Method and apparatus for transmitting or receiving an extended control field in a wireless LAN system

Abstract

A method and apparatus for transmitting or receiving an extended control field in a wireless LAN system are disclosed. A method performed by a first station (STA) in a wireless LAN system according to an embodiment of the present disclosure includes receiving, from a second STA, a frame including a MAC (medium access control) header including one or more specific control fields, and based on the one or more specific control fields, performing processing on one or more fields included in a frame body within the frame. Based on the presence of an HT (high throughput) control field in the MAC header, the one or more specific control fields are further present in the HT control field. Based on the absence of the HT control field in the MAC header, the one or more specific control fields may be present at a specific position within the frame.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for transmitting or receiving an extended control field in a Wireless Local Area Network (WLAN) system.

Background Art

[0002] New technologies for improving the transmission rate, increasing the bandwidth, improving the reliability, reducing errors, and reducing latency have been introduced for Wireless Local Area Network (WLAN). Among the WLAN technologies, the standards of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series can be referred to as Wi-Fi. For example, technologies recently introduced to WLAN include enhancements for Very High-Throughput (VHT) of the 802.11ac standard, enhancements for High Efficiency (HE) of the IEEE 802.11ax standard, and the like.

[0003] In order to provide a more improved wireless communication environment, improvement technologies for Extremely High Throughput (EHT) are being discussed. For example, technologies for increased bandwidth, efficient utilization of multiple bands, Multiple Input Multiple Output (MIMO) to support increased spatial streams, and technologies for multi-access point (AP) coordination are being studied. In particular, various technologies for supporting traffic with low latency or real-time characteristics are being studied. In addition, new technologies for supporting ultra high reliability (UHR), including improvements or extensions of EHT technology, are being discussed.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technical problem of the present disclosure is to provide a method and apparatus for transmitting or receiving an extended control field in a wireless LAN system.

[0005] A further technical problem of the present disclosure is to provide a method and apparatus for transmitting or receiving a frame including a control field that supports an extended size within a media access control (MAC) header in a wireless LAN system.

[0006] The technical problem to be achieved in the present disclosure is not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present disclosure pertains from the following description.

Means for Solving the Problems

[0007] In a wireless LAN system according to an aspect of the present disclosure, a method performed by a first station (STA) includes receiving, from a second STA, a frame including a MAC (medium access control) header including one or more specific control fields, and performing processing on one or more fields included in a frame body within the frame based on the one or more specific control fields. Based on the presence of an HT (high throughput) control field in the MAC header, the one or more specific control fields further exist in the HT control field, and based on the absence of the HT control field in the MAC header, the one or more specific control fields may exist at a specific position within the frame.

[0008] In a wireless LAN system according to a further aspect of the present disclosure, a method performed by a second station (STA) includes generating a frame including a MAC (medium access control) header including one or more specific control fields and a frame body, and transmitting the generated frame to one or more first STAs. Based on the presence of an HT (high throughput) control field in the MAC header, the one or more specific control fields are further present in the HT control field. Based on the absence of the HT control field in the MAC header, the one or more specific control fields may be present at a specific position within the frame.

Advantages of the Invention

[0009] According to the present disclosure, it is possible to provide a method and apparatus for transmitting or receiving an extended control field in a wireless LAN system.

[0010] According to the present disclosure, it is possible to provide a method and apparatus for transmitting or receiving a frame including a control field that supports an extended size within a media access control (MAC) header in a wireless LAN system.

[0011] The effects obtained from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those of ordinary skill in the technical field to which the present disclosure pertains from the following description.

Brief Description of the Drawings

[0012] The accompanying drawings, which are included as a part of the detailed description to assist in understanding the present disclosure, provide embodiments of the present disclosure and explain the technical features of the present disclosure together with the detailed description.

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0014] Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed below together with the accompanying drawings is for explaining exemplary embodiments of the present disclosure, and is not for showing the only embodiments in which the present disclosure can be implemented. The following detailed description includes specific details in order to provide a complete understanding of the present disclosure. However, it is understood by those skilled in the art that the present disclosure can be implemented without such specific details.

[0015] In some cases, to avoid ambiguity in the concepts of the present disclosure, well-known structures and devices may be omitted and may be shown in the form of block diagrams centered on the core functions of each structure and device.

[0016] In the present disclosure, when a component is "connected", "coupled" or "connected" to another component, this may include not only a direct connection relationship but also an indirect connection relationship in which there are additional components between them. Also, in the present disclosure, the terms "comprising" or "having" identify the presence of the recited features, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components and / or groups thereof.

[0017] In the present disclosure, terms such as "first", "second", etc. are used only for the purpose of distinguishing one component from another and are not used to limit the components, and do not limit the order or importance, etc. between the components unless otherwise specified. Therefore, within the scope of the present disclosure, the first component in one embodiment can also be referred to as the second component in another embodiment, and similarly, the second component in one embodiment can be referred to as the first component in another embodiment.

[0018] The terms used in the present disclosure are for the purpose of describing specific embodiments and are not for limiting the scope of the claims. As used in the description of the embodiments and the appended claims, the singular form is intended to include the plural form as well, unless the context clearly dictates otherwise. The term "and / or" as used in the present disclosure may refer to one of the related listed items or may include any and all possible combinations of two or more of them. Also, in the present disclosure, the " / " between words has the same meaning as "and / or" unless otherwise specified.

[0019] The examples of the present disclosure may be applied to various wireless communication systems. For example, the examples of the present disclosure may be applied to a wireless LAN system. For example, the examples of the present disclosure may be applied to an IEEE 802.11a / g / n / ac / ax standard-based wireless LAN. Note that the examples of the present disclosure may be applied to a newly proposed IEEE 802.11bn (or, UHR) standard-based wireless LAN. Furthermore, the examples of the present disclosure may be applied to a next-generation standard-based wireless LAN after IEEE 802.11bn. Also, the examples of the present disclosure may be applied to a cellular wireless communication system. For example, it may be applied to a cellular wireless communication system based on the technologies of the LTE (Long Term Evolution) series and the 5G NR (New Radio) series of the 3GPP (registered trademark) (3rd Generation Partnership Project) standard.

[0020] Hereinafter, the technical features to which the examples of the present disclosure can be applied will be described.

[0021] FIG. 1 is a block configuration diagram illustrating a wireless communication device according to an embodiment of the present disclosure.

[0022] The first device 100 and the second device 200 illustrated in FIG. 1 may be referred to by various terms such as a terminal, a wireless device, a WTRU (Wireless Transmit Receive Unit), a UE (User Equipment), an MS (Mobile Station), a UT (user terminal), an MSS (Mobile Subscriber Station), an MSS (Mobile Subscriber Unit), an SS (Subscriber Station), an AMS (Advanced Mobile Station), a WT (Wireless terminal), or simply a user. Also, the first device 100 and the second device 200 may be referred to by various terms such as an access point (AP), a BS (Base Station), a fixed station, a Node B, a BTS (base transceiver system), a network, an AI (Artificial Intelligence) system, an RSU (road side unit), a repeater, a router, a relay, a gateway, etc.

[0023] The devices 100 and 200 illustrated in FIG. 1 can also be referred to as a station (STA). For example, the devices 100 and 200 illustrated in FIG. 1 can be referred to by various terms such as a transmitting device, a receiving device, a transmitting STA, a receiving STA, etc. For example, STA110 and 200 can play the role of an AP (access point) or a non-AP. That is, in the present disclosure, STA110 and 200 may have the functions of an AP and / or a non-AP. When STA110 and 200 have the AP function, it can also be simply called an AP, and when STA110 and 200 have the non-AP function, it can be simply called an STA. Also, in the present disclosure, an AP may be denoted as an AP STA.

[0024] Referring to FIG. 1, the first device 100 and the second device 200 can transmit and receive wireless signals using various wireless LAN technologies (e.g., IEEE 802.11 series). The first device 100 and the second device 200 may include interfaces for a medium access control (MAC) layer and a physical layer (PHY) that comply with the provisions of the IEEE 802.11 standard.

[0025] In addition, the first device 100 and the second device 200 can further support various communication standards other than wireless LAN technologies (e.g., 3GPP LTE series, 5G NR series standards, etc.). Also, the devices of the present disclosure may be embodied by various devices such as mobile phones, vehicles, personal computers, AR (Augmented Reality) equipment, VR (Virtual Reality) equipment, etc. Further, the STAs in this specification can support various communication services such as voice calls, video calls, data communication, autonomous driving, MTC (Machine-Type Communication), M2M (Machine-to-Machine), D2D (Device-to-Device), IoT (Internet-of-Things), etc.

[0026] The first device 100 includes one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 controls the memory 104 and / or the transceiver 106, and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts in the present disclosure. For example, after processing the information in the memory 104 to generate a first information / signal, the processor 102 can transmit a radio signal including the first information / signal via the transceiver 106. Also, after receiving a radio signal including a second information / signal via the transceiver 106, the processor 102 can store the information obtained from the signal processing of the second information / signal in the memory 104. The memory 104 may be connected to the processor 102 and can store various information related to the operation of the processor 102. For example, the memory 104 can store software code including instructions to execute part or all of the processes controlled by the processor 102 or to execute the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams in the present disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., the IEEE 802.11 series). The transceiver 106 may be connected to the processor 102 and can transmit and / or receive radio signals via one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used in the same sense as an RF (Radio Frequency) unit. In the present disclosure, the device can also mean a communication modem / circuit / chip.

