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

Abstract

The present invention relates to a wireless communication method using a network allocation vector and a wireless communication terminal thereof. A wireless communication terminal for wireless communication is provided. The wireless communication terminal includes a transmission / reception unit and a processor. The processor receives a trigger frame by using the transmission / reception unit, and updates a network allocation vector based on the trigger frame. Wherein, the trigger frame triggers transmission of at least one wireless communication terminal.

Description

[0001] This application is a divisional application of the patent application No. 201780064553.5 (PCT / KR2017 / 011617) with the international filing date of 2017.10.19, the title of invention of "Wireless communication method using network allocation vector and wireless communication terminal using the same", filed in the Korean Intellectual Property Office on April 18, 2019. TECHNICAL FIELD

[0002] The present application relates to a wireless communication method and a wireless communication terminal using an enhanced network allocation vector. BACKGROUND

[0003] In recent years, as the supply of mobile devices expands, wireless communication technology that can provide fast wireless Internet services to mobile devices has been significantly noticed by the public. The wireless communication technology allows mobile devices including smart phones, smart pads, laptop computers, portable multimedia players, embedded devices, etc. to access the Internet in a wireless manner in a home or a company or a specific service providing area.

[0004] One of the most famous wireless communication technologies is wireless LAN technology. Since the initial wireless LAN technology using a frequency of 2.4 GHz to support, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 has commercialized or developed various technology standards. First, IEEE 802.11b supports a communication speed of a maximum of 11 Mbps when using a frequency of a 2.4 GHz band. IEEE 802.11a, which was commercialized after IEEE 802.11b, uses a frequency of a 5 GHz band, not a 2.4 GHz band, to reduce the effects of interference compared to a frequency of a 2.4 GHz band that is significantly congested, and to improve a communication speed up to a maximum of 54 Mbps by using an Orthogonal Frequency Division Multiplexing (OFDM) technology. However, IEEE 802.11a has a disadvantage in that a communication distance is shorter than IEEE 802.11b. In addition, IEEE 802.11g similarly to IEEE 802.11b uses a frequency of a 2.4 GHz band to achieve a communication speed of a maximum of 54 Mbps and satisfies backward compatibility to be significantly noticed by the public, and further, is superior to IEEE 802.11a in terms of a communication distance.

[0005] Further, as a technical standard established in order to overcome the limitations of the communication speed pointed out as a weak point in the wireless LAN, IEEE 802.11n has been provided. IEEE 802.11n aims to improve the speed and reliability of the network and to extend the working distance of the wireless network. In more detail, IEEE 802.11n supports high throughput (HT) of which the data processing speed is maximum 540 Mbps or more, and further, a multiple input multiple output (MIMO) technology using multiple antennas on both sides of the transmission unit and the reception unit in order to minimize transmission errors and optimize data speed. Further, the standard can use an encoding scheme that transmits multiple copies overlapping each other in order to improve data reliability.

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

[0007] Meanwhile, in recent years, as the next generation wireless communication technology standard after 802.11ac and 802.11ad, discussions are continuously ongoing for providing high-efficiency and high-performance wireless communication technology in a high-density environment. That is, in the next generation wireless communication technology environment, there is a need to provide communication with high frequency efficiency indoors / outdoors in the presence of high-density terminals and base station terminals, and various technologies for implementing the same are required.

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

[0009] TECHNICAL PROBLEM

[0010] An object of embodiments of the present application is to provide a wireless communication terminal using a network allocation vector.

[0011] TECHNICAL SOLUTION

[0012] A wireless communication terminal associated with a base station wireless communication terminal according to an embodiment of the present application includes a transceiver; and a processor. At this time, the processor is configured to receive a physical layer protocol data unit (PPDU) from the base station wireless communication terminal using the transceiver, obtain a trigger frame from the PPDU, and update a network allocation vector (NAV) frame based on the trigger. The trigger frame can trigger transmission of at least one wireless communication terminal.

[0013] The processor can be configured to transmit a trigger-based PPDU to the base station wireless communication terminal based on the trigger frame regardless of a value of a NAV set based on a frame transmitted from a basic service network operating based on the base station wireless communication.

[0014] The processor can be configured to update the NAV based on the trigger frame regardless of a 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 transmission of the wireless communication terminal.

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

[0017] When it is sensed through the channel sensing that a channel for transmitting the trigger-based PPDU is busy, 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 channel sensing and a time required for the trigger frame.

