Wireless communication method using network allocation vector and wireless communication terminal thereof

Abstract

This invention relates to a wireless communication method using network allocation vectors and a wireless communication terminal thereof. A wireless communication terminal is provided. The wireless communication terminal includes a transmitting / receiving unit and a processor. The processor receives a trigger frame using the transmitting / receiving unit and updates the network allocation vector based on the trigger frame. The trigger frame triggers transmission by at least one wireless communication terminal.

Description

[0001] This application is a divisional application of patent application No. 201780064553.5 (PCT / KR2017 / 011617), filed with the China Patent Office on April 18, 2019, with an international application date of October 19, 2017, entitled "A wireless communication method using network allocation vectors and a wireless communication terminal using the method". Technical Field

[0002] This invention relates to a wireless communication method and a wireless communication terminal using enhanced network allocation vectors. 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 base station terminals, and necessitates various technologies to achieve this communication.

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

[0009] Technical issues

[0010] The purpose of embodiments of the present invention is to provide a wireless communication terminal that uses network allocation vectors.

[0011] Technical solution

[0012] According to an embodiment of the present invention, a wireless communication terminal associated with a base station wireless communication terminal includes: a transceiver; and a processor. The processor is configured to use the transceiver to receive Physical Layer Protocol Data Units (PPDUs) from the base station wireless communication terminal, obtain trigger frames from the PPDUs, and update Network Allocation Vector (NAV) frames based on the trigger. The trigger frames can trigger transmissions at least one wireless communication terminal.

[0013] The processor can be configured to send trigger-based PPDUs to the base station wireless communication terminal based on trigger frames, regardless of the value of NAV set based on frames sent from the basic service network of the base station wireless communication operation.

[0014] The processor can be configured to update the NAV based on the trigger frame, regardless of the receiver address of the trigger frame.

[0015] The processor can be configured to update the NAV based on the trigger frame, regardless of whether the trigger frame triggers a transmission from the wireless communication terminal.

[0016] When a trigger frame indicates that channel sensing is required before sending a trigger-based PPDU, the processor can be configured to update the NAV based on the trigger frame.

[0017] When the channel used for transmitting trigger-based PPDUs is detected to be busy via channel sensing, the processor can be configured to update the NAV based on the trigger frame.

[0018] The processor can be configured to update the NAV based on the time required for channel sensing and triggering frames.

[0019] According to an embodiment of the present invention, a base station wireless communication terminal communicating with a wireless communication terminal includes: a transceiver; and a processor. The processor is configured to receive physical layer data units (PPDUs) using the transceiver, and to determine whether a PPDU is a valid PPDU based on whether the PPDU was triggered by the base station wireless communication terminal.

[0020] When a PPDU is not a triggered PPDU by a base station wireless communication terminal and is transmitted via a frequency band that does not overlap with the main channel of the base station wireless communication operation's Basic Service Set (BSS), the processor can be configured to determine that the PPDU is an invalid PPDU.

[0021] When the PPDU is not a triggered PPDU and is transmitted via a frequency band that does not overlap with the main channel of the BSS operated by the base station wireless communication terminal, the processor can be configured not to issue an indicator indicating the start of PPDU reception.

[0022] When a PPDU is a triggered PPDU, even if the PPDU is transmitted through a frequency band that does not overlap with the main channel of the BSS operated by the base station wireless communication terminal, the processor can be configured to issue an indicator indicating the start of PPDU reception based on the signaling field of the PPDU.

[0023] According to an embodiment of the present invention, an operation method of a wireless communication terminal associated with a base station wireless communication terminal includes: receiving a physical layer protocol data unit (PPDU) from the base station wireless communication terminal; obtaining a trigger frame from the PPDU; and updating a network allocation vector (NAV) based on the trigger frame. At this time, the trigger frame triggers transmission of at least one wireless communication terminal.

[0024] The method may also include sending a trigger-based PPDU to the base station wireless communication terminal based on a trigger frame, regardless of the value of NAV set based on a frame sent from the basic service network operated from the base station wireless communication terminal.

[0025] NAV updates can include updating the NAV based on the trigger frame, regardless of the receiver address of the trigger frame.

[0026] NAV updates can include updating the NAV based on a trigger frame, regardless of whether the trigger frame triggers a transmission from the wireless communication terminal.

[0027] NAV updates may include updating the NAV based on a trigger frame when a trigger frame indicates that channel sensing is required before sending a trigger-based physical layer data unit (PPDU) based on the trigger frame.

[0028] NAV updates may include updating the NAV based on a trigger frame when channel busy is detected by channel sensing for transmitting trigger-based PPDUs.

[0029] NAV updates can include updating the NAV based on the time required for channel sensing and triggering frames.

[0030] Beneficial effects

[0031] Embodiments of the present invention provide a wireless communication method using network allocation vectors and a wireless communication terminal using the wireless communication 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 A wireless communication terminal according to an embodiment of the present invention is shown setting up NAV based on an immediate response request.

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

[0039] Figure 8 This illustrates a situation where a wireless communication terminal receiving a trigger frame according to an embodiment of the present invention fails to send a trigger-based PPDU based on the CS result.

[0040] Figure 9 This illustrates the operation of updating NAV by a wireless communication terminal according to another embodiment of the present invention.

[0041] Figure 10 This illustrates the operation of updating NAV by a wireless communication terminal according to another embodiment of the present invention.

[0042] Figures 11 to 12 The illustration shows a method for a wireless communication terminal according to an embodiment of the present invention to determine whether an immediate response to a trigger frame is required based on a CS requirement field.

[0043] Figures 13 to 14 The time points for setting the NAV of a wireless communication terminal according to an embodiment of the present invention are shown.

[0044] Figures 15-16 This illustrates the time point at which the wireless communication terminal sets the NAV when it updates the NAV based on the result of the CS required for transmitting the triggered PPDU according to an embodiment of the present invention.

[0045] Figures 17-18 This illustrates the time point at which the wireless communication terminal sets the NAV when it updates the NAV based on the result of the CS required for the transmission of the triggered PPDU, according to another embodiment of the present invention.

[0046] Figure 19 A method for setting the padding length of a trigger frame in a wireless communication terminal according to an embodiment of the present invention is shown.

[0047] Figures 20 to 23 This illustrates the operation of a wireless communication terminal receiving a PPDU and issuing a PHY-RXSTART.indication according to an embodiment of the present invention.

[0048] Figure 24 This illustrates the operation of a wireless communication terminal receiving a PPDU and issuing a PHY-RXSTART.indication according to another embodiment.

[0049] Figure 25 and Figure 26 The diagram illustrates the operation of a wireless communication terminal receiving a PPDU, issuing a PHY-RXSTART.indication, and updating the NAV according to another embodiment of the present invention.

[0050] Figure 27 This illustrates an operation according to another embodiment of the invention, whereby the NAV is updated based on whether the triggered PPDU was triggered by the wireless communication terminal after the wireless communication terminal receives the PPDU and issues the PHY-RXSTART.indication.

[0051] Figure 28 This illustrates an operation according to another embodiment of the invention, whereby the NAV is updated based on whether the triggered PPDU is a PPDU within the BSS after the wireless communication terminal receives the PPDU and issues the PHY-RXSTART.indication.

[0052] Figure 29 The operation of a wireless communication terminal according to an embodiment of the present invention is illustrated. Detailed Implementation

[0053] 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.

[0054] 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.

[0055] This application claims priority and benefit to Korean Patent Application No. 10-2016-0136095 (October 19, 2016), No. 10-2016-0147190 (November 6, 2016), No. 10-2017-0029524 (March 8, 2017), and No. 10-2017-0057638 (May 8, 2017), filed with the Korean Intellectual Property Office, and the embodiments and references described in the respective applications are included in the detailed description of this application.

[0056] 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.

[0057] 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.

[0058] A station (STA) is a predetermined device that includes 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.

[0059] 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.

[0060] 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).

[0061] 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.

[0062] 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.

[0063] Figure 3 This is a block diagram illustrating the configuration of station 100 according to an embodiment of the present invention.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] Figure 4 This is a block diagram illustrating the configuration of AP 200 according to an embodiment of the present invention.

[0071] like Figure 4 As illustrated, the AP 200 according to an embodiment of the present invention may include a processor 210, a transceiver 220, and a memory 260. Figure 4 In the AP 200 components, the terms related to... Figure 2 Repeated descriptions of the same or corresponding parts of the components of station 100.

[0072] refer to Figure 4 The AP 200 according to the invention includes a transceiver 220 for operating the 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.

[0073] 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 radio signal transmission / reception of AP 200 according to a first embodiment of the invention. Detailed embodiments thereof will be described below.

[0074] Figure 5 This is a schematic diagram illustrating the process of setting up the link between the STA and the AP.

[0075] 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).

[0076] STA 100, having successfully received wireless access information during the scanning step, performs the authentication step by sending an authentication request (S107a) and receiving an authentication response from AP 200 (S107b). After the authentication step is performed, STA 100 performs the association step by sending an association request (S109a) and receiving an association response from AP 200 (S109b).

[0077] 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.

[0078] 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.

[0079] 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.

