0228] When the wireless communication terminal sends a PPDU over a frequency bandwidth of 40 MHz or higher, the wireless communication terminal may repeatedly send two HE-SIG-B fields, each with a frequency bandwidth of 20 MHz per 40 MHz, through the entire frequency bandwidth. At this time, the two HE-SIG-B fields may include different information. In addition, each of the two HE-SIG-B fields may include information about the RUs included in the frequency bandwidth in which the corresponding HE-SIG-B field is sent. The wireless communication terminal that receives the PPDU can identify the configuration of the entire MU PPDU by decoding the two HE-SIG-B fields. Specifically, the wireless communication terminal may Fig.24 The HE-SIG-B field is sent in the form shown in (b).

[0229] In a specific embodiment, the wireless communication terminal may indicate the wireless communication terminal corresponding to the per-user content by the identifier of the wireless communication terminal in the user-specific field of the HE-SIG-B field. At this time, the identifier of the wireless communication terminal may be an association identifier (AID). If a multi-BSSID set is used, the wireless communication terminal uses the assigned AID according to the group addressing AID allocation method in the multi-BSSID TIM operation, so that the PPDU can be broadcast to the wireless communication terminal included in any one of the multiple BSSs corresponding to the multiple BSSIDs. For example, there are N BSSs corresponding to a set of multiple BSSIDs, and each of the N BSSs may have one of the values ​​from 0 to N-1 as an AID. At this time, the wireless communication terminal can broadcast the PPDU to the wireless communication terminal of the BSS corresponding to AID 0 by specifying the wireless communication terminal identifier as 0 in the per-user content of the user-specific field. When using a multi-BSSID set, the wireless communication terminal can use a specific AID to broadcast the PPDU to the wireless communication terminals included in all BSSs corresponding to the multi-BSSID set. At this time, the specific AID may be an unassigned value in the multi-BSSID TIM operation. In a specific embodiment, the specific AID may be 2047.

[0230] Frames to be sent to multiple wireless communication terminals and frames to be sent to any one wireless communication terminal may be included in one MU PPDU. At this time, the multiple RUs to which the PPDU is sent may be divided into RUs for multiple wireless communication terminals and RUs for transmission to any one wireless communication terminal. When the wireless communication terminal receives the MU PPDU, the wireless communication terminal may determine whether the information corresponding to the wireless communication terminal is indicated by the per-user content or based on the wireless communication identifier included in the per-user content. At this time, the wireless communication terminal may determine whether the wireless communication terminal identifier indicates the wireless communication terminal based on the range of the wireless communication terminal indicated by the wireless communication terminal identifier. Specifically, the wireless communication terminal may be identified according to the wireless communication terminal identifier indicating a wireless communication terminal in a small range. For example, the HE-SIG-B field may include N wireless communication terminal identifiers from a wireless communication terminal identifier indicating a first group to a wireless communication terminal identifier indicating an Nth group. At this time, the first group includes a smaller number of wireless communication terminals than the second group, and the second group includes a smaller number of wireless communication terminals than the third group. In this case, the wireless communication terminal may confirm the wireless communication terminal identifier indicating the (N-1)th group according to the wireless communication terminal identifier indicating the (N)th group.

[0231] When using a multiple BSSID set, the wireless communication terminal may determine the wireless communication terminal identifier included in the HE-SIG-B field in the following order. When only the wireless communication terminal identifier indicating the wireless communication terminal is included in the per-user content, the wireless communication terminal may receive the payload of the PPDU sent via the RU indicated by the per-user content. When only the wireless communication terminal identifier indicating the wireless communication terminal is not included in the per-user content and the wireless communication identifier indicating the broadcast of the wireless communication terminal to the BSS associated with the wireless communication terminal is included in the per-user content, the wireless communication terminal may receive the payload of the PPDU sent via the RU indicated by the per-user content. Only the wireless communication terminal identifier indicating the wireless communication terminal is not included in the per-user content, the wireless communication identifier indicating the broadcast of the wireless communication terminal to the BSS associated with the wireless communication terminal is not included in the per-user content, and the wireless communication terminal identifier indicating the broadcast to the wireless communication terminal included in all BSSs may be included in the per-user content. At this time, the wireless communication terminal may receive the payload of the PPDU sent via the RU indicated by the per-user content including the wireless communication terminal identifier indicating the broadcast to the wireless communication terminal included in all BSSs. If all the above conditions are not met, the wireless communication terminal can stop decoding the corresponding PPDU. This is because the payload of the PPDU to be decoded by the wireless communication terminal is not included in the PPDU. For the convenience of explanation, the wireless communication terminal identifier is described in three ranges, but depending on the number or inclusion relationship of the wireless communication terminals, there may be more range types. In this case, as described above, the wireless communication terminal can determine the wireless communication terminal identifier according to the size of the range indicated by the wireless communication terminal identifier.

[0232] When a multi-BSSID set is not used, the wireless communication terminal may confirm the wireless communication terminal identifier included in the HE-SIG-B field in the following order. When only the wireless communication terminal identifier indicating the wireless communication terminal is included in the per-user content, the wireless communication terminal may receive the payload of the PPDU sent via the RU indicated by the per-user content. When only the wireless communication terminal identifier indicating the wireless communication terminal is not included in the per-user content and the wireless communication identifier indicating at least one of the broadcast, groupcast and multicast of the group including the wireless communication terminal is included in the per-user content, the wireless communication terminal may receive the payload of the PPDU sent via the RU indicated by the per-user content. Only the wireless communication terminal identifier indicating the wireless communication terminal is not included in the per-user content, the wireless communication identifier indicating at least one of the broadcast, groupcast and multicast of the group including the wireless communication terminal is not included in the per-user content, and the wireless communication terminal identifier indicating the broadcast to the wireless communication terminal included in the BSS may be included in the per-user content. At this time, the wireless communication terminal may receive the payload of the PPDU sent via the RU indicated by the per-user content including the wireless communication terminal identifier indicating the broadcast to the wireless communication terminal included in the BSS. If all the above conditions are not met, the wireless communication terminal can stop decoding the corresponding PPDU. This is because the payload of the PPDU to be decoded by the wireless communication terminal is not included in the PPDU. For the convenience of explanation, the wireless communication terminal identifier is described in three ranges, but depending on the number or inclusion relationship of the wireless communication terminals, there may be more range types. In this case, as described above, the wireless communication terminal can determine the wireless communication terminal identifier according to the size of the range indicated by the wireless communication terminal identifier.

[0233] In order for a wireless communication terminal that receives a MAC frame to effectively control the MAC frame, the wireless communication terminal may send information about MAC frame control through a MAC frame header. In this case, a method for efficiently sending information about MAC frame control is required. Fig.25 and Fig.33 Describe this.

