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 for performing wireless communication, the wireless communication terminal comprising: 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. An intra-BSS PPDU indicates a PPDU transmitted from the same BSS as the BSS including the wireless communication terminal, and an inter-BSS PPDU indicates a PPDU transmitted 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 the application number 201780015247.2 (PCT / KR2017 / 002407), international filing date of March 6, 2017, and invention title of "Wireless communication method and wireless communication terminal in a basic service set overlapping with another basic service set", which was filed with the Chinese Patent Office on September 4, 2018. Technical Field

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

[0003] In recent years, with the expansion of the supply of mobile devices, wireless communication technologies that can provide fast wireless Internet services to mobile devices have attracted significant public attention. Wireless communication technologies allow mobile devices including smart phones, smart tablets, laptop computers, portable multimedia players, embedded devices, etc. to wirelessly access the Internet in a home or company or a specific service providing area.

[0004] One of the most well-known wireless communication technologies is wireless LAN technology. Since the initial wireless LAN technology was supported using a frequency of 2.4 GHz, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 has commercialized or developed various technical standards. First, IEEE 802.11b supports a communication speed of up to 11 Mbps when using a frequency in the 2.4 GHz band. IEEE 802.11a, which was commercialized after IEEE 802.11b, uses a frequency in the 5 GHz band instead of the 2.4 GHz band, reduces the impact of interference compared to the significantly congested frequency in the 2.4 GHz band, and increases the communication speed up to 54 Mbps by using orthogonal frequency division multiplexing (OFDM) technology. However, IEEE 802.11a has a disadvantage in that the communication distance is shorter than that of IEEE 802.11b. In addition, IEEE 802.11g uses a frequency in the 2.4 GHz band similar to IEEE 802.11b to achieve a communication speed of up to 54 Mbps and satisfies backward compatibility to attract significant public attention, 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. The purpose of IEEE 802.11n is to increase the speed and reliability of the network and extend the working distance of the wireless network. More specifically, IEEE 802.11n supports high throughput (HT) with a data processing speed of up to 540 Mbps or higher, and further, multiple-input multiple-output (MIMO) technology that uses multiple antennas on both sides of the transmitting unit and the receiving unit based on multiple antennas in order to minimize transmission errors and optimize data speed. In addition, the standard can use a coding scheme that sends multiple overlapping copies of each other in order to improve data reliability.

[0006] As the supply of wireless LAN has become active and further, the applications using wireless LAN have become diversified, the need for a new wireless LAN system that supports a throughput (very high throughput (VHT)) higher than the data processing speed supported by IEEE 802.11n has drawn public attention. Among them, IEEE 802.11ac supports a wide bandwidth (80 to 160 MHz) in the 5 GHz frequency band. The IEEE 802.11ac standard is only defined within the 5 GHz frequency band, but the initial 11ac chipset will even support operation in the 2.4 GHz frequency band for backward compatibility with existing 2.4 GHz frequency band products. Theoretically, according to this standard, the wireless LAN speed of multiple stations can reach up to 1 Gbps at maximum and the maximum single-link speed can reach up to 500 Mbps at maximum. This is achieved by expanding the concept of the wireless interface accepted by 802.11n, such as a wider wireless frequency bandwidth (up to 160 MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high-density modulation (up to 256QAM). In addition, as a scheme for transmitting data by using the 60 GHz frequency 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 speed of up to 7 Gbps by using beamforming technology and is suitable for the transmission of high-bitrate moving image streams such as mass data or uncompressed HD video. However, because the 60 GHz frequency band is difficult to pass through obstacles, the disadvantage is that the 60 GHz frequency band can only be used between devices within 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 have been continuously carried out. That is to say, 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 this 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 the bandwidth by simultaneously transmitting data between multiple terminals and a basic terminal. SUMMARY OF THE INVENTION

[0009] TECHNICAL PROBLEM

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

[0011] TECHNICAL SOLUTION

[0012] According to an embodiment of the present invention, a wireless communication terminal communicating wirelessly includes: a transceiver; and a processor. The processor is configured to transmit, when communicating with another wireless communication terminal through the transceiver, an indication of a BSS color of a BSS including the wireless communication terminal, and to transmit 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 acting as an AP, the processor may transmit a predetermined value as the BSS color.

[0014] When the wireless communication terminal receives signaling information indicating that an operation based on the BSS color is not allowed, 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) signaling the predetermined value as the BSS color may not be recognized as an inter-BSS PPDU or an intra-BSS PPDU based on the BSS color being the predetermined value, where an intra-BSS PPDU may indicate a PPDU transmitted from the same BSS as the BSS including the wireless communication terminal, and an inter-BSS PPDU may indicate a PPDU transmitted 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 communicating wirelessly includes: a transceiver; and a processor. The processor is configured to receive, through the transceiver, a PLCP protocol data unit (PPDU) and access a channel based on whether the PPDU is an inter-BSS PPDU or an intra-BSS PPDU, where an intra-BSS PPDU indicates a PPDU transmitted from the same BSS as the BSS including the wireless communication terminal, and an inter-BSS PPDU indicates a PPDU transmitted 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 can be recognized as an inter-BSS PPDU.

[0019] When the PPDU is not recognized as an inter-BSS PPDU or an intra-BSS PPDU, the processor can set the basic Network Allocation Vector (NAV) based on the PPDU instead of the intra-BSS NAV, can set the intra-BSS NAV based on a PPDU sent from the same BSS as the wireless communication terminal, and can 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 recognize 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 can set the intra-BSS NAV based on a PPDU sent from the same BSS as the BSS of the wireless communication terminal.

[0021] When receiving signaling information indicating that the operation based on the BSS color is not allowed, the processor can 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 identifies 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 can be set not 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 recognize whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color, the processor can be configured to enter the power saving mode not based on the BSS color.

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

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

[0027] Based on information related to SR operations included in a PPDU indicating whether SR operations are restrictively allowed or SR operations are deferred while a PPDU is being transmitted, a processor may be configured to determine whether the PPDU includes a trigger frame.

[0028] 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 Physical Layer Convergence Procedure Protocol Data Unit (PPDU) via 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 treat the PPDU as a within-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] Advantageous Effects

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

[0034] Figure 1 Shows a wireless LAN system according to an embodiment of the present invention.

[0035] Figure 2 Shows a wireless LAN system according to another embodiment of the present invention.

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

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

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

[0039] Figure 6 Shows a wireless communication terminal entering a power saving mode based on the BSS color according to an embodiment of the present invention.

[0040] Figure 7 Shows a wireless communication terminal entering a power saving mode during an inter-BSS color conflict according to an embodiment of the present invention.

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

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

[0043] Figure 10 Shows the operation of a wireless communication terminal according to an embodiment of the present invention to determine whether to reset the NAV based on a CF-End (CF-End) frame when a BSS color conflict occurs.

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

[0045] Figure 12 Shows the operation of a wireless communication terminal according to an embodiment of the present invention to identify a BSS color conflict.

[0046] Figure 13 Shows the MAC frame format of a Clear to Send (CTS) frame and an ACK frame according to an embodiment of the present invention.

[0047] Figure 14 Shows the operation of a wireless communication terminal according to an embodiment of the present invention to set the NAV based on an RTS frame and a CTS frame.

[0048] Figure 15 Shows the format of an 802.11a PPDU according to an embodiment of the present invention.

[0049] Figure 16 Shows the format of the service field of a PPDU according to an embodiment of the present invention.

[0050] Figure 17 Shows the operation of a wireless communication terminal according to an embodiment of the present invention to set the NAV according to Figures 15 to 16 an embodiment of

[0051] Figure 18 Shows the method for a wireless communication terminal according to an embodiment of the present invention to set the partial AID and group ID fields of a VHT-SIG-A.

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

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

[0054] Figure 21 Discloses a method for a wireless communication terminal according to an embodiment of the present invention to determine whether a received PPDU is an inter-BSS PPDU or an in-BSS PPDU when the PPDU received by the wireless communication terminal satisfies both inter-BSS PPDU conditions and in-BSS PPDU conditions.

[0055] Figure 22 Illustrates a situation where a wireless communication terminal according to an embodiment of the present invention enters a power-saving state based on the MAC header of a frame received by the wireless communication terminal.

[0056] Figure 23 Illustrates a situation where a wireless communication terminal according to an embodiment of the present invention enters a power-saving state based on the MAC header of a frame received by the wireless communication terminal when the wireless communication terminal is included in a BSS corresponding to a multi-BSSID set.

[0057] Figure 24 Illustrates the format of the HE-SIG-B field according to an embodiment of the present invention.

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

[0059] Figure 26 Is a view illustrating the variants of the HT control field according to an embodiment of the present invention.

[0060] Figure 27 Illustrates the format of the A-Control subfield according to an embodiment of the present invention.

[0061] Figure 28 Illustrates the format of the A-Control subfield of the control subfield according to another embodiment of the present invention.

[0062] Figures 29 to 33 Illustrates the frame format and HE variant format of the HT control field according to another embodiment of the present invention.

[0063] Figure 34 Illustrates the format of the trigger frame according to an embodiment of the present invention.

[0064] Figure 35 Illustrates the formats of the common information field and per-user information field of the trigger frame according to an embodiment of the present invention.

[0065] Figure 36Shows the common information field and per-user information field of a trigger frame according to another embodiment of the present invention.

[0066] Figure 37 Shows the trigger-related common information field and trigger-related per-user information field of a MU-BAR type trigger frame according to an embodiment of the present invention.

[0067] Figure 38 Shows the format of the trigger-related common information field of a MU-BAR type trigger frame according to an embodiment of the present invention.

[0068] Figure 39 Shows the format of a MU-BAR type trigger frame for GCR according to an embodiment of the present invention.

[0069] Figure 40 Shows the format of a MU-BAR type trigger frame for GCR according to an embodiment of the present invention.

[0070] Figure 41 Shows the format of a BAR control field and the encoded values of BlockACKReq variants according to an embodiment of the present invention.

[0071] Figure 42 Shows the format of a BAR information field according to an embodiment of the present invention.

[0072] Figure 43 Shows a BAR information field according to another embodiment of the present invention.

[0073] Figure 44 Shows the trigger frame structure according to another embodiment of the present invention.