[0080] Wireless communication terminals can use a Network Allocation Vector (NAV), which is an indicator of the time interval during which transmission is not permitted, to avoid transmission conflicts with other wireless communication terminals. When NAV is not 0, the wireless communication terminal can determine that the corresponding wireless medium is busy. Conversely, when NAV is 0, the wireless communication terminal can determine that the corresponding wireless medium is idle. This is called Virtual Channel Sensing (CS), where the wireless communication terminal determines whether the corresponding wireless medium can be idle based on the value of NAV. Specifically, NAV can be maintained regardless of the wireless communication terminal's Empty Channel Assessment (CCA) result. For example, when the wireless communication terminal's NAV is set, transmission through the corresponding wireless medium can be disallowed regardless of the CCA result. Furthermore, when the corresponding wireless medium is idle in the virtual CS and busy based on the CCA result, transmission through the corresponding wireless medium can be disallowed.

[0081] When a wireless communication terminal receives a valid frame from a Physical Serving Data Unit (PSDU), it can update its NAV based on the validity duration information indicated by the PSDU. Specifically, when a request is made to the wireless communication terminal in an immediate response to a Physical Layer Protocol Data Unit (PPDU) carrying the corresponding frame, the wireless communication terminal may not update its NAV. In this case, the immediate response can indicate a response sent within a predetermined time period starting from when the PPDU is received in the TXOP from which the PPDU was sent. The predetermined time can be the Short Interframe Spacing (SIFS).

[0082] Additionally, when a wireless communication terminal receives a DMG CTS frame and the receiver address of the corresponding CTS frame indicates the wireless communication terminal, the wireless communication terminal may not update the NAV. Apart from the above two cases, when the value of the DURATION field of a received frame is greater than the current NAV value, the wireless communication terminal may update the NAV based on the value of the DURATION field of the received frame.

[0083] When the PSDU includes a DURATION field, the wireless communication terminal can obtain duration information from the DURATION field to set the NAV. Alternatively, when the wireless communication terminal receives a power-saving (PS) polling frame, it can set the NAV using the sum of the time required to transmit an ACK frame and the SIFS. In this case, the wireless communication terminal can use time in microseconds. The wireless communication terminal can determine the time required for ACK frame transmission based on data rate selection rules. In this situation, when the decimal value of the sum of the time required for ACK frame transmission and the SIFS is not zero in microseconds, the wireless communication terminal can set the NAV by rounding the sum of the time required for ACK frame transmission and the SIFS to the nearest integer value.

[0084] In a particular embodiment, the wireless communication terminal can update the NAV based on the duration information indicated by TXOP_DURATION (which is a parameter of RXVECTOR) when all of the following conditions are met.

[0085] - Specify the value of TXOP_DURATION (which is a parameter of RXVECTOR).

[0086] - The wireless communication terminal did not receive a frame with a duration indicated by the DURATION field in the PPDU, which has TXOP_DURATION (a parameter of RXVECTOR).

[0087] - The value indicated by TXOP_DURATION (which is the parameter of RXVECTOR) is greater than the current NAV value.

[0088] - The PPDU carrying TXOP_DURATION (which is a parameter of RXVECTOR) is not a trigger-based PPDU triggered by the wireless communication terminal.

[0089] At this time, RXVECTOR instructs the wireless communication terminal to send information from the physical layer to the media access control (MAC) layer. Additionally, when the wireless communication terminal receives the header of a valid PPDU, it can send RXVECTOR from the physical layer to the MAC layer. At this time, the wireless communication terminal can send a PPDU reception start indicator, as described in the following embodiments. Furthermore, when all bits of the TXOP_DURATION field are 1, the wireless communication terminal can determine that the value of the TXOP_DURATION field is not specified.

[0090] Wireless communication terminals frequently communicate in dense environments. In particular, the number of wireless communication terminals communicating in environments with multiple overlapping Base Services (BSS) is increasing. When multiple BSSs overlap, the communication efficiency of the wireless communication terminal may decrease due to interference from other wireless communication terminals. Specifically, when using a frequency band through a contention process, the wireless communication terminal may even be unable to obtain a transmission opportunity due to interference from other wireless communication terminals. To address this issue, the wireless communication terminal can perform spatial reuse (SR) operations. Specifically, SR operations may include operations to access the channel depending on whether the received frame is a frame transmitted from the BSS including the wireless communication terminal or a frame transmitted from another BSS. In a particular embodiment, the channel access operation may include NAV setting, reset, and update operations. For ease of explanation, the BSS to which the wireless communication terminal belongs 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, PPDUs transmitted from within the BSS are referred to as intra-BSS PPDUs, and frames transmitted from the OBSS are referred to as OBSS PPDUs or inter-BSS PPDUs. Additionally, frames transmitted within the BSS are referred to as intra-BSS frames, and frames transmitted within the OBSS are referred to as OBSS frames or inter-BSS frames.

[0091] Specifically, the wireless communication terminal can change the NAV setting depending on whether the received frame is an intra-BSS frame or an inter-BSS frame. Specifically, the wireless communication terminal can maintain separate NAVs for intra-BSS frames and inter-BSS frames. In this case, when the wireless communication terminal receives an intra-BSS frame, it can set or update the NAV for that intra-BSS frame based on the received intra-BSS frame. Additionally, when the frame received by the wireless communication terminal may not be determined to be an intra-BSS frame or a BSS frame, the wireless communication terminal can update the NAV for inter-BSS frames based on the received frame. Furthermore, when the wireless communication terminal receives an inter-BSS frame, it can set or update the NAV for that inter-BSS frame based on the received inter-BSS frame. For ease of explanation, the NAV for intra-BSS frames is referred to as the intra NAV, and the NAV for inter-BSS frames is referred to as the regular NAV.

[0092] When a wireless communication terminal uses both internal NAV and regular NAV, it can determine the following in the virtual CS: When both internal NAV and regular NAV are 0, the wireless communication terminal can determine that the corresponding wireless medium is idle in the virtual CS. Furthermore, when at least one of internal NAV and regular NAV is not 0, the wireless communication terminal can determine that the corresponding wireless medium is being used in the virtual CS.

[0093] In a particular embodiment, a wireless communication terminal may update the NAV within the BSS based on the duration information of the frame indication included in the PSDU when all of the following conditions are met.

[0094] - The wireless communication terminal determines that the frame received by the wireless communication terminal is a BSS intraframe.

[0095] - The duration information indicated by the frame received by the wireless communication terminal is greater than the current NAV value in the BSS.

[0096] - Wireless communication terminals are not required to send an immediate response to a PPDU carrying a frame received by the wireless communication terminal.

[0097] In a particular embodiment, a wireless communication terminal may update a regular NAV based on duration information indicated by a frame included in a PSDU when all of the following conditions are met.

[0098] - The wireless communication terminal determines that the frame received by the wireless communication terminal is an inter-BSS frame.

[0099] - The duration information indicated by the frame received by the wireless communication terminal is greater than the current NAV value in the BSS.

[0100] - Wireless communication terminals are not required to send an immediate response to a PPDU carrying a frame received by the wireless communication terminal.

[0101] In a particular embodiment, the wireless communication terminal may update the NAV within the BSS using the duration information indicated by TXOP_DURATION (which is a parameter of RXVECTOR) when all of the following conditions are met.

[0102] - Specify the value of TXOP_DURATION (which is a parameter of RXVECTOR).

[0103] - The wireless communication terminal determines the PPDU carrying TXOP_DURATION (which is a parameter of RXVECTOR) as the PPDU within the BSS.

[0104] - Wireless communication terminals do not receive frames with a duration indicated by the DURATION field in a PPDU that has TXOP_DURATION (which is a parameter of RXVECTOR).

[0105] The value indicated by -TXOP_DURATION (which is a parameter of RXVECTOR) is greater than the value of NAV in the current BSS.

[0106] - The PPDU carrying TXOP_DURATION (which is a parameter of RXVECTOR) is not a trigger-based PPDU triggered by the wireless communication terminal.

[0107] In a particular embodiment, the wireless communication terminal can update the regular NAV with the duration information indicated by TXOP_DURATION (which is a parameter of RXVECTOR) when all of the following conditions are met.

[0108] - Specify the value of TXOP_DURATION (which is a parameter of RXVECTOR).

[0109] - The wireless communication terminal may identify a PPDU carrying TXOP_DURATION (which is a parameter of RXVECTOR) as an inter-BSS PPDU, or it may be uncertain whether a PPDU carrying TXOP_DURATION (which is a parameter of RXVECTOR) is an intra-BSS PPDU or an inter-BSS PPDU.

[0110] - Wireless communication terminals do not receive frames with a duration indicated by the DURATION field in a PPDU that has TXOP_DURATION (which is a parameter of RXVECTOR).

[0111] The value indicated by -TXOP_DURATION (which is an argument of RXVECTOR) is greater than the current value of the regular NAV.

[0112] When a PS polling frame is sent via HE SU PPDU, HE Extended Range SU PPDU, or HE MU PPDU, the TXOP_DURATION of the PPDU carrying the PS polling frame (which is a parameter of RXVECTOR) may not indicate duration information.

