Wireless communication method using bss identifier and wireless communication terminal thereof

Abstract

The present invention relates to a wireless communication method using a BSS identifier and a wireless communication terminal thereof. A wireless communication terminal of wireless communication is disclosed. The wireless communication terminal includes a transmitting and receiving unit for transmitting and receiving a wireless signal, and a processor for processing the wireless signal. The processor generates a trigger frame for triggering uplink transmission based random access of at least one wireless communication terminal, and inserts the trigger frame into a physical layer protocol data unit (PPDU) to transmit the PPDU.

Description

[0001] This application is a divisional application of patent application No. 201880024847.X (PCT / KR2018 / 004397), filed with the China Patent Office on October 12, 2019, with an international application date of April 16, 2018, entitled "Wireless Communication Method Using BSS Identifier and Wireless Communication Terminal Using the Method". Technical Field

[0002] This invention relates to a wireless communication method and a wireless communication terminal using BSS identifiers. 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, and embedded devices, 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 access points (APs), 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 the access point (AP). Summary of the Invention

[0009] Technical issues

[0010] The purpose of embodiments of the present invention is to provide a wireless communication terminal using a BSS identifier.

[0011] Technical solutions

[0012] According to an embodiment of the present invention, a wireless communication base station wireless communication terminal includes a transceiver configured to transmit and receive wireless signals; and a processor configured to process the wireless signals. The processor may be configured to: generate a trigger frame for triggering random access based on uplink transmission for at least one wireless communication terminal, and insert the trigger frame into a physical layer protocol data unit (PPDU) to transmit the PPDU.

[0013] When a trigger frame triggers random access based on uplink transmission by a wireless communication terminal that is not associated with a Basic Service Set (BSS) operated by a base station wireless communication terminal, the processor can be configured to send a PPDU using a PPDU format that includes a field indicating the BSS color. In this case, the BSS color can be an identifier used to identify the BSS.

[0014] More specifically, when a trigger frame triggers random access based on uplink transmission to a wireless communication terminal that is not associated with a BSS operated by a base station wireless communication terminal, the processor can use the high-efficiency (HE)PPDU format to send PPDUs.

[0015] In another specific embodiment, when a trigger frame triggers random access based on uplink transmission to a wireless communication terminal not associated with a BSS operated by a base station wireless communication terminal, the processor can be configured to insert a field indicating the BSS color into the trigger frame. In this case, the BSS color can be an identifier used to identify the BSS.

[0016] Specifically, the processor can be configured to insert a field indicating the BSS color into a user information field, which is used to send information via signaling to one or more wireless communication terminals that are individually applied to trigger transmission via a trigger frame. In another specific embodiment, the field indicating the BSS color can be inserted into a common information field, which is used to send via signaling information that is commonly applied to one or more wireless communication terminals that are triggered transmission via a trigger frame.

[0017] The processor can be configured to set a specific field of the trigger frame to a predetermined associated ID (AID) value to trigger random access to a wireless communication terminal that is not associated with a BSS operated by a base station wireless communication terminal.

[0018] The processor can be configured to send trigger frames based on a predetermined schedule. In this case, the trigger frame triggers random access based on uplink transmission by a wireless communication terminal that is performing power-saving operations according to the predetermined schedule.

[0019] More specifically, the processor can be configured to set the receiver address (RA) field of the trigger frame to a group address indicating a wireless communication terminal that performs power-saving operations based on a predetermined schedule.

[0020] In another specific embodiment, the trigger frame may include a user information field for signaling information applied individually to one or more wireless communication terminals that trigger the transmission, and the processor may be configured to set the value of the association ID (AID) indicated by the user information field corresponding to a frequency band allocated for random access based on uplink transmission to a predetermined value indicating that a wireless communication terminal is performing power-saving operations based on a predetermined schedule. In this case, the predetermined value may be a reserved value not allocated for another purpose.

[0021] In another specific embodiment, the trigger frame may include a user information field for signaling information applied individually to one or more wireless communication terminals that trigger the transmission, and the processor may set a TID aggregation limit field included in the user information field corresponding to a frequency band allocated for random access based on uplink transmission to a predetermined value indicating a wireless communication terminal performing power-saving operations based on a predetermined schedule. In this case, the TID aggregation limit field may be a field indicating a limit on the number of TIDs corresponding to the data that can be aggregated in the A-MPDU transmitted based on the trigger frame.

[0022] According to an embodiment of the present invention, a wireless communication terminal that communicates wirelessly with a base station wireless communication terminal includes a transceiver configured to transmit and receive wireless signals; and a processor configured to process the wireless signals. The processor may be configured to: receive a Physical Layer Protocol Data Unit (PPDU) including a trigger frame for triggering a transmission to the base station wireless communication terminal, and transmit a trigger-based PPDU based on the trigger frame.

[0023] When a PPDU including a trigger frame indicates a Basic Service Set (BSS) color, the processor can be configured to set the value of the BSS color indicated by the trigger-based PPDU based on the value of the BSS color indicated by the PPDU including the trigger frame. In this case, the BSS color can be one of the identifiers that identifies the BSS.

[0024] Furthermore, if the PPDU including the trigger frame does not indicate the BSS color, the processor can be configured to set the value of the BSS color indicated by the trigger-based PPDU according to the valid BSS color of the wireless communication terminal. In this case, the valid BSS color can indicate the BSS color actually used by the wireless communication terminal.

[0025] The processor can be configured to receive information about BSS color changes from a base station wireless communication terminal. In this case, when the BSS color change time point indicated by the information about the BSS color change is reached, the processor can be configured to set the effective BSS color to the value of the BSS color indicated by the information about the BSS color change.

[0026] The BSS color change time point can be set based on the target beacon transmission time sent by the base station wireless communication terminal.

[0027] If a PPDU uses a Partial Association ID (AID) field to indicate a portion of the BSS color, the processor can determine whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the portion of the BSS color when the value of the Partial AID field is non-zero. In this case, the Partial AID field can be a signaling field used to indicate a portion of the AID value. Furthermore, an intra-BSS PPDU can be a PPDU transmitted from a BSS that includes a wireless communication terminal, and an inter-BSS PPDU can be a PPDU transmitted from a BSS that does not include a wireless communication terminal.

[0028] According to an embodiment of the present invention, a method for a base station wireless communication terminal to perform wireless communication includes generating a trigger frame for triggering random access based on uplink transmission of at least one wireless communication terminal; and inserting the trigger frame into a physical layer protocol data unit (PPDU) to transmit the PPDU.

[0029] Sending a PPDU may include: when a trigger frame triggers random access based on uplink transmission of a wireless communication terminal that is not associated with the Basic Service Set (BSS) operated by the base station wireless communication terminal, sending a PPDU in a format that includes a field of the BSS color of the Basic Service Set (BSS) operated by the base station wireless communication terminal.

[0030] Function of the present invention

[0031] Embodiments of the present invention provide a wireless communication method using a BSS identifier and a wireless communication terminal using the method. Attached Figure Description

[0032] Figure 1 A wireless LAN system according to an embodiment of the present invention is shown.

[0033] Figure 2 A wireless LAN system according to another embodiment of the present invention is shown.

[0034] Figure 3 A block diagram illustrating the configuration of a station according to an embodiment of the present invention is shown.

[0035] Figure 4 A block diagram illustrating the configuration of an access point according to an embodiment of the present invention is shown.

[0036] Figure 5 The process of setting up access points and links at a site according to an embodiment of the present invention is illustrated.

[0037] Figure 6 The illustration shows an operation in which multiple wireless communication terminals send trigger-based PPDUs based on trigger frames, according to an embodiment of the present invention.

[0038] Figure 7 The trigger frame format according to an embodiment of the present invention is shown.

[0039] Figure 8 The format of the public information field and the user information field included in the trigger frame according to an embodiment of the present invention is shown.

[0040] Figure 9 A method for performing random access by a wireless communication terminal according to an embodiment of the present invention is shown.

[0041] Figure 10 The specific format of the UORA parameter set element according to an embodiment of the present invention is shown.

[0042] Figure 11 This invention illustrates a method for determining whether a PPDU received by a wireless communication terminal is an intra-BSS PPDU or an inter-BSS PPDU.

[0043] Figure 12 This illustrates a power-saving operation of a wireless communication terminal according to an embodiment of the present invention.

[0044] Figure 13 This illustrates the operation of UL MU transmission performed by a wireless communication terminal according to an embodiment of the present invention.

[0045] Figure 14This invention illustrates a method for configuring the BSS color of a corresponding PPDU when a base station wireless communication terminal sends a PPDU including a trigger frame, the trigger frame triggering transmissions by wireless communication terminals not associated with the base station wireless communication terminal and wireless communication terminals associated with the base station wireless communication terminal.

[0046] Figure 15 This invention illustrates a method for configuring the BSS color of a corresponding PPDU when a base station wireless communication terminal sends a PPDU to a wireless communication terminal included in a set of multiple BSSIDs of a BSS operated by the base station wireless communication terminal.

[0047] Figure 16 The format of the user information field in the trigger frame according to an embodiment of the present invention is shown.

[0048] Figure 17 A method is shown in which, when a wireless communication terminal according to an embodiment of the invention sends a triggered PPDU to a base station wireless communication terminal that is not associated with the wireless communication terminal, the wireless communication terminal sets a value of the BSS color indicated by the triggered PPDU.

[0049] Figure 18 This invention illustrates a method for setting the TXVECTOR parameters GROUP_ID and PARTIAL_AID of a VHT SU PPDU in a wireless communication terminal according to an embodiment of the present invention.

[0050] Figure 19 This is a view that uses the value of a portion of the AID field of the signaling field of the VHT PPDU received by the wireless communication terminal to determine whether the VHT PPDU received by the wireless communication terminal according to an embodiment of the present invention is an inter-BSS PPDU or an intra-BSS PPDU.

[0051] Figure 20 This illustrates the setting of the TXOP duration field of a PPDU in a wireless communication terminal according to an embodiment of the present invention.

[0052] Figure 21 This illustrates a wireless communication terminal setting the TXOP duration field of the PPDU according to another embodiment of the present invention.

[0053] Figure 22 A wireless communication terminal according to an embodiment of the present invention is shown performing UL MU transmission.

[0054] Figure 23 A wireless communication terminal according to another embodiment of the present invention is shown performing UL MU transmission.

[0055] Figure 24The encoded value of the RU allocation field used by a wireless communication terminal according to an embodiment of the present invention is shown.

[0056] Figure 25 This illustration shows UL MU transmission for a base station wireless communication terminal that is not associated with a wireless communication terminal, according to an embodiment of the present invention.

[0057] Figure 26 This invention illustrates a method for generating an A-MPDU by aggregating MPDUs via a base station wireless communication terminal, according to an embodiment of the present invention.

[0058] Figure 27 A method for generating an A-MPDU from a wireless communication terminal according to another embodiment of the present invention is shown.

[0059] Figure 28 This invention illustrates a method for controlling EDCA parameters used by a wireless communication terminal during MU UL transmission.

[0060] Figure 29 A method for transmitting a BSR by a wireless communication terminal according to an embodiment of the present invention is shown.

[0061] Figure 30 The target wake-up time (TWT) operation of a wireless communication terminal according to an embodiment of the present invention is illustrated.

[0062] Figure 31 This illustration shows a wireless communication terminal according to an embodiment of the present invention setting MU EDCA parameters during TWT operation.

[0063] Figure 32 The operation of a base station wireless communication terminal and a wireless communication terminal according to an embodiment of the present invention is illustrated. Detailed Implementation

[0064] 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.

[0065] 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.

[0066] This application claims priority and benefit to Korean Patent Applications No. 10-2017-0048762 (2017.04.14), No. 10-2017-0146358 (2017.11.04), and No. 10-2017-0146356 (2017.11.04) filed with the Korean Intellectual Property Office, and the embodiments and references described in the respective applications are included in the specific embodiments of this application.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] An access point (AP) is an entity that provides access to a distribution system (DS) for its associated stations via wireless media. 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.

[0071] 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).

[0072] 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.

[0073] 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.

[0074] Figure 3 This is a block diagram illustrating the configuration of station 100 according to an embodiment of the present invention.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] Figure 4 This is a block diagram illustrating the configuration of AP 200 according to an embodiment of the present invention.

[0082] 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... will be omitted. Figure 2 Repeated descriptions of the same or corresponding parts of the components of station 100.

[0083] 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.

[0084] 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.

[0085] Figure 5 This is a schematic diagram illustrating the process of setting up the link between the STA and the AP.

[0086] 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).

[0087] STA 100, having successfully received wireless access information during the scanning step, performs an 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 an association step by sending an association request (S109a) and receiving an association response from AP 200 (S109b). In this specification, association essentially means wireless combination, but the invention is not limited thereto and can broadly include both wireless and wired combinations.

[0088] 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.

[0089] In a specific embodiment, AP 200 can be a wireless communication terminal that allocates communication media resources and performs scheduling in an independent network (such as an ad hoc network) not connected to an external distribution service. Furthermore, AP 200 can be at least one of a base station, eNB, and transmission point TP. TP 200 can also be referred to as a base station communication terminal.

[0090] A base station wireless communication terminal can be a wireless communication terminal that allocates and schedules media resources for communication with multiple wireless communication terminals. Specifically, a base station wireless communication terminal can act as a cell coordinator. In a particular embodiment, a base station wireless communication terminal can be a wireless communication terminal that allocates and schedules communication media resources in an independent network (such as an ad-hoc network) that is not connected to an external distribution service.

[0091] When using Orthogonal Frequency Division Multiplexing (OFDMA) or Multiple-Input Multiple-Output (MIMO) to transmit data, any one wireless communication terminal can simultaneously send data to multiple wireless communication terminals. Furthermore, any one wireless communication terminal can simultaneously receive data from multiple wireless communication terminals.

[0092] For ease of description, any one of the wireless communication terminals communicating simultaneously with multiple wireless communication terminals is referred to as a base station wireless communication terminal. Furthermore, a base station wireless communication terminal can be referred to as a base station communication device. Additionally, a base station wireless communication terminal can be a wireless communication terminal that allocates communication medium resources and performs scheduling by communicating with multiple wireless communication terminals. Specifically, a base station wireless communication terminal can act as a cell coordinator. In this case, the base station wireless communication terminal can be access point 200. Furthermore, the multiple wireless communication terminals can be stations 100 associated with access point 200. In a particular embodiment, a base station wireless communication terminal can 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. Additionally, a base station wireless communication terminal can be at least one of a base station, an eNB, and a transport point TP. Figures 6 to 32 This will describe the operation of multiple wireless communication terminals sending data and base station wireless communication terminals receiving data.

[0093] Figure 6 The illustration shows an operation in which multiple wireless communication terminals transmit trigger-based PPDUs based on trigger frames, according to an embodiment of the present invention.

[0094] A base station wireless communication terminal can send a trigger frame including trigger information, which is used to trigger uplink multi-user response scheduling (UMRS) of at least one wireless communication terminal's transmission or MAC header. At least one wireless communication terminal receiving the trigger frame or UMRS including trigger information can send a trigger-based PPDU based on the trigger information. The trigger-based PPDU can indicate a PPDU including a response frame to the trigger frame. More specifically, the trigger-based PPDU can indicate a HE-based trigger-based PPDU. One or more wireless communication terminals can simultaneously send trigger-based PPDUs to the base station wireless communication terminal using at least one of MU-MIMO and OFDMA. In this case, one or more wireless communication terminals can send the trigger-based PPDU within a predetermined time period starting from the receipt of the trigger frame or UMRS including trigger information. This predetermined time period can be SIFS. Alternatively, sending a response frame to a frame received by the wireless communication terminal within the predetermined time period can be called an immediate response.

[0095] As described above, UMRS can include trigger information. Furthermore, UMRS can be included in the A-Control field of the MAC header. Additionally, one or more wireless communication terminals can transmit a non-HT PPDU in response to the trigger frame. Specifically, when the trigger frame is of type MU-RTS, one or more wireless communication terminals can transmit a non-HT PPDU in response to the trigger frame.

[0096] Furthermore, the A-MPDU may include trigger information. More specifically, the A-MPDU may include trigger frames. An A-MPDU may include two or more trigger frames. In this case, the content of the trigger frames may be identical. Additionally, when including an A-MPDU trigger frame, the base station wireless communication terminal may not be allowed to include in the A-MPDU an MPDU that includes uplink transmissions of the same wireless communication terminal that triggered the uplink transmission in which the trigger frame triggered the UMRS.

[0097] exist Figure 6 In this embodiment, the AP sends a trigger frame to stations STA1 through STA4. STA1 through STA4 receive the trigger frame and simultaneously send a trigger-based PPDU to the AP based on the trigger frame. The AP receives the trigger-based PPDU and sends an ACK frame based on the MPDU included in the trigger-based PPDU. (See reference...) Figure 7 Describe the specific format of the trigger frame.

[0098] Figure 7 The trigger frame format according to an embodiment of the present invention is shown. Figure 8 The format of the public information field and the user information field included in the trigger frame according to an embodiment of the present invention is shown.