[0234] Fig.25 is a view illustrating a MAC frame format according to an embodiment of the present invention.

[0235] The MAC frame may include a frame control field indicating information about frame control. In addition, the MAC frame may indicate a duration for NAV setting according to the frame type, or may include a duration / ID field indicating the AID of the wireless communication terminal that sends the frame. In addition, the MAC frame may include four address fields indicating information related to the address. In addition, the MAC frame may include a sequence control field indicating information about sequence control. In addition, the MAC frame may include a QoS control field indicating information about quality of service (QoS) control. In addition, the MAC frame may include a frame body field indicating the payload of the MAC frame. In addition, the MAC frame may include an FCS field indicating whether the MAC frame includes an error. Depending on the frame type or subtype, the MAC frame may not include the above fields. In addition, the MAC frame may include a frame control field, a duration / ID field, an address 1 field, and an FCS field regardless of the frame type and subtype.

[0236] Fig.26 is a view illustrating a variation of an HT Control field according to an embodiment of the present invention.

[0237] The wireless communication terminal may send and modify various HT control fields. Specifically, the wireless communication terminal may send the HT control field in the format of an HT variant, a VHT variant, or an HE variant. In addition, the HT control field may be a 32-bit field. At this time, the first bit B0 and the second bit B1 of the HT control field may indicate the type of the HT control field. When the first bit B0 of the HT control field is 0, the HT control field may be an HT variant. At this time, Fig.26 The bits below the second bit B1 of the HT Control field shown in FIG. 1 may include the HT Control Intermediate, AC Constraint, and RDG / More PPDU subfields. In addition, when the first bit B0 of the HT Control field is 1 and the second bit B1 is 0, the HT Control field may be a VHT variant. In this case, Fig.26 The bits below the second bit B1 of the HT Control field shown in FIG. 1 may include VHT Control Intermediate, AC Constraint, and RDG / More PPDU subfields. When the first difference B0 of the HT Control field is 1 and the second bit B1 is 1, the HT Control field may be a HE variant. At this time, as shown in FIG. Fig.26 The bits below the second bit B1 of the HT Control field shown in FIG. 1 may include an Aggregation Control (A-Control) subfield. The A-Control subfield may include control information. Figures 27 to 33 Describes the control information included in A-Control and the format of the A-Control subfield.

[0238] Fig. 27 The format of the A-Control subfield according to an embodiment of the present invention is shown.

[0239] According to an embodiment of the present invention, a wireless communication terminal may insert one or more control subfields into an A-Control subfield to transmit the A-Control subfield. At this time, depending on at least one of the type and subtype of the MAC frame, the number of control subfields included in the A-Control subfield may be applied differently. At this time, the A-Control subfield may include padding bits to match the length of the subfield. In a specific embodiment, the A-Control subfield may be a 30-bit field. In addition, the HE variant may be a 32-bit field. The A-Control subfield may include zero as a padding bit. The A-Control subfield may include control subfields continuously.

[0240] In addition, the control subfield may include a control ID subfield indicating the type of information included in the control subfield. In addition, the control subfield may include a control information subfield indicating control information. In a specific embodiment, the control ID field may be a 4-bit field. The content and length of the control information subfield may be determined based on the control ID subfield. Specifically, the A-Control subfield may have Fig. 27 (a). In addition, the control subfield included in the A-Control subfield may have the following format: Fig. 27 The format shown in (b).

[0241] The control subfield may include information related to at least one of UL MU response scheduling, receive operation mode indication, HE link adaptation, UL PPDU triggering, BlockACK request, and buffer status report request. When decoding the bit corresponding to the length of the A-Control subfield, the wireless communication terminal that decodes the control subfield can determine that there is no additional control information to be decoded. However, when the number of control subfields included in the A-Control subfield is variable and the length of the A-Control subfield remains unchanged, the wireless communication terminal that decodes the A-Control subfield may not be sure whether the current decoded bit is a padding bit or a control subfield. Therefore, a method is needed for a wireless communication terminal that decodes the A-Control subfield to determine whether the currently decoded bit is a padding bit.

[0242] The wireless communication terminal may insert the control subfield of the A-Control subfield into the A-Control subfield in their order according to the control ID arrangement. Specifically, the wireless communication terminal may insert the control subfield of the A-Control subfield into the A-Control subfield in ascending order of the control ID. In another specific embodiment, the wireless communication terminal may insert the control subfield of the A-Control subfield into the A-Control subfield in descending order of the control ID. When the control subfield is inserted into the A-Control subfield in the order in which they are sorted according to the control ID, the wireless communication terminal that decodes the A-Control subfield may determine the corresponding bit as a fill bit when the value of the control ID field in the A-Control subfield is continuously 0. In a specific embodiment, after the control ID subfield with 0 is decoded, when 0 is decoded again at a position corresponding to the control ID subfield, the wireless communication terminal that decodes the A-Control subfield may determine that there is no additional control information to be decoded. In addition, when 0 is decoded at a position corresponding to the control ID subfield opposite to the control ID sorting order, the wireless communication terminal decoding the control subfield can determine that there is no control information to be further decoded.

[0243] In another specific embodiment, the wireless communication terminal may indicate via a specific control ID subfield value that there is no control subfield after the corresponding field. At this time, when the control ID subfield with the specific control ID subfield value is decoded, the wireless communication terminal decoding the A-Control subfield may determine that there is no additional control information to be decoded.

[0244] Fig.28 FIG. 2 shows a format of an A-Control subfield of a control subfield according to another embodiment of the present invention.

[0245] The control subfield included in the A-Control subfield may include information indicating whether the corresponding control field is the last control subfield included in the A-Control subfield. Specifically, the information indicating whether the corresponding control field is the last control subfield included in the A-Control subfield may be a 1-bit field. In addition, the information indicating whether the corresponding control field is the last control subfield included in the A-Control subfield may be referred to as a control end field. In this embodiment, a wireless communication terminal that decodes the A-Control subfield may stop decoding the A-Control subfield based on the control end field. Specifically, when the control end field indicates that the corresponding control subfield is the last control subfield of the A-Control subfield, the wireless communication terminal that decodes the A-Control subfield may determine that there is no control information to be additionally decoded after the corresponding control subfield. Specifically, the format of the control subfield may be as follows. Fig.28 as shown in .

[0246] The length of the HE variant transmitted by the wireless communication terminal according to an embodiment of the present invention may be variable. This is because when the field of the HE variant is fixed, the wireless communication terminal may not be able to insert all necessary control information into the HE variant field. Figure 29 to Figure 32 Describe this.