[0027] The second device 200 includes one or more processors 202 and one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 controls the memory 204 and / or the transceiver 206, and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in the present disclosure. For example, after processing the information in the memory 204 to generate a third piece of information / signal, the processor 202 can transmit a radio signal including the third piece of information / signal via the transceiver 206. Also, after receiving a radio signal including a fourth piece of information / signal via the transceiver 206, the processor 202 can store the information obtained from the signal processing of the fourth piece of information / signal in the memory 204. The memory 204 may be connected to the processor 202 and can store various information related to the operation of the processor 202. For example, the memory 204 can store software code including instructions for executing part or all of the processes controlled by the processor 202 or for executing the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., the IEEE 802.11 series). The transceiver 206 may be connected to the processor 202 and can transmit and / or receive radio signals via one or more antennas 208. The transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used in the same sense as an RF unit. In the present disclosure, the device can also mean a communication modem / circuit / chip.

[0028] Hereinafter, the hardware elements of devices 100 and 200 will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors 102 and 202. For example, one or more processors 102 and 202 can implement one or more layers (e.g., functional layers such as PHY and MAC). One or more processors 102 and 202 can generate one or more PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) according to the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams in the present disclosure. One or more processors 102 and 202 can generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams in the present disclosure. One or more processors 102 and 202 can generate a signal (e.g., a baseband signal) including PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods in the present disclosure and provide it to one or more transceivers 106 and 206. One or more processors 102 and 202 can receive a signal (e.g., a baseband signal) from one or more transceivers 106 and 206 and obtain PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams in the present disclosure.

[0029] One or more processors 102, 202 can be referred to as a controller, microcontroller, microprocessor, or microcomputer. The one or more processors 102, 202 may be embodied by hardware, firmware, software, or a combination thereof. As an example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) may be included in the one or more processors 102, 202. The descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this disclosure may be embodied using firmware or software, and the firmware or software may be embodied to include modules, procedures, functions, and the like. The firmware or software configured to execute the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this disclosure may be included in the one or more processors 102, 202, stored in the one or more memories 104, 204, and driven by the one or more processors 102, 202. The descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this disclosure may be embodied by firmware or software in the form of code, instruction words, and / or a set of instruction words.

[0030] One or more memories 104, 204 may be coupled to one or more processors 102, 202 and can store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories 104, 204 may be constituted by a ROM, a RAM, an EPROM, a flash memory, a hard drive, a register, a cache memory, a computer-readable storage medium, and / or a combination thereof. The one or more memories 104, 204 may be located inside and / or outside the one or more processors 102, 202. Also, the one or more memories 104, 204 may be coupled to the one or more processors 102, 202 by various techniques such as wired or wireless connections.

[0031] One or more transceivers 106, 206 can transmit user data, control information, radio signals / channels, etc. mentioned in the methods and / or operation sequence diagrams of the present disclosure to one or more other devices. One or more transceivers 106, 206 can receive user data, control information, radio signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in the present disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and can transmit and receive radio signals. For example, one or more processors 102, 202 can control one or more transceivers 106, 206 to transmit user data, control information, or radio signals to one or more other devices. Also, one or more processors 102, 202 can control one or more transceivers 106, 206 to receive user data, control information, or radio signals from one or more other devices. Also, one or more transceivers 106, 206 may be connected to one or more antennas 108, 208, and one or more transceivers 106, 206 may be configured to transmit and receive user data, control information, radio signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in the present disclosure via one or more antennas 108, 208. In the present disclosure, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert received radio signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, radio signals / channels, etc. using one or more processors 102, 202. One or more transceivers 106, 206 may convert user data, control information, radio signals / channels, etc. processed using one or more processors 102, 202 from baseband signals to RF band signals. For this purpose, one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0032] For example, either one of STA100 and 200 can perform the intended operation of the AP, and the other one of STA100 and 200 can perform the intended operation of a non-AP STA. For example, the transceivers 106 and 206 in FIG. 1 can perform the transmission and reception operations of signals (e.g., packets or PPDUs (Physical layer Protocol Data Units) compliant with IEEE 802.11a / b / g / n / ac / ax / be / bn, etc.). Also, in the present disclosure, operations in which various STAs generate transmission and reception signals or perform data processing and calculations in advance for the transmission and reception signals may be performed by the processors 102 and 202 in FIG. 1. For example, an example of an operation of generating a transmission and reception signal or performing data processing and calculations in advance for the transmission and reception signal is 1) an operation of determining / acquiring / configuring / calculating / decoding / encoding bit information of fields (SIG (signal), STF (short training field), LTF (long training field), Data, etc.) included in the PPDU, 2) an operation of determining / configuring / acquiring time resources and frequency resources (e.g., subcarrier resources) used for fields (SIG, STF, LTF, Data, etc.) included in the PPDU, 3) an operation of determining / configuring / acquiring a specific sequence (e.g., pilot sequence, STF / LTF sequence, extra sequence applied to SIG) used for fields (SIG, STF, LTF, Data, etc.) included in the PPDU, 4) a power control operation and / or a power saving operation applied to the STA, 5) operations related to determining / acquiring / configuring / calculating / decoding / encoding of ACK signals may be included. Also, in the following example, various information (e.g., information related to fields / sub-fields / control fields / parameters / power, etc.) used by various STAs for determining / acquiring / configuring / calculating / decoding / encoding of transmission and reception signals may be stored in the memories 104 and 204 in FIG. 1.

[0033] Hereinafter, the downlink (DL) means a link for communication from an AP STA to a non-AP STA, and downlink PPDUs / packets / signals, etc. may be transmitted and received through the downlink. In downlink communication, the transmitter may be part of the AP STA and the receiver may be part of the non-AP STA. The uplink (UL) means a link for communication from a non-AP STA to an AP STA, and uplink PPDUs / packets / signals, etc. may be transmitted and received through the uplink. In uplink communication, the transmitter may be part of the non-AP STA and the receiver may be part of the AP STA.

[0034] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure is applicable.

[0035] The structure of the wireless LAN system may be composed of a plurality of components. A wireless LAN that supports STA mobility transparent to the upper layer may be provided by the interaction of the plurality of components. A BSS (Basic Service Set) corresponds to the basic building block of the wireless LAN. In FIG. 2, an example is shown in which two BSSs (BSS1 and BSS2) exist and two STAs are included as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). In FIG. 2, the ellipse representing the BSS may be understood to represent the coverage area in which the STAs included in the BSS maintain communication. This area can be referred to as a BSA (Basic Service Area). When an STA moves outside the BSA, it can no longer communicate directly with other STAs within the BSA.

[0036] If the DS shown in FIG. 2 is not considered, the most basic type of BSS in a wireless LAN is an Independent BSS (IBSS). For example, an IBSS can have the smallest form consisting of only two STAs. For example, assuming that other components are omitted, BSS1 consisting of only STA1 and STA2, or BSS2 consisting of only STA3 and STA4 can each correspond to a typical example of an IBSS. Such a configuration is possible when STAs can communicate directly without an AP. Also, such a form of wireless LAN is not pre-planned and configured, but can be configured when a LAN is needed, and this can also be referred to as an ad-hoc network. Since an IBSS does not include an AP, there is no centralized management entity that performs management functions centrally. That is, in an IBSS, STAs are managed in a distributed manner. In an IBSS, all STAs may be composed of mobile STAs, connection to a distributed system (DS) is not allowed, and it forms a self-contained network.

[0037] The membership of STAs in a BSS may be dynamically changed due to STAs joining or leaving, or STAs entering or leaving the BSS area. To become a member of a BSS, an STA can join the BSS using a synchronization process. To access all services of the BSS-based structure, an STA needs to be associated with the BSS. Such an association can be set dynamically and may include the use of a Distribution System Service (DSS).

[0038] In a wireless LAN, the direct STA-to-STA distance may be limited by PHY performance. In some cases, such distance limitations are sufficient, but in some cases, communication between STAs at a greater distance may be required. A distributed system (DS) may be configured to support extended coverage.

[0039] DS means a structure in which BSSs are interconnected. Specifically, as shown in FIG. 2, a BSS may exist as a component of an extended form of a network composed of a plurality of BSSs. DS is a logical concept and may be specified by the characteristics of the distributed system medium (DSM). In this regard, the wireless medium (Wireless Medium, WM) and DSM may be logically separated. Each logical medium is used for different purposes and is used by different components. These media are not limited to being the same or different. The flexibility of the wireless LAN structure (DS structure or other network structures) can be explained by the fact that a plurality of media are logically different from each other. That is, the wireless LAN structure may be implemented in various ways, and the wireless LAN structure may be specified independently according to the physical characteristics of each implementation example.

[0040] DS can support mobile devices by providing seamless integration of a plurality of BSSs and providing the logical services necessary for handling addresses to destinations. Further, DS may further include a component called a portal that acts as a bridge for connecting a wireless LAN and other networks (e.g., IEEE 802.X).

[0041] AP means an entity that enables access to the DS through the WM for associated non-AP STAs and also has the functionality of a STA. Data movement between the BSS and the DS can be performed via the AP. For example, STAs 2 and 3 shown in FIG. 2 provide the function of enabling associated non-AP STAs (STAs 1 and 4) to access the DS while having the functionality of a STA. Also, since all APs basically correspond to STAs, all APs are addressable entities. The address used by the AP for communication on the WM and the address used by the AP for communication on the DSM do not necessarily have to be the same. A BSS composed of an AP and one or more STAs can be referred to as an infrastructure BSS.