[0099] The trigger frame may include information about the wireless communication terminal in which the trigger frame triggers a transmission. Specifically, the trigger frame may include a common information field indicating information commonly applied to at least one wireless communication terminal in which the trigger frame triggers an uplink transmission. Additionally, the trigger frame may include a user information field indicating information individually applied to at least one wireless communication terminal in which the trigger frame triggers an uplink transmission. In a particular embodiment, the trigger frame may include a frame control field, a duration field, an RA field, a TA field, a common information field, at least one user information field, a padding field, and an FCS field, as shown in... Figure 7 In the embodiments described above.

[0100] The RA field can indicate the address of the station receiving the trigger frame. When only one wireless communication terminal is triggered by the trigger frame, the RA field can indicate the address of the corresponding wireless communication terminal. When more than one wireless communication terminal is triggered by the trigger frame, the RA field can indicate the broadcast address. When the trigger type of the trigger frame is GCR MU-BAR, the RA field can indicate the address of the group of wireless communication terminals requesting the transmission of the receive status.

[0101] The TA field can indicate the address of the station that sent the trigger frame. When the base station wireless communication terminal does not use multiple BSSIDs, the TA field can indicate the MAC address of the base station wireless communication terminal that sent the trigger frame. Additionally, when the base station wireless communication terminal uses multiple BSSIDs and sends a trigger frame to another wireless communication terminal to communicate with it, the TA field can indicate the MAC address of the base station wireless communication terminal. In this case, the wireless communication terminals communicating with the base station wireless communication terminal can include not only those associated with the base station wireless communication terminal but also those not associated with it. Furthermore, when the base station wireless communication terminal uses multiple BSSIDs and sends a trigger frame to multiple wireless communication terminals communicating with two or more BSSIDs from the multiple BSSID sets, the TA field can indicate the BSSID that was sent.

[0102] Padding fields can indicate meaningless data. More specifically, when the wireless communication terminal receiving the trigger frame needs time to ensure preparation for the response transmission of the trigger frame, the base station wireless communication terminal can insert a padding field into the trigger frame. In this case, the base station wireless communication terminal can determine the length of the padding field based on its ability to receive the trigger frame. When the wireless communication terminal receiving the trigger frame does not need time for preparing the response transmission of the trigger frame, the base station wireless communication terminal may not insert a padding field into the trigger frame. The base station wireless communication terminal can indicate the start of the padding field by setting the beginning portion of the padding field to a specific value. In this case, the specific value can be 0xFFF (4095). Alternatively, the base station wireless communication terminal can set the remaining portion of the padding field, excluding the beginning portion, to a value different from the specific value.

[0103] More specifically, the user information field may indicate the frequency band allocated to the wireless communication terminal triggered by the trigger frame. The user information field may include a wireless communication terminal identifier for identifying the wireless communication terminal triggered by the trigger frame and information indicating the bandwidth of the frequency band allocated to the wireless communication terminal. In this case, the wireless communication terminal identifier may be an identifier used to shorten the associated ID (AID). For example, the trigger frame may include an identifier for shortening the AID of the wireless communication terminal triggered by the trigger frame and an index indicating the frequency band allocated to the wireless communication terminal. In this case, the identifier for shortening the AID may be the 12 least significant bits (LSBs) of the AID. According to a particular embodiment, the user information field may include an AID12 field indicating the wireless communication terminal identifier used to identify the wireless communication terminal triggered by the trigger frame.

[0104] A base station wireless communication terminal can set the value of the wireless communication terminal identifier in the user information field to a specific value to indicate that the frequency band of the corresponding user information field is allocated for random access. More specifically, the base station wireless communication terminal can set the value of the wireless communication terminal identifier in the user information field to a first specific value to indicate that the frequency band of the corresponding user information field is allocated for random access by wireless communication terminals associated with the base station wireless communication terminal. Additionally, the base station wireless communication terminal can set the value of the wireless communication terminal identifier in the user information field to a first specific value to indicate that the frequency band of the corresponding user information field is allocated for random access by wireless communication terminals not associated with the base station wireless communication terminal. In this case, the first specific value can be 0. Furthermore, the second specific value can be 2045. Wireless communication terminals not associated with the base station wireless communication terminal can be wireless communication terminals not associated with any base station wireless communication terminal.

[0105] The user information field may indicate the frequency band allocated to the wireless communication terminal in the form of resource units (RUs). More specifically, the user information field may include an RU allocation field indicating the RU allocated to the wireless communication terminal corresponding to the user information field.

[0106] As mentioned above, the wireless communication terminal receiving the trigger frame may need time to prepare to send a response to the trigger frame. In this case, the base station wireless communication terminal can insert a padding field into the trigger frame based on the time required for the wireless communication terminal to prepare to send a response to the trigger frame. The minimum time required for the wireless communication terminal to prepare to send a response to the trigger frame can be called MinTrigProcTime. When the base station wireless communication terminal sends a trigger frame that triggers random access, it cannot determine which wireless communication terminal will perform the transmission via random access. Therefore, there is a problem with the method by which the base station wireless communication terminal sets the fields of the trigger frame to ensure that the wireless communication terminal has the necessary time to prepare to send a response to the trigger frame when sending a trigger frame that triggers random access.

[0107] When a trigger frame triggers random access to a wireless communication terminal associated with a base station wireless communication terminal, the base station wireless communication terminal can set the fields of the trigger frame based on the MinTrigProcTime of the wireless communication terminal explicitly triggered by the trigger frame. Specifically, when a trigger frame triggers random access to a wireless communication terminal associated with a base station wireless communication terminal, the base station wireless communication terminal can set the fields of the trigger frame based on the longest MinTrigProcTime among the MinTrigProcTimes of the wireless communication terminals explicitly triggered by the trigger frame. In this case, the wireless communication terminal explicitly triggered by the trigger frame can indicate the wireless communication terminal indicated by the identifier of the wireless communication terminal through the aforementioned user information field. In another specific embodiment, when a trigger frame triggers random access to a wireless communication terminal associated with a base station wireless communication terminal, the base station wireless communication terminal can set the fields of the trigger frame based on the longest MinTrigProcTime among the MinTrigProcTimes of the wireless communication terminals associated with the base station wireless communication terminal.

[0108] When a trigger frame triggers random access to a wireless communication terminal not associated with the base station's wireless communication terminal, the base station's wireless communication terminal can set the fields of the trigger frame based on the maximum value among the MinTrigProcTime values ​​that the wireless communication terminal can transmit signals. In this case, the maximum value among the MinTrigProcTime values ​​that the wireless communication terminal can transmit signals can be 16µs.

[0109] In the above embodiments, the base station wireless communication terminal sets at least one of the following: padding field, A-MPDU padding, A-MPDU subframe, EOF padding, frame, and frame reservation field, so as to ensure the time required to prepare to send a response to the trigger frame.

[0110] Additionally, the base station wireless communication terminal can be inserted before the user information field indicating any of the wireless communication terminals, except for the user information field indicating random access. For example, the base station wireless communication terminal can insert a user information field including a value other than 0 and 2045 in the AID12 subfield before the user information field including a value of 0 or 2045 in the AID12 subfield.

[0111] The specific formats for user information fields and public information fields can be customized. Figure 8 As shown in (a) and 8(b).

[0112] Figure 9 A method for performing random access by a wireless communication terminal according to an embodiment of the present invention is shown.

[0113] For reference Figure 8In the described embodiments, the base station wireless communication terminal can use a trigger frame to trigger random access. In this case, the wireless communication terminal can use OFDMA to randomly access the frequency band indicated by the trigger frame. More specifically, the wireless communication terminal can access RUs allocated for random access based on any number within the OFDMA Contention Window (OCW). In this case, the random number is called the OFDMA Backoff (OBO) counter. More specifically, the wireless communication terminal receiving the trigger frame that triggers random access can decrement the OBO counter by the number of RUs allocated for random access. The wireless communication terminal associated with the base station wireless communication terminal can decrement the OBO counter by the number of RUs indicated by the trigger frame as allocated for random access by the wireless communication terminal associated with the base station wireless communication terminal. Additionally, the wireless communication terminal not associated with the base station wireless communication terminal can decrement the OBO counter by the number of RUs indicated by the trigger frame as allocated for random access by the wireless communication terminal not associated with the base station wireless communication terminal.

[0114] When the OBO counter becomes 0, the wireless communication terminal is allowed to access any RU allocated for random access. Specifically, when the OBO counter becomes 0, the wireless communication terminal can randomly select any of the RUs allocated for random access to access the selected RU. In a particular embodiment, a wireless communication terminal associated with a base station wireless communication terminal can randomly select any of the RUs indicated by a trigger frame as allocated for random access by the wireless communication terminal associated with the base station wireless communication terminal. Additionally, a wireless communication terminal not associated with a base station wireless communication terminal can randomly select any of the RUs indicated by a trigger frame as allocated for random access by the wireless communication terminal not associated with the base station wireless communication terminal. When the selected RU is busy, the wireless communication terminal can stop accessing that RU and keep the OBO counter at 0. When at least one RU is busy according to physical carrier sensing and virtual carrier sensing, the wireless communication terminal can determine that the RU is busy. In this case, the wireless communication terminal can perform physical carrier sensing and virtual carrier sensing according to the carrier sensing method in the ULMU process.

[0115] When a wireless communication terminal receives a new UL OFDMA Random Access (UORA) parameter set element from a base station wireless communication terminal or performs random access for the first time, the wireless communication terminal can set the OCW to its minimum value, OCWmin. In this case, the UORA parameter set element can be an element that is used to transmit parameters for OFDMA random access via signaling. (See reference...) Figure 10The UORA parameter set elements are described in detail. Additionally, the base station wireless communication terminal can be a base station wireless communication terminal associated with another wireless communication terminal. The base station wireless communication terminal can be a base station wireless communication terminal that receives uplink transmissions to be performed by the wireless communication terminal. Furthermore, in the case of unassociated wireless communication terminals, the base station wireless communication terminal can be a base station wireless communication terminal that sends UORA parameter set elements or sends trigger frames.

[0116] Additionally, the wireless communication terminal can adjust the OCW value based on the transmission results using random access. In this case, the OCW value can indicate the maximum value of the range indicated by the OCW, and the minimum value of the range indicated by the OCW can be 0. More specifically, the wireless communication terminal can randomly select one of the natural numbers from 0 to the OCW value and set it as the OBO counter. When the wireless communication terminal cannot transmit using random access, it can set the OCW value to (2*OCW+1). In this case, the wireless communication terminal can obtain the OBO counter again using the newly set OCW. When the OCW value is the maximum value that the OCW value can have, OCWmax, the wireless communication terminal can maintain the OCW value as is. The wireless communication terminal can obtain OCWmin and OCWmax from the base station wireless communication terminal. More specifically, the wireless communication terminal can obtain OCWmin and OCWmax from the UORA parameter set elements received from the base station wireless communication terminal. The base station wireless communication terminal can send UORA parameter set elements using beacon frames or probe response frames.

[0117] exist Figure 9 In this embodiment, the first station STA1 and the second station STA2 are associated with the AP that sent the trigger frame or with an AP included in the same set of multiple BSSIDs. The OBO counter of the first station STA1 is 5, and the OBO counter of the second station STA2 is 1. The first station STA1 and the second station STA2 receive a trigger frame from the AP indicating that two RUs have been allocated for random access. The first station STA1 and the second station STA2 decrement their OBO counters by 2. Because the OBO counter of the second station STA2 reaches 0, the second station STA2 randomly selects one of the two RUs indicated by the trigger frame as being allocated for random access, and then attempts to transmit through the selected RU to the AP. The second station STA2 receives an ACK from the AP for the transmission to the AP. In this case, the second station STA2 sets the OCW to OCWmin and obtains a new OBO counter value of 6 in the newly set OCW.

[0118] The OBO counter of station STA1 is 3, and the OBO counter of station STA2 is 6. Stations STA1 and STA2 receive a trigger frame from the AP instructing them to allocate three RUs for random access. Stations STA1 and STA2 decrement their OBO counters by 3. Because the OBO counter of station STA1 reaches 0, station STA1 randomly selects one of the three RUs indicated by the trigger frame as the RU to be allocated for random access, and then attempts to transmit through the selected RU to the AP.

[0119] Figure 10 The specific format of the UORA parameter set element according to an embodiment of the present invention is shown.

[0120] As described above, a base station wireless communication terminal can use UORA parameter set elements to transmit parameters for UORA via signals. More specifically, the base station wireless communication terminal can use beacon frames or probe response frames to transmit UORA parameter set elements. UORA parameter set elements can include information necessary to obtain OCWmin and OCWmax. More specifically, UORA parameter set elements can include an element ID field, a length field, an element ID extension field, and an OCW range field, such as... Figure 10 As shown in the diagram. The Element ID field and the Element ID Extended field can indicate the values ​​used to identify the UORA parameter set element. Additionally, the Length field can indicate the length of the UORA parameter set element. The OCW Range field can include the information necessary to obtain OCWmin and OCWmax. More specifically, the OCW Range field can include the EOCWmin field and the EOCWmax field. The wireless communication terminal can obtain 2^EOCWmin-1 as OCWmin. Additionally, the wireless communication terminal can obtain 2^EOCWmax-1 as OCWmax.

[0121] The wireless communication terminal can set OCWmin and OCWmax based on the most recently received UORA parameter set elements. In this case, the wireless communication terminal can set OCWmin and OCWmax based on the most recently received UORA parameter set elements, regardless of the access class (AC) to be transmitted. More specifically, the wireless communication terminal can use information indicated by the most recently received UORA parameter set elements to set OCWmin and OCWmax, regardless of the access class (AC) to be transmitted.

[0122] For reference Figures 9 to 10As in the described embodiments, the fact that the wireless access terminal randomly accesses the frequency band indicated by the trigger frame and performs uplink transmission is referred to as uplink transmission-based random access. More specifically, uplink transmission-based random access may instruct the wireless communication terminal to perform uplink transmission using OFDMA in the frequency band indicated by the trigger frame.

[0123] The wireless communication terminal can select the PPDU to be used for transmission based on at least one of its transmission conditions and capabilities. For example, when the receiver reports that a DCM or an ER single-user (SU) payload can be received, the wireless communication terminal can send a 242-tone extended range (ER) SU PPDU to receive the PPDU. Alternatively, when the receiver reports that a UL HE MU PPDU can be received, the wireless communication terminal can send a UL HE MU PPDU to the wireless communication terminal that will receive the PPDU. Whether to receive an ER single-user (SU) payload can be determined by whether to receive a 106-tone ER SU PPDU. Furthermore, when the wireless communication terminal receives an HE ER PPDU or an HE SU PPDU using STBC, it can respond to the received PPDU with a PPDU including a control frame using the same format as the received PPDU.

[0124] Furthermore, the base station wireless communication terminal can respond to a trigger-based PPDU by using a PPDU format supported by the receiver to send a PPDU including a control frame. When the base station wireless communication terminal sends a trigger frame that is not of the MU RTS type, it can use a PPDU format supported by the receiver to send a PPDU including a trigger frame. When the wireless communication terminal receives a PPDU including a trigger frame that is not of the MU RTS type or a MAC frame including UMRS, it can respond to the corresponding PPDU by sending a trigger-based PPDU including a control frame.

[0125] When a wireless communication terminal receives a HE ERSU PPDU that includes a Fine Timing Measurement (FTM) frame or a HE SU PPDU that includes an FTM frame, the wireless communication terminal can send an ACK frame in response to the FTM frame using the same format as the received PPDU. In this case, when the wireless communication terminal receives a HE SU PPDU that includes an FTM frame after being associated with the transmitter and the most recently successfully transmitted PPDU is a HE ERSU PPDU, the wireless communication terminal can send a control frame to the HE ERSU PPDU.

[0126] When a wireless communication terminal responds to a HEERSU PPDU to send a control frame, the wireless communication terminal may use the HEERSU PPDU to send the control frame. If the most recently successfully transmitted PPDU after the wireless communication terminal has associated with the transmitter is not a HEERSU PPDU, the wireless communication terminal may use a non-efficient (HE)PPDU to send the control frame.

[0127] When a wireless communication terminal responds to a HE ER SU PPDU by sending a control frame, the wireless communication terminal may use a non-HT PPDU or a non-HT repeated PPDU to send the control frame. The wireless communication terminal may use a HE ER SU PPDU to send a control frame if the most recently successfully transmitted PPDU after the wireless communication terminal has associated with the transmitter is not a HE ER SU PPDU.

[0128] In subsequent TXOPs, the PPDU format may change between HE ER SU PPDU and non-HT PPDU. More specifically, the wireless communication terminal can send a HE ER SU PPDU in response to a non-HT PPDU. Alternatively, the wireless communication terminal can send a non-HT PPDU in response to a HE ER PPDU. The transmitter requesting the transmission of a control frame in response can set the duration of the TXOP based on the format of the response PPDU. Furthermore, when the wireless communication terminal receives an immediate ACK for the most recently transmitted PPDU, the wireless communication terminal can determine that the latest PPDU transmission was successful.

