Method and device for channel access in wi-fi communication

Abstract

The present disclosure relates to a method and device for channel access in a wireless local area network (WLAN) communication system. According to an embodiment of the present disclosure, a method performed by a station in a wireless local area network (WLAN) communication system comprises the steps of: receiving a first frame from an access point associated with the station; switching an operating channel from a basic service set (BSS) primary channel to a non-primary channel access (NPCA) primary channel; identifying NPCA channel access delay-related information included in the first frame; and initiating uplink transmission after a time point based on the NPCA channel access delay-related information.

Description

Method and device for channel access in Wi-Fi communication

[0001] The present disclosure relates to Wi-Fi communication between electronic devices, and more specifically, to a method and apparatus for channel access in Wi-Fi communication.

[0002] Recently, due to the development of wireless technology, wired networks used by many people are being replaced by wireless networks. In other words, as wireless technology can solve the mobility limitations of wired networks, many technologies utilizing wireless networks are being actively researched.

[0003] Wireless Local Area Networks (WLANs), also known by the alias Wi-Fi, allow users to access the internet via mobile devices or laptops within a certain distance from an Access Point (AP). The Wi-Fi Alliance defines Wi-Fi as a wireless local area network (WLAN) product based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. Wi-Fi communication primarily uses the 2.4 GHz and 5 GHz wireless bands. In particular, with the popularization of mobile devices, wireless LANs, which possess potential as open wireless networks, are expanding rapidly, and Wi-Fi is being used to provide high-speed data services throughout cities, including in schools, airports, hotels, and offices.

[0004] The Internet is evolving from a human-centered network where humans generate and consume information into an IoT (Internet of Things) network where distributed components, such as objects, exchange and process information. IoE (Internet of Everything) technology, which combines IoT with big data processing technologies through connections with cloud servers, is also emerging. Implementing IoT requires technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology. Recently, technologies such as sensor networks, Machine-to-Machine (M2M) communication, and Machine-Type Communication (MTC) are being researched for connecting objects.

[0005] In an IoT environment, intelligent IT (Internet Technology) services that create new value for human life by collecting and analyzing data generated from connected objects can be provided. Through the convergence and integration of existing IT (Information Technology) with various industries, IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.

[0006] Meanwhile, in wireless communication systems, the channel access method is crucial for ensuring efficient communication among multiple user terminals. Wi-Fi networks based on the IEEE 802.11 standard primarily coordinate channel access through the CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) protocol. This method detects channel conditions prior to transmission to prevent data collisions and allows data transmission only when the channel is free. However, as the number of terminals in the network increases or traffic load grows, channel access delays and the likelihood of collisions increase, which can negatively impact Quality of Service (QoS). To address this, various improvement techniques have been proposed, including scheduling-based approaches, priority-based approaches, and dynamic channel allocation. In particular, efficient channel resource management is essential to meet the requirements of real-time applications. Accordingly, there is a demand for the development of new channel access technologies to maximize channel utilization and minimize transmission delays.

[0007] The present disclosure aims to provide a method and apparatus for channel access during Wi-Fi communication.

[0008] The present disclosure proposes a method for non-primary channel access (NPCA) APs (access points) to share information for NPCA operation in an NPCA primary channel during Wi-Fi communication.

[0009] The present disclosure proposes a method in which an NPCA AP provides information regarding channel access delay for an NPCA primary channel when sharing information for NPCA operation within a basic service set (BSS) during Wi-Fi communication.

[0010] The technical problems to be solved by the present disclosure are not limited to those mentioned above, and other unmentioned technical problems may be considered by those skilled in the art from the various embodiments of the present disclosure described below.

[0011] A method by a station performing Wi-Fi communication according to one embodiment of the present disclosure comprises: receiving a first frame from an access point to which the station is associated; switching the operating channel from a basic service set (BSS) primary channel to a non-primary channel access (NPCA) primary channel; identifying information related to an NPCA channel access delay included in the first frame; and initiating uplink transmission after a time point based on the information related to the NPCA channel access delay.

[0012] A method by an access point performing Wi-Fi communication according to one embodiment of the present disclosure comprises: transmitting a first frame to at least one connected station; and switching an operating channel from a BSS primary channel to an NPCA primary channel; wherein the first frame includes information related to an NPCA channel access delay, and the information related to the NPCA channel access delay initiates uplink transmission to the at least one connected station after a time point based on the information related to the NPCA channel access delay.

[0013] According to one embodiment of the present disclosure, a station performing Wi-Fi communication comprises: a transceiver; and at least one processor connected to the transceiver; wherein the at least one processor is configured to receive a first frame from an access point associated with the station, switch the operating channel from a basic service set (BSS) primary channel to a non-primary channel access (NPCA) primary channel, identify information related to an NPCA channel access delay included in the first frame, and initiate uplink transmission after a time point based on the information related to the NPCA channel access delay.

[0014] According to one embodiment of the present disclosure, an access point performing Wi-Fi communication comprises: a transceiver; and at least one processor connected to the transceiver; wherein the at least one processor is configured to transmit a first frame to at least one connected station and to switch an operating channel from a BSS primary channel to an NPCA primary channel, the first frame includes information related to an NPCA channel access delay, and the information related to the NPCA channel access delay instructs the at least one connected station to initiate uplink transmission after a time point based on the information related to the NPCA channel access delay.

[0015] The various embodiments of the present disclosure described above are merely some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the various embodiments of the present disclosure can be derived and understood by those skilled in the art based on the detailed description to be described below.

[0016] According to one embodiment of the present disclosure, network resource utilization efficiency and service quality can be improved as an NPCA (non-primary channel access) AP (access point) shares information for NPCA operation in an NPCA primary channel.

[0017] The effects obtainable from the various embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by those skilled in the art based on the following detailed description.

[0018] FIG. 1 is a drawing for illustrating an example of a short-range communication connection type between an electronic device and an access point according to one embodiment of the present disclosure.

[0019] FIG. 2 is a diagram illustrating the operation of an access point (AP) and a station (STA) for establishing a wireless LAN connection according to one embodiment of the present disclosure.

[0020] FIG. 3 is a drawing for illustrating an example of a short-range communication connection type of an electronic device according to one embodiment of the present disclosure.

[0021] FIG. 4 is a drawing illustrating an example of a frame structure used in an IEEE 802.11 system according to one embodiment of the present disclosure.

[0022] FIG. 5 is a diagram illustrating an example of a network allocation vector (NAV) setting according to one embodiment of the present disclosure.

[0023] FIG. 6 is a drawing illustrating an example of a TXOP (transmission opportunity) according to one embodiment of the present disclosure.

[0024] FIG. 7 is a drawing illustrating an example of non-primary channel access (NPCA) according to one embodiment of the present disclosure.

[0025] FIG. 8 is a diagram illustrating an example of operation between an NPCA AP and a plurality of NPCA STAs during NPCA operation according to an embodiment of the present disclosure.

[0026] FIG. 9 is a diagram illustrating an example of field or element formats within a frame used by an NPCA AP according to one embodiment of the present disclosure to transmit channel access delay related information to an NPCA STA in a BSS.

[0027] FIG. 10 is a flowchart illustrating the operation of a station according to one embodiment of the present disclosure.

[0028] FIG. 11 is a flowchart illustrating the operation of an access point according to one embodiment of the present disclosure.

[0029] FIG. 12 is a drawing showing an example of a configuration of a station according to one embodiment of the present disclosure.

[0030] FIG. 13 is a drawing showing an example of a configuration of an access point according to one embodiment of the present disclosure.

[0031] The drawings are included as reference examples to aid in understanding the invention and are not limited to specific embodiments of the invention. The specific details depicted in the drawings are intended to supplement the overall technical background and context of the invention and may provide technical information beneficial to the invention even if not directly specified in the claims.

[0032] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0033] In describing the embodiments, technical details that are well known in the technical field to which this disclosure belongs and are not directly related to this disclosure are omitted. This is intended to convey the essence of this disclosure more clearly without obscuring it by omitting unnecessary explanations.

[0034] For the same reason, some components in the attached drawings have been exaggerated, omitted, or schematically depicted. Additionally, the size of each component does not entirely reflect its actual dimensions. Identical or corresponding components in each drawing have been assigned the same reference number.