[0042] Data transmitted from one of the STAs associated with an AP to the STA address of the AP is always received at an uncontrolled port and may be processed by an IEEE 802.1X port access entity. Also, when the controlled port is authenticated, the transmitted data (or frame) can be transmitted to the DS.

[0043] An Extended Service Set (ESS) for providing a wider coverage may be set in the structure of the DS described above.

[0044] An ESS means a network composed of a DS and BSSs, where the network can have an arbitrary size and complexity. An ESS can correspond to a set of BSSs connected to one DS. However, an ESS does not include a DS. The ESS network is characterized in that it appears as an IBSS at the LLC (Logical Link Control) layer. STAs included in an ESS can communicate with each other, and a mobile STA can transparently move from one BSS to another (within the same ESS) to the LLC. APs included in one ESS may have the same SSID (service set identification). The SSID is distinguished from the BSSID, which is the identifier of a BSS.

[0045] In a wireless LAN system, without making any assumptions about the relative physical positions of BSSs, any of the following forms is possible. BSSs may partially overlap, which is a commonly used form to provide continuous coverage. Also, BSSs do not have to be physically connected, and there is no logical limit to the distance between BSSs. Also, BSSs may be physically located at the same position, which may be used to provide redundancy. Also, one (or one or more) IBSS or ESS networks may physically exist in the same space as one (or one or more) ESS networks. This can correspond to the ESS network form when an ad hoc network operates at the location where an ESS network exists, when wireless networks physically overlapping are configured by different organizations, or when two or more different access and security policies are required at the same location.

[0046] Figure 3 is a diagram for explaining a link setup process to which the present disclosure is applicable.

[0047] In order for a STA to set up a link with a network and transmit and receive data, it must first discover the network, perform authentication, establish an association, and carry out authentication procedures for security purposes. The link setup process can be referred to as the session start process and the session setup process. Also, the processes of discovery, authentication, association, and security settings in the link setup process can be collectively referred to as the association process.

[0048] In step S310, the STA can perform a network discovery operation. The network discovery operation may include the scanning operation of the STA. That is, in order for the STA to access the network, it must search for available networks. The STA must identify compatible networks before participating in the wireless network, and the process of identifying networks existing in a specific area is called scanning.

[0049] Scanning methods include active scanning and passive scanning. In FIG. 3, by way of example, a network discovery operation including an active scanning process is shown. In active scanning, the STA performing the scanning sends a probe request frame (probe request frame) to search for what APs exist in the vicinity while moving channels, and waits for a response thereto. The responder sends a probe response frame as a response to the probe request frame to the STA that sent the probe request frame. Here, the responder may be the STA that last sent a beacon frame in the BSS of the channel being scanned. Since the AP sends a beacon frame in the BSS, the AP becomes the responder, and in the IBSS, since the STAs within the IBSS send beacon frames alternately, the responder is not constant. For example, a STA that sends a probe request frame on channel 1 and receives a probe response frame on channel 1 saves the BSS-related information included in the received probe response frame, moves to the next channel (e.g., channel 2), and can perform scanning in the same way (i.e., send and receive probe requests / responses on channel 2).

[0050] Although not shown in FIG. 3, the scanning operation may be performed in a passive scanning method. In passive scanning, the STA that performs scanning waits for beacon frames while moving channels. A beacon frame is one of the management frames defined in IEEE 802.11, which notifies the existence of a wireless network and is periodically transmitted so that the STA performing scanning can search for a wireless network and participate in the wireless network. In a BSS, the AP plays the role of periodically transmitting beacon frames, and in an IBSS, the STAs within the IBSS transmit beacon frames alternately. When the STA performing scanning receives a beacon frame, it saves the information regarding the BSS included in the beacon frame and records the beacon frame information on each channel while moving to other channels. The STA that has received a beacon frame can save the BSS-related information included in the received beacon frame and move to the next channel to perform scanning on the next channel in the same way. Comparing active scanning and passive scanning, active scanning has the advantage that the delay and power consumption are smaller than those of passive scanning.

[0051] After the STA discovers the network, the authentication process may be performed in step S320. Such an authentication process can be called the first authentication process in order to clearly distinguish it from the security setup operation in step S340 described later.

[0052] The authentication process includes a process in which the STA transmits an authentication request frame (authentication request frame) to the AP and, in response, the AP transmits an authentication response frame to the STA. The authentication frame used for authentication request / response corresponds to a management frame.

[0053] The authentication frame may include information regarding the authentication algorithm number, authentication transaction sequence number, status code, challenge text, Robust Security Network (RSN), Finite Cyclic Group, etc. This corresponds to an example of some of the information that may be included in the authentication request / response frame, and may be replaced by other information or may further include additional information.

[0054] The STA can send an authentication request frame to the AP. The AP can determine whether to allow authentication for the STA based on the information included in the received authentication request frame. The AP can provide the result of the authentication process to the STA using an authentication response frame.

[0055] After the STA is successfully authenticated, the association process may be performed at stage S330. The association process includes the process in which the STA sends an association request frame to the AP and, in response, the AP sends an association response frame to the STA.

[0056] For example, the association request frame may include information regarding various capabilities, beacon listen interval, SSID (service set identifier), supported rates, supported channels, RSN, mobility domain, supported operating classes, TIM (Traffic Indication Map) broadcast request, information regarding interworking service capabilities, and the like. For example, the association response frame may include information regarding various capabilities, status code, AID (Association ID), supported rates, EDCA (Enhanced Distributed Channel Access) parameter set, RCPI (Received Channel Power Indicator), RSNI (Received Signal to Noise Indicator), mobility domain, timeout interval (e.g., association comeback time), overlapping BSS scan parameters, TIM broadcast response, QoS (Quality of Service) map, and the like. This corresponds to an example of some of the information that may be included in the association request / response frame, and may be replaced by other information or further additional information may be included.

[0057] After the STA is successfully associated with the network, the security setup process may be performed in step S340. The security setup process in step S340 can also be said to be an authentication process using RSNA (Robust Security Network Association) request / response. The authentication process in step S320 is referred to as the first authentication process, and the security setup process in step S340 can also be simply referred to as the authentication process.

[0058] The security setup process in step S340 may include, for example, a process of setting up a private key using a 4-way handshaking using EAPOL (Extensible Authentication Protocol over LAN) frames. Also, the security setup process may be performed by a security method not defined in the IEEE 802.11 standard.

[0059] FIG. 4 is a diagram for explaining a backoff process to which the present disclosure is applicable.

[0060] In a wireless LAN system, the basic access mechanism of MAC (Medium Access Control) is the CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) mechanism. The CSMA / CA mechanism, which is also called the Distributed Coordination Function (DCF) of IEEE 802.11 MAC, basically adopts the "listen before talk" access mechanism. According to such a type of access mechanism, before starting transmission, the AP and / or STA can perform CCA (Clear Channel Assessment) to sense the wireless channel or medium (e.g., DIFS (DCF Inter-Frame Space)) for a predetermined time interval. As a result of sensing, if it is determined that the medium is in an idle status, frame transmission can be started through the medium. On the other hand, if the medium is sensed as being in an occupied or busy state, the AP and / or STA do not start their own transmission and can set a delay period for medium access (e.g., a random backoff period) and wait, and then attempt frame transmission. By applying the random backoff period, it is expected that multiple STAs will attempt frame transmission after waiting for different times from each other, so collisions can be minimized.

[0061] In addition, the IEEE 802.11 MAC protocol provides HCF (Hybrid Coordination Function). HCF is based on the above-mentioned DCF and PCF (Point Coordination Function). PCF refers to a polling-based synchronous access method, in which all receiving APs and / or STAs periodically poll so that they can receive data frames. In addition, HCF has EDCA (Enhanced Distributed Channel Access) and HCCA (HCF Controlled Channel Access). EDCA is an access method in which the provider makes the access method for providing data frames to multiple users be competition-based, and HCCA is to use a non-competition-based channel access method using a polling mechanism. In addition, HCF includes a medium access mechanism for improving the QoS (Quality of Service) of a wireless LAN, and QoS data can be transmitted in both the Contention Period (CP) and the Contention Free Period (CFP).

[0062] With reference to FIG. 4, the operation based on the random backoff period will be described. When the medium that was in the occupied / busy state changes to the idle state, multiple STAs can attempt to transmit data (or frames). As a solution to minimize collisions, each STA can select a random backoff count and attempt transmission after waiting for the corresponding slot time. The random backoff count has a pseudo-random integer value and can be determined to be any one of the values in the range of 0 to CW. Here, CW is the contention window parameter value. The CW parameter is given an initial value of CWmin, but can take a value twice as large in the case of a transmission failure (for example, when an ACK for the transmitted frame cannot be received). When the CW parameter value reaches CWmax, data transmission can be attempted while maintaining the CWmax value until data transmission is successful, and when data transmission is successful, it is reset to the CWmin value. The CW, CWmin, and CWmax values are preferably set to 2 n -1 (n = 0, 1, 2,...).

[0063] When the random backoff process starts, the STA continues to monitor the medium while counting down the backoff slots by the determined backoff count value. When the medium is monitored as being in the occupied state, the countdown is stopped and waiting occurs, and when the medium becomes idle, the remaining countdown is resumed.