[0129] When multiple BSSs overlap, the communication efficiency of a wireless communication terminal may be reduced due to interference caused by transmissions in another BSS. In particular, when using a frequency band through a contention process, the wireless communication terminal may even be unable to secure a transmission opportunity due to interference from other wireless communication terminals. To address this issue, the wireless communication terminal can perform spatial multiplexing (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 "frame" is used in the following description unless otherwise stated, it is assumed to refer to a MAC frame.

[0130] In certain embodiments, access channel operations may include NAV setting and reset operations, CCA operations, and postponement 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 a BSS including the wireless communication terminal or from an OBSS. Additionally, the wireless communication terminal may adjust the transmission power of the PPDU to be transmitted based on the CCA threshold adjustment during SR operations.

[0131] 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, BSSs different from those within the BSS are referred to as inter-BSS. Frames transmitted from within the BSS are called intra-BSS frames, and frames transmitted from 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 intra-BSS PPDUs.

[0132] Specifically, the wireless communication terminal can apply a CCA threshold based on whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU while transmitting the received PPDU. In a particular embodiment, the CCA threshold can be applied simultaneously with the transmission of the payload of the received PPDU, based on whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU. Furthermore, the wireless communication terminal can receive the first PPDU and the 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 the CCA threshold based on whether the received PPDU is an inter-BSS PPDU or an intra-BSS PPDU while transmitting the received 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, the wireless communication terminal may also receive an inter-BSS PPDU while the transmission of the intra-BSS PPDU is not yet 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 completed. Specifically, the wireless communication terminal may not apply the CCA threshold corresponding to the inter-BSS PPDU until the transmission of the intra-BSS PPDU is 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. For ease of description, performing preamble detection (PD) using the CCA threshold corresponding to the inter-BSS PPDU can be referred to as SR operation based on OBSS PD.

[0133] This describes a method for identifying whether a PPDU received by a wireless communication terminal is an intra-BSS PPDU or an inter-BSS PPDU.

[0134] The wireless communication terminal can determine whether a PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color indicated by the signaling field of the PPDU. In this case, the BSS color is a BSS identifier. Additionally, the number of possible values ​​for a BSSID can be less than the number of possible values ​​for a BSSID. The base station wireless communication terminal determines the BSS color of the BSS operated by the base station wireless communication terminal. In this case, the base station wireless communication terminal can determine any one of 1 to 63 as the BSS color. The BSS colors of BSSs included in the same set of BSSIs may all be the same. Therefore, the base station wireless communication terminal can set the value of the BSS color such that the BSS colors of BSSs included in the same set of BSSIs are the same. The base station wireless communication terminal can use the HE operation element or the BSS color change announcement element to signal the BSS color of the BSS operated by the base station wireless communication terminal. Wireless communication terminals other than the base station wireless communication terminal can set the value of the BSS color received from the base station wireless communication terminal as the value of the BSS color field of the HE operation element. Additionally, when a base station wireless communication terminal changes the value of the BSS color operated by the base station wireless communication terminal, the base station wireless communication terminal can send the value of the BSS color to be changed by signaling information about the BSS color change. In this case, the information about the BSS color change can be a BSS color change notification element.

[0135] The wireless communication terminal can set the BSS color value received from the base station wireless communication terminal as the effective BSS color value. In this case, the effective BSS color can indicate the BSS color actually used by the wireless communication terminal. More specifically, the BSS color set by the wireless communication terminal to the value of the BSS color field of the HE-SIG-A field of the PPDU and the value of the BSS color field of the HE operation element can be referred to as the effective BSS color. Therefore, the wireless communication terminal can set the effective BSS color value to the value of the BSS color indicated by the PPDU sent by the wireless communication terminal. Specifically, the wireless communication terminal sets the effective BSS color value to the value of the BSS color field of the HE-SIG-A field of the PPDU sent by the wireless communication terminal. For example, the base station wireless communication terminal can set the effective BSS color value using the BSS_COLOR parameter of the TXVECTOR parameter and set the effective BSS color value in the BSS color field of the HE-SIG-A field of the PPDU. When the wireless communication terminal receives information about a BSS color change and reaches the BSS color change time point indicated by the information about the BSS color change, the wireless communication terminal can set the effective BSS color to the value of the BSS color indicated by the information about the BSS color change. In this context, the BSS color value indicated by information regarding BSS color changes can be the value indicated by the new BSS color subfield of the BSS color change notification element. The BSS color change time can be determined based on the Target Beacon Transmission Time (TBTT). Additionally, when a wireless communication terminal establishes an association with another wireless communication terminal, establishes a Tunnel Direct Link Establishment (TDLS) link, establishes a Direct Link Establishment (DLS) link, or becomes an IBSS member, the wireless communication terminal can set the value of the BSS color field in the HE-SIG-A field of the PPDU sent to the corresponding wireless communication terminal to the valid BSS color value. In the following description, the BSS color value of the BSS can refer to the valid BSS color.

[0136] A base station wireless communication terminal can stop performing SR operations based on OBSS PD of the receiving wireless communication terminal by setting the value of the BSS color indicated by the PPDU to 0. In a particular embodiment, when at least one of the intended receivers of the PPDU is not associated with the BSS operated by the base station wireless communication terminal, the base station wireless communication terminal can set the BSS color indicated by the corresponding PPDU to 0. Furthermore, when the intended receiver of the HE SU PPDU or HE ER SU PPDU is not associated with the BSS operated by the base station wireless communication terminal, the base station wireless communication terminal can set the BSS color indicated by the corresponding PPDU to 0.

[0137] When a wireless communication terminal receives a PPDU indicating a BSS color value from 1 to 63, it can perform a Service Response (SR) operation based on the OBSS PD. Conversely, when a wireless communication terminal receives a PPDU indicating a BSS color value of 0, it may not perform an SR operation based on the OBSS PD. More specifically, when a wireless communication terminal receives a PPDU indicating a BSS color value of 0, it may not determine whether the channel is idle based on the OBSS PD threshold. Furthermore, when a wireless communication terminal receives a PPDU indicating a BSS color value of 0, it may not discard the corresponding PPDU. Specifically, when a wireless communication terminal receives a HE SU PPDU or HE ER SU PPDU indicating a BSS color value of 0, it may not discard the corresponding PPDU. Through these embodiments, the base station wireless communication terminal can send PPDUs to wireless communication terminals not associated with the BSS operated by the base station communication terminal. Additionally, the wireless communication terminal can receive PPDUs from base station wireless communication terminals not associated with it.

[0138] When at least one of the intended receivers of a PPDU is not associated with a BSS operated by a base station wireless communication terminal, this could be a case where the intended receiver of the PPDU sent by the base station wireless communication terminal, the intended receiver of the A-MPDU included in the PPDU, or the intended receiver of the frame is not associated with the BSS operated by the base station wireless communication terminal. Additionally, as described above, the base station wireless communication terminal can use a trigger frame to trigger random access from a wireless communication terminal not associated with the base station wireless communication terminal. In this case, the base station wireless communication terminal can set the value of the BSS color indicated by the PPDU including the trigger frame to 0. In this case, refer to... Figures 11 to 13 Describe the operation of the wireless communication terminal.

[0139] Figure 11 This invention illustrates a method for determining whether a PPDU received by a wireless communication terminal is an intra-BSS PPDU or an inter-BSS PPDU.

[0140] As described above, the wireless communication terminal can determine whether a received PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the BSS color indicated by the signaling field of the PPDU. More specifically, the wireless communication terminal can determine whether the corresponding PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the value of the BSS color indicated by the PPDU received by the wireless communication terminal. The wireless communication terminal can determine the value of the BSS color indicated by the received PPDU based on the value indicated by the BSS color field of the HE-SIG-A field of the received PPDU. More specifically, the wireless communication terminal can determine the value of the BSS color indicated by the received PPDU based on the BSS_COLOR of the RXVECTOR.

[0141] Furthermore, the wireless communication terminal can determine whether a 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 transmitter address TA of the MAC header of a frame received by the wireless communication terminal is a BSSID of the BSS that includes the wireless communication terminal, or is included in a set of multiple BSSIDs that include the wireless communication terminal, the wireless communication terminal can identify the received frame as an intra-BSS frame.

[0142] Furthermore, the wireless communication terminal can determine whether a VHT PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on a portion of its AID field. More specifically, the wireless communication terminal can determine whether a VHT PPDU is an inter-BSS PPDU or an intra-BSS PPDU based on both the portion of its AID field and its group ID field. When the group ID field of a VHT PPDU received by the wireless communication terminal is 0 and the value of the portion of its AID field matches bits 39 to 47 of a BSSID included in a BSS that includes the wireless communication terminal, or in a set of multiple BSSIDs included in a BSS that includes the wireless communication terminal, the wireless communication terminal can identify the VHT PPDU as an intra-BSS PPDU. Additionally, if the group ID field of the VHT PPDU received by the wireless communication terminal is 0, and the value of a portion of the AID field does not match the value of bits from index 39 to index 47 in the BSSID included in the BSS of the wireless communication terminal or in the BSSID of a set of multiple BSSIDs included in the BSS of the wireless communication terminal (BSSID[39:47]), the wireless communication terminal can identify the VHT PPDU as an Inter-BSS PPDU.

[0143] When the group ID field of a VHT PPDU received by the wireless communication terminal is 63 and the values ​​of bits 5 to 8 of the partial AID field match the values ​​of the partial BSS colors of the BSS including the wireless communication terminal, the wireless communication terminal can identify the VHT PPDU as an intra-BSS PPDU. Alternatively, when the group ID field of a VHT PPDU received by the wireless communication terminal is 63 and the values ​​of bits from index 5 to index 8 of the partial AID field (partial AID[5:8]) do not match the values ​​of the partial BSS colors of the BSS including the wireless communication terminal, the wireless communication terminal can identify the corresponding VHT PPDU as an inter-BSS PPDU. A partial BSS color can be one of the four LSBs of the BSS color of the BSS. When the base station wireless communication terminal allows partial BSS-based intra-BSS PPDUs or inter-BSS PPDUs, the wireless communication terminal can determine whether the VHT PPDU received by the wireless communication terminal is an inter-BSS PPDU or an intra-BSS PPDU based on the partial BSS color. Base station wireless communication terminals can use the partial BSS color field of the HE operation element to indicate the identification of PPDUs within or between BSSs based on partial BSS colors.

[0144] When a frame received by a wireless communication terminal lacks a TA field and its RA field matches the Transmission Opportunity (TXOP) holder address of a BSS including the wireless communication terminal, the wireless communication terminal can identify the frame as an intra-BSS frame. In this case, the frame can be restricted to a control frame. Additionally, the TXOP holder can instruct the wireless communication terminal that acquires the TXOP through a contention process.

[0145] Additionally, when the UL / DL field of the HE-SIG-A field of a PPDU received by the base station wireless communication terminal indicates downlink transmission, the base station wireless communication terminal can identify the corresponding PPDU as an inter-BSS PPDU. In this case, the value of the UL / DL field can be 0.

[0146] In a particular embodiment, when a frame or PPDU received by a wireless communication terminal meets any of the following conditions, the wireless communication terminal may identify the frame as an intra-BSS frame or the PPDU as an intra-BSS PPDU.

[0147] - The value of the BSS color indicated by the PPDU including this frame is equal to the value of the BSS color including the BSS of the wireless communication terminal. In this case, the value of the BSS color including the BSS of the wireless communication terminal can be the value of the BSS color transmitted by the wireless communication terminal using a signal from the base station associated with the wireless communication terminal.

[0148] - When the individual / group bits of the RA field, TA field, or BSSID field of a frame are set to 0, the value of the corresponding field is equal to the BSSID of the BSS of the wireless communication terminal.

[0149] - When the base station wireless communication terminal associated with the wireless communication terminal is a member of multiple BSSID sets, and the individual / group bits of the RA field, TA field, or BSSID field of the frame are set to 0, the value of this field is equal to the BSSID of the BSS that includes the wireless communication terminal.

[0150] -PPDU is VHT PPDU, the group ID field of VHT PPDU is 0, and the value of part of the AID field is equal to the value of the bits from index 37 to index 47 of the BSSID of the BSS including the wireless communication terminal (BSSID[39:47]).

[0151] - The partial BSS color field of the HE operation element recently sent from the BSS including the wireless communication terminal is 1, the PPDU is VHT PPDU, the group ID field of the VHT PPDU is 63, and the value of the partial AID field of the PPDU from the bit with index 5 to the bit with index 8 (partial AID[5:8]) is equal to the BSS color of the partial BSS including the wireless communication terminal.

[0152] - This frame is a control frame without a TA field, and the RA field of this frame is equal to the address of the TXOP holder of the BSS of the wireless communication terminal.

[0153] In addition, when a frame or PPDU received by a wireless communication terminal meets any of the following conditions, the wireless communication terminal may identify the frame as an inter-BSS frame or the PPDU as an inter-BSS PPDU.

[0154] - The value of the BSS color indicated by the PPDU is not 0, and the value of the BSS color indicated by the PPDU is not equal to the value of the BSS color of the BSS including the wireless communication terminal. In this case, the value of the BSS color including the wireless communication terminal may be the value of the BSS color transmitted by the wireless communication terminal with a signal from the base station associated with the wireless communication terminal.

[0155] - When the Individual / Group bit of the BSSID field in a frame is set to 0, the value of the corresponding field is not equal to the BSSID of the BSS including the wireless communication terminal. In this case, the PPDU receiving the frame may not indicate the BSS color.

[0156] - When a frame does not include the BSSID field and the individual / group bits of the RA and TA fields of the frame are set to 0, the value of either field is not equal to the BSSID of the BSS of the wireless communication terminal.

[0157] - When the base station wireless communication terminal associated with the wireless communication terminal is a member of multiple BSSID sets, and the individual / group bits of the RA field, TA field, and BSSID field of the frame are set to 0, the value of any one of the fields is not equal to the BSSID of the BSS that includes the wireless communication terminal.

[0158] -PPDU is VHT PPDU, the group ID field of PPDU is 0, and the value of part of the AID field is not equal to the value of the bits from index 37 to index 47 of the BSSID of the BSS including the wireless communication terminal (BSSID[39:47]).

[0159] - The partial BSS color field of the HE operation element recently sent from the BSS including the wireless communication terminal is 1, the PPDU is VHT PPDU, the group ID field of the VHT PPDU is 63, and the value of the partial AID field of the PPDU with index 5 to the bit with index 8 (partial AID[5:8]) is different from the BSS color of the partial BSS including the wireless communication terminal.

[0160] - The UL / DL field of the HE-SIG-A field of the PPDU received by the base station wireless communication terminal indicates downlink transmission.

[0161] In the above embodiments, the wireless communication terminal can prioritize a first determination based on the MAC address—whether a frame or PPDU is transmitted between or within a BSS—over a second determination based on the BSS color indicated by the PPDU. As described above, the PPDU can indicate the BSS color through the BSS color in the HE-SIG-A field. Additionally, the PPDU can indicate the BSS color through the AID field in the Group ID field. Furthermore, when a frame or PPDU satisfies both the intra-BSS frame or PPDU condition and the inter-BSS frame or PPDU condition, the wireless communication terminal can identify the corresponding frame or PPDU as an inter-BSS frame or PPDU. Conversely, when a frame or PPDU neither satisfies the intra-BSS frame or PPDU condition nor the inter-BSS frame or PPDU condition, the wireless communication terminal may choose not to identify the corresponding frame or PPDU as either an inter-BSS frame or PPDU or an intra-BSS frame or PPDU.

[0162] A wireless communication terminal can maintain a Network Allocation Vector (NAV), which is an indicator that the wireless communication terminal has not initiated continued transmission on the wireless medium. More specifically, the wireless communication terminal can set the NAV based on duration information indicated by the duration / ID field of the MAC header. Alternatively, the wireless communication terminal can set the NAV based on duration information indicated by the TXOP duration field of the HE-SIG-A of the PPDU. In this case, when the TXOP duration field of the HE-SIG-A of the PPDU indicates duration information, the wireless communication terminal can set the NAV based on the TXOP duration field of the HE-SIG-A of the PPDU. For example, when all bits of the TXOP duration field of the HE-SIG-A of the PPDU are set to 1, the wireless communication terminal may not set the NAV based on the TXOP duration field of the HE-SIG-A of the PPDU. In these embodiments, when the value of TXOP indicated by the duration information obtained by the wireless communication terminal from the duration / ID field of the MAC header or the TXOP duration field of the HE-SIG-A of the PPDU is greater than the current NAV, the wireless communication terminal can set the NAV based on the obtained duration information.

[0163] Wireless communication terminals can manage NAVs differently depending on whether frames or PPDUs are transmitted from within the BSS. This allows wireless communication terminals to improve the efficiency of using the wireless medium when an OBSS is present. More specifically, a wireless communication terminal can maintain two NAVs: a BSS-based intra-BSS NAV set based on intra-BSS PPDUs or frames, and a basic NAV set based on inter-BSS PPDUs or frames. In this case, the wireless communication terminal can set the basic NAV based on PPDUs or frames that cannot be identified as inter-BSS PPDUs or frames or intra-BSS PPDUs or frames. Detailed operations related to NAV settings for wireless communication terminals will be described.

