A wireless communication method and a wireless communication terminal

Abstract

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

Description

[0001] This application is a divisional application of patent application No. 201780015247.2 (PCT / KR2017 / 002407), filed with the China Patent Office on September 4, 2018, with an international application date of March 6, 2017, entitled "Wireless Communication Method and Wireless Communication Terminal in a Basic Service Set Overlapping with Another Basic Service Set". Technical Field

[0002] The present invention relates to a wireless communication method and a wireless communication terminal in the case of overlapping basic service sets. Background Technology

[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 smartphones, smart tablets, laptops, portable multimedia players, embedded devices, etc., to access the internet wirelessly in homes, offices, or specific service areas.

[0004] One of the most well-known wireless communication technologies is wireless LAN. Since using the 2.4 GHz frequency to support the initial wireless LAN technology, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 has commercialized or developed various technical standards. First, IEEE 802.11b supported a maximum communication speed of 11 Mbps when using the 2.4 GHz band. Following IEEE 802.11b, IEEE 802.11a, commercialized after IEEE 802.11b, used the 5 GHz band instead of the 2.4 GHz band, reducing interference compared to the significantly congested 2.4 GHz band, and increasing communication speeds up to a maximum of 54 Mbps through the use of Orthogonal Frequency Division Multiplexing (OFDM) technology. However, a drawback of IEEE 802.11a is its shorter communication range compared to IEEE 802.11b. Furthermore, IEEE 802.11g, similar to IEEE 802.11b, uses the 2.4 GHz frequency band to achieve a maximum communication speed of 54 Mbps and meets backward compatibility, which has attracted significant public attention. Moreover, it is superior to IEEE 802.11a in terms of communication range.

[0005] Furthermore, IEEE 802.11n has been provided as a technical standard established to overcome the limitations of communication speed, a weakness identified in wireless LANs. IEEE 802.11n aims to improve network speed and reliability and extend the operating distance of wireless networks. More specifically, IEEE 802.11n supports high throughput (HT) data processing speeds of up to 540 Mbps or higher, and further utilizes multiple antennas on both sides of the transmitting and receiving units to minimize transmission errors and optimize data speed using Multiple-Input Multiple-Output (MIMO) technology. Additionally, the standard can use coding schemes that transmit multiple overlapping copies to improve data reliability.

[0006] With the active supply of wireless LANs and the further diversification of applications using them, the need for new wireless LAN systems to support higher throughput (Very High Throughput (VHT)) than those supported by IEEE 802.11n has gained public attention. Among these, IEEE 802.11ac supports a wide bandwidth (80 to 160 MHz) at the 5 GHz frequency. The IEEE 802.11ac standard is defined only within the 5 GHz band, but initial 11ac chipsets will even support operation in the 2.4 GHz band for backward compatibility with existing 2.4 GHz band products. Theoretically, according to this standard, wireless LAN speeds across multiple stations can reach up to 1 Gbps and maximum single-link speeds can reach up to 500 Mbps. This is achieved through concepts that expand the wireless interface accepted by 802.11n, such as wider wireless frequency bandwidth (up to 160 MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high-density modulation (up to 256 QAM). Additionally, IEEE 802.11ad has been proposed as a solution to transmit data using the 60GHz band instead of the existing 2.4GHz / 5GHz band. IEEE 802.11ad is a standard that uses beamforming technology to provide speeds up to 7Gbps and is suitable for transmitting high-bitrate motion picture streams such as massive amounts of data or uncompressed HD video. However, a disadvantage of the 60GHz band is that it is difficult to penetrate obstacles, meaning it can only be used between devices in short-distance spaces.

[0007] Meanwhile, in recent years, as the next-generation wireless communication technology standard following 802.11ac and 802.11ad, discussions have continued regarding high-efficiency and high-performance wireless communication technologies for high-density environments. In other words, the next-generation wireless communication technology environment requires providing high-frequency-efficiency communication indoors / outdoors in the presence of high-density terminals and basic terminals, and necessitates various technologies to achieve this communication.

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

[0009] Technical issues

[0010] The embodiments of the present invention are intended to provide a wireless communication method and a wireless communication terminal in the case of overlapping basic service sets.

[0011] Technical solution

[0012] According to an embodiment of the present invention, a wireless communication terminal for wireless communication includes: a transceiver; and a processor. The processor is configured to transmit a BSS color indicating the BSS of the wireless communication terminal when communicating with another wireless communication terminal via the transceiver, and to transmit a predetermined value as the BSS color when the wireless communication terminal fails to receive information indicating the BSS color.

[0013] When a wireless communication terminal fails to establish any association with a wireless communication terminal acting as an access point (AP), the processor can send a predetermined value as the BSS color.

[0014] When a wireless communication terminal receives a signaling message indicating that operation based on BSS color is not allowed, the processor can be configured to send a predetermined value as the BSS color.

[0015] The preset value can be 0.

[0016] PLCP protocol data units (PPDUs) that use a predetermined value as the BSS color to signal notification can be identified as inter-BSS PPDUs or intra-BSS PPDUs without being based on the predetermined BSS color. Intra-BSS PPDUs can indicate PPDUs sent from the same BSS as the BSS that includes the wireless communication terminal, while inter-BSS PPDUs can indicate PPDUs sent from a BSS other than the BSS that includes 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 PLCP protocol data units (PPDUs) via the transceiver and access the channel based on whether the PPDU is an inter-BSS PPDU or an intra-BSS PPDU, wherein 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] A PPDU can be identified as an inter-BSS PPDU when it satisfies both the inter-BSS PPDU condition and the intra-BSS PPDU condition.

[0019] When a PPDU is not identified 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. It can set the intra-BSS NAV based on a PPDU sent from the same BSS as the wireless communication terminal, and it 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 identify whether a PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color, the processor can be configured to set the intra-BSS Network Allocation Vector (NAV) not based on the BSS color and the TXOP duration field of the HE-SIG-A field of the PPDU, but based on the PPDU sent from the same BSS as the wireless communication terminal's BSS.

[0021] When a signaling message indicating that operation based on BSS color is not allowed is received, the processor can be configured to set the NAV within the BSS without based on the TXOP duration field of the HE-SIG-A field of the PPDU and the BSS color.

[0022] When a wireless communication terminal identifies that the BSS color of its own BSS is the same as the BSS color of another BSS, the NAV within the BSS can be set without relying on the BSS color and the TXOP duration field of the HE-SIG-A field of the PPDU.

[0023] When a wireless communication terminal cannot identify whether a PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on BSS color, the processor can be configured to enter a power-saving mode without relying on 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 that is 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 that includes 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 a PPDU includes a trigger frame based on information related to space reuse (SR) operations included in the PPDU.

[0027] Based on information related to the SR operation included in the PPDU, indicating whether the SR operation is restrictedly allowed or delayed while the PPDU is being transmitted, the processor can be configured to determine whether the PPDU includes a trigger frame.

[0028] According to an embodiment of the present invention, a wireless communication terminal for wireless communication includes: a transceiver; and a processor. The processor is configured to receive PLCP processing data units (PPDUs) via the transceiver, and not perform BSS color-based operations 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 the SR operation for the PPDU.

[0030] When the BSS color indicated by the PPDU is a predetermined value, the processor can treat the PPDU as a PPDU within the BSS.

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

[0032] Beneficial effects

[0033] Embodiments of the present invention provide a wireless communication method and a wireless communication terminal in the case of overlapping basic service sets. Attached Figure Description

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

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

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

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

[0038] Figure 5 The process of setting up access points and links at a site according to an embodiment of the present invention is illustrated.

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

[0040] Figure 7 This illustrates a wireless communication terminal according to an embodiment of the present invention entering a power-saving mode during color conflict between BSSs.

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

[0042] Figure 9 This illustrates 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 This illustration shows the operation of a wireless communication terminal according to an embodiment of the present invention in determining whether to reset the NAV based on the CF-End frame when a BSS color conflict occurs.

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

[0045] Figure 12 This illustrates the operation of a wireless communication terminal identifying BSS color conflicts according to an embodiment of the present invention.

[0046] Figure 13 The MAC frame format that allows transmission (CTS) frames and ACK frames according to an embodiment of the present invention is shown.

[0047] Figure 14 The operation of setting NAV based on RTS frames and CTS frames is illustrated in an embodiment of the present invention.

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

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

[0050] Figure 17 This illustrates a wireless communication terminal according to an embodiment of the present invention. Figures 15 to 16 The implementation examples are used to set up the operation of NAV.

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

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

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

[0054] Figure 21 This illustrates a method by which a wireless communication terminal determines whether a PPDU is an inter-BSS PPDU or an intra-BSS PPDU when a PPDU received by a wireless communication terminal according to an embodiment of the present invention satisfies both inter-BSS PPDU conditions and intra-BSS PPDU conditions.

[0055] Figure 22 This illustrates a scenario 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 This illustrates a situation where, when a wireless communication terminal according to an embodiment of the present invention is included in a BSS corresponding to a set of multiple BSSIDs, the wireless communication terminal enters a power-saving state based on the MAC header of a frame received by the wireless communication terminal.

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

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

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

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

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

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

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

[0064] Figure 35 The format of the public information field and the per-user information field of the trigger frame according to an embodiment of the present invention is shown.

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

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

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

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

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

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

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

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

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

[0074] Figure 45 The operation of a wireless communication terminal according to an embodiment of the present invention is illustrated. Detailed Implementation

[0075] Preferred embodiments of the invention will be described in more detail below with reference to the accompanying drawings. However, the invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Parts irrelevant to the description have been omitted from the drawings in order to clearly illustrate the invention, and similar reference numerals refer to similar elements throughout.

[0076] Furthermore, when describing something as including (or containing or having) some elements, it should be understood that, without specific limitations, it may include (or contain or have) only those elements, or it may include (or contain or have) other elements as well as those elements.

[0077] This application claims priority and benefit to Korean Patent Applications No. 10-2016-0026684 (2016.03.04), No. 10-2016-0029975 (2016.03.12), No. 10-2016-0044465 (2016.04.11), No. 10-2016-0057597 (2016.05.11) and No. 10-2016-0114821 (2016.09.07) filed with the Korean Intellectual Property Office, and the embodiments and references described in the respective applications are included in the detailed description of this application.

[0078] Figure 1 This is a diagram illustrating a wireless communication system according to an embodiment of the present invention. For ease of description, embodiments of the present invention are described using a wireless LAN system. A wireless LAN system includes one or more Basic Service Sets (BSSs), and a BSS represents a collection of devices that have successfully synchronized with each other to communicate. Generally, BSSs can be classified into Infrastructure BSSs and Standalone BSSs (IBSSs). Figure 1 The diagram illustrates the infrastructure BSS between them.

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

[0080] A station (STA) is a predetermined device that includes a Media Access Control (MAC) conforming to the IEEE 802.11 standard and a physical layer interface for wireless media, and broadly includes non-access point (non-AP) stations and access points (APs). Additionally, in this specification, the term "terminal" may be used to refer to a wireless LAN communication device including concepts such as a non-AP STA or AP, or both. 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 can generate frames to be transmitted via the wireless network or process frames received via the wireless network, and further performs various processes for controlling the station. Furthermore, the transceiver is functionally connected to the processor and transmits and receives frames via the wireless network used for the station.

[0081] An access point (AP) is an entity that provides access to a distribution system (DS) for its associated stations via a wireless medium. In a base station infrastructure (BSS), communication between non-AP stations is generally performed via the AP; however, direct communication can also be achieved between non-AP stations when a direct link is configured. Furthermore, in this invention, the AP is used as a concept encompassing a Personal BSS Coordination Point (PCP) and can be broadly categorized as including a centralized controller, base station (BS), node B, base transceiver system (BTS), and site controller.

[0082] Multiple infrastructure BSSs can be interconnected through a distribution system (DS). In this case, the multiple BSSs connected through the distribution system are referred to as an Extended Service Set (ESS).

[0083] Figure 2 The illustration shows a standalone BSS as a wireless communication system according to another embodiment of the present invention. For ease of description, another embodiment of the present invention is described using a wireless LAN system. Figure 2 In the embodiment, the pair with Figure 1 The same or corresponding parts of the embodiments are described repeatedly.