[0035] The advantages and features of the present disclosure and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. The embodiments of the present disclosure are provided merely to make the present disclosure complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Throughout the specification, like reference numerals refer to like components.

[0036] At this point, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create means to perform the functions described in the flow diagram block(s). Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in computer-available or computer-readable memory can also produce a manufactured item containing means of instruction to perform the function described in the flow diagram block(s).

[0037] Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that execute a computer or other programmable data processing equipment by performing a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer may also provide steps for executing the functions described in the flowchart block(s).

[0038] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For instance, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may be executed in reverse order depending on the corresponding function.

[0039] In this embodiment, the term "part" used refers to a software or hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the "part" performs certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or may be configured to run one or more processors. Accordingly, according to some embodiments, the "part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts." In addition, the components and 'parts' may be implemented to utilize one or more CPUs within the device or secure multimedia card. Furthermore, according to some embodiments, the 'parts' may include one or more processors.

[0040] In the present disclosure, each of the phrases such as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B or C,” “at least one of A, B and C,” and “at least one of A, B, or C” may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. Terms such as “first,” “second,” or “first” or “second” may be used simply to distinguish a corresponding component from another corresponding component and do not limit the components in any other aspect (e.g., importance or order).

[0041] Unless specifically stated otherwise, in the description of an embodiment of the present disclosure, "greater than" may be replaced with "greater than," and "greater than" may be replaced with "greater than." Unless specifically stated otherwise, in the description of an embodiment of the present disclosure, "less than" may be replaced with "less than," and "less than" may be replaced with "less than."

[0042] The terms 'station', 'terminal', or 'device' as used herein may be referred to as a mobile station (MS), user equipment (UE), user terminal (UT), wireless terminal, access terminal (AT), terminal, subscriber unit, subscriber station (SS), wireless device, wireless communication device, wireless transmit / receive unit (WTRU), mobile node, mobile, or other terms. Various embodiments of a terminal may include a cellular telephone, a smartphone with wireless communication capabilities, a personal digital assistant (PDA) with wireless communication capabilities, a wireless modem, a portable computer with wireless communication capabilities, a photographic device such as a digital camera with wireless communication capabilities, a gaming device with wireless communication capabilities, a music storage and playback appliance with wireless communication capabilities, an internet appliance capable of wireless internet access and browsing, as well as portable units or terminals integrating combinations of such capabilities. Additionally, the terminal may include, but is not limited to, M2M (Machine to Machine) terminals and MTC (Machine Type Communication) terminals / devices. In this specification, the terminal may be referred to as an electronic device or simply a device.

[0043] Exemplary embodiments are described below in relation to Wireless Local Area Network (WLAN) systems solely for the sake of simplicity. It should be understood that the exemplary embodiments are equally applicable to systems using signals of one or more wired standards or protocols (e.g., Ethernet and / or HomePlug / PLC standards), as well as other wireless networks (e.g., cellular networks, pico networks, femto networks, satellite networks). As used herein, the terms “WLAN” and “Wi-Fi®” may include communications controlled by the IEEE 802.11 family of standards, BLUETOOTH®, HiperLAN (a set of wireless standards comparable to IEEE 802.11 standards, mainly used in Europe), and other technologies having a relatively short wireless range. Accordingly, the terms “WLAN” and “Wi-Fi” may be used interchangeably herein. Additionally, although the following describes an infrastructure WLAN system comprising one or more access points (APs) and multiple wireless stations (STAs), exemplary embodiments are equally applicable to other WLAN systems, such as multiple WLANs, peer-to-peer (or independent basic service set) systems, Wi-Fi Direct systems and / or hotspots.

[0044] Additionally, while this specification describes the exchange of data frames between wireless devices, exemplary embodiments may be applied to the exchange of any data unit, packet, and / or frame between wireless devices. Accordingly, the term “frame” may include any frame, packet, or data unit such as, for example, protocol data units (PDUs), MAC (media access control) protocol data units (MPDUs), and PLCP (physical layer convergence procedure) protocol data units (PPDUs). The term “A-MPDU” may mean aggregated MPDUs.

[0045] In the following description, many specific details, such as examples of specific components, circuits, and processes, are presented to provide a thorough understanding of the present disclosure. As used herein, the term “connected” means being directly connected or being connected through one or more intervening components or circuits. The term “connected access point” means an access point to which a given station is currently associated and / or connected (e.g., there exists a communication channel or link established between the access point and the given station). Additionally, in the following description and for illustrative purposes, specific nomenclature is presented to provide a thorough understanding of exemplary embodiments. However, it will be apparent to those skilled in the art that these specific details may not be necessary to carry out the exemplary embodiments. In other cases, to avoid obscuring the present disclosure, well-known circuits and devices are illustrated in block diagram form.

[0046] Specific terms used in the following description are provided to aid in understanding the present disclosure, and the use of such specific terms may be modified in other forms without departing from the technical spirit of the present disclosure.

[0047] The operating principles of the present disclosure will be described in detail below with reference to the attached drawings. In describing the present disclosure below, specific descriptions of related known functions or configurations will be omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the present disclosure. Furthermore, the terms described below are defined in consideration of their functions in the present disclosure, and these may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0048] FIG. 1 is a drawing for illustrating a short-range communication connection type of an electronic device that can be applied to the present disclosure.

[0049] According to various embodiments, with reference to FIG. 1, an electronic device (100) may be connected to an access point (AP) (140) based on a plurality of communication methods based on Wi-Fi. According to various embodiments, the electronic device (100) may include a processor (120) and a communication module (130).

[0050] According to various embodiments, the communication module (130) can receive a communication signal from the outside or transmit a communication signal to the outside based on a Wi-Fi communication method (e.g., IEEE 802.11be). For example, the communication module (130) can operate based on at least one of the Wi-Fi communication methods IEEE 802.11ac, 802.11ax, 802.11be, or 802.11bn, and in particular, IEEE 802.11be or 802.11bn supports a wider bandwidth, higher data throughput, and shorter latency compared to IEEE 802.11ax, thereby improving performance.

[0051] According to various embodiments, the communication module (130) may include a transceiver (131) for transmitting and receiving data with an external device and a communication processor (133) (e.g., a communication processor (not shown), or a short-range wireless communication module (e.g., a Wi-Fi chipset)). According to various embodiments, the communication module (130) may further include memory.

[0052] According to various embodiments, the transceiver (131) can convert a baseband transmission signal into a wireless signal or convert a received wireless signal into a baseband reception signal.

[0053] According to various embodiments, the communication module (130) may further include, in addition to the transceiver (131) and the communication processor (133), components for orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA), e.g., a modulator, a digital-analog converter, a frequency converter, an A / D converter, an amplifier, and / or a demodulator.

[0054] Although not illustrated, according to various embodiments, the electronic device (100) may be electrically connected to a communication module of an access point (140) and may include at least one antenna module that supports a communication protocol and / or frequency band supported by the communication module of the access point (140).

[0055] According to various embodiments, the communication processor (133) can control the transceiver (131) to form a communication connection with the access point (140). For example, the communication connection may include a Wi-Fi network. For example, the communication processor (133) can control the transceiver (131) to form a wireless connection with the access point (140) using a wireless local area network (WLAN) standard in the 2.4 GHz, 5 GHz, or 6 GHz band, such as an IEEE 802.11ac, 802.11ax, 802.11be, or 802.11bn system. Alternatively, the communication processor (133) can control the transceiver (131) to form a wireless connection with the access point (140) using a WLAN standard in the 60 GHz band, such as an IEEE 802.11ad or 802.11ay.

[0056] According to various embodiments, a method of communicating between an electronic device (100) and an access point (140) using a wireless local area network (WLAN) standard may be referred to as a communication method based on STA mode.

[0057] According to various embodiments, the processor (120) may include an application processor. The processor (120) may perform a specified operation of the electronic device (100) or control other hardware (e.g., a communication module (130)) to perform a specified operation.

[0058] According to various embodiments, the access point (140) may support the operation of transmitting data to an external network and / or the operation of the multiple electronic devices (e.g., electronic device (100)) receiving data from an external network based on the connection between the multiple electronic devices (e.g., electronic device (100)) and an external network (e.g., Internet, external LAN, or cellular network).