[0164] When a frame or a PPDU including the corresponding frame does not request an immediate response, the wireless communication terminal can set the NAV within the BSS based on the duration / ID field of the MAC header of the corresponding frame or the TXOP duration field of the corresponding PPDU. Additionally, when the wireless communication terminal does not send an immediate response even when the frame or a PPDU including the corresponding frame requests one, the wireless communication terminal can set the NAV within the BSS based on the duration / ID field of the MAC header of the corresponding frame or the TXOP duration field of the corresponding PPDU. Furthermore, when the wireless communication terminal is the TXOP holder, it can set the NAV only based on frames that the wireless communication terminal did not request.

[0165] Additionally, when the wireless communication terminal does not obtain duration information from the duration / ID field of the frame included in the PPDU, it can set the NAV based on the HE-SIG-A TXOP duration field of the PPDU. When the wireless communication terminal obtains duration information from both the duration / ID field of the frame included in the PPDU and the TXOP duration field of the HE-SIG-A of the PPDU, it can ignore the duration information obtained from the TXOP duration field of the corresponding PPDU's HE-SIG-A. In this case, the wireless communication terminal can set the NAV based on the duration information obtained from the duration / ID field of the corresponding frame.

[0166] In addition, when the wireless communication terminal does not trigger the PPDU received by the wireless communication terminal, the wireless communication terminal can be allowed to set the NAV based on the HE-SIG-A TXOP duration field of the PPDU.

[0167] According to the above embodiments, when a wireless communication terminal sends a trigger-based PPDU, the wireless communication terminal can set the BSS color indicated by the trigger-based PPDU based on the BSS color of the PPDU including the trigger frame requesting the trigger-based PPDU. More specifically, the wireless communication terminal can set the BSS color field of the HE-SIG-A field of the trigger-based PPDU based on the BSS color of the PPDU including the trigger frame requesting the trigger-based PPDU. When the PPDU including the trigger frame requesting the trigger-based PPDU does not indicate a BSS color, the wireless communication terminal can use the value of the BSS color field of the most recently received HE operation element to set the BSS color field of the HE-SIG-A field of the trigger-based PPDU. Furthermore, when the PPDU including the trigger frame requesting the trigger-based PPDU reaches a BSS color change time point but does not indicate a BSS color, the wireless communication terminal can use the new BSS color field value of the most recently received BSS color change notification element to set the BSS color field of the HE-SIG-A field of the trigger-based PPDU. In this case, the BSS color change time point can be the time point in time when a predetermined number of TBTTs have elapsed since the base station wireless communication terminal changed the BSS color change notification element.

[0168] Furthermore, as described above, when the intended receiver of the trigger frame is not associated with the base station wireless communication terminal that sent the trigger frame, the base station wireless communication terminal can set the value of the BSS color indicated by the PPDU including the trigger frame to 0. In this case, because the value of the BSS color indicated by the PPDU is 0, when the wireless communication terminal receiving the PPDU including the trigger frame cannot decode the frame included in the PPDU, the wireless communication terminal cannot determine whether the corresponding PPDU is an intra-BSS PPDU or an inter-BSS PPDU. Therefore, according to the above embodiment, the wireless communication terminal receiving the PPDU including the trigger frame can set the basic NAV based on the TXOP duration field of the corresponding PPDU. In this case, when the PPDU is transmitted with a modulation method not supported by the wireless communication terminal, the wireless communication terminal may not be able to decode the frame included in the corresponding PPDU. More specifically, the PPDU can be transmitted with MCS, DCM, and compilation types not supported by the wireless communication terminal. In addition, frame decoding may fail after the wireless communication terminal receives the preamble of the PPDU. Furthermore, when the PPDU is a trigger-based PPDU, because the wireless communication terminal cannot determine the composition of the PPDU and PSDU, it may not be able to receive the frame included in the PPDU.

[0169] In this scenario, when a PPDU is sent from a base station wireless communication terminal associated with the wireless communication terminal, the wireless communication terminal will update the basic NAV even if the NAV within the BSS needs to be updated. When the basic NAV is set, even if the base station wireless communication terminal associated with the corresponding wireless communication terminal requests an immediate response, the wireless communication terminal may not send an immediate response to the base station wireless communication terminal. When the base station wireless communication terminal associated with the wireless communication terminal requests an immediate response, the corresponding wireless communication terminal may ignore the NAV within the BSS and send an immediate response. However, this is because even if the base station wireless communication terminal associated with the wireless communication terminal requests an immediate response, the wireless communication terminal cannot ignore the basic NAV and send an immediate response.

[0170] exist Figure 11 In one embodiment, the AP operating the first BSS BSS1 sends a trigger frame that triggers random access to a station not associated with that AP. In this case, the AP sets the BSS color field of HE-SIG-A in the PPDU including the trigger frame to 0. The first station STA1 included in the first BSS BSS1 configures its basic NAV based on the PPDU including the trigger frame.

[0171] Wireless communication terminals not included in the first BSS BSS1 set the BSS color to 0 to transmit trigger-based PPDUs. The second station STA2 included in the first BSS BSS1 sets the basic NAV based on the trigger-based PPDU.

[0172] Subsequently, the AP operating the first BSS (BSS1) sends a trigger frame to initiate transmissions at the first station (STA1) and the second station (STA2). Since the basic NAV determines that the channel used for transmission is busy, the first station (STA1) and the second station (STA2) do not send trigger-based PPDUs.

[0173] Figure 12 This illustrates a power-saving operation of a wireless communication terminal according to an embodiment of the present invention.

[0174] Although PPDUs are transmitted between other wireless communication terminals in a BSS that includes the wireless communication terminal, the wireless communication terminal may determine that it cannot receive or transmit PPDUs. In this case, the wireless communication terminal may enter a sleep state. The sleep state can indicate that the wireless communication terminal disables some functions to reduce power consumption. Specifically, when the wireless communication terminal receives a PPDU within the BSS that it is not the intended receiver for, it can remain in a sleep state while transmitting the corresponding PPDU. This is because when the wireless communication terminal receives a PPDU within the BSS and it is not the intended receiver for that PPDU, it cannot receive or transmit PPDUs while transmitting the corresponding PPDU. In a particular embodiment, a wireless communication terminal that is not a base station wireless communication terminal can determine that it is not the intended receiver for an uplink (UL) PPDU. Additionally, when a wireless communication terminal that is not a base station wireless communication terminal receives a downlink (DL) PPDU and the receiver identifier indicated by the signaling field of the corresponding PPDU does not indicate the wireless communication terminal, the wireless communication terminal can determine that it is not the intended receiver for the PPDU. For example, when the HE-SIG-B field of the HE MU PPDU does not indicate the associated ID (AID) of the wireless communication terminal, the wireless communication terminal can determine that it is not the intended receiver of the corresponding PPDU. This operation of the wireless communication terminal can be called PPDU in-system power saving.

[0175] A more detailed description of the power-saving operation within the PPDU is provided. When a wireless communication terminal other than the base station wireless communication terminal receives a PPDU that meets any of the following conditions, the wireless communication terminal other than the base station wireless communication terminal may remain in sleep mode until the transmission of the corresponding PPDU is terminated.

[0176] -PPDU is HE MU PPDU. The BSS color field of the HE-SIG-A field of the PPDU is equal to the BSS color of the BSS including the wireless communication terminal. The UL / DL field of the HE-SIG-A field of the PPDU indicates downlink transmission, and the HE-SIG-B of the PPDU does not include the STA ID field indicating the wireless communication terminal or the broadcast ID indicating multiple wireless communication terminals including the wireless communication terminal.

[0177] - The PPDU is HE MU PPDU, HE SU PPDU, or HE ER SU PPDU. The BSS color field of the HE-SIG-A field of the PPDU is equal to the BSS color of the BSS of the wireless communication terminal, and the UL / DL field of the HE-SIG-A field of the PPDU indicates the uplink transmission.

[0178] - The PPDU is HE MU PPDU, HE SU PPDU, or HE ER SU PPDU. The BSS color field of the HE-SIG-A field of the PPDU is equal to the BSS color of the BSS of the wireless communication terminal. The UL / DL field of the HE-SIG-A field of the PPDU indicates uplink transmission and the PPDU is transmitted at a rate not supported by the wireless communication terminal.

[0179] -PPDU is a trigger-based PPDU, and the BSS color field of the HE-SIG-A field of the PPDU is equal to the BSS color of the BSS of the wireless communication terminal.

[0180] - The PPDU is a VHT PPDU, and the value of the AID field of the PPDU is equal to the value of the bits from index 37 to index 47 of the BSSID of the BSS of the wireless communication terminal (BSSID[39:47]), and the value of the group ID field of the PPDU is 0.

[0181] - The MPDU included in the PPDU includes an RA field, a TA field, or a BSSID field, which indicates the BSSID of the BSS of the wireless communication terminal or any one of a set of BSSIDs of the BSS of the wireless communication terminal. The RA field does not indicate the MAC address of the wireless communication terminal.

[0182] The wireless communication terminal can set the value indicated by the UL / DL field of the HE-SIG-A field of the transmitted PPDU to the UL_FLAG of the downlink or TXVECTOR. Additionally, the wireless communication terminal can set the value indicated by the BSS color field of the HE-SIG-A field of the transmitted PPDU to the BSS_COLOR of the TXVECTOR.

[0183] The wireless communication terminal can determine the value indicated by the UL / DL field of the HE-SIG-A field of the received PPDU based on the UL_FLAG of the RXVECTOR. The wireless communication terminal can determine the value indicated by the BSS color field of the HE-SIG-A field of the received PPDU based on the BSS_COLOR of the RXVECTOR. The wireless communication terminal can determine whether to transmit the PPDU at a rate not supported by the wireless communication terminal based on whether the PHY-RXEND.indication(UnsupportedRate) primitive is received in the MAC layer.

[0184] exist Figure 12 In one embodiment, the AP operating the first BSS BSS1 sends a trigger frame that triggers random access from a station not associated with the AP. In this case, the AP sets the BSS color field of HE-SIG-A in the PPDU including the trigger frame to 0. Wireless communication terminals not included in the first BSS BSS1 set their BSS color to 0 to send trigger-based PPDUs. Because the BSS color value indicated by the trigger-based PPDU is 0, the first station STA1 included in the first BSS BSS1 may not perform in-BSS power-saving operations after decoding the signaling field of the PPDU. When the first station STA1 decodes the MAC header of the trigger-based PPDU, the first station STA1 may remain dormant until the transmission of the trigger-based PPDU is terminated. When the PPDU indicates a BSS color value of 0 in this way, although the wireless communication terminal can perform in-BSS power-saving operations, the wireless communication terminal may not be able to determine that the received PPDU is in-BSS and therefore may not be able to perform in-BSS power-saving operations.

[0185] Figure 13 This illustrates the operation of UL MU transmission performed by a wireless communication terminal according to an embodiment of the present invention.

[0186] As described above, when transmitting intra-BSS PPDUs simultaneously with inter-BSS PPDUs, the wireless communication terminal can perform CCA using a PD threshold level with a value equal to or greater than the used PD threshold level. In this case, the PD threshold used by the wireless communication terminal can be referred to as the OBSS PD threshold. This increases the likelihood of channel idleness compared to transmitting intra-BSS PPDUs simultaneously with inter-BSS PPDUs. However, when the BSS color value indicated by the PPDU is 0, the wireless communication terminal cannot perform SR operation based on the OBSS PD.

[0187] exist Figure 13In one embodiment, the AP operating the first BSS (BSS1) sends a trigger frame that triggers random access from a station not associated with that AP. In this case, the AP sets the BSS color field of HE-SIG-A of the PPDU including the trigger frame to 0. The first station STA1, included in the second BSS (BSS2), cannot recognize the PPDU including the trigger frame as an inter-BSS PDDU until the trigger frame is decoded. Therefore, the first station STA1 can determine whether the channel is idle after decoding the trigger frame by using the OBSS PD threshold. Figure 13 In one embodiment, because the first station STA1 uses an OBSS PD threshold greater than the normal PD threshold after decoding the trigger frame, the first station STA1 determines that the previously identified busy channel is idle.

[0188] Wireless communication terminals not included in the first BSS (BSS1) set their BSS color to 0 to transmit trigger-based PPDUs. Because the BSS color value indicated by the trigger-based PPDU is 0, the first station (STA1) cannot identify whether the trigger-based PPDU is an inter-BSS PPDU. Furthermore, because the first station (STA1) cannot decode the payload of the trigger-based PPDU, it cannot perform SR operations based on the OBSS PD when transmitting the trigger-based PPDU.

[0189] To solve the reference Figures 11 to 13 The problem described can be addressed by considering the operation of the wireless communication terminal, which will be described below.

[0190] Figure 14 This invention illustrates a method for setting the BSS color of a corresponding PPDU when a base station wireless communication terminal sends a PPDU including a trigger frame, the trigger frame triggering transmissions by wireless communication terminals not associated with the base station wireless communication terminal and wireless communication terminals associated with the base station wireless communication terminal.

[0191] The base station wireless communication terminal can set the BSS color value indicated by the PPDU including trigger information to a value other than 0 for the BSS color of the BSS operated by the base station wireless communication terminal. Specifically, when the trigger information triggers a transmission of a wireless communication terminal not included in the BSS operated by the base station wireless communication terminal, the base station wireless communication terminal can set the BSS color value indicated by the PPDU including trigger information to the BSS color of the BSS operated by the base station wireless communication terminal. The trigger information for triggering the transmission of a wireless communication terminal not included in the BSS operated by the base station wireless communication terminal can be a trigger frame for triggering random access of a wireless communication terminal not included in the BSS operated by the base station wireless communication terminal. Additionally, the PPDU including trigger information can be a PPDU including a trigger frame for triggering the transmission of a wireless communication terminal not included in the BSS operated by the base station wireless communication terminal and a frame sent to a wireless communication terminal included in the BSS operated by the base station wireless communication terminal. Alternatively, the PPDU including trigger information can be a PPDU including a trigger frame for triggering the transmission of a wireless communication terminal not included in the BSS operated by the base station wireless communication terminal and a frame sent to a wireless communication terminal included in the BSS operated by the base station wireless device. Additionally, the PPDU including trigger information can be a PPDU including a trigger frame, which is used to trigger transmissions of wireless communication terminals not included in the BSS operated by the base station wireless communication terminal as well as transmissions of wireless communication terminals included in the BSS operated by the base station wireless communication terminal.

[0192] exist Figure 14 In this embodiment, the AP operating the first BSS BSS1 sends a PPDU including a trigger frame. In this case, the base station wireless communication terminal sets the AID field value of the user information field of the trigger frame to 12 and 2045 to perform the transmission of the first station AID 12 associated with the AP and trigger random access of wireless communication terminals not associated with the AP. Therefore, the AP sets the BSS color value indicated by the PPDU to the BSS color value of the first BSS BSS1.

[0193] Through these embodiments, the wireless communication terminal can solve the problem caused by uncertainty regarding whether the PPDU received by the wireless communication terminal is an intra-BSS PPDU or an inter-BSS PPDU. Furthermore, the wireless communication terminal can apply these embodiments to HE SUPPDU or HE ER SU PPDU.

[0194] Figure 15 This invention illustrates a method for setting the BSS color of a corresponding PPDU when a base station wireless communication terminal sends a PPDU to a wireless communication terminal included in a set of multiple BSSIDs comprising a BSS operated by the base station wireless communication terminal.

[0195] As described above, when a base station wireless communication terminal sends a PPDU including trigger information for triggering transmissions by wireless communication terminals included in a set of multiple BSSIDs comprising a BSS operated by the base station wireless communication terminal, the base station wireless communication terminal can set the value of the BSS color indicated by the PPDU to 0. Additionally, a wireless communication terminal that includes the trigger information and receives a PPDU indicating a BSS color value of 0 can set the value of the BSS color based on the trigger-based PPDU to 0 to send the trigger-based PPDU to the base station wireless communication terminal. In this embodiment, similar to the reference... Figures 11 to 13 The issues described may arise where wireless communication terminals cannot identify whether a PPDU is an inter-BSS PPDU or an intra-BSS PPDU.

[0196] When the intended receiver of a PPDU includes wireless communication terminals included in a BSS operated by a base station wireless communication terminal and wireless communication terminals of BSSs corresponding to multiple sets of BSSIDs including BSSs operated by the base station wireless communication terminal, the base station wireless communication terminal may set the value of the BSS color indicated by the PPDU to the value of the BSS color of the BSS operated by the base station wireless communication terminal. More specifically, when the base station wireless communication terminal sends a PPDU including trigger information for triggering transmissions of wireless communication terminals included in multiple sets of BSSIDs including BSSs operated by the base station wireless communication terminal, the base station wireless communication terminal may set the value of the BSS color indicated by the PPDU to the value of the BSS color of the BSS operated by the base station wireless communication terminal.