[0113] When a wireless communication terminal obtains duration information from the DURATION field of the PSDU and obtains the duration information indicated by the RXVECTOR parameter TXOP_DURATION, the wireless communication terminal can ignore the duration information indicated by TXOP_DURATION (which is a parameter of RXVECTOR).

[0114] When a wireless communication terminal resets any of the NAVs within the BSS and the regular NAVs while the values ​​of other NAVs are 0, the wireless communication terminal can initialize the physical layer's receive state. Specifically, when a wireless communication terminal resets any of the NAVs within the BSS and the regular NAVs while the values ​​of other NAVs are 0, the wireless communication terminal can send the PHY-CCARESET.request primitive from the MAC layer to the physical layer.

[0115] Figure 6 A wireless communication terminal according to an embodiment of the present invention is shown setting up NAV based on an immediate response request.

[0116] A wireless communication terminal can set the NAV based on whether the intended recipient of a received frame is itself. Specifically, when the intended recipient of a received frame is not itself, the wireless communication terminal can set the NAV based on the received frame. In this case, the wireless communication terminal can determine whether the intended recipient of the received frame is itself based on whether at least one of the frame's Receiver Address (RA) field, User Information field, and AID subfield indicates that it is itself.

[0117] Additionally, the wireless communication terminal can set the NAV based on whether the received frame requires an immediate response. Specifically, when the received frame requires an immediate response, the wireless communication terminal may not set the NAV based on the received frame. Furthermore, when the received frame does not require an immediate response and other conditions for NAV setting are met, the wireless communication terminal can set the NAV based on the received frame. The wireless communication terminal can determine whether a frame requires an immediate response based on at least one of the frame type, subtype, and ACK policy subfield.

[0118] exist Figure 6In this embodiment, the AP sends a multi-user (HE MU) PPDU from the first station STA1 to the third station STA3. At this time, the AP sends frames requiring ACK to each of the first station STA1 and the second station STA2. Additionally, the AP sends frames not requiring ACK to the third station STA3. The first station STA1 and the second station STA2 send ACKs to the AP via triggered PPDUs. At this time, the third station STA3 sets the NAV within its BSS.

[0119] Figure 7 The trigger frame format according to an embodiment of the present invention is shown.

[0120] A wireless communication terminal can trigger transmissions by one or more other wireless communication terminals by sending a trigger frame. Specifically, the wireless communication terminal sends a trigger frame to the receiving wireless communication terminal to trigger an uplink (UL) MU transmission. The receiving wireless communication terminal can perform UL MU transmissions using a trigger-based PPDU. The trigger frame may include information required to send the trigger-based PPDU.

[0121] The trigger frame may include a frame control field indicating information about frame control. Additionally, the trigger frame may include a DURATION field indicating duration information of the NAV setting. Furthermore, the trigger frame may include an RA field indicating the receiver address. Additionally, the trigger frame may include a TA field indicating the transmitter address. Moreover, the trigger frame may include a common information field indicating information typically applied to at least one wireless communication terminal that triggers uplink transmission. Additionally, the trigger frame may include a user information field indicating information applied to each of the at least one wireless communication terminal that triggers uplink transmission. Furthermore, the trigger frame may include a padding field containing padding bits. Additionally, the trigger frame may include an FCS field to confirm whether the trigger frame includes error bits. Specifically, the format of the trigger frame may be similar to... Figure 7 Same as shown in (a).

[0122] The common information fields may include a trigger type field indicating the type of the trigger frame. Additionally, the common information fields may include a length field indicating the length of the trigger frame. Furthermore, the common information fields may include a concatenation indication field, indicating whether the concatenation transmission process continues in the trigger frame. Additionally, the common information fields may include a CS required field, indicating whether a CS is required when sending a response to the trigger frame. In this case, the response to the trigger frame can be a trigger-based PPDU. Furthermore, the common information fields may include a BW field, indicating information about the frequency band used to send the response to the trigger frame. Additionally, the common information fields may include GI and LTF type fields, indicating information about the GI and LTF used to send the response to the trigger frame. Additionally, the common information fields may also include a MU-MIMO LTF mode field, indicating information about the MU-MIMO and LTF modes used to send the response to the trigger frame. Additionally, the common information fields may include an HE-LTF symbol count field, indicating the number of LTF symbols used to send the response to the trigger frame. Furthermore, the common information fields may include an STBC field, indicating whether STBC is used to send the response to the trigger frame. Additionally, the common information field may include an LDPC additional symbol field, indicating whether LDPC additional symbols are used to transmit a response to the trigger frame. Furthermore, the common information field may include an AP Tx power field indicating the transmission power used to transmit the trigger frame. Additionally, the common information field may include a packet spread field, indicating the duration of the packet spread portion used to transmit the response to the trigger frame. Additionally, the common information field may include a spatial reuse field, indicating the value of the SR field of the HE SIG-A field of the PPDU used to transmit the response to the trigger frame. Furthermore, the common information field may include a Doppler field, indicating whether the Doppler effect applies to the transmission of the response to the trigger frame. Finally, the common information field may include a trigger-related common information subfield, which is determined based on the type of trigger frame.

[0123] As described above, the trigger frame may include a CS required field, indicating whether CS is required when sending a response to the trigger frame. When the CS required field requires the wireless communication terminal to consider the CS result when determining whether to respond to the trigger frame, the wireless communication terminal indicated by the user information field of the trigger frame performs CS when sending a trigger-based PPDU based on the trigger frame. In this case, CS includes virtual CS and physical CS. Moreover, physical CS may indicate energy detection (ED). Specifically, ED may include CCA. When the corresponding channel is busy based on the CS result, the wireless communication terminal does not send a trigger-based PPDU. When the corresponding channel is idle based on the CS result, the wireless communication terminal may send a trigger-based PPDU. When the wireless communication terminal determines that NAV is not set and determines that the corresponding channel is idle through ED, the wireless communication terminal can determine that the corresponding channel is idle. When the CS required field does not require the wireless communication terminal to consider the CS result when determining whether to respond to the trigger frame, the wireless communication terminal may send a trigger-based PPDU based on the trigger frame without CS. In this case, the wireless communication terminal sending the trigger-based PPDU is the wireless communication terminal indicated by the user information field of the trigger frame.

[0124] Figure 8 This illustrates a situation where a wireless communication terminal receiving a trigger frame according to an embodiment of the present invention fails to send a trigger-based PPDU based on the CS result.

[0125] As described above, the wireless communication terminal requested to respond immediately to a frame does not update the NAV. However, when the CS request field requires the CS to consider the CS result when the wireless communication terminal determines whether to respond to the trigger frame, the wireless communication terminal indicated by the user information field of the trigger frame performs the CS when sending a trigger-based PPDU based on the trigger frame. In this case, if the CS result indicates that the channel for sending the trigger-based PPDU is busy, the wireless communication terminal may not send the trigger-based PPDU. Therefore, even the wireless communication terminal receiving the request for an immediate response to a frame may not send an immediate response according to the value of the CS request field of the trigger frame. The wireless communication terminal receiving the request for an immediate response does not send an immediate response, but the NAV is not set. Therefore, channel access fairness between wireless communication terminals may be violated. In addition, the wireless communication terminal receiving the request for an immediate response may interfere with the transmission of trigger-based PPDUs by another wireless communication terminal that is also receiving the request for an immediate response.

[0126] exist Figure 8In embodiments (a) and (b), the AP sends a trigger frame to stations 1 through 3. At this time, the CS request field of the trigger frame needs to take the CS result into account when determining the transmission of the trigger-based PPDU based on the trigger frame. Stations 1 through 3 perform CS before sending the trigger-based PPDU based on the trigger frame. At this time, stations 1 through 2 determine that the channel to be used for sending the trigger-based PPDU is idle. Station 5, adjacent to station 3, is using the channel allocated to station 3. Therefore, station 3 determines that the channel to be used for sending the trigger-based PPDU is busy. Therefore, stations 1 through 2 send the trigger-based PPDU, and station 3 fails to send the trigger-based PPDU. At this time, because stations 1 through 3 receive a request for an immediate response, stations 1 through 3 do not update the NAV based on the trigger frame. Station 4, which was not indicated by the trigger frame, updates the NAV based on the trigger frame.

[0127] The third station, STA3, whose NAV is not set, can perform CCA again and attempt transmission while the first station, STA1, and the second station, STA2, are performing trigger-based PPDU transmissions. Therefore, the transmission by the third station, STA3, can interrupt the trigger-based PPDU transmissions from the first station, STA1, to the second station, STA2. Furthermore, because the NAV is set, the fourth station, STA4, may not access the channel, potentially resulting in a disadvantageous channel access opportunity compared to the third station, STA3. Therefore, a method for setting the NAV to address this issue is needed. (See reference...) Figure 9 and Figure 10 This will be described.

[0128] Figure 9 This illustrates the operation of updating NAV by a wireless communication terminal according to another embodiment of the present invention.