[0019] A base station wireless communication terminal communicating with a wireless communication terminal according to an embodiment of the present application includes a transceiver; and a processor. The processor is configured to receive a physical layer data unit (PPDU) using the transceiver, and determine whether the PPDU is a valid PPDU based on whether the PPDU is a trigger-based PPDU triggered by the base station wireless communication terminal.

[0020] When the PPDU is not a trigger-based PPDU triggered by the base station wireless communication terminal and the PPDU is transmitted through a frequency band not overlapping a primary channel of a basic service set (BSS) not operating with the base station wireless communication terminal, the processor can be configured to determine that the PPDU is an invalid PPDU.

[0021] When the PPDU is not a trigger-based PPDU triggered by the base station wireless communication terminal and the PPDU is transmitted through a frequency band not overlapping a primary channel of a BSS not operating with the base station wireless communication terminal, the processor can be configured not to emit an indicator indicating the start of PPDU reception.

[0022] When the PPDU is a trigger-based PPDU triggered by the base station wireless communication terminal, even when the PPDU is transmitted through a frequency band overlapping a primary channel of a BSS not operating with the base station wireless communication terminal, the processor can be configured to emit an indicator indicating the start of PPDU reception based on a signaling field of the PPDU.

[0023] An operation method of a wireless communication terminal associated with a base station wireless communication terminal according to an embodiment of the present application includes receiving a physical layer protocol data unit (PPDU) from the base station wireless communication terminal, acquiring 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 can further include transmitting a trigger-based PPDU to the base station wireless communication terminal based on the trigger frame regardless of a value of the NAV set based on a frame transmitted from a basic service network operating with the base station wireless communication terminal.

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

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

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

[0028] The updating of the NAV can include updating the NAV based on the trigger frame when a channel for transmitting the trigger-based PPDU is sensed as busy through channel sensing.

[0029] The updating of the NAV can include updating the NAV based on channel sensing and a time required by the trigger frame.

[0030] Advantageous effects

[0031] Embodiments of the present invention provide a wireless communication method using a network allocation vector and a wireless communication terminal using the same. BRIEF DESCRIPTION OF DRAWINGS

[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 a configuration of a station according to an embodiment of the present invention is shown.

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

[0036] Figure 5 A procedure in which a station sets an access point and a link according to an embodiment of the present invention is shown.

[0037] Figure 6 A wireless communication terminal according to an embodiment of the present invention sets a NAV according to an immediate response request is shown.

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

[0039] Figure 8 A case in which a wireless communication terminal receiving a trigger frame fails to transmit a trigger-based PPDU based on a CS result according to an embodiment of the present invention is shown.

[0040] Figure 9 An operation in which a wireless communication terminal updates a NAV according to another embodiment of the present invention is shown.

[0041] Figure 10 An operation in which a wireless communication terminal updates a NAV according to another embodiment of the present invention is shown.

[0042] Figures 11-12 A method in which a wireless communication terminal determines whether an immediate response to a trigger frame is required based on a CS requirement field according to an embodiment of the present invention is shown.

[0043] Figures 13-14 A time point for setting a NAV of a wireless communication terminal according to an embodiment of the present invention is shown.

[0044] Figures 15-16 A time point in which a wireless communication terminal sets a NAV when the wireless communication terminal updates the NAV based on a result of a CS required for transmitting a trigger-based PPDU according to an embodiment of the present invention is shown.

[0045] Figures 17-18 A point in time when a wireless communication terminal sets a NAV is shown when the wireless communication terminal updates the NAV based on a result of a CS required for transmitting a trigger-based PPDU according to another embodiment of the present application.

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

[0047] Figures 20-23 An operation in which a wireless communication terminal receives a PPDU and issues a PHY-RXSTART.indication according to an embodiment of the present application is shown.

[0048] Figure 24 An operation in which a wireless communication terminal receives a PPDU and issues a PHY-RXSTART.indication according to another embodiment is shown.

[0049] Figure 25 And Figure 26 An operation in which a wireless communication terminal receives a PPDU and issues a PHY-RXSTART.indication and updates a NAV according to another embodiment of the present application is shown.

[0050] Figure 27 An operation in which a wireless communication terminal updates a NAV according to whether a trigger-based PPDU is triggered by the wireless communication terminal after the wireless communication terminal receives the PPDU and issues a PHY-RXSTART.indication according to another embodiment of the present application is shown.