[0064] In the example of FIG. 4, when a packet to be transmitted arrives at the MAC of STA3, STA3 can confirm that the medium is idle for only DIFS and immediately transmit a frame. The remaining STAs monitor that the medium is in the occupied / busy state and wait. During this time, data to be transmitted may occur at each of STA1, STA2, and STA5. When each STA monitors that the medium is in the idle state, after waiting for only DIFS, it can count down the backoff slots according to the random backoff count value it has selected. Assume that STA2 selects the minimum backoff count value and STA1 selects the maximum backoff count value. That is, an example is illustrated in which when STA2 finishes the backoff count and starts frame transmission, the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1. STA1 and STA5 stop counting down for a while and wait while STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for only DIFS and then resume the stopped backoff count. That is, after counting down the remaining backoff slots for only the remaining backoff time, frame transmission can be started. Since the remaining backoff time of STA5 is shorter than that of STA1, STA5 starts frame transmission. Data to be transmitted may also occur at STA4 while STA2 occupies the medium. From the perspective of STA4, when the medium becomes idle, after waiting for only DIFS, it can count down according to the random backoff count value it has selected and start frame transmission. The example of FIG. 4 shows a case where the remaining backoff time of STA5 accidentally coincides with the random backoff count value of STA4. In this case, a collision may occur between STA4 and STA5. If a collision occurs, neither STA4 nor STA5 can receive an ACK and the data transmission will fail. In this case, STA4 and STA5 can select a random backoff count value after doubling the CW value and perform the countdown.STA1 waits while the medium is occupied due to the transmissions of STA4 and STA5. However, when the medium becomes idle, after waiting for only DIFS and when the remaining backoff time has elapsed, it can start transmitting a frame.

[0065] As shown in the example of FIG. 4, a data frame is a frame used for transmitting data to be forwarded to a higher layer, and may be transmitted after a backoff that occurs after the expiration of DIFS when the medium becomes idle. Further, a management frame is a frame used for exchanging management information that is not forwarded to a higher layer, and is transmitted after a backoff that occurs after the expiration of an IFS such as DIFS or PIFS (Point coordination function IFS). As subtypes of management frames, there are Beacon, Association request / response, Re-association request / response, Probe request / response, Authentication request / response, etc. A control frame is a frame used for controlling access to the medium. As subtypes of control frames, there are RTS (Request-To-Send), CTS (Clear-To-Send), ACK (Acknowledgment), PS-Poll (Power Save-Poll), BlockAck, BlockACKReq, NDP null data packet announcement, Trigger, etc. A control frame is transmitted after a backoff that occurs after the expiration of DIFS when it is not a response frame to a previous frame, and is transmitted without a backoff after the expiration of SIFS (short IFS) when it is a response frame to a previous frame. The type and subtype of a frame may be identified by the type field and subtype field within the frame control (FC) field.

[0066] A QoS (Quality of Service) STA can transmit a frame after a backoff that occurs after the expiration of AIFS (Arbitration IFS) for the access category (AC) to which the frame belongs, that is, AIFS[i] (where i is a value determined by the AC). Here, frames for which AIFS[i] can be used can be data frames, management frames, or control frames that are not response frames.

[0067] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure is applicable.

[0068] As described above, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing in which a STA directly senses the medium. Virtual carrier sensing is for complementing problems that can occur in medium access, such as the hidden node problem. For virtual carrier sensing, the MAC of a STA can use the NAV (Network Allocation Vector). The NAV is a value that indicates to other STAs the time remaining until the medium becomes available for a STA that is currently using the medium or has the right to use it. Therefore, the value set as the NAV corresponds to the period during which the use of the medium is scheduled by the STA that transmits the frame, and the STA that receives the NAV value is prohibited from accessing the medium during that period. For example, the NAV may be set based on the value of the "duration" field in the MAC header of the frame.

[0069] In the example of FIG. 5, assume that STA1 is about to transmit data to STA2, and STA3 is in a position where it can overhear part or all of the frames transmitted and received between STA1 and STA2.

[0070] In the CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames may be applied to reduce the possibility of transmission collisions among multiple STAs. In the example of FIG. 5, while the transmission of STA1 is in progress, as a result of the carrier sensing of STA3, it may be determined that the medium is in an idle state. That is, STA1 may be a hidden node to STA3. Or, in the example of FIG. 5, while the transmission of STA2 is in progress, as a result of the carrier sensing of STA3, it may be determined that the medium is in an idle state. That is, STA2 may be a hidden node to STA3. Before performing data transmission and reception between STA1 and STA2, by exchanging RTS / CTS frames, STAs outside the transmission range of either STA1 or STA2, or STAs outside the carrier sensing range for the transmission from STA1 or STA3, can be prevented from attempting to occupy the channel during the data transmission and reception between STA1 and STA2.

[0071] Specifically, STA1 can use carrier sensing to determine whether the channel is in use. In terms of physical carrier sensing, STA1 can determine the channel occupancy idle state based on the magnitude of the energy detected from the channel or the signal correlation. Also, in terms of virtual carrier sensing, STA1 can use the NAV (network allocation vector) timer to determine the occupancy state of the channel.

[0072] When the channel is in an idle state at DIFS, STA1 can transmit an RTS frame to STA2 after performing backoff. When STA2 receives the RTS frame, it can transmit a CTS frame, which is a response to the RTS frame, to STA1 after SIFS.

[0073] Although STA3 cannot overhear the CTS frame from STA2, if it can overhear the RTS frame from STA1, STA3 can use the duration information included in the RTS frame to set the NAV timer for the subsequent consecutive frame transmission period (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame). Or, although STA3 cannot overhear the RTS frame from STA1, if it can overhear the CTS frame from STA2, STA3 can use the duration information included in the CTS frame to set the NAV timer for the subsequent consecutive frame transmission period (e.g., SIFS + data frame + SIFS + ACK frame). That is, when STA3 can overhear one or more of the RTS or CTS frames from at least one of STA1 or STA2, it can set the NAV based on this. When STA3 receives a new frame before the NAV timer expires, it can update the NAV timer using the duration information included in the new frame. STA3 does not attempt channel access until the NAV timer expires.

[0074] When STA1 receives a CTS frame from STA2, it can transmit a data frame to STA2 after SIFS from the time when the reception of the CTS frame is completed. When STA2 successfully receives the data frame, it can transmit an ACK frame, which is a response to the data frame, to STA1 after SIFS. When the NAV timer of STA3 expires, it can use carrier sensing to determine whether the channel is in use. When STA3 determines that the channel is not used by other terminals during the period from the expiration of the NAV timer to DIFS, it can attempt channel access after the contention window (CW) by random backoff has passed.

[0075] FIG. 6 is a diagram for explaining an example of a frame structure used in a wireless LAN system to which the present disclosure is applicable.

[0076] By an instruction or primitive (meaning a set of an instruction or parameters) from the MAC layer, the PHY layer can prepare an MPDU (MAC PDU) to be transmitted. For example, when receiving an instruction requesting the start of transmission from the MAC layer, the PHY layer switches to the transmission mode and can configure and transmit information (e.g., data) provided from the MAC layer in the form of a frame. Also, in the PHY layer, when detecting a valid preamble of the received frame, the PHY layer monitors the preamble header and sends an instruction notifying the start of reception in the PHY layer to the MAC layer.

[0077] In this way, information transmission / reception in a wireless LAN system is performed in the form of a frame, and for this purpose, a Physical layer Protocol Data Unit (PPDU) frame format is defined.

[0078] A basic PPDU may include a STF (Short Training Field), an LTF (Long Training Field), a SIG (SIGNAL) field, and a Data field. The most basic (e.g., non-HT (High Throughput) shown in FIG. 7) PPDU format may be composed of only an L-STF (Legacy-STF), an L-LTF (Legacy-LTF), an L-SIG (Legacy-SIG) field, and a Data field. Also, depending on the type of PPDU format (e.g., HT-mixed format PPDU, HT-greenfield format PPDU, VHT (Very High Throughput) PPDU, etc.), additional (or other types of) RL-SIG, U-SIG, non-legacy SIG fields, non-legacy STF, non-legacy LTF (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) may be included between the L-SIG field and the Data field. For more specific matters, refer to FIG. 7 and it will be described later.

[0079] The STF is a signal for signal detection, AGC (Automatic Gain Control), diversity selection, precise time synchronization, etc., and the LTF is a signal for channel estimation, frequency error estimation, etc. It can be said that the STF and the LTF are signals for synchronization and channel estimation of the OFDM physical layer.

[0080] The SIG field may contain various information related to PPDU transmission and reception. For example, the L-SIG field is composed of 24 bits, and the L-SIG field may include a 4-bit Rate field, a 1-bit Reserved bit, a 12-bit Length field, a 1-bit Parity field, and a 6-bit Tail field. The RATE field may contain information regarding the modulation and coding rate of the data. For example, the 12-bit Length field may contain information regarding the length or time duration of the PPDU. For example, the value of the 12-bit Length field may be determined based on the type of the PPDU. For example, for non-HT, HT, VHT, or EHT PPDUs, the value of the Length field may be determined to be a multiple of 3. For example, for HE PPDUs, the value of the Length field may be determined to be a multiple of 3 + 1 or a multiple of 3 + 2.

[0081] The data field may include a SERVICE field, a PSDU (Physical layer Service Data Unit), PPDU TAIL bits, and, if necessary, padding bits. Some bits of the SERVICE field may be used for the synchronization of the descrambler at the receiving end. The PSDU corresponds to the MAC PDU defined at the MAC layer and may include data generated / used at the upper layer. The PPDU TAIL bits may be used to return the encoder to the 0 state. The padding bits may be used to align the length of the data field to a predetermined unit.