[0084] because Figure 2 The BSS3 shown in the diagram is a standalone BSS and does not include an access point (AP), so all stations STA6 and STA7 are not connected to the AP. A standalone BSS is not permitted to access the distribution system and form a complete network. Within a standalone BSS, the corresponding stations STA6 and STA7 can connect directly to each other.

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

[0086] like Figure 3 As illustrated, 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, transceiver 120 transmits and receives wireless signals such as wireless LAN physical layer frames and can be embedded in station 100 or configured externally. According to this embodiment, transceiver 120 may include at least one transmit and receive module using different frequency bands. For example, transceiver 120 may include transmit and receive modules with different frequency bands such as 2.4 GHz, 5 GHz, and 60 GHz. According to an embodiment, station 100 may include transmit and receive modules using 6 GHz or higher frequency bands and transmit and receive modules using 6 GHz or lower frequency bands. The corresponding transmit and receive modules can perform wireless communication with the AP or external station according to the wireless LAN standard of the frequency band supported by the corresponding transmit and receive module. Transceiver 120 may operate only one transmit and receive module at a time or operate multiple transmit and receive modules simultaneously, depending on the performance and requirements of station 100. When station 100 includes multiple transmit and receive modules, each transmit and receive module may be implemented as an independent element or multiple modules may be integrated into a single chip.

[0088] Next, the user interface unit 140 includes various types of input / output devices disposed in the station 100. That is, the user interface unit 140 can receive user input by using various input devices, and the processor 110 can control the station 100 based on the received user input. In addition, the user interface unit 140 can execute outputs based on commands from 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 can output various display objects based on control commands from the processor 110, such as content executed by the processor 110 or a user interface. Additionally, the memory 160 stores the control program used in the station 100 and data obtained from various results. The control program may include the access program required for the station 100 to connect to an AP or an external station.

[0090] The processor 110 of the present invention can execute various commands or programs and process data in station 100. Additionally, the processor 110 can control corresponding units of 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 an AP stored in memory 160 and receive communication configuration messages sent by the AP. Furthermore, the processor 110 can read information about priority conditions of station 100 included in the communication configuration messages and request access to the AP based on the information about the priority conditions of station 100. The processor 110 of the present invention can represent the main control unit of station 100, and according to this embodiment, the processor 110 can represent a control unit for individually controlling a component of station 100 (e.g., transceiver 120, etc.). The processor 110 can be a modulator and / or demodulator that modulates wireless signals transmitted to transceiver 120 and demodulates wireless signals received from transceiver 120. The processor 110 controls various operations of wireless signal transmission / reception of station 100 according to an embodiment of the present invention. Detailed embodiments thereof will be described below.

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

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

[0093] like Figure 4 As illustrated, the AP 200 according to an embodiment of the present invention may include a processor 210, a transceiver 220, and a memory 260. Figure 4 In the AP 200 components, the terms related to... Figure 2 Repeated descriptions of the same or corresponding parts of the components of station 100.

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

[0095] Next, memory 260 stores the control program used in AP 200 and data obtained from various results. The control program may include an access program for managing station access. Additionally, processor 210 can control corresponding units of AP 200 and control data transmission / reception between these units. According to an embodiment of the invention, processor 210 can execute a program for accessing stations stored in memory 260 and send communication configuration messages for one or more stations. In this case, the communication configuration message may include information about access priority conditions for the corresponding station. Furthermore, processor 210 performs access configuration according to the station's access request. Processor 210 may be a modulator and / or demodulator that modulates wireless signals transmitted to transceiver 220 and demodulates wireless signals received from transceiver 220. Processor 210 controls various operations such as the transmission / reception of radio signals by AP 200 according to a first embodiment of the invention. Detailed embodiments thereof will be described below.

[0096] Figure 5 This is a schematic diagram illustrating the process of setting up the link between the STA and the AP.

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

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

[0099] Simultaneously, an 802.1X-based authentication step (S111) and an IP address acquisition step via DHCP can be additionally performed. Figure 5 In this context, authentication server 300 is a server that processes 802.1X-based authentication for STA 100 and can exist in physical association with AP 200 or as a standalone server.

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

[0101] Due to the proliferation of mobile devices and the availability of wireless communication, wireless communication terminals are increasingly communicating in dense environments. In particular, the number of wireless communication terminals communicating in environments with overlapping network segment controllers (BSS) is increasing. When multiple BSSs overlap, the communication efficiency of wireless communication terminals may be degraded due to interference with other wireless communication terminals. Specifically, when using frequency bands through a contention process, wireless communication terminals may not even be able to guarantee transmission opportunities due to interference with other wireless communication terminals. To address this issue, wireless communication terminals can perform spatial reuse (SR) operations. Specifically, SR operations may include accessing the channel based on whether the received frame is a MAC frame transmitted from a BSS including the wireless communication terminal or from another BSS. For ease of description, when a frame is used in the following description without any further description, it is assumed to refer to a MAC frame.

[0102] In specific embodiments, access channel operations may include setting and resetting NAV, CCA operations, and deferral operations. For example, the wireless communication terminal may adjust the Free Channel Assessment (CCA) threshold based on whether the frame received by the wireless communication terminal is transmitted from the BSS (Band of Service) including the wireless communication terminal or from the OBSS (On-Board Service). Additionally, the wireless communication terminal may adjust the transmit power of the PPDU to be transmitted based on the CCA threshold adjustment during SR (Send-On) operations.

[0103] Specifically, the wireless communication terminal can apply a CCA threshold based on 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 can be applied based on whether the PPDU received while transmitting the payload of the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU. Furthermore, the wireless communication terminal can receive a first PPDU and a second PPDU simultaneously while applying the CCA threshold based on whether the first PPDU is an inter-BSS PPDU or an intra-BSS PPDU. Specifically, the wireless communication terminal can apply a CCA threshold based on 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 can receive an intra-BSS PPDU. In this case, the wireless communication terminal can 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 a PPDU within the BSS and applies the CCA threshold corresponding to the PPDU within the BSS, the wireless communication terminal may receive an inter-BSS PPDU before the transmission of the intra-BSS PPDU is complete. In this case, the wireless communication terminal can maintain the CCA threshold corresponding to the intra-BSS PPDU until the transmission of the intra-BSS PPDU is complete. Specifically, the wireless communication terminal may choose not to apply the CCA threshold corresponding to the inter-BSS PPDU until the transmission of the intra-BSS PPDU is complete. In the above operation, the CCA threshold corresponding to the inter-BSS PPDU can be equal to or greater than the CCA threshold corresponding to the intra-BSS PPDU.

[0104] In addition, the wireless communication terminal can enter power-saving mode based on whether the frame received by the wireless communication terminal is sent from the BSS including the wireless communication terminal or from the OBSS.

[0105] For ease of explanation, the BSS including the wireless communication terminal is referred to as intra-BSS, and the basic service set overlapping with that within the BSS is referred to as the Overlapping Basic Service Set (OBSS). Furthermore, a BSS different from the intra-BSS is referred to as inter-BSS. Frames transmitted within the BSS are called intra-BSS frames, and frames transmitted within the OBSS are called OBSS frames or inter-BSS frames. Additionally, PPDUs transmitted from within the BSS are called intra-BSS PPDUs, and PPDUs transmitted from the OBSS are called OBSS PPDUs or inter-BSS PPDUs.

[0106] Figure 6 This illustrates a wireless communication terminal according to an embodiment of the present invention entering a power-saving mode based on BSS color.

[0107] When the receiver of a PPDU transmitted within the BSS does not include a non-AP wireless communication terminal, the non-AP wireless communication terminal can enter power-saving mode. Specifically, the non-AP wireless communication terminal can enter power-saving mode under the following conditions: When the PPDU received by the non-AP wireless communication terminal is an 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 via the PPDU, and it is not a broadcast address indicating the non-AP wireless communication terminal, the non-AP wireless communication terminal can enter power-saving mode. Additionally, when the PPDU received by the non-AP wireless communication terminal is any one of HE-MU-PPDU, HE-SU-PPDU, and 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 power-saving mode. Additionally, when the PPDU received by a non-AP wireless communication terminal is a triggered PPDU and the BSS color value indicated by the PPDU signaling indicates the BSS associated with the non-AP wireless communication terminal, the non-AP wireless communication terminal can enter power-saving mode. In a specific embodiment, the non-AP wireless communication terminal can determine whether the PPDU is for uplink transmission based on the UL_FLAG value of RXVECTOR. Furthermore, the non-AP wireless communication terminal can determine whether it is included in the address of the receiving wireless communication terminal that sent the PPDU signal based on the STA_ID_LIST of RXVECTOR. Furthermore, the non-AP wireless communication terminal can leave power-saving mode without sending a corresponding PPDU. In this case, RXVECTOR is a set of parameters indicating the information of the PPDU received by the MAC layer module from the physical layer module when the wireless communication terminal receives the PPDU.

[0108] Additionally, non-AP wireless communication terminals can determine that the wireless medium is busy in power-saving mode. Therefore, the wireless communication terminal does not access the wireless medium in power-saving mode. Furthermore, non-AP wireless communication terminals can operate the Network Allocation Vector (NAV) timer in power-saving mode and access the wireless medium when the NAV timer expires. Also, when the power-saving mode option of a non-AP wireless communication terminal is activated and the current state of the non-AP wireless communication terminal is not in power-saving mode, the non-AP wireless communication terminal can enter power-saving mode. In this case, the power-saving mode option can be activated when the value of dot11IntraPPDUPowerSaveOptionActivated is True. Furthermore, power-saving mode is referred to as sleep mode, and the state not in power-saving mode can be referred to as wake-up mode.

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

[0110] Because the size of the field indicating BSS color is limited, it is possible for different BSSs to be set to the same BSS color. For ease of description, the situation where different BSSs correspond to the same BSS color is called inter-BSS color conflict or BSS color conflict.

[0111] Figure 7 This illustrates a wireless communication terminal according to an embodiment of the present invention entering a power-saving mode during color conflict between BSSs.

[0112] When a color conflict occurs between BSSs and a non-AP wireless communication terminal receives a BSS PPDU that sends a signal notifying that the BSS color is the same as the BSS color associated with the non-AP wireless communication terminal, the non-AP wireless communication terminal can enter power-saving mode. Therefore, the non-AP wireless communication terminal can function as if... Figure 7 In this embodiment, PPDUs sent by APs associated with non-AP wireless communication terminals are not received. In this case, the BSS color notified via the PPDU can be the BSS color notified via the BSS color field of the PPDU. Specifically, the BSS color notified via the PPDU can be the BSS color notified via the HE-SIG-A BSS color field of the PPDU.

[0113] Therefore, when a wireless communication terminal cannot identify the BSS to which a corresponding PPDU was sent based on the BSS color notified via the PPDU, the wireless communication terminal may not perform operations based on the BSS color. Specifically, when a wireless communication terminal cannot identify the BSS based on the BSS color notified via the PPDU, it may not perform operations based on a BSS color that is the same as the inter-BSS color. For example, when a wireless communication terminal cannot identify the BSS based on the BSS color notified via the PPDU, even if the wireless communication terminal receives a PPDU indicating a BSS color that is the same as the inter-BSS color, the wireless communication terminal may not consider 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 via the PPDU, the non-AP wireless communication terminal can enter power-saving mode without relying on the BSS color signaled via the PPDU. Specifically, when a non-AP wireless communication terminal identifies a BSS color conflict, it can enter power-saving mode without relying on the BSS color signaled via the PPDU. In a specific embodiment, from the time the BSS color conflict is identified to a predetermined time point, the non-AP wireless communication terminal can enter power-saving mode without relying on the BSS color value. In another specific embodiment, from the time the BSS color conflict is identified to a predetermined time point, the non-AP wireless communication terminal can operate in intra-PPDU power-saving mode without relying on the BSS color value. Furthermore, the predetermined time point can indicate the time when the BSS color conflict is resolved. In another specific embodiment, the predetermined time point can be the time when the association between the AP and the non-AP wireless communication terminal is severed. In yet another specific embodiment, from the time the non-AP wireless communication terminal detects a BSS color conflict, the non-AP wireless communication terminal can stop entering power-saving mode.