[0197] Additionally, the wireless communication terminal can set the BSS color value indicated by the trigger-based PPDU to a value other than 0. In the above embodiment, the wireless communication terminal can set the BSS color value indicated by the trigger-based PPDU to the value of the BSS color indicated by the PPDU containing trigger information. Furthermore, when the PPDU received by the wireless communication terminal includes trigger information and the value of the BSS color indicated by the PPDU is 0, the wireless communication terminal can set the BSS color value indicated by the trigger-based PPDU to the BSS value of the BSS color operated by the base station wireless communication terminal that sent the trigger information. The wireless communication terminal can send a trigger-based PPDU as a response to the PPDU containing trigger information. In this case, the wireless communication terminal can obtain the BSS color value of the BSS operated by the base station wireless communication terminal from the HE operation element previously sent by the base station wireless communication terminal. Additionally, the base station wireless communication terminal can obtain the BSS color value of the BSS operated by the base station wireless communication terminal from the trigger frame. (Refer to...) Figure 16 This will be described in more detail.

[0198] exist Figure 15 In one embodiment, the AP operating the first BSS (BSS1) sends a PPDU including a trigger frame. In this case, the trigger frame triggers random access for stations not included in the first BSS (BSS1), and the base station wireless communication terminal sets the value of the BSS color indicated by the PPDU including the trigger frame to 0. Stations sending trigger-based PPDUs based on the trigger frame set the value of the BSS color indicated by the trigger-based PPDU to the BSS color of the first BSS (BSS1) to send the trigger-based PPDU to the AP.

[0199] Before a wireless communication terminal obtains UORA parameter set elements from a base station wireless communication terminal, it can attempt random access based on a trigger frame sent by the base station wireless communication terminal. Specifically, when a trigger frame triggers random access from a wireless communication terminal not associated with the base station wireless communication terminal, the unassociated wireless communication terminal can attempt random access to the base station wireless communication terminal before obtaining UORA parameter set elements from it. In this case, the unassociated wireless communication terminal can attempt random access using a predetermined default UORA parameter set element. Similarly, the PPDU including the trigger frame may not indicate the value of the BSS color of the BSS in which the PPDU was sent, and the wireless communication terminal may not obtain the HE operation element from the base station wireless communication terminal that sent the trigger frame. More specifically, the PPDU including the trigger frame can be a non-HE PPDU. Furthermore, the value of the BSS color indicated by the PPDU including the trigger frame can be 0. Therefore, the base station wireless communication terminal can signal the BSS color of the BSS operated by the base station wireless communication terminal via the trigger frame. In this way, the wireless communication terminal sending the trigger-based PPDU cannot obtain the BSS color of the BSS operated by the base station wireless communication terminal sending the trigger frame, thereby preventing the failure to set the value of the BSS color indicated by the trigger-based PPDU. (See reference...) Figure 16 This will be described.

[0200] Figure 16 The format of the user information field in the trigger frame according to an embodiment of the present invention is shown.

[0201] The trigger frame may include a field indicating the value of the BSS color of the BSS operated by the base station wireless communication terminal that sent the trigger frame. More specifically, the public information field of the trigger frame may include a field indicating the value of the BSS color of the BSS operated by the base station wireless communication terminal that sent the trigger frame. For ease of description, the field indicating the value of the BSS color is referred to as the BSS color field. More specifically, the public information field of the trigger frame may optionally include the BSS color field used for sending the trigger frame. According to a particular embodiment, when the trigger type of the trigger frame is a predefined type, the public information field may optionally include the BSS color field used for sending the trigger frame. In this case, the predetermined trigger type may indicate a trigger frame that triggers random access by a wireless communication terminal not associated with the base station wireless communication terminal that sent the trigger frame.

[0202] In another specific embodiment, the user information field of the trigger frame may include a BSS color field for transmitting the trigger frame. More specifically, the user information field of the trigger frame may optionally include a BSS color field for transmitting the trigger frame. For example, when the user information field indicates a wireless communication terminal not associated with the base station wireless communication terminal transmitting the trigger frame, the user information field may include a BSS color field for transmitting the trigger frame. In this case, the user information field may include a BSS color field for transmitting the trigger frame instead of an SS allocation field. In this case, the wireless communication terminal may assume that the SS allocation field indicates a predetermined value. For example, the wireless communication terminal may assume that the SS allocation field indicates that both STARTING_SS_NUM and NUM_SS are 1.

[0203] Figure 16 (a) illustrates the specific format of the user information field when it is associated with a base station wireless communication terminal that sends the trigger frame. Additionally, Figure 16 (b) illustrates a specific format of a user information field, including a BSS color field, when the user information field is not associated with the base station wireless communication terminal that sends the trigger frame, in a particular embodiment. In this case, the BSS color field is the BSS color field used to send the trigger frame.

[0204] In another specific embodiment, when the user information field indicates a wireless communication terminal not associated with the base station wireless communication terminal sending the trigger frame, the user information field may further include the BSS color field of the trigger frame. In this case, the length of the user information field indicating a wireless communication terminal not associated with the base station wireless communication terminal sending the trigger frame is different from the length of the user information field indicating an association between the wireless communication terminal and the base station wireless communication terminal sending the trigger frame. However, in the trigger frame, when the user information field indicating that the wireless communication terminal is not associated with the base station wireless communication terminal sending the trigger frame is located after another user information field and the wireless communication terminal has a user information field indicating the wireless communication terminal, it may no longer be decoded. Therefore, even if the trigger frame includes user information fields of different lengths, the user information field indicating the wireless communication terminal can still be found.

[0205] Furthermore, the base station wireless communication terminal can obtain the BSS color value of the BSS operated by the base station wireless communication terminal from the trigger frame. More specifically, the wireless communication terminal can obtain the BSS color value of the BSS operated by the base station wireless communication terminal from the BSS color field included in the trigger frame.

[0206] In another specific embodiment, when a base station wireless communication terminal triggers a transmission from a wireless communication terminal not associated with it using a trigger frame, the wireless communication terminal can only send a trigger-based PPDU if it receives the HE operation element sent by the base station wireless communication terminal. (See also...) Figure 17 This will be described.

[0207] Figure 17 A method is shown in which, when a wireless communication terminal according to an embodiment of the invention sends a trigger-based PPDU to a base station wireless communication terminal not associated with the wireless communication terminal, the wireless communication terminal sets a value of the BSS color indicated by the trigger-based PPDU.

[0208] Specifically, when the wireless communication terminal is not associated with the base station wireless communication terminal that sent the trigger frame, the wireless communication terminal can attempt random access to the base station wireless communication terminal based on uplink transmission based on whether it has obtained the HE operation element from the base station wireless communication terminal. Specifically, when the wireless communication terminal is not associated with the base station wireless communication terminal that sent the trigger frame and the wireless communication terminal has obtained the HE operation element from the base station wireless communication terminal, the wireless communication terminal can attempt random access to the base station wireless communication terminal based on uplink transmission based on the trigger frame. In this case, the wireless communication terminal can set the value of the signaling field of the trigger-based PPDU to indicate the value of the BSS color field of the HE operation element obtained from the trigger-based PPDU. Furthermore, when the wireless communication terminal is not associated with the base station wireless communication terminal that sent the trigger frame and the wireless communication terminal has not obtained the HE operation element from the base station wireless communication terminal, the wireless communication terminal can choose not to perform random access to the base station wireless communication terminal based on uplink transmission based on the trigger frame. However, when the wireless communication terminal is not associated with the base station wireless communication terminal that sends the trigger frame and the wireless communication terminal receives a PPDU that includes the trigger frame and a signaling field indicating the BSS color, the wireless communication terminal can perform random access to the base station wireless communication terminal based on the uplink transmission even when no HE operation element is obtained.

[0209] exist Figure 17 In one embodiment, the AP sends a trigger frame that triggers random access to a station not associated with the AP. In this case, a wireless communication terminal receiving a HE operation element from the AP in a station not associated with the AP performs random access based on uplink transmission according to the trigger frame. Additionally, the wireless communication terminal can set the value of the BSS color field of the HE-SIG-A field of the triggered PPDU to the value of the BSS color field of the HE operation element obtained from the AP.

[0210] Furthermore, the wireless communication terminal can set the value of the signaling field based on the triggered PPDU, such that the triggered PPDU indicates the value of the BSS color field of the HE operation element corresponding to the valid BSS color operated by the base station wireless communication terminal. Specifically, after the BSS color change time point, the wireless communication terminal can set the value of the signaling field based on the triggered PPDU, such that the triggered PPDU indicates the value of the BSS color transmitted by the base station wireless communication terminal using the signal through the BSS color change information.

[0211] In the above embodiments, the base station wireless communication terminal may correspond to multiple BSSID sets. In this case, the wireless communication terminal can receive HE operation elements from the base station wireless communication terminal to obtain HE operation elements from the base station wireless communication terminal with reference BSSID, and consider HE operation elements from the base station wireless communication terminal with reference BSSID in the same manner as the HE operation elements obtained from the base station wireless communication terminal.

[0212] In another specific embodiment, when a base station wireless communication terminal triggers a transmission from a wireless communication terminal not associated with the base station wireless communication terminal using a trigger frame, the wireless communication terminal may only send a PPDU indicating the value of the BSS color. In this case, the PPDU indicating the value of the BSS color may be an HE PPDU. In this case, the transmission from the wireless communication terminal not associated with the base station wireless communication terminal may indicate random access based on uplink transmission.

[0213] As mentioned above, the value of the BSS color can be indicated by using a portion of the AID field of the VHT SU PPDU. (Refer to...) Figures 18 to 19 This will be described.

[0214] Figure 18 This invention illustrates a method for setting the TXVECTOR parameters GROUP_ID and PARTIAL_AID of a VHT SU PPDU in a wireless communication terminal according to an embodiment of the present invention.

[0215] Figure 18 The table illustrates the GROUP_IP and PARTIAL_AID setting methods for each condition. In this case, [b:c] represents the value from bit index b to bit index c. Additionally, bit n represents bit index n. Therefore, bit 0 represents the individual / group bit, and bit 47 represents the last bit of the partial AID field. Furthermore, bit position b can be scaled to 2^0, and bit position c can be scaled to 2^(cb). The base station wireless communication terminal may not assign an AID value with a PARTIAL_AID value of 0 to the wireless communication terminal.

[0216] A base station wireless communication terminal can use a portion of the AID field value to indicate the BSS color value of the BSS operated by the base station wireless communication terminal. More specifically, the base station wireless communication terminal can set a portion of the AID field value using a subset of bits of the BSS color value of the BSS operated by the base station wireless communication terminal. More specifically, the base station wireless communication terminal can set a portion of the AID field value using the following equation.

[0217] AID[5:8]=bin[(BCB[0:3]-(BSSID[44:47]XOR BSSID[40:43]))mod 2^4,4]

[0218] BCB[0:3] can represent the values ​​(4 LSBs) from bit index 0 to bit index 3 of the BSS color. Additionally, bin[x, 4] can represent the decimal value x as a 4-bit binary vector. As described above, the base station wireless communication terminal can set a portion of the BSS color field of the HE operation element to 1, and then use some bits of the BSS color value to set a portion of the AID field value. The wireless communication terminal can use the value of the portion AID field to determine whether the PPDU received by the wireless communication terminal is an inter-BSS PPDU or an intra-BSS PPDU, according to the aforementioned method for determining inter-BSS PPDUs and intra-BSS PPDUs. Specifically, when the group ID field value is 63 and the portion AID field value is not 0, the wireless communication terminal can use the value of the portion AID field to determine whether the PPDU received by the wireless communication terminal is an inter-BSS PPDU or an intra-BSS PPDU.

[0219] Figure 19 It is a view that determines whether a VHT PPDU received by a wireless communication terminal according to an embodiment of the present invention is an inter-BSS PPDU or an intra-BSS PPDU by using the value of a portion of the AID field of the signaling field of the VHT PPDU received by the wireless communication terminal.

[0220] Reference Figure 18 In the described embodiment, when the BSS color value is 48 (b110000) or 16 (b010000), four LSBs of a portion of the AID field of the PPDU are set to 0. Additionally, when the base station wireless communication terminal sends a VHT PPDU to a wireless communication terminal not associated with it, the base station wireless communication terminal sets the group ID field to 63 and sets four LSBs of a portion of the AID field to 0. A wireless communication terminal included in a BSS with a BSS color value of 48 (b110000) or 16 (b010000) and not associated with the base station wireless communication terminal can determine that the PPDU is an intra-BSS PPDU, even though the PPDU is an inter-BSS PPDU. Figure 19In this embodiment, the value of a portion of the BSS color of the first BSS BSS1 is 0. Therefore, when an AP other than the AP operating the first BSS BSS1 sends a VHT PPDU by setting the value of the group ID field of the VHT PPDU to 63 and setting four LSBs of a portion of the AID field to 0, the station included in the first BSS BSS1 can identify the VHT PPDU as an in-BSS PPDU. Therefore, the station included in the first BSS BSS1 can perform CCA by applying a PD threshold other than the OBSS PD threshold to the corresponding VHT PPDU. Additionally, when the value of the BSS color of the BSS operated by the base station wireless communication terminal is 48 (b110000) or 16 (b010000), even when the base station wireless communication terminal sends the VHT PPDU to a wireless communication terminal associated with the wireless base station, the base station wireless communication terminal sets four LSBs of a portion of the AID field of the VHT PPDU to 0. Therefore, the wireless communication terminal capable of performing SR operations may be unable to perform OBSS PD-based SR operations based on the portion of the AID field of the VHT PPDU.

[0221] Therefore, when the value of the group ID field of the VHT PPDU received by the wireless communication terminal is 63 and the value of the partial AID field is not 0, it can be determined whether the four LSBs of the partial AID field are equal to the value of the BSS color of the BSS including the wireless communication terminal. If the value of the group ID field of the VHT PPDU received by the wireless communication terminal is 63, the value of the partial AID field is not 0, and the four LSBs of the partial AID field are equal to the value of the BSS color of the BSS including the wireless communication terminal, then the wireless communication terminal can identify the VHT PPDU as an in-BSS PPDU. In a specific embodiment, when the partial BSS color field of the most recently operated element indicates that a partial BSS color is available, the wireless communication terminal can determine whether the four LSBs of the partial AID field are equal to the value of the BSS color of the BSS including the wireless communication terminal.

[0222] Reference Figures 20 to 21 This describes a method for setting the value of the TXOP duration field of a PPDU via a wireless communication terminal.

[0223] Figure 20 This illustrates the setting of the TXOP duration field of a PPDU in a wireless communication terminal according to an embodiment of the present invention.

[0224] As described above, the wireless communication terminal can set the NAV based on the duration information indicated by the TXOP duration field of the HE-SIG-A of the PPDU. In this case, when the TXOP duration field of the HE-SIG-A of the PPDU indicates duration information, the wireless communication terminal can set the NAV based on the TXOP duration field of the HE-SIG-A of the PPDU. For example, when all bits of the TXOP duration field of the HE-SIG-A of the PPDU are set to 1, the wireless communication terminal can set the NAV without using the TXOP duration field of the HE-SIG-A of the PPDU. In a specific embodiment, when the wireless communication terminal sends a PPDU including a PS polling frame, the wireless communication terminal can set the value of the TOXP duration field so that the TOXP duration field does not indicate duration information. Additionally, when the TXOP duration field of the request response PPDU does not indicate duration information, the wireless communication terminal, as the TXOP responder, can set the value of the TOXP duration field so that the TOXP duration field does not indicate duration information. Additionally, when the request response PPDU does not include the TXOP duration field, the wireless communication terminal acting as the TXOP responder can set the value of the TOXP duration field so that it does not indicate duration information. In this case, the request response PPDU can be a non-HE PPDU.

[0225] Furthermore, the base station wireless communication terminal can send signals to other wireless communication terminals included in the BSS operated by the base station to determine whether the PPDU received by that wireless communication terminal is an inter-BSS PPDU or an intra-BSS PPDU without using the BSS color value. To this end, the base station wireless communication terminal can set the value of the BSS color disable field of the HE operation element to 1. For example, because the number of values ​​that a BSS color bit can represent is less than the number of values ​​a BSS can have, the same BSS color value can be used for different BSSs. In this case, the base station wireless communication terminal can set the value of the BSS color disable field of the HE operation element to 1. If the value of the BSS color disable field of the HE operation element obtained by the wireless communication terminal is 1, the wireless communication terminal can use the MAC header address field instead of the BSS color value indicated by the PPDU to determine whether the PPDU received by the wireless communication terminal is an inter-BSS PPDU or an intra-BSS PPDU. Additionally, when the base station wireless communication terminal sets the value of the BSS color disable field of the HE operation element to 1, the base station wireless communication terminal can set the value of the TOXP duration field so that the TOXP duration field does not indicate duration information.

[0226] However, when the TXOP duration field of a triggered PPDU does not indicate duration information, a wireless communication terminal that is not intended to receive a triggered PPDU may not obtain duration information from the triggered PPDU or the frames contained within it. This is because a wireless communication terminal that is not intended to receive a triggered PPDU cannot decode the triggered PPDU frame.