[0082] The MAC PDU is defined by various MAC frame formats, and the basic MAC frame is composed of a MAC header, a frame body, and an FCS (Frame Check Sequence). The MAC frame is composed of MAC PDUs and may be transmitted / received by the PSDU in the data part of the PPDU format.

[0083] The MAC header includes a Frame Control field, a Duration / ID field, an Address field, etc. The Frame Control field may include control information necessary for frame transmission / reception. The Duration / ID field may be set to the time for transmitting the frame, etc. The address sub-field can indicate the receiver address, transmitter address, destination address, and source address of the frame, and some address sub-fields may be omitted. It includes Sequence Control, QoS Control, and HT Control sub-fields. For the specific content of each sub-field of the MAC header, reference can be made to the IEEE 802.11 standard document.

[0084] The Null Data PPDU (NDP) format means a PPDU format that does not include a data field. That is, NDP means a frame format that includes PPDU preambles (i.e., L-STF, L-LTF, L-SIG fields, and, if present, further non-legacy SIG, non-legacy STF, non-legacy LTF) in the general PPDU format and does not include the remaining part (i.e., the data field).

[0085] FIG. 7 is a diagram showing an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure is applicable.

[0086] In standards such as IEEE 802.11a / g / n / ac / ax, various forms of PPDUs are used. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and Data fields. The basic PPDU format can also be referred to as the non-HT PPDU format (FIG. 7(a)).

[0087] The HT PPDU format (IEEE 802.11n) further includes the HT-SIG, HT-STF, and HT-LFT(s) fields in the basic PPDU format. The HT PPDU format shown in Figure 7(b) can be referred to as the HT-mixed format. An HT-greenfield format PPDU may be further defined, which corresponds to a format composed of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a Data field without including L-STF, L-LTF, and L-SIG (not shown).

[0088] An example of the VHT PPDU format (IEEE 802.11ac) further includes the VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in the basic PPDU format (Figure 7(c)).

[0089] An example of the HE PPDU format (IEEE 802.11ax) further includes the RL-SIG (Repeated L-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and PE (Packet Extension) fields in the basic PPDU format (Figure 7(d)). Depending on the detailed illustration of the HE PPDU format, some fields may be excluded or their lengths may change. For example, the HE-SIG-B field is included in the HE PPDU format for multiple users (MU) and not included in the HE PPDU format for a single user (SU). Also, the HE trigger-based (TB) PPDU format does not include the HE-SIG-B, and the length of the HE-STF field may change to 8 us. The HE ER (Extended Range) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may change to 16 us. For example, RL-SIG may be configured identically to L-SIG. The receiving STA can determine that the received PPDU is an HE PPDU or an EHT PPDU described later based on the presence of RL-SIG.

[0090] The EHT PPDU format may include the EHT MU (multi-user) of FIG. 7(e) and the EHT TB (trigger-based) PPDU of FIG. 7(f). The EHT PPDU format is similar to the HE PPDU format in that it includes an RL-SIG following the L-SIG, but may include a U (universal)-SIG, an EHT-SIG, an EHT-STF, and an EHT-LTF following the RL-SIG.

[0091] The EHT MU PPDU of FIG. 7(e) corresponds to a PPDU that carries one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU may be used for either SU transmission or MU transmission. For example, the EHT MU PPDU may correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0092] The EHT TB PPDU of FIG. 7(f) omits the EHT-SIG compared to the EHT MU PPDU. A STA that has received a trigger for UL MU transmission (e.g., a trigger frame or TRS (triggered response scheduling)) can perform UL transmission based on the EHT TB PPDU format.

[0093] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields may be encoded and modulated so that they can also be demodulated and decoded in a legacy STA, and may be mapped based on a defined subcarrier frequency interval (e.g., 312.5 kHz). These may be referred to as pre-EHT modulated fields. Next, the EHT-STF, EHT-LTF, Data, and PE fields may be encoded and modulated so that they can be demodulated and decoded by an STA that has successfully decoded a non-legacy SIG (e.g., U-SIG and / or EHT-SIG) and obtained the information contained in the field, and may be mapped based on a defined subcarrier frequency interval (e.g., 78.125 kHz). These may be referred to as EHT modulated fields.

[0094] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields may be referred to as pre-HE modulated fields, and the HE-STF, HE-LTF, Data, and PE fields may be referred to as HE modulated fields. Also, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields may be referred to as pre-VHT modulated fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and Data fields may be referred to as VHT modulated fields.

[0095] The U-SIG included in the EHT PPDU format of FIG. 7 may be configured based on, for example, 2 symbols (e.g., 2 consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG may have a duration of 4 us, and the U-SIG may have an overall duration of 8 us. Each symbol of the U-SIG may be used to transmit 26 bits of information. For example, each symbol of the U-SIG may be transmitted and received based on 52 data tones and 4 pilot tones.

[0096] The U-SIG may be configured in units of 20 MHz. For example, when an 80 MHz PPDU is configured, the same U-SIG may be replicated in units of 20 MHz. That is, the same four U-SIGs may be included in the 80 MHz PPDU. When the bandwidth exceeds 80 MHz, for example, for a 160 MHz PPDU, the U-SIG of the first 80 MHz unit and the U-SIG of the second 80 MHz unit may be different from each other.

[0097] In the U-SIG, for example, A uncoded bits may be transmitted. The first symbol of the U-SIG (for example, the U-SIG-1 symbol) may transmit the first X bits of the total A-bit information, and the second symbol of the U-SIG (for example, the U-SIG-2 symbol) may transmit the remaining Y bits of the total A-bit information. The A-bit information (for example, 52 uncoded bits) may include a CRC field (for example, a 4-bit long field) and a tail field (for example, a 6-bit long field). The tail field may be used to terminate the trellis of the convolutional decoder and may be set to 0, for example.

[0098] The A-bit information transmitted by the U-SIG can be distinguished into version-independent bits and version-dependent bits. For example, the U-SIG may be included in a new PPDU format (for example, the UHR PPDU format) not shown in FIG. 7. In the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format, the version-independent bits may be the same, and some or all of the version-dependent bits may be different.

[0099] For example, the size of the version-independent bits of U-SIG may be fixed or variable. The version-independent bits may be assigned only to U-SIG-1 symbols, or may be assigned to both U-SIG-1 symbols and U-SIG-2 symbols. The version-independent bits and the version-dependent bits may be referred to by various names such as the first control bit and the second control bit.

[0100] For example, the version-independent bits of U-SIG may include a 3-bit physical layer version identifier, and this information can indicate the PHY version (such as EHT, UHR, etc.) of the transmitted and received PPDU. The version-independent bits of U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field is related to UL communication, and the second value of the UL / DL flag field is related to DL communication. The version-independent bits of U-SIG may include information regarding the length of the TXOP (transmission opportunity) and information regarding the BSS color ID.

[0101] For example, the version-dependent bits of U-SIG may include information that directly or indirectly indicates the type of the PPDU (such as SU PPDU, MU PPDU, TB PPDU, etc.).

[0102] The information necessary for the transmission and reception of the PPDU may be included in U-SIG. For example, U-SIG may further include information regarding the bandwidth, information regarding the MCS method applied to the non-legacy SIG (such as EHT-SIG or UHR-SIG, etc.), information indicating whether a DCM (dual carrier modulation) method (such as reusing the same signal on two subcarriers) is applied to achieve an effect similar to frequency diversity for the non-legacy SIG, information regarding the number of symbols used for the non-legacy SIG, information regarding whether the non-legacy SIG is generated over the entire bandwidth, etc.

[0103] Some of the information necessary for PPDU transmission and reception may be included in the U-SIG and / or non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information regarding the type of non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information regarding the length of the non-legacy LTF and the CP (cyclic prefix) length, information regarding the GI (guard interval) applied to the non-legacy LTF, information regarding preamble puncturing applicable to the PPDU, information regarding RU (resource unit) allocation, etc. may be included only in the U-SIG, may be included only in the non-legacy SIG, or may be indicated by a combination of the information included in the U-SIG and the information included in the non-legacy SIG.

[0104] Preamble puncturing can mean the transmission of a PPDU where there is no signal present in one or more frequency units in the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble puncturing) may be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing may be applied to a PPDU bandwidth of a predetermined size or more.

[0105] In the example of FIG. 7, non-legacy SIGs such as HE-SIG-B and EHT-SIG may include control information for the receiving STA. The non-legacy SIG may be transmitted in at least one symbol, and one symbol may have a length of 4 us. Information regarding the number of symbols used for the EHT-SIG may be included in a previous SIG (e.g., HE-SIG-A, U-SIG, etc.).

[0106] Non-legacy SIGs such as HE-SIG-B and EHT-SIG may include a common field and user-specific fields. The common field and user-specific fields may be coded separately.

[0107] In some cases, the common field may be omitted. For example, the common field may be omitted in a compression mode where non-OFDMA (orthogonal frequency multiple access) is applied, and multiple STAs can receive a PPDU (e.g., the data field of the PPDU) in the same frequency band. In a non-compression mode where OFDMA is applied, multiple users can receive a PPDU (e.g., the data field of the PPDU) in individual frequency bands.

[0108] The number of user-specific fields may be determined based on the number of users. One user block field may include at most two user fields. Each user field may be related to MU-MIMO allocation or non-MU-MIMO allocation.

[0109] The common field may include CRC bits and Tail bits. The length of the CRC bits may be determined to be 4 bits, and the length of the Tail bits may be determined to be 6 bits and may be set to 000000. The common field may include RU allocation information. The RU allocation information may include information regarding the location of the RUs allocated to multiple users (i.e., multiple receiving STAs).