[0059] According to various embodiments, the access point (140) may be a wireless router. The access point (140) may be a dedicated wireless router or a general-purpose device that supports a mobile hotspot function, and there are no limitations on its implementation. For example, the access point (140) may include the same components (e.g., a processor and / or a communication module) as the electronic device (100).

[0060] According to various embodiments, the access point (140) may transmit and receive data with an external device, such as a server or an electronic device (100). For example, the access point (140) may transmit at least some of the data received from the server to the electronic device (100). According to various embodiments, the access point (140) and the electronic device (100) may transmit and receive UL (uplink) / DL (downlink) data during an operation period. For example, the access point (140) may transmit traffic to the electronic device (100) only during an operation period set based on schedule information received from the electronic device (100).

[0061] FIG. 2 is a diagram illustrating the operation of an access point and a station for establishing a Wi-Fi connection according to one embodiment of the present disclosure.

[0062] As illustrated in FIG. 1, the access point can communicate with the station based on Wi-Fi. The station can be implemented as the electronic device (100) of FIG. 1. The station may be a terminal that supports Wi-Fi communication according to the IEEE 802.11 standard (or a terminal having a Wi-Fi interface).

[0063] A station may transmit (or broadcast) a probe request frame to an access point. According to one embodiment, the probe request message may be a frame for the station to search for nearby access points. According to one embodiment, the probe request frame may include information regarding at least one communication capability supported by the station. According to one embodiment, the station may receive a beacon frame from an access point and transmit a probe request frame to the access point based on the information contained in the beacon frame. The beacon frame is one of the management frames in IEEE 802.11 and may be transmitted periodically to announce the presence of a wireless network and to allow a scanning STA to find the wireless network and join the wireless network. The access point may transmit a probe response frame in response to the probe request frame.

[0064] Upon receiving the probe response frame, the station may transmit an authentication request frame to the access point. The access point transmits an authentication response frame to the station in response to the authentication request frame, and the authentication procedure between the access point and the station may be completed. According to one embodiment, the authentication procedure for transmitting and receiving the authentication request frame and the authentication response frame may be a process of authenticating by selecting the channel with the strongest reception strength among the frames received during the channel search process. According to one embodiment, the station and the access point may negotiate the encryption method of the authentication procedure through the authentication procedure.

[0065] Once the authentication process is complete, the station may send an association request frame to the access point to perform an association setup for the access point. According to one embodiment, the association request frame may include information regarding at least one capability to be used for data communication between the station and the access point (e.g., according to the IEEE 802.11 standard). The access point may generate an association ID (AID) for the station and send an association response frame to the station.

[0066] FIG. 3 is a drawing for illustrating an example of a short-range communication connection type of an electronic device according to one embodiment of the present disclosure.

[0067] Referring to FIG. 3, the wireless communication system (300) may include an access point (310), client electronic devices (330, 332, 334, 336) corresponding to the station, and a wireless local area network (WLAN) (305).

[0068] A wireless communication system (300) may be formed by an access point (310) that provides a wireless communication channel or link to one or more stations (STA) (330, 332, 334, 336).

[0069] An access point (310) is assigned a unique media access control (MAC) address. The WLAN (305), depicted as a circular shape in FIG. 3, is depicted as a basic service set (BSS), which is a basic building block of an IEEE 802.11 system; however, in other exemplary embodiments, the WLAN (305) may be an independent basic service set (IBSS) network or a peer-to-peer (P2P) network (e.g., operating according to Wi-Fi Direct protocols). The circular shape of the WLAN (305) depicted in FIG. 3 may also be understood as representing a coverage area where stations included in the BSS maintain communication. This area may be referred to as a Basic Service Area (BSA). When stations (330, 332, 334, 336) move out of the BSA, they are unable to communicate directly with access points or other stations within the BSA. The access point (310) may be a dedicated wireless router or a station that supports a mobile hotspot function, in which case the access point (310) may be referred to as an AP STA.

[0070] The stations (330, 332, 334, 336) are devices that operate according to the Medium Access Control (MAC) / PHY specifications of IEEE 802.11. Unless the function of the station is individually distinguished from the access point, the station may include AP STAs and non-AP STAs. However, when communication is performed between the STA and the AP, the STA may be understood as a non-AP STA. If the station supports a mobile hotspot function and operates like an access point (310), the station may be understood as an AP STA.

[0071] The stations (330, 332, 334, 336) may be any suitable Wi-Fi-enabled wireless device or electronic device, including, for example, a cell phone, a personal digital assistant (PDA), a tablet device, a laptop computer, etc. The stations (330, 332, 334, 336) may also be referred to as user equipment (UE), subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, electronic device, or any other suitable technical term.

[0072] A "point coordination function (PCF) transmission method" and a "distributed coordination function (DCF) transmission method" can be used as a method to perform data transmission of a plurality of wireless stations (330, 332, 334, 336) corresponding to UL clients connected to the access point (310) shown in FIG. 3.

[0073] "PCF (point coordination function) method transmission" refers to a transmission method in which the access point directly asks multiple wireless stations and waits for data transmission.

[0074] "Distributed coordination function (DCF) transmission" refers to a transmission method in which a wireless station detects and waits in advance to avoid collisions before transmitting data in an environment where multiple wireless stations compete to transmit data.

[0075] The above DCF transmission method is a concept for providing services during contention periods, and to request channel usage, traffic priorities can be divided into IFS (inter-frame space) to handle waiting times. That is, priority can be determined by the size of the waiting time, and the shorter the time, the waiting time may be for a packet with higher priority. The above IFS may include SIFS (short IFS), PIFS (PCF IFS), and DIFS (DCF IFS).

[0076] The above SIFS has the shortest period and high priority, and can be used primarily as a waiting time for control information. The above PIFS has a medium-length period and can have a medium level of priority. The above DIFS has the longest time interval compared to SIFS and PIFS, has low priority, and is mainly used as a waiting time for channel checking. That is, during the DIFS period, the channel is listened to (or waited for). If the channel is busy during the DIFS period, transmission may be delayed.

[0077] However, since this DCF method does not consider the priority between STAs, it has the problem of being difficult to support various forms of data transmission and QoS (Quality of Service); therefore, HCF (hybrid coordination function) was introduced. HCF is based on the aforementioned DCF and PCF (point coordination function). PCF refers to a polling-based synchronous access method that periodically polls all receiving APs and / or STAs so that they can receive data frames. HCF includes EDCA (enhanced distributed channel access), a contention-based channel access method, and HCCA (HCF controlled channel access), a contention-based method utilizing a polling mechanism. Furthermore, HCF includes a media access mechanism to enhance the QoS of the WLAN and can transmit QoS data during both the contention period (CP) and the contention-free period (CFP).

[0078] FIG. 4 is a drawing illustrating an example of a frame structure used in an IEEE 802.11 system according to one embodiment of the present disclosure.

[0079] The PPDU (physical layer protocol data unit) format may be configured to include at least one of the STF (short training field), LTF (long training field), SIG (signal) field, and data field. The most basic (e.g., non-HT (high throughput)) PPDU frame format may consist only of L-STF (legacy-STF), L-LTF (legacy-LTF), SIG field, and data field.

[0080] STF can be used for frame timing acquisition, automatic gain control (AGC), diversity detection, and coarse frequency / time synchronization. LTF can be used for fine frequency / time synchronization and channel estimation. STF and LTF together can be referred to as the PLCP preamble, and the PLCP preamble can be described as a signal for synchronization and channel estimation in the OFDM physical layer.

[0081] The SIG field can be used to transmit control information for demodulation and decoding of the data field. The SIG field may include information regarding the data rate and data length. Additionally, the SIG field may include a parity bit, a SIG TAIL bit, etc.

[0082] The data field may include a SERVICE field, a PSDU (physical layer service data unit), and PPDU TAIL bits, and may also include padding bits if necessary. Some bits of the SERVICE field may be used for the descrambler at the receiver. The PSDU corresponds to the MPDU (mac protocol data unit) defined at the MAC layer and may contain data generated or used by the upper layer. The PPDU TAIL bits may be used to return the encoder to a state of 0. Padding bits may be used to adjust the length of the data field to a predetermined unit.