[0247] Fig.29 The frame format and HE variant format of the HT Control field according to another embodiment of the present invention are shown.

[0248] Specifically, the wireless communication terminal may insert multiple HE variants into the HT control field to send the HT control field. At this time, the wireless communication terminal may insert a field indicating that there are more HE variants to be decoded in the HE variant. The field indicating that there are more HE variants may be referred to as a More A-Control subfield. For example, when the value of the More A-Control subfield is 1, the wireless communication terminal that decodes the HT control field may decode the subsequent bits into the HE variant after the corresponding HE variant. The More A-Control subfield may be placed in the last bit of the HE variant. In addition, the More A-Control subfield may be placed in the first bit of the A-Control subfield. In addition, the More A-Control subfield may be placed immediately after the two bits indicating the variant included in the A-Control subfield. In addition, the More A-Control subfield may be placed in front of the extended HE variant.

[0249] In a specific embodiment, the length of the A-Control subfield may be extended in units of 32 bits. In addition, even if the A-Control subfield is extended, the first bit B0 and the second bit B1 of the A-Control subfield indicating the variant included in the HT Control field may not be repeated. In addition, in a specific embodiment, the length of the HE variant added after the first HE variant may be 30 bits. The specific format of the HT Control field and the specific form of the HE variant may be as follows: Fig.29 as shown in .

[0250] Fig.30 The frame format and HE variant format of the HT Control field according to another embodiment of the present invention are shown.

[0251] When the HE Control subfield is an HE variant, the wireless communication terminal may insert a specific control ID value indicating the end of the HE variant. At this time, the wireless communication terminal that decodes the HE Control subfield may determine the end of the HE Control subfield by decoding the specific control ID value indicating the end of the HE variant. The format of the specific HE Control subfield may be as follows: Fig.30 as shown in .

[0252] Fig.31 The frame format and HE variant format of the HT Control field according to another embodiment of the present invention are shown.

[0253] When the length of the HE variant sent by the wireless communication terminal is variable, the wireless communication terminal can send the HE variant by inserting the above-mentioned control end field into the control subfield. The wireless communication terminal decoding the HT control field can determine the end of the HT control field based on the control end field. The format of the specific HE control subfield can be as follows: Fig.31 as shown in .

[0254] Fig.32 The frame format and HE variant format of the HT Control field according to another embodiment of the present invention are shown.

[0255] When the length of the HE variant sent by the wireless communication terminal is variable, the wireless communication terminal may insert a length subfield indicating the length of the A-Control field into the HE variant and send the HE subfield. Specifically, the length subfield may indicate -1, which is the number of control subfields following the length subfield. At this time, the length subfield may have the same number of bits as the control ID. In another specific embodiment, the length subfield may indicate the number of unit lengths extended by the A-Control subfield. For example, when the A-Control subfield is extended in bytes, the length subfield may indicate the total number of bytes of the A-Control subfield or the number of bytes of the extended A-Control subfield. In another specific embodiment, when the A-Control subfield is extended in units of 32 bits or 30 bits, the length subfield may indicate a value obtained by dividing the length of the extended A-Control subfield by 32 bits or 30 bits, or may indicate a value obtained by dividing the total length of the A-Control subfield by 32 bits or 30 bits.

[0256] Fig.33 The frame format and HE variant format of the HT Control field according to another embodiment of the present invention are shown.

[0257] The wireless communication terminal may send control information through the body of the frame. Specifically, the wireless communication terminal may send control information included in the A-Control field through the body of the frame. The total length of the MAC header or the length of the HT control field may be limited, and in this case, this is because there is control information that is required for the wireless communication terminal to receive the frame but is not included in the HT control. In a specific embodiment, the wireless communication terminal sends the control ID field through the HT control field and sends the control information field corresponding to the control ID field through the body of the frame. Specifically, the wireless communication terminal sends the control ID field corresponding to the specific value through the HT control field and sends the control information field corresponding to the control ID field through the body of the frame. In another specific embodiment, when the length of the control information field is greater than or equal to the reference value, the wireless communication terminal sends the control ID field through the HT control field and sends the control information field corresponding to the control ID field through the body of the frame. For example, when the length of the control information field is long, such as information about BlockAck or information about BlockAck request, the wireless communication terminal may send the control information field through the frame body. At this time, when multiple control ID fields are transmitted through the HT control field and multiple control information fields corresponding to the multiple control ID fields are transmitted through the frame body, the wireless communication terminal can insert the control information fields corresponding to the control ID fields into the frame body according to the sorting order of the control ID fields. Fig.33 In the embodiment of the HT Control field, there are control ID m and control ID m+1 in the HT Control field, and the wireless communication terminal inserts them into the HT Control field in the order of control ID m and control ID m+1. Since the length of control information corresponding to multiple control IDs is long, the wireless communication terminal inserts the control information corresponding to the control ID into the frame body. At this time, the wireless communication terminal inserts the control information into the frame body in the order of control information corresponding to control ID m and control information corresponding to control ID m+1.

[0258] In another specific embodiment, if the HT control field has a limited length, the wireless communication terminal sends the control ID field through the HT control field and sends the control information field corresponding to the control ID field through the body of the frame. In addition, the length of the HT control field can be fixed to 32 bits (4 bytes). In addition, the wireless communication terminal can send information indicating that the control information field corresponding to the control ID field is included in the body of the frame. In addition, the wireless communication terminal can send information indicating that the control information field corresponding to the control ID field is included in the body of the frame. In another specific embodiment, the wireless communication terminal can send information indicating the end of the control subfield. At this time, the information indicating the end of the control subfield can be a 1-bit field. At this time, the wireless communication terminal can be as in reference Figure 28 to Figure 32 The described embodiment also sends information indicating the end of the control subfield.

[0259] In these embodiments, a wireless communication terminal that receives the frame may obtain a control ID field in the HT Control field and obtain a control information field corresponding to the control ID field from the body of the frame.

[0260] Any one of the multiple wireless communication terminals can send a trigger frame for triggering transmission of the multiple wireless communication terminals to the multiple wireless communication terminals. At this time, the multiple wireless communication terminals can send a response frame to the trigger frame to the wireless communication terminal that sent the trigger frame based on the trigger frame. Through this operation, the multiple wireless communication terminals can send frames to one wireless communication terminal at the same time. Figures 34 to 44 Trigger frame based operations of a wireless communication terminal are described.

[0261] Fig.34 The format of a trigger frame according to an embodiment of the present invention is shown.