[0115] Furthermore, 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 notified via the PPDU signal, 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 notified via the PPDU signal, 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 then the method by which the wireless communication terminal sets the NAV when it cannot identify whether a PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on the BSS color notified via the PPDU signal will be described.

[0116] A wireless communication terminal can maintain two NAVs: an intra-BSS NAV set based on PPDUs identified as intra-BSS PPDUs and a basic NAV set based on PPDUs identified as inter-BSS PPDUs. In this case, the wireless communication terminal can set the basic NAV based on PPDUs that may not be identified as inter-BSS or intra-BSS PPDUs. Specifically, the wireless communication terminal can maintain two NAVs through the following operations.

[0117] When a wireless communication terminal receives at least one valid frame from a PSDU and identifies that frame as an intra-BSS frame, the wireless communication terminal can set the intra-BSS NAV based on the PSDU's valid duration field value. Furthermore, when a wireless communication terminal receives at least one valid frame from a PSDU and identifies that frame as an inter-BSS frame, the wireless communication terminal can set the basic NAV based on the PSDU's valid duration field value. Additionally, when a wireless communication terminal receives at least one valid frame from a PSDU but may not identify that frame as an intra-BSS or inter-BSS frame, the wireless communication terminal can set the basic NAV based on the PSDU's valid duration field value.

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

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

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

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

[0122] When a wireless communication terminal receives a CF-End frame, it can reset the NAV. In this case, the wireless communication terminal can determine whether to reset the NAV based on the BSS from which it sent the CF-End frame. Specifically, when the BSS from which it sent the PPDU that sets the currently set NAV is the same as the BSS from which it sent the CF-End frame, the wireless communication terminal can reset the currently set NAV. Additionally, when the BSS from which it sent the PPDU that sets the currently set NAV is different from the BSS from which it sent the CF-End frame, 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 a BSS indicated by a set of multiple BSSIDs including BSSs or a BSSID within a BSS, and sets the most recent NAV by a PPDU sent from any of the BSSs indicated by a set of multiple BSSIDs including BSSs or a BSSID within a BSS, the wireless communication terminal may not reset the NAV. In another specific embodiment, when a wireless communication terminal receives a CF-End frame from a BSS that is one of the BSSs indicated by a set of multiple BSSIDs including BSSIDs within a BSS, and sets the most recent NAV by a PPDU that does not correspond to a BSS indicated by a set of multiple BSSIDs including BSSIDs between or within a BSS, the wireless communication terminal may not reset the NAV.

[0123] A trigger frame sent by the AP can trigger uplink transmission of the wireless communication terminal receiving the trigger frame. At this time, depending on certain conditions, the wireless communication terminal can start ULMU 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 can start ULMU 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 trigger-based PPDU is less than a predetermined value, the wireless communication terminal can start ULMU transmission based on the trigger frame without considering the NAV. Furthermore, when the NAV is set by a frame sent by another wireless communication terminal included in the BSS, the wireless communication terminal can start ULMU transmission based on the trigger frame without considering the NAV. Additionally, when the field indicating whether channel sensing is required in the trigger frame indicates that channel sensing is not required, the wireless communication terminal can start ULMU transmission based on the trigger frame without considering the NAV. Specifically, the field indicating whether channel sensing is required in the trigger frame can be a CS required field.

[0124] However, when NAV is set as in the embodiments described above, BSS color conflicts may occur. NAV settings and transmission operations of the wireless communication terminal may become problematic. (Refer to...) Figures 8 to 9 This will be described.

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

[0126] exist Figure 8 In this 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, which is included in the first BSS BSS1. At this time, the station STA identifies the inter-BSS frame as an intra-BSS frame based on the BSS color indicated by the HE-SIG-A field of the PPDU including the inter-BSS frame. The first station STA1 sets the intra-BSS NAV according to the value of the TXOP duration field of the signaling field of the PPDU including the inter-BSS frame. Then, the first station STA1 receives a trigger frame from the intra-BSS AP within the BSS. As described above, when the NAV is set by a frame sent by another wireless communication terminal included in the BSS, the wireless communication terminal can start UL MU transmission based on the trigger frame without considering the NAV. Therefore, the first station STA1 can start uplink transmission based on the trigger frame sent by the AP of the first BSS BSS1. At this time, because frames are being transmitted from the third station STA3 to the second station STA2, interference occurs in the second BSSSBSS2 based on the trigger frame transmitted by the first station STA1 due to the trigger-based UL frame. Therefore, a method is needed for operating wireless communication terminals that can minimize the impact of BSS color conflict when it occurs. For example, in Figure 8 In one embodiment, when the first station STA1 sets the basic NAV based on a frame sent by the second station STA2 instead of the intra-BSS NAV, interference occurring in the second BSS BSS2 due to transmissions through the first station STA1 can be prevented. (See reference...) Figure 9 This will be described.

[0127] Figure 9 This illustrates 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 mentioned above, the BSS color notified by the PPDU signal can be the BSS color notified by the BSS color field of the PPDU. Specifically, the BSS color notified by the PPDU signal can be the BSS color notified by the BSS color field of the PPDU's HE-SIG-A. Specifically, when the wireless communication terminal may not be able to determine 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 can identify BSS color conflicts. Furthermore, when the 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 PPDU's signaling field and other parameters and conditions of the RXVECTOR, the wireless communication terminal may not set the intra-BSS NAV based on the TXOP duration field indicated by the PPDU's signaling field. In a specific embodiment, when the 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 PPDU's signaling field, the wireless communication terminal may set the basic NAV based on the TXOP duration field indicated by the PPDU's signaling field. In this case, when the 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 PPDU's signaling field and other parameters and conditions of the RXVECTOR, the wireless communication terminal may set the basic NAV based on the TXOP duration field indicated by the PPDU's signaling field. In other words, when the wireless communication terminal cannot identify whether the received PPDU is an intra-BSS PPDU or an inter-BSS PPDU, the wireless communication terminal can set the basic NAV based on the PPDU. Specifically, when the PPDU received by the wireless communication terminal may not be identified as an intra-BSS PPDU or an inter-BSS PPDU, the wireless communication terminal can set the basic NAV based on the TXOP duration field of the corresponding PPDU. In this case, the TXOP duration field of the PPDU can be the TXOP duration field of the HE-SIG-A field.

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

[0130] exist Figure 9 In this 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. In this case, the first station STA1 can determine whether a PPDU might 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 might determine that a BSS color conflict has occurred. The first station STA1 receives an inter-BSS frame sent by the second station STA2, which is included in the first BSS BSS1. However, because the first station STA1 may not be able to 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 first station STA1 sets a basic NAV. Therefore, because the basic NAV is set even when the first station STA1 receives a trigger frame from the AP of the first BSS BSS1, the first station STA1 does not start uplink transmission based on a trigger.

[0131] As mentioned above, when a wireless communication terminal maintains two NAVs, it can reset the NAV based on the BSS of sending the CF-End frame and the BSS of sending the frame that sets the NAV. Therefore, when a BSS color conflict occurs, the operation of the wireless communication terminal in resetting the NAV via the CF-End frame may be problematic. (See reference...) Figure 10 and Figure 11 This will be described.

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

[0133] exist Figure 10 In this embodiment, 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 because the first BSS BSS1 and the second BSS BSS2 use the same BSS color. The first station STA1 receives frames (intra-BSS frames) from the second station STA2. The first station STA1 sets the intra-BSS NAV based on the frames sent from the second station STA2. Additionally, the first station STA1 receives frames (inter-BSS frames) from the third station STA3. However, because the first BSS BSS1 and the second BSS BSS2 have the same BSS color, the first station STA1 identifies the frames received from the third station STA3 as intra-BSS frames. Therefore, the first station STA1 sets the intra-BSS NAV based on the frames 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 CF-End frames from the second station STA2. Station STA1 resets the NAV within the BSS based on the CF-End frame received from station STA2. Thereafter, station STA1 can send frames even when attempting a transmission from station STA3. Therefore, transmissions from station STA1 may conflict with transmissions from station STA3.

[0134] You can refer to Figure 10 The described embodiments solve the problem Figure 10 The problems described in the embodiments. However, even when following the reference Figure 9 In the described embodiments, the operation of the wireless communication terminal receiving the CF-End frame may also be a problem. (Refer to...) Figure 11 This will be described.

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

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

[0137] Furthermore, when the NAV is set based on the BSS color value indicated by the signaling field of the PPDU, and the PPDU is not identified as either an intra-BSS PPDU or an inter-BSS PPDU, the wireless communication terminal can avoid resetting the NAV based on a CF-End frame sent from within the BSS. Additionally, when the NAV is set based on the BSS color value indicated by the signaling field of the PPDU, and the PPDU is not identified as either an intra-BSS PPDU or an inter-BSS PPDU, the wireless communication terminal can avoid resetting the NAV based on a CF-End frame sent from a BSS corresponding to a set of multiple BSSIDs, which includes BSSIDs corresponding to the wireless communication terminal's BSS. Through this embodiment, the wireless communication terminal can prevent interference with transmissions in the OBSS caused by BSS color conflicts. Moreover, as described above, the BSS color signaled by the PPDU can be the BSS color signaled by the PPDU's BSS color field. Specifically, the BSS color signaled by the PPDU can be the BSS color signaled by the PPDU's HE-SIG-A BSS color field.

[0138] As mentioned above, situations where 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 may include situations where the wireless communication terminal identifies BSS color conflicts. (See reference...) Figure 12 The method for determining whether a wireless communication terminal conflicts with BSS color schemes is described in detail.

[0139] Figure 12 This illustrates the operation of a wireless communication terminal identifying BSS color conflicts according to an embodiment of the present invention.

[0140] Wireless communication terminals can determine BSS color conflicts based on the MAC header. Specifically, the wireless communication terminal can determine BSS color conflicts based on the address field of the MAC header. In a specific embodiment, if there are two or more MAC address fields in the MAC header, at least one of these MAC address fields corresponds to a BSSID within the BSS, or at least one of these MAC address fields corresponds to a set of multiple BSSIDs including the BSSID within the BSS, then the wireless communication terminal can determine the corresponding PPDU as a PPDU within the BSS. This is because, in the case of BSS color, conflicts 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, a wireless communication terminal can determine that the destination of the MAC frame included in the PPDU is not the wireless communication terminal based on at least one of the signaling fields and PPDU format, and can therefore not decode the MAC header. Specifically, when a non-AP wireless communication terminal receives an HE single-user (SU) PPDU, and 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 can continue decoding. In this case, the non-AP wireless communication terminal can determine that the corresponding PPDU is a SU PPDU through L-SIG signaling. Additionally, the non-AP wireless communication terminal can determine that the corresponding PPDU is an extended-range SU PPDU based on L-SIG signaling and the HE-SIG-A modulation method. Furthermore, the non-AP wireless communication terminal can determine whether the corresponding PPDU is a PPDU used for downlink transmission based on the DL / UL fields of the HE-SIG-A field.

[0142] However, when the PPDU received by a 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 a 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 PPDU's signaling field, the non-AP wireless communication terminal may not decode the MAC frame included in the corresponding PPDU. In this case, the signaling field of the PPDU can be HE-SIG-B. Furthermore, cases where the Wireless Communication Terminal Identifier (STAID) field of the PPDU's signaling field does not include the identifier of the non-AP wireless communication terminal may include the following: the Wireless Communication Terminal Identifier (STAID) field of the PPDU's signaling field 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, a non-AP wireless communication terminal can 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, a non-AP wireless communication terminal can still decode the header of the MAC frame included in the PPDU. Specifically, situations where it is clear that the destination of the MAC frame included in the PPDU is not the wireless communication terminal can include the following: the corresponding PPDU is an 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. Furthermore, situations where it is clear that the destination of the MAC frame included in the PPDU is not the wireless communication terminal can include the following: as mentioned 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 a wireless communication terminal cannot identify whether a PPDU is an intra-BSS or inter-BSS 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 a PPDU sent from the corresponding BSS is an intra-BSS or inter-BSS PPDU, potentially causing a malfunction. Furthermore, if another wireless communication terminal cannot identify whether a PPDU sent by the wireless communication terminal is an intra-BSS or inter-BSS PPDU, the PPDU sent by the wireless communication terminal may cause other wireless communication terminals to malfunction. To prevent this malfunction, the wireless communication terminal can operate as described in the following embodiment.