[0083] MPDUs are defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a frame check sequence (FCS). A MAC frame is composed of an MPDU and can be transmitted or received through the PSDU of the data portion in the PPDU format.

[0084] The MAC header is defined as an area including a frame control field, a duration / ID field, an address 1 field, an address 2 field, an address 3 field, a sequence control field, an address 4 field, a QoS control field, and an HT control field.

[0085] The frame control field contains information about the characteristics of the corresponding MAC frame. The interval / identifier field can be implemented to have different values ​​depending on the type and subtype of the corresponding MAC frame.

[0086] The address 1 to address 4 fields are used to indicate the BSSID, source address (SA), destination address (DA), transmitting address (TA) representing the transmitting STA address, and receiving address (RA) representing the receiving STA address.

[0087] The sequence control field is configured to include a sequence number and a fragment number. The sequence number may indicate the sequence number assigned to the corresponding MAC frame. The fragment number may indicate the number of each fragment of the corresponding MAC frame.

[0088] The QoS control field contains information related to QoS. The QoS control field may be included if the Subtype subfield indicates a QoS data frame. The HT control field contains control information related to HT and / or VHT transmission and reception techniques.

[0089] The frame body is defined as the MAC payload, contains the data to be transmitted from the upper layer, and has a variable size. For example, the maximum MPDU size can be 11,454 octets, and the maximum PPDU size can be 5.484 ms.

[0090] FCS is defined as the MAC footer and is used for error detection in MAC frames.

[0091] The first three fields (frame control field, interval / identifier field, and address 1 field) and the very last field (FCS field) constitute the minimum frame format and are present in all frames. Other fields may exist only in specific frame types.

[0092] The following describes the network allocation vector (NAV) used in wireless LAN networks.

[0093] The CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, where APs and / or STAs directly sense the medium. Virtual carrier sensing is intended to compensate for problems that may occur in medium access, such as hidden node issues. For virtual carrier sensing, the MAC of a wireless LAN system may utilize NAV. NAV is a value that indicates to other APs and / or STAs the time remaining until the medium becomes available, provided that the AP and / or STA currently using or authorized to use the medium is using it. Therefore, the value set as NAV corresponds to the period during which the medium is scheduled to be used by the AP and / or STA transmitting the frame, and the STA receiving the NAV value is prohibited from accessing the medium during that period. NAV can be set, for example, based on the value of the duration field in the frame's MAC header.

[0094] FIG. 5 is a diagram illustrating an example of a network allocation vector (NAV) setting according to one embodiment of the present disclosure.

[0095] Referring to FIG. 5, the source STA (source STA, 500) transmits an RTS frame after DIFS, and the destination STA (destination STA, 510) transmits a CTS frame after SIFS. The destination STA (510), designated as the recipient via the RTS frame, does not set the NAV. Some of the remaining STAs (620) receive the RTS frame and set the NAV (530), while others receive the CTS frame and set the NAV (540).

[0096] If a CTS frame (e.g., PHY-RXSTART.indication primitive) is not received within a certain period from the time when an RTS frame is received (e.g., when a MAC receives the PHY-RXEND.indication primitive corresponding to the RTS frame), STAs that set or updated the NAV through the RTS frame may reset the NAV (e.g., 0). The certain period may be (2*aSIFSTime + CTS_Time + aRxPHYStartDelay + 2*aSlotTime). CTS_Time may be calculated based on the length and data rate of the CTS frame indicated by the RTS frame. The above certain period may be the NAVTimeout period.

[0097] In FIG. 5, for convenience, NAV setting or updating is exemplified through an RTS frame or a CTS frame, but NAV setting / resetting / updating may also be performed based on the interval field of various other frames, such as non-HT PPDU, HT PPDU, VHT PPDU, or HE PPDU (for example, the interval field within the MAC header of a MAC frame).

[0098] In addition, 802.11ax introduced basic NAV and intra-BSS NAV. Basic NAV is always set (mandatory) to NAV based on frames transmitted by APs or STAs other than itself, while intra-BSS NAV is optionally set to NAV based on frames transmitted by the BSS to which it belongs. An AP or STA can access the medium when both NAV timers have expired (or after the NAV time interval has elapsed).

[0099] The following describes TXOP. TXOP (transmission opportunity) was newly introduced in 802.11e MACs to guarantee QoS and increase channel utilization. To guarantee QoS, TXOP can be used to allocate an opportunity for priority transmission when two or more packets belong to the same AC (access category).

[0100] FIG. 6 is a drawing illustrating an example of a TXOP (transmission opportunity) according to one embodiment of the present disclosure.

[0101] STAs participating in QoS transmission can obtain a TXOP that allows them to transmit traffic for a certain period by using two channel access methods: EDCA (enhanced distributed channel access) and HCCA (HCF controlled channel access). Obtaining a TXOP is possible by succeeding in an EDCA competition or by receiving a QoS CF-Poll (Contention-Free Poll) frame from an AP; the former is referred to as an EDCA TXOP, and the latter as a Polled TXOP. In this way, the concept of a TXOP can be used to grant a specific amount of time for any STA to transmit a frame, or to forcibly limit the transmission time.

[0102] The transmission start time and maximum transmission time of a TXOP are determined by the AP, and this is notified to the STA by a beacon frame in the case of an EDCA TXOP, and by a QoS CF-Poll frame in the case of a Polled TXOP.

[0103] NAV can be understood as a type of timer designed to protect the TXOP of a transmitting STA (e.g., a TXOP holder). An STA can protect the TXOPs of other STAs by not performing channel access during the period when the NAV set for it is valid. In current wireless LAN systems, the TXOP duration is set via the duration field of the MAC header. That is, the TXOP holder and the TXOP responder (e.g., an Rx STA) transmit frames containing all the TXOP information necessary for the transmission and reception of the frames in the duration field of the frames being exchanged between them. Third-party STAs that are not the TXOP holder or TXOP responder (e.g., third-party STAs) check the duration field of the frames exchanged between the TXOP holder and the TXOP responder, and delay channel usage until the NAV period expires by setting or updating the NAV.

[0104] The 802.11be standard is described below. Also known as EHT (extremely high throughput), 802.11be operates across the 2.4, 5, and 6 GHz bands. It is being developed to provide low latency and high network throughput by introducing a 320 MHz wide bandwidth, 4096QAM, multiple resource units (RUs), and multi-link operation (MLO), offering speeds up to 46 Gbps—4.8 times faster than WiFi 6. Specifically, 802.11be provides a 320 MHz wide bandwidth in the 6 GHz band and can transmit data via MU-MIMO, which offers 16 spatial streams in both uplink and downlink. It also achieves high transmission efficiency by adopting 4096QAM. Furthermore, it features enhanced spectrum efficiency by flexibly performing spectrum resource scheduling through multiple RUs, and the ability to simultaneously transmit and receive data across various frequency bands and channels through multi-link operation.

[0105] The following describes OBSS (overlapping basic service set). As the number of users increases, the performance of existing wireless LAN networks, such as transmission rates, decreases significantly. This is because wireless LAN systems fundamentally utilize the CSMA / CA method, which corresponds to time division access control; therefore, when an adjacent network is detected, the frequency resources of the same band are shared for the duration of the adjacent network's activity.

[0106] Currently, it is common for multiple APs to operate in specific areas, and in such cases, wireless LAN network performance degradation occurs due to coverage overlap between APs. This is because the APs of each BSS and the STAs connected to them are affected by signals from adjacent BSSs, leading to interference and a reduction in transmission rates caused by collisions between signals transmitted simultaneously. BSSs that can affect signal transmission in this way (or have overlapping coverage) can be referred to as overlapping BSSs (OBSS). To address this problem, interference avoidance techniques are being researched, such as dividing the bandwidth available to each user so that it does not overlap or performing channel switching to unused channels, as well as interference alignment techniques that minimize the impact of interference even when using the same bandwidth.

[0107] FIG. 7 is a drawing illustrating an example of non-primary channel access (NPCA) according to one embodiment of the present disclosure.

[0108] FIG. 7 illustrates a wideband channel configured with a 20 MHz primary channel (primary 20 MHz channel) and a plurality of 20 MHz secondary channels (secondary 20 MHz channels). This is for convenience of explanation and the present disclosure is not limited thereto.