[0110] An RU may include a plurality of subcarriers (or tones). An RU may be used when transmitting signals to a plurality of STAs based on the OFDMA technique. Also, an RU may be defined when transmitting a signal to one STA. Resources may be allocated in units of RUs for non-legacy STF, non-legacy LTF, and Data fields.

[0111] The size of the RU applicable according to the PPDU bandwidth may be defined. The RU may be defined to be the same or different for the applicable PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80 MHz PPDU, the RU arrangements of the HE PPDU and the EHT PPDU may be different from each other. The size of the RU applicable according to the PPDU bandwidth, the number of RUs, the RU position, the DC (direct current) subcarrier position and number, the null subcarrier position and number, the guard subcarrier position and number, etc. can be referred to as a tone-plan. For example, the tone-plan for a wide bandwidth may be defined in the form of multiple repetitions of the tone-plan for a low bandwidth.

[0112] RUs of various sizes may be defined such as 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, 484-tone RU, 996-tone RU, 2×996-tone RU, 4×996-tone RU, etc. An MRU (multiple RU) is distinguished from a plurality of individual RUs and corresponds to a group of subcarriers composed of a plurality of RUs. For example, one MRU may be defined as 52 + 26 tones, 106 + 26 tones, 484 + 242 tones, 996 + 484 tones, 996 + 484 + 242 tones, 2×996 + 484 tones, 3×996 tones, or 3×996 + 484 tones. Also, the plurality of RUs constituting one MRU may or may not be continuous in the frequency domain.

[0113] The specific size of the RU may be reduced or expanded. Therefore, in the present disclosure, the specific size of each RU (i.e., the number of corresponding tones) is exemplary rather than restrictive. Also, in the present disclosure, within a predetermined bandwidth (e.g., 20, 40, 80, 160, 320 MHz,...), the number of RUs may vary depending on the size of the RU.

[0114] In the PPDU format of FIG. 7, the names of the respective fields are exemplary, and the scope of the present disclosure is not limited by the names. Also, the examples of the present disclosure may be applied not only to the PPDU format illustrated in FIG. 7, but also to a new PPDU format in which some fields are excluded and / or some fields are added based on the PPDU format of FIG. 7.

[0115] HT Control Field

[0116] FIG. 8 is a diagram showing an exemplary format of an aggregated-control (A-control) subfield of an HT control field to which the present disclosure is applicable.

[0117] As described with reference to FIG. 6, the HT control field may be included in the MAC header. The HT control field is present in a control wrapper frame and may be present in QoS Data, QoS Null, and management frames as determined by the +HTC subfield of the frame control field.

[0118] The HT control field may have a format as shown in Table 1.

[0119]

Table 1

[0120] As shown in Table 1, the HE variant HT control field may include an A (aggregated)-control subfield. The A-control subfield may have a length of 30 bits.

[0121] As shown in FIG. 8, the A-control subfield may include a variable-length control list subfield and a padding subfield of 0 bits or more. The control list subfield may include one or more control subfields. The padding subfield (if present) may follow the last control subfield and may be set as a sequence of 0 values that makes the length of the A-control subfield included in the HT control field equal to 30.

[0122] One control subfield may include a 4-bit control ID subfield and a variable-length control information subfield.

[0123] The control ID subfield can indicate the type of information included in the control information subfield. The length of the control information subfield may be defined as a fixed value for each value of the control ID subfield (excluding reserved values). The value of the control ID subfield and the length of the associated control information subfield may be defined as shown in Table 2.

[0124]

Table 2

[0125] Table 2 indicates the lengths of the formats of control subfields (TRS, OM, HLA, BSR, UPH, BQR, CAS, EHT OM, SRS, AAR, etc.) indicated by control ID values. The ONES control subfield may have all 26 bits set to 1. The formats of each of the other control subfields are defined separately, among which an exemplary format of the HLA (HE link adaptation) control subfield having a length of 12 bits is shown in FIG. 8.

[0126] The control information subfield of the HLA control subfield may include information related to the HE link adaptation (HLA) procedure.

[0127] The unsolicited MFB (MCS (modulation and coding scheme) feedback) subfield may correspond to an unsolicited MFB indicator. The MRQ subfield may correspond to an HLA feedback request indicator. The NSS subfield may correspond to the recommended number of spatial streams. The HE-MCS subfield may correspond to the recommended HE-MCS. The DCM subfield may correspond to the recommended usage of DCM (dual carrier modulation). The RU allocation subfield may correspond to the RU of the recommended HE-MCS or to the RU specified by the MFB requester (requester) for which feedback is received. The BW subfield may correspond to the bandwidth of the recommended HE-MCS or to the bandwidth specified by the MFB requester for which feedback is received. The MSI (MRQ sequence identifier) / partial PPDU parameter subfield may correspond to the partial parameters of the measured PPDU or to the MRQ sequence identifier. The Tx beamforming subfield may correspond to the transmission type of the measured PPDU (i.e., the presence or absence of beamforming application). The UL HE TB PPDU MFB subfield may correspond to an indication for MFB for the HE TB PPDU transmitted in the uplink.

[0128] Extended Control Field

[0129] As described above, for the HT control field in the case of the HE variant format, only 26 bits out of the 30 bits of the A-control subfield, excluding the 4-bit control list subfield, may contain control information. That is, there is a constraint that the existing HT control field can provide a container for up to 26 bits of control information. In an improved wireless LAN system, more control information may be required to be included in the MAC frame (i.e., the MAC header and / or the frame body) in order to support a wider bandwidth, more RU allocations, more spatial stream numbers, a higher MCS, etc.

[0130] For example, as the Control ID values included in the A-control subfield, 8 are defined in the 802.11ax-based wireless LAN system (i.e., 0 to 6, and 15), and 3 more are defined in 802.11be (i.e., 7 to 9), and the reserved Control ID values are 5 (i.e., 10 to 14). Also, the maximum size of the content of the A-Control subfield is 26 bits, and in the case of the HLA control subfield, 25 bits out of the 26-bit information size are defined, and only 1 bit is defined as the reserved bit. For link adaptation in an improved wireless LAN system, it may be necessary to expand the size for the bandwidth (BW), RU allocation, NSS subfield, etc. in the HLA control subfield, but there may be cases where such additional information cannot be included in the HT control field with only the reserved 1-bit size. Therefore, an extension of the HT control field that can contain information of a size exceeding the existing 26-bit limit (e.g., a modification of the HT control field or the definition of a new control field) is required.

[0131] In this disclosure, various examples for the extension of the HT control field will be described. In the following description, the HE variant HT control field including the A-control subfield will be described as a representative example. However, the scope of this disclosure is not limited by its name, and the following examples may also be applicable to other variants or control fields in other formats.

[0132] Hereinafter, in order to distinguish from the existing HT control field, the extended example of the HT control field according to this disclosure will be referred to by the non-limiting name of non-legacy control field. The name non-legacy may mean that it is applicable to the next wireless LAN system, and may also be various names such as EHT+ or UHR that are distinguished from the name EHT of 802.11be.

[0133] FIG. 9 is a diagram for explaining an example of a method of transmitting a frame including a non-legacy control field according to this disclosure.

[0134] In step S910, the first STA can receive a frame including a non-legacy control field from the second STA.

[0135] Here, the non-legacy control field may correspond to one or more specific control fields that are distinguished from the existing HT control field. For example, when there is an HT control field in the MAC header, the non-legacy control field may further exist in the MAC header in addition to the HT control field. Or, when there is no HT control field in the MAC header, the non-legacy control field may exist at a specific position within the frame. For example, the non-legacy control field may exist at the last field position of the MAC header, the position followed by the frame body, or the position following the HT control field.

[0136] The non-legacy control field may be included instead of the HT control field. The non-legacy control field may be defined to have the same size as the HT control field. In this case, the +HTC subfield within the frame control field of the MAC header may indicate the presence or absence of the non-legacy control field rather than the presence or absence of the HT control field (in this case, it may have a different name from the +HTC subfield).

[0137] The non-legacy control field may be included in the frame body instead of being included in the MAC header. Including it in the frame body may correspond to defining a new type or subtype of MAC frame format that includes the non-legacy control field.

[0138] The non-legacy control field may be included in the MAC header but defined as a field having a size larger than that of the HT control field (e.g., more than 4 octets (e.g., 5 octets or 6 octets)). Such a non-legacy control field may be further included in the HT control field or included in a frame that does not include the HT control field.

[0139] For example, the +HTC subfield within the frame control field of the MAC header (or a subfield with a new name corresponding to the existing +HTC subfield position) may also indicate the presence or absence of the non-legacy control field. In this case, the +HTC subfield (or a subfield with a new name corresponding to the existing +HTC subfield position) does not indicate the presence or absence of the HT control field, and the HT control field may be defined as not existing within the MAC frame. That is, it is not necessary to indicate the presence or absence of the HT control field.

[0140] For example, the first bit of the frame body may indicate the presence or absence of the non-legacy control field.

[0141] For example, the formats applied to the MAC header may include a first format and a second format. The first format corresponds to a format that does not include information indicating the presence or absence of a non-legacy control field, and the second format may correspond to a new format that includes information (e.g., 1-bit information) indicating the presence or absence of a non-legacy control field. The MAC header of the second format may have a larger size (e.g., a size including information indicating the presence or absence of a non-legacy control field, or a size including information indicating the presence or absence of a non-legacy control field and the non-legacy control field) than the MAC header of the first format. Alternatively, the protocol version subfield within the frame control field of the MAC header may have various values (e.g., a value of 4), and one of the values may indicate that the second format is applied. The presence or absence of the HT control field is indicated by the +HTC subfield within the frame control field of the MAC header, and the information indicating the presence or absence of the non-legacy control field may be included in a field (e.g., an additional 1 bit of the MAC header of the second format) distinct from the +HTC subfield.