[0051] Figure 28 An operation in which a wireless communication terminal updates a NAV according to whether a trigger-based PPDU is an intra-BSS PPDU after the wireless communication terminal receives the PPDU and issues a PHY-RXSTART.indication according to another embodiment of the present application is shown.

[0052] Figure 29 An operation of a wireless communication terminal according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0053] Preferred embodiments of the present application will be described in greater detail below with reference to the accompanying drawings. However, the present application can be embodied in different forms without being limited to the embodiments set forth herein. Portions that are not related to the description have been omitted from the drawings so as to clearly describe the present application, and like reference numerals refer to like elements throughout.

[0054] Also, when it is described that an object includes (or comprises or has) some elements, it should be understood that, if there is no specific limitation, it can include (or comprise or have) only those elements, or it can include (or comprise or have) other elements as well as those elements.

[0055] This application claims priority to and the benefit of Korean Patent Application Nos. 10-2016-0136095 (2016.10.19), Nos. 10-2016-0147190 (2016.11.06), Nos. 10-2017-0029524 (2017.03.08), and Nos. 10-2017-0057638 (2017.05.08) filed with the Korean Intellectual Property Office, and the embodiments and items mentioned in the corresponding applications are included in the detailed description of the present application.

[0056] Figure 1 FIG. 1 is a diagram illustrating a wireless communication system according to an embodiment of the present application. For the convenience of description, the embodiments of the present application are described through a wireless LAN system. The wireless LAN system includes one or more basic service sets (BSSs) and the BSS denotes a set of devices successfully synchronized with each other to communicate with each other. In general, the BSSs can be classified into an infrastructure BSS and an independent BSS (IBSS) and Figure 1 FIG. 1 illustrates an infrastructure BSS among them.

[0057] As Figure 1 As illustrated in FIG. 1, the infrastructure BSSs (BSS1 and BSS2) include one or more stations STA1, STA2, STA3, STA4, and STA5, an access point PCP / AP-1 and PCP / AP-2 as a station providing a distribution service, and a distribution system (DS) connecting the plurality of access points PCP / AP-1 and PCP / AP-2.

[0058] A station (STA) is a predetermined device including a medium access control (MAC) following the procedure of the IEEE 802.11 standard and a physical layer interface for a wireless medium, and in a broad sense, includes a non-access point (non-AP) station and an access point (AP). Also, in the present specification, the term "terminal" can be used to refer to the concept of a wireless LAN communication device including, such as a non-AP STA or an AP or both terms. The station for wireless communication includes a processor and a transceiver, and according to the embodiments, can further include a user interface unit and a display unit. The processor can generate a frame to be transmitted through a wireless network or process a frame received through a wireless network, and in addition, perform various processes for controlling the station. Also, the transceiver is functionally connected with the processor and transmits and receives frames through a wireless network for the station.

[0059] An access point (AP) is an entity that provides access, via a wireless medium, to a distribution system (DS) for stations associated with it. In an infrastructure BSS, communication between non-AP stations is performed via the AP in principle, but when a direct link is configured, direct communication can be achieved even between non-AP stations. Meanwhile, in the present invention, the AP is used as a concept including a personal BSS coordination point (PCP) and can include a concept broadly including a centralized controller, a base station (BS), a node B, a base transceiver system (BTS), and a site controller.

[0060] A plurality of infrastructure BSSs can be connected to each other through a distribution system (DS). In this case, the plurality of BSSs connected through the distribution system is referred to as an extended service set (ESS).

[0061] Figure 2 FIG. 1 illustrates an independent BSS as a wireless communication system according to another embodiment of the present invention. For convenience of description, another embodiment of the present invention is described through a wireless LAN system. In the following description, the same or similar components as those of the embodiment of FIG. 1 are designated by the same reference numerals, and a repeated description thereof will be omitted. Figure 2 In the embodiment of FIG. 1, a description of components identical or corresponding to those of the embodiment of FIG. 1 will be omitted. Figure 1 In the embodiment of FIG. 1, a description of components identical or corresponding to those of the embodiment of FIG. 1 will be omitted.