[0074] Figure 45 Shows the operation of a wireless communication terminal according to an embodiment of the present invention. Detailed Description of the Invention

[0075] 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 embodied in different forms and should not be construed as limited to the embodiments set forth herein. Parts irrelevant to the description are omitted in the drawings for a clear description of the present invention, and like reference numerals refer to like elements throughout.

[0076] In addition, when it is described that a thing includes (or contains or has) some elements, it should be understood that if there is no specific limitation, 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 the priority and benefits of Korean Patent Application Nos. 10-2016-0026684 (filed on Mar. 4, 2016), 10-2016-0029975 (filed on Mar. 12, 2016), 10-2016-0044465 (filed on Apr. 11, 2016), 10-2016-0057597 (filed on May 11, 2016), and 10-2016-0114821 (filed on Sep. 7, 2016) submitted to the Korean Intellectual Property Office, and the embodiments described and the items mentioned in the corresponding applications are included in the detailed description of this application.

[0078] Figure 1 FIG. is a diagram of a wireless communication system according to an embodiment of the present invention. For convenience of description, embodiments of the present invention are described by a wireless LAN system. The wireless LAN system includes one or more basic service sets (BSSs), and a BSS represents a set of devices that have successfully synchronized with each other to communicate with each other. Generally, BSSs can be classified into infrastructure BSSs and independent BSSs (IBSSs), and Figure 1 FIG. illustrates an infrastructure BSS between them.

[0079] As Figure 1 illustrated, the infrastructure BSSs (BSS1 and BSS2) include 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 the multiple access points PCP / AP-1 and PCP / AP-2.

[0080] A station (STA) is a predetermined device including a medium access control (MAC) that follows the procedures of the IEEE 802.11 standard and a physical layer interface for a wireless medium, and in a broad sense includes a non-access point (non-AP) station and an access point (AP). Additionally, in this specification, the term "terminal" may be used to refer to a concept including a wireless LAN communication device such as a non-AP STA or an 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 transmitted through a wireless network or process a frame received through a wireless network, and furthermore, execute various processes for controlling the station. In addition, the transceiver is functionally connected to the processor and transmits and receives frames through the wireless network for the station.

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

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

[0083] Figure 2 FIG. illustrates a stand-alone BSS as a wireless communication system according to another embodiment of the present invention. For convenience of description, another embodiment of the present invention is described by a wireless LAN system. In Figure 2 the embodiment of, a repeated description of parts identical or corresponding to Figure 1 the embodiment of will be omitted.

[0084] Since Figure 2 the BSS3 illustrated in is a stand-alone BSS and does not include an AP, all stations STA6 and STA7 are not connected to an AP. The stand-alone BSS is not permitted to access the distribution system and forms a complete network. In the stand-alone BSS, the corresponding stations STA6 and STA7 can be directly connected to each other.

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

[0086] As Figure 3 illustrated in, 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 externally. According to this embodiment, the transceiver 120 may include at least one transmit and receive module using different frequency bands. For example, the transceiver 120 may include transmit and receive modules having different frequency bands such as 2.4 GHz, 5 GHz, and 60 GHz. According to an embodiment, the station 100 may include a transmit and receive module using a frequency band of 6 GHz or higher and a transmit and receive module using a frequency band of 6 GHz or lower. The corresponding transmit and receive modules may perform wireless communication with an AP or an external station according to the wireless LAN standard of the frequency band supported by the corresponding transmit and receive module. The transceiver 120 may operate only one transmit and receive module at a time or operate multiple transmit and receive modules simultaneously according to the performance and requirements of the station 100. When the station 100 includes multiple transmit and receive modules, each transmit and receive module may be implemented by independent elements or multiple modules may 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 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 output based on the 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 the content executed by the processor 110 or the user interface based on the control command of the processor 110 and the like. In addition, the memory 160 stores control programs used in the station 100 and various resultant 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 can execute various commands or programs and process data in the station 100. Additionally, the processor 110 can control 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 can execute a program for accessing the AP stored in the memory 160 and receive a communication configuration message sent by the AP. Additionally, the processor 110 can read information about the priority conditions of the station 100 included in the communication configuration message and request access to the AP based on the information about the priority conditions of the station 100. The processor 110 of the present invention can represent the main control unit of the station 100 and, according to this embodiment, the processor 110 can represent a control unit for individually controlling a certain component (e.g., the transceiver 120, etc.) of the station 100. The processor 110 can be a modulator and / or demodulator that modulates wireless signals sent to the transceiver 120 and demodulates wireless signals 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. Detailed embodiments thereof will be described below.

[0091] Figure 3 The station 100 illustrated in FIG. is a block diagram according to an embodiment of the present invention, where individual blocks are illustrated as logically distinct elements of the device. Thus, 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. Additionally, 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 provided in the station 100.

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

[0093] As Figure 4 illustrated, the AP 200 according to an embodiment of the present invention can include a processor 210, a transceiver 220, and a memory 260. In Figure 4 Among the components of the AP 200, a repeated description of parts that are the same as or corresponding to the components of Figure 2 the station 100 will be omitted.

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

[0095] Next, the memory 260 stores control programs used in the AP 200 and various result-obtained data. The control program may include an access program for managing access of a station. In addition, the processor 210 may control corresponding units of the AP 200 and control data transmission / reception between these units. According to an embodiment of the present invention, the processor 210 may execute a program for accessing a 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 access priority conditions of the corresponding station. In addition, the processor 210 performs access configuration according to an access request of a station. The processor 210 may be a modulator and / or demodulator that modulates a wireless signal transmitted to the transceiver 220 and demodulates a wireless signal received from the transceiver 220. The processor 210 controls various operations such as radio signal transmission / reception of the AP 200 according to the first embodiment of the present invention. Detailed embodiments thereof will be described below.

[0096] Figure 5 is a diagram schematically illustrating a process of a STA setting a link with an AP.

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

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

[0099] Meanwhile, an 802.1X-based authentication step (S111) and an IP address acquisition step via DHCP (S113) can be additionally performed. In Figure 5 this case, the authentication server 300 is a server that processes 802.1X-based authentication for the STA 100 and can exist physically associated with the AP 200 or as a separate server.

[0100] In a specific embodiment, the AP 200 can be a wireless communication terminal that allocates communication medium resources and performs scheduling in an independent network (such as an ad hoc network) not connected to an external distribution service. In addition, the AP 200 can 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 provision of wireless communication, wireless communication terminals increasingly communicate in dense environments. In particular, the number of cases where wireless communication terminals communicate in an environment where multiple BSSs overlap is increasing. When multiple BSSs overlap, the communication efficiency of wireless communication terminals may degrade due to interference from other wireless communication terminals. In particular, when using a frequency band through a contention process, wireless communication terminals may not even be able to guarantee a transmission opportunity due to interference from other wireless communication terminals. To solve this problem, wireless communication terminals can perform a spatial reuse (SR) operation. Specifically, the SR operation can include an operation of accessing a channel according to whether the received frame is a MAC frame sent from the BSS including the wireless communication terminal or a MAC frame sent from another BSS. For the convenience of description, when a frame is used without any description in the following description, it is assumed to refer to a MAC frame.

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

[0103] Specifically, the wireless communication terminal may apply a CCA threshold according to whether the PPDU received while transmitting the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU. In a specific embodiment, the CCA threshold may be applied according to whether the PPDU received while transmitting the payload of the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU. Additionally, the wireless communication terminal may receive a first PPDU and receive a second PPDU while applying the CCA threshold according to whether the first PPDU is an inter-BSS PPDU or an intra-BSS PPDU. Specifically, the wireless communication terminal may apply a CCA threshold according to whether the PPDU received while transmitting the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU. Specifically, when the wireless communication terminal receives an inter-BSS PPDU and applies the CCA threshold corresponding to the inter-BSS PPDU, it may receive an intra-BSS PPDU. At this time, the wireless communication terminal may apply the CCA threshold corresponding to the intra-BSS PPDU instead of the CCA threshold corresponding to the inter-BSS PPDU. However, when the wireless communication terminal receives an intra-BSS PPDU and applies the CCA threshold corresponding to the intra-BSS PPDU, the wireless communication terminal may receive an inter-BSS PPDU before the transmission of the intra-BSS PPDU is 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 operations, 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 a power saving mode according to whether the 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.

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

[0106] Figure 6 Illustrated is a wireless communication terminal entering a power saving mode based on BSS coloring according to an embodiment of the present invention.

[0107] When the receiver of the PPDU transmitted within the BSS does not include a non-AP wireless communication terminal, the non-AP wireless communication terminal can enter the power saving mode. Specifically, the non-AP wireless communication terminal can enter the 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 the non-AP wireless communication terminal, the non-AP wireless communication terminal can enter the 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 the power saving mode. In addition, when the PPDU received by the non-AP wireless communication terminal is a trigger-based 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 according to the UL_FLAG value of the 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 according to the STA_ID_LIST of the RXVECTOR. In addition, the non-AP wireless communication terminal can leave the power saving mode when the corresponding PPDU is not transmitted. At this time, the RXVECTOR is a parameter set indicating the information of the PPDU received by the module of the MAC layer from the module of the physical layer when the wireless communication terminal receives the PPDU.

[0108] In addition, a 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. Furthermore, the non-AP wireless communication terminal may operate a Network Allocation Vector (NAV) timer in the power saving mode and access the wireless medium when the NAV timer expires. Additionally, 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 where the power saving mode option is activated may be the case where the value of dot11IntraPPDUPowerSaveOptionActivated is True. Additionally, 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 state.

[0109] In Figure 6 In an embodiment, 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 may enter the power saving mode. Specifically, when at least one of the above conditions is met, the station STA may enter the power saving mode. Furthermore, when the transmission of the corresponding PPDU is terminated, the station STA leaves the power saving mode.

[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 referred to as an inter-BSS color conflict or a BSS color conflict.

[0111] Figure 7 It shows that a wireless communication terminal according to an embodiment of the present invention enters the power saving mode during an 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 the power saving mode. Therefore, the non-AP wireless communication terminal may not receive a PPDU sent by an AP associated with the non-AP wireless communication terminal as in the Figure 7 embodiment. At this time, 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 a wireless communication terminal cannot identify the BSS to which a corresponding PPDU is transmitted based on the BSS color signaled by the PPDU, the wireless communication terminal may not perform an operation based on the BSS color. Specifically, when the wireless communication terminal cannot identify the BSS based on the BSS color signaled by the PPDU, the wireless communication terminal may not perform an operation based on the BSS color that is the same as the BSS color between the wireless communication terminal and the BSS. For example, when the wireless communication terminal cannot identify the BSS based on the BSS color signaled by the PPDU, even when the wireless communication terminal receives a PPDU indicating the BSS color that is the same as the BSS color between the wireless communication terminal and the BSS, the wireless communication terminal may not regard the PPDU as an inter-BSS PPDU.