[0227] exist Figure 20 In one embodiment, the AP operating the first BSS (BSS1) sets the TXOP duration field of the PPDU (PPDU) including the trigger frame to not indicate duration information. At this time, when the second station supports PPDU reception, the second station can obtain duration information from the frame included in the PPDU. Because the TXOP duration field of the PPDU does not indicate duration information, the second station sets the TXOP duration field of the trigger-based PPDU transmitted in response to the PPDU including the trigger frame to not indicate duration information. The first station STA1 receives the trigger-based PPDU, but cannot obtain duration information from the trigger-based PPDU or the frame included in the trigger-based PPDU. Therefore, the first station STA1 does not set NAV (Non-Active Virtualization), and the frame exchange sequence between the AP and the second wireless communication terminal may not be adequately protected. Therefore, a method to solve these problems is needed. (See reference...) Figure 21 This will be described.

[0228] Figure 21 This illustrates a wireless communication terminal setting the TXOP duration field of the PPDU according to another embodiment of the present invention.

[0229] When a wireless communication terminal sends a trigger-based PPDU, it can set the value of the TXOP duration field so that the TXOP duration field always indicates duration information. Specifically, when a wireless communication terminal acting as a TXOP responder sends a trigger-based PPDU, regardless of whether the TXOP duration field of the requesting response PPDU indicates duration information, the wireless communication terminal can set the value of the TXOP duration field so that the TXOP duration field of the sent PPDU always indicates duration information. However, when a wireless communication terminal acting as a TXOP responder sends a HE SU PPDU or HE ER PPDU, the wireless communication terminal can set the TXOP duration field so that the TXOP duration field of the sent PPDU does not indicate duration information.

[0230] exist Figure 21In this embodiment, the AP configuring the first BSS (BSS1) includes a PPDU (PPDU) containing a trigger frame whose TXOP duration field does not indicate duration information. In this case, when the second station supports PPDU reception, the second station can obtain duration information from the frame included in the PPDU. Although the TXOP duration field of the PPDU does not indicate duration information, the second station sets the value of the TXOP duration field such that the TXOP duration field of the trigger-based PPDU transmitted in response to the PPDU containing the trigger frame indicates duration information. The first station (STA1) can receive trigger-based PPDUs, but can configure NAV (Network Access Vendor) by obtaining duration information from the trigger-based PPDUs. Therefore, even when the first station (STA1) does not receive a PPDU containing the trigger frame, the frame exchange sequence between the AP and the second station can be protected.

[0231] When a base station wireless communication terminal changes the BSS color of its BSS, wireless communication terminals included in the same BSS can use different BSS colors. Specifically, before changing the BSS color, the base station wireless communication terminal can send signaling information about the BSS color change as described above. In this case, the signaling information about the BSS color change can be a HE BSS color change notification element. However, if a wireless communication terminal included in the corresponding BSS fails to receive the signaling information about the BSS color change and fails to receive the HE operation element after the BSS color change, wireless communication terminals included in the same BSS can use different BSS colors. In this case, refer to... Figure 22 Describe the potential problems.

[0232] Figure 22 A wireless communication terminal according to an embodiment of the present invention is shown performing UL MU transmission.

[0233] A wireless communication terminal receiving a PPDU including trigger information can set the value of the BSS color indicated by the trigger-based PPDU to the value of the BSS color field of the most recently received HE operation element. Specifically, when the PPDU including trigger information does not include a field indicating the BSS color, the wireless communication terminal receiving the PPDU including trigger information can set the value of the BSS color indicated by the trigger-based PPDU to the value of the BSS color field of the most recently received HE operation element. Additionally, when the wireless communication terminal receiving the PPDU including trigger information cannot use the value of the BSS color indicated by the trigger-based PPDU, it can set the value of the BSS color indicated by the trigger-based PPDU to the value of the BSS color field of the most recently received HE operation element. In these embodiments, if the wireless communication terminal does not receive an HE operation element after changing the BSS color, the wireless communication terminal can transmit a modulated signal of the HE-SIG-A field that is different from the modulated signal of the HE-SIG-A field of another wireless communication terminal simultaneously transmitting a trigger-based PPDU. As a result, the base station wireless communication terminal may be unable to receive the trigger-based PPDU.

[0234] exist Figure 22 In this embodiment, the AP sends a beacon frame including a HE BSS color change notification element. In this case, the value of the new BSS color field of the HE color change notification element is y, the value of the BSS color field of the HE operation element is x, and the color switching inverse segment indicates 3. First station STA1 and second station STA2 receive this beacon frame to obtain the HE BSS color change notification element. Each time the AP sends a beacon frame containing the HE BSS color change notification element, the AP decrements the value of the color switching inverse segment and repeatedly sends the beacon frame containing the HE BSS color change notification element. When the value of the color switching inverse segment becomes 0, the AP begins using the new BSS color value. Therefore, when the AP sends a PPDU with its color switching inverse segment value of 0, the AP sets the value of the BSS color field of the HE operation element to y.

[0235] Because the time point of the BSS color change notification signal sent via the HE BSS color change notification element has elapsed, both the first station STA1 and the second station will change the value of the effective BSS color to y. However, the first station STA1 receives the beacon frame after the BSS color change, but the second station STA2 cannot receive the beacon frame after the BSS color change. Subsequently, the AP uses a PPDU instead of the HE PPDU to send the trigger frame. In this case, because the value of the BSS color field of the most recently received HE operation element is y, the first station STA1 sends a trigger-based PPDU indicating the BSS color y. Because the value of the BSS color field of the most recently received HE operation element is x, the second station STA2 sends a trigger-based PPDU indicating the BSS color x. Therefore, the AP may be unable to receive the trigger-based PPDUs sent by both the first station STA1 and the second station STA2.

[0236] Figure 23 A wireless communication terminal according to another embodiment of the present invention is shown performing UL MU transmission.

[0237] When a wireless communication terminal sends a trigger-based PPDU, it can configure the trigger-based PPDU to indicate the valid BSS color of the wireless communication terminal. More specifically, when the wireless communication terminal sends a trigger-based PPDU, it can set the value of the BSS color field of the HE-SIG-A field of the trigger-based PPDU to the valid BSS color of the wireless communication terminal. According to a specific embodiment, when the wireless communication terminal receives a PPDU that includes a trigger frame but does not indicate a value for the BSS color, it can set the value of the BSS color field of the HE-SIG-A field of the trigger-based PPDU to the valid BSS color of the wireless communication terminal. A PPDU that includes a trigger frame but does not indicate a value for the BSS color can indicate a non-HE PPDU. As mentioned above, after receiving a BSS color change notification element, as the BSS color change time point elapses, the wireless communication terminal can set the value of the new BSS color field of the BSS color change notification element to the value of the valid BSS color.

[0238] exist Figure 23 In this embodiment, besides the operation of the first station STA1 and the second station STA2 sending trigger-based PPDUs, the operations of the AP, the first station STA1, and the second station STA2 are the same as... Figure 22The operations in the embodiments are the same. The second station STA2 did not receive the HE operation element from the AP after the BSS color changed. However, both the first stations SAT1 and STA2 set the value of the BSS color field of the HE-SIG-A based on the valid BSS color. Therefore, both the first station SAT1 and the second station STA2 sent a trigger-based PPDU indicating a value of y for the BSS color, and thus the AP successfully sent a trigger-based reception from each of the first station SAT1 and the second station SAT2.

[0239] pass Figures 24 to 25 This document describes a method for sending a trigger-based PPDU to a base station wireless communication terminal via a wireless communication terminal not associated with that base station wireless communication terminal. Specifically, a method is shown that transmits information about an operation channel operated by the base station wireless communication terminal to a base station wireless communication terminal not associated with that base station wireless communication terminal.

[0240] Figure 24 The encoded value of the RU allocation field used by a wireless communication terminal according to an embodiment of the present invention is shown.

[0241] When a trigger frame indicates an RU, the trigger frame can indicate the relative position and size of the RU in the operating channel of the BSS that sent the frame. In this case, the relative position and size of the RU can be a predetermined combination of relative positions and sizes. For example, the trigger frame can indicate which RU of a specific size it corresponds to.

[0242] More specifically, the trigger frame can be referenced. Figure 8The described RU allocation field indicates the relative position and size of the RU. The bit corresponding to bit index 12 of the RU allocation field can indicate whether the RU is located in the primary 80MHz channel. Furthermore, when the RU is located in a secondary 80MHz channel, the value of the bit corresponding to bit index 12 of the RU allocation field can be 1. When the RU has a size of 160MHz (2*996 tone RUs), the value of the bit corresponding to bit index 12 of the RU allocation field can be a predetermined value. In another specific embodiment, when the RU has a size of 160MHz (2*996 tone RUs), the value of the bit corresponding to bit index 12 of the RU allocation field can be set to any value. Additionally, the values ​​corresponding to bit indices 19 to 13 of the RU allocation field can indicate the index and size of the RU. When the values ​​corresponding to bit indices 19 to 13 of the RU allocation field are 0 to 36, these values ​​indicate the number of cases where 26-tone RUs can be located in a frequency band with an 80MHz bandwidth. Conversely, when the values ​​corresponding to bit indices 19 to 13 of the RU allocation field are 37 to 52, these values ​​indicate the number of cases where 52-tone RUs can be located in a frequency band with an 80MHz bandwidth. More specifically, the values ​​corresponding to bit indices 19 to 13 of the RU allocation field and the positions of the RUs can be as follows: Figure 24 The mapping is shown in the figure.

[0243] Figure 25 This illustration shows UL MU transmission for a base station wireless communication terminal that is not associated with a wireless communication terminal, according to an embodiment of the present invention.

[0244] As described above, a wireless communication terminal not associated with a base station wireless communication terminal can perform transmissions to a base station wireless communication terminal based on random access without obtaining HE operating elements or VHT operating elements. More specifically, a wireless communication terminal not associated with a base station wireless communication terminal can perform transmissions to a UORA-based base station wireless communication terminal using the default UORA parameter set without obtaining HE operating elements. However, in addition to information about the UORA parameter set, the HE operating element can also indicate information about the operating channel of the BSS operated by the base station wireless communication terminal. More specifically, the HE operating element can signal information about the main 20MHz channel used by the base station wireless communication terminal. Additionally, the HE operating element can signal information about the center frequency of the 80MHz segment. Furthermore, as referenced... Figure 24As described, a trigger frame can indicate the relative location of the RU to be used by the wireless communication terminal triggered by the trigger frame. Therefore, when a wireless communication terminal not associated with the base station wireless communication terminal does not obtain the HE operation element, the trigger frame may not accurately determine the location of the RU indicating random access.

[0245] As in Figure 25 In one embodiment, the AP can transmit a PPDU including a trigger frame using a frequency band with a bandwidth greater than 20MHz. In this case, a station not associated with the AP receives the trigger frame on a channel other than the 20MHz main channel used by the base station's wireless communication terminal. In this case, the trigger frame can be transmitted as a non-HT repeating PPDU. Alternatively, the trigger frame can be transmitted via an HE PPDU, where the traditional preamble and HE-SIG-A field are repeated every 20MHz. In this case, the station not associated with the AP can receive the trigger frame but cannot determine the location of the main 20MHz channel used by the base station's wireless communication terminal. Therefore, the station not associated with the AP may not be able to accurately determine the location of the RU for random access indicated by the trigger frame. As a result, the station not associated with the AP may attempt random access to an RU where the trigger frame does not indicate random access. Furthermore, even if the station not associated with the AP successfully transmits the trigger-based PPDU, it may not receive an ACK for the trigger-based PPDU because it cannot accurately determine the location of the main 20MHz channel.

[0246] Regarding these issues, the base station wireless communication terminal can insert information about the operation channel of the BSS operated by the base station wireless communication terminal into the trigger frame. Specifically, the base station wireless communication terminal can insert information about the primary channel used by the base station wireless communication terminal into the trigger frame. In a particular embodiment, the base station wireless communication terminal can insert information about the 20MHz primary channel used by the base station wireless communication terminal into the trigger frame. Additionally, the base station wireless communication terminal can insert information about the 80MHz primary channel used by the base station wireless communication terminal into the trigger frame. The information about the 80MHz primary channel can be a 1-bit indicator indicating whether the RU transmitting the trigger frame is a primary 80MHz channel. Alternatively, the information about the 80MHz primary channel can be information indicating the center frequency of the 80MHz band. Furthermore, when the trigger frame triggers random access by a wireless communication terminal not associated with the base station wireless communication terminal, the base station wireless communication terminal can insert information about the operation channel of the BSS operated by the base station wireless communication terminal into the trigger frame. Additionally, the wireless communication terminal not associated with the base station wireless communication terminal can obtain information about the operation channel of the BSS from the trigger frame and determine the location of the RU indicated by the trigger frame based on the information about the operation channel of the BSS.

[0247] In another specific embodiment, the base station wireless communication terminal may transmit a PPDU including a trigger frame without using the 160MHz or 80MHz frequency band. In another specific embodiment, the base station wireless communication terminal may set the value of the RU allocation field of the trigger frame such that only RUs whose trigger frame is not in the 160MHz or 80MHz frequency band are indicated as RUs used for transmissions triggered by the trigger frame. In another specific embodiment, the base station wireless communication terminal may set the value of the RU allocation field of the trigger frame such that only RUs not in the auxiliary 80MHz frequency band are indicated as RUs used for transmissions triggered by the trigger frame. When the trigger frame triggers random access for a wireless communication terminal not associated with the base station wireless communication terminal, the base station wireless communication terminal can determine the RU indicated by the trigger frame according to the constraints of any of the above embodiments. Additionally, the base station wireless communication terminal may indicate the RU to be used for random access for a wireless communication terminal not associated with the base station wireless communication terminal in the RUs located in the 80MHz segment where the trigger frame is transmitted.

[0248] Furthermore, through the following embodiments, the base station wireless communication terminal can prevent wireless communication terminals not associated with the base station wireless communication terminal from not receiving responses to trigger-based PPDUs. More specifically, the base station wireless communication terminal can use non-HT repeating PPDUs to transmit responses to trigger-based PPDUs transmitted by wireless communication terminals not associated with the base station wireless communication terminal. This is because when a response to a trigger-based PPDU is transmitted to a non-HT repeating PPDU, the wireless communication terminal not associated with the base station wireless communication terminal can receive the non-HT repeating PPDU transmitted by the base station wireless communication terminal, regardless of which 20MHz channel is received. In this case, the base station wireless communication terminal can transmit responses to trigger-based PPDUs transmitted by wireless communication terminals not associated with the base station wireless communication terminal in the frequency band in which the base station wireless communication terminal transmits trigger frames or in a frequency band including the frequency band in which the wireless communication terminal transmits trigger frames.

[0249] Furthermore, the base station wireless communication terminal can use a wideband frequency band with a bandwidth greater than 20 MHz to transmit responses to trigger-based PPDUs transmitted by wireless communication terminals unrelated to the base station wireless communication terminal. In this case, the wideband frequency band with a bandwidth greater than 20 MHz may include a frequency band for trigger-based PPDU transmissions by wireless communication terminals unrelated to the base station wireless communication terminal. Additionally, the base station wireless communication terminal can transmit responses to trigger-based PPDUs transmitted by wireless communication terminals unrelated to the base station wireless communication terminal to an HE SUPPDU or HE MU PPDU. In such embodiments, the base station wireless communication terminal can transmit responses to trigger-based PPDUs transmitted by wireless communication terminals unrelated to the base station wireless communication terminal in the frequency band where the base station wireless communication terminal transmits the trigger frame, or in a frequency band including the frequency band where the base station wireless communication terminal transmits the trigger frame. When the base station wireless communication terminal transmits responses to trigger-based PPDUs in a frequency band with a bandwidth of 160 MHz or 80+80 MHz, the base station wireless communication terminal can use a predetermined 80 MHz segment to transmit the responses to trigger-based PPDUs. In this case, the predetermined 80MHz segment can be an 80MHz segment that includes the frequency band in which the base station wireless communication terminal transmits the trigger frame.

[0250] In the above embodiments, the response to a trigger-based PPDU can be an immediate response to the trigger-based PPDU. Alternatively, the response to a trigger-based PPDU can be a response sent after a TXOP in which the trigger-based PPDU was sent. For example, a trigger-based PPDU may include at least one of a probe request frame, a (re)association request frame, and an authentication request frame. The response to a trigger-based PPDU may include at least one of a probe response frame, a (re)association response frame, and an authentication response frame.

[0251] When a contention process is performed for each MPDU transmission, transmission efficiency can rapidly decrease as the number of MPDUs to be transmitted increases. To improve the transmission efficiency of a wireless communication terminal, multiple MPDUs can be combined to generate an aggregated MPDU (A-MPDU) and then transmitted. (See reference...) Figures 26 to 27 This will be described.

[0252] Figure 26 This invention illustrates a method for generating an A-MPDU by aggregating MPDUs via a wireless communication terminal, according to an embodiment of the present invention.