[0145] Specifically, a wireless communication terminal can transmit a PPDU by including signaling information indicating that BSS color-based operations are not permitted in the signaling field of the PPDU. In this case, the wireless communication terminal receiving the PPDU including the signaling information indicating that BSS color-based operations are not permitted can choose not to perform the BSS color-based operation. In a specific embodiment, the wireless communication terminal can transmit the PPDU by setting the BSS color value indicated by the signaling field of the PPDU to a predetermined value. This predetermined value can be a reserved value that is not used in the BSS color selection process when the BSS color is chosen by the AP. For example, the predetermined value can be zero.

[0146] Furthermore, when a wireless communication terminal receives a signaling message indicating that operation based on BSS color is not permitted, the wireless communication terminal may not perform the operation based on the BSS color value. Specifically, when the BSS color value indicated by the signaling field of the PPDU received by the wireless communication terminal is a predetermined value, the wireless communication terminal may not perform the aforementioned SR operation based on the BSS color value. Additionally, the wireless communication terminal can transmit a PPDU by including the signaling message indicating that operation based on BSS color is not permitted in the signaling field of the PPDU using a conventional PPDU. Specifically, the wireless communication terminal may even transmit the signaling message indicating that operation based on BSS color is not permitted by using the BW signaling method of the MAC address or by using reserved bits in the MAC header.

[0147] Furthermore, when a wireless communication terminal receives a PPDU indicating a predetermined value in the BSS color, the wireless communication terminal may not perform operations 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 the 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 treat 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] Furthermore, a wireless communication terminal that receives a signaling message indicating that operation based on BSS color is not permitted can access the channel without using SR operation. Specifically, a wireless communication terminal that receives a signaling message indicating that operation based on BSS color is not permitted can access the channel without using the BSS color value.

[0149] Even if a non-AP wireless communication terminal arbitrarily selects a BSS color without receiving the signaling signal for BSS color, this can still cause a wireless communication terminal operating on BSS color to malfunction. A method is needed to prevent this.

[0150] The AP operating the BSS can select the BSS color corresponding to that BSS. Non-AP wireless communication terminals can obtain the assigned BSS color from the BSS color field included in the HE operation element received from the AP. Specifically, a non-AP wireless communication terminal can receive a management frame from the AP associated with it, and obtain the assigned BSS color from the BSS color field included in the HE operation element of the received management frame. In this case, the management frame can be any one of a beacon frame, association request frame, association response frame, re-association request frame, re-association response frame, probe request frame, and probe response frame.

[0151] When a non-AP wireless communication terminal fails to receive information indicating the BSS color, it can use a predetermined value as the BSS color value when communicating with another wireless communication terminal. This predetermined value can be a reserved value that is not used in the BSS color selection process when the BSS color is chosen by the AP. For example, the predetermined value can be zero. Specifically, if the non-AP wireless communication terminal does not receive information indicating the BSS color, it can set the BSS color value indicated by the PPDU sent by the non-AP wireless communication terminal to the predetermined value. Alternatively, when the non-AP wireless communication terminal fails to receive information indicating the BSS color, it can set the BSS color value indicated by the frame sent by the non-AP wireless communication terminal to the predetermined value. The non-AP wireless communication terminal does not receive information indicating the BSS color because there is no BSS color. Specifically, when the non-AP wireless communication terminal does not receive information indicating the BSS color, it can choose not to associate with any AP. Furthermore, situations where a non-AP wireless communication terminal does not receive signaling notification of BSS color can include cases where the non-AP wireless communication terminal can establish a Tunnel Direct Link Setup (TDLS) link, a Direct Link Setup (DLS) link, or IBSS (Independent) membership. Additionally, situations where a non-AP wireless communication terminal does not receive signaling notification of BSS color can include the following: after receiving signaling information from the AP indicating that operation based on the BSS color value is not permitted, the non-AP wireless communication terminal does not receive information regarding the changed BSS color value.

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

[0153] In another specific embodiment, when a PPDU is sent to a wireless communication terminal between BSSs, the wireless communication terminal can set the BSS color value indicated by the PPDU to a predetermined value. It is highly likely that the wireless communication terminal is unaware of the BSS colors between BSSs. Furthermore, this is because the wireless communication terminal between BSSs can ignore PPDUs indicating the BSS colors of the BSS including the wireless communication terminal.

[0154] Furthermore, when a 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 a wireless communication terminal receives a PPDU indicating a predetermined value as the BSS color, the wireless communication terminal may not perform the 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 treat 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.

[0155] Non-traditional PPDUs include signaling fields indicating BSS colors, such as the HE-SIG-A field, and wireless communication terminals can perform the various SR operations described above based on these signaling fields. However, traditional PPDUs do not include signaling fields indicating BSS colors. Therefore, wireless communication terminals receiving traditional PPDUs must perform SR operations based on the MAC frames included in the PPDU. However, there are MAC frames that only include the receiver address RA and not the sender address TA. SR operations for MAC frames that only include the receiver address may be problematic when BSS color-based operations can be omitted because a MAC frame containing only the receiver address is sent via a traditional PPDU or a BSS color conflict occurs. (See reference...) Figure 13 and Figure 14 An embodiment of a wireless communication terminal associated with it is described.

[0156] Figure 13The MAC frame format that allows transmission (CTS) frames and ACK frames according to an embodiment of the present invention is shown. Figure 14 The operation of setting NAV based on RTS frames and CTS frames is illustrated in an embodiment of the present invention.

[0157] The MAC frames of CTS and ACK frames may include a frame control field containing information about frame control. Additionally, the MAC frames of CTS and ACK frames may include a duration field for NAV setting. Furthermore, the MAC frames of CTS and ACK frames may include an RA field indicating the receiver's address. Additionally, the MAC frames of CTS and ACK frames may include a field indicating whether the MAC frame includes an incorrect FCS.

[0158] The RA field of a CTS frame can be set based on the TA field of the RTS frame. Specifically, the value of the RA field in the CTS frame and the TA field in the RTS frame can be a value with the individual / group bits set to zero. Additionally, when the CTS frame is the first frame in the transmission sequence, the RA field can be set to the sender's MAC address.

[0159] The RA field of an ACK frame can be set based on the Address2 field of a data frame, management frame, BlockACKReq frame, BlockACK frame, or PS polling frame sent to a wireless communication terminal. Specifically, the RA field of an ACK frame can be set to a non-bandwidth signaling TA value. Alternatively, the RA field of an ACK frame can be set to the receiver's MAC address.

[0160] When a wireless communication terminal may be unsure whether a frame is an intra-BSS frame or an inter-BSS frame based on the address field of a CTS or ACK frame, the wireless communication terminal can set a basic NAV based on the corresponding frame. Specifically, when a wireless communication terminal may be unsure whether a frame is an intra-BSS frame or an inter-BSS frame based on a PPDU including a CTS or ACK frame, and the address field of the CTS or ACK frame may also be unsure, the wireless communication terminal can set a basic NAV based on the frame. Additionally, the situation where a wireless communication terminal may be unsure whether a frame is an intra-BSS frame or an inter-BSS frame based on the address field of a CTS or ACK frame can be as follows: the address field of the CTS or ACK frame is one, and the corresponding address field does not indicate an AP address or BSSID. In a specific embodiment, a non-AP wireless communication terminal can receive downlink (DL) CTS frames. In this case, the address field of the corresponding CTS frame may include the address of the non-AP wireless communication terminal and may not include the address or BSSID of the wireless communication terminal acting as an AP. Therefore, the wireless communication terminal receiving the corresponding CTS frame may be unsure whether the corresponding CTS frame is an inter-BSS frame or an intra-BSS frame based on the address field of the corresponding CTS frame. Additionally, when a wireless communication terminal may be unsure whether a frame is an intra-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 conventional PPDU. This is because a conventional PPDU may not include information indicating the BSS color. Furthermore, a situation where a wireless communication terminal may be unable to determine whether a frame is an intra-BSS frame or an inter-BSS frame based on a PPDU including a CTS frame or an ACK frame may occur as follows: the wireless communication terminal may be unable to determine whether a frame is an intra-BSS frame or an inter-BSS frame based on the BSS color indicated by the signaling field of the corresponding PPDU, as in the embodiments described above.

[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 frame's address field. For example, when receiving a downlink (DL) CTS frame or an uplink (UL) CTS frame, the wireless communication terminal can set the basic NAV based on that frame.

[0162] Furthermore, when a wireless communication terminal maintains a NAV, instead of setting a basic NAV based on the corresponding frame in the above embodiments, the wireless communication terminal can assume that the NAV set through the corresponding frame is not set through a BSS intra-frame. Specifically, when the wireless communication terminal may not be able to determine whether a frame is an intra-BSS frame or an inter-BSS frame based on the address field of a CTS frame or ACK frame, the wireless communication terminal can assume that the NAV set on the frame is not set through a BSS intra-frame. Moreover, when the wireless communication terminal receives a frame, it can assume that the NAV set based on that frame is not set through a BSS intra-frame, regardless of the value of the frame's address field.

[0163] exist Figure 14 In this embodiment, all stations from STA1 to STA3 are included in the same BSS. STA1 sends an RTS frame, and STA2 responds to the RTS frame by sending a CTS frame. STA3 sets the NAV within the BSS based on the RTS frame. Because the address field of the CTS frame sent by STA2 only includes the address of STA1, STA3 may not be able to clearly determine whether the CTS frame sent by STA2 was sent from within the BSS. Therefore, STA3 sets the basic NAV based on the CTS frame sent by STA2, as in some of the embodiments described above.

[0164] At this point, 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 identifies the received CF-End frame as an intra-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 intra-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 between BSSs while only receiving CTS frames, 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 address this issue, the wireless communication terminal can send a PPDU (Private Component Disclosure Unit) in the format of a PPDU that signals the BSS color, containing only an address field. However, when sending a PPDU that signals the BSS color, conventional wireless communication terminals may not decode the PPDU. Furthermore, the wireless communication terminal can infer the BSS of the CTS and ACK frames based on frames sent before the CTS or ACK frames. This raises the issue of potentially requiring the wireless communication terminal to receive previously sent frames and store information about the received frames. Therefore, the wireless communication terminal can send information identifying the BSS using a conventional PPDU. (See reference...) Figures 15 to 17 This will be described.

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

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

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

[0169] Additionally, the information identifying the BSS can be any of the following: BSS color, BSSID, and a portion of the BSS color. Furthermore, the information identifying the BSS can be a portion of the AID generated based on the BSS color. Additionally, the information identifying the BSS can be a part of the BSSID or information generated based on the BSSID. In this case, the information generated based on the BSSID can be a value obtained by calculating a partial value of the BSSID or a value obtained by calculating the BSSID itself.

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

[0171] In addition, wireless communication terminals can send information identifying the BSS by combining multiple reserved fields.

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

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

[0174] For reference Figure 15 As described, a wireless communication terminal can use reserved bits in the service field to transmit information identifying the BSS. Specifically, the wireless communication terminal can use bits 8 (B7) to 13 (B12) of the service field to transmit information identifying the BSS. Because in the reference... Figures 15 to 16 The described embodiments use reserved bits, so conventional wireless communication terminals that do not support embodiments of the present invention cannot decode the information identifying the BSS, but can successfully receive the PPDU according to embodiments of the present invention.

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

[0176] Figure 17 This illustrates a wireless communication terminal according to an embodiment of the present invention. Figures 15 to 16 The implementation example sets up the operation of NAV.