[0062] Because the BSS 3 illustrated in FIG. 2 is an independent BSS and does not include an AP, all of the stations STA6 and STA7 are not connected to the AP. The independent BSS is not permitted to access a distribution system and forms a self-contained network. In the independent BSS, the respective stations STA6 and STA7 can be directly connected to each other. Figure 2

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

[0064] As illustrated in FIG. 4, the station 100 according to an embodiment of the present invention can include a processor 110, a transceiver 120, a user interface unit 140, a display unit 150, and a memory 160. Figure 3

[0065] ​​First, the transceiver 120 transmits and receives a wireless signal such as a wireless LAN physical layer frame and can be embedded in the station 100 or provided as an external. According to the embodiment, the transceiver 120 can include at least one transmission and reception module using different frequency bands. For example, the transceiver 120 can include transmission and reception modules having different frequency bands such as 2.4 GHz, 5 GHz, and 60 GHz. According to the embodiment, the station 100 can include a transmission and reception module using a frequency band of 6 GHz or more and a transmission and reception module using a frequency band of 6 GHz or less. The corresponding transmission and reception modules can perform wireless communication with an AP or an external station according to a wireless LAN standard of a frequency band supported by the corresponding transmission and reception module. The transceiver 120 can operate only one transmission and reception module at a time according to the performance and requirements of the station 100 or simultaneously operate a plurality of transmission and reception modules together. When the station 100 includes a plurality of transmission and reception modules, each transmission and reception module can be implemented by an independent element or a plurality of modules can be integrated into one chip.

[0066] Next, the user interface unit 140 includes various types of input / output devices provided in the station 100. That is, the user interface unit 140 can receive a 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 perform output based on a command of the processor 110 by using various output devices.

[0067] Next, the display unit 150 outputs an image on a display screen. The display unit 150 can output various display objects such as content or a user interface executed by the processor 110 based on a control command of the processor 110 or the like. In addition, the memory 160 stores a control program used in the station 100 and various result obtained data. The control program can include an access program required for the station 100 to access an AP or an external station.

[0068] The processor 110 of the present application can execute various commands or programs and process data in the station 100. In addition, the processor 110 can control respective units of the station 100 and control data transmission / reception between the units. According to an embodiment of the present application, the processor 110 can execute a program for accessing an AP stored in the memory 160 and receive a communication configuration message transmitted by the AP. In addition, the processor 110 can read information about a priority condition of the station 100 included in the communication configuration message and request access to the AP based on the information about the priority condition of the station 100. The processor 110 of the present application can represent a main control unit of the station 100 and according to the embodiment, the processor 110 can represent a control unit for individually controlling a certain component (e.g., the transceiver 120, etc.) of the station 100. The processor 110 can be a modulator and / or demodulator that modulates a wireless signal transmitted to the transceiver 120 and demodulates a wireless signal received from the transceiver 120. The processor 110 controls various operations of wireless signal transmission / reception of the station 100 according to an embodiment of the present application. Detailed embodiments thereof will be described below.

[0069] Figure 3 The station 100 illustrated in FIG. 1 is a block diagram according to an embodiment of the present application in which individual blocks are illustrated as logically distinguished elements of the device. Accordingly, elements of the device can be mounted in a single chip or a plurality of chips depending on the design of the device. For example, the processor 110 and the transceiver 120 can be integrated into a single chip or implemented as separate chips to be implemented. In addition, in an embodiment of the present application, some components of the station 100, such as the user interface unit 140 and the display unit 150, can be optionally provided in the station 100.

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

[0071] As Figure 4 illustrated in FIG. 2, the AP 200 according to an embodiment of the present application can include a processor 210, a transceiver 220, and a memory 260. In Figure 4 , among the components of the AP 200, a repeated description of parts identical or corresponding to the components of the station 100 of Figure 2 will be omitted.

[0072] Referring to Figure 4 , the AP 200 according to the present application includes the transceiver 220 for operating a BSS in at least one frequency band. As Figure 3The transceiver 220 of the AP 200 described in the embodiments can also include a plurality of transmission and reception modules using different frequency bands. That is, the AP 200 according to the embodiments of the present application can include two or more transmission and reception modules among different frequency bands (for example, 2.4 GHz, 5 GHz, and 60 GHz) together. Preferably, the AP 200 can include a transmission and reception module using a 6 GHz or higher frequency band and a transmission and reception module using a 6 GHz or lower frequency band. The corresponding transmission and reception modules can perform wireless communication with stations according to the wireless LAN standard of the frequency band supported by the corresponding transmission and reception module. The transceiver 220 can operate only one transmission and reception module at a time according to the performance and requirements of the AP 200 or operate a plurality of transmission and reception modules together simultaneously.