[0114] When a non-AP wireless communication terminal cannot identify whether a 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 enter a power saving mode without being 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 enter a power saving mode without being 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 enter a power saving mode without being 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 operate in a power saving mode within the PPDU without being based on the BSS color value. Additionally, 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 de-associated. In yet another specific embodiment, from the time when the non-AP wireless communication terminal detects a BSS color conflict, the non-AP wireless communication terminal may stop entering the power saving mode.

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

[0116] A wireless communication terminal may maintain two NAVs, namely, an in-BSS NVA set based on a PPDU recognized as an in-BSS PPDU and a basic NAV set based on a PPDU recognized as an inter-BSS PPDU. At this time, the wireless communication terminal may set the basic NAV based on a PPDU that may not be recognized as an inter-BSS PPDU or an in-BSS PPDU. Specifically, the wireless communication terminal may maintain two NAVs through the following operations.

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

[0118] The wireless communication terminal receives a signaling field of a PPDU including BSS identification information from the PPDU, and the wireless communication terminal may set two NAVs based on the BSS identification information signaled by the signaling field of the PPDU. At this time, the PPDU may be a HE-PPDU, and the signaling field of the PPDU may be a HE-SIG-A field. In addition, the BSS identification information may be a BSS color. Additionally, the wireless communication terminal may 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 the PPDU and the BSS identification information signaled by the signaling field of the PPDU is recognized as in-BSS, the wireless communication terminal may set the in-BSS NAV based on the signaling field of the PPDU. Additionally, when the wireless communication terminal receives a signaling field of a PPDU including BSS identification information from the PPDU, and the BSS identification information signaled by the signaling field of the PPDU is recognized as inter-BSS, the wireless communication terminal may set the basic NAV based on the signaling field of the PPDU.

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

[0120] When the value of the duration field of a frame recognized by the wireless communication terminal as a frame within the BSS is greater than the value of the current NAV within the BSS, the wireless communication terminal may set the NAV within the BSS 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 a frame within the BSS or an inter-BSS frame is greater than the value of the current basic NAV, the wireless communication terminal may 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 a PPDU recognized by the wireless communication terminal as a PPDU within the BSS is greater than the value of the current NAV within the BSS, the wireless communication terminal may set the NAV within the BSS based on the value of the TXOP duration field of the signaling field of the PPDU recognized as a PPDU within the BSS. In addition, when the value of the TXOP duration field of the signaling field of a PPDU recognized by the wireless communication terminal as an inter-BSS PPDU is greater than the value of the current basic NAV, the wireless communication terminal may set the basic NAV based on the value of the TXOP duration field of the signaling field of the corresponding PPDU.

[0122] When a wireless communication terminal receives a 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 it sends the CF-End frame. Specifically, when the BSS of the PPDU that sets the currently set NAV 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 of the PPDU that sets the currently set NAV 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 a CF-End frame from a BSS that does not correspond to the BSS indicated by a multi-BSSID set between BSSs or a BSSID within a BSS, and sets the most recent NAV by a PPDU sent from any one of the BSSs indicated by the multi-BSSID set within the 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 the multi-BSSID set within the BSS or the BSSID within the BSS, and sets the most recent NAV by a PPDU that does not correspond to the BSS indicated by a set of multiple BSSIDs including BSSIDs between BSSs or within BSSs, the wireless communication terminal may not reset the NAV.

[0123] The trigger frame sent by the AP may trigger the 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 the 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 the NAV. Additionally, 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 the NAV. Additionally, when the NAV is set by a frame sent by another wireless communication terminal within the BSS, the wireless communication terminal may start UL MU transmission based on the trigger frame without considering the NAV. Additionally, when the field in the trigger frame indicating whether channel sensing is required indicates that channel sensing is not required, the wireless communication terminal may start UL MU transmission based on the trigger frame without considering the NAV. Specifically, the field indicating whether channel sensing is required in the trigger frame may be the CS required field.

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

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

[0126] In 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 an inter-BSS frame sent by the second station STA2 included in the first BSS BSS1. At this time, the station STA recognizes 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 within the BSS, the wireless communication terminal can start the UL MU transmission based on the trigger frame without considering the NAV. Therefore, the first station STA1 can start the uplink transmission based on the trigger frame sent by the AP of the first BSS BSS1. At this time, since a frame is being sent from the third station STA3 to the second station STA2, interference occurs in the second BSS BSS2 due to the trigger-based UL frame based on the trigger frame sent by the first station STA1. Therefore, a method for operating a wireless communication terminal that can minimize the impact of BSS color conflicts when a BSS color conflict occurs is needed. For example, in Figure 8 In an embodiment, when the first station STA1 sets the basic NAV instead of the intra-BSS NAV based on the frame sent by the second station STA2, interference occurring in the second BSS BSS2 due to the transmission of the first station STA1 can be prevented. This will be described with reference to Figure 9 this.

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

[0128] When a wireless communication terminal cannot identify whether a 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 be uncertain 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 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 to say, 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 may 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 may set the basic NAV based on the TXOP duration field of the corresponding PPDU. At this time, the TXOP duration field of the PPDU may be the TXOP duration field of the HE-SIG-A field.

[0129] In addition, when a wireless communication terminal cannot identify whether a 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 a 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 may set the intra-BSS NAV or the basic NAV based on other parameters or other conditions of the RXVECTOR. The case where a 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 cases: The MAC frame included in the PPDU cannot be decoded. In addition, the case where a 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 cases: The PPDU is not identified as an intra-BSS PPDU or an inter-BSS PPDU based on at least one of the format of the PPDU and the usage. Through these embodiments, the wireless communication terminal may prevent interference to the transmission in the OBSS that may occur due to BSS color conflicts.

[0130] In Figure 9 the embodiment, the BSS color of the first BSS BSS1 including the first station STA1 is the same as the BSS color of the second BSS BSS2 including the second station STA2 and the third station STA3. At this time, the first station STA1 may determine that 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, since 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 the basic NAV. Therefore, since 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 a wireless communication terminal maintains two NAVs, the wireless communication terminal may reset the NAV according to the BSS that sends the CF-End frame and the BSS that sends the frame for setting 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. This will be described with reference to Figure 10 and Figure 11 this.

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

[0133] In Figure 10 the embodiment of, 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 (intra-BSS frame) from the second station STA2. The first station STA1 sets the intra-BSS NAV based on the frame transmitted from the second station STA2. In addition, the first station STA1 receives a frame (inter-BSS frame) from the third station STA3. However, since 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 currently set NAV value, 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 intra-BSS NAV based on the CF-End frame received from the second station STA2. Thereafter, the first station STA1 can transmit a frame even when attempting to transmit to the third station STA3. Therefore, the transmission of the first station STA1 may conflict with the transmission of the third station STA3.

[0134] It can be solved by referring to Figure 10 the embodiment described in Figure 10 However, even when following the embodiment described in the reference Figure 9 there may be a problem with the operation of the wireless communication terminal that receives the CF-End frame. This will be described with reference to Figure 11 this.

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

[0136] As described above, the wireless communication terminal can determine whether to reset the NAV according to the BSS that transmits the CF-End frame. Specifically, when the BSS that transmits the PPDU for setting the currently set NAV is the same as the BSS that transmits the CF-End frame, the wireless communication terminal can reset the currently set NAV. Additionally, when the BSS that transmits the PPDU for setting the currently set NAV is different from the BSS that transmits the CF-End frame, the wireless communication terminal can refrain from resetting the NAV.

[0137] In addition, when setting the NAV by means of a PPDU that 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 can refrain from resetting the NAV based on the CF-End frame transmitted from within the BSS. In addition, when setting the NAV by means of a PPDU that 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 can refrain from resetting the NAV based on the CF-End frame transmitted 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 transmissions in the OBSS caused by BSS color conflicts. In addition, 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.

[0138] As described above, the situation 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 can include the situation where the wireless communication terminal identifies a BSS color conflict. This will be described in detail Figure 12 with reference to

[0139] Figure 12 FIG. shows the operation of the wireless communication terminal identifying a BSS color conflict according to an embodiment of the present invention.

[0140] A wireless communication terminal may determine a BSS color conflict based on a MAC header. Specifically, the wireless communication terminal may determine the BSS color conflict based on an 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 the BSSID including the BSSID within the BSS, the wireless communication terminal may determine the corresponding PPDU as a PPDU within the BSS. 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 a signaling field of the PPDU and a PPDU format, and may not decode the MAC header. Specifically, when a 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 an SU PPDU through L-SIG signaling. In addition, the non-AP wireless communication terminal may determine that the corresponding PPDU is an extended range SU PPDU based on the 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 for uplink transmission and the destination of the PPDU is not the non-AP wireless communication terminal. Additionally, 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. Additionally, 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 cases: The wireless communication terminal (STAID) field of the signaling field of the PPDU does not include the following broadcast address / multicast address, which includes the 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 may still 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 may 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 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. Additionally, 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: As described above, 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.

[0144] When the wireless communication terminal cannot identify whether the PPDU is a BSS-internal PPDU or a BSS-inter PPDU based on the BSS color value indicated by the signaling field of the PPDU, other wireless communication terminals may not be able to identify whether the PPDU sent from the corresponding BSS is a BSS-internal PPDU or a BSS-inter PPDU, resulting in possible failures. Additionally, another wireless communication terminal cannot identify whether the PPDU sent by the wireless communication terminal is a BSS-internal PPDU or a BSS-inter PPDU, such that the PPDU sent by the wireless communication terminal may cause failures in other wireless communication terminals. To prevent such failure problems, the wireless communication terminal may operate as in the following embodiments.

[0145] Specifically, a wireless communication terminal can send a PPDU by including signaling information indicating that operation based on BSS color is not allowed in the signaling field of the PPDU. At this time, a wireless communication terminal that receives a PPDU including signaling information indicating that operation based on BSS color is not allowed may not perform an operation based on BSS color. In a specific embodiment, a wireless communication terminal can 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 a wireless communication terminal receives signaling information indicating that operation based on BSS color is not allowed, the wireless communication terminal may not perform an 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 SR operation based on the BSS color value. In addition, a wireless communication terminal can send a PPDU by including signaling information indicating that operation based on BSS color is not allowed in the signaling field of the PPDU through a traditional PPDU. Specifically, a wireless communication terminal can even send signaling information indicating that operation based on BSS color is not allowed by using a BW signaling method of a MAC address or using reserved bits of a MAC header.