[0129] When a wireless communication terminal that receives a request for an immediate response to a frame fails to send an immediate response due to a CS (Confirmation of Response) result, the wireless communication terminal may update the NAV (Network Access Variable) based on the frame or a PPDU (Private Distribution Variable) including the frame. Specifically, the wireless communication terminal receives a trigger frame, and when the trigger frame determines that a trigger-based PPDU transmission is required, it requests consideration of the CS result. Due to the CS result, the wireless communication terminal may not send a trigger-based PPDU. In this case, the wireless communication terminal may update the NAV based on the trigger frame or a PPDU including the trigger frame. When the wireless communication terminal determines that the channel is idle via CS, it may send a trigger-based PPDU. In this case, because the wireless communication terminal receives a request for an immediate response and determines to send a trigger-based PPDU based on the CS result, the wireless communication terminal may not update the NAV. Furthermore, when a trigger frame is received and the trigger frame determines that a trigger-based PPDU transmission does not require consideration of the CS result, the wireless communication terminal may not update the NAV because the wireless communication sends the trigger-based PPDU without performing a CS.

[0130] exist Figure 9 In embodiments (a) and 9(b), the AP sends a trigger frame to stations 1 through 3. At this time, the CS request field of the trigger frame needs to take the CS result into account when determining the transmission of the trigger-based PPDU based on the trigger frame. Stations 1 through 3 perform CS before sending the trigger-based PPDU based on the trigger frame. At this time, stations 1 through 2 determine that the channel to be used for sending the trigger-based PPDU is idle. Additionally, station 5, adjacent to station 3, is using the channel allocated to station 3. Therefore, station 3 determines that the channel to be used for sending the trigger-based PPDU is busy. As a result, stations 1 through 2 send the trigger-based PPDU, and station 3 fails to send the trigger-based PPDU. At this time, because stations 1 through 3 receive requests for an immediate response, they do not update the NAV based on the trigger frame or the PPDU including the trigger frame. However, because station 3 fails to send the trigger-based PPDU, station 3 updates the NAV based on the trigger frame or the PPDU including the trigger frame. The fourth station STA4, which is not indicated by a trigger frame, updates the NAV based on the trigger frame or a PPDU that includes the trigger frame.

[0131] Figure 10 This illustrates the operation of updating NAV by a wireless communication terminal according to another embodiment of the present invention.

[0132] The wireless communication terminal receiving the trigger frame can update the NAV based on the trigger frame. In this case, when the NAV of the wireless communication terminal is set via a BSS intraframe, the wireless communication terminal can send a trigger-based PPDU, regardless of the NAV value. Furthermore, regardless of whether the trigger frame triggers uplink transmission of the wireless communication terminal, the wireless communication terminal can update the NAV based on the trigger frame. In this embodiment, even when the trigger frame requires an immediate response, the wireless communication terminal receiving the trigger frame can still update the NAV based on the trigger frame.

[0133] Specifically, a wireless communication terminal that receives a trigger frame within the BSS can update the NAV within the BSS based on the trigger frame. In a particular embodiment, the wireless communication terminal can update the NAV within the BSS based on the frame when all of the following conditions are met.

[0134] The wireless communication terminal determines that the frame received by the wireless communication terminal is a BSS intraframe.

[0135] The duration information indicated by the frame received by the wireless communication terminal is greater than the current NAV value in the BSS.

[0136] Wireless communication terminals are not required to send an immediate response to a PPDU carrying a frame received by the wireless communication terminal or a frame that is a trigger frame.

[0137] Furthermore, a wireless communication terminal receiving an inter-BSS trigger frame can update the regular NAV based on the trigger frame. A wireless communication terminal can update the regular NAV based on a frame when all of the following conditions are met.

[0138] - The wireless communication terminal can determine whether the frame received by the wireless communication terminal is an inter-BSS frame or cannot determine whether the received frame is an inter-BSS frame or an intra-BS frame.

[0139] - The duration information indicated by the frame received by the wireless communication terminal is greater than the current inter-BSS NAV value.

[0140] - The wireless communication terminal is not required to send an immediate response to the PPDU carrying the frame received by the wireless communication terminal, or the frame received by the wireless communication terminal is a trigger frame.

[0141] exist Figure 10In embodiments (a) and 10(b), the AP sends a trigger frame to stations 1 through 3. At this time, the CS request field of the trigger frame needs to take into account the CS result when determining the transmission of the trigger-based PPDU based on the trigger frame. Because stations 1 through 3 receive an immediate response request but have already received the trigger frame, they update the NAV based on the trigger frame. Stations 1 through 3 perform the CS before sending the trigger-based PPDU based on the trigger frame. At this time, stations 1 through 2 determine that the channel to be used for sending the trigger-based PPDU is idle. Specifically, stations 1 through 2 do not consider the NAV set by the BSS intraframe. Additionally, station 5, adjacent to station 3, is using the channel allocated to station 3. Therefore, station 3 determines that the channel to be used for sending the trigger-based PPDU is busy. As a result, stations 1 through 2 send the trigger-based PPDU, and station 3 fails to send the trigger-based PPDU. The fourth station, STA4, updates the NAV based on the trigger frame or a PPDU that includes the trigger frame.

[0142] In another embodiment, the wireless communication terminal may modify a method to determine whether to request an immediate response instead of an NAV update condition. (See also...) Figures 11 to 12 This will be described.

[0143] Figures 11 to 12 The illustration shows a method for a wireless communication terminal according to an embodiment of the present invention to determine whether an immediate response to a trigger frame is required based on a CS request field.

[0144] When the CS requirement field does not need to consider the CS result when determining the transmission of a trigger-based PPDU based on the trigger frame, the wireless communication terminal can determine that an immediate response to the trigger frame is required. In a specific embodiment, when the CS requirement field needs to consider the CS result when determining the transmission of a trigger-based PPDU based on the trigger frame, the wireless communication terminal can determine that an immediate response to the trigger frame is required based on the CS result. Specifically, when the channel is not determined to be idle based on the CS result, the wireless communication terminal can determine that an immediate response to the trigger frame is not required. Furthermore, when the channel is determined to be idle based on the CS result, the wireless communication terminal can determine that an immediate response to the trigger frame is required. Specifically, the wireless communication terminal can, as follows: Figure 11 The same determination is made in the middle.

[0145] In another specific embodiment, when the CS requirement field needs to consider the CS result when determining the transmission of a trigger-based PPDU based on the trigger frame, the wireless communication terminal can determine that it does not need to respond to the trigger frame immediately. In this case, regardless of the NAV set by the BSS frame, the wireless communication terminal can send the trigger-based PPDU. Specifically, the wireless communication terminal can do as follows: Figure 12 The same determination is made in the middle.

[0146] pass Figures 13 to 18 This will describe the operational time points related to the NAV settings of the wireless communication terminal.

[0147] Figures 13 to 14 The time points for setting the NAV of a wireless communication terminal according to an embodiment of the present invention are shown.

[0148] When the MAC layer receives a PPDU reception end indicator from the physical layer, indicating the end of PPDU reception, the wireless communication terminal can update the NAV. At this time, the PPDU reception end indicator can be a PHY-RXEND.indication primitive. Figure 13 In this embodiment, when the reception of the PPDU ends, the MAC sublayer management entity (MLME) of the wireless communication terminal receives the PHY-RXEND.indication primitive from the physical layer. When the PHY-RXEND.indication primitive is received, the MLME of the wireless communication terminal sets the NAV.

[0149] When a wireless communication terminal receives a PPDU reception end indicator before the expected PPDU reception end time, the wireless communication terminal can update the NAV at the time that is expected to be the PPDU reception end time. Figure 14 In one embodiment, the wireless communication terminal fails to receive the PPDU. Therefore, the physical layer management entity (PLME) of the wireless communication terminal delivers the PHY-RXEND.indication primitive to the MAC layer earlier than the predetermined time point of the PPDU receiver. At this time, the PLME of the wireless communication terminal updates the NAV at the predetermined time point of the PPDU receiver, rather than at the time point of receiving the PHY-RXEND.indication primitive.

[0150] The wireless communication terminal can operate in this manner not only when using a single NAV, but also when using a BSS-internal NAV and a regular NAV. Furthermore, the wireless communication terminal can operate in this manner not only when obtaining duration information from a frame, but also when obtaining duration information from the signaling field of a PPDU.

[0151] Figures 15-16This illustrates the time point at which the wireless communication terminal sets the NAV when it updates the NAV based on the result of the CS required for transmitting the triggered PPDU according to an embodiment of the present invention.

[0152] The wireless communication terminal can set the NAV based on the result of the CS required for the triggered PPDU transmission in the above embodiments. In this case, the CS of the wireless communication terminal requires a certain amount of time. Specifically, the predetermined time can be SIFS. Therefore, the wireless communication terminal can update the NAV after the CS required for the triggered PPDU transmission. Specifically, the wireless communication terminal can update the NAV after the time from receiving the PPDU reception end indicator to the end of the CS.

[0153] When a wireless communication terminal receives a trigger frame requesting a CS to perform a trigger-based PPDU transmission, the wireless communication terminal can update the NAV according to the above embodiments. Specifically, when the trigger frame CS received by the wireless communication terminal requests a 1, the wireless communication terminal can update the NAV according to the above embodiments. Additionally, when the wireless communication terminal is the intended receiver of the trigger frame, the wireless communication terminal can update the NAV according to the above embodiments. Alternatively, when scheduling the transmission of the wireless communication terminal, the wireless communication terminal can update the NAV according to the above embodiments.