[0073] Next, the memory 260 stores a control program used in the AP 200 and various result-derived data. The control program can include an access program for managing access of stations. In addition, the processor 210 can control the corresponding units of the AP 200 and control data transmission / reception between the units. According to the embodiments of the present application, the processor 210 can execute a program for accessing stations stored in the memory 260 and transmit a communication configuration message for one or more stations. In this case, the communication configuration message can include information on an access priority condition of the corresponding station. In addition, the processor 210 performs access configuration according to an access request of a station. The processor 210 can be a modulator and / or demodulator that modulates a wireless signal transmitted to the transceiver 220 and demodulates a wireless signal received from the transceiver 220. The processor 210 controls various operations such as radio signal transmission / reception of the AP 200 according to the first embodiment of the present application. Detailed embodiments thereof will be described below.

[0074] Figure 5 is a diagram schematically illustrating a procedure in which a STA sets a link with an AP.

[0075] Reference Figure 5 A link between the STA 100 and the AP 200 is generally set through three steps of scanning, authentication, and association. First, the scanning step is a step in which the STA 100 obtains access information of a BSS operated by the AP 200. Methods for performing scanning include a passive scanning method in which the AP 200 obtains information by using a beacon message (S101) periodically transmitted and an active scanning method in which the STA 100 transmits a probe request to the AP (S103) and obtains access information by receiving a probe response from the AP (S105).

[0076] The STA 100 that successfully receives the wireless access information in the scanning step performs an authentication step by transmitting an authentication request (S107a) and receiving an authentication response (S107b) from the AP 200. After the authentication step is performed, the STA 100 performs an association step by transmitting an association request (S109a) and receiving an association response (S109b) from the AP 200.

[0077] Meanwhile, an 802.1X-based authentication step (S111) and an IP address obtaining step (S113) through DHCP can be additionally performed. In Figure 5 In the authentication server 300, the authentication server 300 is a server that processes 802.1X-based authentication of the STA 100 and can exist in physical association with the AP 200 or exist as a separate server.

[0078] In a specific embodiment, the AP 200 can be a wireless communication terminal that allocates communication medium resources and performs scheduling in a separate network (such as an ad hoc network) that is not connected to an external distribution service. Further, the AP 200 can be at least one of a base station, an eNB, and a transmission point TP. The TP 200 can also be referred to as a base station communication terminal.

[0079] The base station wireless communication terminal can be a wireless communication terminal that allocates and schedules medium resources for communication with a plurality of wireless communication terminals. Specifically, the base station wireless communication terminal can function as a cell coordinator. In a specific embodiment, the base station wireless communication terminal can be a wireless communication terminal that allocates and schedules communication medium resources in a separate network (such as an ad hoc network) that is not connected to an external distribution service.

[0080] The wireless communication terminal can use a network allocation vector (NAV), which is an indicator indicating a time interval in which transmission is not allowed, to avoid a transmission conflict with other wireless communication terminals. When the NAV is not 0, the wireless communication terminal can determine that the corresponding wireless medium is busy. In addition, when the NAV is 0, the wireless communication terminal can determine that the corresponding wireless medium is idle. In this way, which is referred to as virtual channel sensing (CS), the wireless communication terminal determines whether the corresponding wireless medium can be idle according to the value of the NAV. Specifically, the NAV can be maintained regardless of the clear channel assessment (CCA) result of the wireless communication terminal. For example, when the NAV of the wireless communication terminal is set, transmission through the corresponding wireless medium of the wireless communication terminal can not be allowed regardless of the CCA result of the corresponding wireless medium. In addition, when the corresponding wireless medium is idle in virtual CS and is busy based on the CCA result, transmission through the corresponding wireless medium of the wireless communication terminal can not be allowed.

[0081] When the wireless communication terminal obtains a valid frame from a physical service data unit (PSDU), the wireless communication terminal can update the NAV according to valid duration information indicated by the PSDU. Specifically, when the wireless communication terminal is requested in an immediate response to a physical layer protocol data unit (PPDU) carrying a corresponding frame, the wireless communication terminal can not update the NAV. At this time, the immediate response can indicate a response transmitted within a predetermined time from when the PPDU is received in a TXOP in which the PPDU is transmitted. The predetermined time can be a short interframe space (SIFS).