[0147] In addition, when a wireless communication terminal receives a PPDU indicating a predetermined value in the BSS color, the wireless communication terminal may not perform an operation based on the BSS color. Specifically, when a wireless communication terminal receives a PPDU indicating a predetermined value as the BSS color, the wireless communication terminal may not perform an SR operation on the corresponding PPDU. In a specific embodiment, when a wireless communication terminal receives a PPDU indicating a predetermined value as the BSS color, the wireless communication terminal may regard the PPDU as a PPDU within the BSS. Therefore, when a wireless communication terminal receives a PPDU indicating a predetermined value as the 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 operation based on BSS color is not allowed can access the channel without using an SR operation. Specifically, a wireless communication terminal that receives signaling information indicating that operation based on BSS color is not allowed can access the channel without using the BSS color value.

[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 malfunction in a wireless communication terminal that operates based on the BSS color. A method for preventing this is needed.

[0150] An AP that operates a BSS may select a BSS color corresponding to the BSS. A non-AP wireless communication terminal may obtain a BSS color assigned to the non-AP wireless communication terminal from a BSS color field included in a 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 a 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 re-association request frame, a re-association response frame, a probe request frame, and a probe response frame.

[0151] When the non-AP wireless communication terminal fails to receive information signaling a BSS color, the non-AP wireless communication terminal may use a predetermined value as the 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 signaling a BSS color, the non-AP wireless communication terminal may set the BSS color value signaled by the PPDU transmitted by the non-AP wireless communication terminal to the predetermined value. In addition, when the non-AP wireless communication terminal fails to receive information signaling a BSS color, the non-AP wireless communication terminal may set the BSS color value signaled by a frame transmitted by the non-AP wireless communication terminal to the predetermined value. When the non-AP wireless communication terminal does not receive information signaling a BSS color, this is because there is no BSS color. Specifically, when the non-AP wireless communication terminal does not receive information 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 signaling a BSS color may include a case where the non-AP wireless communication terminal may 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 signaling a BSS color may include the following case: after receiving signaling information from the AP indicating that 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 a non-AP wireless communication terminal fails to receive a HE operation element, the non-AP wireless communication terminal may set the BSS color value included in the PPDU transmitted by the non-AP wireless communication terminal to a predetermined value. For example, the non-AP wireless communication terminal may use the predetermined value as the BSS color value when transmitting 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 the predetermined value when transmitting a probe request frame. When transmitting a probe request frame, the non-AP wireless communication terminal may set the value of the BSS color field in the HE-SIG-A field of the PPDU including the probe request frame to the predetermined value.

[0153] In another specific embodiment, when transmitting 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 very likely that the wireless communication terminal does not know the BSS color between BSSs. In addition, this is because the wireless communication terminal between BSSs 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 the BSS color, the wireless communication terminal may not perform operations based on the BSS color. Specifically, when the wireless communication terminal receives a PPDU indicating a predetermined value as 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 as the BSS color, the wireless communication terminal may regard the PPDU as a within-BSS PPDU. Therefore, when the wireless communication terminal receives a PPDU indicating a predetermined value as the BSS color, the wireless communication terminal may not discard the corresponding PPDU.

[0155] The non-traditional PPDU includes a signaling field indicating the BSS color, such as the HE-SIG-A field, and the wireless communication terminal may perform various SR operations described above based on the signaling field indicating the BSS color. However, the traditional PPDU does not include a signaling field indicating the BSS color. Therefore, the wireless communication terminal receiving the traditional PPDU must perform an SR operation based on the MAC frame included in the PPDU. However, there is a MAC frame that includes only the receiver address RA and does not include the transmitter address TA. When the operation based on the BSS color may not be performed because a MAC frame including only the receiver address is transmitted via a traditional PPDU or a BSS color conflict occurs, the SR operation for the MAC frame including only the receiver address may be a problem. Embodiments of the wireless communication terminal related thereto will be described with reference to Figure 13 and Figure 14 descriptions of embodiments of the wireless communication terminal related thereto.

[0156] Figure 13Shows the MAC frame format that allows the transmission of Clear to Send (CTS) frames and ACK frames according to an embodiment of the present invention. Figure 14 Shows the operation of a wireless communication terminal setting the Network Allocation Vector (NAV) based on Request to Send (RTS) frames and CTS frames according to an embodiment of the present invention.

[0157] The MAC frames of CTS frames and ACK frames may include a Frame Control field that includes information about frame control. In addition, the MAC frames of CTS frames and ACK frames may include a Duration field for NAV setting. In addition, the MAC frames of CTS frames and ACK frames may include a Receiver Address (RA) field indicating the receiver address. In addition, the MAC frames of CTS frames and ACK frames may include a Frame Check Sequence (FCS) field indicating whether the MAC frame includes an error.

[0158] The RA field of the CTS frame can be set based on the Transmitter Address (TA) field of the RTS frame. Specifically, the value of the RA field of the CTS frame for the TA field of the RTS frame can be a value with the Individual / Group bit set to zero. Additionally, when the CTS frame is the first frame of a 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, management frame, BlockACKReq frame, BlockACK frame, or PS-Poll frame sent to a wireless communication terminal. Specifically, the RA field of the ACK frame can set the value of the Address 2 field of a data frame, management frame, BlockACKReq frame, BlockACK frame, or PS-Poll frame sent to a wireless communication terminal to the non-bandwidth signaling TA value. Additionally, the RA field of the ACK frame can be set to the MAC address of the receiver.

[0160] When a wireless communication terminal may not be able to determine whether a frame is an in - BSS frame or an inter - BSS frame based on the address field of a CTS frame or an ACK frame, the wireless communication terminal can set a basic NAV based on the corresponding frame. Specifically, when the wireless communication terminal may not be able to determine whether a frame is an in - BSS frame or an inter - BSS frame based on a PPDU including a CTS frame or an ACK frame and may not be able to determine whether a frame is an in - BSS frame or an inter - BSS frame based on the address field of the CTS frame or the ACK frame, the wireless communication terminal can set a basic NAV based on the frame. Additionally, the situation where the wireless communication terminal may not be able to determine whether a frame is an in - BSS frame or an inter - BSS frame based on the address field of the CTS frame or the ACK frame can be the following situation: 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 can receive a downlink (DL) CTS frame. At this time, the address field of the corresponding CTS frame can include the address of the non - AP wireless communication terminal and can not include the address of the wireless communication terminal as an AP or the BSSID. Therefore, the wireless communication terminal that receives the corresponding CTS frame may not be able to determine whether the corresponding CTS frame is an inter - BSS frame or an in - BSS frame based on the address field of the corresponding CTS frame. Additionally, when the wireless communication terminal may not be able to determine whether a frame is an in - BSS frame or an inter - BSS frame based on a PPDU including a CTS frame or an ACK frame, the corresponding PPDU can be a legacy PPDU. This is because a legacy PPDU may not include information indicating the BSS color. Furthermore, the situation where the wireless communication terminal may not be able to determine whether a frame is an in - BSS frame or an inter - BSS frame based on a PPDU including a CTS frame or an ACK frame can be the following situation: the wireless communication terminal may not be able to determine whether a frame is an in - 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 a wireless communication terminal receives a frame, the wireless communication terminal can set a 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 a basic NAV based on the frame.

[0162] In addition, when a wireless communication terminal maintains a NAV, instead of setting a basic NAV based on a corresponding frame as in the above embodiments, the wireless communication terminal may consider that the NAV set through the corresponding frame is not set through an in-BSS frame. Specifically, when the wireless communication terminal may not be able to determine whether a frame is an in-BSS frame or an inter-BSS frame based on the 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 through an in-BSS 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 through an in-BSS frame, regardless of the value of the address field of the frame.

[0163] In Figure 14 the embodiment, 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 an in-BSS NAV based on the RTS frame. Since the address field of the CTS frame sent by the second station STA2 only includes 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 an in-BSS frame. Therefore, the third station STA3 sets a basic NAV based on the CTS frame sent by the second station STA2 as in some of the above embodiments.

[0164] At this time, when the third station STA3 receives a CF-End frame sent from the first station STA1 or the second station STA2, the third station STA3 recognizes the received CF-End frame as an in-BSS frame. Therefore, even if the third station STA3 receives a CF-End frame sent from the first station STA1 or the second station STA2, the third station STA3 only resets the in-NAV based on the received CF-End frame, and the basic NAV is maintained. When the third station STA3 does not receive an RTS frame but receives a CF-End frame from an inter-BSS in a state of receiving only a CTS frame, the third station STA3 may initiate a transmission during the transmission process of the first station STA1 and the second station STA2, thus 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 signaling a BSS color. However, when sending a PPDU signaling a BSS color, a traditional wireless communication terminal may not decode the PPDU. In addition, the wireless communication terminal may infer the BSS of a CTS frame and an ACK frame based on a frame sent before the CTS frame or the ACK frame. For this reason, there is a problem that the wireless communication terminal may need to receive a previously sent frame and store information about the received frame. Therefore, the wireless communication terminal may send information identifying the BSS through a traditional PPDU. Reference will be made toFigures 15 to 17 Describe this.

[0166] Figure 15 Show the format of an 802.11a PPDU according to an embodiment of the present invention.

[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 required. Specifically, the format of the 802.11a PPDU may be the same as Figure 15 the format of

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

[0169] In addition, the information for identifying the BSS may be any one of the BSS color, the 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 information for identifying the BSS through a field other than the service field. Specifically, the wireless communication terminal may send information for identifying the BSS through the signal field.

[0171] In addition, the wireless communication terminal may send information for identifying the BSS by combining multiple reserved fields.

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

[0173] Figure 16 Show the format of the service field of the PPDU according to an embodiment of the present invention.

[0174] As described in reference Figure 15 , a wireless communication terminal may use the reserved bits of the service field to transmit information for identifying a BSS. Specifically, the wireless communication terminal may use the eighth bit B7 to the thirteenth bit B12 of the service field to transmit information for identifying a BSS. Since reserved bits are used in the embodiments described in reference Figures 15 to 16 , a conventional wireless communication terminal that does not support the embodiments of the present invention cannot decode the information for identifying a BSS, but can successfully receive a PPDU according to the embodiments of the present invention.