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

[0178] Therefore, even when the address field of the MAC frame is set to 1, the third station STA3 can correctly set the NAV within the BSS and the basic NAV. Subsequently, when the third station STA3 receives a CF-End frame from within the BSS, it can reset the NAV within the BSS. Furthermore, when the third station STA3 receives a CF-End frame from between BSSs, it does not need to reset the NAV within the BSS.

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

[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 a PPDU sent to the AP may indicate the AP's BSSID. Additionally, the partial AID field of a 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. Furthermore, when a 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's address. In a specific embodiment, the partial AID field may be a 9-bit field.

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

[0182] Wireless communication terminals can transmit information identifying the BSS using a portion of the AID and Group ID fields from the VHT-SIG-A. Specifically, a wireless communication terminal acting as an AP can set a portion of the AID field value to a 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 bitwise XOR operation, mod X represents the remainder after division 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.

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

[0186] Additionally, 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 PPDUs 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 part of the AID field of the PPDU according to the formula above. In this case, the wireless communication terminal can set the group ID field to 63.

[0187] Figures 19 to 20 This invention illustrates a method for determining whether a frame received by a wireless communication terminal is an inter-BSS frame or an intra-BSS frame.

[0188] Figure 19 This invention illustrates a method for determining whether a PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on whether the PPDU received by the wireless communication terminal is a downlink PPDU, according to an embodiment of the invention.

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

[0190] The wireless communication terminal can 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 can 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 can identify whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on information other than the BSS color value indicated by the signaling field of the PPDU. Specifically, when the frame received by the wireless communication terminal is a downlink frame, the wireless communication terminal can identify the frame as an inter-BSS frame. In a specific embodiment, even if the BSS color value indicated by the BSS color field of the signaling field of the PPDU or the BSS color indicated by a portion of the 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 can identify the frame as an inter-BSS frame. For example, in Figure 19 In one embodiment, the AP receives a PPDU for downlink transmission and identifies the PPDU as an inter-BSS frame.

[0191] Furthermore, when the value of the group ID field in the VHT-SIG-A field of a PPDU received by the wireless communication terminal is 63, the wireless communication terminal can identify the received PPDU as an inter-BSS PPDU. This is because, as referenced... Figure 18 As described, the group ID field of PPDUs sent to non-AP wireless communication terminals is set to 63. In this case, the wireless communication terminal acting as an AP can only identify the received PPDU as an inter-BSS PPDU when the DLS or TDLS protocol is not used. This is because, as mentioned above, the group ID field value is also set to 63 even when a DLS or TDLS wireless communication terminal sends a PPDU to another DLS or TDLS wireless communication terminal via a direct path.

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

[0193] Furthermore, when a wireless communication terminal acting as an access point (AP) receives a VHT MU PPDU, it can identify the PPDU as an inter-PPDU. This is because VHT MU PPDUs can be used solely for downlink transmission. Specifically, the wireless communication terminal acting as an AP can determine whether the corresponding PPDU is a VHT MU PPDU by automatic detection and the VHT-SIG-A field. Additionally, if the group ID of VHT-SIG-A is not 0 or 63, the wireless communication terminal acting as an AP can identify the corresponding PPDU as a MU PPDU.

[0194] Additionally, when a wireless communication terminal acting as an access point (AP) receives an HE PPDU and the UL / DL field of the HE-SIG-A field indicates downlink transmission, the AP can identify the corresponding PPDU as an inter-BSS PPDU. In this case, the value of the UL / DL field can be zero. Only when the DLS or TDLS protocol is not used can the AP identify the received PPDU as an inter-BSS PPDU.

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

[0196] When a wireless communication terminal acting as an access point (AP) receives a trigger-based PPDU from a previously untriggered wireless communication terminal, the AP can 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 sending a trigger frame, the AP can identify the PPDU as an inter-BSS PPDU.

[0197] Figure 20 This invention illustrates 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.

[0198] As described above, when a wireless communication terminal acting as an AP receives a PPDU for downlink transmission, it can identify the PPDU as an inter-BSS PPDU. This is because the PPDU destined for the wireless communication terminal acting as an AP within the BSS is a PPDU for uplink transmission. Furthermore, the AP can identify whether a 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 a PPDU is for downlink transmission based on whether the PPDU includes a trigger frame. Thus, the wireless communication terminal can identify whether a PPDU is an inter-BSS PPDU based on the SR-related information.

[0199] In this case, 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 sent, and can indicate the conditions under which it is allowed. In this case, the signaling field can be the HE-SIG-A field. Specifically, the SR field can indicate SR_Delay, which indicates that the SR operation will be delayed. If the PPDU is an HE SU PPDU or an HE extended range SU PPDU, and the corresponding PPDU includes a trigger frame, then the SR field indicates SR_Delay.

[0200] Furthermore, the SR field can indicate SR_Restricted, which indicates that SR operation is restricted. Specifically, when the SR field of a PPDU has an SR_Restricted value, the duration of the TXOP transmitted by the inter-BSS wireless communication terminal during SR operation can be limited to the PPDU including the trigger frame. Additionally, when the PPDU is an HE MU PPDU and the corresponding PPDU includes a trigger frame, the SR field indicates SR_Restricted.

[0201] Additionally, the SR field can indicate SR_Disallowed, which means that SR operation is not allowed. A wireless communication terminal sending a PPDU including a trigger frame uses the SR field of the PPDU to indicate that the PPDU includes a trigger frame and that the transmission sequence can be protected based on that trigger frame.

[0202] Therefore, when the SR field value of a PPDU received by a wireless communication terminal acting as an AP is SR_Restricted or SR_Delay, the AP can identify the PPDU as an inter-BSS PPDU based on the PPDU type and the SR field. Specifically, when the PPDU received by the AP is a HE single-user (SU) PPDU or an HE extended-range SU PPDU, and the SR field indicating the signal is SR_Restricted, the AP can identify the PPDU as an inter-BSS PPDU. Additionally, when the PPDU received by the AP is an HE MU PPDU and the SR field indicating the signal is SR_Delayed, the AP can identify the PPDU as an inter-BSS PPDU. In this case, a HE SU PPDU indicates a PPDU intended for transmission to a single wireless communication terminal. Similarly, an HE extended-range SU PPDU indicates a PPDU intended for transmission to a single wireless communication terminal. Finally, an HE MU PPDU indicates a PPDU intended for multiple wireless communication terminals.

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

[0204] exist Figure 20 In this embodiment, the first AP AP1 sends a trigger frame to trigger transmissions at the first station STA1 and the second station STA2. At this time, the second AP AP2 receives a PPDU including the trigger frame sent by the first AP AP1. The second AP AP2 can identify that the corresponding PPDU includes the trigger frame by 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. Specifically, 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 21A method is shown for a wireless communication terminal to determine whether a PPDU is an inter-BSS PPDU or an intra-BSS PPDU when a PPDU received by the wireless communication terminal according to an embodiment of the present invention satisfies both inter-BSS PPDU conditions and intra-BSS PPDU conditions.

[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 can 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 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 can 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: the wireless communication terminal cannot decode the MAC header of the corresponding frame.

[0207] Furthermore, in the above embodiments, the inter-BSS frame conditions and intra-BSS frame conditions can include all conditions for identifying whether a wireless communication terminal is using an inter-BSS frame or an intra-BSS frame. For example, the wireless communication terminal can 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 mentioned 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 PPDU's HE-SIG-A.

[0208] Additionally, the wireless communication terminal can identify whether a frame is an inter-BSS frame or an intra-BSS frame based on the value of a portion of the AID field in the signaling field of the PPDU (Package Component Distributed Unit) containing the frame. Furthermore, the wireless communication terminal can identify whether a frame is an inter-BSS frame or an intra-BSS frame based on the frame's address field. Moreover, when the wireless communication terminal is an access point (AP) and receives a downlink transmission PPDU, the wireless communication terminal can identify the frame included in the corresponding PPDU as an inter-BSS frame.

[0209] If a PPDU includes a BSS color field, then a portion of the AID field is unlikely to include information about the BSS color. Therefore, situations where both the intra-BSS frame condition and the inter-BSS color condition are satisfied can include the following: when the wireless communication terminal performs a determination based on the BSS color field or a portion of the AID field, the corresponding PPDU is identified as an intra-BSS PPDU; when the wireless communication terminal performs a determination based on the frame's address field, the corresponding PPDU can be identified as an inter-BSS PPDU. Alternatively, when the wireless communication terminal performs a determination based on the BSS color field or a portion of the AID field, the corresponding MAC frame is identified as an intra-BSS frame; when the wireless communication terminal performs a determination based on whether the PPDU including the MAC frame is an uplink transmission format, the corresponding PPDU is identified as an inter-BSS PPDU. Because the number of bits representing the BSS color is finite, BSS color conflicts can occur as described above. Therefore, when a frame received by the wireless communication terminal satisfies both the inter-BSS frame condition and the intra-BSS frame condition, the wireless communication terminal can identify whether the received frame is an inter-BSS frame or an intra-BSS frame based on conditions other than the BSS color indicated by the PPDU. Specifically, 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 can identify whether the received frame is an inter-BSS frame or an intra-BSS frame based on conditions other than the BSS color field or part of the AID field in the PPDU. In this case, other conditions can be identified based on the address field of the MAC header mentioned above. Another condition could be that the PPDU including the frame is a PPDU used for downlink transmission.

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

[0211] The wireless communication terminal can identify a received frame as an intra-BSS frame based on any condition, and then identify the received frame as an inter-BSS frame according to the aforementioned priority order. In this case, the wireless communication terminal can use an enhanced CCA level. Specifically, the wireless communication terminal can use the 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 mentioned above, a wireless communication terminal can enter a power-saving state based on the MAC header. Now, let's refer to... Figures 22 to 23 Describe in detail the specific operation of the wireless communication terminal.

[0213] Figure 22 This illustrates a scenario 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. Additionally, Figure 23 This illustrates a situation where, when a wireless communication terminal according to an embodiment of the present invention is included in a BSS corresponding to a set of multiple BSSIDs, the wireless communication terminal enters a power-saving state based on the MAC header of a frame received by the wireless communication terminal.

[0214] When the sender address TA or receiver address RA indicated by the MAC header of a received frame corresponds to another BSSID in a set of multiple BSSIDs, where the set of multiple BSSIDs includes the BSSID of a BSS, and the BSS includes the wireless communication terminal, the wireless communication terminal can determine that the received frame is an intra-BSS frame. When the frame received by the wireless communication terminal is an intra-BSS frame and the wireless communication terminal is not the receiver of the received frame, the wireless communication terminal can enter a power-saving state. In this state, the wireless communication terminal can maintain the power-saving state until the duration of the PPDU including the received frame ends.

[0215] exist Figure 22 In this 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 a BSS intraframe. If the received PPDU is a BSS intraframe, the second station STA2 determines whether the recipient of the received PPDU is the second station STA2. Specifically, the second station STA2 can determine whether the recipient of the PPDU received based on the MAC header is the second station STA2. At this time, if the second station STA2 is not the recipient of the received PPDU, the second station STA2 can enter a power-saving state.

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

[0217] In specific embodiments, even if the receiver address RA of the trigger frame or the receiver address RA of the multi-station block ACK (multi-STA Block ACK) frame does not match the MAC address of the wireless communication terminal, the wireless communication terminal may still be required to receive the trigger frame or the multi-station block ACK frame. Specifically, when the receivers of the trigger frame are multiple wireless communication terminals, the receiver address RA of the trigger frame can be a broadcast address. In this case, the number of user information fields in the trigger frame can be two or more. Additionally, when the receivers of the multi-station block ACK frame are multiple wireless communication terminals, the receiver address RA of the multi-station block ACK can be a broadcast address. In this case, the number of AID fields in the per STA information subfield of the multi-station block ACK can be two or more. In this case, the broadcast address can indicate multiple wireless communication terminals or one wireless communication terminal.

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

[0219] Specifically, when the receivers of a trigger frame or a multi-site block ACK frame are multiple wireless communication terminals, the receiver address RA can be a multicast address or a group address. Therefore, when a wireless communication terminal receives a trigger frame or a multi-site block ACK frame and the receiver address RA of the received frame does not include the multicast address or group address of the wireless communication terminal, the wireless communication terminal can enter a power-saving state.