[0262] The trigger frame may include a frame control field indicating information about frame control. In addition, the trigger frame may include a duration / ID field indicating a duration for NAV setting. In addition, the trigger frame may include an RA field indicating a receiver address and a TA field indicating a sender address. When the trigger frame triggers multiple wireless communication terminals, the RA field may be a multicast address or a broadcast address indicating multiple wireless communication terminals. When the trigger frame triggers one wireless communication terminal, the RA field may indicate a MAC address of the corresponding wireless communication terminal. In addition, the trigger frame may include an FCS field indicating whether the trigger frame includes an error.

[0263] In addition, the trigger frame may include a common information field and one or more per-user information fields. The common information field may indicate information that is generally applied to multiple wireless communication terminals triggered by the trigger frame. The per-user information field may indicate information that is applied to each of the multiple wireless communication terminals triggered by the trigger frame. In this case, the number of per-user information fields may be determined based on the number of multiple wireless communication terminals triggered by the trigger frame. The trigger frame may include a padding field. In this case, the padding field may allow time for the wireless communication terminal that receives the trigger frame to process the trigger frame. The format of the specific trigger frame may be as follows: Fig.34 as shown in .

[0264] Fig.35 The formats of the common information field and the per-user information field of the trigger frame according to an embodiment of the present invention are shown.

[0265] The common information field may include the length of the triggered PPDU or the length field indicating the L-SIG length field of the triggered PPDU. At this time, the length field may be a 12-bit field. In addition, the common information field may include a cascade indication field, which indicates that there is a subsequent trigger frame after the trigger frame. The common information field may include a CS required field, which indicates whether channel sensing is required when sending a triggered PPDU. At this time, channel sensing may include virtual channel sensing and energy detection (ED) for determining whether NAV is set. In addition, the trigger frame may include a HE-SIG-A information field, which indicates the information to be inserted into the HE-SIG-A field of the triggered PPDU. At this time, the information that the wireless communication terminal receiving the trigger frame can recognize by itself can be omitted in the trigger frame. In addition, the trigger frame may include a CP and LTF type field, which indicates a combination of LTF and cyclic prefix (CP) based on the triggered PPDU. In addition, the trigger frame may include a trigger type field, which indicates the type of the trigger frame. At this time, the type of the trigger frame may indicate any one of a basic trigger, a beamforming report, a polling trigger, a MU-BAR, and a MU-RTS. In addition, the trigger frame may include a trigger-related common information field whose format is determined according to the trigger type. The specific form of the common information field may be the same as Fig.35 The same form as shown in (a).

[0266] The per-user information field may include a user identifier field, which indicates the wireless communication terminal corresponding to the per-user information. At this time, the user identifier field may indicate the AID of the wireless communication terminal corresponding to the per-user information. In addition, the per-user information field may include an RU allocation field, which indicates information about the RU allocated to the wireless communication terminal corresponding to the user identifier field. In addition, the per-user information field may include a coding type field, which is used by the corresponding wireless communication terminal when the wireless communication terminal corresponding to the user identifier field sends a triggered PPDU. Specifically, the coding type field may indicate BCC or LDPC. In addition, when the wireless communication terminal corresponding to the user identifier field sends a triggered PPDU, the per-user information field may include a DCM field, which indicates whether the corresponding wireless communication terminal uses dual carrier modulation (DCM). In addition, the per-user information field may include an SS allocation field, which indicates the spatial stream to be used by the wireless communication terminal when the wireless communication terminal corresponding to the user identifier field sends a triggered PPDU. In addition, the per-user information field may include a trigger-related per-user information field whose format is determined according to the type of trigger frame. Specifically, the format of the per-user information field may be the same as Fig.35The format is the same as shown in (b).

[0267] Fig.36 The common information field and the per-user information field of the trigger frame according to another embodiment of the present invention are shown.

[0268] When a wireless communication terminal triggered by a trigger frame sends a triggered PPDU, the common information field may include a spatial reuse field, which indicates the value of the spatial reuse field to be inserted by the corresponding wireless communication terminal in the HE-SIG-A field of the PPDU. In addition, when a wireless communication terminal triggered by a trigger frame sends a triggered PPDU, the common information field may include a BW field, which indicates the value to be inserted by the corresponding wireless communication terminal in the BW field of the HE-SIG-A. In addition, when a wireless communication terminal triggered by a trigger frame sends a triggered PPDU, the common information field may include a MU MIMO LTF mode field, which indicates the MU MIMO LTF mode to be used by the corresponding wireless communication terminal. In addition, when a wireless communication terminal triggered by a trigger frame sends a triggered PPDU, the common information field may include an LTF number field, which indicates the number of LTFs to be used by the corresponding wireless communication terminal. In addition, when a wireless communication terminal triggered by a trigger frame sends a triggered PPDU, the common information field may include an STBC field, which indicates whether the wireless communication terminal uses STBC. In addition, when a wireless communication terminal triggered by a trigger frame sends a triggered PPDU, the common information field may include an LDPC additional symbol field, which indicates whether an LDPC additional symbol exists when the corresponding wireless communication terminal is used. In addition, when a wireless communication terminal triggered by a trigger frame sends a triggered PPDU, the common information field may include an AP TX power field, which indicates the transmission power to be used by the wireless communication terminal. In addition, when a wireless communication terminal triggered by a trigger frame sends a triggered PPDU, the common information field may include a packet extension field, which indicates information about the packet extension of the PPDU sent by the corresponding wireless communication terminal. Other fields included in the common information field may be the same as those in the reference. Fig.35 (a) is the same as the embodiment described in the previous section. Specifically, the public information field can be Fig.35 The same as the embodiment of (a).

[0269] When the wireless communication terminal corresponding to the user identifier field transmits a trigger-based PPDU, the per-user information field or the target RSSI field may include an RSSI field indicating an RSSI value to be targeted by the wireless communication terminal.

[0270] Fig.37 The trigger-related common information field and the trigger-related per-user information field of the MU-BAR type trigger frame according to an embodiment of the present invention are shown.

[0271] A wireless communication terminal as an AP can send data frames to multiple wireless communication terminals and request the transmission of ACK frames for corresponding data frames. Specifically, the wireless communication terminal as an AP can trigger the transmission of ACK frames of multiple wireless communication terminals through a trigger frame. At this time, the trigger frame type can be a MU-BAR type.