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

[0176] Figure 17 Illustrates the operation of setting NAV by a wireless communication terminal according to an embodiment of the present invention according to Figures 15 to 16 the embodiments.

[0177] In Figure 17 the embodiments, the first station STA1 to the third station STA3 are all included in the same BSS. The first station STA1 transmits an RTS frame and the second station STA2 transmits a CTS frame in response to the RTS frame. The third station STA3 sets the NAV within the BSS based on the RTS frame. The address field of the CTS frame transmitted by the second station STA2 only includes the address of the first station STA1, but like in the embodiments described in reference Figures 15 to 16 , the reserved field of the PPDU including the CTS frame transmitted by the second station STA2 includes information for identifying a BSS. At this time, the reserved field may be the reserved bits in the service field. The third station STA3 obtains the information for identifying a BSS based on the reserved field. The third station STA3 may set the NAV within the BSS based on the information for identifying a BSS. In Figure 17 the embodiments, the third station STA3 does not set the value of the NAV within the BSS because the value of the NAV within the BSS that has already 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 NAV within the BSS 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 NAV within the BSS. In addition, when the third station STA3 receives a CF-End frame from outside the BSS, the third station STA3 may not reset the NAV within the BSS.

[0179] Figure 18 A method of setting the partial AID and group ID fields of the 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. Additionally, the partial AID field of the PPDU sent to a 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. Further, when the PPDU is sent to a mesh station, the value of the partial AID field may be a value corresponding to the last 9 bits of the receiver 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 multi-user (MU). Specifically, when the data in the data field is for 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 the AP, the value of the group ID field may be zero. Additionally, when the PPDU is sent to a non-AP wireless communication terminal, the value of the group ID field may be 63. Further, 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 send information identifying the BSS through the partial AID field and the group ID field of the VHT-SIG-A. Specifically, the wireless communication terminal acting 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 the exclusive OR operation of bit operations, mod X represents the remainder value when divided by X, and dec(A[b:c]) represents the number of binary digits from the (b + 1)-th bit to the (c + 1)-th bit of A in decimal notation.

[0185] At this time, the wireless communication terminal serving as the 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 transmits 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 for 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] Figure 19 A method for 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 shown.

[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 the BSSID of the BSS including 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] A wireless communication terminal may identify whether a 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 field of the PPDU. Specifically, the wireless communication terminal may identify whether the received PPDU is an inter-BSS PPDU based on other parameter values of the RXVECTOR. Specifically, when a BSS color conflict occurs, the wireless communication terminal may 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 may 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 a 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 acting as an AP is a downlink frame, the wireless communication terminal may identify the frame as an inter-BSS frame. For example, in Figure 19 In the embodiment, 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 may identify the received PPDU as an inter-BSS PPDU. This is because, as described in reference Figure 18 , the group ID field of the PPDU sent to a non-AP wireless communication terminal is set to 63. At this time, only when the DLS protocol or TDLS protocol is not used, the wireless communication terminal acting as an AP may identify the received PPDU as an inter-BSS PPDU. As described above, this is because even when a DLS wireless communication terminal or TDLS wireless communication terminal sends a PPDU to a DLS wireless communication terminal or TDLS wireless communication terminal through a direct path, the value of the group ID field is also set to 63.

[0192] In addition, the wireless communication terminal acting as an AP may identify whether the VHT PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on a partial AID field of the VHT PPDU. Specifically, the wireless communication terminal acting as an AP may 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 may identify the corresponding PPDU as an inter-BSS PPDU.

[0193] In addition, when a wireless communication terminal acting as an AP receives a VHT MU PPDU, the wireless communication terminal may identify the PPDU as an inter-BSS PPDU. This is because a VHT MU PPDU can only be used for downlink transmission. Specifically, a wireless communication terminal acting as an AP can determine whether a 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, a wireless communication terminal acting as an AP may identify the corresponding PPDU as an MU PPDU.

[0194] In addition, when a wireless communication terminal acting 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 acting as an AP may identify the corresponding PPDU as an inter-BSS PPDU. At this time, the value of the UL / DL field may be zero. At this time, a wireless communication terminal acting as an AP may identify the received PPDU as an inter-BSS PPDU only when the DLS protocol or the TDLS protocol is not used.

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

[0196] When a wireless communication terminal acting as an AP receives a trigger-based PPDU from an untriggered wireless communication terminal, the wireless communication terminal acting as an AP may identify the corresponding PPDU as an inter-BSS PPDU. Specifically, when a wireless communication terminal acting as an AP receives a trigger-based PPDU without transmitting a trigger frame, the wireless communication terminal acting as an AP may identify the PPDU as an inter-BSS PPDU.

[0197] Figure 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 acting as an AP receives a PPDU for downlink transmission, the wireless communication terminal acting as an AP can identify the PPDU as an inter-BSS PPDU. This is because the destination of the PPDU of the wireless communication terminal acting as an AP within the BSS is a PPDU for uplink transmission. In addition, the AP acting 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 can indicate that the PPDU includes a trigger frame. Additionally, the trigger frame is only used for downlink transmission. Therefore, the wireless communication terminal acting as an AP can determine whether the corresponding PPDU is a PPDU for downlink transmission based on whether the PPDU includes a trigger frame. Thus, 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 can be the SR field of the signaling field of the PPDU. Specifically, the signaling field of the PPDU can indicate whether SR operation is allowed while the corresponding PPDU is being transmitted, and can indicate the allowed conditions. At this time, the signaling field can be the HE-SIG-A field. Specifically, the SR field can indicate SR_Delay, and SR_Delay 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, then the SR field indicates SR_Delay.

[0200] In addition, the SR field can indicate SR_Restricted, which indicates that the SR operation is allowed restrictively. 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 can be limited to the PPDU including the trigger frame. Additionally, 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 can indicate SR_Disallowed, and SR_Disallowed indicates that the SR operation is not allowed. The wireless communication terminal that transmits a PPDU including a trigger frame indicates that the PPDU includes a trigger frame through the SR field of the PPDU and can protect the transmission sequence based on the trigger frame.

[0202] Therefore, when the SR field value of the PPDU received by the wireless communication terminal acting as an AP is SR_Restricted or SR_Delay, the wireless communication terminal acting 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 SU PPDU, and the SR field signaled by the corresponding PPDU indicates SR_Restricted, the wireless communication terminal acting as an AP can identify the PPDU as an inter-BSS PPDU. Additionally, 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 acting 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. Additionally, the HE extended-range SU PPDU indicates a PPDU for transmission to a single wireless communication terminal. Additionally, the HE MU PPDU indicates a PPDU for multiple wireless communication terminals.

[0203] Additionally, 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 can 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] In Figure 20 the embodiment, the first AP, AP1, sends a trigger frame for triggering the transmissions 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 identify the corresponding PPDU as a 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 still identify the PPDU including the trigger frame sent by the first AP, AP1 as an inter-BSS PPDU.

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

[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 the MAC address, the wireless communication terminal may identify the frame as an inter-BSS frame. In this case, the situation where the wireless communication terminal cannot identify an inter-BSS frame or an intra-BSS frame based on the MAC address may include the following situation: the wireless communication terminal cannot decode the MAC header of the corresponding frame.

[0207] In addition, in the above embodiments, the inter-BSS frame condition and the intra-BSS frame condition may include all conditions for identifying whether a wireless communication terminal is an inter-BSS frame or an intra-BSS frame. For example, the wireless communication terminal may identify whether a 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 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.

[0208] In addition, the wireless communication terminal may identify whether a 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 may identify whether a 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 may identify the frame included in the corresponding PPDU as an inter-BSS frame.

[0209] If the PPDU includes a BSS color field, it is unlikely that the partial AID field includes information about the BSS color. Thus, the case where both the in-BSS frame condition and the inter-BSS color condition are satisfied can include the following cases. That is, when the wireless communication terminal performs determination based on the BSS color field or the partial AID field, the corresponding PPDU is recognized as an in-BSS PPDU, and when the wireless communication terminal performs determination based on the address field of the frame, the corresponding PPDU can be recognized as an inter-BSS 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 recognized as an in-BSS frame, and when the wireless communication terminal performs determination based on whether the PPDU including the MAC frame is in an uplink transmission format, the corresponding PPDU is recognized as an inter-BSS PPDU. Since the number of bits representing the BSS color is limited, an inter-BSS color conflict may occur as described above. Thus, when the frame received by the wireless communication terminal satisfies both the inter-BSS frame condition and the in-BSS frame condition, the wireless communication terminal can recognize whether the received frame is an inter-BSS frame or an in-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 in-BSS frame condition, the wireless communication terminal can recognize whether the received frame is an inter-BSS frame or an in-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 recognized based on the address field of the MAC header described above. Additionally, another condition can be that the PPDU including the frame is a PPDU for downlink transmission.

[0210] In Figure 21 the embodiment of, the first AP AP1 transmits 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 transmitted 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. Thus, the BSS color indicated by the HE-SIG-A field of the HE MU PPDU transmitted by the first AP AP1 satisfies the in-BSS color condition. However, when the HE MU PPDU transmitted by the first AP AP1 is a PPDU for downlink transmission including a trigger frame, and as in the above embodiment, since when the wireless communication terminal determines whether the frame received by the wireless communication terminal is an inter-BSS frame or an in-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 recognizes the HE MU PPDU transmitted by the first AP AP1 as an inter-BSS PPDU.

[0211] A wireless communication terminal can identify a received frame as an in-BSS frame according to any one condition, and then, identify the received frame as an inter-BSS frame according to the determined priority order described above. At this time, the wireless communication terminal can use an enhanced CCA level. Specifically, the wireless communication terminal can use a CCA level corresponding to the inter-BSS frame. In a specific embodiment, the CCA level corresponding to the inter-BSS frame can be referred to as the OBSS PD level.

[0212] As described above, the wireless communication terminal can enter the power saving state based on the MAC header. At this time, the specific operations of the wireless communication terminal will now be described in detail with reference to Figures 22 to 23 the following.