[0109] The primary channel is a common channel operated by all STAs that are members of the BSS. For example, in a 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 80 + 80 MHz BSS, the primary channel may be the primary 20 MHz channel.

[0110] A secondary channel is a channel associated with a primary channel and is used to create a channel wider than the primary channel. The secondary channel may be a channel included in the bandwidth excluding the primary 20 MHz channel from the BSS channel bandwidth. As another example, if the BSS channel bandwidth is 40 MHz, the secondary channel may be a 20 MHz channel excluding the primary 20 MHz channel from the BSS channel bandwidth. As yet another example, if the BSS channel is 80 MHz, the secondary channel may be a 40 MHz channel remaining excluding the 40 MHz including the primary 20 MHz from the BSS channel bandwidth.

[0111] According to the current 801.11 standard, for any transmission (e.g., transmission on 20 / 40 / 80 / 160 / 320 MHz channels), the primary channel (primary 20 MHz channel) must be idle to access a wideband channel larger than 20 MHz. Therefore, if the primary channel is busy, the AP / STA cannot transmit on any idle secondary channel. In other words, if the primary channel is busy, transmission cannot be performed on that secondary channel even if it is idle.

[0112] For example, referring to Fig. 7(a), transmission cannot be performed even if the secondary channel is available, if the primary channel is busy.

[0113] For example, the primary channel may be busy due to interference from a 20 MHz PPDU corresponding to an OBSS (overlapping BSS), and in this case, transmission cannot be performed even if 60 MHz secondary channels are available.

[0114] For example, the primary channel may be busy due to interference from a 40 MHz PPDU corresponding to OBSS, and in this case, transmission cannot be performed even if 40 MHz secondary channels are available.

[0115] In other words, according to the current IEEE 802.11 standard, when the primary channel is idle, the STA can transmit packets. That is, when the primary channel is idle, the STA can perform transmission (e.g., transmission of an 80MHz PPDU) using both the primary and secondary channels. This applies equally to the STA's UL (uplink) transmission as well as the AP's DL (downlink) transmission.

[0116] Therefore, current secondary channel access mechanisms (or schemes) are inefficient for wideband channels (e.g., 160 MHz channels, 320 MHz channels) or large bandwidths, and thus a better secondary channel access mechanism (or scheme) is needed to fully utilize wideband channels.

[0117] NPCA (non-primary channel access) is being discussed as a solution to the aforementioned problem. NPCA can be triggered based on OBSS PPDU and / or OBSS TXOP. According to NPCA, if the primary channel is busy and a secondary channel is available, the AP / STA can transmit on the available secondary channel.

[0118] An NPCA primary channel may be defined among (or within) secondary channels. The NPCA primary channel may be a channel where channel access (e.g., EDCA) is performed while the primary channel is busy. That is, the NPCA primary channel may be a channel within the secondary channels where channel access is performed while the primary channel is busy. For example, the NPCA primary channel may have a bandwidth of 20 MHz, but this is for illustrative purposes only and does not limit the scope of the disclosure. The NPCA primary channel may be named an anchor channel, but the disclosure is not limited to this specific designation.

[0119] For example, referring to Fig. 7(b), when the primary channel is busy, transmission can be performed on available secondary channels.

[0120] For example, if the primary channel is busy due to interference by a 20 MHz PPDU corresponding to OBSS, the STA can transmit packets (e.g., 60 MHz PPDU) on available secondary channels while the primary channel is busy. Channel access can be performed on an anchor channel within the secondary channels, and accordingly, packets can be transmitted on the secondary channels when the anchor channel is idle. This applies equally to UL transmission by the STA as well as DL transmission by the AP.

[0121] For example, if the primary channel is busy due to interference by a 40 MHz PPDU corresponding to OBSS, the STA can transmit packets (e.g., 40 MHz PPDU) on available secondary channels while the primary channel is busy. Channel access can be performed on an anchor channel within the secondary channels, and accordingly, packets can be transmitted on the secondary channels when the anchor channel is idle. This applies equally to UL transmission by the STA as well as DL transmission by the AP.

[0122] In the description of an embodiment of the present disclosure, NPCA AP may mean an AP having the capability to perform NPCA (or an AP that performs / is capable of performing operations related to NPCA), and NPCA STA may mean an STA that is associated with the NPCA AP and has the capability to perform NPCA (or an STA that performs / is capable of performing operations related to NPCA). Unless specifically stated otherwise, AP, NPCA AP, STA, and NPCA STA may be used interchangeably in the present disclosure. In particular, NPCA AP and NPCA STA used for the following description each mean an AP and / or STA that has the capability to perform NPCA, and their meaning is not limited to an AP and / or STA that is performing NPCA at the time of description. That is, NPCA AP may be a STA that supports mobile access point functions, and in this case, NPCA AP may be referred to as NPCA STA. That is, an NPCA STA may include non-AP STAs and APs that have the capability to perform NPCA.

[0123] When the OBSS initiates an OBSS TXOP, the NPCA AP and / or NPCA STA within the BSS may set BasicNAV and perform NPCA. For example, BasicNAV may be set for the primary channel. For example, when it is identified that the OBSS has initiated an OBSS TXOP based on an RTS-CTS exchange, the NPCA AP and / or NPCA STA within the BSS may set BasicNAV and perform NPCA. Here, whether to perform NPCA may be identified based on a comparison between the OBSS TXOP and a specific duration threshold. For example, if the OBSS TXOP is shorter than (or less than) the specific duration threshold, NPCA may not be performed. Conversely, if the OBSS TXOP is longer than (or greater than) the specific duration threshold, NPCA may be performed. This takes into account that when the OBSS TXOP is relatively short, it may be advantageous to wait until the OBSS TXOP ends rather than to perform an operation based on NPCA.

[0124] Secondary channels on which NPCA operates between NPCA APs and / or NPCA STAs within the BSS, and anchor channels (e.g., 20 MHz anchor channels) for performing channel access (e.g., EDCA) procedures within the secondary channels, may be pre-configured and / or pre-agreed upon. The secondary channels on which NPCA operates may be named NPCHs (non-primary channels), but the present disclosure is not limited to these specific names.

[0125] The operation of the NPCA AP can be as follows.

[0126] An NPCA AP may not perform NPCA within a band outside the operating bandwidth. That is, an NPCA AP can perform NPCA within the operating bandwidth.

[0127] NPCA AP can perform NPCA if the secondary channel is idle during the interval of PIFS immediately preceding the starting point of OBSS TXOP.

[0128] If the NPCA AP has a separate NAV timer, that is, if a separate NPCH NAV timer for the anchor channel is set, and the NPCH NAV timer has a non-zero value, the NPCA AP may not be able to initiate a TXOP within the NPCH. If the NPCA AP has a separate NAV timer, that is, if a separate NPCH NAV timer for the anchor channel is set, and the NPCH NAV timer is zero, the NPCA AP may initiate a TXOP within the NPCH.

[0129] An NPCA AP can perform channel access (e.g., EDCA contention) on an anchor channel where OBSS transmissions do not overlap, and the remaining channels within the NPCH (excluding the anchor channel) can be accessed by ED (energy detection). For example, if the anchor channel is idle just before the backoff counter expires, it can be accessed on the remaining channels.

[0130] The operation of NPCA STA can be as follows.

[0131] An NPCA STA can switch the operating bandwidth to perform NPCA. Unlike an NPCA AP, which does not perform NPCA in bands outside the operating bandwidth, an NPCA STA can perform NPCA by changing the operating bandwidth. For example, an NPCA STA can perform NPCA by changing to an operating bandwidth according to the instructions / configurations of the AP and / or a predefined / agreed-upon bandwidth.

[0132] The NPCA capability of an STA and / or the on / off status of its NPCA capability can be established through prior information and / or message exchange. The STA and AP can verify whether NPCA can be performed, i.e., NPCA capability, by exchanging Probe requests and Probe responses or Association requests and Association responses. Subsequently, APs and STAs capable of performing NPCA can exchange information on visible (detected) surrounding OBSS (e.g., MAC addresses or color information of OBSS APs and STAs) to establish a list of OBSSs that are not in a hidden relationship, and perform NPCA in cases such as when transmission occurs due to the corresponding OBSS. When performing NPCA, the anchor channel for EDCA execution and the NPCH capable of transmitting data including the anchor channel can be established in advance through information exchange between the NPCA AP and the NPCA STA. NPCA is a representative communication method for high-speed data transmission (e.g., UHR (ultra high rate)) to improve resource usage efficiency discussed in the IEEE 802.11 standard.