[0154] Additionally, the wireless communication terminal can update the NAV value by subtracting the time consumed by the CS from the duration information. Furthermore, the wireless communication terminal can obtain the duration information from the frame. In another specific embodiment, the wireless communication terminal can obtain the duration information from the signaling field of the PPDU.

[0155] exist Figure 15 In this embodiment, when the time required by the CS of the wireless communication terminal has elapsed since the PHY-RXEND.indication primitive was received, the wireless communication terminal updates the NAV. At this time, the wireless communication terminal updates the value of NAV with the value obtained by subtracting the time required for CS from the duration information. Figure 16 In this embodiment, the wireless communication terminal updates NAV after receiving the PHY-RXEND.indication primitive from SIFS. At this time, the wireless communication terminal updates the value of NAV with the value obtained by subtracting SIFS from the duration information.

[0156] Figures 17-18 This illustrates the time point at which the wireless communication terminal sets the NAV when it updates the NAV based on the result of the CS required for the triggered PPDU transmission, according to another embodiment of the invention.

[0157] Reference Figure 15 and Figure 16In the described embodiment, the wireless communication terminal can update the NAV value to the time obtained by subtracting the time required for CS from the time indicated by the duration information. Specifically, the time required for CS can be SIFS. In another specific embodiment, the wireless communication terminal sending the trigger frame can set the time indicated by the duration information to the time obtained by subtracting the time required for CS from the time required for transmission protection. Specifically, the wireless communication terminal sending the trigger frame can set the DURATION field of the frame to the time obtained by subtracting the time required for CS from the time required for transmission protection. Furthermore, the wireless communication terminal sending the trigger frame can set the TXOP_DURATION field of the signaling field of the PPDU to the time obtained by subtracting the time required for CS from the time required for transmission protection. In this case, the time required for CS can be SIFS. The NAV update time point and other operations of the wireless communication terminal receiving the trigger frame can be referenced. Figures 15 to 16 The same applies to those described in the embodiments. Additionally, the wireless communication terminal receiving the trigger frame can operate when the time point for setting the NAV is the time point at which information indicating completion of PPDU reception is received.

[0158] exist Figure 17 In this embodiment, the wireless communication terminal sending the trigger frame sets the CS request field to 1 and sets the duration information to the time obtained by subtracting the CS requirement time from the transmission protection time. The wireless communication terminal receiving the trigger frame updates the NAV based on the CS result. The wireless communication terminal receiving the trigger frame updates the NAV after SIFS from the start of receiving the PPDU. At this time, the wireless communication terminal receiving the trigger frame updates the time indicated by the duration information to the value of NAV. Figure 18 In the embodiments, the operation of the wireless communication terminal receiving the trigger frame is similar to... Figure 17 The operation is the same as in the embodiment. However, the wireless communication terminal operates as if the time point used to set the NAV is the time point at which information indicating completion of PPDU reception is received.

[0159] Reference Figures 6 to 18In the described embodiments, the wireless communication terminal can update the NAV based on the MAC header of the trigger frame. Specifically, the wireless communication terminal can update the NAV based on the frame control field, the type of the frame control field, and the subtype subfield of the MAC header. Additionally, when the wireless communication terminal corresponds to the receiver expected by the trigger frame, the wireless communication terminal can update the NAV based on the trigger frame. In this case, the wireless communication terminal can determine whether it corresponds to the receiver expected by the trigger frame based on whether the user information field of the trigger frame indicates the wireless communication terminal. Specifically, when the user information field of the trigger frame indicates the wireless communication terminal, the wireless communication terminal can determine that it corresponds to the receiver expected by the trigger frame. In a particular embodiment, when the user information field of the trigger frame indicates the associated ID (AID) of the wireless communication terminal, the wireless communication terminal can determine that it corresponds to the receiver expected by the trigger frame. In this case, the user information field can indicate a portion of the wireless communication terminal's AID. For example, the user information field can indicate the least significant bit (LSB) of the 12 bits of the wireless communication terminal's AID.

[0160] In addition, when a trigger frame triggers a wireless communication terminal belonging to a BSS, the wireless communication terminal can update the BSS NAV based on the trigger frame.

[0161] When the receiver address of a frame received by a wireless communication terminal is not that of the wireless communication terminal, the wireless communication terminal can update the NAV based on the received frame. When a trigger frame triggers transmissions by multiple wireless communication terminals, the wireless communication terminal sending the trigger frame can set the receiver address of the trigger frame to the broadcast address. Furthermore, when a trigger frame triggers transmissions by any one wireless communication terminal, the wireless communication terminal sending the trigger frame can set the receiver address of the trigger frame to the address of any one of the wireless communication terminals. In this case, whether the wireless communication terminal receiving the trigger frame can set the NAV based on the trigger frame may be a question. When the wireless communication terminal receiving the trigger frame does not set the NAV based on the trigger frame, refer to... Figure 8 The problem described may occur. Therefore, the wireless communication terminal receiving the trigger frame can set the NAV based on the trigger frame, regardless of the receiver address of the trigger frame.

[0162] Figure 19 A method for setting the padding length of a trigger frame in a wireless communication terminal according to an embodiment of the present invention is shown.

[0163] For reference Figure 7The trigger frame may include a padding field. Specifically, the wireless communication terminal sending the trigger frame may insert a padding field into the trigger frame to help the wireless communication terminal receiving the trigger frame ensure the timing of processing the trigger frame. In this case, the padding field may be a field with a length of 2 or more octets. Furthermore, the start of the padding field may be indicated by a predetermined value. The predetermined value may be 0xFFF. Additionally, the remaining bits of the padding field may all be 1s. A wireless communication terminal other than the base station wireless communication terminal may send necessary padding length information, which is information related to the length of the padding field required by the base station wireless communication terminal. The base station wireless communication terminal may set the padding field of the trigger frame based on the necessary padding length information. The wireless communication terminal other than the base station wireless communication terminal may be a non-AP wireless communication terminal. Specifically, the wireless communication terminal other than the base station wireless communication terminal may send necessary padding length information to the base station wireless communication terminal during the association process. For example, the wireless communication terminal other than the base station wireless communication terminal may send necessary padding length information by at least one of a probe request frame and an association request frame. The necessary padding length information may indicate the duration of the padding field. For example, the necessary padding length information may indicate, for example, the duration of the padding field. Figure 18 m PAD The duration of any one of 0µs, 8µs, and 16µs. In a particular embodiment, the base station wireless communication terminal can use... Figure 18 The equation setting determines the length of the padding field in the trigger frame transmitted via any of the non-HT PPDU, HT PPDU, and VHT PPDU. Furthermore, the base station wireless communication terminal can use... Figure 18 The equation sets the length of the padding field in the trigger frame sent via HE PPDU. In this case, N DBPS It can indicate the maximum number of data bits per symbol, and N DBPS,SHORT It can indicate the number of data bits less than the number of each symbol.

[0164] When a trigger frame triggers transmissions from multiple wireless communication terminals, the wireless communication terminals can set the length of the padding field of the trigger frame based on the longest length of the padding field required by the multiple wireless communication terminals. Specifically, when a trigger frame triggers transmissions from multiple wireless communication terminals, the wireless communication terminals can set the length of the padding field of the trigger frame based on necessary padding length information indicating the longest duration among the multiple necessary padding lengths sent by the multiple wireless communication terminals.

[0165] A trigger frame can trigger random access from wireless communication terminals associated with the base station's wireless communication terminal. Furthermore, a trigger frame can trigger transmissions from wireless communication terminals not associated with the base station's wireless communication terminal. Specifically, the base station's wireless communication terminal sets the user information field of the trigger frame to a predetermined value to trigger random access from either associated or unassociated wireless communication terminals. In this case, there is a problem regarding the length of the padding field in the trigger frame set by the base station's wireless communication terminal.

[0166] When a trigger frame triggers random access by an associated wireless communication terminal, the base station wireless communication terminal can set the length of the padding field based on necessary padding length information, which indicates the longest length among the necessary padding lengths of the multiple wireless communication terminals receiving the trigger frame. In this case, the multiple wireless communication terminals receiving the trigger frame can be multiple wireless communication terminals that trigger uplink transmission. Furthermore, the multiple wireless communication terminals receiving the trigger frame can be wireless communication terminals associated with the base station wireless communication terminal that sent the trigger frame. When a trigger frame triggers random access by an unassociated wireless communication terminal, the base station wireless communication terminal can set the length of the padding field based on the longest length of the necessary padding length information. For example, when triggering... Figure 18 In the embodiment of the random access of the wireless communication terminal, the base station wireless communication terminal can set m to 4.