[0253] When a wireless communication terminal generates an A-MPDU, it can identify a single MPDU and insert a delimiter for signaling information about the MPDU before the single MPDU. This delimiter may include an End-of-Frame (EOF) field indicating whether it is the last MPDU in the A-MPDU series, a length field indicating the length of the MPDU, a CRC field for detecting errors in the delimiter, and a delimiter signature field for detecting errors in the delimiter. A delimiter with a value of 0 in the EOF field and a non-zero value in the length field indicates that the MPDU following the delimiter includes data corresponding to the TID agreed upon on the BlockACK transmission. In this way, one or more MPDUs indicated by the delimiter can be referred to as pre-EOF padded A-MPDUs. A delimiter with a value of 1 in the EOF field and a value of 0 in the length field indicates the end of the A-MPDU following the pre-EOF padded A-MPDU. One or more of these delimiters can be referred to as EOF padded delimiters. Figure 26 (a) shows specific examples of pre-EOF filled A-MPDU and EOF filled.

[0254] When the transmitter sends an A-MPDU, the receiver may need to send a BlockAck-based response frame including a BlockAck (BA) bitmap. Therefore, the transmission efficiency of the response frame for the A-MPDU is reduced when the A-MPDU contains only one MPDU. Furthermore, in the 802.11ac standard, the wireless communication terminal should send all MPDUs included in the VHT PPDU to the A-MPDU. To improve this inefficiency, an ACK frame response can be allowed for an A-MPDU that includes only one MPDU. Specifically, when the EOF field of the delimiter is 1 and the length field is not 0, the delimiter can indicate that the MPDU following the delimiter is a single MPDU (S-MPDU) within the A-MPDU. The aforementioned EOF padding can be placed after the S-MPDU. When the wireless communication terminal receives an A-MPDU indicating an S-MPDU, it can send an ACK frame other than a BlockAck as a response to the A-MPDU, regardless of whether the BA is consistent with the TID corresponding to the received MPDU. Figure 26 (b) shows a specific example of an A-MPDU that includes an S-MPDU.

[0255] Figure 27 A method for generating an A-MPDU from a wireless communication terminal according to another embodiment of the present invention is shown.

[0256] In a particular embodiment, the wireless communication terminal can generate an A-MPDU by combining only MPDUs with the same Service Identifier (TID). In such an embodiment, the wireless communication terminal may not aggregate MPDUs corresponding to multiple TIDs in the A-MPDU, and therefore may not transmit the maximum size that can be transmitted using the A-MPDU. This may reduce the transmission efficiency via the A-MPDU. In another particular embodiment, the wireless communication terminal can aggregate multiple MPDUs with different TIDs to generate a single A-MPDU. For ease of explanation, an A-MPDU comprising multiple MPDUs corresponding to multiple different TIDs will be referred to as a multi-TID A-MPDU or an A-MPDU with multiple TIDs. In this embodiment, the number of A-MPDU types and the number of response methods for the A-MPDU become larger than in the aforementioned embodiments.

[0257] More specifically, a wireless communication terminal can generate an A-MPDU by aggregating multiple MPDUs with a value of 1 in the EOF field. In this case, each of the multiple MPDUs can correspond to a different TID and can be a unique MPDU corresponding to each TID. When an MPDU including Quality of Service (QoS) data corresponding to a TID with a BA protocol is a unique MPDU corresponding to a specific TID within that A-MPDU, the wireless communication terminal can set the value of the EOF field of the delimiter corresponding to the MPDU to 1. Figure 27 (a) shows a specific example of an A-MPDU in which multiple MPDUs with an EOF field value of 1 are aggregated. Additionally, when the action frame responding to a request ACK frame is unique within the corresponding A-MPDU, the EOF field value of the delimiter corresponding to that action frame can be set to 1. Figure 27 (b) shows a specific example where an MPDU with an EOF field value of 1 and an A-MPDU with an EOF field value of 1 are aggregated. When an MPDU corresponding to a delimiter with an EOF field value of 1 is sent separately, the receiver can send an ACK frame in response to the MPDU. Figure 27 (c) shows the case where the A-MPDU includes only one MPDU corresponding to a delimiter with an EOF field of 1.

[0258] When an MPDU corresponding to a delimiter with an EOF field of 1 is sent along with another MPDU requiring an immediate response, the receiver may send each AID TID field where the BA bitmap is omitted in the multi-BA (M-BA) in response to the MPDU corresponding to a delimiter with an EOF field of 1. In this case, the receiver may set the value of the Ack type field of each AID TID field, where the BA bitmap is omitted, to a different value than the Ack type field of each other AID TID field that includes the BA bitmap. More specifically, the receiver may set the value of the Ack type field of each AID TID field to 1. Furthermore, each AID TID field where the BA bitmap is omitted is referred to as the Ack context, and each AID TID field that includes the BA bitmap is referred to as the BA context.

[0259] The wireless communication terminal sets the EOF field value of the corresponding delimiter to 1, aggregates the MPDU corresponding to the TID without the BA protocol and the MPDU corresponding to another TID, and transmits the MPDU corresponding to the TID without the BA protocol and the MPDU corresponding to the other TID. In this case, the receiver can transmit an M-BA including an Ack context response in response to the MPDU corresponding to the TID without the BA protocol. When the wireless communication terminal transmits the MPDU corresponding to the TID without the BA protocol using the A-MPDU, it can ensure that the MPDU corresponding to the TID without the BA protocol is the only MPDU in the corresponding A-MPDU corresponding to that TID. Therefore, the wireless communication terminal can set the EOF field value of the delimiter of the MPDU corresponding to the TID without the BA protocol to 0. In this case, when another MPDU of the A-MPDU needs an immediate response, the receiver can transmit an M-BA including an Ack context response in response to the MPDU corresponding to the TID without the BA protocol. Alternatively, the wireless communication terminal can set the EOF field value of the delimiter of the MPDU corresponding to the TID with the BA protocol to 0. In such an embodiment, even if the EOF field value of the delimiter is 1, the receiver cannot determine that the MPDU corresponding to the delimiter is the unique MPDU among the A-MPDUs based solely on the corresponding delimiter. In this case, the receiver can determine that the MPDU is the unique MPDU among the corresponding A-MPDUs based on the data included in the MPDU and other delimiters.

[0260] As described above, in frequency bands commonly used by various wireless communication devices (such as unlicensed frequency bands), wireless communication terminals can access channels through a contention process. Specifically, when the channel to be accessed by the wireless communication terminal is idle for a predetermined time, the wireless communication terminal initiates a backoff process. During the backoff process, the wireless communication terminal obtains a random integer value in the contention window (CW) and sets this random integer value as a backoff timer. When the corresponding channel is idle for a predetermined time slot, the wireless communication terminal decrements the backoff timer. When the backoff timer value is 0, the wireless communication terminal accesses the corresponding channel. In this case, when the corresponding channel is busy, the wireless communication terminal stops the backoff process. When the channel to be accessed by the wireless communication terminal is idle for a predetermined time, the wireless communication terminal resumes the backoff process.

[0261] Furthermore, wireless communication terminals can access the channel based on the priority of the data to be transmitted. Specifically, the wireless communication terminal can use a Channel Warp Weight (CW) determined according to the priority of the data to be transmitted. In this case, the minimum CW (CWmin) and maximum CW (CWmax) are determined based on the priority of the data to be transmitted by the wireless communication terminal. Additionally, a predetermined time for the wireless communication terminal to wait before initiating the backoff process is determined based on the priority of the data to be transmitted. Alternatively, the wireless communication terminal can wait for a specified time based on the priority of the data to be transmitted and then initiate the backoff process. The time specified according to priority is called the Arbitration Inter-Frame Spacing (AIFS). This operation is called Enhanced Distributed Channel Access (EDCA). Furthermore, the data priority can be determined based on the Access Class (AC).

[0262] As described above, a base station wireless communication terminal can trigger uplink transmissions to one or more other wireless communication terminals. In this case, the base station wireless communication terminal accesses a channel designated for uplink transmissions by one or more wireless communication terminals. Furthermore, one or more wireless communication terminals access the channel to perform uplink transmissions for each of the one or more wireless communication terminals. Therefore, when uplink transmissions of one or more wireless communication terminals are scheduled for uplink transmissions performed by the base station wireless communication terminal, these uplink transmissions have a higher priority than those of other wireless communication terminals transmitting data with the same priority. Additionally, because the base station wireless communication terminal and one or more other wireless communication terminals simultaneously access the channel for the same transmission, channel access efficiency may decrease. Therefore, it is necessary to adjust the EDCA parameter value when scheduling uplink multi-user (UL-MU) transmissions. (Refer to...) Figures 28 to 31 This will be described.

[0263] Figure 28This invention illustrates a method for controlling EDCA parameters used by a wireless communication terminal during MU UL transmission.

[0264] When a wireless communication terminal scheduled for UL MU transmission successfully completes UL MU transmission, it can use a channel access method with a lower probability of guaranteeing successful channel access compared to when it is not scheduled for UL MU transmission. More specifically, the wireless communication terminal can use a separate EDCA parameter set. In a particular embodiment, the corresponding wireless communication terminal can use an EDCA parameter set that attempts to access the channel with a lower probability than the previously used EDCA parameter set in channel access for transmitting the same data. In this case, the EDCA parameter set is a set of parameters used in EDCA operation based on the priority of the data transmitted by the wireless communication terminal. Specifically, the EDCA parameter set may include parameters for CW. In this case, the parameters for CW may include at least one of CWmin and CWmax. Additionally, the EDCA parameter set may include parameter values ​​related to a predetermined time for the wireless communication terminal to wait to begin the backoff process. In this case, the predetermined time may be the AIFS described above. For ease of description, the separate EDCA parameter set used by the corresponding wireless communication terminal when it is scheduled for UL MU transmission successfully completes UL MU transmission is referred to as the MU EDCA parameter set.

[0265] Additionally, when a wireless communication terminal scheduled for UL MU transmission successfully completes UL MU transmission, it can be considered that all of the following conditions are met: 1) The wireless communication terminal sends information about the data to be transmitted to the base station wireless communication terminal. In this case, the wireless communication terminal can send information about the data to be transmitted to the base station wireless communication terminal by sending a Buffer Status Report (BSR). 2) The wireless communication terminal receives trigger information, which includes a user information field indicating the wireless communication terminal's AID. In this case, the trigger information can be a trigger frame. 3) The wireless communication terminal transmits QoS data in response to the trigger information. 4) The wireless communication terminal determines that the QoS data transmission was successful. In this case, the wireless communication terminal can determine that the QoS data transmission was successful when it receives an immediate response to the QoS data transmission.

[0266] The base station wireless communication terminal can send information about the MU EDCA parameter set to the wireless communication terminal. More specifically, the base station wireless communication terminal can send MU EDCA parameter set elements, which include information about the MU EDCA parameter set, to the wireless communication terminal. In this case, the base station wireless communication terminal can use beacon frames to send the MU EDCA parameter set elements.

[0267] When the wireless communication terminal receives the MU EDCA parameter set elements and meets the above conditions, the wireless communication terminal can update the EDCA parameter values ​​of all ACs corresponding to the QoS data sent by the wireless communication terminal via the triggered PPDU. Specifically, the wireless communication terminal can update the end time point of the triggered PPDU, which includes immediate responses to the triggered PPDU, or the end value of the triggered PPDU, which includes QoS data that does not request an immediate response, using the EDCA parameter values ​​of all ACs corresponding to the QoS data.

[0268] When the MU EDCA parameter set application conditions are not met until a predetermined time has elapsed since the timer was set, the wireless communication terminal can set a MU EDCA timer to terminate the MU EDCA parameter set application. Specifically, the wireless communication terminal can set the MU EDCA timer when a trigger message is received. In this case, if the MU EDCA parameter set application conditions are not met within a certain period after the MU EDCA timer is set, the wireless communication terminal can terminate the MU EDCA parameter set application. In this case, the MU EDCA timer can be applied to each AC. Furthermore, the MU EDCA timer value can also be included in the MU EDCA parameter set. Therefore, the base station wireless communication terminal can send MU EDCA parameter set elements including information about the MU EDCA timer value to the wireless communication terminal.

[0269] exist Figure 28 In this embodiment, the AP sends a trigger frame to the first station STA1. The first station STA1 receives the trigger frame from the AP and sends a trigger-based PPDU based on the trigger frame, where the AC includes QoS data corresponding to the BE. The AP receives the trigger-based PPDU from the first station STA1 and sends an M-BA in response to an MPDU including the trigger-based PPDU. The first station STA1 receives the M-BA from the base station wireless communication terminal and applies the MU EDCA parameter set to the QoS data where the AC is the BE. In this case, the first station STA1 sets a MU EDCA timer for the QoS data where the AC is the BE. Before the MU EDCA timer expires, the first station STA1 does not successfully send the UL MU. Therefore, when the MU EDCA timer expires, the first station STA1 terminates the application of the MU EDCA parameter set.

[0270] Figure 29 A method for transmitting a BSR by a wireless communication terminal according to an embodiment of the present invention is shown.

[0271] As mentioned above, for a base station wireless communication terminal, it is important to determine the buffer status of the wireless communication terminal associated with it. To this end, the wireless communication terminal can use various methods to send a Buffer Status Report (BSR) to the base station wireless communication terminal. More specifically, the wireless communication terminal can use the queue size subfield of the QoS control field of the QoS data to send a Buffer Status Report (BSR). In this case, the BSR is information indicating the buffer status.

[0272] The wireless communication terminal can set the 2 most significant bits (MSB) as the SF subfield indicating the scaling factor in the queue size subfield, and set the remaining 6 bits as the UV subfield indicating the unscaled value. The specific format of the queue size subfield can be as follows: Figure 29 As shown in the diagram. In this case, the wireless communication terminal can obtain an approximate value of the total amount of MPDUs included in the currently transmitted A-MPDU and the total amount of data stored in the buffer of the same TID according to the formula specified for each scaling factor, and insert the obtained approximate value into the queue size subfield. The wireless communication terminal can perform rounding operations while obtaining the approximate value of the total amount of data. The base station wireless communication terminal can estimate the total amount of buffered data of the wireless communication terminal based on the queue size subfield received from the wireless communication terminal. In this case, because the wireless communication terminal determines the value of the queue size subfield based on the rounded total value of the buffered data, even if the buffer of the wireless communication terminal corresponding to a specific TID is empty, the base station wireless communication may determine that the data is buffered by a value within the wrong range due to the rounding operation on the buffer of the wireless communication terminal corresponding to a specific TID. Therefore, the base station wireless communication terminal can additionally and unnecessarily schedule the UL transmission of the wireless communication terminal. Therefore, the wireless communication terminal can obtain an approximate value of the total amount of MPDUs included in the currently transmitted A-MPDU and the total amount of data stored in the buffer of the same TID by using a rounding operation. More specifically, the base station wireless communication terminal can obtain the value to be inserted into the queue size subfield according to the following rules.

[0273] - When the scaling factor is 0, the wireless communication terminal can round down the actual queue size to the nearest 16 octets and insert it into the UV subfield.

[0274] - When the scaling factor is 1, the wireless communication terminal can round down the value obtained by subtracting 1024 from the actual queue size to the nearest 256 octets and insert it into the UV subfield.

[0275] - When the scaling factor is 2, the wireless communication terminal can round down the value obtained by subtracting 17408 from the actual queue size to the nearest 2048 octets and insert it into the UV subfield.

[0276] - When the scaling factor is 3, the wireless communication terminal can round down the value obtained by subtracting 148,480 from the actual queue size to the nearest 32,768 octets and insert it into the UV subfield.

[0277] In this context, the actual queue size can indicate the total amount of data included in the MPDU currently being sent and the data stored in the buffer with the same TID.

[0278] In this embodiment, even if the data sent from the AP to the terminal is retained in the wireless communication terminal's buffer, the base station wireless communication terminal may not schedule the corresponding UL transmission of the wireless communication terminal. However, the wireless communication terminal can send the data stored in the buffer via SU transmission, and can also send the data stored in the buffer together when scheduling uplink transmissions for another TID. Therefore, the case where the wireless communication terminal inserts the value obtained based on the lower rounding operation into the queue size subfield may be more efficient in terms of resource management than the case where the wireless communication terminal inserts the value obtained based on the upper rounding operation into the queue size subfield.

[0279] In another specific embodiment, when the wireless communication terminal transmits all buffered data of the TID indicated by the queue size subfield, the wireless communication terminal may set the value of the queue size subfield to a predetermined value. In this case, the predetermined value may be 11111110.

[0280] Figure 30 The target wake-up time (TWT) operation of a wireless communication terminal according to an embodiment of the present invention is illustrated.

[0281] In the 802.11ah standard, the wireless communication terminal and the base station wireless communication terminal separately set the TWT and the TWT's service period (SP). According to an embodiment of the present invention, the base station wireless communication terminal can signal information related to the TWT and the TWT's SP to all wireless communication terminals of the BSS operated by the base station wireless communication terminal. More specifically, the base station wireless communication terminal can signal information related to the TWT and the corresponding TWT's SP using beacon frames. The base station wireless communication terminal can signal that it will send a trigger frame in the TWT's SP, which triggers random access based on uplink transmission. In this case, the base station wireless communication terminal sets the trigger field of the request type field in the TWT element to 1 and sets the TWT stream identifier field to a value other than 1, so that it can indicate that a trigger frame for triggering uplink transmission based on uplink transmission will be sent in the TWT's SP. In such an embodiment, a wireless communication terminal supporting random access can perform TWT operations without additional negotiation with the base station wireless communication terminal. More specifically, the wireless communication terminal can remain in a dormant state until the TWT and transition to a wake-up state during the TWT. In this case, the wireless communication terminal can send a frame indicating that the wireless communication terminal is in a wake-up state to the base station wireless communication terminal. In this case, the frame indicating the wake-up status can be a PS polling frame or an unscheduled Automatic Power Saving Delivery (U-APSD) trigger frame.