[0272] In addition, when a wireless communication terminal as an AP sends a multicast frame to multiple wireless communication terminals and one of the non-AP wireless communication terminals fails to receive the multicast frame, a multicast retry (GCR) BlockACK may be sent. At this time, the wireless communication terminal as an AP may trigger the GCR BlockACK transmission of multiple wireless communication terminals through a trigger frame. To this end, the common information field of the trigger frame may include information related to the GCR. At this time, the trigger frame type may be a MU-BAR type or a MU-BAR type for GCR. Specifically, when the type of the trigger frame is a MU-BAR type or a MU-BAR type for GCR, the common information field of the trigger frame may include a GCR indication field, which indicates whether the trigger frame is a MU-BAR for GCR. In addition, the common information field of the trigger frame may include a GCR address field, which indicates the address of the GCR group triggered by the trigger frame. Specifically, the common information field included in the trigger frame of the MU-BAR type may be the same as Fig.37 The same as the embodiment of (a).

[0273] In addition, the trigger-related per-user information field of the trigger frame may include a BAR control field, which includes information about the BAR frame control. In addition, the trigger-related per-user information field of the trigger frame may include a BAR information field, which includes information about the BAR frame. In this specific embodiment, the BAR control field and the BAR information field may be the same format as the trigger frame of the BlockAckReq type. In another specific embodiment, the BAR control field and the BAR information field may be a structure in which one or more fields are omitted from the field format of the trigger frame of the BlockAckReq type. For example, the wireless communication terminal can use the MU-BAR type or MU-BAR type trigger frame for GCR by omitting the information included in the trigger-related public information of the BlockAckReq type trigger frame. Specifically, the wireless communication terminal inserts the GCR indication field in the trigger-related public information of the BlockAckReq type trigger frame and omits the GCR indication field in the BAR control field. In another specific embodiment, the wireless communication terminal can insert the GCR address field in the trigger-related public information field and omit the GCR address field in the BAR information field. In another specific embodiment, even when the wireless communication terminal requests a GCR BlockAck, the wireless communication terminal inserts a GCR address field in the trigger-related common information field and omits the GCR address field in the BAR information field.

[0274] Fig.38 The format of the trigger-related common information field of the MU-BAR type trigger frame according to an embodiment of the present invention is shown.

[0275] In a specific embodiment of the present invention, when the type of the trigger frame is a MU-BAR type or a MU-BAR type for GCR, the trigger-related public information field of the trigger frame may include only a GCR address field. At this time, the wireless communication terminal may set the value of the GCR address field to a predetermined value and indicate that it is not a MU-BAR type trigger frame for GCR. Specifically, the predetermined value may be zero. The wireless communication terminal that receives the trigger frame may determine whether the corresponding trigger frame is a MU-BAR type trigger frame for GCR based on the value of the GCR address field. Specifically, the wireless communication terminal that receives the trigger frame may determine whether the corresponding trigger frame is a MU-BAR type trigger frame for GCR based on whether the value of the GCR address field is a predetermined value.

[0276] In another specific embodiment, the wireless communication terminal may indicate that the MU-BAR trigger frame is a MU-BAR type trigger frame for GCR by a starting sequence control value or TID value requested by MU-BAR. At this time, the wireless communication terminal receiving the trigger frame may determine whether the trigger frame is a MU-BAR type trigger frame for GCR by a starting sequence control value or TID value requested by MU-BAR.

[0277] In addition, even if the wireless communication terminal receiving the trigger frame corresponds to the address indicated by the GCR address field, when the STA identifier field in the per-user information field does not indicate the wireless communication terminal receiving the trigger frame, the wireless communication terminal receiving the trigger frame can also determine that the transmission is not triggered by GCR BlockACK.

[0278] The format of the trigger-related common information field of a specific MU-BAR type trigger frame can be the same as Fig.38 The same as the embodiment.

[0279] Fig.39 A format of a MU-BAR type trigger frame for GCR according to an embodiment of the present invention is shown.

[0280] The wireless communication terminal may set the RA field of the MU-BAR type trigger frame for GCR to the GCR address. Specifically, the wireless communication terminal may set the RA field of the trigger frame to the GCR address and indicate that the type of the trigger frame is the MU-BAR type for GCR. Therefore, the wireless communication terminal may omit the GCR address field in the common information field. In another specific embodiment, the wireless communication terminal may not set a value in the GCR address field in the common information field. In addition, when the wireless communication terminal sets the RA field of the MU-BAR type trigger frame for GCR to the GCR address, the wireless communication terminal may only insert information about the wireless communication terminal corresponding to the GCR address in the per-user information field of the trigger frame. The specific trigger frame format may be the same as Fig.39 The same as the embodiment.

[0281] Fig.40 A format of a MU-BAR type trigger frame for GCR according to an embodiment of the present invention is shown.

[0282] The wireless communication terminal can set the RA field of the MU-BAR type trigger frame for GCR to the broadcast address. At this time, the wireless communication terminal can set the GCR address field to the GCR address in the public information field. In addition, when the wireless communication terminal sets the RA field of the MU-BAR type trigger frame for GCR to the broadcast address, the wireless communication terminal can request an ACK frame other than GCR BlockACK to GCR BlockACK via the corresponding trigger frame. Therefore, when the wireless communication terminal sets the RA field of the MU-BAR type trigger frame for GCR to the broadcast address, the wireless communication terminal can insert information about the wireless communication terminal corresponding to the GCR address and information about the wireless communication terminal not corresponding to the GCR address in the per-user information field of the trigger frame. The specific trigger frame format can be the same as Fig.40 The same as the embodiment.

[0283] Fig.41 The format of the BAR control field and the encoded values ​​of the BlockACKReq variant according to an embodiment of the present invention are shown.

[0284] As described above, when the trigger frame is of MU-BAR type, the trigger-related per-user information field of the trigger frame may include a BAR control field. At this time, a plurality of bits included in the trigger-related per-user information field may indicate a variant of BlockACKReq. Specifically, the multi-TID subfield, the compression bitmap subfield, and the GCR subfield included in the trigger-related per-user information field may indicate a variant of BlockACKReq. For example, when the value of the Multi-TID subfield is 0, the value of the compression bitmap subfield is 1, and the value of the GCR subfield is 1, the type of the trigger frame may be GCR BlockACKReq.

[0285] As described above, when a MU-BAR type trigger frame requests a GCR BlockAck, the MU-BAR type trigger frame may request a GCR BlockAck frame and another ACK frame together. Specifically, the wireless communication terminal may request ACKs for multiple TIDs from the wireless communication terminal that has received the trigger frame through the MU-BAR type trigger frame. In a specific embodiment, the wireless communication terminal may request ACKs for multiple TIDs including a GCR BlockACK frame from the wireless communication terminal that has received the trigger frame through the MU-BAR type trigger frame. For example, the wireless communication terminal may set the Multi-TID Saab field to 1, set the GCR subfield to 1, request a GCR BlockAck, and request an ACK for another TID together. At this time, the value of the compression bitmap subfield may be 0 or 1. In a specific embodiment, the format of the BAR control field may be the same as Fig.41(a). Alternatively, the encoded value of the BlockACKReq variant may be Fig.41 As shown in (b).