[0167] When a valid PPDU is received, the wireless communication terminal can begin processing the frames included in the received PPDU. Specifically, when the wireless communication terminal receives a PPDU, its MLME receives a PPDU reception start indicator that instructs the physical layer to begin receiving the valid PPDU. In a particular embodiment, after the MLME of the wireless communication terminal receives the PPDU reception start indicator, the MLME can receive the aforementioned RXVECTOR from the physical layer. The wireless communication terminal can determine whether it has begun receiving a valid PPDU based on whether the base station wireless communication terminal has received the header of the valid PPDU. Specifically, the wireless communication terminal can determine whether it has begun receiving a valid PPDU based on whether the base station wireless communication terminal has received the format of the valid PPDU. The PPDU reception start indicator can be a PHY-RXSTART.indication primitive. Specifically, when the wireless communication terminal effectively receives the header of the PPDU, it can issue a PHY-RXSTART.indication primitive. In a particular embodiment, the wireless communication terminal can issue the PHY-RXSTART.indication primitive after receiving the signaling field of the PPDU. In this case, the signaling field can include the HT SIG field, VHT SIG, and HE SIG.

[0168] Additionally, the wireless communication terminal can issue the PHY-RXSTART.indication primitive and determine that the wireless media transmitting the corresponding PPDU is busy during the period indicated by the LENGTH and DATARATE fields of the signaling field of the corresponding PPDU. After the wireless communication terminal issues the PHY-RXSTART.indication primitive, even if PPDU reception is lost or format violation occurs, the wireless communication terminal can determine that the wireless media transmitting the PPDU is busy. A lost PPDU reception may indicate a problem with the PHY-RXEND.indication(CarrierLost) primitive. Furthermore, a format violation may also indicate a problem with the PHY-RXEND.indication(FormatViolation) primitive.

[0169] Furthermore, after the MLME of the wireless communication terminal receives the PPDU reception start indicator, the MLME can process the frame included in the PPDU. Specifically, after the MLME of the wireless communication terminal receives the PPDU reception start indicator, the wireless communication terminal can perform NAV-related operations and frame-related operations. In a particular embodiment, NAV-related operations may include at least one of NAV setting and NAV reset. Additionally, NAV-related operations may include setting the NAV based on TXOP_DURATION obtained by the wireless communication terminal from HE-SIG-A. Frame-related operations may include at least one of frame reception and frame decoding. Therefore, when no PPDU reception start indicator is issued, the wireless communication terminal may not perform NAV setting-related operations based on the PPDU.

[0170] Figures 20 to 23 This illustrates the operation of a wireless communication terminal receiving a PPDU and issuing a PHY-RXSTART instruction according to an embodiment of the present invention.

[0171] The primary channel indicates the frequency band commonly used by wireless communication terminals included in the BSS. Specifically, the primary channel may have a predetermined frequency bandwidth. The predetermined frequency bandwidth may be 20MHz. Furthermore, in this specification, the primary channel may indicate the primary channel of the BSS to which the wireless communication terminal belongs. Therefore, when MU transmission via OFDMA is not used, the wireless communication terminal can ignore PPDUs received not through a frequency band overlapping with the primary channel. This is because it can be determined that the corresponding PPDU is not a PPDU sent to the wireless communication terminal. Additionally, when the primary channel is idle, the wireless communication terminal can associate the primary channel with a secondary channel.

[0172] exist Figure 20In embodiment (a), the wireless communication terminal receives PPDUs through a main channel with a bandwidth of 20 MHz. Figure 20 In embodiment (b), the wireless communication terminal receives PPDUs via frequency bands P20, S20, and S40, including a main channel P20 with a bandwidth of 20 MHz. Figure 20 In both embodiments (a) and (b), the wireless communication terminal receives the PPDU via a frequency band overlapping with the main channel. Therefore, the wireless communication terminal determines whether the PPDU includes a valid signaling field. When the PPDU includes a valid signaling field, the wireless communication terminal issues the PHY-RXSTART.indication primitive.

[0173] When using MU transmission with OFDMA, PPDUs (Programmable Component Distributed Duties) can be received using a frequency band that does not overlap with the main channel. Specifically, in MU transmission using OFDMA, transmission through the main channel may fail, and PPDUs can be received using a secondary channel. Therefore, even when the base station wireless communication terminal receives a trigger-based PPDU through a frequency band other than the one overlapping with the main channel, the base station wireless communication terminal can determine that a valid PPDU has been received. When the base station wireless communication terminal receives a trigger-based PPDU, it can determine whether it has received a valid PPDU, regardless of the frequency band through which the trigger-based PPDU was transmitted. Specifically, when the base station wireless communication terminal receives a PPDU through a frequency band that does not overlap with the main channel and does not receive trigger-based PPDUs, it can determine that it has received an invalid PPDU. When the base station wireless communication terminal receives a PPDU through a frequency band that does not overlap with the main channel and does not receive trigger-based PPDUs, it may not issue a PPDU reception start indicator.

[0174] exist Figure 21 In part (a) of the embodiment, the AP receives PPDUs other than the HE-triggered PPDUs via a secondary channel S20 in addition to the primary channel P20. Figure 21 In part (b) of the embodiment, the AP receives HE-triggered PPDUs via a secondary channel S20 in addition to the primary channel P20. Figure 21 In the embodiment of part (a), because the PPDU received by the AP is not based on a triggered PPDU, the AP determines that an invalid PPDU has been received. The AP does not issue the PHY-RXSTART.indication primitive. Figure 21In part (b) of the embodiment, since the PPDU received by the AP is based on a triggered PPDU, the AP determines that a valid PPDU has been received. Therefore, when the signaling field of the PPDU is valid, the AP issues the PHY-RXSTART.indication primitive.

[0175] When a wireless communication terminal other than the base station wireless communication terminal receives a trigger-based PPDU, the wireless communication terminal can determine that the PPDU was not sent to the wireless communication terminal. This is because a wireless communication terminal other than the base station wireless communication terminal can trigger uplink transmission without sending a trigger frame. Therefore, a wireless communication terminal other than the base station wireless communication terminal can ignore PPDUs that are not received through a frequency band overlapping with the main channel. Specifically, a wireless communication terminal other than the base station wireless communication terminal can determine that a PPDU not received through a frequency band overlapping with the main channel is not a valid PPDU. Therefore, when a wireless communication terminal other than the base station wireless communication terminal receives a PPDU that is not received through a frequency band overlapping with the main channel, the wireless communication terminal does not need to issue a PPDU reception start indicator.

[0176] exist Figure 22 In this embodiment, the non-AP station / non-AP STA receives HE-triggered PPDUs via the secondary channel S20, which is in addition to the primary channel P20. Because the non-AP station / non-AP STA receives PPDUs via the frequency band S20, which does not overlap with the primary channel P20, the non-AP station / non-AP STA determines that it has received an invalid PPDU. Therefore, the non-AP station / non-AP STA does not issue the PHY-RXSTART.indication primitive.

[0177] As described above, even when the base station wireless communication terminal receives a trigger-based PPDU as an inter-BSS PPDU via a frequency band that does not overlap with the main channel, the base station wireless communication terminal can determine whether the reception of the trigger-based PPDU is valid. In this case, the base station wireless communication terminal can update the regular NAV based on the trigger-based PPDU as an inter-BSS PPDU. Furthermore, when the base station wireless communication terminal receives a trigger-based PPDU as an intra-BSS PPDU via a frequency band that does not overlap with the main channel, the base station wireless communication terminal can determine whether the reception of the trigger-based PPDU is valid. Therefore, the base station wireless communication terminal can update the intra-BSS NAV based on the trigger-based PPDU. In such an embodiment, the base station wireless communication terminal can determine whether the PPDU received by the base station wireless communication terminal is an inter-BSS PPDU or an intra-BSS PPDU based on the BSS color indicated by the PPDU. Specifically, when the BSS color indicated by the PPDU received by the base station wireless communication terminal is equal to the BSS color of the BSS operated by the base station wireless communication terminal, the base station wireless communication terminal can determine that the received PPDU is an intra-BSS PPDU.

[0178] exist Figure 23 In this embodiment, the first AP 1 receives HE-based triggered PPDUs (PPDUs) not caused by the first AP 1 via the secondary channel S20, which is in addition to the primary channel P20. Because the PPDUs received by the first AP 1 are trigger-based, the first AP 1 determines that it has received a valid PPDU. Therefore, when the signaling field of the PPDU is valid, the AP issues the PHY-RXSTART.indication primitive. At this time, the first AP 1 updates the NAV based on the HE-based triggered PPDU. When the first AP 1 uses both the regular NAV and the BSS-internal NAV, the first AP 1 updates the regular NAV.

[0179] Reference Figures 21 to 23 In the described embodiments, even when a trigger-based PPDU is received via a secondary channel that does not overlap with the primary channel, the base station wireless communication terminal can set the NAV. In this case, even when the primary channel is idle, the base station wireless communication terminal can choose not to use the primary channel. Therefore, the efficiency of spatial reuse may be reduced. Furthermore, since wireless communication terminals other than the base station wireless communication terminal do not set the NAV when receiving a trigger-based PPDU via the secondary channel, the base station wireless communication terminal may be at a disadvantage in channel access contention compared to other wireless communication terminals. Additionally, compared to wireless communication terminals using only a frequency band with a 20MHz bandwidth, the base station wireless communication terminal may be at a disadvantage in channel access contention. To address this issue, reference will be made to 24 to... Figure 29Embodiments of the present invention are described.