[0220] When any of the BSSIDs included in a multi-BSSID set is set to the receiver address RA or the sender address TA of a frame, the wireless communication terminal included only in the BSS identified by the corresponding BSSID can be either the receiver or the sender of the corresponding frame. Specifically, for frames 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 sender address of the frame based on the BSSID. In this case, the wireless communication terminal does not need to separately determine whether the receiver address RA and the sender address TA are broadcast addresses or multicast addresses of the address including the wireless communication terminal. For ease 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 sender address TA of the frame received by the wireless communication terminal matches the second BSSID, the wireless communication terminal can enter a power-saving state.

[0221] exist Figure 23 In this embodiment, the multiple BSSID set includes a first BSSID BSSID (1) and a second BSSID BSSID (2). A first station STA1 is included in the BSS identified by the second BSSID BSSID (2), and a 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 a BSS intraframe. Specifically, the second station STA2 can determine whether the MAC address signaled by the MAC header of the received PPDU is a BSSID from the multiple BSSID set including the first BSSID. Because the sender address TA of the received PPDU is the second BSSID BSSID (2), the second station STA2 determines the received PPDU as a BSS intraframe. 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 a power-saving state.

[0222] When the received PPDU is an inter-BSS frame, the second station STA2 determines whether it is the receiver of the received PPDU. Specifically, the second station STA2 can determine whether it is the receiver of the received PPDU based on the MAC header. If the second station STA2 is not the receiver of the received PPDU, it can enter a power-saving state.

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

[0224] As mentioned above, wireless communication terminals can send signals to notify various information through the signaling fields of the PPDU. (Refer to...) Figure 24 Describe the format of the signaling field.

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

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

[0227] Specifically, the user-specific fields include information about the Station Identifier (STAID), the number of spatial streams, Transmit Beamforming (TxBF), Modulation and Coding Scheme (MCS), Dual Subcarrier Modulation (DCM), and coding. Furthermore, when multiple wireless communication terminals are assigned to a single RU, the user-specific fields may include information about the spatial configuration field, MCS, DCM, and coding. In this case, the coding information may indicate whether LDPC is used. The common fields may include a Binary Block Code (BCC) block. User-specific fields within a BCC block include information about two wireless communication terminals. In this case, the final BCC block may include information about one wireless communication terminal. Additionally, information about individual wireless communication terminals may be referred to as per-user content. A BCC block may include CRC and tail bits. Furthermore, the HE-SIG-B field may also include padding to align with OFDM symbol boundaries. The specific format of the HE-SIG-B field may be as follows: Figure 24 As shown in (a).

[0228] When a wireless communication terminal transmits a PPDU over a frequency bandwidth of 40MHz or higher, it can repeatedly transmit two HE-SIG-B fields, each with a 20MHz frequency bandwidth, across the entire 40MHz band. In this case, the two HE-SIG-B fields can include different information. Furthermore, each of the two HE-SIG-B fields can include information about the RUs included in the frequency bandwidth used to transmit the corresponding HE-SIG-B field. The wireless communication terminal receiving the PPDU can identify the configuration of the entire MU PPDU by decoding the two HE-SIG-B fields. Specifically, the wireless communication terminal can... Figure 24 Send the HE-SIG-B field in the form shown in (b).

[0229] In a specific embodiment, the wireless communication terminal can indicate the wireless communication terminal corresponding to each user content through the wireless communication terminal identifier in the user-specific field of the HE-SIG-B field. In this case, the wireless communication terminal identifier can be an associated identifier (AID). If a multiple BSSID set is used, the wireless communication terminal uses the assigned AID according to the group addressing AID allocation method in the multiple BSSID TIM operation, enabling the broadcast of PPDUs to wireless communication terminals included in any 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 its AID. In this case, the wireless communication terminal can broadcast the PPDU to the wireless communication terminal in the BSS corresponding to AID 0 by specifying the wireless communication terminal identifier as 0 in the user-specific field of each user content. When using a multiple BSSID set, the wireless communication terminal can use a specific AID to broadcast the PPDU to wireless communication terminals included in all BSSs corresponding to the multiple BSSID set. In this case, the specific AID can be an unassigned value in the multiple BSSID TIM operation. In a specific embodiment, the specific AID can be 2047.

[0230] Frames to be sent to multiple wireless communication terminals and frames to be sent to any one wireless communication terminal can be included in a single MU PPDU. In this case, 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 a wireless communication terminal receives the MU PPDU, it 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. In this case, the wireless communication terminal can determine whether the wireless communication terminal identifier indicates a wireless communication terminal based on the range of wireless communication terminals indicated by the wireless communication terminal identifier. Specifically, a wireless communication terminal can be identified based on 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 those indicating the first group to those indicating the Nth group. Here, 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 based on the wireless communication terminal identifier indicating the (N)th group.

[0231] When using multiple BSSID sets, the 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, but the wireless communication terminal identifier indicating a broadcast 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. If only the wireless communication terminal identifier indicating the wireless communication terminal is not included in the per-user content, the wireless communication terminal identifier indicating a broadcast to the BSS associated with the wireless communication terminal is not included in the per-user content, and the wireless communication terminal identifier indicating a broadcast to a wireless communication terminal included in all BSSs can be included in the per-user content, then the wireless communication terminal can receive the payload of the PPDU transmitted via the RU indicated by the per-user content, which includes the wireless communication terminal identifier indicating a broadcast to a wireless communication terminal included in all BSSs. If none of the above conditions are met, the wireless communication terminal may 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 ease of explanation, the wireless communication terminal identifier is described in three ranges, but depending on the number or inclusion relationship of the wireless communication terminals, there may be more range types. In this case, as mentioned above, the wireless communication terminal can determine the wireless communication terminal identifier based on the size of the range indicated by the wireless communication terminal identifier.

[0232] When multiple BSSID sets are not used, the wireless communication terminal can identify 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, but a wireless communication identifier indicating at least one of broadcast, multicast, and multicast of a 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. When only the wireless communication terminal identifier indicating the wireless communication terminal is not included in the per-user content, a wireless communication identifier indicating at least one of broadcast, multicast, and multicast of a group including the wireless communication terminal is not included in the per-user content, and a wireless communication terminal identifier indicating a broadcast destined for a wireless communication terminal included in the BSS can be included in the per-user content. In this case, the wireless communication terminal can receive the payload of the PPDU transmitted via the RU indicated by the per-user content, which includes the wireless communication terminal identifier indicating a broadcast destined for a wireless communication terminal included in the BSS. If none of the above conditions are met, the wireless communication terminal may 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 ease of explanation, the wireless communication terminal identifier is described in three ranges, but depending on the number or inclusion relationship of the wireless communication terminals, there may be more range types. In this case, as mentioned above, the wireless communication terminal can determine the wireless communication terminal identifier based on the size of the range indicated by the wireless communication terminal identifier.

[0233] To enable the receiving wireless communication terminal to effectively control the MAC frame, the terminal can send information about MAC frame control via the MAC frame header. Therefore, a method for efficiently sending this control information is needed. (See reference...) Figure 25 and Figure 33 This will be described.

[0234] Figure 25 This 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 about frame control. Additionally, the MAC frame may indicate the duration for NAV setting, depending on the frame type, or may include a duration / ID field indicating the AID of the wireless communication terminal sending the frame. Furthermore, the MAC frame may include four address fields indicating address-related information. Additionally, the MAC frame may include a sequence control field indicating information about sequence control. Furthermore, the MAC frame may include a QoS control field indicating information about Quality of Service (QoS) control. Furthermore, the MAC frame may include a frame body field indicating the payload of the MAC frame. Additionally, 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. Alternatively, the MAC frame may include the frame control field, duration / ID field, address field, and FCS field regardless of the frame type and subtype.

[0236] Figure 26 This is a view illustrating a variant of the HT control field according to an embodiment of the present invention.

[0237] Wireless communication terminals can send and modify various HT control fields. Specifically, wireless communication terminals can send HT control fields in HT variant, VHT variant, or HE variant format. Furthermore, the HT control field can be a 32-bit field. In this case, the first bit B0 and the second bit B1 of the HT control field can indicate the type of the HT control field. When the first bit B0 of the HT control field is 0, the HT control field can be an HT variant. For example... Figure 26 The bits below the second bit B1 of the HT control field shown can include HT control intermediates, AC constraints, and RDG / more PPDU subfields. Additionally, when the first bit B0 of the HT control field is 1 and the second bit B1 is 0, the HT control field can be a VHT variant. In this case, as... Figure 26 The bits below the second bit B1 of the HT control field shown can include VHT control intermediates, AC constraints, and RDG / more PPDU subfields. When the first distinct bit B0 of the HT control field is 1 and the second bit B1 is 1, the HT control field can be an HE variant. In this case, as shown... Figure 26 The bits below the second bit B1 of the HT control field shown may include the Aggregate Control (A-Control) subfield. The A-Control subfield may include control information. (See reference...) Figures 27 to 33 Describes the control information included in A-Control and the format of A-Control subfields.

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

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

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

[0241] The control subfield may include information relating to at least one of UL MU response scheduling, receive operation mode indication, HE link adaptation, UL PPDU triggering, BlockACK request, and buffer status report request. When decoding bits corresponding to the length of the A-Control subfield, the wireless communication terminal decoding the control subfield can determine that there is no additional control information to decode. However, when the number of control subfields included in the A-Control subfield is variable and the length of the A-Control subfield remains constant, the wireless communication terminal decoding the A-Control subfield may be unsure whether the currently decoded bit is a padding bit or a control subfield. Therefore, a method is needed for the wireless communication terminal decoding the A-Control subfield to determine whether the currently decoded bit is a padding bit.

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

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

[0244] Figure 28 The format of the A-Control subfield of the control subfield according to another embodiment of the present invention is shown.

[0245] The control subfields 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. Alternatively, the information indicating whether the corresponding control field is the last control subfield included in the A-Control subfield may be referred to as a control end field. In this embodiment, the wireless communication terminal decoding the A-Control subfield may stop decoding the A-Control subfield based on the control end field. Specifically, when the control end field indicates that the corresponding control subfield is the last control subfield of the A-Control subfield, the wireless communication terminal decoding the A-Control subfield can determine that there is no additional control information to be decoded after the corresponding control subfield. Specifically, the format of the control subfield may be as follows: Figure 28 As shown in the image.

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

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

[0248] Specifically, a wireless communication terminal can insert multiple HE variants into the HT control field to transmit the HT control field. At this time, the wireless communication terminal can insert a field indicating the presence of more HE variants to be decoded within the HE variants. This field indicating the presence of more HE variants can be called a More A-Control subfield. For example, when the value of the More A-Control subfield is 1, the wireless communication terminal decoding the HT control field can decode the subsequent bits into HE variants after the corresponding HE variants. The More A-Control subfield can be placed in the last bit of the HE variant. Alternatively, the More A-Control subfield can be placed in the first bit of the A-Control subfield. Furthermore, the More A-Control subfield can be placed immediately after the two bits indicating the variants included in the A-Control subfield. Additionally, the More A-Control subfield can be placed before extended HE variants.

[0249] In a specific embodiment, the length of the A-Control subfield can be extended in 32-bit units. Furthermore, even if the A-Control subfield is extended, the first bit B0 and the second bit B1 of the A-Control subfield, which are variants included in the HT control field, may not be repeatedly indicated. Additionally, 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 can be as follows... Figure 29 As shown in the image.

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

[0251] When the HE control subfield is an HE variant, the wireless communication terminal can insert a specific control ID value indicating the end of the HE variant. In this case, the wireless communication terminal decoding the HE control subfield can 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 HE control subfield can be as follows: Figure 30 As shown in the image.