[0286] When the trigger frame requests a GCR BlockAck frame and another ACK frame together, the wireless communication terminal may send a multi-TID BlockACK frame in response to the trigger frame. In addition, when the trigger frame requests a GCR BlockAck frame and another ACK frame together, the wireless communication terminal may send a BlockACK frame for multiple TIDs together with other MPDUs. Specifically, the wireless communication terminal may send a BlockACK frame and another MPDU for multiple TIDs through an A-MDPU. At this time, the BlockACK frame may be a compressed BlockACK frame.

[0287] Fig.42 The format of the BAR information field according to an embodiment of the present invention is shown.

[0288] As described above, when the type of the trigger frame is the MU-BAR type, the trigger-related user information field may include a BAR information field. At this time, the BAR information field includes a block ACK start sequence control field and may not include a GCR address field. In particular, even when the type of the trigger frame is the MU-BAR type for GCR, the BAR information field includes a block ACK start sequence control field and may not include a GCR address field. In addition, when the type of the trigger frame is the MU-BAR type, the common information field may include a GCR address field. Specifically, when the type of the trigger frame is the MU-BAR type, the trigger-related common information field may include a GCR address field. This is because the GCR address field is information commonly applied to multiple wireless communication terminals, through which the GCR BlockACK transmission is triggered via the MU-BAR. Specifically, the format of the BAR information field may be the same as Fig.42 The same as the embodiment.

[0289] Fig.43 A BAR information field according to another embodiment of the present invention is shown.

[0290] When the type of the trigger frame is a MU-BAR type and the wireless communication terminal requests ACK for multiple TIDs, the wireless communication terminal may generate and send a BAR information field classified by TID. Specifically, when the type of the trigger frame is a MU-BAR type for GCR and the wireless communication terminal requests ACK for multiple TIDs, the wireless communication terminal may generate and send a BAR information field for each TID. At this time, the BAR information field may include a per-TID information field and a block ACK start sequence field by TID. At this time, the per-TID information field may include a TID subfield indicating the TID. For example, the specific format of the BAR information field may be the same as Fig.43 The same as the embodiment of the present invention. The length of the BAR information field may vary depending on the number of TIDs requesting ACK. Specifically, the length of the trigger-related per-user information field may vary depending on the number of TIDs requesting ACK. Therefore, the length of the per-user information field may vary depending on the number of TIDs requesting ACK. The wireless communication terminal sending the trigger frame may signal the number of TIDs through the TID_INFO field of the BAR control field of the trigger frame. The wireless communication terminal receiving the trigger frame may determine the length of the per-user information field based on the TID_INFO field of the BAR control field of the trigger frame.

[0291] Fig.44 A trigger frame structure according to another embodiment of the present invention is shown.

[0292] The trigger frame can have Fig.34 In this case, the format of the common information field and the per-user information field can be the same as that of the reference Figure 35 to Figure 36 In addition, the format of the trigger-related per-user information field can be the same as that of the reference Fig.37 In addition, the format of the trigger-related public information field can be the same as that of the reference Fig.37 and Fig.38 In addition, the format of the BAR information field can be the same as that of the reference Fig.43 The described embodiments are the same.

[0293] Fig.45 The operation of the wireless communication terminal according to the embodiment of the present invention is shown.

[0294] The wireless communication terminal receives PPDU (S4501).

[0295] The wireless communication terminal identifies whether the PPDU is an inter-BSS PPDU or an intra-BSS PPDU (S4503). In addition, when the PPDU received by the wireless communication terminal is not identified as an inter-BSS PPDU or an intra-BSS PPDU, this may be a case where the received PPDU lacks information for determining the BSS that sent the received PPDU. As described above, the wireless communication terminal can identify whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on the MAC header of the MAC frame included in the PPDU. When a wireless communication terminal as an AP receives a trigger-based PPDU from a wireless communication terminal that is not triggered by the wireless communication terminal as an AP, the wireless communication terminal as an AP can identify the corresponding PPDU as an inter-BSS PPDU. In a specific embodiment, when the wireless communication terminal as an AP does not send a trigger frame but receives a trigger-based PPDU, the wireless communication terminal as an AP can identify the PPDU as an inter-BSS PPDU. In addition, based on whether the received PPDU includes a trigger frame, the wireless communication terminal as an AP can determine whether the corresponding PPDU is a PPDU for downlink transmission. Specifically, the wireless communication terminal as an AP can identify whether the corresponding PPDU is an inter-BSS PPDU based on the SR related information. At this time, the SR related information can be the SR field signaled by the above-mentioned PPDU. The wireless communication terminal can identify whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU through at least one of the above conditions.

[0296] In addition, when the PPDU received by the wireless communication terminal satisfies both the inter-BSS PPDU condition and the intra-BSS PPDU condition, the wireless communication terminal can identify whether the corresponding PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on conditions other than the BSS color. As described above, this is because the BSS color value may have a BSS color conflict due to value restrictions. In a specific embodiment, the wireless communication terminal can identify the BSS color value based on the reference color. Figures 6 to 23 The described embodiments identify whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU. Specifically, when the PPDU received by the wireless communication terminal satisfies both the inter-BSS PPDU condition and the intra-BSS PPDU condition, the wireless communication terminal may identify the corresponding PPDU as an inter-BSS PPDU.

[0297] The wireless communication terminal may perform operations related to channel access according to whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU. In addition, the wireless communication terminal may enter a power saving mode (S4505) depending on whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU. At this time, the operations related to channel access may include at least one of an operation for setting a CCA threshold and an operation for setting / resetting NAV.

[0298] In addition, when the PPDU received by the wireless communication terminal may not be identified as an inter-BSS PPDU or an intra-BSS PPDU, the following operations may be performed. When the PPDU received by the wireless communication terminal is not identified as an inter-BSS PPDU or an intra-BSS PPDU, the wireless communication terminal may regard the PPDU as an inter-BSS PPDU. Specifically, when the PPDU received by the wireless communication terminal is not identified as an inter-BSS PPDU or an intra-BSS PPDU, the wireless communication terminal may set a basic NAV based on the received PPDU. For example, when the PPDU received by the wireless communication terminal may not be identified as an inter-BSS PPDU or an intra-BSS PPDU, the wireless communication terminal may set a basic NAV based on the TXOP duration field indicated by the HE-SIG-A field of the corresponding PPDU.