[0180] In a specific embodiment, when a base station wireless communication terminal receives a trigger-based PPDU, the base station wireless communication terminal can determine whether a valid PPDU has been received based on the characteristics of the trigger-based PPDU. (See reference...) Figure 24 This will be described.

[0181] Figure 24 This illustrates the operation of a wireless communication terminal receiving a PPDU and issuing a PHY-RXSTART.indication according to another embodiment.

[0182] When a base station wireless communication terminal receives a trigger-based PPDU triggered by itself, it can determine whether it has received a valid PPDU, regardless of the channel through which it transmitted the PPDU. Specifically, when a base station wireless communication terminal receives a trigger-based PPDU, it can issue a PPDU reception start indicator, regardless of the channel through which it transmitted the PPDU. Furthermore, when a base station wireless communication terminal receives PPDUs other than those triggered by itself through a frequency band that does not overlap with the main channel, it can determine that it has received an invalid PPDU. Specifically, when a base station wireless communication terminal receives PPDUs other than those triggered by itself through a frequency band that does not overlap with the main channel, it may not issue a PPDU reception start indicator.

[0183] Furthermore, when a base station wireless communication terminal receives a trigger-based PPDU (Programmable Component Distributed Duty) as an intra-BSS PPDU, the base station wireless communication terminal can determine whether it has received a valid PPDU, regardless of the channel through which it transmitted the trigger-based PPDU. Specifically, when the base station wireless communication terminal receives a trigger-based PPDU as an intra-BSS PPDU, it can issue a PPDU reception start indicator, regardless of the channel through which it transmitted the trigger-based PPDU. Additionally, when the base station wireless communication terminal receives a trigger-based PPDU as an inter-BSS PPDU via a frequency band that does not overlap with the main channel, it can determine that it has received an invalid PPDU. Specifically, when the base station wireless communication terminal receives a trigger-based PPDU as an inter-BSS PPDU via a frequency band that does not overlap with the main channel, it may not issue a PPDU reception start indicator.

[0184] exist Figure 24In embodiment (a), the AP receives trigger-based PPDUs (PPDUs) that are within the BSS via the secondary channel S20 instead of the primary channel P20. Because the AP receives trigger-based PPDUs, which are within the BSS, it determines whether a valid PPDU has been received. When it is determined that the AP has received a valid PPDU, the AP issues the PHY-RXSTART.indication primitive. Figure 24 In embodiment (b), the AP receives trigger-based PPDUs via the secondary channel S20 instead of the primary channel P20; these are inter-BSS PPDUs. Because the AP is not receiving trigger-based PPDUs as intra-BSS PPDUs, it is uncertain whether a valid PPDU has been received. The AP does not issue the PHY-RXSTART.indication primitive. Through these embodiments, the base station wireless communication terminal can prevent channel access from being interrupted by trigger-based PPDUs sent from other BSSs and the base station wireless communication terminal, and can also prevent the base station wireless communication terminal from failing to receive trigger-based PPDUs sent to it.

[0185] In a particular embodiment, when a base station wireless communication terminal receives a trigger-based PPDU, the base station wireless communication terminal can determine whether to update the valid NAV based on the characteristics of the trigger-based PPDU. (See reference...) Figures 25 to 28 This will be described.

[0186] Figure 25 and Figure 26 The diagram illustrates the operation of a wireless communication terminal receiving a PPDU, issuing a PHY-RXSTART.indication, and updating the NAV according to another embodiment of the present invention.

[0187] As described above, when a base station wireless communication terminal receives a trigger-based PPDU, it can determine whether it has received a valid PPDU, regardless of the frequency band in which the trigger-based PPDU was transmitted. Specifically, when the base station wireless communication terminal receives a PPDU through a frequency band that does not overlap with the main channel and does not receive trigger-based PPDUs, it can determine that it has received an invalid PPDU. In this case, the base station wireless communication terminal can determine whether to update the NAV based on the characteristics of the trigger-based PPDU.

[0188] At this time, when the base station wireless communication terminal receives a trigger-based PPDU through a frequency band overlapping with the main channel, the base station wireless communication terminal can update the NAV based on the trigger-based PPDU.

[0189] Specifically, when the base station wireless communication terminal does not receive a trigger-based PPDU triggered by the base station wireless communication terminal through a frequency band overlapping with the main channel, the base station wireless communication terminal can update the NAV based on the trigger-based PPDU.

[0190] In addition, when the base station wireless communication terminal receives a trigger-based PPDU as an inter-BSS PPDU through a frequency band overlapping with the main channel, the base station wireless communication terminal can update the NAV based on the trigger-based PPDU, regardless of the channel through which it transmits the trigger-based PPDU.

[0191] exist Figure 25 In embodiment (a), the first AP AP1 receives a trigger-based PPDU not triggered by the first AP AP1 via the main channel P20. Because the first AP AP1 receives trigger-based PPDUs, it determines whether a valid PPDU has been received. When it determines that the first AP AP1 has received a valid PPDU, the first AP AP1 issues the PHY-RXSTART.indication primitive. Because the first AP AP1 receives trigger-based PPDUs not triggered by the first AP AP1 via the main channel P20, it updates the NAV based on the trigger-based PPDU. Figure 25 In embodiment (b), the first AP AP1 receives a trigger-based PPDU (PPDU) not triggered by the first AP AP1 via a secondary channel S20 other than the primary channel P20. Because the first AP AP1 receives a trigger-based PPDU, it determines whether a valid PPDU has been received. When the first AP AP1 determines that a valid PPDU has been received, it issues the PHY-RXSTART.indication primitive. Because the first AP AP1 has not received a trigger-based PPDU triggered by the first AP AP1 via the secondary channel S20 other than the primary channel P20, it does not update the NAV based on the trigger-based PPDU.

[0192] When the base station wireless communication terminal uses regular NAV and intra-BSS NAV, the base station wireless communication terminal can selectively update the regular NAV and intra-BSS NAV based on whether the triggered PPDU is an intra-BSS PPDU or an inter-BSS PPDU.

[0193] Specifically, when a base station wireless communication terminal receives a trigger-based PPDU (Programmable Component Distributed Duty) that is not triggered by the base station wireless communication terminal itself through a frequency band overlapping with the main channel, the base station wireless communication terminal can update the regular NAV (Network Addressable Value) based on the trigger-based PPDU. Additionally, when a base station wireless communication terminal receives a trigger-based PPDU that is a BSS (Broadband Service Component Distributed Duty) through a frequency band overlapping with the main channel, the base station wireless communication terminal can update the regular NAV based on the trigger-based PPDU, regardless of the channel through which it transmitted the trigger-based PPDU.

[0194] exist Figure 26 In embodiment (a), the first AP AP1 receives a trigger-based PPDU not triggered by the first AP AP1 via the main channel P20. At this time, the trigger-based PPDU is an inter-BSS PPDU. Because the first AP AP1 receives the trigger-based PPDU, it determines whether a valid PPDU has been received. When it is determined that the first AP AP1 has received a valid PPDU, the first AP AP1 issues the PHY-RXSTART.indication primitive. Because the first AP AP1 receives the trigger-based PPDU not triggered by the first AP AP1 via the main channel P20, the first AP AP1 updates the regular NAV based on the trigger-based PPDU. Figure 26 In embodiment (b), the first AP AP1 receives a trigger-based PPDU not triggered by the first AP AP1 via the secondary channel S20 (other than the primary channel P20). In this case, the trigger-based PPDU is an inter-BSS PPDU. Because the first AP AP1 receives the trigger-based PPDU, it determines whether a valid PPDU has been received. When the first AP AP1 determines that a valid PPDU has been received, it issues the PHY-RXSTART.indication primitive. Because the first AP AP1 receives the trigger-based PPDU not triggered by the first AP AP1 via the secondary channel S20 (other than the primary channel P20), it does not update the regular NAV based on the trigger-based PPDU.

[0195] Figure 27 This illustrates an operation according to another embodiment of the invention, whereby the NAV is updated based on whether the triggered PPDU was triggered by the wireless communication terminal after the wireless communication terminal receives the PPDU and issues the PHY-RXSTART.indication.

[0196] For reference Figures 25 to 26When a base station wireless communication terminal receives a trigger-based PPDU, it can determine whether it has received a valid PPDU, regardless of the frequency band through which the PPDU was transmitted. In this case, if the base station wireless communication terminal receives a trigger-based PPDU that was not triggered by it, it can update the NAV based on the trigger-based PPDU, regardless of the frequency band through which the PPDU was transmitted. Furthermore, when the base station wireless communication terminal receives a trigger-based PPDU that was triggered by it, it can update the NAV only if the trigger-based PPDU was transmitted via a frequency overlapping with the main channel. Additionally, when the base station wireless communication terminal uses both a regular NAV and an intra-BSS NAV, it can selectively update the regular NAV and intra-BSS NAV based on whether the trigger-based PPDU is an intra-BSS PPDU or an inter-BSS PPDU.