[0213] Figure 22 FIG. shows a situation where a wireless communication terminal according to an embodiment of the present invention enters the power saving state based on the MAC header of a frame received by the wireless communication terminal. In addition, Figure 23 FIG. shows a situation where a wireless communication terminal according to an embodiment of the present invention enters the power saving state based on the MAC header of a frame received by the wireless communication terminal when the wireless communication terminal is included in a BSS corresponding to a multi-BSSID set.

[0214] When the transmitter 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, where the multi-BSSID set includes the BSSID of the BSS that includes the wireless communication terminal, the wireless communication terminal can determine the received frame as an in-BSS frame. When the frame received by the wireless communication terminal is an in-BSS frame and the wireless communication terminal is not the receiver of the received frame, the wireless communication terminal can enter the 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] In Figure 22 the embodiment, 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 an in-BSS frame. When the received PPDU is an in-BSS frame, the second station STA2 determines whether the receiver of the received PPDU is the second station STA2. Specifically, the second station STA2 can determine whether the receiver 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 receiver of the received PPDU, the second station STA2 can enter the power saving state.

[0216] When entering the power-saving state, the wireless communication terminal can determine whether the recipient address RA of a frame indicates multiple wireless communication terminals including the corresponding wireless communication terminal. Specifically, when the received frame is an in-BSS frame, if the recipient address RA of the received frame is not the MAC address of the wireless communication terminal and the recipient 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, if the recipient address RA of the received frame does not correspond to the multicast address that the wireless communication terminal is required to receive and the recipient 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 recipient address RA of a trigger frame or the recipient address RA of a 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-STA BlockACK frame. Specifically, when the recipient of the trigger frame is multiple wireless communication terminals, the recipient address RA of the trigger frame can be the broadcast address. At this time, the number of user information fields of the trigger frame can be two or more. In addition, when the recipient of the multi-STA BlockACK frame is multiple wireless communication terminals, the recipient address RA of the multi-STA BlockACK can be the broadcast address. At this time, the number of AID fields in each STA information sub-field of the multi-STA BlockACK can be two or more. At this time, the broadcast address can indicate multiple wireless communication terminals or one wireless communication terminal.

[0218] Therefore, when the received frame is an in-BSS frame, the recipient 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 recipient 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 in-BSS frame, the recipient 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 recipient address RA of the multi-STA BlockACK frame does not correspond to the broadcast address, the wireless communication terminal can enter the power-saving state.

[0219] Specifically, when the recipient of a trigger frame or a multi-STA BlockACK frame is multiple wireless communication terminals, the recipient address RA can be a multicast address or a group address. Therefore, when the wireless communication terminal receives a trigger frame or a multi-STA BlockACK frame and the recipient address RA of the received frame is not the multicast address and group address including the wireless communication terminal, the wireless communication terminal can enter the power-saving state.

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

[0221] In Figure 23 the embodiment of, 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 in - 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. Since the transmitter address TA of the received PPDU is the second BSSID BSSID(2), the second station STA2 determines the received PPDU as an in - BSS frame. In addition, since the receiver 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 receiver of the received PPDU is the second station STA2. Specifically, the second station STA2 can determine whether the receiver 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 receiver of the received PPDU, the second station STA2 can enter the power - saving state.

[0223] In another specific embodiment, if the reference BSSID is set to the transmission address TA of the frame, it may indicate that the transmission 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 transmission address TA of the frame received by the wireless communication terminal is sent from the second BSSID, the wireless communication terminal may enter the power saving state.

[0224] As described above, the wireless communication terminal can signal various information through the signaling field of the PPDU. The format of the signaling field will be referred to Figure 24 for description.

[0225] Figure 24 Shows the format of the HE-SIG-B field according to an embodiment of the present invention.

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

[0227] Specifically, the user-specific fields include information on 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 fields may include information on the spatial configuration field, MCS, DCM, and coding. At this time, the information on coding may indicate whether LDPC is used. The common field may include a binary convolutional code (BCC) block. The user-specific fields include information on two wireless communication terminals in one BCC block. At this time, the last BCC block may include information on one wireless communication terminal. In addition, the information on an individual wireless communication terminal may be referred to as per-user content. One 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 specific format of the HE-SIG-B field may be as shown in Figure 24 (a).

[0228] When a wireless communication terminal transmits a PPDU over a frequency bandwidth of 40 MHz or higher, the wireless communication terminal may repeatedly transmit two HE-SIG-B fields each having a frequency bandwidth of 20 MHz every 40 MHz over 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 on the RUs included in the frequency bandwidth in which the corresponding HE-SIG-B field is transmitted. The wireless communication terminal that receives the PPDU may identify the configuration of the entire MU PPDU by decoding the two HE-SIG-B fields. Specifically, the wireless communication terminal may transmit the HE-SIG-B field in the form shown in Figure 24 (b).

[0229] In a specific embodiment, the wireless communication terminal can indicate the wireless communication terminal corresponding to per-user content through 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 can be an associated 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 can have one of the values from 0 to N-1 as the 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 can be an unassigned value in the multi-BSSID TIM operation. In a specific embodiment, the specific AID can be 2047.

[0230] The frame to be sent to multiple wireless communication terminals and the frame to be sent to any one wireless communication terminal can be included in one MU PPDU. At this time, the multiple RUs to which the PPDU is sent can 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 can determine whether the per-user content indicates information corresponding to the wireless communication terminal or is based on the wireless communication identifier included in the per-user content. At this time, the wireless communication terminal can 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 can be identified according to the wireless communication terminal identifier indicating a small range of wireless communication terminals. For example, the HE-SIG-B field can include N wireless communication terminal identifiers from the wireless communication terminal identifier indicating the first group to the wireless communication terminal identifier indicating the Nth group. At this time, the first group includes fewer wireless communication terminals than the second group, and the second group includes fewer wireless communication terminals than the third group. In this case, the wireless communication terminal can confirm the wireless communication terminal identifier indicating the (N-1)th group according to the wireless communication terminal identifier indicating the Nth group.

[0231] When using a multi-BSSID set, a wireless communication terminal can 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 can receive the payload of the PPDU transmitted 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 can receive the payload of the PPDU transmitted 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 terminals included in all BSSs can be included in the per-user content. At this time, the wireless communication terminal can receive the payload of the PPDU transmitted via the RU indicated by the per-user content including the wireless communication terminal identifier indicating the broadcast to the wireless communication terminals included in all BSSs. If all of 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 can 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 not using a multi-BSSID set, a wireless communication terminal can confirm the wireless communication terminal identifiers 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 can receive the payload of the PPDU transmitted 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 broadcast, multicast, and multicast of the group including the wireless communication terminal is included in the per-user content, the wireless communication terminal can receive the payload of the PPDU transmitted 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 broadcast, multicast, 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 can be included in the per-user content. At this time, the wireless communication terminal can receive the payload of the PPDU transmitted 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 of 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 convenience of explanation, the wireless communication terminal identifiers are described in three ranges, but depending on the number or inclusion relationship of the wireless communication terminals, there can 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] To enable the wireless communication terminal that receives the MAC frame to effectively control the MAC frame, the wireless communication terminal can send information about MAC frame control through the MAC frame header. At this time, a method for efficiently sending information about MAC frame control is required. This will be described with reference to Figure 25 and Figure 33 herein.

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

[0235] A MAC frame may include a frame control field indicating information regarding frame control. Additionally, 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 transmitting the frame. Further, the MAC frame may include four address fields indicating information related to addresses. Additionally, the MAC frame may include a sequence control field indicating information regarding sequence control. Further, the MAC frame may include a QoS control field indicating information regarding quality of service (QoS) control. Further, the MAC frame may include a frame body field indicating the payload of the MAC frame. Further, 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. Additionally, 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] Figure 26 is a view illustrating a variant of the HT control field according to an embodiment of the present invention.

[0237] A wireless communication terminal may transmit and modify various HT control fields. Specifically, the wireless communication terminal may transmit the HT control field in a format of an HT variant, a VHT variant, or an HE variant. Additionally, 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, the bits below the second bit B1 of the HT control field may include an HT control middle, an AC constraint, and an RDG / more PPDU subfield, as shown in Figure 26 . Additionally, 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. At this time, the bits below the second bit B1 of the HT control field may include a VHT control middle, an AC constraint, and an RDG / more PPDU subfield, as shown in Figure 26 . When the first different B0 of the HT control field is 1 and the second bit B1 is 1, the HT control field may be an HE variant. At this time, the bits below the second bit B1 of the HT control field may include an aggregation control (A-Control) subfield, as shown in Figure 26 . The A-Control subfield may include control information. The control information included in the A-Control and the format of the A-Control subfield will be described with reference to Figures 27 to 33 .

[0238] Figure 27 illustrates the format of the A-Control subfield according to an embodiment of the present invention.

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

[0240] In addition, the control sub-field may include a control ID sub-field indicating the type of information included in the control sub-field. In addition, the control sub-field may include a control information sub-field 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 sub-field may be determined according to the control ID sub-field. Specifically, the A-Control sub-field may have Figure 27 the format shown in (a). In addition, the control sub-field included in the A-Control sub-field may have the format shown in Figure 27 (b).

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

[0242] A wireless communication terminal may insert control sub-fields of an A-Control sub-field into the A-Control sub-field in the order according to their control IDs. Specifically, the wireless communication terminal may insert the control sub-fields of the A-Control sub-field into the A-Control sub-field in ascending order of the control IDs. In another specific embodiment, the wireless communication terminal may insert the control sub-fields of the A-Control sub-field into the A-Control sub-field in descending order of the control IDs. When the control sub-fields are inserted into the A-Control sub-field in the order sorted according to their control IDs, a wireless communication terminal decoding the A-Control sub-field may determine corresponding bits as padding bits when the values of the control ID fields in the A-Control sub-field are continuously 0. In a specific embodiment, after the control ID sub-field with 0 is decoded, when 0 is decoded again at the position corresponding to the control ID sub-field, the wireless communication terminal decoding the A-Control sub-field may determine that there is no additional control information to be decoded. Additionally, when 0 is decoded at the position corresponding to the control ID sub-field in the reverse order of the control ID sorting order, the wireless communication terminal decoding the control sub-field may determine that there is no control information to be further decoded.

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

[0244] Figure 28 Shows the format of an A-Control sub-field of a control sub-field 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. Additionally, the information indicating whether the corresponding control field is the last control subfield included in the A-Control subfield may be referred to as an end-of-control field. In this embodiment, a wireless communication terminal that decodes the A-Control subfield may stop decoding the A-Control subfield based on the end-of-control field. Specifically, when the end-of-control 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 Figure 28 shown.