[0082] In addition, when the wireless communication terminal receives a DMG CTS frame and a receiver address of the corresponding CTS frame indicates the wireless communication terminal, the wireless communication terminal can not update the NAV. Except for the above two cases, when a value of a DURATION field of a frame received by the wireless communication terminal is greater than a value of a current NAV, the wireless communication terminal can update the NAV according to 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. In addition, when the wireless communication terminal receives a power save (PS)-Poll frame, the wireless communication terminal can set the NAV using a sum of a time required for ACK frame transmission and SIFS. At this time, the wireless communication terminal can use time in units of microseconds. The wireless communication terminal can determine the time required for ACK frame transmission according to a data rate selection rule. In this case, when a decimal point value of the sum of the time required for ACK frame transmission and SIFS in units of microseconds is not 0, the wireless communication terminal can set the NAV by rounding up the sum of the time required for ACK frame transmission and SIFS to the nearest integer value.

[0084] In certain embodiments, when all of the following conditions are satisfied, the wireless communication terminal can update the NAV according to duration information indicated by TXOP_DURATION, which is a parameter of RXVECTOR.

[0085] - a value of TXOP_DURATION, which is a parameter of RXVECTOR, is specified.

[0086] - the wireless communication terminal does not receive a frame having a duration indicated by a DURATION field in a PPDU having TXOP_DURATION, which is a parameter of RXVECTOR.

[0087] - a value indicated by TXOP_DURATION, which is a parameter of RXVECTOR, is greater than a value of a current NAV.

[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, the RXVECTOR indicates information transmitted from a physical layer to a medium access control (MAC) layer by the wireless communication terminal. In addition, when the wireless communication terminal receives a header of a valid PPDU, the wireless communication terminal can transmit the RXVECTOR from the physical layer to the MAC layer. At this time, the wireless communication terminal can transmit a PPDU reception start indicator to be described in the following embodiments. In addition, 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 often communicate in a dense environment. In particular, the number of cases in which wireless communication terminals communicate in an environment in which a plurality of BSSs overlap is increasing. When a plurality of BSSs overlap, the communication efficiency of the wireless communication terminal can decrease due to interference with other wireless communication terminals. Specifically, when a frequency band is used through a contention process, the wireless communication terminal can not even obtain a transmission opportunity due to interference with other wireless communication terminals. In order to solve this problem, the wireless communication terminal can perform a spatial reuse (SR) operation. Specifically, the SR operation can include an operation of accessing a channel depending on whether a received frame is a frame transmitted from a BSS including the wireless communication terminal or a frame transmitted from another BSS. In a particular embodiment, the operation of accessing a channel can include a NAV setting, resetting, and updating operation. For ease of explanation, a BSS to which the wireless communication terminal belongs is referred to as in-BSS, and a basic service set overlapping the in-BSS is referred to as an overlapping basic service set (OBSS). In addition, a PPDU transmitted from the in-BSS is referred to as an in-BSS PPDU, and a frame transmitted from the OBSS is referred to as an OBSS PPDU or an inter-BSS PPDU. In addition, a frame transmitted in the in-BSS is referred to as an in-BSS frame, and a frame transmitted in the OBSS is referred to as an OBSS frame or an inter-BSS frame.

[0091] In particular, 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. In particular, the wireless communication terminal can separately maintain a NAV for intra-BSS frames and a NAV for inter-BSS frames. At this time, when the wireless communication terminal receives an intra-BSS frame, the wireless communication terminal can set or update the NAV for intra-BSS frames based on the received intra-BSS frame. In addition, when the frame received by the wireless communication terminal can not be determined as an intra-BSS frame or an inter-BSS frame, the wireless communication terminal can update the NAV for inter-BSS frames based on the received frame. In addition, when the wireless communication terminal receives an inter-BSS frame, the wireless communication terminal can set or update the NAV for inter-BSS frames based on the received inter-BSS frame. For ease of explanation, the NAV for intra-BSS frames is referred to as an intra-NAV, and the NAV for inter-BSS frames is referred to as a regular NAV.