[0197] exist Figure 27 In this embodiment, the AP does not receive AP-triggered PPDUs via the secondary channel S20. Because the AP receives trigger-based PPDUs, it determines whether a valid PPDU has been received. When the AP determines that a valid PPDU has been received, it issues the PHY-RXSTART.indication primitive. Because the AP receives trigger-based PPDUs that are not AP-triggered, it updates the NAV based on the trigger-based PPDU. When the AP uses both the regular NAV and the NAV within the BSS, it updates the regular NAV based on the trigger-based PPDU.

[0198] Figure 28 This illustrates an operation according to another embodiment of the invention, whereby the NAV is updated based on whether the triggered PPDU is a PPDU within the BSS after the wireless communication terminal receives the PPDU and issues the PHY-RXEND.indication.

[0199] For reference Figures 25-26When a base station wireless communication terminal receives a trigger-based PPDU, it can determine whether it has received a valid PPDU, regardless of the frequency band in which the trigger-based PPDU was transmitted. In this case, when the base station wireless communication terminal receives a trigger-based PPDU that is an intra-BSS PPDU and does not trigger a trigger-based PPDU, it can update the NAV based on the trigger-based PPDU, regardless of the frequency band in which the trigger-based PPDU was transmitted. Furthermore, when the base station wireless communication terminal receives a trigger-based PPDU that is an inter-BSS PPDU, it can update the NAV only if the trigger-based PPDU is transmitted via a frequency overlapping with the main channel.

[0200] exist Figure 28 In embodiment (a), the AP receives a trigger-based PPDU via secondary channel S20, which is an intra-BSS PPDU. Because the AP receives a trigger-based PPDU as an intra-BSS PPDU, the AP determines whether a valid PPDU has been received. When the AP determines that a valid PPDU has been received, the AP issues the PHY-RXSTART.indication primitive. Because the AP receives a trigger-based PPDU as an intra-BSS PPDU and not triggered by the AP via the secondary channel, the AP updates the NAV based on the trigger-based PPDU. When the AP uses both a regular NAV and an intra-BSS NAV, the AP updates the regular NAV based on the trigger-based PPDU. Figure 28 In embodiment (b), the AP receives a trigger-based PPDU via the secondary channel S20, which is an inter-BSS PPDU. Because the AP receives a trigger-based PPDU as an intra-BSS PPDU, the AP determines whether a valid PPDU has been received. When the AP determines that a valid PPDU has been received, the AP issues the PHY-RXSTART.indication primitive. Because the AP receives a trigger-based PPDU as an inter-BSS PPDU via the secondary channel S20, the AP does not update the NAV based on the trigger-based PPDU.

[0201] Figures 20 to 28 The diagram illustrates the operation of a base station wireless communication terminal in an 80MHz bandwidth. However, embodiments of the invention are not limited to this and can be applied to base station wireless communication terminals operating in bandwidths less than 80MHz (e.g., 20MHz or 40MHz) and bandwidths greater than 80MHz (e.g., 160MHz, 80+80MHz). Additionally, for updating... Figures 20 to 28 The conditions of NAV can be used with the reference for updating. Figures 6 to 19 The conditions described for NAV are applied together.

[0202] Figure 29 The operation of a wireless communication terminal according to an embodiment of the present invention is illustrated.

[0203] The wireless communication terminal receives a PPDU (S2901). The wireless communication terminal can determine whether the received PPDU is valid. At this time, the wireless communication terminal can determine whether the received PPDU is valid based on the signaling field of the received PPDU. When the received PPDU is valid, the wireless communication terminal can issue a received PPDU start indication. In this case, the start indication can be the PHY-RXSTART.indication primitive.

[0204] Furthermore, the wireless communication terminal can determine the validity of a received PPDU based on whether the channel through which it transmits the received PPDU is the main channel. When the wireless communication terminal is a base station wireless communication terminal, it can determine the validity of the received PPDU based on whether it is a triggered PPDU. Specifically, the base station wireless communication terminal can determine whether a PPDU is a valid PPDU based on whether it is a triggered PPDU. In a particular embodiment, when the PPDU received by the base station wireless communication terminal is not a triggered PPDU and is transmitted through a frequency band that does not overlap with the main channel of the BSS operated by the base station wireless communication terminal, the base station wireless communication terminal can determine that the received PPDU is an invalid PPDU. For example, when the PPDU received by the base station wireless communication terminal is not a triggered PPDU and is transmitted through a frequency band that does not overlap with the main channel of the BSS operated by the base station wireless communication terminal, the base station wireless communication terminal may not issue a PPDU reception start indicator. When the PPDU received by the base station wireless communication terminal is a triggered PPDU, even if the PPDU is transmitted through a frequency band that does not overlap with the main channel of the BSS operated by the base station wireless communication terminal, the base station wireless communication terminal can generate an indicator indicating the start of PPDU reception based on the signaling field of the corresponding PPDU.

[0205] According to the reference Figures 20 to 28 In the described embodiment, the base station wireless communication terminal can determine whether it is a valid PPDU.

[0206] The wireless communication terminal performs MAC layer operations based on the received PPDU (S2903). Specifically, the wireless communication terminal can set the NAV based on the PPDU. In a particular embodiment, the wireless communication terminal can set the NAV based on duration information indicated by the signaling field of the PPDU. For example, the wireless communication terminal can set the NAV based on the TXOP_DURATION field of the signaling field of the PPDU. Furthermore, the wireless communication terminal can set the NAV based on the frames included in the PPDU. For example, the wireless communication terminal can set the NAV based on the duration field of the frames included in the PPDU.

[0207] The wireless communication terminal can obtain a trigger frame from the received PPDU and update the NAV based on the trigger frame. In this case, the trigger frame can be a BSS intraframe. That is, the wireless communication terminal can receive the PPDU from the base station wireless communication terminal associated with it. Furthermore, the trigger frame can trigger an immediate response as described above. Additionally, the wireless communication terminal can send a trigger-based PPDU to the base station wireless communication terminal based on the trigger frame, regardless of the NAV value set by the BSS intraframe. Moreover, regardless of the receiver address of the communication terminal, the wireless communication terminal can set the NAV based on the trigger frame. Furthermore, regardless of whether the trigger frame triggers a transmission by the wireless communication terminal, the wireless communication terminal can set the NAV based on the trigger frame.

[0208] In another specific embodiment, the trigger frame may indicate whether the wireless communication terminal needs to perform a CS (Continuous Response) triggered by the trigger frame before sending a trigger-based PPDU (Programmable Component Distributed Duty). Specifically, the trigger frame may include the aforementioned CS requirement field. When the wireless communication terminal, triggered by the trigger frame, indicates that a CS needs to be performed before sending a trigger-based PPDU, the wireless communication terminal may update the NAV (Network Access Vault) based on the trigger frame. In a specific embodiment, when the wireless communication terminal senses that the channel used for sending the trigger-based PPDU is busy via its CS, the wireless communication terminal may update the NAV based on the trigger frame. Furthermore, the wireless communication terminal may update the NAV based on the time required for the CS and the trigger frame. Specifically, the wireless communication terminal may set the NAV based on a time excluding the time spent on the CS from the duration indicated by the duration information. In this case, the duration information may be obtained based on the trigger frame or a PPDU including the trigger frame.

[0209] Wireless communication terminals can be based on references Figures 6 to 18 The described embodiments are used to set up NAV.

[0210] Additionally, the trigger frame may include the aforementioned padding fields. In this case, it can be referenced... Figure 19 The described embodiment is used to set the length of the fill field.

[0211] 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.

[0212] 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.

[0213] 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 associated with a base station, the wireless communication terminal comprising: transceiver; and processor, The processor is configured to: receive Physical Layer Protocol Data Units (PPDUs) from the base station using the transceiver, obtain a trigger frame from the PPDU, and update the Network Allocation Vector (NAV) within the BSS based on the trigger frame, regardless of whether the trigger frame triggers transmission by the wireless communication terminal or the receiver address of the trigger frame. The trigger frame uses the associated ID (AID) field of the trigger frame to trigger the transmission of at least one wireless communication terminal, wherein the AID field indicates the LSB (least significant bit) 12 of the at least one wireless communication terminal. The trigger frame includes a CS request field, which indicates whether carrier sensing is required to send a response frame in response to the trigger frame. The NAV within the BSS is the NAV updated by the BSS intra-frame.

2. An operation method for a wireless communication terminal associated with a base station, the method comprising: Receive physical layer protocol data unit (PPDU) from the base station; Obtain the trigger frame from the PPDU; as well as The network allocation vector (NAV) within the BSS is updated based on the trigger frame, regardless of whether the trigger frame triggers the transmission of the wireless communication terminal or the receiver address of the trigger frame. The trigger frame uses the associated ID (AID) field of the trigger frame to trigger the transmission of at least one wireless communication terminal, wherein the AID field indicates the LSB (least significant bit) 12 of the at least one wireless communication terminal. The trigger frame includes a CS request field, which indicates whether carrier sensing is required to send a response frame in response to the trigger frame. The NAV within the BSS is the NAV updated by the BSS intra-frame.

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