[0246] The length of the HE variant transmitted by a wireless communication terminal according to an embodiment of the present invention may be variable. This is because when the fields of the HE variant are fixed, the wireless communication terminal may not be able to insert all necessary control information into the HE variant fields. This will be described with reference to Figures 29 to 32 this.

[0247] Figure 29 FIG. shows the frame format of the HT control field and the HE variant format according to another embodiment of the present invention.

[0248] Specifically, a wireless communication terminal may insert multiple HE variants into the HT control field to transmit 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 the existence of 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, a wireless communication terminal that decodes the HT control field may decode the subsequent bits into an HE variant after the corresponding HE variant. The More A-Control subfield may be placed in the last bit of the HE variant. Additionally, the More A-Control subfield may be placed in the first bit of the A-Control subfield. Additionally, the More A-Control subfield may be placed immediately after the two bits indicating the variant included in the A-Control subfield. Furthermore, 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. Additionally, 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. Further, 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 Figure 29 shown.

[0250] Figure 30 FIG. shows the frame format of the HT control field and the HE variant format according to another embodiment of the present invention.

[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 decoding 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 specific format of the specific HE control subfield may be as Figure 30 shown.

[0252] Figure 31 FIG. shows the frame format of the HT control field and the HE variant format according to another embodiment of the present invention.

[0253] When the length of the HE variant transmitted by the wireless communication terminal is variable, the wireless communication terminal may transmit the HE variant by inserting the above control end field into the control subfield. The wireless communication terminal decoding the HT control field may determine the end of the HT control field based on the control end field. The specific format of the specific HE control subfield may be as Figure 31 shown.

[0254] Figure 32 FIG. shows the frame format of the HT control field and the HE variant format according to another embodiment of the present invention.

[0255] When the length of the HE variant transmitted by a 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 transmit the HE subfield. Specifically, the length subfield may indicate - 1, which is the number of control subfields immediately 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 by which the A-Control subfield extends. For example, when the A-Control subfield is extended in units of bytes, the length subfield may indicate the total number of bytes of the A-Control subfield or the number of bytes extending the 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 the value obtained by dividing the length of the extended A-Control subfield by 32 bits or 30 bits, or may indicate the value obtained by dividing the total length of the A-Control subfield by 32 bits or 30 bits.

[0256] Figure 33 Shows the frame format of the HT control field and the HE variant format according to another embodiment of the present invention.

[0257] A wireless communication terminal may transmit control information through the body of a frame. Specifically, the wireless communication terminal may transmit the 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 restricted, and in this case, it is because there is control information required for the wireless communication terminal to receive the frame that is not included in the HT control. In a specific embodiment, the wireless communication terminal transmits a control ID field through the HT control field and transmits a control information field corresponding to the control ID field through the body of the frame. Specifically, the wireless communication terminal transmits a control ID field corresponding to a specific value through the HT control field and transmits a 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 a reference value, the wireless communication terminal transmits a control ID field through the HT control field and transmits a 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 transmit the control information field through the body of the frame. 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 body of the frame, the wireless communication terminal may insert the control information fields corresponding to the control ID fields into the body of the frame according to the sorting order of the control ID fields. InFigure 33 In an embodiment, there are control IDs m and 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 the 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 the control information corresponding to control ID m and the 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 at 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 send the information indicating the end of the control subfield as in the embodiment described in Figures 28 to 32 the reference.

[0259] In these embodiments, the wireless communication terminal that receives the frame can obtain the control ID field in the HT control field and obtain the 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 the transmission of these multiple wireless communication terminals to these multiple wireless communication terminals. At this time, the multiple wireless communication terminals can send a response 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 simultaneously. The operation of the wireless communication terminal based on the trigger frame will be described with reference to Figures 34 to 44 the description.

[0261] Figure 34 FIG. shows the format of the trigger frame according to an embodiment of the present invention.

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

[0263] Furthermore, 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 the multiple wireless communication terminals triggered by the trigger frame. The per-user information field may indicate information applied to each of the multiple wireless communication terminals triggered by the trigger frame. At this time, the number of per-user information fields may be determined according to the number of the multiple wireless communication terminals triggered by the trigger frame. The trigger frame may include a padding field. At this time, the padding field may allow the wireless communication terminal that receives the trigger frame to process the trigger frame for a time. The specific format of the trigger frame may be as Figure 34 shown.

[0264] Figure 35 shows 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.

[0265] The common information field may include a length field based on the length of the triggered PPDU or indicating the length of the L-SIG length field of the triggered PPDU. In this case, the length field may be a 12-bit field. Additionally, the common information field may include a concatenation indication field that indicates the existence of a subsequent trigger frame after the trigger frame. The common information field may include a CS required field that indicates whether channel sensing is required when transmitting the triggered PPDU. In this case, channel sensing may include virtual channel sensing for determining whether the NAV is set and energy detection (ED). Additionally, the trigger frame may include a HE-SIG-A information field that indicates the information to be inserted in the HE-SIG-A field of the triggered PPDU. In this case, information that can be self-identified by the wireless communication terminal that receives the trigger frame may be omitted from the trigger frame. Additionally, the trigger frame may include a CP and LTF type field that indicates the combination of the LTF and cyclic prefix (CP) of the triggered PPDU. Additionally, the trigger frame may include a trigger type field that indicates the type of the trigger frame. In this case, the type of the trigger frame may indicate any one of a basic trigger, beamforming report, polling trigger, MU-BAR, and MU-RTS. Additionally, 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 the form shown in Figure 35 (a).

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

[0267] Figure 36 Shows the common information field and per-user information field of a trigger frame according to another embodiment of the present invention.

[0268] When a wireless communication terminal triggered by a trigger frame transmits a trigger-based PPDU, the common information field may include a spatial reuse field that 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. Additionally, when a wireless communication terminal triggered by a trigger frame transmits a trigger-based PPDU, the common information field may include a BW field that indicates the value to be inserted by the corresponding wireless communication terminal in the BW field of the HE-SIG-A. Additionally, when a wireless communication terminal triggered by a trigger frame transmits a trigger-based PPDU, the common information field may include a MU MIMO LTF mode field that indicates the MU MIMO LTF mode to be used by the corresponding wireless communication terminal. Additionally, when a wireless communication terminal triggered by a trigger frame transmits a trigger-based PPDU, the common information field may include an LTF number field that indicates the number of LTFs to be used by the corresponding wireless communication terminal. Additionally, when a wireless communication terminal triggered by a trigger frame transmits a trigger-based PPDU, the common information field may include an STBC field that indicates whether the wireless communication terminal uses STBC. Additionally, when a wireless communication terminal triggered by a trigger frame transmits a trigger-based PPDU, the common information field may include an LDPC additional symbol field that indicates whether there are LDPC additional symbols when using the corresponding wireless communication terminal. Additionally, when a wireless communication terminal triggered by a trigger frame transmits a trigger-based PPDU, the common information field may include an AP TX power field that indicates the transmission power to be used by the wireless communication terminal. Additionally, when a wireless communication terminal triggered by a trigger frame transmits a trigger-based PPDU, the common information field may include a packet extension field that indicates information about the packet extension of the PPDU transmitted by the corresponding wireless communication terminal. Other fields included in the common information field may be the same as those described in reference Figure 35 (a). Specifically, the common information field may be the same as that of Figure 35 (a).

[0269] When a 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 that indicates the RSSI value to be targeted by the wireless communication terminal.

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

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

[0272] In addition, when a wireless communication terminal acting 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 can be sent. At this time, a wireless communication terminal acting as an AP can trigger the GCR BlockACK transmission of multiple wireless communication terminals through a trigger frame. For this purpose, the common information field of the trigger frame can include information related to GCR. At this time, the trigger frame type can be the MU-BAR type for GCR or the MU-BAR type. Specifically, when the type of the trigger frame is the MU-BAR type for GCR or the MU-BAR type, the common information field of the trigger frame can include a GCR indication field, and the GCR indication field indicates whether the trigger frame is the MU-BAR for GCR. In addition, the common information field of the trigger frame can include a GCR address field, and the GCR address field indicates the address of the GCR group triggered by the trigger frame. Specifically, the common information field included in the MU-BAR type trigger frame can be the same as that in Figure 37 the embodiment of (a).

[0273] In addition, the per-user information field related to triggering of the trigger frame may include a BAR control field, and the BAR control field includes information about BAR frame control. In addition, the per-user information field related to triggering of the trigger frame may include a BAR information field, and the BAR information field includes information about the BAR frame. In this specific embodiment, the BAR control field and the BAR information field may have 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, a wireless communication terminal may use the MU-BAR type or the MU-BAR type trigger frame for GCR by omitting the information included in the common information related to triggering of the trigger frame of the BlockAckReq type. Specifically, the wireless communication terminal inserts a GCR indication field in the common information related to triggering of the trigger frame of the BlockAckReq type and omits the GCR indication field in the BAR control field. In another specific embodiment, the wireless communication terminal may insert a GCR address field in the common information field related to triggering 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 common information field related to triggering and omits the GCR address field in the BAR information field.

[0274] Figure 38 Shows the format of the common information field related to triggering of the MU-BAR type trigger frame according to an embodiment of the present invention.

[0275] In a specific embodiment of the present invention, when the type of the trigger frame is the MU-BAR type or the MU-BAR type for GCR, the common information field related to triggering of the trigger frame may only include 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 according to whether the value of the GCR address field is the 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 through the start sequence control value or TID value requested by the MU-BAR. At this time, the wireless communication terminal that receives the trigger frame may determine whether the trigger frame is a MU-BAR type trigger frame for GCR through the start sequence control value or TID value requested by the MU-BAR.

[0277] In addition, even if the wireless communication terminal that receives 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 that receives the trigger frame, the wireless communication terminal that receives the trigger frame may also determine that the transmission is not triggered by the GCR BlockACK.

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

[0279] Figure 39 Show the format of the MU-BAR type trigger frame for GCR according to an embodiment of the present invention.

[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 a 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 that of Figure 39 the embodiment.

[0281] Figure 40 Show the format of the MU-BAR type trigger frame for GCR according to an embodiment of the present invention.