[0282] Furthermore, the base station wireless communication terminal can send a trigger frame in the TWT, which triggers the transmission of information about the buffer state of the wireless communication terminal in the wake-up state. In this case, the information about the buffer state can be a bufferable unit (BU). Additionally, the trigger frame used to trigger the transmission of information about the buffer state can trigger uplink-based transmissions of all wireless communication terminals operating through the base station wireless communication terminal's BSS, as well as the wireless communication terminal performing the TWT operation. Therefore, the random access success rate of the wireless communication terminal performing the TWT operation may be very low. Therefore, the wireless communication terminal can set the receiver address (RA) field of the trigger frame sent at the TWT to the group address of the wireless communication terminals participating in the TWT operation. More specifically, the base station wireless communication terminal can set the RA field of the trigger frame sent at the TWT, such as... Figure 30 As shown in 1). Additionally, the base station wireless communication terminal can use the TWT element to send the group address of the wireless communication terminal participating in the TWT operation via a signal. In this embodiment, when the wireless communication terminal receives a trigger frame in which the value of the RA field is the group address of the wireless communication terminal participating in the TWT operation, only the wireless communication terminal that wants to exchange frames with the wireless communication terminal in the TWT SP can attempt random access based on the trigger frame.

[0283] In another specific embodiment, the base station wireless communication terminal may set the value of the AID12 subfield of the user information field in the trigger frame transmitted at the TWT to a predetermined value indicating that the wireless communication terminal participates in the TWT operation. In this case, the predetermined value may be a reserved value not assigned for other purposes. For example, the predetermined value may be 2044. More specifically, the base station wireless communication terminal may set the value of the AID12 subfield of the user information field transmitted at the TWT, such as... Figure 30 As shown in 2). When the value of the AID12 subfield of the user information field of the trigger frame received by the wireless communication terminal is a predetermined value, the wireless communication terminal used only to exchange frames with the base station wireless communication terminal in the TWT SP attempts random access in the RU indicated by the corresponding user information field.

[0284] In another specific embodiment, the base station wireless communication terminal may set the value of a specific subfield of the trigger-related user information field of the user information field of the trigger frame transmitted at the TWT to a predetermined value. In this case, the specific subfield of the trigger-related user information field may be a TID aggregation limit field. In this case, the TID aggregation limit field may be a field used to indicate a limit on the number of TIDs corresponding to the data that can be aggregated in the A-MPDU transmitted based on the trigger frame. For example, the base station wireless communication terminal may set the value of the TID aggregation limit field to six. More specifically, the base station wireless communication terminal may set the TID aggregation limit field of the trigger-related user information field of the trigger frame transmitted in the TWT, such as... Figure 30 As shown in 3). Additionally, the specific subfield of the triggering related user information field can be one of the reserved fields. When the value of the specific subfield of the triggering related user information field received by the wireless communication terminal is a predetermined value, the wireless communication terminal, used only for exchanging frames with the base station wireless communication terminal in the TWT SP, can attempt random access in the RU indicated by the corresponding user information field.

[0285] In the above embodiments, a wireless communication terminal that wants to exchange frames with a base station wireless communication terminal in the TWT SP can use random access to send only frames indicating that the wireless communication terminal is in a wake-up state. In this case, the frame indicating that the wireless communication terminal is in a wake-up state can be a PS polling frame or a U-APSD trigger frame.

[0286] Figure 31 This illustration shows a wireless communication terminal according to an embodiment of the present invention setting MU EDCA parameters during TWT operation.

[0287] During TWT operation, the wireless communication terminal can perform Opportunistic Power Saving (OPS) operation under predetermined conditions. The base station wireless communication terminal sets the TWT Stream Identifier field to three, indicating that it supports OPS operation. The base station wireless communication terminal can use the TIME element at the start time of the OPS TWT SP to signal scheduling information about all wireless communication terminals participating in the OPS TWT. The base station wireless communication terminal disables the bit corresponding to the wireless communication terminal's AID in the bitmap of the TIM element to indicate wireless communication terminals not scheduled for transmission in the corresponding OPS TWT. Furthermore, for wireless communication terminals not participating in the OPS TWT, the base station wireless communication terminal can signal in the same way as existing TIM elements. Wireless communication terminals not scheduled for transmission in the corresponding OPS TWT can remain dormant until the next OPS TWT. When the corresponding wireless communication terminal requires additional uplink transmission, it can attempt UL SU transmission by operating EDCA separately.

[0288] In this scenario, when the wireless communication terminal uses the MU EDCA parameter set, it may not expect UL MU scheduling, and the probability of successful channel access may be too low. Therefore, it is possible that the wireless communication terminal will be unable to transmit data that urgently needs to be transmitted. In a specific embodiment, when the wireless communication terminal receives a TIM element comprising a bitmap in which the bits corresponding to the wireless communication terminal are deactivated in the OPS TWT SP, the wireless communication terminal may stop using the MU EDCA parameter set. More specifically, when the wireless communication terminal receives a TIM element comprising a bitmap in which the bits corresponding to the wireless communication terminal are deactivated in the OPS TWT SP, the wireless communication terminal may set the MUEDCA timer to 0. In a specific embodiment, more specifically, when the wireless communication terminal receives a TIM element comprising a bitmap in which the bits corresponding to the wireless communication terminal are deactivated in the OPS TWT SP, the wireless communication terminal may stop applying the MU EDCA parameter set for ACs whose MU EDCA timer values ​​are faster than the next OPS TWT. In a particular embodiment, more specifically, when a wireless communication terminal receives a TIM element comprising a bitmap in which the bit corresponding to the wireless communication terminal is deactivated in the OPSTWT SP, the wireless communication terminal may set its MU EDCA timer to 0 at an AC that is faster than the next OPS TWT. This is because there may be too many wireless communication terminals in the OPS TWT SP for which UL transmissions are not scheduled. Accordingly, this is because the channel access probability of the base station wireless communication terminal may be too low when all wireless communication terminals not scheduled for UL transmissions stop applying the MU EDCA parameter.

[0289] In the above embodiments, when the wireless communication terminal stops applying the MU EDCA parameter set, the wireless communication terminal can set the EDCA parameter set based on the most recently received EDCA parameter set elements. When the wireless communication terminal does not receive any EDCA parameter set elements, the wireless communication terminal can set the EDCA parameter set based on the default EDCA parameter set.

[0290] exist Figure 31 In this embodiment, the first station STA1 applies the MU EDCA parameter set. The first station STA1 receives a TIM / FILS discovery frame from the AP, which includes TIM elements. In this case, the bit in the TIM element bitmap corresponding to the first station STA1 is set to 0. Therefore, the wireless communication terminal stops applying the MU EDCA parameter set by setting the MU EDCA parameters of all ACs to 0.

[0291] Figure 32The operation of a base station wireless communication terminal and a wireless communication terminal according to an embodiment of the present invention is illustrated.

[0292] The base station wireless communication terminal 3201 transmits a PPDU including a trigger frame, which is used to trigger transmission by at least one wireless communication terminal 3203 (S3201). More specifically, the base station wireless communication terminal 3201 can generate a trigger frame for triggering uplink-based random access of at least one wireless communication terminal 3203, and can insert and transmit the trigger frame. In this case, the trigger frame can trigger uplink-based random access of a wireless communication terminal 3203 that is not associated with the BSS operated by the base station wireless communication terminal 3201.

[0293] When a trigger frame triggers random access based on uplink transmission by a wireless communication terminal 3203 that is not associated with the BSS operated by the base station wireless communication terminal 3201, the base station wireless communication terminal 3201 can send a PPDU including the trigger frame using a PPDU format that includes a field indicating the BSS color. More specifically, when a trigger frame triggers random access based on uplink transmission by a wireless communication terminal 3203 that is not associated with the BSS operated by the base station wireless communication terminal 3201, the base station wireless communication terminal 3201 can insert the trigger frame into the HE PPDU. In the above embodiments, the method for setting the value of the field indicating the BSS color can follow the reference... Figures 14 to 15 The described embodiments.

[0294] Furthermore, when a trigger frame triggers random access to a wireless communication terminal 3203 that is not associated with a BSS operated by the base station wireless communication terminal 3201, the base station wireless communication terminal 3201 may insert a field indicating the BSS color into the trigger frame. In this case, the base station wireless communication terminal 3201 may insert the field indicating the BSS color into a user information field, which signals information specifically applied to one or more wireless communication terminals 3203 triggered by the trigger frame. In another specific embodiment, the base station wireless communication terminal 3201 may insert the field indicating the BSS color into a common information field, which signals information typically applied to one or more wireless communication terminals 3203 triggered by the trigger frame.

[0295] The base station wireless communication terminal 3201 can set a specific field of the trigger frame to a predetermined AID value, so that it can trigger random access of the wireless communication terminal 3203 that is not associated with the BSS operated by the base station wireless communication terminal 3201.

[0296] Base station wireless communication terminal 3201 can be based on reference Figure 16The described embodiment triggers random access based on uplink transmission for wireless communication terminal 3203 that is not associated with the BSS operated by base station wireless communication terminal 3201.

[0297] Furthermore, the base station wireless communication terminal 3201 can send a trigger frame based on a predetermined schedule. More specifically, the base station wireless communication terminal 3201 can send a trigger frame according to the TWT operation described above. The trigger frame can trigger uplink-based transmissions of the wireless communication terminal 3203 performing power-saving operations based on a predetermined schedule. In this case, the wireless communication terminal 3203 performing power-saving operations based on the predetermined schedule can remain in a sleep state until the TWT, and change to a wake-up state during the TWT, as described above. The base station wireless communication terminal 3201 can set the receiver address field of the trigger frame to a group address that indicates that the wireless communication terminal 3203 is performing power-saving operations based on the predetermined schedule. In another specific embodiment, the base station wireless communication terminal 3201 can set the AID value indicated by the user information field corresponding to the frequency band allocated for random access for uplink-based transmission to a predetermined value indicating that the wireless communication terminal 3203 is performing power-saving operations based on the predetermined schedule. For example, the predetermined value could be 2044. In this case, the predetermined value could be a reserved value not allocated for other purposes. In another specific embodiment, the base station wireless communication terminal 3201 sets the value of one of the fields determined according to the type of the trigger frame corresponding to the user information field allocated for random access based on uplink transmission to a predetermined value indicating that the wireless communication terminal 3203 performs power-saving operation based on a predetermined schedule. The base station wireless communication terminal 3201 sets the TID aggregation limit field included in the user information field corresponding to the frequency band allocated for random access based on uplink transmission to a predetermined value indicating that the wireless communication terminal 3203 performs power-saving operation based on a predetermined schedule. In this case, the TID aggregation limit field may be a field indicating a limit on the number of TIDs corresponding to the data that can be aggregated in the A-MPDU transmitted based on the trigger frame. Specifically, the base station wireless communication terminal 3201 may, as referenced... Figures 30 to 31 Operate as described in the embodiments.

[0298] Wireless communication terminal 3203 receives a PPDU including a trigger frame from base station wireless communication terminal 3201, which triggers a transmission to base station wireless communication terminal 3201. Wireless communication terminal 3203 sends a trigger-based PPDU to base station wireless communication terminal 3201 based on the trigger frame (S3203). When the PPDU including the trigger frame indicates a Basic Service Set (BSS) color, wireless communication terminal 3203 can set the value of the BSS color indicated by the trigger-based PPDU based on the value of the BSS color indicated by the PPDU including the trigger frame. If the PPDU including the trigger frame does not indicate a BSS color, wireless communication terminal 3203 can set the value of the BSS color indicated by the trigger-based PPDU based on the valid BSS color of wireless communication terminal 3203. In this case, the valid BSS color can indicate the BSS color actually used by wireless communication terminal 3203 as described above. In this embodiment, wireless communication terminal 3203 can receive information about BSS color changes from base station wireless communication terminal. Furthermore, when the BSS color change time point indicated by the information regarding the BSS color change is reached, the wireless communication terminal 3203 can set the effective BSS color to the value of the BSS color indicated by the information regarding the BSS color change. In this case, the BSS color change time point can be set based on the target beacon transmission time sent by the base station wireless communication terminal. Additionally, the specific operation of the wireless communication terminal 3203 can be followed according to the reference... Figures 22 to 23 The described embodiments.

[0299] When a PPDU indicates a portion of the BSS color, and the value of the partial AID is non-zero, the wireless communication terminal 3203 can determine whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the value of the partial BSS color. In this case, the specific operation of the wireless communication terminal 3203 can follow the reference... Figures 18 to 19 The described embodiment. In this embodiment, wireless communication terminal 3203 determines whether or not a PPDU (PPDU) within a BSS (Browser Service Standard) can be applied to a PPDU that does not include a trigger frame, and when a PPDU including a trigger frame as described above is received.

[0300] 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. Furthermore, while the methods, apparatus, and systems of the invention have been described with reference to specific embodiments, some or all of the components or operations of the invention can be implemented using a computer system with a general-purpose hardware architecture.

[0301] 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 related to such combinations and modifications is included within the scope of the present invention.

[0302] 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 by the appended claims.

Claims

1. A wireless communication terminal that communicates wirelessly with a base station wireless communication terminal, the wireless communication terminal comprising: A transceiver configured to transmit and receive wireless signals; and A processor configured to process the wireless signal. The processor is configured as follows: The system receives a Physical Layer Protocol Data Unit (PPDU) including a trigger frame for triggering a transmission to the base station wireless communication terminal, wherein the trigger frame includes an identifier identifying the wireless communication terminal triggered by the trigger frame. When the PPDU uses the signaling field of the PPDU to indicate the Basic Service Set (BSS) color, the value of the BSS color indicated by the PPDU including the trigger frame is set based on the value of the BSS color indicated by the PPDU. When the signaling field of the PPDU does not indicate the BSS color, the value of the BSS color indicated by the trigger-based PPDU is set according to the valid BSS color of the wireless communication terminal, and The trigger-based PPDU is sent based on the trigger frame. Wherein, the BSS color is one of the identifiers used to identify the BSS, and Wherein, when the wireless communication terminal receives information about the BSS color change from the base station wireless communication terminal and reaches the BSS color change time point indicated by the information about the BSS color change, the effective BSS color is the value of the BSS color indicated by the information about the BSS color change.

2. The wireless communication terminal according to claim 1, wherein, The BSS color change time point is set based on the target beacon transmission time sent by the base station wireless communication terminal.

3. The wireless communication terminal according to claim 1, wherein, If the PPDU uses a partial association ID (AID) field to indicate a partial BSS color, then when the value of the partial AID field is non-zero, the processor determines whether the PPDU is an intra-BSS PPDU or an inter-BSS PPDU based on the partial BSS color. The aforementioned AID field is a signaling field used to indicate a portion of the AID value. The intra-BSS PPDU is a PPDU transmitted from a BSS that includes the wireless communication terminal, and the inter-BSS PPDU is a PPDU transmitted from a BSS that does not include the wireless communication terminal.

4. A method for operating a wireless communication terminal that communicates wirelessly with a base station wireless communication terminal, the method comprising: The system receives a Physical Layer Protocol Data Unit (PPDU) including a trigger frame for triggering a transmission to the base station wireless communication terminal, wherein the trigger frame includes an identifier identifying the wireless communication terminal triggered by the trigger frame. When the PPDU uses the signaling field of the PPDU to indicate the Basic Service Set (BSS) color, the value of the BSS color indicated by the PPDU including the trigger frame is set based on the value of the BSS color indicated by the PPDU. When the signaling field of the PPDU does not indicate the BSS color, the value of the BSS color indicated by the trigger-based PPDU is set according to the valid BSS color of the wireless communication terminal, and The trigger-based PPDU is sent based on the trigger frame. Wherein, the BSS color is one of the identifiers used to identify the BSS, and Wherein, when the wireless communication terminal receives information about the BSS color change from the base station wireless communication terminal and reaches the BSS color change time point indicated by the information about the BSS color change, the effective BSS color is the value of the BSS color indicated by the information about the BSS color change.

5. The method according to claim 4, wherein, The BSS color change time point is set based on the target beacon transmission time sent by the base station wireless communication terminal.

6. The method according to claim 4, further comprising: If the PPDU uses a partial associated ID (AID) field to indicate a partial BSS color, then when the value of the partial AID field is non-zero, the PPDU is determined to be either an intra-BSS PPDU or an inter-BSS PPDU based on the partial BSS color. The aforementioned AID field is a signaling field used to indicate a portion of the AID value. The intra-BSS PPDU is a PPDU transmitted from a BSS that includes the wireless communication terminal, and the inter-BSS PPDU is a PPDU transmitted from a BSS that does not include the wireless communication terminal.

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