[0133] Meanwhile, when performing NPCA, one of the transmission-related modes in the NPCA primary channel may be operated.

[0134] - Mode 1: Untriggered UL transmission mode where all NPCA STAs (i.e., including NPCA APs and NPCA non-AP STAs) can access the NPCA primary channel (i.e., perform untriggered transmissions).

[0135] - Mode 2: A mode where only NPCA APs can perform triggered transmissions, and NPCA STAs (i.e., NPCA non-AP STAs) cannot perform untriggered uplink transmissions.

[0136] The transmission-related modes in the above NPCA primary channel can be enabled / disabled by the AP.

[0137] When performing NPCA, it should not be assumed that an STA can detect or decode frames of the secondary channel simultaneously with the primary channel, and obtain the NAV of the secondary channel simultaneously. A BSS may have a single NPCA primary channel, and on that channel, an STA may compete if the primary channel is busy due to OBSS traffic, etc.

[0138] Meanwhile, the NPCA STA can instruct the peer NPCA STA with the following switching delay information.

[0139] - NPCA switching delay: This represents the time required to switch the operating channel from the BSS primary channel to the NPCA primary channel.

[0140] - NPCA switch back delay: This represents the time required to switch the operating channel from the NPCA primary channel to the BSS primary channel.

[0141] The above delay value can be represented by a predefined interval (resolution) within a predefined range and by a corresponding number of bits. For example, the above delay value can be set to a range from 0μs to 256μs with an interval of 4μs, in which case the delay value can be represented by a 6-bit or 7-bit value.

[0142] In one embodiment, the switching delay information can be transmitted by the NPCA STA to the AP by including it in an association request frame.

[0143] FIG. 8 is a diagram illustrating an example of operation between an NPCA AP and a plurality of NPCA STAs during NPCA operation according to an embodiment of the present disclosure.

[0144] FIG. 8 is a diagram illustrating an example of an NPCA AP performing a multi-user operation during an NPCA operation according to an embodiment of the present disclosure.

[0145] FIG. 8 illustrates, as an example, a channel (P80) with a bandwidth of 80 MHz including a primary channel and a channel (S80) with a bandwidth of 80 MHz including a secondary channel of 80 MHz among the total bandwidth of 160 MHz for NPCA AP and NPCA STA, but does not limit the scope of the present disclosure. Unless otherwise specifically stated below, the channel with a bandwidth of 80 MHz including a primary channel (P80) in the present disclosure may be used interchangeably with the primary channel, and the channel with a bandwidth of 80 MHz including a secondary channel (S80) may be used interchangeably with the secondary channel or NPCH.

[0146] Referring to FIG. 8, an OBSS AP or an STA associated with an OBSS AP can perform OBSS ICF (initial control frame)-ICR (initial control response) exchange in a bandwidth including a primary channel and transmit or receive one or more OBSS PPDUs and one or more OBSS BAs (block ACKs) within an OBSS TXOP.

[0147] The NPCA AP and / or NPCA STA identify that the primary channel (P80) is busy via the OBSS TXOP, and if the secondary channel (S80) is available, they can perform NPCA on the secondary channel (S80). In one embodiment, the NPCA AP transmits a trigger frame (TF), and the NPCA STA transmits a response thereto. As a result, an NPCA TXOP in which the NPCA AP becomes the holder can be initiated. In the NPCA TXOP, the NPCA AP transmits one or more NPCA PPDUs, and the NPCA STA transmits block ACK (BA) information for the NPCA PPDUs. In addition, in NPCA TXOP, NPCA STA transmits one or more NPCA PPDUs, and NPCA AP can transmit BA (block ACK) information for NPCA PPDUs.

[0148] Meanwhile, when an NPCA STA (i.e., including NPCA AP STA and NPCA non-AP STA) detects a transmission or OBSS TXOP from an OBSS AP or a STA associated with an OBSS AP and switches to the NPCA primary channel, it may not be able to initiate transmission to the peer NPCA STA from the switch start time until the switching delay of the peer NPCA STA expires. That is, the NPCA STA must wait to transmit to the peer NPCA STA until the switching delay of the peer NPCA STA expires, and in this case, the NPCA STA may include an NPCA AP.

[0149] Accordingly, with reference to FIG. 8, even when the NPCA AP simultaneously schedules multiple NPCA STAs (i.e., multi-user operation) by transmitting an ICF on the NPCA primary channel to multiple NPCA STAs (STA1, STA2, STA3) corresponding to the NPCA AP's peer NPCA STAs, the NPCA AP can access the NPCA primary channel after the longest NPCA switching delay among the switching delays of the scheduled NPCA STAs has expired. That is, the time at which the NPCA AP participates in EDCA competition on the NPCA primary channel or starts transmission can be delayed until after the longest NPCA switching delay among the scheduled NPCA STAs (i.e., the switching delay of STA3 in FIG. 8) has expired.

[0150] Meanwhile, when the transmission-related mode in the NPCA channel described above is operated as untriggered UL transmission (i.e., the first mode), an NPCA non-AP STA can participate in EDCA competition in the NPCA primary channel without control (e.g., trigger) by an NPCA AP and initiate transmission (or initiate a TXOP).

[0151] Referring to FIG. 8, a peer NPCA STA of an NPCA STA (i.e., STA1 or STA2) having a switching delay shorter than the longest NPCA switching delay (i.e., the switching delay of STA3) may be an NPCA AP in FIG. 8. Since the switching delay of an AP is generally shorter than that of a non-AP STA, STA1 or STA2 may initiate transmission (i.e., participate in EDCA competition) before the NPCA AP.

[0152] In this case, the NPCA AP may fail to acquire the TXOP in the contention period because it joins the EDCA competition late or starts transmission late compared to STA1 and STA2, which have a switching delay shorter than the longest NPCA switching delay (i.e., the switching delay of STA3).

[0153] Accordingly, the present disclosure proposes a method for restricting the initiation of transmission by NPCA STAs performing NPCA during the channel access delay by setting a channel access delay in an NPCA primary channel by an NPCA AP.

[0154] In one embodiment, an NPCA AP may set a channel access delay in an NPCA primary channel, and the channel access delay may refer to the time that NPCA STAs, including the AP, wait to initiate transmission or participate in EDCA competition in an NPCA primary channel.

[0155] FIG. 9 is a diagram illustrating an example of field or element formats within a frame used to transmit channel access delay-related information from an NPCA AP to an NPCA STA in a BSS according to one embodiment of the present disclosure.

[0156] FIG. 9(a) is a drawing illustrating an example of a UHR Operation element format, FIG. 9(b) is a drawing illustrating an example of a UHR Operation Parameters field format, and FIG. 9(c) is a drawing illustrating an example of an NPCA element format (or NPCA Operation Information field format).

[0157] Referring to FIG. 9(a), the UHR Operation element format may include at least one of an element ID field, a length field, an element ID extension field, a UHR Operation parameters field, a Basic UHR MCS And NSS set field, and a UHR Operation Information field.

[0158] The element ID and element ID extension fields can indicate that the frame is a UHR Operation frame.

[0159] The length field can indicate the length of the frame.

[0160] The UHR Operation Parameters field is a field containing setting parameters used for UHR operation, and Figure 9 (b) shows an example thereof.

[0161] The Basic UHR MCS And NSS set field can represent the modulation and coding scheme (MCS) and number of spatial streams (NSS) used for UHR operation.

[0162] The UHR Operation Information field can represent information used for UHR operation.

[0163] Referring to FIG. 9(b), the UHR Operation Parameters field may include an NPCA Operation Information Present field, and the NPCA Operation Information Present field may indicate whether an NPCA operation has been enabled from the AP and / or whether an NPCA Operation Information field exists in the UHR Operation Information field. In one embodiment, the NPCA Operation Information field may be defined as an NPCA element.