[0142] For example, a specific value (e.g., any one of the values 10 to 14 reserved in advance) of the control ID subfield within the A-control subfield of the HT control field can also indicate the presence of a non-legacy control field. The A-control subfield including the control ID subfield with such a specific value may (or may not) include a control information subfield with a length set to 0. Alternatively, the control information subfield within the A-control subfield including the control ID subfield with such a specific value may include information regarding the number and / or use of non-legacy control fields.

[0143] In step S920, the first STA can perform processing on the frame body based on the non-legacy control field.

[0144] For example, a non-legacy control field (e.g., one or more specific control fields) within a frame may contain information related to link adaptation in a wireless LAN system that supports an extended bandwidth. Based on this, processing such as decoding / analysis / calculation for one or more fields included in the frame body within the same frame can be performed.

[0145] That is, the processing for the frame body at the first STA that receives the frame may include procedures such as decoding / analysis / calculation for the frame body. For example, the PHY entity of the first STA may receive a PPDU via the wireless medium and perform processing such as calculation / measurement based on the fields included in the PPDU (e.g., TXTIME calculation, pilot-based channel state extrapolation, etc.), decoding / descrambling for the fields included in the PPDU (e.g., performing decoding / descrambling based on the indication information of the SIG field for the DATA field of the PPDU to obtain the PSDU). The result derived from the processing for the PPDU, for example, the PSDU, may be transmitted as an MPDU / A (aggregated)-MPDU from the PHY entity to the MAC entity. The MPDU / A-MPDU may include one or more MAC frames. The processing for the MAC frame may perform parsing, defragmentation, etc. for the fields included in the MAC frame to obtain the information included in the MAC frame. For example, the information included in the MAC header of the MAC frame can be analyzed and obtained, and based on this, the information included in the frame body of the MAC frame can be analyzed and obtained.

[0146] The method described in the illustration of FIG. 9 may be performed by the first device 100 of FIG. 1. For example, one or more processors 102 of the first device 100 of FIG. 1 may receive a frame including a non-legacy control field from another device via one or more transceivers 106, and based on the information, process the information included in the frame body of the frame. Note that one or more memories 104 of the first device 100 may store instructions for performing the method described in the illustration of FIG. 9 or the illustration described later when executed by one or more processors 102.

[0147] FIG. 10 is a diagram for explaining an example of a method of receiving a frame including a non-legacy control field according to the present disclosure.

[0148] In step S1010, the second STA may generate a frame including a non-legacy control field.

[0149] Here, the non-legacy control field may correspond to one or more specific control fields, and the description related to the frame including the non-legacy field is the same as the illustration of FIG. 9, and the overlapping description is omitted.

[0150] In step S1020, the second STA may transmit the generated frame to one or more other STAs.

[0151] The method described in the illustration of FIG. 10 may be performed by the second device 200 of FIG. 1. For example, one or more processors 202 of the second device 200 of FIG. 1 may generate a frame including a frame including a non-legacy control field and information in the frame body configured based on this, and transmit it to other devices via one or more transceivers 206. Note that one or more memories 204 of the second device 200 may store instructions for performing the method described in the illustration of FIG. 10 or the illustration described later when executed by one or more processors 202.

[0152] The illustrations in FIGS. 9 and 10 may correspond to some of the various illustrations of the present disclosure. Hereinafter, various illustrations of the present disclosure including the illustrations in FIGS. 9 and 10 will be described in more detail.

[0153] In the embodiments described below, the format of a frame including an extended control field (or, non-legacy control field) will be mainly described, and link adaptation related information will be described as a representative example of the control information included in the extended control field. However, the scope of the present disclosure is not limited by the type or characteristics of the information included in the extended control field. That is, the illustrations described below are characterized in defining the format of a frame including a control field in a new format that can provide a container for control information with an extended size compared to the existing ones, and any control information may be included in the extended control field according to the present disclosure.

[0154] FIG. 11 is a diagram for explaining an example of a frame format including an extended control field according to the present disclosure.

[0155] Example 1

[0156] Referring to FIG. 11(a), the non-legacy control field may be included in the frame alternatively to the existing HT control field.

[0157] For example, a STA compliant with a wireless LAN system that supports a non-legacy control field can analyze the field existing at the HT control field position in the existing MAC header as a non-legacy control field. A STA compliant with an existing wireless LAN system can analyze the HT control field in the MAC header in the same way as the existing one. That is, according to the version of the supporting wireless LAN system (for example, a wireless LAN system before EHT, or a wireless LAN system subsequent to EHT), a field of the same size at the same position can be analyzed as an HT control field or a non-legacy control field. Therefore, this field can be referred to as, for example, an "HT / non-legacy control field".

[0158] Whether the HT / non-legacy control field exists in the MAC header may be indicated by the value of the +HTC subfield within the frame control subfield in the existing MAC header.

[0159] According to this embodiment, for a STA that complies with a wireless LAN system that supports a non-legacy control field, a MAC header format including the existing HT control field may not be supported. The non-legacy control field may be defined to include information of the existing HT control field, or the subtype or subvariant of the non-legacy control field may be defined to correspond to various types and / or various variants of the existing HT control field.

[0160] Example 2

[0161] Referring to FIG. 11(b), the non-legacy control field may be newly defined as a field that is distinguishable from the existing HT control field. For example, unlike the existing HT control field being defined as 4 octets (or bytes) in size, the non-legacy control field may be defined as having a size greater than 4 octets (e.g., 5 octets or 6 octets).

[0162] Whether the existing HT control field exists in the MAC header may be indicated by the existing +HTC subfield. This disclosure includes various examples indicating whether the non-legacy control field exists in the MAC header.

[0163] Example 2-1

[0164] The existing +HTC subfield can be newly defined to indicate the presence or absence of a non-legacy control field instead of the existing HT control field. In this case, the +HTC subfield may have another name, but the presence or absence of the non-legacy control field may be indicated by a new-named field having the same position and size as the existing +HTC subfield within the frame control field of the MAC header. That is, the value of the subfield at the same position can be parsed as the value of the +HTC subfield in the same way as the existing for a STA following an existing wireless LAN system that does not support the non-legacy control field, and can be parsed as the value of the subfield indicating the presence or absence of the non-legacy control field for a STA following a new wireless LAN system that supports the non-legacy control field.

[0165] In this case, similar to Example 1, for a STA following a wireless LAN system that supports the non-legacy control field, a MAC header format including the existing HT control field may not be supported. That is, in the illustration of FIG. 11(b), in the new wireless LAN system, the size / length of the HT control field may be defined to always be 0 (however, the non-legacy control field may be defined to include the information of the existing HT control field / corresponding information). That is, similarly, the presence or absence of the non-legacy control field may be indicated by the +HTC subfield (or, a subfield with a new name), except that the size of the non-legacy control field is different in Example 1 and Example 2-1.

[0166] Example 2-2

[0167] Information indicating the presence or absence of the non-legacy control field can be defined within the MAC header. The information indicating the presence or absence of the non-legacy control field may be defined as, for example, 1-bit information.

[0168] In the currently defined MAC header format (e.g., the first format), since there are no reserved bits, a wireless LAN system that supports a non-legacy control field can define and support a new MAC header format (e.g., the second format) that includes information indicating the presence or absence of the non-legacy control field.

[0169] For example, some fields / sub-fields of the existing MAC header (e.g., fields / sub-fields corresponding to information not used in the new wireless LAN system) can also be reused as information indicating the presence or absence of the non-legacy control field. In this case, the size of the MAC header excluding the non-legacy control field may be the same in the first and second formats.

[0170] For example, it may be included as a bit where information indicating the presence or absence of the non-legacy control field is added to the MAC header. In this case, the size of the MAC header excluding the non-legacy control field may be larger in the second format than in the first format. For example, the size of the information indicating the presence or absence of the non-legacy control field is 1 bit, but the second format is defined to be 1 octet larger than the first format, and 1 bit of the additional 1 octet may be defined as the information indicating the presence or absence of the non-legacy control field. If the MAC header further includes an X-octet non-legacy control field, the second format may be defined to be X + 1 octets larger than the first format. Or, the second format may be defined to further include an additional field of 1 or X octet size compared to the first format, and a part of 1 octet of the additional field corresponds to the information indicating the presence or absence of the non-legacy control field. If the non-legacy control field does not exist, the additional field has a size of 1 octet, and if the non-legacy control field exists, X octets are defined as the size including the information indicating the presence or absence of the non-legacy control field and the non-legacy control field.

[0171] When defining a new format for the MAC header in this way, it is also possible to indicate that it is the new format by the value of the protocol version subfield within the frame control field of the MAC header. For example, the existing protocol version subfield is defined as 2 bits in size and can indicate 4 values. Among them, the first value and the second value can indicate the existing defined content, and the MAC header of the new format according to the present disclosure may be indicated by the third value or the fourth value.

[0172] As an addition or alternative, a part of the frame body (for example, the first bit) can be defined and used as information indicating the presence or absence of a non-legacy control field.