[0282] A wireless communication terminal may set the RA field of a MU-BAR type trigger frame for GCR to a broadcast address. At this time, the wireless communication terminal may set the GCR address field to the GCR address 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 a broadcast address, the wireless communication terminal may request an ACK frame other than the GCR BlockACK from the 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 a broadcast address, the wireless communication terminal may 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 may be the same as that of Figure 40 in the embodiment.

[0283] Figure 41 Shows the format of the BAR control field and the coding values of the BlockACKReq variants according to an embodiment of the present invention.

[0284] As described above, when the trigger frame is of the MU-BAR type, the trigger-related per-user information field of the trigger frame may include a BAR control field. At this time, multiple bits included in the trigger-related per-user information field may indicate variants of the BlcokACKReq. Specifically, the Multi-TID subfield, the compressed bitmap subfield, and the GCR subfield included in the trigger-related per-user information field may indicate variants of the BlcokACKReq. For example, when the value of the Multi-TID subfield is 0, the value of the compressed 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 the MU-BAR type trigger frame requests a GCR BlockAck, the MU-BAR type trigger frame may request the 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 the GCRBlockACK 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 compressed bitmap subfield may be 0 or 1. In a specific embodiment, the format of the BAR control field may be the same as that of Figure 41Same as in (a). Additionally, the coding value of the BlockACKReq variant can be as shown in Figure 41 (b).

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

[0287] Figure 42 Shows the format of the BAR information field according to an embodiment of the present invention.

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

[0289] Figure 43 Shows the BAR information field according to another embodiment of the present invention.

[0290] When the type of the trigger frame is the MU-BAR type and the wireless communication terminal requests ACKs for multiple TIDs, the wireless communication terminal may generate and transmit BAR information fields classified by TID. Specifically, when the type of the trigger frame is the MU-BAR type for GCR and the wireless communication terminal requests ACKs for multiple TIDs, the wireless communication terminal may generate and transmit 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 through the 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 that of Figure 43 in the embodiment. The length of the BAR information field may vary depending on the number of TIDs for which ACKs are requested. Specifically, the length of the trigger-related per-user information field may vary depending on the number of TIDs for which ACKs are requested. Therefore, the length of the per-user information field may vary depending on the number of TIDs for which ACKs are requested. The wireless communication terminal that transmits 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 that receives 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] Figure 44 FIG. shows a trigger frame structure according to another embodiment of the present invention.

[0292] The trigger frame may have a format as described in Figure 34 . At this time, the formats of the common information field and the per-user information field may be the same as any of those in the embodiments described with reference to Figures 35 to 36 . In addition, the format of the trigger-related per-user information field may be the same as that in the embodiment described with reference to Figure 37 . Further, the format of the trigger-related common information field may be the same as that in the embodiments described with reference to Figure 37 and Figure 38 . In addition, the format of the BAR information field may be the same as that in the embodiment described with reference to Figure 43 .

[0293] Figure 45 FIG. shows an operation of a wireless communication terminal according to an embodiment of the present invention.

[0294] The wireless communication terminal receives a 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 the case where the received PPDU lacks information for determining the BSS that transmitted 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 the wireless communication terminal acting as an AP receives a trigger-based PPDU from a wireless communication terminal that is not triggered by the wireless communication terminal acting as an AP, the wireless communication terminal acting as an AP can identify the corresponding PPDU as an inter-BSS PPDU. In a specific embodiment, when the wireless communication terminal acting as an AP does not transmit a trigger frame but receives a trigger-based PPDU, the wireless communication terminal acting as an AP can identify the PPDU as an inter-BSS PPDU. Additionally, based on whether the received PPDU includes a trigger frame, the wireless communication terminal acting as an AP can determine whether the corresponding PPDU is a PPDU for downlink transmission. Specifically, the wireless communication terminal acting as an AP can identify whether the corresponding PPDU is an inter-BSS PPDU based on SR-related information. At this time, the SR-related information can be the SR field signaled through 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 limitations. In a specific embodiment, the wireless communication terminal can identify whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU according to the embodiments Figures 6 to 23 described. 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 can identify the corresponding PPDU as an inter-BSS PPDU.

[0297] A 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 a NAV.

[0298] In addition, when the PPDU received by the wireless communication terminal may not identify 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 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 not enter a power saving mode based on the BSS color signaled through the PPDU.

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

[0301] In addition, when the NAV is set by a PPDU that 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 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 a PPDU received by a wireless communication terminal may not be recognized as an inter-BSS PPDU or an intra-BSS PPDU can be as follows: Due to a BSS color conflict, it may not be possible to recognize 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 recognize 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 based on the BSS color signaled by the received PPDU. Specifically, if the wireless communication terminal cannot recognize 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 a 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 operation based on the BSS color 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 recognize whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on the BSS color, the wireless communication terminal may 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 may 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 operation based on the BSS color is not allowed, the wireless communication terminal may 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 recognize 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 a PPDU received by a wireless communication terminal may not be recognized 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 to which it is transmitted. Specifically, when a PPDU received by a wireless communication terminal is not recognized 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. Additionally, the case where a PPDU received by a wireless communication terminal is not recognized as an inter-BSS PPDU or an intra-BSS PPDU may be the following case: 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, a wireless communication terminal may transmit a PPDU by including signaling information indicating that an operation based on BSS color is not allowed in the signaling field of the PPDU. At this time, a wireless communication terminal that receives a PPDU including the corresponding signaling information may not perform an operation based on BSS color. In a specific embodiment, a wireless communication terminal may transmit a 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 an AP. For example, the predetermined value may be zero. Additionally, when a wireless communication terminal receives a PPDU indicating the predetermined value as the BSS color, the wireless communication terminal may not perform an operation based on BSS color. Specifically, when a 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 a wireless communication terminal receives a PPDU indicating a predetermined value in the BSS color, the wireless communication terminal may regard the PPDU as an intra-BSS PPDU. Therefore, when a 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 an indication of a BSS color including the BSS of the wireless communication terminal when communicating with another wireless communication terminal. At this time, when the wireless communication terminal does not receive information 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 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 signaling the BSS color, a 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 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 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 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 situation where the wireless communication terminal does not receive information signaling the BSS color may include the following situations: 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 situation where the wireless communication terminal does not receive information signaling the BSS color may include the following situations: 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, a PPDU signaling a predetermined value as the BSS color may not be recognized 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 a 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 in 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 the BSS color, the wireless communication terminal may not perform operations based on the BSS color. Specifically, when the wireless communication terminal receives a PPDU indicating a predetermined value as 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 as the BSS color, the wireless communication terminal may regard the PPDU as a BSS internal PPDU. Therefore, when the wireless communication terminal receives a PPDU indicating a predetermined value as the 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 operations of the wireless communication terminal may be the same as those of the embodiments described by referring to Figures 6 to 23 the embodiments of the embodiments described.

[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 methods, devices, and systems 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 having 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 such combination and modification is included within the scope of the present invention.

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

Claims

1. A station for wireless communication, the station comprising: a transceiver; and a processor, wherein the processor is configured to receive a Physical Layer Convergence Procedure (PLCP) Protocol Data Unit (PPDU) by using the transceiver, and when signaling information indicates that an operation based on a Basic Service Set (BSS) color is not allowed, not set a Network Allocation Vector (NAV) within the BSS by using the BSS color indicated by a signaling field of the PPDU, wherein the BSS color is an identifier of the BSS, wherein a value of the BSS color of the BSS to which the station belongs is obtained from a HE - operation element sent by an access point to which the station is associated, wherein the signaling information is sent from the access point, wherein the NAV within the BSS is different from a basic NAV and is a NAV set based on a PPDU within the BSS, wherein the basic NAV is set based on an inter - BSS PPDU, or a PPDU that cannot be recognized as an inter - BSS PPDU or a PPDU within the BSS, wherein within the BSS is the BSS including the station, and between the BSSs are BSSs different from the BSS within.

2. The station according to claim 1, wherein The PPDU includes a Media Access Control (MAC) frame, wherein the signaling field of the PPDU includes a Transmission Opportunity (TXOP) duration field, and wherein the MAC frame includes a duration field, wherein the TXOP duration field indicates information for setting the NAV within the BSS and the basic NAV, wherein the duration field indicates information for setting the NAV within the BSS and the basic NAV, wherein the processor is configured to, when the station obtains a valid signaling field of the MAC frame, not use the TXOP duration field for setting the NAV within the BSS or the basic NAV.

3. The station according to claim 1, wherein The processor is configured to signal that an operation based on the BSS color is not allowed when the station identifies that a BSS color conflict has occurred, wherein the BSS color conflict means 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 Media Access Control (MAC) frame.

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

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 station for wireless communication, the method comprising: receiving a Physical Layer Convergence Procedure (PLCP) Protocol Data Unit (PPDU), and when signaling information indicates that an operation based on a Basic Service Set (BSS) color is not allowed, not performing an operation based on the Basic Service Set (BSS) color, Wherein, the BSS color is an identifier of the BSS, Wherein, the signaling information is sent from the access point to which the station is associated, Wherein, the value of the BSS color of the BSS to which the station belongs is obtained from the HE - operation element sent by the access point, Wherein, when the signaling information indicates that the operation based on the BSS color is not allowed, the network allocation vector NAV within the BSS is not set by using the BSS color indicated by the signaling field of the PPDU, Wherein, the NAV within the BSS is different from the basic NAV and is the NAV set based on the PPDU within the BSS, Wherein, the basic NAV is set based on the inter - BSS PPDU or a PPDU that cannot be recognized as the inter - BSS PPDU or the intra - BSS PPDU, Wherein, the intra - BSS is the BSS including the station, and the inter - BSS is a BSS different from the intra - BSS.

9. The method according to claim 8, wherein The PPDU includes a media access control MAC frame, wherein the signaling field of the PPDU includes a transmission opportunity TXOP duration field, and wherein the MAC frame includes a duration field, Wherein, the TXOP duration field indicates information for setting the NAV within the BSS and the basic NAV, Wherein, the duration field indicates information for setting the NAV within the BSS and the basic NAV, Wherein, the method further includes not using the TXOP duration field for setting the NAV within the BSS 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 signaling that the operation based on the BSS color is not allowed when the station identifies that a BSS color conflict has occurred, Wherein, the BSS color conflict means 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 the address field of the 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 a power - saving operation based on the BSS color indicated by the signaling field of the PPDU, Wherein, the power - saving operation is an operation for the station to enter the sleep state until the received PPDU as an intra - BSS PPDU terminates.

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

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

Images