[0299] When a PPDU received by the wireless communication terminal may not be recognized as an inter-BSS PPDU or an intra-BSS PPDU, the wireless communication terminal may not enter the power save mode based on the BSS color signaled through the PPDU.

[0300] When the BSS of the PPDU that sets the currently set NAV is the same as the BSS of the CF-End frame, the wireless communication terminal may reset the currently set NAV. Additionally, when the BSS of the PPDU that sets the currently set NAV is different from the BSS of the CF-End frame, the wireless communication terminal may not reset the NAV.

[0301] In addition, when the NAV is set by a PPDU in which it is impossible to identify whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU, the wireless communication terminal may not reset the NAV based on a CF-End frame sent from within the BSS or a CF-End frame sent from a BSS corresponding to a multi-BSSID set including a BSSID corresponding to the BSS of the wireless communication terminal.

[0302] The situation where the PPDU received by the wireless communication terminal may not be identified as an inter-BSS PPDU or an intra-BSS PPDU may be the following situation: due to the BSS color conflict, it may not be possible to identify whether the PPDU received by the wireless communication terminal based on the BSS color is an inter-BSS PPDU or an intra-BSS PPDU. If the wireless communication terminal cannot identify whether the PPDU received based on the BSS color is an inter-BSS PPDU or an intra-BSS PPDU, the wireless communication terminal may not operate on the basis of the BSS color signaled by the received PPDU. Specifically, if the wireless communication terminal cannot identify whether the PPDU received based on the BSS color is an inter-BSS PPDU or an intra-BSS PPDU, the wireless communication terminal may not set the intra-BSS NAV based on the BSS color and the TXOP duration field signaled by the HE-SIG-A field of the received PPDU. Specifically, when the wireless communication terminal identifies the BSS color conflict, the wireless communication terminal may not set the intra-BSS NAV based on the TXOP duration field indicated by the HE-SIG-A field. When the wireless communication terminal receives signaling information indicating that the BSS color-based operation is not allowed, the wireless communication terminal may not set the intra-BSS NAV based on the BSS color and the TXOP duration field of the HE-SIG-A field of the PPDU.

[0303] In addition, when the wireless communication terminal cannot identify whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on the BSS color, the wireless communication terminal can set the basic NAV based on the BSS color and the TXOP duration field signaled by the HE-SIG-A field of the received PPDU. Specifically, when the wireless communication terminal identifies a BSS color conflict, the wireless communication terminal can set the basic NAV based on the TXOP duration field indicated by the HE-SIG-A field. When the wireless communication terminal receives signaling information indicating that operations based on BSS color are not allowed, the wireless communication terminal can set the basic NAV based on the BSS color and the TXOP duration field of the HE-SIG-A field of the PPDU.

[0304] Specifically, if the wireless communication terminal cannot identify whether the PPDU received based on the BSS color is an inter-BSS PPDU or an intra-BSS PPDU, the wireless communication terminal may not enter the power saving mode based on the BSS color signaled by the HE-SIG-A field of the received PPDU.

[0305] In addition, when the PPDU received by the wireless communication terminal may not be identified as an inter-BSS PPDU or an intra-BSS PPDU, this may be a case where the received PPDU lacks information for determining the transmitted BSS. Specifically, when the PPDU received by the wireless communication terminal is not identified as an inter-BSS PPDU or an intra-BSS PPDU, the wireless communication terminal may not decode the MAC header of the MAC frame included in the PPDU. In addition, the case where the PPDU received by the wireless communication terminal is not identified as an inter-BSS PPDU or an intra-BSS PPDU may be a case where it may not be possible to identify whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU according to the various methods described above.

[0306] In addition, the wireless communication terminal may send a PPDU by including signaling information indicating that the operation based on the BSS color is not allowed in the signaling field of the PPDU. At this time, the wireless communication terminal that receives the PPDU including the corresponding signaling information may not perform the operation based on the BSS color. In a specific embodiment, the wireless communication terminal may send the BSS color value indicated by it by setting the signaling field of the PPDU to a predetermined value. At this time, the predetermined value may be a reserved value that is not used in the BSS color when the BSS color is selected by the AP. For example, the predetermined value may be zero. In addition, when the wireless communication terminal receives a PPDU indicating a predetermined value as the BSS color, the wireless communication terminal may not perform an operation based on the BSS color. Specifically, when the wireless communication terminal receives a PPDU indicating a predetermined value in the BSS color, the wireless communication terminal may not perform an SR operation on the corresponding PPDU. In a specific embodiment, when the wireless communication terminal receives a PPDU indicating a predetermined value in the BSS color, the wireless communication terminal may regard the PPDU as a PPDU within the BSS. Therefore, when the wireless communication terminal receives a PPDU indicating a predetermined value in the BSS color, the wireless communication terminal may not discard the corresponding PPDU.

[0307] As described above, a wireless communication terminal may send a BSS color indicating a BSS including the wireless communication terminal when communicating with another wireless communication terminal. At this time, when the wireless communication terminal does not receive information for signaling the BSS color, the wireless communication terminal may send a predetermined value as the BSS color. At this time, the predetermined value may be a reserved value that is not used in the BSS color when the BSS color is selected by the AP. For example, the predetermined value may be zero. Specifically, when the wireless communication terminal does not receive information for signaling the BSS color, the non-AP wireless communication terminal may send a predetermined value as the BSS color when communicating with other wireless communication terminals. In a specific embodiment, if the wireless communication terminal does not receive information for signaling the BSS color, the wireless communication terminal may set the BSS color value signaled by the PPDU sent by the wireless communication terminal to a predetermined value. In addition, when the wireless communication terminal does not receive information for signaling the BSS color, the wireless communication terminal may set the BSS color value signaled by the frame sent by the wireless communication terminal to a predetermined value. When the wireless communication terminal does not receive information for signaling the BSS color, there is no BSS color. Specifically, when the wireless communication terminal does not receive information signaling for the BSS color, the wireless communication terminal may not be associated with any AP. In addition, the case where the wireless communication terminal does not receive the information for signaling the BSS color may include the following case: the wireless communication terminal fails to establish a tunnel direct link setup (TDLS) link, a direct link setup (DLS) link, or an IBSS (independent) membership. In addition, the case where the wireless communication terminal does not receive the information for signaling the BSS color may include the following case: the wireless communication terminal may not receive information about the changed BSS color value after receiving information indicating that an operation based on the BSS color value is not allowed. In addition, the PPDU that signals a predetermined value as the BSS color may not be identified as an inter-BSS PPDU or an intra-BSS PPDU based on the predetermined value of the BSS color.