[0173] Example 2-3

[0174] It may be defined that a specific control ID value (for example, any one of the values from 10 to 14 in Table 2) of the A-control subfield of the HT control field corresponds to the non-legacy control field indication. The HT control field including the A-control subfield set to the specific control ID value can indicate that a non-legacy control field is included at a specific position within the frame. For example, the position of the non-legacy control field may correspond to the last field position of the MAC frame, the position following the HT control field, or the position followed by the frame body.

[0175] In the A-control subfield set to the control ID value corresponding to the non-legacy control field indication, the control information subfield may be set to a length of 0 (or defined as non-existent). That is, the HT control field including the A-control field corresponding to the non-legacy control field indication may be defined to have a minimum overhead.

[0176] Alternatively, in the A-control subfield set to a control ID value corresponding to a non-legacy control field instruction, the control information subfield may include non-legacy control field related information. The non-legacy control field related information may include the number of non-legacy control fields (or subfields), the use of the non-legacy control field, etc. The use of the non-legacy control field may be defined to include various uses such as trigger response scheduling related information, operation mode information, link adaptation related information, etc., similar to the control ID in A-control, for example.

[0177] Example 3

[0178] Referring to FIG. 11(c), a new type or new subtype of frame including non-legacy control information may be defined. In the above-described Examples 1 and 2, it corresponds to an example of the structure in which information indicating the presence or absence of the non-legacy control field is included in the frame to support the frame including the non-legacy control field, while Example 3 may include non-legacy control information in the frame body regardless of the MAC header (i.e., applicable to any newly defined format of MAC header as well as the existing defined MAC header).

[0179] For example, a new control type and / or control subtype of frame including non-legacy control information may be defined. That is, the non-legacy control information may be included in a new independent control / management / data frame. This can be distinguished from the case where a non-legacy control field is included in the MAC header of the existing management / data frame in Example 1 or 2.

[0180] For example, in an existing wireless LAN system, the value 10 of the control type and the value 0001 of the subtype reserved therein can be defined as corresponding to a non-legacy control frame. The HT control field of the MAC header of such a non-legacy control frame may contain control information (identical to the existing one) according to the control ID of A-control. In this case, the non-legacy control information contained in the frame body of the non-legacy control frame may contain control information unrelated to or separate from the HT control information. Or, the non-legacy control information contained in the frame body of the non-legacy control frame may contain additional information associated with the information contained in the A-control subfield of the HT control field (for example, not contained in the fields defined in the existing A-control subfield but required in the new wireless LAN system). For example, requests or response information for link adaptation such as HLA control may be contained in the HT control field within the MAC header of the non-legacy control frame and / or the non-legacy control information of the frame body. Also, one or more control IDs and the corresponding control information may be contained in the HT control field within the MAC header of the non-legacy control frame and / or the non-legacy control information of the frame body.

[0181] When defining and supporting non-legacy control frames, within an A (aggregated)-MPDU, frames containing non-legacy control information may be transmitted or received together with other control / management / data frames.

[0182] In an existing wireless LAN system, the HT control field in the MAC header may not be suitable for transmitting and receiving control information required in a new wireless LAN system related to UHR, etc., due to its limited size. Therefore, in the present disclosure, a new / extended non-legacy control field that is distinguishable from the existing HT control field is defined, and by various schemes in which the non-legacy control field is included in the MAC frame in addition to or instead of the existing HT control field, a new effect of providing an extended container capable of transmitting or receiving control information required in a new wireless LAN system can be achieved.

[0183] The embodiments described above are those in which the components and features of the present disclosure are combined in a predetermined form. Each component or feature should be considered as optional unless otherwise explicitly mentioned. Each component or feature may be implemented in a form that does not combine with other components or features. Also, it is possible to configure embodiments of the present disclosure by combining some components and / or features. The order of operations described in the embodiments of the present disclosure may be changed. Some configurations or features of one embodiment may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is obvious that embodiments can be configured by combining claims that do not have an explicit citation relationship in the claims, or can be included as new claims by amendment after filing.

[0184] It is obvious to those skilled in the art that the present disclosure can be embodied in other specific forms without departing from the essential features of the present disclosure. Therefore, the above detailed description should not be construed as restrictive in any way and should be considered as exemplary. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and any changes within the equivalent scope of the present disclosure are included in the scope of the present disclosure.

[0185] The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that cause an apparatus or computer to perform operations according to the methods of various embodiments, and non-transitory computer-readable media on which such software or instructions are stored and executable on the apparatus or computer. Instructions that can be used to program a processing system to perform the features described in the present disclosure may be stored on / within a storage medium or computer-readable storage medium, and the features described in the present disclosure may be implemented using a computer program product including such a storage medium. The storage medium can include, but is not limited to, high-speed random access memory such as DRAM, SRAM, DDR RAM, or other random access solid-state memory devices, and can include non-volatile memory such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory can optionally include one or more storage devices located remotely from the processor. The memory or, alternatively, the non-volatile memory device within the memory includes a non-transitory computer-readable storage medium. The features described in the present disclosure can be stored on any one of the machine-readable media, control the hardware of the processing system, and be integrated into software and / or firmware that enables the processing system to interact with other mechanisms to utilize the results according to the embodiments of the present disclosure. Such software or firmware can include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

Industrial Applicability

[0186] Although the method proposed in the present disclosure has been mainly described with an example applied to an IEEE 802.11-based system, it can be applied to various wireless LANs or wireless communication systems other than the IEEE 802.11-based system.

Claims

1. A method performed by a first station (STA) in a wireless LAN system, the method comprising: receiving, from a second STA, a frame including a MAC (medium access control) header including one or more specific control fields; processing one or more fields included in a frame body within the frame based on the one or more specific control fields; wherein the one or more specific control fields further exist in the HT control field based on the presence of an HT (high throughput) control field in the MAC header; wherein the one or more specific control fields exist at a specific position within the frame based on the absence of the HT control field in the MAC header.

2. The specific position is corresponding to the last field of the MAC header, a position followed by the frame body, or a position following the HT control field, according to the method of Claim 1.

3. The +HTC subfield within the frame control field of the MAC header indicates the presence or absence of the one or more specific control fields, according to the method of Claim 1.

4. The +HTC subfield does not indicate the presence or absence of the HT control field, wherein the HT control field is defined as not existing in the frame, according to the method of Claim 3.

5. The first bit of the frame body indicates the presence or absence of the one or more specific control fields, according to the method of Claim 1.

6. The format applied to the MAC header includes a first format and a second format, wherein the second format further includes information indicating the presence or absence of the one or more specific control fields compared to the first format, according to the method of Claim 1.

7. The MAC header of the second format has a larger size compared to the MAC header of the first format, according to the method of Claim 6.

8. One value of the protocol version subfield within the frame control field of the MAC header indicates that the second format is applied, according to the method of Claim 6.

9. The presence or absence of the HT control field is indicated by the +HTC subfield within the frame control field of the MAC header, The method according to claim 6, wherein the information indicating the presence or absence of the one or more specific control fields is included in a field that is distinguished from the +HTC subfield. **Claim 10** The method according to claim 1, wherein a specific value of a control identifier subfield within a combined control (A-control) subfield of the HT control field indicates the presence of the one or more specific control fields. **Claim 11** The method according to claim 10, wherein for the A-control subfield including the control identifier subfield of the specific value, the length of a control information subfield within the A-control subfield is 0. **Claim 12** The control information subfield within the A-control subfield including the control identifier subfield of the specific value, the number of the one or more specific control fields, or the use of the one or more specific control fields The method according to claim 10, including information regarding one or more of them. **Claim 13** The method according to claim 1, wherein the one or more specific control fields have a size exceeding 4 octets. **Claim 14** A first station (STA) device in a wireless LAN system, the device comprising: one or more transceivers, and one or more processors coupled to the one or more transceivers, wherein the one or more processors are configured to: receive, from a second STA via the one or more transceivers, a frame including a MAC (medium access control) header including one or more specific control fields, perform processing on one or more fields included in a frame body within the frame based on the one or more specific control fields, wherein based on the presence of an HT (high throughput) control field in the MAC header, the one or more specific control fields further exist in the HT control field, and based on the absence of the HT control field in the MAC header, the one or more specific control fields exist at a specific position within the frame. **Claim 15** A method performed by a second station (STA) in a wireless LAN system, the method comprising: generating a frame including a MAC (medium access control) header including one or more specific control fields and a frame body; transmitting the generated frame to one or more first STAs; based on the presence of an HT (high throughput) control field in the MAC header, the one or more specific control fields further exist in the HT control field; based on the absence of the HT control field in the MAC header, the one or more specific control fields exist at specific positions within the frame. **Claim 16** A second station (STA) device in a wireless LAN system, the device comprising: one or more transceivers; one or more processors coupled to the one or more transceivers; wherein the one or more processors: generate a frame including a MAC (medium access control) header including one or more specific control fields and a frame body; are configured to transmit the generated frame to one or more first STAs via the one or more transceivers; based on the presence of an HT (high throughput) control field in the MAC header, the one or more specific control fields further exist in the HT control field; based on the absence of the HT control field in the MAC header, the one or more specific control fields exist at specific positions within the frame. **Claim 17** A processing device configured to control a station (STA) in a wireless LAN system, the processing device comprising: one or more processors; one or more computer memories operably coupled to the one or more processors and storing instructions for performing the method according to any one of claims 1 to 13 based on execution by the one or more processors. **Claim 18** One or more non-transitory computer-readable media storing one or more instructions, The one or more instructions are executed by one or more processors and control a device in a wireless LAN system to perform the method according to any one of claims 1 to 13, a computer-readable medium.

Images