[0092] When the wireless communication terminal uses the intra-NAV and the regular NAV, the wireless communication terminal can determine the following in the virtual CS. When both the intra-NAV and the regular NAV are 0, the wireless communication terminal can determine that the corresponding wireless medium is idle in the virtual CS. Also, when at least one of the intra-NAV and the 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, when all of the following conditions are satisfied, the wireless communication terminal can update the intra-BSS NAV according to duration information indicated by a frame included in a PSDU.

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

[0095] - Duration information indicated by the frame received by the wireless communication terminal is greater than a current intra-BSS NAV value.

[0096] - The wireless communication terminal is not forced to transmit an immediate response to a PPDU carrying the frame received by the wireless communication terminal.

[0097] In a particular embodiment, when all of the following conditions are satisfied, the wireless communication terminal can update the regular NAV according to duration information indicated by a frame included in a PSDU.

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

[0099] - Duration information indicated by the frame received by the wireless communication terminal is greater than a current intra-BSS NAV value.

[0100] - The wireless communication terminal is not forced to transmit an immediate response to a PPDU carrying the frame received by the wireless communication terminal.

[0101] In certain embodiments, the wireless communication terminal can update the Intra-BSS NAV with the duration information indicated by TXOP_DURATION (which is a parameter of RXVECTOR) when all of the following conditions are met.

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

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

[0104] - the wireless communication terminal does not receive a frame with a duration indicated by the DURATION field in the PPDU with 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 the current Intra-BSS NAV.

[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 certain embodiments, 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] - the value of TXOP_DURATION (which is a parameter of RXVECTOR) is specified.

[0109] - the wireless communication terminal determines the PPDU carrying TXOP_DURATION (which is a parameter of RXVECTOR) as an Inter-BSS PPDU, or can not determine whether the PPDU carrying TXOP_DURATION (which is a parameter of RXVECTOR) is an Intra-BSS PPDU or an Inter-BSS PPDU.

[0110] - the wireless communication terminal does not receive a frame with a duration indicated by the DURATION field in the PPDU with TXOP_DURATION (which is a parameter of RXVECTOR).

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

[0112] When the PS-Poll frame is transmitted through the HE SU PPDU, the HE Extended Range SU PPDU, or the HE MU PPDU, TXOP_DURATION of the PPDU carrying the PS-Poll frame, which is a parameter of RXVECTOR, can not indicate the duration information.

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

[0114] When the wireless communication terminal resets any one of the intra-BSS NAV and the regular NAV in the case where the value of the other NAV is 0, the wireless communication terminal can initialize the reception state of the physical layer. Specifically, when the wireless communication terminal resets any one of the intra-BSS NAV and the regular NAV in the case where the value of the other NAV is 0, the wireless communication terminal can issue a PHY-CCARESET.request primitive from the MAC layer to the physical layer.

[0115] Figure 6 The wireless communication terminal according to an embodiment of the present application is shown to set the NAV according to the immediate response request.

[0116] The wireless communication terminal can set the NAV according to whether the intended recipient of the frame received by the wireless communication terminal is the wireless communication terminal. Specifically, when the intended recipient of the frame received by the wireless communication terminal is not the wireless communication terminal, the wireless communication terminal can set the NAV according to the received frame. In this case, the wireless communication terminal can determine whether the intended recipient of the received frame is the wireless communication terminal based on whether at least one of the receiver address (RA) field, the user info field, and the AID subfield of the frame indicates the wireless communication terminal.

[0117] In addition, the wireless communication terminal can set the NAV according to whether the frame received by the wireless communication terminal requires an immediate response. Specifically, when the frame received by the wireless communication terminal requires an immediate response, the wireless communication terminal can not set the NAV according to the received frame. Furthermore, when the frame received by the wireless communication terminal does not require an immediate response and other conditions for the NAV setting are satisfied, the wireless communication terminal can set the NAV according to the received frame. The wireless communication terminal can determine whether the frame requires an immediate response according to at least one of the frame type, the subtype, and the ACK policy subfield.