[0164] FIG. 9(c) illustrates an example of an NPCA element format or an NPCA Operation Information field format that may include channel access delay related information. In one embodiment, the NPCA Operation Information field described in FIG. 9(b) may have the format shown in FIG. 9(c) or may be defined as an NPCA element of the format shown in FIG. 9(c).

[0165] In one embodiment, the NPCA element may be included in the UHR Operation element. In one embodiment, the NPCA element may be included in the management frame.

[0166] In one embodiment, the NPCA AP may include operating parameters and / or information necessary for NPCA operation in the NPCA element or NPCA Operation Information field shown in FIG. 9 (c) and notify or share them within the BSS.

[0167] Referring to FIG. 9(c), the NPCA element format or NPCA Operation Information field format may include at least one of the NPCA primary channel field, the NPCA minimum duration threshold field, the AP's switching delay field, and the AP's switching back delay field. Referring to FIG. 9(c), the NPCA element format or NPCA Operation Information field format may include a channel access delay on NPCA primary channel field.

[0168] In one embodiment, the NPCA primary channel field may include information about the NPCA primary channel of the AP. The NPCA primary channel may be included in the BSS operating channel width. The information about the NPCA primary channel may indicate the channel number of a secondary channel within the BSS bandwidth, which may correspond to a common channel where NPCA APs and NPCA non-AP STAs perform NPCA operations when it is determined that the BSS primary channel is busy due to OBSS frame exchange or OBSS PPDU.

[0169] In one embodiment, the NPCA minimum duration threshold field may indicate that when OBSS activity (or, inter-BSS activity) (e.g., OBSS (or, inter-BSS) PPDU or OBSS (or, inter-BSS) TXOP) is detected on the BSS primary channel, and the duration of said activity is longer than the value set in the NPCA minimum duration threshold field, an NPCA STA may switch to the NPCA primary channel to perform frame exchange. In one embodiment, an NPCA AP may set a minimum duration threshold at which it determines that the BSS primary channel is busy due to OBSS traffic, and if the duration of the OBSS activity does not reach this threshold, NPCA STAs may not switch to the NPCA primary channel. In one embodiment, NPCA STAs may not switch to the NPCA primary channel and may participate in EDCA competition on the BSS primary channel after an OBSS TXOP.

[0170] In one embodiment, the AP's switching delay field may indicate the time required for the AP to switch the operating channel from the BSS primary channel to the NPCA primary channel.

[0171] AP's switching back delay field may indicate the time required to switch the operating channel from the NPCA primary channel to the BSS primary channel.

[0172] In one embodiment, the NPCA AP may announce information regarding channel access delay in the NPCA primary channel by including it in the NPCA element, NPCA Operation Information field, or NPCA Operation Parameters field. The names of the fields or elements in which the channel access delay information may be included correspond to examples and are not limited thereto.

[0173] In one embodiment, the field containing the channel access delay information may have the same number of bits as the AP's switching delay field and AP's switching back delay field shown in FIG. 9. For example, if the channel access delay is indicated at intervals of 4 μs, each field may have 6 or 7 bits, and accordingly, the value related to the longest NPCA switching delay may be 256 μs.

[0174] In one embodiment, the NPCA AP may not use distinct subfields (e.g., channel access delay on NPCA primary channel field, NPCA Operation Information field, or NPCA Operation Parameters field) to provide information related to the channel access delay. For example, the NPCA AP may provide information related to the channel access delay by including it in the AP's switching delay field shown in FIG. 9 (c).

[0175] In one embodiment, the NPCA AP and all associated NPCA STAs participating in the NPCA may initiate transmission after the channel access delay in the NPCA primary channel has expired. Alternatively, all associated NPCA STAs participating in the NPCA may participate in EDCA competition after the channel access delay in the NPCA primary channel has expired.

[0176] In one embodiment, the starting point for waiting until the channel access delay expires may be the NPCA switch start time (i.e., the point at which the OBSS PPDU preamble is detected) of the NPCA switch from the BSS primary channel to the NPCA primary channel by the NPCA AP and / or NPCA STA. In one embodiment, the starting point for waiting for the channel access delay may be the time point at which the NPCA switch from the BSS primary channel to the NPCA primary channel is completed.

[0177] In one embodiment, a channel access delay may be used for admission control. For example, at least one NPCA STA having a switching delay shorter than the channel access delay set by the NPCA AP may wait from a starting point for waiting for the channel access delay until the NPCA channel access delay expires, and then participate in an EDCA competition or begin transmission. For example, at least one NPCA STA having a switching delay longer than the channel access delay set by the NPCA AP may not participate in an EDCA competition or begin transmission.

[0178] In one embodiment, the NPCA AP can set a channel access delay to determine and operate a mode for each NPCA STA during the NPCA execution described above. In one embodiment, the NPCA AP can determine the NPCA mode described above for each NPCA STA using the channel access delay. For example, at least one NPCA STA having a switching delay longer than the channel access delay set by the NPCA AP may not be able to perform an untriggered UL transmission (i.e., participate in EDCA contention). In this case, at least one NPCA STA having a switching delay longer than the channel access delay set by the NPCA AP may operate only in a mode based on a trigger from the NPCA AP.

[0179] The size (e.g., byte / bit size) and / or position of each of the fields included in the frame format or element formats illustrated in FIG. 9 above is merely an example for convenience of explanation, and the size and / or position of each of the fields may be implemented with various values ​​according to design specifications.

[0180] FIG. 10 is a flowchart illustrating the operation of a station according to one embodiment of the present disclosure.

[0181] In step 1000, the station can receive a first frame from the access point to which the station is associated.

[0182] In step 1010, the station can switch the operating channel from the basic service set (BSS) primary channel to the non-primary channel access (NPCA) primary channel.

[0183] In step 1020, the station can identify information related to the NPCA channel access delay included in the first frame.

[0184] In step 1030, the station may initiate uplink transmission after a time point based on the information regarding the NPCA channel access delay.

[0185] In one embodiment, if a station initiates uplink transmission after a time point based on the NPCA channel access delay information, it may participate in an enhanced distributed channel access (EDCA) competition on the NPCA primary channel after the time point based on the NPCA channel access delay information.

[0186] In one embodiment, when a station initiates uplink transmission after a time point based on information related to the NPCA channel access delay, if the switching delay of the station is longer than the NPCA channel access delay, the uplink transmission may be initiated by a trigger of the access point after the time of the switching delay of the station has elapsed.

[0187] In one embodiment, the NPCA channel access delay information may be related to information related to at least one station connected to the access point.

[0188] In one embodiment, the information related to the at least one station connected to the access point may include information related to the switching delay of the at least one station.

[0189] In one embodiment, the time point based on the NPCA channel access delay information may include the time point after the time indicated by the NPCA channel access delay information has elapsed since the station has completed switching to the NPCA primary channel or after it has been determined to switch to the NPCA primary channel.

[0190] In one embodiment, information related to the NPCA channel access delay may be included in either the channel access delay field included in the first frame or the switching delay field of the access point.

[0191] FIG. 11 is a flowchart illustrating the operation of an access point according to one embodiment of the present disclosure.

[0192] In step 1100, the access point can transmit a first frame to at least one connected station.

[0193] In step 1110, the access point can switch the operating channel from the BSS primary channel to the NPCA primary channel.

[0194] In one embodiment, the first frame may include information related to the NPCA channel access delay.

[0195] In one embodiment, the NPCA channel access delay information may instruct the at least one connected station to initiate uplink transmission after a time point based on the NPCA channel access delay information.

[0196] In one embodiment, a method characterized in that instructing to initiate uplink transmission after a time point based on the NPCA channel access delay information instructs to participate in an enhanced distributed channel access (EDCA) competition in the NPCA primary channel after the time point based on the NPCA channel access delay information.

[0197] In one embodiment, instructing to initiate uplink transmission after a time point based on the NPCA channel access delay information may instruct to initiate uplink transmission by a trigger of the access point after the time of the switching delay has elapsed, if the switching delay of a station connected to the access point is longer than the NPCA channel access delay.

[0198] In one embodiment, the NPCA channel access delay information may be related to information related to at least one station connected to the access point.