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

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

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

[0255] When the length of the HE variant transmitted by the wireless communication terminal is variable, the wireless communication terminal can 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 can indicate -1, which is the number of control subfields immediately following the length subfield. In this case, the length subfield can have the same number of bits as the control ID. In another specific embodiment, the length subfield can indicate the number of unit lengths by which the A-Control subfield is extended. For example, when the A-Control subfield is extended in bytes, the length subfield can indicate the total number of bytes of the A-Control subfield or the number of bytes by which the A-Control subfield is extended. In another specific embodiment, when the A-Control subfield is extended in 32-bit or 30-bit units, the length subfield can indicate the value obtained by dividing the length of the extended A-Control subfield by 32 bits or 30 bits, or it can indicate the value obtained by dividing the total length of the A-Control subfield by 32 bits or 30 bits.

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

[0257] A wireless communication terminal can transmit control information through the frame body. Specifically, the wireless communication terminal can transmit control information included in the A-Control field through the frame body. The total length of the MAC header or the length of the HT control field can be limited, and in this case, this is because there is control information required by the wireless communication terminal to receive the frame but not included in the HT control. In a specific embodiment, the wireless communication terminal transmits the control ID field through the HT control field and transmits the control information field corresponding to the control ID field through the frame body. Specifically, the wireless communication terminal transmits the control ID field corresponding to a specific value through the HT control field and transmits the control information field corresponding to the control ID field through the frame body. 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 the control ID field through the HT control field and transmits the control information field corresponding to the control ID field through the frame body. For example, when the length of the control information field is long, such as information about BlockAck or information about BlockAck requests, the wireless communication terminal can transmit the control information field through the frame body. At this point, when multiple control ID fields are sent via the HT control field and multiple control information fields corresponding to the multiple control ID fields are sent via the frame body, the wireless communication terminal can insert the control information fields corresponding to the control ID fields into the frame body according to the sorting order of the control ID fields. Figure 33 In this embodiment, the HT control field contains control ID m and control ID m+1, and the wireless communication terminal inserts them into the HT control field in the order of control ID m and control ID m+1. Because the control information corresponding to multiple control IDs is long, the wireless communication terminal inserts the control information corresponding to the control IDs 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 finite length, the wireless communication terminal transmits the control ID field through the HT control field and transmits the control information field corresponding to the control ID field through the frame body. Furthermore, the length of the HT control field can be fixed at 32 bits (4 bytes). Additionally, the wireless communication terminal can transmit information indicating that the control information field corresponding to the control ID field is included in the frame body. Furthermore, the wireless communication terminal can transmit information indicating that the control information field corresponding to the control ID field is included in the frame body. In another specific embodiment, the wireless communication terminal can transmit information indicating the end of a control subfield. In this case, the information indicating the end of the control subfield can be a 1-bit field. In this case, the wireless communication terminal can act as a reference... Figures 28 to 32 In the described embodiments, information indicating the end of the control subfield is sent.

[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 multiple wireless communication terminals can send a trigger frame to these multiple wireless communication terminals to initiate transmissions. Then, the multiple wireless communication terminals can send response frames to the terminal that sent the trigger frame, based on the trigger frame. Through this operation, multiple wireless communication terminals can simultaneously send frames to a single wireless communication terminal. (See reference...) Figures 34 to 44 Describes the trigger frame-based operation of a wireless communication terminal.

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

[0262] The trigger frame may include a frame control field indicating information about frame control. Additionally, the trigger frame may include a duration / ID field indicating the duration for which NAV settings are applied. Furthermore, the trigger frame may include an RA field indicating the receiver's address and a TA field indicating the sender's address. When the trigger frame triggers multiple wireless communication terminals, the RA field may indicate the multicast or broadcast addresses of the multiple wireless communication terminals. When the trigger frame triggers a single 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 contains an error.

[0263] In addition, the trigger frame may include a common information field and one or more per-user information fields. The common information field may indicate information typically applied to 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. The number of per-user information fields can then be determined based on the number of multiple wireless communication terminals triggered by the trigger frame. The trigger frame may include a padding field. This padding field allows the receiving wireless communication terminal time to process the trigger frame. The specific format of the trigger frame may be as follows: Figure 34 As shown in the image.

[0264] Figure 35 The format of the public information field and the per-user information field of the trigger frame according to an embodiment of the present invention is shown.

[0265] The common information field may include the length of the trigger-based PPDU or a length field indicating the length of the L-SIG field of the trigger-based PPDU. In this case, the length field may be a 12-bit field. Additionally, the common information field may include a concatenation indication field, indicating the existence of a subsequent trigger frame after the trigger frame. The common information field may include a CS required field, indicating whether channel sensing is required when transmitting the trigger-based PPDU. In this case, channel sensing may include virtual channel sensing and energy detection (ED) for determining whether NAV is set. Furthermore, the trigger frame may include an HE-SIG-A information field, indicating information to be inserted into the HE-SIG-A field of the trigger-based PPDU. In this case, information that the wireless communication terminal receiving the trigger frame can identify itself may be omitted from the trigger frame. Additionally, the trigger frame may include CP and LTF type fields, indicating the combination of LTF and cyclic prefix (CP) of the trigger-based PPDU. Furthermore, the trigger frame may include a trigger type field, indicating the type of trigger frame. At this point, the trigger frame type can indicate any of the following: basic trigger, beamforming report, polling trigger, MU-BAR, and MU-RTS. Furthermore, the trigger frame may include trigger-related common information fields whose format is determined by the trigger type. The specific form of the common information fields can be similar to... Figure 35 The form shown in (a) is the same.

[0266] The per-user information field may include a user identifier field, which 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, which indicates information about the RUs allocated to the wireless communication terminal corresponding to the user identifier field. Furthermore, the per-user information field may include a coding type field, which is used by the corresponding wireless communication terminal when transmitting a trigger-based PPDU. Specifically, the coding type field may indicate BCC or LDPC. Additionally, when the wireless communication terminal corresponding to the user identifier field transmits a trigger-based PPDU, the per-user information field may include a DCM field, which indicates whether the corresponding wireless communication terminal uses dual-carrier modulation (DCM). Furthermore, the per-user information field may include an SS allocation field, which indicates the spatial stream to be used by the wireless communication terminal when transmitting a trigger-based 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... Figure 35The format shown in (b) is the same.

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

[0268] When a wireless communication terminal transmits a trigger-based PPDU triggered by a trigger frame, the common information fields may include a spatial reuse field, which indicates the value of the spatial reuse field to be inserted by the corresponding wireless communication terminal into the HE-SIG-A field of the PPDU. Additionally, when a wireless communication terminal transmits a trigger-based PPDU triggered by a trigger frame, the common information fields may include a BW field, which indicates the value to be inserted by the corresponding wireless communication terminal into the BW field of HE-SIG-A. Furthermore, when a wireless communication terminal transmits a trigger-based PPDU triggered by a trigger frame, the common information fields may include a MU MIMO LTF mode field, which indicates the MU MIMO LTF mode to be used by the corresponding wireless communication terminal. Additionally, when a wireless communication terminal transmits a trigger-based PPDU triggered by a trigger frame, the common information fields may include an LTF number field, which indicates the number of LTFs to be used by the corresponding wireless communication terminal. Finally, when a wireless communication terminal transmits a trigger-based PPDU triggered by a trigger frame, the common information fields may include an STBC field, which indicates whether the wireless communication terminal uses STBC. Additionally, when a wireless communication terminal transmits a trigger-based PPDU triggered by a trigger frame, the common information field may include an LDPC appended symbol field, which indicates whether an LDPC appended symbol is present when the corresponding wireless communication terminal is used. Furthermore, when a wireless communication terminal transmits a trigger-based PPDU triggered by a trigger frame, the common information field may include an AP TX power field, which indicates the transmit power to be used by the wireless communication terminal. Additionally, when a wireless communication terminal transmits a trigger-based PPDU triggered by a trigger frame, the common information field may include a packet spread field, which indicates information about the packet spread of the PPDU transmitted by the corresponding wireless communication terminal. Other fields included in the common information field can be referenced. Figure 35 (a) is the same as the described embodiment. Specifically, the public information field can be the same as... Figure 35 The embodiment of (a) is the same.

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

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

[0271] A wireless communication terminal acting as an access point (AP) can send data frames to multiple wireless communication terminals and request the transmission of ACK frames for the corresponding data frames. Specifically, the wireless communication terminal acting as an AP can trigger the transmission of ACK frames from multiple wireless communication terminals using a trigger frame. In this case, the trigger frame type can be MU-BAR.

[0272] Additionally, when a wireless communication terminal acting as an access point (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) block ACK can be sent. In this case, the wireless communication terminal acting as the AP can trigger the GCR block ACK transmission of multiple wireless communication terminals via a trigger frame. For this purpose, the common information field of the trigger frame can include information related to GCR. The trigger frame type can be either a MU-BAR type for GCR or a MU-BAR type. Specifically, when the trigger frame type is either a MU-BAR type for GCR or a MU-BAR type, the common information field of the trigger frame can include a GCR indicator field, which indicates whether the trigger frame is a MU-BAR type for GCR. Furthermore, the common information field of the trigger frame can include a GCR address field, which indicates the address of the GCR group triggered by the trigger frame. Specifically, the common information fields included in a MU-BAR type trigger frame can be... Figure 37 The embodiment of (a) is the same.

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

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

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

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

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

[0278] The format of the trigger-related public information fields for specific MU-BAR type trigger frames can be compared with... Figure 38 The embodiments are the same.

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

[0280] The wireless communication terminal can set the RA field of a MU-BAR type trigger frame used for GCR to a GCR address. Specifically, the wireless communication terminal can set the RA field of the trigger frame to a GCR address and indicate that the trigger frame type is MU-BAR type for GCR. Therefore, the wireless communication terminal can omit the GCR address field in the public information field. In another specific embodiment, the wireless communication terminal may not set a value in the GCR address field of the public information field. Furthermore, when the wireless communication terminal sets the RA field of a MU-BAR type trigger frame used for GCR to a GCR address, the wireless communication terminal can 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 can be... Figure 39 The embodiments are the same.

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

[0282] The wireless communication terminal can set the RA field of the MU-BAR type trigger frame used for GCR to a broadcast address. At this time, the wireless communication terminal can set the GCR address field to the GCR address in the public information field. Furthermore, when the wireless communication terminal sets the RA field of the MU-BAR type trigger frame used for GCR to a broadcast address, the wireless communication terminal can request an ACK frame other than GCR BlockACK from the corresponding trigger frame. Therefore, when the wireless communication terminal sets the RA field of the MU-BAR type trigger frame used for GCR to a broadcast address, the wireless communication terminal can insert information about the wireless communication terminal corresponding to the GCR address and information about the wireless communication terminal not corresponding to the GCR address into each user information field of the trigger frame. The specific trigger frame format can be... Figure 40 The embodiments are the same.

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

[0284] As described above, when the trigger frame is of type MU-BAR, the trigger-related per-user information field of the trigger frame may include a BAR control field. In this case, multiple bits included in the trigger-related per-user information field can indicate a variant of BlockACKReq. Specifically, the multi-TID subfield, compressed bitmap subfield, and GCR subfield included in the trigger-related per-user information field can indicate a variant of BlockACKReq. 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 can be GCR BlockACKReq.

[0285] As described above, when a MU-BAR type trigger frame requests GCR BlockAck, the MU-BAR type trigger frame can request both a GCR BlockAck frame and another ACK frame. Specifically, a wireless communication terminal can use a MU-BAR type trigger frame to request ACKs for multiple TIDs from the wireless communication terminal that received the trigger frame. In a specific embodiment, a wireless communication terminal can use a MU-BAR type trigger frame to request ACKs for multiple TIDs, including a GCRBlockACK frame, from the wireless communication terminal that received the trigger frame. For example, the wireless communication terminal can set the Multi-TID Saab field to 1, set the GCR subfield to 1, request GCR BlockAck, and simultaneously request ACKs for another TID. In this case, the value of the compressed bitmap subfield can be 0 or 1. In a specific embodiment, the format of the BAR control field can be... Figure 41The same as in (a). Additionally, the encoded values ​​of the BlockACKReq variant can be as follows: Figure 41 As shown in (b).