[0118] In 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 field can include a trigger type field indicating a type of the trigger frame. Further, the common information field can include a length field indicating a length of the trigger frame. In addition, the common information field can include a cascade indication field indicating whether a cascade transmission procedure is continued in the trigger frame. In addition, the common information field can include a CS required field indicating whether a CS is required in transmitting a response to the trigger frame. At this time, the response to the trigger frame can be a trigger-based PPDU. Further, the common information field can include a BW field indicating information about a frequency band used for transmitting the response to the trigger frame. In addition, the common information field can include a GI and LTF type field indicating information about a GI and an LTF used for transmitting the response to the trigger frame. In addition, the common information field can further include a MU-MIMO LTF mode field indicating information about a MU-MIMO and an LTF mode used for transmitting the response to the trigger frame. In addition, the common information field can include an HE-LTF symbol number field indicating a number of LTF symbols used for transmitting the response to the trigger frame. Further, the common information field can include an STBC field indicating whether an STBC is used to transmit the response to the trigger frame. In addition, the common information field can include an LDPC additional symbol field indicating whether an LDPC additional symbol is used to transmit the response to the trigger frame. Further, the common information field can include an AP Tx power field indicating a transmission power used for transmitting the trigger frame. In addition, the common information field can include a packet extension field indicating a duration of a packet extension part used for transmitting the response to the trigger frame. In addition, the common information field can include a spatial reuse field indicating a value of an SR field of an HE SIG-A field of a PPDU used for transmitting the response to the trigger frame. In addition, the common information field can include a Doppler field indicating whether a Doppler effect is applied to transmission of the response to the trigger frame. Further, the common information field can include a trigger-related common information subfield determined according to the type of the trigger frame.

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

[0124] Figure 8 A case in which the wireless communication terminal receiving the trigger frame according to an embodiment of the present application fails to transmit the trigger-based PPDU based on the CS result is illustrated.

[0125] As described above, the wireless communication terminal requested for immediate response to the frame does not update the NAV. However, when the CS required 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 info field of the trigger frame performs CS when transmitting the trigger-based PPDU based on the trigger frame. At this time, when the CS result indicates that the channel for transmitting the trigger-based PPDU is busy, the wireless communication terminal can not transmit the trigger-based PPDU. Accordingly, even the wireless communication terminal receiving the request for immediate response to the frame can not transmit the immediate response according to the value of the CS required field of the trigger frame. The wireless communication terminal receiving the request for immediate response does not transmit the immediate response, but the NAV is not set. Accordingly, fairness in channel access between the wireless communication terminals can be violated. In addition, the wireless communication terminal receiving the request for immediate response can interfere with transmission of the trigger-based PPDU of another wireless communication terminal receiving the request for immediate response together.

[0126] In 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 11-12 This will be described.

[0143] Figures 11-12 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 13-18 This will describe the operational time points related to the NAV settings of the wireless communication terminal.

[0147] Figures 13-14 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 NAV value 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 15-16 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 6-18In 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 20-23 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 a PPDU 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 21-23 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 25-28 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 25-26When 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 20-28 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 20-28 The conditions of NAV can be used with the reference for updating. Figures 6-19 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 20-28 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 6-18 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 wireless communication terminal, the wireless communication terminal comprising: transceiver; and processor, The processor is configured to: receive Physical Layer Protocol Data Units (PPDUs) from the base station wireless communication terminal using the transceiver, obtain a trigger frame from the PPDU, and update the Network Allocation Vector (NAV) within the Basic Service Set (BSS) based on the trigger frame, regardless of the receiver address of the trigger frame. The trigger frame uses the associated ID (AID) field of the trigger frame to trigger transmission from at least one wireless communication terminal, wherein the AID field indicates the least significant bit (LSB) of the at least one wireless communication terminal. The NAV within the BSS is the NAV updated by the BSS intra-frame.

2. The wireless communication terminal according to claim 1, wherein, The processor is configured to update the NAV within the BSS based on the trigger frame, regardless of whether the trigger frame triggers transmission from the wireless communication terminal.

3. A method for operating a wireless communication terminal associated with a base station wireless communication terminal, the method comprising: Receive Physical Layer Protocol Data Unit (PPDU) from the base station wireless communication terminal; Obtain the trigger frame from the PPDU; as well as The Network Allocation Vector (NAV) within the Basic Service Set (BSS) is updated based on the trigger frame, regardless of the receiver address of the trigger frame. The trigger frame uses the associated ID (AID) field of the trigger frame to trigger transmission from at least one wireless communication terminal, wherein the AID field indicates the least significant bit (LSB) of the at least one wireless communication terminal. The NAV within the BSS is the NAV updated by the BSS intra-frame.

4. The method according to claim 3, wherein, The update of the NAV within the BSS includes: updating the NAV within the BSS based on the trigger frame, regardless of whether the trigger frame triggers the transmission of the wireless communication terminal.

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