[0199] In one embodiment, the information related to the at least one station connected to the access point may include information related to the switching delay of the at least one station.

[0200] In one embodiment, the time point based on the NPCA channel access delay information may include the time point after the time indicated by the NPCA channel access delay information has elapsed since the time point after the at least one station has completed switching to the NPCA primary channel or after the time point in which it was decided to switch to the NPCA primary channel.

[0201] In one embodiment, information related to the NPCA channel access delay may be included in either the channel access delay field included in the first frame or the switching delay field of the access point.

[0202] FIG. 12 is a drawing showing an example of a configuration of a station according to one embodiment of the present disclosure.

[0203] In FIG. 12, the station may include at least one of a processor (1201), a transceiver (1202), and a memory (1203). At least one of the processor (1201), the transceiver (1202), and the memory (1203) of the station may operate according to the method(s) described in the embodiments described above in FIG. 1 to 11. However, the components of the station are not limited to the examples described above. For example, the station may include more components or fewer components than the components described above. In addition, the processor (1201), the transceiver (1202), and the memory (1203) may be implemented in the form of at least one chip.

[0204] The transceiver (1202) is a collective term for a receiver and a transmitter, and can transmit and receive signals with a station or other network entity through the transceiver (1202). At this time, the signal being transmitted and received may include at least one of control information and data. To this end, the transceiver (1202) may include an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that low-noise amplifies the received signal and down-converts the frequency. This is merely one embodiment of the transceiver (1202), and the components of the transceiver (1202) are not limited to an RF transmitter and an RF receiver. Additionally, the transceiver (1202) can receive a signal and output it to a processor (1201), and transmit the signal output from the processor (1201) to another network entity through a network.

[0205] The memory (1203) can store programs and data necessary for the operation of a station according to at least one of the embodiments of FIGS. 1 to 11. Additionally, the memory (03) can store control information and / or data included in signals obtained from the station. The memory (1203) may be composed of a storage medium or a combination of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD.

[0206] The processor (1201) can control a series of processes so that the station can operate according to at least one of the embodiments of FIGS. 1 to 11. The processor (1201) may include at least one processor.

[0207] FIG. 13 is a drawing showing an example of a configuration of an access point according to one embodiment of the present disclosure.

[0208] In FIG. 13, the access point may include at least one of a processor (1301), a transceiver (1302), and a memory (1303). At least one of the processor (1301), the transceiver (1302), and the memory (1303) of the access point may be operated according to the method(s) described in the embodiments described above in FIG. 1 to 11. However, the components of the access point are not limited to the examples described above. For example, the access point may include more components or fewer components than the components described above. In addition, the processor (1301), the transceiver (1302), and the memory (1303) may be implemented in the form of at least one chip.

[0209] The transceiver (1302) is a collective term for a receiver and a transmitter, and can transmit and receive signals with a station or other network entity through the transceiver (1302). At this time, the signal being transmitted and received may include at least one of control information and data. To this end, the transceiver (1302) may include an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that low-noise amplifies the received signal and down-converts the frequency. This is merely one embodiment of the transceiver (1302), and the components of the transceiver (1302) are not limited to an RF transmitter and an RF receiver. Additionally, the transceiver (1302) can receive a signal and output it to a processor (1301), and transmit the signal output from the processor (1301) to another network entity through a network.

[0210] The memory (1303) can store programs and data necessary for the operation of an access point according to at least one of the embodiments of FIGS. 1 to 11. Additionally, the memory (1303) can store control information and / or data included in a signal obtained from the access point. The memory (1303) may be composed of a storage medium or a combination of storage media such as ROM, RAM, a hard disk, a CD-ROM, and a DVD.

[0211] The processor (1301) can control a series of processes so that the access point can operate according to at least one of the embodiments of FIGS. 1 to 11. The processor (1301) may include at least one processor.

[0212] In the specific embodiments of the present disclosure described above, the components included in the present disclosure are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.

[0213] Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, it is understood that various modifications are possible within the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof.

Claims

1. In a method performed by a station in a wireless local area network (WLAN) communication system, A step of receiving a first frame from an access point associated with the above station; A step of switching the operating channel from a BSS (basic service set) primary channel to a NPCA (non-primary channel access) primary channel; A step of identifying information related to an NPCA channel access delay included in the first frame; and A method characterized by including the step of initiating uplink transmission after a time point based on the above NPCA channel access delay information.

2. In claim 1, the step of initiating uplink transmission after a time point based on the NPCA channel access delay information; is, A method characterized by including the step of participating in an EDCA (enhanced distributed channel access) competition in the NPCA primary channel after a time point based on the information regarding the NPCA channel access delay.

3. In paragraph 1, the step of initiating uplink transmission after a time point based on the NPCA channel access delay information; is, A method characterized by including the step of initiating uplink transmission by a trigger of the access point after the time of the switching delay of the station has elapsed, when the switching delay of the station is longer than the NPCA channel access delay.

4. In Paragraph 1, A method characterized in that the above NPCA channel access delay information is related to information related to at least one station connected to the access point.

5. A method according to claim 4, wherein the information related to at least one station connected to the access point includes information related to the switching delay of the at least one station.

6. In paragraph 1, the time point based on the NPCA channel access delay information is, A method characterized by including the fact that the time indicated by the NPCA channel access delay information has elapsed since the point in time when the station has completed switching to the NPCA primary channel or since the point in time when it was decided to switch to the NPCA primary channel.

7. A method according to claim 1, characterized in that the NPCA channel access delay information is included in either the channel access delay field included in the first frame or the switching delay field of the access point.

8. In a method performed by an access point in a wireless local area network (WLAN) communication system, A step of transmitting a first frame to at least one connected station; and The method includes the step of switching the operating channel from a BSS primary channel to a non-primary channel access (NPCA) primary channel; and The first frame above includes information related to NPCA channel access delay, and A method characterized by the above NPCA channel access delay information instructing the above at least one connected station to initiate uplink transmission after a time point based on the above NPCA channel access delay information.

9. In paragraph 8, instructing to initiate uplink transmission after a time point based on the information regarding the NPCA channel access delay is, A method characterized by instructing participation in an EDCA (enhanced distributed channel access) competition in the NPCA primary channel after a time point based on information regarding the NPCA channel access delay.

10. In paragraph 8, instructing to initiate uplink transmission after a time point based on the information regarding the NPCA channel access delay is, A method characterized by including, when the switching delay of a station connected to the access point is longer than the NPCA channel access delay, instructing the trigger of the access point to initiate uplink transmission after the time of the switching delay has elapsed.

11. In Paragraph 8, The above NPCA channel access delay information is related to information related to at least one station connected to the access point, and A method characterized in that the information related to at least one station connected to the access point includes information related to the switching delay of the at least one station.

12. In paragraph 8, the time point based on the information regarding the NPCA channel access delay is, A method characterized by including the fact that the time indicated by the NPCA channel access delay information has elapsed since the point in time when at least one station has completed switching to the NPCA primary channel or since the point in time when switching to the NPCA primary channel was determined.

13. A method according to claim 8, characterized in that the information related to the NPCA channel access delay is included in either the channel access delay field included in the first frame or the switching delay field of the access point.

14. In a station of a wireless local area network (WLAN) communication system, Transmitter / receiver; and One or more processors including processing circuitry; and It includes memory for storing instructions, and when the instructions are executed individually or collectively by one or more processors, the station: The above station receives a first frame from an associated access point, and Switch the operating channel from the BSS (basic service set) primary channel to the NPCA (non-primary channel access) primary channel, and Identifying NPCA channel access delay related information included in the first frame, and A station characterized by initiating uplink transmission after a time point based on the above-mentioned NPCA channel access delay information.

15. In an access point in a wireless local area network (WLAN) communication system, Transmitter / receiver; and One or more processors including processing circuitry; and It includes memory for storing instructions, and when the instructions are executed individually or collectively by the one or more processors, the access point: Transmit a first frame to at least one connected station, and It is configured to switch the operating channel from the BSS primary channel to the NPCA (non-primary channel access) primary channel, and The first frame above includes information related to NPCA channel access delay, and An access point characterized by the above NPCA channel access delay information instructing the above at least one connected station to initiate uplink transmission after a time point based on the above NPCA channel access delay information.

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