[0308] In a specific embodiment, when the wireless communication terminal does not receive the HE operation element, the wireless communication terminal may set the BSS color value included in the PPDU sent by the wireless communication terminal to a predetermined value. For example, the wireless communication terminal may use a predetermined value as the BSS color value when sending a probe request frame. Specifically, when the wireless communication terminal sends a probe request frame, the wireless communication terminal may set the value of the BSS color field included in the HE operation element to a predetermined value. In addition, when the wireless communication terminal sends a probe request frame, the value of the BSS color field of the HE-SIG-A field of the PPDU including the probe request frame may be set to a predetermined value.

[0309] At this time, when the wireless communication terminal receives a PPDU indicating a predetermined value as a BSS color, the wireless communication terminal may not perform an operation based on the BSS color. Specifically, when the wireless communication terminal receives a PPDU indicating a predetermined value as a BSS color, the wireless communication terminal may not perform an SR operation on the corresponding PPDU. In a specific embodiment, when the wireless communication terminal receives a PPDU indicating a predetermined value as a BSS color, the wireless communication terminal may regard the PPDU as a PPDU within the BSS. Therefore, when the wireless communication terminal receives a PPDU indicating a predetermined value as a BSS color, the wireless communication terminal may not discard the corresponding PPDU.

[0310] When the wireless communication terminal accesses a channel or enters a power saving mode, the specific operation of the wireless communication terminal can be the same as that of Figures 6 to 23 The embodiments of the described embodiments are identical.

[0311] Although the present invention is described by using wireless LAN communication as an example, the present invention is not limited thereto and can be applied to other communication systems such as cellular communication. Additionally, although the method, device and system of the present invention are described together with specific embodiments of the present invention, some or all of the components or operations of the present invention can be implemented using a computer system with a general hardware architecture.

[0312] The features, structures and effects described in the above embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. In addition, those skilled in the art can combine or modify the features, structures and effects shown in each embodiment in other embodiments. Therefore, it should be understood that the content related to this combination and modification is included in the scope of the present invention.

[0313] Although the present invention is mainly described based on the above embodiments but not limited thereto, it will be appreciated by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention. For example, each component specifically shown in the embodiment may be modified and implemented. It should be understood that the differences associated with such modifications and applications are included within the scope of the present invention as defined in the appended claims.

Claims

1. A wireless communication station, the station comprising: Transceiver; as well as processor, wherein the processor is configured to receive a physical layer convergence procedure (PLCP) protocol data unit (PPDU) by using the transceiver, and When the signaling information indicates that the operation based on the basic service set BSS color is not allowed, the intra-BSS network allocation vector NAV is not set by using the BSS color indicated by the signaling field of the PPDU, Wherein, the BSS color is an identifier of the BSS, The BSS color of the BSS to which the station belongs is set by the access point to which the station is associated, The signaling information is sent from the access point. The intra-BSS NAV is different from the basic NAV and is a NAV set based on the intra-BSS PPDU. The basic NAV is set based on the inter-BSS PPDU or the PPDU that cannot be identified as the inter-BSS PPDU or the intra-BSS PPDU.

2. The station according to claim 1, wherein The PPDU comprises a medium access control (MAC) frame, wherein the signaling field of the PPDU comprises a transmission opportunity (TXOP) duration field, wherein the MAC frame comprises a duration field, The TXOP duration field indicates information for setting the NAV within the BSS and the basic NAV. The duration field indicates information for setting the NAV within the BSS and the basic NAV. The processor is configured to, when the station obtains a valid signaling field of the MAC frame, not use a TXOP duration field for setting the intra-BSS NAV or the basic NAV.

3. The station according to claim 1, wherein: The processor is configured to, when the station identifies that a BSS color conflict has occurred, signal that operations based on the BSS color are not permitted, The BSS color conflict indicates that different BSSs correspond to one BSS color.

4. The station according to claim 3, wherein: The processor is configured to determine that the BSS color conflict has occurred based on an address field of a medium access control MAC frame.

5. The station according to claim 1, wherein The operation based on the BSS color includes entering a sleep state of power saving operation based on the BSS color indicated by a signaling field of the PPDU, The power saving operation is an operation for the station to enter a sleep state until the received PPDU as the intra-BSS PPDU is terminated.

6. The station according to claim 1, wherein: The processor is configured to not perform a spatial reuse operation when the BSS color indicated by the signaling field of the PPDU is a predetermined value.

7. The station according to claim 6, wherein: The predetermined value is 0.

8. A method for operating a wireless communication station, the method comprising: Receive physical layer convergence process PLCP protocol data unit PPDU; as well as When the signaling information indicates that the operation based on the basic service set BSS color is not allowed, the operation based on the BSS color is not performed, Wherein, the BSS color is an identifier of the BSS, The BSS color of the BSS to which the station belongs is set by the access point to which the station is associated, The signaling information is sent from the access point. wherein, when the signaling information indicates that the BSS color-based operation is not allowed, the intra-BSS network allocation vector NAV is not set by using the BSS color indicated by the signaling field of the PPDU, The intra-BSS NAV is different from the basic NAV and is a NAV set based on the intra-BSS PPDU. The basic NAV is set based on the inter-BSS PPDU or the PPDU that cannot be identified as the inter-BSS PPDU or the intra-BSS PPDU.

9. The method according to claim 8, wherein: The PPDU comprises a medium access control (MAC) frame, wherein the signaling field of the PPDU comprises a transmission opportunity (TXOP) duration field, wherein the MAC frame comprises a duration field, The TXOP duration field indicates information for setting the NAV within the BSS and the basic NAV. The duration field indicates information for setting the NAV within the BSS and the basic NAV. The method further includes not using a TXOP duration field for setting the intra-BSS NAV or the basic NAV when the station obtains a valid signaling field of the MAC frame.

10. The method according to claim 8, wherein: The method further includes, when a station identifies that a BSS color conflict has occurred, signaling that operations based on the BSS color are not allowed, The BSS color conflict indicates that different BSSs correspond to one BSS color.

11. The method according to claim 10, wherein: Signaling that the BSS color conflict has occurred includes determining that the BSS color conflict has occurred based on an address field of a media access control MAC frame.

12. The method according to claim 8, wherein: The operation based on the BSS color includes entering a sleep state of power saving operation based on the BSS color indicated by a signaling field of the PPDU, The power saving operation is an operation for the station to enter the sleep state until the received PPDU as the intra-BSS PPDU is terminated.

13. The method according to claim 8, wherein: The method further includes not performing a spatial reuse operation when the BSS color indicated by a signaling field of the PPDU is a predetermined value.

14. The method according to claim 13, wherein: The predetermined value is 0.

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