[0286] When a trigger frame requests a GCR BlockAck frame and another ACK frame together, the wireless communication terminal can send multiple TID BlockACK frames in response to the trigger frame. Alternatively, when a trigger frame requests a GCR BlockAck frame and another ACK frame together, the wireless communication terminal can send BlockACK frames for multiple TIDs along with other MPDUs. Specifically, the wireless communication terminal can send BlockACK frames for multiple TIDs and another MPDU via an A-MDPU. In this case, the BlockACK frame can be a compressed BlockACK frame.

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

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

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

[0290] When the trigger frame is of type MU-BAR and the wireless communication terminal requests ACKs for multiple TIDs, the wireless communication terminal can generate and send BAR information fields categorized by TID. Specifically, when the trigger frame is of type MU-BAR for GCR and the wireless communication terminal requests ACKs for multiple TIDs, the wireless communication terminal can generate and send a BAR information field for each TID. In this case, the BAR information field can include a per-TID information field and a block ACK start sequence field through the TID. The per-TID information field can include a TID subfield indicating the TID. For example, the specific format of the BAR information field can be similar to... Figure 43 The implementation is the same. The length of the BAR information field can vary depending on the number of TIDs requesting ACK. Specifically, the length of the trigger-related per-user information field can vary depending on the number of TIDs requesting ACK. Therefore, the length of each user information field can vary depending on the number of TIDs requesting ACK. The wireless communication terminal sending the trigger frame can signal the number of TIDs through the TID_INFO field of the BAR control field of the trigger frame. The wireless communication terminal receiving the trigger frame can determine the length of each user information field based on the TID_INFO field of the BAR control field of the trigger frame.

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

[0292] Trigger frames can have, for example: Figure 34 The format described in [the document] is as follows. At this point, the formats of the public information fields and the per-user information fields can be the same as those in the reference [document]. Figures 35 to 36 The described embodiments are identical. Furthermore, the format of the trigger-related per-user information field can be the same as in the reference. Figure 37 The described embodiments are the same. Additionally, the format of the triggering related public information fields can be the same as in the reference. Figure 37 and Figure 38 The described embodiments are the same. Furthermore, the format of the BAR information field can be the same as the reference. Figure 43 The described embodiments are the same.

[0293] Figure 45 The operation of a wireless communication terminal according to an embodiment of the present invention is illustrated.

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

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

[0296] Furthermore, when a 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 BSS color. As mentioned above, this is because BSS color values ​​may have BSS color conflicts due to value limitations. In a specific embodiment, the wireless communication terminal can refer to a reference... Figures 6 to 23 The described embodiments are used to identify whether a received PPDU is an inter-BSS PPDU or an intra-BSS PPDU. Specifically, when a PPDU received by a 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] The wireless communication terminal can perform channel access-related operations based on whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU. Furthermore, the wireless communication terminal can enter a power-saving mode (S4505) depending on whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU. In this mode, the channel access-related operations can include at least one of operations for setting a CCA threshold and operations for setting / resetting the NAV.

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

[0299] When a PPDU received by a wireless communication terminal may not be identified as an inter-BSS PPDU or an intra-BSS PPDU, the wireless communication terminal may enter power-saving mode without relying on the BSS color signaled via the PPDU.

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

[0301] Additionally, when the NAV is set by means of a PPDU that cannot be identified as an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color value indicated by the signaling field of the PPDU, the wireless communication terminal may reset the NAV without based on a CF-End frame sent from within the BSS or from a BSS corresponding to a set of multiple BSSIDs that includes the BSSID corresponding to the wireless communication terminal's BSS.

[0302] The following situations may occur where a PPDU received by a wireless communication terminal is not identified as an inter-BSS PPDU or an intra-BSS PPDU: Due to BSS color conflict, it may be impossible to identify whether a PPDU received by the wireless communication terminal based on BSS color is an inter-BSS PPDU or an intra-BSS PPDU. If the wireless communication terminal cannot identify whether a PPDU received based on 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 identify whether a PPDU received based on 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 a wireless communication terminal receives a signaling message indicating that operation based on BSS color is not allowed, the wireless communication terminal can set the NAV within the BSS without relying on the BSS color and the TXOP duration field of the HE-SIG-A field of the PPDU.

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

[0304] Specifically, if the wireless communication terminal cannot identify whether the PPDU received based on the BSS color is an inter-BSS PPDU or an intra-BSS PPDU, the wireless communication terminal can enter power-saving mode without sending a signal to the BSS color based on the HE-SIG-A field of the received PPDU.

[0305] Furthermore, when a PPDU received by a wireless communication terminal may not be identified as an inter-BSS PPDU or an intra-BSS PPDU, this could be due to the received PPDU lacking information to identify the BSS from which it was sent. Specifically, when a PPDU received by a wireless communication terminal is not identified as an inter-BSS PPDU or an intra-BSS PPDU, the wireless communication terminal may not decode the MAC header of the MAC frame included in the PPDU. Additionally, the situation where a PPDU received by a wireless communication terminal is not identified as an inter-BSS PPDU or an intra-BSS PPDU may be due to the inability to identify whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU using the methods described above.

[0306] Furthermore, the wireless communication terminal can send a PPDU by including signaling information indicating that BSS color-based operations are not allowed in the signaling field of the PPDU. In this case, the wireless communication terminal receiving the PPDU including the corresponding signaling information can choose not to perform BSS color-based operations. In a specific embodiment, the wireless communication terminal can send the BSS color value indicated by the PPDU by setting the signaling field of the PPDU to a predetermined value. In this case, the predetermined value can be a reserved value that is not used in the BSS color selection when the BSS color is chosen by the AP. For example, the predetermined value can be zero. Furthermore, when the wireless communication terminal receives a PPDU indicating a predetermined value as the BSS color, the wireless communication terminal can choose not to perform BSS color-based operations. Specifically, when the wireless communication terminal receives a PPDU indicating a predetermined value in the BSS color, the wireless communication terminal can choose not to perform SR operations on the corresponding PPDU. In a specific embodiment, when the wireless communication terminal receives a PPDU indicating a predetermined value in the BSS color, the wireless communication terminal can consider the PPDU as an in-BSS PPDU. Therefore, when the wireless communication terminal receives a PPDU indicating a predetermined value in the BSS color, the wireless communication terminal can choose not to discard the corresponding PPDU.

[0307] As described above, a wireless communication terminal can send a BSS color indicating its own BSS when communicating with another wireless communication terminal. In this case, if the wireless communication terminal does not receive a signaling notification of the BSS color, it can send a predetermined value as the BSS color. This predetermined value can be a reserved value not used in the BSS color selection process by the AP. For example, the predetermined value can be zero. Specifically, when the wireless communication terminal does not receive a signaling notification of the BSS color, a non-AP wireless communication terminal can 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 a signaling notification of the BSS color, it can set the BSS color value signaled by the PPDU sent by the wireless communication terminal to the predetermined value. Additionally, when the wireless communication terminal does not receive a signaling notification of the BSS color, it can set the BSS color value signaled by the frame sent by the wireless communication terminal to the predetermined value. When the wireless communication terminal does not receive a signaling notification of the BSS color, there is no BSS color. Specifically, when the wireless communication terminal does not receive information signaling for the BSS color, it may not be associated with any AP. Additionally, situations where a wireless communication terminal fails to receive information regarding the signal notification of BSS color may include the following: the wireless communication terminal fails to establish a Tunnel Direct Link Setup (TDLS) link, a Direct Link Setup (DLS) link, or IBSS (Independent) membership. Furthermore, situations where a wireless communication terminal fails to receive information regarding the signal notification of BSS color may include the following: the wireless communication terminal may not receive information about the changed BSS color value after receiving a message indicating that operation based on the BSS color value is not permitted. Moreover, a PPDU that uses a predetermined signal notification value as the BSS color may be identified as an inter-BSS PPDU or an intra-BSS PPDU, without being based on the predetermined value of the BSS color.

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

[0309] At this point, 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 the 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 can treat the PPDU as a PPDU within the BSS. 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 a wireless communication terminal accesses a channel or enters power-saving mode, the specific operation of the wireless communication terminal can be referenced. Figures 6 to 23 The embodiments described are identical.

[0311] Although the invention has been described using wireless LAN communication as an example, it is not limited thereto and can be applied to other communication systems such as cellular communication. Additionally, while the methods, apparatus, and systems of the invention have been described together with specific embodiments thereof, some or all of the components or operations of the invention may be implemented using a computer system with a general-purpose 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. Furthermore, 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 anything relating to such combinations and modifications is included within the scope of the present invention.

[0313] While the present invention has been described primarily based on the embodiments described above, it 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 invention. For example, each component specifically shown in the embodiments can be modified and implemented. It should be understood that differences relating to such modifications and applications are included within the scope of the invention as defined in the appended claims.

Claims

1. A wireless communication station, the station comprising: transceiver; as well as processor, The processor is configured to receive Physical Layer Convergence Protocol Data Units (PPDUs) via the transceiver, and When signaling information indicates that operation based on the Basic Service Set (BSS) color is not permitted, the Network Allocation Vector (NAV) within the Basic Service Set (BSS) is not set by using the BSS color indicated by the signaling field of the PPDU. Wherein, the BSS color is the identifier of the BSS. The value of the BSS color of the BSS to which the station belongs is set by the access point associated with the station and obtained from the HE operation element sent by the access point. The signaling information is sent from the access point. The NAV within the BSS differs from the basic NAV and is a NAV set up based on the PPDU within the BSS. The basic NAV is set based on inter-BSS PPDUs, or PPDUs that cannot be identified as inter-BSS PPDUs or intra-BSS PPDUs. Wherein, the BSS within a BSS includes the BSS of the station, and the BSSs between BSSs are different from those within the BSS. Specifically, when a BSS color conflict is detected, a signaling message indicating that operation based on the BSS color is not allowed is set, and The BSS color conflict refers to different BSSs corresponding to a single BSS color.

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

3. The station according to claim 1, wherein, The processor is configured to signal that operations based on the BSS color are not allowed when the station identifies that a BSS color conflict has occurred.

4. The station according to claim 3, wherein, The processor is configured to determine that the BSS color conflict has occurred based on the address field of the Media Access Control (MAC) frame.

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

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

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

8. A method for operating a wireless communication station, the method comprising: Receive Physical Layer Convergence Process PLCP Protocol Data Unit (PPDU); as well as When signaling information indicates that operation based on the Basic Service Set (BSS) color is not permitted, the operation based on the BSS color is not performed. Wherein, the BSS color is the identifier of the BSS. The value of the BSS color of the BSS to which the station belongs is set by the access point associated with the station and obtained from the HE operation element sent by the access point. The signaling information is sent from the access point. Specifically, when the signaling information indicates that 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. The NAV within the BSS differs from the basic NAV and is a NAV set up based on the PPDU within the BSS. The basic NAV is set based on inter-BSS PPDUs, or PPDUs that cannot be identified as inter-BSS PPDUs or intra-BSS PPDUs. Wherein, the BSS within a BSS includes the BSS of the station, and the BSSs between BSSs are different from those within the BSS. Specifically, when a BSS color conflict is detected, a signaling message indicating that operation based on the BSS color is not allowed is set, and The BSS color conflict refers to different BSSs corresponding to a single BSS color.

9. The method according to claim 8, wherein, The PPDU includes a Media Access Control (MAC) frame, wherein the signaling fields of the PPDU include a Transmission Opportunity (TXOP) duration field, and wherein the MAC frame includes a duration field. The TXOP duration field indicates information used to set the NAV within the BSS and the base NAV. The duration field indicates information used to set the NAV within the BSS and the base NAV. The method further includes, when the station obtains the valid signaling field of the MAC frame, not using the TXOP duration field to set the NAV within the BSS or the basic NAV.

10. The method according to claim 8, wherein, The method further includes: when the station identifies that the BSS color conflict has occurred, sending a signal to disallow operations based on the BSS color.

11. The method according to claim 10, wherein, The signal transmission disallowing operations based on the BSS color includes determining that a 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, Operations based on the BSS color include entering a power-saving sleep state based on the BSS color indicated by the signaling field of the PPDU. The power-saving operation is an operation used by the station to enter the sleep state until the PPDU received as a PPDU within the BSS is terminated.

13. The method according to claim 8, wherein, The method further includes not performing a space 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.

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